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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* faulty.c : Multiple Devices driver for Linux
*
* Copyright (C) 2004 Neil Brown
*
* fautly-device-simulator personality for md
*/
/*
* The "faulty" personality causes some requests to fail.
*
* Possible failure modes are:
* reads fail "randomly" but succeed on retry
* writes fail "randomly" but succeed on retry
* reads for some address fail and then persist until a write
* reads for some address fail and then persist irrespective of write
* writes for some address fail and persist
* all writes fail
*
* Different modes can be active at a time, but only
* one can be set at array creation. Others can be added later.
* A mode can be one-shot or recurrent with the recurrence being
* once in every N requests.
* The bottom 5 bits of the "layout" indicate the mode. The
* remainder indicate a period, or 0 for one-shot.
*
* There is an implementation limit on the number of concurrently
* persisting-faulty blocks. When a new fault is requested that would
* exceed the limit, it is ignored.
* All current faults can be clear using a layout of "0".
*
* Requests are always sent to the device. If they are to fail,
* we clone the bio and insert a new b_end_io into the chain.
*/
#define WriteTransient 0
#define ReadTransient 1
#define WritePersistent 2
#define ReadPersistent 3
#define WriteAll 4 /* doesn't go to device */
#define ReadFixable 5
#define Modes 6
#define ClearErrors 31
#define ClearFaults 30
#define AllPersist 100 /* internal use only */
#define NoPersist 101
#define ModeMask 0x1f
#define ModeShift 5
#define MaxFault 50
#include <linux/blkdev.h>
#include <linux/module.h>
#include <linux/raid/md_u.h>
#include <linux/slab.h>
#include "md.h"
#include <linux/seq_file.h>
static void faulty_fail(struct bio *bio)
{
struct bio *b = bio->bi_private;
b->bi_iter.bi_size = bio->bi_iter.bi_size;
b->bi_iter.bi_sector = bio->bi_iter.bi_sector;
bio_put(bio);
bio_io_error(b);
}
struct faulty_conf {
int period[Modes];
atomic_t counters[Modes];
sector_t faults[MaxFault];
int modes[MaxFault];
int nfaults;
struct md_rdev *rdev;
};
static int check_mode(struct faulty_conf *conf, int mode)
{
if (conf->period[mode] == 0 &&
atomic_read(&conf->counters[mode]) <= 0)
return 0; /* no failure, no decrement */
if (atomic_dec_and_test(&conf->counters[mode])) {
if (conf->period[mode])
atomic_set(&conf->counters[mode], conf->period[mode]);
return 1;
}
return 0;
}
static int check_sector(struct faulty_conf *conf, sector_t start, sector_t end, int dir)
{
/* If we find a ReadFixable sector, we fix it ... */
int i;
for (i=0; i<conf->nfaults; i++)
if (conf->faults[i] >= start &&
conf->faults[i] < end) {
/* found it ... */
switch (conf->modes[i] * 2 + dir) {
case WritePersistent*2+WRITE: return 1;
case ReadPersistent*2+READ: return 1;
case ReadFixable*2+READ: return 1;
case ReadFixable*2+WRITE:
conf->modes[i] = NoPersist;
return 0;
case AllPersist*2+READ:
case AllPersist*2+WRITE: return 1;
default:
return 0;
}
}
return 0;
}
static void add_sector(struct faulty_conf *conf, sector_t start, int mode)
{
int i;
int n = conf->nfaults;
for (i=0; i<conf->nfaults; i++)
if (conf->faults[i] == start) {
switch(mode) {
case NoPersist: conf->modes[i] = mode; return;
case WritePersistent:
if (conf->modes[i] == ReadPersistent ||
conf->modes[i] == ReadFixable)
conf->modes[i] = AllPersist;
else
conf->modes[i] = WritePersistent;
return;
case ReadPersistent:
if (conf->modes[i] == WritePersistent)
conf->modes[i] = AllPersist;
else
conf->modes[i] = ReadPersistent;
return;
case ReadFixable:
if (conf->modes[i] == WritePersistent ||
conf->modes[i] == ReadPersistent)
conf->modes[i] = AllPersist;
else
conf->modes[i] = ReadFixable;
return;
}
} else if (conf->modes[i] == NoPersist)
n = i;
if (n >= MaxFault)
return;
conf->faults[n] = start;
conf->modes[n] = mode;
if (conf->nfaults == n)
conf->nfaults = n+1;
}
static bool faulty_make_request(struct mddev *mddev, struct bio *bio)
{
struct faulty_conf *conf = mddev->private;
int failit = 0;
if (bio_data_dir(bio) == WRITE) {
/* write request */
if (atomic_read(&conf->counters[WriteAll])) {
/* special case - don't decrement, don't submit_bio_noacct,
* just fail immediately
*/
bio_io_error(bio);
return true;
}
if (check_sector(conf, bio->bi_iter.bi_sector,
bio_end_sector(bio), WRITE))
failit = 1;
if (check_mode(conf, WritePersistent)) {
add_sector(conf, bio->bi_iter.bi_sector,
WritePersistent);
failit = 1;
}
if (check_mode(conf, WriteTransient))
failit = 1;
} else {
/* read request */
if (check_sector(conf, bio->bi_iter.bi_sector,
bio_end_sector(bio), READ))
failit = 1;
if (check_mode(conf, ReadTransient))
failit = 1;
if (check_mode(conf, ReadPersistent)) {
add_sector(conf, bio->bi_iter.bi_sector,
ReadPersistent);
failit = 1;
}
if (check_mode(conf, ReadFixable)) {
add_sector(conf, bio->bi_iter.bi_sector,
ReadFixable);
failit = 1;
}
}
md_account_bio(mddev, &bio);
if (failit) {
struct bio *b = bio_alloc_clone(conf->rdev->bdev, bio, GFP_NOIO,
&mddev->bio_set);
b->bi_private = bio;
b->bi_end_io = faulty_fail;
bio = b;
} else
bio_set_dev(bio, conf->rdev->bdev);
submit_bio_noacct(bio);
return true;
}
static void faulty_status(struct seq_file *seq, struct mddev *mddev)
{
struct faulty_conf *conf = mddev->private;
int n;
if ((n=atomic_read(&conf->counters[WriteTransient])) != 0)
seq_printf(seq, " WriteTransient=%d(%d)",
n, conf->period[WriteTransient]);
if ((n=atomic_read(&conf->counters[ReadTransient])) != 0)
seq_printf(seq, " ReadTransient=%d(%d)",
n, conf->period[ReadTransient]);
if ((n=atomic_read(&conf->counters[WritePersistent])) != 0)
seq_printf(seq, " WritePersistent=%d(%d)",
n, conf->period[WritePersistent]);
if ((n=atomic_read(&conf->counters[ReadPersistent])) != 0)
seq_printf(seq, " ReadPersistent=%d(%d)",
n, conf->period[ReadPersistent]);
if ((n=atomic_read(&conf->counters[ReadFixable])) != 0)
seq_printf(seq, " ReadFixable=%d(%d)",
n, conf->period[ReadFixable]);
if ((n=atomic_read(&conf->counters[WriteAll])) != 0)
seq_printf(seq, " WriteAll");
seq_printf(seq, " nfaults=%d", conf->nfaults);
}
static int faulty_reshape(struct mddev *mddev)
{
int mode = mddev->new_layout & ModeMask;
int count = mddev->new_layout >> ModeShift;
struct faulty_conf *conf = mddev->private;
if (mddev->new_layout < 0)
return 0;
/* new layout */
if (mode == ClearFaults)
conf->nfaults = 0;
else if (mode == ClearErrors) {
int i;
for (i=0 ; i < Modes ; i++) {
conf->period[i] = 0;
atomic_set(&conf->counters[i], 0);
}
} else if (mode < Modes) {
conf->period[mode] = count;
if (!count) count++;
atomic_set(&conf->counters[mode], count);
} else
return -EINVAL;
mddev->new_layout = -1;
mddev->layout = -1; /* makes sure further changes come through */
return 0;
}
static sector_t faulty_size(struct mddev *mddev, sector_t sectors, int raid_disks)
{
WARN_ONCE(raid_disks,
"%s does not support generic reshape\n", __func__);
if (sectors == 0)
return mddev->dev_sectors;
return sectors;
}
static int faulty_run(struct mddev *mddev)
{
struct md_rdev *rdev;
int i;
struct faulty_conf *conf;
if (md_check_no_bitmap(mddev))
return -EINVAL;
conf = kmalloc(sizeof(*conf), GFP_KERNEL);
if (!conf)
return -ENOMEM;
for (i=0; i<Modes; i++) {
atomic_set(&conf->counters[i], 0);
conf->period[i] = 0;
}
conf->nfaults = 0;
rdev_for_each(rdev, mddev) {
conf->rdev = rdev;
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
}
md_set_array_sectors(mddev, faulty_size(mddev, 0, 0));
mddev->private = conf;
faulty_reshape(mddev);
return 0;
}
static void faulty_free(struct mddev *mddev, void *priv)
{
struct faulty_conf *conf = priv;
kfree(conf);
}
static struct md_personality faulty_personality =
{
.name = "faulty",
.level = LEVEL_FAULTY,
.owner = THIS_MODULE,
.make_request = faulty_make_request,
.run = faulty_run,
.free = faulty_free,
.status = faulty_status,
.check_reshape = faulty_reshape,
.size = faulty_size,
};
static int __init raid_init(void)
{
return register_md_personality(&faulty_personality);
}
static void raid_exit(void)
{
unregister_md_personality(&faulty_personality);
}
module_init(raid_init);
module_exit(raid_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Fault injection personality for MD (deprecated)");
MODULE_ALIAS("md-personality-10"); /* faulty */
MODULE_ALIAS("md-faulty");
MODULE_ALIAS("md-level--5");
| linux-master | drivers/md/md-faulty.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2001 Sistina Software (UK) Limited
*
* This file is released under the GPL.
*/
#include "dm-core.h"
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <linux/bio.h>
#include <linux/dax.h>
#define DM_MSG_PREFIX "target"
static LIST_HEAD(_targets);
static DECLARE_RWSEM(_lock);
static inline struct target_type *__find_target_type(const char *name)
{
struct target_type *tt;
list_for_each_entry(tt, &_targets, list)
if (!strcmp(name, tt->name))
return tt;
return NULL;
}
static struct target_type *get_target_type(const char *name)
{
struct target_type *tt;
down_read(&_lock);
tt = __find_target_type(name);
if (tt && !try_module_get(tt->module))
tt = NULL;
up_read(&_lock);
return tt;
}
static void load_module(const char *name)
{
request_module("dm-%s", name);
}
struct target_type *dm_get_target_type(const char *name)
{
struct target_type *tt = get_target_type(name);
if (!tt) {
load_module(name);
tt = get_target_type(name);
}
return tt;
}
void dm_put_target_type(struct target_type *tt)
{
down_read(&_lock);
module_put(tt->module);
up_read(&_lock);
}
int dm_target_iterate(void (*iter_func)(struct target_type *tt,
void *param), void *param)
{
struct target_type *tt;
down_read(&_lock);
list_for_each_entry(tt, &_targets, list)
iter_func(tt, param);
up_read(&_lock);
return 0;
}
int dm_register_target(struct target_type *tt)
{
int rv = 0;
down_write(&_lock);
if (__find_target_type(tt->name)) {
DMERR("%s: '%s' target already registered",
__func__, tt->name);
rv = -EEXIST;
} else {
list_add(&tt->list, &_targets);
}
up_write(&_lock);
return rv;
}
EXPORT_SYMBOL(dm_register_target);
void dm_unregister_target(struct target_type *tt)
{
down_write(&_lock);
if (!__find_target_type(tt->name)) {
DMCRIT("Unregistering unrecognised target: %s", tt->name);
BUG();
}
list_del(&tt->list);
up_write(&_lock);
}
EXPORT_SYMBOL(dm_unregister_target);
/*
* io-err: always fails an io, useful for bringing
* up LVs that have holes in them.
*/
static int io_err_ctr(struct dm_target *tt, unsigned int argc, char **args)
{
/*
* Return error for discards instead of -EOPNOTSUPP
*/
tt->num_discard_bios = 1;
tt->discards_supported = true;
return 0;
}
static void io_err_dtr(struct dm_target *tt)
{
/* empty */
}
static int io_err_map(struct dm_target *tt, struct bio *bio)
{
return DM_MAPIO_KILL;
}
static int io_err_clone_and_map_rq(struct dm_target *ti, struct request *rq,
union map_info *map_context,
struct request **clone)
{
return DM_MAPIO_KILL;
}
static void io_err_release_clone_rq(struct request *clone,
union map_info *map_context)
{
}
static void io_err_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
limits->max_discard_sectors = UINT_MAX;
limits->max_hw_discard_sectors = UINT_MAX;
limits->discard_granularity = 512;
}
static long io_err_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
long nr_pages, enum dax_access_mode mode, void **kaddr,
pfn_t *pfn)
{
return -EIO;
}
static struct target_type error_target = {
.name = "error",
.version = {1, 6, 0},
.features = DM_TARGET_WILDCARD,
.ctr = io_err_ctr,
.dtr = io_err_dtr,
.map = io_err_map,
.clone_and_map_rq = io_err_clone_and_map_rq,
.release_clone_rq = io_err_release_clone_rq,
.io_hints = io_err_io_hints,
.direct_access = io_err_dax_direct_access,
};
int __init dm_target_init(void)
{
return dm_register_target(&error_target);
}
void dm_target_exit(void)
{
dm_unregister_target(&error_target);
}
| linux-master | drivers/md/dm-target.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2021 Western Digital Corporation or its affiliates.
*/
#include <linux/blkdev.h>
#include <linux/mm.h>
#include <linux/sched/mm.h>
#include <linux/slab.h>
#include <linux/bitmap.h>
#include "dm-core.h"
#define DM_MSG_PREFIX "zone"
#define DM_ZONE_INVALID_WP_OFST UINT_MAX
/*
* For internal zone reports bypassing the top BIO submission path.
*/
static int dm_blk_do_report_zones(struct mapped_device *md, struct dm_table *t,
sector_t sector, unsigned int nr_zones,
report_zones_cb cb, void *data)
{
struct gendisk *disk = md->disk;
int ret;
struct dm_report_zones_args args = {
.next_sector = sector,
.orig_data = data,
.orig_cb = cb,
};
do {
struct dm_target *tgt;
tgt = dm_table_find_target(t, args.next_sector);
if (WARN_ON_ONCE(!tgt->type->report_zones))
return -EIO;
args.tgt = tgt;
ret = tgt->type->report_zones(tgt, &args,
nr_zones - args.zone_idx);
if (ret < 0)
return ret;
} while (args.zone_idx < nr_zones &&
args.next_sector < get_capacity(disk));
return args.zone_idx;
}
/*
* User facing dm device block device report zone operation. This calls the
* report_zones operation for each target of a device table. This operation is
* generally implemented by targets using dm_report_zones().
*/
int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
unsigned int nr_zones, report_zones_cb cb, void *data)
{
struct mapped_device *md = disk->private_data;
struct dm_table *map;
int srcu_idx, ret;
if (dm_suspended_md(md))
return -EAGAIN;
map = dm_get_live_table(md, &srcu_idx);
if (!map)
return -EIO;
ret = dm_blk_do_report_zones(md, map, sector, nr_zones, cb, data);
dm_put_live_table(md, srcu_idx);
return ret;
}
static int dm_report_zones_cb(struct blk_zone *zone, unsigned int idx,
void *data)
{
struct dm_report_zones_args *args = data;
sector_t sector_diff = args->tgt->begin - args->start;
/*
* Ignore zones beyond the target range.
*/
if (zone->start >= args->start + args->tgt->len)
return 0;
/*
* Remap the start sector and write pointer position of the zone
* to match its position in the target range.
*/
zone->start += sector_diff;
if (zone->type != BLK_ZONE_TYPE_CONVENTIONAL) {
if (zone->cond == BLK_ZONE_COND_FULL)
zone->wp = zone->start + zone->len;
else if (zone->cond == BLK_ZONE_COND_EMPTY)
zone->wp = zone->start;
else
zone->wp += sector_diff;
}
args->next_sector = zone->start + zone->len;
return args->orig_cb(zone, args->zone_idx++, args->orig_data);
}
/*
* Helper for drivers of zoned targets to implement struct target_type
* report_zones operation.
*/
int dm_report_zones(struct block_device *bdev, sector_t start, sector_t sector,
struct dm_report_zones_args *args, unsigned int nr_zones)
{
/*
* Set the target mapping start sector first so that
* dm_report_zones_cb() can correctly remap zone information.
*/
args->start = start;
return blkdev_report_zones(bdev, sector, nr_zones,
dm_report_zones_cb, args);
}
EXPORT_SYMBOL_GPL(dm_report_zones);
bool dm_is_zone_write(struct mapped_device *md, struct bio *bio)
{
struct request_queue *q = md->queue;
if (!blk_queue_is_zoned(q))
return false;
switch (bio_op(bio)) {
case REQ_OP_WRITE_ZEROES:
case REQ_OP_WRITE:
return !op_is_flush(bio->bi_opf) && bio_sectors(bio);
default:
return false;
}
}
void dm_cleanup_zoned_dev(struct mapped_device *md)
{
if (md->disk) {
bitmap_free(md->disk->conv_zones_bitmap);
md->disk->conv_zones_bitmap = NULL;
bitmap_free(md->disk->seq_zones_wlock);
md->disk->seq_zones_wlock = NULL;
}
kvfree(md->zwp_offset);
md->zwp_offset = NULL;
md->nr_zones = 0;
}
static unsigned int dm_get_zone_wp_offset(struct blk_zone *zone)
{
switch (zone->cond) {
case BLK_ZONE_COND_IMP_OPEN:
case BLK_ZONE_COND_EXP_OPEN:
case BLK_ZONE_COND_CLOSED:
return zone->wp - zone->start;
case BLK_ZONE_COND_FULL:
return zone->len;
case BLK_ZONE_COND_EMPTY:
case BLK_ZONE_COND_NOT_WP:
case BLK_ZONE_COND_OFFLINE:
case BLK_ZONE_COND_READONLY:
default:
/*
* Conventional, offline and read-only zones do not have a valid
* write pointer. Use 0 as for an empty zone.
*/
return 0;
}
}
static int dm_zone_revalidate_cb(struct blk_zone *zone, unsigned int idx,
void *data)
{
struct mapped_device *md = data;
struct gendisk *disk = md->disk;
switch (zone->type) {
case BLK_ZONE_TYPE_CONVENTIONAL:
if (!disk->conv_zones_bitmap) {
disk->conv_zones_bitmap = bitmap_zalloc(disk->nr_zones,
GFP_NOIO);
if (!disk->conv_zones_bitmap)
return -ENOMEM;
}
set_bit(idx, disk->conv_zones_bitmap);
break;
case BLK_ZONE_TYPE_SEQWRITE_REQ:
case BLK_ZONE_TYPE_SEQWRITE_PREF:
if (!disk->seq_zones_wlock) {
disk->seq_zones_wlock = bitmap_zalloc(disk->nr_zones,
GFP_NOIO);
if (!disk->seq_zones_wlock)
return -ENOMEM;
}
if (!md->zwp_offset) {
md->zwp_offset =
kvcalloc(disk->nr_zones, sizeof(unsigned int),
GFP_KERNEL);
if (!md->zwp_offset)
return -ENOMEM;
}
md->zwp_offset[idx] = dm_get_zone_wp_offset(zone);
break;
default:
DMERR("Invalid zone type 0x%x at sectors %llu",
(int)zone->type, zone->start);
return -ENODEV;
}
return 0;
}
/*
* Revalidate the zones of a mapped device to initialize resource necessary
* for zone append emulation. Note that we cannot simply use the block layer
* blk_revalidate_disk_zones() function here as the mapped device is suspended
* (this is called from __bind() context).
*/
static int dm_revalidate_zones(struct mapped_device *md, struct dm_table *t)
{
struct gendisk *disk = md->disk;
unsigned int noio_flag;
int ret;
/*
* Check if something changed. If yes, cleanup the current resources
* and reallocate everything.
*/
if (!disk->nr_zones || disk->nr_zones != md->nr_zones)
dm_cleanup_zoned_dev(md);
if (md->nr_zones)
return 0;
/*
* Scan all zones to initialize everything. Ensure that all vmalloc
* operations in this context are done as if GFP_NOIO was specified.
*/
noio_flag = memalloc_noio_save();
ret = dm_blk_do_report_zones(md, t, 0, disk->nr_zones,
dm_zone_revalidate_cb, md);
memalloc_noio_restore(noio_flag);
if (ret < 0)
goto err;
if (ret != disk->nr_zones) {
ret = -EIO;
goto err;
}
md->nr_zones = disk->nr_zones;
return 0;
err:
DMERR("Revalidate zones failed %d", ret);
dm_cleanup_zoned_dev(md);
return ret;
}
static int device_not_zone_append_capable(struct dm_target *ti,
struct dm_dev *dev, sector_t start,
sector_t len, void *data)
{
return !bdev_is_zoned(dev->bdev);
}
static bool dm_table_supports_zone_append(struct dm_table *t)
{
for (unsigned int i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
if (ti->emulate_zone_append)
return false;
if (!ti->type->iterate_devices ||
ti->type->iterate_devices(ti, device_not_zone_append_capable, NULL))
return false;
}
return true;
}
int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q)
{
struct mapped_device *md = t->md;
/*
* For a zoned target, the number of zones should be updated for the
* correct value to be exposed in sysfs queue/nr_zones.
*/
WARN_ON_ONCE(queue_is_mq(q));
md->disk->nr_zones = bdev_nr_zones(md->disk->part0);
/* Check if zone append is natively supported */
if (dm_table_supports_zone_append(t)) {
clear_bit(DMF_EMULATE_ZONE_APPEND, &md->flags);
dm_cleanup_zoned_dev(md);
return 0;
}
/*
* Mark the mapped device as needing zone append emulation and
* initialize the emulation resources once the capacity is set.
*/
set_bit(DMF_EMULATE_ZONE_APPEND, &md->flags);
if (!get_capacity(md->disk))
return 0;
return dm_revalidate_zones(md, t);
}
static int dm_update_zone_wp_offset_cb(struct blk_zone *zone, unsigned int idx,
void *data)
{
unsigned int *wp_offset = data;
*wp_offset = dm_get_zone_wp_offset(zone);
return 0;
}
static int dm_update_zone_wp_offset(struct mapped_device *md, unsigned int zno,
unsigned int *wp_ofst)
{
sector_t sector = zno * bdev_zone_sectors(md->disk->part0);
unsigned int noio_flag;
struct dm_table *t;
int srcu_idx, ret;
t = dm_get_live_table(md, &srcu_idx);
if (!t)
return -EIO;
/*
* Ensure that all memory allocations in this context are done as if
* GFP_NOIO was specified.
*/
noio_flag = memalloc_noio_save();
ret = dm_blk_do_report_zones(md, t, sector, 1,
dm_update_zone_wp_offset_cb, wp_ofst);
memalloc_noio_restore(noio_flag);
dm_put_live_table(md, srcu_idx);
if (ret != 1)
return -EIO;
return 0;
}
struct orig_bio_details {
enum req_op op;
unsigned int nr_sectors;
};
/*
* First phase of BIO mapping for targets with zone append emulation:
* check all BIO that change a zone writer pointer and change zone
* append operations into regular write operations.
*/
static bool dm_zone_map_bio_begin(struct mapped_device *md,
unsigned int zno, struct bio *clone)
{
sector_t zsectors = bdev_zone_sectors(md->disk->part0);
unsigned int zwp_offset = READ_ONCE(md->zwp_offset[zno]);
/*
* If the target zone is in an error state, recover by inspecting the
* zone to get its current write pointer position. Note that since the
* target zone is already locked, a BIO issuing context should never
* see the zone write in the DM_ZONE_UPDATING_WP_OFST state.
*/
if (zwp_offset == DM_ZONE_INVALID_WP_OFST) {
if (dm_update_zone_wp_offset(md, zno, &zwp_offset))
return false;
WRITE_ONCE(md->zwp_offset[zno], zwp_offset);
}
switch (bio_op(clone)) {
case REQ_OP_ZONE_RESET:
case REQ_OP_ZONE_FINISH:
return true;
case REQ_OP_WRITE_ZEROES:
case REQ_OP_WRITE:
/* Writes must be aligned to the zone write pointer */
if ((clone->bi_iter.bi_sector & (zsectors - 1)) != zwp_offset)
return false;
break;
case REQ_OP_ZONE_APPEND:
/*
* Change zone append operations into a non-mergeable regular
* writes directed at the current write pointer position of the
* target zone.
*/
clone->bi_opf = REQ_OP_WRITE | REQ_NOMERGE |
(clone->bi_opf & (~REQ_OP_MASK));
clone->bi_iter.bi_sector += zwp_offset;
break;
default:
DMWARN_LIMIT("Invalid BIO operation");
return false;
}
/* Cannot write to a full zone */
if (zwp_offset >= zsectors)
return false;
return true;
}
/*
* Second phase of BIO mapping for targets with zone append emulation:
* update the zone write pointer offset array to account for the additional
* data written to a zone. Note that at this point, the remapped clone BIO
* may already have completed, so we do not touch it.
*/
static blk_status_t dm_zone_map_bio_end(struct mapped_device *md, unsigned int zno,
struct orig_bio_details *orig_bio_details,
unsigned int nr_sectors)
{
unsigned int zwp_offset = READ_ONCE(md->zwp_offset[zno]);
/* The clone BIO may already have been completed and failed */
if (zwp_offset == DM_ZONE_INVALID_WP_OFST)
return BLK_STS_IOERR;
/* Update the zone wp offset */
switch (orig_bio_details->op) {
case REQ_OP_ZONE_RESET:
WRITE_ONCE(md->zwp_offset[zno], 0);
return BLK_STS_OK;
case REQ_OP_ZONE_FINISH:
WRITE_ONCE(md->zwp_offset[zno],
bdev_zone_sectors(md->disk->part0));
return BLK_STS_OK;
case REQ_OP_WRITE_ZEROES:
case REQ_OP_WRITE:
WRITE_ONCE(md->zwp_offset[zno], zwp_offset + nr_sectors);
return BLK_STS_OK;
case REQ_OP_ZONE_APPEND:
/*
* Check that the target did not truncate the write operation
* emulating a zone append.
*/
if (nr_sectors != orig_bio_details->nr_sectors) {
DMWARN_LIMIT("Truncated write for zone append");
return BLK_STS_IOERR;
}
WRITE_ONCE(md->zwp_offset[zno], zwp_offset + nr_sectors);
return BLK_STS_OK;
default:
DMWARN_LIMIT("Invalid BIO operation");
return BLK_STS_IOERR;
}
}
static inline void dm_zone_lock(struct gendisk *disk, unsigned int zno,
struct bio *clone)
{
if (WARN_ON_ONCE(bio_flagged(clone, BIO_ZONE_WRITE_LOCKED)))
return;
wait_on_bit_lock_io(disk->seq_zones_wlock, zno, TASK_UNINTERRUPTIBLE);
bio_set_flag(clone, BIO_ZONE_WRITE_LOCKED);
}
static inline void dm_zone_unlock(struct gendisk *disk, unsigned int zno,
struct bio *clone)
{
if (!bio_flagged(clone, BIO_ZONE_WRITE_LOCKED))
return;
WARN_ON_ONCE(!test_bit(zno, disk->seq_zones_wlock));
clear_bit_unlock(zno, disk->seq_zones_wlock);
smp_mb__after_atomic();
wake_up_bit(disk->seq_zones_wlock, zno);
bio_clear_flag(clone, BIO_ZONE_WRITE_LOCKED);
}
static bool dm_need_zone_wp_tracking(struct bio *bio)
{
/*
* Special processing is not needed for operations that do not need the
* zone write lock, that is, all operations that target conventional
* zones and all operations that do not modify directly a sequential
* zone write pointer.
*/
if (op_is_flush(bio->bi_opf) && !bio_sectors(bio))
return false;
switch (bio_op(bio)) {
case REQ_OP_WRITE_ZEROES:
case REQ_OP_WRITE:
case REQ_OP_ZONE_RESET:
case REQ_OP_ZONE_FINISH:
case REQ_OP_ZONE_APPEND:
return bio_zone_is_seq(bio);
default:
return false;
}
}
/*
* Special IO mapping for targets needing zone append emulation.
*/
int dm_zone_map_bio(struct dm_target_io *tio)
{
struct dm_io *io = tio->io;
struct dm_target *ti = tio->ti;
struct mapped_device *md = io->md;
struct bio *clone = &tio->clone;
struct orig_bio_details orig_bio_details;
unsigned int zno;
blk_status_t sts;
int r;
/*
* IOs that do not change a zone write pointer do not need
* any additional special processing.
*/
if (!dm_need_zone_wp_tracking(clone))
return ti->type->map(ti, clone);
/* Lock the target zone */
zno = bio_zone_no(clone);
dm_zone_lock(md->disk, zno, clone);
orig_bio_details.nr_sectors = bio_sectors(clone);
orig_bio_details.op = bio_op(clone);
/*
* Check that the bio and the target zone write pointer offset are
* both valid, and if the bio is a zone append, remap it to a write.
*/
if (!dm_zone_map_bio_begin(md, zno, clone)) {
dm_zone_unlock(md->disk, zno, clone);
return DM_MAPIO_KILL;
}
/* Let the target do its work */
r = ti->type->map(ti, clone);
switch (r) {
case DM_MAPIO_SUBMITTED:
/*
* The target submitted the clone BIO. The target zone will
* be unlocked on completion of the clone.
*/
sts = dm_zone_map_bio_end(md, zno, &orig_bio_details,
*tio->len_ptr);
break;
case DM_MAPIO_REMAPPED:
/*
* The target only remapped the clone BIO. In case of error,
* unlock the target zone here as the clone will not be
* submitted.
*/
sts = dm_zone_map_bio_end(md, zno, &orig_bio_details,
*tio->len_ptr);
if (sts != BLK_STS_OK)
dm_zone_unlock(md->disk, zno, clone);
break;
case DM_MAPIO_REQUEUE:
case DM_MAPIO_KILL:
default:
dm_zone_unlock(md->disk, zno, clone);
sts = BLK_STS_IOERR;
break;
}
if (sts != BLK_STS_OK)
return DM_MAPIO_KILL;
return r;
}
/*
* IO completion callback called from clone_endio().
*/
void dm_zone_endio(struct dm_io *io, struct bio *clone)
{
struct mapped_device *md = io->md;
struct gendisk *disk = md->disk;
struct bio *orig_bio = io->orig_bio;
unsigned int zwp_offset;
unsigned int zno;
/*
* For targets that do not emulate zone append, we only need to
* handle native zone-append bios.
*/
if (!dm_emulate_zone_append(md)) {
/*
* Get the offset within the zone of the written sector
* and add that to the original bio sector position.
*/
if (clone->bi_status == BLK_STS_OK &&
bio_op(clone) == REQ_OP_ZONE_APPEND) {
sector_t mask =
(sector_t)bdev_zone_sectors(disk->part0) - 1;
orig_bio->bi_iter.bi_sector +=
clone->bi_iter.bi_sector & mask;
}
return;
}
/*
* For targets that do emulate zone append, if the clone BIO does not
* own the target zone write lock, we have nothing to do.
*/
if (!bio_flagged(clone, BIO_ZONE_WRITE_LOCKED))
return;
zno = bio_zone_no(orig_bio);
if (clone->bi_status != BLK_STS_OK) {
/*
* BIOs that modify a zone write pointer may leave the zone
* in an unknown state in case of failure (e.g. the write
* pointer was only partially advanced). In this case, set
* the target zone write pointer as invalid unless it is
* already being updated.
*/
WRITE_ONCE(md->zwp_offset[zno], DM_ZONE_INVALID_WP_OFST);
} else if (bio_op(orig_bio) == REQ_OP_ZONE_APPEND) {
/*
* Get the written sector for zone append operation that were
* emulated using regular write operations.
*/
zwp_offset = READ_ONCE(md->zwp_offset[zno]);
if (WARN_ON_ONCE(zwp_offset < bio_sectors(orig_bio)))
WRITE_ONCE(md->zwp_offset[zno],
DM_ZONE_INVALID_WP_OFST);
else
orig_bio->bi_iter.bi_sector +=
zwp_offset - bio_sectors(orig_bio);
}
dm_zone_unlock(disk, zno, clone);
}
| linux-master | drivers/md/dm-zone.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2003 Sistina Software (UK) Limited.
* Copyright (C) 2004, 2010-2011 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
#include <linux/device-mapper.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/bio.h>
#include <linux/slab.h>
#define DM_MSG_PREFIX "flakey"
#define PROBABILITY_BASE 1000000000
#define all_corrupt_bio_flags_match(bio, fc) \
(((bio)->bi_opf & (fc)->corrupt_bio_flags) == (fc)->corrupt_bio_flags)
/*
* Flakey: Used for testing only, simulates intermittent,
* catastrophic device failure.
*/
struct flakey_c {
struct dm_dev *dev;
unsigned long start_time;
sector_t start;
unsigned int up_interval;
unsigned int down_interval;
unsigned long flags;
unsigned int corrupt_bio_byte;
unsigned int corrupt_bio_rw;
unsigned int corrupt_bio_value;
blk_opf_t corrupt_bio_flags;
unsigned int random_read_corrupt;
unsigned int random_write_corrupt;
};
enum feature_flag_bits {
ERROR_READS,
DROP_WRITES,
ERROR_WRITES
};
struct per_bio_data {
bool bio_submitted;
};
static int parse_features(struct dm_arg_set *as, struct flakey_c *fc,
struct dm_target *ti)
{
int r;
unsigned int argc;
const char *arg_name;
static const struct dm_arg _args[] = {
{0, 11, "Invalid number of feature args"},
{1, UINT_MAX, "Invalid corrupt bio byte"},
{0, 255, "Invalid corrupt value to write into bio byte (0-255)"},
{0, UINT_MAX, "Invalid corrupt bio flags mask"},
{0, PROBABILITY_BASE, "Invalid random corrupt argument"},
};
/* No feature arguments supplied. */
if (!as->argc)
return 0;
r = dm_read_arg_group(_args, as, &argc, &ti->error);
if (r)
return r;
while (argc) {
arg_name = dm_shift_arg(as);
argc--;
if (!arg_name) {
ti->error = "Insufficient feature arguments";
return -EINVAL;
}
/*
* error_reads
*/
if (!strcasecmp(arg_name, "error_reads")) {
if (test_and_set_bit(ERROR_READS, &fc->flags)) {
ti->error = "Feature error_reads duplicated";
return -EINVAL;
}
continue;
}
/*
* drop_writes
*/
if (!strcasecmp(arg_name, "drop_writes")) {
if (test_and_set_bit(DROP_WRITES, &fc->flags)) {
ti->error = "Feature drop_writes duplicated";
return -EINVAL;
} else if (test_bit(ERROR_WRITES, &fc->flags)) {
ti->error = "Feature drop_writes conflicts with feature error_writes";
return -EINVAL;
}
continue;
}
/*
* error_writes
*/
if (!strcasecmp(arg_name, "error_writes")) {
if (test_and_set_bit(ERROR_WRITES, &fc->flags)) {
ti->error = "Feature error_writes duplicated";
return -EINVAL;
} else if (test_bit(DROP_WRITES, &fc->flags)) {
ti->error = "Feature error_writes conflicts with feature drop_writes";
return -EINVAL;
}
continue;
}
/*
* corrupt_bio_byte <Nth_byte> <direction> <value> <bio_flags>
*/
if (!strcasecmp(arg_name, "corrupt_bio_byte")) {
if (!argc) {
ti->error = "Feature corrupt_bio_byte requires parameters";
return -EINVAL;
}
r = dm_read_arg(_args + 1, as, &fc->corrupt_bio_byte, &ti->error);
if (r)
return r;
argc--;
/*
* Direction r or w?
*/
arg_name = dm_shift_arg(as);
if (arg_name && !strcasecmp(arg_name, "w"))
fc->corrupt_bio_rw = WRITE;
else if (arg_name && !strcasecmp(arg_name, "r"))
fc->corrupt_bio_rw = READ;
else {
ti->error = "Invalid corrupt bio direction (r or w)";
return -EINVAL;
}
argc--;
/*
* Value of byte (0-255) to write in place of correct one.
*/
r = dm_read_arg(_args + 2, as, &fc->corrupt_bio_value, &ti->error);
if (r)
return r;
argc--;
/*
* Only corrupt bios with these flags set.
*/
BUILD_BUG_ON(sizeof(fc->corrupt_bio_flags) !=
sizeof(unsigned int));
r = dm_read_arg(_args + 3, as,
(__force unsigned int *)&fc->corrupt_bio_flags,
&ti->error);
if (r)
return r;
argc--;
continue;
}
if (!strcasecmp(arg_name, "random_read_corrupt")) {
if (!argc) {
ti->error = "Feature random_read_corrupt requires a parameter";
return -EINVAL;
}
r = dm_read_arg(_args + 4, as, &fc->random_read_corrupt, &ti->error);
if (r)
return r;
argc--;
continue;
}
if (!strcasecmp(arg_name, "random_write_corrupt")) {
if (!argc) {
ti->error = "Feature random_write_corrupt requires a parameter";
return -EINVAL;
}
r = dm_read_arg(_args + 4, as, &fc->random_write_corrupt, &ti->error);
if (r)
return r;
argc--;
continue;
}
ti->error = "Unrecognised flakey feature requested";
return -EINVAL;
}
if (test_bit(DROP_WRITES, &fc->flags) && (fc->corrupt_bio_rw == WRITE)) {
ti->error = "drop_writes is incompatible with corrupt_bio_byte with the WRITE flag set";
return -EINVAL;
} else if (test_bit(ERROR_WRITES, &fc->flags) && (fc->corrupt_bio_rw == WRITE)) {
ti->error = "error_writes is incompatible with corrupt_bio_byte with the WRITE flag set";
return -EINVAL;
}
if (!fc->corrupt_bio_byte && !test_bit(ERROR_READS, &fc->flags) &&
!test_bit(DROP_WRITES, &fc->flags) && !test_bit(ERROR_WRITES, &fc->flags) &&
!fc->random_read_corrupt && !fc->random_write_corrupt) {
set_bit(ERROR_WRITES, &fc->flags);
set_bit(ERROR_READS, &fc->flags);
}
return 0;
}
/*
* Construct a flakey mapping:
* <dev_path> <offset> <up interval> <down interval> [<#feature args> [<arg>]*]
*
* Feature args:
* [drop_writes]
* [corrupt_bio_byte <Nth_byte> <direction> <value> <bio_flags>]
*
* Nth_byte starts from 1 for the first byte.
* Direction is r for READ or w for WRITE.
* bio_flags is ignored if 0.
*/
static int flakey_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
static const struct dm_arg _args[] = {
{0, UINT_MAX, "Invalid up interval"},
{0, UINT_MAX, "Invalid down interval"},
};
int r;
struct flakey_c *fc;
unsigned long long tmpll;
struct dm_arg_set as;
const char *devname;
char dummy;
as.argc = argc;
as.argv = argv;
if (argc < 4) {
ti->error = "Invalid argument count";
return -EINVAL;
}
fc = kzalloc(sizeof(*fc), GFP_KERNEL);
if (!fc) {
ti->error = "Cannot allocate context";
return -ENOMEM;
}
fc->start_time = jiffies;
devname = dm_shift_arg(&as);
r = -EINVAL;
if (sscanf(dm_shift_arg(&as), "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) {
ti->error = "Invalid device sector";
goto bad;
}
fc->start = tmpll;
r = dm_read_arg(_args, &as, &fc->up_interval, &ti->error);
if (r)
goto bad;
r = dm_read_arg(_args, &as, &fc->down_interval, &ti->error);
if (r)
goto bad;
if (!(fc->up_interval + fc->down_interval)) {
ti->error = "Total (up + down) interval is zero";
r = -EINVAL;
goto bad;
}
if (fc->up_interval + fc->down_interval < fc->up_interval) {
ti->error = "Interval overflow";
r = -EINVAL;
goto bad;
}
r = parse_features(&as, fc, ti);
if (r)
goto bad;
r = dm_get_device(ti, devname, dm_table_get_mode(ti->table), &fc->dev);
if (r) {
ti->error = "Device lookup failed";
goto bad;
}
ti->num_flush_bios = 1;
ti->num_discard_bios = 1;
ti->per_io_data_size = sizeof(struct per_bio_data);
ti->private = fc;
return 0;
bad:
kfree(fc);
return r;
}
static void flakey_dtr(struct dm_target *ti)
{
struct flakey_c *fc = ti->private;
dm_put_device(ti, fc->dev);
kfree(fc);
}
static sector_t flakey_map_sector(struct dm_target *ti, sector_t bi_sector)
{
struct flakey_c *fc = ti->private;
return fc->start + dm_target_offset(ti, bi_sector);
}
static void flakey_map_bio(struct dm_target *ti, struct bio *bio)
{
struct flakey_c *fc = ti->private;
bio_set_dev(bio, fc->dev->bdev);
bio->bi_iter.bi_sector = flakey_map_sector(ti, bio->bi_iter.bi_sector);
}
static void corrupt_bio_common(struct bio *bio, unsigned int corrupt_bio_byte,
unsigned char corrupt_bio_value)
{
struct bvec_iter iter;
struct bio_vec bvec;
/*
* Overwrite the Nth byte of the bio's data, on whichever page
* it falls.
*/
bio_for_each_segment(bvec, bio, iter) {
if (bio_iter_len(bio, iter) > corrupt_bio_byte) {
unsigned char *segment = bvec_kmap_local(&bvec);
segment[corrupt_bio_byte] = corrupt_bio_value;
kunmap_local(segment);
DMDEBUG("Corrupting data bio=%p by writing %u to byte %u "
"(rw=%c bi_opf=%u bi_sector=%llu size=%u)\n",
bio, corrupt_bio_value, corrupt_bio_byte,
(bio_data_dir(bio) == WRITE) ? 'w' : 'r', bio->bi_opf,
(unsigned long long)bio->bi_iter.bi_sector,
bio->bi_iter.bi_size);
break;
}
corrupt_bio_byte -= bio_iter_len(bio, iter);
}
}
static void corrupt_bio_data(struct bio *bio, struct flakey_c *fc)
{
unsigned int corrupt_bio_byte = fc->corrupt_bio_byte - 1;
if (!bio_has_data(bio))
return;
corrupt_bio_common(bio, corrupt_bio_byte, fc->corrupt_bio_value);
}
static void corrupt_bio_random(struct bio *bio)
{
unsigned int corrupt_byte;
unsigned char corrupt_value;
if (!bio_has_data(bio))
return;
corrupt_byte = get_random_u32() % bio->bi_iter.bi_size;
corrupt_value = get_random_u8();
corrupt_bio_common(bio, corrupt_byte, corrupt_value);
}
static void clone_free(struct bio *clone)
{
struct folio_iter fi;
if (clone->bi_vcnt > 0) { /* bio_for_each_folio_all crashes with an empty bio */
bio_for_each_folio_all(fi, clone)
folio_put(fi.folio);
}
bio_uninit(clone);
kfree(clone);
}
static void clone_endio(struct bio *clone)
{
struct bio *bio = clone->bi_private;
bio->bi_status = clone->bi_status;
clone_free(clone);
bio_endio(bio);
}
static struct bio *clone_bio(struct dm_target *ti, struct flakey_c *fc, struct bio *bio)
{
struct bio *clone;
unsigned size, remaining_size, nr_iovecs, order;
struct bvec_iter iter = bio->bi_iter;
if (unlikely(bio->bi_iter.bi_size > UIO_MAXIOV << PAGE_SHIFT))
dm_accept_partial_bio(bio, UIO_MAXIOV << PAGE_SHIFT >> SECTOR_SHIFT);
size = bio->bi_iter.bi_size;
nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
clone = bio_kmalloc(nr_iovecs, GFP_NOIO | __GFP_NORETRY | __GFP_NOWARN);
if (!clone)
return NULL;
bio_init(clone, fc->dev->bdev, bio->bi_inline_vecs, nr_iovecs, bio->bi_opf);
clone->bi_iter.bi_sector = flakey_map_sector(ti, bio->bi_iter.bi_sector);
clone->bi_private = bio;
clone->bi_end_io = clone_endio;
remaining_size = size;
order = MAX_ORDER - 1;
while (remaining_size) {
struct page *pages;
unsigned size_to_add, to_copy;
unsigned char *virt;
unsigned remaining_order = __fls((remaining_size + PAGE_SIZE - 1) >> PAGE_SHIFT);
order = min(order, remaining_order);
retry_alloc_pages:
pages = alloc_pages(GFP_NOIO | __GFP_NORETRY | __GFP_NOWARN | __GFP_COMP, order);
if (unlikely(!pages)) {
if (order) {
order--;
goto retry_alloc_pages;
}
clone_free(clone);
return NULL;
}
size_to_add = min((unsigned)PAGE_SIZE << order, remaining_size);
virt = page_to_virt(pages);
to_copy = size_to_add;
do {
struct bio_vec bvec = bvec_iter_bvec(bio->bi_io_vec, iter);
unsigned this_step = min(bvec.bv_len, to_copy);
void *map = bvec_kmap_local(&bvec);
memcpy(virt, map, this_step);
kunmap_local(map);
bvec_iter_advance(bio->bi_io_vec, &iter, this_step);
to_copy -= this_step;
virt += this_step;
} while (to_copy);
__bio_add_page(clone, pages, size_to_add, 0);
remaining_size -= size_to_add;
}
return clone;
}
static int flakey_map(struct dm_target *ti, struct bio *bio)
{
struct flakey_c *fc = ti->private;
unsigned int elapsed;
struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data));
pb->bio_submitted = false;
if (op_is_zone_mgmt(bio_op(bio)))
goto map_bio;
/* Are we alive ? */
elapsed = (jiffies - fc->start_time) / HZ;
if (elapsed % (fc->up_interval + fc->down_interval) >= fc->up_interval) {
bool corrupt_fixed, corrupt_random;
/*
* Flag this bio as submitted while down.
*/
pb->bio_submitted = true;
/*
* Error reads if neither corrupt_bio_byte or drop_writes or error_writes are set.
* Otherwise, flakey_end_io() will decide if the reads should be modified.
*/
if (bio_data_dir(bio) == READ) {
if (test_bit(ERROR_READS, &fc->flags))
return DM_MAPIO_KILL;
goto map_bio;
}
/*
* Drop or error writes?
*/
if (test_bit(DROP_WRITES, &fc->flags)) {
bio_endio(bio);
return DM_MAPIO_SUBMITTED;
} else if (test_bit(ERROR_WRITES, &fc->flags)) {
bio_io_error(bio);
return DM_MAPIO_SUBMITTED;
}
/*
* Corrupt matching writes.
*/
corrupt_fixed = false;
corrupt_random = false;
if (fc->corrupt_bio_byte && fc->corrupt_bio_rw == WRITE) {
if (all_corrupt_bio_flags_match(bio, fc))
corrupt_fixed = true;
}
if (fc->random_write_corrupt) {
u64 rnd = get_random_u64();
u32 rem = do_div(rnd, PROBABILITY_BASE);
if (rem < fc->random_write_corrupt)
corrupt_random = true;
}
if (corrupt_fixed || corrupt_random) {
struct bio *clone = clone_bio(ti, fc, bio);
if (clone) {
if (corrupt_fixed)
corrupt_bio_data(clone, fc);
if (corrupt_random)
corrupt_bio_random(clone);
submit_bio(clone);
return DM_MAPIO_SUBMITTED;
}
}
}
map_bio:
flakey_map_bio(ti, bio);
return DM_MAPIO_REMAPPED;
}
static int flakey_end_io(struct dm_target *ti, struct bio *bio,
blk_status_t *error)
{
struct flakey_c *fc = ti->private;
struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data));
if (op_is_zone_mgmt(bio_op(bio)))
return DM_ENDIO_DONE;
if (!*error && pb->bio_submitted && (bio_data_dir(bio) == READ)) {
if (fc->corrupt_bio_byte) {
if ((fc->corrupt_bio_rw == READ) &&
all_corrupt_bio_flags_match(bio, fc)) {
/*
* Corrupt successful matching READs while in down state.
*/
corrupt_bio_data(bio, fc);
}
}
if (fc->random_read_corrupt) {
u64 rnd = get_random_u64();
u32 rem = do_div(rnd, PROBABILITY_BASE);
if (rem < fc->random_read_corrupt)
corrupt_bio_random(bio);
}
if (test_bit(ERROR_READS, &fc->flags)) {
/*
* Error read during the down_interval if drop_writes
* and error_writes were not configured.
*/
*error = BLK_STS_IOERR;
}
}
return DM_ENDIO_DONE;
}
static void flakey_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
unsigned int sz = 0;
struct flakey_c *fc = ti->private;
unsigned int error_reads, drop_writes, error_writes;
switch (type) {
case STATUSTYPE_INFO:
result[0] = '\0';
break;
case STATUSTYPE_TABLE:
DMEMIT("%s %llu %u %u", fc->dev->name,
(unsigned long long)fc->start, fc->up_interval,
fc->down_interval);
error_reads = test_bit(ERROR_READS, &fc->flags);
drop_writes = test_bit(DROP_WRITES, &fc->flags);
error_writes = test_bit(ERROR_WRITES, &fc->flags);
DMEMIT(" %u", error_reads + drop_writes + error_writes +
(fc->corrupt_bio_byte > 0) * 5 +
(fc->random_read_corrupt > 0) * 2 +
(fc->random_write_corrupt > 0) * 2);
if (error_reads)
DMEMIT(" error_reads");
if (drop_writes)
DMEMIT(" drop_writes");
else if (error_writes)
DMEMIT(" error_writes");
if (fc->corrupt_bio_byte)
DMEMIT(" corrupt_bio_byte %u %c %u %u",
fc->corrupt_bio_byte,
(fc->corrupt_bio_rw == WRITE) ? 'w' : 'r',
fc->corrupt_bio_value, fc->corrupt_bio_flags);
if (fc->random_read_corrupt > 0)
DMEMIT(" random_read_corrupt %u", fc->random_read_corrupt);
if (fc->random_write_corrupt > 0)
DMEMIT(" random_write_corrupt %u", fc->random_write_corrupt);
break;
case STATUSTYPE_IMA:
result[0] = '\0';
break;
}
}
static int flakey_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
{
struct flakey_c *fc = ti->private;
*bdev = fc->dev->bdev;
/*
* Only pass ioctls through if the device sizes match exactly.
*/
if (fc->start || ti->len != bdev_nr_sectors((*bdev)))
return 1;
return 0;
}
#ifdef CONFIG_BLK_DEV_ZONED
static int flakey_report_zones(struct dm_target *ti,
struct dm_report_zones_args *args, unsigned int nr_zones)
{
struct flakey_c *fc = ti->private;
return dm_report_zones(fc->dev->bdev, fc->start,
flakey_map_sector(ti, args->next_sector),
args, nr_zones);
}
#else
#define flakey_report_zones NULL
#endif
static int flakey_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
{
struct flakey_c *fc = ti->private;
return fn(ti, fc->dev, fc->start, ti->len, data);
}
static struct target_type flakey_target = {
.name = "flakey",
.version = {1, 5, 0},
.features = DM_TARGET_ZONED_HM | DM_TARGET_PASSES_CRYPTO,
.report_zones = flakey_report_zones,
.module = THIS_MODULE,
.ctr = flakey_ctr,
.dtr = flakey_dtr,
.map = flakey_map,
.end_io = flakey_end_io,
.status = flakey_status,
.prepare_ioctl = flakey_prepare_ioctl,
.iterate_devices = flakey_iterate_devices,
};
module_dm(flakey);
MODULE_DESCRIPTION(DM_NAME " flakey target");
MODULE_AUTHOR("Joe Thornber <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-flakey.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2017 Western Digital Corporation or its affiliates.
*
* This file is released under the GPL.
*/
#include "dm-zoned.h"
#include <linux/module.h>
#define DM_MSG_PREFIX "zoned"
#define DMZ_MIN_BIOS 8192
/*
* Zone BIO context.
*/
struct dmz_bioctx {
struct dmz_dev *dev;
struct dm_zone *zone;
struct bio *bio;
refcount_t ref;
};
/*
* Chunk work descriptor.
*/
struct dm_chunk_work {
struct work_struct work;
refcount_t refcount;
struct dmz_target *target;
unsigned int chunk;
struct bio_list bio_list;
};
/*
* Target descriptor.
*/
struct dmz_target {
struct dm_dev **ddev;
unsigned int nr_ddevs;
unsigned int flags;
/* Zoned block device information */
struct dmz_dev *dev;
/* For metadata handling */
struct dmz_metadata *metadata;
/* For chunk work */
struct radix_tree_root chunk_rxtree;
struct workqueue_struct *chunk_wq;
struct mutex chunk_lock;
/* For cloned BIOs to zones */
struct bio_set bio_set;
/* For flush */
spinlock_t flush_lock;
struct bio_list flush_list;
struct delayed_work flush_work;
struct workqueue_struct *flush_wq;
};
/*
* Flush intervals (seconds).
*/
#define DMZ_FLUSH_PERIOD (10 * HZ)
/*
* Target BIO completion.
*/
static inline void dmz_bio_endio(struct bio *bio, blk_status_t status)
{
struct dmz_bioctx *bioctx =
dm_per_bio_data(bio, sizeof(struct dmz_bioctx));
if (status != BLK_STS_OK && bio->bi_status == BLK_STS_OK)
bio->bi_status = status;
if (bioctx->dev && bio->bi_status != BLK_STS_OK)
bioctx->dev->flags |= DMZ_CHECK_BDEV;
if (refcount_dec_and_test(&bioctx->ref)) {
struct dm_zone *zone = bioctx->zone;
if (zone) {
if (bio->bi_status != BLK_STS_OK &&
bio_op(bio) == REQ_OP_WRITE &&
dmz_is_seq(zone))
set_bit(DMZ_SEQ_WRITE_ERR, &zone->flags);
dmz_deactivate_zone(zone);
}
bio_endio(bio);
}
}
/*
* Completion callback for an internally cloned target BIO. This terminates the
* target BIO when there are no more references to its context.
*/
static void dmz_clone_endio(struct bio *clone)
{
struct dmz_bioctx *bioctx = clone->bi_private;
blk_status_t status = clone->bi_status;
bio_put(clone);
dmz_bio_endio(bioctx->bio, status);
}
/*
* Issue a clone of a target BIO. The clone may only partially process the
* original target BIO.
*/
static int dmz_submit_bio(struct dmz_target *dmz, struct dm_zone *zone,
struct bio *bio, sector_t chunk_block,
unsigned int nr_blocks)
{
struct dmz_bioctx *bioctx =
dm_per_bio_data(bio, sizeof(struct dmz_bioctx));
struct dmz_dev *dev = zone->dev;
struct bio *clone;
if (dev->flags & DMZ_BDEV_DYING)
return -EIO;
clone = bio_alloc_clone(dev->bdev, bio, GFP_NOIO, &dmz->bio_set);
if (!clone)
return -ENOMEM;
bioctx->dev = dev;
clone->bi_iter.bi_sector =
dmz_start_sect(dmz->metadata, zone) + dmz_blk2sect(chunk_block);
clone->bi_iter.bi_size = dmz_blk2sect(nr_blocks) << SECTOR_SHIFT;
clone->bi_end_io = dmz_clone_endio;
clone->bi_private = bioctx;
bio_advance(bio, clone->bi_iter.bi_size);
refcount_inc(&bioctx->ref);
submit_bio_noacct(clone);
if (bio_op(bio) == REQ_OP_WRITE && dmz_is_seq(zone))
zone->wp_block += nr_blocks;
return 0;
}
/*
* Zero out pages of discarded blocks accessed by a read BIO.
*/
static void dmz_handle_read_zero(struct dmz_target *dmz, struct bio *bio,
sector_t chunk_block, unsigned int nr_blocks)
{
unsigned int size = nr_blocks << DMZ_BLOCK_SHIFT;
/* Clear nr_blocks */
swap(bio->bi_iter.bi_size, size);
zero_fill_bio(bio);
swap(bio->bi_iter.bi_size, size);
bio_advance(bio, size);
}
/*
* Process a read BIO.
*/
static int dmz_handle_read(struct dmz_target *dmz, struct dm_zone *zone,
struct bio *bio)
{
struct dmz_metadata *zmd = dmz->metadata;
sector_t chunk_block = dmz_chunk_block(zmd, dmz_bio_block(bio));
unsigned int nr_blocks = dmz_bio_blocks(bio);
sector_t end_block = chunk_block + nr_blocks;
struct dm_zone *rzone, *bzone;
int ret;
/* Read into unmapped chunks need only zeroing the BIO buffer */
if (!zone) {
zero_fill_bio(bio);
return 0;
}
DMDEBUG("(%s): READ chunk %llu -> %s zone %u, block %llu, %u blocks",
dmz_metadata_label(zmd),
(unsigned long long)dmz_bio_chunk(zmd, bio),
(dmz_is_rnd(zone) ? "RND" :
(dmz_is_cache(zone) ? "CACHE" : "SEQ")),
zone->id,
(unsigned long long)chunk_block, nr_blocks);
/* Check block validity to determine the read location */
bzone = zone->bzone;
while (chunk_block < end_block) {
nr_blocks = 0;
if (dmz_is_rnd(zone) || dmz_is_cache(zone) ||
chunk_block < zone->wp_block) {
/* Test block validity in the data zone */
ret = dmz_block_valid(zmd, zone, chunk_block);
if (ret < 0)
return ret;
if (ret > 0) {
/* Read data zone blocks */
nr_blocks = ret;
rzone = zone;
}
}
/*
* No valid blocks found in the data zone.
* Check the buffer zone, if there is one.
*/
if (!nr_blocks && bzone) {
ret = dmz_block_valid(zmd, bzone, chunk_block);
if (ret < 0)
return ret;
if (ret > 0) {
/* Read buffer zone blocks */
nr_blocks = ret;
rzone = bzone;
}
}
if (nr_blocks) {
/* Valid blocks found: read them */
nr_blocks = min_t(unsigned int, nr_blocks,
end_block - chunk_block);
ret = dmz_submit_bio(dmz, rzone, bio,
chunk_block, nr_blocks);
if (ret)
return ret;
chunk_block += nr_blocks;
} else {
/* No valid block: zeroout the current BIO block */
dmz_handle_read_zero(dmz, bio, chunk_block, 1);
chunk_block++;
}
}
return 0;
}
/*
* Write blocks directly in a data zone, at the write pointer.
* If a buffer zone is assigned, invalidate the blocks written
* in place.
*/
static int dmz_handle_direct_write(struct dmz_target *dmz,
struct dm_zone *zone, struct bio *bio,
sector_t chunk_block,
unsigned int nr_blocks)
{
struct dmz_metadata *zmd = dmz->metadata;
struct dm_zone *bzone = zone->bzone;
int ret;
if (dmz_is_readonly(zone))
return -EROFS;
/* Submit write */
ret = dmz_submit_bio(dmz, zone, bio, chunk_block, nr_blocks);
if (ret)
return ret;
/*
* Validate the blocks in the data zone and invalidate
* in the buffer zone, if there is one.
*/
ret = dmz_validate_blocks(zmd, zone, chunk_block, nr_blocks);
if (ret == 0 && bzone)
ret = dmz_invalidate_blocks(zmd, bzone, chunk_block, nr_blocks);
return ret;
}
/*
* Write blocks in the buffer zone of @zone.
* If no buffer zone is assigned yet, get one.
* Called with @zone write locked.
*/
static int dmz_handle_buffered_write(struct dmz_target *dmz,
struct dm_zone *zone, struct bio *bio,
sector_t chunk_block,
unsigned int nr_blocks)
{
struct dmz_metadata *zmd = dmz->metadata;
struct dm_zone *bzone;
int ret;
/* Get the buffer zone. One will be allocated if needed */
bzone = dmz_get_chunk_buffer(zmd, zone);
if (IS_ERR(bzone))
return PTR_ERR(bzone);
if (dmz_is_readonly(bzone))
return -EROFS;
/* Submit write */
ret = dmz_submit_bio(dmz, bzone, bio, chunk_block, nr_blocks);
if (ret)
return ret;
/*
* Validate the blocks in the buffer zone
* and invalidate in the data zone.
*/
ret = dmz_validate_blocks(zmd, bzone, chunk_block, nr_blocks);
if (ret == 0 && chunk_block < zone->wp_block)
ret = dmz_invalidate_blocks(zmd, zone, chunk_block, nr_blocks);
return ret;
}
/*
* Process a write BIO.
*/
static int dmz_handle_write(struct dmz_target *dmz, struct dm_zone *zone,
struct bio *bio)
{
struct dmz_metadata *zmd = dmz->metadata;
sector_t chunk_block = dmz_chunk_block(zmd, dmz_bio_block(bio));
unsigned int nr_blocks = dmz_bio_blocks(bio);
if (!zone)
return -ENOSPC;
DMDEBUG("(%s): WRITE chunk %llu -> %s zone %u, block %llu, %u blocks",
dmz_metadata_label(zmd),
(unsigned long long)dmz_bio_chunk(zmd, bio),
(dmz_is_rnd(zone) ? "RND" :
(dmz_is_cache(zone) ? "CACHE" : "SEQ")),
zone->id,
(unsigned long long)chunk_block, nr_blocks);
if (dmz_is_rnd(zone) || dmz_is_cache(zone) ||
chunk_block == zone->wp_block) {
/*
* zone is a random zone or it is a sequential zone
* and the BIO is aligned to the zone write pointer:
* direct write the zone.
*/
return dmz_handle_direct_write(dmz, zone, bio,
chunk_block, nr_blocks);
}
/*
* This is an unaligned write in a sequential zone:
* use buffered write.
*/
return dmz_handle_buffered_write(dmz, zone, bio, chunk_block, nr_blocks);
}
/*
* Process a discard BIO.
*/
static int dmz_handle_discard(struct dmz_target *dmz, struct dm_zone *zone,
struct bio *bio)
{
struct dmz_metadata *zmd = dmz->metadata;
sector_t block = dmz_bio_block(bio);
unsigned int nr_blocks = dmz_bio_blocks(bio);
sector_t chunk_block = dmz_chunk_block(zmd, block);
int ret = 0;
/* For unmapped chunks, there is nothing to do */
if (!zone)
return 0;
if (dmz_is_readonly(zone))
return -EROFS;
DMDEBUG("(%s): DISCARD chunk %llu -> zone %u, block %llu, %u blocks",
dmz_metadata_label(dmz->metadata),
(unsigned long long)dmz_bio_chunk(zmd, bio),
zone->id,
(unsigned long long)chunk_block, nr_blocks);
/*
* Invalidate blocks in the data zone and its
* buffer zone if one is mapped.
*/
if (dmz_is_rnd(zone) || dmz_is_cache(zone) ||
chunk_block < zone->wp_block)
ret = dmz_invalidate_blocks(zmd, zone, chunk_block, nr_blocks);
if (ret == 0 && zone->bzone)
ret = dmz_invalidate_blocks(zmd, zone->bzone,
chunk_block, nr_blocks);
return ret;
}
/*
* Process a BIO.
*/
static void dmz_handle_bio(struct dmz_target *dmz, struct dm_chunk_work *cw,
struct bio *bio)
{
struct dmz_bioctx *bioctx =
dm_per_bio_data(bio, sizeof(struct dmz_bioctx));
struct dmz_metadata *zmd = dmz->metadata;
struct dm_zone *zone;
int ret;
dmz_lock_metadata(zmd);
/*
* Get the data zone mapping the chunk. There may be no
* mapping for read and discard. If a mapping is obtained,
+ the zone returned will be set to active state.
*/
zone = dmz_get_chunk_mapping(zmd, dmz_bio_chunk(zmd, bio),
bio_op(bio));
if (IS_ERR(zone)) {
ret = PTR_ERR(zone);
goto out;
}
/* Process the BIO */
if (zone) {
dmz_activate_zone(zone);
bioctx->zone = zone;
dmz_reclaim_bio_acc(zone->dev->reclaim);
}
switch (bio_op(bio)) {
case REQ_OP_READ:
ret = dmz_handle_read(dmz, zone, bio);
break;
case REQ_OP_WRITE:
ret = dmz_handle_write(dmz, zone, bio);
break;
case REQ_OP_DISCARD:
case REQ_OP_WRITE_ZEROES:
ret = dmz_handle_discard(dmz, zone, bio);
break;
default:
DMERR("(%s): Unsupported BIO operation 0x%x",
dmz_metadata_label(dmz->metadata), bio_op(bio));
ret = -EIO;
}
/*
* Release the chunk mapping. This will check that the mapping
* is still valid, that is, that the zone used still has valid blocks.
*/
if (zone)
dmz_put_chunk_mapping(zmd, zone);
out:
dmz_bio_endio(bio, errno_to_blk_status(ret));
dmz_unlock_metadata(zmd);
}
/*
* Increment a chunk reference counter.
*/
static inline void dmz_get_chunk_work(struct dm_chunk_work *cw)
{
refcount_inc(&cw->refcount);
}
/*
* Decrement a chunk work reference count and
* free it if it becomes 0.
*/
static void dmz_put_chunk_work(struct dm_chunk_work *cw)
{
if (refcount_dec_and_test(&cw->refcount)) {
WARN_ON(!bio_list_empty(&cw->bio_list));
radix_tree_delete(&cw->target->chunk_rxtree, cw->chunk);
kfree(cw);
}
}
/*
* Chunk BIO work function.
*/
static void dmz_chunk_work(struct work_struct *work)
{
struct dm_chunk_work *cw = container_of(work, struct dm_chunk_work, work);
struct dmz_target *dmz = cw->target;
struct bio *bio;
mutex_lock(&dmz->chunk_lock);
/* Process the chunk BIOs */
while ((bio = bio_list_pop(&cw->bio_list))) {
mutex_unlock(&dmz->chunk_lock);
dmz_handle_bio(dmz, cw, bio);
mutex_lock(&dmz->chunk_lock);
dmz_put_chunk_work(cw);
}
/* Queueing the work incremented the work refcount */
dmz_put_chunk_work(cw);
mutex_unlock(&dmz->chunk_lock);
}
/*
* Flush work.
*/
static void dmz_flush_work(struct work_struct *work)
{
struct dmz_target *dmz = container_of(work, struct dmz_target, flush_work.work);
struct bio *bio;
int ret;
/* Flush dirty metadata blocks */
ret = dmz_flush_metadata(dmz->metadata);
if (ret)
DMDEBUG("(%s): Metadata flush failed, rc=%d",
dmz_metadata_label(dmz->metadata), ret);
/* Process queued flush requests */
while (1) {
spin_lock(&dmz->flush_lock);
bio = bio_list_pop(&dmz->flush_list);
spin_unlock(&dmz->flush_lock);
if (!bio)
break;
dmz_bio_endio(bio, errno_to_blk_status(ret));
}
queue_delayed_work(dmz->flush_wq, &dmz->flush_work, DMZ_FLUSH_PERIOD);
}
/*
* Get a chunk work and start it to process a new BIO.
* If the BIO chunk has no work yet, create one.
*/
static int dmz_queue_chunk_work(struct dmz_target *dmz, struct bio *bio)
{
unsigned int chunk = dmz_bio_chunk(dmz->metadata, bio);
struct dm_chunk_work *cw;
int ret = 0;
mutex_lock(&dmz->chunk_lock);
/* Get the BIO chunk work. If one is not active yet, create one */
cw = radix_tree_lookup(&dmz->chunk_rxtree, chunk);
if (cw) {
dmz_get_chunk_work(cw);
} else {
/* Create a new chunk work */
cw = kmalloc(sizeof(struct dm_chunk_work), GFP_NOIO);
if (unlikely(!cw)) {
ret = -ENOMEM;
goto out;
}
INIT_WORK(&cw->work, dmz_chunk_work);
refcount_set(&cw->refcount, 1);
cw->target = dmz;
cw->chunk = chunk;
bio_list_init(&cw->bio_list);
ret = radix_tree_insert(&dmz->chunk_rxtree, chunk, cw);
if (unlikely(ret)) {
kfree(cw);
goto out;
}
}
bio_list_add(&cw->bio_list, bio);
if (queue_work(dmz->chunk_wq, &cw->work))
dmz_get_chunk_work(cw);
out:
mutex_unlock(&dmz->chunk_lock);
return ret;
}
/*
* Check if the backing device is being removed. If it's on the way out,
* start failing I/O. Reclaim and metadata components also call this
* function to cleanly abort operation in the event of such failure.
*/
bool dmz_bdev_is_dying(struct dmz_dev *dmz_dev)
{
if (dmz_dev->flags & DMZ_BDEV_DYING)
return true;
if (dmz_dev->flags & DMZ_CHECK_BDEV)
return !dmz_check_bdev(dmz_dev);
if (blk_queue_dying(bdev_get_queue(dmz_dev->bdev))) {
dmz_dev_warn(dmz_dev, "Backing device queue dying");
dmz_dev->flags |= DMZ_BDEV_DYING;
}
return dmz_dev->flags & DMZ_BDEV_DYING;
}
/*
* Check the backing device availability. This detects such events as
* backing device going offline due to errors, media removals, etc.
* This check is less efficient than dmz_bdev_is_dying() and should
* only be performed as a part of error handling.
*/
bool dmz_check_bdev(struct dmz_dev *dmz_dev)
{
struct gendisk *disk;
dmz_dev->flags &= ~DMZ_CHECK_BDEV;
if (dmz_bdev_is_dying(dmz_dev))
return false;
disk = dmz_dev->bdev->bd_disk;
if (disk->fops->check_events &&
disk->fops->check_events(disk, 0) & DISK_EVENT_MEDIA_CHANGE) {
dmz_dev_warn(dmz_dev, "Backing device offline");
dmz_dev->flags |= DMZ_BDEV_DYING;
}
return !(dmz_dev->flags & DMZ_BDEV_DYING);
}
/*
* Process a new BIO.
*/
static int dmz_map(struct dm_target *ti, struct bio *bio)
{
struct dmz_target *dmz = ti->private;
struct dmz_metadata *zmd = dmz->metadata;
struct dmz_bioctx *bioctx = dm_per_bio_data(bio, sizeof(struct dmz_bioctx));
sector_t sector = bio->bi_iter.bi_sector;
unsigned int nr_sectors = bio_sectors(bio);
sector_t chunk_sector;
int ret;
if (dmz_dev_is_dying(zmd))
return DM_MAPIO_KILL;
DMDEBUG("(%s): BIO op %d sector %llu + %u => chunk %llu, block %llu, %u blocks",
dmz_metadata_label(zmd),
bio_op(bio), (unsigned long long)sector, nr_sectors,
(unsigned long long)dmz_bio_chunk(zmd, bio),
(unsigned long long)dmz_chunk_block(zmd, dmz_bio_block(bio)),
(unsigned int)dmz_bio_blocks(bio));
if (!nr_sectors && bio_op(bio) != REQ_OP_WRITE)
return DM_MAPIO_REMAPPED;
/* The BIO should be block aligned */
if ((nr_sectors & DMZ_BLOCK_SECTORS_MASK) || (sector & DMZ_BLOCK_SECTORS_MASK))
return DM_MAPIO_KILL;
/* Initialize the BIO context */
bioctx->dev = NULL;
bioctx->zone = NULL;
bioctx->bio = bio;
refcount_set(&bioctx->ref, 1);
/* Set the BIO pending in the flush list */
if (!nr_sectors && bio_op(bio) == REQ_OP_WRITE) {
spin_lock(&dmz->flush_lock);
bio_list_add(&dmz->flush_list, bio);
spin_unlock(&dmz->flush_lock);
mod_delayed_work(dmz->flush_wq, &dmz->flush_work, 0);
return DM_MAPIO_SUBMITTED;
}
/* Split zone BIOs to fit entirely into a zone */
chunk_sector = sector & (dmz_zone_nr_sectors(zmd) - 1);
if (chunk_sector + nr_sectors > dmz_zone_nr_sectors(zmd))
dm_accept_partial_bio(bio, dmz_zone_nr_sectors(zmd) - chunk_sector);
/* Now ready to handle this BIO */
ret = dmz_queue_chunk_work(dmz, bio);
if (ret) {
DMDEBUG("(%s): BIO op %d, can't process chunk %llu, err %i",
dmz_metadata_label(zmd),
bio_op(bio), (u64)dmz_bio_chunk(zmd, bio),
ret);
return DM_MAPIO_REQUEUE;
}
return DM_MAPIO_SUBMITTED;
}
/*
* Get zoned device information.
*/
static int dmz_get_zoned_device(struct dm_target *ti, char *path,
int idx, int nr_devs)
{
struct dmz_target *dmz = ti->private;
struct dm_dev *ddev;
struct dmz_dev *dev;
int ret;
struct block_device *bdev;
/* Get the target device */
ret = dm_get_device(ti, path, dm_table_get_mode(ti->table), &ddev);
if (ret) {
ti->error = "Get target device failed";
return ret;
}
bdev = ddev->bdev;
if (bdev_zoned_model(bdev) == BLK_ZONED_NONE) {
if (nr_devs == 1) {
ti->error = "Invalid regular device";
goto err;
}
if (idx != 0) {
ti->error = "First device must be a regular device";
goto err;
}
if (dmz->ddev[0]) {
ti->error = "Too many regular devices";
goto err;
}
dev = &dmz->dev[idx];
dev->flags = DMZ_BDEV_REGULAR;
} else {
if (dmz->ddev[idx]) {
ti->error = "Too many zoned devices";
goto err;
}
if (nr_devs > 1 && idx == 0) {
ti->error = "First device must be a regular device";
goto err;
}
dev = &dmz->dev[idx];
}
dev->bdev = bdev;
dev->dev_idx = idx;
dev->capacity = bdev_nr_sectors(bdev);
if (ti->begin) {
ti->error = "Partial mapping is not supported";
goto err;
}
dmz->ddev[idx] = ddev;
return 0;
err:
dm_put_device(ti, ddev);
return -EINVAL;
}
/*
* Cleanup zoned device information.
*/
static void dmz_put_zoned_device(struct dm_target *ti)
{
struct dmz_target *dmz = ti->private;
int i;
for (i = 0; i < dmz->nr_ddevs; i++) {
if (dmz->ddev[i]) {
dm_put_device(ti, dmz->ddev[i]);
dmz->ddev[i] = NULL;
}
}
}
static int dmz_fixup_devices(struct dm_target *ti)
{
struct dmz_target *dmz = ti->private;
struct dmz_dev *reg_dev = NULL;
sector_t zone_nr_sectors = 0;
int i;
/*
* When we have more than on devices, the first one must be a
* regular block device and the others zoned block devices.
*/
if (dmz->nr_ddevs > 1) {
reg_dev = &dmz->dev[0];
if (!(reg_dev->flags & DMZ_BDEV_REGULAR)) {
ti->error = "Primary disk is not a regular device";
return -EINVAL;
}
for (i = 1; i < dmz->nr_ddevs; i++) {
struct dmz_dev *zoned_dev = &dmz->dev[i];
struct block_device *bdev = zoned_dev->bdev;
if (zoned_dev->flags & DMZ_BDEV_REGULAR) {
ti->error = "Secondary disk is not a zoned device";
return -EINVAL;
}
if (zone_nr_sectors &&
zone_nr_sectors != bdev_zone_sectors(bdev)) {
ti->error = "Zone nr sectors mismatch";
return -EINVAL;
}
zone_nr_sectors = bdev_zone_sectors(bdev);
zoned_dev->zone_nr_sectors = zone_nr_sectors;
zoned_dev->nr_zones = bdev_nr_zones(bdev);
}
} else {
struct dmz_dev *zoned_dev = &dmz->dev[0];
struct block_device *bdev = zoned_dev->bdev;
if (zoned_dev->flags & DMZ_BDEV_REGULAR) {
ti->error = "Disk is not a zoned device";
return -EINVAL;
}
zoned_dev->zone_nr_sectors = bdev_zone_sectors(bdev);
zoned_dev->nr_zones = bdev_nr_zones(bdev);
}
if (reg_dev) {
sector_t zone_offset;
reg_dev->zone_nr_sectors = zone_nr_sectors;
reg_dev->nr_zones =
DIV_ROUND_UP_SECTOR_T(reg_dev->capacity,
reg_dev->zone_nr_sectors);
reg_dev->zone_offset = 0;
zone_offset = reg_dev->nr_zones;
for (i = 1; i < dmz->nr_ddevs; i++) {
dmz->dev[i].zone_offset = zone_offset;
zone_offset += dmz->dev[i].nr_zones;
}
}
return 0;
}
/*
* Setup target.
*/
static int dmz_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
struct dmz_target *dmz;
int ret, i;
/* Check arguments */
if (argc < 1) {
ti->error = "Invalid argument count";
return -EINVAL;
}
/* Allocate and initialize the target descriptor */
dmz = kzalloc(sizeof(struct dmz_target), GFP_KERNEL);
if (!dmz) {
ti->error = "Unable to allocate the zoned target descriptor";
return -ENOMEM;
}
dmz->dev = kcalloc(argc, sizeof(struct dmz_dev), GFP_KERNEL);
if (!dmz->dev) {
ti->error = "Unable to allocate the zoned device descriptors";
kfree(dmz);
return -ENOMEM;
}
dmz->ddev = kcalloc(argc, sizeof(struct dm_dev *), GFP_KERNEL);
if (!dmz->ddev) {
ti->error = "Unable to allocate the dm device descriptors";
ret = -ENOMEM;
goto err;
}
dmz->nr_ddevs = argc;
ti->private = dmz;
/* Get the target zoned block device */
for (i = 0; i < argc; i++) {
ret = dmz_get_zoned_device(ti, argv[i], i, argc);
if (ret)
goto err_dev;
}
ret = dmz_fixup_devices(ti);
if (ret)
goto err_dev;
/* Initialize metadata */
ret = dmz_ctr_metadata(dmz->dev, argc, &dmz->metadata,
dm_table_device_name(ti->table));
if (ret) {
ti->error = "Metadata initialization failed";
goto err_dev;
}
/* Set target (no write same support) */
ti->max_io_len = dmz_zone_nr_sectors(dmz->metadata);
ti->num_flush_bios = 1;
ti->num_discard_bios = 1;
ti->num_write_zeroes_bios = 1;
ti->per_io_data_size = sizeof(struct dmz_bioctx);
ti->flush_supported = true;
ti->discards_supported = true;
/* The exposed capacity is the number of chunks that can be mapped */
ti->len = (sector_t)dmz_nr_chunks(dmz->metadata) <<
dmz_zone_nr_sectors_shift(dmz->metadata);
/* Zone BIO */
ret = bioset_init(&dmz->bio_set, DMZ_MIN_BIOS, 0, 0);
if (ret) {
ti->error = "Create BIO set failed";
goto err_meta;
}
/* Chunk BIO work */
mutex_init(&dmz->chunk_lock);
INIT_RADIX_TREE(&dmz->chunk_rxtree, GFP_NOIO);
dmz->chunk_wq = alloc_workqueue("dmz_cwq_%s",
WQ_MEM_RECLAIM | WQ_UNBOUND, 0,
dmz_metadata_label(dmz->metadata));
if (!dmz->chunk_wq) {
ti->error = "Create chunk workqueue failed";
ret = -ENOMEM;
goto err_bio;
}
/* Flush work */
spin_lock_init(&dmz->flush_lock);
bio_list_init(&dmz->flush_list);
INIT_DELAYED_WORK(&dmz->flush_work, dmz_flush_work);
dmz->flush_wq = alloc_ordered_workqueue("dmz_fwq_%s", WQ_MEM_RECLAIM,
dmz_metadata_label(dmz->metadata));
if (!dmz->flush_wq) {
ti->error = "Create flush workqueue failed";
ret = -ENOMEM;
goto err_cwq;
}
mod_delayed_work(dmz->flush_wq, &dmz->flush_work, DMZ_FLUSH_PERIOD);
/* Initialize reclaim */
for (i = 0; i < dmz->nr_ddevs; i++) {
ret = dmz_ctr_reclaim(dmz->metadata, &dmz->dev[i].reclaim, i);
if (ret) {
ti->error = "Zone reclaim initialization failed";
goto err_fwq;
}
}
DMINFO("(%s): Target device: %llu 512-byte logical sectors (%llu blocks)",
dmz_metadata_label(dmz->metadata),
(unsigned long long)ti->len,
(unsigned long long)dmz_sect2blk(ti->len));
return 0;
err_fwq:
destroy_workqueue(dmz->flush_wq);
err_cwq:
destroy_workqueue(dmz->chunk_wq);
err_bio:
mutex_destroy(&dmz->chunk_lock);
bioset_exit(&dmz->bio_set);
err_meta:
dmz_dtr_metadata(dmz->metadata);
err_dev:
dmz_put_zoned_device(ti);
err:
kfree(dmz->dev);
kfree(dmz);
return ret;
}
/*
* Cleanup target.
*/
static void dmz_dtr(struct dm_target *ti)
{
struct dmz_target *dmz = ti->private;
int i;
destroy_workqueue(dmz->chunk_wq);
for (i = 0; i < dmz->nr_ddevs; i++)
dmz_dtr_reclaim(dmz->dev[i].reclaim);
cancel_delayed_work_sync(&dmz->flush_work);
destroy_workqueue(dmz->flush_wq);
(void) dmz_flush_metadata(dmz->metadata);
dmz_dtr_metadata(dmz->metadata);
bioset_exit(&dmz->bio_set);
dmz_put_zoned_device(ti);
mutex_destroy(&dmz->chunk_lock);
kfree(dmz->dev);
kfree(dmz);
}
/*
* Setup target request queue limits.
*/
static void dmz_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
struct dmz_target *dmz = ti->private;
unsigned int chunk_sectors = dmz_zone_nr_sectors(dmz->metadata);
limits->logical_block_size = DMZ_BLOCK_SIZE;
limits->physical_block_size = DMZ_BLOCK_SIZE;
blk_limits_io_min(limits, DMZ_BLOCK_SIZE);
blk_limits_io_opt(limits, DMZ_BLOCK_SIZE);
limits->discard_alignment = 0;
limits->discard_granularity = DMZ_BLOCK_SIZE;
limits->max_discard_sectors = chunk_sectors;
limits->max_hw_discard_sectors = chunk_sectors;
limits->max_write_zeroes_sectors = chunk_sectors;
/* FS hint to try to align to the device zone size */
limits->chunk_sectors = chunk_sectors;
limits->max_sectors = chunk_sectors;
/* We are exposing a drive-managed zoned block device */
limits->zoned = BLK_ZONED_NONE;
}
/*
* Pass on ioctl to the backend device.
*/
static int dmz_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
{
struct dmz_target *dmz = ti->private;
struct dmz_dev *dev = &dmz->dev[0];
if (!dmz_check_bdev(dev))
return -EIO;
*bdev = dev->bdev;
return 0;
}
/*
* Stop works on suspend.
*/
static void dmz_suspend(struct dm_target *ti)
{
struct dmz_target *dmz = ti->private;
int i;
flush_workqueue(dmz->chunk_wq);
for (i = 0; i < dmz->nr_ddevs; i++)
dmz_suspend_reclaim(dmz->dev[i].reclaim);
cancel_delayed_work_sync(&dmz->flush_work);
}
/*
* Restart works on resume or if suspend failed.
*/
static void dmz_resume(struct dm_target *ti)
{
struct dmz_target *dmz = ti->private;
int i;
queue_delayed_work(dmz->flush_wq, &dmz->flush_work, DMZ_FLUSH_PERIOD);
for (i = 0; i < dmz->nr_ddevs; i++)
dmz_resume_reclaim(dmz->dev[i].reclaim);
}
static int dmz_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct dmz_target *dmz = ti->private;
unsigned int zone_nr_sectors = dmz_zone_nr_sectors(dmz->metadata);
sector_t capacity;
int i, r;
for (i = 0; i < dmz->nr_ddevs; i++) {
capacity = dmz->dev[i].capacity & ~(zone_nr_sectors - 1);
r = fn(ti, dmz->ddev[i], 0, capacity, data);
if (r)
break;
}
return r;
}
static void dmz_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result,
unsigned int maxlen)
{
struct dmz_target *dmz = ti->private;
ssize_t sz = 0;
char buf[BDEVNAME_SIZE];
struct dmz_dev *dev;
int i;
switch (type) {
case STATUSTYPE_INFO:
DMEMIT("%u zones %u/%u cache",
dmz_nr_zones(dmz->metadata),
dmz_nr_unmap_cache_zones(dmz->metadata),
dmz_nr_cache_zones(dmz->metadata));
for (i = 0; i < dmz->nr_ddevs; i++) {
/*
* For a multi-device setup the first device
* contains only cache zones.
*/
if ((i == 0) &&
(dmz_nr_cache_zones(dmz->metadata) > 0))
continue;
DMEMIT(" %u/%u random %u/%u sequential",
dmz_nr_unmap_rnd_zones(dmz->metadata, i),
dmz_nr_rnd_zones(dmz->metadata, i),
dmz_nr_unmap_seq_zones(dmz->metadata, i),
dmz_nr_seq_zones(dmz->metadata, i));
}
break;
case STATUSTYPE_TABLE:
dev = &dmz->dev[0];
format_dev_t(buf, dev->bdev->bd_dev);
DMEMIT("%s", buf);
for (i = 1; i < dmz->nr_ddevs; i++) {
dev = &dmz->dev[i];
format_dev_t(buf, dev->bdev->bd_dev);
DMEMIT(" %s", buf);
}
break;
case STATUSTYPE_IMA:
*result = '\0';
break;
}
}
static int dmz_message(struct dm_target *ti, unsigned int argc, char **argv,
char *result, unsigned int maxlen)
{
struct dmz_target *dmz = ti->private;
int r = -EINVAL;
if (!strcasecmp(argv[0], "reclaim")) {
int i;
for (i = 0; i < dmz->nr_ddevs; i++)
dmz_schedule_reclaim(dmz->dev[i].reclaim);
r = 0;
} else
DMERR("unrecognized message %s", argv[0]);
return r;
}
static struct target_type zoned_target = {
.name = "zoned",
.version = {2, 0, 0},
.features = DM_TARGET_SINGLETON | DM_TARGET_MIXED_ZONED_MODEL,
.module = THIS_MODULE,
.ctr = dmz_ctr,
.dtr = dmz_dtr,
.map = dmz_map,
.io_hints = dmz_io_hints,
.prepare_ioctl = dmz_prepare_ioctl,
.postsuspend = dmz_suspend,
.resume = dmz_resume,
.iterate_devices = dmz_iterate_devices,
.status = dmz_status,
.message = dmz_message,
};
module_dm(zoned);
MODULE_DESCRIPTION(DM_NAME " target for zoned block devices");
MODULE_AUTHOR("Damien Le Moal <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-zoned-target.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2015 Shaohua Li <[email protected]>
* Copyright (C) 2016 Song Liu <[email protected]>
*/
#include <linux/kernel.h>
#include <linux/wait.h>
#include <linux/blkdev.h>
#include <linux/slab.h>
#include <linux/raid/md_p.h>
#include <linux/crc32c.h>
#include <linux/random.h>
#include <linux/kthread.h>
#include <linux/types.h>
#include "md.h"
#include "raid5.h"
#include "md-bitmap.h"
#include "raid5-log.h"
/*
* metadata/data stored in disk with 4k size unit (a block) regardless
* underneath hardware sector size. only works with PAGE_SIZE == 4096
*/
#define BLOCK_SECTORS (8)
#define BLOCK_SECTOR_SHIFT (3)
/*
* log->max_free_space is min(1/4 disk size, 10G reclaimable space).
*
* In write through mode, the reclaim runs every log->max_free_space.
* This can prevent the recovery scans for too long
*/
#define RECLAIM_MAX_FREE_SPACE (10 * 1024 * 1024 * 2) /* sector */
#define RECLAIM_MAX_FREE_SPACE_SHIFT (2)
/* wake up reclaim thread periodically */
#define R5C_RECLAIM_WAKEUP_INTERVAL (30 * HZ)
/* start flush with these full stripes */
#define R5C_FULL_STRIPE_FLUSH_BATCH(conf) (conf->max_nr_stripes / 4)
/* reclaim stripes in groups */
#define R5C_RECLAIM_STRIPE_GROUP (NR_STRIPE_HASH_LOCKS * 2)
/*
* We only need 2 bios per I/O unit to make progress, but ensure we
* have a few more available to not get too tight.
*/
#define R5L_POOL_SIZE 4
static char *r5c_journal_mode_str[] = {"write-through",
"write-back"};
/*
* raid5 cache state machine
*
* With the RAID cache, each stripe works in two phases:
* - caching phase
* - writing-out phase
*
* These two phases are controlled by bit STRIPE_R5C_CACHING:
* if STRIPE_R5C_CACHING == 0, the stripe is in writing-out phase
* if STRIPE_R5C_CACHING == 1, the stripe is in caching phase
*
* When there is no journal, or the journal is in write-through mode,
* the stripe is always in writing-out phase.
*
* For write-back journal, the stripe is sent to caching phase on write
* (r5c_try_caching_write). r5c_make_stripe_write_out() kicks off
* the write-out phase by clearing STRIPE_R5C_CACHING.
*
* Stripes in caching phase do not write the raid disks. Instead, all
* writes are committed from the log device. Therefore, a stripe in
* caching phase handles writes as:
* - write to log device
* - return IO
*
* Stripes in writing-out phase handle writes as:
* - calculate parity
* - write pending data and parity to journal
* - write data and parity to raid disks
* - return IO for pending writes
*/
struct r5l_log {
struct md_rdev *rdev;
u32 uuid_checksum;
sector_t device_size; /* log device size, round to
* BLOCK_SECTORS */
sector_t max_free_space; /* reclaim run if free space is at
* this size */
sector_t last_checkpoint; /* log tail. where recovery scan
* starts from */
u64 last_cp_seq; /* log tail sequence */
sector_t log_start; /* log head. where new data appends */
u64 seq; /* log head sequence */
sector_t next_checkpoint;
struct mutex io_mutex;
struct r5l_io_unit *current_io; /* current io_unit accepting new data */
spinlock_t io_list_lock;
struct list_head running_ios; /* io_units which are still running,
* and have not yet been completely
* written to the log */
struct list_head io_end_ios; /* io_units which have been completely
* written to the log but not yet written
* to the RAID */
struct list_head flushing_ios; /* io_units which are waiting for log
* cache flush */
struct list_head finished_ios; /* io_units which settle down in log disk */
struct bio flush_bio;
struct list_head no_mem_stripes; /* pending stripes, -ENOMEM */
struct kmem_cache *io_kc;
mempool_t io_pool;
struct bio_set bs;
mempool_t meta_pool;
struct md_thread __rcu *reclaim_thread;
unsigned long reclaim_target; /* number of space that need to be
* reclaimed. if it's 0, reclaim spaces
* used by io_units which are in
* IO_UNIT_STRIPE_END state (eg, reclaim
* doesn't wait for specific io_unit
* switching to IO_UNIT_STRIPE_END
* state) */
wait_queue_head_t iounit_wait;
struct list_head no_space_stripes; /* pending stripes, log has no space */
spinlock_t no_space_stripes_lock;
bool need_cache_flush;
/* for r5c_cache */
enum r5c_journal_mode r5c_journal_mode;
/* all stripes in r5cache, in the order of seq at sh->log_start */
struct list_head stripe_in_journal_list;
spinlock_t stripe_in_journal_lock;
atomic_t stripe_in_journal_count;
/* to submit async io_units, to fulfill ordering of flush */
struct work_struct deferred_io_work;
/* to disable write back during in degraded mode */
struct work_struct disable_writeback_work;
/* to for chunk_aligned_read in writeback mode, details below */
spinlock_t tree_lock;
struct radix_tree_root big_stripe_tree;
};
/*
* Enable chunk_aligned_read() with write back cache.
*
* Each chunk may contain more than one stripe (for example, a 256kB
* chunk contains 64 4kB-page, so this chunk contain 64 stripes). For
* chunk_aligned_read, these stripes are grouped into one "big_stripe".
* For each big_stripe, we count how many stripes of this big_stripe
* are in the write back cache. These data are tracked in a radix tree
* (big_stripe_tree). We use radix_tree item pointer as the counter.
* r5c_tree_index() is used to calculate keys for the radix tree.
*
* chunk_aligned_read() calls r5c_big_stripe_cached() to look up
* big_stripe of each chunk in the tree. If this big_stripe is in the
* tree, chunk_aligned_read() aborts. This look up is protected by
* rcu_read_lock().
*
* It is necessary to remember whether a stripe is counted in
* big_stripe_tree. Instead of adding new flag, we reuses existing flags:
* STRIPE_R5C_PARTIAL_STRIPE and STRIPE_R5C_FULL_STRIPE. If either of these
* two flags are set, the stripe is counted in big_stripe_tree. This
* requires moving set_bit(STRIPE_R5C_PARTIAL_STRIPE) to
* r5c_try_caching_write(); and moving clear_bit of
* STRIPE_R5C_PARTIAL_STRIPE and STRIPE_R5C_FULL_STRIPE to
* r5c_finish_stripe_write_out().
*/
/*
* radix tree requests lowest 2 bits of data pointer to be 2b'00.
* So it is necessary to left shift the counter by 2 bits before using it
* as data pointer of the tree.
*/
#define R5C_RADIX_COUNT_SHIFT 2
/*
* calculate key for big_stripe_tree
*
* sect: align_bi->bi_iter.bi_sector or sh->sector
*/
static inline sector_t r5c_tree_index(struct r5conf *conf,
sector_t sect)
{
sector_div(sect, conf->chunk_sectors);
return sect;
}
/*
* an IO range starts from a meta data block and end at the next meta data
* block. The io unit's the meta data block tracks data/parity followed it. io
* unit is written to log disk with normal write, as we always flush log disk
* first and then start move data to raid disks, there is no requirement to
* write io unit with FLUSH/FUA
*/
struct r5l_io_unit {
struct r5l_log *log;
struct page *meta_page; /* store meta block */
int meta_offset; /* current offset in meta_page */
struct bio *current_bio;/* current_bio accepting new data */
atomic_t pending_stripe;/* how many stripes not flushed to raid */
u64 seq; /* seq number of the metablock */
sector_t log_start; /* where the io_unit starts */
sector_t log_end; /* where the io_unit ends */
struct list_head log_sibling; /* log->running_ios */
struct list_head stripe_list; /* stripes added to the io_unit */
int state;
bool need_split_bio;
struct bio *split_bio;
unsigned int has_flush:1; /* include flush request */
unsigned int has_fua:1; /* include fua request */
unsigned int has_null_flush:1; /* include null flush request */
unsigned int has_flush_payload:1; /* include flush payload */
/*
* io isn't sent yet, flush/fua request can only be submitted till it's
* the first IO in running_ios list
*/
unsigned int io_deferred:1;
struct bio_list flush_barriers; /* size == 0 flush bios */
};
/* r5l_io_unit state */
enum r5l_io_unit_state {
IO_UNIT_RUNNING = 0, /* accepting new IO */
IO_UNIT_IO_START = 1, /* io_unit bio start writing to log,
* don't accepting new bio */
IO_UNIT_IO_END = 2, /* io_unit bio finish writing to log */
IO_UNIT_STRIPE_END = 3, /* stripes data finished writing to raid */
};
bool r5c_is_writeback(struct r5l_log *log)
{
return (log != NULL &&
log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK);
}
static sector_t r5l_ring_add(struct r5l_log *log, sector_t start, sector_t inc)
{
start += inc;
if (start >= log->device_size)
start = start - log->device_size;
return start;
}
static sector_t r5l_ring_distance(struct r5l_log *log, sector_t start,
sector_t end)
{
if (end >= start)
return end - start;
else
return end + log->device_size - start;
}
static bool r5l_has_free_space(struct r5l_log *log, sector_t size)
{
sector_t used_size;
used_size = r5l_ring_distance(log, log->last_checkpoint,
log->log_start);
return log->device_size > used_size + size;
}
static void __r5l_set_io_unit_state(struct r5l_io_unit *io,
enum r5l_io_unit_state state)
{
if (WARN_ON(io->state >= state))
return;
io->state = state;
}
static void
r5c_return_dev_pending_writes(struct r5conf *conf, struct r5dev *dev)
{
struct bio *wbi, *wbi2;
wbi = dev->written;
dev->written = NULL;
while (wbi && wbi->bi_iter.bi_sector <
dev->sector + RAID5_STRIPE_SECTORS(conf)) {
wbi2 = r5_next_bio(conf, wbi, dev->sector);
md_write_end(conf->mddev);
bio_endio(wbi);
wbi = wbi2;
}
}
void r5c_handle_cached_data_endio(struct r5conf *conf,
struct stripe_head *sh, int disks)
{
int i;
for (i = sh->disks; i--; ) {
if (sh->dev[i].written) {
set_bit(R5_UPTODATE, &sh->dev[i].flags);
r5c_return_dev_pending_writes(conf, &sh->dev[i]);
md_bitmap_endwrite(conf->mddev->bitmap, sh->sector,
RAID5_STRIPE_SECTORS(conf),
!test_bit(STRIPE_DEGRADED, &sh->state),
0);
}
}
}
void r5l_wake_reclaim(struct r5l_log *log, sector_t space);
/* Check whether we should flush some stripes to free up stripe cache */
void r5c_check_stripe_cache_usage(struct r5conf *conf)
{
int total_cached;
if (!r5c_is_writeback(conf->log))
return;
total_cached = atomic_read(&conf->r5c_cached_partial_stripes) +
atomic_read(&conf->r5c_cached_full_stripes);
/*
* The following condition is true for either of the following:
* - stripe cache pressure high:
* total_cached > 3/4 min_nr_stripes ||
* empty_inactive_list_nr > 0
* - stripe cache pressure moderate:
* total_cached > 1/2 min_nr_stripes
*/
if (total_cached > conf->min_nr_stripes * 1 / 2 ||
atomic_read(&conf->empty_inactive_list_nr) > 0)
r5l_wake_reclaim(conf->log, 0);
}
/*
* flush cache when there are R5C_FULL_STRIPE_FLUSH_BATCH or more full
* stripes in the cache
*/
void r5c_check_cached_full_stripe(struct r5conf *conf)
{
if (!r5c_is_writeback(conf->log))
return;
/*
* wake up reclaim for R5C_FULL_STRIPE_FLUSH_BATCH cached stripes
* or a full stripe (chunk size / 4k stripes).
*/
if (atomic_read(&conf->r5c_cached_full_stripes) >=
min(R5C_FULL_STRIPE_FLUSH_BATCH(conf),
conf->chunk_sectors >> RAID5_STRIPE_SHIFT(conf)))
r5l_wake_reclaim(conf->log, 0);
}
/*
* Total log space (in sectors) needed to flush all data in cache
*
* To avoid deadlock due to log space, it is necessary to reserve log
* space to flush critical stripes (stripes that occupying log space near
* last_checkpoint). This function helps check how much log space is
* required to flush all cached stripes.
*
* To reduce log space requirements, two mechanisms are used to give cache
* flush higher priorities:
* 1. In handle_stripe_dirtying() and schedule_reconstruction(),
* stripes ALREADY in journal can be flushed w/o pending writes;
* 2. In r5l_write_stripe() and r5c_cache_data(), stripes NOT in journal
* can be delayed (r5l_add_no_space_stripe).
*
* In cache flush, the stripe goes through 1 and then 2. For a stripe that
* already passed 1, flushing it requires at most (conf->max_degraded + 1)
* pages of journal space. For stripes that has not passed 1, flushing it
* requires (conf->raid_disks + 1) pages of journal space. There are at
* most (conf->group_cnt + 1) stripe that passed 1. So total journal space
* required to flush all cached stripes (in pages) is:
*
* (stripe_in_journal_count - group_cnt - 1) * (max_degraded + 1) +
* (group_cnt + 1) * (raid_disks + 1)
* or
* (stripe_in_journal_count) * (max_degraded + 1) +
* (group_cnt + 1) * (raid_disks - max_degraded)
*/
static sector_t r5c_log_required_to_flush_cache(struct r5conf *conf)
{
struct r5l_log *log = conf->log;
if (!r5c_is_writeback(log))
return 0;
return BLOCK_SECTORS *
((conf->max_degraded + 1) * atomic_read(&log->stripe_in_journal_count) +
(conf->raid_disks - conf->max_degraded) * (conf->group_cnt + 1));
}
/*
* evaluate log space usage and update R5C_LOG_TIGHT and R5C_LOG_CRITICAL
*
* R5C_LOG_TIGHT is set when free space on the log device is less than 3x of
* reclaim_required_space. R5C_LOG_CRITICAL is set when free space on the log
* device is less than 2x of reclaim_required_space.
*/
static inline void r5c_update_log_state(struct r5l_log *log)
{
struct r5conf *conf = log->rdev->mddev->private;
sector_t free_space;
sector_t reclaim_space;
bool wake_reclaim = false;
if (!r5c_is_writeback(log))
return;
free_space = r5l_ring_distance(log, log->log_start,
log->last_checkpoint);
reclaim_space = r5c_log_required_to_flush_cache(conf);
if (free_space < 2 * reclaim_space)
set_bit(R5C_LOG_CRITICAL, &conf->cache_state);
else {
if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state))
wake_reclaim = true;
clear_bit(R5C_LOG_CRITICAL, &conf->cache_state);
}
if (free_space < 3 * reclaim_space)
set_bit(R5C_LOG_TIGHT, &conf->cache_state);
else
clear_bit(R5C_LOG_TIGHT, &conf->cache_state);
if (wake_reclaim)
r5l_wake_reclaim(log, 0);
}
/*
* Put the stripe into writing-out phase by clearing STRIPE_R5C_CACHING.
* This function should only be called in write-back mode.
*/
void r5c_make_stripe_write_out(struct stripe_head *sh)
{
struct r5conf *conf = sh->raid_conf;
struct r5l_log *log = conf->log;
BUG_ON(!r5c_is_writeback(log));
WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
clear_bit(STRIPE_R5C_CACHING, &sh->state);
if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
atomic_inc(&conf->preread_active_stripes);
}
static void r5c_handle_data_cached(struct stripe_head *sh)
{
int i;
for (i = sh->disks; i--; )
if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
set_bit(R5_InJournal, &sh->dev[i].flags);
clear_bit(R5_LOCKED, &sh->dev[i].flags);
}
clear_bit(STRIPE_LOG_TRAPPED, &sh->state);
}
/*
* this journal write must contain full parity,
* it may also contain some data pages
*/
static void r5c_handle_parity_cached(struct stripe_head *sh)
{
int i;
for (i = sh->disks; i--; )
if (test_bit(R5_InJournal, &sh->dev[i].flags))
set_bit(R5_Wantwrite, &sh->dev[i].flags);
}
/*
* Setting proper flags after writing (or flushing) data and/or parity to the
* log device. This is called from r5l_log_endio() or r5l_log_flush_endio().
*/
static void r5c_finish_cache_stripe(struct stripe_head *sh)
{
struct r5l_log *log = sh->raid_conf->log;
if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
BUG_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
/*
* Set R5_InJournal for parity dev[pd_idx]. This means
* all data AND parity in the journal. For RAID 6, it is
* NOT necessary to set the flag for dev[qd_idx], as the
* two parities are written out together.
*/
set_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
} else if (test_bit(STRIPE_R5C_CACHING, &sh->state)) {
r5c_handle_data_cached(sh);
} else {
r5c_handle_parity_cached(sh);
set_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
}
}
static void r5l_io_run_stripes(struct r5l_io_unit *io)
{
struct stripe_head *sh, *next;
list_for_each_entry_safe(sh, next, &io->stripe_list, log_list) {
list_del_init(&sh->log_list);
r5c_finish_cache_stripe(sh);
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
}
}
static void r5l_log_run_stripes(struct r5l_log *log)
{
struct r5l_io_unit *io, *next;
lockdep_assert_held(&log->io_list_lock);
list_for_each_entry_safe(io, next, &log->running_ios, log_sibling) {
/* don't change list order */
if (io->state < IO_UNIT_IO_END)
break;
list_move_tail(&io->log_sibling, &log->finished_ios);
r5l_io_run_stripes(io);
}
}
static void r5l_move_to_end_ios(struct r5l_log *log)
{
struct r5l_io_unit *io, *next;
lockdep_assert_held(&log->io_list_lock);
list_for_each_entry_safe(io, next, &log->running_ios, log_sibling) {
/* don't change list order */
if (io->state < IO_UNIT_IO_END)
break;
list_move_tail(&io->log_sibling, &log->io_end_ios);
}
}
static void __r5l_stripe_write_finished(struct r5l_io_unit *io);
static void r5l_log_endio(struct bio *bio)
{
struct r5l_io_unit *io = bio->bi_private;
struct r5l_io_unit *io_deferred;
struct r5l_log *log = io->log;
unsigned long flags;
bool has_null_flush;
bool has_flush_payload;
if (bio->bi_status)
md_error(log->rdev->mddev, log->rdev);
bio_put(bio);
mempool_free(io->meta_page, &log->meta_pool);
spin_lock_irqsave(&log->io_list_lock, flags);
__r5l_set_io_unit_state(io, IO_UNIT_IO_END);
/*
* if the io doesn't not have null_flush or flush payload,
* it is not safe to access it after releasing io_list_lock.
* Therefore, it is necessary to check the condition with
* the lock held.
*/
has_null_flush = io->has_null_flush;
has_flush_payload = io->has_flush_payload;
if (log->need_cache_flush && !list_empty(&io->stripe_list))
r5l_move_to_end_ios(log);
else
r5l_log_run_stripes(log);
if (!list_empty(&log->running_ios)) {
/*
* FLUSH/FUA io_unit is deferred because of ordering, now we
* can dispatch it
*/
io_deferred = list_first_entry(&log->running_ios,
struct r5l_io_unit, log_sibling);
if (io_deferred->io_deferred)
schedule_work(&log->deferred_io_work);
}
spin_unlock_irqrestore(&log->io_list_lock, flags);
if (log->need_cache_flush)
md_wakeup_thread(log->rdev->mddev->thread);
/* finish flush only io_unit and PAYLOAD_FLUSH only io_unit */
if (has_null_flush) {
struct bio *bi;
WARN_ON(bio_list_empty(&io->flush_barriers));
while ((bi = bio_list_pop(&io->flush_barriers)) != NULL) {
bio_endio(bi);
if (atomic_dec_and_test(&io->pending_stripe)) {
__r5l_stripe_write_finished(io);
return;
}
}
}
/* decrease pending_stripe for flush payload */
if (has_flush_payload)
if (atomic_dec_and_test(&io->pending_stripe))
__r5l_stripe_write_finished(io);
}
static void r5l_do_submit_io(struct r5l_log *log, struct r5l_io_unit *io)
{
unsigned long flags;
spin_lock_irqsave(&log->io_list_lock, flags);
__r5l_set_io_unit_state(io, IO_UNIT_IO_START);
spin_unlock_irqrestore(&log->io_list_lock, flags);
/*
* In case of journal device failures, submit_bio will get error
* and calls endio, then active stripes will continue write
* process. Therefore, it is not necessary to check Faulty bit
* of journal device here.
*
* We can't check split_bio after current_bio is submitted. If
* io->split_bio is null, after current_bio is submitted, current_bio
* might already be completed and the io_unit is freed. We submit
* split_bio first to avoid the issue.
*/
if (io->split_bio) {
if (io->has_flush)
io->split_bio->bi_opf |= REQ_PREFLUSH;
if (io->has_fua)
io->split_bio->bi_opf |= REQ_FUA;
submit_bio(io->split_bio);
}
if (io->has_flush)
io->current_bio->bi_opf |= REQ_PREFLUSH;
if (io->has_fua)
io->current_bio->bi_opf |= REQ_FUA;
submit_bio(io->current_bio);
}
/* deferred io_unit will be dispatched here */
static void r5l_submit_io_async(struct work_struct *work)
{
struct r5l_log *log = container_of(work, struct r5l_log,
deferred_io_work);
struct r5l_io_unit *io = NULL;
unsigned long flags;
spin_lock_irqsave(&log->io_list_lock, flags);
if (!list_empty(&log->running_ios)) {
io = list_first_entry(&log->running_ios, struct r5l_io_unit,
log_sibling);
if (!io->io_deferred)
io = NULL;
else
io->io_deferred = 0;
}
spin_unlock_irqrestore(&log->io_list_lock, flags);
if (io)
r5l_do_submit_io(log, io);
}
static void r5c_disable_writeback_async(struct work_struct *work)
{
struct r5l_log *log = container_of(work, struct r5l_log,
disable_writeback_work);
struct mddev *mddev = log->rdev->mddev;
struct r5conf *conf = mddev->private;
int locked = 0;
if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
return;
pr_info("md/raid:%s: Disabling writeback cache for degraded array.\n",
mdname(mddev));
/* wait superblock change before suspend */
wait_event(mddev->sb_wait,
conf->log == NULL ||
(!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags) &&
(locked = mddev_trylock(mddev))));
if (locked) {
mddev_suspend(mddev);
log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
mddev_resume(mddev);
mddev_unlock(mddev);
}
}
static void r5l_submit_current_io(struct r5l_log *log)
{
struct r5l_io_unit *io = log->current_io;
struct r5l_meta_block *block;
unsigned long flags;
u32 crc;
bool do_submit = true;
if (!io)
return;
block = page_address(io->meta_page);
block->meta_size = cpu_to_le32(io->meta_offset);
crc = crc32c_le(log->uuid_checksum, block, PAGE_SIZE);
block->checksum = cpu_to_le32(crc);
log->current_io = NULL;
spin_lock_irqsave(&log->io_list_lock, flags);
if (io->has_flush || io->has_fua) {
if (io != list_first_entry(&log->running_ios,
struct r5l_io_unit, log_sibling)) {
io->io_deferred = 1;
do_submit = false;
}
}
spin_unlock_irqrestore(&log->io_list_lock, flags);
if (do_submit)
r5l_do_submit_io(log, io);
}
static struct bio *r5l_bio_alloc(struct r5l_log *log)
{
struct bio *bio = bio_alloc_bioset(log->rdev->bdev, BIO_MAX_VECS,
REQ_OP_WRITE, GFP_NOIO, &log->bs);
bio->bi_iter.bi_sector = log->rdev->data_offset + log->log_start;
return bio;
}
static void r5_reserve_log_entry(struct r5l_log *log, struct r5l_io_unit *io)
{
log->log_start = r5l_ring_add(log, log->log_start, BLOCK_SECTORS);
r5c_update_log_state(log);
/*
* If we filled up the log device start from the beginning again,
* which will require a new bio.
*
* Note: for this to work properly the log size needs to me a multiple
* of BLOCK_SECTORS.
*/
if (log->log_start == 0)
io->need_split_bio = true;
io->log_end = log->log_start;
}
static struct r5l_io_unit *r5l_new_meta(struct r5l_log *log)
{
struct r5l_io_unit *io;
struct r5l_meta_block *block;
io = mempool_alloc(&log->io_pool, GFP_ATOMIC);
if (!io)
return NULL;
memset(io, 0, sizeof(*io));
io->log = log;
INIT_LIST_HEAD(&io->log_sibling);
INIT_LIST_HEAD(&io->stripe_list);
bio_list_init(&io->flush_barriers);
io->state = IO_UNIT_RUNNING;
io->meta_page = mempool_alloc(&log->meta_pool, GFP_NOIO);
block = page_address(io->meta_page);
clear_page(block);
block->magic = cpu_to_le32(R5LOG_MAGIC);
block->version = R5LOG_VERSION;
block->seq = cpu_to_le64(log->seq);
block->position = cpu_to_le64(log->log_start);
io->log_start = log->log_start;
io->meta_offset = sizeof(struct r5l_meta_block);
io->seq = log->seq++;
io->current_bio = r5l_bio_alloc(log);
io->current_bio->bi_end_io = r5l_log_endio;
io->current_bio->bi_private = io;
__bio_add_page(io->current_bio, io->meta_page, PAGE_SIZE, 0);
r5_reserve_log_entry(log, io);
spin_lock_irq(&log->io_list_lock);
list_add_tail(&io->log_sibling, &log->running_ios);
spin_unlock_irq(&log->io_list_lock);
return io;
}
static int r5l_get_meta(struct r5l_log *log, unsigned int payload_size)
{
if (log->current_io &&
log->current_io->meta_offset + payload_size > PAGE_SIZE)
r5l_submit_current_io(log);
if (!log->current_io) {
log->current_io = r5l_new_meta(log);
if (!log->current_io)
return -ENOMEM;
}
return 0;
}
static void r5l_append_payload_meta(struct r5l_log *log, u16 type,
sector_t location,
u32 checksum1, u32 checksum2,
bool checksum2_valid)
{
struct r5l_io_unit *io = log->current_io;
struct r5l_payload_data_parity *payload;
payload = page_address(io->meta_page) + io->meta_offset;
payload->header.type = cpu_to_le16(type);
payload->header.flags = cpu_to_le16(0);
payload->size = cpu_to_le32((1 + !!checksum2_valid) <<
(PAGE_SHIFT - 9));
payload->location = cpu_to_le64(location);
payload->checksum[0] = cpu_to_le32(checksum1);
if (checksum2_valid)
payload->checksum[1] = cpu_to_le32(checksum2);
io->meta_offset += sizeof(struct r5l_payload_data_parity) +
sizeof(__le32) * (1 + !!checksum2_valid);
}
static void r5l_append_payload_page(struct r5l_log *log, struct page *page)
{
struct r5l_io_unit *io = log->current_io;
if (io->need_split_bio) {
BUG_ON(io->split_bio);
io->split_bio = io->current_bio;
io->current_bio = r5l_bio_alloc(log);
bio_chain(io->current_bio, io->split_bio);
io->need_split_bio = false;
}
if (!bio_add_page(io->current_bio, page, PAGE_SIZE, 0))
BUG();
r5_reserve_log_entry(log, io);
}
static void r5l_append_flush_payload(struct r5l_log *log, sector_t sect)
{
struct mddev *mddev = log->rdev->mddev;
struct r5conf *conf = mddev->private;
struct r5l_io_unit *io;
struct r5l_payload_flush *payload;
int meta_size;
/*
* payload_flush requires extra writes to the journal.
* To avoid handling the extra IO in quiesce, just skip
* flush_payload
*/
if (conf->quiesce)
return;
mutex_lock(&log->io_mutex);
meta_size = sizeof(struct r5l_payload_flush) + sizeof(__le64);
if (r5l_get_meta(log, meta_size)) {
mutex_unlock(&log->io_mutex);
return;
}
/* current implementation is one stripe per flush payload */
io = log->current_io;
payload = page_address(io->meta_page) + io->meta_offset;
payload->header.type = cpu_to_le16(R5LOG_PAYLOAD_FLUSH);
payload->header.flags = cpu_to_le16(0);
payload->size = cpu_to_le32(sizeof(__le64));
payload->flush_stripes[0] = cpu_to_le64(sect);
io->meta_offset += meta_size;
/* multiple flush payloads count as one pending_stripe */
if (!io->has_flush_payload) {
io->has_flush_payload = 1;
atomic_inc(&io->pending_stripe);
}
mutex_unlock(&log->io_mutex);
}
static int r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
int data_pages, int parity_pages)
{
int i;
int meta_size;
int ret;
struct r5l_io_unit *io;
meta_size =
((sizeof(struct r5l_payload_data_parity) + sizeof(__le32))
* data_pages) +
sizeof(struct r5l_payload_data_parity) +
sizeof(__le32) * parity_pages;
ret = r5l_get_meta(log, meta_size);
if (ret)
return ret;
io = log->current_io;
if (test_and_clear_bit(STRIPE_R5C_PREFLUSH, &sh->state))
io->has_flush = 1;
for (i = 0; i < sh->disks; i++) {
if (!test_bit(R5_Wantwrite, &sh->dev[i].flags) ||
test_bit(R5_InJournal, &sh->dev[i].flags))
continue;
if (i == sh->pd_idx || i == sh->qd_idx)
continue;
if (test_bit(R5_WantFUA, &sh->dev[i].flags) &&
log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK) {
io->has_fua = 1;
/*
* we need to flush journal to make sure recovery can
* reach the data with fua flag
*/
io->has_flush = 1;
}
r5l_append_payload_meta(log, R5LOG_PAYLOAD_DATA,
raid5_compute_blocknr(sh, i, 0),
sh->dev[i].log_checksum, 0, false);
r5l_append_payload_page(log, sh->dev[i].page);
}
if (parity_pages == 2) {
r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY,
sh->sector, sh->dev[sh->pd_idx].log_checksum,
sh->dev[sh->qd_idx].log_checksum, true);
r5l_append_payload_page(log, sh->dev[sh->pd_idx].page);
r5l_append_payload_page(log, sh->dev[sh->qd_idx].page);
} else if (parity_pages == 1) {
r5l_append_payload_meta(log, R5LOG_PAYLOAD_PARITY,
sh->sector, sh->dev[sh->pd_idx].log_checksum,
0, false);
r5l_append_payload_page(log, sh->dev[sh->pd_idx].page);
} else /* Just writing data, not parity, in caching phase */
BUG_ON(parity_pages != 0);
list_add_tail(&sh->log_list, &io->stripe_list);
atomic_inc(&io->pending_stripe);
sh->log_io = io;
if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
return 0;
if (sh->log_start == MaxSector) {
BUG_ON(!list_empty(&sh->r5c));
sh->log_start = io->log_start;
spin_lock_irq(&log->stripe_in_journal_lock);
list_add_tail(&sh->r5c,
&log->stripe_in_journal_list);
spin_unlock_irq(&log->stripe_in_journal_lock);
atomic_inc(&log->stripe_in_journal_count);
}
return 0;
}
/* add stripe to no_space_stripes, and then wake up reclaim */
static inline void r5l_add_no_space_stripe(struct r5l_log *log,
struct stripe_head *sh)
{
spin_lock(&log->no_space_stripes_lock);
list_add_tail(&sh->log_list, &log->no_space_stripes);
spin_unlock(&log->no_space_stripes_lock);
}
/*
* running in raid5d, where reclaim could wait for raid5d too (when it flushes
* data from log to raid disks), so we shouldn't wait for reclaim here
*/
int r5l_write_stripe(struct r5l_log *log, struct stripe_head *sh)
{
struct r5conf *conf = sh->raid_conf;
int write_disks = 0;
int data_pages, parity_pages;
int reserve;
int i;
int ret = 0;
bool wake_reclaim = false;
if (!log)
return -EAGAIN;
/* Don't support stripe batch */
if (sh->log_io || !test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags) ||
test_bit(STRIPE_SYNCING, &sh->state)) {
/* the stripe is written to log, we start writing it to raid */
clear_bit(STRIPE_LOG_TRAPPED, &sh->state);
return -EAGAIN;
}
WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
for (i = 0; i < sh->disks; i++) {
void *addr;
if (!test_bit(R5_Wantwrite, &sh->dev[i].flags) ||
test_bit(R5_InJournal, &sh->dev[i].flags))
continue;
write_disks++;
/* checksum is already calculated in last run */
if (test_bit(STRIPE_LOG_TRAPPED, &sh->state))
continue;
addr = kmap_atomic(sh->dev[i].page);
sh->dev[i].log_checksum = crc32c_le(log->uuid_checksum,
addr, PAGE_SIZE);
kunmap_atomic(addr);
}
parity_pages = 1 + !!(sh->qd_idx >= 0);
data_pages = write_disks - parity_pages;
set_bit(STRIPE_LOG_TRAPPED, &sh->state);
/*
* The stripe must enter state machine again to finish the write, so
* don't delay.
*/
clear_bit(STRIPE_DELAYED, &sh->state);
atomic_inc(&sh->count);
mutex_lock(&log->io_mutex);
/* meta + data */
reserve = (1 + write_disks) << (PAGE_SHIFT - 9);
if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
if (!r5l_has_free_space(log, reserve)) {
r5l_add_no_space_stripe(log, sh);
wake_reclaim = true;
} else {
ret = r5l_log_stripe(log, sh, data_pages, parity_pages);
if (ret) {
spin_lock_irq(&log->io_list_lock);
list_add_tail(&sh->log_list,
&log->no_mem_stripes);
spin_unlock_irq(&log->io_list_lock);
}
}
} else { /* R5C_JOURNAL_MODE_WRITE_BACK */
/*
* log space critical, do not process stripes that are
* not in cache yet (sh->log_start == MaxSector).
*/
if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state) &&
sh->log_start == MaxSector) {
r5l_add_no_space_stripe(log, sh);
wake_reclaim = true;
reserve = 0;
} else if (!r5l_has_free_space(log, reserve)) {
if (sh->log_start == log->last_checkpoint)
BUG();
else
r5l_add_no_space_stripe(log, sh);
} else {
ret = r5l_log_stripe(log, sh, data_pages, parity_pages);
if (ret) {
spin_lock_irq(&log->io_list_lock);
list_add_tail(&sh->log_list,
&log->no_mem_stripes);
spin_unlock_irq(&log->io_list_lock);
}
}
}
mutex_unlock(&log->io_mutex);
if (wake_reclaim)
r5l_wake_reclaim(log, reserve);
return 0;
}
void r5l_write_stripe_run(struct r5l_log *log)
{
if (!log)
return;
mutex_lock(&log->io_mutex);
r5l_submit_current_io(log);
mutex_unlock(&log->io_mutex);
}
int r5l_handle_flush_request(struct r5l_log *log, struct bio *bio)
{
if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH) {
/*
* in write through (journal only)
* we flush log disk cache first, then write stripe data to
* raid disks. So if bio is finished, the log disk cache is
* flushed already. The recovery guarantees we can recovery
* the bio from log disk, so we don't need to flush again
*/
if (bio->bi_iter.bi_size == 0) {
bio_endio(bio);
return 0;
}
bio->bi_opf &= ~REQ_PREFLUSH;
} else {
/* write back (with cache) */
if (bio->bi_iter.bi_size == 0) {
mutex_lock(&log->io_mutex);
r5l_get_meta(log, 0);
bio_list_add(&log->current_io->flush_barriers, bio);
log->current_io->has_flush = 1;
log->current_io->has_null_flush = 1;
atomic_inc(&log->current_io->pending_stripe);
r5l_submit_current_io(log);
mutex_unlock(&log->io_mutex);
return 0;
}
}
return -EAGAIN;
}
/* This will run after log space is reclaimed */
static void r5l_run_no_space_stripes(struct r5l_log *log)
{
struct stripe_head *sh;
spin_lock(&log->no_space_stripes_lock);
while (!list_empty(&log->no_space_stripes)) {
sh = list_first_entry(&log->no_space_stripes,
struct stripe_head, log_list);
list_del_init(&sh->log_list);
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
}
spin_unlock(&log->no_space_stripes_lock);
}
/*
* calculate new last_checkpoint
* for write through mode, returns log->next_checkpoint
* for write back, returns log_start of first sh in stripe_in_journal_list
*/
static sector_t r5c_calculate_new_cp(struct r5conf *conf)
{
struct stripe_head *sh;
struct r5l_log *log = conf->log;
sector_t new_cp;
unsigned long flags;
if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
return log->next_checkpoint;
spin_lock_irqsave(&log->stripe_in_journal_lock, flags);
if (list_empty(&conf->log->stripe_in_journal_list)) {
/* all stripes flushed */
spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
return log->next_checkpoint;
}
sh = list_first_entry(&conf->log->stripe_in_journal_list,
struct stripe_head, r5c);
new_cp = sh->log_start;
spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
return new_cp;
}
static sector_t r5l_reclaimable_space(struct r5l_log *log)
{
struct r5conf *conf = log->rdev->mddev->private;
return r5l_ring_distance(log, log->last_checkpoint,
r5c_calculate_new_cp(conf));
}
static void r5l_run_no_mem_stripe(struct r5l_log *log)
{
struct stripe_head *sh;
lockdep_assert_held(&log->io_list_lock);
if (!list_empty(&log->no_mem_stripes)) {
sh = list_first_entry(&log->no_mem_stripes,
struct stripe_head, log_list);
list_del_init(&sh->log_list);
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
}
}
static bool r5l_complete_finished_ios(struct r5l_log *log)
{
struct r5l_io_unit *io, *next;
bool found = false;
lockdep_assert_held(&log->io_list_lock);
list_for_each_entry_safe(io, next, &log->finished_ios, log_sibling) {
/* don't change list order */
if (io->state < IO_UNIT_STRIPE_END)
break;
log->next_checkpoint = io->log_start;
list_del(&io->log_sibling);
mempool_free(io, &log->io_pool);
r5l_run_no_mem_stripe(log);
found = true;
}
return found;
}
static void __r5l_stripe_write_finished(struct r5l_io_unit *io)
{
struct r5l_log *log = io->log;
struct r5conf *conf = log->rdev->mddev->private;
unsigned long flags;
spin_lock_irqsave(&log->io_list_lock, flags);
__r5l_set_io_unit_state(io, IO_UNIT_STRIPE_END);
if (!r5l_complete_finished_ios(log)) {
spin_unlock_irqrestore(&log->io_list_lock, flags);
return;
}
if (r5l_reclaimable_space(log) > log->max_free_space ||
test_bit(R5C_LOG_TIGHT, &conf->cache_state))
r5l_wake_reclaim(log, 0);
spin_unlock_irqrestore(&log->io_list_lock, flags);
wake_up(&log->iounit_wait);
}
void r5l_stripe_write_finished(struct stripe_head *sh)
{
struct r5l_io_unit *io;
io = sh->log_io;
sh->log_io = NULL;
if (io && atomic_dec_and_test(&io->pending_stripe))
__r5l_stripe_write_finished(io);
}
static void r5l_log_flush_endio(struct bio *bio)
{
struct r5l_log *log = container_of(bio, struct r5l_log,
flush_bio);
unsigned long flags;
struct r5l_io_unit *io;
if (bio->bi_status)
md_error(log->rdev->mddev, log->rdev);
bio_uninit(bio);
spin_lock_irqsave(&log->io_list_lock, flags);
list_for_each_entry(io, &log->flushing_ios, log_sibling)
r5l_io_run_stripes(io);
list_splice_tail_init(&log->flushing_ios, &log->finished_ios);
spin_unlock_irqrestore(&log->io_list_lock, flags);
}
/*
* Starting dispatch IO to raid.
* io_unit(meta) consists of a log. There is one situation we want to avoid. A
* broken meta in the middle of a log causes recovery can't find meta at the
* head of log. If operations require meta at the head persistent in log, we
* must make sure meta before it persistent in log too. A case is:
*
* stripe data/parity is in log, we start write stripe to raid disks. stripe
* data/parity must be persistent in log before we do the write to raid disks.
*
* The solution is we restrictly maintain io_unit list order. In this case, we
* only write stripes of an io_unit to raid disks till the io_unit is the first
* one whose data/parity is in log.
*/
void r5l_flush_stripe_to_raid(struct r5l_log *log)
{
bool do_flush;
if (!log || !log->need_cache_flush)
return;
spin_lock_irq(&log->io_list_lock);
/* flush bio is running */
if (!list_empty(&log->flushing_ios)) {
spin_unlock_irq(&log->io_list_lock);
return;
}
list_splice_tail_init(&log->io_end_ios, &log->flushing_ios);
do_flush = !list_empty(&log->flushing_ios);
spin_unlock_irq(&log->io_list_lock);
if (!do_flush)
return;
bio_init(&log->flush_bio, log->rdev->bdev, NULL, 0,
REQ_OP_WRITE | REQ_PREFLUSH);
log->flush_bio.bi_end_io = r5l_log_flush_endio;
submit_bio(&log->flush_bio);
}
static void r5l_write_super(struct r5l_log *log, sector_t cp);
static void r5l_write_super_and_discard_space(struct r5l_log *log,
sector_t end)
{
struct block_device *bdev = log->rdev->bdev;
struct mddev *mddev;
r5l_write_super(log, end);
if (!bdev_max_discard_sectors(bdev))
return;
mddev = log->rdev->mddev;
/*
* Discard could zero data, so before discard we must make sure
* superblock is updated to new log tail. Updating superblock (either
* directly call md_update_sb() or depend on md thread) must hold
* reconfig mutex. On the other hand, raid5_quiesce is called with
* reconfig_mutex hold. The first step of raid5_quiesce() is waiting
* for all IO finish, hence waiting for reclaim thread, while reclaim
* thread is calling this function and waiting for reconfig mutex. So
* there is a deadlock. We workaround this issue with a trylock.
* FIXME: we could miss discard if we can't take reconfig mutex
*/
set_mask_bits(&mddev->sb_flags, 0,
BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
if (!mddev_trylock(mddev))
return;
md_update_sb(mddev, 1);
mddev_unlock(mddev);
/* discard IO error really doesn't matter, ignore it */
if (log->last_checkpoint < end) {
blkdev_issue_discard(bdev,
log->last_checkpoint + log->rdev->data_offset,
end - log->last_checkpoint, GFP_NOIO);
} else {
blkdev_issue_discard(bdev,
log->last_checkpoint + log->rdev->data_offset,
log->device_size - log->last_checkpoint,
GFP_NOIO);
blkdev_issue_discard(bdev, log->rdev->data_offset, end,
GFP_NOIO);
}
}
/*
* r5c_flush_stripe moves stripe from cached list to handle_list. When called,
* the stripe must be on r5c_cached_full_stripes or r5c_cached_partial_stripes.
*
* must hold conf->device_lock
*/
static void r5c_flush_stripe(struct r5conf *conf, struct stripe_head *sh)
{
BUG_ON(list_empty(&sh->lru));
BUG_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
/*
* The stripe is not ON_RELEASE_LIST, so it is safe to call
* raid5_release_stripe() while holding conf->device_lock
*/
BUG_ON(test_bit(STRIPE_ON_RELEASE_LIST, &sh->state));
lockdep_assert_held(&conf->device_lock);
list_del_init(&sh->lru);
atomic_inc(&sh->count);
set_bit(STRIPE_HANDLE, &sh->state);
atomic_inc(&conf->active_stripes);
r5c_make_stripe_write_out(sh);
if (test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state))
atomic_inc(&conf->r5c_flushing_partial_stripes);
else
atomic_inc(&conf->r5c_flushing_full_stripes);
raid5_release_stripe(sh);
}
/*
* if num == 0, flush all full stripes
* if num > 0, flush all full stripes. If less than num full stripes are
* flushed, flush some partial stripes until totally num stripes are
* flushed or there is no more cached stripes.
*/
void r5c_flush_cache(struct r5conf *conf, int num)
{
int count;
struct stripe_head *sh, *next;
lockdep_assert_held(&conf->device_lock);
if (!conf->log)
return;
count = 0;
list_for_each_entry_safe(sh, next, &conf->r5c_full_stripe_list, lru) {
r5c_flush_stripe(conf, sh);
count++;
}
if (count >= num)
return;
list_for_each_entry_safe(sh, next,
&conf->r5c_partial_stripe_list, lru) {
r5c_flush_stripe(conf, sh);
if (++count >= num)
break;
}
}
static void r5c_do_reclaim(struct r5conf *conf)
{
struct r5l_log *log = conf->log;
struct stripe_head *sh;
int count = 0;
unsigned long flags;
int total_cached;
int stripes_to_flush;
int flushing_partial, flushing_full;
if (!r5c_is_writeback(log))
return;
flushing_partial = atomic_read(&conf->r5c_flushing_partial_stripes);
flushing_full = atomic_read(&conf->r5c_flushing_full_stripes);
total_cached = atomic_read(&conf->r5c_cached_partial_stripes) +
atomic_read(&conf->r5c_cached_full_stripes) -
flushing_full - flushing_partial;
if (total_cached > conf->min_nr_stripes * 3 / 4 ||
atomic_read(&conf->empty_inactive_list_nr) > 0)
/*
* if stripe cache pressure high, flush all full stripes and
* some partial stripes
*/
stripes_to_flush = R5C_RECLAIM_STRIPE_GROUP;
else if (total_cached > conf->min_nr_stripes * 1 / 2 ||
atomic_read(&conf->r5c_cached_full_stripes) - flushing_full >
R5C_FULL_STRIPE_FLUSH_BATCH(conf))
/*
* if stripe cache pressure moderate, or if there is many full
* stripes,flush all full stripes
*/
stripes_to_flush = 0;
else
/* no need to flush */
stripes_to_flush = -1;
if (stripes_to_flush >= 0) {
spin_lock_irqsave(&conf->device_lock, flags);
r5c_flush_cache(conf, stripes_to_flush);
spin_unlock_irqrestore(&conf->device_lock, flags);
}
/* if log space is tight, flush stripes on stripe_in_journal_list */
if (test_bit(R5C_LOG_TIGHT, &conf->cache_state)) {
spin_lock_irqsave(&log->stripe_in_journal_lock, flags);
spin_lock(&conf->device_lock);
list_for_each_entry(sh, &log->stripe_in_journal_list, r5c) {
/*
* stripes on stripe_in_journal_list could be in any
* state of the stripe_cache state machine. In this
* case, we only want to flush stripe on
* r5c_cached_full/partial_stripes. The following
* condition makes sure the stripe is on one of the
* two lists.
*/
if (!list_empty(&sh->lru) &&
!test_bit(STRIPE_HANDLE, &sh->state) &&
atomic_read(&sh->count) == 0) {
r5c_flush_stripe(conf, sh);
if (count++ >= R5C_RECLAIM_STRIPE_GROUP)
break;
}
}
spin_unlock(&conf->device_lock);
spin_unlock_irqrestore(&log->stripe_in_journal_lock, flags);
}
if (!test_bit(R5C_LOG_CRITICAL, &conf->cache_state))
r5l_run_no_space_stripes(log);
md_wakeup_thread(conf->mddev->thread);
}
static void r5l_do_reclaim(struct r5l_log *log)
{
struct r5conf *conf = log->rdev->mddev->private;
sector_t reclaim_target = xchg(&log->reclaim_target, 0);
sector_t reclaimable;
sector_t next_checkpoint;
bool write_super;
spin_lock_irq(&log->io_list_lock);
write_super = r5l_reclaimable_space(log) > log->max_free_space ||
reclaim_target != 0 || !list_empty(&log->no_space_stripes);
/*
* move proper io_unit to reclaim list. We should not change the order.
* reclaimable/unreclaimable io_unit can be mixed in the list, we
* shouldn't reuse space of an unreclaimable io_unit
*/
while (1) {
reclaimable = r5l_reclaimable_space(log);
if (reclaimable >= reclaim_target ||
(list_empty(&log->running_ios) &&
list_empty(&log->io_end_ios) &&
list_empty(&log->flushing_ios) &&
list_empty(&log->finished_ios)))
break;
md_wakeup_thread(log->rdev->mddev->thread);
wait_event_lock_irq(log->iounit_wait,
r5l_reclaimable_space(log) > reclaimable,
log->io_list_lock);
}
next_checkpoint = r5c_calculate_new_cp(conf);
spin_unlock_irq(&log->io_list_lock);
if (reclaimable == 0 || !write_super)
return;
/*
* write_super will flush cache of each raid disk. We must write super
* here, because the log area might be reused soon and we don't want to
* confuse recovery
*/
r5l_write_super_and_discard_space(log, next_checkpoint);
mutex_lock(&log->io_mutex);
log->last_checkpoint = next_checkpoint;
r5c_update_log_state(log);
mutex_unlock(&log->io_mutex);
r5l_run_no_space_stripes(log);
}
static void r5l_reclaim_thread(struct md_thread *thread)
{
struct mddev *mddev = thread->mddev;
struct r5conf *conf = mddev->private;
struct r5l_log *log = conf->log;
if (!log)
return;
r5c_do_reclaim(conf);
r5l_do_reclaim(log);
}
void r5l_wake_reclaim(struct r5l_log *log, sector_t space)
{
unsigned long target;
unsigned long new = (unsigned long)space; /* overflow in theory */
if (!log)
return;
target = READ_ONCE(log->reclaim_target);
do {
if (new < target)
return;
} while (!try_cmpxchg(&log->reclaim_target, &target, new));
md_wakeup_thread(log->reclaim_thread);
}
void r5l_quiesce(struct r5l_log *log, int quiesce)
{
struct mddev *mddev = log->rdev->mddev;
struct md_thread *thread = rcu_dereference_protected(
log->reclaim_thread, lockdep_is_held(&mddev->reconfig_mutex));
if (quiesce) {
/* make sure r5l_write_super_and_discard_space exits */
wake_up(&mddev->sb_wait);
kthread_park(thread->tsk);
r5l_wake_reclaim(log, MaxSector);
r5l_do_reclaim(log);
} else
kthread_unpark(thread->tsk);
}
bool r5l_log_disk_error(struct r5conf *conf)
{
struct r5l_log *log = conf->log;
/* don't allow write if journal disk is missing */
if (!log)
return test_bit(MD_HAS_JOURNAL, &conf->mddev->flags);
else
return test_bit(Faulty, &log->rdev->flags);
}
#define R5L_RECOVERY_PAGE_POOL_SIZE 256
struct r5l_recovery_ctx {
struct page *meta_page; /* current meta */
sector_t meta_total_blocks; /* total size of current meta and data */
sector_t pos; /* recovery position */
u64 seq; /* recovery position seq */
int data_parity_stripes; /* number of data_parity stripes */
int data_only_stripes; /* number of data_only stripes */
struct list_head cached_list;
/*
* read ahead page pool (ra_pool)
* in recovery, log is read sequentially. It is not efficient to
* read every page with sync_page_io(). The read ahead page pool
* reads multiple pages with one IO, so further log read can
* just copy data from the pool.
*/
struct page *ra_pool[R5L_RECOVERY_PAGE_POOL_SIZE];
struct bio_vec ra_bvec[R5L_RECOVERY_PAGE_POOL_SIZE];
sector_t pool_offset; /* offset of first page in the pool */
int total_pages; /* total allocated pages */
int valid_pages; /* pages with valid data */
};
static int r5l_recovery_allocate_ra_pool(struct r5l_log *log,
struct r5l_recovery_ctx *ctx)
{
struct page *page;
ctx->valid_pages = 0;
ctx->total_pages = 0;
while (ctx->total_pages < R5L_RECOVERY_PAGE_POOL_SIZE) {
page = alloc_page(GFP_KERNEL);
if (!page)
break;
ctx->ra_pool[ctx->total_pages] = page;
ctx->total_pages += 1;
}
if (ctx->total_pages == 0)
return -ENOMEM;
ctx->pool_offset = 0;
return 0;
}
static void r5l_recovery_free_ra_pool(struct r5l_log *log,
struct r5l_recovery_ctx *ctx)
{
int i;
for (i = 0; i < ctx->total_pages; ++i)
put_page(ctx->ra_pool[i]);
}
/*
* fetch ctx->valid_pages pages from offset
* In normal cases, ctx->valid_pages == ctx->total_pages after the call.
* However, if the offset is close to the end of the journal device,
* ctx->valid_pages could be smaller than ctx->total_pages
*/
static int r5l_recovery_fetch_ra_pool(struct r5l_log *log,
struct r5l_recovery_ctx *ctx,
sector_t offset)
{
struct bio bio;
int ret;
bio_init(&bio, log->rdev->bdev, ctx->ra_bvec,
R5L_RECOVERY_PAGE_POOL_SIZE, REQ_OP_READ);
bio.bi_iter.bi_sector = log->rdev->data_offset + offset;
ctx->valid_pages = 0;
ctx->pool_offset = offset;
while (ctx->valid_pages < ctx->total_pages) {
__bio_add_page(&bio, ctx->ra_pool[ctx->valid_pages], PAGE_SIZE,
0);
ctx->valid_pages += 1;
offset = r5l_ring_add(log, offset, BLOCK_SECTORS);
if (offset == 0) /* reached end of the device */
break;
}
ret = submit_bio_wait(&bio);
bio_uninit(&bio);
return ret;
}
/*
* try read a page from the read ahead page pool, if the page is not in the
* pool, call r5l_recovery_fetch_ra_pool
*/
static int r5l_recovery_read_page(struct r5l_log *log,
struct r5l_recovery_ctx *ctx,
struct page *page,
sector_t offset)
{
int ret;
if (offset < ctx->pool_offset ||
offset >= ctx->pool_offset + ctx->valid_pages * BLOCK_SECTORS) {
ret = r5l_recovery_fetch_ra_pool(log, ctx, offset);
if (ret)
return ret;
}
BUG_ON(offset < ctx->pool_offset ||
offset >= ctx->pool_offset + ctx->valid_pages * BLOCK_SECTORS);
memcpy(page_address(page),
page_address(ctx->ra_pool[(offset - ctx->pool_offset) >>
BLOCK_SECTOR_SHIFT]),
PAGE_SIZE);
return 0;
}
static int r5l_recovery_read_meta_block(struct r5l_log *log,
struct r5l_recovery_ctx *ctx)
{
struct page *page = ctx->meta_page;
struct r5l_meta_block *mb;
u32 crc, stored_crc;
int ret;
ret = r5l_recovery_read_page(log, ctx, page, ctx->pos);
if (ret != 0)
return ret;
mb = page_address(page);
stored_crc = le32_to_cpu(mb->checksum);
mb->checksum = 0;
if (le32_to_cpu(mb->magic) != R5LOG_MAGIC ||
le64_to_cpu(mb->seq) != ctx->seq ||
mb->version != R5LOG_VERSION ||
le64_to_cpu(mb->position) != ctx->pos)
return -EINVAL;
crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
if (stored_crc != crc)
return -EINVAL;
if (le32_to_cpu(mb->meta_size) > PAGE_SIZE)
return -EINVAL;
ctx->meta_total_blocks = BLOCK_SECTORS;
return 0;
}
static void
r5l_recovery_create_empty_meta_block(struct r5l_log *log,
struct page *page,
sector_t pos, u64 seq)
{
struct r5l_meta_block *mb;
mb = page_address(page);
clear_page(mb);
mb->magic = cpu_to_le32(R5LOG_MAGIC);
mb->version = R5LOG_VERSION;
mb->meta_size = cpu_to_le32(sizeof(struct r5l_meta_block));
mb->seq = cpu_to_le64(seq);
mb->position = cpu_to_le64(pos);
}
static int r5l_log_write_empty_meta_block(struct r5l_log *log, sector_t pos,
u64 seq)
{
struct page *page;
struct r5l_meta_block *mb;
page = alloc_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
r5l_recovery_create_empty_meta_block(log, page, pos, seq);
mb = page_address(page);
mb->checksum = cpu_to_le32(crc32c_le(log->uuid_checksum,
mb, PAGE_SIZE));
if (!sync_page_io(log->rdev, pos, PAGE_SIZE, page, REQ_OP_WRITE |
REQ_SYNC | REQ_FUA, false)) {
__free_page(page);
return -EIO;
}
__free_page(page);
return 0;
}
/*
* r5l_recovery_load_data and r5l_recovery_load_parity uses flag R5_Wantwrite
* to mark valid (potentially not flushed) data in the journal.
*
* We already verified checksum in r5l_recovery_verify_data_checksum_for_mb,
* so there should not be any mismatch here.
*/
static void r5l_recovery_load_data(struct r5l_log *log,
struct stripe_head *sh,
struct r5l_recovery_ctx *ctx,
struct r5l_payload_data_parity *payload,
sector_t log_offset)
{
struct mddev *mddev = log->rdev->mddev;
struct r5conf *conf = mddev->private;
int dd_idx;
raid5_compute_sector(conf,
le64_to_cpu(payload->location), 0,
&dd_idx, sh);
r5l_recovery_read_page(log, ctx, sh->dev[dd_idx].page, log_offset);
sh->dev[dd_idx].log_checksum =
le32_to_cpu(payload->checksum[0]);
ctx->meta_total_blocks += BLOCK_SECTORS;
set_bit(R5_Wantwrite, &sh->dev[dd_idx].flags);
set_bit(STRIPE_R5C_CACHING, &sh->state);
}
static void r5l_recovery_load_parity(struct r5l_log *log,
struct stripe_head *sh,
struct r5l_recovery_ctx *ctx,
struct r5l_payload_data_parity *payload,
sector_t log_offset)
{
struct mddev *mddev = log->rdev->mddev;
struct r5conf *conf = mddev->private;
ctx->meta_total_blocks += BLOCK_SECTORS * conf->max_degraded;
r5l_recovery_read_page(log, ctx, sh->dev[sh->pd_idx].page, log_offset);
sh->dev[sh->pd_idx].log_checksum =
le32_to_cpu(payload->checksum[0]);
set_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags);
if (sh->qd_idx >= 0) {
r5l_recovery_read_page(
log, ctx, sh->dev[sh->qd_idx].page,
r5l_ring_add(log, log_offset, BLOCK_SECTORS));
sh->dev[sh->qd_idx].log_checksum =
le32_to_cpu(payload->checksum[1]);
set_bit(R5_Wantwrite, &sh->dev[sh->qd_idx].flags);
}
clear_bit(STRIPE_R5C_CACHING, &sh->state);
}
static void r5l_recovery_reset_stripe(struct stripe_head *sh)
{
int i;
sh->state = 0;
sh->log_start = MaxSector;
for (i = sh->disks; i--; )
sh->dev[i].flags = 0;
}
static void
r5l_recovery_replay_one_stripe(struct r5conf *conf,
struct stripe_head *sh,
struct r5l_recovery_ctx *ctx)
{
struct md_rdev *rdev, *rrdev;
int disk_index;
int data_count = 0;
for (disk_index = 0; disk_index < sh->disks; disk_index++) {
if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags))
continue;
if (disk_index == sh->qd_idx || disk_index == sh->pd_idx)
continue;
data_count++;
}
/*
* stripes that only have parity must have been flushed
* before the crash that we are now recovering from, so
* there is nothing more to recovery.
*/
if (data_count == 0)
goto out;
for (disk_index = 0; disk_index < sh->disks; disk_index++) {
if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags))
continue;
/* in case device is broken */
rcu_read_lock();
rdev = rcu_dereference(conf->disks[disk_index].rdev);
if (rdev) {
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
sync_page_io(rdev, sh->sector, PAGE_SIZE,
sh->dev[disk_index].page, REQ_OP_WRITE,
false);
rdev_dec_pending(rdev, rdev->mddev);
rcu_read_lock();
}
rrdev = rcu_dereference(conf->disks[disk_index].replacement);
if (rrdev) {
atomic_inc(&rrdev->nr_pending);
rcu_read_unlock();
sync_page_io(rrdev, sh->sector, PAGE_SIZE,
sh->dev[disk_index].page, REQ_OP_WRITE,
false);
rdev_dec_pending(rrdev, rrdev->mddev);
rcu_read_lock();
}
rcu_read_unlock();
}
ctx->data_parity_stripes++;
out:
r5l_recovery_reset_stripe(sh);
}
static struct stripe_head *
r5c_recovery_alloc_stripe(
struct r5conf *conf,
sector_t stripe_sect,
int noblock)
{
struct stripe_head *sh;
sh = raid5_get_active_stripe(conf, NULL, stripe_sect,
noblock ? R5_GAS_NOBLOCK : 0);
if (!sh)
return NULL; /* no more stripe available */
r5l_recovery_reset_stripe(sh);
return sh;
}
static struct stripe_head *
r5c_recovery_lookup_stripe(struct list_head *list, sector_t sect)
{
struct stripe_head *sh;
list_for_each_entry(sh, list, lru)
if (sh->sector == sect)
return sh;
return NULL;
}
static void
r5c_recovery_drop_stripes(struct list_head *cached_stripe_list,
struct r5l_recovery_ctx *ctx)
{
struct stripe_head *sh, *next;
list_for_each_entry_safe(sh, next, cached_stripe_list, lru) {
r5l_recovery_reset_stripe(sh);
list_del_init(&sh->lru);
raid5_release_stripe(sh);
}
}
static void
r5c_recovery_replay_stripes(struct list_head *cached_stripe_list,
struct r5l_recovery_ctx *ctx)
{
struct stripe_head *sh, *next;
list_for_each_entry_safe(sh, next, cached_stripe_list, lru)
if (!test_bit(STRIPE_R5C_CACHING, &sh->state)) {
r5l_recovery_replay_one_stripe(sh->raid_conf, sh, ctx);
list_del_init(&sh->lru);
raid5_release_stripe(sh);
}
}
/* if matches return 0; otherwise return -EINVAL */
static int
r5l_recovery_verify_data_checksum(struct r5l_log *log,
struct r5l_recovery_ctx *ctx,
struct page *page,
sector_t log_offset, __le32 log_checksum)
{
void *addr;
u32 checksum;
r5l_recovery_read_page(log, ctx, page, log_offset);
addr = kmap_atomic(page);
checksum = crc32c_le(log->uuid_checksum, addr, PAGE_SIZE);
kunmap_atomic(addr);
return (le32_to_cpu(log_checksum) == checksum) ? 0 : -EINVAL;
}
/*
* before loading data to stripe cache, we need verify checksum for all data,
* if there is mismatch for any data page, we drop all data in the mata block
*/
static int
r5l_recovery_verify_data_checksum_for_mb(struct r5l_log *log,
struct r5l_recovery_ctx *ctx)
{
struct mddev *mddev = log->rdev->mddev;
struct r5conf *conf = mddev->private;
struct r5l_meta_block *mb = page_address(ctx->meta_page);
sector_t mb_offset = sizeof(struct r5l_meta_block);
sector_t log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
struct page *page;
struct r5l_payload_data_parity *payload;
struct r5l_payload_flush *payload_flush;
page = alloc_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
while (mb_offset < le32_to_cpu(mb->meta_size)) {
payload = (void *)mb + mb_offset;
payload_flush = (void *)mb + mb_offset;
if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_DATA) {
if (r5l_recovery_verify_data_checksum(
log, ctx, page, log_offset,
payload->checksum[0]) < 0)
goto mismatch;
} else if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_PARITY) {
if (r5l_recovery_verify_data_checksum(
log, ctx, page, log_offset,
payload->checksum[0]) < 0)
goto mismatch;
if (conf->max_degraded == 2 && /* q for RAID 6 */
r5l_recovery_verify_data_checksum(
log, ctx, page,
r5l_ring_add(log, log_offset,
BLOCK_SECTORS),
payload->checksum[1]) < 0)
goto mismatch;
} else if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_FLUSH) {
/* nothing to do for R5LOG_PAYLOAD_FLUSH here */
} else /* not R5LOG_PAYLOAD_DATA/PARITY/FLUSH */
goto mismatch;
if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_FLUSH) {
mb_offset += sizeof(struct r5l_payload_flush) +
le32_to_cpu(payload_flush->size);
} else {
/* DATA or PARITY payload */
log_offset = r5l_ring_add(log, log_offset,
le32_to_cpu(payload->size));
mb_offset += sizeof(struct r5l_payload_data_parity) +
sizeof(__le32) *
(le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
}
}
put_page(page);
return 0;
mismatch:
put_page(page);
return -EINVAL;
}
/*
* Analyze all data/parity pages in one meta block
* Returns:
* 0 for success
* -EINVAL for unknown playload type
* -EAGAIN for checksum mismatch of data page
* -ENOMEM for run out of memory (alloc_page failed or run out of stripes)
*/
static int
r5c_recovery_analyze_meta_block(struct r5l_log *log,
struct r5l_recovery_ctx *ctx,
struct list_head *cached_stripe_list)
{
struct mddev *mddev = log->rdev->mddev;
struct r5conf *conf = mddev->private;
struct r5l_meta_block *mb;
struct r5l_payload_data_parity *payload;
struct r5l_payload_flush *payload_flush;
int mb_offset;
sector_t log_offset;
sector_t stripe_sect;
struct stripe_head *sh;
int ret;
/*
* for mismatch in data blocks, we will drop all data in this mb, but
* we will still read next mb for other data with FLUSH flag, as
* io_unit could finish out of order.
*/
ret = r5l_recovery_verify_data_checksum_for_mb(log, ctx);
if (ret == -EINVAL)
return -EAGAIN;
else if (ret)
return ret; /* -ENOMEM duo to alloc_page() failed */
mb = page_address(ctx->meta_page);
mb_offset = sizeof(struct r5l_meta_block);
log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
while (mb_offset < le32_to_cpu(mb->meta_size)) {
int dd;
payload = (void *)mb + mb_offset;
payload_flush = (void *)mb + mb_offset;
if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_FLUSH) {
int i, count;
count = le32_to_cpu(payload_flush->size) / sizeof(__le64);
for (i = 0; i < count; ++i) {
stripe_sect = le64_to_cpu(payload_flush->flush_stripes[i]);
sh = r5c_recovery_lookup_stripe(cached_stripe_list,
stripe_sect);
if (sh) {
WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
r5l_recovery_reset_stripe(sh);
list_del_init(&sh->lru);
raid5_release_stripe(sh);
}
}
mb_offset += sizeof(struct r5l_payload_flush) +
le32_to_cpu(payload_flush->size);
continue;
}
/* DATA or PARITY payload */
stripe_sect = (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_DATA) ?
raid5_compute_sector(
conf, le64_to_cpu(payload->location), 0, &dd,
NULL)
: le64_to_cpu(payload->location);
sh = r5c_recovery_lookup_stripe(cached_stripe_list,
stripe_sect);
if (!sh) {
sh = r5c_recovery_alloc_stripe(conf, stripe_sect, 1);
/*
* cannot get stripe from raid5_get_active_stripe
* try replay some stripes
*/
if (!sh) {
r5c_recovery_replay_stripes(
cached_stripe_list, ctx);
sh = r5c_recovery_alloc_stripe(
conf, stripe_sect, 1);
}
if (!sh) {
int new_size = conf->min_nr_stripes * 2;
pr_debug("md/raid:%s: Increasing stripe cache size to %d to recovery data on journal.\n",
mdname(mddev),
new_size);
ret = raid5_set_cache_size(mddev, new_size);
if (conf->min_nr_stripes <= new_size / 2) {
pr_err("md/raid:%s: Cannot increase cache size, ret=%d, new_size=%d, min_nr_stripes=%d, max_nr_stripes=%d\n",
mdname(mddev),
ret,
new_size,
conf->min_nr_stripes,
conf->max_nr_stripes);
return -ENOMEM;
}
sh = r5c_recovery_alloc_stripe(
conf, stripe_sect, 0);
}
if (!sh) {
pr_err("md/raid:%s: Cannot get enough stripes due to memory pressure. Recovery failed.\n",
mdname(mddev));
return -ENOMEM;
}
list_add_tail(&sh->lru, cached_stripe_list);
}
if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_DATA) {
if (!test_bit(STRIPE_R5C_CACHING, &sh->state) &&
test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags)) {
r5l_recovery_replay_one_stripe(conf, sh, ctx);
list_move_tail(&sh->lru, cached_stripe_list);
}
r5l_recovery_load_data(log, sh, ctx, payload,
log_offset);
} else if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_PARITY)
r5l_recovery_load_parity(log, sh, ctx, payload,
log_offset);
else
return -EINVAL;
log_offset = r5l_ring_add(log, log_offset,
le32_to_cpu(payload->size));
mb_offset += sizeof(struct r5l_payload_data_parity) +
sizeof(__le32) *
(le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
}
return 0;
}
/*
* Load the stripe into cache. The stripe will be written out later by
* the stripe cache state machine.
*/
static void r5c_recovery_load_one_stripe(struct r5l_log *log,
struct stripe_head *sh)
{
struct r5dev *dev;
int i;
for (i = sh->disks; i--; ) {
dev = sh->dev + i;
if (test_and_clear_bit(R5_Wantwrite, &dev->flags)) {
set_bit(R5_InJournal, &dev->flags);
set_bit(R5_UPTODATE, &dev->flags);
}
}
}
/*
* Scan through the log for all to-be-flushed data
*
* For stripes with data and parity, namely Data-Parity stripe
* (STRIPE_R5C_CACHING == 0), we simply replay all the writes.
*
* For stripes with only data, namely Data-Only stripe
* (STRIPE_R5C_CACHING == 1), we load them to stripe cache state machine.
*
* For a stripe, if we see data after parity, we should discard all previous
* data and parity for this stripe, as these data are already flushed to
* the array.
*
* At the end of the scan, we return the new journal_tail, which points to
* first data-only stripe on the journal device, or next invalid meta block.
*/
static int r5c_recovery_flush_log(struct r5l_log *log,
struct r5l_recovery_ctx *ctx)
{
struct stripe_head *sh;
int ret = 0;
/* scan through the log */
while (1) {
if (r5l_recovery_read_meta_block(log, ctx))
break;
ret = r5c_recovery_analyze_meta_block(log, ctx,
&ctx->cached_list);
/*
* -EAGAIN means mismatch in data block, in this case, we still
* try scan the next metablock
*/
if (ret && ret != -EAGAIN)
break; /* ret == -EINVAL or -ENOMEM */
ctx->seq++;
ctx->pos = r5l_ring_add(log, ctx->pos, ctx->meta_total_blocks);
}
if (ret == -ENOMEM) {
r5c_recovery_drop_stripes(&ctx->cached_list, ctx);
return ret;
}
/* replay data-parity stripes */
r5c_recovery_replay_stripes(&ctx->cached_list, ctx);
/* load data-only stripes to stripe cache */
list_for_each_entry(sh, &ctx->cached_list, lru) {
WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
r5c_recovery_load_one_stripe(log, sh);
ctx->data_only_stripes++;
}
return 0;
}
/*
* we did a recovery. Now ctx.pos points to an invalid meta block. New
* log will start here. but we can't let superblock point to last valid
* meta block. The log might looks like:
* | meta 1| meta 2| meta 3|
* meta 1 is valid, meta 2 is invalid. meta 3 could be valid. If
* superblock points to meta 1, we write a new valid meta 2n. if crash
* happens again, new recovery will start from meta 1. Since meta 2n is
* valid now, recovery will think meta 3 is valid, which is wrong.
* The solution is we create a new meta in meta2 with its seq == meta
* 1's seq + 10000 and let superblock points to meta2. The same recovery
* will not think meta 3 is a valid meta, because its seq doesn't match
*/
/*
* Before recovery, the log looks like the following
*
* ---------------------------------------------
* | valid log | invalid log |
* ---------------------------------------------
* ^
* |- log->last_checkpoint
* |- log->last_cp_seq
*
* Now we scan through the log until we see invalid entry
*
* ---------------------------------------------
* | valid log | invalid log |
* ---------------------------------------------
* ^ ^
* |- log->last_checkpoint |- ctx->pos
* |- log->last_cp_seq |- ctx->seq
*
* From this point, we need to increase seq number by 10 to avoid
* confusing next recovery.
*
* ---------------------------------------------
* | valid log | invalid log |
* ---------------------------------------------
* ^ ^
* |- log->last_checkpoint |- ctx->pos+1
* |- log->last_cp_seq |- ctx->seq+10001
*
* However, it is not safe to start the state machine yet, because data only
* parities are not yet secured in RAID. To save these data only parities, we
* rewrite them from seq+11.
*
* -----------------------------------------------------------------
* | valid log | data only stripes | invalid log |
* -----------------------------------------------------------------
* ^ ^
* |- log->last_checkpoint |- ctx->pos+n
* |- log->last_cp_seq |- ctx->seq+10000+n
*
* If failure happens again during this process, the recovery can safe start
* again from log->last_checkpoint.
*
* Once data only stripes are rewritten to journal, we move log_tail
*
* -----------------------------------------------------------------
* | old log | data only stripes | invalid log |
* -----------------------------------------------------------------
* ^ ^
* |- log->last_checkpoint |- ctx->pos+n
* |- log->last_cp_seq |- ctx->seq+10000+n
*
* Then we can safely start the state machine. If failure happens from this
* point on, the recovery will start from new log->last_checkpoint.
*/
static int
r5c_recovery_rewrite_data_only_stripes(struct r5l_log *log,
struct r5l_recovery_ctx *ctx)
{
struct stripe_head *sh;
struct mddev *mddev = log->rdev->mddev;
struct page *page;
sector_t next_checkpoint = MaxSector;
page = alloc_page(GFP_KERNEL);
if (!page) {
pr_err("md/raid:%s: cannot allocate memory to rewrite data only stripes\n",
mdname(mddev));
return -ENOMEM;
}
WARN_ON(list_empty(&ctx->cached_list));
list_for_each_entry(sh, &ctx->cached_list, lru) {
struct r5l_meta_block *mb;
int i;
int offset;
sector_t write_pos;
WARN_ON(!test_bit(STRIPE_R5C_CACHING, &sh->state));
r5l_recovery_create_empty_meta_block(log, page,
ctx->pos, ctx->seq);
mb = page_address(page);
offset = le32_to_cpu(mb->meta_size);
write_pos = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
for (i = sh->disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
struct r5l_payload_data_parity *payload;
void *addr;
if (test_bit(R5_InJournal, &dev->flags)) {
payload = (void *)mb + offset;
payload->header.type = cpu_to_le16(
R5LOG_PAYLOAD_DATA);
payload->size = cpu_to_le32(BLOCK_SECTORS);
payload->location = cpu_to_le64(
raid5_compute_blocknr(sh, i, 0));
addr = kmap_atomic(dev->page);
payload->checksum[0] = cpu_to_le32(
crc32c_le(log->uuid_checksum, addr,
PAGE_SIZE));
kunmap_atomic(addr);
sync_page_io(log->rdev, write_pos, PAGE_SIZE,
dev->page, REQ_OP_WRITE, false);
write_pos = r5l_ring_add(log, write_pos,
BLOCK_SECTORS);
offset += sizeof(__le32) +
sizeof(struct r5l_payload_data_parity);
}
}
mb->meta_size = cpu_to_le32(offset);
mb->checksum = cpu_to_le32(crc32c_le(log->uuid_checksum,
mb, PAGE_SIZE));
sync_page_io(log->rdev, ctx->pos, PAGE_SIZE, page,
REQ_OP_WRITE | REQ_SYNC | REQ_FUA, false);
sh->log_start = ctx->pos;
list_add_tail(&sh->r5c, &log->stripe_in_journal_list);
atomic_inc(&log->stripe_in_journal_count);
ctx->pos = write_pos;
ctx->seq += 1;
next_checkpoint = sh->log_start;
}
log->next_checkpoint = next_checkpoint;
__free_page(page);
return 0;
}
static void r5c_recovery_flush_data_only_stripes(struct r5l_log *log,
struct r5l_recovery_ctx *ctx)
{
struct mddev *mddev = log->rdev->mddev;
struct r5conf *conf = mddev->private;
struct stripe_head *sh, *next;
bool cleared_pending = false;
if (ctx->data_only_stripes == 0)
return;
if (test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
cleared_pending = true;
clear_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags);
}
log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_BACK;
list_for_each_entry_safe(sh, next, &ctx->cached_list, lru) {
r5c_make_stripe_write_out(sh);
set_bit(STRIPE_HANDLE, &sh->state);
list_del_init(&sh->lru);
raid5_release_stripe(sh);
}
/* reuse conf->wait_for_quiescent in recovery */
wait_event(conf->wait_for_quiescent,
atomic_read(&conf->active_stripes) == 0);
log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
if (cleared_pending)
set_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags);
}
static int r5l_recovery_log(struct r5l_log *log)
{
struct mddev *mddev = log->rdev->mddev;
struct r5l_recovery_ctx *ctx;
int ret;
sector_t pos;
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
ctx->pos = log->last_checkpoint;
ctx->seq = log->last_cp_seq;
INIT_LIST_HEAD(&ctx->cached_list);
ctx->meta_page = alloc_page(GFP_KERNEL);
if (!ctx->meta_page) {
ret = -ENOMEM;
goto meta_page;
}
if (r5l_recovery_allocate_ra_pool(log, ctx) != 0) {
ret = -ENOMEM;
goto ra_pool;
}
ret = r5c_recovery_flush_log(log, ctx);
if (ret)
goto error;
pos = ctx->pos;
ctx->seq += 10000;
if ((ctx->data_only_stripes == 0) && (ctx->data_parity_stripes == 0))
pr_info("md/raid:%s: starting from clean shutdown\n",
mdname(mddev));
else
pr_info("md/raid:%s: recovering %d data-only stripes and %d data-parity stripes\n",
mdname(mddev), ctx->data_only_stripes,
ctx->data_parity_stripes);
if (ctx->data_only_stripes == 0) {
log->next_checkpoint = ctx->pos;
r5l_log_write_empty_meta_block(log, ctx->pos, ctx->seq++);
ctx->pos = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
} else if (r5c_recovery_rewrite_data_only_stripes(log, ctx)) {
pr_err("md/raid:%s: failed to rewrite stripes to journal\n",
mdname(mddev));
ret = -EIO;
goto error;
}
log->log_start = ctx->pos;
log->seq = ctx->seq;
log->last_checkpoint = pos;
r5l_write_super(log, pos);
r5c_recovery_flush_data_only_stripes(log, ctx);
ret = 0;
error:
r5l_recovery_free_ra_pool(log, ctx);
ra_pool:
__free_page(ctx->meta_page);
meta_page:
kfree(ctx);
return ret;
}
static void r5l_write_super(struct r5l_log *log, sector_t cp)
{
struct mddev *mddev = log->rdev->mddev;
log->rdev->journal_tail = cp;
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
}
static ssize_t r5c_journal_mode_show(struct mddev *mddev, char *page)
{
struct r5conf *conf;
int ret;
ret = mddev_lock(mddev);
if (ret)
return ret;
conf = mddev->private;
if (!conf || !conf->log)
goto out_unlock;
switch (conf->log->r5c_journal_mode) {
case R5C_JOURNAL_MODE_WRITE_THROUGH:
ret = snprintf(
page, PAGE_SIZE, "[%s] %s\n",
r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_THROUGH],
r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_BACK]);
break;
case R5C_JOURNAL_MODE_WRITE_BACK:
ret = snprintf(
page, PAGE_SIZE, "%s [%s]\n",
r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_THROUGH],
r5c_journal_mode_str[R5C_JOURNAL_MODE_WRITE_BACK]);
break;
default:
ret = 0;
}
out_unlock:
mddev_unlock(mddev);
return ret;
}
/*
* Set journal cache mode on @mddev (external API initially needed by dm-raid).
*
* @mode as defined in 'enum r5c_journal_mode'.
*
*/
int r5c_journal_mode_set(struct mddev *mddev, int mode)
{
struct r5conf *conf;
if (mode < R5C_JOURNAL_MODE_WRITE_THROUGH ||
mode > R5C_JOURNAL_MODE_WRITE_BACK)
return -EINVAL;
conf = mddev->private;
if (!conf || !conf->log)
return -ENODEV;
if (raid5_calc_degraded(conf) > 0 &&
mode == R5C_JOURNAL_MODE_WRITE_BACK)
return -EINVAL;
mddev_suspend(mddev);
conf->log->r5c_journal_mode = mode;
mddev_resume(mddev);
pr_debug("md/raid:%s: setting r5c cache mode to %d: %s\n",
mdname(mddev), mode, r5c_journal_mode_str[mode]);
return 0;
}
EXPORT_SYMBOL(r5c_journal_mode_set);
static ssize_t r5c_journal_mode_store(struct mddev *mddev,
const char *page, size_t length)
{
int mode = ARRAY_SIZE(r5c_journal_mode_str);
size_t len = length;
int ret;
if (len < 2)
return -EINVAL;
if (page[len - 1] == '\n')
len--;
while (mode--)
if (strlen(r5c_journal_mode_str[mode]) == len &&
!strncmp(page, r5c_journal_mode_str[mode], len))
break;
ret = mddev_lock(mddev);
if (ret)
return ret;
ret = r5c_journal_mode_set(mddev, mode);
mddev_unlock(mddev);
return ret ?: length;
}
struct md_sysfs_entry
r5c_journal_mode = __ATTR(journal_mode, 0644,
r5c_journal_mode_show, r5c_journal_mode_store);
/*
* Try handle write operation in caching phase. This function should only
* be called in write-back mode.
*
* If all outstanding writes can be handled in caching phase, returns 0
* If writes requires write-out phase, call r5c_make_stripe_write_out()
* and returns -EAGAIN
*/
int r5c_try_caching_write(struct r5conf *conf,
struct stripe_head *sh,
struct stripe_head_state *s,
int disks)
{
struct r5l_log *log = conf->log;
int i;
struct r5dev *dev;
int to_cache = 0;
void __rcu **pslot;
sector_t tree_index;
int ret;
uintptr_t refcount;
BUG_ON(!r5c_is_writeback(log));
if (!test_bit(STRIPE_R5C_CACHING, &sh->state)) {
/*
* There are two different scenarios here:
* 1. The stripe has some data cached, and it is sent to
* write-out phase for reclaim
* 2. The stripe is clean, and this is the first write
*
* For 1, return -EAGAIN, so we continue with
* handle_stripe_dirtying().
*
* For 2, set STRIPE_R5C_CACHING and continue with caching
* write.
*/
/* case 1: anything injournal or anything in written */
if (s->injournal > 0 || s->written > 0)
return -EAGAIN;
/* case 2 */
set_bit(STRIPE_R5C_CACHING, &sh->state);
}
/*
* When run in degraded mode, array is set to write-through mode.
* This check helps drain pending write safely in the transition to
* write-through mode.
*
* When a stripe is syncing, the write is also handled in write
* through mode.
*/
if (s->failed || test_bit(STRIPE_SYNCING, &sh->state)) {
r5c_make_stripe_write_out(sh);
return -EAGAIN;
}
for (i = disks; i--; ) {
dev = &sh->dev[i];
/* if non-overwrite, use writing-out phase */
if (dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags) &&
!test_bit(R5_InJournal, &dev->flags)) {
r5c_make_stripe_write_out(sh);
return -EAGAIN;
}
}
/* if the stripe is not counted in big_stripe_tree, add it now */
if (!test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state) &&
!test_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) {
tree_index = r5c_tree_index(conf, sh->sector);
spin_lock(&log->tree_lock);
pslot = radix_tree_lookup_slot(&log->big_stripe_tree,
tree_index);
if (pslot) {
refcount = (uintptr_t)radix_tree_deref_slot_protected(
pslot, &log->tree_lock) >>
R5C_RADIX_COUNT_SHIFT;
radix_tree_replace_slot(
&log->big_stripe_tree, pslot,
(void *)((refcount + 1) << R5C_RADIX_COUNT_SHIFT));
} else {
/*
* this radix_tree_insert can fail safely, so no
* need to call radix_tree_preload()
*/
ret = radix_tree_insert(
&log->big_stripe_tree, tree_index,
(void *)(1 << R5C_RADIX_COUNT_SHIFT));
if (ret) {
spin_unlock(&log->tree_lock);
r5c_make_stripe_write_out(sh);
return -EAGAIN;
}
}
spin_unlock(&log->tree_lock);
/*
* set STRIPE_R5C_PARTIAL_STRIPE, this shows the stripe is
* counted in the radix tree
*/
set_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state);
atomic_inc(&conf->r5c_cached_partial_stripes);
}
for (i = disks; i--; ) {
dev = &sh->dev[i];
if (dev->towrite) {
set_bit(R5_Wantwrite, &dev->flags);
set_bit(R5_Wantdrain, &dev->flags);
set_bit(R5_LOCKED, &dev->flags);
to_cache++;
}
}
if (to_cache) {
set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
/*
* set STRIPE_LOG_TRAPPED, which triggers r5c_cache_data()
* in ops_run_io(). STRIPE_LOG_TRAPPED will be cleared in
* r5c_handle_data_cached()
*/
set_bit(STRIPE_LOG_TRAPPED, &sh->state);
}
return 0;
}
/*
* free extra pages (orig_page) we allocated for prexor
*/
void r5c_release_extra_page(struct stripe_head *sh)
{
struct r5conf *conf = sh->raid_conf;
int i;
bool using_disk_info_extra_page;
using_disk_info_extra_page =
sh->dev[0].orig_page == conf->disks[0].extra_page;
for (i = sh->disks; i--; )
if (sh->dev[i].page != sh->dev[i].orig_page) {
struct page *p = sh->dev[i].orig_page;
sh->dev[i].orig_page = sh->dev[i].page;
clear_bit(R5_OrigPageUPTDODATE, &sh->dev[i].flags);
if (!using_disk_info_extra_page)
put_page(p);
}
if (using_disk_info_extra_page) {
clear_bit(R5C_EXTRA_PAGE_IN_USE, &conf->cache_state);
md_wakeup_thread(conf->mddev->thread);
}
}
void r5c_use_extra_page(struct stripe_head *sh)
{
struct r5conf *conf = sh->raid_conf;
int i;
struct r5dev *dev;
for (i = sh->disks; i--; ) {
dev = &sh->dev[i];
if (dev->orig_page != dev->page)
put_page(dev->orig_page);
dev->orig_page = conf->disks[i].extra_page;
}
}
/*
* clean up the stripe (clear R5_InJournal for dev[pd_idx] etc.) after the
* stripe is committed to RAID disks.
*/
void r5c_finish_stripe_write_out(struct r5conf *conf,
struct stripe_head *sh,
struct stripe_head_state *s)
{
struct r5l_log *log = conf->log;
int i;
int do_wakeup = 0;
sector_t tree_index;
void __rcu **pslot;
uintptr_t refcount;
if (!log || !test_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags))
return;
WARN_ON(test_bit(STRIPE_R5C_CACHING, &sh->state));
clear_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags);
if (log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_THROUGH)
return;
for (i = sh->disks; i--; ) {
clear_bit(R5_InJournal, &sh->dev[i].flags);
if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
do_wakeup = 1;
}
/*
* analyse_stripe() runs before r5c_finish_stripe_write_out(),
* We updated R5_InJournal, so we also update s->injournal.
*/
s->injournal = 0;
if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
if (atomic_dec_and_test(&conf->pending_full_writes))
md_wakeup_thread(conf->mddev->thread);
if (do_wakeup)
wake_up(&conf->wait_for_overlap);
spin_lock_irq(&log->stripe_in_journal_lock);
list_del_init(&sh->r5c);
spin_unlock_irq(&log->stripe_in_journal_lock);
sh->log_start = MaxSector;
atomic_dec(&log->stripe_in_journal_count);
r5c_update_log_state(log);
/* stop counting this stripe in big_stripe_tree */
if (test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state) ||
test_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) {
tree_index = r5c_tree_index(conf, sh->sector);
spin_lock(&log->tree_lock);
pslot = radix_tree_lookup_slot(&log->big_stripe_tree,
tree_index);
BUG_ON(pslot == NULL);
refcount = (uintptr_t)radix_tree_deref_slot_protected(
pslot, &log->tree_lock) >>
R5C_RADIX_COUNT_SHIFT;
if (refcount == 1)
radix_tree_delete(&log->big_stripe_tree, tree_index);
else
radix_tree_replace_slot(
&log->big_stripe_tree, pslot,
(void *)((refcount - 1) << R5C_RADIX_COUNT_SHIFT));
spin_unlock(&log->tree_lock);
}
if (test_and_clear_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state)) {
BUG_ON(atomic_read(&conf->r5c_cached_partial_stripes) == 0);
atomic_dec(&conf->r5c_flushing_partial_stripes);
atomic_dec(&conf->r5c_cached_partial_stripes);
}
if (test_and_clear_bit(STRIPE_R5C_FULL_STRIPE, &sh->state)) {
BUG_ON(atomic_read(&conf->r5c_cached_full_stripes) == 0);
atomic_dec(&conf->r5c_flushing_full_stripes);
atomic_dec(&conf->r5c_cached_full_stripes);
}
r5l_append_flush_payload(log, sh->sector);
/* stripe is flused to raid disks, we can do resync now */
if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state))
set_bit(STRIPE_HANDLE, &sh->state);
}
int r5c_cache_data(struct r5l_log *log, struct stripe_head *sh)
{
struct r5conf *conf = sh->raid_conf;
int pages = 0;
int reserve;
int i;
int ret = 0;
BUG_ON(!log);
for (i = 0; i < sh->disks; i++) {
void *addr;
if (!test_bit(R5_Wantwrite, &sh->dev[i].flags))
continue;
addr = kmap_atomic(sh->dev[i].page);
sh->dev[i].log_checksum = crc32c_le(log->uuid_checksum,
addr, PAGE_SIZE);
kunmap_atomic(addr);
pages++;
}
WARN_ON(pages == 0);
/*
* The stripe must enter state machine again to call endio, so
* don't delay.
*/
clear_bit(STRIPE_DELAYED, &sh->state);
atomic_inc(&sh->count);
mutex_lock(&log->io_mutex);
/* meta + data */
reserve = (1 + pages) << (PAGE_SHIFT - 9);
if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state) &&
sh->log_start == MaxSector)
r5l_add_no_space_stripe(log, sh);
else if (!r5l_has_free_space(log, reserve)) {
if (sh->log_start == log->last_checkpoint)
BUG();
else
r5l_add_no_space_stripe(log, sh);
} else {
ret = r5l_log_stripe(log, sh, pages, 0);
if (ret) {
spin_lock_irq(&log->io_list_lock);
list_add_tail(&sh->log_list, &log->no_mem_stripes);
spin_unlock_irq(&log->io_list_lock);
}
}
mutex_unlock(&log->io_mutex);
return 0;
}
/* check whether this big stripe is in write back cache. */
bool r5c_big_stripe_cached(struct r5conf *conf, sector_t sect)
{
struct r5l_log *log = conf->log;
sector_t tree_index;
void *slot;
if (!log)
return false;
WARN_ON_ONCE(!rcu_read_lock_held());
tree_index = r5c_tree_index(conf, sect);
slot = radix_tree_lookup(&log->big_stripe_tree, tree_index);
return slot != NULL;
}
static int r5l_load_log(struct r5l_log *log)
{
struct md_rdev *rdev = log->rdev;
struct page *page;
struct r5l_meta_block *mb;
sector_t cp = log->rdev->journal_tail;
u32 stored_crc, expected_crc;
bool create_super = false;
int ret = 0;
/* Make sure it's valid */
if (cp >= rdev->sectors || round_down(cp, BLOCK_SECTORS) != cp)
cp = 0;
page = alloc_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
if (!sync_page_io(rdev, cp, PAGE_SIZE, page, REQ_OP_READ, false)) {
ret = -EIO;
goto ioerr;
}
mb = page_address(page);
if (le32_to_cpu(mb->magic) != R5LOG_MAGIC ||
mb->version != R5LOG_VERSION) {
create_super = true;
goto create;
}
stored_crc = le32_to_cpu(mb->checksum);
mb->checksum = 0;
expected_crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
if (stored_crc != expected_crc) {
create_super = true;
goto create;
}
if (le64_to_cpu(mb->position) != cp) {
create_super = true;
goto create;
}
create:
if (create_super) {
log->last_cp_seq = get_random_u32();
cp = 0;
r5l_log_write_empty_meta_block(log, cp, log->last_cp_seq);
/*
* Make sure super points to correct address. Log might have
* data very soon. If super hasn't correct log tail address,
* recovery can't find the log
*/
r5l_write_super(log, cp);
} else
log->last_cp_seq = le64_to_cpu(mb->seq);
log->device_size = round_down(rdev->sectors, BLOCK_SECTORS);
log->max_free_space = log->device_size >> RECLAIM_MAX_FREE_SPACE_SHIFT;
if (log->max_free_space > RECLAIM_MAX_FREE_SPACE)
log->max_free_space = RECLAIM_MAX_FREE_SPACE;
log->last_checkpoint = cp;
__free_page(page);
if (create_super) {
log->log_start = r5l_ring_add(log, cp, BLOCK_SECTORS);
log->seq = log->last_cp_seq + 1;
log->next_checkpoint = cp;
} else
ret = r5l_recovery_log(log);
r5c_update_log_state(log);
return ret;
ioerr:
__free_page(page);
return ret;
}
int r5l_start(struct r5l_log *log)
{
int ret;
if (!log)
return 0;
ret = r5l_load_log(log);
if (ret) {
struct mddev *mddev = log->rdev->mddev;
struct r5conf *conf = mddev->private;
r5l_exit_log(conf);
}
return ret;
}
void r5c_update_on_rdev_error(struct mddev *mddev, struct md_rdev *rdev)
{
struct r5conf *conf = mddev->private;
struct r5l_log *log = conf->log;
if (!log)
return;
if ((raid5_calc_degraded(conf) > 0 ||
test_bit(Journal, &rdev->flags)) &&
conf->log->r5c_journal_mode == R5C_JOURNAL_MODE_WRITE_BACK)
schedule_work(&log->disable_writeback_work);
}
int r5l_init_log(struct r5conf *conf, struct md_rdev *rdev)
{
struct r5l_log *log;
struct md_thread *thread;
int ret;
pr_debug("md/raid:%s: using device %pg as journal\n",
mdname(conf->mddev), rdev->bdev);
if (PAGE_SIZE != 4096)
return -EINVAL;
/*
* The PAGE_SIZE must be big enough to hold 1 r5l_meta_block and
* raid_disks r5l_payload_data_parity.
*
* Write journal and cache does not work for very big array
* (raid_disks > 203)
*/
if (sizeof(struct r5l_meta_block) +
((sizeof(struct r5l_payload_data_parity) + sizeof(__le32)) *
conf->raid_disks) > PAGE_SIZE) {
pr_err("md/raid:%s: write journal/cache doesn't work for array with %d disks\n",
mdname(conf->mddev), conf->raid_disks);
return -EINVAL;
}
log = kzalloc(sizeof(*log), GFP_KERNEL);
if (!log)
return -ENOMEM;
log->rdev = rdev;
log->need_cache_flush = bdev_write_cache(rdev->bdev);
log->uuid_checksum = crc32c_le(~0, rdev->mddev->uuid,
sizeof(rdev->mddev->uuid));
mutex_init(&log->io_mutex);
spin_lock_init(&log->io_list_lock);
INIT_LIST_HEAD(&log->running_ios);
INIT_LIST_HEAD(&log->io_end_ios);
INIT_LIST_HEAD(&log->flushing_ios);
INIT_LIST_HEAD(&log->finished_ios);
log->io_kc = KMEM_CACHE(r5l_io_unit, 0);
if (!log->io_kc)
goto io_kc;
ret = mempool_init_slab_pool(&log->io_pool, R5L_POOL_SIZE, log->io_kc);
if (ret)
goto io_pool;
ret = bioset_init(&log->bs, R5L_POOL_SIZE, 0, BIOSET_NEED_BVECS);
if (ret)
goto io_bs;
ret = mempool_init_page_pool(&log->meta_pool, R5L_POOL_SIZE, 0);
if (ret)
goto out_mempool;
spin_lock_init(&log->tree_lock);
INIT_RADIX_TREE(&log->big_stripe_tree, GFP_NOWAIT | __GFP_NOWARN);
thread = md_register_thread(r5l_reclaim_thread, log->rdev->mddev,
"reclaim");
if (!thread)
goto reclaim_thread;
thread->timeout = R5C_RECLAIM_WAKEUP_INTERVAL;
rcu_assign_pointer(log->reclaim_thread, thread);
init_waitqueue_head(&log->iounit_wait);
INIT_LIST_HEAD(&log->no_mem_stripes);
INIT_LIST_HEAD(&log->no_space_stripes);
spin_lock_init(&log->no_space_stripes_lock);
INIT_WORK(&log->deferred_io_work, r5l_submit_io_async);
INIT_WORK(&log->disable_writeback_work, r5c_disable_writeback_async);
log->r5c_journal_mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
INIT_LIST_HEAD(&log->stripe_in_journal_list);
spin_lock_init(&log->stripe_in_journal_lock);
atomic_set(&log->stripe_in_journal_count, 0);
conf->log = log;
set_bit(MD_HAS_JOURNAL, &conf->mddev->flags);
return 0;
reclaim_thread:
mempool_exit(&log->meta_pool);
out_mempool:
bioset_exit(&log->bs);
io_bs:
mempool_exit(&log->io_pool);
io_pool:
kmem_cache_destroy(log->io_kc);
io_kc:
kfree(log);
return -EINVAL;
}
void r5l_exit_log(struct r5conf *conf)
{
struct r5l_log *log = conf->log;
md_unregister_thread(conf->mddev, &log->reclaim_thread);
/*
* 'reconfig_mutex' is held by caller, set 'confg->log' to NULL to
* ensure disable_writeback_work wakes up and exits.
*/
conf->log = NULL;
wake_up(&conf->mddev->sb_wait);
flush_work(&log->disable_writeback_work);
mempool_exit(&log->meta_pool);
bioset_exit(&log->bs);
mempool_exit(&log->io_pool);
kmem_cache_destroy(log->io_kc);
kfree(log);
}
| linux-master | drivers/md/raid5-cache.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2021 Microsoft Corporation
*
* Author: Tushar Sugandhi <[email protected]>
*
* Enables IMA measurements for DM targets
*/
#include "dm-core.h"
#include "dm-ima.h"
#include <linux/ima.h>
#include <linux/sched/mm.h>
#include <crypto/hash.h>
#include <linux/crypto.h>
#include <crypto/hash_info.h>
#define DM_MSG_PREFIX "ima"
/*
* Internal function to prefix separator characters in input buffer with escape
* character, so that they don't interfere with the construction of key-value pairs,
* and clients can split the key1=val1,key2=val2,key3=val3; pairs properly.
*/
static void fix_separator_chars(char **buf)
{
int l = strlen(*buf);
int i, j, sp = 0;
for (i = 0; i < l; i++)
if ((*buf)[i] == '\\' || (*buf)[i] == ';' || (*buf)[i] == '=' || (*buf)[i] == ',')
sp++;
if (!sp)
return;
for (i = l-1, j = i+sp; i >= 0; i--) {
(*buf)[j--] = (*buf)[i];
if ((*buf)[i] == '\\' || (*buf)[i] == ';' || (*buf)[i] == '=' || (*buf)[i] == ',')
(*buf)[j--] = '\\';
}
}
/*
* Internal function to allocate memory for IMA measurements.
*/
static void *dm_ima_alloc(size_t len, gfp_t flags, bool noio)
{
unsigned int noio_flag;
void *ptr;
if (noio)
noio_flag = memalloc_noio_save();
ptr = kzalloc(len, flags);
if (noio)
memalloc_noio_restore(noio_flag);
return ptr;
}
/*
* Internal function to allocate and copy name and uuid for IMA measurements.
*/
static int dm_ima_alloc_and_copy_name_uuid(struct mapped_device *md, char **dev_name,
char **dev_uuid, bool noio)
{
int r;
*dev_name = dm_ima_alloc(DM_NAME_LEN*2, GFP_KERNEL, noio);
if (!(*dev_name)) {
r = -ENOMEM;
goto error;
}
*dev_uuid = dm_ima_alloc(DM_UUID_LEN*2, GFP_KERNEL, noio);
if (!(*dev_uuid)) {
r = -ENOMEM;
goto error;
}
r = dm_copy_name_and_uuid(md, *dev_name, *dev_uuid);
if (r)
goto error;
fix_separator_chars(dev_name);
fix_separator_chars(dev_uuid);
return 0;
error:
kfree(*dev_name);
kfree(*dev_uuid);
*dev_name = NULL;
*dev_uuid = NULL;
return r;
}
/*
* Internal function to allocate and copy device data for IMA measurements.
*/
static int dm_ima_alloc_and_copy_device_data(struct mapped_device *md, char **device_data,
unsigned int num_targets, bool noio)
{
char *dev_name = NULL, *dev_uuid = NULL;
int r;
r = dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio);
if (r)
return r;
*device_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN, GFP_KERNEL, noio);
if (!(*device_data)) {
r = -ENOMEM;
goto error;
}
scnprintf(*device_data, DM_IMA_DEVICE_BUF_LEN,
"name=%s,uuid=%s,major=%d,minor=%d,minor_count=%d,num_targets=%u;",
dev_name, dev_uuid, md->disk->major, md->disk->first_minor,
md->disk->minors, num_targets);
error:
kfree(dev_name);
kfree(dev_uuid);
return r;
}
/*
* Internal wrapper function to call IMA to measure DM data.
*/
static void dm_ima_measure_data(const char *event_name, const void *buf, size_t buf_len,
bool noio)
{
unsigned int noio_flag;
if (noio)
noio_flag = memalloc_noio_save();
ima_measure_critical_data(DM_NAME, event_name, buf, buf_len,
false, NULL, 0);
if (noio)
memalloc_noio_restore(noio_flag);
}
/*
* Internal function to allocate and copy current device capacity for IMA measurements.
*/
static int dm_ima_alloc_and_copy_capacity_str(struct mapped_device *md, char **capacity_str,
bool noio)
{
sector_t capacity;
capacity = get_capacity(md->disk);
*capacity_str = dm_ima_alloc(DM_IMA_DEVICE_CAPACITY_BUF_LEN, GFP_KERNEL, noio);
if (!(*capacity_str))
return -ENOMEM;
scnprintf(*capacity_str, DM_IMA_DEVICE_BUF_LEN, "current_device_capacity=%llu;",
capacity);
return 0;
}
/*
* Initialize/reset the dm ima related data structure variables.
*/
void dm_ima_reset_data(struct mapped_device *md)
{
memset(&(md->ima), 0, sizeof(md->ima));
md->ima.dm_version_str_len = strlen(DM_IMA_VERSION_STR);
}
/*
* Build up the IMA data for each target, and finally measure.
*/
void dm_ima_measure_on_table_load(struct dm_table *table, unsigned int status_flags)
{
size_t device_data_buf_len, target_metadata_buf_len, target_data_buf_len, l = 0;
char *target_metadata_buf = NULL, *target_data_buf = NULL, *digest_buf = NULL;
char *ima_buf = NULL, *device_data_buf = NULL;
int digest_size, last_target_measured = -1, r;
status_type_t type = STATUSTYPE_IMA;
size_t cur_total_buf_len = 0;
unsigned int num_targets, i;
SHASH_DESC_ON_STACK(shash, NULL);
struct crypto_shash *tfm = NULL;
u8 *digest = NULL;
bool noio = false;
/*
* In below hash_alg_prefix_len assignment +1 is for the additional char (':'),
* when prefixing the hash value with the hash algorithm name. e.g. sha256:<hash_value>.
*/
const size_t hash_alg_prefix_len = strlen(DM_IMA_TABLE_HASH_ALG) + 1;
char table_load_event_name[] = "dm_table_load";
ima_buf = dm_ima_alloc(DM_IMA_MEASUREMENT_BUF_LEN, GFP_KERNEL, noio);
if (!ima_buf)
return;
target_metadata_buf = dm_ima_alloc(DM_IMA_TARGET_METADATA_BUF_LEN, GFP_KERNEL, noio);
if (!target_metadata_buf)
goto error;
target_data_buf = dm_ima_alloc(DM_IMA_TARGET_DATA_BUF_LEN, GFP_KERNEL, noio);
if (!target_data_buf)
goto error;
num_targets = table->num_targets;
if (dm_ima_alloc_and_copy_device_data(table->md, &device_data_buf, num_targets, noio))
goto error;
tfm = crypto_alloc_shash(DM_IMA_TABLE_HASH_ALG, 0, 0);
if (IS_ERR(tfm))
goto error;
shash->tfm = tfm;
digest_size = crypto_shash_digestsize(tfm);
digest = dm_ima_alloc(digest_size, GFP_KERNEL, noio);
if (!digest)
goto error;
r = crypto_shash_init(shash);
if (r)
goto error;
memcpy(ima_buf + l, DM_IMA_VERSION_STR, table->md->ima.dm_version_str_len);
l += table->md->ima.dm_version_str_len;
device_data_buf_len = strlen(device_data_buf);
memcpy(ima_buf + l, device_data_buf, device_data_buf_len);
l += device_data_buf_len;
for (i = 0; i < num_targets; i++) {
struct dm_target *ti = dm_table_get_target(table, i);
last_target_measured = 0;
/*
* First retrieve the target metadata.
*/
scnprintf(target_metadata_buf, DM_IMA_TARGET_METADATA_BUF_LEN,
"target_index=%d,target_begin=%llu,target_len=%llu,",
i, ti->begin, ti->len);
target_metadata_buf_len = strlen(target_metadata_buf);
/*
* Then retrieve the actual target data.
*/
if (ti->type->status)
ti->type->status(ti, type, status_flags, target_data_buf,
DM_IMA_TARGET_DATA_BUF_LEN);
else
target_data_buf[0] = '\0';
target_data_buf_len = strlen(target_data_buf);
/*
* Check if the total data can fit into the IMA buffer.
*/
cur_total_buf_len = l + target_metadata_buf_len + target_data_buf_len;
/*
* IMA measurements for DM targets are best-effort.
* If the total data buffered so far, including the current target,
* is too large to fit into DM_IMA_MEASUREMENT_BUF_LEN, measure what
* we have in the current buffer, and continue measuring the remaining
* targets by prefixing the device metadata again.
*/
if (unlikely(cur_total_buf_len >= DM_IMA_MEASUREMENT_BUF_LEN)) {
dm_ima_measure_data(table_load_event_name, ima_buf, l, noio);
r = crypto_shash_update(shash, (const u8 *)ima_buf, l);
if (r < 0)
goto error;
memset(ima_buf, 0, DM_IMA_MEASUREMENT_BUF_LEN);
l = 0;
/*
* Each new "dm_table_load" entry in IMA log should have device data
* prefix, so that multiple records from the same "dm_table_load" for
* a given device can be linked together.
*/
memcpy(ima_buf + l, DM_IMA_VERSION_STR, table->md->ima.dm_version_str_len);
l += table->md->ima.dm_version_str_len;
memcpy(ima_buf + l, device_data_buf, device_data_buf_len);
l += device_data_buf_len;
/*
* If this iteration of the for loop turns out to be the last target
* in the table, dm_ima_measure_data("dm_table_load", ...) doesn't need
* to be called again, just the hash needs to be finalized.
* "last_target_measured" tracks this state.
*/
last_target_measured = 1;
}
/*
* Fill-in all the target metadata, so that multiple targets for the same
* device can be linked together.
*/
memcpy(ima_buf + l, target_metadata_buf, target_metadata_buf_len);
l += target_metadata_buf_len;
memcpy(ima_buf + l, target_data_buf, target_data_buf_len);
l += target_data_buf_len;
}
if (!last_target_measured) {
dm_ima_measure_data(table_load_event_name, ima_buf, l, noio);
r = crypto_shash_update(shash, (const u8 *)ima_buf, l);
if (r < 0)
goto error;
}
/*
* Finalize the table hash, and store it in table->md->ima.inactive_table.hash,
* so that the table data can be verified against the future device state change
* events, e.g. resume, rename, remove, table-clear etc.
*/
r = crypto_shash_final(shash, digest);
if (r < 0)
goto error;
digest_buf = dm_ima_alloc((digest_size*2) + hash_alg_prefix_len + 1, GFP_KERNEL, noio);
if (!digest_buf)
goto error;
snprintf(digest_buf, hash_alg_prefix_len + 1, "%s:", DM_IMA_TABLE_HASH_ALG);
for (i = 0; i < digest_size; i++)
snprintf((digest_buf + hash_alg_prefix_len + (i*2)), 3, "%02x", digest[i]);
if (table->md->ima.active_table.hash != table->md->ima.inactive_table.hash)
kfree(table->md->ima.inactive_table.hash);
table->md->ima.inactive_table.hash = digest_buf;
table->md->ima.inactive_table.hash_len = strlen(digest_buf);
table->md->ima.inactive_table.num_targets = num_targets;
if (table->md->ima.active_table.device_metadata !=
table->md->ima.inactive_table.device_metadata)
kfree(table->md->ima.inactive_table.device_metadata);
table->md->ima.inactive_table.device_metadata = device_data_buf;
table->md->ima.inactive_table.device_metadata_len = device_data_buf_len;
goto exit;
error:
kfree(digest_buf);
kfree(device_data_buf);
exit:
kfree(digest);
if (tfm)
crypto_free_shash(tfm);
kfree(ima_buf);
kfree(target_metadata_buf);
kfree(target_data_buf);
}
/*
* Measure IMA data on device resume.
*/
void dm_ima_measure_on_device_resume(struct mapped_device *md, bool swap)
{
char *device_table_data, *dev_name = NULL, *dev_uuid = NULL, *capacity_str = NULL;
char active[] = "active_table_hash=";
unsigned int active_len = strlen(active), capacity_len = 0;
unsigned int l = 0;
bool noio = true;
bool nodata = true;
int r;
device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN, GFP_KERNEL, noio);
if (!device_table_data)
return;
r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio);
if (r)
goto error;
memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len);
l += md->ima.dm_version_str_len;
if (swap) {
if (md->ima.active_table.hash != md->ima.inactive_table.hash)
kfree(md->ima.active_table.hash);
md->ima.active_table.hash = NULL;
md->ima.active_table.hash_len = 0;
if (md->ima.active_table.device_metadata !=
md->ima.inactive_table.device_metadata)
kfree(md->ima.active_table.device_metadata);
md->ima.active_table.device_metadata = NULL;
md->ima.active_table.device_metadata_len = 0;
md->ima.active_table.num_targets = 0;
if (md->ima.inactive_table.hash) {
md->ima.active_table.hash = md->ima.inactive_table.hash;
md->ima.active_table.hash_len = md->ima.inactive_table.hash_len;
md->ima.inactive_table.hash = NULL;
md->ima.inactive_table.hash_len = 0;
}
if (md->ima.inactive_table.device_metadata) {
md->ima.active_table.device_metadata =
md->ima.inactive_table.device_metadata;
md->ima.active_table.device_metadata_len =
md->ima.inactive_table.device_metadata_len;
md->ima.active_table.num_targets = md->ima.inactive_table.num_targets;
md->ima.inactive_table.device_metadata = NULL;
md->ima.inactive_table.device_metadata_len = 0;
md->ima.inactive_table.num_targets = 0;
}
}
if (md->ima.active_table.device_metadata) {
memcpy(device_table_data + l, md->ima.active_table.device_metadata,
md->ima.active_table.device_metadata_len);
l += md->ima.active_table.device_metadata_len;
nodata = false;
}
if (md->ima.active_table.hash) {
memcpy(device_table_data + l, active, active_len);
l += active_len;
memcpy(device_table_data + l, md->ima.active_table.hash,
md->ima.active_table.hash_len);
l += md->ima.active_table.hash_len;
memcpy(device_table_data + l, ";", 1);
l++;
nodata = false;
}
if (nodata) {
r = dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio);
if (r)
goto error;
scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN,
"%sname=%s,uuid=%s;device_resume=no_data;",
DM_IMA_VERSION_STR, dev_name, dev_uuid);
l = strlen(device_table_data);
}
capacity_len = strlen(capacity_str);
memcpy(device_table_data + l, capacity_str, capacity_len);
l += capacity_len;
dm_ima_measure_data("dm_device_resume", device_table_data, l, noio);
kfree(dev_name);
kfree(dev_uuid);
error:
kfree(capacity_str);
kfree(device_table_data);
}
/*
* Measure IMA data on remove.
*/
void dm_ima_measure_on_device_remove(struct mapped_device *md, bool remove_all)
{
char *device_table_data, *dev_name = NULL, *dev_uuid = NULL, *capacity_str = NULL;
char active_table_str[] = "active_table_hash=";
char inactive_table_str[] = "inactive_table_hash=";
char device_active_str[] = "device_active_metadata=";
char device_inactive_str[] = "device_inactive_metadata=";
char remove_all_str[] = "remove_all=";
unsigned int active_table_len = strlen(active_table_str);
unsigned int inactive_table_len = strlen(inactive_table_str);
unsigned int device_active_len = strlen(device_active_str);
unsigned int device_inactive_len = strlen(device_inactive_str);
unsigned int remove_all_len = strlen(remove_all_str);
unsigned int capacity_len = 0;
unsigned int l = 0;
bool noio = true;
bool nodata = true;
int r;
device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN*2, GFP_KERNEL, noio);
if (!device_table_data)
goto exit;
r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio);
if (r) {
kfree(device_table_data);
goto exit;
}
memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len);
l += md->ima.dm_version_str_len;
if (md->ima.active_table.device_metadata) {
memcpy(device_table_data + l, device_active_str, device_active_len);
l += device_active_len;
memcpy(device_table_data + l, md->ima.active_table.device_metadata,
md->ima.active_table.device_metadata_len);
l += md->ima.active_table.device_metadata_len;
nodata = false;
}
if (md->ima.inactive_table.device_metadata) {
memcpy(device_table_data + l, device_inactive_str, device_inactive_len);
l += device_inactive_len;
memcpy(device_table_data + l, md->ima.inactive_table.device_metadata,
md->ima.inactive_table.device_metadata_len);
l += md->ima.inactive_table.device_metadata_len;
nodata = false;
}
if (md->ima.active_table.hash) {
memcpy(device_table_data + l, active_table_str, active_table_len);
l += active_table_len;
memcpy(device_table_data + l, md->ima.active_table.hash,
md->ima.active_table.hash_len);
l += md->ima.active_table.hash_len;
memcpy(device_table_data + l, ",", 1);
l++;
nodata = false;
}
if (md->ima.inactive_table.hash) {
memcpy(device_table_data + l, inactive_table_str, inactive_table_len);
l += inactive_table_len;
memcpy(device_table_data + l, md->ima.inactive_table.hash,
md->ima.inactive_table.hash_len);
l += md->ima.inactive_table.hash_len;
memcpy(device_table_data + l, ",", 1);
l++;
nodata = false;
}
/*
* In case both active and inactive tables, and corresponding
* device metadata is cleared/missing - record the name and uuid
* in IMA measurements.
*/
if (nodata) {
if (dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio))
goto error;
scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN,
"%sname=%s,uuid=%s;device_remove=no_data;",
DM_IMA_VERSION_STR, dev_name, dev_uuid);
l = strlen(device_table_data);
}
memcpy(device_table_data + l, remove_all_str, remove_all_len);
l += remove_all_len;
memcpy(device_table_data + l, remove_all ? "y;" : "n;", 2);
l += 2;
capacity_len = strlen(capacity_str);
memcpy(device_table_data + l, capacity_str, capacity_len);
l += capacity_len;
dm_ima_measure_data("dm_device_remove", device_table_data, l, noio);
error:
kfree(device_table_data);
kfree(capacity_str);
exit:
kfree(md->ima.active_table.device_metadata);
if (md->ima.active_table.device_metadata !=
md->ima.inactive_table.device_metadata)
kfree(md->ima.inactive_table.device_metadata);
kfree(md->ima.active_table.hash);
if (md->ima.active_table.hash != md->ima.inactive_table.hash)
kfree(md->ima.inactive_table.hash);
dm_ima_reset_data(md);
kfree(dev_name);
kfree(dev_uuid);
}
/*
* Measure ima data on table clear.
*/
void dm_ima_measure_on_table_clear(struct mapped_device *md, bool new_map)
{
unsigned int l = 0, capacity_len = 0;
char *device_table_data = NULL, *dev_name = NULL, *dev_uuid = NULL, *capacity_str = NULL;
char inactive_str[] = "inactive_table_hash=";
unsigned int inactive_len = strlen(inactive_str);
bool noio = true;
bool nodata = true;
int r;
device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN, GFP_KERNEL, noio);
if (!device_table_data)
return;
r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio);
if (r)
goto error1;
memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len);
l += md->ima.dm_version_str_len;
if (md->ima.inactive_table.device_metadata_len &&
md->ima.inactive_table.hash_len) {
memcpy(device_table_data + l, md->ima.inactive_table.device_metadata,
md->ima.inactive_table.device_metadata_len);
l += md->ima.inactive_table.device_metadata_len;
memcpy(device_table_data + l, inactive_str, inactive_len);
l += inactive_len;
memcpy(device_table_data + l, md->ima.inactive_table.hash,
md->ima.inactive_table.hash_len);
l += md->ima.inactive_table.hash_len;
memcpy(device_table_data + l, ";", 1);
l++;
nodata = false;
}
if (nodata) {
if (dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio))
goto error2;
scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN,
"%sname=%s,uuid=%s;table_clear=no_data;",
DM_IMA_VERSION_STR, dev_name, dev_uuid);
l = strlen(device_table_data);
}
capacity_len = strlen(capacity_str);
memcpy(device_table_data + l, capacity_str, capacity_len);
l += capacity_len;
dm_ima_measure_data("dm_table_clear", device_table_data, l, noio);
if (new_map) {
if (md->ima.inactive_table.hash &&
md->ima.inactive_table.hash != md->ima.active_table.hash)
kfree(md->ima.inactive_table.hash);
md->ima.inactive_table.hash = NULL;
md->ima.inactive_table.hash_len = 0;
if (md->ima.inactive_table.device_metadata &&
md->ima.inactive_table.device_metadata != md->ima.active_table.device_metadata)
kfree(md->ima.inactive_table.device_metadata);
md->ima.inactive_table.device_metadata = NULL;
md->ima.inactive_table.device_metadata_len = 0;
md->ima.inactive_table.num_targets = 0;
if (md->ima.active_table.hash) {
md->ima.inactive_table.hash = md->ima.active_table.hash;
md->ima.inactive_table.hash_len = md->ima.active_table.hash_len;
}
if (md->ima.active_table.device_metadata) {
md->ima.inactive_table.device_metadata =
md->ima.active_table.device_metadata;
md->ima.inactive_table.device_metadata_len =
md->ima.active_table.device_metadata_len;
md->ima.inactive_table.num_targets =
md->ima.active_table.num_targets;
}
}
kfree(dev_name);
kfree(dev_uuid);
error2:
kfree(capacity_str);
error1:
kfree(device_table_data);
}
/*
* Measure IMA data on device rename.
*/
void dm_ima_measure_on_device_rename(struct mapped_device *md)
{
char *old_device_data = NULL, *new_device_data = NULL, *combined_device_data = NULL;
char *new_dev_name = NULL, *new_dev_uuid = NULL, *capacity_str = NULL;
bool noio = true;
int r;
if (dm_ima_alloc_and_copy_device_data(md, &new_device_data,
md->ima.active_table.num_targets, noio))
return;
if (dm_ima_alloc_and_copy_name_uuid(md, &new_dev_name, &new_dev_uuid, noio))
goto error;
combined_device_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN * 2, GFP_KERNEL, noio);
if (!combined_device_data)
goto error;
r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio);
if (r)
goto error;
old_device_data = md->ima.active_table.device_metadata;
md->ima.active_table.device_metadata = new_device_data;
md->ima.active_table.device_metadata_len = strlen(new_device_data);
scnprintf(combined_device_data, DM_IMA_DEVICE_BUF_LEN * 2,
"%s%snew_name=%s,new_uuid=%s;%s", DM_IMA_VERSION_STR, old_device_data,
new_dev_name, new_dev_uuid, capacity_str);
dm_ima_measure_data("dm_device_rename", combined_device_data, strlen(combined_device_data),
noio);
goto exit;
error:
kfree(new_device_data);
exit:
kfree(capacity_str);
kfree(combined_device_data);
kfree(old_device_data);
kfree(new_dev_name);
kfree(new_dev_uuid);
}
| linux-master | drivers/md/dm-ima.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2003 Sistina Software Limited.
* Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
#include <linux/device-mapper.h>
#include "dm-rq.h"
#include "dm-bio-record.h"
#include "dm-path-selector.h"
#include "dm-uevent.h"
#include <linux/blkdev.h>
#include <linux/ctype.h>
#include <linux/init.h>
#include <linux/mempool.h>
#include <linux/module.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <linux/delay.h>
#include <scsi/scsi_dh.h>
#include <linux/atomic.h>
#include <linux/blk-mq.h>
static struct workqueue_struct *dm_mpath_wq;
#define DM_MSG_PREFIX "multipath"
#define DM_PG_INIT_DELAY_MSECS 2000
#define DM_PG_INIT_DELAY_DEFAULT ((unsigned int) -1)
#define QUEUE_IF_NO_PATH_TIMEOUT_DEFAULT 0
static unsigned long queue_if_no_path_timeout_secs = QUEUE_IF_NO_PATH_TIMEOUT_DEFAULT;
/* Path properties */
struct pgpath {
struct list_head list;
struct priority_group *pg; /* Owning PG */
unsigned int fail_count; /* Cumulative failure count */
struct dm_path path;
struct delayed_work activate_path;
bool is_active:1; /* Path status */
};
#define path_to_pgpath(__pgp) container_of((__pgp), struct pgpath, path)
/*
* Paths are grouped into Priority Groups and numbered from 1 upwards.
* Each has a path selector which controls which path gets used.
*/
struct priority_group {
struct list_head list;
struct multipath *m; /* Owning multipath instance */
struct path_selector ps;
unsigned int pg_num; /* Reference number */
unsigned int nr_pgpaths; /* Number of paths in PG */
struct list_head pgpaths;
bool bypassed:1; /* Temporarily bypass this PG? */
};
/* Multipath context */
struct multipath {
unsigned long flags; /* Multipath state flags */
spinlock_t lock;
enum dm_queue_mode queue_mode;
struct pgpath *current_pgpath;
struct priority_group *current_pg;
struct priority_group *next_pg; /* Switch to this PG if set */
atomic_t nr_valid_paths; /* Total number of usable paths */
unsigned int nr_priority_groups;
struct list_head priority_groups;
const char *hw_handler_name;
char *hw_handler_params;
wait_queue_head_t pg_init_wait; /* Wait for pg_init completion */
unsigned int pg_init_retries; /* Number of times to retry pg_init */
unsigned int pg_init_delay_msecs; /* Number of msecs before pg_init retry */
atomic_t pg_init_in_progress; /* Only one pg_init allowed at once */
atomic_t pg_init_count; /* Number of times pg_init called */
struct mutex work_mutex;
struct work_struct trigger_event;
struct dm_target *ti;
struct work_struct process_queued_bios;
struct bio_list queued_bios;
struct timer_list nopath_timer; /* Timeout for queue_if_no_path */
};
/*
* Context information attached to each io we process.
*/
struct dm_mpath_io {
struct pgpath *pgpath;
size_t nr_bytes;
u64 start_time_ns;
};
typedef int (*action_fn) (struct pgpath *pgpath);
static struct workqueue_struct *kmultipathd, *kmpath_handlerd;
static void trigger_event(struct work_struct *work);
static void activate_or_offline_path(struct pgpath *pgpath);
static void activate_path_work(struct work_struct *work);
static void process_queued_bios(struct work_struct *work);
static void queue_if_no_path_timeout_work(struct timer_list *t);
/*
*-----------------------------------------------
* Multipath state flags.
*-----------------------------------------------
*/
#define MPATHF_QUEUE_IO 0 /* Must we queue all I/O? */
#define MPATHF_QUEUE_IF_NO_PATH 1 /* Queue I/O if last path fails? */
#define MPATHF_SAVED_QUEUE_IF_NO_PATH 2 /* Saved state during suspension */
#define MPATHF_RETAIN_ATTACHED_HW_HANDLER 3 /* If there's already a hw_handler present, don't change it. */
#define MPATHF_PG_INIT_DISABLED 4 /* pg_init is not currently allowed */
#define MPATHF_PG_INIT_REQUIRED 5 /* pg_init needs calling? */
#define MPATHF_PG_INIT_DELAY_RETRY 6 /* Delay pg_init retry? */
static bool mpath_double_check_test_bit(int MPATHF_bit, struct multipath *m)
{
bool r = test_bit(MPATHF_bit, &m->flags);
if (r) {
unsigned long flags;
spin_lock_irqsave(&m->lock, flags);
r = test_bit(MPATHF_bit, &m->flags);
spin_unlock_irqrestore(&m->lock, flags);
}
return r;
}
/*
*-----------------------------------------------
* Allocation routines
*-----------------------------------------------
*/
static struct pgpath *alloc_pgpath(void)
{
struct pgpath *pgpath = kzalloc(sizeof(*pgpath), GFP_KERNEL);
if (!pgpath)
return NULL;
pgpath->is_active = true;
return pgpath;
}
static void free_pgpath(struct pgpath *pgpath)
{
kfree(pgpath);
}
static struct priority_group *alloc_priority_group(void)
{
struct priority_group *pg;
pg = kzalloc(sizeof(*pg), GFP_KERNEL);
if (pg)
INIT_LIST_HEAD(&pg->pgpaths);
return pg;
}
static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti)
{
struct pgpath *pgpath, *tmp;
list_for_each_entry_safe(pgpath, tmp, pgpaths, list) {
list_del(&pgpath->list);
dm_put_device(ti, pgpath->path.dev);
free_pgpath(pgpath);
}
}
static void free_priority_group(struct priority_group *pg,
struct dm_target *ti)
{
struct path_selector *ps = &pg->ps;
if (ps->type) {
ps->type->destroy(ps);
dm_put_path_selector(ps->type);
}
free_pgpaths(&pg->pgpaths, ti);
kfree(pg);
}
static struct multipath *alloc_multipath(struct dm_target *ti)
{
struct multipath *m;
m = kzalloc(sizeof(*m), GFP_KERNEL);
if (m) {
INIT_LIST_HEAD(&m->priority_groups);
spin_lock_init(&m->lock);
atomic_set(&m->nr_valid_paths, 0);
INIT_WORK(&m->trigger_event, trigger_event);
mutex_init(&m->work_mutex);
m->queue_mode = DM_TYPE_NONE;
m->ti = ti;
ti->private = m;
timer_setup(&m->nopath_timer, queue_if_no_path_timeout_work, 0);
}
return m;
}
static int alloc_multipath_stage2(struct dm_target *ti, struct multipath *m)
{
if (m->queue_mode == DM_TYPE_NONE) {
m->queue_mode = DM_TYPE_REQUEST_BASED;
} else if (m->queue_mode == DM_TYPE_BIO_BASED) {
INIT_WORK(&m->process_queued_bios, process_queued_bios);
/*
* bio-based doesn't support any direct scsi_dh management;
* it just discovers if a scsi_dh is attached.
*/
set_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags);
}
dm_table_set_type(ti->table, m->queue_mode);
/*
* Init fields that are only used when a scsi_dh is attached
* - must do this unconditionally (really doesn't hurt non-SCSI uses)
*/
set_bit(MPATHF_QUEUE_IO, &m->flags);
atomic_set(&m->pg_init_in_progress, 0);
atomic_set(&m->pg_init_count, 0);
m->pg_init_delay_msecs = DM_PG_INIT_DELAY_DEFAULT;
init_waitqueue_head(&m->pg_init_wait);
return 0;
}
static void free_multipath(struct multipath *m)
{
struct priority_group *pg, *tmp;
list_for_each_entry_safe(pg, tmp, &m->priority_groups, list) {
list_del(&pg->list);
free_priority_group(pg, m->ti);
}
kfree(m->hw_handler_name);
kfree(m->hw_handler_params);
mutex_destroy(&m->work_mutex);
kfree(m);
}
static struct dm_mpath_io *get_mpio(union map_info *info)
{
return info->ptr;
}
static size_t multipath_per_bio_data_size(void)
{
return sizeof(struct dm_mpath_io) + sizeof(struct dm_bio_details);
}
static struct dm_mpath_io *get_mpio_from_bio(struct bio *bio)
{
return dm_per_bio_data(bio, multipath_per_bio_data_size());
}
static struct dm_bio_details *get_bio_details_from_mpio(struct dm_mpath_io *mpio)
{
/* dm_bio_details is immediately after the dm_mpath_io in bio's per-bio-data */
void *bio_details = mpio + 1;
return bio_details;
}
static void multipath_init_per_bio_data(struct bio *bio, struct dm_mpath_io **mpio_p)
{
struct dm_mpath_io *mpio = get_mpio_from_bio(bio);
struct dm_bio_details *bio_details = get_bio_details_from_mpio(mpio);
mpio->nr_bytes = bio->bi_iter.bi_size;
mpio->pgpath = NULL;
mpio->start_time_ns = 0;
*mpio_p = mpio;
dm_bio_record(bio_details, bio);
}
/*
*-----------------------------------------------
* Path selection
*-----------------------------------------------
*/
static int __pg_init_all_paths(struct multipath *m)
{
struct pgpath *pgpath;
unsigned long pg_init_delay = 0;
lockdep_assert_held(&m->lock);
if (atomic_read(&m->pg_init_in_progress) || test_bit(MPATHF_PG_INIT_DISABLED, &m->flags))
return 0;
atomic_inc(&m->pg_init_count);
clear_bit(MPATHF_PG_INIT_REQUIRED, &m->flags);
/* Check here to reset pg_init_required */
if (!m->current_pg)
return 0;
if (test_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags))
pg_init_delay = msecs_to_jiffies(m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT ?
m->pg_init_delay_msecs : DM_PG_INIT_DELAY_MSECS);
list_for_each_entry(pgpath, &m->current_pg->pgpaths, list) {
/* Skip failed paths */
if (!pgpath->is_active)
continue;
if (queue_delayed_work(kmpath_handlerd, &pgpath->activate_path,
pg_init_delay))
atomic_inc(&m->pg_init_in_progress);
}
return atomic_read(&m->pg_init_in_progress);
}
static int pg_init_all_paths(struct multipath *m)
{
int ret;
unsigned long flags;
spin_lock_irqsave(&m->lock, flags);
ret = __pg_init_all_paths(m);
spin_unlock_irqrestore(&m->lock, flags);
return ret;
}
static void __switch_pg(struct multipath *m, struct priority_group *pg)
{
lockdep_assert_held(&m->lock);
m->current_pg = pg;
/* Must we initialise the PG first, and queue I/O till it's ready? */
if (m->hw_handler_name) {
set_bit(MPATHF_PG_INIT_REQUIRED, &m->flags);
set_bit(MPATHF_QUEUE_IO, &m->flags);
} else {
clear_bit(MPATHF_PG_INIT_REQUIRED, &m->flags);
clear_bit(MPATHF_QUEUE_IO, &m->flags);
}
atomic_set(&m->pg_init_count, 0);
}
static struct pgpath *choose_path_in_pg(struct multipath *m,
struct priority_group *pg,
size_t nr_bytes)
{
unsigned long flags;
struct dm_path *path;
struct pgpath *pgpath;
path = pg->ps.type->select_path(&pg->ps, nr_bytes);
if (!path)
return ERR_PTR(-ENXIO);
pgpath = path_to_pgpath(path);
if (unlikely(READ_ONCE(m->current_pg) != pg)) {
/* Only update current_pgpath if pg changed */
spin_lock_irqsave(&m->lock, flags);
m->current_pgpath = pgpath;
__switch_pg(m, pg);
spin_unlock_irqrestore(&m->lock, flags);
}
return pgpath;
}
static struct pgpath *choose_pgpath(struct multipath *m, size_t nr_bytes)
{
unsigned long flags;
struct priority_group *pg;
struct pgpath *pgpath;
unsigned int bypassed = 1;
if (!atomic_read(&m->nr_valid_paths)) {
spin_lock_irqsave(&m->lock, flags);
clear_bit(MPATHF_QUEUE_IO, &m->flags);
spin_unlock_irqrestore(&m->lock, flags);
goto failed;
}
/* Were we instructed to switch PG? */
if (READ_ONCE(m->next_pg)) {
spin_lock_irqsave(&m->lock, flags);
pg = m->next_pg;
if (!pg) {
spin_unlock_irqrestore(&m->lock, flags);
goto check_current_pg;
}
m->next_pg = NULL;
spin_unlock_irqrestore(&m->lock, flags);
pgpath = choose_path_in_pg(m, pg, nr_bytes);
if (!IS_ERR_OR_NULL(pgpath))
return pgpath;
}
/* Don't change PG until it has no remaining paths */
check_current_pg:
pg = READ_ONCE(m->current_pg);
if (pg) {
pgpath = choose_path_in_pg(m, pg, nr_bytes);
if (!IS_ERR_OR_NULL(pgpath))
return pgpath;
}
/*
* Loop through priority groups until we find a valid path.
* First time we skip PGs marked 'bypassed'.
* Second time we only try the ones we skipped, but set
* pg_init_delay_retry so we do not hammer controllers.
*/
do {
list_for_each_entry(pg, &m->priority_groups, list) {
if (pg->bypassed == !!bypassed)
continue;
pgpath = choose_path_in_pg(m, pg, nr_bytes);
if (!IS_ERR_OR_NULL(pgpath)) {
if (!bypassed) {
spin_lock_irqsave(&m->lock, flags);
set_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags);
spin_unlock_irqrestore(&m->lock, flags);
}
return pgpath;
}
}
} while (bypassed--);
failed:
spin_lock_irqsave(&m->lock, flags);
m->current_pgpath = NULL;
m->current_pg = NULL;
spin_unlock_irqrestore(&m->lock, flags);
return NULL;
}
/*
* dm_report_EIO() is a macro instead of a function to make pr_debug_ratelimited()
* report the function name and line number of the function from which
* it has been invoked.
*/
#define dm_report_EIO(m) \
DMDEBUG_LIMIT("%s: returning EIO; QIFNP = %d; SQIFNP = %d; DNFS = %d", \
dm_table_device_name((m)->ti->table), \
test_bit(MPATHF_QUEUE_IF_NO_PATH, &(m)->flags), \
test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &(m)->flags), \
dm_noflush_suspending((m)->ti))
/*
* Check whether bios must be queued in the device-mapper core rather
* than here in the target.
*/
static bool __must_push_back(struct multipath *m)
{
return dm_noflush_suspending(m->ti);
}
static bool must_push_back_rq(struct multipath *m)
{
unsigned long flags;
bool ret;
spin_lock_irqsave(&m->lock, flags);
ret = (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) || __must_push_back(m));
spin_unlock_irqrestore(&m->lock, flags);
return ret;
}
/*
* Map cloned requests (request-based multipath)
*/
static int multipath_clone_and_map(struct dm_target *ti, struct request *rq,
union map_info *map_context,
struct request **__clone)
{
struct multipath *m = ti->private;
size_t nr_bytes = blk_rq_bytes(rq);
struct pgpath *pgpath;
struct block_device *bdev;
struct dm_mpath_io *mpio = get_mpio(map_context);
struct request_queue *q;
struct request *clone;
/* Do we need to select a new pgpath? */
pgpath = READ_ONCE(m->current_pgpath);
if (!pgpath || !mpath_double_check_test_bit(MPATHF_QUEUE_IO, m))
pgpath = choose_pgpath(m, nr_bytes);
if (!pgpath) {
if (must_push_back_rq(m))
return DM_MAPIO_DELAY_REQUEUE;
dm_report_EIO(m); /* Failed */
return DM_MAPIO_KILL;
} else if (mpath_double_check_test_bit(MPATHF_QUEUE_IO, m) ||
mpath_double_check_test_bit(MPATHF_PG_INIT_REQUIRED, m)) {
pg_init_all_paths(m);
return DM_MAPIO_DELAY_REQUEUE;
}
mpio->pgpath = pgpath;
mpio->nr_bytes = nr_bytes;
bdev = pgpath->path.dev->bdev;
q = bdev_get_queue(bdev);
clone = blk_mq_alloc_request(q, rq->cmd_flags | REQ_NOMERGE,
BLK_MQ_REQ_NOWAIT);
if (IS_ERR(clone)) {
/* EBUSY, ENODEV or EWOULDBLOCK: requeue */
if (blk_queue_dying(q)) {
atomic_inc(&m->pg_init_in_progress);
activate_or_offline_path(pgpath);
return DM_MAPIO_DELAY_REQUEUE;
}
/*
* blk-mq's SCHED_RESTART can cover this requeue, so we
* needn't deal with it by DELAY_REQUEUE. More importantly,
* we have to return DM_MAPIO_REQUEUE so that blk-mq can
* get the queue busy feedback (via BLK_STS_RESOURCE),
* otherwise I/O merging can suffer.
*/
return DM_MAPIO_REQUEUE;
}
clone->bio = clone->biotail = NULL;
clone->cmd_flags |= REQ_FAILFAST_TRANSPORT;
*__clone = clone;
if (pgpath->pg->ps.type->start_io)
pgpath->pg->ps.type->start_io(&pgpath->pg->ps,
&pgpath->path,
nr_bytes);
return DM_MAPIO_REMAPPED;
}
static void multipath_release_clone(struct request *clone,
union map_info *map_context)
{
if (unlikely(map_context)) {
/*
* non-NULL map_context means caller is still map
* method; must undo multipath_clone_and_map()
*/
struct dm_mpath_io *mpio = get_mpio(map_context);
struct pgpath *pgpath = mpio->pgpath;
if (pgpath && pgpath->pg->ps.type->end_io)
pgpath->pg->ps.type->end_io(&pgpath->pg->ps,
&pgpath->path,
mpio->nr_bytes,
clone->io_start_time_ns);
}
blk_mq_free_request(clone);
}
/*
* Map cloned bios (bio-based multipath)
*/
static void __multipath_queue_bio(struct multipath *m, struct bio *bio)
{
/* Queue for the daemon to resubmit */
bio_list_add(&m->queued_bios, bio);
if (!test_bit(MPATHF_QUEUE_IO, &m->flags))
queue_work(kmultipathd, &m->process_queued_bios);
}
static void multipath_queue_bio(struct multipath *m, struct bio *bio)
{
unsigned long flags;
spin_lock_irqsave(&m->lock, flags);
__multipath_queue_bio(m, bio);
spin_unlock_irqrestore(&m->lock, flags);
}
static struct pgpath *__map_bio(struct multipath *m, struct bio *bio)
{
struct pgpath *pgpath;
unsigned long flags;
/* Do we need to select a new pgpath? */
pgpath = READ_ONCE(m->current_pgpath);
if (!pgpath || !mpath_double_check_test_bit(MPATHF_QUEUE_IO, m))
pgpath = choose_pgpath(m, bio->bi_iter.bi_size);
if (!pgpath) {
spin_lock_irqsave(&m->lock, flags);
if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
__multipath_queue_bio(m, bio);
pgpath = ERR_PTR(-EAGAIN);
}
spin_unlock_irqrestore(&m->lock, flags);
} else if (mpath_double_check_test_bit(MPATHF_QUEUE_IO, m) ||
mpath_double_check_test_bit(MPATHF_PG_INIT_REQUIRED, m)) {
multipath_queue_bio(m, bio);
pg_init_all_paths(m);
return ERR_PTR(-EAGAIN);
}
return pgpath;
}
static int __multipath_map_bio(struct multipath *m, struct bio *bio,
struct dm_mpath_io *mpio)
{
struct pgpath *pgpath = __map_bio(m, bio);
if (IS_ERR(pgpath))
return DM_MAPIO_SUBMITTED;
if (!pgpath) {
if (__must_push_back(m))
return DM_MAPIO_REQUEUE;
dm_report_EIO(m);
return DM_MAPIO_KILL;
}
mpio->pgpath = pgpath;
if (dm_ps_use_hr_timer(pgpath->pg->ps.type))
mpio->start_time_ns = ktime_get_ns();
bio->bi_status = 0;
bio_set_dev(bio, pgpath->path.dev->bdev);
bio->bi_opf |= REQ_FAILFAST_TRANSPORT;
if (pgpath->pg->ps.type->start_io)
pgpath->pg->ps.type->start_io(&pgpath->pg->ps,
&pgpath->path,
mpio->nr_bytes);
return DM_MAPIO_REMAPPED;
}
static int multipath_map_bio(struct dm_target *ti, struct bio *bio)
{
struct multipath *m = ti->private;
struct dm_mpath_io *mpio = NULL;
multipath_init_per_bio_data(bio, &mpio);
return __multipath_map_bio(m, bio, mpio);
}
static void process_queued_io_list(struct multipath *m)
{
if (m->queue_mode == DM_TYPE_REQUEST_BASED)
dm_mq_kick_requeue_list(dm_table_get_md(m->ti->table));
else if (m->queue_mode == DM_TYPE_BIO_BASED)
queue_work(kmultipathd, &m->process_queued_bios);
}
static void process_queued_bios(struct work_struct *work)
{
int r;
unsigned long flags;
struct bio *bio;
struct bio_list bios;
struct blk_plug plug;
struct multipath *m =
container_of(work, struct multipath, process_queued_bios);
bio_list_init(&bios);
spin_lock_irqsave(&m->lock, flags);
if (bio_list_empty(&m->queued_bios)) {
spin_unlock_irqrestore(&m->lock, flags);
return;
}
bio_list_merge(&bios, &m->queued_bios);
bio_list_init(&m->queued_bios);
spin_unlock_irqrestore(&m->lock, flags);
blk_start_plug(&plug);
while ((bio = bio_list_pop(&bios))) {
struct dm_mpath_io *mpio = get_mpio_from_bio(bio);
dm_bio_restore(get_bio_details_from_mpio(mpio), bio);
r = __multipath_map_bio(m, bio, mpio);
switch (r) {
case DM_MAPIO_KILL:
bio->bi_status = BLK_STS_IOERR;
bio_endio(bio);
break;
case DM_MAPIO_REQUEUE:
bio->bi_status = BLK_STS_DM_REQUEUE;
bio_endio(bio);
break;
case DM_MAPIO_REMAPPED:
submit_bio_noacct(bio);
break;
case DM_MAPIO_SUBMITTED:
break;
default:
WARN_ONCE(true, "__multipath_map_bio() returned %d\n", r);
}
}
blk_finish_plug(&plug);
}
/*
* If we run out of usable paths, should we queue I/O or error it?
*/
static int queue_if_no_path(struct multipath *m, bool f_queue_if_no_path,
bool save_old_value, const char *caller)
{
unsigned long flags;
bool queue_if_no_path_bit, saved_queue_if_no_path_bit;
const char *dm_dev_name = dm_table_device_name(m->ti->table);
DMDEBUG("%s: %s caller=%s f_queue_if_no_path=%d save_old_value=%d",
dm_dev_name, __func__, caller, f_queue_if_no_path, save_old_value);
spin_lock_irqsave(&m->lock, flags);
queue_if_no_path_bit = test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags);
saved_queue_if_no_path_bit = test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
if (save_old_value) {
if (unlikely(!queue_if_no_path_bit && saved_queue_if_no_path_bit)) {
DMERR("%s: QIFNP disabled but saved as enabled, saving again loses state, not saving!",
dm_dev_name);
} else
assign_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags, queue_if_no_path_bit);
} else if (!f_queue_if_no_path && saved_queue_if_no_path_bit) {
/* due to "fail_if_no_path" message, need to honor it. */
clear_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
}
assign_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags, f_queue_if_no_path);
DMDEBUG("%s: after %s changes; QIFNP = %d; SQIFNP = %d; DNFS = %d",
dm_dev_name, __func__,
test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags),
test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags),
dm_noflush_suspending(m->ti));
spin_unlock_irqrestore(&m->lock, flags);
if (!f_queue_if_no_path) {
dm_table_run_md_queue_async(m->ti->table);
process_queued_io_list(m);
}
return 0;
}
/*
* If the queue_if_no_path timeout fires, turn off queue_if_no_path and
* process any queued I/O.
*/
static void queue_if_no_path_timeout_work(struct timer_list *t)
{
struct multipath *m = from_timer(m, t, nopath_timer);
DMWARN("queue_if_no_path timeout on %s, failing queued IO",
dm_table_device_name(m->ti->table));
queue_if_no_path(m, false, false, __func__);
}
/*
* Enable the queue_if_no_path timeout if necessary.
* Called with m->lock held.
*/
static void enable_nopath_timeout(struct multipath *m)
{
unsigned long queue_if_no_path_timeout =
READ_ONCE(queue_if_no_path_timeout_secs) * HZ;
lockdep_assert_held(&m->lock);
if (queue_if_no_path_timeout > 0 &&
atomic_read(&m->nr_valid_paths) == 0 &&
test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
mod_timer(&m->nopath_timer,
jiffies + queue_if_no_path_timeout);
}
}
static void disable_nopath_timeout(struct multipath *m)
{
del_timer_sync(&m->nopath_timer);
}
/*
* An event is triggered whenever a path is taken out of use.
* Includes path failure and PG bypass.
*/
static void trigger_event(struct work_struct *work)
{
struct multipath *m =
container_of(work, struct multipath, trigger_event);
dm_table_event(m->ti->table);
}
/*
*---------------------------------------------------------------
* Constructor/argument parsing:
* <#multipath feature args> [<arg>]*
* <#hw_handler args> [hw_handler [<arg>]*]
* <#priority groups>
* <initial priority group>
* [<selector> <#selector args> [<arg>]*
* <#paths> <#per-path selector args>
* [<path> [<arg>]* ]+ ]+
*---------------------------------------------------------------
*/
static int parse_path_selector(struct dm_arg_set *as, struct priority_group *pg,
struct dm_target *ti)
{
int r;
struct path_selector_type *pst;
unsigned int ps_argc;
static const struct dm_arg _args[] = {
{0, 1024, "invalid number of path selector args"},
};
pst = dm_get_path_selector(dm_shift_arg(as));
if (!pst) {
ti->error = "unknown path selector type";
return -EINVAL;
}
r = dm_read_arg_group(_args, as, &ps_argc, &ti->error);
if (r) {
dm_put_path_selector(pst);
return -EINVAL;
}
r = pst->create(&pg->ps, ps_argc, as->argv);
if (r) {
dm_put_path_selector(pst);
ti->error = "path selector constructor failed";
return r;
}
pg->ps.type = pst;
dm_consume_args(as, ps_argc);
return 0;
}
static int setup_scsi_dh(struct block_device *bdev, struct multipath *m,
const char **attached_handler_name, char **error)
{
struct request_queue *q = bdev_get_queue(bdev);
int r;
if (mpath_double_check_test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, m)) {
retain:
if (*attached_handler_name) {
/*
* Clear any hw_handler_params associated with a
* handler that isn't already attached.
*/
if (m->hw_handler_name && strcmp(*attached_handler_name, m->hw_handler_name)) {
kfree(m->hw_handler_params);
m->hw_handler_params = NULL;
}
/*
* Reset hw_handler_name to match the attached handler
*
* NB. This modifies the table line to show the actual
* handler instead of the original table passed in.
*/
kfree(m->hw_handler_name);
m->hw_handler_name = *attached_handler_name;
*attached_handler_name = NULL;
}
}
if (m->hw_handler_name) {
r = scsi_dh_attach(q, m->hw_handler_name);
if (r == -EBUSY) {
DMINFO("retaining handler on device %pg", bdev);
goto retain;
}
if (r < 0) {
*error = "error attaching hardware handler";
return r;
}
if (m->hw_handler_params) {
r = scsi_dh_set_params(q, m->hw_handler_params);
if (r < 0) {
*error = "unable to set hardware handler parameters";
return r;
}
}
}
return 0;
}
static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps,
struct dm_target *ti)
{
int r;
struct pgpath *p;
struct multipath *m = ti->private;
struct request_queue *q;
const char *attached_handler_name = NULL;
/* we need at least a path arg */
if (as->argc < 1) {
ti->error = "no device given";
return ERR_PTR(-EINVAL);
}
p = alloc_pgpath();
if (!p)
return ERR_PTR(-ENOMEM);
r = dm_get_device(ti, dm_shift_arg(as), dm_table_get_mode(ti->table),
&p->path.dev);
if (r) {
ti->error = "error getting device";
goto bad;
}
q = bdev_get_queue(p->path.dev->bdev);
attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL);
if (attached_handler_name || m->hw_handler_name) {
INIT_DELAYED_WORK(&p->activate_path, activate_path_work);
r = setup_scsi_dh(p->path.dev->bdev, m, &attached_handler_name, &ti->error);
kfree(attached_handler_name);
if (r) {
dm_put_device(ti, p->path.dev);
goto bad;
}
}
r = ps->type->add_path(ps, &p->path, as->argc, as->argv, &ti->error);
if (r) {
dm_put_device(ti, p->path.dev);
goto bad;
}
return p;
bad:
free_pgpath(p);
return ERR_PTR(r);
}
static struct priority_group *parse_priority_group(struct dm_arg_set *as,
struct multipath *m)
{
static const struct dm_arg _args[] = {
{1, 1024, "invalid number of paths"},
{0, 1024, "invalid number of selector args"}
};
int r;
unsigned int i, nr_selector_args, nr_args;
struct priority_group *pg;
struct dm_target *ti = m->ti;
if (as->argc < 2) {
as->argc = 0;
ti->error = "not enough priority group arguments";
return ERR_PTR(-EINVAL);
}
pg = alloc_priority_group();
if (!pg) {
ti->error = "couldn't allocate priority group";
return ERR_PTR(-ENOMEM);
}
pg->m = m;
r = parse_path_selector(as, pg, ti);
if (r)
goto bad;
/*
* read the paths
*/
r = dm_read_arg(_args, as, &pg->nr_pgpaths, &ti->error);
if (r)
goto bad;
r = dm_read_arg(_args + 1, as, &nr_selector_args, &ti->error);
if (r)
goto bad;
nr_args = 1 + nr_selector_args;
for (i = 0; i < pg->nr_pgpaths; i++) {
struct pgpath *pgpath;
struct dm_arg_set path_args;
if (as->argc < nr_args) {
ti->error = "not enough path parameters";
r = -EINVAL;
goto bad;
}
path_args.argc = nr_args;
path_args.argv = as->argv;
pgpath = parse_path(&path_args, &pg->ps, ti);
if (IS_ERR(pgpath)) {
r = PTR_ERR(pgpath);
goto bad;
}
pgpath->pg = pg;
list_add_tail(&pgpath->list, &pg->pgpaths);
dm_consume_args(as, nr_args);
}
return pg;
bad:
free_priority_group(pg, ti);
return ERR_PTR(r);
}
static int parse_hw_handler(struct dm_arg_set *as, struct multipath *m)
{
unsigned int hw_argc;
int ret;
struct dm_target *ti = m->ti;
static const struct dm_arg _args[] = {
{0, 1024, "invalid number of hardware handler args"},
};
if (dm_read_arg_group(_args, as, &hw_argc, &ti->error))
return -EINVAL;
if (!hw_argc)
return 0;
if (m->queue_mode == DM_TYPE_BIO_BASED) {
dm_consume_args(as, hw_argc);
DMERR("bio-based multipath doesn't allow hardware handler args");
return 0;
}
m->hw_handler_name = kstrdup(dm_shift_arg(as), GFP_KERNEL);
if (!m->hw_handler_name)
return -EINVAL;
if (hw_argc > 1) {
char *p;
int i, j, len = 4;
for (i = 0; i <= hw_argc - 2; i++)
len += strlen(as->argv[i]) + 1;
p = m->hw_handler_params = kzalloc(len, GFP_KERNEL);
if (!p) {
ti->error = "memory allocation failed";
ret = -ENOMEM;
goto fail;
}
j = sprintf(p, "%d", hw_argc - 1);
for (i = 0, p += j + 1; i <= hw_argc - 2; i++, p += j + 1)
j = sprintf(p, "%s", as->argv[i]);
}
dm_consume_args(as, hw_argc - 1);
return 0;
fail:
kfree(m->hw_handler_name);
m->hw_handler_name = NULL;
return ret;
}
static int parse_features(struct dm_arg_set *as, struct multipath *m)
{
int r;
unsigned int argc;
struct dm_target *ti = m->ti;
const char *arg_name;
static const struct dm_arg _args[] = {
{0, 8, "invalid number of feature args"},
{1, 50, "pg_init_retries must be between 1 and 50"},
{0, 60000, "pg_init_delay_msecs must be between 0 and 60000"},
};
r = dm_read_arg_group(_args, as, &argc, &ti->error);
if (r)
return -EINVAL;
if (!argc)
return 0;
do {
arg_name = dm_shift_arg(as);
argc--;
if (!strcasecmp(arg_name, "queue_if_no_path")) {
r = queue_if_no_path(m, true, false, __func__);
continue;
}
if (!strcasecmp(arg_name, "retain_attached_hw_handler")) {
set_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags);
continue;
}
if (!strcasecmp(arg_name, "pg_init_retries") &&
(argc >= 1)) {
r = dm_read_arg(_args + 1, as, &m->pg_init_retries, &ti->error);
argc--;
continue;
}
if (!strcasecmp(arg_name, "pg_init_delay_msecs") &&
(argc >= 1)) {
r = dm_read_arg(_args + 2, as, &m->pg_init_delay_msecs, &ti->error);
argc--;
continue;
}
if (!strcasecmp(arg_name, "queue_mode") &&
(argc >= 1)) {
const char *queue_mode_name = dm_shift_arg(as);
if (!strcasecmp(queue_mode_name, "bio"))
m->queue_mode = DM_TYPE_BIO_BASED;
else if (!strcasecmp(queue_mode_name, "rq") ||
!strcasecmp(queue_mode_name, "mq"))
m->queue_mode = DM_TYPE_REQUEST_BASED;
else {
ti->error = "Unknown 'queue_mode' requested";
r = -EINVAL;
}
argc--;
continue;
}
ti->error = "Unrecognised multipath feature request";
r = -EINVAL;
} while (argc && !r);
return r;
}
static int multipath_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
/* target arguments */
static const struct dm_arg _args[] = {
{0, 1024, "invalid number of priority groups"},
{0, 1024, "invalid initial priority group number"},
};
int r;
struct multipath *m;
struct dm_arg_set as;
unsigned int pg_count = 0;
unsigned int next_pg_num;
unsigned long flags;
as.argc = argc;
as.argv = argv;
m = alloc_multipath(ti);
if (!m) {
ti->error = "can't allocate multipath";
return -EINVAL;
}
r = parse_features(&as, m);
if (r)
goto bad;
r = alloc_multipath_stage2(ti, m);
if (r)
goto bad;
r = parse_hw_handler(&as, m);
if (r)
goto bad;
r = dm_read_arg(_args, &as, &m->nr_priority_groups, &ti->error);
if (r)
goto bad;
r = dm_read_arg(_args + 1, &as, &next_pg_num, &ti->error);
if (r)
goto bad;
if ((!m->nr_priority_groups && next_pg_num) ||
(m->nr_priority_groups && !next_pg_num)) {
ti->error = "invalid initial priority group";
r = -EINVAL;
goto bad;
}
/* parse the priority groups */
while (as.argc) {
struct priority_group *pg;
unsigned int nr_valid_paths = atomic_read(&m->nr_valid_paths);
pg = parse_priority_group(&as, m);
if (IS_ERR(pg)) {
r = PTR_ERR(pg);
goto bad;
}
nr_valid_paths += pg->nr_pgpaths;
atomic_set(&m->nr_valid_paths, nr_valid_paths);
list_add_tail(&pg->list, &m->priority_groups);
pg_count++;
pg->pg_num = pg_count;
if (!--next_pg_num)
m->next_pg = pg;
}
if (pg_count != m->nr_priority_groups) {
ti->error = "priority group count mismatch";
r = -EINVAL;
goto bad;
}
spin_lock_irqsave(&m->lock, flags);
enable_nopath_timeout(m);
spin_unlock_irqrestore(&m->lock, flags);
ti->num_flush_bios = 1;
ti->num_discard_bios = 1;
ti->num_write_zeroes_bios = 1;
if (m->queue_mode == DM_TYPE_BIO_BASED)
ti->per_io_data_size = multipath_per_bio_data_size();
else
ti->per_io_data_size = sizeof(struct dm_mpath_io);
return 0;
bad:
free_multipath(m);
return r;
}
static void multipath_wait_for_pg_init_completion(struct multipath *m)
{
DEFINE_WAIT(wait);
while (1) {
prepare_to_wait(&m->pg_init_wait, &wait, TASK_UNINTERRUPTIBLE);
if (!atomic_read(&m->pg_init_in_progress))
break;
io_schedule();
}
finish_wait(&m->pg_init_wait, &wait);
}
static void flush_multipath_work(struct multipath *m)
{
if (m->hw_handler_name) {
unsigned long flags;
if (!atomic_read(&m->pg_init_in_progress))
goto skip;
spin_lock_irqsave(&m->lock, flags);
if (atomic_read(&m->pg_init_in_progress) &&
!test_and_set_bit(MPATHF_PG_INIT_DISABLED, &m->flags)) {
spin_unlock_irqrestore(&m->lock, flags);
flush_workqueue(kmpath_handlerd);
multipath_wait_for_pg_init_completion(m);
spin_lock_irqsave(&m->lock, flags);
clear_bit(MPATHF_PG_INIT_DISABLED, &m->flags);
}
spin_unlock_irqrestore(&m->lock, flags);
}
skip:
if (m->queue_mode == DM_TYPE_BIO_BASED)
flush_work(&m->process_queued_bios);
flush_work(&m->trigger_event);
}
static void multipath_dtr(struct dm_target *ti)
{
struct multipath *m = ti->private;
disable_nopath_timeout(m);
flush_multipath_work(m);
free_multipath(m);
}
/*
* Take a path out of use.
*/
static int fail_path(struct pgpath *pgpath)
{
unsigned long flags;
struct multipath *m = pgpath->pg->m;
spin_lock_irqsave(&m->lock, flags);
if (!pgpath->is_active)
goto out;
DMWARN("%s: Failing path %s.",
dm_table_device_name(m->ti->table),
pgpath->path.dev->name);
pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path);
pgpath->is_active = false;
pgpath->fail_count++;
atomic_dec(&m->nr_valid_paths);
if (pgpath == m->current_pgpath)
m->current_pgpath = NULL;
dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti,
pgpath->path.dev->name, atomic_read(&m->nr_valid_paths));
queue_work(dm_mpath_wq, &m->trigger_event);
enable_nopath_timeout(m);
out:
spin_unlock_irqrestore(&m->lock, flags);
return 0;
}
/*
* Reinstate a previously-failed path
*/
static int reinstate_path(struct pgpath *pgpath)
{
int r = 0, run_queue = 0;
unsigned long flags;
struct multipath *m = pgpath->pg->m;
unsigned int nr_valid_paths;
spin_lock_irqsave(&m->lock, flags);
if (pgpath->is_active)
goto out;
DMWARN("%s: Reinstating path %s.",
dm_table_device_name(m->ti->table),
pgpath->path.dev->name);
r = pgpath->pg->ps.type->reinstate_path(&pgpath->pg->ps, &pgpath->path);
if (r)
goto out;
pgpath->is_active = true;
nr_valid_paths = atomic_inc_return(&m->nr_valid_paths);
if (nr_valid_paths == 1) {
m->current_pgpath = NULL;
run_queue = 1;
} else if (m->hw_handler_name && (m->current_pg == pgpath->pg)) {
if (queue_work(kmpath_handlerd, &pgpath->activate_path.work))
atomic_inc(&m->pg_init_in_progress);
}
dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti,
pgpath->path.dev->name, nr_valid_paths);
schedule_work(&m->trigger_event);
out:
spin_unlock_irqrestore(&m->lock, flags);
if (run_queue) {
dm_table_run_md_queue_async(m->ti->table);
process_queued_io_list(m);
}
if (pgpath->is_active)
disable_nopath_timeout(m);
return r;
}
/*
* Fail or reinstate all paths that match the provided struct dm_dev.
*/
static int action_dev(struct multipath *m, struct dm_dev *dev,
action_fn action)
{
int r = -EINVAL;
struct pgpath *pgpath;
struct priority_group *pg;
list_for_each_entry(pg, &m->priority_groups, list) {
list_for_each_entry(pgpath, &pg->pgpaths, list) {
if (pgpath->path.dev == dev)
r = action(pgpath);
}
}
return r;
}
/*
* Temporarily try to avoid having to use the specified PG
*/
static void bypass_pg(struct multipath *m, struct priority_group *pg,
bool bypassed)
{
unsigned long flags;
spin_lock_irqsave(&m->lock, flags);
pg->bypassed = bypassed;
m->current_pgpath = NULL;
m->current_pg = NULL;
spin_unlock_irqrestore(&m->lock, flags);
schedule_work(&m->trigger_event);
}
/*
* Switch to using the specified PG from the next I/O that gets mapped
*/
static int switch_pg_num(struct multipath *m, const char *pgstr)
{
struct priority_group *pg;
unsigned int pgnum;
unsigned long flags;
char dummy;
if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum ||
!m->nr_priority_groups || (pgnum > m->nr_priority_groups)) {
DMWARN("invalid PG number supplied to %s", __func__);
return -EINVAL;
}
spin_lock_irqsave(&m->lock, flags);
list_for_each_entry(pg, &m->priority_groups, list) {
pg->bypassed = false;
if (--pgnum)
continue;
m->current_pgpath = NULL;
m->current_pg = NULL;
m->next_pg = pg;
}
spin_unlock_irqrestore(&m->lock, flags);
schedule_work(&m->trigger_event);
return 0;
}
/*
* Set/clear bypassed status of a PG.
* PGs are numbered upwards from 1 in the order they were declared.
*/
static int bypass_pg_num(struct multipath *m, const char *pgstr, bool bypassed)
{
struct priority_group *pg;
unsigned int pgnum;
char dummy;
if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum ||
!m->nr_priority_groups || (pgnum > m->nr_priority_groups)) {
DMWARN("invalid PG number supplied to bypass_pg");
return -EINVAL;
}
list_for_each_entry(pg, &m->priority_groups, list) {
if (!--pgnum)
break;
}
bypass_pg(m, pg, bypassed);
return 0;
}
/*
* Should we retry pg_init immediately?
*/
static bool pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath)
{
unsigned long flags;
bool limit_reached = false;
spin_lock_irqsave(&m->lock, flags);
if (atomic_read(&m->pg_init_count) <= m->pg_init_retries &&
!test_bit(MPATHF_PG_INIT_DISABLED, &m->flags))
set_bit(MPATHF_PG_INIT_REQUIRED, &m->flags);
else
limit_reached = true;
spin_unlock_irqrestore(&m->lock, flags);
return limit_reached;
}
static void pg_init_done(void *data, int errors)
{
struct pgpath *pgpath = data;
struct priority_group *pg = pgpath->pg;
struct multipath *m = pg->m;
unsigned long flags;
bool delay_retry = false;
/* device or driver problems */
switch (errors) {
case SCSI_DH_OK:
break;
case SCSI_DH_NOSYS:
if (!m->hw_handler_name) {
errors = 0;
break;
}
DMERR("Could not failover the device: Handler scsi_dh_%s "
"Error %d.", m->hw_handler_name, errors);
/*
* Fail path for now, so we do not ping pong
*/
fail_path(pgpath);
break;
case SCSI_DH_DEV_TEMP_BUSY:
/*
* Probably doing something like FW upgrade on the
* controller so try the other pg.
*/
bypass_pg(m, pg, true);
break;
case SCSI_DH_RETRY:
/* Wait before retrying. */
delay_retry = true;
fallthrough;
case SCSI_DH_IMM_RETRY:
case SCSI_DH_RES_TEMP_UNAVAIL:
if (pg_init_limit_reached(m, pgpath))
fail_path(pgpath);
errors = 0;
break;
case SCSI_DH_DEV_OFFLINED:
default:
/*
* We probably do not want to fail the path for a device
* error, but this is what the old dm did. In future
* patches we can do more advanced handling.
*/
fail_path(pgpath);
}
spin_lock_irqsave(&m->lock, flags);
if (errors) {
if (pgpath == m->current_pgpath) {
DMERR("Could not failover device. Error %d.", errors);
m->current_pgpath = NULL;
m->current_pg = NULL;
}
} else if (!test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags))
pg->bypassed = false;
if (atomic_dec_return(&m->pg_init_in_progress) > 0)
/* Activations of other paths are still on going */
goto out;
if (test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) {
if (delay_retry)
set_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags);
else
clear_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags);
if (__pg_init_all_paths(m))
goto out;
}
clear_bit(MPATHF_QUEUE_IO, &m->flags);
process_queued_io_list(m);
/*
* Wake up any thread waiting to suspend.
*/
wake_up(&m->pg_init_wait);
out:
spin_unlock_irqrestore(&m->lock, flags);
}
static void activate_or_offline_path(struct pgpath *pgpath)
{
struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev);
if (pgpath->is_active && !blk_queue_dying(q))
scsi_dh_activate(q, pg_init_done, pgpath);
else
pg_init_done(pgpath, SCSI_DH_DEV_OFFLINED);
}
static void activate_path_work(struct work_struct *work)
{
struct pgpath *pgpath =
container_of(work, struct pgpath, activate_path.work);
activate_or_offline_path(pgpath);
}
static int multipath_end_io(struct dm_target *ti, struct request *clone,
blk_status_t error, union map_info *map_context)
{
struct dm_mpath_io *mpio = get_mpio(map_context);
struct pgpath *pgpath = mpio->pgpath;
int r = DM_ENDIO_DONE;
/*
* We don't queue any clone request inside the multipath target
* during end I/O handling, since those clone requests don't have
* bio clones. If we queue them inside the multipath target,
* we need to make bio clones, that requires memory allocation.
* (See drivers/md/dm-rq.c:end_clone_bio() about why the clone requests
* don't have bio clones.)
* Instead of queueing the clone request here, we queue the original
* request into dm core, which will remake a clone request and
* clone bios for it and resubmit it later.
*/
if (error && blk_path_error(error)) {
struct multipath *m = ti->private;
if (error == BLK_STS_RESOURCE)
r = DM_ENDIO_DELAY_REQUEUE;
else
r = DM_ENDIO_REQUEUE;
if (pgpath)
fail_path(pgpath);
if (!atomic_read(&m->nr_valid_paths) &&
!must_push_back_rq(m)) {
if (error == BLK_STS_IOERR)
dm_report_EIO(m);
/* complete with the original error */
r = DM_ENDIO_DONE;
}
}
if (pgpath) {
struct path_selector *ps = &pgpath->pg->ps;
if (ps->type->end_io)
ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes,
clone->io_start_time_ns);
}
return r;
}
static int multipath_end_io_bio(struct dm_target *ti, struct bio *clone,
blk_status_t *error)
{
struct multipath *m = ti->private;
struct dm_mpath_io *mpio = get_mpio_from_bio(clone);
struct pgpath *pgpath = mpio->pgpath;
unsigned long flags;
int r = DM_ENDIO_DONE;
if (!*error || !blk_path_error(*error))
goto done;
if (pgpath)
fail_path(pgpath);
if (!atomic_read(&m->nr_valid_paths)) {
spin_lock_irqsave(&m->lock, flags);
if (!test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
if (__must_push_back(m)) {
r = DM_ENDIO_REQUEUE;
} else {
dm_report_EIO(m);
*error = BLK_STS_IOERR;
}
spin_unlock_irqrestore(&m->lock, flags);
goto done;
}
spin_unlock_irqrestore(&m->lock, flags);
}
multipath_queue_bio(m, clone);
r = DM_ENDIO_INCOMPLETE;
done:
if (pgpath) {
struct path_selector *ps = &pgpath->pg->ps;
if (ps->type->end_io)
ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes,
(mpio->start_time_ns ?:
dm_start_time_ns_from_clone(clone)));
}
return r;
}
/*
* Suspend with flush can't complete until all the I/O is processed
* so if the last path fails we must error any remaining I/O.
* - Note that if the freeze_bdev fails while suspending, the
* queue_if_no_path state is lost - userspace should reset it.
* Otherwise, during noflush suspend, queue_if_no_path will not change.
*/
static void multipath_presuspend(struct dm_target *ti)
{
struct multipath *m = ti->private;
/* FIXME: bio-based shouldn't need to always disable queue_if_no_path */
if (m->queue_mode == DM_TYPE_BIO_BASED || !dm_noflush_suspending(m->ti))
queue_if_no_path(m, false, true, __func__);
}
static void multipath_postsuspend(struct dm_target *ti)
{
struct multipath *m = ti->private;
mutex_lock(&m->work_mutex);
flush_multipath_work(m);
mutex_unlock(&m->work_mutex);
}
/*
* Restore the queue_if_no_path setting.
*/
static void multipath_resume(struct dm_target *ti)
{
struct multipath *m = ti->private;
unsigned long flags;
spin_lock_irqsave(&m->lock, flags);
if (test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags)) {
set_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags);
clear_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags);
}
DMDEBUG("%s: %s finished; QIFNP = %d; SQIFNP = %d",
dm_table_device_name(m->ti->table), __func__,
test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags),
test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags));
spin_unlock_irqrestore(&m->lock, flags);
}
/*
* Info output has the following format:
* num_multipath_feature_args [multipath_feature_args]*
* num_handler_status_args [handler_status_args]*
* num_groups init_group_number
* [A|D|E num_ps_status_args [ps_status_args]*
* num_paths num_selector_args
* [path_dev A|F fail_count [selector_args]* ]+ ]+
*
* Table output has the following format (identical to the constructor string):
* num_feature_args [features_args]*
* num_handler_args hw_handler [hw_handler_args]*
* num_groups init_group_number
* [priority selector-name num_ps_args [ps_args]*
* num_paths num_selector_args [path_dev [selector_args]* ]+ ]+
*/
static void multipath_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
int sz = 0, pg_counter, pgpath_counter;
unsigned long flags;
struct multipath *m = ti->private;
struct priority_group *pg;
struct pgpath *p;
unsigned int pg_num;
char state;
spin_lock_irqsave(&m->lock, flags);
/* Features */
if (type == STATUSTYPE_INFO)
DMEMIT("2 %u %u ", test_bit(MPATHF_QUEUE_IO, &m->flags),
atomic_read(&m->pg_init_count));
else {
DMEMIT("%u ", test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) +
(m->pg_init_retries > 0) * 2 +
(m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) * 2 +
test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags) +
(m->queue_mode != DM_TYPE_REQUEST_BASED) * 2);
if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
DMEMIT("queue_if_no_path ");
if (m->pg_init_retries)
DMEMIT("pg_init_retries %u ", m->pg_init_retries);
if (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT)
DMEMIT("pg_init_delay_msecs %u ", m->pg_init_delay_msecs);
if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags))
DMEMIT("retain_attached_hw_handler ");
if (m->queue_mode != DM_TYPE_REQUEST_BASED) {
switch (m->queue_mode) {
case DM_TYPE_BIO_BASED:
DMEMIT("queue_mode bio ");
break;
default:
WARN_ON_ONCE(true);
break;
}
}
}
if (!m->hw_handler_name || type == STATUSTYPE_INFO)
DMEMIT("0 ");
else
DMEMIT("1 %s ", m->hw_handler_name);
DMEMIT("%u ", m->nr_priority_groups);
if (m->next_pg)
pg_num = m->next_pg->pg_num;
else if (m->current_pg)
pg_num = m->current_pg->pg_num;
else
pg_num = (m->nr_priority_groups ? 1 : 0);
DMEMIT("%u ", pg_num);
switch (type) {
case STATUSTYPE_INFO:
list_for_each_entry(pg, &m->priority_groups, list) {
if (pg->bypassed)
state = 'D'; /* Disabled */
else if (pg == m->current_pg)
state = 'A'; /* Currently Active */
else
state = 'E'; /* Enabled */
DMEMIT("%c ", state);
if (pg->ps.type->status)
sz += pg->ps.type->status(&pg->ps, NULL, type,
result + sz,
maxlen - sz);
else
DMEMIT("0 ");
DMEMIT("%u %u ", pg->nr_pgpaths,
pg->ps.type->info_args);
list_for_each_entry(p, &pg->pgpaths, list) {
DMEMIT("%s %s %u ", p->path.dev->name,
p->is_active ? "A" : "F",
p->fail_count);
if (pg->ps.type->status)
sz += pg->ps.type->status(&pg->ps,
&p->path, type, result + sz,
maxlen - sz);
}
}
break;
case STATUSTYPE_TABLE:
list_for_each_entry(pg, &m->priority_groups, list) {
DMEMIT("%s ", pg->ps.type->name);
if (pg->ps.type->status)
sz += pg->ps.type->status(&pg->ps, NULL, type,
result + sz,
maxlen - sz);
else
DMEMIT("0 ");
DMEMIT("%u %u ", pg->nr_pgpaths,
pg->ps.type->table_args);
list_for_each_entry(p, &pg->pgpaths, list) {
DMEMIT("%s ", p->path.dev->name);
if (pg->ps.type->status)
sz += pg->ps.type->status(&pg->ps,
&p->path, type, result + sz,
maxlen - sz);
}
}
break;
case STATUSTYPE_IMA:
sz = 0; /*reset the result pointer*/
DMEMIT_TARGET_NAME_VERSION(ti->type);
DMEMIT(",nr_priority_groups=%u", m->nr_priority_groups);
pg_counter = 0;
list_for_each_entry(pg, &m->priority_groups, list) {
if (pg->bypassed)
state = 'D'; /* Disabled */
else if (pg == m->current_pg)
state = 'A'; /* Currently Active */
else
state = 'E'; /* Enabled */
DMEMIT(",pg_state_%d=%c", pg_counter, state);
DMEMIT(",nr_pgpaths_%d=%u", pg_counter, pg->nr_pgpaths);
DMEMIT(",path_selector_name_%d=%s", pg_counter, pg->ps.type->name);
pgpath_counter = 0;
list_for_each_entry(p, &pg->pgpaths, list) {
DMEMIT(",path_name_%d_%d=%s,is_active_%d_%d=%c,fail_count_%d_%d=%u",
pg_counter, pgpath_counter, p->path.dev->name,
pg_counter, pgpath_counter, p->is_active ? 'A' : 'F',
pg_counter, pgpath_counter, p->fail_count);
if (pg->ps.type->status) {
DMEMIT(",path_selector_status_%d_%d=",
pg_counter, pgpath_counter);
sz += pg->ps.type->status(&pg->ps, &p->path,
type, result + sz,
maxlen - sz);
}
pgpath_counter++;
}
pg_counter++;
}
DMEMIT(";");
break;
}
spin_unlock_irqrestore(&m->lock, flags);
}
static int multipath_message(struct dm_target *ti, unsigned int argc, char **argv,
char *result, unsigned int maxlen)
{
int r = -EINVAL;
struct dm_dev *dev;
struct multipath *m = ti->private;
action_fn action;
unsigned long flags;
mutex_lock(&m->work_mutex);
if (dm_suspended(ti)) {
r = -EBUSY;
goto out;
}
if (argc == 1) {
if (!strcasecmp(argv[0], "queue_if_no_path")) {
r = queue_if_no_path(m, true, false, __func__);
spin_lock_irqsave(&m->lock, flags);
enable_nopath_timeout(m);
spin_unlock_irqrestore(&m->lock, flags);
goto out;
} else if (!strcasecmp(argv[0], "fail_if_no_path")) {
r = queue_if_no_path(m, false, false, __func__);
disable_nopath_timeout(m);
goto out;
}
}
if (argc != 2) {
DMWARN("Invalid multipath message arguments. Expected 2 arguments, got %d.", argc);
goto out;
}
if (!strcasecmp(argv[0], "disable_group")) {
r = bypass_pg_num(m, argv[1], true);
goto out;
} else if (!strcasecmp(argv[0], "enable_group")) {
r = bypass_pg_num(m, argv[1], false);
goto out;
} else if (!strcasecmp(argv[0], "switch_group")) {
r = switch_pg_num(m, argv[1]);
goto out;
} else if (!strcasecmp(argv[0], "reinstate_path"))
action = reinstate_path;
else if (!strcasecmp(argv[0], "fail_path"))
action = fail_path;
else {
DMWARN("Unrecognised multipath message received: %s", argv[0]);
goto out;
}
r = dm_get_device(ti, argv[1], dm_table_get_mode(ti->table), &dev);
if (r) {
DMWARN("message: error getting device %s",
argv[1]);
goto out;
}
r = action_dev(m, dev, action);
dm_put_device(ti, dev);
out:
mutex_unlock(&m->work_mutex);
return r;
}
static int multipath_prepare_ioctl(struct dm_target *ti,
struct block_device **bdev)
{
struct multipath *m = ti->private;
struct pgpath *pgpath;
unsigned long flags;
int r;
pgpath = READ_ONCE(m->current_pgpath);
if (!pgpath || !mpath_double_check_test_bit(MPATHF_QUEUE_IO, m))
pgpath = choose_pgpath(m, 0);
if (pgpath) {
if (!mpath_double_check_test_bit(MPATHF_QUEUE_IO, m)) {
*bdev = pgpath->path.dev->bdev;
r = 0;
} else {
/* pg_init has not started or completed */
r = -ENOTCONN;
}
} else {
/* No path is available */
r = -EIO;
spin_lock_irqsave(&m->lock, flags);
if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))
r = -ENOTCONN;
spin_unlock_irqrestore(&m->lock, flags);
}
if (r == -ENOTCONN) {
if (!READ_ONCE(m->current_pg)) {
/* Path status changed, redo selection */
(void) choose_pgpath(m, 0);
}
spin_lock_irqsave(&m->lock, flags);
if (test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags))
(void) __pg_init_all_paths(m);
spin_unlock_irqrestore(&m->lock, flags);
dm_table_run_md_queue_async(m->ti->table);
process_queued_io_list(m);
}
/*
* Only pass ioctls through if the device sizes match exactly.
*/
if (!r && ti->len != bdev_nr_sectors((*bdev)))
return 1;
return r;
}
static int multipath_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct multipath *m = ti->private;
struct priority_group *pg;
struct pgpath *p;
int ret = 0;
list_for_each_entry(pg, &m->priority_groups, list) {
list_for_each_entry(p, &pg->pgpaths, list) {
ret = fn(ti, p->path.dev, ti->begin, ti->len, data);
if (ret)
goto out;
}
}
out:
return ret;
}
static int pgpath_busy(struct pgpath *pgpath)
{
struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev);
return blk_lld_busy(q);
}
/*
* We return "busy", only when we can map I/Os but underlying devices
* are busy (so even if we map I/Os now, the I/Os will wait on
* the underlying queue).
* In other words, if we want to kill I/Os or queue them inside us
* due to map unavailability, we don't return "busy". Otherwise,
* dm core won't give us the I/Os and we can't do what we want.
*/
static int multipath_busy(struct dm_target *ti)
{
bool busy = false, has_active = false;
struct multipath *m = ti->private;
struct priority_group *pg, *next_pg;
struct pgpath *pgpath;
/* pg_init in progress */
if (atomic_read(&m->pg_init_in_progress))
return true;
/* no paths available, for blk-mq: rely on IO mapping to delay requeue */
if (!atomic_read(&m->nr_valid_paths)) {
unsigned long flags;
spin_lock_irqsave(&m->lock, flags);
if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) {
spin_unlock_irqrestore(&m->lock, flags);
return (m->queue_mode != DM_TYPE_REQUEST_BASED);
}
spin_unlock_irqrestore(&m->lock, flags);
}
/* Guess which priority_group will be used at next mapping time */
pg = READ_ONCE(m->current_pg);
next_pg = READ_ONCE(m->next_pg);
if (unlikely(!READ_ONCE(m->current_pgpath) && next_pg))
pg = next_pg;
if (!pg) {
/*
* We don't know which pg will be used at next mapping time.
* We don't call choose_pgpath() here to avoid to trigger
* pg_init just by busy checking.
* So we don't know whether underlying devices we will be using
* at next mapping time are busy or not. Just try mapping.
*/
return busy;
}
/*
* If there is one non-busy active path at least, the path selector
* will be able to select it. So we consider such a pg as not busy.
*/
busy = true;
list_for_each_entry(pgpath, &pg->pgpaths, list) {
if (pgpath->is_active) {
has_active = true;
if (!pgpath_busy(pgpath)) {
busy = false;
break;
}
}
}
if (!has_active) {
/*
* No active path in this pg, so this pg won't be used and
* the current_pg will be changed at next mapping time.
* We need to try mapping to determine it.
*/
busy = false;
}
return busy;
}
/*
*---------------------------------------------------------------
* Module setup
*---------------------------------------------------------------
*/
static struct target_type multipath_target = {
.name = "multipath",
.version = {1, 14, 0},
.features = DM_TARGET_SINGLETON | DM_TARGET_IMMUTABLE |
DM_TARGET_PASSES_INTEGRITY,
.module = THIS_MODULE,
.ctr = multipath_ctr,
.dtr = multipath_dtr,
.clone_and_map_rq = multipath_clone_and_map,
.release_clone_rq = multipath_release_clone,
.rq_end_io = multipath_end_io,
.map = multipath_map_bio,
.end_io = multipath_end_io_bio,
.presuspend = multipath_presuspend,
.postsuspend = multipath_postsuspend,
.resume = multipath_resume,
.status = multipath_status,
.message = multipath_message,
.prepare_ioctl = multipath_prepare_ioctl,
.iterate_devices = multipath_iterate_devices,
.busy = multipath_busy,
};
static int __init dm_multipath_init(void)
{
int r = -ENOMEM;
kmultipathd = alloc_workqueue("kmpathd", WQ_MEM_RECLAIM, 0);
if (!kmultipathd) {
DMERR("failed to create workqueue kmpathd");
goto bad_alloc_kmultipathd;
}
/*
* A separate workqueue is used to handle the device handlers
* to avoid overloading existing workqueue. Overloading the
* old workqueue would also create a bottleneck in the
* path of the storage hardware device activation.
*/
kmpath_handlerd = alloc_ordered_workqueue("kmpath_handlerd",
WQ_MEM_RECLAIM);
if (!kmpath_handlerd) {
DMERR("failed to create workqueue kmpath_handlerd");
goto bad_alloc_kmpath_handlerd;
}
dm_mpath_wq = alloc_workqueue("dm_mpath_wq", 0, 0);
if (!dm_mpath_wq) {
DMERR("failed to create workqueue dm_mpath_wq");
goto bad_alloc_dm_mpath_wq;
}
r = dm_register_target(&multipath_target);
if (r < 0)
goto bad_register_target;
return 0;
bad_register_target:
destroy_workqueue(dm_mpath_wq);
bad_alloc_dm_mpath_wq:
destroy_workqueue(kmpath_handlerd);
bad_alloc_kmpath_handlerd:
destroy_workqueue(kmultipathd);
bad_alloc_kmultipathd:
return r;
}
static void __exit dm_multipath_exit(void)
{
destroy_workqueue(dm_mpath_wq);
destroy_workqueue(kmpath_handlerd);
destroy_workqueue(kmultipathd);
dm_unregister_target(&multipath_target);
}
module_init(dm_multipath_init);
module_exit(dm_multipath_exit);
module_param_named(queue_if_no_path_timeout_secs, queue_if_no_path_timeout_secs, ulong, 0644);
MODULE_PARM_DESC(queue_if_no_path_timeout_secs, "No available paths queue IO timeout in seconds");
MODULE_DESCRIPTION(DM_NAME " multipath target");
MODULE_AUTHOR("Sistina Software <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-mpath.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2001-2003 Sistina Software (UK) Limited.
*
* This file is released under the GPL.
*/
#include "dm.h"
#include <linux/device-mapper.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/bio.h>
#include <linux/dax.h>
#include <linux/slab.h>
#include <linux/log2.h>
static struct workqueue_struct *dm_stripe_wq;
#define DM_MSG_PREFIX "striped"
#define DM_IO_ERROR_THRESHOLD 15
struct stripe {
struct dm_dev *dev;
sector_t physical_start;
atomic_t error_count;
};
struct stripe_c {
uint32_t stripes;
int stripes_shift;
/* The size of this target / num. stripes */
sector_t stripe_width;
uint32_t chunk_size;
int chunk_size_shift;
/* Needed for handling events */
struct dm_target *ti;
/* Work struct used for triggering events*/
struct work_struct trigger_event;
struct stripe stripe[];
};
/*
* An event is triggered whenever a drive
* drops out of a stripe volume.
*/
static void trigger_event(struct work_struct *work)
{
struct stripe_c *sc = container_of(work, struct stripe_c,
trigger_event);
dm_table_event(sc->ti->table);
}
/*
* Parse a single <dev> <sector> pair
*/
static int get_stripe(struct dm_target *ti, struct stripe_c *sc,
unsigned int stripe, char **argv)
{
unsigned long long start;
char dummy;
int ret;
if (sscanf(argv[1], "%llu%c", &start, &dummy) != 1)
return -EINVAL;
ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
&sc->stripe[stripe].dev);
if (ret)
return ret;
sc->stripe[stripe].physical_start = start;
return 0;
}
/*
* Construct a striped mapping.
* <number of stripes> <chunk size> [<dev_path> <offset>]+
*/
static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
struct stripe_c *sc;
sector_t width, tmp_len;
uint32_t stripes;
uint32_t chunk_size;
int r;
unsigned int i;
if (argc < 2) {
ti->error = "Not enough arguments";
return -EINVAL;
}
if (kstrtouint(argv[0], 10, &stripes) || !stripes) {
ti->error = "Invalid stripe count";
return -EINVAL;
}
if (kstrtouint(argv[1], 10, &chunk_size) || !chunk_size) {
ti->error = "Invalid chunk_size";
return -EINVAL;
}
width = ti->len;
if (sector_div(width, stripes)) {
ti->error = "Target length not divisible by number of stripes";
return -EINVAL;
}
tmp_len = width;
if (sector_div(tmp_len, chunk_size)) {
ti->error = "Target length not divisible by chunk size";
return -EINVAL;
}
/*
* Do we have enough arguments for that many stripes ?
*/
if (argc != (2 + 2 * stripes)) {
ti->error = "Not enough destinations specified";
return -EINVAL;
}
sc = kmalloc(struct_size(sc, stripe, stripes), GFP_KERNEL);
if (!sc) {
ti->error = "Memory allocation for striped context failed";
return -ENOMEM;
}
INIT_WORK(&sc->trigger_event, trigger_event);
/* Set pointer to dm target; used in trigger_event */
sc->ti = ti;
sc->stripes = stripes;
sc->stripe_width = width;
if (stripes & (stripes - 1))
sc->stripes_shift = -1;
else
sc->stripes_shift = __ffs(stripes);
r = dm_set_target_max_io_len(ti, chunk_size);
if (r) {
kfree(sc);
return r;
}
ti->num_flush_bios = stripes;
ti->num_discard_bios = stripes;
ti->num_secure_erase_bios = stripes;
ti->num_write_zeroes_bios = stripes;
sc->chunk_size = chunk_size;
if (chunk_size & (chunk_size - 1))
sc->chunk_size_shift = -1;
else
sc->chunk_size_shift = __ffs(chunk_size);
/*
* Get the stripe destinations.
*/
for (i = 0; i < stripes; i++) {
argv += 2;
r = get_stripe(ti, sc, i, argv);
if (r < 0) {
ti->error = "Couldn't parse stripe destination";
while (i--)
dm_put_device(ti, sc->stripe[i].dev);
kfree(sc);
return r;
}
atomic_set(&(sc->stripe[i].error_count), 0);
}
ti->private = sc;
return 0;
}
static void stripe_dtr(struct dm_target *ti)
{
unsigned int i;
struct stripe_c *sc = ti->private;
for (i = 0; i < sc->stripes; i++)
dm_put_device(ti, sc->stripe[i].dev);
flush_work(&sc->trigger_event);
kfree(sc);
}
static void stripe_map_sector(struct stripe_c *sc, sector_t sector,
uint32_t *stripe, sector_t *result)
{
sector_t chunk = dm_target_offset(sc->ti, sector);
sector_t chunk_offset;
if (sc->chunk_size_shift < 0)
chunk_offset = sector_div(chunk, sc->chunk_size);
else {
chunk_offset = chunk & (sc->chunk_size - 1);
chunk >>= sc->chunk_size_shift;
}
if (sc->stripes_shift < 0)
*stripe = sector_div(chunk, sc->stripes);
else {
*stripe = chunk & (sc->stripes - 1);
chunk >>= sc->stripes_shift;
}
if (sc->chunk_size_shift < 0)
chunk *= sc->chunk_size;
else
chunk <<= sc->chunk_size_shift;
*result = chunk + chunk_offset;
}
static void stripe_map_range_sector(struct stripe_c *sc, sector_t sector,
uint32_t target_stripe, sector_t *result)
{
uint32_t stripe;
stripe_map_sector(sc, sector, &stripe, result);
if (stripe == target_stripe)
return;
/* round down */
sector = *result;
if (sc->chunk_size_shift < 0)
*result -= sector_div(sector, sc->chunk_size);
else
*result = sector & ~(sector_t)(sc->chunk_size - 1);
if (target_stripe < stripe)
*result += sc->chunk_size; /* next chunk */
}
static int stripe_map_range(struct stripe_c *sc, struct bio *bio,
uint32_t target_stripe)
{
sector_t begin, end;
stripe_map_range_sector(sc, bio->bi_iter.bi_sector,
target_stripe, &begin);
stripe_map_range_sector(sc, bio_end_sector(bio),
target_stripe, &end);
if (begin < end) {
bio_set_dev(bio, sc->stripe[target_stripe].dev->bdev);
bio->bi_iter.bi_sector = begin +
sc->stripe[target_stripe].physical_start;
bio->bi_iter.bi_size = to_bytes(end - begin);
return DM_MAPIO_REMAPPED;
}
/* The range doesn't map to the target stripe */
bio_endio(bio);
return DM_MAPIO_SUBMITTED;
}
static int stripe_map(struct dm_target *ti, struct bio *bio)
{
struct stripe_c *sc = ti->private;
uint32_t stripe;
unsigned int target_bio_nr;
if (bio->bi_opf & REQ_PREFLUSH) {
target_bio_nr = dm_bio_get_target_bio_nr(bio);
BUG_ON(target_bio_nr >= sc->stripes);
bio_set_dev(bio, sc->stripe[target_bio_nr].dev->bdev);
return DM_MAPIO_REMAPPED;
}
if (unlikely(bio_op(bio) == REQ_OP_DISCARD) ||
unlikely(bio_op(bio) == REQ_OP_SECURE_ERASE) ||
unlikely(bio_op(bio) == REQ_OP_WRITE_ZEROES)) {
target_bio_nr = dm_bio_get_target_bio_nr(bio);
BUG_ON(target_bio_nr >= sc->stripes);
return stripe_map_range(sc, bio, target_bio_nr);
}
stripe_map_sector(sc, bio->bi_iter.bi_sector,
&stripe, &bio->bi_iter.bi_sector);
bio->bi_iter.bi_sector += sc->stripe[stripe].physical_start;
bio_set_dev(bio, sc->stripe[stripe].dev->bdev);
return DM_MAPIO_REMAPPED;
}
#if IS_ENABLED(CONFIG_FS_DAX)
static struct dax_device *stripe_dax_pgoff(struct dm_target *ti, pgoff_t *pgoff)
{
struct stripe_c *sc = ti->private;
struct block_device *bdev;
sector_t dev_sector;
uint32_t stripe;
stripe_map_sector(sc, *pgoff * PAGE_SECTORS, &stripe, &dev_sector);
dev_sector += sc->stripe[stripe].physical_start;
bdev = sc->stripe[stripe].dev->bdev;
*pgoff = (get_start_sect(bdev) + dev_sector) >> PAGE_SECTORS_SHIFT;
return sc->stripe[stripe].dev->dax_dev;
}
static long stripe_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
long nr_pages, enum dax_access_mode mode, void **kaddr,
pfn_t *pfn)
{
struct dax_device *dax_dev = stripe_dax_pgoff(ti, &pgoff);
return dax_direct_access(dax_dev, pgoff, nr_pages, mode, kaddr, pfn);
}
static int stripe_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,
size_t nr_pages)
{
struct dax_device *dax_dev = stripe_dax_pgoff(ti, &pgoff);
return dax_zero_page_range(dax_dev, pgoff, nr_pages);
}
static size_t stripe_dax_recovery_write(struct dm_target *ti, pgoff_t pgoff,
void *addr, size_t bytes, struct iov_iter *i)
{
struct dax_device *dax_dev = stripe_dax_pgoff(ti, &pgoff);
return dax_recovery_write(dax_dev, pgoff, addr, bytes, i);
}
#else
#define stripe_dax_direct_access NULL
#define stripe_dax_zero_page_range NULL
#define stripe_dax_recovery_write NULL
#endif
/*
* Stripe status:
*
* INFO
* #stripes [stripe_name <stripe_name>] [group word count]
* [error count 'A|D' <error count 'A|D'>]
*
* TABLE
* #stripes [stripe chunk size]
* [stripe_name physical_start <stripe_name physical_start>]
*
*/
static void stripe_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
struct stripe_c *sc = ti->private;
unsigned int sz = 0;
unsigned int i;
switch (type) {
case STATUSTYPE_INFO:
DMEMIT("%d ", sc->stripes);
for (i = 0; i < sc->stripes; i++)
DMEMIT("%s ", sc->stripe[i].dev->name);
DMEMIT("1 ");
for (i = 0; i < sc->stripes; i++)
DMEMIT("%c", atomic_read(&(sc->stripe[i].error_count)) ? 'D' : 'A');
break;
case STATUSTYPE_TABLE:
DMEMIT("%d %llu", sc->stripes,
(unsigned long long)sc->chunk_size);
for (i = 0; i < sc->stripes; i++)
DMEMIT(" %s %llu", sc->stripe[i].dev->name,
(unsigned long long)sc->stripe[i].physical_start);
break;
case STATUSTYPE_IMA:
DMEMIT_TARGET_NAME_VERSION(ti->type);
DMEMIT(",stripes=%d,chunk_size=%llu", sc->stripes,
(unsigned long long)sc->chunk_size);
for (i = 0; i < sc->stripes; i++) {
DMEMIT(",stripe_%d_device_name=%s", i, sc->stripe[i].dev->name);
DMEMIT(",stripe_%d_physical_start=%llu", i,
(unsigned long long)sc->stripe[i].physical_start);
DMEMIT(",stripe_%d_status=%c", i,
atomic_read(&(sc->stripe[i].error_count)) ? 'D' : 'A');
}
DMEMIT(";");
break;
}
}
static int stripe_end_io(struct dm_target *ti, struct bio *bio,
blk_status_t *error)
{
unsigned int i;
char major_minor[16];
struct stripe_c *sc = ti->private;
if (!*error)
return DM_ENDIO_DONE; /* I/O complete */
if (bio->bi_opf & REQ_RAHEAD)
return DM_ENDIO_DONE;
if (*error == BLK_STS_NOTSUPP)
return DM_ENDIO_DONE;
memset(major_minor, 0, sizeof(major_minor));
sprintf(major_minor, "%d:%d", MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)));
/*
* Test to see which stripe drive triggered the event
* and increment error count for all stripes on that device.
* If the error count for a given device exceeds the threshold
* value we will no longer trigger any further events.
*/
for (i = 0; i < sc->stripes; i++)
if (!strcmp(sc->stripe[i].dev->name, major_minor)) {
atomic_inc(&(sc->stripe[i].error_count));
if (atomic_read(&(sc->stripe[i].error_count)) <
DM_IO_ERROR_THRESHOLD)
queue_work(dm_stripe_wq, &sc->trigger_event);
}
return DM_ENDIO_DONE;
}
static int stripe_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct stripe_c *sc = ti->private;
int ret = 0;
unsigned int i = 0;
do {
ret = fn(ti, sc->stripe[i].dev,
sc->stripe[i].physical_start,
sc->stripe_width, data);
} while (!ret && ++i < sc->stripes);
return ret;
}
static void stripe_io_hints(struct dm_target *ti,
struct queue_limits *limits)
{
struct stripe_c *sc = ti->private;
unsigned int chunk_size = sc->chunk_size << SECTOR_SHIFT;
blk_limits_io_min(limits, chunk_size);
blk_limits_io_opt(limits, chunk_size * sc->stripes);
}
static struct target_type stripe_target = {
.name = "striped",
.version = {1, 6, 0},
.features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_NOWAIT,
.module = THIS_MODULE,
.ctr = stripe_ctr,
.dtr = stripe_dtr,
.map = stripe_map,
.end_io = stripe_end_io,
.status = stripe_status,
.iterate_devices = stripe_iterate_devices,
.io_hints = stripe_io_hints,
.direct_access = stripe_dax_direct_access,
.dax_zero_page_range = stripe_dax_zero_page_range,
.dax_recovery_write = stripe_dax_recovery_write,
};
int __init dm_stripe_init(void)
{
int r;
dm_stripe_wq = alloc_workqueue("dm_stripe_wq", 0, 0);
if (!dm_stripe_wq)
return -ENOMEM;
r = dm_register_target(&stripe_target);
if (r < 0) {
destroy_workqueue(dm_stripe_wq);
DMWARN("target registration failed");
}
return r;
}
void dm_stripe_exit(void)
{
dm_unregister_target(&stripe_target);
destroy_workqueue(dm_stripe_wq);
}
| linux-master | drivers/md/dm-stripe.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2003 Sistina Software
* Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
*
* This file is released under the LGPL.
*/
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/dm-io.h>
#include <linux/dm-dirty-log.h>
#include <linux/device-mapper.h>
#define DM_MSG_PREFIX "dirty region log"
static LIST_HEAD(_log_types);
static DEFINE_SPINLOCK(_lock);
static struct dm_dirty_log_type *__find_dirty_log_type(const char *name)
{
struct dm_dirty_log_type *log_type;
list_for_each_entry(log_type, &_log_types, list)
if (!strcmp(name, log_type->name))
return log_type;
return NULL;
}
static struct dm_dirty_log_type *_get_dirty_log_type(const char *name)
{
struct dm_dirty_log_type *log_type;
spin_lock(&_lock);
log_type = __find_dirty_log_type(name);
if (log_type && !try_module_get(log_type->module))
log_type = NULL;
spin_unlock(&_lock);
return log_type;
}
/*
* get_type
* @type_name
*
* Attempt to retrieve the dm_dirty_log_type by name. If not already
* available, attempt to load the appropriate module.
*
* Log modules are named "dm-log-" followed by the 'type_name'.
* Modules may contain multiple types.
* This function will first try the module "dm-log-<type_name>",
* then truncate 'type_name' on the last '-' and try again.
*
* For example, if type_name was "clustered-disk", it would search
* 'dm-log-clustered-disk' then 'dm-log-clustered'.
*
* Returns: dirty_log_type* on success, NULL on failure
*/
static struct dm_dirty_log_type *get_type(const char *type_name)
{
char *p, *type_name_dup;
struct dm_dirty_log_type *log_type;
if (!type_name)
return NULL;
log_type = _get_dirty_log_type(type_name);
if (log_type)
return log_type;
type_name_dup = kstrdup(type_name, GFP_KERNEL);
if (!type_name_dup) {
DMWARN("No memory left to attempt log module load for \"%s\"",
type_name);
return NULL;
}
while (request_module("dm-log-%s", type_name_dup) ||
!(log_type = _get_dirty_log_type(type_name))) {
p = strrchr(type_name_dup, '-');
if (!p)
break;
p[0] = '\0';
}
if (!log_type)
DMWARN("Module for logging type \"%s\" not found.", type_name);
kfree(type_name_dup);
return log_type;
}
static void put_type(struct dm_dirty_log_type *type)
{
if (!type)
return;
spin_lock(&_lock);
if (!__find_dirty_log_type(type->name))
goto out;
module_put(type->module);
out:
spin_unlock(&_lock);
}
int dm_dirty_log_type_register(struct dm_dirty_log_type *type)
{
int r = 0;
spin_lock(&_lock);
if (!__find_dirty_log_type(type->name))
list_add(&type->list, &_log_types);
else
r = -EEXIST;
spin_unlock(&_lock);
return r;
}
EXPORT_SYMBOL(dm_dirty_log_type_register);
int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type)
{
spin_lock(&_lock);
if (!__find_dirty_log_type(type->name)) {
spin_unlock(&_lock);
return -EINVAL;
}
list_del(&type->list);
spin_unlock(&_lock);
return 0;
}
EXPORT_SYMBOL(dm_dirty_log_type_unregister);
struct dm_dirty_log *dm_dirty_log_create(const char *type_name,
struct dm_target *ti,
int (*flush_callback_fn)(struct dm_target *ti),
unsigned int argc, char **argv)
{
struct dm_dirty_log_type *type;
struct dm_dirty_log *log;
log = kmalloc(sizeof(*log), GFP_KERNEL);
if (!log)
return NULL;
type = get_type(type_name);
if (!type) {
kfree(log);
return NULL;
}
log->flush_callback_fn = flush_callback_fn;
log->type = type;
if (type->ctr(log, ti, argc, argv)) {
kfree(log);
put_type(type);
return NULL;
}
return log;
}
EXPORT_SYMBOL(dm_dirty_log_create);
void dm_dirty_log_destroy(struct dm_dirty_log *log)
{
log->type->dtr(log);
put_type(log->type);
kfree(log);
}
EXPORT_SYMBOL(dm_dirty_log_destroy);
/*
*---------------------------------------------------------------
* Persistent and core logs share a lot of their implementation.
* FIXME: need a reload method to be called from a resume
*---------------------------------------------------------------
*/
/*
* Magic for persistent mirrors: "MiRr"
*/
#define MIRROR_MAGIC 0x4D695272
/*
* The on-disk version of the metadata.
*/
#define MIRROR_DISK_VERSION 2
#define LOG_OFFSET 2
struct log_header_disk {
__le32 magic;
/*
* Simple, incrementing version. no backward
* compatibility.
*/
__le32 version;
__le64 nr_regions;
} __packed;
struct log_header_core {
uint32_t magic;
uint32_t version;
uint64_t nr_regions;
};
struct log_c {
struct dm_target *ti;
int touched_dirtied;
int touched_cleaned;
int flush_failed;
uint32_t region_size;
unsigned int region_count;
region_t sync_count;
unsigned int bitset_uint32_count;
uint32_t *clean_bits;
uint32_t *sync_bits;
uint32_t *recovering_bits; /* FIXME: this seems excessive */
int sync_search;
/* Resync flag */
enum sync {
DEFAULTSYNC, /* Synchronize if necessary */
NOSYNC, /* Devices known to be already in sync */
FORCESYNC, /* Force a sync to happen */
} sync;
struct dm_io_request io_req;
/*
* Disk log fields
*/
int log_dev_failed;
int log_dev_flush_failed;
struct dm_dev *log_dev;
struct log_header_core header;
struct dm_io_region header_location;
struct log_header_disk *disk_header;
};
/*
* The touched member needs to be updated every time we access
* one of the bitsets.
*/
static inline int log_test_bit(uint32_t *bs, unsigned int bit)
{
return test_bit_le(bit, bs) ? 1 : 0;
}
static inline void log_set_bit(struct log_c *l,
uint32_t *bs, unsigned int bit)
{
__set_bit_le(bit, bs);
l->touched_cleaned = 1;
}
static inline void log_clear_bit(struct log_c *l,
uint32_t *bs, unsigned int bit)
{
__clear_bit_le(bit, bs);
l->touched_dirtied = 1;
}
/*
*---------------------------------------------------------------
* Header IO
*--------------------------------------------------------------
*/
static void header_to_disk(struct log_header_core *core, struct log_header_disk *disk)
{
disk->magic = cpu_to_le32(core->magic);
disk->version = cpu_to_le32(core->version);
disk->nr_regions = cpu_to_le64(core->nr_regions);
}
static void header_from_disk(struct log_header_core *core, struct log_header_disk *disk)
{
core->magic = le32_to_cpu(disk->magic);
core->version = le32_to_cpu(disk->version);
core->nr_regions = le64_to_cpu(disk->nr_regions);
}
static int rw_header(struct log_c *lc, enum req_op op)
{
lc->io_req.bi_opf = op;
return dm_io(&lc->io_req, 1, &lc->header_location, NULL);
}
static int flush_header(struct log_c *lc)
{
struct dm_io_region null_location = {
.bdev = lc->header_location.bdev,
.sector = 0,
.count = 0,
};
lc->io_req.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
return dm_io(&lc->io_req, 1, &null_location, NULL);
}
static int read_header(struct log_c *log)
{
int r;
r = rw_header(log, REQ_OP_READ);
if (r)
return r;
header_from_disk(&log->header, log->disk_header);
/* New log required? */
if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
log->header.magic = MIRROR_MAGIC;
log->header.version = MIRROR_DISK_VERSION;
log->header.nr_regions = 0;
}
#ifdef __LITTLE_ENDIAN
if (log->header.version == 1)
log->header.version = 2;
#endif
if (log->header.version != MIRROR_DISK_VERSION) {
DMWARN("incompatible disk log version");
return -EINVAL;
}
return 0;
}
static int _check_region_size(struct dm_target *ti, uint32_t region_size)
{
if (region_size < 2 || region_size > ti->len)
return 0;
if (!is_power_of_2(region_size))
return 0;
return 1;
}
/*
*--------------------------------------------------------------
* core log constructor/destructor
*
* argv contains region_size followed optionally by [no]sync
*--------------------------------------------------------------
*/
#define BYTE_SHIFT 3
static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
unsigned int argc, char **argv,
struct dm_dev *dev)
{
enum sync sync = DEFAULTSYNC;
struct log_c *lc;
uint32_t region_size;
unsigned int region_count;
size_t bitset_size, buf_size;
int r;
char dummy;
if (argc < 1 || argc > 2) {
DMWARN("wrong number of arguments to dirty region log");
return -EINVAL;
}
if (argc > 1) {
if (!strcmp(argv[1], "sync"))
sync = FORCESYNC;
else if (!strcmp(argv[1], "nosync"))
sync = NOSYNC;
else {
DMWARN("unrecognised sync argument to dirty region log: %s", argv[1]);
return -EINVAL;
}
}
if (sscanf(argv[0], "%u%c", ®ion_size, &dummy) != 1 ||
!_check_region_size(ti, region_size)) {
DMWARN("invalid region size %s", argv[0]);
return -EINVAL;
}
region_count = dm_sector_div_up(ti->len, region_size);
lc = kmalloc(sizeof(*lc), GFP_KERNEL);
if (!lc) {
DMWARN("couldn't allocate core log");
return -ENOMEM;
}
lc->ti = ti;
lc->touched_dirtied = 0;
lc->touched_cleaned = 0;
lc->flush_failed = 0;
lc->region_size = region_size;
lc->region_count = region_count;
lc->sync = sync;
/*
* Work out how many "unsigned long"s we need to hold the bitset.
*/
bitset_size = dm_round_up(region_count, BITS_PER_LONG);
bitset_size >>= BYTE_SHIFT;
lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);
/*
* Disk log?
*/
if (!dev) {
lc->clean_bits = vmalloc(bitset_size);
if (!lc->clean_bits) {
DMWARN("couldn't allocate clean bitset");
kfree(lc);
return -ENOMEM;
}
lc->disk_header = NULL;
} else {
lc->log_dev = dev;
lc->log_dev_failed = 0;
lc->log_dev_flush_failed = 0;
lc->header_location.bdev = lc->log_dev->bdev;
lc->header_location.sector = 0;
/*
* Buffer holds both header and bitset.
*/
buf_size =
dm_round_up((LOG_OFFSET << SECTOR_SHIFT) + bitset_size,
bdev_logical_block_size(lc->header_location.bdev));
if (buf_size > bdev_nr_bytes(dev->bdev)) {
DMWARN("log device %s too small: need %llu bytes",
dev->name, (unsigned long long)buf_size);
kfree(lc);
return -EINVAL;
}
lc->header_location.count = buf_size >> SECTOR_SHIFT;
lc->io_req.mem.type = DM_IO_VMA;
lc->io_req.notify.fn = NULL;
lc->io_req.client = dm_io_client_create();
if (IS_ERR(lc->io_req.client)) {
r = PTR_ERR(lc->io_req.client);
DMWARN("couldn't allocate disk io client");
kfree(lc);
return r;
}
lc->disk_header = vmalloc(buf_size);
if (!lc->disk_header) {
DMWARN("couldn't allocate disk log buffer");
dm_io_client_destroy(lc->io_req.client);
kfree(lc);
return -ENOMEM;
}
lc->io_req.mem.ptr.vma = lc->disk_header;
lc->clean_bits = (void *)lc->disk_header +
(LOG_OFFSET << SECTOR_SHIFT);
}
memset(lc->clean_bits, -1, bitset_size);
lc->sync_bits = vmalloc(bitset_size);
if (!lc->sync_bits) {
DMWARN("couldn't allocate sync bitset");
if (!dev)
vfree(lc->clean_bits);
else
dm_io_client_destroy(lc->io_req.client);
vfree(lc->disk_header);
kfree(lc);
return -ENOMEM;
}
memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size);
lc->sync_count = (sync == NOSYNC) ? region_count : 0;
lc->recovering_bits = vzalloc(bitset_size);
if (!lc->recovering_bits) {
DMWARN("couldn't allocate sync bitset");
vfree(lc->sync_bits);
if (!dev)
vfree(lc->clean_bits);
else
dm_io_client_destroy(lc->io_req.client);
vfree(lc->disk_header);
kfree(lc);
return -ENOMEM;
}
lc->sync_search = 0;
log->context = lc;
return 0;
}
static int core_ctr(struct dm_dirty_log *log, struct dm_target *ti,
unsigned int argc, char **argv)
{
return create_log_context(log, ti, argc, argv, NULL);
}
static void destroy_log_context(struct log_c *lc)
{
vfree(lc->sync_bits);
vfree(lc->recovering_bits);
kfree(lc);
}
static void core_dtr(struct dm_dirty_log *log)
{
struct log_c *lc = log->context;
vfree(lc->clean_bits);
destroy_log_context(lc);
}
/*
*---------------------------------------------------------------------
* disk log constructor/destructor
*
* argv contains log_device region_size followed optionally by [no]sync
*---------------------------------------------------------------------
*/
static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti,
unsigned int argc, char **argv)
{
int r;
struct dm_dev *dev;
if (argc < 2 || argc > 3) {
DMWARN("wrong number of arguments to disk dirty region log");
return -EINVAL;
}
r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &dev);
if (r)
return r;
r = create_log_context(log, ti, argc - 1, argv + 1, dev);
if (r) {
dm_put_device(ti, dev);
return r;
}
return 0;
}
static void disk_dtr(struct dm_dirty_log *log)
{
struct log_c *lc = log->context;
dm_put_device(lc->ti, lc->log_dev);
vfree(lc->disk_header);
dm_io_client_destroy(lc->io_req.client);
destroy_log_context(lc);
}
static void fail_log_device(struct log_c *lc)
{
if (lc->log_dev_failed)
return;
lc->log_dev_failed = 1;
dm_table_event(lc->ti->table);
}
static int disk_resume(struct dm_dirty_log *log)
{
int r;
unsigned int i;
struct log_c *lc = log->context;
size_t size = lc->bitset_uint32_count * sizeof(uint32_t);
/* read the disk header */
r = read_header(lc);
if (r) {
DMWARN("%s: Failed to read header on dirty region log device",
lc->log_dev->name);
fail_log_device(lc);
/*
* If the log device cannot be read, we must assume
* all regions are out-of-sync. If we simply return
* here, the state will be uninitialized and could
* lead us to return 'in-sync' status for regions
* that are actually 'out-of-sync'.
*/
lc->header.nr_regions = 0;
}
/* set or clear any new bits -- device has grown */
if (lc->sync == NOSYNC)
for (i = lc->header.nr_regions; i < lc->region_count; i++)
/* FIXME: amazingly inefficient */
log_set_bit(lc, lc->clean_bits, i);
else
for (i = lc->header.nr_regions; i < lc->region_count; i++)
/* FIXME: amazingly inefficient */
log_clear_bit(lc, lc->clean_bits, i);
/* clear any old bits -- device has shrunk */
for (i = lc->region_count; i % BITS_PER_LONG; i++)
log_clear_bit(lc, lc->clean_bits, i);
/* copy clean across to sync */
memcpy(lc->sync_bits, lc->clean_bits, size);
lc->sync_count = memweight(lc->clean_bits,
lc->bitset_uint32_count * sizeof(uint32_t));
lc->sync_search = 0;
/* set the correct number of regions in the header */
lc->header.nr_regions = lc->region_count;
header_to_disk(&lc->header, lc->disk_header);
/* write the new header */
r = rw_header(lc, REQ_OP_WRITE);
if (!r) {
r = flush_header(lc);
if (r)
lc->log_dev_flush_failed = 1;
}
if (r) {
DMWARN("%s: Failed to write header on dirty region log device",
lc->log_dev->name);
fail_log_device(lc);
}
return r;
}
static uint32_t core_get_region_size(struct dm_dirty_log *log)
{
struct log_c *lc = log->context;
return lc->region_size;
}
static int core_resume(struct dm_dirty_log *log)
{
struct log_c *lc = log->context;
lc->sync_search = 0;
return 0;
}
static int core_is_clean(struct dm_dirty_log *log, region_t region)
{
struct log_c *lc = log->context;
return log_test_bit(lc->clean_bits, region);
}
static int core_in_sync(struct dm_dirty_log *log, region_t region, int block)
{
struct log_c *lc = log->context;
return log_test_bit(lc->sync_bits, region);
}
static int core_flush(struct dm_dirty_log *log)
{
/* no op */
return 0;
}
static int disk_flush(struct dm_dirty_log *log)
{
int r, i;
struct log_c *lc = log->context;
/* only write if the log has changed */
if (!lc->touched_cleaned && !lc->touched_dirtied)
return 0;
if (lc->touched_cleaned && log->flush_callback_fn &&
log->flush_callback_fn(lc->ti)) {
/*
* At this point it is impossible to determine which
* regions are clean and which are dirty (without
* re-reading the log off disk). So mark all of them
* dirty.
*/
lc->flush_failed = 1;
for (i = 0; i < lc->region_count; i++)
log_clear_bit(lc, lc->clean_bits, i);
}
r = rw_header(lc, REQ_OP_WRITE);
if (r)
fail_log_device(lc);
else {
if (lc->touched_dirtied) {
r = flush_header(lc);
if (r) {
lc->log_dev_flush_failed = 1;
fail_log_device(lc);
} else
lc->touched_dirtied = 0;
}
lc->touched_cleaned = 0;
}
return r;
}
static void core_mark_region(struct dm_dirty_log *log, region_t region)
{
struct log_c *lc = log->context;
log_clear_bit(lc, lc->clean_bits, region);
}
static void core_clear_region(struct dm_dirty_log *log, region_t region)
{
struct log_c *lc = log->context;
if (likely(!lc->flush_failed))
log_set_bit(lc, lc->clean_bits, region);
}
static int core_get_resync_work(struct dm_dirty_log *log, region_t *region)
{
struct log_c *lc = log->context;
if (lc->sync_search >= lc->region_count)
return 0;
do {
*region = find_next_zero_bit_le(lc->sync_bits,
lc->region_count,
lc->sync_search);
lc->sync_search = *region + 1;
if (*region >= lc->region_count)
return 0;
} while (log_test_bit(lc->recovering_bits, *region));
log_set_bit(lc, lc->recovering_bits, *region);
return 1;
}
static void core_set_region_sync(struct dm_dirty_log *log, region_t region,
int in_sync)
{
struct log_c *lc = log->context;
log_clear_bit(lc, lc->recovering_bits, region);
if (in_sync) {
log_set_bit(lc, lc->sync_bits, region);
lc->sync_count++;
} else if (log_test_bit(lc->sync_bits, region)) {
lc->sync_count--;
log_clear_bit(lc, lc->sync_bits, region);
}
}
static region_t core_get_sync_count(struct dm_dirty_log *log)
{
struct log_c *lc = log->context;
return lc->sync_count;
}
#define DMEMIT_SYNC \
do { \
if (lc->sync != DEFAULTSYNC) \
DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : ""); \
} while (0)
static int core_status(struct dm_dirty_log *log, status_type_t status,
char *result, unsigned int maxlen)
{
int sz = 0;
struct log_c *lc = log->context;
switch (status) {
case STATUSTYPE_INFO:
DMEMIT("1 %s", log->type->name);
break;
case STATUSTYPE_TABLE:
DMEMIT("%s %u %u ", log->type->name,
lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size);
DMEMIT_SYNC;
break;
case STATUSTYPE_IMA:
*result = '\0';
break;
}
return sz;
}
static int disk_status(struct dm_dirty_log *log, status_type_t status,
char *result, unsigned int maxlen)
{
int sz = 0;
struct log_c *lc = log->context;
switch (status) {
case STATUSTYPE_INFO:
DMEMIT("3 %s %s %c", log->type->name, lc->log_dev->name,
lc->log_dev_flush_failed ? 'F' :
lc->log_dev_failed ? 'D' :
'A');
break;
case STATUSTYPE_TABLE:
DMEMIT("%s %u %s %u ", log->type->name,
lc->sync == DEFAULTSYNC ? 2 : 3, lc->log_dev->name,
lc->region_size);
DMEMIT_SYNC;
break;
case STATUSTYPE_IMA:
*result = '\0';
break;
}
return sz;
}
static struct dm_dirty_log_type _core_type = {
.name = "core",
.module = THIS_MODULE,
.ctr = core_ctr,
.dtr = core_dtr,
.resume = core_resume,
.get_region_size = core_get_region_size,
.is_clean = core_is_clean,
.in_sync = core_in_sync,
.flush = core_flush,
.mark_region = core_mark_region,
.clear_region = core_clear_region,
.get_resync_work = core_get_resync_work,
.set_region_sync = core_set_region_sync,
.get_sync_count = core_get_sync_count,
.status = core_status,
};
static struct dm_dirty_log_type _disk_type = {
.name = "disk",
.module = THIS_MODULE,
.ctr = disk_ctr,
.dtr = disk_dtr,
.postsuspend = disk_flush,
.resume = disk_resume,
.get_region_size = core_get_region_size,
.is_clean = core_is_clean,
.in_sync = core_in_sync,
.flush = disk_flush,
.mark_region = core_mark_region,
.clear_region = core_clear_region,
.get_resync_work = core_get_resync_work,
.set_region_sync = core_set_region_sync,
.get_sync_count = core_get_sync_count,
.status = disk_status,
};
static int __init dm_dirty_log_init(void)
{
int r;
r = dm_dirty_log_type_register(&_core_type);
if (r)
DMWARN("couldn't register core log");
r = dm_dirty_log_type_register(&_disk_type);
if (r) {
DMWARN("couldn't register disk type");
dm_dirty_log_type_unregister(&_core_type);
}
return r;
}
static void __exit dm_dirty_log_exit(void)
{
dm_dirty_log_type_unregister(&_disk_type);
dm_dirty_log_type_unregister(&_core_type);
}
module_init(dm_dirty_log_init);
module_exit(dm_dirty_log_exit);
MODULE_DESCRIPTION(DM_NAME " dirty region log");
MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-log.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2006-2009 Red Hat, Inc.
*
* This file is released under the LGPL.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <linux/workqueue.h>
#include <linux/connector.h>
#include <linux/device-mapper.h>
#include <linux/dm-log-userspace.h>
#include "dm-log-userspace-transfer.h"
static uint32_t dm_ulog_seq;
/*
* Netlink/Connector is an unreliable protocol. How long should
* we wait for a response before assuming it was lost and retrying?
* (If we do receive a response after this time, it will be discarded
* and the response to the resent request will be waited for.
*/
#define DM_ULOG_RETRY_TIMEOUT (15 * HZ)
/*
* Pre-allocated space for speed
*/
#define DM_ULOG_PREALLOCED_SIZE 512
static struct cn_msg *prealloced_cn_msg;
static struct dm_ulog_request *prealloced_ulog_tfr;
static struct cb_id ulog_cn_id = {
.idx = CN_IDX_DM,
.val = CN_VAL_DM_USERSPACE_LOG
};
static DEFINE_MUTEX(dm_ulog_lock);
struct receiving_pkg {
struct list_head list;
struct completion complete;
uint32_t seq;
int error;
size_t *data_size;
char *data;
};
static DEFINE_SPINLOCK(receiving_list_lock);
static struct list_head receiving_list;
static int dm_ulog_sendto_server(struct dm_ulog_request *tfr)
{
int r;
struct cn_msg *msg = prealloced_cn_msg;
memset(msg, 0, sizeof(struct cn_msg));
msg->id.idx = ulog_cn_id.idx;
msg->id.val = ulog_cn_id.val;
msg->ack = 0;
msg->seq = tfr->seq;
msg->len = sizeof(struct dm_ulog_request) + tfr->data_size;
r = cn_netlink_send(msg, 0, 0, gfp_any());
return r;
}
/*
* Parameters for this function can be either msg or tfr, but not
* both. This function fills in the reply for a waiting request.
* If just msg is given, then the reply is simply an ACK from userspace
* that the request was received.
*
* Returns: 0 on success, -ENOENT on failure
*/
static int fill_pkg(struct cn_msg *msg, struct dm_ulog_request *tfr)
{
uint32_t rtn_seq = (msg) ? msg->seq : (tfr) ? tfr->seq : 0;
struct receiving_pkg *pkg;
/*
* The 'receiving_pkg' entries in this list are statically
* allocated on the stack in 'dm_consult_userspace'.
* Each process that is waiting for a reply from the user
* space server will have an entry in this list.
*
* We are safe to do it this way because the stack space
* is unique to each process, but still addressable by
* other processes.
*/
list_for_each_entry(pkg, &receiving_list, list) {
if (rtn_seq != pkg->seq)
continue;
if (msg) {
pkg->error = -msg->ack;
/*
* If we are trying again, we will need to know our
* storage capacity. Otherwise, along with the
* error code, we make explicit that we have no data.
*/
if (pkg->error != -EAGAIN)
*(pkg->data_size) = 0;
} else if (tfr->data_size > *(pkg->data_size)) {
DMERR("Insufficient space to receive package [%u] (%u vs %zu)",
tfr->request_type, tfr->data_size, *(pkg->data_size));
*(pkg->data_size) = 0;
pkg->error = -ENOSPC;
} else {
pkg->error = tfr->error;
memcpy(pkg->data, tfr->data, tfr->data_size);
*(pkg->data_size) = tfr->data_size;
}
complete(&pkg->complete);
return 0;
}
return -ENOENT;
}
/*
* This is the connector callback that delivers data
* that was sent from userspace.
*/
static void cn_ulog_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
{
struct dm_ulog_request *tfr = (struct dm_ulog_request *)(msg + 1);
if (!capable(CAP_SYS_ADMIN))
return;
spin_lock(&receiving_list_lock);
if (msg->len == 0)
fill_pkg(msg, NULL);
else if (msg->len < sizeof(*tfr))
DMERR("Incomplete message received (expected %u, got %u): [%u]",
(unsigned int)sizeof(*tfr), msg->len, msg->seq);
else
fill_pkg(NULL, tfr);
spin_unlock(&receiving_list_lock);
}
/**
* dm_consult_userspace
* @uuid: log's universal unique identifier (must be DM_UUID_LEN in size)
* @luid: log's local unique identifier
* @request_type: found in include/linux/dm-log-userspace.h
* @data: data to tx to the server
* @data_size: size of data in bytes
* @rdata: place to put return data from server
* @rdata_size: value-result (amount of space given/amount of space used)
*
* rdata_size is undefined on failure.
*
* Memory used to communicate with userspace is zero'ed
* before populating to ensure that no unwanted bits leak
* from kernel space to user-space. All userspace log communications
* between kernel and user space go through this function.
*
* Returns: 0 on success, -EXXX on failure
**/
int dm_consult_userspace(const char *uuid, uint64_t luid, int request_type,
char *data, size_t data_size,
char *rdata, size_t *rdata_size)
{
int r = 0;
unsigned long tmo;
size_t dummy = 0;
int overhead_size = sizeof(struct dm_ulog_request) + sizeof(struct cn_msg);
struct dm_ulog_request *tfr = prealloced_ulog_tfr;
struct receiving_pkg pkg;
/*
* Given the space needed to hold the 'struct cn_msg' and
* 'struct dm_ulog_request' - do we have enough payload
* space remaining?
*/
if (data_size > (DM_ULOG_PREALLOCED_SIZE - overhead_size)) {
DMINFO("Size of tfr exceeds preallocated size");
return -EINVAL;
}
if (!rdata_size)
rdata_size = &dummy;
resend:
/*
* We serialize the sending of requests so we can
* use the preallocated space.
*/
mutex_lock(&dm_ulog_lock);
memset(tfr, 0, DM_ULOG_PREALLOCED_SIZE - sizeof(struct cn_msg));
memcpy(tfr->uuid, uuid, DM_UUID_LEN);
tfr->version = DM_ULOG_REQUEST_VERSION;
tfr->luid = luid;
tfr->seq = dm_ulog_seq++;
/*
* Must be valid request type (all other bits set to
* zero). This reserves other bits for possible future
* use.
*/
tfr->request_type = request_type & DM_ULOG_REQUEST_MASK;
tfr->data_size = data_size;
if (data && data_size)
memcpy(tfr->data, data, data_size);
memset(&pkg, 0, sizeof(pkg));
init_completion(&pkg.complete);
pkg.seq = tfr->seq;
pkg.data_size = rdata_size;
pkg.data = rdata;
spin_lock(&receiving_list_lock);
list_add(&(pkg.list), &receiving_list);
spin_unlock(&receiving_list_lock);
r = dm_ulog_sendto_server(tfr);
mutex_unlock(&dm_ulog_lock);
if (r) {
DMERR("Unable to send log request [%u] to userspace: %d",
request_type, r);
spin_lock(&receiving_list_lock);
list_del_init(&(pkg.list));
spin_unlock(&receiving_list_lock);
goto out;
}
tmo = wait_for_completion_timeout(&(pkg.complete), DM_ULOG_RETRY_TIMEOUT);
spin_lock(&receiving_list_lock);
list_del_init(&(pkg.list));
spin_unlock(&receiving_list_lock);
if (!tmo) {
DMWARN("[%s] Request timed out: [%u/%u] - retrying",
(strlen(uuid) > 8) ?
(uuid + (strlen(uuid) - 8)) : (uuid),
request_type, pkg.seq);
goto resend;
}
r = pkg.error;
if (r == -EAGAIN)
goto resend;
out:
return r;
}
int dm_ulog_tfr_init(void)
{
int r;
void *prealloced;
INIT_LIST_HEAD(&receiving_list);
prealloced = kmalloc(DM_ULOG_PREALLOCED_SIZE, GFP_KERNEL);
if (!prealloced)
return -ENOMEM;
prealloced_cn_msg = prealloced;
prealloced_ulog_tfr = prealloced + sizeof(struct cn_msg);
r = cn_add_callback(&ulog_cn_id, "dmlogusr", cn_ulog_callback);
if (r) {
kfree(prealloced_cn_msg);
return r;
}
return 0;
}
void dm_ulog_tfr_exit(void)
{
cn_del_callback(&ulog_cn_id);
kfree(prealloced_cn_msg);
}
| linux-master | drivers/md/dm-log-userspace-transfer.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
* Copyright (C) 2004 - 2006 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
#include "dm-core.h"
#include "dm-ima.h"
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/miscdevice.h>
#include <linux/sched/mm.h>
#include <linux/init.h>
#include <linux/wait.h>
#include <linux/slab.h>
#include <linux/rbtree.h>
#include <linux/dm-ioctl.h>
#include <linux/hdreg.h>
#include <linux/compat.h>
#include <linux/nospec.h>
#include <linux/uaccess.h>
#include <linux/ima.h>
#define DM_MSG_PREFIX "ioctl"
#define DM_DRIVER_EMAIL "[email protected]"
struct dm_file {
/*
* poll will wait until the global event number is greater than
* this value.
*/
volatile unsigned int global_event_nr;
};
/*
*---------------------------------------------------------------
* The ioctl interface needs to be able to look up devices by
* name or uuid.
*---------------------------------------------------------------
*/
struct hash_cell {
struct rb_node name_node;
struct rb_node uuid_node;
bool name_set;
bool uuid_set;
char *name;
char *uuid;
struct mapped_device *md;
struct dm_table *new_map;
};
struct vers_iter {
size_t param_size;
struct dm_target_versions *vers, *old_vers;
char *end;
uint32_t flags;
};
static struct rb_root name_rb_tree = RB_ROOT;
static struct rb_root uuid_rb_tree = RB_ROOT;
static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred);
/*
* Guards access to both hash tables.
*/
static DECLARE_RWSEM(_hash_lock);
/*
* Protects use of mdptr to obtain hash cell name and uuid from mapped device.
*/
static DEFINE_MUTEX(dm_hash_cells_mutex);
static void dm_hash_exit(void)
{
dm_hash_remove_all(false, false, false);
}
/*
*---------------------------------------------------------------
* Code for looking up a device by name
*---------------------------------------------------------------
*/
static struct hash_cell *__get_name_cell(const char *str)
{
struct rb_node *n = name_rb_tree.rb_node;
while (n) {
struct hash_cell *hc = container_of(n, struct hash_cell, name_node);
int c;
c = strcmp(hc->name, str);
if (!c) {
dm_get(hc->md);
return hc;
}
n = c >= 0 ? n->rb_left : n->rb_right;
}
return NULL;
}
static struct hash_cell *__get_uuid_cell(const char *str)
{
struct rb_node *n = uuid_rb_tree.rb_node;
while (n) {
struct hash_cell *hc = container_of(n, struct hash_cell, uuid_node);
int c;
c = strcmp(hc->uuid, str);
if (!c) {
dm_get(hc->md);
return hc;
}
n = c >= 0 ? n->rb_left : n->rb_right;
}
return NULL;
}
static void __unlink_name(struct hash_cell *hc)
{
if (hc->name_set) {
hc->name_set = false;
rb_erase(&hc->name_node, &name_rb_tree);
}
}
static void __unlink_uuid(struct hash_cell *hc)
{
if (hc->uuid_set) {
hc->uuid_set = false;
rb_erase(&hc->uuid_node, &uuid_rb_tree);
}
}
static void __link_name(struct hash_cell *new_hc)
{
struct rb_node **n, *parent;
__unlink_name(new_hc);
new_hc->name_set = true;
n = &name_rb_tree.rb_node;
parent = NULL;
while (*n) {
struct hash_cell *hc = container_of(*n, struct hash_cell, name_node);
int c;
c = strcmp(hc->name, new_hc->name);
BUG_ON(!c);
parent = *n;
n = c >= 0 ? &hc->name_node.rb_left : &hc->name_node.rb_right;
}
rb_link_node(&new_hc->name_node, parent, n);
rb_insert_color(&new_hc->name_node, &name_rb_tree);
}
static void __link_uuid(struct hash_cell *new_hc)
{
struct rb_node **n, *parent;
__unlink_uuid(new_hc);
new_hc->uuid_set = true;
n = &uuid_rb_tree.rb_node;
parent = NULL;
while (*n) {
struct hash_cell *hc = container_of(*n, struct hash_cell, uuid_node);
int c;
c = strcmp(hc->uuid, new_hc->uuid);
BUG_ON(!c);
parent = *n;
n = c > 0 ? &hc->uuid_node.rb_left : &hc->uuid_node.rb_right;
}
rb_link_node(&new_hc->uuid_node, parent, n);
rb_insert_color(&new_hc->uuid_node, &uuid_rb_tree);
}
static struct hash_cell *__get_dev_cell(uint64_t dev)
{
struct mapped_device *md;
struct hash_cell *hc;
md = dm_get_md(huge_decode_dev(dev));
if (!md)
return NULL;
hc = dm_get_mdptr(md);
if (!hc) {
dm_put(md);
return NULL;
}
return hc;
}
/*
*---------------------------------------------------------------
* Inserting, removing and renaming a device.
*---------------------------------------------------------------
*/
static struct hash_cell *alloc_cell(const char *name, const char *uuid,
struct mapped_device *md)
{
struct hash_cell *hc;
hc = kmalloc(sizeof(*hc), GFP_KERNEL);
if (!hc)
return NULL;
hc->name = kstrdup(name, GFP_KERNEL);
if (!hc->name) {
kfree(hc);
return NULL;
}
if (!uuid)
hc->uuid = NULL;
else {
hc->uuid = kstrdup(uuid, GFP_KERNEL);
if (!hc->uuid) {
kfree(hc->name);
kfree(hc);
return NULL;
}
}
hc->name_set = hc->uuid_set = false;
hc->md = md;
hc->new_map = NULL;
return hc;
}
static void free_cell(struct hash_cell *hc)
{
if (hc) {
kfree(hc->name);
kfree(hc->uuid);
kfree(hc);
}
}
/*
* The kdev_t and uuid of a device can never change once it is
* initially inserted.
*/
static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
{
struct hash_cell *cell, *hc;
/*
* Allocate the new cells.
*/
cell = alloc_cell(name, uuid, md);
if (!cell)
return -ENOMEM;
/*
* Insert the cell into both hash tables.
*/
down_write(&_hash_lock);
hc = __get_name_cell(name);
if (hc) {
dm_put(hc->md);
goto bad;
}
__link_name(cell);
if (uuid) {
hc = __get_uuid_cell(uuid);
if (hc) {
__unlink_name(cell);
dm_put(hc->md);
goto bad;
}
__link_uuid(cell);
}
dm_get(md);
mutex_lock(&dm_hash_cells_mutex);
dm_set_mdptr(md, cell);
mutex_unlock(&dm_hash_cells_mutex);
up_write(&_hash_lock);
return 0;
bad:
up_write(&_hash_lock);
free_cell(cell);
return -EBUSY;
}
static struct dm_table *__hash_remove(struct hash_cell *hc)
{
struct dm_table *table;
int srcu_idx;
lockdep_assert_held(&_hash_lock);
/* remove from the dev trees */
__unlink_name(hc);
__unlink_uuid(hc);
mutex_lock(&dm_hash_cells_mutex);
dm_set_mdptr(hc->md, NULL);
mutex_unlock(&dm_hash_cells_mutex);
table = dm_get_live_table(hc->md, &srcu_idx);
if (table)
dm_table_event(table);
dm_put_live_table(hc->md, srcu_idx);
table = NULL;
if (hc->new_map)
table = hc->new_map;
dm_put(hc->md);
free_cell(hc);
return table;
}
static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred)
{
int dev_skipped;
struct rb_node *n;
struct hash_cell *hc;
struct mapped_device *md;
struct dm_table *t;
retry:
dev_skipped = 0;
down_write(&_hash_lock);
for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {
hc = container_of(n, struct hash_cell, name_node);
md = hc->md;
dm_get(md);
if (keep_open_devices &&
dm_lock_for_deletion(md, mark_deferred, only_deferred)) {
dm_put(md);
dev_skipped++;
continue;
}
t = __hash_remove(hc);
up_write(&_hash_lock);
if (t) {
dm_sync_table(md);
dm_table_destroy(t);
}
dm_ima_measure_on_device_remove(md, true);
dm_put(md);
if (likely(keep_open_devices))
dm_destroy(md);
else
dm_destroy_immediate(md);
/*
* Some mapped devices may be using other mapped
* devices, so repeat until we make no further
* progress. If a new mapped device is created
* here it will also get removed.
*/
goto retry;
}
up_write(&_hash_lock);
if (dev_skipped)
DMWARN("remove_all left %d open device(s)", dev_skipped);
}
/*
* Set the uuid of a hash_cell that isn't already set.
*/
static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
{
mutex_lock(&dm_hash_cells_mutex);
hc->uuid = new_uuid;
mutex_unlock(&dm_hash_cells_mutex);
__link_uuid(hc);
}
/*
* Changes the name of a hash_cell and returns the old name for
* the caller to free.
*/
static char *__change_cell_name(struct hash_cell *hc, char *new_name)
{
char *old_name;
/*
* Rename and move the name cell.
*/
__unlink_name(hc);
old_name = hc->name;
mutex_lock(&dm_hash_cells_mutex);
hc->name = new_name;
mutex_unlock(&dm_hash_cells_mutex);
__link_name(hc);
return old_name;
}
static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
const char *new)
{
char *new_data, *old_name = NULL;
struct hash_cell *hc;
struct dm_table *table;
struct mapped_device *md;
unsigned int change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
int srcu_idx;
/*
* duplicate new.
*/
new_data = kstrdup(new, GFP_KERNEL);
if (!new_data)
return ERR_PTR(-ENOMEM);
down_write(&_hash_lock);
/*
* Is new free ?
*/
if (change_uuid)
hc = __get_uuid_cell(new);
else
hc = __get_name_cell(new);
if (hc) {
DMERR("Unable to change %s on mapped device %s to one that already exists: %s",
change_uuid ? "uuid" : "name",
param->name, new);
dm_put(hc->md);
up_write(&_hash_lock);
kfree(new_data);
return ERR_PTR(-EBUSY);
}
/*
* Is there such a device as 'old' ?
*/
hc = __get_name_cell(param->name);
if (!hc) {
DMERR("Unable to rename non-existent device, %s to %s%s",
param->name, change_uuid ? "uuid " : "", new);
up_write(&_hash_lock);
kfree(new_data);
return ERR_PTR(-ENXIO);
}
/*
* Does this device already have a uuid?
*/
if (change_uuid && hc->uuid) {
DMERR("Unable to change uuid of mapped device %s to %s "
"because uuid is already set to %s",
param->name, new, hc->uuid);
dm_put(hc->md);
up_write(&_hash_lock);
kfree(new_data);
return ERR_PTR(-EINVAL);
}
if (change_uuid)
__set_cell_uuid(hc, new_data);
else
old_name = __change_cell_name(hc, new_data);
/*
* Wake up any dm event waiters.
*/
table = dm_get_live_table(hc->md, &srcu_idx);
if (table)
dm_table_event(table);
dm_put_live_table(hc->md, srcu_idx);
if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr, false))
param->flags |= DM_UEVENT_GENERATED_FLAG;
md = hc->md;
dm_ima_measure_on_device_rename(md);
up_write(&_hash_lock);
kfree(old_name);
return md;
}
void dm_deferred_remove(void)
{
dm_hash_remove_all(true, false, true);
}
/*
*---------------------------------------------------------------
* Implementation of the ioctl commands
*---------------------------------------------------------------
*/
/*
* All the ioctl commands get dispatched to functions with this
* prototype.
*/
typedef int (*ioctl_fn)(struct file *filp, struct dm_ioctl *param, size_t param_size);
static int remove_all(struct file *filp, struct dm_ioctl *param, size_t param_size)
{
dm_hash_remove_all(true, !!(param->flags & DM_DEFERRED_REMOVE), false);
param->data_size = 0;
return 0;
}
/*
* Round up the ptr to an 8-byte boundary.
*/
#define ALIGN_MASK 7
static inline size_t align_val(size_t val)
{
return (val + ALIGN_MASK) & ~ALIGN_MASK;
}
static inline void *align_ptr(void *ptr)
{
return (void *)align_val((size_t)ptr);
}
/*
* Retrieves the data payload buffer from an already allocated
* struct dm_ioctl.
*/
static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
size_t *len)
{
param->data_start = align_ptr(param + 1) - (void *) param;
if (param->data_start < param_size)
*len = param_size - param->data_start;
else
*len = 0;
return ((void *) param) + param->data_start;
}
static bool filter_device(struct hash_cell *hc, const char *pfx_name, const char *pfx_uuid)
{
const char *val;
size_t val_len, pfx_len;
val = hc->name;
val_len = strlen(val);
pfx_len = strnlen(pfx_name, DM_NAME_LEN);
if (pfx_len > val_len)
return false;
if (memcmp(val, pfx_name, pfx_len))
return false;
val = hc->uuid ? hc->uuid : "";
val_len = strlen(val);
pfx_len = strnlen(pfx_uuid, DM_UUID_LEN);
if (pfx_len > val_len)
return false;
if (memcmp(val, pfx_uuid, pfx_len))
return false;
return true;
}
static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_size)
{
struct rb_node *n;
struct hash_cell *hc;
size_t len, needed = 0;
struct gendisk *disk;
struct dm_name_list *orig_nl, *nl, *old_nl = NULL;
uint32_t *event_nr;
down_write(&_hash_lock);
/*
* Loop through all the devices working out how much
* space we need.
*/
for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {
hc = container_of(n, struct hash_cell, name_node);
if (!filter_device(hc, param->name, param->uuid))
continue;
needed += align_val(offsetof(struct dm_name_list, name) + strlen(hc->name) + 1);
needed += align_val(sizeof(uint32_t) * 2);
if (param->flags & DM_UUID_FLAG && hc->uuid)
needed += align_val(strlen(hc->uuid) + 1);
}
/*
* Grab our output buffer.
*/
nl = orig_nl = get_result_buffer(param, param_size, &len);
if (len < needed || len < sizeof(nl->dev)) {
param->flags |= DM_BUFFER_FULL_FLAG;
goto out;
}
param->data_size = param->data_start + needed;
nl->dev = 0; /* Flags no data */
/*
* Now loop through filling out the names.
*/
for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {
void *uuid_ptr;
hc = container_of(n, struct hash_cell, name_node);
if (!filter_device(hc, param->name, param->uuid))
continue;
if (old_nl)
old_nl->next = (uint32_t) ((void *) nl -
(void *) old_nl);
disk = dm_disk(hc->md);
nl->dev = huge_encode_dev(disk_devt(disk));
nl->next = 0;
strcpy(nl->name, hc->name);
old_nl = nl;
event_nr = align_ptr(nl->name + strlen(hc->name) + 1);
event_nr[0] = dm_get_event_nr(hc->md);
event_nr[1] = 0;
uuid_ptr = align_ptr(event_nr + 2);
if (param->flags & DM_UUID_FLAG) {
if (hc->uuid) {
event_nr[1] |= DM_NAME_LIST_FLAG_HAS_UUID;
strcpy(uuid_ptr, hc->uuid);
uuid_ptr = align_ptr(uuid_ptr + strlen(hc->uuid) + 1);
} else {
event_nr[1] |= DM_NAME_LIST_FLAG_DOESNT_HAVE_UUID;
}
}
nl = uuid_ptr;
}
/*
* If mismatch happens, security may be compromised due to buffer
* overflow, so it's better to crash.
*/
BUG_ON((char *)nl - (char *)orig_nl != needed);
out:
up_write(&_hash_lock);
return 0;
}
static void list_version_get_needed(struct target_type *tt, void *needed_param)
{
size_t *needed = needed_param;
*needed += sizeof(struct dm_target_versions);
*needed += strlen(tt->name) + 1;
*needed += ALIGN_MASK;
}
static void list_version_get_info(struct target_type *tt, void *param)
{
struct vers_iter *info = param;
/* Check space - it might have changed since the first iteration */
if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 > info->end) {
info->flags = DM_BUFFER_FULL_FLAG;
return;
}
if (info->old_vers)
info->old_vers->next = (uint32_t) ((void *)info->vers - (void *)info->old_vers);
info->vers->version[0] = tt->version[0];
info->vers->version[1] = tt->version[1];
info->vers->version[2] = tt->version[2];
info->vers->next = 0;
strcpy(info->vers->name, tt->name);
info->old_vers = info->vers;
info->vers = align_ptr((void *)(info->vers + 1) + strlen(tt->name) + 1);
}
static int __list_versions(struct dm_ioctl *param, size_t param_size, const char *name)
{
size_t len, needed = 0;
struct dm_target_versions *vers;
struct vers_iter iter_info;
struct target_type *tt = NULL;
if (name) {
tt = dm_get_target_type(name);
if (!tt)
return -EINVAL;
}
/*
* Loop through all the devices working out how much
* space we need.
*/
if (!tt)
dm_target_iterate(list_version_get_needed, &needed);
else
list_version_get_needed(tt, &needed);
/*
* Grab our output buffer.
*/
vers = get_result_buffer(param, param_size, &len);
if (len < needed) {
param->flags |= DM_BUFFER_FULL_FLAG;
goto out;
}
param->data_size = param->data_start + needed;
iter_info.param_size = param_size;
iter_info.old_vers = NULL;
iter_info.vers = vers;
iter_info.flags = 0;
iter_info.end = (char *)vers + needed;
/*
* Now loop through filling out the names & versions.
*/
if (!tt)
dm_target_iterate(list_version_get_info, &iter_info);
else
list_version_get_info(tt, &iter_info);
param->flags |= iter_info.flags;
out:
if (tt)
dm_put_target_type(tt);
return 0;
}
static int list_versions(struct file *filp, struct dm_ioctl *param, size_t param_size)
{
return __list_versions(param, param_size, NULL);
}
static int get_target_version(struct file *filp, struct dm_ioctl *param, size_t param_size)
{
return __list_versions(param, param_size, param->name);
}
static int check_name(const char *name)
{
if (strchr(name, '/')) {
DMERR("device name cannot contain '/'");
return -EINVAL;
}
if (strcmp(name, DM_CONTROL_NODE) == 0 ||
strcmp(name, ".") == 0 ||
strcmp(name, "..") == 0) {
DMERR("device name cannot be \"%s\", \".\", or \"..\"", DM_CONTROL_NODE);
return -EINVAL;
}
return 0;
}
/*
* On successful return, the caller must not attempt to acquire
* _hash_lock without first calling dm_put_live_table, because dm_table_destroy
* waits for this dm_put_live_table and could be called under this lock.
*/
static struct dm_table *dm_get_inactive_table(struct mapped_device *md, int *srcu_idx)
{
struct hash_cell *hc;
struct dm_table *table = NULL;
/* increment rcu count, we don't care about the table pointer */
dm_get_live_table(md, srcu_idx);
down_read(&_hash_lock);
hc = dm_get_mdptr(md);
if (!hc) {
DMERR("device has been removed from the dev hash table.");
goto out;
}
table = hc->new_map;
out:
up_read(&_hash_lock);
return table;
}
static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
struct dm_ioctl *param,
int *srcu_idx)
{
return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
dm_get_inactive_table(md, srcu_idx) : dm_get_live_table(md, srcu_idx);
}
/*
* Fills in a dm_ioctl structure, ready for sending back to
* userland.
*/
static void __dev_status(struct mapped_device *md, struct dm_ioctl *param)
{
struct gendisk *disk = dm_disk(md);
struct dm_table *table;
int srcu_idx;
param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
DM_ACTIVE_PRESENT_FLAG | DM_INTERNAL_SUSPEND_FLAG);
if (dm_suspended_md(md))
param->flags |= DM_SUSPEND_FLAG;
if (dm_suspended_internally_md(md))
param->flags |= DM_INTERNAL_SUSPEND_FLAG;
if (dm_test_deferred_remove_flag(md))
param->flags |= DM_DEFERRED_REMOVE;
param->dev = huge_encode_dev(disk_devt(disk));
/*
* Yes, this will be out of date by the time it gets back
* to userland, but it is still very useful for
* debugging.
*/
param->open_count = dm_open_count(md);
param->event_nr = dm_get_event_nr(md);
param->target_count = 0;
table = dm_get_live_table(md, &srcu_idx);
if (table) {
if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
if (get_disk_ro(disk))
param->flags |= DM_READONLY_FLAG;
param->target_count = table->num_targets;
}
param->flags |= DM_ACTIVE_PRESENT_FLAG;
}
dm_put_live_table(md, srcu_idx);
if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
int srcu_idx;
table = dm_get_inactive_table(md, &srcu_idx);
if (table) {
if (!(dm_table_get_mode(table) & BLK_OPEN_WRITE))
param->flags |= DM_READONLY_FLAG;
param->target_count = table->num_targets;
}
dm_put_live_table(md, srcu_idx);
}
}
static int dev_create(struct file *filp, struct dm_ioctl *param, size_t param_size)
{
int r, m = DM_ANY_MINOR;
struct mapped_device *md;
r = check_name(param->name);
if (r)
return r;
if (param->flags & DM_PERSISTENT_DEV_FLAG)
m = MINOR(huge_decode_dev(param->dev));
r = dm_create(m, &md);
if (r)
return r;
r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
if (r) {
dm_put(md);
dm_destroy(md);
return r;
}
param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
__dev_status(md, param);
dm_put(md);
return 0;
}
/*
* Always use UUID for lookups if it's present, otherwise use name or dev.
*/
static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
{
struct hash_cell *hc = NULL;
if (*param->uuid) {
if (*param->name || param->dev) {
DMERR("Invalid ioctl structure: uuid %s, name %s, dev %llx",
param->uuid, param->name, (unsigned long long)param->dev);
return NULL;
}
hc = __get_uuid_cell(param->uuid);
if (!hc)
return NULL;
} else if (*param->name) {
if (param->dev) {
DMERR("Invalid ioctl structure: name %s, dev %llx",
param->name, (unsigned long long)param->dev);
return NULL;
}
hc = __get_name_cell(param->name);
if (!hc)
return NULL;
} else if (param->dev) {
hc = __get_dev_cell(param->dev);
if (!hc)
return NULL;
} else
return NULL;
/*
* Sneakily write in both the name and the uuid
* while we have the cell.
*/
strscpy(param->name, hc->name, sizeof(param->name));
if (hc->uuid)
strscpy(param->uuid, hc->uuid, sizeof(param->uuid));
else
param->uuid[0] = '\0';
if (hc->new_map)
param->flags |= DM_INACTIVE_PRESENT_FLAG;
else
param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
return hc;
}
static struct mapped_device *find_device(struct dm_ioctl *param)
{
struct hash_cell *hc;
struct mapped_device *md = NULL;
down_read(&_hash_lock);
hc = __find_device_hash_cell(param);
if (hc)
md = hc->md;
up_read(&_hash_lock);
return md;
}
static int dev_remove(struct file *filp, struct dm_ioctl *param, size_t param_size)
{
struct hash_cell *hc;
struct mapped_device *md;
int r;
struct dm_table *t;
down_write(&_hash_lock);
hc = __find_device_hash_cell(param);
if (!hc) {
DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
up_write(&_hash_lock);
return -ENXIO;
}
md = hc->md;
/*
* Ensure the device is not open and nothing further can open it.
*/
r = dm_lock_for_deletion(md, !!(param->flags & DM_DEFERRED_REMOVE), false);
if (r) {
if (r == -EBUSY && param->flags & DM_DEFERRED_REMOVE) {
up_write(&_hash_lock);
dm_put(md);
return 0;
}
DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
up_write(&_hash_lock);
dm_put(md);
return r;
}
t = __hash_remove(hc);
up_write(&_hash_lock);
if (t) {
dm_sync_table(md);
dm_table_destroy(t);
}
param->flags &= ~DM_DEFERRED_REMOVE;
dm_ima_measure_on_device_remove(md, false);
if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr, false))
param->flags |= DM_UEVENT_GENERATED_FLAG;
dm_put(md);
dm_destroy(md);
return 0;
}
/*
* Check a string doesn't overrun the chunk of
* memory we copied from userland.
*/
static int invalid_str(char *str, void *end)
{
while ((void *) str < end)
if (!*str++)
return 0;
return -EINVAL;
}
static int dev_rename(struct file *filp, struct dm_ioctl *param, size_t param_size)
{
int r;
char *new_data = (char *) param + param->data_start;
struct mapped_device *md;
unsigned int change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
if (new_data < param->data ||
invalid_str(new_data, (void *) param + param_size) || !*new_data ||
strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
DMERR("Invalid new mapped device name or uuid string supplied.");
return -EINVAL;
}
if (!change_uuid) {
r = check_name(new_data);
if (r)
return r;
}
md = dm_hash_rename(param, new_data);
if (IS_ERR(md))
return PTR_ERR(md);
__dev_status(md, param);
dm_put(md);
return 0;
}
static int dev_set_geometry(struct file *filp, struct dm_ioctl *param, size_t param_size)
{
int r = -EINVAL, x;
struct mapped_device *md;
struct hd_geometry geometry;
unsigned long indata[4];
char *geostr = (char *) param + param->data_start;
char dummy;
md = find_device(param);
if (!md)
return -ENXIO;
if (geostr < param->data ||
invalid_str(geostr, (void *) param + param_size)) {
DMERR("Invalid geometry supplied.");
goto out;
}
x = sscanf(geostr, "%lu %lu %lu %lu%c", indata,
indata + 1, indata + 2, indata + 3, &dummy);
if (x != 4) {
DMERR("Unable to interpret geometry settings.");
goto out;
}
if (indata[0] > 65535 || indata[1] > 255 || indata[2] > 255) {
DMERR("Geometry exceeds range limits.");
goto out;
}
geometry.cylinders = indata[0];
geometry.heads = indata[1];
geometry.sectors = indata[2];
geometry.start = indata[3];
r = dm_set_geometry(md, &geometry);
param->data_size = 0;
out:
dm_put(md);
return r;
}
static int do_suspend(struct dm_ioctl *param)
{
int r = 0;
unsigned int suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
struct mapped_device *md;
md = find_device(param);
if (!md)
return -ENXIO;
if (param->flags & DM_SKIP_LOCKFS_FLAG)
suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
if (param->flags & DM_NOFLUSH_FLAG)
suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
if (!dm_suspended_md(md)) {
r = dm_suspend(md, suspend_flags);
if (r)
goto out;
}
__dev_status(md, param);
out:
dm_put(md);
return r;
}
static int do_resume(struct dm_ioctl *param)
{
int r = 0;
unsigned int suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
struct hash_cell *hc;
struct mapped_device *md;
struct dm_table *new_map, *old_map = NULL;
bool need_resize_uevent = false;
down_write(&_hash_lock);
hc = __find_device_hash_cell(param);
if (!hc) {
DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
up_write(&_hash_lock);
return -ENXIO;
}
md = hc->md;
new_map = hc->new_map;
hc->new_map = NULL;
param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
up_write(&_hash_lock);
/* Do we need to load a new map ? */
if (new_map) {
sector_t old_size, new_size;
/* Suspend if it isn't already suspended */
if (param->flags & DM_SKIP_LOCKFS_FLAG)
suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
if (param->flags & DM_NOFLUSH_FLAG)
suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
if (!dm_suspended_md(md))
dm_suspend(md, suspend_flags);
old_size = dm_get_size(md);
old_map = dm_swap_table(md, new_map);
if (IS_ERR(old_map)) {
dm_sync_table(md);
dm_table_destroy(new_map);
dm_put(md);
return PTR_ERR(old_map);
}
new_size = dm_get_size(md);
if (old_size && new_size && old_size != new_size)
need_resize_uevent = true;
if (dm_table_get_mode(new_map) & BLK_OPEN_WRITE)
set_disk_ro(dm_disk(md), 0);
else
set_disk_ro(dm_disk(md), 1);
}
if (dm_suspended_md(md)) {
r = dm_resume(md);
if (!r) {
dm_ima_measure_on_device_resume(md, new_map ? true : false);
if (!dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr, need_resize_uevent))
param->flags |= DM_UEVENT_GENERATED_FLAG;
}
}
/*
* Since dm_swap_table synchronizes RCU, nobody should be in
* read-side critical section already.
*/
if (old_map)
dm_table_destroy(old_map);
if (!r)
__dev_status(md, param);
dm_put(md);
return r;
}
/*
* Set or unset the suspension state of a device.
* If the device already is in the requested state we just return its status.
*/
static int dev_suspend(struct file *filp, struct dm_ioctl *param, size_t param_size)
{
if (param->flags & DM_SUSPEND_FLAG)
return do_suspend(param);
return do_resume(param);
}
/*
* Copies device info back to user space, used by
* the create and info ioctls.
*/
static int dev_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
{
struct mapped_device *md;
md = find_device(param);
if (!md)
return -ENXIO;
__dev_status(md, param);
dm_put(md);
return 0;
}
/*
* Build up the status struct for each target
*/
static void retrieve_status(struct dm_table *table,
struct dm_ioctl *param, size_t param_size)
{
unsigned int i, num_targets;
struct dm_target_spec *spec;
char *outbuf, *outptr;
status_type_t type;
size_t remaining, len, used = 0;
unsigned int status_flags = 0;
outptr = outbuf = get_result_buffer(param, param_size, &len);
if (param->flags & DM_STATUS_TABLE_FLAG)
type = STATUSTYPE_TABLE;
else if (param->flags & DM_IMA_MEASUREMENT_FLAG)
type = STATUSTYPE_IMA;
else
type = STATUSTYPE_INFO;
/* Get all the target info */
num_targets = table->num_targets;
for (i = 0; i < num_targets; i++) {
struct dm_target *ti = dm_table_get_target(table, i);
size_t l;
remaining = len - (outptr - outbuf);
if (remaining <= sizeof(struct dm_target_spec)) {
param->flags |= DM_BUFFER_FULL_FLAG;
break;
}
spec = (struct dm_target_spec *) outptr;
spec->status = 0;
spec->sector_start = ti->begin;
spec->length = ti->len;
strncpy(spec->target_type, ti->type->name,
sizeof(spec->target_type) - 1);
outptr += sizeof(struct dm_target_spec);
remaining = len - (outptr - outbuf);
if (remaining <= 0) {
param->flags |= DM_BUFFER_FULL_FLAG;
break;
}
/* Get the status/table string from the target driver */
if (ti->type->status) {
if (param->flags & DM_NOFLUSH_FLAG)
status_flags |= DM_STATUS_NOFLUSH_FLAG;
ti->type->status(ti, type, status_flags, outptr, remaining);
} else
outptr[0] = '\0';
l = strlen(outptr) + 1;
if (l == remaining) {
param->flags |= DM_BUFFER_FULL_FLAG;
break;
}
outptr += l;
used = param->data_start + (outptr - outbuf);
outptr = align_ptr(outptr);
spec->next = outptr - outbuf;
}
if (used)
param->data_size = used;
param->target_count = num_targets;
}
/*
* Wait for a device to report an event
*/
static int dev_wait(struct file *filp, struct dm_ioctl *param, size_t param_size)
{
int r = 0;
struct mapped_device *md;
struct dm_table *table;
int srcu_idx;
md = find_device(param);
if (!md)
return -ENXIO;
/*
* Wait for a notification event
*/
if (dm_wait_event(md, param->event_nr)) {
r = -ERESTARTSYS;
goto out;
}
/*
* The userland program is going to want to know what
* changed to trigger the event, so we may as well tell
* him and save an ioctl.
*/
__dev_status(md, param);
table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
if (table)
retrieve_status(table, param, param_size);
dm_put_live_table(md, srcu_idx);
out:
dm_put(md);
return r;
}
/*
* Remember the global event number and make it possible to poll
* for further events.
*/
static int dev_arm_poll(struct file *filp, struct dm_ioctl *param, size_t param_size)
{
struct dm_file *priv = filp->private_data;
priv->global_event_nr = atomic_read(&dm_global_event_nr);
return 0;
}
static inline blk_mode_t get_mode(struct dm_ioctl *param)
{
blk_mode_t mode = BLK_OPEN_READ | BLK_OPEN_WRITE;
if (param->flags & DM_READONLY_FLAG)
mode = BLK_OPEN_READ;
return mode;
}
static int next_target(struct dm_target_spec *last, uint32_t next, const char *end,
struct dm_target_spec **spec, char **target_params)
{
static_assert(__alignof__(struct dm_target_spec) <= 8,
"struct dm_target_spec must not require more than 8-byte alignment");
/*
* Number of bytes remaining, starting with last. This is always
* sizeof(struct dm_target_spec) or more, as otherwise *last was
* out of bounds already.
*/
size_t remaining = end - (char *)last;
/*
* There must be room for both the next target spec and the
* NUL-terminator of the target itself.
*/
if (remaining - sizeof(struct dm_target_spec) <= next) {
DMERR("Target spec extends beyond end of parameters");
return -EINVAL;
}
if (next % __alignof__(struct dm_target_spec)) {
DMERR("Next dm_target_spec (offset %u) is not %zu-byte aligned",
next, __alignof__(struct dm_target_spec));
return -EINVAL;
}
*spec = (struct dm_target_spec *) ((unsigned char *) last + next);
*target_params = (char *) (*spec + 1);
return 0;
}
static int populate_table(struct dm_table *table,
struct dm_ioctl *param, size_t param_size)
{
int r;
unsigned int i = 0;
struct dm_target_spec *spec = (struct dm_target_spec *) param;
uint32_t next = param->data_start;
const char *const end = (const char *) param + param_size;
char *target_params;
size_t min_size = sizeof(struct dm_ioctl);
if (!param->target_count) {
DMERR("%s: no targets specified", __func__);
return -EINVAL;
}
for (i = 0; i < param->target_count; i++) {
const char *nul_terminator;
if (next < min_size) {
DMERR("%s: next target spec (offset %u) overlaps %s",
__func__, next, i ? "previous target" : "'struct dm_ioctl'");
return -EINVAL;
}
r = next_target(spec, next, end, &spec, &target_params);
if (r) {
DMERR("unable to find target");
return r;
}
nul_terminator = memchr(target_params, 0, (size_t)(end - target_params));
if (nul_terminator == NULL) {
DMERR("%s: target parameters not NUL-terminated", __func__);
return -EINVAL;
}
/* Add 1 for NUL terminator */
min_size = (size_t)(nul_terminator - (const char *)spec) + 1;
r = dm_table_add_target(table, spec->target_type,
(sector_t) spec->sector_start,
(sector_t) spec->length,
target_params);
if (r) {
DMERR("error adding target to table");
return r;
}
next = spec->next;
}
return dm_table_complete(table);
}
static bool is_valid_type(enum dm_queue_mode cur, enum dm_queue_mode new)
{
if (cur == new ||
(cur == DM_TYPE_BIO_BASED && new == DM_TYPE_DAX_BIO_BASED))
return true;
return false;
}
static int table_load(struct file *filp, struct dm_ioctl *param, size_t param_size)
{
int r;
struct hash_cell *hc;
struct dm_table *t, *old_map = NULL;
struct mapped_device *md;
struct target_type *immutable_target_type;
md = find_device(param);
if (!md)
return -ENXIO;
r = dm_table_create(&t, get_mode(param), param->target_count, md);
if (r)
goto err;
/* Protect md->type and md->queue against concurrent table loads. */
dm_lock_md_type(md);
r = populate_table(t, param, param_size);
if (r)
goto err_unlock_md_type;
dm_ima_measure_on_table_load(t, STATUSTYPE_IMA);
immutable_target_type = dm_get_immutable_target_type(md);
if (immutable_target_type &&
(immutable_target_type != dm_table_get_immutable_target_type(t)) &&
!dm_table_get_wildcard_target(t)) {
DMERR("can't replace immutable target type %s",
immutable_target_type->name);
r = -EINVAL;
goto err_unlock_md_type;
}
if (dm_get_md_type(md) == DM_TYPE_NONE) {
/* setup md->queue to reflect md's type (may block) */
r = dm_setup_md_queue(md, t);
if (r) {
DMERR("unable to set up device queue for new table.");
goto err_unlock_md_type;
}
} else if (!is_valid_type(dm_get_md_type(md), dm_table_get_type(t))) {
DMERR("can't change device type (old=%u vs new=%u) after initial table load.",
dm_get_md_type(md), dm_table_get_type(t));
r = -EINVAL;
goto err_unlock_md_type;
}
dm_unlock_md_type(md);
/* stage inactive table */
down_write(&_hash_lock);
hc = dm_get_mdptr(md);
if (!hc) {
DMERR("device has been removed from the dev hash table.");
up_write(&_hash_lock);
r = -ENXIO;
goto err_destroy_table;
}
if (hc->new_map)
old_map = hc->new_map;
hc->new_map = t;
up_write(&_hash_lock);
param->flags |= DM_INACTIVE_PRESENT_FLAG;
__dev_status(md, param);
if (old_map) {
dm_sync_table(md);
dm_table_destroy(old_map);
}
dm_put(md);
return 0;
err_unlock_md_type:
dm_unlock_md_type(md);
err_destroy_table:
dm_table_destroy(t);
err:
dm_put(md);
return r;
}
static int table_clear(struct file *filp, struct dm_ioctl *param, size_t param_size)
{
struct hash_cell *hc;
struct mapped_device *md;
struct dm_table *old_map = NULL;
bool has_new_map = false;
down_write(&_hash_lock);
hc = __find_device_hash_cell(param);
if (!hc) {
DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
up_write(&_hash_lock);
return -ENXIO;
}
if (hc->new_map) {
old_map = hc->new_map;
hc->new_map = NULL;
has_new_map = true;
}
md = hc->md;
up_write(&_hash_lock);
param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
__dev_status(md, param);
if (old_map) {
dm_sync_table(md);
dm_table_destroy(old_map);
}
dm_ima_measure_on_table_clear(md, has_new_map);
dm_put(md);
return 0;
}
/*
* Retrieves a list of devices used by a particular dm device.
*/
static void retrieve_deps(struct dm_table *table,
struct dm_ioctl *param, size_t param_size)
{
unsigned int count = 0;
struct list_head *tmp;
size_t len, needed;
struct dm_dev_internal *dd;
struct dm_target_deps *deps;
down_read(&table->devices_lock);
deps = get_result_buffer(param, param_size, &len);
/*
* Count the devices.
*/
list_for_each(tmp, dm_table_get_devices(table))
count++;
/*
* Check we have enough space.
*/
needed = struct_size(deps, dev, count);
if (len < needed) {
param->flags |= DM_BUFFER_FULL_FLAG;
goto out;
}
/*
* Fill in the devices.
*/
deps->count = count;
count = 0;
list_for_each_entry(dd, dm_table_get_devices(table), list)
deps->dev[count++] = huge_encode_dev(dd->dm_dev->bdev->bd_dev);
param->data_size = param->data_start + needed;
out:
up_read(&table->devices_lock);
}
static int table_deps(struct file *filp, struct dm_ioctl *param, size_t param_size)
{
struct mapped_device *md;
struct dm_table *table;
int srcu_idx;
md = find_device(param);
if (!md)
return -ENXIO;
__dev_status(md, param);
table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
if (table)
retrieve_deps(table, param, param_size);
dm_put_live_table(md, srcu_idx);
dm_put(md);
return 0;
}
/*
* Return the status of a device as a text string for each
* target.
*/
static int table_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
{
struct mapped_device *md;
struct dm_table *table;
int srcu_idx;
md = find_device(param);
if (!md)
return -ENXIO;
__dev_status(md, param);
table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
if (table)
retrieve_status(table, param, param_size);
dm_put_live_table(md, srcu_idx);
dm_put(md);
return 0;
}
/*
* Process device-mapper dependent messages. Messages prefixed with '@'
* are processed by the DM core. All others are delivered to the target.
* Returns a number <= 1 if message was processed by device mapper.
* Returns 2 if message should be delivered to the target.
*/
static int message_for_md(struct mapped_device *md, unsigned int argc, char **argv,
char *result, unsigned int maxlen)
{
int r;
if (**argv != '@')
return 2; /* no '@' prefix, deliver to target */
if (!strcasecmp(argv[0], "@cancel_deferred_remove")) {
if (argc != 1) {
DMERR("Invalid arguments for @cancel_deferred_remove");
return -EINVAL;
}
return dm_cancel_deferred_remove(md);
}
r = dm_stats_message(md, argc, argv, result, maxlen);
if (r < 2)
return r;
DMERR("Unsupported message sent to DM core: %s", argv[0]);
return -EINVAL;
}
/*
* Pass a message to the target that's at the supplied device offset.
*/
static int target_message(struct file *filp, struct dm_ioctl *param, size_t param_size)
{
int r, argc;
char **argv;
struct mapped_device *md;
struct dm_table *table;
struct dm_target *ti;
struct dm_target_msg *tmsg = (void *) param + param->data_start;
size_t maxlen;
char *result = get_result_buffer(param, param_size, &maxlen);
int srcu_idx;
md = find_device(param);
if (!md)
return -ENXIO;
if (tmsg < (struct dm_target_msg *) param->data ||
invalid_str(tmsg->message, (void *) param + param_size)) {
DMERR("Invalid target message parameters.");
r = -EINVAL;
goto out;
}
r = dm_split_args(&argc, &argv, tmsg->message);
if (r) {
DMERR("Failed to split target message parameters");
goto out;
}
if (!argc) {
DMERR("Empty message received.");
r = -EINVAL;
goto out_argv;
}
r = message_for_md(md, argc, argv, result, maxlen);
if (r <= 1)
goto out_argv;
table = dm_get_live_table(md, &srcu_idx);
if (!table)
goto out_table;
if (dm_deleting_md(md)) {
r = -ENXIO;
goto out_table;
}
ti = dm_table_find_target(table, tmsg->sector);
if (!ti) {
DMERR("Target message sector outside device.");
r = -EINVAL;
} else if (ti->type->message)
r = ti->type->message(ti, argc, argv, result, maxlen);
else {
DMERR("Target type does not support messages");
r = -EINVAL;
}
out_table:
dm_put_live_table(md, srcu_idx);
out_argv:
kfree(argv);
out:
if (r >= 0)
__dev_status(md, param);
if (r == 1) {
param->flags |= DM_DATA_OUT_FLAG;
if (dm_message_test_buffer_overflow(result, maxlen))
param->flags |= DM_BUFFER_FULL_FLAG;
else
param->data_size = param->data_start + strlen(result) + 1;
r = 0;
}
dm_put(md);
return r;
}
/*
* The ioctl parameter block consists of two parts, a dm_ioctl struct
* followed by a data buffer. This flag is set if the second part,
* which has a variable size, is not used by the function processing
* the ioctl.
*/
#define IOCTL_FLAGS_NO_PARAMS 1
#define IOCTL_FLAGS_ISSUE_GLOBAL_EVENT 2
/*
*---------------------------------------------------------------
* Implementation of open/close/ioctl on the special char device.
*---------------------------------------------------------------
*/
static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags)
{
static const struct {
int cmd;
int flags;
ioctl_fn fn;
} _ioctls[] = {
{DM_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */
{DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, remove_all},
{DM_LIST_DEVICES_CMD, 0, list_devices},
{DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_create},
{DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_remove},
{DM_DEV_RENAME_CMD, IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_rename},
{DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, dev_suspend},
{DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, dev_status},
{DM_DEV_WAIT_CMD, 0, dev_wait},
{DM_TABLE_LOAD_CMD, 0, table_load},
{DM_TABLE_CLEAR_CMD, IOCTL_FLAGS_NO_PARAMS, table_clear},
{DM_TABLE_DEPS_CMD, 0, table_deps},
{DM_TABLE_STATUS_CMD, 0, table_status},
{DM_LIST_VERSIONS_CMD, 0, list_versions},
{DM_TARGET_MSG_CMD, 0, target_message},
{DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry},
{DM_DEV_ARM_POLL_CMD, IOCTL_FLAGS_NO_PARAMS, dev_arm_poll},
{DM_GET_TARGET_VERSION_CMD, 0, get_target_version},
};
if (unlikely(cmd >= ARRAY_SIZE(_ioctls)))
return NULL;
cmd = array_index_nospec(cmd, ARRAY_SIZE(_ioctls));
*ioctl_flags = _ioctls[cmd].flags;
return _ioctls[cmd].fn;
}
/*
* As well as checking the version compatibility this always
* copies the kernel interface version out.
*/
static int check_version(unsigned int cmd, struct dm_ioctl __user *user,
struct dm_ioctl *kernel_params)
{
int r = 0;
/* Make certain version is first member of dm_ioctl struct */
BUILD_BUG_ON(offsetof(struct dm_ioctl, version) != 0);
if (copy_from_user(kernel_params->version, user->version, sizeof(kernel_params->version)))
return -EFAULT;
if ((kernel_params->version[0] != DM_VERSION_MAJOR) ||
(kernel_params->version[1] > DM_VERSION_MINOR)) {
DMERR("ioctl interface mismatch: kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
DM_VERSION_MAJOR, DM_VERSION_MINOR,
DM_VERSION_PATCHLEVEL,
kernel_params->version[0],
kernel_params->version[1],
kernel_params->version[2],
cmd);
r = -EINVAL;
}
/*
* Fill in the kernel version.
*/
kernel_params->version[0] = DM_VERSION_MAJOR;
kernel_params->version[1] = DM_VERSION_MINOR;
kernel_params->version[2] = DM_VERSION_PATCHLEVEL;
if (copy_to_user(user->version, kernel_params->version, sizeof(kernel_params->version)))
return -EFAULT;
return r;
}
#define DM_PARAMS_MALLOC 0x0001 /* Params allocated with kvmalloc() */
#define DM_WIPE_BUFFER 0x0010 /* Wipe input buffer before returning from ioctl */
static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags)
{
if (param_flags & DM_WIPE_BUFFER)
memset(param, 0, param_size);
if (param_flags & DM_PARAMS_MALLOC)
kvfree(param);
}
static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel,
int ioctl_flags, struct dm_ioctl **param, int *param_flags)
{
struct dm_ioctl *dmi;
int secure_data;
const size_t minimum_data_size = offsetof(struct dm_ioctl, data);
/* check_version() already copied version from userspace, avoid TOCTOU */
if (copy_from_user((char *)param_kernel + sizeof(param_kernel->version),
(char __user *)user + sizeof(param_kernel->version),
minimum_data_size - sizeof(param_kernel->version)))
return -EFAULT;
if (param_kernel->data_size < minimum_data_size) {
DMERR("Invalid data size in the ioctl structure: %u",
param_kernel->data_size);
return -EINVAL;
}
secure_data = param_kernel->flags & DM_SECURE_DATA_FLAG;
*param_flags = secure_data ? DM_WIPE_BUFFER : 0;
if (ioctl_flags & IOCTL_FLAGS_NO_PARAMS) {
dmi = param_kernel;
dmi->data_size = minimum_data_size;
goto data_copied;
}
/*
* Use __GFP_HIGH to avoid low memory issues when a device is
* suspended and the ioctl is needed to resume it.
* Use kmalloc() rather than vmalloc() when we can.
*/
dmi = NULL;
dmi = kvmalloc(param_kernel->data_size, GFP_NOIO | __GFP_HIGH);
if (!dmi) {
if (secure_data && clear_user(user, param_kernel->data_size))
return -EFAULT;
return -ENOMEM;
}
*param_flags |= DM_PARAMS_MALLOC;
/* Copy from param_kernel (which was already copied from user) */
memcpy(dmi, param_kernel, minimum_data_size);
if (copy_from_user(&dmi->data, (char __user *)user + minimum_data_size,
param_kernel->data_size - minimum_data_size))
goto bad;
data_copied:
/* Wipe the user buffer so we do not return it to userspace */
if (secure_data && clear_user(user, param_kernel->data_size))
goto bad;
*param = dmi;
return 0;
bad:
free_params(dmi, param_kernel->data_size, *param_flags);
return -EFAULT;
}
static int validate_params(uint cmd, struct dm_ioctl *param)
{
/* Always clear this flag */
param->flags &= ~DM_BUFFER_FULL_FLAG;
param->flags &= ~DM_UEVENT_GENERATED_FLAG;
param->flags &= ~DM_SECURE_DATA_FLAG;
param->flags &= ~DM_DATA_OUT_FLAG;
/* Ignores parameters */
if (cmd == DM_REMOVE_ALL_CMD ||
cmd == DM_LIST_DEVICES_CMD ||
cmd == DM_LIST_VERSIONS_CMD)
return 0;
if (cmd == DM_DEV_CREATE_CMD) {
if (!*param->name) {
DMERR("name not supplied when creating device");
return -EINVAL;
}
} else if (*param->uuid && *param->name) {
DMERR("only supply one of name or uuid, cmd(%u)", cmd);
return -EINVAL;
}
/* Ensure strings are terminated */
param->name[DM_NAME_LEN - 1] = '\0';
param->uuid[DM_UUID_LEN - 1] = '\0';
return 0;
}
static int ctl_ioctl(struct file *file, uint command, struct dm_ioctl __user *user)
{
int r = 0;
int ioctl_flags;
int param_flags;
unsigned int cmd;
struct dm_ioctl *param;
ioctl_fn fn = NULL;
size_t input_param_size;
struct dm_ioctl param_kernel;
/* only root can play with this */
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (_IOC_TYPE(command) != DM_IOCTL)
return -ENOTTY;
cmd = _IOC_NR(command);
/*
* Check the interface version passed in. This also
* writes out the kernel's interface version.
*/
r = check_version(cmd, user, ¶m_kernel);
if (r)
return r;
/*
* Nothing more to do for the version command.
*/
if (cmd == DM_VERSION_CMD)
return 0;
fn = lookup_ioctl(cmd, &ioctl_flags);
if (!fn) {
DMERR("dm_ctl_ioctl: unknown command 0x%x", command);
return -ENOTTY;
}
/*
* Copy the parameters into kernel space.
*/
r = copy_params(user, ¶m_kernel, ioctl_flags, ¶m, ¶m_flags);
if (r)
return r;
input_param_size = param->data_size;
r = validate_params(cmd, param);
if (r)
goto out;
param->data_size = offsetof(struct dm_ioctl, data);
r = fn(file, param, input_param_size);
if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) &&
unlikely(ioctl_flags & IOCTL_FLAGS_NO_PARAMS))
DMERR("ioctl %d tried to output some data but has IOCTL_FLAGS_NO_PARAMS set", cmd);
if (!r && ioctl_flags & IOCTL_FLAGS_ISSUE_GLOBAL_EVENT)
dm_issue_global_event();
/*
* Copy the results back to userland.
*/
if (!r && copy_to_user(user, param, param->data_size))
r = -EFAULT;
out:
free_params(param, input_param_size, param_flags);
return r;
}
static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
{
return (long)ctl_ioctl(file, command, (struct dm_ioctl __user *)u);
}
#ifdef CONFIG_COMPAT
static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
{
return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
}
#else
#define dm_compat_ctl_ioctl NULL
#endif
static int dm_open(struct inode *inode, struct file *filp)
{
int r;
struct dm_file *priv;
r = nonseekable_open(inode, filp);
if (unlikely(r))
return r;
priv = filp->private_data = kmalloc(sizeof(struct dm_file), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->global_event_nr = atomic_read(&dm_global_event_nr);
return 0;
}
static int dm_release(struct inode *inode, struct file *filp)
{
kfree(filp->private_data);
return 0;
}
static __poll_t dm_poll(struct file *filp, poll_table *wait)
{
struct dm_file *priv = filp->private_data;
__poll_t mask = 0;
poll_wait(filp, &dm_global_eventq, wait);
if ((int)(atomic_read(&dm_global_event_nr) - priv->global_event_nr) > 0)
mask |= EPOLLIN;
return mask;
}
static const struct file_operations _ctl_fops = {
.open = dm_open,
.release = dm_release,
.poll = dm_poll,
.unlocked_ioctl = dm_ctl_ioctl,
.compat_ioctl = dm_compat_ctl_ioctl,
.owner = THIS_MODULE,
.llseek = noop_llseek,
};
static struct miscdevice _dm_misc = {
.minor = MAPPER_CTRL_MINOR,
.name = DM_NAME,
.nodename = DM_DIR "/" DM_CONTROL_NODE,
.fops = &_ctl_fops
};
MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
/*
* Create misc character device and link to DM_DIR/control.
*/
int __init dm_interface_init(void)
{
int r;
r = misc_register(&_dm_misc);
if (r) {
DMERR("misc_register failed for control device");
return r;
}
DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
DM_DRIVER_EMAIL);
return 0;
}
void dm_interface_exit(void)
{
misc_deregister(&_dm_misc);
dm_hash_exit();
}
/**
* dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
* @md: Pointer to mapped_device
* @name: Buffer (size DM_NAME_LEN) for name
* @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
*/
int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
{
int r = 0;
struct hash_cell *hc;
if (!md)
return -ENXIO;
mutex_lock(&dm_hash_cells_mutex);
hc = dm_get_mdptr(md);
if (!hc) {
r = -ENXIO;
goto out;
}
if (name)
strcpy(name, hc->name);
if (uuid)
strcpy(uuid, hc->uuid ? : "");
out:
mutex_unlock(&dm_hash_cells_mutex);
return r;
}
EXPORT_SYMBOL_GPL(dm_copy_name_and_uuid);
/**
* dm_early_create - create a mapped device in early boot.
*
* @dmi: Contains main information of the device mapping to be created.
* @spec_array: array of pointers to struct dm_target_spec. Describes the
* mapping table of the device.
* @target_params_array: array of strings with the parameters to a specific
* target.
*
* Instead of having the struct dm_target_spec and the parameters for every
* target embedded at the end of struct dm_ioctl (as performed in a normal
* ioctl), pass them as arguments, so the caller doesn't need to serialize them.
* The size of the spec_array and target_params_array is given by
* @dmi->target_count.
* This function is supposed to be called in early boot, so locking mechanisms
* to protect against concurrent loads are not required.
*/
int __init dm_early_create(struct dm_ioctl *dmi,
struct dm_target_spec **spec_array,
char **target_params_array)
{
int r, m = DM_ANY_MINOR;
struct dm_table *t, *old_map;
struct mapped_device *md;
unsigned int i;
if (!dmi->target_count)
return -EINVAL;
r = check_name(dmi->name);
if (r)
return r;
if (dmi->flags & DM_PERSISTENT_DEV_FLAG)
m = MINOR(huge_decode_dev(dmi->dev));
/* alloc dm device */
r = dm_create(m, &md);
if (r)
return r;
/* hash insert */
r = dm_hash_insert(dmi->name, *dmi->uuid ? dmi->uuid : NULL, md);
if (r)
goto err_destroy_dm;
/* alloc table */
r = dm_table_create(&t, get_mode(dmi), dmi->target_count, md);
if (r)
goto err_hash_remove;
/* add targets */
for (i = 0; i < dmi->target_count; i++) {
r = dm_table_add_target(t, spec_array[i]->target_type,
(sector_t) spec_array[i]->sector_start,
(sector_t) spec_array[i]->length,
target_params_array[i]);
if (r) {
DMERR("error adding target to table");
goto err_destroy_table;
}
}
/* finish table */
r = dm_table_complete(t);
if (r)
goto err_destroy_table;
/* setup md->queue to reflect md's type (may block) */
r = dm_setup_md_queue(md, t);
if (r) {
DMERR("unable to set up device queue for new table.");
goto err_destroy_table;
}
/* Set new map */
dm_suspend(md, 0);
old_map = dm_swap_table(md, t);
if (IS_ERR(old_map)) {
r = PTR_ERR(old_map);
goto err_destroy_table;
}
set_disk_ro(dm_disk(md), !!(dmi->flags & DM_READONLY_FLAG));
/* resume device */
r = dm_resume(md);
if (r)
goto err_destroy_table;
DMINFO("%s (%s) is ready", md->disk->disk_name, dmi->name);
dm_put(md);
return 0;
err_destroy_table:
dm_table_destroy(t);
err_hash_remove:
down_write(&_hash_lock);
(void) __hash_remove(__get_name_cell(dmi->name));
up_write(&_hash_lock);
/* release reference from __get_name_cell */
dm_put(md);
err_destroy_dm:
dm_put(md);
dm_destroy(md);
return r;
}
| linux-master | drivers/md/dm-ioctl.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2011-2012 Red Hat, Inc.
*
* This file is released under the GPL.
*/
#include "dm-thin-metadata.h"
#include "persistent-data/dm-btree.h"
#include "persistent-data/dm-space-map.h"
#include "persistent-data/dm-space-map-disk.h"
#include "persistent-data/dm-transaction-manager.h"
#include <linux/list.h>
#include <linux/device-mapper.h>
#include <linux/workqueue.h>
/*
*--------------------------------------------------------------------------
* As far as the metadata goes, there is:
*
* - A superblock in block zero, taking up fewer than 512 bytes for
* atomic writes.
*
* - A space map managing the metadata blocks.
*
* - A space map managing the data blocks.
*
* - A btree mapping our internal thin dev ids onto struct disk_device_details.
*
* - A hierarchical btree, with 2 levels which effectively maps (thin
* dev id, virtual block) -> block_time. Block time is a 64-bit
* field holding the time in the low 24 bits, and block in the top 40
* bits.
*
* BTrees consist solely of btree_nodes, that fill a block. Some are
* internal nodes, as such their values are a __le64 pointing to other
* nodes. Leaf nodes can store data of any reasonable size (ie. much
* smaller than the block size). The nodes consist of the header,
* followed by an array of keys, followed by an array of values. We have
* to binary search on the keys so they're all held together to help the
* cpu cache.
*
* Space maps have 2 btrees:
*
* - One maps a uint64_t onto a struct index_entry. Which points to a
* bitmap block, and has some details about how many free entries there
* are etc.
*
* - The bitmap blocks have a header (for the checksum). Then the rest
* of the block is pairs of bits. With the meaning being:
*
* 0 - ref count is 0
* 1 - ref count is 1
* 2 - ref count is 2
* 3 - ref count is higher than 2
*
* - If the count is higher than 2 then the ref count is entered in a
* second btree that directly maps the block_address to a uint32_t ref
* count.
*
* The space map metadata variant doesn't have a bitmaps btree. Instead
* it has one single blocks worth of index_entries. This avoids
* recursive issues with the bitmap btree needing to allocate space in
* order to insert. With a small data block size such as 64k the
* metadata support data devices that are hundreds of terrabytes.
*
* The space maps allocate space linearly from front to back. Space that
* is freed in a transaction is never recycled within that transaction.
* To try and avoid fragmenting _free_ space the allocator always goes
* back and fills in gaps.
*
* All metadata io is in THIN_METADATA_BLOCK_SIZE sized/aligned chunks
* from the block manager.
*--------------------------------------------------------------------------
*/
#define DM_MSG_PREFIX "thin metadata"
#define THIN_SUPERBLOCK_MAGIC 27022010
#define THIN_SUPERBLOCK_LOCATION 0
#define THIN_VERSION 2
#define SECTOR_TO_BLOCK_SHIFT 3
/*
* For btree insert:
* 3 for btree insert +
* 2 for btree lookup used within space map
* For btree remove:
* 2 for shadow spine +
* 4 for rebalance 3 child node
*/
#define THIN_MAX_CONCURRENT_LOCKS 6
/* This should be plenty */
#define SPACE_MAP_ROOT_SIZE 128
/*
* Little endian on-disk superblock and device details.
*/
struct thin_disk_superblock {
__le32 csum; /* Checksum of superblock except for this field. */
__le32 flags;
__le64 blocknr; /* This block number, dm_block_t. */
__u8 uuid[16];
__le64 magic;
__le32 version;
__le32 time;
__le64 trans_id;
/*
* Root held by userspace transactions.
*/
__le64 held_root;
__u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];
__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
/*
* 2-level btree mapping (dev_id, (dev block, time)) -> data block
*/
__le64 data_mapping_root;
/*
* Device detail root mapping dev_id -> device_details
*/
__le64 device_details_root;
__le32 data_block_size; /* In 512-byte sectors. */
__le32 metadata_block_size; /* In 512-byte sectors. */
__le64 metadata_nr_blocks;
__le32 compat_flags;
__le32 compat_ro_flags;
__le32 incompat_flags;
} __packed;
struct disk_device_details {
__le64 mapped_blocks;
__le64 transaction_id; /* When created. */
__le32 creation_time;
__le32 snapshotted_time;
} __packed;
struct dm_pool_metadata {
struct hlist_node hash;
struct block_device *bdev;
struct dm_block_manager *bm;
struct dm_space_map *metadata_sm;
struct dm_space_map *data_sm;
struct dm_transaction_manager *tm;
struct dm_transaction_manager *nb_tm;
/*
* Two-level btree.
* First level holds thin_dev_t.
* Second level holds mappings.
*/
struct dm_btree_info info;
/*
* Non-blocking version of the above.
*/
struct dm_btree_info nb_info;
/*
* Just the top level for deleting whole devices.
*/
struct dm_btree_info tl_info;
/*
* Just the bottom level for creating new devices.
*/
struct dm_btree_info bl_info;
/*
* Describes the device details btree.
*/
struct dm_btree_info details_info;
struct rw_semaphore root_lock;
uint32_t time;
dm_block_t root;
dm_block_t details_root;
struct list_head thin_devices;
uint64_t trans_id;
unsigned long flags;
sector_t data_block_size;
/*
* Pre-commit callback.
*
* This allows the thin provisioning target to run a callback before
* the metadata are committed.
*/
dm_pool_pre_commit_fn pre_commit_fn;
void *pre_commit_context;
/*
* We reserve a section of the metadata for commit overhead.
* All reported space does *not* include this.
*/
dm_block_t metadata_reserve;
/*
* Set if a transaction has to be aborted but the attempt to roll back
* to the previous (good) transaction failed. The only pool metadata
* operation possible in this state is the closing of the device.
*/
bool fail_io:1;
/*
* Set once a thin-pool has been accessed through one of the interfaces
* that imply the pool is in-service (e.g. thin devices created/deleted,
* thin-pool message, metadata snapshots, etc).
*/
bool in_service:1;
/*
* Reading the space map roots can fail, so we read it into these
* buffers before the superblock is locked and updated.
*/
__u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];
__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
};
struct dm_thin_device {
struct list_head list;
struct dm_pool_metadata *pmd;
dm_thin_id id;
int open_count;
bool changed:1;
bool aborted_with_changes:1;
uint64_t mapped_blocks;
uint64_t transaction_id;
uint32_t creation_time;
uint32_t snapshotted_time;
};
/*
*--------------------------------------------------------------
* superblock validator
*--------------------------------------------------------------
*/
#define SUPERBLOCK_CSUM_XOR 160774
static void sb_prepare_for_write(struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
struct thin_disk_superblock *disk_super = dm_block_data(b);
disk_super->blocknr = cpu_to_le64(dm_block_location(b));
disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
block_size - sizeof(__le32),
SUPERBLOCK_CSUM_XOR));
}
static int sb_check(struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
struct thin_disk_superblock *disk_super = dm_block_data(b);
__le32 csum_le;
if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {
DMERR("%s failed: blocknr %llu: wanted %llu",
__func__, le64_to_cpu(disk_super->blocknr),
(unsigned long long)dm_block_location(b));
return -ENOTBLK;
}
if (le64_to_cpu(disk_super->magic) != THIN_SUPERBLOCK_MAGIC) {
DMERR("%s failed: magic %llu: wanted %llu",
__func__, le64_to_cpu(disk_super->magic),
(unsigned long long)THIN_SUPERBLOCK_MAGIC);
return -EILSEQ;
}
csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
block_size - sizeof(__le32),
SUPERBLOCK_CSUM_XOR));
if (csum_le != disk_super->csum) {
DMERR("%s failed: csum %u: wanted %u",
__func__, le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));
return -EILSEQ;
}
return 0;
}
static struct dm_block_validator sb_validator = {
.name = "superblock",
.prepare_for_write = sb_prepare_for_write,
.check = sb_check
};
/*
*--------------------------------------------------------------
* Methods for the btree value types
*--------------------------------------------------------------
*/
static uint64_t pack_block_time(dm_block_t b, uint32_t t)
{
return (b << 24) | t;
}
static void unpack_block_time(uint64_t v, dm_block_t *b, uint32_t *t)
{
*b = v >> 24;
*t = v & ((1 << 24) - 1);
}
/*
* It's more efficient to call dm_sm_{inc,dec}_blocks as few times as
* possible. 'with_runs' reads contiguous runs of blocks, and calls the
* given sm function.
*/
typedef int (*run_fn)(struct dm_space_map *, dm_block_t, dm_block_t);
static void with_runs(struct dm_space_map *sm, const __le64 *value_le, unsigned int count, run_fn fn)
{
uint64_t b, begin, end;
uint32_t t;
bool in_run = false;
unsigned int i;
for (i = 0; i < count; i++, value_le++) {
/* We know value_le is 8 byte aligned */
unpack_block_time(le64_to_cpu(*value_le), &b, &t);
if (in_run) {
if (b == end) {
end++;
} else {
fn(sm, begin, end);
begin = b;
end = b + 1;
}
} else {
in_run = true;
begin = b;
end = b + 1;
}
}
if (in_run)
fn(sm, begin, end);
}
static void data_block_inc(void *context, const void *value_le, unsigned int count)
{
with_runs((struct dm_space_map *) context,
(const __le64 *) value_le, count, dm_sm_inc_blocks);
}
static void data_block_dec(void *context, const void *value_le, unsigned int count)
{
with_runs((struct dm_space_map *) context,
(const __le64 *) value_le, count, dm_sm_dec_blocks);
}
static int data_block_equal(void *context, const void *value1_le, const void *value2_le)
{
__le64 v1_le, v2_le;
uint64_t b1, b2;
uint32_t t;
memcpy(&v1_le, value1_le, sizeof(v1_le));
memcpy(&v2_le, value2_le, sizeof(v2_le));
unpack_block_time(le64_to_cpu(v1_le), &b1, &t);
unpack_block_time(le64_to_cpu(v2_le), &b2, &t);
return b1 == b2;
}
static void subtree_inc(void *context, const void *value, unsigned int count)
{
struct dm_btree_info *info = context;
const __le64 *root_le = value;
unsigned int i;
for (i = 0; i < count; i++, root_le++)
dm_tm_inc(info->tm, le64_to_cpu(*root_le));
}
static void subtree_dec(void *context, const void *value, unsigned int count)
{
struct dm_btree_info *info = context;
const __le64 *root_le = value;
unsigned int i;
for (i = 0; i < count; i++, root_le++)
if (dm_btree_del(info, le64_to_cpu(*root_le)))
DMERR("btree delete failed");
}
static int subtree_equal(void *context, const void *value1_le, const void *value2_le)
{
__le64 v1_le, v2_le;
memcpy(&v1_le, value1_le, sizeof(v1_le));
memcpy(&v2_le, value2_le, sizeof(v2_le));
return v1_le == v2_le;
}
/*----------------------------------------------------------------*/
/*
* Variant that is used for in-core only changes or code that
* shouldn't put the pool in service on its own (e.g. commit).
*/
static inline void pmd_write_lock_in_core(struct dm_pool_metadata *pmd)
__acquires(pmd->root_lock)
{
down_write(&pmd->root_lock);
}
static inline void pmd_write_lock(struct dm_pool_metadata *pmd)
{
pmd_write_lock_in_core(pmd);
if (unlikely(!pmd->in_service))
pmd->in_service = true;
}
static inline void pmd_write_unlock(struct dm_pool_metadata *pmd)
__releases(pmd->root_lock)
{
up_write(&pmd->root_lock);
}
/*----------------------------------------------------------------*/
static int superblock_lock_zero(struct dm_pool_metadata *pmd,
struct dm_block **sblock)
{
return dm_bm_write_lock_zero(pmd->bm, THIN_SUPERBLOCK_LOCATION,
&sb_validator, sblock);
}
static int superblock_lock(struct dm_pool_metadata *pmd,
struct dm_block **sblock)
{
return dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
&sb_validator, sblock);
}
static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result)
{
int r;
unsigned int i;
struct dm_block *b;
__le64 *data_le, zero = cpu_to_le64(0);
unsigned int block_size = dm_bm_block_size(bm) / sizeof(__le64);
/*
* We can't use a validator here - it may be all zeroes.
*/
r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION, NULL, &b);
if (r)
return r;
data_le = dm_block_data(b);
*result = 1;
for (i = 0; i < block_size; i++) {
if (data_le[i] != zero) {
*result = 0;
break;
}
}
dm_bm_unlock(b);
return 0;
}
static void __setup_btree_details(struct dm_pool_metadata *pmd)
{
pmd->info.tm = pmd->tm;
pmd->info.levels = 2;
pmd->info.value_type.context = pmd->data_sm;
pmd->info.value_type.size = sizeof(__le64);
pmd->info.value_type.inc = data_block_inc;
pmd->info.value_type.dec = data_block_dec;
pmd->info.value_type.equal = data_block_equal;
memcpy(&pmd->nb_info, &pmd->info, sizeof(pmd->nb_info));
pmd->nb_info.tm = pmd->nb_tm;
pmd->tl_info.tm = pmd->tm;
pmd->tl_info.levels = 1;
pmd->tl_info.value_type.context = &pmd->bl_info;
pmd->tl_info.value_type.size = sizeof(__le64);
pmd->tl_info.value_type.inc = subtree_inc;
pmd->tl_info.value_type.dec = subtree_dec;
pmd->tl_info.value_type.equal = subtree_equal;
pmd->bl_info.tm = pmd->tm;
pmd->bl_info.levels = 1;
pmd->bl_info.value_type.context = pmd->data_sm;
pmd->bl_info.value_type.size = sizeof(__le64);
pmd->bl_info.value_type.inc = data_block_inc;
pmd->bl_info.value_type.dec = data_block_dec;
pmd->bl_info.value_type.equal = data_block_equal;
pmd->details_info.tm = pmd->tm;
pmd->details_info.levels = 1;
pmd->details_info.value_type.context = NULL;
pmd->details_info.value_type.size = sizeof(struct disk_device_details);
pmd->details_info.value_type.inc = NULL;
pmd->details_info.value_type.dec = NULL;
pmd->details_info.value_type.equal = NULL;
}
static int save_sm_roots(struct dm_pool_metadata *pmd)
{
int r;
size_t len;
r = dm_sm_root_size(pmd->metadata_sm, &len);
if (r < 0)
return r;
r = dm_sm_copy_root(pmd->metadata_sm, &pmd->metadata_space_map_root, len);
if (r < 0)
return r;
r = dm_sm_root_size(pmd->data_sm, &len);
if (r < 0)
return r;
return dm_sm_copy_root(pmd->data_sm, &pmd->data_space_map_root, len);
}
static void copy_sm_roots(struct dm_pool_metadata *pmd,
struct thin_disk_superblock *disk)
{
memcpy(&disk->metadata_space_map_root,
&pmd->metadata_space_map_root,
sizeof(pmd->metadata_space_map_root));
memcpy(&disk->data_space_map_root,
&pmd->data_space_map_root,
sizeof(pmd->data_space_map_root));
}
static int __write_initial_superblock(struct dm_pool_metadata *pmd)
{
int r;
struct dm_block *sblock;
struct thin_disk_superblock *disk_super;
sector_t bdev_size = bdev_nr_sectors(pmd->bdev);
if (bdev_size > THIN_METADATA_MAX_SECTORS)
bdev_size = THIN_METADATA_MAX_SECTORS;
r = dm_sm_commit(pmd->data_sm);
if (r < 0)
return r;
r = dm_tm_pre_commit(pmd->tm);
if (r < 0)
return r;
r = save_sm_roots(pmd);
if (r < 0)
return r;
r = superblock_lock_zero(pmd, &sblock);
if (r)
return r;
disk_super = dm_block_data(sblock);
disk_super->flags = 0;
memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC);
disk_super->version = cpu_to_le32(THIN_VERSION);
disk_super->time = 0;
disk_super->trans_id = 0;
disk_super->held_root = 0;
copy_sm_roots(pmd, disk_super);
disk_super->data_mapping_root = cpu_to_le64(pmd->root);
disk_super->device_details_root = cpu_to_le64(pmd->details_root);
disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE);
disk_super->metadata_nr_blocks = cpu_to_le64(bdev_size >> SECTOR_TO_BLOCK_SHIFT);
disk_super->data_block_size = cpu_to_le32(pmd->data_block_size);
return dm_tm_commit(pmd->tm, sblock);
}
static int __format_metadata(struct dm_pool_metadata *pmd)
{
int r;
r = dm_tm_create_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
&pmd->tm, &pmd->metadata_sm);
if (r < 0) {
pmd->tm = NULL;
pmd->metadata_sm = NULL;
DMERR("tm_create_with_sm failed");
return r;
}
pmd->data_sm = dm_sm_disk_create(pmd->tm, 0);
if (IS_ERR(pmd->data_sm)) {
DMERR("sm_disk_create failed");
r = PTR_ERR(pmd->data_sm);
pmd->data_sm = NULL;
goto bad_cleanup_tm;
}
pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
if (!pmd->nb_tm) {
DMERR("could not create non-blocking clone tm");
r = -ENOMEM;
goto bad_cleanup_data_sm;
}
__setup_btree_details(pmd);
r = dm_btree_empty(&pmd->info, &pmd->root);
if (r < 0)
goto bad_cleanup_nb_tm;
r = dm_btree_empty(&pmd->details_info, &pmd->details_root);
if (r < 0) {
DMERR("couldn't create devices root");
goto bad_cleanup_nb_tm;
}
r = __write_initial_superblock(pmd);
if (r)
goto bad_cleanup_nb_tm;
return 0;
bad_cleanup_nb_tm:
dm_tm_destroy(pmd->nb_tm);
pmd->nb_tm = NULL;
bad_cleanup_data_sm:
dm_sm_destroy(pmd->data_sm);
pmd->data_sm = NULL;
bad_cleanup_tm:
dm_tm_destroy(pmd->tm);
pmd->tm = NULL;
dm_sm_destroy(pmd->metadata_sm);
pmd->metadata_sm = NULL;
return r;
}
static int __check_incompat_features(struct thin_disk_superblock *disk_super,
struct dm_pool_metadata *pmd)
{
uint32_t features;
features = le32_to_cpu(disk_super->incompat_flags) & ~THIN_FEATURE_INCOMPAT_SUPP;
if (features) {
DMERR("could not access metadata due to unsupported optional features (%lx).",
(unsigned long)features);
return -EINVAL;
}
/*
* Check for read-only metadata to skip the following RDWR checks.
*/
if (bdev_read_only(pmd->bdev))
return 0;
features = le32_to_cpu(disk_super->compat_ro_flags) & ~THIN_FEATURE_COMPAT_RO_SUPP;
if (features) {
DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",
(unsigned long)features);
return -EINVAL;
}
return 0;
}
static int __open_metadata(struct dm_pool_metadata *pmd)
{
int r;
struct dm_block *sblock;
struct thin_disk_superblock *disk_super;
r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
&sb_validator, &sblock);
if (r < 0) {
DMERR("couldn't read superblock");
return r;
}
disk_super = dm_block_data(sblock);
/* Verify the data block size hasn't changed */
if (le32_to_cpu(disk_super->data_block_size) != pmd->data_block_size) {
DMERR("changing the data block size (from %u to %llu) is not supported",
le32_to_cpu(disk_super->data_block_size),
(unsigned long long)pmd->data_block_size);
r = -EINVAL;
goto bad_unlock_sblock;
}
r = __check_incompat_features(disk_super, pmd);
if (r < 0)
goto bad_unlock_sblock;
r = dm_tm_open_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
disk_super->metadata_space_map_root,
sizeof(disk_super->metadata_space_map_root),
&pmd->tm, &pmd->metadata_sm);
if (r < 0) {
pmd->tm = NULL;
pmd->metadata_sm = NULL;
DMERR("tm_open_with_sm failed");
goto bad_unlock_sblock;
}
pmd->data_sm = dm_sm_disk_open(pmd->tm, disk_super->data_space_map_root,
sizeof(disk_super->data_space_map_root));
if (IS_ERR(pmd->data_sm)) {
DMERR("sm_disk_open failed");
r = PTR_ERR(pmd->data_sm);
pmd->data_sm = NULL;
goto bad_cleanup_tm;
}
pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
if (!pmd->nb_tm) {
DMERR("could not create non-blocking clone tm");
r = -ENOMEM;
goto bad_cleanup_data_sm;
}
/*
* For pool metadata opening process, root setting is redundant
* because it will be set again in __begin_transaction(). But dm
* pool aborting process really needs to get last transaction's
* root to avoid accessing broken btree.
*/
pmd->root = le64_to_cpu(disk_super->data_mapping_root);
pmd->details_root = le64_to_cpu(disk_super->device_details_root);
__setup_btree_details(pmd);
dm_bm_unlock(sblock);
return 0;
bad_cleanup_data_sm:
dm_sm_destroy(pmd->data_sm);
pmd->data_sm = NULL;
bad_cleanup_tm:
dm_tm_destroy(pmd->tm);
pmd->tm = NULL;
dm_sm_destroy(pmd->metadata_sm);
pmd->metadata_sm = NULL;
bad_unlock_sblock:
dm_bm_unlock(sblock);
return r;
}
static int __open_or_format_metadata(struct dm_pool_metadata *pmd, bool format_device)
{
int r, unformatted;
r = __superblock_all_zeroes(pmd->bm, &unformatted);
if (r)
return r;
if (unformatted)
return format_device ? __format_metadata(pmd) : -EPERM;
return __open_metadata(pmd);
}
static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool format_device)
{
int r;
pmd->bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
THIN_MAX_CONCURRENT_LOCKS);
if (IS_ERR(pmd->bm)) {
DMERR("could not create block manager");
r = PTR_ERR(pmd->bm);
pmd->bm = NULL;
return r;
}
r = __open_or_format_metadata(pmd, format_device);
if (r) {
dm_block_manager_destroy(pmd->bm);
pmd->bm = NULL;
}
return r;
}
static void __destroy_persistent_data_objects(struct dm_pool_metadata *pmd,
bool destroy_bm)
{
dm_sm_destroy(pmd->data_sm);
pmd->data_sm = NULL;
dm_sm_destroy(pmd->metadata_sm);
pmd->metadata_sm = NULL;
dm_tm_destroy(pmd->nb_tm);
pmd->nb_tm = NULL;
dm_tm_destroy(pmd->tm);
pmd->tm = NULL;
if (destroy_bm)
dm_block_manager_destroy(pmd->bm);
}
static int __begin_transaction(struct dm_pool_metadata *pmd)
{
int r;
struct thin_disk_superblock *disk_super;
struct dm_block *sblock;
/*
* We re-read the superblock every time. Shouldn't need to do this
* really.
*/
r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
&sb_validator, &sblock);
if (r)
return r;
disk_super = dm_block_data(sblock);
pmd->time = le32_to_cpu(disk_super->time);
pmd->root = le64_to_cpu(disk_super->data_mapping_root);
pmd->details_root = le64_to_cpu(disk_super->device_details_root);
pmd->trans_id = le64_to_cpu(disk_super->trans_id);
pmd->flags = le32_to_cpu(disk_super->flags);
pmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
dm_bm_unlock(sblock);
return 0;
}
static int __write_changed_details(struct dm_pool_metadata *pmd)
{
int r;
struct dm_thin_device *td, *tmp;
struct disk_device_details details;
uint64_t key;
list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
if (!td->changed)
continue;
key = td->id;
details.mapped_blocks = cpu_to_le64(td->mapped_blocks);
details.transaction_id = cpu_to_le64(td->transaction_id);
details.creation_time = cpu_to_le32(td->creation_time);
details.snapshotted_time = cpu_to_le32(td->snapshotted_time);
__dm_bless_for_disk(&details);
r = dm_btree_insert(&pmd->details_info, pmd->details_root,
&key, &details, &pmd->details_root);
if (r)
return r;
if (td->open_count)
td->changed = false;
else {
list_del(&td->list);
kfree(td);
}
}
return 0;
}
static int __commit_transaction(struct dm_pool_metadata *pmd)
{
int r;
struct thin_disk_superblock *disk_super;
struct dm_block *sblock;
/*
* We need to know if the thin_disk_superblock exceeds a 512-byte sector.
*/
BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512);
BUG_ON(!rwsem_is_locked(&pmd->root_lock));
if (unlikely(!pmd->in_service))
return 0;
if (pmd->pre_commit_fn) {
r = pmd->pre_commit_fn(pmd->pre_commit_context);
if (r < 0) {
DMERR("pre-commit callback failed");
return r;
}
}
r = __write_changed_details(pmd);
if (r < 0)
return r;
r = dm_sm_commit(pmd->data_sm);
if (r < 0)
return r;
r = dm_tm_pre_commit(pmd->tm);
if (r < 0)
return r;
r = save_sm_roots(pmd);
if (r < 0)
return r;
r = superblock_lock(pmd, &sblock);
if (r)
return r;
disk_super = dm_block_data(sblock);
disk_super->time = cpu_to_le32(pmd->time);
disk_super->data_mapping_root = cpu_to_le64(pmd->root);
disk_super->device_details_root = cpu_to_le64(pmd->details_root);
disk_super->trans_id = cpu_to_le64(pmd->trans_id);
disk_super->flags = cpu_to_le32(pmd->flags);
copy_sm_roots(pmd, disk_super);
return dm_tm_commit(pmd->tm, sblock);
}
static void __set_metadata_reserve(struct dm_pool_metadata *pmd)
{
int r;
dm_block_t total;
dm_block_t max_blocks = 4096; /* 16M */
r = dm_sm_get_nr_blocks(pmd->metadata_sm, &total);
if (r) {
DMERR("could not get size of metadata device");
pmd->metadata_reserve = max_blocks;
} else
pmd->metadata_reserve = min(max_blocks, div_u64(total, 10));
}
struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
sector_t data_block_size,
bool format_device)
{
int r;
struct dm_pool_metadata *pmd;
pmd = kmalloc(sizeof(*pmd), GFP_KERNEL);
if (!pmd) {
DMERR("could not allocate metadata struct");
return ERR_PTR(-ENOMEM);
}
init_rwsem(&pmd->root_lock);
pmd->time = 0;
INIT_LIST_HEAD(&pmd->thin_devices);
pmd->fail_io = false;
pmd->in_service = false;
pmd->bdev = bdev;
pmd->data_block_size = data_block_size;
pmd->pre_commit_fn = NULL;
pmd->pre_commit_context = NULL;
r = __create_persistent_data_objects(pmd, format_device);
if (r) {
kfree(pmd);
return ERR_PTR(r);
}
r = __begin_transaction(pmd);
if (r < 0) {
if (dm_pool_metadata_close(pmd) < 0)
DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
return ERR_PTR(r);
}
__set_metadata_reserve(pmd);
return pmd;
}
int dm_pool_metadata_close(struct dm_pool_metadata *pmd)
{
int r;
unsigned int open_devices = 0;
struct dm_thin_device *td, *tmp;
down_read(&pmd->root_lock);
list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
if (td->open_count)
open_devices++;
else {
list_del(&td->list);
kfree(td);
}
}
up_read(&pmd->root_lock);
if (open_devices) {
DMERR("attempt to close pmd when %u device(s) are still open",
open_devices);
return -EBUSY;
}
pmd_write_lock_in_core(pmd);
if (!pmd->fail_io && !dm_bm_is_read_only(pmd->bm)) {
r = __commit_transaction(pmd);
if (r < 0)
DMWARN("%s: __commit_transaction() failed, error = %d",
__func__, r);
}
pmd_write_unlock(pmd);
__destroy_persistent_data_objects(pmd, true);
kfree(pmd);
return 0;
}
/*
* __open_device: Returns @td corresponding to device with id @dev,
* creating it if @create is set and incrementing @td->open_count.
* On failure, @td is undefined.
*/
static int __open_device(struct dm_pool_metadata *pmd,
dm_thin_id dev, int create,
struct dm_thin_device **td)
{
int r, changed = 0;
struct dm_thin_device *td2;
uint64_t key = dev;
struct disk_device_details details_le;
/*
* If the device is already open, return it.
*/
list_for_each_entry(td2, &pmd->thin_devices, list)
if (td2->id == dev) {
/*
* May not create an already-open device.
*/
if (create)
return -EEXIST;
td2->open_count++;
*td = td2;
return 0;
}
/*
* Check the device exists.
*/
r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
&key, &details_le);
if (r) {
if (r != -ENODATA || !create)
return r;
/*
* Create new device.
*/
changed = 1;
details_le.mapped_blocks = 0;
details_le.transaction_id = cpu_to_le64(pmd->trans_id);
details_le.creation_time = cpu_to_le32(pmd->time);
details_le.snapshotted_time = cpu_to_le32(pmd->time);
}
*td = kmalloc(sizeof(**td), GFP_NOIO);
if (!*td)
return -ENOMEM;
(*td)->pmd = pmd;
(*td)->id = dev;
(*td)->open_count = 1;
(*td)->changed = changed;
(*td)->aborted_with_changes = false;
(*td)->mapped_blocks = le64_to_cpu(details_le.mapped_blocks);
(*td)->transaction_id = le64_to_cpu(details_le.transaction_id);
(*td)->creation_time = le32_to_cpu(details_le.creation_time);
(*td)->snapshotted_time = le32_to_cpu(details_le.snapshotted_time);
list_add(&(*td)->list, &pmd->thin_devices);
return 0;
}
static void __close_device(struct dm_thin_device *td)
{
--td->open_count;
}
static int __create_thin(struct dm_pool_metadata *pmd,
dm_thin_id dev)
{
int r;
dm_block_t dev_root;
uint64_t key = dev;
struct dm_thin_device *td;
__le64 value;
r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
&key, NULL);
if (!r)
return -EEXIST;
/*
* Create an empty btree for the mappings.
*/
r = dm_btree_empty(&pmd->bl_info, &dev_root);
if (r)
return r;
/*
* Insert it into the main mapping tree.
*/
value = cpu_to_le64(dev_root);
__dm_bless_for_disk(&value);
r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
if (r) {
dm_btree_del(&pmd->bl_info, dev_root);
return r;
}
r = __open_device(pmd, dev, 1, &td);
if (r) {
dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
dm_btree_del(&pmd->bl_info, dev_root);
return r;
}
__close_device(td);
return r;
}
int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io)
r = __create_thin(pmd, dev);
pmd_write_unlock(pmd);
return r;
}
static int __set_snapshot_details(struct dm_pool_metadata *pmd,
struct dm_thin_device *snap,
dm_thin_id origin, uint32_t time)
{
int r;
struct dm_thin_device *td;
r = __open_device(pmd, origin, 0, &td);
if (r)
return r;
td->changed = true;
td->snapshotted_time = time;
snap->mapped_blocks = td->mapped_blocks;
snap->snapshotted_time = time;
__close_device(td);
return 0;
}
static int __create_snap(struct dm_pool_metadata *pmd,
dm_thin_id dev, dm_thin_id origin)
{
int r;
dm_block_t origin_root;
uint64_t key = origin, dev_key = dev;
struct dm_thin_device *td;
__le64 value;
/* check this device is unused */
r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
&dev_key, NULL);
if (!r)
return -EEXIST;
/* find the mapping tree for the origin */
r = dm_btree_lookup(&pmd->tl_info, pmd->root, &key, &value);
if (r)
return r;
origin_root = le64_to_cpu(value);
/* clone the origin, an inc will do */
dm_tm_inc(pmd->tm, origin_root);
/* insert into the main mapping tree */
value = cpu_to_le64(origin_root);
__dm_bless_for_disk(&value);
key = dev;
r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
if (r) {
dm_tm_dec(pmd->tm, origin_root);
return r;
}
pmd->time++;
r = __open_device(pmd, dev, 1, &td);
if (r)
goto bad;
r = __set_snapshot_details(pmd, td, origin, pmd->time);
__close_device(td);
if (r)
goto bad;
return 0;
bad:
dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
dm_btree_remove(&pmd->details_info, pmd->details_root,
&key, &pmd->details_root);
return r;
}
int dm_pool_create_snap(struct dm_pool_metadata *pmd,
dm_thin_id dev,
dm_thin_id origin)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io)
r = __create_snap(pmd, dev, origin);
pmd_write_unlock(pmd);
return r;
}
static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev)
{
int r;
uint64_t key = dev;
struct dm_thin_device *td;
/* TODO: failure should mark the transaction invalid */
r = __open_device(pmd, dev, 0, &td);
if (r)
return r;
if (td->open_count > 1) {
__close_device(td);
return -EBUSY;
}
list_del(&td->list);
kfree(td);
r = dm_btree_remove(&pmd->details_info, pmd->details_root,
&key, &pmd->details_root);
if (r)
return r;
r = dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
if (r)
return r;
return 0;
}
int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
dm_thin_id dev)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io)
r = __delete_device(pmd, dev);
pmd_write_unlock(pmd);
return r;
}
int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
uint64_t current_id,
uint64_t new_id)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (pmd->fail_io)
goto out;
if (pmd->trans_id != current_id) {
DMERR("mismatched transaction id");
goto out;
}
pmd->trans_id = new_id;
r = 0;
out:
pmd_write_unlock(pmd);
return r;
}
int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,
uint64_t *result)
{
int r = -EINVAL;
down_read(&pmd->root_lock);
if (!pmd->fail_io) {
*result = pmd->trans_id;
r = 0;
}
up_read(&pmd->root_lock);
return r;
}
static int __reserve_metadata_snap(struct dm_pool_metadata *pmd)
{
int r, inc;
struct thin_disk_superblock *disk_super;
struct dm_block *copy, *sblock;
dm_block_t held_root;
/*
* We commit to ensure the btree roots which we increment in a
* moment are up to date.
*/
r = __commit_transaction(pmd);
if (r < 0) {
DMWARN("%s: __commit_transaction() failed, error = %d",
__func__, r);
return r;
}
/*
* Copy the superblock.
*/
dm_sm_inc_block(pmd->metadata_sm, THIN_SUPERBLOCK_LOCATION);
r = dm_tm_shadow_block(pmd->tm, THIN_SUPERBLOCK_LOCATION,
&sb_validator, ©, &inc);
if (r)
return r;
BUG_ON(!inc);
held_root = dm_block_location(copy);
disk_super = dm_block_data(copy);
if (le64_to_cpu(disk_super->held_root)) {
DMWARN("Pool metadata snapshot already exists: release this before taking another.");
dm_tm_dec(pmd->tm, held_root);
dm_tm_unlock(pmd->tm, copy);
return -EBUSY;
}
/*
* Wipe the spacemap since we're not publishing this.
*/
memset(&disk_super->data_space_map_root, 0,
sizeof(disk_super->data_space_map_root));
memset(&disk_super->metadata_space_map_root, 0,
sizeof(disk_super->metadata_space_map_root));
/*
* Increment the data structures that need to be preserved.
*/
dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->data_mapping_root));
dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->device_details_root));
dm_tm_unlock(pmd->tm, copy);
/*
* Write the held root into the superblock.
*/
r = superblock_lock(pmd, &sblock);
if (r) {
dm_tm_dec(pmd->tm, held_root);
return r;
}
disk_super = dm_block_data(sblock);
disk_super->held_root = cpu_to_le64(held_root);
dm_bm_unlock(sblock);
return 0;
}
int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io)
r = __reserve_metadata_snap(pmd);
pmd_write_unlock(pmd);
return r;
}
static int __release_metadata_snap(struct dm_pool_metadata *pmd)
{
int r;
struct thin_disk_superblock *disk_super;
struct dm_block *sblock, *copy;
dm_block_t held_root;
r = superblock_lock(pmd, &sblock);
if (r)
return r;
disk_super = dm_block_data(sblock);
held_root = le64_to_cpu(disk_super->held_root);
disk_super->held_root = cpu_to_le64(0);
dm_bm_unlock(sblock);
if (!held_root) {
DMWARN("No pool metadata snapshot found: nothing to release.");
return -EINVAL;
}
r = dm_tm_read_lock(pmd->tm, held_root, &sb_validator, ©);
if (r)
return r;
disk_super = dm_block_data(copy);
dm_btree_del(&pmd->info, le64_to_cpu(disk_super->data_mapping_root));
dm_btree_del(&pmd->details_info, le64_to_cpu(disk_super->device_details_root));
dm_sm_dec_block(pmd->metadata_sm, held_root);
dm_tm_unlock(pmd->tm, copy);
return 0;
}
int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io)
r = __release_metadata_snap(pmd);
pmd_write_unlock(pmd);
return r;
}
static int __get_metadata_snap(struct dm_pool_metadata *pmd,
dm_block_t *result)
{
int r;
struct thin_disk_superblock *disk_super;
struct dm_block *sblock;
r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
&sb_validator, &sblock);
if (r)
return r;
disk_super = dm_block_data(sblock);
*result = le64_to_cpu(disk_super->held_root);
dm_bm_unlock(sblock);
return 0;
}
int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd,
dm_block_t *result)
{
int r = -EINVAL;
down_read(&pmd->root_lock);
if (!pmd->fail_io)
r = __get_metadata_snap(pmd, result);
up_read(&pmd->root_lock);
return r;
}
int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
struct dm_thin_device **td)
{
int r = -EINVAL;
pmd_write_lock_in_core(pmd);
if (!pmd->fail_io)
r = __open_device(pmd, dev, 0, td);
pmd_write_unlock(pmd);
return r;
}
int dm_pool_close_thin_device(struct dm_thin_device *td)
{
pmd_write_lock_in_core(td->pmd);
__close_device(td);
pmd_write_unlock(td->pmd);
return 0;
}
dm_thin_id dm_thin_dev_id(struct dm_thin_device *td)
{
return td->id;
}
/*
* Check whether @time (of block creation) is older than @td's last snapshot.
* If so then the associated block is shared with the last snapshot device.
* Any block on a device created *after* the device last got snapshotted is
* necessarily not shared.
*/
static bool __snapshotted_since(struct dm_thin_device *td, uint32_t time)
{
return td->snapshotted_time > time;
}
static void unpack_lookup_result(struct dm_thin_device *td, __le64 value,
struct dm_thin_lookup_result *result)
{
uint64_t block_time = 0;
dm_block_t exception_block;
uint32_t exception_time;
block_time = le64_to_cpu(value);
unpack_block_time(block_time, &exception_block, &exception_time);
result->block = exception_block;
result->shared = __snapshotted_since(td, exception_time);
}
static int __find_block(struct dm_thin_device *td, dm_block_t block,
int can_issue_io, struct dm_thin_lookup_result *result)
{
int r;
__le64 value;
struct dm_pool_metadata *pmd = td->pmd;
dm_block_t keys[2] = { td->id, block };
struct dm_btree_info *info;
if (can_issue_io)
info = &pmd->info;
else
info = &pmd->nb_info;
r = dm_btree_lookup(info, pmd->root, keys, &value);
if (!r)
unpack_lookup_result(td, value, result);
return r;
}
int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
int can_issue_io, struct dm_thin_lookup_result *result)
{
int r;
struct dm_pool_metadata *pmd = td->pmd;
down_read(&pmd->root_lock);
if (pmd->fail_io) {
up_read(&pmd->root_lock);
return -EINVAL;
}
r = __find_block(td, block, can_issue_io, result);
up_read(&pmd->root_lock);
return r;
}
static int __find_next_mapped_block(struct dm_thin_device *td, dm_block_t block,
dm_block_t *vblock,
struct dm_thin_lookup_result *result)
{
int r;
__le64 value;
struct dm_pool_metadata *pmd = td->pmd;
dm_block_t keys[2] = { td->id, block };
r = dm_btree_lookup_next(&pmd->info, pmd->root, keys, vblock, &value);
if (!r)
unpack_lookup_result(td, value, result);
return r;
}
static int __find_mapped_range(struct dm_thin_device *td,
dm_block_t begin, dm_block_t end,
dm_block_t *thin_begin, dm_block_t *thin_end,
dm_block_t *pool_begin, bool *maybe_shared)
{
int r;
dm_block_t pool_end;
struct dm_thin_lookup_result lookup;
if (end < begin)
return -ENODATA;
r = __find_next_mapped_block(td, begin, &begin, &lookup);
if (r)
return r;
if (begin >= end)
return -ENODATA;
*thin_begin = begin;
*pool_begin = lookup.block;
*maybe_shared = lookup.shared;
begin++;
pool_end = *pool_begin + 1;
while (begin != end) {
r = __find_block(td, begin, true, &lookup);
if (r) {
if (r == -ENODATA)
break;
return r;
}
if ((lookup.block != pool_end) ||
(lookup.shared != *maybe_shared))
break;
pool_end++;
begin++;
}
*thin_end = begin;
return 0;
}
int dm_thin_find_mapped_range(struct dm_thin_device *td,
dm_block_t begin, dm_block_t end,
dm_block_t *thin_begin, dm_block_t *thin_end,
dm_block_t *pool_begin, bool *maybe_shared)
{
int r = -EINVAL;
struct dm_pool_metadata *pmd = td->pmd;
down_read(&pmd->root_lock);
if (!pmd->fail_io) {
r = __find_mapped_range(td, begin, end, thin_begin, thin_end,
pool_begin, maybe_shared);
}
up_read(&pmd->root_lock);
return r;
}
static int __insert(struct dm_thin_device *td, dm_block_t block,
dm_block_t data_block)
{
int r, inserted;
__le64 value;
struct dm_pool_metadata *pmd = td->pmd;
dm_block_t keys[2] = { td->id, block };
value = cpu_to_le64(pack_block_time(data_block, pmd->time));
__dm_bless_for_disk(&value);
r = dm_btree_insert_notify(&pmd->info, pmd->root, keys, &value,
&pmd->root, &inserted);
if (r)
return r;
td->changed = true;
if (inserted)
td->mapped_blocks++;
return 0;
}
int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
dm_block_t data_block)
{
int r = -EINVAL;
pmd_write_lock(td->pmd);
if (!td->pmd->fail_io)
r = __insert(td, block, data_block);
pmd_write_unlock(td->pmd);
return r;
}
static int __remove_range(struct dm_thin_device *td, dm_block_t begin, dm_block_t end)
{
int r;
unsigned int count, total_count = 0;
struct dm_pool_metadata *pmd = td->pmd;
dm_block_t keys[1] = { td->id };
__le64 value;
dm_block_t mapping_root;
/*
* Find the mapping tree
*/
r = dm_btree_lookup(&pmd->tl_info, pmd->root, keys, &value);
if (r)
return r;
/*
* Remove from the mapping tree, taking care to inc the
* ref count so it doesn't get deleted.
*/
mapping_root = le64_to_cpu(value);
dm_tm_inc(pmd->tm, mapping_root);
r = dm_btree_remove(&pmd->tl_info, pmd->root, keys, &pmd->root);
if (r)
return r;
/*
* Remove leaves stops at the first unmapped entry, so we have to
* loop round finding mapped ranges.
*/
while (begin < end) {
r = dm_btree_lookup_next(&pmd->bl_info, mapping_root, &begin, &begin, &value);
if (r == -ENODATA)
break;
if (r)
return r;
if (begin >= end)
break;
r = dm_btree_remove_leaves(&pmd->bl_info, mapping_root, &begin, end, &mapping_root, &count);
if (r)
return r;
total_count += count;
}
td->mapped_blocks -= total_count;
td->changed = true;
/*
* Reinsert the mapping tree.
*/
value = cpu_to_le64(mapping_root);
__dm_bless_for_disk(&value);
return dm_btree_insert(&pmd->tl_info, pmd->root, keys, &value, &pmd->root);
}
int dm_thin_remove_range(struct dm_thin_device *td,
dm_block_t begin, dm_block_t end)
{
int r = -EINVAL;
pmd_write_lock(td->pmd);
if (!td->pmd->fail_io)
r = __remove_range(td, begin, end);
pmd_write_unlock(td->pmd);
return r;
}
int dm_pool_block_is_shared(struct dm_pool_metadata *pmd, dm_block_t b, bool *result)
{
int r = -EINVAL;
uint32_t ref_count;
down_read(&pmd->root_lock);
if (!pmd->fail_io) {
r = dm_sm_get_count(pmd->data_sm, b, &ref_count);
if (!r)
*result = (ref_count > 1);
}
up_read(&pmd->root_lock);
return r;
}
int dm_pool_inc_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io)
r = dm_sm_inc_blocks(pmd->data_sm, b, e);
pmd_write_unlock(pmd);
return r;
}
int dm_pool_dec_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io)
r = dm_sm_dec_blocks(pmd->data_sm, b, e);
pmd_write_unlock(pmd);
return r;
}
bool dm_thin_changed_this_transaction(struct dm_thin_device *td)
{
int r;
down_read(&td->pmd->root_lock);
r = td->changed;
up_read(&td->pmd->root_lock);
return r;
}
bool dm_pool_changed_this_transaction(struct dm_pool_metadata *pmd)
{
bool r = false;
struct dm_thin_device *td, *tmp;
down_read(&pmd->root_lock);
list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
if (td->changed) {
r = td->changed;
break;
}
}
up_read(&pmd->root_lock);
return r;
}
bool dm_thin_aborted_changes(struct dm_thin_device *td)
{
bool r;
down_read(&td->pmd->root_lock);
r = td->aborted_with_changes;
up_read(&td->pmd->root_lock);
return r;
}
int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io)
r = dm_sm_new_block(pmd->data_sm, result);
pmd_write_unlock(pmd);
return r;
}
int dm_pool_commit_metadata(struct dm_pool_metadata *pmd)
{
int r = -EINVAL;
/*
* Care is taken to not have commit be what
* triggers putting the thin-pool in-service.
*/
pmd_write_lock_in_core(pmd);
if (pmd->fail_io)
goto out;
r = __commit_transaction(pmd);
if (r < 0)
goto out;
/*
* Open the next transaction.
*/
r = __begin_transaction(pmd);
out:
pmd_write_unlock(pmd);
return r;
}
static void __set_abort_with_changes_flags(struct dm_pool_metadata *pmd)
{
struct dm_thin_device *td;
list_for_each_entry(td, &pmd->thin_devices, list)
td->aborted_with_changes = td->changed;
}
int dm_pool_abort_metadata(struct dm_pool_metadata *pmd)
{
int r = -EINVAL;
/* fail_io is double-checked with pmd->root_lock held below */
if (unlikely(pmd->fail_io))
return r;
pmd_write_lock(pmd);
if (pmd->fail_io) {
pmd_write_unlock(pmd);
return r;
}
__set_abort_with_changes_flags(pmd);
/* destroy data_sm/metadata_sm/nb_tm/tm */
__destroy_persistent_data_objects(pmd, false);
/* reset bm */
dm_block_manager_reset(pmd->bm);
/* rebuild data_sm/metadata_sm/nb_tm/tm */
r = __open_or_format_metadata(pmd, false);
if (r)
pmd->fail_io = true;
pmd_write_unlock(pmd);
return r;
}
int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result)
{
int r = -EINVAL;
down_read(&pmd->root_lock);
if (!pmd->fail_io)
r = dm_sm_get_nr_free(pmd->data_sm, result);
up_read(&pmd->root_lock);
return r;
}
int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
dm_block_t *result)
{
int r = -EINVAL;
down_read(&pmd->root_lock);
if (!pmd->fail_io)
r = dm_sm_get_nr_free(pmd->metadata_sm, result);
if (!r) {
if (*result < pmd->metadata_reserve)
*result = 0;
else
*result -= pmd->metadata_reserve;
}
up_read(&pmd->root_lock);
return r;
}
int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
dm_block_t *result)
{
int r = -EINVAL;
down_read(&pmd->root_lock);
if (!pmd->fail_io)
r = dm_sm_get_nr_blocks(pmd->metadata_sm, result);
up_read(&pmd->root_lock);
return r;
}
int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result)
{
int r = -EINVAL;
down_read(&pmd->root_lock);
if (!pmd->fail_io)
r = dm_sm_get_nr_blocks(pmd->data_sm, result);
up_read(&pmd->root_lock);
return r;
}
int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result)
{
int r = -EINVAL;
struct dm_pool_metadata *pmd = td->pmd;
down_read(&pmd->root_lock);
if (!pmd->fail_io) {
*result = td->mapped_blocks;
r = 0;
}
up_read(&pmd->root_lock);
return r;
}
static int __highest_block(struct dm_thin_device *td, dm_block_t *result)
{
int r;
__le64 value_le;
dm_block_t thin_root;
struct dm_pool_metadata *pmd = td->pmd;
r = dm_btree_lookup(&pmd->tl_info, pmd->root, &td->id, &value_le);
if (r)
return r;
thin_root = le64_to_cpu(value_le);
return dm_btree_find_highest_key(&pmd->bl_info, thin_root, result);
}
int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,
dm_block_t *result)
{
int r = -EINVAL;
struct dm_pool_metadata *pmd = td->pmd;
down_read(&pmd->root_lock);
if (!pmd->fail_io)
r = __highest_block(td, result);
up_read(&pmd->root_lock);
return r;
}
static int __resize_space_map(struct dm_space_map *sm, dm_block_t new_count)
{
int r;
dm_block_t old_count;
r = dm_sm_get_nr_blocks(sm, &old_count);
if (r)
return r;
if (new_count == old_count)
return 0;
if (new_count < old_count) {
DMERR("cannot reduce size of space map");
return -EINVAL;
}
return dm_sm_extend(sm, new_count - old_count);
}
int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io)
r = __resize_space_map(pmd->data_sm, new_count);
pmd_write_unlock(pmd);
return r;
}
int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
{
int r = -EINVAL;
pmd_write_lock(pmd);
if (!pmd->fail_io) {
r = __resize_space_map(pmd->metadata_sm, new_count);
if (!r)
__set_metadata_reserve(pmd);
}
pmd_write_unlock(pmd);
return r;
}
void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd)
{
pmd_write_lock_in_core(pmd);
dm_bm_set_read_only(pmd->bm);
pmd_write_unlock(pmd);
}
void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd)
{
pmd_write_lock_in_core(pmd);
dm_bm_set_read_write(pmd->bm);
pmd_write_unlock(pmd);
}
int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd,
dm_block_t threshold,
dm_sm_threshold_fn fn,
void *context)
{
int r = -EINVAL;
pmd_write_lock_in_core(pmd);
if (!pmd->fail_io) {
r = dm_sm_register_threshold_callback(pmd->metadata_sm,
threshold, fn, context);
}
pmd_write_unlock(pmd);
return r;
}
void dm_pool_register_pre_commit_callback(struct dm_pool_metadata *pmd,
dm_pool_pre_commit_fn fn,
void *context)
{
pmd_write_lock_in_core(pmd);
pmd->pre_commit_fn = fn;
pmd->pre_commit_context = context;
pmd_write_unlock(pmd);
}
int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd)
{
int r = -EINVAL;
struct dm_block *sblock;
struct thin_disk_superblock *disk_super;
pmd_write_lock(pmd);
if (pmd->fail_io)
goto out;
pmd->flags |= THIN_METADATA_NEEDS_CHECK_FLAG;
r = superblock_lock(pmd, &sblock);
if (r) {
DMERR("couldn't lock superblock");
goto out;
}
disk_super = dm_block_data(sblock);
disk_super->flags = cpu_to_le32(pmd->flags);
dm_bm_unlock(sblock);
out:
pmd_write_unlock(pmd);
return r;
}
bool dm_pool_metadata_needs_check(struct dm_pool_metadata *pmd)
{
bool needs_check;
down_read(&pmd->root_lock);
needs_check = pmd->flags & THIN_METADATA_NEEDS_CHECK_FLAG;
up_read(&pmd->root_lock);
return needs_check;
}
void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd)
{
down_read(&pmd->root_lock);
if (!pmd->fail_io)
dm_tm_issue_prefetches(pmd->tm);
up_read(&pmd->root_lock);
}
| linux-master | drivers/md/dm-thin-metadata.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Creating audit records for mapped devices.
*
* Copyright (C) 2021 Fraunhofer AISEC. All rights reserved.
*
* Authors: Michael Weiß <[email protected]>
*/
#include <linux/audit.h>
#include <linux/module.h>
#include <linux/device-mapper.h>
#include <linux/bio.h>
#include <linux/blkdev.h>
#include "dm-audit.h"
#include "dm-core.h"
static struct audit_buffer *dm_audit_log_start(int audit_type,
const char *dm_msg_prefix,
const char *op)
{
struct audit_buffer *ab;
if (audit_enabled == AUDIT_OFF)
return NULL;
ab = audit_log_start(audit_context(), GFP_KERNEL, audit_type);
if (unlikely(!ab))
return NULL;
audit_log_format(ab, "module=%s op=%s", dm_msg_prefix, op);
return ab;
}
void dm_audit_log_ti(int audit_type, const char *dm_msg_prefix, const char *op,
struct dm_target *ti, int result)
{
struct audit_buffer *ab = NULL;
struct mapped_device *md = dm_table_get_md(ti->table);
int dev_major = dm_disk(md)->major;
int dev_minor = dm_disk(md)->first_minor;
switch (audit_type) {
case AUDIT_DM_CTRL:
ab = dm_audit_log_start(audit_type, dm_msg_prefix, op);
if (unlikely(!ab))
return;
audit_log_task_info(ab);
audit_log_format(ab, " dev=%d:%d error_msg='%s'", dev_major,
dev_minor, !result ? ti->error : "success");
break;
case AUDIT_DM_EVENT:
ab = dm_audit_log_start(audit_type, dm_msg_prefix, op);
if (unlikely(!ab))
return;
audit_log_format(ab, " dev=%d:%d sector=?", dev_major,
dev_minor);
break;
default: /* unintended use */
return;
}
audit_log_format(ab, " res=%d", result);
audit_log_end(ab);
}
EXPORT_SYMBOL_GPL(dm_audit_log_ti);
void dm_audit_log_bio(const char *dm_msg_prefix, const char *op,
struct bio *bio, sector_t sector, int result)
{
struct audit_buffer *ab;
int dev_major = MAJOR(bio->bi_bdev->bd_dev);
int dev_minor = MINOR(bio->bi_bdev->bd_dev);
ab = dm_audit_log_start(AUDIT_DM_EVENT, dm_msg_prefix, op);
if (unlikely(!ab))
return;
audit_log_format(ab, " dev=%d:%d sector=%llu res=%d",
dev_major, dev_minor, sector, result);
audit_log_end(ab);
}
EXPORT_SYMBOL_GPL(dm_audit_log_bio);
| linux-master | drivers/md/dm-audit.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Partial Parity Log for closing the RAID5 write hole
* Copyright (c) 2017, Intel Corporation.
*/
#include <linux/kernel.h>
#include <linux/blkdev.h>
#include <linux/slab.h>
#include <linux/crc32c.h>
#include <linux/async_tx.h>
#include <linux/raid/md_p.h>
#include "md.h"
#include "raid5.h"
#include "raid5-log.h"
/*
* PPL consists of a 4KB header (struct ppl_header) and at least 128KB for
* partial parity data. The header contains an array of entries
* (struct ppl_header_entry) which describe the logged write requests.
* Partial parity for the entries comes after the header, written in the same
* sequence as the entries:
*
* Header
* entry0
* ...
* entryN
* PP data
* PP for entry0
* ...
* PP for entryN
*
* An entry describes one or more consecutive stripe_heads, up to a full
* stripe. The modifed raid data chunks form an m-by-n matrix, where m is the
* number of stripe_heads in the entry and n is the number of modified data
* disks. Every stripe_head in the entry must write to the same data disks.
* An example of a valid case described by a single entry (writes to the first
* stripe of a 4 disk array, 16k chunk size):
*
* sh->sector dd0 dd1 dd2 ppl
* +-----+-----+-----+
* 0 | --- | --- | --- | +----+
* 8 | -W- | -W- | --- | | pp | data_sector = 8
* 16 | -W- | -W- | --- | | pp | data_size = 3 * 2 * 4k
* 24 | -W- | -W- | --- | | pp | pp_size = 3 * 4k
* +-----+-----+-----+ +----+
*
* data_sector is the first raid sector of the modified data, data_size is the
* total size of modified data and pp_size is the size of partial parity for
* this entry. Entries for full stripe writes contain no partial parity
* (pp_size = 0), they only mark the stripes for which parity should be
* recalculated after an unclean shutdown. Every entry holds a checksum of its
* partial parity, the header also has a checksum of the header itself.
*
* A write request is always logged to the PPL instance stored on the parity
* disk of the corresponding stripe. For each member disk there is one ppl_log
* used to handle logging for this disk, independently from others. They are
* grouped in child_logs array in struct ppl_conf, which is assigned to
* r5conf->log_private.
*
* ppl_io_unit represents a full PPL write, header_page contains the ppl_header.
* PPL entries for logged stripes are added in ppl_log_stripe(). A stripe_head
* can be appended to the last entry if it meets the conditions for a valid
* entry described above, otherwise a new entry is added. Checksums of entries
* are calculated incrementally as stripes containing partial parity are being
* added. ppl_submit_iounit() calculates the checksum of the header and submits
* a bio containing the header page and partial parity pages (sh->ppl_page) for
* all stripes of the io_unit. When the PPL write completes, the stripes
* associated with the io_unit are released and raid5d starts writing their data
* and parity. When all stripes are written, the io_unit is freed and the next
* can be submitted.
*
* An io_unit is used to gather stripes until it is submitted or becomes full
* (if the maximum number of entries or size of PPL is reached). Another io_unit
* can't be submitted until the previous has completed (PPL and stripe
* data+parity is written). The log->io_list tracks all io_units of a log
* (for a single member disk). New io_units are added to the end of the list
* and the first io_unit is submitted, if it is not submitted already.
* The current io_unit accepting new stripes is always at the end of the list.
*
* If write-back cache is enabled for any of the disks in the array, its data
* must be flushed before next io_unit is submitted.
*/
#define PPL_SPACE_SIZE (128 * 1024)
struct ppl_conf {
struct mddev *mddev;
/* array of child logs, one for each raid disk */
struct ppl_log *child_logs;
int count;
int block_size; /* the logical block size used for data_sector
* in ppl_header_entry */
u32 signature; /* raid array identifier */
atomic64_t seq; /* current log write sequence number */
struct kmem_cache *io_kc;
mempool_t io_pool;
struct bio_set bs;
struct bio_set flush_bs;
/* used only for recovery */
int recovered_entries;
int mismatch_count;
/* stripes to retry if failed to allocate io_unit */
struct list_head no_mem_stripes;
spinlock_t no_mem_stripes_lock;
unsigned short write_hint;
};
struct ppl_log {
struct ppl_conf *ppl_conf; /* shared between all log instances */
struct md_rdev *rdev; /* array member disk associated with
* this log instance */
struct mutex io_mutex;
struct ppl_io_unit *current_io; /* current io_unit accepting new data
* always at the end of io_list */
spinlock_t io_list_lock;
struct list_head io_list; /* all io_units of this log */
sector_t next_io_sector;
unsigned int entry_space;
bool use_multippl;
bool wb_cache_on;
unsigned long disk_flush_bitmap;
};
#define PPL_IO_INLINE_BVECS 32
struct ppl_io_unit {
struct ppl_log *log;
struct page *header_page; /* for ppl_header */
unsigned int entries_count; /* number of entries in ppl_header */
unsigned int pp_size; /* total size current of partial parity */
u64 seq; /* sequence number of this log write */
struct list_head log_sibling; /* log->io_list */
struct list_head stripe_list; /* stripes added to the io_unit */
atomic_t pending_stripes; /* how many stripes not written to raid */
atomic_t pending_flushes; /* how many disk flushes are in progress */
bool submitted; /* true if write to log started */
/* inline bio and its biovec for submitting the iounit */
struct bio bio;
struct bio_vec biovec[PPL_IO_INLINE_BVECS];
};
struct dma_async_tx_descriptor *
ops_run_partial_parity(struct stripe_head *sh, struct raid5_percpu *percpu,
struct dma_async_tx_descriptor *tx)
{
int disks = sh->disks;
struct page **srcs = percpu->scribble;
int count = 0, pd_idx = sh->pd_idx, i;
struct async_submit_ctl submit;
pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector);
/*
* Partial parity is the XOR of stripe data chunks that are not changed
* during the write request. Depending on available data
* (read-modify-write vs. reconstruct-write case) we calculate it
* differently.
*/
if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
/*
* rmw: xor old data and parity from updated disks
* This is calculated earlier by ops_run_prexor5() so just copy
* the parity dev page.
*/
srcs[count++] = sh->dev[pd_idx].page;
} else if (sh->reconstruct_state == reconstruct_state_drain_run) {
/* rcw: xor data from all not updated disks */
for (i = disks; i--;) {
struct r5dev *dev = &sh->dev[i];
if (test_bit(R5_UPTODATE, &dev->flags))
srcs[count++] = dev->page;
}
} else {
return tx;
}
init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, tx,
NULL, sh, (void *) (srcs + sh->disks + 2));
if (count == 1)
tx = async_memcpy(sh->ppl_page, srcs[0], 0, 0, PAGE_SIZE,
&submit);
else
tx = async_xor(sh->ppl_page, srcs, 0, count, PAGE_SIZE,
&submit);
return tx;
}
static void *ppl_io_pool_alloc(gfp_t gfp_mask, void *pool_data)
{
struct kmem_cache *kc = pool_data;
struct ppl_io_unit *io;
io = kmem_cache_alloc(kc, gfp_mask);
if (!io)
return NULL;
io->header_page = alloc_page(gfp_mask);
if (!io->header_page) {
kmem_cache_free(kc, io);
return NULL;
}
return io;
}
static void ppl_io_pool_free(void *element, void *pool_data)
{
struct kmem_cache *kc = pool_data;
struct ppl_io_unit *io = element;
__free_page(io->header_page);
kmem_cache_free(kc, io);
}
static struct ppl_io_unit *ppl_new_iounit(struct ppl_log *log,
struct stripe_head *sh)
{
struct ppl_conf *ppl_conf = log->ppl_conf;
struct ppl_io_unit *io;
struct ppl_header *pplhdr;
struct page *header_page;
io = mempool_alloc(&ppl_conf->io_pool, GFP_NOWAIT);
if (!io)
return NULL;
header_page = io->header_page;
memset(io, 0, sizeof(*io));
io->header_page = header_page;
io->log = log;
INIT_LIST_HEAD(&io->log_sibling);
INIT_LIST_HEAD(&io->stripe_list);
atomic_set(&io->pending_stripes, 0);
atomic_set(&io->pending_flushes, 0);
bio_init(&io->bio, log->rdev->bdev, io->biovec, PPL_IO_INLINE_BVECS,
REQ_OP_WRITE | REQ_FUA);
pplhdr = page_address(io->header_page);
clear_page(pplhdr);
memset(pplhdr->reserved, 0xff, PPL_HDR_RESERVED);
pplhdr->signature = cpu_to_le32(ppl_conf->signature);
io->seq = atomic64_add_return(1, &ppl_conf->seq);
pplhdr->generation = cpu_to_le64(io->seq);
return io;
}
static int ppl_log_stripe(struct ppl_log *log, struct stripe_head *sh)
{
struct ppl_io_unit *io = log->current_io;
struct ppl_header_entry *e = NULL;
struct ppl_header *pplhdr;
int i;
sector_t data_sector = 0;
int data_disks = 0;
struct r5conf *conf = sh->raid_conf;
pr_debug("%s: stripe: %llu\n", __func__, (unsigned long long)sh->sector);
/* check if current io_unit is full */
if (io && (io->pp_size == log->entry_space ||
io->entries_count == PPL_HDR_MAX_ENTRIES)) {
pr_debug("%s: add io_unit blocked by seq: %llu\n",
__func__, io->seq);
io = NULL;
}
/* add a new unit if there is none or the current is full */
if (!io) {
io = ppl_new_iounit(log, sh);
if (!io)
return -ENOMEM;
spin_lock_irq(&log->io_list_lock);
list_add_tail(&io->log_sibling, &log->io_list);
spin_unlock_irq(&log->io_list_lock);
log->current_io = io;
}
for (i = 0; i < sh->disks; i++) {
struct r5dev *dev = &sh->dev[i];
if (i != sh->pd_idx && test_bit(R5_Wantwrite, &dev->flags)) {
if (!data_disks || dev->sector < data_sector)
data_sector = dev->sector;
data_disks++;
}
}
BUG_ON(!data_disks);
pr_debug("%s: seq: %llu data_sector: %llu data_disks: %d\n", __func__,
io->seq, (unsigned long long)data_sector, data_disks);
pplhdr = page_address(io->header_page);
if (io->entries_count > 0) {
struct ppl_header_entry *last =
&pplhdr->entries[io->entries_count - 1];
struct stripe_head *sh_last = list_last_entry(
&io->stripe_list, struct stripe_head, log_list);
u64 data_sector_last = le64_to_cpu(last->data_sector);
u32 data_size_last = le32_to_cpu(last->data_size);
/*
* Check if we can append the stripe to the last entry. It must
* be just after the last logged stripe and write to the same
* disks. Use bit shift and logarithm to avoid 64-bit division.
*/
if ((sh->sector == sh_last->sector + RAID5_STRIPE_SECTORS(conf)) &&
(data_sector >> ilog2(conf->chunk_sectors) ==
data_sector_last >> ilog2(conf->chunk_sectors)) &&
((data_sector - data_sector_last) * data_disks ==
data_size_last >> 9))
e = last;
}
if (!e) {
e = &pplhdr->entries[io->entries_count++];
e->data_sector = cpu_to_le64(data_sector);
e->parity_disk = cpu_to_le32(sh->pd_idx);
e->checksum = cpu_to_le32(~0);
}
le32_add_cpu(&e->data_size, data_disks << PAGE_SHIFT);
/* don't write any PP if full stripe write */
if (!test_bit(STRIPE_FULL_WRITE, &sh->state)) {
le32_add_cpu(&e->pp_size, PAGE_SIZE);
io->pp_size += PAGE_SIZE;
e->checksum = cpu_to_le32(crc32c_le(le32_to_cpu(e->checksum),
page_address(sh->ppl_page),
PAGE_SIZE));
}
list_add_tail(&sh->log_list, &io->stripe_list);
atomic_inc(&io->pending_stripes);
sh->ppl_io = io;
return 0;
}
int ppl_write_stripe(struct r5conf *conf, struct stripe_head *sh)
{
struct ppl_conf *ppl_conf = conf->log_private;
struct ppl_io_unit *io = sh->ppl_io;
struct ppl_log *log;
if (io || test_bit(STRIPE_SYNCING, &sh->state) || !sh->ppl_page ||
!test_bit(R5_Wantwrite, &sh->dev[sh->pd_idx].flags) ||
!test_bit(R5_Insync, &sh->dev[sh->pd_idx].flags)) {
clear_bit(STRIPE_LOG_TRAPPED, &sh->state);
return -EAGAIN;
}
log = &ppl_conf->child_logs[sh->pd_idx];
mutex_lock(&log->io_mutex);
if (!log->rdev || test_bit(Faulty, &log->rdev->flags)) {
mutex_unlock(&log->io_mutex);
return -EAGAIN;
}
set_bit(STRIPE_LOG_TRAPPED, &sh->state);
clear_bit(STRIPE_DELAYED, &sh->state);
atomic_inc(&sh->count);
if (ppl_log_stripe(log, sh)) {
spin_lock_irq(&ppl_conf->no_mem_stripes_lock);
list_add_tail(&sh->log_list, &ppl_conf->no_mem_stripes);
spin_unlock_irq(&ppl_conf->no_mem_stripes_lock);
}
mutex_unlock(&log->io_mutex);
return 0;
}
static void ppl_log_endio(struct bio *bio)
{
struct ppl_io_unit *io = bio->bi_private;
struct ppl_log *log = io->log;
struct ppl_conf *ppl_conf = log->ppl_conf;
struct stripe_head *sh, *next;
pr_debug("%s: seq: %llu\n", __func__, io->seq);
if (bio->bi_status)
md_error(ppl_conf->mddev, log->rdev);
list_for_each_entry_safe(sh, next, &io->stripe_list, log_list) {
list_del_init(&sh->log_list);
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
}
}
static void ppl_submit_iounit_bio(struct ppl_io_unit *io, struct bio *bio)
{
pr_debug("%s: seq: %llu size: %u sector: %llu dev: %pg\n",
__func__, io->seq, bio->bi_iter.bi_size,
(unsigned long long)bio->bi_iter.bi_sector,
bio->bi_bdev);
submit_bio(bio);
}
static void ppl_submit_iounit(struct ppl_io_unit *io)
{
struct ppl_log *log = io->log;
struct ppl_conf *ppl_conf = log->ppl_conf;
struct ppl_header *pplhdr = page_address(io->header_page);
struct bio *bio = &io->bio;
struct stripe_head *sh;
int i;
bio->bi_private = io;
if (!log->rdev || test_bit(Faulty, &log->rdev->flags)) {
ppl_log_endio(bio);
return;
}
for (i = 0; i < io->entries_count; i++) {
struct ppl_header_entry *e = &pplhdr->entries[i];
pr_debug("%s: seq: %llu entry: %d data_sector: %llu pp_size: %u data_size: %u\n",
__func__, io->seq, i, le64_to_cpu(e->data_sector),
le32_to_cpu(e->pp_size), le32_to_cpu(e->data_size));
e->data_sector = cpu_to_le64(le64_to_cpu(e->data_sector) >>
ilog2(ppl_conf->block_size >> 9));
e->checksum = cpu_to_le32(~le32_to_cpu(e->checksum));
}
pplhdr->entries_count = cpu_to_le32(io->entries_count);
pplhdr->checksum = cpu_to_le32(~crc32c_le(~0, pplhdr, PPL_HEADER_SIZE));
/* Rewind the buffer if current PPL is larger then remaining space */
if (log->use_multippl &&
log->rdev->ppl.sector + log->rdev->ppl.size - log->next_io_sector <
(PPL_HEADER_SIZE + io->pp_size) >> 9)
log->next_io_sector = log->rdev->ppl.sector;
bio->bi_end_io = ppl_log_endio;
bio->bi_iter.bi_sector = log->next_io_sector;
__bio_add_page(bio, io->header_page, PAGE_SIZE, 0);
pr_debug("%s: log->current_io_sector: %llu\n", __func__,
(unsigned long long)log->next_io_sector);
if (log->use_multippl)
log->next_io_sector += (PPL_HEADER_SIZE + io->pp_size) >> 9;
WARN_ON(log->disk_flush_bitmap != 0);
list_for_each_entry(sh, &io->stripe_list, log_list) {
for (i = 0; i < sh->disks; i++) {
struct r5dev *dev = &sh->dev[i];
if ((ppl_conf->child_logs[i].wb_cache_on) &&
(test_bit(R5_Wantwrite, &dev->flags))) {
set_bit(i, &log->disk_flush_bitmap);
}
}
/* entries for full stripe writes have no partial parity */
if (test_bit(STRIPE_FULL_WRITE, &sh->state))
continue;
if (!bio_add_page(bio, sh->ppl_page, PAGE_SIZE, 0)) {
struct bio *prev = bio;
bio = bio_alloc_bioset(prev->bi_bdev, BIO_MAX_VECS,
prev->bi_opf, GFP_NOIO,
&ppl_conf->bs);
bio->bi_iter.bi_sector = bio_end_sector(prev);
__bio_add_page(bio, sh->ppl_page, PAGE_SIZE, 0);
bio_chain(bio, prev);
ppl_submit_iounit_bio(io, prev);
}
}
ppl_submit_iounit_bio(io, bio);
}
static void ppl_submit_current_io(struct ppl_log *log)
{
struct ppl_io_unit *io;
spin_lock_irq(&log->io_list_lock);
io = list_first_entry_or_null(&log->io_list, struct ppl_io_unit,
log_sibling);
if (io && io->submitted)
io = NULL;
spin_unlock_irq(&log->io_list_lock);
if (io) {
io->submitted = true;
if (io == log->current_io)
log->current_io = NULL;
ppl_submit_iounit(io);
}
}
void ppl_write_stripe_run(struct r5conf *conf)
{
struct ppl_conf *ppl_conf = conf->log_private;
struct ppl_log *log;
int i;
for (i = 0; i < ppl_conf->count; i++) {
log = &ppl_conf->child_logs[i];
mutex_lock(&log->io_mutex);
ppl_submit_current_io(log);
mutex_unlock(&log->io_mutex);
}
}
static void ppl_io_unit_finished(struct ppl_io_unit *io)
{
struct ppl_log *log = io->log;
struct ppl_conf *ppl_conf = log->ppl_conf;
struct r5conf *conf = ppl_conf->mddev->private;
unsigned long flags;
pr_debug("%s: seq: %llu\n", __func__, io->seq);
local_irq_save(flags);
spin_lock(&log->io_list_lock);
list_del(&io->log_sibling);
spin_unlock(&log->io_list_lock);
mempool_free(io, &ppl_conf->io_pool);
spin_lock(&ppl_conf->no_mem_stripes_lock);
if (!list_empty(&ppl_conf->no_mem_stripes)) {
struct stripe_head *sh;
sh = list_first_entry(&ppl_conf->no_mem_stripes,
struct stripe_head, log_list);
list_del_init(&sh->log_list);
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
}
spin_unlock(&ppl_conf->no_mem_stripes_lock);
local_irq_restore(flags);
wake_up(&conf->wait_for_quiescent);
}
static void ppl_flush_endio(struct bio *bio)
{
struct ppl_io_unit *io = bio->bi_private;
struct ppl_log *log = io->log;
struct ppl_conf *ppl_conf = log->ppl_conf;
struct r5conf *conf = ppl_conf->mddev->private;
pr_debug("%s: dev: %pg\n", __func__, bio->bi_bdev);
if (bio->bi_status) {
struct md_rdev *rdev;
rcu_read_lock();
rdev = md_find_rdev_rcu(conf->mddev, bio_dev(bio));
if (rdev)
md_error(rdev->mddev, rdev);
rcu_read_unlock();
}
bio_put(bio);
if (atomic_dec_and_test(&io->pending_flushes)) {
ppl_io_unit_finished(io);
md_wakeup_thread(conf->mddev->thread);
}
}
static void ppl_do_flush(struct ppl_io_unit *io)
{
struct ppl_log *log = io->log;
struct ppl_conf *ppl_conf = log->ppl_conf;
struct r5conf *conf = ppl_conf->mddev->private;
int raid_disks = conf->raid_disks;
int flushed_disks = 0;
int i;
atomic_set(&io->pending_flushes, raid_disks);
for_each_set_bit(i, &log->disk_flush_bitmap, raid_disks) {
struct md_rdev *rdev;
struct block_device *bdev = NULL;
rcu_read_lock();
rdev = rcu_dereference(conf->disks[i].rdev);
if (rdev && !test_bit(Faulty, &rdev->flags))
bdev = rdev->bdev;
rcu_read_unlock();
if (bdev) {
struct bio *bio;
bio = bio_alloc_bioset(bdev, 0,
REQ_OP_WRITE | REQ_PREFLUSH,
GFP_NOIO, &ppl_conf->flush_bs);
bio->bi_private = io;
bio->bi_end_io = ppl_flush_endio;
pr_debug("%s: dev: %ps\n", __func__, bio->bi_bdev);
submit_bio(bio);
flushed_disks++;
}
}
log->disk_flush_bitmap = 0;
for (i = flushed_disks ; i < raid_disks; i++) {
if (atomic_dec_and_test(&io->pending_flushes))
ppl_io_unit_finished(io);
}
}
static inline bool ppl_no_io_unit_submitted(struct r5conf *conf,
struct ppl_log *log)
{
struct ppl_io_unit *io;
io = list_first_entry_or_null(&log->io_list, struct ppl_io_unit,
log_sibling);
return !io || !io->submitted;
}
void ppl_quiesce(struct r5conf *conf, int quiesce)
{
struct ppl_conf *ppl_conf = conf->log_private;
int i;
if (quiesce) {
for (i = 0; i < ppl_conf->count; i++) {
struct ppl_log *log = &ppl_conf->child_logs[i];
spin_lock_irq(&log->io_list_lock);
wait_event_lock_irq(conf->wait_for_quiescent,
ppl_no_io_unit_submitted(conf, log),
log->io_list_lock);
spin_unlock_irq(&log->io_list_lock);
}
}
}
int ppl_handle_flush_request(struct bio *bio)
{
if (bio->bi_iter.bi_size == 0) {
bio_endio(bio);
return 0;
}
bio->bi_opf &= ~REQ_PREFLUSH;
return -EAGAIN;
}
void ppl_stripe_write_finished(struct stripe_head *sh)
{
struct ppl_io_unit *io;
io = sh->ppl_io;
sh->ppl_io = NULL;
if (io && atomic_dec_and_test(&io->pending_stripes)) {
if (io->log->disk_flush_bitmap)
ppl_do_flush(io);
else
ppl_io_unit_finished(io);
}
}
static void ppl_xor(int size, struct page *page1, struct page *page2)
{
struct async_submit_ctl submit;
struct dma_async_tx_descriptor *tx;
struct page *xor_srcs[] = { page1, page2 };
init_async_submit(&submit, ASYNC_TX_ACK|ASYNC_TX_XOR_DROP_DST,
NULL, NULL, NULL, NULL);
tx = async_xor(page1, xor_srcs, 0, 2, size, &submit);
async_tx_quiesce(&tx);
}
/*
* PPL recovery strategy: xor partial parity and data from all modified data
* disks within a stripe and write the result as the new stripe parity. If all
* stripe data disks are modified (full stripe write), no partial parity is
* available, so just xor the data disks.
*
* Recovery of a PPL entry shall occur only if all modified data disks are
* available and read from all of them succeeds.
*
* A PPL entry applies to a stripe, partial parity size for an entry is at most
* the size of the chunk. Examples of possible cases for a single entry:
*
* case 0: single data disk write:
* data0 data1 data2 ppl parity
* +--------+--------+--------+ +--------------------+
* | ------ | ------ | ------ | +----+ | (no change) |
* | ------ | -data- | ------ | | pp | -> | data1 ^ pp |
* | ------ | -data- | ------ | | pp | -> | data1 ^ pp |
* | ------ | ------ | ------ | +----+ | (no change) |
* +--------+--------+--------+ +--------------------+
* pp_size = data_size
*
* case 1: more than one data disk write:
* data0 data1 data2 ppl parity
* +--------+--------+--------+ +--------------------+
* | ------ | ------ | ------ | +----+ | (no change) |
* | -data- | -data- | ------ | | pp | -> | data0 ^ data1 ^ pp |
* | -data- | -data- | ------ | | pp | -> | data0 ^ data1 ^ pp |
* | ------ | ------ | ------ | +----+ | (no change) |
* +--------+--------+--------+ +--------------------+
* pp_size = data_size / modified_data_disks
*
* case 2: write to all data disks (also full stripe write):
* data0 data1 data2 parity
* +--------+--------+--------+ +--------------------+
* | ------ | ------ | ------ | | (no change) |
* | -data- | -data- | -data- | --------> | xor all data |
* | ------ | ------ | ------ | --------> | (no change) |
* | ------ | ------ | ------ | | (no change) |
* +--------+--------+--------+ +--------------------+
* pp_size = 0
*
* The following cases are possible only in other implementations. The recovery
* code can handle them, but they are not generated at runtime because they can
* be reduced to cases 0, 1 and 2:
*
* case 3:
* data0 data1 data2 ppl parity
* +--------+--------+--------+ +----+ +--------------------+
* | ------ | -data- | -data- | | pp | | data1 ^ data2 ^ pp |
* | ------ | -data- | -data- | | pp | -> | data1 ^ data2 ^ pp |
* | -data- | -data- | -data- | | -- | -> | xor all data |
* | -data- | -data- | ------ | | pp | | data0 ^ data1 ^ pp |
* +--------+--------+--------+ +----+ +--------------------+
* pp_size = chunk_size
*
* case 4:
* data0 data1 data2 ppl parity
* +--------+--------+--------+ +----+ +--------------------+
* | ------ | -data- | ------ | | pp | | data1 ^ pp |
* | ------ | ------ | ------ | | -- | -> | (no change) |
* | ------ | ------ | ------ | | -- | -> | (no change) |
* | -data- | ------ | ------ | | pp | | data0 ^ pp |
* +--------+--------+--------+ +----+ +--------------------+
* pp_size = chunk_size
*/
static int ppl_recover_entry(struct ppl_log *log, struct ppl_header_entry *e,
sector_t ppl_sector)
{
struct ppl_conf *ppl_conf = log->ppl_conf;
struct mddev *mddev = ppl_conf->mddev;
struct r5conf *conf = mddev->private;
int block_size = ppl_conf->block_size;
struct page *page1;
struct page *page2;
sector_t r_sector_first;
sector_t r_sector_last;
int strip_sectors;
int data_disks;
int i;
int ret = 0;
unsigned int pp_size = le32_to_cpu(e->pp_size);
unsigned int data_size = le32_to_cpu(e->data_size);
page1 = alloc_page(GFP_KERNEL);
page2 = alloc_page(GFP_KERNEL);
if (!page1 || !page2) {
ret = -ENOMEM;
goto out;
}
r_sector_first = le64_to_cpu(e->data_sector) * (block_size >> 9);
if ((pp_size >> 9) < conf->chunk_sectors) {
if (pp_size > 0) {
data_disks = data_size / pp_size;
strip_sectors = pp_size >> 9;
} else {
data_disks = conf->raid_disks - conf->max_degraded;
strip_sectors = (data_size >> 9) / data_disks;
}
r_sector_last = r_sector_first +
(data_disks - 1) * conf->chunk_sectors +
strip_sectors;
} else {
data_disks = conf->raid_disks - conf->max_degraded;
strip_sectors = conf->chunk_sectors;
r_sector_last = r_sector_first + (data_size >> 9);
}
pr_debug("%s: array sector first: %llu last: %llu\n", __func__,
(unsigned long long)r_sector_first,
(unsigned long long)r_sector_last);
/* if start and end is 4k aligned, use a 4k block */
if (block_size == 512 &&
(r_sector_first & (RAID5_STRIPE_SECTORS(conf) - 1)) == 0 &&
(r_sector_last & (RAID5_STRIPE_SECTORS(conf) - 1)) == 0)
block_size = RAID5_STRIPE_SIZE(conf);
/* iterate through blocks in strip */
for (i = 0; i < strip_sectors; i += (block_size >> 9)) {
bool update_parity = false;
sector_t parity_sector;
struct md_rdev *parity_rdev;
struct stripe_head sh;
int disk;
int indent = 0;
pr_debug("%s:%*s iter %d start\n", __func__, indent, "", i);
indent += 2;
memset(page_address(page1), 0, PAGE_SIZE);
/* iterate through data member disks */
for (disk = 0; disk < data_disks; disk++) {
int dd_idx;
struct md_rdev *rdev;
sector_t sector;
sector_t r_sector = r_sector_first + i +
(disk * conf->chunk_sectors);
pr_debug("%s:%*s data member disk %d start\n",
__func__, indent, "", disk);
indent += 2;
if (r_sector >= r_sector_last) {
pr_debug("%s:%*s array sector %llu doesn't need parity update\n",
__func__, indent, "",
(unsigned long long)r_sector);
indent -= 2;
continue;
}
update_parity = true;
/* map raid sector to member disk */
sector = raid5_compute_sector(conf, r_sector, 0,
&dd_idx, NULL);
pr_debug("%s:%*s processing array sector %llu => data member disk %d, sector %llu\n",
__func__, indent, "",
(unsigned long long)r_sector, dd_idx,
(unsigned long long)sector);
/* Array has not started so rcu dereference is safe */
rdev = rcu_dereference_protected(
conf->disks[dd_idx].rdev, 1);
if (!rdev || (!test_bit(In_sync, &rdev->flags) &&
sector >= rdev->recovery_offset)) {
pr_debug("%s:%*s data member disk %d missing\n",
__func__, indent, "", dd_idx);
update_parity = false;
break;
}
pr_debug("%s:%*s reading data member disk %pg sector %llu\n",
__func__, indent, "", rdev->bdev,
(unsigned long long)sector);
if (!sync_page_io(rdev, sector, block_size, page2,
REQ_OP_READ, false)) {
md_error(mddev, rdev);
pr_debug("%s:%*s read failed!\n", __func__,
indent, "");
ret = -EIO;
goto out;
}
ppl_xor(block_size, page1, page2);
indent -= 2;
}
if (!update_parity)
continue;
if (pp_size > 0) {
pr_debug("%s:%*s reading pp disk sector %llu\n",
__func__, indent, "",
(unsigned long long)(ppl_sector + i));
if (!sync_page_io(log->rdev,
ppl_sector - log->rdev->data_offset + i,
block_size, page2, REQ_OP_READ,
false)) {
pr_debug("%s:%*s read failed!\n", __func__,
indent, "");
md_error(mddev, log->rdev);
ret = -EIO;
goto out;
}
ppl_xor(block_size, page1, page2);
}
/* map raid sector to parity disk */
parity_sector = raid5_compute_sector(conf, r_sector_first + i,
0, &disk, &sh);
BUG_ON(sh.pd_idx != le32_to_cpu(e->parity_disk));
/* Array has not started so rcu dereference is safe */
parity_rdev = rcu_dereference_protected(
conf->disks[sh.pd_idx].rdev, 1);
BUG_ON(parity_rdev->bdev->bd_dev != log->rdev->bdev->bd_dev);
pr_debug("%s:%*s write parity at sector %llu, disk %pg\n",
__func__, indent, "",
(unsigned long long)parity_sector,
parity_rdev->bdev);
if (!sync_page_io(parity_rdev, parity_sector, block_size,
page1, REQ_OP_WRITE, false)) {
pr_debug("%s:%*s parity write error!\n", __func__,
indent, "");
md_error(mddev, parity_rdev);
ret = -EIO;
goto out;
}
}
out:
if (page1)
__free_page(page1);
if (page2)
__free_page(page2);
return ret;
}
static int ppl_recover(struct ppl_log *log, struct ppl_header *pplhdr,
sector_t offset)
{
struct ppl_conf *ppl_conf = log->ppl_conf;
struct md_rdev *rdev = log->rdev;
struct mddev *mddev = rdev->mddev;
sector_t ppl_sector = rdev->ppl.sector + offset +
(PPL_HEADER_SIZE >> 9);
struct page *page;
int i;
int ret = 0;
page = alloc_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
/* iterate through all PPL entries saved */
for (i = 0; i < le32_to_cpu(pplhdr->entries_count); i++) {
struct ppl_header_entry *e = &pplhdr->entries[i];
u32 pp_size = le32_to_cpu(e->pp_size);
sector_t sector = ppl_sector;
int ppl_entry_sectors = pp_size >> 9;
u32 crc, crc_stored;
pr_debug("%s: disk: %d entry: %d ppl_sector: %llu pp_size: %u\n",
__func__, rdev->raid_disk, i,
(unsigned long long)ppl_sector, pp_size);
crc = ~0;
crc_stored = le32_to_cpu(e->checksum);
/* read parial parity for this entry and calculate its checksum */
while (pp_size) {
int s = pp_size > PAGE_SIZE ? PAGE_SIZE : pp_size;
if (!sync_page_io(rdev, sector - rdev->data_offset,
s, page, REQ_OP_READ, false)) {
md_error(mddev, rdev);
ret = -EIO;
goto out;
}
crc = crc32c_le(crc, page_address(page), s);
pp_size -= s;
sector += s >> 9;
}
crc = ~crc;
if (crc != crc_stored) {
/*
* Don't recover this entry if the checksum does not
* match, but keep going and try to recover other
* entries.
*/
pr_debug("%s: ppl entry crc does not match: stored: 0x%x calculated: 0x%x\n",
__func__, crc_stored, crc);
ppl_conf->mismatch_count++;
} else {
ret = ppl_recover_entry(log, e, ppl_sector);
if (ret)
goto out;
ppl_conf->recovered_entries++;
}
ppl_sector += ppl_entry_sectors;
}
/* flush the disk cache after recovery if necessary */
ret = blkdev_issue_flush(rdev->bdev);
out:
__free_page(page);
return ret;
}
static int ppl_write_empty_header(struct ppl_log *log)
{
struct page *page;
struct ppl_header *pplhdr;
struct md_rdev *rdev = log->rdev;
int ret = 0;
pr_debug("%s: disk: %d ppl_sector: %llu\n", __func__,
rdev->raid_disk, (unsigned long long)rdev->ppl.sector);
page = alloc_page(GFP_NOIO | __GFP_ZERO);
if (!page)
return -ENOMEM;
pplhdr = page_address(page);
/* zero out PPL space to avoid collision with old PPLs */
blkdev_issue_zeroout(rdev->bdev, rdev->ppl.sector,
log->rdev->ppl.size, GFP_NOIO, 0);
memset(pplhdr->reserved, 0xff, PPL_HDR_RESERVED);
pplhdr->signature = cpu_to_le32(log->ppl_conf->signature);
pplhdr->checksum = cpu_to_le32(~crc32c_le(~0, pplhdr, PAGE_SIZE));
if (!sync_page_io(rdev, rdev->ppl.sector - rdev->data_offset,
PPL_HEADER_SIZE, page, REQ_OP_WRITE | REQ_SYNC |
REQ_FUA, false)) {
md_error(rdev->mddev, rdev);
ret = -EIO;
}
__free_page(page);
return ret;
}
static int ppl_load_distributed(struct ppl_log *log)
{
struct ppl_conf *ppl_conf = log->ppl_conf;
struct md_rdev *rdev = log->rdev;
struct mddev *mddev = rdev->mddev;
struct page *page, *page2;
struct ppl_header *pplhdr = NULL, *prev_pplhdr = NULL;
u32 crc, crc_stored;
u32 signature;
int ret = 0, i;
sector_t pplhdr_offset = 0, prev_pplhdr_offset = 0;
pr_debug("%s: disk: %d\n", __func__, rdev->raid_disk);
/* read PPL headers, find the recent one */
page = alloc_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
page2 = alloc_page(GFP_KERNEL);
if (!page2) {
__free_page(page);
return -ENOMEM;
}
/* searching ppl area for latest ppl */
while (pplhdr_offset < rdev->ppl.size - (PPL_HEADER_SIZE >> 9)) {
if (!sync_page_io(rdev,
rdev->ppl.sector - rdev->data_offset +
pplhdr_offset, PAGE_SIZE, page, REQ_OP_READ,
false)) {
md_error(mddev, rdev);
ret = -EIO;
/* if not able to read - don't recover any PPL */
pplhdr = NULL;
break;
}
pplhdr = page_address(page);
/* check header validity */
crc_stored = le32_to_cpu(pplhdr->checksum);
pplhdr->checksum = 0;
crc = ~crc32c_le(~0, pplhdr, PAGE_SIZE);
if (crc_stored != crc) {
pr_debug("%s: ppl header crc does not match: stored: 0x%x calculated: 0x%x (offset: %llu)\n",
__func__, crc_stored, crc,
(unsigned long long)pplhdr_offset);
pplhdr = prev_pplhdr;
pplhdr_offset = prev_pplhdr_offset;
break;
}
signature = le32_to_cpu(pplhdr->signature);
if (mddev->external) {
/*
* For external metadata the header signature is set and
* validated in userspace.
