text: // SPDX-License-Identifier: GPL-2.0-or-later
  /*
   * vvvvvvvvvvvvvvvvvvvvvvv Original vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
   *  Copyright (C) 1992  Eric Youngdale
   *  Simulate a host adapter with 2 disks attached.  Do a lot of checking
   *  to make sure that we are not getting blocks mixed up, and PANIC if
   *  anything out of the ordinary is seen.
   * ^^^^^^^^^^^^^^^^^^^^^^^ Original ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   *
   * Copyright (C) 2001 - 2018 Douglas Gilbert
   *
   *  For documentation see http://sg.danny.cz/sg/sdebug26.html
   */
  
  
  #define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
  
  #include <linux/module.h>
  
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/jiffies.h>
  #include <linux/slab.h>
  #include <linux/types.h>
  #include <linux/string.h>
  #include <linux/genhd.h>
  #include <linux/fs.h>
  #include <linux/init.h>
  #include <linux/proc_fs.h>
  #include <linux/vmalloc.h>
  #include <linux/moduleparam.h>
  #include <linux/scatterlist.h>
  #include <linux/blkdev.h>
  #include <linux/crc-t10dif.h>
  #include <linux/spinlock.h>
  #include <linux/interrupt.h>
  #include <linux/atomic.h>
  #include <linux/hrtimer.h>
  #include <linux/uuid.h>
  #include <linux/t10-pi.h>
  
  #include <net/checksum.h>
  
  #include <asm/unaligned.h>
  
  #include <scsi/scsi.h>
  #include <scsi/scsi_cmnd.h>
  #include <scsi/scsi_device.h>
  #include <scsi/scsi_host.h>
  #include <scsi/scsicam.h>
  #include <scsi/scsi_eh.h>
  #include <scsi/scsi_tcq.h>
  #include <scsi/scsi_dbg.h>
  
  #include "sd.h"
  #include "scsi_logging.h"
  
  /* make sure inq_product_rev string corresponds to this version */
  #define SDEBUG_VERSION "0188"	/* format to fit INQUIRY revision field */
  static const char *sdebug_version_date = "20190125";
  
  #define MY_NAME "scsi_debug"
  
  /* Additional Sense Code (ASC) */
  #define NO_ADDITIONAL_SENSE 0x0
  #define LOGICAL_UNIT_NOT_READY 0x4
  #define LOGICAL_UNIT_COMMUNICATION_FAILURE 0x8
  #define UNRECOVERED_READ_ERR 0x11
  #define PARAMETER_LIST_LENGTH_ERR 0x1a
  #define INVALID_OPCODE 0x20
  #define LBA_OUT_OF_RANGE 0x21
  #define INVALID_FIELD_IN_CDB 0x24
  #define INVALID_FIELD_IN_PARAM_LIST 0x26
  #define WRITE_PROTECTED 0x27
  #define UA_RESET_ASC 0x29
  #define UA_CHANGED_ASC 0x2a
  #define TARGET_CHANGED_ASC 0x3f
  #define LUNS_CHANGED_ASCQ 0x0e
  #define INSUFF_RES_ASC 0x55
  #define INSUFF_RES_ASCQ 0x3
  #define POWER_ON_RESET_ASCQ 0x0
  #define BUS_RESET_ASCQ 0x2	/* scsi bus reset occurred */
  #define MODE_CHANGED_ASCQ 0x1	/* mode parameters changed */
  #define CAPACITY_CHANGED_ASCQ 0x9
  #define SAVING_PARAMS_UNSUP 0x39
  #define TRANSPORT_PROBLEM 0x4b
  #define THRESHOLD_EXCEEDED 0x5d
  #define LOW_POWER_COND_ON 0x5e
  #define MISCOMPARE_VERIFY_ASC 0x1d
  #define MICROCODE_CHANGED_ASCQ 0x1	/* with TARGET_CHANGED_ASC */
  #define MICROCODE_CHANGED_WO_RESET_ASCQ 0x16
  #define WRITE_ERROR_ASC 0xc
  
  /* Additional Sense Code Qualifier (ASCQ) */
  #define ACK_NAK_TO 0x3
  
  /* Default values for driver parameters */
  #define DEF_NUM_HOST   1
  #define DEF_NUM_TGTS   1
  #define DEF_MAX_LUNS   1
  /* With these defaults, this driver will make 1 host with 1 target
   * (id 0) containing 1 logical unit (lun 0). That is 1 device.
   */
  #define DEF_ATO 1
  #define DEF_CDB_LEN 10
  #define DEF_JDELAY   1		/* if > 0 unit is a jiffy */
  #define DEF_DEV_SIZE_MB   8
  #define DEF_DIF 0
  #define DEF_DIX 0
  #define DEF_D_SENSE   0
  #define DEF_EVERY_NTH   0
  #define DEF_FAKE_RW	0
  #define DEF_GUARD 0
  #define DEF_HOST_LOCK 0
  #define DEF_LBPU 0
  #define DEF_LBPWS 0
  #define DEF_LBPWS10 0
  #define DEF_LBPRZ 1
  #define DEF_LOWEST_ALIGNED 0
  #define DEF_NDELAY   0		/* if > 0 unit is a nanosecond */
  #define DEF_NO_LUN_0   0
  #define DEF_NUM_PARTS   0
  #define DEF_OPTS   0
  #define DEF_OPT_BLKS 1024
  #define DEF_PHYSBLK_EXP 0
  #define DEF_OPT_XFERLEN_EXP 0
  #define DEF_PTYPE   TYPE_DISK
  #define DEF_REMOVABLE false
  #define DEF_SCSI_LEVEL   7    /* INQUIRY, byte2 [6->SPC-4; 7->SPC-5] */
  #define DEF_SECTOR_SIZE 512
  #define DEF_UNMAP_ALIGNMENT 0
  #define DEF_UNMAP_GRANULARITY 1
  #define DEF_UNMAP_MAX_BLOCKS 0xFFFFFFFF
  #define DEF_UNMAP_MAX_DESC 256
  #define DEF_VIRTUAL_GB   0
  #define DEF_VPD_USE_HOSTNO 1
  #define DEF_WRITESAME_LENGTH 0xFFFF
  #define DEF_STRICT 0
  #define DEF_STATISTICS false
  #define DEF_SUBMIT_QUEUES 1
  #define DEF_UUID_CTL 0
  #define JDELAY_OVERRIDDEN -9999
  
  #define SDEBUG_LUN_0_VAL 0
  
  /* bit mask values for sdebug_opts */
  #define SDEBUG_OPT_NOISE		1
  #define SDEBUG_OPT_MEDIUM_ERR		2
  #define SDEBUG_OPT_TIMEOUT		4
  #define SDEBUG_OPT_RECOVERED_ERR	8
  #define SDEBUG_OPT_TRANSPORT_ERR	16
  #define SDEBUG_OPT_DIF_ERR		32
  #define SDEBUG_OPT_DIX_ERR		64
  #define SDEBUG_OPT_MAC_TIMEOUT		128
  #define SDEBUG_OPT_SHORT_TRANSFER	0x100
  #define SDEBUG_OPT_Q_NOISE		0x200
  #define SDEBUG_OPT_ALL_TSF		0x400
  #define SDEBUG_OPT_RARE_TSF		0x800
  #define SDEBUG_OPT_N_WCE		0x1000
  #define SDEBUG_OPT_RESET_NOISE		0x2000
  #define SDEBUG_OPT_NO_CDB_NOISE		0x4000
  #define SDEBUG_OPT_HOST_BUSY		0x8000
  #define SDEBUG_OPT_CMD_ABORT		0x10000
  #define SDEBUG_OPT_ALL_NOISE (SDEBUG_OPT_NOISE | SDEBUG_OPT_Q_NOISE | \
  			      SDEBUG_OPT_RESET_NOISE)
  #define SDEBUG_OPT_ALL_INJECTING (SDEBUG_OPT_RECOVERED_ERR | \
  				  SDEBUG_OPT_TRANSPORT_ERR | \
  				  SDEBUG_OPT_DIF_ERR | SDEBUG_OPT_DIX_ERR | \
  				  SDEBUG_OPT_SHORT_TRANSFER | \
  				  SDEBUG_OPT_HOST_BUSY | \
  				  SDEBUG_OPT_CMD_ABORT)
  /* When "every_nth" > 0 then modulo "every_nth" commands:
   *   - a missing response is simulated if SDEBUG_OPT_TIMEOUT is set
   *   - a RECOVERED_ERROR is simulated on successful read and write
   *     commands if SDEBUG_OPT_RECOVERED_ERR is set.
   *   - a TRANSPORT_ERROR is simulated on successful read and write
   *     commands if SDEBUG_OPT_TRANSPORT_ERR is set.
   *   - similarly for DIF_ERR, DIX_ERR, SHORT_TRANSFER, HOST_BUSY and
   *     CMD_ABORT
   *
   * When "every_nth" < 0 then after "- every_nth" commands the selected
   * error will be injected. The error will be injected on every subsequent
   * command until some other action occurs; for example, the user writing
   * a new value (other than -1 or 1) to every_nth:
   *      echo 0 > /sys/bus/pseudo/drivers/scsi_debug/every_nth
   */
  
  /* As indicated in SAM-5 and SPC-4 Unit Attentions (UAs) are returned in
   * priority order. In the subset implemented here lower numbers have higher
   * priority. The UA numbers should be a sequence starting from 0 with
   * SDEBUG_NUM_UAS being 1 higher than the highest numbered UA. */
  #define SDEBUG_UA_POR 0		/* Power on, reset, or bus device reset */
  #define SDEBUG_UA_BUS_RESET 1
  #define SDEBUG_UA_MODE_CHANGED 2
  #define SDEBUG_UA_CAPACITY_CHANGED 3
  #define SDEBUG_UA_LUNS_CHANGED 4
  #define SDEBUG_UA_MICROCODE_CHANGED 5	/* simulate firmware change */
  #define SDEBUG_UA_MICROCODE_CHANGED_WO_RESET 6
  #define SDEBUG_NUM_UAS 7
  
  /* when 1==SDEBUG_OPT_MEDIUM_ERR, a medium error is simulated at this
   * sector on read commands: */
  #define OPT_MEDIUM_ERR_ADDR   0x1234 /* that's sector 4660 in decimal */
  #define OPT_MEDIUM_ERR_NUM    10     /* number of consecutive medium errs */
  
  /* If REPORT LUNS has luns >= 256 it can choose "flat space" (value 1)
   * or "peripheral device" addressing (value 0) */
  #define SAM2_LUN_ADDRESS_METHOD 0
  
  /* SDEBUG_CANQUEUE is the maximum number of commands that can be queued
   * (for response) per submit queue at one time. Can be reduced by max_queue
   * option. Command responses are not queued when jdelay=0 and ndelay=0. The
   * per-device DEF_CMD_PER_LUN can be changed via sysfs:
   * /sys/class/scsi_device/<h:c:t:l>/device/queue_depth
   * but cannot exceed SDEBUG_CANQUEUE .
   */
  #define SDEBUG_CANQUEUE_WORDS  3	/* a WORD is bits in a long */
  #define SDEBUG_CANQUEUE  (SDEBUG_CANQUEUE_WORDS * BITS_PER_LONG)
  #define DEF_CMD_PER_LUN  255
  
  #define F_D_IN			1
  #define F_D_OUT			2
  #define F_D_OUT_MAYBE		4	/* WRITE SAME, NDOB bit */
  #define F_D_UNKN		8
  #define F_RL_WLUN_OK		0x10
  #define F_SKIP_UA		0x20
  #define F_DELAY_OVERR		0x40
  #define F_SA_LOW		0x80	/* cdb byte 1, bits 4 to 0 */
  #define F_SA_HIGH		0x100	/* as used by variable length cdbs */
  #define F_INV_OP		0x200
  #define F_FAKE_RW		0x400
  #define F_M_ACCESS		0x800	/* media access */
  #define F_SSU_DELAY		0x1000
  #define F_SYNC_DELAY		0x2000
  
  #define FF_RESPOND (F_RL_WLUN_OK | F_SKIP_UA | F_DELAY_OVERR)
  #define FF_MEDIA_IO (F_M_ACCESS | F_FAKE_RW)
  #define FF_SA (F_SA_HIGH | F_SA_LOW)
  #define F_LONG_DELAY		(F_SSU_DELAY | F_SYNC_DELAY)
  
  #define SDEBUG_MAX_PARTS 4
  
  #define SDEBUG_MAX_CMD_LEN 32
  
  
  struct sdebug_dev_info {
  	struct list_head dev_list;
  	unsigned int channel;
  	unsigned int target;
  	u64 lun;
  	uuid_t lu_name;
  	struct sdebug_host_info *sdbg_host;
  	unsigned long uas_bm[1];
  	atomic_t num_in_q;
  	atomic_t stopped;
  	bool used;
  };
  
  struct sdebug_host_info {
  	struct list_head host_list;
  	struct Scsi_Host *shost;
  	struct device dev;
  	struct list_head dev_info_list;
  };
  
  #define to_sdebug_host(d)	\
  	container_of(d, struct sdebug_host_info, dev)
  
  enum sdeb_defer_type {SDEB_DEFER_NONE = 0, SDEB_DEFER_HRT = 1,
  		      SDEB_DEFER_WQ = 2};
  
  struct sdebug_defer {
  	struct hrtimer hrt;
  	struct execute_work ew;
  	int sqa_idx;	/* index of sdebug_queue array */
  	int qc_idx;	/* index of sdebug_queued_cmd array within sqa_idx */
  	int issuing_cpu;
  	bool init_hrt;
  	bool init_wq;
  	bool aborted;	/* true when blk_abort_request() already called */
  	enum sdeb_defer_type defer_t;
  };
  
  struct sdebug_queued_cmd {
  	/* corresponding bit set in in_use_bm[] in owning struct sdebug_queue
  	 * instance indicates this slot is in use.
  	 */
  	struct sdebug_defer *sd_dp;
  	struct scsi_cmnd *a_cmnd;
  	unsigned int inj_recovered:1;
  	unsigned int inj_transport:1;
  	unsigned int inj_dif:1;
  	unsigned int inj_dix:1;
  	unsigned int inj_short:1;
  	unsigned int inj_host_busy:1;
  	unsigned int inj_cmd_abort:1;
  };
  
  struct sdebug_queue {
  	struct sdebug_queued_cmd qc_arr[SDEBUG_CANQUEUE];
  	unsigned long in_use_bm[SDEBUG_CANQUEUE_WORDS];
  	spinlock_t qc_lock;
  	atomic_t blocked;	/* to temporarily stop more being queued */
  };
  
  static atomic_t sdebug_cmnd_count;   /* number of incoming commands */
  static atomic_t sdebug_completions;  /* count of deferred completions */
  static atomic_t sdebug_miss_cpus;    /* submission + completion cpus differ */
  static atomic_t sdebug_a_tsf;	     /* 'almost task set full' counter */
  
  struct opcode_info_t {
  	u8 num_attached;	/* 0 if this is it (i.e. a leaf); use 0xff */
  				/* for terminating element */
  	u8 opcode;		/* if num_attached > 0, preferred */
  	u16 sa;			/* service action */
  	u32 flags;		/* OR-ed set of SDEB_F_* */
  	int (*pfp)(struct scsi_cmnd *, struct sdebug_dev_info *);
  	const struct opcode_info_t *arrp;  /* num_attached elements or NULL */
  	u8 len_mask[16];	/* len_mask[0]-->cdb_len, then mask for cdb */
  				/* 1 to min(cdb_len, 15); ignore cdb[15...] */
  };
  
  /* SCSI opcodes (first byte of cdb) of interest mapped onto these indexes */
  enum sdeb_opcode_index {
  	SDEB_I_INVALID_OPCODE =	0,
  	SDEB_I_INQUIRY = 1,
  	SDEB_I_REPORT_LUNS = 2,
  	SDEB_I_REQUEST_SENSE = 3,
  	SDEB_I_TEST_UNIT_READY = 4,
  	SDEB_I_MODE_SENSE = 5,		/* 6, 10 */
  	SDEB_I_MODE_SELECT = 6,		/* 6, 10 */
  	SDEB_I_LOG_SENSE = 7,
  	SDEB_I_READ_CAPACITY = 8,	/* 10; 16 is in SA_IN(16) */
  	SDEB_I_READ = 9,		/* 6, 10, 12, 16 */
  	SDEB_I_WRITE = 10,		/* 6, 10, 12, 16 */
  	SDEB_I_START_STOP = 11,
  	SDEB_I_SERV_ACT_IN_16 = 12,	/* add ...SERV_ACT_IN_12 if needed */
  	SDEB_I_SERV_ACT_OUT_16 = 13,	/* add ...SERV_ACT_OUT_12 if needed */
  	SDEB_I_MAINT_IN = 14,
  	SDEB_I_MAINT_OUT = 15,
  	SDEB_I_VERIFY = 16,		/* 10 only */
  	SDEB_I_VARIABLE_LEN = 17,	/* READ(32), WRITE(32), WR_SCAT(32) */
  	SDEB_I_RESERVE = 18,		/* 6, 10 */
  	SDEB_I_RELEASE = 19,		/* 6, 10 */
  	SDEB_I_ALLOW_REMOVAL = 20,	/* PREVENT ALLOW MEDIUM REMOVAL */
  	SDEB_I_REZERO_UNIT = 21,	/* REWIND in SSC */
  	SDEB_I_ATA_PT = 22,		/* 12, 16 */
  	SDEB_I_SEND_DIAG = 23,
  	SDEB_I_UNMAP = 24,
  	SDEB_I_WRITE_BUFFER = 25,
  	SDEB_I_WRITE_SAME = 26,		/* 10, 16 */
  	SDEB_I_SYNC_CACHE = 27,		/* 10, 16 */
  	SDEB_I_COMP_WRITE = 28,
  	SDEB_I_LAST_ELEMENT = 29,	/* keep this last (previous + 1) */
  };
  
  
  static const unsigned char opcode_ind_arr[256] = {
  /* 0x0; 0x0->0x1f: 6 byte cdbs */
  	SDEB_I_TEST_UNIT_READY, SDEB_I_REZERO_UNIT, 0, SDEB_I_REQUEST_SENSE,
  	    0, 0, 0, 0,
  	SDEB_I_READ, 0, SDEB_I_WRITE, 0, 0, 0, 0, 0,
  	0, 0, SDEB_I_INQUIRY, 0, 0, SDEB_I_MODE_SELECT, SDEB_I_RESERVE,
  	    SDEB_I_RELEASE,
  	0, 0, SDEB_I_MODE_SENSE, SDEB_I_START_STOP, 0, SDEB_I_SEND_DIAG,
  	    SDEB_I_ALLOW_REMOVAL, 0,
  /* 0x20; 0x20->0x3f: 10 byte cdbs */
  	0, 0, 0, 0, 0, SDEB_I_READ_CAPACITY, 0, 0,
  	SDEB_I_READ, 0, SDEB_I_WRITE, 0, 0, 0, 0, SDEB_I_VERIFY,
  	0, 0, 0, 0, 0, SDEB_I_SYNC_CACHE, 0, 0,
  	0, 0, 0, SDEB_I_WRITE_BUFFER, 0, 0, 0, 0,
  /* 0x40; 0x40->0x5f: 10 byte cdbs */
  	0, SDEB_I_WRITE_SAME, SDEB_I_UNMAP, 0, 0, 0, 0, 0,
  	0, 0, 0, 0, 0, SDEB_I_LOG_SENSE, 0, 0,
  	0, 0, 0, 0, 0, SDEB_I_MODE_SELECT, SDEB_I_RESERVE,
  	    SDEB_I_RELEASE,
  	0, 0, SDEB_I_MODE_SENSE, 0, 0, 0, 0, 0,
  /* 0x60; 0x60->0x7d are reserved, 0x7e is "extended cdb" */
  	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  	0, SDEB_I_VARIABLE_LEN,
  /* 0x80; 0x80->0x9f: 16 byte cdbs */
  	0, 0, 0, 0, 0, SDEB_I_ATA_PT, 0, 0,
  	SDEB_I_READ, SDEB_I_COMP_WRITE, SDEB_I_WRITE, 0, 0, 0, 0, 0,
  	0, SDEB_I_SYNC_CACHE, 0, SDEB_I_WRITE_SAME, 0, 0, 0, 0,
  	0, 0, 0, 0, 0, 0, SDEB_I_SERV_ACT_IN_16, SDEB_I_SERV_ACT_OUT_16,
  /* 0xa0; 0xa0->0xbf: 12 byte cdbs */
  	SDEB_I_REPORT_LUNS, SDEB_I_ATA_PT, 0, SDEB_I_MAINT_IN,
  	     SDEB_I_MAINT_OUT, 0, 0, 0,
  	SDEB_I_READ, 0 /* SDEB_I_SERV_ACT_OUT_12 */, SDEB_I_WRITE,
  	     0 /* SDEB_I_SERV_ACT_IN_12 */, 0, 0, 0, 0,
  	0, 0, 0, 0, 0, 0, 0, 0,
  	0, 0, 0, 0, 0, 0, 0, 0,
  /* 0xc0; 0xc0->0xff: vendor specific */
  	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  };
  
  /*
   * The following "response" functions return the SCSI mid-level's 4 byte
   * tuple-in-an-int. To handle commands with an IMMED bit, for a faster
   * command completion, they can mask their return value with
   * SDEG_RES_IMMED_MASK .
   */
  #define SDEG_RES_IMMED_MASK 0x40000000
  
  static int resp_inquiry(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_report_luns(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_requests(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_mode_sense(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_mode_select(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_log_sense(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_readcap(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_read_dt0(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_write_dt0(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_write_scat(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_start_stop(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_readcap16(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_get_lba_status(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_report_tgtpgs(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_unmap(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_rsup_opcodes(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_rsup_tmfs(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_write_same_10(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_write_same_16(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_comp_write(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_write_buffer(struct scsi_cmnd *, struct sdebug_dev_info *);
  static int resp_sync_cache(struct scsi_cmnd *, struct sdebug_dev_info *);
  
  /*
   * The following are overflow arrays for cdbs that "hit" the same index in
   * the opcode_info_arr array. The most time sensitive (or commonly used) cdb
   * should be placed in opcode_info_arr[], the others should be placed here.
   */
  static const struct opcode_info_t msense_iarr[] = {
  	{0, 0x1a, 0, F_D_IN, NULL, NULL,
  	    {6,  0xe8, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
  };
  
  static const struct opcode_info_t mselect_iarr[] = {
  	{0, 0x15, 0, F_D_OUT, NULL, NULL,
  	    {6,  0xf1, 0, 0, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
  };
  
  static const struct opcode_info_t read_iarr[] = {
  	{0, 0x28, 0, F_D_IN | FF_MEDIA_IO, resp_read_dt0, NULL,/* READ(10) */
  	    {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff, 0xff, 0xc7, 0, 0,
  	     0, 0, 0, 0} },
  	{0, 0x8, 0, F_D_IN | FF_MEDIA_IO, resp_read_dt0, NULL, /* READ(6) */
  	    {6,  0xff, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
  	{0, 0xa8, 0, F_D_IN | FF_MEDIA_IO, resp_read_dt0, NULL,/* READ(12) */
  	    {12,  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xbf,
  	     0xc7, 0, 0, 0, 0} },
  };
  
  static const struct opcode_info_t write_iarr[] = {
  	{0, 0x2a, 0, F_D_OUT | FF_MEDIA_IO, resp_write_dt0,  /* WRITE(10) */
  	    NULL, {10,  0xfb, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff, 0xff, 0xc7,
  		   0, 0, 0, 0, 0, 0} },
  	{0, 0xa, 0, F_D_OUT | FF_MEDIA_IO, resp_write_dt0,   /* WRITE(6) */
  	    NULL, {6,  0xff, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0,
  		   0, 0, 0} },
  	{0, 0xaa, 0, F_D_OUT | FF_MEDIA_IO, resp_write_dt0,  /* WRITE(12) */
  	    NULL, {12,  0xfb, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  		   0xbf, 0xc7, 0, 0, 0, 0} },
  };
  
  static const struct opcode_info_t sa_in_16_iarr[] = {
  	{0, 0x9e, 0x12, F_SA_LOW | F_D_IN, resp_get_lba_status, NULL,
  	    {16,  0x12, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  	     0xff, 0xff, 0xff, 0, 0xc7} },	/* GET LBA STATUS(16) */
  };
  
  static const struct opcode_info_t vl_iarr[] = {	/* VARIABLE LENGTH */
  	{0, 0x7f, 0xb, F_SA_HIGH | F_D_OUT | FF_MEDIA_IO, resp_write_dt0,
  	    NULL, {32,  0xc7, 0, 0, 0, 0, 0x3f, 0x18, 0x0, 0xb, 0xfa,
  		   0, 0xff, 0xff, 0xff, 0xff} },	/* WRITE(32) */
  	{0, 0x7f, 0x11, F_SA_HIGH | F_D_OUT | FF_MEDIA_IO, resp_write_scat,
  	    NULL, {32,  0xc7, 0, 0, 0, 0, 0x3f, 0x18, 0x0, 0x11, 0xf8,
  		   0, 0xff, 0xff, 0x0, 0x0} },	/* WRITE SCATTERED(32) */
  };
  
  static const struct opcode_info_t maint_in_iarr[] = {	/* MAINT IN */
  	{0, 0xa3, 0xc, F_SA_LOW | F_D_IN, resp_rsup_opcodes, NULL,
  	    {12,  0xc, 0x87, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0,
  	     0xc7, 0, 0, 0, 0} }, /* REPORT SUPPORTED OPERATION CODES */
  	{0, 0xa3, 0xd, F_SA_LOW | F_D_IN, resp_rsup_tmfs, NULL,
  	    {12,  0xd, 0x80, 0, 0, 0, 0xff, 0xff, 0xff, 0xff, 0, 0xc7, 0, 0,
  	     0, 0} },	/* REPORTED SUPPORTED TASK MANAGEMENT FUNCTIONS */
  };
  
  static const struct opcode_info_t write_same_iarr[] = {
  	{0, 0x93, 0, F_D_OUT_MAYBE | FF_MEDIA_IO, resp_write_same_16, NULL,
  	    {16,  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  	     0xff, 0xff, 0xff, 0x3f, 0xc7} },		/* WRITE SAME(16) */
  };
  
  static const struct opcode_info_t reserve_iarr[] = {
  	{0, 0x16, 0, F_D_OUT, NULL, NULL,		/* RESERVE(6) */
  	    {6,  0x1f, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
  };
  
  static const struct opcode_info_t release_iarr[] = {
  	{0, 0x17, 0, F_D_OUT, NULL, NULL,		/* RELEASE(6) */
  	    {6,  0x1f, 0xff, 0, 0, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
  };
  
  static const struct opcode_info_t sync_cache_iarr[] = {
  	{0, 0x91, 0, F_SYNC_DELAY | F_M_ACCESS, resp_sync_cache, NULL,
  	    {16,  0x6, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  	     0xff, 0xff, 0xff, 0xff, 0x3f, 0xc7} },	/* SYNC_CACHE (16) */
  };
  
  
  /* This array is accessed via SDEB_I_* values. Make sure all are mapped,
   * plus the terminating elements for logic that scans this table such as
   * REPORT SUPPORTED OPERATION CODES. */
  static const struct opcode_info_t opcode_info_arr[SDEB_I_LAST_ELEMENT + 1] = {
  /* 0 */
  	{0, 0, 0, F_INV_OP | FF_RESPOND, NULL, NULL,	/* unknown opcodes */
  	    {0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
  	{0, 0x12, 0, FF_RESPOND | F_D_IN, resp_inquiry, NULL, /* INQUIRY */
  	    {6,  0xe3, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
  	{0, 0xa0, 0, FF_RESPOND | F_D_IN, resp_report_luns, NULL,
  	    {12,  0xe3, 0xff, 0, 0, 0, 0xff, 0xff, 0xff, 0xff, 0, 0xc7, 0, 0,
  	     0, 0} },					/* REPORT LUNS */
  	{0, 0x3, 0, FF_RESPOND | F_D_IN, resp_requests, NULL,
  	    {6,  0xe1, 0, 0, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
  	{0, 0x0, 0, F_M_ACCESS | F_RL_WLUN_OK, NULL, NULL,/* TEST UNIT READY */
  	    {6,  0, 0, 0, 0, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
  /* 5 */
  	{ARRAY_SIZE(msense_iarr), 0x5a, 0, F_D_IN,	/* MODE SENSE(10) */
  	    resp_mode_sense, msense_iarr, {10,  0xf8, 0xff, 0xff, 0, 0, 0,
  		0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0} },
  	{ARRAY_SIZE(mselect_iarr), 0x55, 0, F_D_OUT,	/* MODE SELECT(10) */
  	    resp_mode_select, mselect_iarr, {10,  0xf1, 0, 0, 0, 0, 0, 0xff,
  		0xff, 0xc7, 0, 0, 0, 0, 0, 0} },
  	{0, 0x4d, 0, F_D_IN, resp_log_sense, NULL,	/* LOG SENSE */
  	    {10,  0xe3, 0xff, 0xff, 0, 0xff, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0,
  	     0, 0, 0} },
  	{0, 0x25, 0, F_D_IN, resp_readcap, NULL,    /* READ CAPACITY(10) */
  	    {10,  0xe1, 0xff, 0xff, 0xff, 0xff, 0, 0, 0x1, 0xc7, 0, 0, 0, 0,
  	     0, 0} },
  	{ARRAY_SIZE(read_iarr), 0x88, 0, F_D_IN | FF_MEDIA_IO, /* READ(16) */
  	    resp_read_dt0, read_iarr, {16,  0xfe, 0xff, 0xff, 0xff, 0xff,
  	    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc7} },
  /* 10 */
  	{ARRAY_SIZE(write_iarr), 0x8a, 0, F_D_OUT | FF_MEDIA_IO,
  	    resp_write_dt0, write_iarr,			/* WRITE(16) */
  		{16,  0xfa, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  		 0xff, 0xff, 0xff, 0xff, 0xff, 0xc7} },
  	{0, 0x1b, 0, F_SSU_DELAY, resp_start_stop, NULL,/* START STOP UNIT */
  	    {6,  0x1, 0, 0xf, 0xf7, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
  	{ARRAY_SIZE(sa_in_16_iarr), 0x9e, 0x10, F_SA_LOW | F_D_IN,
  	    resp_readcap16, sa_in_16_iarr, /* SA_IN(16), READ CAPACITY(16) */
  		{16,  0x10, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  		 0xff, 0xff, 0xff, 0xff, 0x1, 0xc7} },
  	{0, 0x9f, 0x12, F_SA_LOW | F_D_OUT | FF_MEDIA_IO, resp_write_scat,
  	    NULL, {16,  0x12, 0xf9, 0x0, 0xff, 0xff, 0, 0, 0xff, 0xff, 0xff,
  	    0xff, 0xff, 0xff, 0xff, 0xc7} },  /* SA_OUT(16), WRITE SCAT(16) */
  	{ARRAY_SIZE(maint_in_iarr), 0xa3, 0xa, F_SA_LOW | F_D_IN,
  	    resp_report_tgtpgs,	/* MAINT IN, REPORT TARGET PORT GROUPS */
  		maint_in_iarr, {12,  0xea, 0, 0, 0, 0, 0xff, 0xff, 0xff,
  				0xff, 0, 0xc7, 0, 0, 0, 0} },
  /* 15 */
  	{0, 0, 0, F_INV_OP | FF_RESPOND, NULL, NULL, /* MAINT OUT */
  	    {0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
  	{0, 0x2f, 0, F_D_OUT_MAYBE | FF_MEDIA_IO, NULL, NULL, /* VERIFY(10) */
  	    {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc7,
  	     0, 0, 0, 0, 0, 0} },
  	{ARRAY_SIZE(vl_iarr), 0x7f, 0x9, F_SA_HIGH | F_D_IN | FF_MEDIA_IO,
  	    resp_read_dt0, vl_iarr,	/* VARIABLE LENGTH, READ(32) */
  	    {32,  0xc7, 0, 0, 0, 0, 0x3f, 0x18, 0x0, 0x9, 0xfe, 0, 0xff, 0xff,
  	     0xff, 0xff} },
  	{ARRAY_SIZE(reserve_iarr), 0x56, 0, F_D_OUT,
  	    NULL, reserve_iarr,	/* RESERVE(10) <no response function> */
  	    {10,  0xff, 0xff, 0xff, 0, 0, 0, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0,
  	     0} },
  	{ARRAY_SIZE(release_iarr), 0x57, 0, F_D_OUT,
  	    NULL, release_iarr, /* RELEASE(10) <no response function> */
  	    {10,  0x13, 0xff, 0xff, 0, 0, 0, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0,
  	     0} },
  /* 20 */
  	{0, 0x1e, 0, 0, NULL, NULL, /* ALLOW REMOVAL */
  	    {6,  0, 0, 0, 0x3, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
  	{0, 0x1, 0, 0, resp_start_stop, NULL, /* REWIND ?? */
  	    {6,  0x1, 0, 0, 0, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
  	{0, 0, 0, F_INV_OP | FF_RESPOND, NULL, NULL, /* ATA_PT */
  	    {0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
  	{0, 0x1d, F_D_OUT, 0, NULL, NULL,	/* SEND DIAGNOSTIC */
  	    {6,  0xf7, 0, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
  	{0, 0x42, 0, F_D_OUT | FF_MEDIA_IO, resp_unmap, NULL, /* UNMAP */
  	    {10,  0x1, 0, 0, 0, 0, 0x3f, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0} },
  /* 25 */
  	{0, 0x3b, 0, F_D_OUT_MAYBE, resp_write_buffer, NULL,
  	    {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc7, 0, 0,
  	     0, 0, 0, 0} },			/* WRITE_BUFFER */
  	{ARRAY_SIZE(write_same_iarr), 0x41, 0, F_D_OUT_MAYBE | FF_MEDIA_IO,
  	    resp_write_same_10, write_same_iarr,	/* WRITE SAME(10) */
  		{10,  0xff, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff, 0xff, 0xc7, 0,
  		 0, 0, 0, 0, 0} },
  	{ARRAY_SIZE(sync_cache_iarr), 0x35, 0, F_SYNC_DELAY | F_M_ACCESS,
  	    resp_sync_cache, sync_cache_iarr,
  	    {10,  0x7, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff, 0xff, 0xc7, 0, 0,
  	     0, 0, 0, 0} },			/* SYNC_CACHE (10) */
  	{0, 0x89, 0, F_D_OUT | FF_MEDIA_IO, resp_comp_write, NULL,
  	    {16,  0xf8, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0, 0,
  	     0, 0xff, 0x3f, 0xc7} },		/* COMPARE AND WRITE */
  
