text: /*
   * Copyright (c) International Business Machines Corp., 2006
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation;  either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
   * the GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   *
   * Author: Artem Bityutskiy (Битюцкий Артём)
   */
  
  /*
   * This file contains implementation of volume creation, deletion, updating and
   * resizing.
   */
  
  #ifdef UBI_LINUX
  #include <linux/err.h>
  #include <asm/div64.h>
  #endif
  
  #include <ubi_uboot.h>
  #include "ubi.h"
  
  #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
  static void paranoid_check_volumes(struct ubi_device *ubi);
  #else
  #define paranoid_check_volumes(ubi)
  #endif
  
  #ifdef UBI_LINUX
  static ssize_t vol_attribute_show(struct device *dev,
  				  struct device_attribute *attr, char *buf);
  
  /* Device attributes corresponding to files in '/<sysfs>/class/ubi/ubiX_Y' */
  static struct device_attribute attr_vol_reserved_ebs =
  	__ATTR(reserved_ebs, S_IRUGO, vol_attribute_show, NULL);
  static struct device_attribute attr_vol_type =
  	__ATTR(type, S_IRUGO, vol_attribute_show, NULL);
  static struct device_attribute attr_vol_name =
  	__ATTR(name, S_IRUGO, vol_attribute_show, NULL);
  static struct device_attribute attr_vol_corrupted =
  	__ATTR(corrupted, S_IRUGO, vol_attribute_show, NULL);
  static struct device_attribute attr_vol_alignment =
  	__ATTR(alignment, S_IRUGO, vol_attribute_show, NULL);
  static struct device_attribute attr_vol_usable_eb_size =
  	__ATTR(usable_eb_size, S_IRUGO, vol_attribute_show, NULL);
  static struct device_attribute attr_vol_data_bytes =
  	__ATTR(data_bytes, S_IRUGO, vol_attribute_show, NULL);
  static struct device_attribute attr_vol_upd_marker =
  	__ATTR(upd_marker, S_IRUGO, vol_attribute_show, NULL);
  
  /*
   * "Show" method for files in '/<sysfs>/class/ubi/ubiX_Y/'.
   *
   * Consider a situation:
   * A. process 1 opens a sysfs file related to volume Y, say
   *    /<sysfs>/class/ubi/ubiX_Y/reserved_ebs;
   * B. process 2 removes volume Y;
   * C. process 1 starts reading the /<sysfs>/class/ubi/ubiX_Y/reserved_ebs file;
   *
   * In this situation, this function will return %-ENODEV because it will find
   * out that the volume was removed from the @ubi->volumes array.
   */
  static ssize_t vol_attribute_show(struct device *dev,
  				  struct device_attribute *attr, char *buf)
  {
  	int ret;
  	struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);
  	struct ubi_device *ubi;
  
  	ubi = ubi_get_device(vol->ubi->ubi_num);
  	if (!ubi)
  		return -ENODEV;
  
  	spin_lock(&ubi->volumes_lock);
  	if (!ubi->volumes[vol->vol_id]) {
  		spin_unlock(&ubi->volumes_lock);
  		ubi_put_device(ubi);
  		return -ENODEV;
  	}
  	/* Take a reference to prevent volume removal */
  	vol->ref_count += 1;
  	spin_unlock(&ubi->volumes_lock);
  
  	if (attr == &attr_vol_reserved_ebs)
  		ret = sprintf(buf, "%d\n", vol->reserved_pebs);
  	else if (attr == &attr_vol_type) {
  		const char *tp;
  