*/
ppl_conf->signature = signature;
} else if (ppl_conf->signature != signature) {
pr_debug("%s: ppl header signature does not match: stored: 0x%x configured: 0x%x (offset: %llu)\n",
__func__, signature, ppl_conf->signature,
(unsigned long long)pplhdr_offset);
pplhdr = prev_pplhdr;
pplhdr_offset = prev_pplhdr_offset;
break;
}
if (prev_pplhdr && le64_to_cpu(prev_pplhdr->generation) >
le64_to_cpu(pplhdr->generation)) {
/* previous was newest */
pplhdr = prev_pplhdr;
pplhdr_offset = prev_pplhdr_offset;
break;
}
prev_pplhdr_offset = pplhdr_offset;
prev_pplhdr = pplhdr;
swap(page, page2);
/* calculate next potential ppl offset */
for (i = 0; i < le32_to_cpu(pplhdr->entries_count); i++)
pplhdr_offset +=
le32_to_cpu(pplhdr->entries[i].pp_size) >> 9;
pplhdr_offset += PPL_HEADER_SIZE >> 9;
}
/* no valid ppl found */
if (!pplhdr)
ppl_conf->mismatch_count++;
else
pr_debug("%s: latest PPL found at offset: %llu, with generation: %llu\n",
__func__, (unsigned long long)pplhdr_offset,
le64_to_cpu(pplhdr->generation));
/* attempt to recover from log if we are starting a dirty array */
if (pplhdr && !mddev->pers && mddev->recovery_cp != MaxSector)
ret = ppl_recover(log, pplhdr, pplhdr_offset);
/* write empty header if we are starting the array */
if (!ret && !mddev->pers)
ret = ppl_write_empty_header(log);
__free_page(page);
__free_page(page2);
pr_debug("%s: return: %d mismatch_count: %d recovered_entries: %d\n",
__func__, ret, ppl_conf->mismatch_count,
ppl_conf->recovered_entries);
return ret;
}
static int ppl_load(struct ppl_conf *ppl_conf)
{
int ret = 0;
u32 signature = 0;
bool signature_set = false;
int i;
for (i = 0; i < ppl_conf->count; i++) {
struct ppl_log *log = &ppl_conf->child_logs[i];
/* skip missing drive */
if (!log->rdev)
continue;
ret = ppl_load_distributed(log);
if (ret)
break;
/*
* For external metadata we can't check if the signature is
* correct on a single drive, but we can check if it is the same
* on all drives.
*/
if (ppl_conf->mddev->external) {
if (!signature_set) {
signature = ppl_conf->signature;
signature_set = true;
} else if (signature != ppl_conf->signature) {
pr_warn("md/raid:%s: PPL header signature does not match on all member drives\n",
mdname(ppl_conf->mddev));
ret = -EINVAL;
break;
}
}
}
pr_debug("%s: return: %d mismatch_count: %d recovered_entries: %d\n",
__func__, ret, ppl_conf->mismatch_count,
ppl_conf->recovered_entries);
return ret;
}
static void __ppl_exit_log(struct ppl_conf *ppl_conf)
{
clear_bit(MD_HAS_PPL, &ppl_conf->mddev->flags);
clear_bit(MD_HAS_MULTIPLE_PPLS, &ppl_conf->mddev->flags);
kfree(ppl_conf->child_logs);
bioset_exit(&ppl_conf->bs);
bioset_exit(&ppl_conf->flush_bs);
mempool_exit(&ppl_conf->io_pool);
kmem_cache_destroy(ppl_conf->io_kc);
kfree(ppl_conf);
}
void ppl_exit_log(struct r5conf *conf)
{
struct ppl_conf *ppl_conf = conf->log_private;
if (ppl_conf) {
__ppl_exit_log(ppl_conf);
conf->log_private = NULL;
}
}
static int ppl_validate_rdev(struct md_rdev *rdev)
{
int ppl_data_sectors;
int ppl_size_new;
/*
* The configured PPL size must be enough to store
* the header and (at the very least) partial parity
* for one stripe. Round it down to ensure the data
* space is cleanly divisible by stripe size.
*/
ppl_data_sectors = rdev->ppl.size - (PPL_HEADER_SIZE >> 9);
if (ppl_data_sectors > 0)
ppl_data_sectors = rounddown(ppl_data_sectors,
RAID5_STRIPE_SECTORS((struct r5conf *)rdev->mddev->private));
if (ppl_data_sectors <= 0) {
pr_warn("md/raid:%s: PPL space too small on %pg\n",
mdname(rdev->mddev), rdev->bdev);
return -ENOSPC;
}
ppl_size_new = ppl_data_sectors + (PPL_HEADER_SIZE >> 9);
if ((rdev->ppl.sector < rdev->data_offset &&
rdev->ppl.sector + ppl_size_new > rdev->data_offset) ||
(rdev->ppl.sector >= rdev->data_offset &&
rdev->data_offset + rdev->sectors > rdev->ppl.sector)) {
pr_warn("md/raid:%s: PPL space overlaps with data on %pg\n",
mdname(rdev->mddev), rdev->bdev);
return -EINVAL;
}
if (!rdev->mddev->external &&
((rdev->ppl.offset > 0 && rdev->ppl.offset < (rdev->sb_size >> 9)) ||
(rdev->ppl.offset <= 0 && rdev->ppl.offset + ppl_size_new > 0))) {
pr_warn("md/raid:%s: PPL space overlaps with superblock on %pg\n",
mdname(rdev->mddev), rdev->bdev);
return -EINVAL;
}
rdev->ppl.size = ppl_size_new;
return 0;
}
static void ppl_init_child_log(struct ppl_log *log, struct md_rdev *rdev)
{
if ((rdev->ppl.size << 9) >= (PPL_SPACE_SIZE +
PPL_HEADER_SIZE) * 2) {
log->use_multippl = true;
set_bit(MD_HAS_MULTIPLE_PPLS,
&log->ppl_conf->mddev->flags);
log->entry_space = PPL_SPACE_SIZE;
} else {
log->use_multippl = false;
log->entry_space = (log->rdev->ppl.size << 9) -
PPL_HEADER_SIZE;
}
log->next_io_sector = rdev->ppl.sector;
if (bdev_write_cache(rdev->bdev))
log->wb_cache_on = true;
}
int ppl_init_log(struct r5conf *conf)
{
struct ppl_conf *ppl_conf;
struct mddev *mddev = conf->mddev;
int ret = 0;
int max_disks;
int i;
pr_debug("md/raid:%s: enabling distributed Partial Parity Log\n",
mdname(conf->mddev));
if (PAGE_SIZE != 4096)
return -EINVAL;
if (mddev->level != 5) {
pr_warn("md/raid:%s PPL is not compatible with raid level %d\n",
mdname(mddev), mddev->level);
return -EINVAL;
}
if (mddev->bitmap_info.file || mddev->bitmap_info.offset) {
pr_warn("md/raid:%s PPL is not compatible with bitmap\n",
mdname(mddev));
return -EINVAL;
}
if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) {
pr_warn("md/raid:%s PPL is not compatible with journal\n",
mdname(mddev));
return -EINVAL;
}
max_disks = sizeof_field(struct ppl_log, disk_flush_bitmap) *
BITS_PER_BYTE;
if (conf->raid_disks > max_disks) {
pr_warn("md/raid:%s PPL doesn't support over %d disks in the array\n",
mdname(mddev), max_disks);
return -EINVAL;
}
ppl_conf = kzalloc(sizeof(struct ppl_conf), GFP_KERNEL);
if (!ppl_conf)
return -ENOMEM;
ppl_conf->mddev = mddev;
ppl_conf->io_kc = KMEM_CACHE(ppl_io_unit, 0);
if (!ppl_conf->io_kc) {
ret = -ENOMEM;
goto err;
}
ret = mempool_init(&ppl_conf->io_pool, conf->raid_disks, ppl_io_pool_alloc,
ppl_io_pool_free, ppl_conf->io_kc);
if (ret)
goto err;
ret = bioset_init(&ppl_conf->bs, conf->raid_disks, 0, BIOSET_NEED_BVECS);
if (ret)
goto err;
ret = bioset_init(&ppl_conf->flush_bs, conf->raid_disks, 0, 0);
if (ret)
goto err;
ppl_conf->count = conf->raid_disks;
ppl_conf->child_logs = kcalloc(ppl_conf->count, sizeof(struct ppl_log),
GFP_KERNEL);
if (!ppl_conf->child_logs) {
ret = -ENOMEM;
goto err;
}
atomic64_set(&ppl_conf->seq, 0);
INIT_LIST_HEAD(&ppl_conf->no_mem_stripes);
spin_lock_init(&ppl_conf->no_mem_stripes_lock);
if (!mddev->external) {
ppl_conf->signature = ~crc32c_le(~0, mddev->uuid, sizeof(mddev->uuid));
ppl_conf->block_size = 512;
} else {
ppl_conf->block_size = queue_logical_block_size(mddev->queue);
}
for (i = 0; i < ppl_conf->count; i++) {
struct ppl_log *log = &ppl_conf->child_logs[i];
/* Array has not started so rcu dereference is safe */
struct md_rdev *rdev =
rcu_dereference_protected(conf->disks[i].rdev, 1);
mutex_init(&log->io_mutex);
spin_lock_init(&log->io_list_lock);
INIT_LIST_HEAD(&log->io_list);
log->ppl_conf = ppl_conf;
log->rdev = rdev;
if (rdev) {
ret = ppl_validate_rdev(rdev);
if (ret)
goto err;
ppl_init_child_log(log, rdev);
}
}
/* load and possibly recover the logs from the member disks */
ret = ppl_load(ppl_conf);
if (ret) {
goto err;
} else if (!mddev->pers && mddev->recovery_cp == 0 &&
ppl_conf->recovered_entries > 0 &&
ppl_conf->mismatch_count == 0) {
/*
* If we are starting a dirty array and the recovery succeeds
* without any issues, set the array as clean.
*/
mddev->recovery_cp = MaxSector;
set_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
} else if (mddev->pers && ppl_conf->mismatch_count > 0) {
/* no mismatch allowed when enabling PPL for a running array */
ret = -EINVAL;
goto err;
}
conf->log_private = ppl_conf;
set_bit(MD_HAS_PPL, &ppl_conf->mddev->flags);
return 0;
err:
__ppl_exit_log(ppl_conf);
return ret;
}
int ppl_modify_log(struct r5conf *conf, struct md_rdev *rdev, bool add)
{
struct ppl_conf *ppl_conf = conf->log_private;
struct ppl_log *log;
int ret = 0;
if (!rdev)
return -EINVAL;
pr_debug("%s: disk: %d operation: %s dev: %pg\n",
__func__, rdev->raid_disk, add ? "add" : "remove",
rdev->bdev);
if (rdev->raid_disk < 0)
return 0;
if (rdev->raid_disk >= ppl_conf->count)
return -ENODEV;
log = &ppl_conf->child_logs[rdev->raid_disk];
mutex_lock(&log->io_mutex);
if (add) {
ret = ppl_validate_rdev(rdev);
if (!ret) {
log->rdev = rdev;
ret = ppl_write_empty_header(log);
ppl_init_child_log(log, rdev);
}
} else {
log->rdev = NULL;
}
mutex_unlock(&log->io_mutex);
return ret;
}
static ssize_t
ppl_write_hint_show(struct mddev *mddev, char *buf)
{
return sprintf(buf, "%d\n", 0);
}
static ssize_t
ppl_write_hint_store(struct mddev *mddev, const char *page, size_t len)
{
struct r5conf *conf;
int err = 0;
unsigned short new;
if (len >= PAGE_SIZE)
return -EINVAL;
if (kstrtou16(page, 10, &new))
return -EINVAL;
err = mddev_lock(mddev);
if (err)
return err;
conf = mddev->private;
if (!conf)
err = -ENODEV;
else if (!raid5_has_ppl(conf) || !conf->log_private)
err = -EINVAL;
mddev_unlock(mddev);
return err ?: len;
}
struct md_sysfs_entry
ppl_write_hint = __ATTR(ppl_write_hint, S_IRUGO | S_IWUSR,
ppl_write_hint_show,
ppl_write_hint_store);
| linux-master | drivers/md/raid5-ppl.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* bitmap.c two-level bitmap (C) Peter T. Breuer ([email protected]) 2003
*
* bitmap_create - sets up the bitmap structure
* bitmap_destroy - destroys the bitmap structure
*
* additions, Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.:
* - added disk storage for bitmap
* - changes to allow various bitmap chunk sizes
*/
/*
* Still to do:
*
* flush after percent set rather than just time based. (maybe both).
*/
#include <linux/blkdev.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/sched.h>
#include <linux/list.h>
#include <linux/file.h>
#include <linux/mount.h>
#include <linux/buffer_head.h>
#include <linux/seq_file.h>
#include <trace/events/block.h>
#include "md.h"
#include "md-bitmap.h"
static inline char *bmname(struct bitmap *bitmap)
{
return bitmap->mddev ? mdname(bitmap->mddev) : "mdX";
}
/*
* check a page and, if necessary, allocate it (or hijack it if the alloc fails)
*
* 1) check to see if this page is allocated, if it's not then try to alloc
* 2) if the alloc fails, set the page's hijacked flag so we'll use the
* page pointer directly as a counter
*
* if we find our page, we increment the page's refcount so that it stays
* allocated while we're using it
*/
static int md_bitmap_checkpage(struct bitmap_counts *bitmap,
unsigned long page, int create, int no_hijack)
__releases(bitmap->lock)
__acquires(bitmap->lock)
{
unsigned char *mappage;
WARN_ON_ONCE(page >= bitmap->pages);
if (bitmap->bp[page].hijacked) /* it's hijacked, don't try to alloc */
return 0;
if (bitmap->bp[page].map) /* page is already allocated, just return */
return 0;
if (!create)
return -ENOENT;
/* this page has not been allocated yet */
spin_unlock_irq(&bitmap->lock);
/* It is possible that this is being called inside a
* prepare_to_wait/finish_wait loop from raid5c:make_request().
* In general it is not permitted to sleep in that context as it
* can cause the loop to spin freely.
* That doesn't apply here as we can only reach this point
* once with any loop.
* When this function completes, either bp[page].map or
* bp[page].hijacked. In either case, this function will
* abort before getting to this point again. So there is
* no risk of a free-spin, and so it is safe to assert
* that sleeping here is allowed.
*/
sched_annotate_sleep();
mappage = kzalloc(PAGE_SIZE, GFP_NOIO);
spin_lock_irq(&bitmap->lock);
if (mappage == NULL) {
pr_debug("md/bitmap: map page allocation failed, hijacking\n");
/* We don't support hijack for cluster raid */
if (no_hijack)
return -ENOMEM;
/* failed - set the hijacked flag so that we can use the
* pointer as a counter */
if (!bitmap->bp[page].map)
bitmap->bp[page].hijacked = 1;
} else if (bitmap->bp[page].map ||
bitmap->bp[page].hijacked) {
/* somebody beat us to getting the page */
kfree(mappage);
} else {
/* no page was in place and we have one, so install it */
bitmap->bp[page].map = mappage;
bitmap->missing_pages--;
}
return 0;
}
/* if page is completely empty, put it back on the free list, or dealloc it */
/* if page was hijacked, unmark the flag so it might get alloced next time */
/* Note: lock should be held when calling this */
static void md_bitmap_checkfree(struct bitmap_counts *bitmap, unsigned long page)
{
char *ptr;
if (bitmap->bp[page].count) /* page is still busy */
return;
/* page is no longer in use, it can be released */
if (bitmap->bp[page].hijacked) { /* page was hijacked, undo this now */
bitmap->bp[page].hijacked = 0;
bitmap->bp[page].map = NULL;
} else {
/* normal case, free the page */
ptr = bitmap->bp[page].map;
bitmap->bp[page].map = NULL;
bitmap->missing_pages++;
kfree(ptr);
}
}
/*
* bitmap file handling - read and write the bitmap file and its superblock
*/
/*
* basic page I/O operations
*/
/* IO operations when bitmap is stored near all superblocks */
/* choose a good rdev and read the page from there */
static int read_sb_page(struct mddev *mddev, loff_t offset,
struct page *page, unsigned long index, int size)
{
sector_t sector = mddev->bitmap_info.offset + offset +
index * (PAGE_SIZE / SECTOR_SIZE);
struct md_rdev *rdev;
rdev_for_each(rdev, mddev) {
u32 iosize = roundup(size, bdev_logical_block_size(rdev->bdev));
if (!test_bit(In_sync, &rdev->flags) ||
test_bit(Faulty, &rdev->flags) ||
test_bit(Bitmap_sync, &rdev->flags))
continue;
if (sync_page_io(rdev, sector, iosize, page, REQ_OP_READ, true))
return 0;
}
return -EIO;
}
static struct md_rdev *next_active_rdev(struct md_rdev *rdev, struct mddev *mddev)
{
/* Iterate the disks of an mddev, using rcu to protect access to the
* linked list, and raising the refcount of devices we return to ensure
* they don't disappear while in use.
* As devices are only added or removed when raid_disk is < 0 and
* nr_pending is 0 and In_sync is clear, the entries we return will
* still be in the same position on the list when we re-enter
* list_for_each_entry_continue_rcu.
*
* Note that if entered with 'rdev == NULL' to start at the
* beginning, we temporarily assign 'rdev' to an address which
* isn't really an rdev, but which can be used by
* list_for_each_entry_continue_rcu() to find the first entry.
*/
rcu_read_lock();
if (rdev == NULL)
/* start at the beginning */
rdev = list_entry(&mddev->disks, struct md_rdev, same_set);
else {
/* release the previous rdev and start from there. */
rdev_dec_pending(rdev, mddev);
}
list_for_each_entry_continue_rcu(rdev, &mddev->disks, same_set) {
if (rdev->raid_disk >= 0 &&
!test_bit(Faulty, &rdev->flags)) {
/* this is a usable devices */
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
return rdev;
}
}
rcu_read_unlock();
return NULL;
}
static unsigned int optimal_io_size(struct block_device *bdev,
unsigned int last_page_size,
unsigned int io_size)
{
if (bdev_io_opt(bdev) > bdev_logical_block_size(bdev))
return roundup(last_page_size, bdev_io_opt(bdev));
return io_size;
}
static unsigned int bitmap_io_size(unsigned int io_size, unsigned int opt_size,
loff_t start, loff_t boundary)
{
if (io_size != opt_size &&
start + opt_size / SECTOR_SIZE <= boundary)
return opt_size;
if (start + io_size / SECTOR_SIZE <= boundary)
return io_size;
/* Overflows boundary */
return 0;
}
static int __write_sb_page(struct md_rdev *rdev, struct bitmap *bitmap,
unsigned long pg_index, struct page *page)
{
struct block_device *bdev;
struct mddev *mddev = bitmap->mddev;
struct bitmap_storage *store = &bitmap->storage;
loff_t sboff, offset = mddev->bitmap_info.offset;
sector_t ps = pg_index * PAGE_SIZE / SECTOR_SIZE;
unsigned int size = PAGE_SIZE;
unsigned int opt_size = PAGE_SIZE;
sector_t doff;
bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;
if (pg_index == store->file_pages - 1) {
unsigned int last_page_size = store->bytes & (PAGE_SIZE - 1);
if (last_page_size == 0)
last_page_size = PAGE_SIZE;
size = roundup(last_page_size, bdev_logical_block_size(bdev));
opt_size = optimal_io_size(bdev, last_page_size, size);
}
sboff = rdev->sb_start + offset;
doff = rdev->data_offset;
/* Just make sure we aren't corrupting data or metadata */
if (mddev->external) {
/* Bitmap could be anywhere. */
if (sboff + ps > doff &&
sboff < (doff + mddev->dev_sectors + PAGE_SIZE / SECTOR_SIZE))
return -EINVAL;
} else if (offset < 0) {
/* DATA BITMAP METADATA */
size = bitmap_io_size(size, opt_size, offset + ps, 0);
if (size == 0)
/* bitmap runs in to metadata */
return -EINVAL;
if (doff + mddev->dev_sectors > sboff)
/* data runs in to bitmap */
return -EINVAL;
} else if (rdev->sb_start < rdev->data_offset) {
/* METADATA BITMAP DATA */
size = bitmap_io_size(size, opt_size, sboff + ps, doff);
if (size == 0)
/* bitmap runs in to data */
return -EINVAL;
} else {
/* DATA METADATA BITMAP - no problems */
}
md_super_write(mddev, rdev, sboff + ps, (int) size, page);
return 0;
}
static void write_sb_page(struct bitmap *bitmap, unsigned long pg_index,
struct page *page, bool wait)
{
struct mddev *mddev = bitmap->mddev;
do {
struct md_rdev *rdev = NULL;
while ((rdev = next_active_rdev(rdev, mddev)) != NULL) {
if (__write_sb_page(rdev, bitmap, pg_index, page) < 0) {
set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
return;
}
}
} while (wait && md_super_wait(mddev) < 0);
}
static void md_bitmap_file_kick(struct bitmap *bitmap);
#ifdef CONFIG_MD_BITMAP_FILE
static void write_file_page(struct bitmap *bitmap, struct page *page, int wait)
{
struct buffer_head *bh = page_buffers(page);
while (bh && bh->b_blocknr) {
atomic_inc(&bitmap->pending_writes);
set_buffer_locked(bh);
set_buffer_mapped(bh);
submit_bh(REQ_OP_WRITE | REQ_SYNC, bh);
bh = bh->b_this_page;
}
if (wait)
wait_event(bitmap->write_wait,
atomic_read(&bitmap->pending_writes) == 0);
}
static void end_bitmap_write(struct buffer_head *bh, int uptodate)
{
struct bitmap *bitmap = bh->b_private;
if (!uptodate)
set_bit(BITMAP_WRITE_ERROR, &bitmap->flags);
if (atomic_dec_and_test(&bitmap->pending_writes))
wake_up(&bitmap->write_wait);
}
static void free_buffers(struct page *page)
{
struct buffer_head *bh;
if (!PagePrivate(page))
return;
bh = page_buffers(page);
while (bh) {
struct buffer_head *next = bh->b_this_page;
free_buffer_head(bh);
bh = next;
}
detach_page_private(page);
put_page(page);
}
/* read a page from a file.
* We both read the page, and attach buffers to the page to record the
* address of each block (using bmap). These addresses will be used
* to write the block later, completely bypassing the filesystem.
* This usage is similar to how swap files are handled, and allows us
* to write to a file with no concerns of memory allocation failing.
*/
static int read_file_page(struct file *file, unsigned long index,
struct bitmap *bitmap, unsigned long count, struct page *page)
{
int ret = 0;
struct inode *inode = file_inode(file);
struct buffer_head *bh;
sector_t block, blk_cur;
unsigned long blocksize = i_blocksize(inode);
pr_debug("read bitmap file (%dB @ %llu)\n", (int)PAGE_SIZE,
(unsigned long long)index << PAGE_SHIFT);
bh = alloc_page_buffers(page, blocksize, false);
if (!bh) {
ret = -ENOMEM;
goto out;
}
attach_page_private(page, bh);
blk_cur = index << (PAGE_SHIFT - inode->i_blkbits);
while (bh) {
block = blk_cur;
if (count == 0)
bh->b_blocknr = 0;
else {
ret = bmap(inode, &block);
if (ret || !block) {
ret = -EINVAL;
bh->b_blocknr = 0;
goto out;
}
bh->b_blocknr = block;
bh->b_bdev = inode->i_sb->s_bdev;
if (count < blocksize)
count = 0;
else
count -= blocksize;
bh->b_end_io = end_bitmap_write;
bh->b_private = bitmap;
atomic_inc(&bitmap->pending_writes);
set_buffer_locked(bh);
set_buffer_mapped(bh);
submit_bh(REQ_OP_READ, bh);
}
blk_cur++;
bh = bh->b_this_page;
}
wait_event(bitmap->write_wait,
atomic_read(&bitmap->pending_writes)==0);
if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
ret = -EIO;
out:
if (ret)
pr_err("md: bitmap read error: (%dB @ %llu): %d\n",
(int)PAGE_SIZE,
(unsigned long long)index << PAGE_SHIFT,
ret);
return ret;
}
#else /* CONFIG_MD_BITMAP_FILE */
static void write_file_page(struct bitmap *bitmap, struct page *page, int wait)
{
}
static int read_file_page(struct file *file, unsigned long index,
struct bitmap *bitmap, unsigned long count, struct page *page)
{
return -EIO;
}
static void free_buffers(struct page *page)
{
put_page(page);
}
#endif /* CONFIG_MD_BITMAP_FILE */
/*
* bitmap file superblock operations
*/
/*
* write out a page to a file
*/
static void filemap_write_page(struct bitmap *bitmap, unsigned long pg_index,
bool wait)
{
struct bitmap_storage *store = &bitmap->storage;
struct page *page = store->filemap[pg_index];
if (mddev_is_clustered(bitmap->mddev)) {
pg_index += bitmap->cluster_slot *
DIV_ROUND_UP(store->bytes, PAGE_SIZE);
}
if (store->file)
write_file_page(bitmap, page, wait);
else
write_sb_page(bitmap, pg_index, page, wait);
}
/*
* md_bitmap_wait_writes() should be called before writing any bitmap
* blocks, to ensure previous writes, particularly from
* md_bitmap_daemon_work(), have completed.
*/
static void md_bitmap_wait_writes(struct bitmap *bitmap)
{
if (bitmap->storage.file)
wait_event(bitmap->write_wait,
atomic_read(&bitmap->pending_writes)==0);
else
/* Note that we ignore the return value. The writes
* might have failed, but that would just mean that
* some bits which should be cleared haven't been,
* which is safe. The relevant bitmap blocks will
* probably get written again, but there is no great
* loss if they aren't.
*/
md_super_wait(bitmap->mddev);
}
/* update the event counter and sync the superblock to disk */
void md_bitmap_update_sb(struct bitmap *bitmap)
{
bitmap_super_t *sb;
if (!bitmap || !bitmap->mddev) /* no bitmap for this array */
return;
if (bitmap->mddev->bitmap_info.external)
return;
if (!bitmap->storage.sb_page) /* no superblock */
return;
sb = kmap_atomic(bitmap->storage.sb_page);
sb->events = cpu_to_le64(bitmap->mddev->events);
if (bitmap->mddev->events < bitmap->events_cleared)
/* rocking back to read-only */
bitmap->events_cleared = bitmap->mddev->events;
sb->events_cleared = cpu_to_le64(bitmap->events_cleared);
/*
* clear BITMAP_WRITE_ERROR bit to protect against the case that
* a bitmap write error occurred but the later writes succeeded.
*/
sb->state = cpu_to_le32(bitmap->flags & ~BIT(BITMAP_WRITE_ERROR));
/* Just in case these have been changed via sysfs: */
sb->daemon_sleep = cpu_to_le32(bitmap->mddev->bitmap_info.daemon_sleep/HZ);
sb->write_behind = cpu_to_le32(bitmap->mddev->bitmap_info.max_write_behind);
/* This might have been changed by a reshape */
sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
sb->chunksize = cpu_to_le32(bitmap->mddev->bitmap_info.chunksize);
sb->nodes = cpu_to_le32(bitmap->mddev->bitmap_info.nodes);
sb->sectors_reserved = cpu_to_le32(bitmap->mddev->
bitmap_info.space);
kunmap_atomic(sb);
if (bitmap->storage.file)
write_file_page(bitmap, bitmap->storage.sb_page, 1);
else
write_sb_page(bitmap, bitmap->storage.sb_index,
bitmap->storage.sb_page, 1);
}
EXPORT_SYMBOL(md_bitmap_update_sb);
/* print out the bitmap file superblock */
void md_bitmap_print_sb(struct bitmap *bitmap)
{
bitmap_super_t *sb;
if (!bitmap || !bitmap->storage.sb_page)
return;
sb = kmap_atomic(bitmap->storage.sb_page);
pr_debug("%s: bitmap file superblock:\n", bmname(bitmap));
pr_debug(" magic: %08x\n", le32_to_cpu(sb->magic));
pr_debug(" version: %u\n", le32_to_cpu(sb->version));
pr_debug(" uuid: %08x.%08x.%08x.%08x\n",
le32_to_cpu(*(__le32 *)(sb->uuid+0)),
le32_to_cpu(*(__le32 *)(sb->uuid+4)),
le32_to_cpu(*(__le32 *)(sb->uuid+8)),
le32_to_cpu(*(__le32 *)(sb->uuid+12)));
pr_debug(" events: %llu\n",
(unsigned long long) le64_to_cpu(sb->events));
pr_debug("events cleared: %llu\n",
(unsigned long long) le64_to_cpu(sb->events_cleared));
pr_debug(" state: %08x\n", le32_to_cpu(sb->state));
pr_debug(" chunksize: %u B\n", le32_to_cpu(sb->chunksize));
pr_debug(" daemon sleep: %us\n", le32_to_cpu(sb->daemon_sleep));
pr_debug(" sync size: %llu KB\n",
(unsigned long long)le64_to_cpu(sb->sync_size)/2);
pr_debug("max write behind: %u\n", le32_to_cpu(sb->write_behind));
kunmap_atomic(sb);
}
/*
* bitmap_new_disk_sb
* @bitmap
*
* This function is somewhat the reverse of bitmap_read_sb. bitmap_read_sb
* reads and verifies the on-disk bitmap superblock and populates bitmap_info.
* This function verifies 'bitmap_info' and populates the on-disk bitmap
* structure, which is to be written to disk.
*
* Returns: 0 on success, -Exxx on error
*/
static int md_bitmap_new_disk_sb(struct bitmap *bitmap)
{
bitmap_super_t *sb;
unsigned long chunksize, daemon_sleep, write_behind;
bitmap->storage.sb_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
if (bitmap->storage.sb_page == NULL)
return -ENOMEM;
bitmap->storage.sb_index = 0;
sb = kmap_atomic(bitmap->storage.sb_page);
sb->magic = cpu_to_le32(BITMAP_MAGIC);
sb->version = cpu_to_le32(BITMAP_MAJOR_HI);
chunksize = bitmap->mddev->bitmap_info.chunksize;
BUG_ON(!chunksize);
if (!is_power_of_2(chunksize)) {
kunmap_atomic(sb);
pr_warn("bitmap chunksize not a power of 2\n");
return -EINVAL;
}
sb->chunksize = cpu_to_le32(chunksize);
daemon_sleep = bitmap->mddev->bitmap_info.daemon_sleep;
if (!daemon_sleep || (daemon_sleep > MAX_SCHEDULE_TIMEOUT)) {
pr_debug("Choosing daemon_sleep default (5 sec)\n");
daemon_sleep = 5 * HZ;
}
sb->daemon_sleep = cpu_to_le32(daemon_sleep);
bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
/*
* FIXME: write_behind for RAID1. If not specified, what
* is a good choice? We choose COUNTER_MAX / 2 arbitrarily.
*/
write_behind = bitmap->mddev->bitmap_info.max_write_behind;
if (write_behind > COUNTER_MAX)
write_behind = COUNTER_MAX / 2;
sb->write_behind = cpu_to_le32(write_behind);
bitmap->mddev->bitmap_info.max_write_behind = write_behind;
/* keep the array size field of the bitmap superblock up to date */
sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
memcpy(sb->uuid, bitmap->mddev->uuid, 16);
set_bit(BITMAP_STALE, &bitmap->flags);
sb->state = cpu_to_le32(bitmap->flags);
bitmap->events_cleared = bitmap->mddev->events;
sb->events_cleared = cpu_to_le64(bitmap->mddev->events);
bitmap->mddev->bitmap_info.nodes = 0;
kunmap_atomic(sb);
return 0;
}
/* read the superblock from the bitmap file and initialize some bitmap fields */
static int md_bitmap_read_sb(struct bitmap *bitmap)
{
char *reason = NULL;
bitmap_super_t *sb;
unsigned long chunksize, daemon_sleep, write_behind;
unsigned long long events;
int nodes = 0;
unsigned long sectors_reserved = 0;
int err = -EINVAL;
struct page *sb_page;
loff_t offset = 0;
if (!bitmap->storage.file && !bitmap->mddev->bitmap_info.offset) {
chunksize = 128 * 1024 * 1024;
daemon_sleep = 5 * HZ;
write_behind = 0;
set_bit(BITMAP_STALE, &bitmap->flags);
err = 0;
goto out_no_sb;
}
/* page 0 is the superblock, read it... */
sb_page = alloc_page(GFP_KERNEL);
if (!sb_page)
return -ENOMEM;
bitmap->storage.sb_page = sb_page;
re_read:
/* If cluster_slot is set, the cluster is setup */
if (bitmap->cluster_slot >= 0) {
sector_t bm_blocks = bitmap->mddev->resync_max_sectors;
bm_blocks = DIV_ROUND_UP_SECTOR_T(bm_blocks,
(bitmap->mddev->bitmap_info.chunksize >> 9));
/* bits to bytes */
bm_blocks = ((bm_blocks+7) >> 3) + sizeof(bitmap_super_t);
/* to 4k blocks */
bm_blocks = DIV_ROUND_UP_SECTOR_T(bm_blocks, 4096);
offset = bitmap->cluster_slot * (bm_blocks << 3);
pr_debug("%s:%d bm slot: %d offset: %llu\n", __func__, __LINE__,
bitmap->cluster_slot, offset);
}
if (bitmap->storage.file) {
loff_t isize = i_size_read(bitmap->storage.file->f_mapping->host);
int bytes = isize > PAGE_SIZE ? PAGE_SIZE : isize;
err = read_file_page(bitmap->storage.file, 0,
bitmap, bytes, sb_page);
} else {
err = read_sb_page(bitmap->mddev, offset, sb_page, 0,
sizeof(bitmap_super_t));
}
if (err)
return err;
err = -EINVAL;
sb = kmap_atomic(sb_page);
chunksize = le32_to_cpu(sb->chunksize);
daemon_sleep = le32_to_cpu(sb->daemon_sleep) * HZ;
write_behind = le32_to_cpu(sb->write_behind);
sectors_reserved = le32_to_cpu(sb->sectors_reserved);
/* verify that the bitmap-specific fields are valid */
if (sb->magic != cpu_to_le32(BITMAP_MAGIC))
reason = "bad magic";
else if (le32_to_cpu(sb->version) < BITMAP_MAJOR_LO ||
le32_to_cpu(sb->version) > BITMAP_MAJOR_CLUSTERED)
reason = "unrecognized superblock version";
else if (chunksize < 512)
reason = "bitmap chunksize too small";
else if (!is_power_of_2(chunksize))
reason = "bitmap chunksize not a power of 2";
else if (daemon_sleep < 1 || daemon_sleep > MAX_SCHEDULE_TIMEOUT)
reason = "daemon sleep period out of range";
else if (write_behind > COUNTER_MAX)
reason = "write-behind limit out of range (0 - 16383)";
if (reason) {
pr_warn("%s: invalid bitmap file superblock: %s\n",
bmname(bitmap), reason);
goto out;
}
/*
* Setup nodes/clustername only if bitmap version is
* cluster-compatible
*/
if (sb->version == cpu_to_le32(BITMAP_MAJOR_CLUSTERED)) {
nodes = le32_to_cpu(sb->nodes);
strscpy(bitmap->mddev->bitmap_info.cluster_name,
sb->cluster_name, 64);
}
/* keep the array size field of the bitmap superblock up to date */
sb->sync_size = cpu_to_le64(bitmap->mddev->resync_max_sectors);
if (bitmap->mddev->persistent) {
/*
* We have a persistent array superblock, so compare the
* bitmap's UUID and event counter to the mddev's
*/
if (memcmp(sb->uuid, bitmap->mddev->uuid, 16)) {
pr_warn("%s: bitmap superblock UUID mismatch\n",
bmname(bitmap));
goto out;
}
events = le64_to_cpu(sb->events);
if (!nodes && (events < bitmap->mddev->events)) {
pr_warn("%s: bitmap file is out of date (%llu < %llu) -- forcing full recovery\n",
bmname(bitmap), events,
(unsigned long long) bitmap->mddev->events);
set_bit(BITMAP_STALE, &bitmap->flags);
}
}
/* assign fields using values from superblock */
bitmap->flags |= le32_to_cpu(sb->state);
if (le32_to_cpu(sb->version) == BITMAP_MAJOR_HOSTENDIAN)
set_bit(BITMAP_HOSTENDIAN, &bitmap->flags);
bitmap->events_cleared = le64_to_cpu(sb->events_cleared);
err = 0;
out:
kunmap_atomic(sb);
if (err == 0 && nodes && (bitmap->cluster_slot < 0)) {
/* Assigning chunksize is required for "re_read" */
bitmap->mddev->bitmap_info.chunksize = chunksize;
err = md_setup_cluster(bitmap->mddev, nodes);
if (err) {
pr_warn("%s: Could not setup cluster service (%d)\n",
bmname(bitmap), err);
goto out_no_sb;
}
bitmap->cluster_slot = md_cluster_ops->slot_number(bitmap->mddev);
goto re_read;
}
out_no_sb:
if (err == 0) {
if (test_bit(BITMAP_STALE, &bitmap->flags))
bitmap->events_cleared = bitmap->mddev->events;
bitmap->mddev->bitmap_info.chunksize = chunksize;
bitmap->mddev->bitmap_info.daemon_sleep = daemon_sleep;
bitmap->mddev->bitmap_info.max_write_behind = write_behind;
bitmap->mddev->bitmap_info.nodes = nodes;
if (bitmap->mddev->bitmap_info.space == 0 ||
bitmap->mddev->bitmap_info.space > sectors_reserved)
bitmap->mddev->bitmap_info.space = sectors_reserved;
} else {
md_bitmap_print_sb(bitmap);
if (bitmap->cluster_slot < 0)
md_cluster_stop(bitmap->mddev);
}
return err;
}
/*
* general bitmap file operations
*/
/*
* on-disk bitmap:
*
* Use one bit per "chunk" (block set). We do the disk I/O on the bitmap
* file a page at a time. There's a superblock at the start of the file.
*/
/* calculate the index of the page that contains this bit */
static inline unsigned long file_page_index(struct bitmap_storage *store,
unsigned long chunk)
{
if (store->sb_page)
chunk += sizeof(bitmap_super_t) << 3;
return chunk >> PAGE_BIT_SHIFT;
}
/* calculate the (bit) offset of this bit within a page */
static inline unsigned long file_page_offset(struct bitmap_storage *store,
unsigned long chunk)
{
if (store->sb_page)
chunk += sizeof(bitmap_super_t) << 3;
return chunk & (PAGE_BITS - 1);
}
/*
* return a pointer to the page in the filemap that contains the given bit
*
*/
static inline struct page *filemap_get_page(struct bitmap_storage *store,
unsigned long chunk)
{
if (file_page_index(store, chunk) >= store->file_pages)
return NULL;
return store->filemap[file_page_index(store, chunk)];
}
static int md_bitmap_storage_alloc(struct bitmap_storage *store,
unsigned long chunks, int with_super,
int slot_number)
{
int pnum, offset = 0;
unsigned long num_pages;
unsigned long bytes;
bytes = DIV_ROUND_UP(chunks, 8);
if (with_super)
bytes += sizeof(bitmap_super_t);
num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);
offset = slot_number * num_pages;
store->filemap = kmalloc_array(num_pages, sizeof(struct page *),
GFP_KERNEL);
if (!store->filemap)
return -ENOMEM;
if (with_super && !store->sb_page) {
store->sb_page = alloc_page(GFP_KERNEL|__GFP_ZERO);
if (store->sb_page == NULL)
return -ENOMEM;
}
pnum = 0;
if (store->sb_page) {
store->filemap[0] = store->sb_page;
pnum = 1;
store->sb_index = offset;
}
for ( ; pnum < num_pages; pnum++) {
store->filemap[pnum] = alloc_page(GFP_KERNEL|__GFP_ZERO);
if (!store->filemap[pnum]) {
store->file_pages = pnum;
return -ENOMEM;
}
}
store->file_pages = pnum;
/* We need 4 bits per page, rounded up to a multiple
* of sizeof(unsigned long) */
store->filemap_attr = kzalloc(
roundup(DIV_ROUND_UP(num_pages*4, 8), sizeof(unsigned long)),
GFP_KERNEL);
if (!store->filemap_attr)
return -ENOMEM;
store->bytes = bytes;
return 0;
}
static void md_bitmap_file_unmap(struct bitmap_storage *store)
{
struct file *file = store->file;
struct page *sb_page = store->sb_page;
struct page **map = store->filemap;
int pages = store->file_pages;
while (pages--)
if (map[pages] != sb_page) /* 0 is sb_page, release it below */
free_buffers(map[pages]);
kfree(map);
kfree(store->filemap_attr);
if (sb_page)
free_buffers(sb_page);
if (file) {
struct inode *inode = file_inode(file);
invalidate_mapping_pages(inode->i_mapping, 0, -1);
fput(file);
}
}
/*
* bitmap_file_kick - if an error occurs while manipulating the bitmap file
* then it is no longer reliable, so we stop using it and we mark the file
* as failed in the superblock
*/
static void md_bitmap_file_kick(struct bitmap *bitmap)
{
if (!test_and_set_bit(BITMAP_STALE, &bitmap->flags)) {
md_bitmap_update_sb(bitmap);
if (bitmap->storage.file) {
pr_warn("%s: kicking failed bitmap file %pD4 from array!\n",
bmname(bitmap), bitmap->storage.file);
} else
pr_warn("%s: disabling internal bitmap due to errors\n",
bmname(bitmap));
}
}
enum bitmap_page_attr {
BITMAP_PAGE_DIRTY = 0, /* there are set bits that need to be synced */
BITMAP_PAGE_PENDING = 1, /* there are bits that are being cleaned.
* i.e. counter is 1 or 2. */
BITMAP_PAGE_NEEDWRITE = 2, /* there are cleared bits that need to be synced */
};
static inline void set_page_attr(struct bitmap *bitmap, int pnum,
enum bitmap_page_attr attr)
{
set_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
}
static inline void clear_page_attr(struct bitmap *bitmap, int pnum,
enum bitmap_page_attr attr)
{
clear_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
}
static inline int test_page_attr(struct bitmap *bitmap, int pnum,
enum bitmap_page_attr attr)
{
return test_bit((pnum<<2) + attr, bitmap->storage.filemap_attr);
}
static inline int test_and_clear_page_attr(struct bitmap *bitmap, int pnum,
enum bitmap_page_attr attr)
{
return test_and_clear_bit((pnum<<2) + attr,
bitmap->storage.filemap_attr);
}
/*
* bitmap_file_set_bit -- called before performing a write to the md device
* to set (and eventually sync) a particular bit in the bitmap file
*
* we set the bit immediately, then we record the page number so that
* when an unplug occurs, we can flush the dirty pages out to disk
*/
static void md_bitmap_file_set_bit(struct bitmap *bitmap, sector_t block)
{
unsigned long bit;
struct page *page;
void *kaddr;
unsigned long chunk = block >> bitmap->counts.chunkshift;
struct bitmap_storage *store = &bitmap->storage;
unsigned long index = file_page_index(store, chunk);
unsigned long node_offset = 0;
if (mddev_is_clustered(bitmap->mddev))
node_offset = bitmap->cluster_slot * store->file_pages;
page = filemap_get_page(&bitmap->storage, chunk);
if (!page)
return;
bit = file_page_offset(&bitmap->storage, chunk);
/* set the bit */
kaddr = kmap_atomic(page);
if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
set_bit(bit, kaddr);
else
set_bit_le(bit, kaddr);
kunmap_atomic(kaddr);
pr_debug("set file bit %lu page %lu\n", bit, index);
/* record page number so it gets flushed to disk when unplug occurs */
set_page_attr(bitmap, index - node_offset, BITMAP_PAGE_DIRTY);
}
static void md_bitmap_file_clear_bit(struct bitmap *bitmap, sector_t block)
{
unsigned long bit;
struct page *page;
void *paddr;
unsigned long chunk = block >> bitmap->counts.chunkshift;
struct bitmap_storage *store = &bitmap->storage;
unsigned long index = file_page_index(store, chunk);
unsigned long node_offset = 0;
if (mddev_is_clustered(bitmap->mddev))
node_offset = bitmap->cluster_slot * store->file_pages;
page = filemap_get_page(&bitmap->storage, chunk);
if (!page)
return;
bit = file_page_offset(&bitmap->storage, chunk);
paddr = kmap_atomic(page);
if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
clear_bit(bit, paddr);
else
clear_bit_le(bit, paddr);
kunmap_atomic(paddr);
if (!test_page_attr(bitmap, index - node_offset, BITMAP_PAGE_NEEDWRITE)) {
set_page_attr(bitmap, index - node_offset, BITMAP_PAGE_PENDING);
bitmap->allclean = 0;
}
}
static int md_bitmap_file_test_bit(struct bitmap *bitmap, sector_t block)
{
unsigned long bit;
struct page *page;
void *paddr;
unsigned long chunk = block >> bitmap->counts.chunkshift;
int set = 0;
page = filemap_get_page(&bitmap->storage, chunk);
if (!page)
return -EINVAL;
bit = file_page_offset(&bitmap->storage, chunk);
paddr = kmap_atomic(page);
if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
set = test_bit(bit, paddr);
else
set = test_bit_le(bit, paddr);
kunmap_atomic(paddr);
return set;
}
/* this gets called when the md device is ready to unplug its underlying
* (slave) device queues -- before we let any writes go down, we need to
* sync the dirty pages of the bitmap file to disk */
void md_bitmap_unplug(struct bitmap *bitmap)
{
unsigned long i;
int dirty, need_write;
int writing = 0;
if (!md_bitmap_enabled(bitmap))
return;
/* look at each page to see if there are any set bits that need to be
* flushed out to disk */
for (i = 0; i < bitmap->storage.file_pages; i++) {
dirty = test_and_clear_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
need_write = test_and_clear_page_attr(bitmap, i,
BITMAP_PAGE_NEEDWRITE);
if (dirty || need_write) {
if (!writing) {
md_bitmap_wait_writes(bitmap);
if (bitmap->mddev->queue)
blk_add_trace_msg(bitmap->mddev->queue,
"md bitmap_unplug");
}
clear_page_attr(bitmap, i, BITMAP_PAGE_PENDING);
filemap_write_page(bitmap, i, false);
writing = 1;
}
}
if (writing)
md_bitmap_wait_writes(bitmap);
if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
md_bitmap_file_kick(bitmap);
}
EXPORT_SYMBOL(md_bitmap_unplug);
struct bitmap_unplug_work {
struct work_struct work;
struct bitmap *bitmap;
struct completion *done;
};
static void md_bitmap_unplug_fn(struct work_struct *work)
{
struct bitmap_unplug_work *unplug_work =
container_of(work, struct bitmap_unplug_work, work);
md_bitmap_unplug(unplug_work->bitmap);
complete(unplug_work->done);
}
void md_bitmap_unplug_async(struct bitmap *bitmap)
{
DECLARE_COMPLETION_ONSTACK(done);
struct bitmap_unplug_work unplug_work;
INIT_WORK_ONSTACK(&unplug_work.work, md_bitmap_unplug_fn);
unplug_work.bitmap = bitmap;
unplug_work.done = &done;
queue_work(md_bitmap_wq, &unplug_work.work);
wait_for_completion(&done);
}
EXPORT_SYMBOL(md_bitmap_unplug_async);
static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed);
/*
* Initialize the in-memory bitmap from the on-disk bitmap and set up the memory
* mapping of the bitmap file.
*
* Special case: If there's no bitmap file, or if the bitmap file had been
* previously kicked from the array, we mark all the bits as 1's in order to
* cause a full resync.
*
* We ignore all bits for sectors that end earlier than 'start'.
* This is used when reading an out-of-date bitmap.
*/
static int md_bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
{
bool outofdate = test_bit(BITMAP_STALE, &bitmap->flags);
struct mddev *mddev = bitmap->mddev;
unsigned long chunks = bitmap->counts.chunks;
struct bitmap_storage *store = &bitmap->storage;
struct file *file = store->file;
unsigned long node_offset = 0;
unsigned long bit_cnt = 0;
unsigned long i;
int ret;
if (!file && !mddev->bitmap_info.offset) {
/* No permanent bitmap - fill with '1s'. */
store->filemap = NULL;
store->file_pages = 0;
for (i = 0; i < chunks ; i++) {
/* if the disk bit is set, set the memory bit */
int needed = ((sector_t)(i+1) << (bitmap->counts.chunkshift)
>= start);
md_bitmap_set_memory_bits(bitmap,
(sector_t)i << bitmap->counts.chunkshift,
needed);
}
return 0;
}
if (file && i_size_read(file->f_mapping->host) < store->bytes) {
pr_warn("%s: bitmap file too short %lu < %lu\n",
bmname(bitmap),
(unsigned long) i_size_read(file->f_mapping->host),
store->bytes);
ret = -ENOSPC;
goto err;
}
if (mddev_is_clustered(mddev))
node_offset = bitmap->cluster_slot * (DIV_ROUND_UP(store->bytes, PAGE_SIZE));
for (i = 0; i < store->file_pages; i++) {
struct page *page = store->filemap[i];
int count;
/* unmap the old page, we're done with it */
if (i == store->file_pages - 1)
count = store->bytes - i * PAGE_SIZE;
else
count = PAGE_SIZE;
if (file)
ret = read_file_page(file, i, bitmap, count, page);
else
ret = read_sb_page(mddev, 0, page, i + node_offset,
count);
if (ret)
goto err;
}
if (outofdate) {
pr_warn("%s: bitmap file is out of date, doing full recovery\n",
bmname(bitmap));
for (i = 0; i < store->file_pages; i++) {
struct page *page = store->filemap[i];
unsigned long offset = 0;
void *paddr;
if (i == 0 && !mddev->bitmap_info.external)
offset = sizeof(bitmap_super_t);
/*
* If the bitmap is out of date, dirty the whole page
* and write it out
*/
paddr = kmap_atomic(page);
memset(paddr + offset, 0xff, PAGE_SIZE - offset);
kunmap_atomic(paddr);
filemap_write_page(bitmap, i, true);
if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags)) {
ret = -EIO;
goto err;
}
}
}
for (i = 0; i < chunks; i++) {
struct page *page = filemap_get_page(&bitmap->storage, i);
unsigned long bit = file_page_offset(&bitmap->storage, i);
void *paddr;
bool was_set;
paddr = kmap_atomic(page);
if (test_bit(BITMAP_HOSTENDIAN, &bitmap->flags))
was_set = test_bit(bit, paddr);
else
was_set = test_bit_le(bit, paddr);
kunmap_atomic(paddr);
if (was_set) {
/* if the disk bit is set, set the memory bit */
int needed = ((sector_t)(i+1) << bitmap->counts.chunkshift
>= start);
md_bitmap_set_memory_bits(bitmap,
(sector_t)i << bitmap->counts.chunkshift,
needed);
bit_cnt++;
}
}
pr_debug("%s: bitmap initialized from disk: read %lu pages, set %lu of %lu bits\n",
bmname(bitmap), store->file_pages,
bit_cnt, chunks);
return 0;
err:
pr_warn("%s: bitmap initialisation failed: %d\n",
bmname(bitmap), ret);
return ret;
}
void md_bitmap_write_all(struct bitmap *bitmap)
{
/* We don't actually write all bitmap blocks here,
* just flag them as needing to be written
*/
int i;
if (!bitmap || !bitmap->storage.filemap)
return;
if (bitmap->storage.file)
/* Only one copy, so nothing needed */
return;
for (i = 0; i < bitmap->storage.file_pages; i++)
set_page_attr(bitmap, i,
BITMAP_PAGE_NEEDWRITE);
bitmap->allclean = 0;
}
static void md_bitmap_count_page(struct bitmap_counts *bitmap,
sector_t offset, int inc)
{
sector_t chunk = offset >> bitmap->chunkshift;
unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
bitmap->bp[page].count += inc;
md_bitmap_checkfree(bitmap, page);
}
static void md_bitmap_set_pending(struct bitmap_counts *bitmap, sector_t offset)
{
sector_t chunk = offset >> bitmap->chunkshift;
unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
struct bitmap_page *bp = &bitmap->bp[page];
if (!bp->pending)
bp->pending = 1;
}
static bitmap_counter_t *md_bitmap_get_counter(struct bitmap_counts *bitmap,
sector_t offset, sector_t *blocks,
int create);
static void mddev_set_timeout(struct mddev *mddev, unsigned long timeout,
bool force)
{
struct md_thread *thread;
rcu_read_lock();
thread = rcu_dereference(mddev->thread);
if (!thread)
goto out;
if (force || thread->timeout < MAX_SCHEDULE_TIMEOUT)
thread->timeout = timeout;
out:
rcu_read_unlock();
}
/*
* bitmap daemon -- periodically wakes up to clean bits and flush pages
* out to disk
*/
void md_bitmap_daemon_work(struct mddev *mddev)
{
struct bitmap *bitmap;
unsigned long j;
unsigned long nextpage;
sector_t blocks;
struct bitmap_counts *counts;
/* Use a mutex to guard daemon_work against
* bitmap_destroy.
*/
mutex_lock(&mddev->bitmap_info.mutex);
bitmap = mddev->bitmap;
if (bitmap == NULL) {
mutex_unlock(&mddev->bitmap_info.mutex);
return;
}
if (time_before(jiffies, bitmap->daemon_lastrun
+ mddev->bitmap_info.daemon_sleep))
goto done;
bitmap->daemon_lastrun = jiffies;
if (bitmap->allclean) {
mddev_set_timeout(mddev, MAX_SCHEDULE_TIMEOUT, true);
goto done;
}
bitmap->allclean = 1;
if (bitmap->mddev->queue)
blk_add_trace_msg(bitmap->mddev->queue,
"md bitmap_daemon_work");
/* Any file-page which is PENDING now needs to be written.
* So set NEEDWRITE now, then after we make any last-minute changes
* we will write it.
*/
for (j = 0; j < bitmap->storage.file_pages; j++)
if (test_and_clear_page_attr(bitmap, j,
BITMAP_PAGE_PENDING))
set_page_attr(bitmap, j,
BITMAP_PAGE_NEEDWRITE);
if (bitmap->need_sync &&
mddev->bitmap_info.external == 0) {
/* Arrange for superblock update as well as
* other changes */
bitmap_super_t *sb;
bitmap->need_sync = 0;
if (bitmap->storage.filemap) {
sb = kmap_atomic(bitmap->storage.sb_page);
sb->events_cleared =
cpu_to_le64(bitmap->events_cleared);
kunmap_atomic(sb);
set_page_attr(bitmap, 0,
BITMAP_PAGE_NEEDWRITE);
}
}
/* Now look at the bitmap counters and if any are '2' or '1',
* decrement and handle accordingly.
*/
counts = &bitmap->counts;
spin_lock_irq(&counts->lock);
nextpage = 0;
for (j = 0; j < counts->chunks; j++) {
bitmap_counter_t *bmc;
sector_t block = (sector_t)j << counts->chunkshift;
if (j == nextpage) {
nextpage += PAGE_COUNTER_RATIO;
if (!counts->bp[j >> PAGE_COUNTER_SHIFT].pending) {
j |= PAGE_COUNTER_MASK;
continue;
}
counts->bp[j >> PAGE_COUNTER_SHIFT].pending = 0;
}
bmc = md_bitmap_get_counter(counts, block, &blocks, 0);
if (!bmc) {
j |= PAGE_COUNTER_MASK;
continue;
}
if (*bmc == 1 && !bitmap->need_sync) {
/* We can clear the bit */
*bmc = 0;
md_bitmap_count_page(counts, block, -1);
md_bitmap_file_clear_bit(bitmap, block);
} else if (*bmc && *bmc <= 2) {
*bmc = 1;
md_bitmap_set_pending(counts, block);
bitmap->allclean = 0;
}
}
spin_unlock_irq(&counts->lock);
md_bitmap_wait_writes(bitmap);
/* Now start writeout on any page in NEEDWRITE that isn't DIRTY.
* DIRTY pages need to be written by bitmap_unplug so it can wait
* for them.
* If we find any DIRTY page we stop there and let bitmap_unplug
* handle all the rest. This is important in the case where
* the first blocking holds the superblock and it has been updated.
* We mustn't write any other blocks before the superblock.
*/
for (j = 0;
j < bitmap->storage.file_pages
&& !test_bit(BITMAP_STALE, &bitmap->flags);
j++) {
if (test_page_attr(bitmap, j,
BITMAP_PAGE_DIRTY))
/* bitmap_unplug will handle the rest */
break;
if (bitmap->storage.filemap &&
test_and_clear_page_attr(bitmap, j,
BITMAP_PAGE_NEEDWRITE))
filemap_write_page(bitmap, j, false);
}
done:
if (bitmap->allclean == 0)
mddev_set_timeout(mddev, mddev->bitmap_info.daemon_sleep, true);
mutex_unlock(&mddev->bitmap_info.mutex);
}
static bitmap_counter_t *md_bitmap_get_counter(struct bitmap_counts *bitmap,
sector_t offset, sector_t *blocks,
int create)
__releases(bitmap->lock)
__acquires(bitmap->lock)
{
/* If 'create', we might release the lock and reclaim it.
* The lock must have been taken with interrupts enabled.
* If !create, we don't release the lock.
*/
sector_t chunk = offset >> bitmap->chunkshift;
unsigned long page = chunk >> PAGE_COUNTER_SHIFT;
unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT;
sector_t csize;
int err;
if (page >= bitmap->pages) {
/*
* This can happen if bitmap_start_sync goes beyond
* End-of-device while looking for a whole page or
* user set a huge number to sysfs bitmap_set_bits.
*/
return NULL;
}
err = md_bitmap_checkpage(bitmap, page, create, 0);
if (bitmap->bp[page].hijacked ||
bitmap->bp[page].map == NULL)
csize = ((sector_t)1) << (bitmap->chunkshift +
PAGE_COUNTER_SHIFT);
else
csize = ((sector_t)1) << bitmap->chunkshift;
*blocks = csize - (offset & (csize - 1));
if (err < 0)
return NULL;
/* now locked ... */
if (bitmap->bp[page].hijacked) { /* hijacked pointer */
/* should we use the first or second counter field
* of the hijacked pointer? */
int hi = (pageoff > PAGE_COUNTER_MASK);
return &((bitmap_counter_t *)
&bitmap->bp[page].map)[hi];
} else /* page is allocated */
return (bitmap_counter_t *)
&(bitmap->bp[page].map[pageoff]);
}
int md_bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind)
{
if (!bitmap)
return 0;
if (behind) {
int bw;
atomic_inc(&bitmap->behind_writes);
bw = atomic_read(&bitmap->behind_writes);
if (bw > bitmap->behind_writes_used)
bitmap->behind_writes_used = bw;
pr_debug("inc write-behind count %d/%lu\n",
bw, bitmap->mddev->bitmap_info.max_write_behind);
}
while (sectors) {
sector_t blocks;
bitmap_counter_t *bmc;
spin_lock_irq(&bitmap->counts.lock);
bmc = md_bitmap_get_counter(&bitmap->counts, offset, &blocks, 1);
if (!bmc) {
spin_unlock_irq(&bitmap->counts.lock);
return 0;
}
if (unlikely(COUNTER(*bmc) == COUNTER_MAX)) {
DEFINE_WAIT(__wait);
/* note that it is safe to do the prepare_to_wait
* after the test as long as we do it before dropping
* the spinlock.
*/
prepare_to_wait(&bitmap->overflow_wait, &__wait,
TASK_UNINTERRUPTIBLE);
spin_unlock_irq(&bitmap->counts.lock);
schedule();
finish_wait(&bitmap->overflow_wait, &__wait);
continue;
}
switch (*bmc) {
case 0:
md_bitmap_file_set_bit(bitmap, offset);
md_bitmap_count_page(&bitmap->counts, offset, 1);
fallthrough;
case 1:
*bmc = 2;
}
(*bmc)++;
spin_unlock_irq(&bitmap->counts.lock);
offset += blocks;
if (sectors > blocks)
sectors -= blocks;
else
sectors = 0;
}
return 0;
}
EXPORT_SYMBOL(md_bitmap_startwrite);
void md_bitmap_endwrite(struct bitmap *bitmap, sector_t offset,
unsigned long sectors, int success, int behind)
{
if (!bitmap)
return;
if (behind) {
if (atomic_dec_and_test(&bitmap->behind_writes))
wake_up(&bitmap->behind_wait);
pr_debug("dec write-behind count %d/%lu\n",
atomic_read(&bitmap->behind_writes),
bitmap->mddev->bitmap_info.max_write_behind);
}
while (sectors) {
sector_t blocks;
unsigned long flags;
bitmap_counter_t *bmc;
spin_lock_irqsave(&bitmap->counts.lock, flags);
bmc = md_bitmap_get_counter(&bitmap->counts, offset, &blocks, 0);
if (!bmc) {
spin_unlock_irqrestore(&bitmap->counts.lock, flags);
return;
}
if (success && !bitmap->mddev->degraded &&
bitmap->events_cleared < bitmap->mddev->events) {
bitmap->events_cleared = bitmap->mddev->events;
bitmap->need_sync = 1;
sysfs_notify_dirent_safe(bitmap->sysfs_can_clear);
}
if (!success && !NEEDED(*bmc))
*bmc |= NEEDED_MASK;
if (COUNTER(*bmc) == COUNTER_MAX)
wake_up(&bitmap->overflow_wait);
(*bmc)--;
if (*bmc <= 2) {
md_bitmap_set_pending(&bitmap->counts, offset);
bitmap->allclean = 0;
}
spin_unlock_irqrestore(&bitmap->counts.lock, flags);
offset += blocks;
if (sectors > blocks)
sectors -= blocks;
else
sectors = 0;
}
}
EXPORT_SYMBOL(md_bitmap_endwrite);
static int __bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
int degraded)
{
bitmap_counter_t *bmc;
int rv;
if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */
*blocks = 1024;
return 1; /* always resync if no bitmap */
}
spin_lock_irq(&bitmap->counts.lock);
bmc = md_bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
rv = 0;
if (bmc) {
/* locked */
if (RESYNC(*bmc))
rv = 1;
else if (NEEDED(*bmc)) {
rv = 1;
if (!degraded) { /* don't set/clear bits if degraded */
*bmc |= RESYNC_MASK;
*bmc &= ~NEEDED_MASK;
}
}
}
spin_unlock_irq(&bitmap->counts.lock);
return rv;
}
int md_bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks,
int degraded)
{
/* bitmap_start_sync must always report on multiples of whole
* pages, otherwise resync (which is very PAGE_SIZE based) will
* get confused.
* So call __bitmap_start_sync repeatedly (if needed) until
* At least PAGE_SIZE>>9 blocks are covered.
* Return the 'or' of the result.
*/
int rv = 0;
sector_t blocks1;
*blocks = 0;
while (*blocks < (PAGE_SIZE>>9)) {
rv |= __bitmap_start_sync(bitmap, offset,
&blocks1, degraded);
offset += blocks1;
*blocks += blocks1;
}
return rv;
}
EXPORT_SYMBOL(md_bitmap_start_sync);
void md_bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted)
{
bitmap_counter_t *bmc;
unsigned long flags;
if (bitmap == NULL) {
*blocks = 1024;
return;
}
spin_lock_irqsave(&bitmap->counts.lock, flags);
bmc = md_bitmap_get_counter(&bitmap->counts, offset, blocks, 0);
if (bmc == NULL)
goto unlock;
/* locked */
if (RESYNC(*bmc)) {
*bmc &= ~RESYNC_MASK;
if (!NEEDED(*bmc) && aborted)
*bmc |= NEEDED_MASK;
else {
if (*bmc <= 2) {
md_bitmap_set_pending(&bitmap->counts, offset);
bitmap->allclean = 0;
}
}
}
unlock:
spin_unlock_irqrestore(&bitmap->counts.lock, flags);
}
EXPORT_SYMBOL(md_bitmap_end_sync);
void md_bitmap_close_sync(struct bitmap *bitmap)
{
/* Sync has finished, and any bitmap chunks that weren't synced
* properly have been aborted. It remains to us to clear the
* RESYNC bit wherever it is still on
*/
sector_t sector = 0;
sector_t blocks;
if (!bitmap)
return;
while (sector < bitmap->mddev->resync_max_sectors) {
md_bitmap_end_sync(bitmap, sector, &blocks, 0);
sector += blocks;
}
}
EXPORT_SYMBOL(md_bitmap_close_sync);
void md_bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector, bool force)
{
sector_t s = 0;
sector_t blocks;
if (!bitmap)
return;
if (sector == 0) {
bitmap->last_end_sync = jiffies;
return;
}
if (!force && time_before(jiffies, (bitmap->last_end_sync
+ bitmap->mddev->bitmap_info.daemon_sleep)))
return;
wait_event(bitmap->mddev->recovery_wait,
atomic_read(&bitmap->mddev->recovery_active) == 0);
bitmap->mddev->curr_resync_completed = sector;
set_bit(MD_SB_CHANGE_CLEAN, &bitmap->mddev->sb_flags);
sector &= ~((1ULL << bitmap->counts.chunkshift) - 1);
s = 0;
while (s < sector && s < bitmap->mddev->resync_max_sectors) {
md_bitmap_end_sync(bitmap, s, &blocks, 0);
s += blocks;
}
bitmap->last_end_sync = jiffies;
sysfs_notify_dirent_safe(bitmap->mddev->sysfs_completed);
}
EXPORT_SYMBOL(md_bitmap_cond_end_sync);
void md_bitmap_sync_with_cluster(struct mddev *mddev,
sector_t old_lo, sector_t old_hi,
sector_t new_lo, sector_t new_hi)
{
struct bitmap *bitmap = mddev->bitmap;
sector_t sector, blocks = 0;
for (sector = old_lo; sector < new_lo; ) {
md_bitmap_end_sync(bitmap, sector, &blocks, 0);
sector += blocks;
}
WARN((blocks > new_lo) && old_lo, "alignment is not correct for lo\n");
for (sector = old_hi; sector < new_hi; ) {
md_bitmap_start_sync(bitmap, sector, &blocks, 0);
sector += blocks;
}
WARN((blocks > new_hi) && old_hi, "alignment is not correct for hi\n");
}
EXPORT_SYMBOL(md_bitmap_sync_with_cluster);
static void md_bitmap_set_memory_bits(struct bitmap *bitmap, sector_t offset, int needed)
{
/* For each chunk covered by any of these sectors, set the
* counter to 2 and possibly set resync_needed. They should all
* be 0 at this point
*/
sector_t secs;
bitmap_counter_t *bmc;
spin_lock_irq(&bitmap->counts.lock);
bmc = md_bitmap_get_counter(&bitmap->counts, offset, &secs, 1);
if (!bmc) {
spin_unlock_irq(&bitmap->counts.lock);
return;
}
if (!*bmc) {
*bmc = 2;
md_bitmap_count_page(&bitmap->counts, offset, 1);
md_bitmap_set_pending(&bitmap->counts, offset);
bitmap->allclean = 0;
}
if (needed)
*bmc |= NEEDED_MASK;
spin_unlock_irq(&bitmap->counts.lock);
}
/* dirty the memory and file bits for bitmap chunks "s" to "e" */
void md_bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e)
{
unsigned long chunk;
for (chunk = s; chunk <= e; chunk++) {
sector_t sec = (sector_t)chunk << bitmap->counts.chunkshift;
md_bitmap_set_memory_bits(bitmap, sec, 1);
md_bitmap_file_set_bit(bitmap, sec);
if (sec < bitmap->mddev->recovery_cp)
/* We are asserting that the array is dirty,
* so move the recovery_cp address back so
* that it is obvious that it is dirty
*/
bitmap->mddev->recovery_cp = sec;
}
}
/*
* flush out any pending updates
*/
void md_bitmap_flush(struct mddev *mddev)
{
struct bitmap *bitmap = mddev->bitmap;
long sleep;
if (!bitmap) /* there was no bitmap */
return;
/* run the daemon_work three time to ensure everything is flushed
* that can be
*/
sleep = mddev->bitmap_info.daemon_sleep * 2;
bitmap->daemon_lastrun -= sleep;
md_bitmap_daemon_work(mddev);
bitmap->daemon_lastrun -= sleep;
md_bitmap_daemon_work(mddev);
bitmap->daemon_lastrun -= sleep;
md_bitmap_daemon_work(mddev);
if (mddev->bitmap_info.external)
md_super_wait(mddev);
md_bitmap_update_sb(bitmap);
}
/*
* free memory that was allocated
*/
void md_bitmap_free(struct bitmap *bitmap)
{
unsigned long k, pages;
struct bitmap_page *bp;
if (!bitmap) /* there was no bitmap */
return;
if (bitmap->sysfs_can_clear)
sysfs_put(bitmap->sysfs_can_clear);
if (mddev_is_clustered(bitmap->mddev) && bitmap->mddev->cluster_info &&
bitmap->cluster_slot == md_cluster_ops->slot_number(bitmap->mddev))
md_cluster_stop(bitmap->mddev);
/* Shouldn't be needed - but just in case.... */
wait_event(bitmap->write_wait,
atomic_read(&bitmap->pending_writes) == 0);
/* release the bitmap file */
md_bitmap_file_unmap(&bitmap->storage);
bp = bitmap->counts.bp;
pages = bitmap->counts.pages;
/* free all allocated memory */
if (bp) /* deallocate the page memory */
for (k = 0; k < pages; k++)
if (bp[k].map && !bp[k].hijacked)
kfree(bp[k].map);
kfree(bp);
kfree(bitmap);
}
EXPORT_SYMBOL(md_bitmap_free);
void md_bitmap_wait_behind_writes(struct mddev *mddev)
{
struct bitmap *bitmap = mddev->bitmap;
/* wait for behind writes to complete */
if (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
pr_debug("md:%s: behind writes in progress - waiting to stop.\n",
mdname(mddev));
/* need to kick something here to make sure I/O goes? */
wait_event(bitmap->behind_wait,
atomic_read(&bitmap->behind_writes) == 0);
}
}
void md_bitmap_destroy(struct mddev *mddev)
{
struct bitmap *bitmap = mddev->bitmap;
if (!bitmap) /* there was no bitmap */
return;
md_bitmap_wait_behind_writes(mddev);
if (!mddev->serialize_policy)
mddev_destroy_serial_pool(mddev, NULL, true);
mutex_lock(&mddev->bitmap_info.mutex);
spin_lock(&mddev->lock);
mddev->bitmap = NULL; /* disconnect from the md device */
spin_unlock(&mddev->lock);
mutex_unlock(&mddev->bitmap_info.mutex);
mddev_set_timeout(mddev, MAX_SCHEDULE_TIMEOUT, true);
md_bitmap_free(bitmap);
}
/*
* initialize the bitmap structure
* if this returns an error, bitmap_destroy must be called to do clean up
* once mddev->bitmap is set
*/
struct bitmap *md_bitmap_create(struct mddev *mddev, int slot)
{
struct bitmap *bitmap;
sector_t blocks = mddev->resync_max_sectors;
struct file *file = mddev->bitmap_info.file;
int err;
struct kernfs_node *bm = NULL;
BUILD_BUG_ON(sizeof(bitmap_super_t) != 256);
BUG_ON(file && mddev->bitmap_info.offset);
if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) {
pr_notice("md/raid:%s: array with journal cannot have bitmap\n",
mdname(mddev));
return ERR_PTR(-EBUSY);
}
bitmap = kzalloc(sizeof(*bitmap), GFP_KERNEL);
if (!bitmap)
return ERR_PTR(-ENOMEM);
spin_lock_init(&bitmap->counts.lock);
atomic_set(&bitmap->pending_writes, 0);
init_waitqueue_head(&bitmap->write_wait);
init_waitqueue_head(&bitmap->overflow_wait);
init_waitqueue_head(&bitmap->behind_wait);
bitmap->mddev = mddev;
bitmap->cluster_slot = slot;
if (mddev->kobj.sd)
bm = sysfs_get_dirent(mddev->kobj.sd, "bitmap");
if (bm) {
bitmap->sysfs_can_clear = sysfs_get_dirent(bm, "can_clear");
sysfs_put(bm);
} else
bitmap->sysfs_can_clear = NULL;
bitmap->storage.file = file;
if (file) {
get_file(file);
/* As future accesses to this file will use bmap,
* and bypass the page cache, we must sync the file
* first.
*/
vfs_fsync(file, 1);
}
/* read superblock from bitmap file (this sets mddev->bitmap_info.chunksize) */
if (!mddev->bitmap_info.external) {
/*
* If 'MD_ARRAY_FIRST_USE' is set, then device-mapper is
* instructing us to create a new on-disk bitmap instance.
*/
if (test_and_clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags))
err = md_bitmap_new_disk_sb(bitmap);
else
err = md_bitmap_read_sb(bitmap);
} else {
err = 0;
if (mddev->bitmap_info.chunksize == 0 ||
mddev->bitmap_info.daemon_sleep == 0)
/* chunksize and time_base need to be
* set first. */
err = -EINVAL;
}
if (err)
goto error;
bitmap->daemon_lastrun = jiffies;
err = md_bitmap_resize(bitmap, blocks, mddev->bitmap_info.chunksize, 1);
if (err)
goto error;
pr_debug("created bitmap (%lu pages) for device %s\n",
bitmap->counts.pages, bmname(bitmap));
err = test_bit(BITMAP_WRITE_ERROR, &bitmap->flags) ? -EIO : 0;
if (err)
goto error;
return bitmap;
error:
md_bitmap_free(bitmap);
return ERR_PTR(err);
}
int md_bitmap_load(struct mddev *mddev)
{
int err = 0;
sector_t start = 0;
sector_t sector = 0;
struct bitmap *bitmap = mddev->bitmap;
struct md_rdev *rdev;
if (!bitmap)
goto out;
rdev_for_each(rdev, mddev)
mddev_create_serial_pool(mddev, rdev, true);
if (mddev_is_clustered(mddev))
md_cluster_ops->load_bitmaps(mddev, mddev->bitmap_info.nodes);
/* Clear out old bitmap info first: Either there is none, or we
* are resuming after someone else has possibly changed things,
* so we should forget old cached info.
* All chunks should be clean, but some might need_sync.
*/
while (sector < mddev->resync_max_sectors) {
sector_t blocks;
md_bitmap_start_sync(bitmap, sector, &blocks, 0);
sector += blocks;
}
md_bitmap_close_sync(bitmap);
if (mddev->degraded == 0
|| bitmap->events_cleared == mddev->events)
/* no need to keep dirty bits to optimise a
* re-add of a missing device */
start = mddev->recovery_cp;
mutex_lock(&mddev->bitmap_info.mutex);
err = md_bitmap_init_from_disk(bitmap, start);
mutex_unlock(&mddev->bitmap_info.mutex);
if (err)
goto out;
clear_bit(BITMAP_STALE, &bitmap->flags);
/* Kick recovery in case any bits were set */
set_bit(MD_RECOVERY_NEEDED, &bitmap->mddev->recovery);
mddev_set_timeout(mddev, mddev->bitmap_info.daemon_sleep, true);
md_wakeup_thread(mddev->thread);
md_bitmap_update_sb(bitmap);
if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags))
err = -EIO;
out:
return err;
}
EXPORT_SYMBOL_GPL(md_bitmap_load);
/* caller need to free returned bitmap with md_bitmap_free() */
struct bitmap *get_bitmap_from_slot(struct mddev *mddev, int slot)
{
int rv = 0;
struct bitmap *bitmap;
bitmap = md_bitmap_create(mddev, slot);
if (IS_ERR(bitmap)) {
rv = PTR_ERR(bitmap);
return ERR_PTR(rv);
}
rv = md_bitmap_init_from_disk(bitmap, 0);
if (rv) {
md_bitmap_free(bitmap);
return ERR_PTR(rv);
}
return bitmap;
}
EXPORT_SYMBOL(get_bitmap_from_slot);
/* Loads the bitmap associated with slot and copies the resync information
* to our bitmap
*/
int md_bitmap_copy_from_slot(struct mddev *mddev, int slot,
sector_t *low, sector_t *high, bool clear_bits)
{
int rv = 0, i, j;
sector_t block, lo = 0, hi = 0;
struct bitmap_counts *counts;
struct bitmap *bitmap;
bitmap = get_bitmap_from_slot(mddev, slot);
if (IS_ERR(bitmap)) {
pr_err("%s can't get bitmap from slot %d\n", __func__, slot);
return -1;
}
counts = &bitmap->counts;
for (j = 0; j < counts->chunks; j++) {
block = (sector_t)j << counts->chunkshift;
if (md_bitmap_file_test_bit(bitmap, block)) {
if (!lo)
lo = block;
hi = block;
md_bitmap_file_clear_bit(bitmap, block);
md_bitmap_set_memory_bits(mddev->bitmap, block, 1);
md_bitmap_file_set_bit(mddev->bitmap, block);
}
}
if (clear_bits) {
md_bitmap_update_sb(bitmap);
/* BITMAP_PAGE_PENDING is set, but bitmap_unplug needs
* BITMAP_PAGE_DIRTY or _NEEDWRITE to write ... */
for (i = 0; i < bitmap->storage.file_pages; i++)
if (test_page_attr(bitmap, i, BITMAP_PAGE_PENDING))
set_page_attr(bitmap, i, BITMAP_PAGE_NEEDWRITE);
md_bitmap_unplug(bitmap);
}
md_bitmap_unplug(mddev->bitmap);
*low = lo;
*high = hi;
md_bitmap_free(bitmap);
return rv;
}
EXPORT_SYMBOL_GPL(md_bitmap_copy_from_slot);
void md_bitmap_status(struct seq_file *seq, struct bitmap *bitmap)
{
unsigned long chunk_kb;
struct bitmap_counts *counts;
if (!bitmap)
return;
counts = &bitmap->counts;
chunk_kb = bitmap->mddev->bitmap_info.chunksize >> 10;
seq_printf(seq, "bitmap: %lu/%lu pages [%luKB], "
"%lu%s chunk",
counts->pages - counts->missing_pages,
counts->pages,
(counts->pages - counts->missing_pages)
<< (PAGE_SHIFT - 10),
chunk_kb ? chunk_kb : bitmap->mddev->bitmap_info.chunksize,
chunk_kb ? "KB" : "B");
if (bitmap->storage.file) {
seq_printf(seq, ", file: ");
seq_file_path(seq, bitmap->storage.file, " \t\n");
}
seq_printf(seq, "\n");
}
int md_bitmap_resize(struct bitmap *bitmap, sector_t blocks,
int chunksize, int init)
{
/* If chunk_size is 0, choose an appropriate chunk size.
* Then possibly allocate new storage space.
* Then quiesce, copy bits, replace bitmap, and re-start
*
* This function is called both to set up the initial bitmap
* and to resize the bitmap while the array is active.
* If this happens as a result of the array being resized,
* chunksize will be zero, and we need to choose a suitable
* chunksize, otherwise we use what we are given.
*/
struct bitmap_storage store;
struct bitmap_counts old_counts;
unsigned long chunks;
sector_t block;
sector_t old_blocks, new_blocks;
int chunkshift;
int ret = 0;
long pages;
struct bitmap_page *new_bp;
if (bitmap->storage.file && !init) {
pr_info("md: cannot resize file-based bitmap\n");
return -EINVAL;
}
if (chunksize == 0) {
/* If there is enough space, leave the chunk size unchanged,
* else increase by factor of two until there is enough space.
*/
long bytes;
long space = bitmap->mddev->bitmap_info.space;
if (space == 0) {
/* We don't know how much space there is, so limit
* to current size - in sectors.
*/
bytes = DIV_ROUND_UP(bitmap->counts.chunks, 8);
if (!bitmap->mddev->bitmap_info.external)
bytes += sizeof(bitmap_super_t);
space = DIV_ROUND_UP(bytes, 512);
bitmap->mddev->bitmap_info.space = space;
}
chunkshift = bitmap->counts.chunkshift;
chunkshift--;
do {
/* 'chunkshift' is shift from block size to chunk size */
chunkshift++;
chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
bytes = DIV_ROUND_UP(chunks, 8);
if (!bitmap->mddev->bitmap_info.external)
bytes += sizeof(bitmap_super_t);
} while (bytes > (space << 9) && (chunkshift + BITMAP_BLOCK_SHIFT) <
(BITS_PER_BYTE * sizeof(((bitmap_super_t *)0)->chunksize) - 1));
} else
chunkshift = ffz(~chunksize) - BITMAP_BLOCK_SHIFT;
chunks = DIV_ROUND_UP_SECTOR_T(blocks, 1 << chunkshift);
memset(&store, 0, sizeof(store));
if (bitmap->mddev->bitmap_info.offset || bitmap->mddev->bitmap_info.file)
ret = md_bitmap_storage_alloc(&store, chunks,
!bitmap->mddev->bitmap_info.external,
mddev_is_clustered(bitmap->mddev)
? bitmap->cluster_slot : 0);
if (ret) {
md_bitmap_file_unmap(&store);
goto err;
}
pages = DIV_ROUND_UP(chunks, PAGE_COUNTER_RATIO);
new_bp = kcalloc(pages, sizeof(*new_bp), GFP_KERNEL);
ret = -ENOMEM;
if (!new_bp) {
md_bitmap_file_unmap(&store);
goto err;
}
if (!init)
bitmap->mddev->pers->quiesce(bitmap->mddev, 1);
store.file = bitmap->storage.file;
bitmap->storage.file = NULL;
if (store.sb_page && bitmap->storage.sb_page)
memcpy(page_address(store.sb_page),
page_address(bitmap->storage.sb_page),
sizeof(bitmap_super_t));
spin_lock_irq(&bitmap->counts.lock);
md_bitmap_file_unmap(&bitmap->storage);
bitmap->storage = store;
old_counts = bitmap->counts;
bitmap->counts.bp = new_bp;
bitmap->counts.pages = pages;
bitmap->counts.missing_pages = pages;
bitmap->counts.chunkshift = chunkshift;
bitmap->counts.chunks = chunks;
bitmap->mddev->bitmap_info.chunksize = 1UL << (chunkshift +
BITMAP_BLOCK_SHIFT);
blocks = min(old_counts.chunks << old_counts.chunkshift,
chunks << chunkshift);
/* For cluster raid, need to pre-allocate bitmap */
if (mddev_is_clustered(bitmap->mddev)) {
unsigned long page;
for (page = 0; page < pages; page++) {
ret = md_bitmap_checkpage(&bitmap->counts, page, 1, 1);
if (ret) {
unsigned long k;
/* deallocate the page memory */
for (k = 0; k < page; k++) {
kfree(new_bp[k].map);
}
kfree(new_bp);
/* restore some fields from old_counts */
bitmap->counts.bp = old_counts.bp;
bitmap->counts.pages = old_counts.pages;
bitmap->counts.missing_pages = old_counts.pages;
bitmap->counts.chunkshift = old_counts.chunkshift;
bitmap->counts.chunks = old_counts.chunks;
bitmap->mddev->bitmap_info.chunksize =
1UL << (old_counts.chunkshift + BITMAP_BLOCK_SHIFT);
blocks = old_counts.chunks << old_counts.chunkshift;
pr_warn("Could not pre-allocate in-memory bitmap for cluster raid\n");
break;
} else
bitmap->counts.bp[page].count += 1;
}
}
for (block = 0; block < blocks; ) {
bitmap_counter_t *bmc_old, *bmc_new;
int set;
bmc_old = md_bitmap_get_counter(&old_counts, block, &old_blocks, 0);
set = bmc_old && NEEDED(*bmc_old);
if (set) {
bmc_new = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1);
if (bmc_new) {
if (*bmc_new == 0) {
/* need to set on-disk bits too. */
sector_t end = block + new_blocks;
sector_t start = block >> chunkshift;
start <<= chunkshift;
while (start < end) {
md_bitmap_file_set_bit(bitmap, block);
start += 1 << chunkshift;
}
*bmc_new = 2;
md_bitmap_count_page(&bitmap->counts, block, 1);
md_bitmap_set_pending(&bitmap->counts, block);
}
*bmc_new |= NEEDED_MASK;
}
if (new_blocks < old_blocks)
old_blocks = new_blocks;
}
block += old_blocks;
}
if (bitmap->counts.bp != old_counts.bp) {
unsigned long k;
for (k = 0; k < old_counts.pages; k++)
if (!old_counts.bp[k].hijacked)
kfree(old_counts.bp[k].map);
kfree(old_counts.bp);
}
if (!init) {
int i;
while (block < (chunks << chunkshift)) {
bitmap_counter_t *bmc;
bmc = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1);
if (bmc) {
/* new space. It needs to be resynced, so
* we set NEEDED_MASK.
*/
if (*bmc == 0) {
*bmc = NEEDED_MASK | 2;
md_bitmap_count_page(&bitmap->counts, block, 1);
md_bitmap_set_pending(&bitmap->counts, block);
}
}
block += new_blocks;
}
for (i = 0; i < bitmap->storage.file_pages; i++)
set_page_attr(bitmap, i, BITMAP_PAGE_DIRTY);
}
spin_unlock_irq(&bitmap->counts.lock);
if (!init) {
md_bitmap_unplug(bitmap);
bitmap->mddev->pers->quiesce(bitmap->mddev, 0);
}
ret = 0;
err:
return ret;
}
EXPORT_SYMBOL_GPL(md_bitmap_resize);
static ssize_t
location_show(struct mddev *mddev, char *page)
{
ssize_t len;
if (mddev->bitmap_info.file)
len = sprintf(page, "file");
else if (mddev->bitmap_info.offset)
len = sprintf(page, "%+lld", (long long)mddev->bitmap_info.offset);
else
len = sprintf(page, "none");
len += sprintf(page+len, "\n");
return len;
}
static ssize_t
location_store(struct mddev *mddev, const char *buf, size_t len)
{
int rv;
rv = mddev_lock(mddev);
if (rv)
return rv;
if (mddev->pers) {
if (!mddev->pers->quiesce) {
rv = -EBUSY;
goto out;
}
if (mddev->recovery || mddev->sync_thread) {
rv = -EBUSY;
goto out;
}
}
if (mddev->bitmap || mddev->bitmap_info.file ||
mddev->bitmap_info.offset) {
/* bitmap already configured. Only option is to clear it */
if (strncmp(buf, "none", 4) != 0) {
rv = -EBUSY;
goto out;
}
if (mddev->pers) {
mddev_suspend(mddev);
md_bitmap_destroy(mddev);
mddev_resume(mddev);
}
mddev->bitmap_info.offset = 0;
if (mddev->bitmap_info.file) {
struct file *f = mddev->bitmap_info.file;
mddev->bitmap_info.file = NULL;
fput(f);
}
} else {
/* No bitmap, OK to set a location */
long long offset;
if (strncmp(buf, "none", 4) == 0)
/* nothing to be done */;
else if (strncmp(buf, "file:", 5) == 0) {
/* Not supported yet */
rv = -EINVAL;
goto out;
} else {
if (buf[0] == '+')
rv = kstrtoll(buf+1, 10, &offset);
else
rv = kstrtoll(buf, 10, &offset);
if (rv)
goto out;
if (offset == 0) {
rv = -EINVAL;
goto out;
}
if (mddev->bitmap_info.external == 0 &&
mddev->major_version == 0 &&
offset != mddev->bitmap_info.default_offset) {
rv = -EINVAL;
goto out;
}
mddev->bitmap_info.offset = offset;
if (mddev->pers) {
struct bitmap *bitmap;
bitmap = md_bitmap_create(mddev, -1);
mddev_suspend(mddev);
if (IS_ERR(bitmap))
rv = PTR_ERR(bitmap);
else {
mddev->bitmap = bitmap;
rv = md_bitmap_load(mddev);
if (rv)
mddev->bitmap_info.offset = 0;
}
if (rv) {
md_bitmap_destroy(mddev);
mddev_resume(mddev);
goto out;
}
mddev_resume(mddev);
}
}
}
if (!mddev->external) {
/* Ensure new bitmap info is stored in
* metadata promptly.
*/
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
md_wakeup_thread(mddev->thread);
}
rv = 0;
out:
mddev_unlock(mddev);
if (rv)
return rv;
return len;
}
static struct md_sysfs_entry bitmap_location =
__ATTR(location, S_IRUGO|S_IWUSR, location_show, location_store);
/* 'bitmap/space' is the space available at 'location' for the
* bitmap. This allows the kernel to know when it is safe to
* resize the bitmap to match a resized array.
*/
static ssize_t
space_show(struct mddev *mddev, char *page)
{
return sprintf(page, "%lu\n", mddev->bitmap_info.space);
}
static ssize_t
space_store(struct mddev *mddev, const char *buf, size_t len)
{
unsigned long sectors;
int rv;
rv = kstrtoul(buf, 10, §ors);
if (rv)
return rv;
if (sectors == 0)
return -EINVAL;
if (mddev->bitmap &&
sectors < (mddev->bitmap->storage.bytes + 511) >> 9)
return -EFBIG; /* Bitmap is too big for this small space */
/* could make sure it isn't too big, but that isn't really
* needed - user-space should be careful.
*/
mddev->bitmap_info.space = sectors;
return len;
}
static struct md_sysfs_entry bitmap_space =
__ATTR(space, S_IRUGO|S_IWUSR, space_show, space_store);
static ssize_t
timeout_show(struct mddev *mddev, char *page)
{
ssize_t len;
unsigned long secs = mddev->bitmap_info.daemon_sleep / HZ;
unsigned long jifs = mddev->bitmap_info.daemon_sleep % HZ;
len = sprintf(page, "%lu", secs);
if (jifs)
len += sprintf(page+len, ".%03u", jiffies_to_msecs(jifs));
len += sprintf(page+len, "\n");
return len;
}
static ssize_t
timeout_store(struct mddev *mddev, const char *buf, size_t len)
{
/* timeout can be set at any time */
unsigned long timeout;
int rv = strict_strtoul_scaled(buf, &timeout, 4);
if (rv)
return rv;
/* just to make sure we don't overflow... */
if (timeout >= LONG_MAX / HZ)
return -EINVAL;
timeout = timeout * HZ / 10000;
if (timeout >= MAX_SCHEDULE_TIMEOUT)
timeout = MAX_SCHEDULE_TIMEOUT-1;
if (timeout < 1)
timeout = 1;
mddev->bitmap_info.daemon_sleep = timeout;
mddev_set_timeout(mddev, timeout, false);
md_wakeup_thread(mddev->thread);
return len;
}
static struct md_sysfs_entry bitmap_timeout =
__ATTR(time_base, S_IRUGO|S_IWUSR, timeout_show, timeout_store);
static ssize_t
backlog_show(struct mddev *mddev, char *page)
{
return sprintf(page, "%lu\n", mddev->bitmap_info.max_write_behind);
}
static ssize_t
backlog_store(struct mddev *mddev, const char *buf, size_t len)
{
unsigned long backlog;
unsigned long old_mwb = mddev->bitmap_info.max_write_behind;
struct md_rdev *rdev;
bool has_write_mostly = false;
int rv = kstrtoul(buf, 10, &backlog);
if (rv)
return rv;
if (backlog > COUNTER_MAX)
return -EINVAL;
rv = mddev_lock(mddev);
if (rv)
return rv;
/*
* Without write mostly device, it doesn't make sense to set
* backlog for max_write_behind.
*/
rdev_for_each(rdev, mddev) {
if (test_bit(WriteMostly, &rdev->flags)) {
has_write_mostly = true;
break;
}
}
if (!has_write_mostly) {
pr_warn_ratelimited("%s: can't set backlog, no write mostly device available\n",
mdname(mddev));
mddev_unlock(mddev);
return -EINVAL;
}
mddev->bitmap_info.max_write_behind = backlog;
if (!backlog && mddev->serial_info_pool) {
/* serial_info_pool is not needed if backlog is zero */
if (!mddev->serialize_policy)
mddev_destroy_serial_pool(mddev, NULL, false);
} else if (backlog && !mddev->serial_info_pool) {
/* serial_info_pool is needed since backlog is not zero */
rdev_for_each(rdev, mddev)
mddev_create_serial_pool(mddev, rdev, false);
}
if (old_mwb != backlog)
md_bitmap_update_sb(mddev->bitmap);
mddev_unlock(mddev);
return len;
}
static struct md_sysfs_entry bitmap_backlog =
__ATTR(backlog, S_IRUGO|S_IWUSR, backlog_show, backlog_store);
static ssize_t
chunksize_show(struct mddev *mddev, char *page)
{
return sprintf(page, "%lu\n", mddev->bitmap_info.chunksize);
}
static ssize_t
chunksize_store(struct mddev *mddev, const char *buf, size_t len)
{
/* Can only be changed when no bitmap is active */
int rv;
unsigned long csize;
if (mddev->bitmap)
return -EBUSY;
rv = kstrtoul(buf, 10, &csize);
if (rv)
return rv;
if (csize < 512 ||
!is_power_of_2(csize))
return -EINVAL;
if (BITS_PER_LONG > 32 && csize >= (1ULL << (BITS_PER_BYTE *
sizeof(((bitmap_super_t *)0)->chunksize))))
return -EOVERFLOW;
mddev->bitmap_info.chunksize = csize;
return len;
}
static struct md_sysfs_entry bitmap_chunksize =
__ATTR(chunksize, S_IRUGO|S_IWUSR, chunksize_show, chunksize_store);
static ssize_t metadata_show(struct mddev *mddev, char *page)
{
if (mddev_is_clustered(mddev))
return sprintf(page, "clustered\n");
return sprintf(page, "%s\n", (mddev->bitmap_info.external
? "external" : "internal"));
}
static ssize_t metadata_store(struct mddev *mddev, const char *buf, size_t len)
{
if (mddev->bitmap ||
mddev->bitmap_info.file ||
mddev->bitmap_info.offset)
return -EBUSY;
if (strncmp(buf, "external", 8) == 0)
mddev->bitmap_info.external = 1;
else if ((strncmp(buf, "internal", 8) == 0) ||
(strncmp(buf, "clustered", 9) == 0))
mddev->bitmap_info.external = 0;
else
return -EINVAL;
return len;
}
static struct md_sysfs_entry bitmap_metadata =
__ATTR(metadata, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
static ssize_t can_clear_show(struct mddev *mddev, char *page)
{
int len;
spin_lock(&mddev->lock);
if (mddev->bitmap)
len = sprintf(page, "%s\n", (mddev->bitmap->need_sync ?
"false" : "true"));
else
len = sprintf(page, "\n");
spin_unlock(&mddev->lock);
return len;
}
static ssize_t can_clear_store(struct mddev *mddev, const char *buf, size_t len)
{
if (mddev->bitmap == NULL)
return -ENOENT;
if (strncmp(buf, "false", 5) == 0)
mddev->bitmap->need_sync = 1;
else if (strncmp(buf, "true", 4) == 0) {
if (mddev->degraded)
return -EBUSY;
mddev->bitmap->need_sync = 0;
} else
return -EINVAL;
return len;
}
static struct md_sysfs_entry bitmap_can_clear =
__ATTR(can_clear, S_IRUGO|S_IWUSR, can_clear_show, can_clear_store);
static ssize_t
behind_writes_used_show(struct mddev *mddev, char *page)
{
ssize_t ret;
spin_lock(&mddev->lock);
if (mddev->bitmap == NULL)
ret = sprintf(page, "0\n");
else
ret = sprintf(page, "%lu\n",
mddev->bitmap->behind_writes_used);
spin_unlock(&mddev->lock);
return ret;
}
static ssize_t
behind_writes_used_reset(struct mddev *mddev, const char *buf, size_t len)
{
if (mddev->bitmap)
mddev->bitmap->behind_writes_used = 0;
return len;
}
static struct md_sysfs_entry max_backlog_used =
__ATTR(max_backlog_used, S_IRUGO | S_IWUSR,
behind_writes_used_show, behind_writes_used_reset);
static struct attribute *md_bitmap_attrs[] = {
&bitmap_location.attr,
&bitmap_space.attr,
&bitmap_timeout.attr,
&bitmap_backlog.attr,
&bitmap_chunksize.attr,
&bitmap_metadata.attr,
&bitmap_can_clear.attr,
&max_backlog_used.attr,
NULL
};
const struct attribute_group md_bitmap_group = {
.name = "bitmap",
.attrs = md_bitmap_attrs,
};
| linux-master | drivers/md/md-bitmap.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2019 Arrikto, Inc. All Rights Reserved.
*/
#include <linux/mm.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/rwsem.h>
#include <linux/bitops.h>
#include <linux/bitmap.h>
#include <linux/device-mapper.h>
#include "persistent-data/dm-bitset.h"
#include "persistent-data/dm-space-map.h"
#include "persistent-data/dm-block-manager.h"
#include "persistent-data/dm-transaction-manager.h"
#include "dm-clone-metadata.h"
#define DM_MSG_PREFIX "clone metadata"
#define SUPERBLOCK_LOCATION 0
#define SUPERBLOCK_MAGIC 0x8af27f64
#define SUPERBLOCK_CSUM_XOR 257649492
#define DM_CLONE_MAX_CONCURRENT_LOCKS 5
#define UUID_LEN 16
/* Min and max dm-clone metadata versions supported */
#define DM_CLONE_MIN_METADATA_VERSION 1
#define DM_CLONE_MAX_METADATA_VERSION 1
/*
* On-disk metadata layout
*/
struct superblock_disk {
__le32 csum;
__le32 flags;
__le64 blocknr;
__u8 uuid[UUID_LEN];
__le64 magic;
__le32 version;
__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
__le64 region_size;
__le64 target_size;
__le64 bitset_root;
} __packed;
/*
* Region and Dirty bitmaps.
*
* dm-clone logically splits the source and destination devices in regions of
* fixed size. The destination device's regions are gradually hydrated, i.e.,
* we copy (clone) the source's regions to the destination device. Eventually,
* all regions will get hydrated and all I/O will be served from the
* destination device.
*
* We maintain an on-disk bitmap which tracks the state of each of the
* destination device's regions, i.e., whether they are hydrated or not.
*
* To save constantly doing look ups on disk we keep an in core copy of the
* on-disk bitmap, the region_map.
*
* In order to track which regions are hydrated during a metadata transaction,
* we use a second set of bitmaps, the dmap (dirty bitmap), which includes two
* bitmaps, namely dirty_regions and dirty_words. The dirty_regions bitmap
* tracks the regions that got hydrated during the current metadata
* transaction. The dirty_words bitmap tracks the dirty words, i.e. longs, of
* the dirty_regions bitmap.
*
* This allows us to precisely track the regions that were hydrated during the
* current metadata transaction and update the metadata accordingly, when we
* commit the current transaction. This is important because dm-clone should
* only commit the metadata of regions that were properly flushed to the
* destination device beforehand. Otherwise, in case of a crash, we could end
* up with a corrupted dm-clone device.
*
* When a region finishes hydrating dm-clone calls
* dm_clone_set_region_hydrated(), or for discard requests
* dm_clone_cond_set_range(), which sets the corresponding bits in region_map
* and dmap.
*
* During a metadata commit we scan dmap->dirty_words and dmap->dirty_regions
* and update the on-disk metadata accordingly. Thus, we don't have to flush to
* disk the whole region_map. We can just flush the dirty region_map bits.
*
* We use the helper dmap->dirty_words bitmap, which is smaller than the
* original region_map, to reduce the amount of memory accesses during a
* metadata commit. Moreover, as dm-bitset also accesses the on-disk bitmap in
* 64-bit word granularity, the dirty_words bitmap helps us avoid useless disk
* accesses.
*
* We could update directly the on-disk bitmap, when dm-clone calls either
* dm_clone_set_region_hydrated() or dm_clone_cond_set_range(), buts this
* inserts significant metadata I/O overhead in dm-clone's I/O path. Also, as
* these two functions don't block, we can call them in interrupt context,
* e.g., in a hooked overwrite bio's completion routine, and further reduce the
* I/O completion latency.
*
* We maintain two dirty bitmap sets. During a metadata commit we atomically
* swap the currently used dmap with the unused one. This allows the metadata
* update functions to run concurrently with an ongoing commit.
*/
struct dirty_map {
unsigned long *dirty_words;
unsigned long *dirty_regions;
unsigned int changed;
};
struct dm_clone_metadata {
/* The metadata block device */
struct block_device *bdev;
sector_t target_size;
sector_t region_size;
unsigned long nr_regions;
unsigned long nr_words;
/* Spinlock protecting the region and dirty bitmaps. */
spinlock_t bitmap_lock;
struct dirty_map dmap[2];
struct dirty_map *current_dmap;
/* Protected by lock */
struct dirty_map *committing_dmap;
/*
* In core copy of the on-disk bitmap to save constantly doing look ups
* on disk.
*/
unsigned long *region_map;
/* Protected by bitmap_lock */
unsigned int read_only;
struct dm_block_manager *bm;
struct dm_space_map *sm;
struct dm_transaction_manager *tm;
struct rw_semaphore lock;
struct dm_disk_bitset bitset_info;
dm_block_t bitset_root;
/*
* Reading the space map root can fail, so we read it into this
* buffer before the superblock is locked and updated.
*/
__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
bool hydration_done:1;
bool fail_io:1;
};
/*---------------------------------------------------------------------------*/
/*
* Superblock validation.
*/
static void sb_prepare_for_write(struct dm_block_validator *v,
struct dm_block *b, size_t sb_block_size)
{
struct superblock_disk *sb;
u32 csum;
sb = dm_block_data(b);
sb->blocknr = cpu_to_le64(dm_block_location(b));
csum = dm_bm_checksum(&sb->flags, sb_block_size - sizeof(__le32),
SUPERBLOCK_CSUM_XOR);
sb->csum = cpu_to_le32(csum);
}
static int sb_check(struct dm_block_validator *v, struct dm_block *b,
size_t sb_block_size)
{
struct superblock_disk *sb;
u32 csum, metadata_version;
sb = dm_block_data(b);
if (dm_block_location(b) != le64_to_cpu(sb->blocknr)) {
DMERR("Superblock check failed: blocknr %llu, expected %llu",
le64_to_cpu(sb->blocknr),
(unsigned long long)dm_block_location(b));
return -ENOTBLK;
}
if (le64_to_cpu(sb->magic) != SUPERBLOCK_MAGIC) {
DMERR("Superblock check failed: magic %llu, expected %llu",
le64_to_cpu(sb->magic),
(unsigned long long)SUPERBLOCK_MAGIC);
return -EILSEQ;
}
csum = dm_bm_checksum(&sb->flags, sb_block_size - sizeof(__le32),
SUPERBLOCK_CSUM_XOR);
if (sb->csum != cpu_to_le32(csum)) {
DMERR("Superblock check failed: checksum %u, expected %u",
csum, le32_to_cpu(sb->csum));
return -EILSEQ;
}
/* Check metadata version */
metadata_version = le32_to_cpu(sb->version);
if (metadata_version < DM_CLONE_MIN_METADATA_VERSION ||
metadata_version > DM_CLONE_MAX_METADATA_VERSION) {
DMERR("Clone metadata version %u found, but only versions between %u and %u supported.",
metadata_version, DM_CLONE_MIN_METADATA_VERSION,
DM_CLONE_MAX_METADATA_VERSION);
return -EINVAL;
}
return 0;
}
static struct dm_block_validator sb_validator = {
.name = "superblock",
.prepare_for_write = sb_prepare_for_write,
.check = sb_check
};
/*
* Check if the superblock is formatted or not. We consider the superblock to
* be formatted in case we find non-zero bytes in it.
*/
static int __superblock_all_zeroes(struct dm_block_manager *bm, bool *formatted)
{
int r;
unsigned int i, nr_words;
struct dm_block *sblock;
__le64 *data_le, zero = cpu_to_le64(0);
/*
* We don't use a validator here because the superblock could be all
* zeroes.
*/
r = dm_bm_read_lock(bm, SUPERBLOCK_LOCATION, NULL, &sblock);
if (r) {
DMERR("Failed to read_lock superblock");
return r;
}
data_le = dm_block_data(sblock);
*formatted = false;
/* This assumes that the block size is a multiple of 8 bytes */
BUG_ON(dm_bm_block_size(bm) % sizeof(__le64));
nr_words = dm_bm_block_size(bm) / sizeof(__le64);
for (i = 0; i < nr_words; i++) {
if (data_le[i] != zero) {
*formatted = true;
break;
}
}
dm_bm_unlock(sblock);
return 0;
}
/*---------------------------------------------------------------------------*/
/*
* Low-level metadata handling.
*/
static inline int superblock_read_lock(struct dm_clone_metadata *cmd,
struct dm_block **sblock)
{
return dm_bm_read_lock(cmd->bm, SUPERBLOCK_LOCATION, &sb_validator, sblock);
}
static inline int superblock_write_lock_zero(struct dm_clone_metadata *cmd,
struct dm_block **sblock)
{
return dm_bm_write_lock_zero(cmd->bm, SUPERBLOCK_LOCATION, &sb_validator, sblock);
}
static int __copy_sm_root(struct dm_clone_metadata *cmd)
{
int r;
size_t root_size;
r = dm_sm_root_size(cmd->sm, &root_size);
if (r)
return r;
return dm_sm_copy_root(cmd->sm, &cmd->metadata_space_map_root, root_size);
}
/* Save dm-clone metadata in superblock */
static void __prepare_superblock(struct dm_clone_metadata *cmd,
struct superblock_disk *sb)
{
sb->flags = cpu_to_le32(0UL);
/* FIXME: UUID is currently unused */
memset(sb->uuid, 0, sizeof(sb->uuid));
sb->magic = cpu_to_le64(SUPERBLOCK_MAGIC);
sb->version = cpu_to_le32(DM_CLONE_MAX_METADATA_VERSION);
/* Save the metadata space_map root */
memcpy(&sb->metadata_space_map_root, &cmd->metadata_space_map_root,
sizeof(cmd->metadata_space_map_root));
sb->region_size = cpu_to_le64(cmd->region_size);
sb->target_size = cpu_to_le64(cmd->target_size);
sb->bitset_root = cpu_to_le64(cmd->bitset_root);
}
static int __open_metadata(struct dm_clone_metadata *cmd)
{
int r;
struct dm_block *sblock;
struct superblock_disk *sb;
r = superblock_read_lock(cmd, &sblock);
if (r) {
DMERR("Failed to read_lock superblock");
return r;
}
sb = dm_block_data(sblock);
/* Verify that target_size and region_size haven't changed. */
if (cmd->region_size != le64_to_cpu(sb->region_size) ||
cmd->target_size != le64_to_cpu(sb->target_size)) {
DMERR("Region and/or target size don't match the ones in metadata");
r = -EINVAL;
goto out_with_lock;
}
r = dm_tm_open_with_sm(cmd->bm, SUPERBLOCK_LOCATION,
sb->metadata_space_map_root,
sizeof(sb->metadata_space_map_root),
&cmd->tm, &cmd->sm);
if (r) {
DMERR("dm_tm_open_with_sm failed");
goto out_with_lock;
}
dm_disk_bitset_init(cmd->tm, &cmd->bitset_info);
cmd->bitset_root = le64_to_cpu(sb->bitset_root);
out_with_lock:
dm_bm_unlock(sblock);
return r;
}
static int __format_metadata(struct dm_clone_metadata *cmd)
{
int r;
struct dm_block *sblock;
struct superblock_disk *sb;
r = dm_tm_create_with_sm(cmd->bm, SUPERBLOCK_LOCATION, &cmd->tm, &cmd->sm);
if (r) {
DMERR("Failed to create transaction manager");
return r;
}
dm_disk_bitset_init(cmd->tm, &cmd->bitset_info);
r = dm_bitset_empty(&cmd->bitset_info, &cmd->bitset_root);
if (r) {
DMERR("Failed to create empty on-disk bitset");
goto err_with_tm;
}
r = dm_bitset_resize(&cmd->bitset_info, cmd->bitset_root, 0,
cmd->nr_regions, false, &cmd->bitset_root);
if (r) {
DMERR("Failed to resize on-disk bitset to %lu entries", cmd->nr_regions);
goto err_with_tm;
}
/* Flush to disk all blocks, except the superblock */
r = dm_tm_pre_commit(cmd->tm);
if (r) {
DMERR("dm_tm_pre_commit failed");
goto err_with_tm;
}
r = __copy_sm_root(cmd);
if (r) {
DMERR("__copy_sm_root failed");
goto err_with_tm;
}
r = superblock_write_lock_zero(cmd, &sblock);
if (r) {
DMERR("Failed to write_lock superblock");
goto err_with_tm;
}
sb = dm_block_data(sblock);
__prepare_superblock(cmd, sb);
r = dm_tm_commit(cmd->tm, sblock);
if (r) {
DMERR("Failed to commit superblock");
goto err_with_tm;
}
return 0;
err_with_tm:
dm_sm_destroy(cmd->sm);
dm_tm_destroy(cmd->tm);
return r;
}
static int __open_or_format_metadata(struct dm_clone_metadata *cmd, bool may_format_device)
{
int r;
bool formatted = false;
r = __superblock_all_zeroes(cmd->bm, &formatted);
if (r)
return r;
if (!formatted)
return may_format_device ? __format_metadata(cmd) : -EPERM;
return __open_metadata(cmd);
}
static int __create_persistent_data_structures(struct dm_clone_metadata *cmd,
bool may_format_device)
{
int r;
/* Create block manager */
cmd->bm = dm_block_manager_create(cmd->bdev,
DM_CLONE_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
DM_CLONE_MAX_CONCURRENT_LOCKS);
if (IS_ERR(cmd->bm)) {
DMERR("Failed to create block manager");
return PTR_ERR(cmd->bm);
}
r = __open_or_format_metadata(cmd, may_format_device);
if (r)
dm_block_manager_destroy(cmd->bm);
return r;
}
static void __destroy_persistent_data_structures(struct dm_clone_metadata *cmd)
{
dm_sm_destroy(cmd->sm);
dm_tm_destroy(cmd->tm);
dm_block_manager_destroy(cmd->bm);
}
/*---------------------------------------------------------------------------*/
static size_t bitmap_size(unsigned long nr_bits)
{
return BITS_TO_LONGS(nr_bits) * sizeof(long);
}
static int __dirty_map_init(struct dirty_map *dmap, unsigned long nr_words,
unsigned long nr_regions)
{
dmap->changed = 0;
dmap->dirty_words = kvzalloc(bitmap_size(nr_words), GFP_KERNEL);
if (!dmap->dirty_words)
return -ENOMEM;
dmap->dirty_regions = kvzalloc(bitmap_size(nr_regions), GFP_KERNEL);
if (!dmap->dirty_regions) {
kvfree(dmap->dirty_words);
return -ENOMEM;
}
return 0;
}
static void __dirty_map_exit(struct dirty_map *dmap)
{
kvfree(dmap->dirty_words);
kvfree(dmap->dirty_regions);
}
static int dirty_map_init(struct dm_clone_metadata *cmd)
{
if (__dirty_map_init(&cmd->dmap[0], cmd->nr_words, cmd->nr_regions)) {
DMERR("Failed to allocate dirty bitmap");
return -ENOMEM;
}
if (__dirty_map_init(&cmd->dmap[1], cmd->nr_words, cmd->nr_regions)) {
DMERR("Failed to allocate dirty bitmap");
__dirty_map_exit(&cmd->dmap[0]);
return -ENOMEM;
}
cmd->current_dmap = &cmd->dmap[0];
cmd->committing_dmap = NULL;
return 0;
}
static void dirty_map_exit(struct dm_clone_metadata *cmd)
{
__dirty_map_exit(&cmd->dmap[0]);
__dirty_map_exit(&cmd->dmap[1]);
}
static int __load_bitset_in_core(struct dm_clone_metadata *cmd)
{
int r;
unsigned long i;
struct dm_bitset_cursor c;
/* Flush bitset cache */
r = dm_bitset_flush(&cmd->bitset_info, cmd->bitset_root, &cmd->bitset_root);
if (r)
return r;
r = dm_bitset_cursor_begin(&cmd->bitset_info, cmd->bitset_root, cmd->nr_regions, &c);
if (r)
return r;
for (i = 0; ; i++) {
if (dm_bitset_cursor_get_value(&c))
__set_bit(i, cmd->region_map);
else
__clear_bit(i, cmd->region_map);
if (i >= (cmd->nr_regions - 1))
break;
r = dm_bitset_cursor_next(&c);
if (r)
break;
}
dm_bitset_cursor_end(&c);
return r;
}
struct dm_clone_metadata *dm_clone_metadata_open(struct block_device *bdev,
sector_t target_size,
sector_t region_size)
{
int r;
struct dm_clone_metadata *cmd;
cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
if (!cmd) {
DMERR("Failed to allocate memory for dm-clone metadata");
return ERR_PTR(-ENOMEM);
}
cmd->bdev = bdev;
cmd->target_size = target_size;
cmd->region_size = region_size;
cmd->nr_regions = dm_sector_div_up(cmd->target_size, cmd->region_size);
cmd->nr_words = BITS_TO_LONGS(cmd->nr_regions);
init_rwsem(&cmd->lock);
spin_lock_init(&cmd->bitmap_lock);
cmd->read_only = 0;
cmd->fail_io = false;
cmd->hydration_done = false;
cmd->region_map = kvmalloc(bitmap_size(cmd->nr_regions), GFP_KERNEL);
if (!cmd->region_map) {
DMERR("Failed to allocate memory for region bitmap");
r = -ENOMEM;
goto out_with_md;
}
r = __create_persistent_data_structures(cmd, true);
if (r)
goto out_with_region_map;
r = __load_bitset_in_core(cmd);
if (r) {
DMERR("Failed to load on-disk region map");
goto out_with_pds;
}
r = dirty_map_init(cmd);
if (r)
goto out_with_pds;
if (bitmap_full(cmd->region_map, cmd->nr_regions))
cmd->hydration_done = true;
return cmd;
out_with_pds:
__destroy_persistent_data_structures(cmd);
out_with_region_map:
kvfree(cmd->region_map);
out_with_md:
kfree(cmd);
return ERR_PTR(r);
}
void dm_clone_metadata_close(struct dm_clone_metadata *cmd)
{
if (!cmd->fail_io)
__destroy_persistent_data_structures(cmd);
dirty_map_exit(cmd);
kvfree(cmd->region_map);
kfree(cmd);
}
bool dm_clone_is_hydration_done(struct dm_clone_metadata *cmd)
{
return cmd->hydration_done;
}
bool dm_clone_is_region_hydrated(struct dm_clone_metadata *cmd, unsigned long region_nr)
{
return dm_clone_is_hydration_done(cmd) || test_bit(region_nr, cmd->region_map);
}
bool dm_clone_is_range_hydrated(struct dm_clone_metadata *cmd,
unsigned long start, unsigned long nr_regions)
{
unsigned long bit;
if (dm_clone_is_hydration_done(cmd))
return true;
bit = find_next_zero_bit(cmd->region_map, cmd->nr_regions, start);
return (bit >= (start + nr_regions));
}
unsigned int dm_clone_nr_of_hydrated_regions(struct dm_clone_metadata *cmd)
{
return bitmap_weight(cmd->region_map, cmd->nr_regions);
}
unsigned long dm_clone_find_next_unhydrated_region(struct dm_clone_metadata *cmd,
unsigned long start)
{
return find_next_zero_bit(cmd->region_map, cmd->nr_regions, start);
}
static int __update_metadata_word(struct dm_clone_metadata *cmd,
unsigned long *dirty_regions,
unsigned long word)
{
int r;
unsigned long index = word * BITS_PER_LONG;
unsigned long max_index = min(cmd->nr_regions, (word + 1) * BITS_PER_LONG);
while (index < max_index) {
if (test_bit(index, dirty_regions)) {
r = dm_bitset_set_bit(&cmd->bitset_info, cmd->bitset_root,
index, &cmd->bitset_root);
if (r) {
DMERR("dm_bitset_set_bit failed");
return r;
}
__clear_bit(index, dirty_regions);
}
index++;
}
return 0;
}
static int __metadata_commit(struct dm_clone_metadata *cmd)
{
int r;
struct dm_block *sblock;
struct superblock_disk *sb;
/* Flush bitset cache */
r = dm_bitset_flush(&cmd->bitset_info, cmd->bitset_root, &cmd->bitset_root);
if (r) {
DMERR("dm_bitset_flush failed");
return r;
}
/* Flush to disk all blocks, except the superblock */
r = dm_tm_pre_commit(cmd->tm);
if (r) {
DMERR("dm_tm_pre_commit failed");
return r;
}
/* Save the space map root in cmd->metadata_space_map_root */
r = __copy_sm_root(cmd);
if (r) {
DMERR("__copy_sm_root failed");
return r;
}
/* Lock the superblock */
r = superblock_write_lock_zero(cmd, &sblock);
if (r) {
DMERR("Failed to write_lock superblock");
return r;
}
/* Save the metadata in superblock */
sb = dm_block_data(sblock);
__prepare_superblock(cmd, sb);
/* Unlock superblock and commit it to disk */
r = dm_tm_commit(cmd->tm, sblock);
if (r) {
DMERR("Failed to commit superblock");
return r;
}
/*
* FIXME: Find a more efficient way to check if the hydration is done.
*/
if (bitmap_full(cmd->region_map, cmd->nr_regions))
cmd->hydration_done = true;
return 0;
}
static int __flush_dmap(struct dm_clone_metadata *cmd, struct dirty_map *dmap)
{
int r;
unsigned long word;
word = 0;
do {
word = find_next_bit(dmap->dirty_words, cmd->nr_words, word);
if (word == cmd->nr_words)
break;
r = __update_metadata_word(cmd, dmap->dirty_regions, word);
if (r)
return r;
__clear_bit(word, dmap->dirty_words);
word++;
} while (word < cmd->nr_words);
r = __metadata_commit(cmd);
if (r)
return r;
/* Update the changed flag */
spin_lock_irq(&cmd->bitmap_lock);
dmap->changed = 0;
spin_unlock_irq(&cmd->bitmap_lock);
return 0;
}
int dm_clone_metadata_pre_commit(struct dm_clone_metadata *cmd)
{
int r = 0;
struct dirty_map *dmap, *next_dmap;
down_write(&cmd->lock);
if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) {
r = -EPERM;
goto out;
}
/* Get current dirty bitmap */
dmap = cmd->current_dmap;
/* Get next dirty bitmap */
next_dmap = (dmap == &cmd->dmap[0]) ? &cmd->dmap[1] : &cmd->dmap[0];
/*
* The last commit failed, so we don't have a clean dirty-bitmap to
* use.
*/
if (WARN_ON(next_dmap->changed || cmd->committing_dmap)) {
r = -EINVAL;
goto out;
}
/* Swap dirty bitmaps */
spin_lock_irq(&cmd->bitmap_lock);
cmd->current_dmap = next_dmap;
spin_unlock_irq(&cmd->bitmap_lock);
/* Set old dirty bitmap as currently committing */
cmd->committing_dmap = dmap;
out:
up_write(&cmd->lock);
return r;
}
int dm_clone_metadata_commit(struct dm_clone_metadata *cmd)
{
int r = -EPERM;
down_write(&cmd->lock);
if (cmd->fail_io || dm_bm_is_read_only(cmd->bm))
goto out;
if (WARN_ON(!cmd->committing_dmap)) {
r = -EINVAL;
goto out;
}
r = __flush_dmap(cmd, cmd->committing_dmap);
if (!r) {
/* Clear committing dmap */
cmd->committing_dmap = NULL;
}
out:
up_write(&cmd->lock);
return r;
}
int dm_clone_set_region_hydrated(struct dm_clone_metadata *cmd, unsigned long region_nr)
{
int r = 0;
struct dirty_map *dmap;
unsigned long word, flags;
if (unlikely(region_nr >= cmd->nr_regions)) {
DMERR("Region %lu out of range (total number of regions %lu)",
region_nr, cmd->nr_regions);
return -ERANGE;
}
word = region_nr / BITS_PER_LONG;
spin_lock_irqsave(&cmd->bitmap_lock, flags);
if (cmd->read_only) {
r = -EPERM;
goto out;
}
dmap = cmd->current_dmap;
__set_bit(word, dmap->dirty_words);
__set_bit(region_nr, dmap->dirty_regions);
__set_bit(region_nr, cmd->region_map);
dmap->changed = 1;
out:
spin_unlock_irqrestore(&cmd->bitmap_lock, flags);
return r;
}
int dm_clone_cond_set_range(struct dm_clone_metadata *cmd, unsigned long start,
unsigned long nr_regions)
{
int r = 0;
struct dirty_map *dmap;
unsigned long word, region_nr;
if (unlikely(start >= cmd->nr_regions || (start + nr_regions) < start ||
(start + nr_regions) > cmd->nr_regions)) {
DMERR("Invalid region range: start %lu, nr_regions %lu (total number of regions %lu)",
start, nr_regions, cmd->nr_regions);
return -ERANGE;
}
spin_lock_irq(&cmd->bitmap_lock);
if (cmd->read_only) {
r = -EPERM;
goto out;
}
dmap = cmd->current_dmap;
for (region_nr = start; region_nr < (start + nr_regions); region_nr++) {
if (!test_bit(region_nr, cmd->region_map)) {
word = region_nr / BITS_PER_LONG;
__set_bit(word, dmap->dirty_words);
__set_bit(region_nr, dmap->dirty_regions);
__set_bit(region_nr, cmd->region_map);
dmap->changed = 1;
}
}
out:
spin_unlock_irq(&cmd->bitmap_lock);
return r;
}
/*
* WARNING: This must not be called concurrently with either
* dm_clone_set_region_hydrated() or dm_clone_cond_set_range(), as it changes
* cmd->region_map without taking the cmd->bitmap_lock spinlock. The only
* exception is after setting the metadata to read-only mode, using
* dm_clone_metadata_set_read_only().
*
* We don't take the spinlock because __load_bitset_in_core() does I/O, so it
* may block.
*/
int dm_clone_reload_in_core_bitset(struct dm_clone_metadata *cmd)
{
int r = -EINVAL;
down_write(&cmd->lock);
if (cmd->fail_io)
goto out;
r = __load_bitset_in_core(cmd);
out:
up_write(&cmd->lock);
return r;
}
bool dm_clone_changed_this_transaction(struct dm_clone_metadata *cmd)
{
bool r;
unsigned long flags;
spin_lock_irqsave(&cmd->bitmap_lock, flags);
r = cmd->dmap[0].changed || cmd->dmap[1].changed;
spin_unlock_irqrestore(&cmd->bitmap_lock, flags);
return r;
}
int dm_clone_metadata_abort(struct dm_clone_metadata *cmd)
{
int r = -EPERM;
down_write(&cmd->lock);
if (cmd->fail_io || dm_bm_is_read_only(cmd->bm))
goto out;
__destroy_persistent_data_structures(cmd);
r = __create_persistent_data_structures(cmd, false);
if (r) {
/* If something went wrong we can neither write nor read the metadata */
cmd->fail_io = true;
}
out:
up_write(&cmd->lock);
return r;
}
void dm_clone_metadata_set_read_only(struct dm_clone_metadata *cmd)
{
down_write(&cmd->lock);
spin_lock_irq(&cmd->bitmap_lock);
cmd->read_only = 1;
spin_unlock_irq(&cmd->bitmap_lock);
if (!cmd->fail_io)
dm_bm_set_read_only(cmd->bm);
up_write(&cmd->lock);
}
void dm_clone_metadata_set_read_write(struct dm_clone_metadata *cmd)
{
down_write(&cmd->lock);
spin_lock_irq(&cmd->bitmap_lock);
cmd->read_only = 0;
spin_unlock_irq(&cmd->bitmap_lock);
if (!cmd->fail_io)
dm_bm_set_read_write(cmd->bm);
up_write(&cmd->lock);
}
int dm_clone_get_free_metadata_block_count(struct dm_clone_metadata *cmd,
dm_block_t *result)
{
int r = -EINVAL;
down_read(&cmd->lock);
if (!cmd->fail_io)
r = dm_sm_get_nr_free(cmd->sm, result);
up_read(&cmd->lock);
return r;
}
int dm_clone_get_metadata_dev_size(struct dm_clone_metadata *cmd,
dm_block_t *result)
{
int r = -EINVAL;
down_read(&cmd->lock);
if (!cmd->fail_io)
r = dm_sm_get_nr_blocks(cmd->sm, result);
up_read(&cmd->lock);
return r;
}
| linux-master | drivers/md/dm-clone-metadata.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012-2017 Red Hat, Inc.
*
* This file is released under the GPL.
*/
#include "dm.h"
#include "dm-bio-prison-v2.h"
#include <linux/spinlock.h>
#include <linux/mempool.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/rwsem.h>
/*----------------------------------------------------------------*/
#define MIN_CELLS 1024
struct dm_bio_prison_v2 {
struct workqueue_struct *wq;
spinlock_t lock;
struct rb_root cells;
mempool_t cell_pool;
};
static struct kmem_cache *_cell_cache;
/*----------------------------------------------------------------*/
/*
* @nr_cells should be the number of cells you want in use _concurrently_.
* Don't confuse it with the number of distinct keys.
*/
struct dm_bio_prison_v2 *dm_bio_prison_create_v2(struct workqueue_struct *wq)
{
struct dm_bio_prison_v2 *prison = kzalloc(sizeof(*prison), GFP_KERNEL);
int ret;
if (!prison)
return NULL;
prison->wq = wq;
spin_lock_init(&prison->lock);
ret = mempool_init_slab_pool(&prison->cell_pool, MIN_CELLS, _cell_cache);
if (ret) {
kfree(prison);
return NULL;
}
prison->cells = RB_ROOT;
return prison;
}
EXPORT_SYMBOL_GPL(dm_bio_prison_create_v2);
void dm_bio_prison_destroy_v2(struct dm_bio_prison_v2 *prison)
{
mempool_exit(&prison->cell_pool);
kfree(prison);
}
EXPORT_SYMBOL_GPL(dm_bio_prison_destroy_v2);
struct dm_bio_prison_cell_v2 *dm_bio_prison_alloc_cell_v2(struct dm_bio_prison_v2 *prison, gfp_t gfp)
{
return mempool_alloc(&prison->cell_pool, gfp);
}
EXPORT_SYMBOL_GPL(dm_bio_prison_alloc_cell_v2);
void dm_bio_prison_free_cell_v2(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell)
{
mempool_free(cell, &prison->cell_pool);
}
EXPORT_SYMBOL_GPL(dm_bio_prison_free_cell_v2);
static void __setup_new_cell(struct dm_cell_key_v2 *key,
struct dm_bio_prison_cell_v2 *cell)
{
memset(cell, 0, sizeof(*cell));
memcpy(&cell->key, key, sizeof(cell->key));
bio_list_init(&cell->bios);
}
static int cmp_keys(struct dm_cell_key_v2 *lhs,
struct dm_cell_key_v2 *rhs)
{
if (lhs->virtual < rhs->virtual)
return -1;
if (lhs->virtual > rhs->virtual)
return 1;
if (lhs->dev < rhs->dev)
return -1;
if (lhs->dev > rhs->dev)
return 1;
if (lhs->block_end <= rhs->block_begin)
return -1;
if (lhs->block_begin >= rhs->block_end)
return 1;
return 0;
}
/*
* Returns true if node found, otherwise it inserts a new one.
*/
static bool __find_or_insert(struct dm_bio_prison_v2 *prison,
struct dm_cell_key_v2 *key,
struct dm_bio_prison_cell_v2 *cell_prealloc,
struct dm_bio_prison_cell_v2 **result)
{
int r;
struct rb_node **new = &prison->cells.rb_node, *parent = NULL;
while (*new) {
struct dm_bio_prison_cell_v2 *cell =
rb_entry(*new, struct dm_bio_prison_cell_v2, node);
r = cmp_keys(key, &cell->key);
parent = *new;
if (r < 0)
new = &((*new)->rb_left);
else if (r > 0)
new = &((*new)->rb_right);
else {
*result = cell;
return true;
}
}
__setup_new_cell(key, cell_prealloc);
*result = cell_prealloc;
rb_link_node(&cell_prealloc->node, parent, new);
rb_insert_color(&cell_prealloc->node, &prison->cells);
return false;
}
static bool __get(struct dm_bio_prison_v2 *prison,
struct dm_cell_key_v2 *key,
unsigned int lock_level,
struct bio *inmate,
struct dm_bio_prison_cell_v2 *cell_prealloc,
struct dm_bio_prison_cell_v2 **cell)
{
if (__find_or_insert(prison, key, cell_prealloc, cell)) {
if ((*cell)->exclusive_lock) {
if (lock_level <= (*cell)->exclusive_level) {
bio_list_add(&(*cell)->bios, inmate);
return false;
}
}
(*cell)->shared_count++;
} else
(*cell)->shared_count = 1;
return true;
}
bool dm_cell_get_v2(struct dm_bio_prison_v2 *prison,
struct dm_cell_key_v2 *key,
unsigned int lock_level,
struct bio *inmate,
struct dm_bio_prison_cell_v2 *cell_prealloc,
struct dm_bio_prison_cell_v2 **cell_result)
{
int r;
spin_lock_irq(&prison->lock);
r = __get(prison, key, lock_level, inmate, cell_prealloc, cell_result);
spin_unlock_irq(&prison->lock);
return r;
}
EXPORT_SYMBOL_GPL(dm_cell_get_v2);
static bool __put(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell)
{
BUG_ON(!cell->shared_count);
cell->shared_count--;
// FIXME: shared locks granted above the lock level could starve this
if (!cell->shared_count) {
if (cell->exclusive_lock) {
if (cell->quiesce_continuation) {
queue_work(prison->wq, cell->quiesce_continuation);
cell->quiesce_continuation = NULL;
}
} else {
rb_erase(&cell->node, &prison->cells);
return true;
}
}
return false;
}
bool dm_cell_put_v2(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell)
{
bool r;
unsigned long flags;
spin_lock_irqsave(&prison->lock, flags);
r = __put(prison, cell);
spin_unlock_irqrestore(&prison->lock, flags);
return r;
}
EXPORT_SYMBOL_GPL(dm_cell_put_v2);
static int __lock(struct dm_bio_prison_v2 *prison,
struct dm_cell_key_v2 *key,
unsigned int lock_level,
struct dm_bio_prison_cell_v2 *cell_prealloc,
struct dm_bio_prison_cell_v2 **cell_result)
{
struct dm_bio_prison_cell_v2 *cell;
if (__find_or_insert(prison, key, cell_prealloc, &cell)) {
if (cell->exclusive_lock)
return -EBUSY;
cell->exclusive_lock = true;
cell->exclusive_level = lock_level;
*cell_result = cell;
// FIXME: we don't yet know what level these shared locks
// were taken at, so have to quiesce them all.
return cell->shared_count > 0;
} else {
cell = cell_prealloc;
cell->shared_count = 0;
cell->exclusive_lock = true;
cell->exclusive_level = lock_level;
*cell_result = cell;
}
return 0;
}
int dm_cell_lock_v2(struct dm_bio_prison_v2 *prison,
struct dm_cell_key_v2 *key,
unsigned int lock_level,
struct dm_bio_prison_cell_v2 *cell_prealloc,
struct dm_bio_prison_cell_v2 **cell_result)
{
int r;
spin_lock_irq(&prison->lock);
r = __lock(prison, key, lock_level, cell_prealloc, cell_result);
spin_unlock_irq(&prison->lock);
return r;
}
EXPORT_SYMBOL_GPL(dm_cell_lock_v2);
static void __quiesce(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell,
struct work_struct *continuation)
{
if (!cell->shared_count)
queue_work(prison->wq, continuation);
else
cell->quiesce_continuation = continuation;
}
void dm_cell_quiesce_v2(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell,
struct work_struct *continuation)
{
spin_lock_irq(&prison->lock);
__quiesce(prison, cell, continuation);
spin_unlock_irq(&prison->lock);
}
EXPORT_SYMBOL_GPL(dm_cell_quiesce_v2);
static int __promote(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell,
unsigned int new_lock_level)
{
if (!cell->exclusive_lock)
return -EINVAL;
cell->exclusive_level = new_lock_level;
return cell->shared_count > 0;
}
int dm_cell_lock_promote_v2(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell,
unsigned int new_lock_level)
{
int r;
spin_lock_irq(&prison->lock);
r = __promote(prison, cell, new_lock_level);
spin_unlock_irq(&prison->lock);
return r;
}
EXPORT_SYMBOL_GPL(dm_cell_lock_promote_v2);
static bool __unlock(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell,
struct bio_list *bios)
{
BUG_ON(!cell->exclusive_lock);
bio_list_merge(bios, &cell->bios);
bio_list_init(&cell->bios);
if (cell->shared_count) {
cell->exclusive_lock = false;
return false;
}
rb_erase(&cell->node, &prison->cells);
return true;
}
bool dm_cell_unlock_v2(struct dm_bio_prison_v2 *prison,
struct dm_bio_prison_cell_v2 *cell,
struct bio_list *bios)
{
bool r;
spin_lock_irq(&prison->lock);
r = __unlock(prison, cell, bios);
spin_unlock_irq(&prison->lock);
return r;
}
EXPORT_SYMBOL_GPL(dm_cell_unlock_v2);
/*----------------------------------------------------------------*/
int __init dm_bio_prison_init_v2(void)
{
_cell_cache = KMEM_CACHE(dm_bio_prison_cell_v2, 0);
if (!_cell_cache)
return -ENOMEM;
return 0;
}
void dm_bio_prison_exit_v2(void)
{
kmem_cache_destroy(_cell_cache);
_cell_cache = NULL;
}
| linux-master | drivers/md/dm-bio-prison-v2.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2020 Oracle Corporation
*
* Module Author: Mike Christie
*/
#include "dm-path-selector.h"
#include <linux/device-mapper.h>
#include <linux/module.h>
#define DM_MSG_PREFIX "multipath io-affinity"
struct path_info {
struct dm_path *path;
cpumask_var_t cpumask;
refcount_t refcount;
bool failed;
};
struct selector {
struct path_info **path_map;
cpumask_var_t path_mask;
atomic_t map_misses;
};
static void ioa_free_path(struct selector *s, unsigned int cpu)
{
struct path_info *pi = s->path_map[cpu];
if (!pi)
return;
if (refcount_dec_and_test(&pi->refcount)) {
cpumask_clear_cpu(cpu, s->path_mask);
free_cpumask_var(pi->cpumask);
kfree(pi);
s->path_map[cpu] = NULL;
}
}
static int ioa_add_path(struct path_selector *ps, struct dm_path *path,
int argc, char **argv, char **error)
{
struct selector *s = ps->context;
struct path_info *pi = NULL;
unsigned int cpu;
int ret;
if (argc != 1) {
*error = "io-affinity ps: invalid number of arguments";
return -EINVAL;
}
pi = kzalloc(sizeof(*pi), GFP_KERNEL);
if (!pi) {
*error = "io-affinity ps: Error allocating path context";
return -ENOMEM;
}
pi->path = path;
path->pscontext = pi;
refcount_set(&pi->refcount, 1);
if (!zalloc_cpumask_var(&pi->cpumask, GFP_KERNEL)) {
*error = "io-affinity ps: Error allocating cpumask context";
ret = -ENOMEM;
goto free_pi;
}
ret = cpumask_parse(argv[0], pi->cpumask);
if (ret) {
*error = "io-affinity ps: invalid cpumask";
ret = -EINVAL;
goto free_mask;
}
for_each_cpu(cpu, pi->cpumask) {
if (cpu >= nr_cpu_ids) {
DMWARN_LIMIT("Ignoring mapping for CPU %u. Max CPU is %u",
cpu, nr_cpu_ids);
break;
}
if (s->path_map[cpu]) {
DMWARN("CPU mapping for %u exists. Ignoring.", cpu);
continue;
}
cpumask_set_cpu(cpu, s->path_mask);
s->path_map[cpu] = pi;
refcount_inc(&pi->refcount);
}
if (refcount_dec_and_test(&pi->refcount)) {
*error = "io-affinity ps: No new/valid CPU mapping found";
ret = -EINVAL;
goto free_mask;
}
return 0;
free_mask:
free_cpumask_var(pi->cpumask);
free_pi:
kfree(pi);
return ret;
}
static int ioa_create(struct path_selector *ps, unsigned int argc, char **argv)
{
struct selector *s;
s = kmalloc(sizeof(*s), GFP_KERNEL);
if (!s)
return -ENOMEM;
s->path_map = kzalloc(nr_cpu_ids * sizeof(struct path_info *),
GFP_KERNEL);
if (!s->path_map)
goto free_selector;
if (!zalloc_cpumask_var(&s->path_mask, GFP_KERNEL))
goto free_map;
atomic_set(&s->map_misses, 0);
ps->context = s;
return 0;
free_map:
kfree(s->path_map);
free_selector:
kfree(s);
return -ENOMEM;
}
static void ioa_destroy(struct path_selector *ps)
{
struct selector *s = ps->context;
unsigned int cpu;
for_each_cpu(cpu, s->path_mask)
ioa_free_path(s, cpu);
free_cpumask_var(s->path_mask);
kfree(s->path_map);
kfree(s);
ps->context = NULL;
}
static int ioa_status(struct path_selector *ps, struct dm_path *path,
status_type_t type, char *result, unsigned int maxlen)
{
struct selector *s = ps->context;
struct path_info *pi;
int sz = 0;
if (!path) {
DMEMIT("0 ");
return sz;
}
switch (type) {
case STATUSTYPE_INFO:
DMEMIT("%d ", atomic_read(&s->map_misses));
break;
case STATUSTYPE_TABLE:
pi = path->pscontext;
DMEMIT("%*pb ", cpumask_pr_args(pi->cpumask));
break;
case STATUSTYPE_IMA:
*result = '\0';
break;
}
return sz;
}
static void ioa_fail_path(struct path_selector *ps, struct dm_path *p)
{
struct path_info *pi = p->pscontext;
pi->failed = true;
}
static int ioa_reinstate_path(struct path_selector *ps, struct dm_path *p)
{
struct path_info *pi = p->pscontext;
pi->failed = false;
return 0;
}
static struct dm_path *ioa_select_path(struct path_selector *ps,
size_t nr_bytes)
{
unsigned int cpu, node;
struct selector *s = ps->context;
const struct cpumask *cpumask;
struct path_info *pi;
int i;
cpu = get_cpu();
pi = s->path_map[cpu];
if (pi && !pi->failed)
goto done;
/*
* Perf is not optimal, but we at least try the local node then just
* try not to fail.
*/
if (!pi)
atomic_inc(&s->map_misses);
node = cpu_to_node(cpu);
cpumask = cpumask_of_node(node);
for_each_cpu(i, cpumask) {
pi = s->path_map[i];
if (pi && !pi->failed)
goto done;
}
for_each_cpu(i, s->path_mask) {
pi = s->path_map[i];
if (pi && !pi->failed)
goto done;
}
pi = NULL;
done:
put_cpu();
return pi ? pi->path : NULL;
}
static struct path_selector_type ioa_ps = {
.name = "io-affinity",
.module = THIS_MODULE,
.table_args = 1,
.info_args = 1,
.create = ioa_create,
.destroy = ioa_destroy,
.status = ioa_status,
.add_path = ioa_add_path,
.fail_path = ioa_fail_path,
.reinstate_path = ioa_reinstate_path,
.select_path = ioa_select_path,
};
static int __init dm_ioa_init(void)
{
int ret = dm_register_path_selector(&ioa_ps);
if (ret < 0)
DMERR("register failed %d", ret);
return ret;
}
static void __exit dm_ioa_exit(void)
{
int ret = dm_unregister_path_selector(&ioa_ps);
if (ret < 0)
DMERR("unregister failed %d", ret);
}
module_init(dm_ioa_init);
module_exit(dm_ioa_exit);
MODULE_DESCRIPTION(DM_NAME " multipath path selector that selects paths based on the CPU IO is being executed on");
MODULE_AUTHOR("Mike Christie <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-ps-io-affinity.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2010-2012 by Dell Inc. All rights reserved.
* Copyright (C) 2011-2013 Red Hat, Inc.
*
* This file is released under the GPL.
*
* dm-switch is a device-mapper target that maps IO to underlying block
* devices efficiently when there are a large number of fixed-sized
* address regions but there is no simple pattern to allow for a compact
* mapping representation such as dm-stripe.
*/
#include <linux/device-mapper.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/vmalloc.h>
#define DM_MSG_PREFIX "switch"
/*
* One region_table_slot_t holds <region_entries_per_slot> region table
* entries each of which is <region_table_entry_bits> in size.
*/
typedef unsigned long region_table_slot_t;
/*
* A device with the offset to its start sector.
*/
struct switch_path {
struct dm_dev *dmdev;
sector_t start;
};
/*
* Context block for a dm switch device.
*/
struct switch_ctx {
struct dm_target *ti;
unsigned int nr_paths; /* Number of paths in path_list. */
unsigned int region_size; /* Region size in 512-byte sectors */
unsigned long nr_regions; /* Number of regions making up the device */
signed char region_size_bits; /* log2 of region_size or -1 */
unsigned char region_table_entry_bits; /* Number of bits in one region table entry */
unsigned char region_entries_per_slot; /* Number of entries in one region table slot */
signed char region_entries_per_slot_bits; /* log2 of region_entries_per_slot or -1 */
region_table_slot_t *region_table; /* Region table */
/*
* Array of dm devices to switch between.
*/
struct switch_path path_list[];
};
static struct switch_ctx *alloc_switch_ctx(struct dm_target *ti, unsigned int nr_paths,
unsigned int region_size)
{
struct switch_ctx *sctx;
sctx = kzalloc(struct_size(sctx, path_list, nr_paths), GFP_KERNEL);
if (!sctx)
return NULL;
sctx->ti = ti;
sctx->region_size = region_size;
ti->private = sctx;
return sctx;
}
static int alloc_region_table(struct dm_target *ti, unsigned int nr_paths)
{
struct switch_ctx *sctx = ti->private;
sector_t nr_regions = ti->len;
sector_t nr_slots;
if (!(sctx->region_size & (sctx->region_size - 1)))
sctx->region_size_bits = __ffs(sctx->region_size);
else
sctx->region_size_bits = -1;
sctx->region_table_entry_bits = 1;
while (sctx->region_table_entry_bits < sizeof(region_table_slot_t) * 8 &&
(region_table_slot_t)1 << sctx->region_table_entry_bits < nr_paths)
sctx->region_table_entry_bits++;
sctx->region_entries_per_slot = (sizeof(region_table_slot_t) * 8) / sctx->region_table_entry_bits;
if (!(sctx->region_entries_per_slot & (sctx->region_entries_per_slot - 1)))
sctx->region_entries_per_slot_bits = __ffs(sctx->region_entries_per_slot);
else
sctx->region_entries_per_slot_bits = -1;
if (sector_div(nr_regions, sctx->region_size))
nr_regions++;
if (nr_regions >= ULONG_MAX) {
ti->error = "Region table too large";
return -EINVAL;
}
sctx->nr_regions = nr_regions;
nr_slots = nr_regions;
if (sector_div(nr_slots, sctx->region_entries_per_slot))
nr_slots++;
if (nr_slots > ULONG_MAX / sizeof(region_table_slot_t)) {
ti->error = "Region table too large";
return -EINVAL;
}
sctx->region_table = vmalloc(array_size(nr_slots,
sizeof(region_table_slot_t)));
if (!sctx->region_table) {
ti->error = "Cannot allocate region table";
return -ENOMEM;
}
return 0;
}
static void switch_get_position(struct switch_ctx *sctx, unsigned long region_nr,
unsigned long *region_index, unsigned int *bit)
{
if (sctx->region_entries_per_slot_bits >= 0) {
*region_index = region_nr >> sctx->region_entries_per_slot_bits;
*bit = region_nr & (sctx->region_entries_per_slot - 1);
} else {
*region_index = region_nr / sctx->region_entries_per_slot;
*bit = region_nr % sctx->region_entries_per_slot;
}
*bit *= sctx->region_table_entry_bits;
}
static unsigned int switch_region_table_read(struct switch_ctx *sctx, unsigned long region_nr)
{
unsigned long region_index;
unsigned int bit;
switch_get_position(sctx, region_nr, ®ion_index, &bit);
return (READ_ONCE(sctx->region_table[region_index]) >> bit) &
((1 << sctx->region_table_entry_bits) - 1);
}
/*
* Find which path to use at given offset.
*/
static unsigned int switch_get_path_nr(struct switch_ctx *sctx, sector_t offset)
{
unsigned int path_nr;
sector_t p;
p = offset;
if (sctx->region_size_bits >= 0)
p >>= sctx->region_size_bits;
else
sector_div(p, sctx->region_size);
path_nr = switch_region_table_read(sctx, p);
/* This can only happen if the processor uses non-atomic stores. */
if (unlikely(path_nr >= sctx->nr_paths))
path_nr = 0;
return path_nr;
}
static void switch_region_table_write(struct switch_ctx *sctx, unsigned long region_nr,
unsigned int value)
{
unsigned long region_index;
unsigned int bit;
region_table_slot_t pte;
switch_get_position(sctx, region_nr, ®ion_index, &bit);
pte = sctx->region_table[region_index];
pte &= ~((((region_table_slot_t)1 << sctx->region_table_entry_bits) - 1) << bit);
pte |= (region_table_slot_t)value << bit;
sctx->region_table[region_index] = pte;
}
/*
* Fill the region table with an initial round robin pattern.
*/
static void initialise_region_table(struct switch_ctx *sctx)
{
unsigned int path_nr = 0;
unsigned long region_nr;
for (region_nr = 0; region_nr < sctx->nr_regions; region_nr++) {
switch_region_table_write(sctx, region_nr, path_nr);
if (++path_nr >= sctx->nr_paths)
path_nr = 0;
}
}
static int parse_path(struct dm_arg_set *as, struct dm_target *ti)
{
struct switch_ctx *sctx = ti->private;
unsigned long long start;
int r;
r = dm_get_device(ti, dm_shift_arg(as), dm_table_get_mode(ti->table),
&sctx->path_list[sctx->nr_paths].dmdev);
if (r) {
ti->error = "Device lookup failed";
return r;
}
if (kstrtoull(dm_shift_arg(as), 10, &start) || start != (sector_t)start) {
ti->error = "Invalid device starting offset";
dm_put_device(ti, sctx->path_list[sctx->nr_paths].dmdev);
return -EINVAL;
}
sctx->path_list[sctx->nr_paths].start = start;
sctx->nr_paths++;
return 0;
}
/*
* Destructor: Don't free the dm_target, just the ti->private data (if any).
*/
static void switch_dtr(struct dm_target *ti)
{
struct switch_ctx *sctx = ti->private;
while (sctx->nr_paths--)
dm_put_device(ti, sctx->path_list[sctx->nr_paths].dmdev);
vfree(sctx->region_table);
kfree(sctx);
}
/*
* Constructor arguments:
* <num_paths> <region_size> <num_optional_args> [<optional_args>...]
* [<dev_path> <offset>]+
*
* Optional args are to allow for future extension: currently this
* parameter must be 0.
*/
static int switch_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
static const struct dm_arg _args[] = {
{1, (KMALLOC_MAX_SIZE - sizeof(struct switch_ctx)) / sizeof(struct switch_path), "Invalid number of paths"},
{1, UINT_MAX, "Invalid region size"},
{0, 0, "Invalid number of optional args"},
};
struct switch_ctx *sctx;
struct dm_arg_set as;
unsigned int nr_paths, region_size, nr_optional_args;
int r;
as.argc = argc;
as.argv = argv;
r = dm_read_arg(_args, &as, &nr_paths, &ti->error);
if (r)
return -EINVAL;
r = dm_read_arg(_args + 1, &as, ®ion_size, &ti->error);
if (r)
return r;
r = dm_read_arg_group(_args + 2, &as, &nr_optional_args, &ti->error);
if (r)
return r;
/* parse optional arguments here, if we add any */
if (as.argc != nr_paths * 2) {
ti->error = "Incorrect number of path arguments";
return -EINVAL;
}
sctx = alloc_switch_ctx(ti, nr_paths, region_size);
if (!sctx) {
ti->error = "Cannot allocate redirection context";
return -ENOMEM;
}
r = dm_set_target_max_io_len(ti, region_size);
if (r)
goto error;
while (as.argc) {
r = parse_path(&as, ti);
if (r)
goto error;
}
r = alloc_region_table(ti, nr_paths);
if (r)
goto error;
initialise_region_table(sctx);
/* For UNMAP, sending the request down any path is sufficient */
ti->num_discard_bios = 1;
return 0;
error:
switch_dtr(ti);
return r;
}
static int switch_map(struct dm_target *ti, struct bio *bio)
{
struct switch_ctx *sctx = ti->private;
sector_t offset = dm_target_offset(ti, bio->bi_iter.bi_sector);
unsigned int path_nr = switch_get_path_nr(sctx, offset);
bio_set_dev(bio, sctx->path_list[path_nr].dmdev->bdev);
bio->bi_iter.bi_sector = sctx->path_list[path_nr].start + offset;
return DM_MAPIO_REMAPPED;
}
/*
* We need to parse hex numbers in the message as quickly as possible.
*
* This table-based hex parser improves performance.
* It improves a time to load 1000000 entries compared to the condition-based
* parser.
* table-based parser condition-based parser
* PA-RISC 0.29s 0.31s
* Opteron 0.0495s 0.0498s
*/
static const unsigned char hex_table[256] = {
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 255, 255, 255, 255, 255, 255,
255, 10, 11, 12, 13, 14, 15, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 10, 11, 12, 13, 14, 15, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255
};
static __always_inline unsigned long parse_hex(const char **string)
{
unsigned char d;
unsigned long r = 0;
while ((d = hex_table[(unsigned char)**string]) < 16) {
r = (r << 4) | d;
(*string)++;
}
return r;
}
static int process_set_region_mappings(struct switch_ctx *sctx,
unsigned int argc, char **argv)
{
unsigned int i;
unsigned long region_index = 0;
for (i = 1; i < argc; i++) {
unsigned long path_nr;
const char *string = argv[i];
if ((*string & 0xdf) == 'R') {
unsigned long cycle_length, num_write;
string++;
if (unlikely(*string == ',')) {
DMWARN("invalid set_region_mappings argument: '%s'", argv[i]);
return -EINVAL;
}
cycle_length = parse_hex(&string);
if (unlikely(*string != ',')) {
DMWARN("invalid set_region_mappings argument: '%s'", argv[i]);
return -EINVAL;
}
string++;
if (unlikely(!*string)) {
DMWARN("invalid set_region_mappings argument: '%s'", argv[i]);
return -EINVAL;
}
num_write = parse_hex(&string);
if (unlikely(*string)) {
DMWARN("invalid set_region_mappings argument: '%s'", argv[i]);
return -EINVAL;
}
if (unlikely(!cycle_length) || unlikely(cycle_length - 1 > region_index)) {
DMWARN("invalid set_region_mappings cycle length: %lu > %lu",
cycle_length - 1, region_index);
return -EINVAL;
}
if (unlikely(region_index + num_write < region_index) ||
unlikely(region_index + num_write >= sctx->nr_regions)) {
DMWARN("invalid set_region_mappings region number: %lu + %lu >= %lu",
region_index, num_write, sctx->nr_regions);
return -EINVAL;
}
while (num_write--) {
region_index++;
path_nr = switch_region_table_read(sctx, region_index - cycle_length);
switch_region_table_write(sctx, region_index, path_nr);
}
continue;
}
if (*string == ':')
region_index++;
else {
region_index = parse_hex(&string);
if (unlikely(*string != ':')) {
DMWARN("invalid set_region_mappings argument: '%s'", argv[i]);
return -EINVAL;
}
}
string++;
if (unlikely(!*string)) {
DMWARN("invalid set_region_mappings argument: '%s'", argv[i]);
return -EINVAL;
}
path_nr = parse_hex(&string);
if (unlikely(*string)) {
DMWARN("invalid set_region_mappings argument: '%s'", argv[i]);
return -EINVAL;
}
if (unlikely(region_index >= sctx->nr_regions)) {
DMWARN("invalid set_region_mappings region number: %lu >= %lu", region_index, sctx->nr_regions);
return -EINVAL;
}
if (unlikely(path_nr >= sctx->nr_paths)) {
DMWARN("invalid set_region_mappings device: %lu >= %u", path_nr, sctx->nr_paths);
return -EINVAL;
}
switch_region_table_write(sctx, region_index, path_nr);
}
return 0;
}
/*
* Messages are processed one-at-a-time.
*
* Only set_region_mappings is supported.
*/
static int switch_message(struct dm_target *ti, unsigned int argc, char **argv,
char *result, unsigned int maxlen)
{
static DEFINE_MUTEX(message_mutex);
struct switch_ctx *sctx = ti->private;
int r = -EINVAL;
mutex_lock(&message_mutex);
if (!strcasecmp(argv[0], "set_region_mappings"))
r = process_set_region_mappings(sctx, argc, argv);
else
DMWARN("Unrecognised message received.");
mutex_unlock(&message_mutex);
return r;
}
static void switch_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
struct switch_ctx *sctx = ti->private;
unsigned int sz = 0;
int path_nr;
switch (type) {
case STATUSTYPE_INFO:
result[0] = '\0';
break;
case STATUSTYPE_TABLE:
DMEMIT("%u %u 0", sctx->nr_paths, sctx->region_size);
for (path_nr = 0; path_nr < sctx->nr_paths; path_nr++)
DMEMIT(" %s %llu", sctx->path_list[path_nr].dmdev->name,
(unsigned long long)sctx->path_list[path_nr].start);
break;
case STATUSTYPE_IMA:
result[0] = '\0';
break;
}
}
/*
* Switch ioctl:
*
* Passthrough all ioctls to the path for sector 0
*/
static int switch_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
{
struct switch_ctx *sctx = ti->private;
unsigned int path_nr;
path_nr = switch_get_path_nr(sctx, 0);
*bdev = sctx->path_list[path_nr].dmdev->bdev;
/*
* Only pass ioctls through if the device sizes match exactly.
*/
if (ti->len + sctx->path_list[path_nr].start !=
bdev_nr_sectors((*bdev)))
return 1;
return 0;
}
static int switch_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct switch_ctx *sctx = ti->private;
int path_nr;
int r;
for (path_nr = 0; path_nr < sctx->nr_paths; path_nr++) {
r = fn(ti, sctx->path_list[path_nr].dmdev,
sctx->path_list[path_nr].start, ti->len, data);
if (r)
return r;
}
return 0;
}
static struct target_type switch_target = {
.name = "switch",
.version = {1, 1, 0},
.features = DM_TARGET_NOWAIT,
.module = THIS_MODULE,
.ctr = switch_ctr,
.dtr = switch_dtr,
.map = switch_map,
.message = switch_message,
.status = switch_status,
.prepare_ioctl = switch_prepare_ioctl,
.iterate_devices = switch_iterate_devices,
};
module_dm(switch);
MODULE_DESCRIPTION(DM_NAME " dynamic path switching target");
MODULE_AUTHOR("Kevin D. O'Kelley <[email protected]>");
MODULE_AUTHOR("Narendran Ganapathy <[email protected]>");
MODULE_AUTHOR("Jim Ramsay <[email protected]>");
MODULE_AUTHOR("Mikulas Patocka <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-switch.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2004-2005 IBM Corp. All Rights Reserved.
* Copyright (C) 2006-2009 NEC Corporation.
*
* dm-queue-length.c
*
* Module Author: Stefan Bader, IBM
* Modified by: Kiyoshi Ueda, NEC
*
* This file is released under the GPL.
*
* queue-length path selector - choose a path with the least number of
* in-flight I/Os.
*/
#include "dm.h"
#include "dm-path-selector.h"
#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/atomic.h>
#define DM_MSG_PREFIX "multipath queue-length"
#define QL_MIN_IO 1
#define QL_VERSION "0.2.0"
struct selector {
struct list_head valid_paths;
struct list_head failed_paths;
spinlock_t lock;
};
struct path_info {
struct list_head list;
struct dm_path *path;
unsigned int repeat_count;
atomic_t qlen; /* the number of in-flight I/Os */
};
static struct selector *alloc_selector(void)
{
struct selector *s = kmalloc(sizeof(*s), GFP_KERNEL);
if (s) {
INIT_LIST_HEAD(&s->valid_paths);
INIT_LIST_HEAD(&s->failed_paths);
spin_lock_init(&s->lock);
}
return s;
}
static int ql_create(struct path_selector *ps, unsigned int argc, char **argv)
{
struct selector *s = alloc_selector();
if (!s)
return -ENOMEM;
ps->context = s;
return 0;
}
static void ql_free_paths(struct list_head *paths)
{
struct path_info *pi, *next;
list_for_each_entry_safe(pi, next, paths, list) {
list_del(&pi->list);
kfree(pi);
}
}
static void ql_destroy(struct path_selector *ps)
{
struct selector *s = ps->context;
ql_free_paths(&s->valid_paths);
ql_free_paths(&s->failed_paths);
kfree(s);
ps->context = NULL;
}
static int ql_status(struct path_selector *ps, struct dm_path *path,
status_type_t type, char *result, unsigned int maxlen)
{
unsigned int sz = 0;
struct path_info *pi;
/* When called with NULL path, return selector status/args. */
if (!path)
DMEMIT("0 ");
else {
pi = path->pscontext;
switch (type) {
case STATUSTYPE_INFO:
DMEMIT("%d ", atomic_read(&pi->qlen));
break;
case STATUSTYPE_TABLE:
DMEMIT("%u ", pi->repeat_count);
break;
case STATUSTYPE_IMA:
*result = '\0';
break;
}
}
return sz;
}
static int ql_add_path(struct path_selector *ps, struct dm_path *path,
int argc, char **argv, char **error)
{
struct selector *s = ps->context;
struct path_info *pi;
unsigned int repeat_count = QL_MIN_IO;
char dummy;
unsigned long flags;
/*
* Arguments: [<repeat_count>]
* <repeat_count>: The number of I/Os before switching path.
* If not given, default (QL_MIN_IO) is used.
*/
if (argc > 1) {
*error = "queue-length ps: incorrect number of arguments";
return -EINVAL;
}
if ((argc == 1) && (sscanf(argv[0], "%u%c", &repeat_count, &dummy) != 1)) {
*error = "queue-length ps: invalid repeat count";
return -EINVAL;
}
if (repeat_count > 1) {
DMWARN_LIMIT("repeat_count > 1 is deprecated, using 1 instead");
repeat_count = 1;
}
/* Allocate the path information structure */
pi = kmalloc(sizeof(*pi), GFP_KERNEL);
if (!pi) {
*error = "queue-length ps: Error allocating path information";
return -ENOMEM;
}
pi->path = path;
pi->repeat_count = repeat_count;
atomic_set(&pi->qlen, 0);
path->pscontext = pi;
spin_lock_irqsave(&s->lock, flags);
list_add_tail(&pi->list, &s->valid_paths);
spin_unlock_irqrestore(&s->lock, flags);
return 0;
}
static void ql_fail_path(struct path_selector *ps, struct dm_path *path)
{
struct selector *s = ps->context;
struct path_info *pi = path->pscontext;
unsigned long flags;
spin_lock_irqsave(&s->lock, flags);
list_move(&pi->list, &s->failed_paths);
spin_unlock_irqrestore(&s->lock, flags);
}
static int ql_reinstate_path(struct path_selector *ps, struct dm_path *path)
{
struct selector *s = ps->context;
struct path_info *pi = path->pscontext;
unsigned long flags;
spin_lock_irqsave(&s->lock, flags);
list_move_tail(&pi->list, &s->valid_paths);
spin_unlock_irqrestore(&s->lock, flags);
return 0;
}
/*
* Select a path having the minimum number of in-flight I/Os
*/
static struct dm_path *ql_select_path(struct path_selector *ps, size_t nr_bytes)
{
struct selector *s = ps->context;
struct path_info *pi = NULL, *best = NULL;
struct dm_path *ret = NULL;
unsigned long flags;
spin_lock_irqsave(&s->lock, flags);
if (list_empty(&s->valid_paths))
goto out;
list_for_each_entry(pi, &s->valid_paths, list) {
if (!best ||
(atomic_read(&pi->qlen) < atomic_read(&best->qlen)))
best = pi;
if (!atomic_read(&best->qlen))
break;
}
if (!best)
goto out;
/* Move most recently used to least preferred to evenly balance. */
list_move_tail(&best->list, &s->valid_paths);
ret = best->path;
out:
spin_unlock_irqrestore(&s->lock, flags);
return ret;
}
static int ql_start_io(struct path_selector *ps, struct dm_path *path,
size_t nr_bytes)
{
struct path_info *pi = path->pscontext;
atomic_inc(&pi->qlen);
return 0;
}
static int ql_end_io(struct path_selector *ps, struct dm_path *path,
size_t nr_bytes, u64 start_time)
{
struct path_info *pi = path->pscontext;
atomic_dec(&pi->qlen);
return 0;
}
static struct path_selector_type ql_ps = {
.name = "queue-length",
.module = THIS_MODULE,
.table_args = 1,
.info_args = 1,
.create = ql_create,
.destroy = ql_destroy,
.status = ql_status,
.add_path = ql_add_path,
.fail_path = ql_fail_path,
.reinstate_path = ql_reinstate_path,
.select_path = ql_select_path,
.start_io = ql_start_io,
.end_io = ql_end_io,
};
static int __init dm_ql_init(void)
{
int r = dm_register_path_selector(&ql_ps);
if (r < 0)
DMERR("register failed %d", r);
DMINFO("version " QL_VERSION " loaded");
return r;
}
static void __exit dm_ql_exit(void)
{
int r = dm_unregister_path_selector(&ql_ps);
if (r < 0)
DMERR("unregister failed %d", r);
}
module_init(dm_ql_init);
module_exit(dm_ql_exit);
MODULE_AUTHOR("Stefan Bader <Stefan.Bader at de.ibm.com>");
MODULE_DESCRIPTION(
"(C) Copyright IBM Corp. 2004,2005 All Rights Reserved.\n"
DM_NAME " path selector to balance the number of in-flight I/Os"
);
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-ps-queue-length.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012 Red Hat. All rights reserved.
*
* This file is released under the GPL.
*/
#include "dm-cache-policy-internal.h"
#include "dm.h"
#include <linux/module.h>
#include <linux/slab.h>
/*----------------------------------------------------------------*/
#define DM_MSG_PREFIX "cache-policy"
static DEFINE_SPINLOCK(register_lock);
static LIST_HEAD(register_list);
static struct dm_cache_policy_type *__find_policy(const char *name)
{
struct dm_cache_policy_type *t;
list_for_each_entry(t, ®ister_list, list)
if (!strcmp(t->name, name))
return t;
return NULL;
}
static struct dm_cache_policy_type *__get_policy_once(const char *name)
{
struct dm_cache_policy_type *t = __find_policy(name);
if (t && !try_module_get(t->owner)) {
DMWARN("couldn't get module %s", name);
t = ERR_PTR(-EINVAL);
}
return t;
}
static struct dm_cache_policy_type *get_policy_once(const char *name)
{
struct dm_cache_policy_type *t;
spin_lock(®ister_lock);
t = __get_policy_once(name);
spin_unlock(®ister_lock);
return t;
}
static struct dm_cache_policy_type *get_policy(const char *name)
{
struct dm_cache_policy_type *t;
t = get_policy_once(name);
if (IS_ERR(t))
return NULL;
if (t)
return t;
request_module("dm-cache-%s", name);
t = get_policy_once(name);
if (IS_ERR(t))
return NULL;
return t;
}
static void put_policy(struct dm_cache_policy_type *t)
{
module_put(t->owner);
}
int dm_cache_policy_register(struct dm_cache_policy_type *type)
{
int r;
/* One size fits all for now */
if (type->hint_size != 0 && type->hint_size != 4) {
DMWARN("hint size must be 0 or 4 but %llu supplied.", (unsigned long long) type->hint_size);
return -EINVAL;
}
spin_lock(®ister_lock);
if (__find_policy(type->name)) {
DMWARN("attempt to register policy under duplicate name %s", type->name);
r = -EINVAL;
} else {
list_add(&type->list, ®ister_list);
r = 0;
}
spin_unlock(®ister_lock);
return r;
}
EXPORT_SYMBOL_GPL(dm_cache_policy_register);
void dm_cache_policy_unregister(struct dm_cache_policy_type *type)
{
spin_lock(®ister_lock);
list_del_init(&type->list);
spin_unlock(®ister_lock);
}
EXPORT_SYMBOL_GPL(dm_cache_policy_unregister);
struct dm_cache_policy *dm_cache_policy_create(const char *name,
dm_cblock_t cache_size,
sector_t origin_size,
sector_t cache_block_size)
{
struct dm_cache_policy *p = NULL;
struct dm_cache_policy_type *type;
type = get_policy(name);
if (!type) {
DMWARN("unknown policy type");
return ERR_PTR(-EINVAL);
}
p = type->create(cache_size, origin_size, cache_block_size);
if (!p) {
put_policy(type);
return ERR_PTR(-ENOMEM);
}
p->private = type;
return p;
}
EXPORT_SYMBOL_GPL(dm_cache_policy_create);
void dm_cache_policy_destroy(struct dm_cache_policy *p)
{
struct dm_cache_policy_type *t = p->private;
p->destroy(p);
put_policy(t);
}
EXPORT_SYMBOL_GPL(dm_cache_policy_destroy);
const char *dm_cache_policy_get_name(struct dm_cache_policy *p)
{
struct dm_cache_policy_type *t = p->private;
/* if t->real is set then an alias was used (e.g. "default") */
if (t->real)
return t->real->name;
return t->name;
}
EXPORT_SYMBOL_GPL(dm_cache_policy_get_name);
const unsigned int *dm_cache_policy_get_version(struct dm_cache_policy *p)
{
struct dm_cache_policy_type *t = p->private;
return t->version;
}
EXPORT_SYMBOL_GPL(dm_cache_policy_get_version);
size_t dm_cache_policy_get_hint_size(struct dm_cache_policy *p)
{
struct dm_cache_policy_type *t = p->private;
return t->hint_size;
}
EXPORT_SYMBOL_GPL(dm_cache_policy_get_hint_size);
/*----------------------------------------------------------------*/
| linux-master | drivers/md/dm-cache-policy.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2003 Sistina Software.
* Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
*
* Module Author: Heinz Mauelshagen
*
* This file is released under the GPL.
*
* Round-robin path selector.
*/
#include <linux/device-mapper.h>
#include "dm-path-selector.h"
#include <linux/slab.h>
#include <linux/module.h>
#define DM_MSG_PREFIX "multipath round-robin"
#define RR_MIN_IO 1
#define RR_VERSION "1.2.0"
/*
*---------------------------------------------------------------
* Path-handling code, paths are held in lists
*---------------------------------------------------------------
*/
struct path_info {
struct list_head list;
struct dm_path *path;
unsigned int repeat_count;
};
static void free_paths(struct list_head *paths)
{
struct path_info *pi, *next;
list_for_each_entry_safe(pi, next, paths, list) {
list_del(&pi->list);
kfree(pi);
}
}
/*
*---------------------------------------------------------------
* Round-robin selector
*---------------------------------------------------------------
*/
struct selector {
struct list_head valid_paths;
struct list_head invalid_paths;
spinlock_t lock;
};
static struct selector *alloc_selector(void)
{
struct selector *s = kmalloc(sizeof(*s), GFP_KERNEL);
if (s) {
INIT_LIST_HEAD(&s->valid_paths);
INIT_LIST_HEAD(&s->invalid_paths);
spin_lock_init(&s->lock);
}
return s;
}
static int rr_create(struct path_selector *ps, unsigned int argc, char **argv)
{
struct selector *s;
s = alloc_selector();
if (!s)
return -ENOMEM;
ps->context = s;
return 0;
}
static void rr_destroy(struct path_selector *ps)
{
struct selector *s = ps->context;
free_paths(&s->valid_paths);
free_paths(&s->invalid_paths);
kfree(s);
ps->context = NULL;
}
static int rr_status(struct path_selector *ps, struct dm_path *path,
status_type_t type, char *result, unsigned int maxlen)
{
struct path_info *pi;
int sz = 0;
if (!path)
DMEMIT("0 ");
else {
switch (type) {
case STATUSTYPE_INFO:
break;
case STATUSTYPE_TABLE:
pi = path->pscontext;
DMEMIT("%u ", pi->repeat_count);
break;
case STATUSTYPE_IMA:
*result = '\0';
break;
}
}
return sz;
}
/*
* Called during initialisation to register each path with an
* optional repeat_count.
*/
static int rr_add_path(struct path_selector *ps, struct dm_path *path,
int argc, char **argv, char **error)
{
struct selector *s = ps->context;
struct path_info *pi;
unsigned int repeat_count = RR_MIN_IO;
char dummy;
unsigned long flags;
if (argc > 1) {
*error = "round-robin ps: incorrect number of arguments";
return -EINVAL;
}
/* First path argument is number of I/Os before switching path */
if ((argc == 1) && (sscanf(argv[0], "%u%c", &repeat_count, &dummy) != 1)) {
*error = "round-robin ps: invalid repeat count";
return -EINVAL;
}
if (repeat_count > 1) {
DMWARN_LIMIT("repeat_count > 1 is deprecated, using 1 instead");
repeat_count = 1;
}
/* allocate the path */
pi = kmalloc(sizeof(*pi), GFP_KERNEL);
if (!pi) {
*error = "round-robin ps: Error allocating path context";
return -ENOMEM;
}
pi->path = path;
pi->repeat_count = repeat_count;
path->pscontext = pi;
spin_lock_irqsave(&s->lock, flags);
list_add_tail(&pi->list, &s->valid_paths);
spin_unlock_irqrestore(&s->lock, flags);
return 0;
}
static void rr_fail_path(struct path_selector *ps, struct dm_path *p)
{
unsigned long flags;
struct selector *s = ps->context;
struct path_info *pi = p->pscontext;
spin_lock_irqsave(&s->lock, flags);
list_move(&pi->list, &s->invalid_paths);
spin_unlock_irqrestore(&s->lock, flags);
}
static int rr_reinstate_path(struct path_selector *ps, struct dm_path *p)
{
unsigned long flags;
struct selector *s = ps->context;
struct path_info *pi = p->pscontext;
spin_lock_irqsave(&s->lock, flags);
list_move(&pi->list, &s->valid_paths);
spin_unlock_irqrestore(&s->lock, flags);
return 0;
}
static struct dm_path *rr_select_path(struct path_selector *ps, size_t nr_bytes)
{
unsigned long flags;
struct selector *s = ps->context;
struct path_info *pi = NULL;
spin_lock_irqsave(&s->lock, flags);
if (!list_empty(&s->valid_paths)) {
pi = list_entry(s->valid_paths.next, struct path_info, list);
list_move_tail(&pi->list, &s->valid_paths);
}
spin_unlock_irqrestore(&s->lock, flags);
return pi ? pi->path : NULL;
}
static struct path_selector_type rr_ps = {
.name = "round-robin",
.module = THIS_MODULE,
.table_args = 1,
.info_args = 0,
.create = rr_create,
.destroy = rr_destroy,
.status = rr_status,
.add_path = rr_add_path,
.fail_path = rr_fail_path,
.reinstate_path = rr_reinstate_path,
.select_path = rr_select_path,
};
static int __init dm_rr_init(void)
{
int r = dm_register_path_selector(&rr_ps);
if (r < 0)
DMERR("register failed %d", r);
DMINFO("version " RR_VERSION " loaded");
return r;
}
static void __exit dm_rr_exit(void)
{
int r = dm_unregister_path_selector(&rr_ps);
if (r < 0)
DMERR("unregister failed %d", r);
}
module_init(dm_rr_init);
module_exit(dm_rr_exit);
MODULE_DESCRIPTION(DM_NAME " round-robin multipath path selector");
MODULE_AUTHOR("Sistina Software <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-ps-round-robin.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2017 Intel Corporation.
*
* This file is released under the GPL.
*/
#include "dm.h"
#include <linux/module.h>
struct unstripe_c {
struct dm_dev *dev;
sector_t physical_start;
uint32_t stripes;
uint32_t unstripe;
sector_t unstripe_width;
sector_t unstripe_offset;
uint32_t chunk_size;
u8 chunk_shift;
};
#define DM_MSG_PREFIX "unstriped"
static void cleanup_unstripe(struct unstripe_c *uc, struct dm_target *ti)
{
if (uc->dev)
dm_put_device(ti, uc->dev);
kfree(uc);
}
/*
* Contruct an unstriped mapping.
* <number of stripes> <chunk size> <stripe #> <dev_path> <offset>
*/
static int unstripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
struct unstripe_c *uc;
sector_t tmp_len;
unsigned long long start;
char dummy;
if (argc != 5) {
ti->error = "Invalid number of arguments";
return -EINVAL;
}
uc = kzalloc(sizeof(*uc), GFP_KERNEL);
if (!uc) {
ti->error = "Memory allocation for unstriped context failed";
return -ENOMEM;
}
if (kstrtouint(argv[0], 10, &uc->stripes) || !uc->stripes) {
ti->error = "Invalid stripe count";
goto err;
}
if (kstrtouint(argv[1], 10, &uc->chunk_size) || !uc->chunk_size) {
ti->error = "Invalid chunk_size";
goto err;
}
if (kstrtouint(argv[2], 10, &uc->unstripe)) {
ti->error = "Invalid stripe number";
goto err;
}
if (uc->unstripe > uc->stripes && uc->stripes > 1) {
ti->error = "Please provide stripe between [0, # of stripes]";
goto err;
}
if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &uc->dev)) {
ti->error = "Couldn't get striped device";
goto err;
}
if (sscanf(argv[4], "%llu%c", &start, &dummy) != 1 || start != (sector_t)start) {
ti->error = "Invalid striped device offset";
goto err;
}
uc->physical_start = start;
uc->unstripe_offset = uc->unstripe * uc->chunk_size;
uc->unstripe_width = (uc->stripes - 1) * uc->chunk_size;
uc->chunk_shift = is_power_of_2(uc->chunk_size) ? fls(uc->chunk_size) - 1 : 0;
tmp_len = ti->len;
if (sector_div(tmp_len, uc->chunk_size)) {
ti->error = "Target length not divisible by chunk size";
goto err;
}
if (dm_set_target_max_io_len(ti, uc->chunk_size)) {
ti->error = "Failed to set max io len";
goto err;
}
ti->private = uc;
return 0;
err:
cleanup_unstripe(uc, ti);
return -EINVAL;
}
static void unstripe_dtr(struct dm_target *ti)
{
struct unstripe_c *uc = ti->private;
cleanup_unstripe(uc, ti);
}
static sector_t map_to_core(struct dm_target *ti, struct bio *bio)
{
struct unstripe_c *uc = ti->private;
sector_t sector = bio->bi_iter.bi_sector;
sector_t tmp_sector = sector;
/* Shift us up to the right "row" on the stripe */
if (uc->chunk_shift)
tmp_sector >>= uc->chunk_shift;
else
sector_div(tmp_sector, uc->chunk_size);
sector += uc->unstripe_width * tmp_sector;
/* Account for what stripe we're operating on */
return sector + uc->unstripe_offset;
}
static int unstripe_map(struct dm_target *ti, struct bio *bio)
{
struct unstripe_c *uc = ti->private;
bio_set_dev(bio, uc->dev->bdev);
bio->bi_iter.bi_sector = map_to_core(ti, bio) + uc->physical_start;
return DM_MAPIO_REMAPPED;
}
static void unstripe_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
struct unstripe_c *uc = ti->private;
unsigned int sz = 0;
switch (type) {
case STATUSTYPE_INFO:
break;
case STATUSTYPE_TABLE:
DMEMIT("%d %llu %d %s %llu",
uc->stripes, (unsigned long long)uc->chunk_size, uc->unstripe,
uc->dev->name, (unsigned long long)uc->physical_start);
break;
case STATUSTYPE_IMA:
*result = '\0';
break;
}
}
static int unstripe_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct unstripe_c *uc = ti->private;
return fn(ti, uc->dev, uc->physical_start, ti->len, data);
}
static void unstripe_io_hints(struct dm_target *ti,
struct queue_limits *limits)
{
struct unstripe_c *uc = ti->private;
limits->chunk_sectors = uc->chunk_size;
}
static struct target_type unstripe_target = {
.name = "unstriped",
.version = {1, 1, 0},
.features = DM_TARGET_NOWAIT,
.module = THIS_MODULE,
.ctr = unstripe_ctr,
.dtr = unstripe_dtr,
.map = unstripe_map,
.status = unstripe_status,
.iterate_devices = unstripe_iterate_devices,
.io_hints = unstripe_io_hints,
};
module_dm(unstripe);
MODULE_DESCRIPTION(DM_NAME " unstriped target");
MODULE_ALIAS("dm-unstriped");
MODULE_AUTHOR("Scott Bauer <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-unstripe.c |
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* raid1.c : Multiple Devices driver for Linux
*
* Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
*
* Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
*
* RAID-1 management functions.
*
* Better read-balancing code written by Mika Kuoppala <[email protected]>, 2000
*
* Fixes to reconstruction by Jakob Østergaard" <[email protected]>
* Various fixes by Neil Brown <[email protected]>
*
* Changes by Peter T. Breuer <[email protected]> 31/1/2003 to support
* bitmapped intelligence in resync:
*
* - bitmap marked during normal i/o
* - bitmap used to skip nondirty blocks during sync
*
* Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
* - persistent bitmap code
*/
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/blkdev.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/ratelimit.h>
#include <linux/interval_tree_generic.h>
#include <trace/events/block.h>
#include "md.h"
#include "raid1.h"
#include "md-bitmap.h"
#define UNSUPPORTED_MDDEV_FLAGS \
((1L << MD_HAS_JOURNAL) | \
(1L << MD_JOURNAL_CLEAN) | \
(1L << MD_HAS_PPL) | \
(1L << MD_HAS_MULTIPLE_PPLS))
static void allow_barrier(struct r1conf *conf, sector_t sector_nr);
static void lower_barrier(struct r1conf *conf, sector_t sector_nr);
#define raid1_log(md, fmt, args...) \
do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid1 " fmt, ##args); } while (0)
#include "raid1-10.c"
#define START(node) ((node)->start)
#define LAST(node) ((node)->last)
INTERVAL_TREE_DEFINE(struct serial_info, node, sector_t, _subtree_last,
START, LAST, static inline, raid1_rb);
static int check_and_add_serial(struct md_rdev *rdev, struct r1bio *r1_bio,
struct serial_info *si, int idx)
{
unsigned long flags;
int ret = 0;
sector_t lo = r1_bio->sector;
sector_t hi = lo + r1_bio->sectors;
struct serial_in_rdev *serial = &rdev->serial[idx];
spin_lock_irqsave(&serial->serial_lock, flags);
/* collision happened */
if (raid1_rb_iter_first(&serial->serial_rb, lo, hi))
ret = -EBUSY;
else {
si->start = lo;
si->last = hi;
raid1_rb_insert(si, &serial->serial_rb);
}
spin_unlock_irqrestore(&serial->serial_lock, flags);
return ret;
}
static void wait_for_serialization(struct md_rdev *rdev, struct r1bio *r1_bio)
{
struct mddev *mddev = rdev->mddev;
struct serial_info *si;
int idx = sector_to_idx(r1_bio->sector);
struct serial_in_rdev *serial = &rdev->serial[idx];
if (WARN_ON(!mddev->serial_info_pool))
return;
si = mempool_alloc(mddev->serial_info_pool, GFP_NOIO);
wait_event(serial->serial_io_wait,
check_and_add_serial(rdev, r1_bio, si, idx) == 0);
}
static void remove_serial(struct md_rdev *rdev, sector_t lo, sector_t hi)
{
struct serial_info *si;
unsigned long flags;
int found = 0;
struct mddev *mddev = rdev->mddev;
int idx = sector_to_idx(lo);
struct serial_in_rdev *serial = &rdev->serial[idx];
spin_lock_irqsave(&serial->serial_lock, flags);
for (si = raid1_rb_iter_first(&serial->serial_rb, lo, hi);
si; si = raid1_rb_iter_next(si, lo, hi)) {
if (si->start == lo && si->last == hi) {
raid1_rb_remove(si, &serial->serial_rb);
mempool_free(si, mddev->serial_info_pool);
found = 1;
break;
}
}
if (!found)
WARN(1, "The write IO is not recorded for serialization\n");
spin_unlock_irqrestore(&serial->serial_lock, flags);
wake_up(&serial->serial_io_wait);
}
/*
* for resync bio, r1bio pointer can be retrieved from the per-bio
* 'struct resync_pages'.
*/
static inline struct r1bio *get_resync_r1bio(struct bio *bio)
{
return get_resync_pages(bio)->raid_bio;
}
static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
{
struct pool_info *pi = data;
int size = offsetof(struct r1bio, bios[pi->raid_disks]);
/* allocate a r1bio with room for raid_disks entries in the bios array */
return kzalloc(size, gfp_flags);
}
#define RESYNC_DEPTH 32
#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
#define RESYNC_WINDOW (RESYNC_BLOCK_SIZE * RESYNC_DEPTH)
#define RESYNC_WINDOW_SECTORS (RESYNC_WINDOW >> 9)
#define CLUSTER_RESYNC_WINDOW (16 * RESYNC_WINDOW)
#define CLUSTER_RESYNC_WINDOW_SECTORS (CLUSTER_RESYNC_WINDOW >> 9)
static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
{
struct pool_info *pi = data;
struct r1bio *r1_bio;
struct bio *bio;
int need_pages;
int j;
struct resync_pages *rps;
r1_bio = r1bio_pool_alloc(gfp_flags, pi);
if (!r1_bio)
return NULL;
rps = kmalloc_array(pi->raid_disks, sizeof(struct resync_pages),
gfp_flags);
if (!rps)
goto out_free_r1bio;
/*
* Allocate bios : 1 for reading, n-1 for writing
*/
for (j = pi->raid_disks ; j-- ; ) {
bio = bio_kmalloc(RESYNC_PAGES, gfp_flags);
if (!bio)
goto out_free_bio;
bio_init(bio, NULL, bio->bi_inline_vecs, RESYNC_PAGES, 0);
r1_bio->bios[j] = bio;
}
/*
* Allocate RESYNC_PAGES data pages and attach them to
* the first bio.
* If this is a user-requested check/repair, allocate
* RESYNC_PAGES for each bio.
*/
if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery))
need_pages = pi->raid_disks;
else
need_pages = 1;
for (j = 0; j < pi->raid_disks; j++) {
struct resync_pages *rp = &rps[j];
bio = r1_bio->bios[j];
if (j < need_pages) {
if (resync_alloc_pages(rp, gfp_flags))
goto out_free_pages;
} else {
memcpy(rp, &rps[0], sizeof(*rp));
resync_get_all_pages(rp);
}
rp->raid_bio = r1_bio;
bio->bi_private = rp;
}
r1_bio->master_bio = NULL;
return r1_bio;
out_free_pages:
while (--j >= 0)
resync_free_pages(&rps[j]);
out_free_bio:
while (++j < pi->raid_disks) {
bio_uninit(r1_bio->bios[j]);
kfree(r1_bio->bios[j]);
}
kfree(rps);
out_free_r1bio:
rbio_pool_free(r1_bio, data);
return NULL;
}
static void r1buf_pool_free(void *__r1_bio, void *data)
{
struct pool_info *pi = data;
int i;
struct r1bio *r1bio = __r1_bio;
struct resync_pages *rp = NULL;
for (i = pi->raid_disks; i--; ) {
rp = get_resync_pages(r1bio->bios[i]);
resync_free_pages(rp);
bio_uninit(r1bio->bios[i]);
kfree(r1bio->bios[i]);
}
/* resync pages array stored in the 1st bio's .bi_private */
kfree(rp);
rbio_pool_free(r1bio, data);
}
static void put_all_bios(struct r1conf *conf, struct r1bio *r1_bio)
{
int i;
for (i = 0; i < conf->raid_disks * 2; i++) {
struct bio **bio = r1_bio->bios + i;
if (!BIO_SPECIAL(*bio))
bio_put(*bio);
*bio = NULL;
}
}
static void free_r1bio(struct r1bio *r1_bio)
{
struct r1conf *conf = r1_bio->mddev->private;
put_all_bios(conf, r1_bio);
mempool_free(r1_bio, &conf->r1bio_pool);
}
static void put_buf(struct r1bio *r1_bio)
{
struct r1conf *conf = r1_bio->mddev->private;
sector_t sect = r1_bio->sector;
int i;
for (i = 0; i < conf->raid_disks * 2; i++) {
struct bio *bio = r1_bio->bios[i];
if (bio->bi_end_io)
rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
}
mempool_free(r1_bio, &conf->r1buf_pool);
lower_barrier(conf, sect);
}
static void reschedule_retry(struct r1bio *r1_bio)
{
unsigned long flags;
struct mddev *mddev = r1_bio->mddev;
struct r1conf *conf = mddev->private;
int idx;
idx = sector_to_idx(r1_bio->sector);
spin_lock_irqsave(&conf->device_lock, flags);
list_add(&r1_bio->retry_list, &conf->retry_list);
atomic_inc(&conf->nr_queued[idx]);
spin_unlock_irqrestore(&conf->device_lock, flags);
wake_up(&conf->wait_barrier);
md_wakeup_thread(mddev->thread);
}
/*
* raid_end_bio_io() is called when we have finished servicing a mirrored
* operation and are ready to return a success/failure code to the buffer
* cache layer.
*/
static void call_bio_endio(struct r1bio *r1_bio)
{
struct bio *bio = r1_bio->master_bio;
if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
bio->bi_status = BLK_STS_IOERR;
bio_endio(bio);
}
static void raid_end_bio_io(struct r1bio *r1_bio)
{
struct bio *bio = r1_bio->master_bio;
struct r1conf *conf = r1_bio->mddev->private;
sector_t sector = r1_bio->sector;
/* if nobody has done the final endio yet, do it now */
if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
pr_debug("raid1: sync end %s on sectors %llu-%llu\n",
(bio_data_dir(bio) == WRITE) ? "write" : "read",
(unsigned long long) bio->bi_iter.bi_sector,
(unsigned long long) bio_end_sector(bio) - 1);
call_bio_endio(r1_bio);
}
free_r1bio(r1_bio);
/*
* Wake up any possible resync thread that waits for the device
* to go idle. All I/Os, even write-behind writes, are done.
*/
allow_barrier(conf, sector);
}
/*
* Update disk head position estimator based on IRQ completion info.
*/
static inline void update_head_pos(int disk, struct r1bio *r1_bio)
{
struct r1conf *conf = r1_bio->mddev->private;
conf->mirrors[disk].head_position =
r1_bio->sector + (r1_bio->sectors);
}
/*
* Find the disk number which triggered given bio
*/
static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio)
{
int mirror;
struct r1conf *conf = r1_bio->mddev->private;
int raid_disks = conf->raid_disks;
for (mirror = 0; mirror < raid_disks * 2; mirror++)
if (r1_bio->bios[mirror] == bio)
break;
BUG_ON(mirror == raid_disks * 2);
update_head_pos(mirror, r1_bio);
return mirror;
}
static void raid1_end_read_request(struct bio *bio)
{
int uptodate = !bio->bi_status;
struct r1bio *r1_bio = bio->bi_private;
struct r1conf *conf = r1_bio->mddev->private;
struct md_rdev *rdev = conf->mirrors[r1_bio->read_disk].rdev;
/*
* this branch is our 'one mirror IO has finished' event handler:
*/
update_head_pos(r1_bio->read_disk, r1_bio);
if (uptodate)
set_bit(R1BIO_Uptodate, &r1_bio->state);
else if (test_bit(FailFast, &rdev->flags) &&
test_bit(R1BIO_FailFast, &r1_bio->state))
/* This was a fail-fast read so we definitely
* want to retry */
;
else {
/* If all other devices have failed, we want to return
* the error upwards rather than fail the last device.
* Here we redefine "uptodate" to mean "Don't want to retry"
*/
unsigned long flags;
spin_lock_irqsave(&conf->device_lock, flags);
if (r1_bio->mddev->degraded == conf->raid_disks ||
(r1_bio->mddev->degraded == conf->raid_disks-1 &&
test_bit(In_sync, &rdev->flags)))
uptodate = 1;
spin_unlock_irqrestore(&conf->device_lock, flags);
}
if (uptodate) {
raid_end_bio_io(r1_bio);
rdev_dec_pending(rdev, conf->mddev);
} else {
/*
* oops, read error:
*/
pr_err_ratelimited("md/raid1:%s: %pg: rescheduling sector %llu\n",
mdname(conf->mddev),
rdev->bdev,
(unsigned long long)r1_bio->sector);
set_bit(R1BIO_ReadError, &r1_bio->state);
reschedule_retry(r1_bio);
/* don't drop the reference on read_disk yet */
}
}
static void close_write(struct r1bio *r1_bio)
{
/* it really is the end of this request */
if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
bio_free_pages(r1_bio->behind_master_bio);
bio_put(r1_bio->behind_master_bio);
r1_bio->behind_master_bio = NULL;
}
/* clear the bitmap if all writes complete successfully */
md_bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector,
r1_bio->sectors,
!test_bit(R1BIO_Degraded, &r1_bio->state),
test_bit(R1BIO_BehindIO, &r1_bio->state));
md_write_end(r1_bio->mddev);
}
static void r1_bio_write_done(struct r1bio *r1_bio)
{
if (!atomic_dec_and_test(&r1_bio->remaining))
return;
if (test_bit(R1BIO_WriteError, &r1_bio->state))
reschedule_retry(r1_bio);
else {
close_write(r1_bio);
if (test_bit(R1BIO_MadeGood, &r1_bio->state))
reschedule_retry(r1_bio);
else
raid_end_bio_io(r1_bio);
}
}
static void raid1_end_write_request(struct bio *bio)
{
struct r1bio *r1_bio = bio->bi_private;
int behind = test_bit(R1BIO_BehindIO, &r1_bio->state);
struct r1conf *conf = r1_bio->mddev->private;
struct bio *to_put = NULL;
int mirror = find_bio_disk(r1_bio, bio);
struct md_rdev *rdev = conf->mirrors[mirror].rdev;
bool discard_error;
sector_t lo = r1_bio->sector;
sector_t hi = r1_bio->sector + r1_bio->sectors;
discard_error = bio->bi_status && bio_op(bio) == REQ_OP_DISCARD;
/*
* 'one mirror IO has finished' event handler:
*/
if (bio->bi_status && !discard_error) {
set_bit(WriteErrorSeen, &rdev->flags);
if (!test_and_set_bit(WantReplacement, &rdev->flags))
set_bit(MD_RECOVERY_NEEDED, &
conf->mddev->recovery);
if (test_bit(FailFast, &rdev->flags) &&
(bio->bi_opf & MD_FAILFAST) &&
/* We never try FailFast to WriteMostly devices */
!test_bit(WriteMostly, &rdev->flags)) {
md_error(r1_bio->mddev, rdev);
}
/*
* When the device is faulty, it is not necessary to
* handle write error.
*/
if (!test_bit(Faulty, &rdev->flags))
set_bit(R1BIO_WriteError, &r1_bio->state);
else {
/* Fail the request */
set_bit(R1BIO_Degraded, &r1_bio->state);
/* Finished with this branch */
r1_bio->bios[mirror] = NULL;
to_put = bio;
}
} else {
/*
* Set R1BIO_Uptodate in our master bio, so that we
* will return a good error code for to the higher
* levels even if IO on some other mirrored buffer
* fails.
*
* The 'master' represents the composite IO operation
* to user-side. So if something waits for IO, then it
* will wait for the 'master' bio.
*/
sector_t first_bad;
int bad_sectors;
r1_bio->bios[mirror] = NULL;
to_put = bio;
/*
* Do not set R1BIO_Uptodate if the current device is
* rebuilding or Faulty. This is because we cannot use
* such device for properly reading the data back (we could
* potentially use it, if the current write would have felt
* before rdev->recovery_offset, but for simplicity we don't
* check this here.
*/
if (test_bit(In_sync, &rdev->flags) &&
!test_bit(Faulty, &rdev->flags))
set_bit(R1BIO_Uptodate, &r1_bio->state);
/* Maybe we can clear some bad blocks. */
if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
&first_bad, &bad_sectors) && !discard_error) {
r1_bio->bios[mirror] = IO_MADE_GOOD;
set_bit(R1BIO_MadeGood, &r1_bio->state);
}
}
if (behind) {
if (test_bit(CollisionCheck, &rdev->flags))
remove_serial(rdev, lo, hi);
if (test_bit(WriteMostly, &rdev->flags))
atomic_dec(&r1_bio->behind_remaining);
/*
* In behind mode, we ACK the master bio once the I/O
* has safely reached all non-writemostly
* disks. Setting the Returned bit ensures that this
* gets done only once -- we don't ever want to return
* -EIO here, instead we'll wait
*/
if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) &&
test_bit(R1BIO_Uptodate, &r1_bio->state)) {
/* Maybe we can return now */
if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) {
struct bio *mbio = r1_bio->master_bio;
pr_debug("raid1: behind end write sectors"
" %llu-%llu\n",
(unsigned long long) mbio->bi_iter.bi_sector,
(unsigned long long) bio_end_sector(mbio) - 1);
call_bio_endio(r1_bio);
}
}
} else if (rdev->mddev->serialize_policy)
remove_serial(rdev, lo, hi);
if (r1_bio->bios[mirror] == NULL)
rdev_dec_pending(rdev, conf->mddev);
/*
* Let's see if all mirrored write operations have finished
* already.
*/
r1_bio_write_done(r1_bio);
if (to_put)
bio_put(to_put);
}
static sector_t align_to_barrier_unit_end(sector_t start_sector,
sector_t sectors)
{
sector_t len;
WARN_ON(sectors == 0);
/*
* len is the number of sectors from start_sector to end of the
* barrier unit which start_sector belongs to.
*/
len = round_up(start_sector + 1, BARRIER_UNIT_SECTOR_SIZE) -
start_sector;
if (len > sectors)
len = sectors;
return len;
}
/*
* This routine returns the disk from which the requested read should
* be done. There is a per-array 'next expected sequential IO' sector
* number - if this matches on the next IO then we use the last disk.
* There is also a per-disk 'last know head position' sector that is
* maintained from IRQ contexts, both the normal and the resync IO
* completion handlers update this position correctly. If there is no
* perfect sequential match then we pick the disk whose head is closest.
*
* If there are 2 mirrors in the same 2 devices, performance degrades
* because position is mirror, not device based.
*
* The rdev for the device selected will have nr_pending incremented.
*/
static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors)
{
const sector_t this_sector = r1_bio->sector;
int sectors;
int best_good_sectors;
int best_disk, best_dist_disk, best_pending_disk;
int has_nonrot_disk;
int disk;
sector_t best_dist;
unsigned int min_pending;
struct md_rdev *rdev;
int choose_first;
int choose_next_idle;
rcu_read_lock();
/*
* Check if we can balance. We can balance on the whole
* device if no resync is going on, or below the resync window.
* We take the first readable disk when above the resync window.
*/
retry:
sectors = r1_bio->sectors;
best_disk = -1;
best_dist_disk = -1;
best_dist = MaxSector;
best_pending_disk = -1;
min_pending = UINT_MAX;
best_good_sectors = 0;
has_nonrot_disk = 0;
choose_next_idle = 0;
clear_bit(R1BIO_FailFast, &r1_bio->state);
if ((conf->mddev->recovery_cp < this_sector + sectors) ||
(mddev_is_clustered(conf->mddev) &&
md_cluster_ops->area_resyncing(conf->mddev, READ, this_sector,
this_sector + sectors)))
choose_first = 1;
else
choose_first = 0;
for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) {
sector_t dist;
sector_t first_bad;
int bad_sectors;
unsigned int pending;
bool nonrot;
rdev = rcu_dereference(conf->mirrors[disk].rdev);
if (r1_bio->bios[disk] == IO_BLOCKED
|| rdev == NULL
|| test_bit(Faulty, &rdev->flags))
continue;
if (!test_bit(In_sync, &rdev->flags) &&
rdev->recovery_offset < this_sector + sectors)
continue;
if (test_bit(WriteMostly, &rdev->flags)) {
/* Don't balance among write-mostly, just
* use the first as a last resort */
if (best_dist_disk < 0) {
if (is_badblock(rdev, this_sector, sectors,
&first_bad, &bad_sectors)) {
if (first_bad <= this_sector)
/* Cannot use this */
continue;
best_good_sectors = first_bad - this_sector;
} else
best_good_sectors = sectors;
best_dist_disk = disk;
best_pending_disk = disk;
}
continue;
}
/* This is a reasonable device to use. It might
* even be best.
*/
if (is_badblock(rdev, this_sector, sectors,
&first_bad, &bad_sectors)) {
if (best_dist < MaxSector)
/* already have a better device */
continue;
if (first_bad <= this_sector) {
/* cannot read here. If this is the 'primary'
* device, then we must not read beyond
* bad_sectors from another device..
*/
bad_sectors -= (this_sector - first_bad);
if (choose_first && sectors > bad_sectors)
sectors = bad_sectors;
if (best_good_sectors > sectors)
best_good_sectors = sectors;
} else {
sector_t good_sectors = first_bad - this_sector;
if (good_sectors > best_good_sectors) {
best_good_sectors = good_sectors;
best_disk = disk;
}
if (choose_first)
break;
}
continue;
} else {
if ((sectors > best_good_sectors) && (best_disk >= 0))
best_disk = -1;
best_good_sectors = sectors;
}
if (best_disk >= 0)
/* At least two disks to choose from so failfast is OK */
set_bit(R1BIO_FailFast, &r1_bio->state);
nonrot = bdev_nonrot(rdev->bdev);
has_nonrot_disk |= nonrot;
pending = atomic_read(&rdev->nr_pending);
dist = abs(this_sector - conf->mirrors[disk].head_position);
if (choose_first) {
best_disk = disk;
break;
}
/* Don't change to another disk for sequential reads */
if (conf->mirrors[disk].next_seq_sect == this_sector
|| dist == 0) {
int opt_iosize = bdev_io_opt(rdev->bdev) >> 9;
struct raid1_info *mirror = &conf->mirrors[disk];
best_disk = disk;
/*
* If buffered sequential IO size exceeds optimal
* iosize, check if there is idle disk. If yes, choose
* the idle disk. read_balance could already choose an
* idle disk before noticing it's a sequential IO in
* this disk. This doesn't matter because this disk
* will idle, next time it will be utilized after the
* first disk has IO size exceeds optimal iosize. In
* this way, iosize of the first disk will be optimal
* iosize at least. iosize of the second disk might be
* small, but not a big deal since when the second disk
* starts IO, the first disk is likely still busy.
*/
if (nonrot && opt_iosize > 0 &&
mirror->seq_start != MaxSector &&
mirror->next_seq_sect > opt_iosize &&
mirror->next_seq_sect - opt_iosize >=
mirror->seq_start) {
choose_next_idle = 1;
continue;
}
break;
}
if (choose_next_idle)
continue;
if (min_pending > pending) {
min_pending = pending;
best_pending_disk = disk;
}
if (dist < best_dist) {
best_dist = dist;
best_dist_disk = disk;
}
}
/*
* If all disks are rotational, choose the closest disk. If any disk is
* non-rotational, choose the disk with less pending request even the
* disk is rotational, which might/might not be optimal for raids with
* mixed ratation/non-rotational disks depending on workload.
*/
if (best_disk == -1) {
if (has_nonrot_disk || min_pending == 0)
best_disk = best_pending_disk;
else
best_disk = best_dist_disk;
}
if (best_disk >= 0) {
rdev = rcu_dereference(conf->mirrors[best_disk].rdev);
if (!rdev)
goto retry;
atomic_inc(&rdev->nr_pending);
sectors = best_good_sectors;
if (conf->mirrors[best_disk].next_seq_sect != this_sector)
conf->mirrors[best_disk].seq_start = this_sector;
conf->mirrors[best_disk].next_seq_sect = this_sector + sectors;
}
rcu_read_unlock();
*max_sectors = sectors;
return best_disk;
}
static void wake_up_barrier(struct r1conf *conf)
{
if (wq_has_sleeper(&conf->wait_barrier))
wake_up(&conf->wait_barrier);
}
static void flush_bio_list(struct r1conf *conf, struct bio *bio)
{
/* flush any pending bitmap writes to disk before proceeding w/ I/O */
raid1_prepare_flush_writes(conf->mddev->bitmap);
wake_up_barrier(conf);
while (bio) { /* submit pending writes */
struct bio *next = bio->bi_next;
raid1_submit_write(bio);
bio = next;
cond_resched();
}
}
static void flush_pending_writes(struct r1conf *conf)
{
/* Any writes that have been queued but are awaiting
* bitmap updates get flushed here.
*/
spin_lock_irq(&conf->device_lock);
if (conf->pending_bio_list.head) {
struct blk_plug plug;
struct bio *bio;
bio = bio_list_get(&conf->pending_bio_list);
spin_unlock_irq(&conf->device_lock);
/*
* As this is called in a wait_event() loop (see freeze_array),
* current->state might be TASK_UNINTERRUPTIBLE which will
* cause a warning when we prepare to wait again. As it is
* rare that this path is taken, it is perfectly safe to force
* us to go around the wait_event() loop again, so the warning
* is a false-positive. Silence the warning by resetting
* thread state
*/
__set_current_state(TASK_RUNNING);
blk_start_plug(&plug);
flush_bio_list(conf, bio);
blk_finish_plug(&plug);
} else
spin_unlock_irq(&conf->device_lock);
}
/* Barriers....
* Sometimes we need to suspend IO while we do something else,
* either some resync/recovery, or reconfigure the array.
* To do this we raise a 'barrier'.
* The 'barrier' is a counter that can be raised multiple times
* to count how many activities are happening which preclude
* normal IO.
* We can only raise the barrier if there is no pending IO.
* i.e. if nr_pending == 0.
* We choose only to raise the barrier if no-one is waiting for the
* barrier to go down. This means that as soon as an IO request
* is ready, no other operations which require a barrier will start
* until the IO request has had a chance.
*
* So: regular IO calls 'wait_barrier'. When that returns there
* is no backgroup IO happening, It must arrange to call
* allow_barrier when it has finished its IO.
* backgroup IO calls must call raise_barrier. Once that returns
* there is no normal IO happeing. It must arrange to call
* lower_barrier when the particular background IO completes.
*
* If resync/recovery is interrupted, returns -EINTR;
* Otherwise, returns 0.
*/
static int raise_barrier(struct r1conf *conf, sector_t sector_nr)
{
int idx = sector_to_idx(sector_nr);
spin_lock_irq(&conf->resync_lock);
/* Wait until no block IO is waiting */
wait_event_lock_irq(conf->wait_barrier,
!atomic_read(&conf->nr_waiting[idx]),
conf->resync_lock);
/* block any new IO from starting */
atomic_inc(&conf->barrier[idx]);
/*
* In raise_barrier() we firstly increase conf->barrier[idx] then
* check conf->nr_pending[idx]. In _wait_barrier() we firstly
* increase conf->nr_pending[idx] then check conf->barrier[idx].
* A memory barrier here to make sure conf->nr_pending[idx] won't
* be fetched before conf->barrier[idx] is increased. Otherwise
* there will be a race between raise_barrier() and _wait_barrier().
*/
smp_mb__after_atomic();
/* For these conditions we must wait:
* A: while the array is in frozen state
* B: while conf->nr_pending[idx] is not 0, meaning regular I/O
* existing in corresponding I/O barrier bucket.
* C: while conf->barrier[idx] >= RESYNC_DEPTH, meaning reaches
* max resync count which allowed on current I/O barrier bucket.
*/
wait_event_lock_irq(conf->wait_barrier,
(!conf->array_frozen &&
!atomic_read(&conf->nr_pending[idx]) &&
atomic_read(&conf->barrier[idx]) < RESYNC_DEPTH) ||
test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery),
conf->resync_lock);
if (test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
atomic_dec(&conf->barrier[idx]);
spin_unlock_irq(&conf->resync_lock);
wake_up(&conf->wait_barrier);
return -EINTR;
}
atomic_inc(&conf->nr_sync_pending);
spin_unlock_irq(&conf->resync_lock);
return 0;
}
static void lower_barrier(struct r1conf *conf, sector_t sector_nr)
{
int idx = sector_to_idx(sector_nr);
BUG_ON(atomic_read(&conf->barrier[idx]) <= 0);
atomic_dec(&conf->barrier[idx]);
atomic_dec(&conf->nr_sync_pending);
wake_up(&conf->wait_barrier);
}
static bool _wait_barrier(struct r1conf *conf, int idx, bool nowait)
{
bool ret = true;
/*
* We need to increase conf->nr_pending[idx] very early here,
* then raise_barrier() can be blocked when it waits for
* conf->nr_pending[idx] to be 0. Then we can avoid holding
* conf->resync_lock when there is no barrier raised in same
* barrier unit bucket. Also if the array is frozen, I/O
* should be blocked until array is unfrozen.
*/
atomic_inc(&conf->nr_pending[idx]);
/*
* In _wait_barrier() we firstly increase conf->nr_pending[idx], then
* check conf->barrier[idx]. In raise_barrier() we firstly increase
* conf->barrier[idx], then check conf->nr_pending[idx]. A memory
* barrier is necessary here to make sure conf->barrier[idx] won't be
* fetched before conf->nr_pending[idx] is increased. Otherwise there
* will be a race between _wait_barrier() and raise_barrier().
*/
smp_mb__after_atomic();
/*
* Don't worry about checking two atomic_t variables at same time
* here. If during we check conf->barrier[idx], the array is
* frozen (conf->array_frozen is 1), and chonf->barrier[idx] is
* 0, it is safe to return and make the I/O continue. Because the
* array is frozen, all I/O returned here will eventually complete
* or be queued, no race will happen. See code comment in
* frozen_array().
*/
if (!READ_ONCE(conf->array_frozen) &&
!atomic_read(&conf->barrier[idx]))
return ret;
/*
* After holding conf->resync_lock, conf->nr_pending[idx]
* should be decreased before waiting for barrier to drop.
* Otherwise, we may encounter a race condition because
* raise_barrer() might be waiting for conf->nr_pending[idx]
* to be 0 at same time.
*/
spin_lock_irq(&conf->resync_lock);
atomic_inc(&conf->nr_waiting[idx]);
atomic_dec(&conf->nr_pending[idx]);
/*
* In case freeze_array() is waiting for
* get_unqueued_pending() == extra
*/
wake_up_barrier(conf);
/* Wait for the barrier in same barrier unit bucket to drop. */
/* Return false when nowait flag is set */
if (nowait) {
ret = false;
} else {
wait_event_lock_irq(conf->wait_barrier,
!conf->array_frozen &&
!atomic_read(&conf->barrier[idx]),
conf->resync_lock);
atomic_inc(&conf->nr_pending[idx]);
}
atomic_dec(&conf->nr_waiting[idx]);
spin_unlock_irq(&conf->resync_lock);
return ret;
}
static bool wait_read_barrier(struct r1conf *conf, sector_t sector_nr, bool nowait)
{
int idx = sector_to_idx(sector_nr);
bool ret = true;
/*
* Very similar to _wait_barrier(). The difference is, for read
* I/O we don't need wait for sync I/O, but if the whole array
* is frozen, the read I/O still has to wait until the array is
* unfrozen. Since there is no ordering requirement with
* conf->barrier[idx] here, memory barrier is unnecessary as well.
*/
atomic_inc(&conf->nr_pending[idx]);
if (!READ_ONCE(conf->array_frozen))
return ret;
spin_lock_irq(&conf->resync_lock);
atomic_inc(&conf->nr_waiting[idx]);
atomic_dec(&conf->nr_pending[idx]);
/*
* In case freeze_array() is waiting for
* get_unqueued_pending() == extra
*/
wake_up_barrier(conf);
/* Wait for array to be unfrozen */
/* Return false when nowait flag is set */
if (nowait) {
/* Return false when nowait flag is set */
ret = false;
} else {
wait_event_lock_irq(conf->wait_barrier,
!conf->array_frozen,
conf->resync_lock);
atomic_inc(&conf->nr_pending[idx]);
}
atomic_dec(&conf->nr_waiting[idx]);
spin_unlock_irq(&conf->resync_lock);
return ret;
}
static bool wait_barrier(struct r1conf *conf, sector_t sector_nr, bool nowait)
{
int idx = sector_to_idx(sector_nr);
return _wait_barrier(conf, idx, nowait);
}
static void _allow_barrier(struct r1conf *conf, int idx)
{
atomic_dec(&conf->nr_pending[idx]);
wake_up_barrier(conf);
}
static void allow_barrier(struct r1conf *conf, sector_t sector_nr)
{
int idx = sector_to_idx(sector_nr);
_allow_barrier(conf, idx);
}
/* conf->resync_lock should be held */
static int get_unqueued_pending(struct r1conf *conf)
{
int idx, ret;
ret = atomic_read(&conf->nr_sync_pending);
for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++)
ret += atomic_read(&conf->nr_pending[idx]) -
atomic_read(&conf->nr_queued[idx]);
return ret;
}
static void freeze_array(struct r1conf *conf, int extra)
{
/* Stop sync I/O and normal I/O and wait for everything to
* go quiet.
* This is called in two situations:
* 1) management command handlers (reshape, remove disk, quiesce).
* 2) one normal I/O request failed.
* After array_frozen is set to 1, new sync IO will be blocked at
* raise_barrier(), and new normal I/O will blocked at _wait_barrier()
* or wait_read_barrier(). The flying I/Os will either complete or be
* queued. When everything goes quite, there are only queued I/Os left.
* Every flying I/O contributes to a conf->nr_pending[idx], idx is the
* barrier bucket index which this I/O request hits. When all sync and
* normal I/O are queued, sum of all conf->nr_pending[] will match sum
* of all conf->nr_queued[]. But normal I/O failure is an exception,
* in handle_read_error(), we may call freeze_array() before trying to
* fix the read error. In this case, the error read I/O is not queued,
* so get_unqueued_pending() == 1.
*
* Therefore before this function returns, we need to wait until
* get_unqueued_pendings(conf) gets equal to extra. For
* normal I/O context, extra is 1, in rested situations extra is 0.
*/
spin_lock_irq(&conf->resync_lock);
conf->array_frozen = 1;
raid1_log(conf->mddev, "wait freeze");
wait_event_lock_irq_cmd(
conf->wait_barrier,
get_unqueued_pending(conf) == extra,
conf->resync_lock,
flush_pending_writes(conf));
spin_unlock_irq(&conf->resync_lock);
}
static void unfreeze_array(struct r1conf *conf)
{
/* reverse the effect of the freeze */
spin_lock_irq(&conf->resync_lock);
conf->array_frozen = 0;
spin_unlock_irq(&conf->resync_lock);
wake_up(&conf->wait_barrier);
}
static void alloc_behind_master_bio(struct r1bio *r1_bio,
struct bio *bio)
{
int size = bio->bi_iter.bi_size;
unsigned vcnt = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
int i = 0;
struct bio *behind_bio = NULL;
behind_bio = bio_alloc_bioset(NULL, vcnt, 0, GFP_NOIO,
&r1_bio->mddev->bio_set);
if (!behind_bio)
return;
/* discard op, we don't support writezero/writesame yet */
if (!bio_has_data(bio)) {
behind_bio->bi_iter.bi_size = size;
goto skip_copy;
}
while (i < vcnt && size) {
struct page *page;
int len = min_t(int, PAGE_SIZE, size);
page = alloc_page(GFP_NOIO);
if (unlikely(!page))
goto free_pages;
if (!bio_add_page(behind_bio, page, len, 0)) {
put_page(page);
goto free_pages;
}
size -= len;
i++;
}
bio_copy_data(behind_bio, bio);
skip_copy:
r1_bio->behind_master_bio = behind_bio;
set_bit(R1BIO_BehindIO, &r1_bio->state);
return;
free_pages:
pr_debug("%dB behind alloc failed, doing sync I/O\n",
bio->bi_iter.bi_size);
bio_free_pages(behind_bio);
bio_put(behind_bio);
}
static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
{
struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb,
cb);
struct mddev *mddev = plug->cb.data;
struct r1conf *conf = mddev->private;
struct bio *bio;
if (from_schedule) {
spin_lock_irq(&conf->device_lock);
bio_list_merge(&conf->pending_bio_list, &plug->pending);
spin_unlock_irq(&conf->device_lock);
wake_up_barrier(conf);
md_wakeup_thread(mddev->thread);
kfree(plug);
return;
}
/* we aren't scheduling, so we can do the write-out directly. */
bio = bio_list_get(&plug->pending);
flush_bio_list(conf, bio);
kfree(plug);
}
static void init_r1bio(struct r1bio *r1_bio, struct mddev *mddev, struct bio *bio)
{
r1_bio->master_bio = bio;
r1_bio->sectors = bio_sectors(bio);
r1_bio->state = 0;
r1_bio->mddev = mddev;
r1_bio->sector = bio->bi_iter.bi_sector;
}
static inline struct r1bio *
alloc_r1bio(struct mddev *mddev, struct bio *bio)
{
struct r1conf *conf = mddev->private;
struct r1bio *r1_bio;
r1_bio = mempool_alloc(&conf->r1bio_pool, GFP_NOIO);
/* Ensure no bio records IO_BLOCKED */
memset(r1_bio->bios, 0, conf->raid_disks * sizeof(r1_bio->bios[0]));
init_r1bio(r1_bio, mddev, bio);
return r1_bio;
}
static void raid1_read_request(struct mddev *mddev, struct bio *bio,
int max_read_sectors, struct r1bio *r1_bio)
{
struct r1conf *conf = mddev->private;
struct raid1_info *mirror;
struct bio *read_bio;
struct bitmap *bitmap = mddev->bitmap;
const enum req_op op = bio_op(bio);
const blk_opf_t do_sync = bio->bi_opf & REQ_SYNC;
int max_sectors;
int rdisk;
bool r1bio_existed = !!r1_bio;
char b[BDEVNAME_SIZE];
/*
* If r1_bio is set, we are blocking the raid1d thread
* so there is a tiny risk of deadlock. So ask for
* emergency memory if needed.
*/
gfp_t gfp = r1_bio ? (GFP_NOIO | __GFP_HIGH) : GFP_NOIO;
if (r1bio_existed) {
/* Need to get the block device name carefully */
struct md_rdev *rdev;
rcu_read_lock();
rdev = rcu_dereference(conf->mirrors[r1_bio->read_disk].rdev);
if (rdev)
snprintf(b, sizeof(b), "%pg", rdev->bdev);
else
strcpy(b, "???");
rcu_read_unlock();
}
/*
* Still need barrier for READ in case that whole
* array is frozen.
*/
if (!wait_read_barrier(conf, bio->bi_iter.bi_sector,
bio->bi_opf & REQ_NOWAIT)) {
bio_wouldblock_error(bio);
return;
}
if (!r1_bio)
r1_bio = alloc_r1bio(mddev, bio);
else
init_r1bio(r1_bio, mddev, bio);
r1_bio->sectors = max_read_sectors;
/*
* make_request() can abort the operation when read-ahead is being
* used and no empty request is available.
*/
rdisk = read_balance(conf, r1_bio, &max_sectors);
if (rdisk < 0) {
/* couldn't find anywhere to read from */
if (r1bio_existed) {
pr_crit_ratelimited("md/raid1:%s: %s: unrecoverable I/O read error for block %llu\n",
mdname(mddev),
b,
(unsigned long long)r1_bio->sector);
}
raid_end_bio_io(r1_bio);
return;
}
mirror = conf->mirrors + rdisk;
if (r1bio_existed)
pr_info_ratelimited("md/raid1:%s: redirecting sector %llu to other mirror: %pg\n",
mdname(mddev),
(unsigned long long)r1_bio->sector,
mirror->rdev->bdev);
if (test_bit(WriteMostly, &mirror->rdev->flags) &&
bitmap) {
/*
* Reading from a write-mostly device must take care not to
* over-take any writes that are 'behind'
*/
raid1_log(mddev, "wait behind writes");
wait_event(bitmap->behind_wait,
atomic_read(&bitmap->behind_writes) == 0);
}
if (max_sectors < bio_sectors(bio)) {
struct bio *split = bio_split(bio, max_sectors,
gfp, &conf->bio_split);
bio_chain(split, bio);
submit_bio_noacct(bio);
bio = split;
r1_bio->master_bio = bio;
r1_bio->sectors = max_sectors;
}
r1_bio->read_disk = rdisk;
if (!r1bio_existed) {
md_account_bio(mddev, &bio);
r1_bio->master_bio = bio;
}
read_bio = bio_alloc_clone(mirror->rdev->bdev, bio, gfp,
&mddev->bio_set);
r1_bio->bios[rdisk] = read_bio;
read_bio->bi_iter.bi_sector = r1_bio->sector +
mirror->rdev->data_offset;
read_bio->bi_end_io = raid1_end_read_request;
read_bio->bi_opf = op | do_sync;
if (test_bit(FailFast, &mirror->rdev->flags) &&
test_bit(R1BIO_FailFast, &r1_bio->state))
read_bio->bi_opf |= MD_FAILFAST;
read_bio->bi_private = r1_bio;
if (mddev->gendisk)
trace_block_bio_remap(read_bio, disk_devt(mddev->gendisk),
r1_bio->sector);
submit_bio_noacct(read_bio);
}
static void raid1_write_request(struct mddev *mddev, struct bio *bio,
int max_write_sectors)
{
struct r1conf *conf = mddev->private;
struct r1bio *r1_bio;
int i, disks;
struct bitmap *bitmap = mddev->bitmap;
unsigned long flags;
struct md_rdev *blocked_rdev;
int first_clone;
int max_sectors;
bool write_behind = false;
if (mddev_is_clustered(mddev) &&
md_cluster_ops->area_resyncing(mddev, WRITE,
bio->bi_iter.bi_sector, bio_end_sector(bio))) {
DEFINE_WAIT(w);
if (bio->bi_opf & REQ_NOWAIT) {
bio_wouldblock_error(bio);
return;
}
for (;;) {
prepare_to_wait(&conf->wait_barrier,
&w, TASK_IDLE);
if (!md_cluster_ops->area_resyncing(mddev, WRITE,
bio->bi_iter.bi_sector,
bio_end_sector(bio)))
break;
schedule();
}
finish_wait(&conf->wait_barrier, &w);
}
/*
* Register the new request and wait if the reconstruction
* thread has put up a bar for new requests.
* Continue immediately if no resync is active currently.
*/
if (!wait_barrier(conf, bio->bi_iter.bi_sector,
bio->bi_opf & REQ_NOWAIT)) {
bio_wouldblock_error(bio);
return;
}
retry_write:
r1_bio = alloc_r1bio(mddev, bio);
r1_bio->sectors = max_write_sectors;
/* first select target devices under rcu_lock and
* inc refcount on their rdev. Record them by setting
* bios[x] to bio
* If there are known/acknowledged bad blocks on any device on
* which we have seen a write error, we want to avoid writing those
* blocks.
* This potentially requires several writes to write around
* the bad blocks. Each set of writes gets it's own r1bio
* with a set of bios attached.
*/
disks = conf->raid_disks * 2;
blocked_rdev = NULL;
rcu_read_lock();
max_sectors = r1_bio->sectors;
for (i = 0; i < disks; i++) {
struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
/*
* The write-behind io is only attempted on drives marked as
* write-mostly, which means we could allocate write behind
* bio later.
*/
if (rdev && test_bit(WriteMostly, &rdev->flags))
write_behind = true;
if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
atomic_inc(&rdev->nr_pending);
blocked_rdev = rdev;
break;
}
r1_bio->bios[i] = NULL;
if (!rdev || test_bit(Faulty, &rdev->flags)) {
if (i < conf->raid_disks)
set_bit(R1BIO_Degraded, &r1_bio->state);
continue;
}
atomic_inc(&rdev->nr_pending);
if (test_bit(WriteErrorSeen, &rdev->flags)) {
sector_t first_bad;
int bad_sectors;
int is_bad;
is_bad = is_badblock(rdev, r1_bio->sector, max_sectors,
&first_bad, &bad_sectors);
if (is_bad < 0) {
/* mustn't write here until the bad block is
* acknowledged*/
set_bit(BlockedBadBlocks, &rdev->flags);
blocked_rdev = rdev;
break;
}
if (is_bad && first_bad <= r1_bio->sector) {
/* Cannot write here at all */
bad_sectors -= (r1_bio->sector - first_bad);
if (bad_sectors < max_sectors)
/* mustn't write more than bad_sectors
* to other devices yet
*/
max_sectors = bad_sectors;
rdev_dec_pending(rdev, mddev);
/* We don't set R1BIO_Degraded as that
* only applies if the disk is
* missing, so it might be re-added,
* and we want to know to recover this
* chunk.
* In this case the device is here,
* and the fact that this chunk is not
* in-sync is recorded in the bad
* block log
*/
continue;
}
if (is_bad) {
int good_sectors = first_bad - r1_bio->sector;
if (good_sectors < max_sectors)
max_sectors = good_sectors;
}
}
r1_bio->bios[i] = bio;
}
rcu_read_unlock();
if (unlikely(blocked_rdev)) {
/* Wait for this device to become unblocked */
int j;
for (j = 0; j < i; j++)
if (r1_bio->bios[j])
rdev_dec_pending(conf->mirrors[j].rdev, mddev);
free_r1bio(r1_bio);
allow_barrier(conf, bio->bi_iter.bi_sector);
if (bio->bi_opf & REQ_NOWAIT) {
bio_wouldblock_error(bio);
return;
}
raid1_log(mddev, "wait rdev %d blocked", blocked_rdev->raid_disk);
md_wait_for_blocked_rdev(blocked_rdev, mddev);
wait_barrier(conf, bio->bi_iter.bi_sector, false);
goto retry_write;
}
/*
* When using a bitmap, we may call alloc_behind_master_bio below.
* alloc_behind_master_bio allocates a copy of the data payload a page
* at a time and thus needs a new bio that can fit the whole payload
* this bio in page sized chunks.
*/
if (write_behind && bitmap)
max_sectors = min_t(int, max_sectors,
BIO_MAX_VECS * (PAGE_SIZE >> 9));
if (max_sectors < bio_sectors(bio)) {
struct bio *split = bio_split(bio, max_sectors,
GFP_NOIO, &conf->bio_split);
bio_chain(split, bio);
submit_bio_noacct(bio);
bio = split;
r1_bio->master_bio = bio;
r1_bio->sectors = max_sectors;
}
md_account_bio(mddev, &bio);
r1_bio->master_bio = bio;
atomic_set(&r1_bio->remaining, 1);
atomic_set(&r1_bio->behind_remaining, 0);
first_clone = 1;
for (i = 0; i < disks; i++) {
struct bio *mbio = NULL;
struct md_rdev *rdev = conf->mirrors[i].rdev;
if (!r1_bio->bios[i])
continue;
if (first_clone) {
/* do behind I/O ?
* Not if there are too many, or cannot
* allocate memory, or a reader on WriteMostly
* is waiting for behind writes to flush */
if (bitmap && write_behind &&
(atomic_read(&bitmap->behind_writes)
< mddev->bitmap_info.max_write_behind) &&
!waitqueue_active(&bitmap->behind_wait)) {
alloc_behind_master_bio(r1_bio, bio);
}
md_bitmap_startwrite(bitmap, r1_bio->sector, r1_bio->sectors,
test_bit(R1BIO_BehindIO, &r1_bio->state));
first_clone = 0;
}
if (r1_bio->behind_master_bio) {
mbio = bio_alloc_clone(rdev->bdev,
r1_bio->behind_master_bio,
GFP_NOIO, &mddev->bio_set);
if (test_bit(CollisionCheck, &rdev->flags))
wait_for_serialization(rdev, r1_bio);
if (test_bit(WriteMostly, &rdev->flags))
atomic_inc(&r1_bio->behind_remaining);
} else {
mbio = bio_alloc_clone(rdev->bdev, bio, GFP_NOIO,
&mddev->bio_set);
if (mddev->serialize_policy)
wait_for_serialization(rdev, r1_bio);
}
r1_bio->bios[i] = mbio;
mbio->bi_iter.bi_sector = (r1_bio->sector + rdev->data_offset);
mbio->bi_end_io = raid1_end_write_request;
mbio->bi_opf = bio_op(bio) | (bio->bi_opf & (REQ_SYNC | REQ_FUA));
if (test_bit(FailFast, &rdev->flags) &&
!test_bit(WriteMostly, &rdev->flags) &&
conf->raid_disks - mddev->degraded > 1)
mbio->bi_opf |= MD_FAILFAST;
mbio->bi_private = r1_bio;
atomic_inc(&r1_bio->remaining);
if (mddev->gendisk)
trace_block_bio_remap(mbio, disk_devt(mddev->gendisk),
r1_bio->sector);
/* flush_pending_writes() needs access to the rdev so...*/
mbio->bi_bdev = (void *)rdev;
if (!raid1_add_bio_to_plug(mddev, mbio, raid1_unplug, disks)) {
spin_lock_irqsave(&conf->device_lock, flags);
bio_list_add(&conf->pending_bio_list, mbio);
spin_unlock_irqrestore(&conf->device_lock, flags);
md_wakeup_thread(mddev->thread);
}
}
r1_bio_write_done(r1_bio);
/* In case raid1d snuck in to freeze_array */
wake_up_barrier(conf);
}
static bool raid1_make_request(struct mddev *mddev, struct bio *bio)
{
sector_t sectors;
if (unlikely(bio->bi_opf & REQ_PREFLUSH)
&& md_flush_request(mddev, bio))
return true;
/*
* There is a limit to the maximum size, but
* the read/write handler might find a lower limit
* due to bad blocks. To avoid multiple splits,
* we pass the maximum number of sectors down
* and let the lower level perform the split.
*/
sectors = align_to_barrier_unit_end(
bio->bi_iter.bi_sector, bio_sectors(bio));
if (bio_data_dir(bio) == READ)
raid1_read_request(mddev, bio, sectors, NULL);
else {
if (!md_write_start(mddev,bio))
return false;
raid1_write_request(mddev, bio, sectors);
}
return true;
}
static void raid1_status(struct seq_file *seq, struct mddev *mddev)
{
struct r1conf *conf = mddev->private;
int i;
seq_printf(seq, " [%d/%d] [", conf->raid_disks,
conf->raid_disks - mddev->degraded);
rcu_read_lock();
for (i = 0; i < conf->raid_disks; i++) {
struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
seq_printf(seq, "%s",
rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
}
rcu_read_unlock();
seq_printf(seq, "]");
}
/**
* raid1_error() - RAID1 error handler.
* @mddev: affected md device.
* @rdev: member device to fail.
*
* The routine acknowledges &rdev failure and determines new @mddev state.
* If it failed, then:
* - &MD_BROKEN flag is set in &mddev->flags.
* - recovery is disabled.
* Otherwise, it must be degraded:
* - recovery is interrupted.
* - &mddev->degraded is bumped.
*
* @rdev is marked as &Faulty excluding case when array is failed and
* &mddev->fail_last_dev is off.
*/
static void raid1_error(struct mddev *mddev, struct md_rdev *rdev)
{
struct r1conf *conf = mddev->private;
unsigned long flags;
spin_lock_irqsave(&conf->device_lock, flags);
if (test_bit(In_sync, &rdev->flags) &&
(conf->raid_disks - mddev->degraded) == 1) {
set_bit(MD_BROKEN, &mddev->flags);
if (!mddev->fail_last_dev) {
conf->recovery_disabled = mddev->recovery_disabled;
spin_unlock_irqrestore(&conf->device_lock, flags);
return;
}
}
set_bit(Blocked, &rdev->flags);
if (test_and_clear_bit(In_sync, &rdev->flags))
mddev->degraded++;
set_bit(Faulty, &rdev->flags);
spin_unlock_irqrestore(&conf->device_lock, flags);
/*
* if recovery is running, make sure it aborts.
*/
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
set_mask_bits(&mddev->sb_flags, 0,
BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
pr_crit("md/raid1:%s: Disk failure on %pg, disabling device.\n"
"md/raid1:%s: Operation continuing on %d devices.\n",
mdname(mddev), rdev->bdev,
mdname(mddev), conf->raid_disks - mddev->degraded);
}
static void print_conf(struct r1conf *conf)
{
int i;
pr_debug("RAID1 conf printout:\n");
if (!conf) {
pr_debug("(!conf)\n");
return;
}
pr_debug(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
conf->raid_disks);
rcu_read_lock();
for (i = 0; i < conf->raid_disks; i++) {
struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
if (rdev)
pr_debug(" disk %d, wo:%d, o:%d, dev:%pg\n",
i, !test_bit(In_sync, &rdev->flags),
!test_bit(Faulty, &rdev->flags),
rdev->bdev);
}
rcu_read_unlock();
}
static void close_sync(struct r1conf *conf)
{
int idx;
for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++) {
_wait_barrier(conf, idx, false);
_allow_barrier(conf, idx);
}
mempool_exit(&conf->r1buf_pool);
}
static int raid1_spare_active(struct mddev *mddev)
{
int i;
struct r1conf *conf = mddev->private;
int count = 0;
unsigned long flags;
/*
* Find all failed disks within the RAID1 configuration
* and mark them readable.
* Called under mddev lock, so rcu protection not needed.
* device_lock used to avoid races with raid1_end_read_request
* which expects 'In_sync' flags and ->degraded to be consistent.
*/
spin_lock_irqsave(&conf->device_lock, flags);
for (i = 0; i < conf->raid_disks; i++) {
struct md_rdev *rdev = conf->mirrors[i].rdev;
struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev;
if (repl
&& !test_bit(Candidate, &repl->flags)
&& repl->recovery_offset == MaxSector
&& !test_bit(Faulty, &repl->flags)
&& !test_and_set_bit(In_sync, &repl->flags)) {
/* replacement has just become active */
if (!rdev ||
!test_and_clear_bit(In_sync, &rdev->flags))
count++;
if (rdev) {
/* Replaced device not technically
* faulty, but we need to be sure
* it gets removed and never re-added
*/
set_bit(Faulty, &rdev->flags);
sysfs_notify_dirent_safe(
rdev->sysfs_state);
}
}
if (rdev
&& rdev->recovery_offset == MaxSector
&& !test_bit(Faulty, &rdev->flags)
&& !test_and_set_bit(In_sync, &rdev->flags)) {
count++;
sysfs_notify_dirent_safe(rdev->sysfs_state);
}
}
mddev->degraded -= count;
spin_unlock_irqrestore(&conf->device_lock, flags);
print_conf(conf);
return count;
}
static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
{
struct r1conf *conf = mddev->private;
int err = -EEXIST;
int mirror = 0, repl_slot = -1;
struct raid1_info *p;
int first = 0;
int last = conf->raid_disks - 1;
if (mddev->recovery_disabled == conf->recovery_disabled)
return -EBUSY;
if (md_integrity_add_rdev(rdev, mddev))
return -ENXIO;
if (rdev->raid_disk >= 0)
first = last = rdev->raid_disk;
/*
* find the disk ... but prefer rdev->saved_raid_disk
* if possible.
*/
if (rdev->saved_raid_disk >= 0 &&
rdev->saved_raid_disk >= first &&
rdev->saved_raid_disk < conf->raid_disks &&
conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
first = last = rdev->saved_raid_disk;
for (mirror = first; mirror <= last; mirror++) {
p = conf->mirrors + mirror;
if (!p->rdev) {
if (mddev->gendisk)
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
p->head_position = 0;
rdev->raid_disk = mirror;
err = 0;
/* As all devices are equivalent, we don't need a full recovery
* if this was recently any drive of the array
*/
if (rdev->saved_raid_disk < 0)
conf->fullsync = 1;
rcu_assign_pointer(p->rdev, rdev);
break;
}
if (test_bit(WantReplacement, &p->rdev->flags) &&
p[conf->raid_disks].rdev == NULL && repl_slot < 0)
repl_slot = mirror;
}
if (err && repl_slot >= 0) {
/* Add this device as a replacement */
p = conf->mirrors + repl_slot;
clear_bit(In_sync, &rdev->flags);
set_bit(Replacement, &rdev->flags);
rdev->raid_disk = repl_slot;
err = 0;
conf->fullsync = 1;
rcu_assign_pointer(p[conf->raid_disks].rdev, rdev);
}
print_conf(conf);
return err;
}
static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
{
struct r1conf *conf = mddev->private;
int err = 0;
int number = rdev->raid_disk;
struct raid1_info *p = conf->mirrors + number;
if (unlikely(number >= conf->raid_disks))
goto abort;
if (rdev != p->rdev)
p = conf->mirrors + conf->raid_disks + number;
print_conf(conf);
if (rdev == p->rdev) {
if (test_bit(In_sync, &rdev->flags) ||
atomic_read(&rdev->nr_pending)) {
err = -EBUSY;
goto abort;
}
/* Only remove non-faulty devices if recovery
* is not possible.
*/
if (!test_bit(Faulty, &rdev->flags) &&
mddev->recovery_disabled != conf->recovery_disabled &&
mddev->degraded < conf->raid_disks) {
err = -EBUSY;
goto abort;
}
p->rdev = NULL;
if (!test_bit(RemoveSynchronized, &rdev->flags)) {
synchronize_rcu();
if (atomic_read(&rdev->nr_pending)) {
/* lost the race, try later */
err = -EBUSY;
p->rdev = rdev;
goto abort;
}
}
if (conf->mirrors[conf->raid_disks + number].rdev) {
/* We just removed a device that is being replaced.
* Move down the replacement. We drain all IO before
* doing this to avoid confusion.
*/
struct md_rdev *repl =
conf->mirrors[conf->raid_disks + number].rdev;
freeze_array(conf, 0);
if (atomic_read(&repl->nr_pending)) {
/* It means that some queued IO of retry_list
* hold repl. Thus, we cannot set replacement
* as NULL, avoiding rdev NULL pointer
* dereference in sync_request_write and
* handle_write_finished.
*/
err = -EBUSY;
unfreeze_array(conf);
goto abort;
}
clear_bit(Replacement, &repl->flags);
p->rdev = repl;
conf->mirrors[conf->raid_disks + number].rdev = NULL;
unfreeze_array(conf);
}
clear_bit(WantReplacement, &rdev->flags);
err = md_integrity_register(mddev);
}
abort:
print_conf(conf);
return err;
}
static void end_sync_read(struct bio *bio)
{
struct r1bio *r1_bio = get_resync_r1bio(bio);
update_head_pos(r1_bio->read_disk, r1_bio);
/*
* we have read a block, now it needs to be re-written,
* or re-read if the read failed.
* We don't do much here, just schedule handling by raid1d
*/
if (!bio->bi_status)
set_bit(R1BIO_Uptodate, &r1_bio->state);
if (atomic_dec_and_test(&r1_bio->remaining))
reschedule_retry(r1_bio);
}
static void abort_sync_write(struct mddev *mddev, struct r1bio *r1_bio)
{
sector_t sync_blocks = 0;
sector_t s = r1_bio->sector;
long sectors_to_go = r1_bio->sectors;
/* make sure these bits don't get cleared. */
do {
md_bitmap_end_sync(mddev->bitmap, s, &sync_blocks, 1);
s += sync_blocks;
sectors_to_go -= sync_blocks;
} while (sectors_to_go > 0);
}
static void put_sync_write_buf(struct r1bio *r1_bio, int uptodate)
{
if (atomic_dec_and_test(&r1_bio->remaining)) {
struct mddev *mddev = r1_bio->mddev;
int s = r1_bio->sectors;
if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
test_bit(R1BIO_WriteError, &r1_bio->state))
reschedule_retry(r1_bio);
else {
put_buf(r1_bio);
md_done_sync(mddev, s, uptodate);
}
}
}
static void end_sync_write(struct bio *bio)
{
int uptodate = !bio->bi_status;
struct r1bio *r1_bio = get_resync_r1bio(bio);
struct mddev *mddev = r1_bio->mddev;
struct r1conf *conf = mddev->private;
sector_t first_bad;
int bad_sectors;
struct md_rdev *rdev = conf->mirrors[find_bio_disk(r1_bio, bio)].rdev;
if (!uptodate) {
abort_sync_write(mddev, r1_bio);
set_bit(WriteErrorSeen, &rdev->flags);
if (!test_and_set_bit(WantReplacement, &rdev->flags))
set_bit(MD_RECOVERY_NEEDED, &
mddev->recovery);
set_bit(R1BIO_WriteError, &r1_bio->state);
} else if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors,
&first_bad, &bad_sectors) &&
!is_badblock(conf->mirrors[r1_bio->read_disk].rdev,
r1_bio->sector,
r1_bio->sectors,
&first_bad, &bad_sectors)
)
set_bit(R1BIO_MadeGood, &r1_bio->state);
put_sync_write_buf(r1_bio, uptodate);
}
static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector,
int sectors, struct page *page, int rw)
{
if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
/* success */
return 1;
if (rw == WRITE) {
set_bit(WriteErrorSeen, &rdev->flags);
if (!test_and_set_bit(WantReplacement,
&rdev->flags))
set_bit(MD_RECOVERY_NEEDED, &
rdev->mddev->recovery);
}
/* need to record an error - either for the block or the device */
if (!rdev_set_badblocks(rdev, sector, sectors, 0))
md_error(rdev->mddev, rdev);
return 0;
}
static int fix_sync_read_error(struct r1bio *r1_bio)
{
/* Try some synchronous reads of other devices to get
* good data, much like with normal read errors. Only
* read into the pages we already have so we don't
* need to re-issue the read request.
* We don't need to freeze the array, because being in an
* active sync request, there is no normal IO, and
* no overlapping syncs.
* We don't need to check is_badblock() again as we
* made sure that anything with a bad block in range
* will have bi_end_io clear.
*/
struct mddev *mddev = r1_bio->mddev;
struct r1conf *conf = mddev->private;
struct bio *bio = r1_bio->bios[r1_bio->read_disk];
struct page **pages = get_resync_pages(bio)->pages;
sector_t sect = r1_bio->sector;
int sectors = r1_bio->sectors;
int idx = 0;
struct md_rdev *rdev;
rdev = conf->mirrors[r1_bio->read_disk].rdev;
if (test_bit(FailFast, &rdev->flags)) {
/* Don't try recovering from here - just fail it
* ... unless it is the last working device of course */
md_error(mddev, rdev);
if (test_bit(Faulty, &rdev->flags))
/* Don't try to read from here, but make sure
* put_buf does it's thing
*/
bio->bi_end_io = end_sync_write;
}
while(sectors) {
int s = sectors;
int d = r1_bio->read_disk;
int success = 0;
int start;
if (s > (PAGE_SIZE>>9))
s = PAGE_SIZE >> 9;
do {
if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
/* No rcu protection needed here devices
* can only be removed when no resync is
* active, and resync is currently active
*/
rdev = conf->mirrors[d].rdev;
if (sync_page_io(rdev, sect, s<<9,
pages[idx],
REQ_OP_READ, false)) {
success = 1;
break;
}
}
d++;
if (d == conf->raid_disks * 2)
d = 0;
} while (!success && d != r1_bio->read_disk);
if (!success) {
int abort = 0;
/* Cannot read from anywhere, this block is lost.
* Record a bad block on each device. If that doesn't
* work just disable and interrupt the recovery.
* Don't fail devices as that won't really help.
*/
pr_crit_ratelimited("md/raid1:%s: %pg: unrecoverable I/O read error for block %llu\n",
mdname(mddev), bio->bi_bdev,
(unsigned long long)r1_bio->sector);
for (d = 0; d < conf->raid_disks * 2; d++) {
rdev = conf->mirrors[d].rdev;
if (!rdev || test_bit(Faulty, &rdev->flags))
continue;
if (!rdev_set_badblocks(rdev, sect, s, 0))
abort = 1;
}
if (abort) {
conf->recovery_disabled =
mddev->recovery_disabled;
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
md_done_sync(mddev, r1_bio->sectors, 0);
put_buf(r1_bio);
return 0;
}
/* Try next page */
sectors -= s;
sect += s;
idx++;
continue;
}
start = d;
/* write it back and re-read */
while (d != r1_bio->read_disk) {
if (d == 0)
d = conf->raid_disks * 2;
d--;
if (r1_bio->bios[d]->bi_end_io != end_sync_read)
continue;
rdev = conf->mirrors[d].rdev;
if (r1_sync_page_io(rdev, sect, s,
pages[idx],
WRITE) == 0) {
r1_bio->bios[d]->bi_end_io = NULL;
rdev_dec_pending(rdev, mddev);
}
}
d = start;
while (d != r1_bio->read_disk) {
if (d == 0)
d = conf->raid_disks * 2;
d--;
if (r1_bio->bios[d]->bi_end_io != end_sync_read)
continue;
rdev = conf->mirrors[d].rdev;
if (r1_sync_page_io(rdev, sect, s,
pages[idx],
READ) != 0)
atomic_add(s, &rdev->corrected_errors);
}
sectors -= s;
sect += s;
idx ++;
}
set_bit(R1BIO_Uptodate, &r1_bio->state);
bio->bi_status = 0;
return 1;
}
static void process_checks(struct r1bio *r1_bio)
{
/* We have read all readable devices. If we haven't
* got the block, then there is no hope left.
* If we have, then we want to do a comparison
* and skip the write if everything is the same.
* If any blocks failed to read, then we need to
* attempt an over-write
*/
struct mddev *mddev = r1_bio->mddev;
struct r1conf *conf = mddev->private;
int primary;
int i;
int vcnt;
/* Fix variable parts of all bios */
vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
for (i = 0; i < conf->raid_disks * 2; i++) {
blk_status_t status;
struct bio *b = r1_bio->bios[i];
struct resync_pages *rp = get_resync_pages(b);
if (b->bi_end_io != end_sync_read)
continue;
/* fixup the bio for reuse, but preserve errno */
status = b->bi_status;
bio_reset(b, conf->mirrors[i].rdev->bdev, REQ_OP_READ);
b->bi_status = status;
b->bi_iter.bi_sector = r1_bio->sector +
conf->mirrors[i].rdev->data_offset;
b->bi_end_io = end_sync_read;
rp->raid_bio = r1_bio;
b->bi_private = rp;
/* initialize bvec table again */
md_bio_reset_resync_pages(b, rp, r1_bio->sectors << 9);
}
for (primary = 0; primary < conf->raid_disks * 2; primary++)
if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
!r1_bio->bios[primary]->bi_status) {
r1_bio->bios[primary]->bi_end_io = NULL;
rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
break;
}
r1_bio->read_disk = primary;
for (i = 0; i < conf->raid_disks * 2; i++) {
int j = 0;
struct bio *pbio = r1_bio->bios[primary];
struct bio *sbio = r1_bio->bios[i];
blk_status_t status = sbio->bi_status;
struct page **ppages = get_resync_pages(pbio)->pages;
struct page **spages = get_resync_pages(sbio)->pages;
struct bio_vec *bi;
int page_len[RESYNC_PAGES] = { 0 };
struct bvec_iter_all iter_all;
if (sbio->bi_end_io != end_sync_read)
continue;
/* Now we can 'fixup' the error value */
sbio->bi_status = 0;
bio_for_each_segment_all(bi, sbio, iter_all)
page_len[j++] = bi->bv_len;
if (!status) {
for (j = vcnt; j-- ; ) {
if (memcmp(page_address(ppages[j]),
page_address(spages[j]),
page_len[j]))
break;
}
} else
j = 0;
if (j >= 0)
atomic64_add(r1_bio->sectors, &mddev->resync_mismatches);
if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
&& !status)) {
/* No need to write to this device. */
sbio->bi_end_io = NULL;
rdev_dec_pending(conf->mirrors[i].rdev, mddev);
continue;
}
bio_copy_data(sbio, pbio);
}
}
static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio)
{
struct r1conf *conf = mddev->private;
int i;
int disks = conf->raid_disks * 2;
struct bio *wbio;
if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
/* ouch - failed to read all of that. */
if (!fix_sync_read_error(r1_bio))
return;
if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
process_checks(r1_bio);
/*
* schedule writes
*/
atomic_set(&r1_bio->remaining, 1);
for (i = 0; i < disks ; i++) {
wbio = r1_bio->bios[i];
if (wbio->bi_end_io == NULL ||
(wbio->bi_end_io == end_sync_read &&
(i == r1_bio->read_disk ||
!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
continue;
if (test_bit(Faulty, &conf->mirrors[i].rdev->flags)) {
abort_sync_write(mddev, r1_bio);
continue;
}
wbio->bi_opf = REQ_OP_WRITE;
if (test_bit(FailFast, &conf->mirrors[i].rdev->flags))
wbio->bi_opf |= MD_FAILFAST;
wbio->bi_end_io = end_sync_write;
atomic_inc(&r1_bio->remaining);
md_sync_acct(conf->mirrors[i].rdev->bdev, bio_sectors(wbio));
submit_bio_noacct(wbio);
}
put_sync_write_buf(r1_bio, 1);
}
/*
* This is a kernel thread which:
*
* 1. Retries failed read operations on working mirrors.
* 2. Updates the raid superblock when problems encounter.
* 3. Performs writes following reads for array synchronising.
*/
static void fix_read_error(struct r1conf *conf, int read_disk,
sector_t sect, int sectors)
{
struct mddev *mddev = conf->mddev;
while(sectors) {
int s = sectors;
int d = read_disk;
int success = 0;
int start;
struct md_rdev *rdev;
if (s > (PAGE_SIZE>>9))
s = PAGE_SIZE >> 9;
do {
sector_t first_bad;
int bad_sectors;
rcu_read_lock();
rdev = rcu_dereference(conf->mirrors[d].rdev);
if (rdev &&
(test_bit(In_sync, &rdev->flags) ||
(!test_bit(Faulty, &rdev->flags) &&
rdev->recovery_offset >= sect + s)) &&
is_badblock(rdev, sect, s,
&first_bad, &bad_sectors) == 0) {
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
if (sync_page_io(rdev, sect, s<<9,
conf->tmppage, REQ_OP_READ, false))
success = 1;
rdev_dec_pending(rdev, mddev);
if (success)
break;
} else
rcu_read_unlock();
d++;
if (d == conf->raid_disks * 2)
d = 0;
} while (d != read_disk);
if (!success) {
/* Cannot read from anywhere - mark it bad */
struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
if (!rdev_set_badblocks(rdev, sect, s, 0))
md_error(mddev, rdev);
break;
}
/* write it back and re-read */
start = d;
while (d != read_disk) {
if (d==0)
d = conf->raid_disks * 2;
d--;
rcu_read_lock();
rdev = rcu_dereference(conf->mirrors[d].rdev);
if (rdev &&
!test_bit(Faulty, &rdev->flags)) {
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
r1_sync_page_io(rdev, sect, s,
conf->tmppage, WRITE);
rdev_dec_pending(rdev, mddev);
} else
rcu_read_unlock();
}
d = start;
while (d != read_disk) {
if (d==0)
d = conf->raid_disks * 2;
d--;
rcu_read_lock();
rdev = rcu_dereference(conf->mirrors[d].rdev);
if (rdev &&
!test_bit(Faulty, &rdev->flags)) {
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
if (r1_sync_page_io(rdev, sect, s,
conf->tmppage, READ)) {
atomic_add(s, &rdev->corrected_errors);
pr_info("md/raid1:%s: read error corrected (%d sectors at %llu on %pg)\n",
mdname(mddev), s,
(unsigned long long)(sect +
rdev->data_offset),
rdev->bdev);
}
rdev_dec_pending(rdev, mddev);
} else
rcu_read_unlock();
}
sectors -= s;
sect += s;
}
}
static int narrow_write_error(struct r1bio *r1_bio, int i)
{
struct mddev *mddev = r1_bio->mddev;
struct r1conf *conf = mddev->private;
struct md_rdev *rdev = conf->mirrors[i].rdev;
/* bio has the data to be written to device 'i' where
* we just recently had a write error.
* We repeatedly clone the bio and trim down to one block,
* then try the write. Where the write fails we record
* a bad block.
* It is conceivable that the bio doesn't exactly align with
* blocks. We must handle this somehow.
*
* We currently own a reference on the rdev.
*/
int block_sectors;
sector_t sector;
int sectors;
int sect_to_write = r1_bio->sectors;
int ok = 1;
if (rdev->badblocks.shift < 0)
return 0;
block_sectors = roundup(1 << rdev->badblocks.shift,
bdev_logical_block_size(rdev->bdev) >> 9);
sector = r1_bio->sector;
sectors = ((sector + block_sectors)
& ~(sector_t)(block_sectors - 1))
- sector;
while (sect_to_write) {
struct bio *wbio;
if (sectors > sect_to_write)
sectors = sect_to_write;
/* Write at 'sector' for 'sectors'*/
if (test_bit(R1BIO_BehindIO, &r1_bio->state)) {
wbio = bio_alloc_clone(rdev->bdev,
r1_bio->behind_master_bio,
GFP_NOIO, &mddev->bio_set);
} else {
wbio = bio_alloc_clone(rdev->bdev, r1_bio->master_bio,
GFP_NOIO, &mddev->bio_set);
}
wbio->bi_opf = REQ_OP_WRITE;
wbio->bi_iter.bi_sector = r1_bio->sector;
wbio->bi_iter.bi_size = r1_bio->sectors << 9;
bio_trim(wbio, sector - r1_bio->sector, sectors);
wbio->bi_iter.bi_sector += rdev->data_offset;
if (submit_bio_wait(wbio) < 0)
/* failure! */
ok = rdev_set_badblocks(rdev, sector,
sectors, 0)
&& ok;
bio_put(wbio);
sect_to_write -= sectors;
sector += sectors;
sectors = block_sectors;
}
return ok;
}
static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
{
int m;
int s = r1_bio->sectors;
for (m = 0; m < conf->raid_disks * 2 ; m++) {
struct md_rdev *rdev = conf->mirrors[m].rdev;
struct bio *bio = r1_bio->bios[m];
if (bio->bi_end_io == NULL)
continue;
if (!bio->bi_status &&
test_bit(R1BIO_MadeGood, &r1_bio->state)) {
rdev_clear_badblocks(rdev, r1_bio->sector, s, 0);
}
if (bio->bi_status &&
test_bit(R1BIO_WriteError, &r1_bio->state)) {
if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0))
md_error(conf->mddev, rdev);
}
}
put_buf(r1_bio);
md_done_sync(conf->mddev, s, 1);
}
static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
{
int m, idx;
bool fail = false;
for (m = 0; m < conf->raid_disks * 2 ; m++)
if (r1_bio->bios[m] == IO_MADE_GOOD) {
struct md_rdev *rdev = conf->mirrors[m].rdev;
rdev_clear_badblocks(rdev,
r1_bio->sector,
r1_bio->sectors, 0);
rdev_dec_pending(rdev, conf->mddev);
} else if (r1_bio->bios[m] != NULL) {
/* This drive got a write error. We need to
* narrow down and record precise write
* errors.
*/
fail = true;
if (!narrow_write_error(r1_bio, m)) {
md_error(conf->mddev,
conf->mirrors[m].rdev);
/* an I/O failed, we can't clear the bitmap */
set_bit(R1BIO_Degraded, &r1_bio->state);
}
rdev_dec_pending(conf->mirrors[m].rdev,
conf->mddev);
}
if (fail) {
spin_lock_irq(&conf->device_lock);
list_add(&r1_bio->retry_list, &conf->bio_end_io_list);
idx = sector_to_idx(r1_bio->sector);
atomic_inc(&conf->nr_queued[idx]);
spin_unlock_irq(&conf->device_lock);
/*
* In case freeze_array() is waiting for condition
* get_unqueued_pending() == extra to be true.
*/
wake_up(&conf->wait_barrier);
md_wakeup_thread(conf->mddev->thread);
} else {
if (test_bit(R1BIO_WriteError, &r1_bio->state))
close_write(r1_bio);
raid_end_bio_io(r1_bio);
}
}
static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
{
struct mddev *mddev = conf->mddev;
struct bio *bio;
struct md_rdev *rdev;
sector_t sector;
clear_bit(R1BIO_ReadError, &r1_bio->state);
/* we got a read error. Maybe the drive is bad. Maybe just
* the block and we can fix it.
* We freeze all other IO, and try reading the block from
* other devices. When we find one, we re-write
* and check it that fixes the read error.
* This is all done synchronously while the array is
* frozen
*/
bio = r1_bio->bios[r1_bio->read_disk];
bio_put(bio);
r1_bio->bios[r1_bio->read_disk] = NULL;
rdev = conf->mirrors[r1_bio->read_disk].rdev;
if (mddev->ro == 0
&& !test_bit(FailFast, &rdev->flags)) {
freeze_array(conf, 1);
fix_read_error(conf, r1_bio->read_disk,
r1_bio->sector, r1_bio->sectors);
unfreeze_array(conf);
} else if (mddev->ro == 0 && test_bit(FailFast, &rdev->flags)) {
md_error(mddev, rdev);
} else {
r1_bio->bios[r1_bio->read_disk] = IO_BLOCKED;
}
rdev_dec_pending(rdev, conf->mddev);
sector = r1_bio->sector;
bio = r1_bio->master_bio;
/* Reuse the old r1_bio so that the IO_BLOCKED settings are preserved */
r1_bio->state = 0;
raid1_read_request(mddev, bio, r1_bio->sectors, r1_bio);
allow_barrier(conf, sector);
}
static void raid1d(struct md_thread *thread)
{
struct mddev *mddev = thread->mddev;
struct r1bio *r1_bio;
unsigned long flags;
struct r1conf *conf = mddev->private;
struct list_head *head = &conf->retry_list;
struct blk_plug plug;
int idx;
md_check_recovery(mddev);
if (!list_empty_careful(&conf->bio_end_io_list) &&
!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
LIST_HEAD(tmp);
spin_lock_irqsave(&conf->device_lock, flags);
if (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags))
list_splice_init(&conf->bio_end_io_list, &tmp);
spin_unlock_irqrestore(&conf->device_lock, flags);
while (!list_empty(&tmp)) {
r1_bio = list_first_entry(&tmp, struct r1bio,
retry_list);
list_del(&r1_bio->retry_list);
idx = sector_to_idx(r1_bio->sector);
atomic_dec(&conf->nr_queued[idx]);
if (mddev->degraded)
set_bit(R1BIO_Degraded, &r1_bio->state);
if (test_bit(R1BIO_WriteError, &r1_bio->state))
close_write(r1_bio);
raid_end_bio_io(r1_bio);
}
}
blk_start_plug(&plug);
for (;;) {
flush_pending_writes(conf);
spin_lock_irqsave(&conf->device_lock, flags);
if (list_empty(head)) {
spin_unlock_irqrestore(&conf->device_lock, flags);
break;
}
r1_bio = list_entry(head->prev, struct r1bio, retry_list);
list_del(head->prev);
idx = sector_to_idx(r1_bio->sector);
atomic_dec(&conf->nr_queued[idx]);
spin_unlock_irqrestore(&conf->device_lock, flags);
mddev = r1_bio->mddev;
conf = mddev->private;
if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
test_bit(R1BIO_WriteError, &r1_bio->state))
handle_sync_write_finished(conf, r1_bio);
else
sync_request_write(mddev, r1_bio);
} else if (test_bit(R1BIO_MadeGood, &r1_bio->state) ||
test_bit(R1BIO_WriteError, &r1_bio->state))
handle_write_finished(conf, r1_bio);
else if (test_bit(R1BIO_ReadError, &r1_bio->state))
handle_read_error(conf, r1_bio);
else
WARN_ON_ONCE(1);
cond_resched();
if (mddev->sb_flags & ~(1<<MD_SB_CHANGE_PENDING))
md_check_recovery(mddev);
}
blk_finish_plug(&plug);
}
static int init_resync(struct r1conf *conf)
{
int buffs;
buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
BUG_ON(mempool_initialized(&conf->r1buf_pool));
return mempool_init(&conf->r1buf_pool, buffs, r1buf_pool_alloc,
r1buf_pool_free, conf->poolinfo);
}
static struct r1bio *raid1_alloc_init_r1buf(struct r1conf *conf)
{
struct r1bio *r1bio = mempool_alloc(&conf->r1buf_pool, GFP_NOIO);
struct resync_pages *rps;
struct bio *bio;
int i;
for (i = conf->poolinfo->raid_disks; i--; ) {
bio = r1bio->bios[i];
rps = bio->bi_private;
bio_reset(bio, NULL, 0);
bio->bi_private = rps;
}
r1bio->master_bio = NULL;
return r1bio;
}
/*
* perform a "sync" on one "block"
*
* We need to make sure that no normal I/O request - particularly write
* requests - conflict with active sync requests.
*
* This is achieved by tracking pending requests and a 'barrier' concept
* that can be installed to exclude normal IO requests.
*/
static sector_t raid1_sync_request(struct mddev *mddev, sector_t sector_nr,
int *skipped)
{
struct r1conf *conf = mddev->private;
struct r1bio *r1_bio;
struct bio *bio;
sector_t max_sector, nr_sectors;
int disk = -1;
int i;
int wonly = -1;
int write_targets = 0, read_targets = 0;
sector_t sync_blocks;
int still_degraded = 0;
int good_sectors = RESYNC_SECTORS;
int min_bad = 0; /* number of sectors that are bad in all devices */
int idx = sector_to_idx(sector_nr);
int page_idx = 0;
if (!mempool_initialized(&conf->r1buf_pool))
if (init_resync(conf))
return 0;
max_sector = mddev->dev_sectors;
if (sector_nr >= max_sector) {
/* If we aborted, we need to abort the
* sync on the 'current' bitmap chunk (there will
* only be one in raid1 resync.
* We can find the current addess in mddev->curr_resync
*/
if (mddev->curr_resync < max_sector) /* aborted */
md_bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
&sync_blocks, 1);
else /* completed sync */
conf->fullsync = 0;
md_bitmap_close_sync(mddev->bitmap);
close_sync(conf);
if (mddev_is_clustered(mddev)) {
conf->cluster_sync_low = 0;
conf->cluster_sync_high = 0;
}
return 0;
}
if (mddev->bitmap == NULL &&
mddev->recovery_cp == MaxSector &&
!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
conf->fullsync == 0) {
*skipped = 1;
return max_sector - sector_nr;
}
/* before building a request, check if we can skip these blocks..
* This call the bitmap_start_sync doesn't actually record anything
*/
if (!md_bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
!conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
/* We can skip this block, and probably several more */
*skipped = 1;
return sync_blocks;
}
/*
* If there is non-resync activity waiting for a turn, then let it
* though before starting on this new sync request.
*/
if (atomic_read(&conf->nr_waiting[idx]))
schedule_timeout_uninterruptible(1);
/* we are incrementing sector_nr below. To be safe, we check against
* sector_nr + two times RESYNC_SECTORS
*/
md_bitmap_cond_end_sync(mddev->bitmap, sector_nr,
mddev_is_clustered(mddev) && (sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high));
if (raise_barrier(conf, sector_nr))
return 0;
r1_bio = raid1_alloc_init_r1buf(conf);
rcu_read_lock();
/*
* If we get a correctably read error during resync or recovery,
* we might want to read from a different device. So we
* flag all drives that could conceivably be read from for READ,
* and any others (which will be non-In_sync devices) for WRITE.
* If a read fails, we try reading from something else for which READ
* is OK.
*/
r1_bio->mddev = mddev;
r1_bio->sector = sector_nr;
r1_bio->state = 0;
set_bit(R1BIO_IsSync, &r1_bio->state);
/* make sure good_sectors won't go across barrier unit boundary */
good_sectors = align_to_barrier_unit_end(sector_nr, good_sectors);
for (i = 0; i < conf->raid_disks * 2; i++) {
struct md_rdev *rdev;
bio = r1_bio->bios[i];
rdev = rcu_dereference(conf->mirrors[i].rdev);
if (rdev == NULL ||
test_bit(Faulty, &rdev->flags)) {
if (i < conf->raid_disks)
still_degraded = 1;
} else if (!test_bit(In_sync, &rdev->flags)) {
bio->bi_opf = REQ_OP_WRITE;
bio->bi_end_io = end_sync_write;
write_targets ++;
} else {
/* may need to read from here */
sector_t first_bad = MaxSector;
int bad_sectors;
if (is_badblock(rdev, sector_nr, good_sectors,
&first_bad, &bad_sectors)) {
if (first_bad > sector_nr)
good_sectors = first_bad - sector_nr;
else {
bad_sectors -= (sector_nr - first_bad);
if (min_bad == 0 ||
min_bad > bad_sectors)
min_bad = bad_sectors;
}
}
if (sector_nr < first_bad) {
if (test_bit(WriteMostly, &rdev->flags)) {
if (wonly < 0)
wonly = i;
} else {
if (disk < 0)
disk = i;
}
bio->bi_opf = REQ_OP_READ;
bio->bi_end_io = end_sync_read;
read_targets++;
} else if (!test_bit(WriteErrorSeen, &rdev->flags) &&
test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
!test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
/*
* The device is suitable for reading (InSync),
* but has bad block(s) here. Let's try to correct them,
* if we are doing resync or repair. Otherwise, leave
* this device alone for this sync request.
*/
bio->bi_opf = REQ_OP_WRITE;
bio->bi_end_io = end_sync_write;
write_targets++;
}
}
if (rdev && bio->bi_end_io) {
atomic_inc(&rdev->nr_pending);
bio->bi_iter.bi_sector = sector_nr + rdev->data_offset;
bio_set_dev(bio, rdev->bdev);
if (test_bit(FailFast, &rdev->flags))
bio->bi_opf |= MD_FAILFAST;
}
}
rcu_read_unlock();
if (disk < 0)
disk = wonly;
r1_bio->read_disk = disk;
if (read_targets == 0 && min_bad > 0) {
/* These sectors are bad on all InSync devices, so we
* need to mark them bad on all write targets
*/
int ok = 1;
for (i = 0 ; i < conf->raid_disks * 2 ; i++)
if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
struct md_rdev *rdev = conf->mirrors[i].rdev;
ok = rdev_set_badblocks(rdev, sector_nr,
min_bad, 0
) && ok;
}
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
*skipped = 1;
put_buf(r1_bio);
if (!ok) {
/* Cannot record the badblocks, so need to
* abort the resync.
* If there are multiple read targets, could just
* fail the really bad ones ???
*/
conf->recovery_disabled = mddev->recovery_disabled;
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
return 0;
} else
return min_bad;
}
if (min_bad > 0 && min_bad < good_sectors) {
/* only resync enough to reach the next bad->good
* transition */
good_sectors = min_bad;
}
if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
/* extra read targets are also write targets */
write_targets += read_targets-1;
if (write_targets == 0 || read_targets == 0) {
/* There is nowhere to write, so all non-sync
* drives must be failed - so we are finished
*/
sector_t rv;
if (min_bad > 0)
max_sector = sector_nr + min_bad;
rv = max_sector - sector_nr;
*skipped = 1;
put_buf(r1_bio);
return rv;
}
if (max_sector > mddev->resync_max)
max_sector = mddev->resync_max; /* Don't do IO beyond here */
if (max_sector > sector_nr + good_sectors)
max_sector = sector_nr + good_sectors;
nr_sectors = 0;
sync_blocks = 0;
do {
struct page *page;
int len = PAGE_SIZE;
if (sector_nr + (len>>9) > max_sector)
len = (max_sector - sector_nr) << 9;
if (len == 0)
break;
if (sync_blocks == 0) {
if (!md_bitmap_start_sync(mddev->bitmap, sector_nr,
&sync_blocks, still_degraded) &&
!conf->fullsync &&
!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
break;
if ((len >> 9) > sync_blocks)
len = sync_blocks<<9;
}
for (i = 0 ; i < conf->raid_disks * 2; i++) {
struct resync_pages *rp;
bio = r1_bio->bios[i];
rp = get_resync_pages(bio);
if (bio->bi_end_io) {
page = resync_fetch_page(rp, page_idx);
/*
* won't fail because the vec table is big
* enough to hold all these pages
*/
__bio_add_page(bio, page, len, 0);
}
}
nr_sectors += len>>9;
sector_nr += len>>9;
sync_blocks -= (len>>9);
} while (++page_idx < RESYNC_PAGES);
r1_bio->sectors = nr_sectors;
if (mddev_is_clustered(mddev) &&
conf->cluster_sync_high < sector_nr + nr_sectors) {
conf->cluster_sync_low = mddev->curr_resync_completed;
conf->cluster_sync_high = conf->cluster_sync_low + CLUSTER_RESYNC_WINDOW_SECTORS;
/* Send resync message */
md_cluster_ops->resync_info_update(mddev,
conf->cluster_sync_low,
conf->cluster_sync_high);
}
/* For a user-requested sync, we read all readable devices and do a
* compare
*/
if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
atomic_set(&r1_bio->remaining, read_targets);
for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) {
bio = r1_bio->bios[i];
if (bio->bi_end_io == end_sync_read) {
read_targets--;
md_sync_acct_bio(bio, nr_sectors);
if (read_targets == 1)
bio->bi_opf &= ~MD_FAILFAST;
submit_bio_noacct(bio);
}
}
} else {
atomic_set(&r1_bio->remaining, 1);
bio = r1_bio->bios[r1_bio->read_disk];
md_sync_acct_bio(bio, nr_sectors);
if (read_targets == 1)
bio->bi_opf &= ~MD_FAILFAST;
submit_bio_noacct(bio);
}
return nr_sectors;
}
static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks)
{
if (sectors)
return sectors;
return mddev->dev_sectors;
}
static struct r1conf *setup_conf(struct mddev *mddev)
{
struct r1conf *conf;
int i;
struct raid1_info *disk;
struct md_rdev *rdev;
int err = -ENOMEM;
conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL);
if (!conf)
goto abort;
conf->nr_pending = kcalloc(BARRIER_BUCKETS_NR,
sizeof(atomic_t), GFP_KERNEL);
if (!conf->nr_pending)
goto abort;
conf->nr_waiting = kcalloc(BARRIER_BUCKETS_NR,
sizeof(atomic_t), GFP_KERNEL);
if (!conf->nr_waiting)
goto abort;
conf->nr_queued = kcalloc(BARRIER_BUCKETS_NR,
sizeof(atomic_t), GFP_KERNEL);
if (!conf->nr_queued)
goto abort;
conf->barrier = kcalloc(BARRIER_BUCKETS_NR,
sizeof(atomic_t), GFP_KERNEL);
if (!conf->barrier)
goto abort;
conf->mirrors = kzalloc(array3_size(sizeof(struct raid1_info),
mddev->raid_disks, 2),
GFP_KERNEL);
if (!conf->mirrors)
goto abort;
conf->tmppage = alloc_page(GFP_KERNEL);
if (!conf->tmppage)
goto abort;
conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
if (!conf->poolinfo)
goto abort;
conf->poolinfo->raid_disks = mddev->raid_disks * 2;
err = mempool_init(&conf->r1bio_pool, NR_RAID_BIOS, r1bio_pool_alloc,
rbio_pool_free, conf->poolinfo);
if (err)
goto abort;
err = bioset_init(&conf->bio_split, BIO_POOL_SIZE, 0, 0);
if (err)
goto abort;
conf->poolinfo->mddev = mddev;
err = -EINVAL;
spin_lock_init(&conf->device_lock);
rdev_for_each(rdev, mddev) {
int disk_idx = rdev->raid_disk;
if (disk_idx >= mddev->raid_disks
|| disk_idx < 0)
continue;
if (test_bit(Replacement, &rdev->flags))
disk = conf->mirrors + mddev->raid_disks + disk_idx;
else
disk = conf->mirrors + disk_idx;
if (disk->rdev)
goto abort;
disk->rdev = rdev;
disk->head_position = 0;
disk->seq_start = MaxSector;
}
conf->raid_disks = mddev->raid_disks;
conf->mddev = mddev;
INIT_LIST_HEAD(&conf->retry_list);
INIT_LIST_HEAD(&conf->bio_end_io_list);
spin_lock_init(&conf->resync_lock);
init_waitqueue_head(&conf->wait_barrier);
bio_list_init(&conf->pending_bio_list);
conf->recovery_disabled = mddev->recovery_disabled - 1;
err = -EIO;
for (i = 0; i < conf->raid_disks * 2; i++) {
disk = conf->mirrors + i;
if (i < conf->raid_disks &&
disk[conf->raid_disks].rdev) {
/* This slot has a replacement. */
if (!disk->rdev) {
/* No original, just make the replacement
* a recovering spare
*/
disk->rdev =
disk[conf->raid_disks].rdev;
disk[conf->raid_disks].rdev = NULL;
} else if (!test_bit(In_sync, &disk->rdev->flags))
/* Original is not in_sync - bad */
goto abort;
}
if (!disk->rdev ||
!test_bit(In_sync, &disk->rdev->flags)) {
disk->head_position = 0;
if (disk->rdev &&
(disk->rdev->saved_raid_disk < 0))
conf->fullsync = 1;
}
}
err = -ENOMEM;
rcu_assign_pointer(conf->thread,
md_register_thread(raid1d, mddev, "raid1"));
if (!conf->thread)
goto abort;
return conf;
abort:
if (conf) {
mempool_exit(&conf->r1bio_pool);
kfree(conf->mirrors);
safe_put_page(conf->tmppage);
kfree(conf->poolinfo);
kfree(conf->nr_pending);
kfree(conf->nr_waiting);
kfree(conf->nr_queued);
kfree(conf->barrier);
bioset_exit(&conf->bio_split);
kfree(conf);
}
return ERR_PTR(err);
}
static void raid1_free(struct mddev *mddev, void *priv);
static int raid1_run(struct mddev *mddev)
{
struct r1conf *conf;
int i;
struct md_rdev *rdev;
int ret;
if (mddev->level != 1) {
pr_warn("md/raid1:%s: raid level not set to mirroring (%d)\n",
mdname(mddev), mddev->level);
return -EIO;
}
if (mddev->reshape_position != MaxSector) {
pr_warn("md/raid1:%s: reshape_position set but not supported\n",
mdname(mddev));
return -EIO;
}
if (mddev_init_writes_pending(mddev) < 0)
return -ENOMEM;
/*
* copy the already verified devices into our private RAID1
* bookkeeping area. [whatever we allocate in run(),
* should be freed in raid1_free()]
*/
if (mddev->private == NULL)
conf = setup_conf(mddev);
else
conf = mddev->private;
if (IS_ERR(conf))
return PTR_ERR(conf);
if (mddev->queue)
blk_queue_max_write_zeroes_sectors(mddev->queue, 0);
rdev_for_each(rdev, mddev) {
if (!mddev->gendisk)
continue;
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
}
mddev->degraded = 0;
for (i = 0; i < conf->raid_disks; i++)
if (conf->mirrors[i].rdev == NULL ||
!test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
test_bit(Faulty, &conf->mirrors[i].rdev->flags))
mddev->degraded++;
/*
* RAID1 needs at least one disk in active
*/
if (conf->raid_disks - mddev->degraded < 1) {
md_unregister_thread(mddev, &conf->thread);
ret = -EINVAL;
goto abort;
}
if (conf->raid_disks - mddev->degraded == 1)
mddev->recovery_cp = MaxSector;
if (mddev->recovery_cp != MaxSector)
pr_info("md/raid1:%s: not clean -- starting background reconstruction\n",
mdname(mddev));
pr_info("md/raid1:%s: active with %d out of %d mirrors\n",
mdname(mddev), mddev->raid_disks - mddev->degraded,
mddev->raid_disks);
/*
* Ok, everything is just fine now
*/
rcu_assign_pointer(mddev->thread, conf->thread);
rcu_assign_pointer(conf->thread, NULL);
mddev->private = conf;
set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
ret = md_integrity_register(mddev);
if (ret) {
md_unregister_thread(mddev, &mddev->thread);
goto abort;
}
return 0;
abort:
raid1_free(mddev, conf);
return ret;
}
static void raid1_free(struct mddev *mddev, void *priv)
{
struct r1conf *conf = priv;
mempool_exit(&conf->r1bio_pool);
kfree(conf->mirrors);
safe_put_page(conf->tmppage);
kfree(conf->poolinfo);
kfree(conf->nr_pending);
kfree(conf->nr_waiting);
kfree(conf->nr_queued);
kfree(conf->barrier);
bioset_exit(&conf->bio_split);
kfree(conf);
}
static int raid1_resize(struct mddev *mddev, sector_t sectors)
{
/* no resync is happening, and there is enough space
* on all devices, so we can resize.
* We need to make sure resync covers any new space.
* If the array is shrinking we should possibly wait until
* any io in the removed space completes, but it hardly seems
* worth it.
*/
sector_t newsize = raid1_size(mddev, sectors, 0);
if (mddev->external_size &&
mddev->array_sectors > newsize)
return -EINVAL;
if (mddev->bitmap) {
int ret = md_bitmap_resize(mddev->bitmap, newsize, 0, 0);
if (ret)
return ret;
}
md_set_array_sectors(mddev, newsize);
if (sectors > mddev->dev_sectors &&
mddev->recovery_cp > mddev->dev_sectors) {
mddev->recovery_cp = mddev->dev_sectors;
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
}
mddev->dev_sectors = sectors;
mddev->resync_max_sectors = sectors;
return 0;
}
static int raid1_reshape(struct mddev *mddev)
{
/* We need to:
* 1/ resize the r1bio_pool
* 2/ resize conf->mirrors
*
* We allocate a new r1bio_pool if we can.
* Then raise a device barrier and wait until all IO stops.
* Then resize conf->mirrors and swap in the new r1bio pool.
*
* At the same time, we "pack" the devices so that all the missing
* devices have the higher raid_disk numbers.
*/
mempool_t newpool, oldpool;
struct pool_info *newpoolinfo;
struct raid1_info *newmirrors;
struct r1conf *conf = mddev->private;
int cnt, raid_disks;
unsigned long flags;
int d, d2;
int ret;
memset(&newpool, 0, sizeof(newpool));
memset(&oldpool, 0, sizeof(oldpool));
/* Cannot change chunk_size, layout, or level */
if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
mddev->layout != mddev->new_layout ||
mddev->level != mddev->new_level) {
mddev->new_chunk_sectors = mddev->chunk_sectors;
mddev->new_layout = mddev->layout;
mddev->new_level = mddev->level;
return -EINVAL;
}
if (!mddev_is_clustered(mddev))
md_allow_write(mddev);
raid_disks = mddev->raid_disks + mddev->delta_disks;
if (raid_disks < conf->raid_disks) {
cnt=0;
for (d= 0; d < conf->raid_disks; d++)
if (conf->mirrors[d].rdev)
cnt++;
if (cnt > raid_disks)
return -EBUSY;
}
newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
if (!newpoolinfo)
return -ENOMEM;
newpoolinfo->mddev = mddev;
newpoolinfo->raid_disks = raid_disks * 2;
ret = mempool_init(&newpool, NR_RAID_BIOS, r1bio_pool_alloc,
rbio_pool_free, newpoolinfo);
if (ret) {
kfree(newpoolinfo);
return ret;
}
newmirrors = kzalloc(array3_size(sizeof(struct raid1_info),
raid_disks, 2),
GFP_KERNEL);
if (!newmirrors) {
kfree(newpoolinfo);
mempool_exit(&newpool);
return -ENOMEM;
}
freeze_array(conf, 0);
/* ok, everything is stopped */
oldpool = conf->r1bio_pool;
conf->r1bio_pool = newpool;
for (d = d2 = 0; d < conf->raid_disks; d++) {
struct md_rdev *rdev = conf->mirrors[d].rdev;
if (rdev && rdev->raid_disk != d2) {
sysfs_unlink_rdev(mddev, rdev);
rdev->raid_disk = d2;
sysfs_unlink_rdev(mddev, rdev);
if (sysfs_link_rdev(mddev, rdev))
pr_warn("md/raid1:%s: cannot register rd%d\n",
mdname(mddev), rdev->raid_disk);
}
if (rdev)
newmirrors[d2++].rdev = rdev;
}
kfree(conf->mirrors);
conf->mirrors = newmirrors;
kfree(conf->poolinfo);
conf->poolinfo = newpoolinfo;
spin_lock_irqsave(&conf->device_lock, flags);
mddev->degraded += (raid_disks - conf->raid_disks);
spin_unlock_irqrestore(&conf->device_lock, flags);
conf->raid_disks = mddev->raid_disks = raid_disks;
mddev->delta_disks = 0;
unfreeze_array(conf);
set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
mempool_exit(&oldpool);
return 0;
}
static void raid1_quiesce(struct mddev *mddev, int quiesce)
{
struct r1conf *conf = mddev->private;
if (quiesce)
freeze_array(conf, 0);
else
unfreeze_array(conf);
}
static void *raid1_takeover(struct mddev *mddev)
{
/* raid1 can take over:
* raid5 with 2 devices, any layout or chunk size
*/
if (mddev->level == 5 && mddev->raid_disks == 2) {
struct r1conf *conf;
mddev->new_level = 1;
mddev->new_layout = 0;
mddev->new_chunk_sectors = 0;
conf = setup_conf(mddev);
if (!IS_ERR(conf)) {
/* Array must appear to be quiesced */
conf->array_frozen = 1;
mddev_clear_unsupported_flags(mddev,
UNSUPPORTED_MDDEV_FLAGS);
}
return conf;
}
return ERR_PTR(-EINVAL);
}
static struct md_personality raid1_personality =
{
.name = "raid1",
.level = 1,
.owner = THIS_MODULE,
.make_request = raid1_make_request,
.run = raid1_run,
.free = raid1_free,
.status = raid1_status,
.error_handler = raid1_error,
.hot_add_disk = raid1_add_disk,
.hot_remove_disk= raid1_remove_disk,
.spare_active = raid1_spare_active,
.sync_request = raid1_sync_request,
.resize = raid1_resize,
.size = raid1_size,
.check_reshape = raid1_reshape,
.quiesce = raid1_quiesce,
.takeover = raid1_takeover,
};
static int __init raid_init(void)
{
return register_md_personality(&raid1_personality);
}
static void raid_exit(void)
{
unregister_md_personality(&raid1_personality);
}
module_init(raid_init);
module_exit(raid_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD");
MODULE_ALIAS("md-personality-3"); /* RAID1 */
MODULE_ALIAS("md-raid1");
MODULE_ALIAS("md-level-1");
| linux-master | drivers/md/raid1.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2003 Sistina Software
* Copyright (C) 2006 Red Hat GmbH
*
* This file is released under the GPL.
*/
#include "dm-core.h"
#include <linux/device-mapper.h>
#include <linux/bio.h>
#include <linux/completion.h>
#include <linux/mempool.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/dm-io.h>
#define DM_MSG_PREFIX "io"
#define DM_IO_MAX_REGIONS BITS_PER_LONG
struct dm_io_client {
mempool_t pool;
struct bio_set bios;
};
/*
* Aligning 'struct io' reduces the number of bits required to store
* its address. Refer to store_io_and_region_in_bio() below.
*/
struct io {
unsigned long error_bits;
atomic_t count;
struct dm_io_client *client;
io_notify_fn callback;
void *context;
void *vma_invalidate_address;
unsigned long vma_invalidate_size;
} __aligned(DM_IO_MAX_REGIONS);
static struct kmem_cache *_dm_io_cache;
/*
* Create a client with mempool and bioset.
*/
struct dm_io_client *dm_io_client_create(void)
{
struct dm_io_client *client;
unsigned int min_ios = dm_get_reserved_bio_based_ios();
int ret;
client = kzalloc(sizeof(*client), GFP_KERNEL);
if (!client)
return ERR_PTR(-ENOMEM);
ret = mempool_init_slab_pool(&client->pool, min_ios, _dm_io_cache);
if (ret)
goto bad;
ret = bioset_init(&client->bios, min_ios, 0, BIOSET_NEED_BVECS);
if (ret)
goto bad;
return client;
bad:
mempool_exit(&client->pool);
kfree(client);
return ERR_PTR(ret);
}
EXPORT_SYMBOL(dm_io_client_create);
void dm_io_client_destroy(struct dm_io_client *client)
{
mempool_exit(&client->pool);
bioset_exit(&client->bios);
kfree(client);
}
EXPORT_SYMBOL(dm_io_client_destroy);
/*
*-------------------------------------------------------------------
* We need to keep track of which region a bio is doing io for.
* To avoid a memory allocation to store just 5 or 6 bits, we
* ensure the 'struct io' pointer is aligned so enough low bits are
* always zero and then combine it with the region number directly in
* bi_private.
*-------------------------------------------------------------------
*/
static void store_io_and_region_in_bio(struct bio *bio, struct io *io,
unsigned int region)
{
if (unlikely(!IS_ALIGNED((unsigned long)io, DM_IO_MAX_REGIONS))) {
DMCRIT("Unaligned struct io pointer %p", io);
BUG();
}
bio->bi_private = (void *)((unsigned long)io | region);
}
static void retrieve_io_and_region_from_bio(struct bio *bio, struct io **io,
unsigned int *region)
{
unsigned long val = (unsigned long)bio->bi_private;
*io = (void *)(val & -(unsigned long)DM_IO_MAX_REGIONS);
*region = val & (DM_IO_MAX_REGIONS - 1);
}
/*
*--------------------------------------------------------------
* We need an io object to keep track of the number of bios that
* have been dispatched for a particular io.
*--------------------------------------------------------------
*/
static void complete_io(struct io *io)
{
unsigned long error_bits = io->error_bits;
io_notify_fn fn = io->callback;
void *context = io->context;
if (io->vma_invalidate_size)
invalidate_kernel_vmap_range(io->vma_invalidate_address,
io->vma_invalidate_size);
mempool_free(io, &io->client->pool);
fn(error_bits, context);
}
static void dec_count(struct io *io, unsigned int region, blk_status_t error)
{
if (error)
set_bit(region, &io->error_bits);
if (atomic_dec_and_test(&io->count))
complete_io(io);
}
static void endio(struct bio *bio)
{
struct io *io;
unsigned int region;
blk_status_t error;
if (bio->bi_status && bio_data_dir(bio) == READ)
zero_fill_bio(bio);
/*
* The bio destructor in bio_put() may use the io object.
*/
retrieve_io_and_region_from_bio(bio, &io, ®ion);
error = bio->bi_status;
bio_put(bio);
dec_count(io, region, error);
}
/*
*--------------------------------------------------------------
* These little objects provide an abstraction for getting a new
* destination page for io.
*--------------------------------------------------------------
*/
struct dpages {
void (*get_page)(struct dpages *dp,
struct page **p, unsigned long *len, unsigned int *offset);
void (*next_page)(struct dpages *dp);
union {
unsigned int context_u;
struct bvec_iter context_bi;
};
void *context_ptr;
void *vma_invalidate_address;
unsigned long vma_invalidate_size;
};
/*
* Functions for getting the pages from a list.
*/
static void list_get_page(struct dpages *dp,
struct page **p, unsigned long *len, unsigned int *offset)
{
unsigned int o = dp->context_u;
struct page_list *pl = dp->context_ptr;
*p = pl->page;
*len = PAGE_SIZE - o;
*offset = o;
}
static void list_next_page(struct dpages *dp)
{
struct page_list *pl = dp->context_ptr;
dp->context_ptr = pl->next;
dp->context_u = 0;
}
static void list_dp_init(struct dpages *dp, struct page_list *pl, unsigned int offset)
{
dp->get_page = list_get_page;
dp->next_page = list_next_page;
dp->context_u = offset;
dp->context_ptr = pl;
}
/*
* Functions for getting the pages from a bvec.
*/
static void bio_get_page(struct dpages *dp, struct page **p,
unsigned long *len, unsigned int *offset)
{
struct bio_vec bvec = bvec_iter_bvec((struct bio_vec *)dp->context_ptr,
dp->context_bi);
*p = bvec.bv_page;
*len = bvec.bv_len;
*offset = bvec.bv_offset;
/* avoid figuring it out again in bio_next_page() */
dp->context_bi.bi_sector = (sector_t)bvec.bv_len;
}
static void bio_next_page(struct dpages *dp)
{
unsigned int len = (unsigned int)dp->context_bi.bi_sector;
bvec_iter_advance((struct bio_vec *)dp->context_ptr,
&dp->context_bi, len);
}
static void bio_dp_init(struct dpages *dp, struct bio *bio)
{
dp->get_page = bio_get_page;
dp->next_page = bio_next_page;
/*
* We just use bvec iterator to retrieve pages, so it is ok to
* access the bvec table directly here
*/
dp->context_ptr = bio->bi_io_vec;
dp->context_bi = bio->bi_iter;
}
/*
* Functions for getting the pages from a VMA.
*/
static void vm_get_page(struct dpages *dp,
struct page **p, unsigned long *len, unsigned int *offset)
{
*p = vmalloc_to_page(dp->context_ptr);
*offset = dp->context_u;
*len = PAGE_SIZE - dp->context_u;
}
static void vm_next_page(struct dpages *dp)
{
dp->context_ptr += PAGE_SIZE - dp->context_u;
dp->context_u = 0;
}
static void vm_dp_init(struct dpages *dp, void *data)
{
dp->get_page = vm_get_page;
dp->next_page = vm_next_page;
dp->context_u = offset_in_page(data);
dp->context_ptr = data;
}
/*
* Functions for getting the pages from kernel memory.
*/
static void km_get_page(struct dpages *dp, struct page **p, unsigned long *len,
unsigned int *offset)
{
*p = virt_to_page(dp->context_ptr);
*offset = dp->context_u;
*len = PAGE_SIZE - dp->context_u;
}
static void km_next_page(struct dpages *dp)
{
dp->context_ptr += PAGE_SIZE - dp->context_u;
dp->context_u = 0;
}
static void km_dp_init(struct dpages *dp, void *data)
{
dp->get_page = km_get_page;
dp->next_page = km_next_page;
dp->context_u = offset_in_page(data);
dp->context_ptr = data;
}
/*
*---------------------------------------------------------------
* IO routines that accept a list of pages.
*---------------------------------------------------------------
*/
static void do_region(const blk_opf_t opf, unsigned int region,
struct dm_io_region *where, struct dpages *dp,
struct io *io)
{
struct bio *bio;
struct page *page;
unsigned long len;
unsigned int offset;
unsigned int num_bvecs;
sector_t remaining = where->count;
struct request_queue *q = bdev_get_queue(where->bdev);
sector_t num_sectors;
unsigned int special_cmd_max_sectors;
const enum req_op op = opf & REQ_OP_MASK;
/*
* Reject unsupported discard and write same requests.
*/
if (op == REQ_OP_DISCARD)
special_cmd_max_sectors = bdev_max_discard_sectors(where->bdev);
else if (op == REQ_OP_WRITE_ZEROES)
special_cmd_max_sectors = q->limits.max_write_zeroes_sectors;
if ((op == REQ_OP_DISCARD || op == REQ_OP_WRITE_ZEROES) &&
special_cmd_max_sectors == 0) {
atomic_inc(&io->count);
dec_count(io, region, BLK_STS_NOTSUPP);
return;
}
/*
* where->count may be zero if op holds a flush and we need to
* send a zero-sized flush.
*/
do {
/*
* Allocate a suitably sized-bio.
*/
switch (op) {
case REQ_OP_DISCARD:
case REQ_OP_WRITE_ZEROES:
num_bvecs = 0;
break;
default:
num_bvecs = bio_max_segs(dm_sector_div_up(remaining,
(PAGE_SIZE >> SECTOR_SHIFT)));
}
bio = bio_alloc_bioset(where->bdev, num_bvecs, opf, GFP_NOIO,
&io->client->bios);
bio->bi_iter.bi_sector = where->sector + (where->count - remaining);
bio->bi_end_io = endio;
store_io_and_region_in_bio(bio, io, region);
if (op == REQ_OP_DISCARD || op == REQ_OP_WRITE_ZEROES) {
num_sectors = min_t(sector_t, special_cmd_max_sectors, remaining);
bio->bi_iter.bi_size = num_sectors << SECTOR_SHIFT;
remaining -= num_sectors;
} else {
while (remaining) {
/*
* Try and add as many pages as possible.
*/
dp->get_page(dp, &page, &len, &offset);
len = min(len, to_bytes(remaining));
if (!bio_add_page(bio, page, len, offset))
break;
offset = 0;
remaining -= to_sector(len);
dp->next_page(dp);
}
}
atomic_inc(&io->count);
submit_bio(bio);
} while (remaining);
}
static void dispatch_io(blk_opf_t opf, unsigned int num_regions,
struct dm_io_region *where, struct dpages *dp,
struct io *io, int sync)
{
int i;
struct dpages old_pages = *dp;
BUG_ON(num_regions > DM_IO_MAX_REGIONS);
if (sync)
opf |= REQ_SYNC;
/*
* For multiple regions we need to be careful to rewind
* the dp object for each call to do_region.
*/
for (i = 0; i < num_regions; i++) {
*dp = old_pages;
if (where[i].count || (opf & REQ_PREFLUSH))
do_region(opf, i, where + i, dp, io);
}
/*
* Drop the extra reference that we were holding to avoid
* the io being completed too early.
*/
dec_count(io, 0, 0);
}
struct sync_io {
unsigned long error_bits;
struct completion wait;
};
static void sync_io_complete(unsigned long error, void *context)
{
struct sync_io *sio = context;
sio->error_bits = error;
complete(&sio->wait);
}
static int sync_io(struct dm_io_client *client, unsigned int num_regions,
struct dm_io_region *where, blk_opf_t opf, struct dpages *dp,
unsigned long *error_bits)
{
struct io *io;
struct sync_io sio;
if (num_regions > 1 && !op_is_write(opf)) {
WARN_ON(1);
return -EIO;
}
init_completion(&sio.wait);
io = mempool_alloc(&client->pool, GFP_NOIO);
io->error_bits = 0;
atomic_set(&io->count, 1); /* see dispatch_io() */
io->client = client;
io->callback = sync_io_complete;
io->context = &sio;
io->vma_invalidate_address = dp->vma_invalidate_address;
io->vma_invalidate_size = dp->vma_invalidate_size;
dispatch_io(opf, num_regions, where, dp, io, 1);
wait_for_completion_io(&sio.wait);
if (error_bits)
*error_bits = sio.error_bits;
return sio.error_bits ? -EIO : 0;
}
static int async_io(struct dm_io_client *client, unsigned int num_regions,
struct dm_io_region *where, blk_opf_t opf,
struct dpages *dp, io_notify_fn fn, void *context)
{
struct io *io;
if (num_regions > 1 && !op_is_write(opf)) {
WARN_ON(1);
fn(1, context);
return -EIO;
}
io = mempool_alloc(&client->pool, GFP_NOIO);
io->error_bits = 0;
atomic_set(&io->count, 1); /* see dispatch_io() */
io->client = client;
io->callback = fn;
io->context = context;
io->vma_invalidate_address = dp->vma_invalidate_address;
io->vma_invalidate_size = dp->vma_invalidate_size;
dispatch_io(opf, num_regions, where, dp, io, 0);
return 0;
}
static int dp_init(struct dm_io_request *io_req, struct dpages *dp,
unsigned long size)
{
/* Set up dpages based on memory type */
dp->vma_invalidate_address = NULL;
dp->vma_invalidate_size = 0;
switch (io_req->mem.type) {
case DM_IO_PAGE_LIST:
list_dp_init(dp, io_req->mem.ptr.pl, io_req->mem.offset);
break;
case DM_IO_BIO:
bio_dp_init(dp, io_req->mem.ptr.bio);
break;
case DM_IO_VMA:
flush_kernel_vmap_range(io_req->mem.ptr.vma, size);
if ((io_req->bi_opf & REQ_OP_MASK) == REQ_OP_READ) {
dp->vma_invalidate_address = io_req->mem.ptr.vma;
dp->vma_invalidate_size = size;
}
vm_dp_init(dp, io_req->mem.ptr.vma);
break;
case DM_IO_KMEM:
km_dp_init(dp, io_req->mem.ptr.addr);
break;
default:
return -EINVAL;
}
return 0;
}
int dm_io(struct dm_io_request *io_req, unsigned int num_regions,
struct dm_io_region *where, unsigned long *sync_error_bits)
{
int r;
struct dpages dp;
r = dp_init(io_req, &dp, (unsigned long)where->count << SECTOR_SHIFT);
if (r)
return r;
if (!io_req->notify.fn)
return sync_io(io_req->client, num_regions, where,
io_req->bi_opf, &dp, sync_error_bits);
return async_io(io_req->client, num_regions, where,
io_req->bi_opf, &dp, io_req->notify.fn,
io_req->notify.context);
}
EXPORT_SYMBOL(dm_io);
int __init dm_io_init(void)
{
_dm_io_cache = KMEM_CACHE(io, 0);
if (!_dm_io_cache)
return -ENOMEM;
return 0;
}
void dm_io_exit(void)
{
kmem_cache_destroy(_dm_io_cache);
_dm_io_cache = NULL;
}
| linux-master | drivers/md/dm-io.c |
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* raid5.c : Multiple Devices driver for Linux
* Copyright (C) 1996, 1997 Ingo Molnar, Miguel de Icaza, Gadi Oxman
* Copyright (C) 1999, 2000 Ingo Molnar
* Copyright (C) 2002, 2003 H. Peter Anvin
*
* RAID-4/5/6 management functions.
* Thanks to Penguin Computing for making the RAID-6 development possible
* by donating a test server!
*/
/*
* BITMAP UNPLUGGING:
*
* The sequencing for updating the bitmap reliably is a little
* subtle (and I got it wrong the first time) so it deserves some
* explanation.
*
* We group bitmap updates into batches. Each batch has a number.
* We may write out several batches at once, but that isn't very important.
* conf->seq_write is the number of the last batch successfully written.
* conf->seq_flush is the number of the last batch that was closed to
* new additions.
* When we discover that we will need to write to any block in a stripe
* (in add_stripe_bio) we update the in-memory bitmap and record in sh->bm_seq
* the number of the batch it will be in. This is seq_flush+1.
* When we are ready to do a write, if that batch hasn't been written yet,
* we plug the array and queue the stripe for later.
* When an unplug happens, we increment bm_flush, thus closing the current
* batch.
* When we notice that bm_flush > bm_write, we write out all pending updates
* to the bitmap, and advance bm_write to where bm_flush was.
* This may occasionally write a bit out twice, but is sure never to
* miss any bits.
*/
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/raid/pq.h>
#include <linux/async_tx.h>
#include <linux/module.h>
#include <linux/async.h>
#include <linux/seq_file.h>
#include <linux/cpu.h>
#include <linux/slab.h>
#include <linux/ratelimit.h>
#include <linux/nodemask.h>
#include <trace/events/block.h>
#include <linux/list_sort.h>
#include "md.h"
#include "raid5.h"
#include "raid0.h"
#include "md-bitmap.h"
#include "raid5-log.h"
#define UNSUPPORTED_MDDEV_FLAGS (1L << MD_FAILFAST_SUPPORTED)
#define cpu_to_group(cpu) cpu_to_node(cpu)
#define ANY_GROUP NUMA_NO_NODE
#define RAID5_MAX_REQ_STRIPES 256
static bool devices_handle_discard_safely = false;
module_param(devices_handle_discard_safely, bool, 0644);
MODULE_PARM_DESC(devices_handle_discard_safely,
"Set to Y if all devices in each array reliably return zeroes on reads from discarded regions");
static struct workqueue_struct *raid5_wq;
static inline struct hlist_head *stripe_hash(struct r5conf *conf, sector_t sect)
{
int hash = (sect >> RAID5_STRIPE_SHIFT(conf)) & HASH_MASK;
return &conf->stripe_hashtbl[hash];
}
static inline int stripe_hash_locks_hash(struct r5conf *conf, sector_t sect)
{
return (sect >> RAID5_STRIPE_SHIFT(conf)) & STRIPE_HASH_LOCKS_MASK;
}
static inline void lock_device_hash_lock(struct r5conf *conf, int hash)
__acquires(&conf->device_lock)
{
spin_lock_irq(conf->hash_locks + hash);
spin_lock(&conf->device_lock);
}
static inline void unlock_device_hash_lock(struct r5conf *conf, int hash)
__releases(&conf->device_lock)
{
spin_unlock(&conf->device_lock);
spin_unlock_irq(conf->hash_locks + hash);
}
static inline void lock_all_device_hash_locks_irq(struct r5conf *conf)
__acquires(&conf->device_lock)
{
int i;
spin_lock_irq(conf->hash_locks);
for (i = 1; i < NR_STRIPE_HASH_LOCKS; i++)
spin_lock_nest_lock(conf->hash_locks + i, conf->hash_locks);
spin_lock(&conf->device_lock);
}
static inline void unlock_all_device_hash_locks_irq(struct r5conf *conf)
__releases(&conf->device_lock)
{
int i;
spin_unlock(&conf->device_lock);
for (i = NR_STRIPE_HASH_LOCKS - 1; i; i--)
spin_unlock(conf->hash_locks + i);
spin_unlock_irq(conf->hash_locks);
}
/* Find first data disk in a raid6 stripe */
static inline int raid6_d0(struct stripe_head *sh)
{
if (sh->ddf_layout)
/* ddf always start from first device */
return 0;
/* md starts just after Q block */
if (sh->qd_idx == sh->disks - 1)
return 0;
else
return sh->qd_idx + 1;
}
static inline int raid6_next_disk(int disk, int raid_disks)
{
disk++;
return (disk < raid_disks) ? disk : 0;
}
/* When walking through the disks in a raid5, starting at raid6_d0,
* We need to map each disk to a 'slot', where the data disks are slot
* 0 .. raid_disks-3, the parity disk is raid_disks-2 and the Q disk
* is raid_disks-1. This help does that mapping.
*/
static int raid6_idx_to_slot(int idx, struct stripe_head *sh,
int *count, int syndrome_disks)
{
int slot = *count;
if (sh->ddf_layout)
(*count)++;
if (idx == sh->pd_idx)
return syndrome_disks;
if (idx == sh->qd_idx)
return syndrome_disks + 1;
if (!sh->ddf_layout)
(*count)++;
return slot;
}
static void print_raid5_conf (struct r5conf *conf);
static int stripe_operations_active(struct stripe_head *sh)
{
return sh->check_state || sh->reconstruct_state ||
test_bit(STRIPE_BIOFILL_RUN, &sh->state) ||
test_bit(STRIPE_COMPUTE_RUN, &sh->state);
}
static bool stripe_is_lowprio(struct stripe_head *sh)
{
return (test_bit(STRIPE_R5C_FULL_STRIPE, &sh->state) ||
test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state)) &&
!test_bit(STRIPE_R5C_CACHING, &sh->state);
}
static void raid5_wakeup_stripe_thread(struct stripe_head *sh)
__must_hold(&sh->raid_conf->device_lock)
{
struct r5conf *conf = sh->raid_conf;
struct r5worker_group *group;
int thread_cnt;
int i, cpu = sh->cpu;
if (!cpu_online(cpu)) {
cpu = cpumask_any(cpu_online_mask);
sh->cpu = cpu;
}
if (list_empty(&sh->lru)) {
struct r5worker_group *group;
group = conf->worker_groups + cpu_to_group(cpu);
if (stripe_is_lowprio(sh))
list_add_tail(&sh->lru, &group->loprio_list);
else
list_add_tail(&sh->lru, &group->handle_list);
group->stripes_cnt++;
sh->group = group;
}
if (conf->worker_cnt_per_group == 0) {
md_wakeup_thread(conf->mddev->thread);
return;
}
group = conf->worker_groups + cpu_to_group(sh->cpu);
group->workers[0].working = true;
/* at least one worker should run to avoid race */
queue_work_on(sh->cpu, raid5_wq, &group->workers[0].work);
thread_cnt = group->stripes_cnt / MAX_STRIPE_BATCH - 1;
/* wakeup more workers */
for (i = 1; i < conf->worker_cnt_per_group && thread_cnt > 0; i++) {
if (group->workers[i].working == false) {
group->workers[i].working = true;
queue_work_on(sh->cpu, raid5_wq,
&group->workers[i].work);
thread_cnt--;
}
}
}
static void do_release_stripe(struct r5conf *conf, struct stripe_head *sh,
struct list_head *temp_inactive_list)
__must_hold(&conf->device_lock)
{
int i;
int injournal = 0; /* number of date pages with R5_InJournal */
BUG_ON(!list_empty(&sh->lru));
BUG_ON(atomic_read(&conf->active_stripes)==0);
if (r5c_is_writeback(conf->log))
for (i = sh->disks; i--; )
if (test_bit(R5_InJournal, &sh->dev[i].flags))
injournal++;
/*
* In the following cases, the stripe cannot be released to cached
* lists. Therefore, we make the stripe write out and set
* STRIPE_HANDLE:
* 1. when quiesce in r5c write back;
* 2. when resync is requested fot the stripe.
*/
if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state) ||
(conf->quiesce && r5c_is_writeback(conf->log) &&
!test_bit(STRIPE_HANDLE, &sh->state) && injournal != 0)) {
if (test_bit(STRIPE_R5C_CACHING, &sh->state))
r5c_make_stripe_write_out(sh);
set_bit(STRIPE_HANDLE, &sh->state);
}
if (test_bit(STRIPE_HANDLE, &sh->state)) {
if (test_bit(STRIPE_DELAYED, &sh->state) &&
!test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
list_add_tail(&sh->lru, &conf->delayed_list);
else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
sh->bm_seq - conf->seq_write > 0)
list_add_tail(&sh->lru, &conf->bitmap_list);
else {
clear_bit(STRIPE_DELAYED, &sh->state);
clear_bit(STRIPE_BIT_DELAY, &sh->state);
if (conf->worker_cnt_per_group == 0) {
if (stripe_is_lowprio(sh))
list_add_tail(&sh->lru,
&conf->loprio_list);
else
list_add_tail(&sh->lru,
&conf->handle_list);
} else {
raid5_wakeup_stripe_thread(sh);
return;
}
}
md_wakeup_thread(conf->mddev->thread);
} else {
BUG_ON(stripe_operations_active(sh));
if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
if (atomic_dec_return(&conf->preread_active_stripes)
< IO_THRESHOLD)
md_wakeup_thread(conf->mddev->thread);
atomic_dec(&conf->active_stripes);
if (!test_bit(STRIPE_EXPANDING, &sh->state)) {
if (!r5c_is_writeback(conf->log))
list_add_tail(&sh->lru, temp_inactive_list);
else {
WARN_ON(test_bit(R5_InJournal, &sh->dev[sh->pd_idx].flags));
if (injournal == 0)
list_add_tail(&sh->lru, temp_inactive_list);
else if (injournal == conf->raid_disks - conf->max_degraded) {
/* full stripe */
if (!test_and_set_bit(STRIPE_R5C_FULL_STRIPE, &sh->state))
atomic_inc(&conf->r5c_cached_full_stripes);
if (test_and_clear_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state))
atomic_dec(&conf->r5c_cached_partial_stripes);
list_add_tail(&sh->lru, &conf->r5c_full_stripe_list);
r5c_check_cached_full_stripe(conf);
} else
/*
* STRIPE_R5C_PARTIAL_STRIPE is set in
* r5c_try_caching_write(). No need to
* set it again.
*/
list_add_tail(&sh->lru, &conf->r5c_partial_stripe_list);
}
}
}
}
static void __release_stripe(struct r5conf *conf, struct stripe_head *sh,
struct list_head *temp_inactive_list)
__must_hold(&conf->device_lock)
{
if (atomic_dec_and_test(&sh->count))
do_release_stripe(conf, sh, temp_inactive_list);
}
/*
* @hash could be NR_STRIPE_HASH_LOCKS, then we have a list of inactive_list
*
* Be careful: Only one task can add/delete stripes from temp_inactive_list at
* given time. Adding stripes only takes device lock, while deleting stripes
* only takes hash lock.
*/
static void release_inactive_stripe_list(struct r5conf *conf,
struct list_head *temp_inactive_list,
int hash)
{
int size;
bool do_wakeup = false;
unsigned long flags;
if (hash == NR_STRIPE_HASH_LOCKS) {
size = NR_STRIPE_HASH_LOCKS;
hash = NR_STRIPE_HASH_LOCKS - 1;
} else
size = 1;
while (size) {
struct list_head *list = &temp_inactive_list[size - 1];
/*
* We don't hold any lock here yet, raid5_get_active_stripe() might
* remove stripes from the list
*/
if (!list_empty_careful(list)) {
spin_lock_irqsave(conf->hash_locks + hash, flags);
if (list_empty(conf->inactive_list + hash) &&
!list_empty(list))
atomic_dec(&conf->empty_inactive_list_nr);
list_splice_tail_init(list, conf->inactive_list + hash);
do_wakeup = true;
spin_unlock_irqrestore(conf->hash_locks + hash, flags);
}
size--;
hash--;
}
if (do_wakeup) {
wake_up(&conf->wait_for_stripe);
if (atomic_read(&conf->active_stripes) == 0)
wake_up(&conf->wait_for_quiescent);
if (conf->retry_read_aligned)
md_wakeup_thread(conf->mddev->thread);
}
}
static int release_stripe_list(struct r5conf *conf,
struct list_head *temp_inactive_list)
__must_hold(&conf->device_lock)
{
struct stripe_head *sh, *t;
int count = 0;
struct llist_node *head;
head = llist_del_all(&conf->released_stripes);
head = llist_reverse_order(head);
llist_for_each_entry_safe(sh, t, head, release_list) {
int hash;
/* sh could be readded after STRIPE_ON_RELEASE_LIST is cleard */
smp_mb();
clear_bit(STRIPE_ON_RELEASE_LIST, &sh->state);
/*
* Don't worry the bit is set here, because if the bit is set
* again, the count is always > 1. This is true for
* STRIPE_ON_UNPLUG_LIST bit too.
*/
hash = sh->hash_lock_index;
__release_stripe(conf, sh, &temp_inactive_list[hash]);
count++;
}
return count;
}
void raid5_release_stripe(struct stripe_head *sh)
{
struct r5conf *conf = sh->raid_conf;
unsigned long flags;
struct list_head list;
int hash;
bool wakeup;
/* Avoid release_list until the last reference.
*/
if (atomic_add_unless(&sh->count, -1, 1))
return;
if (unlikely(!conf->mddev->thread) ||
test_and_set_bit(STRIPE_ON_RELEASE_LIST, &sh->state))
goto slow_path;
wakeup = llist_add(&sh->release_list, &conf->released_stripes);
if (wakeup)
md_wakeup_thread(conf->mddev->thread);
return;
slow_path:
/* we are ok here if STRIPE_ON_RELEASE_LIST is set or not */
if (atomic_dec_and_lock_irqsave(&sh->count, &conf->device_lock, flags)) {
INIT_LIST_HEAD(&list);
hash = sh->hash_lock_index;
do_release_stripe(conf, sh, &list);
spin_unlock_irqrestore(&conf->device_lock, flags);
release_inactive_stripe_list(conf, &list, hash);
}
}
static inline void remove_hash(struct stripe_head *sh)
{
pr_debug("remove_hash(), stripe %llu\n",
(unsigned long long)sh->sector);
hlist_del_init(&sh->hash);
}
static inline void insert_hash(struct r5conf *conf, struct stripe_head *sh)
{
struct hlist_head *hp = stripe_hash(conf, sh->sector);
pr_debug("insert_hash(), stripe %llu\n",
(unsigned long long)sh->sector);
hlist_add_head(&sh->hash, hp);
}
/* find an idle stripe, make sure it is unhashed, and return it. */
static struct stripe_head *get_free_stripe(struct r5conf *conf, int hash)
{
struct stripe_head *sh = NULL;
struct list_head *first;
if (list_empty(conf->inactive_list + hash))
goto out;
first = (conf->inactive_list + hash)->next;
sh = list_entry(first, struct stripe_head, lru);
list_del_init(first);
remove_hash(sh);
atomic_inc(&conf->active_stripes);
BUG_ON(hash != sh->hash_lock_index);
if (list_empty(conf->inactive_list + hash))
atomic_inc(&conf->empty_inactive_list_nr);
out:
return sh;
}
#if PAGE_SIZE != DEFAULT_STRIPE_SIZE
static void free_stripe_pages(struct stripe_head *sh)
{
int i;
struct page *p;
/* Have not allocate page pool */
if (!sh->pages)
return;
for (i = 0; i < sh->nr_pages; i++) {
p = sh->pages[i];
if (p)
put_page(p);
sh->pages[i] = NULL;
}
}
static int alloc_stripe_pages(struct stripe_head *sh, gfp_t gfp)
{
int i;
struct page *p;
for (i = 0; i < sh->nr_pages; i++) {
/* The page have allocated. */
if (sh->pages[i])
continue;
p = alloc_page(gfp);
if (!p) {
free_stripe_pages(sh);
return -ENOMEM;
}
sh->pages[i] = p;
}
return 0;
}
static int
init_stripe_shared_pages(struct stripe_head *sh, struct r5conf *conf, int disks)
{
int nr_pages, cnt;
if (sh->pages)
return 0;
/* Each of the sh->dev[i] need one conf->stripe_size */
cnt = PAGE_SIZE / conf->stripe_size;
nr_pages = (disks + cnt - 1) / cnt;
sh->pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
if (!sh->pages)
return -ENOMEM;
sh->nr_pages = nr_pages;
sh->stripes_per_page = cnt;
return 0;
}
#endif
static void shrink_buffers(struct stripe_head *sh)
{
int i;
int num = sh->raid_conf->pool_size;
#if PAGE_SIZE == DEFAULT_STRIPE_SIZE
for (i = 0; i < num ; i++) {
struct page *p;
WARN_ON(sh->dev[i].page != sh->dev[i].orig_page);
p = sh->dev[i].page;
if (!p)
continue;
sh->dev[i].page = NULL;
put_page(p);
}
#else
for (i = 0; i < num; i++)
sh->dev[i].page = NULL;
free_stripe_pages(sh); /* Free pages */
#endif
}
static int grow_buffers(struct stripe_head *sh, gfp_t gfp)
{
int i;
int num = sh->raid_conf->pool_size;
#if PAGE_SIZE == DEFAULT_STRIPE_SIZE
for (i = 0; i < num; i++) {
struct page *page;
if (!(page = alloc_page(gfp))) {
return 1;
}
sh->dev[i].page = page;
sh->dev[i].orig_page = page;
sh->dev[i].offset = 0;
}
#else
if (alloc_stripe_pages(sh, gfp))
return -ENOMEM;
for (i = 0; i < num; i++) {
sh->dev[i].page = raid5_get_dev_page(sh, i);
sh->dev[i].orig_page = sh->dev[i].page;
sh->dev[i].offset = raid5_get_page_offset(sh, i);
}
#endif
return 0;
}
static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous,
struct stripe_head *sh);
static void init_stripe(struct stripe_head *sh, sector_t sector, int previous)
{
struct r5conf *conf = sh->raid_conf;
int i, seq;
BUG_ON(atomic_read(&sh->count) != 0);
BUG_ON(test_bit(STRIPE_HANDLE, &sh->state));
BUG_ON(stripe_operations_active(sh));
BUG_ON(sh->batch_head);
pr_debug("init_stripe called, stripe %llu\n",
(unsigned long long)sector);
retry:
seq = read_seqcount_begin(&conf->gen_lock);
sh->generation = conf->generation - previous;
sh->disks = previous ? conf->previous_raid_disks : conf->raid_disks;
sh->sector = sector;
stripe_set_idx(sector, conf, previous, sh);
sh->state = 0;
for (i = sh->disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
if (dev->toread || dev->read || dev->towrite || dev->written ||
test_bit(R5_LOCKED, &dev->flags)) {
pr_err("sector=%llx i=%d %p %p %p %p %d\n",
(unsigned long long)sh->sector, i, dev->toread,
dev->read, dev->towrite, dev->written,
test_bit(R5_LOCKED, &dev->flags));
WARN_ON(1);
}
dev->flags = 0;
dev->sector = raid5_compute_blocknr(sh, i, previous);
}
if (read_seqcount_retry(&conf->gen_lock, seq))
goto retry;
sh->overwrite_disks = 0;
insert_hash(conf, sh);
sh->cpu = smp_processor_id();
set_bit(STRIPE_BATCH_READY, &sh->state);
}
static struct stripe_head *__find_stripe(struct r5conf *conf, sector_t sector,
short generation)
{
struct stripe_head *sh;
pr_debug("__find_stripe, sector %llu\n", (unsigned long long)sector);
hlist_for_each_entry(sh, stripe_hash(conf, sector), hash)
if (sh->sector == sector && sh->generation == generation)
return sh;
pr_debug("__stripe %llu not in cache\n", (unsigned long long)sector);
return NULL;
}
static struct stripe_head *find_get_stripe(struct r5conf *conf,
sector_t sector, short generation, int hash)
{
int inc_empty_inactive_list_flag;
struct stripe_head *sh;
sh = __find_stripe(conf, sector, generation);
if (!sh)
return NULL;
if (atomic_inc_not_zero(&sh->count))
return sh;
/*
* Slow path. The reference count is zero which means the stripe must
* be on a list (sh->lru). Must remove the stripe from the list that
* references it with the device_lock held.
*/
spin_lock(&conf->device_lock);
if (!atomic_read(&sh->count)) {
if (!test_bit(STRIPE_HANDLE, &sh->state))
atomic_inc(&conf->active_stripes);
BUG_ON(list_empty(&sh->lru) &&
!test_bit(STRIPE_EXPANDING, &sh->state));
inc_empty_inactive_list_flag = 0;
if (!list_empty(conf->inactive_list + hash))
inc_empty_inactive_list_flag = 1;
list_del_init(&sh->lru);
if (list_empty(conf->inactive_list + hash) &&
inc_empty_inactive_list_flag)
atomic_inc(&conf->empty_inactive_list_nr);
if (sh->group) {
sh->group->stripes_cnt--;
sh->group = NULL;
}
}
atomic_inc(&sh->count);
spin_unlock(&conf->device_lock);
return sh;
}
/*
* Need to check if array has failed when deciding whether to:
* - start an array
* - remove non-faulty devices
* - add a spare
* - allow a reshape
* This determination is simple when no reshape is happening.
* However if there is a reshape, we need to carefully check
* both the before and after sections.
* This is because some failed devices may only affect one
* of the two sections, and some non-in_sync devices may
* be insync in the section most affected by failed devices.
*
* Most calls to this function hold &conf->device_lock. Calls
* in raid5_run() do not require the lock as no other threads
* have been started yet.
*/
int raid5_calc_degraded(struct r5conf *conf)
{
int degraded, degraded2;
int i;
rcu_read_lock();
degraded = 0;
for (i = 0; i < conf->previous_raid_disks; i++) {
struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);
if (rdev && test_bit(Faulty, &rdev->flags))
rdev = rcu_dereference(conf->disks[i].replacement);
if (!rdev || test_bit(Faulty, &rdev->flags))
degraded++;
else if (test_bit(In_sync, &rdev->flags))
;
else
/* not in-sync or faulty.
* If the reshape increases the number of devices,
* this is being recovered by the reshape, so
* this 'previous' section is not in_sync.
* If the number of devices is being reduced however,
* the device can only be part of the array if
* we are reverting a reshape, so this section will
* be in-sync.
*/
if (conf->raid_disks >= conf->previous_raid_disks)
degraded++;
}
rcu_read_unlock();
if (conf->raid_disks == conf->previous_raid_disks)
return degraded;
rcu_read_lock();
degraded2 = 0;
for (i = 0; i < conf->raid_disks; i++) {
struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);
if (rdev && test_bit(Faulty, &rdev->flags))
rdev = rcu_dereference(conf->disks[i].replacement);
if (!rdev || test_bit(Faulty, &rdev->flags))
degraded2++;
else if (test_bit(In_sync, &rdev->flags))
;
else
/* not in-sync or faulty.
* If reshape increases the number of devices, this
* section has already been recovered, else it
* almost certainly hasn't.
*/
if (conf->raid_disks <= conf->previous_raid_disks)
degraded2++;
}
rcu_read_unlock();
if (degraded2 > degraded)
return degraded2;
return degraded;
}
static bool has_failed(struct r5conf *conf)
{
int degraded = conf->mddev->degraded;
if (test_bit(MD_BROKEN, &conf->mddev->flags))
return true;
if (conf->mddev->reshape_position != MaxSector)
degraded = raid5_calc_degraded(conf);
return degraded > conf->max_degraded;
}
enum stripe_result {
STRIPE_SUCCESS = 0,
STRIPE_RETRY,
STRIPE_SCHEDULE_AND_RETRY,
STRIPE_FAIL,
};
struct stripe_request_ctx {
/* a reference to the last stripe_head for batching */
struct stripe_head *batch_last;
/* first sector in the request */
sector_t first_sector;
/* last sector in the request */
sector_t last_sector;
/*
* bitmap to track stripe sectors that have been added to stripes
* add one to account for unaligned requests
*/
DECLARE_BITMAP(sectors_to_do, RAID5_MAX_REQ_STRIPES + 1);
/* the request had REQ_PREFLUSH, cleared after the first stripe_head */
bool do_flush;
};
/*
* Block until another thread clears R5_INACTIVE_BLOCKED or
* there are fewer than 3/4 the maximum number of active stripes
* and there is an inactive stripe available.
*/
static bool is_inactive_blocked(struct r5conf *conf, int hash)
{
if (list_empty(conf->inactive_list + hash))
return false;
if (!test_bit(R5_INACTIVE_BLOCKED, &conf->cache_state))
return true;
return (atomic_read(&conf->active_stripes) <
(conf->max_nr_stripes * 3 / 4));
}
struct stripe_head *raid5_get_active_stripe(struct r5conf *conf,
struct stripe_request_ctx *ctx, sector_t sector,
unsigned int flags)
{
struct stripe_head *sh;
int hash = stripe_hash_locks_hash(conf, sector);
int previous = !!(flags & R5_GAS_PREVIOUS);
pr_debug("get_stripe, sector %llu\n", (unsigned long long)sector);
spin_lock_irq(conf->hash_locks + hash);
for (;;) {
if (!(flags & R5_GAS_NOQUIESCE) && conf->quiesce) {
/*
* Must release the reference to batch_last before
* waiting, on quiesce, otherwise the batch_last will
* hold a reference to a stripe and raid5_quiesce()
* will deadlock waiting for active_stripes to go to
* zero.
*/
if (ctx && ctx->batch_last) {
raid5_release_stripe(ctx->batch_last);
ctx->batch_last = NULL;
}
wait_event_lock_irq(conf->wait_for_quiescent,
!conf->quiesce,
*(conf->hash_locks + hash));
}
sh = find_get_stripe(conf, sector, conf->generation - previous,
hash);
if (sh)
break;
if (!test_bit(R5_INACTIVE_BLOCKED, &conf->cache_state)) {
sh = get_free_stripe(conf, hash);
if (sh) {
r5c_check_stripe_cache_usage(conf);
init_stripe(sh, sector, previous);
atomic_inc(&sh->count);
break;
}
if (!test_bit(R5_DID_ALLOC, &conf->cache_state))
set_bit(R5_ALLOC_MORE, &conf->cache_state);
}
if (flags & R5_GAS_NOBLOCK)
break;
set_bit(R5_INACTIVE_BLOCKED, &conf->cache_state);
r5l_wake_reclaim(conf->log, 0);
wait_event_lock_irq(conf->wait_for_stripe,
is_inactive_blocked(conf, hash),
*(conf->hash_locks + hash));
clear_bit(R5_INACTIVE_BLOCKED, &conf->cache_state);
}
spin_unlock_irq(conf->hash_locks + hash);
return sh;
}
static bool is_full_stripe_write(struct stripe_head *sh)
{
BUG_ON(sh->overwrite_disks > (sh->disks - sh->raid_conf->max_degraded));
return sh->overwrite_disks == (sh->disks - sh->raid_conf->max_degraded);
}
static void lock_two_stripes(struct stripe_head *sh1, struct stripe_head *sh2)
__acquires(&sh1->stripe_lock)
__acquires(&sh2->stripe_lock)
{
if (sh1 > sh2) {
spin_lock_irq(&sh2->stripe_lock);
spin_lock_nested(&sh1->stripe_lock, 1);
} else {
spin_lock_irq(&sh1->stripe_lock);
spin_lock_nested(&sh2->stripe_lock, 1);
}
}
static void unlock_two_stripes(struct stripe_head *sh1, struct stripe_head *sh2)
__releases(&sh1->stripe_lock)
__releases(&sh2->stripe_lock)
{
spin_unlock(&sh1->stripe_lock);
spin_unlock_irq(&sh2->stripe_lock);
}
/* Only freshly new full stripe normal write stripe can be added to a batch list */
static bool stripe_can_batch(struct stripe_head *sh)
{
struct r5conf *conf = sh->raid_conf;
if (raid5_has_log(conf) || raid5_has_ppl(conf))
return false;
return test_bit(STRIPE_BATCH_READY, &sh->state) &&
!test_bit(STRIPE_BITMAP_PENDING, &sh->state) &&
is_full_stripe_write(sh);
}
/* we only do back search */
static void stripe_add_to_batch_list(struct r5conf *conf,
struct stripe_head *sh, struct stripe_head *last_sh)
{
struct stripe_head *head;
sector_t head_sector, tmp_sec;
int hash;
int dd_idx;
/* Don't cross chunks, so stripe pd_idx/qd_idx is the same */
tmp_sec = sh->sector;
if (!sector_div(tmp_sec, conf->chunk_sectors))
return;
head_sector = sh->sector - RAID5_STRIPE_SECTORS(conf);
if (last_sh && head_sector == last_sh->sector) {
head = last_sh;
atomic_inc(&head->count);
} else {
hash = stripe_hash_locks_hash(conf, head_sector);
spin_lock_irq(conf->hash_locks + hash);
head = find_get_stripe(conf, head_sector, conf->generation,
hash);
spin_unlock_irq(conf->hash_locks + hash);
if (!head)
return;
if (!stripe_can_batch(head))
goto out;
}
lock_two_stripes(head, sh);
/* clear_batch_ready clear the flag */
if (!stripe_can_batch(head) || !stripe_can_batch(sh))
goto unlock_out;
if (sh->batch_head)
goto unlock_out;
dd_idx = 0;
while (dd_idx == sh->pd_idx || dd_idx == sh->qd_idx)
dd_idx++;
if (head->dev[dd_idx].towrite->bi_opf != sh->dev[dd_idx].towrite->bi_opf ||
bio_op(head->dev[dd_idx].towrite) != bio_op(sh->dev[dd_idx].towrite))
goto unlock_out;
if (head->batch_head) {
spin_lock(&head->batch_head->batch_lock);
/* This batch list is already running */
if (!stripe_can_batch(head)) {
spin_unlock(&head->batch_head->batch_lock);
goto unlock_out;
}
/*
* We must assign batch_head of this stripe within the
* batch_lock, otherwise clear_batch_ready of batch head
* stripe could clear BATCH_READY bit of this stripe and
* this stripe->batch_head doesn't get assigned, which
* could confuse clear_batch_ready for this stripe
*/
sh->batch_head = head->batch_head;
/*
* at this point, head's BATCH_READY could be cleared, but we
* can still add the stripe to batch list
*/
list_add(&sh->batch_list, &head->batch_list);
spin_unlock(&head->batch_head->batch_lock);
} else {
head->batch_head = head;
sh->batch_head = head->batch_head;
spin_lock(&head->batch_lock);
list_add_tail(&sh->batch_list, &head->batch_list);
spin_unlock(&head->batch_lock);
}
if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
if (atomic_dec_return(&conf->preread_active_stripes)
< IO_THRESHOLD)
md_wakeup_thread(conf->mddev->thread);
if (test_and_clear_bit(STRIPE_BIT_DELAY, &sh->state)) {
int seq = sh->bm_seq;
if (test_bit(STRIPE_BIT_DELAY, &sh->batch_head->state) &&
sh->batch_head->bm_seq > seq)
seq = sh->batch_head->bm_seq;
set_bit(STRIPE_BIT_DELAY, &sh->batch_head->state);
sh->batch_head->bm_seq = seq;
}
atomic_inc(&sh->count);
unlock_out:
unlock_two_stripes(head, sh);
out:
raid5_release_stripe(head);
}
/* Determine if 'data_offset' or 'new_data_offset' should be used
* in this stripe_head.
*/
static int use_new_offset(struct r5conf *conf, struct stripe_head *sh)
{
sector_t progress = conf->reshape_progress;
/* Need a memory barrier to make sure we see the value
* of conf->generation, or ->data_offset that was set before
* reshape_progress was updated.
*/
smp_rmb();
if (progress == MaxSector)
return 0;
if (sh->generation == conf->generation - 1)
return 0;
/* We are in a reshape, and this is a new-generation stripe,
* so use new_data_offset.
*/
return 1;
}
static void dispatch_bio_list(struct bio_list *tmp)
{
struct bio *bio;
while ((bio = bio_list_pop(tmp)))
submit_bio_noacct(bio);
}
static int cmp_stripe(void *priv, const struct list_head *a,
const struct list_head *b)
{
const struct r5pending_data *da = list_entry(a,
struct r5pending_data, sibling);
const struct r5pending_data *db = list_entry(b,
struct r5pending_data, sibling);
if (da->sector > db->sector)
return 1;
if (da->sector < db->sector)
return -1;
return 0;
}
static void dispatch_defer_bios(struct r5conf *conf, int target,
struct bio_list *list)
{
struct r5pending_data *data;
struct list_head *first, *next = NULL;
int cnt = 0;
if (conf->pending_data_cnt == 0)
return;
list_sort(NULL, &conf->pending_list, cmp_stripe);
first = conf->pending_list.next;
/* temporarily move the head */
if (conf->next_pending_data)
list_move_tail(&conf->pending_list,
&conf->next_pending_data->sibling);
while (!list_empty(&conf->pending_list)) {
data = list_first_entry(&conf->pending_list,
struct r5pending_data, sibling);
if (&data->sibling == first)
first = data->sibling.next;
next = data->sibling.next;
bio_list_merge(list, &data->bios);
list_move(&data->sibling, &conf->free_list);
cnt++;
if (cnt >= target)
break;
}
conf->pending_data_cnt -= cnt;
BUG_ON(conf->pending_data_cnt < 0 || cnt < target);
if (next != &conf->pending_list)
conf->next_pending_data = list_entry(next,
struct r5pending_data, sibling);
else
conf->next_pending_data = NULL;
/* list isn't empty */
if (first != &conf->pending_list)
list_move_tail(&conf->pending_list, first);
}
static void flush_deferred_bios(struct r5conf *conf)
{
struct bio_list tmp = BIO_EMPTY_LIST;
if (conf->pending_data_cnt == 0)
return;
spin_lock(&conf->pending_bios_lock);
dispatch_defer_bios(conf, conf->pending_data_cnt, &tmp);
BUG_ON(conf->pending_data_cnt != 0);
spin_unlock(&conf->pending_bios_lock);
dispatch_bio_list(&tmp);
}
static void defer_issue_bios(struct r5conf *conf, sector_t sector,
struct bio_list *bios)
{
struct bio_list tmp = BIO_EMPTY_LIST;
struct r5pending_data *ent;
spin_lock(&conf->pending_bios_lock);
ent = list_first_entry(&conf->free_list, struct r5pending_data,
sibling);
list_move_tail(&ent->sibling, &conf->pending_list);
ent->sector = sector;
bio_list_init(&ent->bios);
bio_list_merge(&ent->bios, bios);
conf->pending_data_cnt++;
if (conf->pending_data_cnt >= PENDING_IO_MAX)
dispatch_defer_bios(conf, PENDING_IO_ONE_FLUSH, &tmp);
spin_unlock(&conf->pending_bios_lock);
dispatch_bio_list(&tmp);
}
static void
raid5_end_read_request(struct bio *bi);
static void
raid5_end_write_request(struct bio *bi);
static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
{
struct r5conf *conf = sh->raid_conf;
int i, disks = sh->disks;
struct stripe_head *head_sh = sh;
struct bio_list pending_bios = BIO_EMPTY_LIST;
struct r5dev *dev;
bool should_defer;
might_sleep();
if (log_stripe(sh, s) == 0)
return;
should_defer = conf->batch_bio_dispatch && conf->group_cnt;
for (i = disks; i--; ) {
enum req_op op;
blk_opf_t op_flags = 0;
int replace_only = 0;
struct bio *bi, *rbi;
struct md_rdev *rdev, *rrdev = NULL;
sh = head_sh;
if (test_and_clear_bit(R5_Wantwrite, &sh->dev[i].flags)) {
op = REQ_OP_WRITE;
if (test_and_clear_bit(R5_WantFUA, &sh->dev[i].flags))
op_flags = REQ_FUA;
if (test_bit(R5_Discard, &sh->dev[i].flags))
op = REQ_OP_DISCARD;
} else if (test_and_clear_bit(R5_Wantread, &sh->dev[i].flags))
op = REQ_OP_READ;
else if (test_and_clear_bit(R5_WantReplace,
&sh->dev[i].flags)) {
op = REQ_OP_WRITE;
replace_only = 1;
} else
continue;
if (test_and_clear_bit(R5_SyncIO, &sh->dev[i].flags))
op_flags |= REQ_SYNC;
again:
dev = &sh->dev[i];
bi = &dev->req;
rbi = &dev->rreq; /* For writing to replacement */
rcu_read_lock();
rrdev = rcu_dereference(conf->disks[i].replacement);
smp_mb(); /* Ensure that if rrdev is NULL, rdev won't be */
rdev = rcu_dereference(conf->disks[i].rdev);
if (!rdev) {
rdev = rrdev;
rrdev = NULL;
}
if (op_is_write(op)) {
if (replace_only)
rdev = NULL;
if (rdev == rrdev)
/* We raced and saw duplicates */
rrdev = NULL;
} else {
if (test_bit(R5_ReadRepl, &head_sh->dev[i].flags) && rrdev)
rdev = rrdev;
rrdev = NULL;
}
if (rdev && test_bit(Faulty, &rdev->flags))
rdev = NULL;
if (rdev)
atomic_inc(&rdev->nr_pending);
if (rrdev && test_bit(Faulty, &rrdev->flags))
rrdev = NULL;
if (rrdev)
atomic_inc(&rrdev->nr_pending);
rcu_read_unlock();
/* We have already checked bad blocks for reads. Now
* need to check for writes. We never accept write errors
* on the replacement, so we don't to check rrdev.
*/
while (op_is_write(op) && rdev &&
test_bit(WriteErrorSeen, &rdev->flags)) {
sector_t first_bad;
int bad_sectors;
int bad = is_badblock(rdev, sh->sector, RAID5_STRIPE_SECTORS(conf),
&first_bad, &bad_sectors);
if (!bad)
break;
if (bad < 0) {
set_bit(BlockedBadBlocks, &rdev->flags);
if (!conf->mddev->external &&
conf->mddev->sb_flags) {
/* It is very unlikely, but we might
* still need to write out the
* bad block log - better give it
* a chance*/
md_check_recovery(conf->mddev);
}
/*
* Because md_wait_for_blocked_rdev
* will dec nr_pending, we must
* increment it first.
*/
atomic_inc(&rdev->nr_pending);
md_wait_for_blocked_rdev(rdev, conf->mddev);
} else {
/* Acknowledged bad block - skip the write */
rdev_dec_pending(rdev, conf->mddev);
rdev = NULL;
}
}
if (rdev) {
if (s->syncing || s->expanding || s->expanded
|| s->replacing)
md_sync_acct(rdev->bdev, RAID5_STRIPE_SECTORS(conf));
set_bit(STRIPE_IO_STARTED, &sh->state);
bio_init(bi, rdev->bdev, &dev->vec, 1, op | op_flags);
bi->bi_end_io = op_is_write(op)
? raid5_end_write_request
: raid5_end_read_request;
bi->bi_private = sh;
pr_debug("%s: for %llu schedule op %d on disc %d\n",
__func__, (unsigned long long)sh->sector,
bi->bi_opf, i);
atomic_inc(&sh->count);
if (sh != head_sh)
atomic_inc(&head_sh->count);
if (use_new_offset(conf, sh))
bi->bi_iter.bi_sector = (sh->sector
+ rdev->new_data_offset);
else
bi->bi_iter.bi_sector = (sh->sector
+ rdev->data_offset);
if (test_bit(R5_ReadNoMerge, &head_sh->dev[i].flags))
bi->bi_opf |= REQ_NOMERGE;
if (test_bit(R5_SkipCopy, &sh->dev[i].flags))
WARN_ON(test_bit(R5_UPTODATE, &sh->dev[i].flags));
if (!op_is_write(op) &&
test_bit(R5_InJournal, &sh->dev[i].flags))
/*
* issuing read for a page in journal, this
* must be preparing for prexor in rmw; read
* the data into orig_page
*/
sh->dev[i].vec.bv_page = sh->dev[i].orig_page;
else
sh->dev[i].vec.bv_page = sh->dev[i].page;
bi->bi_vcnt = 1;
bi->bi_io_vec[0].bv_len = RAID5_STRIPE_SIZE(conf);
bi->bi_io_vec[0].bv_offset = sh->dev[i].offset;
bi->bi_iter.bi_size = RAID5_STRIPE_SIZE(conf);
/*
* If this is discard request, set bi_vcnt 0. We don't
* want to confuse SCSI because SCSI will replace payload
*/
if (op == REQ_OP_DISCARD)
bi->bi_vcnt = 0;
if (rrdev)
set_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags);
if (conf->mddev->gendisk)
trace_block_bio_remap(bi,
disk_devt(conf->mddev->gendisk),
sh->dev[i].sector);
if (should_defer && op_is_write(op))
bio_list_add(&pending_bios, bi);
else
submit_bio_noacct(bi);
}
if (rrdev) {
if (s->syncing || s->expanding || s->expanded
|| s->replacing)
md_sync_acct(rrdev->bdev, RAID5_STRIPE_SECTORS(conf));
set_bit(STRIPE_IO_STARTED, &sh->state);
bio_init(rbi, rrdev->bdev, &dev->rvec, 1, op | op_flags);
BUG_ON(!op_is_write(op));
rbi->bi_end_io = raid5_end_write_request;
rbi->bi_private = sh;
pr_debug("%s: for %llu schedule op %d on "
"replacement disc %d\n",
__func__, (unsigned long long)sh->sector,
rbi->bi_opf, i);
atomic_inc(&sh->count);
if (sh != head_sh)
atomic_inc(&head_sh->count);
if (use_new_offset(conf, sh))
rbi->bi_iter.bi_sector = (sh->sector
+ rrdev->new_data_offset);
else
rbi->bi_iter.bi_sector = (sh->sector
+ rrdev->data_offset);
if (test_bit(R5_SkipCopy, &sh->dev[i].flags))
WARN_ON(test_bit(R5_UPTODATE, &sh->dev[i].flags));
sh->dev[i].rvec.bv_page = sh->dev[i].page;
rbi->bi_vcnt = 1;
rbi->bi_io_vec[0].bv_len = RAID5_STRIPE_SIZE(conf);
rbi->bi_io_vec[0].bv_offset = sh->dev[i].offset;
rbi->bi_iter.bi_size = RAID5_STRIPE_SIZE(conf);
/*
* If this is discard request, set bi_vcnt 0. We don't
* want to confuse SCSI because SCSI will replace payload
*/
if (op == REQ_OP_DISCARD)
rbi->bi_vcnt = 0;
if (conf->mddev->gendisk)
trace_block_bio_remap(rbi,
disk_devt(conf->mddev->gendisk),
sh->dev[i].sector);
if (should_defer && op_is_write(op))
bio_list_add(&pending_bios, rbi);
else
submit_bio_noacct(rbi);
}
if (!rdev && !rrdev) {
if (op_is_write(op))
set_bit(STRIPE_DEGRADED, &sh->state);
pr_debug("skip op %d on disc %d for sector %llu\n",
bi->bi_opf, i, (unsigned long long)sh->sector);
clear_bit(R5_LOCKED, &sh->dev[i].flags);
set_bit(STRIPE_HANDLE, &sh->state);
}
if (!head_sh->batch_head)
continue;
sh = list_first_entry(&sh->batch_list, struct stripe_head,
batch_list);
if (sh != head_sh)
goto again;
}
if (should_defer && !bio_list_empty(&pending_bios))
defer_issue_bios(conf, head_sh->sector, &pending_bios);
}
static struct dma_async_tx_descriptor *
async_copy_data(int frombio, struct bio *bio, struct page **page,
unsigned int poff, sector_t sector, struct dma_async_tx_descriptor *tx,
struct stripe_head *sh, int no_skipcopy)
{
struct bio_vec bvl;
struct bvec_iter iter;
struct page *bio_page;
int page_offset;
struct async_submit_ctl submit;
enum async_tx_flags flags = 0;
struct r5conf *conf = sh->raid_conf;
if (bio->bi_iter.bi_sector >= sector)
page_offset = (signed)(bio->bi_iter.bi_sector - sector) * 512;
else
page_offset = (signed)(sector - bio->bi_iter.bi_sector) * -512;
if (frombio)
flags |= ASYNC_TX_FENCE;
init_async_submit(&submit, flags, tx, NULL, NULL, NULL);
bio_for_each_segment(bvl, bio, iter) {
int len = bvl.bv_len;
int clen;
int b_offset = 0;
if (page_offset < 0) {
b_offset = -page_offset;
page_offset += b_offset;
len -= b_offset;
}
if (len > 0 && page_offset + len > RAID5_STRIPE_SIZE(conf))
clen = RAID5_STRIPE_SIZE(conf) - page_offset;
else
clen = len;
if (clen > 0) {
b_offset += bvl.bv_offset;
bio_page = bvl.bv_page;
if (frombio) {
if (conf->skip_copy &&
b_offset == 0 && page_offset == 0 &&
clen == RAID5_STRIPE_SIZE(conf) &&
!no_skipcopy)
*page = bio_page;
else
tx = async_memcpy(*page, bio_page, page_offset + poff,
b_offset, clen, &submit);
} else
tx = async_memcpy(bio_page, *page, b_offset,
page_offset + poff, clen, &submit);
}
/* chain the operations */
submit.depend_tx = tx;
if (clen < len) /* hit end of page */
break;
page_offset += len;
}
return tx;
}
static void ops_complete_biofill(void *stripe_head_ref)
{
struct stripe_head *sh = stripe_head_ref;
int i;
struct r5conf *conf = sh->raid_conf;
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
/* clear completed biofills */
for (i = sh->disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
/* acknowledge completion of a biofill operation */
/* and check if we need to reply to a read request,
* new R5_Wantfill requests are held off until
* !STRIPE_BIOFILL_RUN
*/
if (test_and_clear_bit(R5_Wantfill, &dev->flags)) {
struct bio *rbi, *rbi2;
BUG_ON(!dev->read);
rbi = dev->read;
dev->read = NULL;
while (rbi && rbi->bi_iter.bi_sector <
dev->sector + RAID5_STRIPE_SECTORS(conf)) {
rbi2 = r5_next_bio(conf, rbi, dev->sector);
bio_endio(rbi);
rbi = rbi2;
}
}
}
clear_bit(STRIPE_BIOFILL_RUN, &sh->state);
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
}
static void ops_run_biofill(struct stripe_head *sh)
{
struct dma_async_tx_descriptor *tx = NULL;
struct async_submit_ctl submit;
int i;
struct r5conf *conf = sh->raid_conf;
BUG_ON(sh->batch_head);
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
for (i = sh->disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
if (test_bit(R5_Wantfill, &dev->flags)) {
struct bio *rbi;
spin_lock_irq(&sh->stripe_lock);
dev->read = rbi = dev->toread;
dev->toread = NULL;
spin_unlock_irq(&sh->stripe_lock);
while (rbi && rbi->bi_iter.bi_sector <
dev->sector + RAID5_STRIPE_SECTORS(conf)) {
tx = async_copy_data(0, rbi, &dev->page,
dev->offset,
dev->sector, tx, sh, 0);
rbi = r5_next_bio(conf, rbi, dev->sector);
}
}
}
atomic_inc(&sh->count);
init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_biofill, sh, NULL);
async_trigger_callback(&submit);
}
static void mark_target_uptodate(struct stripe_head *sh, int target)
{
struct r5dev *tgt;
if (target < 0)
return;
tgt = &sh->dev[target];
set_bit(R5_UPTODATE, &tgt->flags);
BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
clear_bit(R5_Wantcompute, &tgt->flags);
}
static void ops_complete_compute(void *stripe_head_ref)
{
struct stripe_head *sh = stripe_head_ref;
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
/* mark the computed target(s) as uptodate */
mark_target_uptodate(sh, sh->ops.target);
mark_target_uptodate(sh, sh->ops.target2);
clear_bit(STRIPE_COMPUTE_RUN, &sh->state);
if (sh->check_state == check_state_compute_run)
sh->check_state = check_state_compute_result;
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
}
/* return a pointer to the address conversion region of the scribble buffer */
static struct page **to_addr_page(struct raid5_percpu *percpu, int i)
{
return percpu->scribble + i * percpu->scribble_obj_size;
}
/* return a pointer to the address conversion region of the scribble buffer */
static addr_conv_t *to_addr_conv(struct stripe_head *sh,
struct raid5_percpu *percpu, int i)
{
return (void *) (to_addr_page(percpu, i) + sh->disks + 2);
}
/*
* Return a pointer to record offset address.
*/
static unsigned int *
to_addr_offs(struct stripe_head *sh, struct raid5_percpu *percpu)
{
return (unsigned int *) (to_addr_conv(sh, percpu, 0) + sh->disks + 2);
}
static struct dma_async_tx_descriptor *
ops_run_compute5(struct stripe_head *sh, struct raid5_percpu *percpu)
{
int disks = sh->disks;
struct page **xor_srcs = to_addr_page(percpu, 0);
unsigned int *off_srcs = to_addr_offs(sh, percpu);
int target = sh->ops.target;
struct r5dev *tgt = &sh->dev[target];
struct page *xor_dest = tgt->page;
unsigned int off_dest = tgt->offset;
int count = 0;
struct dma_async_tx_descriptor *tx;
struct async_submit_ctl submit;
int i;
BUG_ON(sh->batch_head);
pr_debug("%s: stripe %llu block: %d\n",
__func__, (unsigned long long)sh->sector, target);
BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
for (i = disks; i--; ) {
if (i != target) {
off_srcs[count] = sh->dev[i].offset;
xor_srcs[count++] = sh->dev[i].page;
}
}
atomic_inc(&sh->count);
init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST, NULL,
ops_complete_compute, sh, to_addr_conv(sh, percpu, 0));
if (unlikely(count == 1))
tx = async_memcpy(xor_dest, xor_srcs[0], off_dest, off_srcs[0],
RAID5_STRIPE_SIZE(sh->raid_conf), &submit);
else
tx = async_xor_offs(xor_dest, off_dest, xor_srcs, off_srcs, count,
RAID5_STRIPE_SIZE(sh->raid_conf), &submit);
return tx;
}
/* set_syndrome_sources - populate source buffers for gen_syndrome
* @srcs - (struct page *) array of size sh->disks
* @offs - (unsigned int) array of offset for each page
* @sh - stripe_head to parse
*
* Populates srcs in proper layout order for the stripe and returns the
* 'count' of sources to be used in a call to async_gen_syndrome. The P
* destination buffer is recorded in srcs[count] and the Q destination
* is recorded in srcs[count+1]].
*/
static int set_syndrome_sources(struct page **srcs,
unsigned int *offs,
struct stripe_head *sh,
int srctype)
{
int disks = sh->disks;
int syndrome_disks = sh->ddf_layout ? disks : (disks - 2);
int d0_idx = raid6_d0(sh);
int count;
int i;
for (i = 0; i < disks; i++)
srcs[i] = NULL;
count = 0;
i = d0_idx;
do {
int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
struct r5dev *dev = &sh->dev[i];
if (i == sh->qd_idx || i == sh->pd_idx ||
(srctype == SYNDROME_SRC_ALL) ||
(srctype == SYNDROME_SRC_WANT_DRAIN &&
(test_bit(R5_Wantdrain, &dev->flags) ||
test_bit(R5_InJournal, &dev->flags))) ||
(srctype == SYNDROME_SRC_WRITTEN &&
(dev->written ||
test_bit(R5_InJournal, &dev->flags)))) {
if (test_bit(R5_InJournal, &dev->flags))
srcs[slot] = sh->dev[i].orig_page;
else
srcs[slot] = sh->dev[i].page;
/*
* For R5_InJournal, PAGE_SIZE must be 4KB and will
* not shared page. In that case, dev[i].offset
* is 0.
*/
offs[slot] = sh->dev[i].offset;
}
i = raid6_next_disk(i, disks);
} while (i != d0_idx);
return syndrome_disks;
}
static struct dma_async_tx_descriptor *
ops_run_compute6_1(struct stripe_head *sh, struct raid5_percpu *percpu)
{
int disks = sh->disks;
struct page **blocks = to_addr_page(percpu, 0);
unsigned int *offs = to_addr_offs(sh, percpu);
int target;
int qd_idx = sh->qd_idx;
struct dma_async_tx_descriptor *tx;
struct async_submit_ctl submit;
struct r5dev *tgt;
struct page *dest;
unsigned int dest_off;
int i;
int count;
BUG_ON(sh->batch_head);
if (sh->ops.target < 0)
target = sh->ops.target2;
else if (sh->ops.target2 < 0)
target = sh->ops.target;
else
/* we should only have one valid target */
BUG();
BUG_ON(target < 0);
pr_debug("%s: stripe %llu block: %d\n",
__func__, (unsigned long long)sh->sector, target);
tgt = &sh->dev[target];
BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
dest = tgt->page;
dest_off = tgt->offset;
atomic_inc(&sh->count);
if (target == qd_idx) {
count = set_syndrome_sources(blocks, offs, sh, SYNDROME_SRC_ALL);
blocks[count] = NULL; /* regenerating p is not necessary */
BUG_ON(blocks[count+1] != dest); /* q should already be set */
init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
ops_complete_compute, sh,
to_addr_conv(sh, percpu, 0));
tx = async_gen_syndrome(blocks, offs, count+2,
RAID5_STRIPE_SIZE(sh->raid_conf), &submit);
} else {
/* Compute any data- or p-drive using XOR */
count = 0;
for (i = disks; i-- ; ) {
if (i == target || i == qd_idx)
continue;
offs[count] = sh->dev[i].offset;
blocks[count++] = sh->dev[i].page;
}
init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
NULL, ops_complete_compute, sh,
to_addr_conv(sh, percpu, 0));
tx = async_xor_offs(dest, dest_off, blocks, offs, count,
RAID5_STRIPE_SIZE(sh->raid_conf), &submit);
}
return tx;
}
static struct dma_async_tx_descriptor *
ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu)
{
int i, count, disks = sh->disks;
int syndrome_disks = sh->ddf_layout ? disks : disks-2;
int d0_idx = raid6_d0(sh);
int faila = -1, failb = -1;
int target = sh->ops.target;
int target2 = sh->ops.target2;
struct r5dev *tgt = &sh->dev[target];
struct r5dev *tgt2 = &sh->dev[target2];
struct dma_async_tx_descriptor *tx;
struct page **blocks = to_addr_page(percpu, 0);
unsigned int *offs = to_addr_offs(sh, percpu);
struct async_submit_ctl submit;
BUG_ON(sh->batch_head);
pr_debug("%s: stripe %llu block1: %d block2: %d\n",
__func__, (unsigned long long)sh->sector, target, target2);
BUG_ON(target < 0 || target2 < 0);
BUG_ON(!test_bit(R5_Wantcompute, &tgt->flags));
BUG_ON(!test_bit(R5_Wantcompute, &tgt2->flags));
/* we need to open-code set_syndrome_sources to handle the
* slot number conversion for 'faila' and 'failb'
*/
for (i = 0; i < disks ; i++) {
offs[i] = 0;
blocks[i] = NULL;
}
count = 0;
i = d0_idx;
do {
int slot = raid6_idx_to_slot(i, sh, &count, syndrome_disks);
offs[slot] = sh->dev[i].offset;
blocks[slot] = sh->dev[i].page;
if (i == target)
faila = slot;
if (i == target2)
failb = slot;
i = raid6_next_disk(i, disks);
} while (i != d0_idx);
BUG_ON(faila == failb);
if (failb < faila)
swap(faila, failb);
pr_debug("%s: stripe: %llu faila: %d failb: %d\n",
__func__, (unsigned long long)sh->sector, faila, failb);
atomic_inc(&sh->count);
if (failb == syndrome_disks+1) {
/* Q disk is one of the missing disks */
if (faila == syndrome_disks) {
/* Missing P+Q, just recompute */
init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
ops_complete_compute, sh,
to_addr_conv(sh, percpu, 0));
return async_gen_syndrome(blocks, offs, syndrome_disks+2,
RAID5_STRIPE_SIZE(sh->raid_conf),
&submit);
} else {
struct page *dest;
unsigned int dest_off;
int data_target;
int qd_idx = sh->qd_idx;
/* Missing D+Q: recompute D from P, then recompute Q */
if (target == qd_idx)
data_target = target2;
else
data_target = target;
count = 0;
for (i = disks; i-- ; ) {
if (i == data_target || i == qd_idx)
continue;
offs[count] = sh->dev[i].offset;
blocks[count++] = sh->dev[i].page;
}
dest = sh->dev[data_target].page;
dest_off = sh->dev[data_target].offset;
init_async_submit(&submit,
ASYNC_TX_FENCE|ASYNC_TX_XOR_ZERO_DST,
NULL, NULL, NULL,
to_addr_conv(sh, percpu, 0));
tx = async_xor_offs(dest, dest_off, blocks, offs, count,
RAID5_STRIPE_SIZE(sh->raid_conf),
&submit);
count = set_syndrome_sources(blocks, offs, sh, SYNDROME_SRC_ALL);
init_async_submit(&submit, ASYNC_TX_FENCE, tx,
ops_complete_compute, sh,
to_addr_conv(sh, percpu, 0));
return async_gen_syndrome(blocks, offs, count+2,
RAID5_STRIPE_SIZE(sh->raid_conf),
&submit);
}
} else {
init_async_submit(&submit, ASYNC_TX_FENCE, NULL,
ops_complete_compute, sh,
to_addr_conv(sh, percpu, 0));
if (failb == syndrome_disks) {
/* We're missing D+P. */
return async_raid6_datap_recov(syndrome_disks+2,
RAID5_STRIPE_SIZE(sh->raid_conf),
faila,
blocks, offs, &submit);
} else {
/* We're missing D+D. */
return async_raid6_2data_recov(syndrome_disks+2,
RAID5_STRIPE_SIZE(sh->raid_conf),
faila, failb,
blocks, offs, &submit);
}
}
}
static void ops_complete_prexor(void *stripe_head_ref)
{
struct stripe_head *sh = stripe_head_ref;
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
if (r5c_is_writeback(sh->raid_conf->log))
/*
* raid5-cache write back uses orig_page during prexor.
* After prexor, it is time to free orig_page
*/
r5c_release_extra_page(sh);
}
static struct dma_async_tx_descriptor *
ops_run_prexor5(struct stripe_head *sh, struct raid5_percpu *percpu,
struct dma_async_tx_descriptor *tx)
{
int disks = sh->disks;
struct page **xor_srcs = to_addr_page(percpu, 0);
unsigned int *off_srcs = to_addr_offs(sh, percpu);
int count = 0, pd_idx = sh->pd_idx, i;
struct async_submit_ctl submit;
/* existing parity data subtracted */
unsigned int off_dest = off_srcs[count] = sh->dev[pd_idx].offset;
struct page *xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
BUG_ON(sh->batch_head);
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
/* Only process blocks that are known to be uptodate */
if (test_bit(R5_InJournal, &dev->flags)) {
/*
* For this case, PAGE_SIZE must be equal to 4KB and
* page offset is zero.
*/
off_srcs[count] = dev->offset;
xor_srcs[count++] = dev->orig_page;
} else if (test_bit(R5_Wantdrain, &dev->flags)) {
off_srcs[count] = dev->offset;
xor_srcs[count++] = dev->page;
}
}
init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
ops_complete_prexor, sh, to_addr_conv(sh, percpu, 0));
tx = async_xor_offs(xor_dest, off_dest, xor_srcs, off_srcs, count,
RAID5_STRIPE_SIZE(sh->raid_conf), &submit);
return tx;
}
static struct dma_async_tx_descriptor *
ops_run_prexor6(struct stripe_head *sh, struct raid5_percpu *percpu,
struct dma_async_tx_descriptor *tx)
{
struct page **blocks = to_addr_page(percpu, 0);
unsigned int *offs = to_addr_offs(sh, percpu);
int count;
struct async_submit_ctl submit;
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
count = set_syndrome_sources(blocks, offs, sh, SYNDROME_SRC_WANT_DRAIN);
init_async_submit(&submit, ASYNC_TX_FENCE|ASYNC_TX_PQ_XOR_DST, tx,
ops_complete_prexor, sh, to_addr_conv(sh, percpu, 0));
tx = async_gen_syndrome(blocks, offs, count+2,
RAID5_STRIPE_SIZE(sh->raid_conf), &submit);
return tx;
}
static struct dma_async_tx_descriptor *
ops_run_biodrain(struct stripe_head *sh, struct dma_async_tx_descriptor *tx)
{
struct r5conf *conf = sh->raid_conf;
int disks = sh->disks;
int i;
struct stripe_head *head_sh = sh;
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
for (i = disks; i--; ) {
struct r5dev *dev;
struct bio *chosen;
sh = head_sh;
if (test_and_clear_bit(R5_Wantdrain, &head_sh->dev[i].flags)) {
struct bio *wbi;
again:
dev = &sh->dev[i];
/*
* clear R5_InJournal, so when rewriting a page in
* journal, it is not skipped by r5l_log_stripe()
*/
clear_bit(R5_InJournal, &dev->flags);
spin_lock_irq(&sh->stripe_lock);
chosen = dev->towrite;
dev->towrite = NULL;
sh->overwrite_disks = 0;
BUG_ON(dev->written);
wbi = dev->written = chosen;
spin_unlock_irq(&sh->stripe_lock);
WARN_ON(dev->page != dev->orig_page);
while (wbi && wbi->bi_iter.bi_sector <
dev->sector + RAID5_STRIPE_SECTORS(conf)) {
if (wbi->bi_opf & REQ_FUA)
set_bit(R5_WantFUA, &dev->flags);
if (wbi->bi_opf & REQ_SYNC)
set_bit(R5_SyncIO, &dev->flags);
if (bio_op(wbi) == REQ_OP_DISCARD)
set_bit(R5_Discard, &dev->flags);
else {
tx = async_copy_data(1, wbi, &dev->page,
dev->offset,
dev->sector, tx, sh,
r5c_is_writeback(conf->log));
if (dev->page != dev->orig_page &&
!r5c_is_writeback(conf->log)) {
set_bit(R5_SkipCopy, &dev->flags);
clear_bit(R5_UPTODATE, &dev->flags);
clear_bit(R5_OVERWRITE, &dev->flags);
}
}
wbi = r5_next_bio(conf, wbi, dev->sector);
}
if (head_sh->batch_head) {
sh = list_first_entry(&sh->batch_list,
struct stripe_head,
batch_list);
if (sh == head_sh)
continue;
goto again;
}
}
}
return tx;
}
static void ops_complete_reconstruct(void *stripe_head_ref)
{
struct stripe_head *sh = stripe_head_ref;
int disks = sh->disks;
int pd_idx = sh->pd_idx;
int qd_idx = sh->qd_idx;
int i;
bool fua = false, sync = false, discard = false;
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
for (i = disks; i--; ) {
fua |= test_bit(R5_WantFUA, &sh->dev[i].flags);
sync |= test_bit(R5_SyncIO, &sh->dev[i].flags);
discard |= test_bit(R5_Discard, &sh->dev[i].flags);
}
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
if (dev->written || i == pd_idx || i == qd_idx) {
if (!discard && !test_bit(R5_SkipCopy, &dev->flags)) {
set_bit(R5_UPTODATE, &dev->flags);
if (test_bit(STRIPE_EXPAND_READY, &sh->state))
set_bit(R5_Expanded, &dev->flags);
}
if (fua)
set_bit(R5_WantFUA, &dev->flags);
if (sync)
set_bit(R5_SyncIO, &dev->flags);
}
}
if (sh->reconstruct_state == reconstruct_state_drain_run)
sh->reconstruct_state = reconstruct_state_drain_result;
else if (sh->reconstruct_state == reconstruct_state_prexor_drain_run)
sh->reconstruct_state = reconstruct_state_prexor_drain_result;
else {
BUG_ON(sh->reconstruct_state != reconstruct_state_run);
sh->reconstruct_state = reconstruct_state_result;
}
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
}
static void
ops_run_reconstruct5(struct stripe_head *sh, struct raid5_percpu *percpu,
struct dma_async_tx_descriptor *tx)
{
int disks = sh->disks;
struct page **xor_srcs;
unsigned int *off_srcs;
struct async_submit_ctl submit;
int count, pd_idx = sh->pd_idx, i;
struct page *xor_dest;
unsigned int off_dest;
int prexor = 0;
unsigned long flags;
int j = 0;
struct stripe_head *head_sh = sh;
int last_stripe;
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
for (i = 0; i < sh->disks; i++) {
if (pd_idx == i)
continue;
if (!test_bit(R5_Discard, &sh->dev[i].flags))
break;
}
if (i >= sh->disks) {
atomic_inc(&sh->count);
set_bit(R5_Discard, &sh->dev[pd_idx].flags);
ops_complete_reconstruct(sh);
return;
}
again:
count = 0;
xor_srcs = to_addr_page(percpu, j);
off_srcs = to_addr_offs(sh, percpu);
/* check if prexor is active which means only process blocks
* that are part of a read-modify-write (written)
*/
if (head_sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
prexor = 1;
off_dest = off_srcs[count] = sh->dev[pd_idx].offset;
xor_dest = xor_srcs[count++] = sh->dev[pd_idx].page;
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
if (head_sh->dev[i].written ||
test_bit(R5_InJournal, &head_sh->dev[i].flags)) {
off_srcs[count] = dev->offset;
xor_srcs[count++] = dev->page;
}
}
} else {
xor_dest = sh->dev[pd_idx].page;
off_dest = sh->dev[pd_idx].offset;
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
if (i != pd_idx) {
off_srcs[count] = dev->offset;
xor_srcs[count++] = dev->page;
}
}
}
/* 1/ if we prexor'd then the dest is reused as a source
* 2/ if we did not prexor then we are redoing the parity
* set ASYNC_TX_XOR_DROP_DST and ASYNC_TX_XOR_ZERO_DST
* for the synchronous xor case
*/
last_stripe = !head_sh->batch_head ||
list_first_entry(&sh->batch_list,
struct stripe_head, batch_list) == head_sh;
if (last_stripe) {
flags = ASYNC_TX_ACK |
(prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST);
atomic_inc(&head_sh->count);
init_async_submit(&submit, flags, tx, ops_complete_reconstruct, head_sh,
to_addr_conv(sh, percpu, j));
} else {
flags = prexor ? ASYNC_TX_XOR_DROP_DST : ASYNC_TX_XOR_ZERO_DST;
init_async_submit(&submit, flags, tx, NULL, NULL,
to_addr_conv(sh, percpu, j));
}
if (unlikely(count == 1))
tx = async_memcpy(xor_dest, xor_srcs[0], off_dest, off_srcs[0],
RAID5_STRIPE_SIZE(sh->raid_conf), &submit);
else
tx = async_xor_offs(xor_dest, off_dest, xor_srcs, off_srcs, count,
RAID5_STRIPE_SIZE(sh->raid_conf), &submit);
if (!last_stripe) {
j++;
sh = list_first_entry(&sh->batch_list, struct stripe_head,
batch_list);
goto again;
}
}
static void
ops_run_reconstruct6(struct stripe_head *sh, struct raid5_percpu *percpu,
struct dma_async_tx_descriptor *tx)
{
struct async_submit_ctl submit;
struct page **blocks;
unsigned int *offs;
int count, i, j = 0;
struct stripe_head *head_sh = sh;
int last_stripe;
int synflags;
unsigned long txflags;
pr_debug("%s: stripe %llu\n", __func__, (unsigned long long)sh->sector);
for (i = 0; i < sh->disks; i++) {
if (sh->pd_idx == i || sh->qd_idx == i)
continue;
if (!test_bit(R5_Discard, &sh->dev[i].flags))
break;
}
if (i >= sh->disks) {
atomic_inc(&sh->count);
set_bit(R5_Discard, &sh->dev[sh->pd_idx].flags);
set_bit(R5_Discard, &sh->dev[sh->qd_idx].flags);
ops_complete_reconstruct(sh);
return;
}
again:
blocks = to_addr_page(percpu, j);
offs = to_addr_offs(sh, percpu);
if (sh->reconstruct_state == reconstruct_state_prexor_drain_run) {
synflags = SYNDROME_SRC_WRITTEN;
txflags = ASYNC_TX_ACK | ASYNC_TX_PQ_XOR_DST;
} else {
synflags = SYNDROME_SRC_ALL;
txflags = ASYNC_TX_ACK;
}
count = set_syndrome_sources(blocks, offs, sh, synflags);
last_stripe = !head_sh->batch_head ||
list_first_entry(&sh->batch_list,
struct stripe_head, batch_list) == head_sh;
if (last_stripe) {
atomic_inc(&head_sh->count);
init_async_submit(&submit, txflags, tx, ops_complete_reconstruct,
head_sh, to_addr_conv(sh, percpu, j));
} else
init_async_submit(&submit, 0, tx, NULL, NULL,
to_addr_conv(sh, percpu, j));
tx = async_gen_syndrome(blocks, offs, count+2,
RAID5_STRIPE_SIZE(sh->raid_conf), &submit);
if (!last_stripe) {
j++;
sh = list_first_entry(&sh->batch_list, struct stripe_head,
batch_list);
goto again;
}
}
static void ops_complete_check(void *stripe_head_ref)
{
struct stripe_head *sh = stripe_head_ref;
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
sh->check_state = check_state_check_result;
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
}
static void ops_run_check_p(struct stripe_head *sh, struct raid5_percpu *percpu)
{
int disks = sh->disks;
int pd_idx = sh->pd_idx;
int qd_idx = sh->qd_idx;
struct page *xor_dest;
unsigned int off_dest;
struct page **xor_srcs = to_addr_page(percpu, 0);
unsigned int *off_srcs = to_addr_offs(sh, percpu);
struct dma_async_tx_descriptor *tx;
struct async_submit_ctl submit;
int count;
int i;
pr_debug("%s: stripe %llu\n", __func__,
(unsigned long long)sh->sector);
BUG_ON(sh->batch_head);
count = 0;
xor_dest = sh->dev[pd_idx].page;
off_dest = sh->dev[pd_idx].offset;
off_srcs[count] = off_dest;
xor_srcs[count++] = xor_dest;
for (i = disks; i--; ) {
if (i == pd_idx || i == qd_idx)
continue;
off_srcs[count] = sh->dev[i].offset;
xor_srcs[count++] = sh->dev[i].page;
}
init_async_submit(&submit, 0, NULL, NULL, NULL,
to_addr_conv(sh, percpu, 0));
tx = async_xor_val_offs(xor_dest, off_dest, xor_srcs, off_srcs, count,
RAID5_STRIPE_SIZE(sh->raid_conf),
&sh->ops.zero_sum_result, &submit);
atomic_inc(&sh->count);
init_async_submit(&submit, ASYNC_TX_ACK, tx, ops_complete_check, sh, NULL);
tx = async_trigger_callback(&submit);
}
static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu, int checkp)
{
struct page **srcs = to_addr_page(percpu, 0);
unsigned int *offs = to_addr_offs(sh, percpu);
struct async_submit_ctl submit;
int count;
pr_debug("%s: stripe %llu checkp: %d\n", __func__,
(unsigned long long)sh->sector, checkp);
BUG_ON(sh->batch_head);
count = set_syndrome_sources(srcs, offs, sh, SYNDROME_SRC_ALL);
if (!checkp)
srcs[count] = NULL;
atomic_inc(&sh->count);
init_async_submit(&submit, ASYNC_TX_ACK, NULL, ops_complete_check,
sh, to_addr_conv(sh, percpu, 0));
async_syndrome_val(srcs, offs, count+2,
RAID5_STRIPE_SIZE(sh->raid_conf),
&sh->ops.zero_sum_result, percpu->spare_page, 0, &submit);
}
static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
{
int overlap_clear = 0, i, disks = sh->disks;
struct dma_async_tx_descriptor *tx = NULL;
struct r5conf *conf = sh->raid_conf;
int level = conf->level;
struct raid5_percpu *percpu;
local_lock(&conf->percpu->lock);
percpu = this_cpu_ptr(conf->percpu);
if (test_bit(STRIPE_OP_BIOFILL, &ops_request)) {
ops_run_biofill(sh);
overlap_clear++;
}
if (test_bit(STRIPE_OP_COMPUTE_BLK, &ops_request)) {
if (level < 6)
tx = ops_run_compute5(sh, percpu);
else {
if (sh->ops.target2 < 0 || sh->ops.target < 0)
tx = ops_run_compute6_1(sh, percpu);
else
tx = ops_run_compute6_2(sh, percpu);
}
/* terminate the chain if reconstruct is not set to be run */
if (tx && !test_bit(STRIPE_OP_RECONSTRUCT, &ops_request))
async_tx_ack(tx);
}
if (test_bit(STRIPE_OP_PREXOR, &ops_request)) {
if (level < 6)
tx = ops_run_prexor5(sh, percpu, tx);
else
tx = ops_run_prexor6(sh, percpu, tx);
}
if (test_bit(STRIPE_OP_PARTIAL_PARITY, &ops_request))
tx = ops_run_partial_parity(sh, percpu, tx);
if (test_bit(STRIPE_OP_BIODRAIN, &ops_request)) {
tx = ops_run_biodrain(sh, tx);
overlap_clear++;
}
if (test_bit(STRIPE_OP_RECONSTRUCT, &ops_request)) {
if (level < 6)
ops_run_reconstruct5(sh, percpu, tx);
else
ops_run_reconstruct6(sh, percpu, tx);
}
if (test_bit(STRIPE_OP_CHECK, &ops_request)) {
if (sh->check_state == check_state_run)
ops_run_check_p(sh, percpu);
else if (sh->check_state == check_state_run_q)
ops_run_check_pq(sh, percpu, 0);
else if (sh->check_state == check_state_run_pq)
ops_run_check_pq(sh, percpu, 1);
else
BUG();
}
if (overlap_clear && !sh->batch_head) {
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
if (test_and_clear_bit(R5_Overlap, &dev->flags))
wake_up(&sh->raid_conf->wait_for_overlap);
}
}
local_unlock(&conf->percpu->lock);
}
static void free_stripe(struct kmem_cache *sc, struct stripe_head *sh)
{
#if PAGE_SIZE != DEFAULT_STRIPE_SIZE
kfree(sh->pages);
#endif
if (sh->ppl_page)
__free_page(sh->ppl_page);
kmem_cache_free(sc, sh);
}
static struct stripe_head *alloc_stripe(struct kmem_cache *sc, gfp_t gfp,
int disks, struct r5conf *conf)
{
struct stripe_head *sh;
sh = kmem_cache_zalloc(sc, gfp);
if (sh) {
spin_lock_init(&sh->stripe_lock);
spin_lock_init(&sh->batch_lock);
INIT_LIST_HEAD(&sh->batch_list);
INIT_LIST_HEAD(&sh->lru);
INIT_LIST_HEAD(&sh->r5c);
INIT_LIST_HEAD(&sh->log_list);
atomic_set(&sh->count, 1);
sh->raid_conf = conf;
sh->log_start = MaxSector;
if (raid5_has_ppl(conf)) {
sh->ppl_page = alloc_page(gfp);
if (!sh->ppl_page) {
free_stripe(sc, sh);
return NULL;
}
}
#if PAGE_SIZE != DEFAULT_STRIPE_SIZE
if (init_stripe_shared_pages(sh, conf, disks)) {
free_stripe(sc, sh);
return NULL;
}
#endif
}
return sh;
}
static int grow_one_stripe(struct r5conf *conf, gfp_t gfp)
{
struct stripe_head *sh;
sh = alloc_stripe(conf->slab_cache, gfp, conf->pool_size, conf);
if (!sh)
return 0;
if (grow_buffers(sh, gfp)) {
shrink_buffers(sh);
free_stripe(conf->slab_cache, sh);
return 0;
}
sh->hash_lock_index =
conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS;
/* we just created an active stripe so... */
atomic_inc(&conf->active_stripes);
raid5_release_stripe(sh);
conf->max_nr_stripes++;
return 1;
}
static int grow_stripes(struct r5conf *conf, int num)
{
struct kmem_cache *sc;
size_t namelen = sizeof(conf->cache_name[0]);
int devs = max(conf->raid_disks, conf->previous_raid_disks);
if (conf->mddev->gendisk)
snprintf(conf->cache_name[0], namelen,
"raid%d-%s", conf->level, mdname(conf->mddev));
else
snprintf(conf->cache_name[0], namelen,
"raid%d-%p", conf->level, conf->mddev);
snprintf(conf->cache_name[1], namelen, "%.27s-alt", conf->cache_name[0]);
conf->active_name = 0;
sc = kmem_cache_create(conf->cache_name[conf->active_name],
struct_size_t(struct stripe_head, dev, devs),
0, 0, NULL);
if (!sc)
return 1;
conf->slab_cache = sc;
conf->pool_size = devs;
while (num--)
if (!grow_one_stripe(conf, GFP_KERNEL))
return 1;
return 0;
}
/**
* scribble_alloc - allocate percpu scribble buffer for required size
* of the scribble region
* @percpu: from for_each_present_cpu() of the caller
* @num: total number of disks in the array
* @cnt: scribble objs count for required size of the scribble region
*
* The scribble buffer size must be enough to contain:
* 1/ a struct page pointer for each device in the array +2
* 2/ room to convert each entry in (1) to its corresponding dma
* (dma_map_page()) or page (page_address()) address.
*
* Note: the +2 is for the destination buffers of the ddf/raid6 case where we
* calculate over all devices (not just the data blocks), using zeros in place
* of the P and Q blocks.
*/
static int scribble_alloc(struct raid5_percpu *percpu,
int num, int cnt)
{
size_t obj_size =
sizeof(struct page *) * (num + 2) +
sizeof(addr_conv_t) * (num + 2) +
sizeof(unsigned int) * (num + 2);
void *scribble;
/*
* If here is in raid array suspend context, it is in memalloc noio
* context as well, there is no potential recursive memory reclaim
* I/Os with the GFP_KERNEL flag.
*/
scribble = kvmalloc_array(cnt, obj_size, GFP_KERNEL);
if (!scribble)
return -ENOMEM;
kvfree(percpu->scribble);
percpu->scribble = scribble;
percpu->scribble_obj_size = obj_size;
return 0;
}
static int resize_chunks(struct r5conf *conf, int new_disks, int new_sectors)
{
unsigned long cpu;
int err = 0;
/*
* Never shrink. And mddev_suspend() could deadlock if this is called
* from raid5d. In that case, scribble_disks and scribble_sectors
* should equal to new_disks and new_sectors
*/
if (conf->scribble_disks >= new_disks &&
conf->scribble_sectors >= new_sectors)
return 0;
mddev_suspend(conf->mddev);
cpus_read_lock();
for_each_present_cpu(cpu) {
struct raid5_percpu *percpu;
percpu = per_cpu_ptr(conf->percpu, cpu);
err = scribble_alloc(percpu, new_disks,
new_sectors / RAID5_STRIPE_SECTORS(conf));
if (err)
break;
}
cpus_read_unlock();
mddev_resume(conf->mddev);
if (!err) {
conf->scribble_disks = new_disks;
conf->scribble_sectors = new_sectors;
}
return err;
}
static int resize_stripes(struct r5conf *conf, int newsize)
{
/* Make all the stripes able to hold 'newsize' devices.
* New slots in each stripe get 'page' set to a new page.
*
* This happens in stages:
* 1/ create a new kmem_cache and allocate the required number of
* stripe_heads.
* 2/ gather all the old stripe_heads and transfer the pages across
* to the new stripe_heads. This will have the side effect of
* freezing the array as once all stripe_heads have been collected,
* no IO will be possible. Old stripe heads are freed once their
* pages have been transferred over, and the old kmem_cache is
* freed when all stripes are done.
* 3/ reallocate conf->disks to be suitable bigger. If this fails,
* we simple return a failure status - no need to clean anything up.
* 4/ allocate new pages for the new slots in the new stripe_heads.
* If this fails, we don't bother trying the shrink the
* stripe_heads down again, we just leave them as they are.
* As each stripe_head is processed the new one is released into
* active service.
*
* Once step2 is started, we cannot afford to wait for a write,
* so we use GFP_NOIO allocations.
*/
struct stripe_head *osh, *nsh;
LIST_HEAD(newstripes);
struct disk_info *ndisks;
int err = 0;
struct kmem_cache *sc;
int i;
int hash, cnt;
md_allow_write(conf->mddev);
/* Step 1 */
sc = kmem_cache_create(conf->cache_name[1-conf->active_name],
struct_size_t(struct stripe_head, dev, newsize),
0, 0, NULL);
if (!sc)
return -ENOMEM;
/* Need to ensure auto-resizing doesn't interfere */
mutex_lock(&conf->cache_size_mutex);
for (i = conf->max_nr_stripes; i; i--) {
nsh = alloc_stripe(sc, GFP_KERNEL, newsize, conf);
if (!nsh)
break;
list_add(&nsh->lru, &newstripes);
}
if (i) {
/* didn't get enough, give up */
while (!list_empty(&newstripes)) {
nsh = list_entry(newstripes.next, struct stripe_head, lru);
list_del(&nsh->lru);
free_stripe(sc, nsh);
}
kmem_cache_destroy(sc);
mutex_unlock(&conf->cache_size_mutex);
return -ENOMEM;
}
/* Step 2 - Must use GFP_NOIO now.
* OK, we have enough stripes, start collecting inactive
* stripes and copying them over
*/
hash = 0;
cnt = 0;
list_for_each_entry(nsh, &newstripes, lru) {
lock_device_hash_lock(conf, hash);
wait_event_cmd(conf->wait_for_stripe,
!list_empty(conf->inactive_list + hash),
unlock_device_hash_lock(conf, hash),
lock_device_hash_lock(conf, hash));
osh = get_free_stripe(conf, hash);
unlock_device_hash_lock(conf, hash);
#if PAGE_SIZE != DEFAULT_STRIPE_SIZE
for (i = 0; i < osh->nr_pages; i++) {
nsh->pages[i] = osh->pages[i];
osh->pages[i] = NULL;
}
#endif
for(i=0; i<conf->pool_size; i++) {
nsh->dev[i].page = osh->dev[i].page;
nsh->dev[i].orig_page = osh->dev[i].page;
nsh->dev[i].offset = osh->dev[i].offset;
}
nsh->hash_lock_index = hash;
free_stripe(conf->slab_cache, osh);
cnt++;
if (cnt >= conf->max_nr_stripes / NR_STRIPE_HASH_LOCKS +
!!((conf->max_nr_stripes % NR_STRIPE_HASH_LOCKS) > hash)) {
hash++;
cnt = 0;
}
}
kmem_cache_destroy(conf->slab_cache);
/* Step 3.
* At this point, we are holding all the stripes so the array
* is completely stalled, so now is a good time to resize
* conf->disks and the scribble region
*/
ndisks = kcalloc(newsize, sizeof(struct disk_info), GFP_NOIO);
if (ndisks) {
for (i = 0; i < conf->pool_size; i++)
ndisks[i] = conf->disks[i];
for (i = conf->pool_size; i < newsize; i++) {
ndisks[i].extra_page = alloc_page(GFP_NOIO);
if (!ndisks[i].extra_page)
err = -ENOMEM;
}
if (err) {
for (i = conf->pool_size; i < newsize; i++)
if (ndisks[i].extra_page)
put_page(ndisks[i].extra_page);
kfree(ndisks);
} else {
kfree(conf->disks);
conf->disks = ndisks;
}
} else
err = -ENOMEM;
conf->slab_cache = sc;
conf->active_name = 1-conf->active_name;
/* Step 4, return new stripes to service */
while(!list_empty(&newstripes)) {
nsh = list_entry(newstripes.next, struct stripe_head, lru);
list_del_init(&nsh->lru);
#if PAGE_SIZE != DEFAULT_STRIPE_SIZE
for (i = 0; i < nsh->nr_pages; i++) {
if (nsh->pages[i])
continue;
nsh->pages[i] = alloc_page(GFP_NOIO);
if (!nsh->pages[i])
err = -ENOMEM;
}
for (i = conf->raid_disks; i < newsize; i++) {
if (nsh->dev[i].page)
continue;
nsh->dev[i].page = raid5_get_dev_page(nsh, i);
nsh->dev[i].orig_page = nsh->dev[i].page;
nsh->dev[i].offset = raid5_get_page_offset(nsh, i);
}
#else
for (i=conf->raid_disks; i < newsize; i++)
if (nsh->dev[i].page == NULL) {
struct page *p = alloc_page(GFP_NOIO);
nsh->dev[i].page = p;
nsh->dev[i].orig_page = p;
nsh->dev[i].offset = 0;
if (!p)
err = -ENOMEM;
}
#endif
raid5_release_stripe(nsh);
}
/* critical section pass, GFP_NOIO no longer needed */
if (!err)
conf->pool_size = newsize;
mutex_unlock(&conf->cache_size_mutex);
return err;
}
static int drop_one_stripe(struct r5conf *conf)
{
struct stripe_head *sh;
int hash = (conf->max_nr_stripes - 1) & STRIPE_HASH_LOCKS_MASK;
spin_lock_irq(conf->hash_locks + hash);
sh = get_free_stripe(conf, hash);
spin_unlock_irq(conf->hash_locks + hash);
if (!sh)
return 0;
BUG_ON(atomic_read(&sh->count));
shrink_buffers(sh);
free_stripe(conf->slab_cache, sh);
atomic_dec(&conf->active_stripes);
conf->max_nr_stripes--;
return 1;
}
static void shrink_stripes(struct r5conf *conf)
{
while (conf->max_nr_stripes &&
drop_one_stripe(conf))
;
kmem_cache_destroy(conf->slab_cache);
conf->slab_cache = NULL;
}
/*
* This helper wraps rcu_dereference_protected() and can be used when
* it is known that the nr_pending of the rdev is elevated.
*/
static struct md_rdev *rdev_pend_deref(struct md_rdev __rcu *rdev)
{
return rcu_dereference_protected(rdev,
atomic_read(&rcu_access_pointer(rdev)->nr_pending));
}
/*
* This helper wraps rcu_dereference_protected() and should be used
* when it is known that the mddev_lock() is held. This is safe
* seeing raid5_remove_disk() has the same lock held.
*/
static struct md_rdev *rdev_mdlock_deref(struct mddev *mddev,
struct md_rdev __rcu *rdev)
{
return rcu_dereference_protected(rdev,
lockdep_is_held(&mddev->reconfig_mutex));
}
static void raid5_end_read_request(struct bio * bi)
{
struct stripe_head *sh = bi->bi_private;
struct r5conf *conf = sh->raid_conf;
int disks = sh->disks, i;
struct md_rdev *rdev = NULL;
sector_t s;
for (i=0 ; i<disks; i++)
if (bi == &sh->dev[i].req)
break;
pr_debug("end_read_request %llu/%d, count: %d, error %d.\n",
(unsigned long long)sh->sector, i, atomic_read(&sh->count),
bi->bi_status);
if (i == disks) {
BUG();
return;
}
if (test_bit(R5_ReadRepl, &sh->dev[i].flags))
/* If replacement finished while this request was outstanding,
* 'replacement' might be NULL already.
* In that case it moved down to 'rdev'.
* rdev is not removed until all requests are finished.
*/
rdev = rdev_pend_deref(conf->disks[i].replacement);
if (!rdev)
rdev = rdev_pend_deref(conf->disks[i].rdev);
if (use_new_offset(conf, sh))
s = sh->sector + rdev->new_data_offset;
else
s = sh->sector + rdev->data_offset;
if (!bi->bi_status) {
set_bit(R5_UPTODATE, &sh->dev[i].flags);
if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
/* Note that this cannot happen on a
* replacement device. We just fail those on
* any error
*/
pr_info_ratelimited(
"md/raid:%s: read error corrected (%lu sectors at %llu on %pg)\n",
mdname(conf->mddev), RAID5_STRIPE_SECTORS(conf),
(unsigned long long)s,
rdev->bdev);
atomic_add(RAID5_STRIPE_SECTORS(conf), &rdev->corrected_errors);
clear_bit(R5_ReadError, &sh->dev[i].flags);
clear_bit(R5_ReWrite, &sh->dev[i].flags);
} else if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
clear_bit(R5_ReadNoMerge, &sh->dev[i].flags);
if (test_bit(R5_InJournal, &sh->dev[i].flags))
/*
* end read for a page in journal, this
* must be preparing for prexor in rmw
*/
set_bit(R5_OrigPageUPTDODATE, &sh->dev[i].flags);
if (atomic_read(&rdev->read_errors))
atomic_set(&rdev->read_errors, 0);
} else {
int retry = 0;
int set_bad = 0;
clear_bit(R5_UPTODATE, &sh->dev[i].flags);
if (!(bi->bi_status == BLK_STS_PROTECTION))
atomic_inc(&rdev->read_errors);
if (test_bit(R5_ReadRepl, &sh->dev[i].flags))
pr_warn_ratelimited(
"md/raid:%s: read error on replacement device (sector %llu on %pg).\n",
mdname(conf->mddev),
(unsigned long long)s,
rdev->bdev);
else if (conf->mddev->degraded >= conf->max_degraded) {
set_bad = 1;
pr_warn_ratelimited(
"md/raid:%s: read error not correctable (sector %llu on %pg).\n",
mdname(conf->mddev),
(unsigned long long)s,
rdev->bdev);
} else if (test_bit(R5_ReWrite, &sh->dev[i].flags)) {
/* Oh, no!!! */
set_bad = 1;
pr_warn_ratelimited(
"md/raid:%s: read error NOT corrected!! (sector %llu on %pg).\n",
mdname(conf->mddev),
(unsigned long long)s,
rdev->bdev);
} else if (atomic_read(&rdev->read_errors)
> conf->max_nr_stripes) {
if (!test_bit(Faulty, &rdev->flags)) {
pr_warn("md/raid:%s: %d read_errors > %d stripes\n",
mdname(conf->mddev),
atomic_read(&rdev->read_errors),
conf->max_nr_stripes);
pr_warn("md/raid:%s: Too many read errors, failing device %pg.\n",
mdname(conf->mddev), rdev->bdev);
}
} else
retry = 1;
if (set_bad && test_bit(In_sync, &rdev->flags)
&& !test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
retry = 1;
if (retry)
if (sh->qd_idx >= 0 && sh->pd_idx == i)
set_bit(R5_ReadError, &sh->dev[i].flags);
else if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags)) {
set_bit(R5_ReadError, &sh->dev[i].flags);
clear_bit(R5_ReadNoMerge, &sh->dev[i].flags);
} else
set_bit(R5_ReadNoMerge, &sh->dev[i].flags);
else {
clear_bit(R5_ReadError, &sh->dev[i].flags);
clear_bit(R5_ReWrite, &sh->dev[i].flags);
if (!(set_bad
&& test_bit(In_sync, &rdev->flags)
&& rdev_set_badblocks(
rdev, sh->sector, RAID5_STRIPE_SECTORS(conf), 0)))
md_error(conf->mddev, rdev);
}
}
rdev_dec_pending(rdev, conf->mddev);
bio_uninit(bi);
clear_bit(R5_LOCKED, &sh->dev[i].flags);
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
}
static void raid5_end_write_request(struct bio *bi)
{
struct stripe_head *sh = bi->bi_private;
struct r5conf *conf = sh->raid_conf;
int disks = sh->disks, i;
struct md_rdev *rdev;
sector_t first_bad;
int bad_sectors;
int replacement = 0;
for (i = 0 ; i < disks; i++) {
if (bi == &sh->dev[i].req) {
rdev = rdev_pend_deref(conf->disks[i].rdev);
break;
}
if (bi == &sh->dev[i].rreq) {
rdev = rdev_pend_deref(conf->disks[i].replacement);
if (rdev)
replacement = 1;
else
/* rdev was removed and 'replacement'
* replaced it. rdev is not removed
* until all requests are finished.
*/
rdev = rdev_pend_deref(conf->disks[i].rdev);
break;
}
}
pr_debug("end_write_request %llu/%d, count %d, error: %d.\n",
(unsigned long long)sh->sector, i, atomic_read(&sh->count),
bi->bi_status);
if (i == disks) {
BUG();
return;
}
if (replacement) {
if (bi->bi_status)
md_error(conf->mddev, rdev);
else if (is_badblock(rdev, sh->sector,
RAID5_STRIPE_SECTORS(conf),
&first_bad, &bad_sectors))
set_bit(R5_MadeGoodRepl, &sh->dev[i].flags);
} else {
if (bi->bi_status) {
set_bit(STRIPE_DEGRADED, &sh->state);
set_bit(WriteErrorSeen, &rdev->flags);
set_bit(R5_WriteError, &sh->dev[i].flags);
if (!test_and_set_bit(WantReplacement, &rdev->flags))
set_bit(MD_RECOVERY_NEEDED,
&rdev->mddev->recovery);
} else if (is_badblock(rdev, sh->sector,
RAID5_STRIPE_SECTORS(conf),
&first_bad, &bad_sectors)) {
set_bit(R5_MadeGood, &sh->dev[i].flags);
if (test_bit(R5_ReadError, &sh->dev[i].flags))
/* That was a successful write so make
* sure it looks like we already did
* a re-write.
*/
set_bit(R5_ReWrite, &sh->dev[i].flags);
}
}
rdev_dec_pending(rdev, conf->mddev);
if (sh->batch_head && bi->bi_status && !replacement)
set_bit(STRIPE_BATCH_ERR, &sh->batch_head->state);
bio_uninit(bi);
if (!test_and_clear_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags))
clear_bit(R5_LOCKED, &sh->dev[i].flags);
set_bit(STRIPE_HANDLE, &sh->state);
if (sh->batch_head && sh != sh->batch_head)
raid5_release_stripe(sh->batch_head);
raid5_release_stripe(sh);
}
static void raid5_error(struct mddev *mddev, struct md_rdev *rdev)
{
struct r5conf *conf = mddev->private;
unsigned long flags;
pr_debug("raid456: error called\n");
pr_crit("md/raid:%s: Disk failure on %pg, disabling device.\n",
mdname(mddev), rdev->bdev);
spin_lock_irqsave(&conf->device_lock, flags);
set_bit(Faulty, &rdev->flags);
clear_bit(In_sync, &rdev->flags);
mddev->degraded = raid5_calc_degraded(conf);
if (has_failed(conf)) {
set_bit(MD_BROKEN, &conf->mddev->flags);
conf->recovery_disabled = mddev->recovery_disabled;
pr_crit("md/raid:%s: Cannot continue operation (%d/%d failed).\n",
mdname(mddev), mddev->degraded, conf->raid_disks);
} else {
pr_crit("md/raid:%s: Operation continuing on %d devices.\n",
mdname(mddev), conf->raid_disks - mddev->degraded);
}
spin_unlock_irqrestore(&conf->device_lock, flags);
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
set_bit(Blocked, &rdev->flags);
set_mask_bits(&mddev->sb_flags, 0,
BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
r5c_update_on_rdev_error(mddev, rdev);
}
/*
* Input: a 'big' sector number,
* Output: index of the data and parity disk, and the sector # in them.
*/
sector_t raid5_compute_sector(struct r5conf *conf, sector_t r_sector,
int previous, int *dd_idx,
struct stripe_head *sh)
{
sector_t stripe, stripe2;
sector_t chunk_number;
unsigned int chunk_offset;
int pd_idx, qd_idx;
int ddf_layout = 0;
sector_t new_sector;
int algorithm = previous ? conf->prev_algo
: conf->algorithm;
int sectors_per_chunk = previous ? conf->prev_chunk_sectors
: conf->chunk_sectors;
int raid_disks = previous ? conf->previous_raid_disks
: conf->raid_disks;
int data_disks = raid_disks - conf->max_degraded;
/* First compute the information on this sector */
/*
* Compute the chunk number and the sector offset inside the chunk
*/
chunk_offset = sector_div(r_sector, sectors_per_chunk);
chunk_number = r_sector;
/*
* Compute the stripe number
*/
stripe = chunk_number;
*dd_idx = sector_div(stripe, data_disks);
stripe2 = stripe;
/*
* Select the parity disk based on the user selected algorithm.
*/
pd_idx = qd_idx = -1;
switch(conf->level) {
case 4:
pd_idx = data_disks;
break;
case 5:
switch (algorithm) {
case ALGORITHM_LEFT_ASYMMETRIC:
pd_idx = data_disks - sector_div(stripe2, raid_disks);
if (*dd_idx >= pd_idx)
(*dd_idx)++;
break;
case ALGORITHM_RIGHT_ASYMMETRIC:
pd_idx = sector_div(stripe2, raid_disks);
if (*dd_idx >= pd_idx)
(*dd_idx)++;
break;
case ALGORITHM_LEFT_SYMMETRIC:
pd_idx = data_disks - sector_div(stripe2, raid_disks);
*dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
break;
case ALGORITHM_RIGHT_SYMMETRIC:
pd_idx = sector_div(stripe2, raid_disks);
*dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
break;
case ALGORITHM_PARITY_0:
pd_idx = 0;
(*dd_idx)++;
break;
case ALGORITHM_PARITY_N:
pd_idx = data_disks;
break;
default:
BUG();
}
break;
case 6:
switch (algorithm) {
case ALGORITHM_LEFT_ASYMMETRIC:
pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
qd_idx = pd_idx + 1;
if (pd_idx == raid_disks-1) {
(*dd_idx)++; /* Q D D D P */
qd_idx = 0;
} else if (*dd_idx >= pd_idx)
(*dd_idx) += 2; /* D D P Q D */
break;
case ALGORITHM_RIGHT_ASYMMETRIC:
pd_idx = sector_div(stripe2, raid_disks);
qd_idx = pd_idx + 1;
if (pd_idx == raid_disks-1) {
(*dd_idx)++; /* Q D D D P */
qd_idx = 0;
} else if (*dd_idx >= pd_idx)
(*dd_idx) += 2; /* D D P Q D */
break;
case ALGORITHM_LEFT_SYMMETRIC:
pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
qd_idx = (pd_idx + 1) % raid_disks;
*dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
break;
case ALGORITHM_RIGHT_SYMMETRIC:
pd_idx = sector_div(stripe2, raid_disks);
qd_idx = (pd_idx + 1) % raid_disks;
*dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks;
break;
case ALGORITHM_PARITY_0:
pd_idx = 0;
qd_idx = 1;
(*dd_idx) += 2;
break;
case ALGORITHM_PARITY_N:
pd_idx = data_disks;
qd_idx = data_disks + 1;
break;
case ALGORITHM_ROTATING_ZERO_RESTART:
/* Exactly the same as RIGHT_ASYMMETRIC, but or
* of blocks for computing Q is different.
*/
pd_idx = sector_div(stripe2, raid_disks);
qd_idx = pd_idx + 1;
if (pd_idx == raid_disks-1) {
(*dd_idx)++; /* Q D D D P */
qd_idx = 0;
} else if (*dd_idx >= pd_idx)
(*dd_idx) += 2; /* D D P Q D */
ddf_layout = 1;
break;
case ALGORITHM_ROTATING_N_RESTART:
/* Same a left_asymmetric, by first stripe is
* D D D P Q rather than
* Q D D D P
*/
stripe2 += 1;
pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
qd_idx = pd_idx + 1;
if (pd_idx == raid_disks-1) {
(*dd_idx)++; /* Q D D D P */
qd_idx = 0;
} else if (*dd_idx >= pd_idx)
(*dd_idx) += 2; /* D D P Q D */
ddf_layout = 1;
break;
case ALGORITHM_ROTATING_N_CONTINUE:
/* Same as left_symmetric but Q is before P */
pd_idx = raid_disks - 1 - sector_div(stripe2, raid_disks);
qd_idx = (pd_idx + raid_disks - 1) % raid_disks;
*dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks;
ddf_layout = 1;
break;
case ALGORITHM_LEFT_ASYMMETRIC_6:
/* RAID5 left_asymmetric, with Q on last device */
pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
if (*dd_idx >= pd_idx)
(*dd_idx)++;
qd_idx = raid_disks - 1;
break;
case ALGORITHM_RIGHT_ASYMMETRIC_6:
pd_idx = sector_div(stripe2, raid_disks-1);
if (*dd_idx >= pd_idx)
(*dd_idx)++;
qd_idx = raid_disks - 1;
break;
case ALGORITHM_LEFT_SYMMETRIC_6:
pd_idx = data_disks - sector_div(stripe2, raid_disks-1);
*dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
qd_idx = raid_disks - 1;
break;
case ALGORITHM_RIGHT_SYMMETRIC_6:
pd_idx = sector_div(stripe2, raid_disks-1);
*dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1);
qd_idx = raid_disks - 1;
break;
case ALGORITHM_PARITY_0_6:
pd_idx = 0;
(*dd_idx)++;
qd_idx = raid_disks - 1;
break;
default:
BUG();
}
break;
}
if (sh) {
sh->pd_idx = pd_idx;
sh->qd_idx = qd_idx;
sh->ddf_layout = ddf_layout;
}
/*
* Finally, compute the new sector number
*/
new_sector = (sector_t)stripe * sectors_per_chunk + chunk_offset;
return new_sector;
}
sector_t raid5_compute_blocknr(struct stripe_head *sh, int i, int previous)
{
struct r5conf *conf = sh->raid_conf;
int raid_disks = sh->disks;
int data_disks = raid_disks - conf->max_degraded;
sector_t new_sector = sh->sector, check;
int sectors_per_chunk = previous ? conf->prev_chunk_sectors
: conf->chunk_sectors;
int algorithm = previous ? conf->prev_algo
: conf->algorithm;
sector_t stripe;
int chunk_offset;
sector_t chunk_number;
int dummy1, dd_idx = i;
sector_t r_sector;
struct stripe_head sh2;
chunk_offset = sector_div(new_sector, sectors_per_chunk);
stripe = new_sector;
if (i == sh->pd_idx)
return 0;
switch(conf->level) {
case 4: break;
case 5:
switch (algorithm) {
case ALGORITHM_LEFT_ASYMMETRIC:
case ALGORITHM_RIGHT_ASYMMETRIC:
if (i > sh->pd_idx)
i--;
break;
case ALGORITHM_LEFT_SYMMETRIC:
case ALGORITHM_RIGHT_SYMMETRIC:
if (i < sh->pd_idx)
i += raid_disks;
i -= (sh->pd_idx + 1);
break;
case ALGORITHM_PARITY_0:
i -= 1;
break;
case ALGORITHM_PARITY_N:
break;
default:
BUG();
}
break;
case 6:
if (i == sh->qd_idx)
return 0; /* It is the Q disk */
switch (algorithm) {
case ALGORITHM_LEFT_ASYMMETRIC:
case ALGORITHM_RIGHT_ASYMMETRIC:
case ALGORITHM_ROTATING_ZERO_RESTART:
case ALGORITHM_ROTATING_N_RESTART:
if (sh->pd_idx == raid_disks-1)
i--; /* Q D D D P */
else if (i > sh->pd_idx)
i -= 2; /* D D P Q D */
break;
case ALGORITHM_LEFT_SYMMETRIC:
case ALGORITHM_RIGHT_SYMMETRIC:
if (sh->pd_idx == raid_disks-1)
i--; /* Q D D D P */
else {
/* D D P Q D */
if (i < sh->pd_idx)
i += raid_disks;
i -= (sh->pd_idx + 2);
}
break;
case ALGORITHM_PARITY_0:
i -= 2;
break;
case ALGORITHM_PARITY_N:
break;
case ALGORITHM_ROTATING_N_CONTINUE:
/* Like left_symmetric, but P is before Q */
if (sh->pd_idx == 0)
i--; /* P D D D Q */
else {
/* D D Q P D */
if (i < sh->pd_idx)
i += raid_disks;
i -= (sh->pd_idx + 1);
}
break;
case ALGORITHM_LEFT_ASYMMETRIC_6:
case ALGORITHM_RIGHT_ASYMMETRIC_6:
if (i > sh->pd_idx)
i--;
break;
case ALGORITHM_LEFT_SYMMETRIC_6:
case ALGORITHM_RIGHT_SYMMETRIC_6:
if (i < sh->pd_idx)
i += data_disks + 1;
i -= (sh->pd_idx + 1);
break;
case ALGORITHM_PARITY_0_6:
i -= 1;
break;
default:
BUG();
}
break;
}
chunk_number = stripe * data_disks + i;
r_sector = chunk_number * sectors_per_chunk + chunk_offset;
check = raid5_compute_sector(conf, r_sector,
previous, &dummy1, &sh2);
if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx
|| sh2.qd_idx != sh->qd_idx) {
pr_warn("md/raid:%s: compute_blocknr: map not correct\n",
mdname(conf->mddev));
return 0;
}
return r_sector;
}
/*
* There are cases where we want handle_stripe_dirtying() and
* schedule_reconstruction() to delay towrite to some dev of a stripe.
*
* This function checks whether we want to delay the towrite. Specifically,
* we delay the towrite when:
*
* 1. degraded stripe has a non-overwrite to the missing dev, AND this
* stripe has data in journal (for other devices).
*
* In this case, when reading data for the non-overwrite dev, it is
* necessary to handle complex rmw of write back cache (prexor with
* orig_page, and xor with page). To keep read path simple, we would
* like to flush data in journal to RAID disks first, so complex rmw
* is handled in the write patch (handle_stripe_dirtying).
*
* 2. when journal space is critical (R5C_LOG_CRITICAL=1)
*
* It is important to be able to flush all stripes in raid5-cache.
* Therefore, we need reserve some space on the journal device for
* these flushes. If flush operation includes pending writes to the
* stripe, we need to reserve (conf->raid_disk + 1) pages per stripe
* for the flush out. If we exclude these pending writes from flush
* operation, we only need (conf->max_degraded + 1) pages per stripe.
* Therefore, excluding pending writes in these cases enables more
* efficient use of the journal device.
*
* Note: To make sure the stripe makes progress, we only delay
* towrite for stripes with data already in journal (injournal > 0).
* When LOG_CRITICAL, stripes with injournal == 0 will be sent to
* no_space_stripes list.
*
* 3. during journal failure
* In journal failure, we try to flush all cached data to raid disks
* based on data in stripe cache. The array is read-only to upper
* layers, so we would skip all pending writes.
*
*/
static inline bool delay_towrite(struct r5conf *conf,
struct r5dev *dev,
struct stripe_head_state *s)
{
/* case 1 above */
if (!test_bit(R5_OVERWRITE, &dev->flags) &&
!test_bit(R5_Insync, &dev->flags) && s->injournal)
return true;
/* case 2 above */
if (test_bit(R5C_LOG_CRITICAL, &conf->cache_state) &&
s->injournal > 0)
return true;
/* case 3 above */
if (s->log_failed && s->injournal)
return true;
return false;
}
static void
schedule_reconstruction(struct stripe_head *sh, struct stripe_head_state *s,
int rcw, int expand)
{
int i, pd_idx = sh->pd_idx, qd_idx = sh->qd_idx, disks = sh->disks;
struct r5conf *conf = sh->raid_conf;
int level = conf->level;
if (rcw) {
/*
* In some cases, handle_stripe_dirtying initially decided to
* run rmw and allocates extra page for prexor. However, rcw is
* cheaper later on. We need to free the extra page now,
* because we won't be able to do that in ops_complete_prexor().
*/
r5c_release_extra_page(sh);
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
if (dev->towrite && !delay_towrite(conf, dev, s)) {
set_bit(R5_LOCKED, &dev->flags);
set_bit(R5_Wantdrain, &dev->flags);
if (!expand)
clear_bit(R5_UPTODATE, &dev->flags);
s->locked++;
} else if (test_bit(R5_InJournal, &dev->flags)) {
set_bit(R5_LOCKED, &dev->flags);
s->locked++;
}
}
/* if we are not expanding this is a proper write request, and
* there will be bios with new data to be drained into the
* stripe cache
*/
if (!expand) {
if (!s->locked)
/* False alarm, nothing to do */
return;
sh->reconstruct_state = reconstruct_state_drain_run;
set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
} else
sh->reconstruct_state = reconstruct_state_run;
set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
if (s->locked + conf->max_degraded == disks)
if (!test_and_set_bit(STRIPE_FULL_WRITE, &sh->state))
atomic_inc(&conf->pending_full_writes);
} else {
BUG_ON(!(test_bit(R5_UPTODATE, &sh->dev[pd_idx].flags) ||
test_bit(R5_Wantcompute, &sh->dev[pd_idx].flags)));
BUG_ON(level == 6 &&
(!(test_bit(R5_UPTODATE, &sh->dev[qd_idx].flags) ||
test_bit(R5_Wantcompute, &sh->dev[qd_idx].flags))));
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
if (i == pd_idx || i == qd_idx)
continue;
if (dev->towrite &&
(test_bit(R5_UPTODATE, &dev->flags) ||
test_bit(R5_Wantcompute, &dev->flags))) {
set_bit(R5_Wantdrain, &dev->flags);
set_bit(R5_LOCKED, &dev->flags);
clear_bit(R5_UPTODATE, &dev->flags);
s->locked++;
} else if (test_bit(R5_InJournal, &dev->flags)) {
set_bit(R5_LOCKED, &dev->flags);
s->locked++;
}
}
if (!s->locked)
/* False alarm - nothing to do */
return;
sh->reconstruct_state = reconstruct_state_prexor_drain_run;
set_bit(STRIPE_OP_PREXOR, &s->ops_request);
set_bit(STRIPE_OP_BIODRAIN, &s->ops_request);
set_bit(STRIPE_OP_RECONSTRUCT, &s->ops_request);
}
/* keep the parity disk(s) locked while asynchronous operations
* are in flight
*/
set_bit(R5_LOCKED, &sh->dev[pd_idx].flags);
clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
s->locked++;
if (level == 6) {
int qd_idx = sh->qd_idx;
struct r5dev *dev = &sh->dev[qd_idx];
set_bit(R5_LOCKED, &dev->flags);
clear_bit(R5_UPTODATE, &dev->flags);
s->locked++;
}
if (raid5_has_ppl(sh->raid_conf) && sh->ppl_page &&
test_bit(STRIPE_OP_BIODRAIN, &s->ops_request) &&
!test_bit(STRIPE_FULL_WRITE, &sh->state) &&
test_bit(R5_Insync, &sh->dev[pd_idx].flags))
set_bit(STRIPE_OP_PARTIAL_PARITY, &s->ops_request);
pr_debug("%s: stripe %llu locked: %d ops_request: %lx\n",
__func__, (unsigned long long)sh->sector,
s->locked, s->ops_request);
}
static bool stripe_bio_overlaps(struct stripe_head *sh, struct bio *bi,
int dd_idx, int forwrite)
{
struct r5conf *conf = sh->raid_conf;
struct bio **bip;
pr_debug("checking bi b#%llu to stripe s#%llu\n",
bi->bi_iter.bi_sector, sh->sector);
/* Don't allow new IO added to stripes in batch list */
if (sh->batch_head)
return true;
if (forwrite)
bip = &sh->dev[dd_idx].towrite;
else
bip = &sh->dev[dd_idx].toread;
while (*bip && (*bip)->bi_iter.bi_sector < bi->bi_iter.bi_sector) {
if (bio_end_sector(*bip) > bi->bi_iter.bi_sector)
return true;
bip = &(*bip)->bi_next;
}
if (*bip && (*bip)->bi_iter.bi_sector < bio_end_sector(bi))
return true;
if (forwrite && raid5_has_ppl(conf)) {
/*
* With PPL only writes to consecutive data chunks within a
* stripe are allowed because for a single stripe_head we can
* only have one PPL entry at a time, which describes one data
* range. Not really an overlap, but wait_for_overlap can be
* used to handle this.
*/
sector_t sector;
sector_t first = 0;
sector_t last = 0;
int count = 0;
int i;
for (i = 0; i < sh->disks; i++) {
if (i != sh->pd_idx &&
(i == dd_idx || sh->dev[i].towrite)) {
sector = sh->dev[i].sector;
if (count == 0 || sector < first)
first = sector;
if (sector > last)
last = sector;
count++;
}
}
if (first + conf->chunk_sectors * (count - 1) != last)
return true;
}
return false;
}
static void __add_stripe_bio(struct stripe_head *sh, struct bio *bi,
int dd_idx, int forwrite, int previous)
{
struct r5conf *conf = sh->raid_conf;
struct bio **bip;
int firstwrite = 0;
if (forwrite) {
bip = &sh->dev[dd_idx].towrite;
if (!*bip)
firstwrite = 1;
} else {
bip = &sh->dev[dd_idx].toread;
}
while (*bip && (*bip)->bi_iter.bi_sector < bi->bi_iter.bi_sector)
bip = &(*bip)->bi_next;
if (!forwrite || previous)
clear_bit(STRIPE_BATCH_READY, &sh->state);
BUG_ON(*bip && bi->bi_next && (*bip) != bi->bi_next);
if (*bip)
bi->bi_next = *bip;
*bip = bi;
bio_inc_remaining(bi);
md_write_inc(conf->mddev, bi);
if (forwrite) {
/* check if page is covered */
sector_t sector = sh->dev[dd_idx].sector;
for (bi=sh->dev[dd_idx].towrite;
sector < sh->dev[dd_idx].sector + RAID5_STRIPE_SECTORS(conf) &&
bi && bi->bi_iter.bi_sector <= sector;
bi = r5_next_bio(conf, bi, sh->dev[dd_idx].sector)) {
if (bio_end_sector(bi) >= sector)
sector = bio_end_sector(bi);
}
if (sector >= sh->dev[dd_idx].sector + RAID5_STRIPE_SECTORS(conf))
if (!test_and_set_bit(R5_OVERWRITE, &sh->dev[dd_idx].flags))
sh->overwrite_disks++;
}
pr_debug("added bi b#%llu to stripe s#%llu, disk %d, logical %llu\n",
(*bip)->bi_iter.bi_sector, sh->sector, dd_idx,
sh->dev[dd_idx].sector);
if (conf->mddev->bitmap && firstwrite) {
/* Cannot hold spinlock over bitmap_startwrite,
* but must ensure this isn't added to a batch until
* we have added to the bitmap and set bm_seq.
* So set STRIPE_BITMAP_PENDING to prevent
* batching.
* If multiple __add_stripe_bio() calls race here they
* much all set STRIPE_BITMAP_PENDING. So only the first one
* to complete "bitmap_startwrite" gets to set
* STRIPE_BIT_DELAY. This is important as once a stripe
* is added to a batch, STRIPE_BIT_DELAY cannot be changed
* any more.
*/
set_bit(STRIPE_BITMAP_PENDING, &sh->state);
spin_unlock_irq(&sh->stripe_lock);
md_bitmap_startwrite(conf->mddev->bitmap, sh->sector,
RAID5_STRIPE_SECTORS(conf), 0);
spin_lock_irq(&sh->stripe_lock);
clear_bit(STRIPE_BITMAP_PENDING, &sh->state);
if (!sh->batch_head) {
sh->bm_seq = conf->seq_flush+1;
set_bit(STRIPE_BIT_DELAY, &sh->state);
}
}
}
/*
* Each stripe/dev can have one or more bios attached.
* toread/towrite point to the first in a chain.
* The bi_next chain must be in order.
*/
static bool add_stripe_bio(struct stripe_head *sh, struct bio *bi,
int dd_idx, int forwrite, int previous)
{
spin_lock_irq(&sh->stripe_lock);
if (stripe_bio_overlaps(sh, bi, dd_idx, forwrite)) {
set_bit(R5_Overlap, &sh->dev[dd_idx].flags);
spin_unlock_irq(&sh->stripe_lock);
return false;
}
__add_stripe_bio(sh, bi, dd_idx, forwrite, previous);
spin_unlock_irq(&sh->stripe_lock);
return true;
}
static void end_reshape(struct r5conf *conf);
static void stripe_set_idx(sector_t stripe, struct r5conf *conf, int previous,
struct stripe_head *sh)
{
int sectors_per_chunk =
previous ? conf->prev_chunk_sectors : conf->chunk_sectors;
int dd_idx;
int chunk_offset = sector_div(stripe, sectors_per_chunk);
int disks = previous ? conf->previous_raid_disks : conf->raid_disks;
raid5_compute_sector(conf,
stripe * (disks - conf->max_degraded)
*sectors_per_chunk + chunk_offset,
previous,
&dd_idx, sh);
}
static void
handle_failed_stripe(struct r5conf *conf, struct stripe_head *sh,
struct stripe_head_state *s, int disks)
{
int i;
BUG_ON(sh->batch_head);
for (i = disks; i--; ) {
struct bio *bi;
int bitmap_end = 0;
if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
struct md_rdev *rdev;
rcu_read_lock();
rdev = rcu_dereference(conf->disks[i].rdev);
if (rdev && test_bit(In_sync, &rdev->flags) &&
!test_bit(Faulty, &rdev->flags))
atomic_inc(&rdev->nr_pending);
else
rdev = NULL;
rcu_read_unlock();
if (rdev) {
if (!rdev_set_badblocks(
rdev,
sh->sector,
RAID5_STRIPE_SECTORS(conf), 0))
md_error(conf->mddev, rdev);
rdev_dec_pending(rdev, conf->mddev);
}
}
spin_lock_irq(&sh->stripe_lock);
/* fail all writes first */
bi = sh->dev[i].towrite;
sh->dev[i].towrite = NULL;
sh->overwrite_disks = 0;
spin_unlock_irq(&sh->stripe_lock);
if (bi)
bitmap_end = 1;
log_stripe_write_finished(sh);
if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
wake_up(&conf->wait_for_overlap);
while (bi && bi->bi_iter.bi_sector <
sh->dev[i].sector + RAID5_STRIPE_SECTORS(conf)) {
struct bio *nextbi = r5_next_bio(conf, bi, sh->dev[i].sector);
md_write_end(conf->mddev);
bio_io_error(bi);
bi = nextbi;
}
if (bitmap_end)
md_bitmap_endwrite(conf->mddev->bitmap, sh->sector,
RAID5_STRIPE_SECTORS(conf), 0, 0);
bitmap_end = 0;
/* and fail all 'written' */
bi = sh->dev[i].written;
sh->dev[i].written = NULL;
if (test_and_clear_bit(R5_SkipCopy, &sh->dev[i].flags)) {
WARN_ON(test_bit(R5_UPTODATE, &sh->dev[i].flags));
sh->dev[i].page = sh->dev[i].orig_page;
}
if (bi) bitmap_end = 1;
while (bi && bi->bi_iter.bi_sector <
sh->dev[i].sector + RAID5_STRIPE_SECTORS(conf)) {
struct bio *bi2 = r5_next_bio(conf, bi, sh->dev[i].sector);
md_write_end(conf->mddev);
bio_io_error(bi);
bi = bi2;
}
/* fail any reads if this device is non-operational and
* the data has not reached the cache yet.
*/
if (!test_bit(R5_Wantfill, &sh->dev[i].flags) &&
s->failed > conf->max_degraded &&
(!test_bit(R5_Insync, &sh->dev[i].flags) ||
test_bit(R5_ReadError, &sh->dev[i].flags))) {
spin_lock_irq(&sh->stripe_lock);
bi = sh->dev[i].toread;
sh->dev[i].toread = NULL;
spin_unlock_irq(&sh->stripe_lock);
if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
wake_up(&conf->wait_for_overlap);
if (bi)
s->to_read--;
while (bi && bi->bi_iter.bi_sector <
sh->dev[i].sector + RAID5_STRIPE_SECTORS(conf)) {
struct bio *nextbi =
r5_next_bio(conf, bi, sh->dev[i].sector);
bio_io_error(bi);
bi = nextbi;
}
}
if (bitmap_end)
md_bitmap_endwrite(conf->mddev->bitmap, sh->sector,
RAID5_STRIPE_SECTORS(conf), 0, 0);
/* If we were in the middle of a write the parity block might
* still be locked - so just clear all R5_LOCKED flags
*/
clear_bit(R5_LOCKED, &sh->dev[i].flags);
}
s->to_write = 0;
s->written = 0;
if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
if (atomic_dec_and_test(&conf->pending_full_writes))
md_wakeup_thread(conf->mddev->thread);
}
static void
handle_failed_sync(struct r5conf *conf, struct stripe_head *sh,
struct stripe_head_state *s)
{
int abort = 0;
int i;
BUG_ON(sh->batch_head);
clear_bit(STRIPE_SYNCING, &sh->state);
if (test_and_clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags))
wake_up(&conf->wait_for_overlap);
s->syncing = 0;
s->replacing = 0;
/* There is nothing more to do for sync/check/repair.
* Don't even need to abort as that is handled elsewhere
* if needed, and not always wanted e.g. if there is a known
* bad block here.
* For recover/replace we need to record a bad block on all
* non-sync devices, or abort the recovery
*/
if (test_bit(MD_RECOVERY_RECOVER, &conf->mddev->recovery)) {
/* During recovery devices cannot be removed, so
* locking and refcounting of rdevs is not needed
*/
rcu_read_lock();
for (i = 0; i < conf->raid_disks; i++) {
struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);
if (rdev
&& !test_bit(Faulty, &rdev->flags)
&& !test_bit(In_sync, &rdev->flags)
&& !rdev_set_badblocks(rdev, sh->sector,
RAID5_STRIPE_SECTORS(conf), 0))
abort = 1;
rdev = rcu_dereference(conf->disks[i].replacement);
if (rdev
&& !test_bit(Faulty, &rdev->flags)
&& !test_bit(In_sync, &rdev->flags)
&& !rdev_set_badblocks(rdev, sh->sector,
RAID5_STRIPE_SECTORS(conf), 0))
abort = 1;
}
rcu_read_unlock();
if (abort)
conf->recovery_disabled =
conf->mddev->recovery_disabled;
}
md_done_sync(conf->mddev, RAID5_STRIPE_SECTORS(conf), !abort);
}
static int want_replace(struct stripe_head *sh, int disk_idx)
{
struct md_rdev *rdev;
int rv = 0;
rcu_read_lock();
rdev = rcu_dereference(sh->raid_conf->disks[disk_idx].replacement);
if (rdev
&& !test_bit(Faulty, &rdev->flags)
&& !test_bit(In_sync, &rdev->flags)
&& (rdev->recovery_offset <= sh->sector
|| rdev->mddev->recovery_cp <= sh->sector))
rv = 1;
rcu_read_unlock();
return rv;
}
static int need_this_block(struct stripe_head *sh, struct stripe_head_state *s,
int disk_idx, int disks)
{
struct r5dev *dev = &sh->dev[disk_idx];
struct r5dev *fdev[2] = { &sh->dev[s->failed_num[0]],
&sh->dev[s->failed_num[1]] };
int i;
bool force_rcw = (sh->raid_conf->rmw_level == PARITY_DISABLE_RMW);
if (test_bit(R5_LOCKED, &dev->flags) ||
test_bit(R5_UPTODATE, &dev->flags))
/* No point reading this as we already have it or have
* decided to get it.
*/
return 0;
if (dev->toread ||
(dev->towrite && !test_bit(R5_OVERWRITE, &dev->flags)))
/* We need this block to directly satisfy a request */
return 1;
if (s->syncing || s->expanding ||
(s->replacing && want_replace(sh, disk_idx)))
/* When syncing, or expanding we read everything.
* When replacing, we need the replaced block.
*/
return 1;
if ((s->failed >= 1 && fdev[0]->toread) ||
(s->failed >= 2 && fdev[1]->toread))
/* If we want to read from a failed device, then
* we need to actually read every other device.
*/
return 1;
/* Sometimes neither read-modify-write nor reconstruct-write
* cycles can work. In those cases we read every block we
* can. Then the parity-update is certain to have enough to
* work with.
* This can only be a problem when we need to write something,
* and some device has failed. If either of those tests
* fail we need look no further.
*/
if (!s->failed || !s->to_write)
return 0;
if (test_bit(R5_Insync, &dev->flags) &&
!test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
/* Pre-reads at not permitted until after short delay
* to gather multiple requests. However if this
* device is no Insync, the block could only be computed
* and there is no need to delay that.
*/
return 0;
for (i = 0; i < s->failed && i < 2; i++) {
if (fdev[i]->towrite &&
!test_bit(R5_UPTODATE, &fdev[i]->flags) &&
!test_bit(R5_OVERWRITE, &fdev[i]->flags))
/* If we have a partial write to a failed
* device, then we will need to reconstruct
* the content of that device, so all other
* devices must be read.
*/
return 1;
if (s->failed >= 2 &&
(fdev[i]->towrite ||
s->failed_num[i] == sh->pd_idx ||
s->failed_num[i] == sh->qd_idx) &&
!test_bit(R5_UPTODATE, &fdev[i]->flags))
/* In max degraded raid6, If the failed disk is P, Q,
* or we want to read the failed disk, we need to do
* reconstruct-write.
*/
force_rcw = true;
}
/* If we are forced to do a reconstruct-write, because parity
* cannot be trusted and we are currently recovering it, there
* is extra need to be careful.
* If one of the devices that we would need to read, because
* it is not being overwritten (and maybe not written at all)
* is missing/faulty, then we need to read everything we can.
*/
if (!force_rcw &&
sh->sector < sh->raid_conf->mddev->recovery_cp)
/* reconstruct-write isn't being forced */
return 0;
for (i = 0; i < s->failed && i < 2; i++) {
if (s->failed_num[i] != sh->pd_idx &&
s->failed_num[i] != sh->qd_idx &&
!test_bit(R5_UPTODATE, &fdev[i]->flags) &&
!test_bit(R5_OVERWRITE, &fdev[i]->flags))
return 1;
}
return 0;
}
/* fetch_block - checks the given member device to see if its data needs
* to be read or computed to satisfy a request.
*
* Returns 1 when no more member devices need to be checked, otherwise returns
* 0 to tell the loop in handle_stripe_fill to continue
*/
static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s,
int disk_idx, int disks)
{
struct r5dev *dev = &sh->dev[disk_idx];
/* is the data in this block needed, and can we get it? */
if (need_this_block(sh, s, disk_idx, disks)) {
/* we would like to get this block, possibly by computing it,
* otherwise read it if the backing disk is insync
*/
BUG_ON(test_bit(R5_Wantcompute, &dev->flags));
BUG_ON(test_bit(R5_Wantread, &dev->flags));
BUG_ON(sh->batch_head);
/*
* In the raid6 case if the only non-uptodate disk is P
* then we already trusted P to compute the other failed
* drives. It is safe to compute rather than re-read P.
* In other cases we only compute blocks from failed
* devices, otherwise check/repair might fail to detect
* a real inconsistency.
*/
if ((s->uptodate == disks - 1) &&
((sh->qd_idx >= 0 && sh->pd_idx == disk_idx) ||
(s->failed && (disk_idx == s->failed_num[0] ||
disk_idx == s->failed_num[1])))) {
/* have disk failed, and we're requested to fetch it;
* do compute it
*/
pr_debug("Computing stripe %llu block %d\n",
(unsigned long long)sh->sector, disk_idx);
set_bit(STRIPE_COMPUTE_RUN, &sh->state);
set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
set_bit(R5_Wantcompute, &dev->flags);
sh->ops.target = disk_idx;
sh->ops.target2 = -1; /* no 2nd target */
s->req_compute = 1;
/* Careful: from this point on 'uptodate' is in the eye
* of raid_run_ops which services 'compute' operations
* before writes. R5_Wantcompute flags a block that will
* be R5_UPTODATE by the time it is needed for a
* subsequent operation.
*/
s->uptodate++;
return 1;
} else if (s->uptodate == disks-2 && s->failed >= 2) {
/* Computing 2-failure is *very* expensive; only
* do it if failed >= 2
*/
int other;
for (other = disks; other--; ) {
if (other == disk_idx)
continue;
if (!test_bit(R5_UPTODATE,
&sh->dev[other].flags))
break;
}
BUG_ON(other < 0);
pr_debug("Computing stripe %llu blocks %d,%d\n",
(unsigned long long)sh->sector,
disk_idx, other);
set_bit(STRIPE_COMPUTE_RUN, &sh->state);
set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
set_bit(R5_Wantcompute, &sh->dev[disk_idx].flags);
set_bit(R5_Wantcompute, &sh->dev[other].flags);
sh->ops.target = disk_idx;
sh->ops.target2 = other;
s->uptodate += 2;
s->req_compute = 1;
return 1;
} else if (test_bit(R5_Insync, &dev->flags)) {
set_bit(R5_LOCKED, &dev->flags);
set_bit(R5_Wantread, &dev->flags);
s->locked++;
pr_debug("Reading block %d (sync=%d)\n",
disk_idx, s->syncing);
}
}
return 0;
}
/*
* handle_stripe_fill - read or compute data to satisfy pending requests.
*/
static void handle_stripe_fill(struct stripe_head *sh,
struct stripe_head_state *s,
int disks)
{
int i;
/* look for blocks to read/compute, skip this if a compute
* is already in flight, or if the stripe contents are in the
* midst of changing due to a write
*/
if (!test_bit(STRIPE_COMPUTE_RUN, &sh->state) && !sh->check_state &&
!sh->reconstruct_state) {
/*
* For degraded stripe with data in journal, do not handle
* read requests yet, instead, flush the stripe to raid
* disks first, this avoids handling complex rmw of write
* back cache (prexor with orig_page, and then xor with
* page) in the read path
*/
if (s->to_read && s->injournal && s->failed) {
if (test_bit(STRIPE_R5C_CACHING, &sh->state))
r5c_make_stripe_write_out(sh);
goto out;
}
for (i = disks; i--; )
if (fetch_block(sh, s, i, disks))
break;
}
out:
set_bit(STRIPE_HANDLE, &sh->state);
}
static void break_stripe_batch_list(struct stripe_head *head_sh,
unsigned long handle_flags);
/* handle_stripe_clean_event
* any written block on an uptodate or failed drive can be returned.
* Note that if we 'wrote' to a failed drive, it will be UPTODATE, but
* never LOCKED, so we don't need to test 'failed' directly.
*/
static void handle_stripe_clean_event(struct r5conf *conf,
struct stripe_head *sh, int disks)
{
int i;
struct r5dev *dev;
int discard_pending = 0;
struct stripe_head *head_sh = sh;
bool do_endio = false;
for (i = disks; i--; )
if (sh->dev[i].written) {
dev = &sh->dev[i];
if (!test_bit(R5_LOCKED, &dev->flags) &&
(test_bit(R5_UPTODATE, &dev->flags) ||
test_bit(R5_Discard, &dev->flags) ||
test_bit(R5_SkipCopy, &dev->flags))) {
/* We can return any write requests */
struct bio *wbi, *wbi2;
pr_debug("Return write for disc %d\n", i);
if (test_and_clear_bit(R5_Discard, &dev->flags))
clear_bit(R5_UPTODATE, &dev->flags);
if (test_and_clear_bit(R5_SkipCopy, &dev->flags)) {
WARN_ON(test_bit(R5_UPTODATE, &dev->flags));
}
do_endio = true;
returnbi:
dev->page = dev->orig_page;
wbi = dev->written;
dev->written = NULL;
while (wbi && wbi->bi_iter.bi_sector <
dev->sector + RAID5_STRIPE_SECTORS(conf)) {
wbi2 = r5_next_bio(conf, wbi, dev->sector);
md_write_end(conf->mddev);
bio_endio(wbi);
wbi = wbi2;
}
md_bitmap_endwrite(conf->mddev->bitmap, sh->sector,
RAID5_STRIPE_SECTORS(conf),
!test_bit(STRIPE_DEGRADED, &sh->state),
0);
if (head_sh->batch_head) {
sh = list_first_entry(&sh->batch_list,
struct stripe_head,
batch_list);
if (sh != head_sh) {
dev = &sh->dev[i];
goto returnbi;
}
}
sh = head_sh;
dev = &sh->dev[i];
} else if (test_bit(R5_Discard, &dev->flags))
discard_pending = 1;
}
log_stripe_write_finished(sh);
if (!discard_pending &&
test_bit(R5_Discard, &sh->dev[sh->pd_idx].flags)) {
int hash;
clear_bit(R5_Discard, &sh->dev[sh->pd_idx].flags);
clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
if (sh->qd_idx >= 0) {
clear_bit(R5_Discard, &sh->dev[sh->qd_idx].flags);
clear_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags);
}
/* now that discard is done we can proceed with any sync */
clear_bit(STRIPE_DISCARD, &sh->state);
/*
* SCSI discard will change some bio fields and the stripe has
* no updated data, so remove it from hash list and the stripe
* will be reinitialized
*/
unhash:
hash = sh->hash_lock_index;
spin_lock_irq(conf->hash_locks + hash);
remove_hash(sh);
spin_unlock_irq(conf->hash_locks + hash);
if (head_sh->batch_head) {
sh = list_first_entry(&sh->batch_list,
struct stripe_head, batch_list);
if (sh != head_sh)
goto unhash;
}
sh = head_sh;
if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state))
set_bit(STRIPE_HANDLE, &sh->state);
}
if (test_and_clear_bit(STRIPE_FULL_WRITE, &sh->state))
if (atomic_dec_and_test(&conf->pending_full_writes))
md_wakeup_thread(conf->mddev->thread);
if (head_sh->batch_head && do_endio)
break_stripe_batch_list(head_sh, STRIPE_EXPAND_SYNC_FLAGS);
}
/*
* For RMW in write back cache, we need extra page in prexor to store the
* old data. This page is stored in dev->orig_page.
*
* This function checks whether we have data for prexor. The exact logic
* is:
* R5_UPTODATE && (!R5_InJournal || R5_OrigPageUPTDODATE)
*/
static inline bool uptodate_for_rmw(struct r5dev *dev)
{
return (test_bit(R5_UPTODATE, &dev->flags)) &&
(!test_bit(R5_InJournal, &dev->flags) ||
test_bit(R5_OrigPageUPTDODATE, &dev->flags));
}
static int handle_stripe_dirtying(struct r5conf *conf,
struct stripe_head *sh,
struct stripe_head_state *s,
int disks)
{
int rmw = 0, rcw = 0, i;
sector_t recovery_cp = conf->mddev->recovery_cp;
/* Check whether resync is now happening or should start.
* If yes, then the array is dirty (after unclean shutdown or
* initial creation), so parity in some stripes might be inconsistent.
* In this case, we need to always do reconstruct-write, to ensure
* that in case of drive failure or read-error correction, we
* generate correct data from the parity.
*/
if (conf->rmw_level == PARITY_DISABLE_RMW ||
(recovery_cp < MaxSector && sh->sector >= recovery_cp &&
s->failed == 0)) {
/* Calculate the real rcw later - for now make it
* look like rcw is cheaper
*/
rcw = 1; rmw = 2;
pr_debug("force RCW rmw_level=%u, recovery_cp=%llu sh->sector=%llu\n",
conf->rmw_level, (unsigned long long)recovery_cp,
(unsigned long long)sh->sector);
} else for (i = disks; i--; ) {
/* would I have to read this buffer for read_modify_write */
struct r5dev *dev = &sh->dev[i];
if (((dev->towrite && !delay_towrite(conf, dev, s)) ||
i == sh->pd_idx || i == sh->qd_idx ||
test_bit(R5_InJournal, &dev->flags)) &&
!test_bit(R5_LOCKED, &dev->flags) &&
!(uptodate_for_rmw(dev) ||
test_bit(R5_Wantcompute, &dev->flags))) {
if (test_bit(R5_Insync, &dev->flags))
rmw++;
else
rmw += 2*disks; /* cannot read it */
}
/* Would I have to read this buffer for reconstruct_write */
if (!test_bit(R5_OVERWRITE, &dev->flags) &&
i != sh->pd_idx && i != sh->qd_idx &&
!test_bit(R5_LOCKED, &dev->flags) &&
!(test_bit(R5_UPTODATE, &dev->flags) ||
test_bit(R5_Wantcompute, &dev->flags))) {
if (test_bit(R5_Insync, &dev->flags))
rcw++;
else
rcw += 2*disks;
}
}
pr_debug("for sector %llu state 0x%lx, rmw=%d rcw=%d\n",
(unsigned long long)sh->sector, sh->state, rmw, rcw);
set_bit(STRIPE_HANDLE, &sh->state);
if ((rmw < rcw || (rmw == rcw && conf->rmw_level == PARITY_PREFER_RMW)) && rmw > 0) {
/* prefer read-modify-write, but need to get some data */
if (conf->mddev->queue)
blk_add_trace_msg(conf->mddev->queue,
"raid5 rmw %llu %d",
(unsigned long long)sh->sector, rmw);
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
if (test_bit(R5_InJournal, &dev->flags) &&
dev->page == dev->orig_page &&
!test_bit(R5_LOCKED, &sh->dev[sh->pd_idx].flags)) {
/* alloc page for prexor */
struct page *p = alloc_page(GFP_NOIO);
if (p) {
dev->orig_page = p;
continue;
}
/*
* alloc_page() failed, try use
* disk_info->extra_page
*/
if (!test_and_set_bit(R5C_EXTRA_PAGE_IN_USE,
&conf->cache_state)) {
r5c_use_extra_page(sh);
break;
}
/* extra_page in use, add to delayed_list */
set_bit(STRIPE_DELAYED, &sh->state);
s->waiting_extra_page = 1;
return -EAGAIN;
}
}
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
if (((dev->towrite && !delay_towrite(conf, dev, s)) ||
i == sh->pd_idx || i == sh->qd_idx ||
test_bit(R5_InJournal, &dev->flags)) &&
!test_bit(R5_LOCKED, &dev->flags) &&
!(uptodate_for_rmw(dev) ||
test_bit(R5_Wantcompute, &dev->flags)) &&
test_bit(R5_Insync, &dev->flags)) {
if (test_bit(STRIPE_PREREAD_ACTIVE,
&sh->state)) {
pr_debug("Read_old block %d for r-m-w\n",
i);
set_bit(R5_LOCKED, &dev->flags);
set_bit(R5_Wantread, &dev->flags);
s->locked++;
} else
set_bit(STRIPE_DELAYED, &sh->state);
}
}
}
if ((rcw < rmw || (rcw == rmw && conf->rmw_level != PARITY_PREFER_RMW)) && rcw > 0) {
/* want reconstruct write, but need to get some data */
int qread =0;
rcw = 0;
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
if (!test_bit(R5_OVERWRITE, &dev->flags) &&
i != sh->pd_idx && i != sh->qd_idx &&
!test_bit(R5_LOCKED, &dev->flags) &&
!(test_bit(R5_UPTODATE, &dev->flags) ||
test_bit(R5_Wantcompute, &dev->flags))) {
rcw++;
if (test_bit(R5_Insync, &dev->flags) &&
test_bit(STRIPE_PREREAD_ACTIVE,
&sh->state)) {
pr_debug("Read_old block "
"%d for Reconstruct\n", i);
set_bit(R5_LOCKED, &dev->flags);
set_bit(R5_Wantread, &dev->flags);
s->locked++;
qread++;
} else
set_bit(STRIPE_DELAYED, &sh->state);
}
}
if (rcw && conf->mddev->queue)
blk_add_trace_msg(conf->mddev->queue, "raid5 rcw %llu %d %d %d",
(unsigned long long)sh->sector,
rcw, qread, test_bit(STRIPE_DELAYED, &sh->state));
}
if (rcw > disks && rmw > disks &&
!test_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
set_bit(STRIPE_DELAYED, &sh->state);
/* now if nothing is locked, and if we have enough data,
* we can start a write request
*/
/* since handle_stripe can be called at any time we need to handle the
* case where a compute block operation has been submitted and then a
* subsequent call wants to start a write request. raid_run_ops only
* handles the case where compute block and reconstruct are requested
* simultaneously. If this is not the case then new writes need to be
* held off until the compute completes.
*/
if ((s->req_compute || !test_bit(STRIPE_COMPUTE_RUN, &sh->state)) &&
(s->locked == 0 && (rcw == 0 || rmw == 0) &&
!test_bit(STRIPE_BIT_DELAY, &sh->state)))
schedule_reconstruction(sh, s, rcw == 0, 0);
return 0;
}
static void handle_parity_checks5(struct r5conf *conf, struct stripe_head *sh,
struct stripe_head_state *s, int disks)
{
struct r5dev *dev = NULL;
BUG_ON(sh->batch_head);
set_bit(STRIPE_HANDLE, &sh->state);
switch (sh->check_state) {
case check_state_idle:
/* start a new check operation if there are no failures */
if (s->failed == 0) {
BUG_ON(s->uptodate != disks);
sh->check_state = check_state_run;
set_bit(STRIPE_OP_CHECK, &s->ops_request);
clear_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags);
s->uptodate--;
break;
}
dev = &sh->dev[s->failed_num[0]];
fallthrough;
case check_state_compute_result:
sh->check_state = check_state_idle;
if (!dev)
dev = &sh->dev[sh->pd_idx];
/* check that a write has not made the stripe insync */
if (test_bit(STRIPE_INSYNC, &sh->state))
break;
/* either failed parity check, or recovery is happening */
BUG_ON(!test_bit(R5_UPTODATE, &dev->flags));
BUG_ON(s->uptodate != disks);
set_bit(R5_LOCKED, &dev->flags);
s->locked++;
set_bit(R5_Wantwrite, &dev->flags);
clear_bit(STRIPE_DEGRADED, &sh->state);
set_bit(STRIPE_INSYNC, &sh->state);
break;
case check_state_run:
break; /* we will be called again upon completion */
case check_state_check_result:
sh->check_state = check_state_idle;
/* if a failure occurred during the check operation, leave
* STRIPE_INSYNC not set and let the stripe be handled again
*/
if (s->failed)
break;
/* handle a successful check operation, if parity is correct
* we are done. Otherwise update the mismatch count and repair
* parity if !MD_RECOVERY_CHECK
*/
if ((sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) == 0)
/* parity is correct (on disc,
* not in buffer any more)
*/
set_bit(STRIPE_INSYNC, &sh->state);
else {
atomic64_add(RAID5_STRIPE_SECTORS(conf), &conf->mddev->resync_mismatches);
if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) {
/* don't try to repair!! */
set_bit(STRIPE_INSYNC, &sh->state);
pr_warn_ratelimited("%s: mismatch sector in range "
"%llu-%llu\n", mdname(conf->mddev),
(unsigned long long) sh->sector,
(unsigned long long) sh->sector +
RAID5_STRIPE_SECTORS(conf));
} else {
sh->check_state = check_state_compute_run;
set_bit(STRIPE_COMPUTE_RUN, &sh->state);
set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
set_bit(R5_Wantcompute,
&sh->dev[sh->pd_idx].flags);
sh->ops.target = sh->pd_idx;
sh->ops.target2 = -1;
s->uptodate++;
}
}
break;
case check_state_compute_run:
break;
default:
pr_err("%s: unknown check_state: %d sector: %llu\n",
__func__, sh->check_state,
(unsigned long long) sh->sector);
BUG();
}
}
static void handle_parity_checks6(struct r5conf *conf, struct stripe_head *sh,
struct stripe_head_state *s,
int disks)
{
int pd_idx = sh->pd_idx;
int qd_idx = sh->qd_idx;
struct r5dev *dev;
BUG_ON(sh->batch_head);
set_bit(STRIPE_HANDLE, &sh->state);
BUG_ON(s->failed > 2);
/* Want to check and possibly repair P and Q.
* However there could be one 'failed' device, in which
* case we can only check one of them, possibly using the
* other to generate missing data
*/
switch (sh->check_state) {
case check_state_idle:
/* start a new check operation if there are < 2 failures */
if (s->failed == s->q_failed) {
/* The only possible failed device holds Q, so it
* makes sense to check P (If anything else were failed,
* we would have used P to recreate it).
*/
sh->check_state = check_state_run;
}
if (!s->q_failed && s->failed < 2) {
/* Q is not failed, and we didn't use it to generate
* anything, so it makes sense to check it
*/
if (sh->check_state == check_state_run)
sh->check_state = check_state_run_pq;
else
sh->check_state = check_state_run_q;
}
/* discard potentially stale zero_sum_result */
sh->ops.zero_sum_result = 0;
if (sh->check_state == check_state_run) {
/* async_xor_zero_sum destroys the contents of P */
clear_bit(R5_UPTODATE, &sh->dev[pd_idx].flags);
s->uptodate--;
}
if (sh->check_state >= check_state_run &&
sh->check_state <= check_state_run_pq) {
/* async_syndrome_zero_sum preserves P and Q, so
* no need to mark them !uptodate here
*/
set_bit(STRIPE_OP_CHECK, &s->ops_request);
break;
}
/* we have 2-disk failure */
BUG_ON(s->failed != 2);
fallthrough;
case check_state_compute_result:
sh->check_state = check_state_idle;
/* check that a write has not made the stripe insync */
if (test_bit(STRIPE_INSYNC, &sh->state))
break;
/* now write out any block on a failed drive,
* or P or Q if they were recomputed
*/
dev = NULL;
if (s->failed == 2) {
dev = &sh->dev[s->failed_num[1]];
s->locked++;
set_bit(R5_LOCKED, &dev->flags);
set_bit(R5_Wantwrite, &dev->flags);
}
if (s->failed >= 1) {
dev = &sh->dev[s->failed_num[0]];
s->locked++;
set_bit(R5_LOCKED, &dev->flags);
set_bit(R5_Wantwrite, &dev->flags);
}
if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
dev = &sh->dev[pd_idx];
s->locked++;
set_bit(R5_LOCKED, &dev->flags);
set_bit(R5_Wantwrite, &dev->flags);
}
if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
dev = &sh->dev[qd_idx];
s->locked++;
set_bit(R5_LOCKED, &dev->flags);
set_bit(R5_Wantwrite, &dev->flags);
}
if (WARN_ONCE(dev && !test_bit(R5_UPTODATE, &dev->flags),
"%s: disk%td not up to date\n",
mdname(conf->mddev),
dev - (struct r5dev *) &sh->dev)) {
clear_bit(R5_LOCKED, &dev->flags);
clear_bit(R5_Wantwrite, &dev->flags);
s->locked--;
}
clear_bit(STRIPE_DEGRADED, &sh->state);
set_bit(STRIPE_INSYNC, &sh->state);
break;
case check_state_run:
case check_state_run_q:
case check_state_run_pq:
break; /* we will be called again upon completion */
case check_state_check_result:
sh->check_state = check_state_idle;
/* handle a successful check operation, if parity is correct
* we are done. Otherwise update the mismatch count and repair
* parity if !MD_RECOVERY_CHECK
*/
if (sh->ops.zero_sum_result == 0) {
/* both parities are correct */
if (!s->failed)
set_bit(STRIPE_INSYNC, &sh->state);
else {
/* in contrast to the raid5 case we can validate
* parity, but still have a failure to write
* back
*/
sh->check_state = check_state_compute_result;
/* Returning at this point means that we may go
* off and bring p and/or q uptodate again so
* we make sure to check zero_sum_result again
* to verify if p or q need writeback
*/
}
} else {
atomic64_add(RAID5_STRIPE_SECTORS(conf), &conf->mddev->resync_mismatches);
if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery)) {
/* don't try to repair!! */
set_bit(STRIPE_INSYNC, &sh->state);
pr_warn_ratelimited("%s: mismatch sector in range "
"%llu-%llu\n", mdname(conf->mddev),
(unsigned long long) sh->sector,
(unsigned long long) sh->sector +
RAID5_STRIPE_SECTORS(conf));
} else {
int *target = &sh->ops.target;
sh->ops.target = -1;
sh->ops.target2 = -1;
sh->check_state = check_state_compute_run;
set_bit(STRIPE_COMPUTE_RUN, &sh->state);
set_bit(STRIPE_OP_COMPUTE_BLK, &s->ops_request);
if (sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) {
set_bit(R5_Wantcompute,
&sh->dev[pd_idx].flags);
*target = pd_idx;
target = &sh->ops.target2;
s->uptodate++;
}
if (sh->ops.zero_sum_result & SUM_CHECK_Q_RESULT) {
set_bit(R5_Wantcompute,
&sh->dev[qd_idx].flags);
*target = qd_idx;
s->uptodate++;
}
}
}
break;
case check_state_compute_run:
break;
default:
pr_warn("%s: unknown check_state: %d sector: %llu\n",
__func__, sh->check_state,
(unsigned long long) sh->sector);
BUG();
}
}
static void handle_stripe_expansion(struct r5conf *conf, struct stripe_head *sh)
{
int i;
/* We have read all the blocks in this stripe and now we need to
* copy some of them into a target stripe for expand.
*/
struct dma_async_tx_descriptor *tx = NULL;
BUG_ON(sh->batch_head);
clear_bit(STRIPE_EXPAND_SOURCE, &sh->state);
for (i = 0; i < sh->disks; i++)
if (i != sh->pd_idx && i != sh->qd_idx) {
int dd_idx, j;
struct stripe_head *sh2;
struct async_submit_ctl submit;
sector_t bn = raid5_compute_blocknr(sh, i, 1);
sector_t s = raid5_compute_sector(conf, bn, 0,
&dd_idx, NULL);
sh2 = raid5_get_active_stripe(conf, NULL, s,
R5_GAS_NOBLOCK | R5_GAS_NOQUIESCE);
if (sh2 == NULL)
/* so far only the early blocks of this stripe
* have been requested. When later blocks
* get requested, we will try again
*/
continue;
if (!test_bit(STRIPE_EXPANDING, &sh2->state) ||
test_bit(R5_Expanded, &sh2->dev[dd_idx].flags)) {
/* must have already done this block */
raid5_release_stripe(sh2);
continue;
}
/* place all the copies on one channel */
init_async_submit(&submit, 0, tx, NULL, NULL, NULL);
tx = async_memcpy(sh2->dev[dd_idx].page,
sh->dev[i].page, sh2->dev[dd_idx].offset,
sh->dev[i].offset, RAID5_STRIPE_SIZE(conf),
&submit);
set_bit(R5_Expanded, &sh2->dev[dd_idx].flags);
set_bit(R5_UPTODATE, &sh2->dev[dd_idx].flags);
for (j = 0; j < conf->raid_disks; j++)
if (j != sh2->pd_idx &&
j != sh2->qd_idx &&
!test_bit(R5_Expanded, &sh2->dev[j].flags))
break;
if (j == conf->raid_disks) {
set_bit(STRIPE_EXPAND_READY, &sh2->state);
set_bit(STRIPE_HANDLE, &sh2->state);
}
raid5_release_stripe(sh2);
}
/* done submitting copies, wait for them to complete */
async_tx_quiesce(&tx);
}
/*
* handle_stripe - do things to a stripe.
*
* We lock the stripe by setting STRIPE_ACTIVE and then examine the
* state of various bits to see what needs to be done.
* Possible results:
* return some read requests which now have data
* return some write requests which are safely on storage
* schedule a read on some buffers
* schedule a write of some buffers
* return confirmation of parity correctness
*
*/
static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s)
{
struct r5conf *conf = sh->raid_conf;
int disks = sh->disks;
struct r5dev *dev;
int i;
int do_recovery = 0;
memset(s, 0, sizeof(*s));
s->expanding = test_bit(STRIPE_EXPAND_SOURCE, &sh->state) && !sh->batch_head;
s->expanded = test_bit(STRIPE_EXPAND_READY, &sh->state) && !sh->batch_head;
s->failed_num[0] = -1;
s->failed_num[1] = -1;
s->log_failed = r5l_log_disk_error(conf);
/* Now to look around and see what can be done */
rcu_read_lock();
for (i=disks; i--; ) {
struct md_rdev *rdev;
sector_t first_bad;
int bad_sectors;
int is_bad = 0;
dev = &sh->dev[i];
pr_debug("check %d: state 0x%lx read %p write %p written %p\n",
i, dev->flags,
dev->toread, dev->towrite, dev->written);
/* maybe we can reply to a read
*
* new wantfill requests are only permitted while
* ops_complete_biofill is guaranteed to be inactive
*/
if (test_bit(R5_UPTODATE, &dev->flags) && dev->toread &&
!test_bit(STRIPE_BIOFILL_RUN, &sh->state))
set_bit(R5_Wantfill, &dev->flags);
/* now count some things */
if (test_bit(R5_LOCKED, &dev->flags))
s->locked++;
if (test_bit(R5_UPTODATE, &dev->flags))
s->uptodate++;
if (test_bit(R5_Wantcompute, &dev->flags)) {
s->compute++;
BUG_ON(s->compute > 2);
}
if (test_bit(R5_Wantfill, &dev->flags))
s->to_fill++;
else if (dev->toread)
s->to_read++;
if (dev->towrite) {
s->to_write++;
if (!test_bit(R5_OVERWRITE, &dev->flags))
s->non_overwrite++;
}
if (dev->written)
s->written++;
/* Prefer to use the replacement for reads, but only
* if it is recovered enough and has no bad blocks.
*/
rdev = rcu_dereference(conf->disks[i].replacement);
if (rdev && !test_bit(Faulty, &rdev->flags) &&
rdev->recovery_offset >= sh->sector + RAID5_STRIPE_SECTORS(conf) &&
!is_badblock(rdev, sh->sector, RAID5_STRIPE_SECTORS(conf),
&first_bad, &bad_sectors))
set_bit(R5_ReadRepl, &dev->flags);
else {
if (rdev && !test_bit(Faulty, &rdev->flags))
set_bit(R5_NeedReplace, &dev->flags);
else
clear_bit(R5_NeedReplace, &dev->flags);
rdev = rcu_dereference(conf->disks[i].rdev);
clear_bit(R5_ReadRepl, &dev->flags);
}
if (rdev && test_bit(Faulty, &rdev->flags))
rdev = NULL;
if (rdev) {
is_bad = is_badblock(rdev, sh->sector, RAID5_STRIPE_SECTORS(conf),
&first_bad, &bad_sectors);
if (s->blocked_rdev == NULL
&& (test_bit(Blocked, &rdev->flags)
|| is_bad < 0)) {
if (is_bad < 0)
set_bit(BlockedBadBlocks,
&rdev->flags);
s->blocked_rdev = rdev;
atomic_inc(&rdev->nr_pending);
}
}
clear_bit(R5_Insync, &dev->flags);
if (!rdev)
/* Not in-sync */;
else if (is_bad) {
/* also not in-sync */
if (!test_bit(WriteErrorSeen, &rdev->flags) &&
test_bit(R5_UPTODATE, &dev->flags)) {
/* treat as in-sync, but with a read error
* which we can now try to correct
*/
set_bit(R5_Insync, &dev->flags);
set_bit(R5_ReadError, &dev->flags);
}
} else if (test_bit(In_sync, &rdev->flags))
set_bit(R5_Insync, &dev->flags);
else if (sh->sector + RAID5_STRIPE_SECTORS(conf) <= rdev->recovery_offset)
/* in sync if before recovery_offset */
set_bit(R5_Insync, &dev->flags);
else if (test_bit(R5_UPTODATE, &dev->flags) &&
test_bit(R5_Expanded, &dev->flags))
/* If we've reshaped into here, we assume it is Insync.
* We will shortly update recovery_offset to make
* it official.
*/
set_bit(R5_Insync, &dev->flags);
if (test_bit(R5_WriteError, &dev->flags)) {
/* This flag does not apply to '.replacement'
* only to .rdev, so make sure to check that*/
struct md_rdev *rdev2 = rcu_dereference(
conf->disks[i].rdev);
if (rdev2 == rdev)
clear_bit(R5_Insync, &dev->flags);
if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
s->handle_bad_blocks = 1;
atomic_inc(&rdev2->nr_pending);
} else
clear_bit(R5_WriteError, &dev->flags);
}
if (test_bit(R5_MadeGood, &dev->flags)) {
/* This flag does not apply to '.replacement'
* only to .rdev, so make sure to check that*/
struct md_rdev *rdev2 = rcu_dereference(
conf->disks[i].rdev);
if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
s->handle_bad_blocks = 1;
atomic_inc(&rdev2->nr_pending);
} else
clear_bit(R5_MadeGood, &dev->flags);
}
if (test_bit(R5_MadeGoodRepl, &dev->flags)) {
struct md_rdev *rdev2 = rcu_dereference(
conf->disks[i].replacement);
if (rdev2 && !test_bit(Faulty, &rdev2->flags)) {
s->handle_bad_blocks = 1;
atomic_inc(&rdev2->nr_pending);
} else
clear_bit(R5_MadeGoodRepl, &dev->flags);
}
if (!test_bit(R5_Insync, &dev->flags)) {
/* The ReadError flag will just be confusing now */
clear_bit(R5_ReadError, &dev->flags);
clear_bit(R5_ReWrite, &dev->flags);
}
if (test_bit(R5_ReadError, &dev->flags))
clear_bit(R5_Insync, &dev->flags);
if (!test_bit(R5_Insync, &dev->flags)) {
if (s->failed < 2)
s->failed_num[s->failed] = i;
s->failed++;
if (rdev && !test_bit(Faulty, &rdev->flags))
do_recovery = 1;
else if (!rdev) {
rdev = rcu_dereference(
conf->disks[i].replacement);
if (rdev && !test_bit(Faulty, &rdev->flags))
do_recovery = 1;
}
}
if (test_bit(R5_InJournal, &dev->flags))
s->injournal++;
if (test_bit(R5_InJournal, &dev->flags) && dev->written)
s->just_cached++;
}
if (test_bit(STRIPE_SYNCING, &sh->state)) {
/* If there is a failed device being replaced,
* we must be recovering.
* else if we are after recovery_cp, we must be syncing
* else if MD_RECOVERY_REQUESTED is set, we also are syncing.
* else we can only be replacing
* sync and recovery both need to read all devices, and so
* use the same flag.
*/
if (do_recovery ||
sh->sector >= conf->mddev->recovery_cp ||
test_bit(MD_RECOVERY_REQUESTED, &(conf->mddev->recovery)))
s->syncing = 1;
else
s->replacing = 1;
}
rcu_read_unlock();
}
/*
* Return '1' if this is a member of batch, or '0' if it is a lone stripe or
* a head which can now be handled.
*/
static int clear_batch_ready(struct stripe_head *sh)
{
struct stripe_head *tmp;
if (!test_and_clear_bit(STRIPE_BATCH_READY, &sh->state))
return (sh->batch_head && sh->batch_head != sh);
spin_lock(&sh->stripe_lock);
if (!sh->batch_head) {
spin_unlock(&sh->stripe_lock);
return 0;
}
/*
* this stripe could be added to a batch list before we check
* BATCH_READY, skips it
*/
if (sh->batch_head != sh) {
spin_unlock(&sh->stripe_lock);
return 1;
}
spin_lock(&sh->batch_lock);
list_for_each_entry(tmp, &sh->batch_list, batch_list)
clear_bit(STRIPE_BATCH_READY, &tmp->state);
spin_unlock(&sh->batch_lock);
spin_unlock(&sh->stripe_lock);
/*
* BATCH_READY is cleared, no new stripes can be added.
* batch_list can be accessed without lock
*/
return 0;
}
static void break_stripe_batch_list(struct stripe_head *head_sh,
unsigned long handle_flags)
{
struct stripe_head *sh, *next;
int i;
int do_wakeup = 0;
list_for_each_entry_safe(sh, next, &head_sh->batch_list, batch_list) {
list_del_init(&sh->batch_list);
WARN_ONCE(sh->state & ((1 << STRIPE_ACTIVE) |
(1 << STRIPE_SYNCING) |
(1 << STRIPE_REPLACED) |
(1 << STRIPE_DELAYED) |
(1 << STRIPE_BIT_DELAY) |
(1 << STRIPE_FULL_WRITE) |
(1 << STRIPE_BIOFILL_RUN) |
(1 << STRIPE_COMPUTE_RUN) |
(1 << STRIPE_DISCARD) |
(1 << STRIPE_BATCH_READY) |
(1 << STRIPE_BATCH_ERR) |
(1 << STRIPE_BITMAP_PENDING)),
"stripe state: %lx\n", sh->state);
WARN_ONCE(head_sh->state & ((1 << STRIPE_DISCARD) |
(1 << STRIPE_REPLACED)),
"head stripe state: %lx\n", head_sh->state);
set_mask_bits(&sh->state, ~(STRIPE_EXPAND_SYNC_FLAGS |
(1 << STRIPE_PREREAD_ACTIVE) |
(1 << STRIPE_DEGRADED) |
(1 << STRIPE_ON_UNPLUG_LIST)),
head_sh->state & (1 << STRIPE_INSYNC));
sh->check_state = head_sh->check_state;
sh->reconstruct_state = head_sh->reconstruct_state;
spin_lock_irq(&sh->stripe_lock);
sh->batch_head = NULL;
spin_unlock_irq(&sh->stripe_lock);
for (i = 0; i < sh->disks; i++) {
if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
do_wakeup = 1;
sh->dev[i].flags = head_sh->dev[i].flags &
(~((1 << R5_WriteError) | (1 << R5_Overlap)));
}
if (handle_flags == 0 ||
sh->state & handle_flags)
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
}
spin_lock_irq(&head_sh->stripe_lock);
head_sh->batch_head = NULL;
spin_unlock_irq(&head_sh->stripe_lock);
for (i = 0; i < head_sh->disks; i++)
if (test_and_clear_bit(R5_Overlap, &head_sh->dev[i].flags))
do_wakeup = 1;
if (head_sh->state & handle_flags)
set_bit(STRIPE_HANDLE, &head_sh->state);
if (do_wakeup)
wake_up(&head_sh->raid_conf->wait_for_overlap);
}
static void handle_stripe(struct stripe_head *sh)
{
struct stripe_head_state s;
struct r5conf *conf = sh->raid_conf;
int i;
int prexor;
int disks = sh->disks;
struct r5dev *pdev, *qdev;
clear_bit(STRIPE_HANDLE, &sh->state);
/*
* handle_stripe should not continue handle the batched stripe, only
* the head of batch list or lone stripe can continue. Otherwise we
* could see break_stripe_batch_list warns about the STRIPE_ACTIVE
* is set for the batched stripe.
*/
if (clear_batch_ready(sh))
return;
if (test_and_set_bit_lock(STRIPE_ACTIVE, &sh->state)) {
/* already being handled, ensure it gets handled
* again when current action finishes */
set_bit(STRIPE_HANDLE, &sh->state);
return;
}
if (test_and_clear_bit(STRIPE_BATCH_ERR, &sh->state))
break_stripe_batch_list(sh, 0);
if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state) && !sh->batch_head) {
spin_lock(&sh->stripe_lock);
/*
* Cannot process 'sync' concurrently with 'discard'.
* Flush data in r5cache before 'sync'.
*/
if (!test_bit(STRIPE_R5C_PARTIAL_STRIPE, &sh->state) &&
!test_bit(STRIPE_R5C_FULL_STRIPE, &sh->state) &&
!test_bit(STRIPE_DISCARD, &sh->state) &&
test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) {
set_bit(STRIPE_SYNCING, &sh->state);
clear_bit(STRIPE_INSYNC, &sh->state);
clear_bit(STRIPE_REPLACED, &sh->state);
}
spin_unlock(&sh->stripe_lock);
}
clear_bit(STRIPE_DELAYED, &sh->state);
pr_debug("handling stripe %llu, state=%#lx cnt=%d, "
"pd_idx=%d, qd_idx=%d\n, check:%d, reconstruct:%d\n",
(unsigned long long)sh->sector, sh->state,
atomic_read(&sh->count), sh->pd_idx, sh->qd_idx,
sh->check_state, sh->reconstruct_state);
analyse_stripe(sh, &s);
if (test_bit(STRIPE_LOG_TRAPPED, &sh->state))
goto finish;
if (s.handle_bad_blocks ||
test_bit(MD_SB_CHANGE_PENDING, &conf->mddev->sb_flags)) {
set_bit(STRIPE_HANDLE, &sh->state);
goto finish;
}
if (unlikely(s.blocked_rdev)) {
if (s.syncing || s.expanding || s.expanded ||
s.replacing || s.to_write || s.written) {
set_bit(STRIPE_HANDLE, &sh->state);
goto finish;
}
/* There is nothing for the blocked_rdev to block */
rdev_dec_pending(s.blocked_rdev, conf->mddev);
s.blocked_rdev = NULL;
}
if (s.to_fill && !test_bit(STRIPE_BIOFILL_RUN, &sh->state)) {
set_bit(STRIPE_OP_BIOFILL, &s.ops_request);
set_bit(STRIPE_BIOFILL_RUN, &sh->state);
}
pr_debug("locked=%d uptodate=%d to_read=%d"
" to_write=%d failed=%d failed_num=%d,%d\n",
s.locked, s.uptodate, s.to_read, s.to_write, s.failed,
s.failed_num[0], s.failed_num[1]);
/*
* check if the array has lost more than max_degraded devices and,
* if so, some requests might need to be failed.
*
* When journal device failed (log_failed), we will only process
* the stripe if there is data need write to raid disks
*/
if (s.failed > conf->max_degraded ||
(s.log_failed && s.injournal == 0)) {
sh->check_state = 0;
sh->reconstruct_state = 0;
break_stripe_batch_list(sh, 0);
if (s.to_read+s.to_write+s.written)
handle_failed_stripe(conf, sh, &s, disks);
if (s.syncing + s.replacing)
handle_failed_sync(conf, sh, &s);
}
/* Now we check to see if any write operations have recently
* completed
*/
prexor = 0;
if (sh->reconstruct_state == reconstruct_state_prexor_drain_result)
prexor = 1;
if (sh->reconstruct_state == reconstruct_state_drain_result ||
sh->reconstruct_state == reconstruct_state_prexor_drain_result) {
sh->reconstruct_state = reconstruct_state_idle;
/* All the 'written' buffers and the parity block are ready to
* be written back to disk
*/
BUG_ON(!test_bit(R5_UPTODATE, &sh->dev[sh->pd_idx].flags) &&
!test_bit(R5_Discard, &sh->dev[sh->pd_idx].flags));
BUG_ON(sh->qd_idx >= 0 &&
!test_bit(R5_UPTODATE, &sh->dev[sh->qd_idx].flags) &&
!test_bit(R5_Discard, &sh->dev[sh->qd_idx].flags));
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
if (test_bit(R5_LOCKED, &dev->flags) &&
(i == sh->pd_idx || i == sh->qd_idx ||
dev->written || test_bit(R5_InJournal,
&dev->flags))) {
pr_debug("Writing block %d\n", i);
set_bit(R5_Wantwrite, &dev->flags);
if (prexor)
continue;
if (s.failed > 1)
continue;
if (!test_bit(R5_Insync, &dev->flags) ||
((i == sh->pd_idx || i == sh->qd_idx) &&
s.failed == 0))
set_bit(STRIPE_INSYNC, &sh->state);
}
}
if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
s.dec_preread_active = 1;
}
/*
* might be able to return some write requests if the parity blocks
* are safe, or on a failed drive
*/
pdev = &sh->dev[sh->pd_idx];
s.p_failed = (s.failed >= 1 && s.failed_num[0] == sh->pd_idx)
|| (s.failed >= 2 && s.failed_num[1] == sh->pd_idx);
qdev = &sh->dev[sh->qd_idx];
s.q_failed = (s.failed >= 1 && s.failed_num[0] == sh->qd_idx)
|| (s.failed >= 2 && s.failed_num[1] == sh->qd_idx)
|| conf->level < 6;
if (s.written &&
(s.p_failed || ((test_bit(R5_Insync, &pdev->flags)
&& !test_bit(R5_LOCKED, &pdev->flags)
&& (test_bit(R5_UPTODATE, &pdev->flags) ||
test_bit(R5_Discard, &pdev->flags))))) &&
(s.q_failed || ((test_bit(R5_Insync, &qdev->flags)
&& !test_bit(R5_LOCKED, &qdev->flags)
&& (test_bit(R5_UPTODATE, &qdev->flags) ||
test_bit(R5_Discard, &qdev->flags))))))
handle_stripe_clean_event(conf, sh, disks);
if (s.just_cached)
r5c_handle_cached_data_endio(conf, sh, disks);
log_stripe_write_finished(sh);
/* Now we might consider reading some blocks, either to check/generate
* parity, or to satisfy requests
* or to load a block that is being partially written.
*/
if (s.to_read || s.non_overwrite
|| (s.to_write && s.failed)
|| (s.syncing && (s.uptodate + s.compute < disks))
|| s.replacing
|| s.expanding)
handle_stripe_fill(sh, &s, disks);
/*
* When the stripe finishes full journal write cycle (write to journal
* and raid disk), this is the clean up procedure so it is ready for
* next operation.