  /* 29 */
  	{0xff, 0, 0, 0, NULL, NULL,		/* terminating element */
  	    {0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
  };
  
  static int sdebug_add_host = DEF_NUM_HOST;
  static int sdebug_ato = DEF_ATO;
  static int sdebug_cdb_len = DEF_CDB_LEN;
  static int sdebug_jdelay = DEF_JDELAY;	/* if > 0 then unit is jiffies */
  static int sdebug_dev_size_mb = DEF_DEV_SIZE_MB;
  static int sdebug_dif = DEF_DIF;
  static int sdebug_dix = DEF_DIX;
  static int sdebug_dsense = DEF_D_SENSE;
  static int sdebug_every_nth = DEF_EVERY_NTH;
  static int sdebug_fake_rw = DEF_FAKE_RW;
  static unsigned int sdebug_guard = DEF_GUARD;
  static int sdebug_lowest_aligned = DEF_LOWEST_ALIGNED;
  static int sdebug_max_luns = DEF_MAX_LUNS;
  static int sdebug_max_queue = SDEBUG_CANQUEUE;	/* per submit queue */
  static unsigned int sdebug_medium_error_start = OPT_MEDIUM_ERR_ADDR;
  static int sdebug_medium_error_count = OPT_MEDIUM_ERR_NUM;
  static atomic_t retired_max_queue;	/* if > 0 then was prior max_queue */
  static int sdebug_ndelay = DEF_NDELAY;	/* if > 0 then unit is nanoseconds */
  static int sdebug_no_lun_0 = DEF_NO_LUN_0;
  static int sdebug_no_uld;
  static int sdebug_num_parts = DEF_NUM_PARTS;
  static int sdebug_num_tgts = DEF_NUM_TGTS; /* targets per host */
  static int sdebug_opt_blks = DEF_OPT_BLKS;
  static int sdebug_opts = DEF_OPTS;
  static int sdebug_physblk_exp = DEF_PHYSBLK_EXP;
  static int sdebug_opt_xferlen_exp = DEF_OPT_XFERLEN_EXP;
  static int sdebug_ptype = DEF_PTYPE; /* SCSI peripheral device type */
  static int sdebug_scsi_level = DEF_SCSI_LEVEL;
  static int sdebug_sector_size = DEF_SECTOR_SIZE;
  static int sdebug_virtual_gb = DEF_VIRTUAL_GB;
  static int sdebug_vpd_use_hostno = DEF_VPD_USE_HOSTNO;
  static unsigned int sdebug_lbpu = DEF_LBPU;
  static unsigned int sdebug_lbpws = DEF_LBPWS;
  static unsigned int sdebug_lbpws10 = DEF_LBPWS10;
  static unsigned int sdebug_lbprz = DEF_LBPRZ;
  static unsigned int sdebug_unmap_alignment = DEF_UNMAP_ALIGNMENT;
  static unsigned int sdebug_unmap_granularity = DEF_UNMAP_GRANULARITY;
  static unsigned int sdebug_unmap_max_blocks = DEF_UNMAP_MAX_BLOCKS;
  static unsigned int sdebug_unmap_max_desc = DEF_UNMAP_MAX_DESC;
  static unsigned int sdebug_write_same_length = DEF_WRITESAME_LENGTH;
  static int sdebug_uuid_ctl = DEF_UUID_CTL;
  static bool sdebug_removable = DEF_REMOVABLE;
  static bool sdebug_clustering;
  static bool sdebug_host_lock = DEF_HOST_LOCK;
  static bool sdebug_strict = DEF_STRICT;
  static bool sdebug_any_injecting_opt;
  static bool sdebug_verbose;
  static bool have_dif_prot;
  static bool write_since_sync;
  static bool sdebug_statistics = DEF_STATISTICS;
  static bool sdebug_wp;
  
  static unsigned int sdebug_store_sectors;
  static sector_t sdebug_capacity;	/* in sectors */
  
  /* old BIOS stuff, kernel may get rid of them but some mode sense pages
     may still need them */
  static int sdebug_heads;		/* heads per disk */
  static int sdebug_cylinders_per;	/* cylinders per surface */
  static int sdebug_sectors_per;		/* sectors per cylinder */
  
  static LIST_HEAD(sdebug_host_list);
  static DEFINE_SPINLOCK(sdebug_host_list_lock);
  
  static unsigned char *fake_storep;	/* ramdisk storage */
  static struct t10_pi_tuple *dif_storep;	/* protection info */
  static void *map_storep;		/* provisioning map */
  
  static unsigned long map_size;
  static int num_aborts;
  static int num_dev_resets;
  static int num_target_resets;
  static int num_bus_resets;
  static int num_host_resets;
  static int dix_writes;
  static int dix_reads;
  static int dif_errors;
  
  static int submit_queues = DEF_SUBMIT_QUEUES;  /* > 1 for multi-queue (mq) */
  static struct sdebug_queue *sdebug_q_arr;  /* ptr to array of submit queues */
  
  static DEFINE_RWLOCK(atomic_rw);
  
  static char sdebug_proc_name[] = MY_NAME;
  static const char *my_name = MY_NAME;
  
  static struct bus_type pseudo_lld_bus;
  
  static struct device_driver sdebug_driverfs_driver = {
  	.name 		= sdebug_proc_name,
  	.bus		= &pseudo_lld_bus,
  };
  
  static const int check_condition_result =
  		(DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
  
  static const int illegal_condition_result =
  	(DRIVER_SENSE << 24) | (DID_ABORT << 16) | SAM_STAT_CHECK_CONDITION;
  
  static const int device_qfull_result =
  	(DID_OK << 16) | (COMMAND_COMPLETE << 8) | SAM_STAT_TASK_SET_FULL;
  
  
  /* Only do the extra work involved in logical block provisioning if one or
   * more of the lbpu, lbpws or lbpws10 parameters are given and we are doing
   * real reads and writes (i.e. not skipping them for speed).
   */
  static inline bool scsi_debug_lbp(void)
  {
  	return 0 == sdebug_fake_rw &&
  		(sdebug_lbpu || sdebug_lbpws || sdebug_lbpws10);
  }
  
  static void *lba2fake_store(unsigned long long lba)
  {
  	lba = do_div(lba, sdebug_store_sectors);
  
  	return fake_storep + lba * sdebug_sector_size;
  }
  
  static struct t10_pi_tuple *dif_store(sector_t sector)
  {
  	sector = sector_div(sector, sdebug_store_sectors);
  
  	return dif_storep + sector;
  }
  
  static void sdebug_max_tgts_luns(void)
  {
  	struct sdebug_host_info *sdbg_host;
  	struct Scsi_Host *hpnt;
  
  	spin_lock(&sdebug_host_list_lock);
  	list_for_each_entry(sdbg_host, &sdebug_host_list, host_list) {
  		hpnt = sdbg_host->shost;
  		if ((hpnt->this_id >= 0) &&
  		    (sdebug_num_tgts > hpnt->this_id))
  			hpnt->max_id = sdebug_num_tgts + 1;
  		else
  			hpnt->max_id = sdebug_num_tgts;
  		/* sdebug_max_luns; */
  		hpnt->max_lun = SCSI_W_LUN_REPORT_LUNS + 1;
  	}
  	spin_unlock(&sdebug_host_list_lock);
  }
  
  enum sdeb_cmd_data {SDEB_IN_DATA = 0, SDEB_IN_CDB = 1};
  
  /* Set in_bit to -1 to indicate no bit position of invalid field */
  static void mk_sense_invalid_fld(struct scsi_cmnd *scp,
  				 enum sdeb_cmd_data c_d,
  				 int in_byte, int in_bit)
  {
  	unsigned char *sbuff;
  	u8 sks[4];
  	int sl, asc;
  
  	sbuff = scp->sense_buffer;
  	if (!sbuff) {
  		sdev_printk(KERN_ERR, scp->device,
  			    "%s: sense_buffer is NULL\n", __func__);
  		return;
  	}
  	asc = c_d ? INVALID_FIELD_IN_CDB : INVALID_FIELD_IN_PARAM_LIST;
  	memset(sbuff, 0, SCSI_SENSE_BUFFERSIZE);
  	scsi_build_sense_buffer(sdebug_dsense, sbuff, ILLEGAL_REQUEST, asc, 0);
  	memset(sks, 0, sizeof(sks));
  	sks[0] = 0x80;
  	if (c_d)
  		sks[0] |= 0x40;
  	if (in_bit >= 0) {
  		sks[0] |= 0x8;
  		sks[0] |= 0x7 & in_bit;
  	}
  	put_unaligned_be16(in_byte, sks + 1);
  	if (sdebug_dsense) {
  		sl = sbuff[7] + 8;
  		sbuff[7] = sl;
  		sbuff[sl] = 0x2;
  		sbuff[sl + 1] = 0x6;
  		memcpy(sbuff + sl + 4, sks, 3);
  	} else
  		memcpy(sbuff + 15, sks, 3);
  	if (sdebug_verbose)
  		sdev_printk(KERN_INFO, scp->device, "%s:  [sense_key,asc,ascq"
  			    "]: [0x5,0x%x,0x0] %c byte=%d, bit=%d\n",
  			    my_name, asc, c_d ? 'C' : 'D', in_byte, in_bit);
  }
  
  static void mk_sense_buffer(struct scsi_cmnd *scp, int key, int asc, int asq)
  {
  	unsigned char *sbuff;
  
  	sbuff = scp->sense_buffer;
  	if (!sbuff) {
  		sdev_printk(KERN_ERR, scp->device,
  			    "%s: sense_buffer is NULL\n", __func__);
  		return;
  	}
  	memset(sbuff, 0, SCSI_SENSE_BUFFERSIZE);
  
  	scsi_build_sense_buffer(sdebug_dsense, sbuff, key, asc, asq);
  
  	if (sdebug_verbose)
  		sdev_printk(KERN_INFO, scp->device,
  			    "%s:  [sense_key,asc,ascq]: [0x%x,0x%x,0x%x]\n",
  			    my_name, key, asc, asq);
  }
  
  static void mk_sense_invalid_opcode(struct scsi_cmnd *scp)
  {
  	mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_OPCODE, 0);
  }
  
  static int scsi_debug_ioctl(struct scsi_device *dev, unsigned int cmd,
  			    void __user *arg)
  {
  	if (sdebug_verbose) {
  		if (0x1261 == cmd)
  			sdev_printk(KERN_INFO, dev,
  				    "%s: BLKFLSBUF [0x1261]\n", __func__);
  		else if (0x5331 == cmd)
  			sdev_printk(KERN_INFO, dev,
  				    "%s: CDROM_GET_CAPABILITY [0x5331]\n",
  				    __func__);
  		else
  			sdev_printk(KERN_INFO, dev, "%s: cmd=0x%x\n",
  				    __func__, cmd);
  	}
  	return -EINVAL;
  	/* return -ENOTTY; // correct return but upsets fdisk */
  }
  
  static void config_cdb_len(struct scsi_device *sdev)
  {
  	switch (sdebug_cdb_len) {
  	case 6:	/* suggest 6 byte READ, WRITE and MODE SENSE/SELECT */
  		sdev->use_10_for_rw = false;
  		sdev->use_16_for_rw = false;
  		sdev->use_10_for_ms = false;
  		break;
  	case 10: /* suggest 10 byte RWs and 6 byte MODE SENSE/SELECT */
  		sdev->use_10_for_rw = true;
  		sdev->use_16_for_rw = false;
  		sdev->use_10_for_ms = false;
  		break;
  	case 12: /* suggest 10 byte RWs and 10 byte MODE SENSE/SELECT */
  		sdev->use_10_for_rw = true;
  		sdev->use_16_for_rw = false;
  		sdev->use_10_for_ms = true;
  		break;
  	case 16:
  		sdev->use_10_for_rw = false;
  		sdev->use_16_for_rw = true;
  		sdev->use_10_for_ms = true;
  		break;
  	case 32: /* No knobs to suggest this so same as 16 for now */
  		sdev->use_10_for_rw = false;
  		sdev->use_16_for_rw = true;
  		sdev->use_10_for_ms = true;
  		break;
  	default:
  		pr_warn("unexpected cdb_len=%d, force to 10\n",
  			sdebug_cdb_len);
  		sdev->use_10_for_rw = true;
  		sdev->use_16_for_rw = false;
  		sdev->use_10_for_ms = false;
  		sdebug_cdb_len = 10;
  		break;
  	}
  }
  
  static void all_config_cdb_len(void)
  {
  	struct sdebug_host_info *sdbg_host;
  	struct Scsi_Host *shost;
  	struct scsi_device *sdev;
  
  	spin_lock(&sdebug_host_list_lock);
  	list_for_each_entry(sdbg_host, &sdebug_host_list, host_list) {
  		shost = sdbg_host->shost;
  		shost_for_each_device(sdev, shost) {
  			config_cdb_len(sdev);
  		}
  	}
  	spin_unlock(&sdebug_host_list_lock);
  }
  
  static void clear_luns_changed_on_target(struct sdebug_dev_info *devip)
  {
  	struct sdebug_host_info *sdhp;
  	struct sdebug_dev_info *dp;
  
  	spin_lock(&sdebug_host_list_lock);
  	list_for_each_entry(sdhp, &sdebug_host_list, host_list) {
  		list_for_each_entry(dp, &sdhp->dev_info_list, dev_list) {
  			if ((devip->sdbg_host == dp->sdbg_host) &&
  			    (devip->target == dp->target))
  				clear_bit(SDEBUG_UA_LUNS_CHANGED, dp->uas_bm);
  		}
  	}
  	spin_unlock(&sdebug_host_list_lock);
  }
  
  static int make_ua(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
  {
  	int k;
  
  	k = find_first_bit(devip->uas_bm, SDEBUG_NUM_UAS);
  	if (k != SDEBUG_NUM_UAS) {
  		const char *cp = NULL;
  
  		switch (k) {
  		case SDEBUG_UA_POR:
  			mk_sense_buffer(scp, UNIT_ATTENTION, UA_RESET_ASC,
  					POWER_ON_RESET_ASCQ);
  			if (sdebug_verbose)
  				cp = "power on reset";
  			break;
  		case SDEBUG_UA_BUS_RESET:
  			mk_sense_buffer(scp, UNIT_ATTENTION, UA_RESET_ASC,
  					BUS_RESET_ASCQ);
  			if (sdebug_verbose)
  				cp = "bus reset";
  			break;
  		case SDEBUG_UA_MODE_CHANGED:
  			mk_sense_buffer(scp, UNIT_ATTENTION, UA_CHANGED_ASC,
  					MODE_CHANGED_ASCQ);
  			if (sdebug_verbose)
  				cp = "mode parameters changed";
  			break;
  		case SDEBUG_UA_CAPACITY_CHANGED:
  			mk_sense_buffer(scp, UNIT_ATTENTION, UA_CHANGED_ASC,
  					CAPACITY_CHANGED_ASCQ);
  			if (sdebug_verbose)
  				cp = "capacity data changed";
  			break;
  		case SDEBUG_UA_MICROCODE_CHANGED:
  			mk_sense_buffer(scp, UNIT_ATTENTION,
  					TARGET_CHANGED_ASC,
  					MICROCODE_CHANGED_ASCQ);
  			if (sdebug_verbose)
  				cp = "microcode has been changed";
  			break;
  		case SDEBUG_UA_MICROCODE_CHANGED_WO_RESET:
  			mk_sense_buffer(scp, UNIT_ATTENTION,
  					TARGET_CHANGED_ASC,
  					MICROCODE_CHANGED_WO_RESET_ASCQ);
  			if (sdebug_verbose)
  				cp = "microcode has been changed without reset";
  			break;
  		case SDEBUG_UA_LUNS_CHANGED:
  			/*
  			 * SPC-3 behavior is to report a UNIT ATTENTION with
  			 * ASC/ASCQ REPORTED LUNS DATA HAS CHANGED on every LUN
  			 * on the target, until a REPORT LUNS command is
  			 * received.  SPC-4 behavior is to report it only once.
  			 * NOTE:  sdebug_scsi_level does not use the same
  			 * values as struct scsi_device->scsi_level.
  			 */
  			if (sdebug_scsi_level >= 6)	/* SPC-4 and above */
  				clear_luns_changed_on_target(devip);
  			mk_sense_buffer(scp, UNIT_ATTENTION,
  					TARGET_CHANGED_ASC,
  					LUNS_CHANGED_ASCQ);
  			if (sdebug_verbose)
  				cp = "reported luns data has changed";
  			break;
  		default:
  			pr_warn("unexpected unit attention code=%d\n", k);
  			if (sdebug_verbose)
  				cp = "unknown";
  			break;
  		}
  		clear_bit(k, devip->uas_bm);
  		if (sdebug_verbose)
  			sdev_printk(KERN_INFO, scp->device,
  				   "%s reports: Unit attention: %s\n",
  				   my_name, cp);
  		return check_condition_result;
  	}
  	return 0;
  }
  
  /* Build SCSI "data-in" buffer. Returns 0 if ok else (DID_ERROR << 16). */
  static int fill_from_dev_buffer(struct scsi_cmnd *scp, unsigned char *arr,
  				int arr_len)
  {
  	int act_len;
  	struct scsi_data_buffer *sdb = &scp->sdb;
  
  	if (!sdb->length)
  		return 0;
  	if (scp->sc_data_direction != DMA_FROM_DEVICE)
  		return DID_ERROR << 16;
  
  	act_len = sg_copy_from_buffer(sdb->table.sgl, sdb->table.nents,
  				      arr, arr_len);
  	scsi_set_resid(scp, scsi_bufflen(scp) - act_len);
  
  	return 0;
  }
  
  /* Partial build of SCSI "data-in" buffer. Returns 0 if ok else
   * (DID_ERROR << 16). Can write to offset in data-in buffer. If multiple
   * calls, not required to write in ascending offset order. Assumes resid
   * set to scsi_bufflen() prior to any calls.
   */
  static int p_fill_from_dev_buffer(struct scsi_cmnd *scp, const void *arr,
  				  int arr_len, unsigned int off_dst)
  {
  	unsigned int act_len, n;
  	struct scsi_data_buffer *sdb = &scp->sdb;
  	off_t skip = off_dst;
  
  	if (sdb->length <= off_dst)
  		return 0;
  	if (scp->sc_data_direction != DMA_FROM_DEVICE)
  		return DID_ERROR << 16;
  
  	act_len = sg_pcopy_from_buffer(sdb->table.sgl, sdb->table.nents,
  				       arr, arr_len, skip);
  	pr_debug("%s: off_dst=%u, scsi_bufflen=%u, act_len=%u, resid=%d\n",
  		 __func__, off_dst, scsi_bufflen(scp), act_len,
  		 scsi_get_resid(scp));
  	n = scsi_bufflen(scp) - (off_dst + act_len);
  	scsi_set_resid(scp, min(scsi_get_resid(scp), n));
  	return 0;
  }
  
  /* Fetches from SCSI "data-out" buffer. Returns number of bytes fetched into
   * 'arr' or -1 if error.
   */
  static int fetch_to_dev_buffer(struct scsi_cmnd *scp, unsigned char *arr,
  			       int arr_len)
  {
  	if (!scsi_bufflen(scp))
  		return 0;
  	if (scp->sc_data_direction != DMA_TO_DEVICE)
  		return -1;
  
  	return scsi_sg_copy_to_buffer(scp, arr, arr_len);
  }
  
  
  static char sdebug_inq_vendor_id[9] = "Linux   ";
  static char sdebug_inq_product_id[17] = "scsi_debug      ";
  static char sdebug_inq_product_rev[5] = SDEBUG_VERSION;
  /* Use some locally assigned NAAs for SAS addresses. */
  static const u64 naa3_comp_a = 0x3222222000000000ULL;
  static const u64 naa3_comp_b = 0x3333333000000000ULL;
  static const u64 naa3_comp_c = 0x3111111000000000ULL;
  
  /* Device identification VPD page. Returns number of bytes placed in arr */
  static int inquiry_vpd_83(unsigned char *arr, int port_group_id,
  			  int target_dev_id, int dev_id_num,
  			  const char *dev_id_str, int dev_id_str_len,
  			  const uuid_t *lu_name)
  {
  	int num, port_a;
  	char b[32];
  
  	port_a = target_dev_id + 1;
  	/* T10 vendor identifier field format (faked) */
  	arr[0] = 0x2;	/* ASCII */
  	arr[1] = 0x1;
  	arr[2] = 0x0;
  	memcpy(&arr[4], sdebug_inq_vendor_id, 8);
  	memcpy(&arr[12], sdebug_inq_product_id, 16);
  	memcpy(&arr[28], dev_id_str, dev_id_str_len);
  	num = 8 + 16 + dev_id_str_len;
  	arr[3] = num;
  	num += 4;
  	if (dev_id_num >= 0) {
  		if (sdebug_uuid_ctl) {
  			/* Locally assigned UUID */
  			arr[num++] = 0x1;  /* binary (not necessarily sas) */
  			arr[num++] = 0xa;  /* PIV=0, lu, naa */
  			arr[num++] = 0x0;
  			arr[num++] = 0x12;
  			arr[num++] = 0x10; /* uuid type=1, locally assigned */
  			arr[num++] = 0x0;
  			memcpy(arr + num, lu_name, 16);
  			num += 16;
  		} else {
  			/* NAA-3, Logical unit identifier (binary) */
  			arr[num++] = 0x1;  /* binary (not necessarily sas) */
  			arr[num++] = 0x3;  /* PIV=0, lu, naa */
  			arr[num++] = 0x0;
  			arr[num++] = 0x8;
  			put_unaligned_be64(naa3_comp_b + dev_id_num, arr + num);
  			num += 8;
  		}
  		/* Target relative port number */
  		arr[num++] = 0x61;	/* proto=sas, binary */
  		arr[num++] = 0x94;	/* PIV=1, target port, rel port */
  		arr[num++] = 0x0;	/* reserved */
  		arr[num++] = 0x4;	/* length */
  		arr[num++] = 0x0;	/* reserved */
  		arr[num++] = 0x0;	/* reserved */
  		arr[num++] = 0x0;
  		arr[num++] = 0x1;	/* relative port A */
  	}
  	/* NAA-3, Target port identifier */
  	arr[num++] = 0x61;	/* proto=sas, binary */
  	arr[num++] = 0x93;	/* piv=1, target port, naa */
  	arr[num++] = 0x0;
  	arr[num++] = 0x8;
  	put_unaligned_be64(naa3_comp_a + port_a, arr + num);
  	num += 8;
  	/* NAA-3, Target port group identifier */
  	arr[num++] = 0x61;	/* proto=sas, binary */
  	arr[num++] = 0x95;	/* piv=1, target port group id */
  	arr[num++] = 0x0;
  	arr[num++] = 0x4;
  	arr[num++] = 0;
  	arr[num++] = 0;
  	put_unaligned_be16(port_group_id, arr + num);
  	num += 2;
  	/* NAA-3, Target device identifier */
  	arr[num++] = 0x61;	/* proto=sas, binary */
  	arr[num++] = 0xa3;	/* piv=1, target device, naa */
  	arr[num++] = 0x0;
  	arr[num++] = 0x8;
  	put_unaligned_be64(naa3_comp_a + target_dev_id, arr + num);
  	num += 8;
  	/* SCSI name string: Target device identifier */
  	arr[num++] = 0x63;	/* proto=sas, UTF-8 */
  	arr[num++] = 0xa8;	/* piv=1, target device, SCSI name string */
  	arr[num++] = 0x0;
  	arr[num++] = 24;
  	memcpy(arr + num, "naa.32222220", 12);
  	num += 12;
  	snprintf(b, sizeof(b), "%08X", target_dev_id);
  	memcpy(arr + num, b, 8);
  	num += 8;
  	memset(arr + num, 0, 4);
  	num += 4;
  	return num;
  }
  
  static unsigned char vpd84_data[] = {
  /* from 4th byte */ 0x22,0x22,0x22,0x0,0xbb,0x0,
      0x22,0x22,0x22,0x0,0xbb,0x1,
      0x22,0x22,0x22,0x0,0xbb,0x2,
  };
  
  /*  Software interface identification VPD page */
  static int inquiry_vpd_84(unsigned char *arr)
  {
  	memcpy(arr, vpd84_data, sizeof(vpd84_data));
  	return sizeof(vpd84_data);
  }
  
  /* Management network addresses VPD page */
  static int inquiry_vpd_85(unsigned char *arr)
  {
  	int num = 0;
  	const char *na1 = "https://www.kernel.org/config";
  	const char *na2 = "http://www.kernel.org/log";
  	int plen, olen;
  
  	arr[num++] = 0x1;	/* lu, storage config */
  	arr[num++] = 0x0;	/* reserved */
  	arr[num++] = 0x0;
  	olen = strlen(na1);
  	plen = olen + 1;
  	if (plen % 4)
  		plen = ((plen / 4) + 1) * 4;
  	arr[num++] = plen;	/* length, null termianted, padded */
  	memcpy(arr + num, na1, olen);
  	memset(arr + num + olen, 0, plen - olen);
  	num += plen;
  
  	arr[num++] = 0x4;	/* lu, logging */
  	arr[num++] = 0x0;	/* reserved */
  	arr[num++] = 0x0;
  	olen = strlen(na2);
  	plen = olen + 1;
  	if (plen % 4)
  		plen = ((plen / 4) + 1) * 4;
  	arr[num++] = plen;	/* length, null terminated, padded */
  	memcpy(arr + num, na2, olen);
  	memset(arr + num + olen, 0, plen - olen);
  	num += plen;
  
  	return num;
  }
  
  /* SCSI ports VPD page */
  static int inquiry_vpd_88(unsigned char *arr, int target_dev_id)
  {
  	int num = 0;
  	int port_a, port_b;
  
  	port_a = target_dev_id + 1;
  	port_b = port_a + 1;
  	arr[num++] = 0x0;	/* reserved */
  	arr[num++] = 0x0;	/* reserved */
  	arr[num++] = 0x0;
  	arr[num++] = 0x1;	/* relative port 1 (primary) */
  	memset(arr + num, 0, 6);
  	num += 6;
  	arr[num++] = 0x0;
  	arr[num++] = 12;	/* length tp descriptor */
  	/* naa-5 target port identifier (A) */
  	arr[num++] = 0x61;	/* proto=sas, binary */
  	arr[num++] = 0x93;	/* PIV=1, target port, NAA */
  	arr[num++] = 0x0;	/* reserved */
  	arr[num++] = 0x8;	/* length */
  	put_unaligned_be64(naa3_comp_a + port_a, arr + num);
  	num += 8;
  	arr[num++] = 0x0;	/* reserved */
  	arr[num++] = 0x0;	/* reserved */
  	arr[num++] = 0x0;
  	arr[num++] = 0x2;	/* relative port 2 (secondary) */
  	memset(arr + num, 0, 6);
  	num += 6;
  	arr[num++] = 0x0;
  	arr[num++] = 12;	/* length tp descriptor */
  	/* naa-5 target port identifier (B) */
  	arr[num++] = 0x61;	/* proto=sas, binary */
  	arr[num++] = 0x93;	/* PIV=1, target port, NAA */
  	arr[num++] = 0x0;	/* reserved */
  	arr[num++] = 0x8;	/* length */
  	put_unaligned_be64(naa3_comp_a + port_b, arr + num);
  	num += 8;
  
  	return num;
  }
  
  
  static unsigned char vpd89_data[] = {
  /* from 4th byte */ 0,0,0,0,
  'l','i','n','u','x',' ',' ',' ',
  'S','A','T',' ','s','c','s','i','_','d','e','b','u','g',' ',' ',
  '1','2','3','4',
  0x34,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,
  0xec,0,0,0,
  0x5a,0xc,0xff,0x3f,0x37,0xc8,0x10,0,0,0,0,0,0x3f,0,0,0,
  0,0,0,0,0x58,0x58,0x58,0x58,0x58,0x58,0x58,0x58,0x20,0x20,0x20,0x20,
  0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0,0,0,0x40,0x4,0,0x2e,0x33,
  0x38,0x31,0x20,0x20,0x20,0x20,0x54,0x53,0x38,0x33,0x30,0x30,0x33,0x31,
  0x53,0x41,
  0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,
  0x20,0x20,
  0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,0x20,
  0x10,0x80,
  0,0,0,0x2f,0,0,0,0x2,0,0x2,0x7,0,0xff,0xff,0x1,0,
  0x3f,0,0xc1,0xff,0x3e,0,0x10,0x1,0xb0,0xf8,0x50,0x9,0,0,0x7,0,
  0x3,0,0x78,0,0x78,0,0xf0,0,0x78,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0x2,0,0,0,0,0,0,0,
  0x7e,0,0x1b,0,0x6b,0x34,0x1,0x7d,0x3,0x40,0x69,0x34,0x1,0x3c,0x3,0x40,
  0x7f,0x40,0,0,0,0,0xfe,0xfe,0,0,0,0,0,0xfe,0,0,
  0,0,0,0,0,0,0,0,0xb0,0xf8,0x50,0x9,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0x1,0,0xb0,0xf8,0x50,0x9,0xb0,0xf8,0x50,0x9,0x20,0x20,0x2,0,0xb6,0x42,
  0,0x80,0x8a,0,0x6,0x3c,0xa,0x3c,0xff,0xff,0xc6,0x7,0,0x1,0,0x8,
  0xf0,0xf,0,0x10,0x2,0,0x30,0,0,0,0,0,0,0,0x6,0xfe,
  0,0,0x2,0,0x50,0,0x8a,0,0x4f,0x95,0,0,0x21,0,0xb,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  0,0,0,0,0,0,0,0,0,0,0,0,0,0,0xa5,0x51,
  };
  
