pds_vdpa: set features order

[linux.git] / drivers / scsi / scsi_debug.c

// 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 - 2021 Douglas Gilbert
 *
 *  For documentation see http://sg.danny.cz/sg/scsi_debug.html
 */


#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__

#include <linux/module.h>
#include <linux/align.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/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 <linux/msdos_partition.h>
#include <linux/random.h>
#include <linux/xarray.h>
#include <linux/prefetch.h>
#include <linux/debugfs.h>
#include <linux/async.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 "0191"   /* format to fit INQUIRY revision field */
static const char *sdebug_version_date = "20210520";

#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 POWER_ON_OCCURRED_ASCQ 0x1
#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
#define UNALIGNED_WRITE_ASCQ 0x4
#define WRITE_BOUNDARY_ASCQ 0x5
#define READ_INVDATA_ASCQ 0x6
#define READ_BOUNDARY_ASCQ 0x7
#define ATTEMPT_ACCESS_GAP 0x9
#define INSUFF_ZONE_ASCQ 0xe

/* 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_PRE_INIT   0
#define DEF_DEV_SIZE_MB   8
#define DEF_ZBC_DEV_SIZE_MB   128
#define DEF_DIF 0
#define DEF_DIX 0
#define DEF_PER_HOST_STORE false
#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_RANDOM false
#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_TUR_MS_TO_READY 0
#define DEF_UUID_CTL 0
#define JDELAY_OVERRIDDEN -9999

/* Default parameters for ZBC drives */
#define DEF_ZBC_ZONE_SIZE_MB    128
#define DEF_ZBC_MAX_OPEN_ZONES  8
#define DEF_ZBC_NR_CONV_ZONES   1

#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   /* ignore */
#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)
#define SDEBUG_OPT_RECOV_DIF_DIX (SDEBUG_OPT_RECOVERED_ERR | \
                                  SDEBUG_OPT_DIF_ERR | SDEBUG_OPT_DIX_ERR)

/* 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_POOCCUR 1     /* Power on occurred */
#define SDEBUG_UA_BUS_RESET 2
#define SDEBUG_UA_MODE_CHANGED 3
#define SDEBUG_UA_CAPACITY_CHANGED 4
#define SDEBUG_UA_LUNS_CHANGED 5
#define SDEBUG_UA_MICROCODE_CHANGED 6   /* simulate firmware change */
#define SDEBUG_UA_MICROCODE_CHANGED_WO_RESET 7
#define SDEBUG_NUM_UAS 8

/* 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 */

/* 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  SDEBUG_CANQUEUE

/* UA - Unit Attention; SA - Service Action; SSU - Start Stop Unit */
#define F_D_IN                  1       /* Data-in command (e.g. READ) */
#define F_D_OUT                 2       /* Data-out command (e.g. WRITE) */
#define F_D_OUT_MAYBE           4       /* WRITE SAME, NDOB bit */
#define F_D_UNKN                8
#define F_RL_WLUN_OK            0x10    /* allowed with REPORT LUNS W-LUN */
#define F_SKIP_UA               0x20    /* bypass UAs (e.g. INQUIRY command) */
#define F_DELAY_OVERR           0x40    /* for commands like INQUIRY */
#define F_SA_LOW                0x80    /* SA is in cdb byte 1, bits 4 to 0 */
#define F_SA_HIGH               0x100   /* SA is in cdb bytes 8 and 9 */
#define F_INV_OP                0x200   /* invalid opcode (not supported) */
#define F_FAKE_RW               0x400   /* bypass resp_*() when fake_rw set */
#define F_M_ACCESS              0x800   /* media access, reacts to SSU state */
#define F_SSU_DELAY             0x1000  /* SSU command delay (long-ish) */
#define F_SYNC_DELAY            0x2000  /* SYNCHRONIZE CACHE delay */

/* Useful combinations of the above flags */
#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

#define SDEB_XA_NOT_IN_USE XA_MARK_1

static struct kmem_cache *queued_cmd_cache;

#define TO_QUEUED_CMD(scmd)  ((void *)(scmd)->host_scribble)
#define ASSIGN_QUEUED_CMD(scmnd, qc) { (scmnd)->host_scribble = (void *) qc; }

/* Zone types (zbcr05 table 25) */
enum sdebug_z_type {
        ZBC_ZTYPE_CNV   = 0x1,
        ZBC_ZTYPE_SWR   = 0x2,
        ZBC_ZTYPE_SWP   = 0x3,
        /* ZBC_ZTYPE_SOBR = 0x4, */
        ZBC_ZTYPE_GAP   = 0x5,
};