*/
r5c_finish_stripe_write_out(conf, sh, &s);
/*
* Now to consider new write requests, cache write back and what else,
* if anything should be read. We do not handle new writes when:
* 1/ A 'write' operation (copy+xor) is already in flight.
* 2/ A 'check' operation is in flight, as it may clobber the parity
* block.
* 3/ A r5c cache log write is in flight.
*/
if (!sh->reconstruct_state && !sh->check_state && !sh->log_io) {
if (!r5c_is_writeback(conf->log)) {
if (s.to_write)
handle_stripe_dirtying(conf, sh, &s, disks);
} else { /* write back cache */
int ret = 0;
/* First, try handle writes in caching phase */
if (s.to_write)
ret = r5c_try_caching_write(conf, sh, &s,
disks);
/*
* If caching phase failed: ret == -EAGAIN
* OR
* stripe under reclaim: !caching && injournal
*
* fall back to handle_stripe_dirtying()
*/
if (ret == -EAGAIN ||
/* stripe under reclaim: !caching && injournal */
(!test_bit(STRIPE_R5C_CACHING, &sh->state) &&
s.injournal > 0)) {
ret = handle_stripe_dirtying(conf, sh, &s,
disks);
if (ret == -EAGAIN)
goto finish;
}
}
}
/* maybe we need to check and possibly fix the parity for this stripe
* Any reads will already have been scheduled, so we just see if enough
* data is available. The parity check is held off while parity
* dependent operations are in flight.
*/
if (sh->check_state ||
(s.syncing && s.locked == 0 &&
!test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
!test_bit(STRIPE_INSYNC, &sh->state))) {
if (conf->level == 6)
handle_parity_checks6(conf, sh, &s, disks);
else
handle_parity_checks5(conf, sh, &s, disks);
}
if ((s.replacing || s.syncing) && s.locked == 0
&& !test_bit(STRIPE_COMPUTE_RUN, &sh->state)
&& !test_bit(STRIPE_REPLACED, &sh->state)) {
/* Write out to replacement devices where possible */
for (i = 0; i < conf->raid_disks; i++)
if (test_bit(R5_NeedReplace, &sh->dev[i].flags)) {
WARN_ON(!test_bit(R5_UPTODATE, &sh->dev[i].flags));
set_bit(R5_WantReplace, &sh->dev[i].flags);
set_bit(R5_LOCKED, &sh->dev[i].flags);
s.locked++;
}
if (s.replacing)
set_bit(STRIPE_INSYNC, &sh->state);
set_bit(STRIPE_REPLACED, &sh->state);
}
if ((s.syncing || s.replacing) && s.locked == 0 &&
!test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
test_bit(STRIPE_INSYNC, &sh->state)) {
md_done_sync(conf->mddev, RAID5_STRIPE_SECTORS(conf), 1);
clear_bit(STRIPE_SYNCING, &sh->state);
if (test_and_clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags))
wake_up(&conf->wait_for_overlap);
}
/* If the failed drives are just a ReadError, then we might need
* to progress the repair/check process
*/
if (s.failed <= conf->max_degraded && !conf->mddev->ro)
for (i = 0; i < s.failed; i++) {
struct r5dev *dev = &sh->dev[s.failed_num[i]];
if (test_bit(R5_ReadError, &dev->flags)
&& !test_bit(R5_LOCKED, &dev->flags)
&& test_bit(R5_UPTODATE, &dev->flags)
) {
if (!test_bit(R5_ReWrite, &dev->flags)) {
set_bit(R5_Wantwrite, &dev->flags);
set_bit(R5_ReWrite, &dev->flags);
} else
/* let's read it back */
set_bit(R5_Wantread, &dev->flags);
set_bit(R5_LOCKED, &dev->flags);
s.locked++;
}
}
/* Finish reconstruct operations initiated by the expansion process */
if (sh->reconstruct_state == reconstruct_state_result) {
struct stripe_head *sh_src
= raid5_get_active_stripe(conf, NULL, sh->sector,
R5_GAS_PREVIOUS | R5_GAS_NOBLOCK |
R5_GAS_NOQUIESCE);
if (sh_src && test_bit(STRIPE_EXPAND_SOURCE, &sh_src->state)) {
/* sh cannot be written until sh_src has been read.
* so arrange for sh to be delayed a little
*/
set_bit(STRIPE_DELAYED, &sh->state);
set_bit(STRIPE_HANDLE, &sh->state);
if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE,
&sh_src->state))
atomic_inc(&conf->preread_active_stripes);
raid5_release_stripe(sh_src);
goto finish;
}
if (sh_src)
raid5_release_stripe(sh_src);
sh->reconstruct_state = reconstruct_state_idle;
clear_bit(STRIPE_EXPANDING, &sh->state);
for (i = conf->raid_disks; i--; ) {
set_bit(R5_Wantwrite, &sh->dev[i].flags);
set_bit(R5_LOCKED, &sh->dev[i].flags);
s.locked++;
}
}
if (s.expanded && test_bit(STRIPE_EXPANDING, &sh->state) &&
!sh->reconstruct_state) {
/* Need to write out all blocks after computing parity */
sh->disks = conf->raid_disks;
stripe_set_idx(sh->sector, conf, 0, sh);
schedule_reconstruction(sh, &s, 1, 1);
} else if (s.expanded && !sh->reconstruct_state && s.locked == 0) {
clear_bit(STRIPE_EXPAND_READY, &sh->state);
atomic_dec(&conf->reshape_stripes);
wake_up(&conf->wait_for_overlap);
md_done_sync(conf->mddev, RAID5_STRIPE_SECTORS(conf), 1);
}
if (s.expanding && s.locked == 0 &&
!test_bit(STRIPE_COMPUTE_RUN, &sh->state))
handle_stripe_expansion(conf, sh);
finish:
/* wait for this device to become unblocked */
if (unlikely(s.blocked_rdev)) {
if (conf->mddev->external)
md_wait_for_blocked_rdev(s.blocked_rdev,
conf->mddev);
else
/* Internal metadata will immediately
* be written by raid5d, so we don't
* need to wait here.
*/
rdev_dec_pending(s.blocked_rdev,
conf->mddev);
}
if (s.handle_bad_blocks)
for (i = disks; i--; ) {
struct md_rdev *rdev;
struct r5dev *dev = &sh->dev[i];
if (test_and_clear_bit(R5_WriteError, &dev->flags)) {
/* We own a safe reference to the rdev */
rdev = rdev_pend_deref(conf->disks[i].rdev);
if (!rdev_set_badblocks(rdev, sh->sector,
RAID5_STRIPE_SECTORS(conf), 0))
md_error(conf->mddev, rdev);
rdev_dec_pending(rdev, conf->mddev);
}
if (test_and_clear_bit(R5_MadeGood, &dev->flags)) {
rdev = rdev_pend_deref(conf->disks[i].rdev);
rdev_clear_badblocks(rdev, sh->sector,
RAID5_STRIPE_SECTORS(conf), 0);
rdev_dec_pending(rdev, conf->mddev);
}
if (test_and_clear_bit(R5_MadeGoodRepl, &dev->flags)) {
rdev = rdev_pend_deref(conf->disks[i].replacement);
if (!rdev)
/* rdev have been moved down */
rdev = rdev_pend_deref(conf->disks[i].rdev);
rdev_clear_badblocks(rdev, sh->sector,
RAID5_STRIPE_SECTORS(conf), 0);
rdev_dec_pending(rdev, conf->mddev);
}
}
if (s.ops_request)
raid_run_ops(sh, s.ops_request);
ops_run_io(sh, &s);
if (s.dec_preread_active) {
/* We delay this until after ops_run_io so that if make_request
* is waiting on a flush, it won't continue until the writes
* have actually been submitted.
*/
atomic_dec(&conf->preread_active_stripes);
if (atomic_read(&conf->preread_active_stripes) <
IO_THRESHOLD)
md_wakeup_thread(conf->mddev->thread);
}
clear_bit_unlock(STRIPE_ACTIVE, &sh->state);
}
static void raid5_activate_delayed(struct r5conf *conf)
__must_hold(&conf->device_lock)
{
if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD) {
while (!list_empty(&conf->delayed_list)) {
struct list_head *l = conf->delayed_list.next;
struct stripe_head *sh;
sh = list_entry(l, struct stripe_head, lru);
list_del_init(l);
clear_bit(STRIPE_DELAYED, &sh->state);
if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
atomic_inc(&conf->preread_active_stripes);
list_add_tail(&sh->lru, &conf->hold_list);
raid5_wakeup_stripe_thread(sh);
}
}
}
static void activate_bit_delay(struct r5conf *conf,
struct list_head *temp_inactive_list)
__must_hold(&conf->device_lock)
{
struct list_head head;
list_add(&head, &conf->bitmap_list);
list_del_init(&conf->bitmap_list);
while (!list_empty(&head)) {
struct stripe_head *sh = list_entry(head.next, struct stripe_head, lru);
int hash;
list_del_init(&sh->lru);
atomic_inc(&sh->count);
hash = sh->hash_lock_index;
__release_stripe(conf, sh, &temp_inactive_list[hash]);
}
}
static int in_chunk_boundary(struct mddev *mddev, struct bio *bio)
{
struct r5conf *conf = mddev->private;
sector_t sector = bio->bi_iter.bi_sector;
unsigned int chunk_sectors;
unsigned int bio_sectors = bio_sectors(bio);
chunk_sectors = min(conf->chunk_sectors, conf->prev_chunk_sectors);
return chunk_sectors >=
((sector & (chunk_sectors - 1)) + bio_sectors);
}
/*
* add bio to the retry LIFO ( in O(1) ... we are in interrupt )
* later sampled by raid5d.
*/
static void add_bio_to_retry(struct bio *bi,struct r5conf *conf)
{
unsigned long flags;
spin_lock_irqsave(&conf->device_lock, flags);
bi->bi_next = conf->retry_read_aligned_list;
conf->retry_read_aligned_list = bi;
spin_unlock_irqrestore(&conf->device_lock, flags);
md_wakeup_thread(conf->mddev->thread);
}
static struct bio *remove_bio_from_retry(struct r5conf *conf,
unsigned int *offset)
{
struct bio *bi;
bi = conf->retry_read_aligned;
if (bi) {
*offset = conf->retry_read_offset;
conf->retry_read_aligned = NULL;
return bi;
}
bi = conf->retry_read_aligned_list;
if(bi) {
conf->retry_read_aligned_list = bi->bi_next;
bi->bi_next = NULL;
*offset = 0;
}
return bi;
}
/*
* The "raid5_align_endio" should check if the read succeeded and if it
* did, call bio_endio on the original bio (having bio_put the new bio
* first).
* If the read failed..
*/
static void raid5_align_endio(struct bio *bi)
{
struct bio *raid_bi = bi->bi_private;
struct md_rdev *rdev = (void *)raid_bi->bi_next;
struct mddev *mddev = rdev->mddev;
struct r5conf *conf = mddev->private;
blk_status_t error = bi->bi_status;
bio_put(bi);
raid_bi->bi_next = NULL;
rdev_dec_pending(rdev, conf->mddev);
if (!error) {
bio_endio(raid_bi);
if (atomic_dec_and_test(&conf->active_aligned_reads))
wake_up(&conf->wait_for_quiescent);
return;
}
pr_debug("raid5_align_endio : io error...handing IO for a retry\n");
add_bio_to_retry(raid_bi, conf);
}
static int raid5_read_one_chunk(struct mddev *mddev, struct bio *raid_bio)
{
struct r5conf *conf = mddev->private;
struct bio *align_bio;
struct md_rdev *rdev;
sector_t sector, end_sector, first_bad;
int bad_sectors, dd_idx;
bool did_inc;
if (!in_chunk_boundary(mddev, raid_bio)) {
pr_debug("%s: non aligned\n", __func__);
return 0;
}
sector = raid5_compute_sector(conf, raid_bio->bi_iter.bi_sector, 0,
&dd_idx, NULL);
end_sector = sector + bio_sectors(raid_bio);
rcu_read_lock();
if (r5c_big_stripe_cached(conf, sector))
goto out_rcu_unlock;
rdev = rcu_dereference(conf->disks[dd_idx].replacement);
if (!rdev || test_bit(Faulty, &rdev->flags) ||
rdev->recovery_offset < end_sector) {
rdev = rcu_dereference(conf->disks[dd_idx].rdev);
if (!rdev)
goto out_rcu_unlock;
if (test_bit(Faulty, &rdev->flags) ||
!(test_bit(In_sync, &rdev->flags) ||
rdev->recovery_offset >= end_sector))
goto out_rcu_unlock;
}
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
if (is_badblock(rdev, sector, bio_sectors(raid_bio), &first_bad,
&bad_sectors)) {
rdev_dec_pending(rdev, mddev);
return 0;
}
md_account_bio(mddev, &raid_bio);
raid_bio->bi_next = (void *)rdev;
align_bio = bio_alloc_clone(rdev->bdev, raid_bio, GFP_NOIO,
&mddev->bio_set);
align_bio->bi_end_io = raid5_align_endio;
align_bio->bi_private = raid_bio;
align_bio->bi_iter.bi_sector = sector;
/* No reshape active, so we can trust rdev->data_offset */
align_bio->bi_iter.bi_sector += rdev->data_offset;
did_inc = false;
if (conf->quiesce == 0) {
atomic_inc(&conf->active_aligned_reads);
did_inc = true;
}
/* need a memory barrier to detect the race with raid5_quiesce() */
if (!did_inc || smp_load_acquire(&conf->quiesce) != 0) {
/* quiesce is in progress, so we need to undo io activation and wait
* for it to finish
*/
if (did_inc && atomic_dec_and_test(&conf->active_aligned_reads))
wake_up(&conf->wait_for_quiescent);
spin_lock_irq(&conf->device_lock);
wait_event_lock_irq(conf->wait_for_quiescent, conf->quiesce == 0,
conf->device_lock);
atomic_inc(&conf->active_aligned_reads);
spin_unlock_irq(&conf->device_lock);
}
if (mddev->gendisk)
trace_block_bio_remap(align_bio, disk_devt(mddev->gendisk),
raid_bio->bi_iter.bi_sector);
submit_bio_noacct(align_bio);
return 1;
out_rcu_unlock:
rcu_read_unlock();
return 0;
}
static struct bio *chunk_aligned_read(struct mddev *mddev, struct bio *raid_bio)
{
struct bio *split;
sector_t sector = raid_bio->bi_iter.bi_sector;
unsigned chunk_sects = mddev->chunk_sectors;
unsigned sectors = chunk_sects - (sector & (chunk_sects-1));
if (sectors < bio_sectors(raid_bio)) {
struct r5conf *conf = mddev->private;
split = bio_split(raid_bio, sectors, GFP_NOIO, &conf->bio_split);
bio_chain(split, raid_bio);
submit_bio_noacct(raid_bio);
raid_bio = split;
}
if (!raid5_read_one_chunk(mddev, raid_bio))
return raid_bio;
return NULL;
}
/* __get_priority_stripe - get the next stripe to process
*
* Full stripe writes are allowed to pass preread active stripes up until
* the bypass_threshold is exceeded. In general the bypass_count
* increments when the handle_list is handled before the hold_list; however, it
* will not be incremented when STRIPE_IO_STARTED is sampled set signifying a
* stripe with in flight i/o. The bypass_count will be reset when the
* head of the hold_list has changed, i.e. the head was promoted to the
* handle_list.
*/
static struct stripe_head *__get_priority_stripe(struct r5conf *conf, int group)
__must_hold(&conf->device_lock)
{
struct stripe_head *sh, *tmp;
struct list_head *handle_list = NULL;
struct r5worker_group *wg;
bool second_try = !r5c_is_writeback(conf->log) &&
!r5l_log_disk_error(conf);
bool try_loprio = test_bit(R5C_LOG_TIGHT, &conf->cache_state) ||
r5l_log_disk_error(conf);
again:
wg = NULL;
sh = NULL;
if (conf->worker_cnt_per_group == 0) {
handle_list = try_loprio ? &conf->loprio_list :
&conf->handle_list;
} else if (group != ANY_GROUP) {
handle_list = try_loprio ? &conf->worker_groups[group].loprio_list :
&conf->worker_groups[group].handle_list;
wg = &conf->worker_groups[group];
} else {
int i;
for (i = 0; i < conf->group_cnt; i++) {
handle_list = try_loprio ? &conf->worker_groups[i].loprio_list :
&conf->worker_groups[i].handle_list;
wg = &conf->worker_groups[i];
if (!list_empty(handle_list))
break;
}
}
pr_debug("%s: handle: %s hold: %s full_writes: %d bypass_count: %d\n",
__func__,
list_empty(handle_list) ? "empty" : "busy",
list_empty(&conf->hold_list) ? "empty" : "busy",
atomic_read(&conf->pending_full_writes), conf->bypass_count);
if (!list_empty(handle_list)) {
sh = list_entry(handle_list->next, typeof(*sh), lru);
if (list_empty(&conf->hold_list))
conf->bypass_count = 0;
else if (!test_bit(STRIPE_IO_STARTED, &sh->state)) {
if (conf->hold_list.next == conf->last_hold)
conf->bypass_count++;
else {
conf->last_hold = conf->hold_list.next;
conf->bypass_count -= conf->bypass_threshold;
if (conf->bypass_count < 0)
conf->bypass_count = 0;
}
}
} else if (!list_empty(&conf->hold_list) &&
((conf->bypass_threshold &&
conf->bypass_count > conf->bypass_threshold) ||
atomic_read(&conf->pending_full_writes) == 0)) {
list_for_each_entry(tmp, &conf->hold_list, lru) {
if (conf->worker_cnt_per_group == 0 ||
group == ANY_GROUP ||
!cpu_online(tmp->cpu) ||
cpu_to_group(tmp->cpu) == group) {
sh = tmp;
break;
}
}
if (sh) {
conf->bypass_count -= conf->bypass_threshold;
if (conf->bypass_count < 0)
conf->bypass_count = 0;
}
wg = NULL;
}
if (!sh) {
if (second_try)
return NULL;
second_try = true;
try_loprio = !try_loprio;
goto again;
}
if (wg) {
wg->stripes_cnt--;
sh->group = NULL;
}
list_del_init(&sh->lru);
BUG_ON(atomic_inc_return(&sh->count) != 1);
return sh;
}
struct raid5_plug_cb {
struct blk_plug_cb cb;
struct list_head list;
struct list_head temp_inactive_list[NR_STRIPE_HASH_LOCKS];
};
static void raid5_unplug(struct blk_plug_cb *blk_cb, bool from_schedule)
{
struct raid5_plug_cb *cb = container_of(
blk_cb, struct raid5_plug_cb, cb);
struct stripe_head *sh;
struct mddev *mddev = cb->cb.data;
struct r5conf *conf = mddev->private;
int cnt = 0;
int hash;
if (cb->list.next && !list_empty(&cb->list)) {
spin_lock_irq(&conf->device_lock);
while (!list_empty(&cb->list)) {
sh = list_first_entry(&cb->list, struct stripe_head, lru);
list_del_init(&sh->lru);
/*
* avoid race release_stripe_plug() sees
* STRIPE_ON_UNPLUG_LIST clear but the stripe
* is still in our list
*/
smp_mb__before_atomic();
clear_bit(STRIPE_ON_UNPLUG_LIST, &sh->state);
/*
* STRIPE_ON_RELEASE_LIST could be set here. In that
* case, the count is always > 1 here
*/
hash = sh->hash_lock_index;
__release_stripe(conf, sh, &cb->temp_inactive_list[hash]);
cnt++;
}
spin_unlock_irq(&conf->device_lock);
}
release_inactive_stripe_list(conf, cb->temp_inactive_list,
NR_STRIPE_HASH_LOCKS);
if (mddev->queue)
trace_block_unplug(mddev->queue, cnt, !from_schedule);
kfree(cb);
}
static void release_stripe_plug(struct mddev *mddev,
struct stripe_head *sh)
{
struct blk_plug_cb *blk_cb = blk_check_plugged(
raid5_unplug, mddev,
sizeof(struct raid5_plug_cb));
struct raid5_plug_cb *cb;
if (!blk_cb) {
raid5_release_stripe(sh);
return;
}
cb = container_of(blk_cb, struct raid5_plug_cb, cb);
if (cb->list.next == NULL) {
int i;
INIT_LIST_HEAD(&cb->list);
for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
INIT_LIST_HEAD(cb->temp_inactive_list + i);
}
if (!test_and_set_bit(STRIPE_ON_UNPLUG_LIST, &sh->state))
list_add_tail(&sh->lru, &cb->list);
else
raid5_release_stripe(sh);
}
static void make_discard_request(struct mddev *mddev, struct bio *bi)
{
struct r5conf *conf = mddev->private;
sector_t logical_sector, last_sector;
struct stripe_head *sh;
int stripe_sectors;
/* We need to handle this when io_uring supports discard/trim */
if (WARN_ON_ONCE(bi->bi_opf & REQ_NOWAIT))
return;
if (mddev->reshape_position != MaxSector)
/* Skip discard while reshape is happening */
return;
logical_sector = bi->bi_iter.bi_sector & ~((sector_t)RAID5_STRIPE_SECTORS(conf)-1);
last_sector = bio_end_sector(bi);
bi->bi_next = NULL;
stripe_sectors = conf->chunk_sectors *
(conf->raid_disks - conf->max_degraded);
logical_sector = DIV_ROUND_UP_SECTOR_T(logical_sector,
stripe_sectors);
sector_div(last_sector, stripe_sectors);
logical_sector *= conf->chunk_sectors;
last_sector *= conf->chunk_sectors;
for (; logical_sector < last_sector;
logical_sector += RAID5_STRIPE_SECTORS(conf)) {
DEFINE_WAIT(w);
int d;
again:
sh = raid5_get_active_stripe(conf, NULL, logical_sector, 0);
prepare_to_wait(&conf->wait_for_overlap, &w,
TASK_UNINTERRUPTIBLE);
set_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags);
if (test_bit(STRIPE_SYNCING, &sh->state)) {
raid5_release_stripe(sh);
schedule();
goto again;
}
clear_bit(R5_Overlap, &sh->dev[sh->pd_idx].flags);
spin_lock_irq(&sh->stripe_lock);
for (d = 0; d < conf->raid_disks; d++) {
if (d == sh->pd_idx || d == sh->qd_idx)
continue;
if (sh->dev[d].towrite || sh->dev[d].toread) {
set_bit(R5_Overlap, &sh->dev[d].flags);
spin_unlock_irq(&sh->stripe_lock);
raid5_release_stripe(sh);
schedule();
goto again;
}
}
set_bit(STRIPE_DISCARD, &sh->state);
finish_wait(&conf->wait_for_overlap, &w);
sh->overwrite_disks = 0;
for (d = 0; d < conf->raid_disks; d++) {
if (d == sh->pd_idx || d == sh->qd_idx)
continue;
sh->dev[d].towrite = bi;
set_bit(R5_OVERWRITE, &sh->dev[d].flags);
bio_inc_remaining(bi);
md_write_inc(mddev, bi);
sh->overwrite_disks++;
}
spin_unlock_irq(&sh->stripe_lock);
if (conf->mddev->bitmap) {
for (d = 0;
d < conf->raid_disks - conf->max_degraded;
d++)
md_bitmap_startwrite(mddev->bitmap,
sh->sector,
RAID5_STRIPE_SECTORS(conf),
0);
sh->bm_seq = conf->seq_flush + 1;
set_bit(STRIPE_BIT_DELAY, &sh->state);
}
set_bit(STRIPE_HANDLE, &sh->state);
clear_bit(STRIPE_DELAYED, &sh->state);
if (!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
atomic_inc(&conf->preread_active_stripes);
release_stripe_plug(mddev, sh);
}
bio_endio(bi);
}
static bool ahead_of_reshape(struct mddev *mddev, sector_t sector,
sector_t reshape_sector)
{
return mddev->reshape_backwards ? sector < reshape_sector :
sector >= reshape_sector;
}
static bool range_ahead_of_reshape(struct mddev *mddev, sector_t min,
sector_t max, sector_t reshape_sector)
{
return mddev->reshape_backwards ? max < reshape_sector :
min >= reshape_sector;
}
static bool stripe_ahead_of_reshape(struct mddev *mddev, struct r5conf *conf,
struct stripe_head *sh)
{
sector_t max_sector = 0, min_sector = MaxSector;
bool ret = false;
int dd_idx;
for (dd_idx = 0; dd_idx < sh->disks; dd_idx++) {
if (dd_idx == sh->pd_idx)
continue;
min_sector = min(min_sector, sh->dev[dd_idx].sector);
max_sector = min(max_sector, sh->dev[dd_idx].sector);
}
spin_lock_irq(&conf->device_lock);
if (!range_ahead_of_reshape(mddev, min_sector, max_sector,
conf->reshape_progress))
/* mismatch, need to try again */
ret = true;
spin_unlock_irq(&conf->device_lock);
return ret;
}
static int add_all_stripe_bios(struct r5conf *conf,
struct stripe_request_ctx *ctx, struct stripe_head *sh,
struct bio *bi, int forwrite, int previous)
{
int dd_idx;
int ret = 1;
spin_lock_irq(&sh->stripe_lock);
for (dd_idx = 0; dd_idx < sh->disks; dd_idx++) {
struct r5dev *dev = &sh->dev[dd_idx];
if (dd_idx == sh->pd_idx || dd_idx == sh->qd_idx)
continue;
if (dev->sector < ctx->first_sector ||
dev->sector >= ctx->last_sector)
continue;
if (stripe_bio_overlaps(sh, bi, dd_idx, forwrite)) {
set_bit(R5_Overlap, &dev->flags);
ret = 0;
continue;
}
}
if (!ret)
goto out;
for (dd_idx = 0; dd_idx < sh->disks; dd_idx++) {
struct r5dev *dev = &sh->dev[dd_idx];
if (dd_idx == sh->pd_idx || dd_idx == sh->qd_idx)
continue;
if (dev->sector < ctx->first_sector ||
dev->sector >= ctx->last_sector)
continue;
__add_stripe_bio(sh, bi, dd_idx, forwrite, previous);
clear_bit((dev->sector - ctx->first_sector) >>
RAID5_STRIPE_SHIFT(conf), ctx->sectors_to_do);
}
out:
spin_unlock_irq(&sh->stripe_lock);
return ret;
}
static bool reshape_inprogress(struct mddev *mddev)
{
return test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
!test_bit(MD_RECOVERY_DONE, &mddev->recovery) &&
!test_bit(MD_RECOVERY_INTR, &mddev->recovery);
}
static bool reshape_disabled(struct mddev *mddev)
{
return is_md_suspended(mddev) || !md_is_rdwr(mddev);
}
static enum stripe_result make_stripe_request(struct mddev *mddev,
struct r5conf *conf, struct stripe_request_ctx *ctx,
sector_t logical_sector, struct bio *bi)
{
const int rw = bio_data_dir(bi);
enum stripe_result ret;
struct stripe_head *sh;
sector_t new_sector;
int previous = 0, flags = 0;
int seq, dd_idx;
seq = read_seqcount_begin(&conf->gen_lock);
if (unlikely(conf->reshape_progress != MaxSector)) {
/*
* Spinlock is needed as reshape_progress may be
* 64bit on a 32bit platform, and so it might be
* possible to see a half-updated value
* Of course reshape_progress could change after
* the lock is dropped, so once we get a reference
* to the stripe that we think it is, we will have
* to check again.
*/
spin_lock_irq(&conf->device_lock);
if (ahead_of_reshape(mddev, logical_sector,
conf->reshape_progress)) {
previous = 1;
} else {
if (ahead_of_reshape(mddev, logical_sector,
conf->reshape_safe)) {
spin_unlock_irq(&conf->device_lock);
ret = STRIPE_SCHEDULE_AND_RETRY;
goto out;
}
}
spin_unlock_irq(&conf->device_lock);
}
new_sector = raid5_compute_sector(conf, logical_sector, previous,
&dd_idx, NULL);
pr_debug("raid456: %s, sector %llu logical %llu\n", __func__,
new_sector, logical_sector);
if (previous)
flags |= R5_GAS_PREVIOUS;
if (bi->bi_opf & REQ_RAHEAD)
flags |= R5_GAS_NOBLOCK;
sh = raid5_get_active_stripe(conf, ctx, new_sector, flags);
if (unlikely(!sh)) {
/* cannot get stripe, just give-up */
bi->bi_status = BLK_STS_IOERR;
return STRIPE_FAIL;
}
if (unlikely(previous) &&
stripe_ahead_of_reshape(mddev, conf, sh)) {
/*
* Expansion moved on while waiting for a stripe.
* Expansion could still move past after this
* test, but as we are holding a reference to
* 'sh', we know that if that happens,
* STRIPE_EXPANDING will get set and the expansion
* won't proceed until we finish with the stripe.
*/
ret = STRIPE_SCHEDULE_AND_RETRY;
goto out_release;
}
if (read_seqcount_retry(&conf->gen_lock, seq)) {
/* Might have got the wrong stripe_head by accident */
ret = STRIPE_RETRY;
goto out_release;
}
if (test_bit(STRIPE_EXPANDING, &sh->state) ||
!add_all_stripe_bios(conf, ctx, sh, bi, rw, previous)) {
/*
* Stripe is busy expanding or add failed due to
* overlap. Flush everything and wait a while.
*/
md_wakeup_thread(mddev->thread);
ret = STRIPE_SCHEDULE_AND_RETRY;
goto out_release;
}
if (stripe_can_batch(sh)) {
stripe_add_to_batch_list(conf, sh, ctx->batch_last);
if (ctx->batch_last)
raid5_release_stripe(ctx->batch_last);
atomic_inc(&sh->count);
ctx->batch_last = sh;
}
if (ctx->do_flush) {
set_bit(STRIPE_R5C_PREFLUSH, &sh->state);
/* we only need flush for one stripe */
ctx->do_flush = false;
}
set_bit(STRIPE_HANDLE, &sh->state);
clear_bit(STRIPE_DELAYED, &sh->state);
if ((!sh->batch_head || sh == sh->batch_head) &&
(bi->bi_opf & REQ_SYNC) &&
!test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
atomic_inc(&conf->preread_active_stripes);
release_stripe_plug(mddev, sh);
return STRIPE_SUCCESS;
out_release:
raid5_release_stripe(sh);
out:
if (ret == STRIPE_SCHEDULE_AND_RETRY && !reshape_inprogress(mddev) &&
reshape_disabled(mddev)) {
bi->bi_status = BLK_STS_IOERR;
ret = STRIPE_FAIL;
pr_err("md/raid456:%s: io failed across reshape position while reshape can't make progress.\n",
mdname(mddev));
}
return ret;
}
/*
* If the bio covers multiple data disks, find sector within the bio that has
* the lowest chunk offset in the first chunk.
*/
static sector_t raid5_bio_lowest_chunk_sector(struct r5conf *conf,
struct bio *bi)
{
int sectors_per_chunk = conf->chunk_sectors;
int raid_disks = conf->raid_disks;
int dd_idx;
struct stripe_head sh;
unsigned int chunk_offset;
sector_t r_sector = bi->bi_iter.bi_sector & ~((sector_t)RAID5_STRIPE_SECTORS(conf)-1);
sector_t sector;
/* We pass in fake stripe_head to get back parity disk numbers */
sector = raid5_compute_sector(conf, r_sector, 0, &dd_idx, &sh);
chunk_offset = sector_div(sector, sectors_per_chunk);
if (sectors_per_chunk - chunk_offset >= bio_sectors(bi))
return r_sector;
/*
* Bio crosses to the next data disk. Check whether it's in the same
* chunk.
*/
dd_idx++;
while (dd_idx == sh.pd_idx || dd_idx == sh.qd_idx)
dd_idx++;
if (dd_idx >= raid_disks)
return r_sector;
return r_sector + sectors_per_chunk - chunk_offset;
}
static bool raid5_make_request(struct mddev *mddev, struct bio * bi)
{
DEFINE_WAIT_FUNC(wait, woken_wake_function);
struct r5conf *conf = mddev->private;
sector_t logical_sector;
struct stripe_request_ctx ctx = {};
const int rw = bio_data_dir(bi);
enum stripe_result res;
int s, stripe_cnt;
if (unlikely(bi->bi_opf & REQ_PREFLUSH)) {
int ret = log_handle_flush_request(conf, bi);
if (ret == 0)
return true;
if (ret == -ENODEV) {
if (md_flush_request(mddev, bi))
return true;
}
/* ret == -EAGAIN, fallback */
/*
* if r5l_handle_flush_request() didn't clear REQ_PREFLUSH,
* we need to flush journal device
*/
ctx.do_flush = bi->bi_opf & REQ_PREFLUSH;
}
if (!md_write_start(mddev, bi))
return false;
/*
* If array is degraded, better not do chunk aligned read because
* later we might have to read it again in order to reconstruct
* data on failed drives.
*/
if (rw == READ && mddev->degraded == 0 &&
mddev->reshape_position == MaxSector) {
bi = chunk_aligned_read(mddev, bi);
if (!bi)
return true;
}
if (unlikely(bio_op(bi) == REQ_OP_DISCARD)) {
make_discard_request(mddev, bi);
md_write_end(mddev);
return true;
}
logical_sector = bi->bi_iter.bi_sector & ~((sector_t)RAID5_STRIPE_SECTORS(conf)-1);
ctx.first_sector = logical_sector;
ctx.last_sector = bio_end_sector(bi);
bi->bi_next = NULL;
stripe_cnt = DIV_ROUND_UP_SECTOR_T(ctx.last_sector - logical_sector,
RAID5_STRIPE_SECTORS(conf));
bitmap_set(ctx.sectors_to_do, 0, stripe_cnt);
pr_debug("raid456: %s, logical %llu to %llu\n", __func__,
bi->bi_iter.bi_sector, ctx.last_sector);
/* Bail out if conflicts with reshape and REQ_NOWAIT is set */
if ((bi->bi_opf & REQ_NOWAIT) &&
(conf->reshape_progress != MaxSector) &&
!ahead_of_reshape(mddev, logical_sector, conf->reshape_progress) &&
ahead_of_reshape(mddev, logical_sector, conf->reshape_safe)) {
bio_wouldblock_error(bi);
if (rw == WRITE)
md_write_end(mddev);
return true;
}
md_account_bio(mddev, &bi);
/*
* Lets start with the stripe with the lowest chunk offset in the first
* chunk. That has the best chances of creating IOs adjacent to
* previous IOs in case of sequential IO and thus creates the most
* sequential IO pattern. We don't bother with the optimization when
* reshaping as the performance benefit is not worth the complexity.
*/
if (likely(conf->reshape_progress == MaxSector))
logical_sector = raid5_bio_lowest_chunk_sector(conf, bi);
s = (logical_sector - ctx.first_sector) >> RAID5_STRIPE_SHIFT(conf);
add_wait_queue(&conf->wait_for_overlap, &wait);
while (1) {
res = make_stripe_request(mddev, conf, &ctx, logical_sector,
bi);
if (res == STRIPE_FAIL)
break;
if (res == STRIPE_RETRY)
continue;
if (res == STRIPE_SCHEDULE_AND_RETRY) {
/*
* Must release the reference to batch_last before
* scheduling and waiting for work to be done,
* otherwise the batch_last stripe head could prevent
* raid5_activate_delayed() from making progress
* and thus deadlocking.
*/
if (ctx.batch_last) {
raid5_release_stripe(ctx.batch_last);
ctx.batch_last = NULL;
}
wait_woken(&wait, TASK_UNINTERRUPTIBLE,
MAX_SCHEDULE_TIMEOUT);
continue;
}
s = find_next_bit_wrap(ctx.sectors_to_do, stripe_cnt, s);
if (s == stripe_cnt)
break;
logical_sector = ctx.first_sector +
(s << RAID5_STRIPE_SHIFT(conf));
}
remove_wait_queue(&conf->wait_for_overlap, &wait);
if (ctx.batch_last)
raid5_release_stripe(ctx.batch_last);
if (rw == WRITE)
md_write_end(mddev);
bio_endio(bi);
return true;
}
static sector_t raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks);
static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, int *skipped)
{
/* reshaping is quite different to recovery/resync so it is
* handled quite separately ... here.
*
* On each call to sync_request, we gather one chunk worth of
* destination stripes and flag them as expanding.
* Then we find all the source stripes and request reads.
* As the reads complete, handle_stripe will copy the data
* into the destination stripe and release that stripe.
*/
struct r5conf *conf = mddev->private;
struct stripe_head *sh;
struct md_rdev *rdev;
sector_t first_sector, last_sector;
int raid_disks = conf->previous_raid_disks;
int data_disks = raid_disks - conf->max_degraded;
int new_data_disks = conf->raid_disks - conf->max_degraded;
int i;
int dd_idx;
sector_t writepos, readpos, safepos;
sector_t stripe_addr;
int reshape_sectors;
struct list_head stripes;
sector_t retn;
if (sector_nr == 0) {
/* If restarting in the middle, skip the initial sectors */
if (mddev->reshape_backwards &&
conf->reshape_progress < raid5_size(mddev, 0, 0)) {
sector_nr = raid5_size(mddev, 0, 0)
- conf->reshape_progress;
} else if (mddev->reshape_backwards &&
conf->reshape_progress == MaxSector) {
/* shouldn't happen, but just in case, finish up.*/
sector_nr = MaxSector;
} else if (!mddev->reshape_backwards &&
conf->reshape_progress > 0)
sector_nr = conf->reshape_progress;
sector_div(sector_nr, new_data_disks);
if (sector_nr) {
mddev->curr_resync_completed = sector_nr;
sysfs_notify_dirent_safe(mddev->sysfs_completed);
*skipped = 1;
retn = sector_nr;
goto finish;
}
}
/* We need to process a full chunk at a time.
* If old and new chunk sizes differ, we need to process the
* largest of these
*/
reshape_sectors = max(conf->chunk_sectors, conf->prev_chunk_sectors);
/* We update the metadata at least every 10 seconds, or when
* the data about to be copied would over-write the source of
* the data at the front of the range. i.e. one new_stripe
* along from reshape_progress new_maps to after where
* reshape_safe old_maps to
*/
writepos = conf->reshape_progress;
sector_div(writepos, new_data_disks);
readpos = conf->reshape_progress;
sector_div(readpos, data_disks);
safepos = conf->reshape_safe;
sector_div(safepos, data_disks);
if (mddev->reshape_backwards) {
BUG_ON(writepos < reshape_sectors);
writepos -= reshape_sectors;
readpos += reshape_sectors;
safepos += reshape_sectors;
} else {
writepos += reshape_sectors;
/* readpos and safepos are worst-case calculations.
* A negative number is overly pessimistic, and causes
* obvious problems for unsigned storage. So clip to 0.
*/
readpos -= min_t(sector_t, reshape_sectors, readpos);
safepos -= min_t(sector_t, reshape_sectors, safepos);
}
/* Having calculated the 'writepos' possibly use it
* to set 'stripe_addr' which is where we will write to.
*/
if (mddev->reshape_backwards) {
BUG_ON(conf->reshape_progress == 0);
stripe_addr = writepos;
BUG_ON((mddev->dev_sectors &
~((sector_t)reshape_sectors - 1))
- reshape_sectors - stripe_addr
!= sector_nr);
} else {
BUG_ON(writepos != sector_nr + reshape_sectors);
stripe_addr = sector_nr;
}
/* 'writepos' is the most advanced device address we might write.
* 'readpos' is the least advanced device address we might read.
* 'safepos' is the least address recorded in the metadata as having
* been reshaped.
* If there is a min_offset_diff, these are adjusted either by
* increasing the safepos/readpos if diff is negative, or
* increasing writepos if diff is positive.
* If 'readpos' is then behind 'writepos', there is no way that we can
* ensure safety in the face of a crash - that must be done by userspace
* making a backup of the data. So in that case there is no particular
* rush to update metadata.
* Otherwise if 'safepos' is behind 'writepos', then we really need to
* update the metadata to advance 'safepos' to match 'readpos' so that
* we can be safe in the event of a crash.
* So we insist on updating metadata if safepos is behind writepos and
* readpos is beyond writepos.
* In any case, update the metadata every 10 seconds.
* Maybe that number should be configurable, but I'm not sure it is
* worth it.... maybe it could be a multiple of safemode_delay???
*/
if (conf->min_offset_diff < 0) {
safepos += -conf->min_offset_diff;
readpos += -conf->min_offset_diff;
} else
writepos += conf->min_offset_diff;
if ((mddev->reshape_backwards
? (safepos > writepos && readpos < writepos)
: (safepos < writepos && readpos > writepos)) ||
time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
/* Cannot proceed until we've updated the superblock... */
wait_event(conf->wait_for_overlap,
atomic_read(&conf->reshape_stripes)==0
|| test_bit(MD_RECOVERY_INTR, &mddev->recovery));
if (atomic_read(&conf->reshape_stripes) != 0)
return 0;
mddev->reshape_position = conf->reshape_progress;
mddev->curr_resync_completed = sector_nr;
if (!mddev->reshape_backwards)
/* Can update recovery_offset */
rdev_for_each(rdev, mddev)
if (rdev->raid_disk >= 0 &&
!test_bit(Journal, &rdev->flags) &&
!test_bit(In_sync, &rdev->flags) &&
rdev->recovery_offset < sector_nr)
rdev->recovery_offset = sector_nr;
conf->reshape_checkpoint = jiffies;
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
md_wakeup_thread(mddev->thread);
wait_event(mddev->sb_wait, mddev->sb_flags == 0 ||
test_bit(MD_RECOVERY_INTR, &mddev->recovery));
if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
return 0;
spin_lock_irq(&conf->device_lock);
conf->reshape_safe = mddev->reshape_position;
spin_unlock_irq(&conf->device_lock);
wake_up(&conf->wait_for_overlap);
sysfs_notify_dirent_safe(mddev->sysfs_completed);
}
INIT_LIST_HEAD(&stripes);
for (i = 0; i < reshape_sectors; i += RAID5_STRIPE_SECTORS(conf)) {
int j;
int skipped_disk = 0;
sh = raid5_get_active_stripe(conf, NULL, stripe_addr+i,
R5_GAS_NOQUIESCE);
set_bit(STRIPE_EXPANDING, &sh->state);
atomic_inc(&conf->reshape_stripes);
/* If any of this stripe is beyond the end of the old
* array, then we need to zero those blocks
*/
for (j=sh->disks; j--;) {
sector_t s;
if (j == sh->pd_idx)
continue;
if (conf->level == 6 &&
j == sh->qd_idx)
continue;
s = raid5_compute_blocknr(sh, j, 0);
if (s < raid5_size(mddev, 0, 0)) {
skipped_disk = 1;
continue;
}
memset(page_address(sh->dev[j].page), 0, RAID5_STRIPE_SIZE(conf));
set_bit(R5_Expanded, &sh->dev[j].flags);
set_bit(R5_UPTODATE, &sh->dev[j].flags);
}
if (!skipped_disk) {
set_bit(STRIPE_EXPAND_READY, &sh->state);
set_bit(STRIPE_HANDLE, &sh->state);
}
list_add(&sh->lru, &stripes);
}
spin_lock_irq(&conf->device_lock);
if (mddev->reshape_backwards)
conf->reshape_progress -= reshape_sectors * new_data_disks;
else
conf->reshape_progress += reshape_sectors * new_data_disks;
spin_unlock_irq(&conf->device_lock);
/* Ok, those stripe are ready. We can start scheduling
* reads on the source stripes.
* The source stripes are determined by mapping the first and last
* block on the destination stripes.
*/
first_sector =
raid5_compute_sector(conf, stripe_addr*(new_data_disks),
1, &dd_idx, NULL);
last_sector =
raid5_compute_sector(conf, ((stripe_addr+reshape_sectors)
* new_data_disks - 1),
1, &dd_idx, NULL);
if (last_sector >= mddev->dev_sectors)
last_sector = mddev->dev_sectors - 1;
while (first_sector <= last_sector) {
sh = raid5_get_active_stripe(conf, NULL, first_sector,
R5_GAS_PREVIOUS | R5_GAS_NOQUIESCE);
set_bit(STRIPE_EXPAND_SOURCE, &sh->state);
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
first_sector += RAID5_STRIPE_SECTORS(conf);
}
/* Now that the sources are clearly marked, we can release
* the destination stripes
*/
while (!list_empty(&stripes)) {
sh = list_entry(stripes.next, struct stripe_head, lru);
list_del_init(&sh->lru);
raid5_release_stripe(sh);
}
/* If this takes us to the resync_max point where we have to pause,
* then we need to write out the superblock.
*/
sector_nr += reshape_sectors;
retn = reshape_sectors;
finish:
if (mddev->curr_resync_completed > mddev->resync_max ||
(sector_nr - mddev->curr_resync_completed) * 2
>= mddev->resync_max - mddev->curr_resync_completed) {
/* Cannot proceed until we've updated the superblock... */
wait_event(conf->wait_for_overlap,
atomic_read(&conf->reshape_stripes) == 0
|| test_bit(MD_RECOVERY_INTR, &mddev->recovery));
if (atomic_read(&conf->reshape_stripes) != 0)
goto ret;
mddev->reshape_position = conf->reshape_progress;
mddev->curr_resync_completed = sector_nr;
if (!mddev->reshape_backwards)
/* Can update recovery_offset */
rdev_for_each(rdev, mddev)
if (rdev->raid_disk >= 0 &&
!test_bit(Journal, &rdev->flags) &&
!test_bit(In_sync, &rdev->flags) &&
rdev->recovery_offset < sector_nr)
rdev->recovery_offset = sector_nr;
conf->reshape_checkpoint = jiffies;
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
md_wakeup_thread(mddev->thread);
wait_event(mddev->sb_wait,
!test_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags)
|| test_bit(MD_RECOVERY_INTR, &mddev->recovery));
if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
goto ret;
spin_lock_irq(&conf->device_lock);
conf->reshape_safe = mddev->reshape_position;
spin_unlock_irq(&conf->device_lock);
wake_up(&conf->wait_for_overlap);
sysfs_notify_dirent_safe(mddev->sysfs_completed);
}
ret:
return retn;
}
static inline sector_t raid5_sync_request(struct mddev *mddev, sector_t sector_nr,
int *skipped)
{
struct r5conf *conf = mddev->private;
struct stripe_head *sh;
sector_t max_sector = mddev->dev_sectors;
sector_t sync_blocks;
int still_degraded = 0;
int i;
if (sector_nr >= max_sector) {
/* just being told to finish up .. nothing much to do */
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
end_reshape(conf);
return 0;
}
if (mddev->curr_resync < max_sector) /* aborted */
md_bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
&sync_blocks, 1);
else /* completed sync */
conf->fullsync = 0;
md_bitmap_close_sync(mddev->bitmap);
return 0;
}
/* Allow raid5_quiesce to complete */
wait_event(conf->wait_for_overlap, conf->quiesce != 2);
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
return reshape_request(mddev, sector_nr, skipped);
/* No need to check resync_max as we never do more than one
* stripe, and as resync_max will always be on a chunk boundary,
* if the check in md_do_sync didn't fire, there is no chance
* of overstepping resync_max here
*/
/* if there is too many failed drives and we are trying
* to resync, then assert that we are finished, because there is
* nothing we can do.
*/
if (mddev->degraded >= conf->max_degraded &&
test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
sector_t rv = mddev->dev_sectors - sector_nr;
*skipped = 1;
return rv;
}
if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
!conf->fullsync &&
!md_bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
sync_blocks >= RAID5_STRIPE_SECTORS(conf)) {
/* we can skip this block, and probably more */
do_div(sync_blocks, RAID5_STRIPE_SECTORS(conf));
*skipped = 1;
/* keep things rounded to whole stripes */
return sync_blocks * RAID5_STRIPE_SECTORS(conf);
}
md_bitmap_cond_end_sync(mddev->bitmap, sector_nr, false);
sh = raid5_get_active_stripe(conf, NULL, sector_nr,
R5_GAS_NOBLOCK);
if (sh == NULL) {
sh = raid5_get_active_stripe(conf, NULL, sector_nr, 0);
/* make sure we don't swamp the stripe cache if someone else
* is trying to get access
*/
schedule_timeout_uninterruptible(1);
}
/* Need to check if array will still be degraded after recovery/resync
* Note in case of > 1 drive failures it's possible we're rebuilding
* one drive while leaving another faulty drive in array.
*/
rcu_read_lock();
for (i = 0; i < conf->raid_disks; i++) {
struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);
if (rdev == NULL || test_bit(Faulty, &rdev->flags))
still_degraded = 1;
}
rcu_read_unlock();
md_bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded);
set_bit(STRIPE_SYNC_REQUESTED, &sh->state);
set_bit(STRIPE_HANDLE, &sh->state);
raid5_release_stripe(sh);
return RAID5_STRIPE_SECTORS(conf);
}
static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio,
unsigned int offset)
{
/* We may not be able to submit a whole bio at once as there
* may not be enough stripe_heads available.
* We cannot pre-allocate enough stripe_heads as we may need
* more than exist in the cache (if we allow ever large chunks).
* So we do one stripe head at a time and record in
* ->bi_hw_segments how many have been done.
*
* We *know* that this entire raid_bio is in one chunk, so
* it will be only one 'dd_idx' and only need one call to raid5_compute_sector.
*/
struct stripe_head *sh;
int dd_idx;
sector_t sector, logical_sector, last_sector;
int scnt = 0;
int handled = 0;
logical_sector = raid_bio->bi_iter.bi_sector &
~((sector_t)RAID5_STRIPE_SECTORS(conf)-1);
sector = raid5_compute_sector(conf, logical_sector,
0, &dd_idx, NULL);
last_sector = bio_end_sector(raid_bio);
for (; logical_sector < last_sector;
logical_sector += RAID5_STRIPE_SECTORS(conf),
sector += RAID5_STRIPE_SECTORS(conf),
scnt++) {
if (scnt < offset)
/* already done this stripe */
continue;
sh = raid5_get_active_stripe(conf, NULL, sector,
R5_GAS_NOBLOCK | R5_GAS_NOQUIESCE);
if (!sh) {
/* failed to get a stripe - must wait */
conf->retry_read_aligned = raid_bio;
conf->retry_read_offset = scnt;
return handled;
}
if (!add_stripe_bio(sh, raid_bio, dd_idx, 0, 0)) {
raid5_release_stripe(sh);
conf->retry_read_aligned = raid_bio;
conf->retry_read_offset = scnt;
return handled;
}
set_bit(R5_ReadNoMerge, &sh->dev[dd_idx].flags);
handle_stripe(sh);
raid5_release_stripe(sh);
handled++;
}
bio_endio(raid_bio);
if (atomic_dec_and_test(&conf->active_aligned_reads))
wake_up(&conf->wait_for_quiescent);
return handled;
}
static int handle_active_stripes(struct r5conf *conf, int group,
struct r5worker *worker,
struct list_head *temp_inactive_list)
__must_hold(&conf->device_lock)
{
struct stripe_head *batch[MAX_STRIPE_BATCH], *sh;
int i, batch_size = 0, hash;
bool release_inactive = false;
while (batch_size < MAX_STRIPE_BATCH &&
(sh = __get_priority_stripe(conf, group)) != NULL)
batch[batch_size++] = sh;
if (batch_size == 0) {
for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
if (!list_empty(temp_inactive_list + i))
break;
if (i == NR_STRIPE_HASH_LOCKS) {
spin_unlock_irq(&conf->device_lock);
log_flush_stripe_to_raid(conf);
spin_lock_irq(&conf->device_lock);
return batch_size;
}
release_inactive = true;
}
spin_unlock_irq(&conf->device_lock);
release_inactive_stripe_list(conf, temp_inactive_list,
NR_STRIPE_HASH_LOCKS);
r5l_flush_stripe_to_raid(conf->log);
if (release_inactive) {
spin_lock_irq(&conf->device_lock);
return 0;
}
for (i = 0; i < batch_size; i++)
handle_stripe(batch[i]);
log_write_stripe_run(conf);
cond_resched();
spin_lock_irq(&conf->device_lock);
for (i = 0; i < batch_size; i++) {
hash = batch[i]->hash_lock_index;
__release_stripe(conf, batch[i], &temp_inactive_list[hash]);
}
return batch_size;
}
static void raid5_do_work(struct work_struct *work)
{
struct r5worker *worker = container_of(work, struct r5worker, work);
struct r5worker_group *group = worker->group;
struct r5conf *conf = group->conf;
struct mddev *mddev = conf->mddev;
int group_id = group - conf->worker_groups;
int handled;
struct blk_plug plug;
pr_debug("+++ raid5worker active\n");
blk_start_plug(&plug);
handled = 0;
spin_lock_irq(&conf->device_lock);
while (1) {
int batch_size, released;
released = release_stripe_list(conf, worker->temp_inactive_list);
batch_size = handle_active_stripes(conf, group_id, worker,
worker->temp_inactive_list);
worker->working = false;
if (!batch_size && !released)
break;
handled += batch_size;
wait_event_lock_irq(mddev->sb_wait,
!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags),
conf->device_lock);
}
pr_debug("%d stripes handled\n", handled);
spin_unlock_irq(&conf->device_lock);
flush_deferred_bios(conf);
r5l_flush_stripe_to_raid(conf->log);
async_tx_issue_pending_all();
blk_finish_plug(&plug);
pr_debug("--- raid5worker inactive\n");
}
/*
* This is our raid5 kernel thread.
*
* We scan the hash table for stripes which can be handled now.
* During the scan, completed stripes are saved for us by the interrupt
* handler, so that they will not have to wait for our next wakeup.
*/
static void raid5d(struct md_thread *thread)
{
struct mddev *mddev = thread->mddev;
struct r5conf *conf = mddev->private;
int handled;
struct blk_plug plug;
pr_debug("+++ raid5d active\n");
md_check_recovery(mddev);
blk_start_plug(&plug);
handled = 0;
spin_lock_irq(&conf->device_lock);
while (1) {
struct bio *bio;
int batch_size, released;
unsigned int offset;
released = release_stripe_list(conf, conf->temp_inactive_list);
if (released)
clear_bit(R5_DID_ALLOC, &conf->cache_state);
if (
!list_empty(&conf->bitmap_list)) {
/* Now is a good time to flush some bitmap updates */
conf->seq_flush++;
spin_unlock_irq(&conf->device_lock);
md_bitmap_unplug(mddev->bitmap);
spin_lock_irq(&conf->device_lock);
conf->seq_write = conf->seq_flush;
activate_bit_delay(conf, conf->temp_inactive_list);
}
raid5_activate_delayed(conf);
while ((bio = remove_bio_from_retry(conf, &offset))) {
int ok;
spin_unlock_irq(&conf->device_lock);
ok = retry_aligned_read(conf, bio, offset);
spin_lock_irq(&conf->device_lock);
if (!ok)
break;
handled++;
}
batch_size = handle_active_stripes(conf, ANY_GROUP, NULL,
conf->temp_inactive_list);
if (!batch_size && !released)
break;
handled += batch_size;
if (mddev->sb_flags & ~(1 << MD_SB_CHANGE_PENDING)) {
spin_unlock_irq(&conf->device_lock);
md_check_recovery(mddev);
spin_lock_irq(&conf->device_lock);
/*
* Waiting on MD_SB_CHANGE_PENDING below may deadlock
* seeing md_check_recovery() is needed to clear
* the flag when using mdmon.
*/
continue;
}
wait_event_lock_irq(mddev->sb_wait,
!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags),
conf->device_lock);
}
pr_debug("%d stripes handled\n", handled);
spin_unlock_irq(&conf->device_lock);
if (test_and_clear_bit(R5_ALLOC_MORE, &conf->cache_state) &&
mutex_trylock(&conf->cache_size_mutex)) {
grow_one_stripe(conf, __GFP_NOWARN);
/* Set flag even if allocation failed. This helps
* slow down allocation requests when mem is short
*/
set_bit(R5_DID_ALLOC, &conf->cache_state);
mutex_unlock(&conf->cache_size_mutex);
}
flush_deferred_bios(conf);
r5l_flush_stripe_to_raid(conf->log);
async_tx_issue_pending_all();
blk_finish_plug(&plug);
pr_debug("--- raid5d inactive\n");
}
static ssize_t
raid5_show_stripe_cache_size(struct mddev *mddev, char *page)
{
struct r5conf *conf;
int ret = 0;
spin_lock(&mddev->lock);
conf = mddev->private;
if (conf)
ret = sprintf(page, "%d\n", conf->min_nr_stripes);
spin_unlock(&mddev->lock);
return ret;
}
int
raid5_set_cache_size(struct mddev *mddev, int size)
{
int result = 0;
struct r5conf *conf = mddev->private;
if (size <= 16 || size > 32768)
return -EINVAL;
conf->min_nr_stripes = size;
mutex_lock(&conf->cache_size_mutex);
while (size < conf->max_nr_stripes &&
drop_one_stripe(conf))
;
mutex_unlock(&conf->cache_size_mutex);
md_allow_write(mddev);
mutex_lock(&conf->cache_size_mutex);
while (size > conf->max_nr_stripes)
if (!grow_one_stripe(conf, GFP_KERNEL)) {
conf->min_nr_stripes = conf->max_nr_stripes;
result = -ENOMEM;
break;
}
mutex_unlock(&conf->cache_size_mutex);
return result;
}
EXPORT_SYMBOL(raid5_set_cache_size);
static ssize_t
raid5_store_stripe_cache_size(struct mddev *mddev, const char *page, size_t len)
{
struct r5conf *conf;
unsigned long new;
int err;
if (len >= PAGE_SIZE)
return -EINVAL;
if (kstrtoul(page, 10, &new))
return -EINVAL;
err = mddev_lock(mddev);
if (err)
return err;
conf = mddev->private;
if (!conf)
err = -ENODEV;
else
err = raid5_set_cache_size(mddev, new);
mddev_unlock(mddev);
return err ?: len;
}
static struct md_sysfs_entry
raid5_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR,
raid5_show_stripe_cache_size,
raid5_store_stripe_cache_size);
static ssize_t
raid5_show_rmw_level(struct mddev *mddev, char *page)
{
struct r5conf *conf = mddev->private;
if (conf)
return sprintf(page, "%d\n", conf->rmw_level);
else
return 0;
}
static ssize_t
raid5_store_rmw_level(struct mddev *mddev, const char *page, size_t len)
{
struct r5conf *conf = mddev->private;
unsigned long new;
if (!conf)
return -ENODEV;
if (len >= PAGE_SIZE)
return -EINVAL;
if (kstrtoul(page, 10, &new))
return -EINVAL;
if (new != PARITY_DISABLE_RMW && !raid6_call.xor_syndrome)
return -EINVAL;
if (new != PARITY_DISABLE_RMW &&
new != PARITY_ENABLE_RMW &&
new != PARITY_PREFER_RMW)
return -EINVAL;
conf->rmw_level = new;
return len;
}
static struct md_sysfs_entry
raid5_rmw_level = __ATTR(rmw_level, S_IRUGO | S_IWUSR,
raid5_show_rmw_level,
raid5_store_rmw_level);
static ssize_t
raid5_show_stripe_size(struct mddev *mddev, char *page)
{
struct r5conf *conf;
int ret = 0;
spin_lock(&mddev->lock);
conf = mddev->private;
if (conf)
ret = sprintf(page, "%lu\n", RAID5_STRIPE_SIZE(conf));
spin_unlock(&mddev->lock);
return ret;
}
#if PAGE_SIZE != DEFAULT_STRIPE_SIZE
static ssize_t
raid5_store_stripe_size(struct mddev *mddev, const char *page, size_t len)
{
struct r5conf *conf;
unsigned long new;
int err;
int size;
if (len >= PAGE_SIZE)
return -EINVAL;
if (kstrtoul(page, 10, &new))
return -EINVAL;
/*
* The value should not be bigger than PAGE_SIZE. It requires to
* be multiple of DEFAULT_STRIPE_SIZE and the value should be power
* of two.
*/
if (new % DEFAULT_STRIPE_SIZE != 0 ||
new > PAGE_SIZE || new == 0 ||
new != roundup_pow_of_two(new))
return -EINVAL;
err = mddev_lock(mddev);
if (err)
return err;
conf = mddev->private;
if (!conf) {
err = -ENODEV;
goto out_unlock;
}
if (new == conf->stripe_size)
goto out_unlock;
pr_debug("md/raid: change stripe_size from %lu to %lu\n",
conf->stripe_size, new);
if (mddev->sync_thread ||
test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
mddev->reshape_position != MaxSector ||
mddev->sysfs_active) {
err = -EBUSY;
goto out_unlock;
}
mddev_suspend(mddev);
mutex_lock(&conf->cache_size_mutex);
size = conf->max_nr_stripes;
shrink_stripes(conf);
conf->stripe_size = new;
conf->stripe_shift = ilog2(new) - 9;
conf->stripe_sectors = new >> 9;
if (grow_stripes(conf, size)) {
pr_warn("md/raid:%s: couldn't allocate buffers\n",
mdname(mddev));
err = -ENOMEM;
}
mutex_unlock(&conf->cache_size_mutex);
mddev_resume(mddev);
out_unlock:
mddev_unlock(mddev);
return err ?: len;
}
static struct md_sysfs_entry
raid5_stripe_size = __ATTR(stripe_size, 0644,
raid5_show_stripe_size,
raid5_store_stripe_size);
#else
static struct md_sysfs_entry
raid5_stripe_size = __ATTR(stripe_size, 0444,
raid5_show_stripe_size,
NULL);
#endif
static ssize_t
raid5_show_preread_threshold(struct mddev *mddev, char *page)
{
struct r5conf *conf;
int ret = 0;
spin_lock(&mddev->lock);
conf = mddev->private;
if (conf)
ret = sprintf(page, "%d\n", conf->bypass_threshold);
spin_unlock(&mddev->lock);
return ret;
}
static ssize_t
raid5_store_preread_threshold(struct mddev *mddev, const char *page, size_t len)
{
struct r5conf *conf;
unsigned long new;
int err;
if (len >= PAGE_SIZE)
return -EINVAL;
if (kstrtoul(page, 10, &new))
return -EINVAL;
err = mddev_lock(mddev);
if (err)
return err;
conf = mddev->private;
if (!conf)
err = -ENODEV;
else if (new > conf->min_nr_stripes)
err = -EINVAL;
else
conf->bypass_threshold = new;
mddev_unlock(mddev);
return err ?: len;
}
static struct md_sysfs_entry
raid5_preread_bypass_threshold = __ATTR(preread_bypass_threshold,
S_IRUGO | S_IWUSR,
raid5_show_preread_threshold,
raid5_store_preread_threshold);
static ssize_t
raid5_show_skip_copy(struct mddev *mddev, char *page)
{
struct r5conf *conf;
int ret = 0;
spin_lock(&mddev->lock);
conf = mddev->private;
if (conf)
ret = sprintf(page, "%d\n", conf->skip_copy);
spin_unlock(&mddev->lock);
return ret;
}
static ssize_t
raid5_store_skip_copy(struct mddev *mddev, const char *page, size_t len)
{
struct r5conf *conf;
unsigned long new;
int err;
if (len >= PAGE_SIZE)
return -EINVAL;
if (kstrtoul(page, 10, &new))
return -EINVAL;
new = !!new;
err = mddev_lock(mddev);
if (err)
return err;
conf = mddev->private;
if (!conf)
err = -ENODEV;
else if (new != conf->skip_copy) {
struct request_queue *q = mddev->queue;
mddev_suspend(mddev);
conf->skip_copy = new;
if (new)
blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q);
else
blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, q);
mddev_resume(mddev);
}
mddev_unlock(mddev);
return err ?: len;
}
static struct md_sysfs_entry
raid5_skip_copy = __ATTR(skip_copy, S_IRUGO | S_IWUSR,
raid5_show_skip_copy,
raid5_store_skip_copy);
static ssize_t
stripe_cache_active_show(struct mddev *mddev, char *page)
{
struct r5conf *conf = mddev->private;
if (conf)
return sprintf(page, "%d\n", atomic_read(&conf->active_stripes));
else
return 0;
}
static struct md_sysfs_entry
raid5_stripecache_active = __ATTR_RO(stripe_cache_active);
static ssize_t
raid5_show_group_thread_cnt(struct mddev *mddev, char *page)
{
struct r5conf *conf;
int ret = 0;
spin_lock(&mddev->lock);
conf = mddev->private;
if (conf)
ret = sprintf(page, "%d\n", conf->worker_cnt_per_group);
spin_unlock(&mddev->lock);
return ret;
}
static int alloc_thread_groups(struct r5conf *conf, int cnt,
int *group_cnt,
struct r5worker_group **worker_groups);
static ssize_t
raid5_store_group_thread_cnt(struct mddev *mddev, const char *page, size_t len)
{
struct r5conf *conf;
unsigned int new;
int err;
struct r5worker_group *new_groups, *old_groups;
int group_cnt;
if (len >= PAGE_SIZE)
return -EINVAL;
if (kstrtouint(page, 10, &new))
return -EINVAL;
/* 8192 should be big enough */
if (new > 8192)
return -EINVAL;
err = mddev_lock(mddev);
if (err)
return err;
conf = mddev->private;
if (!conf)
err = -ENODEV;
else if (new != conf->worker_cnt_per_group) {
mddev_suspend(mddev);
old_groups = conf->worker_groups;
if (old_groups)
flush_workqueue(raid5_wq);
err = alloc_thread_groups(conf, new, &group_cnt, &new_groups);
if (!err) {
spin_lock_irq(&conf->device_lock);
conf->group_cnt = group_cnt;
conf->worker_cnt_per_group = new;
conf->worker_groups = new_groups;
spin_unlock_irq(&conf->device_lock);
if (old_groups)
kfree(old_groups[0].workers);
kfree(old_groups);
}
mddev_resume(mddev);
}
mddev_unlock(mddev);
return err ?: len;
}
static struct md_sysfs_entry
raid5_group_thread_cnt = __ATTR(group_thread_cnt, S_IRUGO | S_IWUSR,
raid5_show_group_thread_cnt,
raid5_store_group_thread_cnt);
static struct attribute *raid5_attrs[] = {
&raid5_stripecache_size.attr,
&raid5_stripecache_active.attr,
&raid5_preread_bypass_threshold.attr,
&raid5_group_thread_cnt.attr,
&raid5_skip_copy.attr,
&raid5_rmw_level.attr,
&raid5_stripe_size.attr,
&r5c_journal_mode.attr,
&ppl_write_hint.attr,
NULL,
};
static const struct attribute_group raid5_attrs_group = {
.name = NULL,
.attrs = raid5_attrs,
};
static int alloc_thread_groups(struct r5conf *conf, int cnt, int *group_cnt,
struct r5worker_group **worker_groups)
{
int i, j, k;
ssize_t size;
struct r5worker *workers;
if (cnt == 0) {
*group_cnt = 0;
*worker_groups = NULL;
return 0;
}
*group_cnt = num_possible_nodes();
size = sizeof(struct r5worker) * cnt;
workers = kcalloc(size, *group_cnt, GFP_NOIO);
*worker_groups = kcalloc(*group_cnt, sizeof(struct r5worker_group),
GFP_NOIO);
if (!*worker_groups || !workers) {
kfree(workers);
kfree(*worker_groups);
return -ENOMEM;
}
for (i = 0; i < *group_cnt; i++) {
struct r5worker_group *group;
group = &(*worker_groups)[i];
INIT_LIST_HEAD(&group->handle_list);
INIT_LIST_HEAD(&group->loprio_list);
group->conf = conf;
group->workers = workers + i * cnt;
for (j = 0; j < cnt; j++) {
struct r5worker *worker = group->workers + j;
worker->group = group;
INIT_WORK(&worker->work, raid5_do_work);
for (k = 0; k < NR_STRIPE_HASH_LOCKS; k++)
INIT_LIST_HEAD(worker->temp_inactive_list + k);
}
}
return 0;
}
static void free_thread_groups(struct r5conf *conf)
{
if (conf->worker_groups)
kfree(conf->worker_groups[0].workers);
kfree(conf->worker_groups);
conf->worker_groups = NULL;
}
static sector_t
raid5_size(struct mddev *mddev, sector_t sectors, int raid_disks)
{
struct r5conf *conf = mddev->private;
if (!sectors)
sectors = mddev->dev_sectors;
if (!raid_disks)
/* size is defined by the smallest of previous and new size */
raid_disks = min(conf->raid_disks, conf->previous_raid_disks);
sectors &= ~((sector_t)conf->chunk_sectors - 1);
sectors &= ~((sector_t)conf->prev_chunk_sectors - 1);
return sectors * (raid_disks - conf->max_degraded);
}
static void free_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu)
{
safe_put_page(percpu->spare_page);
percpu->spare_page = NULL;
kvfree(percpu->scribble);
percpu->scribble = NULL;
}
static int alloc_scratch_buffer(struct r5conf *conf, struct raid5_percpu *percpu)
{
if (conf->level == 6 && !percpu->spare_page) {
percpu->spare_page = alloc_page(GFP_KERNEL);
if (!percpu->spare_page)
return -ENOMEM;
}
if (scribble_alloc(percpu,
max(conf->raid_disks,
conf->previous_raid_disks),
max(conf->chunk_sectors,
conf->prev_chunk_sectors)
/ RAID5_STRIPE_SECTORS(conf))) {
free_scratch_buffer(conf, percpu);
return -ENOMEM;
}
local_lock_init(&percpu->lock);
return 0;
}
static int raid456_cpu_dead(unsigned int cpu, struct hlist_node *node)
{
struct r5conf *conf = hlist_entry_safe(node, struct r5conf, node);
free_scratch_buffer(conf, per_cpu_ptr(conf->percpu, cpu));
return 0;
}
static void raid5_free_percpu(struct r5conf *conf)
{
if (!conf->percpu)
return;
cpuhp_state_remove_instance(CPUHP_MD_RAID5_PREPARE, &conf->node);
free_percpu(conf->percpu);
}
static void free_conf(struct r5conf *conf)
{
int i;
log_exit(conf);
unregister_shrinker(&conf->shrinker);
free_thread_groups(conf);
shrink_stripes(conf);
raid5_free_percpu(conf);
for (i = 0; i < conf->pool_size; i++)
if (conf->disks[i].extra_page)
put_page(conf->disks[i].extra_page);
kfree(conf->disks);
bioset_exit(&conf->bio_split);
kfree(conf->stripe_hashtbl);
kfree(conf->pending_data);
kfree(conf);
}
static int raid456_cpu_up_prepare(unsigned int cpu, struct hlist_node *node)
{
struct r5conf *conf = hlist_entry_safe(node, struct r5conf, node);
struct raid5_percpu *percpu = per_cpu_ptr(conf->percpu, cpu);
if (alloc_scratch_buffer(conf, percpu)) {
pr_warn("%s: failed memory allocation for cpu%u\n",
__func__, cpu);
return -ENOMEM;
}
return 0;
}
static int raid5_alloc_percpu(struct r5conf *conf)
{
int err = 0;
conf->percpu = alloc_percpu(struct raid5_percpu);
if (!conf->percpu)
return -ENOMEM;
err = cpuhp_state_add_instance(CPUHP_MD_RAID5_PREPARE, &conf->node);
if (!err) {
conf->scribble_disks = max(conf->raid_disks,
conf->previous_raid_disks);
conf->scribble_sectors = max(conf->chunk_sectors,
conf->prev_chunk_sectors);
}
return err;
}
static unsigned long raid5_cache_scan(struct shrinker *shrink,
struct shrink_control *sc)
{
struct r5conf *conf = container_of(shrink, struct r5conf, shrinker);
unsigned long ret = SHRINK_STOP;
if (mutex_trylock(&conf->cache_size_mutex)) {
ret= 0;
while (ret < sc->nr_to_scan &&
conf->max_nr_stripes > conf->min_nr_stripes) {
if (drop_one_stripe(conf) == 0) {
ret = SHRINK_STOP;
break;
}
ret++;
}
mutex_unlock(&conf->cache_size_mutex);
}
return ret;
}
static unsigned long raid5_cache_count(struct shrinker *shrink,
struct shrink_control *sc)
{
struct r5conf *conf = container_of(shrink, struct r5conf, shrinker);
if (conf->max_nr_stripes < conf->min_nr_stripes)
/* unlikely, but not impossible */
return 0;
return conf->max_nr_stripes - conf->min_nr_stripes;
}
static struct r5conf *setup_conf(struct mddev *mddev)
{
struct r5conf *conf;
int raid_disk, memory, max_disks;
struct md_rdev *rdev;
struct disk_info *disk;
char pers_name[6];
int i;
int group_cnt;
struct r5worker_group *new_group;
int ret = -ENOMEM;
if (mddev->new_level != 5
&& mddev->new_level != 4
&& mddev->new_level != 6) {
pr_warn("md/raid:%s: raid level not set to 4/5/6 (%d)\n",
mdname(mddev), mddev->new_level);
return ERR_PTR(-EIO);
}
if ((mddev->new_level == 5
&& !algorithm_valid_raid5(mddev->new_layout)) ||
(mddev->new_level == 6
&& !algorithm_valid_raid6(mddev->new_layout))) {
pr_warn("md/raid:%s: layout %d not supported\n",
mdname(mddev), mddev->new_layout);
return ERR_PTR(-EIO);
}
if (mddev->new_level == 6 && mddev->raid_disks < 4) {
pr_warn("md/raid:%s: not enough configured devices (%d, minimum 4)\n",
mdname(mddev), mddev->raid_disks);
return ERR_PTR(-EINVAL);
}
if (!mddev->new_chunk_sectors ||
(mddev->new_chunk_sectors << 9) % PAGE_SIZE ||
!is_power_of_2(mddev->new_chunk_sectors)) {
pr_warn("md/raid:%s: invalid chunk size %d\n",
mdname(mddev), mddev->new_chunk_sectors << 9);
return ERR_PTR(-EINVAL);
}
conf = kzalloc(sizeof(struct r5conf), GFP_KERNEL);
if (conf == NULL)
goto abort;
#if PAGE_SIZE != DEFAULT_STRIPE_SIZE
conf->stripe_size = DEFAULT_STRIPE_SIZE;
conf->stripe_shift = ilog2(DEFAULT_STRIPE_SIZE) - 9;
conf->stripe_sectors = DEFAULT_STRIPE_SIZE >> 9;
#endif
INIT_LIST_HEAD(&conf->free_list);
INIT_LIST_HEAD(&conf->pending_list);
conf->pending_data = kcalloc(PENDING_IO_MAX,
sizeof(struct r5pending_data),
GFP_KERNEL);
if (!conf->pending_data)
goto abort;
for (i = 0; i < PENDING_IO_MAX; i++)
list_add(&conf->pending_data[i].sibling, &conf->free_list);
/* Don't enable multi-threading by default*/
if (!alloc_thread_groups(conf, 0, &group_cnt, &new_group)) {
conf->group_cnt = group_cnt;
conf->worker_cnt_per_group = 0;
conf->worker_groups = new_group;
} else
goto abort;
spin_lock_init(&conf->device_lock);
seqcount_spinlock_init(&conf->gen_lock, &conf->device_lock);
mutex_init(&conf->cache_size_mutex);
init_waitqueue_head(&conf->wait_for_quiescent);
init_waitqueue_head(&conf->wait_for_stripe);
init_waitqueue_head(&conf->wait_for_overlap);
INIT_LIST_HEAD(&conf->handle_list);
INIT_LIST_HEAD(&conf->loprio_list);
INIT_LIST_HEAD(&conf->hold_list);
INIT_LIST_HEAD(&conf->delayed_list);
INIT_LIST_HEAD(&conf->bitmap_list);
init_llist_head(&conf->released_stripes);
atomic_set(&conf->active_stripes, 0);
atomic_set(&conf->preread_active_stripes, 0);
atomic_set(&conf->active_aligned_reads, 0);
spin_lock_init(&conf->pending_bios_lock);
conf->batch_bio_dispatch = true;
rdev_for_each(rdev, mddev) {
if (test_bit(Journal, &rdev->flags))
continue;
if (bdev_nonrot(rdev->bdev)) {
conf->batch_bio_dispatch = false;
break;
}
}
conf->bypass_threshold = BYPASS_THRESHOLD;
conf->recovery_disabled = mddev->recovery_disabled - 1;
conf->raid_disks = mddev->raid_disks;
if (mddev->reshape_position == MaxSector)
conf->previous_raid_disks = mddev->raid_disks;
else
conf->previous_raid_disks = mddev->raid_disks - mddev->delta_disks;
max_disks = max(conf->raid_disks, conf->previous_raid_disks);
conf->disks = kcalloc(max_disks, sizeof(struct disk_info),
GFP_KERNEL);
if (!conf->disks)
goto abort;
for (i = 0; i < max_disks; i++) {
conf->disks[i].extra_page = alloc_page(GFP_KERNEL);
if (!conf->disks[i].extra_page)
goto abort;
}
ret = bioset_init(&conf->bio_split, BIO_POOL_SIZE, 0, 0);
if (ret)
goto abort;
conf->mddev = mddev;
ret = -ENOMEM;
conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL);
if (!conf->stripe_hashtbl)
goto abort;
/* We init hash_locks[0] separately to that it can be used
* as the reference lock in the spin_lock_nest_lock() call
* in lock_all_device_hash_locks_irq in order to convince
* lockdep that we know what we are doing.
*/
spin_lock_init(conf->hash_locks);
for (i = 1; i < NR_STRIPE_HASH_LOCKS; i++)
spin_lock_init(conf->hash_locks + i);
for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
INIT_LIST_HEAD(conf->inactive_list + i);
for (i = 0; i < NR_STRIPE_HASH_LOCKS; i++)
INIT_LIST_HEAD(conf->temp_inactive_list + i);
atomic_set(&conf->r5c_cached_full_stripes, 0);
INIT_LIST_HEAD(&conf->r5c_full_stripe_list);
atomic_set(&conf->r5c_cached_partial_stripes, 0);
INIT_LIST_HEAD(&conf->r5c_partial_stripe_list);
atomic_set(&conf->r5c_flushing_full_stripes, 0);
atomic_set(&conf->r5c_flushing_partial_stripes, 0);
conf->level = mddev->new_level;
conf->chunk_sectors = mddev->new_chunk_sectors;
ret = raid5_alloc_percpu(conf);
if (ret)
goto abort;
pr_debug("raid456: run(%s) called.\n", mdname(mddev));
ret = -EIO;
rdev_for_each(rdev, mddev) {
raid_disk = rdev->raid_disk;
if (raid_disk >= max_disks
|| raid_disk < 0 || test_bit(Journal, &rdev->flags))
continue;
disk = conf->disks + raid_disk;
if (test_bit(Replacement, &rdev->flags)) {
if (disk->replacement)
goto abort;
RCU_INIT_POINTER(disk->replacement, rdev);
} else {
if (disk->rdev)
goto abort;
RCU_INIT_POINTER(disk->rdev, rdev);
}
if (test_bit(In_sync, &rdev->flags)) {
pr_info("md/raid:%s: device %pg operational as raid disk %d\n",
mdname(mddev), rdev->bdev, raid_disk);
} else if (rdev->saved_raid_disk != raid_disk)
/* Cannot rely on bitmap to complete recovery */
conf->fullsync = 1;
}
conf->level = mddev->new_level;
if (conf->level == 6) {
conf->max_degraded = 2;
if (raid6_call.xor_syndrome)
conf->rmw_level = PARITY_ENABLE_RMW;
else
conf->rmw_level = PARITY_DISABLE_RMW;
} else {
conf->max_degraded = 1;
conf->rmw_level = PARITY_ENABLE_RMW;
}
conf->algorithm = mddev->new_layout;
conf->reshape_progress = mddev->reshape_position;
if (conf->reshape_progress != MaxSector) {
conf->prev_chunk_sectors = mddev->chunk_sectors;
conf->prev_algo = mddev->layout;
} else {
conf->prev_chunk_sectors = conf->chunk_sectors;
conf->prev_algo = conf->algorithm;
}
conf->min_nr_stripes = NR_STRIPES;
if (mddev->reshape_position != MaxSector) {
int stripes = max_t(int,
((mddev->chunk_sectors << 9) / RAID5_STRIPE_SIZE(conf)) * 4,
((mddev->new_chunk_sectors << 9) / RAID5_STRIPE_SIZE(conf)) * 4);
conf->min_nr_stripes = max(NR_STRIPES, stripes);
if (conf->min_nr_stripes != NR_STRIPES)
pr_info("md/raid:%s: force stripe size %d for reshape\n",
mdname(mddev), conf->min_nr_stripes);
}
memory = conf->min_nr_stripes * (sizeof(struct stripe_head) +
max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
atomic_set(&conf->empty_inactive_list_nr, NR_STRIPE_HASH_LOCKS);
if (grow_stripes(conf, conf->min_nr_stripes)) {
pr_warn("md/raid:%s: couldn't allocate %dkB for buffers\n",
mdname(mddev), memory);
ret = -ENOMEM;
goto abort;
} else
pr_debug("md/raid:%s: allocated %dkB\n", mdname(mddev), memory);
/*
* Losing a stripe head costs more than the time to refill it,
* it reduces the queue depth and so can hurt throughput.
* So set it rather large, scaled by number of devices.
*/
conf->shrinker.seeks = DEFAULT_SEEKS * conf->raid_disks * 4;
conf->shrinker.scan_objects = raid5_cache_scan;
conf->shrinker.count_objects = raid5_cache_count;
conf->shrinker.batch = 128;
conf->shrinker.flags = 0;
ret = register_shrinker(&conf->shrinker, "md-raid5:%s", mdname(mddev));
if (ret) {
pr_warn("md/raid:%s: couldn't register shrinker.\n",
mdname(mddev));
goto abort;
}
sprintf(pers_name, "raid%d", mddev->new_level);
rcu_assign_pointer(conf->thread,
md_register_thread(raid5d, mddev, pers_name));
if (!conf->thread) {
pr_warn("md/raid:%s: couldn't allocate thread.\n",
mdname(mddev));
ret = -ENOMEM;
goto abort;
}
return conf;
abort:
if (conf)
free_conf(conf);
return ERR_PTR(ret);
}
static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded)
{
switch (algo) {
case ALGORITHM_PARITY_0:
if (raid_disk < max_degraded)
return 1;
break;
case ALGORITHM_PARITY_N:
if (raid_disk >= raid_disks - max_degraded)
return 1;
break;
case ALGORITHM_PARITY_0_6:
if (raid_disk == 0 ||
raid_disk == raid_disks - 1)
return 1;
break;
case ALGORITHM_LEFT_ASYMMETRIC_6:
case ALGORITHM_RIGHT_ASYMMETRIC_6:
case ALGORITHM_LEFT_SYMMETRIC_6:
case ALGORITHM_RIGHT_SYMMETRIC_6:
if (raid_disk == raid_disks - 1)
return 1;
}
return 0;
}
static void raid5_set_io_opt(struct r5conf *conf)
{
blk_queue_io_opt(conf->mddev->queue, (conf->chunk_sectors << 9) *
(conf->raid_disks - conf->max_degraded));
}
static int raid5_run(struct mddev *mddev)
{
struct r5conf *conf;
int dirty_parity_disks = 0;
struct md_rdev *rdev;
struct md_rdev *journal_dev = NULL;
sector_t reshape_offset = 0;
int i;
long long min_offset_diff = 0;
int first = 1;
if (mddev_init_writes_pending(mddev) < 0)
return -ENOMEM;
if (mddev->recovery_cp != MaxSector)
pr_notice("md/raid:%s: not clean -- starting background reconstruction\n",
mdname(mddev));
rdev_for_each(rdev, mddev) {
long long diff;
if (test_bit(Journal, &rdev->flags)) {
journal_dev = rdev;
continue;
}
if (rdev->raid_disk < 0)
continue;
diff = (rdev->new_data_offset - rdev->data_offset);
if (first) {
min_offset_diff = diff;
first = 0;
} else if (mddev->reshape_backwards &&
diff < min_offset_diff)
min_offset_diff = diff;
else if (!mddev->reshape_backwards &&
diff > min_offset_diff)
min_offset_diff = diff;
}
if ((test_bit(MD_HAS_JOURNAL, &mddev->flags) || journal_dev) &&
(mddev->bitmap_info.offset || mddev->bitmap_info.file)) {
pr_notice("md/raid:%s: array cannot have both journal and bitmap\n",
mdname(mddev));
return -EINVAL;
}
if (mddev->reshape_position != MaxSector) {
/* Check that we can continue the reshape.
* Difficulties arise if the stripe we would write to
* next is at or after the stripe we would read from next.
* For a reshape that changes the number of devices, this
* is only possible for a very short time, and mdadm makes
* sure that time appears to have past before assembling
* the array. So we fail if that time hasn't passed.
* For a reshape that keeps the number of devices the same
* mdadm must be monitoring the reshape can keeping the
* critical areas read-only and backed up. It will start
* the array in read-only mode, so we check for that.
*/
sector_t here_new, here_old;
int old_disks;
int max_degraded = (mddev->level == 6 ? 2 : 1);
int chunk_sectors;
int new_data_disks;
if (journal_dev) {
pr_warn("md/raid:%s: don't support reshape with journal - aborting.\n",
mdname(mddev));
return -EINVAL;
}
if (mddev->new_level != mddev->level) {
pr_warn("md/raid:%s: unsupported reshape required - aborting.\n",
mdname(mddev));
return -EINVAL;
}
old_disks = mddev->raid_disks - mddev->delta_disks;
/* reshape_position must be on a new-stripe boundary, and one
* further up in new geometry must map after here in old
* geometry.
* If the chunk sizes are different, then as we perform reshape
* in units of the largest of the two, reshape_position needs
* be a multiple of the largest chunk size times new data disks.
*/
here_new = mddev->reshape_position;
chunk_sectors = max(mddev->chunk_sectors, mddev->new_chunk_sectors);
new_data_disks = mddev->raid_disks - max_degraded;
if (sector_div(here_new, chunk_sectors * new_data_disks)) {
pr_warn("md/raid:%s: reshape_position not on a stripe boundary\n",
mdname(mddev));
return -EINVAL;
}
reshape_offset = here_new * chunk_sectors;
/* here_new is the stripe we will write to */
here_old = mddev->reshape_position;
sector_div(here_old, chunk_sectors * (old_disks-max_degraded));
/* here_old is the first stripe that we might need to read
* from */
if (mddev->delta_disks == 0) {
/* We cannot be sure it is safe to start an in-place
* reshape. It is only safe if user-space is monitoring
* and taking constant backups.
* mdadm always starts a situation like this in
* readonly mode so it can take control before
* allowing any writes. So just check for that.
*/
if (abs(min_offset_diff) >= mddev->chunk_sectors &&
abs(min_offset_diff) >= mddev->new_chunk_sectors)
/* not really in-place - so OK */;
else if (mddev->ro == 0) {
pr_warn("md/raid:%s: in-place reshape must be started in read-only mode - aborting\n",
mdname(mddev));
return -EINVAL;
}
} else if (mddev->reshape_backwards
? (here_new * chunk_sectors + min_offset_diff <=
here_old * chunk_sectors)
: (here_new * chunk_sectors >=
here_old * chunk_sectors + (-min_offset_diff))) {
/* Reading from the same stripe as writing to - bad */
pr_warn("md/raid:%s: reshape_position too early for auto-recovery - aborting.\n",
mdname(mddev));
return -EINVAL;
}
pr_debug("md/raid:%s: reshape will continue\n", mdname(mddev));
/* OK, we should be able to continue; */
} else {
BUG_ON(mddev->level != mddev->new_level);
BUG_ON(mddev->layout != mddev->new_layout);
BUG_ON(mddev->chunk_sectors != mddev->new_chunk_sectors);
BUG_ON(mddev->delta_disks != 0);
}
if (test_bit(MD_HAS_JOURNAL, &mddev->flags) &&
test_bit(MD_HAS_PPL, &mddev->flags)) {
pr_warn("md/raid:%s: using journal device and PPL not allowed - disabling PPL\n",
mdname(mddev));
clear_bit(MD_HAS_PPL, &mddev->flags);
clear_bit(MD_HAS_MULTIPLE_PPLS, &mddev->flags);
}
if (mddev->private == NULL)
conf = setup_conf(mddev);
else
conf = mddev->private;
if (IS_ERR(conf))
return PTR_ERR(conf);
if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) {
if (!journal_dev) {
pr_warn("md/raid:%s: journal disk is missing, force array readonly\n",
mdname(mddev));
mddev->ro = 1;
set_disk_ro(mddev->gendisk, 1);
} else if (mddev->recovery_cp == MaxSector)
set_bit(MD_JOURNAL_CLEAN, &mddev->flags);
}
conf->min_offset_diff = min_offset_diff;
rcu_assign_pointer(mddev->thread, conf->thread);
rcu_assign_pointer(conf->thread, NULL);
mddev->private = conf;
for (i = 0; i < conf->raid_disks && conf->previous_raid_disks;
i++) {
rdev = rdev_mdlock_deref(mddev, conf->disks[i].rdev);
if (!rdev && conf->disks[i].replacement) {
/* The replacement is all we have yet */
rdev = rdev_mdlock_deref(mddev,
conf->disks[i].replacement);
conf->disks[i].replacement = NULL;
clear_bit(Replacement, &rdev->flags);
rcu_assign_pointer(conf->disks[i].rdev, rdev);
}
if (!rdev)
continue;
if (rcu_access_pointer(conf->disks[i].replacement) &&
conf->reshape_progress != MaxSector) {
/* replacements and reshape simply do not mix. */
pr_warn("md: cannot handle concurrent replacement and reshape.\n");
goto abort;
}
if (test_bit(In_sync, &rdev->flags))
continue;
/* This disc is not fully in-sync. However if it
* just stored parity (beyond the recovery_offset),
* when we don't need to be concerned about the
* array being dirty.
* When reshape goes 'backwards', we never have
* partially completed devices, so we only need
* to worry about reshape going forwards.
*/
/* Hack because v0.91 doesn't store recovery_offset properly. */
if (mddev->major_version == 0 &&
mddev->minor_version > 90)
rdev->recovery_offset = reshape_offset;
if (rdev->recovery_offset < reshape_offset) {
/* We need to check old and new layout */
if (!only_parity(rdev->raid_disk,
conf->algorithm,
conf->raid_disks,
conf->max_degraded))
continue;
}
if (!only_parity(rdev->raid_disk,
conf->prev_algo,
conf->previous_raid_disks,
conf->max_degraded))
continue;
dirty_parity_disks++;
}
/*
* 0 for a fully functional array, 1 or 2 for a degraded array.
*/
mddev->degraded = raid5_calc_degraded(conf);
if (has_failed(conf)) {
pr_crit("md/raid:%s: not enough operational devices (%d/%d failed)\n",
mdname(mddev), mddev->degraded, conf->raid_disks);
goto abort;
}
/* device size must be a multiple of chunk size */
mddev->dev_sectors &= ~((sector_t)mddev->chunk_sectors - 1);
mddev->resync_max_sectors = mddev->dev_sectors;
if (mddev->degraded > dirty_parity_disks &&
mddev->recovery_cp != MaxSector) {
if (test_bit(MD_HAS_PPL, &mddev->flags))
pr_crit("md/raid:%s: starting dirty degraded array with PPL.\n",
mdname(mddev));
else if (mddev->ok_start_degraded)
pr_crit("md/raid:%s: starting dirty degraded array - data corruption possible.\n",
mdname(mddev));
else {
pr_crit("md/raid:%s: cannot start dirty degraded array.\n",
mdname(mddev));
goto abort;
}
}
pr_info("md/raid:%s: raid level %d active with %d out of %d devices, algorithm %d\n",
mdname(mddev), conf->level,
mddev->raid_disks-mddev->degraded, mddev->raid_disks,
mddev->new_layout);
print_raid5_conf(conf);
if (conf->reshape_progress != MaxSector) {
conf->reshape_safe = conf->reshape_progress;
atomic_set(&conf->reshape_stripes, 0);
clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
rcu_assign_pointer(mddev->sync_thread,
md_register_thread(md_do_sync, mddev, "reshape"));
if (!mddev->sync_thread)
goto abort;
}
/* Ok, everything is just fine now */
if (mddev->to_remove == &raid5_attrs_group)
mddev->to_remove = NULL;
else if (mddev->kobj.sd &&
sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
pr_warn("raid5: failed to create sysfs attributes for %s\n",
mdname(mddev));
md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
if (mddev->queue) {
int chunk_size;
/* read-ahead size must cover two whole stripes, which
* is 2 * (datadisks) * chunksize where 'n' is the
* number of raid devices
*/
int data_disks = conf->previous_raid_disks - conf->max_degraded;
int stripe = data_disks *
((mddev->chunk_sectors << 9) / PAGE_SIZE);
chunk_size = mddev->chunk_sectors << 9;
blk_queue_io_min(mddev->queue, chunk_size);
raid5_set_io_opt(conf);
mddev->queue->limits.raid_partial_stripes_expensive = 1;
/*
* We can only discard a whole stripe. It doesn't make sense to
* discard data disk but write parity disk
*/
stripe = stripe * PAGE_SIZE;
stripe = roundup_pow_of_two(stripe);
mddev->queue->limits.discard_granularity = stripe;
blk_queue_max_write_zeroes_sectors(mddev->queue, 0);
rdev_for_each(rdev, mddev) {
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->new_data_offset << 9);
}
/*
* zeroing is required, otherwise data
* could be lost. Consider a scenario: discard a stripe
* (the stripe could be inconsistent if
* discard_zeroes_data is 0); write one disk of the
* stripe (the stripe could be inconsistent again
* depending on which disks are used to calculate
* parity); the disk is broken; The stripe data of this
* disk is lost.
*
* We only allow DISCARD if the sysadmin has confirmed that
* only safe devices are in use by setting a module parameter.
* A better idea might be to turn DISCARD into WRITE_ZEROES
* requests, as that is required to be safe.
*/
if (!devices_handle_discard_safely ||
mddev->queue->limits.max_discard_sectors < (stripe >> 9) ||
mddev->queue->limits.discard_granularity < stripe)
blk_queue_max_discard_sectors(mddev->queue, 0);
/*
* Requests require having a bitmap for each stripe.
* Limit the max sectors based on this.
*/
blk_queue_max_hw_sectors(mddev->queue,
RAID5_MAX_REQ_STRIPES << RAID5_STRIPE_SHIFT(conf));
/* No restrictions on the number of segments in the request */
blk_queue_max_segments(mddev->queue, USHRT_MAX);
}
if (log_init(conf, journal_dev, raid5_has_ppl(conf)))
goto abort;
return 0;
abort:
md_unregister_thread(mddev, &mddev->thread);
print_raid5_conf(conf);
free_conf(conf);
mddev->private = NULL;
pr_warn("md/raid:%s: failed to run raid set.\n", mdname(mddev));
return -EIO;
}
static void raid5_free(struct mddev *mddev, void *priv)
{
struct r5conf *conf = priv;
free_conf(conf);
mddev->to_remove = &raid5_attrs_group;
}
static void raid5_status(struct seq_file *seq, struct mddev *mddev)
{
struct r5conf *conf = mddev->private;
int i;
seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level,
conf->chunk_sectors / 2, mddev->layout);
seq_printf (seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded);
rcu_read_lock();
for (i = 0; i < conf->raid_disks; i++) {
struct md_rdev *rdev = rcu_dereference(conf->disks[i].rdev);
seq_printf (seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
}
rcu_read_unlock();
seq_printf (seq, "]");
}
static void print_raid5_conf (struct r5conf *conf)
{
struct md_rdev *rdev;
int i;
pr_debug("RAID conf printout:\n");
if (!conf) {
pr_debug("(conf==NULL)\n");
return;
}
pr_debug(" --- level:%d rd:%d wd:%d\n", conf->level,
conf->raid_disks,
conf->raid_disks - conf->mddev->degraded);
rcu_read_lock();
for (i = 0; i < conf->raid_disks; i++) {
rdev = rcu_dereference(conf->disks[i].rdev);
if (rdev)
pr_debug(" disk %d, o:%d, dev:%pg\n",
i, !test_bit(Faulty, &rdev->flags),
rdev->bdev);
}
rcu_read_unlock();
}
static int raid5_spare_active(struct mddev *mddev)
{
int i;
struct r5conf *conf = mddev->private;
struct md_rdev *rdev, *replacement;
int count = 0;
unsigned long flags;
for (i = 0; i < conf->raid_disks; i++) {
rdev = rdev_mdlock_deref(mddev, conf->disks[i].rdev);
replacement = rdev_mdlock_deref(mddev,
conf->disks[i].replacement);
if (replacement
&& replacement->recovery_offset == MaxSector
&& !test_bit(Faulty, &replacement->flags)
&& !test_and_set_bit(In_sync, &replacement->flags)) {
/* Replacement has just become active. */
if (!rdev
|| !test_and_clear_bit(In_sync, &rdev->flags))
count++;
if (rdev) {
/* Replaced device not technically faulty,
* but we need to be sure it gets removed
* and never re-added.
*/
set_bit(Faulty, &rdev->flags);
sysfs_notify_dirent_safe(
rdev->sysfs_state);
}
sysfs_notify_dirent_safe(replacement->sysfs_state);
} else if (rdev
&& rdev->recovery_offset == MaxSector
&& !test_bit(Faulty, &rdev->flags)
&& !test_and_set_bit(In_sync, &rdev->flags)) {
count++;
sysfs_notify_dirent_safe(rdev->sysfs_state);
}
}
spin_lock_irqsave(&conf->device_lock, flags);
mddev->degraded = raid5_calc_degraded(conf);
spin_unlock_irqrestore(&conf->device_lock, flags);
print_raid5_conf(conf);
return count;
}
static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
{
struct r5conf *conf = mddev->private;
int err = 0;
int number = rdev->raid_disk;
struct md_rdev __rcu **rdevp;
struct disk_info *p;
struct md_rdev *tmp;
print_raid5_conf(conf);
if (test_bit(Journal, &rdev->flags) && conf->log) {
/*
* we can't wait pending write here, as this is called in
* raid5d, wait will deadlock.
* neilb: there is no locking about new writes here,
* so this cannot be safe.
*/
if (atomic_read(&conf->active_stripes) ||
atomic_read(&conf->r5c_cached_full_stripes) ||
atomic_read(&conf->r5c_cached_partial_stripes)) {
return -EBUSY;
}
log_exit(conf);
return 0;
}
if (unlikely(number >= conf->pool_size))
return 0;
p = conf->disks + number;
if (rdev == rcu_access_pointer(p->rdev))
rdevp = &p->rdev;
else if (rdev == rcu_access_pointer(p->replacement))
rdevp = &p->replacement;
else
return 0;
if (number >= conf->raid_disks &&
conf->reshape_progress == MaxSector)
clear_bit(In_sync, &rdev->flags);
if (test_bit(In_sync, &rdev->flags) ||
atomic_read(&rdev->nr_pending)) {
err = -EBUSY;
goto abort;
}
/* Only remove non-faulty devices if recovery
* isn't possible.
*/
if (!test_bit(Faulty, &rdev->flags) &&
mddev->recovery_disabled != conf->recovery_disabled &&
!has_failed(conf) &&
(!rcu_access_pointer(p->replacement) ||
rcu_access_pointer(p->replacement) == rdev) &&
number < conf->raid_disks) {
err = -EBUSY;
goto abort;
}
*rdevp = NULL;
if (!test_bit(RemoveSynchronized, &rdev->flags)) {
lockdep_assert_held(&mddev->reconfig_mutex);
synchronize_rcu();
if (atomic_read(&rdev->nr_pending)) {
/* lost the race, try later */
err = -EBUSY;
rcu_assign_pointer(*rdevp, rdev);
}
}
if (!err) {
err = log_modify(conf, rdev, false);
if (err)
goto abort;
}
tmp = rcu_access_pointer(p->replacement);
if (tmp) {
/* We must have just cleared 'rdev' */
rcu_assign_pointer(p->rdev, tmp);
clear_bit(Replacement, &tmp->flags);
smp_mb(); /* Make sure other CPUs may see both as identical
* but will never see neither - if they are careful
*/
rcu_assign_pointer(p->replacement, NULL);
if (!err)
err = log_modify(conf, tmp, true);
}
clear_bit(WantReplacement, &rdev->flags);
abort:
print_raid5_conf(conf);
return err;
}
static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev)
{
struct r5conf *conf = mddev->private;
int ret, err = -EEXIST;
int disk;
struct disk_info *p;
struct md_rdev *tmp;
int first = 0;
int last = conf->raid_disks - 1;
if (test_bit(Journal, &rdev->flags)) {
if (conf->log)
return -EBUSY;
rdev->raid_disk = 0;
/*
* The array is in readonly mode if journal is missing, so no
* write requests running. We should be safe
*/
ret = log_init(conf, rdev, false);
if (ret)
return ret;
ret = r5l_start(conf->log);
if (ret)
return ret;
return 0;
}
if (mddev->recovery_disabled == conf->recovery_disabled)
return -EBUSY;
if (rdev->saved_raid_disk < 0 && has_failed(conf))
/* no point adding a device */
return -EINVAL;
if (rdev->raid_disk >= 0)
first = last = rdev->raid_disk;
/*
* find the disk ... but prefer rdev->saved_raid_disk
* if possible.
*/
if (rdev->saved_raid_disk >= first &&
rdev->saved_raid_disk <= last &&
conf->disks[rdev->saved_raid_disk].rdev == NULL)
first = rdev->saved_raid_disk;
for (disk = first; disk <= last; disk++) {
p = conf->disks + disk;
if (p->rdev == NULL) {
clear_bit(In_sync, &rdev->flags);
rdev->raid_disk = disk;
if (rdev->saved_raid_disk != disk)
conf->fullsync = 1;
rcu_assign_pointer(p->rdev, rdev);
err = log_modify(conf, rdev, true);
goto out;
}
}
for (disk = first; disk <= last; disk++) {
p = conf->disks + disk;
tmp = rdev_mdlock_deref(mddev, p->rdev);
if (test_bit(WantReplacement, &tmp->flags) &&
mddev->reshape_position == MaxSector &&
p->replacement == NULL) {
clear_bit(In_sync, &rdev->flags);
set_bit(Replacement, &rdev->flags);
rdev->raid_disk = disk;
err = 0;
conf->fullsync = 1;
rcu_assign_pointer(p->replacement, rdev);
break;
}
}
out:
print_raid5_conf(conf);
return err;
}
static int raid5_resize(struct mddev *mddev, sector_t sectors)
{
/* no resync is happening, and there is enough space
* on all devices, so we can resize.
* We need to make sure resync covers any new space.
* If the array is shrinking we should possibly wait until
* any io in the removed space completes, but it hardly seems
* worth it.
*/
sector_t newsize;
struct r5conf *conf = mddev->private;
if (raid5_has_log(conf) || raid5_has_ppl(conf))
return -EINVAL;
sectors &= ~((sector_t)conf->chunk_sectors - 1);
newsize = raid5_size(mddev, sectors, mddev->raid_disks);
if (mddev->external_size &&
mddev->array_sectors > newsize)
return -EINVAL;
if (mddev->bitmap) {
int ret = md_bitmap_resize(mddev->bitmap, sectors, 0, 0);
if (ret)
return ret;
}
md_set_array_sectors(mddev, newsize);
if (sectors > mddev->dev_sectors &&
mddev->recovery_cp > mddev->dev_sectors) {
mddev->recovery_cp = mddev->dev_sectors;
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
}
mddev->dev_sectors = sectors;
mddev->resync_max_sectors = sectors;
return 0;
}
static int check_stripe_cache(struct mddev *mddev)
{
/* Can only proceed if there are plenty of stripe_heads.
* We need a minimum of one full stripe,, and for sensible progress
* it is best to have about 4 times that.
* If we require 4 times, then the default 256 4K stripe_heads will
* allow for chunk sizes up to 256K, which is probably OK.
* If the chunk size is greater, user-space should request more
* stripe_heads first.
*/
struct r5conf *conf = mddev->private;
if (((mddev->chunk_sectors << 9) / RAID5_STRIPE_SIZE(conf)) * 4
> conf->min_nr_stripes ||
((mddev->new_chunk_sectors << 9) / RAID5_STRIPE_SIZE(conf)) * 4
> conf->min_nr_stripes) {
pr_warn("md/raid:%s: reshape: not enough stripes. Needed %lu\n",
mdname(mddev),
((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9)
/ RAID5_STRIPE_SIZE(conf))*4);
return 0;
}
return 1;
}
static int check_reshape(struct mddev *mddev)
{
struct r5conf *conf = mddev->private;
if (raid5_has_log(conf) || raid5_has_ppl(conf))
return -EINVAL;
if (mddev->delta_disks == 0 &&
mddev->new_layout == mddev->layout &&
mddev->new_chunk_sectors == mddev->chunk_sectors)
return 0; /* nothing to do */
if (has_failed(conf))
return -EINVAL;
if (mddev->delta_disks < 0 && mddev->reshape_position == MaxSector) {
/* We might be able to shrink, but the devices must
* be made bigger first.
* For raid6, 4 is the minimum size.
* Otherwise 2 is the minimum
*/
int min = 2;
if (mddev->level == 6)
min = 4;
if (mddev->raid_disks + mddev->delta_disks < min)
return -EINVAL;
}
if (!check_stripe_cache(mddev))
return -ENOSPC;
if (mddev->new_chunk_sectors > mddev->chunk_sectors ||
mddev->delta_disks > 0)
if (resize_chunks(conf,
conf->previous_raid_disks
+ max(0, mddev->delta_disks),
max(mddev->new_chunk_sectors,
mddev->chunk_sectors)
) < 0)
return -ENOMEM;
if (conf->previous_raid_disks + mddev->delta_disks <= conf->pool_size)
return 0; /* never bother to shrink */
return resize_stripes(conf, (conf->previous_raid_disks
+ mddev->delta_disks));
}
static int raid5_start_reshape(struct mddev *mddev)
{
struct r5conf *conf = mddev->private;
struct md_rdev *rdev;
int spares = 0;
int i;
unsigned long flags;
if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
return -EBUSY;
if (!check_stripe_cache(mddev))
return -ENOSPC;
if (has_failed(conf))
return -EINVAL;
/* raid5 can't handle concurrent reshape and recovery */
if (mddev->recovery_cp < MaxSector)
return -EBUSY;
for (i = 0; i < conf->raid_disks; i++)
if (rdev_mdlock_deref(mddev, conf->disks[i].replacement))
return -EBUSY;
rdev_for_each(rdev, mddev) {
if (!test_bit(In_sync, &rdev->flags)
&& !test_bit(Faulty, &rdev->flags))
spares++;
}
if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
/* Not enough devices even to make a degraded array
* of that size
*/
return -EINVAL;
/* Refuse to reduce size of the array. Any reductions in
* array size must be through explicit setting of array_size
* attribute.
*/
if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks)
< mddev->array_sectors) {
pr_warn("md/raid:%s: array size must be reduced before number of disks\n",
mdname(mddev));
return -EINVAL;
}
atomic_set(&conf->reshape_stripes, 0);
spin_lock_irq(&conf->device_lock);
write_seqcount_begin(&conf->gen_lock);
conf->previous_raid_disks = conf->raid_disks;
conf->raid_disks += mddev->delta_disks;
conf->prev_chunk_sectors = conf->chunk_sectors;
conf->chunk_sectors = mddev->new_chunk_sectors;
conf->prev_algo = conf->algorithm;
conf->algorithm = mddev->new_layout;
conf->generation++;
/* Code that selects data_offset needs to see the generation update
* if reshape_progress has been set - so a memory barrier needed.
*/
smp_mb();
if (mddev->reshape_backwards)
conf->reshape_progress = raid5_size(mddev, 0, 0);
else
conf->reshape_progress = 0;
conf->reshape_safe = conf->reshape_progress;
write_seqcount_end(&conf->gen_lock);
spin_unlock_irq(&conf->device_lock);
/* Now make sure any requests that proceeded on the assumption
* the reshape wasn't running - like Discard or Read - have
* completed.
*/
mddev_suspend(mddev);
mddev_resume(mddev);
/* Add some new drives, as many as will fit.
* We know there are enough to make the newly sized array work.
* Don't add devices if we are reducing the number of
* devices in the array. This is because it is not possible
* to correctly record the "partially reconstructed" state of
* such devices during the reshape and confusion could result.
*/
if (mddev->delta_disks >= 0) {
rdev_for_each(rdev, mddev)
if (rdev->raid_disk < 0 &&
!test_bit(Faulty, &rdev->flags)) {
if (raid5_add_disk(mddev, rdev) == 0) {
if (rdev->raid_disk
>= conf->previous_raid_disks)
set_bit(In_sync, &rdev->flags);
else
rdev->recovery_offset = 0;
/* Failure here is OK */
sysfs_link_rdev(mddev, rdev);
}
} else if (rdev->raid_disk >= conf->previous_raid_disks
&& !test_bit(Faulty, &rdev->flags)) {
/* This is a spare that was manually added */
set_bit(In_sync, &rdev->flags);
}
/* When a reshape changes the number of devices,
* ->degraded is measured against the larger of the
* pre and post number of devices.
*/
spin_lock_irqsave(&conf->device_lock, flags);
mddev->degraded = raid5_calc_degraded(conf);
spin_unlock_irqrestore(&conf->device_lock, flags);
}
mddev->raid_disks = conf->raid_disks;
mddev->reshape_position = conf->reshape_progress;
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
rcu_assign_pointer(mddev->sync_thread,
md_register_thread(md_do_sync, mddev, "reshape"));
if (!mddev->sync_thread) {
mddev->recovery = 0;
spin_lock_irq(&conf->device_lock);
write_seqcount_begin(&conf->gen_lock);
mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
mddev->new_chunk_sectors =
conf->chunk_sectors = conf->prev_chunk_sectors;
mddev->new_layout = conf->algorithm = conf->prev_algo;
rdev_for_each(rdev, mddev)
rdev->new_data_offset = rdev->data_offset;
smp_wmb();
conf->generation --;
conf->reshape_progress = MaxSector;
mddev->reshape_position = MaxSector;
write_seqcount_end(&conf->gen_lock);
spin_unlock_irq(&conf->device_lock);
return -EAGAIN;
}
conf->reshape_checkpoint = jiffies;
md_wakeup_thread(mddev->sync_thread);
md_new_event();
return 0;
}
/* This is called from the reshape thread and should make any
* changes needed in 'conf'
*/
static void end_reshape(struct r5conf *conf)
{
if (!test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) {
struct md_rdev *rdev;
spin_lock_irq(&conf->device_lock);
conf->previous_raid_disks = conf->raid_disks;
md_finish_reshape(conf->mddev);
smp_wmb();
conf->reshape_progress = MaxSector;
conf->mddev->reshape_position = MaxSector;
rdev_for_each(rdev, conf->mddev)
if (rdev->raid_disk >= 0 &&
!test_bit(Journal, &rdev->flags) &&
!test_bit(In_sync, &rdev->flags))
rdev->recovery_offset = MaxSector;
spin_unlock_irq(&conf->device_lock);
wake_up(&conf->wait_for_overlap);
if (conf->mddev->queue)
raid5_set_io_opt(conf);
}
}
/* This is called from the raid5d thread with mddev_lock held.
* It makes config changes to the device.
*/
static void raid5_finish_reshape(struct mddev *mddev)
{
struct r5conf *conf = mddev->private;
struct md_rdev *rdev;
if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
if (mddev->delta_disks <= 0) {
int d;
spin_lock_irq(&conf->device_lock);
mddev->degraded = raid5_calc_degraded(conf);
spin_unlock_irq(&conf->device_lock);
for (d = conf->raid_disks ;
d < conf->raid_disks - mddev->delta_disks;
d++) {
rdev = rdev_mdlock_deref(mddev,
conf->disks[d].rdev);
if (rdev)
clear_bit(In_sync, &rdev->flags);
rdev = rdev_mdlock_deref(mddev,
conf->disks[d].replacement);
if (rdev)
clear_bit(In_sync, &rdev->flags);
}
}
mddev->layout = conf->algorithm;
mddev->chunk_sectors = conf->chunk_sectors;
mddev->reshape_position = MaxSector;
mddev->delta_disks = 0;
mddev->reshape_backwards = 0;
}
}
static void raid5_quiesce(struct mddev *mddev, int quiesce)
{
struct r5conf *conf = mddev->private;
if (quiesce) {
/* stop all writes */
lock_all_device_hash_locks_irq(conf);
/* '2' tells resync/reshape to pause so that all
* active stripes can drain
*/
r5c_flush_cache(conf, INT_MAX);
/* need a memory barrier to make sure read_one_chunk() sees
* quiesce started and reverts to slow (locked) path.
*/
smp_store_release(&conf->quiesce, 2);
wait_event_cmd(conf->wait_for_quiescent,
atomic_read(&conf->active_stripes) == 0 &&
atomic_read(&conf->active_aligned_reads) == 0,
unlock_all_device_hash_locks_irq(conf),
lock_all_device_hash_locks_irq(conf));
conf->quiesce = 1;
unlock_all_device_hash_locks_irq(conf);
/* allow reshape to continue */
wake_up(&conf->wait_for_overlap);
} else {
/* re-enable writes */
lock_all_device_hash_locks_irq(conf);
conf->quiesce = 0;
wake_up(&conf->wait_for_quiescent);
wake_up(&conf->wait_for_overlap);
unlock_all_device_hash_locks_irq(conf);
}
log_quiesce(conf, quiesce);
}
static void *raid45_takeover_raid0(struct mddev *mddev, int level)
{
struct r0conf *raid0_conf = mddev->private;
sector_t sectors;
/* for raid0 takeover only one zone is supported */
if (raid0_conf->nr_strip_zones > 1) {
pr_warn("md/raid:%s: cannot takeover raid0 with more than one zone.\n",
mdname(mddev));
return ERR_PTR(-EINVAL);
}
sectors = raid0_conf->strip_zone[0].zone_end;
sector_div(sectors, raid0_conf->strip_zone[0].nb_dev);
mddev->dev_sectors = sectors;
mddev->new_level = level;
mddev->new_layout = ALGORITHM_PARITY_N;
mddev->new_chunk_sectors = mddev->chunk_sectors;
mddev->raid_disks += 1;
mddev->delta_disks = 1;
/* make sure it will be not marked as dirty */
mddev->recovery_cp = MaxSector;
return setup_conf(mddev);
}
static void *raid5_takeover_raid1(struct mddev *mddev)
{
int chunksect;
void *ret;
if (mddev->raid_disks != 2 ||
mddev->degraded > 1)
return ERR_PTR(-EINVAL);
/* Should check if there are write-behind devices? */
chunksect = 64*2; /* 64K by default */
/* The array must be an exact multiple of chunksize */
while (chunksect && (mddev->array_sectors & (chunksect-1)))
chunksect >>= 1;
if ((chunksect<<9) < RAID5_STRIPE_SIZE((struct r5conf *)mddev->private))
/* array size does not allow a suitable chunk size */
return ERR_PTR(-EINVAL);
mddev->new_level = 5;
mddev->new_layout = ALGORITHM_LEFT_SYMMETRIC;
mddev->new_chunk_sectors = chunksect;
ret = setup_conf(mddev);
if (!IS_ERR(ret))
mddev_clear_unsupported_flags(mddev,
UNSUPPORTED_MDDEV_FLAGS);
return ret;
}
static void *raid5_takeover_raid6(struct mddev *mddev)
{
int new_layout;
switch (mddev->layout) {
case ALGORITHM_LEFT_ASYMMETRIC_6:
new_layout = ALGORITHM_LEFT_ASYMMETRIC;
break;
case ALGORITHM_RIGHT_ASYMMETRIC_6:
new_layout = ALGORITHM_RIGHT_ASYMMETRIC;
break;
case ALGORITHM_LEFT_SYMMETRIC_6:
new_layout = ALGORITHM_LEFT_SYMMETRIC;
break;
case ALGORITHM_RIGHT_SYMMETRIC_6:
new_layout = ALGORITHM_RIGHT_SYMMETRIC;
break;
case ALGORITHM_PARITY_0_6:
new_layout = ALGORITHM_PARITY_0;
break;
case ALGORITHM_PARITY_N:
new_layout = ALGORITHM_PARITY_N;
break;
default:
return ERR_PTR(-EINVAL);
}
mddev->new_level = 5;
mddev->new_layout = new_layout;
mddev->delta_disks = -1;
mddev->raid_disks -= 1;
return setup_conf(mddev);
}
static int raid5_check_reshape(struct mddev *mddev)
{
/* For a 2-drive array, the layout and chunk size can be changed
* immediately as not restriping is needed.
* For larger arrays we record the new value - after validation
* to be used by a reshape pass.
*/
struct r5conf *conf = mddev->private;
int new_chunk = mddev->new_chunk_sectors;
if (mddev->new_layout >= 0 && !algorithm_valid_raid5(mddev->new_layout))
return -EINVAL;
if (new_chunk > 0) {
if (!is_power_of_2(new_chunk))
return -EINVAL;
if (new_chunk < (PAGE_SIZE>>9))
return -EINVAL;
if (mddev->array_sectors & (new_chunk-1))
/* not factor of array size */
return -EINVAL;
}
/* They look valid */
if (mddev->raid_disks == 2) {
/* can make the change immediately */
if (mddev->new_layout >= 0) {
conf->algorithm = mddev->new_layout;
mddev->layout = mddev->new_layout;
}
if (new_chunk > 0) {
conf->chunk_sectors = new_chunk ;
mddev->chunk_sectors = new_chunk;
}
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
md_wakeup_thread(mddev->thread);
}
return check_reshape(mddev);
}
static int raid6_check_reshape(struct mddev *mddev)
{
int new_chunk = mddev->new_chunk_sectors;
if (mddev->new_layout >= 0 && !algorithm_valid_raid6(mddev->new_layout))
return -EINVAL;
if (new_chunk > 0) {
if (!is_power_of_2(new_chunk))
return -EINVAL;
if (new_chunk < (PAGE_SIZE >> 9))
return -EINVAL;
if (mddev->array_sectors & (new_chunk-1))
/* not factor of array size */
return -EINVAL;
}
/* They look valid */
return check_reshape(mddev);
}
static void *raid5_takeover(struct mddev *mddev)
{
/* raid5 can take over:
* raid0 - if there is only one strip zone - make it a raid4 layout
* raid1 - if there are two drives. We need to know the chunk size
* raid4 - trivial - just use a raid4 layout.
* raid6 - Providing it is a *_6 layout
*/
if (mddev->level == 0)
return raid45_takeover_raid0(mddev, 5);
if (mddev->level == 1)
return raid5_takeover_raid1(mddev);
if (mddev->level == 4) {
mddev->new_layout = ALGORITHM_PARITY_N;
mddev->new_level = 5;
return setup_conf(mddev);
}
if (mddev->level == 6)
return raid5_takeover_raid6(mddev);
return ERR_PTR(-EINVAL);
}
static void *raid4_takeover(struct mddev *mddev)
{
/* raid4 can take over:
* raid0 - if there is only one strip zone
* raid5 - if layout is right
*/
if (mddev->level == 0)
return raid45_takeover_raid0(mddev, 4);
if (mddev->level == 5 &&
mddev->layout == ALGORITHM_PARITY_N) {
mddev->new_layout = 0;
mddev->new_level = 4;
return setup_conf(mddev);
}
return ERR_PTR(-EINVAL);
}
static struct md_personality raid5_personality;
static void *raid6_takeover(struct mddev *mddev)
{
/* Currently can only take over a raid5. We map the
* personality to an equivalent raid6 personality
* with the Q block at the end.
*/
int new_layout;
if (mddev->pers != &raid5_personality)
return ERR_PTR(-EINVAL);
if (mddev->degraded > 1)
return ERR_PTR(-EINVAL);
if (mddev->raid_disks > 253)
return ERR_PTR(-EINVAL);
if (mddev->raid_disks < 3)
return ERR_PTR(-EINVAL);
switch (mddev->layout) {
case ALGORITHM_LEFT_ASYMMETRIC:
new_layout = ALGORITHM_LEFT_ASYMMETRIC_6;
break;
case ALGORITHM_RIGHT_ASYMMETRIC:
new_layout = ALGORITHM_RIGHT_ASYMMETRIC_6;
break;
case ALGORITHM_LEFT_SYMMETRIC:
new_layout = ALGORITHM_LEFT_SYMMETRIC_6;
break;
case ALGORITHM_RIGHT_SYMMETRIC:
new_layout = ALGORITHM_RIGHT_SYMMETRIC_6;
break;
case ALGORITHM_PARITY_0:
new_layout = ALGORITHM_PARITY_0_6;
break;
case ALGORITHM_PARITY_N:
new_layout = ALGORITHM_PARITY_N;
break;
default:
return ERR_PTR(-EINVAL);
}
mddev->new_level = 6;
mddev->new_layout = new_layout;
mddev->delta_disks = 1;
mddev->raid_disks += 1;
return setup_conf(mddev);
}
static int raid5_change_consistency_policy(struct mddev *mddev, const char *buf)
{
struct r5conf *conf;
int err;
err = mddev_lock(mddev);
if (err)
return err;
conf = mddev->private;
if (!conf) {
mddev_unlock(mddev);
return -ENODEV;
}
if (strncmp(buf, "ppl", 3) == 0) {
/* ppl only works with RAID 5 */
if (!raid5_has_ppl(conf) && conf->level == 5) {
err = log_init(conf, NULL, true);
if (!err) {
err = resize_stripes(conf, conf->pool_size);
if (err) {
mddev_suspend(mddev);
log_exit(conf);
mddev_resume(mddev);
}
}
} else
err = -EINVAL;
} else if (strncmp(buf, "resync", 6) == 0) {
if (raid5_has_ppl(conf)) {
mddev_suspend(mddev);
log_exit(conf);
mddev_resume(mddev);
err = resize_stripes(conf, conf->pool_size);
} else if (test_bit(MD_HAS_JOURNAL, &conf->mddev->flags) &&
r5l_log_disk_error(conf)) {
bool journal_dev_exists = false;
struct md_rdev *rdev;
rdev_for_each(rdev, mddev)
if (test_bit(Journal, &rdev->flags)) {
journal_dev_exists = true;
break;
}
if (!journal_dev_exists) {
mddev_suspend(mddev);
clear_bit(MD_HAS_JOURNAL, &mddev->flags);
mddev_resume(mddev);
} else /* need remove journal device first */
err = -EBUSY;
} else
err = -EINVAL;
} else {
err = -EINVAL;
}
if (!err)
md_update_sb(mddev, 1);
mddev_unlock(mddev);
return err;
}
static int raid5_start(struct mddev *mddev)
{
struct r5conf *conf = mddev->private;
return r5l_start(conf->log);
}
static void raid5_prepare_suspend(struct mddev *mddev)
{
struct r5conf *conf = mddev->private;
wait_event(mddev->sb_wait, !reshape_inprogress(mddev) ||
percpu_ref_is_zero(&mddev->active_io));
if (percpu_ref_is_zero(&mddev->active_io))
return;
/*
* Reshape is not in progress, and array is suspended, io that is
* waiting for reshpape can never be done.
*/
wake_up(&conf->wait_for_overlap);
}
static struct md_personality raid6_personality =
{
.name = "raid6",
.level = 6,
.owner = THIS_MODULE,
.make_request = raid5_make_request,
.run = raid5_run,
.start = raid5_start,
.free = raid5_free,
.status = raid5_status,
.error_handler = raid5_error,
.hot_add_disk = raid5_add_disk,
.hot_remove_disk= raid5_remove_disk,
.spare_active = raid5_spare_active,
.sync_request = raid5_sync_request,
.resize = raid5_resize,
.size = raid5_size,
.check_reshape = raid6_check_reshape,
.start_reshape = raid5_start_reshape,
.finish_reshape = raid5_finish_reshape,
.prepare_suspend = raid5_prepare_suspend,
.quiesce = raid5_quiesce,
.takeover = raid6_takeover,
.change_consistency_policy = raid5_change_consistency_policy,
};
static struct md_personality raid5_personality =
{
.name = "raid5",
.level = 5,
.owner = THIS_MODULE,
.make_request = raid5_make_request,
.run = raid5_run,
.start = raid5_start,
.free = raid5_free,
.status = raid5_status,
.error_handler = raid5_error,
.hot_add_disk = raid5_add_disk,
.hot_remove_disk= raid5_remove_disk,
.spare_active = raid5_spare_active,
.sync_request = raid5_sync_request,
.resize = raid5_resize,
.size = raid5_size,
.check_reshape = raid5_check_reshape,
.start_reshape = raid5_start_reshape,
.finish_reshape = raid5_finish_reshape,
.prepare_suspend = raid5_prepare_suspend,
.quiesce = raid5_quiesce,
.takeover = raid5_takeover,
.change_consistency_policy = raid5_change_consistency_policy,
};
static struct md_personality raid4_personality =
{
.name = "raid4",
.level = 4,
.owner = THIS_MODULE,
.make_request = raid5_make_request,
.run = raid5_run,
.start = raid5_start,
.free = raid5_free,
.status = raid5_status,
.error_handler = raid5_error,
.hot_add_disk = raid5_add_disk,
.hot_remove_disk= raid5_remove_disk,
.spare_active = raid5_spare_active,
.sync_request = raid5_sync_request,
.resize = raid5_resize,
.size = raid5_size,
.check_reshape = raid5_check_reshape,
.start_reshape = raid5_start_reshape,
.finish_reshape = raid5_finish_reshape,
.prepare_suspend = raid5_prepare_suspend,
.quiesce = raid5_quiesce,
.takeover = raid4_takeover,
.change_consistency_policy = raid5_change_consistency_policy,
};
static int __init raid5_init(void)
{
int ret;
raid5_wq = alloc_workqueue("raid5wq",
WQ_UNBOUND|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE|WQ_SYSFS, 0);
if (!raid5_wq)
return -ENOMEM;
ret = cpuhp_setup_state_multi(CPUHP_MD_RAID5_PREPARE,
"md/raid5:prepare",
raid456_cpu_up_prepare,
raid456_cpu_dead);
if (ret) {
destroy_workqueue(raid5_wq);
return ret;
}
register_md_personality(&raid6_personality);
register_md_personality(&raid5_personality);
register_md_personality(&raid4_personality);
return 0;
}
static void raid5_exit(void)
{
unregister_md_personality(&raid6_personality);
unregister_md_personality(&raid5_personality);
unregister_md_personality(&raid4_personality);
cpuhp_remove_multi_state(CPUHP_MD_RAID5_PREPARE);
destroy_workqueue(raid5_wq);
}
module_init(raid5_init);
module_exit(raid5_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("RAID4/5/6 (striping with parity) personality for MD");
MODULE_ALIAS("md-personality-4"); /* RAID5 */
MODULE_ALIAS("md-raid5");
MODULE_ALIAS("md-raid4");
MODULE_ALIAS("md-level-5");
MODULE_ALIAS("md-level-4");
MODULE_ALIAS("md-personality-8"); /* RAID6 */
MODULE_ALIAS("md-raid6");
MODULE_ALIAS("md-level-6");
/* This used to be two separate modules, they were: */
MODULE_ALIAS("raid5");
MODULE_ALIAS("raid6");
| linux-master | drivers/md/raid5.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2009-2011 Red Hat, Inc.
*
* Author: Mikulas Patocka <[email protected]>
*
* This file is released under the GPL.
*/
#include <linux/dm-bufio.h>
#include <linux/device-mapper.h>
#include <linux/dm-io.h>
#include <linux/slab.h>
#include <linux/sched/mm.h>
#include <linux/jiffies.h>
#include <linux/vmalloc.h>
#include <linux/shrinker.h>
#include <linux/module.h>
#include <linux/rbtree.h>
#include <linux/stacktrace.h>
#include <linux/jump_label.h>
#include "dm.h"
#define DM_MSG_PREFIX "bufio"
/*
* Memory management policy:
* Limit the number of buffers to DM_BUFIO_MEMORY_PERCENT of main memory
* or DM_BUFIO_VMALLOC_PERCENT of vmalloc memory (whichever is lower).
* Always allocate at least DM_BUFIO_MIN_BUFFERS buffers.
* Start background writeback when there are DM_BUFIO_WRITEBACK_PERCENT
* dirty buffers.
*/
#define DM_BUFIO_MIN_BUFFERS 8
#define DM_BUFIO_MEMORY_PERCENT 2
#define DM_BUFIO_VMALLOC_PERCENT 25
#define DM_BUFIO_WRITEBACK_RATIO 3
#define DM_BUFIO_LOW_WATERMARK_RATIO 16
/*
* Check buffer ages in this interval (seconds)
*/
#define DM_BUFIO_WORK_TIMER_SECS 30
/*
* Free buffers when they are older than this (seconds)
*/
#define DM_BUFIO_DEFAULT_AGE_SECS 300
/*
* The nr of bytes of cached data to keep around.
*/
#define DM_BUFIO_DEFAULT_RETAIN_BYTES (256 * 1024)
/*
* Align buffer writes to this boundary.
* Tests show that SSDs have the highest IOPS when using 4k writes.
*/
#define DM_BUFIO_WRITE_ALIGN 4096
/*
* dm_buffer->list_mode
*/
#define LIST_CLEAN 0
#define LIST_DIRTY 1
#define LIST_SIZE 2
/*--------------------------------------------------------------*/
/*
* Rather than use an LRU list, we use a clock algorithm where entries
* are held in a circular list. When an entry is 'hit' a reference bit
* is set. The least recently used entry is approximated by running a
* cursor around the list selecting unreferenced entries. Referenced
* entries have their reference bit cleared as the cursor passes them.
*/
struct lru_entry {
struct list_head list;
atomic_t referenced;
};
struct lru_iter {
struct lru *lru;
struct list_head list;
struct lru_entry *stop;
struct lru_entry *e;
};
struct lru {
struct list_head *cursor;
unsigned long count;
struct list_head iterators;
};
/*--------------*/
static void lru_init(struct lru *lru)
{
lru->cursor = NULL;
lru->count = 0;
INIT_LIST_HEAD(&lru->iterators);
}
static void lru_destroy(struct lru *lru)
{
WARN_ON_ONCE(lru->cursor);
WARN_ON_ONCE(!list_empty(&lru->iterators));
}
/*
* Insert a new entry into the lru.
*/
static void lru_insert(struct lru *lru, struct lru_entry *le)
{
/*
* Don't be tempted to set to 1, makes the lru aspect
* perform poorly.
*/
atomic_set(&le->referenced, 0);
if (lru->cursor) {
list_add_tail(&le->list, lru->cursor);
} else {
INIT_LIST_HEAD(&le->list);
lru->cursor = &le->list;
}
lru->count++;
}
/*--------------*/
/*
* Convert a list_head pointer to an lru_entry pointer.
*/
static inline struct lru_entry *to_le(struct list_head *l)
{
return container_of(l, struct lru_entry, list);
}
/*
* Initialize an lru_iter and add it to the list of cursors in the lru.
*/
static void lru_iter_begin(struct lru *lru, struct lru_iter *it)
{
it->lru = lru;
it->stop = lru->cursor ? to_le(lru->cursor->prev) : NULL;
it->e = lru->cursor ? to_le(lru->cursor) : NULL;
list_add(&it->list, &lru->iterators);
}
/*
* Remove an lru_iter from the list of cursors in the lru.
*/
static inline void lru_iter_end(struct lru_iter *it)
{
list_del(&it->list);
}
/* Predicate function type to be used with lru_iter_next */
typedef bool (*iter_predicate)(struct lru_entry *le, void *context);
/*
* Advance the cursor to the next entry that passes the
* predicate, and return that entry. Returns NULL if the
* iteration is complete.
*/
static struct lru_entry *lru_iter_next(struct lru_iter *it,
iter_predicate pred, void *context)
{
struct lru_entry *e;
while (it->e) {
e = it->e;
/* advance the cursor */
if (it->e == it->stop)
it->e = NULL;
else
it->e = to_le(it->e->list.next);
if (pred(e, context))
return e;
}
return NULL;
}
/*
* Invalidate a specific lru_entry and update all cursors in
* the lru accordingly.
*/
static void lru_iter_invalidate(struct lru *lru, struct lru_entry *e)
{
struct lru_iter *it;
list_for_each_entry(it, &lru->iterators, list) {
/* Move c->e forwards if necc. */
if (it->e == e) {
it->e = to_le(it->e->list.next);
if (it->e == e)
it->e = NULL;
}
/* Move it->stop backwards if necc. */
if (it->stop == e) {
it->stop = to_le(it->stop->list.prev);
if (it->stop == e)
it->stop = NULL;
}
}
}
/*--------------*/
/*
* Remove a specific entry from the lru.
*/
static void lru_remove(struct lru *lru, struct lru_entry *le)
{
lru_iter_invalidate(lru, le);
if (lru->count == 1) {
lru->cursor = NULL;
} else {
if (lru->cursor == &le->list)
lru->cursor = lru->cursor->next;
list_del(&le->list);
}
lru->count--;
}
/*
* Mark as referenced.
*/
static inline void lru_reference(struct lru_entry *le)
{
atomic_set(&le->referenced, 1);
}
/*--------------*/
/*
* Remove the least recently used entry (approx), that passes the predicate.
* Returns NULL on failure.
*/
enum evict_result {
ER_EVICT,
ER_DONT_EVICT,
ER_STOP, /* stop looking for something to evict */
};
typedef enum evict_result (*le_predicate)(struct lru_entry *le, void *context);
static struct lru_entry *lru_evict(struct lru *lru, le_predicate pred, void *context)
{
unsigned long tested = 0;
struct list_head *h = lru->cursor;
struct lru_entry *le;
if (!h)
return NULL;
/*
* In the worst case we have to loop around twice. Once to clear
* the reference flags, and then again to discover the predicate
* fails for all entries.
*/
while (tested < lru->count) {
le = container_of(h, struct lru_entry, list);
if (atomic_read(&le->referenced)) {
atomic_set(&le->referenced, 0);
} else {
tested++;
switch (pred(le, context)) {
case ER_EVICT:
/*
* Adjust the cursor, so we start the next
* search from here.
*/
lru->cursor = le->list.next;
lru_remove(lru, le);
return le;
case ER_DONT_EVICT:
break;
case ER_STOP:
lru->cursor = le->list.next;
return NULL;
}
}
h = h->next;
cond_resched();
}
return NULL;
}
/*--------------------------------------------------------------*/
/*
* Buffer state bits.
*/
#define B_READING 0
#define B_WRITING 1
#define B_DIRTY 2
/*
* Describes how the block was allocated:
* kmem_cache_alloc(), __get_free_pages() or vmalloc().
* See the comment at alloc_buffer_data.
*/
enum data_mode {
DATA_MODE_SLAB = 0,
DATA_MODE_GET_FREE_PAGES = 1,
DATA_MODE_VMALLOC = 2,
DATA_MODE_LIMIT = 3
};
struct dm_buffer {
/* protected by the locks in dm_buffer_cache */
struct rb_node node;
/* immutable, so don't need protecting */
sector_t block;
void *data;
unsigned char data_mode; /* DATA_MODE_* */
/*
* These two fields are used in isolation, so do not need
* a surrounding lock.
*/
atomic_t hold_count;
unsigned long last_accessed;
/*
* Everything else is protected by the mutex in
* dm_bufio_client
*/
unsigned long state;
struct lru_entry lru;
unsigned char list_mode; /* LIST_* */
blk_status_t read_error;
blk_status_t write_error;
unsigned int dirty_start;
unsigned int dirty_end;
unsigned int write_start;
unsigned int write_end;
struct list_head write_list;
struct dm_bufio_client *c;
void (*end_io)(struct dm_buffer *b, blk_status_t bs);
#ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
#define MAX_STACK 10
unsigned int stack_len;
unsigned long stack_entries[MAX_STACK];
#endif
};
/*--------------------------------------------------------------*/
/*
* The buffer cache manages buffers, particularly:
* - inc/dec of holder count
* - setting the last_accessed field
* - maintains clean/dirty state along with lru
* - selecting buffers that match predicates
*
* It does *not* handle:
* - allocation/freeing of buffers.
* - IO
* - Eviction or cache sizing.
*
* cache_get() and cache_put() are threadsafe, you do not need to
* protect these calls with a surrounding mutex. All the other
* methods are not threadsafe; they do use locking primitives, but
* only enough to ensure get/put are threadsafe.
*/
struct buffer_tree {
struct rw_semaphore lock;
struct rb_root root;
} ____cacheline_aligned_in_smp;
struct dm_buffer_cache {
struct lru lru[LIST_SIZE];
/*
* We spread entries across multiple trees to reduce contention
* on the locks.
*/
unsigned int num_locks;
struct buffer_tree trees[];
};
static inline unsigned int cache_index(sector_t block, unsigned int num_locks)
{
return dm_hash_locks_index(block, num_locks);
}
static inline void cache_read_lock(struct dm_buffer_cache *bc, sector_t block)
{
down_read(&bc->trees[cache_index(block, bc->num_locks)].lock);
}
static inline void cache_read_unlock(struct dm_buffer_cache *bc, sector_t block)
{
up_read(&bc->trees[cache_index(block, bc->num_locks)].lock);
}
static inline void cache_write_lock(struct dm_buffer_cache *bc, sector_t block)
{
down_write(&bc->trees[cache_index(block, bc->num_locks)].lock);
}
static inline void cache_write_unlock(struct dm_buffer_cache *bc, sector_t block)
{
up_write(&bc->trees[cache_index(block, bc->num_locks)].lock);
}
/*
* Sometimes we want to repeatedly get and drop locks as part of an iteration.
* This struct helps avoid redundant drop and gets of the same lock.
*/
struct lock_history {
struct dm_buffer_cache *cache;
bool write;
unsigned int previous;
unsigned int no_previous;
};
static void lh_init(struct lock_history *lh, struct dm_buffer_cache *cache, bool write)
{
lh->cache = cache;
lh->write = write;
lh->no_previous = cache->num_locks;
lh->previous = lh->no_previous;
}
static void __lh_lock(struct lock_history *lh, unsigned int index)
{
if (lh->write)
down_write(&lh->cache->trees[index].lock);
else
down_read(&lh->cache->trees[index].lock);
}
static void __lh_unlock(struct lock_history *lh, unsigned int index)
{
if (lh->write)
up_write(&lh->cache->trees[index].lock);
else
up_read(&lh->cache->trees[index].lock);
}
/*
* Make sure you call this since it will unlock the final lock.
*/
static void lh_exit(struct lock_history *lh)
{
if (lh->previous != lh->no_previous) {
__lh_unlock(lh, lh->previous);
lh->previous = lh->no_previous;
}
}
/*
* Named 'next' because there is no corresponding
* 'up/unlock' call since it's done automatically.
*/
static void lh_next(struct lock_history *lh, sector_t b)
{
unsigned int index = cache_index(b, lh->no_previous); /* no_previous is num_locks */
if (lh->previous != lh->no_previous) {
if (lh->previous != index) {
__lh_unlock(lh, lh->previous);
__lh_lock(lh, index);
lh->previous = index;
}
} else {
__lh_lock(lh, index);
lh->previous = index;
}
}
static inline struct dm_buffer *le_to_buffer(struct lru_entry *le)
{
return container_of(le, struct dm_buffer, lru);
}
static struct dm_buffer *list_to_buffer(struct list_head *l)
{
struct lru_entry *le = list_entry(l, struct lru_entry, list);
if (!le)
return NULL;
return le_to_buffer(le);
}
static void cache_init(struct dm_buffer_cache *bc, unsigned int num_locks)
{
unsigned int i;
bc->num_locks = num_locks;
for (i = 0; i < bc->num_locks; i++) {
init_rwsem(&bc->trees[i].lock);
bc->trees[i].root = RB_ROOT;
}
lru_init(&bc->lru[LIST_CLEAN]);
lru_init(&bc->lru[LIST_DIRTY]);
}
static void cache_destroy(struct dm_buffer_cache *bc)
{
unsigned int i;
for (i = 0; i < bc->num_locks; i++)
WARN_ON_ONCE(!RB_EMPTY_ROOT(&bc->trees[i].root));
lru_destroy(&bc->lru[LIST_CLEAN]);
lru_destroy(&bc->lru[LIST_DIRTY]);
}
/*--------------*/
/*
* not threadsafe, or racey depending how you look at it
*/
static inline unsigned long cache_count(struct dm_buffer_cache *bc, int list_mode)
{
return bc->lru[list_mode].count;
}
static inline unsigned long cache_total(struct dm_buffer_cache *bc)
{
return cache_count(bc, LIST_CLEAN) + cache_count(bc, LIST_DIRTY);
}
/*--------------*/
/*
* Gets a specific buffer, indexed by block.
* If the buffer is found then its holder count will be incremented and
* lru_reference will be called.
*
* threadsafe
*/
static struct dm_buffer *__cache_get(const struct rb_root *root, sector_t block)
{
struct rb_node *n = root->rb_node;
struct dm_buffer *b;
while (n) {
b = container_of(n, struct dm_buffer, node);
if (b->block == block)
return b;
n = block < b->block ? n->rb_left : n->rb_right;
}
return NULL;
}
static void __cache_inc_buffer(struct dm_buffer *b)
{
atomic_inc(&b->hold_count);
WRITE_ONCE(b->last_accessed, jiffies);
}
static struct dm_buffer *cache_get(struct dm_buffer_cache *bc, sector_t block)
{
struct dm_buffer *b;
cache_read_lock(bc, block);
b = __cache_get(&bc->trees[cache_index(block, bc->num_locks)].root, block);
if (b) {
lru_reference(&b->lru);
__cache_inc_buffer(b);
}
cache_read_unlock(bc, block);
return b;
}
/*--------------*/
/*
* Returns true if the hold count hits zero.
* threadsafe
*/
static bool cache_put(struct dm_buffer_cache *bc, struct dm_buffer *b)
{
bool r;
cache_read_lock(bc, b->block);
BUG_ON(!atomic_read(&b->hold_count));
r = atomic_dec_and_test(&b->hold_count);
cache_read_unlock(bc, b->block);
return r;
}
/*--------------*/
typedef enum evict_result (*b_predicate)(struct dm_buffer *, void *);
/*
* Evicts a buffer based on a predicate. The oldest buffer that
* matches the predicate will be selected. In addition to the
* predicate the hold_count of the selected buffer will be zero.
*/
struct evict_wrapper {
struct lock_history *lh;
b_predicate pred;
void *context;
};
/*
* Wraps the buffer predicate turning it into an lru predicate. Adds
* extra test for hold_count.
*/
static enum evict_result __evict_pred(struct lru_entry *le, void *context)
{
struct evict_wrapper *w = context;
struct dm_buffer *b = le_to_buffer(le);
lh_next(w->lh, b->block);
if (atomic_read(&b->hold_count))
return ER_DONT_EVICT;
return w->pred(b, w->context);
}
static struct dm_buffer *__cache_evict(struct dm_buffer_cache *bc, int list_mode,
b_predicate pred, void *context,
struct lock_history *lh)
{
struct evict_wrapper w = {.lh = lh, .pred = pred, .context = context};
struct lru_entry *le;
struct dm_buffer *b;
le = lru_evict(&bc->lru[list_mode], __evict_pred, &w);
if (!le)
return NULL;
b = le_to_buffer(le);
/* __evict_pred will have locked the appropriate tree. */
rb_erase(&b->node, &bc->trees[cache_index(b->block, bc->num_locks)].root);
return b;
}
static struct dm_buffer *cache_evict(struct dm_buffer_cache *bc, int list_mode,
b_predicate pred, void *context)
{
struct dm_buffer *b;
struct lock_history lh;
lh_init(&lh, bc, true);
b = __cache_evict(bc, list_mode, pred, context, &lh);
lh_exit(&lh);
return b;
}
/*--------------*/
/*
* Mark a buffer as clean or dirty. Not threadsafe.
*/
static void cache_mark(struct dm_buffer_cache *bc, struct dm_buffer *b, int list_mode)
{
cache_write_lock(bc, b->block);
if (list_mode != b->list_mode) {
lru_remove(&bc->lru[b->list_mode], &b->lru);
b->list_mode = list_mode;
lru_insert(&bc->lru[b->list_mode], &b->lru);
}
cache_write_unlock(bc, b->block);
}
/*--------------*/
/*
* Runs through the lru associated with 'old_mode', if the predicate matches then
* it moves them to 'new_mode'. Not threadsafe.
*/
static void __cache_mark_many(struct dm_buffer_cache *bc, int old_mode, int new_mode,
b_predicate pred, void *context, struct lock_history *lh)
{
struct lru_entry *le;
struct dm_buffer *b;
struct evict_wrapper w = {.lh = lh, .pred = pred, .context = context};
while (true) {
le = lru_evict(&bc->lru[old_mode], __evict_pred, &w);
if (!le)
break;
b = le_to_buffer(le);
b->list_mode = new_mode;
lru_insert(&bc->lru[b->list_mode], &b->lru);
}
}
static void cache_mark_many(struct dm_buffer_cache *bc, int old_mode, int new_mode,
b_predicate pred, void *context)
{
struct lock_history lh;
lh_init(&lh, bc, true);
__cache_mark_many(bc, old_mode, new_mode, pred, context, &lh);
lh_exit(&lh);
}
/*--------------*/
/*
* Iterates through all clean or dirty entries calling a function for each
* entry. The callback may terminate the iteration early. Not threadsafe.
*/
/*
* Iterator functions should return one of these actions to indicate
* how the iteration should proceed.
*/
enum it_action {
IT_NEXT,
IT_COMPLETE,
};
typedef enum it_action (*iter_fn)(struct dm_buffer *b, void *context);
static void __cache_iterate(struct dm_buffer_cache *bc, int list_mode,
iter_fn fn, void *context, struct lock_history *lh)
{
struct lru *lru = &bc->lru[list_mode];
struct lru_entry *le, *first;
if (!lru->cursor)
return;
first = le = to_le(lru->cursor);
do {
struct dm_buffer *b = le_to_buffer(le);
lh_next(lh, b->block);
switch (fn(b, context)) {
case IT_NEXT:
break;
case IT_COMPLETE:
return;
}
cond_resched();
le = to_le(le->list.next);
} while (le != first);
}
static void cache_iterate(struct dm_buffer_cache *bc, int list_mode,
iter_fn fn, void *context)
{
struct lock_history lh;
lh_init(&lh, bc, false);
__cache_iterate(bc, list_mode, fn, context, &lh);
lh_exit(&lh);
}
/*--------------*/
/*
* Passes ownership of the buffer to the cache. Returns false if the
* buffer was already present (in which case ownership does not pass).
* eg, a race with another thread.
*
* Holder count should be 1 on insertion.
*
* Not threadsafe.
*/
static bool __cache_insert(struct rb_root *root, struct dm_buffer *b)
{
struct rb_node **new = &root->rb_node, *parent = NULL;
struct dm_buffer *found;
while (*new) {
found = container_of(*new, struct dm_buffer, node);
if (found->block == b->block)
return false;
parent = *new;
new = b->block < found->block ?
&found->node.rb_left : &found->node.rb_right;
}
rb_link_node(&b->node, parent, new);
rb_insert_color(&b->node, root);
return true;
}
static bool cache_insert(struct dm_buffer_cache *bc, struct dm_buffer *b)
{
bool r;
if (WARN_ON_ONCE(b->list_mode >= LIST_SIZE))
return false;
cache_write_lock(bc, b->block);
BUG_ON(atomic_read(&b->hold_count) != 1);
r = __cache_insert(&bc->trees[cache_index(b->block, bc->num_locks)].root, b);
if (r)
lru_insert(&bc->lru[b->list_mode], &b->lru);
cache_write_unlock(bc, b->block);
return r;
}
/*--------------*/
/*
* Removes buffer from cache, ownership of the buffer passes back to the caller.
* Fails if the hold_count is not one (ie. the caller holds the only reference).
*
* Not threadsafe.
*/
static bool cache_remove(struct dm_buffer_cache *bc, struct dm_buffer *b)
{
bool r;
cache_write_lock(bc, b->block);
if (atomic_read(&b->hold_count) != 1) {
r = false;
} else {
r = true;
rb_erase(&b->node, &bc->trees[cache_index(b->block, bc->num_locks)].root);
lru_remove(&bc->lru[b->list_mode], &b->lru);
}
cache_write_unlock(bc, b->block);
return r;
}
/*--------------*/
typedef void (*b_release)(struct dm_buffer *);
static struct dm_buffer *__find_next(struct rb_root *root, sector_t block)
{
struct rb_node *n = root->rb_node;
struct dm_buffer *b;
struct dm_buffer *best = NULL;
while (n) {
b = container_of(n, struct dm_buffer, node);
if (b->block == block)
return b;
if (block <= b->block) {
n = n->rb_left;
best = b;
} else {
n = n->rb_right;
}
}
return best;
}
static void __remove_range(struct dm_buffer_cache *bc,
struct rb_root *root,
sector_t begin, sector_t end,
b_predicate pred, b_release release)
{
struct dm_buffer *b;
while (true) {
cond_resched();
b = __find_next(root, begin);
if (!b || (b->block >= end))
break;
begin = b->block + 1;
if (atomic_read(&b->hold_count))
continue;
if (pred(b, NULL) == ER_EVICT) {
rb_erase(&b->node, root);
lru_remove(&bc->lru[b->list_mode], &b->lru);
release(b);
}
}
}
static void cache_remove_range(struct dm_buffer_cache *bc,
sector_t begin, sector_t end,
b_predicate pred, b_release release)
{
unsigned int i;
for (i = 0; i < bc->num_locks; i++) {
down_write(&bc->trees[i].lock);
__remove_range(bc, &bc->trees[i].root, begin, end, pred, release);
up_write(&bc->trees[i].lock);
}
}
/*----------------------------------------------------------------*/
/*
* Linking of buffers:
* All buffers are linked to buffer_cache with their node field.
*
* Clean buffers that are not being written (B_WRITING not set)
* are linked to lru[LIST_CLEAN] with their lru_list field.
*
* Dirty and clean buffers that are being written are linked to
* lru[LIST_DIRTY] with their lru_list field. When the write
* finishes, the buffer cannot be relinked immediately (because we
* are in an interrupt context and relinking requires process
* context), so some clean-not-writing buffers can be held on
* dirty_lru too. They are later added to lru in the process
* context.
*/
struct dm_bufio_client {
struct block_device *bdev;
unsigned int block_size;
s8 sectors_per_block_bits;
bool no_sleep;
struct mutex lock;
spinlock_t spinlock;
int async_write_error;
void (*alloc_callback)(struct dm_buffer *buf);
void (*write_callback)(struct dm_buffer *buf);
struct kmem_cache *slab_buffer;
struct kmem_cache *slab_cache;
struct dm_io_client *dm_io;
struct list_head reserved_buffers;
unsigned int need_reserved_buffers;
unsigned int minimum_buffers;
sector_t start;
struct shrinker shrinker;
struct work_struct shrink_work;
atomic_long_t need_shrink;
wait_queue_head_t free_buffer_wait;
struct list_head client_list;
/*
* Used by global_cleanup to sort the clients list.
*/
unsigned long oldest_buffer;
struct dm_buffer_cache cache; /* must be last member */
};
static DEFINE_STATIC_KEY_FALSE(no_sleep_enabled);
/*----------------------------------------------------------------*/
#define dm_bufio_in_request() (!!current->bio_list)
static void dm_bufio_lock(struct dm_bufio_client *c)
{
if (static_branch_unlikely(&no_sleep_enabled) && c->no_sleep)
spin_lock_bh(&c->spinlock);
else
mutex_lock_nested(&c->lock, dm_bufio_in_request());
}
static void dm_bufio_unlock(struct dm_bufio_client *c)
{
if (static_branch_unlikely(&no_sleep_enabled) && c->no_sleep)
spin_unlock_bh(&c->spinlock);
else
mutex_unlock(&c->lock);
}
/*----------------------------------------------------------------*/
/*
* Default cache size: available memory divided by the ratio.
*/
static unsigned long dm_bufio_default_cache_size;
/*
* Total cache size set by the user.
*/
static unsigned long dm_bufio_cache_size;
/*
* A copy of dm_bufio_cache_size because dm_bufio_cache_size can change
* at any time. If it disagrees, the user has changed cache size.
*/
static unsigned long dm_bufio_cache_size_latch;
static DEFINE_SPINLOCK(global_spinlock);
/*
* Buffers are freed after this timeout
*/
static unsigned int dm_bufio_max_age = DM_BUFIO_DEFAULT_AGE_SECS;
static unsigned long dm_bufio_retain_bytes = DM_BUFIO_DEFAULT_RETAIN_BYTES;
static unsigned long dm_bufio_peak_allocated;
static unsigned long dm_bufio_allocated_kmem_cache;
static unsigned long dm_bufio_allocated_get_free_pages;
static unsigned long dm_bufio_allocated_vmalloc;
static unsigned long dm_bufio_current_allocated;
/*----------------------------------------------------------------*/
/*
* The current number of clients.
*/
static int dm_bufio_client_count;
/*
* The list of all clients.
*/
static LIST_HEAD(dm_bufio_all_clients);
/*
* This mutex protects dm_bufio_cache_size_latch and dm_bufio_client_count
*/
static DEFINE_MUTEX(dm_bufio_clients_lock);
static struct workqueue_struct *dm_bufio_wq;
static struct delayed_work dm_bufio_cleanup_old_work;
static struct work_struct dm_bufio_replacement_work;
#ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
static void buffer_record_stack(struct dm_buffer *b)
{
b->stack_len = stack_trace_save(b->stack_entries, MAX_STACK, 2);
}
#endif
/*----------------------------------------------------------------*/
static void adjust_total_allocated(struct dm_buffer *b, bool unlink)
{
unsigned char data_mode;
long diff;
static unsigned long * const class_ptr[DATA_MODE_LIMIT] = {
&dm_bufio_allocated_kmem_cache,
&dm_bufio_allocated_get_free_pages,
&dm_bufio_allocated_vmalloc,
};
data_mode = b->data_mode;
diff = (long)b->c->block_size;
if (unlink)
diff = -diff;
spin_lock(&global_spinlock);
*class_ptr[data_mode] += diff;
dm_bufio_current_allocated += diff;
if (dm_bufio_current_allocated > dm_bufio_peak_allocated)
dm_bufio_peak_allocated = dm_bufio_current_allocated;
if (!unlink) {
if (dm_bufio_current_allocated > dm_bufio_cache_size)
queue_work(dm_bufio_wq, &dm_bufio_replacement_work);
}
spin_unlock(&global_spinlock);
}
/*
* Change the number of clients and recalculate per-client limit.
*/
static void __cache_size_refresh(void)
{
if (WARN_ON(!mutex_is_locked(&dm_bufio_clients_lock)))
return;
if (WARN_ON(dm_bufio_client_count < 0))
return;
dm_bufio_cache_size_latch = READ_ONCE(dm_bufio_cache_size);
/*
* Use default if set to 0 and report the actual cache size used.
*/
if (!dm_bufio_cache_size_latch) {
(void)cmpxchg(&dm_bufio_cache_size, 0,
dm_bufio_default_cache_size);
dm_bufio_cache_size_latch = dm_bufio_default_cache_size;
}
}
/*
* Allocating buffer data.
*
* Small buffers are allocated with kmem_cache, to use space optimally.
*
* For large buffers, we choose between get_free_pages and vmalloc.
* Each has advantages and disadvantages.
*
* __get_free_pages can randomly fail if the memory is fragmented.
* __vmalloc won't randomly fail, but vmalloc space is limited (it may be
* as low as 128M) so using it for caching is not appropriate.
*
* If the allocation may fail we use __get_free_pages. Memory fragmentation
* won't have a fatal effect here, but it just causes flushes of some other
* buffers and more I/O will be performed. Don't use __get_free_pages if it
* always fails (i.e. order > MAX_ORDER).
*
* If the allocation shouldn't fail we use __vmalloc. This is only for the
* initial reserve allocation, so there's no risk of wasting all vmalloc
* space.
*/
static void *alloc_buffer_data(struct dm_bufio_client *c, gfp_t gfp_mask,
unsigned char *data_mode)
{
if (unlikely(c->slab_cache != NULL)) {
*data_mode = DATA_MODE_SLAB;
return kmem_cache_alloc(c->slab_cache, gfp_mask);
}
if (c->block_size <= KMALLOC_MAX_SIZE &&
gfp_mask & __GFP_NORETRY) {
*data_mode = DATA_MODE_GET_FREE_PAGES;
return (void *)__get_free_pages(gfp_mask,
c->sectors_per_block_bits - (PAGE_SHIFT - SECTOR_SHIFT));
}
*data_mode = DATA_MODE_VMALLOC;
return __vmalloc(c->block_size, gfp_mask);
}
/*
* Free buffer's data.
*/
static void free_buffer_data(struct dm_bufio_client *c,
void *data, unsigned char data_mode)
{
switch (data_mode) {
case DATA_MODE_SLAB:
kmem_cache_free(c->slab_cache, data);
break;
case DATA_MODE_GET_FREE_PAGES:
free_pages((unsigned long)data,
c->sectors_per_block_bits - (PAGE_SHIFT - SECTOR_SHIFT));
break;
case DATA_MODE_VMALLOC:
vfree(data);
break;
default:
DMCRIT("dm_bufio_free_buffer_data: bad data mode: %d",
data_mode);
BUG();
}
}
/*
* Allocate buffer and its data.
*/
static struct dm_buffer *alloc_buffer(struct dm_bufio_client *c, gfp_t gfp_mask)
{
struct dm_buffer *b = kmem_cache_alloc(c->slab_buffer, gfp_mask);
if (!b)
return NULL;
b->c = c;
b->data = alloc_buffer_data(c, gfp_mask, &b->data_mode);
if (!b->data) {
kmem_cache_free(c->slab_buffer, b);
return NULL;
}
adjust_total_allocated(b, false);
#ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
b->stack_len = 0;
#endif
return b;
}
/*
* Free buffer and its data.
*/
static void free_buffer(struct dm_buffer *b)
{
struct dm_bufio_client *c = b->c;
adjust_total_allocated(b, true);
free_buffer_data(c, b->data, b->data_mode);
kmem_cache_free(c->slab_buffer, b);
}
/*
*--------------------------------------------------------------------------
* Submit I/O on the buffer.
*
* Bio interface is faster but it has some problems:
* the vector list is limited (increasing this limit increases
* memory-consumption per buffer, so it is not viable);
*
* the memory must be direct-mapped, not vmalloced;
*
* If the buffer is small enough (up to DM_BUFIO_INLINE_VECS pages) and
* it is not vmalloced, try using the bio interface.
*
* If the buffer is big, if it is vmalloced or if the underlying device
* rejects the bio because it is too large, use dm-io layer to do the I/O.
* The dm-io layer splits the I/O into multiple requests, avoiding the above
* shortcomings.
*--------------------------------------------------------------------------
*/
/*
* dm-io completion routine. It just calls b->bio.bi_end_io, pretending
* that the request was handled directly with bio interface.
*/
static void dmio_complete(unsigned long error, void *context)
{
struct dm_buffer *b = context;
b->end_io(b, unlikely(error != 0) ? BLK_STS_IOERR : 0);
}
static void use_dmio(struct dm_buffer *b, enum req_op op, sector_t sector,
unsigned int n_sectors, unsigned int offset)
{
int r;
struct dm_io_request io_req = {
.bi_opf = op,
.notify.fn = dmio_complete,
.notify.context = b,
.client = b->c->dm_io,
};
struct dm_io_region region = {
.bdev = b->c->bdev,
.sector = sector,
.count = n_sectors,
};
if (b->data_mode != DATA_MODE_VMALLOC) {
io_req.mem.type = DM_IO_KMEM;
io_req.mem.ptr.addr = (char *)b->data + offset;
} else {
io_req.mem.type = DM_IO_VMA;
io_req.mem.ptr.vma = (char *)b->data + offset;
}
r = dm_io(&io_req, 1, ®ion, NULL);
if (unlikely(r))
b->end_io(b, errno_to_blk_status(r));
}
static void bio_complete(struct bio *bio)
{
struct dm_buffer *b = bio->bi_private;
blk_status_t status = bio->bi_status;
bio_uninit(bio);
kfree(bio);
b->end_io(b, status);
}
static void use_bio(struct dm_buffer *b, enum req_op op, sector_t sector,
unsigned int n_sectors, unsigned int offset)
{
struct bio *bio;
char *ptr;
unsigned int len;
bio = bio_kmalloc(1, GFP_NOWAIT | __GFP_NORETRY | __GFP_NOWARN);
if (!bio) {
use_dmio(b, op, sector, n_sectors, offset);
return;
}
bio_init(bio, b->c->bdev, bio->bi_inline_vecs, 1, op);
bio->bi_iter.bi_sector = sector;
bio->bi_end_io = bio_complete;
bio->bi_private = b;
ptr = (char *)b->data + offset;
len = n_sectors << SECTOR_SHIFT;
__bio_add_page(bio, virt_to_page(ptr), len, offset_in_page(ptr));
submit_bio(bio);
}
static inline sector_t block_to_sector(struct dm_bufio_client *c, sector_t block)
{
sector_t sector;
if (likely(c->sectors_per_block_bits >= 0))
sector = block << c->sectors_per_block_bits;
else
sector = block * (c->block_size >> SECTOR_SHIFT);
sector += c->start;
return sector;
}
static void submit_io(struct dm_buffer *b, enum req_op op,
void (*end_io)(struct dm_buffer *, blk_status_t))
{
unsigned int n_sectors;
sector_t sector;
unsigned int offset, end;
b->end_io = end_io;
sector = block_to_sector(b->c, b->block);
if (op != REQ_OP_WRITE) {
n_sectors = b->c->block_size >> SECTOR_SHIFT;
offset = 0;
} else {
if (b->c->write_callback)
b->c->write_callback(b);
offset = b->write_start;
end = b->write_end;
offset &= -DM_BUFIO_WRITE_ALIGN;
end += DM_BUFIO_WRITE_ALIGN - 1;
end &= -DM_BUFIO_WRITE_ALIGN;
if (unlikely(end > b->c->block_size))
end = b->c->block_size;
sector += offset >> SECTOR_SHIFT;
n_sectors = (end - offset) >> SECTOR_SHIFT;
}
if (b->data_mode != DATA_MODE_VMALLOC)
use_bio(b, op, sector, n_sectors, offset);
else
use_dmio(b, op, sector, n_sectors, offset);
}
/*
*--------------------------------------------------------------
* Writing dirty buffers
*--------------------------------------------------------------
*/
/*
* The endio routine for write.
*
* Set the error, clear B_WRITING bit and wake anyone who was waiting on
* it.
*/
static void write_endio(struct dm_buffer *b, blk_status_t status)
{
b->write_error = status;
if (unlikely(status)) {
struct dm_bufio_client *c = b->c;
(void)cmpxchg(&c->async_write_error, 0,
blk_status_to_errno(status));
}
BUG_ON(!test_bit(B_WRITING, &b->state));
smp_mb__before_atomic();
clear_bit(B_WRITING, &b->state);
smp_mb__after_atomic();
wake_up_bit(&b->state, B_WRITING);
}
/*
* Initiate a write on a dirty buffer, but don't wait for it.
*
* - If the buffer is not dirty, exit.
* - If there some previous write going on, wait for it to finish (we can't
* have two writes on the same buffer simultaneously).
* - Submit our write and don't wait on it. We set B_WRITING indicating
* that there is a write in progress.
*/
static void __write_dirty_buffer(struct dm_buffer *b,
struct list_head *write_list)
{
if (!test_bit(B_DIRTY, &b->state))
return;
clear_bit(B_DIRTY, &b->state);
wait_on_bit_lock_io(&b->state, B_WRITING, TASK_UNINTERRUPTIBLE);
b->write_start = b->dirty_start;
b->write_end = b->dirty_end;
if (!write_list)
submit_io(b, REQ_OP_WRITE, write_endio);
else
list_add_tail(&b->write_list, write_list);
}
static void __flush_write_list(struct list_head *write_list)
{
struct blk_plug plug;
blk_start_plug(&plug);
while (!list_empty(write_list)) {
struct dm_buffer *b =
list_entry(write_list->next, struct dm_buffer, write_list);
list_del(&b->write_list);
submit_io(b, REQ_OP_WRITE, write_endio);
cond_resched();
}
blk_finish_plug(&plug);
}
/*
* Wait until any activity on the buffer finishes. Possibly write the
* buffer if it is dirty. When this function finishes, there is no I/O
* running on the buffer and the buffer is not dirty.
*/
static void __make_buffer_clean(struct dm_buffer *b)
{
BUG_ON(atomic_read(&b->hold_count));
/* smp_load_acquire() pairs with read_endio()'s smp_mb__before_atomic() */
if (!smp_load_acquire(&b->state)) /* fast case */
return;
wait_on_bit_io(&b->state, B_READING, TASK_UNINTERRUPTIBLE);
__write_dirty_buffer(b, NULL);
wait_on_bit_io(&b->state, B_WRITING, TASK_UNINTERRUPTIBLE);
}
static enum evict_result is_clean(struct dm_buffer *b, void *context)
{
struct dm_bufio_client *c = context;
/* These should never happen */
if (WARN_ON_ONCE(test_bit(B_WRITING, &b->state)))
return ER_DONT_EVICT;
if (WARN_ON_ONCE(test_bit(B_DIRTY, &b->state)))
return ER_DONT_EVICT;
if (WARN_ON_ONCE(b->list_mode != LIST_CLEAN))
return ER_DONT_EVICT;
if (static_branch_unlikely(&no_sleep_enabled) && c->no_sleep &&
unlikely(test_bit(B_READING, &b->state)))
return ER_DONT_EVICT;
return ER_EVICT;
}
static enum evict_result is_dirty(struct dm_buffer *b, void *context)
{
/* These should never happen */
if (WARN_ON_ONCE(test_bit(B_READING, &b->state)))
return ER_DONT_EVICT;
if (WARN_ON_ONCE(b->list_mode != LIST_DIRTY))
return ER_DONT_EVICT;
return ER_EVICT;
}
/*
* Find some buffer that is not held by anybody, clean it, unlink it and
* return it.
*/
static struct dm_buffer *__get_unclaimed_buffer(struct dm_bufio_client *c)
{
struct dm_buffer *b;
b = cache_evict(&c->cache, LIST_CLEAN, is_clean, c);
if (b) {
/* this also waits for pending reads */
__make_buffer_clean(b);
return b;
}
if (static_branch_unlikely(&no_sleep_enabled) && c->no_sleep)
return NULL;
b = cache_evict(&c->cache, LIST_DIRTY, is_dirty, NULL);
if (b) {
__make_buffer_clean(b);
return b;
}
return NULL;
}
/*
* Wait until some other threads free some buffer or release hold count on
* some buffer.
*
* This function is entered with c->lock held, drops it and regains it
* before exiting.
*/
static void __wait_for_free_buffer(struct dm_bufio_client *c)
{
DECLARE_WAITQUEUE(wait, current);
add_wait_queue(&c->free_buffer_wait, &wait);
set_current_state(TASK_UNINTERRUPTIBLE);
dm_bufio_unlock(c);
/*
* It's possible to miss a wake up event since we don't always
* hold c->lock when wake_up is called. So we have a timeout here,
* just in case.
*/
io_schedule_timeout(5 * HZ);
remove_wait_queue(&c->free_buffer_wait, &wait);
dm_bufio_lock(c);
}
enum new_flag {
NF_FRESH = 0,
NF_READ = 1,
NF_GET = 2,
NF_PREFETCH = 3
};
/*
* Allocate a new buffer. If the allocation is not possible, wait until
* some other thread frees a buffer.
*
* May drop the lock and regain it.
*/
static struct dm_buffer *__alloc_buffer_wait_no_callback(struct dm_bufio_client *c, enum new_flag nf)
{
struct dm_buffer *b;
bool tried_noio_alloc = false;
/*
* dm-bufio is resistant to allocation failures (it just keeps
* one buffer reserved in cases all the allocations fail).
* So set flags to not try too hard:
* GFP_NOWAIT: don't wait; if we need to sleep we'll release our
* mutex and wait ourselves.
* __GFP_NORETRY: don't retry and rather return failure
* __GFP_NOMEMALLOC: don't use emergency reserves
* __GFP_NOWARN: don't print a warning in case of failure
*
* For debugging, if we set the cache size to 1, no new buffers will
* be allocated.
*/
while (1) {
if (dm_bufio_cache_size_latch != 1) {
b = alloc_buffer(c, GFP_NOWAIT | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
if (b)
return b;
}
if (nf == NF_PREFETCH)
return NULL;
if (dm_bufio_cache_size_latch != 1 && !tried_noio_alloc) {
dm_bufio_unlock(c);
b = alloc_buffer(c, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
dm_bufio_lock(c);
if (b)
return b;
tried_noio_alloc = true;
}
if (!list_empty(&c->reserved_buffers)) {
b = list_to_buffer(c->reserved_buffers.next);
list_del(&b->lru.list);
c->need_reserved_buffers++;
return b;
}
b = __get_unclaimed_buffer(c);
if (b)
return b;
__wait_for_free_buffer(c);
}
}
static struct dm_buffer *__alloc_buffer_wait(struct dm_bufio_client *c, enum new_flag nf)
{
struct dm_buffer *b = __alloc_buffer_wait_no_callback(c, nf);
if (!b)
return NULL;
if (c->alloc_callback)
c->alloc_callback(b);
return b;
}
/*
* Free a buffer and wake other threads waiting for free buffers.
*/
static void __free_buffer_wake(struct dm_buffer *b)
{
struct dm_bufio_client *c = b->c;
b->block = -1;
if (!c->need_reserved_buffers)
free_buffer(b);
else {
list_add(&b->lru.list, &c->reserved_buffers);
c->need_reserved_buffers--;
}
/*
* We hold the bufio lock here, so no one can add entries to the
* wait queue anyway.
*/
if (unlikely(waitqueue_active(&c->free_buffer_wait)))
wake_up(&c->free_buffer_wait);
}
static enum evict_result cleaned(struct dm_buffer *b, void *context)
{
if (WARN_ON_ONCE(test_bit(B_READING, &b->state)))
return ER_DONT_EVICT; /* should never happen */
if (test_bit(B_DIRTY, &b->state) || test_bit(B_WRITING, &b->state))
return ER_DONT_EVICT;
else
return ER_EVICT;
}
static void __move_clean_buffers(struct dm_bufio_client *c)
{
cache_mark_many(&c->cache, LIST_DIRTY, LIST_CLEAN, cleaned, NULL);
}
struct write_context {
int no_wait;
struct list_head *write_list;
};
static enum it_action write_one(struct dm_buffer *b, void *context)
{
struct write_context *wc = context;
if (wc->no_wait && test_bit(B_WRITING, &b->state))
return IT_COMPLETE;
__write_dirty_buffer(b, wc->write_list);
return IT_NEXT;
}
static void __write_dirty_buffers_async(struct dm_bufio_client *c, int no_wait,
struct list_head *write_list)
{
struct write_context wc = {.no_wait = no_wait, .write_list = write_list};
__move_clean_buffers(c);
cache_iterate(&c->cache, LIST_DIRTY, write_one, &wc);
}
/*
* Check if we're over watermark.
* If we are over threshold_buffers, start freeing buffers.
* If we're over "limit_buffers", block until we get under the limit.
*/
static void __check_watermark(struct dm_bufio_client *c,
struct list_head *write_list)
{
if (cache_count(&c->cache, LIST_DIRTY) >
cache_count(&c->cache, LIST_CLEAN) * DM_BUFIO_WRITEBACK_RATIO)
__write_dirty_buffers_async(c, 1, write_list);
}
/*
*--------------------------------------------------------------
* Getting a buffer
*--------------------------------------------------------------
*/
static void cache_put_and_wake(struct dm_bufio_client *c, struct dm_buffer *b)
{
/*
* Relying on waitqueue_active() is racey, but we sleep
* with schedule_timeout anyway.
*/
if (cache_put(&c->cache, b) &&
unlikely(waitqueue_active(&c->free_buffer_wait)))
wake_up(&c->free_buffer_wait);
}
/*
* This assumes you have already checked the cache to see if the buffer
* is already present (it will recheck after dropping the lock for allocation).
*/
static struct dm_buffer *__bufio_new(struct dm_bufio_client *c, sector_t block,
enum new_flag nf, int *need_submit,
struct list_head *write_list)
{
struct dm_buffer *b, *new_b = NULL;
*need_submit = 0;
/* This can't be called with NF_GET */
if (WARN_ON_ONCE(nf == NF_GET))
return NULL;
new_b = __alloc_buffer_wait(c, nf);
if (!new_b)
return NULL;
/*
* We've had a period where the mutex was unlocked, so need to
* recheck the buffer tree.
*/
b = cache_get(&c->cache, block);
if (b) {
__free_buffer_wake(new_b);
goto found_buffer;
}
__check_watermark(c, write_list);
b = new_b;
atomic_set(&b->hold_count, 1);
WRITE_ONCE(b->last_accessed, jiffies);
b->block = block;
b->read_error = 0;
b->write_error = 0;
b->list_mode = LIST_CLEAN;
if (nf == NF_FRESH)
b->state = 0;
else {
b->state = 1 << B_READING;
*need_submit = 1;
}
/*
* We mustn't insert into the cache until the B_READING state
* is set. Otherwise another thread could get it and use
* it before it had been read.
*/
cache_insert(&c->cache, b);
return b;
found_buffer:
if (nf == NF_PREFETCH) {
cache_put_and_wake(c, b);
return NULL;
}
/*
* Note: it is essential that we don't wait for the buffer to be
* read if dm_bufio_get function is used. Both dm_bufio_get and
* dm_bufio_prefetch can be used in the driver request routine.
* If the user called both dm_bufio_prefetch and dm_bufio_get on
* the same buffer, it would deadlock if we waited.
*/
if (nf == NF_GET && unlikely(test_bit_acquire(B_READING, &b->state))) {
cache_put_and_wake(c, b);
return NULL;
}
return b;
}
/*
* The endio routine for reading: set the error, clear the bit and wake up
* anyone waiting on the buffer.
*/
static void read_endio(struct dm_buffer *b, blk_status_t status)
{
b->read_error = status;
BUG_ON(!test_bit(B_READING, &b->state));
smp_mb__before_atomic();
clear_bit(B_READING, &b->state);
smp_mb__after_atomic();
wake_up_bit(&b->state, B_READING);
}
/*
* A common routine for dm_bufio_new and dm_bufio_read. Operation of these
* functions is similar except that dm_bufio_new doesn't read the
* buffer from the disk (assuming that the caller overwrites all the data
* and uses dm_bufio_mark_buffer_dirty to write new data back).
*/
static void *new_read(struct dm_bufio_client *c, sector_t block,
enum new_flag nf, struct dm_buffer **bp)
{
int need_submit = 0;
struct dm_buffer *b;
LIST_HEAD(write_list);
*bp = NULL;
/*
* Fast path, hopefully the block is already in the cache. No need
* to get the client lock for this.
*/
b = cache_get(&c->cache, block);
if (b) {
if (nf == NF_PREFETCH) {
cache_put_and_wake(c, b);
return NULL;
}
/*
* Note: it is essential that we don't wait for the buffer to be
* read if dm_bufio_get function is used. Both dm_bufio_get and
* dm_bufio_prefetch can be used in the driver request routine.
* If the user called both dm_bufio_prefetch and dm_bufio_get on
* the same buffer, it would deadlock if we waited.
*/
if (nf == NF_GET && unlikely(test_bit_acquire(B_READING, &b->state))) {
cache_put_and_wake(c, b);
return NULL;
}
}
if (!b) {
if (nf == NF_GET)
return NULL;
dm_bufio_lock(c);
b = __bufio_new(c, block, nf, &need_submit, &write_list);
dm_bufio_unlock(c);
}
#ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
if (b && (atomic_read(&b->hold_count) == 1))
buffer_record_stack(b);
#endif
__flush_write_list(&write_list);
if (!b)
return NULL;
if (need_submit)
submit_io(b, REQ_OP_READ, read_endio);
wait_on_bit_io(&b->state, B_READING, TASK_UNINTERRUPTIBLE);
if (b->read_error) {
int error = blk_status_to_errno(b->read_error);
dm_bufio_release(b);
return ERR_PTR(error);
}
*bp = b;
return b->data;
}
void *dm_bufio_get(struct dm_bufio_client *c, sector_t block,
struct dm_buffer **bp)
{
return new_read(c, block, NF_GET, bp);
}
EXPORT_SYMBOL_GPL(dm_bufio_get);
void *dm_bufio_read(struct dm_bufio_client *c, sector_t block,
struct dm_buffer **bp)
{
if (WARN_ON_ONCE(dm_bufio_in_request()))
return ERR_PTR(-EINVAL);
return new_read(c, block, NF_READ, bp);
}
EXPORT_SYMBOL_GPL(dm_bufio_read);
void *dm_bufio_new(struct dm_bufio_client *c, sector_t block,
struct dm_buffer **bp)
{
if (WARN_ON_ONCE(dm_bufio_in_request()))
return ERR_PTR(-EINVAL);
return new_read(c, block, NF_FRESH, bp);
}
EXPORT_SYMBOL_GPL(dm_bufio_new);
void dm_bufio_prefetch(struct dm_bufio_client *c,
sector_t block, unsigned int n_blocks)
{
struct blk_plug plug;
LIST_HEAD(write_list);
if (WARN_ON_ONCE(dm_bufio_in_request()))
return; /* should never happen */
blk_start_plug(&plug);
for (; n_blocks--; block++) {
int need_submit;
struct dm_buffer *b;
b = cache_get(&c->cache, block);
if (b) {
/* already in cache */
cache_put_and_wake(c, b);
continue;
}
dm_bufio_lock(c);
b = __bufio_new(c, block, NF_PREFETCH, &need_submit,
&write_list);
if (unlikely(!list_empty(&write_list))) {
dm_bufio_unlock(c);
blk_finish_plug(&plug);
__flush_write_list(&write_list);
blk_start_plug(&plug);
dm_bufio_lock(c);
}
if (unlikely(b != NULL)) {
dm_bufio_unlock(c);
if (need_submit)
submit_io(b, REQ_OP_READ, read_endio);
dm_bufio_release(b);
cond_resched();
if (!n_blocks)
goto flush_plug;
dm_bufio_lock(c);
}
dm_bufio_unlock(c);
}
flush_plug:
blk_finish_plug(&plug);
}
EXPORT_SYMBOL_GPL(dm_bufio_prefetch);
void dm_bufio_release(struct dm_buffer *b)
{
struct dm_bufio_client *c = b->c;
/*
* If there were errors on the buffer, and the buffer is not
* to be written, free the buffer. There is no point in caching
* invalid buffer.
*/
if ((b->read_error || b->write_error) &&
!test_bit_acquire(B_READING, &b->state) &&
!test_bit(B_WRITING, &b->state) &&
!test_bit(B_DIRTY, &b->state)) {
dm_bufio_lock(c);
/* cache remove can fail if there are other holders */
if (cache_remove(&c->cache, b)) {
__free_buffer_wake(b);
dm_bufio_unlock(c);
return;
}
dm_bufio_unlock(c);
}
cache_put_and_wake(c, b);
}
EXPORT_SYMBOL_GPL(dm_bufio_release);
void dm_bufio_mark_partial_buffer_dirty(struct dm_buffer *b,
unsigned int start, unsigned int end)
{
struct dm_bufio_client *c = b->c;
BUG_ON(start >= end);
BUG_ON(end > b->c->block_size);
dm_bufio_lock(c);
BUG_ON(test_bit(B_READING, &b->state));
if (!test_and_set_bit(B_DIRTY, &b->state)) {
b->dirty_start = start;
b->dirty_end = end;
cache_mark(&c->cache, b, LIST_DIRTY);
} else {
if (start < b->dirty_start)
b->dirty_start = start;
if (end > b->dirty_end)
b->dirty_end = end;
}
dm_bufio_unlock(c);
}
EXPORT_SYMBOL_GPL(dm_bufio_mark_partial_buffer_dirty);
void dm_bufio_mark_buffer_dirty(struct dm_buffer *b)
{
dm_bufio_mark_partial_buffer_dirty(b, 0, b->c->block_size);
}
EXPORT_SYMBOL_GPL(dm_bufio_mark_buffer_dirty);
void dm_bufio_write_dirty_buffers_async(struct dm_bufio_client *c)
{
LIST_HEAD(write_list);
if (WARN_ON_ONCE(dm_bufio_in_request()))
return; /* should never happen */
dm_bufio_lock(c);
__write_dirty_buffers_async(c, 0, &write_list);
dm_bufio_unlock(c);
__flush_write_list(&write_list);
}
EXPORT_SYMBOL_GPL(dm_bufio_write_dirty_buffers_async);
/*
* For performance, it is essential that the buffers are written asynchronously
* and simultaneously (so that the block layer can merge the writes) and then
* waited upon.
*
* Finally, we flush hardware disk cache.
*/
static bool is_writing(struct lru_entry *e, void *context)
{
struct dm_buffer *b = le_to_buffer(e);
return test_bit(B_WRITING, &b->state);
}
int dm_bufio_write_dirty_buffers(struct dm_bufio_client *c)
{
int a, f;
unsigned long nr_buffers;
struct lru_entry *e;
struct lru_iter it;
LIST_HEAD(write_list);
dm_bufio_lock(c);
__write_dirty_buffers_async(c, 0, &write_list);
dm_bufio_unlock(c);
__flush_write_list(&write_list);
dm_bufio_lock(c);
nr_buffers = cache_count(&c->cache, LIST_DIRTY);
lru_iter_begin(&c->cache.lru[LIST_DIRTY], &it);
while ((e = lru_iter_next(&it, is_writing, c))) {
struct dm_buffer *b = le_to_buffer(e);
__cache_inc_buffer(b);
BUG_ON(test_bit(B_READING, &b->state));
if (nr_buffers) {
nr_buffers--;
dm_bufio_unlock(c);
wait_on_bit_io(&b->state, B_WRITING, TASK_UNINTERRUPTIBLE);
dm_bufio_lock(c);
} else {
wait_on_bit_io(&b->state, B_WRITING, TASK_UNINTERRUPTIBLE);
}
if (!test_bit(B_DIRTY, &b->state) && !test_bit(B_WRITING, &b->state))
cache_mark(&c->cache, b, LIST_CLEAN);
cache_put_and_wake(c, b);
cond_resched();
}
lru_iter_end(&it);
wake_up(&c->free_buffer_wait);
dm_bufio_unlock(c);
a = xchg(&c->async_write_error, 0);
f = dm_bufio_issue_flush(c);
if (a)
return a;
return f;
}
EXPORT_SYMBOL_GPL(dm_bufio_write_dirty_buffers);
/*
* Use dm-io to send an empty barrier to flush the device.
*/
int dm_bufio_issue_flush(struct dm_bufio_client *c)
{
struct dm_io_request io_req = {
.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC,
.mem.type = DM_IO_KMEM,
.mem.ptr.addr = NULL,
.client = c->dm_io,
};
struct dm_io_region io_reg = {
.bdev = c->bdev,
.sector = 0,
.count = 0,
};
if (WARN_ON_ONCE(dm_bufio_in_request()))
return -EINVAL;
return dm_io(&io_req, 1, &io_reg, NULL);
}
EXPORT_SYMBOL_GPL(dm_bufio_issue_flush);
/*
* Use dm-io to send a discard request to flush the device.
*/
int dm_bufio_issue_discard(struct dm_bufio_client *c, sector_t block, sector_t count)
{
struct dm_io_request io_req = {
.bi_opf = REQ_OP_DISCARD | REQ_SYNC,
.mem.type = DM_IO_KMEM,
.mem.ptr.addr = NULL,
.client = c->dm_io,
};
struct dm_io_region io_reg = {
.bdev = c->bdev,
.sector = block_to_sector(c, block),
.count = block_to_sector(c, count),
};
if (WARN_ON_ONCE(dm_bufio_in_request()))
return -EINVAL; /* discards are optional */
return dm_io(&io_req, 1, &io_reg, NULL);
}
EXPORT_SYMBOL_GPL(dm_bufio_issue_discard);
static bool forget_buffer(struct dm_bufio_client *c, sector_t block)
{
struct dm_buffer *b;
b = cache_get(&c->cache, block);
if (b) {
if (likely(!smp_load_acquire(&b->state))) {
if (cache_remove(&c->cache, b))
__free_buffer_wake(b);
else
cache_put_and_wake(c, b);
} else {
cache_put_and_wake(c, b);
}
}
return b ? true : false;
}
/*
* Free the given buffer.
*
* This is just a hint, if the buffer is in use or dirty, this function
* does nothing.
*/
void dm_bufio_forget(struct dm_bufio_client *c, sector_t block)
{
dm_bufio_lock(c);
forget_buffer(c, block);
dm_bufio_unlock(c);
}
EXPORT_SYMBOL_GPL(dm_bufio_forget);
static enum evict_result idle(struct dm_buffer *b, void *context)
{
return b->state ? ER_DONT_EVICT : ER_EVICT;
}
void dm_bufio_forget_buffers(struct dm_bufio_client *c, sector_t block, sector_t n_blocks)
{
dm_bufio_lock(c);
cache_remove_range(&c->cache, block, block + n_blocks, idle, __free_buffer_wake);
dm_bufio_unlock(c);
}
EXPORT_SYMBOL_GPL(dm_bufio_forget_buffers);
void dm_bufio_set_minimum_buffers(struct dm_bufio_client *c, unsigned int n)
{
c->minimum_buffers = n;
}
EXPORT_SYMBOL_GPL(dm_bufio_set_minimum_buffers);
unsigned int dm_bufio_get_block_size(struct dm_bufio_client *c)
{
return c->block_size;
}
EXPORT_SYMBOL_GPL(dm_bufio_get_block_size);
sector_t dm_bufio_get_device_size(struct dm_bufio_client *c)
{
sector_t s = bdev_nr_sectors(c->bdev);
if (s >= c->start)
s -= c->start;
else
s = 0;
if (likely(c->sectors_per_block_bits >= 0))
s >>= c->sectors_per_block_bits;
else
sector_div(s, c->block_size >> SECTOR_SHIFT);
return s;
}
EXPORT_SYMBOL_GPL(dm_bufio_get_device_size);
struct dm_io_client *dm_bufio_get_dm_io_client(struct dm_bufio_client *c)
{
return c->dm_io;
}
EXPORT_SYMBOL_GPL(dm_bufio_get_dm_io_client);
sector_t dm_bufio_get_block_number(struct dm_buffer *b)
{
return b->block;
}
EXPORT_SYMBOL_GPL(dm_bufio_get_block_number);
void *dm_bufio_get_block_data(struct dm_buffer *b)
{
return b->data;
}
EXPORT_SYMBOL_GPL(dm_bufio_get_block_data);
void *dm_bufio_get_aux_data(struct dm_buffer *b)
{
return b + 1;
}
EXPORT_SYMBOL_GPL(dm_bufio_get_aux_data);
struct dm_bufio_client *dm_bufio_get_client(struct dm_buffer *b)
{
return b->c;
}
EXPORT_SYMBOL_GPL(dm_bufio_get_client);
static enum it_action warn_leak(struct dm_buffer *b, void *context)
{
bool *warned = context;
WARN_ON(!(*warned));
*warned = true;
DMERR("leaked buffer %llx, hold count %u, list %d",
(unsigned long long)b->block, atomic_read(&b->hold_count), b->list_mode);
#ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
stack_trace_print(b->stack_entries, b->stack_len, 1);
/* mark unclaimed to avoid WARN_ON at end of drop_buffers() */
atomic_set(&b->hold_count, 0);
#endif
return IT_NEXT;
}
static void drop_buffers(struct dm_bufio_client *c)
{
int i;
struct dm_buffer *b;
if (WARN_ON(dm_bufio_in_request()))
return; /* should never happen */
/*
* An optimization so that the buffers are not written one-by-one.
*/
dm_bufio_write_dirty_buffers_async(c);
dm_bufio_lock(c);
while ((b = __get_unclaimed_buffer(c)))
__free_buffer_wake(b);
for (i = 0; i < LIST_SIZE; i++) {
bool warned = false;
cache_iterate(&c->cache, i, warn_leak, &warned);
}
#ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
while ((b = __get_unclaimed_buffer(c)))
__free_buffer_wake(b);
#endif
for (i = 0; i < LIST_SIZE; i++)
WARN_ON(cache_count(&c->cache, i));
dm_bufio_unlock(c);
}
static unsigned long get_retain_buffers(struct dm_bufio_client *c)
{
unsigned long retain_bytes = READ_ONCE(dm_bufio_retain_bytes);
if (likely(c->sectors_per_block_bits >= 0))
retain_bytes >>= c->sectors_per_block_bits + SECTOR_SHIFT;
else
retain_bytes /= c->block_size;
return retain_bytes;
}
static void __scan(struct dm_bufio_client *c)
{
int l;
struct dm_buffer *b;
unsigned long freed = 0;
unsigned long retain_target = get_retain_buffers(c);
unsigned long count = cache_total(&c->cache);
for (l = 0; l < LIST_SIZE; l++) {
while (true) {
if (count - freed <= retain_target)
atomic_long_set(&c->need_shrink, 0);
if (!atomic_long_read(&c->need_shrink))
break;
b = cache_evict(&c->cache, l,
l == LIST_CLEAN ? is_clean : is_dirty, c);
if (!b)
break;
__make_buffer_clean(b);
__free_buffer_wake(b);
atomic_long_dec(&c->need_shrink);
freed++;
cond_resched();
}
}
}
static void shrink_work(struct work_struct *w)
{
struct dm_bufio_client *c = container_of(w, struct dm_bufio_client, shrink_work);
dm_bufio_lock(c);
__scan(c);
dm_bufio_unlock(c);
}
static unsigned long dm_bufio_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
{
struct dm_bufio_client *c;
c = container_of(shrink, struct dm_bufio_client, shrinker);
atomic_long_add(sc->nr_to_scan, &c->need_shrink);
queue_work(dm_bufio_wq, &c->shrink_work);
return sc->nr_to_scan;
}
static unsigned long dm_bufio_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
{
struct dm_bufio_client *c = container_of(shrink, struct dm_bufio_client, shrinker);
unsigned long count = cache_total(&c->cache);
unsigned long retain_target = get_retain_buffers(c);
unsigned long queued_for_cleanup = atomic_long_read(&c->need_shrink);
if (unlikely(count < retain_target))
count = 0;
else
count -= retain_target;
if (unlikely(count < queued_for_cleanup))
count = 0;
else
count -= queued_for_cleanup;
return count;
}
/*
* Create the buffering interface
*/
struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsigned int block_size,
unsigned int reserved_buffers, unsigned int aux_size,
void (*alloc_callback)(struct dm_buffer *),
void (*write_callback)(struct dm_buffer *),
unsigned int flags)
{
int r;
unsigned int num_locks;
struct dm_bufio_client *c;
char slab_name[27];
if (!block_size || block_size & ((1 << SECTOR_SHIFT) - 1)) {
DMERR("%s: block size not specified or is not multiple of 512b", __func__);
r = -EINVAL;
goto bad_client;
}
num_locks = dm_num_hash_locks();
c = kzalloc(sizeof(*c) + (num_locks * sizeof(struct buffer_tree)), GFP_KERNEL);
if (!c) {
r = -ENOMEM;
goto bad_client;
}
cache_init(&c->cache, num_locks);
c->bdev = bdev;
c->block_size = block_size;
if (is_power_of_2(block_size))
c->sectors_per_block_bits = __ffs(block_size) - SECTOR_SHIFT;
else
c->sectors_per_block_bits = -1;
c->alloc_callback = alloc_callback;
c->write_callback = write_callback;
if (flags & DM_BUFIO_CLIENT_NO_SLEEP) {
c->no_sleep = true;
static_branch_inc(&no_sleep_enabled);
}
mutex_init(&c->lock);
spin_lock_init(&c->spinlock);
INIT_LIST_HEAD(&c->reserved_buffers);
c->need_reserved_buffers = reserved_buffers;
dm_bufio_set_minimum_buffers(c, DM_BUFIO_MIN_BUFFERS);
init_waitqueue_head(&c->free_buffer_wait);
c->async_write_error = 0;
c->dm_io = dm_io_client_create();
if (IS_ERR(c->dm_io)) {
r = PTR_ERR(c->dm_io);
goto bad_dm_io;
}
if (block_size <= KMALLOC_MAX_SIZE &&
(block_size < PAGE_SIZE || !is_power_of_2(block_size))) {
unsigned int align = min(1U << __ffs(block_size), (unsigned int)PAGE_SIZE);
snprintf(slab_name, sizeof(slab_name), "dm_bufio_cache-%u", block_size);
c->slab_cache = kmem_cache_create(slab_name, block_size, align,
SLAB_RECLAIM_ACCOUNT, NULL);
if (!c->slab_cache) {
r = -ENOMEM;
goto bad;
}
}
if (aux_size)
snprintf(slab_name, sizeof(slab_name), "dm_bufio_buffer-%u", aux_size);
else
snprintf(slab_name, sizeof(slab_name), "dm_bufio_buffer");
c->slab_buffer = kmem_cache_create(slab_name, sizeof(struct dm_buffer) + aux_size,
0, SLAB_RECLAIM_ACCOUNT, NULL);
if (!c->slab_buffer) {
r = -ENOMEM;
goto bad;
}
while (c->need_reserved_buffers) {
struct dm_buffer *b = alloc_buffer(c, GFP_KERNEL);
if (!b) {
r = -ENOMEM;
goto bad;
}
__free_buffer_wake(b);
}
INIT_WORK(&c->shrink_work, shrink_work);
atomic_long_set(&c->need_shrink, 0);
c->shrinker.count_objects = dm_bufio_shrink_count;
c->shrinker.scan_objects = dm_bufio_shrink_scan;
c->shrinker.seeks = 1;
c->shrinker.batch = 0;
r = register_shrinker(&c->shrinker, "dm-bufio:(%u:%u)",
MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
if (r)
goto bad;
mutex_lock(&dm_bufio_clients_lock);
dm_bufio_client_count++;
list_add(&c->client_list, &dm_bufio_all_clients);
__cache_size_refresh();
mutex_unlock(&dm_bufio_clients_lock);
return c;
bad:
while (!list_empty(&c->reserved_buffers)) {
struct dm_buffer *b = list_to_buffer(c->reserved_buffers.next);
list_del(&b->lru.list);
free_buffer(b);
}
kmem_cache_destroy(c->slab_cache);
kmem_cache_destroy(c->slab_buffer);
dm_io_client_destroy(c->dm_io);
bad_dm_io:
mutex_destroy(&c->lock);
if (c->no_sleep)
static_branch_dec(&no_sleep_enabled);
kfree(c);
bad_client:
return ERR_PTR(r);
}
EXPORT_SYMBOL_GPL(dm_bufio_client_create);
/*
* Free the buffering interface.
* It is required that there are no references on any buffers.
*/
void dm_bufio_client_destroy(struct dm_bufio_client *c)
{
unsigned int i;
drop_buffers(c);
unregister_shrinker(&c->shrinker);
flush_work(&c->shrink_work);
mutex_lock(&dm_bufio_clients_lock);
list_del(&c->client_list);
dm_bufio_client_count--;
__cache_size_refresh();
mutex_unlock(&dm_bufio_clients_lock);
WARN_ON(c->need_reserved_buffers);
while (!list_empty(&c->reserved_buffers)) {
struct dm_buffer *b = list_to_buffer(c->reserved_buffers.next);
list_del(&b->lru.list);
free_buffer(b);
}
for (i = 0; i < LIST_SIZE; i++)
if (cache_count(&c->cache, i))
DMERR("leaked buffer count %d: %lu", i, cache_count(&c->cache, i));
for (i = 0; i < LIST_SIZE; i++)
WARN_ON(cache_count(&c->cache, i));
cache_destroy(&c->cache);
kmem_cache_destroy(c->slab_cache);
kmem_cache_destroy(c->slab_buffer);
dm_io_client_destroy(c->dm_io);
mutex_destroy(&c->lock);
if (c->no_sleep)
static_branch_dec(&no_sleep_enabled);
kfree(c);
}
EXPORT_SYMBOL_GPL(dm_bufio_client_destroy);
void dm_bufio_client_reset(struct dm_bufio_client *c)
{
drop_buffers(c);
flush_work(&c->shrink_work);
}
EXPORT_SYMBOL_GPL(dm_bufio_client_reset);
void dm_bufio_set_sector_offset(struct dm_bufio_client *c, sector_t start)
{
c->start = start;
}
EXPORT_SYMBOL_GPL(dm_bufio_set_sector_offset);
/*--------------------------------------------------------------*/
static unsigned int get_max_age_hz(void)
{
unsigned int max_age = READ_ONCE(dm_bufio_max_age);
if (max_age > UINT_MAX / HZ)
max_age = UINT_MAX / HZ;
return max_age * HZ;
}
static bool older_than(struct dm_buffer *b, unsigned long age_hz)
{
return time_after_eq(jiffies, READ_ONCE(b->last_accessed) + age_hz);
}
struct evict_params {
gfp_t gfp;
unsigned long age_hz;
/*
* This gets updated with the largest last_accessed (ie. most
* recently used) of the evicted buffers. It will not be reinitialised
* by __evict_many(), so you can use it across multiple invocations.
*/
unsigned long last_accessed;
};
/*
* We may not be able to evict this buffer if IO pending or the client
* is still using it.
*
* And if GFP_NOFS is used, we must not do any I/O because we hold
* dm_bufio_clients_lock and we would risk deadlock if the I/O gets
* rerouted to different bufio client.
*/
static enum evict_result select_for_evict(struct dm_buffer *b, void *context)
{
struct evict_params *params = context;
if (!(params->gfp & __GFP_FS) ||
(static_branch_unlikely(&no_sleep_enabled) && b->c->no_sleep)) {
if (test_bit_acquire(B_READING, &b->state) ||
test_bit(B_WRITING, &b->state) ||
test_bit(B_DIRTY, &b->state))
return ER_DONT_EVICT;
}
return older_than(b, params->age_hz) ? ER_EVICT : ER_STOP;
}
static unsigned long __evict_many(struct dm_bufio_client *c,
struct evict_params *params,
int list_mode, unsigned long max_count)
{
unsigned long count;
unsigned long last_accessed;
struct dm_buffer *b;
for (count = 0; count < max_count; count++) {
b = cache_evict(&c->cache, list_mode, select_for_evict, params);
if (!b)
break;
last_accessed = READ_ONCE(b->last_accessed);
if (time_after_eq(params->last_accessed, last_accessed))
params->last_accessed = last_accessed;
__make_buffer_clean(b);
__free_buffer_wake(b);
cond_resched();
}
return count;
}
static void evict_old_buffers(struct dm_bufio_client *c, unsigned long age_hz)
{
struct evict_params params = {.gfp = 0, .age_hz = age_hz, .last_accessed = 0};
unsigned long retain = get_retain_buffers(c);
unsigned long count;
LIST_HEAD(write_list);
dm_bufio_lock(c);
__check_watermark(c, &write_list);
if (unlikely(!list_empty(&write_list))) {
dm_bufio_unlock(c);
__flush_write_list(&write_list);
dm_bufio_lock(c);
}
count = cache_total(&c->cache);
if (count > retain)
__evict_many(c, ¶ms, LIST_CLEAN, count - retain);
dm_bufio_unlock(c);
}
static void cleanup_old_buffers(void)
{
unsigned long max_age_hz = get_max_age_hz();
struct dm_bufio_client *c;
mutex_lock(&dm_bufio_clients_lock);
__cache_size_refresh();
list_for_each_entry(c, &dm_bufio_all_clients, client_list)
evict_old_buffers(c, max_age_hz);
mutex_unlock(&dm_bufio_clients_lock);
}
static void work_fn(struct work_struct *w)
{
cleanup_old_buffers();
queue_delayed_work(dm_bufio_wq, &dm_bufio_cleanup_old_work,
DM_BUFIO_WORK_TIMER_SECS * HZ);
}
/*--------------------------------------------------------------*/
/*
* Global cleanup tries to evict the oldest buffers from across _all_
* the clients. It does this by repeatedly evicting a few buffers from
* the client that holds the oldest buffer. It's approximate, but hopefully
* good enough.
*/
static struct dm_bufio_client *__pop_client(void)
{
struct list_head *h;
if (list_empty(&dm_bufio_all_clients))
return NULL;
h = dm_bufio_all_clients.next;
list_del(h);
return container_of(h, struct dm_bufio_client, client_list);
}
/*
* Inserts the client in the global client list based on its
* 'oldest_buffer' field.
*/
static void __insert_client(struct dm_bufio_client *new_client)
{
struct dm_bufio_client *c;
struct list_head *h = dm_bufio_all_clients.next;
while (h != &dm_bufio_all_clients) {
c = container_of(h, struct dm_bufio_client, client_list);
if (time_after_eq(c->oldest_buffer, new_client->oldest_buffer))
break;
h = h->next;
}
list_add_tail(&new_client->client_list, h);
}
static unsigned long __evict_a_few(unsigned long nr_buffers)
{
unsigned long count;
struct dm_bufio_client *c;
struct evict_params params = {
.gfp = GFP_KERNEL,
.age_hz = 0,
/* set to jiffies in case there are no buffers in this client */
.last_accessed = jiffies
};
c = __pop_client();
if (!c)
return 0;
dm_bufio_lock(c);
count = __evict_many(c, ¶ms, LIST_CLEAN, nr_buffers);
dm_bufio_unlock(c);
if (count)
c->oldest_buffer = params.last_accessed;
__insert_client(c);
return count;
}
static void check_watermarks(void)
{
LIST_HEAD(write_list);
struct dm_bufio_client *c;
mutex_lock(&dm_bufio_clients_lock);
list_for_each_entry(c, &dm_bufio_all_clients, client_list) {
dm_bufio_lock(c);
__check_watermark(c, &write_list);
dm_bufio_unlock(c);
}
mutex_unlock(&dm_bufio_clients_lock);
__flush_write_list(&write_list);
}
static void evict_old(void)
{
unsigned long threshold = dm_bufio_cache_size -
dm_bufio_cache_size / DM_BUFIO_LOW_WATERMARK_RATIO;
mutex_lock(&dm_bufio_clients_lock);
while (dm_bufio_current_allocated > threshold) {
if (!__evict_a_few(64))
break;
cond_resched();
}
mutex_unlock(&dm_bufio_clients_lock);
}
static void do_global_cleanup(struct work_struct *w)
{
check_watermarks();
evict_old();
}
/*
*--------------------------------------------------------------
* Module setup
*--------------------------------------------------------------
*/
/*
* This is called only once for the whole dm_bufio module.
* It initializes memory limit.
*/
static int __init dm_bufio_init(void)
{
__u64 mem;
dm_bufio_allocated_kmem_cache = 0;
dm_bufio_allocated_get_free_pages = 0;
dm_bufio_allocated_vmalloc = 0;
dm_bufio_current_allocated = 0;
mem = (__u64)mult_frac(totalram_pages() - totalhigh_pages(),
DM_BUFIO_MEMORY_PERCENT, 100) << PAGE_SHIFT;
if (mem > ULONG_MAX)
mem = ULONG_MAX;
#ifdef CONFIG_MMU
if (mem > mult_frac(VMALLOC_TOTAL, DM_BUFIO_VMALLOC_PERCENT, 100))
mem = mult_frac(VMALLOC_TOTAL, DM_BUFIO_VMALLOC_PERCENT, 100);
#endif
dm_bufio_default_cache_size = mem;
mutex_lock(&dm_bufio_clients_lock);
__cache_size_refresh();
mutex_unlock(&dm_bufio_clients_lock);
dm_bufio_wq = alloc_workqueue("dm_bufio_cache", WQ_MEM_RECLAIM, 0);
if (!dm_bufio_wq)
return -ENOMEM;
INIT_DELAYED_WORK(&dm_bufio_cleanup_old_work, work_fn);
INIT_WORK(&dm_bufio_replacement_work, do_global_cleanup);
queue_delayed_work(dm_bufio_wq, &dm_bufio_cleanup_old_work,
DM_BUFIO_WORK_TIMER_SECS * HZ);
return 0;
}
/*
* This is called once when unloading the dm_bufio module.
*/
static void __exit dm_bufio_exit(void)
{
int bug = 0;
cancel_delayed_work_sync(&dm_bufio_cleanup_old_work);
destroy_workqueue(dm_bufio_wq);
if (dm_bufio_client_count) {
DMCRIT("%s: dm_bufio_client_count leaked: %d",
__func__, dm_bufio_client_count);
bug = 1;
}
if (dm_bufio_current_allocated) {
DMCRIT("%s: dm_bufio_current_allocated leaked: %lu",
__func__, dm_bufio_current_allocated);
bug = 1;
}
if (dm_bufio_allocated_get_free_pages) {
DMCRIT("%s: dm_bufio_allocated_get_free_pages leaked: %lu",
__func__, dm_bufio_allocated_get_free_pages);
bug = 1;
}
if (dm_bufio_allocated_vmalloc) {
DMCRIT("%s: dm_bufio_vmalloc leaked: %lu",
__func__, dm_bufio_allocated_vmalloc);
bug = 1;
}
WARN_ON(bug); /* leaks are not worth crashing the system */
}
module_init(dm_bufio_init)
module_exit(dm_bufio_exit)
module_param_named(max_cache_size_bytes, dm_bufio_cache_size, ulong, 0644);
MODULE_PARM_DESC(max_cache_size_bytes, "Size of metadata cache");
module_param_named(max_age_seconds, dm_bufio_max_age, uint, 0644);
MODULE_PARM_DESC(max_age_seconds, "Max age of a buffer in seconds");
module_param_named(retain_bytes, dm_bufio_retain_bytes, ulong, 0644);
MODULE_PARM_DESC(retain_bytes, "Try to keep at least this many bytes cached in memory");
module_param_named(peak_allocated_bytes, dm_bufio_peak_allocated, ulong, 0644);
MODULE_PARM_DESC(peak_allocated_bytes, "Tracks the maximum allocated memory");
module_param_named(allocated_kmem_cache_bytes, dm_bufio_allocated_kmem_cache, ulong, 0444);
MODULE_PARM_DESC(allocated_kmem_cache_bytes, "Memory allocated with kmem_cache_alloc");
module_param_named(allocated_get_free_pages_bytes, dm_bufio_allocated_get_free_pages, ulong, 0444);
MODULE_PARM_DESC(allocated_get_free_pages_bytes, "Memory allocated with get_free_pages");
module_param_named(allocated_vmalloc_bytes, dm_bufio_allocated_vmalloc, ulong, 0444);
MODULE_PARM_DESC(allocated_vmalloc_bytes, "Memory allocated with vmalloc");
module_param_named(current_allocated_bytes, dm_bufio_current_allocated, ulong, 0444);
MODULE_PARM_DESC(current_allocated_bytes, "Memory currently used by the cache");
MODULE_AUTHOR("Mikulas Patocka <[email protected]>");
MODULE_DESCRIPTION(DM_NAME " buffered I/O library");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-bufio.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2010-2011 Neil Brown
* Copyright (C) 2010-2018 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
#include <linux/slab.h>
#include <linux/module.h>
#include "md.h"
#include "raid1.h"
#include "raid5.h"
#include "raid10.h"
#include "md-bitmap.h"
#include <linux/device-mapper.h>
#define DM_MSG_PREFIX "raid"
#define MAX_RAID_DEVICES 253 /* md-raid kernel limit */
/*
* Minimum sectors of free reshape space per raid device
*/
#define MIN_FREE_RESHAPE_SPACE to_sector(4*4096)
/*
* Minimum journal space 4 MiB in sectors.
*/
#define MIN_RAID456_JOURNAL_SPACE (4*2048)
static bool devices_handle_discard_safely;
/*
* The following flags are used by dm-raid to set up the array state.
* They must be cleared before md_run is called.
*/
#define FirstUse 10 /* rdev flag */
struct raid_dev {
/*
* Two DM devices, one to hold metadata and one to hold the
* actual data/parity. The reason for this is to not confuse
* ti->len and give more flexibility in altering size and
* characteristics.
*
* While it is possible for this device to be associated
* with a different physical device than the data_dev, it
* is intended for it to be the same.
* |--------- Physical Device ---------|
* |- meta_dev -|------ data_dev ------|
*/
struct dm_dev *meta_dev;
struct dm_dev *data_dev;
struct md_rdev rdev;
};
/*
* Bits for establishing rs->ctr_flags
*
* 1 = no flag value
* 2 = flag with value
*/
#define __CTR_FLAG_SYNC 0 /* 1 */ /* Not with raid0! */
#define __CTR_FLAG_NOSYNC 1 /* 1 */ /* Not with raid0! */
#define __CTR_FLAG_REBUILD 2 /* 2 */ /* Not with raid0! */
#define __CTR_FLAG_DAEMON_SLEEP 3 /* 2 */ /* Not with raid0! */
#define __CTR_FLAG_MIN_RECOVERY_RATE 4 /* 2 */ /* Not with raid0! */
#define __CTR_FLAG_MAX_RECOVERY_RATE 5 /* 2 */ /* Not with raid0! */
#define __CTR_FLAG_MAX_WRITE_BEHIND 6 /* 2 */ /* Only with raid1! */
#define __CTR_FLAG_WRITE_MOSTLY 7 /* 2 */ /* Only with raid1! */
#define __CTR_FLAG_STRIPE_CACHE 8 /* 2 */ /* Only with raid4/5/6! */
#define __CTR_FLAG_REGION_SIZE 9 /* 2 */ /* Not with raid0! */
#define __CTR_FLAG_RAID10_COPIES 10 /* 2 */ /* Only with raid10 */
#define __CTR_FLAG_RAID10_FORMAT 11 /* 2 */ /* Only with raid10 */
/* New for v1.9.0 */
#define __CTR_FLAG_DELTA_DISKS 12 /* 2 */ /* Only with reshapable raid1/4/5/6/10! */
#define __CTR_FLAG_DATA_OFFSET 13 /* 2 */ /* Only with reshapable raid4/5/6/10! */
#define __CTR_FLAG_RAID10_USE_NEAR_SETS 14 /* 2 */ /* Only with raid10! */
/* New for v1.10.0 */
#define __CTR_FLAG_JOURNAL_DEV 15 /* 2 */ /* Only with raid4/5/6 (journal device)! */
/* New for v1.11.1 */
#define __CTR_FLAG_JOURNAL_MODE 16 /* 2 */ /* Only with raid4/5/6 (journal mode)! */
/*
* Flags for rs->ctr_flags field.
*/
#define CTR_FLAG_SYNC (1 << __CTR_FLAG_SYNC)
#define CTR_FLAG_NOSYNC (1 << __CTR_FLAG_NOSYNC)
#define CTR_FLAG_REBUILD (1 << __CTR_FLAG_REBUILD)
#define CTR_FLAG_DAEMON_SLEEP (1 << __CTR_FLAG_DAEMON_SLEEP)
#define CTR_FLAG_MIN_RECOVERY_RATE (1 << __CTR_FLAG_MIN_RECOVERY_RATE)
#define CTR_FLAG_MAX_RECOVERY_RATE (1 << __CTR_FLAG_MAX_RECOVERY_RATE)
#define CTR_FLAG_MAX_WRITE_BEHIND (1 << __CTR_FLAG_MAX_WRITE_BEHIND)
#define CTR_FLAG_WRITE_MOSTLY (1 << __CTR_FLAG_WRITE_MOSTLY)
#define CTR_FLAG_STRIPE_CACHE (1 << __CTR_FLAG_STRIPE_CACHE)
#define CTR_FLAG_REGION_SIZE (1 << __CTR_FLAG_REGION_SIZE)
#define CTR_FLAG_RAID10_COPIES (1 << __CTR_FLAG_RAID10_COPIES)
#define CTR_FLAG_RAID10_FORMAT (1 << __CTR_FLAG_RAID10_FORMAT)
#define CTR_FLAG_DELTA_DISKS (1 << __CTR_FLAG_DELTA_DISKS)
#define CTR_FLAG_DATA_OFFSET (1 << __CTR_FLAG_DATA_OFFSET)
#define CTR_FLAG_RAID10_USE_NEAR_SETS (1 << __CTR_FLAG_RAID10_USE_NEAR_SETS)
#define CTR_FLAG_JOURNAL_DEV (1 << __CTR_FLAG_JOURNAL_DEV)
#define CTR_FLAG_JOURNAL_MODE (1 << __CTR_FLAG_JOURNAL_MODE)
/*
* Definitions of various constructor flags to
* be used in checks of valid / invalid flags
* per raid level.
*/
/* Define all any sync flags */
#define CTR_FLAGS_ANY_SYNC (CTR_FLAG_SYNC | CTR_FLAG_NOSYNC)
/* Define flags for options without argument (e.g. 'nosync') */
#define CTR_FLAG_OPTIONS_NO_ARGS (CTR_FLAGS_ANY_SYNC | \
CTR_FLAG_RAID10_USE_NEAR_SETS)
/* Define flags for options with one argument (e.g. 'delta_disks +2') */
#define CTR_FLAG_OPTIONS_ONE_ARG (CTR_FLAG_REBUILD | \
CTR_FLAG_WRITE_MOSTLY | \
CTR_FLAG_DAEMON_SLEEP | \
CTR_FLAG_MIN_RECOVERY_RATE | \
CTR_FLAG_MAX_RECOVERY_RATE | \
CTR_FLAG_MAX_WRITE_BEHIND | \
CTR_FLAG_STRIPE_CACHE | \
CTR_FLAG_REGION_SIZE | \
CTR_FLAG_RAID10_COPIES | \
CTR_FLAG_RAID10_FORMAT | \
CTR_FLAG_DELTA_DISKS | \
CTR_FLAG_DATA_OFFSET | \
CTR_FLAG_JOURNAL_DEV | \
CTR_FLAG_JOURNAL_MODE)
/* Valid options definitions per raid level... */
/* "raid0" does only accept data offset */
#define RAID0_VALID_FLAGS (CTR_FLAG_DATA_OFFSET)
/* "raid1" does not accept stripe cache, data offset, delta_disks or any raid10 options */
#define RAID1_VALID_FLAGS (CTR_FLAGS_ANY_SYNC | \
CTR_FLAG_REBUILD | \
CTR_FLAG_WRITE_MOSTLY | \
CTR_FLAG_DAEMON_SLEEP | \
CTR_FLAG_MIN_RECOVERY_RATE | \
CTR_FLAG_MAX_RECOVERY_RATE | \
CTR_FLAG_MAX_WRITE_BEHIND | \
CTR_FLAG_REGION_SIZE | \
CTR_FLAG_DELTA_DISKS | \
CTR_FLAG_DATA_OFFSET)
/* "raid10" does not accept any raid1 or stripe cache options */
#define RAID10_VALID_FLAGS (CTR_FLAGS_ANY_SYNC | \
CTR_FLAG_REBUILD | \
CTR_FLAG_DAEMON_SLEEP | \
CTR_FLAG_MIN_RECOVERY_RATE | \
CTR_FLAG_MAX_RECOVERY_RATE | \
CTR_FLAG_REGION_SIZE | \
CTR_FLAG_RAID10_COPIES | \
CTR_FLAG_RAID10_FORMAT | \
CTR_FLAG_DELTA_DISKS | \
CTR_FLAG_DATA_OFFSET | \
CTR_FLAG_RAID10_USE_NEAR_SETS)
/*
* "raid4/5/6" do not accept any raid1 or raid10 specific options
*
* "raid6" does not accept "nosync", because it is not guaranteed
* that both parity and q-syndrome are being written properly with
* any writes
*/
#define RAID45_VALID_FLAGS (CTR_FLAGS_ANY_SYNC | \
CTR_FLAG_REBUILD | \
CTR_FLAG_DAEMON_SLEEP | \
CTR_FLAG_MIN_RECOVERY_RATE | \
CTR_FLAG_MAX_RECOVERY_RATE | \
CTR_FLAG_STRIPE_CACHE | \
CTR_FLAG_REGION_SIZE | \
CTR_FLAG_DELTA_DISKS | \
CTR_FLAG_DATA_OFFSET | \
CTR_FLAG_JOURNAL_DEV | \
CTR_FLAG_JOURNAL_MODE)
#define RAID6_VALID_FLAGS (CTR_FLAG_SYNC | \
CTR_FLAG_REBUILD | \
CTR_FLAG_DAEMON_SLEEP | \
CTR_FLAG_MIN_RECOVERY_RATE | \
CTR_FLAG_MAX_RECOVERY_RATE | \
CTR_FLAG_STRIPE_CACHE | \
CTR_FLAG_REGION_SIZE | \
CTR_FLAG_DELTA_DISKS | \
CTR_FLAG_DATA_OFFSET | \
CTR_FLAG_JOURNAL_DEV | \
CTR_FLAG_JOURNAL_MODE)
/* ...valid options definitions per raid level */
/*
* Flags for rs->runtime_flags field
* (RT_FLAG prefix meaning "runtime flag")
*
* These are all internal and used to define runtime state,
* e.g. to prevent another resume from preresume processing
* the raid set all over again.
*/
#define RT_FLAG_RS_PRERESUMED 0
#define RT_FLAG_RS_RESUMED 1
#define RT_FLAG_RS_BITMAP_LOADED 2
#define RT_FLAG_UPDATE_SBS 3
#define RT_FLAG_RESHAPE_RS 4
#define RT_FLAG_RS_SUSPENDED 5
#define RT_FLAG_RS_IN_SYNC 6
#define RT_FLAG_RS_RESYNCING 7
#define RT_FLAG_RS_GROW 8
/* Array elements of 64 bit needed for rebuild/failed disk bits */
#define DISKS_ARRAY_ELEMS ((MAX_RAID_DEVICES + (sizeof(uint64_t) * 8 - 1)) / sizeof(uint64_t) / 8)
/*
* raid set level, layout and chunk sectors backup/restore
*/
struct rs_layout {
int new_level;
int new_layout;
int new_chunk_sectors;
};
struct raid_set {
struct dm_target *ti;
uint32_t stripe_cache_entries;
unsigned long ctr_flags;
unsigned long runtime_flags;
uint64_t rebuild_disks[DISKS_ARRAY_ELEMS];
int raid_disks;
int delta_disks;
int data_offset;
int raid10_copies;
int requested_bitmap_chunk_sectors;
struct mddev md;
struct raid_type *raid_type;
sector_t array_sectors;
sector_t dev_sectors;
/* Optional raid4/5/6 journal device */
struct journal_dev {
struct dm_dev *dev;
struct md_rdev rdev;
int mode;
} journal_dev;
struct raid_dev dev[];
};
static void rs_config_backup(struct raid_set *rs, struct rs_layout *l)
{
struct mddev *mddev = &rs->md;
l->new_level = mddev->new_level;
l->new_layout = mddev->new_layout;
l->new_chunk_sectors = mddev->new_chunk_sectors;
}
static void rs_config_restore(struct raid_set *rs, struct rs_layout *l)
{
struct mddev *mddev = &rs->md;
mddev->new_level = l->new_level;
mddev->new_layout = l->new_layout;
mddev->new_chunk_sectors = l->new_chunk_sectors;
}
/* raid10 algorithms (i.e. formats) */
#define ALGORITHM_RAID10_DEFAULT 0
#define ALGORITHM_RAID10_NEAR 1
#define ALGORITHM_RAID10_OFFSET 2
#define ALGORITHM_RAID10_FAR 3
/* Supported raid types and properties. */
static struct raid_type {
const char *name; /* RAID algorithm. */
const char *descr; /* Descriptor text for logging. */
const unsigned int parity_devs; /* # of parity devices. */
const unsigned int minimal_devs;/* minimal # of devices in set. */
const unsigned int level; /* RAID level. */
const unsigned int algorithm; /* RAID algorithm. */
} raid_types[] = {
{"raid0", "raid0 (striping)", 0, 2, 0, 0 /* NONE */},
{"raid1", "raid1 (mirroring)", 0, 2, 1, 0 /* NONE */},
{"raid10_far", "raid10 far (striped mirrors)", 0, 2, 10, ALGORITHM_RAID10_FAR},
{"raid10_offset", "raid10 offset (striped mirrors)", 0, 2, 10, ALGORITHM_RAID10_OFFSET},
{"raid10_near", "raid10 near (striped mirrors)", 0, 2, 10, ALGORITHM_RAID10_NEAR},
{"raid10", "raid10 (striped mirrors)", 0, 2, 10, ALGORITHM_RAID10_DEFAULT},
{"raid4", "raid4 (dedicated first parity disk)", 1, 2, 5, ALGORITHM_PARITY_0}, /* raid4 layout = raid5_0 */
{"raid5_n", "raid5 (dedicated last parity disk)", 1, 2, 5, ALGORITHM_PARITY_N},
{"raid5_ls", "raid5 (left symmetric)", 1, 2, 5, ALGORITHM_LEFT_SYMMETRIC},
{"raid5_rs", "raid5 (right symmetric)", 1, 2, 5, ALGORITHM_RIGHT_SYMMETRIC},
{"raid5_la", "raid5 (left asymmetric)", 1, 2, 5, ALGORITHM_LEFT_ASYMMETRIC},
{"raid5_ra", "raid5 (right asymmetric)", 1, 2, 5, ALGORITHM_RIGHT_ASYMMETRIC},
{"raid6_zr", "raid6 (zero restart)", 2, 4, 6, ALGORITHM_ROTATING_ZERO_RESTART},
{"raid6_nr", "raid6 (N restart)", 2, 4, 6, ALGORITHM_ROTATING_N_RESTART},
{"raid6_nc", "raid6 (N continue)", 2, 4, 6, ALGORITHM_ROTATING_N_CONTINUE},
{"raid6_n_6", "raid6 (dedicated parity/Q n/6)", 2, 4, 6, ALGORITHM_PARITY_N_6},
{"raid6_ls_6", "raid6 (left symmetric dedicated Q 6)", 2, 4, 6, ALGORITHM_LEFT_SYMMETRIC_6},
{"raid6_rs_6", "raid6 (right symmetric dedicated Q 6)", 2, 4, 6, ALGORITHM_RIGHT_SYMMETRIC_6},
{"raid6_la_6", "raid6 (left asymmetric dedicated Q 6)", 2, 4, 6, ALGORITHM_LEFT_ASYMMETRIC_6},
{"raid6_ra_6", "raid6 (right asymmetric dedicated Q 6)", 2, 4, 6, ALGORITHM_RIGHT_ASYMMETRIC_6}
};
/* True, if @v is in inclusive range [@min, @max] */
static bool __within_range(long v, long min, long max)
{
return v >= min && v <= max;
}
/* All table line arguments are defined here */
static struct arg_name_flag {
const unsigned long flag;
const char *name;
} __arg_name_flags[] = {
{ CTR_FLAG_SYNC, "sync"},
{ CTR_FLAG_NOSYNC, "nosync"},
{ CTR_FLAG_REBUILD, "rebuild"},
{ CTR_FLAG_DAEMON_SLEEP, "daemon_sleep"},
{ CTR_FLAG_MIN_RECOVERY_RATE, "min_recovery_rate"},
{ CTR_FLAG_MAX_RECOVERY_RATE, "max_recovery_rate"},
{ CTR_FLAG_MAX_WRITE_BEHIND, "max_write_behind"},
{ CTR_FLAG_WRITE_MOSTLY, "write_mostly"},
{ CTR_FLAG_STRIPE_CACHE, "stripe_cache"},
{ CTR_FLAG_REGION_SIZE, "region_size"},
{ CTR_FLAG_RAID10_COPIES, "raid10_copies"},
{ CTR_FLAG_RAID10_FORMAT, "raid10_format"},
{ CTR_FLAG_DATA_OFFSET, "data_offset"},
{ CTR_FLAG_DELTA_DISKS, "delta_disks"},
{ CTR_FLAG_RAID10_USE_NEAR_SETS, "raid10_use_near_sets"},
{ CTR_FLAG_JOURNAL_DEV, "journal_dev" },
{ CTR_FLAG_JOURNAL_MODE, "journal_mode" },
};
/* Return argument name string for given @flag */
static const char *dm_raid_arg_name_by_flag(const uint32_t flag)
{
if (hweight32(flag) == 1) {
struct arg_name_flag *anf = __arg_name_flags + ARRAY_SIZE(__arg_name_flags);
while (anf-- > __arg_name_flags)
if (flag & anf->flag)
return anf->name;
} else
DMERR("%s called with more than one flag!", __func__);
return NULL;
}
/* Define correlation of raid456 journal cache modes and dm-raid target line parameters */
static struct {
const int mode;
const char *param;
} _raid456_journal_mode[] = {
{ R5C_JOURNAL_MODE_WRITE_THROUGH, "writethrough" },
{ R5C_JOURNAL_MODE_WRITE_BACK, "writeback" }
};
/* Return MD raid4/5/6 journal mode for dm @journal_mode one */
static int dm_raid_journal_mode_to_md(const char *mode)
{
int m = ARRAY_SIZE(_raid456_journal_mode);
while (m--)
if (!strcasecmp(mode, _raid456_journal_mode[m].param))
return _raid456_journal_mode[m].mode;
return -EINVAL;
}
/* Return dm-raid raid4/5/6 journal mode string for @mode */
static const char *md_journal_mode_to_dm_raid(const int mode)
{
int m = ARRAY_SIZE(_raid456_journal_mode);
while (m--)
if (mode == _raid456_journal_mode[m].mode)
return _raid456_journal_mode[m].param;
return "unknown";
}
/*
* Bool helpers to test for various raid levels of a raid set.
* It's level as reported by the superblock rather than
* the requested raid_type passed to the constructor.
*/
/* Return true, if raid set in @rs is raid0 */
static bool rs_is_raid0(struct raid_set *rs)
{
return !rs->md.level;
}
/* Return true, if raid set in @rs is raid1 */
static bool rs_is_raid1(struct raid_set *rs)
{
return rs->md.level == 1;
}
/* Return true, if raid set in @rs is raid10 */
static bool rs_is_raid10(struct raid_set *rs)
{
return rs->md.level == 10;
}
/* Return true, if raid set in @rs is level 6 */
static bool rs_is_raid6(struct raid_set *rs)
{
return rs->md.level == 6;
}
/* Return true, if raid set in @rs is level 4, 5 or 6 */
static bool rs_is_raid456(struct raid_set *rs)
{
return __within_range(rs->md.level, 4, 6);
}
/* Return true, if raid set in @rs is reshapable */
static bool __is_raid10_far(int layout);
static bool rs_is_reshapable(struct raid_set *rs)
{
return rs_is_raid456(rs) ||
(rs_is_raid10(rs) && !__is_raid10_far(rs->md.new_layout));
}
/* Return true, if raid set in @rs is recovering */
static bool rs_is_recovering(struct raid_set *rs)
{
return rs->md.recovery_cp < rs->md.dev_sectors;
}
/* Return true, if raid set in @rs is reshaping */
static bool rs_is_reshaping(struct raid_set *rs)
{
return rs->md.reshape_position != MaxSector;
}
/*
* bool helpers to test for various raid levels of a raid type @rt
*/
/* Return true, if raid type in @rt is raid0 */
static bool rt_is_raid0(struct raid_type *rt)
{
return !rt->level;
}
/* Return true, if raid type in @rt is raid1 */
static bool rt_is_raid1(struct raid_type *rt)
{
return rt->level == 1;
}
/* Return true, if raid type in @rt is raid10 */
static bool rt_is_raid10(struct raid_type *rt)
{
return rt->level == 10;
}
/* Return true, if raid type in @rt is raid4/5 */
static bool rt_is_raid45(struct raid_type *rt)
{
return __within_range(rt->level, 4, 5);
}
/* Return true, if raid type in @rt is raid6 */
static bool rt_is_raid6(struct raid_type *rt)
{
return rt->level == 6;
}
/* Return true, if raid type in @rt is raid4/5/6 */
static bool rt_is_raid456(struct raid_type *rt)
{
return __within_range(rt->level, 4, 6);
}
/* END: raid level bools */
/* Return valid ctr flags for the raid level of @rs */
static unsigned long __valid_flags(struct raid_set *rs)
{
if (rt_is_raid0(rs->raid_type))
return RAID0_VALID_FLAGS;
else if (rt_is_raid1(rs->raid_type))
return RAID1_VALID_FLAGS;
else if (rt_is_raid10(rs->raid_type))
return RAID10_VALID_FLAGS;
else if (rt_is_raid45(rs->raid_type))
return RAID45_VALID_FLAGS;
else if (rt_is_raid6(rs->raid_type))
return RAID6_VALID_FLAGS;
return 0;
}
/*
* Check for valid flags set on @rs
*
* Has to be called after parsing of the ctr flags!
*/
static int rs_check_for_valid_flags(struct raid_set *rs)
{
if (rs->ctr_flags & ~__valid_flags(rs)) {
rs->ti->error = "Invalid flags combination";
return -EINVAL;
}
return 0;
}
/* MD raid10 bit definitions and helpers */
#define RAID10_OFFSET (1 << 16) /* stripes with data copies area adjacent on devices */
#define RAID10_BROCKEN_USE_FAR_SETS (1 << 17) /* Broken in raid10.c: use sets instead of whole stripe rotation */
#define RAID10_USE_FAR_SETS (1 << 18) /* Use sets instead of whole stripe rotation */
#define RAID10_FAR_COPIES_SHIFT 8 /* raid10 # far copies shift (2nd byte of layout) */
/* Return md raid10 near copies for @layout */
static unsigned int __raid10_near_copies(int layout)
{
return layout & 0xFF;
}
/* Return md raid10 far copies for @layout */
static unsigned int __raid10_far_copies(int layout)
{
return __raid10_near_copies(layout >> RAID10_FAR_COPIES_SHIFT);
}
/* Return true if md raid10 offset for @layout */
static bool __is_raid10_offset(int layout)
{
return !!(layout & RAID10_OFFSET);
}
/* Return true if md raid10 near for @layout */
static bool __is_raid10_near(int layout)
{
return !__is_raid10_offset(layout) && __raid10_near_copies(layout) > 1;
}
/* Return true if md raid10 far for @layout */
static bool __is_raid10_far(int layout)
{
return !__is_raid10_offset(layout) && __raid10_far_copies(layout) > 1;
}
/* Return md raid10 layout string for @layout */
static const char *raid10_md_layout_to_format(int layout)
{
/*
* Bit 16 stands for "offset"
* (i.e. adjacent stripes hold copies)
*
* Refer to MD's raid10.c for details
*/
if (__is_raid10_offset(layout))
return "offset";
if (__raid10_near_copies(layout) > 1)
return "near";
if (__raid10_far_copies(layout) > 1)
return "far";
return "unknown";
}
/* Return md raid10 algorithm for @name */
static int raid10_name_to_format(const char *name)
{
if (!strcasecmp(name, "near"))
return ALGORITHM_RAID10_NEAR;
else if (!strcasecmp(name, "offset"))
return ALGORITHM_RAID10_OFFSET;
else if (!strcasecmp(name, "far"))
return ALGORITHM_RAID10_FAR;
return -EINVAL;
}
/* Return md raid10 copies for @layout */
static unsigned int raid10_md_layout_to_copies(int layout)
{
return max(__raid10_near_copies(layout), __raid10_far_copies(layout));
}
/* Return md raid10 format id for @format string */
static int raid10_format_to_md_layout(struct raid_set *rs,
unsigned int algorithm,
unsigned int copies)
{
unsigned int n = 1, f = 1, r = 0;
/*
* MD resilienece flaw:
*
* enabling use_far_sets for far/offset formats causes copies
* to be colocated on the same devs together with their origins!
*
* -> disable it for now in the definition above
*/
if (algorithm == ALGORITHM_RAID10_DEFAULT ||
algorithm == ALGORITHM_RAID10_NEAR)
n = copies;
else if (algorithm == ALGORITHM_RAID10_OFFSET) {
f = copies;
r = RAID10_OFFSET;
if (!test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags))
r |= RAID10_USE_FAR_SETS;
} else if (algorithm == ALGORITHM_RAID10_FAR) {
f = copies;
if (!test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags))
r |= RAID10_USE_FAR_SETS;
} else
return -EINVAL;
return r | (f << RAID10_FAR_COPIES_SHIFT) | n;
}
/* END: MD raid10 bit definitions and helpers */
/* Check for any of the raid10 algorithms */
static bool __got_raid10(struct raid_type *rtp, const int layout)
{
if (rtp->level == 10) {
switch (rtp->algorithm) {
case ALGORITHM_RAID10_DEFAULT:
case ALGORITHM_RAID10_NEAR:
return __is_raid10_near(layout);
case ALGORITHM_RAID10_OFFSET:
return __is_raid10_offset(layout);
case ALGORITHM_RAID10_FAR:
return __is_raid10_far(layout);
default:
break;
}
}
return false;
}
/* Return raid_type for @name */
static struct raid_type *get_raid_type(const char *name)
{
struct raid_type *rtp = raid_types + ARRAY_SIZE(raid_types);
while (rtp-- > raid_types)
if (!strcasecmp(rtp->name, name))
return rtp;
return NULL;
}
/* Return raid_type for @name based derived from @level and @layout */
static struct raid_type *get_raid_type_by_ll(const int level, const int layout)
{
struct raid_type *rtp = raid_types + ARRAY_SIZE(raid_types);
while (rtp-- > raid_types) {
/* RAID10 special checks based on @layout flags/properties */
if (rtp->level == level &&
(__got_raid10(rtp, layout) || rtp->algorithm == layout))
return rtp;
}
return NULL;
}
/* Adjust rdev sectors */
static void rs_set_rdev_sectors(struct raid_set *rs)
{
struct mddev *mddev = &rs->md;
struct md_rdev *rdev;
/*
* raid10 sets rdev->sector to the device size, which
* is unintended in case of out-of-place reshaping
*/
rdev_for_each(rdev, mddev)
if (!test_bit(Journal, &rdev->flags))
rdev->sectors = mddev->dev_sectors;
}
/*
* Change bdev capacity of @rs in case of a disk add/remove reshape
*/
static void rs_set_capacity(struct raid_set *rs)
{
struct gendisk *gendisk = dm_disk(dm_table_get_md(rs->ti->table));
set_capacity_and_notify(gendisk, rs->md.array_sectors);
}
/*
* Set the mddev properties in @rs to the current
* ones retrieved from the freshest superblock
*/
static void rs_set_cur(struct raid_set *rs)
{
struct mddev *mddev = &rs->md;
mddev->new_level = mddev->level;
mddev->new_layout = mddev->layout;
mddev->new_chunk_sectors = mddev->chunk_sectors;
}
/*
* Set the mddev properties in @rs to the new
* ones requested by the ctr
*/
static void rs_set_new(struct raid_set *rs)
{
struct mddev *mddev = &rs->md;
mddev->level = mddev->new_level;
mddev->layout = mddev->new_layout;
mddev->chunk_sectors = mddev->new_chunk_sectors;
mddev->raid_disks = rs->raid_disks;
mddev->delta_disks = 0;
}
static struct raid_set *raid_set_alloc(struct dm_target *ti, struct raid_type *raid_type,
unsigned int raid_devs)
{
unsigned int i;
struct raid_set *rs;
if (raid_devs <= raid_type->parity_devs) {
ti->error = "Insufficient number of devices";
return ERR_PTR(-EINVAL);
}
rs = kzalloc(struct_size(rs, dev, raid_devs), GFP_KERNEL);
if (!rs) {
ti->error = "Cannot allocate raid context";
return ERR_PTR(-ENOMEM);
}
mddev_init(&rs->md);
rs->raid_disks = raid_devs;
rs->delta_disks = 0;
rs->ti = ti;
rs->raid_type = raid_type;
rs->stripe_cache_entries = 256;
rs->md.raid_disks = raid_devs;
rs->md.level = raid_type->level;
rs->md.new_level = rs->md.level;
rs->md.layout = raid_type->algorithm;
rs->md.new_layout = rs->md.layout;
rs->md.delta_disks = 0;
rs->md.recovery_cp = MaxSector;
for (i = 0; i < raid_devs; i++)
md_rdev_init(&rs->dev[i].rdev);
/*
* Remaining items to be initialized by further RAID params:
* rs->md.persistent
* rs->md.external
* rs->md.chunk_sectors
* rs->md.new_chunk_sectors
* rs->md.dev_sectors
*/
return rs;
}
/* Free all @rs allocations */
static void raid_set_free(struct raid_set *rs)
{
int i;
if (rs->journal_dev.dev) {
md_rdev_clear(&rs->journal_dev.rdev);
dm_put_device(rs->ti, rs->journal_dev.dev);
}
for (i = 0; i < rs->raid_disks; i++) {
if (rs->dev[i].meta_dev)
dm_put_device(rs->ti, rs->dev[i].meta_dev);
md_rdev_clear(&rs->dev[i].rdev);
if (rs->dev[i].data_dev)
dm_put_device(rs->ti, rs->dev[i].data_dev);
}
kfree(rs);
}
/*
* For every device we have two words
* <meta_dev>: meta device name or '-' if missing
* <data_dev>: data device name or '-' if missing
*
* The following are permitted:
* - -
* - <data_dev>
* <meta_dev> <data_dev>
*
* The following is not allowed:
* <meta_dev> -
*
* This code parses those words. If there is a failure,
* the caller must use raid_set_free() to unwind the operations.
*/
static int parse_dev_params(struct raid_set *rs, struct dm_arg_set *as)
{
int i;
int rebuild = 0;
int metadata_available = 0;
int r = 0;
const char *arg;
/* Put off the number of raid devices argument to get to dev pairs */
arg = dm_shift_arg(as);
if (!arg)
return -EINVAL;
for (i = 0; i < rs->raid_disks; i++) {
rs->dev[i].rdev.raid_disk = i;
rs->dev[i].meta_dev = NULL;
rs->dev[i].data_dev = NULL;
/*
* There are no offsets initially.
* Out of place reshape will set them accordingly.
*/
rs->dev[i].rdev.data_offset = 0;
rs->dev[i].rdev.new_data_offset = 0;
rs->dev[i].rdev.mddev = &rs->md;
arg = dm_shift_arg(as);
if (!arg)
return -EINVAL;
if (strcmp(arg, "-")) {
r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
&rs->dev[i].meta_dev);
if (r) {
rs->ti->error = "RAID metadata device lookup failure";
return r;
}
rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
if (!rs->dev[i].rdev.sb_page) {
rs->ti->error = "Failed to allocate superblock page";
return -ENOMEM;
}
}
arg = dm_shift_arg(as);
if (!arg)
return -EINVAL;
if (!strcmp(arg, "-")) {
if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
(!rs->dev[i].rdev.recovery_offset)) {
rs->ti->error = "Drive designated for rebuild not specified";
return -EINVAL;
}
if (rs->dev[i].meta_dev) {
rs->ti->error = "No data device supplied with metadata device";
return -EINVAL;
}
continue;
}
r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
&rs->dev[i].data_dev);
if (r) {
rs->ti->error = "RAID device lookup failure";
return r;
}
if (rs->dev[i].meta_dev) {
metadata_available = 1;
rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
}
rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
list_add_tail(&rs->dev[i].rdev.same_set, &rs->md.disks);
if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
rebuild++;
}
if (rs->journal_dev.dev)
list_add_tail(&rs->journal_dev.rdev.same_set, &rs->md.disks);
if (metadata_available) {
rs->md.external = 0;
rs->md.persistent = 1;
rs->md.major_version = 2;
} else if (rebuild && !rs->md.recovery_cp) {
/*
* Without metadata, we will not be able to tell if the array
* is in-sync or not - we must assume it is not. Therefore,
* it is impossible to rebuild a drive.
*
* Even if there is metadata, the on-disk information may
* indicate that the array is not in-sync and it will then
* fail at that time.
*
* User could specify 'nosync' option if desperate.
*/
rs->ti->error = "Unable to rebuild drive while array is not in-sync";
return -EINVAL;
}
return 0;
}
/*
* validate_region_size
* @rs
* @region_size: region size in sectors. If 0, pick a size (4MiB default).
*
* Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
* Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
*
* Returns: 0 on success, -EINVAL on failure.
*/
static int validate_region_size(struct raid_set *rs, unsigned long region_size)
{
unsigned long min_region_size = rs->ti->len / (1 << 21);
if (rs_is_raid0(rs))
return 0;
if (!region_size) {
/*
* Choose a reasonable default. All figures in sectors.
*/
if (min_region_size > (1 << 13)) {
/* If not a power of 2, make it the next power of 2 */
region_size = roundup_pow_of_two(min_region_size);
DMINFO("Choosing default region size of %lu sectors",
region_size);
} else {
DMINFO("Choosing default region size of 4MiB");
region_size = 1 << 13; /* sectors */
}
} else {
/*
* Validate user-supplied value.
*/
if (region_size > rs->ti->len) {
rs->ti->error = "Supplied region size is too large";
return -EINVAL;
}
if (region_size < min_region_size) {
DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
region_size, min_region_size);
rs->ti->error = "Supplied region size is too small";
return -EINVAL;
}
if (!is_power_of_2(region_size)) {
rs->ti->error = "Region size is not a power of 2";
return -EINVAL;
}
if (region_size < rs->md.chunk_sectors) {
rs->ti->error = "Region size is smaller than the chunk size";
return -EINVAL;
}
}
/*
* Convert sectors to bytes.
*/
rs->md.bitmap_info.chunksize = to_bytes(region_size);
return 0;
}
/*
* validate_raid_redundancy
* @rs
*
* Determine if there are enough devices in the array that haven't
* failed (or are being rebuilt) to form a usable array.
*
* Returns: 0 on success, -EINVAL on failure.
*/
static int validate_raid_redundancy(struct raid_set *rs)
{
unsigned int i, rebuild_cnt = 0;
unsigned int rebuilds_per_group = 0, copies, raid_disks;
unsigned int group_size, last_group_start;
for (i = 0; i < rs->raid_disks; i++)
if (!test_bit(FirstUse, &rs->dev[i].rdev.flags) &&
((!test_bit(In_sync, &rs->dev[i].rdev.flags) ||
!rs->dev[i].rdev.sb_page)))
rebuild_cnt++;
switch (rs->md.level) {
case 0:
break;
case 1:
if (rebuild_cnt >= rs->md.raid_disks)
goto too_many;
break;
case 4:
case 5:
case 6:
if (rebuild_cnt > rs->raid_type->parity_devs)
goto too_many;
break;
case 10:
copies = raid10_md_layout_to_copies(rs->md.new_layout);
if (copies < 2) {
DMERR("Bogus raid10 data copies < 2!");
return -EINVAL;
}
if (rebuild_cnt < copies)
break;
/*
* It is possible to have a higher rebuild count for RAID10,
* as long as the failed devices occur in different mirror
* groups (i.e. different stripes).
*
* When checking "near" format, make sure no adjacent devices
* have failed beyond what can be handled. In addition to the
* simple case where the number of devices is a multiple of the
* number of copies, we must also handle cases where the number
* of devices is not a multiple of the number of copies.
* E.g. dev1 dev2 dev3 dev4 dev5
* A A B B C
* C D D E E
*/
raid_disks = min(rs->raid_disks, rs->md.raid_disks);
if (__is_raid10_near(rs->md.new_layout)) {
for (i = 0; i < raid_disks; i++) {
if (!(i % copies))
rebuilds_per_group = 0;
if ((!rs->dev[i].rdev.sb_page ||
!test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
(++rebuilds_per_group >= copies))
goto too_many;
}
break;
}
/*
* When checking "far" and "offset" formats, we need to ensure
* that the device that holds its copy is not also dead or
* being rebuilt. (Note that "far" and "offset" formats only
* support two copies right now. These formats also only ever
* use the 'use_far_sets' variant.)
*
* This check is somewhat complicated by the need to account
* for arrays that are not a multiple of (far) copies. This
* results in the need to treat the last (potentially larger)
* set differently.
*/
group_size = (raid_disks / copies);
last_group_start = (raid_disks / group_size) - 1;
last_group_start *= group_size;
for (i = 0; i < raid_disks; i++) {
if (!(i % copies) && !(i > last_group_start))
rebuilds_per_group = 0;
if ((!rs->dev[i].rdev.sb_page ||
!test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
(++rebuilds_per_group >= copies))
goto too_many;
}
break;
default:
if (rebuild_cnt)
return -EINVAL;
}
return 0;
too_many:
return -EINVAL;
}
/*
* Possible arguments are...
* <chunk_size> [optional_args]
*
* Argument definitions
* <chunk_size> The number of sectors per disk that
* will form the "stripe"
* [[no]sync] Force or prevent recovery of the
* entire array
* [rebuild <idx>] Rebuild the drive indicated by the index
* [daemon_sleep <ms>] Time between bitmap daemon work to
* clear bits
* [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
* [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
* [write_mostly <idx>] Indicate a write mostly drive via index
* [max_write_behind <sectors>] See '-write-behind=' (man mdadm)
* [stripe_cache <sectors>] Stripe cache size for higher RAIDs
* [region_size <sectors>] Defines granularity of bitmap
* [journal_dev <dev>] raid4/5/6 journaling deviice
* (i.e. write hole closing log)
*
* RAID10-only options:
* [raid10_copies <# copies>] Number of copies. (Default: 2)
* [raid10_format <near|far|offset>] Layout algorithm. (Default: near)
*/
static int parse_raid_params(struct raid_set *rs, struct dm_arg_set *as,
unsigned int num_raid_params)
{
int value, raid10_format = ALGORITHM_RAID10_DEFAULT;
unsigned int raid10_copies = 2;
unsigned int i, write_mostly = 0;
unsigned int region_size = 0;
sector_t max_io_len;
const char *arg, *key;
struct raid_dev *rd;
struct raid_type *rt = rs->raid_type;
arg = dm_shift_arg(as);
num_raid_params--; /* Account for chunk_size argument */
if (kstrtoint(arg, 10, &value) < 0) {
rs->ti->error = "Bad numerical argument given for chunk_size";
return -EINVAL;
}
/*
* First, parse the in-order required arguments
* "chunk_size" is the only argument of this type.
*/
if (rt_is_raid1(rt)) {
if (value)
DMERR("Ignoring chunk size parameter for RAID 1");
value = 0;
} else if (!is_power_of_2(value)) {
rs->ti->error = "Chunk size must be a power of 2";
return -EINVAL;
} else if (value < 8) {
rs->ti->error = "Chunk size value is too small";
return -EINVAL;
}
rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
/*
* We set each individual device as In_sync with a completed
* 'recovery_offset'. If there has been a device failure or
* replacement then one of the following cases applies:
*
* 1) User specifies 'rebuild'.
* - Device is reset when param is read.
* 2) A new device is supplied.
* - No matching superblock found, resets device.
* 3) Device failure was transient and returns on reload.
* - Failure noticed, resets device for bitmap replay.
* 4) Device hadn't completed recovery after previous failure.
* - Superblock is read and overrides recovery_offset.
*
* What is found in the superblocks of the devices is always
* authoritative, unless 'rebuild' or '[no]sync' was specified.
*/
for (i = 0; i < rs->raid_disks; i++) {
set_bit(In_sync, &rs->dev[i].rdev.flags);
rs->dev[i].rdev.recovery_offset = MaxSector;
}
/*
* Second, parse the unordered optional arguments
*/
for (i = 0; i < num_raid_params; i++) {
key = dm_shift_arg(as);
if (!key) {
rs->ti->error = "Not enough raid parameters given";
return -EINVAL;
}
if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC))) {
if (test_and_set_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
rs->ti->error = "Only one 'nosync' argument allowed";
return -EINVAL;
}
continue;
}
if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_SYNC))) {
if (test_and_set_bit(__CTR_FLAG_SYNC, &rs->ctr_flags)) {
rs->ti->error = "Only one 'sync' argument allowed";
return -EINVAL;
}
continue;
}
if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_USE_NEAR_SETS))) {
if (test_and_set_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags)) {
rs->ti->error = "Only one 'raid10_use_new_sets' argument allowed";
return -EINVAL;
}
continue;
}
arg = dm_shift_arg(as);
i++; /* Account for the argument pairs */
if (!arg) {
rs->ti->error = "Wrong number of raid parameters given";
return -EINVAL;
}
/*
* Parameters that take a string value are checked here.
*/
/* "raid10_format {near|offset|far} */
if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT))) {
if (test_and_set_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags)) {
rs->ti->error = "Only one 'raid10_format' argument pair allowed";
return -EINVAL;
}
if (!rt_is_raid10(rt)) {
rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
return -EINVAL;
}
raid10_format = raid10_name_to_format(arg);
if (raid10_format < 0) {
rs->ti->error = "Invalid 'raid10_format' value given";
return raid10_format;
}
continue;
}
/* "journal_dev <dev>" */
if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_DEV))) {
int r;
struct md_rdev *jdev;
if (test_and_set_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
rs->ti->error = "Only one raid4/5/6 set journaling device allowed";
return -EINVAL;
}
if (!rt_is_raid456(rt)) {
rs->ti->error = "'journal_dev' is an invalid parameter for this RAID type";
return -EINVAL;
}
r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
&rs->journal_dev.dev);
if (r) {
rs->ti->error = "raid4/5/6 journal device lookup failure";
return r;
}
jdev = &rs->journal_dev.rdev;
md_rdev_init(jdev);
jdev->mddev = &rs->md;
jdev->bdev = rs->journal_dev.dev->bdev;
jdev->sectors = bdev_nr_sectors(jdev->bdev);
if (jdev->sectors < MIN_RAID456_JOURNAL_SPACE) {
rs->ti->error = "No space for raid4/5/6 journal";
return -ENOSPC;
}
rs->journal_dev.mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
set_bit(Journal, &jdev->flags);
continue;
}
/* "journal_mode <mode>" ("journal_dev" mandatory!) */
if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_MODE))) {
int r;
if (!test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
rs->ti->error = "raid4/5/6 'journal_mode' is invalid without 'journal_dev'";
return -EINVAL;
}
if (test_and_set_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags)) {
rs->ti->error = "Only one raid4/5/6 'journal_mode' argument allowed";
return -EINVAL;
}
r = dm_raid_journal_mode_to_md(arg);
if (r < 0) {
rs->ti->error = "Invalid 'journal_mode' argument";
return r;
}
rs->journal_dev.mode = r;
continue;
}
/*
* Parameters with number values from here on.
*/
if (kstrtoint(arg, 10, &value) < 0) {
rs->ti->error = "Bad numerical argument given in raid params";
return -EINVAL;
}
if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD))) {
/*
* "rebuild" is being passed in by userspace to provide
* indexes of replaced devices and to set up additional
* devices on raid level takeover.
*/
if (!__within_range(value, 0, rs->raid_disks - 1)) {
rs->ti->error = "Invalid rebuild index given";
return -EINVAL;
}
if (test_and_set_bit(value, (void *) rs->rebuild_disks)) {
rs->ti->error = "rebuild for this index already given";
return -EINVAL;
}
rd = rs->dev + value;
clear_bit(In_sync, &rd->rdev.flags);
clear_bit(Faulty, &rd->rdev.flags);
rd->rdev.recovery_offset = 0;
set_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags);
} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY))) {
if (!rt_is_raid1(rt)) {
rs->ti->error = "write_mostly option is only valid for RAID1";
return -EINVAL;
}
if (!__within_range(value, 0, rs->md.raid_disks - 1)) {
rs->ti->error = "Invalid write_mostly index given";
return -EINVAL;
}
write_mostly++;
set_bit(WriteMostly, &rs->dev[value].rdev.flags);
set_bit(__CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags);
} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND))) {
if (!rt_is_raid1(rt)) {
rs->ti->error = "max_write_behind option is only valid for RAID1";
return -EINVAL;
}
if (test_and_set_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags)) {
rs->ti->error = "Only one max_write_behind argument pair allowed";
return -EINVAL;
}
/*
* In device-mapper, we specify things in sectors, but
* MD records this value in kB
*/
if (value < 0 || value / 2 > COUNTER_MAX) {
rs->ti->error = "Max write-behind limit out of range";
return -EINVAL;
}
rs->md.bitmap_info.max_write_behind = value / 2;
} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP))) {
if (test_and_set_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags)) {
rs->ti->error = "Only one daemon_sleep argument pair allowed";
return -EINVAL;
}
if (value < 0) {
rs->ti->error = "daemon sleep period out of range";
return -EINVAL;
}
rs->md.bitmap_info.daemon_sleep = value;
} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET))) {
/* Userspace passes new data_offset after having extended the data image LV */
if (test_and_set_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags)) {
rs->ti->error = "Only one data_offset argument pair allowed";
return -EINVAL;
}
/* Ensure sensible data offset */
if (value < 0 ||
(value && (value < MIN_FREE_RESHAPE_SPACE || value % to_sector(PAGE_SIZE)))) {
rs->ti->error = "Bogus data_offset value";
return -EINVAL;
}
rs->data_offset = value;
} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS))) {
/* Define the +/-# of disks to add to/remove from the given raid set */
if (test_and_set_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
rs->ti->error = "Only one delta_disks argument pair allowed";
return -EINVAL;
}
/* Ensure MAX_RAID_DEVICES and raid type minimal_devs! */
if (!__within_range(abs(value), 1, MAX_RAID_DEVICES - rt->minimal_devs)) {
rs->ti->error = "Too many delta_disk requested";
return -EINVAL;
}
rs->delta_disks = value;
} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE))) {
if (test_and_set_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags)) {
rs->ti->error = "Only one stripe_cache argument pair allowed";
return -EINVAL;
}
if (!rt_is_raid456(rt)) {
rs->ti->error = "Inappropriate argument: stripe_cache";
return -EINVAL;
}
if (value < 0) {
rs->ti->error = "Bogus stripe cache entries value";
return -EINVAL;
}
rs->stripe_cache_entries = value;
} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE))) {
if (test_and_set_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags)) {
rs->ti->error = "Only one min_recovery_rate argument pair allowed";
return -EINVAL;
}
if (value < 0) {
rs->ti->error = "min_recovery_rate out of range";
return -EINVAL;
}
rs->md.sync_speed_min = value;
} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE))) {
if (test_and_set_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags)) {
rs->ti->error = "Only one max_recovery_rate argument pair allowed";
return -EINVAL;
}
if (value < 0) {
rs->ti->error = "max_recovery_rate out of range";
return -EINVAL;
}
rs->md.sync_speed_max = value;
} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE))) {
if (test_and_set_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags)) {
rs->ti->error = "Only one region_size argument pair allowed";
return -EINVAL;
}
region_size = value;
rs->requested_bitmap_chunk_sectors = value;
} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES))) {
if (test_and_set_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags)) {
rs->ti->error = "Only one raid10_copies argument pair allowed";
return -EINVAL;
}
if (!__within_range(value, 2, rs->md.raid_disks)) {
rs->ti->error = "Bad value for 'raid10_copies'";
return -EINVAL;
}
raid10_copies = value;
} else {
DMERR("Unable to parse RAID parameter: %s", key);
rs->ti->error = "Unable to parse RAID parameter";
return -EINVAL;
}
}
if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) &&
test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
rs->ti->error = "sync and nosync are mutually exclusive";
return -EINVAL;
}
if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) &&
(test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) ||
test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))) {
rs->ti->error = "sync/nosync and rebuild are mutually exclusive";
return -EINVAL;
}
if (write_mostly >= rs->md.raid_disks) {
rs->ti->error = "Can't set all raid1 devices to write_mostly";
return -EINVAL;
}
if (rs->md.sync_speed_max &&
rs->md.sync_speed_min > rs->md.sync_speed_max) {
rs->ti->error = "Bogus recovery rates";
return -EINVAL;
}
if (validate_region_size(rs, region_size))
return -EINVAL;
if (rs->md.chunk_sectors)
max_io_len = rs->md.chunk_sectors;
else
max_io_len = region_size;
if (dm_set_target_max_io_len(rs->ti, max_io_len))
return -EINVAL;
if (rt_is_raid10(rt)) {
if (raid10_copies > rs->md.raid_disks) {
rs->ti->error = "Not enough devices to satisfy specification";
return -EINVAL;
}
rs->md.new_layout = raid10_format_to_md_layout(rs, raid10_format, raid10_copies);
if (rs->md.new_layout < 0) {
rs->ti->error = "Error getting raid10 format";
return rs->md.new_layout;
}
rt = get_raid_type_by_ll(10, rs->md.new_layout);
if (!rt) {
rs->ti->error = "Failed to recognize new raid10 layout";
return -EINVAL;
}
if ((rt->algorithm == ALGORITHM_RAID10_DEFAULT ||
rt->algorithm == ALGORITHM_RAID10_NEAR) &&
test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags)) {
rs->ti->error = "RAID10 format 'near' and 'raid10_use_near_sets' are incompatible";
return -EINVAL;
}
}
rs->raid10_copies = raid10_copies;
/* Assume there are no metadata devices until the drives are parsed */
rs->md.persistent = 0;
rs->md.external = 1;
/* Check, if any invalid ctr arguments have been passed in for the raid level */
return rs_check_for_valid_flags(rs);
}
/* Set raid4/5/6 cache size */
static int rs_set_raid456_stripe_cache(struct raid_set *rs)
{
int r;
struct r5conf *conf;
struct mddev *mddev = &rs->md;
uint32_t min_stripes = max(mddev->chunk_sectors, mddev->new_chunk_sectors) / 2;
uint32_t nr_stripes = rs->stripe_cache_entries;
if (!rt_is_raid456(rs->raid_type)) {
rs->ti->error = "Inappropriate raid level; cannot change stripe_cache size";
return -EINVAL;
}
if (nr_stripes < min_stripes) {
DMINFO("Adjusting requested %u stripe cache entries to %u to suit stripe size",
nr_stripes, min_stripes);
nr_stripes = min_stripes;
}
conf = mddev->private;
if (!conf) {
rs->ti->error = "Cannot change stripe_cache size on inactive RAID set";
return -EINVAL;
}
/* Try setting number of stripes in raid456 stripe cache */
if (conf->min_nr_stripes != nr_stripes) {
r = raid5_set_cache_size(mddev, nr_stripes);
if (r) {
rs->ti->error = "Failed to set raid4/5/6 stripe cache size";
return r;
}
DMINFO("%u stripe cache entries", nr_stripes);
}
return 0;
}
/* Return # of data stripes as kept in mddev as of @rs (i.e. as of superblock) */
static unsigned int mddev_data_stripes(struct raid_set *rs)
{
return rs->md.raid_disks - rs->raid_type->parity_devs;
}
/* Return # of data stripes of @rs (i.e. as of ctr) */
static unsigned int rs_data_stripes(struct raid_set *rs)
{
return rs->raid_disks - rs->raid_type->parity_devs;
}
/*
* Retrieve rdev->sectors from any valid raid device of @rs
* to allow userpace to pass in arbitray "- -" device tupples.
*/
static sector_t __rdev_sectors(struct raid_set *rs)
{
int i;
for (i = 0; i < rs->raid_disks; i++) {
struct md_rdev *rdev = &rs->dev[i].rdev;
if (!test_bit(Journal, &rdev->flags) &&
rdev->bdev && rdev->sectors)
return rdev->sectors;
}
return 0;
}
/* Check that calculated dev_sectors fits all component devices. */
static int _check_data_dev_sectors(struct raid_set *rs)
{
sector_t ds = ~0;
struct md_rdev *rdev;
rdev_for_each(rdev, &rs->md)
if (!test_bit(Journal, &rdev->flags) && rdev->bdev) {
ds = min(ds, bdev_nr_sectors(rdev->bdev));
if (ds < rs->md.dev_sectors) {
rs->ti->error = "Component device(s) too small";
return -EINVAL;
}
}
return 0;
}
/* Calculate the sectors per device and per array used for @rs */
static int rs_set_dev_and_array_sectors(struct raid_set *rs, sector_t sectors, bool use_mddev)
{
int delta_disks;
unsigned int data_stripes;
sector_t array_sectors = sectors, dev_sectors = sectors;
struct mddev *mddev = &rs->md;
if (use_mddev) {
delta_disks = mddev->delta_disks;
data_stripes = mddev_data_stripes(rs);
} else {
delta_disks = rs->delta_disks;
data_stripes = rs_data_stripes(rs);
}
/* Special raid1 case w/o delta_disks support (yet) */
if (rt_is_raid1(rs->raid_type))
;
else if (rt_is_raid10(rs->raid_type)) {
if (rs->raid10_copies < 2 ||
delta_disks < 0) {
rs->ti->error = "Bogus raid10 data copies or delta disks";
return -EINVAL;
}
dev_sectors *= rs->raid10_copies;
if (sector_div(dev_sectors, data_stripes))
goto bad;
array_sectors = (data_stripes + delta_disks) * dev_sectors;
if (sector_div(array_sectors, rs->raid10_copies))
goto bad;
} else if (sector_div(dev_sectors, data_stripes))
goto bad;
else
/* Striped layouts */
array_sectors = (data_stripes + delta_disks) * dev_sectors;
mddev->array_sectors = array_sectors;
mddev->dev_sectors = dev_sectors;
rs_set_rdev_sectors(rs);
return _check_data_dev_sectors(rs);
bad:
rs->ti->error = "Target length not divisible by number of data devices";
return -EINVAL;
}
/* Setup recovery on @rs */
static void rs_setup_recovery(struct raid_set *rs, sector_t dev_sectors)
{
/* raid0 does not recover */
if (rs_is_raid0(rs))
rs->md.recovery_cp = MaxSector;
/*
* A raid6 set has to be recovered either
* completely or for the grown part to
* ensure proper parity and Q-Syndrome
*/
else if (rs_is_raid6(rs))
rs->md.recovery_cp = dev_sectors;
/*
* Other raid set types may skip recovery
* depending on the 'nosync' flag.
*/
else
rs->md.recovery_cp = test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)
? MaxSector : dev_sectors;
}
static void do_table_event(struct work_struct *ws)
{
struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
smp_rmb(); /* Make sure we access most actual mddev properties */
if (!rs_is_reshaping(rs)) {
if (rs_is_raid10(rs))
rs_set_rdev_sectors(rs);
rs_set_capacity(rs);
}
dm_table_event(rs->ti->table);
}
/*
* Make sure a valid takover (level switch) is being requested on @rs
*
* Conversions of raid sets from one MD personality to another
* have to conform to restrictions which are enforced here.
*/
static int rs_check_takeover(struct raid_set *rs)
{
struct mddev *mddev = &rs->md;
unsigned int near_copies;
if (rs->md.degraded) {
rs->ti->error = "Can't takeover degraded raid set";
return -EPERM;
}
if (rs_is_reshaping(rs)) {
rs->ti->error = "Can't takeover reshaping raid set";
return -EPERM;
}
switch (mddev->level) {
case 0:
/* raid0 -> raid1/5 with one disk */
if ((mddev->new_level == 1 || mddev->new_level == 5) &&
mddev->raid_disks == 1)
return 0;
/* raid0 -> raid10 */
if (mddev->new_level == 10 &&
!(rs->raid_disks % mddev->raid_disks))
return 0;
/* raid0 with multiple disks -> raid4/5/6 */
if (__within_range(mddev->new_level, 4, 6) &&
mddev->new_layout == ALGORITHM_PARITY_N &&
mddev->raid_disks > 1)
return 0;
break;
case 10:
/* Can't takeover raid10_offset! */
if (__is_raid10_offset(mddev->layout))
break;
near_copies = __raid10_near_copies(mddev->layout);
/* raid10* -> raid0 */
if (mddev->new_level == 0) {
/* Can takeover raid10_near with raid disks divisable by data copies! */
if (near_copies > 1 &&
!(mddev->raid_disks % near_copies)) {
mddev->raid_disks /= near_copies;
mddev->delta_disks = mddev->raid_disks;
return 0;
}
/* Can takeover raid10_far */
if (near_copies == 1 &&
__raid10_far_copies(mddev->layout) > 1)
return 0;
break;
}
/* raid10_{near,far} -> raid1 */
if (mddev->new_level == 1 &&
max(near_copies, __raid10_far_copies(mddev->layout)) == mddev->raid_disks)
return 0;
/* raid10_{near,far} with 2 disks -> raid4/5 */
if (__within_range(mddev->new_level, 4, 5) &&
mddev->raid_disks == 2)
return 0;
break;
case 1:
/* raid1 with 2 disks -> raid4/5 */
if (__within_range(mddev->new_level, 4, 5) &&
mddev->raid_disks == 2) {
mddev->degraded = 1;
return 0;
}
/* raid1 -> raid0 */
if (mddev->new_level == 0 &&
mddev->raid_disks == 1)
return 0;
/* raid1 -> raid10 */
if (mddev->new_level == 10)
return 0;
break;
case 4:
/* raid4 -> raid0 */
if (mddev->new_level == 0)
return 0;
/* raid4 -> raid1/5 with 2 disks */
if ((mddev->new_level == 1 || mddev->new_level == 5) &&
mddev->raid_disks == 2)
return 0;
/* raid4 -> raid5/6 with parity N */
if (__within_range(mddev->new_level, 5, 6) &&
mddev->layout == ALGORITHM_PARITY_N)
return 0;
break;
case 5:
/* raid5 with parity N -> raid0 */
if (mddev->new_level == 0 &&
mddev->layout == ALGORITHM_PARITY_N)
return 0;
/* raid5 with parity N -> raid4 */
if (mddev->new_level == 4 &&
mddev->layout == ALGORITHM_PARITY_N)
return 0;
/* raid5 with 2 disks -> raid1/4/10 */
if ((mddev->new_level == 1 || mddev->new_level == 4 || mddev->new_level == 10) &&
mddev->raid_disks == 2)
return 0;
/* raid5_* -> raid6_*_6 with Q-Syndrome N (e.g. raid5_ra -> raid6_ra_6 */
if (mddev->new_level == 6 &&
((mddev->layout == ALGORITHM_PARITY_N && mddev->new_layout == ALGORITHM_PARITY_N) ||
__within_range(mddev->new_layout, ALGORITHM_LEFT_ASYMMETRIC_6, ALGORITHM_RIGHT_SYMMETRIC_6)))
return 0;
break;
case 6:
/* raid6 with parity N -> raid0 */
if (mddev->new_level == 0 &&
mddev->layout == ALGORITHM_PARITY_N)
return 0;
/* raid6 with parity N -> raid4 */
if (mddev->new_level == 4 &&
mddev->layout == ALGORITHM_PARITY_N)
return 0;
/* raid6_*_n with Q-Syndrome N -> raid5_* */
if (mddev->new_level == 5 &&
((mddev->layout == ALGORITHM_PARITY_N && mddev->new_layout == ALGORITHM_PARITY_N) ||
__within_range(mddev->new_layout, ALGORITHM_LEFT_ASYMMETRIC, ALGORITHM_RIGHT_SYMMETRIC)))
return 0;
break;
default:
break;
}
rs->ti->error = "takeover not possible";
return -EINVAL;
}
/* True if @rs requested to be taken over */
static bool rs_takeover_requested(struct raid_set *rs)
{
return rs->md.new_level != rs->md.level;
}
/* True if layout is set to reshape. */
static bool rs_is_layout_change(struct raid_set *rs, bool use_mddev)
{
return (use_mddev ? rs->md.delta_disks : rs->delta_disks) ||
rs->md.new_layout != rs->md.layout ||
rs->md.new_chunk_sectors != rs->md.chunk_sectors;
}
/* True if @rs is requested to reshape by ctr */
static bool rs_reshape_requested(struct raid_set *rs)
{
bool change;
struct mddev *mddev = &rs->md;
if (rs_takeover_requested(rs))
return false;
if (rs_is_raid0(rs))
return false;
change = rs_is_layout_change(rs, false);
/* Historical case to support raid1 reshape without delta disks */
if (rs_is_raid1(rs)) {
if (rs->delta_disks)
return !!rs->delta_disks;
return !change &&
mddev->raid_disks != rs->raid_disks;
}
if (rs_is_raid10(rs))
return change &&
!__is_raid10_far(mddev->new_layout) &&
rs->delta_disks >= 0;
return change;
}
/* Features */
#define FEATURE_FLAG_SUPPORTS_V190 0x1 /* Supports extended superblock */
/* State flags for sb->flags */
#define SB_FLAG_RESHAPE_ACTIVE 0x1
#define SB_FLAG_RESHAPE_BACKWARDS 0x2
/*
* This structure is never routinely used by userspace, unlike md superblocks.
* Devices with this superblock should only ever be accessed via device-mapper.
*/
#define DM_RAID_MAGIC 0x64526D44
struct dm_raid_superblock {
__le32 magic; /* "DmRd" */
__le32 compat_features; /* Used to indicate compatible features (like 1.9.0 ondisk metadata extension) */
__le32 num_devices; /* Number of devices in this raid set. (Max 64) */
__le32 array_position; /* The position of this drive in the raid set */
__le64 events; /* Incremented by md when superblock updated */
__le64 failed_devices; /* Pre 1.9.0 part of bit field of devices to */
/* indicate failures (see extension below) */
/*
* This offset tracks the progress of the repair or replacement of
* an individual drive.
*/
__le64 disk_recovery_offset;
/*
* This offset tracks the progress of the initial raid set
* synchronisation/parity calculation.
*/
__le64 array_resync_offset;
/*
* raid characteristics
*/
__le32 level;
__le32 layout;
__le32 stripe_sectors;
/********************************************************************
* BELOW FOLLOW V1.9.0 EXTENSIONS TO THE PRISTINE SUPERBLOCK FORMAT!!!
*
* FEATURE_FLAG_SUPPORTS_V190 in the compat_features member indicates that those exist
*/
__le32 flags; /* Flags defining array states for reshaping */
/*
* This offset tracks the progress of a raid
* set reshape in order to be able to restart it
*/
__le64 reshape_position;
/*
* These define the properties of the array in case of an interrupted reshape
*/
__le32 new_level;
__le32 new_layout;
__le32 new_stripe_sectors;
__le32 delta_disks;
__le64 array_sectors; /* Array size in sectors */
/*
* Sector offsets to data on devices (reshaping).
* Needed to support out of place reshaping, thus
* not writing over any stripes whilst converting
* them from old to new layout
*/
__le64 data_offset;
__le64 new_data_offset;
__le64 sectors; /* Used device size in sectors */
/*
* Additional Bit field of devices indicating failures to support
* up to 256 devices with the 1.9.0 on-disk metadata format
*/
__le64 extended_failed_devices[DISKS_ARRAY_ELEMS - 1];
__le32 incompat_features; /* Used to indicate any incompatible features */
/* Always set rest up to logical block size to 0 when writing (see get_metadata_device() below). */
} __packed;
/*
* Check for reshape constraints on raid set @rs:
*
* - reshape function non-existent
* - degraded set
* - ongoing recovery
* - ongoing reshape
*
* Returns 0 if none or -EPERM if given constraint
* and error message reference in @errmsg
*/
static int rs_check_reshape(struct raid_set *rs)
{
struct mddev *mddev = &rs->md;
if (!mddev->pers || !mddev->pers->check_reshape)
rs->ti->error = "Reshape not supported";
else if (mddev->degraded)
rs->ti->error = "Can't reshape degraded raid set";
else if (rs_is_recovering(rs))
rs->ti->error = "Convert request on recovering raid set prohibited";
else if (rs_is_reshaping(rs))
rs->ti->error = "raid set already reshaping!";
else if (!(rs_is_raid1(rs) || rs_is_raid10(rs) || rs_is_raid456(rs)))
rs->ti->error = "Reshaping only supported for raid1/4/5/6/10";
else
return 0;
return -EPERM;
}
static int read_disk_sb(struct md_rdev *rdev, int size, bool force_reload)
{
BUG_ON(!rdev->sb_page);
if (rdev->sb_loaded && !force_reload)
return 0;
rdev->sb_loaded = 0;
if (!sync_page_io(rdev, 0, size, rdev->sb_page, REQ_OP_READ, true)) {
DMERR("Failed to read superblock of device at position %d",
rdev->raid_disk);
md_error(rdev->mddev, rdev);
set_bit(Faulty, &rdev->flags);
return -EIO;
}
rdev->sb_loaded = 1;
return 0;
}
static void sb_retrieve_failed_devices(struct dm_raid_superblock *sb, uint64_t *failed_devices)
{
failed_devices[0] = le64_to_cpu(sb->failed_devices);
memset(failed_devices + 1, 0, sizeof(sb->extended_failed_devices));
if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190) {
int i = ARRAY_SIZE(sb->extended_failed_devices);
while (i--)
failed_devices[i+1] = le64_to_cpu(sb->extended_failed_devices[i]);
}
}
static void sb_update_failed_devices(struct dm_raid_superblock *sb, uint64_t *failed_devices)
{
int i = ARRAY_SIZE(sb->extended_failed_devices);
sb->failed_devices = cpu_to_le64(failed_devices[0]);
while (i--)
sb->extended_failed_devices[i] = cpu_to_le64(failed_devices[i+1]);
}
/*
* Synchronize the superblock members with the raid set properties
*
* All superblock data is little endian.
*/
static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
{
bool update_failed_devices = false;
unsigned int i;
uint64_t failed_devices[DISKS_ARRAY_ELEMS];
struct dm_raid_superblock *sb;
struct raid_set *rs = container_of(mddev, struct raid_set, md);
/* No metadata device, no superblock */
if (!rdev->meta_bdev)
return;
BUG_ON(!rdev->sb_page);
sb = page_address(rdev->sb_page);
sb_retrieve_failed_devices(sb, failed_devices);
for (i = 0; i < rs->raid_disks; i++)
if (!rs->dev[i].data_dev || test_bit(Faulty, &rs->dev[i].rdev.flags)) {
update_failed_devices = true;
set_bit(i, (void *) failed_devices);
}
if (update_failed_devices)
sb_update_failed_devices(sb, failed_devices);
sb->magic = cpu_to_le32(DM_RAID_MAGIC);
sb->compat_features = cpu_to_le32(FEATURE_FLAG_SUPPORTS_V190);
sb->num_devices = cpu_to_le32(mddev->raid_disks);
sb->array_position = cpu_to_le32(rdev->raid_disk);
sb->events = cpu_to_le64(mddev->events);
sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
sb->level = cpu_to_le32(mddev->level);
sb->layout = cpu_to_le32(mddev->layout);
sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
/********************************************************************
* BELOW FOLLOW V1.9.0 EXTENSIONS TO THE PRISTINE SUPERBLOCK FORMAT!!!
*
* FEATURE_FLAG_SUPPORTS_V190 in the compat_features member indicates that those exist
*/
sb->new_level = cpu_to_le32(mddev->new_level);
sb->new_layout = cpu_to_le32(mddev->new_layout);
sb->new_stripe_sectors = cpu_to_le32(mddev->new_chunk_sectors);
sb->delta_disks = cpu_to_le32(mddev->delta_disks);
smp_rmb(); /* Make sure we access most recent reshape position */
sb->reshape_position = cpu_to_le64(mddev->reshape_position);
if (le64_to_cpu(sb->reshape_position) != MaxSector) {
/* Flag ongoing reshape */
sb->flags |= cpu_to_le32(SB_FLAG_RESHAPE_ACTIVE);
if (mddev->delta_disks < 0 || mddev->reshape_backwards)
sb->flags |= cpu_to_le32(SB_FLAG_RESHAPE_BACKWARDS);
} else {
/* Clear reshape flags */
sb->flags &= ~(cpu_to_le32(SB_FLAG_RESHAPE_ACTIVE|SB_FLAG_RESHAPE_BACKWARDS));
}
sb->array_sectors = cpu_to_le64(mddev->array_sectors);
sb->data_offset = cpu_to_le64(rdev->data_offset);
sb->new_data_offset = cpu_to_le64(rdev->new_data_offset);
sb->sectors = cpu_to_le64(rdev->sectors);
sb->incompat_features = cpu_to_le32(0);
/* Zero out the rest of the payload after the size of the superblock */
memset(sb + 1, 0, rdev->sb_size - sizeof(*sb));
}
/*
* super_load
*
* This function creates a superblock if one is not found on the device
* and will decide which superblock to use if there's a choice.
*
* Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
*/
static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
{
int r;
struct dm_raid_superblock *sb;
struct dm_raid_superblock *refsb;
uint64_t events_sb, events_refsb;
r = read_disk_sb(rdev, rdev->sb_size, false);
if (r)
return r;
sb = page_address(rdev->sb_page);
/*
* Two cases that we want to write new superblocks and rebuild:
* 1) New device (no matching magic number)
* 2) Device specified for rebuild (!In_sync w/ offset == 0)
*/
if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
(!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
super_sync(rdev->mddev, rdev);
set_bit(FirstUse, &rdev->flags);
sb->compat_features = cpu_to_le32(FEATURE_FLAG_SUPPORTS_V190);
/* Force writing of superblocks to disk */
set_bit(MD_SB_CHANGE_DEVS, &rdev->mddev->sb_flags);
/* Any superblock is better than none, choose that if given */
return refdev ? 0 : 1;
}
if (!refdev)
return 1;
events_sb = le64_to_cpu(sb->events);
refsb = page_address(refdev->sb_page);
events_refsb = le64_to_cpu(refsb->events);
return (events_sb > events_refsb) ? 1 : 0;
}
static int super_init_validation(struct raid_set *rs, struct md_rdev *rdev)
{
int role;
struct mddev *mddev = &rs->md;
uint64_t events_sb;
uint64_t failed_devices[DISKS_ARRAY_ELEMS];
struct dm_raid_superblock *sb;
uint32_t new_devs = 0, rebuild_and_new = 0, rebuilds = 0;
struct md_rdev *r;
struct dm_raid_superblock *sb2;
sb = page_address(rdev->sb_page);
events_sb = le64_to_cpu(sb->events);
/*
* Initialise to 1 if this is a new superblock.
*/
mddev->events = events_sb ? : 1;
mddev->reshape_position = MaxSector;
mddev->raid_disks = le32_to_cpu(sb->num_devices);
mddev->level = le32_to_cpu(sb->level);
mddev->layout = le32_to_cpu(sb->layout);
mddev->chunk_sectors = le32_to_cpu(sb->stripe_sectors);
/*
* Reshaping is supported, e.g. reshape_position is valid
* in superblock and superblock content is authoritative.
*/
if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190) {
/* Superblock is authoritative wrt given raid set layout! */
mddev->new_level = le32_to_cpu(sb->new_level);
mddev->new_layout = le32_to_cpu(sb->new_layout);
mddev->new_chunk_sectors = le32_to_cpu(sb->new_stripe_sectors);
mddev->delta_disks = le32_to_cpu(sb->delta_disks);
mddev->array_sectors = le64_to_cpu(sb->array_sectors);
/* raid was reshaping and got interrupted */
if (le32_to_cpu(sb->flags) & SB_FLAG_RESHAPE_ACTIVE) {
if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
DMERR("Reshape requested but raid set is still reshaping");
return -EINVAL;
}
if (mddev->delta_disks < 0 ||
(!mddev->delta_disks && (le32_to_cpu(sb->flags) & SB_FLAG_RESHAPE_BACKWARDS)))
mddev->reshape_backwards = 1;
else
mddev->reshape_backwards = 0;
mddev->reshape_position = le64_to_cpu(sb->reshape_position);
rs->raid_type = get_raid_type_by_ll(mddev->level, mddev->layout);
}
} else {
/*
* No takeover/reshaping, because we don't have the extended v1.9.0 metadata
*/
struct raid_type *rt_cur = get_raid_type_by_ll(mddev->level, mddev->layout);
struct raid_type *rt_new = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
if (rs_takeover_requested(rs)) {
if (rt_cur && rt_new)
DMERR("Takeover raid sets from %s to %s not yet supported by metadata. (raid level change)",
rt_cur->name, rt_new->name);
else
DMERR("Takeover raid sets not yet supported by metadata. (raid level change)");
return -EINVAL;
} else if (rs_reshape_requested(rs)) {
DMERR("Reshaping raid sets not yet supported by metadata. (raid layout change keeping level)");
if (mddev->layout != mddev->new_layout) {
if (rt_cur && rt_new)
DMERR(" current layout %s vs new layout %s",
rt_cur->name, rt_new->name);
else
DMERR(" current layout 0x%X vs new layout 0x%X",
le32_to_cpu(sb->layout), mddev->new_layout);
}
if (mddev->chunk_sectors != mddev->new_chunk_sectors)
DMERR(" current stripe sectors %u vs new stripe sectors %u",
mddev->chunk_sectors, mddev->new_chunk_sectors);
if (rs->delta_disks)
DMERR(" current %u disks vs new %u disks",
mddev->raid_disks, mddev->raid_disks + rs->delta_disks);
if (rs_is_raid10(rs)) {
DMERR(" Old layout: %s w/ %u copies",
raid10_md_layout_to_format(mddev->layout),
raid10_md_layout_to_copies(mddev->layout));
DMERR(" New layout: %s w/ %u copies",
raid10_md_layout_to_format(mddev->new_layout),
raid10_md_layout_to_copies(mddev->new_layout));
}
return -EINVAL;
}
DMINFO("Discovered old metadata format; upgrading to extended metadata format");
}
if (!test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
/*
* During load, we set FirstUse if a new superblock was written.
* There are two reasons we might not have a superblock:
* 1) The raid set is brand new - in which case, all of the
* devices must have their In_sync bit set. Also,
* recovery_cp must be 0, unless forced.
* 2) This is a new device being added to an old raid set
* and the new device needs to be rebuilt - in which
* case the In_sync bit will /not/ be set and
* recovery_cp must be MaxSector.
* 3) This is/are a new device(s) being added to an old
* raid set during takeover to a higher raid level
* to provide capacity for redundancy or during reshape
* to add capacity to grow the raid set.
*/
rdev_for_each(r, mddev) {
if (test_bit(Journal, &rdev->flags))
continue;
if (test_bit(FirstUse, &r->flags))
new_devs++;
if (!test_bit(In_sync, &r->flags)) {
DMINFO("Device %d specified for rebuild; clearing superblock",
r->raid_disk);
rebuilds++;
if (test_bit(FirstUse, &r->flags))
rebuild_and_new++;
}
}
if (new_devs == rs->raid_disks || !rebuilds) {
/* Replace a broken device */
if (new_devs == rs->raid_disks) {
DMINFO("Superblocks created for new raid set");
set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
} else if (new_devs != rebuilds &&
new_devs != rs->delta_disks) {
DMERR("New device injected into existing raid set without "
"'delta_disks' or 'rebuild' parameter specified");
return -EINVAL;
}
} else if (new_devs && new_devs != rebuilds) {
DMERR("%u 'rebuild' devices cannot be injected into"
" a raid set with %u other first-time devices",
rebuilds, new_devs);
return -EINVAL;
} else if (rebuilds) {
if (rebuild_and_new && rebuilds != rebuild_and_new) {
DMERR("new device%s provided without 'rebuild'",
new_devs > 1 ? "s" : "");
return -EINVAL;
} else if (!test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) && rs_is_recovering(rs)) {
DMERR("'rebuild' specified while raid set is not in-sync (recovery_cp=%llu)",
(unsigned long long) mddev->recovery_cp);
return -EINVAL;
} else if (rs_is_reshaping(rs)) {
DMERR("'rebuild' specified while raid set is being reshaped (reshape_position=%llu)",
(unsigned long long) mddev->reshape_position);
return -EINVAL;
}
}
/*
* Now we set the Faulty bit for those devices that are
* recorded in the superblock as failed.
*/
sb_retrieve_failed_devices(sb, failed_devices);
rdev_for_each(r, mddev) {
if (test_bit(Journal, &rdev->flags) ||
!r->sb_page)
continue;
sb2 = page_address(r->sb_page);
sb2->failed_devices = 0;
memset(sb2->extended_failed_devices, 0, sizeof(sb2->extended_failed_devices));
/*
* Check for any device re-ordering.
*/
if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
role = le32_to_cpu(sb2->array_position);
if (role < 0)
continue;
if (role != r->raid_disk) {
if (rs_is_raid10(rs) && __is_raid10_near(mddev->layout)) {
if (mddev->raid_disks % __raid10_near_copies(mddev->layout) ||
rs->raid_disks % rs->raid10_copies) {
rs->ti->error =
"Cannot change raid10 near set to odd # of devices!";
return -EINVAL;
}
sb2->array_position = cpu_to_le32(r->raid_disk);
} else if (!(rs_is_raid10(rs) && rt_is_raid0(rs->raid_type)) &&
!(rs_is_raid0(rs) && rt_is_raid10(rs->raid_type)) &&
!rt_is_raid1(rs->raid_type)) {
rs->ti->error = "Cannot change device positions in raid set";
return -EINVAL;
}
DMINFO("raid device #%d now at position #%d", role, r->raid_disk);
}
/*
* Partial recovery is performed on
* returning failed devices.
*/
if (test_bit(role, (void *) failed_devices))
set_bit(Faulty, &r->flags);
}
}
return 0;
}
static int super_validate(struct raid_set *rs, struct md_rdev *rdev)
{
struct mddev *mddev = &rs->md;
struct dm_raid_superblock *sb;
if (rs_is_raid0(rs) || !rdev->sb_page || rdev->raid_disk < 0)
return 0;
sb = page_address(rdev->sb_page);
/*
* If mddev->events is not set, we know we have not yet initialized
* the array.
*/
if (!mddev->events && super_init_validation(rs, rdev))
return -EINVAL;
if (le32_to_cpu(sb->compat_features) &&
le32_to_cpu(sb->compat_features) != FEATURE_FLAG_SUPPORTS_V190) {
rs->ti->error = "Unable to assemble array: Unknown flag(s) in compatible feature flags";
return -EINVAL;
}
if (sb->incompat_features) {
rs->ti->error = "Unable to assemble array: No incompatible feature flags supported yet";
return -EINVAL;
}
/* Enable bitmap creation on @rs unless no metadevs or raid0 or journaled raid4/5/6 set. */
mddev->bitmap_info.offset = (rt_is_raid0(rs->raid_type) || rs->journal_dev.dev) ? 0 : to_sector(4096);
mddev->bitmap_info.default_offset = mddev->bitmap_info.offset;
if (!test_and_clear_bit(FirstUse, &rdev->flags)) {
/*
* Retrieve rdev size stored in superblock to be prepared for shrink.
* Check extended superblock members are present otherwise the size
* will not be set!
*/
if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190)
rdev->sectors = le64_to_cpu(sb->sectors);
rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
if (rdev->recovery_offset == MaxSector)
set_bit(In_sync, &rdev->flags);
/*
* If no reshape in progress -> we're recovering single
* disk(s) and have to set the device(s) to out-of-sync
*/
else if (!rs_is_reshaping(rs))
clear_bit(In_sync, &rdev->flags); /* Mandatory for recovery */
}
/*
* If a device comes back, set it as not In_sync and no longer faulty.
*/
if (test_and_clear_bit(Faulty, &rdev->flags)) {
rdev->recovery_offset = 0;
clear_bit(In_sync, &rdev->flags);
rdev->saved_raid_disk = rdev->raid_disk;
}
/* Reshape support -> restore repective data offsets */
rdev->data_offset = le64_to_cpu(sb->data_offset);
rdev->new_data_offset = le64_to_cpu(sb->new_data_offset);
return 0;
}
/*
* Analyse superblocks and select the freshest.
*/
static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
{
int r;
struct md_rdev *rdev, *freshest;
struct mddev *mddev = &rs->md;
freshest = NULL;
rdev_for_each(rdev, mddev) {
if (test_bit(Journal, &rdev->flags))
continue;
if (!rdev->meta_bdev)
continue;
/* Set superblock offset/size for metadata device. */
rdev->sb_start = 0;
rdev->sb_size = bdev_logical_block_size(rdev->meta_bdev);
if (rdev->sb_size < sizeof(struct dm_raid_superblock) || rdev->sb_size > PAGE_SIZE) {
DMERR("superblock size of a logical block is no longer valid");
return -EINVAL;
}
/*
* Skipping super_load due to CTR_FLAG_SYNC will cause
* the array to undergo initialization again as
* though it were new. This is the intended effect
* of the "sync" directive.
*
* With reshaping capability added, we must ensure that
* the "sync" directive is disallowed during the reshape.
*/
if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
continue;
r = super_load(rdev, freshest);
switch (r) {
case 1:
freshest = rdev;
break;
case 0:
break;
default:
/* This is a failure to read the superblock from the metadata device. */
/*
* We have to keep any raid0 data/metadata device pairs or
* the MD raid0 personality will fail to start the array.
*/
if (rs_is_raid0(rs))
continue;
/*
* We keep the dm_devs to be able to emit the device tuple
* properly on the table line in raid_status() (rather than
* mistakenly acting as if '- -' got passed into the constructor).
*
* The rdev has to stay on the same_set list to allow for
* the attempt to restore faulty devices on second resume.
*/
rdev->raid_disk = rdev->saved_raid_disk = -1;
break;
}
}
if (!freshest)
return 0;
/*
* Validation of the freshest device provides the source of
* validation for the remaining devices.
*/
rs->ti->error = "Unable to assemble array: Invalid superblocks";
if (super_validate(rs, freshest))
return -EINVAL;
if (validate_raid_redundancy(rs)) {
rs->ti->error = "Insufficient redundancy to activate array";
return -EINVAL;
}
rdev_for_each(rdev, mddev)
if (!test_bit(Journal, &rdev->flags) &&
rdev != freshest &&
super_validate(rs, rdev))
return -EINVAL;
return 0;
}
/*
* Adjust data_offset and new_data_offset on all disk members of @rs
* for out of place reshaping if requested by constructor
*
* We need free space at the beginning of each raid disk for forward
* and at the end for backward reshapes which userspace has to provide
* via remapping/reordering of space.
*/
static int rs_adjust_data_offsets(struct raid_set *rs)
{
sector_t data_offset = 0, new_data_offset = 0;
struct md_rdev *rdev;
/* Constructor did not request data offset change */
if (!test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags)) {
if (!rs_is_reshapable(rs))
goto out;
return 0;
}
/* HM FIXME: get In_Sync raid_dev? */
rdev = &rs->dev[0].rdev;
if (rs->delta_disks < 0) {
/*
* Removing disks (reshaping backwards):
*
* - before reshape: data is at offset 0 and free space
* is at end of each component LV
*
* - after reshape: data is at offset rs->data_offset != 0 on each component LV
*/
data_offset = 0;
new_data_offset = rs->data_offset;
} else if (rs->delta_disks > 0) {
/*
* Adding disks (reshaping forwards):
*
* - before reshape: data is at offset rs->data_offset != 0 and
* free space is at begin of each component LV
*
* - after reshape: data is at offset 0 on each component LV
*/
data_offset = rs->data_offset;
new_data_offset = 0;
} else {
/*
* User space passes in 0 for data offset after having removed reshape space
*
* - or - (data offset != 0)
*
* Changing RAID layout or chunk size -> toggle offsets
*
* - before reshape: data is at offset rs->data_offset 0 and
* free space is at end of each component LV
* -or-
* data is at offset rs->data_offset != 0 and
* free space is at begin of each component LV
*
* - after reshape: data is at offset 0 if it was at offset != 0
* or at offset != 0 if it was at offset 0
* on each component LV
*
*/
data_offset = rs->data_offset ? rdev->data_offset : 0;
new_data_offset = data_offset ? 0 : rs->data_offset;
set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
}
/*
* Make sure we got a minimum amount of free sectors per device
*/
if (rs->data_offset &&
bdev_nr_sectors(rdev->bdev) - rs->md.dev_sectors < MIN_FREE_RESHAPE_SPACE) {
rs->ti->error = data_offset ? "No space for forward reshape" :
"No space for backward reshape";
return -ENOSPC;
}
out:
/*
* Raise recovery_cp in case data_offset != 0 to
* avoid false recovery positives in the constructor.
*/
if (rs->md.recovery_cp < rs->md.dev_sectors)
rs->md.recovery_cp += rs->dev[0].rdev.data_offset;
/* Adjust data offsets on all rdevs but on any raid4/5/6 journal device */
rdev_for_each(rdev, &rs->md) {
if (!test_bit(Journal, &rdev->flags)) {
rdev->data_offset = data_offset;
rdev->new_data_offset = new_data_offset;
}
}
return 0;
}
/* Userpace reordered disks -> adjust raid_disk indexes in @rs */
static void __reorder_raid_disk_indexes(struct raid_set *rs)
{
int i = 0;
struct md_rdev *rdev;
rdev_for_each(rdev, &rs->md) {
if (!test_bit(Journal, &rdev->flags)) {
rdev->raid_disk = i++;
rdev->saved_raid_disk = rdev->new_raid_disk = -1;
}
}
}
/*
* Setup @rs for takeover by a different raid level
*/
static int rs_setup_takeover(struct raid_set *rs)
{
struct mddev *mddev = &rs->md;
struct md_rdev *rdev;
unsigned int d = mddev->raid_disks = rs->raid_disks;
sector_t new_data_offset = rs->dev[0].rdev.data_offset ? 0 : rs->data_offset;
if (rt_is_raid10(rs->raid_type)) {
if (rs_is_raid0(rs)) {
/* Userpace reordered disks -> adjust raid_disk indexes */
__reorder_raid_disk_indexes(rs);
/* raid0 -> raid10_far layout */
mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_FAR,
rs->raid10_copies);
} else if (rs_is_raid1(rs))
/* raid1 -> raid10_near layout */
mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
rs->raid_disks);
else
return -EINVAL;
}
clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
mddev->recovery_cp = MaxSector;
while (d--) {
rdev = &rs->dev[d].rdev;
if (test_bit(d, (void *) rs->rebuild_disks)) {
clear_bit(In_sync, &rdev->flags);
clear_bit(Faulty, &rdev->flags);
mddev->recovery_cp = rdev->recovery_offset = 0;
/* Bitmap has to be created when we do an "up" takeover */
set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
}
rdev->new_data_offset = new_data_offset;
}
return 0;
}
/* Prepare @rs for reshape */
static int rs_prepare_reshape(struct raid_set *rs)
{
bool reshape;
struct mddev *mddev = &rs->md;
if (rs_is_raid10(rs)) {
if (rs->raid_disks != mddev->raid_disks &&
__is_raid10_near(mddev->layout) &&
rs->raid10_copies &&
rs->raid10_copies != __raid10_near_copies(mddev->layout)) {
/*
* raid disk have to be multiple of data copies to allow this conversion,
*
* This is actually not a reshape it is a
* rebuild of any additional mirrors per group
*/
if (rs->raid_disks % rs->raid10_copies) {
rs->ti->error = "Can't reshape raid10 mirror groups";
return -EINVAL;
}
/* Userpace reordered disks to add/remove mirrors -> adjust raid_disk indexes */
__reorder_raid_disk_indexes(rs);
mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
rs->raid10_copies);
mddev->new_layout = mddev->layout;
reshape = false;
} else
reshape = true;
} else if (rs_is_raid456(rs))
reshape = true;
else if (rs_is_raid1(rs)) {
if (rs->delta_disks) {
/* Process raid1 via delta_disks */
mddev->degraded = rs->delta_disks < 0 ? -rs->delta_disks : rs->delta_disks;
reshape = true;
} else {
/* Process raid1 without delta_disks */
mddev->raid_disks = rs->raid_disks;
reshape = false;
}
} else {
rs->ti->error = "Called with bogus raid type";
return -EINVAL;
}
if (reshape) {
set_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags);
set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
} else if (mddev->raid_disks < rs->raid_disks)
/* Create new superblocks and bitmaps, if any new disks */
set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
return 0;
}
/* Get reshape sectors from data_offsets or raid set */
static sector_t _get_reshape_sectors(struct raid_set *rs)
{
struct md_rdev *rdev;
sector_t reshape_sectors = 0;
rdev_for_each(rdev, &rs->md)
if (!test_bit(Journal, &rdev->flags)) {
reshape_sectors = (rdev->data_offset > rdev->new_data_offset) ?
rdev->data_offset - rdev->new_data_offset :
rdev->new_data_offset - rdev->data_offset;
break;
}
return max(reshape_sectors, (sector_t) rs->data_offset);
}
/*
* Reshape:
* - change raid layout
* - change chunk size
* - add disks
* - remove disks
*/
static int rs_setup_reshape(struct raid_set *rs)
{
int r = 0;
unsigned int cur_raid_devs, d;
sector_t reshape_sectors = _get_reshape_sectors(rs);
struct mddev *mddev = &rs->md;
struct md_rdev *rdev;
mddev->delta_disks = rs->delta_disks;
cur_raid_devs = mddev->raid_disks;
/* Ignore impossible layout change whilst adding/removing disks */
if (mddev->delta_disks &&
mddev->layout != mddev->new_layout) {
DMINFO("Ignoring invalid layout change with delta_disks=%d", rs->delta_disks);
mddev->new_layout = mddev->layout;
}
/*
* Adjust array size:
*
* - in case of adding disk(s), array size has
* to grow after the disk adding reshape,
* which'll happen in the event handler;
* reshape will happen forward, so space has to
* be available at the beginning of each disk
*
* - in case of removing disk(s), array size
* has to shrink before starting the reshape,
* which'll happen here;
* reshape will happen backward, so space has to
* be available at the end of each disk
*
* - data_offset and new_data_offset are
* adjusted for aforementioned out of place
* reshaping based on userspace passing in
* the "data_offset <sectors>" key/value
* pair via the constructor
*/
/* Add disk(s) */
if (rs->delta_disks > 0) {
/* Prepare disks for check in raid4/5/6/10 {check|start}_reshape */
for (d = cur_raid_devs; d < rs->raid_disks; d++) {
rdev = &rs->dev[d].rdev;
clear_bit(In_sync, &rdev->flags);
/*
* save_raid_disk needs to be -1, or recovery_offset will be set to 0
* by md, which'll store that erroneously in the superblock on reshape
*/
rdev->saved_raid_disk = -1;
rdev->raid_disk = d;
rdev->sectors = mddev->dev_sectors;
rdev->recovery_offset = rs_is_raid1(rs) ? 0 : MaxSector;
}
mddev->reshape_backwards = 0; /* adding disk(s) -> forward reshape */
/* Remove disk(s) */
} else if (rs->delta_disks < 0) {
r = rs_set_dev_and_array_sectors(rs, rs->ti->len, true);
mddev->reshape_backwards = 1; /* removing disk(s) -> backward reshape */
/* Change layout and/or chunk size */
} else {
/*
* Reshape layout (e.g. raid5_ls -> raid5_n) and/or chunk size:
*
* keeping number of disks and do layout change ->
*
* toggle reshape_backward depending on data_offset:
*
* - free space upfront -> reshape forward
*
* - free space at the end -> reshape backward
*
*
* This utilizes free reshape space avoiding the need
* for userspace to move (parts of) LV segments in
* case of layout/chunksize change (for disk
* adding/removing reshape space has to be at
* the proper address (see above with delta_disks):
*
* add disk(s) -> begin
* remove disk(s)-> end
*/
mddev->reshape_backwards = rs->dev[0].rdev.data_offset ? 0 : 1;
}
/*
* Adjust device size for forward reshape
* because md_finish_reshape() reduces it.
*/
if (!mddev->reshape_backwards)
rdev_for_each(rdev, &rs->md)
if (!test_bit(Journal, &rdev->flags))
rdev->sectors += reshape_sectors;
return r;
}
/*
* If the md resync thread has updated superblock with max reshape position
* at the end of a reshape but not (yet) reset the layout configuration
* changes -> reset the latter.
*/
static void rs_reset_inconclusive_reshape(struct raid_set *rs)
{
if (!rs_is_reshaping(rs) && rs_is_layout_change(rs, true)) {
rs_set_cur(rs);
rs->md.delta_disks = 0;
rs->md.reshape_backwards = 0;
}
}
/*
* Enable/disable discard support on RAID set depending on
* RAID level and discard properties of underlying RAID members.
*/
static void configure_discard_support(struct raid_set *rs)
{
int i;
bool raid456;
struct dm_target *ti = rs->ti;
/*
* XXX: RAID level 4,5,6 require zeroing for safety.
*/
raid456 = rs_is_raid456(rs);
for (i = 0; i < rs->raid_disks; i++) {
if (!rs->dev[i].rdev.bdev ||
!bdev_max_discard_sectors(rs->dev[i].rdev.bdev))
return;
if (raid456) {
if (!devices_handle_discard_safely) {
DMERR("raid456 discard support disabled due to discard_zeroes_data uncertainty.");
DMERR("Set dm-raid.devices_handle_discard_safely=Y to override.");
return;
}
}
}
ti->num_discard_bios = 1;
}
/*
* Construct a RAID0/1/10/4/5/6 mapping:
* Args:
* <raid_type> <#raid_params> <raid_params>{0,} \
* <#raid_devs> [<meta_dev1> <dev1>]{1,}
*
* <raid_params> varies by <raid_type>. See 'parse_raid_params' for
* details on possible <raid_params>.
*
* Userspace is free to initialize the metadata devices, hence the superblocks to
* enforce recreation based on the passed in table parameters.
*
*/
static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
int r;
bool resize = false;
struct raid_type *rt;
unsigned int num_raid_params, num_raid_devs;
sector_t sb_array_sectors, rdev_sectors, reshape_sectors;
struct raid_set *rs = NULL;
const char *arg;
struct rs_layout rs_layout;
struct dm_arg_set as = { argc, argv }, as_nrd;
struct dm_arg _args[] = {
{ 0, as.argc, "Cannot understand number of raid parameters" },
{ 1, 254, "Cannot understand number of raid devices parameters" }
};
arg = dm_shift_arg(&as);
if (!arg) {
ti->error = "No arguments";
return -EINVAL;
}
rt = get_raid_type(arg);
if (!rt) {
ti->error = "Unrecognised raid_type";
return -EINVAL;
}
/* Must have <#raid_params> */
if (dm_read_arg_group(_args, &as, &num_raid_params, &ti->error))
return -EINVAL;
/* number of raid device tupples <meta_dev data_dev> */
as_nrd = as;
dm_consume_args(&as_nrd, num_raid_params);
_args[1].max = (as_nrd.argc - 1) / 2;
if (dm_read_arg(_args + 1, &as_nrd, &num_raid_devs, &ti->error))
return -EINVAL;
if (!__within_range(num_raid_devs, 1, MAX_RAID_DEVICES)) {
ti->error = "Invalid number of supplied raid devices";
return -EINVAL;
}
rs = raid_set_alloc(ti, rt, num_raid_devs);
if (IS_ERR(rs))
return PTR_ERR(rs);
r = parse_raid_params(rs, &as, num_raid_params);
if (r)
goto bad;
r = parse_dev_params(rs, &as);
if (r)
goto bad;
rs->md.sync_super = super_sync;
/*
* Calculate ctr requested array and device sizes to allow
* for superblock analysis needing device sizes defined.
*
* Any existing superblock will overwrite the array and device sizes
*/
r = rs_set_dev_and_array_sectors(rs, rs->ti->len, false);
if (r)
goto bad;
/* Memorize just calculated, potentially larger sizes to grow the raid set in preresume */
rs->array_sectors = rs->md.array_sectors;
rs->dev_sectors = rs->md.dev_sectors;
/*
* Backup any new raid set level, layout, ...
* requested to be able to compare to superblock
* members for conversion decisions.
*/
rs_config_backup(rs, &rs_layout);
r = analyse_superblocks(ti, rs);
if (r)
goto bad;
/* All in-core metadata now as of current superblocks after calling analyse_superblocks() */
sb_array_sectors = rs->md.array_sectors;
rdev_sectors = __rdev_sectors(rs);
if (!rdev_sectors) {
ti->error = "Invalid rdev size";
r = -EINVAL;
goto bad;
}
reshape_sectors = _get_reshape_sectors(rs);
if (rs->dev_sectors != rdev_sectors) {
resize = (rs->dev_sectors != rdev_sectors - reshape_sectors);
if (rs->dev_sectors > rdev_sectors - reshape_sectors)
set_bit(RT_FLAG_RS_GROW, &rs->runtime_flags);
}
INIT_WORK(&rs->md.event_work, do_table_event);
ti->private = rs;
ti->num_flush_bios = 1;
ti->needs_bio_set_dev = true;
/* Restore any requested new layout for conversion decision */
rs_config_restore(rs, &rs_layout);
/*
* Now that we have any superblock metadata available,
* check for new, recovering, reshaping, to be taken over,
* to be reshaped or an existing, unchanged raid set to
* run in sequence.
*/
if (test_bit(MD_ARRAY_FIRST_USE, &rs->md.flags)) {
/* A new raid6 set has to be recovered to ensure proper parity and Q-Syndrome */
if (rs_is_raid6(rs) &&
test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
ti->error = "'nosync' not allowed for new raid6 set";
r = -EINVAL;
goto bad;
}
rs_setup_recovery(rs, 0);
set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
rs_set_new(rs);
} else if (rs_is_recovering(rs)) {
/* A recovering raid set may be resized */
goto size_check;
} else if (rs_is_reshaping(rs)) {
/* Have to reject size change request during reshape */
if (resize) {
ti->error = "Can't resize a reshaping raid set";
r = -EPERM;
goto bad;
}
/* skip setup rs */
} else if (rs_takeover_requested(rs)) {
if (rs_is_reshaping(rs)) {
ti->error = "Can't takeover a reshaping raid set";
r = -EPERM;
goto bad;
}
/* We can't takeover a journaled raid4/5/6 */
if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
ti->error = "Can't takeover a journaled raid4/5/6 set";
r = -EPERM;
goto bad;
}
/*
* If a takeover is needed, userspace sets any additional
* devices to rebuild and we can check for a valid request here.
*
* If acceptable, set the level to the new requested
* one, prohibit requesting recovery, allow the raid
* set to run and store superblocks during resume.
*/
r = rs_check_takeover(rs);
if (r)
goto bad;
r = rs_setup_takeover(rs);
if (r)
goto bad;
set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
/* Takeover ain't recovery, so disable recovery */
rs_setup_recovery(rs, MaxSector);
rs_set_new(rs);
} else if (rs_reshape_requested(rs)) {
/* Only request grow on raid set size extensions, not on reshapes. */
clear_bit(RT_FLAG_RS_GROW, &rs->runtime_flags);
/*
* No need to check for 'ongoing' takeover here, because takeover
* is an instant operation as oposed to an ongoing reshape.
*/
/* We can't reshape a journaled raid4/5/6 */
if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
ti->error = "Can't reshape a journaled raid4/5/6 set";
r = -EPERM;
goto bad;
}
/* Out-of-place space has to be available to allow for a reshape unless raid1! */
if (reshape_sectors || rs_is_raid1(rs)) {
/*
* We can only prepare for a reshape here, because the
* raid set needs to run to provide the repective reshape
* check functions via its MD personality instance.
*
* So do the reshape check after md_run() succeeded.
*/
r = rs_prepare_reshape(rs);
if (r)
goto bad;
/* Reshaping ain't recovery, so disable recovery */
rs_setup_recovery(rs, MaxSector);
}
rs_set_cur(rs);
} else {
size_check:
/* May not set recovery when a device rebuild is requested */
if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags)) {
clear_bit(RT_FLAG_RS_GROW, &rs->runtime_flags);
set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
rs_setup_recovery(rs, MaxSector);
} else if (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags)) {
/*
* Set raid set to current size, i.e. size as of
* superblocks to grow to larger size in preresume.
*/
r = rs_set_dev_and_array_sectors(rs, sb_array_sectors, false);
if (r)
goto bad;
rs_setup_recovery(rs, rs->md.recovery_cp < rs->md.dev_sectors ? rs->md.recovery_cp : rs->md.dev_sectors);
} else {
/* This is no size change or it is shrinking, update size and record in superblocks */
r = rs_set_dev_and_array_sectors(rs, rs->ti->len, false);
if (r)
goto bad;
if (sb_array_sectors > rs->array_sectors)
set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
}
rs_set_cur(rs);
}
/* If constructor requested it, change data and new_data offsets */
r = rs_adjust_data_offsets(rs);
if (r)
goto bad;
/* Catch any inconclusive reshape superblock content. */
rs_reset_inconclusive_reshape(rs);
/* Start raid set read-only and assumed clean to change in raid_resume() */
rs->md.ro = 1;
rs->md.in_sync = 1;
/* Keep array frozen until resume. */
set_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
/* Has to be held on running the array */
mddev_lock_nointr(&rs->md);
r = md_run(&rs->md);
rs->md.in_sync = 0; /* Assume already marked dirty */
if (r) {
ti->error = "Failed to run raid array";
mddev_unlock(&rs->md);
goto bad;
}
r = md_start(&rs->md);
if (r) {
ti->error = "Failed to start raid array";
goto bad_unlock;
}
/* If raid4/5/6 journal mode explicitly requested (only possible with journal dev) -> set it */
if (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags)) {
r = r5c_journal_mode_set(&rs->md, rs->journal_dev.mode);
if (r) {
ti->error = "Failed to set raid4/5/6 journal mode";
goto bad_unlock;
}
}
mddev_suspend(&rs->md);
set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags);
/* Try to adjust the raid4/5/6 stripe cache size to the stripe size */
if (rs_is_raid456(rs)) {
r = rs_set_raid456_stripe_cache(rs);
if (r)
goto bad_unlock;
}
/* Now do an early reshape check */
if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
r = rs_check_reshape(rs);
if (r)
goto bad_unlock;
/* Restore new, ctr requested layout to perform check */
rs_config_restore(rs, &rs_layout);
if (rs->md.pers->start_reshape) {
r = rs->md.pers->check_reshape(&rs->md);
if (r) {
ti->error = "Reshape check failed";
goto bad_unlock;
}
}
}
/* Disable/enable discard support on raid set. */
configure_discard_support(rs);
mddev_unlock(&rs->md);
return 0;
bad_unlock:
md_stop(&rs->md);
mddev_unlock(&rs->md);
bad:
raid_set_free(rs);
return r;
}
static void raid_dtr(struct dm_target *ti)
{
struct raid_set *rs = ti->private;
mddev_lock_nointr(&rs->md);
md_stop(&rs->md);
mddev_unlock(&rs->md);
raid_set_free(rs);
}
static int raid_map(struct dm_target *ti, struct bio *bio)
{
struct raid_set *rs = ti->private;
struct mddev *mddev = &rs->md;
/*
* If we're reshaping to add disk(s)), ti->len and
* mddev->array_sectors will differ during the process
* (ti->len > mddev->array_sectors), so we have to requeue
* bios with addresses > mddev->array_sectors here or
* there will occur accesses past EOD of the component
* data images thus erroring the raid set.
*/
if (unlikely(bio_end_sector(bio) > mddev->array_sectors))
return DM_MAPIO_REQUEUE;
md_handle_request(mddev, bio);
return DM_MAPIO_SUBMITTED;
}
/* Return sync state string for @state */
enum sync_state { st_frozen, st_reshape, st_resync, st_check, st_repair, st_recover, st_idle };
static const char *sync_str(enum sync_state state)
{
/* Has to be in above sync_state order! */
static const char *sync_strs[] = {
"frozen",
"reshape",
"resync",
"check",
"repair",
"recover",
"idle"
};
return __within_range(state, 0, ARRAY_SIZE(sync_strs) - 1) ? sync_strs[state] : "undef";
};
/* Return enum sync_state for @mddev derived from @recovery flags */
static enum sync_state decipher_sync_action(struct mddev *mddev, unsigned long recovery)
{
if (test_bit(MD_RECOVERY_FROZEN, &recovery))
return st_frozen;
/* The MD sync thread can be done with io or be interrupted but still be running */
if (!test_bit(MD_RECOVERY_DONE, &recovery) &&
(test_bit(MD_RECOVERY_RUNNING, &recovery) ||
(!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &recovery)))) {
if (test_bit(MD_RECOVERY_RESHAPE, &recovery))
return st_reshape;
if (test_bit(MD_RECOVERY_SYNC, &recovery)) {
if (!test_bit(MD_RECOVERY_REQUESTED, &recovery))
return st_resync;
if (test_bit(MD_RECOVERY_CHECK, &recovery))
return st_check;
return st_repair;
}
if (test_bit(MD_RECOVERY_RECOVER, &recovery))
return st_recover;
if (mddev->reshape_position != MaxSector)
return st_reshape;
}
return st_idle;
}
/*
* Return status string for @rdev
*
* Status characters:
*
* 'D' = Dead/Failed raid set component or raid4/5/6 journal device
* 'a' = Alive but not in-sync raid set component _or_ alive raid4/5/6 'write_back' journal device
* 'A' = Alive and in-sync raid set component _or_ alive raid4/5/6 'write_through' journal device
* '-' = Non-existing device (i.e. uspace passed '- -' into the ctr)
*/
static const char *__raid_dev_status(struct raid_set *rs, struct md_rdev *rdev)
{
if (!rdev->bdev)
return "-";
else if (test_bit(Faulty, &rdev->flags))
return "D";
else if (test_bit(Journal, &rdev->flags))
return (rs->journal_dev.mode == R5C_JOURNAL_MODE_WRITE_THROUGH) ? "A" : "a";
else if (test_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags) ||
(!test_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags) &&
!test_bit(In_sync, &rdev->flags)))
return "a";
else
return "A";
}
/* Helper to return resync/reshape progress for @rs and runtime flags for raid set in sync / resynching */
static sector_t rs_get_progress(struct raid_set *rs, unsigned long recovery,
enum sync_state state, sector_t resync_max_sectors)
{
sector_t r;
struct mddev *mddev = &rs->md;
clear_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
clear_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
if (rs_is_raid0(rs)) {
r = resync_max_sectors;
set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
} else {
if (state == st_idle && !test_bit(MD_RECOVERY_INTR, &recovery))
r = mddev->recovery_cp;
else
r = mddev->curr_resync_completed;
if (state == st_idle && r >= resync_max_sectors) {
/*
* Sync complete.
*/
/* In case we have finished recovering, the array is in sync. */
if (test_bit(MD_RECOVERY_RECOVER, &recovery))
set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
} else if (state == st_recover)
/*
* In case we are recovering, the array is not in sync
* and health chars should show the recovering legs.
*
* Already retrieved recovery offset from curr_resync_completed above.
*/
;
else if (state == st_resync || state == st_reshape)
/*
* If "resync/reshape" is occurring, the raid set
* is or may be out of sync hence the health
* characters shall be 'a'.
*/
set_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
else if (state == st_check || state == st_repair)
/*
* If "check" or "repair" is occurring, the raid set has
* undergone an initial sync and the health characters
* should not be 'a' anymore.
*/
set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
else if (test_bit(MD_RECOVERY_NEEDED, &recovery))
/*
* We are idle and recovery is needed, prevent 'A' chars race
* caused by components still set to in-sync by constructor.
*/
set_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
else {
/*
* We are idle and the raid set may be doing an initial
* sync, or it may be rebuilding individual components.
* If all the devices are In_sync, then it is the raid set
* that is being initialized.
*/
struct md_rdev *rdev;
set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
rdev_for_each(rdev, mddev)
if (!test_bit(Journal, &rdev->flags) &&
!test_bit(In_sync, &rdev->flags)) {
clear_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
break;
}
}
}
return min(r, resync_max_sectors);
}
/* Helper to return @dev name or "-" if !@dev */
static const char *__get_dev_name(struct dm_dev *dev)
{
return dev ? dev->name : "-";
}
static void raid_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
struct raid_set *rs = ti->private;
struct mddev *mddev = &rs->md;
struct r5conf *conf = rs_is_raid456(rs) ? mddev->private : NULL;
int i, max_nr_stripes = conf ? conf->max_nr_stripes : 0;
unsigned long recovery;
unsigned int raid_param_cnt = 1; /* at least 1 for chunksize */
unsigned int sz = 0;
unsigned int rebuild_writemostly_count = 0;
sector_t progress, resync_max_sectors, resync_mismatches;
enum sync_state state;
struct raid_type *rt;
switch (type) {
case STATUSTYPE_INFO:
/* *Should* always succeed */
rt = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
if (!rt)
return;
DMEMIT("%s %d ", rt->name, mddev->raid_disks);
/* Access most recent mddev properties for status output */
smp_rmb();
/* Get sensible max sectors even if raid set not yet started */
resync_max_sectors = test_bit(RT_FLAG_RS_PRERESUMED, &rs->runtime_flags) ?
mddev->resync_max_sectors : mddev->dev_sectors;
recovery = rs->md.recovery;
state = decipher_sync_action(mddev, recovery);
progress = rs_get_progress(rs, recovery, state, resync_max_sectors);
resync_mismatches = (mddev->last_sync_action && !strcasecmp(mddev->last_sync_action, "check")) ?
atomic64_read(&mddev->resync_mismatches) : 0;
/* HM FIXME: do we want another state char for raid0? It shows 'D'/'A'/'-' now */
for (i = 0; i < rs->raid_disks; i++)
DMEMIT(__raid_dev_status(rs, &rs->dev[i].rdev));
/*
* In-sync/Reshape ratio:
* The in-sync ratio shows the progress of:
* - Initializing the raid set
* - Rebuilding a subset of devices of the raid set
* The user can distinguish between the two by referring
* to the status characters.
*
* The reshape ratio shows the progress of
* changing the raid layout or the number of
* disks of a raid set
*/
DMEMIT(" %llu/%llu", (unsigned long long) progress,
(unsigned long long) resync_max_sectors);
/*
* v1.5.0+:
*
* Sync action:
* See Documentation/admin-guide/device-mapper/dm-raid.rst for
* information on each of these states.
*/
DMEMIT(" %s", sync_str(state));
/*
* v1.5.0+:
*
* resync_mismatches/mismatch_cnt
* This field shows the number of discrepancies found when
* performing a "check" of the raid set.
*/
DMEMIT(" %llu", (unsigned long long) resync_mismatches);
/*
* v1.9.0+:
*
* data_offset (needed for out of space reshaping)
* This field shows the data offset into the data
* image LV where the first stripes data starts.
*
* We keep data_offset equal on all raid disks of the set,
* so retrieving it from the first raid disk is sufficient.
*/
DMEMIT(" %llu", (unsigned long long) rs->dev[0].rdev.data_offset);
/*
* v1.10.0+:
*/
DMEMIT(" %s", test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags) ?
__raid_dev_status(rs, &rs->journal_dev.rdev) : "-");
break;
case STATUSTYPE_TABLE:
/* Report the table line string you would use to construct this raid set */
/*
* Count any rebuild or writemostly argument pairs and subtract the
* hweight count being added below of any rebuild and writemostly ctr flags.
*/
for (i = 0; i < rs->raid_disks; i++) {
rebuild_writemostly_count += (test_bit(i, (void *) rs->rebuild_disks) ? 2 : 0) +
(test_bit(WriteMostly, &rs->dev[i].rdev.flags) ? 2 : 0);
}
rebuild_writemostly_count -= (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) ? 2 : 0) +
(test_bit(__CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags) ? 2 : 0);
/* Calculate raid parameter count based on ^ rebuild/writemostly argument counts and ctr flags set. */
raid_param_cnt += rebuild_writemostly_count +
hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_NO_ARGS) +
hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_ONE_ARG) * 2;
/* Emit table line */
/* This has to be in the documented order for userspace! */
DMEMIT("%s %u %u", rs->raid_type->name, raid_param_cnt, mddev->new_chunk_sectors);
if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_SYNC));
if (test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC));
if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags))
for (i = 0; i < rs->raid_disks; i++)
if (test_bit(i, (void *) rs->rebuild_disks))
DMEMIT(" %s %u", dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD), i);
if (test_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags))
DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP),
mddev->bitmap_info.daemon_sleep);
if (test_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags))
DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE),
mddev->sync_speed_min);
if (test_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags))
DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE),
mddev->sync_speed_max);
if (test_bit(__CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags))
for (i = 0; i < rs->raid_disks; i++)
if (test_bit(WriteMostly, &rs->dev[i].rdev.flags))
DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY),
rs->dev[i].rdev.raid_disk);
if (test_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags))
DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND),
mddev->bitmap_info.max_write_behind);
if (test_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags))
DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE),
max_nr_stripes);
if (test_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags))
DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE),
(unsigned long long) to_sector(mddev->bitmap_info.chunksize));
if (test_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags))
DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES),
raid10_md_layout_to_copies(mddev->layout));
if (test_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags))
DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT),
raid10_md_layout_to_format(mddev->layout));
if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags))
DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS),
max(rs->delta_disks, mddev->delta_disks));
if (test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags))
DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET),
(unsigned long long) rs->data_offset);
if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags))
DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_DEV),
__get_dev_name(rs->journal_dev.dev));
if (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags))
DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_MODE),
md_journal_mode_to_dm_raid(rs->journal_dev.mode));
DMEMIT(" %d", rs->raid_disks);
for (i = 0; i < rs->raid_disks; i++)
DMEMIT(" %s %s", __get_dev_name(rs->dev[i].meta_dev),
__get_dev_name(rs->dev[i].data_dev));
break;
case STATUSTYPE_IMA:
rt = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
if (!rt)
return;
DMEMIT_TARGET_NAME_VERSION(ti->type);
DMEMIT(",raid_type=%s,raid_disks=%d", rt->name, mddev->raid_disks);
/* Access most recent mddev properties for status output */
smp_rmb();
recovery = rs->md.recovery;
state = decipher_sync_action(mddev, recovery);
DMEMIT(",raid_state=%s", sync_str(state));
for (i = 0; i < rs->raid_disks; i++) {
DMEMIT(",raid_device_%d_status=", i);
DMEMIT(__raid_dev_status(rs, &rs->dev[i].rdev));
}
if (rt_is_raid456(rt)) {
DMEMIT(",journal_dev_mode=");
switch (rs->journal_dev.mode) {
case R5C_JOURNAL_MODE_WRITE_THROUGH:
DMEMIT("%s",
_raid456_journal_mode[R5C_JOURNAL_MODE_WRITE_THROUGH].param);
break;
case R5C_JOURNAL_MODE_WRITE_BACK:
DMEMIT("%s",
_raid456_journal_mode[R5C_JOURNAL_MODE_WRITE_BACK].param);
break;
default:
DMEMIT("invalid");
break;
}
}
DMEMIT(";");
break;
}
}
static int raid_message(struct dm_target *ti, unsigned int argc, char **argv,
char *result, unsigned int maxlen)
{
struct raid_set *rs = ti->private;
struct mddev *mddev = &rs->md;
if (!mddev->pers || !mddev->pers->sync_request)
return -EINVAL;
if (!strcasecmp(argv[0], "frozen"))
set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
else
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
if (!strcasecmp(argv[0], "idle") || !strcasecmp(argv[0], "frozen")) {
if (mddev->sync_thread) {
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
md_reap_sync_thread(mddev);
}
} else if (decipher_sync_action(mddev, mddev->recovery) != st_idle)
return -EBUSY;
else if (!strcasecmp(argv[0], "resync"))
; /* MD_RECOVERY_NEEDED set below */
else if (!strcasecmp(argv[0], "recover"))
set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
else {
if (!strcasecmp(argv[0], "check")) {
set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
} else if (!strcasecmp(argv[0], "repair")) {
set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
} else
return -EINVAL;
}
if (mddev->ro == 2) {
/* A write to sync_action is enough to justify
* canceling read-auto mode
*/
mddev->ro = 0;
if (!mddev->suspended)
md_wakeup_thread(mddev->sync_thread);
}
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
if (!mddev->suspended)
md_wakeup_thread(mddev->thread);
return 0;
}
static int raid_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct raid_set *rs = ti->private;
unsigned int i;
int r = 0;
for (i = 0; !r && i < rs->raid_disks; i++) {
if (rs->dev[i].data_dev) {
r = fn(ti, rs->dev[i].data_dev,
0, /* No offset on data devs */
rs->md.dev_sectors, data);
}
}
return r;
}
static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
struct raid_set *rs = ti->private;
unsigned int chunk_size_bytes = to_bytes(rs->md.chunk_sectors);
blk_limits_io_min(limits, chunk_size_bytes);
blk_limits_io_opt(limits, chunk_size_bytes * mddev_data_stripes(rs));
}
static void raid_postsuspend(struct dm_target *ti)
{
struct raid_set *rs = ti->private;
if (!test_and_set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) {
/* Writes have to be stopped before suspending to avoid deadlocks. */
if (!test_bit(MD_RECOVERY_FROZEN, &rs->md.recovery))
md_stop_writes(&rs->md);
mddev_lock_nointr(&rs->md);
mddev_suspend(&rs->md);
mddev_unlock(&rs->md);
}
}
static void attempt_restore_of_faulty_devices(struct raid_set *rs)
{
int i;
uint64_t cleared_failed_devices[DISKS_ARRAY_ELEMS];
unsigned long flags;
bool cleared = false;
struct dm_raid_superblock *sb;
struct mddev *mddev = &rs->md;
struct md_rdev *r;
/* RAID personalities have to provide hot add/remove methods or we need to bail out. */
if (!mddev->pers || !mddev->pers->hot_add_disk || !mddev->pers->hot_remove_disk)
return;
memset(cleared_failed_devices, 0, sizeof(cleared_failed_devices));
for (i = 0; i < rs->raid_disks; i++) {
r = &rs->dev[i].rdev;
/* HM FIXME: enhance journal device recovery processing */
if (test_bit(Journal, &r->flags))
continue;
if (test_bit(Faulty, &r->flags) &&
r->meta_bdev && !read_disk_sb(r, r->sb_size, true)) {
DMINFO("Faulty %s device #%d has readable super block."
" Attempting to revive it.",
rs->raid_type->name, i);
/*
* Faulty bit may be set, but sometimes the array can
* be suspended before the personalities can respond
* by removing the device from the array (i.e. calling
* 'hot_remove_disk'). If they haven't yet removed
* the failed device, its 'raid_disk' number will be
* '>= 0' - meaning we must call this function
* ourselves.
*/
flags = r->flags;
clear_bit(In_sync, &r->flags); /* Mandatory for hot remove. */
if (r->raid_disk >= 0) {
if (mddev->pers->hot_remove_disk(mddev, r)) {
/* Failed to revive this device, try next */
r->flags = flags;
continue;
}
} else
r->raid_disk = r->saved_raid_disk = i;
clear_bit(Faulty, &r->flags);
clear_bit(WriteErrorSeen, &r->flags);
if (mddev->pers->hot_add_disk(mddev, r)) {
/* Failed to revive this device, try next */
r->raid_disk = r->saved_raid_disk = -1;
r->flags = flags;
} else {
clear_bit(In_sync, &r->flags);
r->recovery_offset = 0;
set_bit(i, (void *) cleared_failed_devices);
cleared = true;
}
}
}
/* If any failed devices could be cleared, update all sbs failed_devices bits */
if (cleared) {
uint64_t failed_devices[DISKS_ARRAY_ELEMS];
rdev_for_each(r, &rs->md) {
if (test_bit(Journal, &r->flags))
continue;
sb = page_address(r->sb_page);
sb_retrieve_failed_devices(sb, failed_devices);
for (i = 0; i < DISKS_ARRAY_ELEMS; i++)
failed_devices[i] &= ~cleared_failed_devices[i];
sb_update_failed_devices(sb, failed_devices);
}
}
}
static int __load_dirty_region_bitmap(struct raid_set *rs)
{
int r = 0;
/* Try loading the bitmap unless "raid0", which does not have one */
if (!rs_is_raid0(rs) &&
!test_and_set_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags)) {
r = md_bitmap_load(&rs->md);
if (r)
DMERR("Failed to load bitmap");
}
return r;
}
/* Enforce updating all superblocks */
static void rs_update_sbs(struct raid_set *rs)
{
struct mddev *mddev = &rs->md;
int ro = mddev->ro;
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
mddev->ro = 0;
md_update_sb(mddev, 1);
mddev->ro = ro;
}
/*
* Reshape changes raid algorithm of @rs to new one within personality
* (e.g. raid6_zr -> raid6_nc), changes stripe size, adds/removes
* disks from a raid set thus growing/shrinking it or resizes the set
*
* Call mddev_lock_nointr() before!
*/
static int rs_start_reshape(struct raid_set *rs)
{
int r;
struct mddev *mddev = &rs->md;
struct md_personality *pers = mddev->pers;
/* Don't allow the sync thread to work until the table gets reloaded. */
set_bit(MD_RECOVERY_WAIT, &mddev->recovery);
r = rs_setup_reshape(rs);
if (r)
return r;
/*
* Check any reshape constraints enforced by the personalility
*
* May as well already kick the reshape off so that * pers->start_reshape() becomes optional.
*/
r = pers->check_reshape(mddev);
if (r) {
rs->ti->error = "pers->check_reshape() failed";
return r;
}
/*
* Personality may not provide start reshape method in which
* case check_reshape above has already covered everything
*/
if (pers->start_reshape) {
r = pers->start_reshape(mddev);
if (r) {
rs->ti->error = "pers->start_reshape() failed";
return r;
}
}
/*
* Now reshape got set up, update superblocks to
* reflect the fact so that a table reload will
* access proper superblock content in the ctr.
*/
rs_update_sbs(rs);
return 0;
}
static int raid_preresume(struct dm_target *ti)
{
int r;
struct raid_set *rs = ti->private;
struct mddev *mddev = &rs->md;
/* This is a resume after a suspend of the set -> it's already started. */
if (test_and_set_bit(RT_FLAG_RS_PRERESUMED, &rs->runtime_flags))
return 0;
/*
* The superblocks need to be updated on disk if the
* array is new or new devices got added (thus zeroed
* out by userspace) or __load_dirty_region_bitmap
* will overwrite them in core with old data or fail.
*/
if (test_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags))
rs_update_sbs(rs);
/* Load the bitmap from disk unless raid0 */
r = __load_dirty_region_bitmap(rs);
if (r)
return r;
/* We are extending the raid set size, adjust mddev/md_rdev sizes and set capacity. */
if (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags)) {
mddev->array_sectors = rs->array_sectors;
mddev->dev_sectors = rs->dev_sectors;
rs_set_rdev_sectors(rs);
rs_set_capacity(rs);
}
/* Resize bitmap to adjust to changed region size (aka MD bitmap chunksize) or grown device size */
if (test_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags) && mddev->bitmap &&
(test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags) ||
(rs->requested_bitmap_chunk_sectors &&
mddev->bitmap_info.chunksize != to_bytes(rs->requested_bitmap_chunk_sectors)))) {
int chunksize = to_bytes(rs->requested_bitmap_chunk_sectors) ?: mddev->bitmap_info.chunksize;
r = md_bitmap_resize(mddev->bitmap, mddev->dev_sectors, chunksize, 0);
if (r)
DMERR("Failed to resize bitmap");
}
/* Check for any resize/reshape on @rs and adjust/initiate */
/* Be prepared for mddev_resume() in raid_resume() */
set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
if (mddev->recovery_cp && mddev->recovery_cp < MaxSector) {
set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
mddev->resync_min = mddev->recovery_cp;
if (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags))
mddev->resync_max_sectors = mddev->dev_sectors;
}
/* Check for any reshape request unless new raid set */
if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
/* Initiate a reshape. */
rs_set_rdev_sectors(rs);
mddev_lock_nointr(mddev);
r = rs_start_reshape(rs);
mddev_unlock(mddev);
if (r)
DMWARN("Failed to check/start reshape, continuing without change");
r = 0;
}
return r;
}
static void raid_resume(struct dm_target *ti)
{
struct raid_set *rs = ti->private;
struct mddev *mddev = &rs->md;
if (test_and_set_bit(RT_FLAG_RS_RESUMED, &rs->runtime_flags)) {
/*
* A secondary resume while the device is active.
* Take this opportunity to check whether any failed
* devices are reachable again.
*/
attempt_restore_of_faulty_devices(rs);
}
if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) {
/* Only reduce raid set size before running a disk removing reshape. */
if (mddev->delta_disks < 0)
rs_set_capacity(rs);
mddev_lock_nointr(mddev);
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
mddev->ro = 0;
mddev->in_sync = 0;
mddev_resume(mddev);
mddev_unlock(mddev);
}
}
static struct target_type raid_target = {
.name = "raid",
.version = {1, 15, 1},
.module = THIS_MODULE,
.ctr = raid_ctr,
.dtr = raid_dtr,
.map = raid_map,
.status = raid_status,
.message = raid_message,
.iterate_devices = raid_iterate_devices,
.io_hints = raid_io_hints,
.postsuspend = raid_postsuspend,
.preresume = raid_preresume,
.resume = raid_resume,
};
module_dm(raid);
module_param(devices_handle_discard_safely, bool, 0644);
MODULE_PARM_DESC(devices_handle_discard_safely,
"Set to Y if all devices in each array reliably return zeroes on reads from discarded regions");
MODULE_DESCRIPTION(DM_NAME " raid0/1/10/4/5/6 target");
MODULE_ALIAS("dm-raid0");
MODULE_ALIAS("dm-raid1");
MODULE_ALIAS("dm-raid10");
MODULE_ALIAS("dm-raid4");
MODULE_ALIAS("dm-raid5");
MODULE_ALIAS("dm-raid6");
MODULE_AUTHOR("Neil Brown <[email protected]>");
MODULE_AUTHOR("Heinz Mauelshagen <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-raid.c |
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Device Mapper Uevent Support (dm-uevent)
*
* Copyright IBM Corporation, 2007
* Author: Mike Anderson <[email protected]>
*/
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/kobject.h>
#include <linux/dm-ioctl.h>
#include <linux/export.h>
#include "dm.h"
#include "dm-uevent.h"
#define DM_MSG_PREFIX "uevent"
static const struct {
enum dm_uevent_type type;
enum kobject_action action;
char *name;
} _dm_uevent_type_names[] = {
{DM_UEVENT_PATH_FAILED, KOBJ_CHANGE, "PATH_FAILED"},
{DM_UEVENT_PATH_REINSTATED, KOBJ_CHANGE, "PATH_REINSTATED"},
};
static struct kmem_cache *_dm_event_cache;
struct dm_uevent {
struct mapped_device *md;
enum kobject_action action;
struct kobj_uevent_env ku_env;
struct list_head elist;
char name[DM_NAME_LEN];
char uuid[DM_UUID_LEN];
};
static void dm_uevent_free(struct dm_uevent *event)
{
kmem_cache_free(_dm_event_cache, event);
}
static struct dm_uevent *dm_uevent_alloc(struct mapped_device *md)
{
struct dm_uevent *event;
event = kmem_cache_zalloc(_dm_event_cache, GFP_ATOMIC);
if (!event)
return NULL;
INIT_LIST_HEAD(&event->elist);
event->md = md;
return event;
}
static struct dm_uevent *dm_build_path_uevent(struct mapped_device *md,
struct dm_target *ti,
enum kobject_action action,
const char *dm_action,
const char *path,
unsigned int nr_valid_paths)
{
struct dm_uevent *event;
event = dm_uevent_alloc(md);
if (!event) {
DMERR("%s: dm_uevent_alloc() failed", __func__);
goto err_nomem;
}
event->action = action;
if (add_uevent_var(&event->ku_env, "DM_TARGET=%s", ti->type->name)) {
DMERR("%s: add_uevent_var() for DM_TARGET failed",
__func__);
goto err_add;
}
if (add_uevent_var(&event->ku_env, "DM_ACTION=%s", dm_action)) {
DMERR("%s: add_uevent_var() for DM_ACTION failed",
__func__);
goto err_add;
}
if (add_uevent_var(&event->ku_env, "DM_SEQNUM=%u",
dm_next_uevent_seq(md))) {
DMERR("%s: add_uevent_var() for DM_SEQNUM failed",
__func__);
goto err_add;
}
if (add_uevent_var(&event->ku_env, "DM_PATH=%s", path)) {
DMERR("%s: add_uevent_var() for DM_PATH failed", __func__);
goto err_add;
}
if (add_uevent_var(&event->ku_env, "DM_NR_VALID_PATHS=%d",
nr_valid_paths)) {
DMERR("%s: add_uevent_var() for DM_NR_VALID_PATHS failed",
__func__);
goto err_add;
}
return event;
err_add:
dm_uevent_free(event);
err_nomem:
return ERR_PTR(-ENOMEM);
}
/**
* dm_send_uevents - send uevents for given list
*
* @events: list of events to send
* @kobj: kobject generating event
*
*/
void dm_send_uevents(struct list_head *events, struct kobject *kobj)
{
int r;
struct dm_uevent *event, *next;
list_for_each_entry_safe(event, next, events, elist) {
list_del_init(&event->elist);
/*
* When a device is being removed this copy fails and we
* discard these unsent events.
*/
if (dm_copy_name_and_uuid(event->md, event->name,
event->uuid)) {
DMINFO("%s: skipping sending uevent for lost device",
__func__);
goto uevent_free;
}
if (add_uevent_var(&event->ku_env, "DM_NAME=%s", event->name)) {
DMERR("%s: add_uevent_var() for DM_NAME failed",
__func__);
goto uevent_free;
}
if (add_uevent_var(&event->ku_env, "DM_UUID=%s", event->uuid)) {
DMERR("%s: add_uevent_var() for DM_UUID failed",
__func__);
goto uevent_free;
}
r = kobject_uevent_env(kobj, event->action, event->ku_env.envp);
if (r)
DMERR("%s: kobject_uevent_env failed", __func__);
uevent_free:
dm_uevent_free(event);
}
}
EXPORT_SYMBOL_GPL(dm_send_uevents);
/**
* dm_path_uevent - called to create a new path event and queue it
*
* @event_type: path event type enum
* @ti: pointer to a dm_target
* @path: string containing pathname
* @nr_valid_paths: number of valid paths remaining
*
*/
void dm_path_uevent(enum dm_uevent_type event_type, struct dm_target *ti,
const char *path, unsigned int nr_valid_paths)
{
struct mapped_device *md = dm_table_get_md(ti->table);
struct dm_uevent *event;
if (event_type >= ARRAY_SIZE(_dm_uevent_type_names)) {
DMERR("%s: Invalid event_type %d", __func__, event_type);
return;
}
event = dm_build_path_uevent(md, ti,
_dm_uevent_type_names[event_type].action,
_dm_uevent_type_names[event_type].name,
path, nr_valid_paths);
if (IS_ERR(event))
return;
dm_uevent_add(md, &event->elist);
}
EXPORT_SYMBOL_GPL(dm_path_uevent);
int dm_uevent_init(void)
{
_dm_event_cache = KMEM_CACHE(dm_uevent, 0);
if (!_dm_event_cache)
return -ENOMEM;
DMINFO("version 1.0.3");
return 0;
}
void dm_uevent_exit(void)
{
kmem_cache_destroy(_dm_event_cache);
}
| linux-master | drivers/md/dm-uevent.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2020 Red Hat GmbH
*
* This file is released under the GPL.
*
* Device-mapper target to emulate smaller logical block
* size on backing devices exposing (natively) larger ones.
*
* E.g. 512 byte sector emulation on 4K native disks.
*/
#include "dm.h"
#include <linux/module.h>
#include <linux/workqueue.h>
#include <linux/dm-bufio.h>
#define DM_MSG_PREFIX "ebs"
static void ebs_dtr(struct dm_target *ti);
/* Emulated block size context. */
struct ebs_c {
struct dm_dev *dev; /* Underlying device to emulate block size on. */
struct dm_bufio_client *bufio; /* Use dm-bufio for read and read-modify-write processing. */
struct workqueue_struct *wq; /* Workqueue for ^ processing of bios. */
struct work_struct ws; /* Work item used for ^. */
struct bio_list bios_in; /* Worker bios input list. */
spinlock_t lock; /* Guard bios input list above. */
sector_t start; /* <start> table line argument, see ebs_ctr below. */
unsigned int e_bs; /* Emulated block size in sectors exposed to upper layer. */
unsigned int u_bs; /* Underlying block size in sectors retrieved from/set on lower layer device. */
unsigned char block_shift; /* bitshift sectors -> blocks used in dm-bufio API. */
bool u_bs_set:1; /* Flag to indicate underlying block size is set on table line. */
};
static inline sector_t __sector_to_block(struct ebs_c *ec, sector_t sector)
{
return sector >> ec->block_shift;
}
static inline sector_t __block_mod(sector_t sector, unsigned int bs)
{
return sector & (bs - 1);
}
/* Return number of blocks for a bio, accounting for misalignment of start and end sectors. */
static inline unsigned int __nr_blocks(struct ebs_c *ec, struct bio *bio)
{
sector_t end_sector = __block_mod(bio->bi_iter.bi_sector, ec->u_bs) + bio_sectors(bio);
return __sector_to_block(ec, end_sector) + (__block_mod(end_sector, ec->u_bs) ? 1 : 0);
}
static inline bool __ebs_check_bs(unsigned int bs)
{
return bs && is_power_of_2(bs);
}
/*
* READ/WRITE:
*
* copy blocks between bufio blocks and bio vector's (partial/overlapping) pages.
*/
static int __ebs_rw_bvec(struct ebs_c *ec, enum req_op op, struct bio_vec *bv,
struct bvec_iter *iter)
{
int r = 0;
unsigned char *ba, *pa;
unsigned int cur_len;
unsigned int bv_len = bv->bv_len;
unsigned int buf_off = to_bytes(__block_mod(iter->bi_sector, ec->u_bs));
sector_t block = __sector_to_block(ec, iter->bi_sector);
struct dm_buffer *b;
if (unlikely(!bv->bv_page || !bv_len))
return -EIO;
pa = bvec_virt(bv);
/* Handle overlapping page <-> blocks */
while (bv_len) {
cur_len = min(dm_bufio_get_block_size(ec->bufio) - buf_off, bv_len);
/* Avoid reading for writes in case bio vector's page overwrites block completely. */
if (op == REQ_OP_READ || buf_off || bv_len < dm_bufio_get_block_size(ec->bufio))
ba = dm_bufio_read(ec->bufio, block, &b);
else
ba = dm_bufio_new(ec->bufio, block, &b);
if (IS_ERR(ba)) {
/*
* Carry on with next buffer, if any, to issue all possible
* data but return error.
*/
r = PTR_ERR(ba);
} else {
/* Copy data to/from bio to buffer if read/new was successful above. */
ba += buf_off;
if (op == REQ_OP_READ) {
memcpy(pa, ba, cur_len);
flush_dcache_page(bv->bv_page);
} else {
flush_dcache_page(bv->bv_page);
memcpy(ba, pa, cur_len);
dm_bufio_mark_partial_buffer_dirty(b, buf_off, buf_off + cur_len);
}
dm_bufio_release(b);
}
pa += cur_len;
bv_len -= cur_len;
buf_off = 0;
block++;
}
return r;
}
/* READ/WRITE: iterate bio vector's copying between (partial) pages and bufio blocks. */
static int __ebs_rw_bio(struct ebs_c *ec, enum req_op op, struct bio *bio)
{
int r = 0, rr;
struct bio_vec bv;
struct bvec_iter iter;
bio_for_each_bvec(bv, bio, iter) {
rr = __ebs_rw_bvec(ec, op, &bv, &iter);
if (rr)
r = rr;
}
return r;
}
/*
* Discard bio's blocks, i.e. pass discards down.
*
* Avoid discarding partial blocks at beginning and end;
* return 0 in case no blocks can be discarded as a result.
*/
static int __ebs_discard_bio(struct ebs_c *ec, struct bio *bio)
{
sector_t block, blocks, sector = bio->bi_iter.bi_sector;
block = __sector_to_block(ec, sector);
blocks = __nr_blocks(ec, bio);
/*
* Partial first underlying block (__nr_blocks() may have
* resulted in one block).
*/
if (__block_mod(sector, ec->u_bs)) {
block++;
blocks--;
}
/* Partial last underlying block if any. */
if (blocks && __block_mod(bio_end_sector(bio), ec->u_bs))
blocks--;
return blocks ? dm_bufio_issue_discard(ec->bufio, block, blocks) : 0;
}
/* Release blocks them from the bufio cache. */
static void __ebs_forget_bio(struct ebs_c *ec, struct bio *bio)
{
sector_t blocks, sector = bio->bi_iter.bi_sector;
blocks = __nr_blocks(ec, bio);
dm_bufio_forget_buffers(ec->bufio, __sector_to_block(ec, sector), blocks);
}
/* Worker function to process incoming bios. */
static void __ebs_process_bios(struct work_struct *ws)
{
int r;
bool write = false;
sector_t block1, block2;
struct ebs_c *ec = container_of(ws, struct ebs_c, ws);
struct bio *bio;
struct bio_list bios;
bio_list_init(&bios);
spin_lock_irq(&ec->lock);
bios = ec->bios_in;
bio_list_init(&ec->bios_in);
spin_unlock_irq(&ec->lock);
/* Prefetch all read and any mis-aligned write buffers */
bio_list_for_each(bio, &bios) {
block1 = __sector_to_block(ec, bio->bi_iter.bi_sector);
if (bio_op(bio) == REQ_OP_READ)
dm_bufio_prefetch(ec->bufio, block1, __nr_blocks(ec, bio));
else if (bio_op(bio) == REQ_OP_WRITE && !(bio->bi_opf & REQ_PREFLUSH)) {
block2 = __sector_to_block(ec, bio_end_sector(bio));
if (__block_mod(bio->bi_iter.bi_sector, ec->u_bs))
dm_bufio_prefetch(ec->bufio, block1, 1);
if (__block_mod(bio_end_sector(bio), ec->u_bs) && block2 != block1)
dm_bufio_prefetch(ec->bufio, block2, 1);
}
}
bio_list_for_each(bio, &bios) {
r = -EIO;
if (bio_op(bio) == REQ_OP_READ)
r = __ebs_rw_bio(ec, REQ_OP_READ, bio);
else if (bio_op(bio) == REQ_OP_WRITE) {
write = true;
r = __ebs_rw_bio(ec, REQ_OP_WRITE, bio);
} else if (bio_op(bio) == REQ_OP_DISCARD) {
__ebs_forget_bio(ec, bio);
r = __ebs_discard_bio(ec, bio);
}
if (r < 0)
bio->bi_status = errno_to_blk_status(r);
}
/*
* We write dirty buffers after processing I/O on them
* but before we endio thus addressing REQ_FUA/REQ_SYNC.
*/
r = write ? dm_bufio_write_dirty_buffers(ec->bufio) : 0;
while ((bio = bio_list_pop(&bios))) {
/* Any other request is endioed. */
if (unlikely(r && bio_op(bio) == REQ_OP_WRITE))
bio_io_error(bio);
else
bio_endio(bio);
}
}
/*
* Construct an emulated block size mapping: <dev_path> <offset> <ebs> [<ubs>]
*
* <dev_path>: path of the underlying device
* <offset>: offset in 512 bytes sectors into <dev_path>
* <ebs>: emulated block size in units of 512 bytes exposed to the upper layer
* [<ubs>]: underlying block size in units of 512 bytes imposed on the lower layer;
* optional, if not supplied, retrieve logical block size from underlying device
*/
static int ebs_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
int r;
unsigned short tmp1;
unsigned long long tmp;
char dummy;
struct ebs_c *ec;
if (argc < 3 || argc > 4) {
ti->error = "Invalid argument count";
return -EINVAL;
}
ec = ti->private = kzalloc(sizeof(*ec), GFP_KERNEL);
if (!ec) {
ti->error = "Cannot allocate ebs context";
return -ENOMEM;
}
r = -EINVAL;
if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1 ||
tmp != (sector_t)tmp ||
(sector_t)tmp >= ti->len) {
ti->error = "Invalid device offset sector";
goto bad;
}
ec->start = tmp;
if (sscanf(argv[2], "%hu%c", &tmp1, &dummy) != 1 ||
!__ebs_check_bs(tmp1) ||
to_bytes(tmp1) > PAGE_SIZE) {
ti->error = "Invalid emulated block size";
goto bad;
}
ec->e_bs = tmp1;
if (argc > 3) {
if (sscanf(argv[3], "%hu%c", &tmp1, &dummy) != 1 || !__ebs_check_bs(tmp1)) {
ti->error = "Invalid underlying block size";
goto bad;
}
ec->u_bs = tmp1;
ec->u_bs_set = true;
} else
ec->u_bs_set = false;
r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &ec->dev);
if (r) {
ti->error = "Device lookup failed";
ec->dev = NULL;
goto bad;
}
r = -EINVAL;
if (!ec->u_bs_set) {
ec->u_bs = to_sector(bdev_logical_block_size(ec->dev->bdev));
if (!__ebs_check_bs(ec->u_bs)) {
ti->error = "Invalid retrieved underlying block size";
goto bad;
}
}
if (!ec->u_bs_set && ec->e_bs == ec->u_bs)
DMINFO("Emulation superfluous: emulated equal to underlying block size");
if (__block_mod(ec->start, ec->u_bs)) {
ti->error = "Device offset must be multiple of underlying block size";
goto bad;
}
ec->bufio = dm_bufio_client_create(ec->dev->bdev, to_bytes(ec->u_bs), 1,
0, NULL, NULL, 0);
if (IS_ERR(ec->bufio)) {
ti->error = "Cannot create dm bufio client";
r = PTR_ERR(ec->bufio);
ec->bufio = NULL;
goto bad;
}
ec->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM);
if (!ec->wq) {
ti->error = "Cannot create dm-" DM_MSG_PREFIX " workqueue";
r = -ENOMEM;
goto bad;
}
ec->block_shift = __ffs(ec->u_bs);
INIT_WORK(&ec->ws, &__ebs_process_bios);
bio_list_init(&ec->bios_in);
spin_lock_init(&ec->lock);
ti->num_flush_bios = 1;
ti->num_discard_bios = 1;
ti->num_secure_erase_bios = 0;
ti->num_write_zeroes_bios = 0;
return 0;
bad:
ebs_dtr(ti);
return r;
}
static void ebs_dtr(struct dm_target *ti)
{
struct ebs_c *ec = ti->private;
if (ec->wq)
destroy_workqueue(ec->wq);
if (ec->bufio)
dm_bufio_client_destroy(ec->bufio);
if (ec->dev)
dm_put_device(ti, ec->dev);
kfree(ec);
}
static int ebs_map(struct dm_target *ti, struct bio *bio)
{
struct ebs_c *ec = ti->private;
bio_set_dev(bio, ec->dev->bdev);
bio->bi_iter.bi_sector = ec->start + dm_target_offset(ti, bio->bi_iter.bi_sector);
if (unlikely(bio_op(bio) == REQ_OP_FLUSH))
return DM_MAPIO_REMAPPED;
/*
* Only queue for bufio processing in case of partial or overlapping buffers
* -or-
* emulation with ebs == ubs aiming for tests of dm-bufio overhead.
*/
if (likely(__block_mod(bio->bi_iter.bi_sector, ec->u_bs) ||
__block_mod(bio_end_sector(bio), ec->u_bs) ||
ec->e_bs == ec->u_bs)) {
spin_lock_irq(&ec->lock);
bio_list_add(&ec->bios_in, bio);
spin_unlock_irq(&ec->lock);
queue_work(ec->wq, &ec->ws);
return DM_MAPIO_SUBMITTED;
}
/* Forget any buffer content relative to this direct backing device I/O. */
__ebs_forget_bio(ec, bio);
return DM_MAPIO_REMAPPED;
}
static void ebs_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
struct ebs_c *ec = ti->private;
switch (type) {
case STATUSTYPE_INFO:
*result = '\0';
break;
case STATUSTYPE_TABLE:
snprintf(result, maxlen, ec->u_bs_set ? "%s %llu %u %u" : "%s %llu %u",
ec->dev->name, (unsigned long long) ec->start, ec->e_bs, ec->u_bs);
break;
case STATUSTYPE_IMA:
*result = '\0';
break;
}
}
static int ebs_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
{
struct ebs_c *ec = ti->private;
struct dm_dev *dev = ec->dev;
/*
* Only pass ioctls through if the device sizes match exactly.
*/
*bdev = dev->bdev;
return !!(ec->start || ti->len != bdev_nr_sectors(dev->bdev));
}
static void ebs_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
struct ebs_c *ec = ti->private;
limits->logical_block_size = to_bytes(ec->e_bs);
limits->physical_block_size = to_bytes(ec->u_bs);
limits->alignment_offset = limits->physical_block_size;
blk_limits_io_min(limits, limits->logical_block_size);
}
static int ebs_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct ebs_c *ec = ti->private;
return fn(ti, ec->dev, ec->start, ti->len, data);
}
static struct target_type ebs_target = {
.name = "ebs",
.version = {1, 0, 1},
.features = DM_TARGET_PASSES_INTEGRITY,
.module = THIS_MODULE,
.ctr = ebs_ctr,
.dtr = ebs_dtr,
.map = ebs_map,
.status = ebs_status,
.io_hints = ebs_io_hints,
.prepare_ioctl = ebs_prepare_ioctl,
.iterate_devices = ebs_iterate_devices,
};
module_dm(ebs);
MODULE_AUTHOR("Heinz Mauelshagen <[email protected]>");
MODULE_DESCRIPTION(DM_NAME " emulated block size target");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-ebs-target.c |
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2015, SUSE
*/
#include <linux/module.h>
#include <linux/kthread.h>
#include <linux/dlm.h>
#include <linux/sched.h>
#include <linux/raid/md_p.h>
#include "md.h"
#include "md-bitmap.h"
#include "md-cluster.h"
#define LVB_SIZE 64
#define NEW_DEV_TIMEOUT 5000
struct dlm_lock_resource {
dlm_lockspace_t *ls;
struct dlm_lksb lksb;
char *name; /* lock name. */
uint32_t flags; /* flags to pass to dlm_lock() */
wait_queue_head_t sync_locking; /* wait queue for synchronized locking */
bool sync_locking_done;
void (*bast)(void *arg, int mode); /* blocking AST function pointer*/
struct mddev *mddev; /* pointing back to mddev. */
int mode;
};
struct resync_info {
__le64 lo;
__le64 hi;
};
/* md_cluster_info flags */
#define MD_CLUSTER_WAITING_FOR_NEWDISK 1
#define MD_CLUSTER_SUSPEND_READ_BALANCING 2
#define MD_CLUSTER_BEGIN_JOIN_CLUSTER 3
/* Lock the send communication. This is done through
* bit manipulation as opposed to a mutex in order to
* accommodate lock and hold. See next comment.
*/
#define MD_CLUSTER_SEND_LOCK 4
/* If cluster operations (such as adding a disk) must lock the
* communication channel, so as to perform extra operations
* (update metadata) and no other operation is allowed on the
* MD. Token needs to be locked and held until the operation
* completes witha md_update_sb(), which would eventually release
* the lock.
*/
#define MD_CLUSTER_SEND_LOCKED_ALREADY 5
/* We should receive message after node joined cluster and
* set up all the related infos such as bitmap and personality */
#define MD_CLUSTER_ALREADY_IN_CLUSTER 6
#define MD_CLUSTER_PENDING_RECV_EVENT 7
#define MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD 8
struct md_cluster_info {
struct mddev *mddev; /* the md device which md_cluster_info belongs to */
/* dlm lock space and resources for clustered raid. */
dlm_lockspace_t *lockspace;
int slot_number;
struct completion completion;
struct mutex recv_mutex;
struct dlm_lock_resource *bitmap_lockres;
struct dlm_lock_resource **other_bitmap_lockres;
struct dlm_lock_resource *resync_lockres;
struct list_head suspend_list;
spinlock_t suspend_lock;
/* record the region which write should be suspended */
sector_t suspend_lo;
sector_t suspend_hi;
int suspend_from; /* the slot which broadcast suspend_lo/hi */
struct md_thread __rcu *recovery_thread;
unsigned long recovery_map;
/* communication loc resources */
struct dlm_lock_resource *ack_lockres;
struct dlm_lock_resource *message_lockres;
struct dlm_lock_resource *token_lockres;
struct dlm_lock_resource *no_new_dev_lockres;
struct md_thread __rcu *recv_thread;
struct completion newdisk_completion;
wait_queue_head_t wait;
unsigned long state;
/* record the region in RESYNCING message */
sector_t sync_low;
sector_t sync_hi;
};
enum msg_type {
METADATA_UPDATED = 0,
RESYNCING,
NEWDISK,
REMOVE,
RE_ADD,
BITMAP_NEEDS_SYNC,
CHANGE_CAPACITY,
BITMAP_RESIZE,
};
struct cluster_msg {
__le32 type;
__le32 slot;
/* TODO: Unionize this for smaller footprint */
__le64 low;
__le64 high;
char uuid[16];
__le32 raid_slot;
};
static void sync_ast(void *arg)
{
struct dlm_lock_resource *res;
res = arg;
res->sync_locking_done = true;
wake_up(&res->sync_locking);
}
static int dlm_lock_sync(struct dlm_lock_resource *res, int mode)
{
int ret = 0;
ret = dlm_lock(res->ls, mode, &res->lksb,
res->flags, res->name, strlen(res->name),
0, sync_ast, res, res->bast);
if (ret)
return ret;
wait_event(res->sync_locking, res->sync_locking_done);
res->sync_locking_done = false;
if (res->lksb.sb_status == 0)
res->mode = mode;
return res->lksb.sb_status;
}
static int dlm_unlock_sync(struct dlm_lock_resource *res)
{
return dlm_lock_sync(res, DLM_LOCK_NL);
}
/*
* An variation of dlm_lock_sync, which make lock request could
* be interrupted
*/
static int dlm_lock_sync_interruptible(struct dlm_lock_resource *res, int mode,
struct mddev *mddev)
{
int ret = 0;
ret = dlm_lock(res->ls, mode, &res->lksb,
res->flags, res->name, strlen(res->name),
0, sync_ast, res, res->bast);
if (ret)
return ret;
wait_event(res->sync_locking, res->sync_locking_done
|| kthread_should_stop()
|| test_bit(MD_CLOSING, &mddev->flags));
if (!res->sync_locking_done) {
/*
* the convert queue contains the lock request when request is
* interrupted, and sync_ast could still be run, so need to
* cancel the request and reset completion
*/
ret = dlm_unlock(res->ls, res->lksb.sb_lkid, DLM_LKF_CANCEL,
&res->lksb, res);
res->sync_locking_done = false;
if (unlikely(ret != 0))
pr_info("failed to cancel previous lock request "
"%s return %d\n", res->name, ret);
return -EPERM;
} else
res->sync_locking_done = false;
if (res->lksb.sb_status == 0)
res->mode = mode;
return res->lksb.sb_status;
}
static struct dlm_lock_resource *lockres_init(struct mddev *mddev,
char *name, void (*bastfn)(void *arg, int mode), int with_lvb)
{
struct dlm_lock_resource *res = NULL;
int ret, namelen;
struct md_cluster_info *cinfo = mddev->cluster_info;
res = kzalloc(sizeof(struct dlm_lock_resource), GFP_KERNEL);
if (!res)
return NULL;
init_waitqueue_head(&res->sync_locking);
res->sync_locking_done = false;
res->ls = cinfo->lockspace;
res->mddev = mddev;
res->mode = DLM_LOCK_IV;
namelen = strlen(name);
res->name = kzalloc(namelen + 1, GFP_KERNEL);
if (!res->name) {
pr_err("md-cluster: Unable to allocate resource name for resource %s\n", name);
goto out_err;
}
strscpy(res->name, name, namelen + 1);
if (with_lvb) {
res->lksb.sb_lvbptr = kzalloc(LVB_SIZE, GFP_KERNEL);
if (!res->lksb.sb_lvbptr) {
pr_err("md-cluster: Unable to allocate LVB for resource %s\n", name);
goto out_err;
}
res->flags = DLM_LKF_VALBLK;
}
if (bastfn)
res->bast = bastfn;
res->flags |= DLM_LKF_EXPEDITE;
ret = dlm_lock_sync(res, DLM_LOCK_NL);
if (ret) {
pr_err("md-cluster: Unable to lock NL on new lock resource %s\n", name);
goto out_err;
}
res->flags &= ~DLM_LKF_EXPEDITE;
res->flags |= DLM_LKF_CONVERT;
return res;
out_err:
kfree(res->lksb.sb_lvbptr);
kfree(res->name);
kfree(res);
return NULL;
}
static void lockres_free(struct dlm_lock_resource *res)
{
int ret = 0;
if (!res)
return;
/*
* use FORCEUNLOCK flag, so we can unlock even the lock is on the
* waiting or convert queue
*/
ret = dlm_unlock(res->ls, res->lksb.sb_lkid, DLM_LKF_FORCEUNLOCK,
&res->lksb, res);
if (unlikely(ret != 0))
pr_err("failed to unlock %s return %d\n", res->name, ret);
else
wait_event(res->sync_locking, res->sync_locking_done);
kfree(res->name);
kfree(res->lksb.sb_lvbptr);
kfree(res);
}
static void add_resync_info(struct dlm_lock_resource *lockres,
sector_t lo, sector_t hi)
{
struct resync_info *ri;
ri = (struct resync_info *)lockres->lksb.sb_lvbptr;
ri->lo = cpu_to_le64(lo);
ri->hi = cpu_to_le64(hi);
}
static int read_resync_info(struct mddev *mddev,
struct dlm_lock_resource *lockres)
{
struct resync_info ri;
struct md_cluster_info *cinfo = mddev->cluster_info;
int ret = 0;
dlm_lock_sync(lockres, DLM_LOCK_CR);
memcpy(&ri, lockres->lksb.sb_lvbptr, sizeof(struct resync_info));
if (le64_to_cpu(ri.hi) > 0) {
cinfo->suspend_hi = le64_to_cpu(ri.hi);
cinfo->suspend_lo = le64_to_cpu(ri.lo);
ret = 1;
}
dlm_unlock_sync(lockres);
return ret;
}
static void recover_bitmaps(struct md_thread *thread)
{
struct mddev *mddev = thread->mddev;
struct md_cluster_info *cinfo = mddev->cluster_info;
struct dlm_lock_resource *bm_lockres;
char str[64];
int slot, ret;
sector_t lo, hi;
while (cinfo->recovery_map) {
slot = fls64((u64)cinfo->recovery_map) - 1;
snprintf(str, 64, "bitmap%04d", slot);
bm_lockres = lockres_init(mddev, str, NULL, 1);
if (!bm_lockres) {
pr_err("md-cluster: Cannot initialize bitmaps\n");
goto clear_bit;
}
ret = dlm_lock_sync_interruptible(bm_lockres, DLM_LOCK_PW, mddev);
if (ret) {
pr_err("md-cluster: Could not DLM lock %s: %d\n",
str, ret);
goto clear_bit;
}
ret = md_bitmap_copy_from_slot(mddev, slot, &lo, &hi, true);
if (ret) {
pr_err("md-cluster: Could not copy data from bitmap %d\n", slot);
goto clear_bit;
}
/* Clear suspend_area associated with the bitmap */
spin_lock_irq(&cinfo->suspend_lock);
cinfo->suspend_hi = 0;
cinfo->suspend_lo = 0;
cinfo->suspend_from = -1;
spin_unlock_irq(&cinfo->suspend_lock);
/* Kick off a reshape if needed */
if (test_bit(MD_RESYNCING_REMOTE, &mddev->recovery) &&
test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
mddev->reshape_position != MaxSector)
md_wakeup_thread(mddev->sync_thread);
if (hi > 0) {
if (lo < mddev->recovery_cp)
mddev->recovery_cp = lo;
/* wake up thread to continue resync in case resync
* is not finished */
if (mddev->recovery_cp != MaxSector) {
/*
* clear the REMOTE flag since we will launch
* resync thread in current node.
*/
clear_bit(MD_RESYNCING_REMOTE,
&mddev->recovery);
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
}
}
clear_bit:
lockres_free(bm_lockres);
clear_bit(slot, &cinfo->recovery_map);
}
}
static void recover_prep(void *arg)
{
struct mddev *mddev = arg;
struct md_cluster_info *cinfo = mddev->cluster_info;
set_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state);
}
static void __recover_slot(struct mddev *mddev, int slot)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
set_bit(slot, &cinfo->recovery_map);
if (!cinfo->recovery_thread) {
rcu_assign_pointer(cinfo->recovery_thread,
md_register_thread(recover_bitmaps, mddev, "recover"));
if (!cinfo->recovery_thread) {
pr_warn("md-cluster: Could not create recovery thread\n");
return;
}
}
md_wakeup_thread(cinfo->recovery_thread);
}
static void recover_slot(void *arg, struct dlm_slot *slot)
{
struct mddev *mddev = arg;
struct md_cluster_info *cinfo = mddev->cluster_info;
pr_info("md-cluster: %s Node %d/%d down. My slot: %d. Initiating recovery.\n",
mddev->bitmap_info.cluster_name,
slot->nodeid, slot->slot,
cinfo->slot_number);
/* deduct one since dlm slot starts from one while the num of
* cluster-md begins with 0 */
__recover_slot(mddev, slot->slot - 1);
}
static void recover_done(void *arg, struct dlm_slot *slots,
int num_slots, int our_slot,
uint32_t generation)
{
struct mddev *mddev = arg;
struct md_cluster_info *cinfo = mddev->cluster_info;
cinfo->slot_number = our_slot;
/* completion is only need to be complete when node join cluster,
* it doesn't need to run during another node's failure */
if (test_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state)) {
complete(&cinfo->completion);
clear_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state);
}
clear_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state);
}
/* the ops is called when node join the cluster, and do lock recovery
* if node failure occurs */
static const struct dlm_lockspace_ops md_ls_ops = {
.recover_prep = recover_prep,
.recover_slot = recover_slot,
.recover_done = recover_done,
};
/*
* The BAST function for the ack lock resource
* This function wakes up the receive thread in
* order to receive and process the message.
*/
static void ack_bast(void *arg, int mode)
{
struct dlm_lock_resource *res = arg;
struct md_cluster_info *cinfo = res->mddev->cluster_info;
if (mode == DLM_LOCK_EX) {
if (test_bit(MD_CLUSTER_ALREADY_IN_CLUSTER, &cinfo->state))
md_wakeup_thread(cinfo->recv_thread);
else
set_bit(MD_CLUSTER_PENDING_RECV_EVENT, &cinfo->state);
}
}
static void remove_suspend_info(struct mddev *mddev, int slot)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
mddev->pers->quiesce(mddev, 1);
spin_lock_irq(&cinfo->suspend_lock);
cinfo->suspend_hi = 0;
cinfo->suspend_lo = 0;
spin_unlock_irq(&cinfo->suspend_lock);
mddev->pers->quiesce(mddev, 0);
}
static void process_suspend_info(struct mddev *mddev,
int slot, sector_t lo, sector_t hi)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
struct mdp_superblock_1 *sb = NULL;
struct md_rdev *rdev;
if (!hi) {
/*
* clear the REMOTE flag since resync or recovery is finished
* in remote node.
*/
clear_bit(MD_RESYNCING_REMOTE, &mddev->recovery);
remove_suspend_info(mddev, slot);
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
return;
}
rdev_for_each(rdev, mddev)
if (rdev->raid_disk > -1 && !test_bit(Faulty, &rdev->flags)) {
sb = page_address(rdev->sb_page);
break;
}
/*
* The bitmaps are not same for different nodes
* if RESYNCING is happening in one node, then
* the node which received the RESYNCING message
* probably will perform resync with the region
* [lo, hi] again, so we could reduce resync time
* a lot if we can ensure that the bitmaps among
* different nodes are match up well.
*
* sync_low/hi is used to record the region which
* arrived in the previous RESYNCING message,
*
* Call md_bitmap_sync_with_cluster to clear NEEDED_MASK
* and set RESYNC_MASK since resync thread is running
* in another node, so we don't need to do the resync
* again with the same section.
*
* Skip md_bitmap_sync_with_cluster in case reshape
* happening, because reshaping region is small and
* we don't want to trigger lots of WARN.
*/
if (sb && !(le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE))
md_bitmap_sync_with_cluster(mddev, cinfo->sync_low,
cinfo->sync_hi, lo, hi);
cinfo->sync_low = lo;
cinfo->sync_hi = hi;
mddev->pers->quiesce(mddev, 1);
spin_lock_irq(&cinfo->suspend_lock);
cinfo->suspend_from = slot;
cinfo->suspend_lo = lo;
cinfo->suspend_hi = hi;
spin_unlock_irq(&cinfo->suspend_lock);
mddev->pers->quiesce(mddev, 0);
}
static void process_add_new_disk(struct mddev *mddev, struct cluster_msg *cmsg)
{
char disk_uuid[64];
struct md_cluster_info *cinfo = mddev->cluster_info;
char event_name[] = "EVENT=ADD_DEVICE";
char raid_slot[16];
char *envp[] = {event_name, disk_uuid, raid_slot, NULL};
int len;
len = snprintf(disk_uuid, 64, "DEVICE_UUID=");
sprintf(disk_uuid + len, "%pU", cmsg->uuid);
snprintf(raid_slot, 16, "RAID_DISK=%d", le32_to_cpu(cmsg->raid_slot));
pr_info("%s:%d Sending kobject change with %s and %s\n", __func__, __LINE__, disk_uuid, raid_slot);
init_completion(&cinfo->newdisk_completion);
set_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state);
kobject_uevent_env(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE, envp);
wait_for_completion_timeout(&cinfo->newdisk_completion,
NEW_DEV_TIMEOUT);
clear_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state);
}
static void process_metadata_update(struct mddev *mddev, struct cluster_msg *msg)
{
int got_lock = 0;
struct md_thread *thread;
struct md_cluster_info *cinfo = mddev->cluster_info;
mddev->good_device_nr = le32_to_cpu(msg->raid_slot);
dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);
/* daemaon thread must exist */
thread = rcu_dereference_protected(mddev->thread, true);
wait_event(thread->wqueue,
(got_lock = mddev_trylock(mddev)) ||
test_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state));
md_reload_sb(mddev, mddev->good_device_nr);
if (got_lock)
mddev_unlock(mddev);
}
static void process_remove_disk(struct mddev *mddev, struct cluster_msg *msg)
{
struct md_rdev *rdev;
rcu_read_lock();
rdev = md_find_rdev_nr_rcu(mddev, le32_to_cpu(msg->raid_slot));
if (rdev) {
set_bit(ClusterRemove, &rdev->flags);
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
}
else
pr_warn("%s: %d Could not find disk(%d) to REMOVE\n",
__func__, __LINE__, le32_to_cpu(msg->raid_slot));
rcu_read_unlock();
}
static void process_readd_disk(struct mddev *mddev, struct cluster_msg *msg)
{
struct md_rdev *rdev;
rcu_read_lock();
rdev = md_find_rdev_nr_rcu(mddev, le32_to_cpu(msg->raid_slot));
if (rdev && test_bit(Faulty, &rdev->flags))
clear_bit(Faulty, &rdev->flags);
else
pr_warn("%s: %d Could not find disk(%d) which is faulty",
__func__, __LINE__, le32_to_cpu(msg->raid_slot));
rcu_read_unlock();
}
static int process_recvd_msg(struct mddev *mddev, struct cluster_msg *msg)
{
int ret = 0;
if (WARN(mddev->cluster_info->slot_number - 1 == le32_to_cpu(msg->slot),
"node %d received its own msg\n", le32_to_cpu(msg->slot)))
return -1;
switch (le32_to_cpu(msg->type)) {
case METADATA_UPDATED:
process_metadata_update(mddev, msg);
break;
case CHANGE_CAPACITY:
set_capacity_and_notify(mddev->gendisk, mddev->array_sectors);
break;
case RESYNCING:
set_bit(MD_RESYNCING_REMOTE, &mddev->recovery);
process_suspend_info(mddev, le32_to_cpu(msg->slot),
le64_to_cpu(msg->low),
le64_to_cpu(msg->high));
break;
case NEWDISK:
process_add_new_disk(mddev, msg);
break;
case REMOVE:
process_remove_disk(mddev, msg);
break;
case RE_ADD:
process_readd_disk(mddev, msg);
break;
case BITMAP_NEEDS_SYNC:
__recover_slot(mddev, le32_to_cpu(msg->slot));
break;
case BITMAP_RESIZE:
if (le64_to_cpu(msg->high) != mddev->pers->size(mddev, 0, 0))
ret = md_bitmap_resize(mddev->bitmap,
le64_to_cpu(msg->high), 0, 0);
break;
default:
ret = -1;
pr_warn("%s:%d Received unknown message from %d\n",
__func__, __LINE__, msg->slot);
}
return ret;
}
/*
* thread for receiving message
*/
static void recv_daemon(struct md_thread *thread)
{
struct md_cluster_info *cinfo = thread->mddev->cluster_info;
struct dlm_lock_resource *ack_lockres = cinfo->ack_lockres;
struct dlm_lock_resource *message_lockres = cinfo->message_lockres;
struct cluster_msg msg;
int ret;
mutex_lock(&cinfo->recv_mutex);
/*get CR on Message*/
if (dlm_lock_sync(message_lockres, DLM_LOCK_CR)) {
pr_err("md/raid1:failed to get CR on MESSAGE\n");
mutex_unlock(&cinfo->recv_mutex);
return;
}
/* read lvb and wake up thread to process this message_lockres */
memcpy(&msg, message_lockres->lksb.sb_lvbptr, sizeof(struct cluster_msg));
ret = process_recvd_msg(thread->mddev, &msg);
if (ret)
goto out;
/*release CR on ack_lockres*/
ret = dlm_unlock_sync(ack_lockres);
if (unlikely(ret != 0))
pr_info("unlock ack failed return %d\n", ret);
/*up-convert to PR on message_lockres*/
ret = dlm_lock_sync(message_lockres, DLM_LOCK_PR);
if (unlikely(ret != 0))
pr_info("lock PR on msg failed return %d\n", ret);
/*get CR on ack_lockres again*/
ret = dlm_lock_sync(ack_lockres, DLM_LOCK_CR);
if (unlikely(ret != 0))
pr_info("lock CR on ack failed return %d\n", ret);
out:
/*release CR on message_lockres*/
ret = dlm_unlock_sync(message_lockres);
if (unlikely(ret != 0))
pr_info("unlock msg failed return %d\n", ret);
mutex_unlock(&cinfo->recv_mutex);
}
/* lock_token()
* Takes the lock on the TOKEN lock resource so no other
* node can communicate while the operation is underway.
*/
static int lock_token(struct md_cluster_info *cinfo)
{
int error;
error = dlm_lock_sync(cinfo->token_lockres, DLM_LOCK_EX);
if (error) {
pr_err("md-cluster(%s:%d): failed to get EX on TOKEN (%d)\n",
__func__, __LINE__, error);
} else {
/* Lock the receive sequence */
mutex_lock(&cinfo->recv_mutex);
}
return error;
}
/* lock_comm()
* Sets the MD_CLUSTER_SEND_LOCK bit to lock the send channel.
*/
static int lock_comm(struct md_cluster_info *cinfo, bool mddev_locked)
{
int rv, set_bit = 0;
struct mddev *mddev = cinfo->mddev;
/*
* If resync thread run after raid1d thread, then process_metadata_update
* could not continue if raid1d held reconfig_mutex (and raid1d is blocked
* since another node already got EX on Token and waiting the EX of Ack),
* so let resync wake up thread in case flag is set.
*/
if (mddev_locked && !test_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
&cinfo->state)) {
rv = test_and_set_bit_lock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
&cinfo->state);
WARN_ON_ONCE(rv);
md_wakeup_thread(mddev->thread);
set_bit = 1;
}
wait_event(cinfo->wait,
!test_and_set_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state));
rv = lock_token(cinfo);
if (set_bit)
clear_bit_unlock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
return rv;
}
static void unlock_comm(struct md_cluster_info *cinfo)
{
WARN_ON(cinfo->token_lockres->mode != DLM_LOCK_EX);
mutex_unlock(&cinfo->recv_mutex);
dlm_unlock_sync(cinfo->token_lockres);
clear_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state);
wake_up(&cinfo->wait);
}
/* __sendmsg()
* This function performs the actual sending of the message. This function is
* usually called after performing the encompassing operation
* The function:
* 1. Grabs the message lockresource in EX mode
* 2. Copies the message to the message LVB
* 3. Downconverts message lockresource to CW
* 4. Upconverts ack lock resource from CR to EX. This forces the BAST on other nodes
* and the other nodes read the message. The thread will wait here until all other
* nodes have released ack lock resource.
* 5. Downconvert ack lockresource to CR
*/
static int __sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg)
{
int error;
int slot = cinfo->slot_number - 1;
cmsg->slot = cpu_to_le32(slot);
/*get EX on Message*/
error = dlm_lock_sync(cinfo->message_lockres, DLM_LOCK_EX);
if (error) {
pr_err("md-cluster: failed to get EX on MESSAGE (%d)\n", error);
goto failed_message;
}
memcpy(cinfo->message_lockres->lksb.sb_lvbptr, (void *)cmsg,
sizeof(struct cluster_msg));
/*down-convert EX to CW on Message*/
error = dlm_lock_sync(cinfo->message_lockres, DLM_LOCK_CW);
if (error) {
pr_err("md-cluster: failed to convert EX to CW on MESSAGE(%d)\n",
error);
goto failed_ack;
}
/*up-convert CR to EX on Ack*/
error = dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_EX);
if (error) {
pr_err("md-cluster: failed to convert CR to EX on ACK(%d)\n",
error);
goto failed_ack;
}
/*down-convert EX to CR on Ack*/
error = dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_CR);
if (error) {
pr_err("md-cluster: failed to convert EX to CR on ACK(%d)\n",
error);
goto failed_ack;
}
failed_ack:
error = dlm_unlock_sync(cinfo->message_lockres);
if (unlikely(error != 0)) {
pr_err("md-cluster: failed convert to NL on MESSAGE(%d)\n",
error);
/* in case the message can't be released due to some reason */
goto failed_ack;
}
failed_message:
return error;
}
static int sendmsg(struct md_cluster_info *cinfo, struct cluster_msg *cmsg,
bool mddev_locked)
{
int ret;
ret = lock_comm(cinfo, mddev_locked);
if (!ret) {
ret = __sendmsg(cinfo, cmsg);
unlock_comm(cinfo);
}
return ret;
}
static int gather_all_resync_info(struct mddev *mddev, int total_slots)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
int i, ret = 0;
struct dlm_lock_resource *bm_lockres;
char str[64];
sector_t lo, hi;
for (i = 0; i < total_slots; i++) {
memset(str, '\0', 64);
snprintf(str, 64, "bitmap%04d", i);
bm_lockres = lockres_init(mddev, str, NULL, 1);
if (!bm_lockres)
return -ENOMEM;
if (i == (cinfo->slot_number - 1)) {
lockres_free(bm_lockres);
continue;
}
bm_lockres->flags |= DLM_LKF_NOQUEUE;
ret = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
if (ret == -EAGAIN) {
if (read_resync_info(mddev, bm_lockres)) {
pr_info("%s:%d Resync[%llu..%llu] in progress on %d\n",
__func__, __LINE__,
(unsigned long long) cinfo->suspend_lo,
(unsigned long long) cinfo->suspend_hi,
i);
cinfo->suspend_from = i;
}
ret = 0;
lockres_free(bm_lockres);
continue;
}
if (ret) {
lockres_free(bm_lockres);
goto out;
}
/* Read the disk bitmap sb and check if it needs recovery */
ret = md_bitmap_copy_from_slot(mddev, i, &lo, &hi, false);
if (ret) {
pr_warn("md-cluster: Could not gather bitmaps from slot %d", i);
lockres_free(bm_lockres);
continue;
}
if ((hi > 0) && (lo < mddev->recovery_cp)) {
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
mddev->recovery_cp = lo;
md_check_recovery(mddev);
}
lockres_free(bm_lockres);
}
out:
return ret;
}
static int join(struct mddev *mddev, int nodes)
{
struct md_cluster_info *cinfo;
int ret, ops_rv;
char str[64];
cinfo = kzalloc(sizeof(struct md_cluster_info), GFP_KERNEL);
if (!cinfo)
return -ENOMEM;
INIT_LIST_HEAD(&cinfo->suspend_list);
spin_lock_init(&cinfo->suspend_lock);
init_completion(&cinfo->completion);
set_bit(MD_CLUSTER_BEGIN_JOIN_CLUSTER, &cinfo->state);
init_waitqueue_head(&cinfo->wait);
mutex_init(&cinfo->recv_mutex);
mddev->cluster_info = cinfo;
cinfo->mddev = mddev;
memset(str, 0, 64);
sprintf(str, "%pU", mddev->uuid);
ret = dlm_new_lockspace(str, mddev->bitmap_info.cluster_name,
0, LVB_SIZE, &md_ls_ops, mddev,
&ops_rv, &cinfo->lockspace);
if (ret)
goto err;
wait_for_completion(&cinfo->completion);
if (nodes < cinfo->slot_number) {
pr_err("md-cluster: Slot allotted(%d) is greater than available slots(%d).",
cinfo->slot_number, nodes);
ret = -ERANGE;
goto err;
}
/* Initiate the communication resources */
ret = -ENOMEM;
rcu_assign_pointer(cinfo->recv_thread,
md_register_thread(recv_daemon, mddev, "cluster_recv"));
if (!cinfo->recv_thread) {
pr_err("md-cluster: cannot allocate memory for recv_thread!\n");
goto err;
}
cinfo->message_lockres = lockres_init(mddev, "message", NULL, 1);
if (!cinfo->message_lockres)
goto err;
cinfo->token_lockres = lockres_init(mddev, "token", NULL, 0);
if (!cinfo->token_lockres)
goto err;
cinfo->no_new_dev_lockres = lockres_init(mddev, "no-new-dev", NULL, 0);
if (!cinfo->no_new_dev_lockres)
goto err;
ret = dlm_lock_sync(cinfo->token_lockres, DLM_LOCK_EX);
if (ret) {
ret = -EAGAIN;
pr_err("md-cluster: can't join cluster to avoid lock issue\n");
goto err;
}
cinfo->ack_lockres = lockres_init(mddev, "ack", ack_bast, 0);
if (!cinfo->ack_lockres) {
ret = -ENOMEM;
goto err;
}
/* get sync CR lock on ACK. */
if (dlm_lock_sync(cinfo->ack_lockres, DLM_LOCK_CR))
pr_err("md-cluster: failed to get a sync CR lock on ACK!(%d)\n",
ret);
dlm_unlock_sync(cinfo->token_lockres);
/* get sync CR lock on no-new-dev. */
if (dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR))
pr_err("md-cluster: failed to get a sync CR lock on no-new-dev!(%d)\n", ret);
pr_info("md-cluster: Joined cluster %s slot %d\n", str, cinfo->slot_number);
snprintf(str, 64, "bitmap%04d", cinfo->slot_number - 1);
cinfo->bitmap_lockres = lockres_init(mddev, str, NULL, 1);
if (!cinfo->bitmap_lockres) {
ret = -ENOMEM;
goto err;
}
if (dlm_lock_sync(cinfo->bitmap_lockres, DLM_LOCK_PW)) {
pr_err("Failed to get bitmap lock\n");
ret = -EINVAL;
goto err;
}
cinfo->resync_lockres = lockres_init(mddev, "resync", NULL, 0);
if (!cinfo->resync_lockres) {
ret = -ENOMEM;
goto err;
}
return 0;
err:
set_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
md_unregister_thread(mddev, &cinfo->recovery_thread);
md_unregister_thread(mddev, &cinfo->recv_thread);
lockres_free(cinfo->message_lockres);
lockres_free(cinfo->token_lockres);
lockres_free(cinfo->ack_lockres);
lockres_free(cinfo->no_new_dev_lockres);
lockres_free(cinfo->resync_lockres);
lockres_free(cinfo->bitmap_lockres);
if (cinfo->lockspace)
dlm_release_lockspace(cinfo->lockspace, 2);
mddev->cluster_info = NULL;
kfree(cinfo);
return ret;
}
static void load_bitmaps(struct mddev *mddev, int total_slots)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
/* load all the node's bitmap info for resync */
if (gather_all_resync_info(mddev, total_slots))
pr_err("md-cluster: failed to gather all resyn infos\n");
set_bit(MD_CLUSTER_ALREADY_IN_CLUSTER, &cinfo->state);
/* wake up recv thread in case something need to be handled */
if (test_and_clear_bit(MD_CLUSTER_PENDING_RECV_EVENT, &cinfo->state))
md_wakeup_thread(cinfo->recv_thread);
}
static void resync_bitmap(struct mddev *mddev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
struct cluster_msg cmsg = {0};
int err;
cmsg.type = cpu_to_le32(BITMAP_NEEDS_SYNC);
err = sendmsg(cinfo, &cmsg, 1);
if (err)
pr_err("%s:%d: failed to send BITMAP_NEEDS_SYNC message (%d)\n",
__func__, __LINE__, err);
}
static void unlock_all_bitmaps(struct mddev *mddev);
static int leave(struct mddev *mddev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
if (!cinfo)
return 0;
/*
* BITMAP_NEEDS_SYNC message should be sent when node
* is leaving the cluster with dirty bitmap, also we
* can only deliver it when dlm connection is available.
*
* Also, we should send BITMAP_NEEDS_SYNC message in
* case reshaping is interrupted.
*/
if ((cinfo->slot_number > 0 && mddev->recovery_cp != MaxSector) ||
(mddev->reshape_position != MaxSector &&
test_bit(MD_CLOSING, &mddev->flags)))
resync_bitmap(mddev);
set_bit(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
md_unregister_thread(mddev, &cinfo->recovery_thread);
md_unregister_thread(mddev, &cinfo->recv_thread);
lockres_free(cinfo->message_lockres);
lockres_free(cinfo->token_lockres);
lockres_free(cinfo->ack_lockres);
lockres_free(cinfo->no_new_dev_lockres);
lockres_free(cinfo->resync_lockres);
lockres_free(cinfo->bitmap_lockres);
unlock_all_bitmaps(mddev);
dlm_release_lockspace(cinfo->lockspace, 2);
kfree(cinfo);
return 0;
}
/* slot_number(): Returns the MD slot number to use
* DLM starts the slot numbers from 1, wheras cluster-md
* wants the number to be from zero, so we deduct one
*/
static int slot_number(struct mddev *mddev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
return cinfo->slot_number - 1;
}
/*
* Check if the communication is already locked, else lock the communication
* channel.
* If it is already locked, token is in EX mode, and hence lock_token()
* should not be called.
*/
static int metadata_update_start(struct mddev *mddev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
int ret;
/*
* metadata_update_start is always called with the protection of
* reconfig_mutex, so set WAITING_FOR_TOKEN here.
*/
ret = test_and_set_bit_lock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD,
&cinfo->state);
WARN_ON_ONCE(ret);
md_wakeup_thread(mddev->thread);
wait_event(cinfo->wait,
!test_and_set_bit(MD_CLUSTER_SEND_LOCK, &cinfo->state) ||
test_and_clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state));
/* If token is already locked, return 0 */
if (cinfo->token_lockres->mode == DLM_LOCK_EX) {
clear_bit_unlock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
return 0;
}
ret = lock_token(cinfo);
clear_bit_unlock(MD_CLUSTER_HOLDING_MUTEX_FOR_RECVD, &cinfo->state);
return ret;
}
static int metadata_update_finish(struct mddev *mddev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
struct cluster_msg cmsg;
struct md_rdev *rdev;
int ret = 0;
int raid_slot = -1;
memset(&cmsg, 0, sizeof(cmsg));
cmsg.type = cpu_to_le32(METADATA_UPDATED);
/* Pick up a good active device number to send.
*/
rdev_for_each(rdev, mddev)
if (rdev->raid_disk > -1 && !test_bit(Faulty, &rdev->flags)) {
raid_slot = rdev->desc_nr;
break;
}
if (raid_slot >= 0) {
cmsg.raid_slot = cpu_to_le32(raid_slot);
ret = __sendmsg(cinfo, &cmsg);
} else
pr_warn("md-cluster: No good device id found to send\n");
clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
unlock_comm(cinfo);
return ret;
}
static void metadata_update_cancel(struct mddev *mddev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
unlock_comm(cinfo);
}
static int update_bitmap_size(struct mddev *mddev, sector_t size)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
struct cluster_msg cmsg = {0};
int ret;
cmsg.type = cpu_to_le32(BITMAP_RESIZE);
cmsg.high = cpu_to_le64(size);
ret = sendmsg(cinfo, &cmsg, 0);
if (ret)
pr_err("%s:%d: failed to send BITMAP_RESIZE message (%d)\n",
__func__, __LINE__, ret);
return ret;
}
static int resize_bitmaps(struct mddev *mddev, sector_t newsize, sector_t oldsize)
{
struct bitmap_counts *counts;
char str[64];
struct dlm_lock_resource *bm_lockres;
struct bitmap *bitmap = mddev->bitmap;
unsigned long my_pages = bitmap->counts.pages;
int i, rv;
/*
* We need to ensure all the nodes can grow to a larger
* bitmap size before make the reshaping.
*/
rv = update_bitmap_size(mddev, newsize);
if (rv)
return rv;
for (i = 0; i < mddev->bitmap_info.nodes; i++) {
if (i == md_cluster_ops->slot_number(mddev))
continue;
bitmap = get_bitmap_from_slot(mddev, i);
if (IS_ERR(bitmap)) {
pr_err("can't get bitmap from slot %d\n", i);
bitmap = NULL;
goto out;
}
counts = &bitmap->counts;
/*
* If we can hold the bitmap lock of one node then
* the slot is not occupied, update the pages.
*/
snprintf(str, 64, "bitmap%04d", i);
bm_lockres = lockres_init(mddev, str, NULL, 1);
if (!bm_lockres) {
pr_err("Cannot initialize %s lock\n", str);
goto out;
}
bm_lockres->flags |= DLM_LKF_NOQUEUE;
rv = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
if (!rv)
counts->pages = my_pages;
lockres_free(bm_lockres);
if (my_pages != counts->pages)
/*
* Let's revert the bitmap size if one node
* can't resize bitmap
*/
goto out;
md_bitmap_free(bitmap);
}
return 0;
out:
md_bitmap_free(bitmap);
update_bitmap_size(mddev, oldsize);
return -1;
}
/*
* return 0 if all the bitmaps have the same sync_size
*/
static int cluster_check_sync_size(struct mddev *mddev)
{
int i, rv;
bitmap_super_t *sb;
unsigned long my_sync_size, sync_size = 0;
int node_num = mddev->bitmap_info.nodes;
int current_slot = md_cluster_ops->slot_number(mddev);
struct bitmap *bitmap = mddev->bitmap;
char str[64];
struct dlm_lock_resource *bm_lockres;
sb = kmap_atomic(bitmap->storage.sb_page);
my_sync_size = sb->sync_size;
kunmap_atomic(sb);
for (i = 0; i < node_num; i++) {
if (i == current_slot)
continue;
bitmap = get_bitmap_from_slot(mddev, i);
if (IS_ERR(bitmap)) {
pr_err("can't get bitmap from slot %d\n", i);
return -1;
}
/*
* If we can hold the bitmap lock of one node then
* the slot is not occupied, update the sb.
*/
snprintf(str, 64, "bitmap%04d", i);
bm_lockres = lockres_init(mddev, str, NULL, 1);
if (!bm_lockres) {
pr_err("md-cluster: Cannot initialize %s\n", str);
md_bitmap_free(bitmap);
return -1;
}
bm_lockres->flags |= DLM_LKF_NOQUEUE;
rv = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
if (!rv)
md_bitmap_update_sb(bitmap);
lockres_free(bm_lockres);
sb = kmap_atomic(bitmap->storage.sb_page);
if (sync_size == 0)
sync_size = sb->sync_size;
else if (sync_size != sb->sync_size) {
kunmap_atomic(sb);
md_bitmap_free(bitmap);
return -1;
}
kunmap_atomic(sb);
md_bitmap_free(bitmap);
}
return (my_sync_size == sync_size) ? 0 : -1;
}
/*
* Update the size for cluster raid is a little more complex, we perform it
* by the steps:
* 1. hold token lock and update superblock in initiator node.
* 2. send METADATA_UPDATED msg to other nodes.
* 3. The initiator node continues to check each bitmap's sync_size, if all
* bitmaps have the same value of sync_size, then we can set capacity and
* let other nodes to perform it. If one node can't update sync_size
* accordingly, we need to revert to previous value.
*/
static void update_size(struct mddev *mddev, sector_t old_dev_sectors)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
struct cluster_msg cmsg;
struct md_rdev *rdev;
int ret = 0;
int raid_slot = -1;
md_update_sb(mddev, 1);
if (lock_comm(cinfo, 1)) {
pr_err("%s: lock_comm failed\n", __func__);
return;
}
memset(&cmsg, 0, sizeof(cmsg));
cmsg.type = cpu_to_le32(METADATA_UPDATED);
rdev_for_each(rdev, mddev)
if (rdev->raid_disk >= 0 && !test_bit(Faulty, &rdev->flags)) {
raid_slot = rdev->desc_nr;
break;
}
if (raid_slot >= 0) {
cmsg.raid_slot = cpu_to_le32(raid_slot);
/*
* We can only change capiticy after all the nodes can do it,
* so need to wait after other nodes already received the msg
* and handled the change
*/
ret = __sendmsg(cinfo, &cmsg);
if (ret) {
pr_err("%s:%d: failed to send METADATA_UPDATED msg\n",
__func__, __LINE__);
unlock_comm(cinfo);
return;
}
} else {
pr_err("md-cluster: No good device id found to send\n");
unlock_comm(cinfo);
return;
}
/*
* check the sync_size from other node's bitmap, if sync_size
* have already updated in other nodes as expected, send an
* empty metadata msg to permit the change of capacity
*/
if (cluster_check_sync_size(mddev) == 0) {
memset(&cmsg, 0, sizeof(cmsg));
cmsg.type = cpu_to_le32(CHANGE_CAPACITY);
ret = __sendmsg(cinfo, &cmsg);
if (ret)
pr_err("%s:%d: failed to send CHANGE_CAPACITY msg\n",
__func__, __LINE__);
set_capacity_and_notify(mddev->gendisk, mddev->array_sectors);
} else {
/* revert to previous sectors */
ret = mddev->pers->resize(mddev, old_dev_sectors);
ret = __sendmsg(cinfo, &cmsg);
if (ret)
pr_err("%s:%d: failed to send METADATA_UPDATED msg\n",
__func__, __LINE__);
}
unlock_comm(cinfo);
}
static int resync_start(struct mddev *mddev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
return dlm_lock_sync_interruptible(cinfo->resync_lockres, DLM_LOCK_EX, mddev);
}
static void resync_info_get(struct mddev *mddev, sector_t *lo, sector_t *hi)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
spin_lock_irq(&cinfo->suspend_lock);
*lo = cinfo->suspend_lo;
*hi = cinfo->suspend_hi;
spin_unlock_irq(&cinfo->suspend_lock);
}
static int resync_info_update(struct mddev *mddev, sector_t lo, sector_t hi)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
struct resync_info ri;
struct cluster_msg cmsg = {0};
/* do not send zero again, if we have sent before */
if (hi == 0) {
memcpy(&ri, cinfo->bitmap_lockres->lksb.sb_lvbptr, sizeof(struct resync_info));
if (le64_to_cpu(ri.hi) == 0)
return 0;
}
add_resync_info(cinfo->bitmap_lockres, lo, hi);
/* Re-acquire the lock to refresh LVB */
dlm_lock_sync(cinfo->bitmap_lockres, DLM_LOCK_PW);
cmsg.type = cpu_to_le32(RESYNCING);
cmsg.low = cpu_to_le64(lo);
cmsg.high = cpu_to_le64(hi);
/*
* mddev_lock is held if resync_info_update is called from
* resync_finish (md_reap_sync_thread -> resync_finish)
*/
if (lo == 0 && hi == 0)
return sendmsg(cinfo, &cmsg, 1);
else
return sendmsg(cinfo, &cmsg, 0);
}
static int resync_finish(struct mddev *mddev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
int ret = 0;
clear_bit(MD_RESYNCING_REMOTE, &mddev->recovery);
/*
* If resync thread is interrupted so we can't say resync is finished,
* another node will launch resync thread to continue.
*/
if (!test_bit(MD_CLOSING, &mddev->flags))
ret = resync_info_update(mddev, 0, 0);
dlm_unlock_sync(cinfo->resync_lockres);
return ret;
}
static int area_resyncing(struct mddev *mddev, int direction,
sector_t lo, sector_t hi)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
int ret = 0;
if ((direction == READ) &&
test_bit(MD_CLUSTER_SUSPEND_READ_BALANCING, &cinfo->state))
return 1;
spin_lock_irq(&cinfo->suspend_lock);
if (hi > cinfo->suspend_lo && lo < cinfo->suspend_hi)
ret = 1;
spin_unlock_irq(&cinfo->suspend_lock);
return ret;
}
/* add_new_disk() - initiates a disk add
* However, if this fails before writing md_update_sb(),
* add_new_disk_cancel() must be called to release token lock
*/
static int add_new_disk(struct mddev *mddev, struct md_rdev *rdev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
struct cluster_msg cmsg;
int ret = 0;
struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
char *uuid = sb->device_uuid;
memset(&cmsg, 0, sizeof(cmsg));
cmsg.type = cpu_to_le32(NEWDISK);
memcpy(cmsg.uuid, uuid, 16);
cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
if (lock_comm(cinfo, 1))
return -EAGAIN;
ret = __sendmsg(cinfo, &cmsg);
if (ret) {
unlock_comm(cinfo);
return ret;
}
cinfo->no_new_dev_lockres->flags |= DLM_LKF_NOQUEUE;
ret = dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_EX);
cinfo->no_new_dev_lockres->flags &= ~DLM_LKF_NOQUEUE;
/* Some node does not "see" the device */
if (ret == -EAGAIN)
ret = -ENOENT;
if (ret)
unlock_comm(cinfo);
else {
dlm_lock_sync(cinfo->no_new_dev_lockres, DLM_LOCK_CR);
/* Since MD_CHANGE_DEVS will be set in add_bound_rdev which
* will run soon after add_new_disk, the below path will be
* invoked:
* md_wakeup_thread(mddev->thread)
* -> conf->thread (raid1d)
* -> md_check_recovery -> md_update_sb
* -> metadata_update_start/finish
* MD_CLUSTER_SEND_LOCKED_ALREADY will be cleared eventually.
*
* For other failure cases, metadata_update_cancel and
* add_new_disk_cancel also clear below bit as well.
* */
set_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
wake_up(&cinfo->wait);
}
return ret;
}
static void add_new_disk_cancel(struct mddev *mddev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
clear_bit(MD_CLUSTER_SEND_LOCKED_ALREADY, &cinfo->state);
unlock_comm(cinfo);
}
static int new_disk_ack(struct mddev *mddev, bool ack)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
if (!test_bit(MD_CLUSTER_WAITING_FOR_NEWDISK, &cinfo->state)) {
pr_warn("md-cluster(%s): Spurious cluster confirmation\n", mdname(mddev));
return -EINVAL;
}
if (ack)
dlm_unlock_sync(cinfo->no_new_dev_lockres);
complete(&cinfo->newdisk_completion);
return 0;
}
static int remove_disk(struct mddev *mddev, struct md_rdev *rdev)
{
struct cluster_msg cmsg = {0};
struct md_cluster_info *cinfo = mddev->cluster_info;
cmsg.type = cpu_to_le32(REMOVE);
cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
return sendmsg(cinfo, &cmsg, 1);
}
static int lock_all_bitmaps(struct mddev *mddev)
{
int slot, my_slot, ret, held = 1, i = 0;
char str[64];
struct md_cluster_info *cinfo = mddev->cluster_info;
cinfo->other_bitmap_lockres =
kcalloc(mddev->bitmap_info.nodes - 1,
sizeof(struct dlm_lock_resource *), GFP_KERNEL);
if (!cinfo->other_bitmap_lockres) {
pr_err("md: can't alloc mem for other bitmap locks\n");
return 0;
}
my_slot = slot_number(mddev);
for (slot = 0; slot < mddev->bitmap_info.nodes; slot++) {
if (slot == my_slot)
continue;
memset(str, '\0', 64);
snprintf(str, 64, "bitmap%04d", slot);
cinfo->other_bitmap_lockres[i] = lockres_init(mddev, str, NULL, 1);
if (!cinfo->other_bitmap_lockres[i])
return -ENOMEM;
cinfo->other_bitmap_lockres[i]->flags |= DLM_LKF_NOQUEUE;
ret = dlm_lock_sync(cinfo->other_bitmap_lockres[i], DLM_LOCK_PW);
if (ret)
held = -1;
i++;
}
return held;
}
static void unlock_all_bitmaps(struct mddev *mddev)
{
struct md_cluster_info *cinfo = mddev->cluster_info;
int i;
/* release other node's bitmap lock if they are existed */
if (cinfo->other_bitmap_lockres) {
for (i = 0; i < mddev->bitmap_info.nodes - 1; i++) {
if (cinfo->other_bitmap_lockres[i]) {
lockres_free(cinfo->other_bitmap_lockres[i]);
}
}
kfree(cinfo->other_bitmap_lockres);
cinfo->other_bitmap_lockres = NULL;
}
}
static int gather_bitmaps(struct md_rdev *rdev)
{
int sn, err;
sector_t lo, hi;
struct cluster_msg cmsg = {0};
struct mddev *mddev = rdev->mddev;
struct md_cluster_info *cinfo = mddev->cluster_info;
cmsg.type = cpu_to_le32(RE_ADD);
cmsg.raid_slot = cpu_to_le32(rdev->desc_nr);
err = sendmsg(cinfo, &cmsg, 1);
if (err)
goto out;
for (sn = 0; sn < mddev->bitmap_info.nodes; sn++) {
if (sn == (cinfo->slot_number - 1))
continue;
err = md_bitmap_copy_from_slot(mddev, sn, &lo, &hi, false);
if (err) {
pr_warn("md-cluster: Could not gather bitmaps from slot %d", sn);
goto out;
}
if ((hi > 0) && (lo < mddev->recovery_cp))
mddev->recovery_cp = lo;
}
out:
return err;
}
static struct md_cluster_operations cluster_ops = {
.join = join,
.leave = leave,
.slot_number = slot_number,
.resync_start = resync_start,
.resync_finish = resync_finish,
.resync_info_update = resync_info_update,
.resync_info_get = resync_info_get,
.metadata_update_start = metadata_update_start,
.metadata_update_finish = metadata_update_finish,
.metadata_update_cancel = metadata_update_cancel,
.area_resyncing = area_resyncing,
.add_new_disk = add_new_disk,
.add_new_disk_cancel = add_new_disk_cancel,
.new_disk_ack = new_disk_ack,
.remove_disk = remove_disk,
.load_bitmaps = load_bitmaps,
.gather_bitmaps = gather_bitmaps,
.resize_bitmaps = resize_bitmaps,
.lock_all_bitmaps = lock_all_bitmaps,
.unlock_all_bitmaps = unlock_all_bitmaps,
.update_size = update_size,
};
static int __init cluster_init(void)
{
pr_warn("md-cluster: support raid1 and raid10 (limited support)\n");
pr_info("Registering Cluster MD functions\n");
register_md_cluster_operations(&cluster_ops, THIS_MODULE);
return 0;
}
static void cluster_exit(void)
{
unregister_md_cluster_operations();
}
module_init(cluster_init);
module_exit(cluster_exit);
MODULE_AUTHOR("SUSE");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Clustering support for MD");
| linux-master | drivers/md/md-cluster.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Historical Service Time
*
* Keeps a time-weighted exponential moving average of the historical
* service time. Estimates future service time based on the historical
* service time and the number of outstanding requests.
*
* Marks paths stale if they have not finished within hst *
* num_paths. If a path is stale and unused, we will send a single
* request to probe in case the path has improved. This situation
* generally arises if the path is so much worse than others that it
* will never have the best estimated service time, or if the entire
* multipath device is unused. If a path is stale and in use, limit the
* number of requests it can receive with the assumption that the path
* has become degraded.
*
* To avoid repeatedly calculating exponents for time weighting, times
* are split into HST_WEIGHT_COUNT buckets each (1 >> HST_BUCKET_SHIFT)
* ns, and the weighting is pre-calculated.
*
*/
#include "dm.h"
#include "dm-path-selector.h"
#include <linux/blkdev.h>
#include <linux/slab.h>
#include <linux/module.h>
#define DM_MSG_PREFIX "multipath historical-service-time"
#define HST_MIN_IO 1
#define HST_VERSION "0.1.1"
#define HST_FIXED_SHIFT 10 /* 10 bits of decimal precision */
#define HST_FIXED_MAX (ULLONG_MAX >> HST_FIXED_SHIFT)
#define HST_FIXED_1 (1 << HST_FIXED_SHIFT)
#define HST_FIXED_95 972
#define HST_MAX_INFLIGHT HST_FIXED_1
#define HST_BUCKET_SHIFT 24 /* Buckets are ~ 16ms */
#define HST_WEIGHT_COUNT 64ULL
struct selector {
struct list_head valid_paths;
struct list_head failed_paths;
int valid_count;
spinlock_t lock;
unsigned int weights[HST_WEIGHT_COUNT];
unsigned int threshold_multiplier;
};
struct path_info {
struct list_head list;
struct dm_path *path;
unsigned int repeat_count;
spinlock_t lock;
u64 historical_service_time; /* Fixed point */
u64 stale_after;
u64 last_finish;
u64 outstanding;
};
/**
* fixed_power - compute: x^n, in O(log n) time
*
* @x: base of the power
* @frac_bits: fractional bits of @x
* @n: power to raise @x to.
*
* By exploiting the relation between the definition of the natural power
* function: x^n := x*x*...*x (x multiplied by itself for n times), and
* the binary encoding of numbers used by computers: n := \Sum n_i * 2^i,
* (where: n_i \elem {0, 1}, the binary vector representing n),
* we find: x^n := x^(\Sum n_i * 2^i) := \Prod x^(n_i * 2^i), which is
* of course trivially computable in O(log_2 n), the length of our binary
* vector.
*
* (see: kernel/sched/loadavg.c)
*/
static u64 fixed_power(u64 x, unsigned int frac_bits, unsigned int n)
{
unsigned long result = 1UL << frac_bits;
if (n) {
for (;;) {
if (n & 1) {
result *= x;
result += 1UL << (frac_bits - 1);
result >>= frac_bits;
}
n >>= 1;
if (!n)
break;
x *= x;
x += 1UL << (frac_bits - 1);
x >>= frac_bits;
}
}
return result;
}
/*
* Calculate the next value of an exponential moving average
* a_1 = a_0 * e + a * (1 - e)
*
* @last: [0, ULLONG_MAX >> HST_FIXED_SHIFT]
* @next: [0, ULLONG_MAX >> HST_FIXED_SHIFT]
* @weight: [0, HST_FIXED_1]
*
* Note:
* To account for multiple periods in the same calculation,
* a_n = a_0 * e^n + a * (1 - e^n),
* so call fixed_ema(last, next, pow(weight, N))
*/
static u64 fixed_ema(u64 last, u64 next, u64 weight)
{
last *= weight;
last += next * (HST_FIXED_1 - weight);
last += 1ULL << (HST_FIXED_SHIFT - 1);
return last >> HST_FIXED_SHIFT;
}
static struct selector *alloc_selector(void)
{
struct selector *s = kmalloc(sizeof(*s), GFP_KERNEL);
if (s) {
INIT_LIST_HEAD(&s->valid_paths);
INIT_LIST_HEAD(&s->failed_paths);
spin_lock_init(&s->lock);
s->valid_count = 0;
}
return s;
}
/*
* Get the weight for a given time span.
*/
static u64 hst_weight(struct path_selector *ps, u64 delta)
{
struct selector *s = ps->context;
int bucket = clamp(delta >> HST_BUCKET_SHIFT, 0ULL,
HST_WEIGHT_COUNT - 1);
return s->weights[bucket];
}
/*
* Set up the weights array.
*
* weights[len-1] = 0
* weights[n] = base ^ (n + 1)
*/
static void hst_set_weights(struct path_selector *ps, unsigned int base)
{
struct selector *s = ps->context;
int i;
if (base >= HST_FIXED_1)
return;
for (i = 0; i < HST_WEIGHT_COUNT - 1; i++)
s->weights[i] = fixed_power(base, HST_FIXED_SHIFT, i + 1);
s->weights[HST_WEIGHT_COUNT - 1] = 0;
}
static int hst_create(struct path_selector *ps, unsigned int argc, char **argv)
{
struct selector *s;
unsigned int base_weight = HST_FIXED_95;
unsigned int threshold_multiplier = 0;
char dummy;
/*
* Arguments: [<base_weight> [<threshold_multiplier>]]
* <base_weight>: Base weight for ema [0, 1024) 10-bit fixed point. A
* value of 0 will completely ignore any history.
* If not given, default (HST_FIXED_95) is used.
* <threshold_multiplier>: Minimum threshold multiplier for paths to
* be considered different. That is, a path is
* considered different iff (p1 > N * p2) where p1
* is the path with higher service time. A threshold
* of 1 or 0 has no effect. Defaults to 0.
*/
if (argc > 2)
return -EINVAL;
if (argc && (sscanf(argv[0], "%u%c", &base_weight, &dummy) != 1 ||
base_weight >= HST_FIXED_1)) {
return -EINVAL;
}
if (argc > 1 && (sscanf(argv[1], "%u%c",
&threshold_multiplier, &dummy) != 1)) {
return -EINVAL;
}
s = alloc_selector();
if (!s)
return -ENOMEM;
ps->context = s;
hst_set_weights(ps, base_weight);
s->threshold_multiplier = threshold_multiplier;
return 0;
}
static void free_paths(struct list_head *paths)
{
struct path_info *pi, *next;
list_for_each_entry_safe(pi, next, paths, list) {
list_del(&pi->list);
kfree(pi);
}
}
static void hst_destroy(struct path_selector *ps)
{
struct selector *s = ps->context;
free_paths(&s->valid_paths);
free_paths(&s->failed_paths);
kfree(s);
ps->context = NULL;
}
static int hst_status(struct path_selector *ps, struct dm_path *path,
status_type_t type, char *result, unsigned int maxlen)
{
unsigned int sz = 0;
struct path_info *pi;
if (!path) {
struct selector *s = ps->context;
DMEMIT("2 %u %u ", s->weights[0], s->threshold_multiplier);
} else {
pi = path->pscontext;
switch (type) {
case STATUSTYPE_INFO:
DMEMIT("%llu %llu %llu ", pi->historical_service_time,
pi->outstanding, pi->stale_after);
break;
case STATUSTYPE_TABLE:
DMEMIT("0 ");
break;
case STATUSTYPE_IMA:
*result = '\0';
break;
}
}
return sz;
}
static int hst_add_path(struct path_selector *ps, struct dm_path *path,
int argc, char **argv, char **error)
{
struct selector *s = ps->context;
struct path_info *pi;
unsigned int repeat_count = HST_MIN_IO;
char dummy;
unsigned long flags;
/*
* Arguments: [<repeat_count>]
* <repeat_count>: The number of I/Os before switching path.
* If not given, default (HST_MIN_IO) is used.
*/
if (argc > 1) {
*error = "historical-service-time ps: incorrect number of arguments";
return -EINVAL;
}
if (argc && (sscanf(argv[0], "%u%c", &repeat_count, &dummy) != 1)) {
*error = "historical-service-time ps: invalid repeat count";
return -EINVAL;
}
/* allocate the path */
pi = kmalloc(sizeof(*pi), GFP_KERNEL);
if (!pi) {
*error = "historical-service-time ps: Error allocating path context";
return -ENOMEM;
}
pi->path = path;
pi->repeat_count = repeat_count;
pi->historical_service_time = HST_FIXED_1;
spin_lock_init(&pi->lock);
pi->outstanding = 0;
pi->stale_after = 0;
pi->last_finish = 0;
path->pscontext = pi;
spin_lock_irqsave(&s->lock, flags);
list_add_tail(&pi->list, &s->valid_paths);
s->valid_count++;
spin_unlock_irqrestore(&s->lock, flags);
return 0;
}
static void hst_fail_path(struct path_selector *ps, struct dm_path *path)
{
struct selector *s = ps->context;
struct path_info *pi = path->pscontext;
unsigned long flags;
spin_lock_irqsave(&s->lock, flags);
list_move(&pi->list, &s->failed_paths);
s->valid_count--;
spin_unlock_irqrestore(&s->lock, flags);
}
static int hst_reinstate_path(struct path_selector *ps, struct dm_path *path)
{
struct selector *s = ps->context;
struct path_info *pi = path->pscontext;
unsigned long flags;
spin_lock_irqsave(&s->lock, flags);
list_move_tail(&pi->list, &s->valid_paths);
s->valid_count++;
spin_unlock_irqrestore(&s->lock, flags);
return 0;
}
static void hst_fill_compare(struct path_info *pi, u64 *hst,
u64 *out, u64 *stale)
{
unsigned long flags;
spin_lock_irqsave(&pi->lock, flags);
*hst = pi->historical_service_time;
*out = pi->outstanding;
*stale = pi->stale_after;
spin_unlock_irqrestore(&pi->lock, flags);
}
/*
* Compare the estimated service time of 2 paths, pi1 and pi2,
* for the incoming I/O.
*
* Returns:
* < 0 : pi1 is better
* 0 : no difference between pi1 and pi2
* > 0 : pi2 is better
*
*/
static long long hst_compare(struct path_info *pi1, struct path_info *pi2,
u64 time_now, struct path_selector *ps)
{
struct selector *s = ps->context;
u64 hst1, hst2;
long long out1, out2, stale1, stale2;
int pi2_better, over_threshold;
hst_fill_compare(pi1, &hst1, &out1, &stale1);
hst_fill_compare(pi2, &hst2, &out2, &stale2);
/* Check here if estimated latency for two paths are too similar.
* If this is the case, we skip extra calculation and just compare
* outstanding requests. In this case, any unloaded paths will
* be preferred.
*/
if (hst1 > hst2)
over_threshold = hst1 > (s->threshold_multiplier * hst2);
else
over_threshold = hst2 > (s->threshold_multiplier * hst1);
if (!over_threshold)
return out1 - out2;
/*
* If an unloaded path is stale, choose it. If both paths are unloaded,
* choose path that is the most stale.
* (If one path is loaded, choose the other)
*/
if ((!out1 && stale1 < time_now) || (!out2 && stale2 < time_now) ||
(!out1 && !out2))
return (!out2 * stale1) - (!out1 * stale2);
/* Compare estimated service time. If outstanding is the same, we
* don't need to multiply
*/
if (out1 == out2) {
pi2_better = hst1 > hst2;
} else {
/* Potential overflow with out >= 1024 */
if (unlikely(out1 >= HST_MAX_INFLIGHT ||
out2 >= HST_MAX_INFLIGHT)) {
/* If over 1023 in-flights, we may overflow if hst
* is at max. (With this shift we still overflow at
* 1048576 in-flights, which is high enough).
*/
hst1 >>= HST_FIXED_SHIFT;
hst2 >>= HST_FIXED_SHIFT;
}
pi2_better = (1 + out1) * hst1 > (1 + out2) * hst2;
}
/* In the case that the 'winner' is stale, limit to equal usage. */
if (pi2_better) {
if (stale2 < time_now)
return out1 - out2;
return 1;
}
if (stale1 < time_now)
return out1 - out2;
return -1;
}
static struct dm_path *hst_select_path(struct path_selector *ps,
size_t nr_bytes)
{
struct selector *s = ps->context;
struct path_info *pi = NULL, *best = NULL;
u64 time_now = ktime_get_ns();
struct dm_path *ret = NULL;
unsigned long flags;
spin_lock_irqsave(&s->lock, flags);
if (list_empty(&s->valid_paths))
goto out;
list_for_each_entry(pi, &s->valid_paths, list) {
if (!best || (hst_compare(pi, best, time_now, ps) < 0))
best = pi;
}
if (!best)
goto out;
/* Move last used path to end (least preferred in case of ties) */
list_move_tail(&best->list, &s->valid_paths);
ret = best->path;
out:
spin_unlock_irqrestore(&s->lock, flags);
return ret;
}
static int hst_start_io(struct path_selector *ps, struct dm_path *path,
size_t nr_bytes)
{
struct path_info *pi = path->pscontext;
unsigned long flags;
spin_lock_irqsave(&pi->lock, flags);
pi->outstanding++;
spin_unlock_irqrestore(&pi->lock, flags);
return 0;
}
static u64 path_service_time(struct path_info *pi, u64 start_time)
{
u64 now = ktime_get_ns();
/* if a previous disk request has finished after this IO was
* sent to the hardware, pretend the submission happened
* serially.
*/
if (time_after64(pi->last_finish, start_time))
start_time = pi->last_finish;
pi->last_finish = now;
if (time_before64(now, start_time))
return 0;
return now - start_time;
}
static int hst_end_io(struct path_selector *ps, struct dm_path *path,
size_t nr_bytes, u64 start_time)
{
struct path_info *pi = path->pscontext;
struct selector *s = ps->context;
unsigned long flags;
u64 st;
spin_lock_irqsave(&pi->lock, flags);
st = path_service_time(pi, start_time);
pi->outstanding--;
pi->historical_service_time =
fixed_ema(pi->historical_service_time,
min(st * HST_FIXED_1, HST_FIXED_MAX),
hst_weight(ps, st));
/*
* On request end, mark path as fresh. If a path hasn't
* finished any requests within the fresh period, the estimated
* service time is considered too optimistic and we limit the
* maximum requests on that path.
*/
pi->stale_after = pi->last_finish +
(s->valid_count * (pi->historical_service_time >> HST_FIXED_SHIFT));
spin_unlock_irqrestore(&pi->lock, flags);
return 0;
}
static struct path_selector_type hst_ps = {
.name = "historical-service-time",
.module = THIS_MODULE,
.features = DM_PS_USE_HR_TIMER,
.table_args = 1,
.info_args = 3,
.create = hst_create,
.destroy = hst_destroy,
.status = hst_status,
.add_path = hst_add_path,
.fail_path = hst_fail_path,
.reinstate_path = hst_reinstate_path,
.select_path = hst_select_path,
.start_io = hst_start_io,
.end_io = hst_end_io,
};
static int __init dm_hst_init(void)
{
int r = dm_register_path_selector(&hst_ps);
if (r < 0)
DMERR("register failed %d", r);
DMINFO("version " HST_VERSION " loaded");
return r;
}
static void __exit dm_hst_exit(void)
{
int r = dm_unregister_path_selector(&hst_ps);
if (r < 0)
DMERR("unregister failed %d", r);
}
module_init(dm_hst_init);
module_exit(dm_hst_exit);
MODULE_DESCRIPTION(DM_NAME " measured service time oriented path selector");
MODULE_AUTHOR("Khazhismel Kumykov <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-ps-historical-service-time.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2001-2002 Sistina Software (UK) Limited.
*
* This file is released under the GPL.
*/
#include <linux/blkdev.h>
#include <linux/device-mapper.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kdev_t.h>
#include <linux/list.h>
#include <linux/list_bl.h>
#include <linux/mempool.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/log2.h>
#include <linux/dm-kcopyd.h>
#include "dm.h"
#include "dm-exception-store.h"
#define DM_MSG_PREFIX "snapshots"
static const char dm_snapshot_merge_target_name[] = "snapshot-merge";
#define dm_target_is_snapshot_merge(ti) \
((ti)->type->name == dm_snapshot_merge_target_name)
/*
* The size of the mempool used to track chunks in use.
*/
#define MIN_IOS 256
#define DM_TRACKED_CHUNK_HASH_SIZE 16
#define DM_TRACKED_CHUNK_HASH(x) ((unsigned long)(x) & \
(DM_TRACKED_CHUNK_HASH_SIZE - 1))
struct dm_exception_table {
uint32_t hash_mask;
unsigned int hash_shift;
struct hlist_bl_head *table;
};
struct dm_snapshot {
struct rw_semaphore lock;
struct dm_dev *origin;
struct dm_dev *cow;
struct dm_target *ti;
/* List of snapshots per Origin */
struct list_head list;
/*
* You can't use a snapshot if this is 0 (e.g. if full).
* A snapshot-merge target never clears this.
*/
int valid;
/*
* The snapshot overflowed because of a write to the snapshot device.
* We don't have to invalidate the snapshot in this case, but we need
* to prevent further writes.
*/
int snapshot_overflowed;
/* Origin writes don't trigger exceptions until this is set */
int active;
atomic_t pending_exceptions_count;
spinlock_t pe_allocation_lock;
/* Protected by "pe_allocation_lock" */
sector_t exception_start_sequence;
/* Protected by kcopyd single-threaded callback */
sector_t exception_complete_sequence;
/*
* A list of pending exceptions that completed out of order.
* Protected by kcopyd single-threaded callback.
*/
struct rb_root out_of_order_tree;
mempool_t pending_pool;
struct dm_exception_table pending;
struct dm_exception_table complete;
/*
* pe_lock protects all pending_exception operations and access
* as well as the snapshot_bios list.
*/
spinlock_t pe_lock;
/* Chunks with outstanding reads */
spinlock_t tracked_chunk_lock;
struct hlist_head tracked_chunk_hash[DM_TRACKED_CHUNK_HASH_SIZE];
/* The on disk metadata handler */
struct dm_exception_store *store;
unsigned int in_progress;
struct wait_queue_head in_progress_wait;
struct dm_kcopyd_client *kcopyd_client;
/* Wait for events based on state_bits */
unsigned long state_bits;
/* Range of chunks currently being merged. */
chunk_t first_merging_chunk;
int num_merging_chunks;
/*
* The merge operation failed if this flag is set.
* Failure modes are handled as follows:
* - I/O error reading the header
* => don't load the target; abort.
* - Header does not have "valid" flag set
* => use the origin; forget about the snapshot.
* - I/O error when reading exceptions
* => don't load the target; abort.
* (We can't use the intermediate origin state.)
* - I/O error while merging
* => stop merging; set merge_failed; process I/O normally.
*/
bool merge_failed:1;
bool discard_zeroes_cow:1;
bool discard_passdown_origin:1;
/*
* Incoming bios that overlap with chunks being merged must wait
* for them to be committed.
*/
struct bio_list bios_queued_during_merge;
};
/*
* state_bits:
* RUNNING_MERGE - Merge operation is in progress.
* SHUTDOWN_MERGE - Set to signal that merge needs to be stopped;
* cleared afterwards.
*/
#define RUNNING_MERGE 0
#define SHUTDOWN_MERGE 1
/*
* Maximum number of chunks being copied on write.
*
* The value was decided experimentally as a trade-off between memory
* consumption, stalling the kernel's workqueues and maintaining a high enough
* throughput.
*/
#define DEFAULT_COW_THRESHOLD 2048
static unsigned int cow_threshold = DEFAULT_COW_THRESHOLD;
module_param_named(snapshot_cow_threshold, cow_threshold, uint, 0644);
MODULE_PARM_DESC(snapshot_cow_threshold, "Maximum number of chunks being copied on write");
DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(snapshot_copy_throttle,
"A percentage of time allocated for copy on write");
struct dm_dev *dm_snap_origin(struct dm_snapshot *s)
{
return s->origin;
}
EXPORT_SYMBOL(dm_snap_origin);
struct dm_dev *dm_snap_cow(struct dm_snapshot *s)
{
return s->cow;
}
EXPORT_SYMBOL(dm_snap_cow);
static sector_t chunk_to_sector(struct dm_exception_store *store,
chunk_t chunk)
{
return chunk << store->chunk_shift;
}
static int bdev_equal(struct block_device *lhs, struct block_device *rhs)
{
/*
* There is only ever one instance of a particular block
* device so we can compare pointers safely.
*/
return lhs == rhs;
}
struct dm_snap_pending_exception {
struct dm_exception e;
/*
* Origin buffers waiting for this to complete are held
* in a bio list
*/
struct bio_list origin_bios;
struct bio_list snapshot_bios;
/* Pointer back to snapshot context */
struct dm_snapshot *snap;
/*
* 1 indicates the exception has already been sent to
* kcopyd.
*/
int started;
/* There was copying error. */
int copy_error;
/* A sequence number, it is used for in-order completion. */
sector_t exception_sequence;
struct rb_node out_of_order_node;
/*
* For writing a complete chunk, bypassing the copy.
*/
struct bio *full_bio;
bio_end_io_t *full_bio_end_io;
};
/*
* Hash table mapping origin volumes to lists of snapshots and
* a lock to protect it
*/
static struct kmem_cache *exception_cache;
static struct kmem_cache *pending_cache;
struct dm_snap_tracked_chunk {
struct hlist_node node;
chunk_t chunk;
};
static void init_tracked_chunk(struct bio *bio)
{
struct dm_snap_tracked_chunk *c = dm_per_bio_data(bio, sizeof(struct dm_snap_tracked_chunk));
INIT_HLIST_NODE(&c->node);
}
static bool is_bio_tracked(struct bio *bio)
{
struct dm_snap_tracked_chunk *c = dm_per_bio_data(bio, sizeof(struct dm_snap_tracked_chunk));
return !hlist_unhashed(&c->node);
}
static void track_chunk(struct dm_snapshot *s, struct bio *bio, chunk_t chunk)
{
struct dm_snap_tracked_chunk *c = dm_per_bio_data(bio, sizeof(struct dm_snap_tracked_chunk));
c->chunk = chunk;
spin_lock_irq(&s->tracked_chunk_lock);
hlist_add_head(&c->node,
&s->tracked_chunk_hash[DM_TRACKED_CHUNK_HASH(chunk)]);
spin_unlock_irq(&s->tracked_chunk_lock);
}
static void stop_tracking_chunk(struct dm_snapshot *s, struct bio *bio)
{
struct dm_snap_tracked_chunk *c = dm_per_bio_data(bio, sizeof(struct dm_snap_tracked_chunk));
unsigned long flags;
spin_lock_irqsave(&s->tracked_chunk_lock, flags);
hlist_del(&c->node);
spin_unlock_irqrestore(&s->tracked_chunk_lock, flags);
}
static int __chunk_is_tracked(struct dm_snapshot *s, chunk_t chunk)
{
struct dm_snap_tracked_chunk *c;
int found = 0;
spin_lock_irq(&s->tracked_chunk_lock);
hlist_for_each_entry(c,
&s->tracked_chunk_hash[DM_TRACKED_CHUNK_HASH(chunk)], node) {
if (c->chunk == chunk) {
found = 1;
break;
}
}
spin_unlock_irq(&s->tracked_chunk_lock);
return found;
}
/*
* This conflicting I/O is extremely improbable in the caller,
* so fsleep(1000) is sufficient and there is no need for a wait queue.
*/
static void __check_for_conflicting_io(struct dm_snapshot *s, chunk_t chunk)
{
while (__chunk_is_tracked(s, chunk))
fsleep(1000);
}
/*
* One of these per registered origin, held in the snapshot_origins hash
*/
struct origin {
/* The origin device */
struct block_device *bdev;
struct list_head hash_list;
/* List of snapshots for this origin */
struct list_head snapshots;
};
/*
* This structure is allocated for each origin target
*/
struct dm_origin {
struct dm_dev *dev;
struct dm_target *ti;
unsigned int split_boundary;
struct list_head hash_list;
};
/*
* Size of the hash table for origin volumes. If we make this
* the size of the minors list then it should be nearly perfect
*/
#define ORIGIN_HASH_SIZE 256
#define ORIGIN_MASK 0xFF
static struct list_head *_origins;
static struct list_head *_dm_origins;
static struct rw_semaphore _origins_lock;
static DECLARE_WAIT_QUEUE_HEAD(_pending_exceptions_done);
static DEFINE_SPINLOCK(_pending_exceptions_done_spinlock);
static uint64_t _pending_exceptions_done_count;
static int init_origin_hash(void)
{
int i;
_origins = kmalloc_array(ORIGIN_HASH_SIZE, sizeof(struct list_head),
GFP_KERNEL);
if (!_origins) {
DMERR("unable to allocate memory for _origins");
return -ENOMEM;
}
for (i = 0; i < ORIGIN_HASH_SIZE; i++)
INIT_LIST_HEAD(_origins + i);
_dm_origins = kmalloc_array(ORIGIN_HASH_SIZE,
sizeof(struct list_head),
GFP_KERNEL);
if (!_dm_origins) {
DMERR("unable to allocate memory for _dm_origins");
kfree(_origins);
return -ENOMEM;
}
for (i = 0; i < ORIGIN_HASH_SIZE; i++)
INIT_LIST_HEAD(_dm_origins + i);
init_rwsem(&_origins_lock);
return 0;
}
static void exit_origin_hash(void)
{
kfree(_origins);
kfree(_dm_origins);
}
static unsigned int origin_hash(struct block_device *bdev)
{
return bdev->bd_dev & ORIGIN_MASK;
}
static struct origin *__lookup_origin(struct block_device *origin)
{
struct list_head *ol;
struct origin *o;
ol = &_origins[origin_hash(origin)];
list_for_each_entry(o, ol, hash_list)
if (bdev_equal(o->bdev, origin))
return o;
return NULL;
}
static void __insert_origin(struct origin *o)
{
struct list_head *sl = &_origins[origin_hash(o->bdev)];
list_add_tail(&o->hash_list, sl);
}
static struct dm_origin *__lookup_dm_origin(struct block_device *origin)
{
struct list_head *ol;
struct dm_origin *o;
ol = &_dm_origins[origin_hash(origin)];
list_for_each_entry(o, ol, hash_list)
if (bdev_equal(o->dev->bdev, origin))
return o;
return NULL;
}
static void __insert_dm_origin(struct dm_origin *o)
{
struct list_head *sl = &_dm_origins[origin_hash(o->dev->bdev)];
list_add_tail(&o->hash_list, sl);
}
static void __remove_dm_origin(struct dm_origin *o)
{
list_del(&o->hash_list);
}
/*
* _origins_lock must be held when calling this function.
* Returns number of snapshots registered using the supplied cow device, plus:
* snap_src - a snapshot suitable for use as a source of exception handover
* snap_dest - a snapshot capable of receiving exception handover.
* snap_merge - an existing snapshot-merge target linked to the same origin.
* There can be at most one snapshot-merge target. The parameter is optional.
*
* Possible return values and states of snap_src and snap_dest.
* 0: NULL, NULL - first new snapshot
* 1: snap_src, NULL - normal snapshot
* 2: snap_src, snap_dest - waiting for handover
* 2: snap_src, NULL - handed over, waiting for old to be deleted
* 1: NULL, snap_dest - source got destroyed without handover
*/
static int __find_snapshots_sharing_cow(struct dm_snapshot *snap,
struct dm_snapshot **snap_src,
struct dm_snapshot **snap_dest,
struct dm_snapshot **snap_merge)
{
struct dm_snapshot *s;
struct origin *o;
int count = 0;
int active;
o = __lookup_origin(snap->origin->bdev);
if (!o)
goto out;
list_for_each_entry(s, &o->snapshots, list) {
if (dm_target_is_snapshot_merge(s->ti) && snap_merge)
*snap_merge = s;
if (!bdev_equal(s->cow->bdev, snap->cow->bdev))
continue;
down_read(&s->lock);
active = s->active;
up_read(&s->lock);
if (active) {
if (snap_src)
*snap_src = s;
} else if (snap_dest)
*snap_dest = s;
count++;
}
out:
return count;
}
/*
* On success, returns 1 if this snapshot is a handover destination,
* otherwise returns 0.
*/
static int __validate_exception_handover(struct dm_snapshot *snap)
{
struct dm_snapshot *snap_src = NULL, *snap_dest = NULL;
struct dm_snapshot *snap_merge = NULL;
/* Does snapshot need exceptions handed over to it? */
if ((__find_snapshots_sharing_cow(snap, &snap_src, &snap_dest,
&snap_merge) == 2) ||
snap_dest) {
snap->ti->error = "Snapshot cow pairing for exception table handover failed";
return -EINVAL;
}
/*
* If no snap_src was found, snap cannot become a handover
* destination.
*/
if (!snap_src)
return 0;
/*
* Non-snapshot-merge handover?
*/
if (!dm_target_is_snapshot_merge(snap->ti))
return 1;
/*
* Do not allow more than one merging snapshot.
*/
if (snap_merge) {
snap->ti->error = "A snapshot is already merging.";
return -EINVAL;
}
if (!snap_src->store->type->prepare_merge ||
!snap_src->store->type->commit_merge) {
snap->ti->error = "Snapshot exception store does not support snapshot-merge.";
return -EINVAL;
}
return 1;
}
static void __insert_snapshot(struct origin *o, struct dm_snapshot *s)
{
struct dm_snapshot *l;
/* Sort the list according to chunk size, largest-first smallest-last */
list_for_each_entry(l, &o->snapshots, list)
if (l->store->chunk_size < s->store->chunk_size)
break;
list_add_tail(&s->list, &l->list);
}
/*
* Make a note of the snapshot and its origin so we can look it
* up when the origin has a write on it.
*
* Also validate snapshot exception store handovers.
* On success, returns 1 if this registration is a handover destination,
* otherwise returns 0.
*/
static int register_snapshot(struct dm_snapshot *snap)
{
struct origin *o, *new_o = NULL;
struct block_device *bdev = snap->origin->bdev;
int r = 0;
new_o = kmalloc(sizeof(*new_o), GFP_KERNEL);
if (!new_o)
return -ENOMEM;
down_write(&_origins_lock);
r = __validate_exception_handover(snap);
if (r < 0) {
kfree(new_o);
goto out;
}
o = __lookup_origin(bdev);
if (o)
kfree(new_o);
else {
/* New origin */
o = new_o;
/* Initialise the struct */
INIT_LIST_HEAD(&o->snapshots);
o->bdev = bdev;
__insert_origin(o);
}
__insert_snapshot(o, snap);
out:
up_write(&_origins_lock);
return r;
}
/*
* Move snapshot to correct place in list according to chunk size.
*/
static void reregister_snapshot(struct dm_snapshot *s)
{
struct block_device *bdev = s->origin->bdev;
down_write(&_origins_lock);
list_del(&s->list);
__insert_snapshot(__lookup_origin(bdev), s);
up_write(&_origins_lock);
}
static void unregister_snapshot(struct dm_snapshot *s)
{
struct origin *o;
down_write(&_origins_lock);
o = __lookup_origin(s->origin->bdev);
list_del(&s->list);
if (o && list_empty(&o->snapshots)) {
list_del(&o->hash_list);
kfree(o);
}
up_write(&_origins_lock);
}
/*
* Implementation of the exception hash tables.
* The lowest hash_shift bits of the chunk number are ignored, allowing
* some consecutive chunks to be grouped together.
*/
static uint32_t exception_hash(struct dm_exception_table *et, chunk_t chunk);
/* Lock to protect access to the completed and pending exception hash tables. */
struct dm_exception_table_lock {
struct hlist_bl_head *complete_slot;
struct hlist_bl_head *pending_slot;
};
static void dm_exception_table_lock_init(struct dm_snapshot *s, chunk_t chunk,
struct dm_exception_table_lock *lock)
{
struct dm_exception_table *complete = &s->complete;
struct dm_exception_table *pending = &s->pending;
lock->complete_slot = &complete->table[exception_hash(complete, chunk)];
lock->pending_slot = &pending->table[exception_hash(pending, chunk)];
}
static void dm_exception_table_lock(struct dm_exception_table_lock *lock)
{
hlist_bl_lock(lock->complete_slot);
hlist_bl_lock(lock->pending_slot);
}
static void dm_exception_table_unlock(struct dm_exception_table_lock *lock)
{
hlist_bl_unlock(lock->pending_slot);
hlist_bl_unlock(lock->complete_slot);
}
static int dm_exception_table_init(struct dm_exception_table *et,
uint32_t size, unsigned int hash_shift)
{
unsigned int i;
et->hash_shift = hash_shift;
et->hash_mask = size - 1;
et->table = kvmalloc_array(size, sizeof(struct hlist_bl_head),
GFP_KERNEL);
if (!et->table)
return -ENOMEM;
for (i = 0; i < size; i++)
INIT_HLIST_BL_HEAD(et->table + i);
return 0;
}
static void dm_exception_table_exit(struct dm_exception_table *et,
struct kmem_cache *mem)
{
struct hlist_bl_head *slot;
struct dm_exception *ex;
struct hlist_bl_node *pos, *n;
int i, size;
size = et->hash_mask + 1;
for (i = 0; i < size; i++) {
slot = et->table + i;
hlist_bl_for_each_entry_safe(ex, pos, n, slot, hash_list)
kmem_cache_free(mem, ex);
}
kvfree(et->table);
}
static uint32_t exception_hash(struct dm_exception_table *et, chunk_t chunk)
{
return (chunk >> et->hash_shift) & et->hash_mask;
}
static void dm_remove_exception(struct dm_exception *e)
{
hlist_bl_del(&e->hash_list);
}
/*
* Return the exception data for a sector, or NULL if not
* remapped.
*/
static struct dm_exception *dm_lookup_exception(struct dm_exception_table *et,
chunk_t chunk)
{
struct hlist_bl_head *slot;
struct hlist_bl_node *pos;
struct dm_exception *e;
slot = &et->table[exception_hash(et, chunk)];
hlist_bl_for_each_entry(e, pos, slot, hash_list)
if (chunk >= e->old_chunk &&
chunk <= e->old_chunk + dm_consecutive_chunk_count(e))
return e;
return NULL;
}
static struct dm_exception *alloc_completed_exception(gfp_t gfp)
{
struct dm_exception *e;
e = kmem_cache_alloc(exception_cache, gfp);
if (!e && gfp == GFP_NOIO)
e = kmem_cache_alloc(exception_cache, GFP_ATOMIC);
return e;
}
static void free_completed_exception(struct dm_exception *e)
{
kmem_cache_free(exception_cache, e);
}
static struct dm_snap_pending_exception *alloc_pending_exception(struct dm_snapshot *s)
{
struct dm_snap_pending_exception *pe = mempool_alloc(&s->pending_pool,
GFP_NOIO);
atomic_inc(&s->pending_exceptions_count);
pe->snap = s;
return pe;
}
static void free_pending_exception(struct dm_snap_pending_exception *pe)
{
struct dm_snapshot *s = pe->snap;
mempool_free(pe, &s->pending_pool);
smp_mb__before_atomic();
atomic_dec(&s->pending_exceptions_count);
}
static void dm_insert_exception(struct dm_exception_table *eh,
struct dm_exception *new_e)
{
struct hlist_bl_head *l;
struct hlist_bl_node *pos;
struct dm_exception *e = NULL;
l = &eh->table[exception_hash(eh, new_e->old_chunk)];
/* Add immediately if this table doesn't support consecutive chunks */
if (!eh->hash_shift)
goto out;
/* List is ordered by old_chunk */
hlist_bl_for_each_entry(e, pos, l, hash_list) {
/* Insert after an existing chunk? */
if (new_e->old_chunk == (e->old_chunk +
dm_consecutive_chunk_count(e) + 1) &&
new_e->new_chunk == (dm_chunk_number(e->new_chunk) +
dm_consecutive_chunk_count(e) + 1)) {
dm_consecutive_chunk_count_inc(e);
free_completed_exception(new_e);
return;
}
/* Insert before an existing chunk? */
if (new_e->old_chunk == (e->old_chunk - 1) &&
new_e->new_chunk == (dm_chunk_number(e->new_chunk) - 1)) {
dm_consecutive_chunk_count_inc(e);
e->old_chunk--;
e->new_chunk--;
free_completed_exception(new_e);
return;
}
if (new_e->old_chunk < e->old_chunk)
break;
}
out:
if (!e) {
/*
* Either the table doesn't support consecutive chunks or slot
* l is empty.
*/
hlist_bl_add_head(&new_e->hash_list, l);
} else if (new_e->old_chunk < e->old_chunk) {
/* Add before an existing exception */
hlist_bl_add_before(&new_e->hash_list, &e->hash_list);
} else {
/* Add to l's tail: e is the last exception in this slot */
hlist_bl_add_behind(&new_e->hash_list, &e->hash_list);
}
}
/*
* Callback used by the exception stores to load exceptions when
* initialising.
*/
static int dm_add_exception(void *context, chunk_t old, chunk_t new)
{
struct dm_exception_table_lock lock;
struct dm_snapshot *s = context;
struct dm_exception *e;
e = alloc_completed_exception(GFP_KERNEL);
if (!e)
return -ENOMEM;
e->old_chunk = old;
/* Consecutive_count is implicitly initialised to zero */
e->new_chunk = new;
/*
* Although there is no need to lock access to the exception tables
* here, if we don't then hlist_bl_add_head(), called by
* dm_insert_exception(), will complain about accessing the
* corresponding list without locking it first.
*/
dm_exception_table_lock_init(s, old, &lock);
dm_exception_table_lock(&lock);
dm_insert_exception(&s->complete, e);
dm_exception_table_unlock(&lock);
return 0;
}
/*
* Return a minimum chunk size of all snapshots that have the specified origin.
* Return zero if the origin has no snapshots.
*/
static uint32_t __minimum_chunk_size(struct origin *o)
{
struct dm_snapshot *snap;
unsigned int chunk_size = rounddown_pow_of_two(UINT_MAX);
if (o)
list_for_each_entry(snap, &o->snapshots, list)
chunk_size = min_not_zero(chunk_size,
snap->store->chunk_size);
return (uint32_t) chunk_size;
}
/*
* Hard coded magic.
*/
static int calc_max_buckets(void)
{
/* use a fixed size of 2MB */
unsigned long mem = 2 * 1024 * 1024;
mem /= sizeof(struct hlist_bl_head);
return mem;
}
/*
* Allocate room for a suitable hash table.
*/
static int init_hash_tables(struct dm_snapshot *s)
{
sector_t hash_size, cow_dev_size, max_buckets;
/*
* Calculate based on the size of the original volume or
* the COW volume...
*/
cow_dev_size = get_dev_size(s->cow->bdev);
max_buckets = calc_max_buckets();
hash_size = cow_dev_size >> s->store->chunk_shift;
hash_size = min(hash_size, max_buckets);
if (hash_size < 64)
hash_size = 64;
hash_size = rounddown_pow_of_two(hash_size);
if (dm_exception_table_init(&s->complete, hash_size,
DM_CHUNK_CONSECUTIVE_BITS))
return -ENOMEM;
/*
* Allocate hash table for in-flight exceptions
* Make this smaller than the real hash table
*/
hash_size >>= 3;
if (hash_size < 64)
hash_size = 64;
if (dm_exception_table_init(&s->pending, hash_size, 0)) {
dm_exception_table_exit(&s->complete, exception_cache);
return -ENOMEM;
}
return 0;
}
static void merge_shutdown(struct dm_snapshot *s)
{
clear_bit_unlock(RUNNING_MERGE, &s->state_bits);
smp_mb__after_atomic();
wake_up_bit(&s->state_bits, RUNNING_MERGE);
}
static struct bio *__release_queued_bios_after_merge(struct dm_snapshot *s)
{
s->first_merging_chunk = 0;
s->num_merging_chunks = 0;
return bio_list_get(&s->bios_queued_during_merge);
}
/*
* Remove one chunk from the index of completed exceptions.
*/
static int __remove_single_exception_chunk(struct dm_snapshot *s,
chunk_t old_chunk)
{
struct dm_exception *e;
e = dm_lookup_exception(&s->complete, old_chunk);
if (!e) {
DMERR("Corruption detected: exception for block %llu is on disk but not in memory",
(unsigned long long)old_chunk);
return -EINVAL;
}
/*
* If this is the only chunk using this exception, remove exception.
*/
if (!dm_consecutive_chunk_count(e)) {
dm_remove_exception(e);
free_completed_exception(e);
return 0;
}
/*
* The chunk may be either at the beginning or the end of a
* group of consecutive chunks - never in the middle. We are
* removing chunks in the opposite order to that in which they
* were added, so this should always be true.
* Decrement the consecutive chunk counter and adjust the
* starting point if necessary.
*/
if (old_chunk == e->old_chunk) {
e->old_chunk++;
e->new_chunk++;
} else if (old_chunk != e->old_chunk +
dm_consecutive_chunk_count(e)) {
DMERR("Attempt to merge block %llu from the middle of a chunk range [%llu - %llu]",
(unsigned long long)old_chunk,
(unsigned long long)e->old_chunk,
(unsigned long long)
e->old_chunk + dm_consecutive_chunk_count(e));
return -EINVAL;
}
dm_consecutive_chunk_count_dec(e);
return 0;
}
static void flush_bios(struct bio *bio);
static int remove_single_exception_chunk(struct dm_snapshot *s)
{
struct bio *b = NULL;
int r;
chunk_t old_chunk = s->first_merging_chunk + s->num_merging_chunks - 1;
down_write(&s->lock);
/*
* Process chunks (and associated exceptions) in reverse order
* so that dm_consecutive_chunk_count_dec() accounting works.
*/
do {
r = __remove_single_exception_chunk(s, old_chunk);
if (r)
goto out;
} while (old_chunk-- > s->first_merging_chunk);
b = __release_queued_bios_after_merge(s);
out:
up_write(&s->lock);
if (b)
flush_bios(b);
return r;
}
static int origin_write_extent(struct dm_snapshot *merging_snap,
sector_t sector, unsigned int chunk_size);
static void merge_callback(int read_err, unsigned long write_err,
void *context);
static uint64_t read_pending_exceptions_done_count(void)
{
uint64_t pending_exceptions_done;
spin_lock(&_pending_exceptions_done_spinlock);
pending_exceptions_done = _pending_exceptions_done_count;
spin_unlock(&_pending_exceptions_done_spinlock);
return pending_exceptions_done;
}
static void increment_pending_exceptions_done_count(void)
{
spin_lock(&_pending_exceptions_done_spinlock);
_pending_exceptions_done_count++;
spin_unlock(&_pending_exceptions_done_spinlock);
wake_up_all(&_pending_exceptions_done);
}
static void snapshot_merge_next_chunks(struct dm_snapshot *s)
{
int i, linear_chunks;
chunk_t old_chunk, new_chunk;
struct dm_io_region src, dest;
sector_t io_size;
uint64_t previous_count;
BUG_ON(!test_bit(RUNNING_MERGE, &s->state_bits));
if (unlikely(test_bit(SHUTDOWN_MERGE, &s->state_bits)))
goto shut;
/*
* valid flag never changes during merge, so no lock required.
*/
if (!s->valid) {
DMERR("Snapshot is invalid: can't merge");
goto shut;
}
linear_chunks = s->store->type->prepare_merge(s->store, &old_chunk,
&new_chunk);
if (linear_chunks <= 0) {
if (linear_chunks < 0) {
DMERR("Read error in exception store: shutting down merge");
down_write(&s->lock);
s->merge_failed = true;
up_write(&s->lock);
}
goto shut;
}
/* Adjust old_chunk and new_chunk to reflect start of linear region */
old_chunk = old_chunk + 1 - linear_chunks;
new_chunk = new_chunk + 1 - linear_chunks;
/*
* Use one (potentially large) I/O to copy all 'linear_chunks'
* from the exception store to the origin
*/
io_size = linear_chunks * s->store->chunk_size;
dest.bdev = s->origin->bdev;
dest.sector = chunk_to_sector(s->store, old_chunk);
dest.count = min(io_size, get_dev_size(dest.bdev) - dest.sector);
src.bdev = s->cow->bdev;
src.sector = chunk_to_sector(s->store, new_chunk);
src.count = dest.count;
/*
* Reallocate any exceptions needed in other snapshots then
* wait for the pending exceptions to complete.
* Each time any pending exception (globally on the system)
* completes we are woken and repeat the process to find out
* if we can proceed. While this may not seem a particularly
* efficient algorithm, it is not expected to have any
* significant impact on performance.
*/
previous_count = read_pending_exceptions_done_count();
while (origin_write_extent(s, dest.sector, io_size)) {
wait_event(_pending_exceptions_done,
(read_pending_exceptions_done_count() !=
previous_count));
/* Retry after the wait, until all exceptions are done. */
previous_count = read_pending_exceptions_done_count();
}
down_write(&s->lock);
s->first_merging_chunk = old_chunk;
s->num_merging_chunks = linear_chunks;
up_write(&s->lock);
/* Wait until writes to all 'linear_chunks' drain */
for (i = 0; i < linear_chunks; i++)
__check_for_conflicting_io(s, old_chunk + i);
dm_kcopyd_copy(s->kcopyd_client, &src, 1, &dest, 0, merge_callback, s);
return;
shut:
merge_shutdown(s);
}
static void error_bios(struct bio *bio);
static void merge_callback(int read_err, unsigned long write_err, void *context)
{
struct dm_snapshot *s = context;
struct bio *b = NULL;
if (read_err || write_err) {
if (read_err)
DMERR("Read error: shutting down merge.");
else
DMERR("Write error: shutting down merge.");
goto shut;
}
if (blkdev_issue_flush(s->origin->bdev) < 0) {
DMERR("Flush after merge failed: shutting down merge");
goto shut;
}
if (s->store->type->commit_merge(s->store,
s->num_merging_chunks) < 0) {
DMERR("Write error in exception store: shutting down merge");
goto shut;
}
if (remove_single_exception_chunk(s) < 0)
goto shut;
snapshot_merge_next_chunks(s);
return;
shut:
down_write(&s->lock);
s->merge_failed = true;
b = __release_queued_bios_after_merge(s);
up_write(&s->lock);
error_bios(b);
merge_shutdown(s);
}
static void start_merge(struct dm_snapshot *s)
{
if (!test_and_set_bit(RUNNING_MERGE, &s->state_bits))
snapshot_merge_next_chunks(s);
}
/*
* Stop the merging process and wait until it finishes.
*/
static void stop_merge(struct dm_snapshot *s)
{
set_bit(SHUTDOWN_MERGE, &s->state_bits);
wait_on_bit(&s->state_bits, RUNNING_MERGE, TASK_UNINTERRUPTIBLE);
clear_bit(SHUTDOWN_MERGE, &s->state_bits);
}
static int parse_snapshot_features(struct dm_arg_set *as, struct dm_snapshot *s,
struct dm_target *ti)
{
int r;
unsigned int argc;
const char *arg_name;
static const struct dm_arg _args[] = {
{0, 2, "Invalid number of feature arguments"},
};
/*
* No feature arguments supplied.
*/
if (!as->argc)
return 0;
r = dm_read_arg_group(_args, as, &argc, &ti->error);
if (r)
return -EINVAL;
while (argc && !r) {
arg_name = dm_shift_arg(as);
argc--;
if (!strcasecmp(arg_name, "discard_zeroes_cow"))
s->discard_zeroes_cow = true;
else if (!strcasecmp(arg_name, "discard_passdown_origin"))
s->discard_passdown_origin = true;
else {
ti->error = "Unrecognised feature requested";
r = -EINVAL;
break;
}
}
if (!s->discard_zeroes_cow && s->discard_passdown_origin) {
/*
* TODO: really these are disjoint.. but ti->num_discard_bios
* and dm_bio_get_target_bio_nr() require rigid constraints.
*/
ti->error = "discard_passdown_origin feature depends on discard_zeroes_cow";
r = -EINVAL;
}
return r;
}
/*
* Construct a snapshot mapping:
* <origin_dev> <COW-dev> <p|po|n> <chunk-size> [<# feature args> [<arg>]*]
*/
static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
struct dm_snapshot *s;
struct dm_arg_set as;
int i;
int r = -EINVAL;
char *origin_path, *cow_path;
unsigned int args_used, num_flush_bios = 1;
blk_mode_t origin_mode = BLK_OPEN_READ;
if (argc < 4) {
ti->error = "requires 4 or more arguments";
r = -EINVAL;
goto bad;
}
if (dm_target_is_snapshot_merge(ti)) {
num_flush_bios = 2;
origin_mode = BLK_OPEN_WRITE;
}
s = kzalloc(sizeof(*s), GFP_KERNEL);
if (!s) {
ti->error = "Cannot allocate private snapshot structure";
r = -ENOMEM;
goto bad;
}
as.argc = argc;
as.argv = argv;
dm_consume_args(&as, 4);
r = parse_snapshot_features(&as, s, ti);
if (r)
goto bad_features;
origin_path = argv[0];
argv++;
argc--;
r = dm_get_device(ti, origin_path, origin_mode, &s->origin);
if (r) {
ti->error = "Cannot get origin device";
goto bad_origin;
}
cow_path = argv[0];
argv++;
argc--;
r = dm_get_device(ti, cow_path, dm_table_get_mode(ti->table), &s->cow);
if (r) {
ti->error = "Cannot get COW device";
goto bad_cow;
}
if (s->cow->bdev && s->cow->bdev == s->origin->bdev) {
ti->error = "COW device cannot be the same as origin device";
r = -EINVAL;
goto bad_store;
}
r = dm_exception_store_create(ti, argc, argv, s, &args_used, &s->store);
if (r) {
ti->error = "Couldn't create exception store";
r = -EINVAL;
goto bad_store;
}
argv += args_used;
argc -= args_used;
s->ti = ti;
s->valid = 1;
s->snapshot_overflowed = 0;
s->active = 0;
atomic_set(&s->pending_exceptions_count, 0);
spin_lock_init(&s->pe_allocation_lock);
s->exception_start_sequence = 0;
s->exception_complete_sequence = 0;
s->out_of_order_tree = RB_ROOT;
init_rwsem(&s->lock);
INIT_LIST_HEAD(&s->list);
spin_lock_init(&s->pe_lock);
s->state_bits = 0;
s->merge_failed = false;
s->first_merging_chunk = 0;
s->num_merging_chunks = 0;
bio_list_init(&s->bios_queued_during_merge);
/* Allocate hash table for COW data */
if (init_hash_tables(s)) {
ti->error = "Unable to allocate hash table space";
r = -ENOMEM;
goto bad_hash_tables;
}
init_waitqueue_head(&s->in_progress_wait);
s->kcopyd_client = dm_kcopyd_client_create(&dm_kcopyd_throttle);
if (IS_ERR(s->kcopyd_client)) {
r = PTR_ERR(s->kcopyd_client);
ti->error = "Could not create kcopyd client";
goto bad_kcopyd;
}
r = mempool_init_slab_pool(&s->pending_pool, MIN_IOS, pending_cache);
if (r) {
ti->error = "Could not allocate mempool for pending exceptions";
goto bad_pending_pool;
}
for (i = 0; i < DM_TRACKED_CHUNK_HASH_SIZE; i++)
INIT_HLIST_HEAD(&s->tracked_chunk_hash[i]);
spin_lock_init(&s->tracked_chunk_lock);
ti->private = s;
ti->num_flush_bios = num_flush_bios;
if (s->discard_zeroes_cow)
ti->num_discard_bios = (s->discard_passdown_origin ? 2 : 1);
ti->per_io_data_size = sizeof(struct dm_snap_tracked_chunk);
/* Add snapshot to the list of snapshots for this origin */
/* Exceptions aren't triggered till snapshot_resume() is called */
r = register_snapshot(s);
if (r == -ENOMEM) {
ti->error = "Snapshot origin struct allocation failed";
goto bad_load_and_register;
} else if (r < 0) {
/* invalid handover, register_snapshot has set ti->error */
goto bad_load_and_register;
}
/*
* Metadata must only be loaded into one table at once, so skip this
* if metadata will be handed over during resume.
* Chunk size will be set during the handover - set it to zero to
* ensure it's ignored.
*/
if (r > 0) {
s->store->chunk_size = 0;
return 0;
}
r = s->store->type->read_metadata(s->store, dm_add_exception,
(void *)s);
if (r < 0) {
ti->error = "Failed to read snapshot metadata";
goto bad_read_metadata;
} else if (r > 0) {
s->valid = 0;
DMWARN("Snapshot is marked invalid.");
}
if (!s->store->chunk_size) {
ti->error = "Chunk size not set";
r = -EINVAL;
goto bad_read_metadata;
}
r = dm_set_target_max_io_len(ti, s->store->chunk_size);
if (r)
goto bad_read_metadata;
return 0;
bad_read_metadata:
unregister_snapshot(s);
bad_load_and_register:
mempool_exit(&s->pending_pool);
bad_pending_pool:
dm_kcopyd_client_destroy(s->kcopyd_client);
bad_kcopyd:
dm_exception_table_exit(&s->pending, pending_cache);
dm_exception_table_exit(&s->complete, exception_cache);
bad_hash_tables:
dm_exception_store_destroy(s->store);
bad_store:
dm_put_device(ti, s->cow);
bad_cow:
dm_put_device(ti, s->origin);
bad_origin:
bad_features:
kfree(s);
bad:
return r;
}
static void __free_exceptions(struct dm_snapshot *s)
{
dm_kcopyd_client_destroy(s->kcopyd_client);
s->kcopyd_client = NULL;
dm_exception_table_exit(&s->pending, pending_cache);
dm_exception_table_exit(&s->complete, exception_cache);
}
static void __handover_exceptions(struct dm_snapshot *snap_src,
struct dm_snapshot *snap_dest)
{
union {
struct dm_exception_table table_swap;
struct dm_exception_store *store_swap;
} u;
/*
* Swap all snapshot context information between the two instances.
*/
u.table_swap = snap_dest->complete;
snap_dest->complete = snap_src->complete;
snap_src->complete = u.table_swap;
u.store_swap = snap_dest->store;
snap_dest->store = snap_src->store;
snap_dest->store->userspace_supports_overflow = u.store_swap->userspace_supports_overflow;
snap_src->store = u.store_swap;
snap_dest->store->snap = snap_dest;
snap_src->store->snap = snap_src;
snap_dest->ti->max_io_len = snap_dest->store->chunk_size;
snap_dest->valid = snap_src->valid;
snap_dest->snapshot_overflowed = snap_src->snapshot_overflowed;
/*
* Set source invalid to ensure it receives no further I/O.
*/
snap_src->valid = 0;
}
static void snapshot_dtr(struct dm_target *ti)
{
#ifdef CONFIG_DM_DEBUG
int i;
#endif
struct dm_snapshot *s = ti->private;
struct dm_snapshot *snap_src = NULL, *snap_dest = NULL;
down_read(&_origins_lock);
/* Check whether exception handover must be cancelled */
(void) __find_snapshots_sharing_cow(s, &snap_src, &snap_dest, NULL);
if (snap_src && snap_dest && (s == snap_src)) {
down_write(&snap_dest->lock);
snap_dest->valid = 0;
up_write(&snap_dest->lock);
DMERR("Cancelling snapshot handover.");
}
up_read(&_origins_lock);
if (dm_target_is_snapshot_merge(ti))
stop_merge(s);
/* Prevent further origin writes from using this snapshot. */
/* After this returns there can be no new kcopyd jobs. */
unregister_snapshot(s);
while (atomic_read(&s->pending_exceptions_count))
fsleep(1000);
/*
* Ensure instructions in mempool_exit aren't reordered
* before atomic_read.
*/
smp_mb();
#ifdef CONFIG_DM_DEBUG
for (i = 0; i < DM_TRACKED_CHUNK_HASH_SIZE; i++)
BUG_ON(!hlist_empty(&s->tracked_chunk_hash[i]));
#endif
__free_exceptions(s);
mempool_exit(&s->pending_pool);
dm_exception_store_destroy(s->store);
dm_put_device(ti, s->cow);
dm_put_device(ti, s->origin);
WARN_ON(s->in_progress);
kfree(s);
}
static void account_start_copy(struct dm_snapshot *s)
{
spin_lock(&s->in_progress_wait.lock);
s->in_progress++;
spin_unlock(&s->in_progress_wait.lock);
}
static void account_end_copy(struct dm_snapshot *s)
{
spin_lock(&s->in_progress_wait.lock);
BUG_ON(!s->in_progress);
s->in_progress--;
if (likely(s->in_progress <= cow_threshold) &&
unlikely(waitqueue_active(&s->in_progress_wait)))
wake_up_locked(&s->in_progress_wait);
spin_unlock(&s->in_progress_wait.lock);
}
static bool wait_for_in_progress(struct dm_snapshot *s, bool unlock_origins)
{
if (unlikely(s->in_progress > cow_threshold)) {
spin_lock(&s->in_progress_wait.lock);
if (likely(s->in_progress > cow_threshold)) {
/*
* NOTE: this throttle doesn't account for whether
* the caller is servicing an IO that will trigger a COW
* so excess throttling may result for chunks not required
* to be COW'd. But if cow_threshold was reached, extra
* throttling is unlikely to negatively impact performance.
*/
DECLARE_WAITQUEUE(wait, current);
__add_wait_queue(&s->in_progress_wait, &wait);
__set_current_state(TASK_UNINTERRUPTIBLE);
spin_unlock(&s->in_progress_wait.lock);
if (unlock_origins)
up_read(&_origins_lock);
io_schedule();
remove_wait_queue(&s->in_progress_wait, &wait);
return false;
}
spin_unlock(&s->in_progress_wait.lock);
}
return true;
}
/*
* Flush a list of buffers.
*/
static void flush_bios(struct bio *bio)
{
struct bio *n;
while (bio) {
n = bio->bi_next;
bio->bi_next = NULL;
submit_bio_noacct(bio);
bio = n;
}
}
static int do_origin(struct dm_dev *origin, struct bio *bio, bool limit);
/*
* Flush a list of buffers.