  /* ATA Information VPD page */
  static int inquiry_vpd_89(unsigned char *arr)
  {
  	memcpy(arr, vpd89_data, sizeof(vpd89_data));
  	return sizeof(vpd89_data);
  }
  
  
  static unsigned char vpdb0_data[] = {
  	/* from 4th byte */ 0,0,0,4, 0,0,0x4,0, 0,0,0,64,
  	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  	0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  };
  
  /* Block limits VPD page (SBC-3) */
  static int inquiry_vpd_b0(unsigned char *arr)
  {
  	unsigned int gran;
  
  	memcpy(arr, vpdb0_data, sizeof(vpdb0_data));
  
  	/* Optimal transfer length granularity */
  	if (sdebug_opt_xferlen_exp != 0 &&
  	    sdebug_physblk_exp < sdebug_opt_xferlen_exp)
  		gran = 1 << sdebug_opt_xferlen_exp;
  	else
  		gran = 1 << sdebug_physblk_exp;
  	put_unaligned_be16(gran, arr + 2);
  
  	/* Maximum Transfer Length */
  	if (sdebug_store_sectors > 0x400)
  		put_unaligned_be32(sdebug_store_sectors, arr + 4);
  
  	/* Optimal Transfer Length */
  	put_unaligned_be32(sdebug_opt_blks, &arr[8]);
  
  	if (sdebug_lbpu) {
  		/* Maximum Unmap LBA Count */
  		put_unaligned_be32(sdebug_unmap_max_blocks, &arr[16]);
  
  		/* Maximum Unmap Block Descriptor Count */
  		put_unaligned_be32(sdebug_unmap_max_desc, &arr[20]);
  	}
  
  	/* Unmap Granularity Alignment */
  	if (sdebug_unmap_alignment) {
  		put_unaligned_be32(sdebug_unmap_alignment, &arr[28]);
  		arr[28] |= 0x80; /* UGAVALID */
  	}
  
  	/* Optimal Unmap Granularity */
  	put_unaligned_be32(sdebug_unmap_granularity, &arr[24]);
  
  	/* Maximum WRITE SAME Length */
  	put_unaligned_be64(sdebug_write_same_length, &arr[32]);
  
  	return 0x3c; /* Mandatory page length for Logical Block Provisioning */
  
  	return sizeof(vpdb0_data);
  }
  
  /* Block device characteristics VPD page (SBC-3) */
  static int inquiry_vpd_b1(unsigned char *arr)
  {
  	memset(arr, 0, 0x3c);
  	arr[0] = 0;
  	arr[1] = 1;	/* non rotating medium (e.g. solid state) */
  	arr[2] = 0;
  	arr[3] = 5;	/* less than 1.8" */
  
  	return 0x3c;
  }
  
  /* Logical block provisioning VPD page (SBC-4) */
  static int inquiry_vpd_b2(unsigned char *arr)
  {
  	memset(arr, 0, 0x4);
  	arr[0] = 0;			/* threshold exponent */
  	if (sdebug_lbpu)
  		arr[1] = 1 << 7;
  	if (sdebug_lbpws)
  		arr[1] |= 1 << 6;
  	if (sdebug_lbpws10)
  		arr[1] |= 1 << 5;
  	if (sdebug_lbprz && scsi_debug_lbp())
  		arr[1] |= (sdebug_lbprz & 0x7) << 2;  /* sbc4r07 and later */
  	/* anc_sup=0; dp=0 (no provisioning group descriptor) */
  	/* minimum_percentage=0; provisioning_type=0 (unknown) */
  	/* threshold_percentage=0 */
  	return 0x4;
  }
  
  #define SDEBUG_LONG_INQ_SZ 96
  #define SDEBUG_MAX_INQ_ARR_SZ 584
  
  static int resp_inquiry(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
  {
  	unsigned char pq_pdt;
  	unsigned char *arr;
  	unsigned char *cmd = scp->cmnd;
  	int alloc_len, n, ret;
  	bool have_wlun, is_disk;
  
  	alloc_len = get_unaligned_be16(cmd + 3);
  	arr = kzalloc(SDEBUG_MAX_INQ_ARR_SZ, GFP_ATOMIC);
  	if (! arr)
  		return DID_REQUEUE << 16;
  	is_disk = (sdebug_ptype == TYPE_DISK);
  	have_wlun = scsi_is_wlun(scp->device->lun);
  	if (have_wlun)
  		pq_pdt = TYPE_WLUN;	/* present, wlun */
  	else if (sdebug_no_lun_0 && (devip->lun == SDEBUG_LUN_0_VAL))
  		pq_pdt = 0x7f;	/* not present, PQ=3, PDT=0x1f */
  	else
  		pq_pdt = (sdebug_ptype & 0x1f);
  	arr[0] = pq_pdt;
  	if (0x2 & cmd[1]) {  /* CMDDT bit set */
  		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 1, 1);
  		kfree(arr);
  		return check_condition_result;
  	} else if (0x1 & cmd[1]) {  /* EVPD bit set */
  		int lu_id_num, port_group_id, target_dev_id, len;
  		char lu_id_str[6];
  		int host_no = devip->sdbg_host->shost->host_no;
  		
  		port_group_id = (((host_no + 1) & 0x7f) << 8) +
  		    (devip->channel & 0x7f);
  		if (sdebug_vpd_use_hostno == 0)
  			host_no = 0;
  		lu_id_num = have_wlun ? -1 : (((host_no + 1) * 2000) +
  			    (devip->target * 1000) + devip->lun);
  		target_dev_id = ((host_no + 1) * 2000) +
  				 (devip->target * 1000) - 3;
  		len = scnprintf(lu_id_str, 6, "%d", lu_id_num);
  		if (0 == cmd[2]) { /* supported vital product data pages */
  			arr[1] = cmd[2];	/*sanity */
  			n = 4;
  			arr[n++] = 0x0;   /* this page */
  			arr[n++] = 0x80;  /* unit serial number */
  			arr[n++] = 0x83;  /* device identification */
  			arr[n++] = 0x84;  /* software interface ident. */
  			arr[n++] = 0x85;  /* management network addresses */
  			arr[n++] = 0x86;  /* extended inquiry */
  			arr[n++] = 0x87;  /* mode page policy */
  			arr[n++] = 0x88;  /* SCSI ports */
  			if (is_disk) {	  /* SBC only */
  				arr[n++] = 0x89;  /* ATA information */
  				arr[n++] = 0xb0;  /* Block limits */
  				arr[n++] = 0xb1;  /* Block characteristics */
  				arr[n++] = 0xb2;  /* Logical Block Prov */
  			}
  			arr[3] = n - 4;	  /* number of supported VPD pages */
  		} else if (0x80 == cmd[2]) { /* unit serial number */
  			arr[1] = cmd[2];	/*sanity */
  			arr[3] = len;
  			memcpy(&arr[4], lu_id_str, len);
  		} else if (0x83 == cmd[2]) { /* device identification */
  			arr[1] = cmd[2];	/*sanity */
  			arr[3] = inquiry_vpd_83(&arr[4], port_group_id,
  						target_dev_id, lu_id_num,
  						lu_id_str, len,
  						&devip->lu_name);
  		} else if (0x84 == cmd[2]) { /* Software interface ident. */
  			arr[1] = cmd[2];	/*sanity */
  			arr[3] = inquiry_vpd_84(&arr[4]);
  		} else if (0x85 == cmd[2]) { /* Management network addresses */
  			arr[1] = cmd[2];	/*sanity */
  			arr[3] = inquiry_vpd_85(&arr[4]);
  		} else if (0x86 == cmd[2]) { /* extended inquiry */
  			arr[1] = cmd[2];	/*sanity */
  			arr[3] = 0x3c;	/* number of following entries */
  			if (sdebug_dif == T10_PI_TYPE3_PROTECTION)
  				arr[4] = 0x4;	/* SPT: GRD_CHK:1 */
  			else if (have_dif_prot)
  				arr[4] = 0x5;   /* SPT: GRD_CHK:1, REF_CHK:1 */
  			else
  				arr[4] = 0x0;   /* no protection stuff */
  			arr[5] = 0x7;   /* head of q, ordered + simple q's */
  		} else if (0x87 == cmd[2]) { /* mode page policy */
  			arr[1] = cmd[2];	/*sanity */
  			arr[3] = 0x8;	/* number of following entries */
  			arr[4] = 0x2;	/* disconnect-reconnect mp */
  			arr[6] = 0x80;	/* mlus, shared */
  			arr[8] = 0x18;	 /* protocol specific lu */
  			arr[10] = 0x82;	 /* mlus, per initiator port */
  		} else if (0x88 == cmd[2]) { /* SCSI Ports */
  			arr[1] = cmd[2];	/*sanity */
  			arr[3] = inquiry_vpd_88(&arr[4], target_dev_id);
  		} else if (is_disk && 0x89 == cmd[2]) { /* ATA information */
  			arr[1] = cmd[2];        /*sanity */
  			n = inquiry_vpd_89(&arr[4]);
  			put_unaligned_be16(n, arr + 2);
  		} else if (is_disk && 0xb0 == cmd[2]) { /* Block limits */
  			arr[1] = cmd[2];        /*sanity */
  			arr[3] = inquiry_vpd_b0(&arr[4]);
  		} else if (is_disk && 0xb1 == cmd[2]) { /* Block char. */
  			arr[1] = cmd[2];        /*sanity */
  			arr[3] = inquiry_vpd_b1(&arr[4]);
  		} else if (is_disk && 0xb2 == cmd[2]) { /* LB Prov. */
  			arr[1] = cmd[2];        /*sanity */
  			arr[3] = inquiry_vpd_b2(&arr[4]);
  		} else {
  			mk_sense_invalid_fld(scp, SDEB_IN_CDB, 2, -1);
  			kfree(arr);
  			return check_condition_result;
  		}
  		len = min(get_unaligned_be16(arr + 2) + 4, alloc_len);
  		ret = fill_from_dev_buffer(scp, arr,
  			    min(len, SDEBUG_MAX_INQ_ARR_SZ));
  		kfree(arr);
  		return ret;
  	}
  	/* drops through here for a standard inquiry */
  	arr[1] = sdebug_removable ? 0x80 : 0;	/* Removable disk */
  	arr[2] = sdebug_scsi_level;
  	arr[3] = 2;    /* response_data_format==2 */
  	arr[4] = SDEBUG_LONG_INQ_SZ - 5;
  	arr[5] = (int)have_dif_prot;	/* PROTECT bit */
  	if (sdebug_vpd_use_hostno == 0)
  		arr[5] |= 0x10; /* claim: implicit TPGS */
  	arr[6] = 0x10; /* claim: MultiP */
  	/* arr[6] |= 0x40; ... claim: EncServ (enclosure services) */
  	arr[7] = 0xa; /* claim: LINKED + CMDQUE */
  	memcpy(&arr[8], sdebug_inq_vendor_id, 8);
  	memcpy(&arr[16], sdebug_inq_product_id, 16);
  	memcpy(&arr[32], sdebug_inq_product_rev, 4);
  	/* Use Vendor Specific area to place driver date in ASCII hex */
  	memcpy(&arr[36], sdebug_version_date, 8);
  	/* version descriptors (2 bytes each) follow */
  	put_unaligned_be16(0xc0, arr + 58);   /* SAM-6 no version claimed */
  	put_unaligned_be16(0x5c0, arr + 60);  /* SPC-5 no version claimed */
  	n = 62;
  	if (is_disk) {		/* SBC-4 no version claimed */
  		put_unaligned_be16(0x600, arr + n);
  		n += 2;
  	} else if (sdebug_ptype == TYPE_TAPE) {	/* SSC-4 rev 3 */
  		put_unaligned_be16(0x525, arr + n);
  		n += 2;
  	}
  	put_unaligned_be16(0x2100, arr + n);	/* SPL-4 no version claimed */
  	ret = fill_from_dev_buffer(scp, arr,
  			    min(alloc_len, SDEBUG_LONG_INQ_SZ));
  	kfree(arr);
  	return ret;
  }
  
  static unsigned char iec_m_pg[] = {0x1c, 0xa, 0x08, 0, 0, 0, 0, 0,
  				   0, 0, 0x0, 0x0};
  
  static int resp_requests(struct scsi_cmnd *scp,
  			 struct sdebug_dev_info *devip)
  {
  	unsigned char *sbuff;
  	unsigned char *cmd = scp->cmnd;
  	unsigned char arr[SCSI_SENSE_BUFFERSIZE];
  	bool dsense;
  	int len = 18;
  
  	memset(arr, 0, sizeof(arr));
  	dsense = !!(cmd[1] & 1);
  	sbuff = scp->sense_buffer;
  	if ((iec_m_pg[2] & 0x4) && (6 == (iec_m_pg[3] & 0xf))) {
  		if (dsense) {
  			arr[0] = 0x72;
  			arr[1] = 0x0;		/* NO_SENSE in sense_key */
  			arr[2] = THRESHOLD_EXCEEDED;
  			arr[3] = 0xff;		/* TEST set and MRIE==6 */
  			len = 8;
  		} else {
  			arr[0] = 0x70;
  			arr[2] = 0x0;		/* NO_SENSE in sense_key */
  			arr[7] = 0xa;   	/* 18 byte sense buffer */
  			arr[12] = THRESHOLD_EXCEEDED;
  			arr[13] = 0xff;		/* TEST set and MRIE==6 */
  		}
  	} else {
  		memcpy(arr, sbuff, SCSI_SENSE_BUFFERSIZE);
  		if (arr[0] >= 0x70 && dsense == sdebug_dsense)
  			;	/* have sense and formats match */
  		else if (arr[0] <= 0x70) {
  			if (dsense) {
  				memset(arr, 0, 8);
  				arr[0] = 0x72;
  				len = 8;
  			} else {
  				memset(arr, 0, 18);
  				arr[0] = 0x70;
  				arr[7] = 0xa;
  			}
  		} else if (dsense) {
  			memset(arr, 0, 8);
  			arr[0] = 0x72;
  			arr[1] = sbuff[2];     /* sense key */
  			arr[2] = sbuff[12];    /* asc */
  			arr[3] = sbuff[13];    /* ascq */
  			len = 8;
  		} else {
  			memset(arr, 0, 18);
  			arr[0] = 0x70;
  			arr[2] = sbuff[1];
  			arr[7] = 0xa;
  			arr[12] = sbuff[1];
  			arr[13] = sbuff[3];
  		}
  
  	}
  	mk_sense_buffer(scp, 0, NO_ADDITIONAL_SENSE, 0);
  	return fill_from_dev_buffer(scp, arr, len);
  }
  
  static int resp_start_stop(struct scsi_cmnd *scp,
  			   struct sdebug_dev_info *devip)
  {
  	unsigned char *cmd = scp->cmnd;
  	int power_cond, stop;
  	bool changing;
  
  	power_cond = (cmd[4] & 0xf0) >> 4;
  	if (power_cond) {
  		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 4, 7);
  		return check_condition_result;
  	}
  	stop = !(cmd[4] & 1);
  	changing = atomic_read(&devip->stopped) == !stop;
  	atomic_xchg(&devip->stopped, stop);
  	if (!changing || cmd[1] & 0x1)  /* state unchanged or IMMED set */
  		return SDEG_RES_IMMED_MASK;
  	else
  		return 0;
  }
  
  static sector_t get_sdebug_capacity(void)
  {
  	static const unsigned int gibibyte = 1073741824;
  
  	if (sdebug_virtual_gb > 0)
  		return (sector_t)sdebug_virtual_gb *
  			(gibibyte / sdebug_sector_size);
  	else
  		return sdebug_store_sectors;
  }
  
  #define SDEBUG_READCAP_ARR_SZ 8
  static int resp_readcap(struct scsi_cmnd *scp,
  			struct sdebug_dev_info *devip)
  {
  	unsigned char arr[SDEBUG_READCAP_ARR_SZ];
  	unsigned int capac;
  
  	/* following just in case virtual_gb changed */
  	sdebug_capacity = get_sdebug_capacity();
  	memset(arr, 0, SDEBUG_READCAP_ARR_SZ);
  	if (sdebug_capacity < 0xffffffff) {
  		capac = (unsigned int)sdebug_capacity - 1;
  		put_unaligned_be32(capac, arr + 0);
  	} else
  		put_unaligned_be32(0xffffffff, arr + 0);
  	put_unaligned_be16(sdebug_sector_size, arr + 6);
  	return fill_from_dev_buffer(scp, arr, SDEBUG_READCAP_ARR_SZ);
  }
  
  #define SDEBUG_READCAP16_ARR_SZ 32
  static int resp_readcap16(struct scsi_cmnd *scp,
  			  struct sdebug_dev_info *devip)
  {
  	unsigned char *cmd = scp->cmnd;
  	unsigned char arr[SDEBUG_READCAP16_ARR_SZ];
  	int alloc_len;
  
  	alloc_len = get_unaligned_be32(cmd + 10);
  	/* following just in case virtual_gb changed */
  	sdebug_capacity = get_sdebug_capacity();
  	memset(arr, 0, SDEBUG_READCAP16_ARR_SZ);
  	put_unaligned_be64((u64)(sdebug_capacity - 1), arr + 0);
  	put_unaligned_be32(sdebug_sector_size, arr + 8);
  	arr[13] = sdebug_physblk_exp & 0xf;
  	arr[14] = (sdebug_lowest_aligned >> 8) & 0x3f;
  
  	if (scsi_debug_lbp()) {
  		arr[14] |= 0x80; /* LBPME */
  		/* from sbc4r07, this LBPRZ field is 1 bit, but the LBPRZ in
  		 * the LB Provisioning VPD page is 3 bits. Note that lbprz=2
  		 * in the wider field maps to 0 in this field.
  		 */
  		if (sdebug_lbprz & 1)	/* precisely what the draft requires */
  			arr[14] |= 0x40;
  	}
  
  	arr[15] = sdebug_lowest_aligned & 0xff;
  
  	if (have_dif_prot) {
  		arr[12] = (sdebug_dif - 1) << 1; /* P_TYPE */
  		arr[12] |= 1; /* PROT_EN */
  	}
  
  	return fill_from_dev_buffer(scp, arr,
  				    min(alloc_len, SDEBUG_READCAP16_ARR_SZ));
  }
  
  #define SDEBUG_MAX_TGTPGS_ARR_SZ 1412
  
  static int resp_report_tgtpgs(struct scsi_cmnd *scp,
  			      struct sdebug_dev_info *devip)
  {
  	unsigned char *cmd = scp->cmnd;
  	unsigned char *arr;
  	int host_no = devip->sdbg_host->shost->host_no;
  	int n, ret, alen, rlen;
  	int port_group_a, port_group_b, port_a, port_b;
  
  	alen = get_unaligned_be32(cmd + 6);
  	arr = kzalloc(SDEBUG_MAX_TGTPGS_ARR_SZ, GFP_ATOMIC);
  	if (! arr)
  		return DID_REQUEUE << 16;
  	/*
  	 * EVPD page 0x88 states we have two ports, one
  	 * real and a fake port with no device connected.
  	 * So we create two port groups with one port each
  	 * and set the group with port B to unavailable.
  	 */
  	port_a = 0x1; /* relative port A */
  	port_b = 0x2; /* relative port B */
  	port_group_a = (((host_no + 1) & 0x7f) << 8) +
  			(devip->channel & 0x7f);
  	port_group_b = (((host_no + 1) & 0x7f) << 8) +
  			(devip->channel & 0x7f) + 0x80;
  
  	/*
  	 * The asymmetric access state is cycled according to the host_id.
  	 */
  	n = 4;
  	if (sdebug_vpd_use_hostno == 0) {
  		arr[n++] = host_no % 3; /* Asymm access state */
  		arr[n++] = 0x0F; /* claim: all states are supported */
  	} else {
  		arr[n++] = 0x0; /* Active/Optimized path */
  		arr[n++] = 0x01; /* only support active/optimized paths */
  	}
  	put_unaligned_be16(port_group_a, arr + n);
  	n += 2;
  	arr[n++] = 0;    /* Reserved */
  	arr[n++] = 0;    /* Status code */
  	arr[n++] = 0;    /* Vendor unique */
  	arr[n++] = 0x1;  /* One port per group */
  	arr[n++] = 0;    /* Reserved */
  	arr[n++] = 0;    /* Reserved */
  	put_unaligned_be16(port_a, arr + n);
  	n += 2;
  	arr[n++] = 3;    /* Port unavailable */
  	arr[n++] = 0x08; /* claim: only unavailalbe paths are supported */
  	put_unaligned_be16(port_group_b, arr + n);
  	n += 2;
  	arr[n++] = 0;    /* Reserved */
  	arr[n++] = 0;    /* Status code */
  	arr[n++] = 0;    /* Vendor unique */
  	arr[n++] = 0x1;  /* One port per group */
  	arr[n++] = 0;    /* Reserved */
  	arr[n++] = 0;    /* Reserved */
  	put_unaligned_be16(port_b, arr + n);
  	n += 2;
  
  	rlen = n - 4;
  	put_unaligned_be32(rlen, arr + 0);
  
  	/*
  	 * Return the smallest value of either
  	 * - The allocated length
  	 * - The constructed command length
  	 * - The maximum array size
  	 */
  	rlen = min(alen,n);
  	ret = fill_from_dev_buffer(scp, arr,
  				   min(rlen, SDEBUG_MAX_TGTPGS_ARR_SZ));
  	kfree(arr);
  	return ret;
  }
  
  static int resp_rsup_opcodes(struct scsi_cmnd *scp,
  			     struct sdebug_dev_info *devip)
  {
  	bool rctd;
  	u8 reporting_opts, req_opcode, sdeb_i, supp;
  	u16 req_sa, u;
  	u32 alloc_len, a_len;
  	int k, offset, len, errsts, count, bump, na;
  	const struct opcode_info_t *oip;
  	const struct opcode_info_t *r_oip;
  	u8 *arr;
  	u8 *cmd = scp->cmnd;
  
  	rctd = !!(cmd[2] & 0x80);
  	reporting_opts = cmd[2] & 0x7;
  	req_opcode = cmd[3];
  	req_sa = get_unaligned_be16(cmd + 4);
  	alloc_len = get_unaligned_be32(cmd + 6);
  	if (alloc_len < 4 || alloc_len > 0xffff) {
  		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 6, -1);
  		return check_condition_result;
  	}
  	if (alloc_len > 8192)
  		a_len = 8192;
  	else
  		a_len = alloc_len;
  	arr = kzalloc((a_len < 256) ? 320 : a_len + 64, GFP_ATOMIC);
  	if (NULL == arr) {
  		mk_sense_buffer(scp, ILLEGAL_REQUEST, INSUFF_RES_ASC,
  				INSUFF_RES_ASCQ);
  		return check_condition_result;
  	}
  	switch (reporting_opts) {
  	case 0:	/* all commands */
  		/* count number of commands */
  		for (count = 0, oip = opcode_info_arr;
  		     oip->num_attached != 0xff; ++oip) {
  			if (F_INV_OP & oip->flags)
  				continue;
  			count += (oip->num_attached + 1);
  		}
  		bump = rctd ? 20 : 8;
  		put_unaligned_be32(count * bump, arr);
  		for (offset = 4, oip = opcode_info_arr;
  		     oip->num_attached != 0xff && offset < a_len; ++oip) {
  			if (F_INV_OP & oip->flags)
  				continue;
  			na = oip->num_attached;
  			arr[offset] = oip->opcode;
  			put_unaligned_be16(oip->sa, arr + offset + 2);
  			if (rctd)
  				arr[offset + 5] |= 0x2;
  			if (FF_SA & oip->flags)
  				arr[offset + 5] |= 0x1;
  			put_unaligned_be16(oip->len_mask[0], arr + offset + 6);
  			if (rctd)
  				put_unaligned_be16(0xa, arr + offset + 8);
  			r_oip = oip;
  			for (k = 0, oip = oip->arrp; k < na; ++k, ++oip) {
  				if (F_INV_OP & oip->flags)
  					continue;
  				offset += bump;
  				arr[offset] = oip->opcode;
  				put_unaligned_be16(oip->sa, arr + offset + 2);
  				if (rctd)
  					arr[offset + 5] |= 0x2;
  				if (FF_SA & oip->flags)
  					arr[offset + 5] |= 0x1;
  				put_unaligned_be16(oip->len_mask[0],
  						   arr + offset + 6);
  				if (rctd)
  					put_unaligned_be16(0xa,
  							   arr + offset + 8);
  			}
  			oip = r_oip;
  			offset += bump;
  		}
  		break;
  	case 1:	/* one command: opcode only */
  	case 2:	/* one command: opcode plus service action */
  	case 3:	/* one command: if sa==0 then opcode only else opcode+sa */
  		sdeb_i = opcode_ind_arr[req_opcode];
  		oip = &opcode_info_arr[sdeb_i];
  		if (F_INV_OP & oip->flags) {
  			supp = 1;
  			offset = 4;
  		} else {
  			if (1 == reporting_opts) {
  				if (FF_SA & oip->flags) {
  					mk_sense_invalid_fld(scp, SDEB_IN_CDB,
  							     2, 2);
  					kfree(arr);
  					return check_condition_result;
  				}
  				req_sa = 0;
  			} else if (2 == reporting_opts &&
  				   0 == (FF_SA & oip->flags)) {
  				mk_sense_invalid_fld(scp, SDEB_IN_CDB, 4, -1);
  				kfree(arr);	/* point at requested sa */
  				return check_condition_result;
  			}
  			if (0 == (FF_SA & oip->flags) &&
  			    req_opcode == oip->opcode)
  				supp = 3;
  			else if (0 == (FF_SA & oip->flags)) {
  				na = oip->num_attached;
  				for (k = 0, oip = oip->arrp; k < na;
  				     ++k, ++oip) {
  					if (req_opcode == oip->opcode)
  						break;
  				}
  				supp = (k >= na) ? 1 : 3;
  			} else if (req_sa != oip->sa) {
  				na = oip->num_attached;
  				for (k = 0, oip = oip->arrp; k < na;
  				     ++k, ++oip) {
  					if (req_sa == oip->sa)
  						break;
  				}
  				supp = (k >= na) ? 1 : 3;
  			} else
  				supp = 3;
  			if (3 == supp) {
  				u = oip->len_mask[0];
  				put_unaligned_be16(u, arr + 2);
  				arr[4] = oip->opcode;
  				for (k = 1; k < u; ++k)
  					arr[4 + k] = (k < 16) ?
  						 oip->len_mask[k] : 0xff;
  				offset = 4 + u;
  			} else
  				offset = 4;
  		}
  		arr[1] = (rctd ? 0x80 : 0) | supp;
  		if (rctd) {
  			put_unaligned_be16(0xa, arr + offset);
  			offset += 12;
  		}
  		break;
  	default:
  		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 2, 2);
  		kfree(arr);
  		return check_condition_result;
  	}
  	offset = (offset < a_len) ? offset : a_len;
  	len = (offset < alloc_len) ? offset : alloc_len;
  	errsts = fill_from_dev_buffer(scp, arr, len);
  	kfree(arr);
  	return errsts;
  }
  
  static int resp_rsup_tmfs(struct scsi_cmnd *scp,
  			  struct sdebug_dev_info *devip)
  {
  	bool repd;
  	u32 alloc_len, len;
  	u8 arr[16];
  	u8 *cmd = scp->cmnd;
  
  	memset(arr, 0, sizeof(arr));
  	repd = !!(cmd[2] & 0x80);
  	alloc_len = get_unaligned_be32(cmd + 6);
  	if (alloc_len < 4) {
  		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 6, -1);
  		return check_condition_result;
  	}
  	arr[0] = 0xc8;		/* ATS | ATSS | LURS */
  	arr[1] = 0x1;		/* ITNRS */
  	if (repd) {
  		arr[3] = 0xc;
  		len = 16;
  	} else
  		len = 4;
  
  	len = (len < alloc_len) ? len : alloc_len;
  	return fill_from_dev_buffer(scp, arr, len);
  }
  