  		if (vol->vol_type == UBI_DYNAMIC_VOLUME)
  			tp = "dynamic";
  		else
  			tp = "static";
  		ret = sprintf(buf, "%s\n", tp);
  	} else if (attr == &attr_vol_name)
  		ret = sprintf(buf, "%s\n", vol->name);
  	else if (attr == &attr_vol_corrupted)
  		ret = sprintf(buf, "%d\n", vol->corrupted);
  	else if (attr == &attr_vol_alignment)
  		ret = sprintf(buf, "%d\n", vol->alignment);
  	else if (attr == &attr_vol_usable_eb_size)
  		ret = sprintf(buf, "%d\n", vol->usable_leb_size);
  	else if (attr == &attr_vol_data_bytes)
  		ret = sprintf(buf, "%lld\n", vol->used_bytes);
  	else if (attr == &attr_vol_upd_marker)
  		ret = sprintf(buf, "%d\n", vol->upd_marker);
  	else
  		/* This must be a bug */
  		ret = -EINVAL;
  
  	/* We've done the operation, drop volume and UBI device references */
  	spin_lock(&ubi->volumes_lock);
  	vol->ref_count -= 1;
  	ubi_assert(vol->ref_count >= 0);
  	spin_unlock(&ubi->volumes_lock);
  	ubi_put_device(ubi);
  	return ret;
  }
  #endif
  
  /* Release method for volume devices */
  static void vol_release(struct device *dev)
  {
  	struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);
  
  	kfree(vol);
  }
  
  #ifdef UBI_LINUX
  /**
   * volume_sysfs_init - initialize sysfs for new volume.
   * @ubi: UBI device description object
   * @vol: volume description object
   *
   * This function returns zero in case of success and a negative error code in
   * case of failure.
   *
   * Note, this function does not free allocated resources in case of failure -
   * the caller does it. This is because this would cause release() here and the
   * caller would oops.
   */
  static int volume_sysfs_init(struct ubi_device *ubi, struct ubi_volume *vol)
  {
  	int err;
  
  	err = device_create_file(&vol->dev, &attr_vol_reserved_ebs);
  	if (err)
  		return err;
  	err = device_create_file(&vol->dev, &attr_vol_type);
  	if (err)
  		return err;
  	err = device_create_file(&vol->dev, &attr_vol_name);
  	if (err)
  		return err;
  	err = device_create_file(&vol->dev, &attr_vol_corrupted);
  	if (err)
  		return err;
  	err = device_create_file(&vol->dev, &attr_vol_alignment);
  	if (err)
  		return err;
  	err = device_create_file(&vol->dev, &attr_vol_usable_eb_size);
  	if (err)
  		return err;
  	err = device_create_file(&vol->dev, &attr_vol_data_bytes);
  	if (err)
  		return err;
  	err = device_create_file(&vol->dev, &attr_vol_upd_marker);
  	return err;
  }
  
  /**
   * volume_sysfs_close - close sysfs for a volume.
   * @vol: volume description object
   */
  static void volume_sysfs_close(struct ubi_volume *vol)
  {
  	device_remove_file(&vol->dev, &attr_vol_upd_marker);
  	device_remove_file(&vol->dev, &attr_vol_data_bytes);
  	device_remove_file(&vol->dev, &attr_vol_usable_eb_size);
  	device_remove_file(&vol->dev, &attr_vol_alignment);
  	device_remove_file(&vol->dev, &attr_vol_corrupted);
  	device_remove_file(&vol->dev, &attr_vol_name);
  	device_remove_file(&vol->dev, &attr_vol_type);
  	device_remove_file(&vol->dev, &attr_vol_reserved_ebs);
  	device_unregister(&vol->dev);
  }
  #endif
  
  /**
   * ubi_create_volume - create volume.
   * @ubi: UBI device description object
   * @req: volume creation request
   *
   * This function creates volume described by @req. If @req->vol_id id
   * %UBI_VOL_NUM_AUTO, this function automatically assign ID to the new volume
   * and saves it in @req->vol_id. Returns zero in case of success and a negative
   * error code in case of failure. Note, the caller has to have the
   * @ubi->volumes_mutex locked.
   */
  int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
  {
  	int i, err, vol_id = req->vol_id, dont_free = 0;
  	struct ubi_volume *vol;
  	struct ubi_vtbl_record vtbl_rec;
  	uint64_t bytes;
  	dev_t dev;
  