*/
static void retry_origin_bios(struct dm_snapshot *s, struct bio *bio)
{
struct bio *n;
int r;
while (bio) {
n = bio->bi_next;
bio->bi_next = NULL;
r = do_origin(s->origin, bio, false);
if (r == DM_MAPIO_REMAPPED)
submit_bio_noacct(bio);
bio = n;
}
}
/*
* Error a list of buffers.
*/
static void error_bios(struct bio *bio)
{
struct bio *n;
while (bio) {
n = bio->bi_next;
bio->bi_next = NULL;
bio_io_error(bio);
bio = n;
}
}
static void __invalidate_snapshot(struct dm_snapshot *s, int err)
{
if (!s->valid)
return;
if (err == -EIO)
DMERR("Invalidating snapshot: Error reading/writing.");
else if (err == -ENOMEM)
DMERR("Invalidating snapshot: Unable to allocate exception.");
if (s->store->type->drop_snapshot)
s->store->type->drop_snapshot(s->store);
s->valid = 0;
dm_table_event(s->ti->table);
}
static void invalidate_snapshot(struct dm_snapshot *s, int err)
{
down_write(&s->lock);
__invalidate_snapshot(s, err);
up_write(&s->lock);
}
static void pending_complete(void *context, int success)
{
struct dm_snap_pending_exception *pe = context;
struct dm_exception *e;
struct dm_snapshot *s = pe->snap;
struct bio *origin_bios = NULL;
struct bio *snapshot_bios = NULL;
struct bio *full_bio = NULL;
struct dm_exception_table_lock lock;
int error = 0;
dm_exception_table_lock_init(s, pe->e.old_chunk, &lock);
if (!success) {
/* Read/write error - snapshot is unusable */
invalidate_snapshot(s, -EIO);
error = 1;
dm_exception_table_lock(&lock);
goto out;
}
e = alloc_completed_exception(GFP_NOIO);
if (!e) {
invalidate_snapshot(s, -ENOMEM);
error = 1;
dm_exception_table_lock(&lock);
goto out;
}
*e = pe->e;
down_read(&s->lock);
dm_exception_table_lock(&lock);
if (!s->valid) {
up_read(&s->lock);
free_completed_exception(e);
error = 1;
goto out;
}
/*
* Add a proper exception. After inserting the completed exception all
* subsequent snapshot reads to this chunk will be redirected to the
* COW device. This ensures that we do not starve. Moreover, as long
* as the pending exception exists, neither origin writes nor snapshot
* merging can overwrite the chunk in origin.
*/
dm_insert_exception(&s->complete, e);
up_read(&s->lock);
/* Wait for conflicting reads to drain */
if (__chunk_is_tracked(s, pe->e.old_chunk)) {
dm_exception_table_unlock(&lock);
__check_for_conflicting_io(s, pe->e.old_chunk);
dm_exception_table_lock(&lock);
}
out:
/* Remove the in-flight exception from the list */
dm_remove_exception(&pe->e);
dm_exception_table_unlock(&lock);
snapshot_bios = bio_list_get(&pe->snapshot_bios);
origin_bios = bio_list_get(&pe->origin_bios);
full_bio = pe->full_bio;
if (full_bio)
full_bio->bi_end_io = pe->full_bio_end_io;
increment_pending_exceptions_done_count();
/* Submit any pending write bios */
if (error) {
if (full_bio)
bio_io_error(full_bio);
error_bios(snapshot_bios);
} else {
if (full_bio)
bio_endio(full_bio);
flush_bios(snapshot_bios);
}
retry_origin_bios(s, origin_bios);
free_pending_exception(pe);
}
static void complete_exception(struct dm_snap_pending_exception *pe)
{
struct dm_snapshot *s = pe->snap;
/* Update the metadata if we are persistent */
s->store->type->commit_exception(s->store, &pe->e, !pe->copy_error,
pending_complete, pe);
}
/*
* Called when the copy I/O has finished. kcopyd actually runs
* this code so don't block.
*/
static void copy_callback(int read_err, unsigned long write_err, void *context)
{
struct dm_snap_pending_exception *pe = context;
struct dm_snapshot *s = pe->snap;
pe->copy_error = read_err || write_err;
if (pe->exception_sequence == s->exception_complete_sequence) {
struct rb_node *next;
s->exception_complete_sequence++;
complete_exception(pe);
next = rb_first(&s->out_of_order_tree);
while (next) {
pe = rb_entry(next, struct dm_snap_pending_exception,
out_of_order_node);
if (pe->exception_sequence != s->exception_complete_sequence)
break;
next = rb_next(next);
s->exception_complete_sequence++;
rb_erase(&pe->out_of_order_node, &s->out_of_order_tree);
complete_exception(pe);
cond_resched();
}
} else {
struct rb_node *parent = NULL;
struct rb_node **p = &s->out_of_order_tree.rb_node;
struct dm_snap_pending_exception *pe2;
while (*p) {
pe2 = rb_entry(*p, struct dm_snap_pending_exception, out_of_order_node);
parent = *p;
BUG_ON(pe->exception_sequence == pe2->exception_sequence);
if (pe->exception_sequence < pe2->exception_sequence)
p = &((*p)->rb_left);
else
p = &((*p)->rb_right);
}
rb_link_node(&pe->out_of_order_node, parent, p);
rb_insert_color(&pe->out_of_order_node, &s->out_of_order_tree);
}
account_end_copy(s);
}
/*
* Dispatches the copy operation to kcopyd.
*/
static void start_copy(struct dm_snap_pending_exception *pe)
{
struct dm_snapshot *s = pe->snap;
struct dm_io_region src, dest;
struct block_device *bdev = s->origin->bdev;
sector_t dev_size;
dev_size = get_dev_size(bdev);
src.bdev = bdev;
src.sector = chunk_to_sector(s->store, pe->e.old_chunk);
src.count = min((sector_t)s->store->chunk_size, dev_size - src.sector);
dest.bdev = s->cow->bdev;
dest.sector = chunk_to_sector(s->store, pe->e.new_chunk);
dest.count = src.count;
/* Hand over to kcopyd */
account_start_copy(s);
dm_kcopyd_copy(s->kcopyd_client, &src, 1, &dest, 0, copy_callback, pe);
}
static void full_bio_end_io(struct bio *bio)
{
void *callback_data = bio->bi_private;
dm_kcopyd_do_callback(callback_data, 0, bio->bi_status ? 1 : 0);
}
static void start_full_bio(struct dm_snap_pending_exception *pe,
struct bio *bio)
{
struct dm_snapshot *s = pe->snap;
void *callback_data;
pe->full_bio = bio;
pe->full_bio_end_io = bio->bi_end_io;
account_start_copy(s);
callback_data = dm_kcopyd_prepare_callback(s->kcopyd_client,
copy_callback, pe);
bio->bi_end_io = full_bio_end_io;
bio->bi_private = callback_data;
submit_bio_noacct(bio);
}
static struct dm_snap_pending_exception *
__lookup_pending_exception(struct dm_snapshot *s, chunk_t chunk)
{
struct dm_exception *e = dm_lookup_exception(&s->pending, chunk);
if (!e)
return NULL;
return container_of(e, struct dm_snap_pending_exception, e);
}
/*
* Inserts a pending exception into the pending table.
*
* NOTE: a write lock must be held on the chunk's pending exception table slot
* before calling this.
*/
static struct dm_snap_pending_exception *
__insert_pending_exception(struct dm_snapshot *s,
struct dm_snap_pending_exception *pe, chunk_t chunk)
{
pe->e.old_chunk = chunk;
bio_list_init(&pe->origin_bios);
bio_list_init(&pe->snapshot_bios);
pe->started = 0;
pe->full_bio = NULL;
spin_lock(&s->pe_allocation_lock);
if (s->store->type->prepare_exception(s->store, &pe->e)) {
spin_unlock(&s->pe_allocation_lock);
free_pending_exception(pe);
return NULL;
}
pe->exception_sequence = s->exception_start_sequence++;
spin_unlock(&s->pe_allocation_lock);
dm_insert_exception(&s->pending, &pe->e);
return pe;
}
/*
* Looks to see if this snapshot already has a pending exception
* for this chunk, otherwise it allocates a new one and inserts
* it into the pending table.
*
* NOTE: a write lock must be held on the chunk's pending exception table slot
* before calling this.
*/
static struct dm_snap_pending_exception *
__find_pending_exception(struct dm_snapshot *s,
struct dm_snap_pending_exception *pe, chunk_t chunk)
{
struct dm_snap_pending_exception *pe2;
pe2 = __lookup_pending_exception(s, chunk);
if (pe2) {
free_pending_exception(pe);
return pe2;
}
return __insert_pending_exception(s, pe, chunk);
}
static void remap_exception(struct dm_snapshot *s, struct dm_exception *e,
struct bio *bio, chunk_t chunk)
{
bio_set_dev(bio, s->cow->bdev);
bio->bi_iter.bi_sector =
chunk_to_sector(s->store, dm_chunk_number(e->new_chunk) +
(chunk - e->old_chunk)) +
(bio->bi_iter.bi_sector & s->store->chunk_mask);
}
static void zero_callback(int read_err, unsigned long write_err, void *context)
{
struct bio *bio = context;
struct dm_snapshot *s = bio->bi_private;
account_end_copy(s);
bio->bi_status = write_err ? BLK_STS_IOERR : 0;
bio_endio(bio);
}
static void zero_exception(struct dm_snapshot *s, struct dm_exception *e,
struct bio *bio, chunk_t chunk)
{
struct dm_io_region dest;
dest.bdev = s->cow->bdev;
dest.sector = bio->bi_iter.bi_sector;
dest.count = s->store->chunk_size;
account_start_copy(s);
WARN_ON_ONCE(bio->bi_private);
bio->bi_private = s;
dm_kcopyd_zero(s->kcopyd_client, 1, &dest, 0, zero_callback, bio);
}
static bool io_overlaps_chunk(struct dm_snapshot *s, struct bio *bio)
{
return bio->bi_iter.bi_size ==
(s->store->chunk_size << SECTOR_SHIFT);
}
static int snapshot_map(struct dm_target *ti, struct bio *bio)
{
struct dm_exception *e;
struct dm_snapshot *s = ti->private;
int r = DM_MAPIO_REMAPPED;
chunk_t chunk;
struct dm_snap_pending_exception *pe = NULL;
struct dm_exception_table_lock lock;
init_tracked_chunk(bio);
if (bio->bi_opf & REQ_PREFLUSH) {
bio_set_dev(bio, s->cow->bdev);
return DM_MAPIO_REMAPPED;
}
chunk = sector_to_chunk(s->store, bio->bi_iter.bi_sector);
dm_exception_table_lock_init(s, chunk, &lock);
/* Full snapshots are not usable */
/* To get here the table must be live so s->active is always set. */
if (!s->valid)
return DM_MAPIO_KILL;
if (bio_data_dir(bio) == WRITE) {
while (unlikely(!wait_for_in_progress(s, false)))
; /* wait_for_in_progress() has slept */
}
down_read(&s->lock);
dm_exception_table_lock(&lock);
if (!s->valid || (unlikely(s->snapshot_overflowed) &&
bio_data_dir(bio) == WRITE)) {
r = DM_MAPIO_KILL;
goto out_unlock;
}
if (unlikely(bio_op(bio) == REQ_OP_DISCARD)) {
if (s->discard_passdown_origin && dm_bio_get_target_bio_nr(bio)) {
/*
* passdown discard to origin (without triggering
* snapshot exceptions via do_origin; doing so would
* defeat the goal of freeing space in origin that is
* implied by the "discard_passdown_origin" feature)
*/
bio_set_dev(bio, s->origin->bdev);
track_chunk(s, bio, chunk);
goto out_unlock;
}
/* discard to snapshot (target_bio_nr == 0) zeroes exceptions */
}
/* If the block is already remapped - use that, else remap it */
e = dm_lookup_exception(&s->complete, chunk);
if (e) {
remap_exception(s, e, bio, chunk);
if (unlikely(bio_op(bio) == REQ_OP_DISCARD) &&
io_overlaps_chunk(s, bio)) {
dm_exception_table_unlock(&lock);
up_read(&s->lock);
zero_exception(s, e, bio, chunk);
r = DM_MAPIO_SUBMITTED; /* discard is not issued */
goto out;
}
goto out_unlock;
}
if (unlikely(bio_op(bio) == REQ_OP_DISCARD)) {
/*
* If no exception exists, complete discard immediately
* otherwise it'll trigger copy-out.
*/
bio_endio(bio);
r = DM_MAPIO_SUBMITTED;
goto out_unlock;
}
/*
* Write to snapshot - higher level takes care of RW/RO
* flags so we should only get this if we are
* writable.
*/
if (bio_data_dir(bio) == WRITE) {
pe = __lookup_pending_exception(s, chunk);
if (!pe) {
dm_exception_table_unlock(&lock);
pe = alloc_pending_exception(s);
dm_exception_table_lock(&lock);
e = dm_lookup_exception(&s->complete, chunk);
if (e) {
free_pending_exception(pe);
remap_exception(s, e, bio, chunk);
goto out_unlock;
}
pe = __find_pending_exception(s, pe, chunk);
if (!pe) {
dm_exception_table_unlock(&lock);
up_read(&s->lock);
down_write(&s->lock);
if (s->store->userspace_supports_overflow) {
if (s->valid && !s->snapshot_overflowed) {
s->snapshot_overflowed = 1;
DMERR("Snapshot overflowed: Unable to allocate exception.");
}
} else
__invalidate_snapshot(s, -ENOMEM);
up_write(&s->lock);
r = DM_MAPIO_KILL;
goto out;
}
}
remap_exception(s, &pe->e, bio, chunk);
r = DM_MAPIO_SUBMITTED;
if (!pe->started && io_overlaps_chunk(s, bio)) {
pe->started = 1;
dm_exception_table_unlock(&lock);
up_read(&s->lock);
start_full_bio(pe, bio);
goto out;
}
bio_list_add(&pe->snapshot_bios, bio);
if (!pe->started) {
/* this is protected by the exception table lock */
pe->started = 1;
dm_exception_table_unlock(&lock);
up_read(&s->lock);
start_copy(pe);
goto out;
}
} else {
bio_set_dev(bio, s->origin->bdev);
track_chunk(s, bio, chunk);
}
out_unlock:
dm_exception_table_unlock(&lock);
up_read(&s->lock);
out:
return r;
}
/*
* A snapshot-merge target behaves like a combination of a snapshot
* target and a snapshot-origin target. It only generates new
* exceptions in other snapshots and not in the one that is being
* merged.
*
* For each chunk, if there is an existing exception, it is used to
* redirect I/O to the cow device. Otherwise I/O is sent to the origin,
* which in turn might generate exceptions in other snapshots.
* If merging is currently taking place on the chunk in question, the
* I/O is deferred by adding it to s->bios_queued_during_merge.
*/
static int snapshot_merge_map(struct dm_target *ti, struct bio *bio)
{
struct dm_exception *e;
struct dm_snapshot *s = ti->private;
int r = DM_MAPIO_REMAPPED;
chunk_t chunk;
init_tracked_chunk(bio);
if (bio->bi_opf & REQ_PREFLUSH) {
if (!dm_bio_get_target_bio_nr(bio))
bio_set_dev(bio, s->origin->bdev);
else
bio_set_dev(bio, s->cow->bdev);
return DM_MAPIO_REMAPPED;
}
if (unlikely(bio_op(bio) == REQ_OP_DISCARD)) {
/* Once merging, discards no longer effect change */
bio_endio(bio);
return DM_MAPIO_SUBMITTED;
}
chunk = sector_to_chunk(s->store, bio->bi_iter.bi_sector);
down_write(&s->lock);
/* Full merging snapshots are redirected to the origin */
if (!s->valid)
goto redirect_to_origin;
/* If the block is already remapped - use that */
e = dm_lookup_exception(&s->complete, chunk);
if (e) {
/* Queue writes overlapping with chunks being merged */
if (bio_data_dir(bio) == WRITE &&
chunk >= s->first_merging_chunk &&
chunk < (s->first_merging_chunk +
s->num_merging_chunks)) {
bio_set_dev(bio, s->origin->bdev);
bio_list_add(&s->bios_queued_during_merge, bio);
r = DM_MAPIO_SUBMITTED;
goto out_unlock;
}
remap_exception(s, e, bio, chunk);
if (bio_data_dir(bio) == WRITE)
track_chunk(s, bio, chunk);
goto out_unlock;
}
redirect_to_origin:
bio_set_dev(bio, s->origin->bdev);
if (bio_data_dir(bio) == WRITE) {
up_write(&s->lock);
return do_origin(s->origin, bio, false);
}
out_unlock:
up_write(&s->lock);
return r;
}
static int snapshot_end_io(struct dm_target *ti, struct bio *bio,
blk_status_t *error)
{
struct dm_snapshot *s = ti->private;
if (is_bio_tracked(bio))
stop_tracking_chunk(s, bio);
return DM_ENDIO_DONE;
}
static void snapshot_merge_presuspend(struct dm_target *ti)
{
struct dm_snapshot *s = ti->private;
stop_merge(s);
}
static int snapshot_preresume(struct dm_target *ti)
{
int r = 0;
struct dm_snapshot *s = ti->private;
struct dm_snapshot *snap_src = NULL, *snap_dest = NULL;
down_read(&_origins_lock);
(void) __find_snapshots_sharing_cow(s, &snap_src, &snap_dest, NULL);
if (snap_src && snap_dest) {
down_read(&snap_src->lock);
if (s == snap_src) {
DMERR("Unable to resume snapshot source until handover completes.");
r = -EINVAL;
} else if (!dm_suspended(snap_src->ti)) {
DMERR("Unable to perform snapshot handover until source is suspended.");
r = -EINVAL;
}
up_read(&snap_src->lock);
}
up_read(&_origins_lock);
return r;
}
static void snapshot_resume(struct dm_target *ti)
{
struct dm_snapshot *s = ti->private;
struct dm_snapshot *snap_src = NULL, *snap_dest = NULL, *snap_merging = NULL;
struct dm_origin *o;
struct mapped_device *origin_md = NULL;
bool must_restart_merging = false;
down_read(&_origins_lock);
o = __lookup_dm_origin(s->origin->bdev);
if (o)
origin_md = dm_table_get_md(o->ti->table);
if (!origin_md) {
(void) __find_snapshots_sharing_cow(s, NULL, NULL, &snap_merging);
if (snap_merging)
origin_md = dm_table_get_md(snap_merging->ti->table);
}
if (origin_md == dm_table_get_md(ti->table))
origin_md = NULL;
if (origin_md) {
if (dm_hold(origin_md))
origin_md = NULL;
}
up_read(&_origins_lock);
if (origin_md) {
dm_internal_suspend_fast(origin_md);
if (snap_merging && test_bit(RUNNING_MERGE, &snap_merging->state_bits)) {
must_restart_merging = true;
stop_merge(snap_merging);
}
}
down_read(&_origins_lock);
(void) __find_snapshots_sharing_cow(s, &snap_src, &snap_dest, NULL);
if (snap_src && snap_dest) {
down_write(&snap_src->lock);
down_write_nested(&snap_dest->lock, SINGLE_DEPTH_NESTING);
__handover_exceptions(snap_src, snap_dest);
up_write(&snap_dest->lock);
up_write(&snap_src->lock);
}
up_read(&_origins_lock);
if (origin_md) {
if (must_restart_merging)
start_merge(snap_merging);
dm_internal_resume_fast(origin_md);
dm_put(origin_md);
}
/* Now we have correct chunk size, reregister */
reregister_snapshot(s);
down_write(&s->lock);
s->active = 1;
up_write(&s->lock);
}
static uint32_t get_origin_minimum_chunksize(struct block_device *bdev)
{
uint32_t min_chunksize;
down_read(&_origins_lock);
min_chunksize = __minimum_chunk_size(__lookup_origin(bdev));
up_read(&_origins_lock);
return min_chunksize;
}
static void snapshot_merge_resume(struct dm_target *ti)
{
struct dm_snapshot *s = ti->private;
/*
* Handover exceptions from existing snapshot.
*/
snapshot_resume(ti);
/*
* snapshot-merge acts as an origin, so set ti->max_io_len
*/
ti->max_io_len = get_origin_minimum_chunksize(s->origin->bdev);
start_merge(s);
}
static void snapshot_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
unsigned int sz = 0;
struct dm_snapshot *snap = ti->private;
unsigned int num_features;
switch (type) {
case STATUSTYPE_INFO:
down_write(&snap->lock);
if (!snap->valid)
DMEMIT("Invalid");
else if (snap->merge_failed)
DMEMIT("Merge failed");
else if (snap->snapshot_overflowed)
DMEMIT("Overflow");
else {
if (snap->store->type->usage) {
sector_t total_sectors, sectors_allocated,
metadata_sectors;
snap->store->type->usage(snap->store,
&total_sectors,
§ors_allocated,
&metadata_sectors);
DMEMIT("%llu/%llu %llu",
(unsigned long long)sectors_allocated,
(unsigned long long)total_sectors,
(unsigned long long)metadata_sectors);
} else
DMEMIT("Unknown");
}
up_write(&snap->lock);
break;
case STATUSTYPE_TABLE:
/*
* kdevname returns a static pointer so we need
* to make private copies if the output is to
* make sense.
*/
DMEMIT("%s %s", snap->origin->name, snap->cow->name);
sz += snap->store->type->status(snap->store, type, result + sz,
maxlen - sz);
num_features = snap->discard_zeroes_cow + snap->discard_passdown_origin;
if (num_features) {
DMEMIT(" %u", num_features);
if (snap->discard_zeroes_cow)
DMEMIT(" discard_zeroes_cow");
if (snap->discard_passdown_origin)
DMEMIT(" discard_passdown_origin");
}
break;
case STATUSTYPE_IMA:
DMEMIT_TARGET_NAME_VERSION(ti->type);
DMEMIT(",snap_origin_name=%s", snap->origin->name);
DMEMIT(",snap_cow_name=%s", snap->cow->name);
DMEMIT(",snap_valid=%c", snap->valid ? 'y' : 'n');
DMEMIT(",snap_merge_failed=%c", snap->merge_failed ? 'y' : 'n');
DMEMIT(",snapshot_overflowed=%c", snap->snapshot_overflowed ? 'y' : 'n');
DMEMIT(";");
break;
}
}
static int snapshot_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct dm_snapshot *snap = ti->private;
int r;
r = fn(ti, snap->origin, 0, ti->len, data);
if (!r)
r = fn(ti, snap->cow, 0, get_dev_size(snap->cow->bdev), data);
return r;
}
static void snapshot_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
struct dm_snapshot *snap = ti->private;
if (snap->discard_zeroes_cow) {
struct dm_snapshot *snap_src = NULL, *snap_dest = NULL;
down_read(&_origins_lock);
(void) __find_snapshots_sharing_cow(snap, &snap_src, &snap_dest, NULL);
if (snap_src && snap_dest)
snap = snap_src;
/* All discards are split on chunk_size boundary */
limits->discard_granularity = snap->store->chunk_size;
limits->max_discard_sectors = snap->store->chunk_size;
up_read(&_origins_lock);
}
}
/*
*---------------------------------------------------------------
* Origin methods
*---------------------------------------------------------------
*/
/*
* If no exceptions need creating, DM_MAPIO_REMAPPED is returned and any
* supplied bio was ignored. The caller may submit it immediately.
* (No remapping actually occurs as the origin is always a direct linear
* map.)
*
* If further exceptions are required, DM_MAPIO_SUBMITTED is returned
* and any supplied bio is added to a list to be submitted once all
* the necessary exceptions exist.
*/
static int __origin_write(struct list_head *snapshots, sector_t sector,
struct bio *bio)
{
int r = DM_MAPIO_REMAPPED;
struct dm_snapshot *snap;
struct dm_exception *e;
struct dm_snap_pending_exception *pe, *pe2;
struct dm_snap_pending_exception *pe_to_start_now = NULL;
struct dm_snap_pending_exception *pe_to_start_last = NULL;
struct dm_exception_table_lock lock;
chunk_t chunk;
/* Do all the snapshots on this origin */
list_for_each_entry(snap, snapshots, list) {
/*
* Don't make new exceptions in a merging snapshot
* because it has effectively been deleted
*/
if (dm_target_is_snapshot_merge(snap->ti))
continue;
/* Nothing to do if writing beyond end of snapshot */
if (sector >= dm_table_get_size(snap->ti->table))
continue;
/*
* Remember, different snapshots can have
* different chunk sizes.
*/
chunk = sector_to_chunk(snap->store, sector);
dm_exception_table_lock_init(snap, chunk, &lock);
down_read(&snap->lock);
dm_exception_table_lock(&lock);
/* Only deal with valid and active snapshots */
if (!snap->valid || !snap->active)
goto next_snapshot;
pe = __lookup_pending_exception(snap, chunk);
if (!pe) {
/*
* Check exception table to see if block is already
* remapped in this snapshot and trigger an exception
* if not.
*/
e = dm_lookup_exception(&snap->complete, chunk);
if (e)
goto next_snapshot;
dm_exception_table_unlock(&lock);
pe = alloc_pending_exception(snap);
dm_exception_table_lock(&lock);
pe2 = __lookup_pending_exception(snap, chunk);
if (!pe2) {
e = dm_lookup_exception(&snap->complete, chunk);
if (e) {
free_pending_exception(pe);
goto next_snapshot;
}
pe = __insert_pending_exception(snap, pe, chunk);
if (!pe) {
dm_exception_table_unlock(&lock);
up_read(&snap->lock);
invalidate_snapshot(snap, -ENOMEM);
continue;
}
} else {
free_pending_exception(pe);
pe = pe2;
}
}
r = DM_MAPIO_SUBMITTED;
/*
* If an origin bio was supplied, queue it to wait for the
* completion of this exception, and start this one last,
* at the end of the function.
*/
if (bio) {
bio_list_add(&pe->origin_bios, bio);
bio = NULL;
if (!pe->started) {
pe->started = 1;
pe_to_start_last = pe;
}
}
if (!pe->started) {
pe->started = 1;
pe_to_start_now = pe;
}
next_snapshot:
dm_exception_table_unlock(&lock);
up_read(&snap->lock);
if (pe_to_start_now) {
start_copy(pe_to_start_now);
pe_to_start_now = NULL;
}
}
/*
* Submit the exception against which the bio is queued last,
* to give the other exceptions a head start.
*/
if (pe_to_start_last)
start_copy(pe_to_start_last);
return r;
}
/*
* Called on a write from the origin driver.
*/
static int do_origin(struct dm_dev *origin, struct bio *bio, bool limit)
{
struct origin *o;
int r = DM_MAPIO_REMAPPED;
again:
down_read(&_origins_lock);
o = __lookup_origin(origin->bdev);
if (o) {
if (limit) {
struct dm_snapshot *s;
list_for_each_entry(s, &o->snapshots, list)
if (unlikely(!wait_for_in_progress(s, true)))
goto again;
}
r = __origin_write(&o->snapshots, bio->bi_iter.bi_sector, bio);
}
up_read(&_origins_lock);
return r;
}
/*
* Trigger exceptions in all non-merging snapshots.
*
* The chunk size of the merging snapshot may be larger than the chunk
* size of some other snapshot so we may need to reallocate multiple
* chunks in other snapshots.
*
* We scan all the overlapping exceptions in the other snapshots.
* Returns 1 if anything was reallocated and must be waited for,
* otherwise returns 0.
*
* size must be a multiple of merging_snap's chunk_size.
*/
static int origin_write_extent(struct dm_snapshot *merging_snap,
sector_t sector, unsigned int size)
{
int must_wait = 0;
sector_t n;
struct origin *o;
/*
* The origin's __minimum_chunk_size() got stored in max_io_len
* by snapshot_merge_resume().
*/
down_read(&_origins_lock);
o = __lookup_origin(merging_snap->origin->bdev);
for (n = 0; n < size; n += merging_snap->ti->max_io_len)
if (__origin_write(&o->snapshots, sector + n, NULL) ==
DM_MAPIO_SUBMITTED)
must_wait = 1;
up_read(&_origins_lock);
return must_wait;
}
/*
* Origin: maps a linear range of a device, with hooks for snapshotting.
*/
/*
* Construct an origin mapping: <dev_path>
* The context for an origin is merely a 'struct dm_dev *'
* pointing to the real device.
*/
static int origin_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
int r;
struct dm_origin *o;
if (argc != 1) {
ti->error = "origin: incorrect number of arguments";
return -EINVAL;
}
o = kmalloc(sizeof(struct dm_origin), GFP_KERNEL);
if (!o) {
ti->error = "Cannot allocate private origin structure";
r = -ENOMEM;
goto bad_alloc;
}
r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &o->dev);
if (r) {
ti->error = "Cannot get target device";
goto bad_open;
}
o->ti = ti;
ti->private = o;
ti->num_flush_bios = 1;
return 0;
bad_open:
kfree(o);
bad_alloc:
return r;
}
static void origin_dtr(struct dm_target *ti)
{
struct dm_origin *o = ti->private;
dm_put_device(ti, o->dev);
kfree(o);
}
static int origin_map(struct dm_target *ti, struct bio *bio)
{
struct dm_origin *o = ti->private;
unsigned int available_sectors;
bio_set_dev(bio, o->dev->bdev);
if (unlikely(bio->bi_opf & REQ_PREFLUSH))
return DM_MAPIO_REMAPPED;
if (bio_data_dir(bio) != WRITE)
return DM_MAPIO_REMAPPED;
available_sectors = o->split_boundary -
((unsigned int)bio->bi_iter.bi_sector & (o->split_boundary - 1));
if (bio_sectors(bio) > available_sectors)
dm_accept_partial_bio(bio, available_sectors);
/* Only tell snapshots if this is a write */
return do_origin(o->dev, bio, true);
}
/*
* Set the target "max_io_len" field to the minimum of all the snapshots'
* chunk sizes.
*/
static void origin_resume(struct dm_target *ti)
{
struct dm_origin *o = ti->private;
o->split_boundary = get_origin_minimum_chunksize(o->dev->bdev);
down_write(&_origins_lock);
__insert_dm_origin(o);
up_write(&_origins_lock);
}
static void origin_postsuspend(struct dm_target *ti)
{
struct dm_origin *o = ti->private;
down_write(&_origins_lock);
__remove_dm_origin(o);
up_write(&_origins_lock);
}
static void origin_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
struct dm_origin *o = ti->private;
switch (type) {
case STATUSTYPE_INFO:
result[0] = '\0';
break;
case STATUSTYPE_TABLE:
snprintf(result, maxlen, "%s", o->dev->name);
break;
case STATUSTYPE_IMA:
result[0] = '\0';
break;
}
}
static int origin_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct dm_origin *o = ti->private;
return fn(ti, o->dev, 0, ti->len, data);
}
static struct target_type origin_target = {
.name = "snapshot-origin",
.version = {1, 9, 0},
.module = THIS_MODULE,
.ctr = origin_ctr,
.dtr = origin_dtr,
.map = origin_map,
.resume = origin_resume,
.postsuspend = origin_postsuspend,
.status = origin_status,
.iterate_devices = origin_iterate_devices,
};
static struct target_type snapshot_target = {
.name = "snapshot",
.version = {1, 16, 0},
.module = THIS_MODULE,
.ctr = snapshot_ctr,
.dtr = snapshot_dtr,
.map = snapshot_map,
.end_io = snapshot_end_io,
.preresume = snapshot_preresume,
.resume = snapshot_resume,
.status = snapshot_status,
.iterate_devices = snapshot_iterate_devices,
.io_hints = snapshot_io_hints,
};
static struct target_type merge_target = {
.name = dm_snapshot_merge_target_name,
.version = {1, 5, 0},
.module = THIS_MODULE,
.ctr = snapshot_ctr,
.dtr = snapshot_dtr,
.map = snapshot_merge_map,
.end_io = snapshot_end_io,
.presuspend = snapshot_merge_presuspend,
.preresume = snapshot_preresume,
.resume = snapshot_merge_resume,
.status = snapshot_status,
.iterate_devices = snapshot_iterate_devices,
.io_hints = snapshot_io_hints,
};
static int __init dm_snapshot_init(void)
{
int r;
r = dm_exception_store_init();
if (r) {
DMERR("Failed to initialize exception stores");
return r;
}
r = init_origin_hash();
if (r) {
DMERR("init_origin_hash failed.");
goto bad_origin_hash;
}
exception_cache = KMEM_CACHE(dm_exception, 0);
if (!exception_cache) {
DMERR("Couldn't create exception cache.");
r = -ENOMEM;
goto bad_exception_cache;
}
pending_cache = KMEM_CACHE(dm_snap_pending_exception, 0);
if (!pending_cache) {
DMERR("Couldn't create pending cache.");
r = -ENOMEM;
goto bad_pending_cache;
}
r = dm_register_target(&snapshot_target);
if (r < 0)
goto bad_register_snapshot_target;
r = dm_register_target(&origin_target);
if (r < 0)
goto bad_register_origin_target;
r = dm_register_target(&merge_target);
if (r < 0)
goto bad_register_merge_target;
return 0;
bad_register_merge_target:
dm_unregister_target(&origin_target);
bad_register_origin_target:
dm_unregister_target(&snapshot_target);
bad_register_snapshot_target:
kmem_cache_destroy(pending_cache);
bad_pending_cache:
kmem_cache_destroy(exception_cache);
bad_exception_cache:
exit_origin_hash();
bad_origin_hash:
dm_exception_store_exit();
return r;
}
static void __exit dm_snapshot_exit(void)
{
dm_unregister_target(&snapshot_target);
dm_unregister_target(&origin_target);
dm_unregister_target(&merge_target);
exit_origin_hash();
kmem_cache_destroy(pending_cache);
kmem_cache_destroy(exception_cache);
dm_exception_store_exit();
}
/* Module hooks */
module_init(dm_snapshot_init);
module_exit(dm_snapshot_exit);
MODULE_DESCRIPTION(DM_NAME " snapshot target");
MODULE_AUTHOR("Joe Thornber");
MODULE_LICENSE("GPL");
MODULE_ALIAS("dm-snapshot-origin");
MODULE_ALIAS("dm-snapshot-merge");
| linux-master | drivers/md/dm-snap.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2018 Red Hat. All rights reserved.
*
* This file is released under the GPL.
*/
#include <linux/device-mapper.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/vmalloc.h>
#include <linux/kthread.h>
#include <linux/dm-io.h>
#include <linux/dm-kcopyd.h>
#include <linux/dax.h>
#include <linux/pfn_t.h>
#include <linux/libnvdimm.h>
#include <linux/delay.h>
#include "dm-io-tracker.h"
#define DM_MSG_PREFIX "writecache"
#define HIGH_WATERMARK 50
#define LOW_WATERMARK 45
#define MAX_WRITEBACK_JOBS min(0x10000000 / PAGE_SIZE, totalram_pages() / 16)
#define ENDIO_LATENCY 16
#define WRITEBACK_LATENCY 64
#define AUTOCOMMIT_BLOCKS_SSD 65536
#define AUTOCOMMIT_BLOCKS_PMEM 64
#define AUTOCOMMIT_MSEC 1000
#define MAX_AGE_DIV 16
#define MAX_AGE_UNSPECIFIED -1UL
#define PAUSE_WRITEBACK (HZ * 3)
#define BITMAP_GRANULARITY 65536
#if BITMAP_GRANULARITY < PAGE_SIZE
#undef BITMAP_GRANULARITY
#define BITMAP_GRANULARITY PAGE_SIZE
#endif
#if IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API) && IS_ENABLED(CONFIG_FS_DAX)
#define DM_WRITECACHE_HAS_PMEM
#endif
#ifdef DM_WRITECACHE_HAS_PMEM
#define pmem_assign(dest, src) \
do { \
typeof(dest) uniq = (src); \
memcpy_flushcache(&(dest), &uniq, sizeof(dest)); \
} while (0)
#else
#define pmem_assign(dest, src) ((dest) = (src))
#endif
#if IS_ENABLED(CONFIG_ARCH_HAS_COPY_MC) && defined(DM_WRITECACHE_HAS_PMEM)
#define DM_WRITECACHE_HANDLE_HARDWARE_ERRORS
#endif
#define MEMORY_SUPERBLOCK_MAGIC 0x23489321
#define MEMORY_SUPERBLOCK_VERSION 1
struct wc_memory_entry {
__le64 original_sector;
__le64 seq_count;
};
struct wc_memory_superblock {
union {
struct {
__le32 magic;
__le32 version;
__le32 block_size;
__le32 pad;
__le64 n_blocks;
__le64 seq_count;
};
__le64 padding[8];
};
struct wc_memory_entry entries[];
};
struct wc_entry {
struct rb_node rb_node;
struct list_head lru;
unsigned short wc_list_contiguous;
#if BITS_PER_LONG == 64
bool write_in_progress : 1;
unsigned long index : 47;
#else
bool write_in_progress;
unsigned long index;
#endif
unsigned long age;
#ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS
uint64_t original_sector;
uint64_t seq_count;
#endif
};
#ifdef DM_WRITECACHE_HAS_PMEM
#define WC_MODE_PMEM(wc) ((wc)->pmem_mode)
#define WC_MODE_FUA(wc) ((wc)->writeback_fua)
#else
#define WC_MODE_PMEM(wc) false
#define WC_MODE_FUA(wc) false
#endif
#define WC_MODE_SORT_FREELIST(wc) (!WC_MODE_PMEM(wc))
struct dm_writecache {
struct mutex lock;
struct list_head lru;
union {
struct list_head freelist;
struct {
struct rb_root freetree;
struct wc_entry *current_free;
};
};
struct rb_root tree;
size_t freelist_size;
size_t writeback_size;
size_t freelist_high_watermark;
size_t freelist_low_watermark;
unsigned long max_age;
unsigned long pause;
unsigned int uncommitted_blocks;
unsigned int autocommit_blocks;
unsigned int max_writeback_jobs;
int error;
unsigned long autocommit_jiffies;
struct timer_list autocommit_timer;
struct wait_queue_head freelist_wait;
struct timer_list max_age_timer;
atomic_t bio_in_progress[2];
struct wait_queue_head bio_in_progress_wait[2];
struct dm_target *ti;
struct dm_dev *dev;
struct dm_dev *ssd_dev;
sector_t start_sector;
void *memory_map;
uint64_t memory_map_size;
size_t metadata_sectors;
size_t n_blocks;
uint64_t seq_count;
sector_t data_device_sectors;
void *block_start;
struct wc_entry *entries;
unsigned int block_size;
unsigned char block_size_bits;
bool pmem_mode:1;
bool writeback_fua:1;
bool overwrote_committed:1;
bool memory_vmapped:1;
bool start_sector_set:1;
bool high_wm_percent_set:1;
bool low_wm_percent_set:1;
bool max_writeback_jobs_set:1;
bool autocommit_blocks_set:1;
bool autocommit_time_set:1;
bool max_age_set:1;
bool writeback_fua_set:1;
bool flush_on_suspend:1;
bool cleaner:1;
bool cleaner_set:1;
bool metadata_only:1;
bool pause_set:1;
unsigned int high_wm_percent_value;
unsigned int low_wm_percent_value;
unsigned int autocommit_time_value;
unsigned int max_age_value;
unsigned int pause_value;
unsigned int writeback_all;
struct workqueue_struct *writeback_wq;
struct work_struct writeback_work;
struct work_struct flush_work;
struct dm_io_tracker iot;
struct dm_io_client *dm_io;
raw_spinlock_t endio_list_lock;
struct list_head endio_list;
struct task_struct *endio_thread;
struct task_struct *flush_thread;
struct bio_list flush_list;
struct dm_kcopyd_client *dm_kcopyd;
unsigned long *dirty_bitmap;
unsigned int dirty_bitmap_size;
struct bio_set bio_set;
mempool_t copy_pool;
struct {
unsigned long long reads;
unsigned long long read_hits;
unsigned long long writes;
unsigned long long write_hits_uncommitted;
unsigned long long write_hits_committed;
unsigned long long writes_around;
unsigned long long writes_allocate;
unsigned long long writes_blocked_on_freelist;
unsigned long long flushes;
unsigned long long discards;
} stats;
};
#define WB_LIST_INLINE 16
struct writeback_struct {
struct list_head endio_entry;
struct dm_writecache *wc;
struct wc_entry **wc_list;
unsigned int wc_list_n;
struct wc_entry *wc_list_inline[WB_LIST_INLINE];
struct bio bio;
};
struct copy_struct {
struct list_head endio_entry;
struct dm_writecache *wc;
struct wc_entry *e;
unsigned int n_entries;
int error;
};
DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(dm_writecache_throttle,
"A percentage of time allocated for data copying");
static void wc_lock(struct dm_writecache *wc)
{
mutex_lock(&wc->lock);
}
static void wc_unlock(struct dm_writecache *wc)
{
mutex_unlock(&wc->lock);
}
#ifdef DM_WRITECACHE_HAS_PMEM
static int persistent_memory_claim(struct dm_writecache *wc)
{
int r;
loff_t s;
long p, da;
pfn_t pfn;
int id;
struct page **pages;
sector_t offset;
wc->memory_vmapped = false;
s = wc->memory_map_size;
p = s >> PAGE_SHIFT;
if (!p) {
r = -EINVAL;
goto err1;
}
if (p != s >> PAGE_SHIFT) {
r = -EOVERFLOW;
goto err1;
}
offset = get_start_sect(wc->ssd_dev->bdev);
if (offset & (PAGE_SIZE / 512 - 1)) {
r = -EINVAL;
goto err1;
}
offset >>= PAGE_SHIFT - 9;
id = dax_read_lock();
da = dax_direct_access(wc->ssd_dev->dax_dev, offset, p, DAX_ACCESS,
&wc->memory_map, &pfn);
if (da < 0) {
wc->memory_map = NULL;
r = da;
goto err2;
}
if (!pfn_t_has_page(pfn)) {
wc->memory_map = NULL;
r = -EOPNOTSUPP;
goto err2;
}
if (da != p) {
long i;
wc->memory_map = NULL;
pages = kvmalloc_array(p, sizeof(struct page *), GFP_KERNEL);
if (!pages) {
r = -ENOMEM;
goto err2;
}
i = 0;
do {
long daa;
daa = dax_direct_access(wc->ssd_dev->dax_dev, offset + i,
p - i, DAX_ACCESS, NULL, &pfn);
if (daa <= 0) {
r = daa ? daa : -EINVAL;
goto err3;
}
if (!pfn_t_has_page(pfn)) {
r = -EOPNOTSUPP;
goto err3;
}
while (daa-- && i < p) {
pages[i++] = pfn_t_to_page(pfn);
pfn.val++;
if (!(i & 15))
cond_resched();
}
} while (i < p);
wc->memory_map = vmap(pages, p, VM_MAP, PAGE_KERNEL);
if (!wc->memory_map) {
r = -ENOMEM;
goto err3;
}
kvfree(pages);
wc->memory_vmapped = true;
}
dax_read_unlock(id);
wc->memory_map += (size_t)wc->start_sector << SECTOR_SHIFT;
wc->memory_map_size -= (size_t)wc->start_sector << SECTOR_SHIFT;
return 0;
err3:
kvfree(pages);
err2:
dax_read_unlock(id);
err1:
return r;
}
#else
static int persistent_memory_claim(struct dm_writecache *wc)
{
return -EOPNOTSUPP;
}
#endif
static void persistent_memory_release(struct dm_writecache *wc)
{
if (wc->memory_vmapped)
vunmap(wc->memory_map - ((size_t)wc->start_sector << SECTOR_SHIFT));
}
static struct page *persistent_memory_page(void *addr)
{
if (is_vmalloc_addr(addr))
return vmalloc_to_page(addr);
else
return virt_to_page(addr);
}
static unsigned int persistent_memory_page_offset(void *addr)
{
return (unsigned long)addr & (PAGE_SIZE - 1);
}
static void persistent_memory_flush_cache(void *ptr, size_t size)
{
if (is_vmalloc_addr(ptr))
flush_kernel_vmap_range(ptr, size);
}
static void persistent_memory_invalidate_cache(void *ptr, size_t size)
{
if (is_vmalloc_addr(ptr))
invalidate_kernel_vmap_range(ptr, size);
}
static struct wc_memory_superblock *sb(struct dm_writecache *wc)
{
return wc->memory_map;
}
static struct wc_memory_entry *memory_entry(struct dm_writecache *wc, struct wc_entry *e)
{
return &sb(wc)->entries[e->index];
}
static void *memory_data(struct dm_writecache *wc, struct wc_entry *e)
{
return (char *)wc->block_start + (e->index << wc->block_size_bits);
}
static sector_t cache_sector(struct dm_writecache *wc, struct wc_entry *e)
{
return wc->start_sector + wc->metadata_sectors +
((sector_t)e->index << (wc->block_size_bits - SECTOR_SHIFT));
}
static uint64_t read_original_sector(struct dm_writecache *wc, struct wc_entry *e)
{
#ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS
return e->original_sector;
#else
return le64_to_cpu(memory_entry(wc, e)->original_sector);
#endif
}
static uint64_t read_seq_count(struct dm_writecache *wc, struct wc_entry *e)
{
#ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS
return e->seq_count;
#else
return le64_to_cpu(memory_entry(wc, e)->seq_count);
#endif
}
static void clear_seq_count(struct dm_writecache *wc, struct wc_entry *e)
{
#ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS
e->seq_count = -1;
#endif
pmem_assign(memory_entry(wc, e)->seq_count, cpu_to_le64(-1));
}
static void write_original_sector_seq_count(struct dm_writecache *wc, struct wc_entry *e,
uint64_t original_sector, uint64_t seq_count)
{
struct wc_memory_entry me;
#ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS
e->original_sector = original_sector;
e->seq_count = seq_count;
#endif
me.original_sector = cpu_to_le64(original_sector);
me.seq_count = cpu_to_le64(seq_count);
pmem_assign(*memory_entry(wc, e), me);
}
#define writecache_error(wc, err, msg, arg...) \
do { \
if (!cmpxchg(&(wc)->error, 0, err)) \
DMERR(msg, ##arg); \
wake_up(&(wc)->freelist_wait); \
} while (0)
#define writecache_has_error(wc) (unlikely(READ_ONCE((wc)->error)))
static void writecache_flush_all_metadata(struct dm_writecache *wc)
{
if (!WC_MODE_PMEM(wc))
memset(wc->dirty_bitmap, -1, wc->dirty_bitmap_size);
}
static void writecache_flush_region(struct dm_writecache *wc, void *ptr, size_t size)
{
if (!WC_MODE_PMEM(wc))
__set_bit(((char *)ptr - (char *)wc->memory_map) / BITMAP_GRANULARITY,
wc->dirty_bitmap);
}
static void writecache_disk_flush(struct dm_writecache *wc, struct dm_dev *dev);
struct io_notify {
struct dm_writecache *wc;
struct completion c;
atomic_t count;
};
static void writecache_notify_io(unsigned long error, void *context)
{
struct io_notify *endio = context;
if (unlikely(error != 0))
writecache_error(endio->wc, -EIO, "error writing metadata");
BUG_ON(atomic_read(&endio->count) <= 0);
if (atomic_dec_and_test(&endio->count))
complete(&endio->c);
}
static void writecache_wait_for_ios(struct dm_writecache *wc, int direction)
{
wait_event(wc->bio_in_progress_wait[direction],
!atomic_read(&wc->bio_in_progress[direction]));
}
static void ssd_commit_flushed(struct dm_writecache *wc, bool wait_for_ios)
{
struct dm_io_region region;
struct dm_io_request req;
struct io_notify endio = {
wc,
COMPLETION_INITIALIZER_ONSTACK(endio.c),
ATOMIC_INIT(1),
};
unsigned int bitmap_bits = wc->dirty_bitmap_size * 8;
unsigned int i = 0;
while (1) {
unsigned int j;
i = find_next_bit(wc->dirty_bitmap, bitmap_bits, i);
if (unlikely(i == bitmap_bits))
break;
j = find_next_zero_bit(wc->dirty_bitmap, bitmap_bits, i);
region.bdev = wc->ssd_dev->bdev;
region.sector = (sector_t)i * (BITMAP_GRANULARITY >> SECTOR_SHIFT);
region.count = (sector_t)(j - i) * (BITMAP_GRANULARITY >> SECTOR_SHIFT);
if (unlikely(region.sector >= wc->metadata_sectors))
break;
if (unlikely(region.sector + region.count > wc->metadata_sectors))
region.count = wc->metadata_sectors - region.sector;
region.sector += wc->start_sector;
atomic_inc(&endio.count);
req.bi_opf = REQ_OP_WRITE | REQ_SYNC;
req.mem.type = DM_IO_VMA;
req.mem.ptr.vma = (char *)wc->memory_map + (size_t)i * BITMAP_GRANULARITY;
req.client = wc->dm_io;
req.notify.fn = writecache_notify_io;
req.notify.context = &endio;
/* writing via async dm-io (implied by notify.fn above) won't return an error */
(void) dm_io(&req, 1, ®ion, NULL);
i = j;
}
writecache_notify_io(0, &endio);
wait_for_completion_io(&endio.c);
if (wait_for_ios)
writecache_wait_for_ios(wc, WRITE);
writecache_disk_flush(wc, wc->ssd_dev);
memset(wc->dirty_bitmap, 0, wc->dirty_bitmap_size);
}
static void ssd_commit_superblock(struct dm_writecache *wc)
{
int r;
struct dm_io_region region;
struct dm_io_request req;
region.bdev = wc->ssd_dev->bdev;
region.sector = 0;
region.count = max(4096U, wc->block_size) >> SECTOR_SHIFT;
if (unlikely(region.sector + region.count > wc->metadata_sectors))
region.count = wc->metadata_sectors - region.sector;
region.sector += wc->start_sector;
req.bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_FUA;
req.mem.type = DM_IO_VMA;
req.mem.ptr.vma = (char *)wc->memory_map;
req.client = wc->dm_io;
req.notify.fn = NULL;
req.notify.context = NULL;
r = dm_io(&req, 1, ®ion, NULL);
if (unlikely(r))
writecache_error(wc, r, "error writing superblock");
}
static void writecache_commit_flushed(struct dm_writecache *wc, bool wait_for_ios)
{
if (WC_MODE_PMEM(wc))
pmem_wmb();
else
ssd_commit_flushed(wc, wait_for_ios);
}
static void writecache_disk_flush(struct dm_writecache *wc, struct dm_dev *dev)
{
int r;
struct dm_io_region region;
struct dm_io_request req;
region.bdev = dev->bdev;
region.sector = 0;
region.count = 0;
req.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
req.mem.type = DM_IO_KMEM;
req.mem.ptr.addr = NULL;
req.client = wc->dm_io;
req.notify.fn = NULL;
r = dm_io(&req, 1, ®ion, NULL);
if (unlikely(r))
writecache_error(wc, r, "error flushing metadata: %d", r);
}
#define WFE_RETURN_FOLLOWING 1
#define WFE_LOWEST_SEQ 2
static struct wc_entry *writecache_find_entry(struct dm_writecache *wc,
uint64_t block, int flags)
{
struct wc_entry *e;
struct rb_node *node = wc->tree.rb_node;
if (unlikely(!node))
return NULL;
while (1) {
e = container_of(node, struct wc_entry, rb_node);
if (read_original_sector(wc, e) == block)
break;
node = (read_original_sector(wc, e) >= block ?
e->rb_node.rb_left : e->rb_node.rb_right);
if (unlikely(!node)) {
if (!(flags & WFE_RETURN_FOLLOWING))
return NULL;
if (read_original_sector(wc, e) >= block)
return e;
node = rb_next(&e->rb_node);
if (unlikely(!node))
return NULL;
e = container_of(node, struct wc_entry, rb_node);
return e;
}
}
while (1) {
struct wc_entry *e2;
if (flags & WFE_LOWEST_SEQ)
node = rb_prev(&e->rb_node);
else
node = rb_next(&e->rb_node);
if (unlikely(!node))
return e;
e2 = container_of(node, struct wc_entry, rb_node);
if (read_original_sector(wc, e2) != block)
return e;
e = e2;
}
}
static void writecache_insert_entry(struct dm_writecache *wc, struct wc_entry *ins)
{
struct wc_entry *e;
struct rb_node **node = &wc->tree.rb_node, *parent = NULL;
while (*node) {
e = container_of(*node, struct wc_entry, rb_node);
parent = &e->rb_node;
if (read_original_sector(wc, e) > read_original_sector(wc, ins))
node = &parent->rb_left;
else
node = &parent->rb_right;
}
rb_link_node(&ins->rb_node, parent, node);
rb_insert_color(&ins->rb_node, &wc->tree);
list_add(&ins->lru, &wc->lru);
ins->age = jiffies;
}
static void writecache_unlink(struct dm_writecache *wc, struct wc_entry *e)
{
list_del(&e->lru);
rb_erase(&e->rb_node, &wc->tree);
}
static void writecache_add_to_freelist(struct dm_writecache *wc, struct wc_entry *e)
{
if (WC_MODE_SORT_FREELIST(wc)) {
struct rb_node **node = &wc->freetree.rb_node, *parent = NULL;
if (unlikely(!*node))
wc->current_free = e;
while (*node) {
parent = *node;
if (&e->rb_node < *node)
node = &parent->rb_left;
else
node = &parent->rb_right;
}
rb_link_node(&e->rb_node, parent, node);
rb_insert_color(&e->rb_node, &wc->freetree);
} else {
list_add_tail(&e->lru, &wc->freelist);
}
wc->freelist_size++;
}
static inline void writecache_verify_watermark(struct dm_writecache *wc)
{
if (unlikely(wc->freelist_size + wc->writeback_size <= wc->freelist_high_watermark))
queue_work(wc->writeback_wq, &wc->writeback_work);
}
static void writecache_max_age_timer(struct timer_list *t)
{
struct dm_writecache *wc = from_timer(wc, t, max_age_timer);
if (!dm_suspended(wc->ti) && !writecache_has_error(wc)) {
queue_work(wc->writeback_wq, &wc->writeback_work);
mod_timer(&wc->max_age_timer, jiffies + wc->max_age / MAX_AGE_DIV);
}
}
static struct wc_entry *writecache_pop_from_freelist(struct dm_writecache *wc, sector_t expected_sector)
{
struct wc_entry *e;
if (WC_MODE_SORT_FREELIST(wc)) {
struct rb_node *next;
if (unlikely(!wc->current_free))
return NULL;
e = wc->current_free;
if (expected_sector != (sector_t)-1 && unlikely(cache_sector(wc, e) != expected_sector))
return NULL;
next = rb_next(&e->rb_node);
rb_erase(&e->rb_node, &wc->freetree);
if (unlikely(!next))
next = rb_first(&wc->freetree);
wc->current_free = next ? container_of(next, struct wc_entry, rb_node) : NULL;
} else {
if (unlikely(list_empty(&wc->freelist)))
return NULL;
e = container_of(wc->freelist.next, struct wc_entry, lru);
if (expected_sector != (sector_t)-1 && unlikely(cache_sector(wc, e) != expected_sector))
return NULL;
list_del(&e->lru);
}
wc->freelist_size--;
writecache_verify_watermark(wc);
return e;
}
static void writecache_free_entry(struct dm_writecache *wc, struct wc_entry *e)
{
writecache_unlink(wc, e);
writecache_add_to_freelist(wc, e);
clear_seq_count(wc, e);
writecache_flush_region(wc, memory_entry(wc, e), sizeof(struct wc_memory_entry));
if (unlikely(waitqueue_active(&wc->freelist_wait)))
wake_up(&wc->freelist_wait);
}
static void writecache_wait_on_freelist(struct dm_writecache *wc)
{
DEFINE_WAIT(wait);
prepare_to_wait(&wc->freelist_wait, &wait, TASK_UNINTERRUPTIBLE);
wc_unlock(wc);
io_schedule();
finish_wait(&wc->freelist_wait, &wait);
wc_lock(wc);
}
static void writecache_poison_lists(struct dm_writecache *wc)
{
/*
* Catch incorrect access to these values while the device is suspended.
*/
memset(&wc->tree, -1, sizeof(wc->tree));
wc->lru.next = LIST_POISON1;
wc->lru.prev = LIST_POISON2;
wc->freelist.next = LIST_POISON1;
wc->freelist.prev = LIST_POISON2;
}
static void writecache_flush_entry(struct dm_writecache *wc, struct wc_entry *e)
{
writecache_flush_region(wc, memory_entry(wc, e), sizeof(struct wc_memory_entry));
if (WC_MODE_PMEM(wc))
writecache_flush_region(wc, memory_data(wc, e), wc->block_size);
}
static bool writecache_entry_is_committed(struct dm_writecache *wc, struct wc_entry *e)
{
return read_seq_count(wc, e) < wc->seq_count;
}
static void writecache_flush(struct dm_writecache *wc)
{
struct wc_entry *e, *e2;
bool need_flush_after_free;
wc->uncommitted_blocks = 0;
del_timer(&wc->autocommit_timer);
if (list_empty(&wc->lru))
return;
e = container_of(wc->lru.next, struct wc_entry, lru);
if (writecache_entry_is_committed(wc, e)) {
if (wc->overwrote_committed) {
writecache_wait_for_ios(wc, WRITE);
writecache_disk_flush(wc, wc->ssd_dev);
wc->overwrote_committed = false;
}
return;
}
while (1) {
writecache_flush_entry(wc, e);
if (unlikely(e->lru.next == &wc->lru))
break;
e2 = container_of(e->lru.next, struct wc_entry, lru);
if (writecache_entry_is_committed(wc, e2))
break;
e = e2;
cond_resched();
}
writecache_commit_flushed(wc, true);
wc->seq_count++;
pmem_assign(sb(wc)->seq_count, cpu_to_le64(wc->seq_count));
if (WC_MODE_PMEM(wc))
writecache_commit_flushed(wc, false);
else
ssd_commit_superblock(wc);
wc->overwrote_committed = false;
need_flush_after_free = false;
while (1) {
/* Free another committed entry with lower seq-count */
struct rb_node *rb_node = rb_prev(&e->rb_node);
if (rb_node) {
e2 = container_of(rb_node, struct wc_entry, rb_node);
if (read_original_sector(wc, e2) == read_original_sector(wc, e) &&
likely(!e2->write_in_progress)) {
writecache_free_entry(wc, e2);
need_flush_after_free = true;
}
}
if (unlikely(e->lru.prev == &wc->lru))
break;
e = container_of(e->lru.prev, struct wc_entry, lru);
cond_resched();
}
if (need_flush_after_free)
writecache_commit_flushed(wc, false);
}
static void writecache_flush_work(struct work_struct *work)
{
struct dm_writecache *wc = container_of(work, struct dm_writecache, flush_work);
wc_lock(wc);
writecache_flush(wc);
wc_unlock(wc);
}
static void writecache_autocommit_timer(struct timer_list *t)
{
struct dm_writecache *wc = from_timer(wc, t, autocommit_timer);
if (!writecache_has_error(wc))
queue_work(wc->writeback_wq, &wc->flush_work);
}
static void writecache_schedule_autocommit(struct dm_writecache *wc)
{
if (!timer_pending(&wc->autocommit_timer))
mod_timer(&wc->autocommit_timer, jiffies + wc->autocommit_jiffies);
}
static void writecache_discard(struct dm_writecache *wc, sector_t start, sector_t end)
{
struct wc_entry *e;
bool discarded_something = false;
e = writecache_find_entry(wc, start, WFE_RETURN_FOLLOWING | WFE_LOWEST_SEQ);
if (unlikely(!e))
return;
while (read_original_sector(wc, e) < end) {
struct rb_node *node = rb_next(&e->rb_node);
if (likely(!e->write_in_progress)) {
if (!discarded_something) {
if (!WC_MODE_PMEM(wc)) {
writecache_wait_for_ios(wc, READ);
writecache_wait_for_ios(wc, WRITE);
}
discarded_something = true;
}
if (!writecache_entry_is_committed(wc, e))
wc->uncommitted_blocks--;
writecache_free_entry(wc, e);
}
if (unlikely(!node))
break;
e = container_of(node, struct wc_entry, rb_node);
}
if (discarded_something)
writecache_commit_flushed(wc, false);
}
static bool writecache_wait_for_writeback(struct dm_writecache *wc)
{
if (wc->writeback_size) {
writecache_wait_on_freelist(wc);
return true;
}
return false;
}
static void writecache_suspend(struct dm_target *ti)
{
struct dm_writecache *wc = ti->private;
bool flush_on_suspend;
del_timer_sync(&wc->autocommit_timer);
del_timer_sync(&wc->max_age_timer);
wc_lock(wc);
writecache_flush(wc);
flush_on_suspend = wc->flush_on_suspend;
if (flush_on_suspend) {
wc->flush_on_suspend = false;
wc->writeback_all++;
queue_work(wc->writeback_wq, &wc->writeback_work);
}
wc_unlock(wc);
drain_workqueue(wc->writeback_wq);
wc_lock(wc);
if (flush_on_suspend)
wc->writeback_all--;
while (writecache_wait_for_writeback(wc))
;
if (WC_MODE_PMEM(wc))
persistent_memory_flush_cache(wc->memory_map, wc->memory_map_size);
writecache_poison_lists(wc);
wc_unlock(wc);
}
static int writecache_alloc_entries(struct dm_writecache *wc)
{
size_t b;
if (wc->entries)
return 0;
wc->entries = vmalloc(array_size(sizeof(struct wc_entry), wc->n_blocks));
if (!wc->entries)
return -ENOMEM;
for (b = 0; b < wc->n_blocks; b++) {
struct wc_entry *e = &wc->entries[b];
e->index = b;
e->write_in_progress = false;
cond_resched();
}
return 0;
}
static int writecache_read_metadata(struct dm_writecache *wc, sector_t n_sectors)
{
struct dm_io_region region;
struct dm_io_request req;
region.bdev = wc->ssd_dev->bdev;
region.sector = wc->start_sector;
region.count = n_sectors;
req.bi_opf = REQ_OP_READ | REQ_SYNC;
req.mem.type = DM_IO_VMA;
req.mem.ptr.vma = (char *)wc->memory_map;
req.client = wc->dm_io;
req.notify.fn = NULL;
return dm_io(&req, 1, ®ion, NULL);
}
static void writecache_resume(struct dm_target *ti)
{
struct dm_writecache *wc = ti->private;
size_t b;
bool need_flush = false;
__le64 sb_seq_count;
int r;
wc_lock(wc);
wc->data_device_sectors = bdev_nr_sectors(wc->dev->bdev);
if (WC_MODE_PMEM(wc)) {
persistent_memory_invalidate_cache(wc->memory_map, wc->memory_map_size);
} else {
r = writecache_read_metadata(wc, wc->metadata_sectors);
if (r) {
size_t sb_entries_offset;
writecache_error(wc, r, "unable to read metadata: %d", r);
sb_entries_offset = offsetof(struct wc_memory_superblock, entries);
memset((char *)wc->memory_map + sb_entries_offset, -1,
(wc->metadata_sectors << SECTOR_SHIFT) - sb_entries_offset);
}
}
wc->tree = RB_ROOT;
INIT_LIST_HEAD(&wc->lru);
if (WC_MODE_SORT_FREELIST(wc)) {
wc->freetree = RB_ROOT;
wc->current_free = NULL;
} else {
INIT_LIST_HEAD(&wc->freelist);
}
wc->freelist_size = 0;
r = copy_mc_to_kernel(&sb_seq_count, &sb(wc)->seq_count,
sizeof(uint64_t));
if (r) {
writecache_error(wc, r, "hardware memory error when reading superblock: %d", r);
sb_seq_count = cpu_to_le64(0);
}
wc->seq_count = le64_to_cpu(sb_seq_count);
#ifdef DM_WRITECACHE_HANDLE_HARDWARE_ERRORS
for (b = 0; b < wc->n_blocks; b++) {
struct wc_entry *e = &wc->entries[b];
struct wc_memory_entry wme;
if (writecache_has_error(wc)) {
e->original_sector = -1;
e->seq_count = -1;
continue;
}
r = copy_mc_to_kernel(&wme, memory_entry(wc, e),
sizeof(struct wc_memory_entry));
if (r) {
writecache_error(wc, r, "hardware memory error when reading metadata entry %lu: %d",
(unsigned long)b, r);
e->original_sector = -1;
e->seq_count = -1;
} else {
e->original_sector = le64_to_cpu(wme.original_sector);
e->seq_count = le64_to_cpu(wme.seq_count);
}
cond_resched();
}
#endif
for (b = 0; b < wc->n_blocks; b++) {
struct wc_entry *e = &wc->entries[b];
if (!writecache_entry_is_committed(wc, e)) {
if (read_seq_count(wc, e) != -1) {
erase_this:
clear_seq_count(wc, e);
need_flush = true;
}
writecache_add_to_freelist(wc, e);
} else {
struct wc_entry *old;
old = writecache_find_entry(wc, read_original_sector(wc, e), 0);
if (!old) {
writecache_insert_entry(wc, e);
} else {
if (read_seq_count(wc, old) == read_seq_count(wc, e)) {
writecache_error(wc, -EINVAL,
"two identical entries, position %llu, sector %llu, sequence %llu",
(unsigned long long)b, (unsigned long long)read_original_sector(wc, e),
(unsigned long long)read_seq_count(wc, e));
}
if (read_seq_count(wc, old) > read_seq_count(wc, e)) {
goto erase_this;
} else {
writecache_free_entry(wc, old);
writecache_insert_entry(wc, e);
need_flush = true;
}
}
}
cond_resched();
}
if (need_flush) {
writecache_flush_all_metadata(wc);
writecache_commit_flushed(wc, false);
}
writecache_verify_watermark(wc);
if (wc->max_age != MAX_AGE_UNSPECIFIED)
mod_timer(&wc->max_age_timer, jiffies + wc->max_age / MAX_AGE_DIV);
wc_unlock(wc);
}
static int process_flush_mesg(unsigned int argc, char **argv, struct dm_writecache *wc)
{
if (argc != 1)
return -EINVAL;
wc_lock(wc);
if (dm_suspended(wc->ti)) {
wc_unlock(wc);
return -EBUSY;
}
if (writecache_has_error(wc)) {
wc_unlock(wc);
return -EIO;
}
writecache_flush(wc);
wc->writeback_all++;
queue_work(wc->writeback_wq, &wc->writeback_work);
wc_unlock(wc);
flush_workqueue(wc->writeback_wq);
wc_lock(wc);
wc->writeback_all--;
if (writecache_has_error(wc)) {
wc_unlock(wc);
return -EIO;
}
wc_unlock(wc);
return 0;
}
static int process_flush_on_suspend_mesg(unsigned int argc, char **argv, struct dm_writecache *wc)
{
if (argc != 1)
return -EINVAL;
wc_lock(wc);
wc->flush_on_suspend = true;
wc_unlock(wc);
return 0;
}
static void activate_cleaner(struct dm_writecache *wc)
{
wc->flush_on_suspend = true;
wc->cleaner = true;
wc->freelist_high_watermark = wc->n_blocks;
wc->freelist_low_watermark = wc->n_blocks;
}
static int process_cleaner_mesg(unsigned int argc, char **argv, struct dm_writecache *wc)
{
if (argc != 1)
return -EINVAL;
wc_lock(wc);
activate_cleaner(wc);
if (!dm_suspended(wc->ti))
writecache_verify_watermark(wc);
wc_unlock(wc);
return 0;
}
static int process_clear_stats_mesg(unsigned int argc, char **argv, struct dm_writecache *wc)
{
if (argc != 1)
return -EINVAL;
wc_lock(wc);
memset(&wc->stats, 0, sizeof(wc->stats));
wc_unlock(wc);
return 0;
}
static int writecache_message(struct dm_target *ti, unsigned int argc, char **argv,
char *result, unsigned int maxlen)
{
int r = -EINVAL;
struct dm_writecache *wc = ti->private;
if (!strcasecmp(argv[0], "flush"))
r = process_flush_mesg(argc, argv, wc);
else if (!strcasecmp(argv[0], "flush_on_suspend"))
r = process_flush_on_suspend_mesg(argc, argv, wc);
else if (!strcasecmp(argv[0], "cleaner"))
r = process_cleaner_mesg(argc, argv, wc);
else if (!strcasecmp(argv[0], "clear_stats"))
r = process_clear_stats_mesg(argc, argv, wc);
else
DMERR("unrecognised message received: %s", argv[0]);
return r;
}
static void memcpy_flushcache_optimized(void *dest, void *source, size_t size)
{
/*
* clflushopt performs better with block size 1024, 2048, 4096
* non-temporal stores perform better with block size 512
*
* block size 512 1024 2048 4096
* movnti 496 MB/s 642 MB/s 725 MB/s 744 MB/s
* clflushopt 373 MB/s 688 MB/s 1.1 GB/s 1.2 GB/s
*
* We see that movnti performs better for 512-byte blocks, and
* clflushopt performs better for 1024-byte and larger blocks. So, we
* prefer clflushopt for sizes >= 768.
*
* NOTE: this happens to be the case now (with dm-writecache's single
* threaded model) but re-evaluate this once memcpy_flushcache() is
* enabled to use movdir64b which might invalidate this performance
* advantage seen with cache-allocating-writes plus flushing.
*/
#ifdef CONFIG_X86
if (static_cpu_has(X86_FEATURE_CLFLUSHOPT) &&
likely(boot_cpu_data.x86_clflush_size == 64) &&
likely(size >= 768)) {
do {
memcpy((void *)dest, (void *)source, 64);
clflushopt((void *)dest);
dest += 64;
source += 64;
size -= 64;
} while (size >= 64);
return;
}
#endif
memcpy_flushcache(dest, source, size);
}
static void bio_copy_block(struct dm_writecache *wc, struct bio *bio, void *data)
{
void *buf;
unsigned int size;
int rw = bio_data_dir(bio);
unsigned int remaining_size = wc->block_size;
do {
struct bio_vec bv = bio_iter_iovec(bio, bio->bi_iter);
buf = bvec_kmap_local(&bv);
size = bv.bv_len;
if (unlikely(size > remaining_size))
size = remaining_size;
if (rw == READ) {
int r;
r = copy_mc_to_kernel(buf, data, size);
flush_dcache_page(bio_page(bio));
if (unlikely(r)) {
writecache_error(wc, r, "hardware memory error when reading data: %d", r);
bio->bi_status = BLK_STS_IOERR;
}
} else {
flush_dcache_page(bio_page(bio));
memcpy_flushcache_optimized(data, buf, size);
}
kunmap_local(buf);
data = (char *)data + size;
remaining_size -= size;
bio_advance(bio, size);
} while (unlikely(remaining_size));
}
static int writecache_flush_thread(void *data)
{
struct dm_writecache *wc = data;
while (1) {
struct bio *bio;
wc_lock(wc);
bio = bio_list_pop(&wc->flush_list);
if (!bio) {
set_current_state(TASK_INTERRUPTIBLE);
wc_unlock(wc);
if (unlikely(kthread_should_stop())) {
set_current_state(TASK_RUNNING);
break;
}
schedule();
continue;
}
if (bio_op(bio) == REQ_OP_DISCARD) {
writecache_discard(wc, bio->bi_iter.bi_sector,
bio_end_sector(bio));
wc_unlock(wc);
bio_set_dev(bio, wc->dev->bdev);
submit_bio_noacct(bio);
} else {
writecache_flush(wc);
wc_unlock(wc);
if (writecache_has_error(wc))
bio->bi_status = BLK_STS_IOERR;
bio_endio(bio);
}
}
return 0;
}
static void writecache_offload_bio(struct dm_writecache *wc, struct bio *bio)
{
if (bio_list_empty(&wc->flush_list))
wake_up_process(wc->flush_thread);
bio_list_add(&wc->flush_list, bio);
}
enum wc_map_op {
WC_MAP_SUBMIT,
WC_MAP_REMAP,
WC_MAP_REMAP_ORIGIN,
WC_MAP_RETURN,
WC_MAP_ERROR,
};
static void writecache_map_remap_origin(struct dm_writecache *wc, struct bio *bio,
struct wc_entry *e)
{
if (e) {
sector_t next_boundary =
read_original_sector(wc, e) - bio->bi_iter.bi_sector;
if (next_boundary < bio->bi_iter.bi_size >> SECTOR_SHIFT)
dm_accept_partial_bio(bio, next_boundary);
}
}
static enum wc_map_op writecache_map_read(struct dm_writecache *wc, struct bio *bio)
{
enum wc_map_op map_op;
struct wc_entry *e;
read_next_block:
wc->stats.reads++;
e = writecache_find_entry(wc, bio->bi_iter.bi_sector, WFE_RETURN_FOLLOWING);
if (e && read_original_sector(wc, e) == bio->bi_iter.bi_sector) {
wc->stats.read_hits++;
if (WC_MODE_PMEM(wc)) {
bio_copy_block(wc, bio, memory_data(wc, e));
if (bio->bi_iter.bi_size)
goto read_next_block;
map_op = WC_MAP_SUBMIT;
} else {
dm_accept_partial_bio(bio, wc->block_size >> SECTOR_SHIFT);
bio_set_dev(bio, wc->ssd_dev->bdev);
bio->bi_iter.bi_sector = cache_sector(wc, e);
if (!writecache_entry_is_committed(wc, e))
writecache_wait_for_ios(wc, WRITE);
map_op = WC_MAP_REMAP;
}
} else {
writecache_map_remap_origin(wc, bio, e);
wc->stats.reads += (bio->bi_iter.bi_size - wc->block_size) >> wc->block_size_bits;
map_op = WC_MAP_REMAP_ORIGIN;
}
return map_op;
}
static void writecache_bio_copy_ssd(struct dm_writecache *wc, struct bio *bio,
struct wc_entry *e, bool search_used)
{
unsigned int bio_size = wc->block_size;
sector_t start_cache_sec = cache_sector(wc, e);
sector_t current_cache_sec = start_cache_sec + (bio_size >> SECTOR_SHIFT);
while (bio_size < bio->bi_iter.bi_size) {
if (!search_used) {
struct wc_entry *f = writecache_pop_from_freelist(wc, current_cache_sec);
if (!f)
break;
write_original_sector_seq_count(wc, f, bio->bi_iter.bi_sector +
(bio_size >> SECTOR_SHIFT), wc->seq_count);
writecache_insert_entry(wc, f);
wc->uncommitted_blocks++;
} else {
struct wc_entry *f;
struct rb_node *next = rb_next(&e->rb_node);
if (!next)
break;
f = container_of(next, struct wc_entry, rb_node);
if (f != e + 1)
break;
if (read_original_sector(wc, f) !=
read_original_sector(wc, e) + (wc->block_size >> SECTOR_SHIFT))
break;
if (unlikely(f->write_in_progress))
break;
if (writecache_entry_is_committed(wc, f))
wc->overwrote_committed = true;
e = f;
}
bio_size += wc->block_size;
current_cache_sec += wc->block_size >> SECTOR_SHIFT;
}
bio_set_dev(bio, wc->ssd_dev->bdev);
bio->bi_iter.bi_sector = start_cache_sec;
dm_accept_partial_bio(bio, bio_size >> SECTOR_SHIFT);
wc->stats.writes += bio->bi_iter.bi_size >> wc->block_size_bits;
wc->stats.writes_allocate += (bio->bi_iter.bi_size - wc->block_size) >> wc->block_size_bits;
if (unlikely(wc->uncommitted_blocks >= wc->autocommit_blocks)) {
wc->uncommitted_blocks = 0;
queue_work(wc->writeback_wq, &wc->flush_work);
} else {
writecache_schedule_autocommit(wc);
}
}
static enum wc_map_op writecache_map_write(struct dm_writecache *wc, struct bio *bio)
{
struct wc_entry *e;
do {
bool found_entry = false;
bool search_used = false;
if (writecache_has_error(wc)) {
wc->stats.writes += bio->bi_iter.bi_size >> wc->block_size_bits;
return WC_MAP_ERROR;
}
e = writecache_find_entry(wc, bio->bi_iter.bi_sector, 0);
if (e) {
if (!writecache_entry_is_committed(wc, e)) {
wc->stats.write_hits_uncommitted++;
search_used = true;
goto bio_copy;
}
wc->stats.write_hits_committed++;
if (!WC_MODE_PMEM(wc) && !e->write_in_progress) {
wc->overwrote_committed = true;
search_used = true;
goto bio_copy;
}
found_entry = true;
} else {
if (unlikely(wc->cleaner) ||
(wc->metadata_only && !(bio->bi_opf & REQ_META)))
goto direct_write;
}
e = writecache_pop_from_freelist(wc, (sector_t)-1);
if (unlikely(!e)) {
if (!WC_MODE_PMEM(wc) && !found_entry) {
direct_write:
e = writecache_find_entry(wc, bio->bi_iter.bi_sector, WFE_RETURN_FOLLOWING);
writecache_map_remap_origin(wc, bio, e);
wc->stats.writes_around += bio->bi_iter.bi_size >> wc->block_size_bits;
wc->stats.writes += bio->bi_iter.bi_size >> wc->block_size_bits;
return WC_MAP_REMAP_ORIGIN;
}
wc->stats.writes_blocked_on_freelist++;
writecache_wait_on_freelist(wc);
continue;
}
write_original_sector_seq_count(wc, e, bio->bi_iter.bi_sector, wc->seq_count);
writecache_insert_entry(wc, e);
wc->uncommitted_blocks++;
wc->stats.writes_allocate++;
bio_copy:
if (WC_MODE_PMEM(wc)) {
bio_copy_block(wc, bio, memory_data(wc, e));
wc->stats.writes++;
} else {
writecache_bio_copy_ssd(wc, bio, e, search_used);
return WC_MAP_REMAP;
}
} while (bio->bi_iter.bi_size);
if (unlikely(bio->bi_opf & REQ_FUA || wc->uncommitted_blocks >= wc->autocommit_blocks))
writecache_flush(wc);
else
writecache_schedule_autocommit(wc);
return WC_MAP_SUBMIT;
}
static enum wc_map_op writecache_map_flush(struct dm_writecache *wc, struct bio *bio)
{
if (writecache_has_error(wc))
return WC_MAP_ERROR;
if (WC_MODE_PMEM(wc)) {
wc->stats.flushes++;
writecache_flush(wc);
if (writecache_has_error(wc))
return WC_MAP_ERROR;
else if (unlikely(wc->cleaner) || unlikely(wc->metadata_only))
return WC_MAP_REMAP_ORIGIN;
return WC_MAP_SUBMIT;
}
/* SSD: */
if (dm_bio_get_target_bio_nr(bio))
return WC_MAP_REMAP_ORIGIN;
wc->stats.flushes++;
writecache_offload_bio(wc, bio);
return WC_MAP_RETURN;
}
static enum wc_map_op writecache_map_discard(struct dm_writecache *wc, struct bio *bio)
{
wc->stats.discards += bio->bi_iter.bi_size >> wc->block_size_bits;
if (writecache_has_error(wc))
return WC_MAP_ERROR;
if (WC_MODE_PMEM(wc)) {
writecache_discard(wc, bio->bi_iter.bi_sector, bio_end_sector(bio));
return WC_MAP_REMAP_ORIGIN;
}
/* SSD: */
writecache_offload_bio(wc, bio);
return WC_MAP_RETURN;
}
static int writecache_map(struct dm_target *ti, struct bio *bio)
{
struct dm_writecache *wc = ti->private;
enum wc_map_op map_op;
bio->bi_private = NULL;
wc_lock(wc);
if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
map_op = writecache_map_flush(wc, bio);
goto done;
}
bio->bi_iter.bi_sector = dm_target_offset(ti, bio->bi_iter.bi_sector);
if (unlikely((((unsigned int)bio->bi_iter.bi_sector | bio_sectors(bio)) &
(wc->block_size / 512 - 1)) != 0)) {
DMERR("I/O is not aligned, sector %llu, size %u, block size %u",
(unsigned long long)bio->bi_iter.bi_sector,
bio->bi_iter.bi_size, wc->block_size);
map_op = WC_MAP_ERROR;
goto done;
}
if (unlikely(bio_op(bio) == REQ_OP_DISCARD)) {
map_op = writecache_map_discard(wc, bio);
goto done;
}
if (bio_data_dir(bio) == READ)
map_op = writecache_map_read(wc, bio);
else
map_op = writecache_map_write(wc, bio);
done:
switch (map_op) {
case WC_MAP_REMAP_ORIGIN:
if (likely(wc->pause != 0)) {
if (bio_op(bio) == REQ_OP_WRITE) {
dm_iot_io_begin(&wc->iot, 1);
bio->bi_private = (void *)2;
}
}
bio_set_dev(bio, wc->dev->bdev);
wc_unlock(wc);
return DM_MAPIO_REMAPPED;
case WC_MAP_REMAP:
/* make sure that writecache_end_io decrements bio_in_progress: */
bio->bi_private = (void *)1;
atomic_inc(&wc->bio_in_progress[bio_data_dir(bio)]);
wc_unlock(wc);
return DM_MAPIO_REMAPPED;
case WC_MAP_SUBMIT:
wc_unlock(wc);
bio_endio(bio);
return DM_MAPIO_SUBMITTED;
case WC_MAP_RETURN:
wc_unlock(wc);
return DM_MAPIO_SUBMITTED;
case WC_MAP_ERROR:
wc_unlock(wc);
bio_io_error(bio);
return DM_MAPIO_SUBMITTED;
default:
BUG();
wc_unlock(wc);
return DM_MAPIO_KILL;
}
}
static int writecache_end_io(struct dm_target *ti, struct bio *bio, blk_status_t *status)
{
struct dm_writecache *wc = ti->private;
if (bio->bi_private == (void *)1) {
int dir = bio_data_dir(bio);
if (atomic_dec_and_test(&wc->bio_in_progress[dir]))
if (unlikely(waitqueue_active(&wc->bio_in_progress_wait[dir])))
wake_up(&wc->bio_in_progress_wait[dir]);
} else if (bio->bi_private == (void *)2) {
dm_iot_io_end(&wc->iot, 1);
}
return 0;
}
static int writecache_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct dm_writecache *wc = ti->private;
return fn(ti, wc->dev, 0, ti->len, data);
}
static void writecache_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
struct dm_writecache *wc = ti->private;
if (limits->logical_block_size < wc->block_size)
limits->logical_block_size = wc->block_size;
if (limits->physical_block_size < wc->block_size)
limits->physical_block_size = wc->block_size;
if (limits->io_min < wc->block_size)
limits->io_min = wc->block_size;
}
static void writecache_writeback_endio(struct bio *bio)
{
struct writeback_struct *wb = container_of(bio, struct writeback_struct, bio);
struct dm_writecache *wc = wb->wc;
unsigned long flags;
raw_spin_lock_irqsave(&wc->endio_list_lock, flags);
if (unlikely(list_empty(&wc->endio_list)))
wake_up_process(wc->endio_thread);
list_add_tail(&wb->endio_entry, &wc->endio_list);
raw_spin_unlock_irqrestore(&wc->endio_list_lock, flags);
}
static void writecache_copy_endio(int read_err, unsigned long write_err, void *ptr)
{
struct copy_struct *c = ptr;
struct dm_writecache *wc = c->wc;
c->error = likely(!(read_err | write_err)) ? 0 : -EIO;
raw_spin_lock_irq(&wc->endio_list_lock);
if (unlikely(list_empty(&wc->endio_list)))
wake_up_process(wc->endio_thread);
list_add_tail(&c->endio_entry, &wc->endio_list);
raw_spin_unlock_irq(&wc->endio_list_lock);
}
static void __writecache_endio_pmem(struct dm_writecache *wc, struct list_head *list)
{
unsigned int i;
struct writeback_struct *wb;
struct wc_entry *e;
unsigned long n_walked = 0;
do {
wb = list_entry(list->next, struct writeback_struct, endio_entry);
list_del(&wb->endio_entry);
if (unlikely(wb->bio.bi_status != BLK_STS_OK))
writecache_error(wc, blk_status_to_errno(wb->bio.bi_status),
"write error %d", wb->bio.bi_status);
i = 0;
do {
e = wb->wc_list[i];
BUG_ON(!e->write_in_progress);
e->write_in_progress = false;
INIT_LIST_HEAD(&e->lru);
if (!writecache_has_error(wc))
writecache_free_entry(wc, e);
BUG_ON(!wc->writeback_size);
wc->writeback_size--;
n_walked++;
if (unlikely(n_walked >= ENDIO_LATENCY)) {
writecache_commit_flushed(wc, false);
wc_unlock(wc);
wc_lock(wc);
n_walked = 0;
}
} while (++i < wb->wc_list_n);
if (wb->wc_list != wb->wc_list_inline)
kfree(wb->wc_list);
bio_put(&wb->bio);
} while (!list_empty(list));
}
static void __writecache_endio_ssd(struct dm_writecache *wc, struct list_head *list)
{
struct copy_struct *c;
struct wc_entry *e;
do {
c = list_entry(list->next, struct copy_struct, endio_entry);
list_del(&c->endio_entry);
if (unlikely(c->error))
writecache_error(wc, c->error, "copy error");
e = c->e;
do {
BUG_ON(!e->write_in_progress);
e->write_in_progress = false;
INIT_LIST_HEAD(&e->lru);
if (!writecache_has_error(wc))
writecache_free_entry(wc, e);
BUG_ON(!wc->writeback_size);
wc->writeback_size--;
e++;
} while (--c->n_entries);
mempool_free(c, &wc->copy_pool);
} while (!list_empty(list));
}
static int writecache_endio_thread(void *data)
{
struct dm_writecache *wc = data;
while (1) {
struct list_head list;
raw_spin_lock_irq(&wc->endio_list_lock);
if (!list_empty(&wc->endio_list))
goto pop_from_list;
set_current_state(TASK_INTERRUPTIBLE);
raw_spin_unlock_irq(&wc->endio_list_lock);
if (unlikely(kthread_should_stop())) {
set_current_state(TASK_RUNNING);
break;
}
schedule();
continue;
pop_from_list:
list = wc->endio_list;
list.next->prev = list.prev->next = &list;
INIT_LIST_HEAD(&wc->endio_list);
raw_spin_unlock_irq(&wc->endio_list_lock);
if (!WC_MODE_FUA(wc))
writecache_disk_flush(wc, wc->dev);
wc_lock(wc);
if (WC_MODE_PMEM(wc)) {
__writecache_endio_pmem(wc, &list);
} else {
__writecache_endio_ssd(wc, &list);
writecache_wait_for_ios(wc, READ);
}
writecache_commit_flushed(wc, false);
wc_unlock(wc);
}
return 0;
}
static bool wc_add_block(struct writeback_struct *wb, struct wc_entry *e)
{
struct dm_writecache *wc = wb->wc;
unsigned int block_size = wc->block_size;
void *address = memory_data(wc, e);
persistent_memory_flush_cache(address, block_size);
if (unlikely(bio_end_sector(&wb->bio) >= wc->data_device_sectors))
return true;
return bio_add_page(&wb->bio, persistent_memory_page(address),
block_size, persistent_memory_page_offset(address)) != 0;
}
struct writeback_list {
struct list_head list;
size_t size;
};
static void __writeback_throttle(struct dm_writecache *wc, struct writeback_list *wbl)
{
if (unlikely(wc->max_writeback_jobs)) {
if (READ_ONCE(wc->writeback_size) - wbl->size >= wc->max_writeback_jobs) {
wc_lock(wc);
while (wc->writeback_size - wbl->size >= wc->max_writeback_jobs)
writecache_wait_on_freelist(wc);
wc_unlock(wc);
}
}
cond_resched();
}
static void __writecache_writeback_pmem(struct dm_writecache *wc, struct writeback_list *wbl)
{
struct wc_entry *e, *f;
struct bio *bio;
struct writeback_struct *wb;
unsigned int max_pages;
while (wbl->size) {
wbl->size--;
e = container_of(wbl->list.prev, struct wc_entry, lru);
list_del(&e->lru);
max_pages = e->wc_list_contiguous;
bio = bio_alloc_bioset(wc->dev->bdev, max_pages, REQ_OP_WRITE,
GFP_NOIO, &wc->bio_set);
wb = container_of(bio, struct writeback_struct, bio);
wb->wc = wc;
bio->bi_end_io = writecache_writeback_endio;
bio->bi_iter.bi_sector = read_original_sector(wc, e);
if (unlikely(max_pages > WB_LIST_INLINE))
wb->wc_list = kmalloc_array(max_pages, sizeof(struct wc_entry *),
GFP_NOIO | __GFP_NORETRY |
__GFP_NOMEMALLOC | __GFP_NOWARN);
if (likely(max_pages <= WB_LIST_INLINE) || unlikely(!wb->wc_list)) {
wb->wc_list = wb->wc_list_inline;
max_pages = WB_LIST_INLINE;
}
BUG_ON(!wc_add_block(wb, e));
wb->wc_list[0] = e;
wb->wc_list_n = 1;
while (wbl->size && wb->wc_list_n < max_pages) {
f = container_of(wbl->list.prev, struct wc_entry, lru);
if (read_original_sector(wc, f) !=
read_original_sector(wc, e) + (wc->block_size >> SECTOR_SHIFT))
break;
if (!wc_add_block(wb, f))
break;
wbl->size--;
list_del(&f->lru);
wb->wc_list[wb->wc_list_n++] = f;
e = f;
}
if (WC_MODE_FUA(wc))
bio->bi_opf |= REQ_FUA;
if (writecache_has_error(wc)) {
bio->bi_status = BLK_STS_IOERR;
bio_endio(bio);
} else if (unlikely(!bio_sectors(bio))) {
bio->bi_status = BLK_STS_OK;
bio_endio(bio);
} else {
submit_bio(bio);
}
__writeback_throttle(wc, wbl);
}
}
static void __writecache_writeback_ssd(struct dm_writecache *wc, struct writeback_list *wbl)
{
struct wc_entry *e, *f;
struct dm_io_region from, to;
struct copy_struct *c;
while (wbl->size) {
unsigned int n_sectors;
wbl->size--;
e = container_of(wbl->list.prev, struct wc_entry, lru);
list_del(&e->lru);
n_sectors = e->wc_list_contiguous << (wc->block_size_bits - SECTOR_SHIFT);
from.bdev = wc->ssd_dev->bdev;
from.sector = cache_sector(wc, e);
from.count = n_sectors;
to.bdev = wc->dev->bdev;
to.sector = read_original_sector(wc, e);
to.count = n_sectors;
c = mempool_alloc(&wc->copy_pool, GFP_NOIO);
c->wc = wc;
c->e = e;
c->n_entries = e->wc_list_contiguous;
while ((n_sectors -= wc->block_size >> SECTOR_SHIFT)) {
wbl->size--;
f = container_of(wbl->list.prev, struct wc_entry, lru);
BUG_ON(f != e + 1);
list_del(&f->lru);
e = f;
}
if (unlikely(to.sector + to.count > wc->data_device_sectors)) {
if (to.sector >= wc->data_device_sectors) {
writecache_copy_endio(0, 0, c);
continue;
}
from.count = to.count = wc->data_device_sectors - to.sector;
}
dm_kcopyd_copy(wc->dm_kcopyd, &from, 1, &to, 0, writecache_copy_endio, c);
__writeback_throttle(wc, wbl);
}
}
static void writecache_writeback(struct work_struct *work)
{
struct dm_writecache *wc = container_of(work, struct dm_writecache, writeback_work);
struct blk_plug plug;
struct wc_entry *f, *g, *e = NULL;
struct rb_node *node, *next_node;
struct list_head skipped;
struct writeback_list wbl;
unsigned long n_walked;
if (!WC_MODE_PMEM(wc)) {
/* Wait for any active kcopyd work on behalf of ssd writeback */
dm_kcopyd_client_flush(wc->dm_kcopyd);
}
if (likely(wc->pause != 0)) {
while (1) {
unsigned long idle;
if (unlikely(wc->cleaner) || unlikely(wc->writeback_all) ||
unlikely(dm_suspended(wc->ti)))
break;
idle = dm_iot_idle_time(&wc->iot);
if (idle >= wc->pause)
break;
idle = wc->pause - idle;
if (idle > HZ)
idle = HZ;
schedule_timeout_idle(idle);
}
}
wc_lock(wc);
restart:
if (writecache_has_error(wc)) {
wc_unlock(wc);
return;
}
if (unlikely(wc->writeback_all)) {
if (writecache_wait_for_writeback(wc))
goto restart;
}
if (wc->overwrote_committed)
writecache_wait_for_ios(wc, WRITE);
n_walked = 0;
INIT_LIST_HEAD(&skipped);
INIT_LIST_HEAD(&wbl.list);
wbl.size = 0;
while (!list_empty(&wc->lru) &&
(wc->writeback_all ||
wc->freelist_size + wc->writeback_size <= wc->freelist_low_watermark ||
(jiffies - container_of(wc->lru.prev, struct wc_entry, lru)->age >=
wc->max_age - wc->max_age / MAX_AGE_DIV))) {
n_walked++;
if (unlikely(n_walked > WRITEBACK_LATENCY) &&
likely(!wc->writeback_all)) {
if (likely(!dm_suspended(wc->ti)))
queue_work(wc->writeback_wq, &wc->writeback_work);
break;
}
if (unlikely(wc->writeback_all)) {
if (unlikely(!e)) {
writecache_flush(wc);
e = container_of(rb_first(&wc->tree), struct wc_entry, rb_node);
} else
e = g;
} else
e = container_of(wc->lru.prev, struct wc_entry, lru);
BUG_ON(e->write_in_progress);
if (unlikely(!writecache_entry_is_committed(wc, e)))
writecache_flush(wc);
node = rb_prev(&e->rb_node);
if (node) {
f = container_of(node, struct wc_entry, rb_node);
if (unlikely(read_original_sector(wc, f) ==
read_original_sector(wc, e))) {
BUG_ON(!f->write_in_progress);
list_move(&e->lru, &skipped);
cond_resched();
continue;
}
}
wc->writeback_size++;
list_move(&e->lru, &wbl.list);
wbl.size++;
e->write_in_progress = true;
e->wc_list_contiguous = 1;
f = e;
while (1) {
next_node = rb_next(&f->rb_node);
if (unlikely(!next_node))
break;
g = container_of(next_node, struct wc_entry, rb_node);
if (unlikely(read_original_sector(wc, g) ==
read_original_sector(wc, f))) {
f = g;
continue;
}
if (read_original_sector(wc, g) !=
read_original_sector(wc, f) + (wc->block_size >> SECTOR_SHIFT))
break;
if (unlikely(g->write_in_progress))
break;
if (unlikely(!writecache_entry_is_committed(wc, g)))
break;
if (!WC_MODE_PMEM(wc)) {
if (g != f + 1)
break;
}
n_walked++;
//if (unlikely(n_walked > WRITEBACK_LATENCY) && likely(!wc->writeback_all))
// break;
wc->writeback_size++;
list_move(&g->lru, &wbl.list);
wbl.size++;
g->write_in_progress = true;
g->wc_list_contiguous = BIO_MAX_VECS;
f = g;
e->wc_list_contiguous++;
if (unlikely(e->wc_list_contiguous == BIO_MAX_VECS)) {
if (unlikely(wc->writeback_all)) {
next_node = rb_next(&f->rb_node);
if (likely(next_node))
g = container_of(next_node, struct wc_entry, rb_node);
}
break;
}
}
cond_resched();
}
if (!list_empty(&skipped)) {
list_splice_tail(&skipped, &wc->lru);
/*
* If we didn't do any progress, we must wait until some
* writeback finishes to avoid burning CPU in a loop
*/
if (unlikely(!wbl.size))
writecache_wait_for_writeback(wc);
}
wc_unlock(wc);
blk_start_plug(&plug);
if (WC_MODE_PMEM(wc))
__writecache_writeback_pmem(wc, &wbl);
else
__writecache_writeback_ssd(wc, &wbl);
blk_finish_plug(&plug);
if (unlikely(wc->writeback_all)) {
wc_lock(wc);
while (writecache_wait_for_writeback(wc))
;
wc_unlock(wc);
}
}
static int calculate_memory_size(uint64_t device_size, unsigned int block_size,
size_t *n_blocks_p, size_t *n_metadata_blocks_p)
{
uint64_t n_blocks, offset;
struct wc_entry e;
n_blocks = device_size;
do_div(n_blocks, block_size + sizeof(struct wc_memory_entry));
while (1) {
if (!n_blocks)
return -ENOSPC;
/* Verify the following entries[n_blocks] won't overflow */
if (n_blocks >= ((size_t)-sizeof(struct wc_memory_superblock) /
sizeof(struct wc_memory_entry)))
return -EFBIG;
offset = offsetof(struct wc_memory_superblock, entries[n_blocks]);
offset = (offset + block_size - 1) & ~(uint64_t)(block_size - 1);
if (offset + n_blocks * block_size <= device_size)
break;
n_blocks--;
}
/* check if the bit field overflows */
e.index = n_blocks;
if (e.index != n_blocks)
return -EFBIG;
if (n_blocks_p)
*n_blocks_p = n_blocks;
if (n_metadata_blocks_p)
*n_metadata_blocks_p = offset >> __ffs(block_size);
return 0;
}
static int init_memory(struct dm_writecache *wc)
{
size_t b;
int r;
r = calculate_memory_size(wc->memory_map_size, wc->block_size, &wc->n_blocks, NULL);
if (r)
return r;
r = writecache_alloc_entries(wc);
if (r)
return r;
for (b = 0; b < ARRAY_SIZE(sb(wc)->padding); b++)
pmem_assign(sb(wc)->padding[b], cpu_to_le64(0));
pmem_assign(sb(wc)->version, cpu_to_le32(MEMORY_SUPERBLOCK_VERSION));
pmem_assign(sb(wc)->block_size, cpu_to_le32(wc->block_size));
pmem_assign(sb(wc)->n_blocks, cpu_to_le64(wc->n_blocks));
pmem_assign(sb(wc)->seq_count, cpu_to_le64(0));
for (b = 0; b < wc->n_blocks; b++) {
write_original_sector_seq_count(wc, &wc->entries[b], -1, -1);
cond_resched();
}
writecache_flush_all_metadata(wc);
writecache_commit_flushed(wc, false);
pmem_assign(sb(wc)->magic, cpu_to_le32(MEMORY_SUPERBLOCK_MAGIC));
writecache_flush_region(wc, &sb(wc)->magic, sizeof(sb(wc)->magic));
writecache_commit_flushed(wc, false);
return 0;
}
static void writecache_dtr(struct dm_target *ti)
{
struct dm_writecache *wc = ti->private;
if (!wc)
return;
if (wc->endio_thread)
kthread_stop(wc->endio_thread);
if (wc->flush_thread)
kthread_stop(wc->flush_thread);
bioset_exit(&wc->bio_set);
mempool_exit(&wc->copy_pool);
if (wc->writeback_wq)
destroy_workqueue(wc->writeback_wq);
if (wc->dev)
dm_put_device(ti, wc->dev);
if (wc->ssd_dev)
dm_put_device(ti, wc->ssd_dev);
vfree(wc->entries);
if (wc->memory_map) {
if (WC_MODE_PMEM(wc))
persistent_memory_release(wc);
else
vfree(wc->memory_map);
}
if (wc->dm_kcopyd)
dm_kcopyd_client_destroy(wc->dm_kcopyd);
if (wc->dm_io)
dm_io_client_destroy(wc->dm_io);
vfree(wc->dirty_bitmap);
kfree(wc);
}
static int writecache_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
struct dm_writecache *wc;
struct dm_arg_set as;
const char *string;
unsigned int opt_params;
size_t offset, data_size;
int i, r;
char dummy;
int high_wm_percent = HIGH_WATERMARK;
int low_wm_percent = LOW_WATERMARK;
uint64_t x;
struct wc_memory_superblock s;
static struct dm_arg _args[] = {
{0, 18, "Invalid number of feature args"},
};
as.argc = argc;
as.argv = argv;
wc = kzalloc(sizeof(struct dm_writecache), GFP_KERNEL);
if (!wc) {
ti->error = "Cannot allocate writecache structure";
r = -ENOMEM;
goto bad;
}
ti->private = wc;
wc->ti = ti;
mutex_init(&wc->lock);
wc->max_age = MAX_AGE_UNSPECIFIED;
writecache_poison_lists(wc);
init_waitqueue_head(&wc->freelist_wait);
timer_setup(&wc->autocommit_timer, writecache_autocommit_timer, 0);
timer_setup(&wc->max_age_timer, writecache_max_age_timer, 0);
for (i = 0; i < 2; i++) {
atomic_set(&wc->bio_in_progress[i], 0);
init_waitqueue_head(&wc->bio_in_progress_wait[i]);
}
wc->dm_io = dm_io_client_create();
if (IS_ERR(wc->dm_io)) {
r = PTR_ERR(wc->dm_io);
ti->error = "Unable to allocate dm-io client";
wc->dm_io = NULL;
goto bad;
}
wc->writeback_wq = alloc_workqueue("writecache-writeback", WQ_MEM_RECLAIM, 1);
if (!wc->writeback_wq) {
r = -ENOMEM;
ti->error = "Could not allocate writeback workqueue";
goto bad;
}
INIT_WORK(&wc->writeback_work, writecache_writeback);
INIT_WORK(&wc->flush_work, writecache_flush_work);
dm_iot_init(&wc->iot);
raw_spin_lock_init(&wc->endio_list_lock);
INIT_LIST_HEAD(&wc->endio_list);
wc->endio_thread = kthread_run(writecache_endio_thread, wc, "writecache_endio");
if (IS_ERR(wc->endio_thread)) {
r = PTR_ERR(wc->endio_thread);
wc->endio_thread = NULL;
ti->error = "Couldn't spawn endio thread";
goto bad;
}
/*
* Parse the mode (pmem or ssd)
*/
string = dm_shift_arg(&as);
if (!string)
goto bad_arguments;
if (!strcasecmp(string, "s")) {
wc->pmem_mode = false;
} else if (!strcasecmp(string, "p")) {
#ifdef DM_WRITECACHE_HAS_PMEM
wc->pmem_mode = true;
wc->writeback_fua = true;
#else
/*
* If the architecture doesn't support persistent memory or
* the kernel doesn't support any DAX drivers, this driver can
* only be used in SSD-only mode.
*/
r = -EOPNOTSUPP;
ti->error = "Persistent memory or DAX not supported on this system";
goto bad;
#endif
} else {
goto bad_arguments;
}
if (WC_MODE_PMEM(wc)) {
r = bioset_init(&wc->bio_set, BIO_POOL_SIZE,
offsetof(struct writeback_struct, bio),
BIOSET_NEED_BVECS);
if (r) {
ti->error = "Could not allocate bio set";
goto bad;
}
} else {
wc->pause = PAUSE_WRITEBACK;
r = mempool_init_kmalloc_pool(&wc->copy_pool, 1, sizeof(struct copy_struct));
if (r) {
ti->error = "Could not allocate mempool";
goto bad;
}
}
/*
* Parse the origin data device
*/
string = dm_shift_arg(&as);
if (!string)
goto bad_arguments;
r = dm_get_device(ti, string, dm_table_get_mode(ti->table), &wc->dev);
if (r) {
ti->error = "Origin data device lookup failed";
goto bad;
}
/*
* Parse cache data device (be it pmem or ssd)
*/
string = dm_shift_arg(&as);
if (!string)
goto bad_arguments;
r = dm_get_device(ti, string, dm_table_get_mode(ti->table), &wc->ssd_dev);
if (r) {
ti->error = "Cache data device lookup failed";
goto bad;
}
wc->memory_map_size = bdev_nr_bytes(wc->ssd_dev->bdev);
/*
* Parse the cache block size
*/
string = dm_shift_arg(&as);
if (!string)
goto bad_arguments;
if (sscanf(string, "%u%c", &wc->block_size, &dummy) != 1 ||
wc->block_size < 512 || wc->block_size > PAGE_SIZE ||
(wc->block_size & (wc->block_size - 1))) {
r = -EINVAL;
ti->error = "Invalid block size";
goto bad;
}
if (wc->block_size < bdev_logical_block_size(wc->dev->bdev) ||
wc->block_size < bdev_logical_block_size(wc->ssd_dev->bdev)) {
r = -EINVAL;
ti->error = "Block size is smaller than device logical block size";
goto bad;
}
wc->block_size_bits = __ffs(wc->block_size);
wc->max_writeback_jobs = MAX_WRITEBACK_JOBS;
wc->autocommit_blocks = !WC_MODE_PMEM(wc) ? AUTOCOMMIT_BLOCKS_SSD : AUTOCOMMIT_BLOCKS_PMEM;
wc->autocommit_jiffies = msecs_to_jiffies(AUTOCOMMIT_MSEC);
/*
* Parse optional arguments
*/
r = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
if (r)
goto bad;
while (opt_params) {
string = dm_shift_arg(&as), opt_params--;
if (!strcasecmp(string, "start_sector") && opt_params >= 1) {
unsigned long long start_sector;
string = dm_shift_arg(&as), opt_params--;
if (sscanf(string, "%llu%c", &start_sector, &dummy) != 1)
goto invalid_optional;
wc->start_sector = start_sector;
wc->start_sector_set = true;
if (wc->start_sector != start_sector ||
wc->start_sector >= wc->memory_map_size >> SECTOR_SHIFT)
goto invalid_optional;
} else if (!strcasecmp(string, "high_watermark") && opt_params >= 1) {
string = dm_shift_arg(&as), opt_params--;
if (sscanf(string, "%d%c", &high_wm_percent, &dummy) != 1)
goto invalid_optional;
if (high_wm_percent < 0 || high_wm_percent > 100)
goto invalid_optional;
wc->high_wm_percent_value = high_wm_percent;
wc->high_wm_percent_set = true;
} else if (!strcasecmp(string, "low_watermark") && opt_params >= 1) {
string = dm_shift_arg(&as), opt_params--;
if (sscanf(string, "%d%c", &low_wm_percent, &dummy) != 1)
goto invalid_optional;
if (low_wm_percent < 0 || low_wm_percent > 100)
goto invalid_optional;
wc->low_wm_percent_value = low_wm_percent;
wc->low_wm_percent_set = true;
} else if (!strcasecmp(string, "writeback_jobs") && opt_params >= 1) {
string = dm_shift_arg(&as), opt_params--;
if (sscanf(string, "%u%c", &wc->max_writeback_jobs, &dummy) != 1)
goto invalid_optional;
wc->max_writeback_jobs_set = true;
} else if (!strcasecmp(string, "autocommit_blocks") && opt_params >= 1) {
string = dm_shift_arg(&as), opt_params--;
if (sscanf(string, "%u%c", &wc->autocommit_blocks, &dummy) != 1)
goto invalid_optional;
wc->autocommit_blocks_set = true;
} else if (!strcasecmp(string, "autocommit_time") && opt_params >= 1) {
unsigned int autocommit_msecs;
string = dm_shift_arg(&as), opt_params--;
if (sscanf(string, "%u%c", &autocommit_msecs, &dummy) != 1)
goto invalid_optional;
if (autocommit_msecs > 3600000)
goto invalid_optional;
wc->autocommit_jiffies = msecs_to_jiffies(autocommit_msecs);
wc->autocommit_time_value = autocommit_msecs;
wc->autocommit_time_set = true;
} else if (!strcasecmp(string, "max_age") && opt_params >= 1) {
unsigned int max_age_msecs;
string = dm_shift_arg(&as), opt_params--;
if (sscanf(string, "%u%c", &max_age_msecs, &dummy) != 1)
goto invalid_optional;
if (max_age_msecs > 86400000)
goto invalid_optional;
wc->max_age = msecs_to_jiffies(max_age_msecs);
wc->max_age_set = true;
wc->max_age_value = max_age_msecs;
} else if (!strcasecmp(string, "cleaner")) {
wc->cleaner_set = true;
wc->cleaner = true;
} else if (!strcasecmp(string, "fua")) {
if (WC_MODE_PMEM(wc)) {
wc->writeback_fua = true;
wc->writeback_fua_set = true;
} else
goto invalid_optional;
} else if (!strcasecmp(string, "nofua")) {
if (WC_MODE_PMEM(wc)) {
wc->writeback_fua = false;
wc->writeback_fua_set = true;
} else
goto invalid_optional;
} else if (!strcasecmp(string, "metadata_only")) {
wc->metadata_only = true;
} else if (!strcasecmp(string, "pause_writeback") && opt_params >= 1) {
unsigned int pause_msecs;
if (WC_MODE_PMEM(wc))
goto invalid_optional;
string = dm_shift_arg(&as), opt_params--;
if (sscanf(string, "%u%c", &pause_msecs, &dummy) != 1)
goto invalid_optional;
if (pause_msecs > 60000)
goto invalid_optional;
wc->pause = msecs_to_jiffies(pause_msecs);
wc->pause_set = true;
wc->pause_value = pause_msecs;
} else {
invalid_optional:
r = -EINVAL;
ti->error = "Invalid optional argument";
goto bad;
}
}
if (high_wm_percent < low_wm_percent) {
r = -EINVAL;
ti->error = "High watermark must be greater than or equal to low watermark";
goto bad;
}
if (WC_MODE_PMEM(wc)) {
if (!dax_synchronous(wc->ssd_dev->dax_dev)) {
r = -EOPNOTSUPP;
ti->error = "Asynchronous persistent memory not supported as pmem cache";
goto bad;
}
r = persistent_memory_claim(wc);
if (r) {
ti->error = "Unable to map persistent memory for cache";
goto bad;
}
} else {
size_t n_blocks, n_metadata_blocks;
uint64_t n_bitmap_bits;
wc->memory_map_size -= (uint64_t)wc->start_sector << SECTOR_SHIFT;
bio_list_init(&wc->flush_list);
wc->flush_thread = kthread_run(writecache_flush_thread, wc, "dm_writecache_flush");
if (IS_ERR(wc->flush_thread)) {
r = PTR_ERR(wc->flush_thread);
wc->flush_thread = NULL;
ti->error = "Couldn't spawn flush thread";
goto bad;
}
r = calculate_memory_size(wc->memory_map_size, wc->block_size,
&n_blocks, &n_metadata_blocks);
if (r) {
ti->error = "Invalid device size";
goto bad;
}
n_bitmap_bits = (((uint64_t)n_metadata_blocks << wc->block_size_bits) +
BITMAP_GRANULARITY - 1) / BITMAP_GRANULARITY;
/* this is limitation of test_bit functions */
if (n_bitmap_bits > 1U << 31) {
r = -EFBIG;
ti->error = "Invalid device size";
goto bad;
}
wc->memory_map = vmalloc(n_metadata_blocks << wc->block_size_bits);
if (!wc->memory_map) {
r = -ENOMEM;
ti->error = "Unable to allocate memory for metadata";
goto bad;
}
wc->dm_kcopyd = dm_kcopyd_client_create(&dm_kcopyd_throttle);
if (IS_ERR(wc->dm_kcopyd)) {
r = PTR_ERR(wc->dm_kcopyd);
ti->error = "Unable to allocate dm-kcopyd client";
wc->dm_kcopyd = NULL;
goto bad;
}
wc->metadata_sectors = n_metadata_blocks << (wc->block_size_bits - SECTOR_SHIFT);
wc->dirty_bitmap_size = (n_bitmap_bits + BITS_PER_LONG - 1) /
BITS_PER_LONG * sizeof(unsigned long);
wc->dirty_bitmap = vzalloc(wc->dirty_bitmap_size);
if (!wc->dirty_bitmap) {
r = -ENOMEM;
ti->error = "Unable to allocate dirty bitmap";
goto bad;
}
r = writecache_read_metadata(wc, wc->block_size >> SECTOR_SHIFT);
if (r) {
ti->error = "Unable to read first block of metadata";
goto bad;
}
}
r = copy_mc_to_kernel(&s, sb(wc), sizeof(struct wc_memory_superblock));
if (r) {
ti->error = "Hardware memory error when reading superblock";
goto bad;
}
if (!le32_to_cpu(s.magic) && !le32_to_cpu(s.version)) {
r = init_memory(wc);
if (r) {
ti->error = "Unable to initialize device";
goto bad;
}
r = copy_mc_to_kernel(&s, sb(wc),
sizeof(struct wc_memory_superblock));
if (r) {
ti->error = "Hardware memory error when reading superblock";
goto bad;
}
}
if (le32_to_cpu(s.magic) != MEMORY_SUPERBLOCK_MAGIC) {
ti->error = "Invalid magic in the superblock";
r = -EINVAL;
goto bad;
}
if (le32_to_cpu(s.version) != MEMORY_SUPERBLOCK_VERSION) {
ti->error = "Invalid version in the superblock";
r = -EINVAL;
goto bad;
}
if (le32_to_cpu(s.block_size) != wc->block_size) {
ti->error = "Block size does not match superblock";
r = -EINVAL;
goto bad;
}
wc->n_blocks = le64_to_cpu(s.n_blocks);
offset = wc->n_blocks * sizeof(struct wc_memory_entry);
if (offset / sizeof(struct wc_memory_entry) != le64_to_cpu(sb(wc)->n_blocks)) {
overflow:
ti->error = "Overflow in size calculation";
r = -EINVAL;
goto bad;
}
offset += sizeof(struct wc_memory_superblock);
if (offset < sizeof(struct wc_memory_superblock))
goto overflow;
offset = (offset + wc->block_size - 1) & ~(size_t)(wc->block_size - 1);
data_size = wc->n_blocks * (size_t)wc->block_size;
if (!offset || (data_size / wc->block_size != wc->n_blocks) ||
(offset + data_size < offset))
goto overflow;
if (offset + data_size > wc->memory_map_size) {
ti->error = "Memory area is too small";
r = -EINVAL;
goto bad;
}
wc->metadata_sectors = offset >> SECTOR_SHIFT;
wc->block_start = (char *)sb(wc) + offset;
x = (uint64_t)wc->n_blocks * (100 - high_wm_percent);
x += 50;
do_div(x, 100);
wc->freelist_high_watermark = x;
x = (uint64_t)wc->n_blocks * (100 - low_wm_percent);
x += 50;
do_div(x, 100);
wc->freelist_low_watermark = x;
if (wc->cleaner)
activate_cleaner(wc);
r = writecache_alloc_entries(wc);
if (r) {
ti->error = "Cannot allocate memory";
goto bad;
}
ti->num_flush_bios = WC_MODE_PMEM(wc) ? 1 : 2;
ti->flush_supported = true;
ti->num_discard_bios = 1;
if (WC_MODE_PMEM(wc))
persistent_memory_flush_cache(wc->memory_map, wc->memory_map_size);
return 0;
bad_arguments:
r = -EINVAL;
ti->error = "Bad arguments";
bad:
writecache_dtr(ti);
return r;
}
static void writecache_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
struct dm_writecache *wc = ti->private;
unsigned int extra_args;
unsigned int sz = 0;
switch (type) {
case STATUSTYPE_INFO:
DMEMIT("%ld %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu",
writecache_has_error(wc),
(unsigned long long)wc->n_blocks, (unsigned long long)wc->freelist_size,
(unsigned long long)wc->writeback_size,
wc->stats.reads,
wc->stats.read_hits,
wc->stats.writes,
wc->stats.write_hits_uncommitted,
wc->stats.write_hits_committed,
wc->stats.writes_around,
wc->stats.writes_allocate,
wc->stats.writes_blocked_on_freelist,
wc->stats.flushes,
wc->stats.discards);
break;
case STATUSTYPE_TABLE:
DMEMIT("%c %s %s %u ", WC_MODE_PMEM(wc) ? 'p' : 's',
wc->dev->name, wc->ssd_dev->name, wc->block_size);
extra_args = 0;
if (wc->start_sector_set)
extra_args += 2;
if (wc->high_wm_percent_set)
extra_args += 2;
if (wc->low_wm_percent_set)
extra_args += 2;
if (wc->max_writeback_jobs_set)
extra_args += 2;
if (wc->autocommit_blocks_set)
extra_args += 2;
if (wc->autocommit_time_set)
extra_args += 2;
if (wc->max_age_set)
extra_args += 2;
if (wc->cleaner_set)
extra_args++;
if (wc->writeback_fua_set)
extra_args++;
if (wc->metadata_only)
extra_args++;
if (wc->pause_set)
extra_args += 2;
DMEMIT("%u", extra_args);
if (wc->start_sector_set)
DMEMIT(" start_sector %llu", (unsigned long long)wc->start_sector);
if (wc->high_wm_percent_set)
DMEMIT(" high_watermark %u", wc->high_wm_percent_value);
if (wc->low_wm_percent_set)
DMEMIT(" low_watermark %u", wc->low_wm_percent_value);
if (wc->max_writeback_jobs_set)
DMEMIT(" writeback_jobs %u", wc->max_writeback_jobs);
if (wc->autocommit_blocks_set)
DMEMIT(" autocommit_blocks %u", wc->autocommit_blocks);
if (wc->autocommit_time_set)
DMEMIT(" autocommit_time %u", wc->autocommit_time_value);
if (wc->max_age_set)
DMEMIT(" max_age %u", wc->max_age_value);
if (wc->cleaner_set)
DMEMIT(" cleaner");
if (wc->writeback_fua_set)
DMEMIT(" %sfua", wc->writeback_fua ? "" : "no");
if (wc->metadata_only)
DMEMIT(" metadata_only");
if (wc->pause_set)
DMEMIT(" pause_writeback %u", wc->pause_value);
break;
case STATUSTYPE_IMA:
*result = '\0';
break;
}
}
static struct target_type writecache_target = {
.name = "writecache",
.version = {1, 6, 0},
.module = THIS_MODULE,
.ctr = writecache_ctr,
.dtr = writecache_dtr,
.status = writecache_status,
.postsuspend = writecache_suspend,
.resume = writecache_resume,
.message = writecache_message,
.map = writecache_map,
.end_io = writecache_end_io,
.iterate_devices = writecache_iterate_devices,
.io_hints = writecache_io_hints,
};
module_dm(writecache);
MODULE_DESCRIPTION(DM_NAME " writecache target");
MODULE_AUTHOR("Mikulas Patocka <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-writecache.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2006-2009 Red Hat, Inc.
*
* This file is released under the LGPL.
*/
#include <linux/bio.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/dm-dirty-log.h>
#include <linux/device-mapper.h>
#include <linux/dm-log-userspace.h>
#include <linux/module.h>
#include <linux/workqueue.h>
#include "dm-log-userspace-transfer.h"
#define DM_LOG_USERSPACE_VSN "1.3.0"
#define FLUSH_ENTRY_POOL_SIZE 16
struct dm_dirty_log_flush_entry {
int type;
region_t region;
struct list_head list;
};
/*
* This limit on the number of mark and clear request is, to a degree,
* arbitrary. However, there is some basis for the choice in the limits
* imposed on the size of data payload by dm-log-userspace-transfer.c:
* dm_consult_userspace().
*/
#define MAX_FLUSH_GROUP_COUNT 32
struct log_c {
struct dm_target *ti;
struct dm_dev *log_dev;
char *usr_argv_str;
uint32_t usr_argc;
uint32_t region_size;
region_t region_count;
uint64_t luid;
char uuid[DM_UUID_LEN];
/*
* Mark and clear requests are held until a flush is issued
* so that we can group, and thereby limit, the amount of
* network traffic between kernel and userspace. The 'flush_lock'
* is used to protect these lists.
*/
spinlock_t flush_lock;
struct list_head mark_list;
struct list_head clear_list;
/*
* in_sync_hint gets set when doing is_remote_recovering. It
* represents the first region that needs recovery. IOW, the
* first zero bit of sync_bits. This can be useful for to limit
* traffic for calls like is_remote_recovering and get_resync_work,
* but be take care in its use for anything else.
*/
uint64_t in_sync_hint;
/*
* Workqueue for flush of clear region requests.
*/
struct workqueue_struct *dmlog_wq;
struct delayed_work flush_log_work;
atomic_t sched_flush;
/*
* Combine userspace flush and mark requests for efficiency.
*/
uint32_t integrated_flush;
mempool_t flush_entry_pool;
};
static struct kmem_cache *_flush_entry_cache;
static int userspace_do_request(struct log_c *lc, const char *uuid,
int request_type, char *data, size_t data_size,
char *rdata, size_t *rdata_size)
{
int r;
/*
* If the server isn't there, -ESRCH is returned,
* and we must keep trying until the server is
* restored.
*/
retry:
r = dm_consult_userspace(uuid, lc->luid, request_type, data,
data_size, rdata, rdata_size);
if (r != -ESRCH)
return r;
DMERR(" Userspace log server not found.");
while (1) {
set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(2*HZ);
DMWARN("Attempting to contact userspace log server...");
r = dm_consult_userspace(uuid, lc->luid, DM_ULOG_CTR,
lc->usr_argv_str,
strlen(lc->usr_argv_str) + 1,
NULL, NULL);
if (!r)
break;
}
DMINFO("Reconnected to userspace log server... DM_ULOG_CTR complete");
r = dm_consult_userspace(uuid, lc->luid, DM_ULOG_RESUME, NULL,
0, NULL, NULL);
if (!r)
goto retry;
DMERR("Error trying to resume userspace log: %d", r);
return -ESRCH;
}
static int build_constructor_string(struct dm_target *ti,
unsigned int argc, char **argv,
char **ctr_str)
{
int i, str_size;
char *str = NULL;
*ctr_str = NULL;
/*
* Determine overall size of the string.
*/
for (i = 0, str_size = 0; i < argc; i++)
str_size += strlen(argv[i]) + 1; /* +1 for space between args */
str_size += 20; /* Max number of chars in a printed u64 number */
str = kzalloc(str_size, GFP_KERNEL);
if (!str) {
DMWARN("Unable to allocate memory for constructor string");
return -ENOMEM;
}
str_size = sprintf(str, "%llu", (unsigned long long)ti->len);
for (i = 0; i < argc; i++)
str_size += sprintf(str + str_size, " %s", argv[i]);
*ctr_str = str;
return str_size;
}
static void do_flush(struct work_struct *work)
{
int r;
struct log_c *lc = container_of(work, struct log_c, flush_log_work.work);
atomic_set(&lc->sched_flush, 0);
r = userspace_do_request(lc, lc->uuid, DM_ULOG_FLUSH, NULL, 0, NULL, NULL);
if (r)
dm_table_event(lc->ti->table);
}
/*
* userspace_ctr
*
* argv contains:
* <UUID> [integrated_flush] <other args>
* Where 'other args' are the userspace implementation-specific log
* arguments.
*
* Example:
* <UUID> [integrated_flush] clustered-disk <arg count> <log dev>
* <region_size> [[no]sync]
*
* This module strips off the <UUID> and uses it for identification
* purposes when communicating with userspace about a log.
*
* If integrated_flush is defined, the kernel combines flush
* and mark requests.
*
* The rest of the line, beginning with 'clustered-disk', is passed
* to the userspace ctr function.
*/
static int userspace_ctr(struct dm_dirty_log *log, struct dm_target *ti,
unsigned int argc, char **argv)
{
int r = 0;
int str_size;
char *ctr_str = NULL;
struct log_c *lc = NULL;
uint64_t rdata;
size_t rdata_size = sizeof(rdata);
char *devices_rdata = NULL;
size_t devices_rdata_size = DM_NAME_LEN;
if (argc < 3) {
DMWARN("Too few arguments to userspace dirty log");
return -EINVAL;
}
lc = kzalloc(sizeof(*lc), GFP_KERNEL);
if (!lc) {
DMWARN("Unable to allocate userspace log context.");
return -ENOMEM;
}
/* The ptr value is sufficient for local unique id */
lc->luid = (unsigned long)lc;
lc->ti = ti;
if (strlen(argv[0]) > (DM_UUID_LEN - 1)) {
DMWARN("UUID argument too long.");
kfree(lc);
return -EINVAL;
}
lc->usr_argc = argc;
strncpy(lc->uuid, argv[0], DM_UUID_LEN);
argc--;
argv++;
spin_lock_init(&lc->flush_lock);
INIT_LIST_HEAD(&lc->mark_list);
INIT_LIST_HEAD(&lc->clear_list);
if (!strcasecmp(argv[0], "integrated_flush")) {
lc->integrated_flush = 1;
argc--;
argv++;
}
str_size = build_constructor_string(ti, argc, argv, &ctr_str);
if (str_size < 0) {
kfree(lc);
return str_size;
}
devices_rdata = kzalloc(devices_rdata_size, GFP_KERNEL);
if (!devices_rdata) {
DMERR("Failed to allocate memory for device information");
r = -ENOMEM;
goto out;
}
r = mempool_init_slab_pool(&lc->flush_entry_pool, FLUSH_ENTRY_POOL_SIZE,
_flush_entry_cache);
if (r) {
DMERR("Failed to create flush_entry_pool");
goto out;
}
/*
* Send table string and get back any opened device.
*/
r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_CTR,
ctr_str, str_size,
devices_rdata, &devices_rdata_size);
if (r < 0) {
if (r == -ESRCH)
DMERR("Userspace log server not found");
else
DMERR("Userspace log server failed to create log");
goto out;
}
/* Since the region size does not change, get it now */
rdata_size = sizeof(rdata);
r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_GET_REGION_SIZE,
NULL, 0, (char *)&rdata, &rdata_size);
if (r) {
DMERR("Failed to get region size of dirty log");
goto out;
}
lc->region_size = (uint32_t)rdata;
lc->region_count = dm_sector_div_up(ti->len, lc->region_size);
if (devices_rdata_size) {
if (devices_rdata[devices_rdata_size - 1] != '\0') {
DMERR("DM_ULOG_CTR device return string not properly terminated");
r = -EINVAL;
goto out;
}
r = dm_get_device(ti, devices_rdata,
dm_table_get_mode(ti->table), &lc->log_dev);
if (r)
DMERR("Failed to register %s with device-mapper",
devices_rdata);
}
if (lc->integrated_flush) {
lc->dmlog_wq = alloc_workqueue("dmlogd", WQ_MEM_RECLAIM, 0);
if (!lc->dmlog_wq) {
DMERR("couldn't start dmlogd");
r = -ENOMEM;
goto out;
}
INIT_DELAYED_WORK(&lc->flush_log_work, do_flush);
atomic_set(&lc->sched_flush, 0);
}
out:
kfree(devices_rdata);
if (r) {
mempool_exit(&lc->flush_entry_pool);
kfree(lc);
kfree(ctr_str);
} else {
lc->usr_argv_str = ctr_str;
log->context = lc;
}
return r;
}
static void userspace_dtr(struct dm_dirty_log *log)
{
struct log_c *lc = log->context;
if (lc->integrated_flush) {
/* flush workqueue */
if (atomic_read(&lc->sched_flush))
flush_delayed_work(&lc->flush_log_work);
destroy_workqueue(lc->dmlog_wq);
}
(void) dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_DTR,
NULL, 0, NULL, NULL);
if (lc->log_dev)
dm_put_device(lc->ti, lc->log_dev);
mempool_exit(&lc->flush_entry_pool);
kfree(lc->usr_argv_str);
kfree(lc);
}
static int userspace_presuspend(struct dm_dirty_log *log)
{
int r;
struct log_c *lc = log->context;
r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_PRESUSPEND,
NULL, 0, NULL, NULL);
return r;
}
static int userspace_postsuspend(struct dm_dirty_log *log)
{
int r;
struct log_c *lc = log->context;
/*
* Run planned flush earlier.
*/
if (lc->integrated_flush && atomic_read(&lc->sched_flush))
flush_delayed_work(&lc->flush_log_work);
r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_POSTSUSPEND,
NULL, 0, NULL, NULL);
return r;
}
static int userspace_resume(struct dm_dirty_log *log)
{
int r;
struct log_c *lc = log->context;
lc->in_sync_hint = 0;
r = dm_consult_userspace(lc->uuid, lc->luid, DM_ULOG_RESUME,
NULL, 0, NULL, NULL);
return r;
}
static uint32_t userspace_get_region_size(struct dm_dirty_log *log)
{
struct log_c *lc = log->context;
return lc->region_size;
}
/*
* userspace_is_clean
*
* Check whether a region is clean. If there is any sort of
* failure when consulting the server, we return not clean.
*
* Returns: 1 if clean, 0 otherwise
*/
static int userspace_is_clean(struct dm_dirty_log *log, region_t region)
{
int r;
uint64_t region64 = (uint64_t)region;
int64_t is_clean;
size_t rdata_size;
struct log_c *lc = log->context;
rdata_size = sizeof(is_clean);
r = userspace_do_request(lc, lc->uuid, DM_ULOG_IS_CLEAN,
(char *)®ion64, sizeof(region64),
(char *)&is_clean, &rdata_size);
return (r) ? 0 : (int)is_clean;
}
/*
* userspace_in_sync
*
* Check if the region is in-sync. If there is any sort
* of failure when consulting the server, we assume that
* the region is not in sync.
*
* If 'can_block' is set, return immediately
*
* Returns: 1 if in-sync, 0 if not-in-sync, -EWOULDBLOCK
*/
static int userspace_in_sync(struct dm_dirty_log *log, region_t region,
int can_block)
{
int r;
uint64_t region64 = region;
int64_t in_sync;
size_t rdata_size;
struct log_c *lc = log->context;
/*
* We can never respond directly - even if in_sync_hint is
* set. This is because another machine could see a device
* failure and mark the region out-of-sync. If we don't go
* to userspace to ask, we might think the region is in-sync
* and allow a read to pick up data that is stale. (This is
* very unlikely if a device actually fails; but it is very
* likely if a connection to one device from one machine fails.)
*
* There still might be a problem if the mirror caches the region
* state as in-sync... but then this call would not be made. So,
* that is a mirror problem.
*/
if (!can_block)
return -EWOULDBLOCK;
rdata_size = sizeof(in_sync);
r = userspace_do_request(lc, lc->uuid, DM_ULOG_IN_SYNC,
(char *)®ion64, sizeof(region64),
(char *)&in_sync, &rdata_size);
return (r) ? 0 : (int)in_sync;
}
static int flush_one_by_one(struct log_c *lc, struct list_head *flush_list)
{
int r = 0;
struct dm_dirty_log_flush_entry *fe;
list_for_each_entry(fe, flush_list, list) {
r = userspace_do_request(lc, lc->uuid, fe->type,
(char *)&fe->region,
sizeof(fe->region),
NULL, NULL);
if (r)
break;
}
return r;
}
static int flush_by_group(struct log_c *lc, struct list_head *flush_list,
int flush_with_payload)
{
int r = 0;
int count;
uint32_t type = 0;
struct dm_dirty_log_flush_entry *fe, *tmp_fe;
LIST_HEAD(tmp_list);
uint64_t group[MAX_FLUSH_GROUP_COUNT];
/*
* Group process the requests
*/
while (!list_empty(flush_list)) {
count = 0;
list_for_each_entry_safe(fe, tmp_fe, flush_list, list) {
group[count] = fe->region;
count++;
list_move(&fe->list, &tmp_list);
type = fe->type;
if (count >= MAX_FLUSH_GROUP_COUNT)
break;
}
if (flush_with_payload) {
r = userspace_do_request(lc, lc->uuid, DM_ULOG_FLUSH,
(char *)(group),
count * sizeof(uint64_t),
NULL, NULL);
/*
* Integrated flush failed.
*/
if (r)
break;
} else {
r = userspace_do_request(lc, lc->uuid, type,
(char *)(group),
count * sizeof(uint64_t),
NULL, NULL);
if (r) {
/*
* Group send failed. Attempt one-by-one.
*/
list_splice_init(&tmp_list, flush_list);
r = flush_one_by_one(lc, flush_list);
break;
}
}
}
/*
* Must collect flush_entrys that were successfully processed
* as a group so that they will be free'd by the caller.
*/
list_splice_init(&tmp_list, flush_list);
return r;
}
/*
* userspace_flush
*
* This function is ok to block.
* The flush happens in two stages. First, it sends all
* clear/mark requests that are on the list. Then it
* tells the server to commit them. This gives the
* server a chance to optimise the commit, instead of
* doing it for every request.
*
* Additionally, we could implement another thread that
* sends the requests up to the server - reducing the
* load on flush. Then the flush would have less in
* the list and be responsible for the finishing commit.
*
* Returns: 0 on success, < 0 on failure
*/
static int userspace_flush(struct dm_dirty_log *log)
{
int r = 0;
unsigned long flags;
struct log_c *lc = log->context;
LIST_HEAD(mark_list);
LIST_HEAD(clear_list);
int mark_list_is_empty;
int clear_list_is_empty;
struct dm_dirty_log_flush_entry *fe, *tmp_fe;
mempool_t *flush_entry_pool = &lc->flush_entry_pool;
spin_lock_irqsave(&lc->flush_lock, flags);
list_splice_init(&lc->mark_list, &mark_list);
list_splice_init(&lc->clear_list, &clear_list);
spin_unlock_irqrestore(&lc->flush_lock, flags);
mark_list_is_empty = list_empty(&mark_list);
clear_list_is_empty = list_empty(&clear_list);
if (mark_list_is_empty && clear_list_is_empty)
return 0;
r = flush_by_group(lc, &clear_list, 0);
if (r)
goto out;
if (!lc->integrated_flush) {
r = flush_by_group(lc, &mark_list, 0);
if (r)
goto out;
r = userspace_do_request(lc, lc->uuid, DM_ULOG_FLUSH,
NULL, 0, NULL, NULL);
goto out;
}
/*
* Send integrated flush request with mark_list as payload.
*/
r = flush_by_group(lc, &mark_list, 1);
if (r)
goto out;
if (mark_list_is_empty && !atomic_read(&lc->sched_flush)) {
/*
* When there are only clear region requests,
* we schedule a flush in the future.
*/
queue_delayed_work(lc->dmlog_wq, &lc->flush_log_work, 3 * HZ);
atomic_set(&lc->sched_flush, 1);
} else {
/*
* Cancel pending flush because we
* have already flushed in mark_region.
*/
cancel_delayed_work(&lc->flush_log_work);
atomic_set(&lc->sched_flush, 0);
}
out:
/*
* We can safely remove these entries, even after failure.
* Calling code will receive an error and will know that
* the log facility has failed.
*/
list_for_each_entry_safe(fe, tmp_fe, &mark_list, list) {
list_del(&fe->list);
mempool_free(fe, flush_entry_pool);
}
list_for_each_entry_safe(fe, tmp_fe, &clear_list, list) {
list_del(&fe->list);
mempool_free(fe, flush_entry_pool);
}
if (r)
dm_table_event(lc->ti->table);
return r;
}
/*
* userspace_mark_region
*
* This function should avoid blocking unless absolutely required.
* (Memory allocation is valid for blocking.)
*/
static void userspace_mark_region(struct dm_dirty_log *log, region_t region)
{
unsigned long flags;
struct log_c *lc = log->context;
struct dm_dirty_log_flush_entry *fe;
/* Wait for an allocation, but _never_ fail */
fe = mempool_alloc(&lc->flush_entry_pool, GFP_NOIO);
BUG_ON(!fe);
spin_lock_irqsave(&lc->flush_lock, flags);
fe->type = DM_ULOG_MARK_REGION;
fe->region = region;
list_add(&fe->list, &lc->mark_list);
spin_unlock_irqrestore(&lc->flush_lock, flags);
}
/*
* userspace_clear_region
*
* This function must not block.
* So, the alloc can't block. In the worst case, it is ok to
* fail. It would simply mean we can't clear the region.
* Does nothing to current sync context, but does mean
* the region will be re-sync'ed on a reload of the mirror
* even though it is in-sync.
*/
static void userspace_clear_region(struct dm_dirty_log *log, region_t region)
{
unsigned long flags;
struct log_c *lc = log->context;
struct dm_dirty_log_flush_entry *fe;
/*
* If we fail to allocate, we skip the clearing of
* the region. This doesn't hurt us in any way, except
* to cause the region to be resync'ed when the
* device is activated next time.
*/
fe = mempool_alloc(&lc->flush_entry_pool, GFP_ATOMIC);
if (!fe) {
DMERR("Failed to allocate memory to clear region.");
return;
}
spin_lock_irqsave(&lc->flush_lock, flags);
fe->type = DM_ULOG_CLEAR_REGION;
fe->region = region;
list_add(&fe->list, &lc->clear_list);
spin_unlock_irqrestore(&lc->flush_lock, flags);
}
/*
* userspace_get_resync_work
*
* Get a region that needs recovery. It is valid to return
* an error for this function.
*
* Returns: 1 if region filled, 0 if no work, <0 on error
*/
static int userspace_get_resync_work(struct dm_dirty_log *log, region_t *region)
{
int r;
size_t rdata_size;
struct log_c *lc = log->context;
struct {
int64_t i; /* 64-bit for mix arch compatibility */
region_t r;
} pkg;
if (lc->in_sync_hint >= lc->region_count)
return 0;
rdata_size = sizeof(pkg);
r = userspace_do_request(lc, lc->uuid, DM_ULOG_GET_RESYNC_WORK,
NULL, 0, (char *)&pkg, &rdata_size);
*region = pkg.r;
return (r) ? r : (int)pkg.i;
}
/*
* userspace_set_region_sync
*
* Set the sync status of a given region. This function
* must not fail.
*/
static void userspace_set_region_sync(struct dm_dirty_log *log,
region_t region, int in_sync)
{
struct log_c *lc = log->context;
struct {
region_t r;
int64_t i;
} pkg;
pkg.r = region;
pkg.i = (int64_t)in_sync;
(void) userspace_do_request(lc, lc->uuid, DM_ULOG_SET_REGION_SYNC,
(char *)&pkg, sizeof(pkg), NULL, NULL);
/*
* It would be nice to be able to report failures.
* However, it is easy enough to detect and resolve.
*/
}
/*
* userspace_get_sync_count
*
* If there is any sort of failure when consulting the server,
* we assume that the sync count is zero.
*
* Returns: sync count on success, 0 on failure
*/
static region_t userspace_get_sync_count(struct dm_dirty_log *log)
{
int r;
size_t rdata_size;
uint64_t sync_count;
struct log_c *lc = log->context;
rdata_size = sizeof(sync_count);
r = userspace_do_request(lc, lc->uuid, DM_ULOG_GET_SYNC_COUNT,
NULL, 0, (char *)&sync_count, &rdata_size);
if (r)
return 0;
if (sync_count >= lc->region_count)
lc->in_sync_hint = lc->region_count;
return (region_t)sync_count;
}
/*
* userspace_status
*
* Returns: amount of space consumed
*/
static int userspace_status(struct dm_dirty_log *log, status_type_t status_type,
char *result, unsigned int maxlen)
{
int r = 0;
char *table_args;
size_t sz = (size_t)maxlen;
struct log_c *lc = log->context;
switch (status_type) {
case STATUSTYPE_INFO:
r = userspace_do_request(lc, lc->uuid, DM_ULOG_STATUS_INFO,
NULL, 0, result, &sz);
if (r) {
sz = 0;
DMEMIT("%s 1 COM_FAILURE", log->type->name);
}
break;
case STATUSTYPE_TABLE:
sz = 0;
table_args = strchr(lc->usr_argv_str, ' ');
BUG_ON(!table_args); /* There will always be a ' ' */
table_args++;
DMEMIT("%s %u %s ", log->type->name, lc->usr_argc, lc->uuid);
if (lc->integrated_flush)
DMEMIT("integrated_flush ");
DMEMIT("%s ", table_args);
break;
case STATUSTYPE_IMA:
*result = '\0';
break;
}
return (r) ? 0 : (int)sz;
}
/*
* userspace_is_remote_recovering
*
* Returns: 1 if region recovering, 0 otherwise
*/
static int userspace_is_remote_recovering(struct dm_dirty_log *log,
region_t region)
{
int r;
uint64_t region64 = region;
struct log_c *lc = log->context;
static unsigned long limit;
struct {
int64_t is_recovering;
uint64_t in_sync_hint;
} pkg;
size_t rdata_size = sizeof(pkg);
/*
* Once the mirror has been reported to be in-sync,
* it will never again ask for recovery work. So,
* we can safely say there is not a remote machine
* recovering if the device is in-sync. (in_sync_hint
* must be reset at resume time.)
*/
if (region < lc->in_sync_hint)
return 0;
else if (time_after(limit, jiffies))
return 1;
limit = jiffies + (HZ / 4);
r = userspace_do_request(lc, lc->uuid, DM_ULOG_IS_REMOTE_RECOVERING,
(char *)®ion64, sizeof(region64),
(char *)&pkg, &rdata_size);
if (r)
return 1;
lc->in_sync_hint = pkg.in_sync_hint;
return (int)pkg.is_recovering;
}
static struct dm_dirty_log_type _userspace_type = {
.name = "userspace",
.module = THIS_MODULE,
.ctr = userspace_ctr,
.dtr = userspace_dtr,
.presuspend = userspace_presuspend,
.postsuspend = userspace_postsuspend,
.resume = userspace_resume,
.get_region_size = userspace_get_region_size,
.is_clean = userspace_is_clean,
.in_sync = userspace_in_sync,
.flush = userspace_flush,
.mark_region = userspace_mark_region,
.clear_region = userspace_clear_region,
.get_resync_work = userspace_get_resync_work,
.set_region_sync = userspace_set_region_sync,
.get_sync_count = userspace_get_sync_count,
.status = userspace_status,
.is_remote_recovering = userspace_is_remote_recovering,
};
static int __init userspace_dirty_log_init(void)
{
int r = 0;
_flush_entry_cache = KMEM_CACHE(dm_dirty_log_flush_entry, 0);
if (!_flush_entry_cache) {
DMWARN("Unable to create flush_entry_cache: No memory.");
return -ENOMEM;
}
r = dm_ulog_tfr_init();
if (r) {
DMWARN("Unable to initialize userspace log communications");
kmem_cache_destroy(_flush_entry_cache);
return r;
}
r = dm_dirty_log_type_register(&_userspace_type);
if (r) {
DMWARN("Couldn't register userspace dirty log type");
dm_ulog_tfr_exit();
kmem_cache_destroy(_flush_entry_cache);
return r;
}
DMINFO("version " DM_LOG_USERSPACE_VSN " loaded");
return 0;
}
static void __exit userspace_dirty_log_exit(void)
{
dm_dirty_log_type_unregister(&_userspace_type);
dm_ulog_tfr_exit();
kmem_cache_destroy(_flush_entry_cache);
DMINFO("version " DM_LOG_USERSPACE_VSN " unloaded");
}
module_init(userspace_dirty_log_init);
module_exit(userspace_dirty_log_exit);
MODULE_DESCRIPTION(DM_NAME " userspace dirty log link");
MODULE_AUTHOR("Jonathan Brassow <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-log-userspace-base.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2005-2007 Red Hat GmbH
*
* A target that delays reads and/or writes and can send
* them to different devices.
*
* This file is released under the GPL.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/bio.h>
#include <linux/slab.h>
#include <linux/device-mapper.h>
#define DM_MSG_PREFIX "delay"
struct delay_class {
struct dm_dev *dev;
sector_t start;
unsigned int delay;
unsigned int ops;
};
struct delay_c {
struct timer_list delay_timer;
struct mutex timer_lock;
struct workqueue_struct *kdelayd_wq;
struct work_struct flush_expired_bios;
struct list_head delayed_bios;
atomic_t may_delay;
struct delay_class read;
struct delay_class write;
struct delay_class flush;
int argc;
};
struct dm_delay_info {
struct delay_c *context;
struct delay_class *class;
struct list_head list;
unsigned long expires;
};
static DEFINE_MUTEX(delayed_bios_lock);
static void handle_delayed_timer(struct timer_list *t)
{
struct delay_c *dc = from_timer(dc, t, delay_timer);
queue_work(dc->kdelayd_wq, &dc->flush_expired_bios);
}
static void queue_timeout(struct delay_c *dc, unsigned long expires)
{
mutex_lock(&dc->timer_lock);
if (!timer_pending(&dc->delay_timer) || expires < dc->delay_timer.expires)
mod_timer(&dc->delay_timer, expires);
mutex_unlock(&dc->timer_lock);
}
static void flush_bios(struct bio *bio)
{
struct bio *n;
while (bio) {
n = bio->bi_next;
bio->bi_next = NULL;
dm_submit_bio_remap(bio, NULL);
bio = n;
}
}
static struct bio *flush_delayed_bios(struct delay_c *dc, int flush_all)
{
struct dm_delay_info *delayed, *next;
unsigned long next_expires = 0;
unsigned long start_timer = 0;
struct bio_list flush_bios = { };
mutex_lock(&delayed_bios_lock);
list_for_each_entry_safe(delayed, next, &dc->delayed_bios, list) {
if (flush_all || time_after_eq(jiffies, delayed->expires)) {
struct bio *bio = dm_bio_from_per_bio_data(delayed,
sizeof(struct dm_delay_info));
list_del(&delayed->list);
bio_list_add(&flush_bios, bio);
delayed->class->ops--;
continue;
}
if (!start_timer) {
start_timer = 1;
next_expires = delayed->expires;
} else
next_expires = min(next_expires, delayed->expires);
}
mutex_unlock(&delayed_bios_lock);
if (start_timer)
queue_timeout(dc, next_expires);
return bio_list_get(&flush_bios);
}
static void flush_expired_bios(struct work_struct *work)
{
struct delay_c *dc;
dc = container_of(work, struct delay_c, flush_expired_bios);
flush_bios(flush_delayed_bios(dc, 0));
}
static void delay_dtr(struct dm_target *ti)
{
struct delay_c *dc = ti->private;
if (dc->kdelayd_wq)
destroy_workqueue(dc->kdelayd_wq);
if (dc->read.dev)
dm_put_device(ti, dc->read.dev);
if (dc->write.dev)
dm_put_device(ti, dc->write.dev);
if (dc->flush.dev)
dm_put_device(ti, dc->flush.dev);
mutex_destroy(&dc->timer_lock);
kfree(dc);
}
static int delay_class_ctr(struct dm_target *ti, struct delay_class *c, char **argv)
{
int ret;
unsigned long long tmpll;
char dummy;
if (sscanf(argv[1], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) {
ti->error = "Invalid device sector";
return -EINVAL;
}
c->start = tmpll;
if (sscanf(argv[2], "%u%c", &c->delay, &dummy) != 1) {
ti->error = "Invalid delay";
return -EINVAL;
}
ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &c->dev);
if (ret) {
ti->error = "Device lookup failed";
return ret;
}
return 0;
}
/*
* Mapping parameters:
* <device> <offset> <delay> [<write_device> <write_offset> <write_delay>]
*
* With separate write parameters, the first set is only used for reads.
* Offsets are specified in sectors.
* Delays are specified in milliseconds.
*/
static int delay_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
struct delay_c *dc;
int ret;
if (argc != 3 && argc != 6 && argc != 9) {
ti->error = "Requires exactly 3, 6 or 9 arguments";
return -EINVAL;
}
dc = kzalloc(sizeof(*dc), GFP_KERNEL);
if (!dc) {
ti->error = "Cannot allocate context";
return -ENOMEM;
}
ti->private = dc;
timer_setup(&dc->delay_timer, handle_delayed_timer, 0);
INIT_WORK(&dc->flush_expired_bios, flush_expired_bios);
INIT_LIST_HEAD(&dc->delayed_bios);
mutex_init(&dc->timer_lock);
atomic_set(&dc->may_delay, 1);
dc->argc = argc;
ret = delay_class_ctr(ti, &dc->read, argv);
if (ret)
goto bad;
if (argc == 3) {
ret = delay_class_ctr(ti, &dc->write, argv);
if (ret)
goto bad;
ret = delay_class_ctr(ti, &dc->flush, argv);
if (ret)
goto bad;
goto out;
}
ret = delay_class_ctr(ti, &dc->write, argv + 3);
if (ret)
goto bad;
if (argc == 6) {
ret = delay_class_ctr(ti, &dc->flush, argv + 3);
if (ret)
goto bad;
goto out;
}
ret = delay_class_ctr(ti, &dc->flush, argv + 6);
if (ret)
goto bad;
out:
dc->kdelayd_wq = alloc_workqueue("kdelayd", WQ_MEM_RECLAIM, 0);
if (!dc->kdelayd_wq) {
ret = -EINVAL;
DMERR("Couldn't start kdelayd");
goto bad;
}
ti->num_flush_bios = 1;
ti->num_discard_bios = 1;
ti->accounts_remapped_io = true;
ti->per_io_data_size = sizeof(struct dm_delay_info);
return 0;
bad:
delay_dtr(ti);
return ret;
}
static int delay_bio(struct delay_c *dc, struct delay_class *c, struct bio *bio)
{
struct dm_delay_info *delayed;
unsigned long expires = 0;
if (!c->delay || !atomic_read(&dc->may_delay))
return DM_MAPIO_REMAPPED;
delayed = dm_per_bio_data(bio, sizeof(struct dm_delay_info));
delayed->context = dc;
delayed->expires = expires = jiffies + msecs_to_jiffies(c->delay);
mutex_lock(&delayed_bios_lock);
c->ops++;
list_add_tail(&delayed->list, &dc->delayed_bios);
mutex_unlock(&delayed_bios_lock);
queue_timeout(dc, expires);
return DM_MAPIO_SUBMITTED;
}
static void delay_presuspend(struct dm_target *ti)
{
struct delay_c *dc = ti->private;
atomic_set(&dc->may_delay, 0);
del_timer_sync(&dc->delay_timer);
flush_bios(flush_delayed_bios(dc, 1));
}
static void delay_resume(struct dm_target *ti)
{
struct delay_c *dc = ti->private;
atomic_set(&dc->may_delay, 1);
}
static int delay_map(struct dm_target *ti, struct bio *bio)
{
struct delay_c *dc = ti->private;
struct delay_class *c;
struct dm_delay_info *delayed = dm_per_bio_data(bio, sizeof(struct dm_delay_info));
if (bio_data_dir(bio) == WRITE) {
if (unlikely(bio->bi_opf & REQ_PREFLUSH))
c = &dc->flush;
else
c = &dc->write;
} else {
c = &dc->read;
}
delayed->class = c;
bio_set_dev(bio, c->dev->bdev);
bio->bi_iter.bi_sector = c->start + dm_target_offset(ti, bio->bi_iter.bi_sector);
return delay_bio(dc, c, bio);
}
#define DMEMIT_DELAY_CLASS(c) \
DMEMIT("%s %llu %u", (c)->dev->name, (unsigned long long)(c)->start, (c)->delay)
static void delay_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
struct delay_c *dc = ti->private;
int sz = 0;
switch (type) {
case STATUSTYPE_INFO:
DMEMIT("%u %u %u", dc->read.ops, dc->write.ops, dc->flush.ops);
break;
case STATUSTYPE_TABLE:
DMEMIT_DELAY_CLASS(&dc->read);
if (dc->argc >= 6) {
DMEMIT(" ");
DMEMIT_DELAY_CLASS(&dc->write);
}
if (dc->argc >= 9) {
DMEMIT(" ");
DMEMIT_DELAY_CLASS(&dc->flush);
}
break;
case STATUSTYPE_IMA:
*result = '\0';
break;
}
}
static int delay_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct delay_c *dc = ti->private;
int ret = 0;
ret = fn(ti, dc->read.dev, dc->read.start, ti->len, data);
if (ret)
goto out;
ret = fn(ti, dc->write.dev, dc->write.start, ti->len, data);
if (ret)
goto out;
ret = fn(ti, dc->flush.dev, dc->flush.start, ti->len, data);
if (ret)
goto out;
out:
return ret;
}
static struct target_type delay_target = {
.name = "delay",
.version = {1, 3, 0},
.features = DM_TARGET_PASSES_INTEGRITY,
.module = THIS_MODULE,
.ctr = delay_ctr,
.dtr = delay_dtr,
.map = delay_map,
.presuspend = delay_presuspend,
.resume = delay_resume,
.status = delay_status,
.iterate_devices = delay_iterate_devices,
};
module_dm(delay);
MODULE_DESCRIPTION(DM_NAME " delay target");
MODULE_AUTHOR("Heinz Mauelshagen <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-delay.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2003 Sistina Software.
* Copyright (C) 2004 Red Hat, Inc. All rights reserved.
*
* Module Author: Heinz Mauelshagen
*
* This file is released under the GPL.
*
* Path selector registration.
*/
#include <linux/device-mapper.h>
#include <linux/module.h>
#include "dm-path-selector.h"
#include <linux/slab.h>
struct ps_internal {
struct path_selector_type pst;
struct list_head list;
};
#define pst_to_psi(__pst) container_of((__pst), struct ps_internal, pst)
static LIST_HEAD(_path_selectors);
static DECLARE_RWSEM(_ps_lock);
static struct ps_internal *__find_path_selector_type(const char *name)
{
struct ps_internal *psi;
list_for_each_entry(psi, &_path_selectors, list) {
if (!strcmp(name, psi->pst.name))
return psi;
}
return NULL;
}
static struct ps_internal *get_path_selector(const char *name)
{
struct ps_internal *psi;
down_read(&_ps_lock);
psi = __find_path_selector_type(name);
if (psi && !try_module_get(psi->pst.module))
psi = NULL;
up_read(&_ps_lock);
return psi;
}
struct path_selector_type *dm_get_path_selector(const char *name)
{
struct ps_internal *psi;
if (!name)
return NULL;
psi = get_path_selector(name);
if (!psi) {
request_module("dm-%s", name);
psi = get_path_selector(name);
}
return psi ? &psi->pst : NULL;
}
void dm_put_path_selector(struct path_selector_type *pst)
{
struct ps_internal *psi;
if (!pst)
return;
down_read(&_ps_lock);
psi = __find_path_selector_type(pst->name);
if (!psi)
goto out;
module_put(psi->pst.module);
out:
up_read(&_ps_lock);
}
static struct ps_internal *_alloc_path_selector(struct path_selector_type *pst)
{
struct ps_internal *psi = kzalloc(sizeof(*psi), GFP_KERNEL);
if (psi)
psi->pst = *pst;
return psi;
}
int dm_register_path_selector(struct path_selector_type *pst)
{
int r = 0;
struct ps_internal *psi = _alloc_path_selector(pst);
if (!psi)
return -ENOMEM;
down_write(&_ps_lock);
if (__find_path_selector_type(pst->name)) {
kfree(psi);
r = -EEXIST;
} else
list_add(&psi->list, &_path_selectors);
up_write(&_ps_lock);
return r;
}
EXPORT_SYMBOL_GPL(dm_register_path_selector);
int dm_unregister_path_selector(struct path_selector_type *pst)
{
struct ps_internal *psi;
down_write(&_ps_lock);
psi = __find_path_selector_type(pst->name);
if (!psi) {
up_write(&_ps_lock);
return -EINVAL;
}
list_del(&psi->list);
up_write(&_ps_lock);
kfree(psi);
return 0;
}
EXPORT_SYMBOL_GPL(dm_unregister_path_selector);
| linux-master | drivers/md/dm-path-selector.c |
// SPDX-License-Identifier: GPL-2.0-only
#include "dm-core.h"
/*
* The kobject release method must not be placed in the module itself,
* otherwise we are subject to module unload races.
*
* The release method is called when the last reference to the kobject is
* dropped. It may be called by any other kernel code that drops the last
* reference.
*
* The release method suffers from module unload race. We may prevent the
* module from being unloaded at the start of the release method (using
* increased module reference count or synchronizing against the release
* method), however there is no way to prevent the module from being
* unloaded at the end of the release method.
*
* If this code were placed in the dm module, the following race may
* happen:
* 1. Some other process takes a reference to dm kobject
* 2. The user issues ioctl function to unload the dm device
* 3. dm_sysfs_exit calls kobject_put, however the object is not released
* because of the other reference taken at step 1
* 4. dm_sysfs_exit waits on the completion
* 5. The other process that took the reference in step 1 drops it,
* dm_kobject_release is called from this process
* 6. dm_kobject_release calls complete()
* 7. a reschedule happens before dm_kobject_release returns
* 8. dm_sysfs_exit continues, the dm device is unloaded, module reference
* count is decremented
* 9. The user unloads the dm module
* 10. The other process that was rescheduled in step 7 continues to run,
* it is now executing code in unloaded module, so it crashes
*
* Note that if the process that takes the foreign reference to dm kobject
* has a low priority and the system is sufficiently loaded with
* higher-priority processes that prevent the low-priority process from
* being scheduled long enough, this bug may really happen.
*
* In order to fix this module unload race, we place the release method
* into a helper code that is compiled directly into the kernel.
*/
void dm_kobject_release(struct kobject *kobj)
{
complete(dm_get_completion_from_kobject(kobj));
}
EXPORT_SYMBOL(dm_kobject_release);
| linux-master | drivers/md/dm-builtin.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2017 Western Digital Corporation or its affiliates.
*
* This file is released under the GPL.
*/
#include "dm-zoned.h"
#include <linux/module.h>
#define DM_MSG_PREFIX "zoned reclaim"
struct dmz_reclaim {
struct dmz_metadata *metadata;
struct delayed_work work;
struct workqueue_struct *wq;
struct dm_kcopyd_client *kc;
struct dm_kcopyd_throttle kc_throttle;
int kc_err;
int dev_idx;
unsigned long flags;
/* Last target access time */
unsigned long atime;
};
/*
* Reclaim state flags.
*/
enum {
DMZ_RECLAIM_KCOPY,
};
/*
* Number of seconds of target BIO inactivity to consider the target idle.
*/
#define DMZ_IDLE_PERIOD (10UL * HZ)
/*
* Percentage of unmapped (free) random zones below which reclaim starts
* even if the target is busy.
*/
#define DMZ_RECLAIM_LOW_UNMAP_ZONES 30
/*
* Percentage of unmapped (free) random zones above which reclaim will
* stop if the target is busy.
*/
#define DMZ_RECLAIM_HIGH_UNMAP_ZONES 50
/*
* Align a sequential zone write pointer to chunk_block.
*/
static int dmz_reclaim_align_wp(struct dmz_reclaim *zrc, struct dm_zone *zone,
sector_t block)
{
struct dmz_metadata *zmd = zrc->metadata;
struct dmz_dev *dev = zone->dev;
sector_t wp_block = zone->wp_block;
unsigned int nr_blocks;
int ret;
if (wp_block == block)
return 0;
if (wp_block > block)
return -EIO;
/*
* Zeroout the space between the write
* pointer and the requested position.
*/
nr_blocks = block - wp_block;
ret = blkdev_issue_zeroout(dev->bdev,
dmz_start_sect(zmd, zone) + dmz_blk2sect(wp_block),
dmz_blk2sect(nr_blocks), GFP_NOIO, 0);
if (ret) {
dmz_dev_err(dev,
"Align zone %u wp %llu to %llu (wp+%u) blocks failed %d",
zone->id, (unsigned long long)wp_block,
(unsigned long long)block, nr_blocks, ret);
dmz_check_bdev(dev);
return ret;
}
zone->wp_block = block;
return 0;
}
/*
* dm_kcopyd_copy end notification.
*/
static void dmz_reclaim_kcopy_end(int read_err, unsigned long write_err,
void *context)
{
struct dmz_reclaim *zrc = context;
if (read_err || write_err)
zrc->kc_err = -EIO;
else
zrc->kc_err = 0;
clear_bit_unlock(DMZ_RECLAIM_KCOPY, &zrc->flags);
smp_mb__after_atomic();
wake_up_bit(&zrc->flags, DMZ_RECLAIM_KCOPY);
}
/*
* Copy valid blocks of src_zone into dst_zone.
*/
static int dmz_reclaim_copy(struct dmz_reclaim *zrc,
struct dm_zone *src_zone, struct dm_zone *dst_zone)
{
struct dmz_metadata *zmd = zrc->metadata;
struct dm_io_region src, dst;
sector_t block = 0, end_block;
sector_t nr_blocks;
sector_t src_zone_block;
sector_t dst_zone_block;
unsigned long flags = 0;
int ret;
if (dmz_is_seq(src_zone))
end_block = src_zone->wp_block;
else
end_block = dmz_zone_nr_blocks(zmd);
src_zone_block = dmz_start_block(zmd, src_zone);
dst_zone_block = dmz_start_block(zmd, dst_zone);
if (dmz_is_seq(dst_zone))
flags |= BIT(DM_KCOPYD_WRITE_SEQ);
while (block < end_block) {
if (src_zone->dev->flags & DMZ_BDEV_DYING)
return -EIO;
if (dst_zone->dev->flags & DMZ_BDEV_DYING)
return -EIO;
if (dmz_reclaim_should_terminate(src_zone))
return -EINTR;
/* Get a valid region from the source zone */
ret = dmz_first_valid_block(zmd, src_zone, &block);
if (ret <= 0)
return ret;
nr_blocks = ret;
/*
* If we are writing in a sequential zone, we must make sure
* that writes are sequential. So Zeroout any eventual hole
* between writes.
*/
if (dmz_is_seq(dst_zone)) {
ret = dmz_reclaim_align_wp(zrc, dst_zone, block);
if (ret)
return ret;
}
src.bdev = src_zone->dev->bdev;
src.sector = dmz_blk2sect(src_zone_block + block);
src.count = dmz_blk2sect(nr_blocks);
dst.bdev = dst_zone->dev->bdev;
dst.sector = dmz_blk2sect(dst_zone_block + block);
dst.count = src.count;
/* Copy the valid region */
set_bit(DMZ_RECLAIM_KCOPY, &zrc->flags);
dm_kcopyd_copy(zrc->kc, &src, 1, &dst, flags,
dmz_reclaim_kcopy_end, zrc);
/* Wait for copy to complete */
wait_on_bit_io(&zrc->flags, DMZ_RECLAIM_KCOPY,
TASK_UNINTERRUPTIBLE);
if (zrc->kc_err)
return zrc->kc_err;
block += nr_blocks;
if (dmz_is_seq(dst_zone))
dst_zone->wp_block = block;
}
return 0;
}
/*
* Move valid blocks of dzone buffer zone into dzone (after its write pointer)
* and free the buffer zone.
*/
static int dmz_reclaim_buf(struct dmz_reclaim *zrc, struct dm_zone *dzone)
{
struct dm_zone *bzone = dzone->bzone;
sector_t chunk_block = dzone->wp_block;
struct dmz_metadata *zmd = zrc->metadata;
int ret;
DMDEBUG("(%s/%u): Chunk %u, move buf zone %u (weight %u) to data zone %u (weight %u)",
dmz_metadata_label(zmd), zrc->dev_idx,
dzone->chunk, bzone->id, dmz_weight(bzone),
dzone->id, dmz_weight(dzone));
/* Flush data zone into the buffer zone */
ret = dmz_reclaim_copy(zrc, bzone, dzone);
if (ret < 0)
return ret;
dmz_lock_flush(zmd);
/* Validate copied blocks */
ret = dmz_merge_valid_blocks(zmd, bzone, dzone, chunk_block);
if (ret == 0) {
/* Free the buffer zone */
dmz_invalidate_blocks(zmd, bzone, 0, dmz_zone_nr_blocks(zmd));
dmz_lock_map(zmd);
dmz_unmap_zone(zmd, bzone);
dmz_unlock_zone_reclaim(dzone);
dmz_free_zone(zmd, bzone);
dmz_unlock_map(zmd);
}
dmz_unlock_flush(zmd);
return ret;
}
/*
* Merge valid blocks of dzone into its buffer zone and free dzone.
*/
static int dmz_reclaim_seq_data(struct dmz_reclaim *zrc, struct dm_zone *dzone)
{
unsigned int chunk = dzone->chunk;
struct dm_zone *bzone = dzone->bzone;
struct dmz_metadata *zmd = zrc->metadata;
int ret = 0;
DMDEBUG("(%s/%u): Chunk %u, move data zone %u (weight %u) to buf zone %u (weight %u)",
dmz_metadata_label(zmd), zrc->dev_idx,
chunk, dzone->id, dmz_weight(dzone),
bzone->id, dmz_weight(bzone));
/* Flush data zone into the buffer zone */
ret = dmz_reclaim_copy(zrc, dzone, bzone);
if (ret < 0)
return ret;
dmz_lock_flush(zmd);
/* Validate copied blocks */
ret = dmz_merge_valid_blocks(zmd, dzone, bzone, 0);
if (ret == 0) {
/*
* Free the data zone and remap the chunk to
* the buffer zone.
*/
dmz_invalidate_blocks(zmd, dzone, 0, dmz_zone_nr_blocks(zmd));
dmz_lock_map(zmd);
dmz_unmap_zone(zmd, bzone);
dmz_unmap_zone(zmd, dzone);
dmz_unlock_zone_reclaim(dzone);
dmz_free_zone(zmd, dzone);
dmz_map_zone(zmd, bzone, chunk);
dmz_unlock_map(zmd);
}
dmz_unlock_flush(zmd);
return ret;
}
/*
* Move valid blocks of the random data zone dzone into a free sequential zone.
* Once blocks are moved, remap the zone chunk to the sequential zone.
*/
static int dmz_reclaim_rnd_data(struct dmz_reclaim *zrc, struct dm_zone *dzone)
{
unsigned int chunk = dzone->chunk;
struct dm_zone *szone = NULL;
struct dmz_metadata *zmd = zrc->metadata;
int ret;
int alloc_flags = DMZ_ALLOC_SEQ;
/* Get a free random or sequential zone */
dmz_lock_map(zmd);
again:
szone = dmz_alloc_zone(zmd, zrc->dev_idx,
alloc_flags | DMZ_ALLOC_RECLAIM);
if (!szone && alloc_flags == DMZ_ALLOC_SEQ && dmz_nr_cache_zones(zmd)) {
alloc_flags = DMZ_ALLOC_RND;
goto again;
}
dmz_unlock_map(zmd);
if (!szone)
return -ENOSPC;
DMDEBUG("(%s/%u): Chunk %u, move %s zone %u (weight %u) to %s zone %u",
dmz_metadata_label(zmd), zrc->dev_idx, chunk,
dmz_is_cache(dzone) ? "cache" : "rnd",
dzone->id, dmz_weight(dzone),
dmz_is_rnd(szone) ? "rnd" : "seq", szone->id);
/* Flush the random data zone into the sequential zone */
ret = dmz_reclaim_copy(zrc, dzone, szone);
dmz_lock_flush(zmd);
if (ret == 0) {
/* Validate copied blocks */
ret = dmz_copy_valid_blocks(zmd, dzone, szone);
}
if (ret) {
/* Free the sequential zone */
dmz_lock_map(zmd);
dmz_free_zone(zmd, szone);
dmz_unlock_map(zmd);
} else {
/* Free the data zone and remap the chunk */
dmz_invalidate_blocks(zmd, dzone, 0, dmz_zone_nr_blocks(zmd));
dmz_lock_map(zmd);
dmz_unmap_zone(zmd, dzone);
dmz_unlock_zone_reclaim(dzone);
dmz_free_zone(zmd, dzone);
dmz_map_zone(zmd, szone, chunk);
dmz_unlock_map(zmd);
}
dmz_unlock_flush(zmd);
return ret;
}
/*
* Reclaim an empty zone.
*/
static void dmz_reclaim_empty(struct dmz_reclaim *zrc, struct dm_zone *dzone)
{
struct dmz_metadata *zmd = zrc->metadata;
dmz_lock_flush(zmd);
dmz_lock_map(zmd);
dmz_unmap_zone(zmd, dzone);
dmz_unlock_zone_reclaim(dzone);
dmz_free_zone(zmd, dzone);
dmz_unlock_map(zmd);
dmz_unlock_flush(zmd);
}
/*
* Test if the target device is idle.
*/
static inline int dmz_target_idle(struct dmz_reclaim *zrc)
{
return time_is_before_jiffies(zrc->atime + DMZ_IDLE_PERIOD);
}
/*
* Find a candidate zone for reclaim and process it.
*/
static int dmz_do_reclaim(struct dmz_reclaim *zrc)
{
struct dmz_metadata *zmd = zrc->metadata;
struct dm_zone *dzone;
struct dm_zone *rzone;
unsigned long start;
int ret;
/* Get a data zone */
dzone = dmz_get_zone_for_reclaim(zmd, zrc->dev_idx,
dmz_target_idle(zrc));
if (!dzone) {
DMDEBUG("(%s/%u): No zone found to reclaim",
dmz_metadata_label(zmd), zrc->dev_idx);
return -EBUSY;
}
rzone = dzone;
start = jiffies;
if (dmz_is_cache(dzone) || dmz_is_rnd(dzone)) {
if (!dmz_weight(dzone)) {
/* Empty zone */
dmz_reclaim_empty(zrc, dzone);
ret = 0;
} else {
/*
* Reclaim the random data zone by moving its
* valid data blocks to a free sequential zone.
*/
ret = dmz_reclaim_rnd_data(zrc, dzone);
}
} else {
struct dm_zone *bzone = dzone->bzone;
sector_t chunk_block = 0;
ret = dmz_first_valid_block(zmd, bzone, &chunk_block);
if (ret < 0)
goto out;
if (ret == 0 || chunk_block >= dzone->wp_block) {
/*
* The buffer zone is empty or its valid blocks are
* after the data zone write pointer.
*/
ret = dmz_reclaim_buf(zrc, dzone);
rzone = bzone;
} else {
/*
* Reclaim the data zone by merging it into the
* buffer zone so that the buffer zone itself can
* be later reclaimed.
*/
ret = dmz_reclaim_seq_data(zrc, dzone);
}
}
out:
if (ret) {
if (ret == -EINTR)
DMDEBUG("(%s/%u): reclaim zone %u interrupted",
dmz_metadata_label(zmd), zrc->dev_idx,
rzone->id);
else
DMDEBUG("(%s/%u): Failed to reclaim zone %u, err %d",
dmz_metadata_label(zmd), zrc->dev_idx,
rzone->id, ret);
dmz_unlock_zone_reclaim(dzone);
return ret;
}
ret = dmz_flush_metadata(zrc->metadata);
if (ret) {
DMDEBUG("(%s/%u): Metadata flush for zone %u failed, err %d",
dmz_metadata_label(zmd), zrc->dev_idx, rzone->id, ret);
return ret;
}
DMDEBUG("(%s/%u): Reclaimed zone %u in %u ms",
dmz_metadata_label(zmd), zrc->dev_idx,
rzone->id, jiffies_to_msecs(jiffies - start));
return 0;
}
static unsigned int dmz_reclaim_percentage(struct dmz_reclaim *zrc)
{
struct dmz_metadata *zmd = zrc->metadata;
unsigned int nr_cache = dmz_nr_cache_zones(zmd);
unsigned int nr_unmap, nr_zones;
if (nr_cache) {
nr_zones = nr_cache;
nr_unmap = dmz_nr_unmap_cache_zones(zmd);
} else {
nr_zones = dmz_nr_rnd_zones(zmd, zrc->dev_idx);
nr_unmap = dmz_nr_unmap_rnd_zones(zmd, zrc->dev_idx);
}
if (nr_unmap <= 1)
return 0;
return nr_unmap * 100 / nr_zones;
}
/*
* Test if reclaim is necessary.
*/
static bool dmz_should_reclaim(struct dmz_reclaim *zrc, unsigned int p_unmap)
{
unsigned int nr_reclaim;
nr_reclaim = dmz_nr_rnd_zones(zrc->metadata, zrc->dev_idx);
if (dmz_nr_cache_zones(zrc->metadata)) {
/*
* The first device in a multi-device
* setup only contains cache zones, so
* never start reclaim there.
*/
if (zrc->dev_idx == 0)
return false;
nr_reclaim += dmz_nr_cache_zones(zrc->metadata);
}
/* Reclaim when idle */
if (dmz_target_idle(zrc) && nr_reclaim)
return true;
/* If there are still plenty of cache zones, do not reclaim */
if (p_unmap >= DMZ_RECLAIM_HIGH_UNMAP_ZONES)
return false;
/*
* If the percentage of unmapped cache zones is low,
* reclaim even if the target is busy.
*/
return p_unmap <= DMZ_RECLAIM_LOW_UNMAP_ZONES;
}
/*
* Reclaim work function.
*/
static void dmz_reclaim_work(struct work_struct *work)
{
struct dmz_reclaim *zrc = container_of(work, struct dmz_reclaim, work.work);
struct dmz_metadata *zmd = zrc->metadata;
unsigned int p_unmap;
int ret;
if (dmz_dev_is_dying(zmd))
return;
p_unmap = dmz_reclaim_percentage(zrc);
if (!dmz_should_reclaim(zrc, p_unmap)) {
mod_delayed_work(zrc->wq, &zrc->work, DMZ_IDLE_PERIOD);
return;
}
/*
* We need to start reclaiming random zones: set up zone copy
* throttling to either go fast if we are very low on random zones
* and slower if there are still some free random zones to avoid
* as much as possible to negatively impact the user workload.
*/
if (dmz_target_idle(zrc) || p_unmap < DMZ_RECLAIM_LOW_UNMAP_ZONES / 2) {
/* Idle or very low percentage: go fast */
zrc->kc_throttle.throttle = 100;
} else {
/* Busy but we still have some random zone: throttle */
zrc->kc_throttle.throttle = min(75U, 100U - p_unmap / 2);
}
DMDEBUG("(%s/%u): Reclaim (%u): %s, %u%% free zones (%u/%u cache %u/%u random)",
dmz_metadata_label(zmd), zrc->dev_idx,
zrc->kc_throttle.throttle,
(dmz_target_idle(zrc) ? "Idle" : "Busy"),
p_unmap, dmz_nr_unmap_cache_zones(zmd),
dmz_nr_cache_zones(zmd),
dmz_nr_unmap_rnd_zones(zmd, zrc->dev_idx),
dmz_nr_rnd_zones(zmd, zrc->dev_idx));
ret = dmz_do_reclaim(zrc);
if (ret && ret != -EINTR) {
if (!dmz_check_dev(zmd))
return;
}
dmz_schedule_reclaim(zrc);
}
/*
* Initialize reclaim.
*/
int dmz_ctr_reclaim(struct dmz_metadata *zmd,
struct dmz_reclaim **reclaim, int idx)
{
struct dmz_reclaim *zrc;
int ret;
zrc = kzalloc(sizeof(struct dmz_reclaim), GFP_KERNEL);
if (!zrc)
return -ENOMEM;
zrc->metadata = zmd;
zrc->atime = jiffies;
zrc->dev_idx = idx;
/* Reclaim kcopyd client */
zrc->kc = dm_kcopyd_client_create(&zrc->kc_throttle);
if (IS_ERR(zrc->kc)) {
ret = PTR_ERR(zrc->kc);
zrc->kc = NULL;
goto err;
}
/* Reclaim work */
INIT_DELAYED_WORK(&zrc->work, dmz_reclaim_work);
zrc->wq = alloc_ordered_workqueue("dmz_rwq_%s_%d", WQ_MEM_RECLAIM,
dmz_metadata_label(zmd), idx);
if (!zrc->wq) {
ret = -ENOMEM;
goto err;
}
*reclaim = zrc;
queue_delayed_work(zrc->wq, &zrc->work, 0);
return 0;
err:
if (zrc->kc)
dm_kcopyd_client_destroy(zrc->kc);
kfree(zrc);
return ret;
}
/*
* Terminate reclaim.
*/
void dmz_dtr_reclaim(struct dmz_reclaim *zrc)
{
cancel_delayed_work_sync(&zrc->work);
destroy_workqueue(zrc->wq);
dm_kcopyd_client_destroy(zrc->kc);
kfree(zrc);
}
/*
* Suspend reclaim.
*/
void dmz_suspend_reclaim(struct dmz_reclaim *zrc)
{
cancel_delayed_work_sync(&zrc->work);
}
/*
* Resume reclaim.
*/
void dmz_resume_reclaim(struct dmz_reclaim *zrc)
{
queue_delayed_work(zrc->wq, &zrc->work, DMZ_IDLE_PERIOD);
}
/*
* BIO accounting.
*/
void dmz_reclaim_bio_acc(struct dmz_reclaim *zrc)
{
zrc->atime = jiffies;
}
/*
* Start reclaim if necessary.
*/
void dmz_schedule_reclaim(struct dmz_reclaim *zrc)
{
unsigned int p_unmap = dmz_reclaim_percentage(zrc);
if (dmz_should_reclaim(zrc, p_unmap))
mod_delayed_work(zrc->wq, &zrc->work, 0);
}
| linux-master | drivers/md/dm-zoned-reclaim.c |
// SPDX-License-Identifier: GPL-2.0-only
#include <linux/errno.h>
#include <linux/numa.h>
#include <linux/slab.h>
#include <linux/rculist.h>
#include <linux/threads.h>
#include <linux/preempt.h>
#include <linux/irqflags.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/device-mapper.h>
#include "dm-core.h"
#include "dm-stats.h"
#define DM_MSG_PREFIX "stats"
static int dm_stat_need_rcu_barrier;
/*
* Using 64-bit values to avoid overflow (which is a
* problem that block/genhd.c's IO accounting has).
*/
struct dm_stat_percpu {
unsigned long long sectors[2];
unsigned long long ios[2];
unsigned long long merges[2];
unsigned long long ticks[2];
unsigned long long io_ticks[2];
unsigned long long io_ticks_total;
unsigned long long time_in_queue;
unsigned long long *histogram;
};
struct dm_stat_shared {
atomic_t in_flight[2];
unsigned long long stamp;
struct dm_stat_percpu tmp;
};
struct dm_stat {
struct list_head list_entry;
int id;
unsigned int stat_flags;
size_t n_entries;
sector_t start;
sector_t end;
sector_t step;
unsigned int n_histogram_entries;
unsigned long long *histogram_boundaries;
const char *program_id;
const char *aux_data;
struct rcu_head rcu_head;
size_t shared_alloc_size;
size_t percpu_alloc_size;
size_t histogram_alloc_size;
struct dm_stat_percpu *stat_percpu[NR_CPUS];
struct dm_stat_shared stat_shared[];
};
#define STAT_PRECISE_TIMESTAMPS 1
struct dm_stats_last_position {
sector_t last_sector;
unsigned int last_rw;
};
/*
* A typo on the command line could possibly make the kernel run out of memory
* and crash. To prevent the crash we account all used memory. We fail if we
* exhaust 1/4 of all memory or 1/2 of vmalloc space.
*/
#define DM_STATS_MEMORY_FACTOR 4
#define DM_STATS_VMALLOC_FACTOR 2
static DEFINE_SPINLOCK(shared_memory_lock);
static unsigned long shared_memory_amount;
static bool __check_shared_memory(size_t alloc_size)
{
size_t a;
a = shared_memory_amount + alloc_size;
if (a < shared_memory_amount)
return false;
if (a >> PAGE_SHIFT > totalram_pages() / DM_STATS_MEMORY_FACTOR)
return false;
#ifdef CONFIG_MMU
if (a > (VMALLOC_END - VMALLOC_START) / DM_STATS_VMALLOC_FACTOR)
return false;
#endif
return true;
}
static bool check_shared_memory(size_t alloc_size)
{
bool ret;
spin_lock_irq(&shared_memory_lock);
ret = __check_shared_memory(alloc_size);
spin_unlock_irq(&shared_memory_lock);
return ret;
}
static bool claim_shared_memory(size_t alloc_size)
{
spin_lock_irq(&shared_memory_lock);
if (!__check_shared_memory(alloc_size)) {
spin_unlock_irq(&shared_memory_lock);
return false;
}
shared_memory_amount += alloc_size;
spin_unlock_irq(&shared_memory_lock);
return true;
}
static void free_shared_memory(size_t alloc_size)
{
unsigned long flags;
spin_lock_irqsave(&shared_memory_lock, flags);
if (WARN_ON_ONCE(shared_memory_amount < alloc_size)) {
spin_unlock_irqrestore(&shared_memory_lock, flags);
DMCRIT("Memory usage accounting bug.");
return;
}
shared_memory_amount -= alloc_size;
spin_unlock_irqrestore(&shared_memory_lock, flags);
}
static void *dm_kvzalloc(size_t alloc_size, int node)
{
void *p;
if (!claim_shared_memory(alloc_size))
return NULL;
p = kvzalloc_node(alloc_size, GFP_KERNEL | __GFP_NOMEMALLOC, node);
if (p)
return p;
free_shared_memory(alloc_size);
return NULL;
}
static void dm_kvfree(void *ptr, size_t alloc_size)
{
if (!ptr)
return;
free_shared_memory(alloc_size);
kvfree(ptr);
}
static void dm_stat_free(struct rcu_head *head)
{
int cpu;
struct dm_stat *s = container_of(head, struct dm_stat, rcu_head);
kfree(s->histogram_boundaries);
kfree(s->program_id);
kfree(s->aux_data);
for_each_possible_cpu(cpu) {
dm_kvfree(s->stat_percpu[cpu][0].histogram, s->histogram_alloc_size);
dm_kvfree(s->stat_percpu[cpu], s->percpu_alloc_size);
}
dm_kvfree(s->stat_shared[0].tmp.histogram, s->histogram_alloc_size);
dm_kvfree(s, s->shared_alloc_size);
}
static int dm_stat_in_flight(struct dm_stat_shared *shared)
{
return atomic_read(&shared->in_flight[READ]) +
atomic_read(&shared->in_flight[WRITE]);
}
int dm_stats_init(struct dm_stats *stats)
{
int cpu;
struct dm_stats_last_position *last;
mutex_init(&stats->mutex);
INIT_LIST_HEAD(&stats->list);
stats->precise_timestamps = false;
stats->last = alloc_percpu(struct dm_stats_last_position);
if (!stats->last)
return -ENOMEM;
for_each_possible_cpu(cpu) {
last = per_cpu_ptr(stats->last, cpu);
last->last_sector = (sector_t)ULLONG_MAX;
last->last_rw = UINT_MAX;
}
return 0;
}
void dm_stats_cleanup(struct dm_stats *stats)
{
size_t ni;
struct dm_stat *s;
struct dm_stat_shared *shared;
while (!list_empty(&stats->list)) {
s = container_of(stats->list.next, struct dm_stat, list_entry);
list_del(&s->list_entry);
for (ni = 0; ni < s->n_entries; ni++) {
shared = &s->stat_shared[ni];
if (WARN_ON(dm_stat_in_flight(shared))) {
DMCRIT("leaked in-flight counter at index %lu "
"(start %llu, end %llu, step %llu): reads %d, writes %d",
(unsigned long)ni,
(unsigned long long)s->start,
(unsigned long long)s->end,
(unsigned long long)s->step,
atomic_read(&shared->in_flight[READ]),
atomic_read(&shared->in_flight[WRITE]));
}
cond_resched();
}
dm_stat_free(&s->rcu_head);
}
free_percpu(stats->last);
mutex_destroy(&stats->mutex);
}
static void dm_stats_recalc_precise_timestamps(struct dm_stats *stats)
{
struct list_head *l;
struct dm_stat *tmp_s;
bool precise_timestamps = false;
list_for_each(l, &stats->list) {
tmp_s = container_of(l, struct dm_stat, list_entry);
if (tmp_s->stat_flags & STAT_PRECISE_TIMESTAMPS) {
precise_timestamps = true;
break;
}
}
stats->precise_timestamps = precise_timestamps;
}
static int dm_stats_create(struct dm_stats *stats, sector_t start, sector_t end,
sector_t step, unsigned int stat_flags,
unsigned int n_histogram_entries,
unsigned long long *histogram_boundaries,
const char *program_id, const char *aux_data,
void (*suspend_callback)(struct mapped_device *),
void (*resume_callback)(struct mapped_device *),
struct mapped_device *md)
{
struct list_head *l;
struct dm_stat *s, *tmp_s;
sector_t n_entries;
size_t ni;
size_t shared_alloc_size;
size_t percpu_alloc_size;
size_t histogram_alloc_size;
struct dm_stat_percpu *p;
int cpu;
int ret_id;
int r;
if (end < start || !step)
return -EINVAL;
n_entries = end - start;
if (dm_sector_div64(n_entries, step))
n_entries++;
if (n_entries != (size_t)n_entries || !(size_t)(n_entries + 1))
return -EOVERFLOW;
shared_alloc_size = struct_size(s, stat_shared, n_entries);
if ((shared_alloc_size - sizeof(struct dm_stat)) / sizeof(struct dm_stat_shared) != n_entries)
return -EOVERFLOW;
percpu_alloc_size = (size_t)n_entries * sizeof(struct dm_stat_percpu);
if (percpu_alloc_size / sizeof(struct dm_stat_percpu) != n_entries)
return -EOVERFLOW;
histogram_alloc_size = (n_histogram_entries + 1) * (size_t)n_entries * sizeof(unsigned long long);
if (histogram_alloc_size / (n_histogram_entries + 1) != (size_t)n_entries * sizeof(unsigned long long))
return -EOVERFLOW;
if (!check_shared_memory(shared_alloc_size + histogram_alloc_size +
num_possible_cpus() * (percpu_alloc_size + histogram_alloc_size)))
return -ENOMEM;
s = dm_kvzalloc(shared_alloc_size, NUMA_NO_NODE);
if (!s)
return -ENOMEM;
s->stat_flags = stat_flags;
s->n_entries = n_entries;
s->start = start;
s->end = end;
s->step = step;
s->shared_alloc_size = shared_alloc_size;
s->percpu_alloc_size = percpu_alloc_size;
s->histogram_alloc_size = histogram_alloc_size;
s->n_histogram_entries = n_histogram_entries;
s->histogram_boundaries = kmemdup(histogram_boundaries,
s->n_histogram_entries * sizeof(unsigned long long), GFP_KERNEL);
if (!s->histogram_boundaries) {
r = -ENOMEM;
goto out;
}
s->program_id = kstrdup(program_id, GFP_KERNEL);
if (!s->program_id) {
r = -ENOMEM;
goto out;
}
s->aux_data = kstrdup(aux_data, GFP_KERNEL);
if (!s->aux_data) {
r = -ENOMEM;
goto out;
}
for (ni = 0; ni < n_entries; ni++) {
atomic_set(&s->stat_shared[ni].in_flight[READ], 0);
atomic_set(&s->stat_shared[ni].in_flight[WRITE], 0);
cond_resched();
}
if (s->n_histogram_entries) {
unsigned long long *hi;
hi = dm_kvzalloc(s->histogram_alloc_size, NUMA_NO_NODE);
if (!hi) {
r = -ENOMEM;
goto out;
}
for (ni = 0; ni < n_entries; ni++) {
s->stat_shared[ni].tmp.histogram = hi;
hi += s->n_histogram_entries + 1;
cond_resched();
}
}
for_each_possible_cpu(cpu) {
p = dm_kvzalloc(percpu_alloc_size, cpu_to_node(cpu));
if (!p) {
r = -ENOMEM;
goto out;
}
s->stat_percpu[cpu] = p;
if (s->n_histogram_entries) {
unsigned long long *hi;
hi = dm_kvzalloc(s->histogram_alloc_size, cpu_to_node(cpu));
if (!hi) {
r = -ENOMEM;
goto out;
}
for (ni = 0; ni < n_entries; ni++) {
p[ni].histogram = hi;
hi += s->n_histogram_entries + 1;
cond_resched();
}
}
}
/*
* Suspend/resume to make sure there is no i/o in flight,
* so that newly created statistics will be exact.
*
* (note: we couldn't suspend earlier because we must not
* allocate memory while suspended)
*/
suspend_callback(md);
mutex_lock(&stats->mutex);
s->id = 0;
list_for_each(l, &stats->list) {
tmp_s = container_of(l, struct dm_stat, list_entry);
if (WARN_ON(tmp_s->id < s->id)) {
r = -EINVAL;
goto out_unlock_resume;
}
if (tmp_s->id > s->id)
break;
if (unlikely(s->id == INT_MAX)) {
r = -ENFILE;
goto out_unlock_resume;
}
s->id++;
}
ret_id = s->id;
list_add_tail_rcu(&s->list_entry, l);
dm_stats_recalc_precise_timestamps(stats);
if (!static_key_enabled(&stats_enabled.key))
static_branch_enable(&stats_enabled);
mutex_unlock(&stats->mutex);
resume_callback(md);
return ret_id;
out_unlock_resume:
mutex_unlock(&stats->mutex);
resume_callback(md);
out:
dm_stat_free(&s->rcu_head);
return r;
}
static struct dm_stat *__dm_stats_find(struct dm_stats *stats, int id)
{
struct dm_stat *s;
list_for_each_entry(s, &stats->list, list_entry) {
if (s->id > id)
break;
if (s->id == id)
return s;
}
return NULL;
}
static int dm_stats_delete(struct dm_stats *stats, int id)
{
struct dm_stat *s;
int cpu;
mutex_lock(&stats->mutex);
s = __dm_stats_find(stats, id);
if (!s) {
mutex_unlock(&stats->mutex);
return -ENOENT;
}
list_del_rcu(&s->list_entry);
dm_stats_recalc_precise_timestamps(stats);
mutex_unlock(&stats->mutex);
/*
* vfree can't be called from RCU callback
*/
for_each_possible_cpu(cpu)
if (is_vmalloc_addr(s->stat_percpu) ||
is_vmalloc_addr(s->stat_percpu[cpu][0].histogram))
goto do_sync_free;
if (is_vmalloc_addr(s) ||
is_vmalloc_addr(s->stat_shared[0].tmp.histogram)) {
do_sync_free:
synchronize_rcu_expedited();
dm_stat_free(&s->rcu_head);
} else {
WRITE_ONCE(dm_stat_need_rcu_barrier, 1);
call_rcu(&s->rcu_head, dm_stat_free);
}
return 0;
}
static int dm_stats_list(struct dm_stats *stats, const char *program,
char *result, unsigned int maxlen)
{
struct dm_stat *s;
sector_t len;
unsigned int sz = 0;
/*
* Output format:
* <region_id>: <start_sector>+<length> <step> <program_id> <aux_data>
*/
mutex_lock(&stats->mutex);
list_for_each_entry(s, &stats->list, list_entry) {
if (!program || !strcmp(program, s->program_id)) {
len = s->end - s->start;
DMEMIT("%d: %llu+%llu %llu %s %s", s->id,
(unsigned long long)s->start,
(unsigned long long)len,
(unsigned long long)s->step,
s->program_id,
s->aux_data);
if (s->stat_flags & STAT_PRECISE_TIMESTAMPS)
DMEMIT(" precise_timestamps");
if (s->n_histogram_entries) {
unsigned int i;
DMEMIT(" histogram:");
for (i = 0; i < s->n_histogram_entries; i++) {
if (i)
DMEMIT(",");
DMEMIT("%llu", s->histogram_boundaries[i]);
}
}
DMEMIT("\n");
}
cond_resched();
}
mutex_unlock(&stats->mutex);
return 1;
}
static void dm_stat_round(struct dm_stat *s, struct dm_stat_shared *shared,
struct dm_stat_percpu *p)
{
/*
* This is racy, but so is part_round_stats_single.
*/
unsigned long long now, difference;
unsigned int in_flight_read, in_flight_write;
if (likely(!(s->stat_flags & STAT_PRECISE_TIMESTAMPS)))
now = jiffies;
else
now = ktime_to_ns(ktime_get());
difference = now - shared->stamp;
if (!difference)
return;
in_flight_read = (unsigned int)atomic_read(&shared->in_flight[READ]);
in_flight_write = (unsigned int)atomic_read(&shared->in_flight[WRITE]);
if (in_flight_read)
p->io_ticks[READ] += difference;
if (in_flight_write)
p->io_ticks[WRITE] += difference;
if (in_flight_read + in_flight_write) {
p->io_ticks_total += difference;
p->time_in_queue += (in_flight_read + in_flight_write) * difference;
}
shared->stamp = now;
}
static void dm_stat_for_entry(struct dm_stat *s, size_t entry,
int idx, sector_t len,
struct dm_stats_aux *stats_aux, bool end,
unsigned long duration_jiffies)
{
struct dm_stat_shared *shared = &s->stat_shared[entry];
struct dm_stat_percpu *p;
/*
* For strict correctness we should use local_irq_save/restore
* instead of preempt_disable/enable.
*
* preempt_disable/enable is racy if the driver finishes bios
* from non-interrupt context as well as from interrupt context
* or from more different interrupts.
*
* On 64-bit architectures the race only results in not counting some
* events, so it is acceptable. On 32-bit architectures the race could
* cause the counter going off by 2^32, so we need to do proper locking
* there.
*
* part_stat_lock()/part_stat_unlock() have this race too.
*/
#if BITS_PER_LONG == 32
unsigned long flags;
local_irq_save(flags);
#else
preempt_disable();
#endif
p = &s->stat_percpu[smp_processor_id()][entry];
if (!end) {
dm_stat_round(s, shared, p);
atomic_inc(&shared->in_flight[idx]);
} else {
unsigned long long duration;
dm_stat_round(s, shared, p);
atomic_dec(&shared->in_flight[idx]);
p->sectors[idx] += len;
p->ios[idx] += 1;
p->merges[idx] += stats_aux->merged;
if (!(s->stat_flags & STAT_PRECISE_TIMESTAMPS)) {
p->ticks[idx] += duration_jiffies;
duration = jiffies_to_msecs(duration_jiffies);
} else {
p->ticks[idx] += stats_aux->duration_ns;
duration = stats_aux->duration_ns;
}
if (s->n_histogram_entries) {
unsigned int lo = 0, hi = s->n_histogram_entries + 1;
while (lo + 1 < hi) {
unsigned int mid = (lo + hi) / 2;
if (s->histogram_boundaries[mid - 1] > duration)
hi = mid;
else
lo = mid;
}
p->histogram[lo]++;
}
}
#if BITS_PER_LONG == 32
local_irq_restore(flags);
#else
preempt_enable();
#endif
}
static void __dm_stat_bio(struct dm_stat *s, int bi_rw,
sector_t bi_sector, sector_t end_sector,
bool end, unsigned long duration_jiffies,
struct dm_stats_aux *stats_aux)
{
sector_t rel_sector, offset, todo, fragment_len;
size_t entry;
if (end_sector <= s->start || bi_sector >= s->end)
return;
if (unlikely(bi_sector < s->start)) {
rel_sector = 0;
todo = end_sector - s->start;
} else {
rel_sector = bi_sector - s->start;
todo = end_sector - bi_sector;
}
if (unlikely(end_sector > s->end))
todo -= (end_sector - s->end);
offset = dm_sector_div64(rel_sector, s->step);
entry = rel_sector;
do {
if (WARN_ON_ONCE(entry >= s->n_entries)) {
DMCRIT("Invalid area access in region id %d", s->id);
return;
}
fragment_len = todo;
if (fragment_len > s->step - offset)
fragment_len = s->step - offset;
dm_stat_for_entry(s, entry, bi_rw, fragment_len,
stats_aux, end, duration_jiffies);
todo -= fragment_len;
entry++;
offset = 0;
} while (unlikely(todo != 0));
}
void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw,
sector_t bi_sector, unsigned int bi_sectors, bool end,
unsigned long start_time,
struct dm_stats_aux *stats_aux)
{
struct dm_stat *s;
sector_t end_sector;
struct dm_stats_last_position *last;
bool got_precise_time;
unsigned long duration_jiffies = 0;
if (unlikely(!bi_sectors))
return;
end_sector = bi_sector + bi_sectors;
if (!end) {
/*
* A race condition can at worst result in the merged flag being
* misrepresented, so we don't have to disable preemption here.
*/
last = raw_cpu_ptr(stats->last);
stats_aux->merged =
(bi_sector == (READ_ONCE(last->last_sector) &&
((bi_rw == WRITE) ==
(READ_ONCE(last->last_rw) == WRITE))
));
WRITE_ONCE(last->last_sector, end_sector);
WRITE_ONCE(last->last_rw, bi_rw);
} else
duration_jiffies = jiffies - start_time;
rcu_read_lock();
got_precise_time = false;
list_for_each_entry_rcu(s, &stats->list, list_entry) {
if (s->stat_flags & STAT_PRECISE_TIMESTAMPS && !got_precise_time) {
/* start (!end) duration_ns is set by DM core's alloc_io() */
if (end)
stats_aux->duration_ns = ktime_to_ns(ktime_get()) - stats_aux->duration_ns;
got_precise_time = true;
}
__dm_stat_bio(s, bi_rw, bi_sector, end_sector, end, duration_jiffies, stats_aux);
}
rcu_read_unlock();
}
static void __dm_stat_init_temporary_percpu_totals(struct dm_stat_shared *shared,
struct dm_stat *s, size_t x)
{
int cpu;
struct dm_stat_percpu *p;
local_irq_disable();
p = &s->stat_percpu[smp_processor_id()][x];
dm_stat_round(s, shared, p);
local_irq_enable();
shared->tmp.sectors[READ] = 0;
shared->tmp.sectors[WRITE] = 0;
shared->tmp.ios[READ] = 0;
shared->tmp.ios[WRITE] = 0;
shared->tmp.merges[READ] = 0;
shared->tmp.merges[WRITE] = 0;
shared->tmp.ticks[READ] = 0;
shared->tmp.ticks[WRITE] = 0;
shared->tmp.io_ticks[READ] = 0;
shared->tmp.io_ticks[WRITE] = 0;
shared->tmp.io_ticks_total = 0;
shared->tmp.time_in_queue = 0;
if (s->n_histogram_entries)
memset(shared->tmp.histogram, 0, (s->n_histogram_entries + 1) * sizeof(unsigned long long));
for_each_possible_cpu(cpu) {
p = &s->stat_percpu[cpu][x];
shared->tmp.sectors[READ] += READ_ONCE(p->sectors[READ]);
shared->tmp.sectors[WRITE] += READ_ONCE(p->sectors[WRITE]);
shared->tmp.ios[READ] += READ_ONCE(p->ios[READ]);
shared->tmp.ios[WRITE] += READ_ONCE(p->ios[WRITE]);
shared->tmp.merges[READ] += READ_ONCE(p->merges[READ]);
shared->tmp.merges[WRITE] += READ_ONCE(p->merges[WRITE]);
shared->tmp.ticks[READ] += READ_ONCE(p->ticks[READ]);
shared->tmp.ticks[WRITE] += READ_ONCE(p->ticks[WRITE]);
shared->tmp.io_ticks[READ] += READ_ONCE(p->io_ticks[READ]);
shared->tmp.io_ticks[WRITE] += READ_ONCE(p->io_ticks[WRITE]);
shared->tmp.io_ticks_total += READ_ONCE(p->io_ticks_total);
shared->tmp.time_in_queue += READ_ONCE(p->time_in_queue);
if (s->n_histogram_entries) {
unsigned int i;
for (i = 0; i < s->n_histogram_entries + 1; i++)
shared->tmp.histogram[i] += READ_ONCE(p->histogram[i]);
}
}
}
static void __dm_stat_clear(struct dm_stat *s, size_t idx_start, size_t idx_end,
bool init_tmp_percpu_totals)
{
size_t x;
struct dm_stat_shared *shared;
struct dm_stat_percpu *p;
for (x = idx_start; x < idx_end; x++) {
shared = &s->stat_shared[x];
if (init_tmp_percpu_totals)
__dm_stat_init_temporary_percpu_totals(shared, s, x);
local_irq_disable();
p = &s->stat_percpu[smp_processor_id()][x];
p->sectors[READ] -= shared->tmp.sectors[READ];
p->sectors[WRITE] -= shared->tmp.sectors[WRITE];
p->ios[READ] -= shared->tmp.ios[READ];
p->ios[WRITE] -= shared->tmp.ios[WRITE];
p->merges[READ] -= shared->tmp.merges[READ];
p->merges[WRITE] -= shared->tmp.merges[WRITE];
p->ticks[READ] -= shared->tmp.ticks[READ];
p->ticks[WRITE] -= shared->tmp.ticks[WRITE];
p->io_ticks[READ] -= shared->tmp.io_ticks[READ];
p->io_ticks[WRITE] -= shared->tmp.io_ticks[WRITE];
p->io_ticks_total -= shared->tmp.io_ticks_total;
p->time_in_queue -= shared->tmp.time_in_queue;
local_irq_enable();
if (s->n_histogram_entries) {
unsigned int i;
for (i = 0; i < s->n_histogram_entries + 1; i++) {
local_irq_disable();
p = &s->stat_percpu[smp_processor_id()][x];
p->histogram[i] -= shared->tmp.histogram[i];
local_irq_enable();
}
}
cond_resched();
}
}
static int dm_stats_clear(struct dm_stats *stats, int id)
{
struct dm_stat *s;
mutex_lock(&stats->mutex);
s = __dm_stats_find(stats, id);
if (!s) {
mutex_unlock(&stats->mutex);
return -ENOENT;
}
__dm_stat_clear(s, 0, s->n_entries, true);
mutex_unlock(&stats->mutex);
return 1;
}
/*
* This is like jiffies_to_msec, but works for 64-bit values.
*/
static unsigned long long dm_jiffies_to_msec64(struct dm_stat *s, unsigned long long j)
{
unsigned long long result;
unsigned int mult;
if (s->stat_flags & STAT_PRECISE_TIMESTAMPS)
return j;
result = 0;
if (j)
result = jiffies_to_msecs(j & 0x3fffff);
if (j >= 1 << 22) {
mult = jiffies_to_msecs(1 << 22);
result += (unsigned long long)mult * (unsigned long long)jiffies_to_msecs((j >> 22) & 0x3fffff);
}
if (j >= 1ULL << 44)
result += (unsigned long long)mult * (unsigned long long)mult * (unsigned long long)jiffies_to_msecs(j >> 44);
return result;
}
static int dm_stats_print(struct dm_stats *stats, int id,
size_t idx_start, size_t idx_len,
bool clear, char *result, unsigned int maxlen)
{
unsigned int sz = 0;
struct dm_stat *s;
size_t x;
sector_t start, end, step;
size_t idx_end;
struct dm_stat_shared *shared;
/*
* Output format:
* <start_sector>+<length> counters
*/
mutex_lock(&stats->mutex);
s = __dm_stats_find(stats, id);
if (!s) {
mutex_unlock(&stats->mutex);
return -ENOENT;
}
idx_end = idx_start + idx_len;
if (idx_end < idx_start ||
idx_end > s->n_entries)
idx_end = s->n_entries;
if (idx_start > idx_end)
idx_start = idx_end;
step = s->step;
start = s->start + (step * idx_start);
for (x = idx_start; x < idx_end; x++, start = end) {
shared = &s->stat_shared[x];
end = start + step;
if (unlikely(end > s->end))
end = s->end;
__dm_stat_init_temporary_percpu_totals(shared, s, x);
DMEMIT("%llu+%llu %llu %llu %llu %llu %llu %llu %llu %llu %d %llu %llu %llu %llu",
(unsigned long long)start,
(unsigned long long)step,
shared->tmp.ios[READ],
shared->tmp.merges[READ],
shared->tmp.sectors[READ],
dm_jiffies_to_msec64(s, shared->tmp.ticks[READ]),
shared->tmp.ios[WRITE],
shared->tmp.merges[WRITE],
shared->tmp.sectors[WRITE],
dm_jiffies_to_msec64(s, shared->tmp.ticks[WRITE]),
dm_stat_in_flight(shared),
dm_jiffies_to_msec64(s, shared->tmp.io_ticks_total),
dm_jiffies_to_msec64(s, shared->tmp.time_in_queue),
dm_jiffies_to_msec64(s, shared->tmp.io_ticks[READ]),
dm_jiffies_to_msec64(s, shared->tmp.io_ticks[WRITE]));
if (s->n_histogram_entries) {
unsigned int i;
for (i = 0; i < s->n_histogram_entries + 1; i++)
DMEMIT("%s%llu", !i ? " " : ":", shared->tmp.histogram[i]);
}
DMEMIT("\n");
if (unlikely(sz + 1 >= maxlen))
goto buffer_overflow;
cond_resched();
}
if (clear)
__dm_stat_clear(s, idx_start, idx_end, false);
buffer_overflow:
mutex_unlock(&stats->mutex);
return 1;
}
static int dm_stats_set_aux(struct dm_stats *stats, int id, const char *aux_data)
{
struct dm_stat *s;
const char *new_aux_data;
mutex_lock(&stats->mutex);
s = __dm_stats_find(stats, id);
if (!s) {
mutex_unlock(&stats->mutex);
return -ENOENT;
}
new_aux_data = kstrdup(aux_data, GFP_KERNEL);
if (!new_aux_data) {
mutex_unlock(&stats->mutex);
return -ENOMEM;
}
kfree(s->aux_data);
s->aux_data = new_aux_data;
mutex_unlock(&stats->mutex);
return 0;
}
static int parse_histogram(const char *h, unsigned int *n_histogram_entries,
unsigned long long **histogram_boundaries)
{
const char *q;
unsigned int n;
unsigned long long last;
*n_histogram_entries = 1;
for (q = h; *q; q++)
if (*q == ',')
(*n_histogram_entries)++;
*histogram_boundaries = kmalloc_array(*n_histogram_entries,
sizeof(unsigned long long),
GFP_KERNEL);
if (!*histogram_boundaries)
return -ENOMEM;
n = 0;
last = 0;
while (1) {
unsigned long long hi;
int s;
char ch;
s = sscanf(h, "%llu%c", &hi, &ch);
if (!s || (s == 2 && ch != ','))
return -EINVAL;
if (hi <= last)
return -EINVAL;
last = hi;
(*histogram_boundaries)[n] = hi;
if (s == 1)
return 0;
h = strchr(h, ',') + 1;
n++;
}
}
static int message_stats_create(struct mapped_device *md,
unsigned int argc, char **argv,
char *result, unsigned int maxlen)
{
int r;
int id;
char dummy;
unsigned long long start, end, len, step;
unsigned int divisor;
const char *program_id, *aux_data;
unsigned int stat_flags = 0;
unsigned int n_histogram_entries = 0;
unsigned long long *histogram_boundaries = NULL;
struct dm_arg_set as, as_backup;
const char *a;
unsigned int feature_args;
/*
* Input format:
* <range> <step> [<extra_parameters> <parameters>] [<program_id> [<aux_data>]]
*/
if (argc < 3)
goto ret_einval;
as.argc = argc;
as.argv = argv;
dm_consume_args(&as, 1);
a = dm_shift_arg(&as);
if (!strcmp(a, "-")) {
start = 0;
len = dm_get_size(md);
if (!len)
len = 1;
} else if (sscanf(a, "%llu+%llu%c", &start, &len, &dummy) != 2 ||
start != (sector_t)start || len != (sector_t)len)
goto ret_einval;
end = start + len;
if (start >= end)
goto ret_einval;
a = dm_shift_arg(&as);
if (sscanf(a, "/%u%c", &divisor, &dummy) == 1) {
if (!divisor)
return -EINVAL;
step = end - start;
if (do_div(step, divisor))
step++;
if (!step)
step = 1;
} else if (sscanf(a, "%llu%c", &step, &dummy) != 1 ||
step != (sector_t)step || !step)
goto ret_einval;
as_backup = as;
a = dm_shift_arg(&as);
if (a && sscanf(a, "%u%c", &feature_args, &dummy) == 1) {
while (feature_args--) {
a = dm_shift_arg(&as);
if (!a)
goto ret_einval;
if (!strcasecmp(a, "precise_timestamps"))
stat_flags |= STAT_PRECISE_TIMESTAMPS;
else if (!strncasecmp(a, "histogram:", 10)) {
if (n_histogram_entries)
goto ret_einval;
r = parse_histogram(a + 10, &n_histogram_entries, &histogram_boundaries);
if (r)
goto ret;
} else
goto ret_einval;
}
} else {
as = as_backup;
}
program_id = "-";
aux_data = "-";
a = dm_shift_arg(&as);
if (a)
program_id = a;
a = dm_shift_arg(&as);
if (a)
aux_data = a;
if (as.argc)
goto ret_einval;
/*
* If a buffer overflow happens after we created the region,
* it's too late (the userspace would retry with a larger
* buffer, but the region id that caused the overflow is already
* leaked). So we must detect buffer overflow in advance.
*/
snprintf(result, maxlen, "%d", INT_MAX);
if (dm_message_test_buffer_overflow(result, maxlen)) {
r = 1;
goto ret;
}
id = dm_stats_create(dm_get_stats(md), start, end, step, stat_flags,
n_histogram_entries, histogram_boundaries, program_id, aux_data,
dm_internal_suspend_fast, dm_internal_resume_fast, md);
if (id < 0) {
r = id;
goto ret;
}
snprintf(result, maxlen, "%d", id);
r = 1;
goto ret;
ret_einval:
r = -EINVAL;
ret:
kfree(histogram_boundaries);
return r;
}
static int message_stats_delete(struct mapped_device *md,
unsigned int argc, char **argv)
{
int id;
char dummy;
if (argc != 2)
return -EINVAL;
if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
return -EINVAL;
return dm_stats_delete(dm_get_stats(md), id);
}
static int message_stats_clear(struct mapped_device *md,
unsigned int argc, char **argv)
{
int id;
char dummy;
if (argc != 2)
return -EINVAL;
if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
return -EINVAL;
return dm_stats_clear(dm_get_stats(md), id);
}
static int message_stats_list(struct mapped_device *md,
unsigned int argc, char **argv,
char *result, unsigned int maxlen)
{
int r;
const char *program = NULL;
if (argc < 1 || argc > 2)
return -EINVAL;
if (argc > 1) {
program = kstrdup(argv[1], GFP_KERNEL);
if (!program)
return -ENOMEM;
}
r = dm_stats_list(dm_get_stats(md), program, result, maxlen);
kfree(program);
return r;
}
static int message_stats_print(struct mapped_device *md,
unsigned int argc, char **argv, bool clear,
char *result, unsigned int maxlen)
{
int id;
char dummy;
unsigned long idx_start = 0, idx_len = ULONG_MAX;
if (argc != 2 && argc != 4)
return -EINVAL;
if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
return -EINVAL;
if (argc > 3) {
if (strcmp(argv[2], "-") &&
sscanf(argv[2], "%lu%c", &idx_start, &dummy) != 1)
return -EINVAL;
if (strcmp(argv[3], "-") &&
sscanf(argv[3], "%lu%c", &idx_len, &dummy) != 1)
return -EINVAL;
}
return dm_stats_print(dm_get_stats(md), id, idx_start, idx_len, clear,
result, maxlen);
}
static int message_stats_set_aux(struct mapped_device *md,
unsigned int argc, char **argv)
{
int id;
char dummy;
if (argc != 3)
return -EINVAL;
if (sscanf(argv[1], "%d%c", &id, &dummy) != 1 || id < 0)
return -EINVAL;
return dm_stats_set_aux(dm_get_stats(md), id, argv[2]);
}
int dm_stats_message(struct mapped_device *md, unsigned int argc, char **argv,
char *result, unsigned int maxlen)
{
int r;
/* All messages here must start with '@' */
if (!strcasecmp(argv[0], "@stats_create"))
r = message_stats_create(md, argc, argv, result, maxlen);
else if (!strcasecmp(argv[0], "@stats_delete"))
r = message_stats_delete(md, argc, argv);
else if (!strcasecmp(argv[0], "@stats_clear"))
r = message_stats_clear(md, argc, argv);
else if (!strcasecmp(argv[0], "@stats_list"))
r = message_stats_list(md, argc, argv, result, maxlen);
else if (!strcasecmp(argv[0], "@stats_print"))
r = message_stats_print(md, argc, argv, false, result, maxlen);
else if (!strcasecmp(argv[0], "@stats_print_clear"))
r = message_stats_print(md, argc, argv, true, result, maxlen);
else if (!strcasecmp(argv[0], "@stats_set_aux"))
r = message_stats_set_aux(md, argc, argv);
else
return 2; /* this wasn't a stats message */
if (r == -EINVAL)
DMCRIT("Invalid parameters for message %s", argv[0]);
return r;
}
int __init dm_statistics_init(void)
{
shared_memory_amount = 0;
dm_stat_need_rcu_barrier = 0;
return 0;
}
void dm_statistics_exit(void)
{
if (dm_stat_need_rcu_barrier)
rcu_barrier();
if (WARN_ON(shared_memory_amount))
DMCRIT("shared_memory_amount leaked: %lu", shared_memory_amount);
}
module_param_named(stats_current_allocated_bytes, shared_memory_amount, ulong, 0444);
MODULE_PARM_DESC(stats_current_allocated_bytes, "Memory currently used by statistics");
| linux-master | drivers/md/dm-stats.c |
// SPDX-License-Identifier: GPL-2.0-or-later
/*
raid0.c : Multiple Devices driver for Linux
Copyright (C) 1994-96 Marc ZYNGIER
<[email protected]> or
<[email protected]>
Copyright (C) 1999, 2000 Ingo Molnar, Red Hat
RAID-0 management functions.
*/
#include <linux/blkdev.h>
#include <linux/seq_file.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <trace/events/block.h>
#include "md.h"
#include "raid0.h"
#include "raid5.h"
static int default_layout = 0;
module_param(default_layout, int, 0644);
#define UNSUPPORTED_MDDEV_FLAGS \
((1L << MD_HAS_JOURNAL) | \
(1L << MD_JOURNAL_CLEAN) | \
(1L << MD_FAILFAST_SUPPORTED) |\
(1L << MD_HAS_PPL) | \
(1L << MD_HAS_MULTIPLE_PPLS))
/*
* inform the user of the raid configuration
*/
static void dump_zones(struct mddev *mddev)
{
int j, k;
sector_t zone_size = 0;
sector_t zone_start = 0;
struct r0conf *conf = mddev->private;
int raid_disks = conf->strip_zone[0].nb_dev;
pr_debug("md: RAID0 configuration for %s - %d zone%s\n",
mdname(mddev),
conf->nr_strip_zones, conf->nr_strip_zones==1?"":"s");
for (j = 0; j < conf->nr_strip_zones; j++) {
char line[200];
int len = 0;
for (k = 0; k < conf->strip_zone[j].nb_dev; k++)
len += scnprintf(line+len, 200-len, "%s%pg", k?"/":"",
conf->devlist[j * raid_disks + k]->bdev);
pr_debug("md: zone%d=[%s]\n", j, line);
zone_size = conf->strip_zone[j].zone_end - zone_start;
pr_debug(" zone-offset=%10lluKB, device-offset=%10lluKB, size=%10lluKB\n",
(unsigned long long)zone_start>>1,
(unsigned long long)conf->strip_zone[j].dev_start>>1,
(unsigned long long)zone_size>>1);
zone_start = conf->strip_zone[j].zone_end;
}
}
static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf)
{
int i, c, err;
sector_t curr_zone_end, sectors;
struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev;
struct strip_zone *zone;
int cnt;
struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
unsigned blksize = 512;
*private_conf = ERR_PTR(-ENOMEM);
if (!conf)
return -ENOMEM;
rdev_for_each(rdev1, mddev) {
pr_debug("md/raid0:%s: looking at %pg\n",
mdname(mddev),
rdev1->bdev);
c = 0;
/* round size to chunk_size */
sectors = rdev1->sectors;
sector_div(sectors, mddev->chunk_sectors);
rdev1->sectors = sectors * mddev->chunk_sectors;
blksize = max(blksize, queue_logical_block_size(
rdev1->bdev->bd_disk->queue));
rdev_for_each(rdev2, mddev) {
pr_debug("md/raid0:%s: comparing %pg(%llu)"
" with %pg(%llu)\n",
mdname(mddev),
rdev1->bdev,
(unsigned long long)rdev1->sectors,
rdev2->bdev,
(unsigned long long)rdev2->sectors);
if (rdev2 == rdev1) {
pr_debug("md/raid0:%s: END\n",
mdname(mddev));
break;
}
if (rdev2->sectors == rdev1->sectors) {
/*
* Not unique, don't count it as a new
* group
*/
pr_debug("md/raid0:%s: EQUAL\n",
mdname(mddev));
c = 1;
break;
}
pr_debug("md/raid0:%s: NOT EQUAL\n",
mdname(mddev));
}
if (!c) {
pr_debug("md/raid0:%s: ==> UNIQUE\n",
mdname(mddev));
conf->nr_strip_zones++;
pr_debug("md/raid0:%s: %d zones\n",
mdname(mddev), conf->nr_strip_zones);
}
}
pr_debug("md/raid0:%s: FINAL %d zones\n",
mdname(mddev), conf->nr_strip_zones);
/*
* now since we have the hard sector sizes, we can make sure
* chunk size is a multiple of that sector size
*/
if ((mddev->chunk_sectors << 9) % blksize) {
pr_warn("md/raid0:%s: chunk_size of %d not multiple of block size %d\n",
mdname(mddev),
mddev->chunk_sectors << 9, blksize);
err = -EINVAL;
goto abort;
}
err = -ENOMEM;
conf->strip_zone = kcalloc(conf->nr_strip_zones,
sizeof(struct strip_zone),
GFP_KERNEL);
if (!conf->strip_zone)
goto abort;
conf->devlist = kzalloc(array3_size(sizeof(struct md_rdev *),
conf->nr_strip_zones,
mddev->raid_disks),
GFP_KERNEL);
if (!conf->devlist)
goto abort;
/* The first zone must contain all devices, so here we check that
* there is a proper alignment of slots to devices and find them all
*/
zone = &conf->strip_zone[0];
cnt = 0;
smallest = NULL;
dev = conf->devlist;
err = -EINVAL;
rdev_for_each(rdev1, mddev) {
int j = rdev1->raid_disk;
if (mddev->level == 10) {
/* taking over a raid10-n2 array */
j /= 2;
rdev1->new_raid_disk = j;
}
if (mddev->level == 1) {
/* taiking over a raid1 array-
* we have only one active disk
*/
j = 0;
rdev1->new_raid_disk = j;
}
if (j < 0) {
pr_warn("md/raid0:%s: remove inactive devices before converting to RAID0\n",
mdname(mddev));
goto abort;
}
if (j >= mddev->raid_disks) {
pr_warn("md/raid0:%s: bad disk number %d - aborting!\n",
mdname(mddev), j);
goto abort;
}
if (dev[j]) {
pr_warn("md/raid0:%s: multiple devices for %d - aborting!\n",
mdname(mddev), j);
goto abort;
}
dev[j] = rdev1;
if (!smallest || (rdev1->sectors < smallest->sectors))
smallest = rdev1;
cnt++;
}
if (cnt != mddev->raid_disks) {
pr_warn("md/raid0:%s: too few disks (%d of %d) - aborting!\n",
mdname(mddev), cnt, mddev->raid_disks);
goto abort;
}
zone->nb_dev = cnt;
zone->zone_end = smallest->sectors * cnt;
curr_zone_end = zone->zone_end;
/* now do the other zones */
for (i = 1; i < conf->nr_strip_zones; i++)
{
int j;
zone = conf->strip_zone + i;
dev = conf->devlist + i * mddev->raid_disks;
pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i);
zone->dev_start = smallest->sectors;
smallest = NULL;
c = 0;
for (j=0; j<cnt; j++) {
rdev = conf->devlist[j];
if (rdev->sectors <= zone->dev_start) {
pr_debug("md/raid0:%s: checking %pg ... nope\n",
mdname(mddev),
rdev->bdev);
continue;
}
pr_debug("md/raid0:%s: checking %pg ..."
" contained as device %d\n",
mdname(mddev),
rdev->bdev, c);
dev[c] = rdev;
c++;
if (!smallest || rdev->sectors < smallest->sectors) {
smallest = rdev;
pr_debug("md/raid0:%s: (%llu) is smallest!.\n",
mdname(mddev),
(unsigned long long)rdev->sectors);
}
}
zone->nb_dev = c;
sectors = (smallest->sectors - zone->dev_start) * c;
pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n",
mdname(mddev),
zone->nb_dev, (unsigned long long)sectors);
curr_zone_end += sectors;
zone->zone_end = curr_zone_end;
pr_debug("md/raid0:%s: current zone start: %llu\n",
mdname(mddev),
(unsigned long long)smallest->sectors);
}
if (conf->nr_strip_zones == 1 || conf->strip_zone[1].nb_dev == 1) {
conf->layout = RAID0_ORIG_LAYOUT;
} else if (mddev->layout == RAID0_ORIG_LAYOUT ||
mddev->layout == RAID0_ALT_MULTIZONE_LAYOUT) {
conf->layout = mddev->layout;
} else if (default_layout == RAID0_ORIG_LAYOUT ||
default_layout == RAID0_ALT_MULTIZONE_LAYOUT) {
conf->layout = default_layout;
} else {
pr_err("md/raid0:%s: cannot assemble multi-zone RAID0 with default_layout setting\n",
mdname(mddev));
pr_err("md/raid0: please set raid0.default_layout to 1 or 2\n");
err = -EOPNOTSUPP;
goto abort;
}
if (conf->layout == RAID0_ORIG_LAYOUT) {
for (i = 1; i < conf->nr_strip_zones; i++) {
sector_t first_sector = conf->strip_zone[i-1].zone_end;
sector_div(first_sector, mddev->chunk_sectors);
zone = conf->strip_zone + i;
/* disk_shift is first disk index used in the zone */
zone->disk_shift = sector_div(first_sector,
zone->nb_dev);
}
}
pr_debug("md/raid0:%s: done.\n", mdname(mddev));
*private_conf = conf;
return 0;
abort:
kfree(conf->strip_zone);
kfree(conf->devlist);
kfree(conf);
*private_conf = ERR_PTR(err);
return err;
}
/* Find the zone which holds a particular offset
* Update *sectorp to be an offset in that zone
*/
static struct strip_zone *find_zone(struct r0conf *conf,
sector_t *sectorp)
{
int i;
struct strip_zone *z = conf->strip_zone;
sector_t sector = *sectorp;
for (i = 0; i < conf->nr_strip_zones; i++)
if (sector < z[i].zone_end) {
if (i)
*sectorp = sector - z[i-1].zone_end;
return z + i;
}
BUG();
}
/*
* remaps the bio to the target device. we separate two flows.
* power 2 flow and a general flow for the sake of performance
*/
static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone,
sector_t sector, sector_t *sector_offset)
{
unsigned int sect_in_chunk;
sector_t chunk;
struct r0conf *conf = mddev->private;
int raid_disks = conf->strip_zone[0].nb_dev;
unsigned int chunk_sects = mddev->chunk_sectors;
if (is_power_of_2(chunk_sects)) {
int chunksect_bits = ffz(~chunk_sects);
/* find the sector offset inside the chunk */
sect_in_chunk = sector & (chunk_sects - 1);
sector >>= chunksect_bits;
/* chunk in zone */
chunk = *sector_offset;
/* quotient is the chunk in real device*/
sector_div(chunk, zone->nb_dev << chunksect_bits);
} else{
sect_in_chunk = sector_div(sector, chunk_sects);
chunk = *sector_offset;
sector_div(chunk, chunk_sects * zone->nb_dev);
}
/*
* position the bio over the real device
* real sector = chunk in device + starting of zone
* + the position in the chunk
*/
*sector_offset = (chunk * chunk_sects) + sect_in_chunk;
return conf->devlist[(zone - conf->strip_zone)*raid_disks
+ sector_div(sector, zone->nb_dev)];
}
static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks)
{
sector_t array_sectors = 0;
struct md_rdev *rdev;
WARN_ONCE(sectors || raid_disks,
"%s does not support generic reshape\n", __func__);
rdev_for_each(rdev, mddev)
array_sectors += (rdev->sectors &
~(sector_t)(mddev->chunk_sectors-1));
return array_sectors;
}
static void free_conf(struct mddev *mddev, struct r0conf *conf)
{
kfree(conf->strip_zone);
kfree(conf->devlist);
kfree(conf);
}
static void raid0_free(struct mddev *mddev, void *priv)
{
struct r0conf *conf = priv;
free_conf(mddev, conf);
}
static int raid0_run(struct mddev *mddev)
{
struct r0conf *conf;
int ret;
if (mddev->chunk_sectors == 0) {
pr_warn("md/raid0:%s: chunk size must be set.\n", mdname(mddev));
return -EINVAL;
}
if (md_check_no_bitmap(mddev))
return -EINVAL;
/* if private is not null, we are here after takeover */
if (mddev->private == NULL) {
ret = create_strip_zones(mddev, &conf);
if (ret < 0)
return ret;
mddev->private = conf;
}
conf = mddev->private;
if (mddev->queue) {
struct md_rdev *rdev;
blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors);
blk_queue_max_write_zeroes_sectors(mddev->queue, mddev->chunk_sectors);
blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9);
blk_queue_io_opt(mddev->queue,
(mddev->chunk_sectors << 9) * mddev->raid_disks);
rdev_for_each(rdev, mddev) {
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
}
}
/* calculate array device size */
md_set_array_sectors(mddev, raid0_size(mddev, 0, 0));
pr_debug("md/raid0:%s: md_size is %llu sectors.\n",
mdname(mddev),
(unsigned long long)mddev->array_sectors);
dump_zones(mddev);
ret = md_integrity_register(mddev);
if (ret)
free_conf(mddev, conf);
return ret;
}
/*
* Convert disk_index to the disk order in which it is read/written.
* For example, if we have 4 disks, they are numbered 0,1,2,3. If we
* write the disks starting at disk 3, then the read/write order would
* be disk 3, then 0, then 1, and then disk 2 and we want map_disk_shift()
* to map the disks as follows 0,1,2,3 => 1,2,3,0. So disk 0 would map
* to 1, 1 to 2, 2 to 3, and 3 to 0. That way we can compare disks in
* that 'output' space to understand the read/write disk ordering.
*/
static int map_disk_shift(int disk_index, int num_disks, int disk_shift)
{
return ((disk_index + num_disks - disk_shift) % num_disks);
}
static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
{
struct r0conf *conf = mddev->private;
struct strip_zone *zone;
sector_t start = bio->bi_iter.bi_sector;
sector_t end;
unsigned int stripe_size;
sector_t first_stripe_index, last_stripe_index;
sector_t start_disk_offset;
unsigned int start_disk_index;
sector_t end_disk_offset;
unsigned int end_disk_index;
unsigned int disk;
sector_t orig_start, orig_end;
orig_start = start;
zone = find_zone(conf, &start);
if (bio_end_sector(bio) > zone->zone_end) {
struct bio *split = bio_split(bio,
zone->zone_end - bio->bi_iter.bi_sector, GFP_NOIO,
&mddev->bio_set);
bio_chain(split, bio);
submit_bio_noacct(bio);
bio = split;
end = zone->zone_end;
} else
end = bio_end_sector(bio);
orig_end = end;
if (zone != conf->strip_zone)
end = end - zone[-1].zone_end;
/* Now start and end is the offset in zone */
stripe_size = zone->nb_dev * mddev->chunk_sectors;
first_stripe_index = start;
sector_div(first_stripe_index, stripe_size);
last_stripe_index = end;
sector_div(last_stripe_index, stripe_size);
/* In the first zone the original and alternate layouts are the same */
if ((conf->layout == RAID0_ORIG_LAYOUT) && (zone != conf->strip_zone)) {
sector_div(orig_start, mddev->chunk_sectors);
start_disk_index = sector_div(orig_start, zone->nb_dev);
start_disk_index = map_disk_shift(start_disk_index,
zone->nb_dev,
zone->disk_shift);
sector_div(orig_end, mddev->chunk_sectors);
end_disk_index = sector_div(orig_end, zone->nb_dev);
end_disk_index = map_disk_shift(end_disk_index,
zone->nb_dev, zone->disk_shift);
} else {
start_disk_index = (int)(start - first_stripe_index * stripe_size) /
mddev->chunk_sectors;
end_disk_index = (int)(end - last_stripe_index * stripe_size) /
mddev->chunk_sectors;
}
start_disk_offset = ((int)(start - first_stripe_index * stripe_size) %
mddev->chunk_sectors) +
first_stripe_index * mddev->chunk_sectors;
end_disk_offset = ((int)(end - last_stripe_index * stripe_size) %
mddev->chunk_sectors) +
last_stripe_index * mddev->chunk_sectors;
for (disk = 0; disk < zone->nb_dev; disk++) {
sector_t dev_start, dev_end;
struct md_rdev *rdev;
int compare_disk;
compare_disk = map_disk_shift(disk, zone->nb_dev,
zone->disk_shift);
if (compare_disk < start_disk_index)
dev_start = (first_stripe_index + 1) *
mddev->chunk_sectors;
else if (compare_disk > start_disk_index)
dev_start = first_stripe_index * mddev->chunk_sectors;
else
dev_start = start_disk_offset;
if (compare_disk < end_disk_index)
dev_end = (last_stripe_index + 1) * mddev->chunk_sectors;
else if (compare_disk > end_disk_index)
dev_end = last_stripe_index * mddev->chunk_sectors;
else
dev_end = end_disk_offset;
if (dev_end <= dev_start)
continue;
rdev = conf->devlist[(zone - conf->strip_zone) *
conf->strip_zone[0].nb_dev + disk];
md_submit_discard_bio(mddev, rdev, bio,
dev_start + zone->dev_start + rdev->data_offset,
dev_end - dev_start);
}
bio_endio(bio);
}
static void raid0_map_submit_bio(struct mddev *mddev, struct bio *bio)
{
struct r0conf *conf = mddev->private;
struct strip_zone *zone;
struct md_rdev *tmp_dev;
sector_t bio_sector = bio->bi_iter.bi_sector;
sector_t sector = bio_sector;
md_account_bio(mddev, &bio);
zone = find_zone(mddev->private, §or);
switch (conf->layout) {
case RAID0_ORIG_LAYOUT:
tmp_dev = map_sector(mddev, zone, bio_sector, §or);
break;
case RAID0_ALT_MULTIZONE_LAYOUT:
tmp_dev = map_sector(mddev, zone, sector, §or);
break;
default:
WARN(1, "md/raid0:%s: Invalid layout\n", mdname(mddev));
bio_io_error(bio);
return;
}
if (unlikely(is_rdev_broken(tmp_dev))) {
bio_io_error(bio);
md_error(mddev, tmp_dev);
return;
}
bio_set_dev(bio, tmp_dev->bdev);
bio->bi_iter.bi_sector = sector + zone->dev_start +
tmp_dev->data_offset;
if (mddev->gendisk)
trace_block_bio_remap(bio, disk_devt(mddev->gendisk),
bio_sector);
mddev_check_write_zeroes(mddev, bio);
submit_bio_noacct(bio);
}
static bool raid0_make_request(struct mddev *mddev, struct bio *bio)
{
sector_t sector;
unsigned chunk_sects;
unsigned sectors;
if (unlikely(bio->bi_opf & REQ_PREFLUSH)
&& md_flush_request(mddev, bio))
return true;
if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) {
raid0_handle_discard(mddev, bio);
return true;
}
sector = bio->bi_iter.bi_sector;
chunk_sects = mddev->chunk_sectors;
sectors = chunk_sects -
(likely(is_power_of_2(chunk_sects))
? (sector & (chunk_sects-1))
: sector_div(sector, chunk_sects));
if (sectors < bio_sectors(bio)) {
struct bio *split = bio_split(bio, sectors, GFP_NOIO,
&mddev->bio_set);
bio_chain(split, bio);
raid0_map_submit_bio(mddev, bio);
bio = split;
}
raid0_map_submit_bio(mddev, bio);
return true;
}
static void raid0_status(struct seq_file *seq, struct mddev *mddev)
{
seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2);
return;
}
static void raid0_error(struct mddev *mddev, struct md_rdev *rdev)
{
if (!test_and_set_bit(MD_BROKEN, &mddev->flags)) {
char *md_name = mdname(mddev);
pr_crit("md/raid0%s: Disk failure on %pg detected, failing array.\n",
md_name, rdev->bdev);
}
}
static void *raid0_takeover_raid45(struct mddev *mddev)
{
struct md_rdev *rdev;
struct r0conf *priv_conf;
if (mddev->degraded != 1) {
pr_warn("md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n",
mdname(mddev),
mddev->degraded);
return ERR_PTR(-EINVAL);
}
rdev_for_each(rdev, mddev) {
/* check slot number for a disk */
if (rdev->raid_disk == mddev->raid_disks-1) {
pr_warn("md/raid0:%s: raid5 must have missing parity disk!\n",
mdname(mddev));
return ERR_PTR(-EINVAL);
}
rdev->sectors = mddev->dev_sectors;
}
/* Set new parameters */
mddev->new_level = 0;
mddev->new_layout = 0;
mddev->new_chunk_sectors = mddev->chunk_sectors;
mddev->raid_disks--;
mddev->delta_disks = -1;
/* make sure it will be not marked as dirty */
mddev->recovery_cp = MaxSector;
mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
create_strip_zones(mddev, &priv_conf);
return priv_conf;
}
static void *raid0_takeover_raid10(struct mddev *mddev)
{
struct r0conf *priv_conf;
/* Check layout:
* - far_copies must be 1
* - near_copies must be 2
* - disks number must be even
* - all mirrors must be already degraded
*/
if (mddev->layout != ((1 << 8) + 2)) {
pr_warn("md/raid0:%s:: Raid0 cannot takeover layout: 0x%x\n",
mdname(mddev),
mddev->layout);
return ERR_PTR(-EINVAL);
}
if (mddev->raid_disks & 1) {
pr_warn("md/raid0:%s: Raid0 cannot takeover Raid10 with odd disk number.\n",
mdname(mddev));
return ERR_PTR(-EINVAL);
}
if (mddev->degraded != (mddev->raid_disks>>1)) {
pr_warn("md/raid0:%s: All mirrors must be already degraded!\n",
mdname(mddev));
return ERR_PTR(-EINVAL);
}
/* Set new parameters */
mddev->new_level = 0;
mddev->new_layout = 0;
mddev->new_chunk_sectors = mddev->chunk_sectors;
mddev->delta_disks = - mddev->raid_disks / 2;
mddev->raid_disks += mddev->delta_disks;
mddev->degraded = 0;
/* make sure it will be not marked as dirty */
mddev->recovery_cp = MaxSector;
mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
create_strip_zones(mddev, &priv_conf);
return priv_conf;
}
static void *raid0_takeover_raid1(struct mddev *mddev)
{
struct r0conf *priv_conf;
int chunksect;
/* Check layout:
* - (N - 1) mirror drives must be already faulty
*/
if ((mddev->raid_disks - 1) != mddev->degraded) {
pr_err("md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n",
mdname(mddev));
return ERR_PTR(-EINVAL);
}
/*
* a raid1 doesn't have the notion of chunk size, so
* figure out the largest suitable size we can use.
*/
chunksect = 64 * 2; /* 64K by default */
/* The array must be an exact multiple of chunksize */
while (chunksect && (mddev->array_sectors & (chunksect - 1)))
chunksect >>= 1;
if ((chunksect << 9) < PAGE_SIZE)
/* array size does not allow a suitable chunk size */
return ERR_PTR(-EINVAL);
/* Set new parameters */
mddev->new_level = 0;
mddev->new_layout = 0;
mddev->new_chunk_sectors = chunksect;
mddev->chunk_sectors = chunksect;
mddev->delta_disks = 1 - mddev->raid_disks;
mddev->raid_disks = 1;
/* make sure it will be not marked as dirty */
mddev->recovery_cp = MaxSector;
mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
create_strip_zones(mddev, &priv_conf);
return priv_conf;
}
static void *raid0_takeover(struct mddev *mddev)
{
/* raid0 can take over:
* raid4 - if all data disks are active.
* raid5 - providing it is Raid4 layout and one disk is faulty
* raid10 - assuming we have all necessary active disks
* raid1 - with (N -1) mirror drives faulty
*/
if (mddev->bitmap) {
pr_warn("md/raid0: %s: cannot takeover array with bitmap\n",
mdname(mddev));
return ERR_PTR(-EBUSY);
}
if (mddev->level == 4)
return raid0_takeover_raid45(mddev);
if (mddev->level == 5) {
if (mddev->layout == ALGORITHM_PARITY_N)
return raid0_takeover_raid45(mddev);
pr_warn("md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n",
mdname(mddev), ALGORITHM_PARITY_N);
}
if (mddev->level == 10)
return raid0_takeover_raid10(mddev);
if (mddev->level == 1)
return raid0_takeover_raid1(mddev);
pr_warn("Takeover from raid%i to raid0 not supported\n",
mddev->level);
return ERR_PTR(-EINVAL);
}
static void raid0_quiesce(struct mddev *mddev, int quiesce)
{
}
static struct md_personality raid0_personality=
{
.name = "raid0",
.level = 0,
.owner = THIS_MODULE,
.make_request = raid0_make_request,
.run = raid0_run,
.free = raid0_free,
.status = raid0_status,
.size = raid0_size,
.takeover = raid0_takeover,
.quiesce = raid0_quiesce,
.error_handler = raid0_error,
};
static int __init raid0_init (void)
{
return register_md_personality (&raid0_personality);
}
static void raid0_exit (void)
{
unregister_md_personality (&raid0_personality);
}
module_init(raid0_init);
module_exit(raid0_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("RAID0 (striping) personality for MD");
MODULE_ALIAS("md-personality-2"); /* RAID0 */
MODULE_ALIAS("md-raid0");
MODULE_ALIAS("md-level-0");
| linux-master | drivers/md/raid0.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2001-2002 Sistina Software (UK) Limited.
* Copyright (C) 2006-2008 Red Hat GmbH
*
* This file is released under the GPL.
*/
#include "dm-exception-store.h"
#include <linux/ctype.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/vmalloc.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/dm-io.h>
#include <linux/dm-bufio.h>
#define DM_MSG_PREFIX "persistent snapshot"
#define DM_CHUNK_SIZE_DEFAULT_SECTORS 32U /* 16KB */
#define DM_PREFETCH_CHUNKS 12
/*
*---------------------------------------------------------------
* Persistent snapshots, by persistent we mean that the snapshot
* will survive a reboot.
*---------------------------------------------------------------
*/
/*
* We need to store a record of which parts of the origin have
* been copied to the snapshot device. The snapshot code
* requires that we copy exception chunks to chunk aligned areas
* of the COW store. It makes sense therefore, to store the
* metadata in chunk size blocks.
*
* There is no backward or forward compatibility implemented,
* snapshots with different disk versions than the kernel will
* not be usable. It is expected that "lvcreate" will blank out
* the start of a fresh COW device before calling the snapshot
* constructor.
*
* The first chunk of the COW device just contains the header.
* After this there is a chunk filled with exception metadata,
* followed by as many exception chunks as can fit in the
* metadata areas.
*
* All on disk structures are in little-endian format. The end
* of the exceptions info is indicated by an exception with a
* new_chunk of 0, which is invalid since it would point to the
* header chunk.
*/
/*
* Magic for persistent snapshots: "SnAp" - Feeble isn't it.
*/
#define SNAP_MAGIC 0x70416e53
/*
* The on-disk version of the metadata.
*/
#define SNAPSHOT_DISK_VERSION 1
#define NUM_SNAPSHOT_HDR_CHUNKS 1
struct disk_header {
__le32 magic;
/*
* Is this snapshot valid. There is no way of recovering
* an invalid snapshot.
*/
__le32 valid;
/*
* Simple, incrementing version. no backward
* compatibility.
*/
__le32 version;
/* In sectors */
__le32 chunk_size;
} __packed;
struct disk_exception {
__le64 old_chunk;
__le64 new_chunk;
} __packed;
struct core_exception {
uint64_t old_chunk;
uint64_t new_chunk;
};
struct commit_callback {
void (*callback)(void *ref, int success);
void *context;
};
/*
* The top level structure for a persistent exception store.
*/
struct pstore {
struct dm_exception_store *store;
int version;
int valid;
uint32_t exceptions_per_area;
/*
* Now that we have an asynchronous kcopyd there is no
* need for large chunk sizes, so it wont hurt to have a
* whole chunks worth of metadata in memory at once.
*/
void *area;
/*
* An area of zeros used to clear the next area.
*/
void *zero_area;
/*
* An area used for header. The header can be written
* concurrently with metadata (when invalidating the snapshot),
* so it needs a separate buffer.
*/
void *header_area;
/*
* Used to keep track of which metadata area the data in
* 'chunk' refers to.
*/
chunk_t current_area;
/*
* The next free chunk for an exception.
*
* When creating exceptions, all the chunks here and above are
* free. It holds the next chunk to be allocated. On rare
* occasions (e.g. after a system crash) holes can be left in
* the exception store because chunks can be committed out of
* order.
*
* When merging exceptions, it does not necessarily mean all the
* chunks here and above are free. It holds the value it would
* have held if all chunks had been committed in order of
* allocation. Consequently the value may occasionally be
* slightly too low, but since it's only used for 'status' and
* it can never reach its minimum value too early this doesn't
* matter.
*/
chunk_t next_free;
/*
* The index of next free exception in the current
* metadata area.
*/
uint32_t current_committed;
atomic_t pending_count;
uint32_t callback_count;
struct commit_callback *callbacks;
struct dm_io_client *io_client;
struct workqueue_struct *metadata_wq;
};
static int alloc_area(struct pstore *ps)
{
int r = -ENOMEM;
size_t len;
len = ps->store->chunk_size << SECTOR_SHIFT;
/*
* Allocate the chunk_size block of memory that will hold
* a single metadata area.
*/
ps->area = vmalloc(len);
if (!ps->area)
goto err_area;
ps->zero_area = vzalloc(len);
if (!ps->zero_area)
goto err_zero_area;
ps->header_area = vmalloc(len);
if (!ps->header_area)
goto err_header_area;
return 0;
err_header_area:
vfree(ps->zero_area);
err_zero_area:
vfree(ps->area);
err_area:
return r;
}
static void free_area(struct pstore *ps)
{
vfree(ps->area);
ps->area = NULL;
vfree(ps->zero_area);
ps->zero_area = NULL;
vfree(ps->header_area);
ps->header_area = NULL;
}
struct mdata_req {
struct dm_io_region *where;
struct dm_io_request *io_req;
struct work_struct work;
int result;
};
static void do_metadata(struct work_struct *work)
{
struct mdata_req *req = container_of(work, struct mdata_req, work);
req->result = dm_io(req->io_req, 1, req->where, NULL);
}
/*
* Read or write a chunk aligned and sized block of data from a device.
*/
static int chunk_io(struct pstore *ps, void *area, chunk_t chunk, blk_opf_t opf,
int metadata)
{
struct dm_io_region where = {
.bdev = dm_snap_cow(ps->store->snap)->bdev,
.sector = ps->store->chunk_size * chunk,
.count = ps->store->chunk_size,
};
struct dm_io_request io_req = {
.bi_opf = opf,
.mem.type = DM_IO_VMA,
.mem.ptr.vma = area,
.client = ps->io_client,
.notify.fn = NULL,
};
struct mdata_req req;
if (!metadata)
return dm_io(&io_req, 1, &where, NULL);
req.where = &where;
req.io_req = &io_req;
/*
* Issue the synchronous I/O from a different thread
* to avoid submit_bio_noacct recursion.
*/
INIT_WORK_ONSTACK(&req.work, do_metadata);
queue_work(ps->metadata_wq, &req.work);
flush_workqueue(ps->metadata_wq);
destroy_work_on_stack(&req.work);
return req.result;
}
/*
* Convert a metadata area index to a chunk index.
*/
static chunk_t area_location(struct pstore *ps, chunk_t area)
{
return NUM_SNAPSHOT_HDR_CHUNKS + ((ps->exceptions_per_area + 1) * area);
}
static void skip_metadata(struct pstore *ps)
{
uint32_t stride = ps->exceptions_per_area + 1;
chunk_t next_free = ps->next_free;
if (sector_div(next_free, stride) == NUM_SNAPSHOT_HDR_CHUNKS)
ps->next_free++;
}
/*
* Read or write a metadata area. Remembering to skip the first
* chunk which holds the header.
*/
static int area_io(struct pstore *ps, blk_opf_t opf)
{
chunk_t chunk = area_location(ps, ps->current_area);
return chunk_io(ps, ps->area, chunk, opf, 0);
}
static void zero_memory_area(struct pstore *ps)
{
memset(ps->area, 0, ps->store->chunk_size << SECTOR_SHIFT);
}
static int zero_disk_area(struct pstore *ps, chunk_t area)
{
return chunk_io(ps, ps->zero_area, area_location(ps, area),
REQ_OP_WRITE, 0);
}
static int read_header(struct pstore *ps, int *new_snapshot)
{
int r;
struct disk_header *dh;
unsigned int chunk_size;
int chunk_size_supplied = 1;
char *chunk_err;
/*
* Use default chunk size (or logical_block_size, if larger)
* if none supplied
*/
if (!ps->store->chunk_size) {
ps->store->chunk_size = max(DM_CHUNK_SIZE_DEFAULT_SECTORS,
bdev_logical_block_size(dm_snap_cow(ps->store->snap)->
bdev) >> 9);
ps->store->chunk_mask = ps->store->chunk_size - 1;
ps->store->chunk_shift = __ffs(ps->store->chunk_size);
chunk_size_supplied = 0;
}
ps->io_client = dm_io_client_create();
if (IS_ERR(ps->io_client))
return PTR_ERR(ps->io_client);
r = alloc_area(ps);
if (r)
return r;
r = chunk_io(ps, ps->header_area, 0, REQ_OP_READ, 1);
if (r)
goto bad;
dh = ps->header_area;
if (le32_to_cpu(dh->magic) == 0) {
*new_snapshot = 1;
return 0;
}
if (le32_to_cpu(dh->magic) != SNAP_MAGIC) {
DMWARN("Invalid or corrupt snapshot");
r = -ENXIO;
goto bad;
}
*new_snapshot = 0;
ps->valid = le32_to_cpu(dh->valid);
ps->version = le32_to_cpu(dh->version);
chunk_size = le32_to_cpu(dh->chunk_size);
if (ps->store->chunk_size == chunk_size)
return 0;
if (chunk_size_supplied)
DMWARN("chunk size %u in device metadata overrides table chunk size of %u.",
chunk_size, ps->store->chunk_size);
/* We had a bogus chunk_size. Fix stuff up. */
free_area(ps);
r = dm_exception_store_set_chunk_size(ps->store, chunk_size,
&chunk_err);
if (r) {
DMERR("invalid on-disk chunk size %u: %s.",
chunk_size, chunk_err);
return r;
}
r = alloc_area(ps);
return r;
bad:
free_area(ps);
return r;
}
static int write_header(struct pstore *ps)
{
struct disk_header *dh;
memset(ps->header_area, 0, ps->store->chunk_size << SECTOR_SHIFT);
dh = ps->header_area;
dh->magic = cpu_to_le32(SNAP_MAGIC);
dh->valid = cpu_to_le32(ps->valid);
dh->version = cpu_to_le32(ps->version);
dh->chunk_size = cpu_to_le32(ps->store->chunk_size);
return chunk_io(ps, ps->header_area, 0, REQ_OP_WRITE, 1);
}
/*
* Access functions for the disk exceptions, these do the endian conversions.
*/
static struct disk_exception *get_exception(struct pstore *ps, void *ps_area,
uint32_t index)
{
BUG_ON(index >= ps->exceptions_per_area);
return ((struct disk_exception *) ps_area) + index;
}
static void read_exception(struct pstore *ps, void *ps_area,
uint32_t index, struct core_exception *result)
{
struct disk_exception *de = get_exception(ps, ps_area, index);
/* copy it */
result->old_chunk = le64_to_cpu(de->old_chunk);
result->new_chunk = le64_to_cpu(de->new_chunk);
}
static void write_exception(struct pstore *ps,
uint32_t index, struct core_exception *e)
{
struct disk_exception *de = get_exception(ps, ps->area, index);
/* copy it */
de->old_chunk = cpu_to_le64(e->old_chunk);
de->new_chunk = cpu_to_le64(e->new_chunk);
}
static void clear_exception(struct pstore *ps, uint32_t index)
{
struct disk_exception *de = get_exception(ps, ps->area, index);
/* clear it */
de->old_chunk = 0;
de->new_chunk = 0;
}
/*
* Registers the exceptions that are present in the current area.
* 'full' is filled in to indicate if the area has been
* filled.
*/
static int insert_exceptions(struct pstore *ps, void *ps_area,
int (*callback)(void *callback_context,
chunk_t old, chunk_t new),
void *callback_context,
int *full)
{
int r;
unsigned int i;
struct core_exception e;
/* presume the area is full */
*full = 1;
for (i = 0; i < ps->exceptions_per_area; i++) {
read_exception(ps, ps_area, i, &e);
/*
* If the new_chunk is pointing at the start of
* the COW device, where the first metadata area
* is we know that we've hit the end of the
* exceptions. Therefore the area is not full.
*/
if (e.new_chunk == 0LL) {
ps->current_committed = i;
*full = 0;
break;
}
/*
* Keep track of the start of the free chunks.
*/
if (ps->next_free <= e.new_chunk)
ps->next_free = e.new_chunk + 1;
/*
* Otherwise we add the exception to the snapshot.
*/
r = callback(callback_context, e.old_chunk, e.new_chunk);
if (r)
return r;
}
return 0;
}
static int read_exceptions(struct pstore *ps,
int (*callback)(void *callback_context, chunk_t old,
chunk_t new),
void *callback_context)
{
int r, full = 1;
struct dm_bufio_client *client;
chunk_t prefetch_area = 0;
client = dm_bufio_client_create(dm_snap_cow(ps->store->snap)->bdev,
ps->store->chunk_size << SECTOR_SHIFT,
1, 0, NULL, NULL, 0);
if (IS_ERR(client))
return PTR_ERR(client);
/*
* Setup for one current buffer + desired readahead buffers.
*/
dm_bufio_set_minimum_buffers(client, 1 + DM_PREFETCH_CHUNKS);
/*
* Keeping reading chunks and inserting exceptions until
* we find a partially full area.
*/
for (ps->current_area = 0; full; ps->current_area++) {
struct dm_buffer *bp;
void *area;
chunk_t chunk;
if (unlikely(prefetch_area < ps->current_area))
prefetch_area = ps->current_area;
if (DM_PREFETCH_CHUNKS) {
do {
chunk_t pf_chunk = area_location(ps, prefetch_area);
if (unlikely(pf_chunk >= dm_bufio_get_device_size(client)))
break;
dm_bufio_prefetch(client, pf_chunk, 1);
prefetch_area++;
if (unlikely(!prefetch_area))
break;
} while (prefetch_area <= ps->current_area + DM_PREFETCH_CHUNKS);
}
chunk = area_location(ps, ps->current_area);
area = dm_bufio_read(client, chunk, &bp);
if (IS_ERR(area)) {
r = PTR_ERR(area);
goto ret_destroy_bufio;
}
r = insert_exceptions(ps, area, callback, callback_context,
&full);
if (!full)
memcpy(ps->area, area, ps->store->chunk_size << SECTOR_SHIFT);
dm_bufio_release(bp);
dm_bufio_forget(client, chunk);
if (unlikely(r))
goto ret_destroy_bufio;
}
ps->current_area--;
skip_metadata(ps);
r = 0;
ret_destroy_bufio:
dm_bufio_client_destroy(client);
return r;
}
static struct pstore *get_info(struct dm_exception_store *store)
{
return store->context;
}
static void persistent_usage(struct dm_exception_store *store,
sector_t *total_sectors,
sector_t *sectors_allocated,
sector_t *metadata_sectors)
{
struct pstore *ps = get_info(store);
*sectors_allocated = ps->next_free * store->chunk_size;
*total_sectors = get_dev_size(dm_snap_cow(store->snap)->bdev);
/*
* First chunk is the fixed header.
* Then there are (ps->current_area + 1) metadata chunks, each one
* separated from the next by ps->exceptions_per_area data chunks.
*/
*metadata_sectors = (ps->current_area + 1 + NUM_SNAPSHOT_HDR_CHUNKS) *
store->chunk_size;
}
static void persistent_dtr(struct dm_exception_store *store)
{
struct pstore *ps = get_info(store);
destroy_workqueue(ps->metadata_wq);
/* Created in read_header */
if (ps->io_client)
dm_io_client_destroy(ps->io_client);
free_area(ps);
/* Allocated in persistent_read_metadata */
kvfree(ps->callbacks);
kfree(ps);
}
static int persistent_read_metadata(struct dm_exception_store *store,
int (*callback)(void *callback_context,
chunk_t old, chunk_t new),
void *callback_context)
{
int r, new_snapshot;
struct pstore *ps = get_info(store);
/*
* Read the snapshot header.
*/
r = read_header(ps, &new_snapshot);
if (r)
return r;
/*
* Now we know correct chunk_size, complete the initialisation.
*/
ps->exceptions_per_area = (ps->store->chunk_size << SECTOR_SHIFT) /
sizeof(struct disk_exception);
ps->callbacks = kvcalloc(ps->exceptions_per_area,
sizeof(*ps->callbacks), GFP_KERNEL);
if (!ps->callbacks)
return -ENOMEM;
/*
* Do we need to setup a new snapshot ?
*/
if (new_snapshot) {
r = write_header(ps);
if (r) {
DMWARN("write_header failed");
return r;
}
ps->current_area = 0;
zero_memory_area(ps);
r = zero_disk_area(ps, 0);
if (r)
DMWARN("zero_disk_area(0) failed");
return r;
}
/*
* Sanity checks.
*/
if (ps->version != SNAPSHOT_DISK_VERSION) {
DMWARN("unable to handle snapshot disk version %d",
ps->version);
return -EINVAL;
}
/*
* Metadata are valid, but snapshot is invalidated
*/
if (!ps->valid)
return 1;
/*
* Read the metadata.
*/
r = read_exceptions(ps, callback, callback_context);
return r;
}
static int persistent_prepare_exception(struct dm_exception_store *store,
struct dm_exception *e)
{
struct pstore *ps = get_info(store);
sector_t size = get_dev_size(dm_snap_cow(store->snap)->bdev);
/* Is there enough room ? */
if (size < ((ps->next_free + 1) * store->chunk_size))
return -ENOSPC;
e->new_chunk = ps->next_free;
/*
* Move onto the next free pending, making sure to take
* into account the location of the metadata chunks.
*/
ps->next_free++;
skip_metadata(ps);
atomic_inc(&ps->pending_count);
return 0;
}
static void persistent_commit_exception(struct dm_exception_store *store,
struct dm_exception *e, int valid,
void (*callback)(void *, int success),
void *callback_context)
{
unsigned int i;
struct pstore *ps = get_info(store);
struct core_exception ce;
struct commit_callback *cb;
if (!valid)
ps->valid = 0;
ce.old_chunk = e->old_chunk;
ce.new_chunk = e->new_chunk;
write_exception(ps, ps->current_committed++, &ce);
/*
* Add the callback to the back of the array. This code
* is the only place where the callback array is
* manipulated, and we know that it will never be called
* multiple times concurrently.
*/
cb = ps->callbacks + ps->callback_count++;
cb->callback = callback;
cb->context = callback_context;
/*
* If there are exceptions in flight and we have not yet
* filled this metadata area there's nothing more to do.
*/
if (!atomic_dec_and_test(&ps->pending_count) &&
(ps->current_committed != ps->exceptions_per_area))
return;
/*
* If we completely filled the current area, then wipe the next one.
*/
if ((ps->current_committed == ps->exceptions_per_area) &&
zero_disk_area(ps, ps->current_area + 1))
ps->valid = 0;
/*
* Commit exceptions to disk.
*/
if (ps->valid && area_io(ps, REQ_OP_WRITE | REQ_PREFLUSH | REQ_FUA |
REQ_SYNC))
ps->valid = 0;
/*
* Advance to the next area if this one is full.
*/
if (ps->current_committed == ps->exceptions_per_area) {
ps->current_committed = 0;
ps->current_area++;
zero_memory_area(ps);
}
for (i = 0; i < ps->callback_count; i++) {
cb = ps->callbacks + i;
cb->callback(cb->context, ps->valid);
}
ps->callback_count = 0;
}
static int persistent_prepare_merge(struct dm_exception_store *store,
chunk_t *last_old_chunk,
chunk_t *last_new_chunk)
{
struct pstore *ps = get_info(store);
struct core_exception ce;
int nr_consecutive;
int r;
/*
* When current area is empty, move back to preceding area.
*/
if (!ps->current_committed) {
/*
* Have we finished?
*/
if (!ps->current_area)
return 0;
ps->current_area--;
r = area_io(ps, REQ_OP_READ);
if (r < 0)
return r;
ps->current_committed = ps->exceptions_per_area;
}
read_exception(ps, ps->area, ps->current_committed - 1, &ce);
*last_old_chunk = ce.old_chunk;
*last_new_chunk = ce.new_chunk;
/*
* Find number of consecutive chunks within the current area,
* working backwards.
*/
for (nr_consecutive = 1; nr_consecutive < ps->current_committed;
nr_consecutive++) {
read_exception(ps, ps->area,
ps->current_committed - 1 - nr_consecutive, &ce);
if (ce.old_chunk != *last_old_chunk - nr_consecutive ||
ce.new_chunk != *last_new_chunk - nr_consecutive)
break;
}
return nr_consecutive;
}
static int persistent_commit_merge(struct dm_exception_store *store,
int nr_merged)
{
int r, i;
struct pstore *ps = get_info(store);
BUG_ON(nr_merged > ps->current_committed);
for (i = 0; i < nr_merged; i++)
clear_exception(ps, ps->current_committed - 1 - i);
r = area_io(ps, REQ_OP_WRITE | REQ_PREFLUSH | REQ_FUA);
if (r < 0)
return r;
ps->current_committed -= nr_merged;
/*
* At this stage, only persistent_usage() uses ps->next_free, so
* we make no attempt to keep ps->next_free strictly accurate
* as exceptions may have been committed out-of-order originally.
* Once a snapshot has become merging, we set it to the value it
* would have held had all the exceptions been committed in order.
*
* ps->current_area does not get reduced by prepare_merge() until
* after commit_merge() has removed the nr_merged previous exceptions.
*/
ps->next_free = area_location(ps, ps->current_area) +
ps->current_committed + 1;
return 0;
}
static void persistent_drop_snapshot(struct dm_exception_store *store)
{
struct pstore *ps = get_info(store);
ps->valid = 0;
if (write_header(ps))
DMWARN("write header failed");
}
static int persistent_ctr(struct dm_exception_store *store, char *options)
{
struct pstore *ps;
int r;
/* allocate the pstore */
ps = kzalloc(sizeof(*ps), GFP_KERNEL);
if (!ps)
return -ENOMEM;
ps->store = store;
ps->valid = 1;
ps->version = SNAPSHOT_DISK_VERSION;
ps->area = NULL;
ps->zero_area = NULL;
ps->header_area = NULL;
ps->next_free = NUM_SNAPSHOT_HDR_CHUNKS + 1; /* header and 1st area */
ps->current_committed = 0;
ps->callback_count = 0;
atomic_set(&ps->pending_count, 0);
ps->callbacks = NULL;
ps->metadata_wq = alloc_workqueue("ksnaphd", WQ_MEM_RECLAIM, 0);
if (!ps->metadata_wq) {
DMERR("couldn't start header metadata update thread");
r = -ENOMEM;
goto err_workqueue;
}
if (options) {
char overflow = toupper(options[0]);
if (overflow == 'O')
store->userspace_supports_overflow = true;
else {
DMERR("Unsupported persistent store option: %s", options);
r = -EINVAL;
goto err_options;
}
}
store->context = ps;
return 0;
err_options:
destroy_workqueue(ps->metadata_wq);
err_workqueue:
kfree(ps);
return r;
}
static unsigned int persistent_status(struct dm_exception_store *store,
status_type_t status, char *result,
unsigned int maxlen)
{
unsigned int sz = 0;
switch (status) {
case STATUSTYPE_INFO:
break;
case STATUSTYPE_TABLE:
DMEMIT(" %s %llu", store->userspace_supports_overflow ? "PO" : "P",
(unsigned long long)store->chunk_size);
break;
case STATUSTYPE_IMA:
*result = '\0';
break;
}
return sz;
}
static struct dm_exception_store_type _persistent_type = {
.name = "persistent",
.module = THIS_MODULE,
.ctr = persistent_ctr,
.dtr = persistent_dtr,
.read_metadata = persistent_read_metadata,
.prepare_exception = persistent_prepare_exception,
.commit_exception = persistent_commit_exception,
.prepare_merge = persistent_prepare_merge,
.commit_merge = persistent_commit_merge,
.drop_snapshot = persistent_drop_snapshot,
.usage = persistent_usage,
.status = persistent_status,
};
static struct dm_exception_store_type _persistent_compat_type = {
.name = "P",
.module = THIS_MODULE,
.ctr = persistent_ctr,
.dtr = persistent_dtr,
.read_metadata = persistent_read_metadata,
.prepare_exception = persistent_prepare_exception,
.commit_exception = persistent_commit_exception,
.prepare_merge = persistent_prepare_merge,
.commit_merge = persistent_commit_merge,
.drop_snapshot = persistent_drop_snapshot,
.usage = persistent_usage,
.status = persistent_status,
};
int dm_persistent_snapshot_init(void)
{
int r;
r = dm_exception_store_type_register(&_persistent_type);
if (r) {
DMERR("Unable to register persistent exception store type");
return r;
}
r = dm_exception_store_type_register(&_persistent_compat_type);
if (r) {
DMERR("Unable to register old-style persistent exception store type");
dm_exception_store_type_unregister(&_persistent_type);
return r;
}
return r;
}
void dm_persistent_snapshot_exit(void)
{
dm_exception_store_type_unregister(&_persistent_type);
dm_exception_store_type_unregister(&_persistent_compat_type);
}
| linux-master | drivers/md/dm-snap-persistent.c |
// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/blkdev.h>
#include <linux/init.h>
#include <linux/mount.h>
#include <linux/major.h>
#include <linux/delay.h>
#include <linux/init_syscalls.h>
#include <linux/raid/detect.h>
#include <linux/raid/md_u.h>
#include <linux/raid/md_p.h>
#include "md.h"
/*
* When md (and any require personalities) are compiled into the kernel
* (not a module), arrays can be assembles are boot time using with AUTODETECT
* where specially marked partitions are registered with md_autodetect_dev(),
* and with MD_BOOT where devices to be collected are given on the boot line
* with md=.....
* The code for that is here.
*/
#ifdef CONFIG_MD_AUTODETECT
static int __initdata raid_noautodetect;
#else
static int __initdata raid_noautodetect=1;
#endif
static int __initdata raid_autopart;
static struct md_setup_args {
int minor;
int partitioned;
int level;
int chunk;
char *device_names;
} md_setup_args[256] __initdata;
static int md_setup_ents __initdata;
/*
* Parse the command-line parameters given our kernel, but do not
* actually try to invoke the MD device now; that is handled by
* md_setup_drive after the low-level disk drivers have initialised.
*
* 27/11/1999: Fixed to work correctly with the 2.3 kernel (which
* assigns the task of parsing integer arguments to the
* invoked program now). Added ability to initialise all
* the MD devices (by specifying multiple "md=" lines)
* instead of just one. -- KTK
* 18May2000: Added support for persistent-superblock arrays:
* md=n,0,factor,fault,device-list uses RAID0 for device n
* md=n,-1,factor,fault,device-list uses LINEAR for device n
* md=n,device-list reads a RAID superblock from the devices
* elements in device-list are read by name_to_kdev_t so can be
* a hex number or something like /dev/hda1 /dev/sdb
* 2001-06-03: Dave Cinege <[email protected]>
* Shifted name_to_kdev_t() and related operations to md_set_drive()
* for later execution. Rewrote section to make devfs compatible.
*/
static int __init md_setup(char *str)
{
int minor, level, factor, fault, partitioned = 0;
char *pername = "";
char *str1;
int ent;
if (*str == 'd') {
partitioned = 1;
str++;
}
if (get_option(&str, &minor) != 2) { /* MD Number */
printk(KERN_WARNING "md: Too few arguments supplied to md=.\n");
return 0;
}
str1 = str;
for (ent=0 ; ent< md_setup_ents ; ent++)
if (md_setup_args[ent].minor == minor &&
md_setup_args[ent].partitioned == partitioned) {
printk(KERN_WARNING "md: md=%s%d, Specified more than once. "
"Replacing previous definition.\n", partitioned?"d":"", minor);
break;
}
if (ent >= ARRAY_SIZE(md_setup_args)) {
printk(KERN_WARNING "md: md=%s%d - too many md initialisations\n", partitioned?"d":"", minor);
return 0;
}
if (ent >= md_setup_ents)
md_setup_ents++;
switch (get_option(&str, &level)) { /* RAID level */
case 2: /* could be 0 or -1.. */
if (level == 0 || level == LEVEL_LINEAR) {
if (get_option(&str, &factor) != 2 || /* Chunk Size */
get_option(&str, &fault) != 2) {
printk(KERN_WARNING "md: Too few arguments supplied to md=.\n");
return 0;
}
md_setup_args[ent].level = level;
md_setup_args[ent].chunk = 1 << (factor+12);
if (level == LEVEL_LINEAR)
pername = "linear";
else
pername = "raid0";
break;
}
fallthrough;
case 1: /* the first device is numeric */
str = str1;
fallthrough;
case 0:
md_setup_args[ent].level = LEVEL_NONE;
pername="super-block";
}
printk(KERN_INFO "md: Will configure md%d (%s) from %s, below.\n",
minor, pername, str);
md_setup_args[ent].device_names = str;
md_setup_args[ent].partitioned = partitioned;
md_setup_args[ent].minor = minor;
return 1;
}
static void __init md_setup_drive(struct md_setup_args *args)
{
char *devname = args->device_names;
dev_t devices[MD_SB_DISKS + 1], mdev;
struct mdu_array_info_s ainfo = { };
struct mddev *mddev;
int err = 0, i;
char name[16];
if (args->partitioned) {
mdev = MKDEV(mdp_major, args->minor << MdpMinorShift);
sprintf(name, "md_d%d", args->minor);
} else {
mdev = MKDEV(MD_MAJOR, args->minor);
sprintf(name, "md%d", args->minor);
}
for (i = 0; i < MD_SB_DISKS && devname != NULL; i++) {
struct kstat stat;
char *p;
char comp_name[64];
dev_t dev;
p = strchr(devname, ',');
if (p)
*p++ = 0;
if (early_lookup_bdev(devname, &dev))
dev = 0;
if (strncmp(devname, "/dev/", 5) == 0)
devname += 5;
snprintf(comp_name, 63, "/dev/%s", devname);
if (init_stat(comp_name, &stat, 0) == 0 && S_ISBLK(stat.mode))
dev = new_decode_dev(stat.rdev);
if (!dev) {
pr_warn("md: Unknown device name: %s\n", devname);
break;
}
devices[i] = dev;
devname = p;
}
devices[i] = 0;
if (!i)
return;
pr_info("md: Loading %s: %s\n", name, args->device_names);
mddev = md_alloc(mdev, name);
if (IS_ERR(mddev)) {
pr_err("md: md_alloc failed - cannot start array %s\n", name);
return;
}
err = mddev_lock(mddev);
if (err) {
pr_err("md: failed to lock array %s\n", name);
goto out_mddev_put;
}
if (!list_empty(&mddev->disks) || mddev->raid_disks) {
pr_warn("md: Ignoring %s, already autodetected. (Use raid=noautodetect)\n",
name);
goto out_unlock;
}
if (args->level != LEVEL_NONE) {
/* non-persistent */
ainfo.level = args->level;
ainfo.md_minor = args->minor;
ainfo.not_persistent = 1;
ainfo.state = (1 << MD_SB_CLEAN);
ainfo.chunk_size = args->chunk;
while (devices[ainfo.raid_disks])
ainfo.raid_disks++;
}
err = md_set_array_info(mddev, &ainfo);
for (i = 0; i <= MD_SB_DISKS && devices[i]; i++) {
struct mdu_disk_info_s dinfo = {
.major = MAJOR(devices[i]),
.minor = MINOR(devices[i]),
};
if (args->level != LEVEL_NONE) {
dinfo.number = i;
dinfo.raid_disk = i;
dinfo.state =
(1 << MD_DISK_ACTIVE) | (1 << MD_DISK_SYNC);
}
md_add_new_disk(mddev, &dinfo);
}
if (!err)
err = do_md_run(mddev);
if (err)
pr_warn("md: starting %s failed\n", name);
out_unlock:
mddev_unlock(mddev);
out_mddev_put:
mddev_put(mddev);
}
static int __init raid_setup(char *str)
{
int len, pos;
len = strlen(str) + 1;
pos = 0;
while (pos < len) {
char *comma = strchr(str+pos, ',');
int wlen;
if (comma)
wlen = (comma-str)-pos;
else wlen = (len-1)-pos;
if (!strncmp(str, "noautodetect", wlen))
raid_noautodetect = 1;
if (!strncmp(str, "autodetect", wlen))
raid_noautodetect = 0;
if (strncmp(str, "partitionable", wlen)==0)
raid_autopart = 1;
if (strncmp(str, "part", wlen)==0)
raid_autopart = 1;
pos += wlen+1;
}
return 1;
}
__setup("raid=", raid_setup);
__setup("md=", md_setup);
static void __init autodetect_raid(void)
{
/*
* Since we don't want to detect and use half a raid array, we need to
* wait for the known devices to complete their probing
*/
printk(KERN_INFO "md: Waiting for all devices to be available before autodetect\n");
printk(KERN_INFO "md: If you don't use raid, use raid=noautodetect\n");
wait_for_device_probe();
md_autostart_arrays(raid_autopart);
}
void __init md_run_setup(void)
{
int ent;
if (raid_noautodetect)
printk(KERN_INFO "md: Skipping autodetection of RAID arrays. (raid=autodetect will force)\n");
else
autodetect_raid();
for (ent = 0; ent < md_setup_ents; ent++)
md_setup_drive(&md_setup_args[ent]);
}
| linux-master | drivers/md/md-autodetect.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2017 Western Digital Corporation or its affiliates.
*
* This file is released under the GPL.
*/
#include "dm-zoned.h"
#include <linux/module.h>
#include <linux/crc32.h>
#include <linux/sched/mm.h>
#define DM_MSG_PREFIX "zoned metadata"
/*
* Metadata version.
*/
#define DMZ_META_VER 2
/*
* On-disk super block magic.
*/
#define DMZ_MAGIC ((((unsigned int)('D')) << 24) | \
(((unsigned int)('Z')) << 16) | \
(((unsigned int)('B')) << 8) | \
((unsigned int)('D')))
/*
* On disk super block.
* This uses only 512 B but uses on disk a full 4KB block. This block is
* followed on disk by the mapping table of chunks to zones and the bitmap
* blocks indicating zone block validity.
* The overall resulting metadata format is:
* (1) Super block (1 block)
* (2) Chunk mapping table (nr_map_blocks)
* (3) Bitmap blocks (nr_bitmap_blocks)
* All metadata blocks are stored in conventional zones, starting from
* the first conventional zone found on disk.
*/
struct dmz_super {
/* Magic number */
__le32 magic; /* 4 */
/* Metadata version number */
__le32 version; /* 8 */
/* Generation number */
__le64 gen; /* 16 */
/* This block number */
__le64 sb_block; /* 24 */
/* The number of metadata blocks, including this super block */
__le32 nr_meta_blocks; /* 28 */
/* The number of sequential zones reserved for reclaim */
__le32 nr_reserved_seq; /* 32 */
/* The number of entries in the mapping table */
__le32 nr_chunks; /* 36 */
/* The number of blocks used for the chunk mapping table */
__le32 nr_map_blocks; /* 40 */
/* The number of blocks used for the block bitmaps */
__le32 nr_bitmap_blocks; /* 44 */
/* Checksum */
__le32 crc; /* 48 */
/* DM-Zoned label */
u8 dmz_label[32]; /* 80 */
/* DM-Zoned UUID */
u8 dmz_uuid[16]; /* 96 */
/* Device UUID */
u8 dev_uuid[16]; /* 112 */
/* Padding to full 512B sector */
u8 reserved[400]; /* 512 */
};
/*
* Chunk mapping entry: entries are indexed by chunk number
* and give the zone ID (dzone_id) mapping the chunk on disk.
* This zone may be sequential or random. If it is a sequential
* zone, a second zone (bzone_id) used as a write buffer may
* also be specified. This second zone will always be a randomly
* writeable zone.
*/
struct dmz_map {
__le32 dzone_id;
__le32 bzone_id;
};
/*
* Chunk mapping table metadata: 512 8-bytes entries per 4KB block.
*/
#define DMZ_MAP_ENTRIES (DMZ_BLOCK_SIZE / sizeof(struct dmz_map))
#define DMZ_MAP_ENTRIES_SHIFT (ilog2(DMZ_MAP_ENTRIES))
#define DMZ_MAP_ENTRIES_MASK (DMZ_MAP_ENTRIES - 1)
#define DMZ_MAP_UNMAPPED UINT_MAX
/*
* Meta data block descriptor (for cached metadata blocks).
*/
struct dmz_mblock {
struct rb_node node;
struct list_head link;
sector_t no;
unsigned int ref;
unsigned long state;
struct page *page;
void *data;
};
/*
* Metadata block state flags.
*/
enum {
DMZ_META_DIRTY,
DMZ_META_READING,
DMZ_META_WRITING,
DMZ_META_ERROR,
};
/*
* Super block information (one per metadata set).
*/
struct dmz_sb {
sector_t block;
struct dmz_dev *dev;
struct dmz_mblock *mblk;
struct dmz_super *sb;
struct dm_zone *zone;
};
/*
* In-memory metadata.
*/
struct dmz_metadata {
struct dmz_dev *dev;
unsigned int nr_devs;
char devname[BDEVNAME_SIZE];
char label[BDEVNAME_SIZE];
uuid_t uuid;
sector_t zone_bitmap_size;
unsigned int zone_nr_bitmap_blocks;
unsigned int zone_bits_per_mblk;
sector_t zone_nr_blocks;
sector_t zone_nr_blocks_shift;
sector_t zone_nr_sectors;
sector_t zone_nr_sectors_shift;
unsigned int nr_bitmap_blocks;
unsigned int nr_map_blocks;
unsigned int nr_zones;
unsigned int nr_useable_zones;
unsigned int nr_meta_blocks;
unsigned int nr_meta_zones;
unsigned int nr_data_zones;
unsigned int nr_cache_zones;
unsigned int nr_rnd_zones;
unsigned int nr_reserved_seq;
unsigned int nr_chunks;
/* Zone information array */
struct xarray zones;
struct dmz_sb sb[2];
unsigned int mblk_primary;
unsigned int sb_version;
u64 sb_gen;
unsigned int min_nr_mblks;
unsigned int max_nr_mblks;
atomic_t nr_mblks;
struct rw_semaphore mblk_sem;
struct mutex mblk_flush_lock;
spinlock_t mblk_lock;
struct rb_root mblk_rbtree;
struct list_head mblk_lru_list;
struct list_head mblk_dirty_list;
struct shrinker mblk_shrinker;
/* Zone allocation management */
struct mutex map_lock;
struct dmz_mblock **map_mblk;
unsigned int nr_cache;
atomic_t unmap_nr_cache;
struct list_head unmap_cache_list;
struct list_head map_cache_list;
atomic_t nr_reserved_seq_zones;
struct list_head reserved_seq_zones_list;
wait_queue_head_t free_wq;
};
#define dmz_zmd_info(zmd, format, args...) \
DMINFO("(%s): " format, (zmd)->label, ## args)
#define dmz_zmd_err(zmd, format, args...) \
DMERR("(%s): " format, (zmd)->label, ## args)
#define dmz_zmd_warn(zmd, format, args...) \
DMWARN("(%s): " format, (zmd)->label, ## args)
#define dmz_zmd_debug(zmd, format, args...) \
DMDEBUG("(%s): " format, (zmd)->label, ## args)
/*
* Various accessors
*/
static unsigned int dmz_dev_zone_id(struct dmz_metadata *zmd, struct dm_zone *zone)
{
if (WARN_ON(!zone))
return 0;
return zone->id - zone->dev->zone_offset;
}
sector_t dmz_start_sect(struct dmz_metadata *zmd, struct dm_zone *zone)
{
unsigned int zone_id = dmz_dev_zone_id(zmd, zone);
return (sector_t)zone_id << zmd->zone_nr_sectors_shift;
}
sector_t dmz_start_block(struct dmz_metadata *zmd, struct dm_zone *zone)
{
unsigned int zone_id = dmz_dev_zone_id(zmd, zone);
return (sector_t)zone_id << zmd->zone_nr_blocks_shift;
}
unsigned int dmz_zone_nr_blocks(struct dmz_metadata *zmd)
{
return zmd->zone_nr_blocks;
}
unsigned int dmz_zone_nr_blocks_shift(struct dmz_metadata *zmd)
{
return zmd->zone_nr_blocks_shift;
}
unsigned int dmz_zone_nr_sectors(struct dmz_metadata *zmd)
{
return zmd->zone_nr_sectors;
}
unsigned int dmz_zone_nr_sectors_shift(struct dmz_metadata *zmd)
{
return zmd->zone_nr_sectors_shift;
}
unsigned int dmz_nr_zones(struct dmz_metadata *zmd)
{
return zmd->nr_zones;
}
unsigned int dmz_nr_chunks(struct dmz_metadata *zmd)
{
return zmd->nr_chunks;
}
unsigned int dmz_nr_rnd_zones(struct dmz_metadata *zmd, int idx)
{
return zmd->dev[idx].nr_rnd;
}
unsigned int dmz_nr_unmap_rnd_zones(struct dmz_metadata *zmd, int idx)
{
return atomic_read(&zmd->dev[idx].unmap_nr_rnd);
}
unsigned int dmz_nr_cache_zones(struct dmz_metadata *zmd)
{
return zmd->nr_cache;
}
unsigned int dmz_nr_unmap_cache_zones(struct dmz_metadata *zmd)
{
return atomic_read(&zmd->unmap_nr_cache);
}
unsigned int dmz_nr_seq_zones(struct dmz_metadata *zmd, int idx)
{
return zmd->dev[idx].nr_seq;
}
unsigned int dmz_nr_unmap_seq_zones(struct dmz_metadata *zmd, int idx)
{
return atomic_read(&zmd->dev[idx].unmap_nr_seq);
}
static struct dm_zone *dmz_get(struct dmz_metadata *zmd, unsigned int zone_id)
{
return xa_load(&zmd->zones, zone_id);
}
static struct dm_zone *dmz_insert(struct dmz_metadata *zmd,
unsigned int zone_id, struct dmz_dev *dev)
{
struct dm_zone *zone = kzalloc(sizeof(struct dm_zone), GFP_KERNEL);
if (!zone)
return ERR_PTR(-ENOMEM);
if (xa_insert(&zmd->zones, zone_id, zone, GFP_KERNEL)) {
kfree(zone);
return ERR_PTR(-EBUSY);
}
INIT_LIST_HEAD(&zone->link);
atomic_set(&zone->refcount, 0);
zone->id = zone_id;
zone->chunk = DMZ_MAP_UNMAPPED;
zone->dev = dev;
return zone;
}
const char *dmz_metadata_label(struct dmz_metadata *zmd)
{
return (const char *)zmd->label;
}
bool dmz_check_dev(struct dmz_metadata *zmd)
{
unsigned int i;
for (i = 0; i < zmd->nr_devs; i++) {
if (!dmz_check_bdev(&zmd->dev[i]))
return false;
}
return true;
}
bool dmz_dev_is_dying(struct dmz_metadata *zmd)
{
unsigned int i;
for (i = 0; i < zmd->nr_devs; i++) {
if (dmz_bdev_is_dying(&zmd->dev[i]))
return true;
}
return false;
}
/*
* Lock/unlock mapping table.
* The map lock also protects all the zone lists.
*/
void dmz_lock_map(struct dmz_metadata *zmd)
{
mutex_lock(&zmd->map_lock);
}
void dmz_unlock_map(struct dmz_metadata *zmd)
{
mutex_unlock(&zmd->map_lock);
}
/*
* Lock/unlock metadata access. This is a "read" lock on a semaphore
* that prevents metadata flush from running while metadata are being
* modified. The actual metadata write mutual exclusion is achieved with
* the map lock and zone state management (active and reclaim state are
* mutually exclusive).
*/
void dmz_lock_metadata(struct dmz_metadata *zmd)
{
down_read(&zmd->mblk_sem);
}
void dmz_unlock_metadata(struct dmz_metadata *zmd)
{
up_read(&zmd->mblk_sem);
}
/*
* Lock/unlock flush: prevent concurrent executions
* of dmz_flush_metadata as well as metadata modification in reclaim
* while flush is being executed.
*/
void dmz_lock_flush(struct dmz_metadata *zmd)
{
mutex_lock(&zmd->mblk_flush_lock);
}
void dmz_unlock_flush(struct dmz_metadata *zmd)
{
mutex_unlock(&zmd->mblk_flush_lock);
}
/*
* Allocate a metadata block.
*/
static struct dmz_mblock *dmz_alloc_mblock(struct dmz_metadata *zmd,
sector_t mblk_no)
{
struct dmz_mblock *mblk = NULL;
/* See if we can reuse cached blocks */
if (zmd->max_nr_mblks && atomic_read(&zmd->nr_mblks) > zmd->max_nr_mblks) {
spin_lock(&zmd->mblk_lock);
mblk = list_first_entry_or_null(&zmd->mblk_lru_list,
struct dmz_mblock, link);
if (mblk) {
list_del_init(&mblk->link);
rb_erase(&mblk->node, &zmd->mblk_rbtree);
mblk->no = mblk_no;
}
spin_unlock(&zmd->mblk_lock);
if (mblk)
return mblk;
}
/* Allocate a new block */
mblk = kmalloc(sizeof(struct dmz_mblock), GFP_NOIO);
if (!mblk)
return NULL;
mblk->page = alloc_page(GFP_NOIO);
if (!mblk->page) {
kfree(mblk);
return NULL;
}
RB_CLEAR_NODE(&mblk->node);
INIT_LIST_HEAD(&mblk->link);
mblk->ref = 0;
mblk->state = 0;
mblk->no = mblk_no;
mblk->data = page_address(mblk->page);
atomic_inc(&zmd->nr_mblks);
return mblk;
}
/*
* Free a metadata block.
*/
static void dmz_free_mblock(struct dmz_metadata *zmd, struct dmz_mblock *mblk)
{
__free_pages(mblk->page, 0);
kfree(mblk);
atomic_dec(&zmd->nr_mblks);
}
/*
* Insert a metadata block in the rbtree.
*/
static void dmz_insert_mblock(struct dmz_metadata *zmd, struct dmz_mblock *mblk)
{
struct rb_root *root = &zmd->mblk_rbtree;
struct rb_node **new = &(root->rb_node), *parent = NULL;
struct dmz_mblock *b;
/* Figure out where to put the new node */
while (*new) {
b = container_of(*new, struct dmz_mblock, node);
parent = *new;
new = (b->no < mblk->no) ? &((*new)->rb_left) : &((*new)->rb_right);
}
/* Add new node and rebalance tree */
rb_link_node(&mblk->node, parent, new);
rb_insert_color(&mblk->node, root);
}
/*
* Lookup a metadata block in the rbtree. If the block is found, increment
* its reference count.
*/
static struct dmz_mblock *dmz_get_mblock_fast(struct dmz_metadata *zmd,
sector_t mblk_no)
{
struct rb_root *root = &zmd->mblk_rbtree;
struct rb_node *node = root->rb_node;
struct dmz_mblock *mblk;
while (node) {
mblk = container_of(node, struct dmz_mblock, node);
if (mblk->no == mblk_no) {
/*
* If this is the first reference to the block,
* remove it from the LRU list.
*/
mblk->ref++;
if (mblk->ref == 1 &&
!test_bit(DMZ_META_DIRTY, &mblk->state))
list_del_init(&mblk->link);
return mblk;
}
node = (mblk->no < mblk_no) ? node->rb_left : node->rb_right;
}
return NULL;
}
/*
* Metadata block BIO end callback.
*/
static void dmz_mblock_bio_end_io(struct bio *bio)
{
struct dmz_mblock *mblk = bio->bi_private;
int flag;
if (bio->bi_status)
set_bit(DMZ_META_ERROR, &mblk->state);
if (bio_op(bio) == REQ_OP_WRITE)
flag = DMZ_META_WRITING;
else
flag = DMZ_META_READING;
clear_bit_unlock(flag, &mblk->state);
smp_mb__after_atomic();
wake_up_bit(&mblk->state, flag);
bio_put(bio);
}
/*
* Read an uncached metadata block from disk and add it to the cache.
*/
static struct dmz_mblock *dmz_get_mblock_slow(struct dmz_metadata *zmd,
sector_t mblk_no)
{
struct dmz_mblock *mblk, *m;
sector_t block = zmd->sb[zmd->mblk_primary].block + mblk_no;
struct dmz_dev *dev = zmd->sb[zmd->mblk_primary].dev;
struct bio *bio;
if (dmz_bdev_is_dying(dev))
return ERR_PTR(-EIO);
/* Get a new block and a BIO to read it */
mblk = dmz_alloc_mblock(zmd, mblk_no);
if (!mblk)
return ERR_PTR(-ENOMEM);
bio = bio_alloc(dev->bdev, 1, REQ_OP_READ | REQ_META | REQ_PRIO,
GFP_NOIO);
spin_lock(&zmd->mblk_lock);
/*
* Make sure that another context did not start reading
* the block already.
*/
m = dmz_get_mblock_fast(zmd, mblk_no);
if (m) {
spin_unlock(&zmd->mblk_lock);
dmz_free_mblock(zmd, mblk);
bio_put(bio);
return m;
}
mblk->ref++;
set_bit(DMZ_META_READING, &mblk->state);
dmz_insert_mblock(zmd, mblk);
spin_unlock(&zmd->mblk_lock);
/* Submit read BIO */
bio->bi_iter.bi_sector = dmz_blk2sect(block);
bio->bi_private = mblk;
bio->bi_end_io = dmz_mblock_bio_end_io;
__bio_add_page(bio, mblk->page, DMZ_BLOCK_SIZE, 0);
submit_bio(bio);
return mblk;
}
/*
* Free metadata blocks.
*/
static unsigned long dmz_shrink_mblock_cache(struct dmz_metadata *zmd,
unsigned long limit)
{
struct dmz_mblock *mblk;
unsigned long count = 0;
if (!zmd->max_nr_mblks)
return 0;
while (!list_empty(&zmd->mblk_lru_list) &&
atomic_read(&zmd->nr_mblks) > zmd->min_nr_mblks &&
count < limit) {
mblk = list_first_entry(&zmd->mblk_lru_list,
struct dmz_mblock, link);
list_del_init(&mblk->link);
rb_erase(&mblk->node, &zmd->mblk_rbtree);
dmz_free_mblock(zmd, mblk);
count++;
}
return count;
}
/*
* For mblock shrinker: get the number of unused metadata blocks in the cache.
*/
static unsigned long dmz_mblock_shrinker_count(struct shrinker *shrink,
struct shrink_control *sc)
{
struct dmz_metadata *zmd = container_of(shrink, struct dmz_metadata, mblk_shrinker);
return atomic_read(&zmd->nr_mblks);
}
/*
* For mblock shrinker: scan unused metadata blocks and shrink the cache.
*/
static unsigned long dmz_mblock_shrinker_scan(struct shrinker *shrink,
struct shrink_control *sc)
{
struct dmz_metadata *zmd = container_of(shrink, struct dmz_metadata, mblk_shrinker);
unsigned long count;
spin_lock(&zmd->mblk_lock);
count = dmz_shrink_mblock_cache(zmd, sc->nr_to_scan);
spin_unlock(&zmd->mblk_lock);
return count ? count : SHRINK_STOP;
}
/*
* Release a metadata block.
*/
static void dmz_release_mblock(struct dmz_metadata *zmd,
struct dmz_mblock *mblk)
{
if (!mblk)
return;
spin_lock(&zmd->mblk_lock);
mblk->ref--;
if (mblk->ref == 0) {
if (test_bit(DMZ_META_ERROR, &mblk->state)) {
rb_erase(&mblk->node, &zmd->mblk_rbtree);
dmz_free_mblock(zmd, mblk);
} else if (!test_bit(DMZ_META_DIRTY, &mblk->state)) {
list_add_tail(&mblk->link, &zmd->mblk_lru_list);
dmz_shrink_mblock_cache(zmd, 1);
}
}
spin_unlock(&zmd->mblk_lock);
}
/*
* Get a metadata block from the rbtree. If the block
* is not present, read it from disk.
*/
static struct dmz_mblock *dmz_get_mblock(struct dmz_metadata *zmd,
sector_t mblk_no)
{
struct dmz_mblock *mblk;
struct dmz_dev *dev = zmd->sb[zmd->mblk_primary].dev;
/* Check rbtree */
spin_lock(&zmd->mblk_lock);
mblk = dmz_get_mblock_fast(zmd, mblk_no);
spin_unlock(&zmd->mblk_lock);
if (!mblk) {
/* Cache miss: read the block from disk */
mblk = dmz_get_mblock_slow(zmd, mblk_no);
if (IS_ERR(mblk))
return mblk;
}
/* Wait for on-going read I/O and check for error */
wait_on_bit_io(&mblk->state, DMZ_META_READING,
TASK_UNINTERRUPTIBLE);
if (test_bit(DMZ_META_ERROR, &mblk->state)) {
dmz_release_mblock(zmd, mblk);
dmz_check_bdev(dev);
return ERR_PTR(-EIO);
}
return mblk;
}
/*
* Mark a metadata block dirty.
*/
static void dmz_dirty_mblock(struct dmz_metadata *zmd, struct dmz_mblock *mblk)
{
spin_lock(&zmd->mblk_lock);
if (!test_and_set_bit(DMZ_META_DIRTY, &mblk->state))
list_add_tail(&mblk->link, &zmd->mblk_dirty_list);
spin_unlock(&zmd->mblk_lock);
}
/*
* Issue a metadata block write BIO.
*/
static int dmz_write_mblock(struct dmz_metadata *zmd, struct dmz_mblock *mblk,
unsigned int set)
{
struct dmz_dev *dev = zmd->sb[set].dev;
sector_t block = zmd->sb[set].block + mblk->no;
struct bio *bio;
if (dmz_bdev_is_dying(dev))
return -EIO;
bio = bio_alloc(dev->bdev, 1, REQ_OP_WRITE | REQ_META | REQ_PRIO,
GFP_NOIO);
set_bit(DMZ_META_WRITING, &mblk->state);
bio->bi_iter.bi_sector = dmz_blk2sect(block);
bio->bi_private = mblk;
bio->bi_end_io = dmz_mblock_bio_end_io;
__bio_add_page(bio, mblk->page, DMZ_BLOCK_SIZE, 0);
submit_bio(bio);
return 0;
}
/*
* Read/write a metadata block.
*/
static int dmz_rdwr_block(struct dmz_dev *dev, enum req_op op,
sector_t block, struct page *page)
{
struct bio *bio;
int ret;
if (WARN_ON(!dev))
return -EIO;
if (dmz_bdev_is_dying(dev))
return -EIO;
bio = bio_alloc(dev->bdev, 1, op | REQ_SYNC | REQ_META | REQ_PRIO,
GFP_NOIO);
bio->bi_iter.bi_sector = dmz_blk2sect(block);
__bio_add_page(bio, page, DMZ_BLOCK_SIZE, 0);
ret = submit_bio_wait(bio);
bio_put(bio);
if (ret)
dmz_check_bdev(dev);
return ret;
}
/*
* Write super block of the specified metadata set.
*/
static int dmz_write_sb(struct dmz_metadata *zmd, unsigned int set)
{
struct dmz_mblock *mblk = zmd->sb[set].mblk;
struct dmz_super *sb = zmd->sb[set].sb;
struct dmz_dev *dev = zmd->sb[set].dev;
sector_t sb_block;
u64 sb_gen = zmd->sb_gen + 1;
int ret;
sb->magic = cpu_to_le32(DMZ_MAGIC);
sb->version = cpu_to_le32(zmd->sb_version);
if (zmd->sb_version > 1) {
BUILD_BUG_ON(UUID_SIZE != 16);
export_uuid(sb->dmz_uuid, &zmd->uuid);
memcpy(sb->dmz_label, zmd->label, BDEVNAME_SIZE);
export_uuid(sb->dev_uuid, &dev->uuid);
}
sb->gen = cpu_to_le64(sb_gen);
/*
* The metadata always references the absolute block address,
* ie relative to the entire block range, not the per-device
* block address.
*/
sb_block = zmd->sb[set].zone->id << zmd->zone_nr_blocks_shift;
sb->sb_block = cpu_to_le64(sb_block);
sb->nr_meta_blocks = cpu_to_le32(zmd->nr_meta_blocks);
sb->nr_reserved_seq = cpu_to_le32(zmd->nr_reserved_seq);
sb->nr_chunks = cpu_to_le32(zmd->nr_chunks);
sb->nr_map_blocks = cpu_to_le32(zmd->nr_map_blocks);
sb->nr_bitmap_blocks = cpu_to_le32(zmd->nr_bitmap_blocks);
sb->crc = 0;
sb->crc = cpu_to_le32(crc32_le(sb_gen, (unsigned char *)sb, DMZ_BLOCK_SIZE));
ret = dmz_rdwr_block(dev, REQ_OP_WRITE, zmd->sb[set].block,
mblk->page);
if (ret == 0)
ret = blkdev_issue_flush(dev->bdev);
return ret;
}
/*
* Write dirty metadata blocks to the specified set.
*/
static int dmz_write_dirty_mblocks(struct dmz_metadata *zmd,
struct list_head *write_list,
unsigned int set)
{
struct dmz_mblock *mblk;
struct dmz_dev *dev = zmd->sb[set].dev;
struct blk_plug plug;
int ret = 0, nr_mblks_submitted = 0;
/* Issue writes */
blk_start_plug(&plug);
list_for_each_entry(mblk, write_list, link) {
ret = dmz_write_mblock(zmd, mblk, set);
if (ret)
break;
nr_mblks_submitted++;
}
blk_finish_plug(&plug);
/* Wait for completion */
list_for_each_entry(mblk, write_list, link) {
if (!nr_mblks_submitted)
break;
wait_on_bit_io(&mblk->state, DMZ_META_WRITING,
TASK_UNINTERRUPTIBLE);
if (test_bit(DMZ_META_ERROR, &mblk->state)) {
clear_bit(DMZ_META_ERROR, &mblk->state);
dmz_check_bdev(dev);
ret = -EIO;
}
nr_mblks_submitted--;
}
/* Flush drive cache (this will also sync data) */
if (ret == 0)
ret = blkdev_issue_flush(dev->bdev);
return ret;
}
/*
* Log dirty metadata blocks.
*/
static int dmz_log_dirty_mblocks(struct dmz_metadata *zmd,
struct list_head *write_list)
{
unsigned int log_set = zmd->mblk_primary ^ 0x1;
int ret;
/* Write dirty blocks to the log */
ret = dmz_write_dirty_mblocks(zmd, write_list, log_set);
if (ret)
return ret;
/*
* No error so far: now validate the log by updating the
* log index super block generation.
*/
ret = dmz_write_sb(zmd, log_set);
if (ret)
return ret;
return 0;
}
/*
* Flush dirty metadata blocks.
*/
int dmz_flush_metadata(struct dmz_metadata *zmd)
{
struct dmz_mblock *mblk;
struct list_head write_list;
struct dmz_dev *dev;
int ret;
if (WARN_ON(!zmd))
return 0;
INIT_LIST_HEAD(&write_list);
/*
* Make sure that metadata blocks are stable before logging: take
* the write lock on the metadata semaphore to prevent target BIOs
* from modifying metadata.
*/
down_write(&zmd->mblk_sem);
dev = zmd->sb[zmd->mblk_primary].dev;
/*
* This is called from the target flush work and reclaim work.
* Concurrent execution is not allowed.
*/
dmz_lock_flush(zmd);
if (dmz_bdev_is_dying(dev)) {
ret = -EIO;
goto out;
}
/* Get dirty blocks */
spin_lock(&zmd->mblk_lock);
list_splice_init(&zmd->mblk_dirty_list, &write_list);
spin_unlock(&zmd->mblk_lock);
/* If there are no dirty metadata blocks, just flush the device cache */
if (list_empty(&write_list)) {
ret = blkdev_issue_flush(dev->bdev);
goto err;
}
/*
* The primary metadata set is still clean. Keep it this way until
* all updates are successful in the secondary set. That is, use
* the secondary set as a log.
*/
ret = dmz_log_dirty_mblocks(zmd, &write_list);
if (ret)
goto err;
/*
* The log is on disk. It is now safe to update in place
* in the primary metadata set.
*/
ret = dmz_write_dirty_mblocks(zmd, &write_list, zmd->mblk_primary);
if (ret)
goto err;
ret = dmz_write_sb(zmd, zmd->mblk_primary);
if (ret)
goto err;
while (!list_empty(&write_list)) {
mblk = list_first_entry(&write_list, struct dmz_mblock, link);
list_del_init(&mblk->link);
spin_lock(&zmd->mblk_lock);
clear_bit(DMZ_META_DIRTY, &mblk->state);
if (mblk->ref == 0)
list_add_tail(&mblk->link, &zmd->mblk_lru_list);
spin_unlock(&zmd->mblk_lock);
}
zmd->sb_gen++;
out:
dmz_unlock_flush(zmd);
up_write(&zmd->mblk_sem);
return ret;
err:
if (!list_empty(&write_list)) {
spin_lock(&zmd->mblk_lock);
list_splice(&write_list, &zmd->mblk_dirty_list);
spin_unlock(&zmd->mblk_lock);
}
if (!dmz_check_bdev(dev))
ret = -EIO;
goto out;
}
/*
* Check super block.
*/
static int dmz_check_sb(struct dmz_metadata *zmd, struct dmz_sb *dsb,
bool tertiary)
{
struct dmz_super *sb = dsb->sb;
struct dmz_dev *dev = dsb->dev;
unsigned int nr_meta_zones, nr_data_zones;
u32 crc, stored_crc;
u64 gen, sb_block;
if (le32_to_cpu(sb->magic) != DMZ_MAGIC) {
dmz_dev_err(dev, "Invalid meta magic (needed 0x%08x, got 0x%08x)",
DMZ_MAGIC, le32_to_cpu(sb->magic));
return -ENXIO;
}
zmd->sb_version = le32_to_cpu(sb->version);
if (zmd->sb_version > DMZ_META_VER) {
dmz_dev_err(dev, "Invalid meta version (needed %d, got %d)",
DMZ_META_VER, zmd->sb_version);
return -EINVAL;
}
if (zmd->sb_version < 2 && tertiary) {
dmz_dev_err(dev, "Tertiary superblocks are not supported");
return -EINVAL;
}
gen = le64_to_cpu(sb->gen);
stored_crc = le32_to_cpu(sb->crc);
sb->crc = 0;
crc = crc32_le(gen, (unsigned char *)sb, DMZ_BLOCK_SIZE);
if (crc != stored_crc) {
dmz_dev_err(dev, "Invalid checksum (needed 0x%08x, got 0x%08x)",
crc, stored_crc);
return -ENXIO;
}
sb_block = le64_to_cpu(sb->sb_block);
if (sb_block != (u64)dsb->zone->id << zmd->zone_nr_blocks_shift) {
dmz_dev_err(dev, "Invalid superblock position (is %llu expected %llu)",
sb_block, (u64)dsb->zone->id << zmd->zone_nr_blocks_shift);
return -EINVAL;
}
if (zmd->sb_version > 1) {
uuid_t sb_uuid;
import_uuid(&sb_uuid, sb->dmz_uuid);
if (uuid_is_null(&sb_uuid)) {
dmz_dev_err(dev, "NULL DM-Zoned uuid");
return -ENXIO;
} else if (uuid_is_null(&zmd->uuid)) {
uuid_copy(&zmd->uuid, &sb_uuid);
} else if (!uuid_equal(&zmd->uuid, &sb_uuid)) {
dmz_dev_err(dev, "mismatching DM-Zoned uuid, is %pUl expected %pUl",
&sb_uuid, &zmd->uuid);
return -ENXIO;
}
if (!strlen(zmd->label))
memcpy(zmd->label, sb->dmz_label, BDEVNAME_SIZE);
else if (memcmp(zmd->label, sb->dmz_label, BDEVNAME_SIZE)) {
dmz_dev_err(dev, "mismatching DM-Zoned label, is %s expected %s",
sb->dmz_label, zmd->label);
return -ENXIO;
}
import_uuid(&dev->uuid, sb->dev_uuid);
if (uuid_is_null(&dev->uuid)) {
dmz_dev_err(dev, "NULL device uuid");
return -ENXIO;
}
if (tertiary) {
/*
* Generation number should be 0, but it doesn't
* really matter if it isn't.
*/
if (gen != 0)
dmz_dev_warn(dev, "Invalid generation %llu",
gen);
return 0;
}
}
nr_meta_zones = (le32_to_cpu(sb->nr_meta_blocks) + zmd->zone_nr_blocks - 1)
>> zmd->zone_nr_blocks_shift;
if (!nr_meta_zones ||
(zmd->nr_devs <= 1 && nr_meta_zones >= zmd->nr_rnd_zones) ||
(zmd->nr_devs > 1 && nr_meta_zones >= zmd->nr_cache_zones)) {
dmz_dev_err(dev, "Invalid number of metadata blocks");
return -ENXIO;
}
if (!le32_to_cpu(sb->nr_reserved_seq) ||
le32_to_cpu(sb->nr_reserved_seq) >= (zmd->nr_useable_zones - nr_meta_zones)) {
dmz_dev_err(dev, "Invalid number of reserved sequential zones");
return -ENXIO;
}
nr_data_zones = zmd->nr_useable_zones -
(nr_meta_zones * 2 + le32_to_cpu(sb->nr_reserved_seq));
if (le32_to_cpu(sb->nr_chunks) > nr_data_zones) {
dmz_dev_err(dev, "Invalid number of chunks %u / %u",
le32_to_cpu(sb->nr_chunks), nr_data_zones);
return -ENXIO;
}
/* OK */
zmd->nr_meta_blocks = le32_to_cpu(sb->nr_meta_blocks);
zmd->nr_reserved_seq = le32_to_cpu(sb->nr_reserved_seq);
zmd->nr_chunks = le32_to_cpu(sb->nr_chunks);
zmd->nr_map_blocks = le32_to_cpu(sb->nr_map_blocks);
zmd->nr_bitmap_blocks = le32_to_cpu(sb->nr_bitmap_blocks);
zmd->nr_meta_zones = nr_meta_zones;
zmd->nr_data_zones = nr_data_zones;
return 0;
}
/*
* Read the first or second super block from disk.
*/
static int dmz_read_sb(struct dmz_metadata *zmd, struct dmz_sb *sb, int set)
{
dmz_zmd_debug(zmd, "read superblock set %d dev %pg block %llu",
set, sb->dev->bdev, sb->block);
return dmz_rdwr_block(sb->dev, REQ_OP_READ,
sb->block, sb->mblk->page);
}
/*
* Determine the position of the secondary super blocks on disk.
* This is used only if a corruption of the primary super block
* is detected.
*/
static int dmz_lookup_secondary_sb(struct dmz_metadata *zmd)
{
unsigned int zone_nr_blocks = zmd->zone_nr_blocks;
struct dmz_mblock *mblk;
unsigned int zone_id = zmd->sb[0].zone->id;
int i;
/* Allocate a block */
mblk = dmz_alloc_mblock(zmd, 0);
if (!mblk)
return -ENOMEM;
zmd->sb[1].mblk = mblk;
zmd->sb[1].sb = mblk->data;
/* Bad first super block: search for the second one */
zmd->sb[1].block = zmd->sb[0].block + zone_nr_blocks;
zmd->sb[1].zone = dmz_get(zmd, zone_id + 1);
zmd->sb[1].dev = zmd->sb[0].dev;
for (i = 1; i < zmd->nr_rnd_zones; i++) {
if (dmz_read_sb(zmd, &zmd->sb[1], 1) != 0)
break;
if (le32_to_cpu(zmd->sb[1].sb->magic) == DMZ_MAGIC)
return 0;
zmd->sb[1].block += zone_nr_blocks;
zmd->sb[1].zone = dmz_get(zmd, zone_id + i);
}
dmz_free_mblock(zmd, mblk);
zmd->sb[1].mblk = NULL;
zmd->sb[1].zone = NULL;
zmd->sb[1].dev = NULL;
return -EIO;
}
/*
* Read a super block from disk.
*/
static int dmz_get_sb(struct dmz_metadata *zmd, struct dmz_sb *sb, int set)
{
struct dmz_mblock *mblk;
int ret;
/* Allocate a block */
mblk = dmz_alloc_mblock(zmd, 0);
if (!mblk)
return -ENOMEM;
sb->mblk = mblk;
sb->sb = mblk->data;
/* Read super block */
ret = dmz_read_sb(zmd, sb, set);
if (ret) {
dmz_free_mblock(zmd, mblk);
sb->mblk = NULL;
return ret;
}
return 0;
}
/*
* Recover a metadata set.
*/
static int dmz_recover_mblocks(struct dmz_metadata *zmd, unsigned int dst_set)
{
unsigned int src_set = dst_set ^ 0x1;
struct page *page;
int i, ret;
dmz_dev_warn(zmd->sb[dst_set].dev,
"Metadata set %u invalid: recovering", dst_set);
if (dst_set == 0)
zmd->sb[0].block = dmz_start_block(zmd, zmd->sb[0].zone);
else
zmd->sb[1].block = dmz_start_block(zmd, zmd->sb[1].zone);
page = alloc_page(GFP_NOIO);
if (!page)
return -ENOMEM;
/* Copy metadata blocks */
for (i = 1; i < zmd->nr_meta_blocks; i++) {
ret = dmz_rdwr_block(zmd->sb[src_set].dev, REQ_OP_READ,
zmd->sb[src_set].block + i, page);
if (ret)
goto out;
ret = dmz_rdwr_block(zmd->sb[dst_set].dev, REQ_OP_WRITE,
zmd->sb[dst_set].block + i, page);
if (ret)
goto out;
}
/* Finalize with the super block */
if (!zmd->sb[dst_set].mblk) {
zmd->sb[dst_set].mblk = dmz_alloc_mblock(zmd, 0);
if (!zmd->sb[dst_set].mblk) {
ret = -ENOMEM;
goto out;
}
zmd->sb[dst_set].sb = zmd->sb[dst_set].mblk->data;
}
ret = dmz_write_sb(zmd, dst_set);
out:
__free_pages(page, 0);
return ret;
}
/*
* Get super block from disk.
*/
static int dmz_load_sb(struct dmz_metadata *zmd)
{
bool sb_good[2] = {false, false};
u64 sb_gen[2] = {0, 0};
int ret;
if (!zmd->sb[0].zone) {
dmz_zmd_err(zmd, "Primary super block zone not set");
return -ENXIO;
}
/* Read and check the primary super block */
zmd->sb[0].block = dmz_start_block(zmd, zmd->sb[0].zone);
zmd->sb[0].dev = zmd->sb[0].zone->dev;
ret = dmz_get_sb(zmd, &zmd->sb[0], 0);
if (ret) {
dmz_dev_err(zmd->sb[0].dev, "Read primary super block failed");
return ret;
}
ret = dmz_check_sb(zmd, &zmd->sb[0], false);
/* Read and check secondary super block */
if (ret == 0) {
sb_good[0] = true;
if (!zmd->sb[1].zone) {
unsigned int zone_id =
zmd->sb[0].zone->id + zmd->nr_meta_zones;
zmd->sb[1].zone = dmz_get(zmd, zone_id);
}
zmd->sb[1].block = dmz_start_block(zmd, zmd->sb[1].zone);
zmd->sb[1].dev = zmd->sb[0].dev;
ret = dmz_get_sb(zmd, &zmd->sb[1], 1);
} else
ret = dmz_lookup_secondary_sb(zmd);
if (ret) {
dmz_dev_err(zmd->sb[1].dev, "Read secondary super block failed");
return ret;
}
ret = dmz_check_sb(zmd, &zmd->sb[1], false);
if (ret == 0)
sb_good[1] = true;
/* Use highest generation sb first */
if (!sb_good[0] && !sb_good[1]) {
dmz_zmd_err(zmd, "No valid super block found");
return -EIO;
}
if (sb_good[0])
sb_gen[0] = le64_to_cpu(zmd->sb[0].sb->gen);
else {
ret = dmz_recover_mblocks(zmd, 0);
if (ret) {
dmz_dev_err(zmd->sb[0].dev,
"Recovery of superblock 0 failed");
return -EIO;
}
}
if (sb_good[1])
sb_gen[1] = le64_to_cpu(zmd->sb[1].sb->gen);
else {
ret = dmz_recover_mblocks(zmd, 1);
if (ret) {
dmz_dev_err(zmd->sb[1].dev,
"Recovery of superblock 1 failed");
return -EIO;
}
}
if (sb_gen[0] >= sb_gen[1]) {
zmd->sb_gen = sb_gen[0];
zmd->mblk_primary = 0;
} else {
zmd->sb_gen = sb_gen[1];
zmd->mblk_primary = 1;
}
dmz_dev_debug(zmd->sb[zmd->mblk_primary].dev,
"Using super block %u (gen %llu)",
zmd->mblk_primary, zmd->sb_gen);
if (zmd->sb_version > 1) {
int i;
struct dmz_sb *sb;
sb = kzalloc(sizeof(struct dmz_sb), GFP_KERNEL);
if (!sb)
return -ENOMEM;
for (i = 1; i < zmd->nr_devs; i++) {
sb->block = 0;
sb->zone = dmz_get(zmd, zmd->dev[i].zone_offset);
sb->dev = &zmd->dev[i];
if (!dmz_is_meta(sb->zone)) {
dmz_dev_err(sb->dev,
"Tertiary super block zone %u not marked as metadata zone",
sb->zone->id);
ret = -EINVAL;
goto out_kfree;
}
ret = dmz_get_sb(zmd, sb, i + 1);
if (ret) {
dmz_dev_err(sb->dev,
"Read tertiary super block failed");
dmz_free_mblock(zmd, sb->mblk);
goto out_kfree;
}
ret = dmz_check_sb(zmd, sb, true);
dmz_free_mblock(zmd, sb->mblk);
if (ret == -EINVAL)
goto out_kfree;
}
out_kfree:
kfree(sb);
}
return ret;
}
/*
* Initialize a zone descriptor.
*/
static int dmz_init_zone(struct blk_zone *blkz, unsigned int num, void *data)
{
struct dmz_dev *dev = data;
struct dmz_metadata *zmd = dev->metadata;
int idx = num + dev->zone_offset;
struct dm_zone *zone;
zone = dmz_insert(zmd, idx, dev);
if (IS_ERR(zone))
return PTR_ERR(zone);
if (blkz->len != zmd->zone_nr_sectors) {
if (zmd->sb_version > 1) {
/* Ignore the eventual runt (smaller) zone */
set_bit(DMZ_OFFLINE, &zone->flags);
return 0;
} else if (blkz->start + blkz->len == dev->capacity)
return 0;
return -ENXIO;
}
/*
* Devices that have zones with a capacity smaller than the zone size
* (e.g. NVMe zoned namespaces) are not supported.
*/
if (blkz->capacity != blkz->len)
return -ENXIO;
switch (blkz->type) {
case BLK_ZONE_TYPE_CONVENTIONAL:
set_bit(DMZ_RND, &zone->flags);
break;
case BLK_ZONE_TYPE_SEQWRITE_REQ:
case BLK_ZONE_TYPE_SEQWRITE_PREF:
set_bit(DMZ_SEQ, &zone->flags);
break;
default:
return -ENXIO;
}
if (dmz_is_rnd(zone))
zone->wp_block = 0;
else
zone->wp_block = dmz_sect2blk(blkz->wp - blkz->start);
if (blkz->cond == BLK_ZONE_COND_OFFLINE)
set_bit(DMZ_OFFLINE, &zone->flags);
else if (blkz->cond == BLK_ZONE_COND_READONLY)
set_bit(DMZ_READ_ONLY, &zone->flags);
else {
zmd->nr_useable_zones++;
if (dmz_is_rnd(zone)) {
zmd->nr_rnd_zones++;
if (zmd->nr_devs == 1 && !zmd->sb[0].zone) {
/* Primary super block zone */
zmd->sb[0].zone = zone;
}
}
if (zmd->nr_devs > 1 && num == 0) {
/*
* Tertiary superblock zones are always at the
* start of the zoned devices, so mark them
* as metadata zone.
*/
set_bit(DMZ_META, &zone->flags);
}
}
return 0;
}
static int dmz_emulate_zones(struct dmz_metadata *zmd, struct dmz_dev *dev)
{
int idx;
sector_t zone_offset = 0;
for (idx = 0; idx < dev->nr_zones; idx++) {
struct dm_zone *zone;
zone = dmz_insert(zmd, idx, dev);
if (IS_ERR(zone))
return PTR_ERR(zone);
set_bit(DMZ_CACHE, &zone->flags);
zone->wp_block = 0;
zmd->nr_cache_zones++;
zmd->nr_useable_zones++;
if (dev->capacity - zone_offset < zmd->zone_nr_sectors) {
/* Disable runt zone */
set_bit(DMZ_OFFLINE, &zone->flags);
break;
}
zone_offset += zmd->zone_nr_sectors;
}
return 0;
}
/*
* Free zones descriptors.
*/
static void dmz_drop_zones(struct dmz_metadata *zmd)
{
int idx;
for (idx = 0; idx < zmd->nr_zones; idx++) {
struct dm_zone *zone = xa_load(&zmd->zones, idx);
kfree(zone);
xa_erase(&zmd->zones, idx);
}
xa_destroy(&zmd->zones);
}
/*
* Allocate and initialize zone descriptors using the zone
* information from disk.
*/
static int dmz_init_zones(struct dmz_metadata *zmd)
{
int i, ret;
struct dmz_dev *zoned_dev = &zmd->dev[0];
/* Init */
zmd->zone_nr_sectors = zmd->dev[0].zone_nr_sectors;
zmd->zone_nr_sectors_shift = ilog2(zmd->zone_nr_sectors);
zmd->zone_nr_blocks = dmz_sect2blk(zmd->zone_nr_sectors);
zmd->zone_nr_blocks_shift = ilog2(zmd->zone_nr_blocks);
zmd->zone_bitmap_size = zmd->zone_nr_blocks >> 3;
zmd->zone_nr_bitmap_blocks =
max_t(sector_t, 1, zmd->zone_bitmap_size >> DMZ_BLOCK_SHIFT);
zmd->zone_bits_per_mblk = min_t(sector_t, zmd->zone_nr_blocks,
DMZ_BLOCK_SIZE_BITS);
/* Allocate zone array */
zmd->nr_zones = 0;
for (i = 0; i < zmd->nr_devs; i++) {
struct dmz_dev *dev = &zmd->dev[i];
dev->metadata = zmd;
zmd->nr_zones += dev->nr_zones;
atomic_set(&dev->unmap_nr_rnd, 0);
INIT_LIST_HEAD(&dev->unmap_rnd_list);
INIT_LIST_HEAD(&dev->map_rnd_list);
atomic_set(&dev->unmap_nr_seq, 0);
INIT_LIST_HEAD(&dev->unmap_seq_list);
INIT_LIST_HEAD(&dev->map_seq_list);
}
if (!zmd->nr_zones) {
DMERR("(%s): No zones found", zmd->devname);
return -ENXIO;
}
xa_init(&zmd->zones);
DMDEBUG("(%s): Using %zu B for zone information",
zmd->devname, sizeof(struct dm_zone) * zmd->nr_zones);
if (zmd->nr_devs > 1) {
ret = dmz_emulate_zones(zmd, &zmd->dev[0]);
if (ret < 0) {
DMDEBUG("(%s): Failed to emulate zones, error %d",
zmd->devname, ret);
dmz_drop_zones(zmd);
return ret;
}
/*
* Primary superblock zone is always at zone 0 when multiple
* drives are present.
*/
zmd->sb[0].zone = dmz_get(zmd, 0);
for (i = 1; i < zmd->nr_devs; i++) {
zoned_dev = &zmd->dev[i];
ret = blkdev_report_zones(zoned_dev->bdev, 0,
BLK_ALL_ZONES,
dmz_init_zone, zoned_dev);
if (ret < 0) {
DMDEBUG("(%s): Failed to report zones, error %d",
zmd->devname, ret);
dmz_drop_zones(zmd);
return ret;
}
}
return 0;
}
/*
* Get zone information and initialize zone descriptors. At the same
* time, determine where the super block should be: first block of the
* first randomly writable zone.
*/
ret = blkdev_report_zones(zoned_dev->bdev, 0, BLK_ALL_ZONES,
dmz_init_zone, zoned_dev);
if (ret < 0) {
DMDEBUG("(%s): Failed to report zones, error %d",
zmd->devname, ret);
dmz_drop_zones(zmd);
return ret;
}
return 0;
}
static int dmz_update_zone_cb(struct blk_zone *blkz, unsigned int idx,
void *data)
{
struct dm_zone *zone = data;
clear_bit(DMZ_OFFLINE, &zone->flags);
clear_bit(DMZ_READ_ONLY, &zone->flags);
if (blkz->cond == BLK_ZONE_COND_OFFLINE)
set_bit(DMZ_OFFLINE, &zone->flags);
else if (blkz->cond == BLK_ZONE_COND_READONLY)
set_bit(DMZ_READ_ONLY, &zone->flags);
if (dmz_is_seq(zone))
zone->wp_block = dmz_sect2blk(blkz->wp - blkz->start);
else
zone->wp_block = 0;
return 0;
}
/*
* Update a zone information.
*/
static int dmz_update_zone(struct dmz_metadata *zmd, struct dm_zone *zone)
{
struct dmz_dev *dev = zone->dev;
unsigned int noio_flag;
int ret;
if (dev->flags & DMZ_BDEV_REGULAR)
return 0;
/*
* Get zone information from disk. Since blkdev_report_zones() uses
* GFP_KERNEL by default for memory allocations, set the per-task
* PF_MEMALLOC_NOIO flag so that all allocations are done as if
* GFP_NOIO was specified.
*/
noio_flag = memalloc_noio_save();
ret = blkdev_report_zones(dev->bdev, dmz_start_sect(zmd, zone), 1,
dmz_update_zone_cb, zone);
memalloc_noio_restore(noio_flag);
if (ret == 0)
ret = -EIO;
if (ret < 0) {
dmz_dev_err(dev, "Get zone %u report failed",
zone->id);
dmz_check_bdev(dev);
return ret;
}
return 0;
}
/*
* Check a zone write pointer position when the zone is marked
* with the sequential write error flag.
*/
static int dmz_handle_seq_write_err(struct dmz_metadata *zmd,
struct dm_zone *zone)
{
struct dmz_dev *dev = zone->dev;
unsigned int wp = 0;
int ret;
wp = zone->wp_block;
ret = dmz_update_zone(zmd, zone);
if (ret)
return ret;
dmz_dev_warn(dev, "Processing zone %u write error (zone wp %u/%u)",
zone->id, zone->wp_block, wp);
if (zone->wp_block < wp) {
dmz_invalidate_blocks(zmd, zone, zone->wp_block,
wp - zone->wp_block);
}
return 0;
}
/*
* Reset a zone write pointer.
*/
static int dmz_reset_zone(struct dmz_metadata *zmd, struct dm_zone *zone)
{
int ret;
/*
* Ignore offline zones, read only zones,
* and conventional zones.
*/
if (dmz_is_offline(zone) ||
dmz_is_readonly(zone) ||
dmz_is_rnd(zone))
return 0;
if (!dmz_is_empty(zone) || dmz_seq_write_err(zone)) {
struct dmz_dev *dev = zone->dev;
ret = blkdev_zone_mgmt(dev->bdev, REQ_OP_ZONE_RESET,
dmz_start_sect(zmd, zone),
zmd->zone_nr_sectors, GFP_NOIO);
if (ret) {
dmz_dev_err(dev, "Reset zone %u failed %d",
zone->id, ret);
return ret;
}
}
/* Clear write error bit and rewind write pointer position */
clear_bit(DMZ_SEQ_WRITE_ERR, &zone->flags);
zone->wp_block = 0;
return 0;
}
static void dmz_get_zone_weight(struct dmz_metadata *zmd, struct dm_zone *zone);
/*
* Initialize chunk mapping.
*/
static int dmz_load_mapping(struct dmz_metadata *zmd)
{
struct dm_zone *dzone, *bzone;
struct dmz_mblock *dmap_mblk = NULL;
struct dmz_map *dmap;
unsigned int i = 0, e = 0, chunk = 0;
unsigned int dzone_id;
unsigned int bzone_id;
/* Metadata block array for the chunk mapping table */
zmd->map_mblk = kcalloc(zmd->nr_map_blocks,
sizeof(struct dmz_mblk *), GFP_KERNEL);
if (!zmd->map_mblk)
return -ENOMEM;
/* Get chunk mapping table blocks and initialize zone mapping */
while (chunk < zmd->nr_chunks) {
if (!dmap_mblk) {
/* Get mapping block */
dmap_mblk = dmz_get_mblock(zmd, i + 1);
if (IS_ERR(dmap_mblk))
return PTR_ERR(dmap_mblk);
zmd->map_mblk[i] = dmap_mblk;
dmap = dmap_mblk->data;
i++;
e = 0;
}
/* Check data zone */
dzone_id = le32_to_cpu(dmap[e].dzone_id);
if (dzone_id == DMZ_MAP_UNMAPPED)
goto next;
if (dzone_id >= zmd->nr_zones) {
dmz_zmd_err(zmd, "Chunk %u mapping: invalid data zone ID %u",
chunk, dzone_id);
return -EIO;
}
dzone = dmz_get(zmd, dzone_id);
if (!dzone) {
dmz_zmd_err(zmd, "Chunk %u mapping: data zone %u not present",
chunk, dzone_id);
return -EIO;
}
set_bit(DMZ_DATA, &dzone->flags);
dzone->chunk = chunk;
dmz_get_zone_weight(zmd, dzone);
if (dmz_is_cache(dzone))
list_add_tail(&dzone->link, &zmd->map_cache_list);
else if (dmz_is_rnd(dzone))
list_add_tail(&dzone->link, &dzone->dev->map_rnd_list);
else
list_add_tail(&dzone->link, &dzone->dev->map_seq_list);
/* Check buffer zone */
bzone_id = le32_to_cpu(dmap[e].bzone_id);
if (bzone_id == DMZ_MAP_UNMAPPED)
goto next;
if (bzone_id >= zmd->nr_zones) {
dmz_zmd_err(zmd, "Chunk %u mapping: invalid buffer zone ID %u",
chunk, bzone_id);
return -EIO;
}
bzone = dmz_get(zmd, bzone_id);
if (!bzone) {
dmz_zmd_err(zmd, "Chunk %u mapping: buffer zone %u not present",
chunk, bzone_id);
return -EIO;
}
if (!dmz_is_rnd(bzone) && !dmz_is_cache(bzone)) {
dmz_zmd_err(zmd, "Chunk %u mapping: invalid buffer zone %u",
chunk, bzone_id);
return -EIO;
}
set_bit(DMZ_DATA, &bzone->flags);
set_bit(DMZ_BUF, &bzone->flags);
bzone->chunk = chunk;
bzone->bzone = dzone;
dzone->bzone = bzone;
dmz_get_zone_weight(zmd, bzone);
if (dmz_is_cache(bzone))
list_add_tail(&bzone->link, &zmd->map_cache_list);
else
list_add_tail(&bzone->link, &bzone->dev->map_rnd_list);
next:
chunk++;
e++;
if (e >= DMZ_MAP_ENTRIES)
dmap_mblk = NULL;
}
/*
* At this point, only meta zones and mapped data zones were
* fully initialized. All remaining zones are unmapped data
* zones. Finish initializing those here.
*/
for (i = 0; i < zmd->nr_zones; i++) {
dzone = dmz_get(zmd, i);
if (!dzone)
continue;
if (dmz_is_meta(dzone))
continue;
if (dmz_is_offline(dzone))
continue;
if (dmz_is_cache(dzone))
zmd->nr_cache++;
else if (dmz_is_rnd(dzone))
dzone->dev->nr_rnd++;
else
dzone->dev->nr_seq++;
if (dmz_is_data(dzone)) {
/* Already initialized */
continue;
}
/* Unmapped data zone */
set_bit(DMZ_DATA, &dzone->flags);
dzone->chunk = DMZ_MAP_UNMAPPED;
if (dmz_is_cache(dzone)) {
list_add_tail(&dzone->link, &zmd->unmap_cache_list);
atomic_inc(&zmd->unmap_nr_cache);
} else if (dmz_is_rnd(dzone)) {
list_add_tail(&dzone->link,
&dzone->dev->unmap_rnd_list);
atomic_inc(&dzone->dev->unmap_nr_rnd);
} else if (atomic_read(&zmd->nr_reserved_seq_zones) < zmd->nr_reserved_seq) {
list_add_tail(&dzone->link, &zmd->reserved_seq_zones_list);
set_bit(DMZ_RESERVED, &dzone->flags);
atomic_inc(&zmd->nr_reserved_seq_zones);
dzone->dev->nr_seq--;
} else {
list_add_tail(&dzone->link,
&dzone->dev->unmap_seq_list);
atomic_inc(&dzone->dev->unmap_nr_seq);
}
}
return 0;
}
/*
* Set a data chunk mapping.
*/
static void dmz_set_chunk_mapping(struct dmz_metadata *zmd, unsigned int chunk,
unsigned int dzone_id, unsigned int bzone_id)
{
struct dmz_mblock *dmap_mblk = zmd->map_mblk[chunk >> DMZ_MAP_ENTRIES_SHIFT];
struct dmz_map *dmap = dmap_mblk->data;
int map_idx = chunk & DMZ_MAP_ENTRIES_MASK;
dmap[map_idx].dzone_id = cpu_to_le32(dzone_id);
dmap[map_idx].bzone_id = cpu_to_le32(bzone_id);
dmz_dirty_mblock(zmd, dmap_mblk);
}
/*
* The list of mapped zones is maintained in LRU order.
* This rotates a zone at the end of its map list.
*/
static void __dmz_lru_zone(struct dmz_metadata *zmd, struct dm_zone *zone)
{
if (list_empty(&zone->link))
return;
list_del_init(&zone->link);
if (dmz_is_seq(zone)) {
/* LRU rotate sequential zone */
list_add_tail(&zone->link, &zone->dev->map_seq_list);
} else if (dmz_is_cache(zone)) {
/* LRU rotate cache zone */
list_add_tail(&zone->link, &zmd->map_cache_list);
} else {
/* LRU rotate random zone */
list_add_tail(&zone->link, &zone->dev->map_rnd_list);
}
}
/*
* The list of mapped random zones is maintained
* in LRU order. This rotates a zone at the end of the list.
*/
static void dmz_lru_zone(struct dmz_metadata *zmd, struct dm_zone *zone)
{
__dmz_lru_zone(zmd, zone);
if (zone->bzone)
__dmz_lru_zone(zmd, zone->bzone);
}
/*
* Wait for any zone to be freed.
*/
static void dmz_wait_for_free_zones(struct dmz_metadata *zmd)
{
DEFINE_WAIT(wait);
prepare_to_wait(&zmd->free_wq, &wait, TASK_UNINTERRUPTIBLE);
dmz_unlock_map(zmd);
dmz_unlock_metadata(zmd);
io_schedule_timeout(HZ);
dmz_lock_metadata(zmd);
dmz_lock_map(zmd);
finish_wait(&zmd->free_wq, &wait);
}
/*
* Lock a zone for reclaim (set the zone RECLAIM bit).
* Returns false if the zone cannot be locked or if it is already locked
* and 1 otherwise.
*/
int dmz_lock_zone_reclaim(struct dm_zone *zone)
{
/* Active zones cannot be reclaimed */
if (dmz_is_active(zone))
return 0;
return !test_and_set_bit(DMZ_RECLAIM, &zone->flags);
}
/*
* Clear a zone reclaim flag.
*/
void dmz_unlock_zone_reclaim(struct dm_zone *zone)
{
WARN_ON(dmz_is_active(zone));
WARN_ON(!dmz_in_reclaim(zone));
clear_bit_unlock(DMZ_RECLAIM, &zone->flags);
smp_mb__after_atomic();
wake_up_bit(&zone->flags, DMZ_RECLAIM);
}
/*
* Wait for a zone reclaim to complete.
*/
static void dmz_wait_for_reclaim(struct dmz_metadata *zmd, struct dm_zone *zone)
{
dmz_unlock_map(zmd);
dmz_unlock_metadata(zmd);
set_bit(DMZ_RECLAIM_TERMINATE, &zone->flags);
wait_on_bit_timeout(&zone->flags, DMZ_RECLAIM, TASK_UNINTERRUPTIBLE, HZ);
clear_bit(DMZ_RECLAIM_TERMINATE, &zone->flags);
dmz_lock_metadata(zmd);
dmz_lock_map(zmd);
}
/*
* Select a cache or random write zone for reclaim.
*/
static struct dm_zone *dmz_get_rnd_zone_for_reclaim(struct dmz_metadata *zmd,
unsigned int idx, bool idle)
{
struct dm_zone *dzone = NULL;
struct dm_zone *zone, *maxw_z = NULL;
struct list_head *zone_list;
/* If we have cache zones select from the cache zone list */
if (zmd->nr_cache) {
zone_list = &zmd->map_cache_list;
/* Try to relaim random zones, too, when idle */
if (idle && list_empty(zone_list))
zone_list = &zmd->dev[idx].map_rnd_list;
} else
zone_list = &zmd->dev[idx].map_rnd_list;
/*
* Find the buffer zone with the heaviest weight or the first (oldest)
* data zone that can be reclaimed.
*/
list_for_each_entry(zone, zone_list, link) {
if (dmz_is_buf(zone)) {
dzone = zone->bzone;
if (dmz_is_rnd(dzone) && dzone->dev->dev_idx != idx)
continue;
if (!maxw_z || maxw_z->weight < dzone->weight)
maxw_z = dzone;
} else {
dzone = zone;
if (dmz_lock_zone_reclaim(dzone))
return dzone;
}
}
if (maxw_z && dmz_lock_zone_reclaim(maxw_z))
return maxw_z;
/*
* If we come here, none of the zones inspected could be locked for
* reclaim. Try again, being more aggressive, that is, find the
* first zone that can be reclaimed regardless of its weitght.
*/
list_for_each_entry(zone, zone_list, link) {
if (dmz_is_buf(zone)) {
dzone = zone->bzone;
if (dmz_is_rnd(dzone) && dzone->dev->dev_idx != idx)
continue;
} else
dzone = zone;
if (dmz_lock_zone_reclaim(dzone))
return dzone;
}
return NULL;
}
/*
* Select a buffered sequential zone for reclaim.
*/
static struct dm_zone *dmz_get_seq_zone_for_reclaim(struct dmz_metadata *zmd,
unsigned int idx)
{
struct dm_zone *zone;
list_for_each_entry(zone, &zmd->dev[idx].map_seq_list, link) {
if (!zone->bzone)
continue;
if (dmz_lock_zone_reclaim(zone))
return zone;
}
return NULL;
}
/*
* Select a zone for reclaim.
*/
struct dm_zone *dmz_get_zone_for_reclaim(struct dmz_metadata *zmd,
unsigned int dev_idx, bool idle)
{
struct dm_zone *zone = NULL;
/*
* Search for a zone candidate to reclaim: 2 cases are possible.
* (1) There is no free sequential zones. Then a random data zone
* cannot be reclaimed. So choose a sequential zone to reclaim so
* that afterward a random zone can be reclaimed.
* (2) At least one free sequential zone is available, then choose
* the oldest random zone (data or buffer) that can be locked.
*/
dmz_lock_map(zmd);
if (list_empty(&zmd->reserved_seq_zones_list))
zone = dmz_get_seq_zone_for_reclaim(zmd, dev_idx);
if (!zone)
zone = dmz_get_rnd_zone_for_reclaim(zmd, dev_idx, idle);
dmz_unlock_map(zmd);
return zone;
}
/*
* Get the zone mapping a chunk, if the chunk is mapped already.
* If no mapping exist and the operation is WRITE, a zone is
* allocated and used to map the chunk.
* The zone returned will be set to the active state.
*/
struct dm_zone *dmz_get_chunk_mapping(struct dmz_metadata *zmd,
unsigned int chunk, enum req_op op)
{
struct dmz_mblock *dmap_mblk = zmd->map_mblk[chunk >> DMZ_MAP_ENTRIES_SHIFT];
struct dmz_map *dmap = dmap_mblk->data;
int dmap_idx = chunk & DMZ_MAP_ENTRIES_MASK;
unsigned int dzone_id;
struct dm_zone *dzone = NULL;
int ret = 0;
int alloc_flags = zmd->nr_cache ? DMZ_ALLOC_CACHE : DMZ_ALLOC_RND;
dmz_lock_map(zmd);
again:
/* Get the chunk mapping */
dzone_id = le32_to_cpu(dmap[dmap_idx].dzone_id);
if (dzone_id == DMZ_MAP_UNMAPPED) {
/*
* Read or discard in unmapped chunks are fine. But for
* writes, we need a mapping, so get one.
*/
if (op != REQ_OP_WRITE)
goto out;
/* Allocate a random zone */
dzone = dmz_alloc_zone(zmd, 0, alloc_flags);
if (!dzone) {
if (dmz_dev_is_dying(zmd)) {
dzone = ERR_PTR(-EIO);
goto out;
}
dmz_wait_for_free_zones(zmd);
goto again;
}
dmz_map_zone(zmd, dzone, chunk);
} else {
/* The chunk is already mapped: get the mapping zone */
dzone = dmz_get(zmd, dzone_id);
if (!dzone) {
dzone = ERR_PTR(-EIO);
goto out;
}
if (dzone->chunk != chunk) {
dzone = ERR_PTR(-EIO);
goto out;
}
/* Repair write pointer if the sequential dzone has error */
if (dmz_seq_write_err(dzone)) {
ret = dmz_handle_seq_write_err(zmd, dzone);
if (ret) {
dzone = ERR_PTR(-EIO);
goto out;
}
clear_bit(DMZ_SEQ_WRITE_ERR, &dzone->flags);
}
}
/*
* If the zone is being reclaimed, the chunk mapping may change
* to a different zone. So wait for reclaim and retry. Otherwise,
* activate the zone (this will prevent reclaim from touching it).
*/
if (dmz_in_reclaim(dzone)) {
dmz_wait_for_reclaim(zmd, dzone);
goto again;
}
dmz_activate_zone(dzone);
dmz_lru_zone(zmd, dzone);
out:
dmz_unlock_map(zmd);
return dzone;
}
/*
* Write and discard change the block validity of data zones and their buffer
* zones. Check here that valid blocks are still present. If all blocks are
* invalid, the zones can be unmapped on the fly without waiting for reclaim
* to do it.
*/
void dmz_put_chunk_mapping(struct dmz_metadata *zmd, struct dm_zone *dzone)
{
struct dm_zone *bzone;
dmz_lock_map(zmd);
bzone = dzone->bzone;
if (bzone) {
if (dmz_weight(bzone))
dmz_lru_zone(zmd, bzone);
else {
/* Empty buffer zone: reclaim it */
dmz_unmap_zone(zmd, bzone);
dmz_free_zone(zmd, bzone);
bzone = NULL;
}
}
/* Deactivate the data zone */
dmz_deactivate_zone(dzone);
if (dmz_is_active(dzone) || bzone || dmz_weight(dzone))
dmz_lru_zone(zmd, dzone);
else {
/* Unbuffered inactive empty data zone: reclaim it */
dmz_unmap_zone(zmd, dzone);
dmz_free_zone(zmd, dzone);
}
dmz_unlock_map(zmd);
}
/*
* Allocate and map a random zone to buffer a chunk
* already mapped to a sequential zone.
*/
struct dm_zone *dmz_get_chunk_buffer(struct dmz_metadata *zmd,
struct dm_zone *dzone)
{
struct dm_zone *bzone;
int alloc_flags = zmd->nr_cache ? DMZ_ALLOC_CACHE : DMZ_ALLOC_RND;
dmz_lock_map(zmd);
again:
bzone = dzone->bzone;
if (bzone)
goto out;
/* Allocate a random zone */
bzone = dmz_alloc_zone(zmd, 0, alloc_flags);
if (!bzone) {
if (dmz_dev_is_dying(zmd)) {
bzone = ERR_PTR(-EIO);
goto out;
}
dmz_wait_for_free_zones(zmd);
goto again;
}
/* Update the chunk mapping */
dmz_set_chunk_mapping(zmd, dzone->chunk, dzone->id, bzone->id);
set_bit(DMZ_BUF, &bzone->flags);
bzone->chunk = dzone->chunk;
bzone->bzone = dzone;
dzone->bzone = bzone;
if (dmz_is_cache(bzone))
list_add_tail(&bzone->link, &zmd->map_cache_list);
else
list_add_tail(&bzone->link, &bzone->dev->map_rnd_list);
out:
dmz_unlock_map(zmd);
return bzone;
}
/*
* Get an unmapped (free) zone.
* This must be called with the mapping lock held.
*/
struct dm_zone *dmz_alloc_zone(struct dmz_metadata *zmd, unsigned int dev_idx,
unsigned long flags)
{
struct list_head *list;
struct dm_zone *zone;
int i;
/* Schedule reclaim to ensure free zones are available */
if (!(flags & DMZ_ALLOC_RECLAIM)) {
for (i = 0; i < zmd->nr_devs; i++)
dmz_schedule_reclaim(zmd->dev[i].reclaim);
}
i = 0;
again:
if (flags & DMZ_ALLOC_CACHE)
list = &zmd->unmap_cache_list;
else if (flags & DMZ_ALLOC_RND)
list = &zmd->dev[dev_idx].unmap_rnd_list;
else
list = &zmd->dev[dev_idx].unmap_seq_list;
if (list_empty(list)) {
/*
* No free zone: return NULL if this is for not reclaim.
*/
if (!(flags & DMZ_ALLOC_RECLAIM))
return NULL;
/*
* Try to allocate from other devices
*/
if (i < zmd->nr_devs) {
dev_idx = (dev_idx + 1) % zmd->nr_devs;
i++;
goto again;
}
/*
* Fallback to the reserved sequential zones
*/
zone = list_first_entry_or_null(&zmd->reserved_seq_zones_list,
struct dm_zone, link);
if (zone) {
list_del_init(&zone->link);
atomic_dec(&zmd->nr_reserved_seq_zones);
}
return zone;
}
zone = list_first_entry(list, struct dm_zone, link);
list_del_init(&zone->link);
if (dmz_is_cache(zone))
atomic_dec(&zmd->unmap_nr_cache);
else if (dmz_is_rnd(zone))
atomic_dec(&zone->dev->unmap_nr_rnd);
else
atomic_dec(&zone->dev->unmap_nr_seq);
if (dmz_is_offline(zone)) {
dmz_zmd_warn(zmd, "Zone %u is offline", zone->id);
zone = NULL;
goto again;
}
if (dmz_is_meta(zone)) {
dmz_zmd_warn(zmd, "Zone %u has metadata", zone->id);
zone = NULL;
goto again;
}
return zone;
}
/*
* Free a zone.
* This must be called with the mapping lock held.
*/
void dmz_free_zone(struct dmz_metadata *zmd, struct dm_zone *zone)
{
/* If this is a sequential zone, reset it */
if (dmz_is_seq(zone))
dmz_reset_zone(zmd, zone);
/* Return the zone to its type unmap list */
if (dmz_is_cache(zone)) {
list_add_tail(&zone->link, &zmd->unmap_cache_list);
atomic_inc(&zmd->unmap_nr_cache);
} else if (dmz_is_rnd(zone)) {
list_add_tail(&zone->link, &zone->dev->unmap_rnd_list);
atomic_inc(&zone->dev->unmap_nr_rnd);
} else if (dmz_is_reserved(zone)) {
list_add_tail(&zone->link, &zmd->reserved_seq_zones_list);
atomic_inc(&zmd->nr_reserved_seq_zones);
} else {
list_add_tail(&zone->link, &zone->dev->unmap_seq_list);
atomic_inc(&zone->dev->unmap_nr_seq);
}
wake_up_all(&zmd->free_wq);
}
/*
* Map a chunk to a zone.
* This must be called with the mapping lock held.
*/
void dmz_map_zone(struct dmz_metadata *zmd, struct dm_zone *dzone,
unsigned int chunk)
{
/* Set the chunk mapping */
dmz_set_chunk_mapping(zmd, chunk, dzone->id,
DMZ_MAP_UNMAPPED);
dzone->chunk = chunk;
if (dmz_is_cache(dzone))
list_add_tail(&dzone->link, &zmd->map_cache_list);
else if (dmz_is_rnd(dzone))
list_add_tail(&dzone->link, &dzone->dev->map_rnd_list);
else
list_add_tail(&dzone->link, &dzone->dev->map_seq_list);
}
/*
* Unmap a zone.
* This must be called with the mapping lock held.
*/
void dmz_unmap_zone(struct dmz_metadata *zmd, struct dm_zone *zone)
{
unsigned int chunk = zone->chunk;
unsigned int dzone_id;
if (chunk == DMZ_MAP_UNMAPPED) {
/* Already unmapped */
return;
}
if (test_and_clear_bit(DMZ_BUF, &zone->flags)) {
/*
* Unmapping the chunk buffer zone: clear only
* the chunk buffer mapping
*/
dzone_id = zone->bzone->id;
zone->bzone->bzone = NULL;
zone->bzone = NULL;
} else {
/*
* Unmapping the chunk data zone: the zone must
* not be buffered.
*/
if (WARN_ON(zone->bzone)) {
zone->bzone->bzone = NULL;
zone->bzone = NULL;
}
dzone_id = DMZ_MAP_UNMAPPED;
}
dmz_set_chunk_mapping(zmd, chunk, dzone_id, DMZ_MAP_UNMAPPED);
zone->chunk = DMZ_MAP_UNMAPPED;
list_del_init(&zone->link);
}
/*
* Set @nr_bits bits in @bitmap starting from @bit.
* Return the number of bits changed from 0 to 1.
*/
static unsigned int dmz_set_bits(unsigned long *bitmap,
unsigned int bit, unsigned int nr_bits)
{
unsigned long *addr;
unsigned int end = bit + nr_bits;
unsigned int n = 0;
while (bit < end) {
if (((bit & (BITS_PER_LONG - 1)) == 0) &&
((end - bit) >= BITS_PER_LONG)) {
/* Try to set the whole word at once */
addr = bitmap + BIT_WORD(bit);
if (*addr == 0) {
*addr = ULONG_MAX;
n += BITS_PER_LONG;
bit += BITS_PER_LONG;
continue;
}
}
if (!test_and_set_bit(bit, bitmap))
n++;
bit++;
}
return n;
}
/*
* Get the bitmap block storing the bit for chunk_block in zone.
*/
static struct dmz_mblock *dmz_get_bitmap(struct dmz_metadata *zmd,
struct dm_zone *zone,
sector_t chunk_block)
{
sector_t bitmap_block = 1 + zmd->nr_map_blocks +
(sector_t)(zone->id * zmd->zone_nr_bitmap_blocks) +
(chunk_block >> DMZ_BLOCK_SHIFT_BITS);
return dmz_get_mblock(zmd, bitmap_block);
}
/*
* Copy the valid blocks bitmap of from_zone to the bitmap of to_zone.
*/
int dmz_copy_valid_blocks(struct dmz_metadata *zmd, struct dm_zone *from_zone,
struct dm_zone *to_zone)
{
struct dmz_mblock *from_mblk, *to_mblk;
sector_t chunk_block = 0;
/* Get the zones bitmap blocks */
while (chunk_block < zmd->zone_nr_blocks) {
from_mblk = dmz_get_bitmap(zmd, from_zone, chunk_block);
if (IS_ERR(from_mblk))
return PTR_ERR(from_mblk);
to_mblk = dmz_get_bitmap(zmd, to_zone, chunk_block);
if (IS_ERR(to_mblk)) {
dmz_release_mblock(zmd, from_mblk);
return PTR_ERR(to_mblk);
}
memcpy(to_mblk->data, from_mblk->data, DMZ_BLOCK_SIZE);
dmz_dirty_mblock(zmd, to_mblk);
dmz_release_mblock(zmd, to_mblk);
dmz_release_mblock(zmd, from_mblk);
chunk_block += zmd->zone_bits_per_mblk;
}
to_zone->weight = from_zone->weight;
return 0;
}
/*
* Merge the valid blocks bitmap of from_zone into the bitmap of to_zone,
* starting from chunk_block.
*/
int dmz_merge_valid_blocks(struct dmz_metadata *zmd, struct dm_zone *from_zone,
struct dm_zone *to_zone, sector_t chunk_block)
{
unsigned int nr_blocks;
int ret;
/* Get the zones bitmap blocks */
while (chunk_block < zmd->zone_nr_blocks) {
/* Get a valid region from the source zone */
ret = dmz_first_valid_block(zmd, from_zone, &chunk_block);
if (ret <= 0)
return ret;
nr_blocks = ret;
ret = dmz_validate_blocks(zmd, to_zone, chunk_block, nr_blocks);
if (ret)
return ret;
chunk_block += nr_blocks;
}
return 0;
}
/*
* Validate all the blocks in the range [block..block+nr_blocks-1].
*/
int dmz_validate_blocks(struct dmz_metadata *zmd, struct dm_zone *zone,
sector_t chunk_block, unsigned int nr_blocks)
{
unsigned int count, bit, nr_bits;
unsigned int zone_nr_blocks = zmd->zone_nr_blocks;
struct dmz_mblock *mblk;
unsigned int n = 0;
dmz_zmd_debug(zmd, "=> VALIDATE zone %u, block %llu, %u blocks",
zone->id, (unsigned long long)chunk_block,
nr_blocks);
WARN_ON(chunk_block + nr_blocks > zone_nr_blocks);
while (nr_blocks) {
/* Get bitmap block */
mblk = dmz_get_bitmap(zmd, zone, chunk_block);
if (IS_ERR(mblk))
return PTR_ERR(mblk);
/* Set bits */
bit = chunk_block & DMZ_BLOCK_MASK_BITS;
nr_bits = min(nr_blocks, zmd->zone_bits_per_mblk - bit);
count = dmz_set_bits((unsigned long *)mblk->data, bit, nr_bits);
if (count) {
dmz_dirty_mblock(zmd, mblk);
n += count;
}
dmz_release_mblock(zmd, mblk);
nr_blocks -= nr_bits;
chunk_block += nr_bits;
}
if (likely(zone->weight + n <= zone_nr_blocks))
zone->weight += n;
else {
dmz_zmd_warn(zmd, "Zone %u: weight %u should be <= %u",
zone->id, zone->weight,
zone_nr_blocks - n);
zone->weight = zone_nr_blocks;
}
return 0;
}
/*
* Clear nr_bits bits in bitmap starting from bit.
* Return the number of bits cleared.
*/
static int dmz_clear_bits(unsigned long *bitmap, int bit, int nr_bits)
{
unsigned long *addr;
int end = bit + nr_bits;
int n = 0;
while (bit < end) {
if (((bit & (BITS_PER_LONG - 1)) == 0) &&
((end - bit) >= BITS_PER_LONG)) {
/* Try to clear whole word at once */
addr = bitmap + BIT_WORD(bit);
if (*addr == ULONG_MAX) {
*addr = 0;
n += BITS_PER_LONG;
bit += BITS_PER_LONG;
continue;
}
}
if (test_and_clear_bit(bit, bitmap))
n++;
bit++;
}
return n;
}
/*
* Invalidate all the blocks in the range [block..block+nr_blocks-1].
*/
int dmz_invalidate_blocks(struct dmz_metadata *zmd, struct dm_zone *zone,
sector_t chunk_block, unsigned int nr_blocks)
{
unsigned int count, bit, nr_bits;
struct dmz_mblock *mblk;
unsigned int n = 0;
dmz_zmd_debug(zmd, "=> INVALIDATE zone %u, block %llu, %u blocks",
zone->id, (u64)chunk_block, nr_blocks);
WARN_ON(chunk_block + nr_blocks > zmd->zone_nr_blocks);
while (nr_blocks) {
/* Get bitmap block */
mblk = dmz_get_bitmap(zmd, zone, chunk_block);
if (IS_ERR(mblk))
return PTR_ERR(mblk);
/* Clear bits */
bit = chunk_block & DMZ_BLOCK_MASK_BITS;
nr_bits = min(nr_blocks, zmd->zone_bits_per_mblk - bit);
count = dmz_clear_bits((unsigned long *)mblk->data,
bit, nr_bits);
if (count) {
dmz_dirty_mblock(zmd, mblk);
n += count;
}
dmz_release_mblock(zmd, mblk);
nr_blocks -= nr_bits;
chunk_block += nr_bits;
}
if (zone->weight >= n)
zone->weight -= n;
else {
dmz_zmd_warn(zmd, "Zone %u: weight %u should be >= %u",
zone->id, zone->weight, n);
zone->weight = 0;
}
return 0;
}
/*
* Get a block bit value.
*/
static int dmz_test_block(struct dmz_metadata *zmd, struct dm_zone *zone,
sector_t chunk_block)
{
struct dmz_mblock *mblk;
int ret;
WARN_ON(chunk_block >= zmd->zone_nr_blocks);
/* Get bitmap block */
mblk = dmz_get_bitmap(zmd, zone, chunk_block);
if (IS_ERR(mblk))
return PTR_ERR(mblk);
/* Get offset */
ret = test_bit(chunk_block & DMZ_BLOCK_MASK_BITS,
(unsigned long *) mblk->data) != 0;
dmz_release_mblock(zmd, mblk);
return ret;
}
/*
* Return the number of blocks from chunk_block to the first block with a bit
* value specified by set. Search at most nr_blocks blocks from chunk_block.
*/
static int dmz_to_next_set_block(struct dmz_metadata *zmd, struct dm_zone *zone,
sector_t chunk_block, unsigned int nr_blocks,
int set)
{
struct dmz_mblock *mblk;
unsigned int bit, set_bit, nr_bits;
unsigned int zone_bits = zmd->zone_bits_per_mblk;
unsigned long *bitmap;
int n = 0;
WARN_ON(chunk_block + nr_blocks > zmd->zone_nr_blocks);
while (nr_blocks) {
/* Get bitmap block */
mblk = dmz_get_bitmap(zmd, zone, chunk_block);
if (IS_ERR(mblk))
return PTR_ERR(mblk);
/* Get offset */
bitmap = (unsigned long *) mblk->data;
bit = chunk_block & DMZ_BLOCK_MASK_BITS;
nr_bits = min(nr_blocks, zone_bits - bit);
if (set)
set_bit = find_next_bit(bitmap, zone_bits, bit);
else
set_bit = find_next_zero_bit(bitmap, zone_bits, bit);
dmz_release_mblock(zmd, mblk);
n += set_bit - bit;
if (set_bit < zone_bits)
break;
nr_blocks -= nr_bits;
chunk_block += nr_bits;
}
return n;
}
/*
* Test if chunk_block is valid. If it is, the number of consecutive
* valid blocks from chunk_block will be returned.
*/
int dmz_block_valid(struct dmz_metadata *zmd, struct dm_zone *zone,
sector_t chunk_block)
{
int valid;
valid = dmz_test_block(zmd, zone, chunk_block);
if (valid <= 0)
return valid;
/* The block is valid: get the number of valid blocks from block */
return dmz_to_next_set_block(zmd, zone, chunk_block,
zmd->zone_nr_blocks - chunk_block, 0);
}
/*
* Find the first valid block from @chunk_block in @zone.
* If such a block is found, its number is returned using
* @chunk_block and the total number of valid blocks from @chunk_block
* is returned.
*/
int dmz_first_valid_block(struct dmz_metadata *zmd, struct dm_zone *zone,
sector_t *chunk_block)
{
sector_t start_block = *chunk_block;
int ret;
ret = dmz_to_next_set_block(zmd, zone, start_block,
zmd->zone_nr_blocks - start_block, 1);
if (ret < 0)
return ret;
start_block += ret;
*chunk_block = start_block;
return dmz_to_next_set_block(zmd, zone, start_block,
zmd->zone_nr_blocks - start_block, 0);
}
/*
* Count the number of bits set starting from bit up to bit + nr_bits - 1.
*/
static int dmz_count_bits(void *bitmap, int bit, int nr_bits)
{
unsigned long *addr;
int end = bit + nr_bits;
int n = 0;
while (bit < end) {
if (((bit & (BITS_PER_LONG - 1)) == 0) &&
((end - bit) >= BITS_PER_LONG)) {
addr = (unsigned long *)bitmap + BIT_WORD(bit);
if (*addr == ULONG_MAX) {
n += BITS_PER_LONG;
bit += BITS_PER_LONG;
continue;
}
}
if (test_bit(bit, bitmap))
n++;
bit++;
}
return n;
}
/*
* Get a zone weight.
*/
static void dmz_get_zone_weight(struct dmz_metadata *zmd, struct dm_zone *zone)
{
struct dmz_mblock *mblk;
sector_t chunk_block = 0;
unsigned int bit, nr_bits;
unsigned int nr_blocks = zmd->zone_nr_blocks;
void *bitmap;
int n = 0;
while (nr_blocks) {
/* Get bitmap block */
mblk = dmz_get_bitmap(zmd, zone, chunk_block);
if (IS_ERR(mblk)) {
n = 0;
break;
}
/* Count bits in this block */
bitmap = mblk->data;
bit = chunk_block & DMZ_BLOCK_MASK_BITS;
nr_bits = min(nr_blocks, zmd->zone_bits_per_mblk - bit);
n += dmz_count_bits(bitmap, bit, nr_bits);
dmz_release_mblock(zmd, mblk);
nr_blocks -= nr_bits;
chunk_block += nr_bits;
}
zone->weight = n;
}
/*
* Cleanup the zoned metadata resources.
*/
static void dmz_cleanup_metadata(struct dmz_metadata *zmd)
{
struct rb_root *root;
struct dmz_mblock *mblk, *next;
int i;
/* Release zone mapping resources */
if (zmd->map_mblk) {
for (i = 0; i < zmd->nr_map_blocks; i++)
dmz_release_mblock(zmd, zmd->map_mblk[i]);
kfree(zmd->map_mblk);
zmd->map_mblk = NULL;
}
/* Release super blocks */
for (i = 0; i < 2; i++) {
if (zmd->sb[i].mblk) {
dmz_free_mblock(zmd, zmd->sb[i].mblk);
zmd->sb[i].mblk = NULL;
}
}
/* Free cached blocks */
while (!list_empty(&zmd->mblk_dirty_list)) {
mblk = list_first_entry(&zmd->mblk_dirty_list,
struct dmz_mblock, link);
dmz_zmd_warn(zmd, "mblock %llu still in dirty list (ref %u)",
(u64)mblk->no, mblk->ref);
list_del_init(&mblk->link);
rb_erase(&mblk->node, &zmd->mblk_rbtree);
dmz_free_mblock(zmd, mblk);
}
while (!list_empty(&zmd->mblk_lru_list)) {
mblk = list_first_entry(&zmd->mblk_lru_list,
struct dmz_mblock, link);
list_del_init(&mblk->link);
rb_erase(&mblk->node, &zmd->mblk_rbtree);
dmz_free_mblock(zmd, mblk);
}
/* Sanity checks: the mblock rbtree should now be empty */
root = &zmd->mblk_rbtree;
rbtree_postorder_for_each_entry_safe(mblk, next, root, node) {
dmz_zmd_warn(zmd, "mblock %llu ref %u still in rbtree",
(u64)mblk->no, mblk->ref);
mblk->ref = 0;
dmz_free_mblock(zmd, mblk);
}
/* Free the zone descriptors */
dmz_drop_zones(zmd);
mutex_destroy(&zmd->mblk_flush_lock);
mutex_destroy(&zmd->map_lock);
}
static void dmz_print_dev(struct dmz_metadata *zmd, int num)
{
struct dmz_dev *dev = &zmd->dev[num];
if (bdev_zoned_model(dev->bdev) == BLK_ZONED_NONE)
dmz_dev_info(dev, "Regular block device");
else
dmz_dev_info(dev, "Host-%s zoned block device",
bdev_zoned_model(dev->bdev) == BLK_ZONED_HA ?
"aware" : "managed");
if (zmd->sb_version > 1) {
sector_t sector_offset =
dev->zone_offset << zmd->zone_nr_sectors_shift;
dmz_dev_info(dev, " %llu 512-byte logical sectors (offset %llu)",
(u64)dev->capacity, (u64)sector_offset);
dmz_dev_info(dev, " %u zones of %llu 512-byte logical sectors (offset %llu)",
dev->nr_zones, (u64)zmd->zone_nr_sectors,
(u64)dev->zone_offset);
} else {
dmz_dev_info(dev, " %llu 512-byte logical sectors",
(u64)dev->capacity);
dmz_dev_info(dev, " %u zones of %llu 512-byte logical sectors",
dev->nr_zones, (u64)zmd->zone_nr_sectors);
}
}
/*
* Initialize the zoned metadata.
*/
int dmz_ctr_metadata(struct dmz_dev *dev, int num_dev,
struct dmz_metadata **metadata,
const char *devname)
{
struct dmz_metadata *zmd;
unsigned int i;
struct dm_zone *zone;
int ret;
zmd = kzalloc(sizeof(struct dmz_metadata), GFP_KERNEL);
if (!zmd)
return -ENOMEM;
strcpy(zmd->devname, devname);
zmd->dev = dev;
zmd->nr_devs = num_dev;
zmd->mblk_rbtree = RB_ROOT;
init_rwsem(&zmd->mblk_sem);
mutex_init(&zmd->mblk_flush_lock);
spin_lock_init(&zmd->mblk_lock);
INIT_LIST_HEAD(&zmd->mblk_lru_list);
INIT_LIST_HEAD(&zmd->mblk_dirty_list);
mutex_init(&zmd->map_lock);
atomic_set(&zmd->unmap_nr_cache, 0);
INIT_LIST_HEAD(&zmd->unmap_cache_list);
INIT_LIST_HEAD(&zmd->map_cache_list);
atomic_set(&zmd->nr_reserved_seq_zones, 0);
INIT_LIST_HEAD(&zmd->reserved_seq_zones_list);
init_waitqueue_head(&zmd->free_wq);
/* Initialize zone descriptors */
ret = dmz_init_zones(zmd);
if (ret)
goto err;
/* Get super block */
ret = dmz_load_sb(zmd);
if (ret)
goto err;
/* Set metadata zones starting from sb_zone */
for (i = 0; i < zmd->nr_meta_zones << 1; i++) {
zone = dmz_get(zmd, zmd->sb[0].zone->id + i);
if (!zone) {
dmz_zmd_err(zmd,
"metadata zone %u not present", i);
ret = -ENXIO;
goto err;
}
if (!dmz_is_rnd(zone) && !dmz_is_cache(zone)) {
dmz_zmd_err(zmd,
"metadata zone %d is not random", i);
ret = -ENXIO;
goto err;
}
set_bit(DMZ_META, &zone->flags);
}
/* Load mapping table */
ret = dmz_load_mapping(zmd);
if (ret)
goto err;
/*
* Cache size boundaries: allow at least 2 super blocks, the chunk map
* blocks and enough blocks to be able to cache the bitmap blocks of
* up to 16 zones when idle (min_nr_mblks). Otherwise, if busy, allow
* the cache to add 512 more metadata blocks.
*/
zmd->min_nr_mblks = 2 + zmd->nr_map_blocks + zmd->zone_nr_bitmap_blocks * 16;
zmd->max_nr_mblks = zmd->min_nr_mblks + 512;
zmd->mblk_shrinker.count_objects = dmz_mblock_shrinker_count;
zmd->mblk_shrinker.scan_objects = dmz_mblock_shrinker_scan;
zmd->mblk_shrinker.seeks = DEFAULT_SEEKS;
/* Metadata cache shrinker */
ret = register_shrinker(&zmd->mblk_shrinker, "dm-zoned-meta:(%u:%u)",
MAJOR(dev->bdev->bd_dev),
MINOR(dev->bdev->bd_dev));
if (ret) {
dmz_zmd_err(zmd, "Register metadata cache shrinker failed");
goto err;
}
dmz_zmd_info(zmd, "DM-Zoned metadata version %d", zmd->sb_version);
for (i = 0; i < zmd->nr_devs; i++)
dmz_print_dev(zmd, i);
dmz_zmd_info(zmd, " %u zones of %llu 512-byte logical sectors",
zmd->nr_zones, (u64)zmd->zone_nr_sectors);
dmz_zmd_debug(zmd, " %u metadata zones",
zmd->nr_meta_zones * 2);
dmz_zmd_debug(zmd, " %u data zones for %u chunks",
zmd->nr_data_zones, zmd->nr_chunks);
dmz_zmd_debug(zmd, " %u cache zones (%u unmapped)",
zmd->nr_cache, atomic_read(&zmd->unmap_nr_cache));
for (i = 0; i < zmd->nr_devs; i++) {
dmz_zmd_debug(zmd, " %u random zones (%u unmapped)",
dmz_nr_rnd_zones(zmd, i),
dmz_nr_unmap_rnd_zones(zmd, i));
dmz_zmd_debug(zmd, " %u sequential zones (%u unmapped)",
dmz_nr_seq_zones(zmd, i),
dmz_nr_unmap_seq_zones(zmd, i));
}
dmz_zmd_debug(zmd, " %u reserved sequential data zones",
zmd->nr_reserved_seq);
dmz_zmd_debug(zmd, "Format:");
dmz_zmd_debug(zmd, "%u metadata blocks per set (%u max cache)",
zmd->nr_meta_blocks, zmd->max_nr_mblks);
dmz_zmd_debug(zmd, " %u data zone mapping blocks",
zmd->nr_map_blocks);
dmz_zmd_debug(zmd, " %u bitmap blocks",
zmd->nr_bitmap_blocks);
*metadata = zmd;
return 0;
err:
dmz_cleanup_metadata(zmd);
kfree(zmd);
*metadata = NULL;
return ret;
}
/*
* Cleanup the zoned metadata resources.
*/
void dmz_dtr_metadata(struct dmz_metadata *zmd)
{
unregister_shrinker(&zmd->mblk_shrinker);
dmz_cleanup_metadata(zmd);
kfree(zmd);
}
/*
* Check zone information on resume.
*/
int dmz_resume_metadata(struct dmz_metadata *zmd)
{
struct dm_zone *zone;
sector_t wp_block;
unsigned int i;
int ret;
/* Check zones */
for (i = 0; i < zmd->nr_zones; i++) {
zone = dmz_get(zmd, i);
if (!zone) {
dmz_zmd_err(zmd, "Unable to get zone %u", i);
return -EIO;
}
wp_block = zone->wp_block;
ret = dmz_update_zone(zmd, zone);
if (ret) {
dmz_zmd_err(zmd, "Broken zone %u", i);
return ret;
}
if (dmz_is_offline(zone)) {
dmz_zmd_warn(zmd, "Zone %u is offline", i);
continue;
}
/* Check write pointer */
if (!dmz_is_seq(zone))
zone->wp_block = 0;
else if (zone->wp_block != wp_block) {
dmz_zmd_err(zmd, "Zone %u: Invalid wp (%llu / %llu)",
i, (u64)zone->wp_block, (u64)wp_block);
zone->wp_block = wp_block;
dmz_invalidate_blocks(zmd, zone, zone->wp_block,
zmd->zone_nr_blocks - zone->wp_block);
}
}
return 0;
}
| linux-master | drivers/md/dm-zoned-metadata.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2003 Sistina Software Limited.
* Copyright (C) 2005-2008 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
#include "dm-bio-record.h"
#include <linux/init.h>
#include <linux/mempool.h>
#include <linux/module.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/device-mapper.h>
#include <linux/dm-io.h>
#include <linux/dm-dirty-log.h>
#include <linux/dm-kcopyd.h>
#include <linux/dm-region-hash.h>
static struct workqueue_struct *dm_raid1_wq;
#define DM_MSG_PREFIX "raid1"
#define MAX_RECOVERY 1 /* Maximum number of regions recovered in parallel. */
#define MAX_NR_MIRRORS (DM_KCOPYD_MAX_REGIONS + 1)
#define DM_RAID1_HANDLE_ERRORS 0x01
#define DM_RAID1_KEEP_LOG 0x02
#define errors_handled(p) ((p)->features & DM_RAID1_HANDLE_ERRORS)
#define keep_log(p) ((p)->features & DM_RAID1_KEEP_LOG)
static DECLARE_WAIT_QUEUE_HEAD(_kmirrord_recovery_stopped);
/*
*---------------------------------------------------------------
* Mirror set structures.
*---------------------------------------------------------------
*/
enum dm_raid1_error {
DM_RAID1_WRITE_ERROR,
DM_RAID1_FLUSH_ERROR,
DM_RAID1_SYNC_ERROR,
DM_RAID1_READ_ERROR
};
struct mirror {
struct mirror_set *ms;
atomic_t error_count;
unsigned long error_type;
struct dm_dev *dev;
sector_t offset;
};
struct mirror_set {
struct dm_target *ti;
struct list_head list;
uint64_t features;
spinlock_t lock; /* protects the lists */
struct bio_list reads;
struct bio_list writes;
struct bio_list failures;
struct bio_list holds; /* bios are waiting until suspend */
struct dm_region_hash *rh;
struct dm_kcopyd_client *kcopyd_client;
struct dm_io_client *io_client;
/* recovery */
region_t nr_regions;
int in_sync;
int log_failure;
int leg_failure;
atomic_t suspend;
atomic_t default_mirror; /* Default mirror */
struct workqueue_struct *kmirrord_wq;
struct work_struct kmirrord_work;
struct timer_list timer;
unsigned long timer_pending;
struct work_struct trigger_event;
unsigned int nr_mirrors;
struct mirror mirror[];
};
DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(raid1_resync_throttle,
"A percentage of time allocated for raid resynchronization");
static void wakeup_mirrord(void *context)
{
struct mirror_set *ms = context;
queue_work(ms->kmirrord_wq, &ms->kmirrord_work);
}
static void delayed_wake_fn(struct timer_list *t)
{
struct mirror_set *ms = from_timer(ms, t, timer);
clear_bit(0, &ms->timer_pending);
wakeup_mirrord(ms);
}
static void delayed_wake(struct mirror_set *ms)
{
if (test_and_set_bit(0, &ms->timer_pending))
return;
ms->timer.expires = jiffies + HZ / 5;
add_timer(&ms->timer);
}
static void wakeup_all_recovery_waiters(void *context)
{
wake_up_all(&_kmirrord_recovery_stopped);
}
static void queue_bio(struct mirror_set *ms, struct bio *bio, int rw)
{
unsigned long flags;
int should_wake = 0;
struct bio_list *bl;
bl = (rw == WRITE) ? &ms->writes : &ms->reads;
spin_lock_irqsave(&ms->lock, flags);
should_wake = !(bl->head);
bio_list_add(bl, bio);
spin_unlock_irqrestore(&ms->lock, flags);
if (should_wake)
wakeup_mirrord(ms);
}
static void dispatch_bios(void *context, struct bio_list *bio_list)
{
struct mirror_set *ms = context;
struct bio *bio;
while ((bio = bio_list_pop(bio_list)))
queue_bio(ms, bio, WRITE);
}
struct dm_raid1_bio_record {
struct mirror *m;
/* if details->bi_bdev == NULL, details were not saved */
struct dm_bio_details details;
region_t write_region;
};
/*
* Every mirror should look like this one.
*/
#define DEFAULT_MIRROR 0
/*
* This is yucky. We squirrel the mirror struct away inside
* bi_next for read/write buffers. This is safe since the bh
* doesn't get submitted to the lower levels of block layer.
*/
static struct mirror *bio_get_m(struct bio *bio)
{
return (struct mirror *) bio->bi_next;
}
static void bio_set_m(struct bio *bio, struct mirror *m)
{
bio->bi_next = (struct bio *) m;
}
static struct mirror *get_default_mirror(struct mirror_set *ms)
{
return &ms->mirror[atomic_read(&ms->default_mirror)];
}
static void set_default_mirror(struct mirror *m)
{
struct mirror_set *ms = m->ms;
struct mirror *m0 = &(ms->mirror[0]);
atomic_set(&ms->default_mirror, m - m0);
}
static struct mirror *get_valid_mirror(struct mirror_set *ms)
{
struct mirror *m;
for (m = ms->mirror; m < ms->mirror + ms->nr_mirrors; m++)
if (!atomic_read(&m->error_count))
return m;
return NULL;
}
/* fail_mirror
* @m: mirror device to fail
* @error_type: one of the enum's, DM_RAID1_*_ERROR
*
* If errors are being handled, record the type of
* error encountered for this device. If this type
* of error has already been recorded, we can return;
* otherwise, we must signal userspace by triggering
* an event. Additionally, if the device is the
* primary device, we must choose a new primary, but
* only if the mirror is in-sync.
*
* This function must not block.
*/
static void fail_mirror(struct mirror *m, enum dm_raid1_error error_type)
{
struct mirror_set *ms = m->ms;
struct mirror *new;
ms->leg_failure = 1;
/*
* error_count is used for nothing more than a
* simple way to tell if a device has encountered
* errors.
*/
atomic_inc(&m->error_count);
if (test_and_set_bit(error_type, &m->error_type))
return;
if (!errors_handled(ms))
return;
if (m != get_default_mirror(ms))
goto out;
if (!ms->in_sync && !keep_log(ms)) {
/*
* Better to issue requests to same failing device
* than to risk returning corrupt data.
*/
DMERR("Primary mirror (%s) failed while out-of-sync: Reads may fail.",
m->dev->name);
goto out;
}
new = get_valid_mirror(ms);
if (new)
set_default_mirror(new);
else
DMWARN("All sides of mirror have failed.");
out:
queue_work(dm_raid1_wq, &ms->trigger_event);
}
static int mirror_flush(struct dm_target *ti)
{
struct mirror_set *ms = ti->private;
unsigned long error_bits;
unsigned int i;
struct dm_io_region io[MAX_NR_MIRRORS];
struct mirror *m;
struct dm_io_request io_req = {
.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC,
.mem.type = DM_IO_KMEM,
.mem.ptr.addr = NULL,
.client = ms->io_client,
};
for (i = 0, m = ms->mirror; i < ms->nr_mirrors; i++, m++) {
io[i].bdev = m->dev->bdev;
io[i].sector = 0;
io[i].count = 0;
}
error_bits = -1;
dm_io(&io_req, ms->nr_mirrors, io, &error_bits);
if (unlikely(error_bits != 0)) {
for (i = 0; i < ms->nr_mirrors; i++)
if (test_bit(i, &error_bits))
fail_mirror(ms->mirror + i,
DM_RAID1_FLUSH_ERROR);
return -EIO;
}
return 0;
}
/*
*---------------------------------------------------------------
* Recovery.
*
* When a mirror is first activated we may find that some regions
* are in the no-sync state. We have to recover these by
* recopying from the default mirror to all the others.
*---------------------------------------------------------------
*/
static void recovery_complete(int read_err, unsigned long write_err,
void *context)
{
struct dm_region *reg = context;
struct mirror_set *ms = dm_rh_region_context(reg);
int m, bit = 0;
if (read_err) {
/* Read error means the failure of default mirror. */
DMERR_LIMIT("Unable to read primary mirror during recovery");
fail_mirror(get_default_mirror(ms), DM_RAID1_SYNC_ERROR);
}
if (write_err) {
DMERR_LIMIT("Write error during recovery (error = 0x%lx)",
write_err);
/*
* Bits correspond to devices (excluding default mirror).
* The default mirror cannot change during recovery.
*/
for (m = 0; m < ms->nr_mirrors; m++) {
if (&ms->mirror[m] == get_default_mirror(ms))
continue;
if (test_bit(bit, &write_err))
fail_mirror(ms->mirror + m,
DM_RAID1_SYNC_ERROR);
bit++;
}
}
dm_rh_recovery_end(reg, !(read_err || write_err));
}
static void recover(struct mirror_set *ms, struct dm_region *reg)
{
unsigned int i;
struct dm_io_region from, to[DM_KCOPYD_MAX_REGIONS], *dest;
struct mirror *m;
unsigned long flags = 0;
region_t key = dm_rh_get_region_key(reg);
sector_t region_size = dm_rh_get_region_size(ms->rh);
/* fill in the source */
m = get_default_mirror(ms);
from.bdev = m->dev->bdev;
from.sector = m->offset + dm_rh_region_to_sector(ms->rh, key);
if (key == (ms->nr_regions - 1)) {
/*
* The final region may be smaller than
* region_size.
*/
from.count = ms->ti->len & (region_size - 1);
if (!from.count)
from.count = region_size;
} else
from.count = region_size;
/* fill in the destinations */
for (i = 0, dest = to; i < ms->nr_mirrors; i++) {
if (&ms->mirror[i] == get_default_mirror(ms))
continue;
m = ms->mirror + i;
dest->bdev = m->dev->bdev;
dest->sector = m->offset + dm_rh_region_to_sector(ms->rh, key);
dest->count = from.count;
dest++;
}
/* hand to kcopyd */
if (!errors_handled(ms))
flags |= BIT(DM_KCOPYD_IGNORE_ERROR);
dm_kcopyd_copy(ms->kcopyd_client, &from, ms->nr_mirrors - 1, to,
flags, recovery_complete, reg);
}
static void reset_ms_flags(struct mirror_set *ms)
{
unsigned int m;
ms->leg_failure = 0;
for (m = 0; m < ms->nr_mirrors; m++) {
atomic_set(&(ms->mirror[m].error_count), 0);
ms->mirror[m].error_type = 0;
}
}
static void do_recovery(struct mirror_set *ms)
{
struct dm_region *reg;
struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
/*
* Start quiescing some regions.
*/
dm_rh_recovery_prepare(ms->rh);
/*
* Copy any already quiesced regions.
*/
while ((reg = dm_rh_recovery_start(ms->rh)))
recover(ms, reg);
/*
* Update the in sync flag.
*/
if (!ms->in_sync &&
(log->type->get_sync_count(log) == ms->nr_regions)) {
/* the sync is complete */
dm_table_event(ms->ti->table);
ms->in_sync = 1;
reset_ms_flags(ms);
}
}
/*
*---------------------------------------------------------------
* Reads
*---------------------------------------------------------------
*/
static struct mirror *choose_mirror(struct mirror_set *ms, sector_t sector)
{
struct mirror *m = get_default_mirror(ms);
do {
if (likely(!atomic_read(&m->error_count)))
return m;
if (m-- == ms->mirror)
m += ms->nr_mirrors;
} while (m != get_default_mirror(ms));
return NULL;
}
static int default_ok(struct mirror *m)
{
struct mirror *default_mirror = get_default_mirror(m->ms);
return !atomic_read(&default_mirror->error_count);
}
static int mirror_available(struct mirror_set *ms, struct bio *bio)
{
struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
region_t region = dm_rh_bio_to_region(ms->rh, bio);
if (log->type->in_sync(log, region, 0))
return choose_mirror(ms, bio->bi_iter.bi_sector) ? 1 : 0;
return 0;
}
/*
* remap a buffer to a particular mirror.
*/
static sector_t map_sector(struct mirror *m, struct bio *bio)
{
if (unlikely(!bio->bi_iter.bi_size))
return 0;
return m->offset + dm_target_offset(m->ms->ti, bio->bi_iter.bi_sector);
}
static void map_bio(struct mirror *m, struct bio *bio)
{
bio_set_dev(bio, m->dev->bdev);
bio->bi_iter.bi_sector = map_sector(m, bio);
}
static void map_region(struct dm_io_region *io, struct mirror *m,
struct bio *bio)
{
io->bdev = m->dev->bdev;
io->sector = map_sector(m, bio);
io->count = bio_sectors(bio);
}
static void hold_bio(struct mirror_set *ms, struct bio *bio)
{
/*
* Lock is required to avoid race condition during suspend
* process.
*/
spin_lock_irq(&ms->lock);
if (atomic_read(&ms->suspend)) {
spin_unlock_irq(&ms->lock);
/*
* If device is suspended, complete the bio.
*/
if (dm_noflush_suspending(ms->ti))
bio->bi_status = BLK_STS_DM_REQUEUE;
else
bio->bi_status = BLK_STS_IOERR;
bio_endio(bio);
return;
}
/*
* Hold bio until the suspend is complete.
*/
bio_list_add(&ms->holds, bio);
spin_unlock_irq(&ms->lock);
}
/*
*---------------------------------------------------------------
* Reads
*---------------------------------------------------------------
*/
static void read_callback(unsigned long error, void *context)
{
struct bio *bio = context;
struct mirror *m;
m = bio_get_m(bio);
bio_set_m(bio, NULL);
if (likely(!error)) {
bio_endio(bio);
return;
}
fail_mirror(m, DM_RAID1_READ_ERROR);
if (likely(default_ok(m)) || mirror_available(m->ms, bio)) {
DMWARN_LIMIT("Read failure on mirror device %s. Trying alternative device.",
m->dev->name);
queue_bio(m->ms, bio, bio_data_dir(bio));
return;
}
DMERR_LIMIT("Read failure on mirror device %s. Failing I/O.",
m->dev->name);
bio_io_error(bio);
}
/* Asynchronous read. */
static void read_async_bio(struct mirror *m, struct bio *bio)
{
struct dm_io_region io;
struct dm_io_request io_req = {
.bi_opf = REQ_OP_READ,
.mem.type = DM_IO_BIO,
.mem.ptr.bio = bio,
.notify.fn = read_callback,
.notify.context = bio,
.client = m->ms->io_client,
};
map_region(&io, m, bio);
bio_set_m(bio, m);
BUG_ON(dm_io(&io_req, 1, &io, NULL));
}
static inline int region_in_sync(struct mirror_set *ms, region_t region,
int may_block)
{
int state = dm_rh_get_state(ms->rh, region, may_block);
return state == DM_RH_CLEAN || state == DM_RH_DIRTY;
}
static void do_reads(struct mirror_set *ms, struct bio_list *reads)
{
region_t region;
struct bio *bio;
struct mirror *m;
while ((bio = bio_list_pop(reads))) {
region = dm_rh_bio_to_region(ms->rh, bio);
m = get_default_mirror(ms);
/*
* We can only read balance if the region is in sync.
*/
if (likely(region_in_sync(ms, region, 1)))
m = choose_mirror(ms, bio->bi_iter.bi_sector);
else if (m && atomic_read(&m->error_count))
m = NULL;
if (likely(m))
read_async_bio(m, bio);
else
bio_io_error(bio);
}
}
/*
*---------------------------------------------------------------------
* Writes.
*
* We do different things with the write io depending on the
* state of the region that it's in:
*
* SYNC: increment pending, use kcopyd to write to *all* mirrors
* RECOVERING: delay the io until recovery completes
* NOSYNC: increment pending, just write to the default mirror
*---------------------------------------------------------------------
*/
static void write_callback(unsigned long error, void *context)
{
unsigned int i;
struct bio *bio = context;
struct mirror_set *ms;
int should_wake = 0;
unsigned long flags;
ms = bio_get_m(bio)->ms;
bio_set_m(bio, NULL);
/*
* NOTE: We don't decrement the pending count here,
* instead it is done by the targets endio function.
* This way we handle both writes to SYNC and NOSYNC
* regions with the same code.
*/
if (likely(!error)) {
bio_endio(bio);
return;
}
/*
* If the bio is discard, return an error, but do not
* degrade the array.
*/
if (bio_op(bio) == REQ_OP_DISCARD) {
bio->bi_status = BLK_STS_NOTSUPP;
bio_endio(bio);
return;
}
for (i = 0; i < ms->nr_mirrors; i++)
if (test_bit(i, &error))
fail_mirror(ms->mirror + i, DM_RAID1_WRITE_ERROR);
/*
* Need to raise event. Since raising
* events can block, we need to do it in
* the main thread.
*/
spin_lock_irqsave(&ms->lock, flags);
if (!ms->failures.head)
should_wake = 1;
bio_list_add(&ms->failures, bio);
spin_unlock_irqrestore(&ms->lock, flags);
if (should_wake)
wakeup_mirrord(ms);
}
static void do_write(struct mirror_set *ms, struct bio *bio)
{
unsigned int i;
struct dm_io_region io[MAX_NR_MIRRORS], *dest = io;
struct mirror *m;
blk_opf_t op_flags = bio->bi_opf & (REQ_FUA | REQ_PREFLUSH);
struct dm_io_request io_req = {
.bi_opf = REQ_OP_WRITE | op_flags,
.mem.type = DM_IO_BIO,
.mem.ptr.bio = bio,
.notify.fn = write_callback,
.notify.context = bio,
.client = ms->io_client,
};
if (bio_op(bio) == REQ_OP_DISCARD) {
io_req.bi_opf = REQ_OP_DISCARD | op_flags;
io_req.mem.type = DM_IO_KMEM;
io_req.mem.ptr.addr = NULL;
}
for (i = 0, m = ms->mirror; i < ms->nr_mirrors; i++, m++)
map_region(dest++, m, bio);
/*
* Use default mirror because we only need it to retrieve the reference
* to the mirror set in write_callback().
*/
bio_set_m(bio, get_default_mirror(ms));
BUG_ON(dm_io(&io_req, ms->nr_mirrors, io, NULL));
}
static void do_writes(struct mirror_set *ms, struct bio_list *writes)
{
int state;
struct bio *bio;
struct bio_list sync, nosync, recover, *this_list = NULL;
struct bio_list requeue;
struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
region_t region;
if (!writes->head)
return;
/*
* Classify each write.
*/
bio_list_init(&sync);
bio_list_init(&nosync);
bio_list_init(&recover);
bio_list_init(&requeue);
while ((bio = bio_list_pop(writes))) {
if ((bio->bi_opf & REQ_PREFLUSH) ||
(bio_op(bio) == REQ_OP_DISCARD)) {
bio_list_add(&sync, bio);
continue;
}
region = dm_rh_bio_to_region(ms->rh, bio);
if (log->type->is_remote_recovering &&
log->type->is_remote_recovering(log, region)) {
bio_list_add(&requeue, bio);
continue;
}
state = dm_rh_get_state(ms->rh, region, 1);
switch (state) {
case DM_RH_CLEAN:
case DM_RH_DIRTY:
this_list = &sync;
break;
case DM_RH_NOSYNC:
this_list = &nosync;
break;
case DM_RH_RECOVERING:
this_list = &recover;
break;
}
bio_list_add(this_list, bio);
}
/*
* Add bios that are delayed due to remote recovery
* back on to the write queue
*/
if (unlikely(requeue.head)) {
spin_lock_irq(&ms->lock);
bio_list_merge(&ms->writes, &requeue);
spin_unlock_irq(&ms->lock);
delayed_wake(ms);
}
/*
* Increment the pending counts for any regions that will
* be written to (writes to recover regions are going to
* be delayed).
*/
dm_rh_inc_pending(ms->rh, &sync);
dm_rh_inc_pending(ms->rh, &nosync);
/*
* If the flush fails on a previous call and succeeds here,
* we must not reset the log_failure variable. We need
* userspace interaction to do that.
*/
ms->log_failure = dm_rh_flush(ms->rh) ? 1 : ms->log_failure;
/*
* Dispatch io.
*/
if (unlikely(ms->log_failure) && errors_handled(ms)) {
spin_lock_irq(&ms->lock);
bio_list_merge(&ms->failures, &sync);
spin_unlock_irq(&ms->lock);
wakeup_mirrord(ms);
} else
while ((bio = bio_list_pop(&sync)))
do_write(ms, bio);
while ((bio = bio_list_pop(&recover)))
dm_rh_delay(ms->rh, bio);
while ((bio = bio_list_pop(&nosync))) {
if (unlikely(ms->leg_failure) && errors_handled(ms) && !keep_log(ms)) {
spin_lock_irq(&ms->lock);
bio_list_add(&ms->failures, bio);
spin_unlock_irq(&ms->lock);
wakeup_mirrord(ms);
} else {
map_bio(get_default_mirror(ms), bio);
submit_bio_noacct(bio);
}
}
}
static void do_failures(struct mirror_set *ms, struct bio_list *failures)
{
struct bio *bio;
if (likely(!failures->head))
return;
/*
* If the log has failed, unattempted writes are being
* put on the holds list. We can't issue those writes
* until a log has been marked, so we must store them.
*
* If a 'noflush' suspend is in progress, we can requeue
* the I/O's to the core. This give userspace a chance
* to reconfigure the mirror, at which point the core
* will reissue the writes. If the 'noflush' flag is
* not set, we have no choice but to return errors.
*
* Some writes on the failures list may have been
* submitted before the log failure and represent a
* failure to write to one of the devices. It is ok
* for us to treat them the same and requeue them
* as well.
*/
while ((bio = bio_list_pop(failures))) {
if (!ms->log_failure) {
ms->in_sync = 0;
dm_rh_mark_nosync(ms->rh, bio);
}
/*
* If all the legs are dead, fail the I/O.
* If the device has failed and keep_log is enabled,
* fail the I/O.
*
* If we have been told to handle errors, and keep_log
* isn't enabled, hold the bio and wait for userspace to
* deal with the problem.
*
* Otherwise pretend that the I/O succeeded. (This would
* be wrong if the failed leg returned after reboot and
* got replicated back to the good legs.)
*/
if (unlikely(!get_valid_mirror(ms) || (keep_log(ms) && ms->log_failure)))
bio_io_error(bio);
else if (errors_handled(ms) && !keep_log(ms))
hold_bio(ms, bio);
else
bio_endio(bio);
}
}
static void trigger_event(struct work_struct *work)
{
struct mirror_set *ms =
container_of(work, struct mirror_set, trigger_event);
dm_table_event(ms->ti->table);
}
/*
*---------------------------------------------------------------
* kmirrord
*---------------------------------------------------------------
*/
static void do_mirror(struct work_struct *work)
{
struct mirror_set *ms = container_of(work, struct mirror_set,
kmirrord_work);
struct bio_list reads, writes, failures;
unsigned long flags;
spin_lock_irqsave(&ms->lock, flags);
reads = ms->reads;
writes = ms->writes;
failures = ms->failures;
bio_list_init(&ms->reads);
bio_list_init(&ms->writes);
bio_list_init(&ms->failures);
spin_unlock_irqrestore(&ms->lock, flags);
dm_rh_update_states(ms->rh, errors_handled(ms));
do_recovery(ms);
do_reads(ms, &reads);
do_writes(ms, &writes);
do_failures(ms, &failures);
}
/*
*---------------------------------------------------------------
* Target functions
*---------------------------------------------------------------
*/
static struct mirror_set *alloc_context(unsigned int nr_mirrors,
uint32_t region_size,
struct dm_target *ti,
struct dm_dirty_log *dl)
{
struct mirror_set *ms =
kzalloc(struct_size(ms, mirror, nr_mirrors), GFP_KERNEL);
if (!ms) {
ti->error = "Cannot allocate mirror context";
return NULL;
}
spin_lock_init(&ms->lock);
bio_list_init(&ms->reads);
bio_list_init(&ms->writes);
bio_list_init(&ms->failures);
bio_list_init(&ms->holds);
ms->ti = ti;
ms->nr_mirrors = nr_mirrors;
ms->nr_regions = dm_sector_div_up(ti->len, region_size);
ms->in_sync = 0;
ms->log_failure = 0;
ms->leg_failure = 0;
atomic_set(&ms->suspend, 0);
atomic_set(&ms->default_mirror, DEFAULT_MIRROR);
ms->io_client = dm_io_client_create();
if (IS_ERR(ms->io_client)) {
ti->error = "Error creating dm_io client";
kfree(ms);
return NULL;
}
ms->rh = dm_region_hash_create(ms, dispatch_bios, wakeup_mirrord,
wakeup_all_recovery_waiters,
ms->ti->begin, MAX_RECOVERY,
dl, region_size, ms->nr_regions);
if (IS_ERR(ms->rh)) {
ti->error = "Error creating dirty region hash";
dm_io_client_destroy(ms->io_client);
kfree(ms);
return NULL;
}
return ms;
}
static void free_context(struct mirror_set *ms, struct dm_target *ti,
unsigned int m)
{
while (m--)
dm_put_device(ti, ms->mirror[m].dev);
dm_io_client_destroy(ms->io_client);
dm_region_hash_destroy(ms->rh);
kfree(ms);
}
static int get_mirror(struct mirror_set *ms, struct dm_target *ti,
unsigned int mirror, char **argv)
{
unsigned long long offset;
char dummy;
int ret;
if (sscanf(argv[1], "%llu%c", &offset, &dummy) != 1 ||
offset != (sector_t)offset) {
ti->error = "Invalid offset";
return -EINVAL;
}
ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
&ms->mirror[mirror].dev);
if (ret) {
ti->error = "Device lookup failure";
return ret;
}
ms->mirror[mirror].ms = ms;
atomic_set(&(ms->mirror[mirror].error_count), 0);
ms->mirror[mirror].error_type = 0;
ms->mirror[mirror].offset = offset;
return 0;
}
/*
* Create dirty log: log_type #log_params <log_params>
*/
static struct dm_dirty_log *create_dirty_log(struct dm_target *ti,
unsigned int argc, char **argv,
unsigned int *args_used)
{
unsigned int param_count;
struct dm_dirty_log *dl;
char dummy;
if (argc < 2) {
ti->error = "Insufficient mirror log arguments";
return NULL;
}
if (sscanf(argv[1], "%u%c", ¶m_count, &dummy) != 1) {
ti->error = "Invalid mirror log argument count";
return NULL;
}
*args_used = 2 + param_count;
if (argc < *args_used) {
ti->error = "Insufficient mirror log arguments";
return NULL;
}
dl = dm_dirty_log_create(argv[0], ti, mirror_flush, param_count,
argv + 2);
if (!dl) {
ti->error = "Error creating mirror dirty log";
return NULL;
}
return dl;
}
static int parse_features(struct mirror_set *ms, unsigned int argc, char **argv,
unsigned int *args_used)
{
unsigned int num_features;
struct dm_target *ti = ms->ti;
char dummy;
int i;
*args_used = 0;
if (!argc)
return 0;
if (sscanf(argv[0], "%u%c", &num_features, &dummy) != 1) {
ti->error = "Invalid number of features";
return -EINVAL;
}
argc--;
argv++;
(*args_used)++;
if (num_features > argc) {
ti->error = "Not enough arguments to support feature count";
return -EINVAL;
}
for (i = 0; i < num_features; i++) {
if (!strcmp("handle_errors", argv[0]))
ms->features |= DM_RAID1_HANDLE_ERRORS;
else if (!strcmp("keep_log", argv[0]))
ms->features |= DM_RAID1_KEEP_LOG;
else {
ti->error = "Unrecognised feature requested";
return -EINVAL;
}
argc--;
argv++;
(*args_used)++;
}
if (!errors_handled(ms) && keep_log(ms)) {
ti->error = "keep_log feature requires the handle_errors feature";
return -EINVAL;
}
return 0;
}
/*
* Construct a mirror mapping:
*
* log_type #log_params <log_params>
* #mirrors [mirror_path offset]{2,}
* [#features <features>]
*
* log_type is "core" or "disk"
* #log_params is between 1 and 3
*
* If present, supported features are "handle_errors" and "keep_log".
*/
static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
int r;
unsigned int nr_mirrors, m, args_used;
struct mirror_set *ms;
struct dm_dirty_log *dl;
char dummy;
dl = create_dirty_log(ti, argc, argv, &args_used);
if (!dl)
return -EINVAL;
argv += args_used;
argc -= args_used;
if (!argc || sscanf(argv[0], "%u%c", &nr_mirrors, &dummy) != 1 ||
nr_mirrors < 2 || nr_mirrors > MAX_NR_MIRRORS) {
ti->error = "Invalid number of mirrors";
dm_dirty_log_destroy(dl);
return -EINVAL;
}
argv++, argc--;
if (argc < nr_mirrors * 2) {
ti->error = "Too few mirror arguments";
dm_dirty_log_destroy(dl);
return -EINVAL;
}
ms = alloc_context(nr_mirrors, dl->type->get_region_size(dl), ti, dl);
if (!ms) {
dm_dirty_log_destroy(dl);
return -ENOMEM;
}
/* Get the mirror parameter sets */
for (m = 0; m < nr_mirrors; m++) {
r = get_mirror(ms, ti, m, argv);
if (r) {
free_context(ms, ti, m);
return r;
}
argv += 2;
argc -= 2;
}
ti->private = ms;
r = dm_set_target_max_io_len(ti, dm_rh_get_region_size(ms->rh));
if (r)
goto err_free_context;
ti->num_flush_bios = 1;
ti->num_discard_bios = 1;
ti->per_io_data_size = sizeof(struct dm_raid1_bio_record);
ms->kmirrord_wq = alloc_workqueue("kmirrord", WQ_MEM_RECLAIM, 0);
if (!ms->kmirrord_wq) {
DMERR("couldn't start kmirrord");
r = -ENOMEM;
goto err_free_context;
}
INIT_WORK(&ms->kmirrord_work, do_mirror);
timer_setup(&ms->timer, delayed_wake_fn, 0);
ms->timer_pending = 0;
INIT_WORK(&ms->trigger_event, trigger_event);
r = parse_features(ms, argc, argv, &args_used);
if (r)
goto err_destroy_wq;
argv += args_used;
argc -= args_used;
/*
* Any read-balancing addition depends on the
* DM_RAID1_HANDLE_ERRORS flag being present.
* This is because the decision to balance depends
* on the sync state of a region. If the above
* flag is not present, we ignore errors; and
* the sync state may be inaccurate.
*/
if (argc) {
ti->error = "Too many mirror arguments";
r = -EINVAL;
goto err_destroy_wq;
}
ms->kcopyd_client = dm_kcopyd_client_create(&dm_kcopyd_throttle);
if (IS_ERR(ms->kcopyd_client)) {
r = PTR_ERR(ms->kcopyd_client);
goto err_destroy_wq;
}
wakeup_mirrord(ms);
return 0;
err_destroy_wq:
destroy_workqueue(ms->kmirrord_wq);
err_free_context:
free_context(ms, ti, ms->nr_mirrors);
return r;
}
static void mirror_dtr(struct dm_target *ti)
{
struct mirror_set *ms = ti->private;
del_timer_sync(&ms->timer);
flush_workqueue(ms->kmirrord_wq);
flush_work(&ms->trigger_event);
dm_kcopyd_client_destroy(ms->kcopyd_client);
destroy_workqueue(ms->kmirrord_wq);
free_context(ms, ti, ms->nr_mirrors);
}
/*
* Mirror mapping function
*/
static int mirror_map(struct dm_target *ti, struct bio *bio)
{
int r, rw = bio_data_dir(bio);
struct mirror *m;
struct mirror_set *ms = ti->private;
struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
struct dm_raid1_bio_record *bio_record =
dm_per_bio_data(bio, sizeof(struct dm_raid1_bio_record));
bio_record->details.bi_bdev = NULL;
if (rw == WRITE) {
/* Save region for mirror_end_io() handler */
bio_record->write_region = dm_rh_bio_to_region(ms->rh, bio);
queue_bio(ms, bio, rw);
return DM_MAPIO_SUBMITTED;
}
r = log->type->in_sync(log, dm_rh_bio_to_region(ms->rh, bio), 0);
if (r < 0 && r != -EWOULDBLOCK)
return DM_MAPIO_KILL;
/*
* If region is not in-sync queue the bio.
*/
if (!r || (r == -EWOULDBLOCK)) {
if (bio->bi_opf & REQ_RAHEAD)
return DM_MAPIO_KILL;
queue_bio(ms, bio, rw);
return DM_MAPIO_SUBMITTED;
}
/*
* The region is in-sync and we can perform reads directly.
* Store enough information so we can retry if it fails.
*/
m = choose_mirror(ms, bio->bi_iter.bi_sector);
if (unlikely(!m))
return DM_MAPIO_KILL;
dm_bio_record(&bio_record->details, bio);
bio_record->m = m;
map_bio(m, bio);
return DM_MAPIO_REMAPPED;
}
static int mirror_end_io(struct dm_target *ti, struct bio *bio,
blk_status_t *error)
{
int rw = bio_data_dir(bio);
struct mirror_set *ms = ti->private;
struct mirror *m = NULL;
struct dm_bio_details *bd = NULL;
struct dm_raid1_bio_record *bio_record =
dm_per_bio_data(bio, sizeof(struct dm_raid1_bio_record));
/*
* We need to dec pending if this was a write.
*/
if (rw == WRITE) {
if (!(bio->bi_opf & REQ_PREFLUSH) &&
bio_op(bio) != REQ_OP_DISCARD)
dm_rh_dec(ms->rh, bio_record->write_region);
return DM_ENDIO_DONE;
}
if (*error == BLK_STS_NOTSUPP)
goto out;
if (bio->bi_opf & REQ_RAHEAD)
goto out;
if (unlikely(*error)) {
if (!bio_record->details.bi_bdev) {
/*
* There wasn't enough memory to record necessary
* information for a retry or there was no other
* mirror in-sync.
*/
DMERR_LIMIT("Mirror read failed.");
return DM_ENDIO_DONE;
}
m = bio_record->m;
DMERR("Mirror read failed from %s. Trying alternative device.",
m->dev->name);
fail_mirror(m, DM_RAID1_READ_ERROR);
/*
* A failed read is requeued for another attempt using an intact
* mirror.
*/
if (default_ok(m) || mirror_available(ms, bio)) {
bd = &bio_record->details;
dm_bio_restore(bd, bio);
bio_record->details.bi_bdev = NULL;
bio->bi_status = 0;
queue_bio(ms, bio, rw);
return DM_ENDIO_INCOMPLETE;
}
DMERR("All replicated volumes dead, failing I/O");
}
out:
bio_record->details.bi_bdev = NULL;
return DM_ENDIO_DONE;
}
static void mirror_presuspend(struct dm_target *ti)
{
struct mirror_set *ms = ti->private;
struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
struct bio_list holds;
struct bio *bio;
atomic_set(&ms->suspend, 1);
/*
* Process bios in the hold list to start recovery waiting
* for bios in the hold list. After the process, no bio has
* a chance to be added in the hold list because ms->suspend
* is set.
*/
spin_lock_irq(&ms->lock);
holds = ms->holds;
bio_list_init(&ms->holds);
spin_unlock_irq(&ms->lock);
while ((bio = bio_list_pop(&holds)))
hold_bio(ms, bio);
/*
* We must finish up all the work that we've
* generated (i.e. recovery work).
*/
dm_rh_stop_recovery(ms->rh);
wait_event(_kmirrord_recovery_stopped,
!dm_rh_recovery_in_flight(ms->rh));
if (log->type->presuspend && log->type->presuspend(log))
/* FIXME: need better error handling */
DMWARN("log presuspend failed");
/*
* Now that recovery is complete/stopped and the
* delayed bios are queued, we need to wait for
* the worker thread to complete. This way,
* we know that all of our I/O has been pushed.
*/
flush_workqueue(ms->kmirrord_wq);
}
static void mirror_postsuspend(struct dm_target *ti)
{
struct mirror_set *ms = ti->private;
struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
if (log->type->postsuspend && log->type->postsuspend(log))
/* FIXME: need better error handling */
DMWARN("log postsuspend failed");
}
static void mirror_resume(struct dm_target *ti)
{
struct mirror_set *ms = ti->private;
struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
atomic_set(&ms->suspend, 0);
if (log->type->resume && log->type->resume(log))
/* FIXME: need better error handling */
DMWARN("log resume failed");
dm_rh_start_recovery(ms->rh);
}
/*
* device_status_char
* @m: mirror device/leg we want the status of
*
* We return one character representing the most severe error
* we have encountered.
* A => Alive - No failures
* D => Dead - A write failure occurred leaving mirror out-of-sync
* S => Sync - A sychronization failure occurred, mirror out-of-sync
* R => Read - A read failure occurred, mirror data unaffected
*
* Returns: <char>
*/
static char device_status_char(struct mirror *m)
{
if (!atomic_read(&(m->error_count)))
return 'A';
return (test_bit(DM_RAID1_FLUSH_ERROR, &(m->error_type))) ? 'F' :
(test_bit(DM_RAID1_WRITE_ERROR, &(m->error_type))) ? 'D' :
(test_bit(DM_RAID1_SYNC_ERROR, &(m->error_type))) ? 'S' :
(test_bit(DM_RAID1_READ_ERROR, &(m->error_type))) ? 'R' : 'U';
}
static void mirror_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
unsigned int m, sz = 0;
int num_feature_args = 0;
struct mirror_set *ms = ti->private;
struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
char buffer[MAX_NR_MIRRORS + 1];
switch (type) {
case STATUSTYPE_INFO:
DMEMIT("%d ", ms->nr_mirrors);
for (m = 0; m < ms->nr_mirrors; m++) {
DMEMIT("%s ", ms->mirror[m].dev->name);
buffer[m] = device_status_char(&(ms->mirror[m]));
}
buffer[m] = '\0';
DMEMIT("%llu/%llu 1 %s ",
(unsigned long long)log->type->get_sync_count(log),
(unsigned long long)ms->nr_regions, buffer);
sz += log->type->status(log, type, result+sz, maxlen-sz);
break;
case STATUSTYPE_TABLE:
sz = log->type->status(log, type, result, maxlen);
DMEMIT("%d", ms->nr_mirrors);
for (m = 0; m < ms->nr_mirrors; m++)
DMEMIT(" %s %llu", ms->mirror[m].dev->name,
(unsigned long long)ms->mirror[m].offset);
num_feature_args += !!errors_handled(ms);
num_feature_args += !!keep_log(ms);
if (num_feature_args) {
DMEMIT(" %d", num_feature_args);
if (errors_handled(ms))
DMEMIT(" handle_errors");
if (keep_log(ms))
DMEMIT(" keep_log");
}
break;
case STATUSTYPE_IMA:
DMEMIT_TARGET_NAME_VERSION(ti->type);
DMEMIT(",nr_mirrors=%d", ms->nr_mirrors);
for (m = 0; m < ms->nr_mirrors; m++) {
DMEMIT(",mirror_device_%d=%s", m, ms->mirror[m].dev->name);
DMEMIT(",mirror_device_%d_status=%c",
m, device_status_char(&(ms->mirror[m])));
}
DMEMIT(",handle_errors=%c", errors_handled(ms) ? 'y' : 'n');
DMEMIT(",keep_log=%c", keep_log(ms) ? 'y' : 'n');
DMEMIT(",log_type_status=");
sz += log->type->status(log, type, result+sz, maxlen-sz);
DMEMIT(";");
break;
}
}
static int mirror_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct mirror_set *ms = ti->private;
int ret = 0;
unsigned int i;
for (i = 0; !ret && i < ms->nr_mirrors; i++)
ret = fn(ti, ms->mirror[i].dev,
ms->mirror[i].offset, ti->len, data);
return ret;
}
static struct target_type mirror_target = {
.name = "mirror",
.version = {1, 14, 0},
.module = THIS_MODULE,
.ctr = mirror_ctr,
.dtr = mirror_dtr,
.map = mirror_map,
.end_io = mirror_end_io,
.presuspend = mirror_presuspend,
.postsuspend = mirror_postsuspend,
.resume = mirror_resume,
.status = mirror_status,
.iterate_devices = mirror_iterate_devices,
};
static int __init dm_mirror_init(void)
{
int r;
dm_raid1_wq = alloc_workqueue("dm_raid1_wq", 0, 0);
if (!dm_raid1_wq) {
DMERR("Failed to alloc workqueue");
return -ENOMEM;
}
r = dm_register_target(&mirror_target);
if (r < 0) {
destroy_workqueue(dm_raid1_wq);
return r;
}
return 0;
}
static void __exit dm_mirror_exit(void)
{
destroy_workqueue(dm_raid1_wq);
dm_unregister_target(&mirror_target);
}
/* Module hooks */
module_init(dm_mirror_init);
module_exit(dm_mirror_exit);
MODULE_DESCRIPTION(DM_NAME " mirror target");
MODULE_AUTHOR("Joe Thornber");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-raid1.c |
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* multipath.c : Multiple Devices driver for Linux
*
* Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
*
* Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
*
* MULTIPATH management functions.
*
* derived from raid1.c.
*/
#include <linux/blkdev.h>
#include <linux/module.h>
#include <linux/raid/md_u.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include "md.h"
#include "md-multipath.h"
#define MAX_WORK_PER_DISK 128
#define NR_RESERVED_BUFS 32
static int multipath_map (struct mpconf *conf)
{
int i, disks = conf->raid_disks;
/*
* Later we do read balancing on the read side
* now we use the first available disk.
*/
rcu_read_lock();
for (i = 0; i < disks; i++) {
struct md_rdev *rdev = rcu_dereference(conf->multipaths[i].rdev);
if (rdev && test_bit(In_sync, &rdev->flags) &&
!test_bit(Faulty, &rdev->flags)) {
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
return i;
}
}
rcu_read_unlock();
pr_crit_ratelimited("multipath_map(): no more operational IO paths?\n");
return (-1);
}
static void multipath_reschedule_retry (struct multipath_bh *mp_bh)
{
unsigned long flags;
struct mddev *mddev = mp_bh->mddev;
struct mpconf *conf = mddev->private;
spin_lock_irqsave(&conf->device_lock, flags);
list_add(&mp_bh->retry_list, &conf->retry_list);
spin_unlock_irqrestore(&conf->device_lock, flags);
md_wakeup_thread(mddev->thread);
}
/*
* multipath_end_bh_io() is called when we have finished servicing a multipathed
* operation and are ready to return a success/failure code to the buffer
* cache layer.
*/
static void multipath_end_bh_io(struct multipath_bh *mp_bh, blk_status_t status)
{
struct bio *bio = mp_bh->master_bio;
struct mpconf *conf = mp_bh->mddev->private;
bio->bi_status = status;
bio_endio(bio);
mempool_free(mp_bh, &conf->pool);
}
static void multipath_end_request(struct bio *bio)
{
struct multipath_bh *mp_bh = bio->bi_private;
struct mpconf *conf = mp_bh->mddev->private;
struct md_rdev *rdev = conf->multipaths[mp_bh->path].rdev;
if (!bio->bi_status)
multipath_end_bh_io(mp_bh, 0);
else if (!(bio->bi_opf & REQ_RAHEAD)) {
/*
* oops, IO error:
*/
md_error (mp_bh->mddev, rdev);
pr_info("multipath: %pg: rescheduling sector %llu\n",
rdev->bdev,
(unsigned long long)bio->bi_iter.bi_sector);
multipath_reschedule_retry(mp_bh);
} else
multipath_end_bh_io(mp_bh, bio->bi_status);
rdev_dec_pending(rdev, conf->mddev);
}
static bool multipath_make_request(struct mddev *mddev, struct bio * bio)
{
struct mpconf *conf = mddev->private;
struct multipath_bh * mp_bh;
struct multipath_info *multipath;
if (unlikely(bio->bi_opf & REQ_PREFLUSH)
&& md_flush_request(mddev, bio))
return true;
md_account_bio(mddev, &bio);
mp_bh = mempool_alloc(&conf->pool, GFP_NOIO);
mp_bh->master_bio = bio;
mp_bh->mddev = mddev;
mp_bh->path = multipath_map(conf);
if (mp_bh->path < 0) {
bio_io_error(bio);
mempool_free(mp_bh, &conf->pool);
return true;
}
multipath = conf->multipaths + mp_bh->path;
bio_init_clone(multipath->rdev->bdev, &mp_bh->bio, bio, GFP_NOIO);
mp_bh->bio.bi_iter.bi_sector += multipath->rdev->data_offset;
mp_bh->bio.bi_opf |= REQ_FAILFAST_TRANSPORT;
mp_bh->bio.bi_end_io = multipath_end_request;
mp_bh->bio.bi_private = mp_bh;
mddev_check_write_zeroes(mddev, &mp_bh->bio);
submit_bio_noacct(&mp_bh->bio);
return true;
}
static void multipath_status(struct seq_file *seq, struct mddev *mddev)
{
struct mpconf *conf = mddev->private;
int i;
seq_printf (seq, " [%d/%d] [", conf->raid_disks,
conf->raid_disks - mddev->degraded);
rcu_read_lock();
for (i = 0; i < conf->raid_disks; i++) {
struct md_rdev *rdev = rcu_dereference(conf->multipaths[i].rdev);
seq_printf (seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
}
rcu_read_unlock();
seq_putc(seq, ']');
}
/*
* Careful, this can execute in IRQ contexts as well!
*/
static void multipath_error (struct mddev *mddev, struct md_rdev *rdev)
{
struct mpconf *conf = mddev->private;
if (conf->raid_disks - mddev->degraded <= 1) {
/*
* Uh oh, we can do nothing if this is our last path, but
* first check if this is a queued request for a device
* which has just failed.
*/
pr_warn("multipath: only one IO path left and IO error.\n");
/* leave it active... it's all we have */
return;
}
/*
* Mark disk as unusable
*/
if (test_and_clear_bit(In_sync, &rdev->flags)) {
unsigned long flags;
spin_lock_irqsave(&conf->device_lock, flags);
mddev->degraded++;
spin_unlock_irqrestore(&conf->device_lock, flags);
}
set_bit(Faulty, &rdev->flags);
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
pr_err("multipath: IO failure on %pg, disabling IO path.\n"
"multipath: Operation continuing on %d IO paths.\n",
rdev->bdev,
conf->raid_disks - mddev->degraded);
}
static void print_multipath_conf (struct mpconf *conf)
{
int i;
struct multipath_info *tmp;
pr_debug("MULTIPATH conf printout:\n");
if (!conf) {
pr_debug("(conf==NULL)\n");
return;
}
pr_debug(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
conf->raid_disks);
for (i = 0; i < conf->raid_disks; i++) {
tmp = conf->multipaths + i;
if (tmp->rdev)
pr_debug(" disk%d, o:%d, dev:%pg\n",
i,!test_bit(Faulty, &tmp->rdev->flags),
tmp->rdev->bdev);
}
}
static int multipath_add_disk(struct mddev *mddev, struct md_rdev *rdev)
{
struct mpconf *conf = mddev->private;
int err = -EEXIST;
int path;
struct multipath_info *p;
int first = 0;
int last = mddev->raid_disks - 1;
if (rdev->raid_disk >= 0)
first = last = rdev->raid_disk;
print_multipath_conf(conf);
for (path = first; path <= last; path++)
if ((p=conf->multipaths+path)->rdev == NULL) {
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
err = md_integrity_add_rdev(rdev, mddev);
if (err)
break;
spin_lock_irq(&conf->device_lock);
mddev->degraded--;
rdev->raid_disk = path;
set_bit(In_sync, &rdev->flags);
spin_unlock_irq(&conf->device_lock);
rcu_assign_pointer(p->rdev, rdev);
err = 0;
break;
}
print_multipath_conf(conf);
return err;
}
static int multipath_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
{
struct mpconf *conf = mddev->private;
int err = 0;
int number = rdev->raid_disk;
struct multipath_info *p = conf->multipaths + number;
print_multipath_conf(conf);
if (rdev == p->rdev) {
if (test_bit(In_sync, &rdev->flags) ||
atomic_read(&rdev->nr_pending)) {
pr_warn("hot-remove-disk, slot %d is identified but is still operational!\n", number);
err = -EBUSY;
goto abort;
}
p->rdev = NULL;
if (!test_bit(RemoveSynchronized, &rdev->flags)) {
synchronize_rcu();
if (atomic_read(&rdev->nr_pending)) {
/* lost the race, try later */
err = -EBUSY;
p->rdev = rdev;
goto abort;
}
}
err = md_integrity_register(mddev);
}
abort:
print_multipath_conf(conf);
return err;
}
/*
* This is a kernel thread which:
*
* 1. Retries failed read operations on working multipaths.
* 2. Updates the raid superblock when problems encounter.
* 3. Performs writes following reads for array syncronising.
*/
static void multipathd(struct md_thread *thread)
{
struct mddev *mddev = thread->mddev;
struct multipath_bh *mp_bh;
struct bio *bio;
unsigned long flags;
struct mpconf *conf = mddev->private;
struct list_head *head = &conf->retry_list;
md_check_recovery(mddev);
for (;;) {
spin_lock_irqsave(&conf->device_lock, flags);
if (list_empty(head))
break;
mp_bh = list_entry(head->prev, struct multipath_bh, retry_list);
list_del(head->prev);
spin_unlock_irqrestore(&conf->device_lock, flags);
bio = &mp_bh->bio;
bio->bi_iter.bi_sector = mp_bh->master_bio->bi_iter.bi_sector;
if ((mp_bh->path = multipath_map (conf))<0) {
pr_err("multipath: %pg: unrecoverable IO read error for block %llu\n",
bio->bi_bdev,
(unsigned long long)bio->bi_iter.bi_sector);
multipath_end_bh_io(mp_bh, BLK_STS_IOERR);
} else {
pr_err("multipath: %pg: redirecting sector %llu to another IO path\n",
bio->bi_bdev,
(unsigned long long)bio->bi_iter.bi_sector);
*bio = *(mp_bh->master_bio);
bio->bi_iter.bi_sector +=
conf->multipaths[mp_bh->path].rdev->data_offset;
bio_set_dev(bio, conf->multipaths[mp_bh->path].rdev->bdev);
bio->bi_opf |= REQ_FAILFAST_TRANSPORT;
bio->bi_end_io = multipath_end_request;
bio->bi_private = mp_bh;
submit_bio_noacct(bio);
}
}
spin_unlock_irqrestore(&conf->device_lock, flags);
}
static sector_t multipath_size(struct mddev *mddev, sector_t sectors, int raid_disks)
{
WARN_ONCE(sectors || raid_disks,
"%s does not support generic reshape\n", __func__);
return mddev->dev_sectors;
}
static int multipath_run (struct mddev *mddev)
{
struct mpconf *conf;
int disk_idx;
struct multipath_info *disk;
struct md_rdev *rdev;
int working_disks;
int ret;
if (md_check_no_bitmap(mddev))
return -EINVAL;
if (mddev->level != LEVEL_MULTIPATH) {
pr_warn("multipath: %s: raid level not set to multipath IO (%d)\n",
mdname(mddev), mddev->level);
goto out;
}
/*
* copy the already verified devices into our private MULTIPATH
* bookkeeping area. [whatever we allocate in multipath_run(),
* should be freed in multipath_free()]
*/
conf = kzalloc(sizeof(struct mpconf), GFP_KERNEL);
mddev->private = conf;
if (!conf)
goto out;
conf->multipaths = kcalloc(mddev->raid_disks,
sizeof(struct multipath_info),
GFP_KERNEL);
if (!conf->multipaths)
goto out_free_conf;
working_disks = 0;
rdev_for_each(rdev, mddev) {
disk_idx = rdev->raid_disk;
if (disk_idx < 0 ||
disk_idx >= mddev->raid_disks)
continue;
disk = conf->multipaths + disk_idx;
disk->rdev = rdev;
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
if (!test_bit(Faulty, &rdev->flags))
working_disks++;
}
conf->raid_disks = mddev->raid_disks;
conf->mddev = mddev;
spin_lock_init(&conf->device_lock);
INIT_LIST_HEAD(&conf->retry_list);
if (!working_disks) {
pr_warn("multipath: no operational IO paths for %s\n",
mdname(mddev));
goto out_free_conf;
}
mddev->degraded = conf->raid_disks - working_disks;
ret = mempool_init_kmalloc_pool(&conf->pool, NR_RESERVED_BUFS,
sizeof(struct multipath_bh));
if (ret)
goto out_free_conf;
rcu_assign_pointer(mddev->thread,
md_register_thread(multipathd, mddev, "multipath"));
if (!mddev->thread)
goto out_free_conf;
pr_info("multipath: array %s active with %d out of %d IO paths\n",
mdname(mddev), conf->raid_disks - mddev->degraded,
mddev->raid_disks);
/*
* Ok, everything is just fine now
*/
md_set_array_sectors(mddev, multipath_size(mddev, 0, 0));
if (md_integrity_register(mddev))
goto out_free_conf;
return 0;
out_free_conf:
mempool_exit(&conf->pool);
kfree(conf->multipaths);
kfree(conf);
mddev->private = NULL;
out:
return -EIO;
}
static void multipath_free(struct mddev *mddev, void *priv)
{
struct mpconf *conf = priv;
mempool_exit(&conf->pool);
kfree(conf->multipaths);
kfree(conf);
}
static struct md_personality multipath_personality =
{
.name = "multipath",
.level = LEVEL_MULTIPATH,
.owner = THIS_MODULE,
.make_request = multipath_make_request,
.run = multipath_run,
.free = multipath_free,
.status = multipath_status,
.error_handler = multipath_error,
.hot_add_disk = multipath_add_disk,
.hot_remove_disk= multipath_remove_disk,
.size = multipath_size,
};
static int __init multipath_init (void)
{
return register_md_personality (&multipath_personality);
}
static void __exit multipath_exit (void)
{
unregister_md_personality (&multipath_personality);
}
module_init(multipath_init);
module_exit(multipath_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("simple multi-path personality for MD (deprecated)");
MODULE_ALIAS("md-personality-7"); /* MULTIPATH */
MODULE_ALIAS("md-multipath");
MODULE_ALIAS("md-level--4");
| linux-master | drivers/md/md-multipath.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2015 Red Hat. All rights reserved.
*
* This file is released under the GPL.
*/
#include "dm-cache-background-tracker.h"
#include "dm-cache-policy-internal.h"
#include "dm-cache-policy.h"
#include "dm.h"
#include <linux/hash.h>
#include <linux/jiffies.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/vmalloc.h>
#include <linux/math64.h>
#define DM_MSG_PREFIX "cache-policy-smq"
/*----------------------------------------------------------------*/
/*
* Safe division functions that return zero on divide by zero.
*/
static unsigned int safe_div(unsigned int n, unsigned int d)
{
return d ? n / d : 0u;
}
static unsigned int safe_mod(unsigned int n, unsigned int d)
{
return d ? n % d : 0u;
}
/*----------------------------------------------------------------*/
struct entry {
unsigned int hash_next:28;
unsigned int prev:28;
unsigned int next:28;
unsigned int level:6;
bool dirty:1;
bool allocated:1;
bool sentinel:1;
bool pending_work:1;
dm_oblock_t oblock;
};
/*----------------------------------------------------------------*/
#define INDEXER_NULL ((1u << 28u) - 1u)
/*
* An entry_space manages a set of entries that we use for the queues.
* The clean and dirty queues share entries, so this object is separate
* from the queue itself.
*/
struct entry_space {
struct entry *begin;
struct entry *end;
};
static int space_init(struct entry_space *es, unsigned int nr_entries)
{
if (!nr_entries) {
es->begin = es->end = NULL;
return 0;
}
es->begin = vzalloc(array_size(nr_entries, sizeof(struct entry)));
if (!es->begin)
return -ENOMEM;
es->end = es->begin + nr_entries;
return 0;
}
static void space_exit(struct entry_space *es)
{
vfree(es->begin);
}
static struct entry *__get_entry(struct entry_space *es, unsigned int block)
{
struct entry *e;
e = es->begin + block;
BUG_ON(e >= es->end);
return e;
}
static unsigned int to_index(struct entry_space *es, struct entry *e)
{
BUG_ON(e < es->begin || e >= es->end);
return e - es->begin;
}
static struct entry *to_entry(struct entry_space *es, unsigned int block)
{
if (block == INDEXER_NULL)
return NULL;
return __get_entry(es, block);
}
/*----------------------------------------------------------------*/
struct ilist {
unsigned int nr_elts; /* excluding sentinel entries */
unsigned int head, tail;
};
static void l_init(struct ilist *l)
{
l->nr_elts = 0;
l->head = l->tail = INDEXER_NULL;
}
static struct entry *l_head(struct entry_space *es, struct ilist *l)
{
return to_entry(es, l->head);
}
static struct entry *l_tail(struct entry_space *es, struct ilist *l)
{
return to_entry(es, l->tail);
}
static struct entry *l_next(struct entry_space *es, struct entry *e)
{
return to_entry(es, e->next);
}
static struct entry *l_prev(struct entry_space *es, struct entry *e)
{
return to_entry(es, e->prev);
}
static bool l_empty(struct ilist *l)
{
return l->head == INDEXER_NULL;
}
static void l_add_head(struct entry_space *es, struct ilist *l, struct entry *e)
{
struct entry *head = l_head(es, l);
e->next = l->head;
e->prev = INDEXER_NULL;
if (head)
head->prev = l->head = to_index(es, e);
else
l->head = l->tail = to_index(es, e);
if (!e->sentinel)
l->nr_elts++;
}
static void l_add_tail(struct entry_space *es, struct ilist *l, struct entry *e)
{
struct entry *tail = l_tail(es, l);
e->next = INDEXER_NULL;
e->prev = l->tail;
if (tail)
tail->next = l->tail = to_index(es, e);
else
l->head = l->tail = to_index(es, e);
if (!e->sentinel)
l->nr_elts++;
}
static void l_add_before(struct entry_space *es, struct ilist *l,
struct entry *old, struct entry *e)
{
struct entry *prev = l_prev(es, old);
if (!prev)
l_add_head(es, l, e);
else {
e->prev = old->prev;
e->next = to_index(es, old);
prev->next = old->prev = to_index(es, e);
if (!e->sentinel)
l->nr_elts++;
}
}
static void l_del(struct entry_space *es, struct ilist *l, struct entry *e)
{
struct entry *prev = l_prev(es, e);
struct entry *next = l_next(es, e);
if (prev)
prev->next = e->next;
else
l->head = e->next;
if (next)
next->prev = e->prev;
else
l->tail = e->prev;
if (!e->sentinel)
l->nr_elts--;
}
static struct entry *l_pop_head(struct entry_space *es, struct ilist *l)
{
struct entry *e;
for (e = l_head(es, l); e; e = l_next(es, e))
if (!e->sentinel) {
l_del(es, l, e);
return e;
}
return NULL;
}
static struct entry *l_pop_tail(struct entry_space *es, struct ilist *l)
{
struct entry *e;
for (e = l_tail(es, l); e; e = l_prev(es, e))
if (!e->sentinel) {
l_del(es, l, e);
return e;
}
return NULL;
}
/*----------------------------------------------------------------*/
/*
* The stochastic-multi-queue is a set of lru lists stacked into levels.
* Entries are moved up levels when they are used, which loosely orders the
* most accessed entries in the top levels and least in the bottom. This
* structure is *much* better than a single lru list.
*/
#define MAX_LEVELS 64u
struct queue {
struct entry_space *es;
unsigned int nr_elts;
unsigned int nr_levels;
struct ilist qs[MAX_LEVELS];
/*
* We maintain a count of the number of entries we would like in each
* level.
*/
unsigned int last_target_nr_elts;
unsigned int nr_top_levels;
unsigned int nr_in_top_levels;
unsigned int target_count[MAX_LEVELS];
};
static void q_init(struct queue *q, struct entry_space *es, unsigned int nr_levels)
{
unsigned int i;
q->es = es;
q->nr_elts = 0;
q->nr_levels = nr_levels;
for (i = 0; i < q->nr_levels; i++) {
l_init(q->qs + i);
q->target_count[i] = 0u;
}
q->last_target_nr_elts = 0u;
q->nr_top_levels = 0u;
q->nr_in_top_levels = 0u;
}
static unsigned int q_size(struct queue *q)
{
return q->nr_elts;
}
/*
* Insert an entry to the back of the given level.
*/
static void q_push(struct queue *q, struct entry *e)
{
BUG_ON(e->pending_work);
if (!e->sentinel)
q->nr_elts++;
l_add_tail(q->es, q->qs + e->level, e);
}
static void q_push_front(struct queue *q, struct entry *e)
{
BUG_ON(e->pending_work);
if (!e->sentinel)
q->nr_elts++;
l_add_head(q->es, q->qs + e->level, e);
}
static void q_push_before(struct queue *q, struct entry *old, struct entry *e)
{
BUG_ON(e->pending_work);
if (!e->sentinel)
q->nr_elts++;
l_add_before(q->es, q->qs + e->level, old, e);
}
static void q_del(struct queue *q, struct entry *e)
{
l_del(q->es, q->qs + e->level, e);
if (!e->sentinel)
q->nr_elts--;
}
/*
* Return the oldest entry of the lowest populated level.
*/
static struct entry *q_peek(struct queue *q, unsigned int max_level, bool can_cross_sentinel)
{
unsigned int level;
struct entry *e;
max_level = min(max_level, q->nr_levels);
for (level = 0; level < max_level; level++)
for (e = l_head(q->es, q->qs + level); e; e = l_next(q->es, e)) {
if (e->sentinel) {
if (can_cross_sentinel)
continue;
else
break;
}
return e;
}
return NULL;
}
static struct entry *q_pop(struct queue *q)
{
struct entry *e = q_peek(q, q->nr_levels, true);
if (e)
q_del(q, e);
return e;
}
/*
* This function assumes there is a non-sentinel entry to pop. It's only
* used by redistribute, so we know this is true. It also doesn't adjust
* the q->nr_elts count.
*/
static struct entry *__redist_pop_from(struct queue *q, unsigned int level)
{
struct entry *e;
for (; level < q->nr_levels; level++)
for (e = l_head(q->es, q->qs + level); e; e = l_next(q->es, e))
if (!e->sentinel) {
l_del(q->es, q->qs + e->level, e);
return e;
}
return NULL;
}
static void q_set_targets_subrange_(struct queue *q, unsigned int nr_elts,
unsigned int lbegin, unsigned int lend)
{
unsigned int level, nr_levels, entries_per_level, remainder;
BUG_ON(lbegin > lend);
BUG_ON(lend > q->nr_levels);
nr_levels = lend - lbegin;
entries_per_level = safe_div(nr_elts, nr_levels);
remainder = safe_mod(nr_elts, nr_levels);
for (level = lbegin; level < lend; level++)
q->target_count[level] =
(level < (lbegin + remainder)) ? entries_per_level + 1u : entries_per_level;
}
/*
* Typically we have fewer elements in the top few levels which allows us
* to adjust the promote threshold nicely.
*/
static void q_set_targets(struct queue *q)
{
if (q->last_target_nr_elts == q->nr_elts)
return;
q->last_target_nr_elts = q->nr_elts;
if (q->nr_top_levels > q->nr_levels)
q_set_targets_subrange_(q, q->nr_elts, 0, q->nr_levels);
else {
q_set_targets_subrange_(q, q->nr_in_top_levels,
q->nr_levels - q->nr_top_levels, q->nr_levels);
if (q->nr_in_top_levels < q->nr_elts)
q_set_targets_subrange_(q, q->nr_elts - q->nr_in_top_levels,
0, q->nr_levels - q->nr_top_levels);
else
q_set_targets_subrange_(q, 0, 0, q->nr_levels - q->nr_top_levels);
}
}
static void q_redistribute(struct queue *q)
{
unsigned int target, level;
struct ilist *l, *l_above;
struct entry *e;
q_set_targets(q);
for (level = 0u; level < q->nr_levels - 1u; level++) {
l = q->qs + level;
target = q->target_count[level];
/*
* Pull down some entries from the level above.
*/
while (l->nr_elts < target) {
e = __redist_pop_from(q, level + 1u);
if (!e) {
/* bug in nr_elts */
break;
}
e->level = level;
l_add_tail(q->es, l, e);
}
/*
* Push some entries up.
*/
l_above = q->qs + level + 1u;
while (l->nr_elts > target) {
e = l_pop_tail(q->es, l);
if (!e)
/* bug in nr_elts */
break;
e->level = level + 1u;
l_add_tail(q->es, l_above, e);
}
}
}
static void q_requeue(struct queue *q, struct entry *e, unsigned int extra_levels,
struct entry *s1, struct entry *s2)
{
struct entry *de;
unsigned int sentinels_passed = 0;
unsigned int new_level = min(q->nr_levels - 1u, e->level + extra_levels);
/* try and find an entry to swap with */
if (extra_levels && (e->level < q->nr_levels - 1u)) {
for (de = l_head(q->es, q->qs + new_level); de && de->sentinel; de = l_next(q->es, de))
sentinels_passed++;
if (de) {
q_del(q, de);
de->level = e->level;
if (s1) {
switch (sentinels_passed) {
case 0:
q_push_before(q, s1, de);
break;
case 1:
q_push_before(q, s2, de);
break;
default:
q_push(q, de);
}
} else
q_push(q, de);
}
}
q_del(q, e);
e->level = new_level;
q_push(q, e);
}
/*----------------------------------------------------------------*/
#define FP_SHIFT 8
#define SIXTEENTH (1u << (FP_SHIFT - 4u))
#define EIGHTH (1u << (FP_SHIFT - 3u))
struct stats {
unsigned int hit_threshold;
unsigned int hits;
unsigned int misses;
};
enum performance {
Q_POOR,
Q_FAIR,
Q_WELL
};
static void stats_init(struct stats *s, unsigned int nr_levels)
{
s->hit_threshold = (nr_levels * 3u) / 4u;
s->hits = 0u;
s->misses = 0u;
}
static void stats_reset(struct stats *s)
{
s->hits = s->misses = 0u;
}
static void stats_level_accessed(struct stats *s, unsigned int level)
{
if (level >= s->hit_threshold)
s->hits++;
else
s->misses++;
}
static void stats_miss(struct stats *s)
{
s->misses++;
}
/*
* There are times when we don't have any confidence in the hotspot queue.
* Such as when a fresh cache is created and the blocks have been spread
* out across the levels, or if an io load changes. We detect this by
* seeing how often a lookup is in the top levels of the hotspot queue.
*/
static enum performance stats_assess(struct stats *s)
{
unsigned int confidence = safe_div(s->hits << FP_SHIFT, s->hits + s->misses);
if (confidence < SIXTEENTH)
return Q_POOR;
else if (confidence < EIGHTH)
return Q_FAIR;
else
return Q_WELL;
}
/*----------------------------------------------------------------*/
struct smq_hash_table {
struct entry_space *es;
unsigned long long hash_bits;
unsigned int *buckets;
};
/*
* All cache entries are stored in a chained hash table. To save space we
* use indexing again, and only store indexes to the next entry.
*/
static int h_init(struct smq_hash_table *ht, struct entry_space *es, unsigned int nr_entries)
{
unsigned int i, nr_buckets;
ht->es = es;
nr_buckets = roundup_pow_of_two(max(nr_entries / 4u, 16u));
ht->hash_bits = __ffs(nr_buckets);
ht->buckets = vmalloc(array_size(nr_buckets, sizeof(*ht->buckets)));
if (!ht->buckets)
return -ENOMEM;
for (i = 0; i < nr_buckets; i++)
ht->buckets[i] = INDEXER_NULL;
return 0;
}
static void h_exit(struct smq_hash_table *ht)
{
vfree(ht->buckets);
}
static struct entry *h_head(struct smq_hash_table *ht, unsigned int bucket)
{
return to_entry(ht->es, ht->buckets[bucket]);
}
static struct entry *h_next(struct smq_hash_table *ht, struct entry *e)
{
return to_entry(ht->es, e->hash_next);
}
static void __h_insert(struct smq_hash_table *ht, unsigned int bucket, struct entry *e)
{
e->hash_next = ht->buckets[bucket];
ht->buckets[bucket] = to_index(ht->es, e);
}
static void h_insert(struct smq_hash_table *ht, struct entry *e)
{
unsigned int h = hash_64(from_oblock(e->oblock), ht->hash_bits);
__h_insert(ht, h, e);
}
static struct entry *__h_lookup(struct smq_hash_table *ht, unsigned int h, dm_oblock_t oblock,
struct entry **prev)
{
struct entry *e;
*prev = NULL;
for (e = h_head(ht, h); e; e = h_next(ht, e)) {
if (e->oblock == oblock)
return e;
*prev = e;
}
return NULL;
}
static void __h_unlink(struct smq_hash_table *ht, unsigned int h,
struct entry *e, struct entry *prev)
{
if (prev)
prev->hash_next = e->hash_next;
else
ht->buckets[h] = e->hash_next;
}
/*
* Also moves each entry to the front of the bucket.
*/
static struct entry *h_lookup(struct smq_hash_table *ht, dm_oblock_t oblock)
{
struct entry *e, *prev;
unsigned int h = hash_64(from_oblock(oblock), ht->hash_bits);
e = __h_lookup(ht, h, oblock, &prev);
if (e && prev) {
/*
* Move to the front because this entry is likely
* to be hit again.
*/
__h_unlink(ht, h, e, prev);
__h_insert(ht, h, e);
}
return e;
}
static void h_remove(struct smq_hash_table *ht, struct entry *e)
{
unsigned int h = hash_64(from_oblock(e->oblock), ht->hash_bits);
struct entry *prev;
/*
* The down side of using a singly linked list is we have to
* iterate the bucket to remove an item.
*/
e = __h_lookup(ht, h, e->oblock, &prev);
if (e)
__h_unlink(ht, h, e, prev);
}
/*----------------------------------------------------------------*/
struct entry_alloc {
struct entry_space *es;
unsigned int begin;
unsigned int nr_allocated;
struct ilist free;
};
static void init_allocator(struct entry_alloc *ea, struct entry_space *es,
unsigned int begin, unsigned int end)
{
unsigned int i;
ea->es = es;
ea->nr_allocated = 0u;
ea->begin = begin;
l_init(&ea->free);
for (i = begin; i != end; i++)
l_add_tail(ea->es, &ea->free, __get_entry(ea->es, i));
}
static void init_entry(struct entry *e)
{
/*
* We can't memset because that would clear the hotspot and
* sentinel bits which remain constant.
*/
e->hash_next = INDEXER_NULL;
e->next = INDEXER_NULL;
e->prev = INDEXER_NULL;
e->level = 0u;
e->dirty = true; /* FIXME: audit */
e->allocated = true;
e->sentinel = false;
e->pending_work = false;
}
static struct entry *alloc_entry(struct entry_alloc *ea)
{
struct entry *e;
if (l_empty(&ea->free))
return NULL;
e = l_pop_head(ea->es, &ea->free);
init_entry(e);
ea->nr_allocated++;
return e;
}
/*
* This assumes the cblock hasn't already been allocated.
*/
static struct entry *alloc_particular_entry(struct entry_alloc *ea, unsigned int i)
{
struct entry *e = __get_entry(ea->es, ea->begin + i);
BUG_ON(e->allocated);
l_del(ea->es, &ea->free, e);
init_entry(e);
ea->nr_allocated++;
return e;
}
static void free_entry(struct entry_alloc *ea, struct entry *e)
{
BUG_ON(!ea->nr_allocated);
BUG_ON(!e->allocated);
ea->nr_allocated--;
e->allocated = false;
l_add_tail(ea->es, &ea->free, e);
}
static bool allocator_empty(struct entry_alloc *ea)
{
return l_empty(&ea->free);
}
static unsigned int get_index(struct entry_alloc *ea, struct entry *e)
{
return to_index(ea->es, e) - ea->begin;
}
static struct entry *get_entry(struct entry_alloc *ea, unsigned int index)
{
return __get_entry(ea->es, ea->begin + index);
}
/*----------------------------------------------------------------*/
#define NR_HOTSPOT_LEVELS 64u
#define NR_CACHE_LEVELS 64u
#define WRITEBACK_PERIOD (10ul * HZ)
#define DEMOTE_PERIOD (60ul * HZ)
#define HOTSPOT_UPDATE_PERIOD (HZ)
#define CACHE_UPDATE_PERIOD (60ul * HZ)
struct smq_policy {
struct dm_cache_policy policy;
/* protects everything */
spinlock_t lock;
dm_cblock_t cache_size;
sector_t cache_block_size;
sector_t hotspot_block_size;
unsigned int nr_hotspot_blocks;
unsigned int cache_blocks_per_hotspot_block;
unsigned int hotspot_level_jump;
struct entry_space es;
struct entry_alloc writeback_sentinel_alloc;
struct entry_alloc demote_sentinel_alloc;
struct entry_alloc hotspot_alloc;
struct entry_alloc cache_alloc;
unsigned long *hotspot_hit_bits;
unsigned long *cache_hit_bits;
/*
* We maintain three queues of entries. The cache proper,
* consisting of a clean and dirty queue, containing the currently
* active mappings. The hotspot queue uses a larger block size to
* track blocks that are being hit frequently and potential
* candidates for promotion to the cache.
*/
struct queue hotspot;
struct queue clean;
struct queue dirty;
struct stats hotspot_stats;
struct stats cache_stats;
/*
* Keeps track of time, incremented by the core. We use this to
* avoid attributing multiple hits within the same tick.
*/
unsigned int tick;
/*
* The hash tables allows us to quickly find an entry by origin
* block.
*/
struct smq_hash_table table;
struct smq_hash_table hotspot_table;
bool current_writeback_sentinels;
unsigned long next_writeback_period;
bool current_demote_sentinels;
unsigned long next_demote_period;
unsigned int write_promote_level;
unsigned int read_promote_level;
unsigned long next_hotspot_period;
unsigned long next_cache_period;
struct background_tracker *bg_work;
bool migrations_allowed:1;
/*
* If this is set the policy will try and clean the whole cache
* even if the device is not idle.
*/
bool cleaner:1;
};
/*----------------------------------------------------------------*/
static struct entry *get_sentinel(struct entry_alloc *ea, unsigned int level, bool which)
{
return get_entry(ea, which ? level : NR_CACHE_LEVELS + level);
}
static struct entry *writeback_sentinel(struct smq_policy *mq, unsigned int level)
{
return get_sentinel(&mq->writeback_sentinel_alloc, level, mq->current_writeback_sentinels);
}
static struct entry *demote_sentinel(struct smq_policy *mq, unsigned int level)
{
return get_sentinel(&mq->demote_sentinel_alloc, level, mq->current_demote_sentinels);
}
static void __update_writeback_sentinels(struct smq_policy *mq)
{
unsigned int level;
struct queue *q = &mq->dirty;
struct entry *sentinel;
for (level = 0; level < q->nr_levels; level++) {
sentinel = writeback_sentinel(mq, level);
q_del(q, sentinel);
q_push(q, sentinel);
}
}
static void __update_demote_sentinels(struct smq_policy *mq)
{
unsigned int level;
struct queue *q = &mq->clean;
struct entry *sentinel;
for (level = 0; level < q->nr_levels; level++) {
sentinel = demote_sentinel(mq, level);
q_del(q, sentinel);
q_push(q, sentinel);
}
}
static void update_sentinels(struct smq_policy *mq)
{
if (time_after(jiffies, mq->next_writeback_period)) {
mq->next_writeback_period = jiffies + WRITEBACK_PERIOD;
mq->current_writeback_sentinels = !mq->current_writeback_sentinels;
__update_writeback_sentinels(mq);
}
if (time_after(jiffies, mq->next_demote_period)) {
mq->next_demote_period = jiffies + DEMOTE_PERIOD;
mq->current_demote_sentinels = !mq->current_demote_sentinels;
__update_demote_sentinels(mq);
}
}
static void __sentinels_init(struct smq_policy *mq)
{
unsigned int level;
struct entry *sentinel;
for (level = 0; level < NR_CACHE_LEVELS; level++) {
sentinel = writeback_sentinel(mq, level);
sentinel->level = level;
q_push(&mq->dirty, sentinel);
sentinel = demote_sentinel(mq, level);
sentinel->level = level;
q_push(&mq->clean, sentinel);
}
}
static void sentinels_init(struct smq_policy *mq)
{
mq->next_writeback_period = jiffies + WRITEBACK_PERIOD;
mq->next_demote_period = jiffies + DEMOTE_PERIOD;
mq->current_writeback_sentinels = false;
mq->current_demote_sentinels = false;
__sentinels_init(mq);
mq->current_writeback_sentinels = !mq->current_writeback_sentinels;
mq->current_demote_sentinels = !mq->current_demote_sentinels;
__sentinels_init(mq);
}
/*----------------------------------------------------------------*/
static void del_queue(struct smq_policy *mq, struct entry *e)
{
q_del(e->dirty ? &mq->dirty : &mq->clean, e);
}
static void push_queue(struct smq_policy *mq, struct entry *e)
{
if (e->dirty)
q_push(&mq->dirty, e);
else
q_push(&mq->clean, e);
}
// !h, !q, a -> h, q, a
static void push(struct smq_policy *mq, struct entry *e)
{
h_insert(&mq->table, e);
if (!e->pending_work)
push_queue(mq, e);
}
static void push_queue_front(struct smq_policy *mq, struct entry *e)
{
if (e->dirty)
q_push_front(&mq->dirty, e);
else
q_push_front(&mq->clean, e);
}
static void push_front(struct smq_policy *mq, struct entry *e)
{
h_insert(&mq->table, e);
if (!e->pending_work)
push_queue_front(mq, e);
}
static dm_cblock_t infer_cblock(struct smq_policy *mq, struct entry *e)
{
return to_cblock(get_index(&mq->cache_alloc, e));
}
static void requeue(struct smq_policy *mq, struct entry *e)
{
/*
* Pending work has temporarily been taken out of the queues.
*/
if (e->pending_work)
return;
if (!test_and_set_bit(from_cblock(infer_cblock(mq, e)), mq->cache_hit_bits)) {
if (!e->dirty) {
q_requeue(&mq->clean, e, 1u, NULL, NULL);
return;
}
q_requeue(&mq->dirty, e, 1u,
get_sentinel(&mq->writeback_sentinel_alloc, e->level, !mq->current_writeback_sentinels),
get_sentinel(&mq->writeback_sentinel_alloc, e->level, mq->current_writeback_sentinels));
}
}
static unsigned int default_promote_level(struct smq_policy *mq)
{
/*
* The promote level depends on the current performance of the
* cache.
*
* If the cache is performing badly, then we can't afford
* to promote much without causing performance to drop below that
* of the origin device.
*
* If the cache is performing well, then we don't need to promote
* much. If it isn't broken, don't fix it.
*
* If the cache is middling then we promote more.
*
* This scheme reminds me of a graph of entropy vs probability of a
* binary variable.
*/
static const unsigned int table[] = {
1, 1, 1, 2, 4, 6, 7, 8, 7, 6, 4, 4, 3, 3, 2, 2, 1
};
unsigned int hits = mq->cache_stats.hits;
unsigned int misses = mq->cache_stats.misses;
unsigned int index = safe_div(hits << 4u, hits + misses);
return table[index];
}
static void update_promote_levels(struct smq_policy *mq)
{
/*
* If there are unused cache entries then we want to be really
* eager to promote.
*/
unsigned int threshold_level = allocator_empty(&mq->cache_alloc) ?
default_promote_level(mq) : (NR_HOTSPOT_LEVELS / 2u);
threshold_level = max(threshold_level, NR_HOTSPOT_LEVELS);
/*
* If the hotspot queue is performing badly then we have little
* confidence that we know which blocks to promote. So we cut down
* the amount of promotions.
*/
switch (stats_assess(&mq->hotspot_stats)) {
case Q_POOR:
threshold_level /= 4u;
break;
case Q_FAIR:
threshold_level /= 2u;
break;
case Q_WELL:
break;
}
mq->read_promote_level = NR_HOTSPOT_LEVELS - threshold_level;
mq->write_promote_level = (NR_HOTSPOT_LEVELS - threshold_level);
}
/*
* If the hotspot queue is performing badly, then we try and move entries
* around more quickly.
*/
static void update_level_jump(struct smq_policy *mq)
{
switch (stats_assess(&mq->hotspot_stats)) {
case Q_POOR:
mq->hotspot_level_jump = 4u;
break;
case Q_FAIR:
mq->hotspot_level_jump = 2u;
break;
case Q_WELL:
mq->hotspot_level_jump = 1u;
break;
}
}
static void end_hotspot_period(struct smq_policy *mq)
{
clear_bitset(mq->hotspot_hit_bits, mq->nr_hotspot_blocks);
update_promote_levels(mq);
if (time_after(jiffies, mq->next_hotspot_period)) {
update_level_jump(mq);
q_redistribute(&mq->hotspot);
stats_reset(&mq->hotspot_stats);
mq->next_hotspot_period = jiffies + HOTSPOT_UPDATE_PERIOD;
}
}
static void end_cache_period(struct smq_policy *mq)
{
if (time_after(jiffies, mq->next_cache_period)) {
clear_bitset(mq->cache_hit_bits, from_cblock(mq->cache_size));
q_redistribute(&mq->dirty);
q_redistribute(&mq->clean);
stats_reset(&mq->cache_stats);
mq->next_cache_period = jiffies + CACHE_UPDATE_PERIOD;
}
}
/*----------------------------------------------------------------*/
/*
* Targets are given as a percentage.
*/
#define CLEAN_TARGET 25u
#define FREE_TARGET 25u
static unsigned int percent_to_target(struct smq_policy *mq, unsigned int p)
{
return from_cblock(mq->cache_size) * p / 100u;
}
static bool clean_target_met(struct smq_policy *mq, bool idle)
{
/*
* Cache entries may not be populated. So we cannot rely on the
* size of the clean queue.
*/
if (idle || mq->cleaner) {
/*
* We'd like to clean everything.
*/
return q_size(&mq->dirty) == 0u;
}
/*
* If we're busy we don't worry about cleaning at all.
*/
return true;
}
static bool free_target_met(struct smq_policy *mq)
{
unsigned int nr_free;
nr_free = from_cblock(mq->cache_size) - mq->cache_alloc.nr_allocated;
return (nr_free + btracker_nr_demotions_queued(mq->bg_work)) >=
percent_to_target(mq, FREE_TARGET);
}
/*----------------------------------------------------------------*/
static void mark_pending(struct smq_policy *mq, struct entry *e)
{
BUG_ON(e->sentinel);
BUG_ON(!e->allocated);
BUG_ON(e->pending_work);
e->pending_work = true;
}
static void clear_pending(struct smq_policy *mq, struct entry *e)
{
BUG_ON(!e->pending_work);
e->pending_work = false;
}
static void queue_writeback(struct smq_policy *mq, bool idle)
{
int r;
struct policy_work work;
struct entry *e;
e = q_peek(&mq->dirty, mq->dirty.nr_levels, idle);
if (e) {
mark_pending(mq, e);
q_del(&mq->dirty, e);
work.op = POLICY_WRITEBACK;
work.oblock = e->oblock;
work.cblock = infer_cblock(mq, e);
r = btracker_queue(mq->bg_work, &work, NULL);
if (r) {
clear_pending(mq, e);
q_push_front(&mq->dirty, e);
}
}
}
static void queue_demotion(struct smq_policy *mq)
{
int r;
struct policy_work work;
struct entry *e;
if (WARN_ON_ONCE(!mq->migrations_allowed))
return;
e = q_peek(&mq->clean, mq->clean.nr_levels / 2, true);
if (!e) {
if (!clean_target_met(mq, true))
queue_writeback(mq, false);
return;
}
mark_pending(mq, e);
q_del(&mq->clean, e);
work.op = POLICY_DEMOTE;
work.oblock = e->oblock;
work.cblock = infer_cblock(mq, e);
r = btracker_queue(mq->bg_work, &work, NULL);
if (r) {
clear_pending(mq, e);
q_push_front(&mq->clean, e);
}
}
static void queue_promotion(struct smq_policy *mq, dm_oblock_t oblock,
struct policy_work **workp)
{
int r;
struct entry *e;
struct policy_work work;
if (!mq->migrations_allowed)
return;
if (allocator_empty(&mq->cache_alloc)) {
/*
* We always claim to be 'idle' to ensure some demotions happen
* with continuous loads.
*/
if (!free_target_met(mq))
queue_demotion(mq);
return;
}
if (btracker_promotion_already_present(mq->bg_work, oblock))
return;
/*
* We allocate the entry now to reserve the cblock. If the
* background work is aborted we must remember to free it.
*/
e = alloc_entry(&mq->cache_alloc);
BUG_ON(!e);
e->pending_work = true;
work.op = POLICY_PROMOTE;
work.oblock = oblock;
work.cblock = infer_cblock(mq, e);
r = btracker_queue(mq->bg_work, &work, workp);
if (r)
free_entry(&mq->cache_alloc, e);
}
/*----------------------------------------------------------------*/
enum promote_result {
PROMOTE_NOT,
PROMOTE_TEMPORARY,
PROMOTE_PERMANENT
};
/*
* Converts a boolean into a promote result.
*/
static enum promote_result maybe_promote(bool promote)
{
return promote ? PROMOTE_PERMANENT : PROMOTE_NOT;
}
static enum promote_result should_promote(struct smq_policy *mq, struct entry *hs_e,
int data_dir, bool fast_promote)
{
if (data_dir == WRITE) {
if (!allocator_empty(&mq->cache_alloc) && fast_promote)
return PROMOTE_TEMPORARY;
return maybe_promote(hs_e->level >= mq->write_promote_level);
} else
return maybe_promote(hs_e->level >= mq->read_promote_level);
}
static dm_oblock_t to_hblock(struct smq_policy *mq, dm_oblock_t b)
{
sector_t r = from_oblock(b);
(void) sector_div(r, mq->cache_blocks_per_hotspot_block);
return to_oblock(r);
}
static struct entry *update_hotspot_queue(struct smq_policy *mq, dm_oblock_t b)
{
unsigned int hi;
dm_oblock_t hb = to_hblock(mq, b);
struct entry *e = h_lookup(&mq->hotspot_table, hb);
if (e) {
stats_level_accessed(&mq->hotspot_stats, e->level);
hi = get_index(&mq->hotspot_alloc, e);
q_requeue(&mq->hotspot, e,
test_and_set_bit(hi, mq->hotspot_hit_bits) ?
0u : mq->hotspot_level_jump,
NULL, NULL);
} else {
stats_miss(&mq->hotspot_stats);
e = alloc_entry(&mq->hotspot_alloc);
if (!e) {
e = q_pop(&mq->hotspot);
if (e) {
h_remove(&mq->hotspot_table, e);
hi = get_index(&mq->hotspot_alloc, e);
clear_bit(hi, mq->hotspot_hit_bits);
}
}
if (e) {
e->oblock = hb;
q_push(&mq->hotspot, e);
h_insert(&mq->hotspot_table, e);
}
}
return e;
}
/*----------------------------------------------------------------*/
/*
* Public interface, via the policy struct. See dm-cache-policy.h for a
* description of these.
*/
static struct smq_policy *to_smq_policy(struct dm_cache_policy *p)
{
return container_of(p, struct smq_policy, policy);
}
static void smq_destroy(struct dm_cache_policy *p)
{
struct smq_policy *mq = to_smq_policy(p);
btracker_destroy(mq->bg_work);
h_exit(&mq->hotspot_table);
h_exit(&mq->table);
free_bitset(mq->hotspot_hit_bits);
free_bitset(mq->cache_hit_bits);
space_exit(&mq->es);
kfree(mq);
}
/*----------------------------------------------------------------*/
static int __lookup(struct smq_policy *mq, dm_oblock_t oblock, dm_cblock_t *cblock,
int data_dir, bool fast_copy,
struct policy_work **work, bool *background_work)
{
struct entry *e, *hs_e;
enum promote_result pr;
*background_work = false;
e = h_lookup(&mq->table, oblock);
if (e) {
stats_level_accessed(&mq->cache_stats, e->level);
requeue(mq, e);
*cblock = infer_cblock(mq, e);
return 0;
} else {
stats_miss(&mq->cache_stats);
/*
* The hotspot queue only gets updated with misses.
*/
hs_e = update_hotspot_queue(mq, oblock);
pr = should_promote(mq, hs_e, data_dir, fast_copy);
if (pr != PROMOTE_NOT) {
queue_promotion(mq, oblock, work);
*background_work = true;
}
return -ENOENT;
}
}
static int smq_lookup(struct dm_cache_policy *p, dm_oblock_t oblock, dm_cblock_t *cblock,
int data_dir, bool fast_copy,
bool *background_work)
{
int r;
unsigned long flags;
struct smq_policy *mq = to_smq_policy(p);
spin_lock_irqsave(&mq->lock, flags);
r = __lookup(mq, oblock, cblock,
data_dir, fast_copy,
NULL, background_work);
spin_unlock_irqrestore(&mq->lock, flags);
return r;
}
static int smq_lookup_with_work(struct dm_cache_policy *p,
dm_oblock_t oblock, dm_cblock_t *cblock,
int data_dir, bool fast_copy,
struct policy_work **work)
{
int r;
bool background_queued;
unsigned long flags;
struct smq_policy *mq = to_smq_policy(p);
spin_lock_irqsave(&mq->lock, flags);
r = __lookup(mq, oblock, cblock, data_dir, fast_copy, work, &background_queued);
spin_unlock_irqrestore(&mq->lock, flags);
return r;
}
static int smq_get_background_work(struct dm_cache_policy *p, bool idle,
struct policy_work **result)
{
int r;
unsigned long flags;
struct smq_policy *mq = to_smq_policy(p);
spin_lock_irqsave(&mq->lock, flags);
r = btracker_issue(mq->bg_work, result);
if (r == -ENODATA) {
if (!clean_target_met(mq, idle)) {
queue_writeback(mq, idle);
r = btracker_issue(mq->bg_work, result);
}
}
spin_unlock_irqrestore(&mq->lock, flags);
return r;
}
/*
* We need to clear any pending work flags that have been set, and in the
* case of promotion free the entry for the destination cblock.
*/
static void __complete_background_work(struct smq_policy *mq,
struct policy_work *work,
bool success)
{
struct entry *e = get_entry(&mq->cache_alloc,
from_cblock(work->cblock));
switch (work->op) {
case POLICY_PROMOTE:
// !h, !q, a
clear_pending(mq, e);
if (success) {
e->oblock = work->oblock;
e->level = NR_CACHE_LEVELS - 1;
push(mq, e);
// h, q, a
} else {
free_entry(&mq->cache_alloc, e);
// !h, !q, !a
}
break;
case POLICY_DEMOTE:
// h, !q, a
if (success) {
h_remove(&mq->table, e);
free_entry(&mq->cache_alloc, e);
// !h, !q, !a
} else {
clear_pending(mq, e);
push_queue(mq, e);
// h, q, a
}
break;
case POLICY_WRITEBACK:
// h, !q, a
clear_pending(mq, e);
push_queue(mq, e);
// h, q, a
break;
}
btracker_complete(mq->bg_work, work);
}
static void smq_complete_background_work(struct dm_cache_policy *p,
struct policy_work *work,
bool success)
{
unsigned long flags;
struct smq_policy *mq = to_smq_policy(p);
spin_lock_irqsave(&mq->lock, flags);
__complete_background_work(mq, work, success);
spin_unlock_irqrestore(&mq->lock, flags);
}
// in_hash(oblock) -> in_hash(oblock)
static void __smq_set_clear_dirty(struct smq_policy *mq, dm_cblock_t cblock, bool set)
{
struct entry *e = get_entry(&mq->cache_alloc, from_cblock(cblock));
if (e->pending_work)
e->dirty = set;
else {
del_queue(mq, e);
e->dirty = set;
push_queue(mq, e);
}
}
static void smq_set_dirty(struct dm_cache_policy *p, dm_cblock_t cblock)
{
unsigned long flags;
struct smq_policy *mq = to_smq_policy(p);
spin_lock_irqsave(&mq->lock, flags);
__smq_set_clear_dirty(mq, cblock, true);
spin_unlock_irqrestore(&mq->lock, flags);
}
static void smq_clear_dirty(struct dm_cache_policy *p, dm_cblock_t cblock)
{
struct smq_policy *mq = to_smq_policy(p);
unsigned long flags;
spin_lock_irqsave(&mq->lock, flags);
__smq_set_clear_dirty(mq, cblock, false);
spin_unlock_irqrestore(&mq->lock, flags);
}
static unsigned int random_level(dm_cblock_t cblock)
{
return hash_32(from_cblock(cblock), 9) & (NR_CACHE_LEVELS - 1);
}
static int smq_load_mapping(struct dm_cache_policy *p,
dm_oblock_t oblock, dm_cblock_t cblock,
bool dirty, uint32_t hint, bool hint_valid)
{
struct smq_policy *mq = to_smq_policy(p);
struct entry *e;
e = alloc_particular_entry(&mq->cache_alloc, from_cblock(cblock));
e->oblock = oblock;
e->dirty = dirty;
e->level = hint_valid ? min(hint, NR_CACHE_LEVELS - 1) : random_level(cblock);
e->pending_work = false;
/*
* When we load mappings we push ahead of both sentinels in order to
* allow demotions and cleaning to occur immediately.
*/
push_front(mq, e);
return 0;
}
static int smq_invalidate_mapping(struct dm_cache_policy *p, dm_cblock_t cblock)
{
struct smq_policy *mq = to_smq_policy(p);
struct entry *e = get_entry(&mq->cache_alloc, from_cblock(cblock));
if (!e->allocated)
return -ENODATA;
// FIXME: what if this block has pending background work?
del_queue(mq, e);
h_remove(&mq->table, e);
free_entry(&mq->cache_alloc, e);
return 0;
}
static uint32_t smq_get_hint(struct dm_cache_policy *p, dm_cblock_t cblock)
{
struct smq_policy *mq = to_smq_policy(p);
struct entry *e = get_entry(&mq->cache_alloc, from_cblock(cblock));
if (!e->allocated)
return 0;
return e->level;
}
static dm_cblock_t smq_residency(struct dm_cache_policy *p)
{
dm_cblock_t r;
unsigned long flags;
struct smq_policy *mq = to_smq_policy(p);
spin_lock_irqsave(&mq->lock, flags);
r = to_cblock(mq->cache_alloc.nr_allocated);
spin_unlock_irqrestore(&mq->lock, flags);
return r;
}
static void smq_tick(struct dm_cache_policy *p, bool can_block)
{
struct smq_policy *mq = to_smq_policy(p);
unsigned long flags;
spin_lock_irqsave(&mq->lock, flags);
mq->tick++;
update_sentinels(mq);
end_hotspot_period(mq);
end_cache_period(mq);
spin_unlock_irqrestore(&mq->lock, flags);
}
static void smq_allow_migrations(struct dm_cache_policy *p, bool allow)
{
struct smq_policy *mq = to_smq_policy(p);
mq->migrations_allowed = allow;
}
/*
* smq has no config values, but the old mq policy did. To avoid breaking
* software we continue to accept these configurables for the mq policy,
* but they have no effect.