  /* <<Following mode page info copied from ST318451LW>> */
  
  static int resp_err_recov_pg(unsigned char *p, int pcontrol, int target)
  {	/* Read-Write Error Recovery page for mode_sense */
  	unsigned char err_recov_pg[] = {0x1, 0xa, 0xc0, 11, 240, 0, 0, 0,
  					5, 0, 0xff, 0xff};
  
  	memcpy(p, err_recov_pg, sizeof(err_recov_pg));
  	if (1 == pcontrol)
  		memset(p + 2, 0, sizeof(err_recov_pg) - 2);
  	return sizeof(err_recov_pg);
  }
  
  static int resp_disconnect_pg(unsigned char *p, int pcontrol, int target)
  { 	/* Disconnect-Reconnect page for mode_sense */
  	unsigned char disconnect_pg[] = {0x2, 0xe, 128, 128, 0, 10, 0, 0,
  					 0, 0, 0, 0, 0, 0, 0, 0};
  
  	memcpy(p, disconnect_pg, sizeof(disconnect_pg));
  	if (1 == pcontrol)
  		memset(p + 2, 0, sizeof(disconnect_pg) - 2);
  	return sizeof(disconnect_pg);
  }
  
  static int resp_format_pg(unsigned char *p, int pcontrol, int target)
  {       /* Format device page for mode_sense */
  	unsigned char format_pg[] = {0x3, 0x16, 0, 0, 0, 0, 0, 0,
  				     0, 0, 0, 0, 0, 0, 0, 0,
  				     0, 0, 0, 0, 0x40, 0, 0, 0};
  
  	memcpy(p, format_pg, sizeof(format_pg));
  	put_unaligned_be16(sdebug_sectors_per, p + 10);
  	put_unaligned_be16(sdebug_sector_size, p + 12);
  	if (sdebug_removable)
  		p[20] |= 0x20; /* should agree with INQUIRY */
  	if (1 == pcontrol)
  		memset(p + 2, 0, sizeof(format_pg) - 2);
  	return sizeof(format_pg);
  }
  
  static unsigned char caching_pg[] = {0x8, 18, 0x14, 0, 0xff, 0xff, 0, 0,
  				     0xff, 0xff, 0xff, 0xff, 0x80, 0x14, 0, 0,
  				     0, 0, 0, 0};
  
  static int resp_caching_pg(unsigned char *p, int pcontrol, int target)
  { 	/* Caching page for mode_sense */
  	unsigned char ch_caching_pg[] = {/* 0x8, 18, */ 0x4, 0, 0, 0, 0, 0,
  		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
  	unsigned char d_caching_pg[] = {0x8, 18, 0x14, 0, 0xff, 0xff, 0, 0,
  		0xff, 0xff, 0xff, 0xff, 0x80, 0x14, 0, 0,     0, 0, 0, 0};
  
  	if (SDEBUG_OPT_N_WCE & sdebug_opts)
  		caching_pg[2] &= ~0x4;	/* set WCE=0 (default WCE=1) */
  	memcpy(p, caching_pg, sizeof(caching_pg));
  	if (1 == pcontrol)
  		memcpy(p + 2, ch_caching_pg, sizeof(ch_caching_pg));
  	else if (2 == pcontrol)
  		memcpy(p, d_caching_pg, sizeof(d_caching_pg));
  	return sizeof(caching_pg);
  }
  
  static unsigned char ctrl_m_pg[] = {0xa, 10, 2, 0, 0, 0, 0, 0,
  				    0, 0, 0x2, 0x4b};
  
  static int resp_ctrl_m_pg(unsigned char *p, int pcontrol, int target)
  { 	/* Control mode page for mode_sense */
  	unsigned char ch_ctrl_m_pg[] = {/* 0xa, 10, */ 0x6, 0, 0, 0, 0, 0,
  					0, 0, 0, 0};
  	unsigned char d_ctrl_m_pg[] = {0xa, 10, 2, 0, 0, 0, 0, 0,
  				     0, 0, 0x2, 0x4b};
  
  	if (sdebug_dsense)
  		ctrl_m_pg[2] |= 0x4;
  	else
  		ctrl_m_pg[2] &= ~0x4;
  
  	if (sdebug_ato)
  		ctrl_m_pg[5] |= 0x80; /* ATO=1 */
  
  	memcpy(p, ctrl_m_pg, sizeof(ctrl_m_pg));
  	if (1 == pcontrol)
  		memcpy(p + 2, ch_ctrl_m_pg, sizeof(ch_ctrl_m_pg));
  	else if (2 == pcontrol)
  		memcpy(p, d_ctrl_m_pg, sizeof(d_ctrl_m_pg));
  	return sizeof(ctrl_m_pg);
  }
  
  
  static int resp_iec_m_pg(unsigned char *p, int pcontrol, int target)
  {	/* Informational Exceptions control mode page for mode_sense */
  	unsigned char ch_iec_m_pg[] = {/* 0x1c, 0xa, */ 0x4, 0xf, 0, 0, 0, 0,
  				       0, 0, 0x0, 0x0};
  	unsigned char d_iec_m_pg[] = {0x1c, 0xa, 0x08, 0, 0, 0, 0, 0,
  				      0, 0, 0x0, 0x0};
  
  	memcpy(p, iec_m_pg, sizeof(iec_m_pg));
  	if (1 == pcontrol)
  		memcpy(p + 2, ch_iec_m_pg, sizeof(ch_iec_m_pg));
  	else if (2 == pcontrol)
  		memcpy(p, d_iec_m_pg, sizeof(d_iec_m_pg));
  	return sizeof(iec_m_pg);
  }
  
  static int resp_sas_sf_m_pg(unsigned char *p, int pcontrol, int target)
  {	/* SAS SSP mode page - short format for mode_sense */
  	unsigned char sas_sf_m_pg[] = {0x19, 0x6,
  		0x6, 0x0, 0x7, 0xd0, 0x0, 0x0};
  
  	memcpy(p, sas_sf_m_pg, sizeof(sas_sf_m_pg));
  	if (1 == pcontrol)
  		memset(p + 2, 0, sizeof(sas_sf_m_pg) - 2);
  	return sizeof(sas_sf_m_pg);
  }
  
  
  static int resp_sas_pcd_m_spg(unsigned char *p, int pcontrol, int target,
  			      int target_dev_id)
  {	/* SAS phy control and discover mode page for mode_sense */
  	unsigned char sas_pcd_m_pg[] = {0x59, 0x1, 0, 0x64, 0, 0x6, 0, 2,
  		    0, 0, 0, 0, 0x10, 0x9, 0x8, 0x0,
  		    0, 0, 0, 0, 0, 0, 0, 0,	/* insert SAS addr */
  		    0, 0, 0, 0, 0, 0, 0, 0,	/* insert SAS addr */
  		    0x2, 0, 0, 0, 0, 0, 0, 0,
  		    0x88, 0x99, 0, 0, 0, 0, 0, 0,
  		    0, 0, 0, 0, 0, 0, 0, 0,
  		    0, 1, 0, 0, 0x10, 0x9, 0x8, 0x0,
  		    0, 0, 0, 0, 0, 0, 0, 0,	/* insert SAS addr */
  		    0, 0, 0, 0, 0, 0, 0, 0,	/* insert SAS addr */
  		    0x3, 0, 0, 0, 0, 0, 0, 0,
  		    0x88, 0x99, 0, 0, 0, 0, 0, 0,
  		    0, 0, 0, 0, 0, 0, 0, 0,
  		};
  	int port_a, port_b;
  
  	put_unaligned_be64(naa3_comp_a, sas_pcd_m_pg + 16);
  	put_unaligned_be64(naa3_comp_c + 1, sas_pcd_m_pg + 24);
  	put_unaligned_be64(naa3_comp_a, sas_pcd_m_pg + 64);
  	put_unaligned_be64(naa3_comp_c + 1, sas_pcd_m_pg + 72);
  	port_a = target_dev_id + 1;
  	port_b = port_a + 1;
  	memcpy(p, sas_pcd_m_pg, sizeof(sas_pcd_m_pg));
  	put_unaligned_be32(port_a, p + 20);
  	put_unaligned_be32(port_b, p + 48 + 20);
  	if (1 == pcontrol)
  		memset(p + 4, 0, sizeof(sas_pcd_m_pg) - 4);
  	return sizeof(sas_pcd_m_pg);
  }
  
  static int resp_sas_sha_m_spg(unsigned char *p, int pcontrol)
  {	/* SAS SSP shared protocol specific port mode subpage */
  	unsigned char sas_sha_m_pg[] = {0x59, 0x2, 0, 0xc, 0, 0x6, 0x10, 0,
  		    0, 0, 0, 0, 0, 0, 0, 0,
  		};
  
  	memcpy(p, sas_sha_m_pg, sizeof(sas_sha_m_pg));
  	if (1 == pcontrol)
  		memset(p + 4, 0, sizeof(sas_sha_m_pg) - 4);
  	return sizeof(sas_sha_m_pg);
  }
  
  #define SDEBUG_MAX_MSENSE_SZ 256
  
  static int resp_mode_sense(struct scsi_cmnd *scp,
  			   struct sdebug_dev_info *devip)
  {
  	int pcontrol, pcode, subpcode, bd_len;
  	unsigned char dev_spec;
  	int alloc_len, offset, len, target_dev_id;
  	int target = scp->device->id;
  	unsigned char *ap;
  	unsigned char arr[SDEBUG_MAX_MSENSE_SZ];
  	unsigned char *cmd = scp->cmnd;
  	bool dbd, llbaa, msense_6, is_disk, bad_pcode;
  
  	dbd = !!(cmd[1] & 0x8);		/* disable block descriptors */
  	pcontrol = (cmd[2] & 0xc0) >> 6;
  	pcode = cmd[2] & 0x3f;
  	subpcode = cmd[3];
  	msense_6 = (MODE_SENSE == cmd[0]);
  	llbaa = msense_6 ? false : !!(cmd[1] & 0x10);
  	is_disk = (sdebug_ptype == TYPE_DISK);
  	if (is_disk && !dbd)
  		bd_len = llbaa ? 16 : 8;
  	else
  		bd_len = 0;
  	alloc_len = msense_6 ? cmd[4] : get_unaligned_be16(cmd + 7);
  	memset(arr, 0, SDEBUG_MAX_MSENSE_SZ);
  	if (0x3 == pcontrol) {  /* Saving values not supported */
  		mk_sense_buffer(scp, ILLEGAL_REQUEST, SAVING_PARAMS_UNSUP, 0);
  		return check_condition_result;
  	}
  	target_dev_id = ((devip->sdbg_host->shost->host_no + 1) * 2000) +
  			(devip->target * 1000) - 3;
  	/* for disks set DPOFUA bit and clear write protect (WP) bit */
  	if (is_disk) {
  		dev_spec = 0x10;	/* =0x90 if WP=1 implies read-only */
  		if (sdebug_wp)
  			dev_spec |= 0x80;
  	} else
  		dev_spec = 0x0;
  	if (msense_6) {
  		arr[2] = dev_spec;
  		arr[3] = bd_len;
  		offset = 4;
  	} else {
  		arr[3] = dev_spec;
  		if (16 == bd_len)
  			arr[4] = 0x1;	/* set LONGLBA bit */
  		arr[7] = bd_len;	/* assume 255 or less */
  		offset = 8;
  	}
  	ap = arr + offset;
  	if ((bd_len > 0) && (!sdebug_capacity))
  		sdebug_capacity = get_sdebug_capacity();
  
  	if (8 == bd_len) {
  		if (sdebug_capacity > 0xfffffffe)
  			put_unaligned_be32(0xffffffff, ap + 0);
  		else
  			put_unaligned_be32(sdebug_capacity, ap + 0);
  		put_unaligned_be16(sdebug_sector_size, ap + 6);
  		offset += bd_len;
  		ap = arr + offset;
  	} else if (16 == bd_len) {
  		put_unaligned_be64((u64)sdebug_capacity, ap + 0);
  		put_unaligned_be32(sdebug_sector_size, ap + 12);
  		offset += bd_len;
  		ap = arr + offset;
  	}
  
  	if ((subpcode > 0x0) && (subpcode < 0xff) && (0x19 != pcode)) {
  		/* TODO: Control Extension page */
  		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 3, -1);
  		return check_condition_result;
  	}
  	bad_pcode = false;
  
  	switch (pcode) {
  	case 0x1:	/* Read-Write error recovery page, direct access */
  		len = resp_err_recov_pg(ap, pcontrol, target);
  		offset += len;
  		break;
  	case 0x2:	/* Disconnect-Reconnect page, all devices */
  		len = resp_disconnect_pg(ap, pcontrol, target);
  		offset += len;
  		break;
  	case 0x3:       /* Format device page, direct access */
  		if (is_disk) {
  			len = resp_format_pg(ap, pcontrol, target);
  			offset += len;
  		} else
  			bad_pcode = true;
  		break;
  	case 0x8:	/* Caching page, direct access */
  		if (is_disk) {
  			len = resp_caching_pg(ap, pcontrol, target);
  			offset += len;
  		} else
  			bad_pcode = true;
  		break;
  	case 0xa:	/* Control Mode page, all devices */
  		len = resp_ctrl_m_pg(ap, pcontrol, target);
  		offset += len;
  		break;
  	case 0x19:	/* if spc==1 then sas phy, control+discover */
  		if ((subpcode > 0x2) && (subpcode < 0xff)) {
  			mk_sense_invalid_fld(scp, SDEB_IN_CDB, 3, -1);
  			return check_condition_result;
  		}
  		len = 0;
  		if ((0x0 == subpcode) || (0xff == subpcode))
  			len += resp_sas_sf_m_pg(ap + len, pcontrol, target);
  		if ((0x1 == subpcode) || (0xff == subpcode))
  			len += resp_sas_pcd_m_spg(ap + len, pcontrol, target,
  						  target_dev_id);
  		if ((0x2 == subpcode) || (0xff == subpcode))
  			len += resp_sas_sha_m_spg(ap + len, pcontrol);
  		offset += len;
  		break;
  	case 0x1c:	/* Informational Exceptions Mode page, all devices */
  		len = resp_iec_m_pg(ap, pcontrol, target);
  		offset += len;
  		break;
  	case 0x3f:	/* Read all Mode pages */
  		if ((0 == subpcode) || (0xff == subpcode)) {
  			len = resp_err_recov_pg(ap, pcontrol, target);
  			len += resp_disconnect_pg(ap + len, pcontrol, target);
  			if (is_disk) {
  				len += resp_format_pg(ap + len, pcontrol,
  						      target);
  				len += resp_caching_pg(ap + len, pcontrol,
  						       target);
  			}
  			len += resp_ctrl_m_pg(ap + len, pcontrol, target);
  			len += resp_sas_sf_m_pg(ap + len, pcontrol, target);
  			if (0xff == subpcode) {
  				len += resp_sas_pcd_m_spg(ap + len, pcontrol,
  						  target, target_dev_id);
  				len += resp_sas_sha_m_spg(ap + len, pcontrol);
  			}
  			len += resp_iec_m_pg(ap + len, pcontrol, target);
  			offset += len;
  		} else {
  			mk_sense_invalid_fld(scp, SDEB_IN_CDB, 3, -1);
  			return check_condition_result;
  		}
  		break;
  	default:
  		bad_pcode = true;
  		break;
  	}
  	if (bad_pcode) {
  		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 2, 5);
  		return check_condition_result;
  	}
  	if (msense_6)
  		arr[0] = offset - 1;
  	else
  		put_unaligned_be16((offset - 2), arr + 0);
  	return fill_from_dev_buffer(scp, arr, min(alloc_len, offset));
  }
  
  #define SDEBUG_MAX_MSELECT_SZ 512
  
  static int resp_mode_select(struct scsi_cmnd *scp,
  			    struct sdebug_dev_info *devip)
  {
  	int pf, sp, ps, md_len, bd_len, off, spf, pg_len;
  	int param_len, res, mpage;
  	unsigned char arr[SDEBUG_MAX_MSELECT_SZ];
  	unsigned char *cmd = scp->cmnd;
  	int mselect6 = (MODE_SELECT == cmd[0]);
  
  	memset(arr, 0, sizeof(arr));
  	pf = cmd[1] & 0x10;
  	sp = cmd[1] & 0x1;
  	param_len = mselect6 ? cmd[4] : get_unaligned_be16(cmd + 7);
  	if ((0 == pf) || sp || (param_len > SDEBUG_MAX_MSELECT_SZ)) {
  		mk_sense_invalid_fld(scp, SDEB_IN_CDB, mselect6 ? 4 : 7, -1);
  		return check_condition_result;
  	}
  	res = fetch_to_dev_buffer(scp, arr, param_len);
  	if (-1 == res)
  		return DID_ERROR << 16;
  	else if (sdebug_verbose && (res < param_len))
  		sdev_printk(KERN_INFO, scp->device,
  			    "%s: cdb indicated=%d, IO sent=%d bytes\n",
  			    __func__, param_len, res);
  	md_len = mselect6 ? (arr[0] + 1) : (get_unaligned_be16(arr + 0) + 2);
  	bd_len = mselect6 ? arr[3] : get_unaligned_be16(arr + 6);
  	if (md_len > 2) {
  		mk_sense_invalid_fld(scp, SDEB_IN_DATA, 0, -1);
  		return check_condition_result;
  	}
  	off = bd_len + (mselect6 ? 4 : 8);
  	mpage = arr[off] & 0x3f;
  	ps = !!(arr[off] & 0x80);
  	if (ps) {
  		mk_sense_invalid_fld(scp, SDEB_IN_DATA, off, 7);
  		return check_condition_result;
  	}
  	spf = !!(arr[off] & 0x40);
  	pg_len = spf ? (get_unaligned_be16(arr + off + 2) + 4) :
  		       (arr[off + 1] + 2);
  	if ((pg_len + off) > param_len) {
  		mk_sense_buffer(scp, ILLEGAL_REQUEST,
  				PARAMETER_LIST_LENGTH_ERR, 0);
  		return check_condition_result;
  	}
  	switch (mpage) {
  	case 0x8:      /* Caching Mode page */
  		if (caching_pg[1] == arr[off + 1]) {
  			memcpy(caching_pg + 2, arr + off + 2,
  			       sizeof(caching_pg) - 2);
  			goto set_mode_changed_ua;
  		}
  		break;
  	case 0xa:      /* Control Mode page */
  		if (ctrl_m_pg[1] == arr[off + 1]) {
  			memcpy(ctrl_m_pg + 2, arr + off + 2,
  			       sizeof(ctrl_m_pg) - 2);
  			if (ctrl_m_pg[4] & 0x8)
  				sdebug_wp = true;
  			else
  				sdebug_wp = false;
  			sdebug_dsense = !!(ctrl_m_pg[2] & 0x4);
  			goto set_mode_changed_ua;
  		}
  		break;
  	case 0x1c:      /* Informational Exceptions Mode page */
  		if (iec_m_pg[1] == arr[off + 1]) {
  			memcpy(iec_m_pg + 2, arr + off + 2,
  			       sizeof(iec_m_pg) - 2);
  			goto set_mode_changed_ua;
  		}
  		break;
  	default:
  		break;
  	}
  	mk_sense_invalid_fld(scp, SDEB_IN_DATA, off, 5);
  	return check_condition_result;
  set_mode_changed_ua:
  	set_bit(SDEBUG_UA_MODE_CHANGED, devip->uas_bm);
  	return 0;
  }
  
  static int resp_temp_l_pg(unsigned char *arr)
  {
  	unsigned char temp_l_pg[] = {0x0, 0x0, 0x3, 0x2, 0x0, 38,
  				     0x0, 0x1, 0x3, 0x2, 0x0, 65,
  		};
  
  	memcpy(arr, temp_l_pg, sizeof(temp_l_pg));
  	return sizeof(temp_l_pg);
  }
  
  static int resp_ie_l_pg(unsigned char *arr)
  {
  	unsigned char ie_l_pg[] = {0x0, 0x0, 0x3, 0x3, 0x0, 0x0, 38,
  		};
  
  	memcpy(arr, ie_l_pg, sizeof(ie_l_pg));
  	if (iec_m_pg[2] & 0x4) {	/* TEST bit set */
  		arr[4] = THRESHOLD_EXCEEDED;
  		arr[5] = 0xff;
  	}
  	return sizeof(ie_l_pg);
  }
  
  #define SDEBUG_MAX_LSENSE_SZ 512
  
  static int resp_log_sense(struct scsi_cmnd *scp,
  			  struct sdebug_dev_info *devip)
  {
  	int ppc, sp, pcode, subpcode, alloc_len, len, n;
  	unsigned char arr[SDEBUG_MAX_LSENSE_SZ];
  	unsigned char *cmd = scp->cmnd;
  
  	memset(arr, 0, sizeof(arr));
  	ppc = cmd[1] & 0x2;
  	sp = cmd[1] & 0x1;
  	if (ppc || sp) {
  		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 1, ppc ? 1 : 0);
  		return check_condition_result;
  	}
  	pcode = cmd[2] & 0x3f;
  	subpcode = cmd[3] & 0xff;
  	alloc_len = get_unaligned_be16(cmd + 7);
  	arr[0] = pcode;
  	if (0 == subpcode) {
  		switch (pcode) {
  		case 0x0:	/* Supported log pages log page */
  			n = 4;
  			arr[n++] = 0x0;		/* this page */
  			arr[n++] = 0xd;		/* Temperature */
  			arr[n++] = 0x2f;	/* Informational exceptions */
  			arr[3] = n - 4;
  			break;
  		case 0xd:	/* Temperature log page */
  			arr[3] = resp_temp_l_pg(arr + 4);
  			break;
  		case 0x2f:	/* Informational exceptions log page */
  			arr[3] = resp_ie_l_pg(arr + 4);
  			break;
  		default:
  			mk_sense_invalid_fld(scp, SDEB_IN_CDB, 2, 5);
  			return check_condition_result;
  		}
  	} else if (0xff == subpcode) {
  		arr[0] |= 0x40;
  		arr[1] = subpcode;
  		switch (pcode) {
  		case 0x0:	/* Supported log pages and subpages log page */
  			n = 4;
  			arr[n++] = 0x0;
  			arr[n++] = 0x0;		/* 0,0 page */
  			arr[n++] = 0x0;
  			arr[n++] = 0xff;	/* this page */
  			arr[n++] = 0xd;
  			arr[n++] = 0x0;		/* Temperature */
  			arr[n++] = 0x2f;
  			arr[n++] = 0x0;	/* Informational exceptions */
  			arr[3] = n - 4;
  			break;
  		case 0xd:	/* Temperature subpages */
  			n = 4;
  			arr[n++] = 0xd;
  			arr[n++] = 0x0;		/* Temperature */
  			arr[3] = n - 4;
  			break;
  		case 0x2f:	/* Informational exceptions subpages */
  			n = 4;
  			arr[n++] = 0x2f;
  			arr[n++] = 0x0;		/* Informational exceptions */
  			arr[3] = n - 4;
  			break;
  		default:
  			mk_sense_invalid_fld(scp, SDEB_IN_CDB, 2, 5);
  			return check_condition_result;
  		}
  	} else {
  		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 3, -1);
  		return check_condition_result;
  	}
  	len = min(get_unaligned_be16(arr + 2) + 4, alloc_len);
  	return fill_from_dev_buffer(scp, arr,
  		    min(len, SDEBUG_MAX_INQ_ARR_SZ));
  }
  
  static inline int check_device_access_params(struct scsi_cmnd *scp,
  	unsigned long long lba, unsigned int num, bool write)
  {
  	if (lba + num > sdebug_capacity) {
  		mk_sense_buffer(scp, ILLEGAL_REQUEST, LBA_OUT_OF_RANGE, 0);
  		return check_condition_result;
  	}
  	/* transfer length excessive (tie in to block limits VPD page) */
  	if (num > sdebug_store_sectors) {
  		/* needs work to find which cdb byte 'num' comes from */
  		mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0);
  		return check_condition_result;
  	}
  	if (write && unlikely(sdebug_wp)) {
  		mk_sense_buffer(scp, DATA_PROTECT, WRITE_PROTECTED, 0x2);
  		return check_condition_result;
  	}
  	return 0;
  }
  
  /* Returns number of bytes copied or -1 if error. */
  static int do_device_access(struct scsi_cmnd *scmd, u32 sg_skip, u64 lba,
  			    u32 num, bool do_write)
  {
  	int ret;
  	u64 block, rest = 0;
  	struct scsi_data_buffer *sdb = &scmd->sdb;
  	enum dma_data_direction dir;
  
  	if (do_write) {
  		dir = DMA_TO_DEVICE;
  		write_since_sync = true;
  	} else {
  		dir = DMA_FROM_DEVICE;
  	}
  
  	if (!sdb->length)
  		return 0;
  	if (scmd->sc_data_direction != dir)
  		return -1;
  
  	block = do_div(lba, sdebug_store_sectors);
  	if (block + num > sdebug_store_sectors)
  		rest = block + num - sdebug_store_sectors;
  
  	ret = sg_copy_buffer(sdb->table.sgl, sdb->table.nents,
  		   fake_storep + (block * sdebug_sector_size),
  		   (num - rest) * sdebug_sector_size, sg_skip, do_write);
  	if (ret != (num - rest) * sdebug_sector_size)
  		return ret;
  
  	if (rest) {
  		ret += sg_copy_buffer(sdb->table.sgl, sdb->table.nents,
  			    fake_storep, rest * sdebug_sector_size,
  			    sg_skip + ((num - rest) * sdebug_sector_size),
  			    do_write);
  	}
  
  	return ret;
  }
  
  /* If lba2fake_store(lba,num) compares equal to arr(num), then copy top half of
   * arr into lba2fake_store(lba,num) and return true. If comparison fails then
   * return false. */
  static bool comp_write_worker(u64 lba, u32 num, const u8 *arr)
  {
  	bool res;
  	u64 block, rest = 0;
  	u32 store_blks = sdebug_store_sectors;
  	u32 lb_size = sdebug_sector_size;
  
  	block = do_div(lba, store_blks);
  	if (block + num > store_blks)
  		rest = block + num - store_blks;
  
  	res = !memcmp(fake_storep + (block * lb_size), arr,
  		      (num - rest) * lb_size);
  	if (!res)
  		return res;
  	if (rest)
  		res = memcmp(fake_storep, arr + ((num - rest) * lb_size),
  			     rest * lb_size);
  	if (!res)
  		return res;
  	arr += num * lb_size;
  	memcpy(fake_storep + (block * lb_size), arr, (num - rest) * lb_size);
  	if (rest)
  		memcpy(fake_storep, arr + ((num - rest) * lb_size),
  		       rest * lb_size);
  	return res;
  }
  
  static __be16 dif_compute_csum(const void *buf, int len)
  {
  	__be16 csum;
  
  	if (sdebug_guard)
  		csum = (__force __be16)ip_compute_csum(buf, len);
  	else
  		csum = cpu_to_be16(crc_t10dif(buf, len));
  
  	return csum;
  }
  
  static int dif_verify(struct t10_pi_tuple *sdt, const void *data,
  		      sector_t sector, u32 ei_lba)
  {
  	__be16 csum = dif_compute_csum(data, sdebug_sector_size);
  
  	if (sdt->guard_tag != csum) {
  		pr_err("GUARD check failed on sector %lu rcvd 0x%04x, data 0x%04x\n",
  			(unsigned long)sector,
  			be16_to_cpu(sdt->guard_tag),
  			be16_to_cpu(csum));
  		return 0x01;
  	}
  	if (sdebug_dif == T10_PI_TYPE1_PROTECTION &&
  	    be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
  		pr_err("REF check failed on sector %lu\n",
  			(unsigned long)sector);
  		return 0x03;
  	}
  	if (sdebug_dif == T10_PI_TYPE2_PROTECTION &&
  	    be32_to_cpu(sdt->ref_tag) != ei_lba) {
  		pr_err("REF check failed on sector %lu\n",
  			(unsigned long)sector);
  		return 0x03;
  	}
  	return 0;
  }
  
  static void dif_copy_prot(struct scsi_cmnd *SCpnt, sector_t sector,
  			  unsigned int sectors, bool read)
  {
  	size_t resid;
  	void *paddr;
  	const void *dif_store_end = dif_storep + sdebug_store_sectors;
  	struct sg_mapping_iter miter;
  
  	/* Bytes of protection data to copy into sgl */
  	resid = sectors * sizeof(*dif_storep);
  
  	sg_miter_start(&miter, scsi_prot_sglist(SCpnt),
  			scsi_prot_sg_count(SCpnt), SG_MITER_ATOMIC |
  			(read ? SG_MITER_TO_SG : SG_MITER_FROM_SG));
  
  	while (sg_miter_next(&miter) && resid > 0) {
  		size_t len = min(miter.length, resid);
  		void *start = dif_store(sector);
  		size_t rest = 0;
  
  		if (dif_store_end < start + len)
  			rest = start + len - dif_store_end;
  
  		paddr = miter.addr;
  
  		if (read)
  			memcpy(paddr, start, len - rest);
  		else
  			memcpy(start, paddr, len - rest);
  
  		if (rest) {
  			if (read)
  				memcpy(paddr + len - rest, dif_storep, rest);
  			else
  				memcpy(dif_storep, paddr + len - rest, rest);
  		}
  
  		sector += len / sizeof(*dif_storep);
  		resid -= len;
  	}
  	sg_miter_stop(&miter);
  }
  
  static int prot_verify_read(struct scsi_cmnd *SCpnt, sector_t start_sec,
  			    unsigned int sectors, u32 ei_lba)
  {
  	unsigned int i;
  	struct t10_pi_tuple *sdt;
  	sector_t sector;
  
  	for (i = 0; i < sectors; i++, ei_lba++) {
  		int ret;
  
  		sector = start_sec + i;
  		sdt = dif_store(sector);
  
  		if (sdt->app_tag == cpu_to_be16(0xffff))
  			continue;
  
  		ret = dif_verify(sdt, lba2fake_store(sector), sector, ei_lba);
  		if (ret) {
  			dif_errors++;
  			return ret;
  		}
  	}
  
  	dif_copy_prot(SCpnt, start_sec, sectors, true);
  	dix_reads++;
  
  	return 0;
  }
  
  static int resp_read_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
  {
  	u8 *cmd = scp->cmnd;
  	struct sdebug_queued_cmd *sqcp;
  	u64 lba;
  	u32 num;
  	u32 ei_lba;
  	unsigned long iflags;
  	int ret;
  	bool check_prot;
  
  	switch (cmd[0]) {
  	case READ_16:
  		ei_lba = 0;
  		lba = get_unaligned_be64(cmd + 2);
  		num = get_unaligned_be32(cmd + 10);
  		check_prot = true;
  		break;
  	case READ_10:
  		ei_lba = 0;
  		lba = get_unaligned_be32(cmd + 2);
  		num = get_unaligned_be16(cmd + 7);
  		check_prot = true;
  		break;
  	case READ_6:
  		ei_lba = 0;
  		lba = (u32)cmd[3] | (u32)cmd[2] << 8 |
  		      (u32)(cmd[1] & 0x1f) << 16;
  		num = (0 == cmd[4]) ? 256 : cmd[4];
  		check_prot = true;
  		break;
  	case READ_12:
  		ei_lba = 0;
  		lba = get_unaligned_be32(cmd + 2);
  		num = get_unaligned_be32(cmd + 6);
  		check_prot = true;
  		break;
  	case XDWRITEREAD_10:
  		ei_lba = 0;
  		lba = get_unaligned_be32(cmd + 2);
  		num = get_unaligned_be16(cmd + 7);
  		check_prot = false;
  		break;
  	default:	/* assume READ(32) */
  		lba = get_unaligned_be64(cmd + 12);
  		ei_lba = get_unaligned_be32(cmd + 20);
  		num = get_unaligned_be32(cmd + 28);
  		check_prot = false;
  		break;
  	}
  	if (unlikely(have_dif_prot && check_prot)) {
  		if (sdebug_dif == T10_PI_TYPE2_PROTECTION &&
  		    (cmd[1] & 0xe0)) {
  			mk_sense_invalid_opcode(scp);
  			return check_condition_result;
  		}
  		if ((sdebug_dif == T10_PI_TYPE1_PROTECTION ||
  		     sdebug_dif == T10_PI_TYPE3_PROTECTION) &&
  		    (cmd[1] & 0xe0) == 0)
  			sdev_printk(KERN_ERR, scp->device, "Unprotected RD "
  				    "to DIF device\n");
  	}
  	if (unlikely(sdebug_any_injecting_opt)) {
  		sqcp = (struct sdebug_queued_cmd *)scp->host_scribble;
  
  		if (sqcp) {
  			if (sqcp->inj_short)
  				num /= 2;
  		}
  	} else
  		sqcp = NULL;
  
  	ret = check_device_access_params(scp, lba, num, false);
  	if (ret)
  		return ret;
  	if (unlikely((SDEBUG_OPT_MEDIUM_ERR & sdebug_opts) &&
  		     (lba <= (sdebug_medium_error_start + sdebug_medium_error_count - 1)) &&
  		     ((lba + num) > sdebug_medium_error_start))) {
  		/* claim unrecoverable read error */
  		mk_sense_buffer(scp, MEDIUM_ERROR, UNRECOVERED_READ_ERR, 0);
  		/* set info field and valid bit for fixed descriptor */
  		if (0x70 == (scp->sense_buffer[0] & 0x7f)) {
  			scp->sense_buffer[0] |= 0x80;	/* Valid bit */
  			ret = (lba < OPT_MEDIUM_ERR_ADDR)
  			      ? OPT_MEDIUM_ERR_ADDR : (int)lba;
  			put_unaligned_be32(ret, scp->sense_buffer + 3);
  		}
  		scsi_set_resid(scp, scsi_bufflen(scp));
  		return check_condition_result;
  	}
  
  	read_lock_irqsave(&atomic_rw, iflags);
  