  	if (ubi->ro_mode)
  		return -EROFS;
  
  	vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL);
  	if (!vol)
  		return -ENOMEM;
  
  	spin_lock(&ubi->volumes_lock);
  	if (vol_id == UBI_VOL_NUM_AUTO) {
  		/* Find unused volume ID */
  		dbg_msg("search for vacant volume ID");
  		for (i = 0; i < ubi->vtbl_slots; i++)
  			if (!ubi->volumes[i]) {
  				vol_id = i;
  				break;
  			}
  
  		if (vol_id == UBI_VOL_NUM_AUTO) {
  			dbg_err("out of volume IDs");
  			err = -ENFILE;
  			goto out_unlock;
  		}
  		req->vol_id = vol_id;
  	}
  
  	dbg_msg("volume ID %d, %llu bytes, type %d, name %s",
  		vol_id, (unsigned long long)req->bytes,
  		(int)req->vol_type, req->name);
  
  	/* Ensure that this volume does not exist */
  	err = -EEXIST;
  	if (ubi->volumes[vol_id]) {
  		dbg_err("volume %d already exists", vol_id);
  		goto out_unlock;
  	}
  
  	/* Ensure that the name is unique */
  	for (i = 0; i < ubi->vtbl_slots; i++)
  		if (ubi->volumes[i] &&
  		    ubi->volumes[i]->name_len == req->name_len &&
  		    !strcmp(ubi->volumes[i]->name, req->name)) {
  			dbg_err("volume \"%s\" exists (ID %d)", req->name, i);
  			goto out_unlock;
  		}
  
  	/* Calculate how many eraseblocks are requested */
  	vol->usable_leb_size = ubi->leb_size - ubi->leb_size % req->alignment;
  	bytes = req->bytes;
  	if (do_div(bytes, vol->usable_leb_size))
  		vol->reserved_pebs = 1;
  	vol->reserved_pebs += bytes;
  
  	/* Reserve physical eraseblocks */
  	if (vol->reserved_pebs > ubi->avail_pebs) {
  		dbg_err("not enough PEBs, only %d available", ubi->avail_pebs);
  		err = -ENOSPC;
  		goto out_unlock;
  	}
  	ubi->avail_pebs -= vol->reserved_pebs;
  	ubi->rsvd_pebs += vol->reserved_pebs;
  	spin_unlock(&ubi->volumes_lock);
  
  	vol->vol_id    = vol_id;
  	vol->alignment = req->alignment;
  	vol->data_pad  = ubi->leb_size % vol->alignment;
  	vol->vol_type  = req->vol_type;
  	vol->name_len  = req->name_len;
  	memcpy(vol->name, req->name, vol->name_len + 1);
  	vol->ubi = ubi;
  
  	/*
  	 * Finish all pending erases because there may be some LEBs belonging
  	 * to the same volume ID.
  	 */
  	err = ubi_wl_flush(ubi);
  	if (err)
  		goto out_acc;
  
  	vol->eba_tbl = kmalloc(vol->reserved_pebs * sizeof(int), GFP_KERNEL);
  	if (!vol->eba_tbl) {
  		err = -ENOMEM;
  		goto out_acc;
  	}
  
  	for (i = 0; i < vol->reserved_pebs; i++)
  		vol->eba_tbl[i] = UBI_LEB_UNMAPPED;
  
  	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
  		vol->used_ebs = vol->reserved_pebs;
  		vol->last_eb_bytes = vol->usable_leb_size;
  		vol->used_bytes =
  			(long long)vol->used_ebs * vol->usable_leb_size;
  	} else {
  		bytes = vol->used_bytes;
  		vol->last_eb_bytes = do_div(bytes, vol->usable_leb_size);
  		vol->used_ebs = bytes;
  		if (vol->last_eb_bytes)
  			vol->used_ebs += 1;
  		else
  			vol->last_eb_bytes = vol->usable_leb_size;
  	}
  