*/
static int mq_set_config_value(struct dm_cache_policy *p,
const char *key, const char *value)
{
unsigned long tmp;
if (kstrtoul(value, 10, &tmp))
return -EINVAL;
if (!strcasecmp(key, "random_threshold") ||
!strcasecmp(key, "sequential_threshold") ||
!strcasecmp(key, "discard_promote_adjustment") ||
!strcasecmp(key, "read_promote_adjustment") ||
!strcasecmp(key, "write_promote_adjustment")) {
DMWARN("tunable '%s' no longer has any effect, mq policy is now an alias for smq", key);
return 0;
}
return -EINVAL;
}
static int mq_emit_config_values(struct dm_cache_policy *p, char *result,
unsigned int maxlen, ssize_t *sz_ptr)
{
ssize_t sz = *sz_ptr;
DMEMIT("10 random_threshold 0 "
"sequential_threshold 0 "
"discard_promote_adjustment 0 "
"read_promote_adjustment 0 "
"write_promote_adjustment 0 ");
*sz_ptr = sz;
return 0;
}
/* Init the policy plugin interface function pointers. */
static void init_policy_functions(struct smq_policy *mq, bool mimic_mq)
{
mq->policy.destroy = smq_destroy;
mq->policy.lookup = smq_lookup;
mq->policy.lookup_with_work = smq_lookup_with_work;
mq->policy.get_background_work = smq_get_background_work;
mq->policy.complete_background_work = smq_complete_background_work;
mq->policy.set_dirty = smq_set_dirty;
mq->policy.clear_dirty = smq_clear_dirty;
mq->policy.load_mapping = smq_load_mapping;
mq->policy.invalidate_mapping = smq_invalidate_mapping;
mq->policy.get_hint = smq_get_hint;
mq->policy.residency = smq_residency;
mq->policy.tick = smq_tick;
mq->policy.allow_migrations = smq_allow_migrations;
if (mimic_mq) {
mq->policy.set_config_value = mq_set_config_value;
mq->policy.emit_config_values = mq_emit_config_values;
}
}
static bool too_many_hotspot_blocks(sector_t origin_size,
sector_t hotspot_block_size,
unsigned int nr_hotspot_blocks)
{
return (hotspot_block_size * nr_hotspot_blocks) > origin_size;
}
static void calc_hotspot_params(sector_t origin_size,
sector_t cache_block_size,
unsigned int nr_cache_blocks,
sector_t *hotspot_block_size,
unsigned int *nr_hotspot_blocks)
{
*hotspot_block_size = cache_block_size * 16u;
*nr_hotspot_blocks = max(nr_cache_blocks / 4u, 1024u);
while ((*hotspot_block_size > cache_block_size) &&
too_many_hotspot_blocks(origin_size, *hotspot_block_size, *nr_hotspot_blocks))
*hotspot_block_size /= 2u;
}
static struct dm_cache_policy *
__smq_create(dm_cblock_t cache_size, sector_t origin_size, sector_t cache_block_size,
bool mimic_mq, bool migrations_allowed, bool cleaner)
{
unsigned int i;
unsigned int nr_sentinels_per_queue = 2u * NR_CACHE_LEVELS;
unsigned int total_sentinels = 2u * nr_sentinels_per_queue;
struct smq_policy *mq = kzalloc(sizeof(*mq), GFP_KERNEL);
if (!mq)
return NULL;
init_policy_functions(mq, mimic_mq);
mq->cache_size = cache_size;
mq->cache_block_size = cache_block_size;
calc_hotspot_params(origin_size, cache_block_size, from_cblock(cache_size),
&mq->hotspot_block_size, &mq->nr_hotspot_blocks);
mq->cache_blocks_per_hotspot_block = div64_u64(mq->hotspot_block_size, mq->cache_block_size);
mq->hotspot_level_jump = 1u;
if (space_init(&mq->es, total_sentinels + mq->nr_hotspot_blocks + from_cblock(cache_size))) {
DMERR("couldn't initialize entry space");
goto bad_pool_init;
}
init_allocator(&mq->writeback_sentinel_alloc, &mq->es, 0, nr_sentinels_per_queue);
for (i = 0; i < nr_sentinels_per_queue; i++)
get_entry(&mq->writeback_sentinel_alloc, i)->sentinel = true;
init_allocator(&mq->demote_sentinel_alloc, &mq->es, nr_sentinels_per_queue, total_sentinels);
for (i = 0; i < nr_sentinels_per_queue; i++)
get_entry(&mq->demote_sentinel_alloc, i)->sentinel = true;
init_allocator(&mq->hotspot_alloc, &mq->es, total_sentinels,
total_sentinels + mq->nr_hotspot_blocks);
init_allocator(&mq->cache_alloc, &mq->es,
total_sentinels + mq->nr_hotspot_blocks,
total_sentinels + mq->nr_hotspot_blocks + from_cblock(cache_size));
mq->hotspot_hit_bits = alloc_bitset(mq->nr_hotspot_blocks);
if (!mq->hotspot_hit_bits) {
DMERR("couldn't allocate hotspot hit bitset");
goto bad_hotspot_hit_bits;
}
clear_bitset(mq->hotspot_hit_bits, mq->nr_hotspot_blocks);
if (from_cblock(cache_size)) {
mq->cache_hit_bits = alloc_bitset(from_cblock(cache_size));
if (!mq->cache_hit_bits) {
DMERR("couldn't allocate cache hit bitset");
goto bad_cache_hit_bits;
}
clear_bitset(mq->cache_hit_bits, from_cblock(mq->cache_size));
} else
mq->cache_hit_bits = NULL;
mq->tick = 0;
spin_lock_init(&mq->lock);
q_init(&mq->hotspot, &mq->es, NR_HOTSPOT_LEVELS);
mq->hotspot.nr_top_levels = 8;
mq->hotspot.nr_in_top_levels = min(mq->nr_hotspot_blocks / NR_HOTSPOT_LEVELS,
from_cblock(mq->cache_size) / mq->cache_blocks_per_hotspot_block);
q_init(&mq->clean, &mq->es, NR_CACHE_LEVELS);
q_init(&mq->dirty, &mq->es, NR_CACHE_LEVELS);
stats_init(&mq->hotspot_stats, NR_HOTSPOT_LEVELS);
stats_init(&mq->cache_stats, NR_CACHE_LEVELS);
if (h_init(&mq->table, &mq->es, from_cblock(cache_size)))
goto bad_alloc_table;
if (h_init(&mq->hotspot_table, &mq->es, mq->nr_hotspot_blocks))
goto bad_alloc_hotspot_table;
sentinels_init(mq);
mq->write_promote_level = mq->read_promote_level = NR_HOTSPOT_LEVELS;
mq->next_hotspot_period = jiffies;
mq->next_cache_period = jiffies;
mq->bg_work = btracker_create(4096); /* FIXME: hard coded value */
if (!mq->bg_work)
goto bad_btracker;
mq->migrations_allowed = migrations_allowed;
mq->cleaner = cleaner;
return &mq->policy;
bad_btracker:
h_exit(&mq->hotspot_table);
bad_alloc_hotspot_table:
h_exit(&mq->table);
bad_alloc_table:
free_bitset(mq->cache_hit_bits);
bad_cache_hit_bits:
free_bitset(mq->hotspot_hit_bits);
bad_hotspot_hit_bits:
space_exit(&mq->es);
bad_pool_init:
kfree(mq);
return NULL;
}
static struct dm_cache_policy *smq_create(dm_cblock_t cache_size,
sector_t origin_size,
sector_t cache_block_size)
{
return __smq_create(cache_size, origin_size, cache_block_size,
false, true, false);
}
static struct dm_cache_policy *mq_create(dm_cblock_t cache_size,
sector_t origin_size,
sector_t cache_block_size)
{
return __smq_create(cache_size, origin_size, cache_block_size,
true, true, false);
}
static struct dm_cache_policy *cleaner_create(dm_cblock_t cache_size,
sector_t origin_size,
sector_t cache_block_size)
{
return __smq_create(cache_size, origin_size, cache_block_size,
false, false, true);
}
/*----------------------------------------------------------------*/
static struct dm_cache_policy_type smq_policy_type = {
.name = "smq",
.version = {2, 0, 0},
.hint_size = 4,
.owner = THIS_MODULE,
.create = smq_create
};
static struct dm_cache_policy_type mq_policy_type = {
.name = "mq",
.version = {2, 0, 0},
.hint_size = 4,
.owner = THIS_MODULE,
.create = mq_create,
};
static struct dm_cache_policy_type cleaner_policy_type = {
.name = "cleaner",
.version = {2, 0, 0},
.hint_size = 4,
.owner = THIS_MODULE,
.create = cleaner_create,
};
static struct dm_cache_policy_type default_policy_type = {
.name = "default",
.version = {2, 0, 0},
.hint_size = 4,
.owner = THIS_MODULE,
.create = smq_create,
.real = &smq_policy_type
};
static int __init smq_init(void)
{
int r;
r = dm_cache_policy_register(&smq_policy_type);
if (r) {
DMERR("register failed %d", r);
return -ENOMEM;
}
r = dm_cache_policy_register(&mq_policy_type);
if (r) {
DMERR("register failed (as mq) %d", r);
goto out_mq;
}
r = dm_cache_policy_register(&cleaner_policy_type);
if (r) {
DMERR("register failed (as cleaner) %d", r);
goto out_cleaner;
}
r = dm_cache_policy_register(&default_policy_type);
if (r) {
DMERR("register failed (as default) %d", r);
goto out_default;
}
return 0;
out_default:
dm_cache_policy_unregister(&cleaner_policy_type);
out_cleaner:
dm_cache_policy_unregister(&mq_policy_type);
out_mq:
dm_cache_policy_unregister(&smq_policy_type);
return -ENOMEM;
}
static void __exit smq_exit(void)
{
dm_cache_policy_unregister(&cleaner_policy_type);
dm_cache_policy_unregister(&smq_policy_type);
dm_cache_policy_unregister(&mq_policy_type);
dm_cache_policy_unregister(&default_policy_type);
}
module_init(smq_init);
module_exit(smq_exit);
MODULE_AUTHOR("Joe Thornber <[email protected]>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("smq cache policy");
MODULE_ALIAS("dm-cache-default");
MODULE_ALIAS("dm-cache-mq");
MODULE_ALIAS("dm-cache-cleaner");
| linux-master | drivers/md/dm-cache-policy-smq.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2001-2003 Sistina Software (UK) Limited.
*
* This file is released under the GPL.
*/
#include "dm.h"
#include <linux/module.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/bio.h>
#include <linux/dax.h>
#include <linux/slab.h>
#include <linux/device-mapper.h>
#define DM_MSG_PREFIX "linear"
/*
* Linear: maps a linear range of a device.
*/
struct linear_c {
struct dm_dev *dev;
sector_t start;
};
/*
* Construct a linear mapping: <dev_path> <offset>
*/
static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
struct linear_c *lc;
unsigned long long tmp;
char dummy;
int ret;
if (argc != 2) {
ti->error = "Invalid argument count";
return -EINVAL;
}
lc = kmalloc(sizeof(*lc), GFP_KERNEL);
if (lc == NULL) {
ti->error = "Cannot allocate linear context";
return -ENOMEM;
}
ret = -EINVAL;
if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1 || tmp != (sector_t)tmp) {
ti->error = "Invalid device sector";
goto bad;
}
lc->start = tmp;
ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev);
if (ret) {
ti->error = "Device lookup failed";
goto bad;
}
ti->num_flush_bios = 1;
ti->num_discard_bios = 1;
ti->num_secure_erase_bios = 1;
ti->num_write_zeroes_bios = 1;
ti->private = lc;
return 0;
bad:
kfree(lc);
return ret;
}
static void linear_dtr(struct dm_target *ti)
{
struct linear_c *lc = ti->private;
dm_put_device(ti, lc->dev);
kfree(lc);
}
static sector_t linear_map_sector(struct dm_target *ti, sector_t bi_sector)
{
struct linear_c *lc = ti->private;
return lc->start + dm_target_offset(ti, bi_sector);
}
static int linear_map(struct dm_target *ti, struct bio *bio)
{
struct linear_c *lc = ti->private;
bio_set_dev(bio, lc->dev->bdev);
bio->bi_iter.bi_sector = linear_map_sector(ti, bio->bi_iter.bi_sector);
return DM_MAPIO_REMAPPED;
}
static void linear_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
struct linear_c *lc = ti->private;
size_t sz = 0;
switch (type) {
case STATUSTYPE_INFO:
result[0] = '\0';
break;
case STATUSTYPE_TABLE:
DMEMIT("%s %llu", lc->dev->name, (unsigned long long)lc->start);
break;
case STATUSTYPE_IMA:
DMEMIT_TARGET_NAME_VERSION(ti->type);
DMEMIT(",device_name=%s,start=%llu;", lc->dev->name,
(unsigned long long)lc->start);
break;
}
}
static int linear_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
{
struct linear_c *lc = ti->private;
struct dm_dev *dev = lc->dev;
*bdev = dev->bdev;
/*
* Only pass ioctls through if the device sizes match exactly.
*/
if (lc->start || ti->len != bdev_nr_sectors(dev->bdev))
return 1;
return 0;
}
#ifdef CONFIG_BLK_DEV_ZONED
static int linear_report_zones(struct dm_target *ti,
struct dm_report_zones_args *args, unsigned int nr_zones)
{
struct linear_c *lc = ti->private;
return dm_report_zones(lc->dev->bdev, lc->start,
linear_map_sector(ti, args->next_sector),
args, nr_zones);
}
#else
#define linear_report_zones NULL
#endif
static int linear_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct linear_c *lc = ti->private;
return fn(ti, lc->dev, lc->start, ti->len, data);
}
#if IS_ENABLED(CONFIG_FS_DAX)
static struct dax_device *linear_dax_pgoff(struct dm_target *ti, pgoff_t *pgoff)
{
struct linear_c *lc = ti->private;
sector_t sector = linear_map_sector(ti, *pgoff << PAGE_SECTORS_SHIFT);
*pgoff = (get_start_sect(lc->dev->bdev) + sector) >> PAGE_SECTORS_SHIFT;
return lc->dev->dax_dev;
}
static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
long nr_pages, enum dax_access_mode mode, void **kaddr,
pfn_t *pfn)
{
struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
return dax_direct_access(dax_dev, pgoff, nr_pages, mode, kaddr, pfn);
}
static int linear_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,
size_t nr_pages)
{
struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
return dax_zero_page_range(dax_dev, pgoff, nr_pages);
}
static size_t linear_dax_recovery_write(struct dm_target *ti, pgoff_t pgoff,
void *addr, size_t bytes, struct iov_iter *i)
{
struct dax_device *dax_dev = linear_dax_pgoff(ti, &pgoff);
return dax_recovery_write(dax_dev, pgoff, addr, bytes, i);
}
#else
#define linear_dax_direct_access NULL
#define linear_dax_zero_page_range NULL
#define linear_dax_recovery_write NULL
#endif
static struct target_type linear_target = {
.name = "linear",
.version = {1, 4, 0},
.features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_NOWAIT |
DM_TARGET_ZONED_HM | DM_TARGET_PASSES_CRYPTO,
.report_zones = linear_report_zones,
.module = THIS_MODULE,
.ctr = linear_ctr,
.dtr = linear_dtr,
.map = linear_map,
.status = linear_status,
.prepare_ioctl = linear_prepare_ioctl,
.iterate_devices = linear_iterate_devices,
.direct_access = linear_dax_direct_access,
.dax_zero_page_range = linear_dax_zero_page_range,
.dax_recovery_write = linear_dax_recovery_write,
};
int __init dm_linear_init(void)
{
int r = dm_register_target(&linear_target);
if (r < 0)
DMERR("register failed %d", r);
return r;
}
void dm_linear_exit(void)
{
dm_unregister_target(&linear_target);
}
| linux-master | drivers/md/dm-linear.c |
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* raid10.c : Multiple Devices driver for Linux
*
* Copyright (C) 2000-2004 Neil Brown
*
* RAID-10 support for md.
*
* Base on code in raid1.c. See raid1.c for further copyright information.
*/
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/blkdev.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/ratelimit.h>
#include <linux/kthread.h>
#include <linux/raid/md_p.h>
#include <trace/events/block.h>
#include "md.h"
#include "raid10.h"
#include "raid0.h"
#include "md-bitmap.h"
/*
* RAID10 provides a combination of RAID0 and RAID1 functionality.
* The layout of data is defined by
* chunk_size
* raid_disks
* near_copies (stored in low byte of layout)
* far_copies (stored in second byte of layout)
* far_offset (stored in bit 16 of layout )
* use_far_sets (stored in bit 17 of layout )
* use_far_sets_bugfixed (stored in bit 18 of layout )
*
* The data to be stored is divided into chunks using chunksize. Each device
* is divided into far_copies sections. In each section, chunks are laid out
* in a style similar to raid0, but near_copies copies of each chunk is stored
* (each on a different drive). The starting device for each section is offset
* near_copies from the starting device of the previous section. Thus there
* are (near_copies * far_copies) of each chunk, and each is on a different
* drive. near_copies and far_copies must be at least one, and their product
* is at most raid_disks.
*
* If far_offset is true, then the far_copies are handled a bit differently.
* The copies are still in different stripes, but instead of being very far
* apart on disk, there are adjacent stripes.
*
* The far and offset algorithms are handled slightly differently if
* 'use_far_sets' is true. In this case, the array's devices are grouped into
* sets that are (near_copies * far_copies) in size. The far copied stripes
* are still shifted by 'near_copies' devices, but this shifting stays confined
* to the set rather than the entire array. This is done to improve the number
* of device combinations that can fail without causing the array to fail.
* Example 'far' algorithm w/o 'use_far_sets' (each letter represents a chunk
* on a device):
* A B C D A B C D E
* ... ...
* D A B C E A B C D
* Example 'far' algorithm w/ 'use_far_sets' enabled (sets illustrated w/ []'s):
* [A B] [C D] [A B] [C D E]
* |...| |...| |...| | ... |
* [B A] [D C] [B A] [E C D]
*/
static void allow_barrier(struct r10conf *conf);
static void lower_barrier(struct r10conf *conf);
static int _enough(struct r10conf *conf, int previous, int ignore);
static int enough(struct r10conf *conf, int ignore);
static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr,
int *skipped);
static void reshape_request_write(struct mddev *mddev, struct r10bio *r10_bio);
static void end_reshape_write(struct bio *bio);
static void end_reshape(struct r10conf *conf);
#define raid10_log(md, fmt, args...) \
do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid10 " fmt, ##args); } while (0)
#include "raid1-10.c"
#define NULL_CMD
#define cmd_before(conf, cmd) \
do { \
write_sequnlock_irq(&(conf)->resync_lock); \
cmd; \
} while (0)
#define cmd_after(conf) write_seqlock_irq(&(conf)->resync_lock)
#define wait_event_barrier_cmd(conf, cond, cmd) \
wait_event_cmd((conf)->wait_barrier, cond, cmd_before(conf, cmd), \
cmd_after(conf))
#define wait_event_barrier(conf, cond) \
wait_event_barrier_cmd(conf, cond, NULL_CMD)
/*
* for resync bio, r10bio pointer can be retrieved from the per-bio
* 'struct resync_pages'.
*/
static inline struct r10bio *get_resync_r10bio(struct bio *bio)
{
return get_resync_pages(bio)->raid_bio;
}
static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data)
{
struct r10conf *conf = data;
int size = offsetof(struct r10bio, devs[conf->geo.raid_disks]);
/* allocate a r10bio with room for raid_disks entries in the
* bios array */
return kzalloc(size, gfp_flags);
}
#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9)
/* amount of memory to reserve for resync requests */
#define RESYNC_WINDOW (1024*1024)
/* maximum number of concurrent requests, memory permitting */
#define RESYNC_DEPTH (32*1024*1024/RESYNC_BLOCK_SIZE)
#define CLUSTER_RESYNC_WINDOW (32 * RESYNC_WINDOW)
#define CLUSTER_RESYNC_WINDOW_SECTORS (CLUSTER_RESYNC_WINDOW >> 9)
/*
* When performing a resync, we need to read and compare, so
* we need as many pages are there are copies.
* When performing a recovery, we need 2 bios, one for read,
* one for write (we recover only one drive per r10buf)
*
*/
static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data)
{
struct r10conf *conf = data;
struct r10bio *r10_bio;
struct bio *bio;
int j;
int nalloc, nalloc_rp;
struct resync_pages *rps;
r10_bio = r10bio_pool_alloc(gfp_flags, conf);
if (!r10_bio)
return NULL;
if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery) ||
test_bit(MD_RECOVERY_RESHAPE, &conf->mddev->recovery))
nalloc = conf->copies; /* resync */
else
nalloc = 2; /* recovery */
/* allocate once for all bios */
if (!conf->have_replacement)
nalloc_rp = nalloc;
else
nalloc_rp = nalloc * 2;
rps = kmalloc_array(nalloc_rp, sizeof(struct resync_pages), gfp_flags);
if (!rps)
goto out_free_r10bio;
/*
* Allocate bios.
*/
for (j = nalloc ; j-- ; ) {
bio = bio_kmalloc(RESYNC_PAGES, gfp_flags);
if (!bio)
goto out_free_bio;
bio_init(bio, NULL, bio->bi_inline_vecs, RESYNC_PAGES, 0);
r10_bio->devs[j].bio = bio;
if (!conf->have_replacement)
continue;
bio = bio_kmalloc(RESYNC_PAGES, gfp_flags);
if (!bio)
goto out_free_bio;
bio_init(bio, NULL, bio->bi_inline_vecs, RESYNC_PAGES, 0);
r10_bio->devs[j].repl_bio = bio;
}
/*
* Allocate RESYNC_PAGES data pages and attach them
* where needed.
*/
for (j = 0; j < nalloc; j++) {
struct bio *rbio = r10_bio->devs[j].repl_bio;
struct resync_pages *rp, *rp_repl;
rp = &rps[j];
if (rbio)
rp_repl = &rps[nalloc + j];
bio = r10_bio->devs[j].bio;
if (!j || test_bit(MD_RECOVERY_SYNC,
&conf->mddev->recovery)) {
if (resync_alloc_pages(rp, gfp_flags))
goto out_free_pages;
} else {
memcpy(rp, &rps[0], sizeof(*rp));
resync_get_all_pages(rp);
}
rp->raid_bio = r10_bio;
bio->bi_private = rp;
if (rbio) {
memcpy(rp_repl, rp, sizeof(*rp));
rbio->bi_private = rp_repl;
}
}
return r10_bio;
out_free_pages:
while (--j >= 0)
resync_free_pages(&rps[j]);
j = 0;
out_free_bio:
for ( ; j < nalloc; j++) {
if (r10_bio->devs[j].bio)
bio_uninit(r10_bio->devs[j].bio);
kfree(r10_bio->devs[j].bio);
if (r10_bio->devs[j].repl_bio)
bio_uninit(r10_bio->devs[j].repl_bio);
kfree(r10_bio->devs[j].repl_bio);
}
kfree(rps);
out_free_r10bio:
rbio_pool_free(r10_bio, conf);
return NULL;
}
static void r10buf_pool_free(void *__r10_bio, void *data)
{
struct r10conf *conf = data;
struct r10bio *r10bio = __r10_bio;
int j;
struct resync_pages *rp = NULL;
for (j = conf->copies; j--; ) {
struct bio *bio = r10bio->devs[j].bio;
if (bio) {
rp = get_resync_pages(bio);
resync_free_pages(rp);
bio_uninit(bio);
kfree(bio);
}
bio = r10bio->devs[j].repl_bio;
if (bio) {
bio_uninit(bio);
kfree(bio);
}
}
/* resync pages array stored in the 1st bio's .bi_private */
kfree(rp);
rbio_pool_free(r10bio, conf);
}
static void put_all_bios(struct r10conf *conf, struct r10bio *r10_bio)
{
int i;
for (i = 0; i < conf->geo.raid_disks; i++) {
struct bio **bio = & r10_bio->devs[i].bio;
if (!BIO_SPECIAL(*bio))
bio_put(*bio);
*bio = NULL;
bio = &r10_bio->devs[i].repl_bio;
if (r10_bio->read_slot < 0 && !BIO_SPECIAL(*bio))
bio_put(*bio);
*bio = NULL;
}
}
static void free_r10bio(struct r10bio *r10_bio)
{
struct r10conf *conf = r10_bio->mddev->private;
put_all_bios(conf, r10_bio);
mempool_free(r10_bio, &conf->r10bio_pool);
}
static void put_buf(struct r10bio *r10_bio)
{
struct r10conf *conf = r10_bio->mddev->private;
mempool_free(r10_bio, &conf->r10buf_pool);
lower_barrier(conf);
}
static void wake_up_barrier(struct r10conf *conf)
{
if (wq_has_sleeper(&conf->wait_barrier))
wake_up(&conf->wait_barrier);
}
static void reschedule_retry(struct r10bio *r10_bio)
{
unsigned long flags;
struct mddev *mddev = r10_bio->mddev;
struct r10conf *conf = mddev->private;
spin_lock_irqsave(&conf->device_lock, flags);
list_add(&r10_bio->retry_list, &conf->retry_list);
conf->nr_queued ++;
spin_unlock_irqrestore(&conf->device_lock, flags);
/* wake up frozen array... */
wake_up(&conf->wait_barrier);
md_wakeup_thread(mddev->thread);
}
/*
* raid_end_bio_io() is called when we have finished servicing a mirrored
* operation and are ready to return a success/failure code to the buffer
* cache layer.
*/
static void raid_end_bio_io(struct r10bio *r10_bio)
{
struct bio *bio = r10_bio->master_bio;
struct r10conf *conf = r10_bio->mddev->private;
if (!test_bit(R10BIO_Uptodate, &r10_bio->state))
bio->bi_status = BLK_STS_IOERR;
bio_endio(bio);
/*
* Wake up any possible resync thread that waits for the device
* to go idle.
*/
allow_barrier(conf);
free_r10bio(r10_bio);
}
/*
* Update disk head position estimator based on IRQ completion info.
*/
static inline void update_head_pos(int slot, struct r10bio *r10_bio)
{
struct r10conf *conf = r10_bio->mddev->private;
conf->mirrors[r10_bio->devs[slot].devnum].head_position =
r10_bio->devs[slot].addr + (r10_bio->sectors);
}
/*
* Find the disk number which triggered given bio
*/
static int find_bio_disk(struct r10conf *conf, struct r10bio *r10_bio,
struct bio *bio, int *slotp, int *replp)
{
int slot;
int repl = 0;
for (slot = 0; slot < conf->geo.raid_disks; slot++) {
if (r10_bio->devs[slot].bio == bio)
break;
if (r10_bio->devs[slot].repl_bio == bio) {
repl = 1;
break;
}
}
update_head_pos(slot, r10_bio);
if (slotp)
*slotp = slot;
if (replp)
*replp = repl;
return r10_bio->devs[slot].devnum;
}
static void raid10_end_read_request(struct bio *bio)
{
int uptodate = !bio->bi_status;
struct r10bio *r10_bio = bio->bi_private;
int slot;
struct md_rdev *rdev;
struct r10conf *conf = r10_bio->mddev->private;
slot = r10_bio->read_slot;
rdev = r10_bio->devs[slot].rdev;
/*
* this branch is our 'one mirror IO has finished' event handler:
*/
update_head_pos(slot, r10_bio);
if (uptodate) {
/*
* Set R10BIO_Uptodate in our master bio, so that
* we will return a good error code to the higher
* levels even if IO on some other mirrored buffer fails.
*
* The 'master' represents the composite IO operation to
* user-side. So if something waits for IO, then it will
* wait for the 'master' bio.
*/
set_bit(R10BIO_Uptodate, &r10_bio->state);
} else {
/* If all other devices that store this block have
* failed, we want to return the error upwards rather
* than fail the last device. Here we redefine
* "uptodate" to mean "Don't want to retry"
*/
if (!_enough(conf, test_bit(R10BIO_Previous, &r10_bio->state),
rdev->raid_disk))
uptodate = 1;
}
if (uptodate) {
raid_end_bio_io(r10_bio);
rdev_dec_pending(rdev, conf->mddev);
} else {
/*
* oops, read error - keep the refcount on the rdev
*/
pr_err_ratelimited("md/raid10:%s: %pg: rescheduling sector %llu\n",
mdname(conf->mddev),
rdev->bdev,
(unsigned long long)r10_bio->sector);
set_bit(R10BIO_ReadError, &r10_bio->state);
reschedule_retry(r10_bio);
}
}
static void close_write(struct r10bio *r10_bio)
{
/* clear the bitmap if all writes complete successfully */
md_bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector,
r10_bio->sectors,
!test_bit(R10BIO_Degraded, &r10_bio->state),
0);
md_write_end(r10_bio->mddev);
}
static void one_write_done(struct r10bio *r10_bio)
{
if (atomic_dec_and_test(&r10_bio->remaining)) {
if (test_bit(R10BIO_WriteError, &r10_bio->state))
reschedule_retry(r10_bio);
else {
close_write(r10_bio);
if (test_bit(R10BIO_MadeGood, &r10_bio->state))
reschedule_retry(r10_bio);
else
raid_end_bio_io(r10_bio);
}
}
}
static void raid10_end_write_request(struct bio *bio)
{
struct r10bio *r10_bio = bio->bi_private;
int dev;
int dec_rdev = 1;
struct r10conf *conf = r10_bio->mddev->private;
int slot, repl;
struct md_rdev *rdev = NULL;
struct bio *to_put = NULL;
bool discard_error;
discard_error = bio->bi_status && bio_op(bio) == REQ_OP_DISCARD;
dev = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
if (repl)
rdev = conf->mirrors[dev].replacement;
if (!rdev) {
smp_rmb();
repl = 0;
rdev = conf->mirrors[dev].rdev;
}
/*
* this branch is our 'one mirror IO has finished' event handler:
*/
if (bio->bi_status && !discard_error) {
if (repl)
/* Never record new bad blocks to replacement,
* just fail it.
*/
md_error(rdev->mddev, rdev);
else {
set_bit(WriteErrorSeen, &rdev->flags);
if (!test_and_set_bit(WantReplacement, &rdev->flags))
set_bit(MD_RECOVERY_NEEDED,
&rdev->mddev->recovery);
dec_rdev = 0;
if (test_bit(FailFast, &rdev->flags) &&
(bio->bi_opf & MD_FAILFAST)) {
md_error(rdev->mddev, rdev);
}
/*
* When the device is faulty, it is not necessary to
* handle write error.
*/
if (!test_bit(Faulty, &rdev->flags))
set_bit(R10BIO_WriteError, &r10_bio->state);
else {
/* Fail the request */
set_bit(R10BIO_Degraded, &r10_bio->state);
r10_bio->devs[slot].bio = NULL;
to_put = bio;
dec_rdev = 1;
}
}
} else {
/*
* Set R10BIO_Uptodate in our master bio, so that
* we will return a good error code for to the higher
* levels even if IO on some other mirrored buffer fails.
*
* The 'master' represents the composite IO operation to
* user-side. So if something waits for IO, then it will
* wait for the 'master' bio.
*/
sector_t first_bad;
int bad_sectors;
/*
* Do not set R10BIO_Uptodate if the current device is
* rebuilding or Faulty. This is because we cannot use
* such device for properly reading the data back (we could
* potentially use it, if the current write would have felt
* before rdev->recovery_offset, but for simplicity we don't
* check this here.
*/
if (test_bit(In_sync, &rdev->flags) &&
!test_bit(Faulty, &rdev->flags))
set_bit(R10BIO_Uptodate, &r10_bio->state);
/* Maybe we can clear some bad blocks. */
if (is_badblock(rdev,
r10_bio->devs[slot].addr,
r10_bio->sectors,
&first_bad, &bad_sectors) && !discard_error) {
bio_put(bio);
if (repl)
r10_bio->devs[slot].repl_bio = IO_MADE_GOOD;
else
r10_bio->devs[slot].bio = IO_MADE_GOOD;
dec_rdev = 0;
set_bit(R10BIO_MadeGood, &r10_bio->state);
}
}
/*
*
* Let's see if all mirrored write operations have finished
* already.
*/
one_write_done(r10_bio);
if (dec_rdev)
rdev_dec_pending(rdev, conf->mddev);
if (to_put)
bio_put(to_put);
}
/*
* RAID10 layout manager
* As well as the chunksize and raid_disks count, there are two
* parameters: near_copies and far_copies.
* near_copies * far_copies must be <= raid_disks.
* Normally one of these will be 1.
* If both are 1, we get raid0.
* If near_copies == raid_disks, we get raid1.
*
* Chunks are laid out in raid0 style with near_copies copies of the
* first chunk, followed by near_copies copies of the next chunk and
* so on.
* If far_copies > 1, then after 1/far_copies of the array has been assigned
* as described above, we start again with a device offset of near_copies.
* So we effectively have another copy of the whole array further down all
* the drives, but with blocks on different drives.
* With this layout, and block is never stored twice on the one device.
*
* raid10_find_phys finds the sector offset of a given virtual sector
* on each device that it is on.
*
* raid10_find_virt does the reverse mapping, from a device and a
* sector offset to a virtual address
*/
static void __raid10_find_phys(struct geom *geo, struct r10bio *r10bio)
{
int n,f;
sector_t sector;
sector_t chunk;
sector_t stripe;
int dev;
int slot = 0;
int last_far_set_start, last_far_set_size;
last_far_set_start = (geo->raid_disks / geo->far_set_size) - 1;
last_far_set_start *= geo->far_set_size;
last_far_set_size = geo->far_set_size;
last_far_set_size += (geo->raid_disks % geo->far_set_size);
/* now calculate first sector/dev */
chunk = r10bio->sector >> geo->chunk_shift;
sector = r10bio->sector & geo->chunk_mask;
chunk *= geo->near_copies;
stripe = chunk;
dev = sector_div(stripe, geo->raid_disks);
if (geo->far_offset)
stripe *= geo->far_copies;
sector += stripe << geo->chunk_shift;
/* and calculate all the others */
for (n = 0; n < geo->near_copies; n++) {
int d = dev;
int set;
sector_t s = sector;
r10bio->devs[slot].devnum = d;
r10bio->devs[slot].addr = s;
slot++;
for (f = 1; f < geo->far_copies; f++) {
set = d / geo->far_set_size;
d += geo->near_copies;
if ((geo->raid_disks % geo->far_set_size) &&
(d > last_far_set_start)) {
d -= last_far_set_start;
d %= last_far_set_size;
d += last_far_set_start;
} else {
d %= geo->far_set_size;
d += geo->far_set_size * set;
}
s += geo->stride;
r10bio->devs[slot].devnum = d;
r10bio->devs[slot].addr = s;
slot++;
}
dev++;
if (dev >= geo->raid_disks) {
dev = 0;
sector += (geo->chunk_mask + 1);
}
}
}
static void raid10_find_phys(struct r10conf *conf, struct r10bio *r10bio)
{
struct geom *geo = &conf->geo;
if (conf->reshape_progress != MaxSector &&
((r10bio->sector >= conf->reshape_progress) !=
conf->mddev->reshape_backwards)) {
set_bit(R10BIO_Previous, &r10bio->state);
geo = &conf->prev;
} else
clear_bit(R10BIO_Previous, &r10bio->state);
__raid10_find_phys(geo, r10bio);
}
static sector_t raid10_find_virt(struct r10conf *conf, sector_t sector, int dev)
{
sector_t offset, chunk, vchunk;
/* Never use conf->prev as this is only called during resync
* or recovery, so reshape isn't happening
*/
struct geom *geo = &conf->geo;
int far_set_start = (dev / geo->far_set_size) * geo->far_set_size;
int far_set_size = geo->far_set_size;
int last_far_set_start;
if (geo->raid_disks % geo->far_set_size) {
last_far_set_start = (geo->raid_disks / geo->far_set_size) - 1;
last_far_set_start *= geo->far_set_size;
if (dev >= last_far_set_start) {
far_set_size = geo->far_set_size;
far_set_size += (geo->raid_disks % geo->far_set_size);
far_set_start = last_far_set_start;
}
}
offset = sector & geo->chunk_mask;
if (geo->far_offset) {
int fc;
chunk = sector >> geo->chunk_shift;
fc = sector_div(chunk, geo->far_copies);
dev -= fc * geo->near_copies;
if (dev < far_set_start)
dev += far_set_size;
} else {
while (sector >= geo->stride) {
sector -= geo->stride;
if (dev < (geo->near_copies + far_set_start))
dev += far_set_size - geo->near_copies;
else
dev -= geo->near_copies;
}
chunk = sector >> geo->chunk_shift;
}
vchunk = chunk * geo->raid_disks + dev;
sector_div(vchunk, geo->near_copies);
return (vchunk << geo->chunk_shift) + offset;
}
/*
* This routine returns the disk from which the requested read should
* be done. There is a per-array 'next expected sequential IO' sector
* number - if this matches on the next IO then we use the last disk.
* There is also a per-disk 'last know head position' sector that is
* maintained from IRQ contexts, both the normal and the resync IO
* completion handlers update this position correctly. If there is no
* perfect sequential match then we pick the disk whose head is closest.
*
* If there are 2 mirrors in the same 2 devices, performance degrades
* because position is mirror, not device based.
*
* The rdev for the device selected will have nr_pending incremented.
*/
/*
* FIXME: possibly should rethink readbalancing and do it differently
* depending on near_copies / far_copies geometry.
*/
static struct md_rdev *read_balance(struct r10conf *conf,
struct r10bio *r10_bio,
int *max_sectors)
{
const sector_t this_sector = r10_bio->sector;
int disk, slot;
int sectors = r10_bio->sectors;
int best_good_sectors;
sector_t new_distance, best_dist;
struct md_rdev *best_dist_rdev, *best_pending_rdev, *rdev = NULL;
int do_balance;
int best_dist_slot, best_pending_slot;
bool has_nonrot_disk = false;
unsigned int min_pending;
struct geom *geo = &conf->geo;
raid10_find_phys(conf, r10_bio);
rcu_read_lock();
best_dist_slot = -1;
min_pending = UINT_MAX;
best_dist_rdev = NULL;
best_pending_rdev = NULL;
best_dist = MaxSector;
best_good_sectors = 0;
do_balance = 1;
clear_bit(R10BIO_FailFast, &r10_bio->state);
/*
* Check if we can balance. We can balance on the whole
* device if no resync is going on (recovery is ok), or below
* the resync window. We take the first readable disk when
* above the resync window.
*/
if ((conf->mddev->recovery_cp < MaxSector
&& (this_sector + sectors >= conf->next_resync)) ||
(mddev_is_clustered(conf->mddev) &&
md_cluster_ops->area_resyncing(conf->mddev, READ, this_sector,
this_sector + sectors)))
do_balance = 0;
for (slot = 0; slot < conf->copies ; slot++) {
sector_t first_bad;
int bad_sectors;
sector_t dev_sector;
unsigned int pending;
bool nonrot;
if (r10_bio->devs[slot].bio == IO_BLOCKED)
continue;
disk = r10_bio->devs[slot].devnum;
rdev = rcu_dereference(conf->mirrors[disk].replacement);
if (rdev == NULL || test_bit(Faulty, &rdev->flags) ||
r10_bio->devs[slot].addr + sectors >
rdev->recovery_offset) {
/*
* Read replacement first to prevent reading both rdev
* and replacement as NULL during replacement replace
* rdev.
*/
smp_mb();
rdev = rcu_dereference(conf->mirrors[disk].rdev);
}
if (rdev == NULL ||
test_bit(Faulty, &rdev->flags))
continue;
if (!test_bit(In_sync, &rdev->flags) &&
r10_bio->devs[slot].addr + sectors > rdev->recovery_offset)
continue;
dev_sector = r10_bio->devs[slot].addr;
if (is_badblock(rdev, dev_sector, sectors,
&first_bad, &bad_sectors)) {
if (best_dist < MaxSector)
/* Already have a better slot */
continue;
if (first_bad <= dev_sector) {
/* Cannot read here. If this is the
* 'primary' device, then we must not read
* beyond 'bad_sectors' from another device.
*/
bad_sectors -= (dev_sector - first_bad);
if (!do_balance && sectors > bad_sectors)
sectors = bad_sectors;
if (best_good_sectors > sectors)
best_good_sectors = sectors;
} else {
sector_t good_sectors =
first_bad - dev_sector;
if (good_sectors > best_good_sectors) {
best_good_sectors = good_sectors;
best_dist_slot = slot;
best_dist_rdev = rdev;
}
if (!do_balance)
/* Must read from here */
break;
}
continue;
} else
best_good_sectors = sectors;
if (!do_balance)
break;
nonrot = bdev_nonrot(rdev->bdev);
has_nonrot_disk |= nonrot;
pending = atomic_read(&rdev->nr_pending);
if (min_pending > pending && nonrot) {
min_pending = pending;
best_pending_slot = slot;
best_pending_rdev = rdev;
}
if (best_dist_slot >= 0)
/* At least 2 disks to choose from so failfast is OK */
set_bit(R10BIO_FailFast, &r10_bio->state);
/* This optimisation is debatable, and completely destroys
* sequential read speed for 'far copies' arrays. So only
* keep it for 'near' arrays, and review those later.
*/
if (geo->near_copies > 1 && !pending)
new_distance = 0;
/* for far > 1 always use the lowest address */
else if (geo->far_copies > 1)
new_distance = r10_bio->devs[slot].addr;
else
new_distance = abs(r10_bio->devs[slot].addr -
conf->mirrors[disk].head_position);
if (new_distance < best_dist) {
best_dist = new_distance;
best_dist_slot = slot;
best_dist_rdev = rdev;
}
}
if (slot >= conf->copies) {
if (has_nonrot_disk) {
slot = best_pending_slot;
rdev = best_pending_rdev;
} else {
slot = best_dist_slot;
rdev = best_dist_rdev;
}
}
if (slot >= 0) {
atomic_inc(&rdev->nr_pending);
r10_bio->read_slot = slot;
} else
rdev = NULL;
rcu_read_unlock();
*max_sectors = best_good_sectors;
return rdev;
}
static void flush_pending_writes(struct r10conf *conf)
{
/* Any writes that have been queued but are awaiting
* bitmap updates get flushed here.
*/
spin_lock_irq(&conf->device_lock);
if (conf->pending_bio_list.head) {
struct blk_plug plug;
struct bio *bio;
bio = bio_list_get(&conf->pending_bio_list);
spin_unlock_irq(&conf->device_lock);
/*
* As this is called in a wait_event() loop (see freeze_array),
* current->state might be TASK_UNINTERRUPTIBLE which will
* cause a warning when we prepare to wait again. As it is
* rare that this path is taken, it is perfectly safe to force
* us to go around the wait_event() loop again, so the warning
* is a false-positive. Silence the warning by resetting
* thread state
*/
__set_current_state(TASK_RUNNING);
blk_start_plug(&plug);
raid1_prepare_flush_writes(conf->mddev->bitmap);
wake_up(&conf->wait_barrier);
while (bio) { /* submit pending writes */
struct bio *next = bio->bi_next;
raid1_submit_write(bio);
bio = next;
cond_resched();
}
blk_finish_plug(&plug);
} else
spin_unlock_irq(&conf->device_lock);
}
/* Barriers....
* Sometimes we need to suspend IO while we do something else,
* either some resync/recovery, or reconfigure the array.
* To do this we raise a 'barrier'.
* The 'barrier' is a counter that can be raised multiple times
* to count how many activities are happening which preclude
* normal IO.
* We can only raise the barrier if there is no pending IO.
* i.e. if nr_pending == 0.
* We choose only to raise the barrier if no-one is waiting for the
* barrier to go down. This means that as soon as an IO request
* is ready, no other operations which require a barrier will start
* until the IO request has had a chance.
*
* So: regular IO calls 'wait_barrier'. When that returns there
* is no backgroup IO happening, It must arrange to call
* allow_barrier when it has finished its IO.
* backgroup IO calls must call raise_barrier. Once that returns
* there is no normal IO happeing. It must arrange to call
* lower_barrier when the particular background IO completes.
*/
static void raise_barrier(struct r10conf *conf, int force)
{
write_seqlock_irq(&conf->resync_lock);
if (WARN_ON_ONCE(force && !conf->barrier))
force = false;
/* Wait until no block IO is waiting (unless 'force') */
wait_event_barrier(conf, force || !conf->nr_waiting);
/* block any new IO from starting */
WRITE_ONCE(conf->barrier, conf->barrier + 1);
/* Now wait for all pending IO to complete */
wait_event_barrier(conf, !atomic_read(&conf->nr_pending) &&
conf->barrier < RESYNC_DEPTH);
write_sequnlock_irq(&conf->resync_lock);
}
static void lower_barrier(struct r10conf *conf)
{
unsigned long flags;
write_seqlock_irqsave(&conf->resync_lock, flags);
WRITE_ONCE(conf->barrier, conf->barrier - 1);
write_sequnlock_irqrestore(&conf->resync_lock, flags);
wake_up(&conf->wait_barrier);
}
static bool stop_waiting_barrier(struct r10conf *conf)
{
struct bio_list *bio_list = current->bio_list;
struct md_thread *thread;
/* barrier is dropped */
if (!conf->barrier)
return true;
/*
* If there are already pending requests (preventing the barrier from
* rising completely), and the pre-process bio queue isn't empty, then
* don't wait, as we need to empty that queue to get the nr_pending
* count down.
*/
if (atomic_read(&conf->nr_pending) && bio_list &&
(!bio_list_empty(&bio_list[0]) || !bio_list_empty(&bio_list[1])))
return true;
/* daemon thread must exist while handling io */
thread = rcu_dereference_protected(conf->mddev->thread, true);
/*
* move on if io is issued from raid10d(), nr_pending is not released
* from original io(see handle_read_error()). All raise barrier is
* blocked until this io is done.
*/
if (thread->tsk == current) {
WARN_ON_ONCE(atomic_read(&conf->nr_pending) == 0);
return true;
}
return false;
}
static bool wait_barrier_nolock(struct r10conf *conf)
{
unsigned int seq = read_seqbegin(&conf->resync_lock);
if (READ_ONCE(conf->barrier))
return false;
atomic_inc(&conf->nr_pending);
if (!read_seqretry(&conf->resync_lock, seq))
return true;
if (atomic_dec_and_test(&conf->nr_pending))
wake_up_barrier(conf);
return false;
}
static bool wait_barrier(struct r10conf *conf, bool nowait)
{
bool ret = true;
if (wait_barrier_nolock(conf))
return true;
write_seqlock_irq(&conf->resync_lock);
if (conf->barrier) {
/* Return false when nowait flag is set */
if (nowait) {
ret = false;
} else {
conf->nr_waiting++;
raid10_log(conf->mddev, "wait barrier");
wait_event_barrier(conf, stop_waiting_barrier(conf));
conf->nr_waiting--;
}
if (!conf->nr_waiting)
wake_up(&conf->wait_barrier);
}
/* Only increment nr_pending when we wait */
if (ret)
atomic_inc(&conf->nr_pending);
write_sequnlock_irq(&conf->resync_lock);
return ret;
}
static void allow_barrier(struct r10conf *conf)
{
if ((atomic_dec_and_test(&conf->nr_pending)) ||
(conf->array_freeze_pending))
wake_up_barrier(conf);
}
static void freeze_array(struct r10conf *conf, int extra)
{
/* stop syncio and normal IO and wait for everything to
* go quiet.
* We increment barrier and nr_waiting, and then
* wait until nr_pending match nr_queued+extra
* This is called in the context of one normal IO request
* that has failed. Thus any sync request that might be pending
* will be blocked by nr_pending, and we need to wait for
* pending IO requests to complete or be queued for re-try.
* Thus the number queued (nr_queued) plus this request (extra)
* must match the number of pending IOs (nr_pending) before
* we continue.
*/
write_seqlock_irq(&conf->resync_lock);
conf->array_freeze_pending++;
WRITE_ONCE(conf->barrier, conf->barrier + 1);
conf->nr_waiting++;
wait_event_barrier_cmd(conf, atomic_read(&conf->nr_pending) ==
conf->nr_queued + extra, flush_pending_writes(conf));
conf->array_freeze_pending--;
write_sequnlock_irq(&conf->resync_lock);
}
static void unfreeze_array(struct r10conf *conf)
{
/* reverse the effect of the freeze */
write_seqlock_irq(&conf->resync_lock);
WRITE_ONCE(conf->barrier, conf->barrier - 1);
conf->nr_waiting--;
wake_up(&conf->wait_barrier);
write_sequnlock_irq(&conf->resync_lock);
}
static sector_t choose_data_offset(struct r10bio *r10_bio,
struct md_rdev *rdev)
{
if (!test_bit(MD_RECOVERY_RESHAPE, &rdev->mddev->recovery) ||
test_bit(R10BIO_Previous, &r10_bio->state))
return rdev->data_offset;
else
return rdev->new_data_offset;
}
static void raid10_unplug(struct blk_plug_cb *cb, bool from_schedule)
{
struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb, cb);
struct mddev *mddev = plug->cb.data;
struct r10conf *conf = mddev->private;
struct bio *bio;
if (from_schedule) {
spin_lock_irq(&conf->device_lock);
bio_list_merge(&conf->pending_bio_list, &plug->pending);
spin_unlock_irq(&conf->device_lock);
wake_up_barrier(conf);
md_wakeup_thread(mddev->thread);
kfree(plug);
return;
}
/* we aren't scheduling, so we can do the write-out directly. */
bio = bio_list_get(&plug->pending);
raid1_prepare_flush_writes(mddev->bitmap);
wake_up_barrier(conf);
while (bio) { /* submit pending writes */
struct bio *next = bio->bi_next;
raid1_submit_write(bio);
bio = next;
cond_resched();
}
kfree(plug);
}
/*
* 1. Register the new request and wait if the reconstruction thread has put
* up a bar for new requests. Continue immediately if no resync is active
* currently.
* 2. If IO spans the reshape position. Need to wait for reshape to pass.
*/
static bool regular_request_wait(struct mddev *mddev, struct r10conf *conf,
struct bio *bio, sector_t sectors)
{
/* Bail out if REQ_NOWAIT is set for the bio */
if (!wait_barrier(conf, bio->bi_opf & REQ_NOWAIT)) {
bio_wouldblock_error(bio);
return false;
}
while (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
bio->bi_iter.bi_sector < conf->reshape_progress &&
bio->bi_iter.bi_sector + sectors > conf->reshape_progress) {
allow_barrier(conf);
if (bio->bi_opf & REQ_NOWAIT) {
bio_wouldblock_error(bio);
return false;
}
raid10_log(conf->mddev, "wait reshape");
wait_event(conf->wait_barrier,
conf->reshape_progress <= bio->bi_iter.bi_sector ||
conf->reshape_progress >= bio->bi_iter.bi_sector +
sectors);
wait_barrier(conf, false);
}
return true;
}
static void raid10_read_request(struct mddev *mddev, struct bio *bio,
struct r10bio *r10_bio, bool io_accounting)
{
struct r10conf *conf = mddev->private;
struct bio *read_bio;
const enum req_op op = bio_op(bio);
const blk_opf_t do_sync = bio->bi_opf & REQ_SYNC;
int max_sectors;
struct md_rdev *rdev;
char b[BDEVNAME_SIZE];
int slot = r10_bio->read_slot;
struct md_rdev *err_rdev = NULL;
gfp_t gfp = GFP_NOIO;
if (slot >= 0 && r10_bio->devs[slot].rdev) {
/*
* This is an error retry, but we cannot
* safely dereference the rdev in the r10_bio,
* we must use the one in conf.
* If it has already been disconnected (unlikely)
* we lose the device name in error messages.
*/
int disk;
/*
* As we are blocking raid10, it is a little safer to
* use __GFP_HIGH.
*/
gfp = GFP_NOIO | __GFP_HIGH;
rcu_read_lock();
disk = r10_bio->devs[slot].devnum;
err_rdev = rcu_dereference(conf->mirrors[disk].rdev);
if (err_rdev)
snprintf(b, sizeof(b), "%pg", err_rdev->bdev);
else {
strcpy(b, "???");
/* This never gets dereferenced */
err_rdev = r10_bio->devs[slot].rdev;
}
rcu_read_unlock();
}
if (!regular_request_wait(mddev, conf, bio, r10_bio->sectors))
return;
rdev = read_balance(conf, r10_bio, &max_sectors);
if (!rdev) {
if (err_rdev) {
pr_crit_ratelimited("md/raid10:%s: %s: unrecoverable I/O read error for block %llu\n",
mdname(mddev), b,
(unsigned long long)r10_bio->sector);
}
raid_end_bio_io(r10_bio);
return;
}
if (err_rdev)
pr_err_ratelimited("md/raid10:%s: %pg: redirecting sector %llu to another mirror\n",
mdname(mddev),
rdev->bdev,
(unsigned long long)r10_bio->sector);
if (max_sectors < bio_sectors(bio)) {
struct bio *split = bio_split(bio, max_sectors,
gfp, &conf->bio_split);
bio_chain(split, bio);
allow_barrier(conf);
submit_bio_noacct(bio);
wait_barrier(conf, false);
bio = split;
r10_bio->master_bio = bio;
r10_bio->sectors = max_sectors;
}
slot = r10_bio->read_slot;
if (io_accounting) {
md_account_bio(mddev, &bio);
r10_bio->master_bio = bio;
}
read_bio = bio_alloc_clone(rdev->bdev, bio, gfp, &mddev->bio_set);
r10_bio->devs[slot].bio = read_bio;
r10_bio->devs[slot].rdev = rdev;
read_bio->bi_iter.bi_sector = r10_bio->devs[slot].addr +
choose_data_offset(r10_bio, rdev);
read_bio->bi_end_io = raid10_end_read_request;
read_bio->bi_opf = op | do_sync;
if (test_bit(FailFast, &rdev->flags) &&
test_bit(R10BIO_FailFast, &r10_bio->state))
read_bio->bi_opf |= MD_FAILFAST;
read_bio->bi_private = r10_bio;
if (mddev->gendisk)
trace_block_bio_remap(read_bio, disk_devt(mddev->gendisk),
r10_bio->sector);
submit_bio_noacct(read_bio);
return;
}
static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio,
struct bio *bio, bool replacement,
int n_copy)
{
const enum req_op op = bio_op(bio);
const blk_opf_t do_sync = bio->bi_opf & REQ_SYNC;
const blk_opf_t do_fua = bio->bi_opf & REQ_FUA;
unsigned long flags;
struct r10conf *conf = mddev->private;
struct md_rdev *rdev;
int devnum = r10_bio->devs[n_copy].devnum;
struct bio *mbio;
if (replacement) {
rdev = conf->mirrors[devnum].replacement;
if (rdev == NULL) {
/* Replacement just got moved to main 'rdev' */
smp_mb();
rdev = conf->mirrors[devnum].rdev;
}
} else
rdev = conf->mirrors[devnum].rdev;
mbio = bio_alloc_clone(rdev->bdev, bio, GFP_NOIO, &mddev->bio_set);
if (replacement)
r10_bio->devs[n_copy].repl_bio = mbio;
else
r10_bio->devs[n_copy].bio = mbio;
mbio->bi_iter.bi_sector = (r10_bio->devs[n_copy].addr +
choose_data_offset(r10_bio, rdev));
mbio->bi_end_io = raid10_end_write_request;
mbio->bi_opf = op | do_sync | do_fua;
if (!replacement && test_bit(FailFast,
&conf->mirrors[devnum].rdev->flags)
&& enough(conf, devnum))
mbio->bi_opf |= MD_FAILFAST;
mbio->bi_private = r10_bio;
if (conf->mddev->gendisk)
trace_block_bio_remap(mbio, disk_devt(conf->mddev->gendisk),
r10_bio->sector);
/* flush_pending_writes() needs access to the rdev so...*/
mbio->bi_bdev = (void *)rdev;
atomic_inc(&r10_bio->remaining);
if (!raid1_add_bio_to_plug(mddev, mbio, raid10_unplug, conf->copies)) {
spin_lock_irqsave(&conf->device_lock, flags);
bio_list_add(&conf->pending_bio_list, mbio);
spin_unlock_irqrestore(&conf->device_lock, flags);
md_wakeup_thread(mddev->thread);
}
}
static struct md_rdev *dereference_rdev_and_rrdev(struct raid10_info *mirror,
struct md_rdev **prrdev)
{
struct md_rdev *rdev, *rrdev;
rrdev = rcu_dereference(mirror->replacement);
/*
* Read replacement first to prevent reading both rdev and
* replacement as NULL during replacement replace rdev.
*/
smp_mb();
rdev = rcu_dereference(mirror->rdev);
if (rdev == rrdev)
rrdev = NULL;
*prrdev = rrdev;
return rdev;
}
static void wait_blocked_dev(struct mddev *mddev, struct r10bio *r10_bio)
{
int i;
struct r10conf *conf = mddev->private;
struct md_rdev *blocked_rdev;
retry_wait:
blocked_rdev = NULL;
rcu_read_lock();
for (i = 0; i < conf->copies; i++) {
struct md_rdev *rdev, *rrdev;
rdev = dereference_rdev_and_rrdev(&conf->mirrors[i], &rrdev);
if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
atomic_inc(&rdev->nr_pending);
blocked_rdev = rdev;
break;
}
if (rrdev && unlikely(test_bit(Blocked, &rrdev->flags))) {
atomic_inc(&rrdev->nr_pending);
blocked_rdev = rrdev;
break;
}
if (rdev && test_bit(WriteErrorSeen, &rdev->flags)) {
sector_t first_bad;
sector_t dev_sector = r10_bio->devs[i].addr;
int bad_sectors;
int is_bad;
/*
* Discard request doesn't care the write result
* so it doesn't need to wait blocked disk here.
*/
if (!r10_bio->sectors)
continue;
is_bad = is_badblock(rdev, dev_sector, r10_bio->sectors,
&first_bad, &bad_sectors);
if (is_bad < 0) {
/*
* Mustn't write here until the bad block
* is acknowledged
*/
atomic_inc(&rdev->nr_pending);
set_bit(BlockedBadBlocks, &rdev->flags);
blocked_rdev = rdev;
break;
}
}
}
rcu_read_unlock();
if (unlikely(blocked_rdev)) {
/* Have to wait for this device to get unblocked, then retry */
allow_barrier(conf);
raid10_log(conf->mddev, "%s wait rdev %d blocked",
__func__, blocked_rdev->raid_disk);
md_wait_for_blocked_rdev(blocked_rdev, mddev);
wait_barrier(conf, false);
goto retry_wait;
}
}
static void raid10_write_request(struct mddev *mddev, struct bio *bio,
struct r10bio *r10_bio)
{
struct r10conf *conf = mddev->private;
int i;
sector_t sectors;
int max_sectors;
if ((mddev_is_clustered(mddev) &&
md_cluster_ops->area_resyncing(mddev, WRITE,
bio->bi_iter.bi_sector,
bio_end_sector(bio)))) {
DEFINE_WAIT(w);
/* Bail out if REQ_NOWAIT is set for the bio */
if (bio->bi_opf & REQ_NOWAIT) {
bio_wouldblock_error(bio);
return;
}
for (;;) {
prepare_to_wait(&conf->wait_barrier,
&w, TASK_IDLE);
if (!md_cluster_ops->area_resyncing(mddev, WRITE,
bio->bi_iter.bi_sector, bio_end_sector(bio)))
break;
schedule();
}
finish_wait(&conf->wait_barrier, &w);
}
sectors = r10_bio->sectors;
if (!regular_request_wait(mddev, conf, bio, sectors))
return;
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
(mddev->reshape_backwards
? (bio->bi_iter.bi_sector < conf->reshape_safe &&
bio->bi_iter.bi_sector + sectors > conf->reshape_progress)
: (bio->bi_iter.bi_sector + sectors > conf->reshape_safe &&
bio->bi_iter.bi_sector < conf->reshape_progress))) {
/* Need to update reshape_position in metadata */
mddev->reshape_position = conf->reshape_progress;
set_mask_bits(&mddev->sb_flags, 0,
BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
md_wakeup_thread(mddev->thread);
if (bio->bi_opf & REQ_NOWAIT) {
allow_barrier(conf);
bio_wouldblock_error(bio);
return;
}
raid10_log(conf->mddev, "wait reshape metadata");
wait_event(mddev->sb_wait,
!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
conf->reshape_safe = mddev->reshape_position;
}
/* first select target devices under rcu_lock and
* inc refcount on their rdev. Record them by setting
* bios[x] to bio
* If there are known/acknowledged bad blocks on any device
* on which we have seen a write error, we want to avoid
* writing to those blocks. This potentially requires several
* writes to write around the bad blocks. Each set of writes
* gets its own r10_bio with a set of bios attached.
*/
r10_bio->read_slot = -1; /* make sure repl_bio gets freed */
raid10_find_phys(conf, r10_bio);
wait_blocked_dev(mddev, r10_bio);
rcu_read_lock();
max_sectors = r10_bio->sectors;
for (i = 0; i < conf->copies; i++) {
int d = r10_bio->devs[i].devnum;
struct md_rdev *rdev, *rrdev;
rdev = dereference_rdev_and_rrdev(&conf->mirrors[d], &rrdev);
if (rdev && (test_bit(Faulty, &rdev->flags)))
rdev = NULL;
if (rrdev && (test_bit(Faulty, &rrdev->flags)))
rrdev = NULL;
r10_bio->devs[i].bio = NULL;
r10_bio->devs[i].repl_bio = NULL;
if (!rdev && !rrdev) {
set_bit(R10BIO_Degraded, &r10_bio->state);
continue;
}
if (rdev && test_bit(WriteErrorSeen, &rdev->flags)) {
sector_t first_bad;
sector_t dev_sector = r10_bio->devs[i].addr;
int bad_sectors;
int is_bad;
is_bad = is_badblock(rdev, dev_sector, max_sectors,
&first_bad, &bad_sectors);
if (is_bad && first_bad <= dev_sector) {
/* Cannot write here at all */
bad_sectors -= (dev_sector - first_bad);
if (bad_sectors < max_sectors)
/* Mustn't write more than bad_sectors
* to other devices yet
*/
max_sectors = bad_sectors;
/* We don't set R10BIO_Degraded as that
* only applies if the disk is missing,
* so it might be re-added, and we want to
* know to recover this chunk.
* In this case the device is here, and the
* fact that this chunk is not in-sync is
* recorded in the bad block log.
*/
continue;
}
if (is_bad) {
int good_sectors = first_bad - dev_sector;
if (good_sectors < max_sectors)
max_sectors = good_sectors;
}
}
if (rdev) {
r10_bio->devs[i].bio = bio;
atomic_inc(&rdev->nr_pending);
}
if (rrdev) {
r10_bio->devs[i].repl_bio = bio;
atomic_inc(&rrdev->nr_pending);
}
}
rcu_read_unlock();
if (max_sectors < r10_bio->sectors)
r10_bio->sectors = max_sectors;
if (r10_bio->sectors < bio_sectors(bio)) {
struct bio *split = bio_split(bio, r10_bio->sectors,
GFP_NOIO, &conf->bio_split);
bio_chain(split, bio);
allow_barrier(conf);
submit_bio_noacct(bio);
wait_barrier(conf, false);
bio = split;
r10_bio->master_bio = bio;
}
md_account_bio(mddev, &bio);
r10_bio->master_bio = bio;
atomic_set(&r10_bio->remaining, 1);
md_bitmap_startwrite(mddev->bitmap, r10_bio->sector, r10_bio->sectors, 0);
for (i = 0; i < conf->copies; i++) {
if (r10_bio->devs[i].bio)
raid10_write_one_disk(mddev, r10_bio, bio, false, i);
if (r10_bio->devs[i].repl_bio)
raid10_write_one_disk(mddev, r10_bio, bio, true, i);
}
one_write_done(r10_bio);
}
static void __make_request(struct mddev *mddev, struct bio *bio, int sectors)
{
struct r10conf *conf = mddev->private;
struct r10bio *r10_bio;
r10_bio = mempool_alloc(&conf->r10bio_pool, GFP_NOIO);
r10_bio->master_bio = bio;
r10_bio->sectors = sectors;
r10_bio->mddev = mddev;
r10_bio->sector = bio->bi_iter.bi_sector;
r10_bio->state = 0;
r10_bio->read_slot = -1;
memset(r10_bio->devs, 0, sizeof(r10_bio->devs[0]) *
conf->geo.raid_disks);
if (bio_data_dir(bio) == READ)
raid10_read_request(mddev, bio, r10_bio, true);
else
raid10_write_request(mddev, bio, r10_bio);
}
static void raid_end_discard_bio(struct r10bio *r10bio)
{
struct r10conf *conf = r10bio->mddev->private;
struct r10bio *first_r10bio;
while (atomic_dec_and_test(&r10bio->remaining)) {
allow_barrier(conf);
if (!test_bit(R10BIO_Discard, &r10bio->state)) {
first_r10bio = (struct r10bio *)r10bio->master_bio;
free_r10bio(r10bio);
r10bio = first_r10bio;
} else {
md_write_end(r10bio->mddev);
bio_endio(r10bio->master_bio);
free_r10bio(r10bio);
break;
}
}
}
static void raid10_end_discard_request(struct bio *bio)
{
struct r10bio *r10_bio = bio->bi_private;
struct r10conf *conf = r10_bio->mddev->private;
struct md_rdev *rdev = NULL;
int dev;
int slot, repl;
/*
* We don't care the return value of discard bio
*/
if (!test_bit(R10BIO_Uptodate, &r10_bio->state))
set_bit(R10BIO_Uptodate, &r10_bio->state);
dev = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
if (repl)
rdev = conf->mirrors[dev].replacement;
if (!rdev) {
/*
* raid10_remove_disk uses smp_mb to make sure rdev is set to
* replacement before setting replacement to NULL. It can read
* rdev first without barrier protect even replacement is NULL
*/
smp_rmb();
rdev = conf->mirrors[dev].rdev;
}
raid_end_discard_bio(r10_bio);
rdev_dec_pending(rdev, conf->mddev);
}
/*
* There are some limitations to handle discard bio
* 1st, the discard size is bigger than stripe_size*2.
* 2st, if the discard bio spans reshape progress, we use the old way to
* handle discard bio
*/
static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
{
struct r10conf *conf = mddev->private;
struct geom *geo = &conf->geo;
int far_copies = geo->far_copies;
bool first_copy = true;
struct r10bio *r10_bio, *first_r10bio;
struct bio *split;
int disk;
sector_t chunk;
unsigned int stripe_size;
unsigned int stripe_data_disks;
sector_t split_size;
sector_t bio_start, bio_end;
sector_t first_stripe_index, last_stripe_index;
sector_t start_disk_offset;
unsigned int start_disk_index;
sector_t end_disk_offset;
unsigned int end_disk_index;
unsigned int remainder;
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
return -EAGAIN;
if (WARN_ON_ONCE(bio->bi_opf & REQ_NOWAIT)) {
bio_wouldblock_error(bio);
return 0;
}
wait_barrier(conf, false);
/*
* Check reshape again to avoid reshape happens after checking
* MD_RECOVERY_RESHAPE and before wait_barrier
*/
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
goto out;
if (geo->near_copies)
stripe_data_disks = geo->raid_disks / geo->near_copies +
geo->raid_disks % geo->near_copies;
else
stripe_data_disks = geo->raid_disks;
stripe_size = stripe_data_disks << geo->chunk_shift;
bio_start = bio->bi_iter.bi_sector;
bio_end = bio_end_sector(bio);
/*
* Maybe one discard bio is smaller than strip size or across one
* stripe and discard region is larger than one stripe size. For far
* offset layout, if the discard region is not aligned with stripe
* size, there is hole when we submit discard bio to member disk.
* For simplicity, we only handle discard bio which discard region
* is bigger than stripe_size * 2
*/
if (bio_sectors(bio) < stripe_size*2)
goto out;
/*
* Keep bio aligned with strip size.
*/
div_u64_rem(bio_start, stripe_size, &remainder);
if (remainder) {
split_size = stripe_size - remainder;
split = bio_split(bio, split_size, GFP_NOIO, &conf->bio_split);
bio_chain(split, bio);
allow_barrier(conf);
/* Resend the fist split part */
submit_bio_noacct(split);
wait_barrier(conf, false);
}
div_u64_rem(bio_end, stripe_size, &remainder);
if (remainder) {
split_size = bio_sectors(bio) - remainder;
split = bio_split(bio, split_size, GFP_NOIO, &conf->bio_split);
bio_chain(split, bio);
allow_barrier(conf);
/* Resend the second split part */
submit_bio_noacct(bio);
bio = split;
wait_barrier(conf, false);
}
bio_start = bio->bi_iter.bi_sector;
bio_end = bio_end_sector(bio);
/*
* Raid10 uses chunk as the unit to store data. It's similar like raid0.
* One stripe contains the chunks from all member disk (one chunk from
* one disk at the same HBA address). For layout detail, see 'man md 4'
*/
chunk = bio_start >> geo->chunk_shift;
chunk *= geo->near_copies;
first_stripe_index = chunk;
start_disk_index = sector_div(first_stripe_index, geo->raid_disks);
if (geo->far_offset)
first_stripe_index *= geo->far_copies;
start_disk_offset = (bio_start & geo->chunk_mask) +
(first_stripe_index << geo->chunk_shift);
chunk = bio_end >> geo->chunk_shift;
chunk *= geo->near_copies;
last_stripe_index = chunk;
end_disk_index = sector_div(last_stripe_index, geo->raid_disks);
if (geo->far_offset)
last_stripe_index *= geo->far_copies;
end_disk_offset = (bio_end & geo->chunk_mask) +
(last_stripe_index << geo->chunk_shift);
retry_discard:
r10_bio = mempool_alloc(&conf->r10bio_pool, GFP_NOIO);
r10_bio->mddev = mddev;
r10_bio->state = 0;
r10_bio->sectors = 0;
memset(r10_bio->devs, 0, sizeof(r10_bio->devs[0]) * geo->raid_disks);
wait_blocked_dev(mddev, r10_bio);
/*
* For far layout it needs more than one r10bio to cover all regions.
* Inspired by raid10_sync_request, we can use the first r10bio->master_bio
* to record the discard bio. Other r10bio->master_bio record the first
* r10bio. The first r10bio only release after all other r10bios finish.
* The discard bio returns only first r10bio finishes
*/
if (first_copy) {
r10_bio->master_bio = bio;
set_bit(R10BIO_Discard, &r10_bio->state);
first_copy = false;
first_r10bio = r10_bio;
} else
r10_bio->master_bio = (struct bio *)first_r10bio;
/*
* first select target devices under rcu_lock and
* inc refcount on their rdev. Record them by setting
* bios[x] to bio
*/
rcu_read_lock();
for (disk = 0; disk < geo->raid_disks; disk++) {
struct md_rdev *rdev, *rrdev;
rdev = dereference_rdev_and_rrdev(&conf->mirrors[disk], &rrdev);
r10_bio->devs[disk].bio = NULL;
r10_bio->devs[disk].repl_bio = NULL;
if (rdev && (test_bit(Faulty, &rdev->flags)))
rdev = NULL;
if (rrdev && (test_bit(Faulty, &rrdev->flags)))
rrdev = NULL;
if (!rdev && !rrdev)
continue;
if (rdev) {
r10_bio->devs[disk].bio = bio;
atomic_inc(&rdev->nr_pending);
}
if (rrdev) {
r10_bio->devs[disk].repl_bio = bio;
atomic_inc(&rrdev->nr_pending);
}
}
rcu_read_unlock();
atomic_set(&r10_bio->remaining, 1);
for (disk = 0; disk < geo->raid_disks; disk++) {
sector_t dev_start, dev_end;
struct bio *mbio, *rbio = NULL;
/*
* Now start to calculate the start and end address for each disk.
* The space between dev_start and dev_end is the discard region.
*
* For dev_start, it needs to consider three conditions:
* 1st, the disk is before start_disk, you can imagine the disk in
* the next stripe. So the dev_start is the start address of next
* stripe.
* 2st, the disk is after start_disk, it means the disk is at the
* same stripe of first disk
* 3st, the first disk itself, we can use start_disk_offset directly
*/
if (disk < start_disk_index)
dev_start = (first_stripe_index + 1) * mddev->chunk_sectors;
else if (disk > start_disk_index)
dev_start = first_stripe_index * mddev->chunk_sectors;
else
dev_start = start_disk_offset;
if (disk < end_disk_index)
dev_end = (last_stripe_index + 1) * mddev->chunk_sectors;
else if (disk > end_disk_index)
dev_end = last_stripe_index * mddev->chunk_sectors;
else
dev_end = end_disk_offset;
/*
* It only handles discard bio which size is >= stripe size, so
* dev_end > dev_start all the time.
* It doesn't need to use rcu lock to get rdev here. We already
* add rdev->nr_pending in the first loop.
*/
if (r10_bio->devs[disk].bio) {
struct md_rdev *rdev = conf->mirrors[disk].rdev;
mbio = bio_alloc_clone(bio->bi_bdev, bio, GFP_NOIO,
&mddev->bio_set);
mbio->bi_end_io = raid10_end_discard_request;
mbio->bi_private = r10_bio;
r10_bio->devs[disk].bio = mbio;
r10_bio->devs[disk].devnum = disk;
atomic_inc(&r10_bio->remaining);
md_submit_discard_bio(mddev, rdev, mbio,
dev_start + choose_data_offset(r10_bio, rdev),
dev_end - dev_start);
bio_endio(mbio);
}
if (r10_bio->devs[disk].repl_bio) {
struct md_rdev *rrdev = conf->mirrors[disk].replacement;
rbio = bio_alloc_clone(bio->bi_bdev, bio, GFP_NOIO,
&mddev->bio_set);
rbio->bi_end_io = raid10_end_discard_request;
rbio->bi_private = r10_bio;
r10_bio->devs[disk].repl_bio = rbio;
r10_bio->devs[disk].devnum = disk;
atomic_inc(&r10_bio->remaining);
md_submit_discard_bio(mddev, rrdev, rbio,
dev_start + choose_data_offset(r10_bio, rrdev),
dev_end - dev_start);
bio_endio(rbio);
}
}
if (!geo->far_offset && --far_copies) {
first_stripe_index += geo->stride >> geo->chunk_shift;
start_disk_offset += geo->stride;
last_stripe_index += geo->stride >> geo->chunk_shift;
end_disk_offset += geo->stride;
atomic_inc(&first_r10bio->remaining);
raid_end_discard_bio(r10_bio);
wait_barrier(conf, false);
goto retry_discard;
}
raid_end_discard_bio(r10_bio);
return 0;
out:
allow_barrier(conf);
return -EAGAIN;
}
static bool raid10_make_request(struct mddev *mddev, struct bio *bio)
{
struct r10conf *conf = mddev->private;
sector_t chunk_mask = (conf->geo.chunk_mask & conf->prev.chunk_mask);
int chunk_sects = chunk_mask + 1;
int sectors = bio_sectors(bio);
if (unlikely(bio->bi_opf & REQ_PREFLUSH)
&& md_flush_request(mddev, bio))
return true;
if (!md_write_start(mddev, bio))
return false;
if (unlikely(bio_op(bio) == REQ_OP_DISCARD))
if (!raid10_handle_discard(mddev, bio))
return true;
/*
* If this request crosses a chunk boundary, we need to split
* it.
*/
if (unlikely((bio->bi_iter.bi_sector & chunk_mask) +
sectors > chunk_sects
&& (conf->geo.near_copies < conf->geo.raid_disks
|| conf->prev.near_copies <
conf->prev.raid_disks)))
sectors = chunk_sects -
(bio->bi_iter.bi_sector &
(chunk_sects - 1));
__make_request(mddev, bio, sectors);
/* In case raid10d snuck in to freeze_array */
wake_up_barrier(conf);
return true;
}
static void raid10_status(struct seq_file *seq, struct mddev *mddev)
{
struct r10conf *conf = mddev->private;
int i;
if (conf->geo.near_copies < conf->geo.raid_disks)
seq_printf(seq, " %dK chunks", mddev->chunk_sectors / 2);
if (conf->geo.near_copies > 1)
seq_printf(seq, " %d near-copies", conf->geo.near_copies);
if (conf->geo.far_copies > 1) {
if (conf->geo.far_offset)
seq_printf(seq, " %d offset-copies", conf->geo.far_copies);
else
seq_printf(seq, " %d far-copies", conf->geo.far_copies);
if (conf->geo.far_set_size != conf->geo.raid_disks)
seq_printf(seq, " %d devices per set", conf->geo.far_set_size);
}
seq_printf(seq, " [%d/%d] [", conf->geo.raid_disks,
conf->geo.raid_disks - mddev->degraded);
rcu_read_lock();
for (i = 0; i < conf->geo.raid_disks; i++) {
struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
seq_printf(seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
}
rcu_read_unlock();
seq_printf(seq, "]");
}
/* check if there are enough drives for
* every block to appear on atleast one.
* Don't consider the device numbered 'ignore'
* as we might be about to remove it.
*/
static int _enough(struct r10conf *conf, int previous, int ignore)
{
int first = 0;
int has_enough = 0;
int disks, ncopies;
if (previous) {
disks = conf->prev.raid_disks;
ncopies = conf->prev.near_copies;
} else {
disks = conf->geo.raid_disks;
ncopies = conf->geo.near_copies;
}
rcu_read_lock();
do {
int n = conf->copies;
int cnt = 0;
int this = first;
while (n--) {
struct md_rdev *rdev;
if (this != ignore &&
(rdev = rcu_dereference(conf->mirrors[this].rdev)) &&
test_bit(In_sync, &rdev->flags))
cnt++;
this = (this+1) % disks;
}
if (cnt == 0)
goto out;
first = (first + ncopies) % disks;
} while (first != 0);
has_enough = 1;
out:
rcu_read_unlock();
return has_enough;
}
static int enough(struct r10conf *conf, int ignore)
{
/* when calling 'enough', both 'prev' and 'geo' must
* be stable.
* This is ensured if ->reconfig_mutex or ->device_lock
* is held.
*/
return _enough(conf, 0, ignore) &&
_enough(conf, 1, ignore);
}
/**
* raid10_error() - RAID10 error handler.
* @mddev: affected md device.
* @rdev: member device to fail.
*
* The routine acknowledges &rdev failure and determines new @mddev state.
* If it failed, then:
* - &MD_BROKEN flag is set in &mddev->flags.
* Otherwise, it must be degraded:
* - recovery is interrupted.
* - &mddev->degraded is bumped.
*
* @rdev is marked as &Faulty excluding case when array is failed and
* &mddev->fail_last_dev is off.
*/
static void raid10_error(struct mddev *mddev, struct md_rdev *rdev)
{
struct r10conf *conf = mddev->private;
unsigned long flags;
spin_lock_irqsave(&conf->device_lock, flags);
if (test_bit(In_sync, &rdev->flags) && !enough(conf, rdev->raid_disk)) {
set_bit(MD_BROKEN, &mddev->flags);
if (!mddev->fail_last_dev) {
spin_unlock_irqrestore(&conf->device_lock, flags);
return;
}
}
if (test_and_clear_bit(In_sync, &rdev->flags))
mddev->degraded++;
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
set_bit(Blocked, &rdev->flags);
set_bit(Faulty, &rdev->flags);
set_mask_bits(&mddev->sb_flags, 0,
BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
spin_unlock_irqrestore(&conf->device_lock, flags);
pr_crit("md/raid10:%s: Disk failure on %pg, disabling device.\n"
"md/raid10:%s: Operation continuing on %d devices.\n",
mdname(mddev), rdev->bdev,
mdname(mddev), conf->geo.raid_disks - mddev->degraded);
}
static void print_conf(struct r10conf *conf)
{
int i;
struct md_rdev *rdev;
pr_debug("RAID10 conf printout:\n");
if (!conf) {
pr_debug("(!conf)\n");
return;
}
pr_debug(" --- wd:%d rd:%d\n", conf->geo.raid_disks - conf->mddev->degraded,
conf->geo.raid_disks);
/* This is only called with ->reconfix_mutex held, so
* rcu protection of rdev is not needed */
for (i = 0; i < conf->geo.raid_disks; i++) {
rdev = conf->mirrors[i].rdev;
if (rdev)
pr_debug(" disk %d, wo:%d, o:%d, dev:%pg\n",
i, !test_bit(In_sync, &rdev->flags),
!test_bit(Faulty, &rdev->flags),
rdev->bdev);
}
}
static void close_sync(struct r10conf *conf)
{
wait_barrier(conf, false);
allow_barrier(conf);
mempool_exit(&conf->r10buf_pool);
}
static int raid10_spare_active(struct mddev *mddev)
{
int i;
struct r10conf *conf = mddev->private;
struct raid10_info *tmp;
int count = 0;
unsigned long flags;
/*
* Find all non-in_sync disks within the RAID10 configuration
* and mark them in_sync
*/
for (i = 0; i < conf->geo.raid_disks; i++) {
tmp = conf->mirrors + i;
if (tmp->replacement
&& tmp->replacement->recovery_offset == MaxSector
&& !test_bit(Faulty, &tmp->replacement->flags)
&& !test_and_set_bit(In_sync, &tmp->replacement->flags)) {
/* Replacement has just become active */
if (!tmp->rdev
|| !test_and_clear_bit(In_sync, &tmp->rdev->flags))
count++;
if (tmp->rdev) {
/* Replaced device not technically faulty,
* but we need to be sure it gets removed
* and never re-added.
*/
set_bit(Faulty, &tmp->rdev->flags);
sysfs_notify_dirent_safe(
tmp->rdev->sysfs_state);
}
sysfs_notify_dirent_safe(tmp->replacement->sysfs_state);
} else if (tmp->rdev
&& tmp->rdev->recovery_offset == MaxSector
&& !test_bit(Faulty, &tmp->rdev->flags)
&& !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
count++;
sysfs_notify_dirent_safe(tmp->rdev->sysfs_state);
}
}
spin_lock_irqsave(&conf->device_lock, flags);
mddev->degraded -= count;
spin_unlock_irqrestore(&conf->device_lock, flags);
print_conf(conf);
return count;
}
static int raid10_add_disk(struct mddev *mddev, struct md_rdev *rdev)
{
struct r10conf *conf = mddev->private;
int err = -EEXIST;
int mirror, repl_slot = -1;
int first = 0;
int last = conf->geo.raid_disks - 1;
struct raid10_info *p;
if (mddev->recovery_cp < MaxSector)
/* only hot-add to in-sync arrays, as recovery is
* very different from resync
*/
return -EBUSY;
if (rdev->saved_raid_disk < 0 && !_enough(conf, 1, -1))
return -EINVAL;
if (md_integrity_add_rdev(rdev, mddev))
return -ENXIO;
if (rdev->raid_disk >= 0)
first = last = rdev->raid_disk;
if (rdev->saved_raid_disk >= first &&
rdev->saved_raid_disk < conf->geo.raid_disks &&
conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
mirror = rdev->saved_raid_disk;
else
mirror = first;
for ( ; mirror <= last ; mirror++) {
p = &conf->mirrors[mirror];
if (p->recovery_disabled == mddev->recovery_disabled)
continue;
if (p->rdev) {
if (test_bit(WantReplacement, &p->rdev->flags) &&
p->replacement == NULL && repl_slot < 0)
repl_slot = mirror;
continue;
}
if (mddev->gendisk)
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
p->head_position = 0;
p->recovery_disabled = mddev->recovery_disabled - 1;
rdev->raid_disk = mirror;
err = 0;
if (rdev->saved_raid_disk != mirror)
conf->fullsync = 1;
rcu_assign_pointer(p->rdev, rdev);
break;
}
if (err && repl_slot >= 0) {
p = &conf->mirrors[repl_slot];
clear_bit(In_sync, &rdev->flags);
set_bit(Replacement, &rdev->flags);
rdev->raid_disk = repl_slot;
err = 0;
if (mddev->gendisk)
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
conf->fullsync = 1;
rcu_assign_pointer(p->replacement, rdev);
}
print_conf(conf);
return err;
}
static int raid10_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
{
struct r10conf *conf = mddev->private;
int err = 0;
int number = rdev->raid_disk;
struct md_rdev **rdevp;
struct raid10_info *p;
print_conf(conf);
if (unlikely(number >= mddev->raid_disks))
return 0;
p = conf->mirrors + number;
if (rdev == p->rdev)
rdevp = &p->rdev;
else if (rdev == p->replacement)
rdevp = &p->replacement;
else
return 0;
if (test_bit(In_sync, &rdev->flags) ||
atomic_read(&rdev->nr_pending)) {
err = -EBUSY;
goto abort;
}
/* Only remove non-faulty devices if recovery
* is not possible.
*/
if (!test_bit(Faulty, &rdev->flags) &&
mddev->recovery_disabled != p->recovery_disabled &&
(!p->replacement || p->replacement == rdev) &&
number < conf->geo.raid_disks &&
enough(conf, -1)) {
err = -EBUSY;
goto abort;
}
*rdevp = NULL;
if (!test_bit(RemoveSynchronized, &rdev->flags)) {
synchronize_rcu();
if (atomic_read(&rdev->nr_pending)) {
/* lost the race, try later */
err = -EBUSY;
*rdevp = rdev;
goto abort;
}
}
if (p->replacement) {
/* We must have just cleared 'rdev' */
p->rdev = p->replacement;
clear_bit(Replacement, &p->replacement->flags);
smp_mb(); /* Make sure other CPUs may see both as identical
* but will never see neither -- if they are careful.
*/
p->replacement = NULL;
}
clear_bit(WantReplacement, &rdev->flags);
err = md_integrity_register(mddev);
abort:
print_conf(conf);
return err;
}
static void __end_sync_read(struct r10bio *r10_bio, struct bio *bio, int d)
{
struct r10conf *conf = r10_bio->mddev->private;
if (!bio->bi_status)
set_bit(R10BIO_Uptodate, &r10_bio->state);
else
/* The write handler will notice the lack of
* R10BIO_Uptodate and record any errors etc
*/
atomic_add(r10_bio->sectors,
&conf->mirrors[d].rdev->corrected_errors);
/* for reconstruct, we always reschedule after a read.
* for resync, only after all reads
*/
rdev_dec_pending(conf->mirrors[d].rdev, conf->mddev);
if (test_bit(R10BIO_IsRecover, &r10_bio->state) ||
atomic_dec_and_test(&r10_bio->remaining)) {
/* we have read all the blocks,
* do the comparison in process context in raid10d
*/
reschedule_retry(r10_bio);
}
}
static void end_sync_read(struct bio *bio)
{
struct r10bio *r10_bio = get_resync_r10bio(bio);
struct r10conf *conf = r10_bio->mddev->private;
int d = find_bio_disk(conf, r10_bio, bio, NULL, NULL);
__end_sync_read(r10_bio, bio, d);
}
static void end_reshape_read(struct bio *bio)
{
/* reshape read bio isn't allocated from r10buf_pool */
struct r10bio *r10_bio = bio->bi_private;
__end_sync_read(r10_bio, bio, r10_bio->read_slot);
}
static void end_sync_request(struct r10bio *r10_bio)
{
struct mddev *mddev = r10_bio->mddev;
while (atomic_dec_and_test(&r10_bio->remaining)) {
if (r10_bio->master_bio == NULL) {
/* the primary of several recovery bios */
sector_t s = r10_bio->sectors;
if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
test_bit(R10BIO_WriteError, &r10_bio->state))
reschedule_retry(r10_bio);
else
put_buf(r10_bio);
md_done_sync(mddev, s, 1);
break;
} else {
struct r10bio *r10_bio2 = (struct r10bio *)r10_bio->master_bio;
if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
test_bit(R10BIO_WriteError, &r10_bio->state))
reschedule_retry(r10_bio);
else
put_buf(r10_bio);
r10_bio = r10_bio2;
}
}
}
static void end_sync_write(struct bio *bio)
{
struct r10bio *r10_bio = get_resync_r10bio(bio);
struct mddev *mddev = r10_bio->mddev;
struct r10conf *conf = mddev->private;
int d;
sector_t first_bad;
int bad_sectors;
int slot;
int repl;
struct md_rdev *rdev = NULL;
d = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
if (repl)
rdev = conf->mirrors[d].replacement;
else
rdev = conf->mirrors[d].rdev;
if (bio->bi_status) {
if (repl)
md_error(mddev, rdev);
else {
set_bit(WriteErrorSeen, &rdev->flags);
if (!test_and_set_bit(WantReplacement, &rdev->flags))
set_bit(MD_RECOVERY_NEEDED,
&rdev->mddev->recovery);
set_bit(R10BIO_WriteError, &r10_bio->state);
}
} else if (is_badblock(rdev,
r10_bio->devs[slot].addr,
r10_bio->sectors,
&first_bad, &bad_sectors))
set_bit(R10BIO_MadeGood, &r10_bio->state);
rdev_dec_pending(rdev, mddev);
end_sync_request(r10_bio);
}
/*
* Note: sync and recover and handled very differently for raid10
* This code is for resync.
* For resync, we read through virtual addresses and read all blocks.
* If there is any error, we schedule a write. The lowest numbered
* drive is authoritative.
* However requests come for physical address, so we need to map.
* For every physical address there are raid_disks/copies virtual addresses,
* which is always are least one, but is not necessarly an integer.
* This means that a physical address can span multiple chunks, so we may
* have to submit multiple io requests for a single sync request.
*/
/*
* We check if all blocks are in-sync and only write to blocks that
* aren't in sync
*/
static void sync_request_write(struct mddev *mddev, struct r10bio *r10_bio)
{
struct r10conf *conf = mddev->private;
int i, first;
struct bio *tbio, *fbio;
int vcnt;
struct page **tpages, **fpages;
atomic_set(&r10_bio->remaining, 1);
/* find the first device with a block */
for (i=0; i<conf->copies; i++)
if (!r10_bio->devs[i].bio->bi_status)
break;
if (i == conf->copies)
goto done;
first = i;
fbio = r10_bio->devs[i].bio;
fbio->bi_iter.bi_size = r10_bio->sectors << 9;
fbio->bi_iter.bi_idx = 0;
fpages = get_resync_pages(fbio)->pages;
vcnt = (r10_bio->sectors + (PAGE_SIZE >> 9) - 1) >> (PAGE_SHIFT - 9);
/* now find blocks with errors */
for (i=0 ; i < conf->copies ; i++) {
int j, d;
struct md_rdev *rdev;
struct resync_pages *rp;
tbio = r10_bio->devs[i].bio;
if (tbio->bi_end_io != end_sync_read)
continue;
if (i == first)
continue;
tpages = get_resync_pages(tbio)->pages;
d = r10_bio->devs[i].devnum;
rdev = conf->mirrors[d].rdev;
if (!r10_bio->devs[i].bio->bi_status) {
/* We know that the bi_io_vec layout is the same for
* both 'first' and 'i', so we just compare them.
* All vec entries are PAGE_SIZE;
*/
int sectors = r10_bio->sectors;
for (j = 0; j < vcnt; j++) {
int len = PAGE_SIZE;
if (sectors < (len / 512))
len = sectors * 512;
if (memcmp(page_address(fpages[j]),
page_address(tpages[j]),
len))
break;
sectors -= len/512;
}
if (j == vcnt)
continue;
atomic64_add(r10_bio->sectors, &mddev->resync_mismatches);
if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
/* Don't fix anything. */
continue;
} else if (test_bit(FailFast, &rdev->flags)) {
/* Just give up on this device */
md_error(rdev->mddev, rdev);
continue;
}
/* Ok, we need to write this bio, either to correct an
* inconsistency or to correct an unreadable block.
* First we need to fixup bv_offset, bv_len and
* bi_vecs, as the read request might have corrupted these
*/
rp = get_resync_pages(tbio);
bio_reset(tbio, conf->mirrors[d].rdev->bdev, REQ_OP_WRITE);
md_bio_reset_resync_pages(tbio, rp, fbio->bi_iter.bi_size);
rp->raid_bio = r10_bio;
tbio->bi_private = rp;
tbio->bi_iter.bi_sector = r10_bio->devs[i].addr;
tbio->bi_end_io = end_sync_write;
bio_copy_data(tbio, fbio);
atomic_inc(&conf->mirrors[d].rdev->nr_pending);
atomic_inc(&r10_bio->remaining);
md_sync_acct(conf->mirrors[d].rdev->bdev, bio_sectors(tbio));
if (test_bit(FailFast, &conf->mirrors[d].rdev->flags))
tbio->bi_opf |= MD_FAILFAST;
tbio->bi_iter.bi_sector += conf->mirrors[d].rdev->data_offset;
submit_bio_noacct(tbio);
}
/* Now write out to any replacement devices
* that are active
*/
for (i = 0; i < conf->copies; i++) {
int d;
tbio = r10_bio->devs[i].repl_bio;
if (!tbio || !tbio->bi_end_io)
continue;
if (r10_bio->devs[i].bio->bi_end_io != end_sync_write
&& r10_bio->devs[i].bio != fbio)
bio_copy_data(tbio, fbio);
d = r10_bio->devs[i].devnum;
atomic_inc(&r10_bio->remaining);
md_sync_acct(conf->mirrors[d].replacement->bdev,
bio_sectors(tbio));
submit_bio_noacct(tbio);
}
done:
if (atomic_dec_and_test(&r10_bio->remaining)) {
md_done_sync(mddev, r10_bio->sectors, 1);
put_buf(r10_bio);
}
}
/*
* Now for the recovery code.
* Recovery happens across physical sectors.
* We recover all non-is_sync drives by finding the virtual address of
* each, and then choose a working drive that also has that virt address.
* There is a separate r10_bio for each non-in_sync drive.
* Only the first two slots are in use. The first for reading,
* The second for writing.
*
*/
static void fix_recovery_read_error(struct r10bio *r10_bio)
{
/* We got a read error during recovery.
* We repeat the read in smaller page-sized sections.
* If a read succeeds, write it to the new device or record
* a bad block if we cannot.
* If a read fails, record a bad block on both old and
* new devices.
*/
struct mddev *mddev = r10_bio->mddev;
struct r10conf *conf = mddev->private;
struct bio *bio = r10_bio->devs[0].bio;
sector_t sect = 0;
int sectors = r10_bio->sectors;
int idx = 0;
int dr = r10_bio->devs[0].devnum;
int dw = r10_bio->devs[1].devnum;
struct page **pages = get_resync_pages(bio)->pages;
while (sectors) {
int s = sectors;
struct md_rdev *rdev;
sector_t addr;
int ok;
if (s > (PAGE_SIZE>>9))
s = PAGE_SIZE >> 9;
rdev = conf->mirrors[dr].rdev;
addr = r10_bio->devs[0].addr + sect,
ok = sync_page_io(rdev,
addr,
s << 9,
pages[idx],
REQ_OP_READ, false);
if (ok) {
rdev = conf->mirrors[dw].rdev;
addr = r10_bio->devs[1].addr + sect;
ok = sync_page_io(rdev,
addr,
s << 9,
pages[idx],
REQ_OP_WRITE, false);
if (!ok) {
set_bit(WriteErrorSeen, &rdev->flags);
if (!test_and_set_bit(WantReplacement,
&rdev->flags))
set_bit(MD_RECOVERY_NEEDED,
&rdev->mddev->recovery);
}
}
if (!ok) {
/* We don't worry if we cannot set a bad block -
* it really is bad so there is no loss in not
* recording it yet
*/
rdev_set_badblocks(rdev, addr, s, 0);
if (rdev != conf->mirrors[dw].rdev) {
/* need bad block on destination too */
struct md_rdev *rdev2 = conf->mirrors[dw].rdev;
addr = r10_bio->devs[1].addr + sect;
ok = rdev_set_badblocks(rdev2, addr, s, 0);
if (!ok) {
/* just abort the recovery */
pr_notice("md/raid10:%s: recovery aborted due to read error\n",
mdname(mddev));
conf->mirrors[dw].recovery_disabled
= mddev->recovery_disabled;
set_bit(MD_RECOVERY_INTR,
&mddev->recovery);
break;
}
}
}
sectors -= s;
sect += s;
idx++;
}
}
static void recovery_request_write(struct mddev *mddev, struct r10bio *r10_bio)
{
struct r10conf *conf = mddev->private;
int d;
struct bio *wbio = r10_bio->devs[1].bio;
struct bio *wbio2 = r10_bio->devs[1].repl_bio;
/* Need to test wbio2->bi_end_io before we call
* submit_bio_noacct as if the former is NULL,
* the latter is free to free wbio2.
*/
if (wbio2 && !wbio2->bi_end_io)
wbio2 = NULL;
if (!test_bit(R10BIO_Uptodate, &r10_bio->state)) {
fix_recovery_read_error(r10_bio);
if (wbio->bi_end_io)
end_sync_request(r10_bio);
if (wbio2)
end_sync_request(r10_bio);
return;
}
/*
* share the pages with the first bio
* and submit the write request
*/
d = r10_bio->devs[1].devnum;
if (wbio->bi_end_io) {
atomic_inc(&conf->mirrors[d].rdev->nr_pending);
md_sync_acct(conf->mirrors[d].rdev->bdev, bio_sectors(wbio));
submit_bio_noacct(wbio);
}
if (wbio2) {
atomic_inc(&conf->mirrors[d].replacement->nr_pending);
md_sync_acct(conf->mirrors[d].replacement->bdev,
bio_sectors(wbio2));
submit_bio_noacct(wbio2);
}
}
/*
* Used by fix_read_error() to decay the per rdev read_errors.
* We halve the read error count for every hour that has elapsed
* since the last recorded read error.
*
*/
static void check_decay_read_errors(struct mddev *mddev, struct md_rdev *rdev)
{
long cur_time_mon;
unsigned long hours_since_last;
unsigned int read_errors = atomic_read(&rdev->read_errors);
cur_time_mon = ktime_get_seconds();
if (rdev->last_read_error == 0) {
/* first time we've seen a read error */
rdev->last_read_error = cur_time_mon;
return;
}
hours_since_last = (long)(cur_time_mon -
rdev->last_read_error) / 3600;
rdev->last_read_error = cur_time_mon;
/*
* if hours_since_last is > the number of bits in read_errors
* just set read errors to 0. We do this to avoid
* overflowing the shift of read_errors by hours_since_last.
*/
if (hours_since_last >= 8 * sizeof(read_errors))
atomic_set(&rdev->read_errors, 0);
else
atomic_set(&rdev->read_errors, read_errors >> hours_since_last);
}
static int r10_sync_page_io(struct md_rdev *rdev, sector_t sector,
int sectors, struct page *page, enum req_op op)
{
sector_t first_bad;
int bad_sectors;
if (is_badblock(rdev, sector, sectors, &first_bad, &bad_sectors)
&& (op == REQ_OP_READ || test_bit(WriteErrorSeen, &rdev->flags)))
return -1;
if (sync_page_io(rdev, sector, sectors << 9, page, op, false))
/* success */
return 1;
if (op == REQ_OP_WRITE) {
set_bit(WriteErrorSeen, &rdev->flags);
if (!test_and_set_bit(WantReplacement, &rdev->flags))
set_bit(MD_RECOVERY_NEEDED,
&rdev->mddev->recovery);
}
/* need to record an error - either for the block or the device */
if (!rdev_set_badblocks(rdev, sector, sectors, 0))
md_error(rdev->mddev, rdev);
return 0;
}
/*
* This is a kernel thread which:
*
* 1. Retries failed read operations on working mirrors.
* 2. Updates the raid superblock when problems encounter.
* 3. Performs writes following reads for array synchronising.
*/
static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10bio *r10_bio)
{
int sect = 0; /* Offset from r10_bio->sector */
int sectors = r10_bio->sectors, slot = r10_bio->read_slot;
struct md_rdev *rdev;
int max_read_errors = atomic_read(&mddev->max_corr_read_errors);
int d = r10_bio->devs[slot].devnum;
/* still own a reference to this rdev, so it cannot
* have been cleared recently.
*/
rdev = conf->mirrors[d].rdev;
if (test_bit(Faulty, &rdev->flags))
/* drive has already been failed, just ignore any
more fix_read_error() attempts */
return;
check_decay_read_errors(mddev, rdev);
atomic_inc(&rdev->read_errors);
if (atomic_read(&rdev->read_errors) > max_read_errors) {
pr_notice("md/raid10:%s: %pg: Raid device exceeded read_error threshold [cur %d:max %d]\n",
mdname(mddev), rdev->bdev,
atomic_read(&rdev->read_errors), max_read_errors);
pr_notice("md/raid10:%s: %pg: Failing raid device\n",
mdname(mddev), rdev->bdev);
md_error(mddev, rdev);
r10_bio->devs[slot].bio = IO_BLOCKED;
return;
}
while(sectors) {
int s = sectors;
int sl = slot;
int success = 0;
int start;
if (s > (PAGE_SIZE>>9))
s = PAGE_SIZE >> 9;
rcu_read_lock();
do {
sector_t first_bad;
int bad_sectors;
d = r10_bio->devs[sl].devnum;
rdev = rcu_dereference(conf->mirrors[d].rdev);
if (rdev &&
test_bit(In_sync, &rdev->flags) &&
!test_bit(Faulty, &rdev->flags) &&
is_badblock(rdev, r10_bio->devs[sl].addr + sect, s,
&first_bad, &bad_sectors) == 0) {
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
success = sync_page_io(rdev,
r10_bio->devs[sl].addr +
sect,
s<<9,
conf->tmppage,
REQ_OP_READ, false);
rdev_dec_pending(rdev, mddev);
rcu_read_lock();
if (success)
break;
}
sl++;
if (sl == conf->copies)
sl = 0;
} while (sl != slot);
rcu_read_unlock();
if (!success) {
/* Cannot read from anywhere, just mark the block
* as bad on the first device to discourage future
* reads.
*/
int dn = r10_bio->devs[slot].devnum;
rdev = conf->mirrors[dn].rdev;
if (!rdev_set_badblocks(
rdev,
r10_bio->devs[slot].addr
+ sect,
s, 0)) {
md_error(mddev, rdev);
r10_bio->devs[slot].bio
= IO_BLOCKED;
}
break;
}
start = sl;
/* write it back and re-read */
rcu_read_lock();
while (sl != slot) {
if (sl==0)
sl = conf->copies;
sl--;
d = r10_bio->devs[sl].devnum;
rdev = rcu_dereference(conf->mirrors[d].rdev);
if (!rdev ||
test_bit(Faulty, &rdev->flags) ||
!test_bit(In_sync, &rdev->flags))
continue;
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
if (r10_sync_page_io(rdev,
r10_bio->devs[sl].addr +
sect,
s, conf->tmppage, REQ_OP_WRITE)
== 0) {
/* Well, this device is dead */
pr_notice("md/raid10:%s: read correction write failed (%d sectors at %llu on %pg)\n",
mdname(mddev), s,
(unsigned long long)(
sect +
choose_data_offset(r10_bio,
rdev)),
rdev->bdev);
pr_notice("md/raid10:%s: %pg: failing drive\n",
mdname(mddev),
rdev->bdev);
}
rdev_dec_pending(rdev, mddev);
rcu_read_lock();
}
sl = start;
while (sl != slot) {
if (sl==0)
sl = conf->copies;
sl--;
d = r10_bio->devs[sl].devnum;
rdev = rcu_dereference(conf->mirrors[d].rdev);
if (!rdev ||
test_bit(Faulty, &rdev->flags) ||
!test_bit(In_sync, &rdev->flags))
continue;
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
switch (r10_sync_page_io(rdev,
r10_bio->devs[sl].addr +
sect,
s, conf->tmppage, REQ_OP_READ)) {
case 0:
/* Well, this device is dead */
pr_notice("md/raid10:%s: unable to read back corrected sectors (%d sectors at %llu on %pg)\n",
mdname(mddev), s,
(unsigned long long)(
sect +
choose_data_offset(r10_bio, rdev)),
rdev->bdev);
pr_notice("md/raid10:%s: %pg: failing drive\n",
mdname(mddev),
rdev->bdev);
break;
case 1:
pr_info("md/raid10:%s: read error corrected (%d sectors at %llu on %pg)\n",
mdname(mddev), s,
(unsigned long long)(
sect +
choose_data_offset(r10_bio, rdev)),
rdev->bdev);
atomic_add(s, &rdev->corrected_errors);
}
rdev_dec_pending(rdev, mddev);
rcu_read_lock();
}
rcu_read_unlock();
sectors -= s;
sect += s;
}
}
static int narrow_write_error(struct r10bio *r10_bio, int i)
{
struct bio *bio = r10_bio->master_bio;
struct mddev *mddev = r10_bio->mddev;
struct r10conf *conf = mddev->private;
struct md_rdev *rdev = conf->mirrors[r10_bio->devs[i].devnum].rdev;
/* bio has the data to be written to slot 'i' where
* we just recently had a write error.
* We repeatedly clone the bio and trim down to one block,
* then try the write. Where the write fails we record
* a bad block.
* It is conceivable that the bio doesn't exactly align with
* blocks. We must handle this.
*
* We currently own a reference to the rdev.
*/
int block_sectors;
sector_t sector;
int sectors;
int sect_to_write = r10_bio->sectors;
int ok = 1;
if (rdev->badblocks.shift < 0)
return 0;
block_sectors = roundup(1 << rdev->badblocks.shift,
bdev_logical_block_size(rdev->bdev) >> 9);
sector = r10_bio->sector;
sectors = ((r10_bio->sector + block_sectors)
& ~(sector_t)(block_sectors - 1))
- sector;
while (sect_to_write) {
struct bio *wbio;
sector_t wsector;
if (sectors > sect_to_write)
sectors = sect_to_write;
/* Write at 'sector' for 'sectors' */
wbio = bio_alloc_clone(rdev->bdev, bio, GFP_NOIO,
&mddev->bio_set);
bio_trim(wbio, sector - bio->bi_iter.bi_sector, sectors);
wsector = r10_bio->devs[i].addr + (sector - r10_bio->sector);
wbio->bi_iter.bi_sector = wsector +
choose_data_offset(r10_bio, rdev);
wbio->bi_opf = REQ_OP_WRITE;
if (submit_bio_wait(wbio) < 0)
/* Failure! */
ok = rdev_set_badblocks(rdev, wsector,
sectors, 0)
&& ok;
bio_put(wbio);
sect_to_write -= sectors;
sector += sectors;
sectors = block_sectors;
}
return ok;
}
static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio)
{
int slot = r10_bio->read_slot;
struct bio *bio;
struct r10conf *conf = mddev->private;
struct md_rdev *rdev = r10_bio->devs[slot].rdev;
/* we got a read error. Maybe the drive is bad. Maybe just
* the block and we can fix it.
* We freeze all other IO, and try reading the block from
* other devices. When we find one, we re-write
* and check it that fixes the read error.
* This is all done synchronously while the array is
* frozen.
*/
bio = r10_bio->devs[slot].bio;
bio_put(bio);
r10_bio->devs[slot].bio = NULL;
if (mddev->ro)
r10_bio->devs[slot].bio = IO_BLOCKED;
else if (!test_bit(FailFast, &rdev->flags)) {
freeze_array(conf, 1);
fix_read_error(conf, mddev, r10_bio);
unfreeze_array(conf);
} else
md_error(mddev, rdev);
rdev_dec_pending(rdev, mddev);
r10_bio->state = 0;
raid10_read_request(mddev, r10_bio->master_bio, r10_bio, false);
/*
* allow_barrier after re-submit to ensure no sync io
* can be issued while regular io pending.
*/
allow_barrier(conf);
}
static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio)
{
/* Some sort of write request has finished and it
* succeeded in writing where we thought there was a
* bad block. So forget the bad block.
* Or possibly if failed and we need to record
* a bad block.
*/
int m;
struct md_rdev *rdev;
if (test_bit(R10BIO_IsSync, &r10_bio->state) ||
test_bit(R10BIO_IsRecover, &r10_bio->state)) {
for (m = 0; m < conf->copies; m++) {
int dev = r10_bio->devs[m].devnum;
rdev = conf->mirrors[dev].rdev;
if (r10_bio->devs[m].bio == NULL ||
r10_bio->devs[m].bio->bi_end_io == NULL)
continue;
if (!r10_bio->devs[m].bio->bi_status) {
rdev_clear_badblocks(
rdev,
r10_bio->devs[m].addr,
r10_bio->sectors, 0);
} else {
if (!rdev_set_badblocks(
rdev,
r10_bio->devs[m].addr,
r10_bio->sectors, 0))
md_error(conf->mddev, rdev);
}
rdev = conf->mirrors[dev].replacement;
if (r10_bio->devs[m].repl_bio == NULL ||
r10_bio->devs[m].repl_bio->bi_end_io == NULL)
continue;
if (!r10_bio->devs[m].repl_bio->bi_status) {
rdev_clear_badblocks(
rdev,
r10_bio->devs[m].addr,
r10_bio->sectors, 0);
} else {
if (!rdev_set_badblocks(
rdev,
r10_bio->devs[m].addr,
r10_bio->sectors, 0))
md_error(conf->mddev, rdev);
}
}
put_buf(r10_bio);
} else {
bool fail = false;
for (m = 0; m < conf->copies; m++) {
int dev = r10_bio->devs[m].devnum;
struct bio *bio = r10_bio->devs[m].bio;
rdev = conf->mirrors[dev].rdev;
if (bio == IO_MADE_GOOD) {
rdev_clear_badblocks(
rdev,
r10_bio->devs[m].addr,
r10_bio->sectors, 0);
rdev_dec_pending(rdev, conf->mddev);
} else if (bio != NULL && bio->bi_status) {
fail = true;
if (!narrow_write_error(r10_bio, m)) {
md_error(conf->mddev, rdev);
set_bit(R10BIO_Degraded,
&r10_bio->state);
}
rdev_dec_pending(rdev, conf->mddev);
}
bio = r10_bio->devs[m].repl_bio;
rdev = conf->mirrors[dev].replacement;
if (rdev && bio == IO_MADE_GOOD) {
rdev_clear_badblocks(
rdev,
r10_bio->devs[m].addr,
r10_bio->sectors, 0);
rdev_dec_pending(rdev, conf->mddev);
}
}
if (fail) {
spin_lock_irq(&conf->device_lock);
list_add(&r10_bio->retry_list, &conf->bio_end_io_list);
conf->nr_queued++;
spin_unlock_irq(&conf->device_lock);
/*
* In case freeze_array() is waiting for condition
* nr_pending == nr_queued + extra to be true.
*/
wake_up(&conf->wait_barrier);
md_wakeup_thread(conf->mddev->thread);
} else {
if (test_bit(R10BIO_WriteError,
&r10_bio->state))
close_write(r10_bio);
raid_end_bio_io(r10_bio);
}
}
}
static void raid10d(struct md_thread *thread)
{
struct mddev *mddev = thread->mddev;
struct r10bio *r10_bio;
unsigned long flags;
struct r10conf *conf = mddev->private;
struct list_head *head = &conf->retry_list;
struct blk_plug plug;
md_check_recovery(mddev);
if (!list_empty_careful(&conf->bio_end_io_list) &&
!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
LIST_HEAD(tmp);
spin_lock_irqsave(&conf->device_lock, flags);
if (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
while (!list_empty(&conf->bio_end_io_list)) {
list_move(conf->bio_end_io_list.prev, &tmp);
conf->nr_queued--;
}
}
spin_unlock_irqrestore(&conf->device_lock, flags);
while (!list_empty(&tmp)) {
r10_bio = list_first_entry(&tmp, struct r10bio,
retry_list);
list_del(&r10_bio->retry_list);
if (mddev->degraded)
set_bit(R10BIO_Degraded, &r10_bio->state);
if (test_bit(R10BIO_WriteError,
&r10_bio->state))
close_write(r10_bio);
raid_end_bio_io(r10_bio);
}
}
blk_start_plug(&plug);
for (;;) {
flush_pending_writes(conf);
spin_lock_irqsave(&conf->device_lock, flags);
if (list_empty(head)) {
spin_unlock_irqrestore(&conf->device_lock, flags);
break;
}
r10_bio = list_entry(head->prev, struct r10bio, retry_list);
list_del(head->prev);
conf->nr_queued--;
spin_unlock_irqrestore(&conf->device_lock, flags);
mddev = r10_bio->mddev;
conf = mddev->private;
if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
test_bit(R10BIO_WriteError, &r10_bio->state))
handle_write_completed(conf, r10_bio);
else if (test_bit(R10BIO_IsReshape, &r10_bio->state))
reshape_request_write(mddev, r10_bio);
else if (test_bit(R10BIO_IsSync, &r10_bio->state))
sync_request_write(mddev, r10_bio);
else if (test_bit(R10BIO_IsRecover, &r10_bio->state))
recovery_request_write(mddev, r10_bio);
else if (test_bit(R10BIO_ReadError, &r10_bio->state))
handle_read_error(mddev, r10_bio);
else
WARN_ON_ONCE(1);
cond_resched();
if (mddev->sb_flags & ~(1<<MD_SB_CHANGE_PENDING))
md_check_recovery(mddev);
}
blk_finish_plug(&plug);
}
static int init_resync(struct r10conf *conf)
{
int ret, buffs, i;
buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
BUG_ON(mempool_initialized(&conf->r10buf_pool));
conf->have_replacement = 0;
for (i = 0; i < conf->geo.raid_disks; i++)
if (conf->mirrors[i].replacement)
conf->have_replacement = 1;
ret = mempool_init(&conf->r10buf_pool, buffs,
r10buf_pool_alloc, r10buf_pool_free, conf);
if (ret)
return ret;
conf->next_resync = 0;
return 0;
}
static struct r10bio *raid10_alloc_init_r10buf(struct r10conf *conf)
{
struct r10bio *r10bio = mempool_alloc(&conf->r10buf_pool, GFP_NOIO);
struct rsync_pages *rp;
struct bio *bio;
int nalloc;
int i;
if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery) ||
test_bit(MD_RECOVERY_RESHAPE, &conf->mddev->recovery))
nalloc = conf->copies; /* resync */
else
nalloc = 2; /* recovery */
for (i = 0; i < nalloc; i++) {
bio = r10bio->devs[i].bio;
rp = bio->bi_private;
bio_reset(bio, NULL, 0);
bio->bi_private = rp;
bio = r10bio->devs[i].repl_bio;
if (bio) {
rp = bio->bi_private;
bio_reset(bio, NULL, 0);
bio->bi_private = rp;
}
}
return r10bio;
}
/*
* Set cluster_sync_high since we need other nodes to add the
* range [cluster_sync_low, cluster_sync_high] to suspend list.
*/
static void raid10_set_cluster_sync_high(struct r10conf *conf)
{
sector_t window_size;
int extra_chunk, chunks;
/*
* First, here we define "stripe" as a unit which across
* all member devices one time, so we get chunks by use
* raid_disks / near_copies. Otherwise, if near_copies is
* close to raid_disks, then resync window could increases
* linearly with the increase of raid_disks, which means
* we will suspend a really large IO window while it is not
* necessary. If raid_disks is not divisible by near_copies,
* an extra chunk is needed to ensure the whole "stripe" is
* covered.
*/
chunks = conf->geo.raid_disks / conf->geo.near_copies;
if (conf->geo.raid_disks % conf->geo.near_copies == 0)
extra_chunk = 0;
else
extra_chunk = 1;
window_size = (chunks + extra_chunk) * conf->mddev->chunk_sectors;
/*
* At least use a 32M window to align with raid1's resync window
*/
window_size = (CLUSTER_RESYNC_WINDOW_SECTORS > window_size) ?
CLUSTER_RESYNC_WINDOW_SECTORS : window_size;
conf->cluster_sync_high = conf->cluster_sync_low + window_size;
}
/*
* perform a "sync" on one "block"
*
* We need to make sure that no normal I/O request - particularly write
* requests - conflict with active sync requests.
*
* This is achieved by tracking pending requests and a 'barrier' concept
* that can be installed to exclude normal IO requests.
*
* Resync and recovery are handled very differently.
* We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery.
*
* For resync, we iterate over virtual addresses, read all copies,
* and update if there are differences. If only one copy is live,
* skip it.
* For recovery, we iterate over physical addresses, read a good
* value for each non-in_sync drive, and over-write.
*
* So, for recovery we may have several outstanding complex requests for a
* given address, one for each out-of-sync device. We model this by allocating
* a number of r10_bio structures, one for each out-of-sync device.
* As we setup these structures, we collect all bio's together into a list
* which we then process collectively to add pages, and then process again
* to pass to submit_bio_noacct.
*
* The r10_bio structures are linked using a borrowed master_bio pointer.
* This link is counted in ->remaining. When the r10_bio that points to NULL
* has its remaining count decremented to 0, the whole complex operation
* is complete.
*
*/
static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
int *skipped)
{
struct r10conf *conf = mddev->private;
struct r10bio *r10_bio;
struct bio *biolist = NULL, *bio;
sector_t max_sector, nr_sectors;
int i;
int max_sync;
sector_t sync_blocks;
sector_t sectors_skipped = 0;
int chunks_skipped = 0;
sector_t chunk_mask = conf->geo.chunk_mask;
int page_idx = 0;
int error_disk = -1;
/*
* Allow skipping a full rebuild for incremental assembly
* of a clean array, like RAID1 does.
*/
if (mddev->bitmap == NULL &&
mddev->recovery_cp == MaxSector &&
mddev->reshape_position == MaxSector &&
!test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
conf->fullsync == 0) {
*skipped = 1;
return mddev->dev_sectors - sector_nr;
}
if (!mempool_initialized(&conf->r10buf_pool))
if (init_resync(conf))
return 0;
skipped:
max_sector = mddev->dev_sectors;
if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
max_sector = mddev->resync_max_sectors;
if (sector_nr >= max_sector) {
conf->cluster_sync_low = 0;
conf->cluster_sync_high = 0;
/* If we aborted, we need to abort the
* sync on the 'current' bitmap chucks (there can
* be several when recovering multiple devices).
* as we may have started syncing it but not finished.
* We can find the current address in
* mddev->curr_resync, but for recovery,
* we need to convert that to several
* virtual addresses.
*/
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
end_reshape(conf);
close_sync(conf);
return 0;
}
if (mddev->curr_resync < max_sector) { /* aborted */
if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
md_bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
&sync_blocks, 1);
else for (i = 0; i < conf->geo.raid_disks; i++) {
sector_t sect =
raid10_find_virt(conf, mddev->curr_resync, i);
md_bitmap_end_sync(mddev->bitmap, sect,
&sync_blocks, 1);
}
} else {
/* completed sync */
if ((!mddev->bitmap || conf->fullsync)
&& conf->have_replacement
&& test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
/* Completed a full sync so the replacements
* are now fully recovered.
*/
rcu_read_lock();
for (i = 0; i < conf->geo.raid_disks; i++) {
struct md_rdev *rdev =
rcu_dereference(conf->mirrors[i].replacement);
if (rdev)
rdev->recovery_offset = MaxSector;
}
rcu_read_unlock();
}
conf->fullsync = 0;
}
md_bitmap_close_sync(mddev->bitmap);
close_sync(conf);
*skipped = 1;
return sectors_skipped;
}
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
return reshape_request(mddev, sector_nr, skipped);
if (chunks_skipped >= conf->geo.raid_disks) {
pr_err("md/raid10:%s: %s fails\n", mdname(mddev),
test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ? "resync" : "recovery");
if (error_disk >= 0 &&
!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
/*
* recovery fails, set mirrors.recovery_disabled,
* device shouldn't be added to there.
*/
conf->mirrors[error_disk].recovery_disabled =
mddev->recovery_disabled;
return 0;
}
/*
* if there has been nothing to do on any drive,
* then there is nothing to do at all.
*/
*skipped = 1;
return (max_sector - sector_nr) + sectors_skipped;
}
if (max_sector > mddev->resync_max)
max_sector = mddev->resync_max; /* Don't do IO beyond here */
/* make sure whole request will fit in a chunk - if chunks
* are meaningful
*/
if (conf->geo.near_copies < conf->geo.raid_disks &&
max_sector > (sector_nr | chunk_mask))
max_sector = (sector_nr | chunk_mask) + 1;
/*
* If there is non-resync activity waiting for a turn, then let it
* though before starting on this new sync request.
*/
if (conf->nr_waiting)
schedule_timeout_uninterruptible(1);
/* Again, very different code for resync and recovery.
* Both must result in an r10bio with a list of bios that
* have bi_end_io, bi_sector, bi_bdev set,
* and bi_private set to the r10bio.
* For recovery, we may actually create several r10bios
* with 2 bios in each, that correspond to the bios in the main one.
* In this case, the subordinate r10bios link back through a
* borrowed master_bio pointer, and the counter in the master
* includes a ref from each subordinate.
*/
/* First, we decide what to do and set ->bi_end_io
* To end_sync_read if we want to read, and
* end_sync_write if we will want to write.
*/
max_sync = RESYNC_PAGES << (PAGE_SHIFT-9);
if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
/* recovery... the complicated one */
int j;
r10_bio = NULL;
for (i = 0 ; i < conf->geo.raid_disks; i++) {
int still_degraded;
struct r10bio *rb2;
sector_t sect;
int must_sync;
int any_working;
struct raid10_info *mirror = &conf->mirrors[i];
struct md_rdev *mrdev, *mreplace;
rcu_read_lock();
mrdev = rcu_dereference(mirror->rdev);
mreplace = rcu_dereference(mirror->replacement);
if (mrdev && (test_bit(Faulty, &mrdev->flags) ||
test_bit(In_sync, &mrdev->flags)))
mrdev = NULL;
if (mreplace && test_bit(Faulty, &mreplace->flags))
mreplace = NULL;
if (!mrdev && !mreplace) {
rcu_read_unlock();
continue;
}
still_degraded = 0;
/* want to reconstruct this device */
rb2 = r10_bio;
sect = raid10_find_virt(conf, sector_nr, i);
if (sect >= mddev->resync_max_sectors) {
/* last stripe is not complete - don't
* try to recover this sector.
*/
rcu_read_unlock();
continue;
}
/* Unless we are doing a full sync, or a replacement
* we only need to recover the block if it is set in
* the bitmap
*/
must_sync = md_bitmap_start_sync(mddev->bitmap, sect,
&sync_blocks, 1);
if (sync_blocks < max_sync)
max_sync = sync_blocks;
if (!must_sync &&
mreplace == NULL &&
!conf->fullsync) {
/* yep, skip the sync_blocks here, but don't assume
* that there will never be anything to do here
*/
chunks_skipped = -1;
rcu_read_unlock();
continue;
}
if (mrdev)
atomic_inc(&mrdev->nr_pending);
if (mreplace)
atomic_inc(&mreplace->nr_pending);
rcu_read_unlock();
r10_bio = raid10_alloc_init_r10buf(conf);
r10_bio->state = 0;
raise_barrier(conf, rb2 != NULL);
atomic_set(&r10_bio->remaining, 0);
r10_bio->master_bio = (struct bio*)rb2;
if (rb2)
atomic_inc(&rb2->remaining);
r10_bio->mddev = mddev;
set_bit(R10BIO_IsRecover, &r10_bio->state);
r10_bio->sector = sect;
raid10_find_phys(conf, r10_bio);
/* Need to check if the array will still be
* degraded
*/
rcu_read_lock();
for (j = 0; j < conf->geo.raid_disks; j++) {
struct md_rdev *rdev = rcu_dereference(
conf->mirrors[j].rdev);
if (rdev == NULL || test_bit(Faulty, &rdev->flags)) {
still_degraded = 1;
break;
}
}
must_sync = md_bitmap_start_sync(mddev->bitmap, sect,
&sync_blocks, still_degraded);
any_working = 0;
for (j=0; j<conf->copies;j++) {
int k;
int d = r10_bio->devs[j].devnum;
sector_t from_addr, to_addr;
struct md_rdev *rdev =
rcu_dereference(conf->mirrors[d].rdev);
sector_t sector, first_bad;
int bad_sectors;
if (!rdev ||
!test_bit(In_sync, &rdev->flags))
continue;
/* This is where we read from */
any_working = 1;
sector = r10_bio->devs[j].addr;
if (is_badblock(rdev, sector, max_sync,
&first_bad, &bad_sectors)) {
if (first_bad > sector)
max_sync = first_bad - sector;
else {
bad_sectors -= (sector
- first_bad);
if (max_sync > bad_sectors)
max_sync = bad_sectors;
continue;
}
}
bio = r10_bio->devs[0].bio;
bio->bi_next = biolist;
biolist = bio;
bio->bi_end_io = end_sync_read;
bio->bi_opf = REQ_OP_READ;
if (test_bit(FailFast, &rdev->flags))
bio->bi_opf |= MD_FAILFAST;
from_addr = r10_bio->devs[j].addr;
bio->bi_iter.bi_sector = from_addr +
rdev->data_offset;
bio_set_dev(bio, rdev->bdev);
atomic_inc(&rdev->nr_pending);
/* and we write to 'i' (if not in_sync) */
for (k=0; k<conf->copies; k++)
if (r10_bio->devs[k].devnum == i)
break;
BUG_ON(k == conf->copies);
to_addr = r10_bio->devs[k].addr;
r10_bio->devs[0].devnum = d;
r10_bio->devs[0].addr = from_addr;
r10_bio->devs[1].devnum = i;
r10_bio->devs[1].addr = to_addr;
if (mrdev) {
bio = r10_bio->devs[1].bio;
bio->bi_next = biolist;
biolist = bio;
bio->bi_end_io = end_sync_write;
bio->bi_opf = REQ_OP_WRITE;
bio->bi_iter.bi_sector = to_addr
+ mrdev->data_offset;
bio_set_dev(bio, mrdev->bdev);
atomic_inc(&r10_bio->remaining);
} else
r10_bio->devs[1].bio->bi_end_io = NULL;
/* and maybe write to replacement */
bio = r10_bio->devs[1].repl_bio;
if (bio)
bio->bi_end_io = NULL;
/* Note: if replace is not NULL, then bio
* cannot be NULL as r10buf_pool_alloc will
* have allocated it.
*/
if (!mreplace)
break;
bio->bi_next = biolist;
biolist = bio;
bio->bi_end_io = end_sync_write;
bio->bi_opf = REQ_OP_WRITE;
bio->bi_iter.bi_sector = to_addr +
mreplace->data_offset;
bio_set_dev(bio, mreplace->bdev);
atomic_inc(&r10_bio->remaining);
break;
}
rcu_read_unlock();
if (j == conf->copies) {
/* Cannot recover, so abort the recovery or
* record a bad block */
if (any_working) {
/* problem is that there are bad blocks
* on other device(s)
*/
int k;
for (k = 0; k < conf->copies; k++)
if (r10_bio->devs[k].devnum == i)
break;
if (mrdev && !test_bit(In_sync,
&mrdev->flags)
&& !rdev_set_badblocks(
mrdev,
r10_bio->devs[k].addr,
max_sync, 0))
any_working = 0;
if (mreplace &&
!rdev_set_badblocks(
mreplace,
r10_bio->devs[k].addr,
max_sync, 0))
any_working = 0;
}
if (!any_working) {
if (!test_and_set_bit(MD_RECOVERY_INTR,
&mddev->recovery))
pr_warn("md/raid10:%s: insufficient working devices for recovery.\n",
mdname(mddev));
mirror->recovery_disabled
= mddev->recovery_disabled;
} else {
error_disk = i;
}
put_buf(r10_bio);
if (rb2)
atomic_dec(&rb2->remaining);
r10_bio = rb2;
if (mrdev)
rdev_dec_pending(mrdev, mddev);
if (mreplace)
rdev_dec_pending(mreplace, mddev);
break;
}
if (mrdev)
rdev_dec_pending(mrdev, mddev);
if (mreplace)
rdev_dec_pending(mreplace, mddev);
if (r10_bio->devs[0].bio->bi_opf & MD_FAILFAST) {
/* Only want this if there is elsewhere to
* read from. 'j' is currently the first
* readable copy.
*/
int targets = 1;
for (; j < conf->copies; j++) {
int d = r10_bio->devs[j].devnum;
if (conf->mirrors[d].rdev &&
test_bit(In_sync,
&conf->mirrors[d].rdev->flags))
targets++;
}
if (targets == 1)
r10_bio->devs[0].bio->bi_opf
&= ~MD_FAILFAST;
}
}
if (biolist == NULL) {
while (r10_bio) {
struct r10bio *rb2 = r10_bio;
r10_bio = (struct r10bio*) rb2->master_bio;
rb2->master_bio = NULL;
put_buf(rb2);
}
goto giveup;
}
} else {
/* resync. Schedule a read for every block at this virt offset */
int count = 0;
/*
* Since curr_resync_completed could probably not update in
* time, and we will set cluster_sync_low based on it.
* Let's check against "sector_nr + 2 * RESYNC_SECTORS" for
* safety reason, which ensures curr_resync_completed is
* updated in bitmap_cond_end_sync.
*/
md_bitmap_cond_end_sync(mddev->bitmap, sector_nr,
mddev_is_clustered(mddev) &&
(sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high));
if (!md_bitmap_start_sync(mddev->bitmap, sector_nr,
&sync_blocks, mddev->degraded) &&
!conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED,
&mddev->recovery)) {
/* We can skip this block */
*skipped = 1;
return sync_blocks + sectors_skipped;
}
if (sync_blocks < max_sync)
max_sync = sync_blocks;
r10_bio = raid10_alloc_init_r10buf(conf);
r10_bio->state = 0;
r10_bio->mddev = mddev;
atomic_set(&r10_bio->remaining, 0);
raise_barrier(conf, 0);
conf->next_resync = sector_nr;
r10_bio->master_bio = NULL;
r10_bio->sector = sector_nr;
set_bit(R10BIO_IsSync, &r10_bio->state);
raid10_find_phys(conf, r10_bio);
r10_bio->sectors = (sector_nr | chunk_mask) - sector_nr + 1;
for (i = 0; i < conf->copies; i++) {
int d = r10_bio->devs[i].devnum;
sector_t first_bad, sector;
int bad_sectors;
struct md_rdev *rdev;
if (r10_bio->devs[i].repl_bio)
r10_bio->devs[i].repl_bio->bi_end_io = NULL;
bio = r10_bio->devs[i].bio;
bio->bi_status = BLK_STS_IOERR;
rcu_read_lock();
rdev = rcu_dereference(conf->mirrors[d].rdev);
if (rdev == NULL || test_bit(Faulty, &rdev->flags)) {
rcu_read_unlock();
continue;
}
sector = r10_bio->devs[i].addr;
if (is_badblock(rdev, sector, max_sync,
&first_bad, &bad_sectors)) {
if (first_bad > sector)
max_sync = first_bad - sector;
else {
bad_sectors -= (sector - first_bad);
if (max_sync > bad_sectors)
max_sync = bad_sectors;
rcu_read_unlock();
continue;
}
}
atomic_inc(&rdev->nr_pending);
atomic_inc(&r10_bio->remaining);
bio->bi_next = biolist;
biolist = bio;
bio->bi_end_io = end_sync_read;
bio->bi_opf = REQ_OP_READ;
if (test_bit(FailFast, &rdev->flags))
bio->bi_opf |= MD_FAILFAST;
bio->bi_iter.bi_sector = sector + rdev->data_offset;
bio_set_dev(bio, rdev->bdev);
count++;
rdev = rcu_dereference(conf->mirrors[d].replacement);
if (rdev == NULL || test_bit(Faulty, &rdev->flags)) {
rcu_read_unlock();
continue;
}
atomic_inc(&rdev->nr_pending);
/* Need to set up for writing to the replacement */
bio = r10_bio->devs[i].repl_bio;
bio->bi_status = BLK_STS_IOERR;
sector = r10_bio->devs[i].addr;
bio->bi_next = biolist;
biolist = bio;
bio->bi_end_io = end_sync_write;
bio->bi_opf = REQ_OP_WRITE;
if (test_bit(FailFast, &rdev->flags))
bio->bi_opf |= MD_FAILFAST;
bio->bi_iter.bi_sector = sector + rdev->data_offset;
bio_set_dev(bio, rdev->bdev);
count++;
rcu_read_unlock();
}
if (count < 2) {
for (i=0; i<conf->copies; i++) {
int d = r10_bio->devs[i].devnum;
if (r10_bio->devs[i].bio->bi_end_io)
rdev_dec_pending(conf->mirrors[d].rdev,
mddev);
if (r10_bio->devs[i].repl_bio &&
r10_bio->devs[i].repl_bio->bi_end_io)
rdev_dec_pending(
conf->mirrors[d].replacement,
mddev);
}
put_buf(r10_bio);
biolist = NULL;
goto giveup;
}
}
nr_sectors = 0;
if (sector_nr + max_sync < max_sector)
max_sector = sector_nr + max_sync;
do {
struct page *page;
int len = PAGE_SIZE;
if (sector_nr + (len>>9) > max_sector)
len = (max_sector - sector_nr) << 9;
if (len == 0)
break;
for (bio= biolist ; bio ; bio=bio->bi_next) {
struct resync_pages *rp = get_resync_pages(bio);
page = resync_fetch_page(rp, page_idx);
if (WARN_ON(!bio_add_page(bio, page, len, 0))) {
bio->bi_status = BLK_STS_RESOURCE;
bio_endio(bio);
goto giveup;
}
}
nr_sectors += len>>9;
sector_nr += len>>9;
} while (++page_idx < RESYNC_PAGES);
r10_bio->sectors = nr_sectors;
if (mddev_is_clustered(mddev) &&
test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
/* It is resync not recovery */
if (conf->cluster_sync_high < sector_nr + nr_sectors) {
conf->cluster_sync_low = mddev->curr_resync_completed;
raid10_set_cluster_sync_high(conf);
/* Send resync message */
md_cluster_ops->resync_info_update(mddev,
conf->cluster_sync_low,
conf->cluster_sync_high);
}
} else if (mddev_is_clustered(mddev)) {
/* This is recovery not resync */
sector_t sect_va1, sect_va2;
bool broadcast_msg = false;
for (i = 0; i < conf->geo.raid_disks; i++) {
/*
* sector_nr is a device address for recovery, so we
* need translate it to array address before compare
* with cluster_sync_high.
*/
sect_va1 = raid10_find_virt(conf, sector_nr, i);
if (conf->cluster_sync_high < sect_va1 + nr_sectors) {
broadcast_msg = true;
/*
* curr_resync_completed is similar as
* sector_nr, so make the translation too.
*/
sect_va2 = raid10_find_virt(conf,
mddev->curr_resync_completed, i);
if (conf->cluster_sync_low == 0 ||
conf->cluster_sync_low > sect_va2)
conf->cluster_sync_low = sect_va2;
}
}
if (broadcast_msg) {
raid10_set_cluster_sync_high(conf);
md_cluster_ops->resync_info_update(mddev,
conf->cluster_sync_low,
conf->cluster_sync_high);
}
}
while (biolist) {
bio = biolist;
biolist = biolist->bi_next;
bio->bi_next = NULL;
r10_bio = get_resync_r10bio(bio);
r10_bio->sectors = nr_sectors;
if (bio->bi_end_io == end_sync_read) {
md_sync_acct_bio(bio, nr_sectors);
bio->bi_status = 0;
submit_bio_noacct(bio);
}
}
if (sectors_skipped)
/* pretend they weren't skipped, it makes
* no important difference in this case
*/
md_done_sync(mddev, sectors_skipped, 1);
return sectors_skipped + nr_sectors;
giveup:
/* There is nowhere to write, so all non-sync
* drives must be failed or in resync, all drives
* have a bad block, so try the next chunk...
*/
if (sector_nr + max_sync < max_sector)
max_sector = sector_nr + max_sync;
sectors_skipped += (max_sector - sector_nr);
chunks_skipped ++;
sector_nr = max_sector;
goto skipped;
}
static sector_t
raid10_size(struct mddev *mddev, sector_t sectors, int raid_disks)
{
sector_t size;
struct r10conf *conf = mddev->private;
if (!raid_disks)
raid_disks = min(conf->geo.raid_disks,
conf->prev.raid_disks);
if (!sectors)
sectors = conf->dev_sectors;
size = sectors >> conf->geo.chunk_shift;
sector_div(size, conf->geo.far_copies);
size = size * raid_disks;
sector_div(size, conf->geo.near_copies);
return size << conf->geo.chunk_shift;
}
static void calc_sectors(struct r10conf *conf, sector_t size)
{
/* Calculate the number of sectors-per-device that will
* actually be used, and set conf->dev_sectors and
* conf->stride
*/
size = size >> conf->geo.chunk_shift;
sector_div(size, conf->geo.far_copies);
size = size * conf->geo.raid_disks;
sector_div(size, conf->geo.near_copies);
/* 'size' is now the number of chunks in the array */
/* calculate "used chunks per device" */
size = size * conf->copies;
/* We need to round up when dividing by raid_disks to
* get the stride size.
*/
size = DIV_ROUND_UP_SECTOR_T(size, conf->geo.raid_disks);
conf->dev_sectors = size << conf->geo.chunk_shift;
if (conf->geo.far_offset)
conf->geo.stride = 1 << conf->geo.chunk_shift;
else {
sector_div(size, conf->geo.far_copies);
conf->geo.stride = size << conf->geo.chunk_shift;
}
}
enum geo_type {geo_new, geo_old, geo_start};
static int setup_geo(struct geom *geo, struct mddev *mddev, enum geo_type new)
{
int nc, fc, fo;
int layout, chunk, disks;
switch (new) {
case geo_old:
layout = mddev->layout;
chunk = mddev->chunk_sectors;
disks = mddev->raid_disks - mddev->delta_disks;
break;
case geo_new:
layout = mddev->new_layout;
chunk = mddev->new_chunk_sectors;
disks = mddev->raid_disks;
break;
default: /* avoid 'may be unused' warnings */
case geo_start: /* new when starting reshape - raid_disks not
* updated yet. */
layout = mddev->new_layout;
chunk = mddev->new_chunk_sectors;
disks = mddev->raid_disks + mddev->delta_disks;
break;
}
if (layout >> 19)
return -1;
if (chunk < (PAGE_SIZE >> 9) ||
!is_power_of_2(chunk))
return -2;
nc = layout & 255;
fc = (layout >> 8) & 255;
fo = layout & (1<<16);
geo->raid_disks = disks;
geo->near_copies = nc;
geo->far_copies = fc;
geo->far_offset = fo;
switch (layout >> 17) {
case 0: /* original layout. simple but not always optimal */
geo->far_set_size = disks;
break;
case 1: /* "improved" layout which was buggy. Hopefully no-one is
* actually using this, but leave code here just in case.*/
geo->far_set_size = disks/fc;
WARN(geo->far_set_size < fc,
"This RAID10 layout does not provide data safety - please backup and create new array\n");
break;
case 2: /* "improved" layout fixed to match documentation */
geo->far_set_size = fc * nc;
break;
default: /* Not a valid layout */
return -1;
}
geo->chunk_mask = chunk - 1;
geo->chunk_shift = ffz(~chunk);
return nc*fc;
}
static void raid10_free_conf(struct r10conf *conf)
{
if (!conf)
return;
mempool_exit(&conf->r10bio_pool);
kfree(conf->mirrors);
kfree(conf->mirrors_old);
kfree(conf->mirrors_new);
safe_put_page(conf->tmppage);
bioset_exit(&conf->bio_split);
kfree(conf);
}
static struct r10conf *setup_conf(struct mddev *mddev)
{
struct r10conf *conf = NULL;
int err = -EINVAL;
struct geom geo;
int copies;
copies = setup_geo(&geo, mddev, geo_new);
if (copies == -2) {
pr_warn("md/raid10:%s: chunk size must be at least PAGE_SIZE(%ld) and be a power of 2.\n",
mdname(mddev), PAGE_SIZE);
goto out;
}
if (copies < 2 || copies > mddev->raid_disks) {
pr_warn("md/raid10:%s: unsupported raid10 layout: 0x%8x\n",
mdname(mddev), mddev->new_layout);
goto out;
}
err = -ENOMEM;
conf = kzalloc(sizeof(struct r10conf), GFP_KERNEL);
if (!conf)
goto out;
/* FIXME calc properly */
conf->mirrors = kcalloc(mddev->raid_disks + max(0, -mddev->delta_disks),
sizeof(struct raid10_info),
GFP_KERNEL);
if (!conf->mirrors)
goto out;
conf->tmppage = alloc_page(GFP_KERNEL);
if (!conf->tmppage)
goto out;
conf->geo = geo;
conf->copies = copies;
err = mempool_init(&conf->r10bio_pool, NR_RAID_BIOS, r10bio_pool_alloc,
rbio_pool_free, conf);
if (err)
goto out;
err = bioset_init(&conf->bio_split, BIO_POOL_SIZE, 0, 0);
if (err)
goto out;
calc_sectors(conf, mddev->dev_sectors);
if (mddev->reshape_position == MaxSector) {
conf->prev = conf->geo;
conf->reshape_progress = MaxSector;
} else {
if (setup_geo(&conf->prev, mddev, geo_old) != conf->copies) {
err = -EINVAL;
goto out;
}
conf->reshape_progress = mddev->reshape_position;
if (conf->prev.far_offset)
conf->prev.stride = 1 << conf->prev.chunk_shift;
else
/* far_copies must be 1 */
conf->prev.stride = conf->dev_sectors;
}
conf->reshape_safe = conf->reshape_progress;
spin_lock_init(&conf->device_lock);
INIT_LIST_HEAD(&conf->retry_list);
INIT_LIST_HEAD(&conf->bio_end_io_list);
seqlock_init(&conf->resync_lock);
init_waitqueue_head(&conf->wait_barrier);
atomic_set(&conf->nr_pending, 0);
err = -ENOMEM;
rcu_assign_pointer(conf->thread,
md_register_thread(raid10d, mddev, "raid10"));
if (!conf->thread)
goto out;
conf->mddev = mddev;
return conf;
out:
raid10_free_conf(conf);
return ERR_PTR(err);
}
static void raid10_set_io_opt(struct r10conf *conf)
{
int raid_disks = conf->geo.raid_disks;
if (!(conf->geo.raid_disks % conf->geo.near_copies))
raid_disks /= conf->geo.near_copies;
blk_queue_io_opt(conf->mddev->queue, (conf->mddev->chunk_sectors << 9) *
raid_disks);
}
static int raid10_run(struct mddev *mddev)
{
struct r10conf *conf;
int i, disk_idx;
struct raid10_info *disk;
struct md_rdev *rdev;
sector_t size;
sector_t min_offset_diff = 0;
int first = 1;
if (mddev_init_writes_pending(mddev) < 0)
return -ENOMEM;
if (mddev->private == NULL) {
conf = setup_conf(mddev);
if (IS_ERR(conf))
return PTR_ERR(conf);
mddev->private = conf;
}
conf = mddev->private;
if (!conf)
goto out;
rcu_assign_pointer(mddev->thread, conf->thread);
rcu_assign_pointer(conf->thread, NULL);
if (mddev_is_clustered(conf->mddev)) {
int fc, fo;
fc = (mddev->layout >> 8) & 255;
fo = mddev->layout & (1<<16);
if (fc > 1 || fo > 0) {
pr_err("only near layout is supported by clustered"
" raid10\n");
goto out_free_conf;
}
}
if (mddev->queue) {
blk_queue_max_write_zeroes_sectors(mddev->queue, 0);
blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9);
raid10_set_io_opt(conf);
}
rdev_for_each(rdev, mddev) {
long long diff;
disk_idx = rdev->raid_disk;
if (disk_idx < 0)
continue;
if (disk_idx >= conf->geo.raid_disks &&
disk_idx >= conf->prev.raid_disks)
continue;
disk = conf->mirrors + disk_idx;
if (test_bit(Replacement, &rdev->flags)) {
if (disk->replacement)
goto out_free_conf;
disk->replacement = rdev;
} else {
if (disk->rdev)
goto out_free_conf;
disk->rdev = rdev;
}
diff = (rdev->new_data_offset - rdev->data_offset);
if (!mddev->reshape_backwards)
diff = -diff;
if (diff < 0)
diff = 0;
if (first || diff < min_offset_diff)
min_offset_diff = diff;
if (mddev->gendisk)
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
disk->head_position = 0;
first = 0;
}
/* need to check that every block has at least one working mirror */
if (!enough(conf, -1)) {
pr_err("md/raid10:%s: not enough operational mirrors.\n",
mdname(mddev));
goto out_free_conf;
}
if (conf->reshape_progress != MaxSector) {
/* must ensure that shape change is supported */
if (conf->geo.far_copies != 1 &&
conf->geo.far_offset == 0)
goto out_free_conf;
if (conf->prev.far_copies != 1 &&
conf->prev.far_offset == 0)
goto out_free_conf;
}
mddev->degraded = 0;
for (i = 0;
i < conf->geo.raid_disks
|| i < conf->prev.raid_disks;
i++) {
disk = conf->mirrors + i;
if (!disk->rdev && disk->replacement) {
/* The replacement is all we have - use it */
disk->rdev = disk->replacement;
disk->replacement = NULL;
clear_bit(Replacement, &disk->rdev->flags);
}
if (!disk->rdev ||
!test_bit(In_sync, &disk->rdev->flags)) {
disk->head_position = 0;
mddev->degraded++;
if (disk->rdev &&
disk->rdev->saved_raid_disk < 0)
conf->fullsync = 1;
}
if (disk->replacement &&
!test_bit(In_sync, &disk->replacement->flags) &&
disk->replacement->saved_raid_disk < 0) {
conf->fullsync = 1;
}
disk->recovery_disabled = mddev->recovery_disabled - 1;
}
if (mddev->recovery_cp != MaxSector)
pr_notice("md/raid10:%s: not clean -- starting background reconstruction\n",
mdname(mddev));
pr_info("md/raid10:%s: active with %d out of %d devices\n",
mdname(mddev), conf->geo.raid_disks - mddev->degraded,
conf->geo.raid_disks);
/*
* Ok, everything is just fine now
*/
mddev->dev_sectors = conf->dev_sectors;
size = raid10_size(mddev, 0, 0);
md_set_array_sectors(mddev, size);
mddev->resync_max_sectors = size;
set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
if (md_integrity_register(mddev))
goto out_free_conf;
if (conf->reshape_progress != MaxSector) {
unsigned long before_length, after_length;
before_length = ((1 << conf->prev.chunk_shift) *
conf->prev.far_copies);
after_length = ((1 << conf->geo.chunk_shift) *
conf->geo.far_copies);
if (max(before_length, after_length) > min_offset_diff) {
/* This cannot work */
pr_warn("md/raid10: offset difference not enough to continue reshape\n");
goto out_free_conf;
}
conf->offset_diff = min_offset_diff;
clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
rcu_assign_pointer(mddev->sync_thread,
md_register_thread(md_do_sync, mddev, "reshape"));
if (!mddev->sync_thread)
goto out_free_conf;
}
return 0;
out_free_conf:
md_unregister_thread(mddev, &mddev->thread);
raid10_free_conf(conf);
mddev->private = NULL;
out:
return -EIO;
}
static void raid10_free(struct mddev *mddev, void *priv)
{
raid10_free_conf(priv);
}
static void raid10_quiesce(struct mddev *mddev, int quiesce)
{
struct r10conf *conf = mddev->private;
if (quiesce)
raise_barrier(conf, 0);
else
lower_barrier(conf);
}
static int raid10_resize(struct mddev *mddev, sector_t sectors)
{
/* Resize of 'far' arrays is not supported.
* For 'near' and 'offset' arrays we can set the
* number of sectors used to be an appropriate multiple
* of the chunk size.
* For 'offset', this is far_copies*chunksize.
* For 'near' the multiplier is the LCM of
* near_copies and raid_disks.
* So if far_copies > 1 && !far_offset, fail.
* Else find LCM(raid_disks, near_copy)*far_copies and
* multiply by chunk_size. Then round to this number.
* This is mostly done by raid10_size()
*/
struct r10conf *conf = mddev->private;
sector_t oldsize, size;
if (mddev->reshape_position != MaxSector)
return -EBUSY;
if (conf->geo.far_copies > 1 && !conf->geo.far_offset)
return -EINVAL;
oldsize = raid10_size(mddev, 0, 0);
size = raid10_size(mddev, sectors, 0);
if (mddev->external_size &&
mddev->array_sectors > size)
return -EINVAL;
if (mddev->bitmap) {
int ret = md_bitmap_resize(mddev->bitmap, size, 0, 0);
if (ret)
return ret;
}
md_set_array_sectors(mddev, size);
if (sectors > mddev->dev_sectors &&
mddev->recovery_cp > oldsize) {
mddev->recovery_cp = oldsize;
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
}
calc_sectors(conf, sectors);
mddev->dev_sectors = conf->dev_sectors;
mddev->resync_max_sectors = size;
return 0;
}
static void *raid10_takeover_raid0(struct mddev *mddev, sector_t size, int devs)
{
struct md_rdev *rdev;
struct r10conf *conf;
if (mddev->degraded > 0) {
pr_warn("md/raid10:%s: Error: degraded raid0!\n",
mdname(mddev));
return ERR_PTR(-EINVAL);
}
sector_div(size, devs);
/* Set new parameters */
mddev->new_level = 10;
/* new layout: far_copies = 1, near_copies = 2 */
mddev->new_layout = (1<<8) + 2;
mddev->new_chunk_sectors = mddev->chunk_sectors;
mddev->delta_disks = mddev->raid_disks;
mddev->raid_disks *= 2;
/* make sure it will be not marked as dirty */
mddev->recovery_cp = MaxSector;
mddev->dev_sectors = size;
conf = setup_conf(mddev);
if (!IS_ERR(conf)) {
rdev_for_each(rdev, mddev)
if (rdev->raid_disk >= 0) {
rdev->new_raid_disk = rdev->raid_disk * 2;
rdev->sectors = size;
}
}
return conf;
}
static void *raid10_takeover(struct mddev *mddev)
{
struct r0conf *raid0_conf;
/* raid10 can take over:
* raid0 - providing it has only two drives
*/
if (mddev->level == 0) {
/* for raid0 takeover only one zone is supported */
raid0_conf = mddev->private;
if (raid0_conf->nr_strip_zones > 1) {
pr_warn("md/raid10:%s: cannot takeover raid 0 with more than one zone.\n",
mdname(mddev));
return ERR_PTR(-EINVAL);
}
return raid10_takeover_raid0(mddev,
raid0_conf->strip_zone->zone_end,
raid0_conf->strip_zone->nb_dev);
}
return ERR_PTR(-EINVAL);
}
static int raid10_check_reshape(struct mddev *mddev)
{
/* Called when there is a request to change
* - layout (to ->new_layout)
* - chunk size (to ->new_chunk_sectors)
* - raid_disks (by delta_disks)
* or when trying to restart a reshape that was ongoing.
*
* We need to validate the request and possibly allocate
* space if that might be an issue later.
*
* Currently we reject any reshape of a 'far' mode array,
* allow chunk size to change if new is generally acceptable,
* allow raid_disks to increase, and allow
* a switch between 'near' mode and 'offset' mode.
*/
struct r10conf *conf = mddev->private;
struct geom geo;
if (conf->geo.far_copies != 1 && !conf->geo.far_offset)
return -EINVAL;
if (setup_geo(&geo, mddev, geo_start) != conf->copies)
/* mustn't change number of copies */
return -EINVAL;
if (geo.far_copies > 1 && !geo.far_offset)
/* Cannot switch to 'far' mode */
return -EINVAL;
if (mddev->array_sectors & geo.chunk_mask)
/* not factor of array size */
return -EINVAL;
if (!enough(conf, -1))
return -EINVAL;
kfree(conf->mirrors_new);
conf->mirrors_new = NULL;
if (mddev->delta_disks > 0) {
/* allocate new 'mirrors' list */
conf->mirrors_new =
kcalloc(mddev->raid_disks + mddev->delta_disks,
sizeof(struct raid10_info),
GFP_KERNEL);
if (!conf->mirrors_new)
return -ENOMEM;
}
return 0;
}
/*
* Need to check if array has failed when deciding whether to:
* - start an array
* - remove non-faulty devices
* - add a spare
* - allow a reshape
* This determination is simple when no reshape is happening.
* However if there is a reshape, we need to carefully check
* both the before and after sections.
* This is because some failed devices may only affect one
* of the two sections, and some non-in_sync devices may
* be insync in the section most affected by failed devices.
*/
static int calc_degraded(struct r10conf *conf)
{
int degraded, degraded2;
int i;
rcu_read_lock();
degraded = 0;
/* 'prev' section first */
for (i = 0; i < conf->prev.raid_disks; i++) {
struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
if (!rdev || test_bit(Faulty, &rdev->flags))
degraded++;
else if (!test_bit(In_sync, &rdev->flags))
/* When we can reduce the number of devices in
* an array, this might not contribute to
* 'degraded'. It does now.
*/
degraded++;
}
rcu_read_unlock();
if (conf->geo.raid_disks == conf->prev.raid_disks)
return degraded;
rcu_read_lock();
degraded2 = 0;
for (i = 0; i < conf->geo.raid_disks; i++) {
struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
if (!rdev || test_bit(Faulty, &rdev->flags))
degraded2++;
else if (!test_bit(In_sync, &rdev->flags)) {
/* If reshape is increasing the number of devices,
* this section has already been recovered, so
* it doesn't contribute to degraded.
* else it does.
*/
if (conf->geo.raid_disks <= conf->prev.raid_disks)
degraded2++;
}
}
rcu_read_unlock();
if (degraded2 > degraded)
return degraded2;
return degraded;
}
static int raid10_start_reshape(struct mddev *mddev)
{
/* A 'reshape' has been requested. This commits
* the various 'new' fields and sets MD_RECOVER_RESHAPE
* This also checks if there are enough spares and adds them
* to the array.
* We currently require enough spares to make the final
* array non-degraded. We also require that the difference
* between old and new data_offset - on each device - is
* enough that we never risk over-writing.
*/
unsigned long before_length, after_length;
sector_t min_offset_diff = 0;
int first = 1;
struct geom new;
struct r10conf *conf = mddev->private;
struct md_rdev *rdev;
int spares = 0;
int ret;
if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
return -EBUSY;
if (setup_geo(&new, mddev, geo_start) != conf->copies)
return -EINVAL;
before_length = ((1 << conf->prev.chunk_shift) *
conf->prev.far_copies);
after_length = ((1 << conf->geo.chunk_shift) *
conf->geo.far_copies);
rdev_for_each(rdev, mddev) {
if (!test_bit(In_sync, &rdev->flags)
&& !test_bit(Faulty, &rdev->flags))
spares++;
if (rdev->raid_disk >= 0) {
long long diff = (rdev->new_data_offset
- rdev->data_offset);
if (!mddev->reshape_backwards)
diff = -diff;
if (diff < 0)
diff = 0;
if (first || diff < min_offset_diff)
min_offset_diff = diff;
first = 0;
}
}
if (max(before_length, after_length) > min_offset_diff)
return -EINVAL;
if (spares < mddev->delta_disks)
return -EINVAL;
conf->offset_diff = min_offset_diff;
spin_lock_irq(&conf->device_lock);
if (conf->mirrors_new) {
memcpy(conf->mirrors_new, conf->mirrors,
sizeof(struct raid10_info)*conf->prev.raid_disks);
smp_mb();
kfree(conf->mirrors_old);
conf->mirrors_old = conf->mirrors;
conf->mirrors = conf->mirrors_new;
conf->mirrors_new = NULL;
}
setup_geo(&conf->geo, mddev, geo_start);
smp_mb();
if (mddev->reshape_backwards) {
sector_t size = raid10_size(mddev, 0, 0);
if (size < mddev->array_sectors) {
spin_unlock_irq(&conf->device_lock);
pr_warn("md/raid10:%s: array size must be reduce before number of disks\n",
mdname(mddev));
return -EINVAL;
}
mddev->resync_max_sectors = size;
conf->reshape_progress = size;
} else
conf->reshape_progress = 0;
conf->reshape_safe = conf->reshape_progress;
spin_unlock_irq(&conf->device_lock);
if (mddev->delta_disks && mddev->bitmap) {
struct mdp_superblock_1 *sb = NULL;
sector_t oldsize, newsize;
oldsize = raid10_size(mddev, 0, 0);
newsize = raid10_size(mddev, 0, conf->geo.raid_disks);
if (!mddev_is_clustered(mddev)) {
ret = md_bitmap_resize(mddev->bitmap, newsize, 0, 0);
if (ret)
goto abort;
else
goto out;
}
rdev_for_each(rdev, mddev) {
if (rdev->raid_disk > -1 &&
!test_bit(Faulty, &rdev->flags))
sb = page_address(rdev->sb_page);
}
/*
* some node is already performing reshape, and no need to
* call md_bitmap_resize again since it should be called when
* receiving BITMAP_RESIZE msg
*/
if ((sb && (le32_to_cpu(sb->feature_map) &
MD_FEATURE_RESHAPE_ACTIVE)) || (oldsize == newsize))
goto out;
ret = md_bitmap_resize(mddev->bitmap, newsize, 0, 0);
if (ret)
goto abort;
ret = md_cluster_ops->resize_bitmaps(mddev, newsize, oldsize);
if (ret) {
md_bitmap_resize(mddev->bitmap, oldsize, 0, 0);
goto abort;
}
}
out:
if (mddev->delta_disks > 0) {
rdev_for_each(rdev, mddev)
if (rdev->raid_disk < 0 &&
!test_bit(Faulty, &rdev->flags)) {
if (raid10_add_disk(mddev, rdev) == 0) {
if (rdev->raid_disk >=
conf->prev.raid_disks)
set_bit(In_sync, &rdev->flags);
else
rdev->recovery_offset = 0;
/* Failure here is OK */
sysfs_link_rdev(mddev, rdev);
}
} else if (rdev->raid_disk >= conf->prev.raid_disks
&& !test_bit(Faulty, &rdev->flags)) {
/* This is a spare that was manually added */
set_bit(In_sync, &rdev->flags);
}
}
/* When a reshape changes the number of devices,
* ->degraded is measured against the larger of the
* pre and post numbers.
*/
spin_lock_irq(&conf->device_lock);
mddev->degraded = calc_degraded(conf);
spin_unlock_irq(&conf->device_lock);
mddev->raid_disks = conf->geo.raid_disks;
mddev->reshape_position = conf->reshape_progress;
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
rcu_assign_pointer(mddev->sync_thread,
md_register_thread(md_do_sync, mddev, "reshape"));
if (!mddev->sync_thread) {
ret = -EAGAIN;
goto abort;
}
conf->reshape_checkpoint = jiffies;
md_wakeup_thread(mddev->sync_thread);
md_new_event();
return 0;
abort:
mddev->recovery = 0;
spin_lock_irq(&conf->device_lock);
conf->geo = conf->prev;
mddev->raid_disks = conf->geo.raid_disks;
rdev_for_each(rdev, mddev)
rdev->new_data_offset = rdev->data_offset;
smp_wmb();
conf->reshape_progress = MaxSector;
conf->reshape_safe = MaxSector;
mddev->reshape_position = MaxSector;
spin_unlock_irq(&conf->device_lock);
return ret;
}
/* Calculate the last device-address that could contain
* any block from the chunk that includes the array-address 's'
* and report the next address.
* i.e. the address returned will be chunk-aligned and after
* any data that is in the chunk containing 's'.
*/
static sector_t last_dev_address(sector_t s, struct geom *geo)
{
s = (s | geo->chunk_mask) + 1;
s >>= geo->chunk_shift;
s *= geo->near_copies;
s = DIV_ROUND_UP_SECTOR_T(s, geo->raid_disks);
s *= geo->far_copies;
s <<= geo->chunk_shift;
return s;
}
/* Calculate the first device-address that could contain
* any block from the chunk that includes the array-address 's'.
* This too will be the start of a chunk
*/
static sector_t first_dev_address(sector_t s, struct geom *geo)
{
s >>= geo->chunk_shift;
s *= geo->near_copies;
sector_div(s, geo->raid_disks);
s *= geo->far_copies;
s <<= geo->chunk_shift;
return s;
}
static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr,
int *skipped)
{
/* We simply copy at most one chunk (smallest of old and new)
* at a time, possibly less if that exceeds RESYNC_PAGES,
* or we hit a bad block or something.
* This might mean we pause for normal IO in the middle of
* a chunk, but that is not a problem as mddev->reshape_position
* can record any location.
*
* If we will want to write to a location that isn't
* yet recorded as 'safe' (i.e. in metadata on disk) then
* we need to flush all reshape requests and update the metadata.
*
* When reshaping forwards (e.g. to more devices), we interpret
* 'safe' as the earliest block which might not have been copied
* down yet. We divide this by previous stripe size and multiply
* by previous stripe length to get lowest device offset that we
* cannot write to yet.
* We interpret 'sector_nr' as an address that we want to write to.
* From this we use last_device_address() to find where we might
* write to, and first_device_address on the 'safe' position.
* If this 'next' write position is after the 'safe' position,
* we must update the metadata to increase the 'safe' position.
*
* When reshaping backwards, we round in the opposite direction
* and perform the reverse test: next write position must not be
* less than current safe position.
*
* In all this the minimum difference in data offsets
* (conf->offset_diff - always positive) allows a bit of slack,
* so next can be after 'safe', but not by more than offset_diff
*
* We need to prepare all the bios here before we start any IO
* to ensure the size we choose is acceptable to all devices.
* The means one for each copy for write-out and an extra one for
* read-in.
* We store the read-in bio in ->master_bio and the others in
* ->devs[x].bio and ->devs[x].repl_bio.
*/
struct r10conf *conf = mddev->private;
struct r10bio *r10_bio;
sector_t next, safe, last;
int max_sectors;
int nr_sectors;
int s;
struct md_rdev *rdev;
int need_flush = 0;
struct bio *blist;
struct bio *bio, *read_bio;
int sectors_done = 0;
struct page **pages;
if (sector_nr == 0) {
/* If restarting in the middle, skip the initial sectors */
if (mddev->reshape_backwards &&
conf->reshape_progress < raid10_size(mddev, 0, 0)) {
sector_nr = (raid10_size(mddev, 0, 0)
- conf->reshape_progress);
} else if (!mddev->reshape_backwards &&
conf->reshape_progress > 0)
sector_nr = conf->reshape_progress;
if (sector_nr) {
mddev->curr_resync_completed = sector_nr;
sysfs_notify_dirent_safe(mddev->sysfs_completed);
*skipped = 1;
return sector_nr;
}
}
/* We don't use sector_nr to track where we are up to
* as that doesn't work well for ->reshape_backwards.
* So just use ->reshape_progress.
*/
if (mddev->reshape_backwards) {
/* 'next' is the earliest device address that we might
* write to for this chunk in the new layout
*/
next = first_dev_address(conf->reshape_progress - 1,
&conf->geo);
/* 'safe' is the last device address that we might read from
* in the old layout after a restart
*/
safe = last_dev_address(conf->reshape_safe - 1,
&conf->prev);
if (next + conf->offset_diff < safe)
need_flush = 1;
last = conf->reshape_progress - 1;
sector_nr = last & ~(sector_t)(conf->geo.chunk_mask
& conf->prev.chunk_mask);
if (sector_nr + RESYNC_SECTORS < last)
sector_nr = last + 1 - RESYNC_SECTORS;
} else {
/* 'next' is after the last device address that we
* might write to for this chunk in the new layout
*/
next = last_dev_address(conf->reshape_progress, &conf->geo);
/* 'safe' is the earliest device address that we might
* read from in the old layout after a restart
*/
safe = first_dev_address(conf->reshape_safe, &conf->prev);
/* Need to update metadata if 'next' might be beyond 'safe'
* as that would possibly corrupt data
*/
if (next > safe + conf->offset_diff)
need_flush = 1;
sector_nr = conf->reshape_progress;
last = sector_nr | (conf->geo.chunk_mask
& conf->prev.chunk_mask);
if (sector_nr + RESYNC_SECTORS <= last)
last = sector_nr + RESYNC_SECTORS - 1;
}
if (need_flush ||
time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
/* Need to update reshape_position in metadata */
wait_barrier(conf, false);
mddev->reshape_position = conf->reshape_progress;
if (mddev->reshape_backwards)
mddev->curr_resync_completed = raid10_size(mddev, 0, 0)
- conf->reshape_progress;
else
mddev->curr_resync_completed = conf->reshape_progress;
conf->reshape_checkpoint = jiffies;
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
md_wakeup_thread(mddev->thread);
wait_event(mddev->sb_wait, mddev->sb_flags == 0 ||
test_bit(MD_RECOVERY_INTR, &mddev->recovery));
if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
allow_barrier(conf);
return sectors_done;
}
conf->reshape_safe = mddev->reshape_position;
allow_barrier(conf);
}
raise_barrier(conf, 0);
read_more:
/* Now schedule reads for blocks from sector_nr to last */
r10_bio = raid10_alloc_init_r10buf(conf);
r10_bio->state = 0;
raise_barrier(conf, 1);
atomic_set(&r10_bio->remaining, 0);
r10_bio->mddev = mddev;
r10_bio->sector = sector_nr;
set_bit(R10BIO_IsReshape, &r10_bio->state);
r10_bio->sectors = last - sector_nr + 1;
rdev = read_balance(conf, r10_bio, &max_sectors);
BUG_ON(!test_bit(R10BIO_Previous, &r10_bio->state));
if (!rdev) {
/* Cannot read from here, so need to record bad blocks
* on all the target devices.
*/
// FIXME
mempool_free(r10_bio, &conf->r10buf_pool);
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
return sectors_done;
}
read_bio = bio_alloc_bioset(rdev->bdev, RESYNC_PAGES, REQ_OP_READ,
GFP_KERNEL, &mddev->bio_set);
read_bio->bi_iter.bi_sector = (r10_bio->devs[r10_bio->read_slot].addr
+ rdev->data_offset);
read_bio->bi_private = r10_bio;
read_bio->bi_end_io = end_reshape_read;
r10_bio->master_bio = read_bio;
r10_bio->read_slot = r10_bio->devs[r10_bio->read_slot].devnum;
/*
* Broadcast RESYNC message to other nodes, so all nodes would not
* write to the region to avoid conflict.
*/
if (mddev_is_clustered(mddev) && conf->cluster_sync_high <= sector_nr) {
struct mdp_superblock_1 *sb = NULL;
int sb_reshape_pos = 0;
conf->cluster_sync_low = sector_nr;
conf->cluster_sync_high = sector_nr + CLUSTER_RESYNC_WINDOW_SECTORS;
sb = page_address(rdev->sb_page);
if (sb) {
sb_reshape_pos = le64_to_cpu(sb->reshape_position);
/*
* Set cluster_sync_low again if next address for array
* reshape is less than cluster_sync_low. Since we can't
* update cluster_sync_low until it has finished reshape.
*/
if (sb_reshape_pos < conf->cluster_sync_low)
conf->cluster_sync_low = sb_reshape_pos;
}
md_cluster_ops->resync_info_update(mddev, conf->cluster_sync_low,
conf->cluster_sync_high);
}
/* Now find the locations in the new layout */
__raid10_find_phys(&conf->geo, r10_bio);
blist = read_bio;
read_bio->bi_next = NULL;
rcu_read_lock();
for (s = 0; s < conf->copies*2; s++) {
struct bio *b;
int d = r10_bio->devs[s/2].devnum;
struct md_rdev *rdev2;
if (s&1) {
rdev2 = rcu_dereference(conf->mirrors[d].replacement);
b = r10_bio->devs[s/2].repl_bio;
} else {
rdev2 = rcu_dereference(conf->mirrors[d].rdev);
b = r10_bio->devs[s/2].bio;
}
if (!rdev2 || test_bit(Faulty, &rdev2->flags))
continue;
bio_set_dev(b, rdev2->bdev);
b->bi_iter.bi_sector = r10_bio->devs[s/2].addr +
rdev2->new_data_offset;
b->bi_end_io = end_reshape_write;
b->bi_opf = REQ_OP_WRITE;
b->bi_next = blist;
blist = b;
}
/* Now add as many pages as possible to all of these bios. */
nr_sectors = 0;
pages = get_resync_pages(r10_bio->devs[0].bio)->pages;
for (s = 0 ; s < max_sectors; s += PAGE_SIZE >> 9) {
struct page *page = pages[s / (PAGE_SIZE >> 9)];
int len = (max_sectors - s) << 9;
if (len > PAGE_SIZE)
len = PAGE_SIZE;
for (bio = blist; bio ; bio = bio->bi_next) {
if (WARN_ON(!bio_add_page(bio, page, len, 0))) {
bio->bi_status = BLK_STS_RESOURCE;
bio_endio(bio);
return sectors_done;
}
}
sector_nr += len >> 9;
nr_sectors += len >> 9;
}
rcu_read_unlock();
r10_bio->sectors = nr_sectors;
/* Now submit the read */
md_sync_acct_bio(read_bio, r10_bio->sectors);
atomic_inc(&r10_bio->remaining);
read_bio->bi_next = NULL;
submit_bio_noacct(read_bio);
sectors_done += nr_sectors;
if (sector_nr <= last)
goto read_more;
lower_barrier(conf);
/* Now that we have done the whole section we can
* update reshape_progress
*/
if (mddev->reshape_backwards)
conf->reshape_progress -= sectors_done;
else
conf->reshape_progress += sectors_done;
return sectors_done;
}
static void end_reshape_request(struct r10bio *r10_bio);
static int handle_reshape_read_error(struct mddev *mddev,
struct r10bio *r10_bio);
static void reshape_request_write(struct mddev *mddev, struct r10bio *r10_bio)
{
/* Reshape read completed. Hopefully we have a block
* to write out.
* If we got a read error then we do sync 1-page reads from
* elsewhere until we find the data - or give up.
*/
struct r10conf *conf = mddev->private;
int s;
if (!test_bit(R10BIO_Uptodate, &r10_bio->state))
if (handle_reshape_read_error(mddev, r10_bio) < 0) {
/* Reshape has been aborted */
md_done_sync(mddev, r10_bio->sectors, 0);
return;
}
/* We definitely have the data in the pages, schedule the
* writes.
*/
atomic_set(&r10_bio->remaining, 1);
for (s = 0; s < conf->copies*2; s++) {
struct bio *b;
int d = r10_bio->devs[s/2].devnum;
struct md_rdev *rdev;
rcu_read_lock();
if (s&1) {
rdev = rcu_dereference(conf->mirrors[d].replacement);
b = r10_bio->devs[s/2].repl_bio;
} else {
rdev = rcu_dereference(conf->mirrors[d].rdev);
b = r10_bio->devs[s/2].bio;
}
if (!rdev || test_bit(Faulty, &rdev->flags)) {
rcu_read_unlock();
continue;
}
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
md_sync_acct_bio(b, r10_bio->sectors);
atomic_inc(&r10_bio->remaining);
b->bi_next = NULL;
submit_bio_noacct(b);
}
end_reshape_request(r10_bio);
}
static void end_reshape(struct r10conf *conf)
{
if (test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery))
return;
spin_lock_irq(&conf->device_lock);
conf->prev = conf->geo;
md_finish_reshape(conf->mddev);
smp_wmb();
conf->reshape_progress = MaxSector;
conf->reshape_safe = MaxSector;
spin_unlock_irq(&conf->device_lock);
if (conf->mddev->queue)
raid10_set_io_opt(conf);
conf->fullsync = 0;
}
static void raid10_update_reshape_pos(struct mddev *mddev)
{
struct r10conf *conf = mddev->private;
sector_t lo, hi;
md_cluster_ops->resync_info_get(mddev, &lo, &hi);
if (((mddev->reshape_position <= hi) && (mddev->reshape_position >= lo))
|| mddev->reshape_position == MaxSector)
conf->reshape_progress = mddev->reshape_position;
else
WARN_ON_ONCE(1);
}
static int handle_reshape_read_error(struct mddev *mddev,
struct r10bio *r10_bio)
{
/* Use sync reads to get the blocks from somewhere else */
int sectors = r10_bio->sectors;
struct r10conf *conf = mddev->private;
struct r10bio *r10b;
int slot = 0;
int idx = 0;
struct page **pages;
r10b = kmalloc(struct_size(r10b, devs, conf->copies), GFP_NOIO);
if (!r10b) {
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
return -ENOMEM;
}
/* reshape IOs share pages from .devs[0].bio */
pages = get_resync_pages(r10_bio->devs[0].bio)->pages;
r10b->sector = r10_bio->sector;
__raid10_find_phys(&conf->prev, r10b);
while (sectors) {
int s = sectors;
int success = 0;
int first_slot = slot;
if (s > (PAGE_SIZE >> 9))
s = PAGE_SIZE >> 9;
rcu_read_lock();
while (!success) {
int d = r10b->devs[slot].devnum;
struct md_rdev *rdev = rcu_dereference(conf->mirrors[d].rdev);
sector_t addr;
if (rdev == NULL ||
test_bit(Faulty, &rdev->flags) ||
!test_bit(In_sync, &rdev->flags))
goto failed;
addr = r10b->devs[slot].addr + idx * PAGE_SIZE;
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
success = sync_page_io(rdev,
addr,
s << 9,
pages[idx],
REQ_OP_READ, false);
rdev_dec_pending(rdev, mddev);
rcu_read_lock();
if (success)
break;
failed:
slot++;
if (slot >= conf->copies)
slot = 0;
if (slot == first_slot)
break;
}
rcu_read_unlock();
if (!success) {
/* couldn't read this block, must give up */
set_bit(MD_RECOVERY_INTR,
&mddev->recovery);
kfree(r10b);
return -EIO;
}
sectors -= s;
idx++;
}
kfree(r10b);
return 0;
}
static void end_reshape_write(struct bio *bio)
{
struct r10bio *r10_bio = get_resync_r10bio(bio);
struct mddev *mddev = r10_bio->mddev;
struct r10conf *conf = mddev->private;
int d;
int slot;
int repl;
struct md_rdev *rdev = NULL;
d = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
if (repl)
rdev = conf->mirrors[d].replacement;
if (!rdev) {
smp_mb();
rdev = conf->mirrors[d].rdev;
}
if (bio->bi_status) {
/* FIXME should record badblock */
md_error(mddev, rdev);
}
rdev_dec_pending(rdev, mddev);
end_reshape_request(r10_bio);
}
static void end_reshape_request(struct r10bio *r10_bio)
{
if (!atomic_dec_and_test(&r10_bio->remaining))
return;
md_done_sync(r10_bio->mddev, r10_bio->sectors, 1);
bio_put(r10_bio->master_bio);
put_buf(r10_bio);
}
static void raid10_finish_reshape(struct mddev *mddev)
{
struct r10conf *conf = mddev->private;
if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
return;
if (mddev->delta_disks > 0) {
if (mddev->recovery_cp > mddev->resync_max_sectors) {
mddev->recovery_cp = mddev->resync_max_sectors;
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
}
mddev->resync_max_sectors = mddev->array_sectors;
} else {
int d;
rcu_read_lock();
for (d = conf->geo.raid_disks ;
d < conf->geo.raid_disks - mddev->delta_disks;
d++) {
struct md_rdev *rdev = rcu_dereference(conf->mirrors[d].rdev);
if (rdev)
clear_bit(In_sync, &rdev->flags);
rdev = rcu_dereference(conf->mirrors[d].replacement);
if (rdev)
clear_bit(In_sync, &rdev->flags);
}
rcu_read_unlock();
}
mddev->layout = mddev->new_layout;
mddev->chunk_sectors = 1 << conf->geo.chunk_shift;
mddev->reshape_position = MaxSector;
mddev->delta_disks = 0;
mddev->reshape_backwards = 0;
}
static struct md_personality raid10_personality =
{
.name = "raid10",
.level = 10,
.owner = THIS_MODULE,
.make_request = raid10_make_request,
.run = raid10_run,
.free = raid10_free,
.status = raid10_status,
.error_handler = raid10_error,
.hot_add_disk = raid10_add_disk,
.hot_remove_disk= raid10_remove_disk,
.spare_active = raid10_spare_active,
.sync_request = raid10_sync_request,
.quiesce = raid10_quiesce,
.size = raid10_size,
.resize = raid10_resize,
.takeover = raid10_takeover,
.check_reshape = raid10_check_reshape,
.start_reshape = raid10_start_reshape,
.finish_reshape = raid10_finish_reshape,
.update_reshape_pos = raid10_update_reshape_pos,
};
static int __init raid_init(void)
{
return register_md_personality(&raid10_personality);
}
static void raid_exit(void)
{
unregister_md_personality(&raid10_personality);
}
module_init(raid_init);
module_exit(raid_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("RAID10 (striped mirror) personality for MD");
MODULE_ALIAS("md-personality-9"); /* RAID10 */
MODULE_ALIAS("md-raid10");
MODULE_ALIAS("md-level-10");
| linux-master | drivers/md/raid10.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2002 Sistina Software (UK) Limited.
* Copyright (C) 2006 Red Hat GmbH
*
* This file is released under the GPL.
*
* Kcopyd provides a simple interface for copying an area of one
* block-device to one or more other block-devices, with an asynchronous
* completion notification.
*/
#include <linux/types.h>
#include <linux/atomic.h>
#include <linux/blkdev.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/mempool.h>
#include <linux/module.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/workqueue.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/device-mapper.h>
#include <linux/dm-kcopyd.h>
#include "dm-core.h"
#define SPLIT_COUNT 8
#define MIN_JOBS 8
#define DEFAULT_SUB_JOB_SIZE_KB 512
#define MAX_SUB_JOB_SIZE_KB 1024
static unsigned int kcopyd_subjob_size_kb = DEFAULT_SUB_JOB_SIZE_KB;
module_param(kcopyd_subjob_size_kb, uint, 0644);
MODULE_PARM_DESC(kcopyd_subjob_size_kb, "Sub-job size for dm-kcopyd clients");
static unsigned int dm_get_kcopyd_subjob_size(void)
{
unsigned int sub_job_size_kb;
sub_job_size_kb = __dm_get_module_param(&kcopyd_subjob_size_kb,
DEFAULT_SUB_JOB_SIZE_KB,
MAX_SUB_JOB_SIZE_KB);
return sub_job_size_kb << 1;
}
/*
*----------------------------------------------------------------
* Each kcopyd client has its own little pool of preallocated
* pages for kcopyd io.
*---------------------------------------------------------------
*/
struct dm_kcopyd_client {
struct page_list *pages;
unsigned int nr_reserved_pages;
unsigned int nr_free_pages;
unsigned int sub_job_size;
struct dm_io_client *io_client;
wait_queue_head_t destroyq;
mempool_t job_pool;
struct workqueue_struct *kcopyd_wq;
struct work_struct kcopyd_work;
struct dm_kcopyd_throttle *throttle;
atomic_t nr_jobs;
/*
* We maintain four lists of jobs:
*
* i) jobs waiting for pages
* ii) jobs that have pages, and are waiting for the io to be issued.
* iii) jobs that don't need to do any IO and just run a callback
* iv) jobs that have completed.
*
* All four of these are protected by job_lock.
*/
spinlock_t job_lock;
struct list_head callback_jobs;
struct list_head complete_jobs;
struct list_head io_jobs;
struct list_head pages_jobs;
};
static struct page_list zero_page_list;
static DEFINE_SPINLOCK(throttle_spinlock);
/*
* IO/IDLE accounting slowly decays after (1 << ACCOUNT_INTERVAL_SHIFT) period.
* When total_period >= (1 << ACCOUNT_INTERVAL_SHIFT) the counters are divided
* by 2.
*/
#define ACCOUNT_INTERVAL_SHIFT SHIFT_HZ
/*
* Sleep this number of milliseconds.
*
* The value was decided experimentally.
* Smaller values seem to cause an increased copy rate above the limit.
* The reason for this is unknown but possibly due to jiffies rounding errors
* or read/write cache inside the disk.
*/
#define SLEEP_USEC 100000
/*
* Maximum number of sleep events. There is a theoretical livelock if more
* kcopyd clients do work simultaneously which this limit avoids.
*/
#define MAX_SLEEPS 10
static void io_job_start(struct dm_kcopyd_throttle *t)
{
unsigned int throttle, now, difference;
int slept = 0, skew;
if (unlikely(!t))
return;
try_again:
spin_lock_irq(&throttle_spinlock);
throttle = READ_ONCE(t->throttle);
if (likely(throttle >= 100))
goto skip_limit;
now = jiffies;
difference = now - t->last_jiffies;
t->last_jiffies = now;
if (t->num_io_jobs)
t->io_period += difference;
t->total_period += difference;
/*
* Maintain sane values if we got a temporary overflow.
*/
if (unlikely(t->io_period > t->total_period))
t->io_period = t->total_period;
if (unlikely(t->total_period >= (1 << ACCOUNT_INTERVAL_SHIFT))) {
int shift = fls(t->total_period >> ACCOUNT_INTERVAL_SHIFT);
t->total_period >>= shift;
t->io_period >>= shift;
}
skew = t->io_period - throttle * t->total_period / 100;
if (unlikely(skew > 0) && slept < MAX_SLEEPS) {
slept++;
spin_unlock_irq(&throttle_spinlock);
fsleep(SLEEP_USEC);
goto try_again;
}
skip_limit:
t->num_io_jobs++;
spin_unlock_irq(&throttle_spinlock);
}
static void io_job_finish(struct dm_kcopyd_throttle *t)
{
unsigned long flags;
if (unlikely(!t))
return;
spin_lock_irqsave(&throttle_spinlock, flags);
t->num_io_jobs--;
if (likely(READ_ONCE(t->throttle) >= 100))
goto skip_limit;
if (!t->num_io_jobs) {
unsigned int now, difference;
now = jiffies;
difference = now - t->last_jiffies;
t->last_jiffies = now;
t->io_period += difference;
t->total_period += difference;
/*
* Maintain sane values if we got a temporary overflow.
*/
if (unlikely(t->io_period > t->total_period))
t->io_period = t->total_period;
}
skip_limit:
spin_unlock_irqrestore(&throttle_spinlock, flags);
}
static void wake(struct dm_kcopyd_client *kc)
{
queue_work(kc->kcopyd_wq, &kc->kcopyd_work);
}
/*
* Obtain one page for the use of kcopyd.
*/
static struct page_list *alloc_pl(gfp_t gfp)
{
struct page_list *pl;
pl = kmalloc(sizeof(*pl), gfp);
if (!pl)
return NULL;
pl->page = alloc_page(gfp | __GFP_HIGHMEM);
if (!pl->page) {
kfree(pl);
return NULL;
}
return pl;
}
static void free_pl(struct page_list *pl)
{
__free_page(pl->page);
kfree(pl);
}
/*
* Add the provided pages to a client's free page list, releasing
* back to the system any beyond the reserved_pages limit.
*/
static void kcopyd_put_pages(struct dm_kcopyd_client *kc, struct page_list *pl)
{
struct page_list *next;
do {
next = pl->next;
if (kc->nr_free_pages >= kc->nr_reserved_pages)
free_pl(pl);
else {
pl->next = kc->pages;
kc->pages = pl;
kc->nr_free_pages++;
}
pl = next;
} while (pl);
}
static int kcopyd_get_pages(struct dm_kcopyd_client *kc,
unsigned int nr, struct page_list **pages)
{
struct page_list *pl;
*pages = NULL;
do {
pl = alloc_pl(__GFP_NOWARN | __GFP_NORETRY | __GFP_KSWAPD_RECLAIM);
if (unlikely(!pl)) {
/* Use reserved pages */
pl = kc->pages;
if (unlikely(!pl))
goto out_of_memory;
kc->pages = pl->next;
kc->nr_free_pages--;
}
pl->next = *pages;
*pages = pl;
} while (--nr);
return 0;
out_of_memory:
if (*pages)
kcopyd_put_pages(kc, *pages);
return -ENOMEM;
}
/*
* These three functions resize the page pool.
*/
static void drop_pages(struct page_list *pl)
{
struct page_list *next;
while (pl) {
next = pl->next;
free_pl(pl);
pl = next;
}
}
/*
* Allocate and reserve nr_pages for the use of a specific client.
*/
static int client_reserve_pages(struct dm_kcopyd_client *kc, unsigned int nr_pages)
{
unsigned int i;
struct page_list *pl = NULL, *next;
for (i = 0; i < nr_pages; i++) {
next = alloc_pl(GFP_KERNEL);
if (!next) {
if (pl)
drop_pages(pl);
return -ENOMEM;
}
next->next = pl;
pl = next;
}
kc->nr_reserved_pages += nr_pages;
kcopyd_put_pages(kc, pl);
return 0;
}
static void client_free_pages(struct dm_kcopyd_client *kc)
{
BUG_ON(kc->nr_free_pages != kc->nr_reserved_pages);
drop_pages(kc->pages);
kc->pages = NULL;
kc->nr_free_pages = kc->nr_reserved_pages = 0;
}
/*
*---------------------------------------------------------------
* kcopyd_jobs need to be allocated by the *clients* of kcopyd,
* for this reason we use a mempool to prevent the client from
* ever having to do io (which could cause a deadlock).
*---------------------------------------------------------------
*/
struct kcopyd_job {
struct dm_kcopyd_client *kc;
struct list_head list;
unsigned int flags;
/*
* Error state of the job.
*/
int read_err;
unsigned long write_err;
/*
* REQ_OP_READ, REQ_OP_WRITE or REQ_OP_WRITE_ZEROES.
*/
enum req_op op;
struct dm_io_region source;
/*
* The destinations for the transfer.
*/
unsigned int num_dests;
struct dm_io_region dests[DM_KCOPYD_MAX_REGIONS];
struct page_list *pages;
/*
* Set this to ensure you are notified when the job has
* completed. 'context' is for callback to use.
*/
dm_kcopyd_notify_fn fn;
void *context;
/*
* These fields are only used if the job has been split
* into more manageable parts.
*/
struct mutex lock;
atomic_t sub_jobs;
sector_t progress;
sector_t write_offset;
struct kcopyd_job *master_job;
};
static struct kmem_cache *_job_cache;
int __init dm_kcopyd_init(void)
{
_job_cache = kmem_cache_create("kcopyd_job",
sizeof(struct kcopyd_job) * (SPLIT_COUNT + 1),
__alignof__(struct kcopyd_job), 0, NULL);
if (!_job_cache)
return -ENOMEM;
zero_page_list.next = &zero_page_list;
zero_page_list.page = ZERO_PAGE(0);
return 0;
}
void dm_kcopyd_exit(void)
{
kmem_cache_destroy(_job_cache);
_job_cache = NULL;
}
/*
* Functions to push and pop a job onto the head of a given job
* list.
*/
static struct kcopyd_job *pop_io_job(struct list_head *jobs,
struct dm_kcopyd_client *kc)
{
struct kcopyd_job *job;
/*
* For I/O jobs, pop any read, any write without sequential write
* constraint and sequential writes that are at the right position.
*/
list_for_each_entry(job, jobs, list) {
if (job->op == REQ_OP_READ ||
!(job->flags & BIT(DM_KCOPYD_WRITE_SEQ))) {
list_del(&job->list);
return job;
}
if (job->write_offset == job->master_job->write_offset) {
job->master_job->write_offset += job->source.count;
list_del(&job->list);
return job;
}
}
return NULL;
}
static struct kcopyd_job *pop(struct list_head *jobs,
struct dm_kcopyd_client *kc)
{
struct kcopyd_job *job = NULL;
spin_lock_irq(&kc->job_lock);
if (!list_empty(jobs)) {
if (jobs == &kc->io_jobs)
job = pop_io_job(jobs, kc);
else {
job = list_entry(jobs->next, struct kcopyd_job, list);
list_del(&job->list);
}
}
spin_unlock_irq(&kc->job_lock);
return job;
}
static void push(struct list_head *jobs, struct kcopyd_job *job)
{
unsigned long flags;
struct dm_kcopyd_client *kc = job->kc;
spin_lock_irqsave(&kc->job_lock, flags);
list_add_tail(&job->list, jobs);
spin_unlock_irqrestore(&kc->job_lock, flags);
}
static void push_head(struct list_head *jobs, struct kcopyd_job *job)
{
struct dm_kcopyd_client *kc = job->kc;
spin_lock_irq(&kc->job_lock);
list_add(&job->list, jobs);
spin_unlock_irq(&kc->job_lock);
}
/*
* These three functions process 1 item from the corresponding
* job list.
*
* They return:
* < 0: error
* 0: success
* > 0: can't process yet.
*/
static int run_complete_job(struct kcopyd_job *job)
{
void *context = job->context;
int read_err = job->read_err;
unsigned long write_err = job->write_err;
dm_kcopyd_notify_fn fn = job->fn;
struct dm_kcopyd_client *kc = job->kc;
if (job->pages && job->pages != &zero_page_list)
kcopyd_put_pages(kc, job->pages);
/*
* If this is the master job, the sub jobs have already
* completed so we can free everything.
*/
if (job->master_job == job) {
mutex_destroy(&job->lock);
mempool_free(job, &kc->job_pool);
}
fn(read_err, write_err, context);
if (atomic_dec_and_test(&kc->nr_jobs))
wake_up(&kc->destroyq);
cond_resched();
return 0;
}
static void complete_io(unsigned long error, void *context)
{
struct kcopyd_job *job = context;
struct dm_kcopyd_client *kc = job->kc;
io_job_finish(kc->throttle);
if (error) {
if (op_is_write(job->op))
job->write_err |= error;
else
job->read_err = 1;
if (!(job->flags & BIT(DM_KCOPYD_IGNORE_ERROR))) {
push(&kc->complete_jobs, job);
wake(kc);
return;
}
}
if (op_is_write(job->op))
push(&kc->complete_jobs, job);
else {
job->op = REQ_OP_WRITE;
push(&kc->io_jobs, job);
}
wake(kc);
}
/*
* Request io on as many buffer heads as we can currently get for
* a particular job.
*/
static int run_io_job(struct kcopyd_job *job)
{
int r;
struct dm_io_request io_req = {
.bi_opf = job->op,
.mem.type = DM_IO_PAGE_LIST,
.mem.ptr.pl = job->pages,
.mem.offset = 0,
.notify.fn = complete_io,
.notify.context = job,
.client = job->kc->io_client,
};
/*
* If we need to write sequentially and some reads or writes failed,
* no point in continuing.
*/
if (job->flags & BIT(DM_KCOPYD_WRITE_SEQ) &&
job->master_job->write_err) {
job->write_err = job->master_job->write_err;
return -EIO;
}
io_job_start(job->kc->throttle);
if (job->op == REQ_OP_READ)
r = dm_io(&io_req, 1, &job->source, NULL);
else
r = dm_io(&io_req, job->num_dests, job->dests, NULL);
return r;
}
static int run_pages_job(struct kcopyd_job *job)
{
int r;
unsigned int nr_pages = dm_div_up(job->dests[0].count, PAGE_SIZE >> 9);
r = kcopyd_get_pages(job->kc, nr_pages, &job->pages);
if (!r) {
/* this job is ready for io */
push(&job->kc->io_jobs, job);
return 0;
}
if (r == -ENOMEM)
/* can't complete now */
return 1;
return r;
}
/*
* Run through a list for as long as possible. Returns the count
* of successful jobs.
*/
static int process_jobs(struct list_head *jobs, struct dm_kcopyd_client *kc,
int (*fn)(struct kcopyd_job *))
{
struct kcopyd_job *job;
int r, count = 0;
while ((job = pop(jobs, kc))) {
r = fn(job);
if (r < 0) {
/* error this rogue job */
if (op_is_write(job->op))
job->write_err = (unsigned long) -1L;
else
job->read_err = 1;
push(&kc->complete_jobs, job);
wake(kc);
break;
}
if (r > 0) {
/*
* We couldn't service this job ATM, so
* push this job back onto the list.
*/
push_head(jobs, job);
break;
}
count++;
}
return count;
}
/*
* kcopyd does this every time it's woken up.
*/
static void do_work(struct work_struct *work)
{
struct dm_kcopyd_client *kc = container_of(work,
struct dm_kcopyd_client, kcopyd_work);
struct blk_plug plug;
/*
* The order that these are called is *very* important.
* complete jobs can free some pages for pages jobs.
* Pages jobs when successful will jump onto the io jobs
* list. io jobs call wake when they complete and it all
* starts again.
*/
spin_lock_irq(&kc->job_lock);
list_splice_tail_init(&kc->callback_jobs, &kc->complete_jobs);
spin_unlock_irq(&kc->job_lock);
blk_start_plug(&plug);
process_jobs(&kc->complete_jobs, kc, run_complete_job);
process_jobs(&kc->pages_jobs, kc, run_pages_job);
process_jobs(&kc->io_jobs, kc, run_io_job);
blk_finish_plug(&plug);
}
/*
* If we are copying a small region we just dispatch a single job
* to do the copy, otherwise the io has to be split up into many
* jobs.
*/
static void dispatch_job(struct kcopyd_job *job)
{
struct dm_kcopyd_client *kc = job->kc;
atomic_inc(&kc->nr_jobs);
if (unlikely(!job->source.count))
push(&kc->callback_jobs, job);
else if (job->pages == &zero_page_list)
push(&kc->io_jobs, job);
else
push(&kc->pages_jobs, job);
wake(kc);
}
static void segment_complete(int read_err, unsigned long write_err,
void *context)
{
/* FIXME: tidy this function */
sector_t progress = 0;
sector_t count = 0;
struct kcopyd_job *sub_job = context;
struct kcopyd_job *job = sub_job->master_job;
struct dm_kcopyd_client *kc = job->kc;
mutex_lock(&job->lock);
/* update the error */
if (read_err)
job->read_err = 1;
if (write_err)
job->write_err |= write_err;
/*
* Only dispatch more work if there hasn't been an error.
*/
if ((!job->read_err && !job->write_err) ||
job->flags & BIT(DM_KCOPYD_IGNORE_ERROR)) {
/* get the next chunk of work */
progress = job->progress;
count = job->source.count - progress;
if (count) {
if (count > kc->sub_job_size)
count = kc->sub_job_size;
job->progress += count;
}
}
mutex_unlock(&job->lock);
if (count) {
int i;
*sub_job = *job;
sub_job->write_offset = progress;
sub_job->source.sector += progress;
sub_job->source.count = count;
for (i = 0; i < job->num_dests; i++) {
sub_job->dests[i].sector += progress;
sub_job->dests[i].count = count;
}
sub_job->fn = segment_complete;
sub_job->context = sub_job;
dispatch_job(sub_job);
} else if (atomic_dec_and_test(&job->sub_jobs)) {
/*
* Queue the completion callback to the kcopyd thread.
*
* Some callers assume that all the completions are called
* from a single thread and don't race with each other.
*
* We must not call the callback directly here because this
* code may not be executing in the thread.
*/
push(&kc->complete_jobs, job);
wake(kc);
}
}
/*
* Create some sub jobs to share the work between them.
*/
static void split_job(struct kcopyd_job *master_job)
{
int i;
atomic_inc(&master_job->kc->nr_jobs);
atomic_set(&master_job->sub_jobs, SPLIT_COUNT);
for (i = 0; i < SPLIT_COUNT; i++) {
master_job[i + 1].master_job = master_job;
segment_complete(0, 0u, &master_job[i + 1]);
}
}
void dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from,
unsigned int num_dests, struct dm_io_region *dests,
unsigned int flags, dm_kcopyd_notify_fn fn, void *context)
{
struct kcopyd_job *job;
int i;
/*
* Allocate an array of jobs consisting of one master job
* followed by SPLIT_COUNT sub jobs.
*/
job = mempool_alloc(&kc->job_pool, GFP_NOIO);
mutex_init(&job->lock);
/*
* set up for the read.
*/
job->kc = kc;
job->flags = flags;
job->read_err = 0;
job->write_err = 0;
job->num_dests = num_dests;
memcpy(&job->dests, dests, sizeof(*dests) * num_dests);
/*
* If one of the destination is a host-managed zoned block device,
* we need to write sequentially. If one of the destination is a
* host-aware device, then leave it to the caller to choose what to do.
*/
if (!(job->flags & BIT(DM_KCOPYD_WRITE_SEQ))) {
for (i = 0; i < job->num_dests; i++) {
if (bdev_zoned_model(dests[i].bdev) == BLK_ZONED_HM) {
job->flags |= BIT(DM_KCOPYD_WRITE_SEQ);
break;
}
}
}
/*
* If we need to write sequentially, errors cannot be ignored.
*/
if (job->flags & BIT(DM_KCOPYD_WRITE_SEQ) &&
job->flags & BIT(DM_KCOPYD_IGNORE_ERROR))
job->flags &= ~BIT(DM_KCOPYD_IGNORE_ERROR);
if (from) {
job->source = *from;
job->pages = NULL;
job->op = REQ_OP_READ;
} else {
memset(&job->source, 0, sizeof(job->source));
job->source.count = job->dests[0].count;
job->pages = &zero_page_list;
/*
* Use WRITE ZEROES to optimize zeroing if all dests support it.
*/
job->op = REQ_OP_WRITE_ZEROES;
for (i = 0; i < job->num_dests; i++)
if (!bdev_write_zeroes_sectors(job->dests[i].bdev)) {
job->op = REQ_OP_WRITE;
break;
}
}
job->fn = fn;
job->context = context;
job->master_job = job;
job->write_offset = 0;
if (job->source.count <= kc->sub_job_size)
dispatch_job(job);
else {
job->progress = 0;
split_job(job);
}
}
EXPORT_SYMBOL(dm_kcopyd_copy);
void dm_kcopyd_zero(struct dm_kcopyd_client *kc,
unsigned int num_dests, struct dm_io_region *dests,
unsigned int flags, dm_kcopyd_notify_fn fn, void *context)
{
dm_kcopyd_copy(kc, NULL, num_dests, dests, flags, fn, context);
}
EXPORT_SYMBOL(dm_kcopyd_zero);
void *dm_kcopyd_prepare_callback(struct dm_kcopyd_client *kc,
dm_kcopyd_notify_fn fn, void *context)
{
struct kcopyd_job *job;
job = mempool_alloc(&kc->job_pool, GFP_NOIO);
memset(job, 0, sizeof(struct kcopyd_job));
job->kc = kc;
job->fn = fn;
job->context = context;
job->master_job = job;
atomic_inc(&kc->nr_jobs);
return job;
}
EXPORT_SYMBOL(dm_kcopyd_prepare_callback);
void dm_kcopyd_do_callback(void *j, int read_err, unsigned long write_err)
{
struct kcopyd_job *job = j;
struct dm_kcopyd_client *kc = job->kc;
job->read_err = read_err;
job->write_err = write_err;
push(&kc->callback_jobs, job);
wake(kc);
}
EXPORT_SYMBOL(dm_kcopyd_do_callback);
/*
* Cancels a kcopyd job, eg. someone might be deactivating a
* mirror.
*/
#if 0
int kcopyd_cancel(struct kcopyd_job *job, int block)
{
/* FIXME: finish */
return -1;
}
#endif /* 0 */
/*
*---------------------------------------------------------------
* Client setup
*---------------------------------------------------------------
*/
struct dm_kcopyd_client *dm_kcopyd_client_create(struct dm_kcopyd_throttle *throttle)
{
int r;
unsigned int reserve_pages;
struct dm_kcopyd_client *kc;
kc = kzalloc(sizeof(*kc), GFP_KERNEL);
if (!kc)
return ERR_PTR(-ENOMEM);
spin_lock_init(&kc->job_lock);
INIT_LIST_HEAD(&kc->callback_jobs);
INIT_LIST_HEAD(&kc->complete_jobs);
INIT_LIST_HEAD(&kc->io_jobs);
INIT_LIST_HEAD(&kc->pages_jobs);
kc->throttle = throttle;
r = mempool_init_slab_pool(&kc->job_pool, MIN_JOBS, _job_cache);
if (r)
goto bad_slab;
INIT_WORK(&kc->kcopyd_work, do_work);
kc->kcopyd_wq = alloc_workqueue("kcopyd", WQ_MEM_RECLAIM, 0);
if (!kc->kcopyd_wq) {
r = -ENOMEM;
goto bad_workqueue;
}
kc->sub_job_size = dm_get_kcopyd_subjob_size();
reserve_pages = DIV_ROUND_UP(kc->sub_job_size << SECTOR_SHIFT, PAGE_SIZE);
kc->pages = NULL;
kc->nr_reserved_pages = kc->nr_free_pages = 0;
r = client_reserve_pages(kc, reserve_pages);
if (r)
goto bad_client_pages;
kc->io_client = dm_io_client_create();
if (IS_ERR(kc->io_client)) {
r = PTR_ERR(kc->io_client);
goto bad_io_client;
}
init_waitqueue_head(&kc->destroyq);
atomic_set(&kc->nr_jobs, 0);
return kc;
bad_io_client:
client_free_pages(kc);
bad_client_pages:
destroy_workqueue(kc->kcopyd_wq);
bad_workqueue:
mempool_exit(&kc->job_pool);
bad_slab:
kfree(kc);
return ERR_PTR(r);
}
EXPORT_SYMBOL(dm_kcopyd_client_create);
void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc)
{
/* Wait for completion of all jobs submitted by this client. */
wait_event(kc->destroyq, !atomic_read(&kc->nr_jobs));
BUG_ON(!list_empty(&kc->callback_jobs));
BUG_ON(!list_empty(&kc->complete_jobs));
BUG_ON(!list_empty(&kc->io_jobs));
BUG_ON(!list_empty(&kc->pages_jobs));
destroy_workqueue(kc->kcopyd_wq);
dm_io_client_destroy(kc->io_client);
client_free_pages(kc);
mempool_exit(&kc->job_pool);
kfree(kc);
}
EXPORT_SYMBOL(dm_kcopyd_client_destroy);
void dm_kcopyd_client_flush(struct dm_kcopyd_client *kc)
{
flush_workqueue(kc->kcopyd_wq);
}
EXPORT_SYMBOL(dm_kcopyd_client_flush);
| linux-master | drivers/md/dm-kcopyd.c |
// SPDX-License-Identifier: GPL-2.0-or-later
/*
linear.c : Multiple Devices driver for Linux
Copyright (C) 1994-96 Marc ZYNGIER
<[email protected]> or
<[email protected]>
Linear mode management functions.
*/
#include <linux/blkdev.h>
#include <linux/raid/md_u.h>
#include <linux/seq_file.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <trace/events/block.h>
#include "md.h"
#include "md-linear.h"
/*
* find which device holds a particular offset
*/
static inline struct dev_info *which_dev(struct mddev *mddev, sector_t sector)
{
int lo, mid, hi;
struct linear_conf *conf;
lo = 0;
hi = mddev->raid_disks - 1;
conf = mddev->private;
/*
* Binary Search
*/
while (hi > lo) {
mid = (hi + lo) / 2;
if (sector < conf->disks[mid].end_sector)
hi = mid;
else
lo = mid + 1;
}
return conf->disks + lo;
}
static sector_t linear_size(struct mddev *mddev, sector_t sectors, int raid_disks)
{
struct linear_conf *conf;
sector_t array_sectors;
conf = mddev->private;
WARN_ONCE(sectors || raid_disks,
"%s does not support generic reshape\n", __func__);
array_sectors = conf->array_sectors;
return array_sectors;
}
static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks)
{
struct linear_conf *conf;
struct md_rdev *rdev;
int i, cnt;
conf = kzalloc(struct_size(conf, disks, raid_disks), GFP_KERNEL);
if (!conf)
return NULL;
cnt = 0;
conf->array_sectors = 0;
rdev_for_each(rdev, mddev) {
int j = rdev->raid_disk;
struct dev_info *disk = conf->disks + j;
sector_t sectors;
if (j < 0 || j >= raid_disks || disk->rdev) {
pr_warn("md/linear:%s: disk numbering problem. Aborting!\n",
mdname(mddev));
goto out;
}
disk->rdev = rdev;
if (mddev->chunk_sectors) {
sectors = rdev->sectors;
sector_div(sectors, mddev->chunk_sectors);
rdev->sectors = sectors * mddev->chunk_sectors;
}
disk_stack_limits(mddev->gendisk, rdev->bdev,
rdev->data_offset << 9);
conf->array_sectors += rdev->sectors;
cnt++;
}
if (cnt != raid_disks) {
pr_warn("md/linear:%s: not enough drives present. Aborting!\n",
mdname(mddev));
goto out;
}
/*
* Here we calculate the device offsets.
*/
conf->disks[0].end_sector = conf->disks[0].rdev->sectors;
for (i = 1; i < raid_disks; i++)
conf->disks[i].end_sector =
conf->disks[i-1].end_sector +
conf->disks[i].rdev->sectors;
/*
* conf->raid_disks is copy of mddev->raid_disks. The reason to
* keep a copy of mddev->raid_disks in struct linear_conf is,
* mddev->raid_disks may not be consistent with pointers number of
* conf->disks[] when it is updated in linear_add() and used to
* iterate old conf->disks[] earray in linear_congested().
* Here conf->raid_disks is always consitent with number of
* pointers in conf->disks[] array, and mddev->private is updated
* with rcu_assign_pointer() in linear_addr(), such race can be
* avoided.
*/
conf->raid_disks = raid_disks;
return conf;
out:
kfree(conf);
return NULL;
}
static int linear_run (struct mddev *mddev)
{
struct linear_conf *conf;
int ret;
if (md_check_no_bitmap(mddev))
return -EINVAL;
conf = linear_conf(mddev, mddev->raid_disks);
if (!conf)
return 1;
mddev->private = conf;
md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
ret = md_integrity_register(mddev);
if (ret) {
kfree(conf);
mddev->private = NULL;
}
return ret;
}
static int linear_add(struct mddev *mddev, struct md_rdev *rdev)
{
/* Adding a drive to a linear array allows the array to grow.
* It is permitted if the new drive has a matching superblock
* already on it, with raid_disk equal to raid_disks.
* It is achieved by creating a new linear_private_data structure
* and swapping it in in-place of the current one.
* The current one is never freed until the array is stopped.
* This avoids races.
*/
struct linear_conf *newconf, *oldconf;
if (rdev->saved_raid_disk != mddev->raid_disks)
return -EINVAL;
rdev->raid_disk = rdev->saved_raid_disk;
rdev->saved_raid_disk = -1;
newconf = linear_conf(mddev,mddev->raid_disks+1);
if (!newconf)
return -ENOMEM;
/* newconf->raid_disks already keeps a copy of * the increased
* value of mddev->raid_disks, WARN_ONCE() is just used to make
* sure of this. It is possible that oldconf is still referenced
* in linear_congested(), therefore kfree_rcu() is used to free
* oldconf until no one uses it anymore.
*/
mddev_suspend(mddev);
oldconf = rcu_dereference_protected(mddev->private,
lockdep_is_held(&mddev->reconfig_mutex));
mddev->raid_disks++;
WARN_ONCE(mddev->raid_disks != newconf->raid_disks,
"copied raid_disks doesn't match mddev->raid_disks");
rcu_assign_pointer(mddev->private, newconf);
md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
set_capacity_and_notify(mddev->gendisk, mddev->array_sectors);
mddev_resume(mddev);
kfree_rcu(oldconf, rcu);
return 0;
}
static void linear_free(struct mddev *mddev, void *priv)
{
struct linear_conf *conf = priv;
kfree(conf);
}
static bool linear_make_request(struct mddev *mddev, struct bio *bio)
{
struct dev_info *tmp_dev;
sector_t start_sector, end_sector, data_offset;
sector_t bio_sector = bio->bi_iter.bi_sector;
if (unlikely(bio->bi_opf & REQ_PREFLUSH)
&& md_flush_request(mddev, bio))
return true;
tmp_dev = which_dev(mddev, bio_sector);
start_sector = tmp_dev->end_sector - tmp_dev->rdev->sectors;
end_sector = tmp_dev->end_sector;
data_offset = tmp_dev->rdev->data_offset;
if (unlikely(bio_sector >= end_sector ||
bio_sector < start_sector))
goto out_of_bounds;
if (unlikely(is_rdev_broken(tmp_dev->rdev))) {
md_error(mddev, tmp_dev->rdev);
bio_io_error(bio);
return true;
}
if (unlikely(bio_end_sector(bio) > end_sector)) {
/* This bio crosses a device boundary, so we have to split it */
struct bio *split = bio_split(bio, end_sector - bio_sector,
GFP_NOIO, &mddev->bio_set);
bio_chain(split, bio);
submit_bio_noacct(bio);
bio = split;
}
md_account_bio(mddev, &bio);
bio_set_dev(bio, tmp_dev->rdev->bdev);
bio->bi_iter.bi_sector = bio->bi_iter.bi_sector -
start_sector + data_offset;
if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
!bdev_max_discard_sectors(bio->bi_bdev))) {
/* Just ignore it */
bio_endio(bio);
} else {
if (mddev->gendisk)
trace_block_bio_remap(bio, disk_devt(mddev->gendisk),
bio_sector);
mddev_check_write_zeroes(mddev, bio);
submit_bio_noacct(bio);
}
return true;
out_of_bounds:
pr_err("md/linear:%s: make_request: Sector %llu out of bounds on dev %pg: %llu sectors, offset %llu\n",
mdname(mddev),
(unsigned long long)bio->bi_iter.bi_sector,
tmp_dev->rdev->bdev,
(unsigned long long)tmp_dev->rdev->sectors,
(unsigned long long)start_sector);
bio_io_error(bio);
return true;
}
static void linear_status (struct seq_file *seq, struct mddev *mddev)
{
seq_printf(seq, " %dk rounding", mddev->chunk_sectors / 2);
}
static void linear_error(struct mddev *mddev, struct md_rdev *rdev)
{
if (!test_and_set_bit(MD_BROKEN, &mddev->flags)) {
char *md_name = mdname(mddev);
pr_crit("md/linear%s: Disk failure on %pg detected, failing array.\n",
md_name, rdev->bdev);
}
}
static void linear_quiesce(struct mddev *mddev, int state)
{
}
static struct md_personality linear_personality =
{
.name = "linear",
.level = LEVEL_LINEAR,
.owner = THIS_MODULE,
.make_request = linear_make_request,
.run = linear_run,
.free = linear_free,
.status = linear_status,
.hot_add_disk = linear_add,
.size = linear_size,
.quiesce = linear_quiesce,
.error_handler = linear_error,
};
static int __init linear_init (void)
{
return register_md_personality (&linear_personality);
}
static void linear_exit (void)
{
unregister_md_personality (&linear_personality);
}
module_init(linear_init);
module_exit(linear_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Linear device concatenation personality for MD (deprecated)");
MODULE_ALIAS("md-personality-1"); /* LINEAR - deprecated*/
MODULE_ALIAS("md-linear");
MODULE_ALIAS("md-level--1");
| linux-master | drivers/md/md-linear.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2017 Red Hat. All rights reserved.
*
* This file is released under the GPL.
*/
#include "dm-cache-background-tracker.h"
/*----------------------------------------------------------------*/
#define DM_MSG_PREFIX "dm-background-tracker"
struct bt_work {
struct list_head list;
struct rb_node node;
struct policy_work work;
};
struct background_tracker {
unsigned int max_work;
atomic_t pending_promotes;
atomic_t pending_writebacks;
atomic_t pending_demotes;
struct list_head issued;
struct list_head queued;
struct rb_root pending;
struct kmem_cache *work_cache;
};
struct background_tracker *btracker_create(unsigned int max_work)
{
struct background_tracker *b = kmalloc(sizeof(*b), GFP_KERNEL);
if (!b) {
DMERR("couldn't create background_tracker");
return NULL;
}
b->max_work = max_work;
atomic_set(&b->pending_promotes, 0);
atomic_set(&b->pending_writebacks, 0);
atomic_set(&b->pending_demotes, 0);
INIT_LIST_HEAD(&b->issued);
INIT_LIST_HEAD(&b->queued);
b->pending = RB_ROOT;
b->work_cache = KMEM_CACHE(bt_work, 0);
if (!b->work_cache) {
DMERR("couldn't create mempool for background work items");
kfree(b);
b = NULL;
}
return b;
}
EXPORT_SYMBOL_GPL(btracker_create);
void btracker_destroy(struct background_tracker *b)
{
struct bt_work *w, *tmp;
BUG_ON(!list_empty(&b->issued));
list_for_each_entry_safe (w, tmp, &b->queued, list) {
list_del(&w->list);
kmem_cache_free(b->work_cache, w);
}
kmem_cache_destroy(b->work_cache);
kfree(b);
}
EXPORT_SYMBOL_GPL(btracker_destroy);
static int cmp_oblock(dm_oblock_t lhs, dm_oblock_t rhs)
{
if (from_oblock(lhs) < from_oblock(rhs))
return -1;
if (from_oblock(rhs) < from_oblock(lhs))
return 1;
return 0;
}
static bool __insert_pending(struct background_tracker *b,
struct bt_work *nw)
{
int cmp;
struct bt_work *w;
struct rb_node **new = &b->pending.rb_node, *parent = NULL;
while (*new) {
w = container_of(*new, struct bt_work, node);
parent = *new;
cmp = cmp_oblock(w->work.oblock, nw->work.oblock);
if (cmp < 0)
new = &((*new)->rb_left);
else if (cmp > 0)
new = &((*new)->rb_right);
else
/* already present */
return false;
}
rb_link_node(&nw->node, parent, new);
rb_insert_color(&nw->node, &b->pending);
return true;
}
static struct bt_work *__find_pending(struct background_tracker *b,
dm_oblock_t oblock)
{
int cmp;
struct bt_work *w;
struct rb_node **new = &b->pending.rb_node;
while (*new) {
w = container_of(*new, struct bt_work, node);
cmp = cmp_oblock(w->work.oblock, oblock);
if (cmp < 0)
new = &((*new)->rb_left);
else if (cmp > 0)
new = &((*new)->rb_right);
else
break;
}
return *new ? w : NULL;
}
static void update_stats(struct background_tracker *b, struct policy_work *w, int delta)
{
switch (w->op) {
case POLICY_PROMOTE:
atomic_add(delta, &b->pending_promotes);
break;
case POLICY_DEMOTE:
atomic_add(delta, &b->pending_demotes);
break;
case POLICY_WRITEBACK:
atomic_add(delta, &b->pending_writebacks);
break;
}
}
unsigned int btracker_nr_writebacks_queued(struct background_tracker *b)
{
return atomic_read(&b->pending_writebacks);
}
EXPORT_SYMBOL_GPL(btracker_nr_writebacks_queued);
unsigned int btracker_nr_demotions_queued(struct background_tracker *b)
{
return atomic_read(&b->pending_demotes);
}
EXPORT_SYMBOL_GPL(btracker_nr_demotions_queued);
static bool max_work_reached(struct background_tracker *b)
{
return atomic_read(&b->pending_promotes) +
atomic_read(&b->pending_writebacks) +
atomic_read(&b->pending_demotes) >= b->max_work;
}
static struct bt_work *alloc_work(struct background_tracker *b)
{
if (max_work_reached(b))
return NULL;
return kmem_cache_alloc(b->work_cache, GFP_NOWAIT);
}
int btracker_queue(struct background_tracker *b,
struct policy_work *work,
struct policy_work **pwork)
{
struct bt_work *w;
if (pwork)
*pwork = NULL;
w = alloc_work(b);
if (!w)
return -ENOMEM;
memcpy(&w->work, work, sizeof(*work));
if (!__insert_pending(b, w)) {
/*
* There was a race, we'll just ignore this second
* bit of work for the same oblock.
*/
kmem_cache_free(b->work_cache, w);
return -EINVAL;
}
if (pwork) {
*pwork = &w->work;
list_add(&w->list, &b->issued);
} else
list_add(&w->list, &b->queued);
update_stats(b, &w->work, 1);
return 0;
}
EXPORT_SYMBOL_GPL(btracker_queue);
/*
* Returns -ENODATA if there's no work.
*/
int btracker_issue(struct background_tracker *b, struct policy_work **work)
{
struct bt_work *w;
if (list_empty(&b->queued))
return -ENODATA;
w = list_first_entry(&b->queued, struct bt_work, list);
list_move(&w->list, &b->issued);
*work = &w->work;
return 0;
}
EXPORT_SYMBOL_GPL(btracker_issue);
void btracker_complete(struct background_tracker *b,
struct policy_work *op)
{
struct bt_work *w = container_of(op, struct bt_work, work);
update_stats(b, &w->work, -1);
rb_erase(&w->node, &b->pending);
list_del(&w->list);
kmem_cache_free(b->work_cache, w);
}
EXPORT_SYMBOL_GPL(btracker_complete);
bool btracker_promotion_already_present(struct background_tracker *b,
dm_oblock_t oblock)
{
return __find_pending(b, oblock) != NULL;
}
EXPORT_SYMBOL_GPL(btracker_promotion_already_present);
/*----------------------------------------------------------------*/
| linux-master | drivers/md/dm-cache-background-tracker.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2003 Jana Saout <[email protected]>
* Copyright (C) 2004 Clemens Fruhwirth <[email protected]>
* Copyright (C) 2006-2020 Red Hat, Inc. All rights reserved.
* Copyright (C) 2013-2020 Milan Broz <[email protected]>
*
* This file is released under the GPL.
*/
#include <linux/completion.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/key.h>
#include <linux/bio.h>
#include <linux/blkdev.h>
#include <linux/blk-integrity.h>
#include <linux/mempool.h>
#include <linux/slab.h>
#include <linux/crypto.h>
#include <linux/workqueue.h>
#include <linux/kthread.h>
#include <linux/backing-dev.h>
#include <linux/atomic.h>
#include <linux/scatterlist.h>
#include <linux/rbtree.h>
#include <linux/ctype.h>
#include <asm/page.h>
#include <asm/unaligned.h>
#include <crypto/hash.h>
#include <crypto/md5.h>
#include <crypto/skcipher.h>
#include <crypto/aead.h>
#include <crypto/authenc.h>
#include <crypto/utils.h>
#include <linux/rtnetlink.h> /* for struct rtattr and RTA macros only */
#include <linux/key-type.h>
#include <keys/user-type.h>
#include <keys/encrypted-type.h>
#include <keys/trusted-type.h>
#include <linux/device-mapper.h>
#include "dm-audit.h"
#define DM_MSG_PREFIX "crypt"
/*
* context holding the current state of a multi-part conversion
*/
struct convert_context {
struct completion restart;
struct bio *bio_in;
struct bio *bio_out;
struct bvec_iter iter_in;
struct bvec_iter iter_out;
u64 cc_sector;
atomic_t cc_pending;
union {
struct skcipher_request *req;
struct aead_request *req_aead;
} r;
};
/*
* per bio private data
*/
struct dm_crypt_io {
struct crypt_config *cc;
struct bio *base_bio;
u8 *integrity_metadata;
bool integrity_metadata_from_pool:1;
bool in_tasklet:1;
struct work_struct work;
struct tasklet_struct tasklet;
struct convert_context ctx;
atomic_t io_pending;
blk_status_t error;
sector_t sector;
struct rb_node rb_node;
} CRYPTO_MINALIGN_ATTR;
struct dm_crypt_request {
struct convert_context *ctx;
struct scatterlist sg_in[4];
struct scatterlist sg_out[4];
u64 iv_sector;
};
struct crypt_config;
struct crypt_iv_operations {
int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
const char *opts);
void (*dtr)(struct crypt_config *cc);
int (*init)(struct crypt_config *cc);
int (*wipe)(struct crypt_config *cc);
int (*generator)(struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq);
int (*post)(struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq);
};
struct iv_benbi_private {
int shift;
};
#define LMK_SEED_SIZE 64 /* hash + 0 */
struct iv_lmk_private {
struct crypto_shash *hash_tfm;
u8 *seed;
};
#define TCW_WHITENING_SIZE 16
struct iv_tcw_private {
struct crypto_shash *crc32_tfm;
u8 *iv_seed;
u8 *whitening;
};
#define ELEPHANT_MAX_KEY_SIZE 32
struct iv_elephant_private {
struct crypto_skcipher *tfm;
};
/*
* Crypt: maps a linear range of a block device
* and encrypts / decrypts at the same time.
*/
enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD,
DM_CRYPT_NO_READ_WORKQUEUE, DM_CRYPT_NO_WRITE_WORKQUEUE,
DM_CRYPT_WRITE_INLINE };
enum cipher_flags {
CRYPT_MODE_INTEGRITY_AEAD, /* Use authenticated mode for cipher */
CRYPT_IV_LARGE_SECTORS, /* Calculate IV from sector_size, not 512B sectors */
CRYPT_ENCRYPT_PREPROCESS, /* Must preprocess data for encryption (elephant) */
};
/*
* The fields in here must be read only after initialization.
*/
struct crypt_config {
struct dm_dev *dev;
sector_t start;
struct percpu_counter n_allocated_pages;
struct workqueue_struct *io_queue;
struct workqueue_struct *crypt_queue;
spinlock_t write_thread_lock;
struct task_struct *write_thread;
struct rb_root write_tree;
char *cipher_string;
char *cipher_auth;
char *key_string;
const struct crypt_iv_operations *iv_gen_ops;
union {
struct iv_benbi_private benbi;
struct iv_lmk_private lmk;
struct iv_tcw_private tcw;
struct iv_elephant_private elephant;
} iv_gen_private;
u64 iv_offset;
unsigned int iv_size;
unsigned short sector_size;
unsigned char sector_shift;
union {
struct crypto_skcipher **tfms;
struct crypto_aead **tfms_aead;
} cipher_tfm;
unsigned int tfms_count;
unsigned long cipher_flags;
/*
* Layout of each crypto request:
*
* struct skcipher_request
* context
* padding
* struct dm_crypt_request
* padding
* IV
*
* The padding is added so that dm_crypt_request and the IV are
* correctly aligned.
*/
unsigned int dmreq_start;
unsigned int per_bio_data_size;
unsigned long flags;
unsigned int key_size;
unsigned int key_parts; /* independent parts in key buffer */
unsigned int key_extra_size; /* additional keys length */
unsigned int key_mac_size; /* MAC key size for authenc(...) */
unsigned int integrity_tag_size;
unsigned int integrity_iv_size;
unsigned int on_disk_tag_size;
/*
* pool for per bio private data, crypto requests,
* encryption requeusts/buffer pages and integrity tags
*/
unsigned int tag_pool_max_sectors;
mempool_t tag_pool;
mempool_t req_pool;
mempool_t page_pool;
struct bio_set bs;
struct mutex bio_alloc_lock;
u8 *authenc_key; /* space for keys in authenc() format (if used) */
u8 key[];
};
#define MIN_IOS 64
#define MAX_TAG_SIZE 480
#define POOL_ENTRY_SIZE 512
static DEFINE_SPINLOCK(dm_crypt_clients_lock);
static unsigned int dm_crypt_clients_n;
static volatile unsigned long dm_crypt_pages_per_client;
#define DM_CRYPT_MEMORY_PERCENT 2
#define DM_CRYPT_MIN_PAGES_PER_CLIENT (BIO_MAX_VECS * 16)
static void crypt_endio(struct bio *clone);
static void kcryptd_queue_crypt(struct dm_crypt_io *io);
static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
struct scatterlist *sg);
static bool crypt_integrity_aead(struct crypt_config *cc);
/*
* Use this to access cipher attributes that are independent of the key.
*/
static struct crypto_skcipher *any_tfm(struct crypt_config *cc)
{
return cc->cipher_tfm.tfms[0];
}
static struct crypto_aead *any_tfm_aead(struct crypt_config *cc)
{
return cc->cipher_tfm.tfms_aead[0];
}
/*
* Different IV generation algorithms:
*
* plain: the initial vector is the 32-bit little-endian version of the sector
* number, padded with zeros if necessary.
*
* plain64: the initial vector is the 64-bit little-endian version of the sector
* number, padded with zeros if necessary.
*
* plain64be: the initial vector is the 64-bit big-endian version of the sector
* number, padded with zeros if necessary.
*
* essiv: "encrypted sector|salt initial vector", the sector number is
* encrypted with the bulk cipher using a salt as key. The salt
* should be derived from the bulk cipher's key via hashing.
*
* benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
* (needed for LRW-32-AES and possible other narrow block modes)
*
* null: the initial vector is always zero. Provides compatibility with
* obsolete loop_fish2 devices. Do not use for new devices.
*
* lmk: Compatible implementation of the block chaining mode used
* by the Loop-AES block device encryption system
* designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
* It operates on full 512 byte sectors and uses CBC
* with an IV derived from the sector number, the data and
* optionally extra IV seed.
* This means that after decryption the first block
* of sector must be tweaked according to decrypted data.
* Loop-AES can use three encryption schemes:
* version 1: is plain aes-cbc mode
* version 2: uses 64 multikey scheme with lmk IV generator
* version 3: the same as version 2 with additional IV seed
* (it uses 65 keys, last key is used as IV seed)
*
* tcw: Compatible implementation of the block chaining mode used
* by the TrueCrypt device encryption system (prior to version 4.1).
* For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat
* It operates on full 512 byte sectors and uses CBC
* with an IV derived from initial key and the sector number.
* In addition, whitening value is applied on every sector, whitening
* is calculated from initial key, sector number and mixed using CRC32.
* Note that this encryption scheme is vulnerable to watermarking attacks
* and should be used for old compatible containers access only.
*
* eboiv: Encrypted byte-offset IV (used in Bitlocker in CBC mode)
* The IV is encrypted little-endian byte-offset (with the same key
* and cipher as the volume).
*
* elephant: The extended version of eboiv with additional Elephant diffuser
* used with Bitlocker CBC mode.
* This mode was used in older Windows systems
* https://download.microsoft.com/download/0/2/3/0238acaf-d3bf-4a6d-b3d6-0a0be4bbb36e/bitlockercipher200608.pdf
*/
static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq)
{
memset(iv, 0, cc->iv_size);
*(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
return 0;
}
static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq)
{
memset(iv, 0, cc->iv_size);
*(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
return 0;
}
static int crypt_iv_plain64be_gen(struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq)
{
memset(iv, 0, cc->iv_size);
/* iv_size is at least of size u64; usually it is 16 bytes */
*(__be64 *)&iv[cc->iv_size - sizeof(u64)] = cpu_to_be64(dmreq->iv_sector);
return 0;
}
static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq)
{
/*
* ESSIV encryption of the IV is now handled by the crypto API,
* so just pass the plain sector number here.
*/
memset(iv, 0, cc->iv_size);
*(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
return 0;
}
static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
const char *opts)
{
unsigned int bs;
int log;
if (crypt_integrity_aead(cc))
bs = crypto_aead_blocksize(any_tfm_aead(cc));
else
bs = crypto_skcipher_blocksize(any_tfm(cc));
log = ilog2(bs);
/*
* We need to calculate how far we must shift the sector count
* to get the cipher block count, we use this shift in _gen.
*/
if (1 << log != bs) {
ti->error = "cypher blocksize is not a power of 2";
return -EINVAL;
}
if (log > 9) {
ti->error = "cypher blocksize is > 512";
return -EINVAL;
}
cc->iv_gen_private.benbi.shift = 9 - log;
return 0;
}
static void crypt_iv_benbi_dtr(struct crypt_config *cc)
{
}
static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq)
{
__be64 val;
memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
return 0;
}
static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq)
{
memset(iv, 0, cc->iv_size);
return 0;
}
static void crypt_iv_lmk_dtr(struct crypt_config *cc)
{
struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
crypto_free_shash(lmk->hash_tfm);
lmk->hash_tfm = NULL;
kfree_sensitive(lmk->seed);
lmk->seed = NULL;
}
static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
const char *opts)
{
struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
if (cc->sector_size != (1 << SECTOR_SHIFT)) {
ti->error = "Unsupported sector size for LMK";
return -EINVAL;
}
lmk->hash_tfm = crypto_alloc_shash("md5", 0,
CRYPTO_ALG_ALLOCATES_MEMORY);
if (IS_ERR(lmk->hash_tfm)) {
ti->error = "Error initializing LMK hash";
return PTR_ERR(lmk->hash_tfm);
}
/* No seed in LMK version 2 */
if (cc->key_parts == cc->tfms_count) {
lmk->seed = NULL;
return 0;
}
lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
if (!lmk->seed) {
crypt_iv_lmk_dtr(cc);
ti->error = "Error kmallocing seed storage in LMK";
return -ENOMEM;
}
return 0;
}
static int crypt_iv_lmk_init(struct crypt_config *cc)
{
struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
int subkey_size = cc->key_size / cc->key_parts;
/* LMK seed is on the position of LMK_KEYS + 1 key */
if (lmk->seed)
memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
crypto_shash_digestsize(lmk->hash_tfm));
return 0;
}
static int crypt_iv_lmk_wipe(struct crypt_config *cc)
{
struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
if (lmk->seed)
memset(lmk->seed, 0, LMK_SEED_SIZE);
return 0;
}
static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq,
u8 *data)
{
struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
struct md5_state md5state;
__le32 buf[4];
int i, r;
desc->tfm = lmk->hash_tfm;
r = crypto_shash_init(desc);
if (r)
return r;
if (lmk->seed) {
r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE);
if (r)
return r;
}
/* Sector is always 512B, block size 16, add data of blocks 1-31 */
r = crypto_shash_update(desc, data + 16, 16 * 31);
if (r)
return r;
/* Sector is cropped to 56 bits here */
buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
buf[2] = cpu_to_le32(4024);
buf[3] = 0;
r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf));
if (r)
return r;
/* No MD5 padding here */
r = crypto_shash_export(desc, &md5state);
if (r)
return r;
for (i = 0; i < MD5_HASH_WORDS; i++)
__cpu_to_le32s(&md5state.hash[i]);
memcpy(iv, &md5state.hash, cc->iv_size);
return 0;
}
static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq)
{
struct scatterlist *sg;
u8 *src;
int r = 0;
if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
sg = crypt_get_sg_data(cc, dmreq->sg_in);
src = kmap_local_page(sg_page(sg));
r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset);
kunmap_local(src);
} else
memset(iv, 0, cc->iv_size);
return r;
}
static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq)
{
struct scatterlist *sg;
u8 *dst;
int r;
if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
return 0;
sg = crypt_get_sg_data(cc, dmreq->sg_out);
dst = kmap_local_page(sg_page(sg));
r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset);
/* Tweak the first block of plaintext sector */
if (!r)
crypto_xor(dst + sg->offset, iv, cc->iv_size);
kunmap_local(dst);
return r;
}
static void crypt_iv_tcw_dtr(struct crypt_config *cc)
{
struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
kfree_sensitive(tcw->iv_seed);
tcw->iv_seed = NULL;
kfree_sensitive(tcw->whitening);
tcw->whitening = NULL;
if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
crypto_free_shash(tcw->crc32_tfm);
tcw->crc32_tfm = NULL;
}
static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
const char *opts)
{
struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
if (cc->sector_size != (1 << SECTOR_SHIFT)) {
ti->error = "Unsupported sector size for TCW";
return -EINVAL;
}
if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
ti->error = "Wrong key size for TCW";
return -EINVAL;
}
tcw->crc32_tfm = crypto_alloc_shash("crc32", 0,
CRYPTO_ALG_ALLOCATES_MEMORY);
if (IS_ERR(tcw->crc32_tfm)) {
ti->error = "Error initializing CRC32 in TCW";
return PTR_ERR(tcw->crc32_tfm);
}
tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
if (!tcw->iv_seed || !tcw->whitening) {
crypt_iv_tcw_dtr(cc);
ti->error = "Error allocating seed storage in TCW";
return -ENOMEM;
}
return 0;
}
static int crypt_iv_tcw_init(struct crypt_config *cc)
{
struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
TCW_WHITENING_SIZE);
return 0;
}
static int crypt_iv_tcw_wipe(struct crypt_config *cc)
{
struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
memset(tcw->iv_seed, 0, cc->iv_size);
memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
return 0;
}
static int crypt_iv_tcw_whitening(struct crypt_config *cc,
struct dm_crypt_request *dmreq,
u8 *data)
{
struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
__le64 sector = cpu_to_le64(dmreq->iv_sector);
u8 buf[TCW_WHITENING_SIZE];
SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
int i, r;
/* xor whitening with sector number */
crypto_xor_cpy(buf, tcw->whitening, (u8 *)§or, 8);
crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)§or, 8);
/* calculate crc32 for every 32bit part and xor it */
desc->tfm = tcw->crc32_tfm;
for (i = 0; i < 4; i++) {
r = crypto_shash_init(desc);
if (r)
goto out;
r = crypto_shash_update(desc, &buf[i * 4], 4);
if (r)
goto out;
r = crypto_shash_final(desc, &buf[i * 4]);
if (r)
goto out;
}
crypto_xor(&buf[0], &buf[12], 4);
crypto_xor(&buf[4], &buf[8], 4);
/* apply whitening (8 bytes) to whole sector */
for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
crypto_xor(data + i * 8, buf, 8);
out:
memzero_explicit(buf, sizeof(buf));
return r;
}
static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq)
{
struct scatterlist *sg;
struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
__le64 sector = cpu_to_le64(dmreq->iv_sector);
u8 *src;
int r = 0;
/* Remove whitening from ciphertext */
if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
sg = crypt_get_sg_data(cc, dmreq->sg_in);
src = kmap_local_page(sg_page(sg));
r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset);
kunmap_local(src);
}
/* Calculate IV */
crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)§or, 8);
if (cc->iv_size > 8)
crypto_xor_cpy(&iv[8], tcw->iv_seed + 8, (u8 *)§or,
cc->iv_size - 8);
return r;
}
static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq)
{
struct scatterlist *sg;
u8 *dst;
int r;
if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
return 0;
/* Apply whitening on ciphertext */
sg = crypt_get_sg_data(cc, dmreq->sg_out);
dst = kmap_local_page(sg_page(sg));
r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset);
kunmap_local(dst);
return r;
}
static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq)
{
/* Used only for writes, there must be an additional space to store IV */
get_random_bytes(iv, cc->iv_size);
return 0;
}
static int crypt_iv_eboiv_ctr(struct crypt_config *cc, struct dm_target *ti,
const char *opts)
{
if (crypt_integrity_aead(cc)) {
ti->error = "AEAD transforms not supported for EBOIV";
return -EINVAL;
}
if (crypto_skcipher_blocksize(any_tfm(cc)) != cc->iv_size) {
ti->error = "Block size of EBOIV cipher does not match IV size of block cipher";
return -EINVAL;
}
return 0;
}
static int crypt_iv_eboiv_gen(struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq)
{
struct crypto_skcipher *tfm = any_tfm(cc);
struct skcipher_request *req;
struct scatterlist src, dst;
DECLARE_CRYPTO_WAIT(wait);
unsigned int reqsize;
int err;
u8 *buf;
reqsize = ALIGN(crypto_skcipher_reqsize(tfm), __alignof__(__le64));
req = kmalloc(reqsize + cc->iv_size, GFP_NOIO);
if (!req)
return -ENOMEM;
skcipher_request_set_tfm(req, tfm);
buf = (u8 *)req + reqsize;
memset(buf, 0, cc->iv_size);
*(__le64 *)buf = cpu_to_le64(dmreq->iv_sector * cc->sector_size);
sg_init_one(&src, page_address(ZERO_PAGE(0)), cc->iv_size);
sg_init_one(&dst, iv, cc->iv_size);
skcipher_request_set_crypt(req, &src, &dst, cc->iv_size, buf);
skcipher_request_set_callback(req, 0, crypto_req_done, &wait);
err = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
kfree_sensitive(req);
return err;
}
static void crypt_iv_elephant_dtr(struct crypt_config *cc)
{
struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
crypto_free_skcipher(elephant->tfm);
elephant->tfm = NULL;
}
static int crypt_iv_elephant_ctr(struct crypt_config *cc, struct dm_target *ti,
const char *opts)
{
struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
int r;
elephant->tfm = crypto_alloc_skcipher("ecb(aes)", 0,
CRYPTO_ALG_ALLOCATES_MEMORY);
if (IS_ERR(elephant->tfm)) {
r = PTR_ERR(elephant->tfm);
elephant->tfm = NULL;
return r;
}
r = crypt_iv_eboiv_ctr(cc, ti, NULL);
if (r)
crypt_iv_elephant_dtr(cc);
return r;
}
static void diffuser_disk_to_cpu(u32 *d, size_t n)
{
#ifndef __LITTLE_ENDIAN
int i;
for (i = 0; i < n; i++)
d[i] = le32_to_cpu((__le32)d[i]);
#endif
}
static void diffuser_cpu_to_disk(__le32 *d, size_t n)
{
#ifndef __LITTLE_ENDIAN
int i;
for (i = 0; i < n; i++)
d[i] = cpu_to_le32((u32)d[i]);
#endif
}
static void diffuser_a_decrypt(u32 *d, size_t n)
{
int i, i1, i2, i3;
for (i = 0; i < 5; i++) {
i1 = 0;
i2 = n - 2;
i3 = n - 5;
while (i1 < (n - 1)) {
d[i1] += d[i2] ^ (d[i3] << 9 | d[i3] >> 23);
i1++; i2++; i3++;
if (i3 >= n)
i3 -= n;
d[i1] += d[i2] ^ d[i3];
i1++; i2++; i3++;
if (i2 >= n)
i2 -= n;
d[i1] += d[i2] ^ (d[i3] << 13 | d[i3] >> 19);
i1++; i2++; i3++;
d[i1] += d[i2] ^ d[i3];
i1++; i2++; i3++;
}
}
}
static void diffuser_a_encrypt(u32 *d, size_t n)
{
int i, i1, i2, i3;
for (i = 0; i < 5; i++) {
i1 = n - 1;
i2 = n - 2 - 1;
i3 = n - 5 - 1;
while (i1 > 0) {
d[i1] -= d[i2] ^ d[i3];
i1--; i2--; i3--;
d[i1] -= d[i2] ^ (d[i3] << 13 | d[i3] >> 19);
i1--; i2--; i3--;
if (i2 < 0)
i2 += n;
d[i1] -= d[i2] ^ d[i3];
i1--; i2--; i3--;
if (i3 < 0)
i3 += n;
d[i1] -= d[i2] ^ (d[i3] << 9 | d[i3] >> 23);
i1--; i2--; i3--;
}
}
}
static void diffuser_b_decrypt(u32 *d, size_t n)
{
int i, i1, i2, i3;
for (i = 0; i < 3; i++) {
i1 = 0;
i2 = 2;
i3 = 5;
while (i1 < (n - 1)) {
d[i1] += d[i2] ^ d[i3];
i1++; i2++; i3++;
d[i1] += d[i2] ^ (d[i3] << 10 | d[i3] >> 22);
i1++; i2++; i3++;
if (i2 >= n)
i2 -= n;
d[i1] += d[i2] ^ d[i3];
i1++; i2++; i3++;
if (i3 >= n)
i3 -= n;
d[i1] += d[i2] ^ (d[i3] << 25 | d[i3] >> 7);
i1++; i2++; i3++;
}
}
}
static void diffuser_b_encrypt(u32 *d, size_t n)
{
int i, i1, i2, i3;
for (i = 0; i < 3; i++) {
i1 = n - 1;
i2 = 2 - 1;
i3 = 5 - 1;
while (i1 > 0) {
d[i1] -= d[i2] ^ (d[i3] << 25 | d[i3] >> 7);
i1--; i2--; i3--;
if (i3 < 0)
i3 += n;
d[i1] -= d[i2] ^ d[i3];
i1--; i2--; i3--;
if (i2 < 0)
i2 += n;
d[i1] -= d[i2] ^ (d[i3] << 10 | d[i3] >> 22);
i1--; i2--; i3--;
d[i1] -= d[i2] ^ d[i3];
i1--; i2--; i3--;
}
}
}
static int crypt_iv_elephant(struct crypt_config *cc, struct dm_crypt_request *dmreq)
{
struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
u8 *es, *ks, *data, *data2, *data_offset;
struct skcipher_request *req;
struct scatterlist *sg, *sg2, src, dst;
DECLARE_CRYPTO_WAIT(wait);
int i, r;
req = skcipher_request_alloc(elephant->tfm, GFP_NOIO);
es = kzalloc(16, GFP_NOIO); /* Key for AES */
ks = kzalloc(32, GFP_NOIO); /* Elephant sector key */
if (!req || !es || !ks) {
r = -ENOMEM;
goto out;
}
*(__le64 *)es = cpu_to_le64(dmreq->iv_sector * cc->sector_size);
/* E(Ks, e(s)) */
sg_init_one(&src, es, 16);
sg_init_one(&dst, ks, 16);
skcipher_request_set_crypt(req, &src, &dst, 16, NULL);
skcipher_request_set_callback(req, 0, crypto_req_done, &wait);
r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
if (r)
goto out;
/* E(Ks, e'(s)) */
es[15] = 0x80;
sg_init_one(&dst, &ks[16], 16);
r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
if (r)
goto out;
sg = crypt_get_sg_data(cc, dmreq->sg_out);
data = kmap_local_page(sg_page(sg));
data_offset = data + sg->offset;
/* Cannot modify original bio, copy to sg_out and apply Elephant to it */
if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
sg2 = crypt_get_sg_data(cc, dmreq->sg_in);
data2 = kmap_local_page(sg_page(sg2));
memcpy(data_offset, data2 + sg2->offset, cc->sector_size);
kunmap_local(data2);
}
if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
diffuser_disk_to_cpu((u32 *)data_offset, cc->sector_size / sizeof(u32));
diffuser_b_decrypt((u32 *)data_offset, cc->sector_size / sizeof(u32));
diffuser_a_decrypt((u32 *)data_offset, cc->sector_size / sizeof(u32));
diffuser_cpu_to_disk((__le32 *)data_offset, cc->sector_size / sizeof(u32));
}
for (i = 0; i < (cc->sector_size / 32); i++)
crypto_xor(data_offset + i * 32, ks, 32);
if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
diffuser_disk_to_cpu((u32 *)data_offset, cc->sector_size / sizeof(u32));
diffuser_a_encrypt((u32 *)data_offset, cc->sector_size / sizeof(u32));
diffuser_b_encrypt((u32 *)data_offset, cc->sector_size / sizeof(u32));
diffuser_cpu_to_disk((__le32 *)data_offset, cc->sector_size / sizeof(u32));
}
kunmap_local(data);
out:
kfree_sensitive(ks);
kfree_sensitive(es);
skcipher_request_free(req);
return r;
}
static int crypt_iv_elephant_gen(struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq)
{
int r;
if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
r = crypt_iv_elephant(cc, dmreq);
if (r)
return r;
}
return crypt_iv_eboiv_gen(cc, iv, dmreq);
}
static int crypt_iv_elephant_post(struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq)
{
if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
return crypt_iv_elephant(cc, dmreq);
return 0;
}
static int crypt_iv_elephant_init(struct crypt_config *cc)
{
struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
int key_offset = cc->key_size - cc->key_extra_size;
return crypto_skcipher_setkey(elephant->tfm, &cc->key[key_offset], cc->key_extra_size);
}
static int crypt_iv_elephant_wipe(struct crypt_config *cc)
{
struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
u8 key[ELEPHANT_MAX_KEY_SIZE];
memset(key, 0, cc->key_extra_size);
return crypto_skcipher_setkey(elephant->tfm, key, cc->key_extra_size);
}
static const struct crypt_iv_operations crypt_iv_plain_ops = {
.generator = crypt_iv_plain_gen
};
static const struct crypt_iv_operations crypt_iv_plain64_ops = {
.generator = crypt_iv_plain64_gen
};
static const struct crypt_iv_operations crypt_iv_plain64be_ops = {
.generator = crypt_iv_plain64be_gen
};
static const struct crypt_iv_operations crypt_iv_essiv_ops = {
.generator = crypt_iv_essiv_gen
};
static const struct crypt_iv_operations crypt_iv_benbi_ops = {
.ctr = crypt_iv_benbi_ctr,
.dtr = crypt_iv_benbi_dtr,
.generator = crypt_iv_benbi_gen
};
static const struct crypt_iv_operations crypt_iv_null_ops = {
.generator = crypt_iv_null_gen
};
static const struct crypt_iv_operations crypt_iv_lmk_ops = {
.ctr = crypt_iv_lmk_ctr,
.dtr = crypt_iv_lmk_dtr,
.init = crypt_iv_lmk_init,
.wipe = crypt_iv_lmk_wipe,
.generator = crypt_iv_lmk_gen,
.post = crypt_iv_lmk_post
};
static const struct crypt_iv_operations crypt_iv_tcw_ops = {
.ctr = crypt_iv_tcw_ctr,
.dtr = crypt_iv_tcw_dtr,
.init = crypt_iv_tcw_init,
.wipe = crypt_iv_tcw_wipe,
.generator = crypt_iv_tcw_gen,
.post = crypt_iv_tcw_post
};
static const struct crypt_iv_operations crypt_iv_random_ops = {
.generator = crypt_iv_random_gen
};
static const struct crypt_iv_operations crypt_iv_eboiv_ops = {
.ctr = crypt_iv_eboiv_ctr,
.generator = crypt_iv_eboiv_gen
};
static const struct crypt_iv_operations crypt_iv_elephant_ops = {
.ctr = crypt_iv_elephant_ctr,
.dtr = crypt_iv_elephant_dtr,
.init = crypt_iv_elephant_init,
.wipe = crypt_iv_elephant_wipe,
.generator = crypt_iv_elephant_gen,
.post = crypt_iv_elephant_post
};
/*
* Integrity extensions
*/
static bool crypt_integrity_aead(struct crypt_config *cc)
{
return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
}
static bool crypt_integrity_hmac(struct crypt_config *cc)
{
return crypt_integrity_aead(cc) && cc->key_mac_size;
}
/* Get sg containing data */
static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
struct scatterlist *sg)
{
if (unlikely(crypt_integrity_aead(cc)))
return &sg[2];
return sg;
}
static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio)
{
struct bio_integrity_payload *bip;
unsigned int tag_len;
int ret;
if (!bio_sectors(bio) || !io->cc->on_disk_tag_size)
return 0;
bip = bio_integrity_alloc(bio, GFP_NOIO, 1);
if (IS_ERR(bip))
return PTR_ERR(bip);
tag_len = io->cc->on_disk_tag_size * (bio_sectors(bio) >> io->cc->sector_shift);
bip->bip_iter.bi_sector = io->cc->start + io->sector;
ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata),
tag_len, offset_in_page(io->integrity_metadata));
if (unlikely(ret != tag_len))
return -ENOMEM;
return 0;
}
static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti)
{
#ifdef CONFIG_BLK_DEV_INTEGRITY
struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk);
struct mapped_device *md = dm_table_get_md(ti->table);
/* From now we require underlying device with our integrity profile */
if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) {
ti->error = "Integrity profile not supported.";
return -EINVAL;
}
if (bi->tag_size != cc->on_disk_tag_size ||
bi->tuple_size != cc->on_disk_tag_size) {
ti->error = "Integrity profile tag size mismatch.";
return -EINVAL;
}
if (1 << bi->interval_exp != cc->sector_size) {
ti->error = "Integrity profile sector size mismatch.";
return -EINVAL;
}
if (crypt_integrity_aead(cc)) {
cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size;
DMDEBUG("%s: Integrity AEAD, tag size %u, IV size %u.", dm_device_name(md),
cc->integrity_tag_size, cc->integrity_iv_size);
if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) {
ti->error = "Integrity AEAD auth tag size is not supported.";
return -EINVAL;
}
} else if (cc->integrity_iv_size)
DMDEBUG("%s: Additional per-sector space %u bytes for IV.", dm_device_name(md),
cc->integrity_iv_size);
if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) {
ti->error = "Not enough space for integrity tag in the profile.";
return -EINVAL;
}
return 0;
#else
ti->error = "Integrity profile not supported.";
return -EINVAL;
#endif
}
static void crypt_convert_init(struct crypt_config *cc,
struct convert_context *ctx,
struct bio *bio_out, struct bio *bio_in,
sector_t sector)
{
ctx->bio_in = bio_in;
ctx->bio_out = bio_out;
if (bio_in)
ctx->iter_in = bio_in->bi_iter;
if (bio_out)
ctx->iter_out = bio_out->bi_iter;
ctx->cc_sector = sector + cc->iv_offset;
init_completion(&ctx->restart);
}
static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
void *req)
{
return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
}
static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq)
{
return (void *)((char *)dmreq - cc->dmreq_start);
}
static u8 *iv_of_dmreq(struct crypt_config *cc,
struct dm_crypt_request *dmreq)
{
if (crypt_integrity_aead(cc))
return (u8 *)ALIGN((unsigned long)(dmreq + 1),
crypto_aead_alignmask(any_tfm_aead(cc)) + 1);
else
return (u8 *)ALIGN((unsigned long)(dmreq + 1),
crypto_skcipher_alignmask(any_tfm(cc)) + 1);
}
static u8 *org_iv_of_dmreq(struct crypt_config *cc,
struct dm_crypt_request *dmreq)
{
return iv_of_dmreq(cc, dmreq) + cc->iv_size;
}
static __le64 *org_sector_of_dmreq(struct crypt_config *cc,
struct dm_crypt_request *dmreq)
{
u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size;
return (__le64 *) ptr;
}
static unsigned int *org_tag_of_dmreq(struct crypt_config *cc,
struct dm_crypt_request *dmreq)
{
u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size +
cc->iv_size + sizeof(uint64_t);
return (unsigned int *)ptr;
}
static void *tag_from_dmreq(struct crypt_config *cc,
struct dm_crypt_request *dmreq)
{
struct convert_context *ctx = dmreq->ctx;
struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) *
cc->on_disk_tag_size];
}
static void *iv_tag_from_dmreq(struct crypt_config *cc,
struct dm_crypt_request *dmreq)
{
return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size;
}
static int crypt_convert_block_aead(struct crypt_config *cc,
struct convert_context *ctx,
struct aead_request *req,
unsigned int tag_offset)
{
struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
struct dm_crypt_request *dmreq;
u8 *iv, *org_iv, *tag_iv, *tag;
__le64 *sector;
int r = 0;
BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size);
/* Reject unexpected unaligned bio. */
if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
return -EIO;
dmreq = dmreq_of_req(cc, req);
dmreq->iv_sector = ctx->cc_sector;
if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
dmreq->iv_sector >>= cc->sector_shift;
dmreq->ctx = ctx;
*org_tag_of_dmreq(cc, dmreq) = tag_offset;
sector = org_sector_of_dmreq(cc, dmreq);
*sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
iv = iv_of_dmreq(cc, dmreq);
org_iv = org_iv_of_dmreq(cc, dmreq);
tag = tag_from_dmreq(cc, dmreq);
tag_iv = iv_tag_from_dmreq(cc, dmreq);
/* AEAD request:
* |----- AAD -------|------ DATA -------|-- AUTH TAG --|
* | (authenticated) | (auth+encryption) | |
* | sector_LE | IV | sector in/out | tag in/out |
*/
sg_init_table(dmreq->sg_in, 4);
sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t));
sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size);
sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size);
sg_init_table(dmreq->sg_out, 4);
sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t));
sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size);
sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size);
if (cc->iv_gen_ops) {
/* For READs use IV stored in integrity metadata */
if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
memcpy(org_iv, tag_iv, cc->iv_size);
} else {
r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
if (r < 0)
return r;
/* Store generated IV in integrity metadata */
if (cc->integrity_iv_size)
memcpy(tag_iv, org_iv, cc->iv_size);
}
/* Working copy of IV, to be modified in crypto API */
memcpy(iv, org_iv, cc->iv_size);
}
aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size);
if (bio_data_dir(ctx->bio_in) == WRITE) {
aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
cc->sector_size, iv);
r = crypto_aead_encrypt(req);
if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size)
memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0,
cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size));
} else {
aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
cc->sector_size + cc->integrity_tag_size, iv);
r = crypto_aead_decrypt(req);
}
if (r == -EBADMSG) {
sector_t s = le64_to_cpu(*sector);
DMERR_LIMIT("%pg: INTEGRITY AEAD ERROR, sector %llu",
ctx->bio_in->bi_bdev, s);
dm_audit_log_bio(DM_MSG_PREFIX, "integrity-aead",
ctx->bio_in, s, 0);
}
if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
return r;
}
static int crypt_convert_block_skcipher(struct crypt_config *cc,
struct convert_context *ctx,
struct skcipher_request *req,
unsigned int tag_offset)
{
struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
struct scatterlist *sg_in, *sg_out;
struct dm_crypt_request *dmreq;
u8 *iv, *org_iv, *tag_iv;
__le64 *sector;
int r = 0;
/* Reject unexpected unaligned bio. */
if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
return -EIO;
dmreq = dmreq_of_req(cc, req);
dmreq->iv_sector = ctx->cc_sector;
if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
dmreq->iv_sector >>= cc->sector_shift;
dmreq->ctx = ctx;
*org_tag_of_dmreq(cc, dmreq) = tag_offset;
iv = iv_of_dmreq(cc, dmreq);
org_iv = org_iv_of_dmreq(cc, dmreq);
tag_iv = iv_tag_from_dmreq(cc, dmreq);
sector = org_sector_of_dmreq(cc, dmreq);
*sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
/* For skcipher we use only the first sg item */
sg_in = &dmreq->sg_in[0];
sg_out = &dmreq->sg_out[0];
sg_init_table(sg_in, 1);
sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
sg_init_table(sg_out, 1);
sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
if (cc->iv_gen_ops) {
/* For READs use IV stored in integrity metadata */
if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
memcpy(org_iv, tag_iv, cc->integrity_iv_size);
} else {
r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
if (r < 0)
return r;
/* Data can be already preprocessed in generator */
if (test_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags))
sg_in = sg_out;
/* Store generated IV in integrity metadata */
if (cc->integrity_iv_size)
memcpy(tag_iv, org_iv, cc->integrity_iv_size);
}
/* Working copy of IV, to be modified in crypto API */
memcpy(iv, org_iv, cc->iv_size);
}
skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv);
if (bio_data_dir(ctx->bio_in) == WRITE)
r = crypto_skcipher_encrypt(req);
else
r = crypto_skcipher_decrypt(req);
if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
return r;
}
static void kcryptd_async_done(void *async_req, int error);
static int crypt_alloc_req_skcipher(struct crypt_config *cc,
struct convert_context *ctx)
{
unsigned int key_index = ctx->cc_sector & (cc->tfms_count - 1);
if (!ctx->r.req) {
ctx->r.req = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO);
if (!ctx->r.req)
return -ENOMEM;
}
skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]);
/*
* Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
* requests if driver request queue is full.
*/
skcipher_request_set_callback(ctx->r.req,
CRYPTO_TFM_REQ_MAY_BACKLOG,
kcryptd_async_done, dmreq_of_req(cc, ctx->r.req));
return 0;
}
static int crypt_alloc_req_aead(struct crypt_config *cc,
struct convert_context *ctx)
{
if (!ctx->r.req_aead) {
ctx->r.req_aead = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO);
if (!ctx->r.req_aead)
return -ENOMEM;
}
aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]);
/*
* Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
* requests if driver request queue is full.
*/
aead_request_set_callback(ctx->r.req_aead,
CRYPTO_TFM_REQ_MAY_BACKLOG,
kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead));
return 0;
}
static int crypt_alloc_req(struct crypt_config *cc,
struct convert_context *ctx)
{
if (crypt_integrity_aead(cc))
return crypt_alloc_req_aead(cc, ctx);
else
return crypt_alloc_req_skcipher(cc, ctx);
}
static void crypt_free_req_skcipher(struct crypt_config *cc,
struct skcipher_request *req, struct bio *base_bio)
{
struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
if ((struct skcipher_request *)(io + 1) != req)
mempool_free(req, &cc->req_pool);
}
static void crypt_free_req_aead(struct crypt_config *cc,
struct aead_request *req, struct bio *base_bio)
{
struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
if ((struct aead_request *)(io + 1) != req)
mempool_free(req, &cc->req_pool);
}
static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio)
{
if (crypt_integrity_aead(cc))
crypt_free_req_aead(cc, req, base_bio);
else
crypt_free_req_skcipher(cc, req, base_bio);
}
/*
* Encrypt / decrypt data from one bio to another one (can be the same one)
*/
static blk_status_t crypt_convert(struct crypt_config *cc,
struct convert_context *ctx, bool atomic, bool reset_pending)
{
unsigned int tag_offset = 0;
unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT;
int r;
/*
* if reset_pending is set we are dealing with the bio for the first time,
* else we're continuing to work on the previous bio, so don't mess with
* the cc_pending counter
*/
if (reset_pending)
atomic_set(&ctx->cc_pending, 1);
while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
r = crypt_alloc_req(cc, ctx);
if (r) {
complete(&ctx->restart);
return BLK_STS_DEV_RESOURCE;
}
atomic_inc(&ctx->cc_pending);
if (crypt_integrity_aead(cc))
r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset);
else
r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, tag_offset);
switch (r) {
/*
* The request was queued by a crypto driver
* but the driver request queue is full, let's wait.
*/
case -EBUSY:
if (in_interrupt()) {
if (try_wait_for_completion(&ctx->restart)) {
/*
* we don't have to block to wait for completion,
* so proceed
*/
} else {
/*
* we can't wait for completion without blocking
* exit and continue processing in a workqueue
*/
ctx->r.req = NULL;
ctx->cc_sector += sector_step;
tag_offset++;
return BLK_STS_DEV_RESOURCE;
}
} else {
wait_for_completion(&ctx->restart);
}
reinit_completion(&ctx->restart);
fallthrough;
/*
* The request is queued and processed asynchronously,
* completion function kcryptd_async_done() will be called.
*/
case -EINPROGRESS:
ctx->r.req = NULL;
ctx->cc_sector += sector_step;
tag_offset++;
continue;
/*
* The request was already processed (synchronously).
*/
case 0:
atomic_dec(&ctx->cc_pending);
ctx->cc_sector += sector_step;
tag_offset++;
if (!atomic)
cond_resched();
continue;
/*
* There was a data integrity error.
*/
case -EBADMSG:
atomic_dec(&ctx->cc_pending);
return BLK_STS_PROTECTION;
/*
* There was an error while processing the request.
*/
default:
atomic_dec(&ctx->cc_pending);
return BLK_STS_IOERR;
}
}
return 0;
}
static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone);
/*
* Generate a new unfragmented bio with the given size
* This should never violate the device limitations (but only because
* max_segment_size is being constrained to PAGE_SIZE).
*
* This function may be called concurrently. If we allocate from the mempool
* concurrently, there is a possibility of deadlock. For example, if we have
* mempool of 256 pages, two processes, each wanting 256, pages allocate from
* the mempool concurrently, it may deadlock in a situation where both processes
* have allocated 128 pages and the mempool is exhausted.
*
* In order to avoid this scenario we allocate the pages under a mutex.
*
* In order to not degrade performance with excessive locking, we try
* non-blocking allocations without a mutex first but on failure we fallback
* to blocking allocations with a mutex.
*
* In order to reduce allocation overhead, we try to allocate compound pages in
* the first pass. If they are not available, we fall back to the mempool.
*/
static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned int size)
{
struct crypt_config *cc = io->cc;
struct bio *clone;
unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
unsigned int remaining_size;
unsigned int order = MAX_ORDER - 1;
retry:
if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
mutex_lock(&cc->bio_alloc_lock);
clone = bio_alloc_bioset(cc->dev->bdev, nr_iovecs, io->base_bio->bi_opf,
GFP_NOIO, &cc->bs);
clone->bi_private = io;
clone->bi_end_io = crypt_endio;
remaining_size = size;
while (remaining_size) {
struct page *pages;
unsigned size_to_add;
unsigned remaining_order = __fls((remaining_size + PAGE_SIZE - 1) >> PAGE_SHIFT);
order = min(order, remaining_order);
while (order > 0) {
pages = alloc_pages(gfp_mask
| __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN | __GFP_COMP,
order);
if (likely(pages != NULL))
goto have_pages;
order--;
}
pages = mempool_alloc(&cc->page_pool, gfp_mask);
if (!pages) {
crypt_free_buffer_pages(cc, clone);
bio_put(clone);
gfp_mask |= __GFP_DIRECT_RECLAIM;
order = 0;
goto retry;
}
have_pages:
size_to_add = min((unsigned)PAGE_SIZE << order, remaining_size);
__bio_add_page(clone, pages, size_to_add, 0);
remaining_size -= size_to_add;
}
/* Allocate space for integrity tags */
if (dm_crypt_integrity_io_alloc(io, clone)) {
crypt_free_buffer_pages(cc, clone);
bio_put(clone);
clone = NULL;
}
if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
mutex_unlock(&cc->bio_alloc_lock);
return clone;
}
static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
{
struct folio_iter fi;
if (clone->bi_vcnt > 0) { /* bio_for_each_folio_all crashes with an empty bio */
bio_for_each_folio_all(fi, clone) {
if (folio_test_large(fi.folio))
folio_put(fi.folio);
else
mempool_free(&fi.folio->page, &cc->page_pool);
}
}
}
static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
struct bio *bio, sector_t sector)
{
io->cc = cc;
io->base_bio = bio;
io->sector = sector;
io->error = 0;
io->ctx.r.req = NULL;
io->integrity_metadata = NULL;
io->integrity_metadata_from_pool = false;
io->in_tasklet = false;
atomic_set(&io->io_pending, 0);
}
static void crypt_inc_pending(struct dm_crypt_io *io)
{
atomic_inc(&io->io_pending);
}
static void kcryptd_io_bio_endio(struct work_struct *work)
{
struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
bio_endio(io->base_bio);
}
/*
* One of the bios was finished. Check for completion of
* the whole request and correctly clean up the buffer.
*/
static void crypt_dec_pending(struct dm_crypt_io *io)
{
struct crypt_config *cc = io->cc;
struct bio *base_bio = io->base_bio;
blk_status_t error = io->error;
if (!atomic_dec_and_test(&io->io_pending))
return;
if (io->ctx.r.req)
crypt_free_req(cc, io->ctx.r.req, base_bio);
if (unlikely(io->integrity_metadata_from_pool))
mempool_free(io->integrity_metadata, &io->cc->tag_pool);
else
kfree(io->integrity_metadata);
base_bio->bi_status = error;
/*
* If we are running this function from our tasklet,
* we can't call bio_endio() here, because it will call
* clone_endio() from dm.c, which in turn will
* free the current struct dm_crypt_io structure with
* our tasklet. In this case we need to delay bio_endio()
* execution to after the tasklet is done and dequeued.
*/
if (io->in_tasklet) {
INIT_WORK(&io->work, kcryptd_io_bio_endio);
queue_work(cc->io_queue, &io->work);
return;
}
bio_endio(base_bio);
}
/*
* kcryptd/kcryptd_io:
*
* Needed because it would be very unwise to do decryption in an
* interrupt context.
*
* kcryptd performs the actual encryption or decryption.
*
* kcryptd_io performs the IO submission.
*
* They must be separated as otherwise the final stages could be
* starved by new requests which can block in the first stages due
* to memory allocation.
*
* The work is done per CPU global for all dm-crypt instances.
* They should not depend on each other and do not block.
*/
static void crypt_endio(struct bio *clone)
{
struct dm_crypt_io *io = clone->bi_private;
struct crypt_config *cc = io->cc;
unsigned int rw = bio_data_dir(clone);
blk_status_t error;
/*
* free the processed pages
*/
if (rw == WRITE)
crypt_free_buffer_pages(cc, clone);
error = clone->bi_status;
bio_put(clone);
if (rw == READ && !error) {
kcryptd_queue_crypt(io);
return;
}
if (unlikely(error))
io->error = error;
crypt_dec_pending(io);
}
#define CRYPT_MAP_READ_GFP GFP_NOWAIT
static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
{
struct crypt_config *cc = io->cc;
struct bio *clone;
/*
* We need the original biovec array in order to decrypt the whole bio
* data *afterwards* -- thanks to immutable biovecs we don't need to
* worry about the block layer modifying the biovec array; so leverage
* bio_alloc_clone().
*/
clone = bio_alloc_clone(cc->dev->bdev, io->base_bio, gfp, &cc->bs);
if (!clone)
return 1;
clone->bi_private = io;
clone->bi_end_io = crypt_endio;
crypt_inc_pending(io);
clone->bi_iter.bi_sector = cc->start + io->sector;
if (dm_crypt_integrity_io_alloc(io, clone)) {
crypt_dec_pending(io);
bio_put(clone);
return 1;
}
dm_submit_bio_remap(io->base_bio, clone);
return 0;
}
static void kcryptd_io_read_work(struct work_struct *work)
{
struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
crypt_inc_pending(io);
if (kcryptd_io_read(io, GFP_NOIO))
io->error = BLK_STS_RESOURCE;
crypt_dec_pending(io);
}
static void kcryptd_queue_read(struct dm_crypt_io *io)
{
struct crypt_config *cc = io->cc;
INIT_WORK(&io->work, kcryptd_io_read_work);
queue_work(cc->io_queue, &io->work);
}
static void kcryptd_io_write(struct dm_crypt_io *io)
{
struct bio *clone = io->ctx.bio_out;
dm_submit_bio_remap(io->base_bio, clone);
}
#define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node)
static int dmcrypt_write(void *data)
{
struct crypt_config *cc = data;
struct dm_crypt_io *io;
while (1) {
struct rb_root write_tree;
struct blk_plug plug;
spin_lock_irq(&cc->write_thread_lock);
continue_locked:
if (!RB_EMPTY_ROOT(&cc->write_tree))
goto pop_from_list;
set_current_state(TASK_INTERRUPTIBLE);
spin_unlock_irq(&cc->write_thread_lock);
if (unlikely(kthread_should_stop())) {
set_current_state(TASK_RUNNING);
break;
}
schedule();
set_current_state(TASK_RUNNING);
spin_lock_irq(&cc->write_thread_lock);
goto continue_locked;
pop_from_list:
write_tree = cc->write_tree;
cc->write_tree = RB_ROOT;
spin_unlock_irq(&cc->write_thread_lock);
BUG_ON(rb_parent(write_tree.rb_node));
/*
* Note: we cannot walk the tree here with rb_next because
* the structures may be freed when kcryptd_io_write is called.
*/
blk_start_plug(&plug);
do {
io = crypt_io_from_node(rb_first(&write_tree));
rb_erase(&io->rb_node, &write_tree);
kcryptd_io_write(io);
cond_resched();
} while (!RB_EMPTY_ROOT(&write_tree));
blk_finish_plug(&plug);
}
return 0;
}
static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
{
struct bio *clone = io->ctx.bio_out;
struct crypt_config *cc = io->cc;
unsigned long flags;
sector_t sector;
struct rb_node **rbp, *parent;
if (unlikely(io->error)) {
crypt_free_buffer_pages(cc, clone);
bio_put(clone);
crypt_dec_pending(io);
return;
}
/* crypt_convert should have filled the clone bio */
BUG_ON(io->ctx.iter_out.bi_size);
clone->bi_iter.bi_sector = cc->start + io->sector;
if ((likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) ||
test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags)) {
dm_submit_bio_remap(io->base_bio, clone);
return;
}
spin_lock_irqsave(&cc->write_thread_lock, flags);
if (RB_EMPTY_ROOT(&cc->write_tree))
wake_up_process(cc->write_thread);
rbp = &cc->write_tree.rb_node;
parent = NULL;
sector = io->sector;
while (*rbp) {
parent = *rbp;
if (sector < crypt_io_from_node(parent)->sector)
rbp = &(*rbp)->rb_left;
else
rbp = &(*rbp)->rb_right;
}
rb_link_node(&io->rb_node, parent, rbp);
rb_insert_color(&io->rb_node, &cc->write_tree);
spin_unlock_irqrestore(&cc->write_thread_lock, flags);
}
static bool kcryptd_crypt_write_inline(struct crypt_config *cc,
struct convert_context *ctx)
{
if (!test_bit(DM_CRYPT_WRITE_INLINE, &cc->flags))
return false;
/*
* Note: zone append writes (REQ_OP_ZONE_APPEND) do not have ordering
* constraints so they do not need to be issued inline by
* kcryptd_crypt_write_convert().
*/
switch (bio_op(ctx->bio_in)) {
case REQ_OP_WRITE:
case REQ_OP_WRITE_ZEROES:
return true;
default:
return false;
}
}
static void kcryptd_crypt_write_continue(struct work_struct *work)
{
struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
struct crypt_config *cc = io->cc;
struct convert_context *ctx = &io->ctx;
int crypt_finished;
sector_t sector = io->sector;
blk_status_t r;
wait_for_completion(&ctx->restart);
reinit_completion(&ctx->restart);
r = crypt_convert(cc, &io->ctx, true, false);
if (r)
io->error = r;
crypt_finished = atomic_dec_and_test(&ctx->cc_pending);
if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) {
/* Wait for completion signaled by kcryptd_async_done() */
wait_for_completion(&ctx->restart);
crypt_finished = 1;
}
/* Encryption was already finished, submit io now */
if (crypt_finished) {
kcryptd_crypt_write_io_submit(io, 0);
io->sector = sector;
}
crypt_dec_pending(io);
}
static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
{
struct crypt_config *cc = io->cc;
struct convert_context *ctx = &io->ctx;
struct bio *clone;
int crypt_finished;
sector_t sector = io->sector;
blk_status_t r;
/*
* Prevent io from disappearing until this function completes.
*/
crypt_inc_pending(io);
crypt_convert_init(cc, ctx, NULL, io->base_bio, sector);
clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
if (unlikely(!clone)) {
io->error = BLK_STS_IOERR;
goto dec;
}
io->ctx.bio_out = clone;
io->ctx.iter_out = clone->bi_iter;
sector += bio_sectors(clone);
crypt_inc_pending(io);
r = crypt_convert(cc, ctx,
test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags), true);
/*
* Crypto API backlogged the request, because its queue was full
* and we're in softirq context, so continue from a workqueue
* (TODO: is it actually possible to be in softirq in the write path?)
*/
if (r == BLK_STS_DEV_RESOURCE) {
INIT_WORK(&io->work, kcryptd_crypt_write_continue);
queue_work(cc->crypt_queue, &io->work);
return;
}
if (r)
io->error = r;
crypt_finished = atomic_dec_and_test(&ctx->cc_pending);
if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) {
/* Wait for completion signaled by kcryptd_async_done() */
wait_for_completion(&ctx->restart);
crypt_finished = 1;
}
/* Encryption was already finished, submit io now */
if (crypt_finished) {
kcryptd_crypt_write_io_submit(io, 0);
io->sector = sector;
}
dec:
crypt_dec_pending(io);
}
static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
{
crypt_dec_pending(io);
}
static void kcryptd_crypt_read_continue(struct work_struct *work)
{
struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
struct crypt_config *cc = io->cc;
blk_status_t r;
wait_for_completion(&io->ctx.restart);
reinit_completion(&io->ctx.restart);
r = crypt_convert(cc, &io->ctx, true, false);
if (r)
io->error = r;
if (atomic_dec_and_test(&io->ctx.cc_pending))
kcryptd_crypt_read_done(io);
crypt_dec_pending(io);
}
static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
{
struct crypt_config *cc = io->cc;
blk_status_t r;
crypt_inc_pending(io);
crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
io->sector);
r = crypt_convert(cc, &io->ctx,
test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags), true);
/*
* Crypto API backlogged the request, because its queue was full
* and we're in softirq context, so continue from a workqueue
*/
if (r == BLK_STS_DEV_RESOURCE) {
INIT_WORK(&io->work, kcryptd_crypt_read_continue);
queue_work(cc->crypt_queue, &io->work);
return;
}
if (r)
io->error = r;
if (atomic_dec_and_test(&io->ctx.cc_pending))
kcryptd_crypt_read_done(io);
crypt_dec_pending(io);
}
static void kcryptd_async_done(void *data, int error)
{
struct dm_crypt_request *dmreq = data;
struct convert_context *ctx = dmreq->ctx;
struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
struct crypt_config *cc = io->cc;
/*
* A request from crypto driver backlog is going to be processed now,
* finish the completion and continue in crypt_convert().
* (Callback will be called for the second time for this request.)
*/
if (error == -EINPROGRESS) {
complete(&ctx->restart);
return;
}
if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
error = cc->iv_gen_ops->post(cc, org_iv_of_dmreq(cc, dmreq), dmreq);
if (error == -EBADMSG) {
sector_t s = le64_to_cpu(*org_sector_of_dmreq(cc, dmreq));
DMERR_LIMIT("%pg: INTEGRITY AEAD ERROR, sector %llu",
ctx->bio_in->bi_bdev, s);
dm_audit_log_bio(DM_MSG_PREFIX, "integrity-aead",
ctx->bio_in, s, 0);
io->error = BLK_STS_PROTECTION;
} else if (error < 0)
io->error = BLK_STS_IOERR;
crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
if (!atomic_dec_and_test(&ctx->cc_pending))
return;
/*
* The request is fully completed: for inline writes, let
* kcryptd_crypt_write_convert() do the IO submission.
*/
if (bio_data_dir(io->base_bio) == READ) {
kcryptd_crypt_read_done(io);
return;
}
if (kcryptd_crypt_write_inline(cc, ctx)) {
complete(&ctx->restart);
return;
}
kcryptd_crypt_write_io_submit(io, 1);
}
static void kcryptd_crypt(struct work_struct *work)
{
struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
if (bio_data_dir(io->base_bio) == READ)
kcryptd_crypt_read_convert(io);
else
kcryptd_crypt_write_convert(io);
}
static void kcryptd_crypt_tasklet(unsigned long work)
{
kcryptd_crypt((struct work_struct *)work);
}
static void kcryptd_queue_crypt(struct dm_crypt_io *io)
{
struct crypt_config *cc = io->cc;
if ((bio_data_dir(io->base_bio) == READ && test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags)) ||
(bio_data_dir(io->base_bio) == WRITE && test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags))) {
/*
* in_hardirq(): Crypto API's skcipher_walk_first() refuses to work in hard IRQ context.
* irqs_disabled(): the kernel may run some IO completion from the idle thread, but
* it is being executed with irqs disabled.
*/
if (in_hardirq() || irqs_disabled()) {
io->in_tasklet = true;
tasklet_init(&io->tasklet, kcryptd_crypt_tasklet, (unsigned long)&io->work);
tasklet_schedule(&io->tasklet);
return;
}
kcryptd_crypt(&io->work);
return;
}
INIT_WORK(&io->work, kcryptd_crypt);
queue_work(cc->crypt_queue, &io->work);
}
static void crypt_free_tfms_aead(struct crypt_config *cc)
{
if (!cc->cipher_tfm.tfms_aead)
return;
if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
crypto_free_aead(cc->cipher_tfm.tfms_aead[0]);
cc->cipher_tfm.tfms_aead[0] = NULL;
}
kfree(cc->cipher_tfm.tfms_aead);
cc->cipher_tfm.tfms_aead = NULL;
}
static void crypt_free_tfms_skcipher(struct crypt_config *cc)
{
unsigned int i;
if (!cc->cipher_tfm.tfms)
return;
for (i = 0; i < cc->tfms_count; i++)
if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) {
crypto_free_skcipher(cc->cipher_tfm.tfms[i]);
cc->cipher_tfm.tfms[i] = NULL;
}
kfree(cc->cipher_tfm.tfms);
cc->cipher_tfm.tfms = NULL;
}
static void crypt_free_tfms(struct crypt_config *cc)
{
if (crypt_integrity_aead(cc))
crypt_free_tfms_aead(cc);
else
crypt_free_tfms_skcipher(cc);
}
static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode)
{
unsigned int i;
int err;
cc->cipher_tfm.tfms = kcalloc(cc->tfms_count,
sizeof(struct crypto_skcipher *),
GFP_KERNEL);
if (!cc->cipher_tfm.tfms)
return -ENOMEM;
for (i = 0; i < cc->tfms_count; i++) {
cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0,
CRYPTO_ALG_ALLOCATES_MEMORY);
if (IS_ERR(cc->cipher_tfm.tfms[i])) {
err = PTR_ERR(cc->cipher_tfm.tfms[i]);
crypt_free_tfms(cc);
return err;
}
}
/*
* dm-crypt performance can vary greatly depending on which crypto
* algorithm implementation is used. Help people debug performance
* problems by logging the ->cra_driver_name.
*/
DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode,
crypto_skcipher_alg(any_tfm(cc))->base.cra_driver_name);
return 0;
}
static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode)
{
int err;
cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL);
if (!cc->cipher_tfm.tfms)
return -ENOMEM;
cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0,
CRYPTO_ALG_ALLOCATES_MEMORY);
if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]);
crypt_free_tfms(cc);
return err;
}
DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode,
crypto_aead_alg(any_tfm_aead(cc))->base.cra_driver_name);
return 0;
}
static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
{
if (crypt_integrity_aead(cc))
return crypt_alloc_tfms_aead(cc, ciphermode);
else
return crypt_alloc_tfms_skcipher(cc, ciphermode);
}
static unsigned int crypt_subkey_size(struct crypt_config *cc)
{
return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
}
static unsigned int crypt_authenckey_size(struct crypt_config *cc)
{
return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param));
}
/*
* If AEAD is composed like authenc(hmac(sha256),xts(aes)),
* the key must be for some reason in special format.
* This funcion converts cc->key to this special format.
*/
static void crypt_copy_authenckey(char *p, const void *key,
unsigned int enckeylen, unsigned int authkeylen)
{
struct crypto_authenc_key_param *param;
struct rtattr *rta;
rta = (struct rtattr *)p;
param = RTA_DATA(rta);
param->enckeylen = cpu_to_be32(enckeylen);
rta->rta_len = RTA_LENGTH(sizeof(*param));
rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
p += RTA_SPACE(sizeof(*param));
memcpy(p, key + enckeylen, authkeylen);
p += authkeylen;
memcpy(p, key, enckeylen);
}
static int crypt_setkey(struct crypt_config *cc)
{
unsigned int subkey_size;
int err = 0, i, r;
/* Ignore extra keys (which are used for IV etc) */
subkey_size = crypt_subkey_size(cc);
if (crypt_integrity_hmac(cc)) {
if (subkey_size < cc->key_mac_size)
return -EINVAL;
crypt_copy_authenckey(cc->authenc_key, cc->key,
subkey_size - cc->key_mac_size,
cc->key_mac_size);
}
for (i = 0; i < cc->tfms_count; i++) {
if (crypt_integrity_hmac(cc))
r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
cc->authenc_key, crypt_authenckey_size(cc));
else if (crypt_integrity_aead(cc))
r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
cc->key + (i * subkey_size),
subkey_size);
else
r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i],
cc->key + (i * subkey_size),
subkey_size);
if (r)
err = r;
}
if (crypt_integrity_hmac(cc))
memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc));
return err;
}
#ifdef CONFIG_KEYS
static bool contains_whitespace(const char *str)
{
while (*str)
if (isspace(*str++))
return true;
return false;
}
static int set_key_user(struct crypt_config *cc, struct key *key)
{
const struct user_key_payload *ukp;
ukp = user_key_payload_locked(key);
if (!ukp)
return -EKEYREVOKED;
if (cc->key_size != ukp->datalen)
return -EINVAL;
memcpy(cc->key, ukp->data, cc->key_size);
return 0;
}
static int set_key_encrypted(struct crypt_config *cc, struct key *key)
{
const struct encrypted_key_payload *ekp;
ekp = key->payload.data[0];
if (!ekp)
return -EKEYREVOKED;
if (cc->key_size != ekp->decrypted_datalen)
return -EINVAL;
memcpy(cc->key, ekp->decrypted_data, cc->key_size);
return 0;
}
static int set_key_trusted(struct crypt_config *cc, struct key *key)
{
const struct trusted_key_payload *tkp;
tkp = key->payload.data[0];
if (!tkp)
return -EKEYREVOKED;
if (cc->key_size != tkp->key_len)
return -EINVAL;
memcpy(cc->key, tkp->key, cc->key_size);
return 0;
}
static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
{
char *new_key_string, *key_desc;
int ret;
struct key_type *type;
struct key *key;
int (*set_key)(struct crypt_config *cc, struct key *key);
/*
* Reject key_string with whitespace. dm core currently lacks code for
* proper whitespace escaping in arguments on DM_TABLE_STATUS path.
*/
if (contains_whitespace(key_string)) {
DMERR("whitespace chars not allowed in key string");
return -EINVAL;
}
/* look for next ':' separating key_type from key_description */
key_desc = strchr(key_string, ':');
if (!key_desc || key_desc == key_string || !strlen(key_desc + 1))
return -EINVAL;
if (!strncmp(key_string, "logon:", key_desc - key_string + 1)) {
type = &key_type_logon;
set_key = set_key_user;
} else if (!strncmp(key_string, "user:", key_desc - key_string + 1)) {
type = &key_type_user;
set_key = set_key_user;
} else if (IS_ENABLED(CONFIG_ENCRYPTED_KEYS) &&
!strncmp(key_string, "encrypted:", key_desc - key_string + 1)) {
type = &key_type_encrypted;
set_key = set_key_encrypted;
} else if (IS_ENABLED(CONFIG_TRUSTED_KEYS) &&
!strncmp(key_string, "trusted:", key_desc - key_string + 1)) {
type = &key_type_trusted;
set_key = set_key_trusted;
} else {
return -EINVAL;
}
new_key_string = kstrdup(key_string, GFP_KERNEL);
if (!new_key_string)
return -ENOMEM;
key = request_key(type, key_desc + 1, NULL);
if (IS_ERR(key)) {
kfree_sensitive(new_key_string);
return PTR_ERR(key);
}
down_read(&key->sem);
ret = set_key(cc, key);
if (ret < 0) {
up_read(&key->sem);
key_put(key);
kfree_sensitive(new_key_string);
return ret;
}
up_read(&key->sem);
key_put(key);
/* clear the flag since following operations may invalidate previously valid key */
clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
ret = crypt_setkey(cc);
if (!ret) {
set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
kfree_sensitive(cc->key_string);
cc->key_string = new_key_string;
} else
kfree_sensitive(new_key_string);
return ret;
}
static int get_key_size(char **key_string)
{
char *colon, dummy;
int ret;
if (*key_string[0] != ':')
return strlen(*key_string) >> 1;
/* look for next ':' in key string */
colon = strpbrk(*key_string + 1, ":");
if (!colon)
return -EINVAL;
if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':')
return -EINVAL;
*key_string = colon;
/* remaining key string should be :<logon|user>:<key_desc> */
return ret;
}
#else
static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
{
return -EINVAL;
}
static int get_key_size(char **key_string)
{
return (*key_string[0] == ':') ? -EINVAL : (int)(strlen(*key_string) >> 1);
}
#endif /* CONFIG_KEYS */
static int crypt_set_key(struct crypt_config *cc, char *key)
{
int r = -EINVAL;
int key_string_len = strlen(key);
/* Hyphen (which gives a key_size of zero) means there is no key. */
if (!cc->key_size && strcmp(key, "-"))
goto out;
/* ':' means the key is in kernel keyring, short-circuit normal key processing */
if (key[0] == ':') {
r = crypt_set_keyring_key(cc, key + 1);
goto out;
}
/* clear the flag since following operations may invalidate previously valid key */
clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
/* wipe references to any kernel keyring key */
kfree_sensitive(cc->key_string);
cc->key_string = NULL;
/* Decode key from its hex representation. */
if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0)
goto out;
r = crypt_setkey(cc);
if (!r)
set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
out:
/* Hex key string not needed after here, so wipe it. */
memset(key, '0', key_string_len);
return r;
}
static int crypt_wipe_key(struct crypt_config *cc)
{
int r;
clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
get_random_bytes(&cc->key, cc->key_size);
/* Wipe IV private keys */
if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
r = cc->iv_gen_ops->wipe(cc);
if (r)
return r;
}
kfree_sensitive(cc->key_string);
cc->key_string = NULL;
r = crypt_setkey(cc);
memset(&cc->key, 0, cc->key_size * sizeof(u8));
return r;
}
static void crypt_calculate_pages_per_client(void)
{
unsigned long pages = (totalram_pages() - totalhigh_pages()) * DM_CRYPT_MEMORY_PERCENT / 100;
if (!dm_crypt_clients_n)
return;
pages /= dm_crypt_clients_n;
if (pages < DM_CRYPT_MIN_PAGES_PER_CLIENT)
pages = DM_CRYPT_MIN_PAGES_PER_CLIENT;
dm_crypt_pages_per_client = pages;
}
static void *crypt_page_alloc(gfp_t gfp_mask, void *pool_data)
{
struct crypt_config *cc = pool_data;
struct page *page;
/*
* Note, percpu_counter_read_positive() may over (and under) estimate
* the current usage by at most (batch - 1) * num_online_cpus() pages,
* but avoids potential spinlock contention of an exact result.
*/
if (unlikely(percpu_counter_read_positive(&cc->n_allocated_pages) >= dm_crypt_pages_per_client) &&
likely(gfp_mask & __GFP_NORETRY))
return NULL;
page = alloc_page(gfp_mask);
if (likely(page != NULL))
percpu_counter_add(&cc->n_allocated_pages, 1);
return page;
}
static void crypt_page_free(void *page, void *pool_data)
{
struct crypt_config *cc = pool_data;
__free_page(page);
percpu_counter_sub(&cc->n_allocated_pages, 1);
}
static void crypt_dtr(struct dm_target *ti)
{
struct crypt_config *cc = ti->private;
ti->private = NULL;
if (!cc)
return;
if (cc->write_thread)
kthread_stop(cc->write_thread);
if (cc->io_queue)
destroy_workqueue(cc->io_queue);
if (cc->crypt_queue)
destroy_workqueue(cc->crypt_queue);
crypt_free_tfms(cc);
bioset_exit(&cc->bs);
mempool_exit(&cc->page_pool);
mempool_exit(&cc->req_pool);
mempool_exit(&cc->tag_pool);
WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0);
percpu_counter_destroy(&cc->n_allocated_pages);
if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
cc->iv_gen_ops->dtr(cc);
if (cc->dev)
dm_put_device(ti, cc->dev);
kfree_sensitive(cc->cipher_string);
kfree_sensitive(cc->key_string);
kfree_sensitive(cc->cipher_auth);
kfree_sensitive(cc->authenc_key);
mutex_destroy(&cc->bio_alloc_lock);
/* Must zero key material before freeing */
kfree_sensitive(cc);
spin_lock(&dm_crypt_clients_lock);
WARN_ON(!dm_crypt_clients_n);
dm_crypt_clients_n--;
crypt_calculate_pages_per_client();
spin_unlock(&dm_crypt_clients_lock);
dm_audit_log_dtr(DM_MSG_PREFIX, ti, 1);
}
static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode)
{
struct crypt_config *cc = ti->private;
if (crypt_integrity_aead(cc))
cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
else
cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
if (cc->iv_size)
/* at least a 64 bit sector number should fit in our buffer */
cc->iv_size = max(cc->iv_size,
(unsigned int)(sizeof(u64) / sizeof(u8)));
else if (ivmode) {
DMWARN("Selected cipher does not support IVs");
ivmode = NULL;
}
/* Choose ivmode, see comments at iv code. */
if (ivmode == NULL)
cc->iv_gen_ops = NULL;
else if (strcmp(ivmode, "plain") == 0)
cc->iv_gen_ops = &crypt_iv_plain_ops;
else if (strcmp(ivmode, "plain64") == 0)
cc->iv_gen_ops = &crypt_iv_plain64_ops;
else if (strcmp(ivmode, "plain64be") == 0)
cc->iv_gen_ops = &crypt_iv_plain64be_ops;
else if (strcmp(ivmode, "essiv") == 0)
cc->iv_gen_ops = &crypt_iv_essiv_ops;
else if (strcmp(ivmode, "benbi") == 0)
cc->iv_gen_ops = &crypt_iv_benbi_ops;
else if (strcmp(ivmode, "null") == 0)
cc->iv_gen_ops = &crypt_iv_null_ops;
else if (strcmp(ivmode, "eboiv") == 0)
cc->iv_gen_ops = &crypt_iv_eboiv_ops;
else if (strcmp(ivmode, "elephant") == 0) {
cc->iv_gen_ops = &crypt_iv_elephant_ops;
cc->key_parts = 2;
cc->key_extra_size = cc->key_size / 2;
if (cc->key_extra_size > ELEPHANT_MAX_KEY_SIZE)
return -EINVAL;
set_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags);
} else if (strcmp(ivmode, "lmk") == 0) {
cc->iv_gen_ops = &crypt_iv_lmk_ops;
/*
* Version 2 and 3 is recognised according
* to length of provided multi-key string.
* If present (version 3), last key is used as IV seed.
* All keys (including IV seed) are always the same size.
*/
if (cc->key_size % cc->key_parts) {
cc->key_parts++;
cc->key_extra_size = cc->key_size / cc->key_parts;
}
} else if (strcmp(ivmode, "tcw") == 0) {
cc->iv_gen_ops = &crypt_iv_tcw_ops;
cc->key_parts += 2; /* IV + whitening */
cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
} else if (strcmp(ivmode, "random") == 0) {
cc->iv_gen_ops = &crypt_iv_random_ops;
/* Need storage space in integrity fields. */
cc->integrity_iv_size = cc->iv_size;
} else {
ti->error = "Invalid IV mode";
return -EINVAL;
}
return 0;
}
/*
* Workaround to parse HMAC algorithm from AEAD crypto API spec.
* The HMAC is needed to calculate tag size (HMAC digest size).
* This should be probably done by crypto-api calls (once available...)
*/
static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api)
{
char *start, *end, *mac_alg = NULL;
struct crypto_ahash *mac;
if (!strstarts(cipher_api, "authenc("))
return 0;
start = strchr(cipher_api, '(');
end = strchr(cipher_api, ',');
if (!start || !end || ++start > end)
return -EINVAL;
mac_alg = kzalloc(end - start + 1, GFP_KERNEL);
if (!mac_alg)
return -ENOMEM;
strncpy(mac_alg, start, end - start);
mac = crypto_alloc_ahash(mac_alg, 0, CRYPTO_ALG_ALLOCATES_MEMORY);
kfree(mac_alg);
if (IS_ERR(mac))
return PTR_ERR(mac);
cc->key_mac_size = crypto_ahash_digestsize(mac);
crypto_free_ahash(mac);
cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL);
if (!cc->authenc_key)
return -ENOMEM;
return 0;
}
static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key,
char **ivmode, char **ivopts)
{
struct crypt_config *cc = ti->private;
char *tmp, *cipher_api, buf[CRYPTO_MAX_ALG_NAME];
int ret = -EINVAL;
cc->tfms_count = 1;
/*
* New format (capi: prefix)
* capi:cipher_api_spec-iv:ivopts
*/
tmp = &cipher_in[strlen("capi:")];
/* Separate IV options if present, it can contain another '-' in hash name */
*ivopts = strrchr(tmp, ':');
if (*ivopts) {
**ivopts = '\0';
(*ivopts)++;
}
/* Parse IV mode */
*ivmode = strrchr(tmp, '-');
if (*ivmode) {
**ivmode = '\0';
(*ivmode)++;
}
/* The rest is crypto API spec */
cipher_api = tmp;
/* Alloc AEAD, can be used only in new format. */
if (crypt_integrity_aead(cc)) {
ret = crypt_ctr_auth_cipher(cc, cipher_api);
if (ret < 0) {
ti->error = "Invalid AEAD cipher spec";
return ret;
}
}
if (*ivmode && !strcmp(*ivmode, "lmk"))
cc->tfms_count = 64;
if (*ivmode && !strcmp(*ivmode, "essiv")) {
if (!*ivopts) {
ti->error = "Digest algorithm missing for ESSIV mode";
return -EINVAL;
}
ret = snprintf(buf, CRYPTO_MAX_ALG_NAME, "essiv(%s,%s)",
cipher_api, *ivopts);
if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) {
ti->error = "Cannot allocate cipher string";
return -ENOMEM;
}
cipher_api = buf;
}
cc->key_parts = cc->tfms_count;
/* Allocate cipher */
ret = crypt_alloc_tfms(cc, cipher_api);
if (ret < 0) {
ti->error = "Error allocating crypto tfm";
return ret;
}
if (crypt_integrity_aead(cc))
cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
else
cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
return 0;
}
static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key,
char **ivmode, char **ivopts)
{
struct crypt_config *cc = ti->private;
char *tmp, *cipher, *chainmode, *keycount;
char *cipher_api = NULL;
int ret = -EINVAL;
char dummy;
if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) {
ti->error = "Bad cipher specification";
return -EINVAL;
}
/*
* Legacy dm-crypt cipher specification
* cipher[:keycount]-mode-iv:ivopts
*/
tmp = cipher_in;
keycount = strsep(&tmp, "-");
cipher = strsep(&keycount, ":");
if (!keycount)
cc->tfms_count = 1;
else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
!is_power_of_2(cc->tfms_count)) {
ti->error = "Bad cipher key count specification";
return -EINVAL;
}
cc->key_parts = cc->tfms_count;
chainmode = strsep(&tmp, "-");
*ivmode = strsep(&tmp, ":");
*ivopts = tmp;
/*
* For compatibility with the original dm-crypt mapping format, if
* only the cipher name is supplied, use cbc-plain.
*/
if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) {
chainmode = "cbc";
*ivmode = "plain";
}
if (strcmp(chainmode, "ecb") && !*ivmode) {
ti->error = "IV mechanism required";
return -EINVAL;
}
cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
if (!cipher_api)
goto bad_mem;
if (*ivmode && !strcmp(*ivmode, "essiv")) {
if (!*ivopts) {
ti->error = "Digest algorithm missing for ESSIV mode";
kfree(cipher_api);
return -EINVAL;
}
ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
"essiv(%s(%s),%s)", chainmode, cipher, *ivopts);
} else {
ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
"%s(%s)", chainmode, cipher);
}
if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) {
kfree(cipher_api);
goto bad_mem;
}
/* Allocate cipher */
ret = crypt_alloc_tfms(cc, cipher_api);
if (ret < 0) {
ti->error = "Error allocating crypto tfm";
kfree(cipher_api);
return ret;
}
kfree(cipher_api);
return 0;
bad_mem:
ti->error = "Cannot allocate cipher strings";
return -ENOMEM;
}
static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key)
{
struct crypt_config *cc = ti->private;
char *ivmode = NULL, *ivopts = NULL;
int ret;
cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
if (!cc->cipher_string) {
ti->error = "Cannot allocate cipher strings";
return -ENOMEM;
}
if (strstarts(cipher_in, "capi:"))
ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts);
else
ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts);
if (ret)
return ret;
/* Initialize IV */
ret = crypt_ctr_ivmode(ti, ivmode);
if (ret < 0)
return ret;
/* Initialize and set key */
ret = crypt_set_key(cc, key);
if (ret < 0) {
ti->error = "Error decoding and setting key";
return ret;
}
/* Allocate IV */
if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
if (ret < 0) {
ti->error = "Error creating IV";
return ret;
}
}
/* Initialize IV (set keys for ESSIV etc) */
if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
ret = cc->iv_gen_ops->init(cc);
if (ret < 0) {
ti->error = "Error initialising IV";
return ret;
}
}
/* wipe the kernel key payload copy */
if (cc->key_string)
memset(cc->key, 0, cc->key_size * sizeof(u8));
return ret;
}
static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv)
{
struct crypt_config *cc = ti->private;
struct dm_arg_set as;
static const struct dm_arg _args[] = {
{0, 8, "Invalid number of feature args"},
};
unsigned int opt_params, val;
const char *opt_string, *sval;
char dummy;
int ret;
/* Optional parameters */
as.argc = argc;
as.argv = argv;
ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
if (ret)
return ret;
while (opt_params--) {
opt_string = dm_shift_arg(&as);
if (!opt_string) {
ti->error = "Not enough feature arguments";
return -EINVAL;
}
if (!strcasecmp(opt_string, "allow_discards"))
ti->num_discard_bios = 1;
else if (!strcasecmp(opt_string, "same_cpu_crypt"))
set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
else if (!strcasecmp(opt_string, "submit_from_crypt_cpus"))
set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
else if (!strcasecmp(opt_string, "no_read_workqueue"))
set_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags);
else if (!strcasecmp(opt_string, "no_write_workqueue"))
set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
else if (sscanf(opt_string, "integrity:%u:", &val) == 1) {
if (val == 0 || val > MAX_TAG_SIZE) {
ti->error = "Invalid integrity arguments";
return -EINVAL;
}
cc->on_disk_tag_size = val;
sval = strchr(opt_string + strlen("integrity:"), ':') + 1;
if (!strcasecmp(sval, "aead")) {
set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
} else if (strcasecmp(sval, "none")) {
ti->error = "Unknown integrity profile";
return -EINVAL;
}
cc->cipher_auth = kstrdup(sval, GFP_KERNEL);
if (!cc->cipher_auth)
return -ENOMEM;
} else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) {
if (cc->sector_size < (1 << SECTOR_SHIFT) ||
cc->sector_size > 4096 ||
(cc->sector_size & (cc->sector_size - 1))) {
ti->error = "Invalid feature value for sector_size";
return -EINVAL;
}
if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) {
ti->error = "Device size is not multiple of sector_size feature";
return -EINVAL;
}
cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT;
} else if (!strcasecmp(opt_string, "iv_large_sectors"))
set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
else {
ti->error = "Invalid feature arguments";
return -EINVAL;
}
}
return 0;
}
#ifdef CONFIG_BLK_DEV_ZONED
static int crypt_report_zones(struct dm_target *ti,
struct dm_report_zones_args *args, unsigned int nr_zones)
{
struct crypt_config *cc = ti->private;
return dm_report_zones(cc->dev->bdev, cc->start,
cc->start + dm_target_offset(ti, args->next_sector),
args, nr_zones);
}
#else
#define crypt_report_zones NULL
#endif
/*
* Construct an encryption mapping:
* <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start>
*/
static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
struct crypt_config *cc;
const char *devname = dm_table_device_name(ti->table);
int key_size;
unsigned int align_mask;
unsigned long long tmpll;
int ret;
size_t iv_size_padding, additional_req_size;
char dummy;
if (argc < 5) {
ti->error = "Not enough arguments";
return -EINVAL;
}
key_size = get_key_size(&argv[1]);
if (key_size < 0) {
ti->error = "Cannot parse key size";
return -EINVAL;
}
cc = kzalloc(struct_size(cc, key, key_size), GFP_KERNEL);
if (!cc) {
ti->error = "Cannot allocate encryption context";
return -ENOMEM;
}
cc->key_size = key_size;
cc->sector_size = (1 << SECTOR_SHIFT);
cc->sector_shift = 0;
ti->private = cc;
spin_lock(&dm_crypt_clients_lock);
dm_crypt_clients_n++;
crypt_calculate_pages_per_client();
spin_unlock(&dm_crypt_clients_lock);
ret = percpu_counter_init(&cc->n_allocated_pages, 0, GFP_KERNEL);
if (ret < 0)
goto bad;
/* Optional parameters need to be read before cipher constructor */
if (argc > 5) {
ret = crypt_ctr_optional(ti, argc - 5, &argv[5]);
if (ret)
goto bad;
}
ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
if (ret < 0)
goto bad;
if (crypt_integrity_aead(cc)) {
cc->dmreq_start = sizeof(struct aead_request);
cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc));
align_mask = crypto_aead_alignmask(any_tfm_aead(cc));
} else {
cc->dmreq_start = sizeof(struct skcipher_request);
cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc));
align_mask = crypto_skcipher_alignmask(any_tfm(cc));
}
cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
if (align_mask < CRYPTO_MINALIGN) {
/* Allocate the padding exactly */
iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
& align_mask;
} else {
/*
* If the cipher requires greater alignment than kmalloc
* alignment, we don't know the exact position of the
* initialization vector. We must assume worst case.
*/
iv_size_padding = align_mask;
}
/* ...| IV + padding | original IV | original sec. number | bio tag offset | */
additional_req_size = sizeof(struct dm_crypt_request) +
iv_size_padding + cc->iv_size +
cc->iv_size +
sizeof(uint64_t) +
sizeof(unsigned int);
ret = mempool_init_kmalloc_pool(&cc->req_pool, MIN_IOS, cc->dmreq_start + additional_req_size);
if (ret) {
ti->error = "Cannot allocate crypt request mempool";
goto bad;
}
cc->per_bio_data_size = ti->per_io_data_size =
ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size,
ARCH_DMA_MINALIGN);
ret = mempool_init(&cc->page_pool, BIO_MAX_VECS, crypt_page_alloc, crypt_page_free, cc);
if (ret) {
ti->error = "Cannot allocate page mempool";
goto bad;
}
ret = bioset_init(&cc->bs, MIN_IOS, 0, BIOSET_NEED_BVECS);
if (ret) {
ti->error = "Cannot allocate crypt bioset";
goto bad;
}
mutex_init(&cc->bio_alloc_lock);
ret = -EINVAL;
if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) ||
(tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) {
ti->error = "Invalid iv_offset sector";
goto bad;
}
cc->iv_offset = tmpll;
ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev);
if (ret) {
ti->error = "Device lookup failed";
goto bad;
}
ret = -EINVAL;
if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) {
ti->error = "Invalid device sector";
goto bad;
}
cc->start = tmpll;
if (bdev_is_zoned(cc->dev->bdev)) {
/*
* For zoned block devices, we need to preserve the issuer write
* ordering. To do so, disable write workqueues and force inline
* encryption completion.
*/
set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
set_bit(DM_CRYPT_WRITE_INLINE, &cc->flags);
/*
* All zone append writes to a zone of a zoned block device will
* have the same BIO sector, the start of the zone. When the
* cypher IV mode uses sector values, all data targeting a
* zone will be encrypted using the first sector numbers of the
* zone. This will not result in write errors but will
* cause most reads to fail as reads will use the sector values
* for the actual data locations, resulting in IV mismatch.
* To avoid this problem, ask DM core to emulate zone append
* operations with regular writes.
*/
DMDEBUG("Zone append operations will be emulated");
ti->emulate_zone_append = true;
}
if (crypt_integrity_aead(cc) || cc->integrity_iv_size) {
ret = crypt_integrity_ctr(cc, ti);
if (ret)
goto bad;
cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size;
if (!cc->tag_pool_max_sectors)
cc->tag_pool_max_sectors = 1;
ret = mempool_init_kmalloc_pool(&cc->tag_pool, MIN_IOS,
cc->tag_pool_max_sectors * cc->on_disk_tag_size);
if (ret) {
ti->error = "Cannot allocate integrity tags mempool";
goto bad;
}
cc->tag_pool_max_sectors <<= cc->sector_shift;
}
ret = -ENOMEM;
cc->io_queue = alloc_workqueue("kcryptd_io/%s", WQ_MEM_RECLAIM, 1, devname);
if (!cc->io_queue) {
ti->error = "Couldn't create kcryptd io queue";
goto bad;
}
if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
cc->crypt_queue = alloc_workqueue("kcryptd/%s", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM,
1, devname);
else
cc->crypt_queue = alloc_workqueue("kcryptd/%s",
WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
num_online_cpus(), devname);
if (!cc->crypt_queue) {
ti->error = "Couldn't create kcryptd queue";
goto bad;
}
spin_lock_init(&cc->write_thread_lock);
cc->write_tree = RB_ROOT;
cc->write_thread = kthread_run(dmcrypt_write, cc, "dmcrypt_write/%s", devname);
if (IS_ERR(cc->write_thread)) {
ret = PTR_ERR(cc->write_thread);
cc->write_thread = NULL;
ti->error = "Couldn't spawn write thread";
goto bad;
}
ti->num_flush_bios = 1;
ti->limit_swap_bios = true;
ti->accounts_remapped_io = true;
dm_audit_log_ctr(DM_MSG_PREFIX, ti, 1);
return 0;
bad:
dm_audit_log_ctr(DM_MSG_PREFIX, ti, 0);
crypt_dtr(ti);
return ret;
}
static int crypt_map(struct dm_target *ti, struct bio *bio)
{
struct dm_crypt_io *io;
struct crypt_config *cc = ti->private;
/*
* If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues.
* - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight
* - for REQ_OP_DISCARD caller must use flush if IO ordering matters
*/
if (unlikely(bio->bi_opf & REQ_PREFLUSH ||
bio_op(bio) == REQ_OP_DISCARD)) {
bio_set_dev(bio, cc->dev->bdev);
if (bio_sectors(bio))
bio->bi_iter.bi_sector = cc->start +
dm_target_offset(ti, bio->bi_iter.bi_sector);
return DM_MAPIO_REMAPPED;
}
/*
* Check if bio is too large, split as needed.
*/
if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_VECS << PAGE_SHIFT)) &&
(bio_data_dir(bio) == WRITE || cc->on_disk_tag_size))
dm_accept_partial_bio(bio, ((BIO_MAX_VECS << PAGE_SHIFT) >> SECTOR_SHIFT));
/*
* Ensure that bio is a multiple of internal sector encryption size
* and is aligned to this size as defined in IO hints.
*/
if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0))
return DM_MAPIO_KILL;
if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1)))
return DM_MAPIO_KILL;
io = dm_per_bio_data(bio, cc->per_bio_data_size);
crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
if (cc->on_disk_tag_size) {
unsigned int tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift);
if (unlikely(tag_len > KMALLOC_MAX_SIZE))
io->integrity_metadata = NULL;
else
io->integrity_metadata = kmalloc(tag_len, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
if (unlikely(!io->integrity_metadata)) {
if (bio_sectors(bio) > cc->tag_pool_max_sectors)
dm_accept_partial_bio(bio, cc->tag_pool_max_sectors);
io->integrity_metadata = mempool_alloc(&cc->tag_pool, GFP_NOIO);
io->integrity_metadata_from_pool = true;
}
}
if (crypt_integrity_aead(cc))
io->ctx.r.req_aead = (struct aead_request *)(io + 1);
else
io->ctx.r.req = (struct skcipher_request *)(io + 1);
if (bio_data_dir(io->base_bio) == READ) {
if (kcryptd_io_read(io, CRYPT_MAP_READ_GFP))
kcryptd_queue_read(io);
} else
kcryptd_queue_crypt(io);
return DM_MAPIO_SUBMITTED;
}
static char hex2asc(unsigned char c)
{
return c + '0' + ((unsigned int)(9 - c) >> 4 & 0x27);
}
static void crypt_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
struct crypt_config *cc = ti->private;
unsigned int i, sz = 0;
int num_feature_args = 0;
switch (type) {
case STATUSTYPE_INFO:
result[0] = '\0';
break;
case STATUSTYPE_TABLE:
DMEMIT("%s ", cc->cipher_string);
if (cc->key_size > 0) {
if (cc->key_string)
DMEMIT(":%u:%s", cc->key_size, cc->key_string);
else {
for (i = 0; i < cc->key_size; i++) {
DMEMIT("%c%c", hex2asc(cc->key[i] >> 4),
hex2asc(cc->key[i] & 0xf));
}
}
} else
DMEMIT("-");
DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
cc->dev->name, (unsigned long long)cc->start);
num_feature_args += !!ti->num_discard_bios;
num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
num_feature_args += test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags);
num_feature_args += test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT);
num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
if (cc->on_disk_tag_size)
num_feature_args++;
if (num_feature_args) {
DMEMIT(" %d", num_feature_args);
if (ti->num_discard_bios)
DMEMIT(" allow_discards");
if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
DMEMIT(" same_cpu_crypt");
if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags))
DMEMIT(" submit_from_crypt_cpus");
if (test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags))
DMEMIT(" no_read_workqueue");
if (test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags))
DMEMIT(" no_write_workqueue");
if (cc->on_disk_tag_size)
DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth);
if (cc->sector_size != (1 << SECTOR_SHIFT))
DMEMIT(" sector_size:%d", cc->sector_size);
if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
DMEMIT(" iv_large_sectors");
}
break;
case STATUSTYPE_IMA:
DMEMIT_TARGET_NAME_VERSION(ti->type);
DMEMIT(",allow_discards=%c", ti->num_discard_bios ? 'y' : 'n');
DMEMIT(",same_cpu_crypt=%c", test_bit(DM_CRYPT_SAME_CPU, &cc->flags) ? 'y' : 'n');
DMEMIT(",submit_from_crypt_cpus=%c", test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags) ?
'y' : 'n');
DMEMIT(",no_read_workqueue=%c", test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags) ?
'y' : 'n');
DMEMIT(",no_write_workqueue=%c", test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags) ?
'y' : 'n');
DMEMIT(",iv_large_sectors=%c", test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags) ?
'y' : 'n');
if (cc->on_disk_tag_size)
DMEMIT(",integrity_tag_size=%u,cipher_auth=%s",
cc->on_disk_tag_size, cc->cipher_auth);
if (cc->sector_size != (1 << SECTOR_SHIFT))
DMEMIT(",sector_size=%d", cc->sector_size);
if (cc->cipher_string)
DMEMIT(",cipher_string=%s", cc->cipher_string);
DMEMIT(",key_size=%u", cc->key_size);
DMEMIT(",key_parts=%u", cc->key_parts);
DMEMIT(",key_extra_size=%u", cc->key_extra_size);
DMEMIT(",key_mac_size=%u", cc->key_mac_size);
DMEMIT(";");
break;
}
}
static void crypt_postsuspend(struct dm_target *ti)
{
struct crypt_config *cc = ti->private;
set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
}
static int crypt_preresume(struct dm_target *ti)
{
struct crypt_config *cc = ti->private;
if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
DMERR("aborting resume - crypt key is not set.");
return -EAGAIN;
}
return 0;
}
static void crypt_resume(struct dm_target *ti)
{
struct crypt_config *cc = ti->private;
clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
}
/* Message interface
* key set <key>
* key wipe
*/
static int crypt_message(struct dm_target *ti, unsigned int argc, char **argv,
char *result, unsigned int maxlen)
{
struct crypt_config *cc = ti->private;
int key_size, ret = -EINVAL;
if (argc < 2)
goto error;
if (!strcasecmp(argv[0], "key")) {
if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
DMWARN("not suspended during key manipulation.");
return -EINVAL;
}
if (argc == 3 && !strcasecmp(argv[1], "set")) {
/* The key size may not be changed. */
key_size = get_key_size(&argv[2]);
if (key_size < 0 || cc->key_size != key_size) {
memset(argv[2], '0', strlen(argv[2]));
return -EINVAL;
}
ret = crypt_set_key(cc, argv[2]);
if (ret)
return ret;
if (cc->iv_gen_ops && cc->iv_gen_ops->init)
ret = cc->iv_gen_ops->init(cc);
/* wipe the kernel key payload copy */
if (cc->key_string)
memset(cc->key, 0, cc->key_size * sizeof(u8));
return ret;
}
if (argc == 2 && !strcasecmp(argv[1], "wipe"))
return crypt_wipe_key(cc);
}
error:
DMWARN("unrecognised message received.");
return -EINVAL;
}
static int crypt_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct crypt_config *cc = ti->private;
return fn(ti, cc->dev, cc->start, ti->len, data);
}
static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
struct crypt_config *cc = ti->private;
/*
* Unfortunate constraint that is required to avoid the potential
* for exceeding underlying device's max_segments limits -- due to
* crypt_alloc_buffer() possibly allocating pages for the encryption
* bio that are not as physically contiguous as the original bio.
*/
limits->max_segment_size = PAGE_SIZE;
limits->logical_block_size =
max_t(unsigned int, limits->logical_block_size, cc->sector_size);
limits->physical_block_size =
max_t(unsigned int, limits->physical_block_size, cc->sector_size);
limits->io_min = max_t(unsigned int, limits->io_min, cc->sector_size);
limits->dma_alignment = limits->logical_block_size - 1;
}
static struct target_type crypt_target = {
.name = "crypt",
.version = {1, 24, 0},
.module = THIS_MODULE,
.ctr = crypt_ctr,
.dtr = crypt_dtr,
.features = DM_TARGET_ZONED_HM,
.report_zones = crypt_report_zones,
.map = crypt_map,
.status = crypt_status,
.postsuspend = crypt_postsuspend,
.preresume = crypt_preresume,
.resume = crypt_resume,
.message = crypt_message,
.iterate_devices = crypt_iterate_devices,
.io_hints = crypt_io_hints,
};
module_dm(crypt);
MODULE_AUTHOR("Jana Saout <[email protected]>");
MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-crypt.c |
// SPDX-License-Identifier: GPL-2.0-only
#include "dm.h"
#include "persistent-data/dm-transaction-manager.h"
#include "persistent-data/dm-bitset.h"
#include "persistent-data/dm-space-map.h"
#include <linux/dm-io.h>
#include <linux/dm-kcopyd.h>
#include <linux/init.h>
#include <linux/mempool.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#define DM_MSG_PREFIX "era"
#define SUPERBLOCK_LOCATION 0
#define SUPERBLOCK_MAGIC 2126579579
#define SUPERBLOCK_CSUM_XOR 146538381
#define MIN_ERA_VERSION 1
#define MAX_ERA_VERSION 1
#define INVALID_WRITESET_ROOT SUPERBLOCK_LOCATION
#define MIN_BLOCK_SIZE 8
/*
*--------------------------------------------------------------
* Writeset
*--------------------------------------------------------------
*/
struct writeset_metadata {
uint32_t nr_bits;
dm_block_t root;
};
struct writeset {
struct writeset_metadata md;
/*
* An in core copy of the bits to save constantly doing look ups on
* disk.
*/
unsigned long *bits;
};
/*
* This does not free off the on disk bitset as this will normally be done
* after digesting into the era array.
*/
static void writeset_free(struct writeset *ws)
{
vfree(ws->bits);
ws->bits = NULL;
}
static int setup_on_disk_bitset(struct dm_disk_bitset *info,
unsigned int nr_bits, dm_block_t *root)
{
int r;
r = dm_bitset_empty(info, root);
if (r)
return r;
return dm_bitset_resize(info, *root, 0, nr_bits, false, root);
}
static size_t bitset_size(unsigned int nr_bits)
{
return sizeof(unsigned long) * dm_div_up(nr_bits, BITS_PER_LONG);
}
/*
* Allocates memory for the in core bitset.
*/
static int writeset_alloc(struct writeset *ws, dm_block_t nr_blocks)
{
ws->bits = vzalloc(bitset_size(nr_blocks));
if (!ws->bits) {
DMERR("%s: couldn't allocate in memory bitset", __func__);
return -ENOMEM;
}
return 0;
}
/*
* Wipes the in-core bitset, and creates a new on disk bitset.
*/
static int writeset_init(struct dm_disk_bitset *info, struct writeset *ws,
dm_block_t nr_blocks)
{
int r;
memset(ws->bits, 0, bitset_size(nr_blocks));
ws->md.nr_bits = nr_blocks;
r = setup_on_disk_bitset(info, ws->md.nr_bits, &ws->md.root);
if (r) {
DMERR("%s: setup_on_disk_bitset failed", __func__);
return r;
}
return 0;
}
static bool writeset_marked(struct writeset *ws, dm_block_t block)
{
return test_bit(block, ws->bits);
}
static int writeset_marked_on_disk(struct dm_disk_bitset *info,
struct writeset_metadata *m, dm_block_t block,
bool *result)
{
int r;
dm_block_t old = m->root;
/*
* The bitset was flushed when it was archived, so we know there'll
* be no change to the root.
*/
r = dm_bitset_test_bit(info, m->root, block, &m->root, result);
if (r) {
DMERR("%s: dm_bitset_test_bit failed", __func__);
return r;
}
BUG_ON(m->root != old);
return r;
}
/*
* Returns < 0 on error, 0 if the bit wasn't previously set, 1 if it was.
*/
static int writeset_test_and_set(struct dm_disk_bitset *info,
struct writeset *ws, uint32_t block)
{
int r;
if (!test_bit(block, ws->bits)) {
r = dm_bitset_set_bit(info, ws->md.root, block, &ws->md.root);
if (r) {
/* FIXME: fail mode */
return r;
}
return 0;
}
return 1;
}
/*
*--------------------------------------------------------------
* On disk metadata layout
*--------------------------------------------------------------
*/
#define SPACE_MAP_ROOT_SIZE 128
#define UUID_LEN 16
struct writeset_disk {
__le32 nr_bits;
__le64 root;
} __packed;
struct superblock_disk {
__le32 csum;
__le32 flags;
__le64 blocknr;
__u8 uuid[UUID_LEN];
__le64 magic;
__le32 version;
__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
__le32 data_block_size;
__le32 metadata_block_size;
__le32 nr_blocks;
__le32 current_era;
struct writeset_disk current_writeset;
/*
* Only these two fields are valid within the metadata snapshot.
*/
__le64 writeset_tree_root;
__le64 era_array_root;
__le64 metadata_snap;
} __packed;
/*
*--------------------------------------------------------------
* Superblock validation
*--------------------------------------------------------------
*/
static void sb_prepare_for_write(struct dm_block_validator *v,
struct dm_block *b,
size_t sb_block_size)
{
struct superblock_disk *disk = dm_block_data(b);
disk->blocknr = cpu_to_le64(dm_block_location(b));
disk->csum = cpu_to_le32(dm_bm_checksum(&disk->flags,
sb_block_size - sizeof(__le32),
SUPERBLOCK_CSUM_XOR));
}
static int check_metadata_version(struct superblock_disk *disk)
{
uint32_t metadata_version = le32_to_cpu(disk->version);
if (metadata_version < MIN_ERA_VERSION || metadata_version > MAX_ERA_VERSION) {
DMERR("Era metadata version %u found, but only versions between %u and %u supported.",
metadata_version, MIN_ERA_VERSION, MAX_ERA_VERSION);
return -EINVAL;
}
return 0;
}
static int sb_check(struct dm_block_validator *v,
struct dm_block *b,
size_t sb_block_size)
{
struct superblock_disk *disk = dm_block_data(b);
__le32 csum_le;
if (dm_block_location(b) != le64_to_cpu(disk->blocknr)) {
DMERR("%s failed: blocknr %llu: wanted %llu",
__func__, le64_to_cpu(disk->blocknr),
(unsigned long long)dm_block_location(b));
return -ENOTBLK;
}
if (le64_to_cpu(disk->magic) != SUPERBLOCK_MAGIC) {
DMERR("%s failed: magic %llu: wanted %llu",
__func__, le64_to_cpu(disk->magic),
(unsigned long long) SUPERBLOCK_MAGIC);
return -EILSEQ;
}
csum_le = cpu_to_le32(dm_bm_checksum(&disk->flags,
sb_block_size - sizeof(__le32),
SUPERBLOCK_CSUM_XOR));
if (csum_le != disk->csum) {
DMERR("%s failed: csum %u: wanted %u",
__func__, le32_to_cpu(csum_le), le32_to_cpu(disk->csum));
return -EILSEQ;
}
return check_metadata_version(disk);
}
static struct dm_block_validator sb_validator = {
.name = "superblock",
.prepare_for_write = sb_prepare_for_write,
.check = sb_check
};
/*
*--------------------------------------------------------------
* Low level metadata handling
*--------------------------------------------------------------
*/
#define DM_ERA_METADATA_BLOCK_SIZE 4096
#define ERA_MAX_CONCURRENT_LOCKS 5
struct era_metadata {
struct block_device *bdev;
struct dm_block_manager *bm;
struct dm_space_map *sm;
struct dm_transaction_manager *tm;
dm_block_t block_size;
uint32_t nr_blocks;
uint32_t current_era;
/*
* We preallocate 2 writesets. When an era rolls over we
* switch between them. This means the allocation is done at
* preresume time, rather than on the io path.
*/
struct writeset writesets[2];
struct writeset *current_writeset;
dm_block_t writeset_tree_root;
dm_block_t era_array_root;
struct dm_disk_bitset bitset_info;
struct dm_btree_info writeset_tree_info;
struct dm_array_info era_array_info;
dm_block_t metadata_snap;
/*
* A flag that is set whenever a writeset has been archived.
*/
bool archived_writesets;
/*
* Reading the space map root can fail, so we read it into this
* buffer before the superblock is locked and updated.
*/
__u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
};
static int superblock_read_lock(struct era_metadata *md,
struct dm_block **sblock)
{
return dm_bm_read_lock(md->bm, SUPERBLOCK_LOCATION,
&sb_validator, sblock);
}
static int superblock_lock_zero(struct era_metadata *md,
struct dm_block **sblock)
{
return dm_bm_write_lock_zero(md->bm, SUPERBLOCK_LOCATION,
&sb_validator, sblock);
}
static int superblock_lock(struct era_metadata *md,
struct dm_block **sblock)
{
return dm_bm_write_lock(md->bm, SUPERBLOCK_LOCATION,
&sb_validator, sblock);
}
/* FIXME: duplication with cache and thin */
static int superblock_all_zeroes(struct dm_block_manager *bm, bool *result)
{
int r;
unsigned int i;
struct dm_block *b;
__le64 *data_le, zero = cpu_to_le64(0);
unsigned int sb_block_size = dm_bm_block_size(bm) / sizeof(__le64);
/*
* We can't use a validator here - it may be all zeroes.
*/
r = dm_bm_read_lock(bm, SUPERBLOCK_LOCATION, NULL, &b);
if (r)
return r;
data_le = dm_block_data(b);
*result = true;
for (i = 0; i < sb_block_size; i++) {
if (data_le[i] != zero) {
*result = false;
break;
}
}
dm_bm_unlock(b);
return 0;
}
/*----------------------------------------------------------------*/
static void ws_pack(const struct writeset_metadata *core, struct writeset_disk *disk)
{
disk->nr_bits = cpu_to_le32(core->nr_bits);
disk->root = cpu_to_le64(core->root);
}
static void ws_unpack(const struct writeset_disk *disk, struct writeset_metadata *core)
{
core->nr_bits = le32_to_cpu(disk->nr_bits);
core->root = le64_to_cpu(disk->root);
}
static void ws_inc(void *context, const void *value, unsigned int count)
{
struct era_metadata *md = context;
struct writeset_disk ws_d;
dm_block_t b;
unsigned int i;
for (i = 0; i < count; i++) {
memcpy(&ws_d, value + (i * sizeof(ws_d)), sizeof(ws_d));
b = le64_to_cpu(ws_d.root);
dm_tm_inc(md->tm, b);
}
}
static void ws_dec(void *context, const void *value, unsigned int count)
{
struct era_metadata *md = context;
struct writeset_disk ws_d;
dm_block_t b;
unsigned int i;
for (i = 0; i < count; i++) {
memcpy(&ws_d, value + (i * sizeof(ws_d)), sizeof(ws_d));
b = le64_to_cpu(ws_d.root);
dm_bitset_del(&md->bitset_info, b);
}
}
static int ws_eq(void *context, const void *value1, const void *value2)
{
return !memcmp(value1, value2, sizeof(struct writeset_disk));
}
/*----------------------------------------------------------------*/
static void setup_writeset_tree_info(struct era_metadata *md)
{
struct dm_btree_value_type *vt = &md->writeset_tree_info.value_type;
md->writeset_tree_info.tm = md->tm;
md->writeset_tree_info.levels = 1;
vt->context = md;
vt->size = sizeof(struct writeset_disk);
vt->inc = ws_inc;
vt->dec = ws_dec;
vt->equal = ws_eq;
}
static void setup_era_array_info(struct era_metadata *md)
{
struct dm_btree_value_type vt;
vt.context = NULL;
vt.size = sizeof(__le32);
vt.inc = NULL;
vt.dec = NULL;
vt.equal = NULL;
dm_array_info_init(&md->era_array_info, md->tm, &vt);
}
static void setup_infos(struct era_metadata *md)
{
dm_disk_bitset_init(md->tm, &md->bitset_info);
setup_writeset_tree_info(md);
setup_era_array_info(md);
}
/*----------------------------------------------------------------*/
static int create_fresh_metadata(struct era_metadata *md)
{
int r;
r = dm_tm_create_with_sm(md->bm, SUPERBLOCK_LOCATION,
&md->tm, &md->sm);
if (r < 0) {
DMERR("dm_tm_create_with_sm failed");
return r;
}
setup_infos(md);
r = dm_btree_empty(&md->writeset_tree_info, &md->writeset_tree_root);
if (r) {
DMERR("couldn't create new writeset tree");
goto bad;
}
r = dm_array_empty(&md->era_array_info, &md->era_array_root);
if (r) {
DMERR("couldn't create era array");
goto bad;
}
return 0;
bad:
dm_sm_destroy(md->sm);
dm_tm_destroy(md->tm);
return r;
}
static int save_sm_root(struct era_metadata *md)
{
int r;
size_t metadata_len;
r = dm_sm_root_size(md->sm, &metadata_len);
if (r < 0)
return r;
return dm_sm_copy_root(md->sm, &md->metadata_space_map_root,
metadata_len);
}
static void copy_sm_root(struct era_metadata *md, struct superblock_disk *disk)
{
memcpy(&disk->metadata_space_map_root,
&md->metadata_space_map_root,
sizeof(md->metadata_space_map_root));
}
/*
* Writes a superblock, including the static fields that don't get updated
* with every commit (possible optimisation here). 'md' should be fully
* constructed when this is called.
*/
static void prepare_superblock(struct era_metadata *md, struct superblock_disk *disk)
{
disk->magic = cpu_to_le64(SUPERBLOCK_MAGIC);
disk->flags = cpu_to_le32(0ul);
/* FIXME: can't keep blanking the uuid (uuid is currently unused though) */
memset(disk->uuid, 0, sizeof(disk->uuid));
disk->version = cpu_to_le32(MAX_ERA_VERSION);
copy_sm_root(md, disk);
disk->data_block_size = cpu_to_le32(md->block_size);
disk->metadata_block_size = cpu_to_le32(DM_ERA_METADATA_BLOCK_SIZE >> SECTOR_SHIFT);
disk->nr_blocks = cpu_to_le32(md->nr_blocks);
disk->current_era = cpu_to_le32(md->current_era);
ws_pack(&md->current_writeset->md, &disk->current_writeset);
disk->writeset_tree_root = cpu_to_le64(md->writeset_tree_root);
disk->era_array_root = cpu_to_le64(md->era_array_root);
disk->metadata_snap = cpu_to_le64(md->metadata_snap);
}
static int write_superblock(struct era_metadata *md)
{
int r;
struct dm_block *sblock;
struct superblock_disk *disk;
r = save_sm_root(md);
if (r) {
DMERR("%s: save_sm_root failed", __func__);
return r;
}
r = superblock_lock_zero(md, &sblock);
if (r)
return r;
disk = dm_block_data(sblock);
prepare_superblock(md, disk);
return dm_tm_commit(md->tm, sblock);
}
/*
* Assumes block_size and the infos are set.
*/
static int format_metadata(struct era_metadata *md)
{
int r;
r = create_fresh_metadata(md);
if (r)
return r;
r = write_superblock(md);
if (r) {
dm_sm_destroy(md->sm);
dm_tm_destroy(md->tm);
return r;
}
return 0;
}
static int open_metadata(struct era_metadata *md)
{
int r;
struct dm_block *sblock;
struct superblock_disk *disk;
r = superblock_read_lock(md, &sblock);
if (r) {
DMERR("couldn't read_lock superblock");
return r;
}
disk = dm_block_data(sblock);
/* Verify the data block size hasn't changed */
if (le32_to_cpu(disk->data_block_size) != md->block_size) {
DMERR("changing the data block size (from %u to %llu) is not supported",
le32_to_cpu(disk->data_block_size), md->block_size);
r = -EINVAL;
goto bad;
}
r = dm_tm_open_with_sm(md->bm, SUPERBLOCK_LOCATION,
disk->metadata_space_map_root,
sizeof(disk->metadata_space_map_root),
&md->tm, &md->sm);
if (r) {
DMERR("dm_tm_open_with_sm failed");
goto bad;
}
setup_infos(md);
md->nr_blocks = le32_to_cpu(disk->nr_blocks);
md->current_era = le32_to_cpu(disk->current_era);
ws_unpack(&disk->current_writeset, &md->current_writeset->md);
md->writeset_tree_root = le64_to_cpu(disk->writeset_tree_root);
md->era_array_root = le64_to_cpu(disk->era_array_root);
md->metadata_snap = le64_to_cpu(disk->metadata_snap);
md->archived_writesets = true;
dm_bm_unlock(sblock);
return 0;
bad:
dm_bm_unlock(sblock);
return r;
}
static int open_or_format_metadata(struct era_metadata *md,
bool may_format)
{
int r;
bool unformatted = false;
r = superblock_all_zeroes(md->bm, &unformatted);
if (r)
return r;
if (unformatted)
return may_format ? format_metadata(md) : -EPERM;
return open_metadata(md);
}
static int create_persistent_data_objects(struct era_metadata *md,
bool may_format)
{
int r;
md->bm = dm_block_manager_create(md->bdev, DM_ERA_METADATA_BLOCK_SIZE,
ERA_MAX_CONCURRENT_LOCKS);
if (IS_ERR(md->bm)) {
DMERR("could not create block manager");
return PTR_ERR(md->bm);
}
r = open_or_format_metadata(md, may_format);
if (r)
dm_block_manager_destroy(md->bm);
return r;
}
static void destroy_persistent_data_objects(struct era_metadata *md)
{
dm_sm_destroy(md->sm);
dm_tm_destroy(md->tm);
dm_block_manager_destroy(md->bm);
}
/*
* This waits until all era_map threads have picked up the new filter.
*/
static void swap_writeset(struct era_metadata *md, struct writeset *new_writeset)
{
rcu_assign_pointer(md->current_writeset, new_writeset);
synchronize_rcu();
}
/*
*------------------------------------------------------------------------
* Writesets get 'digested' into the main era array.
*
* We're using a coroutine here so the worker thread can do the digestion,
* thus avoiding synchronisation of the metadata. Digesting a whole
* writeset in one go would cause too much latency.
*------------------------------------------------------------------------
*/
struct digest {
uint32_t era;
unsigned int nr_bits, current_bit;
struct writeset_metadata writeset;
__le32 value;
struct dm_disk_bitset info;
int (*step)(struct era_metadata *md, struct digest *d);
};
static int metadata_digest_lookup_writeset(struct era_metadata *md,
struct digest *d);
static int metadata_digest_remove_writeset(struct era_metadata *md,
struct digest *d)
{
int r;
uint64_t key = d->era;
r = dm_btree_remove(&md->writeset_tree_info, md->writeset_tree_root,
&key, &md->writeset_tree_root);
if (r) {
DMERR("%s: dm_btree_remove failed", __func__);
return r;
}
d->step = metadata_digest_lookup_writeset;
return 0;
}
#define INSERTS_PER_STEP 100
static int metadata_digest_transcribe_writeset(struct era_metadata *md,
struct digest *d)
{
int r;
bool marked;
unsigned int b, e = min(d->current_bit + INSERTS_PER_STEP, d->nr_bits);
for (b = d->current_bit; b < e; b++) {
r = writeset_marked_on_disk(&d->info, &d->writeset, b, &marked);
if (r) {
DMERR("%s: writeset_marked_on_disk failed", __func__);
return r;
}
if (!marked)
continue;
__dm_bless_for_disk(&d->value);
r = dm_array_set_value(&md->era_array_info, md->era_array_root,
b, &d->value, &md->era_array_root);
if (r) {
DMERR("%s: dm_array_set_value failed", __func__);
return r;
}
}
if (b == d->nr_bits)
d->step = metadata_digest_remove_writeset;
else
d->current_bit = b;
return 0;
}
static int metadata_digest_lookup_writeset(struct era_metadata *md,
struct digest *d)
{
int r;
uint64_t key;
struct writeset_disk disk;
r = dm_btree_find_lowest_key(&md->writeset_tree_info,
md->writeset_tree_root, &key);
if (r < 0)
return r;
d->era = key;
r = dm_btree_lookup(&md->writeset_tree_info,
md->writeset_tree_root, &key, &disk);
if (r) {
if (r == -ENODATA) {
d->step = NULL;
return 0;
}
DMERR("%s: dm_btree_lookup failed", __func__);
return r;
}
ws_unpack(&disk, &d->writeset);
d->value = cpu_to_le32(key);
/*
* We initialise another bitset info to avoid any caching side effects
* with the previous one.
*/
dm_disk_bitset_init(md->tm, &d->info);
d->nr_bits = min(d->writeset.nr_bits, md->nr_blocks);
d->current_bit = 0;
d->step = metadata_digest_transcribe_writeset;
return 0;
}
static int metadata_digest_start(struct era_metadata *md, struct digest *d)
{
if (d->step)
return 0;
memset(d, 0, sizeof(*d));
d->step = metadata_digest_lookup_writeset;
return 0;
}
/*
*-----------------------------------------------------------------
* High level metadata interface. Target methods should use these,
* and not the lower level ones.
*-----------------------------------------------------------------
*/
static struct era_metadata *metadata_open(struct block_device *bdev,
sector_t block_size,
bool may_format)
{
int r;
struct era_metadata *md = kzalloc(sizeof(*md), GFP_KERNEL);
if (!md)
return NULL;
md->bdev = bdev;
md->block_size = block_size;
md->writesets[0].md.root = INVALID_WRITESET_ROOT;
md->writesets[1].md.root = INVALID_WRITESET_ROOT;
md->current_writeset = &md->writesets[0];
r = create_persistent_data_objects(md, may_format);
if (r) {
kfree(md);
return ERR_PTR(r);
}
return md;
}
static void metadata_close(struct era_metadata *md)
{
writeset_free(&md->writesets[0]);
writeset_free(&md->writesets[1]);
destroy_persistent_data_objects(md);
kfree(md);
}
static bool valid_nr_blocks(dm_block_t n)
{
/*
* dm_bitset restricts us to 2^32. test_bit & co. restrict us
* further to 2^31 - 1
*/
return n < (1ull << 31);
}
static int metadata_resize(struct era_metadata *md, void *arg)
{
int r;
dm_block_t *new_size = arg;
__le32 value;
if (!valid_nr_blocks(*new_size)) {
DMERR("Invalid number of origin blocks %llu",
(unsigned long long) *new_size);
return -EINVAL;
}
writeset_free(&md->writesets[0]);
writeset_free(&md->writesets[1]);
r = writeset_alloc(&md->writesets[0], *new_size);
if (r) {
DMERR("%s: writeset_alloc failed for writeset 0", __func__);
return r;
}
r = writeset_alloc(&md->writesets[1], *new_size);
if (r) {
DMERR("%s: writeset_alloc failed for writeset 1", __func__);
writeset_free(&md->writesets[0]);
return r;
}
value = cpu_to_le32(0u);
__dm_bless_for_disk(&value);
r = dm_array_resize(&md->era_array_info, md->era_array_root,
md->nr_blocks, *new_size,
&value, &md->era_array_root);
if (r) {
DMERR("%s: dm_array_resize failed", __func__);
writeset_free(&md->writesets[0]);
writeset_free(&md->writesets[1]);
return r;
}
md->nr_blocks = *new_size;
return 0;
}
static int metadata_era_archive(struct era_metadata *md)
{
int r;
uint64_t keys[1];
struct writeset_disk value;
r = dm_bitset_flush(&md->bitset_info, md->current_writeset->md.root,
&md->current_writeset->md.root);
if (r) {
DMERR("%s: dm_bitset_flush failed", __func__);
return r;
}
ws_pack(&md->current_writeset->md, &value);
keys[0] = md->current_era;
__dm_bless_for_disk(&value);
r = dm_btree_insert(&md->writeset_tree_info, md->writeset_tree_root,
keys, &value, &md->writeset_tree_root);
if (r) {
DMERR("%s: couldn't insert writeset into btree", __func__);
/* FIXME: fail mode */
return r;
}
md->current_writeset->md.root = INVALID_WRITESET_ROOT;
md->archived_writesets = true;
return 0;
}
static struct writeset *next_writeset(struct era_metadata *md)
{
return (md->current_writeset == &md->writesets[0]) ?
&md->writesets[1] : &md->writesets[0];
}
static int metadata_new_era(struct era_metadata *md)
{
int r;
struct writeset *new_writeset = next_writeset(md);
r = writeset_init(&md->bitset_info, new_writeset, md->nr_blocks);
if (r) {
DMERR("%s: writeset_init failed", __func__);
return r;
}
swap_writeset(md, new_writeset);
md->current_era++;
return 0;
}
static int metadata_era_rollover(struct era_metadata *md)
{
int r;
if (md->current_writeset->md.root != INVALID_WRITESET_ROOT) {
r = metadata_era_archive(md);
if (r) {
DMERR("%s: metadata_archive_era failed", __func__);
/* FIXME: fail mode? */
return r;
}
}
r = metadata_new_era(md);
if (r) {
DMERR("%s: new era failed", __func__);
/* FIXME: fail mode */
return r;
}
return 0;
}
static bool metadata_current_marked(struct era_metadata *md, dm_block_t block)
{
bool r;
struct writeset *ws;
rcu_read_lock();
ws = rcu_dereference(md->current_writeset);
r = writeset_marked(ws, block);
rcu_read_unlock();
return r;
}
static int metadata_commit(struct era_metadata *md)
{
int r;
struct dm_block *sblock;
if (md->current_writeset->md.root != INVALID_WRITESET_ROOT) {
r = dm_bitset_flush(&md->bitset_info, md->current_writeset->md.root,
&md->current_writeset->md.root);
if (r) {
DMERR("%s: bitset flush failed", __func__);
return r;
}
}
r = dm_tm_pre_commit(md->tm);
if (r) {
DMERR("%s: pre commit failed", __func__);
return r;
}
r = save_sm_root(md);
if (r) {
DMERR("%s: save_sm_root failed", __func__);
return r;
}
r = superblock_lock(md, &sblock);
if (r) {
DMERR("%s: superblock lock failed", __func__);
return r;
}
prepare_superblock(md, dm_block_data(sblock));
return dm_tm_commit(md->tm, sblock);
}
static int metadata_checkpoint(struct era_metadata *md)
{
/*
* For now we just rollover, but later I want to put a check in to
* avoid this if the filter is still pretty fresh.
*/
return metadata_era_rollover(md);
}
/*
* Metadata snapshots allow userland to access era data.
*/
static int metadata_take_snap(struct era_metadata *md)
{
int r, inc;
struct dm_block *clone;
if (md->metadata_snap != SUPERBLOCK_LOCATION) {
DMERR("%s: metadata snapshot already exists", __func__);
return -EINVAL;
}
r = metadata_era_rollover(md);
if (r) {
DMERR("%s: era rollover failed", __func__);
return r;
}
r = metadata_commit(md);
if (r) {
DMERR("%s: pre commit failed", __func__);
return r;
}
r = dm_sm_inc_block(md->sm, SUPERBLOCK_LOCATION);
if (r) {
DMERR("%s: couldn't increment superblock", __func__);
return r;
}
r = dm_tm_shadow_block(md->tm, SUPERBLOCK_LOCATION,
&sb_validator, &clone, &inc);
if (r) {
DMERR("%s: couldn't shadow superblock", __func__);
dm_sm_dec_block(md->sm, SUPERBLOCK_LOCATION);
return r;
}
BUG_ON(!inc);
r = dm_sm_inc_block(md->sm, md->writeset_tree_root);
if (r) {
DMERR("%s: couldn't inc writeset tree root", __func__);
dm_tm_unlock(md->tm, clone);
return r;
}
r = dm_sm_inc_block(md->sm, md->era_array_root);
if (r) {
DMERR("%s: couldn't inc era tree root", __func__);
dm_sm_dec_block(md->sm, md->writeset_tree_root);
dm_tm_unlock(md->tm, clone);
return r;
}
md->metadata_snap = dm_block_location(clone);
dm_tm_unlock(md->tm, clone);
return 0;
}
static int metadata_drop_snap(struct era_metadata *md)
{
int r;
dm_block_t location;
struct dm_block *clone;
struct superblock_disk *disk;
if (md->metadata_snap == SUPERBLOCK_LOCATION) {
DMERR("%s: no snap to drop", __func__);
return -EINVAL;
}
r = dm_tm_read_lock(md->tm, md->metadata_snap, &sb_validator, &clone);
if (r) {
DMERR("%s: couldn't read lock superblock clone", __func__);
return r;
}
/*
* Whatever happens now we'll commit with no record of the metadata
* snap.
*/
md->metadata_snap = SUPERBLOCK_LOCATION;
disk = dm_block_data(clone);
r = dm_btree_del(&md->writeset_tree_info,
le64_to_cpu(disk->writeset_tree_root));
if (r) {
DMERR("%s: error deleting writeset tree clone", __func__);
dm_tm_unlock(md->tm, clone);
return r;
}
r = dm_array_del(&md->era_array_info, le64_to_cpu(disk->era_array_root));
if (r) {
DMERR("%s: error deleting era array clone", __func__);
dm_tm_unlock(md->tm, clone);
return r;
}
location = dm_block_location(clone);
dm_tm_unlock(md->tm, clone);
return dm_sm_dec_block(md->sm, location);
}
struct metadata_stats {
dm_block_t used;
dm_block_t total;
dm_block_t snap;
uint32_t era;
};
static int metadata_get_stats(struct era_metadata *md, void *ptr)
{
int r;
struct metadata_stats *s = ptr;
dm_block_t nr_free, nr_total;
r = dm_sm_get_nr_free(md->sm, &nr_free);
if (r) {
DMERR("dm_sm_get_nr_free returned %d", r);
return r;
}
r = dm_sm_get_nr_blocks(md->sm, &nr_total);
if (r) {
DMERR("dm_pool_get_metadata_dev_size returned %d", r);
return r;
}
s->used = nr_total - nr_free;
s->total = nr_total;
s->snap = md->metadata_snap;
s->era = md->current_era;
return 0;
}
/*----------------------------------------------------------------*/
struct era {
struct dm_target *ti;
struct dm_dev *metadata_dev;
struct dm_dev *origin_dev;
dm_block_t nr_blocks;
uint32_t sectors_per_block;
int sectors_per_block_shift;
struct era_metadata *md;
struct workqueue_struct *wq;
struct work_struct worker;
spinlock_t deferred_lock;
struct bio_list deferred_bios;
spinlock_t rpc_lock;
struct list_head rpc_calls;
struct digest digest;
atomic_t suspended;
};
struct rpc {
struct list_head list;
int (*fn0)(struct era_metadata *md);
int (*fn1)(struct era_metadata *md, void *ref);
void *arg;
int result;
struct completion complete;
};
/*
*---------------------------------------------------------------
* Remapping.
*---------------------------------------------------------------
*/
static bool block_size_is_power_of_two(struct era *era)
{
return era->sectors_per_block_shift >= 0;
}
static dm_block_t get_block(struct era *era, struct bio *bio)
{
sector_t block_nr = bio->bi_iter.bi_sector;
if (!block_size_is_power_of_two(era))
(void) sector_div(block_nr, era->sectors_per_block);
else
block_nr >>= era->sectors_per_block_shift;
return block_nr;
}
static void remap_to_origin(struct era *era, struct bio *bio)
{
bio_set_dev(bio, era->origin_dev->bdev);
}
/*
*--------------------------------------------------------------
* Worker thread
*--------------------------------------------------------------
*/
static void wake_worker(struct era *era)
{
if (!atomic_read(&era->suspended))
queue_work(era->wq, &era->worker);
}
static void process_old_eras(struct era *era)
{
int r;
if (!era->digest.step)
return;
r = era->digest.step(era->md, &era->digest);
if (r < 0) {
DMERR("%s: digest step failed, stopping digestion", __func__);
era->digest.step = NULL;
} else if (era->digest.step)
wake_worker(era);
}
static void process_deferred_bios(struct era *era)
{
int r;
struct bio_list deferred_bios, marked_bios;
struct bio *bio;
struct blk_plug plug;
bool commit_needed = false;
bool failed = false;
struct writeset *ws = era->md->current_writeset;
bio_list_init(&deferred_bios);
bio_list_init(&marked_bios);
spin_lock(&era->deferred_lock);
bio_list_merge(&deferred_bios, &era->deferred_bios);
bio_list_init(&era->deferred_bios);
spin_unlock(&era->deferred_lock);
if (bio_list_empty(&deferred_bios))
return;
while ((bio = bio_list_pop(&deferred_bios))) {
r = writeset_test_and_set(&era->md->bitset_info, ws,
get_block(era, bio));
if (r < 0) {
/*
* This is bad news, we need to rollback.
* FIXME: finish.
*/
failed = true;
} else if (r == 0)
commit_needed = true;
bio_list_add(&marked_bios, bio);
}
if (commit_needed) {
r = metadata_commit(era->md);
if (r)
failed = true;
}
if (failed)
while ((bio = bio_list_pop(&marked_bios)))
bio_io_error(bio);
else {
blk_start_plug(&plug);
while ((bio = bio_list_pop(&marked_bios))) {
/*
* Only update the in-core writeset if the on-disk one
* was updated too.
*/
if (commit_needed)
set_bit(get_block(era, bio), ws->bits);
submit_bio_noacct(bio);
}
blk_finish_plug(&plug);
}
}
static void process_rpc_calls(struct era *era)
{
int r;
bool need_commit = false;
struct list_head calls;
struct rpc *rpc, *tmp;
INIT_LIST_HEAD(&calls);
spin_lock(&era->rpc_lock);
list_splice_init(&era->rpc_calls, &calls);
spin_unlock(&era->rpc_lock);
list_for_each_entry_safe(rpc, tmp, &calls, list) {
rpc->result = rpc->fn0 ? rpc->fn0(era->md) : rpc->fn1(era->md, rpc->arg);
need_commit = true;
}
if (need_commit) {
r = metadata_commit(era->md);
if (r)
list_for_each_entry_safe(rpc, tmp, &calls, list)
rpc->result = r;
}
list_for_each_entry_safe(rpc, tmp, &calls, list)
complete(&rpc->complete);
}
static void kick_off_digest(struct era *era)
{
if (era->md->archived_writesets) {
era->md->archived_writesets = false;
metadata_digest_start(era->md, &era->digest);
}
}
static void do_work(struct work_struct *ws)
{
struct era *era = container_of(ws, struct era, worker);
kick_off_digest(era);
process_old_eras(era);
process_deferred_bios(era);
process_rpc_calls(era);
}
static void defer_bio(struct era *era, struct bio *bio)
{
spin_lock(&era->deferred_lock);
bio_list_add(&era->deferred_bios, bio);
spin_unlock(&era->deferred_lock);
wake_worker(era);
}
/*
* Make an rpc call to the worker to change the metadata.
*/
static int perform_rpc(struct era *era, struct rpc *rpc)
{
rpc->result = 0;
init_completion(&rpc->complete);
spin_lock(&era->rpc_lock);
list_add(&rpc->list, &era->rpc_calls);
spin_unlock(&era->rpc_lock);
wake_worker(era);
wait_for_completion(&rpc->complete);
return rpc->result;
}
static int in_worker0(struct era *era, int (*fn)(struct era_metadata *md))
{
struct rpc rpc;
rpc.fn0 = fn;
rpc.fn1 = NULL;
return perform_rpc(era, &rpc);
}
static int in_worker1(struct era *era,
int (*fn)(struct era_metadata *md, void *ref), void *arg)
{
struct rpc rpc;
rpc.fn0 = NULL;
rpc.fn1 = fn;
rpc.arg = arg;
return perform_rpc(era, &rpc);
}
static void start_worker(struct era *era)
{
atomic_set(&era->suspended, 0);
}
static void stop_worker(struct era *era)
{
atomic_set(&era->suspended, 1);
drain_workqueue(era->wq);
}
/*
*--------------------------------------------------------------
* Target methods
*--------------------------------------------------------------
*/
static void era_destroy(struct era *era)
{
if (era->md)
metadata_close(era->md);
if (era->wq)
destroy_workqueue(era->wq);
if (era->origin_dev)
dm_put_device(era->ti, era->origin_dev);
if (era->metadata_dev)
dm_put_device(era->ti, era->metadata_dev);
kfree(era);
}
static dm_block_t calc_nr_blocks(struct era *era)
{
return dm_sector_div_up(era->ti->len, era->sectors_per_block);
}
static bool valid_block_size(dm_block_t block_size)
{
bool greater_than_zero = block_size > 0;
bool multiple_of_min_block_size = (block_size & (MIN_BLOCK_SIZE - 1)) == 0;
return greater_than_zero && multiple_of_min_block_size;
}
/*
* <metadata dev> <data dev> <data block size (sectors)>
*/
static int era_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
int r;
char dummy;
struct era *era;
struct era_metadata *md;
if (argc != 3) {
ti->error = "Invalid argument count";
return -EINVAL;
}
era = kzalloc(sizeof(*era), GFP_KERNEL);
if (!era) {
ti->error = "Error allocating era structure";
return -ENOMEM;
}
era->ti = ti;
r = dm_get_device(ti, argv[0], BLK_OPEN_READ | BLK_OPEN_WRITE,
&era->metadata_dev);
if (r) {
ti->error = "Error opening metadata device";
era_destroy(era);
return -EINVAL;
}
r = dm_get_device(ti, argv[1], BLK_OPEN_READ | BLK_OPEN_WRITE,
&era->origin_dev);
if (r) {
ti->error = "Error opening data device";
era_destroy(era);
return -EINVAL;
}
r = sscanf(argv[2], "%u%c", &era->sectors_per_block, &dummy);
if (r != 1) {
ti->error = "Error parsing block size";
era_destroy(era);
return -EINVAL;
}
r = dm_set_target_max_io_len(ti, era->sectors_per_block);
if (r) {
ti->error = "could not set max io len";
era_destroy(era);
return -EINVAL;
}
if (!valid_block_size(era->sectors_per_block)) {
ti->error = "Invalid block size";
era_destroy(era);
return -EINVAL;
}
if (era->sectors_per_block & (era->sectors_per_block - 1))
era->sectors_per_block_shift = -1;
else
era->sectors_per_block_shift = __ffs(era->sectors_per_block);
md = metadata_open(era->metadata_dev->bdev, era->sectors_per_block, true);
if (IS_ERR(md)) {
ti->error = "Error reading metadata";
era_destroy(era);
return PTR_ERR(md);
}
era->md = md;
era->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM);
if (!era->wq) {
ti->error = "could not create workqueue for metadata object";
era_destroy(era);
return -ENOMEM;
}
INIT_WORK(&era->worker, do_work);
spin_lock_init(&era->deferred_lock);
bio_list_init(&era->deferred_bios);
spin_lock_init(&era->rpc_lock);
INIT_LIST_HEAD(&era->rpc_calls);
ti->private = era;
ti->num_flush_bios = 1;
ti->flush_supported = true;
ti->num_discard_bios = 1;
return 0;
}
static void era_dtr(struct dm_target *ti)
{
era_destroy(ti->private);
}
static int era_map(struct dm_target *ti, struct bio *bio)
{
struct era *era = ti->private;
dm_block_t block = get_block(era, bio);
/*
* All bios get remapped to the origin device. We do this now, but
* it may not get issued until later. Depending on whether the
* block is marked in this era.
*/
remap_to_origin(era, bio);
/*
* REQ_PREFLUSH bios carry no data, so we're not interested in them.
*/
if (!(bio->bi_opf & REQ_PREFLUSH) &&
(bio_data_dir(bio) == WRITE) &&
!metadata_current_marked(era->md, block)) {
defer_bio(era, bio);
return DM_MAPIO_SUBMITTED;
}
return DM_MAPIO_REMAPPED;
}
static void era_postsuspend(struct dm_target *ti)
{
int r;
struct era *era = ti->private;
r = in_worker0(era, metadata_era_archive);
if (r) {
DMERR("%s: couldn't archive current era", __func__);
/* FIXME: fail mode */
}
stop_worker(era);
r = metadata_commit(era->md);
if (r) {
DMERR("%s: metadata_commit failed", __func__);
/* FIXME: fail mode */
}
}
static int era_preresume(struct dm_target *ti)
{
int r;
struct era *era = ti->private;
dm_block_t new_size = calc_nr_blocks(era);
if (era->nr_blocks != new_size) {
r = metadata_resize(era->md, &new_size);
if (r) {
DMERR("%s: metadata_resize failed", __func__);
return r;
}
r = metadata_commit(era->md);
if (r) {
DMERR("%s: metadata_commit failed", __func__);
return r;
}
era->nr_blocks = new_size;
}
start_worker(era);
r = in_worker0(era, metadata_era_rollover);
if (r) {
DMERR("%s: metadata_era_rollover failed", __func__);
return r;
}
return 0;
}
/*
* Status format:
*
* <metadata block size> <#used metadata blocks>/<#total metadata blocks>
* <current era> <held metadata root | '-'>
*/
static void era_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
int r;
struct era *era = ti->private;
ssize_t sz = 0;
struct metadata_stats stats;
char buf[BDEVNAME_SIZE];
switch (type) {
case STATUSTYPE_INFO:
r = in_worker1(era, metadata_get_stats, &stats);
if (r)
goto err;
DMEMIT("%u %llu/%llu %u",
(unsigned int) (DM_ERA_METADATA_BLOCK_SIZE >> SECTOR_SHIFT),
(unsigned long long) stats.used,
(unsigned long long) stats.total,
(unsigned int) stats.era);
if (stats.snap != SUPERBLOCK_LOCATION)
DMEMIT(" %llu", stats.snap);
else
DMEMIT(" -");
break;
case STATUSTYPE_TABLE:
format_dev_t(buf, era->metadata_dev->bdev->bd_dev);
DMEMIT("%s ", buf);
format_dev_t(buf, era->origin_dev->bdev->bd_dev);
DMEMIT("%s %u", buf, era->sectors_per_block);
break;
case STATUSTYPE_IMA:
*result = '\0';
break;
}
return;
err:
DMEMIT("Error");
}
static int era_message(struct dm_target *ti, unsigned int argc, char **argv,
char *result, unsigned int maxlen)
{
struct era *era = ti->private;
if (argc != 1) {
DMERR("incorrect number of message arguments");
return -EINVAL;
}
if (!strcasecmp(argv[0], "checkpoint"))
return in_worker0(era, metadata_checkpoint);
if (!strcasecmp(argv[0], "take_metadata_snap"))
return in_worker0(era, metadata_take_snap);
if (!strcasecmp(argv[0], "drop_metadata_snap"))
return in_worker0(era, metadata_drop_snap);
DMERR("unsupported message '%s'", argv[0]);
return -EINVAL;
}
static sector_t get_dev_size(struct dm_dev *dev)
{
return bdev_nr_sectors(dev->bdev);
}
static int era_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct era *era = ti->private;
return fn(ti, era->origin_dev, 0, get_dev_size(era->origin_dev), data);
}
static void era_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
struct era *era = ti->private;
uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT;
/*
* If the system-determined stacked limits are compatible with the
* era device's blocksize (io_opt is a factor) do not override them.
*/
if (io_opt_sectors < era->sectors_per_block ||
do_div(io_opt_sectors, era->sectors_per_block)) {
blk_limits_io_min(limits, 0);
blk_limits_io_opt(limits, era->sectors_per_block << SECTOR_SHIFT);
}
}
/*----------------------------------------------------------------*/
static struct target_type era_target = {
.name = "era",
.version = {1, 0, 0},
.module = THIS_MODULE,
.ctr = era_ctr,
.dtr = era_dtr,
.map = era_map,
.postsuspend = era_postsuspend,
.preresume = era_preresume,
.status = era_status,
.message = era_message,
.iterate_devices = era_iterate_devices,
.io_hints = era_io_hints
};
module_dm(era);
MODULE_DESCRIPTION(DM_NAME " era target");
MODULE_AUTHOR("Joe Thornber <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-era-target.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2022 Red Hat, Inc.
*/
#include <linux/bio.h>
#include <linux/blk-crypto.h>
#include <linux/blk-integrity.h>
#include "dm-core.h"
static inline bool dm_bvec_iter_rewind(const struct bio_vec *bv,
struct bvec_iter *iter,
unsigned int bytes)
{
int idx;
iter->bi_size += bytes;
if (bytes <= iter->bi_bvec_done) {
iter->bi_bvec_done -= bytes;
return true;
}
bytes -= iter->bi_bvec_done;
idx = iter->bi_idx - 1;
while (idx >= 0 && bytes && bytes > bv[idx].bv_len) {
bytes -= bv[idx].bv_len;
idx--;
}
if (WARN_ONCE(idx < 0 && bytes,
"Attempted to rewind iter beyond bvec's boundaries\n")) {
iter->bi_size -= bytes;
iter->bi_bvec_done = 0;
iter->bi_idx = 0;
return false;
}
iter->bi_idx = idx;
iter->bi_bvec_done = bv[idx].bv_len - bytes;
return true;
}
#if defined(CONFIG_BLK_DEV_INTEGRITY)
/**
* dm_bio_integrity_rewind - Rewind integrity vector
* @bio: bio whose integrity vector to update
* @bytes_done: number of data bytes to rewind
*
* Description: This function calculates how many integrity bytes the
* number of completed data bytes correspond to and rewind the
* integrity vector accordingly.
*/
static void dm_bio_integrity_rewind(struct bio *bio, unsigned int bytes_done)
{
struct bio_integrity_payload *bip = bio_integrity(bio);
struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
unsigned int bytes = bio_integrity_bytes(bi, bytes_done >> 9);
bip->bip_iter.bi_sector -= bio_integrity_intervals(bi, bytes_done >> 9);
dm_bvec_iter_rewind(bip->bip_vec, &bip->bip_iter, bytes);
}
#else /* CONFIG_BLK_DEV_INTEGRITY */
static inline void dm_bio_integrity_rewind(struct bio *bio,
unsigned int bytes_done)
{
}
#endif
#if defined(CONFIG_BLK_INLINE_ENCRYPTION)
/* Decrements @dun by @dec, treating @dun as a multi-limb integer. */
static void dm_bio_crypt_dun_decrement(u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
unsigned int dec)
{
int i;
for (i = 0; dec && i < BLK_CRYPTO_DUN_ARRAY_SIZE; i++) {
u64 prev = dun[i];
dun[i] -= dec;
if (dun[i] > prev)
dec = 1;
else
dec = 0;
}
}
static void dm_bio_crypt_rewind(struct bio *bio, unsigned int bytes)
{
struct bio_crypt_ctx *bc = bio->bi_crypt_context;
dm_bio_crypt_dun_decrement(bc->bc_dun,
bytes >> bc->bc_key->data_unit_size_bits);
}
#else /* CONFIG_BLK_INLINE_ENCRYPTION */
static inline void dm_bio_crypt_rewind(struct bio *bio, unsigned int bytes)
{
}
#endif
static inline void dm_bio_rewind_iter(const struct bio *bio,
struct bvec_iter *iter, unsigned int bytes)
{
iter->bi_sector -= bytes >> 9;
/* No advance means no rewind */
if (bio_no_advance_iter(bio))
iter->bi_size += bytes;
else
dm_bvec_iter_rewind(bio->bi_io_vec, iter, bytes);
}
/**
* dm_bio_rewind - update ->bi_iter of @bio by rewinding @bytes.
* @bio: bio to rewind
* @bytes: how many bytes to rewind
*
* WARNING:
* Caller must ensure that @bio has a fixed end sector, to allow
* rewinding from end of bio and restoring its original position.
* Caller is also responsibile for restoring bio's size.
*/
static void dm_bio_rewind(struct bio *bio, unsigned int bytes)
{
if (bio_integrity(bio))
dm_bio_integrity_rewind(bio, bytes);
if (bio_has_crypt_ctx(bio))
dm_bio_crypt_rewind(bio, bytes);
dm_bio_rewind_iter(bio, &bio->bi_iter, bytes);
}
void dm_io_rewind(struct dm_io *io, struct bio_set *bs)
{
struct bio *orig = io->orig_bio;
struct bio *new_orig = bio_alloc_clone(orig->bi_bdev, orig,
GFP_NOIO, bs);
/*
* dm_bio_rewind can restore to previous position since the
* end sector is fixed for original bio, but we still need
* to restore bio's size manually (using io->sectors).
*/
dm_bio_rewind(new_orig, ((io->sector_offset << 9) -
orig->bi_iter.bi_size));
bio_trim(new_orig, 0, io->sectors);
bio_chain(new_orig, orig);
/*
* __bi_remaining was increased (by dm_split_and_process_bio),
* so must drop the one added in bio_chain.
*/
atomic_dec(&orig->__bi_remaining);
io->orig_bio = new_orig;
}
| linux-master | drivers/md/dm-io-rewind.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2003 Jana Saout <[email protected]>
*
* This file is released under the GPL.
*/
#include <linux/device-mapper.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/bio.h>
#define DM_MSG_PREFIX "zero"
/*
* Construct a dummy mapping that only returns zeros
*/
static int zero_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
if (argc != 0) {
ti->error = "No arguments required";
return -EINVAL;
}
/*
* Silently drop discards, avoiding -EOPNOTSUPP.
*/
ti->num_discard_bios = 1;
ti->discards_supported = true;
return 0;
}
/*
* Return zeros only on reads
*/
static int zero_map(struct dm_target *ti, struct bio *bio)
{
switch (bio_op(bio)) {
case REQ_OP_READ:
if (bio->bi_opf & REQ_RAHEAD) {
/* readahead of null bytes only wastes buffer cache */
return DM_MAPIO_KILL;
}
zero_fill_bio(bio);
break;
case REQ_OP_WRITE:
case REQ_OP_DISCARD:
/* writes get silently dropped */
break;
default:
return DM_MAPIO_KILL;
}
bio_endio(bio);
/* accepted bio, don't make new request */
return DM_MAPIO_SUBMITTED;
}
static void zero_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
limits->max_discard_sectors = UINT_MAX;
limits->max_hw_discard_sectors = UINT_MAX;
limits->discard_granularity = 512;
}
static struct target_type zero_target = {
.name = "zero",
.version = {1, 2, 0},
.features = DM_TARGET_NOWAIT,
.module = THIS_MODULE,
.ctr = zero_ctr,
.map = zero_map,
.io_hints = zero_io_hints,
};
module_dm(zero);
MODULE_AUTHOR("Jana Saout <[email protected]>");
MODULE_DESCRIPTION(DM_NAME " dummy target returning zeros");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-zero.c |
// SPDX-License-Identifier: GPL-2.0-or-later
/*
md.c : Multiple Devices driver for Linux
Copyright (C) 1998, 1999, 2000 Ingo Molnar
completely rewritten, based on the MD driver code from Marc Zyngier
Changes:
- RAID-1/RAID-5 extensions by Miguel de Icaza, Gadi Oxman, Ingo Molnar
- RAID-6 extensions by H. Peter Anvin <[email protected]>
- boot support for linear and striped mode by Harald Hoyer <[email protected]>
- kerneld support by Boris Tobotras <[email protected]>
- kmod support by: Cyrus Durgin
- RAID0 bugfixes: Mark Anthony Lisher <[email protected]>
- Devfs support by Richard Gooch <[email protected]>
- lots of fixes and improvements to the RAID1/RAID5 and generic
RAID code (such as request based resynchronization):
Neil Brown <[email protected]>.
- persistent bitmap code
Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.
Errors, Warnings, etc.
Please use:
pr_crit() for error conditions that risk data loss
pr_err() for error conditions that are unexpected, like an IO error
or internal inconsistency
pr_warn() for error conditions that could have been predicated, like
adding a device to an array when it has incompatible metadata
pr_info() for every interesting, very rare events, like an array starting
or stopping, or resync starting or stopping
pr_debug() for everything else.
*/
#include <linux/sched/mm.h>
#include <linux/sched/signal.h>
#include <linux/kthread.h>
#include <linux/blkdev.h>
#include <linux/blk-integrity.h>
#include <linux/badblocks.h>
#include <linux/sysctl.h>
#include <linux/seq_file.h>
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/ctype.h>
#include <linux/string.h>
#include <linux/hdreg.h>
#include <linux/proc_fs.h>
#include <linux/random.h>
#include <linux/major.h>
#include <linux/module.h>
#include <linux/reboot.h>
#include <linux/file.h>
#include <linux/compat.h>
#include <linux/delay.h>
#include <linux/raid/md_p.h>
#include <linux/raid/md_u.h>
#include <linux/raid/detect.h>
#include <linux/slab.h>
#include <linux/percpu-refcount.h>
#include <linux/part_stat.h>
#include <trace/events/block.h>
#include "md.h"
#include "md-bitmap.h"
#include "md-cluster.h"
/* pers_list is a list of registered personalities protected by pers_lock. */
static LIST_HEAD(pers_list);
static DEFINE_SPINLOCK(pers_lock);
static const struct kobj_type md_ktype;
struct md_cluster_operations *md_cluster_ops;
EXPORT_SYMBOL(md_cluster_ops);
static struct module *md_cluster_mod;
static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
static struct workqueue_struct *md_wq;
static struct workqueue_struct *md_misc_wq;
struct workqueue_struct *md_bitmap_wq;
static int remove_and_add_spares(struct mddev *mddev,
struct md_rdev *this);
static void mddev_detach(struct mddev *mddev);
static void export_rdev(struct md_rdev *rdev, struct mddev *mddev);
static void md_wakeup_thread_directly(struct md_thread __rcu *thread);
/*
* Default number of read corrections we'll attempt on an rdev
* before ejecting it from the array. We divide the read error
* count by 2 for every hour elapsed between read errors.
*/
#define MD_DEFAULT_MAX_CORRECTED_READ_ERRORS 20
/* Default safemode delay: 200 msec */
#define DEFAULT_SAFEMODE_DELAY ((200 * HZ)/1000 +1)
/*
* Current RAID-1,4,5 parallel reconstruction 'guaranteed speed limit'
* is 1000 KB/sec, so the extra system load does not show up that much.
* Increase it if you want to have more _guaranteed_ speed. Note that
* the RAID driver will use the maximum available bandwidth if the IO
* subsystem is idle. There is also an 'absolute maximum' reconstruction
* speed limit - in case reconstruction slows down your system despite
* idle IO detection.
*
* you can change it via /proc/sys/dev/raid/speed_limit_min and _max.
* or /sys/block/mdX/md/sync_speed_{min,max}
*/
static int sysctl_speed_limit_min = 1000;
static int sysctl_speed_limit_max = 200000;
static inline int speed_min(struct mddev *mddev)
{
return mddev->sync_speed_min ?
mddev->sync_speed_min : sysctl_speed_limit_min;
}
static inline int speed_max(struct mddev *mddev)
{
return mddev->sync_speed_max ?
mddev->sync_speed_max : sysctl_speed_limit_max;
}
static void rdev_uninit_serial(struct md_rdev *rdev)
{
if (!test_and_clear_bit(CollisionCheck, &rdev->flags))
return;
kvfree(rdev->serial);
rdev->serial = NULL;
}
static void rdevs_uninit_serial(struct mddev *mddev)
{
struct md_rdev *rdev;
rdev_for_each(rdev, mddev)
rdev_uninit_serial(rdev);
}
static int rdev_init_serial(struct md_rdev *rdev)
{
/* serial_nums equals with BARRIER_BUCKETS_NR */
int i, serial_nums = 1 << ((PAGE_SHIFT - ilog2(sizeof(atomic_t))));
struct serial_in_rdev *serial = NULL;
if (test_bit(CollisionCheck, &rdev->flags))
return 0;
serial = kvmalloc(sizeof(struct serial_in_rdev) * serial_nums,
GFP_KERNEL);
if (!serial)
return -ENOMEM;
for (i = 0; i < serial_nums; i++) {
struct serial_in_rdev *serial_tmp = &serial[i];
spin_lock_init(&serial_tmp->serial_lock);
serial_tmp->serial_rb = RB_ROOT_CACHED;
init_waitqueue_head(&serial_tmp->serial_io_wait);
}
rdev->serial = serial;
set_bit(CollisionCheck, &rdev->flags);
return 0;
}
static int rdevs_init_serial(struct mddev *mddev)
{
struct md_rdev *rdev;
int ret = 0;
rdev_for_each(rdev, mddev) {
ret = rdev_init_serial(rdev);
if (ret)
break;
}
/* Free all resources if pool is not existed */
if (ret && !mddev->serial_info_pool)
rdevs_uninit_serial(mddev);
return ret;
}
/*
* rdev needs to enable serial stuffs if it meets the conditions:
* 1. it is multi-queue device flaged with writemostly.
* 2. the write-behind mode is enabled.
*/
static int rdev_need_serial(struct md_rdev *rdev)
{
return (rdev && rdev->mddev->bitmap_info.max_write_behind > 0 &&
rdev->bdev->bd_disk->queue->nr_hw_queues != 1 &&
test_bit(WriteMostly, &rdev->flags));
}
/*
* Init resource for rdev(s), then create serial_info_pool if:
* 1. rdev is the first device which return true from rdev_enable_serial.
* 2. rdev is NULL, means we want to enable serialization for all rdevs.
*/
void mddev_create_serial_pool(struct mddev *mddev, struct md_rdev *rdev,
bool is_suspend)
{
int ret = 0;
if (rdev && !rdev_need_serial(rdev) &&
!test_bit(CollisionCheck, &rdev->flags))
return;
if (!is_suspend)
mddev_suspend(mddev);
if (!rdev)
ret = rdevs_init_serial(mddev);
else
ret = rdev_init_serial(rdev);
if (ret)
goto abort;
if (mddev->serial_info_pool == NULL) {
/*
* already in memalloc noio context by
* mddev_suspend()
*/
mddev->serial_info_pool =
mempool_create_kmalloc_pool(NR_SERIAL_INFOS,
sizeof(struct serial_info));
if (!mddev->serial_info_pool) {
rdevs_uninit_serial(mddev);
pr_err("can't alloc memory pool for serialization\n");
}
}
abort:
if (!is_suspend)
mddev_resume(mddev);
}
/*
* Free resource from rdev(s), and destroy serial_info_pool under conditions:
* 1. rdev is the last device flaged with CollisionCheck.
* 2. when bitmap is destroyed while policy is not enabled.
* 3. for disable policy, the pool is destroyed only when no rdev needs it.
*/
void mddev_destroy_serial_pool(struct mddev *mddev, struct md_rdev *rdev,
bool is_suspend)
{
if (rdev && !test_bit(CollisionCheck, &rdev->flags))
return;
if (mddev->serial_info_pool) {
struct md_rdev *temp;
int num = 0; /* used to track if other rdevs need the pool */
if (!is_suspend)
mddev_suspend(mddev);
rdev_for_each(temp, mddev) {
if (!rdev) {
if (!mddev->serialize_policy ||
!rdev_need_serial(temp))
rdev_uninit_serial(temp);
else
num++;
} else if (temp != rdev &&
test_bit(CollisionCheck, &temp->flags))
num++;
}
if (rdev)
rdev_uninit_serial(rdev);
if (num)
pr_info("The mempool could be used by other devices\n");
else {
mempool_destroy(mddev->serial_info_pool);
mddev->serial_info_pool = NULL;
}
if (!is_suspend)
mddev_resume(mddev);
}
}
static struct ctl_table_header *raid_table_header;
static struct ctl_table raid_table[] = {
{
.procname = "speed_limit_min",
.data = &sysctl_speed_limit_min,
.maxlen = sizeof(int),
.mode = S_IRUGO|S_IWUSR,
.proc_handler = proc_dointvec,
},
{
.procname = "speed_limit_max",
.data = &sysctl_speed_limit_max,
.maxlen = sizeof(int),
.mode = S_IRUGO|S_IWUSR,
.proc_handler = proc_dointvec,
},
{ }
};
static int start_readonly;
/*
* The original mechanism for creating an md device is to create
* a device node in /dev and to open it. This causes races with device-close.
* The preferred method is to write to the "new_array" module parameter.
* This can avoid races.
* Setting create_on_open to false disables the original mechanism
* so all the races disappear.
*/
static bool create_on_open = true;
/*
* We have a system wide 'event count' that is incremented
* on any 'interesting' event, and readers of /proc/mdstat
* can use 'poll' or 'select' to find out when the event
* count increases.
*
* Events are:
* start array, stop array, error, add device, remove device,
* start build, activate spare
*/
static DECLARE_WAIT_QUEUE_HEAD(md_event_waiters);
static atomic_t md_event_count;
void md_new_event(void)
{
atomic_inc(&md_event_count);
wake_up(&md_event_waiters);
}
EXPORT_SYMBOL_GPL(md_new_event);
/*
* Enables to iterate over all existing md arrays
* all_mddevs_lock protects this list.
*/
static LIST_HEAD(all_mddevs);
static DEFINE_SPINLOCK(all_mddevs_lock);
/* Rather than calling directly into the personality make_request function,
* IO requests come here first so that we can check if the device is
* being suspended pending a reconfiguration.
* We hold a refcount over the call to ->make_request. By the time that
* call has finished, the bio has been linked into some internal structure
* and so is visible to ->quiesce(), so we don't need the refcount any more.
*/
static bool is_suspended(struct mddev *mddev, struct bio *bio)
{
if (is_md_suspended(mddev))
return true;
if (bio_data_dir(bio) != WRITE)
return false;
if (mddev->suspend_lo >= mddev->suspend_hi)
return false;
if (bio->bi_iter.bi_sector >= mddev->suspend_hi)
return false;
if (bio_end_sector(bio) < mddev->suspend_lo)
return false;
return true;
}
void md_handle_request(struct mddev *mddev, struct bio *bio)
{
check_suspended:
if (is_suspended(mddev, bio)) {
DEFINE_WAIT(__wait);
/* Bail out if REQ_NOWAIT is set for the bio */
if (bio->bi_opf & REQ_NOWAIT) {
bio_wouldblock_error(bio);
return;
}
for (;;) {
prepare_to_wait(&mddev->sb_wait, &__wait,
TASK_UNINTERRUPTIBLE);
if (!is_suspended(mddev, bio))
break;
schedule();
}
finish_wait(&mddev->sb_wait, &__wait);
}
if (!percpu_ref_tryget_live(&mddev->active_io))
goto check_suspended;
if (!mddev->pers->make_request(mddev, bio)) {
percpu_ref_put(&mddev->active_io);
goto check_suspended;
}
percpu_ref_put(&mddev->active_io);
}
EXPORT_SYMBOL(md_handle_request);
static void md_submit_bio(struct bio *bio)
{
const int rw = bio_data_dir(bio);
struct mddev *mddev = bio->bi_bdev->bd_disk->private_data;
if (mddev == NULL || mddev->pers == NULL) {
bio_io_error(bio);
return;
}
if (unlikely(test_bit(MD_BROKEN, &mddev->flags)) && (rw == WRITE)) {
bio_io_error(bio);
return;
}
bio = bio_split_to_limits(bio);
if (!bio)
return;
if (mddev->ro == MD_RDONLY && unlikely(rw == WRITE)) {
if (bio_sectors(bio) != 0)
bio->bi_status = BLK_STS_IOERR;
bio_endio(bio);
return;
}
/* bio could be mergeable after passing to underlayer */
bio->bi_opf &= ~REQ_NOMERGE;
md_handle_request(mddev, bio);
}
/* mddev_suspend makes sure no new requests are submitted
* to the device, and that any requests that have been submitted
* are completely handled.
* Once mddev_detach() is called and completes, the module will be
* completely unused.
*/
void mddev_suspend(struct mddev *mddev)
{
struct md_thread *thread = rcu_dereference_protected(mddev->thread,
lockdep_is_held(&mddev->reconfig_mutex));
WARN_ON_ONCE(thread && current == thread->tsk);
if (mddev->suspended++)
return;
wake_up(&mddev->sb_wait);
set_bit(MD_ALLOW_SB_UPDATE, &mddev->flags);
percpu_ref_kill(&mddev->active_io);
if (mddev->pers->prepare_suspend)
mddev->pers->prepare_suspend(mddev);
wait_event(mddev->sb_wait, percpu_ref_is_zero(&mddev->active_io));
clear_bit_unlock(MD_ALLOW_SB_UPDATE, &mddev->flags);
wait_event(mddev->sb_wait, !test_bit(MD_UPDATING_SB, &mddev->flags));
del_timer_sync(&mddev->safemode_timer);
/* restrict memory reclaim I/O during raid array is suspend */
mddev->noio_flag = memalloc_noio_save();
}
EXPORT_SYMBOL_GPL(mddev_suspend);
void mddev_resume(struct mddev *mddev)
{
lockdep_assert_held(&mddev->reconfig_mutex);
if (--mddev->suspended)
return;
/* entred the memalloc scope from mddev_suspend() */
memalloc_noio_restore(mddev->noio_flag);
percpu_ref_resurrect(&mddev->active_io);
wake_up(&mddev->sb_wait);
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
}
EXPORT_SYMBOL_GPL(mddev_resume);
/*
* Generic flush handling for md
*/
static void md_end_flush(struct bio *bio)
{
struct md_rdev *rdev = bio->bi_private;
struct mddev *mddev = rdev->mddev;
bio_put(bio);
rdev_dec_pending(rdev, mddev);
if (atomic_dec_and_test(&mddev->flush_pending)) {
/* The pre-request flush has finished */
queue_work(md_wq, &mddev->flush_work);
}
}
static void md_submit_flush_data(struct work_struct *ws);
static void submit_flushes(struct work_struct *ws)
{
struct mddev *mddev = container_of(ws, struct mddev, flush_work);
struct md_rdev *rdev;
mddev->start_flush = ktime_get_boottime();
INIT_WORK(&mddev->flush_work, md_submit_flush_data);
atomic_set(&mddev->flush_pending, 1);
rcu_read_lock();
rdev_for_each_rcu(rdev, mddev)
if (rdev->raid_disk >= 0 &&
!test_bit(Faulty, &rdev->flags)) {
/* Take two references, one is dropped
* when request finishes, one after
* we reclaim rcu_read_lock
*/
struct bio *bi;
atomic_inc(&rdev->nr_pending);
atomic_inc(&rdev->nr_pending);
rcu_read_unlock();
bi = bio_alloc_bioset(rdev->bdev, 0,
REQ_OP_WRITE | REQ_PREFLUSH,
GFP_NOIO, &mddev->bio_set);
bi->bi_end_io = md_end_flush;
bi->bi_private = rdev;
atomic_inc(&mddev->flush_pending);
submit_bio(bi);
rcu_read_lock();
rdev_dec_pending(rdev, mddev);
}
rcu_read_unlock();
if (atomic_dec_and_test(&mddev->flush_pending))
queue_work(md_wq, &mddev->flush_work);
}
static void md_submit_flush_data(struct work_struct *ws)
{
struct mddev *mddev = container_of(ws, struct mddev, flush_work);
struct bio *bio = mddev->flush_bio;
/*
* must reset flush_bio before calling into md_handle_request to avoid a
* deadlock, because other bios passed md_handle_request suspend check
* could wait for this and below md_handle_request could wait for those
* bios because of suspend check
*/
spin_lock_irq(&mddev->lock);
mddev->prev_flush_start = mddev->start_flush;
mddev->flush_bio = NULL;
spin_unlock_irq(&mddev->lock);
wake_up(&mddev->sb_wait);
if (bio->bi_iter.bi_size == 0) {
/* an empty barrier - all done */
bio_endio(bio);
} else {
bio->bi_opf &= ~REQ_PREFLUSH;
md_handle_request(mddev, bio);
}
}
/*
* Manages consolidation of flushes and submitting any flushes needed for
* a bio with REQ_PREFLUSH. Returns true if the bio is finished or is
* being finished in another context. Returns false if the flushing is
* complete but still needs the I/O portion of the bio to be processed.
*/
bool md_flush_request(struct mddev *mddev, struct bio *bio)
{
ktime_t req_start = ktime_get_boottime();
spin_lock_irq(&mddev->lock);
/* flush requests wait until ongoing flush completes,
* hence coalescing all the pending requests.
*/
wait_event_lock_irq(mddev->sb_wait,
!mddev->flush_bio ||
ktime_before(req_start, mddev->prev_flush_start),
mddev->lock);
/* new request after previous flush is completed */
if (ktime_after(req_start, mddev->prev_flush_start)) {
WARN_ON(mddev->flush_bio);
mddev->flush_bio = bio;
bio = NULL;
}
spin_unlock_irq(&mddev->lock);
if (!bio) {
INIT_WORK(&mddev->flush_work, submit_flushes);
queue_work(md_wq, &mddev->flush_work);
} else {
/* flush was performed for some other bio while we waited. */
if (bio->bi_iter.bi_size == 0)
/* an empty barrier - all done */
bio_endio(bio);
else {
bio->bi_opf &= ~REQ_PREFLUSH;
return false;
}
}
return true;
}
EXPORT_SYMBOL(md_flush_request);
static inline struct mddev *mddev_get(struct mddev *mddev)
{
lockdep_assert_held(&all_mddevs_lock);
if (test_bit(MD_DELETED, &mddev->flags))
return NULL;
atomic_inc(&mddev->active);
return mddev;
}
static void mddev_delayed_delete(struct work_struct *ws);
void mddev_put(struct mddev *mddev)
{
if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
return;
if (!mddev->raid_disks && list_empty(&mddev->disks) &&
mddev->ctime == 0 && !mddev->hold_active) {
/* Array is not configured at all, and not held active,
* so destroy it */
set_bit(MD_DELETED, &mddev->flags);
/*
* Call queue_work inside the spinlock so that
* flush_workqueue() after mddev_find will succeed in waiting
* for the work to be done.
*/
INIT_WORK(&mddev->del_work, mddev_delayed_delete);
queue_work(md_misc_wq, &mddev->del_work);
}
spin_unlock(&all_mddevs_lock);
}
static void md_safemode_timeout(struct timer_list *t);
void mddev_init(struct mddev *mddev)
{
mutex_init(&mddev->open_mutex);
mutex_init(&mddev->reconfig_mutex);
mutex_init(&mddev->sync_mutex);
mutex_init(&mddev->bitmap_info.mutex);
INIT_LIST_HEAD(&mddev->disks);
INIT_LIST_HEAD(&mddev->all_mddevs);
INIT_LIST_HEAD(&mddev->deleting);
timer_setup(&mddev->safemode_timer, md_safemode_timeout, 0);
atomic_set(&mddev->active, 1);
atomic_set(&mddev->openers, 0);
atomic_set(&mddev->sync_seq, 0);
spin_lock_init(&mddev->lock);
atomic_set(&mddev->flush_pending, 0);
init_waitqueue_head(&mddev->sb_wait);
init_waitqueue_head(&mddev->recovery_wait);
mddev->reshape_position = MaxSector;
mddev->reshape_backwards = 0;
mddev->last_sync_action = "none";
mddev->resync_min = 0;
mddev->resync_max = MaxSector;
mddev->level = LEVEL_NONE;
}
EXPORT_SYMBOL_GPL(mddev_init);
static struct mddev *mddev_find_locked(dev_t unit)
{
struct mddev *mddev;
list_for_each_entry(mddev, &all_mddevs, all_mddevs)
if (mddev->unit == unit)
return mddev;
return NULL;
}
/* find an unused unit number */
static dev_t mddev_alloc_unit(void)
{
static int next_minor = 512;
int start = next_minor;
bool is_free = 0;
dev_t dev = 0;
while (!is_free) {
dev = MKDEV(MD_MAJOR, next_minor);
next_minor++;
if (next_minor > MINORMASK)
next_minor = 0;
if (next_minor == start)
return 0; /* Oh dear, all in use. */
is_free = !mddev_find_locked(dev);
}
return dev;
}
static struct mddev *mddev_alloc(dev_t unit)
{
struct mddev *new;
int error;
if (unit && MAJOR(unit) != MD_MAJOR)
unit &= ~((1 << MdpMinorShift) - 1);
new = kzalloc(sizeof(*new), GFP_KERNEL);
if (!new)
return ERR_PTR(-ENOMEM);
mddev_init(new);
spin_lock(&all_mddevs_lock);
if (unit) {
error = -EEXIST;
if (mddev_find_locked(unit))
goto out_free_new;
new->unit = unit;
if (MAJOR(unit) == MD_MAJOR)
new->md_minor = MINOR(unit);
else
new->md_minor = MINOR(unit) >> MdpMinorShift;
new->hold_active = UNTIL_IOCTL;
} else {
error = -ENODEV;
new->unit = mddev_alloc_unit();
if (!new->unit)
goto out_free_new;
new->md_minor = MINOR(new->unit);
new->hold_active = UNTIL_STOP;
}
list_add(&new->all_mddevs, &all_mddevs);
spin_unlock(&all_mddevs_lock);
return new;
out_free_new:
spin_unlock(&all_mddevs_lock);
kfree(new);
return ERR_PTR(error);
}
static void mddev_free(struct mddev *mddev)
{
spin_lock(&all_mddevs_lock);
list_del(&mddev->all_mddevs);
spin_unlock(&all_mddevs_lock);
kfree(mddev);
}
static const struct attribute_group md_redundancy_group;
void mddev_unlock(struct mddev *mddev)
{
struct md_rdev *rdev;
struct md_rdev *tmp;
LIST_HEAD(delete);
if (!list_empty(&mddev->deleting))
list_splice_init(&mddev->deleting, &delete);
if (mddev->to_remove) {
/* These cannot be removed under reconfig_mutex as
* an access to the files will try to take reconfig_mutex
* while holding the file unremovable, which leads to
* a deadlock.
* So hold set sysfs_active while the remove in happeing,
* and anything else which might set ->to_remove or my
* otherwise change the sysfs namespace will fail with
* -EBUSY if sysfs_active is still set.
* We set sysfs_active under reconfig_mutex and elsewhere
* test it under the same mutex to ensure its correct value
* is seen.
*/
const struct attribute_group *to_remove = mddev->to_remove;
mddev->to_remove = NULL;
mddev->sysfs_active = 1;
mutex_unlock(&mddev->reconfig_mutex);
if (mddev->kobj.sd) {
if (to_remove != &md_redundancy_group)
sysfs_remove_group(&mddev->kobj, to_remove);
if (mddev->pers == NULL ||
mddev->pers->sync_request == NULL) {
sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
if (mddev->sysfs_action)
sysfs_put(mddev->sysfs_action);
if (mddev->sysfs_completed)
sysfs_put(mddev->sysfs_completed);
if (mddev->sysfs_degraded)
sysfs_put(mddev->sysfs_degraded);
mddev->sysfs_action = NULL;
mddev->sysfs_completed = NULL;
mddev->sysfs_degraded = NULL;
}
}
mddev->sysfs_active = 0;
} else
mutex_unlock(&mddev->reconfig_mutex);
md_wakeup_thread(mddev->thread);
wake_up(&mddev->sb_wait);
list_for_each_entry_safe(rdev, tmp, &delete, same_set) {
list_del_init(&rdev->same_set);
kobject_del(&rdev->kobj);
export_rdev(rdev, mddev);
}
}
EXPORT_SYMBOL_GPL(mddev_unlock);
struct md_rdev *md_find_rdev_nr_rcu(struct mddev *mddev, int nr)
{
struct md_rdev *rdev;
rdev_for_each_rcu(rdev, mddev)
if (rdev->desc_nr == nr)
return rdev;
return NULL;
}
EXPORT_SYMBOL_GPL(md_find_rdev_nr_rcu);
static struct md_rdev *find_rdev(struct mddev *mddev, dev_t dev)
{
struct md_rdev *rdev;
rdev_for_each(rdev, mddev)
if (rdev->bdev->bd_dev == dev)
return rdev;
return NULL;
}
struct md_rdev *md_find_rdev_rcu(struct mddev *mddev, dev_t dev)
{
struct md_rdev *rdev;
rdev_for_each_rcu(rdev, mddev)
if (rdev->bdev->bd_dev == dev)
return rdev;
return NULL;
}
EXPORT_SYMBOL_GPL(md_find_rdev_rcu);
static struct md_personality *find_pers(int level, char *clevel)
{
struct md_personality *pers;
list_for_each_entry(pers, &pers_list, list) {
if (level != LEVEL_NONE && pers->level == level)
return pers;
if (strcmp(pers->name, clevel)==0)
return pers;
}
return NULL;
}
/* return the offset of the super block in 512byte sectors */
static inline sector_t calc_dev_sboffset(struct md_rdev *rdev)
{
return MD_NEW_SIZE_SECTORS(bdev_nr_sectors(rdev->bdev));
}
static int alloc_disk_sb(struct md_rdev *rdev)
{
rdev->sb_page = alloc_page(GFP_KERNEL);
if (!rdev->sb_page)
return -ENOMEM;
return 0;
}
void md_rdev_clear(struct md_rdev *rdev)
{
if (rdev->sb_page) {
put_page(rdev->sb_page);
rdev->sb_loaded = 0;
rdev->sb_page = NULL;
rdev->sb_start = 0;
rdev->sectors = 0;
}
if (rdev->bb_page) {
put_page(rdev->bb_page);
rdev->bb_page = NULL;
}
badblocks_exit(&rdev->badblocks);
}
EXPORT_SYMBOL_GPL(md_rdev_clear);
static void super_written(struct bio *bio)
{
struct md_rdev *rdev = bio->bi_private;
struct mddev *mddev = rdev->mddev;
if (bio->bi_status) {
pr_err("md: %s gets error=%d\n", __func__,
blk_status_to_errno(bio->bi_status));
md_error(mddev, rdev);
if (!test_bit(Faulty, &rdev->flags)
&& (bio->bi_opf & MD_FAILFAST)) {
set_bit(MD_SB_NEED_REWRITE, &mddev->sb_flags);
set_bit(LastDev, &rdev->flags);
}
} else
clear_bit(LastDev, &rdev->flags);
bio_put(bio);
rdev_dec_pending(rdev, mddev);
if (atomic_dec_and_test(&mddev->pending_writes))
wake_up(&mddev->sb_wait);
}
void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
sector_t sector, int size, struct page *page)
{
/* write first size bytes of page to sector of rdev
* Increment mddev->pending_writes before returning
* and decrement it on completion, waking up sb_wait
* if zero is reached.
* If an error occurred, call md_error
*/
struct bio *bio;
if (!page)
return;
if (test_bit(Faulty, &rdev->flags))
return;
bio = bio_alloc_bioset(rdev->meta_bdev ? rdev->meta_bdev : rdev->bdev,
1,
REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH | REQ_FUA,
GFP_NOIO, &mddev->sync_set);
atomic_inc(&rdev->nr_pending);
bio->bi_iter.bi_sector = sector;
__bio_add_page(bio, page, size, 0);
bio->bi_private = rdev;
bio->bi_end_io = super_written;
if (test_bit(MD_FAILFAST_SUPPORTED, &mddev->flags) &&
test_bit(FailFast, &rdev->flags) &&
!test_bit(LastDev, &rdev->flags))
bio->bi_opf |= MD_FAILFAST;
atomic_inc(&mddev->pending_writes);
submit_bio(bio);
}
int md_super_wait(struct mddev *mddev)
{
/* wait for all superblock writes that were scheduled to complete */
wait_event(mddev->sb_wait, atomic_read(&mddev->pending_writes)==0);
if (test_and_clear_bit(MD_SB_NEED_REWRITE, &mddev->sb_flags))
return -EAGAIN;
return 0;
}
int sync_page_io(struct md_rdev *rdev, sector_t sector, int size,
struct page *page, blk_opf_t opf, bool metadata_op)
{
struct bio bio;
struct bio_vec bvec;
if (metadata_op && rdev->meta_bdev)
bio_init(&bio, rdev->meta_bdev, &bvec, 1, opf);
else
bio_init(&bio, rdev->bdev, &bvec, 1, opf);
if (metadata_op)
bio.bi_iter.bi_sector = sector + rdev->sb_start;
else if (rdev->mddev->reshape_position != MaxSector &&
(rdev->mddev->reshape_backwards ==
(sector >= rdev->mddev->reshape_position)))
bio.bi_iter.bi_sector = sector + rdev->new_data_offset;
else
bio.bi_iter.bi_sector = sector + rdev->data_offset;
__bio_add_page(&bio, page, size, 0);
submit_bio_wait(&bio);
return !bio.bi_status;
}
EXPORT_SYMBOL_GPL(sync_page_io);
static int read_disk_sb(struct md_rdev *rdev, int size)
{
if (rdev->sb_loaded)
return 0;
if (!sync_page_io(rdev, 0, size, rdev->sb_page, REQ_OP_READ, true))
goto fail;
rdev->sb_loaded = 1;
return 0;
fail:
pr_err("md: disabled device %pg, could not read superblock.\n",
rdev->bdev);
return -EINVAL;
}
static int md_uuid_equal(mdp_super_t *sb1, mdp_super_t *sb2)
{
return sb1->set_uuid0 == sb2->set_uuid0 &&
sb1->set_uuid1 == sb2->set_uuid1 &&
sb1->set_uuid2 == sb2->set_uuid2 &&
sb1->set_uuid3 == sb2->set_uuid3;
}
static int md_sb_equal(mdp_super_t *sb1, mdp_super_t *sb2)
{
int ret;
mdp_super_t *tmp1, *tmp2;
tmp1 = kmalloc(sizeof(*tmp1),GFP_KERNEL);
tmp2 = kmalloc(sizeof(*tmp2),GFP_KERNEL);
if (!tmp1 || !tmp2) {
ret = 0;
goto abort;
}
*tmp1 = *sb1;
*tmp2 = *sb2;
/*
* nr_disks is not constant
*/
tmp1->nr_disks = 0;
tmp2->nr_disks = 0;
ret = (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4) == 0);
abort:
kfree(tmp1);
kfree(tmp2);
return ret;
}
static u32 md_csum_fold(u32 csum)
{
csum = (csum & 0xffff) + (csum >> 16);
return (csum & 0xffff) + (csum >> 16);
}
static unsigned int calc_sb_csum(mdp_super_t *sb)
{
u64 newcsum = 0;
u32 *sb32 = (u32*)sb;
int i;
unsigned int disk_csum, csum;
disk_csum = sb->sb_csum;
sb->sb_csum = 0;
for (i = 0; i < MD_SB_BYTES/4 ; i++)
newcsum += sb32[i];
csum = (newcsum & 0xffffffff) + (newcsum>>32);
#ifdef CONFIG_ALPHA
/* This used to use csum_partial, which was wrong for several
* reasons including that different results are returned on
* different architectures. It isn't critical that we get exactly
* the same return value as before (we always csum_fold before
* testing, and that removes any differences). However as we
* know that csum_partial always returned a 16bit value on
* alphas, do a fold to maximise conformity to previous behaviour.
*/
sb->sb_csum = md_csum_fold(disk_csum);
#else
sb->sb_csum = disk_csum;
#endif
return csum;
}
/*
* Handle superblock details.
* We want to be able to handle multiple superblock formats
* so we have a common interface to them all, and an array of
* different handlers.
* We rely on user-space to write the initial superblock, and support
* reading and updating of superblocks.
* Interface methods are:
* int load_super(struct md_rdev *dev, struct md_rdev *refdev, int minor_version)
* loads and validates a superblock on dev.
* if refdev != NULL, compare superblocks on both devices
* Return:
* 0 - dev has a superblock that is compatible with refdev
* 1 - dev has a superblock that is compatible and newer than refdev
* so dev should be used as the refdev in future
* -EINVAL superblock incompatible or invalid
* -othererror e.g. -EIO
*
* int validate_super(struct mddev *mddev, struct md_rdev *dev)
* Verify that dev is acceptable into mddev.
* The first time, mddev->raid_disks will be 0, and data from
* dev should be merged in. Subsequent calls check that dev
* is new enough. Return 0 or -EINVAL
*
* void sync_super(struct mddev *mddev, struct md_rdev *dev)
* Update the superblock for rdev with data in mddev
* This does not write to disc.
*
*/
struct super_type {
char *name;
struct module *owner;
int (*load_super)(struct md_rdev *rdev,
struct md_rdev *refdev,
int minor_version);
int (*validate_super)(struct mddev *mddev,
struct md_rdev *rdev);
void (*sync_super)(struct mddev *mddev,
struct md_rdev *rdev);
unsigned long long (*rdev_size_change)(struct md_rdev *rdev,
sector_t num_sectors);
int (*allow_new_offset)(struct md_rdev *rdev,
unsigned long long new_offset);
};
/*
* Check that the given mddev has no bitmap.
*
* This function is called from the run method of all personalities that do not
* support bitmaps. It prints an error message and returns non-zero if mddev
* has a bitmap. Otherwise, it returns 0.
*
*/
int md_check_no_bitmap(struct mddev *mddev)
{
if (!mddev->bitmap_info.file && !mddev->bitmap_info.offset)
return 0;
pr_warn("%s: bitmaps are not supported for %s\n",
mdname(mddev), mddev->pers->name);
return 1;
}
EXPORT_SYMBOL(md_check_no_bitmap);
/*
* load_super for 0.90.0
*/
static int super_90_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_version)
{
mdp_super_t *sb;
int ret;
bool spare_disk = true;
/*
* Calculate the position of the superblock (512byte sectors),
* it's at the end of the disk.
*
* It also happens to be a multiple of 4Kb.
*/
rdev->sb_start = calc_dev_sboffset(rdev);
ret = read_disk_sb(rdev, MD_SB_BYTES);
if (ret)
return ret;
ret = -EINVAL;
sb = page_address(rdev->sb_page);
if (sb->md_magic != MD_SB_MAGIC) {
pr_warn("md: invalid raid superblock magic on %pg\n",
rdev->bdev);
goto abort;
}
if (sb->major_version != 0 ||
sb->minor_version < 90 ||
sb->minor_version > 91) {
pr_warn("Bad version number %d.%d on %pg\n",
sb->major_version, sb->minor_version, rdev->bdev);
goto abort;
}
if (sb->raid_disks <= 0)
goto abort;
if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
pr_warn("md: invalid superblock checksum on %pg\n", rdev->bdev);
goto abort;
}
rdev->preferred_minor = sb->md_minor;
rdev->data_offset = 0;
rdev->new_data_offset = 0;
rdev->sb_size = MD_SB_BYTES;
rdev->badblocks.shift = -1;
if (sb->level == LEVEL_MULTIPATH)
rdev->desc_nr = -1;
else
rdev->desc_nr = sb->this_disk.number;
/* not spare disk, or LEVEL_MULTIPATH */
if (sb->level == LEVEL_MULTIPATH ||
(rdev->desc_nr >= 0 &&
rdev->desc_nr < MD_SB_DISKS &&
sb->disks[rdev->desc_nr].state &
((1<<MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE))))
spare_disk = false;
if (!refdev) {
if (!spare_disk)
ret = 1;
else
ret = 0;
} else {
__u64 ev1, ev2;
mdp_super_t *refsb = page_address(refdev->sb_page);
if (!md_uuid_equal(refsb, sb)) {
pr_warn("md: %pg has different UUID to %pg\n",
rdev->bdev, refdev->bdev);
goto abort;
}
if (!md_sb_equal(refsb, sb)) {
pr_warn("md: %pg has same UUID but different superblock to %pg\n",
rdev->bdev, refdev->bdev);
goto abort;
}
ev1 = md_event(sb);
ev2 = md_event(refsb);
if (!spare_disk && ev1 > ev2)
ret = 1;
else
ret = 0;
}
rdev->sectors = rdev->sb_start;
/* Limit to 4TB as metadata cannot record more than that.
* (not needed for Linear and RAID0 as metadata doesn't
* record this size)
*/
if ((u64)rdev->sectors >= (2ULL << 32) && sb->level >= 1)
rdev->sectors = (sector_t)(2ULL << 32) - 2;
if (rdev->sectors < ((sector_t)sb->size) * 2 && sb->level >= 1)
/* "this cannot possibly happen" ... */
ret = -EINVAL;
abort:
return ret;
}
/*
* validate_super for 0.90.0
*/
static int super_90_validate(struct mddev *mddev, struct md_rdev *rdev)
{
mdp_disk_t *desc;
mdp_super_t *sb = page_address(rdev->sb_page);
__u64 ev1 = md_event(sb);
rdev->raid_disk = -1;
clear_bit(Faulty, &rdev->flags);
clear_bit(In_sync, &rdev->flags);
clear_bit(Bitmap_sync, &rdev->flags);
clear_bit(WriteMostly, &rdev->flags);
if (mddev->raid_disks == 0) {
mddev->major_version = 0;
mddev->minor_version = sb->minor_version;
mddev->patch_version = sb->patch_version;
mddev->external = 0;
mddev->chunk_sectors = sb->chunk_size >> 9;
mddev->ctime = sb->ctime;
mddev->utime = sb->utime;
mddev->level = sb->level;
mddev->clevel[0] = 0;
mddev->layout = sb->layout;
mddev->raid_disks = sb->raid_disks;
mddev->dev_sectors = ((sector_t)sb->size) * 2;
mddev->events = ev1;
mddev->bitmap_info.offset = 0;
mddev->bitmap_info.space = 0;
/* bitmap can use 60 K after the 4K superblocks */
mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
mddev->bitmap_info.default_space = 64*2 - (MD_SB_BYTES >> 9);
mddev->reshape_backwards = 0;
if (mddev->minor_version >= 91) {
mddev->reshape_position = sb->reshape_position;
mddev->delta_disks = sb->delta_disks;
mddev->new_level = sb->new_level;
mddev->new_layout = sb->new_layout;
mddev->new_chunk_sectors = sb->new_chunk >> 9;
if (mddev->delta_disks < 0)
mddev->reshape_backwards = 1;
} else {
mddev->reshape_position = MaxSector;
mddev->delta_disks = 0;
mddev->new_level = mddev->level;
mddev->new_layout = mddev->layout;
mddev->new_chunk_sectors = mddev->chunk_sectors;
}
if (mddev->level == 0)
mddev->layout = -1;
if (sb->state & (1<<MD_SB_CLEAN))
mddev->recovery_cp = MaxSector;
else {
if (sb->events_hi == sb->cp_events_hi &&
sb->events_lo == sb->cp_events_lo) {
mddev->recovery_cp = sb->recovery_cp;
} else
mddev->recovery_cp = 0;
}
memcpy(mddev->uuid+0, &sb->set_uuid0, 4);
memcpy(mddev->uuid+4, &sb->set_uuid1, 4);
memcpy(mddev->uuid+8, &sb->set_uuid2, 4);
memcpy(mddev->uuid+12,&sb->set_uuid3, 4);
mddev->max_disks = MD_SB_DISKS;
if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
mddev->bitmap_info.file == NULL) {
mddev->bitmap_info.offset =
mddev->bitmap_info.default_offset;
mddev->bitmap_info.space =
mddev->bitmap_info.default_space;
}
} else if (mddev->pers == NULL) {
/* Insist on good event counter while assembling, except
* for spares (which don't need an event count) */
++ev1;
if (sb->disks[rdev->desc_nr].state & (
(1<<MD_DISK_SYNC) | (1 << MD_DISK_ACTIVE)))
if (ev1 < mddev->events)
return -EINVAL;
} else if (mddev->bitmap) {
/* if adding to array with a bitmap, then we can accept an
* older device ... but not too old.
*/
if (ev1 < mddev->bitmap->events_cleared)
return 0;
if (ev1 < mddev->events)
set_bit(Bitmap_sync, &rdev->flags);
} else {
if (ev1 < mddev->events)
/* just a hot-add of a new device, leave raid_disk at -1 */
return 0;
}
if (mddev->level != LEVEL_MULTIPATH) {
desc = sb->disks + rdev->desc_nr;
if (desc->state & (1<<MD_DISK_FAULTY))
set_bit(Faulty, &rdev->flags);
else if (desc->state & (1<<MD_DISK_SYNC) /* &&
desc->raid_disk < mddev->raid_disks */) {
set_bit(In_sync, &rdev->flags);
rdev->raid_disk = desc->raid_disk;
rdev->saved_raid_disk = desc->raid_disk;
} else if (desc->state & (1<<MD_DISK_ACTIVE)) {
/* active but not in sync implies recovery up to
* reshape position. We don't know exactly where
* that is, so set to zero for now */
if (mddev->minor_version >= 91) {
rdev->recovery_offset = 0;
rdev->raid_disk = desc->raid_disk;
}
}
if (desc->state & (1<<MD_DISK_WRITEMOSTLY))
set_bit(WriteMostly, &rdev->flags);
if (desc->state & (1<<MD_DISK_FAILFAST))
set_bit(FailFast, &rdev->flags);
} else /* MULTIPATH are always insync */
set_bit(In_sync, &rdev->flags);
return 0;
}
/*
* sync_super for 0.90.0
*/
static void super_90_sync(struct mddev *mddev, struct md_rdev *rdev)
{
mdp_super_t *sb;
struct md_rdev *rdev2;
int next_spare = mddev->raid_disks;
/* make rdev->sb match mddev data..
*
* 1/ zero out disks
* 2/ Add info for each disk, keeping track of highest desc_nr (next_spare);
* 3/ any empty disks < next_spare become removed
*
* disks[0] gets initialised to REMOVED because
* we cannot be sure from other fields if it has
* been initialised or not.
*/
int i;
int active=0, working=0,failed=0,spare=0,nr_disks=0;
rdev->sb_size = MD_SB_BYTES;
sb = page_address(rdev->sb_page);
memset(sb, 0, sizeof(*sb));
sb->md_magic = MD_SB_MAGIC;
sb->major_version = mddev->major_version;
sb->patch_version = mddev->patch_version;
sb->gvalid_words = 0; /* ignored */
memcpy(&sb->set_uuid0, mddev->uuid+0, 4);
memcpy(&sb->set_uuid1, mddev->uuid+4, 4);
memcpy(&sb->set_uuid2, mddev->uuid+8, 4);
memcpy(&sb->set_uuid3, mddev->uuid+12,4);
sb->ctime = clamp_t(time64_t, mddev->ctime, 0, U32_MAX);
sb->level = mddev->level;
sb->size = mddev->dev_sectors / 2;
sb->raid_disks = mddev->raid_disks;
sb->md_minor = mddev->md_minor;
sb->not_persistent = 0;
sb->utime = clamp_t(time64_t, mddev->utime, 0, U32_MAX);
sb->state = 0;
sb->events_hi = (mddev->events>>32);
sb->events_lo = (u32)mddev->events;
if (mddev->reshape_position == MaxSector)
sb->minor_version = 90;
else {
sb->minor_version = 91;
sb->reshape_position = mddev->reshape_position;
sb->new_level = mddev->new_level;
sb->delta_disks = mddev->delta_disks;
sb->new_layout = mddev->new_layout;
sb->new_chunk = mddev->new_chunk_sectors << 9;
}
mddev->minor_version = sb->minor_version;
if (mddev->in_sync)
{
sb->recovery_cp = mddev->recovery_cp;
sb->cp_events_hi = (mddev->events>>32);
sb->cp_events_lo = (u32)mddev->events;
if (mddev->recovery_cp == MaxSector)
sb->state = (1<< MD_SB_CLEAN);
} else
sb->recovery_cp = 0;
sb->layout = mddev->layout;
sb->chunk_size = mddev->chunk_sectors << 9;
if (mddev->bitmap && mddev->bitmap_info.file == NULL)
sb->state |= (1<<MD_SB_BITMAP_PRESENT);
sb->disks[0].state = (1<<MD_DISK_REMOVED);
rdev_for_each(rdev2, mddev) {
mdp_disk_t *d;
int desc_nr;
int is_active = test_bit(In_sync, &rdev2->flags);
if (rdev2->raid_disk >= 0 &&
sb->minor_version >= 91)
/* we have nowhere to store the recovery_offset,
* but if it is not below the reshape_position,
* we can piggy-back on that.
*/
is_active = 1;
if (rdev2->raid_disk < 0 ||
test_bit(Faulty, &rdev2->flags))
is_active = 0;
if (is_active)
desc_nr = rdev2->raid_disk;
else
desc_nr = next_spare++;
rdev2->desc_nr = desc_nr;
d = &sb->disks[rdev2->desc_nr];
nr_disks++;
d->number = rdev2->desc_nr;
d->major = MAJOR(rdev2->bdev->bd_dev);
d->minor = MINOR(rdev2->bdev->bd_dev);
if (is_active)
d->raid_disk = rdev2->raid_disk;
else
d->raid_disk = rdev2->desc_nr; /* compatibility */
if (test_bit(Faulty, &rdev2->flags))
d->state = (1<<MD_DISK_FAULTY);
else if (is_active) {
d->state = (1<<MD_DISK_ACTIVE);
if (test_bit(In_sync, &rdev2->flags))
d->state |= (1<<MD_DISK_SYNC);
active++;
working++;
} else {
d->state = 0;
spare++;
working++;
}
if (test_bit(WriteMostly, &rdev2->flags))
d->state |= (1<<MD_DISK_WRITEMOSTLY);
if (test_bit(FailFast, &rdev2->flags))
d->state |= (1<<MD_DISK_FAILFAST);
}
/* now set the "removed" and "faulty" bits on any missing devices */
for (i=0 ; i < mddev->raid_disks ; i++) {
mdp_disk_t *d = &sb->disks[i];
if (d->state == 0 && d->number == 0) {
d->number = i;
d->raid_disk = i;
d->state = (1<<MD_DISK_REMOVED);
d->state |= (1<<MD_DISK_FAULTY);
failed++;
}
}
sb->nr_disks = nr_disks;
sb->active_disks = active;
sb->working_disks = working;
sb->failed_disks = failed;
sb->spare_disks = spare;
sb->this_disk = sb->disks[rdev->desc_nr];
sb->sb_csum = calc_sb_csum(sb);
}
/*
* rdev_size_change for 0.90.0
*/
static unsigned long long
super_90_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
{
if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
return 0; /* component must fit device */
if (rdev->mddev->bitmap_info.offset)
return 0; /* can't move bitmap */
rdev->sb_start = calc_dev_sboffset(rdev);
if (!num_sectors || num_sectors > rdev->sb_start)
num_sectors = rdev->sb_start;
/* Limit to 4TB as metadata cannot record more than that.
* 4TB == 2^32 KB, or 2*2^32 sectors.
*/
if ((u64)num_sectors >= (2ULL << 32) && rdev->mddev->level >= 1)
num_sectors = (sector_t)(2ULL << 32) - 2;
do {
md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
rdev->sb_page);
} while (md_super_wait(rdev->mddev) < 0);
return num_sectors;
}
static int
super_90_allow_new_offset(struct md_rdev *rdev, unsigned long long new_offset)
{
/* non-zero offset changes not possible with v0.90 */
return new_offset == 0;
}
/*
* version 1 superblock
*/
static __le32 calc_sb_1_csum(struct mdp_superblock_1 *sb)
{
__le32 disk_csum;
u32 csum;
unsigned long long newcsum;
int size = 256 + le32_to_cpu(sb->max_dev)*2;
__le32 *isuper = (__le32*)sb;
disk_csum = sb->sb_csum;
sb->sb_csum = 0;
newcsum = 0;
for (; size >= 4; size -= 4)
newcsum += le32_to_cpu(*isuper++);
if (size == 2)
newcsum += le16_to_cpu(*(__le16*) isuper);
csum = (newcsum & 0xffffffff) + (newcsum >> 32);
sb->sb_csum = disk_csum;
return cpu_to_le32(csum);
}
static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_version)
{
struct mdp_superblock_1 *sb;
int ret;
sector_t sb_start;
sector_t sectors;
int bmask;
bool spare_disk = true;
/*
* Calculate the position of the superblock in 512byte sectors.
* It is always aligned to a 4K boundary and
* depeding on minor_version, it can be:
* 0: At least 8K, but less than 12K, from end of device
* 1: At start of device
* 2: 4K from start of device.
*/
switch(minor_version) {
case 0:
sb_start = bdev_nr_sectors(rdev->bdev) - 8 * 2;
sb_start &= ~(sector_t)(4*2-1);
break;
case 1:
sb_start = 0;
break;
case 2:
sb_start = 8;
break;
default:
return -EINVAL;
}
rdev->sb_start = sb_start;
/* superblock is rarely larger than 1K, but it can be larger,
* and it is safe to read 4k, so we do that
*/
ret = read_disk_sb(rdev, 4096);
if (ret) return ret;
sb = page_address(rdev->sb_page);
if (sb->magic != cpu_to_le32(MD_SB_MAGIC) ||
sb->major_version != cpu_to_le32(1) ||
le32_to_cpu(sb->max_dev) > (4096-256)/2 ||
le64_to_cpu(sb->super_offset) != rdev->sb_start ||
(le32_to_cpu(sb->feature_map) & ~MD_FEATURE_ALL) != 0)
return -EINVAL;
if (calc_sb_1_csum(sb) != sb->sb_csum) {
pr_warn("md: invalid superblock checksum on %pg\n",
rdev->bdev);
return -EINVAL;
}
if (le64_to_cpu(sb->data_size) < 10) {
pr_warn("md: data_size too small on %pg\n",
rdev->bdev);
return -EINVAL;
}
if (sb->pad0 ||
sb->pad3[0] ||
memcmp(sb->pad3, sb->pad3+1, sizeof(sb->pad3) - sizeof(sb->pad3[1])))
/* Some padding is non-zero, might be a new feature */
return -EINVAL;
rdev->preferred_minor = 0xffff;
rdev->data_offset = le64_to_cpu(sb->data_offset);
rdev->new_data_offset = rdev->data_offset;
if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE) &&
(le32_to_cpu(sb->feature_map) & MD_FEATURE_NEW_OFFSET))
rdev->new_data_offset += (s32)le32_to_cpu(sb->new_offset);
atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
if (rdev->sb_size & bmask)
rdev->sb_size = (rdev->sb_size | bmask) + 1;
if (minor_version
&& rdev->data_offset < sb_start + (rdev->sb_size/512))
return -EINVAL;
if (minor_version
&& rdev->new_data_offset < sb_start + (rdev->sb_size/512))
return -EINVAL;
if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
rdev->desc_nr = -1;
else
rdev->desc_nr = le32_to_cpu(sb->dev_number);
if (!rdev->bb_page) {
rdev->bb_page = alloc_page(GFP_KERNEL);
if (!rdev->bb_page)
return -ENOMEM;
}
if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BAD_BLOCKS) &&
rdev->badblocks.count == 0) {
/* need to load the bad block list.
* Currently we limit it to one page.
*/
s32 offset;
sector_t bb_sector;
__le64 *bbp;
int i;
int sectors = le16_to_cpu(sb->bblog_size);
if (sectors > (PAGE_SIZE / 512))
return -EINVAL;
offset = le32_to_cpu(sb->bblog_offset);
if (offset == 0)
return -EINVAL;
bb_sector = (long long)offset;
if (!sync_page_io(rdev, bb_sector, sectors << 9,
rdev->bb_page, REQ_OP_READ, true))
return -EIO;
bbp = (__le64 *)page_address(rdev->bb_page);
rdev->badblocks.shift = sb->bblog_shift;
for (i = 0 ; i < (sectors << (9-3)) ; i++, bbp++) {
u64 bb = le64_to_cpu(*bbp);
int count = bb & (0x3ff);
u64 sector = bb >> 10;
sector <<= sb->bblog_shift;
count <<= sb->bblog_shift;
if (bb + 1 == 0)
break;
if (badblocks_set(&rdev->badblocks, sector, count, 1))
return -EINVAL;
}
} else if (sb->bblog_offset != 0)
rdev->badblocks.shift = 0;
if ((le32_to_cpu(sb->feature_map) &
(MD_FEATURE_PPL | MD_FEATURE_MULTIPLE_PPLS))) {
rdev->ppl.offset = (__s16)le16_to_cpu(sb->ppl.offset);
rdev->ppl.size = le16_to_cpu(sb->ppl.size);
rdev->ppl.sector = rdev->sb_start + rdev->ppl.offset;
}
if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RAID0_LAYOUT) &&
sb->level != 0)
return -EINVAL;
/* not spare disk, or LEVEL_MULTIPATH */
if (sb->level == cpu_to_le32(LEVEL_MULTIPATH) ||
(rdev->desc_nr >= 0 &&
rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
(le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < MD_DISK_ROLE_MAX ||
le16_to_cpu(sb->dev_roles[rdev->desc_nr]) == MD_DISK_ROLE_JOURNAL)))
spare_disk = false;
if (!refdev) {
if (!spare_disk)
ret = 1;
else
ret = 0;
} else {
__u64 ev1, ev2;
struct mdp_superblock_1 *refsb = page_address(refdev->sb_page);
if (memcmp(sb->set_uuid, refsb->set_uuid, 16) != 0 ||
sb->level != refsb->level ||
sb->layout != refsb->layout ||
sb->chunksize != refsb->chunksize) {
pr_warn("md: %pg has strangely different superblock to %pg\n",
rdev->bdev,
refdev->bdev);
return -EINVAL;
}
ev1 = le64_to_cpu(sb->events);
ev2 = le64_to_cpu(refsb->events);
if (!spare_disk && ev1 > ev2)
ret = 1;
else
ret = 0;
}
if (minor_version)
sectors = bdev_nr_sectors(rdev->bdev) - rdev->data_offset;
else
sectors = rdev->sb_start;
if (sectors < le64_to_cpu(sb->data_size))
return -EINVAL;
rdev->sectors = le64_to_cpu(sb->data_size);
return ret;
}
static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev)
{
struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
__u64 ev1 = le64_to_cpu(sb->events);
rdev->raid_disk = -1;
clear_bit(Faulty, &rdev->flags);
clear_bit(In_sync, &rdev->flags);
clear_bit(Bitmap_sync, &rdev->flags);
clear_bit(WriteMostly, &rdev->flags);
if (mddev->raid_disks == 0) {
mddev->major_version = 1;
mddev->patch_version = 0;
mddev->external = 0;
mddev->chunk_sectors = le32_to_cpu(sb->chunksize);
mddev->ctime = le64_to_cpu(sb->ctime);
mddev->utime = le64_to_cpu(sb->utime);
mddev->level = le32_to_cpu(sb->level);
mddev->clevel[0] = 0;
mddev->layout = le32_to_cpu(sb->layout);
mddev->raid_disks = le32_to_cpu(sb->raid_disks);
mddev->dev_sectors = le64_to_cpu(sb->size);
mddev->events = ev1;
mddev->bitmap_info.offset = 0;
mddev->bitmap_info.space = 0;
/* Default location for bitmap is 1K after superblock
* using 3K - total of 4K
*/
mddev->bitmap_info.default_offset = 1024 >> 9;
mddev->bitmap_info.default_space = (4096-1024) >> 9;
mddev->reshape_backwards = 0;
mddev->recovery_cp = le64_to_cpu(sb->resync_offset);
memcpy(mddev->uuid, sb->set_uuid, 16);
mddev->max_disks = (4096-256)/2;
if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
mddev->bitmap_info.file == NULL) {
mddev->bitmap_info.offset =
(__s32)le32_to_cpu(sb->bitmap_offset);
/* Metadata doesn't record how much space is available.
* For 1.0, we assume we can use up to the superblock
* if before, else to 4K beyond superblock.
* For others, assume no change is possible.
*/
if (mddev->minor_version > 0)
mddev->bitmap_info.space = 0;
else if (mddev->bitmap_info.offset > 0)
mddev->bitmap_info.space =
8 - mddev->bitmap_info.offset;
else
mddev->bitmap_info.space =
-mddev->bitmap_info.offset;
}
if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
mddev->reshape_position = le64_to_cpu(sb->reshape_position);
mddev->delta_disks = le32_to_cpu(sb->delta_disks);
mddev->new_level = le32_to_cpu(sb->new_level);
mddev->new_layout = le32_to_cpu(sb->new_layout);
mddev->new_chunk_sectors = le32_to_cpu(sb->new_chunk);
if (mddev->delta_disks < 0 ||
(mddev->delta_disks == 0 &&
(le32_to_cpu(sb->feature_map)
& MD_FEATURE_RESHAPE_BACKWARDS)))
mddev->reshape_backwards = 1;
} else {
mddev->reshape_position = MaxSector;
mddev->delta_disks = 0;
mddev->new_level = mddev->level;
mddev->new_layout = mddev->layout;
mddev->new_chunk_sectors = mddev->chunk_sectors;
}
if (mddev->level == 0 &&
!(le32_to_cpu(sb->feature_map) & MD_FEATURE_RAID0_LAYOUT))
mddev->layout = -1;
if (le32_to_cpu(sb->feature_map) & MD_FEATURE_JOURNAL)
set_bit(MD_HAS_JOURNAL, &mddev->flags);
if (le32_to_cpu(sb->feature_map) &
(MD_FEATURE_PPL | MD_FEATURE_MULTIPLE_PPLS)) {
if (le32_to_cpu(sb->feature_map) &
(MD_FEATURE_BITMAP_OFFSET | MD_FEATURE_JOURNAL))
return -EINVAL;
if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_PPL) &&
(le32_to_cpu(sb->feature_map) &
MD_FEATURE_MULTIPLE_PPLS))
return -EINVAL;
set_bit(MD_HAS_PPL, &mddev->flags);
}
} else if (mddev->pers == NULL) {
/* Insist of good event counter while assembling, except for
* spares (which don't need an event count) */
++ev1;
if (rdev->desc_nr >= 0 &&
rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
(le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < MD_DISK_ROLE_MAX ||
le16_to_cpu(sb->dev_roles[rdev->desc_nr]) == MD_DISK_ROLE_JOURNAL))
if (ev1 < mddev->events)
return -EINVAL;
} else if (mddev->bitmap) {
/* If adding to array with a bitmap, then we can accept an
* older device, but not too old.
*/
if (ev1 < mddev->bitmap->events_cleared)
return 0;
if (ev1 < mddev->events)
set_bit(Bitmap_sync, &rdev->flags);
} else {
if (ev1 < mddev->events)
/* just a hot-add of a new device, leave raid_disk at -1 */
return 0;
}
if (mddev->level != LEVEL_MULTIPATH) {
int role;
if (rdev->desc_nr < 0 ||
rdev->desc_nr >= le32_to_cpu(sb->max_dev)) {
role = MD_DISK_ROLE_SPARE;
rdev->desc_nr = -1;
} else
role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
switch(role) {
case MD_DISK_ROLE_SPARE: /* spare */
break;
case MD_DISK_ROLE_FAULTY: /* faulty */
set_bit(Faulty, &rdev->flags);
break;
case MD_DISK_ROLE_JOURNAL: /* journal device */
if (!(le32_to_cpu(sb->feature_map) & MD_FEATURE_JOURNAL)) {
/* journal device without journal feature */
pr_warn("md: journal device provided without journal feature, ignoring the device\n");
return -EINVAL;
}
set_bit(Journal, &rdev->flags);
rdev->journal_tail = le64_to_cpu(sb->journal_tail);
rdev->raid_disk = 0;
break;
default:
rdev->saved_raid_disk = role;
if ((le32_to_cpu(sb->feature_map) &
MD_FEATURE_RECOVERY_OFFSET)) {
rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
if (!(le32_to_cpu(sb->feature_map) &
MD_FEATURE_RECOVERY_BITMAP))
rdev->saved_raid_disk = -1;
} else {
/*
* If the array is FROZEN, then the device can't
* be in_sync with rest of array.
*/
if (!test_bit(MD_RECOVERY_FROZEN,
&mddev->recovery))
set_bit(In_sync, &rdev->flags);
}
rdev->raid_disk = role;
break;
}
if (sb->devflags & WriteMostly1)
set_bit(WriteMostly, &rdev->flags);
if (sb->devflags & FailFast1)
set_bit(FailFast, &rdev->flags);
if (le32_to_cpu(sb->feature_map) & MD_FEATURE_REPLACEMENT)
set_bit(Replacement, &rdev->flags);
} else /* MULTIPATH are always insync */
set_bit(In_sync, &rdev->flags);
return 0;
}
static void super_1_sync(struct mddev *mddev, struct md_rdev *rdev)
{
struct mdp_superblock_1 *sb;
struct md_rdev *rdev2;
int max_dev, i;
/* make rdev->sb match mddev and rdev data. */
sb = page_address(rdev->sb_page);
sb->feature_map = 0;
sb->pad0 = 0;
sb->recovery_offset = cpu_to_le64(0);
memset(sb->pad3, 0, sizeof(sb->pad3));
sb->utime = cpu_to_le64((__u64)mddev->utime);
sb->events = cpu_to_le64(mddev->events);
if (mddev->in_sync)
sb->resync_offset = cpu_to_le64(mddev->recovery_cp);
else if (test_bit(MD_JOURNAL_CLEAN, &mddev->flags))
sb->resync_offset = cpu_to_le64(MaxSector);
else
sb->resync_offset = cpu_to_le64(0);
sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
sb->raid_disks = cpu_to_le32(mddev->raid_disks);
sb->size = cpu_to_le64(mddev->dev_sectors);
sb->chunksize = cpu_to_le32(mddev->chunk_sectors);
sb->level = cpu_to_le32(mddev->level);
sb->layout = cpu_to_le32(mddev->layout);
if (test_bit(FailFast, &rdev->flags))
sb->devflags |= FailFast1;
else
sb->devflags &= ~FailFast1;
if (test_bit(WriteMostly, &rdev->flags))
sb->devflags |= WriteMostly1;
else
sb->devflags &= ~WriteMostly1;
sb->data_offset = cpu_to_le64(rdev->data_offset);
sb->data_size = cpu_to_le64(rdev->sectors);
if (mddev->bitmap && mddev->bitmap_info.file == NULL) {
sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_info.offset);
sb->feature_map = cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
}
if (rdev->raid_disk >= 0 && !test_bit(Journal, &rdev->flags) &&
!test_bit(In_sync, &rdev->flags)) {
sb->feature_map |=
cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
sb->recovery_offset =
cpu_to_le64(rdev->recovery_offset);
if (rdev->saved_raid_disk >= 0 && mddev->bitmap)
sb->feature_map |=
cpu_to_le32(MD_FEATURE_RECOVERY_BITMAP);
}
/* Note: recovery_offset and journal_tail share space */
if (test_bit(Journal, &rdev->flags))
sb->journal_tail = cpu_to_le64(rdev->journal_tail);
if (test_bit(Replacement, &rdev->flags))
sb->feature_map |=
cpu_to_le32(MD_FEATURE_REPLACEMENT);
if (mddev->reshape_position != MaxSector) {
sb->feature_map |= cpu_to_le32(MD_FEATURE_RESHAPE_ACTIVE);
sb->reshape_position = cpu_to_le64(mddev->reshape_position);
sb->new_layout = cpu_to_le32(mddev->new_layout);
sb->delta_disks = cpu_to_le32(mddev->delta_disks);
sb->new_level = cpu_to_le32(mddev->new_level);
sb->new_chunk = cpu_to_le32(mddev->new_chunk_sectors);
if (mddev->delta_disks == 0 &&
mddev->reshape_backwards)
sb->feature_map
|= cpu_to_le32(MD_FEATURE_RESHAPE_BACKWARDS);
if (rdev->new_data_offset != rdev->data_offset) {
sb->feature_map
|= cpu_to_le32(MD_FEATURE_NEW_OFFSET);
sb->new_offset = cpu_to_le32((__u32)(rdev->new_data_offset
- rdev->data_offset));
}
}
if (mddev_is_clustered(mddev))
sb->feature_map |= cpu_to_le32(MD_FEATURE_CLUSTERED);
if (rdev->badblocks.count == 0)
/* Nothing to do for bad blocks*/ ;
else if (sb->bblog_offset == 0)
/* Cannot record bad blocks on this device */
md_error(mddev, rdev);
else {
struct badblocks *bb = &rdev->badblocks;
__le64 *bbp = (__le64 *)page_address(rdev->bb_page);
u64 *p = bb->page;
sb->feature_map |= cpu_to_le32(MD_FEATURE_BAD_BLOCKS);
if (bb->changed) {
unsigned seq;
retry:
seq = read_seqbegin(&bb->lock);
memset(bbp, 0xff, PAGE_SIZE);
for (i = 0 ; i < bb->count ; i++) {
u64 internal_bb = p[i];
u64 store_bb = ((BB_OFFSET(internal_bb) << 10)
| BB_LEN(internal_bb));
bbp[i] = cpu_to_le64(store_bb);
}
bb->changed = 0;
if (read_seqretry(&bb->lock, seq))
goto retry;
bb->sector = (rdev->sb_start +
(int)le32_to_cpu(sb->bblog_offset));
bb->size = le16_to_cpu(sb->bblog_size);
}
}
max_dev = 0;
rdev_for_each(rdev2, mddev)
if (rdev2->desc_nr+1 > max_dev)
max_dev = rdev2->desc_nr+1;
if (max_dev > le32_to_cpu(sb->max_dev)) {
int bmask;
sb->max_dev = cpu_to_le32(max_dev);
rdev->sb_size = max_dev * 2 + 256;
bmask = queue_logical_block_size(rdev->bdev->bd_disk->queue)-1;
if (rdev->sb_size & bmask)
rdev->sb_size = (rdev->sb_size | bmask) + 1;
} else
max_dev = le32_to_cpu(sb->max_dev);
for (i=0; i<max_dev;i++)
sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_SPARE);
if (test_bit(MD_HAS_JOURNAL, &mddev->flags))
sb->feature_map |= cpu_to_le32(MD_FEATURE_JOURNAL);
if (test_bit(MD_HAS_PPL, &mddev->flags)) {
if (test_bit(MD_HAS_MULTIPLE_PPLS, &mddev->flags))
sb->feature_map |=
cpu_to_le32(MD_FEATURE_MULTIPLE_PPLS);
else
sb->feature_map |= cpu_to_le32(MD_FEATURE_PPL);
sb->ppl.offset = cpu_to_le16(rdev->ppl.offset);
sb->ppl.size = cpu_to_le16(rdev->ppl.size);
}
rdev_for_each(rdev2, mddev) {
i = rdev2->desc_nr;
if (test_bit(Faulty, &rdev2->flags))
sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_FAULTY);
else if (test_bit(In_sync, &rdev2->flags))
sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
else if (test_bit(Journal, &rdev2->flags))
sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_JOURNAL);
else if (rdev2->raid_disk >= 0)
sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
else
sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_SPARE);
}
sb->sb_csum = calc_sb_1_csum(sb);
}
static sector_t super_1_choose_bm_space(sector_t dev_size)
{
sector_t bm_space;
/* if the device is bigger than 8Gig, save 64k for bitmap
* usage, if bigger than 200Gig, save 128k
*/
if (dev_size < 64*2)
bm_space = 0;
else if (dev_size - 64*2 >= 200*1024*1024*2)
bm_space = 128*2;
else if (dev_size - 4*2 > 8*1024*1024*2)
bm_space = 64*2;
else
bm_space = 4*2;
return bm_space;
}
static unsigned long long
super_1_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
{
struct mdp_superblock_1 *sb;
sector_t max_sectors;
if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
return 0; /* component must fit device */
if (rdev->data_offset != rdev->new_data_offset)
return 0; /* too confusing */
if (rdev->sb_start < rdev->data_offset) {
/* minor versions 1 and 2; superblock before data */
max_sectors = bdev_nr_sectors(rdev->bdev) - rdev->data_offset;
if (!num_sectors || num_sectors > max_sectors)
num_sectors = max_sectors;
} else if (rdev->mddev->bitmap_info.offset) {
/* minor version 0 with bitmap we can't move */
return 0;
} else {
/* minor version 0; superblock after data */
sector_t sb_start, bm_space;
sector_t dev_size = bdev_nr_sectors(rdev->bdev);
/* 8K is for superblock */
sb_start = dev_size - 8*2;
sb_start &= ~(sector_t)(4*2 - 1);
bm_space = super_1_choose_bm_space(dev_size);
/* Space that can be used to store date needs to decrease
* superblock bitmap space and bad block space(4K)
*/
max_sectors = sb_start - bm_space - 4*2;
if (!num_sectors || num_sectors > max_sectors)
num_sectors = max_sectors;
rdev->sb_start = sb_start;
}
sb = page_address(rdev->sb_page);
sb->data_size = cpu_to_le64(num_sectors);
sb->super_offset = cpu_to_le64(rdev->sb_start);
sb->sb_csum = calc_sb_1_csum(sb);
do {
md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
rdev->sb_page);
} while (md_super_wait(rdev->mddev) < 0);
return num_sectors;
}
static int
super_1_allow_new_offset(struct md_rdev *rdev,
unsigned long long new_offset)
{
/* All necessary checks on new >= old have been done */
struct bitmap *bitmap;
if (new_offset >= rdev->data_offset)
return 1;
/* with 1.0 metadata, there is no metadata to tread on
* so we can always move back */
if (rdev->mddev->minor_version == 0)
return 1;
/* otherwise we must be sure not to step on
* any metadata, so stay:
* 36K beyond start of superblock
* beyond end of badblocks
* beyond write-intent bitmap
*/
if (rdev->sb_start + (32+4)*2 > new_offset)
return 0;
bitmap = rdev->mddev->bitmap;
if (bitmap && !rdev->mddev->bitmap_info.file &&
rdev->sb_start + rdev->mddev->bitmap_info.offset +
bitmap->storage.file_pages * (PAGE_SIZE>>9) > new_offset)
return 0;
if (rdev->badblocks.sector + rdev->badblocks.size > new_offset)
return 0;
return 1;
}
static struct super_type super_types[] = {
[0] = {
.name = "0.90.0",
.owner = THIS_MODULE,
.load_super = super_90_load,
.validate_super = super_90_validate,
.sync_super = super_90_sync,
.rdev_size_change = super_90_rdev_size_change,
.allow_new_offset = super_90_allow_new_offset,
},
[1] = {
.name = "md-1",
.owner = THIS_MODULE,
.load_super = super_1_load,
.validate_super = super_1_validate,
.sync_super = super_1_sync,
.rdev_size_change = super_1_rdev_size_change,
.allow_new_offset = super_1_allow_new_offset,
},
};
static void sync_super(struct mddev *mddev, struct md_rdev *rdev)
{
if (mddev->sync_super) {
mddev->sync_super(mddev, rdev);
return;
}
BUG_ON(mddev->major_version >= ARRAY_SIZE(super_types));
super_types[mddev->major_version].sync_super(mddev, rdev);
}
static int match_mddev_units(struct mddev *mddev1, struct mddev *mddev2)
{
struct md_rdev *rdev, *rdev2;
rcu_read_lock();
rdev_for_each_rcu(rdev, mddev1) {
if (test_bit(Faulty, &rdev->flags) ||
test_bit(Journal, &rdev->flags) ||
rdev->raid_disk == -1)
continue;
rdev_for_each_rcu(rdev2, mddev2) {
if (test_bit(Faulty, &rdev2->flags) ||
test_bit(Journal, &rdev2->flags) ||
rdev2->raid_disk == -1)
continue;
if (rdev->bdev->bd_disk == rdev2->bdev->bd_disk) {
rcu_read_unlock();
return 1;
}
}
}
rcu_read_unlock();
return 0;
}
static LIST_HEAD(pending_raid_disks);
/*
* Try to register data integrity profile for an mddev
*
* This is called when an array is started and after a disk has been kicked
* from the array. It only succeeds if all working and active component devices
* are integrity capable with matching profiles.
*/
int md_integrity_register(struct mddev *mddev)
{
struct md_rdev *rdev, *reference = NULL;
if (list_empty(&mddev->disks))
return 0; /* nothing to do */
if (!mddev->gendisk || blk_get_integrity(mddev->gendisk))
return 0; /* shouldn't register, or already is */
rdev_for_each(rdev, mddev) {
/* skip spares and non-functional disks */
if (test_bit(Faulty, &rdev->flags))
continue;
if (rdev->raid_disk < 0)
continue;
if (!reference) {
/* Use the first rdev as the reference */
reference = rdev;
continue;
}
/* does this rdev's profile match the reference profile? */
if (blk_integrity_compare(reference->bdev->bd_disk,
rdev->bdev->bd_disk) < 0)
return -EINVAL;
}
if (!reference || !bdev_get_integrity(reference->bdev))
return 0;
/*
* All component devices are integrity capable and have matching
* profiles, register the common profile for the md device.
*/
blk_integrity_register(mddev->gendisk,
bdev_get_integrity(reference->bdev));
pr_debug("md: data integrity enabled on %s\n", mdname(mddev));
if (bioset_integrity_create(&mddev->bio_set, BIO_POOL_SIZE) ||
(mddev->level != 1 && mddev->level != 10 &&
bioset_integrity_create(&mddev->io_clone_set, BIO_POOL_SIZE))) {
/*
* No need to handle the failure of bioset_integrity_create,
* because the function is called by md_run() -> pers->run(),
* md_run calls bioset_exit -> bioset_integrity_free in case
* of failure case.
*/
pr_err("md: failed to create integrity pool for %s\n",
mdname(mddev));
return -EINVAL;
}
return 0;
}
EXPORT_SYMBOL(md_integrity_register);
/*
* Attempt to add an rdev, but only if it is consistent with the current
* integrity profile
*/
int md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev)
{
struct blk_integrity *bi_mddev;
if (!mddev->gendisk)
return 0;
bi_mddev = blk_get_integrity(mddev->gendisk);
if (!bi_mddev) /* nothing to do */
return 0;
if (blk_integrity_compare(mddev->gendisk, rdev->bdev->bd_disk) != 0) {
pr_err("%s: incompatible integrity profile for %pg\n",
mdname(mddev), rdev->bdev);
return -ENXIO;
}
return 0;
}
EXPORT_SYMBOL(md_integrity_add_rdev);
static bool rdev_read_only(struct md_rdev *rdev)
{
return bdev_read_only(rdev->bdev) ||
(rdev->meta_bdev && bdev_read_only(rdev->meta_bdev));
}
static int bind_rdev_to_array(struct md_rdev *rdev, struct mddev *mddev)
{
char b[BDEVNAME_SIZE];
int err;
/* prevent duplicates */
if (find_rdev(mddev, rdev->bdev->bd_dev))
return -EEXIST;
if (rdev_read_only(rdev) && mddev->pers)
return -EROFS;
/* make sure rdev->sectors exceeds mddev->dev_sectors */
if (!test_bit(Journal, &rdev->flags) &&
rdev->sectors &&
(mddev->dev_sectors == 0 || rdev->sectors < mddev->dev_sectors)) {
if (mddev->pers) {
/* Cannot change size, so fail
* If mddev->level <= 0, then we don't care
* about aligning sizes (e.g. linear)
*/
if (mddev->level > 0)
return -ENOSPC;
} else
mddev->dev_sectors = rdev->sectors;
}
/* Verify rdev->desc_nr is unique.
* If it is -1, assign a free number, else
* check number is not in use
*/
rcu_read_lock();
if (rdev->desc_nr < 0) {
int choice = 0;
if (mddev->pers)
choice = mddev->raid_disks;
while (md_find_rdev_nr_rcu(mddev, choice))
choice++;
rdev->desc_nr = choice;
} else {
if (md_find_rdev_nr_rcu(mddev, rdev->desc_nr)) {
rcu_read_unlock();
return -EBUSY;
}
}
rcu_read_unlock();
if (!test_bit(Journal, &rdev->flags) &&
mddev->max_disks && rdev->desc_nr >= mddev->max_disks) {
pr_warn("md: %s: array is limited to %d devices\n",
mdname(mddev), mddev->max_disks);
return -EBUSY;
}
snprintf(b, sizeof(b), "%pg", rdev->bdev);
strreplace(b, '/', '!');
rdev->mddev = mddev;
pr_debug("md: bind<%s>\n", b);
if (mddev->raid_disks)
mddev_create_serial_pool(mddev, rdev, false);
if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
goto fail;
/* failure here is OK */
err = sysfs_create_link(&rdev->kobj, bdev_kobj(rdev->bdev), "block");
rdev->sysfs_state = sysfs_get_dirent_safe(rdev->kobj.sd, "state");
rdev->sysfs_unack_badblocks =
sysfs_get_dirent_safe(rdev->kobj.sd, "unacknowledged_bad_blocks");
rdev->sysfs_badblocks =
sysfs_get_dirent_safe(rdev->kobj.sd, "bad_blocks");
list_add_rcu(&rdev->same_set, &mddev->disks);
bd_link_disk_holder(rdev->bdev, mddev->gendisk);
/* May as well allow recovery to be retried once */
mddev->recovery_disabled++;
return 0;
fail:
pr_warn("md: failed to register dev-%s for %s\n",
b, mdname(mddev));
return err;
}
void md_autodetect_dev(dev_t dev);
/* just for claiming the bdev */
static struct md_rdev claim_rdev;
static void export_rdev(struct md_rdev *rdev, struct mddev *mddev)
{
pr_debug("md: export_rdev(%pg)\n", rdev->bdev);
md_rdev_clear(rdev);
#ifndef MODULE
if (test_bit(AutoDetected, &rdev->flags))
md_autodetect_dev(rdev->bdev->bd_dev);
#endif
blkdev_put(rdev->bdev,
test_bit(Holder, &rdev->flags) ? rdev : &claim_rdev);
rdev->bdev = NULL;
kobject_put(&rdev->kobj);
}
static void md_kick_rdev_from_array(struct md_rdev *rdev)
{
struct mddev *mddev = rdev->mddev;
bd_unlink_disk_holder(rdev->bdev, rdev->mddev->gendisk);
list_del_rcu(&rdev->same_set);
pr_debug("md: unbind<%pg>\n", rdev->bdev);
mddev_destroy_serial_pool(rdev->mddev, rdev, false);
rdev->mddev = NULL;
sysfs_remove_link(&rdev->kobj, "block");
sysfs_put(rdev->sysfs_state);
sysfs_put(rdev->sysfs_unack_badblocks);
sysfs_put(rdev->sysfs_badblocks);
rdev->sysfs_state = NULL;
rdev->sysfs_unack_badblocks = NULL;
rdev->sysfs_badblocks = NULL;
rdev->badblocks.count = 0;
synchronize_rcu();
/*
* kobject_del() will wait for all in progress writers to be done, where
* reconfig_mutex is held, hence it can't be called under
* reconfig_mutex and it's delayed to mddev_unlock().
*/
list_add(&rdev->same_set, &mddev->deleting);
}
static void export_array(struct mddev *mddev)
{
struct md_rdev *rdev;
while (!list_empty(&mddev->disks)) {
rdev = list_first_entry(&mddev->disks, struct md_rdev,
same_set);
md_kick_rdev_from_array(rdev);
}
mddev->raid_disks = 0;
mddev->major_version = 0;
}
static bool set_in_sync(struct mddev *mddev)
{
lockdep_assert_held(&mddev->lock);
if (!mddev->in_sync) {
mddev->sync_checkers++;
spin_unlock(&mddev->lock);
percpu_ref_switch_to_atomic_sync(&mddev->writes_pending);
spin_lock(&mddev->lock);
if (!mddev->in_sync &&
percpu_ref_is_zero(&mddev->writes_pending)) {
mddev->in_sync = 1;
/*
* Ensure ->in_sync is visible before we clear
* ->sync_checkers.
*/
smp_mb();
set_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
sysfs_notify_dirent_safe(mddev->sysfs_state);
}
if (--mddev->sync_checkers == 0)
percpu_ref_switch_to_percpu(&mddev->writes_pending);
}
if (mddev->safemode == 1)
mddev->safemode = 0;
return mddev->in_sync;
}
static void sync_sbs(struct mddev *mddev, int nospares)
{
/* Update each superblock (in-memory image), but
* if we are allowed to, skip spares which already
* have the right event counter, or have one earlier
* (which would mean they aren't being marked as dirty
* with the rest of the array)
*/
struct md_rdev *rdev;
rdev_for_each(rdev, mddev) {
if (rdev->sb_events == mddev->events ||
(nospares &&
rdev->raid_disk < 0 &&
rdev->sb_events+1 == mddev->events)) {
/* Don't update this superblock */
rdev->sb_loaded = 2;
} else {
sync_super(mddev, rdev);
rdev->sb_loaded = 1;
}
}
}
static bool does_sb_need_changing(struct mddev *mddev)
{
struct md_rdev *rdev = NULL, *iter;
struct mdp_superblock_1 *sb;
int role;
/* Find a good rdev */
rdev_for_each(iter, mddev)
if ((iter->raid_disk >= 0) && !test_bit(Faulty, &iter->flags)) {
rdev = iter;
break;
}
/* No good device found. */
if (!rdev)
return false;
sb = page_address(rdev->sb_page);
/* Check if a device has become faulty or a spare become active */
rdev_for_each(rdev, mddev) {
role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
/* Device activated? */
if (role == MD_DISK_ROLE_SPARE && rdev->raid_disk >= 0 &&
!test_bit(Faulty, &rdev->flags))
return true;
/* Device turned faulty? */
if (test_bit(Faulty, &rdev->flags) && (role < MD_DISK_ROLE_MAX))
return true;
}
/* Check if any mddev parameters have changed */
if ((mddev->dev_sectors != le64_to_cpu(sb->size)) ||
(mddev->reshape_position != le64_to_cpu(sb->reshape_position)) ||
(mddev->layout != le32_to_cpu(sb->layout)) ||
(mddev->raid_disks != le32_to_cpu(sb->raid_disks)) ||
(mddev->chunk_sectors != le32_to_cpu(sb->chunksize)))
return true;
return false;
}
void md_update_sb(struct mddev *mddev, int force_change)
{
struct md_rdev *rdev;
int sync_req;
int nospares = 0;
int any_badblocks_changed = 0;
int ret = -1;
if (!md_is_rdwr(mddev)) {
if (force_change)
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
return;
}
repeat:
if (mddev_is_clustered(mddev)) {
if (test_and_clear_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags))
force_change = 1;
if (test_and_clear_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags))
nospares = 1;
ret = md_cluster_ops->metadata_update_start(mddev);
/* Has someone else has updated the sb */
if (!does_sb_need_changing(mddev)) {
if (ret == 0)
md_cluster_ops->metadata_update_cancel(mddev);
bit_clear_unless(&mddev->sb_flags, BIT(MD_SB_CHANGE_PENDING),
BIT(MD_SB_CHANGE_DEVS) |
BIT(MD_SB_CHANGE_CLEAN));
return;
}
}
/*
* First make sure individual recovery_offsets are correct
* curr_resync_completed can only be used during recovery.
* During reshape/resync it might use array-addresses rather
* that device addresses.
*/
rdev_for_each(rdev, mddev) {
if (rdev->raid_disk >= 0 &&
mddev->delta_disks >= 0 &&
test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
test_bit(MD_RECOVERY_RECOVER, &mddev->recovery) &&
!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
!test_bit(Journal, &rdev->flags) &&
!test_bit(In_sync, &rdev->flags) &&
mddev->curr_resync_completed > rdev->recovery_offset)
rdev->recovery_offset = mddev->curr_resync_completed;
}
if (!mddev->persistent) {
clear_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
clear_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
if (!mddev->external) {
clear_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags);
rdev_for_each(rdev, mddev) {
if (rdev->badblocks.changed) {
rdev->badblocks.changed = 0;
ack_all_badblocks(&rdev->badblocks);
md_error(mddev, rdev);
}
clear_bit(Blocked, &rdev->flags);
clear_bit(BlockedBadBlocks, &rdev->flags);
wake_up(&rdev->blocked_wait);
}
}
wake_up(&mddev->sb_wait);
return;
}
spin_lock(&mddev->lock);
mddev->utime = ktime_get_real_seconds();
if (test_and_clear_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags))
force_change = 1;
if (test_and_clear_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags))
/* just a clean<-> dirty transition, possibly leave spares alone,
* though if events isn't the right even/odd, we will have to do
* spares after all
*/
nospares = 1;
if (force_change)
nospares = 0;
if (mddev->degraded)
/* If the array is degraded, then skipping spares is both
* dangerous and fairly pointless.
* Dangerous because a device that was removed from the array
* might have a event_count that still looks up-to-date,
* so it can be re-added without a resync.
* Pointless because if there are any spares to skip,
* then a recovery will happen and soon that array won't
* be degraded any more and the spare can go back to sleep then.
*/
nospares = 0;
sync_req = mddev->in_sync;
/* If this is just a dirty<->clean transition, and the array is clean
* and 'events' is odd, we can roll back to the previous clean state */
if (nospares
&& (mddev->in_sync && mddev->recovery_cp == MaxSector)
&& mddev->can_decrease_events
&& mddev->events != 1) {
mddev->events--;
mddev->can_decrease_events = 0;
} else {
/* otherwise we have to go forward and ... */
mddev->events ++;
mddev->can_decrease_events = nospares;
}
/*
* This 64-bit counter should never wrap.
* Either we are in around ~1 trillion A.C., assuming
* 1 reboot per second, or we have a bug...
*/
WARN_ON(mddev->events == 0);
rdev_for_each(rdev, mddev) {
if (rdev->badblocks.changed)
any_badblocks_changed++;
if (test_bit(Faulty, &rdev->flags))
set_bit(FaultRecorded, &rdev->flags);
}
sync_sbs(mddev, nospares);
spin_unlock(&mddev->lock);
pr_debug("md: updating %s RAID superblock on device (in sync %d)\n",
mdname(mddev), mddev->in_sync);
if (mddev->queue)
blk_add_trace_msg(mddev->queue, "md md_update_sb");
rewrite:
md_bitmap_update_sb(mddev->bitmap);
rdev_for_each(rdev, mddev) {
if (rdev->sb_loaded != 1)
continue; /* no noise on spare devices */
if (!test_bit(Faulty, &rdev->flags)) {
md_super_write(mddev,rdev,
rdev->sb_start, rdev->sb_size,
rdev->sb_page);
pr_debug("md: (write) %pg's sb offset: %llu\n",
rdev->bdev,
(unsigned long long)rdev->sb_start);
rdev->sb_events = mddev->events;
if (rdev->badblocks.size) {
md_super_write(mddev, rdev,
rdev->badblocks.sector,
rdev->badblocks.size << 9,
rdev->bb_page);
rdev->badblocks.size = 0;
}
} else
pr_debug("md: %pg (skipping faulty)\n",
rdev->bdev);
if (mddev->level == LEVEL_MULTIPATH)
/* only need to write one superblock... */
break;
}
if (md_super_wait(mddev) < 0)
goto rewrite;
/* if there was a failure, MD_SB_CHANGE_DEVS was set, and we re-write super */
if (mddev_is_clustered(mddev) && ret == 0)
md_cluster_ops->metadata_update_finish(mddev);
if (mddev->in_sync != sync_req ||
!bit_clear_unless(&mddev->sb_flags, BIT(MD_SB_CHANGE_PENDING),
BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_CLEAN)))
/* have to write it out again */
goto repeat;
wake_up(&mddev->sb_wait);
if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
sysfs_notify_dirent_safe(mddev->sysfs_completed);
rdev_for_each(rdev, mddev) {
if (test_and_clear_bit(FaultRecorded, &rdev->flags))
clear_bit(Blocked, &rdev->flags);
if (any_badblocks_changed)
ack_all_badblocks(&rdev->badblocks);
clear_bit(BlockedBadBlocks, &rdev->flags);
wake_up(&rdev->blocked_wait);
}
}
EXPORT_SYMBOL(md_update_sb);
static int add_bound_rdev(struct md_rdev *rdev)
{
struct mddev *mddev = rdev->mddev;
int err = 0;
bool add_journal = test_bit(Journal, &rdev->flags);
if (!mddev->pers->hot_remove_disk || add_journal) {
/* If there is hot_add_disk but no hot_remove_disk
* then added disks for geometry changes,
* and should be added immediately.
*/
super_types[mddev->major_version].
validate_super(mddev, rdev);
if (add_journal)
mddev_suspend(mddev);
err = mddev->pers->hot_add_disk(mddev, rdev);
if (add_journal)
mddev_resume(mddev);
if (err) {
md_kick_rdev_from_array(rdev);
return err;
}
}
sysfs_notify_dirent_safe(rdev->sysfs_state);
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
if (mddev->degraded)
set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_new_event();
md_wakeup_thread(mddev->thread);
return 0;
}
/* words written to sysfs files may, or may not, be \n terminated.
* We want to accept with case. For this we use cmd_match.
*/
static int cmd_match(const char *cmd, const char *str)
{
/* See if cmd, written into a sysfs file, matches
* str. They must either be the same, or cmd can
* have a trailing newline
*/
while (*cmd && *str && *cmd == *str) {
cmd++;
str++;
}
if (*cmd == '\n')
cmd++;
if (*str || *cmd)
return 0;
return 1;
}
struct rdev_sysfs_entry {
struct attribute attr;
ssize_t (*show)(struct md_rdev *, char *);
ssize_t (*store)(struct md_rdev *, const char *, size_t);
};
static ssize_t
state_show(struct md_rdev *rdev, char *page)
{
char *sep = ",";
size_t len = 0;
unsigned long flags = READ_ONCE(rdev->flags);
if (test_bit(Faulty, &flags) ||
(!test_bit(ExternalBbl, &flags) &&
rdev->badblocks.unacked_exist))
len += sprintf(page+len, "faulty%s", sep);
if (test_bit(In_sync, &flags))
len += sprintf(page+len, "in_sync%s", sep);
if (test_bit(Journal, &flags))
len += sprintf(page+len, "journal%s", sep);
if (test_bit(WriteMostly, &flags))
len += sprintf(page+len, "write_mostly%s", sep);
if (test_bit(Blocked, &flags) ||
(rdev->badblocks.unacked_exist
&& !test_bit(Faulty, &flags)))
len += sprintf(page+len, "blocked%s", sep);
if (!test_bit(Faulty, &flags) &&
!test_bit(Journal, &flags) &&
!test_bit(In_sync, &flags))
len += sprintf(page+len, "spare%s", sep);
if (test_bit(WriteErrorSeen, &flags))
len += sprintf(page+len, "write_error%s", sep);
if (test_bit(WantReplacement, &flags))
len += sprintf(page+len, "want_replacement%s", sep);
if (test_bit(Replacement, &flags))
len += sprintf(page+len, "replacement%s", sep);
if (test_bit(ExternalBbl, &flags))
len += sprintf(page+len, "external_bbl%s", sep);
if (test_bit(FailFast, &flags))
len += sprintf(page+len, "failfast%s", sep);
if (len)
len -= strlen(sep);
return len+sprintf(page+len, "\n");
}
static ssize_t
state_store(struct md_rdev *rdev, const char *buf, size_t len)
{
/* can write
* faulty - simulates an error
* remove - disconnects the device
* writemostly - sets write_mostly
* -writemostly - clears write_mostly
* blocked - sets the Blocked flags
* -blocked - clears the Blocked and possibly simulates an error
* insync - sets Insync providing device isn't active
* -insync - clear Insync for a device with a slot assigned,
* so that it gets rebuilt based on bitmap
* write_error - sets WriteErrorSeen
* -write_error - clears WriteErrorSeen
* {,-}failfast - set/clear FailFast
*/
struct mddev *mddev = rdev->mddev;
int err = -EINVAL;
bool need_update_sb = false;
if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
md_error(rdev->mddev, rdev);
if (test_bit(MD_BROKEN, &rdev->mddev->flags))
err = -EBUSY;
else
err = 0;
} else if (cmd_match(buf, "remove")) {
if (rdev->mddev->pers) {
clear_bit(Blocked, &rdev->flags);
remove_and_add_spares(rdev->mddev, rdev);
}
if (rdev->raid_disk >= 0)
err = -EBUSY;
else {
err = 0;
if (mddev_is_clustered(mddev))
err = md_cluster_ops->remove_disk(mddev, rdev);
if (err == 0) {
md_kick_rdev_from_array(rdev);
if (mddev->pers) {
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
md_wakeup_thread(mddev->thread);
}
md_new_event();
}
}
} else if (cmd_match(buf, "writemostly")) {
set_bit(WriteMostly, &rdev->flags);
mddev_create_serial_pool(rdev->mddev, rdev, false);
need_update_sb = true;
err = 0;
} else if (cmd_match(buf, "-writemostly")) {
mddev_destroy_serial_pool(rdev->mddev, rdev, false);
clear_bit(WriteMostly, &rdev->flags);
need_update_sb = true;
err = 0;
} else if (cmd_match(buf, "blocked")) {
set_bit(Blocked, &rdev->flags);
err = 0;
} else if (cmd_match(buf, "-blocked")) {
if (!test_bit(Faulty, &rdev->flags) &&
!test_bit(ExternalBbl, &rdev->flags) &&
rdev->badblocks.unacked_exist) {
/* metadata handler doesn't understand badblocks,
* so we need to fail the device
*/
md_error(rdev->mddev, rdev);
}
clear_bit(Blocked, &rdev->flags);
clear_bit(BlockedBadBlocks, &rdev->flags);
wake_up(&rdev->blocked_wait);
set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
md_wakeup_thread(rdev->mddev->thread);
err = 0;
} else if (cmd_match(buf, "insync") && rdev->raid_disk == -1) {
set_bit(In_sync, &rdev->flags);
err = 0;
} else if (cmd_match(buf, "failfast")) {
set_bit(FailFast, &rdev->flags);
need_update_sb = true;
err = 0;
} else if (cmd_match(buf, "-failfast")) {
clear_bit(FailFast, &rdev->flags);
need_update_sb = true;
err = 0;
} else if (cmd_match(buf, "-insync") && rdev->raid_disk >= 0 &&
!test_bit(Journal, &rdev->flags)) {
if (rdev->mddev->pers == NULL) {
clear_bit(In_sync, &rdev->flags);
rdev->saved_raid_disk = rdev->raid_disk;
rdev->raid_disk = -1;
err = 0;
}
} else if (cmd_match(buf, "write_error")) {
set_bit(WriteErrorSeen, &rdev->flags);
err = 0;
} else if (cmd_match(buf, "-write_error")) {
clear_bit(WriteErrorSeen, &rdev->flags);
err = 0;
} else if (cmd_match(buf, "want_replacement")) {
/* Any non-spare device that is not a replacement can
* become want_replacement at any time, but we then need to
* check if recovery is needed.
*/
if (rdev->raid_disk >= 0 &&
!test_bit(Journal, &rdev->flags) &&
!test_bit(Replacement, &rdev->flags))
set_bit(WantReplacement, &rdev->flags);
set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
md_wakeup_thread(rdev->mddev->thread);
err = 0;
} else if (cmd_match(buf, "-want_replacement")) {
/* Clearing 'want_replacement' is always allowed.
* Once replacements starts it is too late though.
*/
err = 0;
clear_bit(WantReplacement, &rdev->flags);
} else if (cmd_match(buf, "replacement")) {
/* Can only set a device as a replacement when array has not
* yet been started. Once running, replacement is automatic
* from spares, or by assigning 'slot'.
*/
if (rdev->mddev->pers)
err = -EBUSY;
else {
set_bit(Replacement, &rdev->flags);
err = 0;
}
} else if (cmd_match(buf, "-replacement")) {
/* Similarly, can only clear Replacement before start */
if (rdev->mddev->pers)
err = -EBUSY;
else {
clear_bit(Replacement, &rdev->flags);
err = 0;
}
} else if (cmd_match(buf, "re-add")) {
if (!rdev->mddev->pers)
err = -EINVAL;
else if (test_bit(Faulty, &rdev->flags) && (rdev->raid_disk == -1) &&
rdev->saved_raid_disk >= 0) {
/* clear_bit is performed _after_ all the devices
* have their local Faulty bit cleared. If any writes
* happen in the meantime in the local node, they
* will land in the local bitmap, which will be synced
* by this node eventually
*/
if (!mddev_is_clustered(rdev->mddev) ||
(err = md_cluster_ops->gather_bitmaps(rdev)) == 0) {
clear_bit(Faulty, &rdev->flags);
err = add_bound_rdev(rdev);
}
} else
err = -EBUSY;
} else if (cmd_match(buf, "external_bbl") && (rdev->mddev->external)) {
set_bit(ExternalBbl, &rdev->flags);
rdev->badblocks.shift = 0;
err = 0;
} else if (cmd_match(buf, "-external_bbl") && (rdev->mddev->external)) {
clear_bit(ExternalBbl, &rdev->flags);
err = 0;
}
if (need_update_sb)
md_update_sb(mddev, 1);
if (!err)
sysfs_notify_dirent_safe(rdev->sysfs_state);
return err ? err : len;
}
static struct rdev_sysfs_entry rdev_state =
__ATTR_PREALLOC(state, S_IRUGO|S_IWUSR, state_show, state_store);
static ssize_t
errors_show(struct md_rdev *rdev, char *page)
{
return sprintf(page, "%d\n", atomic_read(&rdev->corrected_errors));
}
static ssize_t
errors_store(struct md_rdev *rdev, const char *buf, size_t len)
{
unsigned int n;
int rv;
rv = kstrtouint(buf, 10, &n);
if (rv < 0)
return rv;
atomic_set(&rdev->corrected_errors, n);
return len;
}
static struct rdev_sysfs_entry rdev_errors =
__ATTR(errors, S_IRUGO|S_IWUSR, errors_show, errors_store);
static ssize_t
slot_show(struct md_rdev *rdev, char *page)
{
if (test_bit(Journal, &rdev->flags))
return sprintf(page, "journal\n");
else if (rdev->raid_disk < 0)
return sprintf(page, "none\n");
else
return sprintf(page, "%d\n", rdev->raid_disk);
}
static ssize_t
slot_store(struct md_rdev *rdev, const char *buf, size_t len)
{
int slot;
int err;
if (test_bit(Journal, &rdev->flags))
return -EBUSY;
if (strncmp(buf, "none", 4)==0)
slot = -1;
else {
err = kstrtouint(buf, 10, (unsigned int *)&slot);
if (err < 0)
return err;
if (slot < 0)
/* overflow */
return -ENOSPC;
}
if (rdev->mddev->pers && slot == -1) {
/* Setting 'slot' on an active array requires also
* updating the 'rd%d' link, and communicating
* with the personality with ->hot_*_disk.
* For now we only support removing
* failed/spare devices. This normally happens automatically,
* but not when the metadata is externally managed.
*/
if (rdev->raid_disk == -1)
return -EEXIST;
/* personality does all needed checks */
if (rdev->mddev->pers->hot_remove_disk == NULL)
return -EINVAL;
clear_bit(Blocked, &rdev->flags);
remove_and_add_spares(rdev->mddev, rdev);
if (rdev->raid_disk >= 0)
return -EBUSY;
set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
md_wakeup_thread(rdev->mddev->thread);
} else if (rdev->mddev->pers) {
/* Activating a spare .. or possibly reactivating
* if we ever get bitmaps working here.
*/
int err;
if (rdev->raid_disk != -1)
return -EBUSY;
if (test_bit(MD_RECOVERY_RUNNING, &rdev->mddev->recovery))
return -EBUSY;
if (rdev->mddev->pers->hot_add_disk == NULL)
return -EINVAL;
if (slot >= rdev->mddev->raid_disks &&
slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
return -ENOSPC;
rdev->raid_disk = slot;
if (test_bit(In_sync, &rdev->flags))
rdev->saved_raid_disk = slot;
else
rdev->saved_raid_disk = -1;
clear_bit(In_sync, &rdev->flags);
clear_bit(Bitmap_sync, &rdev->flags);
err = rdev->mddev->pers->hot_add_disk(rdev->mddev, rdev);
if (err) {
rdev->raid_disk = -1;
return err;
} else
sysfs_notify_dirent_safe(rdev->sysfs_state);
/* failure here is OK */;
sysfs_link_rdev(rdev->mddev, rdev);
/* don't wakeup anyone, leave that to userspace. */
} else {
if (slot >= rdev->mddev->raid_disks &&
slot >= rdev->mddev->raid_disks + rdev->mddev->delta_disks)
return -ENOSPC;
rdev->raid_disk = slot;
/* assume it is working */
clear_bit(Faulty, &rdev->flags);
clear_bit(WriteMostly, &rdev->flags);
set_bit(In_sync, &rdev->flags);
sysfs_notify_dirent_safe(rdev->sysfs_state);
}
return len;
}
static struct rdev_sysfs_entry rdev_slot =
__ATTR(slot, S_IRUGO|S_IWUSR, slot_show, slot_store);
static ssize_t
offset_show(struct md_rdev *rdev, char *page)
{
return sprintf(page, "%llu\n", (unsigned long long)rdev->data_offset);
}
static ssize_t
offset_store(struct md_rdev *rdev, const char *buf, size_t len)
{
unsigned long long offset;
if (kstrtoull(buf, 10, &offset) < 0)
return -EINVAL;
if (rdev->mddev->pers && rdev->raid_disk >= 0)
return -EBUSY;
if (rdev->sectors && rdev->mddev->external)
/* Must set offset before size, so overlap checks
* can be sane */
return -EBUSY;
rdev->data_offset = offset;
rdev->new_data_offset = offset;
return len;
}
static struct rdev_sysfs_entry rdev_offset =
__ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
static ssize_t new_offset_show(struct md_rdev *rdev, char *page)
{
return sprintf(page, "%llu\n",
(unsigned long long)rdev->new_data_offset);
}
static ssize_t new_offset_store(struct md_rdev *rdev,
const char *buf, size_t len)
{
unsigned long long new_offset;
struct mddev *mddev = rdev->mddev;
if (kstrtoull(buf, 10, &new_offset) < 0)
return -EINVAL;
if (mddev->sync_thread ||
test_bit(MD_RECOVERY_RUNNING,&mddev->recovery))
return -EBUSY;
if (new_offset == rdev->data_offset)
/* reset is always permitted */
;
else if (new_offset > rdev->data_offset) {
/* must not push array size beyond rdev_sectors */
if (new_offset - rdev->data_offset
+ mddev->dev_sectors > rdev->sectors)
return -E2BIG;
}
/* Metadata worries about other space details. */
/* decreasing the offset is inconsistent with a backwards
* reshape.