  	/* DIX + T10 DIF */
  	if (unlikely(sdebug_dix && scsi_prot_sg_count(scp))) {
  		int prot_ret = prot_verify_read(scp, lba, num, ei_lba);
  
  		if (prot_ret) {
  			read_unlock_irqrestore(&atomic_rw, iflags);
  			mk_sense_buffer(scp, ABORTED_COMMAND, 0x10, prot_ret);
  			return illegal_condition_result;
  		}
  	}
  
  	ret = do_device_access(scp, 0, lba, num, false);
  	read_unlock_irqrestore(&atomic_rw, iflags);
  	if (unlikely(ret == -1))
  		return DID_ERROR << 16;
  
  	scsi_set_resid(scp, scsi_bufflen(scp) - ret);
  
  	if (unlikely(sqcp)) {
  		if (sqcp->inj_recovered) {
  			mk_sense_buffer(scp, RECOVERED_ERROR,
  					THRESHOLD_EXCEEDED, 0);
  			return check_condition_result;
  		} else if (sqcp->inj_transport) {
  			mk_sense_buffer(scp, ABORTED_COMMAND,
  					TRANSPORT_PROBLEM, ACK_NAK_TO);
  			return check_condition_result;
  		} else if (sqcp->inj_dif) {
  			/* Logical block guard check failed */
  			mk_sense_buffer(scp, ABORTED_COMMAND, 0x10, 1);
  			return illegal_condition_result;
  		} else if (sqcp->inj_dix) {
  			mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10, 1);
  			return illegal_condition_result;
  		}
  	}
  	return 0;
  }
  
  static void dump_sector(unsigned char *buf, int len)
  {
  	int i, j, n;
  
  	pr_err(">>> Sector Dump <<<\n");
  	for (i = 0 ; i < len ; i += 16) {
  		char b[128];
  
  		for (j = 0, n = 0; j < 16; j++) {
  			unsigned char c = buf[i+j];
  
  			if (c >= 0x20 && c < 0x7e)
  				n += scnprintf(b + n, sizeof(b) - n,
  					       " %c ", buf[i+j]);
  			else
  				n += scnprintf(b + n, sizeof(b) - n,
  					       "%02x ", buf[i+j]);
  		}
  		pr_err("%04d: %s\n", i, b);
  	}
  }
  
  static int prot_verify_write(struct scsi_cmnd *SCpnt, sector_t start_sec,
  			     unsigned int sectors, u32 ei_lba)
  {
  	int ret;
  	struct t10_pi_tuple *sdt;
  	void *daddr;
  	sector_t sector = start_sec;
  	int ppage_offset;
  	int dpage_offset;
  	struct sg_mapping_iter diter;
  	struct sg_mapping_iter piter;
  
  	BUG_ON(scsi_sg_count(SCpnt) == 0);
  	BUG_ON(scsi_prot_sg_count(SCpnt) == 0);
  
  	sg_miter_start(&piter, scsi_prot_sglist(SCpnt),
  			scsi_prot_sg_count(SCpnt),
  			SG_MITER_ATOMIC | SG_MITER_FROM_SG);
  	sg_miter_start(&diter, scsi_sglist(SCpnt), scsi_sg_count(SCpnt),
  			SG_MITER_ATOMIC | SG_MITER_FROM_SG);
  
  	/* For each protection page */
  	while (sg_miter_next(&piter)) {
  		dpage_offset = 0;
  		if (WARN_ON(!sg_miter_next(&diter))) {
  			ret = 0x01;
  			goto out;
  		}
  
  		for (ppage_offset = 0; ppage_offset < piter.length;
  		     ppage_offset += sizeof(struct t10_pi_tuple)) {
  			/* If we're at the end of the current
  			 * data page advance to the next one
  			 */
  			if (dpage_offset >= diter.length) {
  				if (WARN_ON(!sg_miter_next(&diter))) {
  					ret = 0x01;
  					goto out;
  				}
  				dpage_offset = 0;
  			}
  
  			sdt = piter.addr + ppage_offset;
  			daddr = diter.addr + dpage_offset;
  
  			ret = dif_verify(sdt, daddr, sector, ei_lba);
  			if (ret) {
  				dump_sector(daddr, sdebug_sector_size);
  				goto out;
  			}
  
  			sector++;
  			ei_lba++;
  			dpage_offset += sdebug_sector_size;
  		}
  		diter.consumed = dpage_offset;
  		sg_miter_stop(&diter);
  	}
  	sg_miter_stop(&piter);
  
  	dif_copy_prot(SCpnt, start_sec, sectors, false);
  	dix_writes++;
  
  	return 0;
  
  out:
  	dif_errors++;
  	sg_miter_stop(&diter);
  	sg_miter_stop(&piter);
  	return ret;
  }
  
  static unsigned long lba_to_map_index(sector_t lba)
  {
  	if (sdebug_unmap_alignment)
  		lba += sdebug_unmap_granularity - sdebug_unmap_alignment;
  	sector_div(lba, sdebug_unmap_granularity);
  	return lba;
  }
  
  static sector_t map_index_to_lba(unsigned long index)
  {
  	sector_t lba = index * sdebug_unmap_granularity;
  
  	if (sdebug_unmap_alignment)
  		lba -= sdebug_unmap_granularity - sdebug_unmap_alignment;
  	return lba;
  }
  
  static unsigned int map_state(sector_t lba, unsigned int *num)
  {
  	sector_t end;
  	unsigned int mapped;
  	unsigned long index;
  	unsigned long next;
  
  	index = lba_to_map_index(lba);
  	mapped = test_bit(index, map_storep);
  
  	if (mapped)
  		next = find_next_zero_bit(map_storep, map_size, index);
  	else
  		next = find_next_bit(map_storep, map_size, index);
  
  	end = min_t(sector_t, sdebug_store_sectors,  map_index_to_lba(next));
  	*num = end - lba;
  	return mapped;
  }
  
  static void map_region(sector_t lba, unsigned int len)
  {
  	sector_t end = lba + len;
  
  	while (lba < end) {
  		unsigned long index = lba_to_map_index(lba);
  
  		if (index < map_size)
  			set_bit(index, map_storep);
  
  		lba = map_index_to_lba(index + 1);
  	}
  }
  
  static void unmap_region(sector_t lba, unsigned int len)
  {
  	sector_t end = lba + len;
  
  	while (lba < end) {
  		unsigned long index = lba_to_map_index(lba);
  
  		if (lba == map_index_to_lba(index) &&
  		    lba + sdebug_unmap_granularity <= end &&
  		    index < map_size) {
  			clear_bit(index, map_storep);
  			if (sdebug_lbprz) {  /* for LBPRZ=2 return 0xff_s */
  				memset(fake_storep +
  				       lba * sdebug_sector_size,
  				       (sdebug_lbprz & 1) ? 0 : 0xff,
  				       sdebug_sector_size *
  				       sdebug_unmap_granularity);
  			}
  			if (dif_storep) {
  				memset(dif_storep + lba, 0xff,
  				       sizeof(*dif_storep) *
  				       sdebug_unmap_granularity);
  			}
  		}
  		lba = map_index_to_lba(index + 1);
  	}
  }
  
  static int resp_write_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
  {
  	u8 *cmd = scp->cmnd;
  	u64 lba;
  	u32 num;
  	u32 ei_lba;
  	unsigned long iflags;
  	int ret;
  	bool check_prot;
  
  	switch (cmd[0]) {
  	case WRITE_16:
  		ei_lba = 0;
  		lba = get_unaligned_be64(cmd + 2);
  		num = get_unaligned_be32(cmd + 10);
  		check_prot = true;
  		break;
  	case WRITE_10:
  		ei_lba = 0;
  		lba = get_unaligned_be32(cmd + 2);
  		num = get_unaligned_be16(cmd + 7);
  		check_prot = true;
  		break;
  	case WRITE_6:
  		ei_lba = 0;
  		lba = (u32)cmd[3] | (u32)cmd[2] << 8 |
  		      (u32)(cmd[1] & 0x1f) << 16;
  		num = (0 == cmd[4]) ? 256 : cmd[4];
  		check_prot = true;
  		break;
  	case WRITE_12:
  		ei_lba = 0;
  		lba = get_unaligned_be32(cmd + 2);
  		num = get_unaligned_be32(cmd + 6);
  		check_prot = true;
  		break;
  	case 0x53:	/* XDWRITEREAD(10) */
  		ei_lba = 0;
  		lba = get_unaligned_be32(cmd + 2);
  		num = get_unaligned_be16(cmd + 7);
  		check_prot = false;
  		break;
  	default:	/* assume WRITE(32) */
  		lba = get_unaligned_be64(cmd + 12);
  		ei_lba = get_unaligned_be32(cmd + 20);
  		num = get_unaligned_be32(cmd + 28);
  		check_prot = false;
  		break;
  	}
  	if (unlikely(have_dif_prot && check_prot)) {
  		if (sdebug_dif == T10_PI_TYPE2_PROTECTION &&
  		    (cmd[1] & 0xe0)) {
  			mk_sense_invalid_opcode(scp);
  			return check_condition_result;
  		}
  		if ((sdebug_dif == T10_PI_TYPE1_PROTECTION ||
  		     sdebug_dif == T10_PI_TYPE3_PROTECTION) &&
  		    (cmd[1] & 0xe0) == 0)
  			sdev_printk(KERN_ERR, scp->device, "Unprotected WR "
  				    "to DIF device\n");
  	}
  	ret = check_device_access_params(scp, lba, num, true);
  	if (ret)
  		return ret;
  	write_lock_irqsave(&atomic_rw, iflags);
  
  	/* DIX + T10 DIF */
  	if (unlikely(sdebug_dix && scsi_prot_sg_count(scp))) {
  		int prot_ret = prot_verify_write(scp, lba, num, ei_lba);
  
  		if (prot_ret) {
  			write_unlock_irqrestore(&atomic_rw, iflags);
  			mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10, prot_ret);
  			return illegal_condition_result;
  		}
  	}
  
  	ret = do_device_access(scp, 0, lba, num, true);
  	if (unlikely(scsi_debug_lbp()))
  		map_region(lba, num);
  	write_unlock_irqrestore(&atomic_rw, iflags);
  	if (unlikely(-1 == ret))
  		return DID_ERROR << 16;
  	else if (unlikely(sdebug_verbose &&
  			  (ret < (num * sdebug_sector_size))))
  		sdev_printk(KERN_INFO, scp->device,
  			    "%s: write: cdb indicated=%u, IO sent=%d bytes\n",
  			    my_name, num * sdebug_sector_size, ret);
  
  	if (unlikely(sdebug_any_injecting_opt)) {
  		struct sdebug_queued_cmd *sqcp =
  				(struct sdebug_queued_cmd *)scp->host_scribble;
  
  		if (sqcp) {
  			if (sqcp->inj_recovered) {
  				mk_sense_buffer(scp, RECOVERED_ERROR,
  						THRESHOLD_EXCEEDED, 0);
  				return check_condition_result;
  			} else if (sqcp->inj_dif) {
  				/* Logical block guard check failed */
  				mk_sense_buffer(scp, ABORTED_COMMAND, 0x10, 1);
  				return illegal_condition_result;
  			} else if (sqcp->inj_dix) {
  				mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10, 1);
  				return illegal_condition_result;
  			}
  		}
  	}
  	return 0;
  }
  
  /*
   * T10 has only specified WRITE SCATTERED(16) and WRITE SCATTERED(32).
   * No READ GATHERED yet (requires bidi or long cdb holding gather list).
   */
  static int resp_write_scat(struct scsi_cmnd *scp,
  			   struct sdebug_dev_info *devip)
  {
  	u8 *cmd = scp->cmnd;
  	u8 *lrdp = NULL;
  	u8 *up;
  	u8 wrprotect;
  	u16 lbdof, num_lrd, k;
  	u32 num, num_by, bt_len, lbdof_blen, sg_off, cum_lb;
  	u32 lb_size = sdebug_sector_size;
  	u32 ei_lba;
  	u64 lba;
  	unsigned long iflags;
  	int ret, res;
  	bool is_16;
  	static const u32 lrd_size = 32; /* + parameter list header size */
  
  	if (cmd[0] == VARIABLE_LENGTH_CMD) {
  		is_16 = false;
  		wrprotect = (cmd[10] >> 5) & 0x7;
  		lbdof = get_unaligned_be16(cmd + 12);
  		num_lrd = get_unaligned_be16(cmd + 16);
  		bt_len = get_unaligned_be32(cmd + 28);
  	} else {        /* that leaves WRITE SCATTERED(16) */
  		is_16 = true;
  		wrprotect = (cmd[2] >> 5) & 0x7;
  		lbdof = get_unaligned_be16(cmd + 4);
  		num_lrd = get_unaligned_be16(cmd + 8);
  		bt_len = get_unaligned_be32(cmd + 10);
  		if (unlikely(have_dif_prot)) {
  			if (sdebug_dif == T10_PI_TYPE2_PROTECTION &&
  			    wrprotect) {
  				mk_sense_invalid_opcode(scp);
  				return illegal_condition_result;
  			}
  			if ((sdebug_dif == T10_PI_TYPE1_PROTECTION ||
  			     sdebug_dif == T10_PI_TYPE3_PROTECTION) &&
  			     wrprotect == 0)
  				sdev_printk(KERN_ERR, scp->device,
  					    "Unprotected WR to DIF device\n");
  		}
  	}
  	if ((num_lrd == 0) || (bt_len == 0))
  		return 0;       /* T10 says these do-nothings are not errors */
  	if (lbdof == 0) {
  		if (sdebug_verbose)
  			sdev_printk(KERN_INFO, scp->device,
  				"%s: %s: LB Data Offset field bad\n",
  				my_name, __func__);
  		mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0);
  		return illegal_condition_result;
  	}
  	lbdof_blen = lbdof * lb_size;
  	if ((lrd_size + (num_lrd * lrd_size)) > lbdof_blen) {
  		if (sdebug_verbose)
  			sdev_printk(KERN_INFO, scp->device,
  				"%s: %s: LBA range descriptors don't fit\n",
  				my_name, __func__);
  		mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0);
  		return illegal_condition_result;
  	}
  	lrdp = kzalloc(lbdof_blen, GFP_ATOMIC);
  	if (lrdp == NULL)
  		return SCSI_MLQUEUE_HOST_BUSY;
  	if (sdebug_verbose)
  		sdev_printk(KERN_INFO, scp->device,
  			"%s: %s: Fetch header+scatter_list, lbdof_blen=%u\n",
  			my_name, __func__, lbdof_blen);
  	res = fetch_to_dev_buffer(scp, lrdp, lbdof_blen);
  	if (res == -1) {
  		ret = DID_ERROR << 16;
  		goto err_out;
  	}
  
  	write_lock_irqsave(&atomic_rw, iflags);
  	sg_off = lbdof_blen;
  	/* Spec says Buffer xfer Length field in number of LBs in dout */
  	cum_lb = 0;
  	for (k = 0, up = lrdp + lrd_size; k < num_lrd; ++k, up += lrd_size) {
  		lba = get_unaligned_be64(up + 0);
  		num = get_unaligned_be32(up + 8);
  		if (sdebug_verbose)
  			sdev_printk(KERN_INFO, scp->device,
  				"%s: %s: k=%d  LBA=0x%llx num=%u  sg_off=%u\n",
  				my_name, __func__, k, lba, num, sg_off);
  		if (num == 0)
  			continue;
  		ret = check_device_access_params(scp, lba, num, true);
  		if (ret)
  			goto err_out_unlock;
  		num_by = num * lb_size;
  		ei_lba = is_16 ? 0 : get_unaligned_be32(up + 12);
  
  		if ((cum_lb + num) > bt_len) {
  			if (sdebug_verbose)
  				sdev_printk(KERN_INFO, scp->device,
  				    "%s: %s: sum of blocks > data provided\n",
  				    my_name, __func__);
  			mk_sense_buffer(scp, ILLEGAL_REQUEST, WRITE_ERROR_ASC,
  					0);
  			ret = illegal_condition_result;
  			goto err_out_unlock;
  		}
  
  		/* DIX + T10 DIF */
  		if (unlikely(sdebug_dix && scsi_prot_sg_count(scp))) {
  			int prot_ret = prot_verify_write(scp, lba, num,
  							 ei_lba);
  
  			if (prot_ret) {
  				mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10,
  						prot_ret);
  				ret = illegal_condition_result;
  				goto err_out_unlock;
  			}
  		}
  
  		ret = do_device_access(scp, sg_off, lba, num, true);
  		if (unlikely(scsi_debug_lbp()))
  			map_region(lba, num);
  		if (unlikely(-1 == ret)) {
  			ret = DID_ERROR << 16;
  			goto err_out_unlock;
  		} else if (unlikely(sdebug_verbose && (ret < num_by)))
  			sdev_printk(KERN_INFO, scp->device,
  			    "%s: write: cdb indicated=%u, IO sent=%d bytes\n",
  			    my_name, num_by, ret);
  
  		if (unlikely(sdebug_any_injecting_opt)) {
  			struct sdebug_queued_cmd *sqcp =
  				(struct sdebug_queued_cmd *)scp->host_scribble;
  
  			if (sqcp) {
  				if (sqcp->inj_recovered) {
  					mk_sense_buffer(scp, RECOVERED_ERROR,
  							THRESHOLD_EXCEEDED, 0);
  					ret = illegal_condition_result;
  					goto err_out_unlock;
  				} else if (sqcp->inj_dif) {
  					/* Logical block guard check failed */
  					mk_sense_buffer(scp, ABORTED_COMMAND,
  							0x10, 1);
  					ret = illegal_condition_result;
  					goto err_out_unlock;
  				} else if (sqcp->inj_dix) {
  					mk_sense_buffer(scp, ILLEGAL_REQUEST,
  							0x10, 1);
  					ret = illegal_condition_result;
  					goto err_out_unlock;
  				}
  			}
  		}
  		sg_off += num_by;
  		cum_lb += num;
  	}
  	ret = 0;
  err_out_unlock:
  	write_unlock_irqrestore(&atomic_rw, iflags);
  err_out:
  	kfree(lrdp);
  	return ret;
  }
  
  static int resp_write_same(struct scsi_cmnd *scp, u64 lba, u32 num,
  			   u32 ei_lba, bool unmap, bool ndob)
  {
  	int ret;
  	unsigned long iflags;
  	unsigned long long i;
  	u32 lb_size = sdebug_sector_size;
  	u64 block, lbaa;
  	u8 *fs1p;
  
  	ret = check_device_access_params(scp, lba, num, true);
  	if (ret)
  		return ret;
  
  	write_lock_irqsave(&atomic_rw, iflags);
  
  	if (unmap && scsi_debug_lbp()) {
  		unmap_region(lba, num);
  		goto out;
  	}
  	lbaa = lba;
  	block = do_div(lbaa, sdebug_store_sectors);
  	/* if ndob then zero 1 logical block, else fetch 1 logical block */
  	fs1p = fake_storep + (block * lb_size);
  	if (ndob) {
  		memset(fs1p, 0, lb_size);
  		ret = 0;
  	} else
  		ret = fetch_to_dev_buffer(scp, fs1p, lb_size);
  
  	if (-1 == ret) {
  		write_unlock_irqrestore(&atomic_rw, iflags);
  		return DID_ERROR << 16;
  	} else if (sdebug_verbose && !ndob && (ret < lb_size))
  		sdev_printk(KERN_INFO, scp->device,
  			    "%s: %s: lb size=%u, IO sent=%d bytes\n",
  			    my_name, "write same", lb_size, ret);
  
  	/* Copy first sector to remaining blocks */
  	for (i = 1 ; i < num ; i++) {
  		lbaa = lba + i;
  		block = do_div(lbaa, sdebug_store_sectors);
  		memmove(fake_storep + (block * lb_size), fs1p, lb_size);
  	}
  	if (scsi_debug_lbp())
  		map_region(lba, num);
  out:
  	write_unlock_irqrestore(&atomic_rw, iflags);
  
  	return 0;
  }
  
  static int resp_write_same_10(struct scsi_cmnd *scp,
  			      struct sdebug_dev_info *devip)
  {
  	u8 *cmd = scp->cmnd;
  	u32 lba;
  	u16 num;
  	u32 ei_lba = 0;
  	bool unmap = false;
  
  	if (cmd[1] & 0x8) {
  		if (sdebug_lbpws10 == 0) {
  			mk_sense_invalid_fld(scp, SDEB_IN_CDB, 1, 3);
  			return check_condition_result;
  		} else
  			unmap = true;
  	}
  	lba = get_unaligned_be32(cmd + 2);
  	num = get_unaligned_be16(cmd + 7);
  	if (num > sdebug_write_same_length) {
  		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 7, -1);
  		return check_condition_result;
  	}
  	return resp_write_same(scp, lba, num, ei_lba, unmap, false);
  }
  
  static int resp_write_same_16(struct scsi_cmnd *scp,
  			      struct sdebug_dev_info *devip)
  {
  	u8 *cmd = scp->cmnd;
  	u64 lba;
  	u32 num;
  	u32 ei_lba = 0;
  	bool unmap = false;
  	bool ndob = false;
  
  	if (cmd[1] & 0x8) {	/* UNMAP */
  		if (sdebug_lbpws == 0) {
  			mk_sense_invalid_fld(scp, SDEB_IN_CDB, 1, 3);
  			return check_condition_result;
  		} else
  			unmap = true;
  	}
  	if (cmd[1] & 0x1)  /* NDOB (no data-out buffer, assumes zeroes) */
  		ndob = true;
  	lba = get_unaligned_be64(cmd + 2);
  	num = get_unaligned_be32(cmd + 10);
  	if (num > sdebug_write_same_length) {
  		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 10, -1);
  		return check_condition_result;
  	}
  	return resp_write_same(scp, lba, num, ei_lba, unmap, ndob);
  }
  
  /* Note the mode field is in the same position as the (lower) service action
   * field. For the Report supported operation codes command, SPC-4 suggests
   * each mode of this command should be reported separately; for future. */
  static int resp_write_buffer(struct scsi_cmnd *scp,
  			     struct sdebug_dev_info *devip)
  {
  	u8 *cmd = scp->cmnd;
  	struct scsi_device *sdp = scp->device;
  	struct sdebug_dev_info *dp;
  	u8 mode;
  
  	mode = cmd[1] & 0x1f;
  	switch (mode) {
  	case 0x4:	/* download microcode (MC) and activate (ACT) */
  		/* set UAs on this device only */
  		set_bit(SDEBUG_UA_BUS_RESET, devip->uas_bm);
  		set_bit(SDEBUG_UA_MICROCODE_CHANGED, devip->uas_bm);
  		break;
  	case 0x5:	/* download MC, save and ACT */
  		set_bit(SDEBUG_UA_MICROCODE_CHANGED_WO_RESET, devip->uas_bm);
  		break;
  	case 0x6:	/* download MC with offsets and ACT */
  		/* set UAs on most devices (LUs) in this target */
  		list_for_each_entry(dp,
  				    &devip->sdbg_host->dev_info_list,
  				    dev_list)
  			if (dp->target == sdp->id) {
  				set_bit(SDEBUG_UA_BUS_RESET, dp->uas_bm);
  				if (devip != dp)
  					set_bit(SDEBUG_UA_MICROCODE_CHANGED,
  						dp->uas_bm);
  			}
  		break;
  	case 0x7:	/* download MC with offsets, save, and ACT */
  		/* set UA on all devices (LUs) in this target */
  		list_for_each_entry(dp,
  				    &devip->sdbg_host->dev_info_list,
  				    dev_list)
  			if (dp->target == sdp->id)
  				set_bit(SDEBUG_UA_MICROCODE_CHANGED_WO_RESET,
  					dp->uas_bm);
  		break;
  	default:
  		/* do nothing for this command for other mode values */
  		break;
  	}
  	return 0;
  }
  
  static int resp_comp_write(struct scsi_cmnd *scp,
  			   struct sdebug_dev_info *devip)
  {
  	u8 *cmd = scp->cmnd;
  	u8 *arr;
  	u8 *fake_storep_hold;
  	u64 lba;
  	u32 dnum;
  	u32 lb_size = sdebug_sector_size;
  	u8 num;
  	unsigned long iflags;
  	int ret;
  	int retval = 0;
  
  	lba = get_unaligned_be64(cmd + 2);
  	num = cmd[13];		/* 1 to a maximum of 255 logical blocks */
  	if (0 == num)
  		return 0;	/* degenerate case, not an error */
  	if (sdebug_dif == T10_PI_TYPE2_PROTECTION &&
  	    (cmd[1] & 0xe0)) {
  		mk_sense_invalid_opcode(scp);
  		return check_condition_result;
  	}
  	if ((sdebug_dif == T10_PI_TYPE1_PROTECTION ||
  	     sdebug_dif == T10_PI_TYPE3_PROTECTION) &&
  	    (cmd[1] & 0xe0) == 0)
  		sdev_printk(KERN_ERR, scp->device, "Unprotected WR "
  			    "to DIF device\n");
  	ret = check_device_access_params(scp, lba, num, false);
  	if (ret)
  		return ret;
  	dnum = 2 * num;
  	arr = kcalloc(lb_size, dnum, GFP_ATOMIC);
  	if (NULL == arr) {
  		mk_sense_buffer(scp, ILLEGAL_REQUEST, INSUFF_RES_ASC,
  				INSUFF_RES_ASCQ);
  		return check_condition_result;
  	}
  
  	write_lock_irqsave(&atomic_rw, iflags);
  
  	/* trick do_device_access() to fetch both compare and write buffers
  	 * from data-in into arr. Safe (atomic) since write_lock held. */
  	fake_storep_hold = fake_storep;
  	fake_storep = arr;
  	ret = do_device_access(scp, 0, 0, dnum, true);
  	fake_storep = fake_storep_hold;
  	if (ret == -1) {
  		retval = DID_ERROR << 16;
  		goto cleanup;
  	} else if (sdebug_verbose && (ret < (dnum * lb_size)))
  		sdev_printk(KERN_INFO, scp->device, "%s: compare_write: cdb "
  			    "indicated=%u, IO sent=%d bytes\n", my_name,
  			    dnum * lb_size, ret);
  	if (!comp_write_worker(lba, num, arr)) {
  		mk_sense_buffer(scp, MISCOMPARE, MISCOMPARE_VERIFY_ASC, 0);
  		retval = check_condition_result;
  		goto cleanup;
  	}
  	if (scsi_debug_lbp())
  		map_region(lba, num);
  cleanup:
  	write_unlock_irqrestore(&atomic_rw, iflags);
  	kfree(arr);
  	return retval;
  }
  
  struct unmap_block_desc {
  	__be64	lba;
  	__be32	blocks;
  	__be32	__reserved;
  };
  
  static int resp_unmap(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
  {
  	unsigned char *buf;
  	struct unmap_block_desc *desc;
  	unsigned int i, payload_len, descriptors;
  	int ret;
  	unsigned long iflags;
  
  
  	if (!scsi_debug_lbp())
  		return 0;	/* fib and say its done */
  	payload_len = get_unaligned_be16(scp->cmnd + 7);
  	BUG_ON(scsi_bufflen(scp) != payload_len);
  
  	descriptors = (payload_len - 8) / 16;
  	if (descriptors > sdebug_unmap_max_desc) {
  		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 7, -1);
  		return check_condition_result;
  	}
  
  	buf = kzalloc(scsi_bufflen(scp), GFP_ATOMIC);
  	if (!buf) {
  		mk_sense_buffer(scp, ILLEGAL_REQUEST, INSUFF_RES_ASC,
  				INSUFF_RES_ASCQ);
  		return check_condition_result;
  	}
  
  	scsi_sg_copy_to_buffer(scp, buf, scsi_bufflen(scp));
  
  	BUG_ON(get_unaligned_be16(&buf[0]) != payload_len - 2);
  	BUG_ON(get_unaligned_be16(&buf[2]) != descriptors * 16);
  
  	desc = (void *)&buf[8];
  
  	write_lock_irqsave(&atomic_rw, iflags);
  
  	for (i = 0 ; i < descriptors ; i++) {
  		unsigned long long lba = get_unaligned_be64(&desc[i].lba);
  		unsigned int num = get_unaligned_be32(&desc[i].blocks);
  
  		ret = check_device_access_params(scp, lba, num, true);
  		if (ret)
  			goto out;
  
  		unmap_region(lba, num);
  	}
  
  	ret = 0;
  
  out:
  	write_unlock_irqrestore(&atomic_rw, iflags);
  	kfree(buf);
  
  	return ret;
  }
  
  #define SDEBUG_GET_LBA_STATUS_LEN 32
  
  static int resp_get_lba_status(struct scsi_cmnd *scp,
  			       struct sdebug_dev_info *devip)
  {
  	u8 *cmd = scp->cmnd;
  	u64 lba;
  	u32 alloc_len, mapped, num;
  	u8 arr[SDEBUG_GET_LBA_STATUS_LEN];
  	int ret;
  
  	lba = get_unaligned_be64(cmd + 2);
  	alloc_len = get_unaligned_be32(cmd + 10);
  
  	if (alloc_len < 24)
  		return 0;
  
  	ret = check_device_access_params(scp, lba, 1, false);
  	if (ret)
  		return ret;
  
  	if (scsi_debug_lbp())
  		mapped = map_state(lba, &num);
  	else {
  		mapped = 1;
  		/* following just in case virtual_gb changed */
  		sdebug_capacity = get_sdebug_capacity();
  		if (sdebug_capacity - lba <= 0xffffffff)
  			num = sdebug_capacity - lba;
  		else
  			num = 0xffffffff;
  	}
  
  	memset(arr, 0, SDEBUG_GET_LBA_STATUS_LEN);
  	put_unaligned_be32(20, arr);		/* Parameter Data Length */
  	put_unaligned_be64(lba, arr + 8);	/* LBA */
  	put_unaligned_be32(num, arr + 16);	/* Number of blocks */
  	arr[20] = !mapped;		/* prov_stat=0: mapped; 1: dealloc */
  
  	return fill_from_dev_buffer(scp, arr, SDEBUG_GET_LBA_STATUS_LEN);
  }
  
  static int resp_sync_cache(struct scsi_cmnd *scp,
  			   struct sdebug_dev_info *devip)
  {
  	int res = 0;
  	u64 lba;
  	u32 num_blocks;
  	u8 *cmd = scp->cmnd;
  
  	if (cmd[0] == SYNCHRONIZE_CACHE) {	/* 10 byte cdb */
  		lba = get_unaligned_be32(cmd + 2);
  		num_blocks = get_unaligned_be16(cmd + 7);
  	} else {				/* SYNCHRONIZE_CACHE(16) */
  		lba = get_unaligned_be64(cmd + 2);
  		num_blocks = get_unaligned_be32(cmd + 10);
  	}
  	if (lba + num_blocks > sdebug_capacity) {
  		mk_sense_buffer(scp, ILLEGAL_REQUEST, LBA_OUT_OF_RANGE, 0);
  		return check_condition_result;
  	}
  	if (!write_since_sync || cmd[1] & 0x2)
  		res = SDEG_RES_IMMED_MASK;
  	else		/* delay if write_since_sync and IMMED clear */
  		write_since_sync = false;
  	return res;
  }
  