  	/* Register character device for the volume */
  	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
  	vol->cdev.owner = THIS_MODULE;
  	dev = MKDEV(MAJOR(ubi->cdev.dev), vol_id + 1);
  	err = cdev_add(&vol->cdev, dev, 1);
  	if (err) {
  		ubi_err("cannot add character device");
  		goto out_mapping;
  	}
  
  	err = ubi_create_gluebi(ubi, vol);
  	if (err)
  		goto out_cdev;
  
  	vol->dev.release = vol_release;
  	vol->dev.parent = &ubi->dev;
  	vol->dev.devt = dev;
  	vol->dev.class = ubi_class;
  
  	sprintf(&vol->dev.bus_id[0], "%s_%d", ubi->ubi_name, vol->vol_id);
  	err = device_register(&vol->dev);
  	if (err) {
  		ubi_err("cannot register device");
  		goto out_gluebi;
  	}
  
  	err = volume_sysfs_init(ubi, vol);
  	if (err)
  		goto out_sysfs;
  
  	/* Fill volume table record */
  	memset(&vtbl_rec, 0, sizeof(struct ubi_vtbl_record));
  	vtbl_rec.reserved_pebs = cpu_to_be32(vol->reserved_pebs);
  	vtbl_rec.alignment     = cpu_to_be32(vol->alignment);
  	vtbl_rec.data_pad      = cpu_to_be32(vol->data_pad);
  	vtbl_rec.name_len      = cpu_to_be16(vol->name_len);
  	if (vol->vol_type == UBI_DYNAMIC_VOLUME)
  		vtbl_rec.vol_type = UBI_VID_DYNAMIC;
  	else
  		vtbl_rec.vol_type = UBI_VID_STATIC;
  	memcpy(vtbl_rec.name, vol->name, vol->name_len + 1);
  
  	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
  	if (err)
  		goto out_sysfs;
  
  	spin_lock(&ubi->volumes_lock);
  	ubi->volumes[vol_id] = vol;
  	ubi->vol_count += 1;
  	spin_unlock(&ubi->volumes_lock);
  
  	paranoid_check_volumes(ubi);
  	return 0;
  
  out_sysfs:
  	/*
  	 * We have registered our device, we should not free the volume*
  	 * description object in this function in case of an error - it is
  	 * freed by the release function.
  	 *
  	 * Get device reference to prevent the release function from being
  	 * called just after sysfs has been closed.
  	 */
  	dont_free = 1;
  	get_device(&vol->dev);
  	volume_sysfs_close(vol);
  out_gluebi:
  	if (ubi_destroy_gluebi(vol))
  		dbg_err("cannot destroy gluebi for volume %d:%d",
  			ubi->ubi_num, vol_id);
  out_cdev:
  	cdev_del(&vol->cdev);
  out_mapping:
  	kfree(vol->eba_tbl);
  out_acc:
  	spin_lock(&ubi->volumes_lock);
  	ubi->rsvd_pebs -= vol->reserved_pebs;
  	ubi->avail_pebs += vol->reserved_pebs;
  out_unlock:
  	spin_unlock(&ubi->volumes_lock);
  	if (dont_free)
  		put_device(&vol->dev);
  	else
  		kfree(vol);
  	ubi_err("cannot create volume %d, error %d", vol_id, err);
  	return err;
  }
  