*/
if (new_offset < rdev->data_offset &&
mddev->reshape_backwards)
return -EINVAL;
/* Increasing offset is inconsistent with forwards
* reshape. reshape_direction should be set to
* 'backwards' first.
*/
if (new_offset > rdev->data_offset &&
!mddev->reshape_backwards)
return -EINVAL;
if (mddev->pers && mddev->persistent &&
!super_types[mddev->major_version]
.allow_new_offset(rdev, new_offset))
return -E2BIG;
rdev->new_data_offset = new_offset;
if (new_offset > rdev->data_offset)
mddev->reshape_backwards = 1;
else if (new_offset < rdev->data_offset)
mddev->reshape_backwards = 0;
return len;
}
static struct rdev_sysfs_entry rdev_new_offset =
__ATTR(new_offset, S_IRUGO|S_IWUSR, new_offset_show, new_offset_store);
static ssize_t
rdev_size_show(struct md_rdev *rdev, char *page)
{
return sprintf(page, "%llu\n", (unsigned long long)rdev->sectors / 2);
}
static int md_rdevs_overlap(struct md_rdev *a, struct md_rdev *b)
{
/* check if two start/length pairs overlap */
if (a->data_offset + a->sectors <= b->data_offset)
return false;
if (b->data_offset + b->sectors <= a->data_offset)
return false;
return true;
}
static bool md_rdev_overlaps(struct md_rdev *rdev)
{
struct mddev *mddev;
struct md_rdev *rdev2;
spin_lock(&all_mddevs_lock);
list_for_each_entry(mddev, &all_mddevs, all_mddevs) {
if (test_bit(MD_DELETED, &mddev->flags))
continue;
rdev_for_each(rdev2, mddev) {
if (rdev != rdev2 && rdev->bdev == rdev2->bdev &&
md_rdevs_overlap(rdev, rdev2)) {
spin_unlock(&all_mddevs_lock);
return true;
}
}
}
spin_unlock(&all_mddevs_lock);
return false;
}
static int strict_blocks_to_sectors(const char *buf, sector_t *sectors)
{
unsigned long long blocks;
sector_t new;
if (kstrtoull(buf, 10, &blocks) < 0)
return -EINVAL;
if (blocks & 1ULL << (8 * sizeof(blocks) - 1))
return -EINVAL; /* sector conversion overflow */
new = blocks * 2;
if (new != blocks * 2)
return -EINVAL; /* unsigned long long to sector_t overflow */
*sectors = new;
return 0;
}
static ssize_t
rdev_size_store(struct md_rdev *rdev, const char *buf, size_t len)
{
struct mddev *my_mddev = rdev->mddev;
sector_t oldsectors = rdev->sectors;
sector_t sectors;
if (test_bit(Journal, &rdev->flags))
return -EBUSY;
if (strict_blocks_to_sectors(buf, §ors) < 0)
return -EINVAL;
if (rdev->data_offset != rdev->new_data_offset)
return -EINVAL; /* too confusing */
if (my_mddev->pers && rdev->raid_disk >= 0) {
if (my_mddev->persistent) {
sectors = super_types[my_mddev->major_version].
rdev_size_change(rdev, sectors);
if (!sectors)
return -EBUSY;
} else if (!sectors)
sectors = bdev_nr_sectors(rdev->bdev) -
rdev->data_offset;
if (!my_mddev->pers->resize)
/* Cannot change size for RAID0 or Linear etc */
return -EINVAL;
}
if (sectors < my_mddev->dev_sectors)
return -EINVAL; /* component must fit device */
rdev->sectors = sectors;
/*
* Check that all other rdevs with the same bdev do not overlap. This
* check does not provide a hard guarantee, it just helps avoid
* dangerous mistakes.
*/
if (sectors > oldsectors && my_mddev->external &&
md_rdev_overlaps(rdev)) {
/*
* Someone else could have slipped in a size change here, but
* doing so is just silly. We put oldsectors back because we
* know it is safe, and trust userspace not to race with itself.
*/
rdev->sectors = oldsectors;
return -EBUSY;
}
return len;
}
static struct rdev_sysfs_entry rdev_size =
__ATTR(size, S_IRUGO|S_IWUSR, rdev_size_show, rdev_size_store);
static ssize_t recovery_start_show(struct md_rdev *rdev, char *page)
{
unsigned long long recovery_start = rdev->recovery_offset;
if (test_bit(In_sync, &rdev->flags) ||
recovery_start == MaxSector)
return sprintf(page, "none\n");
return sprintf(page, "%llu\n", recovery_start);
}
static ssize_t recovery_start_store(struct md_rdev *rdev, const char *buf, size_t len)
{
unsigned long long recovery_start;
if (cmd_match(buf, "none"))
recovery_start = MaxSector;
else if (kstrtoull(buf, 10, &recovery_start))
return -EINVAL;
if (rdev->mddev->pers &&
rdev->raid_disk >= 0)
return -EBUSY;
rdev->recovery_offset = recovery_start;
if (recovery_start == MaxSector)
set_bit(In_sync, &rdev->flags);
else
clear_bit(In_sync, &rdev->flags);
return len;
}
static struct rdev_sysfs_entry rdev_recovery_start =
__ATTR(recovery_start, S_IRUGO|S_IWUSR, recovery_start_show, recovery_start_store);
/* sysfs access to bad-blocks list.
* We present two files.
* 'bad-blocks' lists sector numbers and lengths of ranges that
* are recorded as bad. The list is truncated to fit within
* the one-page limit of sysfs.
* Writing "sector length" to this file adds an acknowledged
* bad block list.
* 'unacknowledged-bad-blocks' lists bad blocks that have not yet
* been acknowledged. Writing to this file adds bad blocks
* without acknowledging them. This is largely for testing.
*/
static ssize_t bb_show(struct md_rdev *rdev, char *page)
{
return badblocks_show(&rdev->badblocks, page, 0);
}
static ssize_t bb_store(struct md_rdev *rdev, const char *page, size_t len)
{
int rv = badblocks_store(&rdev->badblocks, page, len, 0);
/* Maybe that ack was all we needed */
if (test_and_clear_bit(BlockedBadBlocks, &rdev->flags))
wake_up(&rdev->blocked_wait);
return rv;
}
static struct rdev_sysfs_entry rdev_bad_blocks =
__ATTR(bad_blocks, S_IRUGO|S_IWUSR, bb_show, bb_store);
static ssize_t ubb_show(struct md_rdev *rdev, char *page)
{
return badblocks_show(&rdev->badblocks, page, 1);
}
static ssize_t ubb_store(struct md_rdev *rdev, const char *page, size_t len)
{
return badblocks_store(&rdev->badblocks, page, len, 1);
}
static struct rdev_sysfs_entry rdev_unack_bad_blocks =
__ATTR(unacknowledged_bad_blocks, S_IRUGO|S_IWUSR, ubb_show, ubb_store);
static ssize_t
ppl_sector_show(struct md_rdev *rdev, char *page)
{
return sprintf(page, "%llu\n", (unsigned long long)rdev->ppl.sector);
}
static ssize_t
ppl_sector_store(struct md_rdev *rdev, const char *buf, size_t len)
{
unsigned long long sector;
if (kstrtoull(buf, 10, §or) < 0)
return -EINVAL;
if (sector != (sector_t)sector)
return -EINVAL;
if (rdev->mddev->pers && test_bit(MD_HAS_PPL, &rdev->mddev->flags) &&
rdev->raid_disk >= 0)
return -EBUSY;
if (rdev->mddev->persistent) {
if (rdev->mddev->major_version == 0)
return -EINVAL;
if ((sector > rdev->sb_start &&
sector - rdev->sb_start > S16_MAX) ||
(sector < rdev->sb_start &&
rdev->sb_start - sector > -S16_MIN))
return -EINVAL;
rdev->ppl.offset = sector - rdev->sb_start;
} else if (!rdev->mddev->external) {
return -EBUSY;
}
rdev->ppl.sector = sector;
return len;
}
static struct rdev_sysfs_entry rdev_ppl_sector =
__ATTR(ppl_sector, S_IRUGO|S_IWUSR, ppl_sector_show, ppl_sector_store);
static ssize_t
ppl_size_show(struct md_rdev *rdev, char *page)
{
return sprintf(page, "%u\n", rdev->ppl.size);
}
static ssize_t
ppl_size_store(struct md_rdev *rdev, const char *buf, size_t len)
{
unsigned int size;
if (kstrtouint(buf, 10, &size) < 0)
return -EINVAL;
if (rdev->mddev->pers && test_bit(MD_HAS_PPL, &rdev->mddev->flags) &&
rdev->raid_disk >= 0)
return -EBUSY;
if (rdev->mddev->persistent) {
if (rdev->mddev->major_version == 0)
return -EINVAL;
if (size > U16_MAX)
return -EINVAL;
} else if (!rdev->mddev->external) {
return -EBUSY;
}
rdev->ppl.size = size;
return len;
}
static struct rdev_sysfs_entry rdev_ppl_size =
__ATTR(ppl_size, S_IRUGO|S_IWUSR, ppl_size_show, ppl_size_store);
static struct attribute *rdev_default_attrs[] = {
&rdev_state.attr,
&rdev_errors.attr,
&rdev_slot.attr,
&rdev_offset.attr,
&rdev_new_offset.attr,
&rdev_size.attr,
&rdev_recovery_start.attr,
&rdev_bad_blocks.attr,
&rdev_unack_bad_blocks.attr,
&rdev_ppl_sector.attr,
&rdev_ppl_size.attr,
NULL,
};
ATTRIBUTE_GROUPS(rdev_default);
static ssize_t
rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
{
struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
if (!entry->show)
return -EIO;
if (!rdev->mddev)
return -ENODEV;
return entry->show(rdev, page);
}
static ssize_t
rdev_attr_store(struct kobject *kobj, struct attribute *attr,
const char *page, size_t length)
{
struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
struct kernfs_node *kn = NULL;
ssize_t rv;
struct mddev *mddev = rdev->mddev;
if (!entry->store)
return -EIO;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (entry->store == state_store && cmd_match(page, "remove"))
kn = sysfs_break_active_protection(kobj, attr);
rv = mddev ? mddev_lock(mddev) : -ENODEV;
if (!rv) {
if (rdev->mddev == NULL)
rv = -ENODEV;
else
rv = entry->store(rdev, page, length);
mddev_unlock(mddev);
}
if (kn)
sysfs_unbreak_active_protection(kn);
return rv;
}
static void rdev_free(struct kobject *ko)
{
struct md_rdev *rdev = container_of(ko, struct md_rdev, kobj);
kfree(rdev);
}
static const struct sysfs_ops rdev_sysfs_ops = {
.show = rdev_attr_show,
.store = rdev_attr_store,
};
static const struct kobj_type rdev_ktype = {
.release = rdev_free,
.sysfs_ops = &rdev_sysfs_ops,
.default_groups = rdev_default_groups,
};
int md_rdev_init(struct md_rdev *rdev)
{
rdev->desc_nr = -1;
rdev->saved_raid_disk = -1;
rdev->raid_disk = -1;
rdev->flags = 0;
rdev->data_offset = 0;
rdev->new_data_offset = 0;
rdev->sb_events = 0;
rdev->last_read_error = 0;
rdev->sb_loaded = 0;
rdev->bb_page = NULL;
atomic_set(&rdev->nr_pending, 0);
atomic_set(&rdev->read_errors, 0);
atomic_set(&rdev->corrected_errors, 0);
INIT_LIST_HEAD(&rdev->same_set);
init_waitqueue_head(&rdev->blocked_wait);
/* Add space to store bad block list.
* This reserves the space even on arrays where it cannot
* be used - I wonder if that matters
*/
return badblocks_init(&rdev->badblocks, 0);
}
EXPORT_SYMBOL_GPL(md_rdev_init);
/*
* Import a device. If 'super_format' >= 0, then sanity check the superblock
*
* mark the device faulty if:
*
* - the device is nonexistent (zero size)
* - the device has no valid superblock
*
* a faulty rdev _never_ has rdev->sb set.
*/
static struct md_rdev *md_import_device(dev_t newdev, int super_format, int super_minor)
{
struct md_rdev *rdev;
struct md_rdev *holder;
sector_t size;
int err;
rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
if (!rdev)
return ERR_PTR(-ENOMEM);
err = md_rdev_init(rdev);
if (err)
goto out_free_rdev;
err = alloc_disk_sb(rdev);
if (err)
goto out_clear_rdev;
if (super_format == -2) {
holder = &claim_rdev;
} else {
holder = rdev;
set_bit(Holder, &rdev->flags);
}
rdev->bdev = blkdev_get_by_dev(newdev, BLK_OPEN_READ | BLK_OPEN_WRITE,
holder, NULL);
if (IS_ERR(rdev->bdev)) {
pr_warn("md: could not open device unknown-block(%u,%u).\n",
MAJOR(newdev), MINOR(newdev));
err = PTR_ERR(rdev->bdev);
goto out_clear_rdev;
}
kobject_init(&rdev->kobj, &rdev_ktype);
size = bdev_nr_bytes(rdev->bdev) >> BLOCK_SIZE_BITS;
if (!size) {
pr_warn("md: %pg has zero or unknown size, marking faulty!\n",
rdev->bdev);
err = -EINVAL;
goto out_blkdev_put;
}
if (super_format >= 0) {
err = super_types[super_format].
load_super(rdev, NULL, super_minor);
if (err == -EINVAL) {
pr_warn("md: %pg does not have a valid v%d.%d superblock, not importing!\n",
rdev->bdev,
super_format, super_minor);
goto out_blkdev_put;
}
if (err < 0) {
pr_warn("md: could not read %pg's sb, not importing!\n",
rdev->bdev);
goto out_blkdev_put;
}
}
return rdev;
out_blkdev_put:
blkdev_put(rdev->bdev, holder);
out_clear_rdev:
md_rdev_clear(rdev);
out_free_rdev:
kfree(rdev);
return ERR_PTR(err);
}
/*
* Check a full RAID array for plausibility
*/
static int analyze_sbs(struct mddev *mddev)
{
int i;
struct md_rdev *rdev, *freshest, *tmp;
freshest = NULL;
rdev_for_each_safe(rdev, tmp, mddev)
switch (super_types[mddev->major_version].
load_super(rdev, freshest, mddev->minor_version)) {
case 1:
freshest = rdev;
break;
case 0:
break;
default:
pr_warn("md: fatal superblock inconsistency in %pg -- removing from array\n",
rdev->bdev);
md_kick_rdev_from_array(rdev);
}
/* Cannot find a valid fresh disk */
if (!freshest) {
pr_warn("md: cannot find a valid disk\n");
return -EINVAL;
}
super_types[mddev->major_version].
validate_super(mddev, freshest);
i = 0;
rdev_for_each_safe(rdev, tmp, mddev) {
if (mddev->max_disks &&
(rdev->desc_nr >= mddev->max_disks ||
i > mddev->max_disks)) {
pr_warn("md: %s: %pg: only %d devices permitted\n",
mdname(mddev), rdev->bdev,
mddev->max_disks);
md_kick_rdev_from_array(rdev);
continue;
}
if (rdev != freshest) {
if (super_types[mddev->major_version].
validate_super(mddev, rdev)) {
pr_warn("md: kicking non-fresh %pg from array!\n",
rdev->bdev);
md_kick_rdev_from_array(rdev);
continue;
}
}
if (mddev->level == LEVEL_MULTIPATH) {
rdev->desc_nr = i++;
rdev->raid_disk = rdev->desc_nr;
set_bit(In_sync, &rdev->flags);
} else if (rdev->raid_disk >=
(mddev->raid_disks - min(0, mddev->delta_disks)) &&
!test_bit(Journal, &rdev->flags)) {
rdev->raid_disk = -1;
clear_bit(In_sync, &rdev->flags);
}
}
return 0;
}
/* Read a fixed-point number.
* Numbers in sysfs attributes should be in "standard" units where
* possible, so time should be in seconds.
* However we internally use a a much smaller unit such as
* milliseconds or jiffies.
* This function takes a decimal number with a possible fractional
* component, and produces an integer which is the result of
* multiplying that number by 10^'scale'.
* all without any floating-point arithmetic.
*/
int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale)
{
unsigned long result = 0;
long decimals = -1;
while (isdigit(*cp) || (*cp == '.' && decimals < 0)) {
if (*cp == '.')
decimals = 0;
else if (decimals < scale) {
unsigned int value;
value = *cp - '0';
result = result * 10 + value;
if (decimals >= 0)
decimals++;
}
cp++;
}
if (*cp == '\n')
cp++;
if (*cp)
return -EINVAL;
if (decimals < 0)
decimals = 0;
*res = result * int_pow(10, scale - decimals);
return 0;
}
static ssize_t
safe_delay_show(struct mddev *mddev, char *page)
{
unsigned int msec = ((unsigned long)mddev->safemode_delay*1000)/HZ;
return sprintf(page, "%u.%03u\n", msec/1000, msec%1000);
}
static ssize_t
safe_delay_store(struct mddev *mddev, const char *cbuf, size_t len)
{
unsigned long msec;
if (mddev_is_clustered(mddev)) {
pr_warn("md: Safemode is disabled for clustered mode\n");
return -EINVAL;
}
if (strict_strtoul_scaled(cbuf, &msec, 3) < 0 || msec > UINT_MAX / HZ)
return -EINVAL;
if (msec == 0)
mddev->safemode_delay = 0;
else {
unsigned long old_delay = mddev->safemode_delay;
unsigned long new_delay = (msec*HZ)/1000;
if (new_delay == 0)
new_delay = 1;
mddev->safemode_delay = new_delay;
if (new_delay < old_delay || old_delay == 0)
mod_timer(&mddev->safemode_timer, jiffies+1);
}
return len;
}
static struct md_sysfs_entry md_safe_delay =
__ATTR(safe_mode_delay, S_IRUGO|S_IWUSR,safe_delay_show, safe_delay_store);
static ssize_t
level_show(struct mddev *mddev, char *page)
{
struct md_personality *p;
int ret;
spin_lock(&mddev->lock);
p = mddev->pers;
if (p)
ret = sprintf(page, "%s\n", p->name);
else if (mddev->clevel[0])
ret = sprintf(page, "%s\n", mddev->clevel);
else if (mddev->level != LEVEL_NONE)
ret = sprintf(page, "%d\n", mddev->level);
else
ret = 0;
spin_unlock(&mddev->lock);
return ret;
}
static ssize_t
level_store(struct mddev *mddev, const char *buf, size_t len)
{
char clevel[16];
ssize_t rv;
size_t slen = len;
struct md_personality *pers, *oldpers;
long level;
void *priv, *oldpriv;
struct md_rdev *rdev;
if (slen == 0 || slen >= sizeof(clevel))
return -EINVAL;
rv = mddev_lock(mddev);
if (rv)
return rv;
if (mddev->pers == NULL) {
strncpy(mddev->clevel, buf, slen);
if (mddev->clevel[slen-1] == '\n')
slen--;
mddev->clevel[slen] = 0;
mddev->level = LEVEL_NONE;
rv = len;
goto out_unlock;
}
rv = -EROFS;
if (!md_is_rdwr(mddev))
goto out_unlock;
/* request to change the personality. Need to ensure:
* - array is not engaged in resync/recovery/reshape
* - old personality can be suspended
* - new personality will access other array.
*/
rv = -EBUSY;
if (mddev->sync_thread ||
test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
mddev->reshape_position != MaxSector ||
mddev->sysfs_active)
goto out_unlock;
rv = -EINVAL;
if (!mddev->pers->quiesce) {
pr_warn("md: %s: %s does not support online personality change\n",
mdname(mddev), mddev->pers->name);
goto out_unlock;
}
/* Now find the new personality */
strncpy(clevel, buf, slen);
if (clevel[slen-1] == '\n')
slen--;
clevel[slen] = 0;
if (kstrtol(clevel, 10, &level))
level = LEVEL_NONE;
if (request_module("md-%s", clevel) != 0)
request_module("md-level-%s", clevel);
spin_lock(&pers_lock);
pers = find_pers(level, clevel);
if (!pers || !try_module_get(pers->owner)) {
spin_unlock(&pers_lock);
pr_warn("md: personality %s not loaded\n", clevel);
rv = -EINVAL;
goto out_unlock;
}
spin_unlock(&pers_lock);
if (pers == mddev->pers) {
/* Nothing to do! */
module_put(pers->owner);
rv = len;
goto out_unlock;
}
if (!pers->takeover) {
module_put(pers->owner);
pr_warn("md: %s: %s does not support personality takeover\n",
mdname(mddev), clevel);
rv = -EINVAL;
goto out_unlock;
}
rdev_for_each(rdev, mddev)
rdev->new_raid_disk = rdev->raid_disk;
/* ->takeover must set new_* and/or delta_disks
* if it succeeds, and may set them when it fails.
*/
priv = pers->takeover(mddev);
if (IS_ERR(priv)) {
mddev->new_level = mddev->level;
mddev->new_layout = mddev->layout;
mddev->new_chunk_sectors = mddev->chunk_sectors;
mddev->raid_disks -= mddev->delta_disks;
mddev->delta_disks = 0;
mddev->reshape_backwards = 0;
module_put(pers->owner);
pr_warn("md: %s: %s would not accept array\n",
mdname(mddev), clevel);
rv = PTR_ERR(priv);
goto out_unlock;
}
/* Looks like we have a winner */
mddev_suspend(mddev);
mddev_detach(mddev);
spin_lock(&mddev->lock);
oldpers = mddev->pers;
oldpriv = mddev->private;
mddev->pers = pers;
mddev->private = priv;
strscpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
mddev->level = mddev->new_level;
mddev->layout = mddev->new_layout;
mddev->chunk_sectors = mddev->new_chunk_sectors;
mddev->delta_disks = 0;
mddev->reshape_backwards = 0;
mddev->degraded = 0;
spin_unlock(&mddev->lock);
if (oldpers->sync_request == NULL &&
mddev->external) {
/* We are converting from a no-redundancy array
* to a redundancy array and metadata is managed
* externally so we need to be sure that writes
* won't block due to a need to transition
* clean->dirty
* until external management is started.
*/
mddev->in_sync = 0;
mddev->safemode_delay = 0;
mddev->safemode = 0;
}
oldpers->free(mddev, oldpriv);
if (oldpers->sync_request == NULL &&
pers->sync_request != NULL) {
/* need to add the md_redundancy_group */
if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
pr_warn("md: cannot register extra attributes for %s\n",
mdname(mddev));
mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, "sync_action");
mddev->sysfs_completed = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_completed");
mddev->sysfs_degraded = sysfs_get_dirent_safe(mddev->kobj.sd, "degraded");
}
if (oldpers->sync_request != NULL &&
pers->sync_request == NULL) {
/* need to remove the md_redundancy_group */
if (mddev->to_remove == NULL)
mddev->to_remove = &md_redundancy_group;
}
module_put(oldpers->owner);
rdev_for_each(rdev, mddev) {
if (rdev->raid_disk < 0)
continue;
if (rdev->new_raid_disk >= mddev->raid_disks)
rdev->new_raid_disk = -1;
if (rdev->new_raid_disk == rdev->raid_disk)
continue;
sysfs_unlink_rdev(mddev, rdev);
}
rdev_for_each(rdev, mddev) {
if (rdev->raid_disk < 0)
continue;
if (rdev->new_raid_disk == rdev->raid_disk)
continue;
rdev->raid_disk = rdev->new_raid_disk;
if (rdev->raid_disk < 0)
clear_bit(In_sync, &rdev->flags);
else {
if (sysfs_link_rdev(mddev, rdev))
pr_warn("md: cannot register rd%d for %s after level change\n",
rdev->raid_disk, mdname(mddev));
}
}
if (pers->sync_request == NULL) {
/* this is now an array without redundancy, so
* it must always be in_sync
*/
mddev->in_sync = 1;
del_timer_sync(&mddev->safemode_timer);
}
blk_set_stacking_limits(&mddev->queue->limits);
pers->run(mddev);
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
mddev_resume(mddev);
if (!mddev->thread)
md_update_sb(mddev, 1);
sysfs_notify_dirent_safe(mddev->sysfs_level);
md_new_event();
rv = len;
out_unlock:
mddev_unlock(mddev);
return rv;
}
static struct md_sysfs_entry md_level =
__ATTR(level, S_IRUGO|S_IWUSR, level_show, level_store);
static ssize_t
layout_show(struct mddev *mddev, char *page)
{
/* just a number, not meaningful for all levels */
if (mddev->reshape_position != MaxSector &&
mddev->layout != mddev->new_layout)
return sprintf(page, "%d (%d)\n",
mddev->new_layout, mddev->layout);
return sprintf(page, "%d\n", mddev->layout);
}
static ssize_t
layout_store(struct mddev *mddev, const char *buf, size_t len)
{
unsigned int n;
int err;
err = kstrtouint(buf, 10, &n);
if (err < 0)
return err;
err = mddev_lock(mddev);
if (err)
return err;
if (mddev->pers) {
if (mddev->pers->check_reshape == NULL)
err = -EBUSY;
else if (!md_is_rdwr(mddev))
err = -EROFS;
else {
mddev->new_layout = n;
err = mddev->pers->check_reshape(mddev);
if (err)
mddev->new_layout = mddev->layout;
}
} else {
mddev->new_layout = n;
if (mddev->reshape_position == MaxSector)
mddev->layout = n;
}
mddev_unlock(mddev);
return err ?: len;
}
static struct md_sysfs_entry md_layout =
__ATTR(layout, S_IRUGO|S_IWUSR, layout_show, layout_store);
static ssize_t
raid_disks_show(struct mddev *mddev, char *page)
{
if (mddev->raid_disks == 0)
return 0;
if (mddev->reshape_position != MaxSector &&
mddev->delta_disks != 0)
return sprintf(page, "%d (%d)\n", mddev->raid_disks,
mddev->raid_disks - mddev->delta_disks);
return sprintf(page, "%d\n", mddev->raid_disks);
}
static int update_raid_disks(struct mddev *mddev, int raid_disks);
static ssize_t
raid_disks_store(struct mddev *mddev, const char *buf, size_t len)
{
unsigned int n;
int err;
err = kstrtouint(buf, 10, &n);
if (err < 0)
return err;
err = mddev_lock(mddev);
if (err)
return err;
if (mddev->pers)
err = update_raid_disks(mddev, n);
else if (mddev->reshape_position != MaxSector) {
struct md_rdev *rdev;
int olddisks = mddev->raid_disks - mddev->delta_disks;
err = -EINVAL;
rdev_for_each(rdev, mddev) {
if (olddisks < n &&
rdev->data_offset < rdev->new_data_offset)
goto out_unlock;
if (olddisks > n &&
rdev->data_offset > rdev->new_data_offset)
goto out_unlock;
}
err = 0;
mddev->delta_disks = n - olddisks;
mddev->raid_disks = n;
mddev->reshape_backwards = (mddev->delta_disks < 0);
} else
mddev->raid_disks = n;
out_unlock:
mddev_unlock(mddev);
return err ? err : len;
}
static struct md_sysfs_entry md_raid_disks =
__ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);
static ssize_t
uuid_show(struct mddev *mddev, char *page)
{
return sprintf(page, "%pU\n", mddev->uuid);
}
static struct md_sysfs_entry md_uuid =
__ATTR(uuid, S_IRUGO, uuid_show, NULL);
static ssize_t
chunk_size_show(struct mddev *mddev, char *page)
{
if (mddev->reshape_position != MaxSector &&
mddev->chunk_sectors != mddev->new_chunk_sectors)
return sprintf(page, "%d (%d)\n",
mddev->new_chunk_sectors << 9,
mddev->chunk_sectors << 9);
return sprintf(page, "%d\n", mddev->chunk_sectors << 9);
}
static ssize_t
chunk_size_store(struct mddev *mddev, const char *buf, size_t len)
{
unsigned long n;
int err;
err = kstrtoul(buf, 10, &n);
if (err < 0)
return err;
err = mddev_lock(mddev);
if (err)
return err;
if (mddev->pers) {
if (mddev->pers->check_reshape == NULL)
err = -EBUSY;
else if (!md_is_rdwr(mddev))
err = -EROFS;
else {
mddev->new_chunk_sectors = n >> 9;
err = mddev->pers->check_reshape(mddev);
if (err)
mddev->new_chunk_sectors = mddev->chunk_sectors;
}
} else {
mddev->new_chunk_sectors = n >> 9;
if (mddev->reshape_position == MaxSector)
mddev->chunk_sectors = n >> 9;
}
mddev_unlock(mddev);
return err ?: len;
}
static struct md_sysfs_entry md_chunk_size =
__ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
static ssize_t
resync_start_show(struct mddev *mddev, char *page)
{
if (mddev->recovery_cp == MaxSector)
return sprintf(page, "none\n");
return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
}
static ssize_t
resync_start_store(struct mddev *mddev, const char *buf, size_t len)
{
unsigned long long n;
int err;
if (cmd_match(buf, "none"))
n = MaxSector;
else {
err = kstrtoull(buf, 10, &n);
if (err < 0)
return err;
if (n != (sector_t)n)
return -EINVAL;
}
err = mddev_lock(mddev);
if (err)
return err;
if (mddev->pers && !test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
err = -EBUSY;
if (!err) {
mddev->recovery_cp = n;
if (mddev->pers)
set_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
}
mddev_unlock(mddev);
return err ?: len;
}
static struct md_sysfs_entry md_resync_start =
__ATTR_PREALLOC(resync_start, S_IRUGO|S_IWUSR,
resync_start_show, resync_start_store);
/*
* The array state can be:
*
* clear
* No devices, no size, no level
* Equivalent to STOP_ARRAY ioctl
* inactive
* May have some settings, but array is not active
* all IO results in error
* When written, doesn't tear down array, but just stops it
* suspended (not supported yet)
* All IO requests will block. The array can be reconfigured.
* Writing this, if accepted, will block until array is quiescent
* readonly
* no resync can happen. no superblocks get written.
* write requests fail
* read-auto
* like readonly, but behaves like 'clean' on a write request.
*
* clean - no pending writes, but otherwise active.
* When written to inactive array, starts without resync
* If a write request arrives then
* if metadata is known, mark 'dirty' and switch to 'active'.
* if not known, block and switch to write-pending
* If written to an active array that has pending writes, then fails.
* active
* fully active: IO and resync can be happening.
* When written to inactive array, starts with resync
*
* write-pending
* clean, but writes are blocked waiting for 'active' to be written.
*
* active-idle
* like active, but no writes have been seen for a while (100msec).
*
* broken
* Array is failed. It's useful because mounted-arrays aren't stopped
* when array is failed, so this state will at least alert the user that
* something is wrong.
*/
enum array_state { clear, inactive, suspended, readonly, read_auto, clean, active,
write_pending, active_idle, broken, bad_word};
static char *array_states[] = {
"clear", "inactive", "suspended", "readonly", "read-auto", "clean", "active",
"write-pending", "active-idle", "broken", NULL };
static int match_word(const char *word, char **list)
{
int n;
for (n=0; list[n]; n++)
if (cmd_match(word, list[n]))
break;
return n;
}
static ssize_t
array_state_show(struct mddev *mddev, char *page)
{
enum array_state st = inactive;
if (mddev->pers && !test_bit(MD_NOT_READY, &mddev->flags)) {
switch(mddev->ro) {
case MD_RDONLY:
st = readonly;
break;
case MD_AUTO_READ:
st = read_auto;
break;
case MD_RDWR:
spin_lock(&mddev->lock);
if (test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags))
st = write_pending;
else if (mddev->in_sync)
st = clean;
else if (mddev->safemode)
st = active_idle;
else
st = active;
spin_unlock(&mddev->lock);
}
if (test_bit(MD_BROKEN, &mddev->flags) && st == clean)
st = broken;
} else {
if (list_empty(&mddev->disks) &&
mddev->raid_disks == 0 &&
mddev->dev_sectors == 0)
st = clear;
else
st = inactive;
}
return sprintf(page, "%s\n", array_states[st]);
}
static int do_md_stop(struct mddev *mddev, int ro, struct block_device *bdev);
static int md_set_readonly(struct mddev *mddev, struct block_device *bdev);
static int restart_array(struct mddev *mddev);
static ssize_t
array_state_store(struct mddev *mddev, const char *buf, size_t len)
{
int err = 0;
enum array_state st = match_word(buf, array_states);
if (mddev->pers && (st == active || st == clean) &&
mddev->ro != MD_RDONLY) {
/* don't take reconfig_mutex when toggling between
* clean and active
*/
spin_lock(&mddev->lock);
if (st == active) {
restart_array(mddev);
clear_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags);
md_wakeup_thread(mddev->thread);
wake_up(&mddev->sb_wait);
} else /* st == clean */ {
restart_array(mddev);
if (!set_in_sync(mddev))
err = -EBUSY;
}
if (!err)
sysfs_notify_dirent_safe(mddev->sysfs_state);
spin_unlock(&mddev->lock);
return err ?: len;
}
err = mddev_lock(mddev);
if (err)
return err;
err = -EINVAL;
switch(st) {
case bad_word:
break;
case clear:
/* stopping an active array */
err = do_md_stop(mddev, 0, NULL);
break;
case inactive:
/* stopping an active array */
if (mddev->pers)
err = do_md_stop(mddev, 2, NULL);
else
err = 0; /* already inactive */
break;
case suspended:
break; /* not supported yet */
case readonly:
if (mddev->pers)
err = md_set_readonly(mddev, NULL);
else {
mddev->ro = MD_RDONLY;
set_disk_ro(mddev->gendisk, 1);
err = do_md_run(mddev);
}
break;
case read_auto:
if (mddev->pers) {
if (md_is_rdwr(mddev))
err = md_set_readonly(mddev, NULL);
else if (mddev->ro == MD_RDONLY)
err = restart_array(mddev);
if (err == 0) {
mddev->ro = MD_AUTO_READ;
set_disk_ro(mddev->gendisk, 0);
}
} else {
mddev->ro = MD_AUTO_READ;
err = do_md_run(mddev);
}
break;
case clean:
if (mddev->pers) {
err = restart_array(mddev);
if (err)
break;
spin_lock(&mddev->lock);
if (!set_in_sync(mddev))
err = -EBUSY;
spin_unlock(&mddev->lock);
} else
err = -EINVAL;
break;
case active:
if (mddev->pers) {
err = restart_array(mddev);
if (err)
break;
clear_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags);
wake_up(&mddev->sb_wait);
err = 0;
} else {
mddev->ro = MD_RDWR;
set_disk_ro(mddev->gendisk, 0);
err = do_md_run(mddev);
}
break;
case write_pending:
case active_idle:
case broken:
/* these cannot be set */
break;
}
if (!err) {
if (mddev->hold_active == UNTIL_IOCTL)
mddev->hold_active = 0;
sysfs_notify_dirent_safe(mddev->sysfs_state);
}
mddev_unlock(mddev);
return err ?: len;
}
static struct md_sysfs_entry md_array_state =
__ATTR_PREALLOC(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
static ssize_t
max_corrected_read_errors_show(struct mddev *mddev, char *page) {
return sprintf(page, "%d\n",
atomic_read(&mddev->max_corr_read_errors));
}
static ssize_t
max_corrected_read_errors_store(struct mddev *mddev, const char *buf, size_t len)
{
unsigned int n;
int rv;
rv = kstrtouint(buf, 10, &n);
if (rv < 0)
return rv;
if (n > INT_MAX)
return -EINVAL;
atomic_set(&mddev->max_corr_read_errors, n);
return len;
}
static struct md_sysfs_entry max_corr_read_errors =
__ATTR(max_read_errors, S_IRUGO|S_IWUSR, max_corrected_read_errors_show,
max_corrected_read_errors_store);
static ssize_t
null_show(struct mddev *mddev, char *page)
{
return -EINVAL;
}
static ssize_t
new_dev_store(struct mddev *mddev, const char *buf, size_t len)
{
/* buf must be %d:%d\n? giving major and minor numbers */
/* The new device is added to the array.
* If the array has a persistent superblock, we read the
* superblock to initialise info and check validity.
* Otherwise, only checking done is that in bind_rdev_to_array,
* which mainly checks size.
*/
char *e;
int major = simple_strtoul(buf, &e, 10);
int minor;
dev_t dev;
struct md_rdev *rdev;
int err;
if (!*buf || *e != ':' || !e[1] || e[1] == '\n')
return -EINVAL;
minor = simple_strtoul(e+1, &e, 10);
if (*e && *e != '\n')
return -EINVAL;
dev = MKDEV(major, minor);
if (major != MAJOR(dev) ||
minor != MINOR(dev))
return -EOVERFLOW;
err = mddev_lock(mddev);
if (err)
return err;
if (mddev->persistent) {
rdev = md_import_device(dev, mddev->major_version,
mddev->minor_version);
if (!IS_ERR(rdev) && !list_empty(&mddev->disks)) {
struct md_rdev *rdev0
= list_entry(mddev->disks.next,
struct md_rdev, same_set);
err = super_types[mddev->major_version]
.load_super(rdev, rdev0, mddev->minor_version);
if (err < 0)
goto out;
}
} else if (mddev->external)
rdev = md_import_device(dev, -2, -1);
else
rdev = md_import_device(dev, -1, -1);
if (IS_ERR(rdev)) {
mddev_unlock(mddev);
return PTR_ERR(rdev);
}
err = bind_rdev_to_array(rdev, mddev);
out:
if (err)
export_rdev(rdev, mddev);
mddev_unlock(mddev);
if (!err)
md_new_event();
return err ? err : len;
}
static struct md_sysfs_entry md_new_device =
__ATTR(new_dev, S_IWUSR, null_show, new_dev_store);
static ssize_t
bitmap_store(struct mddev *mddev, const char *buf, size_t len)
{
char *end;
unsigned long chunk, end_chunk;
int err;
err = mddev_lock(mddev);
if (err)
return err;
if (!mddev->bitmap)
goto out;
/* buf should be <chunk> <chunk> ... or <chunk>-<chunk> ... (range) */
while (*buf) {
chunk = end_chunk = simple_strtoul(buf, &end, 0);
if (buf == end) break;
if (*end == '-') { /* range */
buf = end + 1;
end_chunk = simple_strtoul(buf, &end, 0);
if (buf == end) break;
}
if (*end && !isspace(*end)) break;
md_bitmap_dirty_bits(mddev->bitmap, chunk, end_chunk);
buf = skip_spaces(end);
}
md_bitmap_unplug(mddev->bitmap); /* flush the bits to disk */
out:
mddev_unlock(mddev);
return len;
}
static struct md_sysfs_entry md_bitmap =
__ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store);
static ssize_t
size_show(struct mddev *mddev, char *page)
{
return sprintf(page, "%llu\n",
(unsigned long long)mddev->dev_sectors / 2);
}
static int update_size(struct mddev *mddev, sector_t num_sectors);
static ssize_t
size_store(struct mddev *mddev, const char *buf, size_t len)
{
/* If array is inactive, we can reduce the component size, but
* not increase it (except from 0).
* If array is active, we can try an on-line resize
*/
sector_t sectors;
int err = strict_blocks_to_sectors(buf, §ors);
if (err < 0)
return err;
err = mddev_lock(mddev);
if (err)
return err;
if (mddev->pers) {
err = update_size(mddev, sectors);
if (err == 0)
md_update_sb(mddev, 1);
} else {
if (mddev->dev_sectors == 0 ||
mddev->dev_sectors > sectors)
mddev->dev_sectors = sectors;
else
err = -ENOSPC;
}
mddev_unlock(mddev);
return err ? err : len;
}
static struct md_sysfs_entry md_size =
__ATTR(component_size, S_IRUGO|S_IWUSR, size_show, size_store);
/* Metadata version.
* This is one of
* 'none' for arrays with no metadata (good luck...)
* 'external' for arrays with externally managed metadata,
* or N.M for internally known formats
*/
static ssize_t
metadata_show(struct mddev *mddev, char *page)
{
if (mddev->persistent)
return sprintf(page, "%d.%d\n",
mddev->major_version, mddev->minor_version);
else if (mddev->external)
return sprintf(page, "external:%s\n", mddev->metadata_type);
else
return sprintf(page, "none\n");
}
static ssize_t
metadata_store(struct mddev *mddev, const char *buf, size_t len)
{
int major, minor;
char *e;
int err;
/* Changing the details of 'external' metadata is
* always permitted. Otherwise there must be
* no devices attached to the array.
*/
err = mddev_lock(mddev);
if (err)
return err;
err = -EBUSY;
if (mddev->external && strncmp(buf, "external:", 9) == 0)
;
else if (!list_empty(&mddev->disks))
goto out_unlock;
err = 0;
if (cmd_match(buf, "none")) {
mddev->persistent = 0;
mddev->external = 0;
mddev->major_version = 0;
mddev->minor_version = 90;
goto out_unlock;
}
if (strncmp(buf, "external:", 9) == 0) {
size_t namelen = len-9;
if (namelen >= sizeof(mddev->metadata_type))
namelen = sizeof(mddev->metadata_type)-1;
strncpy(mddev->metadata_type, buf+9, namelen);
mddev->metadata_type[namelen] = 0;
if (namelen && mddev->metadata_type[namelen-1] == '\n')
mddev->metadata_type[--namelen] = 0;
mddev->persistent = 0;
mddev->external = 1;
mddev->major_version = 0;
mddev->minor_version = 90;
goto out_unlock;
}
major = simple_strtoul(buf, &e, 10);
err = -EINVAL;
if (e==buf || *e != '.')
goto out_unlock;
buf = e+1;
minor = simple_strtoul(buf, &e, 10);
if (e==buf || (*e && *e != '\n') )
goto out_unlock;
err = -ENOENT;
if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL)
goto out_unlock;
mddev->major_version = major;
mddev->minor_version = minor;
mddev->persistent = 1;
mddev->external = 0;
err = 0;
out_unlock:
mddev_unlock(mddev);
return err ?: len;
}
static struct md_sysfs_entry md_metadata =
__ATTR_PREALLOC(metadata_version, S_IRUGO|S_IWUSR, metadata_show, metadata_store);
static ssize_t
action_show(struct mddev *mddev, char *page)
{
char *type = "idle";
unsigned long recovery = mddev->recovery;
if (test_bit(MD_RECOVERY_FROZEN, &recovery))
type = "frozen";
else if (test_bit(MD_RECOVERY_RUNNING, &recovery) ||
(md_is_rdwr(mddev) && test_bit(MD_RECOVERY_NEEDED, &recovery))) {
if (test_bit(MD_RECOVERY_RESHAPE, &recovery))
type = "reshape";
else if (test_bit(MD_RECOVERY_SYNC, &recovery)) {
if (!test_bit(MD_RECOVERY_REQUESTED, &recovery))
type = "resync";
else if (test_bit(MD_RECOVERY_CHECK, &recovery))
type = "check";
else
type = "repair";
} else if (test_bit(MD_RECOVERY_RECOVER, &recovery))
type = "recover";
else if (mddev->reshape_position != MaxSector)
type = "reshape";
}
return sprintf(page, "%s\n", type);
}
static void stop_sync_thread(struct mddev *mddev)
{
if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
return;
if (mddev_lock(mddev))
return;
/*
* Check again in case MD_RECOVERY_RUNNING is cleared before lock is
* held.
*/
if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
mddev_unlock(mddev);
return;
}
if (work_pending(&mddev->del_work))
flush_workqueue(md_misc_wq);
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
/*
* Thread might be blocked waiting for metadata update which will now
* never happen
*/
md_wakeup_thread_directly(mddev->sync_thread);
mddev_unlock(mddev);
}
static void idle_sync_thread(struct mddev *mddev)
{
int sync_seq = atomic_read(&mddev->sync_seq);
mutex_lock(&mddev->sync_mutex);
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
stop_sync_thread(mddev);
wait_event(resync_wait, sync_seq != atomic_read(&mddev->sync_seq) ||
!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery));
mutex_unlock(&mddev->sync_mutex);
}
static void frozen_sync_thread(struct mddev *mddev)
{
mutex_lock(&mddev->sync_mutex);
set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
stop_sync_thread(mddev);
wait_event(resync_wait, mddev->sync_thread == NULL &&
!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery));
mutex_unlock(&mddev->sync_mutex);
}
static ssize_t
action_store(struct mddev *mddev, const char *page, size_t len)
{
if (!mddev->pers || !mddev->pers->sync_request)
return -EINVAL;
if (cmd_match(page, "idle"))
idle_sync_thread(mddev);
else if (cmd_match(page, "frozen"))
frozen_sync_thread(mddev);
else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
return -EBUSY;
else if (cmd_match(page, "resync"))
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
else if (cmd_match(page, "recover")) {
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
} else if (cmd_match(page, "reshape")) {
int err;
if (mddev->pers->start_reshape == NULL)
return -EINVAL;
err = mddev_lock(mddev);
if (!err) {
if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
err = -EBUSY;
} else if (mddev->reshape_position == MaxSector ||
mddev->pers->check_reshape == NULL ||
mddev->pers->check_reshape(mddev)) {
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
err = mddev->pers->start_reshape(mddev);
} else {
/*
* If reshape is still in progress, and
* md_check_recovery() can continue to reshape,
* don't restart reshape because data can be
* corrupted for raid456.
*/
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
}
mddev_unlock(mddev);
}
if (err)
return err;
sysfs_notify_dirent_safe(mddev->sysfs_degraded);
} else {
if (cmd_match(page, "check"))
set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
else if (!cmd_match(page, "repair"))
return -EINVAL;
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
}
if (mddev->ro == MD_AUTO_READ) {
/* A write to sync_action is enough to justify
* canceling read-auto mode
*/
mddev->ro = MD_RDWR;
md_wakeup_thread(mddev->sync_thread);
}
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
sysfs_notify_dirent_safe(mddev->sysfs_action);
return len;
}
static struct md_sysfs_entry md_scan_mode =
__ATTR_PREALLOC(sync_action, S_IRUGO|S_IWUSR, action_show, action_store);
static ssize_t
last_sync_action_show(struct mddev *mddev, char *page)
{
return sprintf(page, "%s\n", mddev->last_sync_action);
}
static struct md_sysfs_entry md_last_scan_mode = __ATTR_RO(last_sync_action);
static ssize_t
mismatch_cnt_show(struct mddev *mddev, char *page)
{
return sprintf(page, "%llu\n",
(unsigned long long)
atomic64_read(&mddev->resync_mismatches));
}
static struct md_sysfs_entry md_mismatches = __ATTR_RO(mismatch_cnt);
static ssize_t
sync_min_show(struct mddev *mddev, char *page)
{
return sprintf(page, "%d (%s)\n", speed_min(mddev),
mddev->sync_speed_min ? "local": "system");
}
static ssize_t
sync_min_store(struct mddev *mddev, const char *buf, size_t len)
{
unsigned int min;
int rv;
if (strncmp(buf, "system", 6)==0) {
min = 0;
} else {
rv = kstrtouint(buf, 10, &min);
if (rv < 0)
return rv;
if (min == 0)
return -EINVAL;
}
mddev->sync_speed_min = min;
return len;
}
static struct md_sysfs_entry md_sync_min =
__ATTR(sync_speed_min, S_IRUGO|S_IWUSR, sync_min_show, sync_min_store);
static ssize_t
sync_max_show(struct mddev *mddev, char *page)
{
return sprintf(page, "%d (%s)\n", speed_max(mddev),
mddev->sync_speed_max ? "local": "system");
}
static ssize_t
sync_max_store(struct mddev *mddev, const char *buf, size_t len)
{
unsigned int max;
int rv;
if (strncmp(buf, "system", 6)==0) {
max = 0;
} else {
rv = kstrtouint(buf, 10, &max);
if (rv < 0)
return rv;
if (max == 0)
return -EINVAL;
}
mddev->sync_speed_max = max;
return len;
}
static struct md_sysfs_entry md_sync_max =
__ATTR(sync_speed_max, S_IRUGO|S_IWUSR, sync_max_show, sync_max_store);
static ssize_t
degraded_show(struct mddev *mddev, char *page)
{
return sprintf(page, "%d\n", mddev->degraded);
}
static struct md_sysfs_entry md_degraded = __ATTR_RO(degraded);
static ssize_t
sync_force_parallel_show(struct mddev *mddev, char *page)
{
return sprintf(page, "%d\n", mddev->parallel_resync);
}
static ssize_t
sync_force_parallel_store(struct mddev *mddev, const char *buf, size_t len)
{
long n;
if (kstrtol(buf, 10, &n))
return -EINVAL;
if (n != 0 && n != 1)
return -EINVAL;
mddev->parallel_resync = n;
if (mddev->sync_thread)
wake_up(&resync_wait);
return len;
}
/* force parallel resync, even with shared block devices */
static struct md_sysfs_entry md_sync_force_parallel =
__ATTR(sync_force_parallel, S_IRUGO|S_IWUSR,
sync_force_parallel_show, sync_force_parallel_store);
static ssize_t
sync_speed_show(struct mddev *mddev, char *page)
{
unsigned long resync, dt, db;
if (mddev->curr_resync == MD_RESYNC_NONE)
return sprintf(page, "none\n");
resync = mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active);
dt = (jiffies - mddev->resync_mark) / HZ;
if (!dt) dt++;
db = resync - mddev->resync_mark_cnt;
return sprintf(page, "%lu\n", db/dt/2); /* K/sec */
}
static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
static ssize_t
sync_completed_show(struct mddev *mddev, char *page)
{
unsigned long long max_sectors, resync;
if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
return sprintf(page, "none\n");
if (mddev->curr_resync == MD_RESYNC_YIELDED ||
mddev->curr_resync == MD_RESYNC_DELAYED)
return sprintf(page, "delayed\n");
if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
max_sectors = mddev->resync_max_sectors;
else
max_sectors = mddev->dev_sectors;
resync = mddev->curr_resync_completed;
return sprintf(page, "%llu / %llu\n", resync, max_sectors);
}
static struct md_sysfs_entry md_sync_completed =
__ATTR_PREALLOC(sync_completed, S_IRUGO, sync_completed_show, NULL);
static ssize_t
min_sync_show(struct mddev *mddev, char *page)
{
return sprintf(page, "%llu\n",
(unsigned long long)mddev->resync_min);
}
static ssize_t
min_sync_store(struct mddev *mddev, const char *buf, size_t len)
{
unsigned long long min;
int err;
if (kstrtoull(buf, 10, &min))
return -EINVAL;
spin_lock(&mddev->lock);
err = -EINVAL;
if (min > mddev->resync_max)
goto out_unlock;
err = -EBUSY;
if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
goto out_unlock;
/* Round down to multiple of 4K for safety */
mddev->resync_min = round_down(min, 8);
err = 0;
out_unlock:
spin_unlock(&mddev->lock);
return err ?: len;
}
static struct md_sysfs_entry md_min_sync =
__ATTR(sync_min, S_IRUGO|S_IWUSR, min_sync_show, min_sync_store);
static ssize_t
max_sync_show(struct mddev *mddev, char *page)
{
if (mddev->resync_max == MaxSector)
return sprintf(page, "max\n");
else
return sprintf(page, "%llu\n",
(unsigned long long)mddev->resync_max);
}
static ssize_t
max_sync_store(struct mddev *mddev, const char *buf, size_t len)
{
int err;
spin_lock(&mddev->lock);
if (strncmp(buf, "max", 3) == 0)
mddev->resync_max = MaxSector;
else {
unsigned long long max;
int chunk;
err = -EINVAL;
if (kstrtoull(buf, 10, &max))
goto out_unlock;
if (max < mddev->resync_min)
goto out_unlock;
err = -EBUSY;
if (max < mddev->resync_max && md_is_rdwr(mddev) &&
test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
goto out_unlock;
/* Must be a multiple of chunk_size */
chunk = mddev->chunk_sectors;
if (chunk) {
sector_t temp = max;
err = -EINVAL;
if (sector_div(temp, chunk))
goto out_unlock;
}
mddev->resync_max = max;
}
wake_up(&mddev->recovery_wait);
err = 0;
out_unlock:
spin_unlock(&mddev->lock);
return err ?: len;
}
static struct md_sysfs_entry md_max_sync =
__ATTR(sync_max, S_IRUGO|S_IWUSR, max_sync_show, max_sync_store);
static ssize_t
suspend_lo_show(struct mddev *mddev, char *page)
{
return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_lo);
}
static ssize_t
suspend_lo_store(struct mddev *mddev, const char *buf, size_t len)
{
unsigned long long new;
int err;
err = kstrtoull(buf, 10, &new);
if (err < 0)
return err;
if (new != (sector_t)new)
return -EINVAL;
err = mddev_lock(mddev);
if (err)
return err;
err = -EINVAL;
if (mddev->pers == NULL ||
mddev->pers->quiesce == NULL)
goto unlock;
mddev_suspend(mddev);
mddev->suspend_lo = new;
mddev_resume(mddev);
err = 0;
unlock:
mddev_unlock(mddev);
return err ?: len;
}
static struct md_sysfs_entry md_suspend_lo =
__ATTR(suspend_lo, S_IRUGO|S_IWUSR, suspend_lo_show, suspend_lo_store);
static ssize_t
suspend_hi_show(struct mddev *mddev, char *page)
{
return sprintf(page, "%llu\n", (unsigned long long)mddev->suspend_hi);
}
static ssize_t
suspend_hi_store(struct mddev *mddev, const char *buf, size_t len)
{
unsigned long long new;
int err;
err = kstrtoull(buf, 10, &new);
if (err < 0)
return err;
if (new != (sector_t)new)
return -EINVAL;
err = mddev_lock(mddev);
if (err)
return err;
err = -EINVAL;
if (mddev->pers == NULL)
goto unlock;
mddev_suspend(mddev);
mddev->suspend_hi = new;
mddev_resume(mddev);
err = 0;
unlock:
mddev_unlock(mddev);
return err ?: len;
}
static struct md_sysfs_entry md_suspend_hi =
__ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
static ssize_t
reshape_position_show(struct mddev *mddev, char *page)
{
if (mddev->reshape_position != MaxSector)
return sprintf(page, "%llu\n",
(unsigned long long)mddev->reshape_position);
strcpy(page, "none\n");
return 5;
}
static ssize_t
reshape_position_store(struct mddev *mddev, const char *buf, size_t len)
{
struct md_rdev *rdev;
unsigned long long new;
int err;
err = kstrtoull(buf, 10, &new);
if (err < 0)
return err;
if (new != (sector_t)new)
return -EINVAL;
err = mddev_lock(mddev);
if (err)
return err;
err = -EBUSY;
if (mddev->pers)
goto unlock;
mddev->reshape_position = new;
mddev->delta_disks = 0;
mddev->reshape_backwards = 0;
mddev->new_level = mddev->level;
mddev->new_layout = mddev->layout;
mddev->new_chunk_sectors = mddev->chunk_sectors;
rdev_for_each(rdev, mddev)
rdev->new_data_offset = rdev->data_offset;
err = 0;
unlock:
mddev_unlock(mddev);
return err ?: len;
}
static struct md_sysfs_entry md_reshape_position =
__ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
reshape_position_store);
static ssize_t
reshape_direction_show(struct mddev *mddev, char *page)
{
return sprintf(page, "%s\n",
mddev->reshape_backwards ? "backwards" : "forwards");
}
static ssize_t
reshape_direction_store(struct mddev *mddev, const char *buf, size_t len)
{
int backwards = 0;
int err;
if (cmd_match(buf, "forwards"))
backwards = 0;
else if (cmd_match(buf, "backwards"))
backwards = 1;
else
return -EINVAL;
if (mddev->reshape_backwards == backwards)
return len;
err = mddev_lock(mddev);
if (err)
return err;
/* check if we are allowed to change */
if (mddev->delta_disks)
err = -EBUSY;
else if (mddev->persistent &&
mddev->major_version == 0)
err = -EINVAL;
else
mddev->reshape_backwards = backwards;
mddev_unlock(mddev);
return err ?: len;
}
static struct md_sysfs_entry md_reshape_direction =
__ATTR(reshape_direction, S_IRUGO|S_IWUSR, reshape_direction_show,
reshape_direction_store);
static ssize_t
array_size_show(struct mddev *mddev, char *page)
{
if (mddev->external_size)
return sprintf(page, "%llu\n",
(unsigned long long)mddev->array_sectors/2);
else
return sprintf(page, "default\n");
}
static ssize_t
array_size_store(struct mddev *mddev, const char *buf, size_t len)
{
sector_t sectors;
int err;
err = mddev_lock(mddev);
if (err)
return err;
/* cluster raid doesn't support change array_sectors */
if (mddev_is_clustered(mddev)) {
mddev_unlock(mddev);
return -EINVAL;
}
if (strncmp(buf, "default", 7) == 0) {
if (mddev->pers)
sectors = mddev->pers->size(mddev, 0, 0);
else
sectors = mddev->array_sectors;
mddev->external_size = 0;
} else {
if (strict_blocks_to_sectors(buf, §ors) < 0)
err = -EINVAL;
else if (mddev->pers && mddev->pers->size(mddev, 0, 0) < sectors)
err = -E2BIG;
else
mddev->external_size = 1;
}
if (!err) {
mddev->array_sectors = sectors;
if (mddev->pers)
set_capacity_and_notify(mddev->gendisk,
mddev->array_sectors);
}
mddev_unlock(mddev);
return err ?: len;
}
static struct md_sysfs_entry md_array_size =
__ATTR(array_size, S_IRUGO|S_IWUSR, array_size_show,
array_size_store);
static ssize_t
consistency_policy_show(struct mddev *mddev, char *page)
{
int ret;
if (test_bit(MD_HAS_JOURNAL, &mddev->flags)) {
ret = sprintf(page, "journal\n");
} else if (test_bit(MD_HAS_PPL, &mddev->flags)) {
ret = sprintf(page, "ppl\n");
} else if (mddev->bitmap) {
ret = sprintf(page, "bitmap\n");
} else if (mddev->pers) {
if (mddev->pers->sync_request)
ret = sprintf(page, "resync\n");
else
ret = sprintf(page, "none\n");
} else {
ret = sprintf(page, "unknown\n");
}
return ret;
}
static ssize_t
consistency_policy_store(struct mddev *mddev, const char *buf, size_t len)
{
int err = 0;
if (mddev->pers) {
if (mddev->pers->change_consistency_policy)
err = mddev->pers->change_consistency_policy(mddev, buf);
else
err = -EBUSY;
} else if (mddev->external && strncmp(buf, "ppl", 3) == 0) {
set_bit(MD_HAS_PPL, &mddev->flags);
} else {
err = -EINVAL;
}
return err ? err : len;
}
static struct md_sysfs_entry md_consistency_policy =
__ATTR(consistency_policy, S_IRUGO | S_IWUSR, consistency_policy_show,
consistency_policy_store);
static ssize_t fail_last_dev_show(struct mddev *mddev, char *page)
{
return sprintf(page, "%d\n", mddev->fail_last_dev);
}
/*
* Setting fail_last_dev to true to allow last device to be forcibly removed
* from RAID1/RAID10.
*/
static ssize_t
fail_last_dev_store(struct mddev *mddev, const char *buf, size_t len)
{
int ret;
bool value;
ret = kstrtobool(buf, &value);
if (ret)
return ret;
if (value != mddev->fail_last_dev)
mddev->fail_last_dev = value;
return len;
}
static struct md_sysfs_entry md_fail_last_dev =
__ATTR(fail_last_dev, S_IRUGO | S_IWUSR, fail_last_dev_show,
fail_last_dev_store);
static ssize_t serialize_policy_show(struct mddev *mddev, char *page)
{
if (mddev->pers == NULL || (mddev->pers->level != 1))
return sprintf(page, "n/a\n");
else
return sprintf(page, "%d\n", mddev->serialize_policy);
}
/*
* Setting serialize_policy to true to enforce write IO is not reordered
* for raid1.
*/
static ssize_t
serialize_policy_store(struct mddev *mddev, const char *buf, size_t len)
{
int err;
bool value;
err = kstrtobool(buf, &value);
if (err)
return err;
if (value == mddev->serialize_policy)
return len;
err = mddev_lock(mddev);
if (err)
return err;
if (mddev->pers == NULL || (mddev->pers->level != 1)) {
pr_err("md: serialize_policy is only effective for raid1\n");
err = -EINVAL;
goto unlock;
}
mddev_suspend(mddev);
if (value)
mddev_create_serial_pool(mddev, NULL, true);
else
mddev_destroy_serial_pool(mddev, NULL, true);
mddev->serialize_policy = value;
mddev_resume(mddev);
unlock:
mddev_unlock(mddev);
return err ?: len;
}
static struct md_sysfs_entry md_serialize_policy =
__ATTR(serialize_policy, S_IRUGO | S_IWUSR, serialize_policy_show,
serialize_policy_store);
static struct attribute *md_default_attrs[] = {
&md_level.attr,
&md_layout.attr,
&md_raid_disks.attr,
&md_uuid.attr,
&md_chunk_size.attr,
&md_size.attr,
&md_resync_start.attr,
&md_metadata.attr,
&md_new_device.attr,
&md_safe_delay.attr,
&md_array_state.attr,
&md_reshape_position.attr,
&md_reshape_direction.attr,
&md_array_size.attr,
&max_corr_read_errors.attr,
&md_consistency_policy.attr,
&md_fail_last_dev.attr,
&md_serialize_policy.attr,
NULL,
};
static const struct attribute_group md_default_group = {
.attrs = md_default_attrs,
};
static struct attribute *md_redundancy_attrs[] = {
&md_scan_mode.attr,
&md_last_scan_mode.attr,
&md_mismatches.attr,
&md_sync_min.attr,
&md_sync_max.attr,
&md_sync_speed.attr,
&md_sync_force_parallel.attr,
&md_sync_completed.attr,
&md_min_sync.attr,
&md_max_sync.attr,
&md_suspend_lo.attr,
&md_suspend_hi.attr,
&md_bitmap.attr,
&md_degraded.attr,
NULL,
};
static const struct attribute_group md_redundancy_group = {
.name = NULL,
.attrs = md_redundancy_attrs,
};
static const struct attribute_group *md_attr_groups[] = {
&md_default_group,
&md_bitmap_group,
NULL,
};
static ssize_t
md_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
{
struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
struct mddev *mddev = container_of(kobj, struct mddev, kobj);
ssize_t rv;
if (!entry->show)
return -EIO;
spin_lock(&all_mddevs_lock);
if (!mddev_get(mddev)) {
spin_unlock(&all_mddevs_lock);
return -EBUSY;
}
spin_unlock(&all_mddevs_lock);
rv = entry->show(mddev, page);
mddev_put(mddev);
return rv;
}
static ssize_t
md_attr_store(struct kobject *kobj, struct attribute *attr,
const char *page, size_t length)
{
struct md_sysfs_entry *entry = container_of(attr, struct md_sysfs_entry, attr);
struct mddev *mddev = container_of(kobj, struct mddev, kobj);
ssize_t rv;
if (!entry->store)
return -EIO;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
spin_lock(&all_mddevs_lock);
if (!mddev_get(mddev)) {
spin_unlock(&all_mddevs_lock);
return -EBUSY;
}
spin_unlock(&all_mddevs_lock);
rv = entry->store(mddev, page, length);
mddev_put(mddev);
return rv;
}
static void md_kobj_release(struct kobject *ko)
{
struct mddev *mddev = container_of(ko, struct mddev, kobj);
if (mddev->sysfs_state)
sysfs_put(mddev->sysfs_state);
if (mddev->sysfs_level)
sysfs_put(mddev->sysfs_level);
del_gendisk(mddev->gendisk);
put_disk(mddev->gendisk);
}
static const struct sysfs_ops md_sysfs_ops = {
.show = md_attr_show,
.store = md_attr_store,
};
static const struct kobj_type md_ktype = {
.release = md_kobj_release,
.sysfs_ops = &md_sysfs_ops,
.default_groups = md_attr_groups,
};
int mdp_major = 0;
static void mddev_delayed_delete(struct work_struct *ws)
{
struct mddev *mddev = container_of(ws, struct mddev, del_work);
kobject_put(&mddev->kobj);
}
static void no_op(struct percpu_ref *r) {}
int mddev_init_writes_pending(struct mddev *mddev)
{
if (mddev->writes_pending.percpu_count_ptr)
return 0;
if (percpu_ref_init(&mddev->writes_pending, no_op,
PERCPU_REF_ALLOW_REINIT, GFP_KERNEL) < 0)
return -ENOMEM;
/* We want to start with the refcount at zero */
percpu_ref_put(&mddev->writes_pending);
return 0;
}
EXPORT_SYMBOL_GPL(mddev_init_writes_pending);
struct mddev *md_alloc(dev_t dev, char *name)
{
/*
* If dev is zero, name is the name of a device to allocate with
* an arbitrary minor number. It will be "md_???"
* If dev is non-zero it must be a device number with a MAJOR of
* MD_MAJOR or mdp_major. In this case, if "name" is NULL, then
* the device is being created by opening a node in /dev.
* If "name" is not NULL, the device is being created by
* writing to /sys/module/md_mod/parameters/new_array.
*/
static DEFINE_MUTEX(disks_mutex);
struct mddev *mddev;
struct gendisk *disk;
int partitioned;
int shift;
int unit;
int error ;
/*
* Wait for any previous instance of this device to be completely
* removed (mddev_delayed_delete).
*/
flush_workqueue(md_misc_wq);
mutex_lock(&disks_mutex);
mddev = mddev_alloc(dev);
if (IS_ERR(mddev)) {
error = PTR_ERR(mddev);
goto out_unlock;
}
partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
shift = partitioned ? MdpMinorShift : 0;
unit = MINOR(mddev->unit) >> shift;
if (name && !dev) {
/* Need to ensure that 'name' is not a duplicate.
*/
struct mddev *mddev2;
spin_lock(&all_mddevs_lock);
list_for_each_entry(mddev2, &all_mddevs, all_mddevs)
if (mddev2->gendisk &&
strcmp(mddev2->gendisk->disk_name, name) == 0) {
spin_unlock(&all_mddevs_lock);
error = -EEXIST;
goto out_free_mddev;
}
spin_unlock(&all_mddevs_lock);
}
if (name && dev)
/*
* Creating /dev/mdNNN via "newarray", so adjust hold_active.
*/
mddev->hold_active = UNTIL_STOP;
error = -ENOMEM;
disk = blk_alloc_disk(NUMA_NO_NODE);
if (!disk)
goto out_free_mddev;
disk->major = MAJOR(mddev->unit);
disk->first_minor = unit << shift;
disk->minors = 1 << shift;
if (name)
strcpy(disk->disk_name, name);
else if (partitioned)
sprintf(disk->disk_name, "md_d%d", unit);
else
sprintf(disk->disk_name, "md%d", unit);
disk->fops = &md_fops;
disk->private_data = mddev;
mddev->queue = disk->queue;
blk_set_stacking_limits(&mddev->queue->limits);
blk_queue_write_cache(mddev->queue, true, true);
disk->events |= DISK_EVENT_MEDIA_CHANGE;
mddev->gendisk = disk;
error = add_disk(disk);
if (error)
goto out_put_disk;
kobject_init(&mddev->kobj, &md_ktype);
error = kobject_add(&mddev->kobj, &disk_to_dev(disk)->kobj, "%s", "md");
if (error) {
/*
* The disk is already live at this point. Clear the hold flag
* and let mddev_put take care of the deletion, as it isn't any
* different from a normal close on last release now.
*/
mddev->hold_active = 0;
mutex_unlock(&disks_mutex);
mddev_put(mddev);
return ERR_PTR(error);
}
kobject_uevent(&mddev->kobj, KOBJ_ADD);
mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");
mddev->sysfs_level = sysfs_get_dirent_safe(mddev->kobj.sd, "level");
mutex_unlock(&disks_mutex);
return mddev;
out_put_disk:
put_disk(disk);
out_free_mddev:
mddev_free(mddev);
out_unlock:
mutex_unlock(&disks_mutex);
return ERR_PTR(error);
}
static int md_alloc_and_put(dev_t dev, char *name)
{
struct mddev *mddev = md_alloc(dev, name);
if (IS_ERR(mddev))
return PTR_ERR(mddev);
mddev_put(mddev);
return 0;
}
static void md_probe(dev_t dev)
{
if (MAJOR(dev) == MD_MAJOR && MINOR(dev) >= 512)
return;
if (create_on_open)
md_alloc_and_put(dev, NULL);
}
static int add_named_array(const char *val, const struct kernel_param *kp)
{
/*
* val must be "md_*" or "mdNNN".
* For "md_*" we allocate an array with a large free minor number, and
* set the name to val. val must not already be an active name.
* For "mdNNN" we allocate an array with the minor number NNN
* which must not already be in use.
*/
int len = strlen(val);
char buf[DISK_NAME_LEN];
unsigned long devnum;
while (len && val[len-1] == '\n')
len--;
if (len >= DISK_NAME_LEN)
return -E2BIG;
strscpy(buf, val, len+1);
if (strncmp(buf, "md_", 3) == 0)
return md_alloc_and_put(0, buf);
if (strncmp(buf, "md", 2) == 0 &&
isdigit(buf[2]) &&
kstrtoul(buf+2, 10, &devnum) == 0 &&
devnum <= MINORMASK)
return md_alloc_and_put(MKDEV(MD_MAJOR, devnum), NULL);
return -EINVAL;
}
static void md_safemode_timeout(struct timer_list *t)
{
struct mddev *mddev = from_timer(mddev, t, safemode_timer);
mddev->safemode = 1;
if (mddev->external)
sysfs_notify_dirent_safe(mddev->sysfs_state);
md_wakeup_thread(mddev->thread);
}
static int start_dirty_degraded;
static void active_io_release(struct percpu_ref *ref)
{
struct mddev *mddev = container_of(ref, struct mddev, active_io);
wake_up(&mddev->sb_wait);
}
int md_run(struct mddev *mddev)
{
int err;
struct md_rdev *rdev;
struct md_personality *pers;
bool nowait = true;
if (list_empty(&mddev->disks))
/* cannot run an array with no devices.. */
return -EINVAL;
if (mddev->pers)
return -EBUSY;
/* Cannot run until previous stop completes properly */
if (mddev->sysfs_active)
return -EBUSY;
/*
* Analyze all RAID superblock(s)
*/
if (!mddev->raid_disks) {
if (!mddev->persistent)
return -EINVAL;
err = analyze_sbs(mddev);
if (err)
return -EINVAL;
}
if (mddev->level != LEVEL_NONE)
request_module("md-level-%d", mddev->level);
else if (mddev->clevel[0])
request_module("md-%s", mddev->clevel);
/*
* Drop all container device buffers, from now on
* the only valid external interface is through the md
* device.
*/
mddev->has_superblocks = false;
rdev_for_each(rdev, mddev) {
if (test_bit(Faulty, &rdev->flags))
continue;
sync_blockdev(rdev->bdev);
invalidate_bdev(rdev->bdev);
if (mddev->ro != MD_RDONLY && rdev_read_only(rdev)) {
mddev->ro = MD_RDONLY;
if (mddev->gendisk)
set_disk_ro(mddev->gendisk, 1);
}
if (rdev->sb_page)
mddev->has_superblocks = true;
/* perform some consistency tests on the device.
* We don't want the data to overlap the metadata,
* Internal Bitmap issues have been handled elsewhere.
*/
if (rdev->meta_bdev) {
/* Nothing to check */;
} else if (rdev->data_offset < rdev->sb_start) {
if (mddev->dev_sectors &&
rdev->data_offset + mddev->dev_sectors
> rdev->sb_start) {
pr_warn("md: %s: data overlaps metadata\n",
mdname(mddev));
return -EINVAL;
}
} else {
if (rdev->sb_start + rdev->sb_size/512
> rdev->data_offset) {
pr_warn("md: %s: metadata overlaps data\n",
mdname(mddev));
return -EINVAL;
}
}
sysfs_notify_dirent_safe(rdev->sysfs_state);
nowait = nowait && bdev_nowait(rdev->bdev);
}
err = percpu_ref_init(&mddev->active_io, active_io_release,
PERCPU_REF_ALLOW_REINIT, GFP_KERNEL);
if (err)
return err;
if (!bioset_initialized(&mddev->bio_set)) {
err = bioset_init(&mddev->bio_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
if (err)
goto exit_active_io;
}
if (!bioset_initialized(&mddev->sync_set)) {
err = bioset_init(&mddev->sync_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS);
if (err)
goto exit_bio_set;
}
if (!bioset_initialized(&mddev->io_clone_set)) {
err = bioset_init(&mddev->io_clone_set, BIO_POOL_SIZE,
offsetof(struct md_io_clone, bio_clone), 0);
if (err)
goto exit_sync_set;
}
spin_lock(&pers_lock);
pers = find_pers(mddev->level, mddev->clevel);
if (!pers || !try_module_get(pers->owner)) {
spin_unlock(&pers_lock);
if (mddev->level != LEVEL_NONE)
pr_warn("md: personality for level %d is not loaded!\n",
mddev->level);
else
pr_warn("md: personality for level %s is not loaded!\n",
mddev->clevel);
err = -EINVAL;
goto abort;
}
spin_unlock(&pers_lock);
if (mddev->level != pers->level) {
mddev->level = pers->level;
mddev->new_level = pers->level;
}
strscpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
if (mddev->reshape_position != MaxSector &&
pers->start_reshape == NULL) {
/* This personality cannot handle reshaping... */
module_put(pers->owner);
err = -EINVAL;
goto abort;
}
if (pers->sync_request) {
/* Warn if this is a potentially silly
* configuration.
*/
struct md_rdev *rdev2;
int warned = 0;
rdev_for_each(rdev, mddev)
rdev_for_each(rdev2, mddev) {
if (rdev < rdev2 &&
rdev->bdev->bd_disk ==
rdev2->bdev->bd_disk) {
pr_warn("%s: WARNING: %pg appears to be on the same physical disk as %pg.\n",
mdname(mddev),
rdev->bdev,
rdev2->bdev);
warned = 1;
}
}
if (warned)
pr_warn("True protection against single-disk failure might be compromised.\n");
}
mddev->recovery = 0;
/* may be over-ridden by personality */
mddev->resync_max_sectors = mddev->dev_sectors;
mddev->ok_start_degraded = start_dirty_degraded;
if (start_readonly && md_is_rdwr(mddev))
mddev->ro = MD_AUTO_READ; /* read-only, but switch on first write */
err = pers->run(mddev);
if (err)
pr_warn("md: pers->run() failed ...\n");
else if (pers->size(mddev, 0, 0) < mddev->array_sectors) {
WARN_ONCE(!mddev->external_size,
"%s: default size too small, but 'external_size' not in effect?\n",
__func__);
pr_warn("md: invalid array_size %llu > default size %llu\n",
(unsigned long long)mddev->array_sectors / 2,
(unsigned long long)pers->size(mddev, 0, 0) / 2);
err = -EINVAL;
}
if (err == 0 && pers->sync_request &&
(mddev->bitmap_info.file || mddev->bitmap_info.offset)) {
struct bitmap *bitmap;
bitmap = md_bitmap_create(mddev, -1);
if (IS_ERR(bitmap)) {
err = PTR_ERR(bitmap);
pr_warn("%s: failed to create bitmap (%d)\n",
mdname(mddev), err);
} else
mddev->bitmap = bitmap;
}
if (err)
goto bitmap_abort;
if (mddev->bitmap_info.max_write_behind > 0) {
bool create_pool = false;
rdev_for_each(rdev, mddev) {
if (test_bit(WriteMostly, &rdev->flags) &&
rdev_init_serial(rdev))
create_pool = true;
}
if (create_pool && mddev->serial_info_pool == NULL) {
mddev->serial_info_pool =
mempool_create_kmalloc_pool(NR_SERIAL_INFOS,
sizeof(struct serial_info));
if (!mddev->serial_info_pool) {
err = -ENOMEM;
goto bitmap_abort;
}
}
}
if (mddev->queue) {
bool nonrot = true;
rdev_for_each(rdev, mddev) {
if (rdev->raid_disk >= 0 && !bdev_nonrot(rdev->bdev)) {
nonrot = false;
break;
}
}
if (mddev->degraded)
nonrot = false;
if (nonrot)
blk_queue_flag_set(QUEUE_FLAG_NONROT, mddev->queue);
else
blk_queue_flag_clear(QUEUE_FLAG_NONROT, mddev->queue);
blk_queue_flag_set(QUEUE_FLAG_IO_STAT, mddev->queue);
/* Set the NOWAIT flags if all underlying devices support it */
if (nowait)
blk_queue_flag_set(QUEUE_FLAG_NOWAIT, mddev->queue);
}
if (pers->sync_request) {
if (mddev->kobj.sd &&
sysfs_create_group(&mddev->kobj, &md_redundancy_group))
pr_warn("md: cannot register extra attributes for %s\n",
mdname(mddev));
mddev->sysfs_action = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_action");
mddev->sysfs_completed = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_completed");
mddev->sysfs_degraded = sysfs_get_dirent_safe(mddev->kobj.sd, "degraded");
} else if (mddev->ro == MD_AUTO_READ)
mddev->ro = MD_RDWR;
atomic_set(&mddev->max_corr_read_errors,
MD_DEFAULT_MAX_CORRECTED_READ_ERRORS);
mddev->safemode = 0;
if (mddev_is_clustered(mddev))
mddev->safemode_delay = 0;
else
mddev->safemode_delay = DEFAULT_SAFEMODE_DELAY;
mddev->in_sync = 1;
smp_wmb();
spin_lock(&mddev->lock);
mddev->pers = pers;
spin_unlock(&mddev->lock);
rdev_for_each(rdev, mddev)
if (rdev->raid_disk >= 0)
sysfs_link_rdev(mddev, rdev); /* failure here is OK */
if (mddev->degraded && md_is_rdwr(mddev))
/* This ensures that recovering status is reported immediately
* via sysfs - until a lack of spares is confirmed.
*/
set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
if (mddev->sb_flags)
md_update_sb(mddev, 0);
md_new_event();
return 0;
bitmap_abort:
mddev_detach(mddev);
if (mddev->private)
pers->free(mddev, mddev->private);
mddev->private = NULL;
module_put(pers->owner);
md_bitmap_destroy(mddev);
abort:
bioset_exit(&mddev->io_clone_set);
exit_sync_set:
bioset_exit(&mddev->sync_set);
exit_bio_set:
bioset_exit(&mddev->bio_set);
exit_active_io:
percpu_ref_exit(&mddev->active_io);
return err;
}
EXPORT_SYMBOL_GPL(md_run);
int do_md_run(struct mddev *mddev)
{
int err;
set_bit(MD_NOT_READY, &mddev->flags);
err = md_run(mddev);
if (err)
goto out;
err = md_bitmap_load(mddev);
if (err) {
md_bitmap_destroy(mddev);
goto out;
}
if (mddev_is_clustered(mddev))
md_allow_write(mddev);
/* run start up tasks that require md_thread */
md_start(mddev);
md_wakeup_thread(mddev->thread);
md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
set_capacity_and_notify(mddev->gendisk, mddev->array_sectors);
clear_bit(MD_NOT_READY, &mddev->flags);
mddev->changed = 1;
kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
sysfs_notify_dirent_safe(mddev->sysfs_state);
sysfs_notify_dirent_safe(mddev->sysfs_action);
sysfs_notify_dirent_safe(mddev->sysfs_degraded);
out:
clear_bit(MD_NOT_READY, &mddev->flags);
return err;
}
int md_start(struct mddev *mddev)
{
int ret = 0;
if (mddev->pers->start) {
set_bit(MD_RECOVERY_WAIT, &mddev->recovery);
md_wakeup_thread(mddev->thread);
ret = mddev->pers->start(mddev);
clear_bit(MD_RECOVERY_WAIT, &mddev->recovery);
md_wakeup_thread(mddev->sync_thread);
}
return ret;
}
EXPORT_SYMBOL_GPL(md_start);
static int restart_array(struct mddev *mddev)
{
struct gendisk *disk = mddev->gendisk;
struct md_rdev *rdev;
bool has_journal = false;
bool has_readonly = false;
/* Complain if it has no devices */
if (list_empty(&mddev->disks))
return -ENXIO;
if (!mddev->pers)
return -EINVAL;
if (md_is_rdwr(mddev))
return -EBUSY;
rcu_read_lock();
rdev_for_each_rcu(rdev, mddev) {
if (test_bit(Journal, &rdev->flags) &&
!test_bit(Faulty, &rdev->flags))
has_journal = true;
if (rdev_read_only(rdev))
has_readonly = true;
}
rcu_read_unlock();
if (test_bit(MD_HAS_JOURNAL, &mddev->flags) && !has_journal)
/* Don't restart rw with journal missing/faulty */
return -EINVAL;
if (has_readonly)
return -EROFS;
mddev->safemode = 0;
mddev->ro = MD_RDWR;
set_disk_ro(disk, 0);
pr_debug("md: %s switched to read-write mode.\n", mdname(mddev));
/* Kick recovery or resync if necessary */
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
md_wakeup_thread(mddev->sync_thread);
sysfs_notify_dirent_safe(mddev->sysfs_state);
return 0;
}
static void md_clean(struct mddev *mddev)
{
mddev->array_sectors = 0;
mddev->external_size = 0;
mddev->dev_sectors = 0;
mddev->raid_disks = 0;
mddev->recovery_cp = 0;
mddev->resync_min = 0;
mddev->resync_max = MaxSector;
mddev->reshape_position = MaxSector;
/* we still need mddev->external in export_rdev, do not clear it yet */
mddev->persistent = 0;
mddev->level = LEVEL_NONE;
mddev->clevel[0] = 0;
mddev->flags = 0;
mddev->sb_flags = 0;
mddev->ro = MD_RDWR;
mddev->metadata_type[0] = 0;
mddev->chunk_sectors = 0;
mddev->ctime = mddev->utime = 0;
mddev->layout = 0;
mddev->max_disks = 0;
mddev->events = 0;
mddev->can_decrease_events = 0;
mddev->delta_disks = 0;
mddev->reshape_backwards = 0;
mddev->new_level = LEVEL_NONE;
mddev->new_layout = 0;
mddev->new_chunk_sectors = 0;
mddev->curr_resync = MD_RESYNC_NONE;
atomic64_set(&mddev->resync_mismatches, 0);
mddev->suspend_lo = mddev->suspend_hi = 0;
mddev->sync_speed_min = mddev->sync_speed_max = 0;
mddev->recovery = 0;
mddev->in_sync = 0;
mddev->changed = 0;
mddev->degraded = 0;
mddev->safemode = 0;
mddev->private = NULL;
mddev->cluster_info = NULL;
mddev->bitmap_info.offset = 0;
mddev->bitmap_info.default_offset = 0;
mddev->bitmap_info.default_space = 0;
mddev->bitmap_info.chunksize = 0;
mddev->bitmap_info.daemon_sleep = 0;
mddev->bitmap_info.max_write_behind = 0;
mddev->bitmap_info.nodes = 0;
}
static void __md_stop_writes(struct mddev *mddev)
{
set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
if (work_pending(&mddev->del_work))
flush_workqueue(md_misc_wq);
if (mddev->sync_thread) {
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
md_reap_sync_thread(mddev);
}
del_timer_sync(&mddev->safemode_timer);
if (mddev->pers && mddev->pers->quiesce) {
mddev->pers->quiesce(mddev, 1);
mddev->pers->quiesce(mddev, 0);
}
md_bitmap_flush(mddev);
if (md_is_rdwr(mddev) &&
((!mddev->in_sync && !mddev_is_clustered(mddev)) ||
mddev->sb_flags)) {
/* mark array as shutdown cleanly */
if (!mddev_is_clustered(mddev))
mddev->in_sync = 1;
md_update_sb(mddev, 1);
}
/* disable policy to guarantee rdevs free resources for serialization */
mddev->serialize_policy = 0;
mddev_destroy_serial_pool(mddev, NULL, true);
}
void md_stop_writes(struct mddev *mddev)
{
mddev_lock_nointr(mddev);
__md_stop_writes(mddev);
mddev_unlock(mddev);
}
EXPORT_SYMBOL_GPL(md_stop_writes);
static void mddev_detach(struct mddev *mddev)
{
md_bitmap_wait_behind_writes(mddev);
if (mddev->pers && mddev->pers->quiesce && !is_md_suspended(mddev)) {
mddev->pers->quiesce(mddev, 1);
mddev->pers->quiesce(mddev, 0);
}
md_unregister_thread(mddev, &mddev->thread);
if (mddev->queue)
blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
}
static void __md_stop(struct mddev *mddev)
{
struct md_personality *pers = mddev->pers;
md_bitmap_destroy(mddev);
mddev_detach(mddev);
/* Ensure ->event_work is done */
if (mddev->event_work.func)
flush_workqueue(md_misc_wq);
spin_lock(&mddev->lock);
mddev->pers = NULL;
spin_unlock(&mddev->lock);
if (mddev->private)
pers->free(mddev, mddev->private);
mddev->private = NULL;
if (pers->sync_request && mddev->to_remove == NULL)
mddev->to_remove = &md_redundancy_group;
module_put(pers->owner);
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
percpu_ref_exit(&mddev->active_io);
bioset_exit(&mddev->bio_set);
bioset_exit(&mddev->sync_set);
bioset_exit(&mddev->io_clone_set);
}
void md_stop(struct mddev *mddev)
{
lockdep_assert_held(&mddev->reconfig_mutex);
/* stop the array and free an attached data structures.
* This is called from dm-raid
*/
__md_stop_writes(mddev);
__md_stop(mddev);
percpu_ref_exit(&mddev->writes_pending);
}
EXPORT_SYMBOL_GPL(md_stop);
static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
{
int err = 0;
int did_freeze = 0;
if (!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
did_freeze = 1;
set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
md_wakeup_thread(mddev->thread);
}
if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
/*
* Thread might be blocked waiting for metadata update which will now
* never happen
*/
md_wakeup_thread_directly(mddev->sync_thread);
if (mddev->external && test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags))
return -EBUSY;
mddev_unlock(mddev);
wait_event(resync_wait, !test_bit(MD_RECOVERY_RUNNING,
&mddev->recovery));
wait_event(mddev->sb_wait,
!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
mddev_lock_nointr(mddev);
mutex_lock(&mddev->open_mutex);
if ((mddev->pers && atomic_read(&mddev->openers) > !!bdev) ||
mddev->sync_thread ||
test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
pr_warn("md: %s still in use.\n",mdname(mddev));
if (did_freeze) {
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
}
err = -EBUSY;
goto out;
}
if (mddev->pers) {
__md_stop_writes(mddev);
err = -ENXIO;
if (mddev->ro == MD_RDONLY)
goto out;
mddev->ro = MD_RDONLY;
set_disk_ro(mddev->gendisk, 1);
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
sysfs_notify_dirent_safe(mddev->sysfs_state);
err = 0;
}
out:
mutex_unlock(&mddev->open_mutex);
return err;
}
/* mode:
* 0 - completely stop and dis-assemble array
* 2 - stop but do not disassemble array
*/
static int do_md_stop(struct mddev *mddev, int mode,
struct block_device *bdev)
{
struct gendisk *disk = mddev->gendisk;
struct md_rdev *rdev;
int did_freeze = 0;
if (!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
did_freeze = 1;
set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
md_wakeup_thread(mddev->thread);
}
if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
/*
* Thread might be blocked waiting for metadata update which will now
* never happen
*/
md_wakeup_thread_directly(mddev->sync_thread);
mddev_unlock(mddev);
wait_event(resync_wait, (mddev->sync_thread == NULL &&
!test_bit(MD_RECOVERY_RUNNING,
&mddev->recovery)));
mddev_lock_nointr(mddev);
mutex_lock(&mddev->open_mutex);
if ((mddev->pers && atomic_read(&mddev->openers) > !!bdev) ||
mddev->sysfs_active ||
mddev->sync_thread ||
test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
pr_warn("md: %s still in use.\n",mdname(mddev));
mutex_unlock(&mddev->open_mutex);
if (did_freeze) {
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
}
return -EBUSY;
}
if (mddev->pers) {
if (!md_is_rdwr(mddev))
set_disk_ro(disk, 0);
__md_stop_writes(mddev);
__md_stop(mddev);
/* tell userspace to handle 'inactive' */
sysfs_notify_dirent_safe(mddev->sysfs_state);
rdev_for_each(rdev, mddev)
if (rdev->raid_disk >= 0)
sysfs_unlink_rdev(mddev, rdev);
set_capacity_and_notify(disk, 0);
mutex_unlock(&mddev->open_mutex);
mddev->changed = 1;
if (!md_is_rdwr(mddev))
mddev->ro = MD_RDWR;
} else
mutex_unlock(&mddev->open_mutex);
/*
* Free resources if final stop
*/
if (mode == 0) {
pr_info("md: %s stopped.\n", mdname(mddev));
if (mddev->bitmap_info.file) {
struct file *f = mddev->bitmap_info.file;
spin_lock(&mddev->lock);
mddev->bitmap_info.file = NULL;
spin_unlock(&mddev->lock);
fput(f);
}
mddev->bitmap_info.offset = 0;
export_array(mddev);
md_clean(mddev);
if (mddev->hold_active == UNTIL_STOP)
mddev->hold_active = 0;
}
md_new_event();
sysfs_notify_dirent_safe(mddev->sysfs_state);
return 0;
}
#ifndef MODULE
static void autorun_array(struct mddev *mddev)
{
struct md_rdev *rdev;
int err;
if (list_empty(&mddev->disks))
return;
pr_info("md: running: ");
rdev_for_each(rdev, mddev) {
pr_cont("<%pg>", rdev->bdev);
}
pr_cont("\n");
err = do_md_run(mddev);
if (err) {
pr_warn("md: do_md_run() returned %d\n", err);
do_md_stop(mddev, 0, NULL);
}
}
/*
* lets try to run arrays based on all disks that have arrived
* until now. (those are in pending_raid_disks)
*
* the method: pick the first pending disk, collect all disks with
* the same UUID, remove all from the pending list and put them into
* the 'same_array' list. Then order this list based on superblock
* update time (freshest comes first), kick out 'old' disks and
* compare superblocks. If everything's fine then run it.
*
* If "unit" is allocated, then bump its reference count
*/
static void autorun_devices(int part)
{
struct md_rdev *rdev0, *rdev, *tmp;
struct mddev *mddev;
pr_info("md: autorun ...\n");
while (!list_empty(&pending_raid_disks)) {
int unit;
dev_t dev;
LIST_HEAD(candidates);
rdev0 = list_entry(pending_raid_disks.next,
struct md_rdev, same_set);
pr_debug("md: considering %pg ...\n", rdev0->bdev);
INIT_LIST_HEAD(&candidates);
rdev_for_each_list(rdev, tmp, &pending_raid_disks)
if (super_90_load(rdev, rdev0, 0) >= 0) {
pr_debug("md: adding %pg ...\n",
rdev->bdev);
list_move(&rdev->same_set, &candidates);
}
/*
* now we have a set of devices, with all of them having
* mostly sane superblocks. It's time to allocate the
* mddev.
*/
if (part) {
dev = MKDEV(mdp_major,
rdev0->preferred_minor << MdpMinorShift);
unit = MINOR(dev) >> MdpMinorShift;
} else {
dev = MKDEV(MD_MAJOR, rdev0->preferred_minor);
unit = MINOR(dev);
}
if (rdev0->preferred_minor != unit) {
pr_warn("md: unit number in %pg is bad: %d\n",
rdev0->bdev, rdev0->preferred_minor);
break;
}
mddev = md_alloc(dev, NULL);
if (IS_ERR(mddev))
break;
if (mddev_lock(mddev))
pr_warn("md: %s locked, cannot run\n", mdname(mddev));
else if (mddev->raid_disks || mddev->major_version
|| !list_empty(&mddev->disks)) {
pr_warn("md: %s already running, cannot run %pg\n",
mdname(mddev), rdev0->bdev);
mddev_unlock(mddev);
} else {
pr_debug("md: created %s\n", mdname(mddev));
mddev->persistent = 1;
rdev_for_each_list(rdev, tmp, &candidates) {
list_del_init(&rdev->same_set);
if (bind_rdev_to_array(rdev, mddev))
export_rdev(rdev, mddev);
}
autorun_array(mddev);
mddev_unlock(mddev);
}
/* on success, candidates will be empty, on error
* it won't...
*/
rdev_for_each_list(rdev, tmp, &candidates) {
list_del_init(&rdev->same_set);
export_rdev(rdev, mddev);
}
mddev_put(mddev);
}
pr_info("md: ... autorun DONE.\n");
}
#endif /* !MODULE */
static int get_version(void __user *arg)
{
mdu_version_t ver;
ver.major = MD_MAJOR_VERSION;
ver.minor = MD_MINOR_VERSION;
ver.patchlevel = MD_PATCHLEVEL_VERSION;
if (copy_to_user(arg, &ver, sizeof(ver)))
return -EFAULT;
return 0;
}
static int get_array_info(struct mddev *mddev, void __user *arg)
{
mdu_array_info_t info;
int nr,working,insync,failed,spare;
struct md_rdev *rdev;
nr = working = insync = failed = spare = 0;
rcu_read_lock();
rdev_for_each_rcu(rdev, mddev) {
nr++;
if (test_bit(Faulty, &rdev->flags))
failed++;
else {
working++;
if (test_bit(In_sync, &rdev->flags))
insync++;
else if (test_bit(Journal, &rdev->flags))
/* TODO: add journal count to md_u.h */
;
else
spare++;
}
}
rcu_read_unlock();
info.major_version = mddev->major_version;
info.minor_version = mddev->minor_version;
info.patch_version = MD_PATCHLEVEL_VERSION;
info.ctime = clamp_t(time64_t, mddev->ctime, 0, U32_MAX);
info.level = mddev->level;
info.size = mddev->dev_sectors / 2;
if (info.size != mddev->dev_sectors / 2) /* overflow */
info.size = -1;
info.nr_disks = nr;
info.raid_disks = mddev->raid_disks;
info.md_minor = mddev->md_minor;
info.not_persistent= !mddev->persistent;
info.utime = clamp_t(time64_t, mddev->utime, 0, U32_MAX);
info.state = 0;
if (mddev->in_sync)
info.state = (1<<MD_SB_CLEAN);
if (mddev->bitmap && mddev->bitmap_info.offset)
info.state |= (1<<MD_SB_BITMAP_PRESENT);
if (mddev_is_clustered(mddev))
info.state |= (1<<MD_SB_CLUSTERED);
info.active_disks = insync;
info.working_disks = working;
info.failed_disks = failed;
info.spare_disks = spare;
info.layout = mddev->layout;
info.chunk_size = mddev->chunk_sectors << 9;
if (copy_to_user(arg, &info, sizeof(info)))
return -EFAULT;
return 0;
}
static int get_bitmap_file(struct mddev *mddev, void __user * arg)
{
mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */
char *ptr;
int err;
file = kzalloc(sizeof(*file), GFP_NOIO);
if (!file)
return -ENOMEM;
err = 0;
spin_lock(&mddev->lock);
/* bitmap enabled */
if (mddev->bitmap_info.file) {
ptr = file_path(mddev->bitmap_info.file, file->pathname,
sizeof(file->pathname));
if (IS_ERR(ptr))
err = PTR_ERR(ptr);
else
memmove(file->pathname, ptr,
sizeof(file->pathname)-(ptr-file->pathname));
}
spin_unlock(&mddev->lock);
if (err == 0 &&
copy_to_user(arg, file, sizeof(*file)))
err = -EFAULT;
kfree(file);
return err;
}
static int get_disk_info(struct mddev *mddev, void __user * arg)
{
mdu_disk_info_t info;
struct md_rdev *rdev;
if (copy_from_user(&info, arg, sizeof(info)))
return -EFAULT;
rcu_read_lock();
rdev = md_find_rdev_nr_rcu(mddev, info.number);
if (rdev) {
info.major = MAJOR(rdev->bdev->bd_dev);
info.minor = MINOR(rdev->bdev->bd_dev);
info.raid_disk = rdev->raid_disk;
info.state = 0;
if (test_bit(Faulty, &rdev->flags))
info.state |= (1<<MD_DISK_FAULTY);
else if (test_bit(In_sync, &rdev->flags)) {
info.state |= (1<<MD_DISK_ACTIVE);
info.state |= (1<<MD_DISK_SYNC);
}
if (test_bit(Journal, &rdev->flags))
info.state |= (1<<MD_DISK_JOURNAL);
if (test_bit(WriteMostly, &rdev->flags))
info.state |= (1<<MD_DISK_WRITEMOSTLY);
if (test_bit(FailFast, &rdev->flags))
info.state |= (1<<MD_DISK_FAILFAST);
} else {
info.major = info.minor = 0;
info.raid_disk = -1;
info.state = (1<<MD_DISK_REMOVED);
}
rcu_read_unlock();
if (copy_to_user(arg, &info, sizeof(info)))
return -EFAULT;
return 0;
}
int md_add_new_disk(struct mddev *mddev, struct mdu_disk_info_s *info)
{
struct md_rdev *rdev;
dev_t dev = MKDEV(info->major,info->minor);
if (mddev_is_clustered(mddev) &&
!(info->state & ((1 << MD_DISK_CLUSTER_ADD) | (1 << MD_DISK_CANDIDATE)))) {
pr_warn("%s: Cannot add to clustered mddev.\n",
mdname(mddev));
return -EINVAL;
}
if (info->major != MAJOR(dev) || info->minor != MINOR(dev))
return -EOVERFLOW;
if (!mddev->raid_disks) {
int err;
/* expecting a device which has a superblock */
rdev = md_import_device(dev, mddev->major_version, mddev->minor_version);
if (IS_ERR(rdev)) {
pr_warn("md: md_import_device returned %ld\n",
PTR_ERR(rdev));
return PTR_ERR(rdev);
}
if (!list_empty(&mddev->disks)) {
struct md_rdev *rdev0
= list_entry(mddev->disks.next,
struct md_rdev, same_set);
err = super_types[mddev->major_version]
.load_super(rdev, rdev0, mddev->minor_version);
if (err < 0) {
pr_warn("md: %pg has different UUID to %pg\n",
rdev->bdev,
rdev0->bdev);
export_rdev(rdev, mddev);
return -EINVAL;
}
}
err = bind_rdev_to_array(rdev, mddev);
if (err)
export_rdev(rdev, mddev);
return err;
}
/*
* md_add_new_disk can be used once the array is assembled
* to add "hot spares". They must already have a superblock
* written
*/
if (mddev->pers) {
int err;
if (!mddev->pers->hot_add_disk) {
pr_warn("%s: personality does not support diskops!\n",
mdname(mddev));
return -EINVAL;
}
if (mddev->persistent)
rdev = md_import_device(dev, mddev->major_version,
mddev->minor_version);
else
rdev = md_import_device(dev, -1, -1);
if (IS_ERR(rdev)) {
pr_warn("md: md_import_device returned %ld\n",
PTR_ERR(rdev));
return PTR_ERR(rdev);
}
/* set saved_raid_disk if appropriate */
if (!mddev->persistent) {
if (info->state & (1<<MD_DISK_SYNC) &&
info->raid_disk < mddev->raid_disks) {
rdev->raid_disk = info->raid_disk;
clear_bit(Bitmap_sync, &rdev->flags);
} else
rdev->raid_disk = -1;
rdev->saved_raid_disk = rdev->raid_disk;
} else
super_types[mddev->major_version].
validate_super(mddev, rdev);
if ((info->state & (1<<MD_DISK_SYNC)) &&
rdev->raid_disk != info->raid_disk) {
/* This was a hot-add request, but events doesn't
* match, so reject it.
*/
export_rdev(rdev, mddev);
return -EINVAL;
}
clear_bit(In_sync, &rdev->flags); /* just to be sure */
if (info->state & (1<<MD_DISK_WRITEMOSTLY))
set_bit(WriteMostly, &rdev->flags);
else
clear_bit(WriteMostly, &rdev->flags);
if (info->state & (1<<MD_DISK_FAILFAST))
set_bit(FailFast, &rdev->flags);
else
clear_bit(FailFast, &rdev->flags);
if (info->state & (1<<MD_DISK_JOURNAL)) {
struct md_rdev *rdev2;
bool has_journal = false;
/* make sure no existing journal disk */
rdev_for_each(rdev2, mddev) {
if (test_bit(Journal, &rdev2->flags)) {
has_journal = true;
break;
}
}
if (has_journal || mddev->bitmap) {
export_rdev(rdev, mddev);
return -EBUSY;
}
set_bit(Journal, &rdev->flags);
}
/*
* check whether the device shows up in other nodes
*/
if (mddev_is_clustered(mddev)) {
if (info->state & (1 << MD_DISK_CANDIDATE))
set_bit(Candidate, &rdev->flags);
else if (info->state & (1 << MD_DISK_CLUSTER_ADD)) {
/* --add initiated by this node */
err = md_cluster_ops->add_new_disk(mddev, rdev);
if (err) {
export_rdev(rdev, mddev);
return err;
}
}
}
rdev->raid_disk = -1;
err = bind_rdev_to_array(rdev, mddev);
if (err)
export_rdev(rdev, mddev);
if (mddev_is_clustered(mddev)) {
if (info->state & (1 << MD_DISK_CANDIDATE)) {
if (!err) {
err = md_cluster_ops->new_disk_ack(mddev,
err == 0);
if (err)
md_kick_rdev_from_array(rdev);
}
} else {
if (err)
md_cluster_ops->add_new_disk_cancel(mddev);
else
err = add_bound_rdev(rdev);
}
} else if (!err)
err = add_bound_rdev(rdev);
return err;
}
/* otherwise, md_add_new_disk is only allowed
* for major_version==0 superblocks
*/
if (mddev->major_version != 0) {
pr_warn("%s: ADD_NEW_DISK not supported\n", mdname(mddev));
return -EINVAL;
}
if (!(info->state & (1<<MD_DISK_FAULTY))) {
int err;
rdev = md_import_device(dev, -1, 0);
if (IS_ERR(rdev)) {
pr_warn("md: error, md_import_device() returned %ld\n",
PTR_ERR(rdev));
return PTR_ERR(rdev);
}
rdev->desc_nr = info->number;
if (info->raid_disk < mddev->raid_disks)
rdev->raid_disk = info->raid_disk;
else
rdev->raid_disk = -1;
if (rdev->raid_disk < mddev->raid_disks)
if (info->state & (1<<MD_DISK_SYNC))
set_bit(In_sync, &rdev->flags);
if (info->state & (1<<MD_DISK_WRITEMOSTLY))
set_bit(WriteMostly, &rdev->flags);
if (info->state & (1<<MD_DISK_FAILFAST))
set_bit(FailFast, &rdev->flags);
if (!mddev->persistent) {
pr_debug("md: nonpersistent superblock ...\n");
rdev->sb_start = bdev_nr_sectors(rdev->bdev);
} else
rdev->sb_start = calc_dev_sboffset(rdev);
rdev->sectors = rdev->sb_start;
err = bind_rdev_to_array(rdev, mddev);
if (err) {
export_rdev(rdev, mddev);
return err;
}
}
return 0;
}
static int hot_remove_disk(struct mddev *mddev, dev_t dev)
{
struct md_rdev *rdev;
if (!mddev->pers)
return -ENODEV;
rdev = find_rdev(mddev, dev);
if (!rdev)
return -ENXIO;
if (rdev->raid_disk < 0)
goto kick_rdev;
clear_bit(Blocked, &rdev->flags);
remove_and_add_spares(mddev, rdev);
if (rdev->raid_disk >= 0)
goto busy;
kick_rdev:
if (mddev_is_clustered(mddev)) {
if (md_cluster_ops->remove_disk(mddev, rdev))
goto busy;
}
md_kick_rdev_from_array(rdev);
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
if (mddev->thread)
md_wakeup_thread(mddev->thread);
else
md_update_sb(mddev, 1);
md_new_event();
return 0;
busy:
pr_debug("md: cannot remove active disk %pg from %s ...\n",
rdev->bdev, mdname(mddev));
return -EBUSY;
}
static int hot_add_disk(struct mddev *mddev, dev_t dev)
{
int err;
struct md_rdev *rdev;
if (!mddev->pers)
return -ENODEV;
if (mddev->major_version != 0) {
pr_warn("%s: HOT_ADD may only be used with version-0 superblocks.\n",
mdname(mddev));
return -EINVAL;
}
if (!mddev->pers->hot_add_disk) {
pr_warn("%s: personality does not support diskops!\n",
mdname(mddev));
return -EINVAL;
}
rdev = md_import_device(dev, -1, 0);
if (IS_ERR(rdev)) {
pr_warn("md: error, md_import_device() returned %ld\n",
PTR_ERR(rdev));
return -EINVAL;
}
if (mddev->persistent)
rdev->sb_start = calc_dev_sboffset(rdev);
else
rdev->sb_start = bdev_nr_sectors(rdev->bdev);
rdev->sectors = rdev->sb_start;
if (test_bit(Faulty, &rdev->flags)) {
pr_warn("md: can not hot-add faulty %pg disk to %s!\n",
rdev->bdev, mdname(mddev));
err = -EINVAL;
goto abort_export;
}
clear_bit(In_sync, &rdev->flags);
rdev->desc_nr = -1;
rdev->saved_raid_disk = -1;
err = bind_rdev_to_array(rdev, mddev);
if (err)
goto abort_export;
/*
* The rest should better be atomic, we can have disk failures
* noticed in interrupt contexts ...
*/
rdev->raid_disk = -1;
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
if (!mddev->thread)
md_update_sb(mddev, 1);
/*
* If the new disk does not support REQ_NOWAIT,
* disable on the whole MD.
*/
if (!bdev_nowait(rdev->bdev)) {
pr_info("%s: Disabling nowait because %pg does not support nowait\n",
mdname(mddev), rdev->bdev);
blk_queue_flag_clear(QUEUE_FLAG_NOWAIT, mddev->queue);
}
/*
* Kick recovery, maybe this spare has to be added to the
* array immediately.
*/
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
md_new_event();
return 0;
abort_export:
export_rdev(rdev, mddev);
return err;
}
static int set_bitmap_file(struct mddev *mddev, int fd)
{
int err = 0;
if (mddev->pers) {
if (!mddev->pers->quiesce || !mddev->thread)
return -EBUSY;
if (mddev->recovery || mddev->sync_thread)
return -EBUSY;
/* we should be able to change the bitmap.. */
}
if (fd >= 0) {
struct inode *inode;
struct file *f;
if (mddev->bitmap || mddev->bitmap_info.file)
return -EEXIST; /* cannot add when bitmap is present */
if (!IS_ENABLED(CONFIG_MD_BITMAP_FILE)) {
pr_warn("%s: bitmap files not supported by this kernel\n",
mdname(mddev));
return -EINVAL;
}
pr_warn("%s: using deprecated bitmap file support\n",
mdname(mddev));
f = fget(fd);
if (f == NULL) {
pr_warn("%s: error: failed to get bitmap file\n",
mdname(mddev));
return -EBADF;
}
inode = f->f_mapping->host;
if (!S_ISREG(inode->i_mode)) {
pr_warn("%s: error: bitmap file must be a regular file\n",
mdname(mddev));
err = -EBADF;
} else if (!(f->f_mode & FMODE_WRITE)) {
pr_warn("%s: error: bitmap file must open for write\n",
mdname(mddev));
err = -EBADF;
} else if (atomic_read(&inode->i_writecount) != 1) {
pr_warn("%s: error: bitmap file is already in use\n",
mdname(mddev));
err = -EBUSY;
}
if (err) {
fput(f);
return err;
}
mddev->bitmap_info.file = f;
mddev->bitmap_info.offset = 0; /* file overrides offset */
} else if (mddev->bitmap == NULL)
return -ENOENT; /* cannot remove what isn't there */
err = 0;
if (mddev->pers) {
if (fd >= 0) {
struct bitmap *bitmap;
bitmap = md_bitmap_create(mddev, -1);
mddev_suspend(mddev);
if (!IS_ERR(bitmap)) {
mddev->bitmap = bitmap;
err = md_bitmap_load(mddev);
} else
err = PTR_ERR(bitmap);
if (err) {
md_bitmap_destroy(mddev);
fd = -1;
}
mddev_resume(mddev);
} else if (fd < 0) {
mddev_suspend(mddev);
md_bitmap_destroy(mddev);
mddev_resume(mddev);
}
}
if (fd < 0) {
struct file *f = mddev->bitmap_info.file;
if (f) {
spin_lock(&mddev->lock);
mddev->bitmap_info.file = NULL;
spin_unlock(&mddev->lock);
fput(f);
}
}
return err;
}
/*
* md_set_array_info is used two different ways
* The original usage is when creating a new array.
* In this usage, raid_disks is > 0 and it together with
* level, size, not_persistent,layout,chunksize determine the
* shape of the array.
* This will always create an array with a type-0.90.0 superblock.
* The newer usage is when assembling an array.
* In this case raid_disks will be 0, and the major_version field is
* use to determine which style super-blocks are to be found on the devices.
* The minor and patch _version numbers are also kept incase the
* super_block handler wishes to interpret them.
*/
int md_set_array_info(struct mddev *mddev, struct mdu_array_info_s *info)
{
if (info->raid_disks == 0) {
/* just setting version number for superblock loading */
if (info->major_version < 0 ||
info->major_version >= ARRAY_SIZE(super_types) ||
super_types[info->major_version].name == NULL) {
/* maybe try to auto-load a module? */
pr_warn("md: superblock version %d not known\n",
info->major_version);
return -EINVAL;
}
mddev->major_version = info->major_version;
mddev->minor_version = info->minor_version;
mddev->patch_version = info->patch_version;
mddev->persistent = !info->not_persistent;
/* ensure mddev_put doesn't delete this now that there
* is some minimal configuration.
*/
mddev->ctime = ktime_get_real_seconds();
return 0;
}
mddev->major_version = MD_MAJOR_VERSION;
mddev->minor_version = MD_MINOR_VERSION;
mddev->patch_version = MD_PATCHLEVEL_VERSION;
mddev->ctime = ktime_get_real_seconds();
mddev->level = info->level;
mddev->clevel[0] = 0;
mddev->dev_sectors = 2 * (sector_t)info->size;
mddev->raid_disks = info->raid_disks;
/* don't set md_minor, it is determined by which /dev/md* was
* openned
*/
if (info->state & (1<<MD_SB_CLEAN))
mddev->recovery_cp = MaxSector;
else
mddev->recovery_cp = 0;
mddev->persistent = ! info->not_persistent;
mddev->external = 0;
mddev->layout = info->layout;
if (mddev->level == 0)
/* Cannot trust RAID0 layout info here */
mddev->layout = -1;
mddev->chunk_sectors = info->chunk_size >> 9;
if (mddev->persistent) {
mddev->max_disks = MD_SB_DISKS;
mddev->flags = 0;
mddev->sb_flags = 0;
}
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
mddev->bitmap_info.default_offset = MD_SB_BYTES >> 9;
mddev->bitmap_info.default_space = 64*2 - (MD_SB_BYTES >> 9);
mddev->bitmap_info.offset = 0;
mddev->reshape_position = MaxSector;
/*
* Generate a 128 bit UUID
*/
get_random_bytes(mddev->uuid, 16);
mddev->new_level = mddev->level;
mddev->new_chunk_sectors = mddev->chunk_sectors;
mddev->new_layout = mddev->layout;
mddev->delta_disks = 0;
mddev->reshape_backwards = 0;
return 0;
}
void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors)
{
lockdep_assert_held(&mddev->reconfig_mutex);
if (mddev->external_size)
return;
mddev->array_sectors = array_sectors;
}
EXPORT_SYMBOL(md_set_array_sectors);
static int update_size(struct mddev *mddev, sector_t num_sectors)
{
struct md_rdev *rdev;
int rv;
int fit = (num_sectors == 0);
sector_t old_dev_sectors = mddev->dev_sectors;
if (mddev->pers->resize == NULL)
return -EINVAL;
/* The "num_sectors" is the number of sectors of each device that
* is used. This can only make sense for arrays with redundancy.
* linear and raid0 always use whatever space is available. We can only
* consider changing this number if no resync or reconstruction is
* happening, and if the new size is acceptable. It must fit before the
* sb_start or, if that is <data_offset, it must fit before the size
* of each device. If num_sectors is zero, we find the largest size
* that fits.
*/
if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
mddev->sync_thread)
return -EBUSY;
if (!md_is_rdwr(mddev))
return -EROFS;
rdev_for_each(rdev, mddev) {
sector_t avail = rdev->sectors;
if (fit && (num_sectors == 0 || num_sectors > avail))
num_sectors = avail;
if (avail < num_sectors)
return -ENOSPC;
}
rv = mddev->pers->resize(mddev, num_sectors);
if (!rv) {
if (mddev_is_clustered(mddev))
md_cluster_ops->update_size(mddev, old_dev_sectors);
else if (mddev->queue) {
set_capacity_and_notify(mddev->gendisk,
mddev->array_sectors);
}
}
return rv;
}
static int update_raid_disks(struct mddev *mddev, int raid_disks)
{
int rv;
struct md_rdev *rdev;
/* change the number of raid disks */
if (mddev->pers->check_reshape == NULL)
return -EINVAL;
if (!md_is_rdwr(mddev))
return -EROFS;
if (raid_disks <= 0 ||
(mddev->max_disks && raid_disks >= mddev->max_disks))
return -EINVAL;
if (mddev->sync_thread ||
test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
test_bit(MD_RESYNCING_REMOTE, &mddev->recovery) ||
mddev->reshape_position != MaxSector)
return -EBUSY;
rdev_for_each(rdev, mddev) {
if (mddev->raid_disks < raid_disks &&
rdev->data_offset < rdev->new_data_offset)
return -EINVAL;
if (mddev->raid_disks > raid_disks &&
rdev->data_offset > rdev->new_data_offset)
return -EINVAL;
}
mddev->delta_disks = raid_disks - mddev->raid_disks;
if (mddev->delta_disks < 0)
mddev->reshape_backwards = 1;
else if (mddev->delta_disks > 0)
mddev->reshape_backwards = 0;
rv = mddev->pers->check_reshape(mddev);
if (rv < 0) {
mddev->delta_disks = 0;
mddev->reshape_backwards = 0;
}
return rv;
}
/*
* update_array_info is used to change the configuration of an
* on-line array.
* The version, ctime,level,size,raid_disks,not_persistent, layout,chunk_size
* fields in the info are checked against the array.
* Any differences that cannot be handled will cause an error.
* Normally, only one change can be managed at a time.
*/
static int update_array_info(struct mddev *mddev, mdu_array_info_t *info)
{
int rv = 0;
int cnt = 0;
int state = 0;
/* calculate expected state,ignoring low bits */
if (mddev->bitmap && mddev->bitmap_info.offset)
state |= (1 << MD_SB_BITMAP_PRESENT);
if (mddev->major_version != info->major_version ||
mddev->minor_version != info->minor_version ||
/* mddev->patch_version != info->patch_version || */
mddev->ctime != info->ctime ||
mddev->level != info->level ||
/* mddev->layout != info->layout || */
mddev->persistent != !info->not_persistent ||
mddev->chunk_sectors != info->chunk_size >> 9 ||
/* ignore bottom 8 bits of state, and allow SB_BITMAP_PRESENT to change */
((state^info->state) & 0xfffffe00)
)
return -EINVAL;
/* Check there is only one change */
if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
cnt++;
if (mddev->raid_disks != info->raid_disks)
cnt++;
if (mddev->layout != info->layout)
cnt++;
if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT))
cnt++;
if (cnt == 0)
return 0;
if (cnt > 1)
return -EINVAL;
if (mddev->layout != info->layout) {
/* Change layout
* we don't need to do anything at the md level, the
* personality will take care of it all.
*/
if (mddev->pers->check_reshape == NULL)
return -EINVAL;
else {
mddev->new_layout = info->layout;
rv = mddev->pers->check_reshape(mddev);
if (rv)
mddev->new_layout = mddev->layout;
return rv;
}
}
if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
rv = update_size(mddev, (sector_t)info->size * 2);
if (mddev->raid_disks != info->raid_disks)
rv = update_raid_disks(mddev, info->raid_disks);
if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) {
if (mddev->pers->quiesce == NULL || mddev->thread == NULL) {
rv = -EINVAL;
goto err;
}
if (mddev->recovery || mddev->sync_thread) {
rv = -EBUSY;
goto err;
}
if (info->state & (1<<MD_SB_BITMAP_PRESENT)) {
struct bitmap *bitmap;
/* add the bitmap */
if (mddev->bitmap) {
rv = -EEXIST;
goto err;
}
if (mddev->bitmap_info.default_offset == 0) {
rv = -EINVAL;
goto err;
}
mddev->bitmap_info.offset =
mddev->bitmap_info.default_offset;
mddev->bitmap_info.space =
mddev->bitmap_info.default_space;
bitmap = md_bitmap_create(mddev, -1);
mddev_suspend(mddev);
if (!IS_ERR(bitmap)) {
mddev->bitmap = bitmap;
rv = md_bitmap_load(mddev);
} else
rv = PTR_ERR(bitmap);
if (rv)
md_bitmap_destroy(mddev);
mddev_resume(mddev);
} else {
/* remove the bitmap */
if (!mddev->bitmap) {
rv = -ENOENT;
goto err;
}
if (mddev->bitmap->storage.file) {
rv = -EINVAL;
goto err;
}
if (mddev->bitmap_info.nodes) {
/* hold PW on all the bitmap lock */
if (md_cluster_ops->lock_all_bitmaps(mddev) <= 0) {
pr_warn("md: can't change bitmap to none since the array is in use by more than one node\n");
rv = -EPERM;
md_cluster_ops->unlock_all_bitmaps(mddev);
goto err;
}
mddev->bitmap_info.nodes = 0;
md_cluster_ops->leave(mddev);
module_put(md_cluster_mod);
mddev->safemode_delay = DEFAULT_SAFEMODE_DELAY;
}
mddev_suspend(mddev);
md_bitmap_destroy(mddev);
mddev_resume(mddev);
mddev->bitmap_info.offset = 0;
}
}
md_update_sb(mddev, 1);
return rv;
err:
return rv;
}
static int set_disk_faulty(struct mddev *mddev, dev_t dev)
{
struct md_rdev *rdev;
int err = 0;
if (mddev->pers == NULL)
return -ENODEV;
rcu_read_lock();
rdev = md_find_rdev_rcu(mddev, dev);
if (!rdev)
err = -ENODEV;
else {
md_error(mddev, rdev);
if (test_bit(MD_BROKEN, &mddev->flags))
err = -EBUSY;
}
rcu_read_unlock();
return err;
}
/*
* We have a problem here : there is no easy way to give a CHS
* virtual geometry. We currently pretend that we have a 2 heads
* 4 sectors (with a BIG number of cylinders...). This drives
* dosfs just mad... ;-)
*/
static int md_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
struct mddev *mddev = bdev->bd_disk->private_data;
geo->heads = 2;
geo->sectors = 4;
geo->cylinders = mddev->array_sectors / 8;
return 0;
}
static inline bool md_ioctl_valid(unsigned int cmd)
{
switch (cmd) {
case ADD_NEW_DISK:
case GET_ARRAY_INFO:
case GET_BITMAP_FILE:
case GET_DISK_INFO:
case HOT_ADD_DISK:
case HOT_REMOVE_DISK:
case RAID_VERSION:
case RESTART_ARRAY_RW:
case RUN_ARRAY:
case SET_ARRAY_INFO:
case SET_BITMAP_FILE:
case SET_DISK_FAULTY:
case STOP_ARRAY:
case STOP_ARRAY_RO:
case CLUSTERED_DISK_NACK:
return true;
default:
return false;
}
}
static int __md_set_array_info(struct mddev *mddev, void __user *argp)
{
mdu_array_info_t info;
int err;
if (!argp)
memset(&info, 0, sizeof(info));
else if (copy_from_user(&info, argp, sizeof(info)))
return -EFAULT;
if (mddev->pers) {
err = update_array_info(mddev, &info);
if (err)
pr_warn("md: couldn't update array info. %d\n", err);
return err;
}
if (!list_empty(&mddev->disks)) {
pr_warn("md: array %s already has disks!\n", mdname(mddev));
return -EBUSY;
}
if (mddev->raid_disks) {
pr_warn("md: array %s already initialised!\n", mdname(mddev));
return -EBUSY;
}
err = md_set_array_info(mddev, &info);
if (err)
pr_warn("md: couldn't set array info. %d\n", err);
return err;
}
static int md_ioctl(struct block_device *bdev, blk_mode_t mode,
unsigned int cmd, unsigned long arg)
{
int err = 0;
void __user *argp = (void __user *)arg;
struct mddev *mddev = NULL;
bool did_set_md_closing = false;
if (!md_ioctl_valid(cmd))
return -ENOTTY;
switch (cmd) {
case RAID_VERSION:
case GET_ARRAY_INFO:
case GET_DISK_INFO:
break;
default:
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
}
/*
* Commands dealing with the RAID driver but not any
* particular array:
*/
switch (cmd) {
case RAID_VERSION:
err = get_version(argp);
goto out;
default:;
}
/*
* Commands creating/starting a new array:
*/
mddev = bdev->bd_disk->private_data;
if (!mddev) {
BUG();
goto out;
}
/* Some actions do not requires the mutex */
switch (cmd) {
case GET_ARRAY_INFO:
if (!mddev->raid_disks && !mddev->external)
err = -ENODEV;
else
err = get_array_info(mddev, argp);
goto out;
case GET_DISK_INFO:
if (!mddev->raid_disks && !mddev->external)
err = -ENODEV;
else
err = get_disk_info(mddev, argp);
goto out;
case SET_DISK_FAULTY:
err = set_disk_faulty(mddev, new_decode_dev(arg));
goto out;
case GET_BITMAP_FILE:
err = get_bitmap_file(mddev, argp);
goto out;
}
if (cmd == HOT_REMOVE_DISK)
/* need to ensure recovery thread has run */
wait_event_interruptible_timeout(mddev->sb_wait,
!test_bit(MD_RECOVERY_NEEDED,
&mddev->recovery),
msecs_to_jiffies(5000));
if (cmd == STOP_ARRAY || cmd == STOP_ARRAY_RO) {
/* Need to flush page cache, and ensure no-one else opens
* and writes
*/
mutex_lock(&mddev->open_mutex);
if (mddev->pers && atomic_read(&mddev->openers) > 1) {
mutex_unlock(&mddev->open_mutex);
err = -EBUSY;
goto out;
}
if (test_and_set_bit(MD_CLOSING, &mddev->flags)) {
mutex_unlock(&mddev->open_mutex);
err = -EBUSY;
goto out;
}
did_set_md_closing = true;
mutex_unlock(&mddev->open_mutex);
sync_blockdev(bdev);
}
err = mddev_lock(mddev);
if (err) {
pr_debug("md: ioctl lock interrupted, reason %d, cmd %d\n",
err, cmd);
goto out;
}
if (cmd == SET_ARRAY_INFO) {
err = __md_set_array_info(mddev, argp);
goto unlock;
}
/*
* Commands querying/configuring an existing array:
*/
/* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
* RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
if ((!mddev->raid_disks && !mddev->external)
&& cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
&& cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
&& cmd != GET_BITMAP_FILE) {
err = -ENODEV;
goto unlock;
}
/*
* Commands even a read-only array can execute:
*/
switch (cmd) {
case RESTART_ARRAY_RW:
err = restart_array(mddev);
goto unlock;
case STOP_ARRAY:
err = do_md_stop(mddev, 0, bdev);
goto unlock;
case STOP_ARRAY_RO:
err = md_set_readonly(mddev, bdev);
goto unlock;
case HOT_REMOVE_DISK:
err = hot_remove_disk(mddev, new_decode_dev(arg));
goto unlock;
case ADD_NEW_DISK:
/* We can support ADD_NEW_DISK on read-only arrays
* only if we are re-adding a preexisting device.
* So require mddev->pers and MD_DISK_SYNC.
*/
if (mddev->pers) {
mdu_disk_info_t info;
if (copy_from_user(&info, argp, sizeof(info)))
err = -EFAULT;
else if (!(info.state & (1<<MD_DISK_SYNC)))
/* Need to clear read-only for this */
break;
else
err = md_add_new_disk(mddev, &info);
goto unlock;
}
break;
}
/*
* The remaining ioctls are changing the state of the
* superblock, so we do not allow them on read-only arrays.
*/
if (!md_is_rdwr(mddev) && mddev->pers) {
if (mddev->ro != MD_AUTO_READ) {
err = -EROFS;
goto unlock;
}
mddev->ro = MD_RDWR;
sysfs_notify_dirent_safe(mddev->sysfs_state);
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
/* mddev_unlock will wake thread */
/* If a device failed while we were read-only, we
* need to make sure the metadata is updated now.
*/
if (test_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags)) {
mddev_unlock(mddev);
wait_event(mddev->sb_wait,
!test_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags) &&
!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
mddev_lock_nointr(mddev);
}
}
switch (cmd) {
case ADD_NEW_DISK:
{
mdu_disk_info_t info;
if (copy_from_user(&info, argp, sizeof(info)))
err = -EFAULT;
else
err = md_add_new_disk(mddev, &info);
goto unlock;
}
case CLUSTERED_DISK_NACK:
if (mddev_is_clustered(mddev))
md_cluster_ops->new_disk_ack(mddev, false);
else
err = -EINVAL;
goto unlock;
case HOT_ADD_DISK:
err = hot_add_disk(mddev, new_decode_dev(arg));
goto unlock;
case RUN_ARRAY:
err = do_md_run(mddev);
goto unlock;
case SET_BITMAP_FILE:
err = set_bitmap_file(mddev, (int)arg);
goto unlock;
default:
err = -EINVAL;
goto unlock;
}
unlock:
if (mddev->hold_active == UNTIL_IOCTL &&
err != -EINVAL)
mddev->hold_active = 0;
mddev_unlock(mddev);
out:
if(did_set_md_closing)
clear_bit(MD_CLOSING, &mddev->flags);
return err;
}
#ifdef CONFIG_COMPAT
static int md_compat_ioctl(struct block_device *bdev, blk_mode_t mode,
unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case HOT_REMOVE_DISK:
case HOT_ADD_DISK:
case SET_DISK_FAULTY:
case SET_BITMAP_FILE:
/* These take in integer arg, do not convert */
break;
default:
arg = (unsigned long)compat_ptr(arg);
break;
}
return md_ioctl(bdev, mode, cmd, arg);
}
#endif /* CONFIG_COMPAT */
static int md_set_read_only(struct block_device *bdev, bool ro)
{
struct mddev *mddev = bdev->bd_disk->private_data;
int err;
err = mddev_lock(mddev);
if (err)
return err;
if (!mddev->raid_disks && !mddev->external) {
err = -ENODEV;
goto out_unlock;
}
/*
* Transitioning to read-auto need only happen for arrays that call
* md_write_start and which are not ready for writes yet.
*/
if (!ro && mddev->ro == MD_RDONLY && mddev->pers) {
err = restart_array(mddev);
if (err)
goto out_unlock;
mddev->ro = MD_AUTO_READ;
}
out_unlock:
mddev_unlock(mddev);
return err;
}
static int md_open(struct gendisk *disk, blk_mode_t mode)
{
struct mddev *mddev;
int err;
spin_lock(&all_mddevs_lock);
mddev = mddev_get(disk->private_data);
spin_unlock(&all_mddevs_lock);
if (!mddev)
return -ENODEV;
err = mutex_lock_interruptible(&mddev->open_mutex);
if (err)
goto out;
err = -ENODEV;
if (test_bit(MD_CLOSING, &mddev->flags))
goto out_unlock;
atomic_inc(&mddev->openers);
mutex_unlock(&mddev->open_mutex);
disk_check_media_change(disk);
return 0;
out_unlock:
mutex_unlock(&mddev->open_mutex);
out:
mddev_put(mddev);
return err;
}
static void md_release(struct gendisk *disk)
{
struct mddev *mddev = disk->private_data;
BUG_ON(!mddev);
atomic_dec(&mddev->openers);
mddev_put(mddev);
}
static unsigned int md_check_events(struct gendisk *disk, unsigned int clearing)
{
struct mddev *mddev = disk->private_data;
unsigned int ret = 0;
if (mddev->changed)
ret = DISK_EVENT_MEDIA_CHANGE;
mddev->changed = 0;
return ret;
}
static void md_free_disk(struct gendisk *disk)
{
struct mddev *mddev = disk->private_data;
percpu_ref_exit(&mddev->writes_pending);
mddev_free(mddev);
}
const struct block_device_operations md_fops =
{
.owner = THIS_MODULE,
.submit_bio = md_submit_bio,
.open = md_open,
.release = md_release,
.ioctl = md_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = md_compat_ioctl,
#endif
.getgeo = md_getgeo,
.check_events = md_check_events,
.set_read_only = md_set_read_only,
.free_disk = md_free_disk,
};
static int md_thread(void *arg)
{
struct md_thread *thread = arg;
/*
* md_thread is a 'system-thread', it's priority should be very
* high. We avoid resource deadlocks individually in each
* raid personality. (RAID5 does preallocation) We also use RR and
* the very same RT priority as kswapd, thus we will never get
* into a priority inversion deadlock.
*
* we definitely have to have equal or higher priority than
* bdflush, otherwise bdflush will deadlock if there are too
* many dirty RAID5 blocks.
*/
allow_signal(SIGKILL);
while (!kthread_should_stop()) {
/* We need to wait INTERRUPTIBLE so that
* we don't add to the load-average.
* That means we need to be sure no signals are
* pending
*/
if (signal_pending(current))
flush_signals(current);
wait_event_interruptible_timeout
(thread->wqueue,
test_bit(THREAD_WAKEUP, &thread->flags)
|| kthread_should_stop() || kthread_should_park(),
thread->timeout);
clear_bit(THREAD_WAKEUP, &thread->flags);
if (kthread_should_park())
kthread_parkme();
if (!kthread_should_stop())
thread->run(thread);
}
return 0;
}
static void md_wakeup_thread_directly(struct md_thread __rcu *thread)
{
struct md_thread *t;
rcu_read_lock();
t = rcu_dereference(thread);
if (t)
wake_up_process(t->tsk);
rcu_read_unlock();
}
void md_wakeup_thread(struct md_thread __rcu *thread)
{
struct md_thread *t;
rcu_read_lock();
t = rcu_dereference(thread);
if (t) {
pr_debug("md: waking up MD thread %s.\n", t->tsk->comm);
set_bit(THREAD_WAKEUP, &t->flags);
wake_up(&t->wqueue);
}
rcu_read_unlock();
}
EXPORT_SYMBOL(md_wakeup_thread);
struct md_thread *md_register_thread(void (*run) (struct md_thread *),
struct mddev *mddev, const char *name)
{
struct md_thread *thread;
thread = kzalloc(sizeof(struct md_thread), GFP_KERNEL);
if (!thread)
return NULL;
init_waitqueue_head(&thread->wqueue);
thread->run = run;
thread->mddev = mddev;
thread->timeout = MAX_SCHEDULE_TIMEOUT;
thread->tsk = kthread_run(md_thread, thread,
"%s_%s",
mdname(thread->mddev),
name);
if (IS_ERR(thread->tsk)) {
kfree(thread);
return NULL;
}
return thread;
}
EXPORT_SYMBOL(md_register_thread);
void md_unregister_thread(struct mddev *mddev, struct md_thread __rcu **threadp)
{
struct md_thread *thread = rcu_dereference_protected(*threadp,
lockdep_is_held(&mddev->reconfig_mutex));
if (!thread)
return;
rcu_assign_pointer(*threadp, NULL);
synchronize_rcu();
pr_debug("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
kthread_stop(thread->tsk);
kfree(thread);
}
EXPORT_SYMBOL(md_unregister_thread);
void md_error(struct mddev *mddev, struct md_rdev *rdev)
{
if (!rdev || test_bit(Faulty, &rdev->flags))
return;
if (!mddev->pers || !mddev->pers->error_handler)
return;
mddev->pers->error_handler(mddev, rdev);
if (mddev->pers->level == 0 || mddev->pers->level == LEVEL_LINEAR)
return;
if (mddev->degraded && !test_bit(MD_BROKEN, &mddev->flags))
set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
sysfs_notify_dirent_safe(rdev->sysfs_state);
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
if (!test_bit(MD_BROKEN, &mddev->flags)) {
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
}
if (mddev->event_work.func)
queue_work(md_misc_wq, &mddev->event_work);
md_new_event();
}
EXPORT_SYMBOL(md_error);
/* seq_file implementation /proc/mdstat */
static void status_unused(struct seq_file *seq)
{
int i = 0;
struct md_rdev *rdev;
seq_printf(seq, "unused devices: ");
list_for_each_entry(rdev, &pending_raid_disks, same_set) {
i++;
seq_printf(seq, "%pg ", rdev->bdev);
}
if (!i)
seq_printf(seq, "<none>");
seq_printf(seq, "\n");
}
static int status_resync(struct seq_file *seq, struct mddev *mddev)
{
sector_t max_sectors, resync, res;
unsigned long dt, db = 0;
sector_t rt, curr_mark_cnt, resync_mark_cnt;
int scale, recovery_active;
unsigned int per_milli;
if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
max_sectors = mddev->resync_max_sectors;
else
max_sectors = mddev->dev_sectors;
resync = mddev->curr_resync;
if (resync < MD_RESYNC_ACTIVE) {
if (test_bit(MD_RECOVERY_DONE, &mddev->recovery))
/* Still cleaning up */
resync = max_sectors;
} else if (resync > max_sectors) {
resync = max_sectors;
} else {
res = atomic_read(&mddev->recovery_active);
/*
* Resync has started, but the subtraction has overflowed or
* yielded one of the special values. Force it to active to
* ensure the status reports an active resync.
*/
if (resync < res || resync - res < MD_RESYNC_ACTIVE)
resync = MD_RESYNC_ACTIVE;
else
resync -= res;
}
if (resync == MD_RESYNC_NONE) {
if (test_bit(MD_RESYNCING_REMOTE, &mddev->recovery)) {
struct md_rdev *rdev;
rdev_for_each(rdev, mddev)
if (rdev->raid_disk >= 0 &&
!test_bit(Faulty, &rdev->flags) &&
rdev->recovery_offset != MaxSector &&
rdev->recovery_offset) {
seq_printf(seq, "\trecover=REMOTE");
return 1;
}
if (mddev->reshape_position != MaxSector)
seq_printf(seq, "\treshape=REMOTE");
else
seq_printf(seq, "\tresync=REMOTE");
return 1;
}
if (mddev->recovery_cp < MaxSector) {
seq_printf(seq, "\tresync=PENDING");
return 1;
}
return 0;
}
if (resync < MD_RESYNC_ACTIVE) {
seq_printf(seq, "\tresync=DELAYED");
return 1;
}
WARN_ON(max_sectors == 0);
/* Pick 'scale' such that (resync>>scale)*1000 will fit
* in a sector_t, and (max_sectors>>scale) will fit in a
* u32, as those are the requirements for sector_div.
* Thus 'scale' must be at least 10
*/
scale = 10;
if (sizeof(sector_t) > sizeof(unsigned long)) {
while ( max_sectors/2 > (1ULL<<(scale+32)))
scale++;
}
res = (resync>>scale)*1000;
sector_div(res, (u32)((max_sectors>>scale)+1));
per_milli = res;
{
int i, x = per_milli/50, y = 20-x;
seq_printf(seq, "[");
for (i = 0; i < x; i++)
seq_printf(seq, "=");
seq_printf(seq, ">");
for (i = 0; i < y; i++)
seq_printf(seq, ".");
seq_printf(seq, "] ");
}
seq_printf(seq, " %s =%3u.%u%% (%llu/%llu)",
(test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)?
"reshape" :
(test_bit(MD_RECOVERY_CHECK, &mddev->recovery)?
"check" :
(test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
"resync" : "recovery"))),
per_milli/10, per_milli % 10,
(unsigned long long) resync/2,
(unsigned long long) max_sectors/2);
/*
* dt: time from mark until now
* db: blocks written from mark until now
* rt: remaining time
*
* rt is a sector_t, which is always 64bit now. We are keeping
* the original algorithm, but it is not really necessary.
*
* Original algorithm:
* So we divide before multiply in case it is 32bit and close
* to the limit.
* We scale the divisor (db) by 32 to avoid losing precision
* near the end of resync when the number of remaining sectors
* is close to 'db'.
* We then divide rt by 32 after multiplying by db to compensate.
* The '+1' avoids division by zero if db is very small.
*/
dt = ((jiffies - mddev->resync_mark) / HZ);
if (!dt) dt++;
curr_mark_cnt = mddev->curr_mark_cnt;
recovery_active = atomic_read(&mddev->recovery_active);
resync_mark_cnt = mddev->resync_mark_cnt;
if (curr_mark_cnt >= (recovery_active + resync_mark_cnt))
db = curr_mark_cnt - (recovery_active + resync_mark_cnt);
rt = max_sectors - resync; /* number of remaining sectors */
rt = div64_u64(rt, db/32+1);
rt *= dt;
rt >>= 5;
seq_printf(seq, " finish=%lu.%lumin", (unsigned long)rt / 60,
((unsigned long)rt % 60)/6);
seq_printf(seq, " speed=%ldK/sec", db/2/dt);
return 1;
}
static void *md_seq_start(struct seq_file *seq, loff_t *pos)
{
struct list_head *tmp;
loff_t l = *pos;
struct mddev *mddev;
if (l == 0x10000) {
++*pos;
return (void *)2;
}
if (l > 0x10000)
return NULL;
if (!l--)
/* header */
return (void*)1;
spin_lock(&all_mddevs_lock);
list_for_each(tmp,&all_mddevs)
if (!l--) {
mddev = list_entry(tmp, struct mddev, all_mddevs);
if (!mddev_get(mddev))
continue;
spin_unlock(&all_mddevs_lock);
return mddev;
}
spin_unlock(&all_mddevs_lock);
if (!l--)
return (void*)2;/* tail */
return NULL;
}
static void *md_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct list_head *tmp;
struct mddev *next_mddev, *mddev = v;
struct mddev *to_put = NULL;
++*pos;
if (v == (void*)2)
return NULL;
spin_lock(&all_mddevs_lock);
if (v == (void*)1) {
tmp = all_mddevs.next;
} else {
to_put = mddev;
tmp = mddev->all_mddevs.next;
}
for (;;) {
if (tmp == &all_mddevs) {
next_mddev = (void*)2;
*pos = 0x10000;
break;
}
next_mddev = list_entry(tmp, struct mddev, all_mddevs);
if (mddev_get(next_mddev))
break;
mddev = next_mddev;
tmp = mddev->all_mddevs.next;
}
spin_unlock(&all_mddevs_lock);
if (to_put)
mddev_put(to_put);
return next_mddev;
}
static void md_seq_stop(struct seq_file *seq, void *v)
{
struct mddev *mddev = v;
if (mddev && v != (void*)1 && v != (void*)2)
mddev_put(mddev);
}
static int md_seq_show(struct seq_file *seq, void *v)
{
struct mddev *mddev = v;
sector_t sectors;
struct md_rdev *rdev;
if (v == (void*)1) {
struct md_personality *pers;
seq_printf(seq, "Personalities : ");
spin_lock(&pers_lock);
list_for_each_entry(pers, &pers_list, list)
seq_printf(seq, "[%s] ", pers->name);
spin_unlock(&pers_lock);
seq_printf(seq, "\n");
seq->poll_event = atomic_read(&md_event_count);
return 0;
}
if (v == (void*)2) {
status_unused(seq);
return 0;
}
spin_lock(&mddev->lock);
if (mddev->pers || mddev->raid_disks || !list_empty(&mddev->disks)) {
seq_printf(seq, "%s : %sactive", mdname(mddev),
mddev->pers ? "" : "in");
if (mddev->pers) {
if (mddev->ro == MD_RDONLY)
seq_printf(seq, " (read-only)");
if (mddev->ro == MD_AUTO_READ)
seq_printf(seq, " (auto-read-only)");
seq_printf(seq, " %s", mddev->pers->name);
}
sectors = 0;
rcu_read_lock();
rdev_for_each_rcu(rdev, mddev) {
seq_printf(seq, " %pg[%d]", rdev->bdev, rdev->desc_nr);
if (test_bit(WriteMostly, &rdev->flags))
seq_printf(seq, "(W)");
if (test_bit(Journal, &rdev->flags))
seq_printf(seq, "(J)");
if (test_bit(Faulty, &rdev->flags)) {
seq_printf(seq, "(F)");
continue;
}
if (rdev->raid_disk < 0)
seq_printf(seq, "(S)"); /* spare */
if (test_bit(Replacement, &rdev->flags))
seq_printf(seq, "(R)");
sectors += rdev->sectors;
}
rcu_read_unlock();
if (!list_empty(&mddev->disks)) {
if (mddev->pers)
seq_printf(seq, "\n %llu blocks",
(unsigned long long)
mddev->array_sectors / 2);
else
seq_printf(seq, "\n %llu blocks",
(unsigned long long)sectors / 2);
}
if (mddev->persistent) {
if (mddev->major_version != 0 ||
mddev->minor_version != 90) {
seq_printf(seq," super %d.%d",
mddev->major_version,
mddev->minor_version);
}
} else if (mddev->external)
seq_printf(seq, " super external:%s",
mddev->metadata_type);
else
seq_printf(seq, " super non-persistent");
if (mddev->pers) {
mddev->pers->status(seq, mddev);
seq_printf(seq, "\n ");
if (mddev->pers->sync_request) {
if (status_resync(seq, mddev))
seq_printf(seq, "\n ");
}
} else
seq_printf(seq, "\n ");
md_bitmap_status(seq, mddev->bitmap);
seq_printf(seq, "\n");
}
spin_unlock(&mddev->lock);
return 0;
}
static const struct seq_operations md_seq_ops = {
.start = md_seq_start,
.next = md_seq_next,
.stop = md_seq_stop,
.show = md_seq_show,
};
static int md_seq_open(struct inode *inode, struct file *file)
{
struct seq_file *seq;
int error;
error = seq_open(file, &md_seq_ops);
if (error)
return error;
seq = file->private_data;
seq->poll_event = atomic_read(&md_event_count);
return error;
}
static int md_unloading;
static __poll_t mdstat_poll(struct file *filp, poll_table *wait)
{
struct seq_file *seq = filp->private_data;
__poll_t mask;
if (md_unloading)
return EPOLLIN|EPOLLRDNORM|EPOLLERR|EPOLLPRI;
poll_wait(filp, &md_event_waiters, wait);
/* always allow read */
mask = EPOLLIN | EPOLLRDNORM;
if (seq->poll_event != atomic_read(&md_event_count))
mask |= EPOLLERR | EPOLLPRI;
return mask;
}
static const struct proc_ops mdstat_proc_ops = {
.proc_open = md_seq_open,
.proc_read = seq_read,
.proc_lseek = seq_lseek,
.proc_release = seq_release,
.proc_poll = mdstat_poll,
};
int register_md_personality(struct md_personality *p)
{
pr_debug("md: %s personality registered for level %d\n",
p->name, p->level);
spin_lock(&pers_lock);
list_add_tail(&p->list, &pers_list);
spin_unlock(&pers_lock);
return 0;
}
EXPORT_SYMBOL(register_md_personality);
int unregister_md_personality(struct md_personality *p)
{
pr_debug("md: %s personality unregistered\n", p->name);
spin_lock(&pers_lock);
list_del_init(&p->list);
spin_unlock(&pers_lock);
return 0;
}
EXPORT_SYMBOL(unregister_md_personality);
int register_md_cluster_operations(struct md_cluster_operations *ops,
struct module *module)
{
int ret = 0;
spin_lock(&pers_lock);
if (md_cluster_ops != NULL)
ret = -EALREADY;
else {
md_cluster_ops = ops;
md_cluster_mod = module;
}
spin_unlock(&pers_lock);
return ret;
}
EXPORT_SYMBOL(register_md_cluster_operations);
int unregister_md_cluster_operations(void)
{
spin_lock(&pers_lock);
md_cluster_ops = NULL;
spin_unlock(&pers_lock);
return 0;
}
EXPORT_SYMBOL(unregister_md_cluster_operations);
int md_setup_cluster(struct mddev *mddev, int nodes)
{
int ret;
if (!md_cluster_ops)
request_module("md-cluster");
spin_lock(&pers_lock);
/* ensure module won't be unloaded */
if (!md_cluster_ops || !try_module_get(md_cluster_mod)) {
pr_warn("can't find md-cluster module or get its reference.\n");
spin_unlock(&pers_lock);
return -ENOENT;
}
spin_unlock(&pers_lock);
ret = md_cluster_ops->join(mddev, nodes);
if (!ret)
mddev->safemode_delay = 0;
return ret;
}
void md_cluster_stop(struct mddev *mddev)
{
if (!md_cluster_ops)
return;
md_cluster_ops->leave(mddev);
module_put(md_cluster_mod);
}
static int is_mddev_idle(struct mddev *mddev, int init)
{
struct md_rdev *rdev;
int idle;
int curr_events;
idle = 1;
rcu_read_lock();
rdev_for_each_rcu(rdev, mddev) {
struct gendisk *disk = rdev->bdev->bd_disk;
curr_events = (int)part_stat_read_accum(disk->part0, sectors) -
atomic_read(&disk->sync_io);
/* sync IO will cause sync_io to increase before the disk_stats
* as sync_io is counted when a request starts, and
* disk_stats is counted when it completes.
* So resync activity will cause curr_events to be smaller than
* when there was no such activity.
* non-sync IO will cause disk_stat to increase without
* increasing sync_io so curr_events will (eventually)
* be larger than it was before. Once it becomes
* substantially larger, the test below will cause
* the array to appear non-idle, and resync will slow
* down.
* If there is a lot of outstanding resync activity when
* we set last_event to curr_events, then all that activity
* completing might cause the array to appear non-idle
* and resync will be slowed down even though there might
* not have been non-resync activity. This will only
* happen once though. 'last_events' will soon reflect
* the state where there is little or no outstanding
* resync requests, and further resync activity will
* always make curr_events less than last_events.
*
*/
if (init || curr_events - rdev->last_events > 64) {
rdev->last_events = curr_events;
idle = 0;
}
}
rcu_read_unlock();
return idle;
}
void md_done_sync(struct mddev *mddev, int blocks, int ok)
{
/* another "blocks" (512byte) blocks have been synced */
atomic_sub(blocks, &mddev->recovery_active);
wake_up(&mddev->recovery_wait);
if (!ok) {
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
set_bit(MD_RECOVERY_ERROR, &mddev->recovery);
md_wakeup_thread(mddev->thread);
// stop recovery, signal do_sync ....
}
}
EXPORT_SYMBOL(md_done_sync);
/* md_write_start(mddev, bi)
* If we need to update some array metadata (e.g. 'active' flag
* in superblock) before writing, schedule a superblock update
* and wait for it to complete.
* A return value of 'false' means that the write wasn't recorded
* and cannot proceed as the array is being suspend.
*/
bool md_write_start(struct mddev *mddev, struct bio *bi)
{
int did_change = 0;
if (bio_data_dir(bi) != WRITE)
return true;
BUG_ON(mddev->ro == MD_RDONLY);
if (mddev->ro == MD_AUTO_READ) {
/* need to switch to read/write */
mddev->ro = MD_RDWR;
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
md_wakeup_thread(mddev->sync_thread);
did_change = 1;
}
rcu_read_lock();
percpu_ref_get(&mddev->writes_pending);
smp_mb(); /* Match smp_mb in set_in_sync() */
if (mddev->safemode == 1)
mddev->safemode = 0;
/* sync_checkers is always 0 when writes_pending is in per-cpu mode */
if (mddev->in_sync || mddev->sync_checkers) {
spin_lock(&mddev->lock);
if (mddev->in_sync) {
mddev->in_sync = 0;
set_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
set_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags);
md_wakeup_thread(mddev->thread);
did_change = 1;
}
spin_unlock(&mddev->lock);
}
rcu_read_unlock();
if (did_change)
sysfs_notify_dirent_safe(mddev->sysfs_state);
if (!mddev->has_superblocks)
return true;
wait_event(mddev->sb_wait,
!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags) ||
is_md_suspended(mddev));
if (test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
percpu_ref_put(&mddev->writes_pending);
return false;
}
return true;
}
EXPORT_SYMBOL(md_write_start);
/* md_write_inc can only be called when md_write_start() has
* already been called at least once of the current request.
* It increments the counter and is useful when a single request
* is split into several parts. Each part causes an increment and
* so needs a matching md_write_end().
* Unlike md_write_start(), it is safe to call md_write_inc() inside
* a spinlocked region.
*/
void md_write_inc(struct mddev *mddev, struct bio *bi)
{
if (bio_data_dir(bi) != WRITE)
return;
WARN_ON_ONCE(mddev->in_sync || !md_is_rdwr(mddev));
percpu_ref_get(&mddev->writes_pending);
}
EXPORT_SYMBOL(md_write_inc);
void md_write_end(struct mddev *mddev)
{
percpu_ref_put(&mddev->writes_pending);
if (mddev->safemode == 2)
md_wakeup_thread(mddev->thread);
else if (mddev->safemode_delay)
/* The roundup() ensures this only performs locking once
* every ->safemode_delay jiffies
*/
mod_timer(&mddev->safemode_timer,
roundup(jiffies, mddev->safemode_delay) +
mddev->safemode_delay);
}
EXPORT_SYMBOL(md_write_end);
/* This is used by raid0 and raid10 */
void md_submit_discard_bio(struct mddev *mddev, struct md_rdev *rdev,
struct bio *bio, sector_t start, sector_t size)
{
struct bio *discard_bio = NULL;
if (__blkdev_issue_discard(rdev->bdev, start, size, GFP_NOIO,
&discard_bio) || !discard_bio)
return;
bio_chain(discard_bio, bio);
bio_clone_blkg_association(discard_bio, bio);
if (mddev->gendisk)
trace_block_bio_remap(discard_bio,
disk_devt(mddev->gendisk),
bio->bi_iter.bi_sector);
submit_bio_noacct(discard_bio);
}
EXPORT_SYMBOL_GPL(md_submit_discard_bio);
static void md_end_clone_io(struct bio *bio)
{
struct md_io_clone *md_io_clone = bio->bi_private;
struct bio *orig_bio = md_io_clone->orig_bio;
struct mddev *mddev = md_io_clone->mddev;
orig_bio->bi_status = bio->bi_status;
if (md_io_clone->start_time)
bio_end_io_acct(orig_bio, md_io_clone->start_time);
bio_put(bio);
bio_endio(orig_bio);
percpu_ref_put(&mddev->active_io);
}
static void md_clone_bio(struct mddev *mddev, struct bio **bio)
{
struct block_device *bdev = (*bio)->bi_bdev;
struct md_io_clone *md_io_clone;
struct bio *clone =
bio_alloc_clone(bdev, *bio, GFP_NOIO, &mddev->io_clone_set);
md_io_clone = container_of(clone, struct md_io_clone, bio_clone);
md_io_clone->orig_bio = *bio;
md_io_clone->mddev = mddev;
if (blk_queue_io_stat(bdev->bd_disk->queue))
md_io_clone->start_time = bio_start_io_acct(*bio);
clone->bi_end_io = md_end_clone_io;
clone->bi_private = md_io_clone;
*bio = clone;
}
void md_account_bio(struct mddev *mddev, struct bio **bio)
{
percpu_ref_get(&mddev->active_io);
md_clone_bio(mddev, bio);
}
EXPORT_SYMBOL_GPL(md_account_bio);
/* md_allow_write(mddev)
* Calling this ensures that the array is marked 'active' so that writes
* may proceed without blocking. It is important to call this before
* attempting a GFP_KERNEL allocation while holding the mddev lock.
* Must be called with mddev_lock held.
*/
void md_allow_write(struct mddev *mddev)
{
if (!mddev->pers)
return;
if (!md_is_rdwr(mddev))
return;
if (!mddev->pers->sync_request)
return;
spin_lock(&mddev->lock);
if (mddev->in_sync) {
mddev->in_sync = 0;
set_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
set_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags);
if (mddev->safemode_delay &&
mddev->safemode == 0)
mddev->safemode = 1;
spin_unlock(&mddev->lock);
md_update_sb(mddev, 0);
sysfs_notify_dirent_safe(mddev->sysfs_state);
/* wait for the dirty state to be recorded in the metadata */
wait_event(mddev->sb_wait,
!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
} else
spin_unlock(&mddev->lock);
}
EXPORT_SYMBOL_GPL(md_allow_write);
#define SYNC_MARKS 10
#define SYNC_MARK_STEP (3*HZ)
#define UPDATE_FREQUENCY (5*60*HZ)
void md_do_sync(struct md_thread *thread)
{
struct mddev *mddev = thread->mddev;
struct mddev *mddev2;
unsigned int currspeed = 0, window;
sector_t max_sectors,j, io_sectors, recovery_done;
unsigned long mark[SYNC_MARKS];
unsigned long update_time;
sector_t mark_cnt[SYNC_MARKS];
int last_mark,m;
sector_t last_check;
int skipped = 0;
struct md_rdev *rdev;
char *desc, *action = NULL;
struct blk_plug plug;
int ret;
/* just incase thread restarts... */
if (test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
test_bit(MD_RECOVERY_WAIT, &mddev->recovery))
return;
if (!md_is_rdwr(mddev)) {/* never try to sync a read-only array */
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
return;
}
if (mddev_is_clustered(mddev)) {
ret = md_cluster_ops->resync_start(mddev);
if (ret)
goto skip;
set_bit(MD_CLUSTER_RESYNC_LOCKED, &mddev->flags);
if (!(test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) ||
test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
&& ((unsigned long long)mddev->curr_resync_completed
< (unsigned long long)mddev->resync_max_sectors))
goto skip;
}
if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
desc = "data-check";
action = "check";
} else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
desc = "requested-resync";
action = "repair";
} else
desc = "resync";
} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
desc = "reshape";
else
desc = "recovery";
mddev->last_sync_action = action ?: desc;
/*
* Before starting a resync we must have set curr_resync to
* 2, and then checked that every "conflicting" array has curr_resync
* less than ours. When we find one that is the same or higher
* we wait on resync_wait. To avoid deadlock, we reduce curr_resync
* to 1 if we choose to yield (based arbitrarily on address of mddev structure).
* This will mean we have to start checking from the beginning again.
*
*/
do {
int mddev2_minor = -1;
mddev->curr_resync = MD_RESYNC_DELAYED;
try_again:
if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
goto skip;
spin_lock(&all_mddevs_lock);
list_for_each_entry(mddev2, &all_mddevs, all_mddevs) {
if (test_bit(MD_DELETED, &mddev2->flags))
continue;
if (mddev2 == mddev)
continue;
if (!mddev->parallel_resync
&& mddev2->curr_resync
&& match_mddev_units(mddev, mddev2)) {
DEFINE_WAIT(wq);
if (mddev < mddev2 &&
mddev->curr_resync == MD_RESYNC_DELAYED) {
/* arbitrarily yield */
mddev->curr_resync = MD_RESYNC_YIELDED;
wake_up(&resync_wait);
}
if (mddev > mddev2 &&
mddev->curr_resync == MD_RESYNC_YIELDED)
/* no need to wait here, we can wait the next
* time 'round when curr_resync == 2
*/
continue;
/* We need to wait 'interruptible' so as not to
* contribute to the load average, and not to
* be caught by 'softlockup'
*/
prepare_to_wait(&resync_wait, &wq, TASK_INTERRUPTIBLE);
if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
mddev2->curr_resync >= mddev->curr_resync) {
if (mddev2_minor != mddev2->md_minor) {
mddev2_minor = mddev2->md_minor;
pr_info("md: delaying %s of %s until %s has finished (they share one or more physical units)\n",
desc, mdname(mddev),
mdname(mddev2));
}
spin_unlock(&all_mddevs_lock);
if (signal_pending(current))
flush_signals(current);
schedule();
finish_wait(&resync_wait, &wq);
goto try_again;
}
finish_wait(&resync_wait, &wq);
}
}
spin_unlock(&all_mddevs_lock);
} while (mddev->curr_resync < MD_RESYNC_DELAYED);
j = 0;
if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
/* resync follows the size requested by the personality,
* which defaults to physical size, but can be virtual size
*/
max_sectors = mddev->resync_max_sectors;
atomic64_set(&mddev->resync_mismatches, 0);
/* we don't use the checkpoint if there's a bitmap */
if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
j = mddev->resync_min;
else if (!mddev->bitmap)
j = mddev->recovery_cp;
} else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
max_sectors = mddev->resync_max_sectors;
/*
* If the original node aborts reshaping then we continue the
* reshaping, so set j again to avoid restart reshape from the
* first beginning
*/
if (mddev_is_clustered(mddev) &&
mddev->reshape_position != MaxSector)
j = mddev->reshape_position;
} else {
/* recovery follows the physical size of devices */
max_sectors = mddev->dev_sectors;
j = MaxSector;
rcu_read_lock();
rdev_for_each_rcu(rdev, mddev)
if (rdev->raid_disk >= 0 &&
!test_bit(Journal, &rdev->flags) &&
!test_bit(Faulty, &rdev->flags) &&
!test_bit(In_sync, &rdev->flags) &&
rdev->recovery_offset < j)
j = rdev->recovery_offset;
rcu_read_unlock();
/* If there is a bitmap, we need to make sure all
* writes that started before we added a spare
* complete before we start doing a recovery.
* Otherwise the write might complete and (via
* bitmap_endwrite) set a bit in the bitmap after the
* recovery has checked that bit and skipped that
* region.
*/
if (mddev->bitmap) {
mddev->pers->quiesce(mddev, 1);
mddev->pers->quiesce(mddev, 0);
}
}
pr_info("md: %s of RAID array %s\n", desc, mdname(mddev));
pr_debug("md: minimum _guaranteed_ speed: %d KB/sec/disk.\n", speed_min(mddev));
pr_debug("md: using maximum available idle IO bandwidth (but not more than %d KB/sec) for %s.\n",
speed_max(mddev), desc);
is_mddev_idle(mddev, 1); /* this initializes IO event counters */
io_sectors = 0;
for (m = 0; m < SYNC_MARKS; m++) {
mark[m] = jiffies;
mark_cnt[m] = io_sectors;
}
last_mark = 0;
mddev->resync_mark = mark[last_mark];
mddev->resync_mark_cnt = mark_cnt[last_mark];
/*
* Tune reconstruction:
*/
window = 32 * (PAGE_SIZE / 512);
pr_debug("md: using %dk window, over a total of %lluk.\n",
window/2, (unsigned long long)max_sectors/2);
atomic_set(&mddev->recovery_active, 0);
last_check = 0;
if (j >= MD_RESYNC_ACTIVE) {
pr_debug("md: resuming %s of %s from checkpoint.\n",
desc, mdname(mddev));
mddev->curr_resync = j;
} else
mddev->curr_resync = MD_RESYNC_ACTIVE; /* no longer delayed */
mddev->curr_resync_completed = j;
sysfs_notify_dirent_safe(mddev->sysfs_completed);
md_new_event();
update_time = jiffies;
blk_start_plug(&plug);
while (j < max_sectors) {
sector_t sectors;
skipped = 0;
if (!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
((mddev->curr_resync > mddev->curr_resync_completed &&
(mddev->curr_resync - mddev->curr_resync_completed)
> (max_sectors >> 4)) ||
time_after_eq(jiffies, update_time + UPDATE_FREQUENCY) ||
(j - mddev->curr_resync_completed)*2
>= mddev->resync_max - mddev->curr_resync_completed ||
mddev->curr_resync_completed > mddev->resync_max
)) {
/* time to update curr_resync_completed */
wait_event(mddev->recovery_wait,
atomic_read(&mddev->recovery_active) == 0);
mddev->curr_resync_completed = j;
if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
j > mddev->recovery_cp)
mddev->recovery_cp = j;
update_time = jiffies;
set_bit(MD_SB_CHANGE_CLEAN, &mddev->sb_flags);
sysfs_notify_dirent_safe(mddev->sysfs_completed);
}
while (j >= mddev->resync_max &&
!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
/* As this condition is controlled by user-space,
* we can block indefinitely, so use '_interruptible'
* to avoid triggering warnings.
*/
flush_signals(current); /* just in case */
wait_event_interruptible(mddev->recovery_wait,
mddev->resync_max > j
|| test_bit(MD_RECOVERY_INTR,
&mddev->recovery));
}
if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
break;
sectors = mddev->pers->sync_request(mddev, j, &skipped);
if (sectors == 0) {
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
break;
}
if (!skipped) { /* actual IO requested */
io_sectors += sectors;
atomic_add(sectors, &mddev->recovery_active);
}
if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
break;
j += sectors;
if (j > max_sectors)
/* when skipping, extra large numbers can be returned. */
j = max_sectors;
if (j >= MD_RESYNC_ACTIVE)
mddev->curr_resync = j;
mddev->curr_mark_cnt = io_sectors;
if (last_check == 0)
/* this is the earliest that rebuild will be
* visible in /proc/mdstat
*/
md_new_event();
if (last_check + window > io_sectors || j == max_sectors)
continue;
last_check = io_sectors;
repeat:
if (time_after_eq(jiffies, mark[last_mark] + SYNC_MARK_STEP )) {
/* step marks */
int next = (last_mark+1) % SYNC_MARKS;
mddev->resync_mark = mark[next];
mddev->resync_mark_cnt = mark_cnt[next];
mark[next] = jiffies;
mark_cnt[next] = io_sectors - atomic_read(&mddev->recovery_active);
last_mark = next;
}
if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
break;
/*
* this loop exits only if either when we are slower than
* the 'hard' speed limit, or the system was IO-idle for
* a jiffy.
* the system might be non-idle CPU-wise, but we only care
* about not overloading the IO subsystem. (things like an
* e2fsck being done on the RAID array should execute fast)
*/
cond_resched();
recovery_done = io_sectors - atomic_read(&mddev->recovery_active);
currspeed = ((unsigned long)(recovery_done - mddev->resync_mark_cnt))/2
/((jiffies-mddev->resync_mark)/HZ +1) +1;
if (currspeed > speed_min(mddev)) {
if (currspeed > speed_max(mddev)) {
msleep(500);
goto repeat;
}
if (!is_mddev_idle(mddev, 0)) {
/*
* Give other IO more of a chance.
* The faster the devices, the less we wait.
*/
wait_event(mddev->recovery_wait,
!atomic_read(&mddev->recovery_active));
}
}
}
pr_info("md: %s: %s %s.\n",mdname(mddev), desc,
test_bit(MD_RECOVERY_INTR, &mddev->recovery)
? "interrupted" : "done");
/*
* this also signals 'finished resyncing' to md_stop
*/
blk_finish_plug(&plug);
wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
if (!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
mddev->curr_resync >= MD_RESYNC_ACTIVE) {
mddev->curr_resync_completed = mddev->curr_resync;
sysfs_notify_dirent_safe(mddev->sysfs_completed);
}
mddev->pers->sync_request(mddev, max_sectors, &skipped);
if (!test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
mddev->curr_resync > MD_RESYNC_ACTIVE) {
if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
if (mddev->curr_resync >= mddev->recovery_cp) {
pr_debug("md: checkpointing %s of %s.\n",
desc, mdname(mddev));
if (test_bit(MD_RECOVERY_ERROR,
&mddev->recovery))
mddev->recovery_cp =
mddev->curr_resync_completed;
else
mddev->recovery_cp =
mddev->curr_resync;
}
} else
mddev->recovery_cp = MaxSector;
} else {
if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
mddev->curr_resync = MaxSector;
if (!test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
test_bit(MD_RECOVERY_RECOVER, &mddev->recovery)) {
rcu_read_lock();
rdev_for_each_rcu(rdev, mddev)
if (rdev->raid_disk >= 0 &&
mddev->delta_disks >= 0 &&
!test_bit(Journal, &rdev->flags) &&
!test_bit(Faulty, &rdev->flags) &&
!test_bit(In_sync, &rdev->flags) &&
rdev->recovery_offset < mddev->curr_resync)
rdev->recovery_offset = mddev->curr_resync;
rcu_read_unlock();
}
}
}
skip:
/* set CHANGE_PENDING here since maybe another update is needed,
* so other nodes are informed. It should be harmless for normal
* raid */
set_mask_bits(&mddev->sb_flags, 0,
BIT(MD_SB_CHANGE_PENDING) | BIT(MD_SB_CHANGE_DEVS));
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
mddev->delta_disks > 0 &&
mddev->pers->finish_reshape &&
mddev->pers->size &&
mddev->queue) {
mddev_lock_nointr(mddev);
md_set_array_sectors(mddev, mddev->pers->size(mddev, 0, 0));
mddev_unlock(mddev);
if (!mddev_is_clustered(mddev))
set_capacity_and_notify(mddev->gendisk,
mddev->array_sectors);
}
spin_lock(&mddev->lock);
if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
/* We completed so min/max setting can be forgotten if used. */
if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
mddev->resync_min = 0;
mddev->resync_max = MaxSector;
} else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
mddev->resync_min = mddev->curr_resync_completed;
set_bit(MD_RECOVERY_DONE, &mddev->recovery);
mddev->curr_resync = MD_RESYNC_NONE;
spin_unlock(&mddev->lock);
wake_up(&resync_wait);
wake_up(&mddev->sb_wait);
md_wakeup_thread(mddev->thread);
return;
}
EXPORT_SYMBOL_GPL(md_do_sync);
static int remove_and_add_spares(struct mddev *mddev,
struct md_rdev *this)
{
struct md_rdev *rdev;
int spares = 0;
int removed = 0;
bool remove_some = false;
if (this && test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
/* Mustn't remove devices when resync thread is running */
return 0;
rdev_for_each(rdev, mddev) {
if ((this == NULL || rdev == this) &&
rdev->raid_disk >= 0 &&
!test_bit(Blocked, &rdev->flags) &&
test_bit(Faulty, &rdev->flags) &&
atomic_read(&rdev->nr_pending)==0) {
/* Faulty non-Blocked devices with nr_pending == 0
* never get nr_pending incremented,
* never get Faulty cleared, and never get Blocked set.
* So we can synchronize_rcu now rather than once per device
*/
remove_some = true;
set_bit(RemoveSynchronized, &rdev->flags);
}
}
if (remove_some)
synchronize_rcu();
rdev_for_each(rdev, mddev) {
if ((this == NULL || rdev == this) &&
rdev->raid_disk >= 0 &&
!test_bit(Blocked, &rdev->flags) &&
((test_bit(RemoveSynchronized, &rdev->flags) ||
(!test_bit(In_sync, &rdev->flags) &&
!test_bit(Journal, &rdev->flags))) &&
atomic_read(&rdev->nr_pending)==0)) {
if (mddev->pers->hot_remove_disk(
mddev, rdev) == 0) {
sysfs_unlink_rdev(mddev, rdev);
rdev->saved_raid_disk = rdev->raid_disk;
rdev->raid_disk = -1;
removed++;
}
}
if (remove_some && test_bit(RemoveSynchronized, &rdev->flags))
clear_bit(RemoveSynchronized, &rdev->flags);
}
if (removed && mddev->kobj.sd)
sysfs_notify_dirent_safe(mddev->sysfs_degraded);
if (this && removed)
goto no_add;
rdev_for_each(rdev, mddev) {
if (this && this != rdev)
continue;
if (test_bit(Candidate, &rdev->flags))
continue;
if (rdev->raid_disk >= 0 &&
!test_bit(In_sync, &rdev->flags) &&
!test_bit(Journal, &rdev->flags) &&
!test_bit(Faulty, &rdev->flags))
spares++;
if (rdev->raid_disk >= 0)
continue;
if (test_bit(Faulty, &rdev->flags))
continue;
if (!test_bit(Journal, &rdev->flags)) {
if (!md_is_rdwr(mddev) &&
!(rdev->saved_raid_disk >= 0 &&
!test_bit(Bitmap_sync, &rdev->flags)))
continue;
rdev->recovery_offset = 0;
}
if (mddev->pers->hot_add_disk(mddev, rdev) == 0) {
/* failure here is OK */
sysfs_link_rdev(mddev, rdev);
if (!test_bit(Journal, &rdev->flags))
spares++;
md_new_event();
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
}
}
no_add:
if (removed)
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
return spares;
}
static void md_start_sync(struct work_struct *ws)
{
struct mddev *mddev = container_of(ws, struct mddev, del_work);
rcu_assign_pointer(mddev->sync_thread,
md_register_thread(md_do_sync, mddev, "resync"));
if (!mddev->sync_thread) {
pr_warn("%s: could not start resync thread...\n",
mdname(mddev));
/* leave the spares where they are, it shouldn't hurt */
clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
wake_up(&resync_wait);
if (test_and_clear_bit(MD_RECOVERY_RECOVER,
&mddev->recovery))
if (mddev->sysfs_action)
sysfs_notify_dirent_safe(mddev->sysfs_action);
} else
md_wakeup_thread(mddev->sync_thread);
sysfs_notify_dirent_safe(mddev->sysfs_action);
md_new_event();
}
/*
* This routine is regularly called by all per-raid-array threads to
* deal with generic issues like resync and super-block update.
* Raid personalities that don't have a thread (linear/raid0) do not
* need this as they never do any recovery or update the superblock.
*
* It does not do any resync itself, but rather "forks" off other threads
* to do that as needed.
* When it is determined that resync is needed, we set MD_RECOVERY_RUNNING in
* "->recovery" and create a thread at ->sync_thread.
* When the thread finishes it sets MD_RECOVERY_DONE
* and wakeups up this thread which will reap the thread and finish up.
* This thread also removes any faulty devices (with nr_pending == 0).
*
* The overall approach is:
* 1/ if the superblock needs updating, update it.
* 2/ If a recovery thread is running, don't do anything else.
* 3/ If recovery has finished, clean up, possibly marking spares active.
* 4/ If there are any faulty devices, remove them.
* 5/ If array is degraded, try to add spares devices
* 6/ If array has spares or is not in-sync, start a resync thread.
*/
void md_check_recovery(struct mddev *mddev)
{
if (test_bit(MD_ALLOW_SB_UPDATE, &mddev->flags) && mddev->sb_flags) {
/* Write superblock - thread that called mddev_suspend()
* holds reconfig_mutex for us.
*/
set_bit(MD_UPDATING_SB, &mddev->flags);
smp_mb__after_atomic();
if (test_bit(MD_ALLOW_SB_UPDATE, &mddev->flags))
md_update_sb(mddev, 0);
clear_bit_unlock(MD_UPDATING_SB, &mddev->flags);
wake_up(&mddev->sb_wait);
}
if (is_md_suspended(mddev))
return;
if (mddev->bitmap)
md_bitmap_daemon_work(mddev);
if (signal_pending(current)) {
if (mddev->pers->sync_request && !mddev->external) {
pr_debug("md: %s in immediate safe mode\n",
mdname(mddev));
mddev->safemode = 2;
}
flush_signals(current);
}
if (!md_is_rdwr(mddev) &&
!test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
return;
if ( ! (
(mddev->sb_flags & ~ (1<<MD_SB_CHANGE_PENDING)) ||
test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
(mddev->external == 0 && mddev->safemode == 1) ||
(mddev->safemode == 2
&& !mddev->in_sync && mddev->recovery_cp == MaxSector)
))
return;
if (mddev_trylock(mddev)) {
int spares = 0;
bool try_set_sync = mddev->safemode != 0;
if (!mddev->external && mddev->safemode == 1)
mddev->safemode = 0;
if (!md_is_rdwr(mddev)) {
struct md_rdev *rdev;
if (!mddev->external && mddev->in_sync)
/* 'Blocked' flag not needed as failed devices
* will be recorded if array switched to read/write.
* Leaving it set will prevent the device
* from being removed.
*/
rdev_for_each(rdev, mddev)
clear_bit(Blocked, &rdev->flags);
/* On a read-only array we can:
* - remove failed devices
* - add already-in_sync devices if the array itself
* is in-sync.
* As we only add devices that are already in-sync,
* we can activate the spares immediately.
*/
remove_and_add_spares(mddev, NULL);
/* There is no thread, but we need to call
* ->spare_active and clear saved_raid_disk
*/
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
md_reap_sync_thread(mddev);
clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
clear_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags);
goto unlock;
}
if (mddev_is_clustered(mddev)) {
struct md_rdev *rdev, *tmp;
/* kick the device if another node issued a
* remove disk.
*/
rdev_for_each_safe(rdev, tmp, mddev) {
if (test_and_clear_bit(ClusterRemove, &rdev->flags) &&
rdev->raid_disk < 0)
md_kick_rdev_from_array(rdev);
}
}
if (try_set_sync && !mddev->external && !mddev->in_sync) {
spin_lock(&mddev->lock);
set_in_sync(mddev);
spin_unlock(&mddev->lock);
}
if (mddev->sb_flags)
md_update_sb(mddev, 0);
/*
* Never start a new sync thread if MD_RECOVERY_RUNNING is
* still set.
*/
if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
if (!test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
/* resync/recovery still happening */
clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
goto unlock;
}
if (WARN_ON_ONCE(!mddev->sync_thread))
goto unlock;
md_reap_sync_thread(mddev);
goto unlock;
}
/* Set RUNNING before clearing NEEDED to avoid
* any transients in the value of "sync_action".
*/
mddev->curr_resync_completed = 0;
spin_lock(&mddev->lock);
set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
spin_unlock(&mddev->lock);
/* Clear some bits that don't mean anything, but
* might be left set
*/
clear_bit(MD_RECOVERY_INTR, &mddev->recovery);
clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
if (!test_and_clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
goto not_running;
/* no recovery is running.
* remove any failed drives, then
* add spares if possible.
* Spares are also removed and re-added, to allow
* the personality to fail the re-add.
*/
if (mddev->reshape_position != MaxSector) {
if (mddev->pers->check_reshape == NULL ||
mddev->pers->check_reshape(mddev) != 0)
/* Cannot proceed */
goto not_running;
set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
} else if ((spares = remove_and_add_spares(mddev, NULL))) {
clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
} else if (mddev->recovery_cp < MaxSector) {
set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
} else if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
/* nothing to be done ... */
goto not_running;
if (mddev->pers->sync_request) {
if (spares) {
/* We are adding a device or devices to an array
* which has the bitmap stored on all devices.
* So make sure all bitmap pages get written
*/
md_bitmap_write_all(mddev->bitmap);
}
INIT_WORK(&mddev->del_work, md_start_sync);
queue_work(md_misc_wq, &mddev->del_work);
goto unlock;
}
not_running:
if (!mddev->sync_thread) {
clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
wake_up(&resync_wait);
if (test_and_clear_bit(MD_RECOVERY_RECOVER,
&mddev->recovery))
if (mddev->sysfs_action)
sysfs_notify_dirent_safe(mddev->sysfs_action);
}
unlock:
wake_up(&mddev->sb_wait);
mddev_unlock(mddev);
}
}
EXPORT_SYMBOL(md_check_recovery);
void md_reap_sync_thread(struct mddev *mddev)
{
struct md_rdev *rdev;
sector_t old_dev_sectors = mddev->dev_sectors;
bool is_reshaped = false;
/* resync has finished, collect result */
md_unregister_thread(mddev, &mddev->sync_thread);
atomic_inc(&mddev->sync_seq);
if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) &&
!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
mddev->degraded != mddev->raid_disks) {
/* success...*/
/* activate any spares */
if (mddev->pers->spare_active(mddev)) {
sysfs_notify_dirent_safe(mddev->sysfs_degraded);
set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
}
}
if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
mddev->pers->finish_reshape) {
mddev->pers->finish_reshape(mddev);
if (mddev_is_clustered(mddev))
is_reshaped = true;
}
/* If array is no-longer degraded, then any saved_raid_disk
* information must be scrapped.
*/
if (!mddev->degraded)
rdev_for_each(rdev, mddev)
rdev->saved_raid_disk = -1;
md_update_sb(mddev, 1);
/* MD_SB_CHANGE_PENDING should be cleared by md_update_sb, so we can
* call resync_finish here if MD_CLUSTER_RESYNC_LOCKED is set by
* clustered raid */
if (test_and_clear_bit(MD_CLUSTER_RESYNC_LOCKED, &mddev->flags))
md_cluster_ops->resync_finish(mddev);
clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
clear_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
clear_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
/*
* We call md_cluster_ops->update_size here because sync_size could
* be changed by md_update_sb, and MD_RECOVERY_RESHAPE is cleared,
* so it is time to update size across cluster.
*/
if (mddev_is_clustered(mddev) && is_reshaped
&& !test_bit(MD_CLOSING, &mddev->flags))
md_cluster_ops->update_size(mddev, old_dev_sectors);
/* flag recovery needed just to double check */
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
sysfs_notify_dirent_safe(mddev->sysfs_completed);
sysfs_notify_dirent_safe(mddev->sysfs_action);
md_new_event();
if (mddev->event_work.func)
queue_work(md_misc_wq, &mddev->event_work);
wake_up(&resync_wait);
}
EXPORT_SYMBOL(md_reap_sync_thread);
void md_wait_for_blocked_rdev(struct md_rdev *rdev, struct mddev *mddev)
{
sysfs_notify_dirent_safe(rdev->sysfs_state);
wait_event_timeout(rdev->blocked_wait,
!test_bit(Blocked, &rdev->flags) &&
!test_bit(BlockedBadBlocks, &rdev->flags),
msecs_to_jiffies(5000));
rdev_dec_pending(rdev, mddev);
}
EXPORT_SYMBOL(md_wait_for_blocked_rdev);
void md_finish_reshape(struct mddev *mddev)
{
/* called be personality module when reshape completes. */
struct md_rdev *rdev;
rdev_for_each(rdev, mddev) {
if (rdev->data_offset > rdev->new_data_offset)
rdev->sectors += rdev->data_offset - rdev->new_data_offset;
else
rdev->sectors -= rdev->new_data_offset - rdev->data_offset;
rdev->data_offset = rdev->new_data_offset;
}
}
EXPORT_SYMBOL(md_finish_reshape);
/* Bad block management */
/* Returns 1 on success, 0 on failure */
int rdev_set_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
int is_new)
{
struct mddev *mddev = rdev->mddev;
int rv;
if (is_new)
s += rdev->new_data_offset;
else
s += rdev->data_offset;
rv = badblocks_set(&rdev->badblocks, s, sectors, 0);
if (rv == 0) {
/* Make sure they get written out promptly */
if (test_bit(ExternalBbl, &rdev->flags))
sysfs_notify_dirent_safe(rdev->sysfs_unack_badblocks);
sysfs_notify_dirent_safe(rdev->sysfs_state);
set_mask_bits(&mddev->sb_flags, 0,
BIT(MD_SB_CHANGE_CLEAN) | BIT(MD_SB_CHANGE_PENDING));
md_wakeup_thread(rdev->mddev->thread);
return 1;
} else
return 0;
}
EXPORT_SYMBOL_GPL(rdev_set_badblocks);
int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
int is_new)
{
int rv;
if (is_new)
s += rdev->new_data_offset;
else
s += rdev->data_offset;
rv = badblocks_clear(&rdev->badblocks, s, sectors);
if ((rv == 0) && test_bit(ExternalBbl, &rdev->flags))
sysfs_notify_dirent_safe(rdev->sysfs_badblocks);
return rv;
}
EXPORT_SYMBOL_GPL(rdev_clear_badblocks);
static int md_notify_reboot(struct notifier_block *this,
unsigned long code, void *x)
{
struct mddev *mddev, *n;
int need_delay = 0;
spin_lock(&all_mddevs_lock);
list_for_each_entry_safe(mddev, n, &all_mddevs, all_mddevs) {
if (!mddev_get(mddev))
continue;
spin_unlock(&all_mddevs_lock);
if (mddev_trylock(mddev)) {
if (mddev->pers)
__md_stop_writes(mddev);
if (mddev->persistent)
mddev->safemode = 2;
mddev_unlock(mddev);
}
need_delay = 1;
mddev_put(mddev);
spin_lock(&all_mddevs_lock);
}
spin_unlock(&all_mddevs_lock);
/*
* certain more exotic SCSI devices are known to be
* volatile wrt too early system reboots. While the
* right place to handle this issue is the given
* driver, we do want to have a safe RAID driver ...
*/
if (need_delay)
msleep(1000);
return NOTIFY_DONE;
}
static struct notifier_block md_notifier = {
.notifier_call = md_notify_reboot,
.next = NULL,
.priority = INT_MAX, /* before any real devices */
};
static void md_geninit(void)
{
pr_debug("md: sizeof(mdp_super_t) = %d\n", (int)sizeof(mdp_super_t));
proc_create("mdstat", S_IRUGO, NULL, &mdstat_proc_ops);
}
static int __init md_init(void)
{
int ret = -ENOMEM;
md_wq = alloc_workqueue("md", WQ_MEM_RECLAIM, 0);
if (!md_wq)
goto err_wq;
md_misc_wq = alloc_workqueue("md_misc", 0, 0);
if (!md_misc_wq)
goto err_misc_wq;
md_bitmap_wq = alloc_workqueue("md_bitmap", WQ_MEM_RECLAIM | WQ_UNBOUND,
0);
if (!md_bitmap_wq)
goto err_bitmap_wq;
ret = __register_blkdev(MD_MAJOR, "md", md_probe);
if (ret < 0)
goto err_md;
ret = __register_blkdev(0, "mdp", md_probe);
if (ret < 0)
goto err_mdp;
mdp_major = ret;
register_reboot_notifier(&md_notifier);
raid_table_header = register_sysctl("dev/raid", raid_table);
md_geninit();
return 0;
err_mdp:
unregister_blkdev(MD_MAJOR, "md");
err_md:
destroy_workqueue(md_bitmap_wq);
err_bitmap_wq:
destroy_workqueue(md_misc_wq);
err_misc_wq:
destroy_workqueue(md_wq);
err_wq:
return ret;
}
static void check_sb_changes(struct mddev *mddev, struct md_rdev *rdev)
{
struct mdp_superblock_1 *sb = page_address(rdev->sb_page);
struct md_rdev *rdev2, *tmp;
int role, ret;
/*
* If size is changed in another node then we need to
* do resize as well.
*/
if (mddev->dev_sectors != le64_to_cpu(sb->size)) {
ret = mddev->pers->resize(mddev, le64_to_cpu(sb->size));
if (ret)
pr_info("md-cluster: resize failed\n");
else
md_bitmap_update_sb(mddev->bitmap);
}
/* Check for change of roles in the active devices */
rdev_for_each_safe(rdev2, tmp, mddev) {
if (test_bit(Faulty, &rdev2->flags))
continue;
/* Check if the roles changed */
role = le16_to_cpu(sb->dev_roles[rdev2->desc_nr]);
if (test_bit(Candidate, &rdev2->flags)) {
if (role == MD_DISK_ROLE_FAULTY) {
pr_info("md: Removing Candidate device %pg because add failed\n",
rdev2->bdev);
md_kick_rdev_from_array(rdev2);
continue;
}
else
clear_bit(Candidate, &rdev2->flags);
}
if (role != rdev2->raid_disk) {
/*
* got activated except reshape is happening.
*/
if (rdev2->raid_disk == -1 && role != MD_DISK_ROLE_SPARE &&
!(le32_to_cpu(sb->feature_map) &
MD_FEATURE_RESHAPE_ACTIVE)) {
rdev2->saved_raid_disk = role;
ret = remove_and_add_spares(mddev, rdev2);
pr_info("Activated spare: %pg\n",
rdev2->bdev);
/* wakeup mddev->thread here, so array could
* perform resync with the new activated disk */
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
}
/* device faulty
* We just want to do the minimum to mark the disk
* as faulty. The recovery is performed by the
* one who initiated the error.
*/
if (role == MD_DISK_ROLE_FAULTY ||
role == MD_DISK_ROLE_JOURNAL) {
md_error(mddev, rdev2);
clear_bit(Blocked, &rdev2->flags);
}
}
}
if (mddev->raid_disks != le32_to_cpu(sb->raid_disks)) {
ret = update_raid_disks(mddev, le32_to_cpu(sb->raid_disks));
if (ret)
pr_warn("md: updating array disks failed. %d\n", ret);
}
/*
* Since mddev->delta_disks has already updated in update_raid_disks,
* so it is time to check reshape.
*/
if (test_bit(MD_RESYNCING_REMOTE, &mddev->recovery) &&
(le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
/*
* reshape is happening in the remote node, we need to
* update reshape_position and call start_reshape.
*/
mddev->reshape_position = le64_to_cpu(sb->reshape_position);
if (mddev->pers->update_reshape_pos)
mddev->pers->update_reshape_pos(mddev);
if (mddev->pers->start_reshape)
mddev->pers->start_reshape(mddev);
} else if (test_bit(MD_RESYNCING_REMOTE, &mddev->recovery) &&
mddev->reshape_position != MaxSector &&
!(le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
/* reshape is just done in another node. */
mddev->reshape_position = MaxSector;
if (mddev->pers->update_reshape_pos)
mddev->pers->update_reshape_pos(mddev);
}
/* Finally set the event to be up to date */
mddev->events = le64_to_cpu(sb->events);
}
static int read_rdev(struct mddev *mddev, struct md_rdev *rdev)
{
int err;
struct page *swapout = rdev->sb_page;
struct mdp_superblock_1 *sb;
/* Store the sb page of the rdev in the swapout temporary
* variable in case we err in the future
*/
rdev->sb_page = NULL;
err = alloc_disk_sb(rdev);
if (err == 0) {
ClearPageUptodate(rdev->sb_page);
rdev->sb_loaded = 0;
err = super_types[mddev->major_version].
load_super(rdev, NULL, mddev->minor_version);
}
if (err < 0) {
pr_warn("%s: %d Could not reload rdev(%d) err: %d. Restoring old values\n",
__func__, __LINE__, rdev->desc_nr, err);
if (rdev->sb_page)
put_page(rdev->sb_page);
rdev->sb_page = swapout;
rdev->sb_loaded = 1;
return err;
}
sb = page_address(rdev->sb_page);
/* Read the offset unconditionally, even if MD_FEATURE_RECOVERY_OFFSET
* is not set
*/
if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RECOVERY_OFFSET))
rdev->recovery_offset = le64_to_cpu(sb->recovery_offset);
/* The other node finished recovery, call spare_active to set
* device In_sync and mddev->degraded
*/
if (rdev->recovery_offset == MaxSector &&
!test_bit(In_sync, &rdev->flags) &&
mddev->pers->spare_active(mddev))
sysfs_notify_dirent_safe(mddev->sysfs_degraded);
put_page(swapout);
return 0;
}
void md_reload_sb(struct mddev *mddev, int nr)
{
struct md_rdev *rdev = NULL, *iter;
int err;
/* Find the rdev */
rdev_for_each_rcu(iter, mddev) {
if (iter->desc_nr == nr) {
rdev = iter;
break;
}
}
if (!rdev) {
pr_warn("%s: %d Could not find rdev with nr %d\n", __func__, __LINE__, nr);
return;
}
err = read_rdev(mddev, rdev);
if (err < 0)
return;
check_sb_changes(mddev, rdev);
/* Read all rdev's to update recovery_offset */
rdev_for_each_rcu(rdev, mddev) {
if (!test_bit(Faulty, &rdev->flags))
read_rdev(mddev, rdev);
}
}
EXPORT_SYMBOL(md_reload_sb);
#ifndef MODULE
/*
* Searches all registered partitions for autorun RAID arrays
* at boot time.
*/
static DEFINE_MUTEX(detected_devices_mutex);
static LIST_HEAD(all_detected_devices);
struct detected_devices_node {
struct list_head list;
dev_t dev;
};
void md_autodetect_dev(dev_t dev)
{
struct detected_devices_node *node_detected_dev;
node_detected_dev = kzalloc(sizeof(*node_detected_dev), GFP_KERNEL);
if (node_detected_dev) {
node_detected_dev->dev = dev;
mutex_lock(&detected_devices_mutex);
list_add_tail(&node_detected_dev->list, &all_detected_devices);
mutex_unlock(&detected_devices_mutex);
}
}
void md_autostart_arrays(int part)
{
struct md_rdev *rdev;
struct detected_devices_node *node_detected_dev;
dev_t dev;
int i_scanned, i_passed;
i_scanned = 0;
i_passed = 0;
pr_info("md: Autodetecting RAID arrays.\n");
mutex_lock(&detected_devices_mutex);
while (!list_empty(&all_detected_devices) && i_scanned < INT_MAX) {
i_scanned++;
node_detected_dev = list_entry(all_detected_devices.next,
struct detected_devices_node, list);
list_del(&node_detected_dev->list);
dev = node_detected_dev->dev;
kfree(node_detected_dev);
mutex_unlock(&detected_devices_mutex);
rdev = md_import_device(dev,0, 90);
mutex_lock(&detected_devices_mutex);
if (IS_ERR(rdev))
continue;
if (test_bit(Faulty, &rdev->flags))
continue;
set_bit(AutoDetected, &rdev->flags);
list_add(&rdev->same_set, &pending_raid_disks);
i_passed++;
}
mutex_unlock(&detected_devices_mutex);
pr_debug("md: Scanned %d and added %d devices.\n", i_scanned, i_passed);
autorun_devices(part);
}
#endif /* !MODULE */
static __exit void md_exit(void)
{
struct mddev *mddev, *n;
int delay = 1;
unregister_blkdev(MD_MAJOR,"md");
unregister_blkdev(mdp_major, "mdp");
unregister_reboot_notifier(&md_notifier);
unregister_sysctl_table(raid_table_header);
/* We cannot unload the modules while some process is
* waiting for us in select() or poll() - wake them up
*/
md_unloading = 1;
while (waitqueue_active(&md_event_waiters)) {
/* not safe to leave yet */
wake_up(&md_event_waiters);
msleep(delay);
delay += delay;
}
remove_proc_entry("mdstat", NULL);
spin_lock(&all_mddevs_lock);
list_for_each_entry_safe(mddev, n, &all_mddevs, all_mddevs) {
if (!mddev_get(mddev))
continue;
spin_unlock(&all_mddevs_lock);
export_array(mddev);
mddev->ctime = 0;
mddev->hold_active = 0;
/*
* As the mddev is now fully clear, mddev_put will schedule
* the mddev for destruction by a workqueue, and the
* destroy_workqueue() below will wait for that to complete.
*/
mddev_put(mddev);
spin_lock(&all_mddevs_lock);
}
spin_unlock(&all_mddevs_lock);
destroy_workqueue(md_misc_wq);
destroy_workqueue(md_bitmap_wq);
destroy_workqueue(md_wq);
}
subsys_initcall(md_init);
module_exit(md_exit)
static int get_ro(char *buffer, const struct kernel_param *kp)
{
return sprintf(buffer, "%d\n", start_readonly);
}
static int set_ro(const char *val, const struct kernel_param *kp)
{
return kstrtouint(val, 10, (unsigned int *)&start_readonly);
}
module_param_call(start_ro, set_ro, get_ro, NULL, S_IRUSR|S_IWUSR);
module_param(start_dirty_degraded, int, S_IRUGO|S_IWUSR);
module_param_call(new_array, add_named_array, NULL, NULL, S_IWUSR);
module_param(create_on_open, bool, S_IRUSR|S_IWUSR);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("MD RAID framework");
MODULE_ALIAS("md");
MODULE_ALIAS_BLOCKDEV_MAJOR(MD_MAJOR);
| linux-master | drivers/md/md.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012 Red Hat. All rights reserved.
*
* This file is released under the GPL.
*/
#include "dm.h"
#include "dm-bio-prison-v2.h"
#include "dm-bio-record.h"
#include "dm-cache-metadata.h"
#include "dm-io-tracker.h"
#include <linux/dm-io.h>
#include <linux/dm-kcopyd.h>
#include <linux/jiffies.h>
#include <linux/init.h>
#include <linux/mempool.h>
#include <linux/module.h>
#include <linux/rwsem.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#define DM_MSG_PREFIX "cache"
DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(cache_copy_throttle,
"A percentage of time allocated for copying to and/or from cache");
/*----------------------------------------------------------------*/
/*
* Glossary:
*
* oblock: index of an origin block
* cblock: index of a cache block
* promotion: movement of a block from origin to cache
* demotion: movement of a block from cache to origin
* migration: movement of a block between the origin and cache device,
* either direction
*/
/*----------------------------------------------------------------*/
/*
* Represents a chunk of future work. 'input' allows continuations to pass
* values between themselves, typically error values.
*/
struct continuation {
struct work_struct ws;
blk_status_t input;
};
static inline void init_continuation(struct continuation *k,
void (*fn)(struct work_struct *))
{
INIT_WORK(&k->ws, fn);
k->input = 0;
}
static inline void queue_continuation(struct workqueue_struct *wq,
struct continuation *k)
{
queue_work(wq, &k->ws);
}
/*----------------------------------------------------------------*/
/*
* The batcher collects together pieces of work that need a particular
* operation to occur before they can proceed (typically a commit).
*/
struct batcher {
/*
* The operation that everyone is waiting for.
*/
blk_status_t (*commit_op)(void *context);
void *commit_context;
/*
* This is how bios should be issued once the commit op is complete
* (accounted_request).
*/
void (*issue_op)(struct bio *bio, void *context);
void *issue_context;
/*
* Queued work gets put on here after commit.
*/
struct workqueue_struct *wq;
spinlock_t lock;
struct list_head work_items;
struct bio_list bios;
struct work_struct commit_work;
bool commit_scheduled;
};
static void __commit(struct work_struct *_ws)
{
struct batcher *b = container_of(_ws, struct batcher, commit_work);
blk_status_t r;
struct list_head work_items;
struct work_struct *ws, *tmp;
struct continuation *k;
struct bio *bio;
struct bio_list bios;
INIT_LIST_HEAD(&work_items);
bio_list_init(&bios);
/*
* We have to grab these before the commit_op to avoid a race
* condition.
*/
spin_lock_irq(&b->lock);
list_splice_init(&b->work_items, &work_items);
bio_list_merge(&bios, &b->bios);
bio_list_init(&b->bios);
b->commit_scheduled = false;
spin_unlock_irq(&b->lock);
r = b->commit_op(b->commit_context);
list_for_each_entry_safe(ws, tmp, &work_items, entry) {
k = container_of(ws, struct continuation, ws);
k->input = r;
INIT_LIST_HEAD(&ws->entry); /* to avoid a WARN_ON */
queue_work(b->wq, ws);
}
while ((bio = bio_list_pop(&bios))) {
if (r) {
bio->bi_status = r;
bio_endio(bio);
} else
b->issue_op(bio, b->issue_context);
}
}
static void batcher_init(struct batcher *b,
blk_status_t (*commit_op)(void *),
void *commit_context,
void (*issue_op)(struct bio *bio, void *),
void *issue_context,
struct workqueue_struct *wq)
{
b->commit_op = commit_op;
b->commit_context = commit_context;
b->issue_op = issue_op;
b->issue_context = issue_context;
b->wq = wq;
spin_lock_init(&b->lock);
INIT_LIST_HEAD(&b->work_items);
bio_list_init(&b->bios);
INIT_WORK(&b->commit_work, __commit);
b->commit_scheduled = false;
}
static void async_commit(struct batcher *b)
{
queue_work(b->wq, &b->commit_work);
}
static void continue_after_commit(struct batcher *b, struct continuation *k)
{
bool commit_scheduled;
spin_lock_irq(&b->lock);
commit_scheduled = b->commit_scheduled;
list_add_tail(&k->ws.entry, &b->work_items);
spin_unlock_irq(&b->lock);
if (commit_scheduled)
async_commit(b);
}
/*
* Bios are errored if commit failed.
*/
static void issue_after_commit(struct batcher *b, struct bio *bio)
{
bool commit_scheduled;
spin_lock_irq(&b->lock);
commit_scheduled = b->commit_scheduled;
bio_list_add(&b->bios, bio);
spin_unlock_irq(&b->lock);
if (commit_scheduled)
async_commit(b);
}
/*
* Call this if some urgent work is waiting for the commit to complete.
*/
static void schedule_commit(struct batcher *b)
{
bool immediate;
spin_lock_irq(&b->lock);
immediate = !list_empty(&b->work_items) || !bio_list_empty(&b->bios);
b->commit_scheduled = true;
spin_unlock_irq(&b->lock);
if (immediate)
async_commit(b);
}
/*
* There are a couple of places where we let a bio run, but want to do some
* work before calling its endio function. We do this by temporarily
* changing the endio fn.
*/
struct dm_hook_info {
bio_end_io_t *bi_end_io;
};
static void dm_hook_bio(struct dm_hook_info *h, struct bio *bio,
bio_end_io_t *bi_end_io, void *bi_private)
{
h->bi_end_io = bio->bi_end_io;
bio->bi_end_io = bi_end_io;
bio->bi_private = bi_private;
}
static void dm_unhook_bio(struct dm_hook_info *h, struct bio *bio)
{
bio->bi_end_io = h->bi_end_io;
}
/*----------------------------------------------------------------*/
#define MIGRATION_POOL_SIZE 128
#define COMMIT_PERIOD HZ
#define MIGRATION_COUNT_WINDOW 10
/*
* The block size of the device holding cache data must be
* between 32KB and 1GB.
*/
#define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (32 * 1024 >> SECTOR_SHIFT)
#define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT)
enum cache_metadata_mode {
CM_WRITE, /* metadata may be changed */
CM_READ_ONLY, /* metadata may not be changed */
CM_FAIL
};
enum cache_io_mode {
/*
* Data is written to cached blocks only. These blocks are marked
* dirty. If you lose the cache device you will lose data.
* Potential performance increase for both reads and writes.
*/
CM_IO_WRITEBACK,
/*
* Data is written to both cache and origin. Blocks are never
* dirty. Potential performance benfit for reads only.
*/
CM_IO_WRITETHROUGH,
/*
* A degraded mode useful for various cache coherency situations
* (eg, rolling back snapshots). Reads and writes always go to the
* origin. If a write goes to a cached oblock, then the cache
* block is invalidated.
*/
CM_IO_PASSTHROUGH
};
struct cache_features {
enum cache_metadata_mode mode;
enum cache_io_mode io_mode;
unsigned int metadata_version;
bool discard_passdown:1;
};
struct cache_stats {
atomic_t read_hit;
atomic_t read_miss;
atomic_t write_hit;
atomic_t write_miss;
atomic_t demotion;
atomic_t promotion;
atomic_t writeback;
atomic_t copies_avoided;
atomic_t cache_cell_clash;
atomic_t commit_count;
atomic_t discard_count;
};
struct cache {
struct dm_target *ti;
spinlock_t lock;
/*
* Fields for converting from sectors to blocks.
*/
int sectors_per_block_shift;
sector_t sectors_per_block;
struct dm_cache_metadata *cmd;
/*
* Metadata is written to this device.
*/
struct dm_dev *metadata_dev;
/*
* The slower of the two data devices. Typically a spindle.
*/
struct dm_dev *origin_dev;
/*
* The faster of the two data devices. Typically an SSD.
*/
struct dm_dev *cache_dev;
/*
* Size of the origin device in _complete_ blocks and native sectors.
*/
dm_oblock_t origin_blocks;
sector_t origin_sectors;
/*
* Size of the cache device in blocks.
*/
dm_cblock_t cache_size;
/*
* Invalidation fields.
*/
spinlock_t invalidation_lock;
struct list_head invalidation_requests;
sector_t migration_threshold;
wait_queue_head_t migration_wait;
atomic_t nr_allocated_migrations;
/*
* The number of in flight migrations that are performing
* background io. eg, promotion, writeback.
*/
atomic_t nr_io_migrations;
struct bio_list deferred_bios;
struct rw_semaphore quiesce_lock;
/*
* origin_blocks entries, discarded if set.
*/
dm_dblock_t discard_nr_blocks;
unsigned long *discard_bitset;
uint32_t discard_block_size; /* a power of 2 times sectors per block */
/*
* Rather than reconstructing the table line for the status we just
* save it and regurgitate.
*/
unsigned int nr_ctr_args;
const char **ctr_args;
struct dm_kcopyd_client *copier;
struct work_struct deferred_bio_worker;
struct work_struct migration_worker;
struct workqueue_struct *wq;
struct delayed_work waker;
struct dm_bio_prison_v2 *prison;
/*
* cache_size entries, dirty if set
*/
unsigned long *dirty_bitset;
atomic_t nr_dirty;
unsigned int policy_nr_args;
struct dm_cache_policy *policy;
/*
* Cache features such as write-through.
*/
struct cache_features features;
struct cache_stats stats;
bool need_tick_bio:1;
bool sized:1;
bool invalidate:1;
bool commit_requested:1;
bool loaded_mappings:1;
bool loaded_discards:1;
struct rw_semaphore background_work_lock;
struct batcher committer;
struct work_struct commit_ws;
struct dm_io_tracker tracker;
mempool_t migration_pool;
struct bio_set bs;
};
struct per_bio_data {
bool tick:1;
unsigned int req_nr:2;
struct dm_bio_prison_cell_v2 *cell;
struct dm_hook_info hook_info;
sector_t len;
};
struct dm_cache_migration {
struct continuation k;
struct cache *cache;
struct policy_work *op;
struct bio *overwrite_bio;
struct dm_bio_prison_cell_v2 *cell;
dm_cblock_t invalidate_cblock;
dm_oblock_t invalidate_oblock;
};
/*----------------------------------------------------------------*/
static bool writethrough_mode(struct cache *cache)
{
return cache->features.io_mode == CM_IO_WRITETHROUGH;
}
static bool writeback_mode(struct cache *cache)
{
return cache->features.io_mode == CM_IO_WRITEBACK;
}
static inline bool passthrough_mode(struct cache *cache)
{
return unlikely(cache->features.io_mode == CM_IO_PASSTHROUGH);
}
/*----------------------------------------------------------------*/
static void wake_deferred_bio_worker(struct cache *cache)
{
queue_work(cache->wq, &cache->deferred_bio_worker);
}
static void wake_migration_worker(struct cache *cache)
{
if (passthrough_mode(cache))
return;
queue_work(cache->wq, &cache->migration_worker);
}
/*----------------------------------------------------------------*/
static struct dm_bio_prison_cell_v2 *alloc_prison_cell(struct cache *cache)
{
return dm_bio_prison_alloc_cell_v2(cache->prison, GFP_NOIO);
}
static void free_prison_cell(struct cache *cache, struct dm_bio_prison_cell_v2 *cell)
{
dm_bio_prison_free_cell_v2(cache->prison, cell);
}
static struct dm_cache_migration *alloc_migration(struct cache *cache)
{
struct dm_cache_migration *mg;
mg = mempool_alloc(&cache->migration_pool, GFP_NOIO);
memset(mg, 0, sizeof(*mg));
mg->cache = cache;
atomic_inc(&cache->nr_allocated_migrations);
return mg;
}
static void free_migration(struct dm_cache_migration *mg)
{
struct cache *cache = mg->cache;
if (atomic_dec_and_test(&cache->nr_allocated_migrations))
wake_up(&cache->migration_wait);
mempool_free(mg, &cache->migration_pool);
}
/*----------------------------------------------------------------*/
static inline dm_oblock_t oblock_succ(dm_oblock_t b)
{
return to_oblock(from_oblock(b) + 1ull);
}
static void build_key(dm_oblock_t begin, dm_oblock_t end, struct dm_cell_key_v2 *key)
{
key->virtual = 0;
key->dev = 0;
key->block_begin = from_oblock(begin);
key->block_end = from_oblock(end);
}
/*
* We have two lock levels. Level 0, which is used to prevent WRITEs, and
* level 1 which prevents *both* READs and WRITEs.
*/
#define WRITE_LOCK_LEVEL 0
#define READ_WRITE_LOCK_LEVEL 1
static unsigned int lock_level(struct bio *bio)
{
return bio_data_dir(bio) == WRITE ?
WRITE_LOCK_LEVEL :
READ_WRITE_LOCK_LEVEL;
}
/*
*--------------------------------------------------------------
* Per bio data
*--------------------------------------------------------------
*/
static struct per_bio_data *get_per_bio_data(struct bio *bio)
{
struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct per_bio_data));
BUG_ON(!pb);
return pb;
}
static struct per_bio_data *init_per_bio_data(struct bio *bio)
{
struct per_bio_data *pb = get_per_bio_data(bio);
pb->tick = false;
pb->req_nr = dm_bio_get_target_bio_nr(bio);
pb->cell = NULL;
pb->len = 0;
return pb;
}
/*----------------------------------------------------------------*/
static void defer_bio(struct cache *cache, struct bio *bio)
{
spin_lock_irq(&cache->lock);
bio_list_add(&cache->deferred_bios, bio);
spin_unlock_irq(&cache->lock);
wake_deferred_bio_worker(cache);
}
static void defer_bios(struct cache *cache, struct bio_list *bios)
{
spin_lock_irq(&cache->lock);
bio_list_merge(&cache->deferred_bios, bios);
bio_list_init(bios);
spin_unlock_irq(&cache->lock);
wake_deferred_bio_worker(cache);
}
/*----------------------------------------------------------------*/
static bool bio_detain_shared(struct cache *cache, dm_oblock_t oblock, struct bio *bio)
{
bool r;
struct per_bio_data *pb;
struct dm_cell_key_v2 key;
dm_oblock_t end = to_oblock(from_oblock(oblock) + 1ULL);
struct dm_bio_prison_cell_v2 *cell_prealloc, *cell;
cell_prealloc = alloc_prison_cell(cache); /* FIXME: allow wait if calling from worker */
build_key(oblock, end, &key);
r = dm_cell_get_v2(cache->prison, &key, lock_level(bio), bio, cell_prealloc, &cell);
if (!r) {
/*
* Failed to get the lock.
*/
free_prison_cell(cache, cell_prealloc);
return r;
}
if (cell != cell_prealloc)
free_prison_cell(cache, cell_prealloc);
pb = get_per_bio_data(bio);
pb->cell = cell;
return r;
}
/*----------------------------------------------------------------*/
static bool is_dirty(struct cache *cache, dm_cblock_t b)
{
return test_bit(from_cblock(b), cache->dirty_bitset);
}
static void set_dirty(struct cache *cache, dm_cblock_t cblock)
{
if (!test_and_set_bit(from_cblock(cblock), cache->dirty_bitset)) {
atomic_inc(&cache->nr_dirty);
policy_set_dirty(cache->policy, cblock);
}
}
/*
* These two are called when setting after migrations to force the policy
* and dirty bitset to be in sync.
*/
static void force_set_dirty(struct cache *cache, dm_cblock_t cblock)
{
if (!test_and_set_bit(from_cblock(cblock), cache->dirty_bitset))
atomic_inc(&cache->nr_dirty);
policy_set_dirty(cache->policy, cblock);
}
static void force_clear_dirty(struct cache *cache, dm_cblock_t cblock)
{
if (test_and_clear_bit(from_cblock(cblock), cache->dirty_bitset)) {
if (atomic_dec_return(&cache->nr_dirty) == 0)
dm_table_event(cache->ti->table);
}
policy_clear_dirty(cache->policy, cblock);
}
/*----------------------------------------------------------------*/
static bool block_size_is_power_of_two(struct cache *cache)
{
return cache->sectors_per_block_shift >= 0;
}
static dm_block_t block_div(dm_block_t b, uint32_t n)
{
do_div(b, n);
return b;
}
static dm_block_t oblocks_per_dblock(struct cache *cache)
{
dm_block_t oblocks = cache->discard_block_size;
if (block_size_is_power_of_two(cache))
oblocks >>= cache->sectors_per_block_shift;
else
oblocks = block_div(oblocks, cache->sectors_per_block);
return oblocks;
}
static dm_dblock_t oblock_to_dblock(struct cache *cache, dm_oblock_t oblock)
{
return to_dblock(block_div(from_oblock(oblock),
oblocks_per_dblock(cache)));
}
static void set_discard(struct cache *cache, dm_dblock_t b)
{
BUG_ON(from_dblock(b) >= from_dblock(cache->discard_nr_blocks));
atomic_inc(&cache->stats.discard_count);
spin_lock_irq(&cache->lock);
set_bit(from_dblock(b), cache->discard_bitset);
spin_unlock_irq(&cache->lock);
}
static void clear_discard(struct cache *cache, dm_dblock_t b)
{
spin_lock_irq(&cache->lock);
clear_bit(from_dblock(b), cache->discard_bitset);
spin_unlock_irq(&cache->lock);
}
static bool is_discarded(struct cache *cache, dm_dblock_t b)
{
int r;
spin_lock_irq(&cache->lock);
r = test_bit(from_dblock(b), cache->discard_bitset);
spin_unlock_irq(&cache->lock);
return r;
}
static bool is_discarded_oblock(struct cache *cache, dm_oblock_t b)
{
int r;
spin_lock_irq(&cache->lock);
r = test_bit(from_dblock(oblock_to_dblock(cache, b)),
cache->discard_bitset);
spin_unlock_irq(&cache->lock);
return r;
}
/*
* -------------------------------------------------------------
* Remapping
*--------------------------------------------------------------
*/
static void remap_to_origin(struct cache *cache, struct bio *bio)
{
bio_set_dev(bio, cache->origin_dev->bdev);
}
static void remap_to_cache(struct cache *cache, struct bio *bio,
dm_cblock_t cblock)
{
sector_t bi_sector = bio->bi_iter.bi_sector;
sector_t block = from_cblock(cblock);
bio_set_dev(bio, cache->cache_dev->bdev);
if (!block_size_is_power_of_two(cache))
bio->bi_iter.bi_sector =
(block * cache->sectors_per_block) +
sector_div(bi_sector, cache->sectors_per_block);
else
bio->bi_iter.bi_sector =
(block << cache->sectors_per_block_shift) |
(bi_sector & (cache->sectors_per_block - 1));
}
static void check_if_tick_bio_needed(struct cache *cache, struct bio *bio)
{
struct per_bio_data *pb;
spin_lock_irq(&cache->lock);
if (cache->need_tick_bio && !op_is_flush(bio->bi_opf) &&
bio_op(bio) != REQ_OP_DISCARD) {
pb = get_per_bio_data(bio);
pb->tick = true;
cache->need_tick_bio = false;
}
spin_unlock_irq(&cache->lock);
}
static void remap_to_origin_clear_discard(struct cache *cache, struct bio *bio,
dm_oblock_t oblock)
{
// FIXME: check_if_tick_bio_needed() is called way too much through this interface
check_if_tick_bio_needed(cache, bio);
remap_to_origin(cache, bio);
if (bio_data_dir(bio) == WRITE)
clear_discard(cache, oblock_to_dblock(cache, oblock));
}
static void remap_to_cache_dirty(struct cache *cache, struct bio *bio,
dm_oblock_t oblock, dm_cblock_t cblock)
{
check_if_tick_bio_needed(cache, bio);
remap_to_cache(cache, bio, cblock);
if (bio_data_dir(bio) == WRITE) {
set_dirty(cache, cblock);
clear_discard(cache, oblock_to_dblock(cache, oblock));
}
}
static dm_oblock_t get_bio_block(struct cache *cache, struct bio *bio)
{
sector_t block_nr = bio->bi_iter.bi_sector;
if (!block_size_is_power_of_two(cache))
(void) sector_div(block_nr, cache->sectors_per_block);
else
block_nr >>= cache->sectors_per_block_shift;
return to_oblock(block_nr);
}
static bool accountable_bio(struct cache *cache, struct bio *bio)
{
return bio_op(bio) != REQ_OP_DISCARD;
}
static void accounted_begin(struct cache *cache, struct bio *bio)
{
struct per_bio_data *pb;
if (accountable_bio(cache, bio)) {
pb = get_per_bio_data(bio);
pb->len = bio_sectors(bio);
dm_iot_io_begin(&cache->tracker, pb->len);
}
}
static void accounted_complete(struct cache *cache, struct bio *bio)
{
struct per_bio_data *pb = get_per_bio_data(bio);
dm_iot_io_end(&cache->tracker, pb->len);
}
static void accounted_request(struct cache *cache, struct bio *bio)
{
accounted_begin(cache, bio);
dm_submit_bio_remap(bio, NULL);
}
static void issue_op(struct bio *bio, void *context)
{
struct cache *cache = context;
accounted_request(cache, bio);
}
/*
* When running in writethrough mode we need to send writes to clean blocks
* to both the cache and origin devices. Clone the bio and send them in parallel.
*/
static void remap_to_origin_and_cache(struct cache *cache, struct bio *bio,
dm_oblock_t oblock, dm_cblock_t cblock)
{
struct bio *origin_bio = bio_alloc_clone(cache->origin_dev->bdev, bio,
GFP_NOIO, &cache->bs);
BUG_ON(!origin_bio);
bio_chain(origin_bio, bio);
if (bio_data_dir(origin_bio) == WRITE)
clear_discard(cache, oblock_to_dblock(cache, oblock));
submit_bio(origin_bio);
remap_to_cache(cache, bio, cblock);
}
/*
*--------------------------------------------------------------
* Failure modes
*--------------------------------------------------------------
*/
static enum cache_metadata_mode get_cache_mode(struct cache *cache)
{
return cache->features.mode;
}
static const char *cache_device_name(struct cache *cache)
{
return dm_table_device_name(cache->ti->table);
}
static void notify_mode_switch(struct cache *cache, enum cache_metadata_mode mode)
{
static const char *descs[] = {
"write",
"read-only",
"fail"
};
dm_table_event(cache->ti->table);
DMINFO("%s: switching cache to %s mode",
cache_device_name(cache), descs[(int)mode]);
}
static void set_cache_mode(struct cache *cache, enum cache_metadata_mode new_mode)
{
bool needs_check;
enum cache_metadata_mode old_mode = get_cache_mode(cache);
if (dm_cache_metadata_needs_check(cache->cmd, &needs_check)) {
DMERR("%s: unable to read needs_check flag, setting failure mode.",
cache_device_name(cache));
new_mode = CM_FAIL;
}
if (new_mode == CM_WRITE && needs_check) {
DMERR("%s: unable to switch cache to write mode until repaired.",
cache_device_name(cache));
if (old_mode != new_mode)
new_mode = old_mode;
else
new_mode = CM_READ_ONLY;
}
/* Never move out of fail mode */
if (old_mode == CM_FAIL)
new_mode = CM_FAIL;
switch (new_mode) {
case CM_FAIL:
case CM_READ_ONLY:
dm_cache_metadata_set_read_only(cache->cmd);
break;
case CM_WRITE:
dm_cache_metadata_set_read_write(cache->cmd);
break;
}
cache->features.mode = new_mode;
if (new_mode != old_mode)
notify_mode_switch(cache, new_mode);
}
static void abort_transaction(struct cache *cache)
{
const char *dev_name = cache_device_name(cache);
if (get_cache_mode(cache) >= CM_READ_ONLY)
return;
DMERR_LIMIT("%s: aborting current metadata transaction", dev_name);
if (dm_cache_metadata_abort(cache->cmd)) {
DMERR("%s: failed to abort metadata transaction", dev_name);
set_cache_mode(cache, CM_FAIL);
}
if (dm_cache_metadata_set_needs_check(cache->cmd)) {
DMERR("%s: failed to set 'needs_check' flag in metadata", dev_name);
set_cache_mode(cache, CM_FAIL);
}
}
static void metadata_operation_failed(struct cache *cache, const char *op, int r)
{
DMERR_LIMIT("%s: metadata operation '%s' failed: error = %d",
cache_device_name(cache), op, r);
abort_transaction(cache);
set_cache_mode(cache, CM_READ_ONLY);
}
/*----------------------------------------------------------------*/
static void load_stats(struct cache *cache)
{
struct dm_cache_statistics stats;
dm_cache_metadata_get_stats(cache->cmd, &stats);
atomic_set(&cache->stats.read_hit, stats.read_hits);
atomic_set(&cache->stats.read_miss, stats.read_misses);
atomic_set(&cache->stats.write_hit, stats.write_hits);
atomic_set(&cache->stats.write_miss, stats.write_misses);
}
static void save_stats(struct cache *cache)
{
struct dm_cache_statistics stats;
if (get_cache_mode(cache) >= CM_READ_ONLY)
return;
stats.read_hits = atomic_read(&cache->stats.read_hit);
stats.read_misses = atomic_read(&cache->stats.read_miss);
stats.write_hits = atomic_read(&cache->stats.write_hit);
stats.write_misses = atomic_read(&cache->stats.write_miss);
dm_cache_metadata_set_stats(cache->cmd, &stats);
}
static void update_stats(struct cache_stats *stats, enum policy_operation op)
{
switch (op) {
case POLICY_PROMOTE:
atomic_inc(&stats->promotion);
break;
case POLICY_DEMOTE:
atomic_inc(&stats->demotion);
break;
case POLICY_WRITEBACK:
atomic_inc(&stats->writeback);
break;
}
}
/*
*---------------------------------------------------------------------
* Migration processing
*
* Migration covers moving data from the origin device to the cache, or
* vice versa.
*---------------------------------------------------------------------
*/
static void inc_io_migrations(struct cache *cache)
{
atomic_inc(&cache->nr_io_migrations);
}
static void dec_io_migrations(struct cache *cache)
{
atomic_dec(&cache->nr_io_migrations);
}
static bool discard_or_flush(struct bio *bio)
{
return bio_op(bio) == REQ_OP_DISCARD || op_is_flush(bio->bi_opf);
}
static void calc_discard_block_range(struct cache *cache, struct bio *bio,
dm_dblock_t *b, dm_dblock_t *e)
{
sector_t sb = bio->bi_iter.bi_sector;
sector_t se = bio_end_sector(bio);
*b = to_dblock(dm_sector_div_up(sb, cache->discard_block_size));
if (se - sb < cache->discard_block_size)
*e = *b;
else
*e = to_dblock(block_div(se, cache->discard_block_size));
}
/*----------------------------------------------------------------*/
static void prevent_background_work(struct cache *cache)
{
lockdep_off();
down_write(&cache->background_work_lock);
lockdep_on();
}
static void allow_background_work(struct cache *cache)
{
lockdep_off();
up_write(&cache->background_work_lock);
lockdep_on();
}
static bool background_work_begin(struct cache *cache)
{
bool r;
lockdep_off();
r = down_read_trylock(&cache->background_work_lock);
lockdep_on();
return r;
}
static void background_work_end(struct cache *cache)
{
lockdep_off();
up_read(&cache->background_work_lock);
lockdep_on();
}
/*----------------------------------------------------------------*/
static bool bio_writes_complete_block(struct cache *cache, struct bio *bio)
{
return (bio_data_dir(bio) == WRITE) &&
(bio->bi_iter.bi_size == (cache->sectors_per_block << SECTOR_SHIFT));
}
static bool optimisable_bio(struct cache *cache, struct bio *bio, dm_oblock_t block)
{
return writeback_mode(cache) &&
(is_discarded_oblock(cache, block) || bio_writes_complete_block(cache, bio));
}
static void quiesce(struct dm_cache_migration *mg,
void (*continuation)(struct work_struct *))
{
init_continuation(&mg->k, continuation);
dm_cell_quiesce_v2(mg->cache->prison, mg->cell, &mg->k.ws);
}
static struct dm_cache_migration *ws_to_mg(struct work_struct *ws)
{
struct continuation *k = container_of(ws, struct continuation, ws);
return container_of(k, struct dm_cache_migration, k);
}
static void copy_complete(int read_err, unsigned long write_err, void *context)
{
struct dm_cache_migration *mg = container_of(context, struct dm_cache_migration, k);
if (read_err || write_err)
mg->k.input = BLK_STS_IOERR;
queue_continuation(mg->cache->wq, &mg->k);
}
static void copy(struct dm_cache_migration *mg, bool promote)
{
struct dm_io_region o_region, c_region;
struct cache *cache = mg->cache;
o_region.bdev = cache->origin_dev->bdev;
o_region.sector = from_oblock(mg->op->oblock) * cache->sectors_per_block;
o_region.count = cache->sectors_per_block;
c_region.bdev = cache->cache_dev->bdev;
c_region.sector = from_cblock(mg->op->cblock) * cache->sectors_per_block;
c_region.count = cache->sectors_per_block;
if (promote)
dm_kcopyd_copy(cache->copier, &o_region, 1, &c_region, 0, copy_complete, &mg->k);
else
dm_kcopyd_copy(cache->copier, &c_region, 1, &o_region, 0, copy_complete, &mg->k);
}
static void bio_drop_shared_lock(struct cache *cache, struct bio *bio)
{
struct per_bio_data *pb = get_per_bio_data(bio);
if (pb->cell && dm_cell_put_v2(cache->prison, pb->cell))
free_prison_cell(cache, pb->cell);
pb->cell = NULL;
}
static void overwrite_endio(struct bio *bio)
{
struct dm_cache_migration *mg = bio->bi_private;
struct cache *cache = mg->cache;
struct per_bio_data *pb = get_per_bio_data(bio);
dm_unhook_bio(&pb->hook_info, bio);
if (bio->bi_status)
mg->k.input = bio->bi_status;
queue_continuation(cache->wq, &mg->k);
}
static void overwrite(struct dm_cache_migration *mg,
void (*continuation)(struct work_struct *))
{
struct bio *bio = mg->overwrite_bio;
struct per_bio_data *pb = get_per_bio_data(bio);
dm_hook_bio(&pb->hook_info, bio, overwrite_endio, mg);
/*
* The overwrite bio is part of the copy operation, as such it does
* not set/clear discard or dirty flags.
*/
if (mg->op->op == POLICY_PROMOTE)
remap_to_cache(mg->cache, bio, mg->op->cblock);
else
remap_to_origin(mg->cache, bio);
init_continuation(&mg->k, continuation);
accounted_request(mg->cache, bio);
}
/*
* Migration steps:
*
* 1) exclusive lock preventing WRITEs
* 2) quiesce
* 3) copy or issue overwrite bio
* 4) upgrade to exclusive lock preventing READs and WRITEs
* 5) quiesce
* 6) update metadata and commit
* 7) unlock
*/
static void mg_complete(struct dm_cache_migration *mg, bool success)
{
struct bio_list bios;
struct cache *cache = mg->cache;
struct policy_work *op = mg->op;
dm_cblock_t cblock = op->cblock;
if (success)
update_stats(&cache->stats, op->op);
switch (op->op) {
case POLICY_PROMOTE:
clear_discard(cache, oblock_to_dblock(cache, op->oblock));
policy_complete_background_work(cache->policy, op, success);
if (mg->overwrite_bio) {
if (success)
force_set_dirty(cache, cblock);
else if (mg->k.input)
mg->overwrite_bio->bi_status = mg->k.input;
else
mg->overwrite_bio->bi_status = BLK_STS_IOERR;
bio_endio(mg->overwrite_bio);
} else {
if (success)
force_clear_dirty(cache, cblock);
dec_io_migrations(cache);
}
break;
case POLICY_DEMOTE:
/*
* We clear dirty here to update the nr_dirty counter.
*/
if (success)
force_clear_dirty(cache, cblock);
policy_complete_background_work(cache->policy, op, success);
dec_io_migrations(cache);
break;
case POLICY_WRITEBACK:
if (success)
force_clear_dirty(cache, cblock);
policy_complete_background_work(cache->policy, op, success);
dec_io_migrations(cache);
break;
}
bio_list_init(&bios);
if (mg->cell) {
if (dm_cell_unlock_v2(cache->prison, mg->cell, &bios))
free_prison_cell(cache, mg->cell);
}
free_migration(mg);
defer_bios(cache, &bios);
wake_migration_worker(cache);
background_work_end(cache);
}
static void mg_success(struct work_struct *ws)
{
struct dm_cache_migration *mg = ws_to_mg(ws);
mg_complete(mg, mg->k.input == 0);
}
static void mg_update_metadata(struct work_struct *ws)
{
int r;
struct dm_cache_migration *mg = ws_to_mg(ws);
struct cache *cache = mg->cache;
struct policy_work *op = mg->op;
switch (op->op) {
case POLICY_PROMOTE:
r = dm_cache_insert_mapping(cache->cmd, op->cblock, op->oblock);
if (r) {
DMERR_LIMIT("%s: migration failed; couldn't insert mapping",
cache_device_name(cache));
metadata_operation_failed(cache, "dm_cache_insert_mapping", r);
mg_complete(mg, false);
return;
}
mg_complete(mg, true);
break;
case POLICY_DEMOTE:
r = dm_cache_remove_mapping(cache->cmd, op->cblock);
if (r) {
DMERR_LIMIT("%s: migration failed; couldn't update on disk metadata",
cache_device_name(cache));
metadata_operation_failed(cache, "dm_cache_remove_mapping", r);
mg_complete(mg, false);
return;
}
/*
* It would be nice if we only had to commit when a REQ_FLUSH
* comes through. But there's one scenario that we have to
* look out for:
*
* - vblock x in a cache block
* - domotion occurs
* - cache block gets reallocated and over written
* - crash
*
* When we recover, because there was no commit the cache will
* rollback to having the data for vblock x in the cache block.
* But the cache block has since been overwritten, so it'll end
* up pointing to data that was never in 'x' during the history
* of the device.
*
* To avoid this issue we require a commit as part of the
* demotion operation.
*/
init_continuation(&mg->k, mg_success);
continue_after_commit(&cache->committer, &mg->k);
schedule_commit(&cache->committer);
break;
case POLICY_WRITEBACK:
mg_complete(mg, true);
break;
}
}
static void mg_update_metadata_after_copy(struct work_struct *ws)
{
struct dm_cache_migration *mg = ws_to_mg(ws);
/*
* Did the copy succeed?
*/
if (mg->k.input)
mg_complete(mg, false);
else
mg_update_metadata(ws);
}
static void mg_upgrade_lock(struct work_struct *ws)
{
int r;
struct dm_cache_migration *mg = ws_to_mg(ws);
/*
* Did the copy succeed?
*/
if (mg->k.input)
mg_complete(mg, false);
else {
/*
* Now we want the lock to prevent both reads and writes.
*/
r = dm_cell_lock_promote_v2(mg->cache->prison, mg->cell,
READ_WRITE_LOCK_LEVEL);
if (r < 0)
mg_complete(mg, false);
else if (r)
quiesce(mg, mg_update_metadata);
else
mg_update_metadata(ws);
}
}
static void mg_full_copy(struct work_struct *ws)
{
struct dm_cache_migration *mg = ws_to_mg(ws);
struct cache *cache = mg->cache;
struct policy_work *op = mg->op;
bool is_policy_promote = (op->op == POLICY_PROMOTE);
if ((!is_policy_promote && !is_dirty(cache, op->cblock)) ||
is_discarded_oblock(cache, op->oblock)) {
mg_upgrade_lock(ws);
return;
}
init_continuation(&mg->k, mg_upgrade_lock);
copy(mg, is_policy_promote);
}
static void mg_copy(struct work_struct *ws)
{
struct dm_cache_migration *mg = ws_to_mg(ws);
if (mg->overwrite_bio) {
/*
* No exclusive lock was held when we last checked if the bio
* was optimisable. So we have to check again in case things
* have changed (eg, the block may no longer be discarded).
*/
if (!optimisable_bio(mg->cache, mg->overwrite_bio, mg->op->oblock)) {
/*
* Fallback to a real full copy after doing some tidying up.
*/
bool rb = bio_detain_shared(mg->cache, mg->op->oblock, mg->overwrite_bio);
BUG_ON(rb); /* An exclussive lock must _not_ be held for this block */
mg->overwrite_bio = NULL;
inc_io_migrations(mg->cache);
mg_full_copy(ws);
return;
}
/*
* It's safe to do this here, even though it's new data
* because all IO has been locked out of the block.
*
* mg_lock_writes() already took READ_WRITE_LOCK_LEVEL
* so _not_ using mg_upgrade_lock() as continutation.
*/
overwrite(mg, mg_update_metadata_after_copy);
} else
mg_full_copy(ws);
}
static int mg_lock_writes(struct dm_cache_migration *mg)
{
int r;
struct dm_cell_key_v2 key;
struct cache *cache = mg->cache;
struct dm_bio_prison_cell_v2 *prealloc;
prealloc = alloc_prison_cell(cache);
/*
* Prevent writes to the block, but allow reads to continue.
* Unless we're using an overwrite bio, in which case we lock
* everything.
*/
build_key(mg->op->oblock, oblock_succ(mg->op->oblock), &key);
r = dm_cell_lock_v2(cache->prison, &key,
mg->overwrite_bio ? READ_WRITE_LOCK_LEVEL : WRITE_LOCK_LEVEL,
prealloc, &mg->cell);
if (r < 0) {
free_prison_cell(cache, prealloc);
mg_complete(mg, false);
return r;
}
if (mg->cell != prealloc)
free_prison_cell(cache, prealloc);
if (r == 0)
mg_copy(&mg->k.ws);
else
quiesce(mg, mg_copy);
return 0;
}
static int mg_start(struct cache *cache, struct policy_work *op, struct bio *bio)
{
struct dm_cache_migration *mg;
if (!background_work_begin(cache)) {
policy_complete_background_work(cache->policy, op, false);
return -EPERM;
}
mg = alloc_migration(cache);
mg->op = op;
mg->overwrite_bio = bio;
if (!bio)
inc_io_migrations(cache);
return mg_lock_writes(mg);
}
/*
*--------------------------------------------------------------
* invalidation processing
*--------------------------------------------------------------
*/
static void invalidate_complete(struct dm_cache_migration *mg, bool success)
{
struct bio_list bios;
struct cache *cache = mg->cache;
bio_list_init(&bios);
if (dm_cell_unlock_v2(cache->prison, mg->cell, &bios))
free_prison_cell(cache, mg->cell);
if (!success && mg->overwrite_bio)
bio_io_error(mg->overwrite_bio);
free_migration(mg);
defer_bios(cache, &bios);
background_work_end(cache);
}
static void invalidate_completed(struct work_struct *ws)
{
struct dm_cache_migration *mg = ws_to_mg(ws);
invalidate_complete(mg, !mg->k.input);
}
static int invalidate_cblock(struct cache *cache, dm_cblock_t cblock)
{
int r;
r = policy_invalidate_mapping(cache->policy, cblock);
if (!r) {
r = dm_cache_remove_mapping(cache->cmd, cblock);
if (r) {
DMERR_LIMIT("%s: invalidation failed; couldn't update on disk metadata",
cache_device_name(cache));
metadata_operation_failed(cache, "dm_cache_remove_mapping", r);
}
} else if (r == -ENODATA) {
/*
* Harmless, already unmapped.
*/
r = 0;
} else
DMERR("%s: policy_invalidate_mapping failed", cache_device_name(cache));
return r;
}
static void invalidate_remove(struct work_struct *ws)
{
int r;
struct dm_cache_migration *mg = ws_to_mg(ws);
struct cache *cache = mg->cache;
r = invalidate_cblock(cache, mg->invalidate_cblock);
if (r) {
invalidate_complete(mg, false);
return;
}
init_continuation(&mg->k, invalidate_completed);
continue_after_commit(&cache->committer, &mg->k);
remap_to_origin_clear_discard(cache, mg->overwrite_bio, mg->invalidate_oblock);
mg->overwrite_bio = NULL;
schedule_commit(&cache->committer);
}
static int invalidate_lock(struct dm_cache_migration *mg)
{
int r;
struct dm_cell_key_v2 key;
struct cache *cache = mg->cache;
struct dm_bio_prison_cell_v2 *prealloc;
prealloc = alloc_prison_cell(cache);
build_key(mg->invalidate_oblock, oblock_succ(mg->invalidate_oblock), &key);
r = dm_cell_lock_v2(cache->prison, &key,
READ_WRITE_LOCK_LEVEL, prealloc, &mg->cell);
if (r < 0) {
free_prison_cell(cache, prealloc);
invalidate_complete(mg, false);
return r;
}
if (mg->cell != prealloc)
free_prison_cell(cache, prealloc);
if (r)
quiesce(mg, invalidate_remove);
else {
/*
* We can't call invalidate_remove() directly here because we
* might still be in request context.
*/
init_continuation(&mg->k, invalidate_remove);
queue_work(cache->wq, &mg->k.ws);
}
return 0;
}
static int invalidate_start(struct cache *cache, dm_cblock_t cblock,
dm_oblock_t oblock, struct bio *bio)
{
struct dm_cache_migration *mg;
if (!background_work_begin(cache))
return -EPERM;
mg = alloc_migration(cache);
mg->overwrite_bio = bio;
mg->invalidate_cblock = cblock;
mg->invalidate_oblock = oblock;
return invalidate_lock(mg);
}
/*
*--------------------------------------------------------------
* bio processing
*--------------------------------------------------------------
*/
enum busy {
IDLE,
BUSY
};
static enum busy spare_migration_bandwidth(struct cache *cache)
{
bool idle = dm_iot_idle_for(&cache->tracker, HZ);
sector_t current_volume = (atomic_read(&cache->nr_io_migrations) + 1) *
cache->sectors_per_block;
if (idle && current_volume <= cache->migration_threshold)
return IDLE;
else
return BUSY;
}
static void inc_hit_counter(struct cache *cache, struct bio *bio)
{
atomic_inc(bio_data_dir(bio) == READ ?
&cache->stats.read_hit : &cache->stats.write_hit);
}
static void inc_miss_counter(struct cache *cache, struct bio *bio)
{
atomic_inc(bio_data_dir(bio) == READ ?
&cache->stats.read_miss : &cache->stats.write_miss);
}
/*----------------------------------------------------------------*/
static int map_bio(struct cache *cache, struct bio *bio, dm_oblock_t block,
bool *commit_needed)
{
int r, data_dir;
bool rb, background_queued;
dm_cblock_t cblock;
*commit_needed = false;
rb = bio_detain_shared(cache, block, bio);
if (!rb) {
/*
* An exclusive lock is held for this block, so we have to
* wait. We set the commit_needed flag so the current
* transaction will be committed asap, allowing this lock
* to be dropped.
*/
*commit_needed = true;
return DM_MAPIO_SUBMITTED;
}
data_dir = bio_data_dir(bio);
if (optimisable_bio(cache, bio, block)) {
struct policy_work *op = NULL;
r = policy_lookup_with_work(cache->policy, block, &cblock, data_dir, true, &op);
if (unlikely(r && r != -ENOENT)) {
DMERR_LIMIT("%s: policy_lookup_with_work() failed with r = %d",
cache_device_name(cache), r);
bio_io_error(bio);
return DM_MAPIO_SUBMITTED;
}
if (r == -ENOENT && op) {
bio_drop_shared_lock(cache, bio);
BUG_ON(op->op != POLICY_PROMOTE);
mg_start(cache, op, bio);
return DM_MAPIO_SUBMITTED;
}
} else {
r = policy_lookup(cache->policy, block, &cblock, data_dir, false, &background_queued);
if (unlikely(r && r != -ENOENT)) {
DMERR_LIMIT("%s: policy_lookup() failed with r = %d",
cache_device_name(cache), r);
bio_io_error(bio);
return DM_MAPIO_SUBMITTED;
}
if (background_queued)
wake_migration_worker(cache);
}
if (r == -ENOENT) {
struct per_bio_data *pb = get_per_bio_data(bio);
/*
* Miss.
*/
inc_miss_counter(cache, bio);
if (pb->req_nr == 0) {
accounted_begin(cache, bio);
remap_to_origin_clear_discard(cache, bio, block);
} else {
/*
* This is a duplicate writethrough io that is no
* longer needed because the block has been demoted.
*/
bio_endio(bio);
return DM_MAPIO_SUBMITTED;
}
} else {
/*
* Hit.
*/
inc_hit_counter(cache, bio);
/*
* Passthrough always maps to the origin, invalidating any
* cache blocks that are written to.
*/
if (passthrough_mode(cache)) {
if (bio_data_dir(bio) == WRITE) {
bio_drop_shared_lock(cache, bio);
atomic_inc(&cache->stats.demotion);
invalidate_start(cache, cblock, block, bio);
} else
remap_to_origin_clear_discard(cache, bio, block);
} else {
if (bio_data_dir(bio) == WRITE && writethrough_mode(cache) &&
!is_dirty(cache, cblock)) {
remap_to_origin_and_cache(cache, bio, block, cblock);
accounted_begin(cache, bio);
} else
remap_to_cache_dirty(cache, bio, block, cblock);
}
}
/*
* dm core turns FUA requests into a separate payload and FLUSH req.
*/
if (bio->bi_opf & REQ_FUA) {
/*
* issue_after_commit will call accounted_begin a second time. So
* we call accounted_complete() to avoid double accounting.
*/
accounted_complete(cache, bio);
issue_after_commit(&cache->committer, bio);
*commit_needed = true;
return DM_MAPIO_SUBMITTED;
}
return DM_MAPIO_REMAPPED;
}
static bool process_bio(struct cache *cache, struct bio *bio)
{
bool commit_needed;
if (map_bio(cache, bio, get_bio_block(cache, bio), &commit_needed) == DM_MAPIO_REMAPPED)
dm_submit_bio_remap(bio, NULL);
return commit_needed;
}
/*
* A non-zero return indicates read_only or fail_io mode.
*/
static int commit(struct cache *cache, bool clean_shutdown)
{
int r;
if (get_cache_mode(cache) >= CM_READ_ONLY)
return -EINVAL;
atomic_inc(&cache->stats.commit_count);
r = dm_cache_commit(cache->cmd, clean_shutdown);
if (r)
metadata_operation_failed(cache, "dm_cache_commit", r);
return r;
}
/*
* Used by the batcher.
*/
static blk_status_t commit_op(void *context)
{
struct cache *cache = context;
if (dm_cache_changed_this_transaction(cache->cmd))
return errno_to_blk_status(commit(cache, false));
return 0;
}
/*----------------------------------------------------------------*/
static bool process_flush_bio(struct cache *cache, struct bio *bio)
{
struct per_bio_data *pb = get_per_bio_data(bio);
if (!pb->req_nr)
remap_to_origin(cache, bio);
else
remap_to_cache(cache, bio, 0);
issue_after_commit(&cache->committer, bio);
return true;
}
static bool process_discard_bio(struct cache *cache, struct bio *bio)
{
dm_dblock_t b, e;
/*
* FIXME: do we need to lock the region? Or can we just assume the
* user wont be so foolish as to issue discard concurrently with
* other IO?
*/
calc_discard_block_range(cache, bio, &b, &e);
while (b != e) {
set_discard(cache, b);
b = to_dblock(from_dblock(b) + 1);
}
if (cache->features.discard_passdown) {
remap_to_origin(cache, bio);
dm_submit_bio_remap(bio, NULL);
} else
bio_endio(bio);
return false;
}
static void process_deferred_bios(struct work_struct *ws)
{
struct cache *cache = container_of(ws, struct cache, deferred_bio_worker);
bool commit_needed = false;
struct bio_list bios;
struct bio *bio;
bio_list_init(&bios);
spin_lock_irq(&cache->lock);
bio_list_merge(&bios, &cache->deferred_bios);
bio_list_init(&cache->deferred_bios);
spin_unlock_irq(&cache->lock);
while ((bio = bio_list_pop(&bios))) {
if (bio->bi_opf & REQ_PREFLUSH)
commit_needed = process_flush_bio(cache, bio) || commit_needed;
else if (bio_op(bio) == REQ_OP_DISCARD)
commit_needed = process_discard_bio(cache, bio) || commit_needed;
else
commit_needed = process_bio(cache, bio) || commit_needed;
cond_resched();
}
if (commit_needed)
schedule_commit(&cache->committer);
}
/*
*--------------------------------------------------------------
* Main worker loop
*--------------------------------------------------------------
*/
static void requeue_deferred_bios(struct cache *cache)
{
struct bio *bio;
struct bio_list bios;
bio_list_init(&bios);
bio_list_merge(&bios, &cache->deferred_bios);
bio_list_init(&cache->deferred_bios);
while ((bio = bio_list_pop(&bios))) {
bio->bi_status = BLK_STS_DM_REQUEUE;
bio_endio(bio);
cond_resched();
}
}
/*
* We want to commit periodically so that not too much
* unwritten metadata builds up.
*/
static void do_waker(struct work_struct *ws)
{
struct cache *cache = container_of(to_delayed_work(ws), struct cache, waker);
policy_tick(cache->policy, true);
wake_migration_worker(cache);
schedule_commit(&cache->committer);
queue_delayed_work(cache->wq, &cache->waker, COMMIT_PERIOD);
}
static void check_migrations(struct work_struct *ws)
{
int r;
struct policy_work *op;
struct cache *cache = container_of(ws, struct cache, migration_worker);
enum busy b;
for (;;) {
b = spare_migration_bandwidth(cache);
r = policy_get_background_work(cache->policy, b == IDLE, &op);
if (r == -ENODATA)
break;
if (r) {
DMERR_LIMIT("%s: policy_background_work failed",
cache_device_name(cache));
break;
}
r = mg_start(cache, op, NULL);
if (r)
break;
cond_resched();
}
}
/*
*--------------------------------------------------------------
* Target methods
*--------------------------------------------------------------
*/
/*
* This function gets called on the error paths of the constructor, so we
* have to cope with a partially initialised struct.
*/
static void destroy(struct cache *cache)
{
unsigned int i;
mempool_exit(&cache->migration_pool);
if (cache->prison)
dm_bio_prison_destroy_v2(cache->prison);
cancel_delayed_work_sync(&cache->waker);
if (cache->wq)
destroy_workqueue(cache->wq);
if (cache->dirty_bitset)
free_bitset(cache->dirty_bitset);
if (cache->discard_bitset)
free_bitset(cache->discard_bitset);
if (cache->copier)
dm_kcopyd_client_destroy(cache->copier);
if (cache->cmd)
dm_cache_metadata_close(cache->cmd);
if (cache->metadata_dev)
dm_put_device(cache->ti, cache->metadata_dev);
if (cache->origin_dev)
dm_put_device(cache->ti, cache->origin_dev);
if (cache->cache_dev)
dm_put_device(cache->ti, cache->cache_dev);
if (cache->policy)
dm_cache_policy_destroy(cache->policy);
for (i = 0; i < cache->nr_ctr_args ; i++)
kfree(cache->ctr_args[i]);
kfree(cache->ctr_args);
bioset_exit(&cache->bs);
kfree(cache);
}
static void cache_dtr(struct dm_target *ti)
{
struct cache *cache = ti->private;
destroy(cache);
}
static sector_t get_dev_size(struct dm_dev *dev)
{
return bdev_nr_sectors(dev->bdev);
}
/*----------------------------------------------------------------*/
/*
* Construct a cache device mapping.
*
* cache <metadata dev> <cache dev> <origin dev> <block size>
* <#feature args> [<feature arg>]*
* <policy> <#policy args> [<policy arg>]*
*
* metadata dev : fast device holding the persistent metadata
* cache dev : fast device holding cached data blocks
* origin dev : slow device holding original data blocks
* block size : cache unit size in sectors
*
* #feature args : number of feature arguments passed
* feature args : writethrough. (The default is writeback.)
*
* policy : the replacement policy to use
* #policy args : an even number of policy arguments corresponding
* to key/value pairs passed to the policy
* policy args : key/value pairs passed to the policy
* E.g. 'sequential_threshold 1024'
* See cache-policies.txt for details.
*
* Optional feature arguments are:
* writethrough : write through caching that prohibits cache block
* content from being different from origin block content.
* Without this argument, the default behaviour is to write
* back cache block contents later for performance reasons,
* so they may differ from the corresponding origin blocks.
*/
struct cache_args {
struct dm_target *ti;
struct dm_dev *metadata_dev;
struct dm_dev *cache_dev;
sector_t cache_sectors;
struct dm_dev *origin_dev;
sector_t origin_sectors;
uint32_t block_size;
const char *policy_name;
int policy_argc;
const char **policy_argv;
struct cache_features features;
};
static void destroy_cache_args(struct cache_args *ca)
{
if (ca->metadata_dev)
dm_put_device(ca->ti, ca->metadata_dev);
if (ca->cache_dev)
dm_put_device(ca->ti, ca->cache_dev);
if (ca->origin_dev)
dm_put_device(ca->ti, ca->origin_dev);
kfree(ca);
}
static bool at_least_one_arg(struct dm_arg_set *as, char **error)
{
if (!as->argc) {
*error = "Insufficient args";
return false;
}
return true;
}
static int parse_metadata_dev(struct cache_args *ca, struct dm_arg_set *as,
char **error)
{
int r;
sector_t metadata_dev_size;
if (!at_least_one_arg(as, error))
return -EINVAL;
r = dm_get_device(ca->ti, dm_shift_arg(as),
BLK_OPEN_READ | BLK_OPEN_WRITE, &ca->metadata_dev);
if (r) {
*error = "Error opening metadata device";
return r;
}
metadata_dev_size = get_dev_size(ca->metadata_dev);
if (metadata_dev_size > DM_CACHE_METADATA_MAX_SECTORS_WARNING)
DMWARN("Metadata device %pg is larger than %u sectors: excess space will not be used.",
ca->metadata_dev->bdev, THIN_METADATA_MAX_SECTORS);
return 0;
}
static int parse_cache_dev(struct cache_args *ca, struct dm_arg_set *as,
char **error)
{
int r;
if (!at_least_one_arg(as, error))
return -EINVAL;
r = dm_get_device(ca->ti, dm_shift_arg(as),
BLK_OPEN_READ | BLK_OPEN_WRITE, &ca->cache_dev);
if (r) {
*error = "Error opening cache device";
return r;
}
ca->cache_sectors = get_dev_size(ca->cache_dev);
return 0;
}
static int parse_origin_dev(struct cache_args *ca, struct dm_arg_set *as,
char **error)
{
int r;
if (!at_least_one_arg(as, error))
return -EINVAL;
r = dm_get_device(ca->ti, dm_shift_arg(as),
BLK_OPEN_READ | BLK_OPEN_WRITE, &ca->origin_dev);
if (r) {
*error = "Error opening origin device";
return r;
}
ca->origin_sectors = get_dev_size(ca->origin_dev);
if (ca->ti->len > ca->origin_sectors) {
*error = "Device size larger than cached device";
return -EINVAL;
}
return 0;
}
static int parse_block_size(struct cache_args *ca, struct dm_arg_set *as,
char **error)
{
unsigned long block_size;
if (!at_least_one_arg(as, error))
return -EINVAL;
if (kstrtoul(dm_shift_arg(as), 10, &block_size) || !block_size ||
block_size < DATA_DEV_BLOCK_SIZE_MIN_SECTORS ||
block_size > DATA_DEV_BLOCK_SIZE_MAX_SECTORS ||
block_size & (DATA_DEV_BLOCK_SIZE_MIN_SECTORS - 1)) {
*error = "Invalid data block size";
return -EINVAL;
}
if (block_size > ca->cache_sectors) {
*error = "Data block size is larger than the cache device";
return -EINVAL;
}
ca->block_size = block_size;
return 0;
}
static void init_features(struct cache_features *cf)
{
cf->mode = CM_WRITE;
cf->io_mode = CM_IO_WRITEBACK;
cf->metadata_version = 1;
cf->discard_passdown = true;
}
static int parse_features(struct cache_args *ca, struct dm_arg_set *as,
char **error)
{
static const struct dm_arg _args[] = {
{0, 3, "Invalid number of cache feature arguments"},
};
int r, mode_ctr = 0;
unsigned int argc;
const char *arg;
struct cache_features *cf = &ca->features;
init_features(cf);
r = dm_read_arg_group(_args, as, &argc, error);
if (r)
return -EINVAL;
while (argc--) {
arg = dm_shift_arg(as);
if (!strcasecmp(arg, "writeback")) {
cf->io_mode = CM_IO_WRITEBACK;
mode_ctr++;
}
else if (!strcasecmp(arg, "writethrough")) {
cf->io_mode = CM_IO_WRITETHROUGH;
mode_ctr++;
}
else if (!strcasecmp(arg, "passthrough")) {
cf->io_mode = CM_IO_PASSTHROUGH;
mode_ctr++;
}
else if (!strcasecmp(arg, "metadata2"))
cf->metadata_version = 2;
else if (!strcasecmp(arg, "no_discard_passdown"))
cf->discard_passdown = false;
else {
*error = "Unrecognised cache feature requested";
return -EINVAL;
}
}
if (mode_ctr > 1) {
*error = "Duplicate cache io_mode features requested";
return -EINVAL;
}
return 0;
}
static int parse_policy(struct cache_args *ca, struct dm_arg_set *as,
char **error)
{
static const struct dm_arg _args[] = {
{0, 1024, "Invalid number of policy arguments"},
};
int r;
if (!at_least_one_arg(as, error))
return -EINVAL;
ca->policy_name = dm_shift_arg(as);
r = dm_read_arg_group(_args, as, &ca->policy_argc, error);
if (r)
return -EINVAL;
ca->policy_argv = (const char **)as->argv;
dm_consume_args(as, ca->policy_argc);
return 0;
}
static int parse_cache_args(struct cache_args *ca, int argc, char **argv,
char **error)
{
int r;
struct dm_arg_set as;
as.argc = argc;
as.argv = argv;
r = parse_metadata_dev(ca, &as, error);
if (r)
return r;
r = parse_cache_dev(ca, &as, error);
if (r)
return r;
r = parse_origin_dev(ca, &as, error);
if (r)
return r;
r = parse_block_size(ca, &as, error);
if (r)
return r;
r = parse_features(ca, &as, error);
if (r)
return r;
r = parse_policy(ca, &as, error);
if (r)
return r;
return 0;
}
/*----------------------------------------------------------------*/
static struct kmem_cache *migration_cache;
#define NOT_CORE_OPTION 1
static int process_config_option(struct cache *cache, const char *key, const char *value)
{
unsigned long tmp;
if (!strcasecmp(key, "migration_threshold")) {
if (kstrtoul(value, 10, &tmp))
return -EINVAL;
cache->migration_threshold = tmp;
return 0;
}
return NOT_CORE_OPTION;
}
static int set_config_value(struct cache *cache, const char *key, const char *value)
{
int r = process_config_option(cache, key, value);
if (r == NOT_CORE_OPTION)
r = policy_set_config_value(cache->policy, key, value);
if (r)
DMWARN("bad config value for %s: %s", key, value);
return r;
}
static int set_config_values(struct cache *cache, int argc, const char **argv)
{
int r = 0;
if (argc & 1) {
DMWARN("Odd number of policy arguments given but they should be <key> <value> pairs.");
return -EINVAL;
}
while (argc) {
r = set_config_value(cache, argv[0], argv[1]);
if (r)
break;
argc -= 2;
argv += 2;
}
return r;
}
static int create_cache_policy(struct cache *cache, struct cache_args *ca,
char **error)
{
struct dm_cache_policy *p = dm_cache_policy_create(ca->policy_name,
cache->cache_size,
cache->origin_sectors,
cache->sectors_per_block);
if (IS_ERR(p)) {
*error = "Error creating cache's policy";
return PTR_ERR(p);
}
cache->policy = p;
BUG_ON(!cache->policy);
return 0;
}
/*
* We want the discard block size to be at least the size of the cache
* block size and have no more than 2^14 discard blocks across the origin.
*/
#define MAX_DISCARD_BLOCKS (1 << 14)
static bool too_many_discard_blocks(sector_t discard_block_size,
sector_t origin_size)
{
(void) sector_div(origin_size, discard_block_size);
return origin_size > MAX_DISCARD_BLOCKS;
}
static sector_t calculate_discard_block_size(sector_t cache_block_size,
sector_t origin_size)
{
sector_t discard_block_size = cache_block_size;
if (origin_size)
while (too_many_discard_blocks(discard_block_size, origin_size))
discard_block_size *= 2;
return discard_block_size;
}
static void set_cache_size(struct cache *cache, dm_cblock_t size)
{
dm_block_t nr_blocks = from_cblock(size);
if (nr_blocks > (1 << 20) && cache->cache_size != size)
DMWARN_LIMIT("You have created a cache device with a lot of individual cache blocks (%llu)\n"
"All these mappings can consume a lot of kernel memory, and take some time to read/write.\n"
"Please consider increasing the cache block size to reduce the overall cache block count.",
(unsigned long long) nr_blocks);
cache->cache_size = size;
}
#define DEFAULT_MIGRATION_THRESHOLD 2048
static int cache_create(struct cache_args *ca, struct cache **result)
{
int r = 0;
char **error = &ca->ti->error;
struct cache *cache;
struct dm_target *ti = ca->ti;
dm_block_t origin_blocks;
struct dm_cache_metadata *cmd;
bool may_format = ca->features.mode == CM_WRITE;
cache = kzalloc(sizeof(*cache), GFP_KERNEL);
if (!cache)
return -ENOMEM;
cache->ti = ca->ti;
ti->private = cache;
ti->accounts_remapped_io = true;
ti->num_flush_bios = 2;
ti->flush_supported = true;
ti->num_discard_bios = 1;
ti->discards_supported = true;
ti->per_io_data_size = sizeof(struct per_bio_data);
cache->features = ca->features;
if (writethrough_mode(cache)) {
/* Create bioset for writethrough bios issued to origin */
r = bioset_init(&cache->bs, BIO_POOL_SIZE, 0, 0);
if (r)
goto bad;
}
cache->metadata_dev = ca->metadata_dev;
cache->origin_dev = ca->origin_dev;
cache->cache_dev = ca->cache_dev;
ca->metadata_dev = ca->origin_dev = ca->cache_dev = NULL;
origin_blocks = cache->origin_sectors = ca->origin_sectors;
origin_blocks = block_div(origin_blocks, ca->block_size);
cache->origin_blocks = to_oblock(origin_blocks);
cache->sectors_per_block = ca->block_size;
if (dm_set_target_max_io_len(ti, cache->sectors_per_block)) {
r = -EINVAL;
goto bad;
}
if (ca->block_size & (ca->block_size - 1)) {
dm_block_t cache_size = ca->cache_sectors;
cache->sectors_per_block_shift = -1;
cache_size = block_div(cache_size, ca->block_size);
set_cache_size(cache, to_cblock(cache_size));
} else {
cache->sectors_per_block_shift = __ffs(ca->block_size);
set_cache_size(cache, to_cblock(ca->cache_sectors >> cache->sectors_per_block_shift));
}
r = create_cache_policy(cache, ca, error);
if (r)
goto bad;
cache->policy_nr_args = ca->policy_argc;
cache->migration_threshold = DEFAULT_MIGRATION_THRESHOLD;
r = set_config_values(cache, ca->policy_argc, ca->policy_argv);
if (r) {
*error = "Error setting cache policy's config values";
goto bad;
}
cmd = dm_cache_metadata_open(cache->metadata_dev->bdev,
ca->block_size, may_format,
dm_cache_policy_get_hint_size(cache->policy),
ca->features.metadata_version);
if (IS_ERR(cmd)) {
*error = "Error creating metadata object";
r = PTR_ERR(cmd);
goto bad;
}
cache->cmd = cmd;
set_cache_mode(cache, CM_WRITE);
if (get_cache_mode(cache) != CM_WRITE) {
*error = "Unable to get write access to metadata, please check/repair metadata.";
r = -EINVAL;
goto bad;
}
if (passthrough_mode(cache)) {
bool all_clean;
r = dm_cache_metadata_all_clean(cache->cmd, &all_clean);
if (r) {
*error = "dm_cache_metadata_all_clean() failed";
goto bad;
}
if (!all_clean) {
*error = "Cannot enter passthrough mode unless all blocks are clean";
r = -EINVAL;
goto bad;
}
policy_allow_migrations(cache->policy, false);
}
spin_lock_init(&cache->lock);
bio_list_init(&cache->deferred_bios);
atomic_set(&cache->nr_allocated_migrations, 0);
atomic_set(&cache->nr_io_migrations, 0);
init_waitqueue_head(&cache->migration_wait);
r = -ENOMEM;
atomic_set(&cache->nr_dirty, 0);
cache->dirty_bitset = alloc_bitset(from_cblock(cache->cache_size));
if (!cache->dirty_bitset) {
*error = "could not allocate dirty bitset";
goto bad;
}
clear_bitset(cache->dirty_bitset, from_cblock(cache->cache_size));
cache->discard_block_size =
calculate_discard_block_size(cache->sectors_per_block,
cache->origin_sectors);
cache->discard_nr_blocks = to_dblock(dm_sector_div_up(cache->origin_sectors,
cache->discard_block_size));
cache->discard_bitset = alloc_bitset(from_dblock(cache->discard_nr_blocks));
if (!cache->discard_bitset) {
*error = "could not allocate discard bitset";
goto bad;
}
clear_bitset(cache->discard_bitset, from_dblock(cache->discard_nr_blocks));
cache->copier = dm_kcopyd_client_create(&dm_kcopyd_throttle);
if (IS_ERR(cache->copier)) {
*error = "could not create kcopyd client";
r = PTR_ERR(cache->copier);
goto bad;
}
cache->wq = alloc_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM, 0);
if (!cache->wq) {
*error = "could not create workqueue for metadata object";
goto bad;
}
INIT_WORK(&cache->deferred_bio_worker, process_deferred_bios);
INIT_WORK(&cache->migration_worker, check_migrations);
INIT_DELAYED_WORK(&cache->waker, do_waker);
cache->prison = dm_bio_prison_create_v2(cache->wq);
if (!cache->prison) {
*error = "could not create bio prison";
goto bad;
}
r = mempool_init_slab_pool(&cache->migration_pool, MIGRATION_POOL_SIZE,
migration_cache);
if (r) {
*error = "Error creating cache's migration mempool";
goto bad;
}
cache->need_tick_bio = true;
cache->sized = false;
cache->invalidate = false;
cache->commit_requested = false;
cache->loaded_mappings = false;
cache->loaded_discards = false;
load_stats(cache);
atomic_set(&cache->stats.demotion, 0);
atomic_set(&cache->stats.promotion, 0);
atomic_set(&cache->stats.copies_avoided, 0);
atomic_set(&cache->stats.cache_cell_clash, 0);
atomic_set(&cache->stats.commit_count, 0);
atomic_set(&cache->stats.discard_count, 0);
spin_lock_init(&cache->invalidation_lock);
INIT_LIST_HEAD(&cache->invalidation_requests);
batcher_init(&cache->committer, commit_op, cache,
issue_op, cache, cache->wq);
dm_iot_init(&cache->tracker);
init_rwsem(&cache->background_work_lock);
prevent_background_work(cache);
*result = cache;
return 0;
bad:
destroy(cache);
return r;
}
static int copy_ctr_args(struct cache *cache, int argc, const char **argv)
{
unsigned int i;
const char **copy;
copy = kcalloc(argc, sizeof(*copy), GFP_KERNEL);
if (!copy)
return -ENOMEM;
for (i = 0; i < argc; i++) {
copy[i] = kstrdup(argv[i], GFP_KERNEL);
if (!copy[i]) {
while (i--)
kfree(copy[i]);
kfree(copy);
return -ENOMEM;
}
}
cache->nr_ctr_args = argc;
cache->ctr_args = copy;
return 0;
}
static int cache_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
int r = -EINVAL;
struct cache_args *ca;
struct cache *cache = NULL;
ca = kzalloc(sizeof(*ca), GFP_KERNEL);
if (!ca) {
ti->error = "Error allocating memory for cache";
return -ENOMEM;
}
ca->ti = ti;
r = parse_cache_args(ca, argc, argv, &ti->error);
if (r)
goto out;
r = cache_create(ca, &cache);
if (r)
goto out;
r = copy_ctr_args(cache, argc - 3, (const char **)argv + 3);
if (r) {
destroy(cache);
goto out;
}
ti->private = cache;
out:
destroy_cache_args(ca);
return r;
}
/*----------------------------------------------------------------*/
static int cache_map(struct dm_target *ti, struct bio *bio)
{
struct cache *cache = ti->private;
int r;
bool commit_needed;
dm_oblock_t block = get_bio_block(cache, bio);
init_per_bio_data(bio);
if (unlikely(from_oblock(block) >= from_oblock(cache->origin_blocks))) {
/*
* This can only occur if the io goes to a partial block at
* the end of the origin device. We don't cache these.
* Just remap to the origin and carry on.
*/
remap_to_origin(cache, bio);
accounted_begin(cache, bio);
return DM_MAPIO_REMAPPED;
}
if (discard_or_flush(bio)) {
defer_bio(cache, bio);
return DM_MAPIO_SUBMITTED;
}
r = map_bio(cache, bio, block, &commit_needed);
if (commit_needed)
schedule_commit(&cache->committer);
return r;
}
static int cache_end_io(struct dm_target *ti, struct bio *bio, blk_status_t *error)
{
struct cache *cache = ti->private;
unsigned long flags;
struct per_bio_data *pb = get_per_bio_data(bio);
if (pb->tick) {
policy_tick(cache->policy, false);
spin_lock_irqsave(&cache->lock, flags);
cache->need_tick_bio = true;
spin_unlock_irqrestore(&cache->lock, flags);
}
bio_drop_shared_lock(cache, bio);
accounted_complete(cache, bio);
return DM_ENDIO_DONE;
}
static int write_dirty_bitset(struct cache *cache)
{
int r;
if (get_cache_mode(cache) >= CM_READ_ONLY)
return -EINVAL;
r = dm_cache_set_dirty_bits(cache->cmd, from_cblock(cache->cache_size), cache->dirty_bitset);
if (r)
metadata_operation_failed(cache, "dm_cache_set_dirty_bits", r);
return r;
}
static int write_discard_bitset(struct cache *cache)
{
unsigned int i, r;
if (get_cache_mode(cache) >= CM_READ_ONLY)
return -EINVAL;
r = dm_cache_discard_bitset_resize(cache->cmd, cache->discard_block_size,
cache->discard_nr_blocks);
if (r) {
DMERR("%s: could not resize on-disk discard bitset", cache_device_name(cache));
metadata_operation_failed(cache, "dm_cache_discard_bitset_resize", r);
return r;
}
for (i = 0; i < from_dblock(cache->discard_nr_blocks); i++) {
r = dm_cache_set_discard(cache->cmd, to_dblock(i),
is_discarded(cache, to_dblock(i)));
if (r) {
metadata_operation_failed(cache, "dm_cache_set_discard", r);
return r;
}
}
return 0;
}
static int write_hints(struct cache *cache)
{
int r;
if (get_cache_mode(cache) >= CM_READ_ONLY)
return -EINVAL;
r = dm_cache_write_hints(cache->cmd, cache->policy);
if (r) {
metadata_operation_failed(cache, "dm_cache_write_hints", r);
return r;
}
return 0;
}
/*
* returns true on success
*/
static bool sync_metadata(struct cache *cache)
{
int r1, r2, r3, r4;
r1 = write_dirty_bitset(cache);
if (r1)
DMERR("%s: could not write dirty bitset", cache_device_name(cache));
r2 = write_discard_bitset(cache);
if (r2)
DMERR("%s: could not write discard bitset", cache_device_name(cache));
save_stats(cache);
r3 = write_hints(cache);
if (r3)
DMERR("%s: could not write hints", cache_device_name(cache));
/*
* If writing the above metadata failed, we still commit, but don't
* set the clean shutdown flag. This will effectively force every
* dirty bit to be set on reload.
*/
r4 = commit(cache, !r1 && !r2 && !r3);
if (r4)
DMERR("%s: could not write cache metadata", cache_device_name(cache));
return !r1 && !r2 && !r3 && !r4;
}
static void cache_postsuspend(struct dm_target *ti)
{
struct cache *cache = ti->private;
prevent_background_work(cache);
BUG_ON(atomic_read(&cache->nr_io_migrations));
cancel_delayed_work_sync(&cache->waker);
drain_workqueue(cache->wq);
WARN_ON(cache->tracker.in_flight);
/*
* If it's a flush suspend there won't be any deferred bios, so this
* call is harmless.
*/
requeue_deferred_bios(cache);
if (get_cache_mode(cache) == CM_WRITE)
(void) sync_metadata(cache);
}
static int load_mapping(void *context, dm_oblock_t oblock, dm_cblock_t cblock,
bool dirty, uint32_t hint, bool hint_valid)
{
struct cache *cache = context;
if (dirty) {
set_bit(from_cblock(cblock), cache->dirty_bitset);
atomic_inc(&cache->nr_dirty);
} else
clear_bit(from_cblock(cblock), cache->dirty_bitset);
return policy_load_mapping(cache->policy, oblock, cblock, dirty, hint, hint_valid);
}
/*
* The discard block size in the on disk metadata is not
* necessarily the same as we're currently using. So we have to
* be careful to only set the discarded attribute if we know it
* covers a complete block of the new size.
*/
struct discard_load_info {
struct cache *cache;
/*
* These blocks are sized using the on disk dblock size, rather
* than the current one.
*/
dm_block_t block_size;
dm_block_t discard_begin, discard_end;
};
static void discard_load_info_init(struct cache *cache,
struct discard_load_info *li)
{
li->cache = cache;
li->discard_begin = li->discard_end = 0;
}
static void set_discard_range(struct discard_load_info *li)
{
sector_t b, e;
if (li->discard_begin == li->discard_end)
return;
/*
* Convert to sectors.
*/
b = li->discard_begin * li->block_size;
e = li->discard_end * li->block_size;
/*
* Then convert back to the current dblock size.
*/
b = dm_sector_div_up(b, li->cache->discard_block_size);
sector_div(e, li->cache->discard_block_size);
/*
* The origin may have shrunk, so we need to check we're still in
* bounds.
*/
if (e > from_dblock(li->cache->discard_nr_blocks))
e = from_dblock(li->cache->discard_nr_blocks);
for (; b < e; b++)
set_discard(li->cache, to_dblock(b));
}
static int load_discard(void *context, sector_t discard_block_size,
dm_dblock_t dblock, bool discard)
{
struct discard_load_info *li = context;
li->block_size = discard_block_size;
if (discard) {
if (from_dblock(dblock) == li->discard_end)
/*
* We're already in a discard range, just extend it.
*/
li->discard_end = li->discard_end + 1ULL;
else {
/*
* Emit the old range and start a new one.
*/
set_discard_range(li);
li->discard_begin = from_dblock(dblock);
li->discard_end = li->discard_begin + 1ULL;
}
} else {
set_discard_range(li);
li->discard_begin = li->discard_end = 0;
}
return 0;
}
static dm_cblock_t get_cache_dev_size(struct cache *cache)
{
sector_t size = get_dev_size(cache->cache_dev);
(void) sector_div(size, cache->sectors_per_block);
return to_cblock(size);
}
static bool can_resize(struct cache *cache, dm_cblock_t new_size)
{
if (from_cblock(new_size) > from_cblock(cache->cache_size)) {
if (cache->sized) {
DMERR("%s: unable to extend cache due to missing cache table reload",
cache_device_name(cache));
return false;
}
}
/*
* We can't drop a dirty block when shrinking the cache.
*/
while (from_cblock(new_size) < from_cblock(cache->cache_size)) {
new_size = to_cblock(from_cblock(new_size) + 1);
if (is_dirty(cache, new_size)) {
DMERR("%s: unable to shrink cache; cache block %llu is dirty",
cache_device_name(cache),
(unsigned long long) from_cblock(new_size));
return false;
}
}
return true;
}
static int resize_cache_dev(struct cache *cache, dm_cblock_t new_size)
{
int r;
r = dm_cache_resize(cache->cmd, new_size);
if (r) {
DMERR("%s: could not resize cache metadata", cache_device_name(cache));
metadata_operation_failed(cache, "dm_cache_resize", r);
return r;
}
set_cache_size(cache, new_size);
return 0;
}
static int cache_preresume(struct dm_target *ti)
{
int r = 0;
struct cache *cache = ti->private;
dm_cblock_t csize = get_cache_dev_size(cache);
/*
* Check to see if the cache has resized.
*/
if (!cache->sized) {
r = resize_cache_dev(cache, csize);
if (r)
return r;
cache->sized = true;
} else if (csize != cache->cache_size) {
if (!can_resize(cache, csize))
return -EINVAL;
r = resize_cache_dev(cache, csize);
if (r)
return r;
}
if (!cache->loaded_mappings) {
r = dm_cache_load_mappings(cache->cmd, cache->policy,
load_mapping, cache);
if (r) {
DMERR("%s: could not load cache mappings", cache_device_name(cache));
metadata_operation_failed(cache, "dm_cache_load_mappings", r);
return r;
}
cache->loaded_mappings = true;
}
if (!cache->loaded_discards) {
struct discard_load_info li;
/*
* The discard bitset could have been resized, or the
* discard block size changed. To be safe we start by
* setting every dblock to not discarded.
*/
clear_bitset(cache->discard_bitset, from_dblock(cache->discard_nr_blocks));
discard_load_info_init(cache, &li);
r = dm_cache_load_discards(cache->cmd, load_discard, &li);
if (r) {
DMERR("%s: could not load origin discards", cache_device_name(cache));
metadata_operation_failed(cache, "dm_cache_load_discards", r);
return r;
}
set_discard_range(&li);
cache->loaded_discards = true;
}
return r;
}
static void cache_resume(struct dm_target *ti)
{
struct cache *cache = ti->private;
cache->need_tick_bio = true;
allow_background_work(cache);
do_waker(&cache->waker.work);
}
static void emit_flags(struct cache *cache, char *result,
unsigned int maxlen, ssize_t *sz_ptr)
{
ssize_t sz = *sz_ptr;
struct cache_features *cf = &cache->features;
unsigned int count = (cf->metadata_version == 2) + !cf->discard_passdown + 1;
DMEMIT("%u ", count);
if (cf->metadata_version == 2)
DMEMIT("metadata2 ");
if (writethrough_mode(cache))
DMEMIT("writethrough ");
else if (passthrough_mode(cache))
DMEMIT("passthrough ");
else if (writeback_mode(cache))
DMEMIT("writeback ");
else {
DMEMIT("unknown ");
DMERR("%s: internal error: unknown io mode: %d",
cache_device_name(cache), (int) cf->io_mode);
}
if (!cf->discard_passdown)
DMEMIT("no_discard_passdown ");
*sz_ptr = sz;
}
/*
* Status format:
*
* <metadata block size> <#used metadata blocks>/<#total metadata blocks>
* <cache block size> <#used cache blocks>/<#total cache blocks>
* <#read hits> <#read misses> <#write hits> <#write misses>
* <#demotions> <#promotions> <#dirty>
* <#features> <features>*
* <#core args> <core args>
* <policy name> <#policy args> <policy args>* <cache metadata mode> <needs_check>
*/
static void cache_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
int r = 0;
unsigned int i;
ssize_t sz = 0;
dm_block_t nr_free_blocks_metadata = 0;
dm_block_t nr_blocks_metadata = 0;
char buf[BDEVNAME_SIZE];
struct cache *cache = ti->private;
dm_cblock_t residency;
bool needs_check;
switch (type) {
case STATUSTYPE_INFO:
if (get_cache_mode(cache) == CM_FAIL) {
DMEMIT("Fail");
break;
}
/* Commit to ensure statistics aren't out-of-date */
if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti))
(void) commit(cache, false);
r = dm_cache_get_free_metadata_block_count(cache->cmd, &nr_free_blocks_metadata);
if (r) {
DMERR("%s: dm_cache_get_free_metadata_block_count returned %d",
cache_device_name(cache), r);
goto err;
}
r = dm_cache_get_metadata_dev_size(cache->cmd, &nr_blocks_metadata);
if (r) {
DMERR("%s: dm_cache_get_metadata_dev_size returned %d",
cache_device_name(cache), r);
goto err;
}
residency = policy_residency(cache->policy);
DMEMIT("%u %llu/%llu %llu %llu/%llu %u %u %u %u %u %u %lu ",
(unsigned int)DM_CACHE_METADATA_BLOCK_SIZE,
(unsigned long long)(nr_blocks_metadata - nr_free_blocks_metadata),
(unsigned long long)nr_blocks_metadata,
(unsigned long long)cache->sectors_per_block,
(unsigned long long) from_cblock(residency),
(unsigned long long) from_cblock(cache->cache_size),
(unsigned int) atomic_read(&cache->stats.read_hit),
(unsigned int) atomic_read(&cache->stats.read_miss),
(unsigned int) atomic_read(&cache->stats.write_hit),
(unsigned int) atomic_read(&cache->stats.write_miss),
(unsigned int) atomic_read(&cache->stats.demotion),
(unsigned int) atomic_read(&cache->stats.promotion),
(unsigned long) atomic_read(&cache->nr_dirty));
emit_flags(cache, result, maxlen, &sz);
DMEMIT("2 migration_threshold %llu ", (unsigned long long) cache->migration_threshold);
DMEMIT("%s ", dm_cache_policy_get_name(cache->policy));
if (sz < maxlen) {
r = policy_emit_config_values(cache->policy, result, maxlen, &sz);
if (r)
DMERR("%s: policy_emit_config_values returned %d",
cache_device_name(cache), r);
}
if (get_cache_mode(cache) == CM_READ_ONLY)
DMEMIT("ro ");
else
DMEMIT("rw ");
r = dm_cache_metadata_needs_check(cache->cmd, &needs_check);
if (r || needs_check)
DMEMIT("needs_check ");
else
DMEMIT("- ");
break;
case STATUSTYPE_TABLE:
format_dev_t(buf, cache->metadata_dev->bdev->bd_dev);
DMEMIT("%s ", buf);
format_dev_t(buf, cache->cache_dev->bdev->bd_dev);
DMEMIT("%s ", buf);
format_dev_t(buf, cache->origin_dev->bdev->bd_dev);
DMEMIT("%s", buf);
for (i = 0; i < cache->nr_ctr_args - 1; i++)
DMEMIT(" %s", cache->ctr_args[i]);
if (cache->nr_ctr_args)
DMEMIT(" %s", cache->ctr_args[cache->nr_ctr_args - 1]);
break;
case STATUSTYPE_IMA:
DMEMIT_TARGET_NAME_VERSION(ti->type);
if (get_cache_mode(cache) == CM_FAIL)
DMEMIT(",metadata_mode=fail");
else if (get_cache_mode(cache) == CM_READ_ONLY)
DMEMIT(",metadata_mode=ro");
else
DMEMIT(",metadata_mode=rw");
format_dev_t(buf, cache->metadata_dev->bdev->bd_dev);
DMEMIT(",cache_metadata_device=%s", buf);
format_dev_t(buf, cache->cache_dev->bdev->bd_dev);
DMEMIT(",cache_device=%s", buf);
format_dev_t(buf, cache->origin_dev->bdev->bd_dev);
DMEMIT(",cache_origin_device=%s", buf);
DMEMIT(",writethrough=%c", writethrough_mode(cache) ? 'y' : 'n');
DMEMIT(",writeback=%c", writeback_mode(cache) ? 'y' : 'n');
DMEMIT(",passthrough=%c", passthrough_mode(cache) ? 'y' : 'n');
DMEMIT(",metadata2=%c", cache->features.metadata_version == 2 ? 'y' : 'n');
DMEMIT(",no_discard_passdown=%c", cache->features.discard_passdown ? 'n' : 'y');
DMEMIT(";");
break;
}
return;
err:
DMEMIT("Error");
}
/*
* Defines a range of cblocks, begin to (end - 1) are in the range. end is
* the one-past-the-end value.
*/
struct cblock_range {
dm_cblock_t begin;
dm_cblock_t end;
};
/*
* A cache block range can take two forms:
*
* i) A single cblock, eg. '3456'
* ii) A begin and end cblock with a dash between, eg. 123-234
*/
static int parse_cblock_range(struct cache *cache, const char *str,
struct cblock_range *result)
{
char dummy;
uint64_t b, e;
int r;
/*
* Try and parse form (ii) first.
*/
r = sscanf(str, "%llu-%llu%c", &b, &e, &dummy);
if (r < 0)
return r;
if (r == 2) {
result->begin = to_cblock(b);
result->end = to_cblock(e);
return 0;
}
/*
* That didn't work, try form (i).
*/
r = sscanf(str, "%llu%c", &b, &dummy);
if (r < 0)
return r;
if (r == 1) {
result->begin = to_cblock(b);
result->end = to_cblock(from_cblock(result->begin) + 1u);
return 0;
}
DMERR("%s: invalid cblock range '%s'", cache_device_name(cache), str);
return -EINVAL;
}
static int validate_cblock_range(struct cache *cache, struct cblock_range *range)
{
uint64_t b = from_cblock(range->begin);
uint64_t e = from_cblock(range->end);
uint64_t n = from_cblock(cache->cache_size);
if (b >= n) {
DMERR("%s: begin cblock out of range: %llu >= %llu",
cache_device_name(cache), b, n);
return -EINVAL;
}
if (e > n) {
DMERR("%s: end cblock out of range: %llu > %llu",
cache_device_name(cache), e, n);
return -EINVAL;
}
if (b >= e) {
DMERR("%s: invalid cblock range: %llu >= %llu",
cache_device_name(cache), b, e);
return -EINVAL;
}
return 0;
}
static inline dm_cblock_t cblock_succ(dm_cblock_t b)
{
return to_cblock(from_cblock(b) + 1);
}
static int request_invalidation(struct cache *cache, struct cblock_range *range)
{
int r = 0;
/*
* We don't need to do any locking here because we know we're in
* passthrough mode. There's is potential for a race between an
* invalidation triggered by an io and an invalidation message. This
* is harmless, we must not worry if the policy call fails.
*/
while (range->begin != range->end) {
r = invalidate_cblock(cache, range->begin);
if (r)
return r;
range->begin = cblock_succ(range->begin);
}
cache->commit_requested = true;
return r;
}
static int process_invalidate_cblocks_message(struct cache *cache, unsigned int count,
const char **cblock_ranges)
{
int r = 0;
unsigned int i;
struct cblock_range range;
if (!passthrough_mode(cache)) {
DMERR("%s: cache has to be in passthrough mode for invalidation",
cache_device_name(cache));
return -EPERM;
}
for (i = 0; i < count; i++) {
r = parse_cblock_range(cache, cblock_ranges[i], &range);
if (r)
break;
r = validate_cblock_range(cache, &range);
if (r)
break;
/*
* Pass begin and end origin blocks to the worker and wake it.
*/
r = request_invalidation(cache, &range);
if (r)
break;
}
return r;
}
/*
* Supports
* "<key> <value>"
* and
* "invalidate_cblocks [(<begin>)|(<begin>-<end>)]*
*
* The key migration_threshold is supported by the cache target core.
*/
static int cache_message(struct dm_target *ti, unsigned int argc, char **argv,
char *result, unsigned int maxlen)
{
struct cache *cache = ti->private;
if (!argc)
return -EINVAL;
if (get_cache_mode(cache) >= CM_READ_ONLY) {
DMERR("%s: unable to service cache target messages in READ_ONLY or FAIL mode",
cache_device_name(cache));
return -EOPNOTSUPP;
}
if (!strcasecmp(argv[0], "invalidate_cblocks"))
return process_invalidate_cblocks_message(cache, argc - 1, (const char **) argv + 1);
if (argc != 2)
return -EINVAL;
return set_config_value(cache, argv[0], argv[1]);
}
static int cache_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
int r = 0;
struct cache *cache = ti->private;
r = fn(ti, cache->cache_dev, 0, get_dev_size(cache->cache_dev), data);
if (!r)
r = fn(ti, cache->origin_dev, 0, ti->len, data);
return r;
}
/*
* If discard_passdown was enabled verify that the origin device
* supports discards. Disable discard_passdown if not.
*/
static void disable_passdown_if_not_supported(struct cache *cache)
{
struct block_device *origin_bdev = cache->origin_dev->bdev;
struct queue_limits *origin_limits = &bdev_get_queue(origin_bdev)->limits;
const char *reason = NULL;
if (!cache->features.discard_passdown)
return;
if (!bdev_max_discard_sectors(origin_bdev))
reason = "discard unsupported";
else if (origin_limits->max_discard_sectors < cache->sectors_per_block)
reason = "max discard sectors smaller than a block";
if (reason) {
DMWARN("Origin device (%pg) %s: Disabling discard passdown.",
origin_bdev, reason);
cache->features.discard_passdown = false;
}
}
static void set_discard_limits(struct cache *cache, struct queue_limits *limits)
{
struct block_device *origin_bdev = cache->origin_dev->bdev;
struct queue_limits *origin_limits = &bdev_get_queue(origin_bdev)->limits;
if (!cache->features.discard_passdown) {
/* No passdown is done so setting own virtual limits */
limits->max_discard_sectors = min_t(sector_t, cache->discard_block_size * 1024,
cache->origin_sectors);
limits->discard_granularity = cache->discard_block_size << SECTOR_SHIFT;
return;
}
/*
* cache_iterate_devices() is stacking both origin and fast device limits
* but discards aren't passed to fast device, so inherit origin's limits.
*/
limits->max_discard_sectors = origin_limits->max_discard_sectors;
limits->max_hw_discard_sectors = origin_limits->max_hw_discard_sectors;
limits->discard_granularity = origin_limits->discard_granularity;
limits->discard_alignment = origin_limits->discard_alignment;
limits->discard_misaligned = origin_limits->discard_misaligned;
}
static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
struct cache *cache = ti->private;
uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT;
/*
* If the system-determined stacked limits are compatible with the
* cache's blocksize (io_opt is a factor) do not override them.
*/
if (io_opt_sectors < cache->sectors_per_block ||
do_div(io_opt_sectors, cache->sectors_per_block)) {
blk_limits_io_min(limits, cache->sectors_per_block << SECTOR_SHIFT);
blk_limits_io_opt(limits, cache->sectors_per_block << SECTOR_SHIFT);
}
disable_passdown_if_not_supported(cache);
set_discard_limits(cache, limits);
}
/*----------------------------------------------------------------*/
static struct target_type cache_target = {
.name = "cache",
.version = {2, 2, 0},
.module = THIS_MODULE,
.ctr = cache_ctr,
.dtr = cache_dtr,
.map = cache_map,
.end_io = cache_end_io,
.postsuspend = cache_postsuspend,
.preresume = cache_preresume,
.resume = cache_resume,
.status = cache_status,
.message = cache_message,
.iterate_devices = cache_iterate_devices,
.io_hints = cache_io_hints,
};
static int __init dm_cache_init(void)
{
int r;
migration_cache = KMEM_CACHE(dm_cache_migration, 0);
if (!migration_cache)
return -ENOMEM;
r = dm_register_target(&cache_target);
if (r) {
kmem_cache_destroy(migration_cache);
return r;
}
return 0;
}
static void __exit dm_cache_exit(void)
{
dm_unregister_target(&cache_target);
kmem_cache_destroy(migration_cache);
}
module_init(dm_cache_init);
module_exit(dm_cache_exit);
MODULE_DESCRIPTION(DM_NAME " cache target");
MODULE_AUTHOR("Joe Thornber <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-cache-target.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2017 The Chromium OS Authors <[email protected]>
*
* This file is released under the GPLv2.
*/
#include <linux/ctype.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/device-mapper.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/moduleparam.h>
#define DM_MSG_PREFIX "init"
#define DM_MAX_DEVICES 256
#define DM_MAX_TARGETS 256
#define DM_MAX_STR_SIZE 4096
#define DM_MAX_WAITFOR 256
static char *create;
static char *waitfor[DM_MAX_WAITFOR];
/*
* Format: dm-mod.create=<name>,<uuid>,<minor>,<flags>,<table>[,<table>+][;<name>,<uuid>,<minor>,<flags>,<table>[,<table>+]+]
* Table format: <start_sector> <num_sectors> <target_type> <target_args>
* Block devices to wait for to become available before setting up tables:
* dm-mod.waitfor=<device1>[,..,<deviceN>]
*
* See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..." format
* details.
*/
struct dm_device {
struct dm_ioctl dmi;
struct dm_target_spec *table[DM_MAX_TARGETS];
char *target_args_array[DM_MAX_TARGETS];
struct list_head list;
};
static const char * const dm_allowed_targets[] __initconst = {
"crypt",
"delay",
"linear",
"snapshot-origin",
"striped",
"verity",
};
static int __init dm_verify_target_type(const char *target)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(dm_allowed_targets); i++) {
if (!strcmp(dm_allowed_targets[i], target))
return 0;
}
return -EINVAL;
}
static void __init dm_setup_cleanup(struct list_head *devices)
{
struct dm_device *dev, *tmp;
unsigned int i;
list_for_each_entry_safe(dev, tmp, devices, list) {
list_del(&dev->list);
for (i = 0; i < dev->dmi.target_count; i++) {
kfree(dev->table[i]);
kfree(dev->target_args_array[i]);
}
kfree(dev);
}
}
/**
* str_field_delimit - delimit a string based on a separator char.
* @str: the pointer to the string to delimit.
* @separator: char that delimits the field
*
* Find a @separator and replace it by '\0'.
* Remove leading and trailing spaces.
* Return the remainder string after the @separator.
*/
static char __init *str_field_delimit(char **str, char separator)
{
char *s;
/* TODO: add support for escaped characters */
*str = skip_spaces(*str);
s = strchr(*str, separator);
/* Delimit the field and remove trailing spaces */
if (s)
*s = '\0';
*str = strim(*str);
return s ? ++s : NULL;
}
/**
* dm_parse_table_entry - parse a table entry
* @dev: device to store the parsed information.
* @str: the pointer to a string with the format:
* <start_sector> <num_sectors> <target_type> <target_args>[, ...]
*
* Return the remainder string after the table entry, i.e, after the comma which
* delimits the entry or NULL if reached the end of the string.
*/
static char __init *dm_parse_table_entry(struct dm_device *dev, char *str)
{
const unsigned int n = dev->dmi.target_count - 1;
struct dm_target_spec *sp;
unsigned int i;
/* fields: */
char *field[4];
char *next;
field[0] = str;
/* Delimit first 3 fields that are separated by space */
for (i = 0; i < ARRAY_SIZE(field) - 1; i++) {
field[i + 1] = str_field_delimit(&field[i], ' ');
if (!field[i + 1])
return ERR_PTR(-EINVAL);
}
/* Delimit last field that can be terminated by comma */
next = str_field_delimit(&field[i], ',');
sp = kzalloc(sizeof(*sp), GFP_KERNEL);
if (!sp)
return ERR_PTR(-ENOMEM);
dev->table[n] = sp;
/* start_sector */
if (kstrtoull(field[0], 0, &sp->sector_start))
return ERR_PTR(-EINVAL);
/* num_sector */
if (kstrtoull(field[1], 0, &sp->length))
return ERR_PTR(-EINVAL);
/* target_type */
strscpy(sp->target_type, field[2], sizeof(sp->target_type));
if (dm_verify_target_type(sp->target_type)) {
DMERR("invalid type \"%s\"", sp->target_type);
return ERR_PTR(-EINVAL);
}
/* target_args */
dev->target_args_array[n] = kstrndup(field[3], DM_MAX_STR_SIZE,
GFP_KERNEL);
if (!dev->target_args_array[n])
return ERR_PTR(-ENOMEM);
return next;
}
/**
* dm_parse_table - parse "dm-mod.create=" table field
* @dev: device to store the parsed information.
* @str: the pointer to a string with the format:
* <table>[,<table>+]
*/
static int __init dm_parse_table(struct dm_device *dev, char *str)
{
char *table_entry = str;
while (table_entry) {
DMDEBUG("parsing table \"%s\"", str);
if (++dev->dmi.target_count > DM_MAX_TARGETS) {
DMERR("too many targets %u > %d",
dev->dmi.target_count, DM_MAX_TARGETS);
return -EINVAL;
}
table_entry = dm_parse_table_entry(dev, table_entry);
if (IS_ERR(table_entry)) {
DMERR("couldn't parse table");
return PTR_ERR(table_entry);
}
}
return 0;
}
/**
* dm_parse_device_entry - parse a device entry
* @dev: device to store the parsed information.
* @str: the pointer to a string with the format:
* name,uuid,minor,flags,table[; ...]
*
* Return the remainder string after the table entry, i.e, after the semi-colon
* which delimits the entry or NULL if reached the end of the string.
*/
static char __init *dm_parse_device_entry(struct dm_device *dev, char *str)
{
/* There are 5 fields: name,uuid,minor,flags,table; */
char *field[5];
unsigned int i;
char *next;
field[0] = str;
/* Delimit first 4 fields that are separated by comma */
for (i = 0; i < ARRAY_SIZE(field) - 1; i++) {
field[i+1] = str_field_delimit(&field[i], ',');
if (!field[i+1])
return ERR_PTR(-EINVAL);
}
/* Delimit last field that can be delimited by semi-colon */
next = str_field_delimit(&field[i], ';');
/* name */
strscpy(dev->dmi.name, field[0], sizeof(dev->dmi.name));
/* uuid */
strscpy(dev->dmi.uuid, field[1], sizeof(dev->dmi.uuid));
/* minor */
if (strlen(field[2])) {
if (kstrtoull(field[2], 0, &dev->dmi.dev))
return ERR_PTR(-EINVAL);
dev->dmi.flags |= DM_PERSISTENT_DEV_FLAG;
}
/* flags */
if (!strcmp(field[3], "ro"))
dev->dmi.flags |= DM_READONLY_FLAG;
else if (strcmp(field[3], "rw"))
return ERR_PTR(-EINVAL);
/* table */
if (dm_parse_table(dev, field[4]))
return ERR_PTR(-EINVAL);
return next;
}
/**
* dm_parse_devices - parse "dm-mod.create=" argument
* @devices: list of struct dm_device to store the parsed information.
* @str: the pointer to a string with the format:
* <device>[;<device>+]
*/
static int __init dm_parse_devices(struct list_head *devices, char *str)
{
unsigned long ndev = 0;
struct dm_device *dev;
char *device = str;
DMDEBUG("parsing \"%s\"", str);
while (device) {
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return -ENOMEM;
list_add_tail(&dev->list, devices);
if (++ndev > DM_MAX_DEVICES) {
DMERR("too many devices %lu > %d",
ndev, DM_MAX_DEVICES);
return -EINVAL;
}
device = dm_parse_device_entry(dev, device);
if (IS_ERR(device)) {
DMERR("couldn't parse device");
return PTR_ERR(device);
}
}
return 0;
}
/**
* dm_init_init - parse "dm-mod.create=" argument and configure drivers
*/
static int __init dm_init_init(void)
{
struct dm_device *dev;
LIST_HEAD(devices);
char *str;
int i, r;
if (!create)
return 0;
if (strlen(create) >= DM_MAX_STR_SIZE) {
DMERR("Argument is too big. Limit is %d", DM_MAX_STR_SIZE);
return -EINVAL;
}
str = kstrndup(create, DM_MAX_STR_SIZE, GFP_KERNEL);
if (!str)
return -ENOMEM;
r = dm_parse_devices(&devices, str);
if (r)
goto out;
DMINFO("waiting for all devices to be available before creating mapped devices");
wait_for_device_probe();
for (i = 0; i < ARRAY_SIZE(waitfor); i++) {
if (waitfor[i]) {
dev_t dev;
DMINFO("waiting for device %s ...", waitfor[i]);
while (early_lookup_bdev(waitfor[i], &dev))
fsleep(5000);
}
}
if (waitfor[0])
DMINFO("all devices available");
list_for_each_entry(dev, &devices, list) {
if (dm_early_create(&dev->dmi, dev->table,
dev->target_args_array))
break;
}
out:
kfree(str);
dm_setup_cleanup(&devices);
return r;
}
late_initcall(dm_init_init);
module_param(create, charp, 0);
MODULE_PARM_DESC(create, "Create a mapped device in early boot");
module_param_array(waitfor, charp, NULL, 0);
MODULE_PARM_DESC(waitfor, "Devices to wait for before setting up tables");
| linux-master | drivers/md/dm-init.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2011-2012 Red Hat UK.
*
* This file is released under the GPL.
*/
#include "dm-thin-metadata.h"
#include "dm-bio-prison-v1.h"
#include "dm.h"
#include <linux/device-mapper.h>
#include <linux/dm-io.h>
#include <linux/dm-kcopyd.h>
#include <linux/jiffies.h>
#include <linux/log2.h>
#include <linux/list.h>
#include <linux/rculist.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/sort.h>
#include <linux/rbtree.h>
#define DM_MSG_PREFIX "thin"
/*
* Tunable constants
*/
#define ENDIO_HOOK_POOL_SIZE 1024
#define MAPPING_POOL_SIZE 1024
#define COMMIT_PERIOD HZ
#define NO_SPACE_TIMEOUT_SECS 60
static unsigned int no_space_timeout_secs = NO_SPACE_TIMEOUT_SECS;
DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(snapshot_copy_throttle,
"A percentage of time allocated for copy on write");
/*
* The block size of the device holding pool data must be
* between 64KB and 1GB.
*/
#define DATA_DEV_BLOCK_SIZE_MIN_SECTORS (64 * 1024 >> SECTOR_SHIFT)
#define DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT)
/*
* Device id is restricted to 24 bits.
*/
#define MAX_DEV_ID ((1 << 24) - 1)
/*
* How do we handle breaking sharing of data blocks?
* =================================================
*
* We use a standard copy-on-write btree to store the mappings for the
* devices (note I'm talking about copy-on-write of the metadata here, not
* the data). When you take an internal snapshot you clone the root node
* of the origin btree. After this there is no concept of an origin or a
* snapshot. They are just two device trees that happen to point to the
* same data blocks.
*
* When we get a write in we decide if it's to a shared data block using
* some timestamp magic. If it is, we have to break sharing.
*
* Let's say we write to a shared block in what was the origin. The
* steps are:
*
* i) plug io further to this physical block. (see bio_prison code).
*
* ii) quiesce any read io to that shared data block. Obviously
* including all devices that share this block. (see dm_deferred_set code)
*
* iii) copy the data block to a newly allocate block. This step can be
* missed out if the io covers the block. (schedule_copy).
*
* iv) insert the new mapping into the origin's btree
* (process_prepared_mapping). This act of inserting breaks some
* sharing of btree nodes between the two devices. Breaking sharing only
* effects the btree of that specific device. Btrees for the other
* devices that share the block never change. The btree for the origin
* device as it was after the last commit is untouched, ie. we're using
* persistent data structures in the functional programming sense.
*
* v) unplug io to this physical block, including the io that triggered
* the breaking of sharing.
*
* Steps (ii) and (iii) occur in parallel.
*
* The metadata _doesn't_ need to be committed before the io continues. We
* get away with this because the io is always written to a _new_ block.
* If there's a crash, then:
*
* - The origin mapping will point to the old origin block (the shared
* one). This will contain the data as it was before the io that triggered
* the breaking of sharing came in.
*
* - The snap mapping still points to the old block. As it would after
* the commit.
*
* The downside of this scheme is the timestamp magic isn't perfect, and
* will continue to think that data block in the snapshot device is shared
* even after the write to the origin has broken sharing. I suspect data
* blocks will typically be shared by many different devices, so we're
* breaking sharing n + 1 times, rather than n, where n is the number of
* devices that reference this data block. At the moment I think the
* benefits far, far outweigh the disadvantages.
*/
/*----------------------------------------------------------------*/
/*
* Key building.
*/
enum lock_space {
VIRTUAL,
PHYSICAL
};
static bool build_key(struct dm_thin_device *td, enum lock_space ls,
dm_block_t b, dm_block_t e, struct dm_cell_key *key)
{
key->virtual = (ls == VIRTUAL);
key->dev = dm_thin_dev_id(td);
key->block_begin = b;
key->block_end = e;
return dm_cell_key_has_valid_range(key);
}
static void build_data_key(struct dm_thin_device *td, dm_block_t b,
struct dm_cell_key *key)
{
(void) build_key(td, PHYSICAL, b, b + 1llu, key);
}
static void build_virtual_key(struct dm_thin_device *td, dm_block_t b,
struct dm_cell_key *key)
{
(void) build_key(td, VIRTUAL, b, b + 1llu, key);
}
/*----------------------------------------------------------------*/
#define THROTTLE_THRESHOLD (1 * HZ)
struct throttle {
struct rw_semaphore lock;
unsigned long threshold;
bool throttle_applied;
};
static void throttle_init(struct throttle *t)
{
init_rwsem(&t->lock);
t->throttle_applied = false;
}
static void throttle_work_start(struct throttle *t)
{
t->threshold = jiffies + THROTTLE_THRESHOLD;
}
static void throttle_work_update(struct throttle *t)
{
if (!t->throttle_applied && time_is_before_jiffies(t->threshold)) {
down_write(&t->lock);
t->throttle_applied = true;
}
}
static void throttle_work_complete(struct throttle *t)
{
if (t->throttle_applied) {
t->throttle_applied = false;
up_write(&t->lock);
}
}
static void throttle_lock(struct throttle *t)
{
down_read(&t->lock);
}
static void throttle_unlock(struct throttle *t)
{
up_read(&t->lock);
}
/*----------------------------------------------------------------*/
/*
* A pool device ties together a metadata device and a data device. It
* also provides the interface for creating and destroying internal
* devices.
*/
struct dm_thin_new_mapping;
/*
* The pool runs in various modes. Ordered in degraded order for comparisons.
*/
enum pool_mode {
PM_WRITE, /* metadata may be changed */
PM_OUT_OF_DATA_SPACE, /* metadata may be changed, though data may not be allocated */
/*
* Like READ_ONLY, except may switch back to WRITE on metadata resize. Reported as READ_ONLY.
*/
PM_OUT_OF_METADATA_SPACE,
PM_READ_ONLY, /* metadata may not be changed */
PM_FAIL, /* all I/O fails */
};
struct pool_features {
enum pool_mode mode;
bool zero_new_blocks:1;
bool discard_enabled:1;
bool discard_passdown:1;
bool error_if_no_space:1;
};
struct thin_c;
typedef void (*process_bio_fn)(struct thin_c *tc, struct bio *bio);
typedef void (*process_cell_fn)(struct thin_c *tc, struct dm_bio_prison_cell *cell);
typedef void (*process_mapping_fn)(struct dm_thin_new_mapping *m);
#define CELL_SORT_ARRAY_SIZE 8192
struct pool {
struct list_head list;
struct dm_target *ti; /* Only set if a pool target is bound */
struct mapped_device *pool_md;
struct block_device *data_dev;
struct block_device *md_dev;
struct dm_pool_metadata *pmd;
dm_block_t low_water_blocks;
uint32_t sectors_per_block;
int sectors_per_block_shift;
struct pool_features pf;
bool low_water_triggered:1; /* A dm event has been sent */
bool suspended:1;
bool out_of_data_space:1;
struct dm_bio_prison *prison;
struct dm_kcopyd_client *copier;
struct work_struct worker;
struct workqueue_struct *wq;
struct throttle throttle;
struct delayed_work waker;
struct delayed_work no_space_timeout;
unsigned long last_commit_jiffies;
unsigned int ref_count;
spinlock_t lock;
struct bio_list deferred_flush_bios;
struct bio_list deferred_flush_completions;
struct list_head prepared_mappings;
struct list_head prepared_discards;
struct list_head prepared_discards_pt2;
struct list_head active_thins;
struct dm_deferred_set *shared_read_ds;
struct dm_deferred_set *all_io_ds;
struct dm_thin_new_mapping *next_mapping;
process_bio_fn process_bio;
process_bio_fn process_discard;
process_cell_fn process_cell;
process_cell_fn process_discard_cell;
process_mapping_fn process_prepared_mapping;
process_mapping_fn process_prepared_discard;
process_mapping_fn process_prepared_discard_pt2;
struct dm_bio_prison_cell **cell_sort_array;
mempool_t mapping_pool;
};
static void metadata_operation_failed(struct pool *pool, const char *op, int r);
static enum pool_mode get_pool_mode(struct pool *pool)
{
return pool->pf.mode;
}
static void notify_of_pool_mode_change(struct pool *pool)
{
static const char *descs[] = {
"write",
"out-of-data-space",
"read-only",
"read-only",
"fail"
};
const char *extra_desc = NULL;
enum pool_mode mode = get_pool_mode(pool);
if (mode == PM_OUT_OF_DATA_SPACE) {
if (!pool->pf.error_if_no_space)
extra_desc = " (queue IO)";
else
extra_desc = " (error IO)";
}
dm_table_event(pool->ti->table);
DMINFO("%s: switching pool to %s%s mode",
dm_device_name(pool->pool_md),
descs[(int)mode], extra_desc ? : "");
}
/*
* Target context for a pool.
*/
struct pool_c {
struct dm_target *ti;
struct pool *pool;
struct dm_dev *data_dev;
struct dm_dev *metadata_dev;
dm_block_t low_water_blocks;
struct pool_features requested_pf; /* Features requested during table load */
struct pool_features adjusted_pf; /* Features used after adjusting for constituent devices */
};
/*
* Target context for a thin.
*/
struct thin_c {
struct list_head list;
struct dm_dev *pool_dev;
struct dm_dev *origin_dev;
sector_t origin_size;
dm_thin_id dev_id;
struct pool *pool;
struct dm_thin_device *td;
struct mapped_device *thin_md;
bool requeue_mode:1;
spinlock_t lock;
struct list_head deferred_cells;
struct bio_list deferred_bio_list;
struct bio_list retry_on_resume_list;
struct rb_root sort_bio_list; /* sorted list of deferred bios */
/*
* Ensures the thin is not destroyed until the worker has finished
* iterating the active_thins list.
*/
refcount_t refcount;
struct completion can_destroy;
};
/*----------------------------------------------------------------*/
static bool block_size_is_power_of_two(struct pool *pool)
{
return pool->sectors_per_block_shift >= 0;
}
static sector_t block_to_sectors(struct pool *pool, dm_block_t b)
{
return block_size_is_power_of_two(pool) ?
(b << pool->sectors_per_block_shift) :
(b * pool->sectors_per_block);
}
/*----------------------------------------------------------------*/
struct discard_op {
struct thin_c *tc;
struct blk_plug plug;
struct bio *parent_bio;
struct bio *bio;
};
static void begin_discard(struct discard_op *op, struct thin_c *tc, struct bio *parent)
{
BUG_ON(!parent);
op->tc = tc;
blk_start_plug(&op->plug);
op->parent_bio = parent;
op->bio = NULL;
}
static int issue_discard(struct discard_op *op, dm_block_t data_b, dm_block_t data_e)
{
struct thin_c *tc = op->tc;
sector_t s = block_to_sectors(tc->pool, data_b);
sector_t len = block_to_sectors(tc->pool, data_e - data_b);
return __blkdev_issue_discard(tc->pool_dev->bdev, s, len, GFP_NOIO, &op->bio);
}
static void end_discard(struct discard_op *op, int r)
{
if (op->bio) {
/*
* Even if one of the calls to issue_discard failed, we
* need to wait for the chain to complete.
*/
bio_chain(op->bio, op->parent_bio);
op->bio->bi_opf = REQ_OP_DISCARD;
submit_bio(op->bio);
}
blk_finish_plug(&op->plug);
/*
* Even if r is set, there could be sub discards in flight that we
* need to wait for.
*/
if (r && !op->parent_bio->bi_status)
op->parent_bio->bi_status = errno_to_blk_status(r);
bio_endio(op->parent_bio);
}
/*----------------------------------------------------------------*/
/*
* wake_worker() is used when new work is queued and when pool_resume is
* ready to continue deferred IO processing.
*/
static void wake_worker(struct pool *pool)
{
queue_work(pool->wq, &pool->worker);
}
/*----------------------------------------------------------------*/
static int bio_detain(struct pool *pool, struct dm_cell_key *key, struct bio *bio,
struct dm_bio_prison_cell **cell_result)
{
int r;
struct dm_bio_prison_cell *cell_prealloc;
/*
* Allocate a cell from the prison's mempool.
* This might block but it can't fail.
*/
cell_prealloc = dm_bio_prison_alloc_cell(pool->prison, GFP_NOIO);
r = dm_bio_detain(pool->prison, key, bio, cell_prealloc, cell_result);
if (r)
/*
* We reused an old cell; we can get rid of
* the new one.
*/
dm_bio_prison_free_cell(pool->prison, cell_prealloc);
return r;
}
static void cell_release(struct pool *pool,
struct dm_bio_prison_cell *cell,
struct bio_list *bios)
{
dm_cell_release(pool->prison, cell, bios);
dm_bio_prison_free_cell(pool->prison, cell);
}
static void cell_visit_release(struct pool *pool,
void (*fn)(void *, struct dm_bio_prison_cell *),
void *context,
struct dm_bio_prison_cell *cell)
{
dm_cell_visit_release(pool->prison, fn, context, cell);
dm_bio_prison_free_cell(pool->prison, cell);
}
static void cell_release_no_holder(struct pool *pool,
struct dm_bio_prison_cell *cell,
struct bio_list *bios)
{
dm_cell_release_no_holder(pool->prison, cell, bios);
dm_bio_prison_free_cell(pool->prison, cell);
}
static void cell_error_with_code(struct pool *pool,
struct dm_bio_prison_cell *cell, blk_status_t error_code)
{
dm_cell_error(pool->prison, cell, error_code);
dm_bio_prison_free_cell(pool->prison, cell);
}
static blk_status_t get_pool_io_error_code(struct pool *pool)
{
return pool->out_of_data_space ? BLK_STS_NOSPC : BLK_STS_IOERR;
}
static void cell_error(struct pool *pool, struct dm_bio_prison_cell *cell)
{
cell_error_with_code(pool, cell, get_pool_io_error_code(pool));
}
static void cell_success(struct pool *pool, struct dm_bio_prison_cell *cell)
{
cell_error_with_code(pool, cell, 0);
}
static void cell_requeue(struct pool *pool, struct dm_bio_prison_cell *cell)
{
cell_error_with_code(pool, cell, BLK_STS_DM_REQUEUE);
}
/*----------------------------------------------------------------*/
/*
* A global list of pools that uses a struct mapped_device as a key.
*/
static struct dm_thin_pool_table {
struct mutex mutex;
struct list_head pools;
} dm_thin_pool_table;
static void pool_table_init(void)
{
mutex_init(&dm_thin_pool_table.mutex);
INIT_LIST_HEAD(&dm_thin_pool_table.pools);
}
static void pool_table_exit(void)
{
mutex_destroy(&dm_thin_pool_table.mutex);
}
static void __pool_table_insert(struct pool *pool)
{
BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
list_add(&pool->list, &dm_thin_pool_table.pools);
}
static void __pool_table_remove(struct pool *pool)
{
BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
list_del(&pool->list);
}
static struct pool *__pool_table_lookup(struct mapped_device *md)
{
struct pool *pool = NULL, *tmp;
BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) {
if (tmp->pool_md == md) {
pool = tmp;
break;
}
}
return pool;
}
static struct pool *__pool_table_lookup_metadata_dev(struct block_device *md_dev)
{
struct pool *pool = NULL, *tmp;
BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
list_for_each_entry(tmp, &dm_thin_pool_table.pools, list) {
if (tmp->md_dev == md_dev) {
pool = tmp;
break;
}
}
return pool;
}
/*----------------------------------------------------------------*/
struct dm_thin_endio_hook {
struct thin_c *tc;
struct dm_deferred_entry *shared_read_entry;
struct dm_deferred_entry *all_io_entry;
struct dm_thin_new_mapping *overwrite_mapping;
struct rb_node rb_node;
struct dm_bio_prison_cell *cell;
};
static void __merge_bio_list(struct bio_list *bios, struct bio_list *master)
{
bio_list_merge(bios, master);
bio_list_init(master);
}
static void error_bio_list(struct bio_list *bios, blk_status_t error)
{
struct bio *bio;
while ((bio = bio_list_pop(bios))) {
bio->bi_status = error;
bio_endio(bio);
}
}
static void error_thin_bio_list(struct thin_c *tc, struct bio_list *master,
blk_status_t error)
{
struct bio_list bios;
bio_list_init(&bios);
spin_lock_irq(&tc->lock);
__merge_bio_list(&bios, master);
spin_unlock_irq(&tc->lock);
error_bio_list(&bios, error);
}
static void requeue_deferred_cells(struct thin_c *tc)
{
struct pool *pool = tc->pool;
struct list_head cells;
struct dm_bio_prison_cell *cell, *tmp;
INIT_LIST_HEAD(&cells);
spin_lock_irq(&tc->lock);
list_splice_init(&tc->deferred_cells, &cells);
spin_unlock_irq(&tc->lock);
list_for_each_entry_safe(cell, tmp, &cells, user_list)
cell_requeue(pool, cell);
}
static void requeue_io(struct thin_c *tc)
{
struct bio_list bios;
bio_list_init(&bios);
spin_lock_irq(&tc->lock);
__merge_bio_list(&bios, &tc->deferred_bio_list);
__merge_bio_list(&bios, &tc->retry_on_resume_list);
spin_unlock_irq(&tc->lock);
error_bio_list(&bios, BLK_STS_DM_REQUEUE);
requeue_deferred_cells(tc);
}
static void error_retry_list_with_code(struct pool *pool, blk_status_t error)
{
struct thin_c *tc;
rcu_read_lock();
list_for_each_entry_rcu(tc, &pool->active_thins, list)
error_thin_bio_list(tc, &tc->retry_on_resume_list, error);
rcu_read_unlock();
}
static void error_retry_list(struct pool *pool)
{
error_retry_list_with_code(pool, get_pool_io_error_code(pool));
}
/*
* This section of code contains the logic for processing a thin device's IO.
* Much of the code depends on pool object resources (lists, workqueues, etc)
* but most is exclusively called from the thin target rather than the thin-pool
* target.
*/
static dm_block_t get_bio_block(struct thin_c *tc, struct bio *bio)
{
struct pool *pool = tc->pool;
sector_t block_nr = bio->bi_iter.bi_sector;
if (block_size_is_power_of_two(pool))
block_nr >>= pool->sectors_per_block_shift;
else
(void) sector_div(block_nr, pool->sectors_per_block);
return block_nr;
}
/*
* Returns the _complete_ blocks that this bio covers.
*/
static void get_bio_block_range(struct thin_c *tc, struct bio *bio,
dm_block_t *begin, dm_block_t *end)
{
struct pool *pool = tc->pool;
sector_t b = bio->bi_iter.bi_sector;
sector_t e = b + (bio->bi_iter.bi_size >> SECTOR_SHIFT);
b += pool->sectors_per_block - 1ull; /* so we round up */
if (block_size_is_power_of_two(pool)) {
b >>= pool->sectors_per_block_shift;
e >>= pool->sectors_per_block_shift;
} else {
(void) sector_div(b, pool->sectors_per_block);
(void) sector_div(e, pool->sectors_per_block);
}
if (e < b)
/* Can happen if the bio is within a single block. */
e = b;
*begin = b;
*end = e;
}
static void remap(struct thin_c *tc, struct bio *bio, dm_block_t block)
{
struct pool *pool = tc->pool;
sector_t bi_sector = bio->bi_iter.bi_sector;
bio_set_dev(bio, tc->pool_dev->bdev);
if (block_size_is_power_of_two(pool))
bio->bi_iter.bi_sector =
(block << pool->sectors_per_block_shift) |
(bi_sector & (pool->sectors_per_block - 1));
else
bio->bi_iter.bi_sector = (block * pool->sectors_per_block) +
sector_div(bi_sector, pool->sectors_per_block);
}
static void remap_to_origin(struct thin_c *tc, struct bio *bio)
{
bio_set_dev(bio, tc->origin_dev->bdev);
}
static int bio_triggers_commit(struct thin_c *tc, struct bio *bio)
{
return op_is_flush(bio->bi_opf) &&
dm_thin_changed_this_transaction(tc->td);
}
static void inc_all_io_entry(struct pool *pool, struct bio *bio)
{
struct dm_thin_endio_hook *h;
if (bio_op(bio) == REQ_OP_DISCARD)
return;
h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
h->all_io_entry = dm_deferred_entry_inc(pool->all_io_ds);
}
static void issue(struct thin_c *tc, struct bio *bio)
{
struct pool *pool = tc->pool;
if (!bio_triggers_commit(tc, bio)) {
dm_submit_bio_remap(bio, NULL);
return;
}
/*
* Complete bio with an error if earlier I/O caused changes to
* the metadata that can't be committed e.g, due to I/O errors
* on the metadata device.
*/
if (dm_thin_aborted_changes(tc->td)) {
bio_io_error(bio);
return;
}
/*
* Batch together any bios that trigger commits and then issue a
* single commit for them in process_deferred_bios().
*/
spin_lock_irq(&pool->lock);
bio_list_add(&pool->deferred_flush_bios, bio);
spin_unlock_irq(&pool->lock);
}
static void remap_to_origin_and_issue(struct thin_c *tc, struct bio *bio)
{
remap_to_origin(tc, bio);
issue(tc, bio);
}
static void remap_and_issue(struct thin_c *tc, struct bio *bio,
dm_block_t block)
{
remap(tc, bio, block);
issue(tc, bio);
}
/*----------------------------------------------------------------*/
/*
* Bio endio functions.
*/
struct dm_thin_new_mapping {
struct list_head list;
bool pass_discard:1;
bool maybe_shared:1;
/*
* Track quiescing, copying and zeroing preparation actions. When this
* counter hits zero the block is prepared and can be inserted into the
* btree.
*/
atomic_t prepare_actions;
blk_status_t status;
struct thin_c *tc;
dm_block_t virt_begin, virt_end;
dm_block_t data_block;
struct dm_bio_prison_cell *cell;
/*
* If the bio covers the whole area of a block then we can avoid
* zeroing or copying. Instead this bio is hooked. The bio will
* still be in the cell, so care has to be taken to avoid issuing
* the bio twice.
*/
struct bio *bio;
bio_end_io_t *saved_bi_end_io;
};
static void __complete_mapping_preparation(struct dm_thin_new_mapping *m)
{
struct pool *pool = m->tc->pool;
if (atomic_dec_and_test(&m->prepare_actions)) {
list_add_tail(&m->list, &pool->prepared_mappings);
wake_worker(pool);
}
}
static void complete_mapping_preparation(struct dm_thin_new_mapping *m)
{
unsigned long flags;
struct pool *pool = m->tc->pool;
spin_lock_irqsave(&pool->lock, flags);
__complete_mapping_preparation(m);
spin_unlock_irqrestore(&pool->lock, flags);
}
static void copy_complete(int read_err, unsigned long write_err, void *context)
{
struct dm_thin_new_mapping *m = context;
m->status = read_err || write_err ? BLK_STS_IOERR : 0;
complete_mapping_preparation(m);
}
static void overwrite_endio(struct bio *bio)
{
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
struct dm_thin_new_mapping *m = h->overwrite_mapping;
bio->bi_end_io = m->saved_bi_end_io;
m->status = bio->bi_status;
complete_mapping_preparation(m);
}
/*----------------------------------------------------------------*/
/*
* Workqueue.
*/
/*
* Prepared mapping jobs.
*/
/*
* This sends the bios in the cell, except the original holder, back
* to the deferred_bios list.
*/
static void cell_defer_no_holder(struct thin_c *tc, struct dm_bio_prison_cell *cell)
{
struct pool *pool = tc->pool;
unsigned long flags;
struct bio_list bios;
bio_list_init(&bios);
cell_release_no_holder(pool, cell, &bios);
if (!bio_list_empty(&bios)) {
spin_lock_irqsave(&tc->lock, flags);
bio_list_merge(&tc->deferred_bio_list, &bios);
spin_unlock_irqrestore(&tc->lock, flags);
wake_worker(pool);
}
}
static void thin_defer_bio(struct thin_c *tc, struct bio *bio);
struct remap_info {
struct thin_c *tc;
struct bio_list defer_bios;
struct bio_list issue_bios;
};
static void __inc_remap_and_issue_cell(void *context,
struct dm_bio_prison_cell *cell)
{
struct remap_info *info = context;
struct bio *bio;
while ((bio = bio_list_pop(&cell->bios))) {
if (op_is_flush(bio->bi_opf) || bio_op(bio) == REQ_OP_DISCARD)
bio_list_add(&info->defer_bios, bio);
else {
inc_all_io_entry(info->tc->pool, bio);
/*
* We can't issue the bios with the bio prison lock
* held, so we add them to a list to issue on
* return from this function.
*/
bio_list_add(&info->issue_bios, bio);
}
}
}
static void inc_remap_and_issue_cell(struct thin_c *tc,
struct dm_bio_prison_cell *cell,
dm_block_t block)
{
struct bio *bio;
struct remap_info info;
info.tc = tc;
bio_list_init(&info.defer_bios);
bio_list_init(&info.issue_bios);
/*
* We have to be careful to inc any bios we're about to issue
* before the cell is released, and avoid a race with new bios
* being added to the cell.
*/
cell_visit_release(tc->pool, __inc_remap_and_issue_cell,
&info, cell);
while ((bio = bio_list_pop(&info.defer_bios)))
thin_defer_bio(tc, bio);
while ((bio = bio_list_pop(&info.issue_bios)))
remap_and_issue(info.tc, bio, block);
}
static void process_prepared_mapping_fail(struct dm_thin_new_mapping *m)
{
cell_error(m->tc->pool, m->cell);
list_del(&m->list);
mempool_free(m, &m->tc->pool->mapping_pool);
}
static void complete_overwrite_bio(struct thin_c *tc, struct bio *bio)
{
struct pool *pool = tc->pool;
/*
* If the bio has the REQ_FUA flag set we must commit the metadata
* before signaling its completion.
*/
if (!bio_triggers_commit(tc, bio)) {
bio_endio(bio);
return;
}
/*
* Complete bio with an error if earlier I/O caused changes to the
* metadata that can't be committed, e.g, due to I/O errors on the
* metadata device.
*/
if (dm_thin_aborted_changes(tc->td)) {
bio_io_error(bio);
return;
}
/*
* Batch together any bios that trigger commits and then issue a
* single commit for them in process_deferred_bios().
*/
spin_lock_irq(&pool->lock);
bio_list_add(&pool->deferred_flush_completions, bio);
spin_unlock_irq(&pool->lock);
}
static void process_prepared_mapping(struct dm_thin_new_mapping *m)
{
struct thin_c *tc = m->tc;
struct pool *pool = tc->pool;
struct bio *bio = m->bio;
int r;
if (m->status) {
cell_error(pool, m->cell);
goto out;
}
/*
* Commit the prepared block into the mapping btree.
* Any I/O for this block arriving after this point will get
* remapped to it directly.
*/
r = dm_thin_insert_block(tc->td, m->virt_begin, m->data_block);
if (r) {
metadata_operation_failed(pool, "dm_thin_insert_block", r);
cell_error(pool, m->cell);
goto out;
}
/*
* Release any bios held while the block was being provisioned.
* If we are processing a write bio that completely covers the block,
* we already processed it so can ignore it now when processing
* the bios in the cell.
*/
if (bio) {
inc_remap_and_issue_cell(tc, m->cell, m->data_block);
complete_overwrite_bio(tc, bio);
} else {
inc_all_io_entry(tc->pool, m->cell->holder);
remap_and_issue(tc, m->cell->holder, m->data_block);
inc_remap_and_issue_cell(tc, m->cell, m->data_block);
}
out:
list_del(&m->list);
mempool_free(m, &pool->mapping_pool);
}
/*----------------------------------------------------------------*/
static void free_discard_mapping(struct dm_thin_new_mapping *m)
{
struct thin_c *tc = m->tc;
if (m->cell)
cell_defer_no_holder(tc, m->cell);
mempool_free(m, &tc->pool->mapping_pool);
}
static void process_prepared_discard_fail(struct dm_thin_new_mapping *m)
{
bio_io_error(m->bio);
free_discard_mapping(m);
}
static void process_prepared_discard_success(struct dm_thin_new_mapping *m)
{
bio_endio(m->bio);
free_discard_mapping(m);
}
static void process_prepared_discard_no_passdown(struct dm_thin_new_mapping *m)
{
int r;
struct thin_c *tc = m->tc;
r = dm_thin_remove_range(tc->td, m->cell->key.block_begin, m->cell->key.block_end);
if (r) {
metadata_operation_failed(tc->pool, "dm_thin_remove_range", r);
bio_io_error(m->bio);
} else
bio_endio(m->bio);
cell_defer_no_holder(tc, m->cell);
mempool_free(m, &tc->pool->mapping_pool);
}
/*----------------------------------------------------------------*/
static void passdown_double_checking_shared_status(struct dm_thin_new_mapping *m,
struct bio *discard_parent)
{
/*
* We've already unmapped this range of blocks, but before we
* passdown we have to check that these blocks are now unused.
*/
int r = 0;
bool shared = true;
struct thin_c *tc = m->tc;
struct pool *pool = tc->pool;
dm_block_t b = m->data_block, e, end = m->data_block + m->virt_end - m->virt_begin;
struct discard_op op;
begin_discard(&op, tc, discard_parent);
while (b != end) {
/* find start of unmapped run */
for (; b < end; b++) {
r = dm_pool_block_is_shared(pool->pmd, b, &shared);
if (r)
goto out;
if (!shared)
break;
}
if (b == end)
break;
/* find end of run */
for (e = b + 1; e != end; e++) {
r = dm_pool_block_is_shared(pool->pmd, e, &shared);
if (r)
goto out;
if (shared)
break;
}
r = issue_discard(&op, b, e);
if (r)
goto out;
b = e;
}
out:
end_discard(&op, r);
}
static void queue_passdown_pt2(struct dm_thin_new_mapping *m)
{
unsigned long flags;
struct pool *pool = m->tc->pool;
spin_lock_irqsave(&pool->lock, flags);
list_add_tail(&m->list, &pool->prepared_discards_pt2);
spin_unlock_irqrestore(&pool->lock, flags);
wake_worker(pool);
}
static void passdown_endio(struct bio *bio)
{
/*
* It doesn't matter if the passdown discard failed, we still want
* to unmap (we ignore err).
*/
queue_passdown_pt2(bio->bi_private);
bio_put(bio);
}
static void process_prepared_discard_passdown_pt1(struct dm_thin_new_mapping *m)
{
int r;
struct thin_c *tc = m->tc;
struct pool *pool = tc->pool;
struct bio *discard_parent;
dm_block_t data_end = m->data_block + (m->virt_end - m->virt_begin);
/*
* Only this thread allocates blocks, so we can be sure that the
* newly unmapped blocks will not be allocated before the end of
* the function.
*/
r = dm_thin_remove_range(tc->td, m->virt_begin, m->virt_end);
if (r) {
metadata_operation_failed(pool, "dm_thin_remove_range", r);
bio_io_error(m->bio);
cell_defer_no_holder(tc, m->cell);
mempool_free(m, &pool->mapping_pool);
return;
}
/*
* Increment the unmapped blocks. This prevents a race between the
* passdown io and reallocation of freed blocks.
*/
r = dm_pool_inc_data_range(pool->pmd, m->data_block, data_end);
if (r) {
metadata_operation_failed(pool, "dm_pool_inc_data_range", r);
bio_io_error(m->bio);
cell_defer_no_holder(tc, m->cell);
mempool_free(m, &pool->mapping_pool);
return;
}
discard_parent = bio_alloc(NULL, 1, 0, GFP_NOIO);
discard_parent->bi_end_io = passdown_endio;
discard_parent->bi_private = m;
if (m->maybe_shared)
passdown_double_checking_shared_status(m, discard_parent);
else {
struct discard_op op;
begin_discard(&op, tc, discard_parent);
r = issue_discard(&op, m->data_block, data_end);
end_discard(&op, r);
}
}
static void process_prepared_discard_passdown_pt2(struct dm_thin_new_mapping *m)
{
int r;
struct thin_c *tc = m->tc;
struct pool *pool = tc->pool;
/*
* The passdown has completed, so now we can decrement all those
* unmapped blocks.
*/
r = dm_pool_dec_data_range(pool->pmd, m->data_block,
m->data_block + (m->virt_end - m->virt_begin));
if (r) {
metadata_operation_failed(pool, "dm_pool_dec_data_range", r);
bio_io_error(m->bio);
} else
bio_endio(m->bio);
cell_defer_no_holder(tc, m->cell);
mempool_free(m, &pool->mapping_pool);
}
static void process_prepared(struct pool *pool, struct list_head *head,
process_mapping_fn *fn)
{
struct list_head maps;
struct dm_thin_new_mapping *m, *tmp;
INIT_LIST_HEAD(&maps);
spin_lock_irq(&pool->lock);
list_splice_init(head, &maps);
spin_unlock_irq(&pool->lock);
list_for_each_entry_safe(m, tmp, &maps, list)
(*fn)(m);
}
/*
* Deferred bio jobs.
*/
static int io_overlaps_block(struct pool *pool, struct bio *bio)
{
return bio->bi_iter.bi_size ==
(pool->sectors_per_block << SECTOR_SHIFT);
}
static int io_overwrites_block(struct pool *pool, struct bio *bio)
{
return (bio_data_dir(bio) == WRITE) &&
io_overlaps_block(pool, bio);
}
static void save_and_set_endio(struct bio *bio, bio_end_io_t **save,
bio_end_io_t *fn)
{
*save = bio->bi_end_io;
bio->bi_end_io = fn;
}
static int ensure_next_mapping(struct pool *pool)
{
if (pool->next_mapping)
return 0;
pool->next_mapping = mempool_alloc(&pool->mapping_pool, GFP_ATOMIC);
return pool->next_mapping ? 0 : -ENOMEM;
}
static struct dm_thin_new_mapping *get_next_mapping(struct pool *pool)
{
struct dm_thin_new_mapping *m = pool->next_mapping;
BUG_ON(!pool->next_mapping);
memset(m, 0, sizeof(struct dm_thin_new_mapping));
INIT_LIST_HEAD(&m->list);
m->bio = NULL;
pool->next_mapping = NULL;
return m;
}
static void ll_zero(struct thin_c *tc, struct dm_thin_new_mapping *m,
sector_t begin, sector_t end)
{
struct dm_io_region to;
to.bdev = tc->pool_dev->bdev;
to.sector = begin;
to.count = end - begin;
dm_kcopyd_zero(tc->pool->copier, 1, &to, 0, copy_complete, m);
}
static void remap_and_issue_overwrite(struct thin_c *tc, struct bio *bio,
dm_block_t data_begin,
struct dm_thin_new_mapping *m)
{
struct pool *pool = tc->pool;
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
h->overwrite_mapping = m;
m->bio = bio;
save_and_set_endio(bio, &m->saved_bi_end_io, overwrite_endio);
inc_all_io_entry(pool, bio);
remap_and_issue(tc, bio, data_begin);
}
/*
* A partial copy also needs to zero the uncopied region.
*/
static void schedule_copy(struct thin_c *tc, dm_block_t virt_block,
struct dm_dev *origin, dm_block_t data_origin,
dm_block_t data_dest,
struct dm_bio_prison_cell *cell, struct bio *bio,
sector_t len)
{
struct pool *pool = tc->pool;
struct dm_thin_new_mapping *m = get_next_mapping(pool);
m->tc = tc;
m->virt_begin = virt_block;
m->virt_end = virt_block + 1u;
m->data_block = data_dest;
m->cell = cell;
/*
* quiesce action + copy action + an extra reference held for the
* duration of this function (we may need to inc later for a
* partial zero).
*/
atomic_set(&m->prepare_actions, 3);
if (!dm_deferred_set_add_work(pool->shared_read_ds, &m->list))
complete_mapping_preparation(m); /* already quiesced */
/*
* IO to pool_dev remaps to the pool target's data_dev.
*
* If the whole block of data is being overwritten, we can issue the
* bio immediately. Otherwise we use kcopyd to clone the data first.
*/
if (io_overwrites_block(pool, bio))
remap_and_issue_overwrite(tc, bio, data_dest, m);
else {
struct dm_io_region from, to;
from.bdev = origin->bdev;
from.sector = data_origin * pool->sectors_per_block;
from.count = len;
to.bdev = tc->pool_dev->bdev;
to.sector = data_dest * pool->sectors_per_block;
to.count = len;
dm_kcopyd_copy(pool->copier, &from, 1, &to,
0, copy_complete, m);
/*
* Do we need to zero a tail region?
*/
if (len < pool->sectors_per_block && pool->pf.zero_new_blocks) {
atomic_inc(&m->prepare_actions);
ll_zero(tc, m,
data_dest * pool->sectors_per_block + len,
(data_dest + 1) * pool->sectors_per_block);
}
}
complete_mapping_preparation(m); /* drop our ref */
}
static void schedule_internal_copy(struct thin_c *tc, dm_block_t virt_block,
dm_block_t data_origin, dm_block_t data_dest,
struct dm_bio_prison_cell *cell, struct bio *bio)
{
schedule_copy(tc, virt_block, tc->pool_dev,
data_origin, data_dest, cell, bio,
tc->pool->sectors_per_block);
}
static void schedule_zero(struct thin_c *tc, dm_block_t virt_block,
dm_block_t data_block, struct dm_bio_prison_cell *cell,
struct bio *bio)
{
struct pool *pool = tc->pool;
struct dm_thin_new_mapping *m = get_next_mapping(pool);
atomic_set(&m->prepare_actions, 1); /* no need to quiesce */
m->tc = tc;
m->virt_begin = virt_block;
m->virt_end = virt_block + 1u;
m->data_block = data_block;
m->cell = cell;
/*
* If the whole block of data is being overwritten or we are not
* zeroing pre-existing data, we can issue the bio immediately.
* Otherwise we use kcopyd to zero the data first.
*/
if (pool->pf.zero_new_blocks) {
if (io_overwrites_block(pool, bio))
remap_and_issue_overwrite(tc, bio, data_block, m);
else
ll_zero(tc, m, data_block * pool->sectors_per_block,
(data_block + 1) * pool->sectors_per_block);
} else
process_prepared_mapping(m);
}
static void schedule_external_copy(struct thin_c *tc, dm_block_t virt_block,
dm_block_t data_dest,
struct dm_bio_prison_cell *cell, struct bio *bio)
{
struct pool *pool = tc->pool;
sector_t virt_block_begin = virt_block * pool->sectors_per_block;
sector_t virt_block_end = (virt_block + 1) * pool->sectors_per_block;
if (virt_block_end <= tc->origin_size)
schedule_copy(tc, virt_block, tc->origin_dev,
virt_block, data_dest, cell, bio,
pool->sectors_per_block);
else if (virt_block_begin < tc->origin_size)
schedule_copy(tc, virt_block, tc->origin_dev,
virt_block, data_dest, cell, bio,
tc->origin_size - virt_block_begin);
else
schedule_zero(tc, virt_block, data_dest, cell, bio);
}
static void set_pool_mode(struct pool *pool, enum pool_mode new_mode);
static void requeue_bios(struct pool *pool);
static bool is_read_only_pool_mode(enum pool_mode mode)
{
return (mode == PM_OUT_OF_METADATA_SPACE || mode == PM_READ_ONLY);
}
static bool is_read_only(struct pool *pool)
{
return is_read_only_pool_mode(get_pool_mode(pool));
}
static void check_for_metadata_space(struct pool *pool)
{
int r;
const char *ooms_reason = NULL;
dm_block_t nr_free;
r = dm_pool_get_free_metadata_block_count(pool->pmd, &nr_free);
if (r)
ooms_reason = "Could not get free metadata blocks";
else if (!nr_free)
ooms_reason = "No free metadata blocks";
if (ooms_reason && !is_read_only(pool)) {
DMERR("%s", ooms_reason);
set_pool_mode(pool, PM_OUT_OF_METADATA_SPACE);
}
}
static void check_for_data_space(struct pool *pool)
{
int r;
dm_block_t nr_free;
if (get_pool_mode(pool) != PM_OUT_OF_DATA_SPACE)
return;
r = dm_pool_get_free_block_count(pool->pmd, &nr_free);
if (r)
return;
if (nr_free) {
set_pool_mode(pool, PM_WRITE);
requeue_bios(pool);
}
}
/*
* A non-zero return indicates read_only or fail_io mode.
* Many callers don't care about the return value.
*/
static int commit(struct pool *pool)
{
int r;
if (get_pool_mode(pool) >= PM_OUT_OF_METADATA_SPACE)
return -EINVAL;
r = dm_pool_commit_metadata(pool->pmd);
if (r)
metadata_operation_failed(pool, "dm_pool_commit_metadata", r);
else {
check_for_metadata_space(pool);
check_for_data_space(pool);
}
return r;
}
static void check_low_water_mark(struct pool *pool, dm_block_t free_blocks)
{
if (free_blocks <= pool->low_water_blocks && !pool->low_water_triggered) {
DMWARN("%s: reached low water mark for data device: sending event.",
dm_device_name(pool->pool_md));
spin_lock_irq(&pool->lock);
pool->low_water_triggered = true;
spin_unlock_irq(&pool->lock);
dm_table_event(pool->ti->table);
}
}
static int alloc_data_block(struct thin_c *tc, dm_block_t *result)
{
int r;
dm_block_t free_blocks;
struct pool *pool = tc->pool;
if (WARN_ON(get_pool_mode(pool) != PM_WRITE))
return -EINVAL;
r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
if (r) {
metadata_operation_failed(pool, "dm_pool_get_free_block_count", r);
return r;
}
check_low_water_mark(pool, free_blocks);
if (!free_blocks) {
/*
* Try to commit to see if that will free up some
* more space.
*/
r = commit(pool);
if (r)
return r;
r = dm_pool_get_free_block_count(pool->pmd, &free_blocks);
if (r) {
metadata_operation_failed(pool, "dm_pool_get_free_block_count", r);
return r;
}
if (!free_blocks) {
set_pool_mode(pool, PM_OUT_OF_DATA_SPACE);
return -ENOSPC;
}
}
r = dm_pool_alloc_data_block(pool->pmd, result);
if (r) {
if (r == -ENOSPC)
set_pool_mode(pool, PM_OUT_OF_DATA_SPACE);
else
metadata_operation_failed(pool, "dm_pool_alloc_data_block", r);
return r;
}
r = dm_pool_get_free_metadata_block_count(pool->pmd, &free_blocks);
if (r) {
metadata_operation_failed(pool, "dm_pool_get_free_metadata_block_count", r);
return r;
}
if (!free_blocks) {
/* Let's commit before we use up the metadata reserve. */
r = commit(pool);
if (r)
return r;
}
return 0;
}
/*
* If we have run out of space, queue bios until the device is
* resumed, presumably after having been reloaded with more space.
*/
static void retry_on_resume(struct bio *bio)
{
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
struct thin_c *tc = h->tc;
spin_lock_irq(&tc->lock);
bio_list_add(&tc->retry_on_resume_list, bio);
spin_unlock_irq(&tc->lock);
}
static blk_status_t should_error_unserviceable_bio(struct pool *pool)
{
enum pool_mode m = get_pool_mode(pool);
switch (m) {
case PM_WRITE:
/* Shouldn't get here */
DMERR_LIMIT("bio unserviceable, yet pool is in PM_WRITE mode");
return BLK_STS_IOERR;
case PM_OUT_OF_DATA_SPACE:
return pool->pf.error_if_no_space ? BLK_STS_NOSPC : 0;
case PM_OUT_OF_METADATA_SPACE:
case PM_READ_ONLY:
case PM_FAIL:
return BLK_STS_IOERR;
default:
/* Shouldn't get here */
DMERR_LIMIT("bio unserviceable, yet pool has an unknown mode");
return BLK_STS_IOERR;
}
}
static void handle_unserviceable_bio(struct pool *pool, struct bio *bio)
{
blk_status_t error = should_error_unserviceable_bio(pool);
if (error) {
bio->bi_status = error;
bio_endio(bio);
} else
retry_on_resume(bio);
}
static void retry_bios_on_resume(struct pool *pool, struct dm_bio_prison_cell *cell)
{
struct bio *bio;
struct bio_list bios;
blk_status_t error;
error = should_error_unserviceable_bio(pool);
if (error) {
cell_error_with_code(pool, cell, error);
return;
}
bio_list_init(&bios);
cell_release(pool, cell, &bios);
while ((bio = bio_list_pop(&bios)))
retry_on_resume(bio);
}
static void process_discard_cell_no_passdown(struct thin_c *tc,
struct dm_bio_prison_cell *virt_cell)
{
struct pool *pool = tc->pool;
struct dm_thin_new_mapping *m = get_next_mapping(pool);
/*
* We don't need to lock the data blocks, since there's no
* passdown. We only lock data blocks for allocation and breaking sharing.
*/
m->tc = tc;
m->virt_begin = virt_cell->key.block_begin;
m->virt_end = virt_cell->key.block_end;
m->cell = virt_cell;
m->bio = virt_cell->holder;
if (!dm_deferred_set_add_work(pool->all_io_ds, &m->list))
pool->process_prepared_discard(m);
}
static void break_up_discard_bio(struct thin_c *tc, dm_block_t begin, dm_block_t end,
struct bio *bio)
{
struct pool *pool = tc->pool;
int r;
bool maybe_shared;
struct dm_cell_key data_key;
struct dm_bio_prison_cell *data_cell;
struct dm_thin_new_mapping *m;
dm_block_t virt_begin, virt_end, data_begin, data_end;
dm_block_t len, next_boundary;
while (begin != end) {
r = dm_thin_find_mapped_range(tc->td, begin, end, &virt_begin, &virt_end,
&data_begin, &maybe_shared);
if (r) {
/*
* Silently fail, letting any mappings we've
* created complete.
*/
break;
}
data_end = data_begin + (virt_end - virt_begin);
/*
* Make sure the data region obeys the bio prison restrictions.
*/
while (data_begin < data_end) {
r = ensure_next_mapping(pool);
if (r)
return; /* we did our best */
next_boundary = ((data_begin >> BIO_PRISON_MAX_RANGE_SHIFT) + 1)
<< BIO_PRISON_MAX_RANGE_SHIFT;
len = min_t(sector_t, data_end - data_begin, next_boundary - data_begin);
/* This key is certainly within range given the above splitting */
(void) build_key(tc->td, PHYSICAL, data_begin, data_begin + len, &data_key);
if (bio_detain(tc->pool, &data_key, NULL, &data_cell)) {
/* contention, we'll give up with this range */
data_begin += len;
continue;
}
/*
* IO may still be going to the destination block. We must
* quiesce before we can do the removal.
*/
m = get_next_mapping(pool);
m->tc = tc;
m->maybe_shared = maybe_shared;
m->virt_begin = virt_begin;
m->virt_end = virt_begin + len;
m->data_block = data_begin;
m->cell = data_cell;
m->bio = bio;
/*
* The parent bio must not complete before sub discard bios are
* chained to it (see end_discard's bio_chain)!
*
* This per-mapping bi_remaining increment is paired with
* the implicit decrement that occurs via bio_endio() in
* end_discard().
*/
bio_inc_remaining(bio);
if (!dm_deferred_set_add_work(pool->all_io_ds, &m->list))
pool->process_prepared_discard(m);
virt_begin += len;
data_begin += len;
}
begin = virt_end;
}
}
static void process_discard_cell_passdown(struct thin_c *tc, struct dm_bio_prison_cell *virt_cell)
{
struct bio *bio = virt_cell->holder;
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
/*
* The virt_cell will only get freed once the origin bio completes.
* This means it will remain locked while all the individual
* passdown bios are in flight.
*/
h->cell = virt_cell;
break_up_discard_bio(tc, virt_cell->key.block_begin, virt_cell->key.block_end, bio);
/*
* We complete the bio now, knowing that the bi_remaining field
* will prevent completion until the sub range discards have
* completed.
*/
bio_endio(bio);
}
static void process_discard_bio(struct thin_c *tc, struct bio *bio)
{
dm_block_t begin, end;
struct dm_cell_key virt_key;
struct dm_bio_prison_cell *virt_cell;
get_bio_block_range(tc, bio, &begin, &end);
if (begin == end) {
/*
* The discard covers less than a block.
*/
bio_endio(bio);
return;
}
if (unlikely(!build_key(tc->td, VIRTUAL, begin, end, &virt_key))) {
DMERR_LIMIT("Discard doesn't respect bio prison limits");
bio_endio(bio);
return;
}
if (bio_detain(tc->pool, &virt_key, bio, &virt_cell)) {
/*
* Potential starvation issue: We're relying on the
* fs/application being well behaved, and not trying to
* send IO to a region at the same time as discarding it.
* If they do this persistently then it's possible this
* cell will never be granted.
*/
return;
}
tc->pool->process_discard_cell(tc, virt_cell);
}
static void break_sharing(struct thin_c *tc, struct bio *bio, dm_block_t block,
struct dm_cell_key *key,
struct dm_thin_lookup_result *lookup_result,
struct dm_bio_prison_cell *cell)
{
int r;
dm_block_t data_block;
struct pool *pool = tc->pool;
r = alloc_data_block(tc, &data_block);
switch (r) {
case 0:
schedule_internal_copy(tc, block, lookup_result->block,
data_block, cell, bio);
break;
case -ENOSPC:
retry_bios_on_resume(pool, cell);
break;
default:
DMERR_LIMIT("%s: alloc_data_block() failed: error = %d",
__func__, r);
cell_error(pool, cell);
break;
}
}
static void __remap_and_issue_shared_cell(void *context,
struct dm_bio_prison_cell *cell)
{
struct remap_info *info = context;
struct bio *bio;
while ((bio = bio_list_pop(&cell->bios))) {
if (bio_data_dir(bio) == WRITE || op_is_flush(bio->bi_opf) ||
bio_op(bio) == REQ_OP_DISCARD)
bio_list_add(&info->defer_bios, bio);
else {
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
h->shared_read_entry = dm_deferred_entry_inc(info->tc->pool->shared_read_ds);
inc_all_io_entry(info->tc->pool, bio);
bio_list_add(&info->issue_bios, bio);
}
}
}
static void remap_and_issue_shared_cell(struct thin_c *tc,
struct dm_bio_prison_cell *cell,
dm_block_t block)
{
struct bio *bio;
struct remap_info info;
info.tc = tc;
bio_list_init(&info.defer_bios);
bio_list_init(&info.issue_bios);
cell_visit_release(tc->pool, __remap_and_issue_shared_cell,
&info, cell);
while ((bio = bio_list_pop(&info.defer_bios)))
thin_defer_bio(tc, bio);
while ((bio = bio_list_pop(&info.issue_bios)))
remap_and_issue(tc, bio, block);
}
static void process_shared_bio(struct thin_c *tc, struct bio *bio,
dm_block_t block,
struct dm_thin_lookup_result *lookup_result,
struct dm_bio_prison_cell *virt_cell)
{
struct dm_bio_prison_cell *data_cell;
struct pool *pool = tc->pool;
struct dm_cell_key key;
/*
* If cell is already occupied, then sharing is already in the process
* of being broken so we have nothing further to do here.
*/
build_data_key(tc->td, lookup_result->block, &key);
if (bio_detain(pool, &key, bio, &data_cell)) {
cell_defer_no_holder(tc, virt_cell);
return;
}
if (bio_data_dir(bio) == WRITE && bio->bi_iter.bi_size) {
break_sharing(tc, bio, block, &key, lookup_result, data_cell);
cell_defer_no_holder(tc, virt_cell);
} else {
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
h->shared_read_entry = dm_deferred_entry_inc(pool->shared_read_ds);
inc_all_io_entry(pool, bio);
remap_and_issue(tc, bio, lookup_result->block);
remap_and_issue_shared_cell(tc, data_cell, lookup_result->block);
remap_and_issue_shared_cell(tc, virt_cell, lookup_result->block);
}
}
static void provision_block(struct thin_c *tc, struct bio *bio, dm_block_t block,
struct dm_bio_prison_cell *cell)
{
int r;
dm_block_t data_block;
struct pool *pool = tc->pool;
/*
* Remap empty bios (flushes) immediately, without provisioning.
*/
if (!bio->bi_iter.bi_size) {
inc_all_io_entry(pool, bio);
cell_defer_no_holder(tc, cell);
remap_and_issue(tc, bio, 0);
return;
}
/*
* Fill read bios with zeroes and complete them immediately.
*/
if (bio_data_dir(bio) == READ) {
zero_fill_bio(bio);
cell_defer_no_holder(tc, cell);
bio_endio(bio);
return;
}
r = alloc_data_block(tc, &data_block);
switch (r) {
case 0:
if (tc->origin_dev)
schedule_external_copy(tc, block, data_block, cell, bio);
else
schedule_zero(tc, block, data_block, cell, bio);
break;
case -ENOSPC:
retry_bios_on_resume(pool, cell);
break;
default:
DMERR_LIMIT("%s: alloc_data_block() failed: error = %d",
__func__, r);
cell_error(pool, cell);
break;
}
}
static void process_cell(struct thin_c *tc, struct dm_bio_prison_cell *cell)
{
int r;
struct pool *pool = tc->pool;
struct bio *bio = cell->holder;
dm_block_t block = get_bio_block(tc, bio);
struct dm_thin_lookup_result lookup_result;
if (tc->requeue_mode) {
cell_requeue(pool, cell);
return;
}
r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
switch (r) {
case 0:
if (lookup_result.shared)
process_shared_bio(tc, bio, block, &lookup_result, cell);
else {
inc_all_io_entry(pool, bio);
remap_and_issue(tc, bio, lookup_result.block);
inc_remap_and_issue_cell(tc, cell, lookup_result.block);
}
break;
case -ENODATA:
if (bio_data_dir(bio) == READ && tc->origin_dev) {
inc_all_io_entry(pool, bio);
cell_defer_no_holder(tc, cell);
if (bio_end_sector(bio) <= tc->origin_size)
remap_to_origin_and_issue(tc, bio);
else if (bio->bi_iter.bi_sector < tc->origin_size) {
zero_fill_bio(bio);
bio->bi_iter.bi_size = (tc->origin_size - bio->bi_iter.bi_sector) << SECTOR_SHIFT;
remap_to_origin_and_issue(tc, bio);
} else {
zero_fill_bio(bio);
bio_endio(bio);
}
} else
provision_block(tc, bio, block, cell);
break;
default:
DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
__func__, r);
cell_defer_no_holder(tc, cell);
bio_io_error(bio);
break;
}
}
static void process_bio(struct thin_c *tc, struct bio *bio)
{
struct pool *pool = tc->pool;
dm_block_t block = get_bio_block(tc, bio);
struct dm_bio_prison_cell *cell;
struct dm_cell_key key;
/*
* If cell is already occupied, then the block is already
* being provisioned so we have nothing further to do here.
*/
build_virtual_key(tc->td, block, &key);
if (bio_detain(pool, &key, bio, &cell))
return;
process_cell(tc, cell);
}
static void __process_bio_read_only(struct thin_c *tc, struct bio *bio,
struct dm_bio_prison_cell *cell)
{
int r;
int rw = bio_data_dir(bio);
dm_block_t block = get_bio_block(tc, bio);
struct dm_thin_lookup_result lookup_result;
r = dm_thin_find_block(tc->td, block, 1, &lookup_result);
switch (r) {
case 0:
if (lookup_result.shared && (rw == WRITE) && bio->bi_iter.bi_size) {
handle_unserviceable_bio(tc->pool, bio);
if (cell)
cell_defer_no_holder(tc, cell);
} else {
inc_all_io_entry(tc->pool, bio);
remap_and_issue(tc, bio, lookup_result.block);
if (cell)
inc_remap_and_issue_cell(tc, cell, lookup_result.block);
}
break;
case -ENODATA:
if (cell)
cell_defer_no_holder(tc, cell);
if (rw != READ) {
handle_unserviceable_bio(tc->pool, bio);
break;
}
if (tc->origin_dev) {
inc_all_io_entry(tc->pool, bio);
remap_to_origin_and_issue(tc, bio);
break;
}
zero_fill_bio(bio);
bio_endio(bio);
break;
default:
DMERR_LIMIT("%s: dm_thin_find_block() failed: error = %d",
__func__, r);
if (cell)
cell_defer_no_holder(tc, cell);
bio_io_error(bio);
break;
}
}
static void process_bio_read_only(struct thin_c *tc, struct bio *bio)
{
__process_bio_read_only(tc, bio, NULL);
}
static void process_cell_read_only(struct thin_c *tc, struct dm_bio_prison_cell *cell)
{
__process_bio_read_only(tc, cell->holder, cell);
}
static void process_bio_success(struct thin_c *tc, struct bio *bio)
{
bio_endio(bio);
}
static void process_bio_fail(struct thin_c *tc, struct bio *bio)
{
bio_io_error(bio);
}
static void process_cell_success(struct thin_c *tc, struct dm_bio_prison_cell *cell)
{
cell_success(tc->pool, cell);
}
static void process_cell_fail(struct thin_c *tc, struct dm_bio_prison_cell *cell)
{
cell_error(tc->pool, cell);
}
/*
* FIXME: should we also commit due to size of transaction, measured in
* metadata blocks?
*/
static int need_commit_due_to_time(struct pool *pool)
{
return !time_in_range(jiffies, pool->last_commit_jiffies,
pool->last_commit_jiffies + COMMIT_PERIOD);
}
#define thin_pbd(node) rb_entry((node), struct dm_thin_endio_hook, rb_node)
#define thin_bio(pbd) dm_bio_from_per_bio_data((pbd), sizeof(struct dm_thin_endio_hook))
static void __thin_bio_rb_add(struct thin_c *tc, struct bio *bio)
{
struct rb_node **rbp, *parent;
struct dm_thin_endio_hook *pbd;
sector_t bi_sector = bio->bi_iter.bi_sector;
rbp = &tc->sort_bio_list.rb_node;
parent = NULL;
while (*rbp) {
parent = *rbp;
pbd = thin_pbd(parent);
if (bi_sector < thin_bio(pbd)->bi_iter.bi_sector)
rbp = &(*rbp)->rb_left;
else
rbp = &(*rbp)->rb_right;
}
pbd = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
rb_link_node(&pbd->rb_node, parent, rbp);
rb_insert_color(&pbd->rb_node, &tc->sort_bio_list);
}
static void __extract_sorted_bios(struct thin_c *tc)
{
struct rb_node *node;
struct dm_thin_endio_hook *pbd;
struct bio *bio;
for (node = rb_first(&tc->sort_bio_list); node; node = rb_next(node)) {
pbd = thin_pbd(node);
bio = thin_bio(pbd);
bio_list_add(&tc->deferred_bio_list, bio);
rb_erase(&pbd->rb_node, &tc->sort_bio_list);
}
WARN_ON(!RB_EMPTY_ROOT(&tc->sort_bio_list));
}
static void __sort_thin_deferred_bios(struct thin_c *tc)
{
struct bio *bio;
struct bio_list bios;
bio_list_init(&bios);
bio_list_merge(&bios, &tc->deferred_bio_list);
bio_list_init(&tc->deferred_bio_list);
/* Sort deferred_bio_list using rb-tree */
while ((bio = bio_list_pop(&bios)))
__thin_bio_rb_add(tc, bio);
/*
* Transfer the sorted bios in sort_bio_list back to
* deferred_bio_list to allow lockless submission of
* all bios.
*/
__extract_sorted_bios(tc);
}
static void process_thin_deferred_bios(struct thin_c *tc)
{
struct pool *pool = tc->pool;
struct bio *bio;
struct bio_list bios;
struct blk_plug plug;
unsigned int count = 0;
if (tc->requeue_mode) {
error_thin_bio_list(tc, &tc->deferred_bio_list,
BLK_STS_DM_REQUEUE);
return;
}
bio_list_init(&bios);
spin_lock_irq(&tc->lock);
if (bio_list_empty(&tc->deferred_bio_list)) {
spin_unlock_irq(&tc->lock);
return;
}
__sort_thin_deferred_bios(tc);
bio_list_merge(&bios, &tc->deferred_bio_list);
bio_list_init(&tc->deferred_bio_list);
spin_unlock_irq(&tc->lock);
blk_start_plug(&plug);
while ((bio = bio_list_pop(&bios))) {
/*
* If we've got no free new_mapping structs, and processing
* this bio might require one, we pause until there are some
* prepared mappings to process.
*/
if (ensure_next_mapping(pool)) {
spin_lock_irq(&tc->lock);
bio_list_add(&tc->deferred_bio_list, bio);
bio_list_merge(&tc->deferred_bio_list, &bios);
spin_unlock_irq(&tc->lock);
break;
}
if (bio_op(bio) == REQ_OP_DISCARD)
pool->process_discard(tc, bio);
else
pool->process_bio(tc, bio);
if ((count++ & 127) == 0) {
throttle_work_update(&pool->throttle);
dm_pool_issue_prefetches(pool->pmd);
}
cond_resched();
}
blk_finish_plug(&plug);
}
static int cmp_cells(const void *lhs, const void *rhs)
{
struct dm_bio_prison_cell *lhs_cell = *((struct dm_bio_prison_cell **) lhs);
struct dm_bio_prison_cell *rhs_cell = *((struct dm_bio_prison_cell **) rhs);
BUG_ON(!lhs_cell->holder);
BUG_ON(!rhs_cell->holder);
if (lhs_cell->holder->bi_iter.bi_sector < rhs_cell->holder->bi_iter.bi_sector)
return -1;
if (lhs_cell->holder->bi_iter.bi_sector > rhs_cell->holder->bi_iter.bi_sector)
return 1;
return 0;
}
static unsigned int sort_cells(struct pool *pool, struct list_head *cells)
{
unsigned int count = 0;
struct dm_bio_prison_cell *cell, *tmp;
list_for_each_entry_safe(cell, tmp, cells, user_list) {
if (count >= CELL_SORT_ARRAY_SIZE)
break;
pool->cell_sort_array[count++] = cell;
list_del(&cell->user_list);
}
sort(pool->cell_sort_array, count, sizeof(cell), cmp_cells, NULL);
return count;
}
static void process_thin_deferred_cells(struct thin_c *tc)
{
struct pool *pool = tc->pool;
struct list_head cells;
struct dm_bio_prison_cell *cell;
unsigned int i, j, count;
INIT_LIST_HEAD(&cells);
spin_lock_irq(&tc->lock);
list_splice_init(&tc->deferred_cells, &cells);
spin_unlock_irq(&tc->lock);
if (list_empty(&cells))
return;
do {
count = sort_cells(tc->pool, &cells);
for (i = 0; i < count; i++) {
cell = pool->cell_sort_array[i];
BUG_ON(!cell->holder);
/*
* If we've got no free new_mapping structs, and processing
* this bio might require one, we pause until there are some
* prepared mappings to process.
*/
if (ensure_next_mapping(pool)) {
for (j = i; j < count; j++)
list_add(&pool->cell_sort_array[j]->user_list, &cells);
spin_lock_irq(&tc->lock);
list_splice(&cells, &tc->deferred_cells);
spin_unlock_irq(&tc->lock);
return;
}
if (bio_op(cell->holder) == REQ_OP_DISCARD)
pool->process_discard_cell(tc, cell);
else
pool->process_cell(tc, cell);
}
cond_resched();
} while (!list_empty(&cells));
}
static void thin_get(struct thin_c *tc);
static void thin_put(struct thin_c *tc);
/*
* We can't hold rcu_read_lock() around code that can block. So we
* find a thin with the rcu lock held; bump a refcount; then drop
* the lock.
*/
static struct thin_c *get_first_thin(struct pool *pool)
{
struct thin_c *tc = NULL;
rcu_read_lock();
if (!list_empty(&pool->active_thins)) {
tc = list_entry_rcu(pool->active_thins.next, struct thin_c, list);
thin_get(tc);
}
rcu_read_unlock();
return tc;
}
static struct thin_c *get_next_thin(struct pool *pool, struct thin_c *tc)
{
struct thin_c *old_tc = tc;
rcu_read_lock();
list_for_each_entry_continue_rcu(tc, &pool->active_thins, list) {
thin_get(tc);
thin_put(old_tc);
rcu_read_unlock();
return tc;
}
thin_put(old_tc);
rcu_read_unlock();
return NULL;
}
static void process_deferred_bios(struct pool *pool)
{
struct bio *bio;
struct bio_list bios, bio_completions;
struct thin_c *tc;
tc = get_first_thin(pool);
while (tc) {
process_thin_deferred_cells(tc);
process_thin_deferred_bios(tc);
tc = get_next_thin(pool, tc);
}
/*
* If there are any deferred flush bios, we must commit the metadata
* before issuing them or signaling their completion.
*/
bio_list_init(&bios);
bio_list_init(&bio_completions);
spin_lock_irq(&pool->lock);
bio_list_merge(&bios, &pool->deferred_flush_bios);
bio_list_init(&pool->deferred_flush_bios);
bio_list_merge(&bio_completions, &pool->deferred_flush_completions);
bio_list_init(&pool->deferred_flush_completions);
spin_unlock_irq(&pool->lock);
if (bio_list_empty(&bios) && bio_list_empty(&bio_completions) &&
!(dm_pool_changed_this_transaction(pool->pmd) && need_commit_due_to_time(pool)))
return;
if (commit(pool)) {
bio_list_merge(&bios, &bio_completions);
while ((bio = bio_list_pop(&bios)))
bio_io_error(bio);
return;
}
pool->last_commit_jiffies = jiffies;
while ((bio = bio_list_pop(&bio_completions)))
bio_endio(bio);
while ((bio = bio_list_pop(&bios))) {
/*
* The data device was flushed as part of metadata commit,
* so complete redundant flushes immediately.
*/
if (bio->bi_opf & REQ_PREFLUSH)
bio_endio(bio);
else
dm_submit_bio_remap(bio, NULL);
}
}
static void do_worker(struct work_struct *ws)
{
struct pool *pool = container_of(ws, struct pool, worker);
throttle_work_start(&pool->throttle);
dm_pool_issue_prefetches(pool->pmd);
throttle_work_update(&pool->throttle);
process_prepared(pool, &pool->prepared_mappings, &pool->process_prepared_mapping);
throttle_work_update(&pool->throttle);
process_prepared(pool, &pool->prepared_discards, &pool->process_prepared_discard);
throttle_work_update(&pool->throttle);
process_prepared(pool, &pool->prepared_discards_pt2, &pool->process_prepared_discard_pt2);
throttle_work_update(&pool->throttle);
process_deferred_bios(pool);
throttle_work_complete(&pool->throttle);
}
/*
* We want to commit periodically so that not too much
* unwritten data builds up.
*/
static void do_waker(struct work_struct *ws)
{
struct pool *pool = container_of(to_delayed_work(ws), struct pool, waker);
wake_worker(pool);
queue_delayed_work(pool->wq, &pool->waker, COMMIT_PERIOD);
}
/*
* We're holding onto IO to allow userland time to react. After the
* timeout either the pool will have been resized (and thus back in
* PM_WRITE mode), or we degrade to PM_OUT_OF_DATA_SPACE w/ error_if_no_space.
*/
static void do_no_space_timeout(struct work_struct *ws)
{
struct pool *pool = container_of(to_delayed_work(ws), struct pool,
no_space_timeout);
if (get_pool_mode(pool) == PM_OUT_OF_DATA_SPACE && !pool->pf.error_if_no_space) {
pool->pf.error_if_no_space = true;
notify_of_pool_mode_change(pool);
error_retry_list_with_code(pool, BLK_STS_NOSPC);
}
}
/*----------------------------------------------------------------*/
struct pool_work {
struct work_struct worker;
struct completion complete;
};
static struct pool_work *to_pool_work(struct work_struct *ws)
{
return container_of(ws, struct pool_work, worker);
}
static void pool_work_complete(struct pool_work *pw)
{
complete(&pw->complete);
}
static void pool_work_wait(struct pool_work *pw, struct pool *pool,
void (*fn)(struct work_struct *))
{
INIT_WORK_ONSTACK(&pw->worker, fn);
init_completion(&pw->complete);
queue_work(pool->wq, &pw->worker);
wait_for_completion(&pw->complete);
}
/*----------------------------------------------------------------*/
struct noflush_work {
struct pool_work pw;
struct thin_c *tc;
};
static struct noflush_work *to_noflush(struct work_struct *ws)
{
return container_of(to_pool_work(ws), struct noflush_work, pw);
}
static void do_noflush_start(struct work_struct *ws)
{
struct noflush_work *w = to_noflush(ws);
w->tc->requeue_mode = true;
requeue_io(w->tc);
pool_work_complete(&w->pw);
}
static void do_noflush_stop(struct work_struct *ws)
{
struct noflush_work *w = to_noflush(ws);
w->tc->requeue_mode = false;
pool_work_complete(&w->pw);
}
static void noflush_work(struct thin_c *tc, void (*fn)(struct work_struct *))
{
struct noflush_work w;
w.tc = tc;
pool_work_wait(&w.pw, tc->pool, fn);
}
/*----------------------------------------------------------------*/
static void set_discard_callbacks(struct pool *pool)
{
struct pool_c *pt = pool->ti->private;
if (pt->adjusted_pf.discard_passdown) {
pool->process_discard_cell = process_discard_cell_passdown;
pool->process_prepared_discard = process_prepared_discard_passdown_pt1;
pool->process_prepared_discard_pt2 = process_prepared_discard_passdown_pt2;
} else {
pool->process_discard_cell = process_discard_cell_no_passdown;
pool->process_prepared_discard = process_prepared_discard_no_passdown;
}
}
static void set_pool_mode(struct pool *pool, enum pool_mode new_mode)
{
struct pool_c *pt = pool->ti->private;
bool needs_check = dm_pool_metadata_needs_check(pool->pmd);
enum pool_mode old_mode = get_pool_mode(pool);
unsigned long no_space_timeout = READ_ONCE(no_space_timeout_secs) * HZ;
/*
* Never allow the pool to transition to PM_WRITE mode if user
* intervention is required to verify metadata and data consistency.
*/
if (new_mode == PM_WRITE && needs_check) {
DMERR("%s: unable to switch pool to write mode until repaired.",
dm_device_name(pool->pool_md));
if (old_mode != new_mode)
new_mode = old_mode;
else
new_mode = PM_READ_ONLY;
}
/*
* If we were in PM_FAIL mode, rollback of metadata failed. We're
* not going to recover without a thin_repair. So we never let the
* pool move out of the old mode.
*/
if (old_mode == PM_FAIL)
new_mode = old_mode;
switch (new_mode) {
case PM_FAIL:
dm_pool_metadata_read_only(pool->pmd);
pool->process_bio = process_bio_fail;
pool->process_discard = process_bio_fail;
pool->process_cell = process_cell_fail;
pool->process_discard_cell = process_cell_fail;
pool->process_prepared_mapping = process_prepared_mapping_fail;
pool->process_prepared_discard = process_prepared_discard_fail;
error_retry_list(pool);
break;
case PM_OUT_OF_METADATA_SPACE:
case PM_READ_ONLY:
dm_pool_metadata_read_only(pool->pmd);
pool->process_bio = process_bio_read_only;
pool->process_discard = process_bio_success;
pool->process_cell = process_cell_read_only;
pool->process_discard_cell = process_cell_success;
pool->process_prepared_mapping = process_prepared_mapping_fail;
pool->process_prepared_discard = process_prepared_discard_success;
error_retry_list(pool);
break;
case PM_OUT_OF_DATA_SPACE:
/*
* Ideally we'd never hit this state; the low water mark
* would trigger userland to extend the pool before we
* completely run out of data space. However, many small
* IOs to unprovisioned space can consume data space at an
* alarming rate. Adjust your low water mark if you're
* frequently seeing this mode.
*/
pool->out_of_data_space = true;
pool->process_bio = process_bio_read_only;
pool->process_discard = process_discard_bio;
pool->process_cell = process_cell_read_only;
pool->process_prepared_mapping = process_prepared_mapping;
set_discard_callbacks(pool);
if (!pool->pf.error_if_no_space && no_space_timeout)
queue_delayed_work(pool->wq, &pool->no_space_timeout, no_space_timeout);
break;
case PM_WRITE:
if (old_mode == PM_OUT_OF_DATA_SPACE)
cancel_delayed_work_sync(&pool->no_space_timeout);
pool->out_of_data_space = false;
pool->pf.error_if_no_space = pt->requested_pf.error_if_no_space;
dm_pool_metadata_read_write(pool->pmd);
pool->process_bio = process_bio;
pool->process_discard = process_discard_bio;
pool->process_cell = process_cell;
pool->process_prepared_mapping = process_prepared_mapping;
set_discard_callbacks(pool);
break;
}
pool->pf.mode = new_mode;
/*
* The pool mode may have changed, sync it so bind_control_target()
* doesn't cause an unexpected mode transition on resume.
*/
pt->adjusted_pf.mode = new_mode;
if (old_mode != new_mode)
notify_of_pool_mode_change(pool);
}
static void abort_transaction(struct pool *pool)
{
const char *dev_name = dm_device_name(pool->pool_md);
DMERR_LIMIT("%s: aborting current metadata transaction", dev_name);
if (dm_pool_abort_metadata(pool->pmd)) {
DMERR("%s: failed to abort metadata transaction", dev_name);
set_pool_mode(pool, PM_FAIL);
}
if (dm_pool_metadata_set_needs_check(pool->pmd)) {
DMERR("%s: failed to set 'needs_check' flag in metadata", dev_name);
set_pool_mode(pool, PM_FAIL);
}
}
static void metadata_operation_failed(struct pool *pool, const char *op, int r)
{
DMERR_LIMIT("%s: metadata operation '%s' failed: error = %d",
dm_device_name(pool->pool_md), op, r);
abort_transaction(pool);
set_pool_mode(pool, PM_READ_ONLY);
}
/*----------------------------------------------------------------*/
/*
* Mapping functions.
*/
/*
* Called only while mapping a thin bio to hand it over to the workqueue.
*/
static void thin_defer_bio(struct thin_c *tc, struct bio *bio)
{
struct pool *pool = tc->pool;
spin_lock_irq(&tc->lock);
bio_list_add(&tc->deferred_bio_list, bio);
spin_unlock_irq(&tc->lock);
wake_worker(pool);
}
static void thin_defer_bio_with_throttle(struct thin_c *tc, struct bio *bio)
{
struct pool *pool = tc->pool;
throttle_lock(&pool->throttle);
thin_defer_bio(tc, bio);
throttle_unlock(&pool->throttle);
}
static void thin_defer_cell(struct thin_c *tc, struct dm_bio_prison_cell *cell)
{
struct pool *pool = tc->pool;
throttle_lock(&pool->throttle);
spin_lock_irq(&tc->lock);
list_add_tail(&cell->user_list, &tc->deferred_cells);
spin_unlock_irq(&tc->lock);
throttle_unlock(&pool->throttle);
wake_worker(pool);
}
static void thin_hook_bio(struct thin_c *tc, struct bio *bio)
{
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
h->tc = tc;
h->shared_read_entry = NULL;
h->all_io_entry = NULL;
h->overwrite_mapping = NULL;
h->cell = NULL;
}
/*
* Non-blocking function called from the thin target's map function.
*/
static int thin_bio_map(struct dm_target *ti, struct bio *bio)
{
int r;
struct thin_c *tc = ti->private;
dm_block_t block = get_bio_block(tc, bio);
struct dm_thin_device *td = tc->td;
struct dm_thin_lookup_result result;
struct dm_bio_prison_cell *virt_cell, *data_cell;
struct dm_cell_key key;
thin_hook_bio(tc, bio);
if (tc->requeue_mode) {
bio->bi_status = BLK_STS_DM_REQUEUE;
bio_endio(bio);
return DM_MAPIO_SUBMITTED;
}
if (get_pool_mode(tc->pool) == PM_FAIL) {
bio_io_error(bio);
return DM_MAPIO_SUBMITTED;
}
if (op_is_flush(bio->bi_opf) || bio_op(bio) == REQ_OP_DISCARD) {
thin_defer_bio_with_throttle(tc, bio);
return DM_MAPIO_SUBMITTED;
}
/*
* We must hold the virtual cell before doing the lookup, otherwise
* there's a race with discard.
*/
build_virtual_key(tc->td, block, &key);
if (bio_detain(tc->pool, &key, bio, &virt_cell))
return DM_MAPIO_SUBMITTED;
r = dm_thin_find_block(td, block, 0, &result);
/*
* Note that we defer readahead too.
*/
switch (r) {
case 0:
if (unlikely(result.shared)) {
/*
* We have a race condition here between the
* result.shared value returned by the lookup and
* snapshot creation, which may cause new
* sharing.
*
* To avoid this always quiesce the origin before
* taking the snap. You want to do this anyway to
* ensure a consistent application view
* (i.e. lockfs).
*
* More distant ancestors are irrelevant. The
* shared flag will be set in their case.
*/
thin_defer_cell(tc, virt_cell);
return DM_MAPIO_SUBMITTED;
}
build_data_key(tc->td, result.block, &key);
if (bio_detain(tc->pool, &key, bio, &data_cell)) {
cell_defer_no_holder(tc, virt_cell);
return DM_MAPIO_SUBMITTED;
}
inc_all_io_entry(tc->pool, bio);
cell_defer_no_holder(tc, data_cell);
cell_defer_no_holder(tc, virt_cell);
remap(tc, bio, result.block);
return DM_MAPIO_REMAPPED;
case -ENODATA:
case -EWOULDBLOCK:
thin_defer_cell(tc, virt_cell);
return DM_MAPIO_SUBMITTED;
default:
/*
* Must always call bio_io_error on failure.
* dm_thin_find_block can fail with -EINVAL if the
* pool is switched to fail-io mode.
*/
bio_io_error(bio);
cell_defer_no_holder(tc, virt_cell);
return DM_MAPIO_SUBMITTED;
}
}
static void requeue_bios(struct pool *pool)
{
struct thin_c *tc;
rcu_read_lock();
list_for_each_entry_rcu(tc, &pool->active_thins, list) {
spin_lock_irq(&tc->lock);
bio_list_merge(&tc->deferred_bio_list, &tc->retry_on_resume_list);
bio_list_init(&tc->retry_on_resume_list);
spin_unlock_irq(&tc->lock);
}
rcu_read_unlock();
}
/*
*--------------------------------------------------------------
* Binding of control targets to a pool object
*--------------------------------------------------------------
*/
static bool is_factor(sector_t block_size, uint32_t n)
{
return !sector_div(block_size, n);
}
/*
* If discard_passdown was enabled verify that the data device
* supports discards. Disable discard_passdown if not.
*/
static void disable_discard_passdown_if_not_supported(struct pool_c *pt)
{
struct pool *pool = pt->pool;
struct block_device *data_bdev = pt->data_dev->bdev;
struct queue_limits *data_limits = &bdev_get_queue(data_bdev)->limits;
const char *reason = NULL;
if (!pt->adjusted_pf.discard_passdown)
return;
if (!bdev_max_discard_sectors(pt->data_dev->bdev))
reason = "discard unsupported";
else if (data_limits->max_discard_sectors < pool->sectors_per_block)
reason = "max discard sectors smaller than a block";
if (reason) {
DMWARN("Data device (%pg) %s: Disabling discard passdown.", data_bdev, reason);
pt->adjusted_pf.discard_passdown = false;
}
}
static int bind_control_target(struct pool *pool, struct dm_target *ti)
{
struct pool_c *pt = ti->private;
/*
* We want to make sure that a pool in PM_FAIL mode is never upgraded.
*/
enum pool_mode old_mode = get_pool_mode(pool);
enum pool_mode new_mode = pt->adjusted_pf.mode;
/*
* Don't change the pool's mode until set_pool_mode() below.
* Otherwise the pool's process_* function pointers may
* not match the desired pool mode.
*/
pt->adjusted_pf.mode = old_mode;
pool->ti = ti;
pool->pf = pt->adjusted_pf;
pool->low_water_blocks = pt->low_water_blocks;
set_pool_mode(pool, new_mode);
return 0;
}
static void unbind_control_target(struct pool *pool, struct dm_target *ti)
{
if (pool->ti == ti)
pool->ti = NULL;
}
/*
*--------------------------------------------------------------
* Pool creation
*--------------------------------------------------------------
*/
/* Initialize pool features. */
static void pool_features_init(struct pool_features *pf)
{
pf->mode = PM_WRITE;
pf->zero_new_blocks = true;
pf->discard_enabled = true;
pf->discard_passdown = true;
pf->error_if_no_space = false;
}
static void __pool_destroy(struct pool *pool)
{
__pool_table_remove(pool);
vfree(pool->cell_sort_array);
if (dm_pool_metadata_close(pool->pmd) < 0)
DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
dm_bio_prison_destroy(pool->prison);
dm_kcopyd_client_destroy(pool->copier);
cancel_delayed_work_sync(&pool->waker);
cancel_delayed_work_sync(&pool->no_space_timeout);
if (pool->wq)
destroy_workqueue(pool->wq);
if (pool->next_mapping)
mempool_free(pool->next_mapping, &pool->mapping_pool);
mempool_exit(&pool->mapping_pool);
dm_deferred_set_destroy(pool->shared_read_ds);
dm_deferred_set_destroy(pool->all_io_ds);
kfree(pool);
}
static struct kmem_cache *_new_mapping_cache;
static struct pool *pool_create(struct mapped_device *pool_md,
struct block_device *metadata_dev,
struct block_device *data_dev,
unsigned long block_size,
int read_only, char **error)
{
int r;
void *err_p;
struct pool *pool;
struct dm_pool_metadata *pmd;
bool format_device = read_only ? false : true;
pmd = dm_pool_metadata_open(metadata_dev, block_size, format_device);
if (IS_ERR(pmd)) {
*error = "Error creating metadata object";
return (struct pool *)pmd;
}
pool = kzalloc(sizeof(*pool), GFP_KERNEL);
if (!pool) {
*error = "Error allocating memory for pool";
err_p = ERR_PTR(-ENOMEM);
goto bad_pool;
}
pool->pmd = pmd;
pool->sectors_per_block = block_size;
if (block_size & (block_size - 1))
pool->sectors_per_block_shift = -1;
else
pool->sectors_per_block_shift = __ffs(block_size);
pool->low_water_blocks = 0;
pool_features_init(&pool->pf);
pool->prison = dm_bio_prison_create();
if (!pool->prison) {
*error = "Error creating pool's bio prison";
err_p = ERR_PTR(-ENOMEM);
goto bad_prison;
}
pool->copier = dm_kcopyd_client_create(&dm_kcopyd_throttle);
if (IS_ERR(pool->copier)) {
r = PTR_ERR(pool->copier);
*error = "Error creating pool's kcopyd client";
err_p = ERR_PTR(r);
goto bad_kcopyd_client;
}
/*
* Create singlethreaded workqueue that will service all devices
* that use this metadata.
*/
pool->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM);
if (!pool->wq) {
*error = "Error creating pool's workqueue";
err_p = ERR_PTR(-ENOMEM);
goto bad_wq;
}
throttle_init(&pool->throttle);
INIT_WORK(&pool->worker, do_worker);
INIT_DELAYED_WORK(&pool->waker, do_waker);
INIT_DELAYED_WORK(&pool->no_space_timeout, do_no_space_timeout);
spin_lock_init(&pool->lock);
bio_list_init(&pool->deferred_flush_bios);
bio_list_init(&pool->deferred_flush_completions);
INIT_LIST_HEAD(&pool->prepared_mappings);
INIT_LIST_HEAD(&pool->prepared_discards);
INIT_LIST_HEAD(&pool->prepared_discards_pt2);
INIT_LIST_HEAD(&pool->active_thins);
pool->low_water_triggered = false;
pool->suspended = true;
pool->out_of_data_space = false;
pool->shared_read_ds = dm_deferred_set_create();
if (!pool->shared_read_ds) {
*error = "Error creating pool's shared read deferred set";
err_p = ERR_PTR(-ENOMEM);
goto bad_shared_read_ds;
}
pool->all_io_ds = dm_deferred_set_create();
if (!pool->all_io_ds) {
*error = "Error creating pool's all io deferred set";
err_p = ERR_PTR(-ENOMEM);
goto bad_all_io_ds;
}
pool->next_mapping = NULL;
r = mempool_init_slab_pool(&pool->mapping_pool, MAPPING_POOL_SIZE,
_new_mapping_cache);
if (r) {
*error = "Error creating pool's mapping mempool";
err_p = ERR_PTR(r);
goto bad_mapping_pool;
}
pool->cell_sort_array =
vmalloc(array_size(CELL_SORT_ARRAY_SIZE,
sizeof(*pool->cell_sort_array)));
if (!pool->cell_sort_array) {
*error = "Error allocating cell sort array";
err_p = ERR_PTR(-ENOMEM);
goto bad_sort_array;
}
pool->ref_count = 1;
pool->last_commit_jiffies = jiffies;
pool->pool_md = pool_md;
pool->md_dev = metadata_dev;
pool->data_dev = data_dev;
__pool_table_insert(pool);
return pool;
bad_sort_array:
mempool_exit(&pool->mapping_pool);
bad_mapping_pool:
dm_deferred_set_destroy(pool->all_io_ds);
bad_all_io_ds:
dm_deferred_set_destroy(pool->shared_read_ds);
bad_shared_read_ds:
destroy_workqueue(pool->wq);
bad_wq:
dm_kcopyd_client_destroy(pool->copier);
bad_kcopyd_client:
dm_bio_prison_destroy(pool->prison);
bad_prison:
kfree(pool);
bad_pool:
if (dm_pool_metadata_close(pmd))
DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
return err_p;
}
static void __pool_inc(struct pool *pool)
{
BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
pool->ref_count++;
}
static void __pool_dec(struct pool *pool)
{
BUG_ON(!mutex_is_locked(&dm_thin_pool_table.mutex));
BUG_ON(!pool->ref_count);
if (!--pool->ref_count)
__pool_destroy(pool);
}
static struct pool *__pool_find(struct mapped_device *pool_md,
struct block_device *metadata_dev,
struct block_device *data_dev,
unsigned long block_size, int read_only,
char **error, int *created)
{
struct pool *pool = __pool_table_lookup_metadata_dev(metadata_dev);
if (pool) {
if (pool->pool_md != pool_md) {
*error = "metadata device already in use by a pool";
return ERR_PTR(-EBUSY);
}
if (pool->data_dev != data_dev) {
*error = "data device already in use by a pool";
return ERR_PTR(-EBUSY);
}
__pool_inc(pool);
} else {
pool = __pool_table_lookup(pool_md);
if (pool) {
if (pool->md_dev != metadata_dev || pool->data_dev != data_dev) {
*error = "different pool cannot replace a pool";
return ERR_PTR(-EINVAL);
}
__pool_inc(pool);
} else {
pool = pool_create(pool_md, metadata_dev, data_dev, block_size, read_only, error);
*created = 1;
}
}
return pool;
}
/*
*--------------------------------------------------------------
* Pool target methods
*--------------------------------------------------------------
*/
static void pool_dtr(struct dm_target *ti)
{
struct pool_c *pt = ti->private;
mutex_lock(&dm_thin_pool_table.mutex);
unbind_control_target(pt->pool, ti);
__pool_dec(pt->pool);
dm_put_device(ti, pt->metadata_dev);
dm_put_device(ti, pt->data_dev);
kfree(pt);
mutex_unlock(&dm_thin_pool_table.mutex);
}
static int parse_pool_features(struct dm_arg_set *as, struct pool_features *pf,
struct dm_target *ti)
{
int r;
unsigned int argc;
const char *arg_name;
static const struct dm_arg _args[] = {
{0, 4, "Invalid number of pool feature arguments"},
};
/*
* No feature arguments supplied.
*/
if (!as->argc)
return 0;
r = dm_read_arg_group(_args, as, &argc, &ti->error);
if (r)
return -EINVAL;
while (argc && !r) {
arg_name = dm_shift_arg(as);
argc--;
if (!strcasecmp(arg_name, "skip_block_zeroing"))
pf->zero_new_blocks = false;
else if (!strcasecmp(arg_name, "ignore_discard"))
pf->discard_enabled = false;
else if (!strcasecmp(arg_name, "no_discard_passdown"))
pf->discard_passdown = false;
else if (!strcasecmp(arg_name, "read_only"))
pf->mode = PM_READ_ONLY;
else if (!strcasecmp(arg_name, "error_if_no_space"))
pf->error_if_no_space = true;
else {
ti->error = "Unrecognised pool feature requested";
r = -EINVAL;
break;
}
}
return r;
}
static void metadata_low_callback(void *context)
{
struct pool *pool = context;
DMWARN("%s: reached low water mark for metadata device: sending event.",
dm_device_name(pool->pool_md));
dm_table_event(pool->ti->table);
}
/*
* We need to flush the data device **before** committing the metadata.
*
* This ensures that the data blocks of any newly inserted mappings are
* properly written to non-volatile storage and won't be lost in case of a
* crash.
*
* Failure to do so can result in data corruption in the case of internal or
* external snapshots and in the case of newly provisioned blocks, when block
* zeroing is enabled.
*/
static int metadata_pre_commit_callback(void *context)
{
struct pool *pool = context;
return blkdev_issue_flush(pool->data_dev);
}
static sector_t get_dev_size(struct block_device *bdev)
{
return bdev_nr_sectors(bdev);
}
static void warn_if_metadata_device_too_big(struct block_device *bdev)
{
sector_t metadata_dev_size = get_dev_size(bdev);
if (metadata_dev_size > THIN_METADATA_MAX_SECTORS_WARNING)
DMWARN("Metadata device %pg is larger than %u sectors: excess space will not be used.",
bdev, THIN_METADATA_MAX_SECTORS);
}
static sector_t get_metadata_dev_size(struct block_device *bdev)
{
sector_t metadata_dev_size = get_dev_size(bdev);
if (metadata_dev_size > THIN_METADATA_MAX_SECTORS)
metadata_dev_size = THIN_METADATA_MAX_SECTORS;
return metadata_dev_size;
}
static dm_block_t get_metadata_dev_size_in_blocks(struct block_device *bdev)
{
sector_t metadata_dev_size = get_metadata_dev_size(bdev);
sector_div(metadata_dev_size, THIN_METADATA_BLOCK_SIZE);
return metadata_dev_size;
}
/*
* When a metadata threshold is crossed a dm event is triggered, and
* userland should respond by growing the metadata device. We could let
* userland set the threshold, like we do with the data threshold, but I'm
* not sure they know enough to do this well.
*/
static dm_block_t calc_metadata_threshold(struct pool_c *pt)
{
/*
* 4M is ample for all ops with the possible exception of thin
* device deletion which is harmless if it fails (just retry the
* delete after you've grown the device).
*/
dm_block_t quarter = get_metadata_dev_size_in_blocks(pt->metadata_dev->bdev) / 4;
return min((dm_block_t)1024ULL /* 4M */, quarter);
}
/*
* thin-pool <metadata dev> <data dev>
* <data block size (sectors)>
* <low water mark (blocks)>
* [<#feature args> [<arg>]*]
*
* Optional feature arguments are:
* skip_block_zeroing: skips the zeroing of newly-provisioned blocks.
* ignore_discard: disable discard
* no_discard_passdown: don't pass discards down to the data device
* read_only: Don't allow any changes to be made to the pool metadata.
* error_if_no_space: error IOs, instead of queueing, if no space.
*/
static int pool_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
int r, pool_created = 0;
struct pool_c *pt;
struct pool *pool;
struct pool_features pf;
struct dm_arg_set as;
struct dm_dev *data_dev;
unsigned long block_size;
dm_block_t low_water_blocks;
struct dm_dev *metadata_dev;
blk_mode_t metadata_mode;
/*
* FIXME Remove validation from scope of lock.
*/
mutex_lock(&dm_thin_pool_table.mutex);
if (argc < 4) {
ti->error = "Invalid argument count";
r = -EINVAL;
goto out_unlock;
}
as.argc = argc;
as.argv = argv;
/* make sure metadata and data are different devices */
if (!strcmp(argv[0], argv[1])) {
ti->error = "Error setting metadata or data device";
r = -EINVAL;
goto out_unlock;
}
/*
* Set default pool features.
*/
pool_features_init(&pf);
dm_consume_args(&as, 4);
r = parse_pool_features(&as, &pf, ti);
if (r)
goto out_unlock;
metadata_mode = BLK_OPEN_READ |
((pf.mode == PM_READ_ONLY) ? 0 : BLK_OPEN_WRITE);
r = dm_get_device(ti, argv[0], metadata_mode, &metadata_dev);
if (r) {
ti->error = "Error opening metadata block device";
goto out_unlock;
}
warn_if_metadata_device_too_big(metadata_dev->bdev);
r = dm_get_device(ti, argv[1], BLK_OPEN_READ | BLK_OPEN_WRITE, &data_dev);
if (r) {
ti->error = "Error getting data device";
goto out_metadata;
}
if (kstrtoul(argv[2], 10, &block_size) || !block_size ||
block_size < DATA_DEV_BLOCK_SIZE_MIN_SECTORS ||
block_size > DATA_DEV_BLOCK_SIZE_MAX_SECTORS ||
block_size & (DATA_DEV_BLOCK_SIZE_MIN_SECTORS - 1)) {
ti->error = "Invalid block size";
r = -EINVAL;
goto out;
}
if (kstrtoull(argv[3], 10, (unsigned long long *)&low_water_blocks)) {
ti->error = "Invalid low water mark";
r = -EINVAL;
goto out;
}
pt = kzalloc(sizeof(*pt), GFP_KERNEL);
if (!pt) {
r = -ENOMEM;
goto out;
}
pool = __pool_find(dm_table_get_md(ti->table), metadata_dev->bdev, data_dev->bdev,
block_size, pf.mode == PM_READ_ONLY, &ti->error, &pool_created);
if (IS_ERR(pool)) {
r = PTR_ERR(pool);
goto out_free_pt;
}
/*
* 'pool_created' reflects whether this is the first table load.
* Top level discard support is not allowed to be changed after
* initial load. This would require a pool reload to trigger thin
* device changes.
*/
if (!pool_created && pf.discard_enabled != pool->pf.discard_enabled) {
ti->error = "Discard support cannot be disabled once enabled";
r = -EINVAL;
goto out_flags_changed;
}
pt->pool = pool;
pt->ti = ti;
pt->metadata_dev = metadata_dev;
pt->data_dev = data_dev;
pt->low_water_blocks = low_water_blocks;
pt->adjusted_pf = pt->requested_pf = pf;
ti->num_flush_bios = 1;
ti->limit_swap_bios = true;
/*
* Only need to enable discards if the pool should pass
* them down to the data device. The thin device's discard
* processing will cause mappings to be removed from the btree.
*/
if (pf.discard_enabled && pf.discard_passdown) {
ti->num_discard_bios = 1;
/*
* Setting 'discards_supported' circumvents the normal
* stacking of discard limits (this keeps the pool and
* thin devices' discard limits consistent).
*/
ti->discards_supported = true;
ti->max_discard_granularity = true;
}
ti->private = pt;
r = dm_pool_register_metadata_threshold(pt->pool->pmd,
calc_metadata_threshold(pt),
metadata_low_callback,
pool);
if (r) {
ti->error = "Error registering metadata threshold";
goto out_flags_changed;
}
dm_pool_register_pre_commit_callback(pool->pmd,
metadata_pre_commit_callback, pool);
mutex_unlock(&dm_thin_pool_table.mutex);
return 0;
out_flags_changed:
__pool_dec(pool);
out_free_pt:
kfree(pt);
out:
dm_put_device(ti, data_dev);
out_metadata:
dm_put_device(ti, metadata_dev);
out_unlock:
mutex_unlock(&dm_thin_pool_table.mutex);
return r;
}
static int pool_map(struct dm_target *ti, struct bio *bio)
{
struct pool_c *pt = ti->private;
struct pool *pool = pt->pool;
/*
* As this is a singleton target, ti->begin is always zero.
*/
spin_lock_irq(&pool->lock);
bio_set_dev(bio, pt->data_dev->bdev);
spin_unlock_irq(&pool->lock);
return DM_MAPIO_REMAPPED;
}
static int maybe_resize_data_dev(struct dm_target *ti, bool *need_commit)
{
int r;
struct pool_c *pt = ti->private;
struct pool *pool = pt->pool;
sector_t data_size = ti->len;
dm_block_t sb_data_size;
*need_commit = false;
(void) sector_div(data_size, pool->sectors_per_block);
r = dm_pool_get_data_dev_size(pool->pmd, &sb_data_size);
if (r) {
DMERR("%s: failed to retrieve data device size",
dm_device_name(pool->pool_md));
return r;
}
if (data_size < sb_data_size) {
DMERR("%s: pool target (%llu blocks) too small: expected %llu",
dm_device_name(pool->pool_md),
(unsigned long long)data_size, sb_data_size);
return -EINVAL;
} else if (data_size > sb_data_size) {
if (dm_pool_metadata_needs_check(pool->pmd)) {
DMERR("%s: unable to grow the data device until repaired.",
dm_device_name(pool->pool_md));
return 0;
}
if (sb_data_size)
DMINFO("%s: growing the data device from %llu to %llu blocks",
dm_device_name(pool->pool_md),
sb_data_size, (unsigned long long)data_size);
r = dm_pool_resize_data_dev(pool->pmd, data_size);
if (r) {
metadata_operation_failed(pool, "dm_pool_resize_data_dev", r);
return r;
}
*need_commit = true;
}
return 0;
}
static int maybe_resize_metadata_dev(struct dm_target *ti, bool *need_commit)
{
int r;
struct pool_c *pt = ti->private;
struct pool *pool = pt->pool;
dm_block_t metadata_dev_size, sb_metadata_dev_size;
*need_commit = false;
metadata_dev_size = get_metadata_dev_size_in_blocks(pool->md_dev);
r = dm_pool_get_metadata_dev_size(pool->pmd, &sb_metadata_dev_size);
if (r) {
DMERR("%s: failed to retrieve metadata device size",
dm_device_name(pool->pool_md));
return r;
}
if (metadata_dev_size < sb_metadata_dev_size) {
DMERR("%s: metadata device (%llu blocks) too small: expected %llu",
dm_device_name(pool->pool_md),
metadata_dev_size, sb_metadata_dev_size);
return -EINVAL;
} else if (metadata_dev_size > sb_metadata_dev_size) {
if (dm_pool_metadata_needs_check(pool->pmd)) {
DMERR("%s: unable to grow the metadata device until repaired.",
dm_device_name(pool->pool_md));
return 0;
}
warn_if_metadata_device_too_big(pool->md_dev);
DMINFO("%s: growing the metadata device from %llu to %llu blocks",
dm_device_name(pool->pool_md),
sb_metadata_dev_size, metadata_dev_size);
if (get_pool_mode(pool) == PM_OUT_OF_METADATA_SPACE)
set_pool_mode(pool, PM_WRITE);
r = dm_pool_resize_metadata_dev(pool->pmd, metadata_dev_size);
if (r) {
metadata_operation_failed(pool, "dm_pool_resize_metadata_dev", r);
return r;
}
*need_commit = true;
}
return 0;
}
/*
* Retrieves the number of blocks of the data device from
* the superblock and compares it to the actual device size,
* thus resizing the data device in case it has grown.
*
* This both copes with opening preallocated data devices in the ctr
* being followed by a resume
* -and-
* calling the resume method individually after userspace has
* grown the data device in reaction to a table event.
*/
static int pool_preresume(struct dm_target *ti)
{
int r;
bool need_commit1, need_commit2;
struct pool_c *pt = ti->private;
struct pool *pool = pt->pool;
/*
* Take control of the pool object.
*/
r = bind_control_target(pool, ti);
if (r)
goto out;
r = maybe_resize_data_dev(ti, &need_commit1);
if (r)
goto out;
r = maybe_resize_metadata_dev(ti, &need_commit2);
if (r)
goto out;
if (need_commit1 || need_commit2)
(void) commit(pool);
out:
/*
* When a thin-pool is PM_FAIL, it cannot be rebuilt if
* bio is in deferred list. Therefore need to return 0
* to allow pool_resume() to flush IO.
*/
if (r && get_pool_mode(pool) == PM_FAIL)
r = 0;
return r;
}
static void pool_suspend_active_thins(struct pool *pool)
{
struct thin_c *tc;
/* Suspend all active thin devices */
tc = get_first_thin(pool);
while (tc) {
dm_internal_suspend_noflush(tc->thin_md);
tc = get_next_thin(pool, tc);
}
}
static void pool_resume_active_thins(struct pool *pool)
{
struct thin_c *tc;
/* Resume all active thin devices */
tc = get_first_thin(pool);
while (tc) {
dm_internal_resume(tc->thin_md);
tc = get_next_thin(pool, tc);
}
}
static void pool_resume(struct dm_target *ti)
{
struct pool_c *pt = ti->private;
struct pool *pool = pt->pool;
/*
* Must requeue active_thins' bios and then resume
* active_thins _before_ clearing 'suspend' flag.
*/
requeue_bios(pool);
pool_resume_active_thins(pool);
spin_lock_irq(&pool->lock);
pool->low_water_triggered = false;
pool->suspended = false;
spin_unlock_irq(&pool->lock);
do_waker(&pool->waker.work);
}
static void pool_presuspend(struct dm_target *ti)
{
struct pool_c *pt = ti->private;
struct pool *pool = pt->pool;
spin_lock_irq(&pool->lock);
pool->suspended = true;
spin_unlock_irq(&pool->lock);
pool_suspend_active_thins(pool);
}
static void pool_presuspend_undo(struct dm_target *ti)
{
struct pool_c *pt = ti->private;
struct pool *pool = pt->pool;
pool_resume_active_thins(pool);
spin_lock_irq(&pool->lock);
pool->suspended = false;
spin_unlock_irq(&pool->lock);
}
static void pool_postsuspend(struct dm_target *ti)
{
struct pool_c *pt = ti->private;
struct pool *pool = pt->pool;
cancel_delayed_work_sync(&pool->waker);
cancel_delayed_work_sync(&pool->no_space_timeout);
flush_workqueue(pool->wq);
(void) commit(pool);
}
static int check_arg_count(unsigned int argc, unsigned int args_required)
{
if (argc != args_required) {
DMWARN("Message received with %u arguments instead of %u.",
argc, args_required);
return -EINVAL;
}
return 0;
}
static int read_dev_id(char *arg, dm_thin_id *dev_id, int warning)
{
if (!kstrtoull(arg, 10, (unsigned long long *)dev_id) &&
*dev_id <= MAX_DEV_ID)
return 0;
if (warning)
DMWARN("Message received with invalid device id: %s", arg);
return -EINVAL;
}
static int process_create_thin_mesg(unsigned int argc, char **argv, struct pool *pool)
{
dm_thin_id dev_id;
int r;
r = check_arg_count(argc, 2);
if (r)
return r;
r = read_dev_id(argv[1], &dev_id, 1);
if (r)
return r;
r = dm_pool_create_thin(pool->pmd, dev_id);
if (r) {
DMWARN("Creation of new thinly-provisioned device with id %s failed.",
argv[1]);
return r;
}
return 0;
}
static int process_create_snap_mesg(unsigned int argc, char **argv, struct pool *pool)
{
dm_thin_id dev_id;
dm_thin_id origin_dev_id;
int r;
r = check_arg_count(argc, 3);
if (r)
return r;
r = read_dev_id(argv[1], &dev_id, 1);
if (r)
return r;
r = read_dev_id(argv[2], &origin_dev_id, 1);
if (r)
return r;
r = dm_pool_create_snap(pool->pmd, dev_id, origin_dev_id);
if (r) {
DMWARN("Creation of new snapshot %s of device %s failed.",
argv[1], argv[2]);
return r;
}
return 0;
}
static int process_delete_mesg(unsigned int argc, char **argv, struct pool *pool)
{
dm_thin_id dev_id;
int r;
r = check_arg_count(argc, 2);
if (r)
return r;
r = read_dev_id(argv[1], &dev_id, 1);
if (r)
return r;
r = dm_pool_delete_thin_device(pool->pmd, dev_id);
if (r)
DMWARN("Deletion of thin device %s failed.", argv[1]);
return r;
}
static int process_set_transaction_id_mesg(unsigned int argc, char **argv, struct pool *pool)
{
dm_thin_id old_id, new_id;
int r;
r = check_arg_count(argc, 3);
if (r)
return r;
if (kstrtoull(argv[1], 10, (unsigned long long *)&old_id)) {
DMWARN("set_transaction_id message: Unrecognised id %s.", argv[1]);
return -EINVAL;
}
if (kstrtoull(argv[2], 10, (unsigned long long *)&new_id)) {
DMWARN("set_transaction_id message: Unrecognised new id %s.", argv[2]);
return -EINVAL;
}
r = dm_pool_set_metadata_transaction_id(pool->pmd, old_id, new_id);
if (r) {
DMWARN("Failed to change transaction id from %s to %s.",
argv[1], argv[2]);
return r;
}
return 0;
}
static int process_reserve_metadata_snap_mesg(unsigned int argc, char **argv, struct pool *pool)
{
int r;
r = check_arg_count(argc, 1);
if (r)
return r;
(void) commit(pool);
r = dm_pool_reserve_metadata_snap(pool->pmd);
if (r)
DMWARN("reserve_metadata_snap message failed.");
return r;
}
static int process_release_metadata_snap_mesg(unsigned int argc, char **argv, struct pool *pool)
{
int r;
r = check_arg_count(argc, 1);
if (r)
return r;
r = dm_pool_release_metadata_snap(pool->pmd);
if (r)
DMWARN("release_metadata_snap message failed.");
return r;
}
/*
* Messages supported:
* create_thin <dev_id>
* create_snap <dev_id> <origin_id>
* delete <dev_id>
* set_transaction_id <current_trans_id> <new_trans_id>
* reserve_metadata_snap
* release_metadata_snap
*/
static int pool_message(struct dm_target *ti, unsigned int argc, char **argv,
char *result, unsigned int maxlen)
{
int r = -EINVAL;
struct pool_c *pt = ti->private;
struct pool *pool = pt->pool;
if (get_pool_mode(pool) >= PM_OUT_OF_METADATA_SPACE) {
DMERR("%s: unable to service pool target messages in READ_ONLY or FAIL mode",
dm_device_name(pool->pool_md));
return -EOPNOTSUPP;
}
if (!strcasecmp(argv[0], "create_thin"))
r = process_create_thin_mesg(argc, argv, pool);
else if (!strcasecmp(argv[0], "create_snap"))
r = process_create_snap_mesg(argc, argv, pool);
else if (!strcasecmp(argv[0], "delete"))
r = process_delete_mesg(argc, argv, pool);
else if (!strcasecmp(argv[0], "set_transaction_id"))
r = process_set_transaction_id_mesg(argc, argv, pool);
else if (!strcasecmp(argv[0], "reserve_metadata_snap"))
r = process_reserve_metadata_snap_mesg(argc, argv, pool);
else if (!strcasecmp(argv[0], "release_metadata_snap"))
r = process_release_metadata_snap_mesg(argc, argv, pool);
else
DMWARN("Unrecognised thin pool target message received: %s", argv[0]);
if (!r)
(void) commit(pool);
return r;
}
static void emit_flags(struct pool_features *pf, char *result,
unsigned int sz, unsigned int maxlen)
{
unsigned int count = !pf->zero_new_blocks + !pf->discard_enabled +
!pf->discard_passdown + (pf->mode == PM_READ_ONLY) +
pf->error_if_no_space;
DMEMIT("%u ", count);
if (!pf->zero_new_blocks)
DMEMIT("skip_block_zeroing ");
if (!pf->discard_enabled)
DMEMIT("ignore_discard ");
if (!pf->discard_passdown)
DMEMIT("no_discard_passdown ");
if (pf->mode == PM_READ_ONLY)
DMEMIT("read_only ");
if (pf->error_if_no_space)
DMEMIT("error_if_no_space ");
}
/*
* Status line is:
* <transaction id> <used metadata sectors>/<total metadata sectors>
* <used data sectors>/<total data sectors> <held metadata root>
* <pool mode> <discard config> <no space config> <needs_check>
*/
static void pool_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
int r;
unsigned int sz = 0;
uint64_t transaction_id;
dm_block_t nr_free_blocks_data;
dm_block_t nr_free_blocks_metadata;
dm_block_t nr_blocks_data;
dm_block_t nr_blocks_metadata;
dm_block_t held_root;
enum pool_mode mode;
char buf[BDEVNAME_SIZE];
char buf2[BDEVNAME_SIZE];
struct pool_c *pt = ti->private;
struct pool *pool = pt->pool;
switch (type) {
case STATUSTYPE_INFO:
if (get_pool_mode(pool) == PM_FAIL) {
DMEMIT("Fail");
break;
}
/* Commit to ensure statistics aren't out-of-date */
if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti))
(void) commit(pool);
r = dm_pool_get_metadata_transaction_id(pool->pmd, &transaction_id);
if (r) {
DMERR("%s: dm_pool_get_metadata_transaction_id returned %d",
dm_device_name(pool->pool_md), r);
goto err;
}
r = dm_pool_get_free_metadata_block_count(pool->pmd, &nr_free_blocks_metadata);
if (r) {
DMERR("%s: dm_pool_get_free_metadata_block_count returned %d",
dm_device_name(pool->pool_md), r);
goto err;
}
r = dm_pool_get_metadata_dev_size(pool->pmd, &nr_blocks_metadata);
if (r) {
DMERR("%s: dm_pool_get_metadata_dev_size returned %d",
dm_device_name(pool->pool_md), r);
goto err;
}
r = dm_pool_get_free_block_count(pool->pmd, &nr_free_blocks_data);
if (r) {
DMERR("%s: dm_pool_get_free_block_count returned %d",
dm_device_name(pool->pool_md), r);
goto err;
}
r = dm_pool_get_data_dev_size(pool->pmd, &nr_blocks_data);
if (r) {
DMERR("%s: dm_pool_get_data_dev_size returned %d",
dm_device_name(pool->pool_md), r);
goto err;
}
r = dm_pool_get_metadata_snap(pool->pmd, &held_root);
if (r) {
DMERR("%s: dm_pool_get_metadata_snap returned %d",
dm_device_name(pool->pool_md), r);
goto err;
}
DMEMIT("%llu %llu/%llu %llu/%llu ",
(unsigned long long)transaction_id,
(unsigned long long)(nr_blocks_metadata - nr_free_blocks_metadata),
(unsigned long long)nr_blocks_metadata,
(unsigned long long)(nr_blocks_data - nr_free_blocks_data),
(unsigned long long)nr_blocks_data);
if (held_root)
DMEMIT("%llu ", held_root);
else
DMEMIT("- ");
mode = get_pool_mode(pool);
if (mode == PM_OUT_OF_DATA_SPACE)
DMEMIT("out_of_data_space ");
else if (is_read_only_pool_mode(mode))
DMEMIT("ro ");
else
DMEMIT("rw ");
if (!pool->pf.discard_enabled)
DMEMIT("ignore_discard ");
else if (pool->pf.discard_passdown)
DMEMIT("discard_passdown ");
else
DMEMIT("no_discard_passdown ");
if (pool->pf.error_if_no_space)
DMEMIT("error_if_no_space ");
else
DMEMIT("queue_if_no_space ");
if (dm_pool_metadata_needs_check(pool->pmd))
DMEMIT("needs_check ");
else
DMEMIT("- ");
DMEMIT("%llu ", (unsigned long long)calc_metadata_threshold(pt));
break;
case STATUSTYPE_TABLE:
DMEMIT("%s %s %lu %llu ",
format_dev_t(buf, pt->metadata_dev->bdev->bd_dev),
format_dev_t(buf2, pt->data_dev->bdev->bd_dev),
(unsigned long)pool->sectors_per_block,
(unsigned long long)pt->low_water_blocks);
emit_flags(&pt->requested_pf, result, sz, maxlen);
break;
case STATUSTYPE_IMA:
*result = '\0';
break;
}
return;
err:
DMEMIT("Error");
}
static int pool_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct pool_c *pt = ti->private;
return fn(ti, pt->data_dev, 0, ti->len, data);
}
static void pool_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
struct pool_c *pt = ti->private;
struct pool *pool = pt->pool;
sector_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT;
/*
* If max_sectors is smaller than pool->sectors_per_block adjust it
* to the highest possible power-of-2 factor of pool->sectors_per_block.
* This is especially beneficial when the pool's data device is a RAID
* device that has a full stripe width that matches pool->sectors_per_block
* -- because even though partial RAID stripe-sized IOs will be issued to a
* single RAID stripe; when aggregated they will end on a full RAID stripe
* boundary.. which avoids additional partial RAID stripe writes cascading
*/
if (limits->max_sectors < pool->sectors_per_block) {
while (!is_factor(pool->sectors_per_block, limits->max_sectors)) {
if ((limits->max_sectors & (limits->max_sectors - 1)) == 0)
limits->max_sectors--;
limits->max_sectors = rounddown_pow_of_two(limits->max_sectors);
}
}
/*
* If the system-determined stacked limits are compatible with the
* pool's blocksize (io_opt is a factor) do not override them.
*/
if (io_opt_sectors < pool->sectors_per_block ||
!is_factor(io_opt_sectors, pool->sectors_per_block)) {
if (is_factor(pool->sectors_per_block, limits->max_sectors))
blk_limits_io_min(limits, limits->max_sectors << SECTOR_SHIFT);
else
blk_limits_io_min(limits, pool->sectors_per_block << SECTOR_SHIFT);
blk_limits_io_opt(limits, pool->sectors_per_block << SECTOR_SHIFT);
}
/*
* pt->adjusted_pf is a staging area for the actual features to use.
* They get transferred to the live pool in bind_control_target()
* called from pool_preresume().
*/
if (pt->adjusted_pf.discard_enabled) {
disable_discard_passdown_if_not_supported(pt);
if (!pt->adjusted_pf.discard_passdown)
limits->max_discard_sectors = 0;
/*
* The pool uses the same discard limits as the underlying data
* device. DM core has already set this up.
*/
} else {
/*
* Must explicitly disallow stacking discard limits otherwise the
* block layer will stack them if pool's data device has support.
*/
limits->discard_granularity = 0;
}
}
static struct target_type pool_target = {
.name = "thin-pool",
.features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE |
DM_TARGET_IMMUTABLE,
.version = {1, 23, 0},
.module = THIS_MODULE,
.ctr = pool_ctr,
.dtr = pool_dtr,
.map = pool_map,
.presuspend = pool_presuspend,
.presuspend_undo = pool_presuspend_undo,
.postsuspend = pool_postsuspend,
.preresume = pool_preresume,
.resume = pool_resume,
.message = pool_message,
.status = pool_status,
.iterate_devices = pool_iterate_devices,
.io_hints = pool_io_hints,
};
/*
*--------------------------------------------------------------
* Thin target methods
*--------------------------------------------------------------
*/
static void thin_get(struct thin_c *tc)
{
refcount_inc(&tc->refcount);
}
static void thin_put(struct thin_c *tc)
{
if (refcount_dec_and_test(&tc->refcount))
complete(&tc->can_destroy);
}
static void thin_dtr(struct dm_target *ti)
{
struct thin_c *tc = ti->private;
spin_lock_irq(&tc->pool->lock);
list_del_rcu(&tc->list);
spin_unlock_irq(&tc->pool->lock);
synchronize_rcu();
thin_put(tc);
wait_for_completion(&tc->can_destroy);
mutex_lock(&dm_thin_pool_table.mutex);
__pool_dec(tc->pool);
dm_pool_close_thin_device(tc->td);
dm_put_device(ti, tc->pool_dev);
if (tc->origin_dev)
dm_put_device(ti, tc->origin_dev);
kfree(tc);
mutex_unlock(&dm_thin_pool_table.mutex);
}
/*
* Thin target parameters:
*
* <pool_dev> <dev_id> [origin_dev]
*
* pool_dev: the path to the pool (eg, /dev/mapper/my_pool)
* dev_id: the internal device identifier
* origin_dev: a device external to the pool that should act as the origin
*
* If the pool device has discards disabled, they get disabled for the thin
* device as well.
*/
static int thin_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
int r;
struct thin_c *tc;
struct dm_dev *pool_dev, *origin_dev;
struct mapped_device *pool_md;
mutex_lock(&dm_thin_pool_table.mutex);
if (argc != 2 && argc != 3) {
ti->error = "Invalid argument count";
r = -EINVAL;
goto out_unlock;
}
tc = ti->private = kzalloc(sizeof(*tc), GFP_KERNEL);
if (!tc) {
ti->error = "Out of memory";
r = -ENOMEM;
goto out_unlock;
}
tc->thin_md = dm_table_get_md(ti->table);
spin_lock_init(&tc->lock);
INIT_LIST_HEAD(&tc->deferred_cells);
bio_list_init(&tc->deferred_bio_list);
bio_list_init(&tc->retry_on_resume_list);
tc->sort_bio_list = RB_ROOT;
if (argc == 3) {
if (!strcmp(argv[0], argv[2])) {
ti->error = "Error setting origin device";
r = -EINVAL;
goto bad_origin_dev;
}
r = dm_get_device(ti, argv[2], BLK_OPEN_READ, &origin_dev);
if (r) {
ti->error = "Error opening origin device";
goto bad_origin_dev;
}
tc->origin_dev = origin_dev;
}
r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &pool_dev);
if (r) {
ti->error = "Error opening pool device";
goto bad_pool_dev;
}
tc->pool_dev = pool_dev;
if (read_dev_id(argv[1], (unsigned long long *)&tc->dev_id, 0)) {
ti->error = "Invalid device id";
r = -EINVAL;
goto bad_common;
}
pool_md = dm_get_md(tc->pool_dev->bdev->bd_dev);
if (!pool_md) {
ti->error = "Couldn't get pool mapped device";
r = -EINVAL;
goto bad_common;
}
tc->pool = __pool_table_lookup(pool_md);
if (!tc->pool) {
ti->error = "Couldn't find pool object";
r = -EINVAL;
goto bad_pool_lookup;
}
__pool_inc(tc->pool);
if (get_pool_mode(tc->pool) == PM_FAIL) {
ti->error = "Couldn't open thin device, Pool is in fail mode";
r = -EINVAL;
goto bad_pool;
}
r = dm_pool_open_thin_device(tc->pool->pmd, tc->dev_id, &tc->td);
if (r) {
ti->error = "Couldn't open thin internal device";
goto bad_pool;
}
r = dm_set_target_max_io_len(ti, tc->pool->sectors_per_block);
if (r)
goto bad;
ti->num_flush_bios = 1;
ti->limit_swap_bios = true;
ti->flush_supported = true;
ti->accounts_remapped_io = true;
ti->per_io_data_size = sizeof(struct dm_thin_endio_hook);
/* In case the pool supports discards, pass them on. */
if (tc->pool->pf.discard_enabled) {
ti->discards_supported = true;
ti->num_discard_bios = 1;
ti->max_discard_granularity = true;
}
mutex_unlock(&dm_thin_pool_table.mutex);
spin_lock_irq(&tc->pool->lock);
if (tc->pool->suspended) {
spin_unlock_irq(&tc->pool->lock);
mutex_lock(&dm_thin_pool_table.mutex); /* reacquire for __pool_dec */
ti->error = "Unable to activate thin device while pool is suspended";
r = -EINVAL;
goto bad;
}
refcount_set(&tc->refcount, 1);
init_completion(&tc->can_destroy);
list_add_tail_rcu(&tc->list, &tc->pool->active_thins);
spin_unlock_irq(&tc->pool->lock);
/*
* This synchronize_rcu() call is needed here otherwise we risk a
* wake_worker() call finding no bios to process (because the newly
* added tc isn't yet visible). So this reduces latency since we
* aren't then dependent on the periodic commit to wake_worker().
*/
synchronize_rcu();
dm_put(pool_md);
return 0;
bad:
dm_pool_close_thin_device(tc->td);
bad_pool:
__pool_dec(tc->pool);
bad_pool_lookup:
dm_put(pool_md);
bad_common:
dm_put_device(ti, tc->pool_dev);
bad_pool_dev:
if (tc->origin_dev)
dm_put_device(ti, tc->origin_dev);
bad_origin_dev:
kfree(tc);
out_unlock:
mutex_unlock(&dm_thin_pool_table.mutex);
return r;
}
static int thin_map(struct dm_target *ti, struct bio *bio)
{
bio->bi_iter.bi_sector = dm_target_offset(ti, bio->bi_iter.bi_sector);
return thin_bio_map(ti, bio);
}
static int thin_endio(struct dm_target *ti, struct bio *bio,
blk_status_t *err)
{
unsigned long flags;
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
struct list_head work;
struct dm_thin_new_mapping *m, *tmp;
struct pool *pool = h->tc->pool;
if (h->shared_read_entry) {
INIT_LIST_HEAD(&work);
dm_deferred_entry_dec(h->shared_read_entry, &work);
spin_lock_irqsave(&pool->lock, flags);
list_for_each_entry_safe(m, tmp, &work, list) {
list_del(&m->list);
__complete_mapping_preparation(m);
}
spin_unlock_irqrestore(&pool->lock, flags);
}
if (h->all_io_entry) {
INIT_LIST_HEAD(&work);
dm_deferred_entry_dec(h->all_io_entry, &work);
if (!list_empty(&work)) {
spin_lock_irqsave(&pool->lock, flags);
list_for_each_entry_safe(m, tmp, &work, list)
list_add_tail(&m->list, &pool->prepared_discards);
spin_unlock_irqrestore(&pool->lock, flags);
wake_worker(pool);
}
}
if (h->cell)
cell_defer_no_holder(h->tc, h->cell);
return DM_ENDIO_DONE;
}
static void thin_presuspend(struct dm_target *ti)
{
struct thin_c *tc = ti->private;
if (dm_noflush_suspending(ti))
noflush_work(tc, do_noflush_start);
}
static void thin_postsuspend(struct dm_target *ti)
{
struct thin_c *tc = ti->private;
/*
* The dm_noflush_suspending flag has been cleared by now, so
* unfortunately we must always run this.
*/
noflush_work(tc, do_noflush_stop);
}
static int thin_preresume(struct dm_target *ti)
{
struct thin_c *tc = ti->private;
if (tc->origin_dev)
tc->origin_size = get_dev_size(tc->origin_dev->bdev);
return 0;
}
/*
* <nr mapped sectors> <highest mapped sector>
*/
static void thin_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
int r;
ssize_t sz = 0;
dm_block_t mapped, highest;
char buf[BDEVNAME_SIZE];
struct thin_c *tc = ti->private;
if (get_pool_mode(tc->pool) == PM_FAIL) {
DMEMIT("Fail");
return;
}
if (!tc->td)
DMEMIT("-");
else {
switch (type) {
case STATUSTYPE_INFO:
r = dm_thin_get_mapped_count(tc->td, &mapped);
if (r) {
DMERR("dm_thin_get_mapped_count returned %d", r);
goto err;
}
r = dm_thin_get_highest_mapped_block(tc->td, &highest);
if (r < 0) {
DMERR("dm_thin_get_highest_mapped_block returned %d", r);
goto err;
}
DMEMIT("%llu ", mapped * tc->pool->sectors_per_block);
if (r)
DMEMIT("%llu", ((highest + 1) *
tc->pool->sectors_per_block) - 1);
else
DMEMIT("-");
break;
case STATUSTYPE_TABLE:
DMEMIT("%s %lu",
format_dev_t(buf, tc->pool_dev->bdev->bd_dev),
(unsigned long) tc->dev_id);
if (tc->origin_dev)
DMEMIT(" %s", format_dev_t(buf, tc->origin_dev->bdev->bd_dev));
break;
case STATUSTYPE_IMA:
*result = '\0';
break;
}
}
return;
err:
DMEMIT("Error");
}
static int thin_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
sector_t blocks;
struct thin_c *tc = ti->private;
struct pool *pool = tc->pool;
/*
* We can't call dm_pool_get_data_dev_size() since that blocks. So
* we follow a more convoluted path through to the pool's target.
*/
if (!pool->ti)
return 0; /* nothing is bound */
blocks = pool->ti->len;
(void) sector_div(blocks, pool->sectors_per_block);
if (blocks)
return fn(ti, tc->pool_dev, 0, pool->sectors_per_block * blocks, data);
return 0;
}
static void thin_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
struct thin_c *tc = ti->private;
struct pool *pool = tc->pool;
if (pool->pf.discard_enabled) {
limits->discard_granularity = pool->sectors_per_block << SECTOR_SHIFT;
limits->max_discard_sectors = pool->sectors_per_block * BIO_PRISON_MAX_RANGE;
}
}
static struct target_type thin_target = {
.name = "thin",
.version = {1, 23, 0},
.module = THIS_MODULE,
.ctr = thin_ctr,
.dtr = thin_dtr,
.map = thin_map,
.end_io = thin_endio,
.preresume = thin_preresume,
.presuspend = thin_presuspend,
.postsuspend = thin_postsuspend,
.status = thin_status,
.iterate_devices = thin_iterate_devices,
.io_hints = thin_io_hints,
};
/*----------------------------------------------------------------*/
static int __init dm_thin_init(void)
{
int r = -ENOMEM;
pool_table_init();
_new_mapping_cache = KMEM_CACHE(dm_thin_new_mapping, 0);
if (!_new_mapping_cache)
return r;
r = dm_register_target(&thin_target);
if (r)
goto bad_new_mapping_cache;
r = dm_register_target(&pool_target);
if (r)
goto bad_thin_target;
return 0;
bad_thin_target:
dm_unregister_target(&thin_target);
bad_new_mapping_cache:
kmem_cache_destroy(_new_mapping_cache);
return r;
}
static void dm_thin_exit(void)
{
dm_unregister_target(&thin_target);
dm_unregister_target(&pool_target);
kmem_cache_destroy(_new_mapping_cache);
pool_table_exit();
}
module_init(dm_thin_init);
module_exit(dm_thin_exit);
module_param_named(no_space_timeout, no_space_timeout_secs, uint, 0644);
MODULE_PARM_DESC(no_space_timeout, "Out of data space queue IO timeout in seconds");
MODULE_DESCRIPTION(DM_NAME " thin provisioning target");
MODULE_AUTHOR("Joe Thornber <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-thin.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2019 Arrikto, Inc. All Rights Reserved.
*/
#include <linux/mm.h>
#include <linux/bio.h>
#include <linux/err.h>
#include <linux/hash.h>
#include <linux/list.h>
#include <linux/log2.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/wait.h>
#include <linux/dm-io.h>
#include <linux/mutex.h>
#include <linux/atomic.h>
#include <linux/bitops.h>
#include <linux/blkdev.h>
#include <linux/kdev_t.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/mempool.h>
#include <linux/spinlock.h>
#include <linux/blk_types.h>
#include <linux/dm-kcopyd.h>
#include <linux/workqueue.h>
#include <linux/backing-dev.h>
#include <linux/device-mapper.h>
#include "dm.h"
#include "dm-clone-metadata.h"
#define DM_MSG_PREFIX "clone"
/*
* Minimum and maximum allowed region sizes
*/
#define MIN_REGION_SIZE (1 << 3) /* 4KB */
#define MAX_REGION_SIZE (1 << 21) /* 1GB */
#define MIN_HYDRATIONS 256 /* Size of hydration mempool */
#define DEFAULT_HYDRATION_THRESHOLD 1 /* 1 region */
#define DEFAULT_HYDRATION_BATCH_SIZE 1 /* Hydrate in batches of 1 region */
#define COMMIT_PERIOD HZ /* 1 sec */
/*
* Hydration hash table size: 1 << HASH_TABLE_BITS
*/
#define HASH_TABLE_BITS 15
DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(clone_hydration_throttle,
"A percentage of time allocated for hydrating regions");
/* Slab cache for struct dm_clone_region_hydration */
static struct kmem_cache *_hydration_cache;
/* dm-clone metadata modes */
enum clone_metadata_mode {
CM_WRITE, /* metadata may be changed */
CM_READ_ONLY, /* metadata may not be changed */
CM_FAIL, /* all metadata I/O fails */
};
struct hash_table_bucket;
struct clone {
struct dm_target *ti;
struct dm_dev *metadata_dev;
struct dm_dev *dest_dev;
struct dm_dev *source_dev;
unsigned long nr_regions;
sector_t region_size;
unsigned int region_shift;
/*
* A metadata commit and the actions taken in case it fails should run
* as a single atomic step.
*/
struct mutex commit_lock;
struct dm_clone_metadata *cmd;
/* Region hydration hash table */
struct hash_table_bucket *ht;
atomic_t ios_in_flight;
wait_queue_head_t hydration_stopped;
mempool_t hydration_pool;
unsigned long last_commit_jiffies;
/*
* We defer incoming WRITE bios for regions that are not hydrated,
* until after these regions have been hydrated.
*
* Also, we defer REQ_FUA and REQ_PREFLUSH bios, until after the
* metadata have been committed.
*/
spinlock_t lock;
struct bio_list deferred_bios;
struct bio_list deferred_discard_bios;
struct bio_list deferred_flush_bios;
struct bio_list deferred_flush_completions;
/* Maximum number of regions being copied during background hydration. */
unsigned int hydration_threshold;
/* Number of regions to batch together during background hydration. */
unsigned int hydration_batch_size;
/* Which region to hydrate next */
unsigned long hydration_offset;
atomic_t hydrations_in_flight;
/*
* Save a copy of the table line rather than reconstructing it for the
* status.
*/
unsigned int nr_ctr_args;
const char **ctr_args;
struct workqueue_struct *wq;
struct work_struct worker;
struct delayed_work waker;
struct dm_kcopyd_client *kcopyd_client;
enum clone_metadata_mode mode;
unsigned long flags;
};
/*
* dm-clone flags
*/
#define DM_CLONE_DISCARD_PASSDOWN 0
#define DM_CLONE_HYDRATION_ENABLED 1
#define DM_CLONE_HYDRATION_SUSPENDED 2
/*---------------------------------------------------------------------------*/
/*
* Metadata failure handling.
*/
static enum clone_metadata_mode get_clone_mode(struct clone *clone)
{
return READ_ONCE(clone->mode);
}
static const char *clone_device_name(struct clone *clone)
{
return dm_table_device_name(clone->ti->table);
}
static void __set_clone_mode(struct clone *clone, enum clone_metadata_mode new_mode)
{
static const char * const descs[] = {
"read-write",
"read-only",
"fail"
};
enum clone_metadata_mode old_mode = get_clone_mode(clone);
/* Never move out of fail mode */
if (old_mode == CM_FAIL)
new_mode = CM_FAIL;
switch (new_mode) {
case CM_FAIL:
case CM_READ_ONLY:
dm_clone_metadata_set_read_only(clone->cmd);
break;
case CM_WRITE:
dm_clone_metadata_set_read_write(clone->cmd);
break;
}
WRITE_ONCE(clone->mode, new_mode);
if (new_mode != old_mode) {
dm_table_event(clone->ti->table);
DMINFO("%s: Switching to %s mode", clone_device_name(clone),
descs[(int)new_mode]);
}
}
static void __abort_transaction(struct clone *clone)
{
const char *dev_name = clone_device_name(clone);
if (get_clone_mode(clone) >= CM_READ_ONLY)
return;
DMERR("%s: Aborting current metadata transaction", dev_name);
if (dm_clone_metadata_abort(clone->cmd)) {
DMERR("%s: Failed to abort metadata transaction", dev_name);
__set_clone_mode(clone, CM_FAIL);
}
}
static void __reload_in_core_bitset(struct clone *clone)
{
const char *dev_name = clone_device_name(clone);
if (get_clone_mode(clone) == CM_FAIL)
return;
/* Reload the on-disk bitset */
DMINFO("%s: Reloading on-disk bitmap", dev_name);
if (dm_clone_reload_in_core_bitset(clone->cmd)) {
DMERR("%s: Failed to reload on-disk bitmap", dev_name);
__set_clone_mode(clone, CM_FAIL);
}
}
static void __metadata_operation_failed(struct clone *clone, const char *op, int r)
{
DMERR("%s: Metadata operation `%s' failed: error = %d",
clone_device_name(clone), op, r);
__abort_transaction(clone);
__set_clone_mode(clone, CM_READ_ONLY);
/*
* dm_clone_reload_in_core_bitset() may run concurrently with either
* dm_clone_set_region_hydrated() or dm_clone_cond_set_range(), but
* it's safe as we have already set the metadata to read-only mode.
*/
__reload_in_core_bitset(clone);
}
/*---------------------------------------------------------------------------*/
/* Wake up anyone waiting for region hydrations to stop */
static inline void wakeup_hydration_waiters(struct clone *clone)
{
wake_up_all(&clone->hydration_stopped);
}
static inline void wake_worker(struct clone *clone)
{
queue_work(clone->wq, &clone->worker);
}
/*---------------------------------------------------------------------------*/
/*
* bio helper functions.
*/
static inline void remap_to_source(struct clone *clone, struct bio *bio)
{
bio_set_dev(bio, clone->source_dev->bdev);
}
static inline void remap_to_dest(struct clone *clone, struct bio *bio)
{
bio_set_dev(bio, clone->dest_dev->bdev);
}
static bool bio_triggers_commit(struct clone *clone, struct bio *bio)
{
return op_is_flush(bio->bi_opf) &&
dm_clone_changed_this_transaction(clone->cmd);
}
/* Get the address of the region in sectors */
static inline sector_t region_to_sector(struct clone *clone, unsigned long region_nr)
{
return ((sector_t)region_nr << clone->region_shift);
}
/* Get the region number of the bio */
static inline unsigned long bio_to_region(struct clone *clone, struct bio *bio)
{
return (bio->bi_iter.bi_sector >> clone->region_shift);
}
/* Get the region range covered by the bio */
static void bio_region_range(struct clone *clone, struct bio *bio,
unsigned long *rs, unsigned long *nr_regions)
{
unsigned long end;
*rs = dm_sector_div_up(bio->bi_iter.bi_sector, clone->region_size);
end = bio_end_sector(bio) >> clone->region_shift;
if (*rs >= end)
*nr_regions = 0;
else
*nr_regions = end - *rs;
}
/* Check whether a bio overwrites a region */
static inline bool is_overwrite_bio(struct clone *clone, struct bio *bio)
{
return (bio_data_dir(bio) == WRITE && bio_sectors(bio) == clone->region_size);
}
static void fail_bios(struct bio_list *bios, blk_status_t status)
{
struct bio *bio;
while ((bio = bio_list_pop(bios))) {
bio->bi_status = status;
bio_endio(bio);
}
}
static void submit_bios(struct bio_list *bios)
{
struct bio *bio;
struct blk_plug plug;
blk_start_plug(&plug);
while ((bio = bio_list_pop(bios)))
submit_bio_noacct(bio);
blk_finish_plug(&plug);
}
/*
* Submit bio to the underlying device.
*
* If the bio triggers a commit, delay it, until after the metadata have been
* committed.
*
* NOTE: The bio remapping must be performed by the caller.
*/
static void issue_bio(struct clone *clone, struct bio *bio)
{
if (!bio_triggers_commit(clone, bio)) {
submit_bio_noacct(bio);
return;
}
/*
* If the metadata mode is RO or FAIL we won't be able to commit the
* metadata, so we complete the bio with an error.
*/
if (unlikely(get_clone_mode(clone) >= CM_READ_ONLY)) {
bio_io_error(bio);
return;
}
/*
* Batch together any bios that trigger commits and then issue a single
* commit for them in process_deferred_flush_bios().
*/
spin_lock_irq(&clone->lock);
bio_list_add(&clone->deferred_flush_bios, bio);
spin_unlock_irq(&clone->lock);
wake_worker(clone);
}
/*
* Remap bio to the destination device and submit it.
*
* If the bio triggers a commit, delay it, until after the metadata have been
* committed.
*/
static void remap_and_issue(struct clone *clone, struct bio *bio)
{
remap_to_dest(clone, bio);
issue_bio(clone, bio);
}
/*
* Issue bios that have been deferred until after their region has finished
* hydrating.
*
* We delegate the bio submission to the worker thread, so this is safe to call
* from interrupt context.
*/
static void issue_deferred_bios(struct clone *clone, struct bio_list *bios)
{
struct bio *bio;
unsigned long flags;
struct bio_list flush_bios = BIO_EMPTY_LIST;
struct bio_list normal_bios = BIO_EMPTY_LIST;
if (bio_list_empty(bios))
return;
while ((bio = bio_list_pop(bios))) {
if (bio_triggers_commit(clone, bio))
bio_list_add(&flush_bios, bio);
else
bio_list_add(&normal_bios, bio);
}
spin_lock_irqsave(&clone->lock, flags);
bio_list_merge(&clone->deferred_bios, &normal_bios);
bio_list_merge(&clone->deferred_flush_bios, &flush_bios);
spin_unlock_irqrestore(&clone->lock, flags);
wake_worker(clone);
}
static void complete_overwrite_bio(struct clone *clone, struct bio *bio)
{
unsigned long flags;
/*
* If the bio has the REQ_FUA flag set we must commit the metadata
* before signaling its completion.
*
* complete_overwrite_bio() is only called by hydration_complete(),
* after having successfully updated the metadata. This means we don't
* need to call dm_clone_changed_this_transaction() to check if the
* metadata has changed and thus we can avoid taking the metadata spin
* lock.
*/
if (!(bio->bi_opf & REQ_FUA)) {
bio_endio(bio);
return;
}
/*
* If the metadata mode is RO or FAIL we won't be able to commit the
* metadata, so we complete the bio with an error.
*/
if (unlikely(get_clone_mode(clone) >= CM_READ_ONLY)) {
bio_io_error(bio);
return;
}
/*
* Batch together any bios that trigger commits and then issue a single
* commit for them in process_deferred_flush_bios().
*/
spin_lock_irqsave(&clone->lock, flags);
bio_list_add(&clone->deferred_flush_completions, bio);
spin_unlock_irqrestore(&clone->lock, flags);
wake_worker(clone);
}
static void trim_bio(struct bio *bio, sector_t sector, unsigned int len)
{
bio->bi_iter.bi_sector = sector;
bio->bi_iter.bi_size = to_bytes(len);
}
static void complete_discard_bio(struct clone *clone, struct bio *bio, bool success)
{
unsigned long rs, nr_regions;
/*
* If the destination device supports discards, remap and trim the
* discard bio and pass it down. Otherwise complete the bio
* immediately.
*/
if (test_bit(DM_CLONE_DISCARD_PASSDOWN, &clone->flags) && success) {
remap_to_dest(clone, bio);
bio_region_range(clone, bio, &rs, &nr_regions);
trim_bio(bio, region_to_sector(clone, rs),
nr_regions << clone->region_shift);
submit_bio_noacct(bio);
} else
bio_endio(bio);
}
static void process_discard_bio(struct clone *clone, struct bio *bio)
{
unsigned long rs, nr_regions;
bio_region_range(clone, bio, &rs, &nr_regions);
if (!nr_regions) {
bio_endio(bio);
return;
}
if (WARN_ON(rs >= clone->nr_regions || (rs + nr_regions) < rs ||
(rs + nr_regions) > clone->nr_regions)) {
DMERR("%s: Invalid range (%lu + %lu, total regions %lu) for discard (%llu + %u)",
clone_device_name(clone), rs, nr_regions,
clone->nr_regions,
(unsigned long long)bio->bi_iter.bi_sector,
bio_sectors(bio));
bio_endio(bio);
return;
}
/*
* The covered regions are already hydrated so we just need to pass
* down the discard.
*/
if (dm_clone_is_range_hydrated(clone->cmd, rs, nr_regions)) {
complete_discard_bio(clone, bio, true);
return;
}
/*
* If the metadata mode is RO or FAIL we won't be able to update the
* metadata for the regions covered by the discard so we just ignore
* it.
*/
if (unlikely(get_clone_mode(clone) >= CM_READ_ONLY)) {
bio_endio(bio);
return;
}
/*
* Defer discard processing.
*/
spin_lock_irq(&clone->lock);
bio_list_add(&clone->deferred_discard_bios, bio);
spin_unlock_irq(&clone->lock);
wake_worker(clone);
}
/*---------------------------------------------------------------------------*/
/*
* dm-clone region hydrations.
*/
struct dm_clone_region_hydration {
struct clone *clone;
unsigned long region_nr;
struct bio *overwrite_bio;
bio_end_io_t *overwrite_bio_end_io;
struct bio_list deferred_bios;
blk_status_t status;
/* Used by hydration batching */
struct list_head list;
/* Used by hydration hash table */
struct hlist_node h;
};
/*
* Hydration hash table implementation.
*
* Ideally we would like to use list_bl, which uses bit spin locks and employs
* the least significant bit of the list head to lock the corresponding bucket,
* reducing the memory overhead for the locks. But, currently, list_bl and bit
* spin locks don't support IRQ safe versions. Since we have to take the lock
* in both process and interrupt context, we must fall back to using regular
* spin locks; one per hash table bucket.
*/
struct hash_table_bucket {
struct hlist_head head;
/* Spinlock protecting the bucket */
spinlock_t lock;
};
#define bucket_lock_irqsave(bucket, flags) \
spin_lock_irqsave(&(bucket)->lock, flags)
#define bucket_unlock_irqrestore(bucket, flags) \
spin_unlock_irqrestore(&(bucket)->lock, flags)
#define bucket_lock_irq(bucket) \
spin_lock_irq(&(bucket)->lock)
#define bucket_unlock_irq(bucket) \
spin_unlock_irq(&(bucket)->lock)
static int hash_table_init(struct clone *clone)
{
unsigned int i, sz;
struct hash_table_bucket *bucket;
sz = 1 << HASH_TABLE_BITS;
clone->ht = kvmalloc_array(sz, sizeof(struct hash_table_bucket), GFP_KERNEL);
if (!clone->ht)
return -ENOMEM;
for (i = 0; i < sz; i++) {
bucket = clone->ht + i;
INIT_HLIST_HEAD(&bucket->head);
spin_lock_init(&bucket->lock);
}
return 0;
}
static void hash_table_exit(struct clone *clone)
{
kvfree(clone->ht);
}
static struct hash_table_bucket *get_hash_table_bucket(struct clone *clone,
unsigned long region_nr)
{
return &clone->ht[hash_long(region_nr, HASH_TABLE_BITS)];
}
/*
* Search hash table for a hydration with hd->region_nr == region_nr
*
* NOTE: Must be called with the bucket lock held
*/
static struct dm_clone_region_hydration *__hash_find(struct hash_table_bucket *bucket,
unsigned long region_nr)
{
struct dm_clone_region_hydration *hd;
hlist_for_each_entry(hd, &bucket->head, h) {
if (hd->region_nr == region_nr)
return hd;
}
return NULL;
}
/*
* Insert a hydration into the hash table.
*
* NOTE: Must be called with the bucket lock held.
*/
static inline void __insert_region_hydration(struct hash_table_bucket *bucket,
struct dm_clone_region_hydration *hd)
{
hlist_add_head(&hd->h, &bucket->head);
}
/*
* This function inserts a hydration into the hash table, unless someone else
* managed to insert a hydration for the same region first. In the latter case
* it returns the existing hydration descriptor for this region.
*
* NOTE: Must be called with the hydration hash table lock held.
*/
static struct dm_clone_region_hydration *
__find_or_insert_region_hydration(struct hash_table_bucket *bucket,
struct dm_clone_region_hydration *hd)
{
struct dm_clone_region_hydration *hd2;
hd2 = __hash_find(bucket, hd->region_nr);
if (hd2)
return hd2;
__insert_region_hydration(bucket, hd);
return hd;
}
/*---------------------------------------------------------------------------*/
/* Allocate a hydration */
static struct dm_clone_region_hydration *alloc_hydration(struct clone *clone)
{
struct dm_clone_region_hydration *hd;
/*
* Allocate a hydration from the hydration mempool.
* This might block but it can't fail.
*/
hd = mempool_alloc(&clone->hydration_pool, GFP_NOIO);
hd->clone = clone;
return hd;
}
static inline void free_hydration(struct dm_clone_region_hydration *hd)
{
mempool_free(hd, &hd->clone->hydration_pool);
}
/* Initialize a hydration */
static void hydration_init(struct dm_clone_region_hydration *hd, unsigned long region_nr)
{
hd->region_nr = region_nr;
hd->overwrite_bio = NULL;
bio_list_init(&hd->deferred_bios);
hd->status = 0;
INIT_LIST_HEAD(&hd->list);
INIT_HLIST_NODE(&hd->h);
}
/*---------------------------------------------------------------------------*/
/*
* Update dm-clone's metadata after a region has finished hydrating and remove
* hydration from the hash table.
*/
static int hydration_update_metadata(struct dm_clone_region_hydration *hd)
{
int r = 0;
unsigned long flags;
struct hash_table_bucket *bucket;
struct clone *clone = hd->clone;
if (unlikely(get_clone_mode(clone) >= CM_READ_ONLY))
r = -EPERM;
/* Update the metadata */
if (likely(!r) && hd->status == BLK_STS_OK)
r = dm_clone_set_region_hydrated(clone->cmd, hd->region_nr);
bucket = get_hash_table_bucket(clone, hd->region_nr);
/* Remove hydration from hash table */
bucket_lock_irqsave(bucket, flags);
hlist_del(&hd->h);
bucket_unlock_irqrestore(bucket, flags);
return r;
}
/*
* Complete a region's hydration:
*
* 1. Update dm-clone's metadata.
* 2. Remove hydration from hash table.
* 3. Complete overwrite bio.
* 4. Issue deferred bios.
* 5. If this was the last hydration, wake up anyone waiting for
* hydrations to finish.
*/
static void hydration_complete(struct dm_clone_region_hydration *hd)
{
int r;
blk_status_t status;
struct clone *clone = hd->clone;
r = hydration_update_metadata(hd);
if (hd->status == BLK_STS_OK && likely(!r)) {
if (hd->overwrite_bio)
complete_overwrite_bio(clone, hd->overwrite_bio);
issue_deferred_bios(clone, &hd->deferred_bios);
} else {
status = r ? BLK_STS_IOERR : hd->status;
if (hd->overwrite_bio)
bio_list_add(&hd->deferred_bios, hd->overwrite_bio);
fail_bios(&hd->deferred_bios, status);
}
free_hydration(hd);
if (atomic_dec_and_test(&clone->hydrations_in_flight))
wakeup_hydration_waiters(clone);
}
static void hydration_kcopyd_callback(int read_err, unsigned long write_err, void *context)
{
blk_status_t status;
struct dm_clone_region_hydration *tmp, *hd = context;
struct clone *clone = hd->clone;
LIST_HEAD(batched_hydrations);
if (read_err || write_err) {
DMERR_LIMIT("%s: hydration failed", clone_device_name(clone));
status = BLK_STS_IOERR;
} else {
status = BLK_STS_OK;
}
list_splice_tail(&hd->list, &batched_hydrations);
hd->status = status;
hydration_complete(hd);
/* Complete batched hydrations */
list_for_each_entry_safe(hd, tmp, &batched_hydrations, list) {
hd->status = status;
hydration_complete(hd);
}
/* Continue background hydration, if there is no I/O in-flight */
if (test_bit(DM_CLONE_HYDRATION_ENABLED, &clone->flags) &&
!atomic_read(&clone->ios_in_flight))
wake_worker(clone);
}
static void hydration_copy(struct dm_clone_region_hydration *hd, unsigned int nr_regions)
{
unsigned long region_start, region_end;
sector_t tail_size, region_size, total_size;
struct dm_io_region from, to;
struct clone *clone = hd->clone;
if (WARN_ON(!nr_regions))
return;
region_size = clone->region_size;
region_start = hd->region_nr;
region_end = region_start + nr_regions - 1;
total_size = region_to_sector(clone, nr_regions - 1);
if (region_end == clone->nr_regions - 1) {
/*
* The last region of the target might be smaller than
* region_size.
*/
tail_size = clone->ti->len & (region_size - 1);
if (!tail_size)
tail_size = region_size;
} else {
tail_size = region_size;
}
total_size += tail_size;
from.bdev = clone->source_dev->bdev;
from.sector = region_to_sector(clone, region_start);
from.count = total_size;
to.bdev = clone->dest_dev->bdev;
to.sector = from.sector;
to.count = from.count;
/* Issue copy */
atomic_add(nr_regions, &clone->hydrations_in_flight);
dm_kcopyd_copy(clone->kcopyd_client, &from, 1, &to, 0,
hydration_kcopyd_callback, hd);
}
static void overwrite_endio(struct bio *bio)
{
struct dm_clone_region_hydration *hd = bio->bi_private;
bio->bi_end_io = hd->overwrite_bio_end_io;
hd->status = bio->bi_status;
hydration_complete(hd);
}
static void hydration_overwrite(struct dm_clone_region_hydration *hd, struct bio *bio)
{
/*
* We don't need to save and restore bio->bi_private because device
* mapper core generates a new bio for us to use, with clean
* bi_private.
*/
hd->overwrite_bio = bio;
hd->overwrite_bio_end_io = bio->bi_end_io;
bio->bi_end_io = overwrite_endio;
bio->bi_private = hd;
atomic_inc(&hd->clone->hydrations_in_flight);
submit_bio_noacct(bio);
}
/*
* Hydrate bio's region.
*
* This function starts the hydration of the bio's region and puts the bio in
* the list of deferred bios for this region. In case, by the time this
* function is called, the region has finished hydrating it's submitted to the
* destination device.
*
* NOTE: The bio remapping must be performed by the caller.
*/
static void hydrate_bio_region(struct clone *clone, struct bio *bio)
{
unsigned long region_nr;
struct hash_table_bucket *bucket;
struct dm_clone_region_hydration *hd, *hd2;
region_nr = bio_to_region(clone, bio);
bucket = get_hash_table_bucket(clone, region_nr);
bucket_lock_irq(bucket);
hd = __hash_find(bucket, region_nr);
if (hd) {
/* Someone else is hydrating the region */
bio_list_add(&hd->deferred_bios, bio);
bucket_unlock_irq(bucket);
return;
}
if (dm_clone_is_region_hydrated(clone->cmd, region_nr)) {
/* The region has been hydrated */
bucket_unlock_irq(bucket);
issue_bio(clone, bio);
return;
}
/*
* We must allocate a hydration descriptor and start the hydration of
* the corresponding region.
*/
bucket_unlock_irq(bucket);
hd = alloc_hydration(clone);
hydration_init(hd, region_nr);
bucket_lock_irq(bucket);
/* Check if the region has been hydrated in the meantime. */
if (dm_clone_is_region_hydrated(clone->cmd, region_nr)) {
bucket_unlock_irq(bucket);
free_hydration(hd);
issue_bio(clone, bio);
return;
}
hd2 = __find_or_insert_region_hydration(bucket, hd);
if (hd2 != hd) {
/* Someone else started the region's hydration. */
bio_list_add(&hd2->deferred_bios, bio);
bucket_unlock_irq(bucket);
free_hydration(hd);
return;
}
/*
* If the metadata mode is RO or FAIL then there is no point starting a
* hydration, since we will not be able to update the metadata when the
* hydration finishes.
*/
if (unlikely(get_clone_mode(clone) >= CM_READ_ONLY)) {
hlist_del(&hd->h);
bucket_unlock_irq(bucket);
free_hydration(hd);
bio_io_error(bio);
return;
}
/*
* Start region hydration.
*
* If a bio overwrites a region, i.e., its size is equal to the
* region's size, then we don't need to copy the region from the source
* to the destination device.
*/
if (is_overwrite_bio(clone, bio)) {
bucket_unlock_irq(bucket);
hydration_overwrite(hd, bio);
} else {
bio_list_add(&hd->deferred_bios, bio);
bucket_unlock_irq(bucket);
hydration_copy(hd, 1);
}
}
/*---------------------------------------------------------------------------*/
/*
* Background hydrations.
*/
/*
* Batch region hydrations.
*
* To better utilize device bandwidth we batch together the hydration of
* adjacent regions. This allows us to use small region sizes, e.g., 4KB, which
* is good for small, random write performance (because of the overwriting of
* un-hydrated regions) and at the same time issue big copy requests to kcopyd
* to achieve high hydration bandwidth.
*/
struct batch_info {
struct dm_clone_region_hydration *head;
unsigned int nr_batched_regions;
};
static void __batch_hydration(struct batch_info *batch,
struct dm_clone_region_hydration *hd)
{
struct clone *clone = hd->clone;
unsigned int max_batch_size = READ_ONCE(clone->hydration_batch_size);
if (batch->head) {
/* Try to extend the current batch */
if (batch->nr_batched_regions < max_batch_size &&
(batch->head->region_nr + batch->nr_batched_regions) == hd->region_nr) {
list_add_tail(&hd->list, &batch->head->list);
batch->nr_batched_regions++;
hd = NULL;
}
/* Check if we should issue the current batch */
if (batch->nr_batched_regions >= max_batch_size || hd) {
hydration_copy(batch->head, batch->nr_batched_regions);
batch->head = NULL;
batch->nr_batched_regions = 0;
}
}
if (!hd)
return;
/* We treat max batch sizes of zero and one equivalently */
if (max_batch_size <= 1) {
hydration_copy(hd, 1);
return;
}
/* Start a new batch */
BUG_ON(!list_empty(&hd->list));
batch->head = hd;
batch->nr_batched_regions = 1;
}
static unsigned long __start_next_hydration(struct clone *clone,
unsigned long offset,
struct batch_info *batch)
{
struct hash_table_bucket *bucket;
struct dm_clone_region_hydration *hd;
unsigned long nr_regions = clone->nr_regions;
hd = alloc_hydration(clone);
/* Try to find a region to hydrate. */
do {
offset = dm_clone_find_next_unhydrated_region(clone->cmd, offset);
if (offset == nr_regions)
break;
bucket = get_hash_table_bucket(clone, offset);
bucket_lock_irq(bucket);
if (!dm_clone_is_region_hydrated(clone->cmd, offset) &&
!__hash_find(bucket, offset)) {
hydration_init(hd, offset);
__insert_region_hydration(bucket, hd);
bucket_unlock_irq(bucket);
/* Batch hydration */
__batch_hydration(batch, hd);
return (offset + 1);
}
bucket_unlock_irq(bucket);
} while (++offset < nr_regions);
if (hd)
free_hydration(hd);
return offset;
}
/*
* This function searches for regions that still reside in the source device
* and starts their hydration.
*/
static void do_hydration(struct clone *clone)
{
unsigned int current_volume;
unsigned long offset, nr_regions = clone->nr_regions;
struct batch_info batch = {
.head = NULL,
.nr_batched_regions = 0,
};
if (unlikely(get_clone_mode(clone) >= CM_READ_ONLY))
return;
if (dm_clone_is_hydration_done(clone->cmd))
return;
/*
* Avoid race with device suspension.
*/
atomic_inc(&clone->hydrations_in_flight);
/*
* Make sure atomic_inc() is ordered before test_bit(), otherwise we
* might race with clone_postsuspend() and start a region hydration
* after the target has been suspended.
*
* This is paired with the smp_mb__after_atomic() in
* clone_postsuspend().
*/
smp_mb__after_atomic();
offset = clone->hydration_offset;
while (likely(!test_bit(DM_CLONE_HYDRATION_SUSPENDED, &clone->flags)) &&
!atomic_read(&clone->ios_in_flight) &&
test_bit(DM_CLONE_HYDRATION_ENABLED, &clone->flags) &&
offset < nr_regions) {
current_volume = atomic_read(&clone->hydrations_in_flight);
current_volume += batch.nr_batched_regions;
if (current_volume > READ_ONCE(clone->hydration_threshold))
break;
offset = __start_next_hydration(clone, offset, &batch);
}
if (batch.head)
hydration_copy(batch.head, batch.nr_batched_regions);
if (offset >= nr_regions)
offset = 0;
clone->hydration_offset = offset;
if (atomic_dec_and_test(&clone->hydrations_in_flight))
wakeup_hydration_waiters(clone);
}
/*---------------------------------------------------------------------------*/
static bool need_commit_due_to_time(struct clone *clone)
{
return !time_in_range(jiffies, clone->last_commit_jiffies,
clone->last_commit_jiffies + COMMIT_PERIOD);
}
/*
* A non-zero return indicates read-only or fail mode.
*/
static int commit_metadata(struct clone *clone, bool *dest_dev_flushed)
{
int r = 0;
if (dest_dev_flushed)
*dest_dev_flushed = false;
mutex_lock(&clone->commit_lock);
if (!dm_clone_changed_this_transaction(clone->cmd))
goto out;
if (unlikely(get_clone_mode(clone) >= CM_READ_ONLY)) {
r = -EPERM;
goto out;
}
r = dm_clone_metadata_pre_commit(clone->cmd);
if (unlikely(r)) {
__metadata_operation_failed(clone, "dm_clone_metadata_pre_commit", r);
goto out;
}
r = blkdev_issue_flush(clone->dest_dev->bdev);
if (unlikely(r)) {
__metadata_operation_failed(clone, "flush destination device", r);
goto out;
}
if (dest_dev_flushed)
*dest_dev_flushed = true;
r = dm_clone_metadata_commit(clone->cmd);
if (unlikely(r)) {
__metadata_operation_failed(clone, "dm_clone_metadata_commit", r);
goto out;
}
if (dm_clone_is_hydration_done(clone->cmd))
dm_table_event(clone->ti->table);
out:
mutex_unlock(&clone->commit_lock);
return r;
}
static void process_deferred_discards(struct clone *clone)
{
int r = -EPERM;
struct bio *bio;
struct blk_plug plug;
unsigned long rs, nr_regions;
struct bio_list discards = BIO_EMPTY_LIST;
spin_lock_irq(&clone->lock);
bio_list_merge(&discards, &clone->deferred_discard_bios);
bio_list_init(&clone->deferred_discard_bios);
spin_unlock_irq(&clone->lock);
if (bio_list_empty(&discards))
return;
if (unlikely(get_clone_mode(clone) >= CM_READ_ONLY))
goto out;
/* Update the metadata */
bio_list_for_each(bio, &discards) {
bio_region_range(clone, bio, &rs, &nr_regions);
/*
* A discard request might cover regions that have been already
* hydrated. There is no need to update the metadata for these
* regions.
*/
r = dm_clone_cond_set_range(clone->cmd, rs, nr_regions);
if (unlikely(r))
break;
}
out:
blk_start_plug(&plug);
while ((bio = bio_list_pop(&discards)))
complete_discard_bio(clone, bio, r == 0);
blk_finish_plug(&plug);
}
static void process_deferred_bios(struct clone *clone)
{
struct bio_list bios = BIO_EMPTY_LIST;
spin_lock_irq(&clone->lock);
bio_list_merge(&bios, &clone->deferred_bios);
bio_list_init(&clone->deferred_bios);
spin_unlock_irq(&clone->lock);
if (bio_list_empty(&bios))
return;
submit_bios(&bios);
}
static void process_deferred_flush_bios(struct clone *clone)
{
struct bio *bio;
bool dest_dev_flushed;
struct bio_list bios = BIO_EMPTY_LIST;
struct bio_list bio_completions = BIO_EMPTY_LIST;
/*
* If there are any deferred flush bios, we must commit the metadata
* before issuing them or signaling their completion.
*/
spin_lock_irq(&clone->lock);
bio_list_merge(&bios, &clone->deferred_flush_bios);
bio_list_init(&clone->deferred_flush_bios);
bio_list_merge(&bio_completions, &clone->deferred_flush_completions);
bio_list_init(&clone->deferred_flush_completions);
spin_unlock_irq(&clone->lock);
if (bio_list_empty(&bios) && bio_list_empty(&bio_completions) &&
!(dm_clone_changed_this_transaction(clone->cmd) && need_commit_due_to_time(clone)))
return;
if (commit_metadata(clone, &dest_dev_flushed)) {
bio_list_merge(&bios, &bio_completions);
while ((bio = bio_list_pop(&bios)))
bio_io_error(bio);
return;
}
clone->last_commit_jiffies = jiffies;
while ((bio = bio_list_pop(&bio_completions)))
bio_endio(bio);
while ((bio = bio_list_pop(&bios))) {
if ((bio->bi_opf & REQ_PREFLUSH) && dest_dev_flushed) {
/* We just flushed the destination device as part of
* the metadata commit, so there is no reason to send
* another flush.
*/
bio_endio(bio);
} else {
submit_bio_noacct(bio);
}
}
}
static void do_worker(struct work_struct *work)
{
struct clone *clone = container_of(work, typeof(*clone), worker);
process_deferred_bios(clone);
process_deferred_discards(clone);
/*
* process_deferred_flush_bios():
*
* - Commit metadata
*
* - Process deferred REQ_FUA completions
*
* - Process deferred REQ_PREFLUSH bios
*/
process_deferred_flush_bios(clone);
/* Background hydration */
do_hydration(clone);
}
/*
* Commit periodically so that not too much unwritten data builds up.
*
* Also, restart background hydration, if it has been stopped by in-flight I/O.
*/
static void do_waker(struct work_struct *work)
{
struct clone *clone = container_of(to_delayed_work(work), struct clone, waker);
wake_worker(clone);
queue_delayed_work(clone->wq, &clone->waker, COMMIT_PERIOD);
}
/*---------------------------------------------------------------------------*/
/*
* Target methods
*/
static int clone_map(struct dm_target *ti, struct bio *bio)
{
struct clone *clone = ti->private;
unsigned long region_nr;
atomic_inc(&clone->ios_in_flight);
if (unlikely(get_clone_mode(clone) == CM_FAIL))
return DM_MAPIO_KILL;
/*
* REQ_PREFLUSH bios carry no data:
*
* - Commit metadata, if changed
*
* - Pass down to destination device
*/
if (bio->bi_opf & REQ_PREFLUSH) {
remap_and_issue(clone, bio);
return DM_MAPIO_SUBMITTED;
}
bio->bi_iter.bi_sector = dm_target_offset(ti, bio->bi_iter.bi_sector);
/*
* dm-clone interprets discards and performs a fast hydration of the
* discarded regions, i.e., we skip the copy from the source device and
* just mark the regions as hydrated.
*/
if (bio_op(bio) == REQ_OP_DISCARD) {
process_discard_bio(clone, bio);
return DM_MAPIO_SUBMITTED;
}
/*
* If the bio's region is hydrated, redirect it to the destination
* device.
*
* If the region is not hydrated and the bio is a READ, redirect it to
* the source device.
*
* Else, defer WRITE bio until after its region has been hydrated and
* start the region's hydration immediately.
*/
region_nr = bio_to_region(clone, bio);
if (dm_clone_is_region_hydrated(clone->cmd, region_nr)) {
remap_and_issue(clone, bio);
return DM_MAPIO_SUBMITTED;
} else if (bio_data_dir(bio) == READ) {
remap_to_source(clone, bio);
return DM_MAPIO_REMAPPED;
}
remap_to_dest(clone, bio);
hydrate_bio_region(clone, bio);
return DM_MAPIO_SUBMITTED;
}
static int clone_endio(struct dm_target *ti, struct bio *bio, blk_status_t *error)
{
struct clone *clone = ti->private;
atomic_dec(&clone->ios_in_flight);
return DM_ENDIO_DONE;
}
static void emit_flags(struct clone *clone, char *result, unsigned int maxlen,
ssize_t *sz_ptr)
{
ssize_t sz = *sz_ptr;
unsigned int count;
count = !test_bit(DM_CLONE_HYDRATION_ENABLED, &clone->flags);
count += !test_bit(DM_CLONE_DISCARD_PASSDOWN, &clone->flags);
DMEMIT("%u ", count);
if (!test_bit(DM_CLONE_HYDRATION_ENABLED, &clone->flags))
DMEMIT("no_hydration ");
if (!test_bit(DM_CLONE_DISCARD_PASSDOWN, &clone->flags))
DMEMIT("no_discard_passdown ");
*sz_ptr = sz;
}
static void emit_core_args(struct clone *clone, char *result,
unsigned int maxlen, ssize_t *sz_ptr)
{
ssize_t sz = *sz_ptr;
unsigned int count = 4;
DMEMIT("%u hydration_threshold %u hydration_batch_size %u ", count,
READ_ONCE(clone->hydration_threshold),
READ_ONCE(clone->hydration_batch_size));
*sz_ptr = sz;
}
/*
* Status format:
*
* <metadata block size> <#used metadata blocks>/<#total metadata blocks>
* <clone region size> <#hydrated regions>/<#total regions> <#hydrating regions>
* <#features> <features>* <#core args> <core args>* <clone metadata mode>
*/
static void clone_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result,
unsigned int maxlen)
{
int r;
unsigned int i;
ssize_t sz = 0;
dm_block_t nr_free_metadata_blocks = 0;
dm_block_t nr_metadata_blocks = 0;
char buf[BDEVNAME_SIZE];
struct clone *clone = ti->private;
switch (type) {
case STATUSTYPE_INFO:
if (get_clone_mode(clone) == CM_FAIL) {
DMEMIT("Fail");
break;
}
/* Commit to ensure statistics aren't out-of-date */
if (!(status_flags & DM_STATUS_NOFLUSH_FLAG) && !dm_suspended(ti))
(void) commit_metadata(clone, NULL);
r = dm_clone_get_free_metadata_block_count(clone->cmd, &nr_free_metadata_blocks);
if (r) {
DMERR("%s: dm_clone_get_free_metadata_block_count returned %d",
clone_device_name(clone), r);
goto error;
}
r = dm_clone_get_metadata_dev_size(clone->cmd, &nr_metadata_blocks);
if (r) {
DMERR("%s: dm_clone_get_metadata_dev_size returned %d",
clone_device_name(clone), r);
goto error;
}
DMEMIT("%u %llu/%llu %llu %u/%lu %u ",
DM_CLONE_METADATA_BLOCK_SIZE,
(unsigned long long)(nr_metadata_blocks - nr_free_metadata_blocks),
(unsigned long long)nr_metadata_blocks,
(unsigned long long)clone->region_size,
dm_clone_nr_of_hydrated_regions(clone->cmd),
clone->nr_regions,
atomic_read(&clone->hydrations_in_flight));
emit_flags(clone, result, maxlen, &sz);
emit_core_args(clone, result, maxlen, &sz);
switch (get_clone_mode(clone)) {
case CM_WRITE:
DMEMIT("rw");
break;
case CM_READ_ONLY:
DMEMIT("ro");
break;
case CM_FAIL:
DMEMIT("Fail");
}
break;
case STATUSTYPE_TABLE:
format_dev_t(buf, clone->metadata_dev->bdev->bd_dev);
DMEMIT("%s ", buf);
format_dev_t(buf, clone->dest_dev->bdev->bd_dev);
DMEMIT("%s ", buf);
format_dev_t(buf, clone->source_dev->bdev->bd_dev);
DMEMIT("%s", buf);
for (i = 0; i < clone->nr_ctr_args; i++)
DMEMIT(" %s", clone->ctr_args[i]);
break;
case STATUSTYPE_IMA:
*result = '\0';
break;
}
return;
error:
DMEMIT("Error");
}
static sector_t get_dev_size(struct dm_dev *dev)
{
return bdev_nr_sectors(dev->bdev);
}
/*---------------------------------------------------------------------------*/
/*
* Construct a clone device mapping:
*
* clone <metadata dev> <destination dev> <source dev> <region size>
* [<#feature args> [<feature arg>]* [<#core args> [key value]*]]
*
* metadata dev: Fast device holding the persistent metadata
* destination dev: The destination device, which will become a clone of the
* source device
* source dev: The read-only source device that gets cloned
* region size: dm-clone unit size in sectors
*
* #feature args: Number of feature arguments passed
* feature args: E.g. no_hydration, no_discard_passdown
*
* #core arguments: An even number of core arguments
* core arguments: Key/value pairs for tuning the core
* E.g. 'hydration_threshold 256'
*/
static int parse_feature_args(struct dm_arg_set *as, struct clone *clone)
{
int r;
unsigned int argc;
const char *arg_name;
struct dm_target *ti = clone->ti;
const struct dm_arg args = {
.min = 0,
.max = 2,
.error = "Invalid number of feature arguments"
};
/* No feature arguments supplied */
if (!as->argc)
return 0;
r = dm_read_arg_group(&args, as, &argc, &ti->error);
if (r)
return r;
while (argc) {
arg_name = dm_shift_arg(as);
argc--;
if (!strcasecmp(arg_name, "no_hydration")) {
__clear_bit(DM_CLONE_HYDRATION_ENABLED, &clone->flags);
} else if (!strcasecmp(arg_name, "no_discard_passdown")) {
__clear_bit(DM_CLONE_DISCARD_PASSDOWN, &clone->flags);
} else {
ti->error = "Invalid feature argument";
return -EINVAL;
}
}
return 0;
}
static int parse_core_args(struct dm_arg_set *as, struct clone *clone)
{
int r;
unsigned int argc;
unsigned int value;
const char *arg_name;
struct dm_target *ti = clone->ti;
const struct dm_arg args = {
.min = 0,
.max = 4,
.error = "Invalid number of core arguments"
};
/* Initialize core arguments */
clone->hydration_batch_size = DEFAULT_HYDRATION_BATCH_SIZE;
clone->hydration_threshold = DEFAULT_HYDRATION_THRESHOLD;
/* No core arguments supplied */
if (!as->argc)
return 0;
r = dm_read_arg_group(&args, as, &argc, &ti->error);
if (r)
return r;
if (argc & 1) {
ti->error = "Number of core arguments must be even";
return -EINVAL;
}
while (argc) {
arg_name = dm_shift_arg(as);
argc -= 2;
if (!strcasecmp(arg_name, "hydration_threshold")) {
if (kstrtouint(dm_shift_arg(as), 10, &value)) {
ti->error = "Invalid value for argument `hydration_threshold'";
return -EINVAL;
}
clone->hydration_threshold = value;
} else if (!strcasecmp(arg_name, "hydration_batch_size")) {
if (kstrtouint(dm_shift_arg(as), 10, &value)) {
ti->error = "Invalid value for argument `hydration_batch_size'";
return -EINVAL;
}
clone->hydration_batch_size = value;
} else {
ti->error = "Invalid core argument";
return -EINVAL;
}
}
return 0;
}
static int parse_region_size(struct clone *clone, struct dm_arg_set *as, char **error)
{
int r;
unsigned int region_size;
struct dm_arg arg;
arg.min = MIN_REGION_SIZE;
arg.max = MAX_REGION_SIZE;
arg.error = "Invalid region size";
r = dm_read_arg(&arg, as, ®ion_size, error);
if (r)
return r;
/* Check region size is a power of 2 */
if (!is_power_of_2(region_size)) {
*error = "Region size is not a power of 2";
return -EINVAL;
}
/* Validate the region size against the device logical block size */
if (region_size % (bdev_logical_block_size(clone->source_dev->bdev) >> 9) ||
region_size % (bdev_logical_block_size(clone->dest_dev->bdev) >> 9)) {
*error = "Region size is not a multiple of device logical block size";
return -EINVAL;
}
clone->region_size = region_size;
return 0;
}
static int validate_nr_regions(unsigned long n, char **error)
{
/*
* dm_bitset restricts us to 2^32 regions. test_bit & co. restrict us
* further to 2^31 regions.