  #define RL_BUCKET_ELEMS 8
  
  /* Even though each pseudo target has a REPORT LUNS "well known logical unit"
   * (W-LUN), the normal Linux scanning logic does not associate it with a
   * device (e.g. /dev/sg7). The following magic will make that association:
   *   "cd /sys/class/scsi_host/host<n> ; echo '- - 49409' > scan"
   * where <n> is a host number. If there are multiple targets in a host then
   * the above will associate a W-LUN to each target. To only get a W-LUN
   * for target 2, then use "echo '- 2 49409' > scan" .
   */
  static int resp_report_luns(struct scsi_cmnd *scp,
  			    struct sdebug_dev_info *devip)
  {
  	unsigned char *cmd = scp->cmnd;
  	unsigned int alloc_len;
  	unsigned char select_report;
  	u64 lun;
  	struct scsi_lun *lun_p;
  	u8 arr[RL_BUCKET_ELEMS * sizeof(struct scsi_lun)];
  	unsigned int lun_cnt;	/* normal LUN count (max: 256) */
  	unsigned int wlun_cnt;	/* report luns W-LUN count */
  	unsigned int tlun_cnt;	/* total LUN count */
  	unsigned int rlen;	/* response length (in bytes) */
  	int k, j, n, res;
  	unsigned int off_rsp = 0;
  	const int sz_lun = sizeof(struct scsi_lun);
  
  	clear_luns_changed_on_target(devip);
  
  	select_report = cmd[2];
  	alloc_len = get_unaligned_be32(cmd + 6);
  
  	if (alloc_len < 4) {
  		pr_err("alloc len too small %d\n", alloc_len);
  		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 6, -1);
  		return check_condition_result;
  	}
  
  	switch (select_report) {
  	case 0:		/* all LUNs apart from W-LUNs */
  		lun_cnt = sdebug_max_luns;
  		wlun_cnt = 0;
  		break;
  	case 1:		/* only W-LUNs */
  		lun_cnt = 0;
  		wlun_cnt = 1;
  		break;
  	case 2:		/* all LUNs */
  		lun_cnt = sdebug_max_luns;
  		wlun_cnt = 1;
  		break;
  	case 0x10:	/* only administrative LUs */
  	case 0x11:	/* see SPC-5 */
  	case 0x12:	/* only subsiduary LUs owned by referenced LU */
  	default:
  		pr_debug("select report invalid %d\n", select_report);
  		mk_sense_invalid_fld(scp, SDEB_IN_CDB, 2, -1);
  		return check_condition_result;
  	}
  
  	if (sdebug_no_lun_0 && (lun_cnt > 0))
  		--lun_cnt;
  
  	tlun_cnt = lun_cnt + wlun_cnt;
  	rlen = tlun_cnt * sz_lun;	/* excluding 8 byte header */
  	scsi_set_resid(scp, scsi_bufflen(scp));
  	pr_debug("select_report %d luns = %d wluns = %d no_lun0 %d\n",
  		 select_report, lun_cnt, wlun_cnt, sdebug_no_lun_0);
  
  	/* loops rely on sizeof response header same as sizeof lun (both 8) */
  	lun = sdebug_no_lun_0 ? 1 : 0;
  	for (k = 0, j = 0, res = 0; true; ++k, j = 0) {
  		memset(arr, 0, sizeof(arr));
  		lun_p = (struct scsi_lun *)&arr[0];
  		if (k == 0) {
  			put_unaligned_be32(rlen, &arr[0]);
  			++lun_p;
  			j = 1;
  		}
  		for ( ; j < RL_BUCKET_ELEMS; ++j, ++lun_p) {
  			if ((k * RL_BUCKET_ELEMS) + j > lun_cnt)
  				break;
  			int_to_scsilun(lun++, lun_p);
  		}
  		if (j < RL_BUCKET_ELEMS)
  			break;
  		n = j * sz_lun;
  		res = p_fill_from_dev_buffer(scp, arr, n, off_rsp);
  		if (res)
  			return res;
  		off_rsp += n;
  	}
  	if (wlun_cnt) {
  		int_to_scsilun(SCSI_W_LUN_REPORT_LUNS, lun_p);
  		++j;
  	}
  	if (j > 0)
  		res = p_fill_from_dev_buffer(scp, arr, j * sz_lun, off_rsp);
  	return res;
  }
  
  static struct sdebug_queue *get_queue(struct scsi_cmnd *cmnd)
  {
  	u32 tag = blk_mq_unique_tag(cmnd->request);
  	u16 hwq = blk_mq_unique_tag_to_hwq(tag);
  
  	pr_debug("tag=%#x, hwq=%d\n", tag, hwq);
  	if (WARN_ON_ONCE(hwq >= submit_queues))
  		hwq = 0;
  	return sdebug_q_arr + hwq;
  }
  
  /* Queued (deferred) command completions converge here. */
  static void sdebug_q_cmd_complete(struct sdebug_defer *sd_dp)
  {
  	bool aborted = sd_dp->aborted;
  	int qc_idx;
  	int retiring = 0;
  	unsigned long iflags;
  	struct sdebug_queue *sqp;
  	struct sdebug_queued_cmd *sqcp;
  	struct scsi_cmnd *scp;
  	struct sdebug_dev_info *devip;
  
  	sd_dp->defer_t = SDEB_DEFER_NONE;
  	if (unlikely(aborted))
  		sd_dp->aborted = false;
  	qc_idx = sd_dp->qc_idx;
  	sqp = sdebug_q_arr + sd_dp->sqa_idx;
  	if (sdebug_statistics) {
  		atomic_inc(&sdebug_completions);
  		if (raw_smp_processor_id() != sd_dp->issuing_cpu)
  			atomic_inc(&sdebug_miss_cpus);
  	}
  	if (unlikely((qc_idx < 0) || (qc_idx >= SDEBUG_CANQUEUE))) {
  		pr_err("wild qc_idx=%d\n", qc_idx);
  		return;
  	}
  	spin_lock_irqsave(&sqp->qc_lock, iflags);
  	sqcp = &sqp->qc_arr[qc_idx];
  	scp = sqcp->a_cmnd;
  	if (unlikely(scp == NULL)) {
  		spin_unlock_irqrestore(&sqp->qc_lock, iflags);
  		pr_err("scp is NULL, sqa_idx=%d, qc_idx=%d\n",
  		       sd_dp->sqa_idx, qc_idx);
  		return;
  	}
  	devip = (struct sdebug_dev_info *)scp->device->hostdata;
  	if (likely(devip))
  		atomic_dec(&devip->num_in_q);
  	else
  		pr_err("devip=NULL\n");
  	if (unlikely(atomic_read(&retired_max_queue) > 0))
  		retiring = 1;
  
  	sqcp->a_cmnd = NULL;
  	if (unlikely(!test_and_clear_bit(qc_idx, sqp->in_use_bm))) {
  		spin_unlock_irqrestore(&sqp->qc_lock, iflags);
  		pr_err("Unexpected completion\n");
  		return;
  	}
  
  	if (unlikely(retiring)) {	/* user has reduced max_queue */
  		int k, retval;
  
  		retval = atomic_read(&retired_max_queue);
  		if (qc_idx >= retval) {
  			spin_unlock_irqrestore(&sqp->qc_lock, iflags);
  			pr_err("index %d too large\n", retval);
  			return;
  		}
  		k = find_last_bit(sqp->in_use_bm, retval);
  		if ((k < sdebug_max_queue) || (k == retval))
  			atomic_set(&retired_max_queue, 0);
  		else
  			atomic_set(&retired_max_queue, k + 1);
  	}
  	spin_unlock_irqrestore(&sqp->qc_lock, iflags);
  	if (unlikely(aborted)) {
  		if (sdebug_verbose)
  			pr_info("bypassing scsi_done() due to aborted cmd\n");
  		return;
  	}
  	scp->scsi_done(scp); /* callback to mid level */
  }
  
  /* When high resolution timer goes off this function is called. */
  static enum hrtimer_restart sdebug_q_cmd_hrt_complete(struct hrtimer *timer)
  {
  	struct sdebug_defer *sd_dp = container_of(timer, struct sdebug_defer,
  						  hrt);
  	sdebug_q_cmd_complete(sd_dp);
  	return HRTIMER_NORESTART;
  }
  
  /* When work queue schedules work, it calls this function. */
  static void sdebug_q_cmd_wq_complete(struct work_struct *work)
  {
  	struct sdebug_defer *sd_dp = container_of(work, struct sdebug_defer,
  						  ew.work);
  	sdebug_q_cmd_complete(sd_dp);
  }
  
  static bool got_shared_uuid;
  static uuid_t shared_uuid;
  
  static struct sdebug_dev_info *sdebug_device_create(
  			struct sdebug_host_info *sdbg_host, gfp_t flags)
  {
  	struct sdebug_dev_info *devip;
  
  	devip = kzalloc(sizeof(*devip), flags);
  	if (devip) {
  		if (sdebug_uuid_ctl == 1)
  			uuid_gen(&devip->lu_name);
  		else if (sdebug_uuid_ctl == 2) {
  			if (got_shared_uuid)
  				devip->lu_name = shared_uuid;
  			else {
  				uuid_gen(&shared_uuid);
  				got_shared_uuid = true;
  				devip->lu_name = shared_uuid;
  			}
  		}
  		devip->sdbg_host = sdbg_host;
  		list_add_tail(&devip->dev_list, &sdbg_host->dev_info_list);
  	}
  	return devip;
  }
  
  static struct sdebug_dev_info *find_build_dev_info(struct scsi_device *sdev)
  {
  	struct sdebug_host_info *sdbg_host;
  	struct sdebug_dev_info *open_devip = NULL;
  	struct sdebug_dev_info *devip;
  
  	sdbg_host = *(struct sdebug_host_info **)shost_priv(sdev->host);
  	if (!sdbg_host) {
  		pr_err("Host info NULL\n");
  		return NULL;
  	}
  	list_for_each_entry(devip, &sdbg_host->dev_info_list, dev_list) {
  		if ((devip->used) && (devip->channel == sdev->channel) &&
  		    (devip->target == sdev->id) &&
  		    (devip->lun == sdev->lun))
  			return devip;
  		else {
  			if ((!devip->used) && (!open_devip))
  				open_devip = devip;
  		}
  	}
  	if (!open_devip) { /* try and make a new one */
  		open_devip = sdebug_device_create(sdbg_host, GFP_ATOMIC);
  		if (!open_devip) {
  			pr_err("out of memory at line %d\n", __LINE__);
  			return NULL;
  		}
  	}
  
  	open_devip->channel = sdev->channel;
  	open_devip->target = sdev->id;
  	open_devip->lun = sdev->lun;
  	open_devip->sdbg_host = sdbg_host;
  	atomic_set(&open_devip->num_in_q, 0);
  	set_bit(SDEBUG_UA_POR, open_devip->uas_bm);
  	open_devip->used = true;
  	return open_devip;
  }
  
  static int scsi_debug_slave_alloc(struct scsi_device *sdp)
  {
  	if (sdebug_verbose)
  		pr_info("slave_alloc <%u %u %u %llu>\n",
  		       sdp->host->host_no, sdp->channel, sdp->id, sdp->lun);
  	return 0;
  }
  
  static int scsi_debug_slave_configure(struct scsi_device *sdp)
  {
  	struct sdebug_dev_info *devip =
  			(struct sdebug_dev_info *)sdp->hostdata;
  
  	if (sdebug_verbose)
  		pr_info("slave_configure <%u %u %u %llu>\n",
  		       sdp->host->host_no, sdp->channel, sdp->id, sdp->lun);
  	if (sdp->host->max_cmd_len != SDEBUG_MAX_CMD_LEN)
  		sdp->host->max_cmd_len = SDEBUG_MAX_CMD_LEN;
  	if (devip == NULL) {
  		devip = find_build_dev_info(sdp);
  		if (devip == NULL)
  			return 1;  /* no resources, will be marked offline */
  	}
  	sdp->hostdata = devip;
  	if (sdebug_no_uld)
  		sdp->no_uld_attach = 1;
  	config_cdb_len(sdp);
  	return 0;
  }
  
  static void scsi_debug_slave_destroy(struct scsi_device *sdp)
  {
  	struct sdebug_dev_info *devip =
  		(struct sdebug_dev_info *)sdp->hostdata;
  
  	if (sdebug_verbose)
  		pr_info("slave_destroy <%u %u %u %llu>\n",
  		       sdp->host->host_no, sdp->channel, sdp->id, sdp->lun);
  	if (devip) {
  		/* make this slot available for re-use */
  		devip->used = false;
  		sdp->hostdata = NULL;
  	}
  }
  
  static void stop_qc_helper(struct sdebug_defer *sd_dp,
  			   enum sdeb_defer_type defer_t)
  {
  	if (!sd_dp)
  		return;
  	if (defer_t == SDEB_DEFER_HRT)
  		hrtimer_cancel(&sd_dp->hrt);
  	else if (defer_t == SDEB_DEFER_WQ)
  		cancel_work_sync(&sd_dp->ew.work);
  }
  
  /* If @cmnd found deletes its timer or work queue and returns true; else
     returns false */
  static bool stop_queued_cmnd(struct scsi_cmnd *cmnd)
  {
  	unsigned long iflags;
  	int j, k, qmax, r_qmax;
  	enum sdeb_defer_type l_defer_t;
  	struct sdebug_queue *sqp;
  	struct sdebug_queued_cmd *sqcp;
  	struct sdebug_dev_info *devip;
  	struct sdebug_defer *sd_dp;
  
  	for (j = 0, sqp = sdebug_q_arr; j < submit_queues; ++j, ++sqp) {
  		spin_lock_irqsave(&sqp->qc_lock, iflags);
  		qmax = sdebug_max_queue;
  		r_qmax = atomic_read(&retired_max_queue);
  		if (r_qmax > qmax)
  			qmax = r_qmax;
  		for (k = 0; k < qmax; ++k) {
  			if (test_bit(k, sqp->in_use_bm)) {
  				sqcp = &sqp->qc_arr[k];
  				if (cmnd != sqcp->a_cmnd)
  					continue;
  				/* found */
  				devip = (struct sdebug_dev_info *)
  						cmnd->device->hostdata;
  				if (devip)
  					atomic_dec(&devip->num_in_q);
  				sqcp->a_cmnd = NULL;
  				sd_dp = sqcp->sd_dp;
  				if (sd_dp) {
  					l_defer_t = sd_dp->defer_t;
  					sd_dp->defer_t = SDEB_DEFER_NONE;
  				} else
  					l_defer_t = SDEB_DEFER_NONE;
  				spin_unlock_irqrestore(&sqp->qc_lock, iflags);
  				stop_qc_helper(sd_dp, l_defer_t);
  				clear_bit(k, sqp->in_use_bm);
  				return true;
  			}
  		}
  		spin_unlock_irqrestore(&sqp->qc_lock, iflags);
  	}
  	return false;
  }
  
  /* Deletes (stops) timers or work queues of all queued commands */
  static void stop_all_queued(void)
  {
  	unsigned long iflags;
  	int j, k;
  	enum sdeb_defer_type l_defer_t;
  	struct sdebug_queue *sqp;
  	struct sdebug_queued_cmd *sqcp;
  	struct sdebug_dev_info *devip;
  	struct sdebug_defer *sd_dp;
  
  	for (j = 0, sqp = sdebug_q_arr; j < submit_queues; ++j, ++sqp) {
  		spin_lock_irqsave(&sqp->qc_lock, iflags);
  		for (k = 0; k < SDEBUG_CANQUEUE; ++k) {
  			if (test_bit(k, sqp->in_use_bm)) {
  				sqcp = &sqp->qc_arr[k];
  				if (sqcp->a_cmnd == NULL)
  					continue;
  				devip = (struct sdebug_dev_info *)
  					sqcp->a_cmnd->device->hostdata;
  				if (devip)
  					atomic_dec(&devip->num_in_q);
  				sqcp->a_cmnd = NULL;
  				sd_dp = sqcp->sd_dp;
  				if (sd_dp) {
  					l_defer_t = sd_dp->defer_t;
  					sd_dp->defer_t = SDEB_DEFER_NONE;
  				} else
  					l_defer_t = SDEB_DEFER_NONE;
  				spin_unlock_irqrestore(&sqp->qc_lock, iflags);
  				stop_qc_helper(sd_dp, l_defer_t);
  				clear_bit(k, sqp->in_use_bm);
  				spin_lock_irqsave(&sqp->qc_lock, iflags);
  			}
  		}
  		spin_unlock_irqrestore(&sqp->qc_lock, iflags);
  	}
  }
  
  /* Free queued command memory on heap */
  static void free_all_queued(void)
  {
  	int j, k;
  	struct sdebug_queue *sqp;
  	struct sdebug_queued_cmd *sqcp;
  
  	for (j = 0, sqp = sdebug_q_arr; j < submit_queues; ++j, ++sqp) {
  		for (k = 0; k < SDEBUG_CANQUEUE; ++k) {
  			sqcp = &sqp->qc_arr[k];
  			kfree(sqcp->sd_dp);
  			sqcp->sd_dp = NULL;
  		}
  	}
  }
  
  static int scsi_debug_abort(struct scsi_cmnd *SCpnt)
  {
  	bool ok;
  
  	++num_aborts;
  	if (SCpnt) {
  		ok = stop_queued_cmnd(SCpnt);
  		if (SCpnt->device && (SDEBUG_OPT_ALL_NOISE & sdebug_opts))
  			sdev_printk(KERN_INFO, SCpnt->device,
  				    "%s: command%s found\n", __func__,
  				    ok ? "" : " not");
  	}
  	return SUCCESS;
  }
  
  static int scsi_debug_device_reset(struct scsi_cmnd *SCpnt)
  {
  	++num_dev_resets;
  	if (SCpnt && SCpnt->device) {
  		struct scsi_device *sdp = SCpnt->device;
  		struct sdebug_dev_info *devip =
  				(struct sdebug_dev_info *)sdp->hostdata;
  
  		if (SDEBUG_OPT_ALL_NOISE & sdebug_opts)
  			sdev_printk(KERN_INFO, sdp, "%s\n", __func__);
  		if (devip)
  			set_bit(SDEBUG_UA_POR, devip->uas_bm);
  	}
  	return SUCCESS;
  }
  
  static int scsi_debug_target_reset(struct scsi_cmnd *SCpnt)
  {
  	struct sdebug_host_info *sdbg_host;
  	struct sdebug_dev_info *devip;
  	struct scsi_device *sdp;
  	struct Scsi_Host *hp;
  	int k = 0;
  
  	++num_target_resets;
  	if (!SCpnt)
  		goto lie;
  	sdp = SCpnt->device;
  	if (!sdp)
  		goto lie;
  	if (SDEBUG_OPT_ALL_NOISE & sdebug_opts)
  		sdev_printk(KERN_INFO, sdp, "%s\n", __func__);
  	hp = sdp->host;
  	if (!hp)
  		goto lie;
  	sdbg_host = *(struct sdebug_host_info **)shost_priv(hp);
  	if (sdbg_host) {
  		list_for_each_entry(devip,
  				    &sdbg_host->dev_info_list,
  				    dev_list)
  			if (devip->target == sdp->id) {
  				set_bit(SDEBUG_UA_BUS_RESET, devip->uas_bm);
  				++k;
  			}
  	}
  	if (SDEBUG_OPT_RESET_NOISE & sdebug_opts)
  		sdev_printk(KERN_INFO, sdp,
  			    "%s: %d device(s) found in target\n", __func__, k);
  lie:
  	return SUCCESS;
  }
  
  static int scsi_debug_bus_reset(struct scsi_cmnd *SCpnt)
  {
  	struct sdebug_host_info *sdbg_host;
  	struct sdebug_dev_info *devip;
  	struct scsi_device *sdp;
  	struct Scsi_Host *hp;
  	int k = 0;
  
  	++num_bus_resets;
  	if (!(SCpnt && SCpnt->device))
  		goto lie;
  	sdp = SCpnt->device;
  	if (SDEBUG_OPT_ALL_NOISE & sdebug_opts)
  		sdev_printk(KERN_INFO, sdp, "%s\n", __func__);
  	hp = sdp->host;
  	if (hp) {
  		sdbg_host = *(struct sdebug_host_info **)shost_priv(hp);
  		if (sdbg_host) {
  			list_for_each_entry(devip,
  					    &sdbg_host->dev_info_list,
  					    dev_list) {
  				set_bit(SDEBUG_UA_BUS_RESET, devip->uas_bm);
  				++k;
  			}
  		}
  	}
  	if (SDEBUG_OPT_RESET_NOISE & sdebug_opts)
  		sdev_printk(KERN_INFO, sdp,
  			    "%s: %d device(s) found in host\n", __func__, k);
  lie:
  	return SUCCESS;
  }
  
  static int scsi_debug_host_reset(struct scsi_cmnd *SCpnt)
  {
  	struct sdebug_host_info *sdbg_host;
  	struct sdebug_dev_info *devip;
  	int k = 0;
  
  	++num_host_resets;
  	if ((SCpnt->device) && (SDEBUG_OPT_ALL_NOISE & sdebug_opts))
  		sdev_printk(KERN_INFO, SCpnt->device, "%s\n", __func__);
  	spin_lock(&sdebug_host_list_lock);
  	list_for_each_entry(sdbg_host, &sdebug_host_list, host_list) {
  		list_for_each_entry(devip, &sdbg_host->dev_info_list,
  				    dev_list) {
  			set_bit(SDEBUG_UA_BUS_RESET, devip->uas_bm);
  			++k;
  		}
  	}
  	spin_unlock(&sdebug_host_list_lock);
  	stop_all_queued();
  	if (SDEBUG_OPT_RESET_NOISE & sdebug_opts)
  		sdev_printk(KERN_INFO, SCpnt->device,
  			    "%s: %d device(s) found\n", __func__, k);
  	return SUCCESS;
  }
  
  static void __init sdebug_build_parts(unsigned char *ramp,
  				      unsigned long store_size)
  {
  	struct partition *pp;
  	int starts[SDEBUG_MAX_PARTS + 2];
  	int sectors_per_part, num_sectors, k;
  	int heads_by_sects, start_sec, end_sec;
  
  	/* assume partition table already zeroed */
  	if ((sdebug_num_parts < 1) || (store_size < 1048576))
  		return;
  	if (sdebug_num_parts > SDEBUG_MAX_PARTS) {
  		sdebug_num_parts = SDEBUG_MAX_PARTS;
  		pr_warn("reducing partitions to %d\n", SDEBUG_MAX_PARTS);
  	}
  	num_sectors = (int)sdebug_store_sectors;
  	sectors_per_part = (num_sectors - sdebug_sectors_per)
  			   / sdebug_num_parts;
  	heads_by_sects = sdebug_heads * sdebug_sectors_per;
  	starts[0] = sdebug_sectors_per;
  	for (k = 1; k < sdebug_num_parts; ++k)
  		starts[k] = ((k * sectors_per_part) / heads_by_sects)
  			    * heads_by_sects;
  	starts[sdebug_num_parts] = num_sectors;
  	starts[sdebug_num_parts + 1] = 0;
  
  	ramp[510] = 0x55;	/* magic partition markings */
  	ramp[511] = 0xAA;
  	pp = (struct partition *)(ramp + 0x1be);
  	for (k = 0; starts[k + 1]; ++k, ++pp) {
  		start_sec = starts[k];
  		end_sec = starts[k + 1] - 1;
  		pp->boot_ind = 0;
  
  		pp->cyl = start_sec / heads_by_sects;
  		pp->head = (start_sec - (pp->cyl * heads_by_sects))
  			   / sdebug_sectors_per;
  		pp->sector = (start_sec % sdebug_sectors_per) + 1;
  
  		pp->end_cyl = end_sec / heads_by_sects;
  		pp->end_head = (end_sec - (pp->end_cyl * heads_by_sects))
  			       / sdebug_sectors_per;
  		pp->end_sector = (end_sec % sdebug_sectors_per) + 1;
  
  		pp->start_sect = cpu_to_le32(start_sec);
  		pp->nr_sects = cpu_to_le32(end_sec - start_sec + 1);
  		pp->sys_ind = 0x83;	/* plain Linux partition */
  	}
  }
  
  static void block_unblock_all_queues(bool block)
  {
  	int j;
  	struct sdebug_queue *sqp;
  
  	for (j = 0, sqp = sdebug_q_arr; j < submit_queues; ++j, ++sqp)
  		atomic_set(&sqp->blocked, (int)block);
  }
  
  /* Adjust (by rounding down) the sdebug_cmnd_count so abs(every_nth)-1
   * commands will be processed normally before triggers occur.
   */
  static void tweak_cmnd_count(void)
  {
  	int count, modulo;
  
  	modulo = abs(sdebug_every_nth);
  	if (modulo < 2)
  		return;
  	block_unblock_all_queues(true);
  	count = atomic_read(&sdebug_cmnd_count);
  	atomic_set(&sdebug_cmnd_count, (count / modulo) * modulo);
  	block_unblock_all_queues(false);
  }
  
  static void clear_queue_stats(void)
  {
  	atomic_set(&sdebug_cmnd_count, 0);
  	atomic_set(&sdebug_completions, 0);
  	atomic_set(&sdebug_miss_cpus, 0);
  	atomic_set(&sdebug_a_tsf, 0);
  }
  
  static void setup_inject(struct sdebug_queue *sqp,
  			 struct sdebug_queued_cmd *sqcp)
  {
  	if ((atomic_read(&sdebug_cmnd_count) % abs(sdebug_every_nth)) > 0) {
  		if (sdebug_every_nth > 0)
  			sqcp->inj_recovered = sqcp->inj_transport
  				= sqcp->inj_dif
  				= sqcp->inj_dix = sqcp->inj_short
  				= sqcp->inj_host_busy = sqcp->inj_cmd_abort = 0;
  		return;
  	}
  	sqcp->inj_recovered = !!(SDEBUG_OPT_RECOVERED_ERR & sdebug_opts);
  	sqcp->inj_transport = !!(SDEBUG_OPT_TRANSPORT_ERR & sdebug_opts);
  	sqcp->inj_dif = !!(SDEBUG_OPT_DIF_ERR & sdebug_opts);
  	sqcp->inj_dix = !!(SDEBUG_OPT_DIX_ERR & sdebug_opts);
  	sqcp->inj_short = !!(SDEBUG_OPT_SHORT_TRANSFER & sdebug_opts);
  	sqcp->inj_host_busy = !!(SDEBUG_OPT_HOST_BUSY & sdebug_opts);
  	sqcp->inj_cmd_abort = !!(SDEBUG_OPT_CMD_ABORT & sdebug_opts);
  }
  
  /* Complete the processing of the thread that queued a SCSI command to this
   * driver. It either completes the command by calling cmnd_done() or
   * schedules a hr timer or work queue then returns 0. Returns
   * SCSI_MLQUEUE_HOST_BUSY if temporarily out of resources.
   */
  static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
  			 int scsi_result,
  			 int (*pfp)(struct scsi_cmnd *,
  				    struct sdebug_dev_info *),
  			 int delta_jiff, int ndelay)
  {
  	unsigned long iflags;
  	int k, num_in_q, qdepth, inject;
  	struct sdebug_queue *sqp;
  	struct sdebug_queued_cmd *sqcp;
  	struct scsi_device *sdp;
  	struct sdebug_defer *sd_dp;
  
  	if (unlikely(devip == NULL)) {
  		if (scsi_result == 0)
  			scsi_result = DID_NO_CONNECT << 16;
  		goto respond_in_thread;
  	}
  	sdp = cmnd->device;
  
  	if (delta_jiff == 0)
  		goto respond_in_thread;
  