  /**
   * ubi_remove_volume - remove volume.
   * @desc: volume descriptor
   *
   * This function removes volume described by @desc. The volume has to be opened
   * in "exclusive" mode. Returns zero in case of success and a negative error
   * code in case of failure. The caller has to have the @ubi->volumes_mutex
   * locked.
   */
  int ubi_remove_volume(struct ubi_volume_desc *desc)
  {
  	struct ubi_volume *vol = desc->vol;
  	struct ubi_device *ubi = vol->ubi;
  	int i, err, vol_id = vol->vol_id, reserved_pebs = vol->reserved_pebs;
  
  	dbg_msg("remove UBI volume %d", vol_id);
  	ubi_assert(desc->mode == UBI_EXCLUSIVE);
  	ubi_assert(vol == ubi->volumes[vol_id]);
  
  	if (ubi->ro_mode)
  		return -EROFS;
  
  	spin_lock(&ubi->volumes_lock);
  	if (vol->ref_count > 1) {
  		/*
  		 * The volume is busy, probably someone is reading one of its
  		 * sysfs files.
  		 */
  		err = -EBUSY;
  		goto out_unlock;
  	}
  	ubi->volumes[vol_id] = NULL;
  	spin_unlock(&ubi->volumes_lock);
  
  	err = ubi_destroy_gluebi(vol);
  	if (err)
  		goto out_err;
  
  	err = ubi_change_vtbl_record(ubi, vol_id, NULL);
  	if (err)
  		goto out_err;
  
  	for (i = 0; i < vol->reserved_pebs; i++) {
  		err = ubi_eba_unmap_leb(ubi, vol, i);
  		if (err)
  			goto out_err;
  	}
  
  	kfree(vol->eba_tbl);
  	vol->eba_tbl = NULL;
  	cdev_del(&vol->cdev);
  	volume_sysfs_close(vol);
  
  	spin_lock(&ubi->volumes_lock);
  	ubi->rsvd_pebs -= reserved_pebs;
  	ubi->avail_pebs += reserved_pebs;
  	i = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs;
  	if (i > 0) {
  		i = ubi->avail_pebs >= i ? i : ubi->avail_pebs;
  		ubi->avail_pebs -= i;
  		ubi->rsvd_pebs += i;
  		ubi->beb_rsvd_pebs += i;
  		if (i > 0)
  			ubi_msg("reserve more %d PEBs", i);
  	}
  	ubi->vol_count -= 1;
  	spin_unlock(&ubi->volumes_lock);
  
  	paranoid_check_volumes(ubi);
  	return 0;
  
  out_err:
  	ubi_err("cannot remove volume %d, error %d", vol_id, err);
  	spin_lock(&ubi->volumes_lock);
  	ubi->volumes[vol_id] = vol;
  out_unlock:
  	spin_unlock(&ubi->volumes_lock);
  	return err;
  }
  
  /**
   * ubi_resize_volume - re-size volume.
   * @desc: volume descriptor
   * @reserved_pebs: new size in physical eraseblocks
   *
   * This function re-sizes the volume and returns zero in case of success, and a
   * negative error code in case of failure. The caller has to have the
   * @ubi->volumes_mutex locked.
   */
  int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs)
  {
  	int i, err, pebs, *new_mapping;
  	struct ubi_volume *vol = desc->vol;
  	struct ubi_device *ubi = vol->ubi;
  	struct ubi_vtbl_record vtbl_rec;
  	int vol_id = vol->vol_id;
  
  	if (ubi->ro_mode)
  		return -EROFS;
  
  	dbg_msg("re-size volume %d to from %d to %d PEBs",
  		vol_id, vol->reserved_pebs, reserved_pebs);
  
  	if (vol->vol_type == UBI_STATIC_VOLUME &&
  	    reserved_pebs < vol->used_ebs) {
  		dbg_err("too small size %d, %d LEBs contain data",
  			reserved_pebs, vol->used_ebs);
  		return -EINVAL;
  	}
  
  	/* If the size is the same, we have nothing to do */
  	if (reserved_pebs == vol->reserved_pebs)
  		return 0;
  
  	new_mapping = kmalloc(reserved_pebs * sizeof(int), GFP_KERNEL);
  	if (!new_mapping)
  		return -ENOMEM;
  
  	for (i = 0; i < reserved_pebs; i++)
  		new_mapping[i] = UBI_LEB_UNMAPPED;
  
  	spin_lock(&ubi->volumes_lock);
  	if (vol->ref_count > 1) {
  		spin_unlock(&ubi->volumes_lock);
  		err = -EBUSY;
  		goto out_free;
  	}
  	spin_unlock(&ubi->volumes_lock);
  