*/
if (n > (1UL << 31)) {
*error = "Too many regions. Consider increasing the region size";
return -EINVAL;
}
return 0;
}
static int parse_metadata_dev(struct clone *clone, struct dm_arg_set *as, char **error)
{
int r;
sector_t metadata_dev_size;
r = dm_get_device(clone->ti, dm_shift_arg(as),
BLK_OPEN_READ | BLK_OPEN_WRITE, &clone->metadata_dev);
if (r) {
*error = "Error opening metadata device";
return r;
}
metadata_dev_size = get_dev_size(clone->metadata_dev);
if (metadata_dev_size > DM_CLONE_METADATA_MAX_SECTORS_WARNING)
DMWARN("Metadata device %pg is larger than %u sectors: excess space will not be used.",
clone->metadata_dev->bdev, DM_CLONE_METADATA_MAX_SECTORS);
return 0;
}
static int parse_dest_dev(struct clone *clone, struct dm_arg_set *as, char **error)
{
int r;
sector_t dest_dev_size;
r = dm_get_device(clone->ti, dm_shift_arg(as),
BLK_OPEN_READ | BLK_OPEN_WRITE, &clone->dest_dev);
if (r) {
*error = "Error opening destination device";
return r;
}
dest_dev_size = get_dev_size(clone->dest_dev);
if (dest_dev_size < clone->ti->len) {
dm_put_device(clone->ti, clone->dest_dev);
*error = "Device size larger than destination device";
return -EINVAL;
}
return 0;
}
static int parse_source_dev(struct clone *clone, struct dm_arg_set *as, char **error)
{
int r;
sector_t source_dev_size;
r = dm_get_device(clone->ti, dm_shift_arg(as), BLK_OPEN_READ,
&clone->source_dev);
if (r) {
*error = "Error opening source device";
return r;
}
source_dev_size = get_dev_size(clone->source_dev);
if (source_dev_size < clone->ti->len) {
dm_put_device(clone->ti, clone->source_dev);
*error = "Device size larger than source device";
return -EINVAL;
}
return 0;
}
static int copy_ctr_args(struct clone *clone, int argc, const char **argv, char **error)
{
unsigned int i;
const char **copy;
copy = kcalloc(argc, sizeof(*copy), GFP_KERNEL);
if (!copy)
goto error;
for (i = 0; i < argc; i++) {
copy[i] = kstrdup(argv[i], GFP_KERNEL);
if (!copy[i]) {
while (i--)
kfree(copy[i]);
kfree(copy);
goto error;
}
}
clone->nr_ctr_args = argc;
clone->ctr_args = copy;
return 0;
error:
*error = "Failed to allocate memory for table line";
return -ENOMEM;
}
static int clone_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
int r;
sector_t nr_regions;
struct clone *clone;
struct dm_arg_set as;
if (argc < 4) {
ti->error = "Invalid number of arguments";
return -EINVAL;
}
as.argc = argc;
as.argv = argv;
clone = kzalloc(sizeof(*clone), GFP_KERNEL);
if (!clone) {
ti->error = "Failed to allocate clone structure";
return -ENOMEM;
}
clone->ti = ti;
/* Initialize dm-clone flags */
__set_bit(DM_CLONE_HYDRATION_ENABLED, &clone->flags);
__set_bit(DM_CLONE_HYDRATION_SUSPENDED, &clone->flags);
__set_bit(DM_CLONE_DISCARD_PASSDOWN, &clone->flags);
r = parse_metadata_dev(clone, &as, &ti->error);
if (r)
goto out_with_clone;
r = parse_dest_dev(clone, &as, &ti->error);
if (r)
goto out_with_meta_dev;
r = parse_source_dev(clone, &as, &ti->error);
if (r)
goto out_with_dest_dev;
r = parse_region_size(clone, &as, &ti->error);
if (r)
goto out_with_source_dev;
clone->region_shift = __ffs(clone->region_size);
nr_regions = dm_sector_div_up(ti->len, clone->region_size);
/* Check for overflow */
if (nr_regions != (unsigned long)nr_regions) {
ti->error = "Too many regions. Consider increasing the region size";
r = -EOVERFLOW;
goto out_with_source_dev;
}
clone->nr_regions = nr_regions;
r = validate_nr_regions(clone->nr_regions, &ti->error);
if (r)
goto out_with_source_dev;
r = dm_set_target_max_io_len(ti, clone->region_size);
if (r) {
ti->error = "Failed to set max io len";
goto out_with_source_dev;
}
r = parse_feature_args(&as, clone);
if (r)
goto out_with_source_dev;
r = parse_core_args(&as, clone);
if (r)
goto out_with_source_dev;
/* Load metadata */
clone->cmd = dm_clone_metadata_open(clone->metadata_dev->bdev, ti->len,
clone->region_size);
if (IS_ERR(clone->cmd)) {
ti->error = "Failed to load metadata";
r = PTR_ERR(clone->cmd);
goto out_with_source_dev;
}
__set_clone_mode(clone, CM_WRITE);
if (get_clone_mode(clone) != CM_WRITE) {
ti->error = "Unable to get write access to metadata, please check/repair metadata";
r = -EPERM;
goto out_with_metadata;
}
clone->last_commit_jiffies = jiffies;
/* Allocate hydration hash table */
r = hash_table_init(clone);
if (r) {
ti->error = "Failed to allocate hydration hash table";
goto out_with_metadata;
}
atomic_set(&clone->ios_in_flight, 0);
init_waitqueue_head(&clone->hydration_stopped);
spin_lock_init(&clone->lock);
bio_list_init(&clone->deferred_bios);
bio_list_init(&clone->deferred_discard_bios);
bio_list_init(&clone->deferred_flush_bios);
bio_list_init(&clone->deferred_flush_completions);
clone->hydration_offset = 0;
atomic_set(&clone->hydrations_in_flight, 0);
clone->wq = alloc_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM, 0);
if (!clone->wq) {
ti->error = "Failed to allocate workqueue";
r = -ENOMEM;
goto out_with_ht;
}
INIT_WORK(&clone->worker, do_worker);
INIT_DELAYED_WORK(&clone->waker, do_waker);
clone->kcopyd_client = dm_kcopyd_client_create(&dm_kcopyd_throttle);
if (IS_ERR(clone->kcopyd_client)) {
r = PTR_ERR(clone->kcopyd_client);
goto out_with_wq;
}
r = mempool_init_slab_pool(&clone->hydration_pool, MIN_HYDRATIONS,
_hydration_cache);
if (r) {
ti->error = "Failed to create dm_clone_region_hydration memory pool";
goto out_with_kcopyd;
}
/* Save a copy of the table line */
r = copy_ctr_args(clone, argc - 3, (const char **)argv + 3, &ti->error);
if (r)
goto out_with_mempool;
mutex_init(&clone->commit_lock);
/* Enable flushes */
ti->num_flush_bios = 1;
ti->flush_supported = true;
/* Enable discards */
ti->discards_supported = true;
ti->num_discard_bios = 1;
ti->private = clone;
return 0;
out_with_mempool:
mempool_exit(&clone->hydration_pool);
out_with_kcopyd:
dm_kcopyd_client_destroy(clone->kcopyd_client);
out_with_wq:
destroy_workqueue(clone->wq);
out_with_ht:
hash_table_exit(clone);
out_with_metadata:
dm_clone_metadata_close(clone->cmd);
out_with_source_dev:
dm_put_device(ti, clone->source_dev);
out_with_dest_dev:
dm_put_device(ti, clone->dest_dev);
out_with_meta_dev:
dm_put_device(ti, clone->metadata_dev);
out_with_clone:
kfree(clone);
return r;
}
static void clone_dtr(struct dm_target *ti)
{
unsigned int i;
struct clone *clone = ti->private;
mutex_destroy(&clone->commit_lock);
for (i = 0; i < clone->nr_ctr_args; i++)
kfree(clone->ctr_args[i]);
kfree(clone->ctr_args);
mempool_exit(&clone->hydration_pool);
dm_kcopyd_client_destroy(clone->kcopyd_client);
cancel_delayed_work_sync(&clone->waker);
destroy_workqueue(clone->wq);
hash_table_exit(clone);
dm_clone_metadata_close(clone->cmd);
dm_put_device(ti, clone->source_dev);
dm_put_device(ti, clone->dest_dev);
dm_put_device(ti, clone->metadata_dev);
kfree(clone);
}
/*---------------------------------------------------------------------------*/
static void clone_postsuspend(struct dm_target *ti)
{
struct clone *clone = ti->private;
/*
* To successfully suspend the device:
*
* - We cancel the delayed work for periodic commits and wait for
* it to finish.
*
* - We stop the background hydration, i.e. we prevent new region
* hydrations from starting.
*
* - We wait for any in-flight hydrations to finish.
*
* - We flush the workqueue.
*
* - We commit the metadata.
*/
cancel_delayed_work_sync(&clone->waker);
set_bit(DM_CLONE_HYDRATION_SUSPENDED, &clone->flags);
/*
* Make sure set_bit() is ordered before atomic_read(), otherwise we
* might race with do_hydration() and miss some started region
* hydrations.
*
* This is paired with smp_mb__after_atomic() in do_hydration().
*/
smp_mb__after_atomic();
wait_event(clone->hydration_stopped, !atomic_read(&clone->hydrations_in_flight));
flush_workqueue(clone->wq);
(void) commit_metadata(clone, NULL);
}
static void clone_resume(struct dm_target *ti)
{
struct clone *clone = ti->private;
clear_bit(DM_CLONE_HYDRATION_SUSPENDED, &clone->flags);
do_waker(&clone->waker.work);
}
/*
* If discard_passdown was enabled verify that the destination device supports
* discards. Disable discard_passdown if not.
*/
static void disable_passdown_if_not_supported(struct clone *clone)
{
struct block_device *dest_dev = clone->dest_dev->bdev;
struct queue_limits *dest_limits = &bdev_get_queue(dest_dev)->limits;
const char *reason = NULL;
if (!test_bit(DM_CLONE_DISCARD_PASSDOWN, &clone->flags))
return;
if (!bdev_max_discard_sectors(dest_dev))
reason = "discard unsupported";
else if (dest_limits->max_discard_sectors < clone->region_size)
reason = "max discard sectors smaller than a region";
if (reason) {
DMWARN("Destination device (%pg) %s: Disabling discard passdown.",
dest_dev, reason);
clear_bit(DM_CLONE_DISCARD_PASSDOWN, &clone->flags);
}
}
static void set_discard_limits(struct clone *clone, struct queue_limits *limits)
{
struct block_device *dest_bdev = clone->dest_dev->bdev;
struct queue_limits *dest_limits = &bdev_get_queue(dest_bdev)->limits;
if (!test_bit(DM_CLONE_DISCARD_PASSDOWN, &clone->flags)) {
/* No passdown is done so we set our own virtual limits */
limits->discard_granularity = clone->region_size << SECTOR_SHIFT;
limits->max_discard_sectors = round_down(UINT_MAX >> SECTOR_SHIFT, clone->region_size);
return;
}
/*
* clone_iterate_devices() is stacking both the source and destination
* device limits but discards aren't passed to the source device, so
* inherit destination's limits.
*/
limits->max_discard_sectors = dest_limits->max_discard_sectors;
limits->max_hw_discard_sectors = dest_limits->max_hw_discard_sectors;
limits->discard_granularity = dest_limits->discard_granularity;
limits->discard_alignment = dest_limits->discard_alignment;
limits->discard_misaligned = dest_limits->discard_misaligned;
limits->max_discard_segments = dest_limits->max_discard_segments;
}
static void clone_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
struct clone *clone = ti->private;
u64 io_opt_sectors = limits->io_opt >> SECTOR_SHIFT;
/*
* If the system-determined stacked limits are compatible with
* dm-clone's region size (io_opt is a factor) do not override them.
*/
if (io_opt_sectors < clone->region_size ||
do_div(io_opt_sectors, clone->region_size)) {
blk_limits_io_min(limits, clone->region_size << SECTOR_SHIFT);
blk_limits_io_opt(limits, clone->region_size << SECTOR_SHIFT);
}
disable_passdown_if_not_supported(clone);
set_discard_limits(clone, limits);
}
static int clone_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
int ret;
struct clone *clone = ti->private;
struct dm_dev *dest_dev = clone->dest_dev;
struct dm_dev *source_dev = clone->source_dev;
ret = fn(ti, source_dev, 0, ti->len, data);
if (!ret)
ret = fn(ti, dest_dev, 0, ti->len, data);
return ret;
}
/*
* dm-clone message functions.
*/
static void set_hydration_threshold(struct clone *clone, unsigned int nr_regions)
{
WRITE_ONCE(clone->hydration_threshold, nr_regions);
/*
* If user space sets hydration_threshold to zero then the hydration
* will stop. If at a later time the hydration_threshold is increased
* we must restart the hydration process by waking up the worker.
*/
wake_worker(clone);
}
static void set_hydration_batch_size(struct clone *clone, unsigned int nr_regions)
{
WRITE_ONCE(clone->hydration_batch_size, nr_regions);
}
static void enable_hydration(struct clone *clone)
{
if (!test_and_set_bit(DM_CLONE_HYDRATION_ENABLED, &clone->flags))
wake_worker(clone);
}
static void disable_hydration(struct clone *clone)
{
clear_bit(DM_CLONE_HYDRATION_ENABLED, &clone->flags);
}
static int clone_message(struct dm_target *ti, unsigned int argc, char **argv,
char *result, unsigned int maxlen)
{
struct clone *clone = ti->private;
unsigned int value;
if (!argc)
return -EINVAL;
if (!strcasecmp(argv[0], "enable_hydration")) {
enable_hydration(clone);
return 0;
}
if (!strcasecmp(argv[0], "disable_hydration")) {
disable_hydration(clone);
return 0;
}
if (argc != 2)
return -EINVAL;
if (!strcasecmp(argv[0], "hydration_threshold")) {
if (kstrtouint(argv[1], 10, &value))
return -EINVAL;
set_hydration_threshold(clone, value);
return 0;
}
if (!strcasecmp(argv[0], "hydration_batch_size")) {
if (kstrtouint(argv[1], 10, &value))
return -EINVAL;
set_hydration_batch_size(clone, value);
return 0;
}
DMERR("%s: Unsupported message `%s'", clone_device_name(clone), argv[0]);
return -EINVAL;
}
static struct target_type clone_target = {
.name = "clone",
.version = {1, 0, 0},
.module = THIS_MODULE,
.ctr = clone_ctr,
.dtr = clone_dtr,
.map = clone_map,
.end_io = clone_endio,
.postsuspend = clone_postsuspend,
.resume = clone_resume,
.status = clone_status,
.message = clone_message,
.io_hints = clone_io_hints,
.iterate_devices = clone_iterate_devices,
};
/*---------------------------------------------------------------------------*/
/* Module functions */
static int __init dm_clone_init(void)
{
int r;
_hydration_cache = KMEM_CACHE(dm_clone_region_hydration, 0);
if (!_hydration_cache)
return -ENOMEM;
r = dm_register_target(&clone_target);
if (r < 0) {
kmem_cache_destroy(_hydration_cache);
return r;
}
return 0;
}
static void __exit dm_clone_exit(void)
{
dm_unregister_target(&clone_target);
kmem_cache_destroy(_hydration_cache);
_hydration_cache = NULL;
}
/* Module hooks */
module_init(dm_clone_init);
module_exit(dm_clone_exit);
MODULE_DESCRIPTION(DM_NAME " clone target");
MODULE_AUTHOR("Nikos Tsironis <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-clone-target.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2018 Red Hat, Inc.
*
* This is a test "dust" device, which fails reads on specified
* sectors, emulating the behavior of a hard disk drive sending
* a "Read Medium Error" sense.
*
*/
#include <linux/device-mapper.h>
#include <linux/module.h>
#include <linux/rbtree.h>
#define DM_MSG_PREFIX "dust"
struct badblock {
struct rb_node node;
sector_t bb;
unsigned char wr_fail_cnt;
};
struct dust_device {
struct dm_dev *dev;
struct rb_root badblocklist;
unsigned long long badblock_count;
spinlock_t dust_lock;
unsigned int blksz;
int sect_per_block_shift;
unsigned int sect_per_block;
sector_t start;
bool fail_read_on_bb:1;
bool quiet_mode:1;
};
static struct badblock *dust_rb_search(struct rb_root *root, sector_t blk)
{
struct rb_node *node = root->rb_node;
while (node) {
struct badblock *bblk = rb_entry(node, struct badblock, node);
if (bblk->bb > blk)
node = node->rb_left;
else if (bblk->bb < blk)
node = node->rb_right;
else
return bblk;
}
return NULL;
}
static bool dust_rb_insert(struct rb_root *root, struct badblock *new)
{
struct badblock *bblk;
struct rb_node **link = &root->rb_node, *parent = NULL;
sector_t value = new->bb;
while (*link) {
parent = *link;
bblk = rb_entry(parent, struct badblock, node);
if (bblk->bb > value)
link = &(*link)->rb_left;
else if (bblk->bb < value)
link = &(*link)->rb_right;
else
return false;
}
rb_link_node(&new->node, parent, link);
rb_insert_color(&new->node, root);
return true;
}
static int dust_remove_block(struct dust_device *dd, unsigned long long block)
{
struct badblock *bblock;
unsigned long flags;
spin_lock_irqsave(&dd->dust_lock, flags);
bblock = dust_rb_search(&dd->badblocklist, block);
if (bblock == NULL) {
if (!dd->quiet_mode) {
DMERR("%s: block %llu not found in badblocklist",
__func__, block);
}
spin_unlock_irqrestore(&dd->dust_lock, flags);
return -EINVAL;
}
rb_erase(&bblock->node, &dd->badblocklist);
dd->badblock_count--;
if (!dd->quiet_mode)
DMINFO("%s: badblock removed at block %llu", __func__, block);
kfree(bblock);
spin_unlock_irqrestore(&dd->dust_lock, flags);
return 0;
}
static int dust_add_block(struct dust_device *dd, unsigned long long block,
unsigned char wr_fail_cnt)
{
struct badblock *bblock;
unsigned long flags;
bblock = kmalloc(sizeof(*bblock), GFP_KERNEL);
if (bblock == NULL) {
if (!dd->quiet_mode)
DMERR("%s: badblock allocation failed", __func__);
return -ENOMEM;
}
spin_lock_irqsave(&dd->dust_lock, flags);
bblock->bb = block;
bblock->wr_fail_cnt = wr_fail_cnt;
if (!dust_rb_insert(&dd->badblocklist, bblock)) {
if (!dd->quiet_mode) {
DMERR("%s: block %llu already in badblocklist",
__func__, block);
}
spin_unlock_irqrestore(&dd->dust_lock, flags);
kfree(bblock);
return -EINVAL;
}
dd->badblock_count++;
if (!dd->quiet_mode) {
DMINFO("%s: badblock added at block %llu with write fail count %u",
__func__, block, wr_fail_cnt);
}
spin_unlock_irqrestore(&dd->dust_lock, flags);
return 0;
}
static int dust_query_block(struct dust_device *dd, unsigned long long block, char *result,
unsigned int maxlen, unsigned int *sz_ptr)
{
struct badblock *bblock;
unsigned long flags;
unsigned int sz = *sz_ptr;
spin_lock_irqsave(&dd->dust_lock, flags);
bblock = dust_rb_search(&dd->badblocklist, block);
if (bblock != NULL)
DMEMIT("%s: block %llu found in badblocklist", __func__, block);
else
DMEMIT("%s: block %llu not found in badblocklist", __func__, block);
spin_unlock_irqrestore(&dd->dust_lock, flags);
return 1;
}
static int __dust_map_read(struct dust_device *dd, sector_t thisblock)
{
struct badblock *bblk = dust_rb_search(&dd->badblocklist, thisblock);
if (bblk)
return DM_MAPIO_KILL;
return DM_MAPIO_REMAPPED;
}
static int dust_map_read(struct dust_device *dd, sector_t thisblock,
bool fail_read_on_bb)
{
unsigned long flags;
int r = DM_MAPIO_REMAPPED;
if (fail_read_on_bb) {
thisblock >>= dd->sect_per_block_shift;
spin_lock_irqsave(&dd->dust_lock, flags);
r = __dust_map_read(dd, thisblock);
spin_unlock_irqrestore(&dd->dust_lock, flags);
}
return r;
}
static int __dust_map_write(struct dust_device *dd, sector_t thisblock)
{
struct badblock *bblk = dust_rb_search(&dd->badblocklist, thisblock);
if (bblk && bblk->wr_fail_cnt > 0) {
bblk->wr_fail_cnt--;
return DM_MAPIO_KILL;
}
if (bblk) {
rb_erase(&bblk->node, &dd->badblocklist);
dd->badblock_count--;
kfree(bblk);
if (!dd->quiet_mode) {
sector_div(thisblock, dd->sect_per_block);
DMINFO("block %llu removed from badblocklist by write",
(unsigned long long)thisblock);
}
}
return DM_MAPIO_REMAPPED;
}
static int dust_map_write(struct dust_device *dd, sector_t thisblock,
bool fail_read_on_bb)
{
unsigned long flags;
int r = DM_MAPIO_REMAPPED;
if (fail_read_on_bb) {
thisblock >>= dd->sect_per_block_shift;
spin_lock_irqsave(&dd->dust_lock, flags);
r = __dust_map_write(dd, thisblock);
spin_unlock_irqrestore(&dd->dust_lock, flags);
}
return r;
}
static int dust_map(struct dm_target *ti, struct bio *bio)
{
struct dust_device *dd = ti->private;
int r;
bio_set_dev(bio, dd->dev->bdev);
bio->bi_iter.bi_sector = dd->start + dm_target_offset(ti, bio->bi_iter.bi_sector);
if (bio_data_dir(bio) == READ)
r = dust_map_read(dd, bio->bi_iter.bi_sector, dd->fail_read_on_bb);
else
r = dust_map_write(dd, bio->bi_iter.bi_sector, dd->fail_read_on_bb);
return r;
}
static bool __dust_clear_badblocks(struct rb_root *tree,
unsigned long long count)
{
struct rb_node *node = NULL, *nnode = NULL;
nnode = rb_first(tree);
if (nnode == NULL) {
BUG_ON(count != 0);
return false;
}
while (nnode) {
node = nnode;
nnode = rb_next(node);
rb_erase(node, tree);
count--;
kfree(node);
}
BUG_ON(count != 0);
BUG_ON(tree->rb_node != NULL);
return true;
}
static int dust_clear_badblocks(struct dust_device *dd, char *result, unsigned int maxlen,
unsigned int *sz_ptr)
{
unsigned long flags;
struct rb_root badblocklist;
unsigned long long badblock_count;
unsigned int sz = *sz_ptr;
spin_lock_irqsave(&dd->dust_lock, flags);
badblocklist = dd->badblocklist;
badblock_count = dd->badblock_count;
dd->badblocklist = RB_ROOT;
dd->badblock_count = 0;
spin_unlock_irqrestore(&dd->dust_lock, flags);
if (!__dust_clear_badblocks(&badblocklist, badblock_count))
DMEMIT("%s: no badblocks found", __func__);
else
DMEMIT("%s: badblocks cleared", __func__);
return 1;
}
static int dust_list_badblocks(struct dust_device *dd, char *result, unsigned int maxlen,
unsigned int *sz_ptr)
{
unsigned long flags;
struct rb_root badblocklist;
struct rb_node *node;
struct badblock *bblk;
unsigned int sz = *sz_ptr;
unsigned long long num = 0;
spin_lock_irqsave(&dd->dust_lock, flags);
badblocklist = dd->badblocklist;
for (node = rb_first(&badblocklist); node; node = rb_next(node)) {
bblk = rb_entry(node, struct badblock, node);
DMEMIT("%llu\n", bblk->bb);
num++;
}
spin_unlock_irqrestore(&dd->dust_lock, flags);
if (!num)
DMEMIT("No blocks in badblocklist");
return 1;
}
/*
* Target parameters:
*
* <device_path> <offset> <blksz>
*
* device_path: path to the block device
* offset: offset to data area from start of device_path
* blksz: block size (minimum 512, maximum 1073741824, must be a power of 2)
*/
static int dust_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
struct dust_device *dd;
unsigned long long tmp;
char dummy;
unsigned int blksz;
unsigned int sect_per_block;
sector_t DUST_MAX_BLKSZ_SECTORS = 2097152;
sector_t max_block_sectors = min(ti->len, DUST_MAX_BLKSZ_SECTORS);
if (argc != 3) {
ti->error = "Invalid argument count";
return -EINVAL;
}
if (kstrtouint(argv[2], 10, &blksz) || !blksz) {
ti->error = "Invalid block size parameter";
return -EINVAL;
}
if (blksz < 512) {
ti->error = "Block size must be at least 512";
return -EINVAL;
}
if (!is_power_of_2(blksz)) {
ti->error = "Block size must be a power of 2";
return -EINVAL;
}
if (to_sector(blksz) > max_block_sectors) {
ti->error = "Block size is too large";
return -EINVAL;
}
sect_per_block = (blksz >> SECTOR_SHIFT);
if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1 || tmp != (sector_t)tmp) {
ti->error = "Invalid device offset sector";
return -EINVAL;
}
dd = kzalloc(sizeof(struct dust_device), GFP_KERNEL);
if (dd == NULL) {
ti->error = "Cannot allocate context";
return -ENOMEM;
}
if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &dd->dev)) {
ti->error = "Device lookup failed";
kfree(dd);
return -EINVAL;
}
dd->sect_per_block = sect_per_block;
dd->blksz = blksz;
dd->start = tmp;
dd->sect_per_block_shift = __ffs(sect_per_block);
/*
* Whether to fail a read on a "bad" block.
* Defaults to false; enabled later by message.
*/
dd->fail_read_on_bb = false;
/*
* Initialize bad block list rbtree.
*/
dd->badblocklist = RB_ROOT;
dd->badblock_count = 0;
spin_lock_init(&dd->dust_lock);
dd->quiet_mode = false;
BUG_ON(dm_set_target_max_io_len(ti, dd->sect_per_block) != 0);
ti->num_discard_bios = 1;
ti->num_flush_bios = 1;
ti->private = dd;
return 0;
}
static void dust_dtr(struct dm_target *ti)
{
struct dust_device *dd = ti->private;
__dust_clear_badblocks(&dd->badblocklist, dd->badblock_count);
dm_put_device(ti, dd->dev);
kfree(dd);
}
static int dust_message(struct dm_target *ti, unsigned int argc, char **argv,
char *result, unsigned int maxlen)
{
struct dust_device *dd = ti->private;
sector_t size = bdev_nr_sectors(dd->dev->bdev);
bool invalid_msg = false;
int r = -EINVAL;
unsigned long long tmp, block;
unsigned char wr_fail_cnt;
unsigned int tmp_ui;
unsigned long flags;
unsigned int sz = 0;
char dummy;
if (argc == 1) {
if (!strcasecmp(argv[0], "addbadblock") ||
!strcasecmp(argv[0], "removebadblock") ||
!strcasecmp(argv[0], "queryblock")) {
DMERR("%s requires an additional argument", argv[0]);
} else if (!strcasecmp(argv[0], "disable")) {
DMINFO("disabling read failures on bad sectors");
dd->fail_read_on_bb = false;
r = 0;
} else if (!strcasecmp(argv[0], "enable")) {
DMINFO("enabling read failures on bad sectors");
dd->fail_read_on_bb = true;
r = 0;
} else if (!strcasecmp(argv[0], "countbadblocks")) {
spin_lock_irqsave(&dd->dust_lock, flags);
DMEMIT("countbadblocks: %llu badblock(s) found",
dd->badblock_count);
spin_unlock_irqrestore(&dd->dust_lock, flags);
r = 1;
} else if (!strcasecmp(argv[0], "clearbadblocks")) {
r = dust_clear_badblocks(dd, result, maxlen, &sz);
} else if (!strcasecmp(argv[0], "quiet")) {
if (!dd->quiet_mode)
dd->quiet_mode = true;
else
dd->quiet_mode = false;
r = 0;
} else if (!strcasecmp(argv[0], "listbadblocks")) {
r = dust_list_badblocks(dd, result, maxlen, &sz);
} else {
invalid_msg = true;
}
} else if (argc == 2) {
if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1)
return r;
block = tmp;
sector_div(size, dd->sect_per_block);
if (block > size) {
DMERR("selected block value out of range");
return r;
}
if (!strcasecmp(argv[0], "addbadblock"))
r = dust_add_block(dd, block, 0);
else if (!strcasecmp(argv[0], "removebadblock"))
r = dust_remove_block(dd, block);
else if (!strcasecmp(argv[0], "queryblock"))
r = dust_query_block(dd, block, result, maxlen, &sz);
else
invalid_msg = true;
} else if (argc == 3) {
if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1)
return r;
if (sscanf(argv[2], "%u%c", &tmp_ui, &dummy) != 1)
return r;
block = tmp;
if (tmp_ui > 255) {
DMERR("selected write fail count out of range");
return r;
}
wr_fail_cnt = tmp_ui;
sector_div(size, dd->sect_per_block);
if (block > size) {
DMERR("selected block value out of range");
return r;
}
if (!strcasecmp(argv[0], "addbadblock"))
r = dust_add_block(dd, block, wr_fail_cnt);
else
invalid_msg = true;
} else
DMERR("invalid number of arguments '%d'", argc);
if (invalid_msg)
DMERR("unrecognized message '%s' received", argv[0]);
return r;
}
static void dust_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
struct dust_device *dd = ti->private;
unsigned int sz = 0;
switch (type) {
case STATUSTYPE_INFO:
DMEMIT("%s %s %s", dd->dev->name,
dd->fail_read_on_bb ? "fail_read_on_bad_block" : "bypass",
dd->quiet_mode ? "quiet" : "verbose");
break;
case STATUSTYPE_TABLE:
DMEMIT("%s %llu %u", dd->dev->name,
(unsigned long long)dd->start, dd->blksz);
break;
case STATUSTYPE_IMA:
*result = '\0';
break;
}
}
static int dust_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
{
struct dust_device *dd = ti->private;
struct dm_dev *dev = dd->dev;
*bdev = dev->bdev;
/*
* Only pass ioctls through if the device sizes match exactly.
*/
if (dd->start || ti->len != bdev_nr_sectors(dev->bdev))
return 1;
return 0;
}
static int dust_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn,
void *data)
{
struct dust_device *dd = ti->private;
return fn(ti, dd->dev, dd->start, ti->len, data);
}
static struct target_type dust_target = {
.name = "dust",
.version = {1, 0, 0},
.module = THIS_MODULE,
.ctr = dust_ctr,
.dtr = dust_dtr,
.iterate_devices = dust_iterate_devices,
.map = dust_map,
.message = dust_message,
.status = dust_status,
.prepare_ioctl = dust_prepare_ioctl,
};
module_dm(dust);
MODULE_DESCRIPTION(DM_NAME " dust test target");
MODULE_AUTHOR("Bryan Gurney <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-dust.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2019 Microsoft Corporation.
*
* Author: Jaskaran Singh Khurana <[email protected]>
*
*/
#include <linux/device-mapper.h>
#include <linux/verification.h>
#include <keys/user-type.h>
#include <linux/module.h>
#include "dm-verity.h"
#include "dm-verity-verify-sig.h"
#define DM_VERITY_VERIFY_ERR(s) DM_VERITY_ROOT_HASH_VERIFICATION " " s
static bool require_signatures;
module_param(require_signatures, bool, 0444);
MODULE_PARM_DESC(require_signatures,
"Verify the roothash of dm-verity hash tree");
#define DM_VERITY_IS_SIG_FORCE_ENABLED() \
(require_signatures != false)
bool verity_verify_is_sig_opt_arg(const char *arg_name)
{
return (!strcasecmp(arg_name,
DM_VERITY_ROOT_HASH_VERIFICATION_OPT_SIG_KEY));
}
static int verity_verify_get_sig_from_key(const char *key_desc,
struct dm_verity_sig_opts *sig_opts)
{
struct key *key;
const struct user_key_payload *ukp;
int ret = 0;
key = request_key(&key_type_user,
key_desc, NULL);
if (IS_ERR(key))
return PTR_ERR(key);
down_read(&key->sem);
ukp = user_key_payload_locked(key);
if (!ukp) {
ret = -EKEYREVOKED;
goto end;
}
sig_opts->sig = kmalloc(ukp->datalen, GFP_KERNEL);
if (!sig_opts->sig) {
ret = -ENOMEM;
goto end;
}
sig_opts->sig_size = ukp->datalen;
memcpy(sig_opts->sig, ukp->data, sig_opts->sig_size);
end:
up_read(&key->sem);
key_put(key);
return ret;
}
int verity_verify_sig_parse_opt_args(struct dm_arg_set *as,
struct dm_verity *v,
struct dm_verity_sig_opts *sig_opts,
unsigned int *argc,
const char *arg_name)
{
struct dm_target *ti = v->ti;
int ret = 0;
const char *sig_key = NULL;
if (!*argc) {
ti->error = DM_VERITY_VERIFY_ERR("Signature key not specified");
return -EINVAL;
}
sig_key = dm_shift_arg(as);
(*argc)--;
ret = verity_verify_get_sig_from_key(sig_key, sig_opts);
if (ret < 0)
ti->error = DM_VERITY_VERIFY_ERR("Invalid key specified");
v->signature_key_desc = kstrdup(sig_key, GFP_KERNEL);
if (!v->signature_key_desc)
return -ENOMEM;
return ret;
}
/*
* verify_verify_roothash - Verify the root hash of the verity hash device
* using builtin trusted keys.
*
* @root_hash: For verity, the roothash/data to be verified.
* @root_hash_len: Size of the roothash/data to be verified.
* @sig_data: The trusted signature that verifies the roothash/data.
* @sig_len: Size of the signature.
*
*/
int verity_verify_root_hash(const void *root_hash, size_t root_hash_len,
const void *sig_data, size_t sig_len)
{
int ret;
if (!root_hash || root_hash_len == 0)
return -EINVAL;
if (!sig_data || sig_len == 0) {
if (DM_VERITY_IS_SIG_FORCE_ENABLED())
return -ENOKEY;
else
return 0;
}
ret = verify_pkcs7_signature(root_hash, root_hash_len, sig_data,
sig_len,
#ifdef CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG_SECONDARY_KEYRING
VERIFY_USE_SECONDARY_KEYRING,
#else
NULL,
#endif
VERIFYING_UNSPECIFIED_SIGNATURE, NULL, NULL);
return ret;
}
void verity_verify_sig_opts_cleanup(struct dm_verity_sig_opts *sig_opts)
{
kfree(sig_opts->sig);
sig_opts->sig = NULL;
sig_opts->sig_size = 0;
}
| linux-master | drivers/md/dm-verity-verify-sig.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2008 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
#include <linux/sysfs.h>
#include <linux/dm-ioctl.h>
#include "dm-core.h"
#include "dm-rq.h"
struct dm_sysfs_attr {
struct attribute attr;
ssize_t (*show)(struct mapped_device *md, char *p);
ssize_t (*store)(struct mapped_device *md, const char *p, size_t count);
};
#define DM_ATTR_RO(_name) \
struct dm_sysfs_attr dm_attr_##_name = \
__ATTR(_name, 0444, dm_attr_##_name##_show, NULL)
static ssize_t dm_attr_show(struct kobject *kobj, struct attribute *attr,
char *page)
{
struct dm_sysfs_attr *dm_attr;
struct mapped_device *md;
ssize_t ret;
dm_attr = container_of(attr, struct dm_sysfs_attr, attr);
if (!dm_attr->show)
return -EIO;
md = dm_get_from_kobject(kobj);
if (!md)
return -EINVAL;
ret = dm_attr->show(md, page);
dm_put(md);
return ret;
}
#define DM_ATTR_RW(_name) \
struct dm_sysfs_attr dm_attr_##_name = \
__ATTR(_name, 0644, dm_attr_##_name##_show, dm_attr_##_name##_store)
static ssize_t dm_attr_store(struct kobject *kobj, struct attribute *attr,
const char *page, size_t count)
{
struct dm_sysfs_attr *dm_attr;
struct mapped_device *md;
ssize_t ret;
dm_attr = container_of(attr, struct dm_sysfs_attr, attr);
if (!dm_attr->store)
return -EIO;
md = dm_get_from_kobject(kobj);
if (!md)
return -EINVAL;
ret = dm_attr->store(md, page, count);
dm_put(md);
return ret;
}
static ssize_t dm_attr_name_show(struct mapped_device *md, char *buf)
{
if (dm_copy_name_and_uuid(md, buf, NULL))
return -EIO;
strcat(buf, "\n");
return strlen(buf);
}
static ssize_t dm_attr_uuid_show(struct mapped_device *md, char *buf)
{
if (dm_copy_name_and_uuid(md, NULL, buf))
return -EIO;
strcat(buf, "\n");
return strlen(buf);
}
static ssize_t dm_attr_suspended_show(struct mapped_device *md, char *buf)
{
sprintf(buf, "%d\n", dm_suspended_md(md));
return strlen(buf);
}
static ssize_t dm_attr_use_blk_mq_show(struct mapped_device *md, char *buf)
{
/* Purely for userspace compatibility */
sprintf(buf, "%d\n", true);
return strlen(buf);
}
static DM_ATTR_RO(name);
static DM_ATTR_RO(uuid);
static DM_ATTR_RO(suspended);
static DM_ATTR_RO(use_blk_mq);
static DM_ATTR_RW(rq_based_seq_io_merge_deadline);
static struct attribute *dm_attrs[] = {
&dm_attr_name.attr,
&dm_attr_uuid.attr,
&dm_attr_suspended.attr,
&dm_attr_use_blk_mq.attr,
&dm_attr_rq_based_seq_io_merge_deadline.attr,
NULL,
};
ATTRIBUTE_GROUPS(dm);
static const struct sysfs_ops dm_sysfs_ops = {
.show = dm_attr_show,
.store = dm_attr_store,
};
static const struct kobj_type dm_ktype = {
.sysfs_ops = &dm_sysfs_ops,
.default_groups = dm_groups,
.release = dm_kobject_release,
};
/*
* Initialize kobj
* because nobody using md yet, no need to call explicit dm_get/put
*/
int dm_sysfs_init(struct mapped_device *md)
{
return kobject_init_and_add(dm_kobject(md), &dm_ktype,
&disk_to_dev(dm_disk(md))->kobj,
"%s", "dm");
}
/*
* Remove kobj, called after all references removed
*/
void dm_sysfs_exit(struct mapped_device *md)
{
struct kobject *kobj = dm_kobject(md);
kobject_put(kobj);
wait_for_completion(dm_get_completion_from_kobject(kobj));
}
| linux-master | drivers/md/dm-sysfs.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2016-2017 Red Hat, Inc. All rights reserved.
* Copyright (C) 2016-2017 Milan Broz
* Copyright (C) 2016-2017 Mikulas Patocka
*
* This file is released under the GPL.
*/
#include "dm-bio-record.h"
#include <linux/compiler.h>
#include <linux/module.h>
#include <linux/device-mapper.h>
#include <linux/dm-io.h>
#include <linux/vmalloc.h>
#include <linux/sort.h>
#include <linux/rbtree.h>
#include <linux/delay.h>
#include <linux/random.h>
#include <linux/reboot.h>
#include <crypto/hash.h>
#include <crypto/skcipher.h>
#include <linux/async_tx.h>
#include <linux/dm-bufio.h>
#include "dm-audit.h"
#define DM_MSG_PREFIX "integrity"
#define DEFAULT_INTERLEAVE_SECTORS 32768
#define DEFAULT_JOURNAL_SIZE_FACTOR 7
#define DEFAULT_SECTORS_PER_BITMAP_BIT 32768
#define DEFAULT_BUFFER_SECTORS 128
#define DEFAULT_JOURNAL_WATERMARK 50
#define DEFAULT_SYNC_MSEC 10000
#define DEFAULT_MAX_JOURNAL_SECTORS (IS_ENABLED(CONFIG_64BIT) ? 131072 : 8192)
#define MIN_LOG2_INTERLEAVE_SECTORS 3
#define MAX_LOG2_INTERLEAVE_SECTORS 31
#define METADATA_WORKQUEUE_MAX_ACTIVE 16
#define RECALC_SECTORS (IS_ENABLED(CONFIG_64BIT) ? 32768 : 2048)
#define RECALC_WRITE_SUPER 16
#define BITMAP_BLOCK_SIZE 4096 /* don't change it */
#define BITMAP_FLUSH_INTERVAL (10 * HZ)
#define DISCARD_FILLER 0xf6
#define SALT_SIZE 16
/*
* Warning - DEBUG_PRINT prints security-sensitive data to the log,
* so it should not be enabled in the official kernel
*/
//#define DEBUG_PRINT
//#define INTERNAL_VERIFY
/*
* On disk structures
*/
#define SB_MAGIC "integrt"
#define SB_VERSION_1 1
#define SB_VERSION_2 2
#define SB_VERSION_3 3
#define SB_VERSION_4 4
#define SB_VERSION_5 5
#define SB_SECTORS 8
#define MAX_SECTORS_PER_BLOCK 8
struct superblock {
__u8 magic[8];
__u8 version;
__u8 log2_interleave_sectors;
__le16 integrity_tag_size;
__le32 journal_sections;
__le64 provided_data_sectors; /* userspace uses this value */
__le32 flags;
__u8 log2_sectors_per_block;
__u8 log2_blocks_per_bitmap_bit;
__u8 pad[2];
__le64 recalc_sector;
__u8 pad2[8];
__u8 salt[SALT_SIZE];
};
#define SB_FLAG_HAVE_JOURNAL_MAC 0x1
#define SB_FLAG_RECALCULATING 0x2
#define SB_FLAG_DIRTY_BITMAP 0x4
#define SB_FLAG_FIXED_PADDING 0x8
#define SB_FLAG_FIXED_HMAC 0x10
#define JOURNAL_ENTRY_ROUNDUP 8
typedef __le64 commit_id_t;
#define JOURNAL_MAC_PER_SECTOR 8
struct journal_entry {
union {
struct {
__le32 sector_lo;
__le32 sector_hi;
} s;
__le64 sector;
} u;
commit_id_t last_bytes[];
/* __u8 tag[0]; */
};
#define journal_entry_tag(ic, je) ((__u8 *)&(je)->last_bytes[(ic)->sectors_per_block])
#if BITS_PER_LONG == 64
#define journal_entry_set_sector(je, x) do { smp_wmb(); WRITE_ONCE((je)->u.sector, cpu_to_le64(x)); } while (0)
#else
#define journal_entry_set_sector(je, x) do { (je)->u.s.sector_lo = cpu_to_le32(x); smp_wmb(); WRITE_ONCE((je)->u.s.sector_hi, cpu_to_le32((x) >> 32)); } while (0)
#endif
#define journal_entry_get_sector(je) le64_to_cpu((je)->u.sector)
#define journal_entry_is_unused(je) ((je)->u.s.sector_hi == cpu_to_le32(-1))
#define journal_entry_set_unused(je) ((je)->u.s.sector_hi = cpu_to_le32(-1))
#define journal_entry_is_inprogress(je) ((je)->u.s.sector_hi == cpu_to_le32(-2))
#define journal_entry_set_inprogress(je) ((je)->u.s.sector_hi = cpu_to_le32(-2))
#define JOURNAL_BLOCK_SECTORS 8
#define JOURNAL_SECTOR_DATA ((1 << SECTOR_SHIFT) - sizeof(commit_id_t))
#define JOURNAL_MAC_SIZE (JOURNAL_MAC_PER_SECTOR * JOURNAL_BLOCK_SECTORS)
struct journal_sector {
struct_group(sectors,
__u8 entries[JOURNAL_SECTOR_DATA - JOURNAL_MAC_PER_SECTOR];
__u8 mac[JOURNAL_MAC_PER_SECTOR];
);
commit_id_t commit_id;
};
#define MAX_TAG_SIZE (JOURNAL_SECTOR_DATA - JOURNAL_MAC_PER_SECTOR - offsetof(struct journal_entry, last_bytes[MAX_SECTORS_PER_BLOCK]))
#define METADATA_PADDING_SECTORS 8
#define N_COMMIT_IDS 4
static unsigned char prev_commit_seq(unsigned char seq)
{
return (seq + N_COMMIT_IDS - 1) % N_COMMIT_IDS;
}
static unsigned char next_commit_seq(unsigned char seq)
{
return (seq + 1) % N_COMMIT_IDS;
}
/*
* In-memory structures
*/
struct journal_node {
struct rb_node node;
sector_t sector;
};
struct alg_spec {
char *alg_string;
char *key_string;
__u8 *key;
unsigned int key_size;
};
struct dm_integrity_c {
struct dm_dev *dev;
struct dm_dev *meta_dev;
unsigned int tag_size;
__s8 log2_tag_size;
sector_t start;
mempool_t journal_io_mempool;
struct dm_io_client *io;
struct dm_bufio_client *bufio;
struct workqueue_struct *metadata_wq;
struct superblock *sb;
unsigned int journal_pages;
unsigned int n_bitmap_blocks;
struct page_list *journal;
struct page_list *journal_io;
struct page_list *journal_xor;
struct page_list *recalc_bitmap;
struct page_list *may_write_bitmap;
struct bitmap_block_status *bbs;
unsigned int bitmap_flush_interval;
int synchronous_mode;
struct bio_list synchronous_bios;
struct delayed_work bitmap_flush_work;
struct crypto_skcipher *journal_crypt;
struct scatterlist **journal_scatterlist;
struct scatterlist **journal_io_scatterlist;
struct skcipher_request **sk_requests;
struct crypto_shash *journal_mac;
struct journal_node *journal_tree;
struct rb_root journal_tree_root;
sector_t provided_data_sectors;
unsigned short journal_entry_size;
unsigned char journal_entries_per_sector;
unsigned char journal_section_entries;
unsigned short journal_section_sectors;
unsigned int journal_sections;
unsigned int journal_entries;
sector_t data_device_sectors;
sector_t meta_device_sectors;
unsigned int initial_sectors;
unsigned int metadata_run;
__s8 log2_metadata_run;
__u8 log2_buffer_sectors;
__u8 sectors_per_block;
__u8 log2_blocks_per_bitmap_bit;
unsigned char mode;
int failed;
struct crypto_shash *internal_hash;
struct dm_target *ti;
/* these variables are locked with endio_wait.lock */
struct rb_root in_progress;
struct list_head wait_list;
wait_queue_head_t endio_wait;
struct workqueue_struct *wait_wq;
struct workqueue_struct *offload_wq;
unsigned char commit_seq;
commit_id_t commit_ids[N_COMMIT_IDS];
unsigned int committed_section;
unsigned int n_committed_sections;
unsigned int uncommitted_section;
unsigned int n_uncommitted_sections;
unsigned int free_section;
unsigned char free_section_entry;
unsigned int free_sectors;
unsigned int free_sectors_threshold;
struct workqueue_struct *commit_wq;
struct work_struct commit_work;
struct workqueue_struct *writer_wq;
struct work_struct writer_work;
struct workqueue_struct *recalc_wq;
struct work_struct recalc_work;
struct bio_list flush_bio_list;
unsigned long autocommit_jiffies;
struct timer_list autocommit_timer;
unsigned int autocommit_msec;
wait_queue_head_t copy_to_journal_wait;
struct completion crypto_backoff;
bool wrote_to_journal;
bool journal_uptodate;
bool just_formatted;
bool recalculate_flag;
bool reset_recalculate_flag;
bool discard;
bool fix_padding;
bool fix_hmac;
bool legacy_recalculate;
struct alg_spec internal_hash_alg;
struct alg_spec journal_crypt_alg;
struct alg_spec journal_mac_alg;
atomic64_t number_of_mismatches;
struct notifier_block reboot_notifier;
};
struct dm_integrity_range {
sector_t logical_sector;
sector_t n_sectors;
bool waiting;
union {
struct rb_node node;
struct {
struct task_struct *task;
struct list_head wait_entry;
};
};
};
struct dm_integrity_io {
struct work_struct work;
struct dm_integrity_c *ic;
enum req_op op;
bool fua;
struct dm_integrity_range range;
sector_t metadata_block;
unsigned int metadata_offset;
atomic_t in_flight;
blk_status_t bi_status;
struct completion *completion;
struct dm_bio_details bio_details;
};
struct journal_completion {
struct dm_integrity_c *ic;
atomic_t in_flight;
struct completion comp;
};
struct journal_io {
struct dm_integrity_range range;
struct journal_completion *comp;
};
struct bitmap_block_status {
struct work_struct work;
struct dm_integrity_c *ic;
unsigned int idx;
unsigned long *bitmap;
struct bio_list bio_queue;
spinlock_t bio_queue_lock;
};
static struct kmem_cache *journal_io_cache;
#define JOURNAL_IO_MEMPOOL 32
#ifdef DEBUG_PRINT
#define DEBUG_print(x, ...) printk(KERN_DEBUG x, ##__VA_ARGS__)
#define DEBUG_bytes(bytes, len, msg, ...) printk(KERN_DEBUG msg "%s%*ph\n", ##__VA_ARGS__, \
len ? ": " : "", len, bytes)
#else
#define DEBUG_print(x, ...) do { } while (0)
#define DEBUG_bytes(bytes, len, msg, ...) do { } while (0)
#endif
static void dm_integrity_prepare(struct request *rq)
{
}
static void dm_integrity_complete(struct request *rq, unsigned int nr_bytes)
{
}
/*
* DM Integrity profile, protection is performed layer above (dm-crypt)
*/
static const struct blk_integrity_profile dm_integrity_profile = {
.name = "DM-DIF-EXT-TAG",
.generate_fn = NULL,
.verify_fn = NULL,
.prepare_fn = dm_integrity_prepare,
.complete_fn = dm_integrity_complete,
};
static void dm_integrity_map_continue(struct dm_integrity_io *dio, bool from_map);
static void integrity_bio_wait(struct work_struct *w);
static void dm_integrity_dtr(struct dm_target *ti);
static void dm_integrity_io_error(struct dm_integrity_c *ic, const char *msg, int err)
{
if (err == -EILSEQ)
atomic64_inc(&ic->number_of_mismatches);
if (!cmpxchg(&ic->failed, 0, err))
DMERR("Error on %s: %d", msg, err);
}
static int dm_integrity_failed(struct dm_integrity_c *ic)
{
return READ_ONCE(ic->failed);
}
static bool dm_integrity_disable_recalculate(struct dm_integrity_c *ic)
{
if (ic->legacy_recalculate)
return false;
if (!(ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_HMAC)) ?
ic->internal_hash_alg.key || ic->journal_mac_alg.key :
ic->internal_hash_alg.key && !ic->journal_mac_alg.key)
return true;
return false;
}
static commit_id_t dm_integrity_commit_id(struct dm_integrity_c *ic, unsigned int i,
unsigned int j, unsigned char seq)
{
/*
* Xor the number with section and sector, so that if a piece of
* journal is written at wrong place, it is detected.
*/
return ic->commit_ids[seq] ^ cpu_to_le64(((__u64)i << 32) ^ j);
}
static void get_area_and_offset(struct dm_integrity_c *ic, sector_t data_sector,
sector_t *area, sector_t *offset)
{
if (!ic->meta_dev) {
__u8 log2_interleave_sectors = ic->sb->log2_interleave_sectors;
*area = data_sector >> log2_interleave_sectors;
*offset = (unsigned int)data_sector & ((1U << log2_interleave_sectors) - 1);
} else {
*area = 0;
*offset = data_sector;
}
}
#define sector_to_block(ic, n) \
do { \
BUG_ON((n) & (unsigned int)((ic)->sectors_per_block - 1)); \
(n) >>= (ic)->sb->log2_sectors_per_block; \
} while (0)
static __u64 get_metadata_sector_and_offset(struct dm_integrity_c *ic, sector_t area,
sector_t offset, unsigned int *metadata_offset)
{
__u64 ms;
unsigned int mo;
ms = area << ic->sb->log2_interleave_sectors;
if (likely(ic->log2_metadata_run >= 0))
ms += area << ic->log2_metadata_run;
else
ms += area * ic->metadata_run;
ms >>= ic->log2_buffer_sectors;
sector_to_block(ic, offset);
if (likely(ic->log2_tag_size >= 0)) {
ms += offset >> (SECTOR_SHIFT + ic->log2_buffer_sectors - ic->log2_tag_size);
mo = (offset << ic->log2_tag_size) & ((1U << SECTOR_SHIFT << ic->log2_buffer_sectors) - 1);
} else {
ms += (__u64)offset * ic->tag_size >> (SECTOR_SHIFT + ic->log2_buffer_sectors);
mo = (offset * ic->tag_size) & ((1U << SECTOR_SHIFT << ic->log2_buffer_sectors) - 1);
}
*metadata_offset = mo;
return ms;
}
static sector_t get_data_sector(struct dm_integrity_c *ic, sector_t area, sector_t offset)
{
sector_t result;
if (ic->meta_dev)
return offset;
result = area << ic->sb->log2_interleave_sectors;
if (likely(ic->log2_metadata_run >= 0))
result += (area + 1) << ic->log2_metadata_run;
else
result += (area + 1) * ic->metadata_run;
result += (sector_t)ic->initial_sectors + offset;
result += ic->start;
return result;
}
static void wraparound_section(struct dm_integrity_c *ic, unsigned int *sec_ptr)
{
if (unlikely(*sec_ptr >= ic->journal_sections))
*sec_ptr -= ic->journal_sections;
}
static void sb_set_version(struct dm_integrity_c *ic)
{
if (ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_HMAC))
ic->sb->version = SB_VERSION_5;
else if (ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_PADDING))
ic->sb->version = SB_VERSION_4;
else if (ic->mode == 'B' || ic->sb->flags & cpu_to_le32(SB_FLAG_DIRTY_BITMAP))
ic->sb->version = SB_VERSION_3;
else if (ic->meta_dev || ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING))
ic->sb->version = SB_VERSION_2;
else
ic->sb->version = SB_VERSION_1;
}
static int sb_mac(struct dm_integrity_c *ic, bool wr)
{
SHASH_DESC_ON_STACK(desc, ic->journal_mac);
int r;
unsigned int size = crypto_shash_digestsize(ic->journal_mac);
if (sizeof(struct superblock) + size > 1 << SECTOR_SHIFT) {
dm_integrity_io_error(ic, "digest is too long", -EINVAL);
return -EINVAL;
}
desc->tfm = ic->journal_mac;
r = crypto_shash_init(desc);
if (unlikely(r < 0)) {
dm_integrity_io_error(ic, "crypto_shash_init", r);
return r;
}
r = crypto_shash_update(desc, (__u8 *)ic->sb, (1 << SECTOR_SHIFT) - size);
if (unlikely(r < 0)) {
dm_integrity_io_error(ic, "crypto_shash_update", r);
return r;
}
if (likely(wr)) {
r = crypto_shash_final(desc, (__u8 *)ic->sb + (1 << SECTOR_SHIFT) - size);
if (unlikely(r < 0)) {
dm_integrity_io_error(ic, "crypto_shash_final", r);
return r;
}
} else {
__u8 result[HASH_MAX_DIGESTSIZE];
r = crypto_shash_final(desc, result);
if (unlikely(r < 0)) {
dm_integrity_io_error(ic, "crypto_shash_final", r);
return r;
}
if (memcmp((__u8 *)ic->sb + (1 << SECTOR_SHIFT) - size, result, size)) {
dm_integrity_io_error(ic, "superblock mac", -EILSEQ);
dm_audit_log_target(DM_MSG_PREFIX, "mac-superblock", ic->ti, 0);
return -EILSEQ;
}
}
return 0;
}
static int sync_rw_sb(struct dm_integrity_c *ic, blk_opf_t opf)
{
struct dm_io_request io_req;
struct dm_io_region io_loc;
const enum req_op op = opf & REQ_OP_MASK;
int r;
io_req.bi_opf = opf;
io_req.mem.type = DM_IO_KMEM;
io_req.mem.ptr.addr = ic->sb;
io_req.notify.fn = NULL;
io_req.client = ic->io;
io_loc.bdev = ic->meta_dev ? ic->meta_dev->bdev : ic->dev->bdev;
io_loc.sector = ic->start;
io_loc.count = SB_SECTORS;
if (op == REQ_OP_WRITE) {
sb_set_version(ic);
if (ic->journal_mac && ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_HMAC)) {
r = sb_mac(ic, true);
if (unlikely(r))
return r;
}
}
r = dm_io(&io_req, 1, &io_loc, NULL);
if (unlikely(r))
return r;
if (op == REQ_OP_READ) {
if (ic->mode != 'R' && ic->journal_mac && ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_HMAC)) {
r = sb_mac(ic, false);
if (unlikely(r))
return r;
}
}
return 0;
}
#define BITMAP_OP_TEST_ALL_SET 0
#define BITMAP_OP_TEST_ALL_CLEAR 1
#define BITMAP_OP_SET 2
#define BITMAP_OP_CLEAR 3
static bool block_bitmap_op(struct dm_integrity_c *ic, struct page_list *bitmap,
sector_t sector, sector_t n_sectors, int mode)
{
unsigned long bit, end_bit, this_end_bit, page, end_page;
unsigned long *data;
if (unlikely(((sector | n_sectors) & ((1 << ic->sb->log2_sectors_per_block) - 1)) != 0)) {
DMCRIT("invalid bitmap access (%llx,%llx,%d,%d,%d)",
sector,
n_sectors,
ic->sb->log2_sectors_per_block,
ic->log2_blocks_per_bitmap_bit,
mode);
BUG();
}
if (unlikely(!n_sectors))
return true;
bit = sector >> (ic->sb->log2_sectors_per_block + ic->log2_blocks_per_bitmap_bit);
end_bit = (sector + n_sectors - 1) >>
(ic->sb->log2_sectors_per_block + ic->log2_blocks_per_bitmap_bit);
page = bit / (PAGE_SIZE * 8);
bit %= PAGE_SIZE * 8;
end_page = end_bit / (PAGE_SIZE * 8);
end_bit %= PAGE_SIZE * 8;
repeat:
if (page < end_page)
this_end_bit = PAGE_SIZE * 8 - 1;
else
this_end_bit = end_bit;
data = lowmem_page_address(bitmap[page].page);
if (mode == BITMAP_OP_TEST_ALL_SET) {
while (bit <= this_end_bit) {
if (!(bit % BITS_PER_LONG) && this_end_bit >= bit + BITS_PER_LONG - 1) {
do {
if (data[bit / BITS_PER_LONG] != -1)
return false;
bit += BITS_PER_LONG;
} while (this_end_bit >= bit + BITS_PER_LONG - 1);
continue;
}
if (!test_bit(bit, data))
return false;
bit++;
}
} else if (mode == BITMAP_OP_TEST_ALL_CLEAR) {
while (bit <= this_end_bit) {
if (!(bit % BITS_PER_LONG) && this_end_bit >= bit + BITS_PER_LONG - 1) {
do {
if (data[bit / BITS_PER_LONG] != 0)
return false;
bit += BITS_PER_LONG;
} while (this_end_bit >= bit + BITS_PER_LONG - 1);
continue;
}
if (test_bit(bit, data))
return false;
bit++;
}
} else if (mode == BITMAP_OP_SET) {
while (bit <= this_end_bit) {
if (!(bit % BITS_PER_LONG) && this_end_bit >= bit + BITS_PER_LONG - 1) {
do {
data[bit / BITS_PER_LONG] = -1;
bit += BITS_PER_LONG;
} while (this_end_bit >= bit + BITS_PER_LONG - 1);
continue;
}
__set_bit(bit, data);
bit++;
}
} else if (mode == BITMAP_OP_CLEAR) {
if (!bit && this_end_bit == PAGE_SIZE * 8 - 1)
clear_page(data);
else {
while (bit <= this_end_bit) {
if (!(bit % BITS_PER_LONG) && this_end_bit >= bit + BITS_PER_LONG - 1) {
do {
data[bit / BITS_PER_LONG] = 0;
bit += BITS_PER_LONG;
} while (this_end_bit >= bit + BITS_PER_LONG - 1);
continue;
}
__clear_bit(bit, data);
bit++;
}
}
} else {
BUG();
}
if (unlikely(page < end_page)) {
bit = 0;
page++;
goto repeat;
}
return true;
}
static void block_bitmap_copy(struct dm_integrity_c *ic, struct page_list *dst, struct page_list *src)
{
unsigned int n_bitmap_pages = DIV_ROUND_UP(ic->n_bitmap_blocks, PAGE_SIZE / BITMAP_BLOCK_SIZE);
unsigned int i;
for (i = 0; i < n_bitmap_pages; i++) {
unsigned long *dst_data = lowmem_page_address(dst[i].page);
unsigned long *src_data = lowmem_page_address(src[i].page);
copy_page(dst_data, src_data);
}
}
static struct bitmap_block_status *sector_to_bitmap_block(struct dm_integrity_c *ic, sector_t sector)
{
unsigned int bit = sector >> (ic->sb->log2_sectors_per_block + ic->log2_blocks_per_bitmap_bit);
unsigned int bitmap_block = bit / (BITMAP_BLOCK_SIZE * 8);
BUG_ON(bitmap_block >= ic->n_bitmap_blocks);
return &ic->bbs[bitmap_block];
}
static void access_journal_check(struct dm_integrity_c *ic, unsigned int section, unsigned int offset,
bool e, const char *function)
{
#if defined(CONFIG_DM_DEBUG) || defined(INTERNAL_VERIFY)
unsigned int limit = e ? ic->journal_section_entries : ic->journal_section_sectors;
if (unlikely(section >= ic->journal_sections) ||
unlikely(offset >= limit)) {
DMCRIT("%s: invalid access at (%u,%u), limit (%u,%u)",
function, section, offset, ic->journal_sections, limit);
BUG();
}
#endif
}
static void page_list_location(struct dm_integrity_c *ic, unsigned int section, unsigned int offset,
unsigned int *pl_index, unsigned int *pl_offset)
{
unsigned int sector;
access_journal_check(ic, section, offset, false, "page_list_location");
sector = section * ic->journal_section_sectors + offset;
*pl_index = sector >> (PAGE_SHIFT - SECTOR_SHIFT);
*pl_offset = (sector << SECTOR_SHIFT) & (PAGE_SIZE - 1);
}
static struct journal_sector *access_page_list(struct dm_integrity_c *ic, struct page_list *pl,
unsigned int section, unsigned int offset, unsigned int *n_sectors)
{
unsigned int pl_index, pl_offset;
char *va;
page_list_location(ic, section, offset, &pl_index, &pl_offset);
if (n_sectors)
*n_sectors = (PAGE_SIZE - pl_offset) >> SECTOR_SHIFT;
va = lowmem_page_address(pl[pl_index].page);
return (struct journal_sector *)(va + pl_offset);
}
static struct journal_sector *access_journal(struct dm_integrity_c *ic, unsigned int section, unsigned int offset)
{
return access_page_list(ic, ic->journal, section, offset, NULL);
}
static struct journal_entry *access_journal_entry(struct dm_integrity_c *ic, unsigned int section, unsigned int n)
{
unsigned int rel_sector, offset;
struct journal_sector *js;
access_journal_check(ic, section, n, true, "access_journal_entry");
rel_sector = n % JOURNAL_BLOCK_SECTORS;
offset = n / JOURNAL_BLOCK_SECTORS;
js = access_journal(ic, section, rel_sector);
return (struct journal_entry *)((char *)js + offset * ic->journal_entry_size);
}
static struct journal_sector *access_journal_data(struct dm_integrity_c *ic, unsigned int section, unsigned int n)
{
n <<= ic->sb->log2_sectors_per_block;
n += JOURNAL_BLOCK_SECTORS;
access_journal_check(ic, section, n, false, "access_journal_data");
return access_journal(ic, section, n);
}
static void section_mac(struct dm_integrity_c *ic, unsigned int section, __u8 result[JOURNAL_MAC_SIZE])
{
SHASH_DESC_ON_STACK(desc, ic->journal_mac);
int r;
unsigned int j, size;
desc->tfm = ic->journal_mac;
r = crypto_shash_init(desc);
if (unlikely(r < 0)) {
dm_integrity_io_error(ic, "crypto_shash_init", r);
goto err;
}
if (ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_HMAC)) {
__le64 section_le;
r = crypto_shash_update(desc, (__u8 *)&ic->sb->salt, SALT_SIZE);
if (unlikely(r < 0)) {
dm_integrity_io_error(ic, "crypto_shash_update", r);
goto err;
}
section_le = cpu_to_le64(section);
r = crypto_shash_update(desc, (__u8 *)§ion_le, sizeof(section_le));
if (unlikely(r < 0)) {
dm_integrity_io_error(ic, "crypto_shash_update", r);
goto err;
}
}
for (j = 0; j < ic->journal_section_entries; j++) {
struct journal_entry *je = access_journal_entry(ic, section, j);
r = crypto_shash_update(desc, (__u8 *)&je->u.sector, sizeof(je->u.sector));
if (unlikely(r < 0)) {
dm_integrity_io_error(ic, "crypto_shash_update", r);
goto err;
}
}
size = crypto_shash_digestsize(ic->journal_mac);
if (likely(size <= JOURNAL_MAC_SIZE)) {
r = crypto_shash_final(desc, result);
if (unlikely(r < 0)) {
dm_integrity_io_error(ic, "crypto_shash_final", r);
goto err;
}
memset(result + size, 0, JOURNAL_MAC_SIZE - size);
} else {
__u8 digest[HASH_MAX_DIGESTSIZE];
if (WARN_ON(size > sizeof(digest))) {
dm_integrity_io_error(ic, "digest_size", -EINVAL);
goto err;
}
r = crypto_shash_final(desc, digest);
if (unlikely(r < 0)) {
dm_integrity_io_error(ic, "crypto_shash_final", r);
goto err;
}
memcpy(result, digest, JOURNAL_MAC_SIZE);
}
return;
err:
memset(result, 0, JOURNAL_MAC_SIZE);
}
static void rw_section_mac(struct dm_integrity_c *ic, unsigned int section, bool wr)
{
__u8 result[JOURNAL_MAC_SIZE];
unsigned int j;
if (!ic->journal_mac)
return;
section_mac(ic, section, result);
for (j = 0; j < JOURNAL_BLOCK_SECTORS; j++) {
struct journal_sector *js = access_journal(ic, section, j);
if (likely(wr))
memcpy(&js->mac, result + (j * JOURNAL_MAC_PER_SECTOR), JOURNAL_MAC_PER_SECTOR);
else {
if (memcmp(&js->mac, result + (j * JOURNAL_MAC_PER_SECTOR), JOURNAL_MAC_PER_SECTOR)) {
dm_integrity_io_error(ic, "journal mac", -EILSEQ);
dm_audit_log_target(DM_MSG_PREFIX, "mac-journal", ic->ti, 0);
}
}
}
}
static void complete_journal_op(void *context)
{
struct journal_completion *comp = context;
BUG_ON(!atomic_read(&comp->in_flight));
if (likely(atomic_dec_and_test(&comp->in_flight)))
complete(&comp->comp);
}
static void xor_journal(struct dm_integrity_c *ic, bool encrypt, unsigned int section,
unsigned int n_sections, struct journal_completion *comp)
{
struct async_submit_ctl submit;
size_t n_bytes = (size_t)(n_sections * ic->journal_section_sectors) << SECTOR_SHIFT;
unsigned int pl_index, pl_offset, section_index;
struct page_list *source_pl, *target_pl;
if (likely(encrypt)) {
source_pl = ic->journal;
target_pl = ic->journal_io;
} else {
source_pl = ic->journal_io;
target_pl = ic->journal;
}
page_list_location(ic, section, 0, &pl_index, &pl_offset);
atomic_add(roundup(pl_offset + n_bytes, PAGE_SIZE) >> PAGE_SHIFT, &comp->in_flight);
init_async_submit(&submit, ASYNC_TX_XOR_ZERO_DST, NULL, complete_journal_op, comp, NULL);
section_index = pl_index;
do {
size_t this_step;
struct page *src_pages[2];
struct page *dst_page;
while (unlikely(pl_index == section_index)) {
unsigned int dummy;
if (likely(encrypt))
rw_section_mac(ic, section, true);
section++;
n_sections--;
if (!n_sections)
break;
page_list_location(ic, section, 0, §ion_index, &dummy);
}
this_step = min(n_bytes, (size_t)PAGE_SIZE - pl_offset);
dst_page = target_pl[pl_index].page;
src_pages[0] = source_pl[pl_index].page;
src_pages[1] = ic->journal_xor[pl_index].page;
async_xor(dst_page, src_pages, pl_offset, 2, this_step, &submit);
pl_index++;
pl_offset = 0;
n_bytes -= this_step;
} while (n_bytes);
BUG_ON(n_sections);
async_tx_issue_pending_all();
}
static void complete_journal_encrypt(void *data, int err)
{
struct journal_completion *comp = data;
if (unlikely(err)) {
if (likely(err == -EINPROGRESS)) {
complete(&comp->ic->crypto_backoff);
return;
}
dm_integrity_io_error(comp->ic, "asynchronous encrypt", err);
}
complete_journal_op(comp);
}
static bool do_crypt(bool encrypt, struct skcipher_request *req, struct journal_completion *comp)
{
int r;
skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
complete_journal_encrypt, comp);
if (likely(encrypt))
r = crypto_skcipher_encrypt(req);
else
r = crypto_skcipher_decrypt(req);
if (likely(!r))
return false;
if (likely(r == -EINPROGRESS))
return true;
if (likely(r == -EBUSY)) {
wait_for_completion(&comp->ic->crypto_backoff);
reinit_completion(&comp->ic->crypto_backoff);
return true;
}
dm_integrity_io_error(comp->ic, "encrypt", r);
return false;
}
static void crypt_journal(struct dm_integrity_c *ic, bool encrypt, unsigned int section,
unsigned int n_sections, struct journal_completion *comp)
{
struct scatterlist **source_sg;
struct scatterlist **target_sg;
atomic_add(2, &comp->in_flight);
if (likely(encrypt)) {
source_sg = ic->journal_scatterlist;
target_sg = ic->journal_io_scatterlist;
} else {
source_sg = ic->journal_io_scatterlist;
target_sg = ic->journal_scatterlist;
}
do {
struct skcipher_request *req;
unsigned int ivsize;
char *iv;
if (likely(encrypt))
rw_section_mac(ic, section, true);
req = ic->sk_requests[section];
ivsize = crypto_skcipher_ivsize(ic->journal_crypt);
iv = req->iv;
memcpy(iv, iv + ivsize, ivsize);
req->src = source_sg[section];
req->dst = target_sg[section];
if (unlikely(do_crypt(encrypt, req, comp)))
atomic_inc(&comp->in_flight);
section++;
n_sections--;
} while (n_sections);
atomic_dec(&comp->in_flight);
complete_journal_op(comp);
}
static void encrypt_journal(struct dm_integrity_c *ic, bool encrypt, unsigned int section,
unsigned int n_sections, struct journal_completion *comp)
{
if (ic->journal_xor)
return xor_journal(ic, encrypt, section, n_sections, comp);
else
return crypt_journal(ic, encrypt, section, n_sections, comp);
}
static void complete_journal_io(unsigned long error, void *context)
{
struct journal_completion *comp = context;
if (unlikely(error != 0))
dm_integrity_io_error(comp->ic, "writing journal", -EIO);
complete_journal_op(comp);
}
static void rw_journal_sectors(struct dm_integrity_c *ic, blk_opf_t opf,
unsigned int sector, unsigned int n_sectors,
struct journal_completion *comp)
{
struct dm_io_request io_req;
struct dm_io_region io_loc;
unsigned int pl_index, pl_offset;
int r;
if (unlikely(dm_integrity_failed(ic))) {
if (comp)
complete_journal_io(-1UL, comp);
return;
}
pl_index = sector >> (PAGE_SHIFT - SECTOR_SHIFT);
pl_offset = (sector << SECTOR_SHIFT) & (PAGE_SIZE - 1);
io_req.bi_opf = opf;
io_req.mem.type = DM_IO_PAGE_LIST;
if (ic->journal_io)
io_req.mem.ptr.pl = &ic->journal_io[pl_index];
else
io_req.mem.ptr.pl = &ic->journal[pl_index];
io_req.mem.offset = pl_offset;
if (likely(comp != NULL)) {
io_req.notify.fn = complete_journal_io;
io_req.notify.context = comp;
} else {
io_req.notify.fn = NULL;
}
io_req.client = ic->io;
io_loc.bdev = ic->meta_dev ? ic->meta_dev->bdev : ic->dev->bdev;
io_loc.sector = ic->start + SB_SECTORS + sector;
io_loc.count = n_sectors;
r = dm_io(&io_req, 1, &io_loc, NULL);
if (unlikely(r)) {
dm_integrity_io_error(ic, (opf & REQ_OP_MASK) == REQ_OP_READ ?
"reading journal" : "writing journal", r);
if (comp) {
WARN_ONCE(1, "asynchronous dm_io failed: %d", r);
complete_journal_io(-1UL, comp);
}
}
}
static void rw_journal(struct dm_integrity_c *ic, blk_opf_t opf,
unsigned int section, unsigned int n_sections,
struct journal_completion *comp)
{
unsigned int sector, n_sectors;
sector = section * ic->journal_section_sectors;
n_sectors = n_sections * ic->journal_section_sectors;
rw_journal_sectors(ic, opf, sector, n_sectors, comp);
}
static void write_journal(struct dm_integrity_c *ic, unsigned int commit_start, unsigned int commit_sections)
{
struct journal_completion io_comp;
struct journal_completion crypt_comp_1;
struct journal_completion crypt_comp_2;
unsigned int i;
io_comp.ic = ic;
init_completion(&io_comp.comp);
if (commit_start + commit_sections <= ic->journal_sections) {
io_comp.in_flight = (atomic_t)ATOMIC_INIT(1);
if (ic->journal_io) {
crypt_comp_1.ic = ic;
init_completion(&crypt_comp_1.comp);
crypt_comp_1.in_flight = (atomic_t)ATOMIC_INIT(0);
encrypt_journal(ic, true, commit_start, commit_sections, &crypt_comp_1);
wait_for_completion_io(&crypt_comp_1.comp);
} else {
for (i = 0; i < commit_sections; i++)
rw_section_mac(ic, commit_start + i, true);
}
rw_journal(ic, REQ_OP_WRITE | REQ_FUA | REQ_SYNC, commit_start,
commit_sections, &io_comp);
} else {
unsigned int to_end;
io_comp.in_flight = (atomic_t)ATOMIC_INIT(2);
to_end = ic->journal_sections - commit_start;
if (ic->journal_io) {
crypt_comp_1.ic = ic;
init_completion(&crypt_comp_1.comp);
crypt_comp_1.in_flight = (atomic_t)ATOMIC_INIT(0);
encrypt_journal(ic, true, commit_start, to_end, &crypt_comp_1);
if (try_wait_for_completion(&crypt_comp_1.comp)) {
rw_journal(ic, REQ_OP_WRITE | REQ_FUA,
commit_start, to_end, &io_comp);
reinit_completion(&crypt_comp_1.comp);
crypt_comp_1.in_flight = (atomic_t)ATOMIC_INIT(0);
encrypt_journal(ic, true, 0, commit_sections - to_end, &crypt_comp_1);
wait_for_completion_io(&crypt_comp_1.comp);
} else {
crypt_comp_2.ic = ic;
init_completion(&crypt_comp_2.comp);
crypt_comp_2.in_flight = (atomic_t)ATOMIC_INIT(0);
encrypt_journal(ic, true, 0, commit_sections - to_end, &crypt_comp_2);
wait_for_completion_io(&crypt_comp_1.comp);
rw_journal(ic, REQ_OP_WRITE | REQ_FUA, commit_start, to_end, &io_comp);
wait_for_completion_io(&crypt_comp_2.comp);
}
} else {
for (i = 0; i < to_end; i++)
rw_section_mac(ic, commit_start + i, true);
rw_journal(ic, REQ_OP_WRITE | REQ_FUA, commit_start, to_end, &io_comp);
for (i = 0; i < commit_sections - to_end; i++)
rw_section_mac(ic, i, true);
}
rw_journal(ic, REQ_OP_WRITE | REQ_FUA, 0, commit_sections - to_end, &io_comp);
}
wait_for_completion_io(&io_comp.comp);
}
static void copy_from_journal(struct dm_integrity_c *ic, unsigned int section, unsigned int offset,
unsigned int n_sectors, sector_t target, io_notify_fn fn, void *data)
{
struct dm_io_request io_req;
struct dm_io_region io_loc;
int r;
unsigned int sector, pl_index, pl_offset;
BUG_ON((target | n_sectors | offset) & (unsigned int)(ic->sectors_per_block - 1));
if (unlikely(dm_integrity_failed(ic))) {
fn(-1UL, data);
return;
}
sector = section * ic->journal_section_sectors + JOURNAL_BLOCK_SECTORS + offset;
pl_index = sector >> (PAGE_SHIFT - SECTOR_SHIFT);
pl_offset = (sector << SECTOR_SHIFT) & (PAGE_SIZE - 1);
io_req.bi_opf = REQ_OP_WRITE;
io_req.mem.type = DM_IO_PAGE_LIST;
io_req.mem.ptr.pl = &ic->journal[pl_index];
io_req.mem.offset = pl_offset;
io_req.notify.fn = fn;
io_req.notify.context = data;
io_req.client = ic->io;
io_loc.bdev = ic->dev->bdev;
io_loc.sector = target;
io_loc.count = n_sectors;
r = dm_io(&io_req, 1, &io_loc, NULL);
if (unlikely(r)) {
WARN_ONCE(1, "asynchronous dm_io failed: %d", r);
fn(-1UL, data);
}
}
static bool ranges_overlap(struct dm_integrity_range *range1, struct dm_integrity_range *range2)
{
return range1->logical_sector < range2->logical_sector + range2->n_sectors &&
range1->logical_sector + range1->n_sectors > range2->logical_sector;
}
static bool add_new_range(struct dm_integrity_c *ic, struct dm_integrity_range *new_range, bool check_waiting)
{
struct rb_node **n = &ic->in_progress.rb_node;
struct rb_node *parent;
BUG_ON((new_range->logical_sector | new_range->n_sectors) & (unsigned int)(ic->sectors_per_block - 1));
if (likely(check_waiting)) {
struct dm_integrity_range *range;
list_for_each_entry(range, &ic->wait_list, wait_entry) {
if (unlikely(ranges_overlap(range, new_range)))
return false;
}
}
parent = NULL;
while (*n) {
struct dm_integrity_range *range = container_of(*n, struct dm_integrity_range, node);
parent = *n;
if (new_range->logical_sector + new_range->n_sectors <= range->logical_sector)
n = &range->node.rb_left;
else if (new_range->logical_sector >= range->logical_sector + range->n_sectors)
n = &range->node.rb_right;
else
return false;
}
rb_link_node(&new_range->node, parent, n);
rb_insert_color(&new_range->node, &ic->in_progress);
return true;
}
static void remove_range_unlocked(struct dm_integrity_c *ic, struct dm_integrity_range *range)
{
rb_erase(&range->node, &ic->in_progress);
while (unlikely(!list_empty(&ic->wait_list))) {
struct dm_integrity_range *last_range =
list_first_entry(&ic->wait_list, struct dm_integrity_range, wait_entry);
struct task_struct *last_range_task;
last_range_task = last_range->task;
list_del(&last_range->wait_entry);
if (!add_new_range(ic, last_range, false)) {
last_range->task = last_range_task;
list_add(&last_range->wait_entry, &ic->wait_list);
break;
}
last_range->waiting = false;
wake_up_process(last_range_task);
}
}
static void remove_range(struct dm_integrity_c *ic, struct dm_integrity_range *range)
{
unsigned long flags;
spin_lock_irqsave(&ic->endio_wait.lock, flags);
remove_range_unlocked(ic, range);
spin_unlock_irqrestore(&ic->endio_wait.lock, flags);
}
static void wait_and_add_new_range(struct dm_integrity_c *ic, struct dm_integrity_range *new_range)
{
new_range->waiting = true;
list_add_tail(&new_range->wait_entry, &ic->wait_list);
new_range->task = current;
do {
__set_current_state(TASK_UNINTERRUPTIBLE);
spin_unlock_irq(&ic->endio_wait.lock);
io_schedule();
spin_lock_irq(&ic->endio_wait.lock);
} while (unlikely(new_range->waiting));
}
static void add_new_range_and_wait(struct dm_integrity_c *ic, struct dm_integrity_range *new_range)
{
if (unlikely(!add_new_range(ic, new_range, true)))
wait_and_add_new_range(ic, new_range);
}
static void init_journal_node(struct journal_node *node)
{
RB_CLEAR_NODE(&node->node);
node->sector = (sector_t)-1;
}
static void add_journal_node(struct dm_integrity_c *ic, struct journal_node *node, sector_t sector)
{
struct rb_node **link;
struct rb_node *parent;
node->sector = sector;
BUG_ON(!RB_EMPTY_NODE(&node->node));
link = &ic->journal_tree_root.rb_node;
parent = NULL;
while (*link) {
struct journal_node *j;
parent = *link;
j = container_of(parent, struct journal_node, node);
if (sector < j->sector)
link = &j->node.rb_left;
else
link = &j->node.rb_right;
}
rb_link_node(&node->node, parent, link);
rb_insert_color(&node->node, &ic->journal_tree_root);
}
static void remove_journal_node(struct dm_integrity_c *ic, struct journal_node *node)
{
BUG_ON(RB_EMPTY_NODE(&node->node));
rb_erase(&node->node, &ic->journal_tree_root);
init_journal_node(node);
}
#define NOT_FOUND (-1U)
static unsigned int find_journal_node(struct dm_integrity_c *ic, sector_t sector, sector_t *next_sector)
{
struct rb_node *n = ic->journal_tree_root.rb_node;
unsigned int found = NOT_FOUND;
*next_sector = (sector_t)-1;
while (n) {
struct journal_node *j = container_of(n, struct journal_node, node);
if (sector == j->sector)
found = j - ic->journal_tree;
if (sector < j->sector) {
*next_sector = j->sector;
n = j->node.rb_left;
} else
n = j->node.rb_right;
}
return found;
}
static bool test_journal_node(struct dm_integrity_c *ic, unsigned int pos, sector_t sector)
{
struct journal_node *node, *next_node;
struct rb_node *next;
if (unlikely(pos >= ic->journal_entries))
return false;
node = &ic->journal_tree[pos];
if (unlikely(RB_EMPTY_NODE(&node->node)))
return false;
if (unlikely(node->sector != sector))
return false;
next = rb_next(&node->node);
if (unlikely(!next))
return true;
next_node = container_of(next, struct journal_node, node);
return next_node->sector != sector;
}
static bool find_newer_committed_node(struct dm_integrity_c *ic, struct journal_node *node)
{
struct rb_node *next;
struct journal_node *next_node;
unsigned int next_section;
BUG_ON(RB_EMPTY_NODE(&node->node));
next = rb_next(&node->node);
if (unlikely(!next))
return false;
next_node = container_of(next, struct journal_node, node);
if (next_node->sector != node->sector)
return false;
next_section = (unsigned int)(next_node - ic->journal_tree) / ic->journal_section_entries;
if (next_section >= ic->committed_section &&
next_section < ic->committed_section + ic->n_committed_sections)
return true;
if (next_section + ic->journal_sections < ic->committed_section + ic->n_committed_sections)
return true;
return false;
}
#define TAG_READ 0
#define TAG_WRITE 1
#define TAG_CMP 2
static int dm_integrity_rw_tag(struct dm_integrity_c *ic, unsigned char *tag, sector_t *metadata_block,
unsigned int *metadata_offset, unsigned int total_size, int op)
{
#define MAY_BE_FILLER 1
#define MAY_BE_HASH 2
unsigned int hash_offset = 0;
unsigned int may_be = MAY_BE_HASH | (ic->discard ? MAY_BE_FILLER : 0);
do {
unsigned char *data, *dp;
struct dm_buffer *b;
unsigned int to_copy;
int r;
r = dm_integrity_failed(ic);
if (unlikely(r))
return r;
data = dm_bufio_read(ic->bufio, *metadata_block, &b);
if (IS_ERR(data))
return PTR_ERR(data);
to_copy = min((1U << SECTOR_SHIFT << ic->log2_buffer_sectors) - *metadata_offset, total_size);
dp = data + *metadata_offset;
if (op == TAG_READ) {
memcpy(tag, dp, to_copy);
} else if (op == TAG_WRITE) {
if (memcmp(dp, tag, to_copy)) {
memcpy(dp, tag, to_copy);
dm_bufio_mark_partial_buffer_dirty(b, *metadata_offset, *metadata_offset + to_copy);
}
} else {
/* e.g.: op == TAG_CMP */
if (likely(is_power_of_2(ic->tag_size))) {
if (unlikely(memcmp(dp, tag, to_copy)))
if (unlikely(!ic->discard) ||
unlikely(memchr_inv(dp, DISCARD_FILLER, to_copy) != NULL)) {
goto thorough_test;
}
} else {
unsigned int i, ts;
thorough_test:
ts = total_size;
for (i = 0; i < to_copy; i++, ts--) {
if (unlikely(dp[i] != tag[i]))
may_be &= ~MAY_BE_HASH;
if (likely(dp[i] != DISCARD_FILLER))
may_be &= ~MAY_BE_FILLER;
hash_offset++;
if (unlikely(hash_offset == ic->tag_size)) {
if (unlikely(!may_be)) {
dm_bufio_release(b);
return ts;
}
hash_offset = 0;
may_be = MAY_BE_HASH | (ic->discard ? MAY_BE_FILLER : 0);
}
}
}
}
dm_bufio_release(b);
tag += to_copy;
*metadata_offset += to_copy;
if (unlikely(*metadata_offset == 1U << SECTOR_SHIFT << ic->log2_buffer_sectors)) {
(*metadata_block)++;
*metadata_offset = 0;
}
if (unlikely(!is_power_of_2(ic->tag_size)))
hash_offset = (hash_offset + to_copy) % ic->tag_size;
total_size -= to_copy;
} while (unlikely(total_size));
return 0;
#undef MAY_BE_FILLER
#undef MAY_BE_HASH
}
struct flush_request {
struct dm_io_request io_req;
struct dm_io_region io_reg;
struct dm_integrity_c *ic;
struct completion comp;
};
static void flush_notify(unsigned long error, void *fr_)
{
struct flush_request *fr = fr_;
if (unlikely(error != 0))
dm_integrity_io_error(fr->ic, "flushing disk cache", -EIO);
complete(&fr->comp);
}
static void dm_integrity_flush_buffers(struct dm_integrity_c *ic, bool flush_data)
{
int r;
struct flush_request fr;
if (!ic->meta_dev)
flush_data = false;
if (flush_data) {
fr.io_req.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH | REQ_SYNC,
fr.io_req.mem.type = DM_IO_KMEM,
fr.io_req.mem.ptr.addr = NULL,
fr.io_req.notify.fn = flush_notify,
fr.io_req.notify.context = &fr;
fr.io_req.client = dm_bufio_get_dm_io_client(ic->bufio),
fr.io_reg.bdev = ic->dev->bdev,
fr.io_reg.sector = 0,
fr.io_reg.count = 0,
fr.ic = ic;
init_completion(&fr.comp);
r = dm_io(&fr.io_req, 1, &fr.io_reg, NULL);
BUG_ON(r);
}
r = dm_bufio_write_dirty_buffers(ic->bufio);
if (unlikely(r))
dm_integrity_io_error(ic, "writing tags", r);
if (flush_data)
wait_for_completion(&fr.comp);
}
static void sleep_on_endio_wait(struct dm_integrity_c *ic)
{
DECLARE_WAITQUEUE(wait, current);
__add_wait_queue(&ic->endio_wait, &wait);
__set_current_state(TASK_UNINTERRUPTIBLE);
spin_unlock_irq(&ic->endio_wait.lock);
io_schedule();
spin_lock_irq(&ic->endio_wait.lock);
__remove_wait_queue(&ic->endio_wait, &wait);
}
static void autocommit_fn(struct timer_list *t)
{
struct dm_integrity_c *ic = from_timer(ic, t, autocommit_timer);
if (likely(!dm_integrity_failed(ic)))
queue_work(ic->commit_wq, &ic->commit_work);
}
static void schedule_autocommit(struct dm_integrity_c *ic)
{
if (!timer_pending(&ic->autocommit_timer))
mod_timer(&ic->autocommit_timer, jiffies + ic->autocommit_jiffies);
}
static void submit_flush_bio(struct dm_integrity_c *ic, struct dm_integrity_io *dio)
{
struct bio *bio;
unsigned long flags;
spin_lock_irqsave(&ic->endio_wait.lock, flags);
bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
bio_list_add(&ic->flush_bio_list, bio);
spin_unlock_irqrestore(&ic->endio_wait.lock, flags);
queue_work(ic->commit_wq, &ic->commit_work);
}
static void do_endio(struct dm_integrity_c *ic, struct bio *bio)
{
int r;
r = dm_integrity_failed(ic);
if (unlikely(r) && !bio->bi_status)
bio->bi_status = errno_to_blk_status(r);
if (unlikely(ic->synchronous_mode) && bio_op(bio) == REQ_OP_WRITE) {
unsigned long flags;
spin_lock_irqsave(&ic->endio_wait.lock, flags);
bio_list_add(&ic->synchronous_bios, bio);
queue_delayed_work(ic->commit_wq, &ic->bitmap_flush_work, 0);
spin_unlock_irqrestore(&ic->endio_wait.lock, flags);
return;
}
bio_endio(bio);
}
static void do_endio_flush(struct dm_integrity_c *ic, struct dm_integrity_io *dio)
{
struct bio *bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
if (unlikely(dio->fua) && likely(!bio->bi_status) && likely(!dm_integrity_failed(ic)))
submit_flush_bio(ic, dio);
else
do_endio(ic, bio);
}
static void dec_in_flight(struct dm_integrity_io *dio)
{
if (atomic_dec_and_test(&dio->in_flight)) {
struct dm_integrity_c *ic = dio->ic;
struct bio *bio;
remove_range(ic, &dio->range);
if (dio->op == REQ_OP_WRITE || unlikely(dio->op == REQ_OP_DISCARD))
schedule_autocommit(ic);
bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
if (unlikely(dio->bi_status) && !bio->bi_status)
bio->bi_status = dio->bi_status;
if (likely(!bio->bi_status) && unlikely(bio_sectors(bio) != dio->range.n_sectors)) {
dio->range.logical_sector += dio->range.n_sectors;
bio_advance(bio, dio->range.n_sectors << SECTOR_SHIFT);
INIT_WORK(&dio->work, integrity_bio_wait);
queue_work(ic->offload_wq, &dio->work);
return;
}
do_endio_flush(ic, dio);
}
}
static void integrity_end_io(struct bio *bio)
{
struct dm_integrity_io *dio = dm_per_bio_data(bio, sizeof(struct dm_integrity_io));
dm_bio_restore(&dio->bio_details, bio);
if (bio->bi_integrity)
bio->bi_opf |= REQ_INTEGRITY;
if (dio->completion)
complete(dio->completion);
dec_in_flight(dio);
}
static void integrity_sector_checksum(struct dm_integrity_c *ic, sector_t sector,
const char *data, char *result)
{
__le64 sector_le = cpu_to_le64(sector);
SHASH_DESC_ON_STACK(req, ic->internal_hash);
int r;
unsigned int digest_size;
req->tfm = ic->internal_hash;
r = crypto_shash_init(req);
if (unlikely(r < 0)) {
dm_integrity_io_error(ic, "crypto_shash_init", r);
goto failed;
}
if (ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_HMAC)) {
r = crypto_shash_update(req, (__u8 *)&ic->sb->salt, SALT_SIZE);
if (unlikely(r < 0)) {
dm_integrity_io_error(ic, "crypto_shash_update", r);
goto failed;
}
}
r = crypto_shash_update(req, (const __u8 *)§or_le, sizeof(sector_le));
if (unlikely(r < 0)) {
dm_integrity_io_error(ic, "crypto_shash_update", r);
goto failed;
}
r = crypto_shash_update(req, data, ic->sectors_per_block << SECTOR_SHIFT);
if (unlikely(r < 0)) {
dm_integrity_io_error(ic, "crypto_shash_update", r);
goto failed;
}
r = crypto_shash_final(req, result);
if (unlikely(r < 0)) {
dm_integrity_io_error(ic, "crypto_shash_final", r);
goto failed;
}
digest_size = crypto_shash_digestsize(ic->internal_hash);
if (unlikely(digest_size < ic->tag_size))
memset(result + digest_size, 0, ic->tag_size - digest_size);
return;
failed:
/* this shouldn't happen anyway, the hash functions have no reason to fail */
get_random_bytes(result, ic->tag_size);
}
static void integrity_metadata(struct work_struct *w)
{
struct dm_integrity_io *dio = container_of(w, struct dm_integrity_io, work);
struct dm_integrity_c *ic = dio->ic;
int r;
if (ic->internal_hash) {
struct bvec_iter iter;
struct bio_vec bv;
unsigned int digest_size = crypto_shash_digestsize(ic->internal_hash);
struct bio *bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
char *checksums;
unsigned int extra_space = unlikely(digest_size > ic->tag_size) ? digest_size - ic->tag_size : 0;
char checksums_onstack[max_t(size_t, HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)];
sector_t sector;
unsigned int sectors_to_process;
if (unlikely(ic->mode == 'R'))
goto skip_io;
if (likely(dio->op != REQ_OP_DISCARD))
checksums = kmalloc((PAGE_SIZE >> SECTOR_SHIFT >> ic->sb->log2_sectors_per_block) * ic->tag_size + extra_space,
GFP_NOIO | __GFP_NORETRY | __GFP_NOWARN);
else
checksums = kmalloc(PAGE_SIZE, GFP_NOIO | __GFP_NORETRY | __GFP_NOWARN);
if (!checksums) {
checksums = checksums_onstack;
if (WARN_ON(extra_space &&
digest_size > sizeof(checksums_onstack))) {
r = -EINVAL;
goto error;
}
}
if (unlikely(dio->op == REQ_OP_DISCARD)) {
unsigned int bi_size = dio->bio_details.bi_iter.bi_size;
unsigned int max_size = likely(checksums != checksums_onstack) ? PAGE_SIZE : HASH_MAX_DIGESTSIZE;
unsigned int max_blocks = max_size / ic->tag_size;
memset(checksums, DISCARD_FILLER, max_size);
while (bi_size) {
unsigned int this_step_blocks = bi_size >> (SECTOR_SHIFT + ic->sb->log2_sectors_per_block);
this_step_blocks = min(this_step_blocks, max_blocks);
r = dm_integrity_rw_tag(ic, checksums, &dio->metadata_block, &dio->metadata_offset,
this_step_blocks * ic->tag_size, TAG_WRITE);
if (unlikely(r)) {
if (likely(checksums != checksums_onstack))
kfree(checksums);
goto error;
}
bi_size -= this_step_blocks << (SECTOR_SHIFT + ic->sb->log2_sectors_per_block);
}
if (likely(checksums != checksums_onstack))
kfree(checksums);
goto skip_io;
}
sector = dio->range.logical_sector;
sectors_to_process = dio->range.n_sectors;
__bio_for_each_segment(bv, bio, iter, dio->bio_details.bi_iter) {
unsigned int pos;
char *mem, *checksums_ptr;
again:
mem = bvec_kmap_local(&bv);
pos = 0;
checksums_ptr = checksums;
do {
integrity_sector_checksum(ic, sector, mem + pos, checksums_ptr);
checksums_ptr += ic->tag_size;
sectors_to_process -= ic->sectors_per_block;
pos += ic->sectors_per_block << SECTOR_SHIFT;
sector += ic->sectors_per_block;
} while (pos < bv.bv_len && sectors_to_process && checksums != checksums_onstack);
kunmap_local(mem);
r = dm_integrity_rw_tag(ic, checksums, &dio->metadata_block, &dio->metadata_offset,
checksums_ptr - checksums, dio->op == REQ_OP_READ ? TAG_CMP : TAG_WRITE);
if (unlikely(r)) {
if (r > 0) {
sector_t s;
s = sector - ((r + ic->tag_size - 1) / ic->tag_size);
DMERR_LIMIT("%pg: Checksum failed at sector 0x%llx",
bio->bi_bdev, s);
r = -EILSEQ;
atomic64_inc(&ic->number_of_mismatches);
dm_audit_log_bio(DM_MSG_PREFIX, "integrity-checksum",
bio, s, 0);
}
if (likely(checksums != checksums_onstack))
kfree(checksums);
goto error;
}
if (!sectors_to_process)
break;
if (unlikely(pos < bv.bv_len)) {
bv.bv_offset += pos;
bv.bv_len -= pos;
goto again;
}
}
if (likely(checksums != checksums_onstack))
kfree(checksums);
} else {
struct bio_integrity_payload *bip = dio->bio_details.bi_integrity;
if (bip) {
struct bio_vec biv;
struct bvec_iter iter;
unsigned int data_to_process = dio->range.n_sectors;
sector_to_block(ic, data_to_process);
data_to_process *= ic->tag_size;
bip_for_each_vec(biv, bip, iter) {
unsigned char *tag;
unsigned int this_len;
BUG_ON(PageHighMem(biv.bv_page));
tag = bvec_virt(&biv);
this_len = min(biv.bv_len, data_to_process);
r = dm_integrity_rw_tag(ic, tag, &dio->metadata_block, &dio->metadata_offset,
this_len, dio->op == REQ_OP_READ ? TAG_READ : TAG_WRITE);
if (unlikely(r))
goto error;
data_to_process -= this_len;
if (!data_to_process)
break;
}
}
}
skip_io:
dec_in_flight(dio);
return;
error:
dio->bi_status = errno_to_blk_status(r);
dec_in_flight(dio);
}
static int dm_integrity_map(struct dm_target *ti, struct bio *bio)
{
struct dm_integrity_c *ic = ti->private;
struct dm_integrity_io *dio = dm_per_bio_data(bio, sizeof(struct dm_integrity_io));
struct bio_integrity_payload *bip;
sector_t area, offset;
dio->ic = ic;
dio->bi_status = 0;
dio->op = bio_op(bio);
if (unlikely(dio->op == REQ_OP_DISCARD)) {
if (ti->max_io_len) {
sector_t sec = dm_target_offset(ti, bio->bi_iter.bi_sector);
unsigned int log2_max_io_len = __fls(ti->max_io_len);
sector_t start_boundary = sec >> log2_max_io_len;
sector_t end_boundary = (sec + bio_sectors(bio) - 1) >> log2_max_io_len;
if (start_boundary < end_boundary) {
sector_t len = ti->max_io_len - (sec & (ti->max_io_len - 1));
dm_accept_partial_bio(bio, len);
}
}
}
if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
submit_flush_bio(ic, dio);
return DM_MAPIO_SUBMITTED;
}
dio->range.logical_sector = dm_target_offset(ti, bio->bi_iter.bi_sector);
dio->fua = dio->op == REQ_OP_WRITE && bio->bi_opf & REQ_FUA;
if (unlikely(dio->fua)) {
/*
* Don't pass down the FUA flag because we have to flush
* disk cache anyway.
*/
bio->bi_opf &= ~REQ_FUA;
}
if (unlikely(dio->range.logical_sector + bio_sectors(bio) > ic->provided_data_sectors)) {
DMERR("Too big sector number: 0x%llx + 0x%x > 0x%llx",
dio->range.logical_sector, bio_sectors(bio),
ic->provided_data_sectors);
return DM_MAPIO_KILL;
}
if (unlikely((dio->range.logical_sector | bio_sectors(bio)) & (unsigned int)(ic->sectors_per_block - 1))) {
DMERR("Bio not aligned on %u sectors: 0x%llx, 0x%x",
ic->sectors_per_block,
dio->range.logical_sector, bio_sectors(bio));
return DM_MAPIO_KILL;
}
if (ic->sectors_per_block > 1 && likely(dio->op != REQ_OP_DISCARD)) {
struct bvec_iter iter;
struct bio_vec bv;
bio_for_each_segment(bv, bio, iter) {
if (unlikely(bv.bv_len & ((ic->sectors_per_block << SECTOR_SHIFT) - 1))) {
DMERR("Bio vector (%u,%u) is not aligned on %u-sector boundary",
bv.bv_offset, bv.bv_len, ic->sectors_per_block);
return DM_MAPIO_KILL;
}
}
}
bip = bio_integrity(bio);
if (!ic->internal_hash) {
if (bip) {
unsigned int wanted_tag_size = bio_sectors(bio) >> ic->sb->log2_sectors_per_block;
if (ic->log2_tag_size >= 0)
wanted_tag_size <<= ic->log2_tag_size;
else
wanted_tag_size *= ic->tag_size;
if (unlikely(wanted_tag_size != bip->bip_iter.bi_size)) {
DMERR("Invalid integrity data size %u, expected %u",
bip->bip_iter.bi_size, wanted_tag_size);
return DM_MAPIO_KILL;
}
}
} else {
if (unlikely(bip != NULL)) {
DMERR("Unexpected integrity data when using internal hash");
return DM_MAPIO_KILL;
}
}
if (unlikely(ic->mode == 'R') && unlikely(dio->op != REQ_OP_READ))
return DM_MAPIO_KILL;
get_area_and_offset(ic, dio->range.logical_sector, &area, &offset);
dio->metadata_block = get_metadata_sector_and_offset(ic, area, offset, &dio->metadata_offset);
bio->bi_iter.bi_sector = get_data_sector(ic, area, offset);
dm_integrity_map_continue(dio, true);
return DM_MAPIO_SUBMITTED;
}
static bool __journal_read_write(struct dm_integrity_io *dio, struct bio *bio,
unsigned int journal_section, unsigned int journal_entry)
{
struct dm_integrity_c *ic = dio->ic;
sector_t logical_sector;
unsigned int n_sectors;
logical_sector = dio->range.logical_sector;
n_sectors = dio->range.n_sectors;
do {
struct bio_vec bv = bio_iovec(bio);
char *mem;
if (unlikely(bv.bv_len >> SECTOR_SHIFT > n_sectors))
bv.bv_len = n_sectors << SECTOR_SHIFT;
n_sectors -= bv.bv_len >> SECTOR_SHIFT;
bio_advance_iter(bio, &bio->bi_iter, bv.bv_len);
retry_kmap:
mem = kmap_local_page(bv.bv_page);
if (likely(dio->op == REQ_OP_WRITE))
flush_dcache_page(bv.bv_page);
do {
struct journal_entry *je = access_journal_entry(ic, journal_section, journal_entry);
if (unlikely(dio->op == REQ_OP_READ)) {
struct journal_sector *js;
char *mem_ptr;
unsigned int s;
if (unlikely(journal_entry_is_inprogress(je))) {
flush_dcache_page(bv.bv_page);
kunmap_local(mem);
__io_wait_event(ic->copy_to_journal_wait, !journal_entry_is_inprogress(je));
goto retry_kmap;
}
smp_rmb();
BUG_ON(journal_entry_get_sector(je) != logical_sector);
js = access_journal_data(ic, journal_section, journal_entry);
mem_ptr = mem + bv.bv_offset;
s = 0;
do {
memcpy(mem_ptr, js, JOURNAL_SECTOR_DATA);
*(commit_id_t *)(mem_ptr + JOURNAL_SECTOR_DATA) = je->last_bytes[s];
js++;
mem_ptr += 1 << SECTOR_SHIFT;
} while (++s < ic->sectors_per_block);
#ifdef INTERNAL_VERIFY
if (ic->internal_hash) {
char checksums_onstack[max_t(size_t, HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)];
integrity_sector_checksum(ic, logical_sector, mem + bv.bv_offset, checksums_onstack);
if (unlikely(memcmp(checksums_onstack, journal_entry_tag(ic, je), ic->tag_size))) {
DMERR_LIMIT("Checksum failed when reading from journal, at sector 0x%llx",
logical_sector);
dm_audit_log_bio(DM_MSG_PREFIX, "journal-checksum",
bio, logical_sector, 0);
}
}
#endif
}
if (!ic->internal_hash) {
struct bio_integrity_payload *bip = bio_integrity(bio);
unsigned int tag_todo = ic->tag_size;
char *tag_ptr = journal_entry_tag(ic, je);
if (bip) {
do {
struct bio_vec biv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
unsigned int tag_now = min(biv.bv_len, tag_todo);
char *tag_addr;
BUG_ON(PageHighMem(biv.bv_page));
tag_addr = bvec_virt(&biv);
if (likely(dio->op == REQ_OP_WRITE))
memcpy(tag_ptr, tag_addr, tag_now);
else
memcpy(tag_addr, tag_ptr, tag_now);
bvec_iter_advance(bip->bip_vec, &bip->bip_iter, tag_now);
tag_ptr += tag_now;
tag_todo -= tag_now;
} while (unlikely(tag_todo));
} else if (likely(dio->op == REQ_OP_WRITE))
memset(tag_ptr, 0, tag_todo);
}
if (likely(dio->op == REQ_OP_WRITE)) {
struct journal_sector *js;
unsigned int s;
js = access_journal_data(ic, journal_section, journal_entry);
memcpy(js, mem + bv.bv_offset, ic->sectors_per_block << SECTOR_SHIFT);
s = 0;
do {
je->last_bytes[s] = js[s].commit_id;
} while (++s < ic->sectors_per_block);
if (ic->internal_hash) {
unsigned int digest_size = crypto_shash_digestsize(ic->internal_hash);
if (unlikely(digest_size > ic->tag_size)) {
char checksums_onstack[HASH_MAX_DIGESTSIZE];
integrity_sector_checksum(ic, logical_sector, (char *)js, checksums_onstack);
memcpy(journal_entry_tag(ic, je), checksums_onstack, ic->tag_size);
} else
integrity_sector_checksum(ic, logical_sector, (char *)js, journal_entry_tag(ic, je));
}
journal_entry_set_sector(je, logical_sector);
}
logical_sector += ic->sectors_per_block;
journal_entry++;
if (unlikely(journal_entry == ic->journal_section_entries)) {
journal_entry = 0;
journal_section++;
wraparound_section(ic, &journal_section);
}
bv.bv_offset += ic->sectors_per_block << SECTOR_SHIFT;
} while (bv.bv_len -= ic->sectors_per_block << SECTOR_SHIFT);
if (unlikely(dio->op == REQ_OP_READ))
flush_dcache_page(bv.bv_page);
kunmap_local(mem);
} while (n_sectors);
if (likely(dio->op == REQ_OP_WRITE)) {
smp_mb();
if (unlikely(waitqueue_active(&ic->copy_to_journal_wait)))
wake_up(&ic->copy_to_journal_wait);
if (READ_ONCE(ic->free_sectors) <= ic->free_sectors_threshold)
queue_work(ic->commit_wq, &ic->commit_work);
else
schedule_autocommit(ic);
} else
remove_range(ic, &dio->range);
if (unlikely(bio->bi_iter.bi_size)) {
sector_t area, offset;
dio->range.logical_sector = logical_sector;
get_area_and_offset(ic, dio->range.logical_sector, &area, &offset);
dio->metadata_block = get_metadata_sector_and_offset(ic, area, offset, &dio->metadata_offset);
return true;
}
return false;
}
static void dm_integrity_map_continue(struct dm_integrity_io *dio, bool from_map)
{
struct dm_integrity_c *ic = dio->ic;
struct bio *bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io));
unsigned int journal_section, journal_entry;
unsigned int journal_read_pos;
struct completion read_comp;
bool discard_retried = false;
bool need_sync_io = ic->internal_hash && dio->op == REQ_OP_READ;
if (unlikely(dio->op == REQ_OP_DISCARD) && ic->mode != 'D')
need_sync_io = true;
if (need_sync_io && from_map) {
INIT_WORK(&dio->work, integrity_bio_wait);
queue_work(ic->offload_wq, &dio->work);
return;
}
lock_retry:
spin_lock_irq(&ic->endio_wait.lock);
retry:
if (unlikely(dm_integrity_failed(ic))) {
spin_unlock_irq(&ic->endio_wait.lock);
do_endio(ic, bio);
return;
}
dio->range.n_sectors = bio_sectors(bio);
journal_read_pos = NOT_FOUND;
if (ic->mode == 'J' && likely(dio->op != REQ_OP_DISCARD)) {
if (dio->op == REQ_OP_WRITE) {
unsigned int next_entry, i, pos;
unsigned int ws, we, range_sectors;
dio->range.n_sectors = min(dio->range.n_sectors,
(sector_t)ic->free_sectors << ic->sb->log2_sectors_per_block);
if (unlikely(!dio->range.n_sectors)) {
if (from_map)
goto offload_to_thread;
sleep_on_endio_wait(ic);
goto retry;
}
range_sectors = dio->range.n_sectors >> ic->sb->log2_sectors_per_block;
ic->free_sectors -= range_sectors;
journal_section = ic->free_section;
journal_entry = ic->free_section_entry;
next_entry = ic->free_section_entry + range_sectors;
ic->free_section_entry = next_entry % ic->journal_section_entries;
ic->free_section += next_entry / ic->journal_section_entries;
ic->n_uncommitted_sections += next_entry / ic->journal_section_entries;
wraparound_section(ic, &ic->free_section);
pos = journal_section * ic->journal_section_entries + journal_entry;
ws = journal_section;
we = journal_entry;
i = 0;
do {
struct journal_entry *je;
add_journal_node(ic, &ic->journal_tree[pos], dio->range.logical_sector + i);
pos++;
if (unlikely(pos >= ic->journal_entries))
pos = 0;
je = access_journal_entry(ic, ws, we);
BUG_ON(!journal_entry_is_unused(je));
journal_entry_set_inprogress(je);
we++;
if (unlikely(we == ic->journal_section_entries)) {
we = 0;
ws++;
wraparound_section(ic, &ws);
}
} while ((i += ic->sectors_per_block) < dio->range.n_sectors);
spin_unlock_irq(&ic->endio_wait.lock);
goto journal_read_write;
} else {
sector_t next_sector;
journal_read_pos = find_journal_node(ic, dio->range.logical_sector, &next_sector);
if (likely(journal_read_pos == NOT_FOUND)) {
if (unlikely(dio->range.n_sectors > next_sector - dio->range.logical_sector))
dio->range.n_sectors = next_sector - dio->range.logical_sector;
} else {
unsigned int i;
unsigned int jp = journal_read_pos + 1;
for (i = ic->sectors_per_block; i < dio->range.n_sectors; i += ic->sectors_per_block, jp++) {
if (!test_journal_node(ic, jp, dio->range.logical_sector + i))
break;
}
dio->range.n_sectors = i;
}
}
}
if (unlikely(!add_new_range(ic, &dio->range, true))) {
/*
* We must not sleep in the request routine because it could
* stall bios on current->bio_list.
* So, we offload the bio to a workqueue if we have to sleep.
*/
if (from_map) {
offload_to_thread:
spin_unlock_irq(&ic->endio_wait.lock);
INIT_WORK(&dio->work, integrity_bio_wait);
queue_work(ic->wait_wq, &dio->work);
return;
}
if (journal_read_pos != NOT_FOUND)
dio->range.n_sectors = ic->sectors_per_block;
wait_and_add_new_range(ic, &dio->range);
/*
* wait_and_add_new_range drops the spinlock, so the journal
* may have been changed arbitrarily. We need to recheck.
* To simplify the code, we restrict I/O size to just one block.
*/
if (journal_read_pos != NOT_FOUND) {
sector_t next_sector;
unsigned int new_pos;
new_pos = find_journal_node(ic, dio->range.logical_sector, &next_sector);
if (unlikely(new_pos != journal_read_pos)) {
remove_range_unlocked(ic, &dio->range);
goto retry;
}
}
}
if (ic->mode == 'J' && likely(dio->op == REQ_OP_DISCARD) && !discard_retried) {
sector_t next_sector;
unsigned int new_pos;
new_pos = find_journal_node(ic, dio->range.logical_sector, &next_sector);
if (unlikely(new_pos != NOT_FOUND) ||
unlikely(next_sector < dio->range.logical_sector - dio->range.n_sectors)) {
remove_range_unlocked(ic, &dio->range);
spin_unlock_irq(&ic->endio_wait.lock);
queue_work(ic->commit_wq, &ic->commit_work);
flush_workqueue(ic->commit_wq);
queue_work(ic->writer_wq, &ic->writer_work);
flush_workqueue(ic->writer_wq);
discard_retried = true;
goto lock_retry;
}
}
spin_unlock_irq(&ic->endio_wait.lock);
if (unlikely(journal_read_pos != NOT_FOUND)) {
journal_section = journal_read_pos / ic->journal_section_entries;
journal_entry = journal_read_pos % ic->journal_section_entries;
goto journal_read_write;
}
if (ic->mode == 'B' && (dio->op == REQ_OP_WRITE || unlikely(dio->op == REQ_OP_DISCARD))) {
if (!block_bitmap_op(ic, ic->may_write_bitmap, dio->range.logical_sector,
dio->range.n_sectors, BITMAP_OP_TEST_ALL_SET)) {
struct bitmap_block_status *bbs;
bbs = sector_to_bitmap_block(ic, dio->range.logical_sector);
spin_lock(&bbs->bio_queue_lock);
bio_list_add(&bbs->bio_queue, bio);
spin_unlock(&bbs->bio_queue_lock);
queue_work(ic->writer_wq, &bbs->work);
return;
}
}
dio->in_flight = (atomic_t)ATOMIC_INIT(2);
if (need_sync_io) {
init_completion(&read_comp);
dio->completion = &read_comp;
} else
dio->completion = NULL;
dm_bio_record(&dio->bio_details, bio);
bio_set_dev(bio, ic->dev->bdev);
bio->bi_integrity = NULL;
bio->bi_opf &= ~REQ_INTEGRITY;
bio->bi_end_io = integrity_end_io;
bio->bi_iter.bi_size = dio->range.n_sectors << SECTOR_SHIFT;
if (unlikely(dio->op == REQ_OP_DISCARD) && likely(ic->mode != 'D')) {
integrity_metadata(&dio->work);
dm_integrity_flush_buffers(ic, false);
dio->in_flight = (atomic_t)ATOMIC_INIT(1);
dio->completion = NULL;
submit_bio_noacct(bio);
return;
}
submit_bio_noacct(bio);
if (need_sync_io) {
wait_for_completion_io(&read_comp);
if (ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING) &&
dio->range.logical_sector + dio->range.n_sectors > le64_to_cpu(ic->sb->recalc_sector))
goto skip_check;
if (ic->mode == 'B') {
if (!block_bitmap_op(ic, ic->recalc_bitmap, dio->range.logical_sector,
dio->range.n_sectors, BITMAP_OP_TEST_ALL_CLEAR))
goto skip_check;
}
if (likely(!bio->bi_status))
integrity_metadata(&dio->work);
else
skip_check:
dec_in_flight(dio);
} else {
INIT_WORK(&dio->work, integrity_metadata);
queue_work(ic->metadata_wq, &dio->work);
}
return;
journal_read_write:
if (unlikely(__journal_read_write(dio, bio, journal_section, journal_entry)))
goto lock_retry;
do_endio_flush(ic, dio);
}
static void integrity_bio_wait(struct work_struct *w)
{
struct dm_integrity_io *dio = container_of(w, struct dm_integrity_io, work);
dm_integrity_map_continue(dio, false);
}
static void pad_uncommitted(struct dm_integrity_c *ic)
{
if (ic->free_section_entry) {
ic->free_sectors -= ic->journal_section_entries - ic->free_section_entry;
ic->free_section_entry = 0;
ic->free_section++;
wraparound_section(ic, &ic->free_section);
ic->n_uncommitted_sections++;
}
if (WARN_ON(ic->journal_sections * ic->journal_section_entries !=
(ic->n_uncommitted_sections + ic->n_committed_sections) *
ic->journal_section_entries + ic->free_sectors)) {
DMCRIT("journal_sections %u, journal_section_entries %u, "
"n_uncommitted_sections %u, n_committed_sections %u, "
"journal_section_entries %u, free_sectors %u",
ic->journal_sections, ic->journal_section_entries,
ic->n_uncommitted_sections, ic->n_committed_sections,
ic->journal_section_entries, ic->free_sectors);
}
}
static void integrity_commit(struct work_struct *w)
{
struct dm_integrity_c *ic = container_of(w, struct dm_integrity_c, commit_work);
unsigned int commit_start, commit_sections;
unsigned int i, j, n;
struct bio *flushes;
del_timer(&ic->autocommit_timer);
spin_lock_irq(&ic->endio_wait.lock);
flushes = bio_list_get(&ic->flush_bio_list);
if (unlikely(ic->mode != 'J')) {
spin_unlock_irq(&ic->endio_wait.lock);
dm_integrity_flush_buffers(ic, true);
goto release_flush_bios;
}
pad_uncommitted(ic);
commit_start = ic->uncommitted_section;
commit_sections = ic->n_uncommitted_sections;
spin_unlock_irq(&ic->endio_wait.lock);
if (!commit_sections)
goto release_flush_bios;
ic->wrote_to_journal = true;
i = commit_start;
for (n = 0; n < commit_sections; n++) {
for (j = 0; j < ic->journal_section_entries; j++) {
struct journal_entry *je;
je = access_journal_entry(ic, i, j);
io_wait_event(ic->copy_to_journal_wait, !journal_entry_is_inprogress(je));
}
for (j = 0; j < ic->journal_section_sectors; j++) {
struct journal_sector *js;
js = access_journal(ic, i, j);
js->commit_id = dm_integrity_commit_id(ic, i, j, ic->commit_seq);
}
i++;
if (unlikely(i >= ic->journal_sections))
ic->commit_seq = next_commit_seq(ic->commit_seq);
wraparound_section(ic, &i);
}
smp_rmb();
write_journal(ic, commit_start, commit_sections);
spin_lock_irq(&ic->endio_wait.lock);
ic->uncommitted_section += commit_sections;
wraparound_section(ic, &ic->uncommitted_section);
ic->n_uncommitted_sections -= commit_sections;
ic->n_committed_sections += commit_sections;
spin_unlock_irq(&ic->endio_wait.lock);
if (READ_ONCE(ic->free_sectors) <= ic->free_sectors_threshold)
queue_work(ic->writer_wq, &ic->writer_work);
release_flush_bios:
while (flushes) {
struct bio *next = flushes->bi_next;
flushes->bi_next = NULL;
do_endio(ic, flushes);
flushes = next;
}
}
static void complete_copy_from_journal(unsigned long error, void *context)
{
struct journal_io *io = context;
struct journal_completion *comp = io->comp;
struct dm_integrity_c *ic = comp->ic;
remove_range(ic, &io->range);
mempool_free(io, &ic->journal_io_mempool);
if (unlikely(error != 0))
dm_integrity_io_error(ic, "copying from journal", -EIO);
complete_journal_op(comp);
}
static void restore_last_bytes(struct dm_integrity_c *ic, struct journal_sector *js,
struct journal_entry *je)
{
unsigned int s = 0;
do {
js->commit_id = je->last_bytes[s];
js++;
} while (++s < ic->sectors_per_block);
}
static void do_journal_write(struct dm_integrity_c *ic, unsigned int write_start,
unsigned int write_sections, bool from_replay)
{
unsigned int i, j, n;
struct journal_completion comp;
struct blk_plug plug;
blk_start_plug(&plug);
comp.ic = ic;
comp.in_flight = (atomic_t)ATOMIC_INIT(1);
init_completion(&comp.comp);
i = write_start;
for (n = 0; n < write_sections; n++, i++, wraparound_section(ic, &i)) {
#ifndef INTERNAL_VERIFY
if (unlikely(from_replay))
#endif
rw_section_mac(ic, i, false);
for (j = 0; j < ic->journal_section_entries; j++) {
struct journal_entry *je = access_journal_entry(ic, i, j);
sector_t sec, area, offset;
unsigned int k, l, next_loop;
sector_t metadata_block;
unsigned int metadata_offset;
struct journal_io *io;
if (journal_entry_is_unused(je))
continue;
BUG_ON(unlikely(journal_entry_is_inprogress(je)) && !from_replay);
sec = journal_entry_get_sector(je);
if (unlikely(from_replay)) {
if (unlikely(sec & (unsigned int)(ic->sectors_per_block - 1))) {
dm_integrity_io_error(ic, "invalid sector in journal", -EIO);
sec &= ~(sector_t)(ic->sectors_per_block - 1);
}
if (unlikely(sec >= ic->provided_data_sectors)) {
journal_entry_set_unused(je);
continue;
}
}
get_area_and_offset(ic, sec, &area, &offset);
restore_last_bytes(ic, access_journal_data(ic, i, j), je);
for (k = j + 1; k < ic->journal_section_entries; k++) {
struct journal_entry *je2 = access_journal_entry(ic, i, k);
sector_t sec2, area2, offset2;
if (journal_entry_is_unused(je2))
break;
BUG_ON(unlikely(journal_entry_is_inprogress(je2)) && !from_replay);
sec2 = journal_entry_get_sector(je2);
if (unlikely(sec2 >= ic->provided_data_sectors))
break;
get_area_and_offset(ic, sec2, &area2, &offset2);
if (area2 != area || offset2 != offset + ((k - j) << ic->sb->log2_sectors_per_block))
break;
restore_last_bytes(ic, access_journal_data(ic, i, k), je2);
}
next_loop = k - 1;
io = mempool_alloc(&ic->journal_io_mempool, GFP_NOIO);
io->comp = ∁
io->range.logical_sector = sec;
io->range.n_sectors = (k - j) << ic->sb->log2_sectors_per_block;
spin_lock_irq(&ic->endio_wait.lock);
add_new_range_and_wait(ic, &io->range);
if (likely(!from_replay)) {
struct journal_node *section_node = &ic->journal_tree[i * ic->journal_section_entries];
/* don't write if there is newer committed sector */
while (j < k && find_newer_committed_node(ic, §ion_node[j])) {
struct journal_entry *je2 = access_journal_entry(ic, i, j);
journal_entry_set_unused(je2);
remove_journal_node(ic, §ion_node[j]);
j++;
sec += ic->sectors_per_block;
offset += ic->sectors_per_block;
}
while (j < k && find_newer_committed_node(ic, §ion_node[k - 1])) {
struct journal_entry *je2 = access_journal_entry(ic, i, k - 1);
journal_entry_set_unused(je2);
remove_journal_node(ic, §ion_node[k - 1]);
k--;
}
if (j == k) {
remove_range_unlocked(ic, &io->range);
spin_unlock_irq(&ic->endio_wait.lock);
mempool_free(io, &ic->journal_io_mempool);
goto skip_io;
}
for (l = j; l < k; l++)
remove_journal_node(ic, §ion_node[l]);
}
spin_unlock_irq(&ic->endio_wait.lock);
metadata_block = get_metadata_sector_and_offset(ic, area, offset, &metadata_offset);
for (l = j; l < k; l++) {
int r;
struct journal_entry *je2 = access_journal_entry(ic, i, l);
if (
#ifndef INTERNAL_VERIFY
unlikely(from_replay) &&
#endif
ic->internal_hash) {
char test_tag[max_t(size_t, HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)];
integrity_sector_checksum(ic, sec + ((l - j) << ic->sb->log2_sectors_per_block),
(char *)access_journal_data(ic, i, l), test_tag);
if (unlikely(memcmp(test_tag, journal_entry_tag(ic, je2), ic->tag_size))) {
dm_integrity_io_error(ic, "tag mismatch when replaying journal", -EILSEQ);
dm_audit_log_target(DM_MSG_PREFIX, "integrity-replay-journal", ic->ti, 0);
}
}
journal_entry_set_unused(je2);
r = dm_integrity_rw_tag(ic, journal_entry_tag(ic, je2), &metadata_block, &metadata_offset,
ic->tag_size, TAG_WRITE);
if (unlikely(r))
dm_integrity_io_error(ic, "reading tags", r);
}
atomic_inc(&comp.in_flight);
copy_from_journal(ic, i, j << ic->sb->log2_sectors_per_block,
(k - j) << ic->sb->log2_sectors_per_block,
get_data_sector(ic, area, offset),
complete_copy_from_journal, io);
skip_io:
j = next_loop;
}
}
dm_bufio_write_dirty_buffers_async(ic->bufio);
blk_finish_plug(&plug);
complete_journal_op(&comp);
wait_for_completion_io(&comp.comp);
dm_integrity_flush_buffers(ic, true);
}
static void integrity_writer(struct work_struct *w)
{
struct dm_integrity_c *ic = container_of(w, struct dm_integrity_c, writer_work);
unsigned int write_start, write_sections;
unsigned int prev_free_sectors;
spin_lock_irq(&ic->endio_wait.lock);
write_start = ic->committed_section;
write_sections = ic->n_committed_sections;
spin_unlock_irq(&ic->endio_wait.lock);
if (!write_sections)
return;
do_journal_write(ic, write_start, write_sections, false);
spin_lock_irq(&ic->endio_wait.lock);
ic->committed_section += write_sections;
wraparound_section(ic, &ic->committed_section);
ic->n_committed_sections -= write_sections;
prev_free_sectors = ic->free_sectors;
ic->free_sectors += write_sections * ic->journal_section_entries;
if (unlikely(!prev_free_sectors))
wake_up_locked(&ic->endio_wait);
spin_unlock_irq(&ic->endio_wait.lock);
}
static void recalc_write_super(struct dm_integrity_c *ic)
{
int r;
dm_integrity_flush_buffers(ic, false);
if (dm_integrity_failed(ic))
return;
r = sync_rw_sb(ic, REQ_OP_WRITE);
if (unlikely(r))
dm_integrity_io_error(ic, "writing superblock", r);
}
static void integrity_recalc(struct work_struct *w)
{
struct dm_integrity_c *ic = container_of(w, struct dm_integrity_c, recalc_work);
size_t recalc_tags_size;
u8 *recalc_buffer = NULL;
u8 *recalc_tags = NULL;
struct dm_integrity_range range;
struct dm_io_request io_req;
struct dm_io_region io_loc;
sector_t area, offset;
sector_t metadata_block;
unsigned int metadata_offset;
sector_t logical_sector, n_sectors;
__u8 *t;
unsigned int i;
int r;
unsigned int super_counter = 0;
unsigned recalc_sectors = RECALC_SECTORS;
retry:
recalc_buffer = __vmalloc(recalc_sectors << SECTOR_SHIFT, GFP_NOIO);
if (!recalc_buffer) {
oom:
recalc_sectors >>= 1;
if (recalc_sectors >= 1U << ic->sb->log2_sectors_per_block)
goto retry;
DMCRIT("out of memory for recalculate buffer - recalculation disabled");
goto free_ret;
}
recalc_tags_size = (recalc_sectors >> ic->sb->log2_sectors_per_block) * ic->tag_size;
if (crypto_shash_digestsize(ic->internal_hash) > ic->tag_size)
recalc_tags_size += crypto_shash_digestsize(ic->internal_hash) - ic->tag_size;
recalc_tags = kvmalloc(recalc_tags_size, GFP_NOIO);
if (!recalc_tags) {
vfree(recalc_buffer);
recalc_buffer = NULL;
goto oom;
}
DEBUG_print("start recalculation... (position %llx)\n", le64_to_cpu(ic->sb->recalc_sector));
spin_lock_irq(&ic->endio_wait.lock);
next_chunk:
if (unlikely(dm_post_suspending(ic->ti)))
goto unlock_ret;
range.logical_sector = le64_to_cpu(ic->sb->recalc_sector);
if (unlikely(range.logical_sector >= ic->provided_data_sectors)) {
if (ic->mode == 'B') {
block_bitmap_op(ic, ic->recalc_bitmap, 0, ic->provided_data_sectors, BITMAP_OP_CLEAR);
DEBUG_print("queue_delayed_work: bitmap_flush_work\n");
queue_delayed_work(ic->commit_wq, &ic->bitmap_flush_work, 0);
}
goto unlock_ret;
}
get_area_and_offset(ic, range.logical_sector, &area, &offset);
range.n_sectors = min((sector_t)recalc_sectors, ic->provided_data_sectors - range.logical_sector);
if (!ic->meta_dev)
range.n_sectors = min(range.n_sectors, ((sector_t)1U << ic->sb->log2_interleave_sectors) - (unsigned int)offset);
add_new_range_and_wait(ic, &range);
spin_unlock_irq(&ic->endio_wait.lock);
logical_sector = range.logical_sector;
n_sectors = range.n_sectors;
if (ic->mode == 'B') {
if (block_bitmap_op(ic, ic->recalc_bitmap, logical_sector, n_sectors, BITMAP_OP_TEST_ALL_CLEAR))
goto advance_and_next;
while (block_bitmap_op(ic, ic->recalc_bitmap, logical_sector,
ic->sectors_per_block, BITMAP_OP_TEST_ALL_CLEAR)) {
logical_sector += ic->sectors_per_block;
n_sectors -= ic->sectors_per_block;
cond_resched();
}
while (block_bitmap_op(ic, ic->recalc_bitmap, logical_sector + n_sectors - ic->sectors_per_block,
ic->sectors_per_block, BITMAP_OP_TEST_ALL_CLEAR)) {
n_sectors -= ic->sectors_per_block;
cond_resched();
}
get_area_and_offset(ic, logical_sector, &area, &offset);
}
DEBUG_print("recalculating: %llx, %llx\n", logical_sector, n_sectors);
if (unlikely(++super_counter == RECALC_WRITE_SUPER)) {
recalc_write_super(ic);
if (ic->mode == 'B')
queue_delayed_work(ic->commit_wq, &ic->bitmap_flush_work, ic->bitmap_flush_interval);
super_counter = 0;
}
if (unlikely(dm_integrity_failed(ic)))
goto err;
io_req.bi_opf = REQ_OP_READ;
io_req.mem.type = DM_IO_VMA;
io_req.mem.ptr.addr = recalc_buffer;
io_req.notify.fn = NULL;
io_req.client = ic->io;
io_loc.bdev = ic->dev->bdev;
io_loc.sector = get_data_sector(ic, area, offset);
io_loc.count = n_sectors;
r = dm_io(&io_req, 1, &io_loc, NULL);
if (unlikely(r)) {
dm_integrity_io_error(ic, "reading data", r);
goto err;
}
t = recalc_tags;
for (i = 0; i < n_sectors; i += ic->sectors_per_block) {
integrity_sector_checksum(ic, logical_sector + i, recalc_buffer + (i << SECTOR_SHIFT), t);
t += ic->tag_size;
}
metadata_block = get_metadata_sector_and_offset(ic, area, offset, &metadata_offset);
r = dm_integrity_rw_tag(ic, recalc_tags, &metadata_block, &metadata_offset, t - recalc_tags, TAG_WRITE);
if (unlikely(r)) {
dm_integrity_io_error(ic, "writing tags", r);
goto err;
}
if (ic->mode == 'B') {
sector_t start, end;
start = (range.logical_sector >>
(ic->sb->log2_sectors_per_block + ic->log2_blocks_per_bitmap_bit)) <<
(ic->sb->log2_sectors_per_block + ic->log2_blocks_per_bitmap_bit);
end = ((range.logical_sector + range.n_sectors) >>
(ic->sb->log2_sectors_per_block + ic->log2_blocks_per_bitmap_bit)) <<
(ic->sb->log2_sectors_per_block + ic->log2_blocks_per_bitmap_bit);
block_bitmap_op(ic, ic->recalc_bitmap, start, end - start, BITMAP_OP_CLEAR);
}
advance_and_next:
cond_resched();
spin_lock_irq(&ic->endio_wait.lock);
remove_range_unlocked(ic, &range);
ic->sb->recalc_sector = cpu_to_le64(range.logical_sector + range.n_sectors);
goto next_chunk;
err:
remove_range(ic, &range);
goto free_ret;
unlock_ret:
spin_unlock_irq(&ic->endio_wait.lock);
recalc_write_super(ic);
free_ret:
vfree(recalc_buffer);
kvfree(recalc_tags);
}
static void bitmap_block_work(struct work_struct *w)
{
struct bitmap_block_status *bbs = container_of(w, struct bitmap_block_status, work);
struct dm_integrity_c *ic = bbs->ic;
struct bio *bio;
struct bio_list bio_queue;
struct bio_list waiting;
bio_list_init(&waiting);
spin_lock(&bbs->bio_queue_lock);
bio_queue = bbs->bio_queue;
bio_list_init(&bbs->bio_queue);
spin_unlock(&bbs->bio_queue_lock);
while ((bio = bio_list_pop(&bio_queue))) {
struct dm_integrity_io *dio;
dio = dm_per_bio_data(bio, sizeof(struct dm_integrity_io));
if (block_bitmap_op(ic, ic->may_write_bitmap, dio->range.logical_sector,
dio->range.n_sectors, BITMAP_OP_TEST_ALL_SET)) {
remove_range(ic, &dio->range);
INIT_WORK(&dio->work, integrity_bio_wait);
queue_work(ic->offload_wq, &dio->work);
} else {
block_bitmap_op(ic, ic->journal, dio->range.logical_sector,
dio->range.n_sectors, BITMAP_OP_SET);
bio_list_add(&waiting, bio);
}
}
if (bio_list_empty(&waiting))
return;
rw_journal_sectors(ic, REQ_OP_WRITE | REQ_FUA | REQ_SYNC,
bbs->idx * (BITMAP_BLOCK_SIZE >> SECTOR_SHIFT),
BITMAP_BLOCK_SIZE >> SECTOR_SHIFT, NULL);
while ((bio = bio_list_pop(&waiting))) {
struct dm_integrity_io *dio = dm_per_bio_data(bio, sizeof(struct dm_integrity_io));
block_bitmap_op(ic, ic->may_write_bitmap, dio->range.logical_sector,
dio->range.n_sectors, BITMAP_OP_SET);
remove_range(ic, &dio->range);
INIT_WORK(&dio->work, integrity_bio_wait);
queue_work(ic->offload_wq, &dio->work);
}
queue_delayed_work(ic->commit_wq, &ic->bitmap_flush_work, ic->bitmap_flush_interval);
}
static void bitmap_flush_work(struct work_struct *work)
{
struct dm_integrity_c *ic = container_of(work, struct dm_integrity_c, bitmap_flush_work.work);
struct dm_integrity_range range;
unsigned long limit;
struct bio *bio;
dm_integrity_flush_buffers(ic, false);
range.logical_sector = 0;
range.n_sectors = ic->provided_data_sectors;
spin_lock_irq(&ic->endio_wait.lock);
add_new_range_and_wait(ic, &range);
spin_unlock_irq(&ic->endio_wait.lock);
dm_integrity_flush_buffers(ic, true);
limit = ic->provided_data_sectors;
if (ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING)) {
limit = le64_to_cpu(ic->sb->recalc_sector)
>> (ic->sb->log2_sectors_per_block + ic->log2_blocks_per_bitmap_bit)
<< (ic->sb->log2_sectors_per_block + ic->log2_blocks_per_bitmap_bit);
}
/*DEBUG_print("zeroing journal\n");*/
block_bitmap_op(ic, ic->journal, 0, limit, BITMAP_OP_CLEAR);
block_bitmap_op(ic, ic->may_write_bitmap, 0, limit, BITMAP_OP_CLEAR);
rw_journal_sectors(ic, REQ_OP_WRITE | REQ_FUA | REQ_SYNC, 0,
ic->n_bitmap_blocks * (BITMAP_BLOCK_SIZE >> SECTOR_SHIFT), NULL);
spin_lock_irq(&ic->endio_wait.lock);
remove_range_unlocked(ic, &range);
while (unlikely((bio = bio_list_pop(&ic->synchronous_bios)) != NULL)) {
bio_endio(bio);
spin_unlock_irq(&ic->endio_wait.lock);
spin_lock_irq(&ic->endio_wait.lock);
}
spin_unlock_irq(&ic->endio_wait.lock);
}
static void init_journal(struct dm_integrity_c *ic, unsigned int start_section,
unsigned int n_sections, unsigned char commit_seq)
{
unsigned int i, j, n;
if (!n_sections)
return;
for (n = 0; n < n_sections; n++) {
i = start_section + n;
wraparound_section(ic, &i);
for (j = 0; j < ic->journal_section_sectors; j++) {
struct journal_sector *js = access_journal(ic, i, j);
BUILD_BUG_ON(sizeof(js->sectors) != JOURNAL_SECTOR_DATA);
memset(&js->sectors, 0, sizeof(js->sectors));
js->commit_id = dm_integrity_commit_id(ic, i, j, commit_seq);
}
for (j = 0; j < ic->journal_section_entries; j++) {
struct journal_entry *je = access_journal_entry(ic, i, j);
journal_entry_set_unused(je);
}
}
write_journal(ic, start_section, n_sections);
}
static int find_commit_seq(struct dm_integrity_c *ic, unsigned int i, unsigned int j, commit_id_t id)
{
unsigned char k;
for (k = 0; k < N_COMMIT_IDS; k++) {
if (dm_integrity_commit_id(ic, i, j, k) == id)
return k;
}
dm_integrity_io_error(ic, "journal commit id", -EIO);
return -EIO;
}
static void replay_journal(struct dm_integrity_c *ic)
{
unsigned int i, j;
bool used_commit_ids[N_COMMIT_IDS];
unsigned int max_commit_id_sections[N_COMMIT_IDS];
unsigned int write_start, write_sections;
unsigned int continue_section;
bool journal_empty;
unsigned char unused, last_used, want_commit_seq;
if (ic->mode == 'R')
return;
if (ic->journal_uptodate)
return;
last_used = 0;
write_start = 0;
if (!ic->just_formatted) {
DEBUG_print("reading journal\n");
rw_journal(ic, REQ_OP_READ, 0, ic->journal_sections, NULL);
if (ic->journal_io)
DEBUG_bytes(lowmem_page_address(ic->journal_io[0].page), 64, "read journal");
if (ic->journal_io) {
struct journal_completion crypt_comp;
crypt_comp.ic = ic;
init_completion(&crypt_comp.comp);
crypt_comp.in_flight = (atomic_t)ATOMIC_INIT(0);
encrypt_journal(ic, false, 0, ic->journal_sections, &crypt_comp);
wait_for_completion(&crypt_comp.comp);
}
DEBUG_bytes(lowmem_page_address(ic->journal[0].page), 64, "decrypted journal");
}
if (dm_integrity_failed(ic))
goto clear_journal;
journal_empty = true;
memset(used_commit_ids, 0, sizeof(used_commit_ids));
memset(max_commit_id_sections, 0, sizeof(max_commit_id_sections));
for (i = 0; i < ic->journal_sections; i++) {
for (j = 0; j < ic->journal_section_sectors; j++) {
int k;
struct journal_sector *js = access_journal(ic, i, j);
k = find_commit_seq(ic, i, j, js->commit_id);
if (k < 0)
goto clear_journal;
used_commit_ids[k] = true;
max_commit_id_sections[k] = i;
}
if (journal_empty) {
for (j = 0; j < ic->journal_section_entries; j++) {
struct journal_entry *je = access_journal_entry(ic, i, j);
if (!journal_entry_is_unused(je)) {
journal_empty = false;
break;
}
}
}
}
if (!used_commit_ids[N_COMMIT_IDS - 1]) {
unused = N_COMMIT_IDS - 1;
while (unused && !used_commit_ids[unused - 1])
unused--;
} else {
for (unused = 0; unused < N_COMMIT_IDS; unused++)
if (!used_commit_ids[unused])
break;
if (unused == N_COMMIT_IDS) {
dm_integrity_io_error(ic, "journal commit ids", -EIO);
goto clear_journal;
}
}
DEBUG_print("first unused commit seq %d [%d,%d,%d,%d]\n",
unused, used_commit_ids[0], used_commit_ids[1],
used_commit_ids[2], used_commit_ids[3]);
last_used = prev_commit_seq(unused);
want_commit_seq = prev_commit_seq(last_used);
if (!used_commit_ids[want_commit_seq] && used_commit_ids[prev_commit_seq(want_commit_seq)])
journal_empty = true;
write_start = max_commit_id_sections[last_used] + 1;
if (unlikely(write_start >= ic->journal_sections))
want_commit_seq = next_commit_seq(want_commit_seq);
wraparound_section(ic, &write_start);
i = write_start;
for (write_sections = 0; write_sections < ic->journal_sections; write_sections++) {
for (j = 0; j < ic->journal_section_sectors; j++) {
struct journal_sector *js = access_journal(ic, i, j);
if (js->commit_id != dm_integrity_commit_id(ic, i, j, want_commit_seq)) {
/*
* This could be caused by crash during writing.
* We won't replay the inconsistent part of the
* journal.
*/
DEBUG_print("commit id mismatch at position (%u, %u): %d != %d\n",
i, j, find_commit_seq(ic, i, j, js->commit_id), want_commit_seq);
goto brk;
}
}
i++;
if (unlikely(i >= ic->journal_sections))
want_commit_seq = next_commit_seq(want_commit_seq);
wraparound_section(ic, &i);
}
brk:
if (!journal_empty) {
DEBUG_print("replaying %u sections, starting at %u, commit seq %d\n",
write_sections, write_start, want_commit_seq);
do_journal_write(ic, write_start, write_sections, true);
}
if (write_sections == ic->journal_sections && (ic->mode == 'J' || journal_empty)) {
continue_section = write_start;
ic->commit_seq = want_commit_seq;
DEBUG_print("continuing from section %u, commit seq %d\n", write_start, ic->commit_seq);
} else {
unsigned int s;
unsigned char erase_seq;
clear_journal:
DEBUG_print("clearing journal\n");
erase_seq = prev_commit_seq(prev_commit_seq(last_used));
s = write_start;
init_journal(ic, s, 1, erase_seq);
s++;
wraparound_section(ic, &s);
if (ic->journal_sections >= 2) {
init_journal(ic, s, ic->journal_sections - 2, erase_seq);
s += ic->journal_sections - 2;
wraparound_section(ic, &s);
init_journal(ic, s, 1, erase_seq);
}
continue_section = 0;
ic->commit_seq = next_commit_seq(erase_seq);
}
ic->committed_section = continue_section;
ic->n_committed_sections = 0;
ic->uncommitted_section = continue_section;
ic->n_uncommitted_sections = 0;
ic->free_section = continue_section;
ic->free_section_entry = 0;
ic->free_sectors = ic->journal_entries;
ic->journal_tree_root = RB_ROOT;
for (i = 0; i < ic->journal_entries; i++)
init_journal_node(&ic->journal_tree[i]);
}
static void dm_integrity_enter_synchronous_mode(struct dm_integrity_c *ic)
{
DEBUG_print("%s\n", __func__);
if (ic->mode == 'B') {
ic->bitmap_flush_interval = msecs_to_jiffies(10) + 1;
ic->synchronous_mode = 1;
cancel_delayed_work_sync(&ic->bitmap_flush_work);
queue_delayed_work(ic->commit_wq, &ic->bitmap_flush_work, 0);
flush_workqueue(ic->commit_wq);
}
}
static int dm_integrity_reboot(struct notifier_block *n, unsigned long code, void *x)
{
struct dm_integrity_c *ic = container_of(n, struct dm_integrity_c, reboot_notifier);
DEBUG_print("%s\n", __func__);
dm_integrity_enter_synchronous_mode(ic);
return NOTIFY_DONE;
}
static void dm_integrity_postsuspend(struct dm_target *ti)
{
struct dm_integrity_c *ic = ti->private;
int r;
WARN_ON(unregister_reboot_notifier(&ic->reboot_notifier));
del_timer_sync(&ic->autocommit_timer);
if (ic->recalc_wq)
drain_workqueue(ic->recalc_wq);
if (ic->mode == 'B')
cancel_delayed_work_sync(&ic->bitmap_flush_work);
queue_work(ic->commit_wq, &ic->commit_work);
drain_workqueue(ic->commit_wq);
if (ic->mode == 'J') {
queue_work(ic->writer_wq, &ic->writer_work);
drain_workqueue(ic->writer_wq);
dm_integrity_flush_buffers(ic, true);
if (ic->wrote_to_journal) {
init_journal(ic, ic->free_section,
ic->journal_sections - ic->free_section, ic->commit_seq);
if (ic->free_section) {
init_journal(ic, 0, ic->free_section,
next_commit_seq(ic->commit_seq));
}
}
}
if (ic->mode == 'B') {
dm_integrity_flush_buffers(ic, true);
#if 1
/* set to 0 to test bitmap replay code */
init_journal(ic, 0, ic->journal_sections, 0);
ic->sb->flags &= ~cpu_to_le32(SB_FLAG_DIRTY_BITMAP);
r = sync_rw_sb(ic, REQ_OP_WRITE | REQ_FUA);
if (unlikely(r))
dm_integrity_io_error(ic, "writing superblock", r);
#endif
}
BUG_ON(!RB_EMPTY_ROOT(&ic->in_progress));
ic->journal_uptodate = true;
}
static void dm_integrity_resume(struct dm_target *ti)
{
struct dm_integrity_c *ic = ti->private;
__u64 old_provided_data_sectors = le64_to_cpu(ic->sb->provided_data_sectors);
int r;
DEBUG_print("resume\n");
ic->wrote_to_journal = false;
if (ic->provided_data_sectors != old_provided_data_sectors) {
if (ic->provided_data_sectors > old_provided_data_sectors &&
ic->mode == 'B' &&
ic->sb->log2_blocks_per_bitmap_bit == ic->log2_blocks_per_bitmap_bit) {
rw_journal_sectors(ic, REQ_OP_READ, 0,
ic->n_bitmap_blocks * (BITMAP_BLOCK_SIZE >> SECTOR_SHIFT), NULL);
block_bitmap_op(ic, ic->journal, old_provided_data_sectors,
ic->provided_data_sectors - old_provided_data_sectors, BITMAP_OP_SET);
rw_journal_sectors(ic, REQ_OP_WRITE | REQ_FUA | REQ_SYNC, 0,
ic->n_bitmap_blocks * (BITMAP_BLOCK_SIZE >> SECTOR_SHIFT), NULL);
}
ic->sb->provided_data_sectors = cpu_to_le64(ic->provided_data_sectors);
r = sync_rw_sb(ic, REQ_OP_WRITE | REQ_FUA);
if (unlikely(r))
dm_integrity_io_error(ic, "writing superblock", r);
}
if (ic->sb->flags & cpu_to_le32(SB_FLAG_DIRTY_BITMAP)) {
DEBUG_print("resume dirty_bitmap\n");
rw_journal_sectors(ic, REQ_OP_READ, 0,
ic->n_bitmap_blocks * (BITMAP_BLOCK_SIZE >> SECTOR_SHIFT), NULL);
if (ic->mode == 'B') {
if (ic->sb->log2_blocks_per_bitmap_bit == ic->log2_blocks_per_bitmap_bit &&
!ic->reset_recalculate_flag) {
block_bitmap_copy(ic, ic->recalc_bitmap, ic->journal);
block_bitmap_copy(ic, ic->may_write_bitmap, ic->journal);
if (!block_bitmap_op(ic, ic->journal, 0, ic->provided_data_sectors,
BITMAP_OP_TEST_ALL_CLEAR)) {
ic->sb->flags |= cpu_to_le32(SB_FLAG_RECALCULATING);
ic->sb->recalc_sector = cpu_to_le64(0);
}
} else {
DEBUG_print("non-matching blocks_per_bitmap_bit: %u, %u\n",
ic->sb->log2_blocks_per_bitmap_bit, ic->log2_blocks_per_bitmap_bit);
ic->sb->log2_blocks_per_bitmap_bit = ic->log2_blocks_per_bitmap_bit;
block_bitmap_op(ic, ic->recalc_bitmap, 0, ic->provided_data_sectors, BITMAP_OP_SET);
block_bitmap_op(ic, ic->may_write_bitmap, 0, ic->provided_data_sectors, BITMAP_OP_SET);
block_bitmap_op(ic, ic->journal, 0, ic->provided_data_sectors, BITMAP_OP_SET);
rw_journal_sectors(ic, REQ_OP_WRITE | REQ_FUA | REQ_SYNC, 0,
ic->n_bitmap_blocks * (BITMAP_BLOCK_SIZE >> SECTOR_SHIFT), NULL);
ic->sb->flags |= cpu_to_le32(SB_FLAG_RECALCULATING);
ic->sb->recalc_sector = cpu_to_le64(0);
}
} else {
if (!(ic->sb->log2_blocks_per_bitmap_bit == ic->log2_blocks_per_bitmap_bit &&
block_bitmap_op(ic, ic->journal, 0, ic->provided_data_sectors, BITMAP_OP_TEST_ALL_CLEAR)) ||
ic->reset_recalculate_flag) {
ic->sb->flags |= cpu_to_le32(SB_FLAG_RECALCULATING);
ic->sb->recalc_sector = cpu_to_le64(0);
}
init_journal(ic, 0, ic->journal_sections, 0);
replay_journal(ic);
ic->sb->flags &= ~cpu_to_le32(SB_FLAG_DIRTY_BITMAP);
}
r = sync_rw_sb(ic, REQ_OP_WRITE | REQ_FUA);
if (unlikely(r))
dm_integrity_io_error(ic, "writing superblock", r);
} else {
replay_journal(ic);
if (ic->reset_recalculate_flag) {
ic->sb->flags |= cpu_to_le32(SB_FLAG_RECALCULATING);
ic->sb->recalc_sector = cpu_to_le64(0);
}
if (ic->mode == 'B') {
ic->sb->flags |= cpu_to_le32(SB_FLAG_DIRTY_BITMAP);
ic->sb->log2_blocks_per_bitmap_bit = ic->log2_blocks_per_bitmap_bit;
r = sync_rw_sb(ic, REQ_OP_WRITE | REQ_FUA);
if (unlikely(r))
dm_integrity_io_error(ic, "writing superblock", r);
block_bitmap_op(ic, ic->journal, 0, ic->provided_data_sectors, BITMAP_OP_CLEAR);
block_bitmap_op(ic, ic->recalc_bitmap, 0, ic->provided_data_sectors, BITMAP_OP_CLEAR);
block_bitmap_op(ic, ic->may_write_bitmap, 0, ic->provided_data_sectors, BITMAP_OP_CLEAR);
if (ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING) &&
le64_to_cpu(ic->sb->recalc_sector) < ic->provided_data_sectors) {
block_bitmap_op(ic, ic->journal, le64_to_cpu(ic->sb->recalc_sector),
ic->provided_data_sectors - le64_to_cpu(ic->sb->recalc_sector), BITMAP_OP_SET);
block_bitmap_op(ic, ic->recalc_bitmap, le64_to_cpu(ic->sb->recalc_sector),
ic->provided_data_sectors - le64_to_cpu(ic->sb->recalc_sector), BITMAP_OP_SET);
block_bitmap_op(ic, ic->may_write_bitmap, le64_to_cpu(ic->sb->recalc_sector),
ic->provided_data_sectors - le64_to_cpu(ic->sb->recalc_sector), BITMAP_OP_SET);
}
rw_journal_sectors(ic, REQ_OP_WRITE | REQ_FUA | REQ_SYNC, 0,
ic->n_bitmap_blocks * (BITMAP_BLOCK_SIZE >> SECTOR_SHIFT), NULL);
}
}
DEBUG_print("testing recalc: %x\n", ic->sb->flags);
if (ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING)) {
__u64 recalc_pos = le64_to_cpu(ic->sb->recalc_sector);
DEBUG_print("recalc pos: %llx / %llx\n", recalc_pos, ic->provided_data_sectors);
if (recalc_pos < ic->provided_data_sectors) {
queue_work(ic->recalc_wq, &ic->recalc_work);
} else if (recalc_pos > ic->provided_data_sectors) {
ic->sb->recalc_sector = cpu_to_le64(ic->provided_data_sectors);
recalc_write_super(ic);
}
}
ic->reboot_notifier.notifier_call = dm_integrity_reboot;
ic->reboot_notifier.next = NULL;
ic->reboot_notifier.priority = INT_MAX - 1; /* be notified after md and before hardware drivers */
WARN_ON(register_reboot_notifier(&ic->reboot_notifier));
#if 0
/* set to 1 to stress test synchronous mode */
dm_integrity_enter_synchronous_mode(ic);
#endif
}
static void dm_integrity_status(struct dm_target *ti, status_type_t type,
unsigned int status_flags, char *result, unsigned int maxlen)
{
struct dm_integrity_c *ic = ti->private;
unsigned int arg_count;
size_t sz = 0;
switch (type) {
case STATUSTYPE_INFO:
DMEMIT("%llu %llu",
(unsigned long long)atomic64_read(&ic->number_of_mismatches),
ic->provided_data_sectors);
if (ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING))
DMEMIT(" %llu", le64_to_cpu(ic->sb->recalc_sector));
else
DMEMIT(" -");
break;
case STATUSTYPE_TABLE: {
__u64 watermark_percentage = (__u64)(ic->journal_entries - ic->free_sectors_threshold) * 100;
watermark_percentage += ic->journal_entries / 2;
do_div(watermark_percentage, ic->journal_entries);
arg_count = 3;
arg_count += !!ic->meta_dev;
arg_count += ic->sectors_per_block != 1;
arg_count += !!(ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING));
arg_count += ic->reset_recalculate_flag;
arg_count += ic->discard;
arg_count += ic->mode == 'J';
arg_count += ic->mode == 'J';
arg_count += ic->mode == 'B';
arg_count += ic->mode == 'B';
arg_count += !!ic->internal_hash_alg.alg_string;
arg_count += !!ic->journal_crypt_alg.alg_string;
arg_count += !!ic->journal_mac_alg.alg_string;
arg_count += (ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_PADDING)) != 0;
arg_count += (ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_HMAC)) != 0;
arg_count += ic->legacy_recalculate;
DMEMIT("%s %llu %u %c %u", ic->dev->name, ic->start,
ic->tag_size, ic->mode, arg_count);
if (ic->meta_dev)
DMEMIT(" meta_device:%s", ic->meta_dev->name);
if (ic->sectors_per_block != 1)
DMEMIT(" block_size:%u", ic->sectors_per_block << SECTOR_SHIFT);
if (ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING))
DMEMIT(" recalculate");
if (ic->reset_recalculate_flag)
DMEMIT(" reset_recalculate");
if (ic->discard)
DMEMIT(" allow_discards");
DMEMIT(" journal_sectors:%u", ic->initial_sectors - SB_SECTORS);
DMEMIT(" interleave_sectors:%u", 1U << ic->sb->log2_interleave_sectors);
DMEMIT(" buffer_sectors:%u", 1U << ic->log2_buffer_sectors);
if (ic->mode == 'J') {
DMEMIT(" journal_watermark:%u", (unsigned int)watermark_percentage);
DMEMIT(" commit_time:%u", ic->autocommit_msec);
}
if (ic->mode == 'B') {
DMEMIT(" sectors_per_bit:%llu", (sector_t)ic->sectors_per_block << ic->log2_blocks_per_bitmap_bit);
DMEMIT(" bitmap_flush_interval:%u", jiffies_to_msecs(ic->bitmap_flush_interval));
}
if ((ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_PADDING)) != 0)
DMEMIT(" fix_padding");
if ((ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_HMAC)) != 0)
DMEMIT(" fix_hmac");
if (ic->legacy_recalculate)
DMEMIT(" legacy_recalculate");
#define EMIT_ALG(a, n) \
do { \
if (ic->a.alg_string) { \
DMEMIT(" %s:%s", n, ic->a.alg_string); \
if (ic->a.key_string) \
DMEMIT(":%s", ic->a.key_string);\
} \
} while (0)
EMIT_ALG(internal_hash_alg, "internal_hash");
EMIT_ALG(journal_crypt_alg, "journal_crypt");
EMIT_ALG(journal_mac_alg, "journal_mac");
break;
}
case STATUSTYPE_IMA:
DMEMIT_TARGET_NAME_VERSION(ti->type);
DMEMIT(",dev_name=%s,start=%llu,tag_size=%u,mode=%c",
ic->dev->name, ic->start, ic->tag_size, ic->mode);
if (ic->meta_dev)
DMEMIT(",meta_device=%s", ic->meta_dev->name);
if (ic->sectors_per_block != 1)
DMEMIT(",block_size=%u", ic->sectors_per_block << SECTOR_SHIFT);
DMEMIT(",recalculate=%c", (ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING)) ?
'y' : 'n');
DMEMIT(",allow_discards=%c", ic->discard ? 'y' : 'n');
DMEMIT(",fix_padding=%c",
((ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_PADDING)) != 0) ? 'y' : 'n');
DMEMIT(",fix_hmac=%c",
((ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_HMAC)) != 0) ? 'y' : 'n');
DMEMIT(",legacy_recalculate=%c", ic->legacy_recalculate ? 'y' : 'n');
DMEMIT(",journal_sectors=%u", ic->initial_sectors - SB_SECTORS);
DMEMIT(",interleave_sectors=%u", 1U << ic->sb->log2_interleave_sectors);
DMEMIT(",buffer_sectors=%u", 1U << ic->log2_buffer_sectors);
DMEMIT(";");
break;
}
}
static int dm_integrity_iterate_devices(struct dm_target *ti,
iterate_devices_callout_fn fn, void *data)
{
struct dm_integrity_c *ic = ti->private;
if (!ic->meta_dev)
return fn(ti, ic->dev, ic->start + ic->initial_sectors + ic->metadata_run, ti->len, data);
else
return fn(ti, ic->dev, 0, ti->len, data);
}
static void dm_integrity_io_hints(struct dm_target *ti, struct queue_limits *limits)
{
struct dm_integrity_c *ic = ti->private;
if (ic->sectors_per_block > 1) {
limits->logical_block_size = ic->sectors_per_block << SECTOR_SHIFT;
limits->physical_block_size = ic->sectors_per_block << SECTOR_SHIFT;
blk_limits_io_min(limits, ic->sectors_per_block << SECTOR_SHIFT);
limits->dma_alignment = limits->logical_block_size - 1;
}
}
static void calculate_journal_section_size(struct dm_integrity_c *ic)
{
unsigned int sector_space = JOURNAL_SECTOR_DATA;
ic->journal_sections = le32_to_cpu(ic->sb->journal_sections);
ic->journal_entry_size = roundup(offsetof(struct journal_entry, last_bytes[ic->sectors_per_block]) + ic->tag_size,
JOURNAL_ENTRY_ROUNDUP);
if (ic->sb->flags & cpu_to_le32(SB_FLAG_HAVE_JOURNAL_MAC))
sector_space -= JOURNAL_MAC_PER_SECTOR;
ic->journal_entries_per_sector = sector_space / ic->journal_entry_size;
ic->journal_section_entries = ic->journal_entries_per_sector * JOURNAL_BLOCK_SECTORS;
ic->journal_section_sectors = (ic->journal_section_entries << ic->sb->log2_sectors_per_block) + JOURNAL_BLOCK_SECTORS;
ic->journal_entries = ic->journal_section_entries * ic->journal_sections;
}
static int calculate_device_limits(struct dm_integrity_c *ic)
{
__u64 initial_sectors;
calculate_journal_section_size(ic);
initial_sectors = SB_SECTORS + (__u64)ic->journal_section_sectors * ic->journal_sections;
if (initial_sectors + METADATA_PADDING_SECTORS >= ic->meta_device_sectors || initial_sectors > UINT_MAX)
return -EINVAL;
ic->initial_sectors = initial_sectors;
if (!ic->meta_dev) {
sector_t last_sector, last_area, last_offset;
/* we have to maintain excessive padding for compatibility with existing volumes */
__u64 metadata_run_padding =
ic->sb->flags & cpu_to_le32(SB_FLAG_FIXED_PADDING) ?
(__u64)(METADATA_PADDING_SECTORS << SECTOR_SHIFT) :
(__u64)(1 << SECTOR_SHIFT << METADATA_PADDING_SECTORS);
ic->metadata_run = round_up((__u64)ic->tag_size << (ic->sb->log2_interleave_sectors - ic->sb->log2_sectors_per_block),
metadata_run_padding) >> SECTOR_SHIFT;
if (!(ic->metadata_run & (ic->metadata_run - 1)))
ic->log2_metadata_run = __ffs(ic->metadata_run);
else
ic->log2_metadata_run = -1;
get_area_and_offset(ic, ic->provided_data_sectors - 1, &last_area, &last_offset);
last_sector = get_data_sector(ic, last_area, last_offset);
if (last_sector < ic->start || last_sector >= ic->meta_device_sectors)
return -EINVAL;
} else {
__u64 meta_size = (ic->provided_data_sectors >> ic->sb->log2_sectors_per_block) * ic->tag_size;
meta_size = (meta_size + ((1U << (ic->log2_buffer_sectors + SECTOR_SHIFT)) - 1))
>> (ic->log2_buffer_sectors + SECTOR_SHIFT);
meta_size <<= ic->log2_buffer_sectors;
if (ic->initial_sectors + meta_size < ic->initial_sectors ||
ic->initial_sectors + meta_size > ic->meta_device_sectors)
return -EINVAL;
ic->metadata_run = 1;
ic->log2_metadata_run = 0;
}
return 0;
}
static void get_provided_data_sectors(struct dm_integrity_c *ic)
{
if (!ic->meta_dev) {
int test_bit;
ic->provided_data_sectors = 0;
for (test_bit = fls64(ic->meta_device_sectors) - 1; test_bit >= 3; test_bit--) {
__u64 prev_data_sectors = ic->provided_data_sectors;
ic->provided_data_sectors |= (sector_t)1 << test_bit;
if (calculate_device_limits(ic))
ic->provided_data_sectors = prev_data_sectors;
}
} else {
ic->provided_data_sectors = ic->data_device_sectors;
ic->provided_data_sectors &= ~(sector_t)(ic->sectors_per_block - 1);
}
}
static int initialize_superblock(struct dm_integrity_c *ic,
unsigned int journal_sectors, unsigned int interleave_sectors)
{
unsigned int journal_sections;
int test_bit;
memset(ic->sb, 0, SB_SECTORS << SECTOR_SHIFT);
memcpy(ic->sb->magic, SB_MAGIC, 8);
ic->sb->integrity_tag_size = cpu_to_le16(ic->tag_size);
ic->sb->log2_sectors_per_block = __ffs(ic->sectors_per_block);
if (ic->journal_mac_alg.alg_string)
ic->sb->flags |= cpu_to_le32(SB_FLAG_HAVE_JOURNAL_MAC);
calculate_journal_section_size(ic);
journal_sections = journal_sectors / ic->journal_section_sectors;
if (!journal_sections)
journal_sections = 1;
if (ic->fix_hmac && (ic->internal_hash_alg.alg_string || ic->journal_mac_alg.alg_string)) {
ic->sb->flags |= cpu_to_le32(SB_FLAG_FIXED_HMAC);
get_random_bytes(ic->sb->salt, SALT_SIZE);
}
if (!ic->meta_dev) {
if (ic->fix_padding)
ic->sb->flags |= cpu_to_le32(SB_FLAG_FIXED_PADDING);
ic->sb->journal_sections = cpu_to_le32(journal_sections);
if (!interleave_sectors)
interleave_sectors = DEFAULT_INTERLEAVE_SECTORS;
ic->sb->log2_interleave_sectors = __fls(interleave_sectors);
ic->sb->log2_interleave_sectors = max_t(__u8, MIN_LOG2_INTERLEAVE_SECTORS, ic->sb->log2_interleave_sectors);
ic->sb->log2_interleave_sectors = min_t(__u8, MAX_LOG2_INTERLEAVE_SECTORS, ic->sb->log2_interleave_sectors);
get_provided_data_sectors(ic);
if (!ic->provided_data_sectors)
return -EINVAL;
} else {
ic->sb->log2_interleave_sectors = 0;
get_provided_data_sectors(ic);
if (!ic->provided_data_sectors)
return -EINVAL;
try_smaller_buffer:
ic->sb->journal_sections = cpu_to_le32(0);
for (test_bit = fls(journal_sections) - 1; test_bit >= 0; test_bit--) {
__u32 prev_journal_sections = le32_to_cpu(ic->sb->journal_sections);
__u32 test_journal_sections = prev_journal_sections | (1U << test_bit);
if (test_journal_sections > journal_sections)
continue;
ic->sb->journal_sections = cpu_to_le32(test_journal_sections);
if (calculate_device_limits(ic))
ic->sb->journal_sections = cpu_to_le32(prev_journal_sections);
}
if (!le32_to_cpu(ic->sb->journal_sections)) {
if (ic->log2_buffer_sectors > 3) {
ic->log2_buffer_sectors--;
goto try_smaller_buffer;
}
return -EINVAL;
}
}
ic->sb->provided_data_sectors = cpu_to_le64(ic->provided_data_sectors);
sb_set_version(ic);
return 0;
}
static void dm_integrity_set(struct dm_target *ti, struct dm_integrity_c *ic)
{
struct gendisk *disk = dm_disk(dm_table_get_md(ti->table));
struct blk_integrity bi;
memset(&bi, 0, sizeof(bi));
bi.profile = &dm_integrity_profile;
bi.tuple_size = ic->tag_size;
bi.tag_size = bi.tuple_size;
bi.interval_exp = ic->sb->log2_sectors_per_block + SECTOR_SHIFT;
blk_integrity_register(disk, &bi);
blk_queue_max_integrity_segments(disk->queue, UINT_MAX);
}
static void dm_integrity_free_page_list(struct page_list *pl)
{
unsigned int i;
if (!pl)
return;
for (i = 0; pl[i].page; i++)
__free_page(pl[i].page);
kvfree(pl);
}
static struct page_list *dm_integrity_alloc_page_list(unsigned int n_pages)
{
struct page_list *pl;
unsigned int i;
pl = kvmalloc_array(n_pages + 1, sizeof(struct page_list), GFP_KERNEL | __GFP_ZERO);
if (!pl)
return NULL;
for (i = 0; i < n_pages; i++) {
pl[i].page = alloc_page(GFP_KERNEL);
if (!pl[i].page) {
dm_integrity_free_page_list(pl);
return NULL;
}
if (i)
pl[i - 1].next = &pl[i];
}
pl[i].page = NULL;
pl[i].next = NULL;
return pl;
}
static void dm_integrity_free_journal_scatterlist(struct dm_integrity_c *ic, struct scatterlist **sl)
{
unsigned int i;
for (i = 0; i < ic->journal_sections; i++)
kvfree(sl[i]);
kvfree(sl);
}
static struct scatterlist **dm_integrity_alloc_journal_scatterlist(struct dm_integrity_c *ic,
struct page_list *pl)
{
struct scatterlist **sl;
unsigned int i;
sl = kvmalloc_array(ic->journal_sections,
sizeof(struct scatterlist *),
GFP_KERNEL | __GFP_ZERO);
if (!sl)
return NULL;
for (i = 0; i < ic->journal_sections; i++) {
struct scatterlist *s;
unsigned int start_index, start_offset;
unsigned int end_index, end_offset;
unsigned int n_pages;
unsigned int idx;
page_list_location(ic, i, 0, &start_index, &start_offset);
page_list_location(ic, i, ic->journal_section_sectors - 1,
&end_index, &end_offset);
n_pages = (end_index - start_index + 1);
s = kvmalloc_array(n_pages, sizeof(struct scatterlist),
GFP_KERNEL);
if (!s) {
dm_integrity_free_journal_scatterlist(ic, sl);
return NULL;
}
sg_init_table(s, n_pages);
for (idx = start_index; idx <= end_index; idx++) {
char *va = lowmem_page_address(pl[idx].page);
unsigned int start = 0, end = PAGE_SIZE;
if (idx == start_index)
start = start_offset;
if (idx == end_index)
end = end_offset + (1 << SECTOR_SHIFT);
sg_set_buf(&s[idx - start_index], va + start, end - start);
}
sl[i] = s;
}
return sl;
}
static void free_alg(struct alg_spec *a)
{
kfree_sensitive(a->alg_string);
kfree_sensitive(a->key);
memset(a, 0, sizeof(*a));
}
static int get_alg_and_key(const char *arg, struct alg_spec *a, char **error, char *error_inval)
{
char *k;
free_alg(a);
a->alg_string = kstrdup(strchr(arg, ':') + 1, GFP_KERNEL);
if (!a->alg_string)
goto nomem;
k = strchr(a->alg_string, ':');
if (k) {
*k = 0;
a->key_string = k + 1;
if (strlen(a->key_string) & 1)
goto inval;
a->key_size = strlen(a->key_string) / 2;
a->key = kmalloc(a->key_size, GFP_KERNEL);
if (!a->key)
goto nomem;
if (hex2bin(a->key, a->key_string, a->key_size))
goto inval;
}
return 0;
inval:
*error = error_inval;
return -EINVAL;
nomem:
*error = "Out of memory for an argument";
return -ENOMEM;
}
static int get_mac(struct crypto_shash **hash, struct alg_spec *a, char **error,
char *error_alg, char *error_key)
{
int r;
if (a->alg_string) {
*hash = crypto_alloc_shash(a->alg_string, 0, CRYPTO_ALG_ALLOCATES_MEMORY);
if (IS_ERR(*hash)) {
*error = error_alg;
r = PTR_ERR(*hash);
*hash = NULL;
return r;
}
if (a->key) {
r = crypto_shash_setkey(*hash, a->key, a->key_size);
if (r) {
*error = error_key;
return r;
}
} else if (crypto_shash_get_flags(*hash) & CRYPTO_TFM_NEED_KEY) {
*error = error_key;
return -ENOKEY;
}
}
return 0;
}
static int create_journal(struct dm_integrity_c *ic, char **error)
{
int r = 0;
unsigned int i;
__u64 journal_pages, journal_desc_size, journal_tree_size;
unsigned char *crypt_data = NULL, *crypt_iv = NULL;
struct skcipher_request *req = NULL;
ic->commit_ids[0] = cpu_to_le64(0x1111111111111111ULL);
ic->commit_ids[1] = cpu_to_le64(0x2222222222222222ULL);
ic->commit_ids[2] = cpu_to_le64(0x3333333333333333ULL);
ic->commit_ids[3] = cpu_to_le64(0x4444444444444444ULL);
journal_pages = roundup((__u64)ic->journal_sections * ic->journal_section_sectors,
PAGE_SIZE >> SECTOR_SHIFT) >> (PAGE_SHIFT - SECTOR_SHIFT);
journal_desc_size = journal_pages * sizeof(struct page_list);
if (journal_pages >= totalram_pages() - totalhigh_pages() || journal_desc_size > ULONG_MAX) {
*error = "Journal doesn't fit into memory";
r = -ENOMEM;
goto bad;
}
ic->journal_pages = journal_pages;
ic->journal = dm_integrity_alloc_page_list(ic->journal_pages);
if (!ic->journal) {
*error = "Could not allocate memory for journal";
r = -ENOMEM;
goto bad;
}
if (ic->journal_crypt_alg.alg_string) {
unsigned int ivsize, blocksize;
struct journal_completion comp;
comp.ic = ic;
ic->journal_crypt = crypto_alloc_skcipher(ic->journal_crypt_alg.alg_string, 0, CRYPTO_ALG_ALLOCATES_MEMORY);
if (IS_ERR(ic->journal_crypt)) {
*error = "Invalid journal cipher";
r = PTR_ERR(ic->journal_crypt);
ic->journal_crypt = NULL;
goto bad;
}
ivsize = crypto_skcipher_ivsize(ic->journal_crypt);
blocksize = crypto_skcipher_blocksize(ic->journal_crypt);
if (ic->journal_crypt_alg.key) {
r = crypto_skcipher_setkey(ic->journal_crypt, ic->journal_crypt_alg.key,
ic->journal_crypt_alg.key_size);
if (r) {
*error = "Error setting encryption key";
goto bad;
}
}
DEBUG_print("cipher %s, block size %u iv size %u\n",
ic->journal_crypt_alg.alg_string, blocksize, ivsize);
ic->journal_io = dm_integrity_alloc_page_list(ic->journal_pages);
if (!ic->journal_io) {
*error = "Could not allocate memory for journal io";
r = -ENOMEM;
goto bad;
}
if (blocksize == 1) {
struct scatterlist *sg;
req = skcipher_request_alloc(ic->journal_crypt, GFP_KERNEL);
if (!req) {
*error = "Could not allocate crypt request";
r = -ENOMEM;
goto bad;
}
crypt_iv = kzalloc(ivsize, GFP_KERNEL);
if (!crypt_iv) {
*error = "Could not allocate iv";
r = -ENOMEM;
goto bad;
}
ic->journal_xor = dm_integrity_alloc_page_list(ic->journal_pages);
if (!ic->journal_xor) {
*error = "Could not allocate memory for journal xor";
r = -ENOMEM;
goto bad;
}
sg = kvmalloc_array(ic->journal_pages + 1,
sizeof(struct scatterlist),
GFP_KERNEL);
if (!sg) {
*error = "Unable to allocate sg list";
r = -ENOMEM;
goto bad;
}
sg_init_table(sg, ic->journal_pages + 1);
for (i = 0; i < ic->journal_pages; i++) {
char *va = lowmem_page_address(ic->journal_xor[i].page);
clear_page(va);
sg_set_buf(&sg[i], va, PAGE_SIZE);
}
sg_set_buf(&sg[i], &ic->commit_ids, sizeof(ic->commit_ids));
skcipher_request_set_crypt(req, sg, sg,
PAGE_SIZE * ic->journal_pages + sizeof(ic->commit_ids), crypt_iv);
init_completion(&comp.comp);
comp.in_flight = (atomic_t)ATOMIC_INIT(1);
if (do_crypt(true, req, &comp))
wait_for_completion(&comp.comp);
kvfree(sg);
r = dm_integrity_failed(ic);
if (r) {
*error = "Unable to encrypt journal";
goto bad;
}
DEBUG_bytes(lowmem_page_address(ic->journal_xor[0].page), 64, "xor data");
crypto_free_skcipher(ic->journal_crypt);
ic->journal_crypt = NULL;
} else {
unsigned int crypt_len = roundup(ivsize, blocksize);
req = skcipher_request_alloc(ic->journal_crypt, GFP_KERNEL);
if (!req) {
*error = "Could not allocate crypt request";
r = -ENOMEM;
goto bad;
}
crypt_iv = kmalloc(ivsize, GFP_KERNEL);
if (!crypt_iv) {
*error = "Could not allocate iv";
r = -ENOMEM;
goto bad;
}
crypt_data = kmalloc(crypt_len, GFP_KERNEL);
if (!crypt_data) {
*error = "Unable to allocate crypt data";
r = -ENOMEM;
goto bad;
}
ic->journal_scatterlist = dm_integrity_alloc_journal_scatterlist(ic, ic->journal);
if (!ic->journal_scatterlist) {
*error = "Unable to allocate sg list";
r = -ENOMEM;
goto bad;
}
ic->journal_io_scatterlist = dm_integrity_alloc_journal_scatterlist(ic, ic->journal_io);
if (!ic->journal_io_scatterlist) {
*error = "Unable to allocate sg list";
r = -ENOMEM;
goto bad;
}
ic->sk_requests = kvmalloc_array(ic->journal_sections,
sizeof(struct skcipher_request *),
GFP_KERNEL | __GFP_ZERO);
if (!ic->sk_requests) {
*error = "Unable to allocate sk requests";
r = -ENOMEM;
goto bad;
}
for (i = 0; i < ic->journal_sections; i++) {
struct scatterlist sg;
struct skcipher_request *section_req;
__le32 section_le = cpu_to_le32(i);
memset(crypt_iv, 0x00, ivsize);
memset(crypt_data, 0x00, crypt_len);
memcpy(crypt_data, §ion_le, min_t(size_t, crypt_len, sizeof(section_le)));
sg_init_one(&sg, crypt_data, crypt_len);
skcipher_request_set_crypt(req, &sg, &sg, crypt_len, crypt_iv);
init_completion(&comp.comp);
comp.in_flight = (atomic_t)ATOMIC_INIT(1);
if (do_crypt(true, req, &comp))
wait_for_completion(&comp.comp);
r = dm_integrity_failed(ic);
if (r) {
*error = "Unable to generate iv";
goto bad;
}
section_req = skcipher_request_alloc(ic->journal_crypt, GFP_KERNEL);
if (!section_req) {
*error = "Unable to allocate crypt request";
r = -ENOMEM;
goto bad;
}
section_req->iv = kmalloc_array(ivsize, 2,
GFP_KERNEL);
if (!section_req->iv) {
skcipher_request_free(section_req);
*error = "Unable to allocate iv";
r = -ENOMEM;
goto bad;
}
memcpy(section_req->iv + ivsize, crypt_data, ivsize);
section_req->cryptlen = (size_t)ic->journal_section_sectors << SECTOR_SHIFT;
ic->sk_requests[i] = section_req;
DEBUG_bytes(crypt_data, ivsize, "iv(%u)", i);
}
}
}
for (i = 0; i < N_COMMIT_IDS; i++) {
unsigned int j;
retest_commit_id:
for (j = 0; j < i; j++) {
if (ic->commit_ids[j] == ic->commit_ids[i]) {
ic->commit_ids[i] = cpu_to_le64(le64_to_cpu(ic->commit_ids[i]) + 1);
goto retest_commit_id;
}
}
DEBUG_print("commit id %u: %016llx\n", i, ic->commit_ids[i]);
}
journal_tree_size = (__u64)ic->journal_entries * sizeof(struct journal_node);
if (journal_tree_size > ULONG_MAX) {
*error = "Journal doesn't fit into memory";
r = -ENOMEM;
goto bad;
}
ic->journal_tree = kvmalloc(journal_tree_size, GFP_KERNEL);
if (!ic->journal_tree) {
*error = "Could not allocate memory for journal tree";
r = -ENOMEM;
}
bad:
kfree(crypt_data);
kfree(crypt_iv);
skcipher_request_free(req);
return r;
}
/*
* Construct a integrity mapping
*
* Arguments:
* device
* offset from the start of the device
* tag size
* D - direct writes, J - journal writes, B - bitmap mode, R - recovery mode
* number of optional arguments
* optional arguments:
* journal_sectors
* interleave_sectors
* buffer_sectors
* journal_watermark
* commit_time
* meta_device
* block_size
* sectors_per_bit
* bitmap_flush_interval
* internal_hash
* journal_crypt
* journal_mac
* recalculate
*/
static int dm_integrity_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
struct dm_integrity_c *ic;
char dummy;
int r;
unsigned int extra_args;
struct dm_arg_set as;
static const struct dm_arg _args[] = {
{0, 18, "Invalid number of feature args"},
};
unsigned int journal_sectors, interleave_sectors, buffer_sectors, journal_watermark, sync_msec;
bool should_write_sb;
__u64 threshold;
unsigned long long start;
__s8 log2_sectors_per_bitmap_bit = -1;
__s8 log2_blocks_per_bitmap_bit;
__u64 bits_in_journal;
__u64 n_bitmap_bits;
#define DIRECT_ARGUMENTS 4
if (argc <= DIRECT_ARGUMENTS) {
ti->error = "Invalid argument count";
return -EINVAL;
}
ic = kzalloc(sizeof(struct dm_integrity_c), GFP_KERNEL);
if (!ic) {
ti->error = "Cannot allocate integrity context";
return -ENOMEM;
}
ti->private = ic;
ti->per_io_data_size = sizeof(struct dm_integrity_io);
ic->ti = ti;
ic->in_progress = RB_ROOT;
INIT_LIST_HEAD(&ic->wait_list);
init_waitqueue_head(&ic->endio_wait);
bio_list_init(&ic->flush_bio_list);
init_waitqueue_head(&ic->copy_to_journal_wait);
init_completion(&ic->crypto_backoff);
atomic64_set(&ic->number_of_mismatches, 0);
ic->bitmap_flush_interval = BITMAP_FLUSH_INTERVAL;
r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &ic->dev);
if (r) {
ti->error = "Device lookup failed";
goto bad;
}
if (sscanf(argv[1], "%llu%c", &start, &dummy) != 1 || start != (sector_t)start) {
ti->error = "Invalid starting offset";
r = -EINVAL;
goto bad;
}
ic->start = start;
if (strcmp(argv[2], "-")) {
if (sscanf(argv[2], "%u%c", &ic->tag_size, &dummy) != 1 || !ic->tag_size) {
ti->error = "Invalid tag size";
r = -EINVAL;
goto bad;
}
}
if (!strcmp(argv[3], "J") || !strcmp(argv[3], "B") ||
!strcmp(argv[3], "D") || !strcmp(argv[3], "R")) {
ic->mode = argv[3][0];
} else {
ti->error = "Invalid mode (expecting J, B, D, R)";
r = -EINVAL;
goto bad;
}
journal_sectors = 0;
interleave_sectors = DEFAULT_INTERLEAVE_SECTORS;
buffer_sectors = DEFAULT_BUFFER_SECTORS;
journal_watermark = DEFAULT_JOURNAL_WATERMARK;
sync_msec = DEFAULT_SYNC_MSEC;
ic->sectors_per_block = 1;
as.argc = argc - DIRECT_ARGUMENTS;
as.argv = argv + DIRECT_ARGUMENTS;
r = dm_read_arg_group(_args, &as, &extra_args, &ti->error);
if (r)
goto bad;
while (extra_args--) {
const char *opt_string;
unsigned int val;
unsigned long long llval;
opt_string = dm_shift_arg(&as);
if (!opt_string) {
r = -EINVAL;
ti->error = "Not enough feature arguments";
goto bad;
}
if (sscanf(opt_string, "journal_sectors:%u%c", &val, &dummy) == 1)
journal_sectors = val ? val : 1;
else if (sscanf(opt_string, "interleave_sectors:%u%c", &val, &dummy) == 1)
interleave_sectors = val;
else if (sscanf(opt_string, "buffer_sectors:%u%c", &val, &dummy) == 1)
buffer_sectors = val;
else if (sscanf(opt_string, "journal_watermark:%u%c", &val, &dummy) == 1 && val <= 100)
journal_watermark = val;
else if (sscanf(opt_string, "commit_time:%u%c", &val, &dummy) == 1)
sync_msec = val;
else if (!strncmp(opt_string, "meta_device:", strlen("meta_device:"))) {
if (ic->meta_dev) {
dm_put_device(ti, ic->meta_dev);
ic->meta_dev = NULL;
}
r = dm_get_device(ti, strchr(opt_string, ':') + 1,
dm_table_get_mode(ti->table), &ic->meta_dev);
if (r) {
ti->error = "Device lookup failed";
goto bad;
}
} else if (sscanf(opt_string, "block_size:%u%c", &val, &dummy) == 1) {
if (val < 1 << SECTOR_SHIFT ||
val > MAX_SECTORS_PER_BLOCK << SECTOR_SHIFT ||
(val & (val - 1))) {
r = -EINVAL;
ti->error = "Invalid block_size argument";
goto bad;
}
ic->sectors_per_block = val >> SECTOR_SHIFT;
} else if (sscanf(opt_string, "sectors_per_bit:%llu%c", &llval, &dummy) == 1) {
log2_sectors_per_bitmap_bit = !llval ? 0 : __ilog2_u64(llval);
} else if (sscanf(opt_string, "bitmap_flush_interval:%u%c", &val, &dummy) == 1) {
if (val >= (uint64_t)UINT_MAX * 1000 / HZ) {
r = -EINVAL;
ti->error = "Invalid bitmap_flush_interval argument";
goto bad;
}
ic->bitmap_flush_interval = msecs_to_jiffies(val);
} else if (!strncmp(opt_string, "internal_hash:", strlen("internal_hash:"))) {
r = get_alg_and_key(opt_string, &ic->internal_hash_alg, &ti->error,
"Invalid internal_hash argument");
if (r)
goto bad;
} else if (!strncmp(opt_string, "journal_crypt:", strlen("journal_crypt:"))) {
r = get_alg_and_key(opt_string, &ic->journal_crypt_alg, &ti->error,
"Invalid journal_crypt argument");
if (r)
goto bad;
} else if (!strncmp(opt_string, "journal_mac:", strlen("journal_mac:"))) {
r = get_alg_and_key(opt_string, &ic->journal_mac_alg, &ti->error,
"Invalid journal_mac argument");
if (r)
goto bad;
} else if (!strcmp(opt_string, "recalculate")) {
ic->recalculate_flag = true;
} else if (!strcmp(opt_string, "reset_recalculate")) {
ic->recalculate_flag = true;
ic->reset_recalculate_flag = true;
} else if (!strcmp(opt_string, "allow_discards")) {
ic->discard = true;
} else if (!strcmp(opt_string, "fix_padding")) {
ic->fix_padding = true;
} else if (!strcmp(opt_string, "fix_hmac")) {
ic->fix_hmac = true;
} else if (!strcmp(opt_string, "legacy_recalculate")) {
ic->legacy_recalculate = true;
} else {
r = -EINVAL;
ti->error = "Invalid argument";
goto bad;
}
}
ic->data_device_sectors = bdev_nr_sectors(ic->dev->bdev);
if (!ic->meta_dev)
ic->meta_device_sectors = ic->data_device_sectors;
else
ic->meta_device_sectors = bdev_nr_sectors(ic->meta_dev->bdev);
if (!journal_sectors) {
journal_sectors = min((sector_t)DEFAULT_MAX_JOURNAL_SECTORS,
ic->data_device_sectors >> DEFAULT_JOURNAL_SIZE_FACTOR);
}
if (!buffer_sectors)
buffer_sectors = 1;
ic->log2_buffer_sectors = min((int)__fls(buffer_sectors), 31 - SECTOR_SHIFT);
r = get_mac(&ic->internal_hash, &ic->internal_hash_alg, &ti->error,
"Invalid internal hash", "Error setting internal hash key");
if (r)
goto bad;
r = get_mac(&ic->journal_mac, &ic->journal_mac_alg, &ti->error,
"Invalid journal mac", "Error setting journal mac key");
if (r)
goto bad;
if (!ic->tag_size) {
if (!ic->internal_hash) {
ti->error = "Unknown tag size";
r = -EINVAL;
goto bad;
}
ic->tag_size = crypto_shash_digestsize(ic->internal_hash);
}
if (ic->tag_size > MAX_TAG_SIZE) {
ti->error = "Too big tag size";
r = -EINVAL;
goto bad;
}
if (!(ic->tag_size & (ic->tag_size - 1)))
ic->log2_tag_size = __ffs(ic->tag_size);
else
ic->log2_tag_size = -1;
if (ic->mode == 'B' && !ic->internal_hash) {
r = -EINVAL;
ti->error = "Bitmap mode can be only used with internal hash";
goto bad;
}
if (ic->discard && !ic->internal_hash) {
r = -EINVAL;
ti->error = "Discard can be only used with internal hash";
goto bad;
}
ic->autocommit_jiffies = msecs_to_jiffies(sync_msec);
ic->autocommit_msec = sync_msec;
timer_setup(&ic->autocommit_timer, autocommit_fn, 0);
ic->io = dm_io_client_create();
if (IS_ERR(ic->io)) {
r = PTR_ERR(ic->io);
ic->io = NULL;
ti->error = "Cannot allocate dm io";
goto bad;
}
r = mempool_init_slab_pool(&ic->journal_io_mempool, JOURNAL_IO_MEMPOOL, journal_io_cache);
if (r) {
ti->error = "Cannot allocate mempool";
goto bad;
}
ic->metadata_wq = alloc_workqueue("dm-integrity-metadata",
WQ_MEM_RECLAIM, METADATA_WORKQUEUE_MAX_ACTIVE);
if (!ic->metadata_wq) {
ti->error = "Cannot allocate workqueue";
r = -ENOMEM;
goto bad;
}
/*
* If this workqueue weren't ordered, it would cause bio reordering
* and reduced performance.
*/
ic->wait_wq = alloc_ordered_workqueue("dm-integrity-wait", WQ_MEM_RECLAIM);
if (!ic->wait_wq) {
ti->error = "Cannot allocate workqueue";
r = -ENOMEM;
goto bad;
}
ic->offload_wq = alloc_workqueue("dm-integrity-offload", WQ_MEM_RECLAIM,
METADATA_WORKQUEUE_MAX_ACTIVE);
if (!ic->offload_wq) {
ti->error = "Cannot allocate workqueue";
r = -ENOMEM;
goto bad;
}
ic->commit_wq = alloc_workqueue("dm-integrity-commit", WQ_MEM_RECLAIM, 1);
if (!ic->commit_wq) {
ti->error = "Cannot allocate workqueue";
r = -ENOMEM;
goto bad;
}
INIT_WORK(&ic->commit_work, integrity_commit);
if (ic->mode == 'J' || ic->mode == 'B') {
ic->writer_wq = alloc_workqueue("dm-integrity-writer", WQ_MEM_RECLAIM, 1);
if (!ic->writer_wq) {
ti->error = "Cannot allocate workqueue";
r = -ENOMEM;
goto bad;
}
INIT_WORK(&ic->writer_work, integrity_writer);
}
ic->sb = alloc_pages_exact(SB_SECTORS << SECTOR_SHIFT, GFP_KERNEL);
if (!ic->sb) {
r = -ENOMEM;
ti->error = "Cannot allocate superblock area";
goto bad;
}
r = sync_rw_sb(ic, REQ_OP_READ);
if (r) {
ti->error = "Error reading superblock";
goto bad;
}
should_write_sb = false;
if (memcmp(ic->sb->magic, SB_MAGIC, 8)) {
if (ic->mode != 'R') {
if (memchr_inv(ic->sb, 0, SB_SECTORS << SECTOR_SHIFT)) {
r = -EINVAL;
ti->error = "The device is not initialized";
goto bad;
}
}
r = initialize_superblock(ic, journal_sectors, interleave_sectors);
if (r) {
ti->error = "Could not initialize superblock";
goto bad;
}
if (ic->mode != 'R')
should_write_sb = true;
}
if (!ic->sb->version || ic->sb->version > SB_VERSION_5) {
r = -EINVAL;
ti->error = "Unknown version";
goto bad;
}
if (le16_to_cpu(ic->sb->integrity_tag_size) != ic->tag_size) {
r = -EINVAL;
ti->error = "Tag size doesn't match the information in superblock";
goto bad;
}
if (ic->sb->log2_sectors_per_block != __ffs(ic->sectors_per_block)) {
r = -EINVAL;
ti->error = "Block size doesn't match the information in superblock";
goto bad;
}
if (!le32_to_cpu(ic->sb->journal_sections)) {
r = -EINVAL;
ti->error = "Corrupted superblock, journal_sections is 0";
goto bad;
}
/* make sure that ti->max_io_len doesn't overflow */
if (!ic->meta_dev) {
if (ic->sb->log2_interleave_sectors < MIN_LOG2_INTERLEAVE_SECTORS ||
ic->sb->log2_interleave_sectors > MAX_LOG2_INTERLEAVE_SECTORS) {
r = -EINVAL;
ti->error = "Invalid interleave_sectors in the superblock";
goto bad;
}
} else {
if (ic->sb->log2_interleave_sectors) {
r = -EINVAL;
ti->error = "Invalid interleave_sectors in the superblock";
goto bad;
}
}
if (!!(ic->sb->flags & cpu_to_le32(SB_FLAG_HAVE_JOURNAL_MAC)) != !!ic->journal_mac_alg.alg_string) {
r = -EINVAL;
ti->error = "Journal mac mismatch";
goto bad;
}
get_provided_data_sectors(ic);
if (!ic->provided_data_sectors) {
r = -EINVAL;
ti->error = "The device is too small";
goto bad;
}
try_smaller_buffer:
r = calculate_device_limits(ic);
if (r) {
if (ic->meta_dev) {
if (ic->log2_buffer_sectors > 3) {
ic->log2_buffer_sectors--;
goto try_smaller_buffer;
}
}
ti->error = "The device is too small";
goto bad;
}
if (log2_sectors_per_bitmap_bit < 0)
log2_sectors_per_bitmap_bit = __fls(DEFAULT_SECTORS_PER_BITMAP_BIT);
if (log2_sectors_per_bitmap_bit < ic->sb->log2_sectors_per_block)
log2_sectors_per_bitmap_bit = ic->sb->log2_sectors_per_block;
bits_in_journal = ((__u64)ic->journal_section_sectors * ic->journal_sections) << (SECTOR_SHIFT + 3);
if (bits_in_journal > UINT_MAX)
bits_in_journal = UINT_MAX;
while (bits_in_journal < (ic->provided_data_sectors + ((sector_t)1 << log2_sectors_per_bitmap_bit) - 1) >> log2_sectors_per_bitmap_bit)
log2_sectors_per_bitmap_bit++;
log2_blocks_per_bitmap_bit = log2_sectors_per_bitmap_bit - ic->sb->log2_sectors_per_block;
ic->log2_blocks_per_bitmap_bit = log2_blocks_per_bitmap_bit;
if (should_write_sb)
ic->sb->log2_blocks_per_bitmap_bit = log2_blocks_per_bitmap_bit;
n_bitmap_bits = ((ic->provided_data_sectors >> ic->sb->log2_sectors_per_block)
+ (((sector_t)1 << log2_blocks_per_bitmap_bit) - 1)) >> log2_blocks_per_bitmap_bit;
ic->n_bitmap_blocks = DIV_ROUND_UP(n_bitmap_bits, BITMAP_BLOCK_SIZE * 8);
if (!ic->meta_dev)
ic->log2_buffer_sectors = min(ic->log2_buffer_sectors, (__u8)__ffs(ic->metadata_run));
if (ti->len > ic->provided_data_sectors) {
r = -EINVAL;
ti->error = "Not enough provided sectors for requested mapping size";
goto bad;
}
threshold = (__u64)ic->journal_entries * (100 - journal_watermark);
threshold += 50;
do_div(threshold, 100);
ic->free_sectors_threshold = threshold;
DEBUG_print("initialized:\n");
DEBUG_print(" integrity_tag_size %u\n", le16_to_cpu(ic->sb->integrity_tag_size));
DEBUG_print(" journal_entry_size %u\n", ic->journal_entry_size);
DEBUG_print(" journal_entries_per_sector %u\n", ic->journal_entries_per_sector);
DEBUG_print(" journal_section_entries %u\n", ic->journal_section_entries);
DEBUG_print(" journal_section_sectors %u\n", ic->journal_section_sectors);
DEBUG_print(" journal_sections %u\n", (unsigned int)le32_to_cpu(ic->sb->journal_sections));
DEBUG_print(" journal_entries %u\n", ic->journal_entries);
DEBUG_print(" log2_interleave_sectors %d\n", ic->sb->log2_interleave_sectors);
DEBUG_print(" data_device_sectors 0x%llx\n", bdev_nr_sectors(ic->dev->bdev));
DEBUG_print(" initial_sectors 0x%x\n", ic->initial_sectors);
DEBUG_print(" metadata_run 0x%x\n", ic->metadata_run);
DEBUG_print(" log2_metadata_run %d\n", ic->log2_metadata_run);
DEBUG_print(" provided_data_sectors 0x%llx (%llu)\n", ic->provided_data_sectors, ic->provided_data_sectors);
DEBUG_print(" log2_buffer_sectors %u\n", ic->log2_buffer_sectors);
DEBUG_print(" bits_in_journal %llu\n", bits_in_journal);
if (ic->recalculate_flag && !(ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING))) {
ic->sb->flags |= cpu_to_le32(SB_FLAG_RECALCULATING);
ic->sb->recalc_sector = cpu_to_le64(0);
}
if (ic->internal_hash) {
ic->recalc_wq = alloc_workqueue("dm-integrity-recalc", WQ_MEM_RECLAIM, 1);
if (!ic->recalc_wq) {
ti->error = "Cannot allocate workqueue";
r = -ENOMEM;
goto bad;
}
INIT_WORK(&ic->recalc_work, integrity_recalc);
} else {
if (ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING)) {
ti->error = "Recalculate can only be specified with internal_hash";
r = -EINVAL;
goto bad;
}
}
if (ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING) &&
le64_to_cpu(ic->sb->recalc_sector) < ic->provided_data_sectors &&
dm_integrity_disable_recalculate(ic)) {
ti->error = "Recalculating with HMAC is disabled for security reasons - if you really need it, use the argument \"legacy_recalculate\"";
r = -EOPNOTSUPP;
goto bad;
}
ic->bufio = dm_bufio_client_create(ic->meta_dev ? ic->meta_dev->bdev : ic->dev->bdev,
1U << (SECTOR_SHIFT + ic->log2_buffer_sectors), 1, 0, NULL, NULL, 0);
if (IS_ERR(ic->bufio)) {
r = PTR_ERR(ic->bufio);
ti->error = "Cannot initialize dm-bufio";
ic->bufio = NULL;
goto bad;
}
dm_bufio_set_sector_offset(ic->bufio, ic->start + ic->initial_sectors);
if (ic->mode != 'R') {
r = create_journal(ic, &ti->error);
if (r)
goto bad;
}
if (ic->mode == 'B') {
unsigned int i;
unsigned int n_bitmap_pages = DIV_ROUND_UP(ic->n_bitmap_blocks, PAGE_SIZE / BITMAP_BLOCK_SIZE);
ic->recalc_bitmap = dm_integrity_alloc_page_list(n_bitmap_pages);
if (!ic->recalc_bitmap) {
r = -ENOMEM;
goto bad;
}
ic->may_write_bitmap = dm_integrity_alloc_page_list(n_bitmap_pages);
if (!ic->may_write_bitmap) {
r = -ENOMEM;
goto bad;
}
ic->bbs = kvmalloc_array(ic->n_bitmap_blocks, sizeof(struct bitmap_block_status), GFP_KERNEL);
if (!ic->bbs) {
r = -ENOMEM;
goto bad;
}
INIT_DELAYED_WORK(&ic->bitmap_flush_work, bitmap_flush_work);
for (i = 0; i < ic->n_bitmap_blocks; i++) {
struct bitmap_block_status *bbs = &ic->bbs[i];
unsigned int sector, pl_index, pl_offset;
INIT_WORK(&bbs->work, bitmap_block_work);
bbs->ic = ic;
bbs->idx = i;
bio_list_init(&bbs->bio_queue);
spin_lock_init(&bbs->bio_queue_lock);
sector = i * (BITMAP_BLOCK_SIZE >> SECTOR_SHIFT);
pl_index = sector >> (PAGE_SHIFT - SECTOR_SHIFT);
pl_offset = (sector << SECTOR_SHIFT) & (PAGE_SIZE - 1);
bbs->bitmap = lowmem_page_address(ic->journal[pl_index].page) + pl_offset;
}
}
if (should_write_sb) {
init_journal(ic, 0, ic->journal_sections, 0);
r = dm_integrity_failed(ic);
if (unlikely(r)) {
ti->error = "Error initializing journal";
goto bad;
}
r = sync_rw_sb(ic, REQ_OP_WRITE | REQ_FUA);
if (r) {
ti->error = "Error initializing superblock";
goto bad;
}
ic->just_formatted = true;
}
if (!ic->meta_dev) {
r = dm_set_target_max_io_len(ti, 1U << ic->sb->log2_interleave_sectors);
if (r)
goto bad;
}
if (ic->mode == 'B') {
unsigned int max_io_len;
max_io_len = ((sector_t)ic->sectors_per_block << ic->log2_blocks_per_bitmap_bit) * (BITMAP_BLOCK_SIZE * 8);
if (!max_io_len)
max_io_len = 1U << 31;
DEBUG_print("max_io_len: old %u, new %u\n", ti->max_io_len, max_io_len);
if (!ti->max_io_len || ti->max_io_len > max_io_len) {
r = dm_set_target_max_io_len(ti, max_io_len);
if (r)
goto bad;
}
}
if (!ic->internal_hash)
dm_integrity_set(ti, ic);
ti->num_flush_bios = 1;
ti->flush_supported = true;
if (ic->discard)
ti->num_discard_bios = 1;
dm_audit_log_ctr(DM_MSG_PREFIX, ti, 1);
return 0;
bad:
dm_audit_log_ctr(DM_MSG_PREFIX, ti, 0);
dm_integrity_dtr(ti);
return r;
}
static void dm_integrity_dtr(struct dm_target *ti)
{
struct dm_integrity_c *ic = ti->private;
BUG_ON(!RB_EMPTY_ROOT(&ic->in_progress));
BUG_ON(!list_empty(&ic->wait_list));
if (ic->mode == 'B')
cancel_delayed_work_sync(&ic->bitmap_flush_work);
if (ic->metadata_wq)
destroy_workqueue(ic->metadata_wq);
if (ic->wait_wq)
destroy_workqueue(ic->wait_wq);
if (ic->offload_wq)
destroy_workqueue(ic->offload_wq);
if (ic->commit_wq)
destroy_workqueue(ic->commit_wq);
if (ic->writer_wq)
destroy_workqueue(ic->writer_wq);
if (ic->recalc_wq)
destroy_workqueue(ic->recalc_wq);
kvfree(ic->bbs);
if (ic->bufio)
dm_bufio_client_destroy(ic->bufio);
mempool_exit(&ic->journal_io_mempool);
if (ic->io)
dm_io_client_destroy(ic->io);
if (ic->dev)
dm_put_device(ti, ic->dev);
if (ic->meta_dev)
dm_put_device(ti, ic->meta_dev);
dm_integrity_free_page_list(ic->journal);
dm_integrity_free_page_list(ic->journal_io);
dm_integrity_free_page_list(ic->journal_xor);
dm_integrity_free_page_list(ic->recalc_bitmap);
dm_integrity_free_page_list(ic->may_write_bitmap);
if (ic->journal_scatterlist)
dm_integrity_free_journal_scatterlist(ic, ic->journal_scatterlist);
if (ic->journal_io_scatterlist)
dm_integrity_free_journal_scatterlist(ic, ic->journal_io_scatterlist);
if (ic->sk_requests) {
unsigned int i;
for (i = 0; i < ic->journal_sections; i++) {
struct skcipher_request *req;
req = ic->sk_requests[i];
if (req) {
kfree_sensitive(req->iv);
skcipher_request_free(req);
}
}
kvfree(ic->sk_requests);
}
kvfree(ic->journal_tree);
if (ic->sb)
free_pages_exact(ic->sb, SB_SECTORS << SECTOR_SHIFT);
if (ic->internal_hash)
crypto_free_shash(ic->internal_hash);
free_alg(&ic->internal_hash_alg);
if (ic->journal_crypt)
crypto_free_skcipher(ic->journal_crypt);
free_alg(&ic->journal_crypt_alg);
if (ic->journal_mac)
crypto_free_shash(ic->journal_mac);
free_alg(&ic->journal_mac_alg);
kfree(ic);
dm_audit_log_dtr(DM_MSG_PREFIX, ti, 1);
}
static struct target_type integrity_target = {
.name = "integrity",
.version = {1, 10, 0},
.module = THIS_MODULE,
.features = DM_TARGET_SINGLETON | DM_TARGET_INTEGRITY,
.ctr = dm_integrity_ctr,
.dtr = dm_integrity_dtr,
.map = dm_integrity_map,
.postsuspend = dm_integrity_postsuspend,
.resume = dm_integrity_resume,
.status = dm_integrity_status,
.iterate_devices = dm_integrity_iterate_devices,
.io_hints = dm_integrity_io_hints,
};
static int __init dm_integrity_init(void)
{
int r;
journal_io_cache = kmem_cache_create("integrity_journal_io",
sizeof(struct journal_io), 0, 0, NULL);
if (!journal_io_cache) {
DMERR("can't allocate journal io cache");
return -ENOMEM;
}
r = dm_register_target(&integrity_target);
if (r < 0) {
kmem_cache_destroy(journal_io_cache);
return r;
}
return 0;
}
static void __exit dm_integrity_exit(void)
{
dm_unregister_target(&integrity_target);
kmem_cache_destroy(journal_io_cache);
}
module_init(dm_integrity_init);
module_exit(dm_integrity_exit);
MODULE_AUTHOR("Milan Broz");
MODULE_AUTHOR("Mikulas Patocka");
MODULE_DESCRIPTION(DM_NAME " target for integrity tags extension");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-integrity.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2001 Sistina Software (UK) Limited.
* Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
#include "dm-core.h"
#include "dm-rq.h"
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/blkdev.h>
#include <linux/blk-integrity.h>
#include <linux/namei.h>
#include <linux/ctype.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/atomic.h>
#include <linux/blk-mq.h>
#include <linux/mount.h>
#include <linux/dax.h>
#define DM_MSG_PREFIX "table"
#define NODE_SIZE L1_CACHE_BYTES
#define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
#define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
/*
* Similar to ceiling(log_size(n))
*/
static unsigned int int_log(unsigned int n, unsigned int base)
{
int result = 0;
while (n > 1) {
n = dm_div_up(n, base);
result++;
}
return result;
}
/*
* Calculate the index of the child node of the n'th node k'th key.
*/
static inline unsigned int get_child(unsigned int n, unsigned int k)
{
return (n * CHILDREN_PER_NODE) + k;
}
/*
* Return the n'th node of level l from table t.
*/
static inline sector_t *get_node(struct dm_table *t,
unsigned int l, unsigned int n)
{
return t->index[l] + (n * KEYS_PER_NODE);
}
/*
* Return the highest key that you could lookup from the n'th
* node on level l of the btree.
*/
static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
{
for (; l < t->depth - 1; l++)
n = get_child(n, CHILDREN_PER_NODE - 1);
if (n >= t->counts[l])
return (sector_t) -1;
return get_node(t, l, n)[KEYS_PER_NODE - 1];
}
/*
* Fills in a level of the btree based on the highs of the level
* below it.
*/
static int setup_btree_index(unsigned int l, struct dm_table *t)
{
unsigned int n, k;
sector_t *node;
for (n = 0U; n < t->counts[l]; n++) {
node = get_node(t, l, n);
for (k = 0U; k < KEYS_PER_NODE; k++)
node[k] = high(t, l + 1, get_child(n, k));
}
return 0;
}
/*
* highs, and targets are managed as dynamic arrays during a
* table load.
*/
static int alloc_targets(struct dm_table *t, unsigned int num)
{
sector_t *n_highs;
struct dm_target *n_targets;
/*
* Allocate both the target array and offset array at once.
*/
n_highs = kvcalloc(num, sizeof(struct dm_target) + sizeof(sector_t),
GFP_KERNEL);
if (!n_highs)
return -ENOMEM;
n_targets = (struct dm_target *) (n_highs + num);
memset(n_highs, -1, sizeof(*n_highs) * num);
kvfree(t->highs);
t->num_allocated = num;
t->highs = n_highs;
t->targets = n_targets;
return 0;
}
int dm_table_create(struct dm_table **result, blk_mode_t mode,
unsigned int num_targets, struct mapped_device *md)
{
struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
if (!t)
return -ENOMEM;
INIT_LIST_HEAD(&t->devices);
init_rwsem(&t->devices_lock);
if (!num_targets)
num_targets = KEYS_PER_NODE;
num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
if (!num_targets) {
kfree(t);
return -ENOMEM;
}
if (alloc_targets(t, num_targets)) {
kfree(t);
return -ENOMEM;
}
t->type = DM_TYPE_NONE;
t->mode = mode;
t->md = md;
*result = t;
return 0;
}
static void free_devices(struct list_head *devices, struct mapped_device *md)
{
struct list_head *tmp, *next;
list_for_each_safe(tmp, next, devices) {
struct dm_dev_internal *dd =
list_entry(tmp, struct dm_dev_internal, list);
DMWARN("%s: dm_table_destroy: dm_put_device call missing for %s",
dm_device_name(md), dd->dm_dev->name);
dm_put_table_device(md, dd->dm_dev);
kfree(dd);
}
}
static void dm_table_destroy_crypto_profile(struct dm_table *t);
void dm_table_destroy(struct dm_table *t)
{
if (!t)
return;
/* free the indexes */
if (t->depth >= 2)
kvfree(t->index[t->depth - 2]);
/* free the targets */
for (unsigned int i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
if (ti->type->dtr)
ti->type->dtr(ti);
dm_put_target_type(ti->type);
}
kvfree(t->highs);
/* free the device list */
free_devices(&t->devices, t->md);
dm_free_md_mempools(t->mempools);
dm_table_destroy_crypto_profile(t);
kfree(t);
}
/*
* See if we've already got a device in the list.
*/
static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
{
struct dm_dev_internal *dd;
list_for_each_entry(dd, l, list)
if (dd->dm_dev->bdev->bd_dev == dev)
return dd;
return NULL;
}
/*
* If possible, this checks an area of a destination device is invalid.
*/
static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
struct queue_limits *limits = data;
struct block_device *bdev = dev->bdev;
sector_t dev_size = bdev_nr_sectors(bdev);
unsigned short logical_block_size_sectors =
limits->logical_block_size >> SECTOR_SHIFT;
if (!dev_size)
return 0;
if ((start >= dev_size) || (start + len > dev_size)) {
DMERR("%s: %pg too small for target: start=%llu, len=%llu, dev_size=%llu",
dm_device_name(ti->table->md), bdev,
(unsigned long long)start,
(unsigned long long)len,
(unsigned long long)dev_size);
return 1;
}
/*
* If the target is mapped to zoned block device(s), check
* that the zones are not partially mapped.
*/
if (bdev_is_zoned(bdev)) {
unsigned int zone_sectors = bdev_zone_sectors(bdev);
if (start & (zone_sectors - 1)) {
DMERR("%s: start=%llu not aligned to h/w zone size %u of %pg",
dm_device_name(ti->table->md),
(unsigned long long)start,
zone_sectors, bdev);
return 1;
}
/*
* Note: The last zone of a zoned block device may be smaller
* than other zones. So for a target mapping the end of a
* zoned block device with such a zone, len would not be zone
* aligned. We do not allow such last smaller zone to be part
* of the mapping here to ensure that mappings with multiple
* devices do not end up with a smaller zone in the middle of
* the sector range.
*/
if (len & (zone_sectors - 1)) {
DMERR("%s: len=%llu not aligned to h/w zone size %u of %pg",
dm_device_name(ti->table->md),
(unsigned long long)len,
zone_sectors, bdev);
return 1;
}
}
if (logical_block_size_sectors <= 1)
return 0;
if (start & (logical_block_size_sectors - 1)) {
DMERR("%s: start=%llu not aligned to h/w logical block size %u of %pg",
dm_device_name(ti->table->md),
(unsigned long long)start,
limits->logical_block_size, bdev);
return 1;
}
if (len & (logical_block_size_sectors - 1)) {
DMERR("%s: len=%llu not aligned to h/w logical block size %u of %pg",
dm_device_name(ti->table->md),
(unsigned long long)len,
limits->logical_block_size, bdev);
return 1;
}
return 0;
}
/*
* This upgrades the mode on an already open dm_dev, being
* careful to leave things as they were if we fail to reopen the
* device and not to touch the existing bdev field in case
* it is accessed concurrently.
*/
static int upgrade_mode(struct dm_dev_internal *dd, blk_mode_t new_mode,
struct mapped_device *md)
{
int r;
struct dm_dev *old_dev, *new_dev;
old_dev = dd->dm_dev;
r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev,
dd->dm_dev->mode | new_mode, &new_dev);
if (r)
return r;
dd->dm_dev = new_dev;
dm_put_table_device(md, old_dev);
return 0;
}
/*
* Add a device to the list, or just increment the usage count if
* it's already present.
*
* Note: the __ref annotation is because this function can call the __init
* marked early_lookup_bdev when called during early boot code from dm-init.c.
*/
int __ref dm_get_device(struct dm_target *ti, const char *path, blk_mode_t mode,
struct dm_dev **result)
{
int r;
dev_t dev;
unsigned int major, minor;
char dummy;
struct dm_dev_internal *dd;
struct dm_table *t = ti->table;
BUG_ON(!t);
if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
/* Extract the major/minor numbers */
dev = MKDEV(major, minor);
if (MAJOR(dev) != major || MINOR(dev) != minor)
return -EOVERFLOW;
} else {
r = lookup_bdev(path, &dev);
#ifndef MODULE
if (r && system_state < SYSTEM_RUNNING)
r = early_lookup_bdev(path, &dev);
#endif
if (r)
return r;
}
if (dev == disk_devt(t->md->disk))
return -EINVAL;
down_write(&t->devices_lock);
dd = find_device(&t->devices, dev);
if (!dd) {
dd = kmalloc(sizeof(*dd), GFP_KERNEL);
if (!dd) {
r = -ENOMEM;
goto unlock_ret_r;
}
r = dm_get_table_device(t->md, dev, mode, &dd->dm_dev);
if (r) {
kfree(dd);
goto unlock_ret_r;
}
refcount_set(&dd->count, 1);
list_add(&dd->list, &t->devices);
goto out;
} else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) {
r = upgrade_mode(dd, mode, t->md);
if (r)
goto unlock_ret_r;
}
refcount_inc(&dd->count);
out:
up_write(&t->devices_lock);
*result = dd->dm_dev;
return 0;
unlock_ret_r:
up_write(&t->devices_lock);
return r;
}
EXPORT_SYMBOL(dm_get_device);
static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
struct queue_limits *limits = data;
struct block_device *bdev = dev->bdev;
struct request_queue *q = bdev_get_queue(bdev);
if (unlikely(!q)) {
DMWARN("%s: Cannot set limits for nonexistent device %pg",
dm_device_name(ti->table->md), bdev);
return 0;
}
if (blk_stack_limits(limits, &q->limits,
get_start_sect(bdev) + start) < 0)
DMWARN("%s: adding target device %pg caused an alignment inconsistency: "
"physical_block_size=%u, logical_block_size=%u, "
"alignment_offset=%u, start=%llu",
dm_device_name(ti->table->md), bdev,
q->limits.physical_block_size,
q->limits.logical_block_size,
q->limits.alignment_offset,
(unsigned long long) start << SECTOR_SHIFT);
return 0;
}
/*
* Decrement a device's use count and remove it if necessary.
*/
void dm_put_device(struct dm_target *ti, struct dm_dev *d)
{
int found = 0;
struct dm_table *t = ti->table;
struct list_head *devices = &t->devices;
struct dm_dev_internal *dd;
down_write(&t->devices_lock);
list_for_each_entry(dd, devices, list) {
if (dd->dm_dev == d) {
found = 1;
break;
}
}
if (!found) {
DMERR("%s: device %s not in table devices list",
dm_device_name(t->md), d->name);
goto unlock_ret;
}
if (refcount_dec_and_test(&dd->count)) {
dm_put_table_device(t->md, d);
list_del(&dd->list);
kfree(dd);
}
unlock_ret:
up_write(&t->devices_lock);
}
EXPORT_SYMBOL(dm_put_device);
/*
* Checks to see if the target joins onto the end of the table.
*/
static int adjoin(struct dm_table *t, struct dm_target *ti)
{
struct dm_target *prev;
if (!t->num_targets)
return !ti->begin;
prev = &t->targets[t->num_targets - 1];
return (ti->begin == (prev->begin + prev->len));
}
/*
* Used to dynamically allocate the arg array.
*
* We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
* process messages even if some device is suspended. These messages have a
* small fixed number of arguments.
*
* On the other hand, dm-switch needs to process bulk data using messages and
* excessive use of GFP_NOIO could cause trouble.
*/
static char **realloc_argv(unsigned int *size, char **old_argv)
{
char **argv;
unsigned int new_size;
gfp_t gfp;
if (*size) {
new_size = *size * 2;
gfp = GFP_KERNEL;
} else {
new_size = 8;
gfp = GFP_NOIO;
}
argv = kmalloc_array(new_size, sizeof(*argv), gfp);
if (argv && old_argv) {
memcpy(argv, old_argv, *size * sizeof(*argv));
*size = new_size;
}
kfree(old_argv);
return argv;
}
/*
* Destructively splits up the argument list to pass to ctr.
*/
int dm_split_args(int *argc, char ***argvp, char *input)
{
char *start, *end = input, *out, **argv = NULL;
unsigned int array_size = 0;
*argc = 0;
if (!input) {
*argvp = NULL;
return 0;
}
argv = realloc_argv(&array_size, argv);
if (!argv)
return -ENOMEM;
while (1) {
/* Skip whitespace */
start = skip_spaces(end);
if (!*start)
break; /* success, we hit the end */
/* 'out' is used to remove any back-quotes */
end = out = start;
while (*end) {
/* Everything apart from '\0' can be quoted */
if (*end == '\\' && *(end + 1)) {
*out++ = *(end + 1);
end += 2;
continue;
}
if (isspace(*end))
break; /* end of token */
*out++ = *end++;
}
/* have we already filled the array ? */
if ((*argc + 1) > array_size) {
argv = realloc_argv(&array_size, argv);
if (!argv)
return -ENOMEM;
}
/* we know this is whitespace */
if (*end)
end++;
/* terminate the string and put it in the array */
*out = '\0';
argv[*argc] = start;
(*argc)++;
}
*argvp = argv;
return 0;
}
/*
* Impose necessary and sufficient conditions on a devices's table such
* that any incoming bio which respects its logical_block_size can be
* processed successfully. If it falls across the boundary between
* two or more targets, the size of each piece it gets split into must
* be compatible with the logical_block_size of the target processing it.
*/
static int validate_hardware_logical_block_alignment(struct dm_table *t,
struct queue_limits *limits)
{
/*
* This function uses arithmetic modulo the logical_block_size
* (in units of 512-byte sectors).
*/
unsigned short device_logical_block_size_sects =
limits->logical_block_size >> SECTOR_SHIFT;
/*
* Offset of the start of the next table entry, mod logical_block_size.
*/
unsigned short next_target_start = 0;
/*
* Given an aligned bio that extends beyond the end of a
* target, how many sectors must the next target handle?
*/
unsigned short remaining = 0;
struct dm_target *ti;
struct queue_limits ti_limits;
unsigned int i;
/*
* Check each entry in the table in turn.
*/
for (i = 0; i < t->num_targets; i++) {
ti = dm_table_get_target(t, i);
blk_set_stacking_limits(&ti_limits);
/* combine all target devices' limits */
if (ti->type->iterate_devices)
ti->type->iterate_devices(ti, dm_set_device_limits,
&ti_limits);
/*
* If the remaining sectors fall entirely within this
* table entry are they compatible with its logical_block_size?
*/
if (remaining < ti->len &&
remaining & ((ti_limits.logical_block_size >>
SECTOR_SHIFT) - 1))
break; /* Error */
next_target_start =
(unsigned short) ((next_target_start + ti->len) &
(device_logical_block_size_sects - 1));
remaining = next_target_start ?
device_logical_block_size_sects - next_target_start : 0;
}
if (remaining) {
DMERR("%s: table line %u (start sect %llu len %llu) "
"not aligned to h/w logical block size %u",
dm_device_name(t->md), i,
(unsigned long long) ti->begin,
(unsigned long long) ti->len,
limits->logical_block_size);
return -EINVAL;
}
return 0;
}
int dm_table_add_target(struct dm_table *t, const char *type,
sector_t start, sector_t len, char *params)
{
int r = -EINVAL, argc;
char **argv;
struct dm_target *ti;
if (t->singleton) {
DMERR("%s: target type %s must appear alone in table",
dm_device_name(t->md), t->targets->type->name);
return -EINVAL;
}
BUG_ON(t->num_targets >= t->num_allocated);
ti = t->targets + t->num_targets;
memset(ti, 0, sizeof(*ti));
if (!len) {
DMERR("%s: zero-length target", dm_device_name(t->md));
return -EINVAL;
}
ti->type = dm_get_target_type(type);
if (!ti->type) {
DMERR("%s: %s: unknown target type", dm_device_name(t->md), type);
return -EINVAL;
}
if (dm_target_needs_singleton(ti->type)) {
if (t->num_targets) {
ti->error = "singleton target type must appear alone in table";
goto bad;
}
t->singleton = true;
}
if (dm_target_always_writeable(ti->type) &&
!(t->mode & BLK_OPEN_WRITE)) {
ti->error = "target type may not be included in a read-only table";
goto bad;
}
if (t->immutable_target_type) {
if (t->immutable_target_type != ti->type) {
ti->error = "immutable target type cannot be mixed with other target types";
goto bad;
}
} else if (dm_target_is_immutable(ti->type)) {
if (t->num_targets) {
ti->error = "immutable target type cannot be mixed with other target types";
goto bad;
}
t->immutable_target_type = ti->type;
}
if (dm_target_has_integrity(ti->type))
t->integrity_added = 1;
ti->table = t;
ti->begin = start;
ti->len = len;
ti->error = "Unknown error";
/*
* Does this target adjoin the previous one ?
*/
if (!adjoin(t, ti)) {
ti->error = "Gap in table";
goto bad;
}
r = dm_split_args(&argc, &argv, params);
if (r) {
ti->error = "couldn't split parameters";
goto bad;
}
r = ti->type->ctr(ti, argc, argv);
kfree(argv);
if (r)
goto bad;
t->highs[t->num_targets++] = ti->begin + ti->len - 1;
if (!ti->num_discard_bios && ti->discards_supported)
DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
dm_device_name(t->md), type);
if (ti->limit_swap_bios && !static_key_enabled(&swap_bios_enabled.key))
static_branch_enable(&swap_bios_enabled);
return 0;
bad:
DMERR("%s: %s: %s (%pe)", dm_device_name(t->md), type, ti->error, ERR_PTR(r));
dm_put_target_type(ti->type);
return r;
}
/*
* Target argument parsing helpers.
*/
static int validate_next_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
unsigned int *value, char **error, unsigned int grouped)
{
const char *arg_str = dm_shift_arg(arg_set);
char dummy;
if (!arg_str ||
(sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
(*value < arg->min) ||
(*value > arg->max) ||
(grouped && arg_set->argc < *value)) {
*error = arg->error;
return -EINVAL;
}
return 0;
}
int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
unsigned int *value, char **error)
{
return validate_next_arg(arg, arg_set, value, error, 0);
}
EXPORT_SYMBOL(dm_read_arg);
int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
unsigned int *value, char **error)
{
return validate_next_arg(arg, arg_set, value, error, 1);
}
EXPORT_SYMBOL(dm_read_arg_group);
const char *dm_shift_arg(struct dm_arg_set *as)
{
char *r;
if (as->argc) {
as->argc--;
r = *as->argv;
as->argv++;
return r;
}
return NULL;
}
EXPORT_SYMBOL(dm_shift_arg);
void dm_consume_args(struct dm_arg_set *as, unsigned int num_args)
{
BUG_ON(as->argc < num_args);
as->argc -= num_args;
as->argv += num_args;
}
EXPORT_SYMBOL(dm_consume_args);
static bool __table_type_bio_based(enum dm_queue_mode table_type)
{
return (table_type == DM_TYPE_BIO_BASED ||
table_type == DM_TYPE_DAX_BIO_BASED);
}
static bool __table_type_request_based(enum dm_queue_mode table_type)
{
return table_type == DM_TYPE_REQUEST_BASED;
}
void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
{
t->type = type;
}
EXPORT_SYMBOL_GPL(dm_table_set_type);
/* validate the dax capability of the target device span */
static int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
if (dev->dax_dev)
return false;
DMDEBUG("%pg: error: dax unsupported by block device", dev->bdev);
return true;
}
/* Check devices support synchronous DAX */
static int device_not_dax_synchronous_capable(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
return !dev->dax_dev || !dax_synchronous(dev->dax_dev);
}
static bool dm_table_supports_dax(struct dm_table *t,
iterate_devices_callout_fn iterate_fn)
{
/* Ensure that all targets support DAX. */
for (unsigned int i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
if (!ti->type->direct_access)
return false;
if (!ti->type->iterate_devices ||
ti->type->iterate_devices(ti, iterate_fn, NULL))
return false;
}
return true;
}
static int device_is_rq_stackable(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
struct block_device *bdev = dev->bdev;
struct request_queue *q = bdev_get_queue(bdev);
/* request-based cannot stack on partitions! */
if (bdev_is_partition(bdev))
return false;
return queue_is_mq(q);
}
static int dm_table_determine_type(struct dm_table *t)
{
unsigned int bio_based = 0, request_based = 0, hybrid = 0;
struct dm_target *ti;
struct list_head *devices = dm_table_get_devices(t);
enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
if (t->type != DM_TYPE_NONE) {
/* target already set the table's type */
if (t->type == DM_TYPE_BIO_BASED) {
/* possibly upgrade to a variant of bio-based */
goto verify_bio_based;
}
BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
goto verify_rq_based;
}
for (unsigned int i = 0; i < t->num_targets; i++) {
ti = dm_table_get_target(t, i);
if (dm_target_hybrid(ti))
hybrid = 1;
else if (dm_target_request_based(ti))
request_based = 1;
else
bio_based = 1;
if (bio_based && request_based) {
DMERR("Inconsistent table: different target types can't be mixed up");
return -EINVAL;
}
}
if (hybrid && !bio_based && !request_based) {
/*
* The targets can work either way.
* Determine the type from the live device.
* Default to bio-based if device is new.
*/
if (__table_type_request_based(live_md_type))
request_based = 1;
else
bio_based = 1;
}
if (bio_based) {
verify_bio_based:
/* We must use this table as bio-based */
t->type = DM_TYPE_BIO_BASED;
if (dm_table_supports_dax(t, device_not_dax_capable) ||
(list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
t->type = DM_TYPE_DAX_BIO_BASED;
}
return 0;
}
BUG_ON(!request_based); /* No targets in this table */
t->type = DM_TYPE_REQUEST_BASED;
verify_rq_based:
/*
* Request-based dm supports only tables that have a single target now.
* To support multiple targets, request splitting support is needed,
* and that needs lots of changes in the block-layer.
* (e.g. request completion process for partial completion.)
*/
if (t->num_targets > 1) {
DMERR("request-based DM doesn't support multiple targets");
return -EINVAL;
}
if (list_empty(devices)) {
int srcu_idx;
struct dm_table *live_table = dm_get_live_table(t->md, &srcu_idx);
/* inherit live table's type */
if (live_table)
t->type = live_table->type;
dm_put_live_table(t->md, srcu_idx);
return 0;
}
ti = dm_table_get_immutable_target(t);
if (!ti) {
DMERR("table load rejected: immutable target is required");
return -EINVAL;
} else if (ti->max_io_len) {
DMERR("table load rejected: immutable target that splits IO is not supported");
return -EINVAL;
}
/* Non-request-stackable devices can't be used for request-based dm */
if (!ti->type->iterate_devices ||
!ti->type->iterate_devices(ti, device_is_rq_stackable, NULL)) {
DMERR("table load rejected: including non-request-stackable devices");
return -EINVAL;
}
return 0;
}
enum dm_queue_mode dm_table_get_type(struct dm_table *t)
{
return t->type;
}
struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
{
return t->immutable_target_type;
}
struct dm_target *dm_table_get_immutable_target(struct dm_table *t)
{
/* Immutable target is implicitly a singleton */
if (t->num_targets > 1 ||
!dm_target_is_immutable(t->targets[0].type))
return NULL;
return t->targets;
}
struct dm_target *dm_table_get_wildcard_target(struct dm_table *t)
{
for (unsigned int i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
if (dm_target_is_wildcard(ti->type))
return ti;
}
return NULL;
}
bool dm_table_bio_based(struct dm_table *t)
{
return __table_type_bio_based(dm_table_get_type(t));
}
bool dm_table_request_based(struct dm_table *t)
{
return __table_type_request_based(dm_table_get_type(t));
}
static bool dm_table_supports_poll(struct dm_table *t);
static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
{
enum dm_queue_mode type = dm_table_get_type(t);
unsigned int per_io_data_size = 0, front_pad, io_front_pad;
unsigned int min_pool_size = 0, pool_size;
struct dm_md_mempools *pools;
if (unlikely(type == DM_TYPE_NONE)) {
DMERR("no table type is set, can't allocate mempools");
return -EINVAL;
}
pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
if (!pools)
return -ENOMEM;
if (type == DM_TYPE_REQUEST_BASED) {
pool_size = dm_get_reserved_rq_based_ios();
front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
goto init_bs;
}
for (unsigned int i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
per_io_data_size = max(per_io_data_size, ti->per_io_data_size);
min_pool_size = max(min_pool_size, ti->num_flush_bios);
}
pool_size = max(dm_get_reserved_bio_based_ios(), min_pool_size);
front_pad = roundup(per_io_data_size,
__alignof__(struct dm_target_io)) + DM_TARGET_IO_BIO_OFFSET;
io_front_pad = roundup(per_io_data_size,
__alignof__(struct dm_io)) + DM_IO_BIO_OFFSET;
if (bioset_init(&pools->io_bs, pool_size, io_front_pad,
dm_table_supports_poll(t) ? BIOSET_PERCPU_CACHE : 0))
goto out_free_pools;
if (t->integrity_supported &&
bioset_integrity_create(&pools->io_bs, pool_size))
goto out_free_pools;
init_bs:
if (bioset_init(&pools->bs, pool_size, front_pad, 0))
goto out_free_pools;
if (t->integrity_supported &&
bioset_integrity_create(&pools->bs, pool_size))
goto out_free_pools;
t->mempools = pools;
return 0;
out_free_pools:
dm_free_md_mempools(pools);
return -ENOMEM;
}
static int setup_indexes(struct dm_table *t)
{
int i;
unsigned int total = 0;
sector_t *indexes;
/* allocate the space for *all* the indexes */
for (i = t->depth - 2; i >= 0; i--) {
t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
total += t->counts[i];
}
indexes = kvcalloc(total, NODE_SIZE, GFP_KERNEL);
if (!indexes)
return -ENOMEM;
/* set up internal nodes, bottom-up */
for (i = t->depth - 2; i >= 0; i--) {
t->index[i] = indexes;
indexes += (KEYS_PER_NODE * t->counts[i]);
setup_btree_index(i, t);
}
return 0;
}
/*
* Builds the btree to index the map.
*/
static int dm_table_build_index(struct dm_table *t)
{
int r = 0;
unsigned int leaf_nodes;
/* how many indexes will the btree have ? */
leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
/* leaf layer has already been set up */
t->counts[t->depth - 1] = leaf_nodes;
t->index[t->depth - 1] = t->highs;
if (t->depth >= 2)
r = setup_indexes(t);
return r;
}
static bool integrity_profile_exists(struct gendisk *disk)
{
return !!blk_get_integrity(disk);
}
/*
* Get a disk whose integrity profile reflects the table's profile.
* Returns NULL if integrity support was inconsistent or unavailable.
*/
static struct gendisk *dm_table_get_integrity_disk(struct dm_table *t)
{
struct list_head *devices = dm_table_get_devices(t);
struct dm_dev_internal *dd = NULL;
struct gendisk *prev_disk = NULL, *template_disk = NULL;
for (unsigned int i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
if (!dm_target_passes_integrity(ti->type))
goto no_integrity;
}
list_for_each_entry(dd, devices, list) {
template_disk = dd->dm_dev->bdev->bd_disk;
if (!integrity_profile_exists(template_disk))
goto no_integrity;
else if (prev_disk &&
blk_integrity_compare(prev_disk, template_disk) < 0)
goto no_integrity;
prev_disk = template_disk;
}
return template_disk;
no_integrity:
if (prev_disk)
DMWARN("%s: integrity not set: %s and %s profile mismatch",
dm_device_name(t->md),
prev_disk->disk_name,
template_disk->disk_name);
return NULL;
}
/*
* Register the mapped device for blk_integrity support if the
* underlying devices have an integrity profile. But all devices may
* not have matching profiles (checking all devices isn't reliable
* during table load because this table may use other DM device(s) which
* must be resumed before they will have an initialized integity
* profile). Consequently, stacked DM devices force a 2 stage integrity
* profile validation: First pass during table load, final pass during
* resume.
*/
static int dm_table_register_integrity(struct dm_table *t)
{
struct mapped_device *md = t->md;
struct gendisk *template_disk = NULL;
/* If target handles integrity itself do not register it here. */
if (t->integrity_added)
return 0;
template_disk = dm_table_get_integrity_disk(t);
if (!template_disk)
return 0;
if (!integrity_profile_exists(dm_disk(md))) {
t->integrity_supported = true;
/*
* Register integrity profile during table load; we can do
* this because the final profile must match during resume.
*/
blk_integrity_register(dm_disk(md),
blk_get_integrity(template_disk));
return 0;
}
/*
* If DM device already has an initialized integrity
* profile the new profile should not conflict.
*/
if (blk_integrity_compare(dm_disk(md), template_disk) < 0) {
DMERR("%s: conflict with existing integrity profile: %s profile mismatch",
dm_device_name(t->md),
template_disk->disk_name);
return 1;
}
/* Preserve existing integrity profile */
t->integrity_supported = true;
return 0;
}
#ifdef CONFIG_BLK_INLINE_ENCRYPTION
struct dm_crypto_profile {
struct blk_crypto_profile profile;
struct mapped_device *md;
};
static int dm_keyslot_evict_callback(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
const struct blk_crypto_key *key = data;
blk_crypto_evict_key(dev->bdev, key);
return 0;
}
/*
* When an inline encryption key is evicted from a device-mapper device, evict
* it from all the underlying devices.
*/
static int dm_keyslot_evict(struct blk_crypto_profile *profile,
const struct blk_crypto_key *key, unsigned int slot)
{
struct mapped_device *md =
container_of(profile, struct dm_crypto_profile, profile)->md;
struct dm_table *t;
int srcu_idx;
t = dm_get_live_table(md, &srcu_idx);
if (!t)
return 0;
for (unsigned int i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
if (!ti->type->iterate_devices)
continue;
ti->type->iterate_devices(ti, dm_keyslot_evict_callback,
(void *)key);
}
dm_put_live_table(md, srcu_idx);
return 0;
}
static int
device_intersect_crypto_capabilities(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
struct blk_crypto_profile *parent = data;
struct blk_crypto_profile *child =
bdev_get_queue(dev->bdev)->crypto_profile;
blk_crypto_intersect_capabilities(parent, child);
return 0;
}
void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
{
struct dm_crypto_profile *dmcp = container_of(profile,
struct dm_crypto_profile,
profile);
if (!profile)
return;
blk_crypto_profile_destroy(profile);
kfree(dmcp);
}
static void dm_table_destroy_crypto_profile(struct dm_table *t)
{
dm_destroy_crypto_profile(t->crypto_profile);
t->crypto_profile = NULL;
}
/*
* Constructs and initializes t->crypto_profile with a crypto profile that
* represents the common set of crypto capabilities of the devices described by
* the dm_table. However, if the constructed crypto profile doesn't support all
* crypto capabilities that are supported by the current mapped_device, it
* returns an error instead, since we don't support removing crypto capabilities
* on table changes. Finally, if the constructed crypto profile is "empty" (has
* no crypto capabilities at all), it just sets t->crypto_profile to NULL.
*/
static int dm_table_construct_crypto_profile(struct dm_table *t)
{
struct dm_crypto_profile *dmcp;
struct blk_crypto_profile *profile;
unsigned int i;
bool empty_profile = true;
dmcp = kmalloc(sizeof(*dmcp), GFP_KERNEL);
if (!dmcp)
return -ENOMEM;
dmcp->md = t->md;
profile = &dmcp->profile;
blk_crypto_profile_init(profile, 0);
profile->ll_ops.keyslot_evict = dm_keyslot_evict;
profile->max_dun_bytes_supported = UINT_MAX;
memset(profile->modes_supported, 0xFF,
sizeof(profile->modes_supported));
for (i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
if (!dm_target_passes_crypto(ti->type)) {
blk_crypto_intersect_capabilities(profile, NULL);
break;
}
if (!ti->type->iterate_devices)
continue;
ti->type->iterate_devices(ti,
device_intersect_crypto_capabilities,
profile);
}
if (t->md->queue &&
!blk_crypto_has_capabilities(profile,
t->md->queue->crypto_profile)) {
DMERR("Inline encryption capabilities of new DM table were more restrictive than the old table's. This is not supported!");
dm_destroy_crypto_profile(profile);
return -EINVAL;
}
/*
* If the new profile doesn't actually support any crypto capabilities,
* we may as well represent it with a NULL profile.
*/
for (i = 0; i < ARRAY_SIZE(profile->modes_supported); i++) {
if (profile->modes_supported[i]) {
empty_profile = false;
break;
}
}
if (empty_profile) {
dm_destroy_crypto_profile(profile);
profile = NULL;
}
/*
* t->crypto_profile is only set temporarily while the table is being
* set up, and it gets set to NULL after the profile has been
* transferred to the request_queue.
*/
t->crypto_profile = profile;
return 0;
}
static void dm_update_crypto_profile(struct request_queue *q,
struct dm_table *t)
{
if (!t->crypto_profile)
return;
/* Make the crypto profile less restrictive. */
if (!q->crypto_profile) {
blk_crypto_register(t->crypto_profile, q);
} else {
blk_crypto_update_capabilities(q->crypto_profile,
t->crypto_profile);
dm_destroy_crypto_profile(t->crypto_profile);
}
t->crypto_profile = NULL;
}
#else /* CONFIG_BLK_INLINE_ENCRYPTION */
static int dm_table_construct_crypto_profile(struct dm_table *t)
{
return 0;
}
void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
{
}
static void dm_table_destroy_crypto_profile(struct dm_table *t)
{
}
static void dm_update_crypto_profile(struct request_queue *q,
struct dm_table *t)
{
}
#endif /* !CONFIG_BLK_INLINE_ENCRYPTION */
/*
* Prepares the table for use by building the indices,
* setting the type, and allocating mempools.
*/
int dm_table_complete(struct dm_table *t)
{
int r;
r = dm_table_determine_type(t);
if (r) {
DMERR("unable to determine table type");
return r;
}
r = dm_table_build_index(t);
if (r) {
DMERR("unable to build btrees");
return r;
}
r = dm_table_register_integrity(t);
if (r) {
DMERR("could not register integrity profile.");
return r;
}
r = dm_table_construct_crypto_profile(t);
if (r) {
DMERR("could not construct crypto profile.");
return r;
}
r = dm_table_alloc_md_mempools(t, t->md);
if (r)
DMERR("unable to allocate mempools");
return r;
}
static DEFINE_MUTEX(_event_lock);
void dm_table_event_callback(struct dm_table *t,
void (*fn)(void *), void *context)
{
mutex_lock(&_event_lock);
t->event_fn = fn;
t->event_context = context;
mutex_unlock(&_event_lock);
}
void dm_table_event(struct dm_table *t)
{
mutex_lock(&_event_lock);
if (t->event_fn)
t->event_fn(t->event_context);
mutex_unlock(&_event_lock);
}
EXPORT_SYMBOL(dm_table_event);
inline sector_t dm_table_get_size(struct dm_table *t)
{
return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
}
EXPORT_SYMBOL(dm_table_get_size);
/*
* Search the btree for the correct target.
*
* Caller should check returned pointer for NULL
* to trap I/O beyond end of device.
*/
struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
{
unsigned int l, n = 0, k = 0;
sector_t *node;
if (unlikely(sector >= dm_table_get_size(t)))
return NULL;
for (l = 0; l < t->depth; l++) {
n = get_child(n, k);
node = get_node(t, l, n);
for (k = 0; k < KEYS_PER_NODE; k++)
if (node[k] >= sector)
break;
}
return &t->targets[(KEYS_PER_NODE * n) + k];
}
static int device_not_poll_capable(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
struct request_queue *q = bdev_get_queue(dev->bdev);
return !test_bit(QUEUE_FLAG_POLL, &q->queue_flags);
}
/*
* type->iterate_devices() should be called when the sanity check needs to
* iterate and check all underlying data devices. iterate_devices() will
* iterate all underlying data devices until it encounters a non-zero return
* code, returned by whether the input iterate_devices_callout_fn, or
* iterate_devices() itself internally.
*
* For some target type (e.g. dm-stripe), one call of iterate_devices() may
* iterate multiple underlying devices internally, in which case a non-zero
* return code returned by iterate_devices_callout_fn will stop the iteration
* in advance.
*
* Cases requiring _any_ underlying device supporting some kind of attribute,
* should use the iteration structure like dm_table_any_dev_attr(), or call
* it directly. @func should handle semantics of positive examples, e.g.
* capable of something.
*
* Cases requiring _all_ underlying devices supporting some kind of attribute,
* should use the iteration structure like dm_table_supports_nowait() or
* dm_table_supports_discards(). Or introduce dm_table_all_devs_attr() that
* uses an @anti_func that handle semantics of counter examples, e.g. not
* capable of something. So: return !dm_table_any_dev_attr(t, anti_func, data);
*/
static bool dm_table_any_dev_attr(struct dm_table *t,
iterate_devices_callout_fn func, void *data)
{
for (unsigned int i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
if (ti->type->iterate_devices &&
ti->type->iterate_devices(ti, func, data))
return true;
}
return false;
}
static int count_device(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
unsigned int *num_devices = data;
(*num_devices)++;
return 0;
}
static bool dm_table_supports_poll(struct dm_table *t)
{
for (unsigned int i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
if (!ti->type->iterate_devices ||
ti->type->iterate_devices(ti, device_not_poll_capable, NULL))
return false;
}
return true;
}
/*
* Check whether a table has no data devices attached using each
* target's iterate_devices method.
* Returns false if the result is unknown because a target doesn't
* support iterate_devices.
*/
bool dm_table_has_no_data_devices(struct dm_table *t)
{
for (unsigned int i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
unsigned int num_devices = 0;
if (!ti->type->iterate_devices)
return false;
ti->type->iterate_devices(ti, count_device, &num_devices);
if (num_devices)
return false;
}
return true;
}
static int device_not_zoned_model(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
struct request_queue *q = bdev_get_queue(dev->bdev);
enum blk_zoned_model *zoned_model = data;
return blk_queue_zoned_model(q) != *zoned_model;
}
/*
* Check the device zoned model based on the target feature flag. If the target
* has the DM_TARGET_ZONED_HM feature flag set, host-managed zoned devices are
* also accepted but all devices must have the same zoned model. If the target
* has the DM_TARGET_MIXED_ZONED_MODEL feature set, the devices can have any
* zoned model with all zoned devices having the same zone size.
*/
static bool dm_table_supports_zoned_model(struct dm_table *t,
enum blk_zoned_model zoned_model)
{
for (unsigned int i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
if (dm_target_supports_zoned_hm(ti->type)) {
if (!ti->type->iterate_devices ||
ti->type->iterate_devices(ti, device_not_zoned_model,
&zoned_model))
return false;
} else if (!dm_target_supports_mixed_zoned_model(ti->type)) {
if (zoned_model == BLK_ZONED_HM)
return false;
}
}
return true;
}
static int device_not_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
unsigned int *zone_sectors = data;
if (!bdev_is_zoned(dev->bdev))
return 0;
return bdev_zone_sectors(dev->bdev) != *zone_sectors;
}
/*
* Check consistency of zoned model and zone sectors across all targets. For
* zone sectors, if the destination device is a zoned block device, it shall
* have the specified zone_sectors.
*/
static int validate_hardware_zoned_model(struct dm_table *t,
enum blk_zoned_model zoned_model,
unsigned int zone_sectors)
{
if (zoned_model == BLK_ZONED_NONE)
return 0;
if (!dm_table_supports_zoned_model(t, zoned_model)) {
DMERR("%s: zoned model is not consistent across all devices",
dm_device_name(t->md));
return -EINVAL;
}
/* Check zone size validity and compatibility */
if (!zone_sectors || !is_power_of_2(zone_sectors))
return -EINVAL;
if (dm_table_any_dev_attr(t, device_not_matches_zone_sectors, &zone_sectors)) {
DMERR("%s: zone sectors is not consistent across all zoned devices",
dm_device_name(t->md));
return -EINVAL;
}
return 0;
}
/*
* Establish the new table's queue_limits and validate them.
*/
int dm_calculate_queue_limits(struct dm_table *t,
struct queue_limits *limits)
{
struct queue_limits ti_limits;
enum blk_zoned_model zoned_model = BLK_ZONED_NONE;
unsigned int zone_sectors = 0;
blk_set_stacking_limits(limits);
for (unsigned int i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
blk_set_stacking_limits(&ti_limits);
if (!ti->type->iterate_devices) {
/* Set I/O hints portion of queue limits */
if (ti->type->io_hints)
ti->type->io_hints(ti, &ti_limits);
goto combine_limits;
}
/*
* Combine queue limits of all the devices this target uses.
*/
ti->type->iterate_devices(ti, dm_set_device_limits,
&ti_limits);
if (zoned_model == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
/*
* After stacking all limits, validate all devices
* in table support this zoned model and zone sectors.
*/
zoned_model = ti_limits.zoned;
zone_sectors = ti_limits.chunk_sectors;
}
/* Set I/O hints portion of queue limits */
if (ti->type->io_hints)
ti->type->io_hints(ti, &ti_limits);
/*
* Check each device area is consistent with the target's
* overall queue limits.
*/
if (ti->type->iterate_devices(ti, device_area_is_invalid,
&ti_limits))
return -EINVAL;
combine_limits:
/*
* Merge this target's queue limits into the overall limits
* for the table.
*/
if (blk_stack_limits(limits, &ti_limits, 0) < 0)
DMWARN("%s: adding target device (start sect %llu len %llu) "
"caused an alignment inconsistency",
dm_device_name(t->md),
(unsigned long long) ti->begin,
(unsigned long long) ti->len);
}
/*
* Verify that the zoned model and zone sectors, as determined before
* any .io_hints override, are the same across all devices in the table.
* - this is especially relevant if .io_hints is emulating a disk-managed
* zoned model (aka BLK_ZONED_NONE) on host-managed zoned block devices.
* BUT...
*/
if (limits->zoned != BLK_ZONED_NONE) {
/*
* ...IF the above limits stacking determined a zoned model
* validate that all of the table's devices conform to it.
*/
zoned_model = limits->zoned;
zone_sectors = limits->chunk_sectors;
}
if (validate_hardware_zoned_model(t, zoned_model, zone_sectors))
return -EINVAL;
return validate_hardware_logical_block_alignment(t, limits);
}
/*
* Verify that all devices have an integrity profile that matches the
* DM device's registered integrity profile. If the profiles don't
* match then unregister the DM device's integrity profile.
*/
static void dm_table_verify_integrity(struct dm_table *t)
{
struct gendisk *template_disk = NULL;
if (t->integrity_added)
return;
if (t->integrity_supported) {
/*
* Verify that the original integrity profile
* matches all the devices in this table.
*/
template_disk = dm_table_get_integrity_disk(t);
if (template_disk &&
blk_integrity_compare(dm_disk(t->md), template_disk) >= 0)
return;
}
if (integrity_profile_exists(dm_disk(t->md))) {
DMWARN("%s: unable to establish an integrity profile",
dm_device_name(t->md));
blk_integrity_unregister(dm_disk(t->md));
}
}
static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
unsigned long flush = (unsigned long) data;
struct request_queue *q = bdev_get_queue(dev->bdev);
return (q->queue_flags & flush);
}
static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush)
{
/*
* Require at least one underlying device to support flushes.
* t->devices includes internal dm devices such as mirror logs
* so we need to use iterate_devices here, which targets
* supporting flushes must provide.
*/
for (unsigned int i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
if (!ti->num_flush_bios)
continue;
if (ti->flush_supported)
return true;
if (ti->type->iterate_devices &&
ti->type->iterate_devices(ti, device_flush_capable, (void *) flush))
return true;
}
return false;
}
static int device_dax_write_cache_enabled(struct dm_target *ti,
struct dm_dev *dev, sector_t start,
sector_t len, void *data)
{
struct dax_device *dax_dev = dev->dax_dev;
if (!dax_dev)
return false;
if (dax_write_cache_enabled(dax_dev))
return true;
return false;
}
static int device_is_rotational(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
return !bdev_nonrot(dev->bdev);
}
static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
struct request_queue *q = bdev_get_queue(dev->bdev);
return !blk_queue_add_random(q);
}
static int device_not_write_zeroes_capable(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
struct request_queue *q = bdev_get_queue(dev->bdev);
return !q->limits.max_write_zeroes_sectors;
}
static bool dm_table_supports_write_zeroes(struct dm_table *t)
{
for (unsigned int i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
if (!ti->num_write_zeroes_bios)
return false;
if (!ti->type->iterate_devices ||
ti->type->iterate_devices(ti, device_not_write_zeroes_capable, NULL))
return false;
}
return true;
}
static int device_not_nowait_capable(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
return !bdev_nowait(dev->bdev);
}
static bool dm_table_supports_nowait(struct dm_table *t)
{
for (unsigned int i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
if (!dm_target_supports_nowait(ti->type))
return false;
if (!ti->type->iterate_devices ||
ti->type->iterate_devices(ti, device_not_nowait_capable, NULL))
return false;
}
return true;
}
static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
return !bdev_max_discard_sectors(dev->bdev);
}
static bool dm_table_supports_discards(struct dm_table *t)
{
for (unsigned int i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
if (!ti->num_discard_bios)
return false;
/*
* Either the target provides discard support (as implied by setting
* 'discards_supported') or it relies on _all_ data devices having
* discard support.
*/
if (!ti->discards_supported &&
(!ti->type->iterate_devices ||
ti->type->iterate_devices(ti, device_not_discard_capable, NULL)))
return false;
}
return true;
}
static int device_not_secure_erase_capable(struct dm_target *ti,
struct dm_dev *dev, sector_t start,
sector_t len, void *data)
{
return !bdev_max_secure_erase_sectors(dev->bdev);
}
static bool dm_table_supports_secure_erase(struct dm_table *t)
{
for (unsigned int i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
if (!ti->num_secure_erase_bios)
return false;
if (!ti->type->iterate_devices ||
ti->type->iterate_devices(ti, device_not_secure_erase_capable, NULL))
return false;
}
return true;
}
static int device_requires_stable_pages(struct dm_target *ti,
struct dm_dev *dev, sector_t start,
sector_t len, void *data)
{
return bdev_stable_writes(dev->bdev);
}
int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
struct queue_limits *limits)
{
bool wc = false, fua = false;
int r;
/*
* Copy table's limits to the DM device's request_queue
*/
q->limits = *limits;
if (dm_table_supports_nowait(t))
blk_queue_flag_set(QUEUE_FLAG_NOWAIT, q);
else
blk_queue_flag_clear(QUEUE_FLAG_NOWAIT, q);
if (!dm_table_supports_discards(t)) {
q->limits.max_discard_sectors = 0;
q->limits.max_hw_discard_sectors = 0;
q->limits.discard_granularity = 0;
q->limits.discard_alignment = 0;
q->limits.discard_misaligned = 0;
}
if (!dm_table_supports_secure_erase(t))
q->limits.max_secure_erase_sectors = 0;
if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_WC))) {
wc = true;
if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_FUA)))
fua = true;
}
blk_queue_write_cache(q, wc, fua);
if (dm_table_supports_dax(t, device_not_dax_capable)) {
blk_queue_flag_set(QUEUE_FLAG_DAX, q);
if (dm_table_supports_dax(t, device_not_dax_synchronous_capable))
set_dax_synchronous(t->md->dax_dev);
} else
blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled, NULL))
dax_write_cache(t->md->dax_dev, true);
/* Ensure that all underlying devices are non-rotational. */
if (dm_table_any_dev_attr(t, device_is_rotational, NULL))
blk_queue_flag_clear(QUEUE_FLAG_NONROT, q);
else
blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
if (!dm_table_supports_write_zeroes(t))
q->limits.max_write_zeroes_sectors = 0;
dm_table_verify_integrity(t);
/*
* Some devices don't use blk_integrity but still want stable pages
* because they do their own checksumming.
* If any underlying device requires stable pages, a table must require
* them as well. Only targets that support iterate_devices are considered:
* don't want error, zero, etc to require stable pages.
*/
if (dm_table_any_dev_attr(t, device_requires_stable_pages, NULL))
blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q);
else
blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, q);
/*
* Determine whether or not this queue's I/O timings contribute
* to the entropy pool, Only request-based targets use this.
* Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
* have it set.
*/
if (blk_queue_add_random(q) &&
dm_table_any_dev_attr(t, device_is_not_random, NULL))
blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
/*
* For a zoned target, setup the zones related queue attributes
* and resources necessary for zone append emulation if necessary.
*/
if (blk_queue_is_zoned(q)) {
r = dm_set_zones_restrictions(t, q);
if (r)
return r;
if (!static_key_enabled(&zoned_enabled.key))
static_branch_enable(&zoned_enabled);
}
dm_update_crypto_profile(q, t);
disk_update_readahead(t->md->disk);
/*
* Check for request-based device is left to
* dm_mq_init_request_queue()->blk_mq_init_allocated_queue().
*
* For bio-based device, only set QUEUE_FLAG_POLL when all
* underlying devices supporting polling.
*/
if (__table_type_bio_based(t->type)) {
if (dm_table_supports_poll(t))
blk_queue_flag_set(QUEUE_FLAG_POLL, q);
else
blk_queue_flag_clear(QUEUE_FLAG_POLL, q);
}
return 0;
}
struct list_head *dm_table_get_devices(struct dm_table *t)
{
return &t->devices;
}
blk_mode_t dm_table_get_mode(struct dm_table *t)
{
return t->mode;
}
EXPORT_SYMBOL(dm_table_get_mode);
enum suspend_mode {
PRESUSPEND,
PRESUSPEND_UNDO,
POSTSUSPEND,
};
static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
{
lockdep_assert_held(&t->md->suspend_lock);
for (unsigned int i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
switch (mode) {
case PRESUSPEND:
if (ti->type->presuspend)
ti->type->presuspend(ti);
break;
case PRESUSPEND_UNDO:
if (ti->type->presuspend_undo)
ti->type->presuspend_undo(ti);
break;
case POSTSUSPEND:
if (ti->type->postsuspend)
ti->type->postsuspend(ti);
break;
}
}
}
void dm_table_presuspend_targets(struct dm_table *t)
{
if (!t)
return;
suspend_targets(t, PRESUSPEND);
}
void dm_table_presuspend_undo_targets(struct dm_table *t)
{
if (!t)
return;
suspend_targets(t, PRESUSPEND_UNDO);
}
void dm_table_postsuspend_targets(struct dm_table *t)
{
if (!t)
return;
suspend_targets(t, POSTSUSPEND);
}
int dm_table_resume_targets(struct dm_table *t)
{
unsigned int i;
int r = 0;
lockdep_assert_held(&t->md->suspend_lock);
for (i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
if (!ti->type->preresume)
continue;
r = ti->type->preresume(ti);
if (r) {
DMERR("%s: %s: preresume failed, error = %d",
dm_device_name(t->md), ti->type->name, r);
return r;
}
}
for (i = 0; i < t->num_targets; i++) {
struct dm_target *ti = dm_table_get_target(t, i);
if (ti->type->resume)
ti->type->resume(ti);
}
return 0;
}
struct mapped_device *dm_table_get_md(struct dm_table *t)
{
return t->md;
}
EXPORT_SYMBOL(dm_table_get_md);
const char *dm_table_device_name(struct dm_table *t)
{
return dm_device_name(t->md);
}
EXPORT_SYMBOL_GPL(dm_table_device_name);
void dm_table_run_md_queue_async(struct dm_table *t)
{
if (!dm_table_request_based(t))
return;
if (t->md->queue)
blk_mq_run_hw_queues(t->md->queue, true);
}
EXPORT_SYMBOL(dm_table_run_md_queue_async);
| linux-master | drivers/md/dm-table.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2007-2009 NEC Corporation. All Rights Reserved.
*
* Module Author: Kiyoshi Ueda
*
* This file is released under the GPL.
*
* Throughput oriented path selector.
*/
#include "dm.h"
#include "dm-path-selector.h"
#include <linux/slab.h>
#include <linux/module.h>
#define DM_MSG_PREFIX "multipath service-time"
#define ST_MIN_IO 1
#define ST_MAX_RELATIVE_THROUGHPUT 100
#define ST_MAX_RELATIVE_THROUGHPUT_SHIFT 7
#define ST_MAX_INFLIGHT_SIZE ((size_t)-1 >> ST_MAX_RELATIVE_THROUGHPUT_SHIFT)
#define ST_VERSION "0.3.0"
struct selector {
struct list_head valid_paths;
struct list_head failed_paths;
spinlock_t lock;
};
struct path_info {
struct list_head list;
struct dm_path *path;
unsigned int repeat_count;
unsigned int relative_throughput;
atomic_t in_flight_size; /* Total size of in-flight I/Os */
};
static struct selector *alloc_selector(void)
{
struct selector *s = kmalloc(sizeof(*s), GFP_KERNEL);
if (s) {
INIT_LIST_HEAD(&s->valid_paths);
INIT_LIST_HEAD(&s->failed_paths);
spin_lock_init(&s->lock);
}
return s;
}
static int st_create(struct path_selector *ps, unsigned int argc, char **argv)
{
struct selector *s = alloc_selector();
if (!s)
return -ENOMEM;
ps->context = s;
return 0;
}
static void free_paths(struct list_head *paths)
{
struct path_info *pi, *next;
list_for_each_entry_safe(pi, next, paths, list) {
list_del(&pi->list);
kfree(pi);
}
}
static void st_destroy(struct path_selector *ps)
{
struct selector *s = ps->context;
free_paths(&s->valid_paths);
free_paths(&s->failed_paths);
kfree(s);
ps->context = NULL;
}
static int st_status(struct path_selector *ps, struct dm_path *path,
status_type_t type, char *result, unsigned int maxlen)
{
unsigned int sz = 0;
struct path_info *pi;
if (!path)
DMEMIT("0 ");
else {
pi = path->pscontext;
switch (type) {
case STATUSTYPE_INFO:
DMEMIT("%d %u ", atomic_read(&pi->in_flight_size),
pi->relative_throughput);
break;
case STATUSTYPE_TABLE:
DMEMIT("%u %u ", pi->repeat_count,
pi->relative_throughput);
break;
case STATUSTYPE_IMA:
result[0] = '\0';
break;
}
}
return sz;
}
static int st_add_path(struct path_selector *ps, struct dm_path *path,
int argc, char **argv, char **error)
{
struct selector *s = ps->context;
struct path_info *pi;
unsigned int repeat_count = ST_MIN_IO;
unsigned int relative_throughput = 1;
char dummy;
unsigned long flags;
/*
* Arguments: [<repeat_count> [<relative_throughput>]]
* <repeat_count>: The number of I/Os before switching path.
* If not given, default (ST_MIN_IO) is used.
* <relative_throughput>: The relative throughput value of
* the path among all paths in the path-group.
* The valid range: 0-<ST_MAX_RELATIVE_THROUGHPUT>
* If not given, minimum value '1' is used.
* If '0' is given, the path isn't selected while
* other paths having a positive value are available.
*/
if (argc > 2) {
*error = "service-time ps: incorrect number of arguments";
return -EINVAL;
}
if (argc && (sscanf(argv[0], "%u%c", &repeat_count, &dummy) != 1)) {
*error = "service-time ps: invalid repeat count";
return -EINVAL;
}
if (repeat_count > 1) {
DMWARN_LIMIT("repeat_count > 1 is deprecated, using 1 instead");
repeat_count = 1;
}
if ((argc == 2) &&
(sscanf(argv[1], "%u%c", &relative_throughput, &dummy) != 1 ||
relative_throughput > ST_MAX_RELATIVE_THROUGHPUT)) {
*error = "service-time ps: invalid relative_throughput value";
return -EINVAL;
}
/* allocate the path */
pi = kmalloc(sizeof(*pi), GFP_KERNEL);
if (!pi) {
*error = "service-time ps: Error allocating path context";
return -ENOMEM;
}
pi->path = path;
pi->repeat_count = repeat_count;
pi->relative_throughput = relative_throughput;
atomic_set(&pi->in_flight_size, 0);
path->pscontext = pi;
spin_lock_irqsave(&s->lock, flags);
list_add_tail(&pi->list, &s->valid_paths);
spin_unlock_irqrestore(&s->lock, flags);
return 0;
}
static void st_fail_path(struct path_selector *ps, struct dm_path *path)
{
struct selector *s = ps->context;
struct path_info *pi = path->pscontext;
unsigned long flags;
spin_lock_irqsave(&s->lock, flags);
list_move(&pi->list, &s->failed_paths);
spin_unlock_irqrestore(&s->lock, flags);
}
static int st_reinstate_path(struct path_selector *ps, struct dm_path *path)
{
struct selector *s = ps->context;
struct path_info *pi = path->pscontext;
unsigned long flags;
spin_lock_irqsave(&s->lock, flags);
list_move_tail(&pi->list, &s->valid_paths);
spin_unlock_irqrestore(&s->lock, flags);
return 0;
}
/*
* Compare the estimated service time of 2 paths, pi1 and pi2,
* for the incoming I/O.
*
* Returns:
* < 0 : pi1 is better
* 0 : no difference between pi1 and pi2
* > 0 : pi2 is better
*
* Description:
* Basically, the service time is estimated by:
* ('pi->in-flight-size' + 'incoming') / 'pi->relative_throughput'
* To reduce the calculation, some optimizations are made.
* (See comments inline)
*/
static int st_compare_load(struct path_info *pi1, struct path_info *pi2,
size_t incoming)
{
size_t sz1, sz2, st1, st2;
sz1 = atomic_read(&pi1->in_flight_size);
sz2 = atomic_read(&pi2->in_flight_size);
/*
* Case 1: Both have same throughput value. Choose less loaded path.
*/
if (pi1->relative_throughput == pi2->relative_throughput)
return sz1 - sz2;
/*
* Case 2a: Both have same load. Choose higher throughput path.
* Case 2b: One path has no throughput value. Choose the other one.
*/
if (sz1 == sz2 ||
!pi1->relative_throughput || !pi2->relative_throughput)
return pi2->relative_throughput - pi1->relative_throughput;
/*
* Case 3: Calculate service time. Choose faster path.
* Service time using pi1:
* st1 = (sz1 + incoming) / pi1->relative_throughput
* Service time using pi2:
* st2 = (sz2 + incoming) / pi2->relative_throughput
*
* To avoid the division, transform the expression to use
* multiplication.
* Because ->relative_throughput > 0 here, if st1 < st2,
* the expressions below are the same meaning:
* (sz1 + incoming) / pi1->relative_throughput <
* (sz2 + incoming) / pi2->relative_throughput
* (sz1 + incoming) * pi2->relative_throughput <
* (sz2 + incoming) * pi1->relative_throughput
* So use the later one.
*/
sz1 += incoming;
sz2 += incoming;
if (unlikely(sz1 >= ST_MAX_INFLIGHT_SIZE ||
sz2 >= ST_MAX_INFLIGHT_SIZE)) {
/*
* Size may be too big for multiplying pi->relative_throughput
* and overflow.
* To avoid the overflow and mis-selection, shift down both.
*/
sz1 >>= ST_MAX_RELATIVE_THROUGHPUT_SHIFT;
sz2 >>= ST_MAX_RELATIVE_THROUGHPUT_SHIFT;
}
st1 = sz1 * pi2->relative_throughput;
st2 = sz2 * pi1->relative_throughput;
if (st1 != st2)
return st1 - st2;
/*
* Case 4: Service time is equal. Choose higher throughput path.
*/
return pi2->relative_throughput - pi1->relative_throughput;
}
static struct dm_path *st_select_path(struct path_selector *ps, size_t nr_bytes)
{
struct selector *s = ps->context;
struct path_info *pi = NULL, *best = NULL;
struct dm_path *ret = NULL;
unsigned long flags;
spin_lock_irqsave(&s->lock, flags);
if (list_empty(&s->valid_paths))
goto out;
list_for_each_entry(pi, &s->valid_paths, list)
if (!best || (st_compare_load(pi, best, nr_bytes) < 0))
best = pi;
if (!best)
goto out;
/* Move most recently used to least preferred to evenly balance. */
list_move_tail(&best->list, &s->valid_paths);
ret = best->path;
out:
spin_unlock_irqrestore(&s->lock, flags);
return ret;
}
static int st_start_io(struct path_selector *ps, struct dm_path *path,
size_t nr_bytes)
{
struct path_info *pi = path->pscontext;
atomic_add(nr_bytes, &pi->in_flight_size);
return 0;
}
static int st_end_io(struct path_selector *ps, struct dm_path *path,
size_t nr_bytes, u64 start_time)
{
struct path_info *pi = path->pscontext;
atomic_sub(nr_bytes, &pi->in_flight_size);
return 0;
}
static struct path_selector_type st_ps = {
.name = "service-time",
.module = THIS_MODULE,
.table_args = 2,
.info_args = 2,
.create = st_create,
.destroy = st_destroy,
.status = st_status,
.add_path = st_add_path,
.fail_path = st_fail_path,
.reinstate_path = st_reinstate_path,
.select_path = st_select_path,
.start_io = st_start_io,
.end_io = st_end_io,
};
static int __init dm_st_init(void)
{
int r = dm_register_path_selector(&st_ps);
if (r < 0)
DMERR("register failed %d", r);
DMINFO("version " ST_VERSION " loaded");
return r;
}
static void __exit dm_st_exit(void)
{
int r = dm_unregister_path_selector(&st_ps);
if (r < 0)
DMERR("unregister failed %d", r);
}
module_init(dm_st_init);
module_exit(dm_st_exit);
MODULE_DESCRIPTION(DM_NAME " throughput oriented path selector");
MODULE_AUTHOR("Kiyoshi Ueda <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-ps-service-time.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2003 Sistina Software Limited.
* Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
#include <linux/dm-dirty-log.h>
#include <linux/dm-region-hash.h>
#include <linux/ctype.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include "dm.h"
#define DM_MSG_PREFIX "region hash"
/*
*------------------------------------------------------------------
* Region hash
*
* The mirror splits itself up into discrete regions. Each
* region can be in one of three states: clean, dirty,
* nosync. There is no need to put clean regions in the hash.
*
* In addition to being present in the hash table a region _may_
* be present on one of three lists.
*
* clean_regions: Regions on this list have no io pending to
* them, they are in sync, we are no longer interested in them,
* they are dull. dm_rh_update_states() will remove them from the
* hash table.
*
* quiesced_regions: These regions have been spun down, ready
* for recovery. rh_recovery_start() will remove regions from
* this list and hand them to kmirrord, which will schedule the
* recovery io with kcopyd.
*
* recovered_regions: Regions that kcopyd has successfully
* recovered. dm_rh_update_states() will now schedule any delayed
* io, up the recovery_count, and remove the region from the
* hash.
*
* There are 2 locks:
* A rw spin lock 'hash_lock' protects just the hash table,
* this is never held in write mode from interrupt context,
* which I believe means that we only have to disable irqs when
* doing a write lock.
*
* An ordinary spin lock 'region_lock' that protects the three
* lists in the region_hash, with the 'state', 'list' and
* 'delayed_bios' fields of the regions. This is used from irq
* context, so all other uses will have to suspend local irqs.
*------------------------------------------------------------------
*/
struct dm_region_hash {
uint32_t region_size;
unsigned int region_shift;
/* holds persistent region state */
struct dm_dirty_log *log;
/* hash table */
rwlock_t hash_lock;
unsigned int mask;
unsigned int nr_buckets;
unsigned int prime;
unsigned int shift;
struct list_head *buckets;
/*
* If there was a flush failure no regions can be marked clean.
*/
int flush_failure;
unsigned int max_recovery; /* Max # of regions to recover in parallel */
spinlock_t region_lock;
atomic_t recovery_in_flight;
struct list_head clean_regions;
struct list_head quiesced_regions;
struct list_head recovered_regions;
struct list_head failed_recovered_regions;
struct semaphore recovery_count;
mempool_t region_pool;
void *context;
sector_t target_begin;
/* Callback function to schedule bios writes */
void (*dispatch_bios)(void *context, struct bio_list *bios);
/* Callback function to wakeup callers worker thread. */
void (*wakeup_workers)(void *context);
/* Callback function to wakeup callers recovery waiters. */
void (*wakeup_all_recovery_waiters)(void *context);
};
struct dm_region {
struct dm_region_hash *rh; /* FIXME: can we get rid of this ? */
region_t key;
int state;
struct list_head hash_list;
struct list_head list;
atomic_t pending;
struct bio_list delayed_bios;
};
/*
* Conversion fns
*/
static region_t dm_rh_sector_to_region(struct dm_region_hash *rh, sector_t sector)
{
return sector >> rh->region_shift;
}
sector_t dm_rh_region_to_sector(struct dm_region_hash *rh, region_t region)
{
return region << rh->region_shift;
}
EXPORT_SYMBOL_GPL(dm_rh_region_to_sector);
region_t dm_rh_bio_to_region(struct dm_region_hash *rh, struct bio *bio)
{
return dm_rh_sector_to_region(rh, bio->bi_iter.bi_sector -
rh->target_begin);
}
EXPORT_SYMBOL_GPL(dm_rh_bio_to_region);
void *dm_rh_region_context(struct dm_region *reg)
{
return reg->rh->context;
}
EXPORT_SYMBOL_GPL(dm_rh_region_context);
region_t dm_rh_get_region_key(struct dm_region *reg)
{
return reg->key;
}
EXPORT_SYMBOL_GPL(dm_rh_get_region_key);
sector_t dm_rh_get_region_size(struct dm_region_hash *rh)
{
return rh->region_size;
}
EXPORT_SYMBOL_GPL(dm_rh_get_region_size);
/*
* FIXME: shall we pass in a structure instead of all these args to
* dm_region_hash_create()????
*/
#define RH_HASH_MULT 2654435387U
#define RH_HASH_SHIFT 12
#define MIN_REGIONS 64
struct dm_region_hash *dm_region_hash_create(
void *context, void (*dispatch_bios)(void *context,
struct bio_list *bios),
void (*wakeup_workers)(void *context),
void (*wakeup_all_recovery_waiters)(void *context),
sector_t target_begin, unsigned int max_recovery,
struct dm_dirty_log *log, uint32_t region_size,
region_t nr_regions)
{
struct dm_region_hash *rh;
unsigned int nr_buckets, max_buckets;
size_t i;
int ret;
/*
* Calculate a suitable number of buckets for our hash
* table.
*/
max_buckets = nr_regions >> 6;
for (nr_buckets = 128u; nr_buckets < max_buckets; nr_buckets <<= 1)
;
nr_buckets >>= 1;
rh = kzalloc(sizeof(*rh), GFP_KERNEL);
if (!rh) {
DMERR("unable to allocate region hash memory");
return ERR_PTR(-ENOMEM);
}
rh->context = context;
rh->dispatch_bios = dispatch_bios;
rh->wakeup_workers = wakeup_workers;
rh->wakeup_all_recovery_waiters = wakeup_all_recovery_waiters;
rh->target_begin = target_begin;
rh->max_recovery = max_recovery;
rh->log = log;
rh->region_size = region_size;
rh->region_shift = __ffs(region_size);
rwlock_init(&rh->hash_lock);
rh->mask = nr_buckets - 1;
rh->nr_buckets = nr_buckets;
rh->shift = RH_HASH_SHIFT;
rh->prime = RH_HASH_MULT;
rh->buckets = vmalloc(array_size(nr_buckets, sizeof(*rh->buckets)));
if (!rh->buckets) {
DMERR("unable to allocate region hash bucket memory");
kfree(rh);
return ERR_PTR(-ENOMEM);
}
for (i = 0; i < nr_buckets; i++)
INIT_LIST_HEAD(rh->buckets + i);
spin_lock_init(&rh->region_lock);
sema_init(&rh->recovery_count, 0);
atomic_set(&rh->recovery_in_flight, 0);
INIT_LIST_HEAD(&rh->clean_regions);
INIT_LIST_HEAD(&rh->quiesced_regions);
INIT_LIST_HEAD(&rh->recovered_regions);
INIT_LIST_HEAD(&rh->failed_recovered_regions);
rh->flush_failure = 0;
ret = mempool_init_kmalloc_pool(&rh->region_pool, MIN_REGIONS,
sizeof(struct dm_region));
if (ret) {
vfree(rh->buckets);
kfree(rh);
rh = ERR_PTR(-ENOMEM);
}
return rh;
}
EXPORT_SYMBOL_GPL(dm_region_hash_create);
void dm_region_hash_destroy(struct dm_region_hash *rh)
{
unsigned int h;
struct dm_region *reg, *nreg;
BUG_ON(!list_empty(&rh->quiesced_regions));
for (h = 0; h < rh->nr_buckets; h++) {
list_for_each_entry_safe(reg, nreg, rh->buckets + h,
hash_list) {
BUG_ON(atomic_read(®->pending));
mempool_free(reg, &rh->region_pool);
}
}
if (rh->log)
dm_dirty_log_destroy(rh->log);
mempool_exit(&rh->region_pool);
vfree(rh->buckets);
kfree(rh);
}
EXPORT_SYMBOL_GPL(dm_region_hash_destroy);
struct dm_dirty_log *dm_rh_dirty_log(struct dm_region_hash *rh)
{
return rh->log;
}
EXPORT_SYMBOL_GPL(dm_rh_dirty_log);
static unsigned int rh_hash(struct dm_region_hash *rh, region_t region)
{
return (unsigned int) ((region * rh->prime) >> rh->shift) & rh->mask;
}
static struct dm_region *__rh_lookup(struct dm_region_hash *rh, region_t region)
{
struct dm_region *reg;
struct list_head *bucket = rh->buckets + rh_hash(rh, region);
list_for_each_entry(reg, bucket, hash_list)
if (reg->key == region)
return reg;
return NULL;
}
static void __rh_insert(struct dm_region_hash *rh, struct dm_region *reg)
{
list_add(®->hash_list, rh->buckets + rh_hash(rh, reg->key));
}
static struct dm_region *__rh_alloc(struct dm_region_hash *rh, region_t region)
{
struct dm_region *reg, *nreg;
nreg = mempool_alloc(&rh->region_pool, GFP_ATOMIC);
if (unlikely(!nreg))
nreg = kmalloc(sizeof(*nreg), GFP_NOIO | __GFP_NOFAIL);
nreg->state = rh->log->type->in_sync(rh->log, region, 1) ?
DM_RH_CLEAN : DM_RH_NOSYNC;
nreg->rh = rh;
nreg->key = region;
INIT_LIST_HEAD(&nreg->list);
atomic_set(&nreg->pending, 0);
bio_list_init(&nreg->delayed_bios);
write_lock_irq(&rh->hash_lock);
reg = __rh_lookup(rh, region);
if (reg)
/* We lost the race. */
mempool_free(nreg, &rh->region_pool);
else {
__rh_insert(rh, nreg);
if (nreg->state == DM_RH_CLEAN) {
spin_lock(&rh->region_lock);
list_add(&nreg->list, &rh->clean_regions);
spin_unlock(&rh->region_lock);
}
reg = nreg;
}
write_unlock_irq(&rh->hash_lock);
return reg;
}
static struct dm_region *__rh_find(struct dm_region_hash *rh, region_t region)
{
struct dm_region *reg;
reg = __rh_lookup(rh, region);
if (!reg) {
read_unlock(&rh->hash_lock);
reg = __rh_alloc(rh, region);
read_lock(&rh->hash_lock);
}
return reg;
}
int dm_rh_get_state(struct dm_region_hash *rh, region_t region, int may_block)
{
int r;
struct dm_region *reg;
read_lock(&rh->hash_lock);
reg = __rh_lookup(rh, region);
read_unlock(&rh->hash_lock);
if (reg)
return reg->state;
/*
* The region wasn't in the hash, so we fall back to the
* dirty log.
*/
r = rh->log->type->in_sync(rh->log, region, may_block);
/*
* Any error from the dirty log (eg. -EWOULDBLOCK) gets
* taken as a DM_RH_NOSYNC
*/
return r == 1 ? DM_RH_CLEAN : DM_RH_NOSYNC;
}
EXPORT_SYMBOL_GPL(dm_rh_get_state);
static void complete_resync_work(struct dm_region *reg, int success)
{
struct dm_region_hash *rh = reg->rh;
rh->log->type->set_region_sync(rh->log, reg->key, success);
/*
* Dispatch the bios before we call 'wake_up_all'.
* This is important because if we are suspending,
* we want to know that recovery is complete and
* the work queue is flushed. If we wake_up_all
* before we dispatch_bios (queue bios and call wake()),
* then we risk suspending before the work queue
* has been properly flushed.
*/
rh->dispatch_bios(rh->context, ®->delayed_bios);
if (atomic_dec_and_test(&rh->recovery_in_flight))
rh->wakeup_all_recovery_waiters(rh->context);
up(&rh->recovery_count);
}
/* dm_rh_mark_nosync
* @ms
* @bio
*
* The bio was written on some mirror(s) but failed on other mirror(s).
* We can successfully endio the bio but should avoid the region being
* marked clean by setting the state DM_RH_NOSYNC.
*
* This function is _not_ safe in interrupt context!
*/
void dm_rh_mark_nosync(struct dm_region_hash *rh, struct bio *bio)
{
unsigned long flags;
struct dm_dirty_log *log = rh->log;
struct dm_region *reg;
region_t region = dm_rh_bio_to_region(rh, bio);
int recovering = 0;
if (bio->bi_opf & REQ_PREFLUSH) {
rh->flush_failure = 1;
return;
}
if (bio_op(bio) == REQ_OP_DISCARD)
return;
/* We must inform the log that the sync count has changed. */
log->type->set_region_sync(log, region, 0);
read_lock(&rh->hash_lock);
reg = __rh_find(rh, region);
read_unlock(&rh->hash_lock);
/* region hash entry should exist because write was in-flight */
BUG_ON(!reg);
BUG_ON(!list_empty(®->list));
spin_lock_irqsave(&rh->region_lock, flags);
/*
* Possible cases:
* 1) DM_RH_DIRTY
* 2) DM_RH_NOSYNC: was dirty, other preceding writes failed
* 3) DM_RH_RECOVERING: flushing pending writes
* Either case, the region should have not been connected to list.
*/
recovering = (reg->state == DM_RH_RECOVERING);
reg->state = DM_RH_NOSYNC;
BUG_ON(!list_empty(®->list));
spin_unlock_irqrestore(&rh->region_lock, flags);
if (recovering)
complete_resync_work(reg, 0);
}
EXPORT_SYMBOL_GPL(dm_rh_mark_nosync);
void dm_rh_update_states(struct dm_region_hash *rh, int errors_handled)
{
struct dm_region *reg, *next;
LIST_HEAD(clean);
LIST_HEAD(recovered);
LIST_HEAD(failed_recovered);
/*
* Quickly grab the lists.
*/
write_lock_irq(&rh->hash_lock);
spin_lock(&rh->region_lock);
if (!list_empty(&rh->clean_regions)) {
list_splice_init(&rh->clean_regions, &clean);
list_for_each_entry(reg, &clean, list)
list_del(®->hash_list);
}
if (!list_empty(&rh->recovered_regions)) {
list_splice_init(&rh->recovered_regions, &recovered);
list_for_each_entry(reg, &recovered, list)
list_del(®->hash_list);
}
if (!list_empty(&rh->failed_recovered_regions)) {
list_splice_init(&rh->failed_recovered_regions,
&failed_recovered);
list_for_each_entry(reg, &failed_recovered, list)
list_del(®->hash_list);
}
spin_unlock(&rh->region_lock);
write_unlock_irq(&rh->hash_lock);
/*
* All the regions on the recovered and clean lists have
* now been pulled out of the system, so no need to do
* any more locking.
*/
list_for_each_entry_safe(reg, next, &recovered, list) {
rh->log->type->clear_region(rh->log, reg->key);
complete_resync_work(reg, 1);
mempool_free(reg, &rh->region_pool);
}
list_for_each_entry_safe(reg, next, &failed_recovered, list) {
complete_resync_work(reg, errors_handled ? 0 : 1);
mempool_free(reg, &rh->region_pool);
}
list_for_each_entry_safe(reg, next, &clean, list) {
rh->log->type->clear_region(rh->log, reg->key);
mempool_free(reg, &rh->region_pool);
}
rh->log->type->flush(rh->log);
}
EXPORT_SYMBOL_GPL(dm_rh_update_states);
static void rh_inc(struct dm_region_hash *rh, region_t region)
{
struct dm_region *reg;
read_lock(&rh->hash_lock);
reg = __rh_find(rh, region);
spin_lock_irq(&rh->region_lock);
atomic_inc(®->pending);
if (reg->state == DM_RH_CLEAN) {
reg->state = DM_RH_DIRTY;
list_del_init(®->list); /* take off the clean list */
spin_unlock_irq(&rh->region_lock);
rh->log->type->mark_region(rh->log, reg->key);
} else
spin_unlock_irq(&rh->region_lock);
read_unlock(&rh->hash_lock);
}
void dm_rh_inc_pending(struct dm_region_hash *rh, struct bio_list *bios)
{
struct bio *bio;
for (bio = bios->head; bio; bio = bio->bi_next) {
if (bio->bi_opf & REQ_PREFLUSH || bio_op(bio) == REQ_OP_DISCARD)
continue;
rh_inc(rh, dm_rh_bio_to_region(rh, bio));
}
}
EXPORT_SYMBOL_GPL(dm_rh_inc_pending);
void dm_rh_dec(struct dm_region_hash *rh, region_t region)
{
unsigned long flags;
struct dm_region *reg;
int should_wake = 0;
read_lock(&rh->hash_lock);
reg = __rh_lookup(rh, region);
read_unlock(&rh->hash_lock);
spin_lock_irqsave(&rh->region_lock, flags);
if (atomic_dec_and_test(®->pending)) {
/*
* There is no pending I/O for this region.
* We can move the region to corresponding list for next action.
* At this point, the region is not yet connected to any list.
*
* If the state is DM_RH_NOSYNC, the region should be kept off
* from clean list.
* The hash entry for DM_RH_NOSYNC will remain in memory
* until the region is recovered or the map is reloaded.
*/
/* do nothing for DM_RH_NOSYNC */
if (unlikely(rh->flush_failure)) {
/*
* If a write flush failed some time ago, we
* don't know whether or not this write made it
* to the disk, so we must resync the device.
*/
reg->state = DM_RH_NOSYNC;
} else if (reg->state == DM_RH_RECOVERING) {
list_add_tail(®->list, &rh->quiesced_regions);
} else if (reg->state == DM_RH_DIRTY) {
reg->state = DM_RH_CLEAN;
list_add(®->list, &rh->clean_regions);
}
should_wake = 1;
}
spin_unlock_irqrestore(&rh->region_lock, flags);
if (should_wake)
rh->wakeup_workers(rh->context);
}
EXPORT_SYMBOL_GPL(dm_rh_dec);
/*
* Starts quiescing a region in preparation for recovery.
*/
static int __rh_recovery_prepare(struct dm_region_hash *rh)
{
int r;
region_t region;
struct dm_region *reg;
/*
* Ask the dirty log what's next.
*/
r = rh->log->type->get_resync_work(rh->log, ®ion);
if (r <= 0)
return r;
/*
* Get this region, and start it quiescing by setting the
* recovering flag.
*/
read_lock(&rh->hash_lock);
reg = __rh_find(rh, region);
read_unlock(&rh->hash_lock);
spin_lock_irq(&rh->region_lock);
reg->state = DM_RH_RECOVERING;
/* Already quiesced ? */
if (atomic_read(®->pending))
list_del_init(®->list);
else
list_move(®->list, &rh->quiesced_regions);
spin_unlock_irq(&rh->region_lock);
return 1;
}
void dm_rh_recovery_prepare(struct dm_region_hash *rh)
{
/* Extra reference to avoid race with dm_rh_stop_recovery */
atomic_inc(&rh->recovery_in_flight);
while (!down_trylock(&rh->recovery_count)) {
atomic_inc(&rh->recovery_in_flight);
if (__rh_recovery_prepare(rh) <= 0) {
atomic_dec(&rh->recovery_in_flight);
up(&rh->recovery_count);
break;
}
}
/* Drop the extra reference */
if (atomic_dec_and_test(&rh->recovery_in_flight))
rh->wakeup_all_recovery_waiters(rh->context);
}
EXPORT_SYMBOL_GPL(dm_rh_recovery_prepare);
/*
* Returns any quiesced regions.
*/
struct dm_region *dm_rh_recovery_start(struct dm_region_hash *rh)
{
struct dm_region *reg = NULL;
spin_lock_irq(&rh->region_lock);
if (!list_empty(&rh->quiesced_regions)) {
reg = list_entry(rh->quiesced_regions.next,
struct dm_region, list);
list_del_init(®->list); /* remove from the quiesced list */
}
spin_unlock_irq(&rh->region_lock);
return reg;
}
EXPORT_SYMBOL_GPL(dm_rh_recovery_start);
void dm_rh_recovery_end(struct dm_region *reg, int success)
{
struct dm_region_hash *rh = reg->rh;
spin_lock_irq(&rh->region_lock);
if (success)
list_add(®->list, ®->rh->recovered_regions);
else
list_add(®->list, ®->rh->failed_recovered_regions);
spin_unlock_irq(&rh->region_lock);
rh->wakeup_workers(rh->context);
}
EXPORT_SYMBOL_GPL(dm_rh_recovery_end);
/* Return recovery in flight count. */
int dm_rh_recovery_in_flight(struct dm_region_hash *rh)
{
return atomic_read(&rh->recovery_in_flight);
}
EXPORT_SYMBOL_GPL(dm_rh_recovery_in_flight);
int dm_rh_flush(struct dm_region_hash *rh)
{
return rh->log->type->flush(rh->log);
}
EXPORT_SYMBOL_GPL(dm_rh_flush);
void dm_rh_delay(struct dm_region_hash *rh, struct bio *bio)
{
struct dm_region *reg;
read_lock(&rh->hash_lock);
reg = __rh_find(rh, dm_rh_bio_to_region(rh, bio));
bio_list_add(®->delayed_bios, bio);
read_unlock(&rh->hash_lock);
}
EXPORT_SYMBOL_GPL(dm_rh_delay);
void dm_rh_stop_recovery(struct dm_region_hash *rh)
{
int i;
/* wait for any recovering regions */
for (i = 0; i < rh->max_recovery; i++)
down(&rh->recovery_count);
}
EXPORT_SYMBOL_GPL(dm_rh_stop_recovery);
void dm_rh_start_recovery(struct dm_region_hash *rh)
{
int i;
for (i = 0; i < rh->max_recovery; i++)
up(&rh->recovery_count);
rh->wakeup_workers(rh->context);
}
EXPORT_SYMBOL_GPL(dm_rh_start_recovery);
MODULE_DESCRIPTION(DM_NAME " region hash");
MODULE_AUTHOR("Joe Thornber/Heinz Mauelshagen <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/dm-region-hash.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2001-2002 Sistina Software (UK) Limited.
* Copyright (C) 2006-2008 Red Hat GmbH
*
* This file is released under the GPL.
*/
#include "dm-exception-store.h"
#include <linux/ctype.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/slab.h>
#define DM_MSG_PREFIX "snapshot exception stores"
static LIST_HEAD(_exception_store_types);
static DEFINE_SPINLOCK(_lock);
static struct dm_exception_store_type *__find_exception_store_type(const char *name)
{
struct dm_exception_store_type *type;
list_for_each_entry(type, &_exception_store_types, list)
if (!strcmp(name, type->name))
return type;
return NULL;
}
static struct dm_exception_store_type *_get_exception_store_type(const char *name)
{
struct dm_exception_store_type *type;
spin_lock(&_lock);
type = __find_exception_store_type(name);
if (type && !try_module_get(type->module))
type = NULL;
spin_unlock(&_lock);
return type;
}
/*
* get_type
* @type_name
*
* Attempt to retrieve the dm_exception_store_type by name. If not already
* available, attempt to load the appropriate module.
*
* Exstore modules are named "dm-exstore-" followed by the 'type_name'.
* Modules may contain multiple types.
* This function will first try the module "dm-exstore-<type_name>",
* then truncate 'type_name' on the last '-' and try again.
*
* For example, if type_name was "clustered-shared", it would search
* 'dm-exstore-clustered-shared' then 'dm-exstore-clustered'.
*
* 'dm-exception-store-<type_name>' is too long of a name in my
* opinion, which is why I've chosen to have the files
* containing exception store implementations be 'dm-exstore-<type_name>'.
* If you want your module to be autoloaded, you will follow this
* naming convention.
*
* Returns: dm_exception_store_type* on success, NULL on failure
*/
static struct dm_exception_store_type *get_type(const char *type_name)
{
char *p, *type_name_dup;
struct dm_exception_store_type *type;
type = _get_exception_store_type(type_name);
if (type)
return type;
type_name_dup = kstrdup(type_name, GFP_KERNEL);
if (!type_name_dup) {
DMERR("No memory left to attempt load for \"%s\"", type_name);
return NULL;
}
while (request_module("dm-exstore-%s", type_name_dup) ||
!(type = _get_exception_store_type(type_name))) {
p = strrchr(type_name_dup, '-');
if (!p)
break;
p[0] = '\0';
}
if (!type)
DMWARN("Module for exstore type \"%s\" not found.", type_name);
kfree(type_name_dup);
return type;
}
static void put_type(struct dm_exception_store_type *type)
{
spin_lock(&_lock);
module_put(type->module);
spin_unlock(&_lock);
}
int dm_exception_store_type_register(struct dm_exception_store_type *type)
{
int r = 0;
spin_lock(&_lock);
if (!__find_exception_store_type(type->name))
list_add(&type->list, &_exception_store_types);
else
r = -EEXIST;
spin_unlock(&_lock);
return r;
}
EXPORT_SYMBOL(dm_exception_store_type_register);
int dm_exception_store_type_unregister(struct dm_exception_store_type *type)
{
spin_lock(&_lock);
if (!__find_exception_store_type(type->name)) {
spin_unlock(&_lock);
return -EINVAL;
}
list_del(&type->list);
spin_unlock(&_lock);
return 0;
}
EXPORT_SYMBOL(dm_exception_store_type_unregister);
static int set_chunk_size(struct dm_exception_store *store,
const char *chunk_size_arg, char **error)
{
unsigned int chunk_size;
if (kstrtouint(chunk_size_arg, 10, &chunk_size)) {
*error = "Invalid chunk size";
return -EINVAL;
}
if (!chunk_size) {
store->chunk_size = store->chunk_mask = store->chunk_shift = 0;
return 0;
}
return dm_exception_store_set_chunk_size(store, chunk_size, error);
}
int dm_exception_store_set_chunk_size(struct dm_exception_store *store,
unsigned int chunk_size,
char **error)
{
/* Check chunk_size is a power of 2 */
if (!is_power_of_2(chunk_size)) {
*error = "Chunk size is not a power of 2";
return -EINVAL;
}
/* Validate the chunk size against the device block size */
if (chunk_size %
(bdev_logical_block_size(dm_snap_cow(store->snap)->bdev) >> 9) ||
chunk_size %
(bdev_logical_block_size(dm_snap_origin(store->snap)->bdev) >> 9)) {
*error = "Chunk size is not a multiple of device blocksize";
return -EINVAL;
}
if (chunk_size > INT_MAX >> SECTOR_SHIFT) {
*error = "Chunk size is too high";
return -EINVAL;
}
store->chunk_size = chunk_size;
store->chunk_mask = chunk_size - 1;
store->chunk_shift = __ffs(chunk_size);
return 0;
}
int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
struct dm_snapshot *snap,
unsigned int *args_used,
struct dm_exception_store **store)
{
int r = 0;
struct dm_exception_store_type *type = NULL;
struct dm_exception_store *tmp_store;
char persistent;
if (argc < 2) {
ti->error = "Insufficient exception store arguments";
return -EINVAL;
}
tmp_store = kzalloc(sizeof(*tmp_store), GFP_KERNEL);
if (!tmp_store) {
ti->error = "Exception store allocation failed";
return -ENOMEM;
}
persistent = toupper(*argv[0]);
if (persistent == 'P')
type = get_type("P");
else if (persistent == 'N')
type = get_type("N");
else {
ti->error = "Exception store type is not P or N";
r = -EINVAL;
goto bad_type;
}
if (!type) {
ti->error = "Exception store type not recognised";
r = -EINVAL;
goto bad_type;
}
tmp_store->type = type;
tmp_store->snap = snap;
r = set_chunk_size(tmp_store, argv[1], &ti->error);
if (r)
goto bad;
r = type->ctr(tmp_store, (strlen(argv[0]) > 1 ? &argv[0][1] : NULL));
if (r) {
ti->error = "Exception store type constructor failed";
goto bad;
}
*args_used = 2;
*store = tmp_store;
return 0;
bad:
put_type(type);
bad_type:
kfree(tmp_store);
return r;
}
EXPORT_SYMBOL(dm_exception_store_create);
void dm_exception_store_destroy(struct dm_exception_store *store)
{
store->type->dtr(store);
put_type(store->type);
kfree(store);
}
EXPORT_SYMBOL(dm_exception_store_destroy);
int dm_exception_store_init(void)
{
int r;
r = dm_transient_snapshot_init();
if (r) {
DMERR("Unable to register transient exception store type.");
goto transient_fail;
}
r = dm_persistent_snapshot_init();
if (r) {
DMERR("Unable to register persistent exception store type");
goto persistent_fail;
}
return 0;
persistent_fail:
dm_transient_snapshot_exit();
transient_fail:
return r;
}
void dm_exception_store_exit(void)
{
dm_persistent_snapshot_exit();
dm_transient_snapshot_exit();
}
| linux-master | drivers/md/dm-exception-store.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2011 Red Hat, Inc.
*
* This file is released under the GPL.
*/
#include "dm-btree.h"
#include "dm-btree-internal.h"
#include "dm-transaction-manager.h"
#include <linux/export.h>
#include <linux/device-mapper.h>
#define DM_MSG_PREFIX "btree"
/*
* Removing an entry from a btree
* ==============================
*
* A very important constraint for our btree is that no node, except the
* root, may have fewer than a certain number of entries.
* (MIN_ENTRIES <= nr_entries <= MAX_ENTRIES).
*
* Ensuring this is complicated by the way we want to only ever hold the
* locks on 2 nodes concurrently, and only change nodes in a top to bottom
* fashion.
*
* Each node may have a left or right sibling. When decending the spine,
* if a node contains only MIN_ENTRIES then we try and increase this to at
* least MIN_ENTRIES + 1. We do this in the following ways:
*
* [A] No siblings => this can only happen if the node is the root, in which
* case we copy the childs contents over the root.
*
* [B] No left sibling
* ==> rebalance(node, right sibling)
*
* [C] No right sibling
* ==> rebalance(left sibling, node)
*
* [D] Both siblings, total_entries(left, node, right) <= DEL_THRESHOLD
* ==> delete node adding it's contents to left and right
*
* [E] Both siblings, total_entries(left, node, right) > DEL_THRESHOLD
* ==> rebalance(left, node, right)
*
* After these operations it's possible that the our original node no
* longer contains the desired sub tree. For this reason this rebalancing
* is performed on the children of the current node. This also avoids
* having a special case for the root.
*
* Once this rebalancing has occurred we can then step into the child node
* for internal nodes. Or delete the entry for leaf nodes.
*/
/*
* Some little utilities for moving node data around.
*/
static void node_shift(struct btree_node *n, int shift)
{
uint32_t nr_entries = le32_to_cpu(n->header.nr_entries);
uint32_t value_size = le32_to_cpu(n->header.value_size);
if (shift < 0) {
shift = -shift;
BUG_ON(shift > nr_entries);
BUG_ON((void *) key_ptr(n, shift) >= value_ptr(n, shift));
memmove(key_ptr(n, 0),
key_ptr(n, shift),
(nr_entries - shift) * sizeof(__le64));
memmove(value_ptr(n, 0),
value_ptr(n, shift),
(nr_entries - shift) * value_size);
} else {
BUG_ON(nr_entries + shift > le32_to_cpu(n->header.max_entries));
memmove(key_ptr(n, shift),
key_ptr(n, 0),
nr_entries * sizeof(__le64));
memmove(value_ptr(n, shift),
value_ptr(n, 0),
nr_entries * value_size);
}
}
static int node_copy(struct btree_node *left, struct btree_node *right, int shift)
{
uint32_t nr_left = le32_to_cpu(left->header.nr_entries);
uint32_t value_size = le32_to_cpu(left->header.value_size);
if (value_size != le32_to_cpu(right->header.value_size)) {
DMERR("mismatched value size");
return -EILSEQ;
}
if (shift < 0) {
shift = -shift;
if (nr_left + shift > le32_to_cpu(left->header.max_entries)) {
DMERR("bad shift");
return -EINVAL;
}
memcpy(key_ptr(left, nr_left),
key_ptr(right, 0),
shift * sizeof(__le64));
memcpy(value_ptr(left, nr_left),
value_ptr(right, 0),
shift * value_size);
} else {
if (shift > le32_to_cpu(right->header.max_entries)) {
DMERR("bad shift");
return -EINVAL;
}
memcpy(key_ptr(right, 0),
key_ptr(left, nr_left - shift),
shift * sizeof(__le64));
memcpy(value_ptr(right, 0),
value_ptr(left, nr_left - shift),
shift * value_size);
}
return 0;
}
/*
* Delete a specific entry from a leaf node.
*/
static void delete_at(struct btree_node *n, unsigned int index)
{
unsigned int nr_entries = le32_to_cpu(n->header.nr_entries);
unsigned int nr_to_copy = nr_entries - (index + 1);
uint32_t value_size = le32_to_cpu(n->header.value_size);
BUG_ON(index >= nr_entries);
if (nr_to_copy) {
memmove(key_ptr(n, index),
key_ptr(n, index + 1),
nr_to_copy * sizeof(__le64));
memmove(value_ptr(n, index),
value_ptr(n, index + 1),
nr_to_copy * value_size);
}
n->header.nr_entries = cpu_to_le32(nr_entries - 1);
}
static unsigned int merge_threshold(struct btree_node *n)
{
return le32_to_cpu(n->header.max_entries) / 3;
}
struct child {
unsigned int index;
struct dm_block *block;
struct btree_node *n;
};
static int init_child(struct dm_btree_info *info, struct dm_btree_value_type *vt,
struct btree_node *parent,
unsigned int index, struct child *result)
{
int r, inc;
dm_block_t root;
result->index = index;
root = value64(parent, index);
r = dm_tm_shadow_block(info->tm, root, &btree_node_validator,
&result->block, &inc);
if (r)
return r;
result->n = dm_block_data(result->block);
if (inc)
inc_children(info->tm, result->n, vt);
*((__le64 *) value_ptr(parent, index)) =
cpu_to_le64(dm_block_location(result->block));
return 0;
}
static void exit_child(struct dm_btree_info *info, struct child *c)
{
dm_tm_unlock(info->tm, c->block);
}
static int shift(struct btree_node *left, struct btree_node *right, int count)
{
int r;
uint32_t nr_left = le32_to_cpu(left->header.nr_entries);
uint32_t nr_right = le32_to_cpu(right->header.nr_entries);
uint32_t max_entries = le32_to_cpu(left->header.max_entries);
uint32_t r_max_entries = le32_to_cpu(right->header.max_entries);
if (max_entries != r_max_entries) {
DMERR("node max_entries mismatch");
return -EILSEQ;
}
if (nr_left - count > max_entries) {
DMERR("node shift out of bounds");
return -EINVAL;
}
if (nr_right + count > max_entries) {
DMERR("node shift out of bounds");
return -EINVAL;
}
if (!count)
return 0;
if (count > 0) {
node_shift(right, count);
r = node_copy(left, right, count);
if (r)
return r;
} else {
r = node_copy(left, right, count);
if (r)
return r;
node_shift(right, count);
}
left->header.nr_entries = cpu_to_le32(nr_left - count);
right->header.nr_entries = cpu_to_le32(nr_right + count);
return 0;
}
static int __rebalance2(struct dm_btree_info *info, struct btree_node *parent,
struct child *l, struct child *r)
{
int ret;
struct btree_node *left = l->n;
struct btree_node *right = r->n;
uint32_t nr_left = le32_to_cpu(left->header.nr_entries);
uint32_t nr_right = le32_to_cpu(right->header.nr_entries);
/*
* Ensure the number of entries in each child will be greater
* than or equal to (max_entries / 3 + 1), so no matter which
* child is used for removal, the number will still be not
* less than (max_entries / 3).
*/
unsigned int threshold = 2 * (merge_threshold(left) + 1);
if (nr_left + nr_right < threshold) {
/*
* Merge
*/
node_copy(left, right, -nr_right);
left->header.nr_entries = cpu_to_le32(nr_left + nr_right);
delete_at(parent, r->index);
/*
* We need to decrement the right block, but not it's
* children, since they're still referenced by left.
*/
dm_tm_dec(info->tm, dm_block_location(r->block));
} else {
/*
* Rebalance.
*/
unsigned int target_left = (nr_left + nr_right) / 2;
ret = shift(left, right, nr_left - target_left);
if (ret)
return ret;
*key_ptr(parent, r->index) = right->keys[0];
}
return 0;
}
static int rebalance2(struct shadow_spine *s, struct dm_btree_info *info,
struct dm_btree_value_type *vt, unsigned int left_index)
{
int r;
struct btree_node *parent;
struct child left, right;
parent = dm_block_data(shadow_current(s));
r = init_child(info, vt, parent, left_index, &left);
if (r)
return r;
r = init_child(info, vt, parent, left_index + 1, &right);
if (r) {
exit_child(info, &left);
return r;
}
r = __rebalance2(info, parent, &left, &right);
exit_child(info, &left);
exit_child(info, &right);
return r;
}
/*
* We dump as many entries from center as possible into left, then the rest
* in right, then rebalance2. This wastes some cpu, but I want something
* simple atm.
*/
static int delete_center_node(struct dm_btree_info *info, struct btree_node *parent,
struct child *l, struct child *c, struct child *r,
struct btree_node *left, struct btree_node *center, struct btree_node *right,
uint32_t nr_left, uint32_t nr_center, uint32_t nr_right)
{
uint32_t max_entries = le32_to_cpu(left->header.max_entries);
unsigned int shift = min(max_entries - nr_left, nr_center);
if (nr_left + shift > max_entries) {
DMERR("node shift out of bounds");
return -EINVAL;
}
node_copy(left, center, -shift);
left->header.nr_entries = cpu_to_le32(nr_left + shift);
if (shift != nr_center) {
shift = nr_center - shift;
if ((nr_right + shift) > max_entries) {
DMERR("node shift out of bounds");
return -EINVAL;
}
node_shift(right, shift);
node_copy(center, right, shift);
right->header.nr_entries = cpu_to_le32(nr_right + shift);
}
*key_ptr(parent, r->index) = right->keys[0];
delete_at(parent, c->index);
r->index--;
dm_tm_dec(info->tm, dm_block_location(c->block));
return __rebalance2(info, parent, l, r);
}
/*
* Redistributes entries among 3 sibling nodes.
*/
static int redistribute3(struct dm_btree_info *info, struct btree_node *parent,
struct child *l, struct child *c, struct child *r,
struct btree_node *left, struct btree_node *center, struct btree_node *right,
uint32_t nr_left, uint32_t nr_center, uint32_t nr_right)
{
int s, ret;
uint32_t max_entries = le32_to_cpu(left->header.max_entries);
unsigned int total = nr_left + nr_center + nr_right;
unsigned int target_right = total / 3;
unsigned int remainder = (target_right * 3) != total;
unsigned int target_left = target_right + remainder;
BUG_ON(target_left > max_entries);
BUG_ON(target_right > max_entries);
if (nr_left < nr_right) {
s = nr_left - target_left;
if (s < 0 && nr_center < -s) {
/* not enough in central node */
ret = shift(left, center, -nr_center);
if (ret)
return ret;
s += nr_center;
ret = shift(left, right, s);
if (ret)
return ret;
nr_right += s;
} else {
ret = shift(left, center, s);
if (ret)
return ret;
}
ret = shift(center, right, target_right - nr_right);
if (ret)
return ret;
} else {
s = target_right - nr_right;
if (s > 0 && nr_center < s) {
/* not enough in central node */
ret = shift(center, right, nr_center);
if (ret)
return ret;
s -= nr_center;
ret = shift(left, right, s);
if (ret)
return ret;
nr_left -= s;
} else {
ret = shift(center, right, s);
if (ret)
return ret;
}
ret = shift(left, center, nr_left - target_left);
if (ret)
return ret;
}
*key_ptr(parent, c->index) = center->keys[0];
*key_ptr(parent, r->index) = right->keys[0];
return 0;
}
static int __rebalance3(struct dm_btree_info *info, struct btree_node *parent,
struct child *l, struct child *c, struct child *r)
{
struct btree_node *left = l->n;
struct btree_node *center = c->n;
struct btree_node *right = r->n;
uint32_t nr_left = le32_to_cpu(left->header.nr_entries);
uint32_t nr_center = le32_to_cpu(center->header.nr_entries);
uint32_t nr_right = le32_to_cpu(right->header.nr_entries);
unsigned int threshold = merge_threshold(left) * 4 + 1;
if ((left->header.max_entries != center->header.max_entries) ||
(center->header.max_entries != right->header.max_entries)) {
DMERR("bad btree metadata, max_entries differ");
return -EILSEQ;
}
if ((nr_left + nr_center + nr_right) < threshold) {
return delete_center_node(info, parent, l, c, r, left, center, right,
nr_left, nr_center, nr_right);
}
return redistribute3(info, parent, l, c, r, left, center, right,
nr_left, nr_center, nr_right);
}
static int rebalance3(struct shadow_spine *s, struct dm_btree_info *info,
struct dm_btree_value_type *vt, unsigned int left_index)
{
int r;
struct btree_node *parent = dm_block_data(shadow_current(s));
struct child left, center, right;
/*
* FIXME: fill out an array?
*/
r = init_child(info, vt, parent, left_index, &left);
if (r)
return r;
r = init_child(info, vt, parent, left_index + 1, ¢er);
if (r) {
exit_child(info, &left);
return r;
}
r = init_child(info, vt, parent, left_index + 2, &right);
if (r) {
exit_child(info, &left);
exit_child(info, ¢er);
return r;
}
r = __rebalance3(info, parent, &left, ¢er, &right);
exit_child(info, &left);
exit_child(info, ¢er);
exit_child(info, &right);
return r;
}
static int rebalance_children(struct shadow_spine *s,
struct dm_btree_info *info,
struct dm_btree_value_type *vt, uint64_t key)
{
int i, r, has_left_sibling, has_right_sibling;
struct btree_node *n;
n = dm_block_data(shadow_current(s));
if (le32_to_cpu(n->header.nr_entries) == 1) {
struct dm_block *child;
dm_block_t b = value64(n, 0);
r = dm_tm_read_lock(info->tm, b, &btree_node_validator, &child);
if (r)
return r;
memcpy(n, dm_block_data(child),
dm_bm_block_size(dm_tm_get_bm(info->tm)));
dm_tm_dec(info->tm, dm_block_location(child));
dm_tm_unlock(info->tm, child);
return 0;
}
i = lower_bound(n, key);
if (i < 0)
return -ENODATA;
has_left_sibling = i > 0;
has_right_sibling = i < (le32_to_cpu(n->header.nr_entries) - 1);
if (!has_left_sibling)
r = rebalance2(s, info, vt, i);
else if (!has_right_sibling)
r = rebalance2(s, info, vt, i - 1);
else
r = rebalance3(s, info, vt, i - 1);
return r;
}
static int do_leaf(struct btree_node *n, uint64_t key, unsigned int *index)
{
int i = lower_bound(n, key);
if ((i < 0) ||
(i >= le32_to_cpu(n->header.nr_entries)) ||
(le64_to_cpu(n->keys[i]) != key))
return -ENODATA;
*index = i;
return 0;
}
/*
* Prepares for removal from one level of the hierarchy. The caller must
* call delete_at() to remove the entry at index.
*/
static int remove_raw(struct shadow_spine *s, struct dm_btree_info *info,
struct dm_btree_value_type *vt, dm_block_t root,
uint64_t key, unsigned int *index)
{
int i = *index, r;
struct btree_node *n;
for (;;) {
r = shadow_step(s, root, vt);
if (r < 0)
break;
/*
* We have to patch up the parent node, ugly, but I don't
* see a way to do this automatically as part of the spine
* op.
*/
if (shadow_has_parent(s)) {
__le64 location = cpu_to_le64(dm_block_location(shadow_current(s)));
memcpy(value_ptr(dm_block_data(shadow_parent(s)), i),
&location, sizeof(__le64));
}
n = dm_block_data(shadow_current(s));
if (le32_to_cpu(n->header.flags) & LEAF_NODE)
return do_leaf(n, key, index);
r = rebalance_children(s, info, vt, key);
if (r)
break;
n = dm_block_data(shadow_current(s));
if (le32_to_cpu(n->header.flags) & LEAF_NODE)
return do_leaf(n, key, index);
i = lower_bound(n, key);
/*
* We know the key is present, or else
* rebalance_children would have returned
* -ENODATA
*/
root = value64(n, i);
}
return r;
}
int dm_btree_remove(struct dm_btree_info *info, dm_block_t root,
uint64_t *keys, dm_block_t *new_root)
{
unsigned int level, last_level = info->levels - 1;
int index = 0, r = 0;
struct shadow_spine spine;
struct btree_node *n;
struct dm_btree_value_type le64_vt;
init_le64_type(info->tm, &le64_vt);
init_shadow_spine(&spine, info);
for (level = 0; level < info->levels; level++) {
r = remove_raw(&spine, info,
(level == last_level ?
&info->value_type : &le64_vt),
root, keys[level], (unsigned int *)&index);
if (r < 0)
break;
n = dm_block_data(shadow_current(&spine));
if (level != last_level) {
root = value64(n, index);
continue;
}
BUG_ON(index < 0 || index >= le32_to_cpu(n->header.nr_entries));
if (info->value_type.dec)
info->value_type.dec(info->value_type.context,
value_ptr(n, index), 1);
delete_at(n, index);
}
if (!r)
*new_root = shadow_root(&spine);
exit_shadow_spine(&spine);
return r;
}
EXPORT_SYMBOL_GPL(dm_btree_remove);
/*----------------------------------------------------------------*/
static int remove_nearest(struct shadow_spine *s, struct dm_btree_info *info,
struct dm_btree_value_type *vt, dm_block_t root,
uint64_t key, int *index)
{
int i = *index, r;
struct btree_node *n;
for (;;) {
r = shadow_step(s, root, vt);
if (r < 0)
break;
/*
* We have to patch up the parent node, ugly, but I don't
* see a way to do this automatically as part of the spine
* op.
*/
if (shadow_has_parent(s)) {
__le64 location = cpu_to_le64(dm_block_location(shadow_current(s)));
memcpy(value_ptr(dm_block_data(shadow_parent(s)), i),
&location, sizeof(__le64));
}
n = dm_block_data(shadow_current(s));
if (le32_to_cpu(n->header.flags) & LEAF_NODE) {
*index = lower_bound(n, key);
return 0;
}
r = rebalance_children(s, info, vt, key);
if (r)
break;
n = dm_block_data(shadow_current(s));
if (le32_to_cpu(n->header.flags) & LEAF_NODE) {
*index = lower_bound(n, key);
return 0;
}
i = lower_bound(n, key);
/*
* We know the key is present, or else
* rebalance_children would have returned
* -ENODATA
*/
root = value64(n, i);
}
return r;
}
static int remove_one(struct dm_btree_info *info, dm_block_t root,
uint64_t *keys, uint64_t end_key,
dm_block_t *new_root, unsigned int *nr_removed)
{
unsigned int level, last_level = info->levels - 1;
int index = 0, r = 0;
struct shadow_spine spine;
struct btree_node *n;
struct dm_btree_value_type le64_vt;
uint64_t k;
init_le64_type(info->tm, &le64_vt);
init_shadow_spine(&spine, info);
for (level = 0; level < last_level; level++) {
r = remove_raw(&spine, info, &le64_vt,
root, keys[level], (unsigned int *) &index);
if (r < 0)
goto out;
n = dm_block_data(shadow_current(&spine));
root = value64(n, index);
}
r = remove_nearest(&spine, info, &info->value_type,
root, keys[last_level], &index);
if (r < 0)
goto out;
n = dm_block_data(shadow_current(&spine));
if (index < 0)
index = 0;
if (index >= le32_to_cpu(n->header.nr_entries)) {
r = -ENODATA;
goto out;
}
k = le64_to_cpu(n->keys[index]);
if (k >= keys[last_level] && k < end_key) {
if (info->value_type.dec)
info->value_type.dec(info->value_type.context,
value_ptr(n, index), 1);
delete_at(n, index);
keys[last_level] = k + 1ull;
} else
r = -ENODATA;
out:
*new_root = shadow_root(&spine);
exit_shadow_spine(&spine);
return r;
}
int dm_btree_remove_leaves(struct dm_btree_info *info, dm_block_t root,
uint64_t *first_key, uint64_t end_key,
dm_block_t *new_root, unsigned int *nr_removed)
{
int r;
*nr_removed = 0;
do {
r = remove_one(info, root, first_key, end_key, &root, nr_removed);
if (!r)
(*nr_removed)++;
} while (!r);
*new_root = root;
return r == -ENODATA ? 0 : r;
}
EXPORT_SYMBOL_GPL(dm_btree_remove_leaves);
| linux-master | drivers/md/persistent-data/dm-btree-remove.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2011 Red Hat, Inc.
*
* This file is released under the GPL.
*/
#include "dm-space-map.h"
#include "dm-space-map-common.h"
#include "dm-space-map-metadata.h"
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/device-mapper.h>
#include <linux/kernel.h>
#define DM_MSG_PREFIX "space map metadata"
/*----------------------------------------------------------------*/
/*
* An edge triggered threshold.
*/
struct threshold {
bool threshold_set;
bool value_set;
dm_block_t threshold;
dm_block_t current_value;
dm_sm_threshold_fn fn;
void *context;
};
static void threshold_init(struct threshold *t)
{
t->threshold_set = false;
t->value_set = false;
}
static void set_threshold(struct threshold *t, dm_block_t value,
dm_sm_threshold_fn fn, void *context)
{
t->threshold_set = true;
t->threshold = value;
t->fn = fn;
t->context = context;
}
static bool below_threshold(struct threshold *t, dm_block_t value)
{
return t->threshold_set && value <= t->threshold;
}
static bool threshold_already_triggered(struct threshold *t)
{
return t->value_set && below_threshold(t, t->current_value);
}
static void check_threshold(struct threshold *t, dm_block_t value)
{
if (below_threshold(t, value) &&
!threshold_already_triggered(t))
t->fn(t->context);
t->value_set = true;
t->current_value = value;
}
/*----------------------------------------------------------------*/
/*
* Space map interface.
*
* The low level disk format is written using the standard btree and
* transaction manager. This means that performing disk operations may
* cause us to recurse into the space map in order to allocate new blocks.
* For this reason we have a pool of pre-allocated blocks large enough to
* service any metadata_ll_disk operation.
*/
/*
* FIXME: we should calculate this based on the size of the device.
* Only the metadata space map needs this functionality.
*/
#define MAX_RECURSIVE_ALLOCATIONS 1024
enum block_op_type {
BOP_INC,
BOP_DEC
};
struct block_op {
enum block_op_type type;
dm_block_t b;
dm_block_t e;
};
struct bop_ring_buffer {
unsigned int begin;
unsigned int end;
struct block_op bops[MAX_RECURSIVE_ALLOCATIONS + 1];
};
static void brb_init(struct bop_ring_buffer *brb)
{
brb->begin = 0;
brb->end = 0;
}
static bool brb_empty(struct bop_ring_buffer *brb)
{
return brb->begin == brb->end;
}
static unsigned int brb_next(struct bop_ring_buffer *brb, unsigned int old)
{
unsigned int r = old + 1;
return r >= ARRAY_SIZE(brb->bops) ? 0 : r;
}
static int brb_push(struct bop_ring_buffer *brb,
enum block_op_type type, dm_block_t b, dm_block_t e)
{
struct block_op *bop;
unsigned int next = brb_next(brb, brb->end);
/*
* We don't allow the last bop to be filled, this way we can
* differentiate between full and empty.
*/
if (next == brb->begin)
return -ENOMEM;
bop = brb->bops + brb->end;
bop->type = type;
bop->b = b;
bop->e = e;
brb->end = next;
return 0;
}
static int brb_peek(struct bop_ring_buffer *brb, struct block_op *result)
{
struct block_op *bop;
if (brb_empty(brb))
return -ENODATA;
bop = brb->bops + brb->begin;
memcpy(result, bop, sizeof(*result));
return 0;
}
static int brb_pop(struct bop_ring_buffer *brb)
{
if (brb_empty(brb))
return -ENODATA;
brb->begin = brb_next(brb, brb->begin);
return 0;
}
/*----------------------------------------------------------------*/
struct sm_metadata {
struct dm_space_map sm;
struct ll_disk ll;
struct ll_disk old_ll;
dm_block_t begin;
unsigned int recursion_count;
unsigned int allocated_this_transaction;
struct bop_ring_buffer uncommitted;
struct threshold threshold;
};
static int add_bop(struct sm_metadata *smm, enum block_op_type type, dm_block_t b, dm_block_t e)
{
int r = brb_push(&smm->uncommitted, type, b, e);
if (r) {
DMERR("too many recursive allocations");
return -ENOMEM;
}
return 0;
}
static int commit_bop(struct sm_metadata *smm, struct block_op *op)
{
int r = 0;
int32_t nr_allocations;
switch (op->type) {
case BOP_INC:
r = sm_ll_inc(&smm->ll, op->b, op->e, &nr_allocations);
break;
case BOP_DEC:
r = sm_ll_dec(&smm->ll, op->b, op->e, &nr_allocations);
break;
}
return r;
}
static void in(struct sm_metadata *smm)
{
smm->recursion_count++;
}
static int apply_bops(struct sm_metadata *smm)
{
int r = 0;
while (!brb_empty(&smm->uncommitted)) {
struct block_op bop;
r = brb_peek(&smm->uncommitted, &bop);
if (r) {
DMERR("bug in bop ring buffer");
break;
}
r = commit_bop(smm, &bop);
if (r)
break;
brb_pop(&smm->uncommitted);
}
return r;
}
static int out(struct sm_metadata *smm)
{
int r = 0;
/*
* If we're not recursing then very bad things are happening.
*/
if (!smm->recursion_count) {
DMERR("lost track of recursion depth");
return -ENOMEM;
}
if (smm->recursion_count == 1)
r = apply_bops(smm);
smm->recursion_count--;
return r;
}
/*
* When using the out() function above, we often want to combine an error
* code for the operation run in the recursive context with that from
* out().
*/
static int combine_errors(int r1, int r2)
{
return r1 ? r1 : r2;
}
static int recursing(struct sm_metadata *smm)
{
return smm->recursion_count;
}
static void sm_metadata_destroy(struct dm_space_map *sm)
{
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
kfree(smm);
}
static int sm_metadata_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count)
{
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
*count = smm->ll.nr_blocks;
return 0;
}
static int sm_metadata_get_nr_free(struct dm_space_map *sm, dm_block_t *count)
{
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
*count = smm->old_ll.nr_blocks - smm->old_ll.nr_allocated -
smm->allocated_this_transaction;
return 0;
}
static int sm_metadata_get_count(struct dm_space_map *sm, dm_block_t b,
uint32_t *result)
{
int r;
unsigned int i;
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
unsigned int adjustment = 0;
/*
* We may have some uncommitted adjustments to add. This list
* should always be really short.
*/
for (i = smm->uncommitted.begin;
i != smm->uncommitted.end;
i = brb_next(&smm->uncommitted, i)) {
struct block_op *op = smm->uncommitted.bops + i;
if (b < op->b || b >= op->e)
continue;
switch (op->type) {
case BOP_INC:
adjustment++;
break;
case BOP_DEC:
adjustment--;
break;
}
}
r = sm_ll_lookup(&smm->ll, b, result);
if (r)
return r;
*result += adjustment;
return 0;
}
static int sm_metadata_count_is_more_than_one(struct dm_space_map *sm,
dm_block_t b, int *result)
{
int r, adjustment = 0;
unsigned int i;
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
uint32_t rc;
/*
* We may have some uncommitted adjustments to add. This list
* should always be really short.
*/
for (i = smm->uncommitted.begin;
i != smm->uncommitted.end;
i = brb_next(&smm->uncommitted, i)) {
struct block_op *op = smm->uncommitted.bops + i;
if (b < op->b || b >= op->e)
continue;
switch (op->type) {
case BOP_INC:
adjustment++;
break;
case BOP_DEC:
adjustment--;
break;
}
}
if (adjustment > 1) {
*result = 1;
return 0;
}
r = sm_ll_lookup_bitmap(&smm->ll, b, &rc);
if (r)
return r;
if (rc == 3)
/*
* We err on the side of caution, and always return true.
*/
*result = 1;
else
*result = rc + adjustment > 1;
return 0;
}
static int sm_metadata_set_count(struct dm_space_map *sm, dm_block_t b,
uint32_t count)
{
int r, r2;
int32_t nr_allocations;
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
if (smm->recursion_count) {
DMERR("cannot recurse set_count()");
return -EINVAL;
}
in(smm);
r = sm_ll_insert(&smm->ll, b, count, &nr_allocations);
r2 = out(smm);
return combine_errors(r, r2);
}
static int sm_metadata_inc_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e)
{
int r, r2 = 0;
int32_t nr_allocations;
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
if (recursing(smm)) {
r = add_bop(smm, BOP_INC, b, e);
if (r)
return r;
} else {
in(smm);
r = sm_ll_inc(&smm->ll, b, e, &nr_allocations);
r2 = out(smm);
}
return combine_errors(r, r2);
}
static int sm_metadata_dec_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e)
{
int r, r2 = 0;
int32_t nr_allocations;
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
if (recursing(smm))
r = add_bop(smm, BOP_DEC, b, e);
else {
in(smm);
r = sm_ll_dec(&smm->ll, b, e, &nr_allocations);
r2 = out(smm);
}
return combine_errors(r, r2);
}
static int sm_metadata_new_block_(struct dm_space_map *sm, dm_block_t *b)
{
int r, r2 = 0;
int32_t nr_allocations;
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
/*
* Any block we allocate has to be free in both the old and current ll.
*/
r = sm_ll_find_common_free_block(&smm->old_ll, &smm->ll, smm->begin, smm->ll.nr_blocks, b);
if (r == -ENOSPC) {
/*
* There's no free block between smm->begin and the end of the metadata device.
* We search before smm->begin in case something has been freed.
*/
r = sm_ll_find_common_free_block(&smm->old_ll, &smm->ll, 0, smm->begin, b);
}
if (r)
return r;
smm->begin = *b + 1;
if (recursing(smm))
r = add_bop(smm, BOP_INC, *b, *b + 1);
else {
in(smm);
r = sm_ll_inc(&smm->ll, *b, *b + 1, &nr_allocations);
r2 = out(smm);
}
if (!r)
smm->allocated_this_transaction++;
return combine_errors(r, r2);
}
static int sm_metadata_new_block(struct dm_space_map *sm, dm_block_t *b)
{
dm_block_t count;
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
int r = sm_metadata_new_block_(sm, b);
if (r) {
DMERR_LIMIT("unable to allocate new metadata block");
return r;
}
r = sm_metadata_get_nr_free(sm, &count);
if (r) {
DMERR_LIMIT("couldn't get free block count");
return r;
}
check_threshold(&smm->threshold, count);
return r;
}
static int sm_metadata_commit(struct dm_space_map *sm)
{
int r;
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
r = sm_ll_commit(&smm->ll);
if (r)
return r;
memcpy(&smm->old_ll, &smm->ll, sizeof(smm->old_ll));
smm->allocated_this_transaction = 0;
return 0;
}
static int sm_metadata_register_threshold_callback(struct dm_space_map *sm,
dm_block_t threshold,
dm_sm_threshold_fn fn,
void *context)
{
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
set_threshold(&smm->threshold, threshold, fn, context);
return 0;
}
static int sm_metadata_root_size(struct dm_space_map *sm, size_t *result)
{
*result = sizeof(struct disk_sm_root);
return 0;
}
static int sm_metadata_copy_root(struct dm_space_map *sm, void *where_le, size_t max)
{
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
struct disk_sm_root root_le;
root_le.nr_blocks = cpu_to_le64(smm->ll.nr_blocks);
root_le.nr_allocated = cpu_to_le64(smm->ll.nr_allocated);
root_le.bitmap_root = cpu_to_le64(smm->ll.bitmap_root);
root_le.ref_count_root = cpu_to_le64(smm->ll.ref_count_root);
if (max < sizeof(root_le))
return -ENOSPC;
memcpy(where_le, &root_le, sizeof(root_le));
return 0;
}
static int sm_metadata_extend(struct dm_space_map *sm, dm_block_t extra_blocks);
static const struct dm_space_map ops = {
.destroy = sm_metadata_destroy,
.extend = sm_metadata_extend,
.get_nr_blocks = sm_metadata_get_nr_blocks,
.get_nr_free = sm_metadata_get_nr_free,
.get_count = sm_metadata_get_count,
.count_is_more_than_one = sm_metadata_count_is_more_than_one,
.set_count = sm_metadata_set_count,
.inc_blocks = sm_metadata_inc_blocks,
.dec_blocks = sm_metadata_dec_blocks,
.new_block = sm_metadata_new_block,
.commit = sm_metadata_commit,
.root_size = sm_metadata_root_size,
.copy_root = sm_metadata_copy_root,
.register_threshold_callback = sm_metadata_register_threshold_callback
};
/*----------------------------------------------------------------*/
/*
* When a new space map is created that manages its own space. We use
* this tiny bootstrap allocator.
*/
static void sm_bootstrap_destroy(struct dm_space_map *sm)
{
}
static int sm_bootstrap_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
{
DMERR("bootstrap doesn't support extend");
return -EINVAL;
}
static int sm_bootstrap_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count)
{
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
*count = smm->ll.nr_blocks;
return 0;
}
static int sm_bootstrap_get_nr_free(struct dm_space_map *sm, dm_block_t *count)
{
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
*count = smm->ll.nr_blocks - smm->begin;
return 0;
}
static int sm_bootstrap_get_count(struct dm_space_map *sm, dm_block_t b,
uint32_t *result)
{
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
*result = (b < smm->begin) ? 1 : 0;
return 0;
}
static int sm_bootstrap_count_is_more_than_one(struct dm_space_map *sm,
dm_block_t b, int *result)
{
*result = 0;
return 0;
}
static int sm_bootstrap_set_count(struct dm_space_map *sm, dm_block_t b,
uint32_t count)
{
DMERR("bootstrap doesn't support set_count");
return -EINVAL;
}
static int sm_bootstrap_new_block(struct dm_space_map *sm, dm_block_t *b)
{
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
/*
* We know the entire device is unused.
*/
if (smm->begin == smm->ll.nr_blocks)
return -ENOSPC;
*b = smm->begin++;
return 0;
}
static int sm_bootstrap_inc_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e)
{
int r;
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
r = add_bop(smm, BOP_INC, b, e);
if (r)
return r;
return 0;
}
static int sm_bootstrap_dec_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e)
{
int r;
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
r = add_bop(smm, BOP_DEC, b, e);
if (r)
return r;
return 0;
}
static int sm_bootstrap_commit(struct dm_space_map *sm)
{
return 0;
}
static int sm_bootstrap_root_size(struct dm_space_map *sm, size_t *result)
{
DMERR("bootstrap doesn't support root_size");
return -EINVAL;
}
static int sm_bootstrap_copy_root(struct dm_space_map *sm, void *where,
size_t max)
{
DMERR("bootstrap doesn't support copy_root");
return -EINVAL;
}
static const struct dm_space_map bootstrap_ops = {
.destroy = sm_bootstrap_destroy,
.extend = sm_bootstrap_extend,
.get_nr_blocks = sm_bootstrap_get_nr_blocks,
.get_nr_free = sm_bootstrap_get_nr_free,
.get_count = sm_bootstrap_get_count,
.count_is_more_than_one = sm_bootstrap_count_is_more_than_one,
.set_count = sm_bootstrap_set_count,
.inc_blocks = sm_bootstrap_inc_blocks,
.dec_blocks = sm_bootstrap_dec_blocks,
.new_block = sm_bootstrap_new_block,
.commit = sm_bootstrap_commit,
.root_size = sm_bootstrap_root_size,
.copy_root = sm_bootstrap_copy_root,
.register_threshold_callback = NULL
};
/*----------------------------------------------------------------*/
static int sm_metadata_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
{
int r;
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
dm_block_t old_len = smm->ll.nr_blocks;
/*
* Flick into a mode where all blocks get allocated in the new area.
*/
smm->begin = old_len;
memcpy(sm, &bootstrap_ops, sizeof(*sm));
/*
* Extend.
*/
r = sm_ll_extend(&smm->ll, extra_blocks);
if (r)
goto out;
/*
* We repeatedly increment then commit until the commit doesn't
* allocate any new blocks.
*/
do {
r = add_bop(smm, BOP_INC, old_len, smm->begin);
if (r)
goto out;
old_len = smm->begin;
r = apply_bops(smm);
if (r) {
DMERR("%s: apply_bops failed", __func__);
goto out;
}
r = sm_ll_commit(&smm->ll);
if (r)
goto out;
} while (old_len != smm->begin);
out:
/*
* Switch back to normal behaviour.
*/
memcpy(sm, &ops, sizeof(*sm));
return r;
}
/*----------------------------------------------------------------*/
struct dm_space_map *dm_sm_metadata_init(void)
{
struct sm_metadata *smm;
smm = kmalloc(sizeof(*smm), GFP_KERNEL);
if (!smm)
return ERR_PTR(-ENOMEM);
memcpy(&smm->sm, &ops, sizeof(smm->sm));
return &smm->sm;
}
int dm_sm_metadata_create(struct dm_space_map *sm,
struct dm_transaction_manager *tm,
dm_block_t nr_blocks,
dm_block_t superblock)
{
int r;
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
smm->begin = superblock + 1;
smm->recursion_count = 0;
smm->allocated_this_transaction = 0;
brb_init(&smm->uncommitted);
threshold_init(&smm->threshold);
memcpy(&smm->sm, &bootstrap_ops, sizeof(smm->sm));
r = sm_ll_new_metadata(&smm->ll, tm);
if (!r) {
if (nr_blocks > DM_SM_METADATA_MAX_BLOCKS)
nr_blocks = DM_SM_METADATA_MAX_BLOCKS;
r = sm_ll_extend(&smm->ll, nr_blocks);
}
memcpy(&smm->sm, &ops, sizeof(smm->sm));
if (r)
return r;
/*
* Now we need to update the newly created data structures with the
* allocated blocks that they were built from.
*/
r = add_bop(smm, BOP_INC, superblock, smm->begin);
if (r)
return r;
r = apply_bops(smm);
if (r) {
DMERR("%s: apply_bops failed", __func__);
return r;
}
return sm_metadata_commit(sm);
}
int dm_sm_metadata_open(struct dm_space_map *sm,
struct dm_transaction_manager *tm,
void *root_le, size_t len)
{
int r;
struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
r = sm_ll_open_metadata(&smm->ll, tm, root_le, len);
if (r)
return r;
smm->begin = 0;
smm->recursion_count = 0;
smm->allocated_this_transaction = 0;
brb_init(&smm->uncommitted);
threshold_init(&smm->threshold);
memcpy(&smm->old_ll, &smm->ll, sizeof(smm->old_ll));
return 0;
}
| linux-master | drivers/md/persistent-data/dm-space-map-metadata.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2011 Red Hat, Inc.
*
* This file is released under the GPL.
*/
#include "dm-space-map-common.h"
#include "dm-transaction-manager.h"
#include "dm-btree-internal.h"
#include "dm-persistent-data-internal.h"
#include <linux/bitops.h>
#include <linux/device-mapper.h>
#define DM_MSG_PREFIX "space map common"
/*----------------------------------------------------------------*/
/*
* Index validator.
*/
#define INDEX_CSUM_XOR 160478
static void index_prepare_for_write(struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
struct disk_metadata_index *mi_le = dm_block_data(b);
mi_le->blocknr = cpu_to_le64(dm_block_location(b));
mi_le->csum = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
block_size - sizeof(__le32),
INDEX_CSUM_XOR));
}
static int index_check(struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
struct disk_metadata_index *mi_le = dm_block_data(b);
__le32 csum_disk;
if (dm_block_location(b) != le64_to_cpu(mi_le->blocknr)) {
DMERR_LIMIT("%s failed: blocknr %llu != wanted %llu", __func__,
le64_to_cpu(mi_le->blocknr), dm_block_location(b));
return -ENOTBLK;
}
csum_disk = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
block_size - sizeof(__le32),
INDEX_CSUM_XOR));
if (csum_disk != mi_le->csum) {
DMERR_LIMIT("i%s failed: csum %u != wanted %u", __func__,
le32_to_cpu(csum_disk), le32_to_cpu(mi_le->csum));
return -EILSEQ;
}
return 0;
}
static struct dm_block_validator index_validator = {
.name = "index",
.prepare_for_write = index_prepare_for_write,
.check = index_check
};
/*----------------------------------------------------------------*/
/*
* Bitmap validator
*/
#define BITMAP_CSUM_XOR 240779
static void dm_bitmap_prepare_for_write(struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
struct disk_bitmap_header *disk_header = dm_block_data(b);
disk_header->blocknr = cpu_to_le64(dm_block_location(b));
disk_header->csum = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
block_size - sizeof(__le32),
BITMAP_CSUM_XOR));
}
static int dm_bitmap_check(struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
struct disk_bitmap_header *disk_header = dm_block_data(b);
__le32 csum_disk;
if (dm_block_location(b) != le64_to_cpu(disk_header->blocknr)) {
DMERR_LIMIT("bitmap check failed: blocknr %llu != wanted %llu",
le64_to_cpu(disk_header->blocknr), dm_block_location(b));
return -ENOTBLK;
}
csum_disk = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
block_size - sizeof(__le32),
BITMAP_CSUM_XOR));
if (csum_disk != disk_header->csum) {
DMERR_LIMIT("bitmap check failed: csum %u != wanted %u",
le32_to_cpu(csum_disk), le32_to_cpu(disk_header->csum));
return -EILSEQ;
}
return 0;
}
static struct dm_block_validator dm_sm_bitmap_validator = {
.name = "sm_bitmap",
.prepare_for_write = dm_bitmap_prepare_for_write,
.check = dm_bitmap_check,
};
/*----------------------------------------------------------------*/
#define ENTRIES_PER_WORD 32
#define ENTRIES_SHIFT 5
static void *dm_bitmap_data(struct dm_block *b)
{
return dm_block_data(b) + sizeof(struct disk_bitmap_header);
}
#define WORD_MASK_HIGH 0xAAAAAAAAAAAAAAAAULL
static unsigned int dm_bitmap_word_used(void *addr, unsigned int b)
{
__le64 *words_le = addr;
__le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
uint64_t bits = le64_to_cpu(*w_le);
uint64_t mask = (bits + WORD_MASK_HIGH + 1) & WORD_MASK_HIGH;
return !(~bits & mask);
}
static unsigned int sm_lookup_bitmap(void *addr, unsigned int b)
{
__le64 *words_le = addr;
__le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
unsigned int hi, lo;
b = (b & (ENTRIES_PER_WORD - 1)) << 1;
hi = !!test_bit_le(b, (void *) w_le);
lo = !!test_bit_le(b + 1, (void *) w_le);
return (hi << 1) | lo;
}
static void sm_set_bitmap(void *addr, unsigned int b, unsigned int val)
{
__le64 *words_le = addr;
__le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
b = (b & (ENTRIES_PER_WORD - 1)) << 1;
if (val & 2)
__set_bit_le(b, (void *) w_le);
else
__clear_bit_le(b, (void *) w_le);
if (val & 1)
__set_bit_le(b + 1, (void *) w_le);
else
__clear_bit_le(b + 1, (void *) w_le);
}
static int sm_find_free(void *addr, unsigned int begin, unsigned int end,
unsigned int *result)
{
while (begin < end) {
if (!(begin & (ENTRIES_PER_WORD - 1)) &&
dm_bitmap_word_used(addr, begin)) {
begin += ENTRIES_PER_WORD;
continue;
}
if (!sm_lookup_bitmap(addr, begin)) {
*result = begin;
return 0;
}
begin++;
}
return -ENOSPC;
}
/*----------------------------------------------------------------*/
static int sm_ll_init(struct ll_disk *ll, struct dm_transaction_manager *tm)
{
memset(ll, 0, sizeof(struct ll_disk));
ll->tm = tm;
ll->bitmap_info.tm = tm;
ll->bitmap_info.levels = 1;
/*
* Because the new bitmap blocks are created via a shadow
* operation, the old entry has already had its reference count
* decremented and we don't need the btree to do any bookkeeping.
*/
ll->bitmap_info.value_type.size = sizeof(struct disk_index_entry);
ll->bitmap_info.value_type.inc = NULL;
ll->bitmap_info.value_type.dec = NULL;
ll->bitmap_info.value_type.equal = NULL;
ll->ref_count_info.tm = tm;
ll->ref_count_info.levels = 1;
ll->ref_count_info.value_type.size = sizeof(uint32_t);
ll->ref_count_info.value_type.inc = NULL;
ll->ref_count_info.value_type.dec = NULL;
ll->ref_count_info.value_type.equal = NULL;
ll->block_size = dm_bm_block_size(dm_tm_get_bm(tm));
if (ll->block_size > (1 << 30)) {
DMERR("block size too big to hold bitmaps");
return -EINVAL;
}
ll->entries_per_block = (ll->block_size - sizeof(struct disk_bitmap_header)) *
ENTRIES_PER_BYTE;
ll->nr_blocks = 0;
ll->bitmap_root = 0;
ll->ref_count_root = 0;
ll->bitmap_index_changed = false;
return 0;
}
int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks)
{
int r;
dm_block_t i, nr_blocks, nr_indexes;
unsigned int old_blocks, blocks;
nr_blocks = ll->nr_blocks + extra_blocks;
old_blocks = dm_sector_div_up(ll->nr_blocks, ll->entries_per_block);
blocks = dm_sector_div_up(nr_blocks, ll->entries_per_block);
nr_indexes = dm_sector_div_up(nr_blocks, ll->entries_per_block);
if (nr_indexes > ll->max_entries(ll)) {
DMERR("space map too large");
return -EINVAL;
}
/*
* We need to set this before the dm_tm_new_block() call below.
*/
ll->nr_blocks = nr_blocks;
for (i = old_blocks; i < blocks; i++) {
struct dm_block *b;
struct disk_index_entry idx;
r = dm_tm_new_block(ll->tm, &dm_sm_bitmap_validator, &b);
if (r < 0)
return r;
idx.blocknr = cpu_to_le64(dm_block_location(b));
dm_tm_unlock(ll->tm, b);
idx.nr_free = cpu_to_le32(ll->entries_per_block);
idx.none_free_before = 0;
r = ll->save_ie(ll, i, &idx);
if (r < 0)
return r;
}
return 0;
}
int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
{
int r;
dm_block_t index = b;
struct disk_index_entry ie_disk;
struct dm_block *blk;
if (b >= ll->nr_blocks) {
DMERR_LIMIT("metadata block out of bounds");
return -EINVAL;
}
b = do_div(index, ll->entries_per_block);
r = ll->load_ie(ll, index, &ie_disk);
if (r < 0)
return r;
r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
&dm_sm_bitmap_validator, &blk);
if (r < 0)
return r;
*result = sm_lookup_bitmap(dm_bitmap_data(blk), b);
dm_tm_unlock(ll->tm, blk);
return 0;
}
static int sm_ll_lookup_big_ref_count(struct ll_disk *ll, dm_block_t b,
uint32_t *result)
{
__le32 le_rc;
int r;
r = dm_btree_lookup(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc);
if (r < 0)
return r;
*result = le32_to_cpu(le_rc);
return r;
}
int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
{
int r = sm_ll_lookup_bitmap(ll, b, result);
if (r)
return r;
if (*result != 3)
return r;
return sm_ll_lookup_big_ref_count(ll, b, result);
}
int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
dm_block_t end, dm_block_t *result)
{
int r;
struct disk_index_entry ie_disk;
dm_block_t i, index_begin = begin;
dm_block_t index_end = dm_sector_div_up(end, ll->entries_per_block);
/*
* FIXME: Use shifts
*/
begin = do_div(index_begin, ll->entries_per_block);
end = do_div(end, ll->entries_per_block);
if (end == 0)
end = ll->entries_per_block;
for (i = index_begin; i < index_end; i++, begin = 0) {
struct dm_block *blk;
unsigned int position;
uint32_t bit_end;
r = ll->load_ie(ll, i, &ie_disk);
if (r < 0)
return r;
if (le32_to_cpu(ie_disk.nr_free) == 0)
continue;
r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
&dm_sm_bitmap_validator, &blk);
if (r < 0)
return r;
bit_end = (i == index_end - 1) ? end : ll->entries_per_block;
r = sm_find_free(dm_bitmap_data(blk),
max_t(unsigned int, begin, le32_to_cpu(ie_disk.none_free_before)),
bit_end, &position);
if (r == -ENOSPC) {
/*
* This might happen because we started searching
* part way through the bitmap.
*/
dm_tm_unlock(ll->tm, blk);
continue;
}
dm_tm_unlock(ll->tm, blk);
*result = i * ll->entries_per_block + (dm_block_t) position;
return 0;
}
return -ENOSPC;
}
int sm_ll_find_common_free_block(struct ll_disk *old_ll, struct ll_disk *new_ll,
dm_block_t begin, dm_block_t end, dm_block_t *b)
{
int r;
uint32_t count;
do {
r = sm_ll_find_free_block(new_ll, begin, new_ll->nr_blocks, b);
if (r)
break;
/* double check this block wasn't used in the old transaction */
if (*b >= old_ll->nr_blocks)
count = 0;
else {
r = sm_ll_lookup(old_ll, *b, &count);
if (r)
break;
if (count)
begin = *b + 1;
}
} while (count);
return r;
}
/*----------------------------------------------------------------*/
int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
uint32_t ref_count, int32_t *nr_allocations)
{
int r;
uint32_t bit, old;
struct dm_block *nb;
dm_block_t index = b;
struct disk_index_entry ie_disk;
void *bm_le;
int inc;
bit = do_div(index, ll->entries_per_block);
r = ll->load_ie(ll, index, &ie_disk);
if (r < 0)
return r;
r = dm_tm_shadow_block(ll->tm, le64_to_cpu(ie_disk.blocknr),
&dm_sm_bitmap_validator, &nb, &inc);
if (r < 0) {
DMERR("dm_tm_shadow_block() failed");
return r;
}
ie_disk.blocknr = cpu_to_le64(dm_block_location(nb));
bm_le = dm_bitmap_data(nb);
old = sm_lookup_bitmap(bm_le, bit);
if (old > 2) {
r = sm_ll_lookup_big_ref_count(ll, b, &old);
if (r < 0) {
dm_tm_unlock(ll->tm, nb);
return r;
}
}
if (r) {
dm_tm_unlock(ll->tm, nb);
return r;
}
if (ref_count <= 2) {
sm_set_bitmap(bm_le, bit, ref_count);
dm_tm_unlock(ll->tm, nb);
if (old > 2) {
r = dm_btree_remove(&ll->ref_count_info,
ll->ref_count_root,
&b, &ll->ref_count_root);
if (r)
return r;
}
} else {
__le32 le_rc = cpu_to_le32(ref_count);
sm_set_bitmap(bm_le, bit, 3);
dm_tm_unlock(ll->tm, nb);
__dm_bless_for_disk(&le_rc);
r = dm_btree_insert(&ll->ref_count_info, ll->ref_count_root,
&b, &le_rc, &ll->ref_count_root);
if (r < 0) {
DMERR("ref count insert failed");
return r;
}
}
if (ref_count && !old) {
*nr_allocations = 1;
ll->nr_allocated++;
le32_add_cpu(&ie_disk.nr_free, -1);
if (le32_to_cpu(ie_disk.none_free_before) == bit)
ie_disk.none_free_before = cpu_to_le32(bit + 1);
} else if (old && !ref_count) {
*nr_allocations = -1;
ll->nr_allocated--;
le32_add_cpu(&ie_disk.nr_free, 1);
ie_disk.none_free_before = cpu_to_le32(min(le32_to_cpu(ie_disk.none_free_before), bit));
} else
*nr_allocations = 0;
return ll->save_ie(ll, index, &ie_disk);
}
/*----------------------------------------------------------------*/
/*
* Holds useful intermediate results for the range based inc and dec
* operations.
*/
struct inc_context {
struct disk_index_entry ie_disk;
struct dm_block *bitmap_block;
void *bitmap;
struct dm_block *overflow_leaf;
};
static inline void init_inc_context(struct inc_context *ic)
{
ic->bitmap_block = NULL;
ic->bitmap = NULL;
ic->overflow_leaf = NULL;
}
static inline void exit_inc_context(struct ll_disk *ll, struct inc_context *ic)
{
if (ic->bitmap_block)
dm_tm_unlock(ll->tm, ic->bitmap_block);
if (ic->overflow_leaf)
dm_tm_unlock(ll->tm, ic->overflow_leaf);
}
static inline void reset_inc_context(struct ll_disk *ll, struct inc_context *ic)
{
exit_inc_context(ll, ic);
init_inc_context(ic);
}
/*
* Confirms a btree node contains a particular key at an index.
*/
static bool contains_key(struct btree_node *n, uint64_t key, int index)
{
return index >= 0 &&
index < le32_to_cpu(n->header.nr_entries) &&
le64_to_cpu(n->keys[index]) == key;
}
static int __sm_ll_inc_overflow(struct ll_disk *ll, dm_block_t b, struct inc_context *ic)
{
int r;
int index;
struct btree_node *n;
__le32 *v_ptr;
uint32_t rc;
/*
* bitmap_block needs to be unlocked because getting the
* overflow_leaf may need to allocate, and thus use the space map.
*/
reset_inc_context(ll, ic);
r = btree_get_overwrite_leaf(&ll->ref_count_info, ll->ref_count_root,
b, &index, &ll->ref_count_root, &ic->overflow_leaf);
if (r < 0)
return r;
n = dm_block_data(ic->overflow_leaf);
if (!contains_key(n, b, index)) {
DMERR("overflow btree is missing an entry");
return -EINVAL;
}
v_ptr = value_ptr(n, index);
rc = le32_to_cpu(*v_ptr) + 1;
*v_ptr = cpu_to_le32(rc);
return 0;
}
static int sm_ll_inc_overflow(struct ll_disk *ll, dm_block_t b, struct inc_context *ic)
{
int index;
struct btree_node *n;
__le32 *v_ptr;
uint32_t rc;
/*
* Do we already have the correct overflow leaf?
*/
if (ic->overflow_leaf) {
n = dm_block_data(ic->overflow_leaf);
index = lower_bound(n, b);
if (contains_key(n, b, index)) {
v_ptr = value_ptr(n, index);
rc = le32_to_cpu(*v_ptr) + 1;
*v_ptr = cpu_to_le32(rc);
return 0;
}
}
return __sm_ll_inc_overflow(ll, b, ic);
}
static inline int shadow_bitmap(struct ll_disk *ll, struct inc_context *ic)
{
int r, inc;
r = dm_tm_shadow_block(ll->tm, le64_to_cpu(ic->ie_disk.blocknr),
&dm_sm_bitmap_validator, &ic->bitmap_block, &inc);
if (r < 0) {
DMERR("dm_tm_shadow_block() failed");
return r;
}
ic->ie_disk.blocknr = cpu_to_le64(dm_block_location(ic->bitmap_block));
ic->bitmap = dm_bitmap_data(ic->bitmap_block);
return 0;
}
/*
* Once shadow_bitmap has been called, which always happens at the start of inc/dec,
* we can reopen the bitmap with a simple write lock, rather than re calling
* dm_tm_shadow_block().
*/
static inline int ensure_bitmap(struct ll_disk *ll, struct inc_context *ic)
{
if (!ic->bitmap_block) {
int r = dm_bm_write_lock(dm_tm_get_bm(ll->tm), le64_to_cpu(ic->ie_disk.blocknr),
&dm_sm_bitmap_validator, &ic->bitmap_block);
if (r) {
DMERR("unable to re-get write lock for bitmap");
return r;
}
ic->bitmap = dm_bitmap_data(ic->bitmap_block);
}
return 0;
}
/*
* Loops round incrementing entries in a single bitmap.
*/
static inline int sm_ll_inc_bitmap(struct ll_disk *ll, dm_block_t b,
uint32_t bit, uint32_t bit_end,
int32_t *nr_allocations, dm_block_t *new_b,
struct inc_context *ic)
{
int r;
__le32 le_rc;
uint32_t old;
for (; bit != bit_end; bit++, b++) {
/*
* We only need to drop the bitmap if we need to find a new btree
* leaf for the overflow. So if it was dropped last iteration,
* we now re-get it.
*/
r = ensure_bitmap(ll, ic);
if (r)
return r;
old = sm_lookup_bitmap(ic->bitmap, bit);
switch (old) {
case 0:
/* inc bitmap, adjust nr_allocated */
sm_set_bitmap(ic->bitmap, bit, 1);
(*nr_allocations)++;
ll->nr_allocated++;
le32_add_cpu(&ic->ie_disk.nr_free, -1);
if (le32_to_cpu(ic->ie_disk.none_free_before) == bit)
ic->ie_disk.none_free_before = cpu_to_le32(bit + 1);
break;
case 1:
/* inc bitmap */
sm_set_bitmap(ic->bitmap, bit, 2);
break;
case 2:
/* inc bitmap and insert into overflow */
sm_set_bitmap(ic->bitmap, bit, 3);
reset_inc_context(ll, ic);
le_rc = cpu_to_le32(3);
__dm_bless_for_disk(&le_rc);
r = dm_btree_insert(&ll->ref_count_info, ll->ref_count_root,
&b, &le_rc, &ll->ref_count_root);
if (r < 0) {
DMERR("ref count insert failed");
return r;
}
break;
default:
/*
* inc within the overflow tree only.
*/
r = sm_ll_inc_overflow(ll, b, ic);
if (r < 0)
return r;
}
}
*new_b = b;
return 0;
}
/*
* Finds a bitmap that contains entries in the block range, and increments
* them.
*/
static int __sm_ll_inc(struct ll_disk *ll, dm_block_t b, dm_block_t e,
int32_t *nr_allocations, dm_block_t *new_b)
{
int r;
struct inc_context ic;
uint32_t bit, bit_end;
dm_block_t index = b;
init_inc_context(&ic);
bit = do_div(index, ll->entries_per_block);
r = ll->load_ie(ll, index, &ic.ie_disk);
if (r < 0)
return r;
r = shadow_bitmap(ll, &ic);
if (r)
return r;
bit_end = min(bit + (e - b), (dm_block_t) ll->entries_per_block);
r = sm_ll_inc_bitmap(ll, b, bit, bit_end, nr_allocations, new_b, &ic);
exit_inc_context(ll, &ic);
if (r)
return r;
return ll->save_ie(ll, index, &ic.ie_disk);
}
int sm_ll_inc(struct ll_disk *ll, dm_block_t b, dm_block_t e,
int32_t *nr_allocations)
{
*nr_allocations = 0;
while (b != e) {
int r = __sm_ll_inc(ll, b, e, nr_allocations, &b);
if (r)
return r;
}
return 0;
}
/*----------------------------------------------------------------*/
static int __sm_ll_del_overflow(struct ll_disk *ll, dm_block_t b,
struct inc_context *ic)
{
reset_inc_context(ll, ic);
return dm_btree_remove(&ll->ref_count_info, ll->ref_count_root,
&b, &ll->ref_count_root);
}
static int __sm_ll_dec_overflow(struct ll_disk *ll, dm_block_t b,
struct inc_context *ic, uint32_t *old_rc)
{
int r;
int index = -1;
struct btree_node *n;
__le32 *v_ptr;
uint32_t rc;
reset_inc_context(ll, ic);
r = btree_get_overwrite_leaf(&ll->ref_count_info, ll->ref_count_root,
b, &index, &ll->ref_count_root, &ic->overflow_leaf);
if (r < 0)
return r;
n = dm_block_data(ic->overflow_leaf);
if (!contains_key(n, b, index)) {
DMERR("overflow btree is missing an entry");
return -EINVAL;
}
v_ptr = value_ptr(n, index);
rc = le32_to_cpu(*v_ptr);
*old_rc = rc;
if (rc == 3)
return __sm_ll_del_overflow(ll, b, ic);
rc--;
*v_ptr = cpu_to_le32(rc);
return 0;
}
static int sm_ll_dec_overflow(struct ll_disk *ll, dm_block_t b,
struct inc_context *ic, uint32_t *old_rc)
{
/*
* Do we already have the correct overflow leaf?
*/
if (ic->overflow_leaf) {
int index;
struct btree_node *n;
__le32 *v_ptr;
uint32_t rc;
n = dm_block_data(ic->overflow_leaf);
index = lower_bound(n, b);
if (contains_key(n, b, index)) {
v_ptr = value_ptr(n, index);
rc = le32_to_cpu(*v_ptr);
*old_rc = rc;
if (rc > 3) {
rc--;
*v_ptr = cpu_to_le32(rc);
return 0;
} else {
return __sm_ll_del_overflow(ll, b, ic);
}
}
}
return __sm_ll_dec_overflow(ll, b, ic, old_rc);
}
/*
* Loops round incrementing entries in a single bitmap.
*/
static inline int sm_ll_dec_bitmap(struct ll_disk *ll, dm_block_t b,
uint32_t bit, uint32_t bit_end,
struct inc_context *ic,
int32_t *nr_allocations, dm_block_t *new_b)
{
int r;
uint32_t old;
for (; bit != bit_end; bit++, b++) {
/*
* We only need to drop the bitmap if we need to find a new btree
* leaf for the overflow. So if it was dropped last iteration,
* we now re-get it.
*/
r = ensure_bitmap(ll, ic);
if (r)
return r;
old = sm_lookup_bitmap(ic->bitmap, bit);
switch (old) {
case 0:
DMERR("unable to decrement block");
return -EINVAL;
case 1:
/* dec bitmap */
sm_set_bitmap(ic->bitmap, bit, 0);
(*nr_allocations)--;
ll->nr_allocated--;
le32_add_cpu(&ic->ie_disk.nr_free, 1);
ic->ie_disk.none_free_before =
cpu_to_le32(min(le32_to_cpu(ic->ie_disk.none_free_before), bit));
break;
case 2:
/* dec bitmap and insert into overflow */
sm_set_bitmap(ic->bitmap, bit, 1);
break;
case 3:
r = sm_ll_dec_overflow(ll, b, ic, &old);
if (r < 0)
return r;
if (old == 3) {
r = ensure_bitmap(ll, ic);
if (r)
return r;
sm_set_bitmap(ic->bitmap, bit, 2);
}
break;
}
}
*new_b = b;
return 0;
}
static int __sm_ll_dec(struct ll_disk *ll, dm_block_t b, dm_block_t e,
int32_t *nr_allocations, dm_block_t *new_b)
{
int r;
uint32_t bit, bit_end;
struct inc_context ic;
dm_block_t index = b;
init_inc_context(&ic);
bit = do_div(index, ll->entries_per_block);
r = ll->load_ie(ll, index, &ic.ie_disk);
if (r < 0)
return r;
r = shadow_bitmap(ll, &ic);
if (r)
return r;
bit_end = min(bit + (e - b), (dm_block_t) ll->entries_per_block);
r = sm_ll_dec_bitmap(ll, b, bit, bit_end, &ic, nr_allocations, new_b);
exit_inc_context(ll, &ic);
if (r)
return r;
return ll->save_ie(ll, index, &ic.ie_disk);
}
int sm_ll_dec(struct ll_disk *ll, dm_block_t b, dm_block_t e,
int32_t *nr_allocations)
{
*nr_allocations = 0;
while (b != e) {
int r = __sm_ll_dec(ll, b, e, nr_allocations, &b);
if (r)
return r;
}
return 0;
}
/*----------------------------------------------------------------*/
int sm_ll_commit(struct ll_disk *ll)
{
int r = 0;
if (ll->bitmap_index_changed) {
r = ll->commit(ll);
if (!r)
ll->bitmap_index_changed = false;
}
return r;
}
/*----------------------------------------------------------------*/
static int metadata_ll_load_ie(struct ll_disk *ll, dm_block_t index,
struct disk_index_entry *ie)
{
memcpy(ie, ll->mi_le.index + index, sizeof(*ie));
return 0;
}
static int metadata_ll_save_ie(struct ll_disk *ll, dm_block_t index,
struct disk_index_entry *ie)
{
ll->bitmap_index_changed = true;
memcpy(ll->mi_le.index + index, ie, sizeof(*ie));
return 0;
}
static int metadata_ll_init_index(struct ll_disk *ll)
{
int r;
struct dm_block *b;
r = dm_tm_new_block(ll->tm, &index_validator, &b);
if (r < 0)
return r;
ll->bitmap_root = dm_block_location(b);
dm_tm_unlock(ll->tm, b);
return 0;
}
static int metadata_ll_open(struct ll_disk *ll)
{
int r;
struct dm_block *block;
r = dm_tm_read_lock(ll->tm, ll->bitmap_root,
&index_validator, &block);
if (r)
return r;
memcpy(&ll->mi_le, dm_block_data(block), sizeof(ll->mi_le));
dm_tm_unlock(ll->tm, block);
return 0;
}
static dm_block_t metadata_ll_max_entries(struct ll_disk *ll)
{
return MAX_METADATA_BITMAPS;
}
static int metadata_ll_commit(struct ll_disk *ll)
{
int r, inc;
struct dm_block *b;
r = dm_tm_shadow_block(ll->tm, ll->bitmap_root, &index_validator, &b, &inc);
if (r)
return r;
memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
ll->bitmap_root = dm_block_location(b);
dm_tm_unlock(ll->tm, b);
return 0;
}
int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm)
{
int r;
r = sm_ll_init(ll, tm);
if (r < 0)
return r;
ll->load_ie = metadata_ll_load_ie;
ll->save_ie = metadata_ll_save_ie;
ll->init_index = metadata_ll_init_index;
ll->open_index = metadata_ll_open;
ll->max_entries = metadata_ll_max_entries;
ll->commit = metadata_ll_commit;
ll->nr_blocks = 0;
ll->nr_allocated = 0;
r = ll->init_index(ll);
if (r < 0)
return r;
r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
if (r < 0)
return r;
return 0;
}
int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm,
void *root_le, size_t len)
{
int r;
struct disk_sm_root smr;
if (len < sizeof(struct disk_sm_root)) {
DMERR("sm_metadata root too small");
return -ENOMEM;
}
/*
* We don't know the alignment of the root_le buffer, so need to
* copy into a new structure.
*/
memcpy(&smr, root_le, sizeof(smr));
r = sm_ll_init(ll, tm);
if (r < 0)
return r;
ll->load_ie = metadata_ll_load_ie;
ll->save_ie = metadata_ll_save_ie;
ll->init_index = metadata_ll_init_index;
ll->open_index = metadata_ll_open;
ll->max_entries = metadata_ll_max_entries;
ll->commit = metadata_ll_commit;
ll->nr_blocks = le64_to_cpu(smr.nr_blocks);
ll->nr_allocated = le64_to_cpu(smr.nr_allocated);
ll->bitmap_root = le64_to_cpu(smr.bitmap_root);
ll->ref_count_root = le64_to_cpu(smr.ref_count_root);
return ll->open_index(ll);
}
/*----------------------------------------------------------------*/
static inline int ie_cache_writeback(struct ll_disk *ll, struct ie_cache *iec)
{
iec->dirty = false;
__dm_bless_for_disk(iec->ie);
return dm_btree_insert(&ll->bitmap_info, ll->bitmap_root,
&iec->index, &iec->ie, &ll->bitmap_root);
}
static inline unsigned int hash_index(dm_block_t index)
{
return dm_hash_block(index, IE_CACHE_MASK);
}
static int disk_ll_load_ie(struct ll_disk *ll, dm_block_t index,
struct disk_index_entry *ie)
{
int r;
unsigned int h = hash_index(index);
struct ie_cache *iec = ll->ie_cache + h;
if (iec->valid) {
if (iec->index == index) {
memcpy(ie, &iec->ie, sizeof(*ie));
return 0;
}
if (iec->dirty) {
r = ie_cache_writeback(ll, iec);
if (r)
return r;
}
}
r = dm_btree_lookup(&ll->bitmap_info, ll->bitmap_root, &index, ie);
if (!r) {
iec->valid = true;
iec->dirty = false;
iec->index = index;
memcpy(&iec->ie, ie, sizeof(*ie));
}
return r;
}
static int disk_ll_save_ie(struct ll_disk *ll, dm_block_t index,
struct disk_index_entry *ie)
{
int r;
unsigned int h = hash_index(index);
struct ie_cache *iec = ll->ie_cache + h;
ll->bitmap_index_changed = true;
if (iec->valid) {
if (iec->index == index) {
memcpy(&iec->ie, ie, sizeof(*ie));
iec->dirty = true;
return 0;
}
if (iec->dirty) {
r = ie_cache_writeback(ll, iec);
if (r)
return r;
}
}
iec->valid = true;
iec->dirty = true;
iec->index = index;
memcpy(&iec->ie, ie, sizeof(*ie));
return 0;
}
static int disk_ll_init_index(struct ll_disk *ll)
{
unsigned int i;
for (i = 0; i < IE_CACHE_SIZE; i++) {
struct ie_cache *iec = ll->ie_cache + i;
iec->valid = false;
iec->dirty = false;
}
return dm_btree_empty(&ll->bitmap_info, &ll->bitmap_root);
}
static int disk_ll_open(struct ll_disk *ll)
{
return 0;
}
static dm_block_t disk_ll_max_entries(struct ll_disk *ll)
{
return -1ULL;
}
static int disk_ll_commit(struct ll_disk *ll)
{
int r = 0;
unsigned int i;
for (i = 0; i < IE_CACHE_SIZE; i++) {
struct ie_cache *iec = ll->ie_cache + i;
if (iec->valid && iec->dirty)
r = ie_cache_writeback(ll, iec);
}
return r;
}
int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm)
{
int r;
r = sm_ll_init(ll, tm);
if (r < 0)
return r;
ll->load_ie = disk_ll_load_ie;
ll->save_ie = disk_ll_save_ie;
ll->init_index = disk_ll_init_index;
ll->open_index = disk_ll_open;
ll->max_entries = disk_ll_max_entries;
ll->commit = disk_ll_commit;
ll->nr_blocks = 0;
ll->nr_allocated = 0;
r = ll->init_index(ll);
if (r < 0)
return r;
r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
if (r < 0)
return r;
return 0;
}
int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm,
void *root_le, size_t len)
{
int r;
struct disk_sm_root *smr = root_le;
if (len < sizeof(struct disk_sm_root)) {
DMERR("sm_metadata root too small");
return -ENOMEM;
}
r = sm_ll_init(ll, tm);
if (r < 0)
return r;
ll->load_ie = disk_ll_load_ie;
ll->save_ie = disk_ll_save_ie;
ll->init_index = disk_ll_init_index;
ll->open_index = disk_ll_open;
ll->max_entries = disk_ll_max_entries;
ll->commit = disk_ll_commit;
ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
return ll->open_index(ll);
}
/*----------------------------------------------------------------*/
| linux-master | drivers/md/persistent-data/dm-space-map-common.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2011 Red Hat, Inc.
*
* This file is released under the GPL.
*/
#include "dm-block-manager.h"
#include "dm-persistent-data-internal.h"
#include <linux/dm-bufio.h>
#include <linux/crc32c.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/rwsem.h>
#include <linux/device-mapper.h>
#include <linux/stacktrace.h>
#include <linux/sched/task.h>
#define DM_MSG_PREFIX "block manager"
/*----------------------------------------------------------------*/
#ifdef CONFIG_DM_DEBUG_BLOCK_MANAGER_LOCKING
/*
* This is a read/write semaphore with a couple of differences.
*
* i) There is a restriction on the number of concurrent read locks that
* may be held at once. This is just an implementation detail.
*
* ii) Recursive locking attempts are detected and return EINVAL. A stack
* trace is also emitted for the previous lock acquisition.
*
* iii) Priority is given to write locks.
*/
#define MAX_HOLDERS 4
#define MAX_STACK 10
struct stack_store {
unsigned int nr_entries;
unsigned long entries[MAX_STACK];
};
struct block_lock {
spinlock_t lock;
__s32 count;
struct list_head waiters;
struct task_struct *holders[MAX_HOLDERS];
#ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
struct stack_store traces[MAX_HOLDERS];
#endif
};
struct waiter {
struct list_head list;
struct task_struct *task;
int wants_write;
};
static unsigned int __find_holder(struct block_lock *lock,
struct task_struct *task)
{
unsigned int i;
for (i = 0; i < MAX_HOLDERS; i++)
if (lock->holders[i] == task)
break;
BUG_ON(i == MAX_HOLDERS);
return i;
}
/* call this *after* you increment lock->count */
static void __add_holder(struct block_lock *lock, struct task_struct *task)
{
unsigned int h = __find_holder(lock, NULL);
#ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
struct stack_store *t;
#endif
get_task_struct(task);
lock->holders[h] = task;
#ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
t = lock->traces + h;
t->nr_entries = stack_trace_save(t->entries, MAX_STACK, 2);
#endif
}
/* call this *before* you decrement lock->count */
static void __del_holder(struct block_lock *lock, struct task_struct *task)
{
unsigned int h = __find_holder(lock, task);
lock->holders[h] = NULL;
put_task_struct(task);
}
static int __check_holder(struct block_lock *lock)
{
unsigned int i;
for (i = 0; i < MAX_HOLDERS; i++) {
if (lock->holders[i] == current) {
DMERR("recursive lock detected in metadata");
#ifdef CONFIG_DM_DEBUG_BLOCK_STACK_TRACING
DMERR("previously held here:");
stack_trace_print(lock->traces[i].entries,
lock->traces[i].nr_entries, 4);
DMERR("subsequent acquisition attempted here:");
dump_stack();
#endif
return -EINVAL;
}
}
return 0;
}
static void __wait(struct waiter *w)
{
for (;;) {
set_current_state(TASK_UNINTERRUPTIBLE);
if (!w->task)
break;
schedule();
}
set_current_state(TASK_RUNNING);
}
static void __wake_waiter(struct waiter *w)
{
struct task_struct *task;
list_del(&w->list);
task = w->task;
smp_mb();
w->task = NULL;
wake_up_process(task);
}
/*
* We either wake a few readers or a single writer.
*/
static void __wake_many(struct block_lock *lock)
{
struct waiter *w, *tmp;
BUG_ON(lock->count < 0);
list_for_each_entry_safe(w, tmp, &lock->waiters, list) {
if (lock->count >= MAX_HOLDERS)
return;
if (w->wants_write) {
if (lock->count > 0)
return; /* still read locked */
lock->count = -1;
__add_holder(lock, w->task);
__wake_waiter(w);
return;
}
lock->count++;
__add_holder(lock, w->task);
__wake_waiter(w);
}
}
static void bl_init(struct block_lock *lock)
{
int i;
spin_lock_init(&lock->lock);
lock->count = 0;
INIT_LIST_HEAD(&lock->waiters);
for (i = 0; i < MAX_HOLDERS; i++)
lock->holders[i] = NULL;
}
static int __available_for_read(struct block_lock *lock)
{
return lock->count >= 0 &&
lock->count < MAX_HOLDERS &&
list_empty(&lock->waiters);
}
static int bl_down_read(struct block_lock *lock)
{
int r;
struct waiter w;
spin_lock(&lock->lock);
r = __check_holder(lock);
if (r) {
spin_unlock(&lock->lock);
return r;
}
if (__available_for_read(lock)) {
lock->count++;
__add_holder(lock, current);
spin_unlock(&lock->lock);
return 0;
}
get_task_struct(current);
w.task = current;
w.wants_write = 0;
list_add_tail(&w.list, &lock->waiters);
spin_unlock(&lock->lock);
__wait(&w);
put_task_struct(current);
return 0;
}
static int bl_down_read_nonblock(struct block_lock *lock)
{
int r;
spin_lock(&lock->lock);
r = __check_holder(lock);
if (r)
goto out;
if (__available_for_read(lock)) {
lock->count++;
__add_holder(lock, current);
r = 0;
} else
r = -EWOULDBLOCK;
out:
spin_unlock(&lock->lock);
return r;
}
static void bl_up_read(struct block_lock *lock)
{
spin_lock(&lock->lock);
BUG_ON(lock->count <= 0);
__del_holder(lock, current);
--lock->count;
if (!list_empty(&lock->waiters))
__wake_many(lock);
spin_unlock(&lock->lock);
}
static int bl_down_write(struct block_lock *lock)
{
int r;
struct waiter w;
spin_lock(&lock->lock);
r = __check_holder(lock);
if (r) {
spin_unlock(&lock->lock);
return r;
}
if (lock->count == 0 && list_empty(&lock->waiters)) {
lock->count = -1;
__add_holder(lock, current);
spin_unlock(&lock->lock);
return 0;
}
get_task_struct(current);
w.task = current;
w.wants_write = 1;
/*
* Writers given priority. We know there's only one mutator in the
* system, so ignoring the ordering reversal.
*/
list_add(&w.list, &lock->waiters);
spin_unlock(&lock->lock);
__wait(&w);
put_task_struct(current);
return 0;
}
static void bl_up_write(struct block_lock *lock)
{
spin_lock(&lock->lock);
__del_holder(lock, current);
lock->count = 0;
if (!list_empty(&lock->waiters))
__wake_many(lock);
spin_unlock(&lock->lock);
}
static void report_recursive_bug(dm_block_t b, int r)
{
if (r == -EINVAL)
DMERR("recursive acquisition of block %llu requested.",
(unsigned long long) b);
}
#else /* !CONFIG_DM_DEBUG_BLOCK_MANAGER_LOCKING */
#define bl_init(x) do { } while (0)
#define bl_down_read(x) 0
#define bl_down_read_nonblock(x) 0
#define bl_up_read(x) do { } while (0)
#define bl_down_write(x) 0
#define bl_up_write(x) do { } while (0)
#define report_recursive_bug(x, y) do { } while (0)
#endif /* CONFIG_DM_DEBUG_BLOCK_MANAGER_LOCKING */
/*----------------------------------------------------------------*/
/*
* Block manager is currently implemented using dm-bufio. struct
* dm_block_manager and struct dm_block map directly onto a couple of
* structs in the bufio interface. I want to retain the freedom to move
* away from bufio in the future. So these structs are just cast within
* this .c file, rather than making it through to the public interface.
*/
static struct dm_buffer *to_buffer(struct dm_block *b)
{
return (struct dm_buffer *) b;
}
dm_block_t dm_block_location(struct dm_block *b)
{
return dm_bufio_get_block_number(to_buffer(b));
}
EXPORT_SYMBOL_GPL(dm_block_location);
void *dm_block_data(struct dm_block *b)
{
return dm_bufio_get_block_data(to_buffer(b));
}
EXPORT_SYMBOL_GPL(dm_block_data);
struct buffer_aux {
struct dm_block_validator *validator;
int write_locked;
#ifdef CONFIG_DM_DEBUG_BLOCK_MANAGER_LOCKING
struct block_lock lock;
#endif
};
static void dm_block_manager_alloc_callback(struct dm_buffer *buf)
{
struct buffer_aux *aux = dm_bufio_get_aux_data(buf);
aux->validator = NULL;
bl_init(&aux->lock);
}
static void dm_block_manager_write_callback(struct dm_buffer *buf)
{
struct buffer_aux *aux = dm_bufio_get_aux_data(buf);
if (aux->validator) {
aux->validator->prepare_for_write(aux->validator, (struct dm_block *) buf,
dm_bufio_get_block_size(dm_bufio_get_client(buf)));
}
}
/*
* -------------------------------------------------------------
* Public interface
*--------------------------------------------------------------
*/
struct dm_block_manager {
struct dm_bufio_client *bufio;
bool read_only:1;
};
struct dm_block_manager *dm_block_manager_create(struct block_device *bdev,
unsigned int block_size,
unsigned int max_held_per_thread)
{
int r;
struct dm_block_manager *bm;
bm = kmalloc(sizeof(*bm), GFP_KERNEL);
if (!bm) {
r = -ENOMEM;
goto bad;
}
bm->bufio = dm_bufio_client_create(bdev, block_size, max_held_per_thread,
sizeof(struct buffer_aux),
dm_block_manager_alloc_callback,
dm_block_manager_write_callback,
0);
if (IS_ERR(bm->bufio)) {
r = PTR_ERR(bm->bufio);
kfree(bm);
goto bad;
}
bm->read_only = false;
return bm;
bad:
return ERR_PTR(r);
}
EXPORT_SYMBOL_GPL(dm_block_manager_create);
void dm_block_manager_destroy(struct dm_block_manager *bm)
{
dm_bufio_client_destroy(bm->bufio);
kfree(bm);
}
EXPORT_SYMBOL_GPL(dm_block_manager_destroy);
void dm_block_manager_reset(struct dm_block_manager *bm)
{
dm_bufio_client_reset(bm->bufio);
}
EXPORT_SYMBOL_GPL(dm_block_manager_reset);
unsigned int dm_bm_block_size(struct dm_block_manager *bm)
{
return dm_bufio_get_block_size(bm->bufio);
}
EXPORT_SYMBOL_GPL(dm_bm_block_size);
dm_block_t dm_bm_nr_blocks(struct dm_block_manager *bm)
{
return dm_bufio_get_device_size(bm->bufio);
}
static int dm_bm_validate_buffer(struct dm_block_manager *bm,
struct dm_buffer *buf,
struct buffer_aux *aux,
struct dm_block_validator *v)
{
if (unlikely(!aux->validator)) {
int r;
if (!v)
return 0;
r = v->check(v, (struct dm_block *) buf, dm_bufio_get_block_size(bm->bufio));
if (unlikely(r)) {
DMERR_LIMIT("%s validator check failed for block %llu", v->name,
(unsigned long long) dm_bufio_get_block_number(buf));
return r;
}
aux->validator = v;
} else {
if (unlikely(aux->validator != v)) {
DMERR_LIMIT("validator mismatch (old=%s vs new=%s) for block %llu",
aux->validator->name, v ? v->name : "NULL",
(unsigned long long) dm_bufio_get_block_number(buf));
return -EINVAL;
}
}
return 0;
}
int dm_bm_read_lock(struct dm_block_manager *bm, dm_block_t b,
struct dm_block_validator *v,
struct dm_block **result)
{
struct buffer_aux *aux;
void *p;
int r;
p = dm_bufio_read(bm->bufio, b, (struct dm_buffer **) result);
if (IS_ERR(p))
return PTR_ERR(p);
aux = dm_bufio_get_aux_data(to_buffer(*result));
r = bl_down_read(&aux->lock);
if (unlikely(r)) {
dm_bufio_release(to_buffer(*result));
report_recursive_bug(b, r);
return r;
}
aux->write_locked = 0;
r = dm_bm_validate_buffer(bm, to_buffer(*result), aux, v);
if (unlikely(r)) {
bl_up_read(&aux->lock);
dm_bufio_release(to_buffer(*result));
return r;
}
return 0;
}
EXPORT_SYMBOL_GPL(dm_bm_read_lock);
int dm_bm_write_lock(struct dm_block_manager *bm,
dm_block_t b, struct dm_block_validator *v,
struct dm_block **result)
{
struct buffer_aux *aux;
void *p;
int r;
if (dm_bm_is_read_only(bm))
return -EPERM;
p = dm_bufio_read(bm->bufio, b, (struct dm_buffer **) result);
if (IS_ERR(p))
return PTR_ERR(p);
aux = dm_bufio_get_aux_data(to_buffer(*result));
r = bl_down_write(&aux->lock);
if (r) {
dm_bufio_release(to_buffer(*result));
report_recursive_bug(b, r);
return r;
}
aux->write_locked = 1;
r = dm_bm_validate_buffer(bm, to_buffer(*result), aux, v);
if (unlikely(r)) {
bl_up_write(&aux->lock);
dm_bufio_release(to_buffer(*result));
return r;
}
return 0;
}
EXPORT_SYMBOL_GPL(dm_bm_write_lock);
int dm_bm_read_try_lock(struct dm_block_manager *bm,
dm_block_t b, struct dm_block_validator *v,
struct dm_block **result)
{
struct buffer_aux *aux;
void *p;
int r;
p = dm_bufio_get(bm->bufio, b, (struct dm_buffer **) result);
if (IS_ERR(p))
return PTR_ERR(p);
if (unlikely(!p))
return -EWOULDBLOCK;
aux = dm_bufio_get_aux_data(to_buffer(*result));
r = bl_down_read_nonblock(&aux->lock);
if (r < 0) {
dm_bufio_release(to_buffer(*result));
report_recursive_bug(b, r);
return r;
}
aux->write_locked = 0;
r = dm_bm_validate_buffer(bm, to_buffer(*result), aux, v);
if (unlikely(r)) {
bl_up_read(&aux->lock);
dm_bufio_release(to_buffer(*result));
return r;
}
return 0;
}
int dm_bm_write_lock_zero(struct dm_block_manager *bm,
dm_block_t b, struct dm_block_validator *v,
struct dm_block **result)
{
int r;
struct buffer_aux *aux;
void *p;
if (dm_bm_is_read_only(bm))
return -EPERM;
p = dm_bufio_new(bm->bufio, b, (struct dm_buffer **) result);
if (IS_ERR(p))
return PTR_ERR(p);
memset(p, 0, dm_bm_block_size(bm));
aux = dm_bufio_get_aux_data(to_buffer(*result));
r = bl_down_write(&aux->lock);
if (r) {
dm_bufio_release(to_buffer(*result));
return r;
}
aux->write_locked = 1;
aux->validator = v;
return 0;
}
EXPORT_SYMBOL_GPL(dm_bm_write_lock_zero);
void dm_bm_unlock(struct dm_block *b)
{
struct buffer_aux *aux = dm_bufio_get_aux_data(to_buffer(b));
if (aux->write_locked) {
dm_bufio_mark_buffer_dirty(to_buffer(b));
bl_up_write(&aux->lock);
} else
bl_up_read(&aux->lock);
dm_bufio_release(to_buffer(b));
}
EXPORT_SYMBOL_GPL(dm_bm_unlock);
int dm_bm_flush(struct dm_block_manager *bm)
{
if (dm_bm_is_read_only(bm))
return -EPERM;
return dm_bufio_write_dirty_buffers(bm->bufio);
}
EXPORT_SYMBOL_GPL(dm_bm_flush);
void dm_bm_prefetch(struct dm_block_manager *bm, dm_block_t b)
{
dm_bufio_prefetch(bm->bufio, b, 1);
}
bool dm_bm_is_read_only(struct dm_block_manager *bm)
{
return bm ? bm->read_only : true;
}
EXPORT_SYMBOL_GPL(dm_bm_is_read_only);
void dm_bm_set_read_only(struct dm_block_manager *bm)
{
if (bm)
bm->read_only = true;
}
EXPORT_SYMBOL_GPL(dm_bm_set_read_only);
void dm_bm_set_read_write(struct dm_block_manager *bm)
{
if (bm)
bm->read_only = false;
}
EXPORT_SYMBOL_GPL(dm_bm_set_read_write);
u32 dm_bm_checksum(const void *data, size_t len, u32 init_xor)
{
return crc32c(~(u32) 0, data, len) ^ init_xor;
}
EXPORT_SYMBOL_GPL(dm_bm_checksum);
/*----------------------------------------------------------------*/
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Joe Thornber <[email protected]>");
MODULE_DESCRIPTION("Immutable metadata library for dm");
/*----------------------------------------------------------------*/
| linux-master | drivers/md/persistent-data/dm-block-manager.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2011 Red Hat, Inc.
*
* This file is released under the GPL.
*/
#include "dm-transaction-manager.h"
#include "dm-space-map.h"
#include "dm-space-map-disk.h"
#include "dm-space-map-metadata.h"
#include "dm-persistent-data-internal.h"
#include <linux/export.h>
#include <linux/mutex.h>
#include <linux/hash.h>
#include <linux/slab.h>
#include <linux/device-mapper.h>
#define DM_MSG_PREFIX "transaction manager"
/*----------------------------------------------------------------*/
#define PREFETCH_SIZE 128
#define PREFETCH_BITS 7
#define PREFETCH_SENTINEL ((dm_block_t) -1ULL)
struct prefetch_set {
struct mutex lock;
dm_block_t blocks[PREFETCH_SIZE];
};
static unsigned int prefetch_hash(dm_block_t b)
{
return hash_64(b, PREFETCH_BITS);
}
static void prefetch_wipe(struct prefetch_set *p)
{
unsigned int i;
for (i = 0; i < PREFETCH_SIZE; i++)
p->blocks[i] = PREFETCH_SENTINEL;
}
static void prefetch_init(struct prefetch_set *p)
{
mutex_init(&p->lock);
prefetch_wipe(p);
}
static void prefetch_add(struct prefetch_set *p, dm_block_t b)
{
unsigned int h = prefetch_hash(b);
mutex_lock(&p->lock);
if (p->blocks[h] == PREFETCH_SENTINEL)
p->blocks[h] = b;
mutex_unlock(&p->lock);
}
static void prefetch_issue(struct prefetch_set *p, struct dm_block_manager *bm)
{
unsigned int i;
mutex_lock(&p->lock);
for (i = 0; i < PREFETCH_SIZE; i++)
if (p->blocks[i] != PREFETCH_SENTINEL) {
dm_bm_prefetch(bm, p->blocks[i]);
p->blocks[i] = PREFETCH_SENTINEL;
}
mutex_unlock(&p->lock);
}
/*----------------------------------------------------------------*/
struct shadow_info {
struct hlist_node hlist;
dm_block_t where;
};
/*
* It would be nice if we scaled with the size of transaction.
*/
#define DM_HASH_SIZE 256
#define DM_HASH_MASK (DM_HASH_SIZE - 1)
struct dm_transaction_manager {
int is_clone;
struct dm_transaction_manager *real;
struct dm_block_manager *bm;
struct dm_space_map *sm;
spinlock_t lock;
struct hlist_head buckets[DM_HASH_SIZE];
struct prefetch_set prefetches;
};
/*----------------------------------------------------------------*/
static int is_shadow(struct dm_transaction_manager *tm, dm_block_t b)
{
int r = 0;
unsigned int bucket = dm_hash_block(b, DM_HASH_MASK);
struct shadow_info *si;
spin_lock(&tm->lock);
hlist_for_each_entry(si, tm->buckets + bucket, hlist)
if (si->where == b) {
r = 1;
break;
}
spin_unlock(&tm->lock);
return r;
}
/*
* This can silently fail if there's no memory. We're ok with this since
* creating redundant shadows causes no harm.
*/
static void insert_shadow(struct dm_transaction_manager *tm, dm_block_t b)
{
unsigned int bucket;
struct shadow_info *si;
si = kmalloc(sizeof(*si), GFP_NOIO);
if (si) {
si->where = b;
bucket = dm_hash_block(b, DM_HASH_MASK);
spin_lock(&tm->lock);
hlist_add_head(&si->hlist, tm->buckets + bucket);
spin_unlock(&tm->lock);
}
}
static void wipe_shadow_table(struct dm_transaction_manager *tm)
{
struct shadow_info *si;
struct hlist_node *tmp;
struct hlist_head *bucket;
int i;
spin_lock(&tm->lock);
for (i = 0; i < DM_HASH_SIZE; i++) {
bucket = tm->buckets + i;
hlist_for_each_entry_safe(si, tmp, bucket, hlist)
kfree(si);
INIT_HLIST_HEAD(bucket);
}
spin_unlock(&tm->lock);
}
/*----------------------------------------------------------------*/
static struct dm_transaction_manager *dm_tm_create(struct dm_block_manager *bm,
struct dm_space_map *sm)
{
int i;
struct dm_transaction_manager *tm;
tm = kmalloc(sizeof(*tm), GFP_KERNEL);
if (!tm)
return ERR_PTR(-ENOMEM);
tm->is_clone = 0;
tm->real = NULL;
tm->bm = bm;
tm->sm = sm;
spin_lock_init(&tm->lock);
for (i = 0; i < DM_HASH_SIZE; i++)
INIT_HLIST_HEAD(tm->buckets + i);
prefetch_init(&tm->prefetches);
return tm;
}
struct dm_transaction_manager *dm_tm_create_non_blocking_clone(struct dm_transaction_manager *real)
{
struct dm_transaction_manager *tm;
tm = kmalloc(sizeof(*tm), GFP_KERNEL);
if (tm) {
tm->is_clone = 1;
tm->real = real;
}
return tm;
}
EXPORT_SYMBOL_GPL(dm_tm_create_non_blocking_clone);
void dm_tm_destroy(struct dm_transaction_manager *tm)
{
if (!tm)
return;
if (!tm->is_clone)
wipe_shadow_table(tm);
kfree(tm);
}
EXPORT_SYMBOL_GPL(dm_tm_destroy);
int dm_tm_pre_commit(struct dm_transaction_manager *tm)
{
int r;
if (tm->is_clone)
return -EWOULDBLOCK;
r = dm_sm_commit(tm->sm);
if (r < 0)
return r;
return dm_bm_flush(tm->bm);
}
EXPORT_SYMBOL_GPL(dm_tm_pre_commit);
int dm_tm_commit(struct dm_transaction_manager *tm, struct dm_block *root)
{
if (tm->is_clone)
return -EWOULDBLOCK;
wipe_shadow_table(tm);
dm_bm_unlock(root);
return dm_bm_flush(tm->bm);
}
EXPORT_SYMBOL_GPL(dm_tm_commit);
int dm_tm_new_block(struct dm_transaction_manager *tm,
struct dm_block_validator *v,
struct dm_block **result)
{
int r;
dm_block_t new_block;
if (tm->is_clone)
return -EWOULDBLOCK;
r = dm_sm_new_block(tm->sm, &new_block);
if (r < 0)
return r;
r = dm_bm_write_lock_zero(tm->bm, new_block, v, result);
if (r < 0) {
dm_sm_dec_block(tm->sm, new_block);
return r;
}
/*
* New blocks count as shadows in that they don't need to be
* shadowed again.
*/
insert_shadow(tm, new_block);
return 0;
}
static int __shadow_block(struct dm_transaction_manager *tm, dm_block_t orig,
struct dm_block_validator *v,
struct dm_block **result)
{
int r;
dm_block_t new;
struct dm_block *orig_block;
r = dm_sm_new_block(tm->sm, &new);
if (r < 0)
return r;
r = dm_sm_dec_block(tm->sm, orig);
if (r < 0)
return r;
r = dm_bm_read_lock(tm->bm, orig, v, &orig_block);
if (r < 0)
return r;
/*
* It would be tempting to use dm_bm_unlock_move here, but some
* code, such as the space maps, keeps using the old data structures
* secure in the knowledge they won't be changed until the next
* transaction. Using unlock_move would force a synchronous read
* since the old block would no longer be in the cache.
*/
r = dm_bm_write_lock_zero(tm->bm, new, v, result);
if (r) {
dm_bm_unlock(orig_block);
return r;
}
memcpy(dm_block_data(*result), dm_block_data(orig_block),
dm_bm_block_size(tm->bm));
dm_bm_unlock(orig_block);
return r;
}
int dm_tm_shadow_block(struct dm_transaction_manager *tm, dm_block_t orig,
struct dm_block_validator *v, struct dm_block **result,
int *inc_children)
{
int r;
if (tm->is_clone)
return -EWOULDBLOCK;
r = dm_sm_count_is_more_than_one(tm->sm, orig, inc_children);
if (r < 0)
return r;
if (is_shadow(tm, orig) && !*inc_children)
return dm_bm_write_lock(tm->bm, orig, v, result);
r = __shadow_block(tm, orig, v, result);
if (r < 0)
return r;
insert_shadow(tm, dm_block_location(*result));
return r;
}
EXPORT_SYMBOL_GPL(dm_tm_shadow_block);
int dm_tm_read_lock(struct dm_transaction_manager *tm, dm_block_t b,
struct dm_block_validator *v,
struct dm_block **blk)
{
if (tm->is_clone) {
int r = dm_bm_read_try_lock(tm->real->bm, b, v, blk);
if (r == -EWOULDBLOCK)
prefetch_add(&tm->real->prefetches, b);
return r;
}
return dm_bm_read_lock(tm->bm, b, v, blk);
}
EXPORT_SYMBOL_GPL(dm_tm_read_lock);
void dm_tm_unlock(struct dm_transaction_manager *tm, struct dm_block *b)
{
dm_bm_unlock(b);
}
EXPORT_SYMBOL_GPL(dm_tm_unlock);
void dm_tm_inc(struct dm_transaction_manager *tm, dm_block_t b)
{
/*
* The non-blocking clone doesn't support this.
*/
BUG_ON(tm->is_clone);
dm_sm_inc_block(tm->sm, b);
}
EXPORT_SYMBOL_GPL(dm_tm_inc);
void dm_tm_inc_range(struct dm_transaction_manager *tm, dm_block_t b, dm_block_t e)
{
/*
* The non-blocking clone doesn't support this.
*/
BUG_ON(tm->is_clone);
dm_sm_inc_blocks(tm->sm, b, e);
}
EXPORT_SYMBOL_GPL(dm_tm_inc_range);
void dm_tm_dec(struct dm_transaction_manager *tm, dm_block_t b)
{
/*
* The non-blocking clone doesn't support this.
*/
BUG_ON(tm->is_clone);
dm_sm_dec_block(tm->sm, b);
}
EXPORT_SYMBOL_GPL(dm_tm_dec);
void dm_tm_dec_range(struct dm_transaction_manager *tm, dm_block_t b, dm_block_t e)
{
/*
* The non-blocking clone doesn't support this.
*/
BUG_ON(tm->is_clone);
dm_sm_dec_blocks(tm->sm, b, e);
}
EXPORT_SYMBOL_GPL(dm_tm_dec_range);
void dm_tm_with_runs(struct dm_transaction_manager *tm,
const __le64 *value_le, unsigned int count, dm_tm_run_fn fn)
{
uint64_t b, begin, end;
bool in_run = false;
unsigned int i;
for (i = 0; i < count; i++, value_le++) {
b = le64_to_cpu(*value_le);
if (in_run) {
if (b == end)
end++;
else {
fn(tm, begin, end);
begin = b;
end = b + 1;
}
} else {
in_run = true;
begin = b;
end = b + 1;
}
}
if (in_run)
fn(tm, begin, end);
}
EXPORT_SYMBOL_GPL(dm_tm_with_runs);
int dm_tm_ref(struct dm_transaction_manager *tm, dm_block_t b,
uint32_t *result)
{
if (tm->is_clone)
return -EWOULDBLOCK;
return dm_sm_get_count(tm->sm, b, result);
}
int dm_tm_block_is_shared(struct dm_transaction_manager *tm, dm_block_t b,
int *result)
{
if (tm->is_clone)
return -EWOULDBLOCK;
return dm_sm_count_is_more_than_one(tm->sm, b, result);
}
struct dm_block_manager *dm_tm_get_bm(struct dm_transaction_manager *tm)
{
return tm->bm;
}
void dm_tm_issue_prefetches(struct dm_transaction_manager *tm)
{
prefetch_issue(&tm->prefetches, tm->bm);
}
EXPORT_SYMBOL_GPL(dm_tm_issue_prefetches);
/*----------------------------------------------------------------*/
static int dm_tm_create_internal(struct dm_block_manager *bm,
dm_block_t sb_location,
struct dm_transaction_manager **tm,
struct dm_space_map **sm,
int create,
void *sm_root, size_t sm_len)
{
int r;
*sm = dm_sm_metadata_init();
if (IS_ERR(*sm))
return PTR_ERR(*sm);
*tm = dm_tm_create(bm, *sm);
if (IS_ERR(*tm)) {
dm_sm_destroy(*sm);
return PTR_ERR(*tm);
}
if (create) {
r = dm_sm_metadata_create(*sm, *tm, dm_bm_nr_blocks(bm),
sb_location);
if (r) {
DMERR("couldn't create metadata space map");
goto bad;
}
} else {
r = dm_sm_metadata_open(*sm, *tm, sm_root, sm_len);
if (r) {
DMERR("couldn't open metadata space map");
goto bad;
}
}
return 0;
bad:
dm_tm_destroy(*tm);
dm_sm_destroy(*sm);
return r;
}
int dm_tm_create_with_sm(struct dm_block_manager *bm, dm_block_t sb_location,
struct dm_transaction_manager **tm,
struct dm_space_map **sm)
{
return dm_tm_create_internal(bm, sb_location, tm, sm, 1, NULL, 0);
}
EXPORT_SYMBOL_GPL(dm_tm_create_with_sm);
int dm_tm_open_with_sm(struct dm_block_manager *bm, dm_block_t sb_location,
void *sm_root, size_t root_len,
struct dm_transaction_manager **tm,
struct dm_space_map **sm)
{
return dm_tm_create_internal(bm, sb_location, tm, sm, 0, sm_root, root_len);
}
EXPORT_SYMBOL_GPL(dm_tm_open_with_sm);
/*----------------------------------------------------------------*/
| linux-master | drivers/md/persistent-data/dm-transaction-manager.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012 Red Hat, Inc.
*
* This file is released under the GPL.
*/
#include "dm-bitset.h"
#include "dm-transaction-manager.h"
#include <linux/export.h>
#include <linux/device-mapper.h>
#define DM_MSG_PREFIX "bitset"
#define BITS_PER_ARRAY_ENTRY 64
/*----------------------------------------------------------------*/
static struct dm_btree_value_type bitset_bvt = {
.context = NULL,
.size = sizeof(__le64),
.inc = NULL,
.dec = NULL,
.equal = NULL,
};
/*----------------------------------------------------------------*/
void dm_disk_bitset_init(struct dm_transaction_manager *tm,
struct dm_disk_bitset *info)
{
dm_array_info_init(&info->array_info, tm, &bitset_bvt);
info->current_index_set = false;
}
EXPORT_SYMBOL_GPL(dm_disk_bitset_init);
int dm_bitset_empty(struct dm_disk_bitset *info, dm_block_t *root)
{
return dm_array_empty(&info->array_info, root);
}
EXPORT_SYMBOL_GPL(dm_bitset_empty);
struct packer_context {
bit_value_fn fn;
unsigned int nr_bits;
void *context;
};
static int pack_bits(uint32_t index, void *value, void *context)
{
int r;
struct packer_context *p = context;
unsigned int bit, nr = min(64u, p->nr_bits - (index * 64));
uint64_t word = 0;
bool bv;
for (bit = 0; bit < nr; bit++) {
r = p->fn(index * 64 + bit, &bv, p->context);
if (r)
return r;
if (bv)
set_bit(bit, (unsigned long *) &word);
else
clear_bit(bit, (unsigned long *) &word);
}
*((__le64 *) value) = cpu_to_le64(word);
return 0;
}
int dm_bitset_new(struct dm_disk_bitset *info, dm_block_t *root,
uint32_t size, bit_value_fn fn, void *context)
{
struct packer_context p;
p.fn = fn;
p.nr_bits = size;
p.context = context;
return dm_array_new(&info->array_info, root, dm_div_up(size, 64), pack_bits, &p);
}
EXPORT_SYMBOL_GPL(dm_bitset_new);
int dm_bitset_resize(struct dm_disk_bitset *info, dm_block_t root,
uint32_t old_nr_entries, uint32_t new_nr_entries,
bool default_value, dm_block_t *new_root)
{
uint32_t old_blocks = dm_div_up(old_nr_entries, BITS_PER_ARRAY_ENTRY);
uint32_t new_blocks = dm_div_up(new_nr_entries, BITS_PER_ARRAY_ENTRY);
__le64 value = default_value ? cpu_to_le64(~0) : cpu_to_le64(0);
__dm_bless_for_disk(&value);
return dm_array_resize(&info->array_info, root, old_blocks, new_blocks,
&value, new_root);
}
EXPORT_SYMBOL_GPL(dm_bitset_resize);
int dm_bitset_del(struct dm_disk_bitset *info, dm_block_t root)
{
return dm_array_del(&info->array_info, root);
}
EXPORT_SYMBOL_GPL(dm_bitset_del);
int dm_bitset_flush(struct dm_disk_bitset *info, dm_block_t root,
dm_block_t *new_root)
{
int r;
__le64 value;
if (!info->current_index_set || !info->dirty)
return 0;
value = cpu_to_le64(info->current_bits);
__dm_bless_for_disk(&value);
r = dm_array_set_value(&info->array_info, root, info->current_index,
&value, new_root);
if (r)
return r;
info->current_index_set = false;
info->dirty = false;
return 0;
}
EXPORT_SYMBOL_GPL(dm_bitset_flush);
static int read_bits(struct dm_disk_bitset *info, dm_block_t root,
uint32_t array_index)
{
int r;
__le64 value;
r = dm_array_get_value(&info->array_info, root, array_index, &value);
if (r)
return r;
info->current_bits = le64_to_cpu(value);
info->current_index_set = true;
info->current_index = array_index;
info->dirty = false;
return 0;
}
static int get_array_entry(struct dm_disk_bitset *info, dm_block_t root,
uint32_t index, dm_block_t *new_root)
{
int r;
unsigned int array_index = index / BITS_PER_ARRAY_ENTRY;
if (info->current_index_set) {
if (info->current_index == array_index)
return 0;
r = dm_bitset_flush(info, root, new_root);
if (r)
return r;
}
return read_bits(info, root, array_index);
}
int dm_bitset_set_bit(struct dm_disk_bitset *info, dm_block_t root,
uint32_t index, dm_block_t *new_root)
{
int r;
unsigned int b = index % BITS_PER_ARRAY_ENTRY;
r = get_array_entry(info, root, index, new_root);
if (r)
return r;
set_bit(b, (unsigned long *) &info->current_bits);
info->dirty = true;
return 0;
}
EXPORT_SYMBOL_GPL(dm_bitset_set_bit);
int dm_bitset_clear_bit(struct dm_disk_bitset *info, dm_block_t root,
uint32_t index, dm_block_t *new_root)
{
int r;
unsigned int b = index % BITS_PER_ARRAY_ENTRY;
r = get_array_entry(info, root, index, new_root);
if (r)
return r;
clear_bit(b, (unsigned long *) &info->current_bits);
info->dirty = true;
return 0;
}
EXPORT_SYMBOL_GPL(dm_bitset_clear_bit);
int dm_bitset_test_bit(struct dm_disk_bitset *info, dm_block_t root,
uint32_t index, dm_block_t *new_root, bool *result)
{
int r;
unsigned int b = index % BITS_PER_ARRAY_ENTRY;
r = get_array_entry(info, root, index, new_root);
if (r)
return r;
*result = test_bit(b, (unsigned long *) &info->current_bits);
return 0;
}
EXPORT_SYMBOL_GPL(dm_bitset_test_bit);
static int cursor_next_array_entry(struct dm_bitset_cursor *c)
{
int r;
__le64 *value;
r = dm_array_cursor_next(&c->cursor);
if (r)
return r;
dm_array_cursor_get_value(&c->cursor, (void **) &value);
c->array_index++;
c->bit_index = 0;
c->current_bits = le64_to_cpu(*value);
return 0;
}
int dm_bitset_cursor_begin(struct dm_disk_bitset *info,
dm_block_t root, uint32_t nr_entries,
struct dm_bitset_cursor *c)
{
int r;
__le64 *value;
if (!nr_entries)
return -ENODATA;
c->info = info;
c->entries_remaining = nr_entries;
r = dm_array_cursor_begin(&info->array_info, root, &c->cursor);
if (r)
return r;
dm_array_cursor_get_value(&c->cursor, (void **) &value);
c->array_index = 0;
c->bit_index = 0;
c->current_bits = le64_to_cpu(*value);
return r;
}
EXPORT_SYMBOL_GPL(dm_bitset_cursor_begin);
void dm_bitset_cursor_end(struct dm_bitset_cursor *c)
{
return dm_array_cursor_end(&c->cursor);
}
EXPORT_SYMBOL_GPL(dm_bitset_cursor_end);
int dm_bitset_cursor_next(struct dm_bitset_cursor *c)
{
int r = 0;
if (!c->entries_remaining)
return -ENODATA;
c->entries_remaining--;
if (++c->bit_index > 63)
r = cursor_next_array_entry(c);
return r;
}
EXPORT_SYMBOL_GPL(dm_bitset_cursor_next);
int dm_bitset_cursor_skip(struct dm_bitset_cursor *c, uint32_t count)
{
int r;
__le64 *value;
uint32_t nr_array_skip;
uint32_t remaining_in_word = 64 - c->bit_index;
if (c->entries_remaining < count)
return -ENODATA;
if (count < remaining_in_word) {
c->bit_index += count;
c->entries_remaining -= count;
return 0;
} else {
c->entries_remaining -= remaining_in_word;
count -= remaining_in_word;
}
nr_array_skip = (count / 64) + 1;
r = dm_array_cursor_skip(&c->cursor, nr_array_skip);
if (r)
return r;
dm_array_cursor_get_value(&c->cursor, (void **) &value);
c->entries_remaining -= count;
c->array_index += nr_array_skip;
c->bit_index = count & 63;
c->current_bits = le64_to_cpu(*value);
return 0;
}
EXPORT_SYMBOL_GPL(dm_bitset_cursor_skip);
bool dm_bitset_cursor_get_value(struct dm_bitset_cursor *c)
{
return test_bit(c->bit_index, (unsigned long *) &c->current_bits);
}
EXPORT_SYMBOL_GPL(dm_bitset_cursor_get_value);
/*----------------------------------------------------------------*/
| linux-master | drivers/md/persistent-data/dm-bitset.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2011 Red Hat, Inc.
*
* This file is released under the GPL.
*/
#include "dm-space-map-common.h"
#include "dm-space-map-disk.h"
#include "dm-space-map.h"
#include "dm-transaction-manager.h"
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <linux/device-mapper.h>
#define DM_MSG_PREFIX "space map disk"
/*----------------------------------------------------------------*/
/*
* Space map interface.
*/
struct sm_disk {
struct dm_space_map sm;
struct ll_disk ll;
struct ll_disk old_ll;
dm_block_t begin;
dm_block_t nr_allocated_this_transaction;
};
static void sm_disk_destroy(struct dm_space_map *sm)
{
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
kfree(smd);
}
static int sm_disk_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
{
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
return sm_ll_extend(&smd->ll, extra_blocks);
}
static int sm_disk_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count)
{
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
*count = smd->old_ll.nr_blocks;
return 0;
}
static int sm_disk_get_nr_free(struct dm_space_map *sm, dm_block_t *count)
{
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
*count = (smd->old_ll.nr_blocks - smd->old_ll.nr_allocated) - smd->nr_allocated_this_transaction;
return 0;
}
static int sm_disk_get_count(struct dm_space_map *sm, dm_block_t b,
uint32_t *result)
{
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
return sm_ll_lookup(&smd->ll, b, result);
}
static int sm_disk_count_is_more_than_one(struct dm_space_map *sm, dm_block_t b,
int *result)
{
int r;
uint32_t count;
r = sm_disk_get_count(sm, b, &count);
if (r)
return r;
*result = count > 1;
return 0;
}
static int sm_disk_set_count(struct dm_space_map *sm, dm_block_t b,
uint32_t count)
{
int r;
int32_t nr_allocations;
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
r = sm_ll_insert(&smd->ll, b, count, &nr_allocations);
if (!r)
smd->nr_allocated_this_transaction += nr_allocations;
return r;
}
static int sm_disk_inc_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e)
{
int r;
int32_t nr_allocations;
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
r = sm_ll_inc(&smd->ll, b, e, &nr_allocations);
if (!r)
smd->nr_allocated_this_transaction += nr_allocations;
return r;
}
static int sm_disk_dec_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e)
{
int r;
int32_t nr_allocations;
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
r = sm_ll_dec(&smd->ll, b, e, &nr_allocations);
if (!r)
smd->nr_allocated_this_transaction += nr_allocations;
return r;
}
static int sm_disk_new_block(struct dm_space_map *sm, dm_block_t *b)
{
int r;
int32_t nr_allocations;
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
/*
* Any block we allocate has to be free in both the old and current ll.
*/
r = sm_ll_find_common_free_block(&smd->old_ll, &smd->ll, smd->begin, smd->ll.nr_blocks, b);
if (r == -ENOSPC)
/*
* There's no free block between smd->begin and the end of the metadata device.
* We search before smd->begin in case something has been freed.
*/
r = sm_ll_find_common_free_block(&smd->old_ll, &smd->ll, 0, smd->begin, b);
if (r)
return r;
smd->begin = *b + 1;
r = sm_ll_inc(&smd->ll, *b, *b + 1, &nr_allocations);
if (!r)
smd->nr_allocated_this_transaction += nr_allocations;
return r;
}
static int sm_disk_commit(struct dm_space_map *sm)
{
int r;
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
r = sm_ll_commit(&smd->ll);
if (r)
return r;
memcpy(&smd->old_ll, &smd->ll, sizeof(smd->old_ll));
smd->nr_allocated_this_transaction = 0;
return 0;
}
static int sm_disk_root_size(struct dm_space_map *sm, size_t *result)
{
*result = sizeof(struct disk_sm_root);
return 0;
}
static int sm_disk_copy_root(struct dm_space_map *sm, void *where_le, size_t max)
{
struct sm_disk *smd = container_of(sm, struct sm_disk, sm);
struct disk_sm_root root_le;
root_le.nr_blocks = cpu_to_le64(smd->ll.nr_blocks);
root_le.nr_allocated = cpu_to_le64(smd->ll.nr_allocated);
root_le.bitmap_root = cpu_to_le64(smd->ll.bitmap_root);
root_le.ref_count_root = cpu_to_le64(smd->ll.ref_count_root);
if (max < sizeof(root_le))
return -ENOSPC;
memcpy(where_le, &root_le, sizeof(root_le));
return 0;
}
/*----------------------------------------------------------------*/
static struct dm_space_map ops = {
.destroy = sm_disk_destroy,
.extend = sm_disk_extend,
.get_nr_blocks = sm_disk_get_nr_blocks,
.get_nr_free = sm_disk_get_nr_free,
.get_count = sm_disk_get_count,
.count_is_more_than_one = sm_disk_count_is_more_than_one,
.set_count = sm_disk_set_count,
.inc_blocks = sm_disk_inc_blocks,
.dec_blocks = sm_disk_dec_blocks,
.new_block = sm_disk_new_block,
.commit = sm_disk_commit,
.root_size = sm_disk_root_size,
.copy_root = sm_disk_copy_root,
.register_threshold_callback = NULL
};
struct dm_space_map *dm_sm_disk_create(struct dm_transaction_manager *tm,
dm_block_t nr_blocks)
{
int r;
struct sm_disk *smd;
smd = kmalloc(sizeof(*smd), GFP_KERNEL);
if (!smd)
return ERR_PTR(-ENOMEM);
smd->begin = 0;
smd->nr_allocated_this_transaction = 0;
memcpy(&smd->sm, &ops, sizeof(smd->sm));
r = sm_ll_new_disk(&smd->ll, tm);
if (r)
goto bad;
r = sm_ll_extend(&smd->ll, nr_blocks);
if (r)
goto bad;
r = sm_disk_commit(&smd->sm);
if (r)
goto bad;
return &smd->sm;
bad:
kfree(smd);
return ERR_PTR(r);
}
EXPORT_SYMBOL_GPL(dm_sm_disk_create);
struct dm_space_map *dm_sm_disk_open(struct dm_transaction_manager *tm,
void *root_le, size_t len)
{
int r;
struct sm_disk *smd;
smd = kmalloc(sizeof(*smd), GFP_KERNEL);
if (!smd)
return ERR_PTR(-ENOMEM);
smd->begin = 0;
smd->nr_allocated_this_transaction = 0;
memcpy(&smd->sm, &ops, sizeof(smd->sm));
r = sm_ll_open_disk(&smd->ll, tm, root_le, len);
if (r)
goto bad;
r = sm_disk_commit(&smd->sm);
if (r)
goto bad;
return &smd->sm;
bad:
kfree(smd);
return ERR_PTR(r);
}
EXPORT_SYMBOL_GPL(dm_sm_disk_open);
/*----------------------------------------------------------------*/
| linux-master | drivers/md/persistent-data/dm-space-map-disk.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2011 Red Hat, Inc.
*
* This file is released under the GPL.
*/
#include "dm-btree-internal.h"
#include "dm-space-map.h"
#include "dm-transaction-manager.h"
#include <linux/export.h>
#include <linux/device-mapper.h>
#define DM_MSG_PREFIX "btree"
/*
*--------------------------------------------------------------
* Array manipulation
*--------------------------------------------------------------
*/
static void memcpy_disk(void *dest, const void *src, size_t len)
__dm_written_to_disk(src)
{
memcpy(dest, src, len);
__dm_unbless_for_disk(src);
}
static void array_insert(void *base, size_t elt_size, unsigned int nr_elts,
unsigned int index, void *elt)
__dm_written_to_disk(elt)
{
if (index < nr_elts)
memmove(base + (elt_size * (index + 1)),
base + (elt_size * index),
(nr_elts - index) * elt_size);
memcpy_disk(base + (elt_size * index), elt, elt_size);
}
/*----------------------------------------------------------------*/
/* makes the assumption that no two keys are the same. */
static int bsearch(struct btree_node *n, uint64_t key, int want_hi)
{
int lo = -1, hi = le32_to_cpu(n->header.nr_entries);
while (hi - lo > 1) {
int mid = lo + ((hi - lo) / 2);
uint64_t mid_key = le64_to_cpu(n->keys[mid]);
if (mid_key == key)
return mid;
if (mid_key < key)
lo = mid;
else
hi = mid;
}
return want_hi ? hi : lo;
}
int lower_bound(struct btree_node *n, uint64_t key)
{
return bsearch(n, key, 0);
}
static int upper_bound(struct btree_node *n, uint64_t key)
{
return bsearch(n, key, 1);
}
void inc_children(struct dm_transaction_manager *tm, struct btree_node *n,
struct dm_btree_value_type *vt)
{
uint32_t nr_entries = le32_to_cpu(n->header.nr_entries);
if (le32_to_cpu(n->header.flags) & INTERNAL_NODE)
dm_tm_with_runs(tm, value_ptr(n, 0), nr_entries, dm_tm_inc_range);
else if (vt->inc)
vt->inc(vt->context, value_ptr(n, 0), nr_entries);
}
static int insert_at(size_t value_size, struct btree_node *node, unsigned int index,
uint64_t key, void *value)
__dm_written_to_disk(value)
{
uint32_t nr_entries = le32_to_cpu(node->header.nr_entries);
uint32_t max_entries = le32_to_cpu(node->header.max_entries);
__le64 key_le = cpu_to_le64(key);
if (index > nr_entries ||
index >= max_entries ||
nr_entries >= max_entries) {
DMERR("too many entries in btree node for insert");
__dm_unbless_for_disk(value);
return -ENOMEM;
}
__dm_bless_for_disk(&key_le);
array_insert(node->keys, sizeof(*node->keys), nr_entries, index, &key_le);
array_insert(value_base(node), value_size, nr_entries, index, value);
node->header.nr_entries = cpu_to_le32(nr_entries + 1);
return 0;
}
/*----------------------------------------------------------------*/
/*
* We want 3n entries (for some n). This works more nicely for repeated
* insert remove loops than (2n + 1).
*/
static uint32_t calc_max_entries(size_t value_size, size_t block_size)
{
uint32_t total, n;
size_t elt_size = sizeof(uint64_t) + value_size; /* key + value */
block_size -= sizeof(struct node_header);
total = block_size / elt_size;
n = total / 3; /* rounds down */
return 3 * n;
}
int dm_btree_empty(struct dm_btree_info *info, dm_block_t *root)
{
int r;
struct dm_block *b;
struct btree_node *n;
size_t block_size;
uint32_t max_entries;
r = new_block(info, &b);
if (r < 0)
return r;
block_size = dm_bm_block_size(dm_tm_get_bm(info->tm));
max_entries = calc_max_entries(info->value_type.size, block_size);
n = dm_block_data(b);
memset(n, 0, block_size);
n->header.flags = cpu_to_le32(LEAF_NODE);
n->header.nr_entries = cpu_to_le32(0);
n->header.max_entries = cpu_to_le32(max_entries);
n->header.value_size = cpu_to_le32(info->value_type.size);
*root = dm_block_location(b);
unlock_block(info, b);
return 0;
}
EXPORT_SYMBOL_GPL(dm_btree_empty);
/*----------------------------------------------------------------*/
/*
* Deletion uses a recursive algorithm, since we have limited stack space
* we explicitly manage our own stack on the heap.
*/
#define MAX_SPINE_DEPTH 64
struct frame {
struct dm_block *b;
struct btree_node *n;
unsigned int level;
unsigned int nr_children;
unsigned int current_child;
};
struct del_stack {
struct dm_btree_info *info;
struct dm_transaction_manager *tm;
int top;
struct frame spine[MAX_SPINE_DEPTH];
};
static int top_frame(struct del_stack *s, struct frame **f)
{
if (s->top < 0) {
DMERR("btree deletion stack empty");
return -EINVAL;
}
*f = s->spine + s->top;
return 0;
}
static int unprocessed_frames(struct del_stack *s)
{
return s->top >= 0;
}
static void prefetch_children(struct del_stack *s, struct frame *f)
{
unsigned int i;
struct dm_block_manager *bm = dm_tm_get_bm(s->tm);
for (i = 0; i < f->nr_children; i++)
dm_bm_prefetch(bm, value64(f->n, i));
}
static bool is_internal_level(struct dm_btree_info *info, struct frame *f)
{
return f->level < (info->levels - 1);
}
static int push_frame(struct del_stack *s, dm_block_t b, unsigned int level)
{
int r;
uint32_t ref_count;
if (s->top >= MAX_SPINE_DEPTH - 1) {
DMERR("btree deletion stack out of memory");
return -ENOMEM;
}
r = dm_tm_ref(s->tm, b, &ref_count);
if (r)
return r;
if (ref_count > 1)
/*
* This is a shared node, so we can just decrement it's
* reference counter and leave the children.
*/
dm_tm_dec(s->tm, b);
else {
uint32_t flags;
struct frame *f = s->spine + ++s->top;
r = dm_tm_read_lock(s->tm, b, &btree_node_validator, &f->b);
if (r) {
s->top--;
return r;
}
f->n = dm_block_data(f->b);
f->level = level;
f->nr_children = le32_to_cpu(f->n->header.nr_entries);
f->current_child = 0;
flags = le32_to_cpu(f->n->header.flags);
if (flags & INTERNAL_NODE || is_internal_level(s->info, f))
prefetch_children(s, f);
}
return 0;
}
static void pop_frame(struct del_stack *s)
{
struct frame *f = s->spine + s->top--;
dm_tm_dec(s->tm, dm_block_location(f->b));
dm_tm_unlock(s->tm, f->b);
}
static void unlock_all_frames(struct del_stack *s)
{
struct frame *f;
while (unprocessed_frames(s)) {
f = s->spine + s->top--;
dm_tm_unlock(s->tm, f->b);
}
}
int dm_btree_del(struct dm_btree_info *info, dm_block_t root)
{
int r;
struct del_stack *s;
/*
* dm_btree_del() is called via an ioctl, as such should be
* considered an FS op. We can't recurse back into the FS, so we
* allocate GFP_NOFS.
*/
s = kmalloc(sizeof(*s), GFP_NOFS);
if (!s)
return -ENOMEM;
s->info = info;
s->tm = info->tm;
s->top = -1;
r = push_frame(s, root, 0);
if (r)
goto out;
while (unprocessed_frames(s)) {
uint32_t flags;
struct frame *f;
dm_block_t b;
r = top_frame(s, &f);
if (r)
goto out;
if (f->current_child >= f->nr_children) {
pop_frame(s);
continue;
}
flags = le32_to_cpu(f->n->header.flags);
if (flags & INTERNAL_NODE) {
b = value64(f->n, f->current_child);
f->current_child++;
r = push_frame(s, b, f->level);
if (r)
goto out;
} else if (is_internal_level(info, f)) {
b = value64(f->n, f->current_child);
f->current_child++;
r = push_frame(s, b, f->level + 1);
if (r)
goto out;
} else {
if (info->value_type.dec)
info->value_type.dec(info->value_type.context,
value_ptr(f->n, 0), f->nr_children);
pop_frame(s);
}
}
out:
if (r) {
/* cleanup all frames of del_stack */
unlock_all_frames(s);
}
kfree(s);
return r;
}
EXPORT_SYMBOL_GPL(dm_btree_del);
/*----------------------------------------------------------------*/
static int btree_lookup_raw(struct ro_spine *s, dm_block_t block, uint64_t key,
int (*search_fn)(struct btree_node *, uint64_t),
uint64_t *result_key, void *v, size_t value_size)
{
int i, r;
uint32_t flags, nr_entries;
do {
r = ro_step(s, block);
if (r < 0)
return r;
i = search_fn(ro_node(s), key);
flags = le32_to_cpu(ro_node(s)->header.flags);
nr_entries = le32_to_cpu(ro_node(s)->header.nr_entries);
if (i < 0 || i >= nr_entries)
return -ENODATA;
if (flags & INTERNAL_NODE)
block = value64(ro_node(s), i);
} while (!(flags & LEAF_NODE));
*result_key = le64_to_cpu(ro_node(s)->keys[i]);
if (v)
memcpy(v, value_ptr(ro_node(s), i), value_size);
return 0;
}
int dm_btree_lookup(struct dm_btree_info *info, dm_block_t root,
uint64_t *keys, void *value_le)
{
unsigned int level, last_level = info->levels - 1;
int r = -ENODATA;
uint64_t rkey;
__le64 internal_value_le;
struct ro_spine spine;
init_ro_spine(&spine, info);
for (level = 0; level < info->levels; level++) {
size_t size;
void *value_p;
if (level == last_level) {
value_p = value_le;
size = info->value_type.size;
} else {
value_p = &internal_value_le;
size = sizeof(uint64_t);
}
r = btree_lookup_raw(&spine, root, keys[level],
lower_bound, &rkey,
value_p, size);
if (!r) {
if (rkey != keys[level]) {
exit_ro_spine(&spine);
return -ENODATA;
}
} else {
exit_ro_spine(&spine);
return r;
}
root = le64_to_cpu(internal_value_le);
}
exit_ro_spine(&spine);
return r;
}
EXPORT_SYMBOL_GPL(dm_btree_lookup);
static int dm_btree_lookup_next_single(struct dm_btree_info *info, dm_block_t root,
uint64_t key, uint64_t *rkey, void *value_le)
{
int r, i;
uint32_t flags, nr_entries;
struct dm_block *node;
struct btree_node *n;
r = bn_read_lock(info, root, &node);
if (r)
return r;
n = dm_block_data(node);
flags = le32_to_cpu(n->header.flags);
nr_entries = le32_to_cpu(n->header.nr_entries);
if (flags & INTERNAL_NODE) {
i = lower_bound(n, key);
if (i < 0) {
/*
* avoid early -ENODATA return when all entries are
* higher than the search @key.
*/
i = 0;
}
if (i >= nr_entries) {
r = -ENODATA;
goto out;
}
r = dm_btree_lookup_next_single(info, value64(n, i), key, rkey, value_le);
if (r == -ENODATA && i < (nr_entries - 1)) {
i++;
r = dm_btree_lookup_next_single(info, value64(n, i), key, rkey, value_le);
}
} else {
i = upper_bound(n, key);
if (i < 0 || i >= nr_entries) {
r = -ENODATA;
goto out;
}
*rkey = le64_to_cpu(n->keys[i]);
memcpy(value_le, value_ptr(n, i), info->value_type.size);
}
out:
dm_tm_unlock(info->tm, node);
return r;
}
int dm_btree_lookup_next(struct dm_btree_info *info, dm_block_t root,
uint64_t *keys, uint64_t *rkey, void *value_le)
{
unsigned int level;
int r = -ENODATA;
__le64 internal_value_le;
struct ro_spine spine;
init_ro_spine(&spine, info);
for (level = 0; level < info->levels - 1u; level++) {
r = btree_lookup_raw(&spine, root, keys[level],
lower_bound, rkey,
&internal_value_le, sizeof(uint64_t));
if (r)
goto out;
if (*rkey != keys[level]) {
r = -ENODATA;
goto out;
}
root = le64_to_cpu(internal_value_le);
}
r = dm_btree_lookup_next_single(info, root, keys[level], rkey, value_le);
out:
exit_ro_spine(&spine);
return r;
}
EXPORT_SYMBOL_GPL(dm_btree_lookup_next);
/*----------------------------------------------------------------*/
/*
* Copies entries from one region of a btree node to another. The regions
* must not overlap.
*/
static void copy_entries(struct btree_node *dest, unsigned int dest_offset,
struct btree_node *src, unsigned int src_offset,
unsigned int count)
{
size_t value_size = le32_to_cpu(dest->header.value_size);
memcpy(dest->keys + dest_offset, src->keys + src_offset, count * sizeof(uint64_t));
memcpy(value_ptr(dest, dest_offset), value_ptr(src, src_offset), count * value_size);
}
/*
* Moves entries from one region fo a btree node to another. The regions
* may overlap.
*/
static void move_entries(struct btree_node *dest, unsigned int dest_offset,
struct btree_node *src, unsigned int src_offset,
unsigned int count)
{
size_t value_size = le32_to_cpu(dest->header.value_size);
memmove(dest->keys + dest_offset, src->keys + src_offset, count * sizeof(uint64_t));
memmove(value_ptr(dest, dest_offset), value_ptr(src, src_offset), count * value_size);
}
/*
* Erases the first 'count' entries of a btree node, shifting following
* entries down into their place.
*/
static void shift_down(struct btree_node *n, unsigned int count)
{
move_entries(n, 0, n, count, le32_to_cpu(n->header.nr_entries) - count);
}
/*
* Moves entries in a btree node up 'count' places, making space for
* new entries at the start of the node.
*/
static void shift_up(struct btree_node *n, unsigned int count)
{
move_entries(n, count, n, 0, le32_to_cpu(n->header.nr_entries));
}
/*
* Redistributes entries between two btree nodes to make them
* have similar numbers of entries.
*/
static void redistribute2(struct btree_node *left, struct btree_node *right)
{
unsigned int nr_left = le32_to_cpu(left->header.nr_entries);
unsigned int nr_right = le32_to_cpu(right->header.nr_entries);
unsigned int total = nr_left + nr_right;
unsigned int target_left = total / 2;
unsigned int target_right = total - target_left;
if (nr_left < target_left) {
unsigned int delta = target_left - nr_left;
copy_entries(left, nr_left, right, 0, delta);
shift_down(right, delta);
} else if (nr_left > target_left) {
unsigned int delta = nr_left - target_left;
if (nr_right)
shift_up(right, delta);
copy_entries(right, 0, left, target_left, delta);
}
left->header.nr_entries = cpu_to_le32(target_left);
right->header.nr_entries = cpu_to_le32(target_right);
}
/*
* Redistribute entries between three nodes. Assumes the central
* node is empty.
*/
static void redistribute3(struct btree_node *left, struct btree_node *center,
struct btree_node *right)
{
unsigned int nr_left = le32_to_cpu(left->header.nr_entries);
unsigned int nr_center = le32_to_cpu(center->header.nr_entries);
unsigned int nr_right = le32_to_cpu(right->header.nr_entries);
unsigned int total, target_left, target_center, target_right;
BUG_ON(nr_center);
total = nr_left + nr_right;
target_left = total / 3;
target_center = (total - target_left) / 2;
target_right = (total - target_left - target_center);
if (nr_left < target_left) {
unsigned int left_short = target_left - nr_left;
copy_entries(left, nr_left, right, 0, left_short);
copy_entries(center, 0, right, left_short, target_center);
shift_down(right, nr_right - target_right);
} else if (nr_left < (target_left + target_center)) {
unsigned int left_to_center = nr_left - target_left;
copy_entries(center, 0, left, target_left, left_to_center);
copy_entries(center, left_to_center, right, 0, target_center - left_to_center);
shift_down(right, nr_right - target_right);
} else {
unsigned int right_short = target_right - nr_right;
shift_up(right, right_short);
copy_entries(right, 0, left, nr_left - right_short, right_short);
copy_entries(center, 0, left, target_left, nr_left - target_left);
}
left->header.nr_entries = cpu_to_le32(target_left);
center->header.nr_entries = cpu_to_le32(target_center);
right->header.nr_entries = cpu_to_le32(target_right);
}
/*
* Splits a node by creating a sibling node and shifting half the nodes
* contents across. Assumes there is a parent node, and it has room for
* another child.
*
* Before:
* +--------+
* | Parent |
* +--------+
* |
* v
* +----------+
* | A ++++++ |
* +----------+
*
*
* After:
* +--------+
* | Parent |
* +--------+
* | |
* v +------+
* +---------+ |
* | A* +++ | v
* +---------+ +-------+
* | B +++ |
* +-------+
*
* Where A* is a shadow of A.
*/
static int split_one_into_two(struct shadow_spine *s, unsigned int parent_index,
struct dm_btree_value_type *vt, uint64_t key)
{
int r;
struct dm_block *left, *right, *parent;
struct btree_node *ln, *rn, *pn;
__le64 location;
left = shadow_current(s);
r = new_block(s->info, &right);
if (r < 0)
return r;
ln = dm_block_data(left);
rn = dm_block_data(right);
rn->header.flags = ln->header.flags;
rn->header.nr_entries = cpu_to_le32(0);
rn->header.max_entries = ln->header.max_entries;
rn->header.value_size = ln->header.value_size;
redistribute2(ln, rn);
/* patch up the parent */
parent = shadow_parent(s);
pn = dm_block_data(parent);
location = cpu_to_le64(dm_block_location(right));
__dm_bless_for_disk(&location);
r = insert_at(sizeof(__le64), pn, parent_index + 1,
le64_to_cpu(rn->keys[0]), &location);
if (r) {
unlock_block(s->info, right);
return r;
}
/* patch up the spine */
if (key < le64_to_cpu(rn->keys[0])) {
unlock_block(s->info, right);
s->nodes[1] = left;
} else {
unlock_block(s->info, left);
s->nodes[1] = right;
}
return 0;
}
/*
* We often need to modify a sibling node. This function shadows a particular
* child of the given parent node. Making sure to update the parent to point
* to the new shadow.
*/
static int shadow_child(struct dm_btree_info *info, struct dm_btree_value_type *vt,
struct btree_node *parent, unsigned int index,
struct dm_block **result)
{
int r, inc;
dm_block_t root;
struct btree_node *node;
root = value64(parent, index);
r = dm_tm_shadow_block(info->tm, root, &btree_node_validator,
result, &inc);
if (r)
return r;
node = dm_block_data(*result);
if (inc)
inc_children(info->tm, node, vt);
*((__le64 *) value_ptr(parent, index)) =
cpu_to_le64(dm_block_location(*result));
return 0;
}
/*
* Splits two nodes into three. This is more work, but results in fuller
* nodes, so saves metadata space.
*/
static int split_two_into_three(struct shadow_spine *s, unsigned int parent_index,
struct dm_btree_value_type *vt, uint64_t key)
{
int r;
unsigned int middle_index;
struct dm_block *left, *middle, *right, *parent;
struct btree_node *ln, *rn, *mn, *pn;
__le64 location;
parent = shadow_parent(s);
pn = dm_block_data(parent);
if (parent_index == 0) {
middle_index = 1;
left = shadow_current(s);
r = shadow_child(s->info, vt, pn, parent_index + 1, &right);
if (r)
return r;
} else {
middle_index = parent_index;
right = shadow_current(s);
r = shadow_child(s->info, vt, pn, parent_index - 1, &left);
if (r)
return r;
}
r = new_block(s->info, &middle);
if (r < 0)
return r;
ln = dm_block_data(left);
mn = dm_block_data(middle);
rn = dm_block_data(right);
mn->header.nr_entries = cpu_to_le32(0);
mn->header.flags = ln->header.flags;
mn->header.max_entries = ln->header.max_entries;
mn->header.value_size = ln->header.value_size;
redistribute3(ln, mn, rn);
/* patch up the parent */
pn->keys[middle_index] = rn->keys[0];
location = cpu_to_le64(dm_block_location(middle));
__dm_bless_for_disk(&location);
r = insert_at(sizeof(__le64), pn, middle_index,
le64_to_cpu(mn->keys[0]), &location);
if (r) {
if (shadow_current(s) != left)
unlock_block(s->info, left);
unlock_block(s->info, middle);
if (shadow_current(s) != right)
unlock_block(s->info, right);
return r;
}
/* patch up the spine */
if (key < le64_to_cpu(mn->keys[0])) {
unlock_block(s->info, middle);
unlock_block(s->info, right);
s->nodes[1] = left;
} else if (key < le64_to_cpu(rn->keys[0])) {
unlock_block(s->info, left);
unlock_block(s->info, right);
s->nodes[1] = middle;
} else {
unlock_block(s->info, left);
unlock_block(s->info, middle);
s->nodes[1] = right;
}
return 0;
}
/*----------------------------------------------------------------*/
/*
* Splits a node by creating two new children beneath the given node.
*
* Before:
* +----------+
* | A ++++++ |
* +----------+
*
*
* After:
* +------------+
* | A (shadow) |
* +------------+
* | |
* +------+ +----+
* | |
* v v
* +-------+ +-------+
* | B +++ | | C +++ |
* +-------+ +-------+
*/
static int btree_split_beneath(struct shadow_spine *s, uint64_t key)
{
int r;
size_t size;
unsigned int nr_left, nr_right;
struct dm_block *left, *right, *new_parent;
struct btree_node *pn, *ln, *rn;
__le64 val;
new_parent = shadow_current(s);
pn = dm_block_data(new_parent);
size = le32_to_cpu(pn->header.flags) & INTERNAL_NODE ?
sizeof(__le64) : s->info->value_type.size;
/* create & init the left block */
r = new_block(s->info, &left);
if (r < 0)
return r;
ln = dm_block_data(left);
nr_left = le32_to_cpu(pn->header.nr_entries) / 2;
ln->header.flags = pn->header.flags;
ln->header.nr_entries = cpu_to_le32(nr_left);
ln->header.max_entries = pn->header.max_entries;
ln->header.value_size = pn->header.value_size;
memcpy(ln->keys, pn->keys, nr_left * sizeof(pn->keys[0]));
memcpy(value_ptr(ln, 0), value_ptr(pn, 0), nr_left * size);
/* create & init the right block */
r = new_block(s->info, &right);
if (r < 0) {
unlock_block(s->info, left);
return r;
}
rn = dm_block_data(right);
nr_right = le32_to_cpu(pn->header.nr_entries) - nr_left;
rn->header.flags = pn->header.flags;
rn->header.nr_entries = cpu_to_le32(nr_right);
rn->header.max_entries = pn->header.max_entries;
rn->header.value_size = pn->header.value_size;
memcpy(rn->keys, pn->keys + nr_left, nr_right * sizeof(pn->keys[0]));
memcpy(value_ptr(rn, 0), value_ptr(pn, nr_left),
nr_right * size);
/* new_parent should just point to l and r now */
pn->header.flags = cpu_to_le32(INTERNAL_NODE);
pn->header.nr_entries = cpu_to_le32(2);
pn->header.max_entries = cpu_to_le32(
calc_max_entries(sizeof(__le64),
dm_bm_block_size(
dm_tm_get_bm(s->info->tm))));
pn->header.value_size = cpu_to_le32(sizeof(__le64));
val = cpu_to_le64(dm_block_location(left));
__dm_bless_for_disk(&val);
pn->keys[0] = ln->keys[0];
memcpy_disk(value_ptr(pn, 0), &val, sizeof(__le64));
val = cpu_to_le64(dm_block_location(right));
__dm_bless_for_disk(&val);
pn->keys[1] = rn->keys[0];
memcpy_disk(value_ptr(pn, 1), &val, sizeof(__le64));
unlock_block(s->info, left);
unlock_block(s->info, right);
return 0;
}
/*----------------------------------------------------------------*/
/*
* Redistributes a node's entries with its left sibling.
*/
static int rebalance_left(struct shadow_spine *s, struct dm_btree_value_type *vt,
unsigned int parent_index, uint64_t key)
{
int r;
struct dm_block *sib;
struct btree_node *left, *right, *parent = dm_block_data(shadow_parent(s));
r = shadow_child(s->info, vt, parent, parent_index - 1, &sib);
if (r)
return r;
left = dm_block_data(sib);
right = dm_block_data(shadow_current(s));
redistribute2(left, right);
*key_ptr(parent, parent_index) = right->keys[0];
if (key < le64_to_cpu(right->keys[0])) {
unlock_block(s->info, s->nodes[1]);
s->nodes[1] = sib;
} else {
unlock_block(s->info, sib);
}
return 0;
}
/*
* Redistributes a nodes entries with its right sibling.
*/
static int rebalance_right(struct shadow_spine *s, struct dm_btree_value_type *vt,
unsigned int parent_index, uint64_t key)
{
int r;
struct dm_block *sib;
struct btree_node *left, *right, *parent = dm_block_data(shadow_parent(s));
r = shadow_child(s->info, vt, parent, parent_index + 1, &sib);
if (r)
return r;
left = dm_block_data(shadow_current(s));
right = dm_block_data(sib);
redistribute2(left, right);
*key_ptr(parent, parent_index + 1) = right->keys[0];
if (key < le64_to_cpu(right->keys[0])) {
unlock_block(s->info, sib);
} else {
unlock_block(s->info, s->nodes[1]);
s->nodes[1] = sib;
}
return 0;
}
/*
* Returns the number of spare entries in a node.
*/
static int get_node_free_space(struct dm_btree_info *info, dm_block_t b, unsigned int *space)
{
int r;
unsigned int nr_entries;
struct dm_block *block;
struct btree_node *node;
r = bn_read_lock(info, b, &block);
if (r)
return r;
node = dm_block_data(block);
nr_entries = le32_to_cpu(node->header.nr_entries);
*space = le32_to_cpu(node->header.max_entries) - nr_entries;
unlock_block(info, block);
return 0;
}
/*
* Make space in a node, either by moving some entries to a sibling,
* or creating a new sibling node. SPACE_THRESHOLD defines the minimum
* number of free entries that must be in the sibling to make the move
* worth while. If the siblings are shared (eg, part of a snapshot),
* then they are not touched, since this break sharing and so consume
* more space than we save.
*/
#define SPACE_THRESHOLD 8
static int rebalance_or_split(struct shadow_spine *s, struct dm_btree_value_type *vt,
unsigned int parent_index, uint64_t key)
{
int r;
struct btree_node *parent = dm_block_data(shadow_parent(s));
unsigned int nr_parent = le32_to_cpu(parent->header.nr_entries);
unsigned int free_space;
int left_shared = 0, right_shared = 0;
/* Should we move entries to the left sibling? */
if (parent_index > 0) {
dm_block_t left_b = value64(parent, parent_index - 1);
r = dm_tm_block_is_shared(s->info->tm, left_b, &left_shared);
if (r)
return r;
if (!left_shared) {
r = get_node_free_space(s->info, left_b, &free_space);
if (r)
return r;
if (free_space >= SPACE_THRESHOLD)
return rebalance_left(s, vt, parent_index, key);
}
}
/* Should we move entries to the right sibling? */
if (parent_index < (nr_parent - 1)) {
dm_block_t right_b = value64(parent, parent_index + 1);
r = dm_tm_block_is_shared(s->info->tm, right_b, &right_shared);
if (r)
return r;
if (!right_shared) {
r = get_node_free_space(s->info, right_b, &free_space);
if (r)
return r;
if (free_space >= SPACE_THRESHOLD)
return rebalance_right(s, vt, parent_index, key);
}
}
/*
* We need to split the node, normally we split two nodes
* into three. But when inserting a sequence that is either
* monotonically increasing or decreasing it's better to split
* a single node into two.
*/
if (left_shared || right_shared || (nr_parent <= 2) ||
(parent_index == 0) || (parent_index + 1 == nr_parent)) {
return split_one_into_two(s, parent_index, vt, key);
} else {
return split_two_into_three(s, parent_index, vt, key);
}
}
/*
* Does the node contain a particular key?
*/
static bool contains_key(struct btree_node *node, uint64_t key)
{
int i = lower_bound(node, key);
if (i >= 0 && le64_to_cpu(node->keys[i]) == key)
return true;
return false;
}
/*
* In general we preemptively make sure there's a free entry in every
* node on the spine when doing an insert. But we can avoid that with
* leaf nodes if we know it's an overwrite.
*/
static bool has_space_for_insert(struct btree_node *node, uint64_t key)
{
if (node->header.nr_entries == node->header.max_entries) {
if (le32_to_cpu(node->header.flags) & LEAF_NODE) {
/* we don't need space if it's an overwrite */
return contains_key(node, key);
}
return false;
}
return true;
}
static int btree_insert_raw(struct shadow_spine *s, dm_block_t root,
struct dm_btree_value_type *vt,
uint64_t key, unsigned int *index)
{
int r, i = *index, top = 1;
struct btree_node *node;
for (;;) {
r = shadow_step(s, root, vt);
if (r < 0)
return r;
node = dm_block_data(shadow_current(s));
/*
* We have to patch up the parent node, ugly, but I don't
* see a way to do this automatically as part of the spine
* op.
*/
if (shadow_has_parent(s) && i >= 0) { /* FIXME: second clause unness. */
__le64 location = cpu_to_le64(dm_block_location(shadow_current(s)));
__dm_bless_for_disk(&location);
memcpy_disk(value_ptr(dm_block_data(shadow_parent(s)), i),
&location, sizeof(__le64));
}
node = dm_block_data(shadow_current(s));
if (!has_space_for_insert(node, key)) {
if (top)
r = btree_split_beneath(s, key);
else
r = rebalance_or_split(s, vt, i, key);
if (r < 0)
return r;
/* making space can cause the current node to change */
node = dm_block_data(shadow_current(s));
}
i = lower_bound(node, key);
if (le32_to_cpu(node->header.flags) & LEAF_NODE)
break;
if (i < 0) {
/* change the bounds on the lowest key */
node->keys[0] = cpu_to_le64(key);
i = 0;
}
root = value64(node, i);
top = 0;
}
if (i < 0 || le64_to_cpu(node->keys[i]) != key)
i++;
*index = i;
return 0;
}
static int __btree_get_overwrite_leaf(struct shadow_spine *s, dm_block_t root,
uint64_t key, int *index)
{
int r, i = -1;
struct btree_node *node;
*index = 0;
for (;;) {
r = shadow_step(s, root, &s->info->value_type);
if (r < 0)
return r;
node = dm_block_data(shadow_current(s));
/*
* We have to patch up the parent node, ugly, but I don't
* see a way to do this automatically as part of the spine
* op.
*/
if (shadow_has_parent(s) && i >= 0) {
__le64 location = cpu_to_le64(dm_block_location(shadow_current(s)));
__dm_bless_for_disk(&location);
memcpy_disk(value_ptr(dm_block_data(shadow_parent(s)), i),
&location, sizeof(__le64));
}
node = dm_block_data(shadow_current(s));
i = lower_bound(node, key);
BUG_ON(i < 0);
BUG_ON(i >= le32_to_cpu(node->header.nr_entries));
if (le32_to_cpu(node->header.flags) & LEAF_NODE) {
if (key != le64_to_cpu(node->keys[i]))
return -EINVAL;
break;
}
root = value64(node, i);
}
*index = i;
return 0;
}
int btree_get_overwrite_leaf(struct dm_btree_info *info, dm_block_t root,
uint64_t key, int *index,
dm_block_t *new_root, struct dm_block **leaf)
{
int r;
struct shadow_spine spine;
BUG_ON(info->levels > 1);
init_shadow_spine(&spine, info);
r = __btree_get_overwrite_leaf(&spine, root, key, index);
if (!r) {
*new_root = shadow_root(&spine);
*leaf = shadow_current(&spine);
/*
* Decrement the count so exit_shadow_spine() doesn't
* unlock the leaf.
*/
spine.count--;
}
exit_shadow_spine(&spine);
return r;
}
static bool need_insert(struct btree_node *node, uint64_t *keys,
unsigned int level, unsigned int index)
{
return ((index >= le32_to_cpu(node->header.nr_entries)) ||
(le64_to_cpu(node->keys[index]) != keys[level]));
}
static int insert(struct dm_btree_info *info, dm_block_t root,
uint64_t *keys, void *value, dm_block_t *new_root,
int *inserted)
__dm_written_to_disk(value)
{
int r;
unsigned int level, index = -1, last_level = info->levels - 1;
dm_block_t block = root;
struct shadow_spine spine;
struct btree_node *n;
struct dm_btree_value_type le64_type;
init_le64_type(info->tm, &le64_type);
init_shadow_spine(&spine, info);
for (level = 0; level < (info->levels - 1); level++) {
r = btree_insert_raw(&spine, block, &le64_type, keys[level], &index);
if (r < 0)
goto bad;
n = dm_block_data(shadow_current(&spine));
if (need_insert(n, keys, level, index)) {
dm_block_t new_tree;
__le64 new_le;
r = dm_btree_empty(info, &new_tree);
if (r < 0)
goto bad;
new_le = cpu_to_le64(new_tree);
__dm_bless_for_disk(&new_le);
r = insert_at(sizeof(uint64_t), n, index,
keys[level], &new_le);
if (r)
goto bad;
}
if (level < last_level)
block = value64(n, index);
}
r = btree_insert_raw(&spine, block, &info->value_type,
keys[level], &index);
if (r < 0)
goto bad;
n = dm_block_data(shadow_current(&spine));
if (need_insert(n, keys, level, index)) {
if (inserted)
*inserted = 1;
r = insert_at(info->value_type.size, n, index,
keys[level], value);
if (r)
goto bad_unblessed;
} else {
if (inserted)
*inserted = 0;
if (info->value_type.dec &&
(!info->value_type.equal ||
!info->value_type.equal(
info->value_type.context,
value_ptr(n, index),
value))) {
info->value_type.dec(info->value_type.context,
value_ptr(n, index), 1);
}
memcpy_disk(value_ptr(n, index),
value, info->value_type.size);
}
*new_root = shadow_root(&spine);
exit_shadow_spine(&spine);
return 0;
bad:
__dm_unbless_for_disk(value);
bad_unblessed:
exit_shadow_spine(&spine);
return r;
}
int dm_btree_insert(struct dm_btree_info *info, dm_block_t root,
uint64_t *keys, void *value, dm_block_t *new_root)
__dm_written_to_disk(value)
{
return insert(info, root, keys, value, new_root, NULL);
}
EXPORT_SYMBOL_GPL(dm_btree_insert);
int dm_btree_insert_notify(struct dm_btree_info *info, dm_block_t root,
uint64_t *keys, void *value, dm_block_t *new_root,
int *inserted)
__dm_written_to_disk(value)
{
return insert(info, root, keys, value, new_root, inserted);
}
EXPORT_SYMBOL_GPL(dm_btree_insert_notify);
/*----------------------------------------------------------------*/
static int find_key(struct ro_spine *s, dm_block_t block, bool find_highest,
uint64_t *result_key, dm_block_t *next_block)
{
int i, r;
uint32_t flags;
do {
r = ro_step(s, block);
if (r < 0)
return r;
flags = le32_to_cpu(ro_node(s)->header.flags);
i = le32_to_cpu(ro_node(s)->header.nr_entries);
if (!i)
return -ENODATA;
i--;
if (find_highest)
*result_key = le64_to_cpu(ro_node(s)->keys[i]);
else
*result_key = le64_to_cpu(ro_node(s)->keys[0]);
if (next_block || flags & INTERNAL_NODE) {
if (find_highest)
block = value64(ro_node(s), i);
else
block = value64(ro_node(s), 0);
}
} while (flags & INTERNAL_NODE);
if (next_block)
*next_block = block;
return 0;
}
static int dm_btree_find_key(struct dm_btree_info *info, dm_block_t root,
bool find_highest, uint64_t *result_keys)
{
int r = 0, count = 0, level;
struct ro_spine spine;
init_ro_spine(&spine, info);
for (level = 0; level < info->levels; level++) {
r = find_key(&spine, root, find_highest, result_keys + level,
level == info->levels - 1 ? NULL : &root);
if (r == -ENODATA) {
r = 0;
break;
} else if (r)
break;
count++;
}
exit_ro_spine(&spine);
return r ? r : count;
}
int dm_btree_find_highest_key(struct dm_btree_info *info, dm_block_t root,
uint64_t *result_keys)
{
return dm_btree_find_key(info, root, true, result_keys);
}
EXPORT_SYMBOL_GPL(dm_btree_find_highest_key);
int dm_btree_find_lowest_key(struct dm_btree_info *info, dm_block_t root,
uint64_t *result_keys)
{
return dm_btree_find_key(info, root, false, result_keys);
}
EXPORT_SYMBOL_GPL(dm_btree_find_lowest_key);
/*----------------------------------------------------------------*/
/*
* FIXME: We shouldn't use a recursive algorithm when we have limited stack
* space. Also this only works for single level trees.
*/
static int walk_node(struct dm_btree_info *info, dm_block_t block,
int (*fn)(void *context, uint64_t *keys, void *leaf),
void *context)
{
int r;
unsigned int i, nr;
struct dm_block *node;
struct btree_node *n;
uint64_t keys;
r = bn_read_lock(info, block, &node);
if (r)
return r;
n = dm_block_data(node);
nr = le32_to_cpu(n->header.nr_entries);
for (i = 0; i < nr; i++) {
if (le32_to_cpu(n->header.flags) & INTERNAL_NODE) {
r = walk_node(info, value64(n, i), fn, context);
if (r)
goto out;
} else {
keys = le64_to_cpu(*key_ptr(n, i));
r = fn(context, &keys, value_ptr(n, i));
if (r)
goto out;
}
}
out:
dm_tm_unlock(info->tm, node);
return r;
}
int dm_btree_walk(struct dm_btree_info *info, dm_block_t root,
int (*fn)(void *context, uint64_t *keys, void *leaf),
void *context)
{
BUG_ON(info->levels > 1);
return walk_node(info, root, fn, context);
}
EXPORT_SYMBOL_GPL(dm_btree_walk);
/*----------------------------------------------------------------*/
static void prefetch_values(struct dm_btree_cursor *c)
{
unsigned int i, nr;
__le64 value_le;
struct cursor_node *n = c->nodes + c->depth - 1;
struct btree_node *bn = dm_block_data(n->b);
struct dm_block_manager *bm = dm_tm_get_bm(c->info->tm);
BUG_ON(c->info->value_type.size != sizeof(value_le));
nr = le32_to_cpu(bn->header.nr_entries);
for (i = 0; i < nr; i++) {
memcpy(&value_le, value_ptr(bn, i), sizeof(value_le));
dm_bm_prefetch(bm, le64_to_cpu(value_le));
}
}
static bool leaf_node(struct dm_btree_cursor *c)
{
struct cursor_node *n = c->nodes + c->depth - 1;
struct btree_node *bn = dm_block_data(n->b);
return le32_to_cpu(bn->header.flags) & LEAF_NODE;
}
static int push_node(struct dm_btree_cursor *c, dm_block_t b)
{
int r;
struct cursor_node *n = c->nodes + c->depth;
if (c->depth >= DM_BTREE_CURSOR_MAX_DEPTH - 1) {
DMERR("couldn't push cursor node, stack depth too high");
return -EINVAL;
}
r = bn_read_lock(c->info, b, &n->b);
if (r)
return r;
n->index = 0;
c->depth++;
if (c->prefetch_leaves || !leaf_node(c))
prefetch_values(c);
return 0;
}
static void pop_node(struct dm_btree_cursor *c)
{
c->depth--;
unlock_block(c->info, c->nodes[c->depth].b);
}
static int inc_or_backtrack(struct dm_btree_cursor *c)
{
struct cursor_node *n;
struct btree_node *bn;
for (;;) {
if (!c->depth)
return -ENODATA;
n = c->nodes + c->depth - 1;
bn = dm_block_data(n->b);
n->index++;
if (n->index < le32_to_cpu(bn->header.nr_entries))
break;
pop_node(c);
}
return 0;
}
static int find_leaf(struct dm_btree_cursor *c)
{
int r = 0;
struct cursor_node *n;
struct btree_node *bn;
__le64 value_le;
for (;;) {
n = c->nodes + c->depth - 1;
bn = dm_block_data(n->b);
if (le32_to_cpu(bn->header.flags) & LEAF_NODE)
break;
memcpy(&value_le, value_ptr(bn, n->index), sizeof(value_le));
r = push_node(c, le64_to_cpu(value_le));
if (r) {
DMERR("push_node failed");
break;
}
}
if (!r && (le32_to_cpu(bn->header.nr_entries) == 0))
return -ENODATA;
return r;
}
int dm_btree_cursor_begin(struct dm_btree_info *info, dm_block_t root,
bool prefetch_leaves, struct dm_btree_cursor *c)
{
int r;
c->info = info;
c->root = root;
c->depth = 0;
c->prefetch_leaves = prefetch_leaves;
r = push_node(c, root);
if (r)
return r;
return find_leaf(c);
}
EXPORT_SYMBOL_GPL(dm_btree_cursor_begin);
void dm_btree_cursor_end(struct dm_btree_cursor *c)
{
while (c->depth)
pop_node(c);
}
EXPORT_SYMBOL_GPL(dm_btree_cursor_end);
int dm_btree_cursor_next(struct dm_btree_cursor *c)
{
int r = inc_or_backtrack(c);
if (!r) {
r = find_leaf(c);
if (r)
DMERR("find_leaf failed");
}
return r;
}
EXPORT_SYMBOL_GPL(dm_btree_cursor_next);
int dm_btree_cursor_skip(struct dm_btree_cursor *c, uint32_t count)
{
int r = 0;
while (count-- && !r)
r = dm_btree_cursor_next(c);
return r;
}
EXPORT_SYMBOL_GPL(dm_btree_cursor_skip);
int dm_btree_cursor_get_value(struct dm_btree_cursor *c, uint64_t *key, void *value_le)
{
if (c->depth) {
struct cursor_node *n = c->nodes + c->depth - 1;
struct btree_node *bn = dm_block_data(n->b);
if (le32_to_cpu(bn->header.flags) & INTERNAL_NODE)
return -EINVAL;
*key = le64_to_cpu(*key_ptr(bn, n->index));
memcpy(value_le, value_ptr(bn, n->index), c->info->value_type.size);
return 0;
} else
return -ENODATA;
}
EXPORT_SYMBOL_GPL(dm_btree_cursor_get_value);
| linux-master | drivers/md/persistent-data/dm-btree.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012 Red Hat, Inc.
*
* This file is released under the GPL.
*/
#include "dm-array.h"
#include "dm-space-map.h"
#include "dm-transaction-manager.h"
#include <linux/export.h>
#include <linux/device-mapper.h>
#define DM_MSG_PREFIX "array"
/*----------------------------------------------------------------*/
/*
* The array is implemented as a fully populated btree, which points to
* blocks that contain the packed values. This is more space efficient
* than just using a btree since we don't store 1 key per value.
*/
struct array_block {
__le32 csum;
__le32 max_entries;
__le32 nr_entries;
__le32 value_size;
__le64 blocknr; /* Block this node is supposed to live in. */
} __packed;
/*----------------------------------------------------------------*/
/*
* Validator methods. As usual we calculate a checksum, and also write the
* block location into the header (paranoia about ssds remapping areas by
* mistake).
*/
#define CSUM_XOR 595846735
static void array_block_prepare_for_write(struct dm_block_validator *v,
struct dm_block *b,
size_t size_of_block)
{
struct array_block *bh_le = dm_block_data(b);
bh_le->blocknr = cpu_to_le64(dm_block_location(b));
bh_le->csum = cpu_to_le32(dm_bm_checksum(&bh_le->max_entries,
size_of_block - sizeof(__le32),
CSUM_XOR));
}
static int array_block_check(struct dm_block_validator *v,
struct dm_block *b,
size_t size_of_block)
{
struct array_block *bh_le = dm_block_data(b);
__le32 csum_disk;
if (dm_block_location(b) != le64_to_cpu(bh_le->blocknr)) {
DMERR_LIMIT("%s failed: blocknr %llu != wanted %llu", __func__,
(unsigned long long) le64_to_cpu(bh_le->blocknr),
(unsigned long long) dm_block_location(b));
return -ENOTBLK;
}
csum_disk = cpu_to_le32(dm_bm_checksum(&bh_le->max_entries,
size_of_block - sizeof(__le32),
CSUM_XOR));
if (csum_disk != bh_le->csum) {
DMERR_LIMIT("%s failed: csum %u != wanted %u", __func__,
(unsigned int) le32_to_cpu(csum_disk),
(unsigned int) le32_to_cpu(bh_le->csum));
return -EILSEQ;
}
return 0;
}
static struct dm_block_validator array_validator = {
.name = "array",
.prepare_for_write = array_block_prepare_for_write,
.check = array_block_check
};
/*----------------------------------------------------------------*/
/*
* Functions for manipulating the array blocks.
*/
/*
* Returns a pointer to a value within an array block.
*
* index - The index into _this_ specific block.
*/
static void *element_at(struct dm_array_info *info, struct array_block *ab,
unsigned int index)
{
unsigned char *entry = (unsigned char *) (ab + 1);
entry += index * info->value_type.size;
return entry;
}
/*
* Utility function that calls one of the value_type methods on every value
* in an array block.
*/
static void on_entries(struct dm_array_info *info, struct array_block *ab,
void (*fn)(void *, const void *, unsigned int))
{
unsigned int nr_entries = le32_to_cpu(ab->nr_entries);
fn(info->value_type.context, element_at(info, ab, 0), nr_entries);
}
/*
* Increment every value in an array block.
*/
static void inc_ablock_entries(struct dm_array_info *info, struct array_block *ab)
{
struct dm_btree_value_type *vt = &info->value_type;
if (vt->inc)
on_entries(info, ab, vt->inc);
}
/*
* Decrement every value in an array block.
*/
static void dec_ablock_entries(struct dm_array_info *info, struct array_block *ab)
{
struct dm_btree_value_type *vt = &info->value_type;
if (vt->dec)
on_entries(info, ab, vt->dec);
}
/*
* Each array block can hold this many values.
*/
static uint32_t calc_max_entries(size_t value_size, size_t size_of_block)
{
return (size_of_block - sizeof(struct array_block)) / value_size;
}
/*
* Allocate a new array block. The caller will need to unlock block.
*/
static int alloc_ablock(struct dm_array_info *info, size_t size_of_block,
uint32_t max_entries,
struct dm_block **block, struct array_block **ab)
{
int r;
r = dm_tm_new_block(info->btree_info.tm, &array_validator, block);
if (r)
return r;
(*ab) = dm_block_data(*block);
(*ab)->max_entries = cpu_to_le32(max_entries);
(*ab)->nr_entries = cpu_to_le32(0);
(*ab)->value_size = cpu_to_le32(info->value_type.size);
return 0;
}
/*
* Pad an array block out with a particular value. Every instance will
* cause an increment of the value_type. new_nr must always be more than
* the current number of entries.
*/
static void fill_ablock(struct dm_array_info *info, struct array_block *ab,
const void *value, unsigned int new_nr)
{
uint32_t nr_entries, delta, i;
struct dm_btree_value_type *vt = &info->value_type;
BUG_ON(new_nr > le32_to_cpu(ab->max_entries));
BUG_ON(new_nr < le32_to_cpu(ab->nr_entries));
nr_entries = le32_to_cpu(ab->nr_entries);
delta = new_nr - nr_entries;
if (vt->inc)
vt->inc(vt->context, value, delta);
for (i = nr_entries; i < new_nr; i++)
memcpy(element_at(info, ab, i), value, vt->size);
ab->nr_entries = cpu_to_le32(new_nr);
}
/*
* Remove some entries from the back of an array block. Every value
* removed will be decremented. new_nr must be <= the current number of
* entries.
*/
static void trim_ablock(struct dm_array_info *info, struct array_block *ab,
unsigned int new_nr)
{
uint32_t nr_entries, delta;
struct dm_btree_value_type *vt = &info->value_type;
BUG_ON(new_nr > le32_to_cpu(ab->max_entries));
BUG_ON(new_nr > le32_to_cpu(ab->nr_entries));
nr_entries = le32_to_cpu(ab->nr_entries);
delta = nr_entries - new_nr;
if (vt->dec)
vt->dec(vt->context, element_at(info, ab, new_nr - 1), delta);
ab->nr_entries = cpu_to_le32(new_nr);
}
/*
* Read locks a block, and coerces it to an array block. The caller must
* unlock 'block' when finished.
*/
static int get_ablock(struct dm_array_info *info, dm_block_t b,
struct dm_block **block, struct array_block **ab)
{
int r;
r = dm_tm_read_lock(info->btree_info.tm, b, &array_validator, block);
if (r)
return r;
*ab = dm_block_data(*block);
return 0;
}
/*
* Unlocks an array block.
*/
static void unlock_ablock(struct dm_array_info *info, struct dm_block *block)
{
dm_tm_unlock(info->btree_info.tm, block);
}
/*----------------------------------------------------------------*/
/*
* Btree manipulation.
*/
/*
* Looks up an array block in the btree, and then read locks it.
*
* index is the index of the index of the array_block, (ie. the array index
* / max_entries).
*/
static int lookup_ablock(struct dm_array_info *info, dm_block_t root,
unsigned int index, struct dm_block **block,
struct array_block **ab)
{
int r;
uint64_t key = index;
__le64 block_le;
r = dm_btree_lookup(&info->btree_info, root, &key, &block_le);
if (r)
return r;
return get_ablock(info, le64_to_cpu(block_le), block, ab);
}
/*
* Insert an array block into the btree. The block is _not_ unlocked.
*/
static int insert_ablock(struct dm_array_info *info, uint64_t index,
struct dm_block *block, dm_block_t *root)
{
__le64 block_le = cpu_to_le64(dm_block_location(block));
__dm_bless_for_disk(block_le);
return dm_btree_insert(&info->btree_info, *root, &index, &block_le, root);
}
/*----------------------------------------------------------------*/
static int __shadow_ablock(struct dm_array_info *info, dm_block_t b,
struct dm_block **block, struct array_block **ab)
{
int inc;
int r = dm_tm_shadow_block(info->btree_info.tm, b,
&array_validator, block, &inc);
if (r)
return r;
*ab = dm_block_data(*block);
if (inc)
inc_ablock_entries(info, *ab);
return 0;
}
/*
* The shadow op will often be a noop. Only insert if it really
* copied data.