  	/* schedule the response at a later time if resources permit */
  	sqp = get_queue(cmnd);
  	spin_lock_irqsave(&sqp->qc_lock, iflags);
  	if (unlikely(atomic_read(&sqp->blocked))) {
  		spin_unlock_irqrestore(&sqp->qc_lock, iflags);
  		return SCSI_MLQUEUE_HOST_BUSY;
  	}
  	num_in_q = atomic_read(&devip->num_in_q);
  	qdepth = cmnd->device->queue_depth;
  	inject = 0;
  	if (unlikely((qdepth > 0) && (num_in_q >= qdepth))) {
  		if (scsi_result) {
  			spin_unlock_irqrestore(&sqp->qc_lock, iflags);
  			goto respond_in_thread;
  		} else
  			scsi_result = device_qfull_result;
  	} else if (unlikely(sdebug_every_nth &&
  			    (SDEBUG_OPT_RARE_TSF & sdebug_opts) &&
  			    (scsi_result == 0))) {
  		if ((num_in_q == (qdepth - 1)) &&
  		    (atomic_inc_return(&sdebug_a_tsf) >=
  		     abs(sdebug_every_nth))) {
  			atomic_set(&sdebug_a_tsf, 0);
  			inject = 1;
  			scsi_result = device_qfull_result;
  		}
  	}
  
  	k = find_first_zero_bit(sqp->in_use_bm, sdebug_max_queue);
  	if (unlikely(k >= sdebug_max_queue)) {
  		spin_unlock_irqrestore(&sqp->qc_lock, iflags);
  		if (scsi_result)
  			goto respond_in_thread;
  		else if (SDEBUG_OPT_ALL_TSF & sdebug_opts)
  			scsi_result = device_qfull_result;
  		if (SDEBUG_OPT_Q_NOISE & sdebug_opts)
  			sdev_printk(KERN_INFO, sdp,
  				    "%s: max_queue=%d exceeded, %s\n",
  				    __func__, sdebug_max_queue,
  				    (scsi_result ?  "status: TASK SET FULL" :
  						    "report: host busy"));
  		if (scsi_result)
  			goto respond_in_thread;
  		else
  			return SCSI_MLQUEUE_HOST_BUSY;
  	}
  	__set_bit(k, sqp->in_use_bm);
  	atomic_inc(&devip->num_in_q);
  	sqcp = &sqp->qc_arr[k];
  	sqcp->a_cmnd = cmnd;
  	cmnd->host_scribble = (unsigned char *)sqcp;
  	sd_dp = sqcp->sd_dp;
  	spin_unlock_irqrestore(&sqp->qc_lock, iflags);
  	if (unlikely(sdebug_every_nth && sdebug_any_injecting_opt))
  		setup_inject(sqp, sqcp);
  	if (sd_dp == NULL) {
  		sd_dp = kzalloc(sizeof(*sd_dp), GFP_ATOMIC);
  		if (sd_dp == NULL)
  			return SCSI_MLQUEUE_HOST_BUSY;
  	}
  
  	cmnd->result = pfp != NULL ? pfp(cmnd, devip) : 0;
  	if (cmnd->result & SDEG_RES_IMMED_MASK) {
  		/*
  		 * This is the F_DELAY_OVERR case. No delay.
  		 */
  		cmnd->result &= ~SDEG_RES_IMMED_MASK;
  		delta_jiff = ndelay = 0;
  	}
  	if (cmnd->result == 0 && scsi_result != 0)
  		cmnd->result = scsi_result;
  
  	if (unlikely(sdebug_verbose && cmnd->result))
  		sdev_printk(KERN_INFO, sdp, "%s: non-zero result=0x%x\n",
  			    __func__, cmnd->result);
  
  	if (delta_jiff > 0 || ndelay > 0) {
  		ktime_t kt;
  
  		if (delta_jiff > 0) {
  			kt = ns_to_ktime((u64)delta_jiff * (NSEC_PER_SEC / HZ));
  		} else
  			kt = ndelay;
  		if (!sd_dp->init_hrt) {
  			sd_dp->init_hrt = true;
  			sqcp->sd_dp = sd_dp;
  			hrtimer_init(&sd_dp->hrt, CLOCK_MONOTONIC,
  				     HRTIMER_MODE_REL_PINNED);
  			sd_dp->hrt.function = sdebug_q_cmd_hrt_complete;
  			sd_dp->sqa_idx = sqp - sdebug_q_arr;
  			sd_dp->qc_idx = k;
  		}
  		if (sdebug_statistics)
  			sd_dp->issuing_cpu = raw_smp_processor_id();
  		sd_dp->defer_t = SDEB_DEFER_HRT;
  		hrtimer_start(&sd_dp->hrt, kt, HRTIMER_MODE_REL_PINNED);
  	} else {	/* jdelay < 0, use work queue */
  		if (!sd_dp->init_wq) {
  			sd_dp->init_wq = true;
  			sqcp->sd_dp = sd_dp;
  			sd_dp->sqa_idx = sqp - sdebug_q_arr;
  			sd_dp->qc_idx = k;
  			INIT_WORK(&sd_dp->ew.work, sdebug_q_cmd_wq_complete);
  		}
  		if (sdebug_statistics)
  			sd_dp->issuing_cpu = raw_smp_processor_id();
  		sd_dp->defer_t = SDEB_DEFER_WQ;
  		if (unlikely(sqcp->inj_cmd_abort))
  			sd_dp->aborted = true;
  		schedule_work(&sd_dp->ew.work);
  		if (unlikely(sqcp->inj_cmd_abort)) {
  			sdev_printk(KERN_INFO, sdp, "abort request tag %d\n",
  				    cmnd->request->tag);
  			blk_abort_request(cmnd->request);
  		}
  	}
  	if (unlikely((SDEBUG_OPT_Q_NOISE & sdebug_opts) &&
  		     (scsi_result == device_qfull_result)))
  		sdev_printk(KERN_INFO, sdp,
  			    "%s: num_in_q=%d +1, %s%s\n", __func__,
  			    num_in_q, (inject ? "<inject> " : ""),
  			    "status: TASK SET FULL");
  	return 0;
  
  respond_in_thread:	/* call back to mid-layer using invocation thread */
  	cmnd->result = pfp != NULL ? pfp(cmnd, devip) : 0;
  	cmnd->result &= ~SDEG_RES_IMMED_MASK;
  	if (cmnd->result == 0 && scsi_result != 0)
  		cmnd->result = scsi_result;
  	cmnd->scsi_done(cmnd);
  	return 0;
  }
  
  /* Note: The following macros create attribute files in the
     /sys/module/scsi_debug/parameters directory. Unfortunately this
     driver is unaware of a change and cannot trigger auxiliary actions
     as it can when the corresponding attribute in the
     /sys/bus/pseudo/drivers/scsi_debug directory is changed.
   */
  module_param_named(add_host, sdebug_add_host, int, S_IRUGO | S_IWUSR);
  module_param_named(ato, sdebug_ato, int, S_IRUGO);
  module_param_named(cdb_len, sdebug_cdb_len, int, 0644);
  module_param_named(clustering, sdebug_clustering, bool, S_IRUGO | S_IWUSR);
  module_param_named(delay, sdebug_jdelay, int, S_IRUGO | S_IWUSR);
  module_param_named(dev_size_mb, sdebug_dev_size_mb, int, S_IRUGO);
  module_param_named(dif, sdebug_dif, int, S_IRUGO);
  module_param_named(dix, sdebug_dix, int, S_IRUGO);
  module_param_named(dsense, sdebug_dsense, int, S_IRUGO | S_IWUSR);
  module_param_named(every_nth, sdebug_every_nth, int, S_IRUGO | S_IWUSR);
  module_param_named(fake_rw, sdebug_fake_rw, int, S_IRUGO | S_IWUSR);
  module_param_named(guard, sdebug_guard, uint, S_IRUGO);
  module_param_named(host_lock, sdebug_host_lock, bool, S_IRUGO | S_IWUSR);
  module_param_string(inq_vendor, sdebug_inq_vendor_id,
  		    sizeof(sdebug_inq_vendor_id), S_IRUGO|S_IWUSR);
  module_param_string(inq_product, sdebug_inq_product_id,
  		    sizeof(sdebug_inq_product_id), S_IRUGO|S_IWUSR);
  module_param_string(inq_rev, sdebug_inq_product_rev,
  		    sizeof(sdebug_inq_product_rev), S_IRUGO|S_IWUSR);
  module_param_named(lbpu, sdebug_lbpu, int, S_IRUGO);
  module_param_named(lbpws, sdebug_lbpws, int, S_IRUGO);
  module_param_named(lbpws10, sdebug_lbpws10, int, S_IRUGO);
  module_param_named(lbprz, sdebug_lbprz, int, S_IRUGO);
  module_param_named(lowest_aligned, sdebug_lowest_aligned, int, S_IRUGO);
  module_param_named(max_luns, sdebug_max_luns, int, S_IRUGO | S_IWUSR);
  module_param_named(max_queue, sdebug_max_queue, int, S_IRUGO | S_IWUSR);
  module_param_named(medium_error_start, sdebug_medium_error_start, int, S_IRUGO | S_IWUSR);
  module_param_named(medium_error_count, sdebug_medium_error_count, int, S_IRUGO | S_IWUSR);
  module_param_named(ndelay, sdebug_ndelay, int, S_IRUGO | S_IWUSR);
  module_param_named(no_lun_0, sdebug_no_lun_0, int, S_IRUGO | S_IWUSR);
  module_param_named(no_uld, sdebug_no_uld, int, S_IRUGO);
  module_param_named(num_parts, sdebug_num_parts, int, S_IRUGO);
  module_param_named(num_tgts, sdebug_num_tgts, int, S_IRUGO | S_IWUSR);
  module_param_named(opt_blks, sdebug_opt_blks, int, S_IRUGO);
  module_param_named(opts, sdebug_opts, int, S_IRUGO | S_IWUSR);
  module_param_named(physblk_exp, sdebug_physblk_exp, int, S_IRUGO);
  module_param_named(opt_xferlen_exp, sdebug_opt_xferlen_exp, int, S_IRUGO);
  module_param_named(ptype, sdebug_ptype, int, S_IRUGO | S_IWUSR);
  module_param_named(removable, sdebug_removable, bool, S_IRUGO | S_IWUSR);
  module_param_named(scsi_level, sdebug_scsi_level, int, S_IRUGO);
  module_param_named(sector_size, sdebug_sector_size, int, S_IRUGO);
  module_param_named(statistics, sdebug_statistics, bool, S_IRUGO | S_IWUSR);
  module_param_named(strict, sdebug_strict, bool, S_IRUGO | S_IWUSR);
  module_param_named(submit_queues, submit_queues, int, S_IRUGO);
  module_param_named(unmap_alignment, sdebug_unmap_alignment, int, S_IRUGO);
  module_param_named(unmap_granularity, sdebug_unmap_granularity, int, S_IRUGO);
  module_param_named(unmap_max_blocks, sdebug_unmap_max_blocks, int, S_IRUGO);
  module_param_named(unmap_max_desc, sdebug_unmap_max_desc, int, S_IRUGO);
  module_param_named(virtual_gb, sdebug_virtual_gb, int, S_IRUGO | S_IWUSR);
  module_param_named(uuid_ctl, sdebug_uuid_ctl, int, S_IRUGO);
  module_param_named(vpd_use_hostno, sdebug_vpd_use_hostno, int,
  		   S_IRUGO | S_IWUSR);
  module_param_named(wp, sdebug_wp, bool, S_IRUGO | S_IWUSR);
  module_param_named(write_same_length, sdebug_write_same_length, int,
  		   S_IRUGO | S_IWUSR);
  
  MODULE_AUTHOR("Eric Youngdale + Douglas Gilbert");
  MODULE_DESCRIPTION("SCSI debug adapter driver");
  MODULE_LICENSE("GPL");
  MODULE_VERSION(SDEBUG_VERSION);
  
  MODULE_PARM_DESC(add_host, "0..127 hosts allowed(def=1)");
  MODULE_PARM_DESC(ato, "application tag ownership: 0=disk 1=host (def=1)");
  MODULE_PARM_DESC(cdb_len, "suggest CDB lengths to drivers (def=10)");
  MODULE_PARM_DESC(clustering, "when set enables larger transfers (def=0)");
  MODULE_PARM_DESC(delay, "response delay (def=1 jiffy); 0:imm, -1,-2:tiny");
  MODULE_PARM_DESC(dev_size_mb, "size in MiB of ram shared by devs(def=8)");
  MODULE_PARM_DESC(dif, "data integrity field type: 0-3 (def=0)");
  MODULE_PARM_DESC(dix, "data integrity extensions mask (def=0)");
  MODULE_PARM_DESC(dsense, "use descriptor sense format(def=0 -> fixed)");
  MODULE_PARM_DESC(every_nth, "timeout every nth command(def=0)");
  MODULE_PARM_DESC(fake_rw, "fake reads/writes instead of copying (def=0)");
  MODULE_PARM_DESC(guard, "protection checksum: 0=crc, 1=ip (def=0)");
  MODULE_PARM_DESC(host_lock, "host_lock is ignored (def=0)");
  MODULE_PARM_DESC(inq_vendor, "SCSI INQUIRY vendor string (def=\"Linux\")");
  MODULE_PARM_DESC(inq_product, "SCSI INQUIRY product string (def=\"scsi_debug\")");
  MODULE_PARM_DESC(inq_rev, "SCSI INQUIRY revision string (def=\""
  		 SDEBUG_VERSION "\")");
  MODULE_PARM_DESC(lbpu, "enable LBP, support UNMAP command (def=0)");
  MODULE_PARM_DESC(lbpws, "enable LBP, support WRITE SAME(16) with UNMAP bit (def=0)");
  MODULE_PARM_DESC(lbpws10, "enable LBP, support WRITE SAME(10) with UNMAP bit (def=0)");
  MODULE_PARM_DESC(lbprz,
  	"on read unmapped LBs return 0 when 1 (def), return 0xff when 2");
  MODULE_PARM_DESC(lowest_aligned, "lowest aligned lba (def=0)");
  MODULE_PARM_DESC(max_luns, "number of LUNs per target to simulate(def=1)");
  MODULE_PARM_DESC(max_queue, "max number of queued commands (1 to max(def))");
  MODULE_PARM_DESC(medium_error_start, "starting sector number to return MEDIUM error");
  MODULE_PARM_DESC(medium_error_count, "count of sectors to return follow on MEDIUM error");
  MODULE_PARM_DESC(ndelay, "response delay in nanoseconds (def=0 -> ignore)");
  MODULE_PARM_DESC(no_lun_0, "no LU number 0 (def=0 -> have lun 0)");
  MODULE_PARM_DESC(no_uld, "stop ULD (e.g. sd driver) attaching (def=0))");
  MODULE_PARM_DESC(num_parts, "number of partitions(def=0)");
  MODULE_PARM_DESC(num_tgts, "number of targets per host to simulate(def=1)");
  MODULE_PARM_DESC(opt_blks, "optimal transfer length in blocks (def=1024)");
  MODULE_PARM_DESC(opts, "1->noise, 2->medium_err, 4->timeout, 8->recovered_err... (def=0)");
  MODULE_PARM_DESC(physblk_exp, "physical block exponent (def=0)");
  MODULE_PARM_DESC(opt_xferlen_exp, "optimal transfer length granularity exponent (def=physblk_exp)");
  MODULE_PARM_DESC(ptype, "SCSI peripheral type(def=0[disk])");
  MODULE_PARM_DESC(removable, "claim to have removable media (def=0)");
  MODULE_PARM_DESC(scsi_level, "SCSI level to simulate(def=7[SPC-5])");
  MODULE_PARM_DESC(sector_size, "logical block size in bytes (def=512)");
  MODULE_PARM_DESC(statistics, "collect statistics on commands, queues (def=0)");
  MODULE_PARM_DESC(strict, "stricter checks: reserved field in cdb (def=0)");
  MODULE_PARM_DESC(submit_queues, "support for block multi-queue (def=1)");
  MODULE_PARM_DESC(unmap_alignment, "lowest aligned thin provisioning lba (def=0)");
  MODULE_PARM_DESC(unmap_granularity, "thin provisioning granularity in blocks (def=1)");
  MODULE_PARM_DESC(unmap_max_blocks, "max # of blocks can be unmapped in one cmd (def=0xffffffff)");
  MODULE_PARM_DESC(unmap_max_desc, "max # of ranges that can be unmapped in one cmd (def=256)");
  MODULE_PARM_DESC(uuid_ctl,
  		 "1->use uuid for lu name, 0->don't, 2->all use same (def=0)");
  MODULE_PARM_DESC(virtual_gb, "virtual gigabyte (GiB) size (def=0 -> use dev_size_mb)");
  MODULE_PARM_DESC(vpd_use_hostno, "0 -> dev ids ignore hostno (def=1 -> unique dev ids)");
  MODULE_PARM_DESC(wp, "Write Protect (def=0)");
  MODULE_PARM_DESC(write_same_length, "Maximum blocks per WRITE SAME cmd (def=0xffff)");
  
  #define SDEBUG_INFO_LEN 256
  static char sdebug_info[SDEBUG_INFO_LEN];
  
  static const char *scsi_debug_info(struct Scsi_Host *shp)
  {
  	int k;
  
  	k = scnprintf(sdebug_info, SDEBUG_INFO_LEN, "%s: version %s [%s]\n",
  		      my_name, SDEBUG_VERSION, sdebug_version_date);
  	if (k >= (SDEBUG_INFO_LEN - 1))
  		return sdebug_info;
  	scnprintf(sdebug_info + k, SDEBUG_INFO_LEN - k,
  		  "  dev_size_mb=%d, opts=0x%x, submit_queues=%d, %s=%d",
  		  sdebug_dev_size_mb, sdebug_opts, submit_queues,
  		  "statistics", (int)sdebug_statistics);
  	return sdebug_info;
  }
  
  /* 'echo <val> > /proc/scsi/scsi_debug/<host_id>' writes to opts */
  static int scsi_debug_write_info(struct Scsi_Host *host, char *buffer,
  				 int length)
  {
  	char arr[16];
  	int opts;
  	int minLen = length > 15 ? 15 : length;
  
  	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
  		return -EACCES;
  	memcpy(arr, buffer, minLen);
  	arr[minLen] = '\0';
  	if (1 != sscanf(arr, "%d", &opts))
  		return -EINVAL;
  	sdebug_opts = opts;
  	sdebug_verbose = !!(SDEBUG_OPT_NOISE & opts);
  	sdebug_any_injecting_opt = !!(SDEBUG_OPT_ALL_INJECTING & opts);
  	if (sdebug_every_nth != 0)
  		tweak_cmnd_count();
  	return length;
  }
  
  /* Output seen with 'cat /proc/scsi/scsi_debug/<host_id>'. It will be the
   * same for each scsi_debug host (if more than one). Some of the counters
   * output are not atomics so might be inaccurate in a busy system. */
  static int scsi_debug_show_info(struct seq_file *m, struct Scsi_Host *host)
  {
  	int f, j, l;
  	struct sdebug_queue *sqp;
  
  	seq_printf(m, "scsi_debug adapter driver, version %s [%s]\n",
  		   SDEBUG_VERSION, sdebug_version_date);
  	seq_printf(m, "num_tgts=%d, %ssize=%d MB, opts=0x%x, every_nth=%d\n",
  		   sdebug_num_tgts, "shared (ram) ", sdebug_dev_size_mb,
  		   sdebug_opts, sdebug_every_nth);
  	seq_printf(m, "delay=%d, ndelay=%d, max_luns=%d, sector_size=%d %s\n",
  		   sdebug_jdelay, sdebug_ndelay, sdebug_max_luns,
  		   sdebug_sector_size, "bytes");
  	seq_printf(m, "cylinders=%d, heads=%d, sectors=%d, command aborts=%d\n",
  		   sdebug_cylinders_per, sdebug_heads, sdebug_sectors_per,
  		   num_aborts);
  	seq_printf(m, "RESETs: device=%d, target=%d, bus=%d, host=%d\n",
  		   num_dev_resets, num_target_resets, num_bus_resets,
  		   num_host_resets);
  	seq_printf(m, "dix_reads=%d, dix_writes=%d, dif_errors=%d\n",
  		   dix_reads, dix_writes, dif_errors);
  	seq_printf(m, "usec_in_jiffy=%lu, statistics=%d\n", TICK_NSEC / 1000,
  		   sdebug_statistics);
  	seq_printf(m, "cmnd_count=%d, completions=%d, %s=%d, a_tsf=%d\n",
  		   atomic_read(&sdebug_cmnd_count),
  		   atomic_read(&sdebug_completions),
  		   "miss_cpus", atomic_read(&sdebug_miss_cpus),
  		   atomic_read(&sdebug_a_tsf));
  
  	seq_printf(m, "submit_queues=%d\n", submit_queues);
  	for (j = 0, sqp = sdebug_q_arr; j < submit_queues; ++j, ++sqp) {
  		seq_printf(m, "  queue %d:\n", j);
  		f = find_first_bit(sqp->in_use_bm, sdebug_max_queue);
  		if (f != sdebug_max_queue) {
  			l = find_last_bit(sqp->in_use_bm, sdebug_max_queue);
  			seq_printf(m, "    in_use_bm BUSY: %s: %d,%d\n",
  				   "first,last bits", f, l);
  		}
  	}
  	return 0;
  }
  
  static ssize_t delay_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_jdelay);
  }
  /* Returns -EBUSY if jdelay is being changed and commands are queued. The unit
   * of delay is jiffies.
   */
  static ssize_t delay_store(struct device_driver *ddp, const char *buf,
  			   size_t count)
  {
  	int jdelay, res;
  
  	if (count > 0 && sscanf(buf, "%d", &jdelay) == 1) {
  		res = count;
  		if (sdebug_jdelay != jdelay) {
  			int j, k;
  			struct sdebug_queue *sqp;
  
  			block_unblock_all_queues(true);
  			for (j = 0, sqp = sdebug_q_arr; j < submit_queues;
  			     ++j, ++sqp) {
  				k = find_first_bit(sqp->in_use_bm,
  						   sdebug_max_queue);
  				if (k != sdebug_max_queue) {
  					res = -EBUSY;   /* queued commands */
  					break;
  				}
  			}
  			if (res > 0) {
  				sdebug_jdelay = jdelay;
  				sdebug_ndelay = 0;
  			}
  			block_unblock_all_queues(false);
  		}
  		return res;
  	}
  	return -EINVAL;
  }
  static DRIVER_ATTR_RW(delay);
  
  static ssize_t ndelay_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_ndelay);
  }
  /* Returns -EBUSY if ndelay is being changed and commands are queued */
  /* If > 0 and accepted then sdebug_jdelay is set to JDELAY_OVERRIDDEN */
  static ssize_t ndelay_store(struct device_driver *ddp, const char *buf,
  			    size_t count)
  {
  	int ndelay, res;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &ndelay)) &&
  	    (ndelay >= 0) && (ndelay < (1000 * 1000 * 1000))) {
  		res = count;
  		if (sdebug_ndelay != ndelay) {
  			int j, k;
  			struct sdebug_queue *sqp;
  
  			block_unblock_all_queues(true);
  			for (j = 0, sqp = sdebug_q_arr; j < submit_queues;
  			     ++j, ++sqp) {
  				k = find_first_bit(sqp->in_use_bm,
  						   sdebug_max_queue);
  				if (k != sdebug_max_queue) {
  					res = -EBUSY;   /* queued commands */
  					break;
  				}
  			}
  			if (res > 0) {
  				sdebug_ndelay = ndelay;
  				sdebug_jdelay = ndelay  ? JDELAY_OVERRIDDEN
  							: DEF_JDELAY;
  			}
  			block_unblock_all_queues(false);
  		}
  		return res;
  	}
  	return -EINVAL;
  }
  static DRIVER_ATTR_RW(ndelay);
  
  static ssize_t opts_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "0x%x\n", sdebug_opts);
  }
  
  static ssize_t opts_store(struct device_driver *ddp, const char *buf,
  			  size_t count)
  {
  	int opts;
  	char work[20];
  
  	if (sscanf(buf, "%10s", work) == 1) {
  		if (strncasecmp(work, "0x", 2) == 0) {
  			if (kstrtoint(work + 2, 16, &opts) == 0)
  				goto opts_done;
  		} else {
  			if (kstrtoint(work, 10, &opts) == 0)
  				goto opts_done;
  		}
  	}
  	return -EINVAL;
  opts_done:
  	sdebug_opts = opts;
  	sdebug_verbose = !!(SDEBUG_OPT_NOISE & opts);
  	sdebug_any_injecting_opt = !!(SDEBUG_OPT_ALL_INJECTING & opts);
  	tweak_cmnd_count();
  	return count;
  }
  static DRIVER_ATTR_RW(opts);
  
  static ssize_t ptype_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_ptype);
  }
  static ssize_t ptype_store(struct device_driver *ddp, const char *buf,
  			   size_t count)
  {
  	int n;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
  		sdebug_ptype = n;
  		return count;
  	}
  	return -EINVAL;
  }
  static DRIVER_ATTR_RW(ptype);
  
  static ssize_t dsense_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_dsense);
  }
  static ssize_t dsense_store(struct device_driver *ddp, const char *buf,
  			    size_t count)
  {
  	int n;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
  		sdebug_dsense = n;
  		return count;
  	}
  	return -EINVAL;
  }
  static DRIVER_ATTR_RW(dsense);
  
  static ssize_t fake_rw_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_fake_rw);
  }
  static ssize_t fake_rw_store(struct device_driver *ddp, const char *buf,
  			     size_t count)
  {
  	int n;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
  		n = (n > 0);
  		sdebug_fake_rw = (sdebug_fake_rw > 0);
  		if (sdebug_fake_rw != n) {
  			if ((0 == n) && (NULL == fake_storep)) {
  				unsigned long sz =
  					(unsigned long)sdebug_dev_size_mb *
  					1048576;
  
  				fake_storep = vzalloc(sz);
  				if (NULL == fake_storep) {
  					pr_err("out of memory, 9\n");
  					return -ENOMEM;
  				}
  			}
  			sdebug_fake_rw = n;
  		}
  		return count;
  	}
  	return -EINVAL;
  }
  static DRIVER_ATTR_RW(fake_rw);
  
  static ssize_t no_lun_0_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_no_lun_0);
  }
  static ssize_t no_lun_0_store(struct device_driver *ddp, const char *buf,
  			      size_t count)
  {
  	int n;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
  		sdebug_no_lun_0 = n;
  		return count;
  	}
  	return -EINVAL;
  }
  static DRIVER_ATTR_RW(no_lun_0);
  
  static ssize_t num_tgts_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_num_tgts);
  }
  static ssize_t num_tgts_store(struct device_driver *ddp, const char *buf,
  			      size_t count)
  {
  	int n;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
  		sdebug_num_tgts = n;
  		sdebug_max_tgts_luns();
  		return count;
  	}
  	return -EINVAL;
  }
  static DRIVER_ATTR_RW(num_tgts);
  
  static ssize_t dev_size_mb_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_dev_size_mb);
  }
  static DRIVER_ATTR_RO(dev_size_mb);
  
  static ssize_t num_parts_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_num_parts);
  }
  static DRIVER_ATTR_RO(num_parts);
  
  static ssize_t every_nth_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_every_nth);
  }
  static ssize_t every_nth_store(struct device_driver *ddp, const char *buf,
  			       size_t count)
  {
  	int nth;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &nth))) {
  		sdebug_every_nth = nth;
  		if (nth && !sdebug_statistics) {
  			pr_info("every_nth needs statistics=1, set it\n");
  			sdebug_statistics = true;
  		}
  		tweak_cmnd_count();
  		return count;
  	}
  	return -EINVAL;
  }
  static DRIVER_ATTR_RW(every_nth);
  
  static ssize_t max_luns_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_max_luns);
  }
  static ssize_t max_luns_store(struct device_driver *ddp, const char *buf,
  			      size_t count)
  {
  	int n;
  	bool changed;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
  		if (n > 256) {
  			pr_warn("max_luns can be no more than 256\n");
  			return -EINVAL;
  		}
  		changed = (sdebug_max_luns != n);
  		sdebug_max_luns = n;
  		sdebug_max_tgts_luns();
  		if (changed && (sdebug_scsi_level >= 5)) {	/* >= SPC-3 */
  			struct sdebug_host_info *sdhp;
  			struct sdebug_dev_info *dp;
  
  			spin_lock(&sdebug_host_list_lock);
  			list_for_each_entry(sdhp, &sdebug_host_list,
  					    host_list) {
  				list_for_each_entry(dp, &sdhp->dev_info_list,
  						    dev_list) {
  					set_bit(SDEBUG_UA_LUNS_CHANGED,
  						dp->uas_bm);
  				}
  			}
  			spin_unlock(&sdebug_host_list_lock);
  		}
  		return count;
  	}
  	return -EINVAL;
  }
  static DRIVER_ATTR_RW(max_luns);
  
  static ssize_t max_queue_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_max_queue);
  }
  /* N.B. max_queue can be changed while there are queued commands. In flight
   * commands beyond the new max_queue will be completed. */
  static ssize_t max_queue_store(struct device_driver *ddp, const char *buf,
  			       size_t count)
  {
  	int j, n, k, a;
  	struct sdebug_queue *sqp;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n > 0) &&
  	    (n <= SDEBUG_CANQUEUE)) {
  		block_unblock_all_queues(true);
  		k = 0;
  		for (j = 0, sqp = sdebug_q_arr; j < submit_queues;
  		     ++j, ++sqp) {
  			a = find_last_bit(sqp->in_use_bm, SDEBUG_CANQUEUE);
  			if (a > k)
  				k = a;
  		}
  		sdebug_max_queue = n;
  		if (k == SDEBUG_CANQUEUE)
  			atomic_set(&retired_max_queue, 0);
  		else if (k >= n)
  			atomic_set(&retired_max_queue, k + 1);
  		else
  			atomic_set(&retired_max_queue, 0);
  		block_unblock_all_queues(false);
  		return count;
  	}
  	return -EINVAL;
  }
  static DRIVER_ATTR_RW(max_queue);
  
  static ssize_t no_uld_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_no_uld);
  }
  static DRIVER_ATTR_RO(no_uld);
  
  static ssize_t scsi_level_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_scsi_level);
  }
  static DRIVER_ATTR_RO(scsi_level);
  
  static ssize_t virtual_gb_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_virtual_gb);
  }
  static ssize_t virtual_gb_store(struct device_driver *ddp, const char *buf,
  				size_t count)
  {
  	int n;
  	bool changed;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
  		changed = (sdebug_virtual_gb != n);
  		sdebug_virtual_gb = n;
  		sdebug_capacity = get_sdebug_capacity();
  		if (changed) {
  			struct sdebug_host_info *sdhp;
  			struct sdebug_dev_info *dp;
  
  			spin_lock(&sdebug_host_list_lock);
  			list_for_each_entry(sdhp, &sdebug_host_list,
  					    host_list) {
  				list_for_each_entry(dp, &sdhp->dev_info_list,
  						    dev_list) {
  					set_bit(SDEBUG_UA_CAPACITY_CHANGED,
  						dp->uas_bm);
  				}
  			}
  			spin_unlock(&sdebug_host_list_lock);
  		}
  		return count;
  	}
  	return -EINVAL;
  }
  static DRIVER_ATTR_RW(virtual_gb);
  
  static ssize_t add_host_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_add_host);
  }
  
  static int sdebug_add_adapter(void);
  static void sdebug_remove_adapter(void);
  
  static ssize_t add_host_store(struct device_driver *ddp, const char *buf,
  			      size_t count)
  {
  	int delta_hosts;
  
  	if (sscanf(buf, "%d", &delta_hosts) != 1)
  		return -EINVAL;
  	if (delta_hosts > 0) {
  		do {
  			sdebug_add_adapter();
  		} while (--delta_hosts);
  	} else if (delta_hosts < 0) {
  		do {
  			sdebug_remove_adapter();
  		} while (++delta_hosts);
  	}
  	return count;
  }
  static DRIVER_ATTR_RW(add_host);
  
  static ssize_t vpd_use_hostno_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_vpd_use_hostno);
  }
  static ssize_t vpd_use_hostno_store(struct device_driver *ddp, const char *buf,
  				    size_t count)
  {
  	int n;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
  		sdebug_vpd_use_hostno = n;
  		return count;
  	}
  	return -EINVAL;
  }
  static DRIVER_ATTR_RW(vpd_use_hostno);
  
  static ssize_t statistics_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", (int)sdebug_statistics);
  }
  static ssize_t statistics_store(struct device_driver *ddp, const char *buf,
  				size_t count)
  {
  	int n;
  
  	if ((count > 0) && (sscanf(buf, "%d", &n) == 1) && (n >= 0)) {
  		if (n > 0)
  			sdebug_statistics = true;
  		else {
  			clear_queue_stats();
  			sdebug_statistics = false;
  		}
  		return count;
  	}
  	return -EINVAL;
  }
  static DRIVER_ATTR_RW(statistics);
  
  static ssize_t sector_size_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%u\n", sdebug_sector_size);
  }
  static DRIVER_ATTR_RO(sector_size);
  
  static ssize_t submit_queues_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", submit_queues);
  }
  static DRIVER_ATTR_RO(submit_queues);
  
  static ssize_t dix_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_dix);
  }
  static DRIVER_ATTR_RO(dix);
  
  static ssize_t dif_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_dif);
  }
  static DRIVER_ATTR_RO(dif);
  
  static ssize_t guard_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%u\n", sdebug_guard);
  }
  static DRIVER_ATTR_RO(guard);
  
  static ssize_t ato_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_ato);
  }
  static DRIVER_ATTR_RO(ato);
  
  static ssize_t map_show(struct device_driver *ddp, char *buf)
  {
  	ssize_t count;
  
  	if (!scsi_debug_lbp())
  		return scnprintf(buf, PAGE_SIZE, "0-%u\n",
  				 sdebug_store_sectors);
  
  	count = scnprintf(buf, PAGE_SIZE - 1, "%*pbl",
  			  (int)map_size, map_storep);
  	buf[count++] = '\n';
  	buf[count] = '\0';
  
  	return count;
  }
  static DRIVER_ATTR_RO(map);
  
  static ssize_t removable_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_removable ? 1 : 0);
  }
  static ssize_t removable_store(struct device_driver *ddp, const char *buf,
  			       size_t count)
  {
  	int n;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
  		sdebug_removable = (n > 0);
  		return count;
  	}
  	return -EINVAL;
  }
  static DRIVER_ATTR_RW(removable);
  
  static ssize_t host_lock_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", !!sdebug_host_lock);
  }
  /* N.B. sdebug_host_lock does nothing, kept for backward compatibility */
  static ssize_t host_lock_store(struct device_driver *ddp, const char *buf,
  			       size_t count)
  {
  	int n;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
  		sdebug_host_lock = (n > 0);
  		return count;
  	}
  	return -EINVAL;
  }
  static DRIVER_ATTR_RW(host_lock);
  
  static ssize_t strict_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", !!sdebug_strict);
  }
  static ssize_t strict_store(struct device_driver *ddp, const char *buf,
  			    size_t count)
  {
  	int n;
  