  	/* Reserve physical eraseblocks */
  	pebs = reserved_pebs - vol->reserved_pebs;
  	if (pebs > 0) {
  		spin_lock(&ubi->volumes_lock);
  		if (pebs > ubi->avail_pebs) {
  			dbg_err("not enough PEBs: requested %d, available %d",
  				pebs, ubi->avail_pebs);
  			spin_unlock(&ubi->volumes_lock);
  			err = -ENOSPC;
  			goto out_free;
  		}
  		ubi->avail_pebs -= pebs;
  		ubi->rsvd_pebs += pebs;
  		for (i = 0; i < vol->reserved_pebs; i++)
  			new_mapping[i] = vol->eba_tbl[i];
  		kfree(vol->eba_tbl);
  		vol->eba_tbl = new_mapping;
  		spin_unlock(&ubi->volumes_lock);
  	}
  
  	/* Change volume table record */
  	memcpy(&vtbl_rec, &ubi->vtbl[vol_id], sizeof(struct ubi_vtbl_record));
  	vtbl_rec.reserved_pebs = cpu_to_be32(reserved_pebs);
  	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
  	if (err)
  		goto out_acc;
  
  	if (pebs < 0) {
  		for (i = 0; i < -pebs; i++) {
  			err = ubi_eba_unmap_leb(ubi, vol, reserved_pebs + i);
  			if (err)
  				goto out_acc;
  		}
  		spin_lock(&ubi->volumes_lock);
  		ubi->rsvd_pebs += pebs;
  		ubi->avail_pebs -= pebs;
  		pebs = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs;
  		if (pebs > 0) {
  			pebs = ubi->avail_pebs >= pebs ? pebs : ubi->avail_pebs;
  			ubi->avail_pebs -= pebs;
  			ubi->rsvd_pebs += pebs;
  			ubi->beb_rsvd_pebs += pebs;
  			if (pebs > 0)
  				ubi_msg("reserve more %d PEBs", pebs);
  		}
  		for (i = 0; i < reserved_pebs; i++)
  			new_mapping[i] = vol->eba_tbl[i];
  		kfree(vol->eba_tbl);
  		vol->eba_tbl = new_mapping;
  		spin_unlock(&ubi->volumes_lock);
  	}
  
  	vol->reserved_pebs = reserved_pebs;
  	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
  		vol->used_ebs = reserved_pebs;
  		vol->last_eb_bytes = vol->usable_leb_size;
  		vol->used_bytes =
  			(long long)vol->used_ebs * vol->usable_leb_size;
  	}
  
  	paranoid_check_volumes(ubi);
  	return 0;
  
  out_acc:
  	if (pebs > 0) {
  		spin_lock(&ubi->volumes_lock);
  		ubi->rsvd_pebs -= pebs;
  		ubi->avail_pebs += pebs;
  		spin_unlock(&ubi->volumes_lock);
  	}
  out_free:
  	kfree(new_mapping);
  	return err;
  }
  
  /**
   * ubi_add_volume - add volume.
   * @ubi: UBI device description object
   * @vol: volume description object
   *
   * This function adds an existing volume and initializes all its data
   * structures. Returns zero in case of success and a negative error code in
   * case of failure.
   */
  int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol)
  {
  	int err, vol_id = vol->vol_id;
  	dev_t dev;
  
  	dbg_msg("add volume %d", vol_id);
  	ubi_dbg_dump_vol_info(vol);
  