*/
static int __reinsert_ablock(struct dm_array_info *info, unsigned int index,
struct dm_block *block, dm_block_t b,
dm_block_t *root)
{
int r = 0;
if (dm_block_location(block) != b) {
/*
* dm_tm_shadow_block will have already decremented the old
* block, but it is still referenced by the btree. We
* increment to stop the insert decrementing it below zero
* when overwriting the old value.
*/
dm_tm_inc(info->btree_info.tm, b);
r = insert_ablock(info, index, block, root);
}
return r;
}
/*
* Looks up an array block in the btree. Then shadows it, and updates the
* btree to point to this new shadow. 'root' is an input/output parameter
* for both the current root block, and the new one.
*/
static int shadow_ablock(struct dm_array_info *info, dm_block_t *root,
unsigned int index, struct dm_block **block,
struct array_block **ab)
{
int r;
uint64_t key = index;
dm_block_t b;
__le64 block_le;
r = dm_btree_lookup(&info->btree_info, *root, &key, &block_le);
if (r)
return r;
b = le64_to_cpu(block_le);
r = __shadow_ablock(info, b, block, ab);
if (r)
return r;
return __reinsert_ablock(info, index, *block, b, root);
}
/*
* Allocate an new array block, and fill it with some values.
*/
static int insert_new_ablock(struct dm_array_info *info, size_t size_of_block,
uint32_t max_entries,
unsigned int block_index, uint32_t nr,
const void *value, dm_block_t *root)
{
int r;
struct dm_block *block;
struct array_block *ab;
r = alloc_ablock(info, size_of_block, max_entries, &block, &ab);
if (r)
return r;
fill_ablock(info, ab, value, nr);
r = insert_ablock(info, block_index, block, root);
unlock_ablock(info, block);
return r;
}
static int insert_full_ablocks(struct dm_array_info *info, size_t size_of_block,
unsigned int begin_block, unsigned int end_block,
unsigned int max_entries, const void *value,
dm_block_t *root)
{
int r = 0;
for (; !r && begin_block != end_block; begin_block++)
r = insert_new_ablock(info, size_of_block, max_entries, begin_block, max_entries, value, root);
return r;
}
/*
* There are a bunch of functions involved with resizing an array. This
* structure holds information that commonly needed by them. Purely here
* to reduce parameter count.
*/
struct resize {
/*
* Describes the array.
*/
struct dm_array_info *info;
/*
* The current root of the array. This gets updated.
*/
dm_block_t root;
/*
* Metadata block size. Used to calculate the nr entries in an
* array block.
*/
size_t size_of_block;
/*
* Maximum nr entries in an array block.
*/
unsigned int max_entries;
/*
* nr of completely full blocks in the array.
*
* 'old' refers to before the resize, 'new' after.
*/
unsigned int old_nr_full_blocks, new_nr_full_blocks;
/*
* Number of entries in the final block. 0 iff only full blocks in
* the array.
*/
unsigned int old_nr_entries_in_last_block, new_nr_entries_in_last_block;
/*
* The default value used when growing the array.
*/
const void *value;
};
/*
* Removes a consecutive set of array blocks from the btree. The values
* in block are decremented as a side effect of the btree remove.
*
* begin_index - the index of the first array block to remove.
* end_index - the one-past-the-end value. ie. this block is not removed.
*/
static int drop_blocks(struct resize *resize, unsigned int begin_index,
unsigned int end_index)
{
int r;
while (begin_index != end_index) {
uint64_t key = begin_index++;
r = dm_btree_remove(&resize->info->btree_info, resize->root,
&key, &resize->root);
if (r)
return r;
}
return 0;
}
/*
* Calculates how many blocks are needed for the array.
*/
static unsigned int total_nr_blocks_needed(unsigned int nr_full_blocks,
unsigned int nr_entries_in_last_block)
{
return nr_full_blocks + (nr_entries_in_last_block ? 1 : 0);
}
/*
* Shrink an array.
*/
static int shrink(struct resize *resize)
{
int r;
unsigned int begin, end;
struct dm_block *block;
struct array_block *ab;
/*
* Lose some blocks from the back?
*/
if (resize->new_nr_full_blocks < resize->old_nr_full_blocks) {
begin = total_nr_blocks_needed(resize->new_nr_full_blocks,
resize->new_nr_entries_in_last_block);
end = total_nr_blocks_needed(resize->old_nr_full_blocks,
resize->old_nr_entries_in_last_block);
r = drop_blocks(resize, begin, end);
if (r)
return r;
}
/*
* Trim the new tail block
*/
if (resize->new_nr_entries_in_last_block) {
r = shadow_ablock(resize->info, &resize->root,
resize->new_nr_full_blocks, &block, &ab);
if (r)
return r;
trim_ablock(resize->info, ab, resize->new_nr_entries_in_last_block);
unlock_ablock(resize->info, block);
}
return 0;
}
/*
* Grow an array.
*/
static int grow_extend_tail_block(struct resize *resize, uint32_t new_nr_entries)
{
int r;
struct dm_block *block;
struct array_block *ab;
r = shadow_ablock(resize->info, &resize->root,
resize->old_nr_full_blocks, &block, &ab);
if (r)
return r;
fill_ablock(resize->info, ab, resize->value, new_nr_entries);
unlock_ablock(resize->info, block);
return r;
}
static int grow_add_tail_block(struct resize *resize)
{
return insert_new_ablock(resize->info, resize->size_of_block,
resize->max_entries,
resize->new_nr_full_blocks,
resize->new_nr_entries_in_last_block,
resize->value, &resize->root);
}
static int grow_needs_more_blocks(struct resize *resize)
{
int r;
unsigned int old_nr_blocks = resize->old_nr_full_blocks;
if (resize->old_nr_entries_in_last_block > 0) {
old_nr_blocks++;
r = grow_extend_tail_block(resize, resize->max_entries);
if (r)
return r;
}
r = insert_full_ablocks(resize->info, resize->size_of_block,
old_nr_blocks,
resize->new_nr_full_blocks,
resize->max_entries, resize->value,
&resize->root);
if (r)
return r;
if (resize->new_nr_entries_in_last_block)
r = grow_add_tail_block(resize);
return r;
}
static int grow(struct resize *resize)
{
if (resize->new_nr_full_blocks > resize->old_nr_full_blocks)
return grow_needs_more_blocks(resize);
else if (resize->old_nr_entries_in_last_block)
return grow_extend_tail_block(resize, resize->new_nr_entries_in_last_block);
else
return grow_add_tail_block(resize);
}
/*----------------------------------------------------------------*/
/*
* These are the value_type functions for the btree elements, which point
* to array blocks.
*/
static void block_inc(void *context, const void *value, unsigned int count)
{
const __le64 *block_le = value;
struct dm_array_info *info = context;
unsigned int i;
for (i = 0; i < count; i++, block_le++)
dm_tm_inc(info->btree_info.tm, le64_to_cpu(*block_le));
}
static void __block_dec(void *context, const void *value)
{
int r;
uint64_t b;
__le64 block_le;
uint32_t ref_count;
struct dm_block *block;
struct array_block *ab;
struct dm_array_info *info = context;
memcpy(&block_le, value, sizeof(block_le));
b = le64_to_cpu(block_le);
r = dm_tm_ref(info->btree_info.tm, b, &ref_count);
if (r) {
DMERR_LIMIT("couldn't get reference count for block %llu",
(unsigned long long) b);
return;
}
if (ref_count == 1) {
/*
* We're about to drop the last reference to this ablock.
* So we need to decrement the ref count of the contents.
*/
r = get_ablock(info, b, &block, &ab);
if (r) {
DMERR_LIMIT("couldn't get array block %llu",
(unsigned long long) b);
return;
}
dec_ablock_entries(info, ab);
unlock_ablock(info, block);
}
dm_tm_dec(info->btree_info.tm, b);
}
static void block_dec(void *context, const void *value, unsigned int count)
{
unsigned int i;
for (i = 0; i < count; i++, value += sizeof(__le64))
__block_dec(context, value);
}
static int block_equal(void *context, const void *value1, const void *value2)
{
return !memcmp(value1, value2, sizeof(__le64));
}
/*----------------------------------------------------------------*/
void dm_array_info_init(struct dm_array_info *info,
struct dm_transaction_manager *tm,
struct dm_btree_value_type *vt)
{
struct dm_btree_value_type *bvt = &info->btree_info.value_type;
memcpy(&info->value_type, vt, sizeof(info->value_type));
info->btree_info.tm = tm;
info->btree_info.levels = 1;
bvt->context = info;
bvt->size = sizeof(__le64);
bvt->inc = block_inc;
bvt->dec = block_dec;
bvt->equal = block_equal;
}
EXPORT_SYMBOL_GPL(dm_array_info_init);
int dm_array_empty(struct dm_array_info *info, dm_block_t *root)
{
return dm_btree_empty(&info->btree_info, root);
}
EXPORT_SYMBOL_GPL(dm_array_empty);
static int array_resize(struct dm_array_info *info, dm_block_t root,
uint32_t old_size, uint32_t new_size,
const void *value, dm_block_t *new_root)
{
int r;
struct resize resize;
if (old_size == new_size) {
*new_root = root;
return 0;
}
resize.info = info;
resize.root = root;
resize.size_of_block = dm_bm_block_size(dm_tm_get_bm(info->btree_info.tm));
resize.max_entries = calc_max_entries(info->value_type.size,
resize.size_of_block);
resize.old_nr_full_blocks = old_size / resize.max_entries;
resize.old_nr_entries_in_last_block = old_size % resize.max_entries;
resize.new_nr_full_blocks = new_size / resize.max_entries;
resize.new_nr_entries_in_last_block = new_size % resize.max_entries;
resize.value = value;
r = ((new_size > old_size) ? grow : shrink)(&resize);
if (r)
return r;
*new_root = resize.root;
return 0;
}
int dm_array_resize(struct dm_array_info *info, dm_block_t root,
uint32_t old_size, uint32_t new_size,
const void *value, dm_block_t *new_root)
__dm_written_to_disk(value)
{
int r = array_resize(info, root, old_size, new_size, value, new_root);
__dm_unbless_for_disk(value);
return r;
}
EXPORT_SYMBOL_GPL(dm_array_resize);
static int populate_ablock_with_values(struct dm_array_info *info, struct array_block *ab,
value_fn fn, void *context,
unsigned int base, unsigned int new_nr)
{
int r;
unsigned int i;
struct dm_btree_value_type *vt = &info->value_type;
BUG_ON(le32_to_cpu(ab->nr_entries));
BUG_ON(new_nr > le32_to_cpu(ab->max_entries));
for (i = 0; i < new_nr; i++) {
r = fn(base + i, element_at(info, ab, i), context);
if (r)
return r;
if (vt->inc)
vt->inc(vt->context, element_at(info, ab, i), 1);
}
ab->nr_entries = cpu_to_le32(new_nr);
return 0;
}
int dm_array_new(struct dm_array_info *info, dm_block_t *root,
uint32_t size, value_fn fn, void *context)
{
int r;
struct dm_block *block;
struct array_block *ab;
unsigned int block_index, end_block, size_of_block, max_entries;
r = dm_array_empty(info, root);
if (r)
return r;
size_of_block = dm_bm_block_size(dm_tm_get_bm(info->btree_info.tm));
max_entries = calc_max_entries(info->value_type.size, size_of_block);
end_block = dm_div_up(size, max_entries);
for (block_index = 0; block_index != end_block; block_index++) {
r = alloc_ablock(info, size_of_block, max_entries, &block, &ab);
if (r)
break;
r = populate_ablock_with_values(info, ab, fn, context,
block_index * max_entries,
min(max_entries, size));
if (r) {
unlock_ablock(info, block);
break;
}
r = insert_ablock(info, block_index, block, root);
unlock_ablock(info, block);
if (r)
break;
size -= max_entries;
}
return r;
}
EXPORT_SYMBOL_GPL(dm_array_new);
int dm_array_del(struct dm_array_info *info, dm_block_t root)
{
return dm_btree_del(&info->btree_info, root);
}
EXPORT_SYMBOL_GPL(dm_array_del);
int dm_array_get_value(struct dm_array_info *info, dm_block_t root,
uint32_t index, void *value_le)
{
int r;
struct dm_block *block;
struct array_block *ab;
size_t size_of_block;
unsigned int entry, max_entries;
size_of_block = dm_bm_block_size(dm_tm_get_bm(info->btree_info.tm));
max_entries = calc_max_entries(info->value_type.size, size_of_block);
r = lookup_ablock(info, root, index / max_entries, &block, &ab);
if (r)
return r;
entry = index % max_entries;
if (entry >= le32_to_cpu(ab->nr_entries))
r = -ENODATA;
else
memcpy(value_le, element_at(info, ab, entry),
info->value_type.size);
unlock_ablock(info, block);
return r;
}
EXPORT_SYMBOL_GPL(dm_array_get_value);
static int array_set_value(struct dm_array_info *info, dm_block_t root,
uint32_t index, const void *value, dm_block_t *new_root)
{
int r;
struct dm_block *block;
struct array_block *ab;
size_t size_of_block;
unsigned int max_entries;
unsigned int entry;
void *old_value;
struct dm_btree_value_type *vt = &info->value_type;
size_of_block = dm_bm_block_size(dm_tm_get_bm(info->btree_info.tm));
max_entries = calc_max_entries(info->value_type.size, size_of_block);
r = shadow_ablock(info, &root, index / max_entries, &block, &ab);
if (r)
return r;
*new_root = root;
entry = index % max_entries;
if (entry >= le32_to_cpu(ab->nr_entries)) {
r = -ENODATA;
goto out;
}
old_value = element_at(info, ab, entry);
if (vt->dec &&
(!vt->equal || !vt->equal(vt->context, old_value, value))) {
vt->dec(vt->context, old_value, 1);
if (vt->inc)
vt->inc(vt->context, value, 1);
}
memcpy(old_value, value, info->value_type.size);
out:
unlock_ablock(info, block);
return r;
}
int dm_array_set_value(struct dm_array_info *info, dm_block_t root,
uint32_t index, const void *value, dm_block_t *new_root)
__dm_written_to_disk(value)
{
int r;
r = array_set_value(info, root, index, value, new_root);
__dm_unbless_for_disk(value);
return r;
}
EXPORT_SYMBOL_GPL(dm_array_set_value);
struct walk_info {
struct dm_array_info *info;
int (*fn)(void *context, uint64_t key, void *leaf);
void *context;
};
static int walk_ablock(void *context, uint64_t *keys, void *leaf)
{
struct walk_info *wi = context;
int r;
unsigned int i;
__le64 block_le;
unsigned int nr_entries, max_entries;
struct dm_block *block;
struct array_block *ab;
memcpy(&block_le, leaf, sizeof(block_le));
r = get_ablock(wi->info, le64_to_cpu(block_le), &block, &ab);
if (r)
return r;
max_entries = le32_to_cpu(ab->max_entries);
nr_entries = le32_to_cpu(ab->nr_entries);
for (i = 0; i < nr_entries; i++) {
r = wi->fn(wi->context, keys[0] * max_entries + i,
element_at(wi->info, ab, i));
if (r)
break;
}
unlock_ablock(wi->info, block);
return r;
}
int dm_array_walk(struct dm_array_info *info, dm_block_t root,
int (*fn)(void *, uint64_t key, void *leaf),
void *context)
{
struct walk_info wi;
wi.info = info;
wi.fn = fn;
wi.context = context;
return dm_btree_walk(&info->btree_info, root, walk_ablock, &wi);
}
EXPORT_SYMBOL_GPL(dm_array_walk);
/*----------------------------------------------------------------*/
static int load_ablock(struct dm_array_cursor *c)
{
int r;
__le64 value_le;
uint64_t key;
if (c->block)
unlock_ablock(c->info, c->block);
c->block = NULL;
c->ab = NULL;
c->index = 0;
r = dm_btree_cursor_get_value(&c->cursor, &key, &value_le);
if (r) {
DMERR("dm_btree_cursor_get_value failed");
dm_btree_cursor_end(&c->cursor);
} else {
r = get_ablock(c->info, le64_to_cpu(value_le), &c->block, &c->ab);
if (r) {
DMERR("get_ablock failed");
dm_btree_cursor_end(&c->cursor);
}
}
return r;
}
int dm_array_cursor_begin(struct dm_array_info *info, dm_block_t root,
struct dm_array_cursor *c)
{
int r;
memset(c, 0, sizeof(*c));
c->info = info;
r = dm_btree_cursor_begin(&info->btree_info, root, true, &c->cursor);
if (r) {
DMERR("couldn't create btree cursor");
return r;
}
return load_ablock(c);
}
EXPORT_SYMBOL_GPL(dm_array_cursor_begin);
void dm_array_cursor_end(struct dm_array_cursor *c)
{
if (c->block) {
unlock_ablock(c->info, c->block);
dm_btree_cursor_end(&c->cursor);
}
}
EXPORT_SYMBOL_GPL(dm_array_cursor_end);
int dm_array_cursor_next(struct dm_array_cursor *c)
{
int r;
if (!c->block)
return -ENODATA;
c->index++;
if (c->index >= le32_to_cpu(c->ab->nr_entries)) {
r = dm_btree_cursor_next(&c->cursor);
if (r)
return r;
r = load_ablock(c);
if (r)
return r;
}
return 0;
}
EXPORT_SYMBOL_GPL(dm_array_cursor_next);
int dm_array_cursor_skip(struct dm_array_cursor *c, uint32_t count)
{
int r;
do {
uint32_t remaining = le32_to_cpu(c->ab->nr_entries) - c->index;
if (count < remaining) {
c->index += count;
return 0;
}
count -= remaining;
r = dm_array_cursor_next(c);
} while (!r);
return r;
}
EXPORT_SYMBOL_GPL(dm_array_cursor_skip);
void dm_array_cursor_get_value(struct dm_array_cursor *c, void **value_le)
{
*value_le = element_at(c->info, c->ab, c->index);
}
EXPORT_SYMBOL_GPL(dm_array_cursor_get_value);
/*----------------------------------------------------------------*/
| linux-master | drivers/md/persistent-data/dm-array.c |
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2011 Red Hat, Inc.
*
* This file is released under the GPL.
*/
#include "dm-btree-internal.h"
#include "dm-transaction-manager.h"
#include <linux/device-mapper.h>
#define DM_MSG_PREFIX "btree spine"
/*----------------------------------------------------------------*/
#define BTREE_CSUM_XOR 121107
static void node_prepare_for_write(struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
struct btree_node *n = dm_block_data(b);
struct node_header *h = &n->header;
h->blocknr = cpu_to_le64(dm_block_location(b));
h->csum = cpu_to_le32(dm_bm_checksum(&h->flags,
block_size - sizeof(__le32),
BTREE_CSUM_XOR));
}
static int node_check(struct dm_block_validator *v,
struct dm_block *b,
size_t block_size)
{
struct btree_node *n = dm_block_data(b);
struct node_header *h = &n->header;
size_t value_size;
__le32 csum_disk;
uint32_t flags, nr_entries, max_entries;
if (dm_block_location(b) != le64_to_cpu(h->blocknr)) {
DMERR_LIMIT("%s failed: blocknr %llu != wanted %llu", __func__,
le64_to_cpu(h->blocknr), dm_block_location(b));
return -ENOTBLK;
}
csum_disk = cpu_to_le32(dm_bm_checksum(&h->flags,
block_size - sizeof(__le32),
BTREE_CSUM_XOR));
if (csum_disk != h->csum) {
DMERR_LIMIT("%s failed: csum %u != wanted %u", __func__,
le32_to_cpu(csum_disk), le32_to_cpu(h->csum));
return -EILSEQ;
}
nr_entries = le32_to_cpu(h->nr_entries);
max_entries = le32_to_cpu(h->max_entries);
value_size = le32_to_cpu(h->value_size);
if (sizeof(struct node_header) +
(sizeof(__le64) + value_size) * max_entries > block_size) {
DMERR_LIMIT("%s failed: max_entries too large", __func__);
return -EILSEQ;
}
if (nr_entries > max_entries) {
DMERR_LIMIT("%s failed: too many entries", __func__);
return -EILSEQ;
}
/*
* The node must be either INTERNAL or LEAF.
*/
flags = le32_to_cpu(h->flags);
if (!(flags & INTERNAL_NODE) && !(flags & LEAF_NODE)) {
DMERR_LIMIT("%s failed: node is neither INTERNAL or LEAF", __func__);
return -EILSEQ;
}
return 0;
}
struct dm_block_validator btree_node_validator = {
.name = "btree_node",
.prepare_for_write = node_prepare_for_write,
.check = node_check
};
/*----------------------------------------------------------------*/
int bn_read_lock(struct dm_btree_info *info, dm_block_t b,
struct dm_block **result)
{
return dm_tm_read_lock(info->tm, b, &btree_node_validator, result);
}
static int bn_shadow(struct dm_btree_info *info, dm_block_t orig,
struct dm_btree_value_type *vt,
struct dm_block **result)
{
int r, inc;
r = dm_tm_shadow_block(info->tm, orig, &btree_node_validator,
result, &inc);
if (!r && inc)
inc_children(info->tm, dm_block_data(*result), vt);
return r;
}
int new_block(struct dm_btree_info *info, struct dm_block **result)
{
return dm_tm_new_block(info->tm, &btree_node_validator, result);
}
void unlock_block(struct dm_btree_info *info, struct dm_block *b)
{
dm_tm_unlock(info->tm, b);
}
/*----------------------------------------------------------------*/
void init_ro_spine(struct ro_spine *s, struct dm_btree_info *info)
{
s->info = info;
s->count = 0;
s->nodes[0] = NULL;
s->nodes[1] = NULL;
}
void exit_ro_spine(struct ro_spine *s)
{
int i;
for (i = 0; i < s->count; i++)
unlock_block(s->info, s->nodes[i]);
}
int ro_step(struct ro_spine *s, dm_block_t new_child)
{
int r;
if (s->count == 2) {
unlock_block(s->info, s->nodes[0]);
s->nodes[0] = s->nodes[1];
s->count--;
}
r = bn_read_lock(s->info, new_child, s->nodes + s->count);
if (!r)
s->count++;
return r;
}
void ro_pop(struct ro_spine *s)
{
BUG_ON(!s->count);
--s->count;
unlock_block(s->info, s->nodes[s->count]);
}
struct btree_node *ro_node(struct ro_spine *s)
{
struct dm_block *block;
BUG_ON(!s->count);
block = s->nodes[s->count - 1];
return dm_block_data(block);
}
/*----------------------------------------------------------------*/
void init_shadow_spine(struct shadow_spine *s, struct dm_btree_info *info)
{
s->info = info;
s->count = 0;
}
void exit_shadow_spine(struct shadow_spine *s)
{
int i;
for (i = 0; i < s->count; i++)
unlock_block(s->info, s->nodes[i]);
}
int shadow_step(struct shadow_spine *s, dm_block_t b,
struct dm_btree_value_type *vt)
{
int r;
if (s->count == 2) {
unlock_block(s->info, s->nodes[0]);
s->nodes[0] = s->nodes[1];
s->count--;
}
r = bn_shadow(s->info, b, vt, s->nodes + s->count);
if (!r) {
if (!s->count)
s->root = dm_block_location(s->nodes[0]);
s->count++;
}
return r;
}
struct dm_block *shadow_current(struct shadow_spine *s)
{
BUG_ON(!s->count);
return s->nodes[s->count - 1];
}
struct dm_block *shadow_parent(struct shadow_spine *s)
{
BUG_ON(s->count != 2);
return s->count == 2 ? s->nodes[0] : NULL;
}
int shadow_has_parent(struct shadow_spine *s)
{
return s->count >= 2;
}
dm_block_t shadow_root(struct shadow_spine *s)
{
return s->root;
}
static void le64_inc(void *context, const void *value_le, unsigned int count)
{
dm_tm_with_runs(context, value_le, count, dm_tm_inc_range);
}
static void le64_dec(void *context, const void *value_le, unsigned int count)
{
dm_tm_with_runs(context, value_le, count, dm_tm_dec_range);
}
static int le64_equal(void *context, const void *value1_le, const void *value2_le)
{
__le64 v1_le, v2_le;
memcpy(&v1_le, value1_le, sizeof(v1_le));
memcpy(&v2_le, value2_le, sizeof(v2_le));
return v1_le == v2_le;
}
void init_le64_type(struct dm_transaction_manager *tm,
struct dm_btree_value_type *vt)
{
vt->context = tm;
vt->size = sizeof(__le64);
vt->inc = le64_inc;
vt->dec = le64_dec;
vt->equal = le64_equal;
}
| linux-master | drivers/md/persistent-data/dm-btree-spine.c |
// SPDX-License-Identifier: GPL-2.0
/*
* bcache setup/teardown code, and some metadata io - read a superblock and
* figure out what to do with it.
*
* Copyright 2010, 2011 Kent Overstreet <[email protected]>
* Copyright 2012 Google, Inc.
*/
#include "bcache.h"
#include "btree.h"
#include "debug.h"
#include "extents.h"
#include "request.h"
#include "writeback.h"
#include "features.h"
#include <linux/blkdev.h>
#include <linux/pagemap.h>
#include <linux/debugfs.h>
#include <linux/idr.h>
#include <linux/kthread.h>
#include <linux/workqueue.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/reboot.h>
#include <linux/sysfs.h>
unsigned int bch_cutoff_writeback;
unsigned int bch_cutoff_writeback_sync;
static const char bcache_magic[] = {
0xc6, 0x85, 0x73, 0xf6, 0x4e, 0x1a, 0x45, 0xca,
0x82, 0x65, 0xf5, 0x7f, 0x48, 0xba, 0x6d, 0x81
};
static const char invalid_uuid[] = {
0xa0, 0x3e, 0xf8, 0xed, 0x3e, 0xe1, 0xb8, 0x78,
0xc8, 0x50, 0xfc, 0x5e, 0xcb, 0x16, 0xcd, 0x99
};
static struct kobject *bcache_kobj;
struct mutex bch_register_lock;
bool bcache_is_reboot;
LIST_HEAD(bch_cache_sets);
static LIST_HEAD(uncached_devices);
static int bcache_major;
static DEFINE_IDA(bcache_device_idx);
static wait_queue_head_t unregister_wait;
struct workqueue_struct *bcache_wq;
struct workqueue_struct *bch_flush_wq;
struct workqueue_struct *bch_journal_wq;
#define BTREE_MAX_PAGES (256 * 1024 / PAGE_SIZE)
/* limitation of partitions number on single bcache device */
#define BCACHE_MINORS 128
/* limitation of bcache devices number on single system */
#define BCACHE_DEVICE_IDX_MAX ((1U << MINORBITS)/BCACHE_MINORS)
/* Superblock */
static unsigned int get_bucket_size(struct cache_sb *sb, struct cache_sb_disk *s)
{
unsigned int bucket_size = le16_to_cpu(s->bucket_size);
if (sb->version >= BCACHE_SB_VERSION_CDEV_WITH_FEATURES) {
if (bch_has_feature_large_bucket(sb)) {
unsigned int max, order;
max = sizeof(unsigned int) * BITS_PER_BYTE - 1;
order = le16_to_cpu(s->bucket_size);
/*
* bcache tool will make sure the overflow won't
* happen, an error message here is enough.
*/
if (order > max)
pr_err("Bucket size (1 << %u) overflows\n",
order);
bucket_size = 1 << order;
} else if (bch_has_feature_obso_large_bucket(sb)) {
bucket_size +=
le16_to_cpu(s->obso_bucket_size_hi) << 16;
}
}
return bucket_size;
}
static const char *read_super_common(struct cache_sb *sb, struct block_device *bdev,
struct cache_sb_disk *s)
{
const char *err;
unsigned int i;
sb->first_bucket= le16_to_cpu(s->first_bucket);
sb->nbuckets = le64_to_cpu(s->nbuckets);
sb->bucket_size = get_bucket_size(sb, s);
sb->nr_in_set = le16_to_cpu(s->nr_in_set);
sb->nr_this_dev = le16_to_cpu(s->nr_this_dev);
err = "Too many journal buckets";
if (sb->keys > SB_JOURNAL_BUCKETS)
goto err;
err = "Too many buckets";
if (sb->nbuckets > LONG_MAX)
goto err;
err = "Not enough buckets";
if (sb->nbuckets < 1 << 7)
goto err;
err = "Bad block size (not power of 2)";
if (!is_power_of_2(sb->block_size))
goto err;
err = "Bad block size (larger than page size)";
if (sb->block_size > PAGE_SECTORS)
goto err;
err = "Bad bucket size (not power of 2)";
if (!is_power_of_2(sb->bucket_size))
goto err;
err = "Bad bucket size (smaller than page size)";
if (sb->bucket_size < PAGE_SECTORS)
goto err;
err = "Invalid superblock: device too small";
if (get_capacity(bdev->bd_disk) <
sb->bucket_size * sb->nbuckets)
goto err;
err = "Bad UUID";
if (bch_is_zero(sb->set_uuid, 16))
goto err;
err = "Bad cache device number in set";
if (!sb->nr_in_set ||
sb->nr_in_set <= sb->nr_this_dev ||
sb->nr_in_set > MAX_CACHES_PER_SET)
goto err;
err = "Journal buckets not sequential";
for (i = 0; i < sb->keys; i++)
if (sb->d[i] != sb->first_bucket + i)
goto err;
err = "Too many journal buckets";
if (sb->first_bucket + sb->keys > sb->nbuckets)
goto err;
err = "Invalid superblock: first bucket comes before end of super";
if (sb->first_bucket * sb->bucket_size < 16)
goto err;
err = NULL;
err:
return err;
}
static const char *read_super(struct cache_sb *sb, struct block_device *bdev,
struct cache_sb_disk **res)
{
const char *err;
struct cache_sb_disk *s;
struct page *page;
unsigned int i;
page = read_cache_page_gfp(bdev->bd_inode->i_mapping,
SB_OFFSET >> PAGE_SHIFT, GFP_KERNEL);
if (IS_ERR(page))
return "IO error";
s = page_address(page) + offset_in_page(SB_OFFSET);
sb->offset = le64_to_cpu(s->offset);
sb->version = le64_to_cpu(s->version);
memcpy(sb->magic, s->magic, 16);
memcpy(sb->uuid, s->uuid, 16);
memcpy(sb->set_uuid, s->set_uuid, 16);
memcpy(sb->label, s->label, SB_LABEL_SIZE);
sb->flags = le64_to_cpu(s->flags);
sb->seq = le64_to_cpu(s->seq);
sb->last_mount = le32_to_cpu(s->last_mount);
sb->keys = le16_to_cpu(s->keys);
for (i = 0; i < SB_JOURNAL_BUCKETS; i++)
sb->d[i] = le64_to_cpu(s->d[i]);
pr_debug("read sb version %llu, flags %llu, seq %llu, journal size %u\n",
sb->version, sb->flags, sb->seq, sb->keys);
err = "Not a bcache superblock (bad offset)";
if (sb->offset != SB_SECTOR)
goto err;
err = "Not a bcache superblock (bad magic)";
if (memcmp(sb->magic, bcache_magic, 16))
goto err;
err = "Bad checksum";
if (s->csum != csum_set(s))
goto err;
err = "Bad UUID";
if (bch_is_zero(sb->uuid, 16))
goto err;
sb->block_size = le16_to_cpu(s->block_size);
err = "Superblock block size smaller than device block size";
if (sb->block_size << 9 < bdev_logical_block_size(bdev))
goto err;
switch (sb->version) {
case BCACHE_SB_VERSION_BDEV:
sb->data_offset = BDEV_DATA_START_DEFAULT;
break;
case BCACHE_SB_VERSION_BDEV_WITH_OFFSET:
case BCACHE_SB_VERSION_BDEV_WITH_FEATURES:
sb->data_offset = le64_to_cpu(s->data_offset);
err = "Bad data offset";
if (sb->data_offset < BDEV_DATA_START_DEFAULT)
goto err;
break;
case BCACHE_SB_VERSION_CDEV:
case BCACHE_SB_VERSION_CDEV_WITH_UUID:
err = read_super_common(sb, bdev, s);
if (err)
goto err;
break;
case BCACHE_SB_VERSION_CDEV_WITH_FEATURES:
/*
* Feature bits are needed in read_super_common(),
* convert them firstly.
*/
sb->feature_compat = le64_to_cpu(s->feature_compat);
sb->feature_incompat = le64_to_cpu(s->feature_incompat);
sb->feature_ro_compat = le64_to_cpu(s->feature_ro_compat);
/* Check incompatible features */
err = "Unsupported compatible feature found";
if (bch_has_unknown_compat_features(sb))
goto err;
err = "Unsupported read-only compatible feature found";
if (bch_has_unknown_ro_compat_features(sb))
goto err;
err = "Unsupported incompatible feature found";
if (bch_has_unknown_incompat_features(sb))
goto err;
err = read_super_common(sb, bdev, s);
if (err)
goto err;
break;
default:
err = "Unsupported superblock version";
goto err;
}
sb->last_mount = (u32)ktime_get_real_seconds();
*res = s;
return NULL;
err:
put_page(page);
return err;
}
static void write_bdev_super_endio(struct bio *bio)
{
struct cached_dev *dc = bio->bi_private;
if (bio->bi_status)
bch_count_backing_io_errors(dc, bio);
closure_put(&dc->sb_write);
}
static void __write_super(struct cache_sb *sb, struct cache_sb_disk *out,
struct bio *bio)
{
unsigned int i;
bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_META;
bio->bi_iter.bi_sector = SB_SECTOR;
__bio_add_page(bio, virt_to_page(out), SB_SIZE,
offset_in_page(out));
out->offset = cpu_to_le64(sb->offset);
memcpy(out->uuid, sb->uuid, 16);
memcpy(out->set_uuid, sb->set_uuid, 16);
memcpy(out->label, sb->label, SB_LABEL_SIZE);
out->flags = cpu_to_le64(sb->flags);
out->seq = cpu_to_le64(sb->seq);
out->last_mount = cpu_to_le32(sb->last_mount);
out->first_bucket = cpu_to_le16(sb->first_bucket);
out->keys = cpu_to_le16(sb->keys);
for (i = 0; i < sb->keys; i++)
out->d[i] = cpu_to_le64(sb->d[i]);
if (sb->version >= BCACHE_SB_VERSION_CDEV_WITH_FEATURES) {
out->feature_compat = cpu_to_le64(sb->feature_compat);
out->feature_incompat = cpu_to_le64(sb->feature_incompat);
out->feature_ro_compat = cpu_to_le64(sb->feature_ro_compat);
}
out->version = cpu_to_le64(sb->version);
out->csum = csum_set(out);
pr_debug("ver %llu, flags %llu, seq %llu\n",
sb->version, sb->flags, sb->seq);
submit_bio(bio);
}
static void bch_write_bdev_super_unlock(struct closure *cl)
{
struct cached_dev *dc = container_of(cl, struct cached_dev, sb_write);
up(&dc->sb_write_mutex);
}
void bch_write_bdev_super(struct cached_dev *dc, struct closure *parent)
{
struct closure *cl = &dc->sb_write;
struct bio *bio = &dc->sb_bio;
down(&dc->sb_write_mutex);
closure_init(cl, parent);
bio_init(bio, dc->bdev, dc->sb_bv, 1, 0);
bio->bi_end_io = write_bdev_super_endio;
bio->bi_private = dc;
closure_get(cl);
/* I/O request sent to backing device */
__write_super(&dc->sb, dc->sb_disk, bio);
closure_return_with_destructor(cl, bch_write_bdev_super_unlock);
}
static void write_super_endio(struct bio *bio)
{
struct cache *ca = bio->bi_private;
/* is_read = 0 */
bch_count_io_errors(ca, bio->bi_status, 0,
"writing superblock");
closure_put(&ca->set->sb_write);
}
static void bcache_write_super_unlock(struct closure *cl)
{
struct cache_set *c = container_of(cl, struct cache_set, sb_write);
up(&c->sb_write_mutex);
}
void bcache_write_super(struct cache_set *c)
{
struct closure *cl = &c->sb_write;
struct cache *ca = c->cache;
struct bio *bio = &ca->sb_bio;
unsigned int version = BCACHE_SB_VERSION_CDEV_WITH_UUID;
down(&c->sb_write_mutex);
closure_init(cl, &c->cl);
ca->sb.seq++;
if (ca->sb.version < version)
ca->sb.version = version;
bio_init(bio, ca->bdev, ca->sb_bv, 1, 0);
bio->bi_end_io = write_super_endio;
bio->bi_private = ca;
closure_get(cl);
__write_super(&ca->sb, ca->sb_disk, bio);
closure_return_with_destructor(cl, bcache_write_super_unlock);
}
/* UUID io */
static void uuid_endio(struct bio *bio)
{
struct closure *cl = bio->bi_private;
struct cache_set *c = container_of(cl, struct cache_set, uuid_write);
cache_set_err_on(bio->bi_status, c, "accessing uuids");
bch_bbio_free(bio, c);
closure_put(cl);
}
static void uuid_io_unlock(struct closure *cl)
{
struct cache_set *c = container_of(cl, struct cache_set, uuid_write);
up(&c->uuid_write_mutex);
}
static void uuid_io(struct cache_set *c, blk_opf_t opf, struct bkey *k,
struct closure *parent)
{
struct closure *cl = &c->uuid_write;
struct uuid_entry *u;
unsigned int i;
char buf[80];
BUG_ON(!parent);
down(&c->uuid_write_mutex);
closure_init(cl, parent);
for (i = 0; i < KEY_PTRS(k); i++) {
struct bio *bio = bch_bbio_alloc(c);
bio->bi_opf = opf | REQ_SYNC | REQ_META;
bio->bi_iter.bi_size = KEY_SIZE(k) << 9;
bio->bi_end_io = uuid_endio;
bio->bi_private = cl;
bch_bio_map(bio, c->uuids);
bch_submit_bbio(bio, c, k, i);
if ((opf & REQ_OP_MASK) != REQ_OP_WRITE)
break;
}
bch_extent_to_text(buf, sizeof(buf), k);
pr_debug("%s UUIDs at %s\n", (opf & REQ_OP_MASK) == REQ_OP_WRITE ?
"wrote" : "read", buf);
for (u = c->uuids; u < c->uuids + c->nr_uuids; u++)
if (!bch_is_zero(u->uuid, 16))
pr_debug("Slot %zi: %pU: %s: 1st: %u last: %u inv: %u\n",
u - c->uuids, u->uuid, u->label,
u->first_reg, u->last_reg, u->invalidated);
closure_return_with_destructor(cl, uuid_io_unlock);
}
static char *uuid_read(struct cache_set *c, struct jset *j, struct closure *cl)
{
struct bkey *k = &j->uuid_bucket;
if (__bch_btree_ptr_invalid(c, k))
return "bad uuid pointer";
bkey_copy(&c->uuid_bucket, k);
uuid_io(c, REQ_OP_READ, k, cl);
if (j->version < BCACHE_JSET_VERSION_UUIDv1) {
struct uuid_entry_v0 *u0 = (void *) c->uuids;
struct uuid_entry *u1 = (void *) c->uuids;
int i;
closure_sync(cl);
/*
* Since the new uuid entry is bigger than the old, we have to
* convert starting at the highest memory address and work down
* in order to do it in place
*/
for (i = c->nr_uuids - 1;
i >= 0;
--i) {
memcpy(u1[i].uuid, u0[i].uuid, 16);
memcpy(u1[i].label, u0[i].label, 32);
u1[i].first_reg = u0[i].first_reg;
u1[i].last_reg = u0[i].last_reg;
u1[i].invalidated = u0[i].invalidated;
u1[i].flags = 0;
u1[i].sectors = 0;
}
}
return NULL;
}
static int __uuid_write(struct cache_set *c)
{
BKEY_PADDED(key) k;
struct closure cl;
struct cache *ca = c->cache;
unsigned int size;
closure_init_stack(&cl);
lockdep_assert_held(&bch_register_lock);
if (bch_bucket_alloc_set(c, RESERVE_BTREE, &k.key, true))
return 1;
size = meta_bucket_pages(&ca->sb) * PAGE_SECTORS;
SET_KEY_SIZE(&k.key, size);
uuid_io(c, REQ_OP_WRITE, &k.key, &cl);
closure_sync(&cl);
/* Only one bucket used for uuid write */
atomic_long_add(ca->sb.bucket_size, &ca->meta_sectors_written);
bkey_copy(&c->uuid_bucket, &k.key);
bkey_put(c, &k.key);
return 0;
}
int bch_uuid_write(struct cache_set *c)
{
int ret = __uuid_write(c);
if (!ret)
bch_journal_meta(c, NULL);
return ret;
}
static struct uuid_entry *uuid_find(struct cache_set *c, const char *uuid)
{
struct uuid_entry *u;
for (u = c->uuids;
u < c->uuids + c->nr_uuids; u++)
if (!memcmp(u->uuid, uuid, 16))
return u;
return NULL;
}
static struct uuid_entry *uuid_find_empty(struct cache_set *c)
{
static const char zero_uuid[16] = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
return uuid_find(c, zero_uuid);
}
/*
* Bucket priorities/gens:
*
* For each bucket, we store on disk its
* 8 bit gen
* 16 bit priority
*
* See alloc.c for an explanation of the gen. The priority is used to implement
* lru (and in the future other) cache replacement policies; for most purposes
* it's just an opaque integer.
*
* The gens and the priorities don't have a whole lot to do with each other, and
* it's actually the gens that must be written out at specific times - it's no
* big deal if the priorities don't get written, if we lose them we just reuse
* buckets in suboptimal order.
*
* On disk they're stored in a packed array, and in as many buckets are required
* to fit them all. The buckets we use to store them form a list; the journal
* header points to the first bucket, the first bucket points to the second
* bucket, et cetera.
*
* This code is used by the allocation code; periodically (whenever it runs out
* of buckets to allocate from) the allocation code will invalidate some
* buckets, but it can't use those buckets until their new gens are safely on
* disk.
*/
static void prio_endio(struct bio *bio)
{
struct cache *ca = bio->bi_private;
cache_set_err_on(bio->bi_status, ca->set, "accessing priorities");
bch_bbio_free(bio, ca->set);
closure_put(&ca->prio);
}
static void prio_io(struct cache *ca, uint64_t bucket, blk_opf_t opf)
{
struct closure *cl = &ca->prio;
struct bio *bio = bch_bbio_alloc(ca->set);
closure_init_stack(cl);
bio->bi_iter.bi_sector = bucket * ca->sb.bucket_size;
bio_set_dev(bio, ca->bdev);
bio->bi_iter.bi_size = meta_bucket_bytes(&ca->sb);
bio->bi_end_io = prio_endio;
bio->bi_private = ca;
bio->bi_opf = opf | REQ_SYNC | REQ_META;
bch_bio_map(bio, ca->disk_buckets);
closure_bio_submit(ca->set, bio, &ca->prio);
closure_sync(cl);
}
int bch_prio_write(struct cache *ca, bool wait)
{
int i;
struct bucket *b;
struct closure cl;
pr_debug("free_prio=%zu, free_none=%zu, free_inc=%zu\n",
fifo_used(&ca->free[RESERVE_PRIO]),
fifo_used(&ca->free[RESERVE_NONE]),
fifo_used(&ca->free_inc));
/*
* Pre-check if there are enough free buckets. In the non-blocking
* scenario it's better to fail early rather than starting to allocate
* buckets and do a cleanup later in case of failure.
*/
if (!wait) {
size_t avail = fifo_used(&ca->free[RESERVE_PRIO]) +
fifo_used(&ca->free[RESERVE_NONE]);
if (prio_buckets(ca) > avail)
return -ENOMEM;
}
closure_init_stack(&cl);
lockdep_assert_held(&ca->set->bucket_lock);
ca->disk_buckets->seq++;
atomic_long_add(ca->sb.bucket_size * prio_buckets(ca),
&ca->meta_sectors_written);
for (i = prio_buckets(ca) - 1; i >= 0; --i) {
long bucket;
struct prio_set *p = ca->disk_buckets;
struct bucket_disk *d = p->data;
struct bucket_disk *end = d + prios_per_bucket(ca);
for (b = ca->buckets + i * prios_per_bucket(ca);
b < ca->buckets + ca->sb.nbuckets && d < end;
b++, d++) {
d->prio = cpu_to_le16(b->prio);
d->gen = b->gen;
}
p->next_bucket = ca->prio_buckets[i + 1];
p->magic = pset_magic(&ca->sb);
p->csum = bch_crc64(&p->magic, meta_bucket_bytes(&ca->sb) - 8);
bucket = bch_bucket_alloc(ca, RESERVE_PRIO, wait);
BUG_ON(bucket == -1);
mutex_unlock(&ca->set->bucket_lock);
prio_io(ca, bucket, REQ_OP_WRITE);
mutex_lock(&ca->set->bucket_lock);
ca->prio_buckets[i] = bucket;
atomic_dec_bug(&ca->buckets[bucket].pin);
}
mutex_unlock(&ca->set->bucket_lock);
bch_journal_meta(ca->set, &cl);
closure_sync(&cl);
mutex_lock(&ca->set->bucket_lock);
/*
* Don't want the old priorities to get garbage collected until after we
* finish writing the new ones, and they're journalled
*/
for (i = 0; i < prio_buckets(ca); i++) {
if (ca->prio_last_buckets[i])
__bch_bucket_free(ca,
&ca->buckets[ca->prio_last_buckets[i]]);
ca->prio_last_buckets[i] = ca->prio_buckets[i];
}
return 0;
}
static int prio_read(struct cache *ca, uint64_t bucket)
{
struct prio_set *p = ca->disk_buckets;
struct bucket_disk *d = p->data + prios_per_bucket(ca), *end = d;
struct bucket *b;
unsigned int bucket_nr = 0;
int ret = -EIO;
for (b = ca->buckets;
b < ca->buckets + ca->sb.nbuckets;
b++, d++) {
if (d == end) {
ca->prio_buckets[bucket_nr] = bucket;
ca->prio_last_buckets[bucket_nr] = bucket;
bucket_nr++;
prio_io(ca, bucket, REQ_OP_READ);
if (p->csum !=
bch_crc64(&p->magic, meta_bucket_bytes(&ca->sb) - 8)) {
pr_warn("bad csum reading priorities\n");
goto out;
}
if (p->magic != pset_magic(&ca->sb)) {
pr_warn("bad magic reading priorities\n");
goto out;
}
bucket = p->next_bucket;
d = p->data;
}
b->prio = le16_to_cpu(d->prio);
b->gen = b->last_gc = d->gen;
}
ret = 0;
out:
return ret;
}
/* Bcache device */
static int open_dev(struct gendisk *disk, blk_mode_t mode)
{
struct bcache_device *d = disk->private_data;
if (test_bit(BCACHE_DEV_CLOSING, &d->flags))
return -ENXIO;
closure_get(&d->cl);
return 0;
}
static void release_dev(struct gendisk *b)
{
struct bcache_device *d = b->private_data;
closure_put(&d->cl);
}
static int ioctl_dev(struct block_device *b, blk_mode_t mode,
unsigned int cmd, unsigned long arg)
{
struct bcache_device *d = b->bd_disk->private_data;
return d->ioctl(d, mode, cmd, arg);
}
static const struct block_device_operations bcache_cached_ops = {
.submit_bio = cached_dev_submit_bio,
.open = open_dev,
.release = release_dev,
.ioctl = ioctl_dev,
.owner = THIS_MODULE,
};
static const struct block_device_operations bcache_flash_ops = {
.submit_bio = flash_dev_submit_bio,
.open = open_dev,
.release = release_dev,
.ioctl = ioctl_dev,
.owner = THIS_MODULE,
};
void bcache_device_stop(struct bcache_device *d)
{
if (!test_and_set_bit(BCACHE_DEV_CLOSING, &d->flags))
/*
* closure_fn set to
* - cached device: cached_dev_flush()
* - flash dev: flash_dev_flush()
*/
closure_queue(&d->cl);
}
static void bcache_device_unlink(struct bcache_device *d)
{
lockdep_assert_held(&bch_register_lock);
if (d->c && !test_and_set_bit(BCACHE_DEV_UNLINK_DONE, &d->flags)) {
struct cache *ca = d->c->cache;
sysfs_remove_link(&d->c->kobj, d->name);
sysfs_remove_link(&d->kobj, "cache");
bd_unlink_disk_holder(ca->bdev, d->disk);
}
}
static void bcache_device_link(struct bcache_device *d, struct cache_set *c,
const char *name)
{
struct cache *ca = c->cache;
int ret;
bd_link_disk_holder(ca->bdev, d->disk);
snprintf(d->name, BCACHEDEVNAME_SIZE,
"%s%u", name, d->id);
ret = sysfs_create_link(&d->kobj, &c->kobj, "cache");
if (ret < 0)
pr_err("Couldn't create device -> cache set symlink\n");
ret = sysfs_create_link(&c->kobj, &d->kobj, d->name);
if (ret < 0)
pr_err("Couldn't create cache set -> device symlink\n");
clear_bit(BCACHE_DEV_UNLINK_DONE, &d->flags);
}
static void bcache_device_detach(struct bcache_device *d)
{
lockdep_assert_held(&bch_register_lock);
atomic_dec(&d->c->attached_dev_nr);
if (test_bit(BCACHE_DEV_DETACHING, &d->flags)) {
struct uuid_entry *u = d->c->uuids + d->id;
SET_UUID_FLASH_ONLY(u, 0);
memcpy(u->uuid, invalid_uuid, 16);
u->invalidated = cpu_to_le32((u32)ktime_get_real_seconds());
bch_uuid_write(d->c);
}
bcache_device_unlink(d);
d->c->devices[d->id] = NULL;
closure_put(&d->c->caching);
d->c = NULL;
}
static void bcache_device_attach(struct bcache_device *d, struct cache_set *c,
unsigned int id)
{
d->id = id;
d->c = c;
c->devices[id] = d;
if (id >= c->devices_max_used)
c->devices_max_used = id + 1;
closure_get(&c->caching);
}
static inline int first_minor_to_idx(int first_minor)
{
return (first_minor/BCACHE_MINORS);
}
static inline int idx_to_first_minor(int idx)
{
return (idx * BCACHE_MINORS);
}
static void bcache_device_free(struct bcache_device *d)
{
struct gendisk *disk = d->disk;
lockdep_assert_held(&bch_register_lock);
if (disk)
pr_info("%s stopped\n", disk->disk_name);
else
pr_err("bcache device (NULL gendisk) stopped\n");
if (d->c)
bcache_device_detach(d);
if (disk) {
ida_simple_remove(&bcache_device_idx,
first_minor_to_idx(disk->first_minor));
put_disk(disk);
}
bioset_exit(&d->bio_split);
kvfree(d->full_dirty_stripes);
kvfree(d->stripe_sectors_dirty);
closure_debug_destroy(&d->cl);
}
static int bcache_device_init(struct bcache_device *d, unsigned int block_size,
sector_t sectors, struct block_device *cached_bdev,
const struct block_device_operations *ops)
{
struct request_queue *q;
const size_t max_stripes = min_t(size_t, INT_MAX,
SIZE_MAX / sizeof(atomic_t));
uint64_t n;
int idx;
if (!d->stripe_size)
d->stripe_size = 1 << 31;
n = DIV_ROUND_UP_ULL(sectors, d->stripe_size);
if (!n || n > max_stripes) {
pr_err("nr_stripes too large or invalid: %llu (start sector beyond end of disk?)\n",
n);
return -ENOMEM;
}
d->nr_stripes = n;
n = d->nr_stripes * sizeof(atomic_t);
d->stripe_sectors_dirty = kvzalloc(n, GFP_KERNEL);
if (!d->stripe_sectors_dirty)
return -ENOMEM;
n = BITS_TO_LONGS(d->nr_stripes) * sizeof(unsigned long);
d->full_dirty_stripes = kvzalloc(n, GFP_KERNEL);
if (!d->full_dirty_stripes)
goto out_free_stripe_sectors_dirty;
idx = ida_simple_get(&bcache_device_idx, 0,
BCACHE_DEVICE_IDX_MAX, GFP_KERNEL);
if (idx < 0)
goto out_free_full_dirty_stripes;
if (bioset_init(&d->bio_split, 4, offsetof(struct bbio, bio),
BIOSET_NEED_BVECS|BIOSET_NEED_RESCUER))
goto out_ida_remove;
d->disk = blk_alloc_disk(NUMA_NO_NODE);
if (!d->disk)
goto out_bioset_exit;
set_capacity(d->disk, sectors);
snprintf(d->disk->disk_name, DISK_NAME_LEN, "bcache%i", idx);
d->disk->major = bcache_major;
d->disk->first_minor = idx_to_first_minor(idx);
d->disk->minors = BCACHE_MINORS;
d->disk->fops = ops;
d->disk->private_data = d;
q = d->disk->queue;
q->limits.max_hw_sectors = UINT_MAX;
q->limits.max_sectors = UINT_MAX;
q->limits.max_segment_size = UINT_MAX;
q->limits.max_segments = BIO_MAX_VECS;
blk_queue_max_discard_sectors(q, UINT_MAX);
q->limits.discard_granularity = 512;
q->limits.io_min = block_size;
q->limits.logical_block_size = block_size;
q->limits.physical_block_size = block_size;
if (q->limits.logical_block_size > PAGE_SIZE && cached_bdev) {
/*
* This should only happen with BCACHE_SB_VERSION_BDEV.
* Block/page size is checked for BCACHE_SB_VERSION_CDEV.
*/
pr_info("%s: sb/logical block size (%u) greater than page size (%lu) falling back to device logical block size (%u)\n",
d->disk->disk_name, q->limits.logical_block_size,
PAGE_SIZE, bdev_logical_block_size(cached_bdev));
/* This also adjusts physical block size/min io size if needed */
blk_queue_logical_block_size(q, bdev_logical_block_size(cached_bdev));
}
blk_queue_flag_set(QUEUE_FLAG_NONROT, d->disk->queue);
blk_queue_write_cache(q, true, true);
return 0;
out_bioset_exit:
bioset_exit(&d->bio_split);
out_ida_remove:
ida_simple_remove(&bcache_device_idx, idx);
out_free_full_dirty_stripes:
kvfree(d->full_dirty_stripes);
out_free_stripe_sectors_dirty:
kvfree(d->stripe_sectors_dirty);
return -ENOMEM;
}
/* Cached device */
static void calc_cached_dev_sectors(struct cache_set *c)
{
uint64_t sectors = 0;
struct cached_dev *dc;
list_for_each_entry(dc, &c->cached_devs, list)
sectors += bdev_nr_sectors(dc->bdev);
c->cached_dev_sectors = sectors;
}
#define BACKING_DEV_OFFLINE_TIMEOUT 5
static int cached_dev_status_update(void *arg)
{
struct cached_dev *dc = arg;
struct request_queue *q;
/*
* If this delayed worker is stopping outside, directly quit here.
* dc->io_disable might be set via sysfs interface, so check it
* here too.
*/
while (!kthread_should_stop() && !dc->io_disable) {
q = bdev_get_queue(dc->bdev);
if (blk_queue_dying(q))
dc->offline_seconds++;
else
dc->offline_seconds = 0;
if (dc->offline_seconds >= BACKING_DEV_OFFLINE_TIMEOUT) {
pr_err("%pg: device offline for %d seconds\n",
dc->bdev,
BACKING_DEV_OFFLINE_TIMEOUT);
pr_err("%s: disable I/O request due to backing device offline\n",
dc->disk.name);
dc->io_disable = true;
/* let others know earlier that io_disable is true */
smp_mb();
bcache_device_stop(&dc->disk);
break;
}
schedule_timeout_interruptible(HZ);
}
wait_for_kthread_stop();
return 0;
}
int bch_cached_dev_run(struct cached_dev *dc)
{
int ret = 0;
struct bcache_device *d = &dc->disk;
char *buf = kmemdup_nul(dc->sb.label, SB_LABEL_SIZE, GFP_KERNEL);
char *env[] = {
"DRIVER=bcache",
kasprintf(GFP_KERNEL, "CACHED_UUID=%pU", dc->sb.uuid),
kasprintf(GFP_KERNEL, "CACHED_LABEL=%s", buf ? : ""),
NULL,
};
if (dc->io_disable) {
pr_err("I/O disabled on cached dev %pg\n", dc->bdev);
ret = -EIO;
goto out;
}
if (atomic_xchg(&dc->running, 1)) {
pr_info("cached dev %pg is running already\n", dc->bdev);
ret = -EBUSY;
goto out;
}
if (!d->c &&
BDEV_STATE(&dc->sb) != BDEV_STATE_NONE) {
struct closure cl;
closure_init_stack(&cl);
SET_BDEV_STATE(&dc->sb, BDEV_STATE_STALE);
bch_write_bdev_super(dc, &cl);
closure_sync(&cl);
}
ret = add_disk(d->disk);
if (ret)
goto out;
bd_link_disk_holder(dc->bdev, dc->disk.disk);
/*
* won't show up in the uevent file, use udevadm monitor -e instead
* only class / kset properties are persistent
*/
kobject_uevent_env(&disk_to_dev(d->disk)->kobj, KOBJ_CHANGE, env);
if (sysfs_create_link(&d->kobj, &disk_to_dev(d->disk)->kobj, "dev") ||
sysfs_create_link(&disk_to_dev(d->disk)->kobj,
&d->kobj, "bcache")) {
pr_err("Couldn't create bcache dev <-> disk sysfs symlinks\n");
ret = -ENOMEM;
goto out;
}
dc->status_update_thread = kthread_run(cached_dev_status_update,
dc, "bcache_status_update");
if (IS_ERR(dc->status_update_thread)) {
pr_warn("failed to create bcache_status_update kthread, continue to run without monitoring backing device status\n");
}
out:
kfree(env[1]);
kfree(env[2]);
kfree(buf);
return ret;
}
/*
* If BCACHE_DEV_RATE_DW_RUNNING is set, it means routine of the delayed
* work dc->writeback_rate_update is running. Wait until the routine
* quits (BCACHE_DEV_RATE_DW_RUNNING is clear), then continue to
* cancel it. If BCACHE_DEV_RATE_DW_RUNNING is not clear after time_out
* seconds, give up waiting here and continue to cancel it too.
*/
static void cancel_writeback_rate_update_dwork(struct cached_dev *dc)
{
int time_out = WRITEBACK_RATE_UPDATE_SECS_MAX * HZ;
do {
if (!test_bit(BCACHE_DEV_RATE_DW_RUNNING,
&dc->disk.flags))
break;
time_out--;
schedule_timeout_interruptible(1);
} while (time_out > 0);
if (time_out == 0)
pr_warn("give up waiting for dc->writeback_write_update to quit\n");
cancel_delayed_work_sync(&dc->writeback_rate_update);
}
static void cached_dev_detach_finish(struct work_struct *w)
{
struct cached_dev *dc = container_of(w, struct cached_dev, detach);
struct cache_set *c = dc->disk.c;
BUG_ON(!test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags));
BUG_ON(refcount_read(&dc->count));
if (test_and_clear_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags))
cancel_writeback_rate_update_dwork(dc);
if (!IS_ERR_OR_NULL(dc->writeback_thread)) {
kthread_stop(dc->writeback_thread);
dc->writeback_thread = NULL;
}
mutex_lock(&bch_register_lock);
bcache_device_detach(&dc->disk);
list_move(&dc->list, &uncached_devices);
calc_cached_dev_sectors(c);
clear_bit(BCACHE_DEV_DETACHING, &dc->disk.flags);
clear_bit(BCACHE_DEV_UNLINK_DONE, &dc->disk.flags);
mutex_unlock(&bch_register_lock);
pr_info("Caching disabled for %pg\n", dc->bdev);
/* Drop ref we took in cached_dev_detach() */
closure_put(&dc->disk.cl);
}
void bch_cached_dev_detach(struct cached_dev *dc)
{
lockdep_assert_held(&bch_register_lock);
if (test_bit(BCACHE_DEV_CLOSING, &dc->disk.flags))
return;
if (test_and_set_bit(BCACHE_DEV_DETACHING, &dc->disk.flags))
return;
/*
* Block the device from being closed and freed until we're finished
* detaching
*/
closure_get(&dc->disk.cl);
bch_writeback_queue(dc);
cached_dev_put(dc);
}
int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c,
uint8_t *set_uuid)
{
uint32_t rtime = cpu_to_le32((u32)ktime_get_real_seconds());
struct uuid_entry *u;
struct cached_dev *exist_dc, *t;
int ret = 0;
if ((set_uuid && memcmp(set_uuid, c->set_uuid, 16)) ||
(!set_uuid && memcmp(dc->sb.set_uuid, c->set_uuid, 16)))
return -ENOENT;
if (dc->disk.c) {
pr_err("Can't attach %pg: already attached\n", dc->bdev);
return -EINVAL;
}
if (test_bit(CACHE_SET_STOPPING, &c->flags)) {
pr_err("Can't attach %pg: shutting down\n", dc->bdev);
return -EINVAL;
}
if (dc->sb.block_size < c->cache->sb.block_size) {
/* Will die */
pr_err("Couldn't attach %pg: block size less than set's block size\n",
dc->bdev);
return -EINVAL;
}
/* Check whether already attached */
list_for_each_entry_safe(exist_dc, t, &c->cached_devs, list) {
if (!memcmp(dc->sb.uuid, exist_dc->sb.uuid, 16)) {
pr_err("Tried to attach %pg but duplicate UUID already attached\n",
dc->bdev);
return -EINVAL;
}
}
u = uuid_find(c, dc->sb.uuid);
if (u &&
(BDEV_STATE(&dc->sb) == BDEV_STATE_STALE ||
BDEV_STATE(&dc->sb) == BDEV_STATE_NONE)) {
memcpy(u->uuid, invalid_uuid, 16);
u->invalidated = cpu_to_le32((u32)ktime_get_real_seconds());
u = NULL;
}
if (!u) {
if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) {
pr_err("Couldn't find uuid for %pg in set\n", dc->bdev);
return -ENOENT;
}
u = uuid_find_empty(c);
if (!u) {
pr_err("Not caching %pg, no room for UUID\n", dc->bdev);
return -EINVAL;
}
}
/*
* Deadlocks since we're called via sysfs...
* sysfs_remove_file(&dc->kobj, &sysfs_attach);
*/
if (bch_is_zero(u->uuid, 16)) {
struct closure cl;
closure_init_stack(&cl);
memcpy(u->uuid, dc->sb.uuid, 16);
memcpy(u->label, dc->sb.label, SB_LABEL_SIZE);
u->first_reg = u->last_reg = rtime;
bch_uuid_write(c);
memcpy(dc->sb.set_uuid, c->set_uuid, 16);
SET_BDEV_STATE(&dc->sb, BDEV_STATE_CLEAN);
bch_write_bdev_super(dc, &cl);
closure_sync(&cl);
} else {
u->last_reg = rtime;
bch_uuid_write(c);
}
bcache_device_attach(&dc->disk, c, u - c->uuids);
list_move(&dc->list, &c->cached_devs);
calc_cached_dev_sectors(c);
/*
* dc->c must be set before dc->count != 0 - paired with the mb in
* cached_dev_get()
*/
smp_wmb();
refcount_set(&dc->count, 1);
/* Block writeback thread, but spawn it */
down_write(&dc->writeback_lock);
if (bch_cached_dev_writeback_start(dc)) {
up_write(&dc->writeback_lock);
pr_err("Couldn't start writeback facilities for %s\n",
dc->disk.disk->disk_name);
return -ENOMEM;
}
if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) {
atomic_set(&dc->has_dirty, 1);
bch_writeback_queue(dc);
}
bch_sectors_dirty_init(&dc->disk);
ret = bch_cached_dev_run(dc);
if (ret && (ret != -EBUSY)) {
up_write(&dc->writeback_lock);
/*
* bch_register_lock is held, bcache_device_stop() is not
* able to be directly called. The kthread and kworker
* created previously in bch_cached_dev_writeback_start()
* have to be stopped manually here.
*/
kthread_stop(dc->writeback_thread);
cancel_writeback_rate_update_dwork(dc);
pr_err("Couldn't run cached device %pg\n", dc->bdev);
return ret;
}
bcache_device_link(&dc->disk, c, "bdev");
atomic_inc(&c->attached_dev_nr);
if (bch_has_feature_obso_large_bucket(&(c->cache->sb))) {
pr_err("The obsoleted large bucket layout is unsupported, set the bcache device into read-only\n");
pr_err("Please update to the latest bcache-tools to create the cache device\n");
set_disk_ro(dc->disk.disk, 1);
}
/* Allow the writeback thread to proceed */
up_write(&dc->writeback_lock);
pr_info("Caching %pg as %s on set %pU\n",
dc->bdev,
dc->disk.disk->disk_name,
dc->disk.c->set_uuid);
return 0;
}
/* when dc->disk.kobj released */
void bch_cached_dev_release(struct kobject *kobj)
{
struct cached_dev *dc = container_of(kobj, struct cached_dev,
disk.kobj);
kfree(dc);
module_put(THIS_MODULE);
}
static void cached_dev_free(struct closure *cl)
{
struct cached_dev *dc = container_of(cl, struct cached_dev, disk.cl);
if (test_and_clear_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags))
cancel_writeback_rate_update_dwork(dc);
if (!IS_ERR_OR_NULL(dc->writeback_thread))
kthread_stop(dc->writeback_thread);
if (!IS_ERR_OR_NULL(dc->status_update_thread))
kthread_stop(dc->status_update_thread);
mutex_lock(&bch_register_lock);
if (atomic_read(&dc->running)) {
bd_unlink_disk_holder(dc->bdev, dc->disk.disk);
del_gendisk(dc->disk.disk);
}
bcache_device_free(&dc->disk);
list_del(&dc->list);
mutex_unlock(&bch_register_lock);
if (dc->sb_disk)
put_page(virt_to_page(dc->sb_disk));
if (!IS_ERR_OR_NULL(dc->bdev))
blkdev_put(dc->bdev, dc);
wake_up(&unregister_wait);
kobject_put(&dc->disk.kobj);
}
static void cached_dev_flush(struct closure *cl)
{
struct cached_dev *dc = container_of(cl, struct cached_dev, disk.cl);
struct bcache_device *d = &dc->disk;
mutex_lock(&bch_register_lock);
bcache_device_unlink(d);
mutex_unlock(&bch_register_lock);
bch_cache_accounting_destroy(&dc->accounting);
kobject_del(&d->kobj);
continue_at(cl, cached_dev_free, system_wq);
}
static int cached_dev_init(struct cached_dev *dc, unsigned int block_size)
{
int ret;
struct io *io;
struct request_queue *q = bdev_get_queue(dc->bdev);
__module_get(THIS_MODULE);
INIT_LIST_HEAD(&dc->list);
closure_init(&dc->disk.cl, NULL);
set_closure_fn(&dc->disk.cl, cached_dev_flush, system_wq);
kobject_init(&dc->disk.kobj, &bch_cached_dev_ktype);
INIT_WORK(&dc->detach, cached_dev_detach_finish);
sema_init(&dc->sb_write_mutex, 1);
INIT_LIST_HEAD(&dc->io_lru);
spin_lock_init(&dc->io_lock);
bch_cache_accounting_init(&dc->accounting, &dc->disk.cl);
dc->sequential_cutoff = 4 << 20;
for (io = dc->io; io < dc->io + RECENT_IO; io++) {
list_add(&io->lru, &dc->io_lru);
hlist_add_head(&io->hash, dc->io_hash + RECENT_IO);
}
dc->disk.stripe_size = q->limits.io_opt >> 9;
if (dc->disk.stripe_size)
dc->partial_stripes_expensive =
q->limits.raid_partial_stripes_expensive;
ret = bcache_device_init(&dc->disk, block_size,
bdev_nr_sectors(dc->bdev) - dc->sb.data_offset,
dc->bdev, &bcache_cached_ops);
if (ret)
return ret;
blk_queue_io_opt(dc->disk.disk->queue,
max(queue_io_opt(dc->disk.disk->queue), queue_io_opt(q)));
atomic_set(&dc->io_errors, 0);
dc->io_disable = false;
dc->error_limit = DEFAULT_CACHED_DEV_ERROR_LIMIT;
/* default to auto */
dc->stop_when_cache_set_failed = BCH_CACHED_DEV_STOP_AUTO;
bch_cached_dev_request_init(dc);
bch_cached_dev_writeback_init(dc);
return 0;
}
/* Cached device - bcache superblock */
static int register_bdev(struct cache_sb *sb, struct cache_sb_disk *sb_disk,
struct block_device *bdev,
struct cached_dev *dc)
{
const char *err = "cannot allocate memory";
struct cache_set *c;
int ret = -ENOMEM;
memcpy(&dc->sb, sb, sizeof(struct cache_sb));
dc->bdev = bdev;
dc->sb_disk = sb_disk;
if (cached_dev_init(dc, sb->block_size << 9))
goto err;
err = "error creating kobject";
if (kobject_add(&dc->disk.kobj, bdev_kobj(bdev), "bcache"))
goto err;
if (bch_cache_accounting_add_kobjs(&dc->accounting, &dc->disk.kobj))
goto err;
pr_info("registered backing device %pg\n", dc->bdev);
list_add(&dc->list, &uncached_devices);
/* attach to a matched cache set if it exists */
list_for_each_entry(c, &bch_cache_sets, list)
bch_cached_dev_attach(dc, c, NULL);
if (BDEV_STATE(&dc->sb) == BDEV_STATE_NONE ||
BDEV_STATE(&dc->sb) == BDEV_STATE_STALE) {
err = "failed to run cached device";
ret = bch_cached_dev_run(dc);
if (ret)
goto err;
}
return 0;
err:
pr_notice("error %pg: %s\n", dc->bdev, err);
bcache_device_stop(&dc->disk);
return ret;
}
/* Flash only volumes */
/* When d->kobj released */
void bch_flash_dev_release(struct kobject *kobj)
{
struct bcache_device *d = container_of(kobj, struct bcache_device,
kobj);
kfree(d);
}
static void flash_dev_free(struct closure *cl)
{
struct bcache_device *d = container_of(cl, struct bcache_device, cl);
mutex_lock(&bch_register_lock);
atomic_long_sub(bcache_dev_sectors_dirty(d),
&d->c->flash_dev_dirty_sectors);
del_gendisk(d->disk);
bcache_device_free(d);
mutex_unlock(&bch_register_lock);
kobject_put(&d->kobj);
}
static void flash_dev_flush(struct closure *cl)
{
struct bcache_device *d = container_of(cl, struct bcache_device, cl);
mutex_lock(&bch_register_lock);
bcache_device_unlink(d);
mutex_unlock(&bch_register_lock);
kobject_del(&d->kobj);
continue_at(cl, flash_dev_free, system_wq);
}
static int flash_dev_run(struct cache_set *c, struct uuid_entry *u)
{
int err = -ENOMEM;
struct bcache_device *d = kzalloc(sizeof(struct bcache_device),
GFP_KERNEL);
if (!d)
goto err_ret;
closure_init(&d->cl, NULL);
set_closure_fn(&d->cl, flash_dev_flush, system_wq);
kobject_init(&d->kobj, &bch_flash_dev_ktype);
if (bcache_device_init(d, block_bytes(c->cache), u->sectors,
NULL, &bcache_flash_ops))
goto err;
bcache_device_attach(d, c, u - c->uuids);
bch_sectors_dirty_init(d);
bch_flash_dev_request_init(d);
err = add_disk(d->disk);
if (err)
goto err;
err = kobject_add(&d->kobj, &disk_to_dev(d->disk)->kobj, "bcache");
if (err)
goto err;
bcache_device_link(d, c, "volume");
if (bch_has_feature_obso_large_bucket(&c->cache->sb)) {
pr_err("The obsoleted large bucket layout is unsupported, set the bcache device into read-only\n");
pr_err("Please update to the latest bcache-tools to create the cache device\n");
set_disk_ro(d->disk, 1);
}
return 0;
err:
kobject_put(&d->kobj);
err_ret:
return err;
}
static int flash_devs_run(struct cache_set *c)
{
int ret = 0;
struct uuid_entry *u;
for (u = c->uuids;
u < c->uuids + c->nr_uuids && !ret;
u++)
if (UUID_FLASH_ONLY(u))
ret = flash_dev_run(c, u);
return ret;
}
int bch_flash_dev_create(struct cache_set *c, uint64_t size)
{
struct uuid_entry *u;
if (test_bit(CACHE_SET_STOPPING, &c->flags))
return -EINTR;
if (!test_bit(CACHE_SET_RUNNING, &c->flags))
return -EPERM;
u = uuid_find_empty(c);
if (!u) {
pr_err("Can't create volume, no room for UUID\n");
return -EINVAL;
}
get_random_bytes(u->uuid, 16);
memset(u->label, 0, 32);
u->first_reg = u->last_reg = cpu_to_le32((u32)ktime_get_real_seconds());
SET_UUID_FLASH_ONLY(u, 1);
u->sectors = size >> 9;
bch_uuid_write(c);
return flash_dev_run(c, u);
}
bool bch_cached_dev_error(struct cached_dev *dc)
{
if (!dc || test_bit(BCACHE_DEV_CLOSING, &dc->disk.flags))
return false;
dc->io_disable = true;
/* make others know io_disable is true earlier */
smp_mb();
pr_err("stop %s: too many IO errors on backing device %pg\n",
dc->disk.disk->disk_name, dc->bdev);
bcache_device_stop(&dc->disk);
return true;
}
/* Cache set */
__printf(2, 3)
bool bch_cache_set_error(struct cache_set *c, const char *fmt, ...)
{
struct va_format vaf;
va_list args;
if (c->on_error != ON_ERROR_PANIC &&
test_bit(CACHE_SET_STOPPING, &c->flags))
return false;
if (test_and_set_bit(CACHE_SET_IO_DISABLE, &c->flags))
pr_info("CACHE_SET_IO_DISABLE already set\n");
/*
* XXX: we can be called from atomic context
* acquire_console_sem();
*/
va_start(args, fmt);
vaf.fmt = fmt;
vaf.va = &args;
pr_err("error on %pU: %pV, disabling caching\n",
c->set_uuid, &vaf);
va_end(args);
if (c->on_error == ON_ERROR_PANIC)
panic("panic forced after error\n");
bch_cache_set_unregister(c);
return true;
}
/* When c->kobj released */
void bch_cache_set_release(struct kobject *kobj)
{
struct cache_set *c = container_of(kobj, struct cache_set, kobj);
kfree(c);
module_put(THIS_MODULE);
}
static void cache_set_free(struct closure *cl)
{
struct cache_set *c = container_of(cl, struct cache_set, cl);
struct cache *ca;
debugfs_remove(c->debug);
bch_open_buckets_free(c);
bch_btree_cache_free(c);
bch_journal_free(c);
mutex_lock(&bch_register_lock);
bch_bset_sort_state_free(&c->sort);
free_pages((unsigned long) c->uuids, ilog2(meta_bucket_pages(&c->cache->sb)));
ca = c->cache;
if (ca) {
ca->set = NULL;
c->cache = NULL;
kobject_put(&ca->kobj);
}
if (c->moving_gc_wq)
destroy_workqueue(c->moving_gc_wq);
bioset_exit(&c->bio_split);
mempool_exit(&c->fill_iter);
mempool_exit(&c->bio_meta);
mempool_exit(&c->search);
kfree(c->devices);
list_del(&c->list);
mutex_unlock(&bch_register_lock);
pr_info("Cache set %pU unregistered\n", c->set_uuid);
wake_up(&unregister_wait);
closure_debug_destroy(&c->cl);
kobject_put(&c->kobj);
}
static void cache_set_flush(struct closure *cl)
{
struct cache_set *c = container_of(cl, struct cache_set, caching);
struct cache *ca = c->cache;
struct btree *b;
bch_cache_accounting_destroy(&c->accounting);
kobject_put(&c->internal);
kobject_del(&c->kobj);
if (!IS_ERR_OR_NULL(c->gc_thread))
kthread_stop(c->gc_thread);
if (!IS_ERR(c->root))
list_add(&c->root->list, &c->btree_cache);
/*
* Avoid flushing cached nodes if cache set is retiring
* due to too many I/O errors detected.
*/
if (!test_bit(CACHE_SET_IO_DISABLE, &c->flags))
list_for_each_entry(b, &c->btree_cache, list) {
mutex_lock(&b->write_lock);
if (btree_node_dirty(b))
__bch_btree_node_write(b, NULL);
mutex_unlock(&b->write_lock);
}
if (ca->alloc_thread)
kthread_stop(ca->alloc_thread);
if (c->journal.cur) {
cancel_delayed_work_sync(&c->journal.work);
/* flush last journal entry if needed */
c->journal.work.work.func(&c->journal.work.work);
}
closure_return(cl);
}
/*
* This function is only called when CACHE_SET_IO_DISABLE is set, which means
* cache set is unregistering due to too many I/O errors. In this condition,
* the bcache device might be stopped, it depends on stop_when_cache_set_failed
* value and whether the broken cache has dirty data:
*
* dc->stop_when_cache_set_failed dc->has_dirty stop bcache device
* BCH_CACHED_STOP_AUTO 0 NO
* BCH_CACHED_STOP_AUTO 1 YES
* BCH_CACHED_DEV_STOP_ALWAYS 0 YES
* BCH_CACHED_DEV_STOP_ALWAYS 1 YES
*
* The expected behavior is, if stop_when_cache_set_failed is configured to
* "auto" via sysfs interface, the bcache device will not be stopped if the
* backing device is clean on the broken cache device.
*/
static void conditional_stop_bcache_device(struct cache_set *c,
struct bcache_device *d,
struct cached_dev *dc)
{
if (dc->stop_when_cache_set_failed == BCH_CACHED_DEV_STOP_ALWAYS) {
pr_warn("stop_when_cache_set_failed of %s is \"always\", stop it for failed cache set %pU.\n",
d->disk->disk_name, c->set_uuid);
bcache_device_stop(d);
} else if (atomic_read(&dc->has_dirty)) {
/*
* dc->stop_when_cache_set_failed == BCH_CACHED_STOP_AUTO
* and dc->has_dirty == 1
*/
pr_warn("stop_when_cache_set_failed of %s is \"auto\" and cache is dirty, stop it to avoid potential data corruption.\n",
d->disk->disk_name);
/*
* There might be a small time gap that cache set is
* released but bcache device is not. Inside this time
* gap, regular I/O requests will directly go into
* backing device as no cache set attached to. This
* behavior may also introduce potential inconsistence
* data in writeback mode while cache is dirty.
* Therefore before calling bcache_device_stop() due
* to a broken cache device, dc->io_disable should be
* explicitly set to true.
*/
dc->io_disable = true;
/* make others know io_disable is true earlier */
smp_mb();
bcache_device_stop(d);
} else {
/*
* dc->stop_when_cache_set_failed == BCH_CACHED_STOP_AUTO
* and dc->has_dirty == 0
*/
pr_warn("stop_when_cache_set_failed of %s is \"auto\" and cache is clean, keep it alive.\n",
d->disk->disk_name);
}
}
static void __cache_set_unregister(struct closure *cl)
{
struct cache_set *c = container_of(cl, struct cache_set, caching);
struct cached_dev *dc;
struct bcache_device *d;
size_t i;
mutex_lock(&bch_register_lock);
for (i = 0; i < c->devices_max_used; i++) {
d = c->devices[i];
if (!d)
continue;
if (!UUID_FLASH_ONLY(&c->uuids[i]) &&
test_bit(CACHE_SET_UNREGISTERING, &c->flags)) {
dc = container_of(d, struct cached_dev, disk);
bch_cached_dev_detach(dc);
if (test_bit(CACHE_SET_IO_DISABLE, &c->flags))
conditional_stop_bcache_device(c, d, dc);
} else {
bcache_device_stop(d);
}
}
mutex_unlock(&bch_register_lock);
continue_at(cl, cache_set_flush, system_wq);
}
void bch_cache_set_stop(struct cache_set *c)
{
if (!test_and_set_bit(CACHE_SET_STOPPING, &c->flags))
/* closure_fn set to __cache_set_unregister() */
closure_queue(&c->caching);
}
void bch_cache_set_unregister(struct cache_set *c)
{
set_bit(CACHE_SET_UNREGISTERING, &c->flags);
bch_cache_set_stop(c);
}
#define alloc_meta_bucket_pages(gfp, sb) \
((void *) __get_free_pages(__GFP_ZERO|__GFP_COMP|gfp, ilog2(meta_bucket_pages(sb))))
struct cache_set *bch_cache_set_alloc(struct cache_sb *sb)
{
int iter_size;
struct cache *ca = container_of(sb, struct cache, sb);
struct cache_set *c = kzalloc(sizeof(struct cache_set), GFP_KERNEL);
if (!c)
return NULL;
__module_get(THIS_MODULE);
closure_init(&c->cl, NULL);
set_closure_fn(&c->cl, cache_set_free, system_wq);
closure_init(&c->caching, &c->cl);
set_closure_fn(&c->caching, __cache_set_unregister, system_wq);
/* Maybe create continue_at_noreturn() and use it here? */
closure_set_stopped(&c->cl);
closure_put(&c->cl);
kobject_init(&c->kobj, &bch_cache_set_ktype);
kobject_init(&c->internal, &bch_cache_set_internal_ktype);
bch_cache_accounting_init(&c->accounting, &c->cl);
memcpy(c->set_uuid, sb->set_uuid, 16);
c->cache = ca;
c->cache->set = c;
c->bucket_bits = ilog2(sb->bucket_size);
c->block_bits = ilog2(sb->block_size);
c->nr_uuids = meta_bucket_bytes(sb) / sizeof(struct uuid_entry);
c->devices_max_used = 0;
atomic_set(&c->attached_dev_nr, 0);
c->btree_pages = meta_bucket_pages(sb);
if (c->btree_pages > BTREE_MAX_PAGES)
c->btree_pages = max_t(int, c->btree_pages / 4,
BTREE_MAX_PAGES);
sema_init(&c->sb_write_mutex, 1);
mutex_init(&c->bucket_lock);
init_waitqueue_head(&c->btree_cache_wait);
spin_lock_init(&c->btree_cannibalize_lock);
init_waitqueue_head(&c->bucket_wait);
init_waitqueue_head(&c->gc_wait);
sema_init(&c->uuid_write_mutex, 1);
spin_lock_init(&c->btree_gc_time.lock);
spin_lock_init(&c->btree_split_time.lock);
spin_lock_init(&c->btree_read_time.lock);
bch_moving_init_cache_set(c);
INIT_LIST_HEAD(&c->list);
INIT_LIST_HEAD(&c->cached_devs);
INIT_LIST_HEAD(&c->btree_cache);
INIT_LIST_HEAD(&c->btree_cache_freeable);
INIT_LIST_HEAD(&c->btree_cache_freed);
INIT_LIST_HEAD(&c->data_buckets);
iter_size = ((meta_bucket_pages(sb) * PAGE_SECTORS) / sb->block_size + 1) *
sizeof(struct btree_iter_set);
c->devices = kcalloc(c->nr_uuids, sizeof(void *), GFP_KERNEL);
if (!c->devices)
goto err;
if (mempool_init_slab_pool(&c->search, 32, bch_search_cache))
goto err;
if (mempool_init_kmalloc_pool(&c->bio_meta, 2,
sizeof(struct bbio) +
sizeof(struct bio_vec) * meta_bucket_pages(sb)))
goto err;
if (mempool_init_kmalloc_pool(&c->fill_iter, 1, iter_size))
goto err;
if (bioset_init(&c->bio_split, 4, offsetof(struct bbio, bio),
BIOSET_NEED_RESCUER))
goto err;
c->uuids = alloc_meta_bucket_pages(GFP_KERNEL, sb);
if (!c->uuids)
goto err;
c->moving_gc_wq = alloc_workqueue("bcache_gc", WQ_MEM_RECLAIM, 0);
if (!c->moving_gc_wq)
goto err;
if (bch_journal_alloc(c))
goto err;
if (bch_btree_cache_alloc(c))
goto err;
if (bch_open_buckets_alloc(c))
goto err;
if (bch_bset_sort_state_init(&c->sort, ilog2(c->btree_pages)))
goto err;
c->congested_read_threshold_us = 2000;
c->congested_write_threshold_us = 20000;
c->error_limit = DEFAULT_IO_ERROR_LIMIT;
c->idle_max_writeback_rate_enabled = 1;
WARN_ON(test_and_clear_bit(CACHE_SET_IO_DISABLE, &c->flags));
return c;
err:
bch_cache_set_unregister(c);
return NULL;
}
static int run_cache_set(struct cache_set *c)
{
const char *err = "cannot allocate memory";
struct cached_dev *dc, *t;
struct cache *ca = c->cache;
struct closure cl;
LIST_HEAD(journal);
struct journal_replay *l;
closure_init_stack(&cl);
c->nbuckets = ca->sb.nbuckets;
set_gc_sectors(c);
if (CACHE_SYNC(&c->cache->sb)) {
struct bkey *k;
struct jset *j;
err = "cannot allocate memory for journal";
if (bch_journal_read(c, &journal))
goto err;
pr_debug("btree_journal_read() done\n");
err = "no journal entries found";
if (list_empty(&journal))
goto err;
j = &list_entry(journal.prev, struct journal_replay, list)->j;
err = "IO error reading priorities";
if (prio_read(ca, j->prio_bucket[ca->sb.nr_this_dev]))
goto err;
/*
* If prio_read() fails it'll call cache_set_error and we'll
* tear everything down right away, but if we perhaps checked
* sooner we could avoid journal replay.
*/
k = &j->btree_root;
err = "bad btree root";
if (__bch_btree_ptr_invalid(c, k))
goto err;
err = "error reading btree root";
c->root = bch_btree_node_get(c, NULL, k,
j->btree_level,
true, NULL);
if (IS_ERR_OR_NULL(c->root))
goto err;
list_del_init(&c->root->list);
rw_unlock(true, c->root);
err = uuid_read(c, j, &cl);
if (err)
goto err;
err = "error in recovery";
if (bch_btree_check(c))
goto err;
bch_journal_mark(c, &journal);
bch_initial_gc_finish(c);
pr_debug("btree_check() done\n");
/*
* bcache_journal_next() can't happen sooner, or
* btree_gc_finish() will give spurious errors about last_gc >
* gc_gen - this is a hack but oh well.
*/
bch_journal_next(&c->journal);
err = "error starting allocator thread";
if (bch_cache_allocator_start(ca))
goto err;
/*
* First place it's safe to allocate: btree_check() and
* btree_gc_finish() have to run before we have buckets to
* allocate, and bch_bucket_alloc_set() might cause a journal
* entry to be written so bcache_journal_next() has to be called
* first.
*
* If the uuids were in the old format we have to rewrite them
* before the next journal entry is written:
*/
if (j->version < BCACHE_JSET_VERSION_UUID)
__uuid_write(c);
err = "bcache: replay journal failed";
if (bch_journal_replay(c, &journal))
goto err;
} else {
unsigned int j;
pr_notice("invalidating existing data\n");
ca->sb.keys = clamp_t(int, ca->sb.nbuckets >> 7,
2, SB_JOURNAL_BUCKETS);
for (j = 0; j < ca->sb.keys; j++)
ca->sb.d[j] = ca->sb.first_bucket + j;
bch_initial_gc_finish(c);
err = "error starting allocator thread";
if (bch_cache_allocator_start(ca))
goto err;
mutex_lock(&c->bucket_lock);
bch_prio_write(ca, true);
mutex_unlock(&c->bucket_lock);
err = "cannot allocate new UUID bucket";
if (__uuid_write(c))
goto err;
err = "cannot allocate new btree root";
c->root = __bch_btree_node_alloc(c, NULL, 0, true, NULL);
if (IS_ERR(c->root))
goto err;
mutex_lock(&c->root->write_lock);
bkey_copy_key(&c->root->key, &MAX_KEY);
bch_btree_node_write(c->root, &cl);
mutex_unlock(&c->root->write_lock);
bch_btree_set_root(c->root);
rw_unlock(true, c->root);
/*
* We don't want to write the first journal entry until
* everything is set up - fortunately journal entries won't be
* written until the SET_CACHE_SYNC() here:
*/
SET_CACHE_SYNC(&c->cache->sb, true);
bch_journal_next(&c->journal);
bch_journal_meta(c, &cl);
}
err = "error starting gc thread";
if (bch_gc_thread_start(c))
goto err;
closure_sync(&cl);
c->cache->sb.last_mount = (u32)ktime_get_real_seconds();
bcache_write_super(c);
if (bch_has_feature_obso_large_bucket(&c->cache->sb))
pr_err("Detect obsoleted large bucket layout, all attached bcache device will be read-only\n");
list_for_each_entry_safe(dc, t, &uncached_devices, list)
bch_cached_dev_attach(dc, c, NULL);
flash_devs_run(c);
bch_journal_space_reserve(&c->journal);
set_bit(CACHE_SET_RUNNING, &c->flags);
return 0;
err:
while (!list_empty(&journal)) {
l = list_first_entry(&journal, struct journal_replay, list);
list_del(&l->list);
kfree(l);
}
closure_sync(&cl);
bch_cache_set_error(c, "%s", err);
return -EIO;
}
static const char *register_cache_set(struct cache *ca)
{
char buf[12];
const char *err = "cannot allocate memory";
struct cache_set *c;
list_for_each_entry(c, &bch_cache_sets, list)
if (!memcmp(c->set_uuid, ca->sb.set_uuid, 16)) {
if (c->cache)
return "duplicate cache set member";
goto found;
}
c = bch_cache_set_alloc(&ca->sb);
if (!c)
return err;
err = "error creating kobject";
if (kobject_add(&c->kobj, bcache_kobj, "%pU", c->set_uuid) ||
kobject_add(&c->internal, &c->kobj, "internal"))
goto err;
if (bch_cache_accounting_add_kobjs(&c->accounting, &c->kobj))
goto err;
bch_debug_init_cache_set(c);
list_add(&c->list, &bch_cache_sets);
found:
sprintf(buf, "cache%i", ca->sb.nr_this_dev);
if (sysfs_create_link(&ca->kobj, &c->kobj, "set") ||
sysfs_create_link(&c->kobj, &ca->kobj, buf))
goto err;
kobject_get(&ca->kobj);
ca->set = c;
ca->set->cache = ca;
err = "failed to run cache set";
if (run_cache_set(c) < 0)
goto err;
return NULL;
err:
bch_cache_set_unregister(c);
return err;
}
/* Cache device */
/* When ca->kobj released */
void bch_cache_release(struct kobject *kobj)
{
struct cache *ca = container_of(kobj, struct cache, kobj);
unsigned int i;
if (ca->set) {
BUG_ON(ca->set->cache != ca);
ca->set->cache = NULL;
}
free_pages((unsigned long) ca->disk_buckets, ilog2(meta_bucket_pages(&ca->sb)));
kfree(ca->prio_buckets);
vfree(ca->buckets);
free_heap(&ca->heap);
free_fifo(&ca->free_inc);
for (i = 0; i < RESERVE_NR; i++)
free_fifo(&ca->free[i]);
if (ca->sb_disk)
put_page(virt_to_page(ca->sb_disk));
if (!IS_ERR_OR_NULL(ca->bdev))
blkdev_put(ca->bdev, ca);
kfree(ca);
module_put(THIS_MODULE);
}
static int cache_alloc(struct cache *ca)
{
size_t free;
size_t btree_buckets;
struct bucket *b;
int ret = -ENOMEM;
const char *err = NULL;
__module_get(THIS_MODULE);
kobject_init(&ca->kobj, &bch_cache_ktype);
bio_init(&ca->journal.bio, NULL, ca->journal.bio.bi_inline_vecs, 8, 0);
/*
* when ca->sb.njournal_buckets is not zero, journal exists,
* and in bch_journal_replay(), tree node may split,
* so bucket of RESERVE_BTREE type is needed,
* the worst situation is all journal buckets are valid journal,
* and all the keys need to replay,
* so the number of RESERVE_BTREE type buckets should be as much
* as journal buckets
*/
btree_buckets = ca->sb.njournal_buckets ?: 8;
free = roundup_pow_of_two(ca->sb.nbuckets) >> 10;
if (!free) {
ret = -EPERM;
err = "ca->sb.nbuckets is too small";
goto err_free;
}
if (!init_fifo(&ca->free[RESERVE_BTREE], btree_buckets,
GFP_KERNEL)) {
err = "ca->free[RESERVE_BTREE] alloc failed";
goto err_btree_alloc;
}
if (!init_fifo_exact(&ca->free[RESERVE_PRIO], prio_buckets(ca),
GFP_KERNEL)) {
err = "ca->free[RESERVE_PRIO] alloc failed";
goto err_prio_alloc;
}
if (!init_fifo(&ca->free[RESERVE_MOVINGGC], free, GFP_KERNEL)) {
err = "ca->free[RESERVE_MOVINGGC] alloc failed";
goto err_movinggc_alloc;
}
if (!init_fifo(&ca->free[RESERVE_NONE], free, GFP_KERNEL)) {
err = "ca->free[RESERVE_NONE] alloc failed";
goto err_none_alloc;
}
if (!init_fifo(&ca->free_inc, free << 2, GFP_KERNEL)) {
err = "ca->free_inc alloc failed";
goto err_free_inc_alloc;
}
if (!init_heap(&ca->heap, free << 3, GFP_KERNEL)) {
err = "ca->heap alloc failed";
goto err_heap_alloc;
}
ca->buckets = vzalloc(array_size(sizeof(struct bucket),
ca->sb.nbuckets));
if (!ca->buckets) {
err = "ca->buckets alloc failed";
goto err_buckets_alloc;
}
ca->prio_buckets = kzalloc(array3_size(sizeof(uint64_t),
prio_buckets(ca), 2),
GFP_KERNEL);
if (!ca->prio_buckets) {
err = "ca->prio_buckets alloc failed";
goto err_prio_buckets_alloc;
}
ca->disk_buckets = alloc_meta_bucket_pages(GFP_KERNEL, &ca->sb);
if (!ca->disk_buckets) {
err = "ca->disk_buckets alloc failed";
goto err_disk_buckets_alloc;
}
ca->prio_last_buckets = ca->prio_buckets + prio_buckets(ca);
for_each_bucket(b, ca)
atomic_set(&b->pin, 0);
return 0;
err_disk_buckets_alloc:
kfree(ca->prio_buckets);
err_prio_buckets_alloc:
vfree(ca->buckets);
err_buckets_alloc:
free_heap(&ca->heap);
err_heap_alloc:
free_fifo(&ca->free_inc);
err_free_inc_alloc:
free_fifo(&ca->free[RESERVE_NONE]);
err_none_alloc:
free_fifo(&ca->free[RESERVE_MOVINGGC]);
err_movinggc_alloc:
free_fifo(&ca->free[RESERVE_PRIO]);
err_prio_alloc:
free_fifo(&ca->free[RESERVE_BTREE]);
err_btree_alloc:
err_free:
module_put(THIS_MODULE);
if (err)
pr_notice("error %pg: %s\n", ca->bdev, err);
return ret;
}
static int register_cache(struct cache_sb *sb, struct cache_sb_disk *sb_disk,
struct block_device *bdev, struct cache *ca)
{
const char *err = NULL; /* must be set for any error case */
int ret = 0;
memcpy(&ca->sb, sb, sizeof(struct cache_sb));
ca->bdev = bdev;
ca->sb_disk = sb_disk;
if (bdev_max_discard_sectors((bdev)))
ca->discard = CACHE_DISCARD(&ca->sb);
ret = cache_alloc(ca);
if (ret != 0) {
/*
* If we failed here, it means ca->kobj is not initialized yet,
* kobject_put() won't be called and there is no chance to
* call blkdev_put() to bdev in bch_cache_release(). So we
* explicitly call blkdev_put() here.
*/
blkdev_put(bdev, ca);
if (ret == -ENOMEM)
err = "cache_alloc(): -ENOMEM";
else if (ret == -EPERM)
err = "cache_alloc(): cache device is too small";
else
err = "cache_alloc(): unknown error";
goto err;
}
if (kobject_add(&ca->kobj, bdev_kobj(bdev), "bcache")) {
err = "error calling kobject_add";
ret = -ENOMEM;
goto out;
}
mutex_lock(&bch_register_lock);
err = register_cache_set(ca);
mutex_unlock(&bch_register_lock);
if (err) {
ret = -ENODEV;
goto out;
}
pr_info("registered cache device %pg\n", ca->bdev);
out:
kobject_put(&ca->kobj);
err:
if (err)
pr_notice("error %pg: %s\n", ca->bdev, err);
return ret;
}
/* Global interfaces/init */
static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
const char *buffer, size_t size);
static ssize_t bch_pending_bdevs_cleanup(struct kobject *k,
struct kobj_attribute *attr,
const char *buffer, size_t size);
kobj_attribute_write(register, register_bcache);
kobj_attribute_write(register_quiet, register_bcache);
kobj_attribute_write(pendings_cleanup, bch_pending_bdevs_cleanup);
static bool bch_is_open_backing(dev_t dev)
{
struct cache_set *c, *tc;
struct cached_dev *dc, *t;
list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
list_for_each_entry_safe(dc, t, &c->cached_devs, list)
if (dc->bdev->bd_dev == dev)
return true;
list_for_each_entry_safe(dc, t, &uncached_devices, list)
if (dc->bdev->bd_dev == dev)
return true;
return false;
}
static bool bch_is_open_cache(dev_t dev)
{
struct cache_set *c, *tc;
list_for_each_entry_safe(c, tc, &bch_cache_sets, list) {
struct cache *ca = c->cache;
if (ca->bdev->bd_dev == dev)
return true;
}
return false;
}
static bool bch_is_open(dev_t dev)
{
return bch_is_open_cache(dev) || bch_is_open_backing(dev);
}
struct async_reg_args {
struct delayed_work reg_work;
char *path;
struct cache_sb *sb;
struct cache_sb_disk *sb_disk;
struct block_device *bdev;
void *holder;
};
static void register_bdev_worker(struct work_struct *work)
{
int fail = false;
struct async_reg_args *args =
container_of(work, struct async_reg_args, reg_work.work);
mutex_lock(&bch_register_lock);
if (register_bdev(args->sb, args->sb_disk, args->bdev, args->holder)
< 0)
fail = true;
mutex_unlock(&bch_register_lock);
if (fail)
pr_info("error %s: fail to register backing device\n",
args->path);
kfree(args->sb);
kfree(args->path);
kfree(args);
module_put(THIS_MODULE);
}
static void register_cache_worker(struct work_struct *work)
{
int fail = false;
struct async_reg_args *args =
container_of(work, struct async_reg_args, reg_work.work);
/* blkdev_put() will be called in bch_cache_release() */
if (register_cache(args->sb, args->sb_disk, args->bdev, args->holder))
fail = true;
if (fail)
pr_info("error %s: fail to register cache device\n",
args->path);
kfree(args->sb);
kfree(args->path);
kfree(args);
module_put(THIS_MODULE);
}
static void register_device_async(struct async_reg_args *args)
{
if (SB_IS_BDEV(args->sb))
INIT_DELAYED_WORK(&args->reg_work, register_bdev_worker);
else
INIT_DELAYED_WORK(&args->reg_work, register_cache_worker);
/* 10 jiffies is enough for a delay */
queue_delayed_work(system_wq, &args->reg_work, 10);
}
static void *alloc_holder_object(struct cache_sb *sb)
{
if (SB_IS_BDEV(sb))
return kzalloc(sizeof(struct cached_dev), GFP_KERNEL);
return kzalloc(sizeof(struct cache), GFP_KERNEL);
}
static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
const char *buffer, size_t size)
{
const char *err;
char *path = NULL;
struct cache_sb *sb;
struct cache_sb_disk *sb_disk;
struct block_device *bdev, *bdev2;
void *holder = NULL;
ssize_t ret;
bool async_registration = false;
bool quiet = false;
#ifdef CONFIG_BCACHE_ASYNC_REGISTRATION
async_registration = true;
#endif
ret = -EBUSY;
err = "failed to reference bcache module";
if (!try_module_get(THIS_MODULE))
goto out;
/* For latest state of bcache_is_reboot */
smp_mb();
err = "bcache is in reboot";
if (bcache_is_reboot)
goto out_module_put;
ret = -ENOMEM;
err = "cannot allocate memory";
path = kstrndup(buffer, size, GFP_KERNEL);
if (!path)
goto out_module_put;
sb = kmalloc(sizeof(struct cache_sb), GFP_KERNEL);
if (!sb)
goto out_free_path;
ret = -EINVAL;
err = "failed to open device";
bdev = blkdev_get_by_path(strim(path), BLK_OPEN_READ, NULL, NULL);
if (IS_ERR(bdev))
goto out_free_sb;
err = "failed to set blocksize";
if (set_blocksize(bdev, 4096))
goto out_blkdev_put;
err = read_super(sb, bdev, &sb_disk);
if (err)
goto out_blkdev_put;
holder = alloc_holder_object(sb);
if (!holder) {
ret = -ENOMEM;
err = "cannot allocate memory";
goto out_put_sb_page;
}
/* Now reopen in exclusive mode with proper holder */
bdev2 = blkdev_get_by_dev(bdev->bd_dev, BLK_OPEN_READ | BLK_OPEN_WRITE,
holder, NULL);
blkdev_put(bdev, NULL);
bdev = bdev2;
if (IS_ERR(bdev)) {
ret = PTR_ERR(bdev);
bdev = NULL;
if (ret == -EBUSY) {
dev_t dev;
mutex_lock(&bch_register_lock);
if (lookup_bdev(strim(path), &dev) == 0 &&
bch_is_open(dev))
err = "device already registered";
else
err = "device busy";
mutex_unlock(&bch_register_lock);
if (attr == &ksysfs_register_quiet) {
quiet = true;
ret = size;
}
}
goto out_free_holder;
}
err = "failed to register device";
if (async_registration) {
/* register in asynchronous way */
struct async_reg_args *args =
kzalloc(sizeof(struct async_reg_args), GFP_KERNEL);
if (!args) {
ret = -ENOMEM;
err = "cannot allocate memory";
goto out_free_holder;
}
args->path = path;
args->sb = sb;
args->sb_disk = sb_disk;
args->bdev = bdev;
args->holder = holder;
register_device_async(args);
/* No wait and returns to user space */
goto async_done;
}
if (SB_IS_BDEV(sb)) {
mutex_lock(&bch_register_lock);
ret = register_bdev(sb, sb_disk, bdev, holder);
mutex_unlock(&bch_register_lock);
/* blkdev_put() will be called in cached_dev_free() */
if (ret < 0)
goto out_free_sb;
} else {
/* blkdev_put() will be called in bch_cache_release() */
ret = register_cache(sb, sb_disk, bdev, holder);
if (ret)
goto out_free_sb;
}
kfree(sb);
kfree(path);
module_put(THIS_MODULE);
async_done:
return size;
out_free_holder:
kfree(holder);
out_put_sb_page:
put_page(virt_to_page(sb_disk));
out_blkdev_put:
if (bdev)
blkdev_put(bdev, holder);
out_free_sb:
kfree(sb);
out_free_path:
kfree(path);
path = NULL;
out_module_put:
module_put(THIS_MODULE);
out:
if (!quiet)
pr_info("error %s: %s\n", path?path:"", err);
return ret;
}
struct pdev {
struct list_head list;
struct cached_dev *dc;
};
static ssize_t bch_pending_bdevs_cleanup(struct kobject *k,
struct kobj_attribute *attr,
const char *buffer,
size_t size)
{
LIST_HEAD(pending_devs);
ssize_t ret = size;
struct cached_dev *dc, *tdc;
struct pdev *pdev, *tpdev;
struct cache_set *c, *tc;
mutex_lock(&bch_register_lock);
list_for_each_entry_safe(dc, tdc, &uncached_devices, list) {
pdev = kmalloc(sizeof(struct pdev), GFP_KERNEL);
if (!pdev)
break;
pdev->dc = dc;
list_add(&pdev->list, &pending_devs);
}
list_for_each_entry_safe(pdev, tpdev, &pending_devs, list) {
char *pdev_set_uuid = pdev->dc->sb.set_uuid;
list_for_each_entry_safe(c, tc, &bch_cache_sets, list) {
char *set_uuid = c->set_uuid;
if (!memcmp(pdev_set_uuid, set_uuid, 16)) {
list_del(&pdev->list);
kfree(pdev);
break;
}
}
}
mutex_unlock(&bch_register_lock);
list_for_each_entry_safe(pdev, tpdev, &pending_devs, list) {
pr_info("delete pdev %p\n", pdev);
list_del(&pdev->list);
bcache_device_stop(&pdev->dc->disk);
kfree(pdev);
}
return ret;
}
static int bcache_reboot(struct notifier_block *n, unsigned long code, void *x)
{
if (bcache_is_reboot)
return NOTIFY_DONE;
if (code == SYS_DOWN ||
code == SYS_HALT ||
code == SYS_POWER_OFF) {
DEFINE_WAIT(wait);
unsigned long start = jiffies;
bool stopped = false;
struct cache_set *c, *tc;
struct cached_dev *dc, *tdc;
mutex_lock(&bch_register_lock);
if (bcache_is_reboot)
goto out;
/* New registration is rejected since now */
bcache_is_reboot = true;
/*
* Make registering caller (if there is) on other CPU
* core know bcache_is_reboot set to true earlier
*/
smp_mb();
if (list_empty(&bch_cache_sets) &&
list_empty(&uncached_devices))
goto out;
mutex_unlock(&bch_register_lock);
pr_info("Stopping all devices:\n");
/*
* The reason bch_register_lock is not held to call
* bch_cache_set_stop() and bcache_device_stop() is to
* avoid potential deadlock during reboot, because cache
* set or bcache device stopping process will acquire
* bch_register_lock too.
*
* We are safe here because bcache_is_reboot sets to
* true already, register_bcache() will reject new
* registration now. bcache_is_reboot also makes sure
* bcache_reboot() won't be re-entered on by other thread,
* so there is no race in following list iteration by
* list_for_each_entry_safe().
*/
list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
bch_cache_set_stop(c);
list_for_each_entry_safe(dc, tdc, &uncached_devices, list)
bcache_device_stop(&dc->disk);
/*
* Give an early chance for other kthreads and
* kworkers to stop themselves
*/
schedule();
/* What's a condition variable? */
while (1) {
long timeout = start + 10 * HZ - jiffies;
mutex_lock(&bch_register_lock);
stopped = list_empty(&bch_cache_sets) &&
list_empty(&uncached_devices);
if (timeout < 0 || stopped)
break;
prepare_to_wait(&unregister_wait, &wait,
TASK_UNINTERRUPTIBLE);
mutex_unlock(&bch_register_lock);
schedule_timeout(timeout);
}
finish_wait(&unregister_wait, &wait);
if (stopped)
pr_info("All devices stopped\n");
else
pr_notice("Timeout waiting for devices to be closed\n");
out:
mutex_unlock(&bch_register_lock);
}
return NOTIFY_DONE;
}
static struct notifier_block reboot = {
.notifier_call = bcache_reboot,
.priority = INT_MAX, /* before any real devices */
};
static void bcache_exit(void)
{
bch_debug_exit();
bch_request_exit();
if (bcache_kobj)
kobject_put(bcache_kobj);
if (bcache_wq)
destroy_workqueue(bcache_wq);
if (bch_journal_wq)
destroy_workqueue(bch_journal_wq);
if (bch_flush_wq)
destroy_workqueue(bch_flush_wq);
bch_btree_exit();
if (bcache_major)
unregister_blkdev(bcache_major, "bcache");
unregister_reboot_notifier(&reboot);
mutex_destroy(&bch_register_lock);
}
/* Check and fixup module parameters */
static void check_module_parameters(void)
{
if (bch_cutoff_writeback_sync == 0)
bch_cutoff_writeback_sync = CUTOFF_WRITEBACK_SYNC;
else if (bch_cutoff_writeback_sync > CUTOFF_WRITEBACK_SYNC_MAX) {
pr_warn("set bch_cutoff_writeback_sync (%u) to max value %u\n",
bch_cutoff_writeback_sync, CUTOFF_WRITEBACK_SYNC_MAX);
bch_cutoff_writeback_sync = CUTOFF_WRITEBACK_SYNC_MAX;
}
if (bch_cutoff_writeback == 0)
bch_cutoff_writeback = CUTOFF_WRITEBACK;
else if (bch_cutoff_writeback > CUTOFF_WRITEBACK_MAX) {
pr_warn("set bch_cutoff_writeback (%u) to max value %u\n",
bch_cutoff_writeback, CUTOFF_WRITEBACK_MAX);
bch_cutoff_writeback = CUTOFF_WRITEBACK_MAX;
}
if (bch_cutoff_writeback > bch_cutoff_writeback_sync) {
pr_warn("set bch_cutoff_writeback (%u) to %u\n",
bch_cutoff_writeback, bch_cutoff_writeback_sync);
bch_cutoff_writeback = bch_cutoff_writeback_sync;
}
}
static int __init bcache_init(void)
{
static const struct attribute *files[] = {
&ksysfs_register.attr,
&ksysfs_register_quiet.attr,
&ksysfs_pendings_cleanup.attr,
NULL
};
check_module_parameters();
mutex_init(&bch_register_lock);
init_waitqueue_head(&unregister_wait);
register_reboot_notifier(&reboot);
bcache_major = register_blkdev(0, "bcache");
if (bcache_major < 0) {
unregister_reboot_notifier(&reboot);
mutex_destroy(&bch_register_lock);
return bcache_major;
}
if (bch_btree_init())
goto err;
bcache_wq = alloc_workqueue("bcache", WQ_MEM_RECLAIM, 0);
if (!bcache_wq)
goto err;
/*
* Let's not make this `WQ_MEM_RECLAIM` for the following reasons:
*
* 1. It used `system_wq` before which also does no memory reclaim.
* 2. With `WQ_MEM_RECLAIM` desktop stalls, increased boot times, and
* reduced throughput can be observed.
*
* We still want to user our own queue to not congest the `system_wq`.
*/
bch_flush_wq = alloc_workqueue("bch_flush", 0, 0);
if (!bch_flush_wq)
goto err;
bch_journal_wq = alloc_workqueue("bch_journal", WQ_MEM_RECLAIM, 0);
if (!bch_journal_wq)
goto err;
bcache_kobj = kobject_create_and_add("bcache", fs_kobj);
if (!bcache_kobj)
goto err;
if (bch_request_init() ||
sysfs_create_files(bcache_kobj, files))
goto err;
bch_debug_init();
closure_debug_init();
bcache_is_reboot = false;
return 0;
err:
bcache_exit();
return -ENOMEM;
}
/*
* Module hooks
*/
module_exit(bcache_exit);
module_init(bcache_init);
module_param(bch_cutoff_writeback, uint, 0);
MODULE_PARM_DESC(bch_cutoff_writeback, "threshold to cutoff writeback");
module_param(bch_cutoff_writeback_sync, uint, 0);
MODULE_PARM_DESC(bch_cutoff_writeback_sync, "hard threshold to cutoff writeback");
MODULE_DESCRIPTION("Bcache: a Linux block layer cache");
MODULE_AUTHOR("Kent Overstreet <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/bcache/super.c |
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2010 Kent Overstreet <[email protected]>
*
* Uses a block device as cache for other block devices; optimized for SSDs.
* All allocation is done in buckets, which should match the erase block size
* of the device.
*
* Buckets containing cached data are kept on a heap sorted by priority;
* bucket priority is increased on cache hit, and periodically all the buckets
* on the heap have their priority scaled down. This currently is just used as
* an LRU but in the future should allow for more intelligent heuristics.
*
* Buckets have an 8 bit counter; freeing is accomplished by incrementing the
* counter. Garbage collection is used to remove stale pointers.
*
* Indexing is done via a btree; nodes are not necessarily fully sorted, rather
* as keys are inserted we only sort the pages that have not yet been written.
* When garbage collection is run, we resort the entire node.
*
* All configuration is done via sysfs; see Documentation/admin-guide/bcache.rst.
*/
#include "bcache.h"
#include "btree.h"
#include "debug.h"
#include "extents.h"
#include "writeback.h"
static void sort_key_next(struct btree_iter *iter,
struct btree_iter_set *i)
{
i->k = bkey_next(i->k);
if (i->k == i->end)
*i = iter->data[--iter->used];
}
static bool bch_key_sort_cmp(struct btree_iter_set l,
struct btree_iter_set r)
{
int64_t c = bkey_cmp(l.k, r.k);
return c ? c > 0 : l.k < r.k;
}
static bool __ptr_invalid(struct cache_set *c, const struct bkey *k)
{
unsigned int i;
for (i = 0; i < KEY_PTRS(k); i++)
if (ptr_available(c, k, i)) {
struct cache *ca = c->cache;
size_t bucket = PTR_BUCKET_NR(c, k, i);
size_t r = bucket_remainder(c, PTR_OFFSET(k, i));
if (KEY_SIZE(k) + r > c->cache->sb.bucket_size ||
bucket < ca->sb.first_bucket ||
bucket >= ca->sb.nbuckets)
return true;
}
return false;
}
/* Common among btree and extent ptrs */
static const char *bch_ptr_status(struct cache_set *c, const struct bkey *k)
{
unsigned int i;
for (i = 0; i < KEY_PTRS(k); i++)
if (ptr_available(c, k, i)) {
struct cache *ca = c->cache;
size_t bucket = PTR_BUCKET_NR(c, k, i);
size_t r = bucket_remainder(c, PTR_OFFSET(k, i));
if (KEY_SIZE(k) + r > c->cache->sb.bucket_size)
return "bad, length too big";
if (bucket < ca->sb.first_bucket)
return "bad, short offset";
if (bucket >= ca->sb.nbuckets)
return "bad, offset past end of device";
if (ptr_stale(c, k, i))
return "stale";
}
if (!bkey_cmp(k, &ZERO_KEY))
return "bad, null key";
if (!KEY_PTRS(k))
return "bad, no pointers";
if (!KEY_SIZE(k))
return "zeroed key";
return "";
}
void bch_extent_to_text(char *buf, size_t size, const struct bkey *k)
{
unsigned int i = 0;
char *out = buf, *end = buf + size;
#define p(...) (out += scnprintf(out, end - out, __VA_ARGS__))
p("%llu:%llu len %llu -> [", KEY_INODE(k), KEY_START(k), KEY_SIZE(k));
for (i = 0; i < KEY_PTRS(k); i++) {
if (i)
p(", ");
if (PTR_DEV(k, i) == PTR_CHECK_DEV)
p("check dev");
else
p("%llu:%llu gen %llu", PTR_DEV(k, i),
PTR_OFFSET(k, i), PTR_GEN(k, i));
}
p("]");
if (KEY_DIRTY(k))
p(" dirty");
if (KEY_CSUM(k))
p(" cs%llu %llx", KEY_CSUM(k), k->ptr[1]);
#undef p
}
static void bch_bkey_dump(struct btree_keys *keys, const struct bkey *k)
{
struct btree *b = container_of(keys, struct btree, keys);
unsigned int j;
char buf[80];
bch_extent_to_text(buf, sizeof(buf), k);
pr_cont(" %s", buf);
for (j = 0; j < KEY_PTRS(k); j++) {
size_t n = PTR_BUCKET_NR(b->c, k, j);
pr_cont(" bucket %zu", n);
if (n >= b->c->cache->sb.first_bucket && n < b->c->cache->sb.nbuckets)
pr_cont(" prio %i",
PTR_BUCKET(b->c, k, j)->prio);
}
pr_cont(" %s\n", bch_ptr_status(b->c, k));
}
/* Btree ptrs */
bool __bch_btree_ptr_invalid(struct cache_set *c, const struct bkey *k)
{
char buf[80];
if (!KEY_PTRS(k) || !KEY_SIZE(k) || KEY_DIRTY(k))
goto bad;
if (__ptr_invalid(c, k))
goto bad;
return false;
bad:
bch_extent_to_text(buf, sizeof(buf), k);
cache_bug(c, "spotted btree ptr %s: %s", buf, bch_ptr_status(c, k));
return true;
}
static bool bch_btree_ptr_invalid(struct btree_keys *bk, const struct bkey *k)
{
struct btree *b = container_of(bk, struct btree, keys);
return __bch_btree_ptr_invalid(b->c, k);
}
static bool btree_ptr_bad_expensive(struct btree *b, const struct bkey *k)
{
unsigned int i;
char buf[80];
struct bucket *g;
if (mutex_trylock(&b->c->bucket_lock)) {
for (i = 0; i < KEY_PTRS(k); i++)
if (ptr_available(b->c, k, i)) {
g = PTR_BUCKET(b->c, k, i);
if (KEY_DIRTY(k) ||
g->prio != BTREE_PRIO ||
(b->c->gc_mark_valid &&
GC_MARK(g) != GC_MARK_METADATA))
goto err;
}
mutex_unlock(&b->c->bucket_lock);
}
return false;
err:
mutex_unlock(&b->c->bucket_lock);
bch_extent_to_text(buf, sizeof(buf), k);
btree_bug(b,
"inconsistent btree pointer %s: bucket %zi pin %i prio %i gen %i last_gc %i mark %llu",
buf, PTR_BUCKET_NR(b->c, k, i), atomic_read(&g->pin),
g->prio, g->gen, g->last_gc, GC_MARK(g));
return true;
}
static bool bch_btree_ptr_bad(struct btree_keys *bk, const struct bkey *k)
{
struct btree *b = container_of(bk, struct btree, keys);
unsigned int i;
if (!bkey_cmp(k, &ZERO_KEY) ||
!KEY_PTRS(k) ||
bch_ptr_invalid(bk, k))
return true;
for (i = 0; i < KEY_PTRS(k); i++)
if (!ptr_available(b->c, k, i) ||
ptr_stale(b->c, k, i))
return true;
if (expensive_debug_checks(b->c) &&
btree_ptr_bad_expensive(b, k))
return true;
return false;
}
static bool bch_btree_ptr_insert_fixup(struct btree_keys *bk,
struct bkey *insert,
struct btree_iter *iter,
struct bkey *replace_key)
{
struct btree *b = container_of(bk, struct btree, keys);
if (!KEY_OFFSET(insert))
btree_current_write(b)->prio_blocked++;
return false;
}
const struct btree_keys_ops bch_btree_keys_ops = {
.sort_cmp = bch_key_sort_cmp,
.insert_fixup = bch_btree_ptr_insert_fixup,
.key_invalid = bch_btree_ptr_invalid,
.key_bad = bch_btree_ptr_bad,
.key_to_text = bch_extent_to_text,
.key_dump = bch_bkey_dump,
};
/* Extents */
/*
* Returns true if l > r - unless l == r, in which case returns true if l is
* older than r.
*
* Necessary for btree_sort_fixup() - if there are multiple keys that compare
* equal in different sets, we have to process them newest to oldest.
*/
static bool bch_extent_sort_cmp(struct btree_iter_set l,
struct btree_iter_set r)
{
int64_t c = bkey_cmp(&START_KEY(l.k), &START_KEY(r.k));
return c ? c > 0 : l.k < r.k;
}
static struct bkey *bch_extent_sort_fixup(struct btree_iter *iter,
struct bkey *tmp)
{
while (iter->used > 1) {
struct btree_iter_set *top = iter->data, *i = top + 1;
if (iter->used > 2 &&
bch_extent_sort_cmp(i[0], i[1]))
i++;
if (bkey_cmp(top->k, &START_KEY(i->k)) <= 0)
break;
if (!KEY_SIZE(i->k)) {
sort_key_next(iter, i);
heap_sift(iter, i - top, bch_extent_sort_cmp);
continue;
}
if (top->k > i->k) {
if (bkey_cmp(top->k, i->k) >= 0)
sort_key_next(iter, i);
else
bch_cut_front(top->k, i->k);
heap_sift(iter, i - top, bch_extent_sort_cmp);
} else {
/* can't happen because of comparison func */
BUG_ON(!bkey_cmp(&START_KEY(top->k), &START_KEY(i->k)));
if (bkey_cmp(i->k, top->k) < 0) {
bkey_copy(tmp, top->k);
bch_cut_back(&START_KEY(i->k), tmp);
bch_cut_front(i->k, top->k);
heap_sift(iter, 0, bch_extent_sort_cmp);
return tmp;
} else {
bch_cut_back(&START_KEY(i->k), top->k);
}
}
}
return NULL;
}
static void bch_subtract_dirty(struct bkey *k,
struct cache_set *c,
uint64_t offset,
int sectors)
{
if (KEY_DIRTY(k))
bcache_dev_sectors_dirty_add(c, KEY_INODE(k),
offset, -sectors);
}
static bool bch_extent_insert_fixup(struct btree_keys *b,
struct bkey *insert,
struct btree_iter *iter,
struct bkey *replace_key)
{
struct cache_set *c = container_of(b, struct btree, keys)->c;
uint64_t old_offset;
unsigned int old_size, sectors_found = 0;
BUG_ON(!KEY_OFFSET(insert));
BUG_ON(!KEY_SIZE(insert));
while (1) {
struct bkey *k = bch_btree_iter_next(iter);
if (!k)
break;
if (bkey_cmp(&START_KEY(k), insert) >= 0) {
if (KEY_SIZE(k))
break;
else
continue;
}
if (bkey_cmp(k, &START_KEY(insert)) <= 0)
continue;
old_offset = KEY_START(k);
old_size = KEY_SIZE(k);
/*
* We might overlap with 0 size extents; we can't skip these
* because if they're in the set we're inserting to we have to
* adjust them so they don't overlap with the key we're
* inserting. But we don't want to check them for replace
* operations.
*/
if (replace_key && KEY_SIZE(k)) {
/*
* k might have been split since we inserted/found the
* key we're replacing
*/
unsigned int i;
uint64_t offset = KEY_START(k) -
KEY_START(replace_key);
/* But it must be a subset of the replace key */
if (KEY_START(k) < KEY_START(replace_key) ||
KEY_OFFSET(k) > KEY_OFFSET(replace_key))
goto check_failed;
/* We didn't find a key that we were supposed to */
if (KEY_START(k) > KEY_START(insert) + sectors_found)
goto check_failed;
if (!bch_bkey_equal_header(k, replace_key))
goto check_failed;
/* skip past gen */
offset <<= 8;
BUG_ON(!KEY_PTRS(replace_key));
for (i = 0; i < KEY_PTRS(replace_key); i++)
if (k->ptr[i] != replace_key->ptr[i] + offset)
goto check_failed;
sectors_found = KEY_OFFSET(k) - KEY_START(insert);
}
if (bkey_cmp(insert, k) < 0 &&
bkey_cmp(&START_KEY(insert), &START_KEY(k)) > 0) {
/*
* We overlapped in the middle of an existing key: that
* means we have to split the old key. But we have to do
* slightly different things depending on whether the
* old key has been written out yet.
*/
struct bkey *top;
bch_subtract_dirty(k, c, KEY_START(insert),
KEY_SIZE(insert));
if (bkey_written(b, k)) {
/*
* We insert a new key to cover the top of the
* old key, and the old key is modified in place
* to represent the bottom split.
*
* It's completely arbitrary whether the new key
* is the top or the bottom, but it has to match
* up with what btree_sort_fixup() does - it
* doesn't check for this kind of overlap, it
* depends on us inserting a new key for the top
* here.
*/
top = bch_bset_search(b, bset_tree_last(b),
insert);
bch_bset_insert(b, top, k);
} else {
BKEY_PADDED(key) temp;
bkey_copy(&temp.key, k);
bch_bset_insert(b, k, &temp.key);
top = bkey_next(k);
}
bch_cut_front(insert, top);
bch_cut_back(&START_KEY(insert), k);
bch_bset_fix_invalidated_key(b, k);
goto out;
}
if (bkey_cmp(insert, k) < 0) {
bch_cut_front(insert, k);
} else {
if (bkey_cmp(&START_KEY(insert), &START_KEY(k)) > 0)
old_offset = KEY_START(insert);
if (bkey_written(b, k) &&
bkey_cmp(&START_KEY(insert), &START_KEY(k)) <= 0) {
/*
* Completely overwrote, so we don't have to
* invalidate the binary search tree
*/
bch_cut_front(k, k);
} else {
__bch_cut_back(&START_KEY(insert), k);
bch_bset_fix_invalidated_key(b, k);
}
}
bch_subtract_dirty(k, c, old_offset, old_size - KEY_SIZE(k));
}
check_failed:
if (replace_key) {
if (!sectors_found) {
return true;
} else if (sectors_found < KEY_SIZE(insert)) {
SET_KEY_OFFSET(insert, KEY_OFFSET(insert) -
(KEY_SIZE(insert) - sectors_found));
SET_KEY_SIZE(insert, sectors_found);
}
}
out:
if (KEY_DIRTY(insert))
bcache_dev_sectors_dirty_add(c, KEY_INODE(insert),
KEY_START(insert),
KEY_SIZE(insert));
return false;
}
bool __bch_extent_invalid(struct cache_set *c, const struct bkey *k)
{
char buf[80];
if (!KEY_SIZE(k))
return true;
if (KEY_SIZE(k) > KEY_OFFSET(k))
goto bad;
if (__ptr_invalid(c, k))
goto bad;
return false;
bad:
bch_extent_to_text(buf, sizeof(buf), k);
cache_bug(c, "spotted extent %s: %s", buf, bch_ptr_status(c, k));
return true;
}
static bool bch_extent_invalid(struct btree_keys *bk, const struct bkey *k)
{
struct btree *b = container_of(bk, struct btree, keys);
return __bch_extent_invalid(b->c, k);
}
static bool bch_extent_bad_expensive(struct btree *b, const struct bkey *k,
unsigned int ptr)
{
struct bucket *g = PTR_BUCKET(b->c, k, ptr);
char buf[80];
if (mutex_trylock(&b->c->bucket_lock)) {
if (b->c->gc_mark_valid &&
(!GC_MARK(g) ||
GC_MARK(g) == GC_MARK_METADATA ||
(GC_MARK(g) != GC_MARK_DIRTY && KEY_DIRTY(k))))
goto err;
if (g->prio == BTREE_PRIO)
goto err;
mutex_unlock(&b->c->bucket_lock);
}
return false;
err:
mutex_unlock(&b->c->bucket_lock);
bch_extent_to_text(buf, sizeof(buf), k);
btree_bug(b,
"inconsistent extent pointer %s:\nbucket %zu pin %i prio %i gen %i last_gc %i mark %llu",
buf, PTR_BUCKET_NR(b->c, k, ptr), atomic_read(&g->pin),
g->prio, g->gen, g->last_gc, GC_MARK(g));
return true;
}
static bool bch_extent_bad(struct btree_keys *bk, const struct bkey *k)
{
struct btree *b = container_of(bk, struct btree, keys);
unsigned int i, stale;
char buf[80];
if (!KEY_PTRS(k) ||
bch_extent_invalid(bk, k))
return true;
for (i = 0; i < KEY_PTRS(k); i++)
if (!ptr_available(b->c, k, i))
return true;
for (i = 0; i < KEY_PTRS(k); i++) {
stale = ptr_stale(b->c, k, i);
if (stale && KEY_DIRTY(k)) {
bch_extent_to_text(buf, sizeof(buf), k);
pr_info("stale dirty pointer, stale %u, key: %s\n",
stale, buf);
}
btree_bug_on(stale > BUCKET_GC_GEN_MAX, b,
"key too stale: %i, need_gc %u",
stale, b->c->need_gc);
if (stale)
return true;
if (expensive_debug_checks(b->c) &&
bch_extent_bad_expensive(b, k, i))
return true;
}
return false;
}
static uint64_t merge_chksums(struct bkey *l, struct bkey *r)
{
return (l->ptr[KEY_PTRS(l)] + r->ptr[KEY_PTRS(r)]) &
~((uint64_t)1 << 63);
}
static bool bch_extent_merge(struct btree_keys *bk,
struct bkey *l,
struct bkey *r)
{
struct btree *b = container_of(bk, struct btree, keys);
unsigned int i;
if (key_merging_disabled(b->c))
return false;
for (i = 0; i < KEY_PTRS(l); i++)
if (l->ptr[i] + MAKE_PTR(0, KEY_SIZE(l), 0) != r->ptr[i] ||
PTR_BUCKET_NR(b->c, l, i) != PTR_BUCKET_NR(b->c, r, i))
return false;
/* Keys with no pointers aren't restricted to one bucket and could
* overflow KEY_SIZE
*/
if (KEY_SIZE(l) + KEY_SIZE(r) > USHRT_MAX) {
SET_KEY_OFFSET(l, KEY_OFFSET(l) + USHRT_MAX - KEY_SIZE(l));
SET_KEY_SIZE(l, USHRT_MAX);
bch_cut_front(l, r);
return false;
}
if (KEY_CSUM(l)) {
if (KEY_CSUM(r))
l->ptr[KEY_PTRS(l)] = merge_chksums(l, r);
else
SET_KEY_CSUM(l, 0);
}
SET_KEY_OFFSET(l, KEY_OFFSET(l) + KEY_SIZE(r));
SET_KEY_SIZE(l, KEY_SIZE(l) + KEY_SIZE(r));
return true;
}
const struct btree_keys_ops bch_extent_keys_ops = {
.sort_cmp = bch_extent_sort_cmp,
.sort_fixup = bch_extent_sort_fixup,
.insert_fixup = bch_extent_insert_fixup,
.key_invalid = bch_extent_invalid,
.key_bad = bch_extent_bad,
.key_merge = bch_extent_merge,
.key_to_text = bch_extent_to_text,
.key_dump = bch_bkey_dump,
.is_extents = true,
};
| linux-master | drivers/md/bcache/extents.c |
// SPDX-License-Identifier: GPL-2.0
/*
* background writeback - scan btree for dirty data and write it to the backing
* device
*
* Copyright 2010, 2011 Kent Overstreet <[email protected]>
* Copyright 2012 Google, Inc.
*/
#include "bcache.h"
#include "btree.h"
#include "debug.h"
#include "writeback.h"
#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/sched/clock.h>
#include <trace/events/bcache.h>
static void update_gc_after_writeback(struct cache_set *c)
{
if (c->gc_after_writeback != (BCH_ENABLE_AUTO_GC) ||
c->gc_stats.in_use < BCH_AUTO_GC_DIRTY_THRESHOLD)
return;
c->gc_after_writeback |= BCH_DO_AUTO_GC;
}
/* Rate limiting */
static uint64_t __calc_target_rate(struct cached_dev *dc)
{
struct cache_set *c = dc->disk.c;
/*
* This is the size of the cache, minus the amount used for
* flash-only devices
*/
uint64_t cache_sectors = c->nbuckets * c->cache->sb.bucket_size -
atomic_long_read(&c->flash_dev_dirty_sectors);
/*
* Unfortunately there is no control of global dirty data. If the
* user states that they want 10% dirty data in the cache, and has,
* e.g., 5 backing volumes of equal size, we try and ensure each
* backing volume uses about 2% of the cache for dirty data.
*/
uint32_t bdev_share =
div64_u64(bdev_nr_sectors(dc->bdev) << WRITEBACK_SHARE_SHIFT,
c->cached_dev_sectors);
uint64_t cache_dirty_target =
div_u64(cache_sectors * dc->writeback_percent, 100);
/* Ensure each backing dev gets at least one dirty share */
if (bdev_share < 1)
bdev_share = 1;
return (cache_dirty_target * bdev_share) >> WRITEBACK_SHARE_SHIFT;
}
static void __update_writeback_rate(struct cached_dev *dc)
{
/*
* PI controller:
* Figures out the amount that should be written per second.
*
* First, the error (number of sectors that are dirty beyond our
* target) is calculated. The error is accumulated (numerically
* integrated).
*
* Then, the proportional value and integral value are scaled
* based on configured values. These are stored as inverses to
* avoid fixed point math and to make configuration easy-- e.g.
* the default value of 40 for writeback_rate_p_term_inverse
* attempts to write at a rate that would retire all the dirty
* blocks in 40 seconds.
*
* The writeback_rate_i_inverse value of 10000 means that 1/10000th
* of the error is accumulated in the integral term per second.
* This acts as a slow, long-term average that is not subject to
* variations in usage like the p term.
*/
int64_t target = __calc_target_rate(dc);
int64_t dirty = bcache_dev_sectors_dirty(&dc->disk);
int64_t error = dirty - target;
int64_t proportional_scaled =
div_s64(error, dc->writeback_rate_p_term_inverse);
int64_t integral_scaled;
uint32_t new_rate;
/*
* We need to consider the number of dirty buckets as well
* when calculating the proportional_scaled, Otherwise we might
* have an unreasonable small writeback rate at a highly fragmented situation
* when very few dirty sectors consumed a lot dirty buckets, the
* worst case is when dirty buckets reached cutoff_writeback_sync and
* dirty data is still not even reached to writeback percent, so the rate
* still will be at the minimum value, which will cause the write
* stuck at a non-writeback mode.
*/
struct cache_set *c = dc->disk.c;
int64_t dirty_buckets = c->nbuckets - c->avail_nbuckets;
if (dc->writeback_consider_fragment &&
c->gc_stats.in_use > BCH_WRITEBACK_FRAGMENT_THRESHOLD_LOW && dirty > 0) {
int64_t fragment =
div_s64((dirty_buckets * c->cache->sb.bucket_size), dirty);
int64_t fp_term;
int64_t fps;
if (c->gc_stats.in_use <= BCH_WRITEBACK_FRAGMENT_THRESHOLD_MID) {
fp_term = (int64_t)dc->writeback_rate_fp_term_low *
(c->gc_stats.in_use - BCH_WRITEBACK_FRAGMENT_THRESHOLD_LOW);
} else if (c->gc_stats.in_use <= BCH_WRITEBACK_FRAGMENT_THRESHOLD_HIGH) {
fp_term = (int64_t)dc->writeback_rate_fp_term_mid *
(c->gc_stats.in_use - BCH_WRITEBACK_FRAGMENT_THRESHOLD_MID);
} else {
fp_term = (int64_t)dc->writeback_rate_fp_term_high *
(c->gc_stats.in_use - BCH_WRITEBACK_FRAGMENT_THRESHOLD_HIGH);
}
fps = div_s64(dirty, dirty_buckets) * fp_term;
if (fragment > 3 && fps > proportional_scaled) {
/* Only overrite the p when fragment > 3 */
proportional_scaled = fps;
}
}
if ((error < 0 && dc->writeback_rate_integral > 0) ||
(error > 0 && time_before64(local_clock(),
dc->writeback_rate.next + NSEC_PER_MSEC))) {
/*
* Only decrease the integral term if it's more than
* zero. Only increase the integral term if the device
* is keeping up. (Don't wind up the integral
* ineffectively in either case).
*
* It's necessary to scale this by
* writeback_rate_update_seconds to keep the integral
* term dimensioned properly.
*/
dc->writeback_rate_integral += error *
dc->writeback_rate_update_seconds;
}
integral_scaled = div_s64(dc->writeback_rate_integral,
dc->writeback_rate_i_term_inverse);
new_rate = clamp_t(int32_t, (proportional_scaled + integral_scaled),
dc->writeback_rate_minimum, NSEC_PER_SEC);
dc->writeback_rate_proportional = proportional_scaled;
dc->writeback_rate_integral_scaled = integral_scaled;
dc->writeback_rate_change = new_rate -
atomic_long_read(&dc->writeback_rate.rate);
atomic_long_set(&dc->writeback_rate.rate, new_rate);
dc->writeback_rate_target = target;
}
static bool idle_counter_exceeded(struct cache_set *c)
{
int counter, dev_nr;
/*
* If c->idle_counter is overflow (idel for really long time),
* reset as 0 and not set maximum rate this time for code
* simplicity.
*/
counter = atomic_inc_return(&c->idle_counter);
if (counter <= 0) {
atomic_set(&c->idle_counter, 0);
return false;
}
dev_nr = atomic_read(&c->attached_dev_nr);
if (dev_nr == 0)
return false;
/*
* c->idle_counter is increased by writeback thread of all
* attached backing devices, in order to represent a rough
* time period, counter should be divided by dev_nr.
* Otherwise the idle time cannot be larger with more backing
* device attached.
* The following calculation equals to checking
* (counter / dev_nr) < (dev_nr * 6)
*/
if (counter < (dev_nr * dev_nr * 6))
return false;
return true;
}
/*
* Idle_counter is increased every time when update_writeback_rate() is
* called. If all backing devices attached to the same cache set have
* identical dc->writeback_rate_update_seconds values, it is about 6
* rounds of update_writeback_rate() on each backing device before
* c->at_max_writeback_rate is set to 1, and then max wrteback rate set
* to each dc->writeback_rate.rate.
* In order to avoid extra locking cost for counting exact dirty cached
* devices number, c->attached_dev_nr is used to calculate the idle
* throushold. It might be bigger if not all cached device are in write-
* back mode, but it still works well with limited extra rounds of
* update_writeback_rate().
*/
static bool set_at_max_writeback_rate(struct cache_set *c,
struct cached_dev *dc)
{
/* Don't sst max writeback rate if it is disabled */
if (!c->idle_max_writeback_rate_enabled)
return false;
/* Don't set max writeback rate if gc is running */
if (!c->gc_mark_valid)
return false;
if (!idle_counter_exceeded(c))
return false;
if (atomic_read(&c->at_max_writeback_rate) != 1)
atomic_set(&c->at_max_writeback_rate, 1);
atomic_long_set(&dc->writeback_rate.rate, INT_MAX);
/* keep writeback_rate_target as existing value */
dc->writeback_rate_proportional = 0;
dc->writeback_rate_integral_scaled = 0;
dc->writeback_rate_change = 0;
/*
* In case new I/O arrives during before
* set_at_max_writeback_rate() returns.
*/
if (!idle_counter_exceeded(c) ||
!atomic_read(&c->at_max_writeback_rate))
return false;
return true;
}
static void update_writeback_rate(struct work_struct *work)
{
struct cached_dev *dc = container_of(to_delayed_work(work),
struct cached_dev,
writeback_rate_update);
struct cache_set *c = dc->disk.c;
/*
* should check BCACHE_DEV_RATE_DW_RUNNING before calling
* cancel_delayed_work_sync().
*/
set_bit(BCACHE_DEV_RATE_DW_RUNNING, &dc->disk.flags);
/* paired with where BCACHE_DEV_RATE_DW_RUNNING is tested */
smp_mb__after_atomic();
/*
* CACHE_SET_IO_DISABLE might be set via sysfs interface,
* check it here too.
*/
if (!test_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags) ||
test_bit(CACHE_SET_IO_DISABLE, &c->flags)) {
clear_bit(BCACHE_DEV_RATE_DW_RUNNING, &dc->disk.flags);
/* paired with where BCACHE_DEV_RATE_DW_RUNNING is tested */
smp_mb__after_atomic();
return;
}
/*
* If the whole cache set is idle, set_at_max_writeback_rate()
* will set writeback rate to a max number. Then it is
* unncessary to update writeback rate for an idle cache set
* in maximum writeback rate number(s).
*/
if (atomic_read(&dc->has_dirty) && dc->writeback_percent &&
!set_at_max_writeback_rate(c, dc)) {
do {
if (!down_read_trylock((&dc->writeback_lock))) {
dc->rate_update_retry++;
if (dc->rate_update_retry <=
BCH_WBRATE_UPDATE_MAX_SKIPS)
break;
down_read(&dc->writeback_lock);
dc->rate_update_retry = 0;
}
__update_writeback_rate(dc);
update_gc_after_writeback(c);
up_read(&dc->writeback_lock);
} while (0);
}
/*
* CACHE_SET_IO_DISABLE might be set via sysfs interface,
* check it here too.
*/
if (test_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags) &&
!test_bit(CACHE_SET_IO_DISABLE, &c->flags)) {
schedule_delayed_work(&dc->writeback_rate_update,
dc->writeback_rate_update_seconds * HZ);
}
/*
* should check BCACHE_DEV_RATE_DW_RUNNING before calling
* cancel_delayed_work_sync().
*/
clear_bit(BCACHE_DEV_RATE_DW_RUNNING, &dc->disk.flags);
/* paired with where BCACHE_DEV_RATE_DW_RUNNING is tested */
smp_mb__after_atomic();
}
static unsigned int writeback_delay(struct cached_dev *dc,
unsigned int sectors)
{
if (test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) ||
!dc->writeback_percent)
return 0;
return bch_next_delay(&dc->writeback_rate, sectors);
}
struct dirty_io {
struct closure cl;
struct cached_dev *dc;
uint16_t sequence;
struct bio bio;
};
static void dirty_init(struct keybuf_key *w)
{
struct dirty_io *io = w->private;
struct bio *bio = &io->bio;
bio_init(bio, NULL, bio->bi_inline_vecs,
DIV_ROUND_UP(KEY_SIZE(&w->key), PAGE_SECTORS), 0);
if (!io->dc->writeback_percent)
bio_set_prio(bio, IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0));
bio->bi_iter.bi_size = KEY_SIZE(&w->key) << 9;
bio->bi_private = w;
bch_bio_map(bio, NULL);
}
static void dirty_io_destructor(struct closure *cl)
{
struct dirty_io *io = container_of(cl, struct dirty_io, cl);
kfree(io);
}
static void write_dirty_finish(struct closure *cl)
{
struct dirty_io *io = container_of(cl, struct dirty_io, cl);
struct keybuf_key *w = io->bio.bi_private;
struct cached_dev *dc = io->dc;
bio_free_pages(&io->bio);
/* This is kind of a dumb way of signalling errors. */
if (KEY_DIRTY(&w->key)) {
int ret;
unsigned int i;
struct keylist keys;
bch_keylist_init(&keys);
bkey_copy(keys.top, &w->key);
SET_KEY_DIRTY(keys.top, false);
bch_keylist_push(&keys);
for (i = 0; i < KEY_PTRS(&w->key); i++)
atomic_inc(&PTR_BUCKET(dc->disk.c, &w->key, i)->pin);
ret = bch_btree_insert(dc->disk.c, &keys, NULL, &w->key);
if (ret)
trace_bcache_writeback_collision(&w->key);
atomic_long_inc(ret
? &dc->disk.c->writeback_keys_failed
: &dc->disk.c->writeback_keys_done);
}
bch_keybuf_del(&dc->writeback_keys, w);
up(&dc->in_flight);
closure_return_with_destructor(cl, dirty_io_destructor);
}
static void dirty_endio(struct bio *bio)
{
struct keybuf_key *w = bio->bi_private;
struct dirty_io *io = w->private;
if (bio->bi_status) {
SET_KEY_DIRTY(&w->key, false);
bch_count_backing_io_errors(io->dc, bio);
}
closure_put(&io->cl);
}
static void write_dirty(struct closure *cl)
{
struct dirty_io *io = container_of(cl, struct dirty_io, cl);
struct keybuf_key *w = io->bio.bi_private;
struct cached_dev *dc = io->dc;
uint16_t next_sequence;
if (atomic_read(&dc->writeback_sequence_next) != io->sequence) {
/* Not our turn to write; wait for a write to complete */
closure_wait(&dc->writeback_ordering_wait, cl);
if (atomic_read(&dc->writeback_sequence_next) == io->sequence) {
/*
* Edge case-- it happened in indeterminate order
* relative to when we were added to wait list..
*/
closure_wake_up(&dc->writeback_ordering_wait);
}
continue_at(cl, write_dirty, io->dc->writeback_write_wq);
return;
}
next_sequence = io->sequence + 1;
/*
* IO errors are signalled using the dirty bit on the key.
* If we failed to read, we should not attempt to write to the
* backing device. Instead, immediately go to write_dirty_finish
* to clean up.
*/
if (KEY_DIRTY(&w->key)) {
dirty_init(w);
io->bio.bi_opf = REQ_OP_WRITE;
io->bio.bi_iter.bi_sector = KEY_START(&w->key);
bio_set_dev(&io->bio, io->dc->bdev);
io->bio.bi_end_io = dirty_endio;
/* I/O request sent to backing device */
closure_bio_submit(io->dc->disk.c, &io->bio, cl);
}
atomic_set(&dc->writeback_sequence_next, next_sequence);
closure_wake_up(&dc->writeback_ordering_wait);
continue_at(cl, write_dirty_finish, io->dc->writeback_write_wq);
}
static void read_dirty_endio(struct bio *bio)
{
struct keybuf_key *w = bio->bi_private;
struct dirty_io *io = w->private;
/* is_read = 1 */
bch_count_io_errors(io->dc->disk.c->cache,
bio->bi_status, 1,
"reading dirty data from cache");
dirty_endio(bio);
}
static void read_dirty_submit(struct closure *cl)
{
struct dirty_io *io = container_of(cl, struct dirty_io, cl);
closure_bio_submit(io->dc->disk.c, &io->bio, cl);
continue_at(cl, write_dirty, io->dc->writeback_write_wq);
}
static void read_dirty(struct cached_dev *dc)
{
unsigned int delay = 0;
struct keybuf_key *next, *keys[MAX_WRITEBACKS_IN_PASS], *w;
size_t size;
int nk, i;
struct dirty_io *io;
struct closure cl;
uint16_t sequence = 0;
BUG_ON(!llist_empty(&dc->writeback_ordering_wait.list));
atomic_set(&dc->writeback_sequence_next, sequence);
closure_init_stack(&cl);
/*
* XXX: if we error, background writeback just spins. Should use some
* mempools.
*/
next = bch_keybuf_next(&dc->writeback_keys);
while (!kthread_should_stop() &&
!test_bit(CACHE_SET_IO_DISABLE, &dc->disk.c->flags) &&
next) {
size = 0;
nk = 0;
do {
BUG_ON(ptr_stale(dc->disk.c, &next->key, 0));
/*
* Don't combine too many operations, even if they
* are all small.
*/
if (nk >= MAX_WRITEBACKS_IN_PASS)
break;
/*
* If the current operation is very large, don't
* further combine operations.
*/
if (size >= MAX_WRITESIZE_IN_PASS)
break;
/*
* Operations are only eligible to be combined
* if they are contiguous.
*
* TODO: add a heuristic willing to fire a
* certain amount of non-contiguous IO per pass,
* so that we can benefit from backing device
* command queueing.
*/
if ((nk != 0) && bkey_cmp(&keys[nk-1]->key,
&START_KEY(&next->key)))
break;
size += KEY_SIZE(&next->key);
keys[nk++] = next;
} while ((next = bch_keybuf_next(&dc->writeback_keys)));
/* Now we have gathered a set of 1..5 keys to write back. */
for (i = 0; i < nk; i++) {
w = keys[i];
io = kzalloc(struct_size(io, bio.bi_inline_vecs,
DIV_ROUND_UP(KEY_SIZE(&w->key), PAGE_SECTORS)),
GFP_KERNEL);
if (!io)
goto err;
w->private = io;
io->dc = dc;
io->sequence = sequence++;
dirty_init(w);
io->bio.bi_opf = REQ_OP_READ;
io->bio.bi_iter.bi_sector = PTR_OFFSET(&w->key, 0);
bio_set_dev(&io->bio, dc->disk.c->cache->bdev);
io->bio.bi_end_io = read_dirty_endio;
if (bch_bio_alloc_pages(&io->bio, GFP_KERNEL))
goto err_free;
trace_bcache_writeback(&w->key);
down(&dc->in_flight);
/*
* We've acquired a semaphore for the maximum
* simultaneous number of writebacks; from here
* everything happens asynchronously.
*/
closure_call(&io->cl, read_dirty_submit, NULL, &cl);
}
delay = writeback_delay(dc, size);
while (!kthread_should_stop() &&
!test_bit(CACHE_SET_IO_DISABLE, &dc->disk.c->flags) &&
delay) {
schedule_timeout_interruptible(delay);
delay = writeback_delay(dc, 0);
}
}
if (0) {
err_free:
kfree(w->private);
err:
bch_keybuf_del(&dc->writeback_keys, w);
}
/*
* Wait for outstanding writeback IOs to finish (and keybuf slots to be
* freed) before refilling again
*/
closure_sync(&cl);
}
/* Scan for dirty data */
void bcache_dev_sectors_dirty_add(struct cache_set *c, unsigned int inode,
uint64_t offset, int nr_sectors)
{
struct bcache_device *d = c->devices[inode];
unsigned int stripe_offset, sectors_dirty;
int stripe;
if (!d)
return;
stripe = offset_to_stripe(d, offset);
if (stripe < 0)
return;
if (UUID_FLASH_ONLY(&c->uuids[inode]))
atomic_long_add(nr_sectors, &c->flash_dev_dirty_sectors);
stripe_offset = offset & (d->stripe_size - 1);
while (nr_sectors) {
int s = min_t(unsigned int, abs(nr_sectors),
d->stripe_size - stripe_offset);
if (nr_sectors < 0)
s = -s;
if (stripe >= d->nr_stripes)
return;
sectors_dirty = atomic_add_return(s,
d->stripe_sectors_dirty + stripe);
if (sectors_dirty == d->stripe_size) {
if (!test_bit(stripe, d->full_dirty_stripes))
set_bit(stripe, d->full_dirty_stripes);
} else {
if (test_bit(stripe, d->full_dirty_stripes))
clear_bit(stripe, d->full_dirty_stripes);
}
nr_sectors -= s;
stripe_offset = 0;
stripe++;
}
}
static bool dirty_pred(struct keybuf *buf, struct bkey *k)
{
struct cached_dev *dc = container_of(buf,
struct cached_dev,
writeback_keys);
BUG_ON(KEY_INODE(k) != dc->disk.id);
return KEY_DIRTY(k);
}
static void refill_full_stripes(struct cached_dev *dc)
{
struct keybuf *buf = &dc->writeback_keys;
unsigned int start_stripe, next_stripe;
int stripe;
bool wrapped = false;
stripe = offset_to_stripe(&dc->disk, KEY_OFFSET(&buf->last_scanned));
if (stripe < 0)
stripe = 0;
start_stripe = stripe;
while (1) {
stripe = find_next_bit(dc->disk.full_dirty_stripes,
dc->disk.nr_stripes, stripe);
if (stripe == dc->disk.nr_stripes)
goto next;
next_stripe = find_next_zero_bit(dc->disk.full_dirty_stripes,
dc->disk.nr_stripes, stripe);
buf->last_scanned = KEY(dc->disk.id,
stripe * dc->disk.stripe_size, 0);
bch_refill_keybuf(dc->disk.c, buf,
&KEY(dc->disk.id,
next_stripe * dc->disk.stripe_size, 0),
dirty_pred);
if (array_freelist_empty(&buf->freelist))
return;
stripe = next_stripe;
next:
if (wrapped && stripe > start_stripe)
return;
if (stripe == dc->disk.nr_stripes) {
stripe = 0;
wrapped = true;
}
}
}
/*
* Returns true if we scanned the entire disk
*/
static bool refill_dirty(struct cached_dev *dc)
{
struct keybuf *buf = &dc->writeback_keys;
struct bkey start = KEY(dc->disk.id, 0, 0);
struct bkey end = KEY(dc->disk.id, MAX_KEY_OFFSET, 0);
struct bkey start_pos;
/*
* make sure keybuf pos is inside the range for this disk - at bringup
* we might not be attached yet so this disk's inode nr isn't
* initialized then
*/
if (bkey_cmp(&buf->last_scanned, &start) < 0 ||
bkey_cmp(&buf->last_scanned, &end) > 0)
buf->last_scanned = start;
if (dc->partial_stripes_expensive) {
refill_full_stripes(dc);
if (array_freelist_empty(&buf->freelist))
return false;
}
start_pos = buf->last_scanned;
bch_refill_keybuf(dc->disk.c, buf, &end, dirty_pred);
if (bkey_cmp(&buf->last_scanned, &end) < 0)
return false;
/*
* If we get to the end start scanning again from the beginning, and
* only scan up to where we initially started scanning from:
*/
buf->last_scanned = start;
bch_refill_keybuf(dc->disk.c, buf, &start_pos, dirty_pred);
return bkey_cmp(&buf->last_scanned, &start_pos) >= 0;
}
static int bch_writeback_thread(void *arg)
{
struct cached_dev *dc = arg;
struct cache_set *c = dc->disk.c;
bool searched_full_index;
bch_ratelimit_reset(&dc->writeback_rate);
while (!kthread_should_stop() &&
!test_bit(CACHE_SET_IO_DISABLE, &c->flags)) {
down_write(&dc->writeback_lock);
set_current_state(TASK_INTERRUPTIBLE);
/*
* If the bache device is detaching, skip here and continue
* to perform writeback. Otherwise, if no dirty data on cache,
* or there is dirty data on cache but writeback is disabled,
* the writeback thread should sleep here and wait for others
* to wake up it.
*/
if (!test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) &&
(!atomic_read(&dc->has_dirty) || !dc->writeback_running)) {
up_write(&dc->writeback_lock);
if (kthread_should_stop() ||
test_bit(CACHE_SET_IO_DISABLE, &c->flags)) {
set_current_state(TASK_RUNNING);
break;
}
schedule();
continue;
}
set_current_state(TASK_RUNNING);
searched_full_index = refill_dirty(dc);
if (searched_full_index &&
RB_EMPTY_ROOT(&dc->writeback_keys.keys)) {
atomic_set(&dc->has_dirty, 0);
SET_BDEV_STATE(&dc->sb, BDEV_STATE_CLEAN);
bch_write_bdev_super(dc, NULL);
/*
* If bcache device is detaching via sysfs interface,
* writeback thread should stop after there is no dirty
* data on cache. BCACHE_DEV_DETACHING flag is set in
* bch_cached_dev_detach().
*/
if (test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags)) {
struct closure cl;
closure_init_stack(&cl);
memset(&dc->sb.set_uuid, 0, 16);
SET_BDEV_STATE(&dc->sb, BDEV_STATE_NONE);
bch_write_bdev_super(dc, &cl);
closure_sync(&cl);
up_write(&dc->writeback_lock);
break;
}
/*
* When dirty data rate is high (e.g. 50%+), there might
* be heavy buckets fragmentation after writeback
* finished, which hurts following write performance.
* If users really care about write performance they
* may set BCH_ENABLE_AUTO_GC via sysfs, then when
* BCH_DO_AUTO_GC is set, garbage collection thread
* will be wake up here. After moving gc, the shrunk
* btree and discarded free buckets SSD space may be
* helpful for following write requests.
*/
if (c->gc_after_writeback ==
(BCH_ENABLE_AUTO_GC|BCH_DO_AUTO_GC)) {
c->gc_after_writeback &= ~BCH_DO_AUTO_GC;
force_wake_up_gc(c);
}
}
up_write(&dc->writeback_lock);
read_dirty(dc);
if (searched_full_index) {
unsigned int delay = dc->writeback_delay * HZ;
while (delay &&
!kthread_should_stop() &&
!test_bit(CACHE_SET_IO_DISABLE, &c->flags) &&
!test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags))
delay = schedule_timeout_interruptible(delay);
bch_ratelimit_reset(&dc->writeback_rate);
}
}
if (dc->writeback_write_wq)
destroy_workqueue(dc->writeback_write_wq);
cached_dev_put(dc);
wait_for_kthread_stop();
return 0;
}
/* Init */
#define INIT_KEYS_EACH_TIME 500000
struct sectors_dirty_init {
struct btree_op op;
unsigned int inode;
size_t count;
};
static int sectors_dirty_init_fn(struct btree_op *_op, struct btree *b,
struct bkey *k)
{
struct sectors_dirty_init *op = container_of(_op,
struct sectors_dirty_init, op);
if (KEY_INODE(k) > op->inode)
return MAP_DONE;
if (KEY_DIRTY(k))
bcache_dev_sectors_dirty_add(b->c, KEY_INODE(k),
KEY_START(k), KEY_SIZE(k));
op->count++;
if (!(op->count % INIT_KEYS_EACH_TIME))
cond_resched();
return MAP_CONTINUE;
}
static int bch_root_node_dirty_init(struct cache_set *c,
struct bcache_device *d,
struct bkey *k)
{
struct sectors_dirty_init op;
int ret;
bch_btree_op_init(&op.op, -1);
op.inode = d->id;
op.count = 0;
ret = bcache_btree(map_keys_recurse,
k,
c->root,
&op.op,
&KEY(op.inode, 0, 0),
sectors_dirty_init_fn,
0);
if (ret < 0)
pr_warn("sectors dirty init failed, ret=%d!\n", ret);
/*
* The op may be added to cache_set's btree_cache_wait
* in mca_cannibalize(), must ensure it is removed from
* the list and release btree_cache_alloc_lock before
* free op memory.
* Otherwise, the btree_cache_wait will be damaged.
*/
bch_cannibalize_unlock(c);
finish_wait(&c->btree_cache_wait, &(&op.op)->wait);
return ret;
}
static int bch_dirty_init_thread(void *arg)
{
struct dirty_init_thrd_info *info = arg;
struct bch_dirty_init_state *state = info->state;
struct cache_set *c = state->c;
struct btree_iter iter;
struct bkey *k, *p;
int cur_idx, prev_idx, skip_nr;
k = p = NULL;
cur_idx = prev_idx = 0;
bch_btree_iter_init(&c->root->keys, &iter, NULL);
k = bch_btree_iter_next_filter(&iter, &c->root->keys, bch_ptr_bad);
BUG_ON(!k);
p = k;
while (k) {
spin_lock(&state->idx_lock);
cur_idx = state->key_idx;
state->key_idx++;
spin_unlock(&state->idx_lock);
skip_nr = cur_idx - prev_idx;
while (skip_nr) {
k = bch_btree_iter_next_filter(&iter,
&c->root->keys,
bch_ptr_bad);
if (k)
p = k;
else {
atomic_set(&state->enough, 1);
/* Update state->enough earlier */
smp_mb__after_atomic();
goto out;
}
skip_nr--;
}
if (p) {
if (bch_root_node_dirty_init(c, state->d, p) < 0)
goto out;
}
p = NULL;
prev_idx = cur_idx;
}
out:
/* In order to wake up state->wait in time */
smp_mb__before_atomic();
if (atomic_dec_and_test(&state->started))
wake_up(&state->wait);
return 0;
}
static int bch_btre_dirty_init_thread_nr(void)
{
int n = num_online_cpus()/2;
if (n == 0)
n = 1;
else if (n > BCH_DIRTY_INIT_THRD_MAX)
n = BCH_DIRTY_INIT_THRD_MAX;
return n;
}
void bch_sectors_dirty_init(struct bcache_device *d)
{
int i;
struct bkey *k = NULL;
struct btree_iter iter;
struct sectors_dirty_init op;
struct cache_set *c = d->c;
struct bch_dirty_init_state state;
/* Just count root keys if no leaf node */
rw_lock(0, c->root, c->root->level);
if (c->root->level == 0) {
bch_btree_op_init(&op.op, -1);
op.inode = d->id;
op.count = 0;
for_each_key_filter(&c->root->keys,
k, &iter, bch_ptr_invalid)
sectors_dirty_init_fn(&op.op, c->root, k);
rw_unlock(0, c->root);
return;
}
memset(&state, 0, sizeof(struct bch_dirty_init_state));
state.c = c;
state.d = d;
state.total_threads = bch_btre_dirty_init_thread_nr();
state.key_idx = 0;
spin_lock_init(&state.idx_lock);
atomic_set(&state.started, 0);
atomic_set(&state.enough, 0);
init_waitqueue_head(&state.wait);
for (i = 0; i < state.total_threads; i++) {
/* Fetch latest state.enough earlier */
smp_mb__before_atomic();
if (atomic_read(&state.enough))
break;
state.infos[i].state = &state;
state.infos[i].thread =
kthread_run(bch_dirty_init_thread, &state.infos[i],
"bch_dirtcnt[%d]", i);
if (IS_ERR(state.infos[i].thread)) {
pr_err("fails to run thread bch_dirty_init[%d]\n", i);
for (--i; i >= 0; i--)
kthread_stop(state.infos[i].thread);
goto out;
}
atomic_inc(&state.started);
}
out:
/* Must wait for all threads to stop. */
wait_event(state.wait, atomic_read(&state.started) == 0);
rw_unlock(0, c->root);
}
void bch_cached_dev_writeback_init(struct cached_dev *dc)
{
sema_init(&dc->in_flight, 64);
init_rwsem(&dc->writeback_lock);
bch_keybuf_init(&dc->writeback_keys);
dc->writeback_metadata = true;
dc->writeback_running = false;
dc->writeback_consider_fragment = true;
dc->writeback_percent = 10;
dc->writeback_delay = 30;
atomic_long_set(&dc->writeback_rate.rate, 1024);
dc->writeback_rate_minimum = 8;
dc->writeback_rate_update_seconds = WRITEBACK_RATE_UPDATE_SECS_DEFAULT;
dc->writeback_rate_p_term_inverse = 40;
dc->writeback_rate_fp_term_low = 1;
dc->writeback_rate_fp_term_mid = 10;
dc->writeback_rate_fp_term_high = 1000;
dc->writeback_rate_i_term_inverse = 10000;
/* For dc->writeback_lock contention in update_writeback_rate() */
dc->rate_update_retry = 0;
WARN_ON(test_and_clear_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags));
INIT_DELAYED_WORK(&dc->writeback_rate_update, update_writeback_rate);
}
int bch_cached_dev_writeback_start(struct cached_dev *dc)
{
dc->writeback_write_wq = alloc_workqueue("bcache_writeback_wq",
WQ_MEM_RECLAIM, 0);
if (!dc->writeback_write_wq)
return -ENOMEM;
cached_dev_get(dc);
dc->writeback_thread = kthread_create(bch_writeback_thread, dc,
"bcache_writeback");
if (IS_ERR(dc->writeback_thread)) {
cached_dev_put(dc);
destroy_workqueue(dc->writeback_write_wq);
return PTR_ERR(dc->writeback_thread);
}
dc->writeback_running = true;
WARN_ON(test_and_set_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags));
schedule_delayed_work(&dc->writeback_rate_update,
dc->writeback_rate_update_seconds * HZ);
bch_writeback_queue(dc);
return 0;
}
| linux-master | drivers/md/bcache/writeback.c |
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2010 Kent Overstreet <[email protected]>
*
* Uses a block device as cache for other block devices; optimized for SSDs.
* All allocation is done in buckets, which should match the erase block size
* of the device.
*
* Buckets containing cached data are kept on a heap sorted by priority;
* bucket priority is increased on cache hit, and periodically all the buckets
* on the heap have their priority scaled down. This currently is just used as
* an LRU but in the future should allow for more intelligent heuristics.
*
* Buckets have an 8 bit counter; freeing is accomplished by incrementing the
* counter. Garbage collection is used to remove stale pointers.
*
* Indexing is done via a btree; nodes are not necessarily fully sorted, rather
* as keys are inserted we only sort the pages that have not yet been written.
* When garbage collection is run, we resort the entire node.
*
* All configuration is done via sysfs; see Documentation/admin-guide/bcache.rst.
*/
#include "bcache.h"
#include "btree.h"
#include "debug.h"
#include "extents.h"
#include <linux/slab.h>
#include <linux/bitops.h>
#include <linux/hash.h>
#include <linux/kthread.h>
#include <linux/prefetch.h>
#include <linux/random.h>
#include <linux/rcupdate.h>
#include <linux/sched/clock.h>
#include <linux/rculist.h>
#include <linux/delay.h>
#include <trace/events/bcache.h>
/*
* Todo:
* register_bcache: Return errors out to userspace correctly
*
* Writeback: don't undirty key until after a cache flush
*
* Create an iterator for key pointers
*
* On btree write error, mark bucket such that it won't be freed from the cache
*
* Journalling:
* Check for bad keys in replay
* Propagate barriers
* Refcount journal entries in journal_replay
*
* Garbage collection:
* Finish incremental gc
* Gc should free old UUIDs, data for invalid UUIDs
*
* Provide a way to list backing device UUIDs we have data cached for, and
* probably how long it's been since we've seen them, and a way to invalidate
* dirty data for devices that will never be attached again
*
* Keep 1 min/5 min/15 min statistics of how busy a block device has been, so
* that based on that and how much dirty data we have we can keep writeback
* from being starved
*
* Add a tracepoint or somesuch to watch for writeback starvation
*
* When btree depth > 1 and splitting an interior node, we have to make sure
* alloc_bucket() cannot fail. This should be true but is not completely
* obvious.
*
* Plugging?
*
* If data write is less than hard sector size of ssd, round up offset in open
* bucket to the next whole sector
*
* Superblock needs to be fleshed out for multiple cache devices
*
* Add a sysfs tunable for the number of writeback IOs in flight
*
* Add a sysfs tunable for the number of open data buckets
*
* IO tracking: Can we track when one process is doing io on behalf of another?
* IO tracking: Don't use just an average, weigh more recent stuff higher
*
* Test module load/unload
*/
#define MAX_NEED_GC 64
#define MAX_SAVE_PRIO 72
#define MAX_GC_TIMES 100
#define MIN_GC_NODES 100
#define GC_SLEEP_MS 100
#define PTR_DIRTY_BIT (((uint64_t) 1 << 36))
#define PTR_HASH(c, k) \
(((k)->ptr[0] >> c->bucket_bits) | PTR_GEN(k, 0))
static struct workqueue_struct *btree_io_wq;
#define insert_lock(s, b) ((b)->level <= (s)->lock)
static inline struct bset *write_block(struct btree *b)
{
return ((void *) btree_bset_first(b)) + b->written * block_bytes(b->c->cache);
}
static void bch_btree_init_next(struct btree *b)
{
/* If not a leaf node, always sort */
if (b->level && b->keys.nsets)
bch_btree_sort(&b->keys, &b->c->sort);
else
bch_btree_sort_lazy(&b->keys, &b->c->sort);
if (b->written < btree_blocks(b))
bch_bset_init_next(&b->keys, write_block(b),
bset_magic(&b->c->cache->sb));
}
/* Btree key manipulation */
void bkey_put(struct cache_set *c, struct bkey *k)
{
unsigned int i;
for (i = 0; i < KEY_PTRS(k); i++)
if (ptr_available(c, k, i))
atomic_dec_bug(&PTR_BUCKET(c, k, i)->pin);
}
/* Btree IO */
static uint64_t btree_csum_set(struct btree *b, struct bset *i)
{
uint64_t crc = b->key.ptr[0];
void *data = (void *) i + 8, *end = bset_bkey_last(i);
crc = crc64_be(crc, data, end - data);
return crc ^ 0xffffffffffffffffULL;
}
void bch_btree_node_read_done(struct btree *b)
{
const char *err = "bad btree header";
struct bset *i = btree_bset_first(b);
struct btree_iter *iter;
/*
* c->fill_iter can allocate an iterator with more memory space
* than static MAX_BSETS.
* See the comment arount cache_set->fill_iter.
*/
iter = mempool_alloc(&b->c->fill_iter, GFP_NOIO);
iter->size = b->c->cache->sb.bucket_size / b->c->cache->sb.block_size;
iter->used = 0;
#ifdef CONFIG_BCACHE_DEBUG
iter->b = &b->keys;
#endif
if (!i->seq)
goto err;
for (;
b->written < btree_blocks(b) && i->seq == b->keys.set[0].data->seq;
i = write_block(b)) {
err = "unsupported bset version";
if (i->version > BCACHE_BSET_VERSION)
goto err;
err = "bad btree header";
if (b->written + set_blocks(i, block_bytes(b->c->cache)) >
btree_blocks(b))
goto err;
err = "bad magic";
if (i->magic != bset_magic(&b->c->cache->sb))
goto err;
err = "bad checksum";
switch (i->version) {
case 0:
if (i->csum != csum_set(i))
goto err;
break;
case BCACHE_BSET_VERSION:
if (i->csum != btree_csum_set(b, i))
goto err;
break;
}
err = "empty set";
if (i != b->keys.set[0].data && !i->keys)
goto err;
bch_btree_iter_push(iter, i->start, bset_bkey_last(i));
b->written += set_blocks(i, block_bytes(b->c->cache));
}
err = "corrupted btree";
for (i = write_block(b);
bset_sector_offset(&b->keys, i) < KEY_SIZE(&b->key);
i = ((void *) i) + block_bytes(b->c->cache))
if (i->seq == b->keys.set[0].data->seq)
goto err;
bch_btree_sort_and_fix_extents(&b->keys, iter, &b->c->sort);
i = b->keys.set[0].data;
err = "short btree key";
if (b->keys.set[0].size &&
bkey_cmp(&b->key, &b->keys.set[0].end) < 0)
goto err;
if (b->written < btree_blocks(b))
bch_bset_init_next(&b->keys, write_block(b),
bset_magic(&b->c->cache->sb));
out:
mempool_free(iter, &b->c->fill_iter);
return;
err:
set_btree_node_io_error(b);
bch_cache_set_error(b->c, "%s at bucket %zu, block %u, %u keys",
err, PTR_BUCKET_NR(b->c, &b->key, 0),
bset_block_offset(b, i), i->keys);
goto out;
}
static void btree_node_read_endio(struct bio *bio)
{
struct closure *cl = bio->bi_private;
closure_put(cl);
}
static void bch_btree_node_read(struct btree *b)
{
uint64_t start_time = local_clock();
struct closure cl;
struct bio *bio;
trace_bcache_btree_read(b);
closure_init_stack(&cl);
bio = bch_bbio_alloc(b->c);
bio->bi_iter.bi_size = KEY_SIZE(&b->key) << 9;
bio->bi_end_io = btree_node_read_endio;
bio->bi_private = &cl;
bio->bi_opf = REQ_OP_READ | REQ_META;
bch_bio_map(bio, b->keys.set[0].data);
bch_submit_bbio(bio, b->c, &b->key, 0);
closure_sync(&cl);
if (bio->bi_status)
set_btree_node_io_error(b);
bch_bbio_free(bio, b->c);
if (btree_node_io_error(b))
goto err;
bch_btree_node_read_done(b);
bch_time_stats_update(&b->c->btree_read_time, start_time);
return;
err:
bch_cache_set_error(b->c, "io error reading bucket %zu",
PTR_BUCKET_NR(b->c, &b->key, 0));
}
static void btree_complete_write(struct btree *b, struct btree_write *w)
{
if (w->prio_blocked &&
!atomic_sub_return(w->prio_blocked, &b->c->prio_blocked))
wake_up_allocators(b->c);
if (w->journal) {
atomic_dec_bug(w->journal);
__closure_wake_up(&b->c->journal.wait);
}
w->prio_blocked = 0;
w->journal = NULL;
}
static void btree_node_write_unlock(struct closure *cl)
{
struct btree *b = container_of(cl, struct btree, io);
up(&b->io_mutex);
}
static void __btree_node_write_done(struct closure *cl)
{
struct btree *b = container_of(cl, struct btree, io);
struct btree_write *w = btree_prev_write(b);
bch_bbio_free(b->bio, b->c);
b->bio = NULL;
btree_complete_write(b, w);
if (btree_node_dirty(b))
queue_delayed_work(btree_io_wq, &b->work, 30 * HZ);
closure_return_with_destructor(cl, btree_node_write_unlock);
}
static void btree_node_write_done(struct closure *cl)
{
struct btree *b = container_of(cl, struct btree, io);
bio_free_pages(b->bio);
__btree_node_write_done(cl);
}
static void btree_node_write_endio(struct bio *bio)
{
struct closure *cl = bio->bi_private;
struct btree *b = container_of(cl, struct btree, io);
if (bio->bi_status)
set_btree_node_io_error(b);
bch_bbio_count_io_errors(b->c, bio, bio->bi_status, "writing btree");
closure_put(cl);
}
static void do_btree_node_write(struct btree *b)
{
struct closure *cl = &b->io;
struct bset *i = btree_bset_last(b);
BKEY_PADDED(key) k;
i->version = BCACHE_BSET_VERSION;
i->csum = btree_csum_set(b, i);
BUG_ON(b->bio);
b->bio = bch_bbio_alloc(b->c);
b->bio->bi_end_io = btree_node_write_endio;
b->bio->bi_private = cl;
b->bio->bi_iter.bi_size = roundup(set_bytes(i), block_bytes(b->c->cache));
b->bio->bi_opf = REQ_OP_WRITE | REQ_META | REQ_FUA;
bch_bio_map(b->bio, i);
/*
* If we're appending to a leaf node, we don't technically need FUA -
* this write just needs to be persisted before the next journal write,
* which will be marked FLUSH|FUA.
*
* Similarly if we're writing a new btree root - the pointer is going to
* be in the next journal entry.
*
* But if we're writing a new btree node (that isn't a root) or
* appending to a non leaf btree node, we need either FUA or a flush
* when we write the parent with the new pointer. FUA is cheaper than a
* flush, and writes appending to leaf nodes aren't blocking anything so
* just make all btree node writes FUA to keep things sane.
*/
bkey_copy(&k.key, &b->key);
SET_PTR_OFFSET(&k.key, 0, PTR_OFFSET(&k.key, 0) +
bset_sector_offset(&b->keys, i));
if (!bch_bio_alloc_pages(b->bio, __GFP_NOWARN|GFP_NOWAIT)) {
struct bio_vec *bv;
void *addr = (void *) ((unsigned long) i & ~(PAGE_SIZE - 1));
struct bvec_iter_all iter_all;
bio_for_each_segment_all(bv, b->bio, iter_all) {
memcpy(page_address(bv->bv_page), addr, PAGE_SIZE);
addr += PAGE_SIZE;
}
bch_submit_bbio(b->bio, b->c, &k.key, 0);
continue_at(cl, btree_node_write_done, NULL);
} else {
/*
* No problem for multipage bvec since the bio is
* just allocated
*/
b->bio->bi_vcnt = 0;
bch_bio_map(b->bio, i);
bch_submit_bbio(b->bio, b->c, &k.key, 0);
closure_sync(cl);
continue_at_nobarrier(cl, __btree_node_write_done, NULL);
}
}
void __bch_btree_node_write(struct btree *b, struct closure *parent)
{
struct bset *i = btree_bset_last(b);
lockdep_assert_held(&b->write_lock);
trace_bcache_btree_write(b);
BUG_ON(current->bio_list);
BUG_ON(b->written >= btree_blocks(b));
BUG_ON(b->written && !i->keys);
BUG_ON(btree_bset_first(b)->seq != i->seq);
bch_check_keys(&b->keys, "writing");
cancel_delayed_work(&b->work);
/* If caller isn't waiting for write, parent refcount is cache set */
down(&b->io_mutex);
closure_init(&b->io, parent ?: &b->c->cl);
clear_bit(BTREE_NODE_dirty, &b->flags);
change_bit(BTREE_NODE_write_idx, &b->flags);
do_btree_node_write(b);
atomic_long_add(set_blocks(i, block_bytes(b->c->cache)) * b->c->cache->sb.block_size,
&b->c->cache->btree_sectors_written);
b->written += set_blocks(i, block_bytes(b->c->cache));
}
void bch_btree_node_write(struct btree *b, struct closure *parent)
{
unsigned int nsets = b->keys.nsets;
lockdep_assert_held(&b->lock);
__bch_btree_node_write(b, parent);
/*
* do verify if there was more than one set initially (i.e. we did a
* sort) and we sorted down to a single set:
*/
if (nsets && !b->keys.nsets)
bch_btree_verify(b);
bch_btree_init_next(b);
}
static void bch_btree_node_write_sync(struct btree *b)
{
struct closure cl;
closure_init_stack(&cl);
mutex_lock(&b->write_lock);
bch_btree_node_write(b, &cl);
mutex_unlock(&b->write_lock);
closure_sync(&cl);
}
static void btree_node_write_work(struct work_struct *w)
{
struct btree *b = container_of(to_delayed_work(w), struct btree, work);
mutex_lock(&b->write_lock);
if (btree_node_dirty(b))
__bch_btree_node_write(b, NULL);
mutex_unlock(&b->write_lock);
}
static void bch_btree_leaf_dirty(struct btree *b, atomic_t *journal_ref)
{
struct bset *i = btree_bset_last(b);
struct btree_write *w = btree_current_write(b);
lockdep_assert_held(&b->write_lock);
BUG_ON(!b->written);
BUG_ON(!i->keys);
if (!btree_node_dirty(b))
queue_delayed_work(btree_io_wq, &b->work, 30 * HZ);
set_btree_node_dirty(b);
/*
* w->journal is always the oldest journal pin of all bkeys
* in the leaf node, to make sure the oldest jset seq won't
* be increased before this btree node is flushed.
*/
if (journal_ref) {
if (w->journal &&
journal_pin_cmp(b->c, w->journal, journal_ref)) {
atomic_dec_bug(w->journal);
w->journal = NULL;
}
if (!w->journal) {
w->journal = journal_ref;
atomic_inc(w->journal);
}
}
/* Force write if set is too big */
if (set_bytes(i) > PAGE_SIZE - 48 &&
!current->bio_list)
bch_btree_node_write(b, NULL);
}
/*
* Btree in memory cache - allocation/freeing
* mca -> memory cache
*/
#define mca_reserve(c) (((!IS_ERR_OR_NULL(c->root) && c->root->level) \
? c->root->level : 1) * 8 + 16)
#define mca_can_free(c) \
max_t(int, 0, c->btree_cache_used - mca_reserve(c))
static void mca_data_free(struct btree *b)
{
BUG_ON(b->io_mutex.count != 1);
bch_btree_keys_free(&b->keys);
b->c->btree_cache_used--;
list_move(&b->list, &b->c->btree_cache_freed);
}
static void mca_bucket_free(struct btree *b)
{
BUG_ON(btree_node_dirty(b));
b->key.ptr[0] = 0;
hlist_del_init_rcu(&b->hash);
list_move(&b->list, &b->c->btree_cache_freeable);
}
static unsigned int btree_order(struct bkey *k)
{
return ilog2(KEY_SIZE(k) / PAGE_SECTORS ?: 1);
}
static void mca_data_alloc(struct btree *b, struct bkey *k, gfp_t gfp)
{
if (!bch_btree_keys_alloc(&b->keys,
max_t(unsigned int,
ilog2(b->c->btree_pages),
btree_order(k)),
gfp)) {
b->c->btree_cache_used++;
list_move(&b->list, &b->c->btree_cache);
} else {
list_move(&b->list, &b->c->btree_cache_freed);
}
}
#define cmp_int(l, r) ((l > r) - (l < r))
#ifdef CONFIG_PROVE_LOCKING
static int btree_lock_cmp_fn(const struct lockdep_map *_a,
const struct lockdep_map *_b)
{
const struct btree *a = container_of(_a, struct btree, lock.dep_map);
const struct btree *b = container_of(_b, struct btree, lock.dep_map);
return -cmp_int(a->level, b->level) ?: bkey_cmp(&a->key, &b->key);
}
static void btree_lock_print_fn(const struct lockdep_map *map)
{
const struct btree *b = container_of(map, struct btree, lock.dep_map);
printk(KERN_CONT " l=%u %llu:%llu", b->level,
KEY_INODE(&b->key), KEY_OFFSET(&b->key));
}
#endif
static struct btree *mca_bucket_alloc(struct cache_set *c,
struct bkey *k, gfp_t gfp)
{
/*
* kzalloc() is necessary here for initialization,
* see code comments in bch_btree_keys_init().
*/
struct btree *b = kzalloc(sizeof(struct btree), gfp);
if (!b)
return NULL;
init_rwsem(&b->lock);
lock_set_cmp_fn(&b->lock, btree_lock_cmp_fn, btree_lock_print_fn);
mutex_init(&b->write_lock);
lockdep_set_novalidate_class(&b->write_lock);
INIT_LIST_HEAD(&b->list);
INIT_DELAYED_WORK(&b->work, btree_node_write_work);
b->c = c;
sema_init(&b->io_mutex, 1);
mca_data_alloc(b, k, gfp);
return b;
}
static int mca_reap(struct btree *b, unsigned int min_order, bool flush)
{
struct closure cl;
closure_init_stack(&cl);
lockdep_assert_held(&b->c->bucket_lock);
if (!down_write_trylock(&b->lock))
return -ENOMEM;
BUG_ON(btree_node_dirty(b) && !b->keys.set[0].data);
if (b->keys.page_order < min_order)
goto out_unlock;
if (!flush) {
if (btree_node_dirty(b))
goto out_unlock;
if (down_trylock(&b->io_mutex))
goto out_unlock;
up(&b->io_mutex);
}
retry:
/*
* BTREE_NODE_dirty might be cleared in btree_flush_btree() by
* __bch_btree_node_write(). To avoid an extra flush, acquire
* b->write_lock before checking BTREE_NODE_dirty bit.
*/
mutex_lock(&b->write_lock);
/*
* If this btree node is selected in btree_flush_write() by journal
* code, delay and retry until the node is flushed by journal code
* and BTREE_NODE_journal_flush bit cleared by btree_flush_write().
*/
if (btree_node_journal_flush(b)) {
pr_debug("bnode %p is flushing by journal, retry\n", b);
mutex_unlock(&b->write_lock);
udelay(1);
goto retry;
}
if (btree_node_dirty(b))
__bch_btree_node_write(b, &cl);
mutex_unlock(&b->write_lock);
closure_sync(&cl);
/* wait for any in flight btree write */
down(&b->io_mutex);
up(&b->io_mutex);
return 0;
out_unlock:
rw_unlock(true, b);
return -ENOMEM;
}
static unsigned long bch_mca_scan(struct shrinker *shrink,
struct shrink_control *sc)
{
struct cache_set *c = container_of(shrink, struct cache_set, shrink);
struct btree *b, *t;
unsigned long i, nr = sc->nr_to_scan;
unsigned long freed = 0;
unsigned int btree_cache_used;
if (c->shrinker_disabled)
return SHRINK_STOP;
if (c->btree_cache_alloc_lock)
return SHRINK_STOP;
/* Return -1 if we can't do anything right now */
if (sc->gfp_mask & __GFP_IO)
mutex_lock(&c->bucket_lock);
else if (!mutex_trylock(&c->bucket_lock))
return -1;
/*
* It's _really_ critical that we don't free too many btree nodes - we
* have to always leave ourselves a reserve. The reserve is how we
* guarantee that allocating memory for a new btree node can always
* succeed, so that inserting keys into the btree can always succeed and
* IO can always make forward progress:
*/
nr /= c->btree_pages;
if (nr == 0)
nr = 1;
nr = min_t(unsigned long, nr, mca_can_free(c));
i = 0;
btree_cache_used = c->btree_cache_used;
list_for_each_entry_safe_reverse(b, t, &c->btree_cache_freeable, list) {
if (nr <= 0)
goto out;
if (!mca_reap(b, 0, false)) {
mca_data_free(b);
rw_unlock(true, b);
freed++;
}
nr--;
i++;
}
list_for_each_entry_safe_reverse(b, t, &c->btree_cache, list) {
if (nr <= 0 || i >= btree_cache_used)
goto out;
if (!mca_reap(b, 0, false)) {
mca_bucket_free(b);
mca_data_free(b);
rw_unlock(true, b);
freed++;
}
nr--;
i++;
}
out:
mutex_unlock(&c->bucket_lock);
return freed * c->btree_pages;
}
static unsigned long bch_mca_count(struct shrinker *shrink,
struct shrink_control *sc)
{
struct cache_set *c = container_of(shrink, struct cache_set, shrink);
if (c->shrinker_disabled)
return 0;
if (c->btree_cache_alloc_lock)
return 0;
return mca_can_free(c) * c->btree_pages;
}
void bch_btree_cache_free(struct cache_set *c)
{
struct btree *b;
struct closure cl;
closure_init_stack(&cl);
if (c->shrink.list.next)
unregister_shrinker(&c->shrink);
mutex_lock(&c->bucket_lock);
#ifdef CONFIG_BCACHE_DEBUG
if (c->verify_data)
list_move(&c->verify_data->list, &c->btree_cache);
free_pages((unsigned long) c->verify_ondisk, ilog2(meta_bucket_pages(&c->cache->sb)));
#endif
list_splice(&c->btree_cache_freeable,
&c->btree_cache);
while (!list_empty(&c->btree_cache)) {
b = list_first_entry(&c->btree_cache, struct btree, list);
/*
* This function is called by cache_set_free(), no I/O
* request on cache now, it is unnecessary to acquire
* b->write_lock before clearing BTREE_NODE_dirty anymore.
*/
if (btree_node_dirty(b)) {
btree_complete_write(b, btree_current_write(b));
clear_bit(BTREE_NODE_dirty, &b->flags);
}
mca_data_free(b);
}
while (!list_empty(&c->btree_cache_freed)) {
b = list_first_entry(&c->btree_cache_freed,
struct btree, list);
list_del(&b->list);
cancel_delayed_work_sync(&b->work);
kfree(b);
}
mutex_unlock(&c->bucket_lock);
}
int bch_btree_cache_alloc(struct cache_set *c)
{
unsigned int i;
for (i = 0; i < mca_reserve(c); i++)
if (!mca_bucket_alloc(c, &ZERO_KEY, GFP_KERNEL))
return -ENOMEM;
list_splice_init(&c->btree_cache,
&c->btree_cache_freeable);
#ifdef CONFIG_BCACHE_DEBUG
mutex_init(&c->verify_lock);
c->verify_ondisk = (void *)
__get_free_pages(GFP_KERNEL|__GFP_COMP,
ilog2(meta_bucket_pages(&c->cache->sb)));
if (!c->verify_ondisk) {
/*
* Don't worry about the mca_rereserve buckets
* allocated in previous for-loop, they will be
* handled properly in bch_cache_set_unregister().
*/
return -ENOMEM;
}
c->verify_data = mca_bucket_alloc(c, &ZERO_KEY, GFP_KERNEL);
if (c->verify_data &&
c->verify_data->keys.set->data)
list_del_init(&c->verify_data->list);
else
c->verify_data = NULL;
#endif
c->shrink.count_objects = bch_mca_count;
c->shrink.scan_objects = bch_mca_scan;
c->shrink.seeks = 4;
c->shrink.batch = c->btree_pages * 2;
if (register_shrinker(&c->shrink, "md-bcache:%pU", c->set_uuid))
pr_warn("bcache: %s: could not register shrinker\n",
__func__);
return 0;
}
/* Btree in memory cache - hash table */
static struct hlist_head *mca_hash(struct cache_set *c, struct bkey *k)
{
return &c->bucket_hash[hash_32(PTR_HASH(c, k), BUCKET_HASH_BITS)];
}
static struct btree *mca_find(struct cache_set *c, struct bkey *k)
{
struct btree *b;
rcu_read_lock();
hlist_for_each_entry_rcu(b, mca_hash(c, k), hash)
if (PTR_HASH(c, &b->key) == PTR_HASH(c, k))
goto out;
b = NULL;
out:
rcu_read_unlock();
return b;
}
static int mca_cannibalize_lock(struct cache_set *c, struct btree_op *op)
{
spin_lock(&c->btree_cannibalize_lock);
if (likely(c->btree_cache_alloc_lock == NULL)) {
c->btree_cache_alloc_lock = current;
} else if (c->btree_cache_alloc_lock != current) {
if (op)
prepare_to_wait(&c->btree_cache_wait, &op->wait,
TASK_UNINTERRUPTIBLE);
spin_unlock(&c->btree_cannibalize_lock);
return -EINTR;
}
spin_unlock(&c->btree_cannibalize_lock);
return 0;
}
static struct btree *mca_cannibalize(struct cache_set *c, struct btree_op *op,
struct bkey *k)
{
struct btree *b;
trace_bcache_btree_cache_cannibalize(c);
if (mca_cannibalize_lock(c, op))
return ERR_PTR(-EINTR);
list_for_each_entry_reverse(b, &c->btree_cache, list)
if (!mca_reap(b, btree_order(k), false))
return b;
list_for_each_entry_reverse(b, &c->btree_cache, list)
if (!mca_reap(b, btree_order(k), true))
return b;
WARN(1, "btree cache cannibalize failed\n");
return ERR_PTR(-ENOMEM);
}
/*
* We can only have one thread cannibalizing other cached btree nodes at a time,
* or we'll deadlock. We use an open coded mutex to ensure that, which a
* cannibalize_bucket() will take. This means every time we unlock the root of
* the btree, we need to release this lock if we have it held.
*/
void bch_cannibalize_unlock(struct cache_set *c)
{
spin_lock(&c->btree_cannibalize_lock);
if (c->btree_cache_alloc_lock == current) {
c->btree_cache_alloc_lock = NULL;
wake_up(&c->btree_cache_wait);
}
spin_unlock(&c->btree_cannibalize_lock);
}
static struct btree *mca_alloc(struct cache_set *c, struct btree_op *op,
struct bkey *k, int level)
{
struct btree *b;
BUG_ON(current->bio_list);
lockdep_assert_held(&c->bucket_lock);
if (mca_find(c, k))
return NULL;
/* btree_free() doesn't free memory; it sticks the node on the end of
* the list. Check if there's any freed nodes there:
*/
list_for_each_entry(b, &c->btree_cache_freeable, list)
if (!mca_reap(b, btree_order(k), false))
goto out;
/* We never free struct btree itself, just the memory that holds the on
* disk node. Check the freed list before allocating a new one:
*/
list_for_each_entry(b, &c->btree_cache_freed, list)
if (!mca_reap(b, 0, false)) {
mca_data_alloc(b, k, __GFP_NOWARN|GFP_NOIO);
if (!b->keys.set[0].data)
goto err;
else
goto out;
}
b = mca_bucket_alloc(c, k, __GFP_NOWARN|GFP_NOIO);
if (!b)
goto err;
BUG_ON(!down_write_trylock(&b->lock));
if (!b->keys.set->data)
goto err;
out:
BUG_ON(b->io_mutex.count != 1);
bkey_copy(&b->key, k);
list_move(&b->list, &c->btree_cache);
hlist_del_init_rcu(&b->hash);
hlist_add_head_rcu(&b->hash, mca_hash(c, k));
lock_set_subclass(&b->lock.dep_map, level + 1, _THIS_IP_);
b->parent = (void *) ~0UL;
b->flags = 0;
b->written = 0;
b->level = level;
if (!b->level)
bch_btree_keys_init(&b->keys, &bch_extent_keys_ops,
&b->c->expensive_debug_checks);
else
bch_btree_keys_init(&b->keys, &bch_btree_keys_ops,
&b->c->expensive_debug_checks);
return b;
err:
if (b)
rw_unlock(true, b);
b = mca_cannibalize(c, op, k);
if (!IS_ERR(b))
goto out;
return b;
}
/*
* bch_btree_node_get - find a btree node in the cache and lock it, reading it
* in from disk if necessary.
*
* If IO is necessary and running under submit_bio_noacct, returns -EAGAIN.
*
* The btree node will have either a read or a write lock held, depending on
* level and op->lock.
*/
struct btree *bch_btree_node_get(struct cache_set *c, struct btree_op *op,
struct bkey *k, int level, bool write,
struct btree *parent)
{
int i = 0;
struct btree *b;
BUG_ON(level < 0);
retry:
b = mca_find(c, k);
if (!b) {
if (current->bio_list)
return ERR_PTR(-EAGAIN);
mutex_lock(&c->bucket_lock);
b = mca_alloc(c, op, k, level);
mutex_unlock(&c->bucket_lock);
if (!b)
goto retry;
if (IS_ERR(b))
return b;
bch_btree_node_read(b);
if (!write)
downgrade_write(&b->lock);
} else {
rw_lock(write, b, level);
if (PTR_HASH(c, &b->key) != PTR_HASH(c, k)) {
rw_unlock(write, b);
goto retry;
}
BUG_ON(b->level != level);
}
if (btree_node_io_error(b)) {
rw_unlock(write, b);
return ERR_PTR(-EIO);
}
BUG_ON(!b->written);
b->parent = parent;
for (; i <= b->keys.nsets && b->keys.set[i].size; i++) {
prefetch(b->keys.set[i].tree);
prefetch(b->keys.set[i].data);
}
for (; i <= b->keys.nsets; i++)
prefetch(b->keys.set[i].data);
return b;
}
static void btree_node_prefetch(struct btree *parent, struct bkey *k)
{
struct btree *b;
mutex_lock(&parent->c->bucket_lock);
b = mca_alloc(parent->c, NULL, k, parent->level - 1);
mutex_unlock(&parent->c->bucket_lock);
if (!IS_ERR_OR_NULL(b)) {
b->parent = parent;
bch_btree_node_read(b);
rw_unlock(true, b);
}
}
/* Btree alloc */
static void btree_node_free(struct btree *b)
{
trace_bcache_btree_node_free(b);
BUG_ON(b == b->c->root);
retry:
mutex_lock(&b->write_lock);
/*
* If the btree node is selected and flushing in btree_flush_write(),
* delay and retry until the BTREE_NODE_journal_flush bit cleared,
* then it is safe to free the btree node here. Otherwise this btree
* node will be in race condition.
*/
if (btree_node_journal_flush(b)) {
mutex_unlock(&b->write_lock);
pr_debug("bnode %p journal_flush set, retry\n", b);
udelay(1);
goto retry;
}
if (btree_node_dirty(b)) {
btree_complete_write(b, btree_current_write(b));
clear_bit(BTREE_NODE_dirty, &b->flags);
}
mutex_unlock(&b->write_lock);
cancel_delayed_work(&b->work);
mutex_lock(&b->c->bucket_lock);
bch_bucket_free(b->c, &b->key);
mca_bucket_free(b);
mutex_unlock(&b->c->bucket_lock);
}
struct btree *__bch_btree_node_alloc(struct cache_set *c, struct btree_op *op,
int level, bool wait,
struct btree *parent)
{
BKEY_PADDED(key) k;
struct btree *b;
mutex_lock(&c->bucket_lock);
retry:
/* return ERR_PTR(-EAGAIN) when it fails */
b = ERR_PTR(-EAGAIN);
if (__bch_bucket_alloc_set(c, RESERVE_BTREE, &k.key, wait))
goto err;
bkey_put(c, &k.key);
SET_KEY_SIZE(&k.key, c->btree_pages * PAGE_SECTORS);
b = mca_alloc(c, op, &k.key, level);
if (IS_ERR(b))
goto err_free;
if (!b) {
cache_bug(c,
"Tried to allocate bucket that was in btree cache");
goto retry;
}
b->parent = parent;
bch_bset_init_next(&b->keys, b->keys.set->data, bset_magic(&b->c->cache->sb));
mutex_unlock(&c->bucket_lock);
trace_bcache_btree_node_alloc(b);
return b;
err_free:
bch_bucket_free(c, &k.key);
err:
mutex_unlock(&c->bucket_lock);
trace_bcache_btree_node_alloc_fail(c);
return b;
}
static struct btree *bch_btree_node_alloc(struct cache_set *c,
struct btree_op *op, int level,
struct btree *parent)
{
return __bch_btree_node_alloc(c, op, level, op != NULL, parent);
}
static struct btree *btree_node_alloc_replacement(struct btree *b,
struct btree_op *op)
{
struct btree *n = bch_btree_node_alloc(b->c, op, b->level, b->parent);
if (!IS_ERR(n)) {
mutex_lock(&n->write_lock);
bch_btree_sort_into(&b->keys, &n->keys, &b->c->sort);
bkey_copy_key(&n->key, &b->key);
mutex_unlock(&n->write_lock);
}
return n;
}
static void make_btree_freeing_key(struct btree *b, struct bkey *k)
{
unsigned int i;
mutex_lock(&b->c->bucket_lock);
atomic_inc(&b->c->prio_blocked);
bkey_copy(k, &b->key);
bkey_copy_key(k, &ZERO_KEY);
for (i = 0; i < KEY_PTRS(k); i++)
SET_PTR_GEN(k, i,
bch_inc_gen(b->c->cache,
PTR_BUCKET(b->c, &b->key, i)));
mutex_unlock(&b->c->bucket_lock);
}
static int btree_check_reserve(struct btree *b, struct btree_op *op)
{
struct cache_set *c = b->c;
struct cache *ca = c->cache;
unsigned int reserve = (c->root->level - b->level) * 2 + 1;
mutex_lock(&c->bucket_lock);
if (fifo_used(&ca->free[RESERVE_BTREE]) < reserve) {
if (op)
prepare_to_wait(&c->btree_cache_wait, &op->wait,
TASK_UNINTERRUPTIBLE);
mutex_unlock(&c->bucket_lock);
return -EINTR;
}
mutex_unlock(&c->bucket_lock);
return mca_cannibalize_lock(b->c, op);
}
/* Garbage collection */
static uint8_t __bch_btree_mark_key(struct cache_set *c, int level,
struct bkey *k)
{
uint8_t stale = 0;
unsigned int i;
struct bucket *g;
/*
* ptr_invalid() can't return true for the keys that mark btree nodes as
* freed, but since ptr_bad() returns true we'll never actually use them
* for anything and thus we don't want mark their pointers here
*/
if (!bkey_cmp(k, &ZERO_KEY))
return stale;
for (i = 0; i < KEY_PTRS(k); i++) {
if (!ptr_available(c, k, i))
continue;
g = PTR_BUCKET(c, k, i);
if (gen_after(g->last_gc, PTR_GEN(k, i)))
g->last_gc = PTR_GEN(k, i);
if (ptr_stale(c, k, i)) {
stale = max(stale, ptr_stale(c, k, i));
continue;
}
cache_bug_on(GC_MARK(g) &&
(GC_MARK(g) == GC_MARK_METADATA) != (level != 0),
c, "inconsistent ptrs: mark = %llu, level = %i",
GC_MARK(g), level);
if (level)
SET_GC_MARK(g, GC_MARK_METADATA);
else if (KEY_DIRTY(k))
SET_GC_MARK(g, GC_MARK_DIRTY);
else if (!GC_MARK(g))
SET_GC_MARK(g, GC_MARK_RECLAIMABLE);
/* guard against overflow */
SET_GC_SECTORS_USED(g, min_t(unsigned int,
GC_SECTORS_USED(g) + KEY_SIZE(k),
MAX_GC_SECTORS_USED));
BUG_ON(!GC_SECTORS_USED(g));
}
return stale;
}
#define btree_mark_key(b, k) __bch_btree_mark_key(b->c, b->level, k)
void bch_initial_mark_key(struct cache_set *c, int level, struct bkey *k)
{
unsigned int i;
for (i = 0; i < KEY_PTRS(k); i++)
if (ptr_available(c, k, i) &&
!ptr_stale(c, k, i)) {
struct bucket *b = PTR_BUCKET(c, k, i);
b->gen = PTR_GEN(k, i);
if (level && bkey_cmp(k, &ZERO_KEY))
b->prio = BTREE_PRIO;
else if (!level && b->prio == BTREE_PRIO)
b->prio = INITIAL_PRIO;
}
__bch_btree_mark_key(c, level, k);
}
void bch_update_bucket_in_use(struct cache_set *c, struct gc_stat *stats)
{
stats->in_use = (c->nbuckets - c->avail_nbuckets) * 100 / c->nbuckets;
}
static bool btree_gc_mark_node(struct btree *b, struct gc_stat *gc)
{
uint8_t stale = 0;
unsigned int keys = 0, good_keys = 0;
struct bkey *k;
struct btree_iter iter;
struct bset_tree *t;
gc->nodes++;
for_each_key_filter(&b->keys, k, &iter, bch_ptr_invalid) {
stale = max(stale, btree_mark_key(b, k));
keys++;
if (bch_ptr_bad(&b->keys, k))
continue;
gc->key_bytes += bkey_u64s(k);
gc->nkeys++;
good_keys++;
gc->data += KEY_SIZE(k);
}
for (t = b->keys.set; t <= &b->keys.set[b->keys.nsets]; t++)
btree_bug_on(t->size &&
bset_written(&b->keys, t) &&
bkey_cmp(&b->key, &t->end) < 0,
b, "found short btree key in gc");
if (b->c->gc_always_rewrite)
return true;
if (stale > 10)
return true;
if ((keys - good_keys) * 2 > keys)
return true;
return false;
}
#define GC_MERGE_NODES 4U
struct gc_merge_info {
struct btree *b;
unsigned int keys;
};
static int bch_btree_insert_node(struct btree *b, struct btree_op *op,
struct keylist *insert_keys,
atomic_t *journal_ref,
struct bkey *replace_key);
static int btree_gc_coalesce(struct btree *b, struct btree_op *op,
struct gc_stat *gc, struct gc_merge_info *r)
{
unsigned int i, nodes = 0, keys = 0, blocks;
struct btree *new_nodes[GC_MERGE_NODES];
struct keylist keylist;
struct closure cl;
struct bkey *k;
bch_keylist_init(&keylist);
if (btree_check_reserve(b, NULL))
return 0;
memset(new_nodes, 0, sizeof(new_nodes));
closure_init_stack(&cl);
while (nodes < GC_MERGE_NODES && !IS_ERR(r[nodes].b))
keys += r[nodes++].keys;
blocks = btree_default_blocks(b->c) * 2 / 3;
if (nodes < 2 ||
__set_blocks(b->keys.set[0].data, keys,
block_bytes(b->c->cache)) > blocks * (nodes - 1))
return 0;
for (i = 0; i < nodes; i++) {
new_nodes[i] = btree_node_alloc_replacement(r[i].b, NULL);
if (IS_ERR(new_nodes[i]))
goto out_nocoalesce;
}
/*
* We have to check the reserve here, after we've allocated our new
* nodes, to make sure the insert below will succeed - we also check
* before as an optimization to potentially avoid a bunch of expensive
* allocs/sorts
*/
if (btree_check_reserve(b, NULL))
goto out_nocoalesce;
for (i = 0; i < nodes; i++)
mutex_lock(&new_nodes[i]->write_lock);
for (i = nodes - 1; i > 0; --i) {
struct bset *n1 = btree_bset_first(new_nodes[i]);
struct bset *n2 = btree_bset_first(new_nodes[i - 1]);
struct bkey *k, *last = NULL;
keys = 0;
if (i > 1) {
for (k = n2->start;
k < bset_bkey_last(n2);
k = bkey_next(k)) {
if (__set_blocks(n1, n1->keys + keys +
bkey_u64s(k),
block_bytes(b->c->cache)) > blocks)
break;
last = k;
keys += bkey_u64s(k);
}
} else {
/*
* Last node we're not getting rid of - we're getting
* rid of the node at r[0]. Have to try and fit all of
* the remaining keys into this node; we can't ensure
* they will always fit due to rounding and variable
* length keys (shouldn't be possible in practice,
* though)
*/
if (__set_blocks(n1, n1->keys + n2->keys,
block_bytes(b->c->cache)) >
btree_blocks(new_nodes[i]))
goto out_unlock_nocoalesce;
keys = n2->keys;
/* Take the key of the node we're getting rid of */
last = &r->b->key;
}
BUG_ON(__set_blocks(n1, n1->keys + keys, block_bytes(b->c->cache)) >
btree_blocks(new_nodes[i]));
if (last)
bkey_copy_key(&new_nodes[i]->key, last);
memcpy(bset_bkey_last(n1),
n2->start,
(void *) bset_bkey_idx(n2, keys) - (void *) n2->start);
n1->keys += keys;
r[i].keys = n1->keys;
memmove(n2->start,
bset_bkey_idx(n2, keys),
(void *) bset_bkey_last(n2) -
(void *) bset_bkey_idx(n2, keys));
n2->keys -= keys;
if (__bch_keylist_realloc(&keylist,
bkey_u64s(&new_nodes[i]->key)))
goto out_unlock_nocoalesce;
bch_btree_node_write(new_nodes[i], &cl);
bch_keylist_add(&keylist, &new_nodes[i]->key);
}
for (i = 0; i < nodes; i++)
mutex_unlock(&new_nodes[i]->write_lock);
closure_sync(&cl);
/* We emptied out this node */
BUG_ON(btree_bset_first(new_nodes[0])->keys);
btree_node_free(new_nodes[0]);
rw_unlock(true, new_nodes[0]);
new_nodes[0] = NULL;
for (i = 0; i < nodes; i++) {
if (__bch_keylist_realloc(&keylist, bkey_u64s(&r[i].b->key)))
goto out_nocoalesce;
make_btree_freeing_key(r[i].b, keylist.top);
bch_keylist_push(&keylist);
}
bch_btree_insert_node(b, op, &keylist, NULL, NULL);
BUG_ON(!bch_keylist_empty(&keylist));
for (i = 0; i < nodes; i++) {
btree_node_free(r[i].b);
rw_unlock(true, r[i].b);
r[i].b = new_nodes[i];
}
memmove(r, r + 1, sizeof(r[0]) * (nodes - 1));
r[nodes - 1].b = ERR_PTR(-EINTR);
trace_bcache_btree_gc_coalesce(nodes);
gc->nodes--;
bch_keylist_free(&keylist);
/* Invalidated our iterator */
return -EINTR;
out_unlock_nocoalesce:
for (i = 0; i < nodes; i++)
mutex_unlock(&new_nodes[i]->write_lock);
out_nocoalesce:
closure_sync(&cl);
while ((k = bch_keylist_pop(&keylist)))
if (!bkey_cmp(k, &ZERO_KEY))
atomic_dec(&b->c->prio_blocked);
bch_keylist_free(&keylist);
for (i = 0; i < nodes; i++)
if (!IS_ERR(new_nodes[i])) {
btree_node_free(new_nodes[i]);
rw_unlock(true, new_nodes[i]);
}
return 0;
}
static int btree_gc_rewrite_node(struct btree *b, struct btree_op *op,
struct btree *replace)
{
struct keylist keys;
struct btree *n;
if (btree_check_reserve(b, NULL))
return 0;
n = btree_node_alloc_replacement(replace, NULL);
/* recheck reserve after allocating replacement node */
if (btree_check_reserve(b, NULL)) {
btree_node_free(n);
rw_unlock(true, n);
return 0;
}
bch_btree_node_write_sync(n);
bch_keylist_init(&keys);
bch_keylist_add(&keys, &n->key);
make_btree_freeing_key(replace, keys.top);
bch_keylist_push(&keys);
bch_btree_insert_node(b, op, &keys, NULL, NULL);
BUG_ON(!bch_keylist_empty(&keys));
btree_node_free(replace);
rw_unlock(true, n);
/* Invalidated our iterator */
return -EINTR;
}
static unsigned int btree_gc_count_keys(struct btree *b)
{
struct bkey *k;
struct btree_iter iter;
unsigned int ret = 0;
for_each_key_filter(&b->keys, k, &iter, bch_ptr_bad)
ret += bkey_u64s(k);
return ret;
}
static size_t btree_gc_min_nodes(struct cache_set *c)
{
size_t min_nodes;
/*
* Since incremental GC would stop 100ms when front
* side I/O comes, so when there are many btree nodes,
* if GC only processes constant (100) nodes each time,
* GC would last a long time, and the front side I/Os
* would run out of the buckets (since no new bucket
* can be allocated during GC), and be blocked again.
* So GC should not process constant nodes, but varied
* nodes according to the number of btree nodes, which
* realized by dividing GC into constant(100) times,
* so when there are many btree nodes, GC can process
* more nodes each time, otherwise, GC will process less
* nodes each time (but no less than MIN_GC_NODES)
*/
min_nodes = c->gc_stats.nodes / MAX_GC_TIMES;
if (min_nodes < MIN_GC_NODES)
min_nodes = MIN_GC_NODES;
return min_nodes;
}
static int btree_gc_recurse(struct btree *b, struct btree_op *op,
struct closure *writes, struct gc_stat *gc)
{
int ret = 0;
bool should_rewrite;
struct bkey *k;
struct btree_iter iter;
struct gc_merge_info r[GC_MERGE_NODES];
struct gc_merge_info *i, *last = r + ARRAY_SIZE(r) - 1;
bch_btree_iter_init(&b->keys, &iter, &b->c->gc_done);
for (i = r; i < r + ARRAY_SIZE(r); i++)
i->b = ERR_PTR(-EINTR);
while (1) {
k = bch_btree_iter_next_filter(&iter, &b->keys, bch_ptr_bad);
if (k) {
r->b = bch_btree_node_get(b->c, op, k, b->level - 1,
true, b);
if (IS_ERR(r->b)) {
ret = PTR_ERR(r->b);
break;
}
r->keys = btree_gc_count_keys(r->b);
ret = btree_gc_coalesce(b, op, gc, r);
if (ret)
break;
}
if (!last->b)
break;
if (!IS_ERR(last->b)) {
should_rewrite = btree_gc_mark_node(last->b, gc);
if (should_rewrite) {
ret = btree_gc_rewrite_node(b, op, last->b);
if (ret)
break;
}
if (last->b->level) {
ret = btree_gc_recurse(last->b, op, writes, gc);
if (ret)
break;
}
bkey_copy_key(&b->c->gc_done, &last->b->key);
/*
* Must flush leaf nodes before gc ends, since replace
* operations aren't journalled
*/
mutex_lock(&last->b->write_lock);
if (btree_node_dirty(last->b))
bch_btree_node_write(last->b, writes);
mutex_unlock(&last->b->write_lock);
rw_unlock(true, last->b);
}
memmove(r + 1, r, sizeof(r[0]) * (GC_MERGE_NODES - 1));
r->b = NULL;
if (atomic_read(&b->c->search_inflight) &&
gc->nodes >= gc->nodes_pre + btree_gc_min_nodes(b->c)) {
gc->nodes_pre = gc->nodes;
ret = -EAGAIN;
break;
}
if (need_resched()) {
ret = -EAGAIN;
break;
}
}
for (i = r; i < r + ARRAY_SIZE(r); i++)
if (!IS_ERR_OR_NULL(i->b)) {
mutex_lock(&i->b->write_lock);
if (btree_node_dirty(i->b))
bch_btree_node_write(i->b, writes);
mutex_unlock(&i->b->write_lock);
rw_unlock(true, i->b);
}
return ret;
}
static int bch_btree_gc_root(struct btree *b, struct btree_op *op,
struct closure *writes, struct gc_stat *gc)
{
struct btree *n = NULL;
int ret = 0;
bool should_rewrite;
should_rewrite = btree_gc_mark_node(b, gc);
if (should_rewrite) {
n = btree_node_alloc_replacement(b, NULL);
if (!IS_ERR(n)) {
bch_btree_node_write_sync(n);
bch_btree_set_root(n);
btree_node_free(b);
rw_unlock(true, n);
return -EINTR;
}
}
__bch_btree_mark_key(b->c, b->level + 1, &b->key);
if (b->level) {
ret = btree_gc_recurse(b, op, writes, gc);
if (ret)
return ret;
}
bkey_copy_key(&b->c->gc_done, &b->key);
return ret;
}
static void btree_gc_start(struct cache_set *c)
{
struct cache *ca;
struct bucket *b;
if (!c->gc_mark_valid)
return;
mutex_lock(&c->bucket_lock);
c->gc_mark_valid = 0;
c->gc_done = ZERO_KEY;
ca = c->cache;
for_each_bucket(b, ca) {
b->last_gc = b->gen;
if (!atomic_read(&b->pin)) {
SET_GC_MARK(b, 0);
SET_GC_SECTORS_USED(b, 0);
}
}
mutex_unlock(&c->bucket_lock);
}
static void bch_btree_gc_finish(struct cache_set *c)
{
struct bucket *b;
struct cache *ca;
unsigned int i, j;
uint64_t *k;
mutex_lock(&c->bucket_lock);
set_gc_sectors(c);
c->gc_mark_valid = 1;
c->need_gc = 0;
for (i = 0; i < KEY_PTRS(&c->uuid_bucket); i++)
SET_GC_MARK(PTR_BUCKET(c, &c->uuid_bucket, i),
GC_MARK_METADATA);
/* don't reclaim buckets to which writeback keys point */
rcu_read_lock();
for (i = 0; i < c->devices_max_used; i++) {
struct bcache_device *d = c->devices[i];
struct cached_dev *dc;
struct keybuf_key *w, *n;
if (!d || UUID_FLASH_ONLY(&c->uuids[i]))
continue;
dc = container_of(d, struct cached_dev, disk);
spin_lock(&dc->writeback_keys.lock);
rbtree_postorder_for_each_entry_safe(w, n,
&dc->writeback_keys.keys, node)
for (j = 0; j < KEY_PTRS(&w->key); j++)
SET_GC_MARK(PTR_BUCKET(c, &w->key, j),
GC_MARK_DIRTY);
spin_unlock(&dc->writeback_keys.lock);
}
rcu_read_unlock();
c->avail_nbuckets = 0;
ca = c->cache;
ca->invalidate_needs_gc = 0;
for (k = ca->sb.d; k < ca->sb.d + ca->sb.keys; k++)
SET_GC_MARK(ca->buckets + *k, GC_MARK_METADATA);
for (k = ca->prio_buckets;
k < ca->prio_buckets + prio_buckets(ca) * 2; k++)
SET_GC_MARK(ca->buckets + *k, GC_MARK_METADATA);
for_each_bucket(b, ca) {
c->need_gc = max(c->need_gc, bucket_gc_gen(b));
if (atomic_read(&b->pin))
continue;
BUG_ON(!GC_MARK(b) && GC_SECTORS_USED(b));
if (!GC_MARK(b) || GC_MARK(b) == GC_MARK_RECLAIMABLE)
c->avail_nbuckets++;
}
mutex_unlock(&c->bucket_lock);
}
static void bch_btree_gc(struct cache_set *c)
{
int ret;
struct gc_stat stats;
struct closure writes;
struct btree_op op;
uint64_t start_time = local_clock();
trace_bcache_gc_start(c);
memset(&stats, 0, sizeof(struct gc_stat));
closure_init_stack(&writes);
bch_btree_op_init(&op, SHRT_MAX);
btree_gc_start(c);
/* if CACHE_SET_IO_DISABLE set, gc thread should stop too */
do {
ret = bcache_btree_root(gc_root, c, &op, &writes, &stats);
closure_sync(&writes);
cond_resched();
if (ret == -EAGAIN)
schedule_timeout_interruptible(msecs_to_jiffies
(GC_SLEEP_MS));
else if (ret)
pr_warn("gc failed!\n");
} while (ret && !test_bit(CACHE_SET_IO_DISABLE, &c->flags));
bch_btree_gc_finish(c);
wake_up_allocators(c);
bch_time_stats_update(&c->btree_gc_time, start_time);
stats.key_bytes *= sizeof(uint64_t);
stats.data <<= 9;
bch_update_bucket_in_use(c, &stats);
memcpy(&c->gc_stats, &stats, sizeof(struct gc_stat));
trace_bcache_gc_end(c);
bch_moving_gc(c);
}
static bool gc_should_run(struct cache_set *c)
{
struct cache *ca = c->cache;
if (ca->invalidate_needs_gc)
return true;
if (atomic_read(&c->sectors_to_gc) < 0)
return true;
return false;
}
static int bch_gc_thread(void *arg)
{
struct cache_set *c = arg;
while (1) {
wait_event_interruptible(c->gc_wait,
kthread_should_stop() ||
test_bit(CACHE_SET_IO_DISABLE, &c->flags) ||
gc_should_run(c));
if (kthread_should_stop() ||
test_bit(CACHE_SET_IO_DISABLE, &c->flags))
break;
set_gc_sectors(c);
bch_btree_gc(c);
}
wait_for_kthread_stop();
return 0;
}
int bch_gc_thread_start(struct cache_set *c)
{
c->gc_thread = kthread_run(bch_gc_thread, c, "bcache_gc");
return PTR_ERR_OR_ZERO(c->gc_thread);
}
/* Initial partial gc */
static int bch_btree_check_recurse(struct btree *b, struct btree_op *op)
{
int ret = 0;
struct bkey *k, *p = NULL;
struct btree_iter iter;
for_each_key_filter(&b->keys, k, &iter, bch_ptr_invalid)
bch_initial_mark_key(b->c, b->level, k);
bch_initial_mark_key(b->c, b->level + 1, &b->key);
if (b->level) {
bch_btree_iter_init(&b->keys, &iter, NULL);
do {
k = bch_btree_iter_next_filter(&iter, &b->keys,
bch_ptr_bad);
if (k) {
btree_node_prefetch(b, k);
/*
* initiallize c->gc_stats.nodes
* for incremental GC
*/
b->c->gc_stats.nodes++;
}
if (p)
ret = bcache_btree(check_recurse, p, b, op);
p = k;
} while (p && !ret);
}
return ret;
}
static int bch_btree_check_thread(void *arg)
{
int ret;
struct btree_check_info *info = arg;
struct btree_check_state *check_state = info->state;
struct cache_set *c = check_state->c;
struct btree_iter iter;
struct bkey *k, *p;
int cur_idx, prev_idx, skip_nr;
k = p = NULL;
cur_idx = prev_idx = 0;
ret = 0;
/* root node keys are checked before thread created */
bch_btree_iter_init(&c->root->keys, &iter, NULL);
k = bch_btree_iter_next_filter(&iter, &c->root->keys, bch_ptr_bad);
BUG_ON(!k);
p = k;
while (k) {
/*
* Fetch a root node key index, skip the keys which
* should be fetched by other threads, then check the
* sub-tree indexed by the fetched key.
*/
spin_lock(&check_state->idx_lock);
cur_idx = check_state->key_idx;
check_state->key_idx++;
spin_unlock(&check_state->idx_lock);
skip_nr = cur_idx - prev_idx;
while (skip_nr) {
k = bch_btree_iter_next_filter(&iter,
&c->root->keys,
bch_ptr_bad);
if (k)
p = k;
else {
/*
* No more keys to check in root node,
* current checking threads are enough,
* stop creating more.
*/
atomic_set(&check_state->enough, 1);
/* Update check_state->enough earlier */
smp_mb__after_atomic();
goto out;
}
skip_nr--;
cond_resched();
}
if (p) {
struct btree_op op;
btree_node_prefetch(c->root, p);
c->gc_stats.nodes++;
bch_btree_op_init(&op, 0);
ret = bcache_btree(check_recurse, p, c->root, &op);
/*
* The op may be added to cache_set's btree_cache_wait
* in mca_cannibalize(), must ensure it is removed from
* the list and release btree_cache_alloc_lock before
* free op memory.
* Otherwise, the btree_cache_wait will be damaged.
*/
bch_cannibalize_unlock(c);
finish_wait(&c->btree_cache_wait, &(&op)->wait);
if (ret)
goto out;
}
p = NULL;
prev_idx = cur_idx;
cond_resched();
}
out:
info->result = ret;
/* update check_state->started among all CPUs */
smp_mb__before_atomic();
if (atomic_dec_and_test(&check_state->started))
wake_up(&check_state->wait);
return ret;
}
static int bch_btree_chkthread_nr(void)
{
int n = num_online_cpus()/2;
if (n == 0)
n = 1;
else if (n > BCH_BTR_CHKTHREAD_MAX)
n = BCH_BTR_CHKTHREAD_MAX;
return n;
}
int bch_btree_check(struct cache_set *c)
{
int ret = 0;
int i;
struct bkey *k = NULL;
struct btree_iter iter;
struct btree_check_state check_state;
/* check and mark root node keys */
for_each_key_filter(&c->root->keys, k, &iter, bch_ptr_invalid)
bch_initial_mark_key(c, c->root->level, k);
bch_initial_mark_key(c, c->root->level + 1, &c->root->key);
if (c->root->level == 0)
return 0;
memset(&check_state, 0, sizeof(struct btree_check_state));
check_state.c = c;
check_state.total_threads = bch_btree_chkthread_nr();
check_state.key_idx = 0;
spin_lock_init(&check_state.idx_lock);
atomic_set(&check_state.started, 0);
atomic_set(&check_state.enough, 0);
init_waitqueue_head(&check_state.wait);
rw_lock(0, c->root, c->root->level);
/*
* Run multiple threads to check btree nodes in parallel,
* if check_state.enough is non-zero, it means current
* running check threads are enough, unncessary to create
* more.
*/
for (i = 0; i < check_state.total_threads; i++) {
/* fetch latest check_state.enough earlier */
smp_mb__before_atomic();
if (atomic_read(&check_state.enough))
break;
check_state.infos[i].result = 0;
check_state.infos[i].state = &check_state;
check_state.infos[i].thread =
kthread_run(bch_btree_check_thread,
&check_state.infos[i],
"bch_btrchk[%d]", i);
if (IS_ERR(check_state.infos[i].thread)) {
pr_err("fails to run thread bch_btrchk[%d]\n", i);
for (--i; i >= 0; i--)
kthread_stop(check_state.infos[i].thread);
ret = -ENOMEM;
goto out;
}
atomic_inc(&check_state.started);
}
/*
* Must wait for all threads to stop.
*/
wait_event(check_state.wait, atomic_read(&check_state.started) == 0);
for (i = 0; i < check_state.total_threads; i++) {
if (check_state.infos[i].result) {
ret = check_state.infos[i].result;
goto out;
}
}
out:
rw_unlock(0, c->root);
return ret;
}
void bch_initial_gc_finish(struct cache_set *c)
{
struct cache *ca = c->cache;
struct bucket *b;
bch_btree_gc_finish(c);
mutex_lock(&c->bucket_lock);
/*
* We need to put some unused buckets directly on the prio freelist in
* order to get the allocator thread started - it needs freed buckets in
* order to rewrite the prios and gens, and it needs to rewrite prios
* and gens in order to free buckets.
*
* This is only safe for buckets that have no live data in them, which
* there should always be some of.
*/
for_each_bucket(b, ca) {
if (fifo_full(&ca->free[RESERVE_PRIO]) &&
fifo_full(&ca->free[RESERVE_BTREE]))
break;
if (bch_can_invalidate_bucket(ca, b) &&
!GC_MARK(b)) {
__bch_invalidate_one_bucket(ca, b);
if (!fifo_push(&ca->free[RESERVE_PRIO],
b - ca->buckets))
fifo_push(&ca->free[RESERVE_BTREE],
b - ca->buckets);
}
}
mutex_unlock(&c->bucket_lock);
}
/* Btree insertion */
static bool btree_insert_key(struct btree *b, struct bkey *k,
struct bkey *replace_key)
{
unsigned int status;
BUG_ON(bkey_cmp(k, &b->key) > 0);
status = bch_btree_insert_key(&b->keys, k, replace_key);
if (status != BTREE_INSERT_STATUS_NO_INSERT) {
bch_check_keys(&b->keys, "%u for %s", status,
replace_key ? "replace" : "insert");
trace_bcache_btree_insert_key(b, k, replace_key != NULL,
status);
return true;
} else
return false;
}
static size_t insert_u64s_remaining(struct btree *b)
{
long ret = bch_btree_keys_u64s_remaining(&b->keys);
/*
* Might land in the middle of an existing extent and have to split it
*/
if (b->keys.ops->is_extents)
ret -= KEY_MAX_U64S;
return max(ret, 0L);
}
static bool bch_btree_insert_keys(struct btree *b, struct btree_op *op,
struct keylist *insert_keys,
struct bkey *replace_key)
{
bool ret = false;
int oldsize = bch_count_data(&b->keys);
while (!bch_keylist_empty(insert_keys)) {
struct bkey *k = insert_keys->keys;
if (bkey_u64s(k) > insert_u64s_remaining(b))
break;
if (bkey_cmp(k, &b->key) <= 0) {
if (!b->level)
bkey_put(b->c, k);
ret |= btree_insert_key(b, k, replace_key);
bch_keylist_pop_front(insert_keys);
} else if (bkey_cmp(&START_KEY(k), &b->key) < 0) {
BKEY_PADDED(key) temp;
bkey_copy(&temp.key, insert_keys->keys);
bch_cut_back(&b->key, &temp.key);
bch_cut_front(&b->key, insert_keys->keys);
ret |= btree_insert_key(b, &temp.key, replace_key);
break;
} else {
break;
}
}
if (!ret)
op->insert_collision = true;
BUG_ON(!bch_keylist_empty(insert_keys) && b->level);
BUG_ON(bch_count_data(&b->keys) < oldsize);
return ret;
}
static int btree_split(struct btree *b, struct btree_op *op,
struct keylist *insert_keys,
struct bkey *replace_key)
{
bool split;
struct btree *n1, *n2 = NULL, *n3 = NULL;
uint64_t start_time = local_clock();
struct closure cl;
struct keylist parent_keys;
closure_init_stack(&cl);
bch_keylist_init(&parent_keys);
if (btree_check_reserve(b, op)) {
if (!b->level)
return -EINTR;
else
WARN(1, "insufficient reserve for split\n");
}
n1 = btree_node_alloc_replacement(b, op);
if (IS_ERR(n1))
goto err;
split = set_blocks(btree_bset_first(n1),
block_bytes(n1->c->cache)) > (btree_blocks(b) * 4) / 5;
if (split) {
unsigned int keys = 0;
trace_bcache_btree_node_split(b, btree_bset_first(n1)->keys);
n2 = bch_btree_node_alloc(b->c, op, b->level, b->parent);
if (IS_ERR(n2))
goto err_free1;
if (!b->parent) {
n3 = bch_btree_node_alloc(b->c, op, b->level + 1, NULL);
if (IS_ERR(n3))
goto err_free2;
}
mutex_lock(&n1->write_lock);
mutex_lock(&n2->write_lock);
bch_btree_insert_keys(n1, op, insert_keys, replace_key);
/*
* Has to be a linear search because we don't have an auxiliary
* search tree yet
*/
while (keys < (btree_bset_first(n1)->keys * 3) / 5)
keys += bkey_u64s(bset_bkey_idx(btree_bset_first(n1),
keys));
bkey_copy_key(&n1->key,
bset_bkey_idx(btree_bset_first(n1), keys));
keys += bkey_u64s(bset_bkey_idx(btree_bset_first(n1), keys));
btree_bset_first(n2)->keys = btree_bset_first(n1)->keys - keys;
btree_bset_first(n1)->keys = keys;
memcpy(btree_bset_first(n2)->start,
bset_bkey_last(btree_bset_first(n1)),
btree_bset_first(n2)->keys * sizeof(uint64_t));
bkey_copy_key(&n2->key, &b->key);
bch_keylist_add(&parent_keys, &n2->key);
bch_btree_node_write(n2, &cl);
mutex_unlock(&n2->write_lock);
rw_unlock(true, n2);
} else {
trace_bcache_btree_node_compact(b, btree_bset_first(n1)->keys);
mutex_lock(&n1->write_lock);
bch_btree_insert_keys(n1, op, insert_keys, replace_key);
}
bch_keylist_add(&parent_keys, &n1->key);
bch_btree_node_write(n1, &cl);
mutex_unlock(&n1->write_lock);
if (n3) {
/* Depth increases, make a new root */
mutex_lock(&n3->write_lock);
bkey_copy_key(&n3->key, &MAX_KEY);
bch_btree_insert_keys(n3, op, &parent_keys, NULL);
bch_btree_node_write(n3, &cl);
mutex_unlock(&n3->write_lock);
closure_sync(&cl);
bch_btree_set_root(n3);
rw_unlock(true, n3);
} else if (!b->parent) {
/* Root filled up but didn't need to be split */
closure_sync(&cl);
bch_btree_set_root(n1);
} else {
/* Split a non root node */
closure_sync(&cl);
make_btree_freeing_key(b, parent_keys.top);
bch_keylist_push(&parent_keys);
bch_btree_insert_node(b->parent, op, &parent_keys, NULL, NULL);
BUG_ON(!bch_keylist_empty(&parent_keys));
}
btree_node_free(b);
rw_unlock(true, n1);
bch_time_stats_update(&b->c->btree_split_time, start_time);
return 0;
err_free2:
bkey_put(b->c, &n2->key);
btree_node_free(n2);
rw_unlock(true, n2);
err_free1:
bkey_put(b->c, &n1->key);
btree_node_free(n1);
rw_unlock(true, n1);
err:
WARN(1, "bcache: btree split failed (level %u)", b->level);
if (n3 == ERR_PTR(-EAGAIN) ||
n2 == ERR_PTR(-EAGAIN) ||
n1 == ERR_PTR(-EAGAIN))
return -EAGAIN;
return -ENOMEM;
}
static int bch_btree_insert_node(struct btree *b, struct btree_op *op,
struct keylist *insert_keys,
atomic_t *journal_ref,
struct bkey *replace_key)
{
struct closure cl;
BUG_ON(b->level && replace_key);
closure_init_stack(&cl);
mutex_lock(&b->write_lock);
if (write_block(b) != btree_bset_last(b) &&
b->keys.last_set_unwritten)
bch_btree_init_next(b); /* just wrote a set */
if (bch_keylist_nkeys(insert_keys) > insert_u64s_remaining(b)) {
mutex_unlock(&b->write_lock);
goto split;
}
BUG_ON(write_block(b) != btree_bset_last(b));
if (bch_btree_insert_keys(b, op, insert_keys, replace_key)) {
if (!b->level)
bch_btree_leaf_dirty(b, journal_ref);
else
bch_btree_node_write(b, &cl);
}
mutex_unlock(&b->write_lock);
/* wait for btree node write if necessary, after unlock */
closure_sync(&cl);
return 0;
split:
if (current->bio_list) {
op->lock = b->c->root->level + 1;
return -EAGAIN;
} else if (op->lock <= b->c->root->level) {
op->lock = b->c->root->level + 1;
return -EINTR;
} else {
/* Invalidated all iterators */
int ret = btree_split(b, op, insert_keys, replace_key);
if (bch_keylist_empty(insert_keys))
return 0;
else if (!ret)
return -EINTR;
return ret;
}
}
int bch_btree_insert_check_key(struct btree *b, struct btree_op *op,
struct bkey *check_key)
{
int ret = -EINTR;
uint64_t btree_ptr = b->key.ptr[0];
unsigned long seq = b->seq;
struct keylist insert;
bool upgrade = op->lock == -1;
bch_keylist_init(&insert);
if (upgrade) {
rw_unlock(false, b);
rw_lock(true, b, b->level);
if (b->key.ptr[0] != btree_ptr ||
b->seq != seq + 1) {
op->lock = b->level;
goto out;
}
}
SET_KEY_PTRS(check_key, 1);
get_random_bytes(&check_key->ptr[0], sizeof(uint64_t));
SET_PTR_DEV(check_key, 0, PTR_CHECK_DEV);
bch_keylist_add(&insert, check_key);
ret = bch_btree_insert_node(b, op, &insert, NULL, NULL);
BUG_ON(!ret && !bch_keylist_empty(&insert));
out:
if (upgrade)
downgrade_write(&b->lock);
return ret;
}
struct btree_insert_op {
struct btree_op op;
struct keylist *keys;
atomic_t *journal_ref;
struct bkey *replace_key;
};
static int btree_insert_fn(struct btree_op *b_op, struct btree *b)
{
struct btree_insert_op *op = container_of(b_op,
struct btree_insert_op, op);
int ret = bch_btree_insert_node(b, &op->op, op->keys,
op->journal_ref, op->replace_key);
if (ret && !bch_keylist_empty(op->keys))
return ret;
else
return MAP_DONE;
}
int bch_btree_insert(struct cache_set *c, struct keylist *keys,
atomic_t *journal_ref, struct bkey *replace_key)
{
struct btree_insert_op op;
int ret = 0;
BUG_ON(current->bio_list);
BUG_ON(bch_keylist_empty(keys));
bch_btree_op_init(&op.op, 0);
op.keys = keys;
op.journal_ref = journal_ref;
op.replace_key = replace_key;
while (!ret && !bch_keylist_empty(keys)) {
op.op.lock = 0;
ret = bch_btree_map_leaf_nodes(&op.op, c,
&START_KEY(keys->keys),
btree_insert_fn);
}
if (ret) {
struct bkey *k;
pr_err("error %i\n", ret);
while ((k = bch_keylist_pop(keys)))
bkey_put(c, k);
} else if (op.op.insert_collision)
ret = -ESRCH;
return ret;
}
void bch_btree_set_root(struct btree *b)
{
unsigned int i;
struct closure cl;
closure_init_stack(&cl);
trace_bcache_btree_set_root(b);
BUG_ON(!b->written);
for (i = 0; i < KEY_PTRS(&b->key); i++)
BUG_ON(PTR_BUCKET(b->c, &b->key, i)->prio != BTREE_PRIO);
mutex_lock(&b->c->bucket_lock);
list_del_init(&b->list);
mutex_unlock(&b->c->bucket_lock);
b->c->root = b;
bch_journal_meta(b->c, &cl);
closure_sync(&cl);
}
/* Map across nodes or keys */
static int bch_btree_map_nodes_recurse(struct btree *b, struct btree_op *op,
struct bkey *from,
btree_map_nodes_fn *fn, int flags)
{
int ret = MAP_CONTINUE;
if (b->level) {
struct bkey *k;
struct btree_iter iter;
bch_btree_iter_init(&b->keys, &iter, from);
while ((k = bch_btree_iter_next_filter(&iter, &b->keys,
bch_ptr_bad))) {
ret = bcache_btree(map_nodes_recurse, k, b,
op, from, fn, flags);
from = NULL;
if (ret != MAP_CONTINUE)
return ret;
}
}
if (!b->level || flags == MAP_ALL_NODES)
ret = fn(op, b);
return ret;
}
int __bch_btree_map_nodes(struct btree_op *op, struct cache_set *c,
struct bkey *from, btree_map_nodes_fn *fn, int flags)
{
return bcache_btree_root(map_nodes_recurse, c, op, from, fn, flags);
}
int bch_btree_map_keys_recurse(struct btree *b, struct btree_op *op,
struct bkey *from, btree_map_keys_fn *fn,
int flags)
{
int ret = MAP_CONTINUE;
struct bkey *k;
struct btree_iter iter;
bch_btree_iter_init(&b->keys, &iter, from);
while ((k = bch_btree_iter_next_filter(&iter, &b->keys, bch_ptr_bad))) {
ret = !b->level
? fn(op, b, k)
: bcache_btree(map_keys_recurse, k,
b, op, from, fn, flags);
from = NULL;
if (ret != MAP_CONTINUE)
return ret;
}
if (!b->level && (flags & MAP_END_KEY))
ret = fn(op, b, &KEY(KEY_INODE(&b->key),
KEY_OFFSET(&b->key), 0));
return ret;
}
int bch_btree_map_keys(struct btree_op *op, struct cache_set *c,
struct bkey *from, btree_map_keys_fn *fn, int flags)
{
return bcache_btree_root(map_keys_recurse, c, op, from, fn, flags);
}
/* Keybuf code */
static inline int keybuf_cmp(struct keybuf_key *l, struct keybuf_key *r)
{
/* Overlapping keys compare equal */
if (bkey_cmp(&l->key, &START_KEY(&r->key)) <= 0)
return -1;
if (bkey_cmp(&START_KEY(&l->key), &r->key) >= 0)
return 1;
return 0;
}
static inline int keybuf_nonoverlapping_cmp(struct keybuf_key *l,
struct keybuf_key *r)
{
return clamp_t(int64_t, bkey_cmp(&l->key, &r->key), -1, 1);
}
struct refill {
struct btree_op op;
unsigned int nr_found;
struct keybuf *buf;
struct bkey *end;
keybuf_pred_fn *pred;
};
static int refill_keybuf_fn(struct btree_op *op, struct btree *b,
struct bkey *k)
{
struct refill *refill = container_of(op, struct refill, op);
struct keybuf *buf = refill->buf;
int ret = MAP_CONTINUE;
if (bkey_cmp(k, refill->end) > 0) {
ret = MAP_DONE;
goto out;
}
if (!KEY_SIZE(k)) /* end key */
goto out;
if (refill->pred(buf, k)) {
struct keybuf_key *w;
spin_lock(&buf->lock);
w = array_alloc(&buf->freelist);
if (!w) {
spin_unlock(&buf->lock);
return MAP_DONE;
}
w->private = NULL;
bkey_copy(&w->key, k);
if (RB_INSERT(&buf->keys, w, node, keybuf_cmp))
array_free(&buf->freelist, w);
else
refill->nr_found++;
if (array_freelist_empty(&buf->freelist))
ret = MAP_DONE;
spin_unlock(&buf->lock);
}
out:
buf->last_scanned = *k;
return ret;
}
void bch_refill_keybuf(struct cache_set *c, struct keybuf *buf,
struct bkey *end, keybuf_pred_fn *pred)
{
struct bkey start = buf->last_scanned;
struct refill refill;
cond_resched();
bch_btree_op_init(&refill.op, -1);
refill.nr_found = 0;
refill.buf = buf;
refill.end = end;
refill.pred = pred;
bch_btree_map_keys(&refill.op, c, &buf->last_scanned,
refill_keybuf_fn, MAP_END_KEY);
trace_bcache_keyscan(refill.nr_found,
KEY_INODE(&start), KEY_OFFSET(&start),
KEY_INODE(&buf->last_scanned),
KEY_OFFSET(&buf->last_scanned));
spin_lock(&buf->lock);
if (!RB_EMPTY_ROOT(&buf->keys)) {
struct keybuf_key *w;
w = RB_FIRST(&buf->keys, struct keybuf_key, node);
buf->start = START_KEY(&w->key);
w = RB_LAST(&buf->keys, struct keybuf_key, node);
buf->end = w->key;
} else {
buf->start = MAX_KEY;
buf->end = MAX_KEY;
}
spin_unlock(&buf->lock);
}
static void __bch_keybuf_del(struct keybuf *buf, struct keybuf_key *w)
{
rb_erase(&w->node, &buf->keys);
array_free(&buf->freelist, w);
}
void bch_keybuf_del(struct keybuf *buf, struct keybuf_key *w)
{
spin_lock(&buf->lock);
__bch_keybuf_del(buf, w);
spin_unlock(&buf->lock);
}
bool bch_keybuf_check_overlapping(struct keybuf *buf, struct bkey *start,
struct bkey *end)
{
bool ret = false;
struct keybuf_key *p, *w, s;
s.key = *start;
if (bkey_cmp(end, &buf->start) <= 0 ||
bkey_cmp(start, &buf->end) >= 0)
return false;
spin_lock(&buf->lock);
w = RB_GREATER(&buf->keys, s, node, keybuf_nonoverlapping_cmp);
while (w && bkey_cmp(&START_KEY(&w->key), end) < 0) {
p = w;
w = RB_NEXT(w, node);
if (p->private)
ret = true;
else
__bch_keybuf_del(buf, p);
}
spin_unlock(&buf->lock);
return ret;
}
struct keybuf_key *bch_keybuf_next(struct keybuf *buf)
{
struct keybuf_key *w;
spin_lock(&buf->lock);
w = RB_FIRST(&buf->keys, struct keybuf_key, node);
while (w && w->private)
w = RB_NEXT(w, node);
if (w)
w->private = ERR_PTR(-EINTR);
spin_unlock(&buf->lock);
return w;
}
struct keybuf_key *bch_keybuf_next_rescan(struct cache_set *c,
struct keybuf *buf,
struct bkey *end,
keybuf_pred_fn *pred)
{
struct keybuf_key *ret;
while (1) {
ret = bch_keybuf_next(buf);
if (ret)
break;
if (bkey_cmp(&buf->last_scanned, end) >= 0) {
pr_debug("scan finished\n");
break;
}
bch_refill_keybuf(c, buf, end, pred);
}
return ret;
}
void bch_keybuf_init(struct keybuf *buf)
{
buf->last_scanned = MAX_KEY;
buf->keys = RB_ROOT;
spin_lock_init(&buf->lock);
array_allocator_init(&buf->freelist);
}
void bch_btree_exit(void)
{
if (btree_io_wq)
destroy_workqueue(btree_io_wq);
}
int __init bch_btree_init(void)
{
btree_io_wq = alloc_workqueue("bch_btree_io", WQ_MEM_RECLAIM, 0);
if (!btree_io_wq)
return -ENOMEM;
return 0;
}
| linux-master | drivers/md/bcache/btree.c |
// SPDX-License-Identifier: GPL-2.0
#include "bcache.h"
#include "btree.h"
#include <linux/blktrace_api.h>
#include <linux/module.h>
#define CREATE_TRACE_POINTS
#include <trace/events/bcache.h>
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_request_start);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_request_end);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_bypass_sequential);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_bypass_congested);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_read);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_write);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_read_retry);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_cache_insert);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_journal_replay_key);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_journal_write);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_journal_full);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_journal_entry_full);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_btree_cache_cannibalize);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_btree_read);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_btree_write);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_btree_node_alloc);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_btree_node_alloc_fail);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_btree_node_free);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_btree_gc_coalesce);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_gc_start);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_gc_end);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_gc_copy);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_gc_copy_collision);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_btree_insert_key);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_btree_node_split);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_btree_node_compact);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_btree_set_root);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_invalidate);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_alloc_fail);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_writeback);
EXPORT_TRACEPOINT_SYMBOL_GPL(bcache_writeback_collision);
| linux-master | drivers/md/bcache/trace.c |
// SPDX-License-Identifier: GPL-2.0
/*
* Main bcache entry point - handle a read or a write request and decide what to
* do with it; the make_request functions are called by the block layer.
*
* Copyright 2010, 2011 Kent Overstreet <[email protected]>
* Copyright 2012 Google, Inc.
*/
#include "bcache.h"
#include "btree.h"
#include "debug.h"
#include "request.h"
#include "writeback.h"
#include <linux/module.h>
#include <linux/hash.h>
#include <linux/random.h>
#include <linux/backing-dev.h>
#include <trace/events/bcache.h>
#define CUTOFF_CACHE_ADD 95
#define CUTOFF_CACHE_READA 90
struct kmem_cache *bch_search_cache;
static void bch_data_insert_start(struct closure *cl);
static unsigned int cache_mode(struct cached_dev *dc)
{
return BDEV_CACHE_MODE(&dc->sb);
}
static bool verify(struct cached_dev *dc)
{
return dc->verify;
}
static void bio_csum(struct bio *bio, struct bkey *k)
{
struct bio_vec bv;
struct bvec_iter iter;
uint64_t csum = 0;
bio_for_each_segment(bv, bio, iter) {
void *d = bvec_kmap_local(&bv);
csum = crc64_be(csum, d, bv.bv_len);
kunmap_local(d);
}
k->ptr[KEY_PTRS(k)] = csum & (~0ULL >> 1);
}
/* Insert data into cache */
static void bch_data_insert_keys(struct closure *cl)
{
struct data_insert_op *op = container_of(cl, struct data_insert_op, cl);
atomic_t *journal_ref = NULL;
struct bkey *replace_key = op->replace ? &op->replace_key : NULL;
int ret;
if (!op->replace)
journal_ref = bch_journal(op->c, &op->insert_keys,
op->flush_journal ? cl : NULL);
ret = bch_btree_insert(op->c, &op->insert_keys,
journal_ref, replace_key);
if (ret == -ESRCH) {
op->replace_collision = true;
} else if (ret) {
op->status = BLK_STS_RESOURCE;
op->insert_data_done = true;
}
if (journal_ref)
atomic_dec_bug(journal_ref);
if (!op->insert_data_done) {
continue_at(cl, bch_data_insert_start, op->wq);
return;
}
bch_keylist_free(&op->insert_keys);
closure_return(cl);
}
static int bch_keylist_realloc(struct keylist *l, unsigned int u64s,
struct cache_set *c)
{
size_t oldsize = bch_keylist_nkeys(l);
size_t newsize = oldsize + u64s;
/*
* The journalling code doesn't handle the case where the keys to insert
* is bigger than an empty write: If we just return -ENOMEM here,
* bch_data_insert_keys() will insert the keys created so far
* and finish the rest when the keylist is empty.
*/
if (newsize * sizeof(uint64_t) > block_bytes(c->cache) - sizeof(struct jset))
return -ENOMEM;
return __bch_keylist_realloc(l, u64s);
}
static void bch_data_invalidate(struct closure *cl)
{
struct data_insert_op *op = container_of(cl, struct data_insert_op, cl);
struct bio *bio = op->bio;
pr_debug("invalidating %i sectors from %llu\n",
bio_sectors(bio), (uint64_t) bio->bi_iter.bi_sector);
while (bio_sectors(bio)) {
unsigned int sectors = min(bio_sectors(bio),
1U << (KEY_SIZE_BITS - 1));
if (bch_keylist_realloc(&op->insert_keys, 2, op->c))
goto out;
bio->bi_iter.bi_sector += sectors;
bio->bi_iter.bi_size -= sectors << 9;
bch_keylist_add(&op->insert_keys,
&KEY(op->inode,
bio->bi_iter.bi_sector,
sectors));
}
op->insert_data_done = true;
/* get in bch_data_insert() */
bio_put(bio);
out:
continue_at(cl, bch_data_insert_keys, op->wq);
}
static void bch_data_insert_error(struct closure *cl)
{
struct data_insert_op *op = container_of(cl, struct data_insert_op, cl);
/*
* Our data write just errored, which means we've got a bunch of keys to
* insert that point to data that wasn't successfully written.
*
* We don't have to insert those keys but we still have to invalidate
* that region of the cache - so, if we just strip off all the pointers
* from the keys we'll accomplish just that.
*/
struct bkey *src = op->insert_keys.keys, *dst = op->insert_keys.keys;
while (src != op->insert_keys.top) {
struct bkey *n = bkey_next(src);
SET_KEY_PTRS(src, 0);
memmove(dst, src, bkey_bytes(src));
dst = bkey_next(dst);
src = n;
}
op->insert_keys.top = dst;
bch_data_insert_keys(cl);
}
static void bch_data_insert_endio(struct bio *bio)
{
struct closure *cl = bio->bi_private;
struct data_insert_op *op = container_of(cl, struct data_insert_op, cl);
if (bio->bi_status) {
/* TODO: We could try to recover from this. */
if (op->writeback)
op->status = bio->bi_status;
else if (!op->replace)
set_closure_fn(cl, bch_data_insert_error, op->wq);
else
set_closure_fn(cl, NULL, NULL);
}
bch_bbio_endio(op->c, bio, bio->bi_status, "writing data to cache");
}
static void bch_data_insert_start(struct closure *cl)
{
struct data_insert_op *op = container_of(cl, struct data_insert_op, cl);
struct bio *bio = op->bio, *n;
if (op->bypass)
return bch_data_invalidate(cl);
if (atomic_sub_return(bio_sectors(bio), &op->c->sectors_to_gc) < 0)
wake_up_gc(op->c);
/*
* Journal writes are marked REQ_PREFLUSH; if the original write was a
* flush, it'll wait on the journal write.
*/
bio->bi_opf &= ~(REQ_PREFLUSH|REQ_FUA);
do {
unsigned int i;
struct bkey *k;
struct bio_set *split = &op->c->bio_split;
/* 1 for the device pointer and 1 for the chksum */
if (bch_keylist_realloc(&op->insert_keys,
3 + (op->csum ? 1 : 0),
op->c)) {
continue_at(cl, bch_data_insert_keys, op->wq);
return;
}
k = op->insert_keys.top;
bkey_init(k);
SET_KEY_INODE(k, op->inode);
SET_KEY_OFFSET(k, bio->bi_iter.bi_sector);
if (!bch_alloc_sectors(op->c, k, bio_sectors(bio),
op->write_point, op->write_prio,
op->writeback))
goto err;
n = bio_next_split(bio, KEY_SIZE(k), GFP_NOIO, split);
n->bi_end_io = bch_data_insert_endio;
n->bi_private = cl;
if (op->writeback) {
SET_KEY_DIRTY(k, true);
for (i = 0; i < KEY_PTRS(k); i++)
SET_GC_MARK(PTR_BUCKET(op->c, k, i),
GC_MARK_DIRTY);
}
SET_KEY_CSUM(k, op->csum);
if (KEY_CSUM(k))
bio_csum(n, k);
trace_bcache_cache_insert(k);
bch_keylist_push(&op->insert_keys);
n->bi_opf = REQ_OP_WRITE;
bch_submit_bbio(n, op->c, k, 0);
} while (n != bio);
op->insert_data_done = true;
continue_at(cl, bch_data_insert_keys, op->wq);
return;
err:
/* bch_alloc_sectors() blocks if s->writeback = true */
BUG_ON(op->writeback);
/*
* But if it's not a writeback write we'd rather just bail out if
* there aren't any buckets ready to write to - it might take awhile and
* we might be starving btree writes for gc or something.
*/
if (!op->replace) {
/*
* Writethrough write: We can't complete the write until we've
* updated the index. But we don't want to delay the write while
* we wait for buckets to be freed up, so just invalidate the
* rest of the write.
*/
op->bypass = true;
return bch_data_invalidate(cl);
} else {
/*
* From a cache miss, we can just insert the keys for the data
* we have written or bail out if we didn't do anything.
*/
op->insert_data_done = true;
bio_put(bio);
if (!bch_keylist_empty(&op->insert_keys))
continue_at(cl, bch_data_insert_keys, op->wq);
else
closure_return(cl);
}
}
/**
* bch_data_insert - stick some data in the cache
* @cl: closure pointer.
*
* This is the starting point for any data to end up in a cache device; it could
* be from a normal write, or a writeback write, or a write to a flash only
* volume - it's also used by the moving garbage collector to compact data in
* mostly empty buckets.
*
* It first writes the data to the cache, creating a list of keys to be inserted
* (if the data had to be fragmented there will be multiple keys); after the
* data is written it calls bch_journal, and after the keys have been added to
* the next journal write they're inserted into the btree.
*
* It inserts the data in op->bio; bi_sector is used for the key offset,
* and op->inode is used for the key inode.
*
* If op->bypass is true, instead of inserting the data it invalidates the
* region of the cache represented by op->bio and op->inode.
*/
void bch_data_insert(struct closure *cl)
{
struct data_insert_op *op = container_of(cl, struct data_insert_op, cl);
trace_bcache_write(op->c, op->inode, op->bio,
op->writeback, op->bypass);
bch_keylist_init(&op->insert_keys);
bio_get(op->bio);
bch_data_insert_start(cl);
}
/*
* Congested? Return 0 (not congested) or the limit (in sectors)
* beyond which we should bypass the cache due to congestion.
*/
unsigned int bch_get_congested(const struct cache_set *c)
{
int i;
if (!c->congested_read_threshold_us &&
!c->congested_write_threshold_us)
return 0;
i = (local_clock_us() - c->congested_last_us) / 1024;
if (i < 0)
return 0;
i += atomic_read(&c->congested);
if (i >= 0)
return 0;
i += CONGESTED_MAX;
if (i > 0)
i = fract_exp_two(i, 6);
i -= hweight32(get_random_u32());
return i > 0 ? i : 1;
}
static void add_sequential(struct task_struct *t)
{
ewma_add(t->sequential_io_avg,
t->sequential_io, 8, 0);
t->sequential_io = 0;
}
static struct hlist_head *iohash(struct cached_dev *dc, uint64_t k)
{
return &dc->io_hash[hash_64(k, RECENT_IO_BITS)];
}
static bool check_should_bypass(struct cached_dev *dc, struct bio *bio)
{
struct cache_set *c = dc->disk.c;
unsigned int mode = cache_mode(dc);
unsigned int sectors, congested;
struct task_struct *task = current;
struct io *i;
if (test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags) ||
c->gc_stats.in_use > CUTOFF_CACHE_ADD ||
(bio_op(bio) == REQ_OP_DISCARD))
goto skip;
if (mode == CACHE_MODE_NONE ||
(mode == CACHE_MODE_WRITEAROUND &&
op_is_write(bio_op(bio))))
goto skip;
/*
* If the bio is for read-ahead or background IO, bypass it or
* not depends on the following situations,
* - If the IO is for meta data, always cache it and no bypass
* - If the IO is not meta data, check dc->cache_reada_policy,
* BCH_CACHE_READA_ALL: cache it and not bypass
* BCH_CACHE_READA_META_ONLY: not cache it and bypass
* That is, read-ahead request for metadata always get cached
* (eg, for gfs2 or xfs).
*/
if ((bio->bi_opf & (REQ_RAHEAD|REQ_BACKGROUND))) {
if (!(bio->bi_opf & (REQ_META|REQ_PRIO)) &&
(dc->cache_readahead_policy != BCH_CACHE_READA_ALL))
goto skip;
}
if (bio->bi_iter.bi_sector & (c->cache->sb.block_size - 1) ||
bio_sectors(bio) & (c->cache->sb.block_size - 1)) {
pr_debug("skipping unaligned io\n");
goto skip;
}
if (bypass_torture_test(dc)) {
if (get_random_u32_below(4) == 3)
goto skip;
else
goto rescale;
}
congested = bch_get_congested(c);
if (!congested && !dc->sequential_cutoff)
goto rescale;
spin_lock(&dc->io_lock);
hlist_for_each_entry(i, iohash(dc, bio->bi_iter.bi_sector), hash)
if (i->last == bio->bi_iter.bi_sector &&
time_before(jiffies, i->jiffies))
goto found;
i = list_first_entry(&dc->io_lru, struct io, lru);
add_sequential(task);
i->sequential = 0;
found:
if (i->sequential + bio->bi_iter.bi_size > i->sequential)
i->sequential += bio->bi_iter.bi_size;
i->last = bio_end_sector(bio);
i->jiffies = jiffies + msecs_to_jiffies(5000);
task->sequential_io = i->sequential;
hlist_del(&i->hash);
hlist_add_head(&i->hash, iohash(dc, i->last));
list_move_tail(&i->lru, &dc->io_lru);
spin_unlock(&dc->io_lock);
sectors = max(task->sequential_io,
task->sequential_io_avg) >> 9;
if (dc->sequential_cutoff &&
sectors >= dc->sequential_cutoff >> 9) {
trace_bcache_bypass_sequential(bio);
goto skip;
}
if (congested && sectors >= congested) {
trace_bcache_bypass_congested(bio);
goto skip;
}
rescale:
bch_rescale_priorities(c, bio_sectors(bio));
return false;
skip:
bch_mark_sectors_bypassed(c, dc, bio_sectors(bio));
return true;
}
/* Cache lookup */
struct search {
/* Stack frame for bio_complete */
struct closure cl;
struct bbio bio;
struct bio *orig_bio;
struct bio *cache_miss;
struct bcache_device *d;
unsigned int insert_bio_sectors;
unsigned int recoverable:1;
unsigned int write:1;
unsigned int read_dirty_data:1;
unsigned int cache_missed:1;
struct block_device *orig_bdev;
unsigned long start_time;
struct btree_op op;
struct data_insert_op iop;
};
static void bch_cache_read_endio(struct bio *bio)
{
struct bbio *b = container_of(bio, struct bbio, bio);
struct closure *cl = bio->bi_private;
struct search *s = container_of(cl, struct search, cl);
/*
* If the bucket was reused while our bio was in flight, we might have
* read the wrong data. Set s->error but not error so it doesn't get
* counted against the cache device, but we'll still reread the data
* from the backing device.
*/
if (bio->bi_status)
s->iop.status = bio->bi_status;
else if (!KEY_DIRTY(&b->key) &&
ptr_stale(s->iop.c, &b->key, 0)) {
atomic_long_inc(&s->iop.c->cache_read_races);
s->iop.status = BLK_STS_IOERR;
}
bch_bbio_endio(s->iop.c, bio, bio->bi_status, "reading from cache");
}
/*
* Read from a single key, handling the initial cache miss if the key starts in
* the middle of the bio
*/
static int cache_lookup_fn(struct btree_op *op, struct btree *b, struct bkey *k)
{
struct search *s = container_of(op, struct search, op);
struct bio *n, *bio = &s->bio.bio;
struct bkey *bio_key;
unsigned int ptr;
if (bkey_cmp(k, &KEY(s->iop.inode, bio->bi_iter.bi_sector, 0)) <= 0)
return MAP_CONTINUE;
if (KEY_INODE(k) != s->iop.inode ||
KEY_START(k) > bio->bi_iter.bi_sector) {
unsigned int bio_sectors = bio_sectors(bio);
unsigned int sectors = KEY_INODE(k) == s->iop.inode
? min_t(uint64_t, INT_MAX,
KEY_START(k) - bio->bi_iter.bi_sector)
: INT_MAX;
int ret = s->d->cache_miss(b, s, bio, sectors);
if (ret != MAP_CONTINUE)
return ret;
/* if this was a complete miss we shouldn't get here */
BUG_ON(bio_sectors <= sectors);
}
if (!KEY_SIZE(k))
return MAP_CONTINUE;
/* XXX: figure out best pointer - for multiple cache devices */
ptr = 0;
PTR_BUCKET(b->c, k, ptr)->prio = INITIAL_PRIO;
if (KEY_DIRTY(k))
s->read_dirty_data = true;
n = bio_next_split(bio, min_t(uint64_t, INT_MAX,
KEY_OFFSET(k) - bio->bi_iter.bi_sector),
GFP_NOIO, &s->d->bio_split);
bio_key = &container_of(n, struct bbio, bio)->key;
bch_bkey_copy_single_ptr(bio_key, k, ptr);
bch_cut_front(&KEY(s->iop.inode, n->bi_iter.bi_sector, 0), bio_key);
bch_cut_back(&KEY(s->iop.inode, bio_end_sector(n), 0), bio_key);
n->bi_end_io = bch_cache_read_endio;
n->bi_private = &s->cl;
/*
* The bucket we're reading from might be reused while our bio
* is in flight, and we could then end up reading the wrong
* data.
*
* We guard against this by checking (in cache_read_endio()) if
* the pointer is stale again; if so, we treat it as an error
* and reread from the backing device (but we don't pass that
* error up anywhere).
*/
__bch_submit_bbio(n, b->c);
return n == bio ? MAP_DONE : MAP_CONTINUE;
}
static void cache_lookup(struct closure *cl)
{
struct search *s = container_of(cl, struct search, iop.cl);
struct bio *bio = &s->bio.bio;
struct cached_dev *dc;
int ret;
bch_btree_op_init(&s->op, -1);
ret = bch_btree_map_keys(&s->op, s->iop.c,
&KEY(s->iop.inode, bio->bi_iter.bi_sector, 0),
cache_lookup_fn, MAP_END_KEY);
if (ret == -EAGAIN) {
continue_at(cl, cache_lookup, bcache_wq);
return;
}
/*
* We might meet err when searching the btree, If that happens, we will
* get negative ret, in this scenario we should not recover data from
* backing device (when cache device is dirty) because we don't know
* whether bkeys the read request covered are all clean.
*
* And after that happened, s->iop.status is still its initial value
* before we submit s->bio.bio
*/
if (ret < 0) {
BUG_ON(ret == -EINTR);
if (s->d && s->d->c &&
!UUID_FLASH_ONLY(&s->d->c->uuids[s->d->id])) {
dc = container_of(s->d, struct cached_dev, disk);
if (dc && atomic_read(&dc->has_dirty))
s->recoverable = false;
}
if (!s->iop.status)
s->iop.status = BLK_STS_IOERR;
}
closure_return(cl);
}
/* Common code for the make_request functions */
static void request_endio(struct bio *bio)
{
struct closure *cl = bio->bi_private;
if (bio->bi_status) {
struct search *s = container_of(cl, struct search, cl);
s->iop.status = bio->bi_status;
/* Only cache read errors are recoverable */
s->recoverable = false;
}
bio_put(bio);
closure_put(cl);
}
static void backing_request_endio(struct bio *bio)
{
struct closure *cl = bio->bi_private;
if (bio->bi_status) {
struct search *s = container_of(cl, struct search, cl);
struct cached_dev *dc = container_of(s->d,
struct cached_dev, disk);
/*
* If a bio has REQ_PREFLUSH for writeback mode, it is
* speically assembled in cached_dev_write() for a non-zero
* write request which has REQ_PREFLUSH. we don't set
* s->iop.status by this failure, the status will be decided
* by result of bch_data_insert() operation.
*/
if (unlikely(s->iop.writeback &&
bio->bi_opf & REQ_PREFLUSH)) {
pr_err("Can't flush %pg: returned bi_status %i\n",
dc->bdev, bio->bi_status);
} else {
/* set to orig_bio->bi_status in bio_complete() */
s->iop.status = bio->bi_status;
}
s->recoverable = false;
/* should count I/O error for backing device here */
bch_count_backing_io_errors(dc, bio);
}
bio_put(bio);
closure_put(cl);
}
static void bio_complete(struct search *s)
{
if (s->orig_bio) {
/* Count on bcache device */
bio_end_io_acct_remapped(s->orig_bio, s->start_time,
s->orig_bdev);
trace_bcache_request_end(s->d, s->orig_bio);
s->orig_bio->bi_status = s->iop.status;
bio_endio(s->orig_bio);
s->orig_bio = NULL;
}
}
static void do_bio_hook(struct search *s,
struct bio *orig_bio,
bio_end_io_t *end_io_fn)
{
struct bio *bio = &s->bio.bio;
bio_init_clone(orig_bio->bi_bdev, bio, orig_bio, GFP_NOIO);
/*
* bi_end_io can be set separately somewhere else, e.g. the
* variants in,
* - cache_bio->bi_end_io from cached_dev_cache_miss()
* - n->bi_end_io from cache_lookup_fn()
*/
bio->bi_end_io = end_io_fn;
bio->bi_private = &s->cl;
bio_cnt_set(bio, 3);
}
static void search_free(struct closure *cl)
{
struct search *s = container_of(cl, struct search, cl);
atomic_dec(&s->iop.c->search_inflight);
if (s->iop.bio)
bio_put(s->iop.bio);
bio_complete(s);
closure_debug_destroy(cl);
mempool_free(s, &s->iop.c->search);
}
static inline struct search *search_alloc(struct bio *bio,
struct bcache_device *d, struct block_device *orig_bdev,
unsigned long start_time)
{
struct search *s;
s = mempool_alloc(&d->c->search, GFP_NOIO);
closure_init(&s->cl, NULL);
do_bio_hook(s, bio, request_endio);
atomic_inc(&d->c->search_inflight);
s->orig_bio = bio;
s->cache_miss = NULL;
s->cache_missed = 0;
s->d = d;
s->recoverable = 1;
s->write = op_is_write(bio_op(bio));
s->read_dirty_data = 0;
/* Count on the bcache device */
s->orig_bdev = orig_bdev;
s->start_time = start_time;
s->iop.c = d->c;
s->iop.bio = NULL;
s->iop.inode = d->id;
s->iop.write_point = hash_long((unsigned long) current, 16);
s->iop.write_prio = 0;
s->iop.status = 0;
s->iop.flags = 0;
s->iop.flush_journal = op_is_flush(bio->bi_opf);
s->iop.wq = bcache_wq;
return s;
}
/* Cached devices */
static void cached_dev_bio_complete(struct closure *cl)
{
struct search *s = container_of(cl, struct search, cl);
struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
cached_dev_put(dc);
search_free(cl);
}
/* Process reads */
static void cached_dev_read_error_done(struct closure *cl)
{
struct search *s = container_of(cl, struct search, cl);
if (s->iop.replace_collision)
bch_mark_cache_miss_collision(s->iop.c, s->d);
if (s->iop.bio)
bio_free_pages(s->iop.bio);
cached_dev_bio_complete(cl);
}
static void cached_dev_read_error(struct closure *cl)
{
struct search *s = container_of(cl, struct search, cl);
struct bio *bio = &s->bio.bio;
/*
* If read request hit dirty data (s->read_dirty_data is true),
* then recovery a failed read request from cached device may
* get a stale data back. So read failure recovery is only
* permitted when read request hit clean data in cache device,
* or when cache read race happened.
*/
if (s->recoverable && !s->read_dirty_data) {
/* Retry from the backing device: */
trace_bcache_read_retry(s->orig_bio);
s->iop.status = 0;
do_bio_hook(s, s->orig_bio, backing_request_endio);
/* XXX: invalidate cache */
/* I/O request sent to backing device */
closure_bio_submit(s->iop.c, bio, cl);
}
continue_at(cl, cached_dev_read_error_done, NULL);
}
static void cached_dev_cache_miss_done(struct closure *cl)
{
struct search *s = container_of(cl, struct search, cl);
struct bcache_device *d = s->d;
if (s->iop.replace_collision)
bch_mark_cache_miss_collision(s->iop.c, s->d);
if (s->iop.bio)
bio_free_pages(s->iop.bio);
cached_dev_bio_complete(cl);
closure_put(&d->cl);
}
static void cached_dev_read_done(struct closure *cl)
{
struct search *s = container_of(cl, struct search, cl);
struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
/*
* We had a cache miss; cache_bio now contains data ready to be inserted
* into the cache.
*
* First, we copy the data we just read from cache_bio's bounce buffers
* to the buffers the original bio pointed to:
*/
if (s->iop.bio) {
bio_reset(s->iop.bio, s->cache_miss->bi_bdev, REQ_OP_READ);
s->iop.bio->bi_iter.bi_sector =
s->cache_miss->bi_iter.bi_sector;
s->iop.bio->bi_iter.bi_size = s->insert_bio_sectors << 9;
bio_clone_blkg_association(s->iop.bio, s->cache_miss);
bch_bio_map(s->iop.bio, NULL);
bio_copy_data(s->cache_miss, s->iop.bio);
bio_put(s->cache_miss);
s->cache_miss = NULL;
}
if (verify(dc) && s->recoverable && !s->read_dirty_data)
bch_data_verify(dc, s->orig_bio);
closure_get(&dc->disk.cl);
bio_complete(s);
if (s->iop.bio &&
!test_bit(CACHE_SET_STOPPING, &s->iop.c->flags)) {
BUG_ON(!s->iop.replace);
closure_call(&s->iop.cl, bch_data_insert, NULL, cl);
}
continue_at(cl, cached_dev_cache_miss_done, NULL);
}
static void cached_dev_read_done_bh(struct closure *cl)
{
struct search *s = container_of(cl, struct search, cl);
struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
bch_mark_cache_accounting(s->iop.c, s->d,
!s->cache_missed, s->iop.bypass);
trace_bcache_read(s->orig_bio, !s->cache_missed, s->iop.bypass);
if (s->iop.status)
continue_at_nobarrier(cl, cached_dev_read_error, bcache_wq);
else if (s->iop.bio || verify(dc))
continue_at_nobarrier(cl, cached_dev_read_done, bcache_wq);
else
continue_at_nobarrier(cl, cached_dev_bio_complete, NULL);
}
static int cached_dev_cache_miss(struct btree *b, struct search *s,
struct bio *bio, unsigned int sectors)
{
int ret = MAP_CONTINUE;
struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
struct bio *miss, *cache_bio;
unsigned int size_limit;
s->cache_missed = 1;
if (s->cache_miss || s->iop.bypass) {
miss = bio_next_split(bio, sectors, GFP_NOIO, &s->d->bio_split);
ret = miss == bio ? MAP_DONE : MAP_CONTINUE;
goto out_submit;
}
/* Limitation for valid replace key size and cache_bio bvecs number */
size_limit = min_t(unsigned int, BIO_MAX_VECS * PAGE_SECTORS,
(1 << KEY_SIZE_BITS) - 1);
s->insert_bio_sectors = min3(size_limit, sectors, bio_sectors(bio));
s->iop.replace_key = KEY(s->iop.inode,
bio->bi_iter.bi_sector + s->insert_bio_sectors,
s->insert_bio_sectors);
ret = bch_btree_insert_check_key(b, &s->op, &s->iop.replace_key);
if (ret)
return ret;
s->iop.replace = true;
miss = bio_next_split(bio, s->insert_bio_sectors, GFP_NOIO,
&s->d->bio_split);
/* btree_search_recurse()'s btree iterator is no good anymore */
ret = miss == bio ? MAP_DONE : -EINTR;
cache_bio = bio_alloc_bioset(miss->bi_bdev,
DIV_ROUND_UP(s->insert_bio_sectors, PAGE_SECTORS),
0, GFP_NOWAIT, &dc->disk.bio_split);
if (!cache_bio)
goto out_submit;
cache_bio->bi_iter.bi_sector = miss->bi_iter.bi_sector;
cache_bio->bi_iter.bi_size = s->insert_bio_sectors << 9;
cache_bio->bi_end_io = backing_request_endio;
cache_bio->bi_private = &s->cl;
bch_bio_map(cache_bio, NULL);
if (bch_bio_alloc_pages(cache_bio, __GFP_NOWARN|GFP_NOIO))
goto out_put;
s->cache_miss = miss;
s->iop.bio = cache_bio;
bio_get(cache_bio);
/* I/O request sent to backing device */
closure_bio_submit(s->iop.c, cache_bio, &s->cl);
return ret;
out_put:
bio_put(cache_bio);
out_submit:
miss->bi_end_io = backing_request_endio;
miss->bi_private = &s->cl;
/* I/O request sent to backing device */
closure_bio_submit(s->iop.c, miss, &s->cl);
return ret;
}
static void cached_dev_read(struct cached_dev *dc, struct search *s)
{
struct closure *cl = &s->cl;
closure_call(&s->iop.cl, cache_lookup, NULL, cl);
continue_at(cl, cached_dev_read_done_bh, NULL);
}
/* Process writes */
static void cached_dev_write_complete(struct closure *cl)
{
struct search *s = container_of(cl, struct search, cl);
struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
up_read_non_owner(&dc->writeback_lock);
cached_dev_bio_complete(cl);
}
static void cached_dev_write(struct cached_dev *dc, struct search *s)
{
struct closure *cl = &s->cl;
struct bio *bio = &s->bio.bio;
struct bkey start = KEY(dc->disk.id, bio->bi_iter.bi_sector, 0);
struct bkey end = KEY(dc->disk.id, bio_end_sector(bio), 0);
bch_keybuf_check_overlapping(&s->iop.c->moving_gc_keys, &start, &end);
down_read_non_owner(&dc->writeback_lock);
if (bch_keybuf_check_overlapping(&dc->writeback_keys, &start, &end)) {
/*
* We overlap with some dirty data undergoing background
* writeback, force this write to writeback
*/
s->iop.bypass = false;
s->iop.writeback = true;
}
/*
* Discards aren't _required_ to do anything, so skipping if
* check_overlapping returned true is ok
*
* But check_overlapping drops dirty keys for which io hasn't started,
* so we still want to call it.
*/
if (bio_op(bio) == REQ_OP_DISCARD)
s->iop.bypass = true;
if (should_writeback(dc, s->orig_bio,
cache_mode(dc),
s->iop.bypass)) {
s->iop.bypass = false;
s->iop.writeback = true;
}
if (s->iop.bypass) {
s->iop.bio = s->orig_bio;
bio_get(s->iop.bio);
if (bio_op(bio) == REQ_OP_DISCARD &&
!bdev_max_discard_sectors(dc->bdev))
goto insert_data;
/* I/O request sent to backing device */
bio->bi_end_io = backing_request_endio;
closure_bio_submit(s->iop.c, bio, cl);
} else if (s->iop.writeback) {
bch_writeback_add(dc);
s->iop.bio = bio;
if (bio->bi_opf & REQ_PREFLUSH) {
/*
* Also need to send a flush to the backing
* device.
*/
struct bio *flush;
flush = bio_alloc_bioset(bio->bi_bdev, 0,
REQ_OP_WRITE | REQ_PREFLUSH,
GFP_NOIO, &dc->disk.bio_split);
if (!flush) {
s->iop.status = BLK_STS_RESOURCE;
goto insert_data;
}
flush->bi_end_io = backing_request_endio;
flush->bi_private = cl;
/* I/O request sent to backing device */
closure_bio_submit(s->iop.c, flush, cl);
}
} else {
s->iop.bio = bio_alloc_clone(bio->bi_bdev, bio, GFP_NOIO,
&dc->disk.bio_split);
/* I/O request sent to backing device */
bio->bi_end_io = backing_request_endio;
closure_bio_submit(s->iop.c, bio, cl);
}
insert_data:
closure_call(&s->iop.cl, bch_data_insert, NULL, cl);
continue_at(cl, cached_dev_write_complete, NULL);
}
static void cached_dev_nodata(struct closure *cl)
{
struct search *s = container_of(cl, struct search, cl);
struct bio *bio = &s->bio.bio;
if (s->iop.flush_journal)
bch_journal_meta(s->iop.c, cl);
/* If it's a flush, we send the flush to the backing device too */
bio->bi_end_io = backing_request_endio;
closure_bio_submit(s->iop.c, bio, cl);
continue_at(cl, cached_dev_bio_complete, NULL);
}
struct detached_dev_io_private {
struct bcache_device *d;
unsigned long start_time;
bio_end_io_t *bi_end_io;
void *bi_private;
struct block_device *orig_bdev;
};
static void detached_dev_end_io(struct bio *bio)
{
struct detached_dev_io_private *ddip;
ddip = bio->bi_private;
bio->bi_end_io = ddip->bi_end_io;
bio->bi_private = ddip->bi_private;
/* Count on the bcache device */
bio_end_io_acct_remapped(bio, ddip->start_time, ddip->orig_bdev);
if (bio->bi_status) {
struct cached_dev *dc = container_of(ddip->d,
struct cached_dev, disk);
/* should count I/O error for backing device here */
bch_count_backing_io_errors(dc, bio);
}
kfree(ddip);
bio->bi_end_io(bio);
}
static void detached_dev_do_request(struct bcache_device *d, struct bio *bio,
struct block_device *orig_bdev, unsigned long start_time)
{
struct detached_dev_io_private *ddip;
struct cached_dev *dc = container_of(d, struct cached_dev, disk);
/*
* no need to call closure_get(&dc->disk.cl),
* because upper layer had already opened bcache device,
* which would call closure_get(&dc->disk.cl)
*/
ddip = kzalloc(sizeof(struct detached_dev_io_private), GFP_NOIO);
if (!ddip) {
bio->bi_status = BLK_STS_RESOURCE;
bio->bi_end_io(bio);
return;
}
ddip->d = d;
/* Count on the bcache device */
ddip->orig_bdev = orig_bdev;
ddip->start_time = start_time;
ddip->bi_end_io = bio->bi_end_io;
ddip->bi_private = bio->bi_private;
bio->bi_end_io = detached_dev_end_io;
bio->bi_private = ddip;
if ((bio_op(bio) == REQ_OP_DISCARD) &&
!bdev_max_discard_sectors(dc->bdev))
bio->bi_end_io(bio);
else
submit_bio_noacct(bio);
}
static void quit_max_writeback_rate(struct cache_set *c,
struct cached_dev *this_dc)
{
int i;
struct bcache_device *d;
struct cached_dev *dc;
/*
* mutex bch_register_lock may compete with other parallel requesters,
* or attach/detach operations on other backing device. Waiting to
* the mutex lock may increase I/O request latency for seconds or more.
* To avoid such situation, if mutext_trylock() failed, only writeback
* rate of current cached device is set to 1, and __update_write_back()
* will decide writeback rate of other cached devices (remember now
* c->idle_counter is 0 already).
*/
if (mutex_trylock(&bch_register_lock)) {
for (i = 0; i < c->devices_max_used; i++) {
if (!c->devices[i])
continue;
if (UUID_FLASH_ONLY(&c->uuids[i]))
continue;
d = c->devices[i];
dc = container_of(d, struct cached_dev, disk);
/*
* set writeback rate to default minimum value,
* then let update_writeback_rate() to decide the
* upcoming rate.
*/
atomic_long_set(&dc->writeback_rate.rate, 1);
}
mutex_unlock(&bch_register_lock);
} else
atomic_long_set(&this_dc->writeback_rate.rate, 1);
}
/* Cached devices - read & write stuff */
void cached_dev_submit_bio(struct bio *bio)
{
struct search *s;
struct block_device *orig_bdev = bio->bi_bdev;
struct bcache_device *d = orig_bdev->bd_disk->private_data;
struct cached_dev *dc = container_of(d, struct cached_dev, disk);
unsigned long start_time;
int rw = bio_data_dir(bio);
if (unlikely((d->c && test_bit(CACHE_SET_IO_DISABLE, &d->c->flags)) ||
dc->io_disable)) {
bio->bi_status = BLK_STS_IOERR;
bio_endio(bio);
return;
}
if (likely(d->c)) {
if (atomic_read(&d->c->idle_counter))
atomic_set(&d->c->idle_counter, 0);
/*
* If at_max_writeback_rate of cache set is true and new I/O
* comes, quit max writeback rate of all cached devices
* attached to this cache set, and set at_max_writeback_rate
* to false.
*/
if (unlikely(atomic_read(&d->c->at_max_writeback_rate) == 1)) {
atomic_set(&d->c->at_max_writeback_rate, 0);
quit_max_writeback_rate(d->c, dc);
}
}
start_time = bio_start_io_acct(bio);
bio_set_dev(bio, dc->bdev);
bio->bi_iter.bi_sector += dc->sb.data_offset;
if (cached_dev_get(dc)) {
s = search_alloc(bio, d, orig_bdev, start_time);
trace_bcache_request_start(s->d, bio);
if (!bio->bi_iter.bi_size) {
/*
* can't call bch_journal_meta from under
* submit_bio_noacct
*/
continue_at_nobarrier(&s->cl,
cached_dev_nodata,
bcache_wq);
} else {
s->iop.bypass = check_should_bypass(dc, bio);
if (rw)
cached_dev_write(dc, s);
else
cached_dev_read(dc, s);
}
} else
/* I/O request sent to backing device */
detached_dev_do_request(d, bio, orig_bdev, start_time);
}
static int cached_dev_ioctl(struct bcache_device *d, blk_mode_t mode,
unsigned int cmd, unsigned long arg)
{
struct cached_dev *dc = container_of(d, struct cached_dev, disk);
if (dc->io_disable)
return -EIO;
if (!dc->bdev->bd_disk->fops->ioctl)
return -ENOTTY;
return dc->bdev->bd_disk->fops->ioctl(dc->bdev, mode, cmd, arg);
}
void bch_cached_dev_request_init(struct cached_dev *dc)
{
dc->disk.cache_miss = cached_dev_cache_miss;
dc->disk.ioctl = cached_dev_ioctl;
}
/* Flash backed devices */
static int flash_dev_cache_miss(struct btree *b, struct search *s,
struct bio *bio, unsigned int sectors)
{
unsigned int bytes = min(sectors, bio_sectors(bio)) << 9;
swap(bio->bi_iter.bi_size, bytes);
zero_fill_bio(bio);
swap(bio->bi_iter.bi_size, bytes);
bio_advance(bio, bytes);
if (!bio->bi_iter.bi_size)
return MAP_DONE;
return MAP_CONTINUE;
}
static void flash_dev_nodata(struct closure *cl)
{
struct search *s = container_of(cl, struct search, cl);
if (s->iop.flush_journal)
bch_journal_meta(s->iop.c, cl);
continue_at(cl, search_free, NULL);
}
void flash_dev_submit_bio(struct bio *bio)
{
struct search *s;
struct closure *cl;
struct bcache_device *d = bio->bi_bdev->bd_disk->private_data;
if (unlikely(d->c && test_bit(CACHE_SET_IO_DISABLE, &d->c->flags))) {
bio->bi_status = BLK_STS_IOERR;
bio_endio(bio);
return;
}
s = search_alloc(bio, d, bio->bi_bdev, bio_start_io_acct(bio));
cl = &s->cl;
bio = &s->bio.bio;
trace_bcache_request_start(s->d, bio);
if (!bio->bi_iter.bi_size) {
/*
* can't call bch_journal_meta from under submit_bio_noacct
*/
continue_at_nobarrier(&s->cl,
flash_dev_nodata,
bcache_wq);
return;
} else if (bio_data_dir(bio)) {
bch_keybuf_check_overlapping(&s->iop.c->moving_gc_keys,
&KEY(d->id, bio->bi_iter.bi_sector, 0),
&KEY(d->id, bio_end_sector(bio), 0));
s->iop.bypass = (bio_op(bio) == REQ_OP_DISCARD) != 0;
s->iop.writeback = true;
s->iop.bio = bio;
closure_call(&s->iop.cl, bch_data_insert, NULL, cl);
} else {
closure_call(&s->iop.cl, cache_lookup, NULL, cl);
}
continue_at(cl, search_free, NULL);
}
static int flash_dev_ioctl(struct bcache_device *d, blk_mode_t mode,
unsigned int cmd, unsigned long arg)
{
return -ENOTTY;
}
void bch_flash_dev_request_init(struct bcache_device *d)
{
d->cache_miss = flash_dev_cache_miss;
d->ioctl = flash_dev_ioctl;
}
void bch_request_exit(void)
{
kmem_cache_destroy(bch_search_cache);
}
int __init bch_request_init(void)
{
bch_search_cache = KMEM_CACHE(search, 0);
if (!bch_search_cache)
return -ENOMEM;
return 0;
}
| linux-master | drivers/md/bcache/request.c |
// SPDX-License-Identifier: GPL-2.0
/*
* bcache sysfs interfaces
*
* Copyright 2010, 2011 Kent Overstreet <[email protected]>
* Copyright 2012 Google, Inc.
*/
#include "bcache.h"
#include "sysfs.h"
#include "btree.h"
#include "request.h"
#include "writeback.h"
#include "features.h"
#include <linux/blkdev.h>
#include <linux/sort.h>
#include <linux/sched/clock.h>
extern bool bcache_is_reboot;
/* Default is 0 ("writethrough") */
static const char * const bch_cache_modes[] = {
"writethrough",
"writeback",
"writearound",
"none",
NULL
};
static const char * const bch_reada_cache_policies[] = {
"all",
"meta-only",
NULL
};
/* Default is 0 ("auto") */
static const char * const bch_stop_on_failure_modes[] = {
"auto",
"always",
NULL
};
static const char * const cache_replacement_policies[] = {
"lru",
"fifo",
"random",
NULL
};
static const char * const error_actions[] = {
"unregister",
"panic",
NULL
};
write_attribute(attach);
write_attribute(detach);
write_attribute(unregister);
write_attribute(stop);
write_attribute(clear_stats);
write_attribute(trigger_gc);
write_attribute(prune_cache);
write_attribute(flash_vol_create);
read_attribute(bucket_size);
read_attribute(block_size);
read_attribute(nbuckets);
read_attribute(tree_depth);
read_attribute(root_usage_percent);
read_attribute(priority_stats);
read_attribute(btree_cache_size);
read_attribute(btree_cache_max_chain);
read_attribute(cache_available_percent);
read_attribute(written);
read_attribute(btree_written);
read_attribute(metadata_written);
read_attribute(active_journal_entries);
read_attribute(backing_dev_name);
read_attribute(backing_dev_uuid);
sysfs_time_stats_attribute(btree_gc, sec, ms);
sysfs_time_stats_attribute(btree_split, sec, us);
sysfs_time_stats_attribute(btree_sort, ms, us);
sysfs_time_stats_attribute(btree_read, ms, us);
read_attribute(btree_nodes);
read_attribute(btree_used_percent);
read_attribute(average_key_size);
read_attribute(dirty_data);
read_attribute(bset_tree_stats);
read_attribute(feature_compat);
read_attribute(feature_ro_compat);
read_attribute(feature_incompat);
read_attribute(state);
read_attribute(cache_read_races);
read_attribute(reclaim);
read_attribute(reclaimed_journal_buckets);
read_attribute(flush_write);
read_attribute(writeback_keys_done);
read_attribute(writeback_keys_failed);
read_attribute(io_errors);
read_attribute(congested);
read_attribute(cutoff_writeback);
read_attribute(cutoff_writeback_sync);
rw_attribute(congested_read_threshold_us);
rw_attribute(congested_write_threshold_us);
rw_attribute(sequential_cutoff);
rw_attribute(data_csum);
rw_attribute(cache_mode);
rw_attribute(readahead_cache_policy);
rw_attribute(stop_when_cache_set_failed);
rw_attribute(writeback_metadata);
rw_attribute(writeback_running);
rw_attribute(writeback_percent);
rw_attribute(writeback_delay);
rw_attribute(writeback_rate);
rw_attribute(writeback_consider_fragment);
rw_attribute(writeback_rate_update_seconds);
rw_attribute(writeback_rate_i_term_inverse);
rw_attribute(writeback_rate_p_term_inverse);
rw_attribute(writeback_rate_fp_term_low);
rw_attribute(writeback_rate_fp_term_mid);
rw_attribute(writeback_rate_fp_term_high);
rw_attribute(writeback_rate_minimum);
read_attribute(writeback_rate_debug);
read_attribute(stripe_size);
read_attribute(partial_stripes_expensive);
rw_attribute(synchronous);
rw_attribute(journal_delay_ms);
rw_attribute(io_disable);
rw_attribute(discard);
rw_attribute(running);
rw_attribute(label);
rw_attribute(errors);
rw_attribute(io_error_limit);
rw_attribute(io_error_halflife);
rw_attribute(verify);
rw_attribute(bypass_torture_test);
rw_attribute(key_merging_disabled);
rw_attribute(gc_always_rewrite);
rw_attribute(expensive_debug_checks);
rw_attribute(cache_replacement_policy);
rw_attribute(btree_shrinker_disabled);
rw_attribute(copy_gc_enabled);
rw_attribute(idle_max_writeback_rate);
rw_attribute(gc_after_writeback);
rw_attribute(size);
static ssize_t bch_snprint_string_list(char *buf,
size_t size,
const char * const list[],
size_t selected)
{
char *out = buf;
size_t i;
for (i = 0; list[i]; i++)
out += scnprintf(out, buf + size - out,
i == selected ? "[%s] " : "%s ", list[i]);
out[-1] = '\n';
return out - buf;
}
SHOW(__bch_cached_dev)
{
struct cached_dev *dc = container_of(kobj, struct cached_dev,
disk.kobj);
char const *states[] = { "no cache", "clean", "dirty", "inconsistent" };
int wb = dc->writeback_running;
#define var(stat) (dc->stat)
if (attr == &sysfs_cache_mode)
return bch_snprint_string_list(buf, PAGE_SIZE,
bch_cache_modes,
BDEV_CACHE_MODE(&dc->sb));
if (attr == &sysfs_readahead_cache_policy)
return bch_snprint_string_list(buf, PAGE_SIZE,
bch_reada_cache_policies,
dc->cache_readahead_policy);
if (attr == &sysfs_stop_when_cache_set_failed)
return bch_snprint_string_list(buf, PAGE_SIZE,
bch_stop_on_failure_modes,
dc->stop_when_cache_set_failed);
sysfs_printf(data_csum, "%i", dc->disk.data_csum);
var_printf(verify, "%i");
var_printf(bypass_torture_test, "%i");
var_printf(writeback_metadata, "%i");
var_printf(writeback_running, "%i");
var_printf(writeback_consider_fragment, "%i");
var_print(writeback_delay);
var_print(writeback_percent);
sysfs_hprint(writeback_rate,
wb ? atomic_long_read(&dc->writeback_rate.rate) << 9 : 0);
sysfs_printf(io_errors, "%i", atomic_read(&dc->io_errors));
sysfs_printf(io_error_limit, "%i", dc->error_limit);
sysfs_printf(io_disable, "%i", dc->io_disable);
var_print(writeback_rate_update_seconds);
var_print(writeback_rate_i_term_inverse);
var_print(writeback_rate_p_term_inverse);
var_print(writeback_rate_fp_term_low);
var_print(writeback_rate_fp_term_mid);
var_print(writeback_rate_fp_term_high);
var_print(writeback_rate_minimum);
if (attr == &sysfs_writeback_rate_debug) {
char rate[20];
char dirty[20];
char target[20];
char proportional[20];
char integral[20];
char change[20];
s64 next_io;
/*
* Except for dirty and target, other values should
* be 0 if writeback is not running.
*/
bch_hprint(rate,
wb ? atomic_long_read(&dc->writeback_rate.rate) << 9
: 0);
bch_hprint(dirty, bcache_dev_sectors_dirty(&dc->disk) << 9);
bch_hprint(target, dc->writeback_rate_target << 9);
bch_hprint(proportional,
wb ? dc->writeback_rate_proportional << 9 : 0);
bch_hprint(integral,
wb ? dc->writeback_rate_integral_scaled << 9 : 0);
bch_hprint(change, wb ? dc->writeback_rate_change << 9 : 0);
next_io = wb ? div64_s64(dc->writeback_rate.next-local_clock(),
NSEC_PER_MSEC) : 0;
return sprintf(buf,
"rate:\t\t%s/sec\n"
"dirty:\t\t%s\n"
"target:\t\t%s\n"
"proportional:\t%s\n"
"integral:\t%s\n"
"change:\t\t%s/sec\n"
"next io:\t%llims\n",
rate, dirty, target, proportional,
integral, change, next_io);
}
sysfs_hprint(dirty_data,
bcache_dev_sectors_dirty(&dc->disk) << 9);
sysfs_hprint(stripe_size, ((uint64_t)dc->disk.stripe_size) << 9);
var_printf(partial_stripes_expensive, "%u");
var_hprint(sequential_cutoff);
sysfs_print(running, atomic_read(&dc->running));
sysfs_print(state, states[BDEV_STATE(&dc->sb)]);
if (attr == &sysfs_label) {
memcpy(buf, dc->sb.label, SB_LABEL_SIZE);
buf[SB_LABEL_SIZE + 1] = '\0';
strcat(buf, "\n");
return strlen(buf);
}
if (attr == &sysfs_backing_dev_name) {
snprintf(buf, BDEVNAME_SIZE + 1, "%pg", dc->bdev);
strcat(buf, "\n");
return strlen(buf);
}
if (attr == &sysfs_backing_dev_uuid) {
/* convert binary uuid into 36-byte string plus '\0' */
snprintf(buf, 36+1, "%pU", dc->sb.uuid);
strcat(buf, "\n");
return strlen(buf);
}
#undef var
return 0;
}
SHOW_LOCKED(bch_cached_dev)
STORE(__cached_dev)
{
struct cached_dev *dc = container_of(kobj, struct cached_dev,
disk.kobj);
ssize_t v;
struct cache_set *c;
struct kobj_uevent_env *env;
/* no user space access if system is rebooting */
if (bcache_is_reboot)
return -EBUSY;
#define d_strtoul(var) sysfs_strtoul(var, dc->var)
#define d_strtoul_nonzero(var) sysfs_strtoul_clamp(var, dc->var, 1, INT_MAX)
#define d_strtoi_h(var) sysfs_hatoi(var, dc->var)
sysfs_strtoul(data_csum, dc->disk.data_csum);
d_strtoul(verify);
sysfs_strtoul_bool(bypass_torture_test, dc->bypass_torture_test);
sysfs_strtoul_bool(writeback_metadata, dc->writeback_metadata);
sysfs_strtoul_bool(writeback_running, dc->writeback_running);
sysfs_strtoul_bool(writeback_consider_fragment, dc->writeback_consider_fragment);
sysfs_strtoul_clamp(writeback_delay, dc->writeback_delay, 0, UINT_MAX);
sysfs_strtoul_clamp(writeback_percent, dc->writeback_percent,
0, bch_cutoff_writeback);
if (attr == &sysfs_writeback_rate) {
ssize_t ret;
long int v = atomic_long_read(&dc->writeback_rate.rate);
ret = strtoul_safe_clamp(buf, v, 1, INT_MAX);
if (!ret) {
atomic_long_set(&dc->writeback_rate.rate, v);
ret = size;
}
return ret;
}
sysfs_strtoul_clamp(writeback_rate_update_seconds,
dc->writeback_rate_update_seconds,
1, WRITEBACK_RATE_UPDATE_SECS_MAX);
sysfs_strtoul_clamp(writeback_rate_i_term_inverse,
dc->writeback_rate_i_term_inverse,
1, UINT_MAX);
sysfs_strtoul_clamp(writeback_rate_p_term_inverse,
dc->writeback_rate_p_term_inverse,
1, UINT_MAX);
sysfs_strtoul_clamp(writeback_rate_fp_term_low,
dc->writeback_rate_fp_term_low,
1, dc->writeback_rate_fp_term_mid - 1);
sysfs_strtoul_clamp(writeback_rate_fp_term_mid,
dc->writeback_rate_fp_term_mid,
dc->writeback_rate_fp_term_low + 1,
dc->writeback_rate_fp_term_high - 1);
sysfs_strtoul_clamp(writeback_rate_fp_term_high,
dc->writeback_rate_fp_term_high,
dc->writeback_rate_fp_term_mid + 1, UINT_MAX);
sysfs_strtoul_clamp(writeback_rate_minimum,
dc->writeback_rate_minimum,
1, UINT_MAX);
sysfs_strtoul_clamp(io_error_limit, dc->error_limit, 0, INT_MAX);
if (attr == &sysfs_io_disable) {
int v = strtoul_or_return(buf);
dc->io_disable = v ? 1 : 0;
}
sysfs_strtoul_clamp(sequential_cutoff,
dc->sequential_cutoff,
0, UINT_MAX);
if (attr == &sysfs_clear_stats)
bch_cache_accounting_clear(&dc->accounting);
if (attr == &sysfs_running &&
strtoul_or_return(buf)) {
v = bch_cached_dev_run(dc);
if (v)
return v;
}
if (attr == &sysfs_cache_mode) {
v = __sysfs_match_string(bch_cache_modes, -1, buf);
if (v < 0)
return v;
if ((unsigned int) v != BDEV_CACHE_MODE(&dc->sb)) {
SET_BDEV_CACHE_MODE(&dc->sb, v);
bch_write_bdev_super(dc, NULL);
}
}
if (attr == &sysfs_readahead_cache_policy) {
v = __sysfs_match_string(bch_reada_cache_policies, -1, buf);
if (v < 0)
return v;
if ((unsigned int) v != dc->cache_readahead_policy)
dc->cache_readahead_policy = v;
}
if (attr == &sysfs_stop_when_cache_set_failed) {
v = __sysfs_match_string(bch_stop_on_failure_modes, -1, buf);
if (v < 0)
return v;
dc->stop_when_cache_set_failed = v;
}
if (attr == &sysfs_label) {
if (size > SB_LABEL_SIZE)
return -EINVAL;
memcpy(dc->sb.label, buf, size);
if (size < SB_LABEL_SIZE)
dc->sb.label[size] = '\0';
if (size && dc->sb.label[size - 1] == '\n')
dc->sb.label[size - 1] = '\0';
bch_write_bdev_super(dc, NULL);
if (dc->disk.c) {
memcpy(dc->disk.c->uuids[dc->disk.id].label,
buf, SB_LABEL_SIZE);
bch_uuid_write(dc->disk.c);
}
env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
if (!env)
return -ENOMEM;
add_uevent_var(env, "DRIVER=bcache");
add_uevent_var(env, "CACHED_UUID=%pU", dc->sb.uuid);
add_uevent_var(env, "CACHED_LABEL=%s", buf);
kobject_uevent_env(&disk_to_dev(dc->disk.disk)->kobj,
KOBJ_CHANGE,
env->envp);
kfree(env);
}
if (attr == &sysfs_attach) {
uint8_t set_uuid[16];
if (bch_parse_uuid(buf, set_uuid) < 16)
return -EINVAL;
v = -ENOENT;
list_for_each_entry(c, &bch_cache_sets, list) {
v = bch_cached_dev_attach(dc, c, set_uuid);
if (!v)
return size;
}
if (v == -ENOENT)
pr_err("Can't attach %s: cache set not found\n", buf);
return v;
}
if (attr == &sysfs_detach && dc->disk.c)
bch_cached_dev_detach(dc);
if (attr == &sysfs_stop)
bcache_device_stop(&dc->disk);
return size;
}
STORE(bch_cached_dev)
{
struct cached_dev *dc = container_of(kobj, struct cached_dev,
disk.kobj);
/* no user space access if system is rebooting */
if (bcache_is_reboot)
return -EBUSY;
mutex_lock(&bch_register_lock);
size = __cached_dev_store(kobj, attr, buf, size);
if (attr == &sysfs_writeback_running) {
/* dc->writeback_running changed in __cached_dev_store() */
if (IS_ERR_OR_NULL(dc->writeback_thread)) {
/*
* reject setting it to 1 via sysfs if writeback
* kthread is not created yet.
*/
if (dc->writeback_running) {
dc->writeback_running = false;
pr_err("%s: failed to run non-existent writeback thread\n",
dc->disk.disk->disk_name);
}
} else
/*
* writeback kthread will check if dc->writeback_running
* is true or false.
*/
bch_writeback_queue(dc);
}
/*
* Only set BCACHE_DEV_WB_RUNNING when cached device attached to
* a cache set, otherwise it doesn't make sense.
*/
if (attr == &sysfs_writeback_percent)
if ((dc->disk.c != NULL) &&
(!test_and_set_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags)))
schedule_delayed_work(&dc->writeback_rate_update,
dc->writeback_rate_update_seconds * HZ);
mutex_unlock(&bch_register_lock);
return size;
}
static struct attribute *bch_cached_dev_attrs[] = {
&sysfs_attach,
&sysfs_detach,
&sysfs_stop,
#if 0
&sysfs_data_csum,
#endif
&sysfs_cache_mode,
&sysfs_readahead_cache_policy,
&sysfs_stop_when_cache_set_failed,
&sysfs_writeback_metadata,
&sysfs_writeback_running,
&sysfs_writeback_delay,
&sysfs_writeback_percent,
&sysfs_writeback_rate,
&sysfs_writeback_consider_fragment,
&sysfs_writeback_rate_update_seconds,
&sysfs_writeback_rate_i_term_inverse,
&sysfs_writeback_rate_p_term_inverse,
&sysfs_writeback_rate_fp_term_low,
&sysfs_writeback_rate_fp_term_mid,
&sysfs_writeback_rate_fp_term_high,
&sysfs_writeback_rate_minimum,
&sysfs_writeback_rate_debug,
&sysfs_io_errors,
&sysfs_io_error_limit,
&sysfs_io_disable,
&sysfs_dirty_data,
&sysfs_stripe_size,
&sysfs_partial_stripes_expensive,
&sysfs_sequential_cutoff,
&sysfs_clear_stats,
&sysfs_running,
&sysfs_state,
&sysfs_label,
#ifdef CONFIG_BCACHE_DEBUG
&sysfs_verify,
&sysfs_bypass_torture_test,
#endif
&sysfs_backing_dev_name,
&sysfs_backing_dev_uuid,
NULL
};
ATTRIBUTE_GROUPS(bch_cached_dev);
KTYPE(bch_cached_dev);
SHOW(bch_flash_dev)
{
struct bcache_device *d = container_of(kobj, struct bcache_device,
kobj);
struct uuid_entry *u = &d->c->uuids[d->id];
sysfs_printf(data_csum, "%i", d->data_csum);
sysfs_hprint(size, u->sectors << 9);
if (attr == &sysfs_label) {
memcpy(buf, u->label, SB_LABEL_SIZE);
buf[SB_LABEL_SIZE + 1] = '\0';
strcat(buf, "\n");
return strlen(buf);
}
return 0;
}
STORE(__bch_flash_dev)
{
struct bcache_device *d = container_of(kobj, struct bcache_device,
kobj);
struct uuid_entry *u = &d->c->uuids[d->id];
/* no user space access if system is rebooting */
if (bcache_is_reboot)
return -EBUSY;
sysfs_strtoul(data_csum, d->data_csum);
if (attr == &sysfs_size) {
uint64_t v;
strtoi_h_or_return(buf, v);
u->sectors = v >> 9;
bch_uuid_write(d->c);
set_capacity(d->disk, u->sectors);
}
if (attr == &sysfs_label) {
memcpy(u->label, buf, SB_LABEL_SIZE);
bch_uuid_write(d->c);
}
if (attr == &sysfs_unregister) {
set_bit(BCACHE_DEV_DETACHING, &d->flags);
bcache_device_stop(d);
}
return size;
}
STORE_LOCKED(bch_flash_dev)
static struct attribute *bch_flash_dev_attrs[] = {
&sysfs_unregister,
#if 0
&sysfs_data_csum,
#endif
&sysfs_label,
&sysfs_size,
NULL
};
ATTRIBUTE_GROUPS(bch_flash_dev);
KTYPE(bch_flash_dev);
struct bset_stats_op {
struct btree_op op;
size_t nodes;
struct bset_stats stats;
};
static int bch_btree_bset_stats(struct btree_op *b_op, struct btree *b)
{
struct bset_stats_op *op = container_of(b_op, struct bset_stats_op, op);
op->nodes++;
bch_btree_keys_stats(&b->keys, &op->stats);
return MAP_CONTINUE;
}
static int bch_bset_print_stats(struct cache_set *c, char *buf)
{
struct bset_stats_op op;
int ret;
memset(&op, 0, sizeof(op));
bch_btree_op_init(&op.op, -1);
ret = bch_btree_map_nodes(&op.op, c, &ZERO_KEY, bch_btree_bset_stats);
if (ret < 0)
return ret;
return snprintf(buf, PAGE_SIZE,
"btree nodes: %zu\n"
"written sets: %zu\n"
"unwritten sets: %zu\n"
"written key bytes: %zu\n"
"unwritten key bytes: %zu\n"
"floats: %zu\n"
"failed: %zu\n",
op.nodes,
op.stats.sets_written, op.stats.sets_unwritten,
op.stats.bytes_written, op.stats.bytes_unwritten,
op.stats.floats, op.stats.failed);
}
static unsigned int bch_root_usage(struct cache_set *c)
{
unsigned int bytes = 0;
struct bkey *k;
struct btree *b;
struct btree_iter iter;
goto lock_root;
do {
rw_unlock(false, b);
lock_root:
b = c->root;
rw_lock(false, b, b->level);
} while (b != c->root);
for_each_key_filter(&b->keys, k, &iter, bch_ptr_bad)
bytes += bkey_bytes(k);
rw_unlock(false, b);
return (bytes * 100) / btree_bytes(c);
}
static size_t bch_cache_size(struct cache_set *c)
{
size_t ret = 0;
struct btree *b;
mutex_lock(&c->bucket_lock);
list_for_each_entry(b, &c->btree_cache, list)
ret += 1 << (b->keys.page_order + PAGE_SHIFT);
mutex_unlock(&c->bucket_lock);
return ret;
}
static unsigned int bch_cache_max_chain(struct cache_set *c)
{
unsigned int ret = 0;
struct hlist_head *h;
mutex_lock(&c->bucket_lock);
for (h = c->bucket_hash;
h < c->bucket_hash + (1 << BUCKET_HASH_BITS);
h++) {
unsigned int i = 0;
struct hlist_node *p;
hlist_for_each(p, h)
i++;
ret = max(ret, i);
}
mutex_unlock(&c->bucket_lock);
return ret;
}
static unsigned int bch_btree_used(struct cache_set *c)
{
return div64_u64(c->gc_stats.key_bytes * 100,
(c->gc_stats.nodes ?: 1) * btree_bytes(c));
}
static unsigned int bch_average_key_size(struct cache_set *c)
{
return c->gc_stats.nkeys
? div64_u64(c->gc_stats.data, c->gc_stats.nkeys)
: 0;
}
SHOW(__bch_cache_set)
{
struct cache_set *c = container_of(kobj, struct cache_set, kobj);
sysfs_print(synchronous, CACHE_SYNC(&c->cache->sb));
sysfs_print(journal_delay_ms, c->journal_delay_ms);
sysfs_hprint(bucket_size, bucket_bytes(c->cache));
sysfs_hprint(block_size, block_bytes(c->cache));
sysfs_print(tree_depth, c->root->level);
sysfs_print(root_usage_percent, bch_root_usage(c));
sysfs_hprint(btree_cache_size, bch_cache_size(c));
sysfs_print(btree_cache_max_chain, bch_cache_max_chain(c));
sysfs_print(cache_available_percent, 100 - c->gc_stats.in_use);
sysfs_print_time_stats(&c->btree_gc_time, btree_gc, sec, ms);
sysfs_print_time_stats(&c->btree_split_time, btree_split, sec, us);
sysfs_print_time_stats(&c->sort.time, btree_sort, ms, us);
sysfs_print_time_stats(&c->btree_read_time, btree_read, ms, us);
sysfs_print(btree_used_percent, bch_btree_used(c));
sysfs_print(btree_nodes, c->gc_stats.nodes);
sysfs_hprint(average_key_size, bch_average_key_size(c));
sysfs_print(cache_read_races,
atomic_long_read(&c->cache_read_races));
sysfs_print(reclaim,
atomic_long_read(&c->reclaim));
sysfs_print(reclaimed_journal_buckets,
atomic_long_read(&c->reclaimed_journal_buckets));
sysfs_print(flush_write,
atomic_long_read(&c->flush_write));
sysfs_print(writeback_keys_done,
atomic_long_read(&c->writeback_keys_done));
sysfs_print(writeback_keys_failed,
atomic_long_read(&c->writeback_keys_failed));
if (attr == &sysfs_errors)
return bch_snprint_string_list(buf, PAGE_SIZE, error_actions,
c->on_error);
/* See count_io_errors for why 88 */
sysfs_print(io_error_halflife, c->error_decay * 88);
sysfs_print(io_error_limit, c->error_limit);
sysfs_hprint(congested,
((uint64_t) bch_get_congested(c)) << 9);
sysfs_print(congested_read_threshold_us,
c->congested_read_threshold_us);
sysfs_print(congested_write_threshold_us,
c->congested_write_threshold_us);
sysfs_print(cutoff_writeback, bch_cutoff_writeback);
sysfs_print(cutoff_writeback_sync, bch_cutoff_writeback_sync);
sysfs_print(active_journal_entries, fifo_used(&c->journal.pin));
sysfs_printf(verify, "%i", c->verify);
sysfs_printf(key_merging_disabled, "%i", c->key_merging_disabled);
sysfs_printf(expensive_debug_checks,
"%i", c->expensive_debug_checks);
sysfs_printf(gc_always_rewrite, "%i", c->gc_always_rewrite);
sysfs_printf(btree_shrinker_disabled, "%i", c->shrinker_disabled);
sysfs_printf(copy_gc_enabled, "%i", c->copy_gc_enabled);
sysfs_printf(idle_max_writeback_rate, "%i",
c->idle_max_writeback_rate_enabled);
sysfs_printf(gc_after_writeback, "%i", c->gc_after_writeback);
sysfs_printf(io_disable, "%i",
test_bit(CACHE_SET_IO_DISABLE, &c->flags));
if (attr == &sysfs_bset_tree_stats)
return bch_bset_print_stats(c, buf);
if (attr == &sysfs_feature_compat)
return bch_print_cache_set_feature_compat(c, buf, PAGE_SIZE);
if (attr == &sysfs_feature_ro_compat)
return bch_print_cache_set_feature_ro_compat(c, buf, PAGE_SIZE);
if (attr == &sysfs_feature_incompat)
return bch_print_cache_set_feature_incompat(c, buf, PAGE_SIZE);
return 0;
}
SHOW_LOCKED(bch_cache_set)
STORE(__bch_cache_set)
{
struct cache_set *c = container_of(kobj, struct cache_set, kobj);
ssize_t v;
/* no user space access if system is rebooting */
if (bcache_is_reboot)
return -EBUSY;
if (attr == &sysfs_unregister)
bch_cache_set_unregister(c);
if (attr == &sysfs_stop)
bch_cache_set_stop(c);
if (attr == &sysfs_synchronous) {
bool sync = strtoul_or_return(buf);
if (sync != CACHE_SYNC(&c->cache->sb)) {
SET_CACHE_SYNC(&c->cache->sb, sync);
bcache_write_super(c);
}
}
if (attr == &sysfs_flash_vol_create) {
int r;
uint64_t v;
strtoi_h_or_return(buf, v);
r = bch_flash_dev_create(c, v);
if (r)
return r;
}
if (attr == &sysfs_clear_stats) {
atomic_long_set(&c->writeback_keys_done, 0);
atomic_long_set(&c->writeback_keys_failed, 0);
memset(&c->gc_stats, 0, sizeof(struct gc_stat));
bch_cache_accounting_clear(&c->accounting);
}
if (attr == &sysfs_trigger_gc)
force_wake_up_gc(c);
if (attr == &sysfs_prune_cache) {
struct shrink_control sc;
sc.gfp_mask = GFP_KERNEL;
sc.nr_to_scan = strtoul_or_return(buf);
c->shrink.scan_objects(&c->shrink, &sc);
}
sysfs_strtoul_clamp(congested_read_threshold_us,
c->congested_read_threshold_us,
0, UINT_MAX);
sysfs_strtoul_clamp(congested_write_threshold_us,
c->congested_write_threshold_us,
0, UINT_MAX);
if (attr == &sysfs_errors) {
v = __sysfs_match_string(error_actions, -1, buf);
if (v < 0)
return v;
c->on_error = v;
}
sysfs_strtoul_clamp(io_error_limit, c->error_limit, 0, UINT_MAX);
/* See count_io_errors() for why 88 */
if (attr == &sysfs_io_error_halflife) {
unsigned long v = 0;
ssize_t ret;
ret = strtoul_safe_clamp(buf, v, 0, UINT_MAX);
if (!ret) {
c->error_decay = v / 88;
return size;
}
return ret;
}
if (attr == &sysfs_io_disable) {
v = strtoul_or_return(buf);
if (v) {
if (test_and_set_bit(CACHE_SET_IO_DISABLE,
&c->flags))
pr_warn("CACHE_SET_IO_DISABLE already set\n");
} else {
if (!test_and_clear_bit(CACHE_SET_IO_DISABLE,
&c->flags))
pr_warn("CACHE_SET_IO_DISABLE already cleared\n");
}
}
sysfs_strtoul_clamp(journal_delay_ms,
c->journal_delay_ms,
0, USHRT_MAX);
sysfs_strtoul_bool(verify, c->verify);
sysfs_strtoul_bool(key_merging_disabled, c->key_merging_disabled);
sysfs_strtoul(expensive_debug_checks, c->expensive_debug_checks);
sysfs_strtoul_bool(gc_always_rewrite, c->gc_always_rewrite);
sysfs_strtoul_bool(btree_shrinker_disabled, c->shrinker_disabled);
sysfs_strtoul_bool(copy_gc_enabled, c->copy_gc_enabled);
sysfs_strtoul_bool(idle_max_writeback_rate,
c->idle_max_writeback_rate_enabled);
/*
* write gc_after_writeback here may overwrite an already set
* BCH_DO_AUTO_GC, it doesn't matter because this flag will be
* set in next chance.
*/
sysfs_strtoul_clamp(gc_after_writeback, c->gc_after_writeback, 0, 1);
return size;
}
STORE_LOCKED(bch_cache_set)
SHOW(bch_cache_set_internal)
{
struct cache_set *c = container_of(kobj, struct cache_set, internal);
return bch_cache_set_show(&c->kobj, attr, buf);
}
STORE(bch_cache_set_internal)
{
struct cache_set *c = container_of(kobj, struct cache_set, internal);
/* no user space access if system is rebooting */
if (bcache_is_reboot)
return -EBUSY;
return bch_cache_set_store(&c->kobj, attr, buf, size);
}
static void bch_cache_set_internal_release(struct kobject *k)
{
}
static struct attribute *bch_cache_set_attrs[] = {
&sysfs_unregister,
&sysfs_stop,
&sysfs_synchronous,
&sysfs_journal_delay_ms,
&sysfs_flash_vol_create,
&sysfs_bucket_size,
&sysfs_block_size,
&sysfs_tree_depth,
&sysfs_root_usage_percent,
&sysfs_btree_cache_size,
&sysfs_cache_available_percent,
&sysfs_average_key_size,
&sysfs_errors,
&sysfs_io_error_limit,
&sysfs_io_error_halflife,
&sysfs_congested,
&sysfs_congested_read_threshold_us,
&sysfs_congested_write_threshold_us,
&sysfs_clear_stats,
NULL
};
ATTRIBUTE_GROUPS(bch_cache_set);
KTYPE(bch_cache_set);
static struct attribute *bch_cache_set_internal_attrs[] = {
&sysfs_active_journal_entries,
sysfs_time_stats_attribute_list(btree_gc, sec, ms)
sysfs_time_stats_attribute_list(btree_split, sec, us)
sysfs_time_stats_attribute_list(btree_sort, ms, us)
sysfs_time_stats_attribute_list(btree_read, ms, us)
&sysfs_btree_nodes,
&sysfs_btree_used_percent,
&sysfs_btree_cache_max_chain,
&sysfs_bset_tree_stats,
&sysfs_cache_read_races,
&sysfs_reclaim,
&sysfs_reclaimed_journal_buckets,
&sysfs_flush_write,
&sysfs_writeback_keys_done,
&sysfs_writeback_keys_failed,
&sysfs_trigger_gc,
&sysfs_prune_cache,
#ifdef CONFIG_BCACHE_DEBUG
&sysfs_verify,
&sysfs_key_merging_disabled,
&sysfs_expensive_debug_checks,
#endif
&sysfs_gc_always_rewrite,
&sysfs_btree_shrinker_disabled,
&sysfs_copy_gc_enabled,
&sysfs_idle_max_writeback_rate,
&sysfs_gc_after_writeback,
&sysfs_io_disable,
&sysfs_cutoff_writeback,
&sysfs_cutoff_writeback_sync,
&sysfs_feature_compat,
&sysfs_feature_ro_compat,
&sysfs_feature_incompat,
NULL
};
ATTRIBUTE_GROUPS(bch_cache_set_internal);
KTYPE(bch_cache_set_internal);
static int __bch_cache_cmp(const void *l, const void *r)
{
cond_resched();
return *((uint16_t *)r) - *((uint16_t *)l);
}
SHOW(__bch_cache)
{
struct cache *ca = container_of(kobj, struct cache, kobj);
sysfs_hprint(bucket_size, bucket_bytes(ca));
sysfs_hprint(block_size, block_bytes(ca));
sysfs_print(nbuckets, ca->sb.nbuckets);
sysfs_print(discard, ca->discard);
sysfs_hprint(written, atomic_long_read(&ca->sectors_written) << 9);
sysfs_hprint(btree_written,
atomic_long_read(&ca->btree_sectors_written) << 9);
sysfs_hprint(metadata_written,
(atomic_long_read(&ca->meta_sectors_written) +
atomic_long_read(&ca->btree_sectors_written)) << 9);
sysfs_print(io_errors,
atomic_read(&ca->io_errors) >> IO_ERROR_SHIFT);
if (attr == &sysfs_cache_replacement_policy)
return bch_snprint_string_list(buf, PAGE_SIZE,
cache_replacement_policies,
CACHE_REPLACEMENT(&ca->sb));
if (attr == &sysfs_priority_stats) {
struct bucket *b;
size_t n = ca->sb.nbuckets, i;
size_t unused = 0, available = 0, dirty = 0, meta = 0;
uint64_t sum = 0;
/* Compute 31 quantiles */
uint16_t q[31], *p, *cached;
ssize_t ret;
cached = p = vmalloc(array_size(sizeof(uint16_t),
ca->sb.nbuckets));
if (!p)
return -ENOMEM;
mutex_lock(&ca->set->bucket_lock);
for_each_bucket(b, ca) {
if (!GC_SECTORS_USED(b))
unused++;
if (GC_MARK(b) == GC_MARK_RECLAIMABLE)
available++;
if (GC_MARK(b) == GC_MARK_DIRTY)
dirty++;
if (GC_MARK(b) == GC_MARK_METADATA)
meta++;
}
for (i = ca->sb.first_bucket; i < n; i++)
p[i] = ca->buckets[i].prio;
mutex_unlock(&ca->set->bucket_lock);
sort(p, n, sizeof(uint16_t), __bch_cache_cmp, NULL);
while (n &&
!cached[n - 1])
--n;
while (cached < p + n &&
*cached == BTREE_PRIO) {
cached++;
n--;
}
for (i = 0; i < n; i++)
sum += INITIAL_PRIO - cached[i];
if (n)
do_div(sum, n);
for (i = 0; i < ARRAY_SIZE(q); i++)
q[i] = INITIAL_PRIO - cached[n * (i + 1) /
(ARRAY_SIZE(q) + 1)];
vfree(p);
ret = sysfs_emit(buf,
"Unused: %zu%%\n"
"Clean: %zu%%\n"
"Dirty: %zu%%\n"
"Metadata: %zu%%\n"
"Average: %llu\n"
"Sectors per Q: %zu\n"
"Quantiles: [",
unused * 100 / (size_t) ca->sb.nbuckets,
available * 100 / (size_t) ca->sb.nbuckets,
dirty * 100 / (size_t) ca->sb.nbuckets,
meta * 100 / (size_t) ca->sb.nbuckets, sum,
n * ca->sb.bucket_size / (ARRAY_SIZE(q) + 1));
for (i = 0; i < ARRAY_SIZE(q); i++)
ret += sysfs_emit_at(buf, ret, "%u ", q[i]);
ret--;
ret += sysfs_emit_at(buf, ret, "]\n");
return ret;
}
return 0;
}
SHOW_LOCKED(bch_cache)
STORE(__bch_cache)
{
struct cache *ca = container_of(kobj, struct cache, kobj);
ssize_t v;
/* no user space access if system is rebooting */
if (bcache_is_reboot)
return -EBUSY;
if (attr == &sysfs_discard) {
bool v = strtoul_or_return(buf);
if (bdev_max_discard_sectors(ca->bdev))
ca->discard = v;
if (v != CACHE_DISCARD(&ca->sb)) {
SET_CACHE_DISCARD(&ca->sb, v);
bcache_write_super(ca->set);
}
}
if (attr == &sysfs_cache_replacement_policy) {
v = __sysfs_match_string(cache_replacement_policies, -1, buf);
if (v < 0)
return v;
if ((unsigned int) v != CACHE_REPLACEMENT(&ca->sb)) {
mutex_lock(&ca->set->bucket_lock);
SET_CACHE_REPLACEMENT(&ca->sb, v);
mutex_unlock(&ca->set->bucket_lock);
bcache_write_super(ca->set);
}
}
if (attr == &sysfs_clear_stats) {
atomic_long_set(&ca->sectors_written, 0);
atomic_long_set(&ca->btree_sectors_written, 0);
atomic_long_set(&ca->meta_sectors_written, 0);
atomic_set(&ca->io_count, 0);
atomic_set(&ca->io_errors, 0);
}
return size;
}
STORE_LOCKED(bch_cache)
static struct attribute *bch_cache_attrs[] = {
&sysfs_bucket_size,
&sysfs_block_size,
&sysfs_nbuckets,
&sysfs_priority_stats,
&sysfs_discard,
&sysfs_written,
&sysfs_btree_written,
&sysfs_metadata_written,
&sysfs_io_errors,
&sysfs_clear_stats,
&sysfs_cache_replacement_policy,
NULL
};
ATTRIBUTE_GROUPS(bch_cache);
KTYPE(bch_cache);
| linux-master | drivers/md/bcache/sysfs.c |
// SPDX-License-Identifier: GPL-2.0
/*
* random utiility code, for bcache but in theory not specific to bcache
*
* Copyright 2010, 2011 Kent Overstreet <[email protected]>
* Copyright 2012 Google, Inc.
*/
#include <linux/bio.h>
#include <linux/blkdev.h>
#include <linux/ctype.h>
#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/types.h>
#include <linux/sched/clock.h>
#include "util.h"
#define simple_strtoint(c, end, base) simple_strtol(c, end, base)
#define simple_strtouint(c, end, base) simple_strtoul(c, end, base)
#define STRTO_H(name, type) \
int bch_ ## name ## _h(const char *cp, type *res) \
{ \
int u = 0; \
char *e; \
type i = simple_ ## name(cp, &e, 10); \
\
switch (tolower(*e)) { \
default: \
return -EINVAL; \
case 'y': \
case 'z': \
u++; \
fallthrough; \
case 'e': \
u++; \
fallthrough; \
case 'p': \
u++; \
fallthrough; \
case 't': \
u++; \
fallthrough; \
case 'g': \
u++; \
fallthrough; \
case 'm': \
u++; \
fallthrough; \
case 'k': \
u++; \
if (e++ == cp) \
return -EINVAL; \
fallthrough; \
case '\n': \
case '\0': \
if (*e == '\n') \
e++; \
} \
\
if (*e) \
return -EINVAL; \
\
while (u--) { \
if ((type) ~0 > 0 && \
(type) ~0 / 1024 <= i) \
return -EINVAL; \
if ((i > 0 && ANYSINT_MAX(type) / 1024 < i) || \
(i < 0 && -ANYSINT_MAX(type) / 1024 > i)) \
return -EINVAL; \
i *= 1024; \
} \
\
*res = i; \
return 0; \
} \
STRTO_H(strtoint, int)
STRTO_H(strtouint, unsigned int)
STRTO_H(strtoll, long long)
STRTO_H(strtoull, unsigned long long)
/**
* bch_hprint - formats @v to human readable string for sysfs.
* @buf: the (at least 8 byte) buffer to format the result into.
* @v: signed 64 bit integer
*
* Returns the number of bytes used by format.
*/
ssize_t bch_hprint(char *buf, int64_t v)
{
static const char units[] = "?kMGTPEZY";
int u = 0, t;
uint64_t q;
if (v < 0)
q = -v;
else
q = v;
/* For as long as the number is more than 3 digits, but at least
* once, shift right / divide by 1024. Keep the remainder for
* a digit after the decimal point.
*/
do {
u++;
t = q & ~(~0 << 10);
q >>= 10;
} while (q >= 1000);
if (v < 0)
/* '-', up to 3 digits, '.', 1 digit, 1 character, null;
* yields 8 bytes.
*/
return sprintf(buf, "-%llu.%i%c", q, t * 10 / 1024, units[u]);
else
return sprintf(buf, "%llu.%i%c", q, t * 10 / 1024, units[u]);
}
bool bch_is_zero(const char *p, size_t n)
{
size_t i;
for (i = 0; i < n; i++)
if (p[i])
return false;
return true;
}
int bch_parse_uuid(const char *s, char *uuid)
{
size_t i, j, x;
memset(uuid, 0, 16);
for (i = 0, j = 0;
i < strspn(s, "-0123456789:ABCDEFabcdef") && j < 32;
i++) {
x = s[i] | 32;
switch (x) {
case '0'...'9':
x -= '0';
break;
case 'a'...'f':
x -= 'a' - 10;
break;
default:
continue;
}
if (!(j & 1))
x <<= 4;
uuid[j++ >> 1] |= x;
}
return i;
}
void bch_time_stats_update(struct time_stats *stats, uint64_t start_time)
{
uint64_t now, duration, last;
spin_lock(&stats->lock);
now = local_clock();
duration = time_after64(now, start_time)
? now - start_time : 0;
last = time_after64(now, stats->last)
? now - stats->last : 0;
stats->max_duration = max(stats->max_duration, duration);
if (stats->last) {
ewma_add(stats->average_duration, duration, 8, 8);
if (stats->average_frequency)
ewma_add(stats->average_frequency, last, 8, 8);
else
stats->average_frequency = last << 8;
} else {
stats->average_duration = duration << 8;
}
stats->last = now ?: 1;
spin_unlock(&stats->lock);
}
/**
* bch_next_delay() - update ratelimiting statistics and calculate next delay
* @d: the struct bch_ratelimit to update
* @done: the amount of work done, in arbitrary units
*
* Increment @d by the amount of work done, and return how long to delay in
* jiffies until the next time to do some work.
*/
uint64_t bch_next_delay(struct bch_ratelimit *d, uint64_t done)
{
uint64_t now = local_clock();
d->next += div_u64(done * NSEC_PER_SEC, atomic_long_read(&d->rate));
/* Bound the time. Don't let us fall further than 2 seconds behind
* (this prevents unnecessary backlog that would make it impossible
* to catch up). If we're ahead of the desired writeback rate,
* don't let us sleep more than 2.5 seconds (so we can notice/respond
* if the control system tells us to speed up!).
*/
if (time_before64(now + NSEC_PER_SEC * 5LLU / 2LLU, d->next))
d->next = now + NSEC_PER_SEC * 5LLU / 2LLU;
if (time_after64(now - NSEC_PER_SEC * 2, d->next))
d->next = now - NSEC_PER_SEC * 2;
return time_after64(d->next, now)
? div_u64(d->next - now, NSEC_PER_SEC / HZ)
: 0;
}
/*
* Generally it isn't good to access .bi_io_vec and .bi_vcnt directly,
* the preferred way is bio_add_page, but in this case, bch_bio_map()
* supposes that the bvec table is empty, so it is safe to access
* .bi_vcnt & .bi_io_vec in this way even after multipage bvec is
* supported.
*/
void bch_bio_map(struct bio *bio, void *base)
{
size_t size = bio->bi_iter.bi_size;
struct bio_vec *bv = bio->bi_io_vec;
BUG_ON(!bio->bi_iter.bi_size);
BUG_ON(bio->bi_vcnt);
bv->bv_offset = base ? offset_in_page(base) : 0;
goto start;
for (; size; bio->bi_vcnt++, bv++) {
bv->bv_offset = 0;
start: bv->bv_len = min_t(size_t, PAGE_SIZE - bv->bv_offset,
size);
if (base) {
bv->bv_page = is_vmalloc_addr(base)
? vmalloc_to_page(base)
: virt_to_page(base);
base += bv->bv_len;
}
size -= bv->bv_len;
}
}
/**
* bch_bio_alloc_pages - allocates a single page for each bvec in a bio
* @bio: bio to allocate pages for
* @gfp_mask: flags for allocation
*
* Allocates pages up to @bio->bi_vcnt.
*
* Returns 0 on success, -ENOMEM on failure. On failure, any allocated pages are
* freed.
*/
int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp_mask)
{
int i;
struct bio_vec *bv;
/*
* This is called on freshly new bio, so it is safe to access the
* bvec table directly.
*/
for (i = 0, bv = bio->bi_io_vec; i < bio->bi_vcnt; bv++, i++) {
bv->bv_page = alloc_page(gfp_mask);
if (!bv->bv_page) {
while (--bv >= bio->bi_io_vec)
__free_page(bv->bv_page);
return -ENOMEM;
}
}
return 0;
}
| linux-master | drivers/md/bcache/util.c |
// SPDX-License-Identifier: GPL-2.0
/*
* Some low level IO code, and hacks for various block layer limitations
*
* Copyright 2010, 2011 Kent Overstreet <[email protected]>
* Copyright 2012 Google, Inc.
*/
#include "bcache.h"
#include "bset.h"
#include "debug.h"
#include <linux/blkdev.h>
/* Bios with headers */
void bch_bbio_free(struct bio *bio, struct cache_set *c)
{
struct bbio *b = container_of(bio, struct bbio, bio);
mempool_free(b, &c->bio_meta);
}
struct bio *bch_bbio_alloc(struct cache_set *c)
{
struct bbio *b = mempool_alloc(&c->bio_meta, GFP_NOIO);
struct bio *bio = &b->bio;
bio_init(bio, NULL, bio->bi_inline_vecs,
meta_bucket_pages(&c->cache->sb), 0);
return bio;
}
void __bch_submit_bbio(struct bio *bio, struct cache_set *c)
{
struct bbio *b = container_of(bio, struct bbio, bio);
bio->bi_iter.bi_sector = PTR_OFFSET(&b->key, 0);
bio_set_dev(bio, c->cache->bdev);
b->submit_time_us = local_clock_us();
closure_bio_submit(c, bio, bio->bi_private);
}
void bch_submit_bbio(struct bio *bio, struct cache_set *c,
struct bkey *k, unsigned int ptr)
{
struct bbio *b = container_of(bio, struct bbio, bio);
bch_bkey_copy_single_ptr(&b->key, k, ptr);
__bch_submit_bbio(bio, c);
}
/* IO errors */
void bch_count_backing_io_errors(struct cached_dev *dc, struct bio *bio)
{
unsigned int errors;
WARN_ONCE(!dc, "NULL pointer of struct cached_dev");
/*
* Read-ahead requests on a degrading and recovering md raid
* (e.g. raid6) device might be failured immediately by md
* raid code, which is not a real hardware media failure. So
* we shouldn't count failed REQ_RAHEAD bio to dc->io_errors.
*/
if (bio->bi_opf & REQ_RAHEAD) {
pr_warn_ratelimited("%pg: Read-ahead I/O failed on backing device, ignore\n",
dc->bdev);
return;
}
errors = atomic_add_return(1, &dc->io_errors);
if (errors < dc->error_limit)
pr_err("%pg: IO error on backing device, unrecoverable\n",
dc->bdev);
else
bch_cached_dev_error(dc);
}
void bch_count_io_errors(struct cache *ca,
blk_status_t error,
int is_read,
const char *m)
{
/*
* The halflife of an error is:
* log2(1/2)/log2(127/128) * refresh ~= 88 * refresh
*/
if (ca->set->error_decay) {
unsigned int count = atomic_inc_return(&ca->io_count);
while (count > ca->set->error_decay) {
unsigned int errors;
unsigned int old = count;
unsigned int new = count - ca->set->error_decay;
/*
* First we subtract refresh from count; each time we
* successfully do so, we rescale the errors once:
*/
count = atomic_cmpxchg(&ca->io_count, old, new);
if (count == old) {
count = new;
errors = atomic_read(&ca->io_errors);
do {
old = errors;
new = ((uint64_t) errors * 127) / 128;
errors = atomic_cmpxchg(&ca->io_errors,
old, new);
} while (old != errors);
}
}
}
if (error) {
unsigned int errors = atomic_add_return(1 << IO_ERROR_SHIFT,
&ca->io_errors);
errors >>= IO_ERROR_SHIFT;
if (errors < ca->set->error_limit)
pr_err("%pg: IO error on %s%s\n",
ca->bdev, m,
is_read ? ", recovering." : ".");
else
bch_cache_set_error(ca->set,
"%pg: too many IO errors %s\n",
ca->bdev, m);
}
}
void bch_bbio_count_io_errors(struct cache_set *c, struct bio *bio,
blk_status_t error, const char *m)
{
struct bbio *b = container_of(bio, struct bbio, bio);
struct cache *ca = c->cache;
int is_read = (bio_data_dir(bio) == READ ? 1 : 0);
unsigned int threshold = op_is_write(bio_op(bio))
? c->congested_write_threshold_us
: c->congested_read_threshold_us;
if (threshold) {
unsigned int t = local_clock_us();
int us = t - b->submit_time_us;
int congested = atomic_read(&c->congested);
if (us > (int) threshold) {
int ms = us / 1024;
c->congested_last_us = t;
ms = min(ms, CONGESTED_MAX + congested);
atomic_sub(ms, &c->congested);
} else if (congested < 0)
atomic_inc(&c->congested);
}
bch_count_io_errors(ca, error, is_read, m);
}
void bch_bbio_endio(struct cache_set *c, struct bio *bio,
blk_status_t error, const char *m)
{
struct closure *cl = bio->bi_private;
bch_bbio_count_io_errors(c, bio, error, m);
bio_put(bio);
closure_put(cl);
}
| linux-master | drivers/md/bcache/io.c |
// SPDX-License-Identifier: GPL-2.0
/*
* bcache journalling code, for btree insertions
*
* Copyright 2012 Google, Inc.
*/
#include "bcache.h"
#include "btree.h"
#include "debug.h"
#include "extents.h"
#include <trace/events/bcache.h>
/*
* Journal replay/recovery:
*
* This code is all driven from run_cache_set(); we first read the journal
* entries, do some other stuff, then we mark all the keys in the journal
* entries (same as garbage collection would), then we replay them - reinserting
* them into the cache in precisely the same order as they appear in the
* journal.
*
* We only journal keys that go in leaf nodes, which simplifies things quite a
* bit.
*/
static void journal_read_endio(struct bio *bio)
{
struct closure *cl = bio->bi_private;
closure_put(cl);
}
static int journal_read_bucket(struct cache *ca, struct list_head *list,
unsigned int bucket_index)
{
struct journal_device *ja = &ca->journal;
struct bio *bio = &ja->bio;
struct journal_replay *i;
struct jset *j, *data = ca->set->journal.w[0].data;
struct closure cl;
unsigned int len, left, offset = 0;
int ret = 0;
sector_t bucket = bucket_to_sector(ca->set, ca->sb.d[bucket_index]);
closure_init_stack(&cl);
pr_debug("reading %u\n", bucket_index);
while (offset < ca->sb.bucket_size) {
reread: left = ca->sb.bucket_size - offset;
len = min_t(unsigned int, left, PAGE_SECTORS << JSET_BITS);
bio_reset(bio, ca->bdev, REQ_OP_READ);
bio->bi_iter.bi_sector = bucket + offset;
bio->bi_iter.bi_size = len << 9;
bio->bi_end_io = journal_read_endio;
bio->bi_private = &cl;
bch_bio_map(bio, data);
closure_bio_submit(ca->set, bio, &cl);
closure_sync(&cl);
/* This function could be simpler now since we no longer write
* journal entries that overlap bucket boundaries; this means
* the start of a bucket will always have a valid journal entry
* if it has any journal entries at all.
*/
j = data;
while (len) {
struct list_head *where;
size_t blocks, bytes = set_bytes(j);
if (j->magic != jset_magic(&ca->sb)) {
pr_debug("%u: bad magic\n", bucket_index);
return ret;
}
if (bytes > left << 9 ||
bytes > PAGE_SIZE << JSET_BITS) {
pr_info("%u: too big, %zu bytes, offset %u\n",
bucket_index, bytes, offset);
return ret;
}
if (bytes > len << 9)
goto reread;
if (j->csum != csum_set(j)) {
pr_info("%u: bad csum, %zu bytes, offset %u\n",
bucket_index, bytes, offset);
return ret;
}
blocks = set_blocks(j, block_bytes(ca));
/*
* Nodes in 'list' are in linear increasing order of
* i->j.seq, the node on head has the smallest (oldest)
* journal seq, the node on tail has the biggest
* (latest) journal seq.
*/
/*
* Check from the oldest jset for last_seq. If
* i->j.seq < j->last_seq, it means the oldest jset
* in list is expired and useless, remove it from
* this list. Otherwise, j is a candidate jset for
* further following checks.
*/
while (!list_empty(list)) {
i = list_first_entry(list,
struct journal_replay, list);
if (i->j.seq >= j->last_seq)
break;
list_del(&i->list);
kfree(i);
}
/* iterate list in reverse order (from latest jset) */
list_for_each_entry_reverse(i, list, list) {
if (j->seq == i->j.seq)
goto next_set;
/*
* if j->seq is less than any i->j.last_seq
* in list, j is an expired and useless jset.
*/
if (j->seq < i->j.last_seq)
goto next_set;
/*
* 'where' points to first jset in list which
* is elder then j.
*/
if (j->seq > i->j.seq) {
where = &i->list;
goto add;
}
}
where = list;
add:
i = kmalloc(offsetof(struct journal_replay, j) +
bytes, GFP_KERNEL);
if (!i)
return -ENOMEM;
unsafe_memcpy(&i->j, j, bytes,
/* "bytes" was calculated by set_bytes() above */);
/* Add to the location after 'where' points to */
list_add(&i->list, where);
ret = 1;
if (j->seq > ja->seq[bucket_index])
ja->seq[bucket_index] = j->seq;
next_set:
offset += blocks * ca->sb.block_size;
len -= blocks * ca->sb.block_size;
j = ((void *) j) + blocks * block_bytes(ca);
}
}
return ret;
}
int bch_journal_read(struct cache_set *c, struct list_head *list)
{
#define read_bucket(b) \
({ \
ret = journal_read_bucket(ca, list, b); \
__set_bit(b, bitmap); \
if (ret < 0) \
return ret; \
ret; \
})
struct cache *ca = c->cache;
int ret = 0;
struct journal_device *ja = &ca->journal;
DECLARE_BITMAP(bitmap, SB_JOURNAL_BUCKETS);
unsigned int i, l, r, m;
uint64_t seq;
bitmap_zero(bitmap, SB_JOURNAL_BUCKETS);
pr_debug("%u journal buckets\n", ca->sb.njournal_buckets);
/*
* Read journal buckets ordered by golden ratio hash to quickly
* find a sequence of buckets with valid journal entries
*/
for (i = 0; i < ca->sb.njournal_buckets; i++) {
/*
* We must try the index l with ZERO first for
* correctness due to the scenario that the journal
* bucket is circular buffer which might have wrapped
*/
l = (i * 2654435769U) % ca->sb.njournal_buckets;
if (test_bit(l, bitmap))
break;
if (read_bucket(l))
goto bsearch;
}
/*
* If that fails, check all the buckets we haven't checked
* already
*/
pr_debug("falling back to linear search\n");
for_each_clear_bit(l, bitmap, ca->sb.njournal_buckets)
if (read_bucket(l))
goto bsearch;
/* no journal entries on this device? */
if (l == ca->sb.njournal_buckets)
goto out;
bsearch:
BUG_ON(list_empty(list));
/* Binary search */
m = l;
r = find_next_bit(bitmap, ca->sb.njournal_buckets, l + 1);
pr_debug("starting binary search, l %u r %u\n", l, r);
while (l + 1 < r) {
seq = list_entry(list->prev, struct journal_replay,
list)->j.seq;
m = (l + r) >> 1;
read_bucket(m);
if (seq != list_entry(list->prev, struct journal_replay,
list)->j.seq)
l = m;
else
r = m;
}
/*
* Read buckets in reverse order until we stop finding more
* journal entries
*/
pr_debug("finishing up: m %u njournal_buckets %u\n",
m, ca->sb.njournal_buckets);
l = m;
while (1) {
if (!l--)
l = ca->sb.njournal_buckets - 1;
if (l == m)
break;
if (test_bit(l, bitmap))
continue;
if (!read_bucket(l))
break;
}
seq = 0;
for (i = 0; i < ca->sb.njournal_buckets; i++)
if (ja->seq[i] > seq) {
seq = ja->seq[i];
/*
* When journal_reclaim() goes to allocate for
* the first time, it'll use the bucket after
* ja->cur_idx
*/
ja->cur_idx = i;
ja->last_idx = ja->discard_idx = (i + 1) %
ca->sb.njournal_buckets;
}
out:
if (!list_empty(list))
c->journal.seq = list_entry(list->prev,
struct journal_replay,
list)->j.seq;
return 0;
#undef read_bucket
}
void bch_journal_mark(struct cache_set *c, struct list_head *list)
{
atomic_t p = { 0 };
struct bkey *k;
struct journal_replay *i;
struct journal *j = &c->journal;
uint64_t last = j->seq;
/*
* journal.pin should never fill up - we never write a journal
* entry when it would fill up. But if for some reason it does, we
* iterate over the list in reverse order so that we can just skip that
* refcount instead of bugging.
*/
list_for_each_entry_reverse(i, list, list) {
BUG_ON(last < i->j.seq);
i->pin = NULL;
while (last-- != i->j.seq)
if (fifo_free(&j->pin) > 1) {
fifo_push_front(&j->pin, p);
atomic_set(&fifo_front(&j->pin), 0);
}
if (fifo_free(&j->pin) > 1) {
fifo_push_front(&j->pin, p);
i->pin = &fifo_front(&j->pin);
atomic_set(i->pin, 1);
}
for (k = i->j.start;
k < bset_bkey_last(&i->j);
k = bkey_next(k))
if (!__bch_extent_invalid(c, k)) {
unsigned int j;
for (j = 0; j < KEY_PTRS(k); j++)
if (ptr_available(c, k, j))
atomic_inc(&PTR_BUCKET(c, k, j)->pin);
bch_initial_mark_key(c, 0, k);
}
}
}
static bool is_discard_enabled(struct cache_set *s)
{
struct cache *ca = s->cache;
if (ca->discard)
return true;
return false;
}
int bch_journal_replay(struct cache_set *s, struct list_head *list)
{
int ret = 0, keys = 0, entries = 0;
struct bkey *k;
struct journal_replay *i =
list_entry(list->prev, struct journal_replay, list);
uint64_t start = i->j.last_seq, end = i->j.seq, n = start;
struct keylist keylist;
list_for_each_entry(i, list, list) {
BUG_ON(i->pin && atomic_read(i->pin) != 1);
if (n != i->j.seq) {
if (n == start && is_discard_enabled(s))
pr_info("journal entries %llu-%llu may be discarded! (replaying %llu-%llu)\n",
n, i->j.seq - 1, start, end);
else {
pr_err("journal entries %llu-%llu missing! (replaying %llu-%llu)\n",
n, i->j.seq - 1, start, end);
ret = -EIO;
goto err;
}
}
for (k = i->j.start;
k < bset_bkey_last(&i->j);
k = bkey_next(k)) {
trace_bcache_journal_replay_key(k);
bch_keylist_init_single(&keylist, k);
ret = bch_btree_insert(s, &keylist, i->pin, NULL);
if (ret)
goto err;
BUG_ON(!bch_keylist_empty(&keylist));
keys++;
cond_resched();
}
if (i->pin)
atomic_dec(i->pin);
n = i->j.seq + 1;
entries++;
}
pr_info("journal replay done, %i keys in %i entries, seq %llu\n",
keys, entries, end);
err:
while (!list_empty(list)) {
i = list_first_entry(list, struct journal_replay, list);
list_del(&i->list);
kfree(i);
}
return ret;
}
void bch_journal_space_reserve(struct journal *j)
{
j->do_reserve = true;
}
/* Journalling */
static void btree_flush_write(struct cache_set *c)
{
struct btree *b, *t, *btree_nodes[BTREE_FLUSH_NR];
unsigned int i, nr;
int ref_nr;
atomic_t *fifo_front_p, *now_fifo_front_p;
size_t mask;
if (c->journal.btree_flushing)
return;
spin_lock(&c->journal.flush_write_lock);
if (c->journal.btree_flushing) {
spin_unlock(&c->journal.flush_write_lock);
return;
}
c->journal.btree_flushing = true;
spin_unlock(&c->journal.flush_write_lock);
/* get the oldest journal entry and check its refcount */
spin_lock(&c->journal.lock);
fifo_front_p = &fifo_front(&c->journal.pin);
ref_nr = atomic_read(fifo_front_p);
if (ref_nr <= 0) {
/*
* do nothing if no btree node references
* the oldest journal entry
*/
spin_unlock(&c->journal.lock);
goto out;
}
spin_unlock(&c->journal.lock);
mask = c->journal.pin.mask;
nr = 0;
atomic_long_inc(&c->flush_write);
memset(btree_nodes, 0, sizeof(btree_nodes));
mutex_lock(&c->bucket_lock);
list_for_each_entry_safe_reverse(b, t, &c->btree_cache, list) {
/*
* It is safe to get now_fifo_front_p without holding
* c->journal.lock here, because we don't need to know
* the exactly accurate value, just check whether the
* front pointer of c->journal.pin is changed.
*/
now_fifo_front_p = &fifo_front(&c->journal.pin);
/*
* If the oldest journal entry is reclaimed and front
* pointer of c->journal.pin changes, it is unnecessary
* to scan c->btree_cache anymore, just quit the loop and
* flush out what we have already.
*/
if (now_fifo_front_p != fifo_front_p)
break;
/*
* quit this loop if all matching btree nodes are
* scanned and record in btree_nodes[] already.
*/
ref_nr = atomic_read(fifo_front_p);
if (nr >= ref_nr)
break;
if (btree_node_journal_flush(b))
pr_err("BUG: flush_write bit should not be set here!\n");
mutex_lock(&b->write_lock);
if (!btree_node_dirty(b)) {
mutex_unlock(&b->write_lock);
continue;
}
if (!btree_current_write(b)->journal) {
mutex_unlock(&b->write_lock);
continue;
}
/*
* Only select the btree node which exactly references
* the oldest journal entry.
*
* If the journal entry pointed by fifo_front_p is
* reclaimed in parallel, don't worry:
* - the list_for_each_xxx loop will quit when checking
* next now_fifo_front_p.
* - If there are matched nodes recorded in btree_nodes[],
* they are clean now (this is why and how the oldest
* journal entry can be reclaimed). These selected nodes
* will be ignored and skipped in the following for-loop.
*/
if (((btree_current_write(b)->journal - fifo_front_p) &
mask) != 0) {
mutex_unlock(&b->write_lock);
continue;
}
set_btree_node_journal_flush(b);
mutex_unlock(&b->write_lock);
btree_nodes[nr++] = b;
/*
* To avoid holding c->bucket_lock too long time,
* only scan for BTREE_FLUSH_NR matched btree nodes
* at most. If there are more btree nodes reference
* the oldest journal entry, try to flush them next
* time when btree_flush_write() is called.
*/
if (nr == BTREE_FLUSH_NR)
break;
}
mutex_unlock(&c->bucket_lock);
for (i = 0; i < nr; i++) {
b = btree_nodes[i];
if (!b) {
pr_err("BUG: btree_nodes[%d] is NULL\n", i);
continue;
}
/* safe to check without holding b->write_lock */
if (!btree_node_journal_flush(b)) {
pr_err("BUG: bnode %p: journal_flush bit cleaned\n", b);
continue;
}
mutex_lock(&b->write_lock);
if (!btree_current_write(b)->journal) {
clear_bit(BTREE_NODE_journal_flush, &b->flags);
mutex_unlock(&b->write_lock);
pr_debug("bnode %p: written by others\n", b);
continue;
}
if (!btree_node_dirty(b)) {
clear_bit(BTREE_NODE_journal_flush, &b->flags);
mutex_unlock(&b->write_lock);
pr_debug("bnode %p: dirty bit cleaned by others\n", b);
continue;
}
__bch_btree_node_write(b, NULL);
clear_bit(BTREE_NODE_journal_flush, &b->flags);
mutex_unlock(&b->write_lock);
}
out:
spin_lock(&c->journal.flush_write_lock);
c->journal.btree_flushing = false;
spin_unlock(&c->journal.flush_write_lock);
}
#define last_seq(j) ((j)->seq - fifo_used(&(j)->pin) + 1)
static void journal_discard_endio(struct bio *bio)
{
struct journal_device *ja =
container_of(bio, struct journal_device, discard_bio);
struct cache *ca = container_of(ja, struct cache, journal);
atomic_set(&ja->discard_in_flight, DISCARD_DONE);
closure_wake_up(&ca->set->journal.wait);
closure_put(&ca->set->cl);
}
static void journal_discard_work(struct work_struct *work)
{
struct journal_device *ja =
container_of(work, struct journal_device, discard_work);
submit_bio(&ja->discard_bio);
}
static void do_journal_discard(struct cache *ca)
{
struct journal_device *ja = &ca->journal;
struct bio *bio = &ja->discard_bio;
if (!ca->discard) {
ja->discard_idx = ja->last_idx;
return;
}
switch (atomic_read(&ja->discard_in_flight)) {
case DISCARD_IN_FLIGHT:
return;
case DISCARD_DONE:
ja->discard_idx = (ja->discard_idx + 1) %
ca->sb.njournal_buckets;
atomic_set(&ja->discard_in_flight, DISCARD_READY);
fallthrough;
case DISCARD_READY:
if (ja->discard_idx == ja->last_idx)
return;
atomic_set(&ja->discard_in_flight, DISCARD_IN_FLIGHT);
bio_init(bio, ca->bdev, bio->bi_inline_vecs, 1, REQ_OP_DISCARD);
bio->bi_iter.bi_sector = bucket_to_sector(ca->set,
ca->sb.d[ja->discard_idx]);
bio->bi_iter.bi_size = bucket_bytes(ca);
bio->bi_end_io = journal_discard_endio;
closure_get(&ca->set->cl);
INIT_WORK(&ja->discard_work, journal_discard_work);
queue_work(bch_journal_wq, &ja->discard_work);
}
}
static unsigned int free_journal_buckets(struct cache_set *c)
{
struct journal *j = &c->journal;
struct cache *ca = c->cache;
struct journal_device *ja = &c->cache->journal;
unsigned int n;
/* In case njournal_buckets is not power of 2 */
if (ja->cur_idx >= ja->discard_idx)
n = ca->sb.njournal_buckets + ja->discard_idx - ja->cur_idx;
else
n = ja->discard_idx - ja->cur_idx;
if (n > (1 + j->do_reserve))
return n - (1 + j->do_reserve);
return 0;
}
static void journal_reclaim(struct cache_set *c)
{
struct bkey *k = &c->journal.key;
struct cache *ca = c->cache;
uint64_t last_seq;
struct journal_device *ja = &ca->journal;
atomic_t p __maybe_unused;
atomic_long_inc(&c->reclaim);
while (!atomic_read(&fifo_front(&c->journal.pin)))
fifo_pop(&c->journal.pin, p);
last_seq = last_seq(&c->journal);
/* Update last_idx */
while (ja->last_idx != ja->cur_idx &&
ja->seq[ja->last_idx] < last_seq)
ja->last_idx = (ja->last_idx + 1) %
ca->sb.njournal_buckets;
do_journal_discard(ca);
if (c->journal.blocks_free)
goto out;
if (!free_journal_buckets(c))
goto out;
ja->cur_idx = (ja->cur_idx + 1) % ca->sb.njournal_buckets;
k->ptr[0] = MAKE_PTR(0,
bucket_to_sector(c, ca->sb.d[ja->cur_idx]),
ca->sb.nr_this_dev);
atomic_long_inc(&c->reclaimed_journal_buckets);
bkey_init(k);
SET_KEY_PTRS(k, 1);
c->journal.blocks_free = ca->sb.bucket_size >> c->block_bits;
out:
if (!journal_full(&c->journal))
__closure_wake_up(&c->journal.wait);
}
void bch_journal_next(struct journal *j)
{
atomic_t p = { 1 };
j->cur = (j->cur == j->w)
? &j->w[1]
: &j->w[0];
/*
* The fifo_push() needs to happen at the same time as j->seq is
* incremented for last_seq() to be calculated correctly
*/
BUG_ON(!fifo_push(&j->pin, p));
atomic_set(&fifo_back(&j->pin), 1);
j->cur->data->seq = ++j->seq;
j->cur->dirty = false;
j->cur->need_write = false;
j->cur->data->keys = 0;
if (fifo_full(&j->pin))
pr_debug("journal_pin full (%zu)\n", fifo_used(&j->pin));
}
static void journal_write_endio(struct bio *bio)
{
struct journal_write *w = bio->bi_private;
cache_set_err_on(bio->bi_status, w->c, "journal io error");
closure_put(&w->c->journal.io);
}
static void journal_write(struct closure *cl);
static void journal_write_done(struct closure *cl)
{
struct journal *j = container_of(cl, struct journal, io);
struct journal_write *w = (j->cur == j->w)
? &j->w[1]
: &j->w[0];
__closure_wake_up(&w->wait);
continue_at_nobarrier(cl, journal_write, bch_journal_wq);
}
static void journal_write_unlock(struct closure *cl)
__releases(&c->journal.lock)
{
struct cache_set *c = container_of(cl, struct cache_set, journal.io);
c->journal.io_in_flight = 0;
spin_unlock(&c->journal.lock);
}
static void journal_write_unlocked(struct closure *cl)
__releases(c->journal.lock)
{
struct cache_set *c = container_of(cl, struct cache_set, journal.io);
struct cache *ca = c->cache;
struct journal_write *w = c->journal.cur;
struct bkey *k = &c->journal.key;
unsigned int i, sectors = set_blocks(w->data, block_bytes(ca)) *
ca->sb.block_size;
struct bio *bio;
struct bio_list list;
bio_list_init(&list);
if (!w->need_write) {
closure_return_with_destructor(cl, journal_write_unlock);
return;
} else if (journal_full(&c->journal)) {
journal_reclaim(c);
spin_unlock(&c->journal.lock);
btree_flush_write(c);
continue_at(cl, journal_write, bch_journal_wq);
return;
}
c->journal.blocks_free -= set_blocks(w->data, block_bytes(ca));
w->data->btree_level = c->root->level;
bkey_copy(&w->data->btree_root, &c->root->key);
bkey_copy(&w->data->uuid_bucket, &c->uuid_bucket);
w->data->prio_bucket[ca->sb.nr_this_dev] = ca->prio_buckets[0];
w->data->magic = jset_magic(&ca->sb);
w->data->version = BCACHE_JSET_VERSION;
w->data->last_seq = last_seq(&c->journal);
w->data->csum = csum_set(w->data);
for (i = 0; i < KEY_PTRS(k); i++) {
ca = c->cache;
bio = &ca->journal.bio;
atomic_long_add(sectors, &ca->meta_sectors_written);
bio_reset(bio, ca->bdev, REQ_OP_WRITE |
REQ_SYNC | REQ_META | REQ_PREFLUSH | REQ_FUA);
bio->bi_iter.bi_sector = PTR_OFFSET(k, i);
bio->bi_iter.bi_size = sectors << 9;
bio->bi_end_io = journal_write_endio;
bio->bi_private = w;
bch_bio_map(bio, w->data);
trace_bcache_journal_write(bio, w->data->keys);
bio_list_add(&list, bio);
SET_PTR_OFFSET(k, i, PTR_OFFSET(k, i) + sectors);
ca->journal.seq[ca->journal.cur_idx] = w->data->seq;
}
/* If KEY_PTRS(k) == 0, this jset gets lost in air */
BUG_ON(i == 0);
atomic_dec_bug(&fifo_back(&c->journal.pin));
bch_journal_next(&c->journal);
journal_reclaim(c);
spin_unlock(&c->journal.lock);
while ((bio = bio_list_pop(&list)))
closure_bio_submit(c, bio, cl);
continue_at(cl, journal_write_done, NULL);
}
static void journal_write(struct closure *cl)
{
struct cache_set *c = container_of(cl, struct cache_set, journal.io);
spin_lock(&c->journal.lock);
journal_write_unlocked(cl);
}
static void journal_try_write(struct cache_set *c)
__releases(c->journal.lock)
{
struct closure *cl = &c->journal.io;
struct journal_write *w = c->journal.cur;
w->need_write = true;
if (!c->journal.io_in_flight) {
c->journal.io_in_flight = 1;
closure_call(cl, journal_write_unlocked, NULL, &c->cl);
} else {
spin_unlock(&c->journal.lock);
}
}
static struct journal_write *journal_wait_for_write(struct cache_set *c,
unsigned int nkeys)
__acquires(&c->journal.lock)
{
size_t sectors;
struct closure cl;
bool wait = false;
struct cache *ca = c->cache;
closure_init_stack(&cl);
spin_lock(&c->journal.lock);
while (1) {
struct journal_write *w = c->journal.cur;
sectors = __set_blocks(w->data, w->data->keys + nkeys,
block_bytes(ca)) * ca->sb.block_size;
if (sectors <= min_t(size_t,
c->journal.blocks_free * ca->sb.block_size,
PAGE_SECTORS << JSET_BITS))
return w;
if (wait)
closure_wait(&c->journal.wait, &cl);
if (!journal_full(&c->journal)) {
if (wait)
trace_bcache_journal_entry_full(c);
/*
* XXX: If we were inserting so many keys that they
* won't fit in an _empty_ journal write, we'll
* deadlock. For now, handle this in
* bch_keylist_realloc() - but something to think about.
*/
BUG_ON(!w->data->keys);
journal_try_write(c); /* unlocks */
} else {
if (wait)
trace_bcache_journal_full(c);
journal_reclaim(c);
spin_unlock(&c->journal.lock);
btree_flush_write(c);
}
closure_sync(&cl);
spin_lock(&c->journal.lock);
wait = true;
}
}
static void journal_write_work(struct work_struct *work)
{
struct cache_set *c = container_of(to_delayed_work(work),
struct cache_set,
journal.work);
spin_lock(&c->journal.lock);
if (c->journal.cur->dirty)
journal_try_write(c);
else
spin_unlock(&c->journal.lock);
}
/*
* Entry point to the journalling code - bio_insert() and btree_invalidate()
* pass bch_journal() a list of keys to be journalled, and then
* bch_journal() hands those same keys off to btree_insert_async()
*/
atomic_t *bch_journal(struct cache_set *c,
struct keylist *keys,
struct closure *parent)
{
struct journal_write *w;
atomic_t *ret;
/* No journaling if CACHE_SET_IO_DISABLE set already */
if (unlikely(test_bit(CACHE_SET_IO_DISABLE, &c->flags)))
return NULL;
if (!CACHE_SYNC(&c->cache->sb))
return NULL;
w = journal_wait_for_write(c, bch_keylist_nkeys(keys));
memcpy(bset_bkey_last(w->data), keys->keys, bch_keylist_bytes(keys));
w->data->keys += bch_keylist_nkeys(keys);
ret = &fifo_back(&c->journal.pin);
atomic_inc(ret);
if (parent) {
closure_wait(&w->wait, parent);
journal_try_write(c);
} else if (!w->dirty) {
w->dirty = true;
queue_delayed_work(bch_flush_wq, &c->journal.work,
msecs_to_jiffies(c->journal_delay_ms));
spin_unlock(&c->journal.lock);
} else {
spin_unlock(&c->journal.lock);
}
return ret;
}
void bch_journal_meta(struct cache_set *c, struct closure *cl)
{
struct keylist keys;
atomic_t *ref;
bch_keylist_init(&keys);
ref = bch_journal(c, &keys, cl);
if (ref)
atomic_dec_bug(ref);
}
void bch_journal_free(struct cache_set *c)
{
free_pages((unsigned long) c->journal.w[1].data, JSET_BITS);
free_pages((unsigned long) c->journal.w[0].data, JSET_BITS);
free_fifo(&c->journal.pin);
}
int bch_journal_alloc(struct cache_set *c)
{
struct journal *j = &c->journal;
spin_lock_init(&j->lock);
spin_lock_init(&j->flush_write_lock);
INIT_DELAYED_WORK(&j->work, journal_write_work);
c->journal_delay_ms = 100;
j->w[0].c = c;
j->w[1].c = c;
if (!(init_fifo(&j->pin, JOURNAL_PIN, GFP_KERNEL)) ||
!(j->w[0].data = (void *) __get_free_pages(GFP_KERNEL|__GFP_COMP, JSET_BITS)) ||
!(j->w[1].data = (void *) __get_free_pages(GFP_KERNEL|__GFP_COMP, JSET_BITS)))
return -ENOMEM;
return 0;
}
| linux-master | drivers/md/bcache/journal.c |
// SPDX-License-Identifier: GPL-2.0
/*
* Asynchronous refcounty things
*
* Copyright 2010, 2011 Kent Overstreet <[email protected]>
* Copyright 2012 Google, Inc.
*/
#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/sched/debug.h>
#include "closure.h"
static inline void closure_put_after_sub(struct closure *cl, int flags)
{
int r = flags & CLOSURE_REMAINING_MASK;
BUG_ON(flags & CLOSURE_GUARD_MASK);
BUG_ON(!r && (flags & ~CLOSURE_DESTRUCTOR));
if (!r) {
if (cl->fn && !(flags & CLOSURE_DESTRUCTOR)) {
atomic_set(&cl->remaining,
CLOSURE_REMAINING_INITIALIZER);
closure_queue(cl);
} else {
struct closure *parent = cl->parent;
closure_fn *destructor = cl->fn;
closure_debug_destroy(cl);
if (destructor)
destructor(cl);
if (parent)
closure_put(parent);
}
}
}
/* For clearing flags with the same atomic op as a put */
void closure_sub(struct closure *cl, int v)
{
closure_put_after_sub(cl, atomic_sub_return(v, &cl->remaining));
}
/*
* closure_put - decrement a closure's refcount
*/
void closure_put(struct closure *cl)
{
closure_put_after_sub(cl, atomic_dec_return(&cl->remaining));
}
/*
* closure_wake_up - wake up all closures on a wait list, without memory barrier
*/
void __closure_wake_up(struct closure_waitlist *wait_list)
{
struct llist_node *list;
struct closure *cl, *t;
struct llist_node *reverse = NULL;
list = llist_del_all(&wait_list->list);
/* We first reverse the list to preserve FIFO ordering and fairness */
reverse = llist_reverse_order(list);
/* Then do the wakeups */
llist_for_each_entry_safe(cl, t, reverse, list) {
closure_set_waiting(cl, 0);
closure_sub(cl, CLOSURE_WAITING + 1);
}
}
/**
* closure_wait - add a closure to a waitlist
* @waitlist: will own a ref on @cl, which will be released when
* closure_wake_up() is called on @waitlist.
* @cl: closure pointer.
*
*/
bool closure_wait(struct closure_waitlist *waitlist, struct closure *cl)
{
if (atomic_read(&cl->remaining) & CLOSURE_WAITING)
return false;
closure_set_waiting(cl, _RET_IP_);
atomic_add(CLOSURE_WAITING + 1, &cl->remaining);
llist_add(&cl->list, &waitlist->list);
return true;
}
struct closure_syncer {
struct task_struct *task;
int done;
};
static void closure_sync_fn(struct closure *cl)
{
struct closure_syncer *s = cl->s;
struct task_struct *p;
rcu_read_lock();
p = READ_ONCE(s->task);
s->done = 1;
wake_up_process(p);
rcu_read_unlock();
}
void __sched __closure_sync(struct closure *cl)
{
struct closure_syncer s = { .task = current };
cl->s = &s;
continue_at(cl, closure_sync_fn, NULL);
while (1) {
set_current_state(TASK_UNINTERRUPTIBLE);
if (s.done)
break;
schedule();
}
__set_current_state(TASK_RUNNING);
}
#ifdef CONFIG_BCACHE_CLOSURES_DEBUG
static LIST_HEAD(closure_list);
static DEFINE_SPINLOCK(closure_list_lock);
void closure_debug_create(struct closure *cl)
{
unsigned long flags;
BUG_ON(cl->magic == CLOSURE_MAGIC_ALIVE);
cl->magic = CLOSURE_MAGIC_ALIVE;
spin_lock_irqsave(&closure_list_lock, flags);
list_add(&cl->all, &closure_list);
spin_unlock_irqrestore(&closure_list_lock, flags);
}
void closure_debug_destroy(struct closure *cl)
{
unsigned long flags;
BUG_ON(cl->magic != CLOSURE_MAGIC_ALIVE);
cl->magic = CLOSURE_MAGIC_DEAD;
spin_lock_irqsave(&closure_list_lock, flags);
list_del(&cl->all);
spin_unlock_irqrestore(&closure_list_lock, flags);
}
static struct dentry *closure_debug;
static int debug_show(struct seq_file *f, void *data)
{
struct closure *cl;
spin_lock_irq(&closure_list_lock);
list_for_each_entry(cl, &closure_list, all) {
int r = atomic_read(&cl->remaining);
seq_printf(f, "%p: %pS -> %pS p %p r %i ",
cl, (void *) cl->ip, cl->fn, cl->parent,
r & CLOSURE_REMAINING_MASK);
seq_printf(f, "%s%s\n",
test_bit(WORK_STRUCT_PENDING_BIT,
work_data_bits(&cl->work)) ? "Q" : "",
r & CLOSURE_RUNNING ? "R" : "");
if (r & CLOSURE_WAITING)
seq_printf(f, " W %pS\n",
(void *) cl->waiting_on);
seq_printf(f, "\n");
}
spin_unlock_irq(&closure_list_lock);
return 0;
}
DEFINE_SHOW_ATTRIBUTE(debug);
void __init closure_debug_init(void)
{
if (!IS_ERR_OR_NULL(bcache_debug))
/*
* it is unnecessary to check return value of
* debugfs_create_file(), we should not care
* about this.
*/
closure_debug = debugfs_create_file(
"closures", 0400, bcache_debug, NULL, &debug_fops);
}
#endif
MODULE_AUTHOR("Kent Overstreet <[email protected]>");
MODULE_LICENSE("GPL");
| linux-master | drivers/md/bcache/closure.c |
// SPDX-License-Identifier: GPL-2.0
/*
* Code for working with individual keys, and sorted sets of keys with in a
* btree node
*
* Copyright 2012 Google, Inc.
*/
#define pr_fmt(fmt) "bcache: %s() " fmt, __func__
#include "util.h"
#include "bset.h"
#include <linux/console.h>
#include <linux/sched/clock.h>
#include <linux/random.h>
#include <linux/prefetch.h>
#ifdef CONFIG_BCACHE_DEBUG
void bch_dump_bset(struct btree_keys *b, struct bset *i, unsigned int set)
{
struct bkey *k, *next;
for (k = i->start; k < bset_bkey_last(i); k = next) {
next = bkey_next(k);
pr_err("block %u key %u/%u: ", set,
(unsigned int) ((u64 *) k - i->d), i->keys);
if (b->ops->key_dump)
b->ops->key_dump(b, k);
else
pr_cont("%llu:%llu\n", KEY_INODE(k), KEY_OFFSET(k));
if (next < bset_bkey_last(i) &&
bkey_cmp(k, b->ops->is_extents ?
&START_KEY(next) : next) > 0)
pr_err("Key skipped backwards\n");
}
}
void bch_dump_bucket(struct btree_keys *b)
{
unsigned int i;
console_lock();
for (i = 0; i <= b->nsets; i++)
bch_dump_bset(b, b->set[i].data,
bset_sector_offset(b, b->set[i].data));
console_unlock();
}
int __bch_count_data(struct btree_keys *b)
{
unsigned int ret = 0;
struct btree_iter iter;
struct bkey *k;
if (b->ops->is_extents)
for_each_key(b, k, &iter)
ret += KEY_SIZE(k);
return ret;
}
void __bch_check_keys(struct btree_keys *b, const char *fmt, ...)
{
va_list args;
struct bkey *k, *p = NULL;
struct btree_iter iter;
const char *err;
for_each_key(b, k, &iter) {
if (b->ops->is_extents) {
err = "Keys out of order";
if (p && bkey_cmp(&START_KEY(p), &START_KEY(k)) > 0)
goto bug;
if (bch_ptr_invalid(b, k))
continue;
err = "Overlapping keys";
if (p && bkey_cmp(p, &START_KEY(k)) > 0)
goto bug;
} else {
if (bch_ptr_bad(b, k))
continue;
err = "Duplicate keys";
if (p && !bkey_cmp(p, k))
goto bug;
}
p = k;
}
#if 0
err = "Key larger than btree node key";
if (p && bkey_cmp(p, &b->key) > 0)
goto bug;
#endif
return;
bug:
bch_dump_bucket(b);
va_start(args, fmt);
vprintk(fmt, args);
va_end(args);
panic("bch_check_keys error: %s:\n", err);
}
static void bch_btree_iter_next_check(struct btree_iter *iter)
{
struct bkey *k = iter->data->k, *next = bkey_next(k);
if (next < iter->data->end &&
bkey_cmp(k, iter->b->ops->is_extents ?
&START_KEY(next) : next) > 0) {
bch_dump_bucket(iter->b);
panic("Key skipped backwards\n");
}
}
#else
static inline void bch_btree_iter_next_check(struct btree_iter *iter) {}
#endif
/* Keylists */
int __bch_keylist_realloc(struct keylist *l, unsigned int u64s)
{
size_t oldsize = bch_keylist_nkeys(l);
size_t newsize = oldsize + u64s;
uint64_t *old_keys = l->keys_p == l->inline_keys ? NULL : l->keys_p;
uint64_t *new_keys;
newsize = roundup_pow_of_two(newsize);
if (newsize <= KEYLIST_INLINE ||
roundup_pow_of_two(oldsize) == newsize)
return 0;
new_keys = krealloc(old_keys, sizeof(uint64_t) * newsize, GFP_NOIO);
if (!new_keys)
return -ENOMEM;
if (!old_keys)
memcpy(new_keys, l->inline_keys, sizeof(uint64_t) * oldsize);
l->keys_p = new_keys;
l->top_p = new_keys + oldsize;
return 0;
}
/* Pop the top key of keylist by pointing l->top to its previous key */
struct bkey *bch_keylist_pop(struct keylist *l)
{
struct bkey *k = l->keys;
if (k == l->top)
return NULL;
while (bkey_next(k) != l->top)
k = bkey_next(k);
return l->top = k;
}
/* Pop the bottom key of keylist and update l->top_p */
void bch_keylist_pop_front(struct keylist *l)
{
l->top_p -= bkey_u64s(l->keys);
memmove(l->keys,
bkey_next(l->keys),
bch_keylist_bytes(l));
}
/* Key/pointer manipulation */
void bch_bkey_copy_single_ptr(struct bkey *dest, const struct bkey *src,
unsigned int i)
{
BUG_ON(i > KEY_PTRS(src));
/* Only copy the header, key, and one pointer. */
memcpy(dest, src, 2 * sizeof(uint64_t));
dest->ptr[0] = src->ptr[i];
SET_KEY_PTRS(dest, 1);
/* We didn't copy the checksum so clear that bit. */
SET_KEY_CSUM(dest, 0);
}
bool __bch_cut_front(const struct bkey *where, struct bkey *k)
{
unsigned int i, len = 0;
if (bkey_cmp(where, &START_KEY(k)) <= 0)
return false;
if (bkey_cmp(where, k) < 0)
len = KEY_OFFSET(k) - KEY_OFFSET(where);
else
bkey_copy_key(k, where);
for (i = 0; i < KEY_PTRS(k); i++)
SET_PTR_OFFSET(k, i, PTR_OFFSET(k, i) + KEY_SIZE(k) - len);
BUG_ON(len > KEY_SIZE(k));
SET_KEY_SIZE(k, len);
return true;
}
bool __bch_cut_back(const struct bkey *where, struct bkey *k)
{
unsigned int len = 0;
if (bkey_cmp(where, k) >= 0)
return false;
BUG_ON(KEY_INODE(where) != KEY_INODE(k));
if (bkey_cmp(where, &START_KEY(k)) > 0)
len = KEY_OFFSET(where) - KEY_START(k);
bkey_copy_key(k, where);
BUG_ON(len > KEY_SIZE(k));
SET_KEY_SIZE(k, len);
return true;
}
/* Auxiliary search trees */
/* 32 bits total: */
#define BKEY_MID_BITS 3
#define BKEY_EXPONENT_BITS 7
#define BKEY_MANTISSA_BITS (32 - BKEY_MID_BITS - BKEY_EXPONENT_BITS)
#define BKEY_MANTISSA_MASK ((1 << BKEY_MANTISSA_BITS) - 1)
struct bkey_float {
unsigned int exponent:BKEY_EXPONENT_BITS;
unsigned int m:BKEY_MID_BITS;
unsigned int mantissa:BKEY_MANTISSA_BITS;
} __packed;
/*
* BSET_CACHELINE was originally intended to match the hardware cacheline size -
* it used to be 64, but I realized the lookup code would touch slightly less
* memory if it was 128.
*
* It definites the number of bytes (in struct bset) per struct bkey_float in
* the auxiliar search tree - when we're done searching the bset_float tree we
* have this many bytes left that we do a linear search over.
*
* Since (after level 5) every level of the bset_tree is on a new cacheline,
* we're touching one fewer cacheline in the bset tree in exchange for one more
* cacheline in the linear search - but the linear search might stop before it
* gets to the second cacheline.
*/
#define BSET_CACHELINE 128
/* Space required for the btree node keys */
static inline size_t btree_keys_bytes(struct btree_keys *b)
{
return PAGE_SIZE << b->page_order;
}
static inline size_t btree_keys_cachelines(struct btree_keys *b)
{
return btree_keys_bytes(b) / BSET_CACHELINE;
}
/* Space required for the auxiliary search trees */
static inline size_t bset_tree_bytes(struct btree_keys *b)
{
return btree_keys_cachelines(b) * sizeof(struct bkey_float);
}
/* Space required for the prev pointers */
static inline size_t bset_prev_bytes(struct btree_keys *b)
{
return btree_keys_cachelines(b) * sizeof(uint8_t);
}
/* Memory allocation */
void bch_btree_keys_free(struct btree_keys *b)
{
struct bset_tree *t = b->set;
if (bset_prev_bytes(b) < PAGE_SIZE)
kfree(t->prev);
else
free_pages((unsigned long) t->prev,
get_order(bset_prev_bytes(b)));
if (bset_tree_bytes(b) < PAGE_SIZE)
kfree(t->tree);
else
free_pages((unsigned long) t->tree,
get_order(bset_tree_bytes(b)));
free_pages((unsigned long) t->data, b->page_order);
t->prev = NULL;
t->tree = NULL;
t->data = NULL;
}
int bch_btree_keys_alloc(struct btree_keys *b,
unsigned int page_order,
gfp_t gfp)
{
struct bset_tree *t = b->set;
BUG_ON(t->data);
b->page_order = page_order;
t->data = (void *) __get_free_pages(__GFP_COMP|gfp, b->page_order);
if (!t->data)
goto err;
t->tree = bset_tree_bytes(b) < PAGE_SIZE
? kmalloc(bset_tree_bytes(b), gfp)
: (void *) __get_free_pages(gfp, get_order(bset_tree_bytes(b)));
if (!t->tree)
goto err;
t->prev = bset_prev_bytes(b) < PAGE_SIZE
? kmalloc(bset_prev_bytes(b), gfp)
: (void *) __get_free_pages(gfp, get_order(bset_prev_bytes(b)));
if (!t->prev)
goto err;
return 0;
err:
bch_btree_keys_free(b);
return -ENOMEM;
}
void bch_btree_keys_init(struct btree_keys *b, const struct btree_keys_ops *ops,
bool *expensive_debug_checks)
{
b->ops = ops;
b->expensive_debug_checks = expensive_debug_checks;
b->nsets = 0;
b->last_set_unwritten = 0;
/*
* struct btree_keys in embedded in struct btree, and struct
* bset_tree is embedded into struct btree_keys. They are all
* initialized as 0 by kzalloc() in mca_bucket_alloc(), and
* b->set[0].data is allocated in bch_btree_keys_alloc(), so we
* don't have to initiate b->set[].size and b->set[].data here
* any more.
*/
}
/* Binary tree stuff for auxiliary search trees */
/*
* return array index next to j when does in-order traverse
* of a binary tree which is stored in a linear array
*/
static unsigned int inorder_next(unsigned int j, unsigned int size)
{
if (j * 2 + 1 < size) {
j = j * 2 + 1;
while (j * 2 < size)
j *= 2;
} else
j >>= ffz(j) + 1;
return j;
}
/*
* return array index previous to j when does in-order traverse
* of a binary tree which is stored in a linear array
*/
static unsigned int inorder_prev(unsigned int j, unsigned int size)
{
if (j * 2 < size) {
j = j * 2;
while (j * 2 + 1 < size)
j = j * 2 + 1;
} else
j >>= ffs(j);
return j;
}
/*
* I have no idea why this code works... and I'm the one who wrote it
*
* However, I do know what it does:
* Given a binary tree constructed in an array (i.e. how you normally implement
* a heap), it converts a node in the tree - referenced by array index - to the
* index it would have if you did an inorder traversal.
*
* Also tested for every j, size up to size somewhere around 6 million.
*
* The binary tree starts at array index 1, not 0
* extra is a function of size:
* extra = (size - rounddown_pow_of_two(size - 1)) << 1;
*/
static unsigned int __to_inorder(unsigned int j,
unsigned int size,
unsigned int extra)
{
unsigned int b = fls(j);
unsigned int shift = fls(size - 1) - b;
j ^= 1U << (b - 1);
j <<= 1;
j |= 1;
j <<= shift;
if (j > extra)
j -= (j - extra) >> 1;
return j;
}
/*
* Return the cacheline index in bset_tree->data, where j is index
* from a linear array which stores the auxiliar binary tree
*/
static unsigned int to_inorder(unsigned int j, struct bset_tree *t)
{
return __to_inorder(j, t->size, t->extra);
}
static unsigned int __inorder_to_tree(unsigned int j,
unsigned int size,
unsigned int extra)
{
unsigned int shift;
if (j > extra)
j += j - extra;
shift = ffs(j);
j >>= shift;
j |= roundup_pow_of_two(size) >> shift;
return j;
}
/*
* Return an index from a linear array which stores the auxiliar binary
* tree, j is the cacheline index of t->data.
*/
static unsigned int inorder_to_tree(unsigned int j, struct bset_tree *t)
{
return __inorder_to_tree(j, t->size, t->extra);
}
#if 0
void inorder_test(void)
{
unsigned long done = 0;
ktime_t start = ktime_get();
for (unsigned int size = 2;
size < 65536000;
size++) {
unsigned int extra =
(size - rounddown_pow_of_two(size - 1)) << 1;
unsigned int i = 1, j = rounddown_pow_of_two(size - 1);
if (!(size % 4096))
pr_notice("loop %u, %llu per us\n", size,
done / ktime_us_delta(ktime_get(), start));
while (1) {
if (__inorder_to_tree(i, size, extra) != j)
panic("size %10u j %10u i %10u", size, j, i);
if (__to_inorder(j, size, extra) != i)
panic("size %10u j %10u i %10u", size, j, i);
if (j == rounddown_pow_of_two(size) - 1)
break;
BUG_ON(inorder_prev(inorder_next(j, size), size) != j);
j = inorder_next(j, size);
i++;
}
done += size - 1;
}
}
#endif
/*
* Cacheline/offset <-> bkey pointer arithmetic:
*
* t->tree is a binary search tree in an array; each node corresponds to a key
* in one cacheline in t->set (BSET_CACHELINE bytes).
*
* This means we don't have to store the full index of the key that a node in
* the binary tree points to; to_inorder() gives us the cacheline, and then
* bkey_float->m gives us the offset within that cacheline, in units of 8 bytes.
*
* cacheline_to_bkey() and friends abstract out all the pointer arithmetic to
* make this work.
*
* To construct the bfloat for an arbitrary key we need to know what the key
* immediately preceding it is: we have to check if the two keys differ in the
* bits we're going to store in bkey_float->mantissa. t->prev[j] stores the size
* of the previous key so we can walk backwards to it from t->tree[j]'s key.
*/
static struct bkey *cacheline_to_bkey(struct bset_tree *t,
unsigned int cacheline,
unsigned int offset)
{
return ((void *) t->data) + cacheline * BSET_CACHELINE + offset * 8;
}
static unsigned int bkey_to_cacheline(struct bset_tree *t, struct bkey *k)
{
return ((void *) k - (void *) t->data) / BSET_CACHELINE;
}
static unsigned int bkey_to_cacheline_offset(struct bset_tree *t,
unsigned int cacheline,
struct bkey *k)
{
return (u64 *) k - (u64 *) cacheline_to_bkey(t, cacheline, 0);
}
static struct bkey *tree_to_bkey(struct bset_tree *t, unsigned int j)
{
return cacheline_to_bkey(t, to_inorder(j, t), t->tree[j].m);
}
static struct bkey *tree_to_prev_bkey(struct bset_tree *t, unsigned int j)
{
return (void *) (((uint64_t *) tree_to_bkey(t, j)) - t->prev[j]);
}
/*
* For the write set - the one we're currently inserting keys into - we don't
* maintain a full search tree, we just keep a simple lookup table in t->prev.
*/
static struct bkey *table_to_bkey(struct bset_tree *t, unsigned int cacheline)
{
return cacheline_to_bkey(t, cacheline, t->prev[cacheline]);
}
static inline uint64_t shrd128(uint64_t high, uint64_t low, uint8_t shift)
{
low >>= shift;
low |= (high << 1) << (63U - shift);
return low;
}
/*
* Calculate mantissa value for struct bkey_float.
* If most significant bit of f->exponent is not set, then
* - f->exponent >> 6 is 0
* - p[0] points to bkey->low
* - p[-1] borrows bits from KEY_INODE() of bkey->high
* if most isgnificant bits of f->exponent is set, then
* - f->exponent >> 6 is 1
* - p[0] points to bits from KEY_INODE() of bkey->high
* - p[-1] points to other bits from KEY_INODE() of
* bkey->high too.
* See make_bfloat() to check when most significant bit of f->exponent
* is set or not.
*/
static inline unsigned int bfloat_mantissa(const struct bkey *k,
struct bkey_float *f)
{
const uint64_t *p = &k->low - (f->exponent >> 6);
return shrd128(p[-1], p[0], f->exponent & 63) & BKEY_MANTISSA_MASK;
}
static void make_bfloat(struct bset_tree *t, unsigned int j)
{
struct bkey_float *f = &t->tree[j];
struct bkey *m = tree_to_bkey(t, j);
struct bkey *p = tree_to_prev_bkey(t, j);
struct bkey *l = is_power_of_2(j)
? t->data->start
: tree_to_prev_bkey(t, j >> ffs(j));
struct bkey *r = is_power_of_2(j + 1)
? bset_bkey_idx(t->data, t->data->keys - bkey_u64s(&t->end))
: tree_to_bkey(t, j >> (ffz(j) + 1));
BUG_ON(m < l || m > r);
BUG_ON(bkey_next(p) != m);
/*
* If l and r have different KEY_INODE values (different backing
* device), f->exponent records how many least significant bits
* are different in KEY_INODE values and sets most significant
* bits to 1 (by +64).
* If l and r have same KEY_INODE value, f->exponent records
* how many different bits in least significant bits of bkey->low.
* See bfloat_mantiss() how the most significant bit of
* f->exponent is used to calculate bfloat mantissa value.
*/
if (KEY_INODE(l) != KEY_INODE(r))
f->exponent = fls64(KEY_INODE(r) ^ KEY_INODE(l)) + 64;
else
f->exponent = fls64(r->low ^ l->low);
f->exponent = max_t(int, f->exponent - BKEY_MANTISSA_BITS, 0);
/*
* Setting f->exponent = 127 flags this node as failed, and causes the
* lookup code to fall back to comparing against the original key.
*/
if (bfloat_mantissa(m, f) != bfloat_mantissa(p, f))
f->mantissa = bfloat_mantissa(m, f) - 1;
else
f->exponent = 127;
}
static void bset_alloc_tree(struct btree_keys *b, struct bset_tree *t)
{
if (t != b->set) {
unsigned int j = roundup(t[-1].size,
64 / sizeof(struct bkey_float));
t->tree = t[-1].tree + j;
t->prev = t[-1].prev + j;
}
while (t < b->set + MAX_BSETS)
t++->size = 0;
}
static void bch_bset_build_unwritten_tree(struct btree_keys *b)
{
struct bset_tree *t = bset_tree_last(b);
BUG_ON(b->last_set_unwritten);
b->last_set_unwritten = 1;
bset_alloc_tree(b, t);
if (t->tree != b->set->tree + btree_keys_cachelines(b)) {
t->prev[0] = bkey_to_cacheline_offset(t, 0, t->data->start);
t->size = 1;
}
}
void bch_bset_init_next(struct btree_keys *b, struct bset *i, uint64_t magic)
{
if (i != b->set->data) {
b->set[++b->nsets].data = i;
i->seq = b->set->data->seq;
} else
get_random_bytes(&i->seq, sizeof(uint64_t));
i->magic = magic;
i->version = 0;
i->keys = 0;
bch_bset_build_unwritten_tree(b);
}
/*
* Build auxiliary binary tree 'struct bset_tree *t', this tree is used to
* accelerate bkey search in a btree node (pointed by bset_tree->data in
* memory). After search in the auxiliar tree by calling bset_search_tree(),
* a struct bset_search_iter is returned which indicates range [l, r] from
* bset_tree->data where the searching bkey might be inside. Then a followed
* linear comparison does the exact search, see __bch_bset_search() for how
* the auxiliary tree is used.
*/
void bch_bset_build_written_tree(struct btree_keys *b)
{
struct bset_tree *t = bset_tree_last(b);
struct bkey *prev = NULL, *k = t->data->start;
unsigned int j, cacheline = 1;
b->last_set_unwritten = 0;
bset_alloc_tree(b, t);
t->size = min_t(unsigned int,
bkey_to_cacheline(t, bset_bkey_last(t->data)),
b->set->tree + btree_keys_cachelines(b) - t->tree);
if (t->size < 2) {
t->size = 0;
return;
}
t->extra = (t->size - rounddown_pow_of_two(t->size - 1)) << 1;
/* First we figure out where the first key in each cacheline is */
for (j = inorder_next(0, t->size);
j;
j = inorder_next(j, t->size)) {
while (bkey_to_cacheline(t, k) < cacheline) {
prev = k;
k = bkey_next(k);
}
t->prev[j] = bkey_u64s(prev);
t->tree[j].m = bkey_to_cacheline_offset(t, cacheline++, k);
}
while (bkey_next(k) != bset_bkey_last(t->data))
k = bkey_next(k);
t->end = *k;
/* Then we build the tree */
for (j = inorder_next(0, t->size);
j;
j = inorder_next(j, t->size))
make_bfloat(t, j);
}
/* Insert */
void bch_bset_fix_invalidated_key(struct btree_keys *b, struct bkey *k)
{
struct bset_tree *t;
unsigned int inorder, j = 1;
for (t = b->set; t <= bset_tree_last(b); t++)
if (k < bset_bkey_last(t->data))
goto found_set;
BUG();
found_set:
if (!t->size || !bset_written(b, t))
return;
inorder = bkey_to_cacheline(t, k);
if (k == t->data->start)
goto fix_left;
if (bkey_next(k) == bset_bkey_last(t->data)) {
t->end = *k;
goto fix_right;
}
j = inorder_to_tree(inorder, t);
if (j &&
j < t->size &&
k == tree_to_bkey(t, j))
fix_left: do {
make_bfloat(t, j);
j = j * 2;
} while (j < t->size);
j = inorder_to_tree(inorder + 1, t);
if (j &&
j < t->size &&
k == tree_to_prev_bkey(t, j))
fix_right: do {
make_bfloat(t, j);
j = j * 2 + 1;
} while (j < t->size);
}
static void bch_bset_fix_lookup_table(struct btree_keys *b,
struct bset_tree *t,
struct bkey *k)
{
unsigned int shift = bkey_u64s(k);
unsigned int j = bkey_to_cacheline(t, k);
/* We're getting called from btree_split() or btree_gc, just bail out */
if (!t->size)
return;
/*
* k is the key we just inserted; we need to find the entry in the
* lookup table for the first key that is strictly greater than k:
* it's either k's cacheline or the next one
*/
while (j < t->size &&
table_to_bkey(t, j) <= k)
j++;
/*
* Adjust all the lookup table entries, and find a new key for any that
* have gotten too big
*/
for (; j < t->size; j++) {
t->prev[j] += shift;
if (t->prev[j] > 7) {
k = table_to_bkey(t, j - 1);
while (k < cacheline_to_bkey(t, j, 0))
k = bkey_next(k);
t->prev[j] = bkey_to_cacheline_offset(t, j, k);
}
}
if (t->size == b->set->tree + btree_keys_cachelines(b) - t->tree)
return;
/* Possibly add a new entry to the end of the lookup table */
for (k = table_to_bkey(t, t->size - 1);
k != bset_bkey_last(t->data);
k = bkey_next(k))
if (t->size == bkey_to_cacheline(t, k)) {
t->prev[t->size] =
bkey_to_cacheline_offset(t, t->size, k);
t->size++;
}
}
/*
* Tries to merge l and r: l should be lower than r
* Returns true if we were able to merge. If we did merge, l will be the merged
* key, r will be untouched.
*/
bool bch_bkey_try_merge(struct btree_keys *b, struct bkey *l, struct bkey *r)
{
if (!b->ops->key_merge)
return false;
/*
* Generic header checks
* Assumes left and right are in order
* Left and right must be exactly aligned
*/
if (!bch_bkey_equal_header(l, r) ||
bkey_cmp(l, &START_KEY(r)))
return false;
return b->ops->key_merge(b, l, r);
}
void bch_bset_insert(struct btree_keys *b, struct bkey *where,
struct bkey *insert)
{
struct bset_tree *t = bset_tree_last(b);
BUG_ON(!b->last_set_unwritten);
BUG_ON(bset_byte_offset(b, t->data) +
__set_bytes(t->data, t->data->keys + bkey_u64s(insert)) >
PAGE_SIZE << b->page_order);
memmove((uint64_t *) where + bkey_u64s(insert),
where,
(void *) bset_bkey_last(t->data) - (void *) where);
t->data->keys += bkey_u64s(insert);
bkey_copy(where, insert);
bch_bset_fix_lookup_table(b, t, where);
}
unsigned int bch_btree_insert_key(struct btree_keys *b, struct bkey *k,
struct bkey *replace_key)
{
unsigned int status = BTREE_INSERT_STATUS_NO_INSERT;
struct bset *i = bset_tree_last(b)->data;
struct bkey *m, *prev = NULL;
struct btree_iter iter;
struct bkey preceding_key_on_stack = ZERO_KEY;
struct bkey *preceding_key_p = &preceding_key_on_stack;
BUG_ON(b->ops->is_extents && !KEY_SIZE(k));
/*
* If k has preceding key, preceding_key_p will be set to address
* of k's preceding key; otherwise preceding_key_p will be set
* to NULL inside preceding_key().
*/
if (b->ops->is_extents)
preceding_key(&START_KEY(k), &preceding_key_p);
else
preceding_key(k, &preceding_key_p);
m = bch_btree_iter_init(b, &iter, preceding_key_p);
if (b->ops->insert_fixup(b, k, &iter, replace_key))
return status;
status = BTREE_INSERT_STATUS_INSERT;
while (m != bset_bkey_last(i) &&
bkey_cmp(k, b->ops->is_extents ? &START_KEY(m) : m) > 0) {
prev = m;
m = bkey_next(m);
}
/* prev is in the tree, if we merge we're done */
status = BTREE_INSERT_STATUS_BACK_MERGE;
if (prev &&
bch_bkey_try_merge(b, prev, k))
goto merged;
#if 0
status = BTREE_INSERT_STATUS_OVERWROTE;
if (m != bset_bkey_last(i) &&
KEY_PTRS(m) == KEY_PTRS(k) && !KEY_SIZE(m))
goto copy;
#endif
status = BTREE_INSERT_STATUS_FRONT_MERGE;
if (m != bset_bkey_last(i) &&
bch_bkey_try_merge(b, k, m))
goto copy;
bch_bset_insert(b, m, k);
copy: bkey_copy(m, k);
merged:
return status;
}
/* Lookup */
struct bset_search_iter {
struct bkey *l, *r;
};
static struct bset_search_iter bset_search_write_set(struct bset_tree *t,
const struct bkey *search)
{
unsigned int li = 0, ri = t->size;
while (li + 1 != ri) {
unsigned int m = (li + ri) >> 1;
if (bkey_cmp(table_to_bkey(t, m), search) > 0)
ri = m;
else
li = m;
}
return (struct bset_search_iter) {
table_to_bkey(t, li),
ri < t->size ? table_to_bkey(t, ri) : bset_bkey_last(t->data)
};
}
static struct bset_search_iter bset_search_tree(struct bset_tree *t,
const struct bkey *search)
{
struct bkey *l, *r;
struct bkey_float *f;
unsigned int inorder, j, n = 1;
do {
unsigned int p = n << 4;
if (p < t->size)
prefetch(&t->tree[p]);
j = n;
f = &t->tree[j];
if (likely(f->exponent != 127)) {
if (f->mantissa >= bfloat_mantissa(search, f))
n = j * 2;
else
n = j * 2 + 1;
} else {
if (bkey_cmp(tree_to_bkey(t, j), search) > 0)
n = j * 2;
else
n = j * 2 + 1;
}
} while (n < t->size);
inorder = to_inorder(j, t);
/*
* n would have been the node we recursed to - the low bit tells us if
* we recursed left or recursed right.
*/
if (n & 1) {
l = cacheline_to_bkey(t, inorder, f->m);
if (++inorder != t->size) {
f = &t->tree[inorder_next(j, t->size)];
r = cacheline_to_bkey(t, inorder, f->m);
} else
r = bset_bkey_last(t->data);
} else {
r = cacheline_to_bkey(t, inorder, f->m);
if (--inorder) {
f = &t->tree[inorder_prev(j, t->size)];
l = cacheline_to_bkey(t, inorder, f->m);
} else
l = t->data->start;
}
return (struct bset_search_iter) {l, r};
}
struct bkey *__bch_bset_search(struct btree_keys *b, struct bset_tree *t,
const struct bkey *search)
{
struct bset_search_iter i;
/*
* First, we search for a cacheline, then lastly we do a linear search
* within that cacheline.
*
* To search for the cacheline, there's three different possibilities:
* * The set is too small to have a search tree, so we just do a linear
* search over the whole set.
* * The set is the one we're currently inserting into; keeping a full
* auxiliary search tree up to date would be too expensive, so we
* use a much simpler lookup table to do a binary search -
* bset_search_write_set().
* * Or we use the auxiliary search tree we constructed earlier -
* bset_search_tree()
*/
if (unlikely(!t->size)) {
i.l = t->data->start;
i.r = bset_bkey_last(t->data);
} else if (bset_written(b, t)) {
/*
* Each node in the auxiliary search tree covers a certain range
* of bits, and keys above and below the set it covers might
* differ outside those bits - so we have to special case the
* start and end - handle that here:
*/
if (unlikely(bkey_cmp(search, &t->end) >= 0))
return bset_bkey_last(t->data);
if (unlikely(bkey_cmp(search, t->data->start) < 0))
return t->data->start;
i = bset_search_tree(t, search);
} else {
BUG_ON(!b->nsets &&
t->size < bkey_to_cacheline(t, bset_bkey_last(t->data)));
i = bset_search_write_set(t, search);
}
if (btree_keys_expensive_checks(b)) {
BUG_ON(bset_written(b, t) &&
i.l != t->data->start &&
bkey_cmp(tree_to_prev_bkey(t,
inorder_to_tree(bkey_to_cacheline(t, i.l), t)),
search) > 0);
BUG_ON(i.r != bset_bkey_last(t->data) &&
bkey_cmp(i.r, search) <= 0);
}
while (likely(i.l != i.r) &&
bkey_cmp(i.l, search) <= 0)
i.l = bkey_next(i.l);
return i.l;
}
/* Btree iterator */
typedef bool (btree_iter_cmp_fn)(struct btree_iter_set,
struct btree_iter_set);
static inline bool btree_iter_cmp(struct btree_iter_set l,
struct btree_iter_set r)
{
return bkey_cmp(l.k, r.k) > 0;
}
static inline bool btree_iter_end(struct btree_iter *iter)
{
return !iter->used;
}
void bch_btree_iter_push(struct btree_iter *iter, struct bkey *k,
struct bkey *end)
{
if (k != end)
BUG_ON(!heap_add(iter,
((struct btree_iter_set) { k, end }),
btree_iter_cmp));
}
static struct bkey *__bch_btree_iter_init(struct btree_keys *b,
struct btree_iter *iter,
struct bkey *search,
struct bset_tree *start)
{
struct bkey *ret = NULL;
iter->size = ARRAY_SIZE(iter->data);
iter->used = 0;
#ifdef CONFIG_BCACHE_DEBUG
iter->b = b;
#endif
for (; start <= bset_tree_last(b); start++) {
ret = bch_bset_search(b, start, search);
bch_btree_iter_push(iter, ret, bset_bkey_last(start->data));
}
return ret;
}
struct bkey *bch_btree_iter_init(struct btree_keys *b,
struct btree_iter *iter,
struct bkey *search)
{
return __bch_btree_iter_init(b, iter, search, b->set);
}
static inline struct bkey *__bch_btree_iter_next(struct btree_iter *iter,
btree_iter_cmp_fn *cmp)
{
struct btree_iter_set b __maybe_unused;
struct bkey *ret = NULL;
if (!btree_iter_end(iter)) {
bch_btree_iter_next_check(iter);
ret = iter->data->k;
iter->data->k = bkey_next(iter->data->k);
if (iter->data->k > iter->data->end) {
WARN_ONCE(1, "bset was corrupt!\n");
iter->data->k = iter->data->end;
}
if (iter->data->k == iter->data->end)
heap_pop(iter, b, cmp);
else
heap_sift(iter, 0, cmp);
}
return ret;
}
struct bkey *bch_btree_iter_next(struct btree_iter *iter)
{
return __bch_btree_iter_next(iter, btree_iter_cmp);
}
struct bkey *bch_btree_iter_next_filter(struct btree_iter *iter,
struct btree_keys *b, ptr_filter_fn fn)
{
struct bkey *ret;
do {
ret = bch_btree_iter_next(iter);
} while (ret && fn(b, ret));
return ret;
}
/* Mergesort */
void bch_bset_sort_state_free(struct bset_sort_state *state)
{
mempool_exit(&state->pool);
}
int bch_bset_sort_state_init(struct bset_sort_state *state,
unsigned int page_order)
{
spin_lock_init(&state->time.lock);
state->page_order = page_order;
state->crit_factor = int_sqrt(1 << page_order);
return mempool_init_page_pool(&state->pool, 1, page_order);
}
static void btree_mergesort(struct btree_keys *b, struct bset *out,
struct btree_iter *iter,
bool fixup, bool remove_stale)
{
int i;
struct bkey *k, *last = NULL;
BKEY_PADDED(k) tmp;
bool (*bad)(struct btree_keys *, const struct bkey *) = remove_stale
? bch_ptr_bad
: bch_ptr_invalid;
/* Heapify the iterator, using our comparison function */
for (i = iter->used / 2 - 1; i >= 0; --i)
heap_sift(iter, i, b->ops->sort_cmp);
while (!btree_iter_end(iter)) {
if (b->ops->sort_fixup && fixup)
k = b->ops->sort_fixup(iter, &tmp.k);
else
k = NULL;
if (!k)
k = __bch_btree_iter_next(iter, b->ops->sort_cmp);
if (bad(b, k))
continue;
if (!last) {
last = out->start;
bkey_copy(last, k);
} else if (!bch_bkey_try_merge(b, last, k)) {
last = bkey_next(last);
bkey_copy(last, k);
}
}
out->keys = last ? (uint64_t *) bkey_next(last) - out->d : 0;
pr_debug("sorted %i keys\n", out->keys);
}
static void __btree_sort(struct btree_keys *b, struct btree_iter *iter,
unsigned int start, unsigned int order, bool fixup,
struct bset_sort_state *state)
{
uint64_t start_time;
bool used_mempool = false;
struct bset *out = (void *) __get_free_pages(__GFP_NOWARN|GFP_NOWAIT,
order);
if (!out) {
struct page *outp;
BUG_ON(order > state->page_order);
outp = mempool_alloc(&state->pool, GFP_NOIO);
out = page_address(outp);
used_mempool = true;
order = state->page_order;
}
start_time = local_clock();
btree_mergesort(b, out, iter, fixup, false);
b->nsets = start;
if (!start && order == b->page_order) {
/*
* Our temporary buffer is the same size as the btree node's
* buffer, we can just swap buffers instead of doing a big
* memcpy()
*
* Don't worry event 'out' is allocated from mempool, it can
* still be swapped here. Because state->pool is a page mempool
* created by mempool_init_page_pool(), which allocates
* pages by alloc_pages() indeed.
*/
out->magic = b->set->data->magic;
out->seq = b->set->data->seq;
out->version = b->set->data->version;
swap(out, b->set->data);
} else {
b->set[start].data->keys = out->keys;
memcpy(b->set[start].data->start, out->start,
(void *) bset_bkey_last(out) - (void *) out->start);
}
if (used_mempool)
mempool_free(virt_to_page(out), &state->pool);
else
free_pages((unsigned long) out, order);
bch_bset_build_written_tree(b);
if (!start)
bch_time_stats_update(&state->time, start_time);
}
void bch_btree_sort_partial(struct btree_keys *b, unsigned int start,
struct bset_sort_state *state)
{
size_t order = b->page_order, keys = 0;
struct btree_iter iter;
int oldsize = bch_count_data(b);
__bch_btree_iter_init(b, &iter, NULL, &b->set[start]);
if (start) {
unsigned int i;
for (i = start; i <= b->nsets; i++)
keys += b->set[i].data->keys;
order = get_order(__set_bytes(b->set->data, keys));
}
__btree_sort(b, &iter, start, order, false, state);
EBUG_ON(oldsize >= 0 && bch_count_data(b) != oldsize);
}
void bch_btree_sort_and_fix_extents(struct btree_keys *b,
struct btree_iter *iter,
struct bset_sort_state *state)
{
__btree_sort(b, iter, 0, b->page_order, true, state);
}
void bch_btree_sort_into(struct btree_keys *b, struct btree_keys *new,
struct bset_sort_state *state)
{
uint64_t start_time = local_clock();
struct btree_iter iter;
bch_btree_iter_init(b, &iter, NULL);
btree_mergesort(b, new->set->data, &iter, false, true);
bch_time_stats_update(&state->time, start_time);
new->set->size = 0; // XXX: why?
}
#define SORT_CRIT (4096 / sizeof(uint64_t))
void bch_btree_sort_lazy(struct btree_keys *b, struct bset_sort_state *state)
{
unsigned int crit = SORT_CRIT;
int i;
/* Don't sort if nothing to do */
if (!b->nsets)
goto out;
for (i = b->nsets - 1; i >= 0; --i) {
crit *= state->crit_factor;
if (b->set[i].data->keys < crit) {
bch_btree_sort_partial(b, i, state);
return;
}
}
/* Sort if we'd overflow */
if (b->nsets + 1 == MAX_BSETS) {
bch_btree_sort(b, state);
return;
}
out:
bch_bset_build_written_tree(b);
}
void bch_btree_keys_stats(struct btree_keys *b, struct bset_stats *stats)
{
unsigned int i;
for (i = 0; i <= b->nsets; i++) {
struct bset_tree *t = &b->set[i];
size_t bytes = t->data->keys * sizeof(uint64_t);
size_t j;
if (bset_written(b, t)) {
stats->sets_written++;
stats->bytes_written += bytes;
stats->floats += t->size - 1;
for (j = 1; j < t->size; j++)
if (t->tree[j].exponent == 127)
stats->failed++;
} else {
stats->sets_unwritten++;
stats->bytes_unwritten += bytes;
}
}
}
| linux-master | drivers/md/bcache/bset.c |
// SPDX-License-Identifier: GPL-2.0
/*
* bcache stats code
*
* Copyright 2012 Google, Inc.
*/
#include "bcache.h"
#include "stats.h"
#include "btree.h"
#include "sysfs.h"
/*
* We keep absolute totals of various statistics, and addionally a set of three
* rolling averages.
*
* Every so often, a timer goes off and rescales the rolling averages.
* accounting_rescale[] is how many times the timer has to go off before we
* rescale each set of numbers; that gets us half lives of 5 minutes, one hour,
* and one day.
*
* accounting_delay is how often the timer goes off - 22 times in 5 minutes,
* and accounting_weight is what we use to rescale:
*
* pow(31 / 32, 22) ~= 1/2
*
* So that we don't have to increment each set of numbers every time we (say)
* get a cache hit, we increment a single atomic_t in acc->collector, and when
* the rescale function runs it resets the atomic counter to 0 and adds its
* old value to each of the exported numbers.
*
* To reduce rounding error, the numbers in struct cache_stats are all
* stored left shifted by 16, and scaled back in the sysfs show() function.
*/
static const unsigned int DAY_RESCALE = 288;
static const unsigned int HOUR_RESCALE = 12;
static const unsigned int FIVE_MINUTE_RESCALE = 1;
static const unsigned int accounting_delay = (HZ * 300) / 22;
static const unsigned int accounting_weight = 32;
/* sysfs reading/writing */
read_attribute(cache_hits);
read_attribute(cache_misses);
read_attribute(cache_bypass_hits);
read_attribute(cache_bypass_misses);
read_attribute(cache_hit_ratio);
read_attribute(cache_miss_collisions);
read_attribute(bypassed);
SHOW(bch_stats)
{
struct cache_stats *s =
container_of(kobj, struct cache_stats, kobj);
#define var(stat) (s->stat >> 16)
var_print(cache_hits);
var_print(cache_misses);
var_print(cache_bypass_hits);
var_print(cache_bypass_misses);
sysfs_print(cache_hit_ratio,
DIV_SAFE(var(cache_hits) * 100,
var(cache_hits) + var(cache_misses)));
var_print(cache_miss_collisions);
sysfs_hprint(bypassed, var(sectors_bypassed) << 9);
#undef var
return 0;
}
STORE(bch_stats)
{
return size;
}
static void bch_stats_release(struct kobject *k)
{
}
static struct attribute *bch_stats_attrs[] = {
&sysfs_cache_hits,
&sysfs_cache_misses,
&sysfs_cache_bypass_hits,
&sysfs_cache_bypass_misses,
&sysfs_cache_hit_ratio,
&sysfs_cache_miss_collisions,
&sysfs_bypassed,
NULL
};
ATTRIBUTE_GROUPS(bch_stats);
static KTYPE(bch_stats);
int bch_cache_accounting_add_kobjs(struct cache_accounting *acc,
struct kobject *parent)
{
int ret = kobject_add(&acc->total.kobj, parent,
"stats_total");
ret = ret ?: kobject_add(&acc->five_minute.kobj, parent,
"stats_five_minute");
ret = ret ?: kobject_add(&acc->hour.kobj, parent,
"stats_hour");
ret = ret ?: kobject_add(&acc->day.kobj, parent,
"stats_day");
return ret;
}
void bch_cache_accounting_clear(struct cache_accounting *acc)
{
acc->total.cache_hits = 0;
acc->total.cache_misses = 0;
acc->total.cache_bypass_hits = 0;
acc->total.cache_bypass_misses = 0;
acc->total.cache_miss_collisions = 0;
acc->total.sectors_bypassed = 0;
}
void bch_cache_accounting_destroy(struct cache_accounting *acc)
{
kobject_put(&acc->total.kobj);
kobject_put(&acc->five_minute.kobj);
kobject_put(&acc->hour.kobj);
kobject_put(&acc->day.kobj);
atomic_set(&acc->closing, 1);
if (del_timer_sync(&acc->timer))
closure_return(&acc->cl);
}
/* EWMA scaling */
static void scale_stat(unsigned long *stat)
{
*stat = ewma_add(*stat, 0, accounting_weight, 0);
}
static void scale_stats(struct cache_stats *stats, unsigned long rescale_at)
{
if (++stats->rescale == rescale_at) {
stats->rescale = 0;
scale_stat(&stats->cache_hits);
scale_stat(&stats->cache_misses);
scale_stat(&stats->cache_bypass_hits);
scale_stat(&stats->cache_bypass_misses);
scale_stat(&stats->cache_miss_collisions);
scale_stat(&stats->sectors_bypassed);
}
}
static void scale_accounting(struct timer_list *t)
{
struct cache_accounting *acc = from_timer(acc, t, timer);
#define move_stat(name) do { \
unsigned int t = atomic_xchg(&acc->collector.name, 0); \
t <<= 16; \
acc->five_minute.name += t; \
acc->hour.name += t; \
acc->day.name += t; \
acc->total.name += t; \
} while (0)
move_stat(cache_hits);
move_stat(cache_misses);
move_stat(cache_bypass_hits);
move_stat(cache_bypass_misses);
move_stat(cache_miss_collisions);
move_stat(sectors_bypassed);
scale_stats(&acc->total, 0);
scale_stats(&acc->day, DAY_RESCALE);
scale_stats(&acc->hour, HOUR_RESCALE);
scale_stats(&acc->five_minute, FIVE_MINUTE_RESCALE);
acc->timer.expires += accounting_delay;
if (!atomic_read(&acc->closing))
add_timer(&acc->timer);
else
closure_return(&acc->cl);
}
static void mark_cache_stats(struct cache_stat_collector *stats,
bool hit, bool bypass)
{
if (!bypass)
if (hit)
atomic_inc(&stats->cache_hits);
else
atomic_inc(&stats->cache_misses);
else
if (hit)
atomic_inc(&stats->cache_bypass_hits);
else
atomic_inc(&stats->cache_bypass_misses);
}
void bch_mark_cache_accounting(struct cache_set *c, struct bcache_device *d,
bool hit, bool bypass)
{
struct cached_dev *dc = container_of(d, struct cached_dev, disk);
mark_cache_stats(&dc->accounting.collector, hit, bypass);
mark_cache_stats(&c->accounting.collector, hit, bypass);
}
void bch_mark_cache_miss_collision(struct cache_set *c, struct bcache_device *d)
{
struct cached_dev *dc = container_of(d, struct cached_dev, disk);
atomic_inc(&dc->accounting.collector.cache_miss_collisions);
atomic_inc(&c->accounting.collector.cache_miss_collisions);
}
void bch_mark_sectors_bypassed(struct cache_set *c, struct cached_dev *dc,
int sectors)
{
atomic_add(sectors, &dc->accounting.collector.sectors_bypassed);
atomic_add(sectors, &c->accounting.collector.sectors_bypassed);
}
void bch_cache_accounting_init(struct cache_accounting *acc,
struct closure *parent)
{
kobject_init(&acc->total.kobj, &bch_stats_ktype);
kobject_init(&acc->five_minute.kobj, &bch_stats_ktype);
kobject_init(&acc->hour.kobj, &bch_stats_ktype);
kobject_init(&acc->day.kobj, &bch_stats_ktype);
closure_init(&acc->cl, parent);
timer_setup(&acc->timer, scale_accounting, 0);
acc->timer.expires = jiffies + accounting_delay;
add_timer(&acc->timer);
}
| linux-master | drivers/md/bcache/stats.c |
// SPDX-License-Identifier: GPL-2.0
/*
* Primary bucket allocation code
*
* Copyright 2012 Google, Inc.
*
* Allocation in bcache is done in terms of buckets:
*
* Each bucket has associated an 8 bit gen; this gen corresponds to the gen in
* btree pointers - they must match for the pointer to be considered valid.
*
* Thus (assuming a bucket has no dirty data or metadata in it) we can reuse a
* bucket simply by incrementing its gen.
*
* The gens (along with the priorities; it's really the gens are important but
* the code is named as if it's the priorities) are written in an arbitrary list
* of buckets on disk, with a pointer to them in the journal header.
*
* When we invalidate a bucket, we have to write its new gen to disk and wait
* for that write to complete before we use it - otherwise after a crash we
* could have pointers that appeared to be good but pointed to data that had
* been overwritten.
*
* Since the gens and priorities are all stored contiguously on disk, we can
* batch this up: We fill up the free_inc list with freshly invalidated buckets,
* call prio_write(), and when prio_write() finishes we pull buckets off the
* free_inc list and optionally discard them.
*
* free_inc isn't the only freelist - if it was, we'd often to sleep while
* priorities and gens were being written before we could allocate. c->free is a
* smaller freelist, and buckets on that list are always ready to be used.
*
* If we've got discards enabled, that happens when a bucket moves from the
* free_inc list to the free list.
*
* There is another freelist, because sometimes we have buckets that we know
* have nothing pointing into them - these we can reuse without waiting for
* priorities to be rewritten. These come from freed btree nodes and buckets
* that garbage collection discovered no longer had valid keys pointing into
* them (because they were overwritten). That's the unused list - buckets on the
* unused list move to the free list, optionally being discarded in the process.
*
* It's also important to ensure that gens don't wrap around - with respect to
* either the oldest gen in the btree or the gen on disk. This is quite
* difficult to do in practice, but we explicitly guard against it anyways - if
* a bucket is in danger of wrapping around we simply skip invalidating it that
* time around, and we garbage collect or rewrite the priorities sooner than we
* would have otherwise.
*
* bch_bucket_alloc() allocates a single bucket from a specific cache.
*
* bch_bucket_alloc_set() allocates one bucket from different caches
* out of a cache set.
*
* free_some_buckets() drives all the processes described above. It's called
* from bch_bucket_alloc() and a few other places that need to make sure free
* buckets are ready.
*
* invalidate_buckets_(lru|fifo)() find buckets that are available to be
* invalidated, and then invalidate them and stick them on the free_inc list -
* in either lru or fifo order.
*/
#include "bcache.h"
#include "btree.h"
#include <linux/blkdev.h>
#include <linux/kthread.h>
#include <linux/random.h>
#include <trace/events/bcache.h>
#define MAX_OPEN_BUCKETS 128
/* Bucket heap / gen */
uint8_t bch_inc_gen(struct cache *ca, struct bucket *b)
{
uint8_t ret = ++b->gen;
ca->set->need_gc = max(ca->set->need_gc, bucket_gc_gen(b));
WARN_ON_ONCE(ca->set->need_gc > BUCKET_GC_GEN_MAX);
return ret;
}
void bch_rescale_priorities(struct cache_set *c, int sectors)
{
struct cache *ca;
struct bucket *b;
unsigned long next = c->nbuckets * c->cache->sb.bucket_size / 1024;
int r;
atomic_sub(sectors, &c->rescale);
do {
r = atomic_read(&c->rescale);
if (r >= 0)
return;
} while (atomic_cmpxchg(&c->rescale, r, r + next) != r);
mutex_lock(&c->bucket_lock);
c->min_prio = USHRT_MAX;
ca = c->cache;
for_each_bucket(b, ca)
if (b->prio &&
b->prio != BTREE_PRIO &&
!atomic_read(&b->pin)) {
b->prio--;
c->min_prio = min(c->min_prio, b->prio);
}
mutex_unlock(&c->bucket_lock);
}
/*
* Background allocation thread: scans for buckets to be invalidated,
* invalidates them, rewrites prios/gens (marking them as invalidated on disk),
* then optionally issues discard commands to the newly free buckets, then puts
* them on the various freelists.
*/
static inline bool can_inc_bucket_gen(struct bucket *b)
{
return bucket_gc_gen(b) < BUCKET_GC_GEN_MAX;
}
bool bch_can_invalidate_bucket(struct cache *ca, struct bucket *b)
{
BUG_ON(!ca->set->gc_mark_valid);
return (!GC_MARK(b) ||
GC_MARK(b) == GC_MARK_RECLAIMABLE) &&
!atomic_read(&b->pin) &&
can_inc_bucket_gen(b);
}
void __bch_invalidate_one_bucket(struct cache *ca, struct bucket *b)
{
lockdep_assert_held(&ca->set->bucket_lock);
BUG_ON(GC_MARK(b) && GC_MARK(b) != GC_MARK_RECLAIMABLE);
if (GC_SECTORS_USED(b))
trace_bcache_invalidate(ca, b - ca->buckets);
bch_inc_gen(ca, b);
b->prio = INITIAL_PRIO;
atomic_inc(&b->pin);
}
static void bch_invalidate_one_bucket(struct cache *ca, struct bucket *b)
{
__bch_invalidate_one_bucket(ca, b);
fifo_push(&ca->free_inc, b - ca->buckets);
}
/*
* Determines what order we're going to reuse buckets, smallest bucket_prio()
* first: we also take into account the number of sectors of live data in that
* bucket, and in order for that multiply to make sense we have to scale bucket
*
* Thus, we scale the bucket priorities so that the bucket with the smallest
* prio is worth 1/8th of what INITIAL_PRIO is worth.
*/
#define bucket_prio(b) \
({ \
unsigned int min_prio = (INITIAL_PRIO - ca->set->min_prio) / 8; \
\
(b->prio - ca->set->min_prio + min_prio) * GC_SECTORS_USED(b); \
})
#define bucket_max_cmp(l, r) (bucket_prio(l) < bucket_prio(r))
#define bucket_min_cmp(l, r) (bucket_prio(l) > bucket_prio(r))
static void invalidate_buckets_lru(struct cache *ca)
{
struct bucket *b;
ssize_t i;
ca->heap.used = 0;
for_each_bucket(b, ca) {
if (!bch_can_invalidate_bucket(ca, b))
continue;
if (!heap_full(&ca->heap))
heap_add(&ca->heap, b, bucket_max_cmp);
else if (bucket_max_cmp(b, heap_peek(&ca->heap))) {
ca->heap.data[0] = b;
heap_sift(&ca->heap, 0, bucket_max_cmp);
}
}
for (i = ca->heap.used / 2 - 1; i >= 0; --i)
heap_sift(&ca->heap, i, bucket_min_cmp);
while (!fifo_full(&ca->free_inc)) {
if (!heap_pop(&ca->heap, b, bucket_min_cmp)) {
/*
* We don't want to be calling invalidate_buckets()
* multiple times when it can't do anything
*/
ca->invalidate_needs_gc = 1;
wake_up_gc(ca->set);
return;
}
bch_invalidate_one_bucket(ca, b);
}
}
static void invalidate_buckets_fifo(struct cache *ca)
{
struct bucket *b;
size_t checked = 0;
while (!fifo_full(&ca->free_inc)) {
if (ca->fifo_last_bucket < ca->sb.first_bucket ||
ca->fifo_last_bucket >= ca->sb.nbuckets)
ca->fifo_last_bucket = ca->sb.first_bucket;
b = ca->buckets + ca->fifo_last_bucket++;
if (bch_can_invalidate_bucket(ca, b))
bch_invalidate_one_bucket(ca, b);
if (++checked >= ca->sb.nbuckets) {
ca->invalidate_needs_gc = 1;
wake_up_gc(ca->set);
return;
}
}
}
static void invalidate_buckets_random(struct cache *ca)
{
struct bucket *b;
size_t checked = 0;
while (!fifo_full(&ca->free_inc)) {
size_t n;
get_random_bytes(&n, sizeof(n));
n %= (size_t) (ca->sb.nbuckets - ca->sb.first_bucket);
n += ca->sb.first_bucket;
b = ca->buckets + n;
if (bch_can_invalidate_bucket(ca, b))
bch_invalidate_one_bucket(ca, b);
if (++checked >= ca->sb.nbuckets / 2) {
ca->invalidate_needs_gc = 1;
wake_up_gc(ca->set);
return;
}
}
}
static void invalidate_buckets(struct cache *ca)
{
BUG_ON(ca->invalidate_needs_gc);
switch (CACHE_REPLACEMENT(&ca->sb)) {
case CACHE_REPLACEMENT_LRU:
invalidate_buckets_lru(ca);
break;
case CACHE_REPLACEMENT_FIFO:
invalidate_buckets_fifo(ca);
break;
case CACHE_REPLACEMENT_RANDOM:
invalidate_buckets_random(ca);
break;
}
}
#define allocator_wait(ca, cond) \
do { \
while (1) { \
set_current_state(TASK_INTERRUPTIBLE); \
if (cond) \
break; \
\
mutex_unlock(&(ca)->set->bucket_lock); \
if (kthread_should_stop() || \
test_bit(CACHE_SET_IO_DISABLE, &ca->set->flags)) { \
set_current_state(TASK_RUNNING); \
goto out; \
} \
\
schedule(); \
mutex_lock(&(ca)->set->bucket_lock); \
} \
__set_current_state(TASK_RUNNING); \
} while (0)
static int bch_allocator_push(struct cache *ca, long bucket)
{
unsigned int i;
/* Prios/gens are actually the most important reserve */
if (fifo_push(&ca->free[RESERVE_PRIO], bucket))
return true;
for (i = 0; i < RESERVE_NR; i++)
if (fifo_push(&ca->free[i], bucket))
return true;
return false;
}
static int bch_allocator_thread(void *arg)
{
struct cache *ca = arg;
mutex_lock(&ca->set->bucket_lock);
while (1) {
/*
* First, we pull buckets off of the unused and free_inc lists,
* possibly issue discards to them, then we add the bucket to
* the free list:
*/
while (1) {
long bucket;
if (!fifo_pop(&ca->free_inc, bucket))
break;
if (ca->discard) {
mutex_unlock(&ca->set->bucket_lock);
blkdev_issue_discard(ca->bdev,
bucket_to_sector(ca->set, bucket),
ca->sb.bucket_size, GFP_KERNEL);
mutex_lock(&ca->set->bucket_lock);
}
allocator_wait(ca, bch_allocator_push(ca, bucket));
wake_up(&ca->set->btree_cache_wait);
wake_up(&ca->set->bucket_wait);
}
/*
* We've run out of free buckets, we need to find some buckets
* we can invalidate. First, invalidate them in memory and add
* them to the free_inc list:
*/
retry_invalidate:
allocator_wait(ca, ca->set->gc_mark_valid &&
!ca->invalidate_needs_gc);
invalidate_buckets(ca);
/*
* Now, we write their new gens to disk so we can start writing
* new stuff to them:
*/
allocator_wait(ca, !atomic_read(&ca->set->prio_blocked));
if (CACHE_SYNC(&ca->sb)) {
/*
* This could deadlock if an allocation with a btree
* node locked ever blocked - having the btree node
* locked would block garbage collection, but here we're
* waiting on garbage collection before we invalidate
* and free anything.
*
* But this should be safe since the btree code always
* uses btree_check_reserve() before allocating now, and
* if it fails it blocks without btree nodes locked.
*/
if (!fifo_full(&ca->free_inc))
goto retry_invalidate;
if (bch_prio_write(ca, false) < 0) {
ca->invalidate_needs_gc = 1;
wake_up_gc(ca->set);
}
}
}
out:
wait_for_kthread_stop();
return 0;
}
/* Allocation */
long bch_bucket_alloc(struct cache *ca, unsigned int reserve, bool wait)
{
DEFINE_WAIT(w);
struct bucket *b;
long r;
/* No allocation if CACHE_SET_IO_DISABLE bit is set */
if (unlikely(test_bit(CACHE_SET_IO_DISABLE, &ca->set->flags)))
return -1;
/* fastpath */
if (fifo_pop(&ca->free[RESERVE_NONE], r) ||
fifo_pop(&ca->free[reserve], r))
goto out;
if (!wait) {
trace_bcache_alloc_fail(ca, reserve);
return -1;
}
do {
prepare_to_wait(&ca->set->bucket_wait, &w,
TASK_UNINTERRUPTIBLE);
mutex_unlock(&ca->set->bucket_lock);
schedule();
mutex_lock(&ca->set->bucket_lock);
} while (!fifo_pop(&ca->free[RESERVE_NONE], r) &&
!fifo_pop(&ca->free[reserve], r));
finish_wait(&ca->set->bucket_wait, &w);
out:
if (ca->alloc_thread)
wake_up_process(ca->alloc_thread);
trace_bcache_alloc(ca, reserve);
if (expensive_debug_checks(ca->set)) {
size_t iter;
long i;
unsigned int j;
for (iter = 0; iter < prio_buckets(ca) * 2; iter++)
BUG_ON(ca->prio_buckets[iter] == (uint64_t) r);
for (j = 0; j < RESERVE_NR; j++)
fifo_for_each(i, &ca->free[j], iter)
BUG_ON(i == r);
fifo_for_each(i, &ca->free_inc, iter)
BUG_ON(i == r);
}
b = ca->buckets + r;
BUG_ON(atomic_read(&b->pin) != 1);
SET_GC_SECTORS_USED(b, ca->sb.bucket_size);
if (reserve <= RESERVE_PRIO) {
SET_GC_MARK(b, GC_MARK_METADATA);
SET_GC_MOVE(b, 0);
b->prio = BTREE_PRIO;
} else {
SET_GC_MARK(b, GC_MARK_RECLAIMABLE);
SET_GC_MOVE(b, 0);
b->prio = INITIAL_PRIO;
}
if (ca->set->avail_nbuckets > 0) {
ca->set->avail_nbuckets--;
bch_update_bucket_in_use(ca->set, &ca->set->gc_stats);
}
return r;
}
void __bch_bucket_free(struct cache *ca, struct bucket *b)
{
SET_GC_MARK(b, 0);
SET_GC_SECTORS_USED(b, 0);
if (ca->set->avail_nbuckets < ca->set->nbuckets) {
ca->set->avail_nbuckets++;
bch_update_bucket_in_use(ca->set, &ca->set->gc_stats);
}
}
void bch_bucket_free(struct cache_set *c, struct bkey *k)
{
unsigned int i;
for (i = 0; i < KEY_PTRS(k); i++)
__bch_bucket_free(c->cache, PTR_BUCKET(c, k, i));
}
int __bch_bucket_alloc_set(struct cache_set *c, unsigned int reserve,
struct bkey *k, bool wait)
{
struct cache *ca;
long b;
/* No allocation if CACHE_SET_IO_DISABLE bit is set */
if (unlikely(test_bit(CACHE_SET_IO_DISABLE, &c->flags)))
return -1;
lockdep_assert_held(&c->bucket_lock);
bkey_init(k);
ca = c->cache;
b = bch_bucket_alloc(ca, reserve, wait);
if (b == -1)
goto err;
k->ptr[0] = MAKE_PTR(ca->buckets[b].gen,
bucket_to_sector(c, b),
ca->sb.nr_this_dev);
SET_KEY_PTRS(k, 1);
return 0;
err:
bch_bucket_free(c, k);
bkey_put(c, k);
return -1;
}
int bch_bucket_alloc_set(struct cache_set *c, unsigned int reserve,
struct bkey *k, bool wait)
{
int ret;
mutex_lock(&c->bucket_lock);
ret = __bch_bucket_alloc_set(c, reserve, k, wait);
mutex_unlock(&c->bucket_lock);
return ret;
}
/* Sector allocator */
struct open_bucket {
struct list_head list;
unsigned int last_write_point;
unsigned int sectors_free;
BKEY_PADDED(key);
};
/*
* We keep multiple buckets open for writes, and try to segregate different
* write streams for better cache utilization: first we try to segregate flash
* only volume write streams from cached devices, secondly we look for a bucket
* where the last write to it was sequential with the current write, and
* failing that we look for a bucket that was last used by the same task.
*
* The ideas is if you've got multiple tasks pulling data into the cache at the
* same time, you'll get better cache utilization if you try to segregate their
* data and preserve locality.
*
* For example, dirty sectors of flash only volume is not reclaimable, if their
* dirty sectors mixed with dirty sectors of cached device, such buckets will
* be marked as dirty and won't be reclaimed, though the dirty data of cached
* device have been written back to backend device.
*
* And say you've starting Firefox at the same time you're copying a
* bunch of files. Firefox will likely end up being fairly hot and stay in the
* cache awhile, but the data you copied might not be; if you wrote all that
* data to the same buckets it'd get invalidated at the same time.
*
* Both of those tasks will be doing fairly random IO so we can't rely on
* detecting sequential IO to segregate their data, but going off of the task
* should be a sane heuristic.
*/
static struct open_bucket *pick_data_bucket(struct cache_set *c,
const struct bkey *search,
unsigned int write_point,
struct bkey *alloc)
{
struct open_bucket *ret, *ret_task = NULL;
list_for_each_entry_reverse(ret, &c->data_buckets, list)
if (UUID_FLASH_ONLY(&c->uuids[KEY_INODE(&ret->key)]) !=
UUID_FLASH_ONLY(&c->uuids[KEY_INODE(search)]))
continue;
else if (!bkey_cmp(&ret->key, search))
goto found;
else if (ret->last_write_point == write_point)
ret_task = ret;
ret = ret_task ?: list_first_entry(&c->data_buckets,
struct open_bucket, list);
found:
if (!ret->sectors_free && KEY_PTRS(alloc)) {
ret->sectors_free = c->cache->sb.bucket_size;
bkey_copy(&ret->key, alloc);
bkey_init(alloc);
}
if (!ret->sectors_free)
ret = NULL;
return ret;
}
/*
* Allocates some space in the cache to write to, and k to point to the newly
* allocated space, and updates KEY_SIZE(k) and KEY_OFFSET(k) (to point to the
* end of the newly allocated space).
*
* May allocate fewer sectors than @sectors, KEY_SIZE(k) indicates how many
* sectors were actually allocated.
*
* If s->writeback is true, will not fail.
*/
bool bch_alloc_sectors(struct cache_set *c,
struct bkey *k,
unsigned int sectors,
unsigned int write_point,
unsigned int write_prio,
bool wait)
{
struct open_bucket *b;
BKEY_PADDED(key) alloc;
unsigned int i;
/*
* We might have to allocate a new bucket, which we can't do with a
* spinlock held. So if we have to allocate, we drop the lock, allocate
* and then retry. KEY_PTRS() indicates whether alloc points to
* allocated bucket(s).
*/
bkey_init(&alloc.key);
spin_lock(&c->data_bucket_lock);
while (!(b = pick_data_bucket(c, k, write_point, &alloc.key))) {
unsigned int watermark = write_prio
? RESERVE_MOVINGGC
: RESERVE_NONE;
spin_unlock(&c->data_bucket_lock);
if (bch_bucket_alloc_set(c, watermark, &alloc.key, wait))
return false;
spin_lock(&c->data_bucket_lock);
}
/*
* If we had to allocate, we might race and not need to allocate the
* second time we call pick_data_bucket(). If we allocated a bucket but
* didn't use it, drop the refcount bch_bucket_alloc_set() took:
*/
if (KEY_PTRS(&alloc.key))
bkey_put(c, &alloc.key);
for (i = 0; i < KEY_PTRS(&b->key); i++)
EBUG_ON(ptr_stale(c, &b->key, i));
/* Set up the pointer to the space we're allocating: */
for (i = 0; i < KEY_PTRS(&b->key); i++)
k->ptr[i] = b->key.ptr[i];
sectors = min(sectors, b->sectors_free);
SET_KEY_OFFSET(k, KEY_OFFSET(k) + sectors);
SET_KEY_SIZE(k, sectors);
SET_KEY_PTRS(k, KEY_PTRS(&b->key));
/*
* Move b to the end of the lru, and keep track of what this bucket was
* last used for:
*/
list_move_tail(&b->list, &c->data_buckets);
bkey_copy_key(&b->key, k);
b->last_write_point = write_point;
b->sectors_free -= sectors;
for (i = 0; i < KEY_PTRS(&b->key); i++) {
SET_PTR_OFFSET(&b->key, i, PTR_OFFSET(&b->key, i) + sectors);
atomic_long_add(sectors,
&c->cache->sectors_written);
}
if (b->sectors_free < c->cache->sb.block_size)
b->sectors_free = 0;
/*
* k takes refcounts on the buckets it points to until it's inserted
* into the btree, but if we're done with this bucket we just transfer
* get_data_bucket()'s refcount.
*/
if (b->sectors_free)
for (i = 0; i < KEY_PTRS(&b->key); i++)
atomic_inc(&PTR_BUCKET(c, &b->key, i)->pin);
spin_unlock(&c->data_bucket_lock);
return true;
}
/* Init */
void bch_open_buckets_free(struct cache_set *c)
{
struct open_bucket *b;
while (!list_empty(&c->data_buckets)) {
b = list_first_entry(&c->data_buckets,
struct open_bucket, list);
list_del(&b->list);
kfree(b);
}
}
int bch_open_buckets_alloc(struct cache_set *c)
{
int i;
spin_lock_init(&c->data_bucket_lock);
for (i = 0; i < MAX_OPEN_BUCKETS; i++) {
struct open_bucket *b = kzalloc(sizeof(*b), GFP_KERNEL);
if (!b)
return -ENOMEM;
list_add(&b->list, &c->data_buckets);
}
return 0;
}
int bch_cache_allocator_start(struct cache *ca)
{
struct task_struct *k = kthread_run(bch_allocator_thread,
ca, "bcache_allocator");
if (IS_ERR(k))
return PTR_ERR(k);
ca->alloc_thread = k;
return 0;
}
| linux-master | drivers/md/bcache/alloc.c |
// SPDX-License-Identifier: GPL-2.0
/*
* Assorted bcache debug code
*
* Copyright 2010, 2011 Kent Overstreet <[email protected]>
* Copyright 2012 Google, Inc.
*/
#include "bcache.h"
#include "btree.h"
#include "debug.h"
#include "extents.h"
#include <linux/console.h>
#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/seq_file.h>
struct dentry *bcache_debug;
#ifdef CONFIG_BCACHE_DEBUG
#define for_each_written_bset(b, start, i) \
for (i = (start); \
(void *) i < (void *) (start) + (KEY_SIZE(&b->key) << 9) &&\
i->seq == (start)->seq; \
i = (void *) i + set_blocks(i, block_bytes(b->c->cache)) * \
block_bytes(b->c->cache))
void bch_btree_verify(struct btree *b)
{
struct btree *v = b->c->verify_data;
struct bset *ondisk, *sorted, *inmemory;
struct bio *bio;
if (!b->c->verify || !b->c->verify_ondisk)
return;
down(&b->io_mutex);
mutex_lock(&b->c->verify_lock);
ondisk = b->c->verify_ondisk;
sorted = b->c->verify_data->keys.set->data;
inmemory = b->keys.set->data;
bkey_copy(&v->key, &b->key);
v->written = 0;
v->level = b->level;
v->keys.ops = b->keys.ops;
bio = bch_bbio_alloc(b->c);
bio_set_dev(bio, b->c->cache->bdev);
bio->bi_iter.bi_sector = PTR_OFFSET(&b->key, 0);
bio->bi_iter.bi_size = KEY_SIZE(&v->key) << 9;
bio->bi_opf = REQ_OP_READ | REQ_META;
bch_bio_map(bio, sorted);
submit_bio_wait(bio);
bch_bbio_free(bio, b->c);
memcpy(ondisk, sorted, KEY_SIZE(&v->key) << 9);
bch_btree_node_read_done(v);
sorted = v->keys.set->data;
if (inmemory->keys != sorted->keys ||
memcmp(inmemory->start,
sorted->start,
(void *) bset_bkey_last(inmemory) -
(void *) inmemory->start)) {
struct bset *i;
unsigned int j;
console_lock();
pr_err("*** in memory:\n");
bch_dump_bset(&b->keys, inmemory, 0);
pr_err("*** read back in:\n");
bch_dump_bset(&v->keys, sorted, 0);
for_each_written_bset(b, ondisk, i) {
unsigned int block = ((void *) i - (void *) ondisk) /
block_bytes(b->c->cache);
pr_err("*** on disk block %u:\n", block);
bch_dump_bset(&b->keys, i, block);
}
pr_err("*** block %zu not written\n",
((void *) i - (void *) ondisk) / block_bytes(b->c->cache));
for (j = 0; j < inmemory->keys; j++)
if (inmemory->d[j] != sorted->d[j])
break;
pr_err("b->written %u\n", b->written);
console_unlock();
panic("verify failed at %u\n", j);
}
mutex_unlock(&b->c->verify_lock);
up(&b->io_mutex);
}
void bch_data_verify(struct cached_dev *dc, struct bio *bio)
{
unsigned int nr_segs = bio_segments(bio);
struct bio *check;
struct bio_vec bv, cbv;
struct bvec_iter iter, citer = { 0 };
check = bio_kmalloc(nr_segs, GFP_NOIO);
if (!check)
return;
bio_init(check, bio->bi_bdev, check->bi_inline_vecs, nr_segs,
REQ_OP_READ);
check->bi_iter.bi_sector = bio->bi_iter.bi_sector;
check->bi_iter.bi_size = bio->bi_iter.bi_size;
bch_bio_map(check, NULL);
if (bch_bio_alloc_pages(check, GFP_NOIO))
goto out_put;
submit_bio_wait(check);
citer.bi_size = UINT_MAX;
bio_for_each_segment(bv, bio, iter) {
void *p1 = bvec_kmap_local(&bv);
void *p2;
cbv = bio_iter_iovec(check, citer);
p2 = bvec_kmap_local(&cbv);
cache_set_err_on(memcmp(p1, p2, bv.bv_len),
dc->disk.c,
"verify failed at dev %pg sector %llu",
dc->bdev,
(uint64_t) bio->bi_iter.bi_sector);
kunmap_local(p2);
kunmap_local(p1);
bio_advance_iter(check, &citer, bv.bv_len);
}
bio_free_pages(check);
out_put:
bio_uninit(check);
kfree(check);
}
#endif
#ifdef CONFIG_DEBUG_FS
/* XXX: cache set refcounting */
struct dump_iterator {
char buf[PAGE_SIZE];
size_t bytes;
struct cache_set *c;
struct keybuf keys;
};
static bool dump_pred(struct keybuf *buf, struct bkey *k)
{
return true;
}
static ssize_t bch_dump_read(struct file *file, char __user *buf,
size_t size, loff_t *ppos)
{
struct dump_iterator *i = file->private_data;
ssize_t ret = 0;
char kbuf[80];
while (size) {
struct keybuf_key *w;
unsigned int bytes = min(i->bytes, size);
if (copy_to_user(buf, i->buf, bytes))
return -EFAULT;
ret += bytes;
buf += bytes;
size -= bytes;
i->bytes -= bytes;
memmove(i->buf, i->buf + bytes, i->bytes);
if (i->bytes)
break;
w = bch_keybuf_next_rescan(i->c, &i->keys, &MAX_KEY, dump_pred);
if (!w)
break;
bch_extent_to_text(kbuf, sizeof(kbuf), &w->key);
i->bytes = snprintf(i->buf, PAGE_SIZE, "%s\n", kbuf);
bch_keybuf_del(&i->keys, w);
}
return ret;
}
static int bch_dump_open(struct inode *inode, struct file *file)
{
struct cache_set *c = inode->i_private;
struct dump_iterator *i;
i = kzalloc(sizeof(struct dump_iterator), GFP_KERNEL);
if (!i)
return -ENOMEM;
file->private_data = i;
i->c = c;
bch_keybuf_init(&i->keys);
i->keys.last_scanned = KEY(0, 0, 0);
return 0;
}
static int bch_dump_release(struct inode *inode, struct file *file)
{
kfree(file->private_data);
return 0;
}
static const struct file_operations cache_set_debug_ops = {
.owner = THIS_MODULE,
.open = bch_dump_open,
.read = bch_dump_read,
.release = bch_dump_release
};
void bch_debug_init_cache_set(struct cache_set *c)
{
if (!IS_ERR_OR_NULL(bcache_debug)) {
char name[50];
snprintf(name, 50, "bcache-%pU", c->set_uuid);
c->debug = debugfs_create_file(name, 0400, bcache_debug, c,
&cache_set_debug_ops);
}
}
#endif
void bch_debug_exit(void)
{
debugfs_remove_recursive(bcache_debug);
}
void __init bch_debug_init(void)
{
/*
* it is unnecessary to check return value of
* debugfs_create_file(), we should not care
* about this.
*/
bcache_debug = debugfs_create_dir("bcache", NULL);
}
| linux-master | drivers/md/bcache/debug.c |
// SPDX-License-Identifier: GPL-2.0
/*
* Feature set bits and string conversion.
* Inspired by ext4's features compat/incompat/ro_compat related code.
*
* Copyright 2020 Coly Li <[email protected]>
*
*/
#include "bcache_ondisk.h"
#include "bcache.h"
#include "features.h"
struct feature {
int compat;
unsigned int mask;
const char *string;
};
static struct feature feature_list[] = {
{BCH_FEATURE_INCOMPAT, BCH_FEATURE_INCOMPAT_LOG_LARGE_BUCKET_SIZE,
"large_bucket"},
{0, 0, NULL },
};
#define compose_feature_string(type) \
({ \
struct feature *f; \
bool first = true; \
\
for (f = &feature_list[0]; f->compat != 0; f++) { \
if (f->compat != BCH_FEATURE_ ## type) \
continue; \
if (BCH_HAS_ ## type ## _FEATURE(&c->cache->sb, f->mask)) { \
if (first) { \
out += snprintf(out, buf + size - out, \
"["); \
} else { \
out += snprintf(out, buf + size - out, \
" ["); \
} \
} else if (!first) { \
out += snprintf(out, buf + size - out, " "); \
} \
\
out += snprintf(out, buf + size - out, "%s", f->string);\
\
if (BCH_HAS_ ## type ## _FEATURE(&c->cache->sb, f->mask)) \
out += snprintf(out, buf + size - out, "]"); \
\
first = false; \
} \
if (!first) \
out += snprintf(out, buf + size - out, "\n"); \
})
int bch_print_cache_set_feature_compat(struct cache_set *c, char *buf, int size)
{
char *out = buf;
compose_feature_string(COMPAT);
return out - buf;
}
int bch_print_cache_set_feature_ro_compat(struct cache_set *c, char *buf, int size)
{
char *out = buf;
compose_feature_string(RO_COMPAT);
return out - buf;
}
int bch_print_cache_set_feature_incompat(struct cache_set *c, char *buf, int size)
{
char *out = buf;
compose_feature_string(INCOMPAT);
return out - buf;
}
| linux-master | drivers/md/bcache/features.c |
// SPDX-License-Identifier: GPL-2.0
/*
* Moving/copying garbage collector
*
* Copyright 2012 Google, Inc.
*/
#include "bcache.h"
#include "btree.h"
#include "debug.h"
#include "request.h"
#include <trace/events/bcache.h>
struct moving_io {
struct closure cl;
struct keybuf_key *w;
struct data_insert_op op;
struct bbio bio;
};
static bool moving_pred(struct keybuf *buf, struct bkey *k)
{
struct cache_set *c = container_of(buf, struct cache_set,
moving_gc_keys);
unsigned int i;
for (i = 0; i < KEY_PTRS(k); i++)
if (ptr_available(c, k, i) &&
GC_MOVE(PTR_BUCKET(c, k, i)))
return true;
return false;
}
/* Moving GC - IO loop */
static void moving_io_destructor(struct closure *cl)
{
struct moving_io *io = container_of(cl, struct moving_io, cl);
kfree(io);
}
static void write_moving_finish(struct closure *cl)
{
struct moving_io *io = container_of(cl, struct moving_io, cl);
struct bio *bio = &io->bio.bio;
bio_free_pages(bio);
if (io->op.replace_collision)
trace_bcache_gc_copy_collision(&io->w->key);
bch_keybuf_del(&io->op.c->moving_gc_keys, io->w);
up(&io->op.c->moving_in_flight);
closure_return_with_destructor(cl, moving_io_destructor);
}
static void read_moving_endio(struct bio *bio)
{
struct bbio *b = container_of(bio, struct bbio, bio);
struct moving_io *io = container_of(bio->bi_private,
struct moving_io, cl);
if (bio->bi_status)
io->op.status = bio->bi_status;
else if (!KEY_DIRTY(&b->key) &&
ptr_stale(io->op.c, &b->key, 0)) {
io->op.status = BLK_STS_IOERR;
}
bch_bbio_endio(io->op.c, bio, bio->bi_status, "reading data to move");
}
static void moving_init(struct moving_io *io)
{
struct bio *bio = &io->bio.bio;
bio_init(bio, NULL, bio->bi_inline_vecs,
DIV_ROUND_UP(KEY_SIZE(&io->w->key), PAGE_SECTORS), 0);
bio_get(bio);
bio_set_prio(bio, IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0));
bio->bi_iter.bi_size = KEY_SIZE(&io->w->key) << 9;
bio->bi_private = &io->cl;
bch_bio_map(bio, NULL);
}
static void write_moving(struct closure *cl)
{
struct moving_io *io = container_of(cl, struct moving_io, cl);
struct data_insert_op *op = &io->op;
if (!op->status) {
moving_init(io);
io->bio.bio.bi_iter.bi_sector = KEY_START(&io->w->key);
op->write_prio = 1;
op->bio = &io->bio.bio;
op->writeback = KEY_DIRTY(&io->w->key);
op->csum = KEY_CSUM(&io->w->key);
bkey_copy(&op->replace_key, &io->w->key);
op->replace = true;
closure_call(&op->cl, bch_data_insert, NULL, cl);
}
continue_at(cl, write_moving_finish, op->wq);
}
static void read_moving_submit(struct closure *cl)
{
struct moving_io *io = container_of(cl, struct moving_io, cl);
struct bio *bio = &io->bio.bio;
bch_submit_bbio(bio, io->op.c, &io->w->key, 0);
continue_at(cl, write_moving, io->op.wq);
}
static void read_moving(struct cache_set *c)
{
struct keybuf_key *w;
struct moving_io *io;
struct bio *bio;
struct closure cl;
closure_init_stack(&cl);
/* XXX: if we error, background writeback could stall indefinitely */
while (!test_bit(CACHE_SET_STOPPING, &c->flags)) {
w = bch_keybuf_next_rescan(c, &c->moving_gc_keys,
&MAX_KEY, moving_pred);
if (!w)
break;
if (ptr_stale(c, &w->key, 0)) {
bch_keybuf_del(&c->moving_gc_keys, w);
continue;
}
io = kzalloc(struct_size(io, bio.bio.bi_inline_vecs,
DIV_ROUND_UP(KEY_SIZE(&w->key), PAGE_SECTORS)),
GFP_KERNEL);
if (!io)
goto err;
w->private = io;
io->w = w;
io->op.inode = KEY_INODE(&w->key);
io->op.c = c;
io->op.wq = c->moving_gc_wq;
moving_init(io);
bio = &io->bio.bio;
bio->bi_opf = REQ_OP_READ;
bio->bi_end_io = read_moving_endio;
if (bch_bio_alloc_pages(bio, GFP_KERNEL))
goto err;
trace_bcache_gc_copy(&w->key);
down(&c->moving_in_flight);
closure_call(&io->cl, read_moving_submit, NULL, &cl);
}
if (0) {
err: if (!IS_ERR_OR_NULL(w->private))
kfree(w->private);
bch_keybuf_del(&c->moving_gc_keys, w);
}
closure_sync(&cl);
}
static bool bucket_cmp(struct bucket *l, struct bucket *r)
{
return GC_SECTORS_USED(l) < GC_SECTORS_USED(r);
}
static unsigned int bucket_heap_top(struct cache *ca)
{
struct bucket *b;
return (b = heap_peek(&ca->heap)) ? GC_SECTORS_USED(b) : 0;
}
void bch_moving_gc(struct cache_set *c)
{
struct cache *ca = c->cache;
struct bucket *b;
unsigned long sectors_to_move, reserve_sectors;
if (!c->copy_gc_enabled)
return;
mutex_lock(&c->bucket_lock);
sectors_to_move = 0;
reserve_sectors = ca->sb.bucket_size *
fifo_used(&ca->free[RESERVE_MOVINGGC]);
ca->heap.used = 0;
for_each_bucket(b, ca) {
if (GC_MARK(b) == GC_MARK_METADATA ||
!GC_SECTORS_USED(b) ||
GC_SECTORS_USED(b) == ca->sb.bucket_size ||
atomic_read(&b->pin))
continue;
if (!heap_full(&ca->heap)) {
sectors_to_move += GC_SECTORS_USED(b);
heap_add(&ca->heap, b, bucket_cmp);
} else if (bucket_cmp(b, heap_peek(&ca->heap))) {
sectors_to_move -= bucket_heap_top(ca);
sectors_to_move += GC_SECTORS_USED(b);
ca->heap.data[0] = b;
heap_sift(&ca->heap, 0, bucket_cmp);
}
}
while (sectors_to_move > reserve_sectors) {
heap_pop(&ca->heap, b, bucket_cmp);
sectors_to_move -= GC_SECTORS_USED(b);
}
while (heap_pop(&ca->heap, b, bucket_cmp))
SET_GC_MOVE(b, 1);
mutex_unlock(&c->bucket_lock);
c->moving_gc_keys.last_scanned = ZERO_KEY;
read_moving(c);
}
void bch_moving_init_cache_set(struct cache_set *c)
{
bch_keybuf_init(&c->moving_gc_keys);
sema_init(&c->moving_in_flight, 64);
}
| linux-master | drivers/md/bcache/movinggc.c |
/*
* DIO Driver Services
*
* Copyright (C) 2004 Jochen Friedrich
*
* Loosely based on drivers/pci/pci-driver.c and drivers/zorro/zorro-driver.c
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive
* for more details.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/dio.h>
/**
* dio_match_device - Tell if a DIO device structure has a matching DIO device id structure
* @ids: array of DIO device id structures to search in
* @d: the DIO device structure to match against
*
* Used by a driver to check whether a DIO device present in the
* system is in its list of supported devices. Returns the matching
* dio_device_id structure or %NULL if there is no match.
*/
static const struct dio_device_id *
dio_match_device(const struct dio_device_id *ids,
const struct dio_dev *d)
{
while (ids->id) {
if (ids->id == DIO_WILDCARD)
return ids;
if (DIO_NEEDSSECID(ids->id & 0xff)) {
if (ids->id == d->id)
return ids;
} else {
if ((ids->id & 0xff) == (d->id & 0xff))
return ids;
}
ids++;
}
return NULL;
}
static int dio_device_probe(struct device *dev)
{
int error = 0;
struct dio_driver *drv = to_dio_driver(dev->driver);
struct dio_dev *d = to_dio_dev(dev);
if (!d->driver && drv->probe) {
const struct dio_device_id *id;
id = dio_match_device(drv->id_table, d);
if (id)
error = drv->probe(d, id);
if (error >= 0) {
d->driver = drv;
error = 0;
}
}
return error;
}
/**
* dio_register_driver - register a new DIO driver
* @drv: the driver structure to register
*
* Adds the driver structure to the list of registered drivers
* Returns zero or a negative error value.
*/
int dio_register_driver(struct dio_driver *drv)
{
/* initialize common driver fields */
drv->driver.name = drv->name;
drv->driver.bus = &dio_bus_type;
/* register with core */
return driver_register(&drv->driver);
}
/**
* dio_unregister_driver - unregister a DIO driver
* @drv: the driver structure to unregister
*
* Deletes the driver structure from the list of registered DIO drivers,
* gives it a chance to clean up by calling its remove() function for
* each device it was responsible for, and marks those devices as
* driverless.
*/
void dio_unregister_driver(struct dio_driver *drv)
{
driver_unregister(&drv->driver);
}
/**
* dio_bus_match - Tell if a DIO device structure has a matching DIO device id structure
* @dev: the DIO device structure to match against
* @drv: the &device_driver that points to the array of DIO device id structures to search
*
* Used by the driver core to check whether a DIO device present in the
* system is in a driver's list of supported devices. Returns 1 if supported,
* and 0 if there is no match.
*/
static int dio_bus_match(struct device *dev, struct device_driver *drv)
{
struct dio_dev *d = to_dio_dev(dev);
struct dio_driver *dio_drv = to_dio_driver(drv);
const struct dio_device_id *ids = dio_drv->id_table;
if (!ids)
return 0;
return dio_match_device(ids, d) ? 1 : 0;
}
struct bus_type dio_bus_type = {
.name = "dio",
.match = dio_bus_match,
.probe = dio_device_probe,
};
static int __init dio_driver_init(void)
{
return bus_register(&dio_bus_type);
}
postcore_initcall(dio_driver_init);
EXPORT_SYMBOL(dio_register_driver);
EXPORT_SYMBOL(dio_unregister_driver);
EXPORT_SYMBOL(dio_bus_type);
| linux-master | drivers/dio/dio-driver.c |
// SPDX-License-Identifier: GPL-2.0
/* Code to support devices on the DIO and DIO-II bus
* Copyright (C) 05/1998 Peter Maydell <[email protected]>
* Copyright (C) 2004 Jochen Friedrich <[email protected]>
*
* This code has basically these routines at the moment:
* int dio_find(u_int deviceid)
* Search the list of DIO devices and return the select code
* of the next unconfigured device found that matches the given device ID.
* Note that the deviceid parameter should be the encoded ID.
* This means that framebuffers should pass it as
* DIO_ENCODE_ID(DIO_ID_FBUFFER,DIO_ID2_TOPCAT)
* (or whatever); everybody else just uses DIO_ID_FOOBAR.
* unsigned long dio_scodetophysaddr(int scode)
* Return the physical address corresponding to the given select code.
* int dio_scodetoipl(int scode)
* Every DIO card has a fixed interrupt priority level. This function
* returns it, whatever it is.
* const char *dio_scodetoname(int scode)
* Return a character string describing this board [might be "" if
* not CONFIG_DIO_CONSTANTS]
* void dio_config_board(int scode) mark board as configured in the list
* void dio_unconfig_board(int scode) mark board as no longer configured
*
* This file is based on the way the Amiga port handles Zorro II cards,
* although we aren't so complicated...
*/
#include <linux/module.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/dio.h>
#include <linux/slab.h> /* kmalloc() */
#include <linux/uaccess.h>
#include <linux/io.h> /* readb() */
struct dio_bus dio_bus = {
.resources = {
/* DIO range */
{ .name = "DIO mem", .start = 0x00600000, .end = 0x007fffff },
/* DIO-II range */
{ .name = "DIO-II mem", .start = 0x01000000, .end = 0x1fffffff }
},
.name = "DIO bus"
};
/* not a real config option yet! */
#define CONFIG_DIO_CONSTANTS
#ifdef CONFIG_DIO_CONSTANTS
/* We associate each numeric ID with an appropriate descriptive string
* using a constant array of these structs.
* FIXME: we should be able to arrange to throw away most of the strings
* using the initdata stuff. Then we wouldn't need to worry about
* carrying them around...
* I think we do this by copying them into newly kmalloc()ed memory and
* marking the names[] array as .initdata ?
*/
struct dioname {
int id;
const char *name;
};
/* useful macro */
#define DIONAME(x) { DIO_ID_##x, DIO_DESC_##x }
#define DIOFBNAME(x) { DIO_ENCODE_ID(DIO_ID_FBUFFER, DIO_ID2_##x), DIO_DESC2_##x }
static struct dioname names[] = {
DIONAME(DCA0), DIONAME(DCA0REM), DIONAME(DCA1), DIONAME(DCA1REM),
DIONAME(DCM), DIONAME(DCMREM),
DIONAME(LAN),
DIONAME(FHPIB), DIONAME(NHPIB),
DIONAME(SCSI0), DIONAME(SCSI1), DIONAME(SCSI2), DIONAME(SCSI3),
DIONAME(FBUFFER),
DIONAME(PARALLEL), DIONAME(VME), DIONAME(DCL), DIONAME(DCLREM),
DIONAME(MISC0), DIONAME(MISC1), DIONAME(MISC2), DIONAME(MISC3),
DIONAME(MISC4), DIONAME(MISC5), DIONAME(MISC6), DIONAME(MISC7),
DIONAME(MISC8), DIONAME(MISC9), DIONAME(MISC10), DIONAME(MISC11),
DIONAME(MISC12), DIONAME(MISC13),
DIOFBNAME(GATORBOX), DIOFBNAME(TOPCAT), DIOFBNAME(RENAISSANCE),
DIOFBNAME(LRCATSEYE), DIOFBNAME(HRCCATSEYE), DIOFBNAME(HRMCATSEYE),
DIOFBNAME(DAVINCI), DIOFBNAME(XXXCATSEYE), DIOFBNAME(HYPERION),
DIOFBNAME(XGENESIS), DIOFBNAME(TIGER), DIOFBNAME(YGENESIS)
};
#undef DIONAME
#undef DIOFBNAME
static const char unknowndioname[]
= "unknown DIO board, please email [email protected]";
static const char *dio_getname(int id)
{
/* return pointer to a constant string describing the board with given ID */
unsigned int i;
for (i = 0; i < ARRAY_SIZE(names); i++)
if (names[i].id == id)
return names[i].name;
return unknowndioname;
}
#else
static char dio_no_name[] = { 0 };
#define dio_getname(_id) (dio_no_name)
#endif /* CONFIG_DIO_CONSTANTS */
static void dio_dev_release(struct device *dev)
{
struct dio_dev *ddev = container_of(dev, typeof(struct dio_dev), dev);
kfree(ddev);
}
int __init dio_find(int deviceid)
{
/* Called to find a DIO device before the full bus scan has run.
* Only used by the console driver.
*/
int scode, id;
u_char prid, secid, i;
for (scode = 0; scode < DIO_SCMAX; scode++) {
void *va;
unsigned long pa;
if (DIO_SCINHOLE(scode))
continue;
pa = dio_scodetophysaddr(scode);
if (!pa)
continue;
if (scode < DIOII_SCBASE)
va = (void *)(pa + DIO_VIRADDRBASE);
else
va = ioremap(pa, PAGE_SIZE);
if (copy_from_kernel_nofault(&i,
(unsigned char *)va + DIO_IDOFF, 1)) {
if (scode >= DIOII_SCBASE)
iounmap(va);
continue; /* no board present at that select code */
}
prid = DIO_ID(va);
if (DIO_NEEDSSECID(prid)) {
secid = DIO_SECID(va);
id = DIO_ENCODE_ID(prid, secid);
} else
id = prid;
if (id == deviceid) {
if (scode >= DIOII_SCBASE)
iounmap(va);
return scode;
}
}
return -1;
}
/* This is the function that scans the DIO space and works out what
* hardware is actually present.
*/
static int __init dio_init(void)
{
int scode;
int i;
struct dio_dev *dev;
int error;
if (!MACH_IS_HP300)
return 0;
printk(KERN_INFO "Scanning for DIO devices...\n");
/* Initialize the DIO bus */
INIT_LIST_HEAD(&dio_bus.devices);
dev_set_name(&dio_bus.dev, "dio");
error = device_register(&dio_bus.dev);
if (error) {
pr_err("DIO: Error registering dio_bus\n");
return error;
}
/* Request all resources */
dio_bus.num_resources = (hp300_model == HP_320 ? 1 : 2);
for (i = 0; i < dio_bus.num_resources; i++)
request_resource(&iomem_resource, &dio_bus.resources[i]);
/* Register all devices */
for (scode = 0; scode < DIO_SCMAX; ++scode) {
u_char prid, secid = 0; /* primary, secondary ID bytes */
u_char *va;
unsigned long pa;
if (DIO_SCINHOLE(scode))
continue;
pa = dio_scodetophysaddr(scode);
if (!pa)
continue;
if (scode < DIOII_SCBASE)
va = (void *)(pa + DIO_VIRADDRBASE);
else
va = ioremap(pa, PAGE_SIZE);
if (copy_from_kernel_nofault(&i,
(unsigned char *)va + DIO_IDOFF, 1)) {
if (scode >= DIOII_SCBASE)
iounmap(va);
continue; /* no board present at that select code */
}
/* Found a board, allocate it an entry in the list */
dev = kzalloc(sizeof(struct dio_dev), GFP_KERNEL);
if (!dev) {
if (scode >= DIOII_SCBASE)
iounmap(va);
return -ENOMEM;
}
dev->bus = &dio_bus;
dev->dev.parent = &dio_bus.dev;
dev->dev.bus = &dio_bus_type;
dev->dev.release = dio_dev_release;
dev->scode = scode;
dev->resource.start = pa;
dev->resource.end = pa + DIO_SIZE(scode, va);
dev_set_name(&dev->dev, "%02x", scode);
/* read the ID byte(s) and encode if necessary. */
prid = DIO_ID(va);
if (DIO_NEEDSSECID(prid)) {
secid = DIO_SECID(va);
dev->id = DIO_ENCODE_ID(prid, secid);
} else
dev->id = prid;
dev->ipl = DIO_IPL(va);
strcpy(dev->name, dio_getname(dev->id));
printk(KERN_INFO "select code %3d: ipl %d: ID %02X", dev->scode, dev->ipl, prid);
if (DIO_NEEDSSECID(prid))
printk(":%02X", secid);
printk(": %s\n", dev->name);
if (scode >= DIOII_SCBASE)
iounmap(va);
error = device_register(&dev->dev);
if (error) {
pr_err("DIO: Error registering device %s\n",
dev->name);
put_device(&dev->dev);
continue;
}
error = dio_create_sysfs_dev_files(dev);
if (error)
dev_err(&dev->dev, "Error creating sysfs files\n");
}
return 0;
}
subsys_initcall(dio_init);
/* Bear in mind that this is called in the very early stages of initialisation
* in order to get the address of the serial port for the console...
*/
unsigned long dio_scodetophysaddr(int scode)
{
if (scode >= DIOII_SCBASE)
return (DIOII_BASE + (scode - 132) * DIOII_DEVSIZE);
else if (scode > DIO_SCMAX || scode < 0)
return 0;
else if (DIO_SCINHOLE(scode))
return 0;
return (DIO_BASE + scode * DIO_DEVSIZE);
}
| linux-master | drivers/dio/dio.c |
/*
* File Attributes for DIO Devices
*
* Copyright (C) 2004 Jochen Friedrich
*
* Loosely based on drivers/pci/pci-sysfs.c and drivers/zorro/zorro-sysfs.c
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive
* for more details.
*/
#include <linux/kernel.h>
#include <linux/dio.h>
#include <linux/stat.h>
/* show configuration fields */
static ssize_t dio_show_id(struct device *dev, struct device_attribute *attr, char *buf)
{
struct dio_dev *d;
d = to_dio_dev(dev);
return sprintf(buf, "0x%02x\n", (d->id & 0xff));
}
static DEVICE_ATTR(id, S_IRUGO, dio_show_id, NULL);
static ssize_t dio_show_ipl(struct device *dev, struct device_attribute *attr, char *buf)
{
struct dio_dev *d;
d = to_dio_dev(dev);
return sprintf(buf, "0x%02x\n", d->ipl);
}
static DEVICE_ATTR(ipl, S_IRUGO, dio_show_ipl, NULL);
static ssize_t dio_show_secid(struct device *dev, struct device_attribute *attr, char *buf)
{
struct dio_dev *d;
d = to_dio_dev(dev);
return sprintf(buf, "0x%02x\n", ((d->id >> 8)& 0xff));
}
static DEVICE_ATTR(secid, S_IRUGO, dio_show_secid, NULL);
static ssize_t dio_show_name(struct device *dev, struct device_attribute *attr, char *buf)
{
struct dio_dev *d;
d = to_dio_dev(dev);
return sprintf(buf, "%s\n", d->name);
}
static DEVICE_ATTR(name, S_IRUGO, dio_show_name, NULL);
static ssize_t dio_show_resource(struct device *dev, struct device_attribute *attr, char *buf)
{
struct dio_dev *d = to_dio_dev(dev);
return sprintf(buf, "0x%08lx 0x%08lx 0x%08lx\n",
(unsigned long)dio_resource_start(d),
(unsigned long)dio_resource_end(d),
dio_resource_flags(d));
}
static DEVICE_ATTR(resource, S_IRUGO, dio_show_resource, NULL);
int dio_create_sysfs_dev_files(struct dio_dev *d)
{
struct device *dev = &d->dev;
int error;
/* current configuration's attributes */
if ((error = device_create_file(dev, &dev_attr_id)) ||
(error = device_create_file(dev, &dev_attr_ipl)) ||
(error = device_create_file(dev, &dev_attr_secid)) ||
(error = device_create_file(dev, &dev_attr_name)) ||
(error = device_create_file(dev, &dev_attr_resource)))
return error;
return 0;
}
| linux-master | drivers/dio/dio-sysfs.c |
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