  	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
  		sdebug_strict = (n > 0);
  		return count;
  	}
  	return -EINVAL;
  }
  static DRIVER_ATTR_RW(strict);
  
  static ssize_t uuid_ctl_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", !!sdebug_uuid_ctl);
  }
  static DRIVER_ATTR_RO(uuid_ctl);
  
  static ssize_t cdb_len_show(struct device_driver *ddp, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_cdb_len);
  }
  static ssize_t cdb_len_store(struct device_driver *ddp, const char *buf,
  			     size_t count)
  {
  	int ret, n;
  
  	ret = kstrtoint(buf, 0, &n);
  	if (ret)
  		return ret;
  	sdebug_cdb_len = n;
  	all_config_cdb_len();
  	return count;
  }
  static DRIVER_ATTR_RW(cdb_len);
  
  
  /* Note: The following array creates attribute files in the
     /sys/bus/pseudo/drivers/scsi_debug directory. The advantage of these
     files (over those found in the /sys/module/scsi_debug/parameters
     directory) is that auxiliary actions can be triggered when an attribute
     is changed. For example see: sdebug_add_host_store() above.
   */
  
  static struct attribute *sdebug_drv_attrs[] = {
  	&driver_attr_delay.attr,
  	&driver_attr_opts.attr,
  	&driver_attr_ptype.attr,
  	&driver_attr_dsense.attr,
  	&driver_attr_fake_rw.attr,
  	&driver_attr_no_lun_0.attr,
  	&driver_attr_num_tgts.attr,
  	&driver_attr_dev_size_mb.attr,
  	&driver_attr_num_parts.attr,
  	&driver_attr_every_nth.attr,
  	&driver_attr_max_luns.attr,
  	&driver_attr_max_queue.attr,
  	&driver_attr_no_uld.attr,
  	&driver_attr_scsi_level.attr,
  	&driver_attr_virtual_gb.attr,
  	&driver_attr_add_host.attr,
  	&driver_attr_vpd_use_hostno.attr,
  	&driver_attr_sector_size.attr,
  	&driver_attr_statistics.attr,
  	&driver_attr_submit_queues.attr,
  	&driver_attr_dix.attr,
  	&driver_attr_dif.attr,
  	&driver_attr_guard.attr,
  	&driver_attr_ato.attr,
  	&driver_attr_map.attr,
  	&driver_attr_removable.attr,
  	&driver_attr_host_lock.attr,
  	&driver_attr_ndelay.attr,
  	&driver_attr_strict.attr,
  	&driver_attr_uuid_ctl.attr,
  	&driver_attr_cdb_len.attr,
  	NULL,
  };
  ATTRIBUTE_GROUPS(sdebug_drv);
  
  static struct device *pseudo_primary;
  
  static int __init scsi_debug_init(void)
  {
  	unsigned long sz;
  	int host_to_add;
  	int k;
  	int ret;
  
  	atomic_set(&retired_max_queue, 0);
  
  	if (sdebug_ndelay >= 1000 * 1000 * 1000) {
  		pr_warn("ndelay must be less than 1 second, ignored\n");
  		sdebug_ndelay = 0;
  	} else if (sdebug_ndelay > 0)
  		sdebug_jdelay = JDELAY_OVERRIDDEN;
  
  	switch (sdebug_sector_size) {
  	case  512:
  	case 1024:
  	case 2048:
  	case 4096:
  		break;
  	default:
  		pr_err("invalid sector_size %d\n", sdebug_sector_size);
  		return -EINVAL;
  	}
  
  	switch (sdebug_dif) {
  	case T10_PI_TYPE0_PROTECTION:
  		break;
  	case T10_PI_TYPE1_PROTECTION:
  	case T10_PI_TYPE2_PROTECTION:
  	case T10_PI_TYPE3_PROTECTION:
  		have_dif_prot = true;
  		break;
  
  	default:
  		pr_err("dif must be 0, 1, 2 or 3\n");
  		return -EINVAL;
  	}
  
  	if (sdebug_num_tgts < 0) {
  		pr_err("num_tgts must be >= 0\n");
  		return -EINVAL;
  	}
  
  	if (sdebug_guard > 1) {
  		pr_err("guard must be 0 or 1\n");
  		return -EINVAL;
  	}
  
  	if (sdebug_ato > 1) {
  		pr_err("ato must be 0 or 1\n");
  		return -EINVAL;
  	}
  
  	if (sdebug_physblk_exp > 15) {
  		pr_err("invalid physblk_exp %u\n", sdebug_physblk_exp);
  		return -EINVAL;
  	}
  	if (sdebug_max_luns > 256) {
  		pr_warn("max_luns can be no more than 256, use default\n");
  		sdebug_max_luns = DEF_MAX_LUNS;
  	}
  
  	if (sdebug_lowest_aligned > 0x3fff) {
  		pr_err("lowest_aligned too big: %u\n", sdebug_lowest_aligned);
  		return -EINVAL;
  	}
  
  	if (submit_queues < 1) {
  		pr_err("submit_queues must be 1 or more\n");
  		return -EINVAL;
  	}
  	sdebug_q_arr = kcalloc(submit_queues, sizeof(struct sdebug_queue),
  			       GFP_KERNEL);
  	if (sdebug_q_arr == NULL)
  		return -ENOMEM;
  	for (k = 0; k < submit_queues; ++k)
  		spin_lock_init(&sdebug_q_arr[k].qc_lock);
  
  	if (sdebug_dev_size_mb < 1)
  		sdebug_dev_size_mb = 1;  /* force minimum 1 MB ramdisk */
  	sz = (unsigned long)sdebug_dev_size_mb * 1048576;
  	sdebug_store_sectors = sz / sdebug_sector_size;
  	sdebug_capacity = get_sdebug_capacity();
  
  	/* play around with geometry, don't waste too much on track 0 */
  	sdebug_heads = 8;
  	sdebug_sectors_per = 32;
  	if (sdebug_dev_size_mb >= 256)
  		sdebug_heads = 64;
  	else if (sdebug_dev_size_mb >= 16)
  		sdebug_heads = 32;
  	sdebug_cylinders_per = (unsigned long)sdebug_capacity /
  			       (sdebug_sectors_per * sdebug_heads);
  	if (sdebug_cylinders_per >= 1024) {
  		/* other LLDs do this; implies >= 1GB ram disk ... */
  		sdebug_heads = 255;
  		sdebug_sectors_per = 63;
  		sdebug_cylinders_per = (unsigned long)sdebug_capacity /
  			       (sdebug_sectors_per * sdebug_heads);
  	}
  
  	if (sdebug_fake_rw == 0) {
  		fake_storep = vzalloc(sz);
  		if (NULL == fake_storep) {
  			pr_err("out of memory, 1\n");
  			ret = -ENOMEM;
  			goto free_q_arr;
  		}
  		if (sdebug_num_parts > 0)
  			sdebug_build_parts(fake_storep, sz);
  	}
  
  	if (sdebug_dix) {
  		int dif_size;
  
  		dif_size = sdebug_store_sectors * sizeof(struct t10_pi_tuple);
  		dif_storep = vmalloc(dif_size);
  
  		pr_err("dif_storep %u bytes @ %p\n", dif_size, dif_storep);
  
  		if (dif_storep == NULL) {
  			pr_err("out of mem. (DIX)\n");
  			ret = -ENOMEM;
  			goto free_vm;
  		}
  
  		memset(dif_storep, 0xff, dif_size);
  	}
  
  	/* Logical Block Provisioning */
  	if (scsi_debug_lbp()) {
  		sdebug_unmap_max_blocks =
  			clamp(sdebug_unmap_max_blocks, 0U, 0xffffffffU);
  
  		sdebug_unmap_max_desc =
  			clamp(sdebug_unmap_max_desc, 0U, 256U);
  
  		sdebug_unmap_granularity =
  			clamp(sdebug_unmap_granularity, 1U, 0xffffffffU);
  
  		if (sdebug_unmap_alignment &&
  		    sdebug_unmap_granularity <=
  		    sdebug_unmap_alignment) {
  			pr_err("ERR: unmap_granularity <= unmap_alignment\n");
  			ret = -EINVAL;
  			goto free_vm;
  		}
  
  		map_size = lba_to_map_index(sdebug_store_sectors - 1) + 1;
  		map_storep = vmalloc(array_size(sizeof(long),
  						BITS_TO_LONGS(map_size)));
  
  		pr_info("%lu provisioning blocks\n", map_size);
  
  		if (map_storep == NULL) {
  			pr_err("out of mem. (MAP)\n");
  			ret = -ENOMEM;
  			goto free_vm;
  		}
  
  		bitmap_zero(map_storep, map_size);
  
  		/* Map first 1KB for partition table */
  		if (sdebug_num_parts)
  			map_region(0, 2);
  	}
  
  	pseudo_primary = root_device_register("pseudo_0");
  	if (IS_ERR(pseudo_primary)) {
  		pr_warn("root_device_register() error\n");
  		ret = PTR_ERR(pseudo_primary);
  		goto free_vm;
  	}
  	ret = bus_register(&pseudo_lld_bus);
  	if (ret < 0) {
  		pr_warn("bus_register error: %d\n", ret);
  		goto dev_unreg;
  	}
  	ret = driver_register(&sdebug_driverfs_driver);
  	if (ret < 0) {
  		pr_warn("driver_register error: %d\n", ret);
  		goto bus_unreg;
  	}
  
  	host_to_add = sdebug_add_host;
  	sdebug_add_host = 0;
  
  	for (k = 0; k < host_to_add; k++) {
  		if (sdebug_add_adapter()) {
  			pr_err("sdebug_add_adapter failed k=%d\n", k);
  			break;
  		}
  	}
  
  	if (sdebug_verbose)
  		pr_info("built %d host(s)\n", sdebug_add_host);
  
  	return 0;
  
  bus_unreg:
  	bus_unregister(&pseudo_lld_bus);
  dev_unreg:
  	root_device_unregister(pseudo_primary);
  free_vm:
  	vfree(map_storep);
  	vfree(dif_storep);
  	vfree(fake_storep);
  free_q_arr:
  	kfree(sdebug_q_arr);
  	return ret;
  }
  
  static void __exit scsi_debug_exit(void)
  {
  	int k = sdebug_add_host;
  
  	stop_all_queued();
  	for (; k; k--)
  		sdebug_remove_adapter();
  	free_all_queued();
  	driver_unregister(&sdebug_driverfs_driver);
  	bus_unregister(&pseudo_lld_bus);
  	root_device_unregister(pseudo_primary);
  
  	vfree(map_storep);
  	vfree(dif_storep);
  	vfree(fake_storep);
  	kfree(sdebug_q_arr);
  }
  
  device_initcall(scsi_debug_init);
  module_exit(scsi_debug_exit);
  
  static void sdebug_release_adapter(struct device *dev)
  {
  	struct sdebug_host_info *sdbg_host;
  
  	sdbg_host = to_sdebug_host(dev);
  	kfree(sdbg_host);
  }
  
  static int sdebug_add_adapter(void)
  {
  	int k, devs_per_host;
  	int error = 0;
  	struct sdebug_host_info *sdbg_host;
  	struct sdebug_dev_info *sdbg_devinfo, *tmp;
  
  	sdbg_host = kzalloc(sizeof(*sdbg_host), GFP_KERNEL);
  	if (sdbg_host == NULL) {
  		pr_err("out of memory at line %d\n", __LINE__);
  		return -ENOMEM;
  	}
  
  	INIT_LIST_HEAD(&sdbg_host->dev_info_list);
  
  	devs_per_host = sdebug_num_tgts * sdebug_max_luns;
  	for (k = 0; k < devs_per_host; k++) {
  		sdbg_devinfo = sdebug_device_create(sdbg_host, GFP_KERNEL);
  		if (!sdbg_devinfo) {
  			pr_err("out of memory at line %d\n", __LINE__);
  			error = -ENOMEM;
  			goto clean;
  		}
  	}
  
  	spin_lock(&sdebug_host_list_lock);
  	list_add_tail(&sdbg_host->host_list, &sdebug_host_list);
  	spin_unlock(&sdebug_host_list_lock);
  
  	sdbg_host->dev.bus = &pseudo_lld_bus;
  	sdbg_host->dev.parent = pseudo_primary;
  	sdbg_host->dev.release = &sdebug_release_adapter;
  	dev_set_name(&sdbg_host->dev, "adapter%d", sdebug_add_host);
  
  	error = device_register(&sdbg_host->dev);
  
  	if (error)
  		goto clean;
  
  	++sdebug_add_host;
  	return error;
  
  clean:
  	list_for_each_entry_safe(sdbg_devinfo, tmp, &sdbg_host->dev_info_list,
  				 dev_list) {
  		list_del(&sdbg_devinfo->dev_list);
  		kfree(sdbg_devinfo);
  	}
  
  	kfree(sdbg_host);
  	return error;
  }
  
  static void sdebug_remove_adapter(void)
  {
  	struct sdebug_host_info *sdbg_host = NULL;
  
  	spin_lock(&sdebug_host_list_lock);
  	if (!list_empty(&sdebug_host_list)) {
  		sdbg_host = list_entry(sdebug_host_list.prev,
  				       struct sdebug_host_info, host_list);
  		list_del(&sdbg_host->host_list);
  	}
  	spin_unlock(&sdebug_host_list_lock);
  
  	if (!sdbg_host)
  		return;
  
  	device_unregister(&sdbg_host->dev);
  	--sdebug_add_host;
  }
  
  static int sdebug_change_qdepth(struct scsi_device *sdev, int qdepth)
  {
  	int num_in_q = 0;
  	struct sdebug_dev_info *devip;
  
  	block_unblock_all_queues(true);
  	devip = (struct sdebug_dev_info *)sdev->hostdata;
  	if (NULL == devip) {
  		block_unblock_all_queues(false);
  		return	-ENODEV;
  	}
  	num_in_q = atomic_read(&devip->num_in_q);
  
  	if (qdepth < 1)
  		qdepth = 1;
  	/* allow to exceed max host qc_arr elements for testing */
  	if (qdepth > SDEBUG_CANQUEUE + 10)
  		qdepth = SDEBUG_CANQUEUE + 10;
  	scsi_change_queue_depth(sdev, qdepth);
  
  	if (SDEBUG_OPT_Q_NOISE & sdebug_opts) {
  		sdev_printk(KERN_INFO, sdev, "%s: qdepth=%d, num_in_q=%d\n",
  			    __func__, qdepth, num_in_q);
  	}
  	block_unblock_all_queues(false);
  	return sdev->queue_depth;
  }
  
  static bool fake_timeout(struct scsi_cmnd *scp)
  {
  	if (0 == (atomic_read(&sdebug_cmnd_count) % abs(sdebug_every_nth))) {
  		if (sdebug_every_nth < -1)
  			sdebug_every_nth = -1;
  		if (SDEBUG_OPT_TIMEOUT & sdebug_opts)
  			return true; /* ignore command causing timeout */
  		else if (SDEBUG_OPT_MAC_TIMEOUT & sdebug_opts &&
  			 scsi_medium_access_command(scp))
  			return true; /* time out reads and writes */
  	}
  	return false;
  }
  
  static bool fake_host_busy(struct scsi_cmnd *scp)
  {
  	return (sdebug_opts & SDEBUG_OPT_HOST_BUSY) &&
  		(atomic_read(&sdebug_cmnd_count) % abs(sdebug_every_nth)) == 0;
  }
  
  static int scsi_debug_queuecommand(struct Scsi_Host *shost,
  				   struct scsi_cmnd *scp)
  {
  	u8 sdeb_i;
  	struct scsi_device *sdp = scp->device;
  	const struct opcode_info_t *oip;
  	const struct opcode_info_t *r_oip;
  	struct sdebug_dev_info *devip;
  	u8 *cmd = scp->cmnd;
  	int (*r_pfp)(struct scsi_cmnd *, struct sdebug_dev_info *);
  	int (*pfp)(struct scsi_cmnd *, struct sdebug_dev_info *) = NULL;
  	int k, na;
  	int errsts = 0;
  	u32 flags;
  	u16 sa;
  	u8 opcode = cmd[0];
  	bool has_wlun_rl;
  
  	scsi_set_resid(scp, 0);
  	if (sdebug_statistics)
  		atomic_inc(&sdebug_cmnd_count);
  	if (unlikely(sdebug_verbose &&
  		     !(SDEBUG_OPT_NO_CDB_NOISE & sdebug_opts))) {
  		char b[120];
  		int n, len, sb;
  
  		len = scp->cmd_len;
  		sb = (int)sizeof(b);
  		if (len > 32)
  			strcpy(b, "too long, over 32 bytes");
  		else {
  			for (k = 0, n = 0; k < len && n < sb; ++k)
  				n += scnprintf(b + n, sb - n, "%02x ",
  					       (u32)cmd[k]);
  		}
  		sdev_printk(KERN_INFO, sdp, "%s: tag=%#x, cmd %s\n", my_name,
  			    blk_mq_unique_tag(scp->request), b);
  	}
  	if (fake_host_busy(scp))
  		return SCSI_MLQUEUE_HOST_BUSY;
  	has_wlun_rl = (sdp->lun == SCSI_W_LUN_REPORT_LUNS);
  	if (unlikely((sdp->lun >= sdebug_max_luns) && !has_wlun_rl))
  		goto err_out;
  
  	sdeb_i = opcode_ind_arr[opcode];	/* fully mapped */
  	oip = &opcode_info_arr[sdeb_i];		/* safe if table consistent */
  	devip = (struct sdebug_dev_info *)sdp->hostdata;
  	if (unlikely(!devip)) {
  		devip = find_build_dev_info(sdp);
  		if (NULL == devip)
  			goto err_out;
  	}
  	na = oip->num_attached;
  	r_pfp = oip->pfp;
  	if (na) {	/* multiple commands with this opcode */
  		r_oip = oip;
  		if (FF_SA & r_oip->flags) {
  			if (F_SA_LOW & oip->flags)
  				sa = 0x1f & cmd[1];
  			else
  				sa = get_unaligned_be16(cmd + 8);
  			for (k = 0; k <= na; oip = r_oip->arrp + k++) {
  				if (opcode == oip->opcode && sa == oip->sa)
  					break;
  			}
  		} else {   /* since no service action only check opcode */
  			for (k = 0; k <= na; oip = r_oip->arrp + k++) {
  				if (opcode == oip->opcode)
  					break;
  			}
  		}
  		if (k > na) {
  			if (F_SA_LOW & r_oip->flags)
  				mk_sense_invalid_fld(scp, SDEB_IN_CDB, 1, 4);
  			else if (F_SA_HIGH & r_oip->flags)
  				mk_sense_invalid_fld(scp, SDEB_IN_CDB, 8, 7);
  			else
  				mk_sense_invalid_opcode(scp);
  			goto check_cond;
  		}
  	}	/* else (when na==0) we assume the oip is a match */
  	flags = oip->flags;
  	if (unlikely(F_INV_OP & flags)) {
  		mk_sense_invalid_opcode(scp);
  		goto check_cond;
  	}
  	if (unlikely(has_wlun_rl && !(F_RL_WLUN_OK & flags))) {
  		if (sdebug_verbose)
  			sdev_printk(KERN_INFO, sdp, "%s: Opcode 0x%x not%s\n",
  				    my_name, opcode, " supported for wlun");
  		mk_sense_invalid_opcode(scp);
  		goto check_cond;
  	}
  	if (unlikely(sdebug_strict)) {	/* check cdb against mask */
  		u8 rem;
  		int j;
  
  		for (k = 1; k < oip->len_mask[0] && k < 16; ++k) {
  			rem = ~oip->len_mask[k] & cmd[k];
  			if (rem) {
  				for (j = 7; j >= 0; --j, rem <<= 1) {
  					if (0x80 & rem)
  						break;
  				}
  				mk_sense_invalid_fld(scp, SDEB_IN_CDB, k, j);
  				goto check_cond;
  			}
  		}
  	}
  	if (unlikely(!(F_SKIP_UA & flags) &&
  		     find_first_bit(devip->uas_bm,
  				    SDEBUG_NUM_UAS) != SDEBUG_NUM_UAS)) {
  		errsts = make_ua(scp, devip);
  		if (errsts)
  			goto check_cond;
  	}
  	if (unlikely((F_M_ACCESS & flags) && atomic_read(&devip->stopped))) {
  		mk_sense_buffer(scp, NOT_READY, LOGICAL_UNIT_NOT_READY, 0x2);
  		if (sdebug_verbose)
  			sdev_printk(KERN_INFO, sdp, "%s reports: Not ready: "
  				    "%s\n", my_name, "initializing command "
  				    "required");
  		errsts = check_condition_result;
  		goto fini;
  	}
  	if (sdebug_fake_rw && (F_FAKE_RW & flags))
  		goto fini;
  	if (unlikely(sdebug_every_nth)) {
  		if (fake_timeout(scp))
  			return 0;	/* ignore command: make trouble */
  	}
  	if (likely(oip->pfp))
  		pfp = oip->pfp;	/* calls a resp_* function */
  	else
  		pfp = r_pfp;    /* if leaf function ptr NULL, try the root's */
  
  fini:
  	if (F_DELAY_OVERR & flags)
  		return schedule_resp(scp, devip, errsts, pfp, 0, 0);
  	else if ((flags & F_LONG_DELAY) && (sdebug_jdelay > 0 ||
  					    sdebug_ndelay > 10000)) {
  		/*
  		 * Skip long delays if ndelay <= 10 microseconds. Otherwise
  		 * for Start Stop Unit (SSU) want at least 1 second delay and
  		 * if sdebug_jdelay>1 want a long delay of that many seconds.
  		 * For Synchronize Cache want 1/20 of SSU's delay.
  		 */
  		int jdelay = (sdebug_jdelay < 2) ? 1 : sdebug_jdelay;
  		int denom = (flags & F_SYNC_DELAY) ? 20 : 1;
  
  		jdelay = mult_frac(USER_HZ * jdelay, HZ, denom * USER_HZ);
  		return schedule_resp(scp, devip, errsts, pfp, jdelay, 0);
  	} else
  		return schedule_resp(scp, devip, errsts, pfp, sdebug_jdelay,
  				     sdebug_ndelay);
  check_cond:
  	return schedule_resp(scp, devip, check_condition_result, NULL, 0, 0);
  err_out:
  	return schedule_resp(scp, NULL, DID_NO_CONNECT << 16, NULL, 0, 0);
  }
  
  static struct scsi_host_template sdebug_driver_template = {
  	.show_info =		scsi_debug_show_info,
  	.write_info =		scsi_debug_write_info,
  	.proc_name =		sdebug_proc_name,
  	.name =			"SCSI DEBUG",
  	.info =			scsi_debug_info,
  	.slave_alloc =		scsi_debug_slave_alloc,
  	.slave_configure =	scsi_debug_slave_configure,
  	.slave_destroy =	scsi_debug_slave_destroy,
  	.ioctl =		scsi_debug_ioctl,
  	.queuecommand =		scsi_debug_queuecommand,
  	.change_queue_depth =	sdebug_change_qdepth,
  	.eh_abort_handler =	scsi_debug_abort,
  	.eh_device_reset_handler = scsi_debug_device_reset,
  	.eh_target_reset_handler = scsi_debug_target_reset,
  	.eh_bus_reset_handler = scsi_debug_bus_reset,
  	.eh_host_reset_handler = scsi_debug_host_reset,
  	.can_queue =		SDEBUG_CANQUEUE,
  	.this_id =		7,
  	.sg_tablesize =		SG_MAX_SEGMENTS,
  	.cmd_per_lun =		DEF_CMD_PER_LUN,
  	.max_sectors =		-1U,
  	.max_segment_size =	-1U,
  	.module =		THIS_MODULE,
  	.track_queue_depth =	1,
  };
  
  static int sdebug_driver_probe(struct device *dev)
  {
  	int error = 0;
  	struct sdebug_host_info *sdbg_host;
  	struct Scsi_Host *hpnt;
  	int hprot;
  
  	sdbg_host = to_sdebug_host(dev);
  
  	sdebug_driver_template.can_queue = sdebug_max_queue;
  	if (!sdebug_clustering)
  		sdebug_driver_template.dma_boundary = PAGE_SIZE - 1;
  
  	hpnt = scsi_host_alloc(&sdebug_driver_template, sizeof(sdbg_host));
  	if (NULL == hpnt) {
  		pr_err("scsi_host_alloc failed\n");
  		error = -ENODEV;
  		return error;
  	}
  	if (submit_queues > nr_cpu_ids) {
  		pr_warn("%s: trim submit_queues (was %d) to nr_cpu_ids=%u\n",
  			my_name, submit_queues, nr_cpu_ids);
  		submit_queues = nr_cpu_ids;
  	}
  	/* Decide whether to tell scsi subsystem that we want mq */
  	/* Following should give the same answer for each host */
  	hpnt->nr_hw_queues = submit_queues;
  
  	sdbg_host->shost = hpnt;
  	*((struct sdebug_host_info **)hpnt->hostdata) = sdbg_host;
  	if ((hpnt->this_id >= 0) && (sdebug_num_tgts > hpnt->this_id))
  		hpnt->max_id = sdebug_num_tgts + 1;
  	else
  		hpnt->max_id = sdebug_num_tgts;
  	/* = sdebug_max_luns; */
  	hpnt->max_lun = SCSI_W_LUN_REPORT_LUNS + 1;
  
  	hprot = 0;
  
  	switch (sdebug_dif) {
  
  	case T10_PI_TYPE1_PROTECTION:
  		hprot = SHOST_DIF_TYPE1_PROTECTION;
  		if (sdebug_dix)
  			hprot |= SHOST_DIX_TYPE1_PROTECTION;
  		break;
  
  	case T10_PI_TYPE2_PROTECTION:
  		hprot = SHOST_DIF_TYPE2_PROTECTION;
  		if (sdebug_dix)
  			hprot |= SHOST_DIX_TYPE2_PROTECTION;
  		break;
  
  	case T10_PI_TYPE3_PROTECTION:
  		hprot = SHOST_DIF_TYPE3_PROTECTION;
  		if (sdebug_dix)
  			hprot |= SHOST_DIX_TYPE3_PROTECTION;
  		break;
  
  	default:
  		if (sdebug_dix)
  			hprot |= SHOST_DIX_TYPE0_PROTECTION;
  		break;
  	}
  
  	scsi_host_set_prot(hpnt, hprot);
  
  	if (have_dif_prot || sdebug_dix)
  		pr_info("host protection%s%s%s%s%s%s%s\n",
  			(hprot & SHOST_DIF_TYPE1_PROTECTION) ? " DIF1" : "",
  			(hprot & SHOST_DIF_TYPE2_PROTECTION) ? " DIF2" : "",
  			(hprot & SHOST_DIF_TYPE3_PROTECTION) ? " DIF3" : "",
  			(hprot & SHOST_DIX_TYPE0_PROTECTION) ? " DIX0" : "",
  			(hprot & SHOST_DIX_TYPE1_PROTECTION) ? " DIX1" : "",
  			(hprot & SHOST_DIX_TYPE2_PROTECTION) ? " DIX2" : "",
  			(hprot & SHOST_DIX_TYPE3_PROTECTION) ? " DIX3" : "");
  
  	if (sdebug_guard == 1)
  		scsi_host_set_guard(hpnt, SHOST_DIX_GUARD_IP);
  	else
  		scsi_host_set_guard(hpnt, SHOST_DIX_GUARD_CRC);
  
  	sdebug_verbose = !!(SDEBUG_OPT_NOISE & sdebug_opts);
  	sdebug_any_injecting_opt = !!(SDEBUG_OPT_ALL_INJECTING & sdebug_opts);
  	if (sdebug_every_nth)	/* need stats counters for every_nth */
  		sdebug_statistics = true;
  	error = scsi_add_host(hpnt, &sdbg_host->dev);
  	if (error) {
  		pr_err("scsi_add_host failed\n");
  		error = -ENODEV;
  		scsi_host_put(hpnt);
  	} else
  		scsi_scan_host(hpnt);
  
  	return error;
  }
  
  static int sdebug_driver_remove(struct device *dev)
  {
  	struct sdebug_host_info *sdbg_host;
  	struct sdebug_dev_info *sdbg_devinfo, *tmp;
  
  	sdbg_host = to_sdebug_host(dev);
  
  	if (!sdbg_host) {
  		pr_err("Unable to locate host info\n");
  		return -ENODEV;
  	}
  
  	scsi_remove_host(sdbg_host->shost);
  
  	list_for_each_entry_safe(sdbg_devinfo, tmp, &sdbg_host->dev_info_list,
  				 dev_list) {
  		list_del(&sdbg_devinfo->dev_list);
  		kfree(sdbg_devinfo);
  	}
  
  	scsi_host_put(sdbg_host->shost);
  	return 0;
  }
  
  static int pseudo_lld_bus_match(struct device *dev,
  				struct device_driver *dev_driver)
  {
  	return 1;
  }
  
  static struct bus_type pseudo_lld_bus = {
  	.name = "pseudo",
  	.match = pseudo_lld_bus_match,
  	.probe = sdebug_driver_probe,
  	.remove = sdebug_driver_remove,
  	.drv_groups = sdebug_drv_groups,
  };
  