  	/* Register character device for the volume */
  	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
  	vol->cdev.owner = THIS_MODULE;
  	dev = MKDEV(MAJOR(ubi->cdev.dev), vol->vol_id + 1);
  	err = cdev_add(&vol->cdev, dev, 1);
  	if (err) {
  		ubi_err("cannot add character device for volume %d, error %d",
  			vol_id, err);
  		return err;
  	}
  
  	err = ubi_create_gluebi(ubi, vol);
  	if (err)
  		goto out_cdev;
  
  	vol->dev.release = vol_release;
  	vol->dev.parent = &ubi->dev;
  	vol->dev.devt = dev;
  	vol->dev.class = ubi_class;
  	sprintf(&vol->dev.bus_id[0], "%s_%d", ubi->ubi_name, vol->vol_id);
  	err = device_register(&vol->dev);
  	if (err)
  		goto out_gluebi;
  
  	err = volume_sysfs_init(ubi, vol);
  	if (err) {
  		cdev_del(&vol->cdev);
  		err = ubi_destroy_gluebi(vol);
  		volume_sysfs_close(vol);
  		return err;
  	}
  
  	paranoid_check_volumes(ubi);
  	return 0;
  
  out_gluebi:
  	err = ubi_destroy_gluebi(vol);
  out_cdev:
  	cdev_del(&vol->cdev);
  	return err;
  }
  
  /**
   * ubi_free_volume - free volume.
   * @ubi: UBI device description object
   * @vol: volume description object
   *
   * This function frees all resources for volume @vol but does not remove it.
   * Used only when the UBI device is detached.
   */
  void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol)
  {
  	int err;
  
  	dbg_msg("free volume %d", vol->vol_id);
  
  	ubi->volumes[vol->vol_id] = NULL;
  	err = ubi_destroy_gluebi(vol);
  	cdev_del(&vol->cdev);
  	volume_sysfs_close(vol);
  }
  
  #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
  
  /**
   * paranoid_check_volume - check volume information.
   * @ubi: UBI device description object
   * @vol_id: volume ID
   */
  static void paranoid_check_volume(struct ubi_device *ubi, int vol_id)
  {
  	int idx = vol_id2idx(ubi, vol_id);
  	int reserved_pebs, alignment, data_pad, vol_type, name_len, upd_marker;
  	const struct ubi_volume *vol;
  	long long n;
  	const char *name;
  
  	spin_lock(&ubi->volumes_lock);
  	reserved_pebs = be32_to_cpu(ubi->vtbl[vol_id].reserved_pebs);
  	vol = ubi->volumes[idx];
  
  	if (!vol) {
  		if (reserved_pebs) {
  			ubi_err("no volume info, but volume exists");
  			goto fail;
  		}
  		spin_unlock(&ubi->volumes_lock);
  		return;
  	}
  
  	if (vol->exclusive) {
  		/*
  		 * The volume may be being created at the moment, do not check
  		 * it (e.g., it may be in the middle of ubi_create_volume().
  		 */
  		spin_unlock(&ubi->volumes_lock);
  		return;
  	}
  
  	if (vol->reserved_pebs < 0 || vol->alignment < 0 || vol->data_pad < 0 ||
  	    vol->name_len < 0) {
  		ubi_err("negative values");
  		goto fail;
  	}
  	if (vol->alignment > ubi->leb_size || vol->alignment == 0) {
  		ubi_err("bad alignment");
  		goto fail;
  	}
  
  	n = vol->alignment & (ubi->min_io_size - 1);
  	if (vol->alignment != 1 && n) {
  		ubi_err("alignment is not multiple of min I/O unit");
  		goto fail;
  	}
  
  	n = ubi->leb_size % vol->alignment;
  	if (vol->data_pad != n) {
  		ubi_err("bad data_pad, has to be %lld", n);
  		goto fail;
  	}
  
  	if (vol->vol_type != UBI_DYNAMIC_VOLUME &&
  	    vol->vol_type != UBI_STATIC_VOLUME) {
  		ubi_err("bad vol_type");
  		goto fail;
  	}
  
  	if (vol->upd_marker && vol->corrupted) {
  		dbg_err("update marker and corrupted simultaneously");
  		goto fail;
  	}
  
  	if (vol->reserved_pebs > ubi->good_peb_count) {
  		ubi_err("too large reserved_pebs");
  		goto fail;
  	}
  
  	n = ubi->leb_size - vol->data_pad;
  	if (vol->usable_leb_size != ubi->leb_size - vol->data_pad) {
  		ubi_err("bad usable_leb_size, has to be %lld", n);
  		goto fail;
  	}
  
  	if (vol->name_len > UBI_VOL_NAME_MAX) {
  		ubi_err("too long volume name, max is %d", UBI_VOL_NAME_MAX);
  		goto fail;
  	}
  
  	if (!vol->name) {
  		ubi_err("NULL volume name");
  		goto fail;
  	}
  
  	n = strnlen(vol->name, vol->name_len + 1);
  	if (n != vol->name_len) {
  		ubi_err("bad name_len %lld", n);
  		goto fail;
  	}
  
  	n = (long long)vol->used_ebs * vol->usable_leb_size;
  	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
  		if (vol->corrupted) {
  			ubi_err("corrupted dynamic volume");
  			goto fail;
  		}
  		if (vol->used_ebs != vol->reserved_pebs) {
  			ubi_err("bad used_ebs");
  			goto fail;
  		}
  		if (vol->last_eb_bytes != vol->usable_leb_size) {
  			ubi_err("bad last_eb_bytes");
  			goto fail;
  		}
  		if (vol->used_bytes != n) {
  			ubi_err("bad used_bytes");
  			goto fail;
  		}
  	} else {
  		if (vol->used_ebs < 0 || vol->used_ebs > vol->reserved_pebs) {
  			ubi_err("bad used_ebs");
  			goto fail;
  		}
  		if (vol->last_eb_bytes < 0 ||
  		    vol->last_eb_bytes > vol->usable_leb_size) {
  			ubi_err("bad last_eb_bytes");
  			goto fail;
  		}
  		if (vol->used_bytes < 0 || vol->used_bytes > n ||
  		    vol->used_bytes < n - vol->usable_leb_size) {
  			ubi_err("bad used_bytes");
  			goto fail;
  		}
  	}
  
  	alignment  = be32_to_cpu(ubi->vtbl[vol_id].alignment);
  	data_pad   = be32_to_cpu(ubi->vtbl[vol_id].data_pad);
  	name_len   = be16_to_cpu(ubi->vtbl[vol_id].name_len);
  	upd_marker = ubi->vtbl[vol_id].upd_marker;
  	name       = &ubi->vtbl[vol_id].name[0];
  	if (ubi->vtbl[vol_id].vol_type == UBI_VID_DYNAMIC)
  		vol_type = UBI_DYNAMIC_VOLUME;
  	else
  		vol_type = UBI_STATIC_VOLUME;
  
  	if (alignment != vol->alignment || data_pad != vol->data_pad ||
  	    upd_marker != vol->upd_marker || vol_type != vol->vol_type ||
  	    name_len!= vol->name_len || strncmp(name, vol->name, name_len)) {
  		ubi_err("volume info is different");
  		goto fail;
  	}
  
  	spin_unlock(&ubi->volumes_lock);
  	return;
  
  fail:
  	ubi_err("paranoid check failed for volume %d", vol_id);
  	ubi_dbg_dump_vol_info(vol);
  	ubi_dbg_dump_vtbl_record(&ubi->vtbl[vol_id], vol_id);
  	spin_unlock(&ubi->volumes_lock);
  	BUG();
  }
  
  /**
   * paranoid_check_volumes - check information about all volumes.
   * @ubi: UBI device description object
   */
  static void paranoid_check_volumes(struct ubi_device *ubi)
  {
  	int i;
  
  	for (i = 0; i < ubi->vtbl_slots; i++)
  		paranoid_check_volume(ubi, i);
  }
  #endif
  