/* enumeration names taken from table 26, zbcr05 */
enum sdebug_z_cond {
        ZBC_NOT_WRITE_POINTER   = 0x0,
        ZC1_EMPTY               = 0x1,
        ZC2_IMPLICIT_OPEN       = 0x2,
        ZC3_EXPLICIT_OPEN       = 0x3,
        ZC4_CLOSED              = 0x4,
        ZC6_READ_ONLY           = 0xd,
        ZC5_FULL                = 0xe,
        ZC7_OFFLINE             = 0xf,
};

struct sdeb_zone_state {        /* ZBC: per zone state */
        enum sdebug_z_type z_type;
        enum sdebug_z_cond z_cond;
        bool z_non_seq_resource;
        unsigned int z_size;
        sector_t z_start;
        sector_t z_wp;
};

enum sdebug_err_type {
        ERR_TMOUT_CMD           = 0,    /* make specific scsi command timeout */
        ERR_FAIL_QUEUE_CMD      = 1,    /* make specific scsi command's */
                                        /* queuecmd return failed */
        ERR_FAIL_CMD            = 2,    /* make specific scsi command's */
                                        /* queuecmd return succeed but */
                                        /* with errors set in scsi_cmnd */
        ERR_ABORT_CMD_FAILED    = 3,    /* control return FAILED from */
                                        /* scsi_debug_abort() */
        ERR_LUN_RESET_FAILED    = 4,    /* control return FAILED from */
                                        /* scsi_debug_device_reseLUN_RESET_FAILEDt() */
};

struct sdebug_err_inject {
        int type;
        struct list_head list;
        int cnt;
        unsigned char cmd;
        struct rcu_head rcu;

        union {
                /*
                 * For ERR_FAIL_QUEUE_CMD
                 */
                int queuecmd_ret;

                /*
                 * For ERR_FAIL_CMD
                 */
                struct {
                        unsigned char host_byte;
                        unsigned char driver_byte;
                        unsigned char status_byte;
                        unsigned char sense_key;
                        unsigned char asc;
                        unsigned char asq;
                };
        };
};

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 stopped;       /* 1: by SSU, 2: device start */
        bool used;

        /* For ZBC devices */
        enum blk_zoned_model zmodel;
        unsigned int zcap;
        unsigned int zsize;
        unsigned int zsize_shift;
        unsigned int nr_zones;
        unsigned int nr_conv_zones;
        unsigned int nr_seq_zones;
        unsigned int nr_imp_open;
        unsigned int nr_exp_open;
        unsigned int nr_closed;
        unsigned int max_open;
        ktime_t create_ts;      /* time since bootup that this device was created */
        struct sdeb_zone_state *zstate;

        struct dentry *debugfs_entry;
        struct spinlock list_lock;
        struct list_head inject_err_list;
};

struct sdebug_target_info {
        bool reset_fail;
        struct dentry *debugfs_entry;
};

struct sdebug_host_info {
        struct list_head host_list;
        int si_idx;     /* sdeb_store_info (per host) xarray index */
        struct Scsi_Host *shost;
        struct device dev;
        struct list_head dev_info_list;
};

/* There is an xarray of pointers to this struct's objects, one per host */
struct sdeb_store_info {
        rwlock_t macc_lck;      /* for atomic media access on this store */
        u8 *storep;             /* user data storage (ram) */
        struct t10_pi_tuple *dif_storep; /* protection info */
        void *map_storep;       /* provisioning map */
};

#define dev_to_sdebug_host(d)   \
        container_of(d, struct sdebug_host_info, dev)

#define shost_to_sdebug_host(shost)     \
        dev_to_sdebug_host(shost->dma_dev)

enum sdeb_defer_type {SDEB_DEFER_NONE = 0, SDEB_DEFER_HRT = 1,
                      SDEB_DEFER_WQ = 2, SDEB_DEFER_POLL = 3};

struct sdebug_defer {
        struct hrtimer hrt;
        struct execute_work ew;
        ktime_t cmpl_ts;/* time since boot to complete this cmd */
        int issuing_cpu;
        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 *scmd;
};

struct sdebug_scsi_cmd {
        spinlock_t   lock;
};

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 */
static atomic_t sdeb_inject_pending;
static atomic_t sdeb_mq_poll_count;  /* bumped when mq_poll returns > 0 */

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,             /* VERIFY(10), VERIFY(16) */
        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_PRE_FETCH = 29,          /* 10, 16 */
        SDEB_I_ZONE_OUT = 30,           /* 0x94+SA; includes no data xfer */
        SDEB_I_ZONE_IN = 31,            /* 0x95+SA; all have data-in */
        SDEB_I_LAST_ELEM_P1 = 32,       /* 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, SDEB_I_PRE_FETCH, 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, SDEB_I_VERIFY,
        SDEB_I_PRE_FETCH, SDEB_I_SYNC_CACHE, 0, SDEB_I_WRITE_SAME,
        SDEB_I_ZONE_OUT, SDEB_I_ZONE_IN, 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_verify(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 *);
static int resp_pre_fetch(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_report_zones(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_open_zone(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_close_zone(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_finish_zone(struct scsi_cmnd *, struct sdebug_dev_info *);
static int resp_rwp_zone(struct scsi_cmnd *, struct sdebug_dev_info *);

static int sdebug_do_add_host(bool mk_new_store);
static int sdebug_add_host_helper(int per_host_idx);
static void sdebug_do_remove_host(bool the_end);
static int sdebug_add_store(void);
static void sdebug_erase_store(int idx, struct sdeb_store_info *sip);
static void sdebug_erase_all_stores(bool apart_from_first);

static void sdebug_free_queued_cmd(struct sdebug_queued_cmd *sqcp);

/*
 * 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 verify_iarr[] = {
        {0, 0x2f, 0, F_D_OUT_MAYBE | FF_MEDIA_IO, resp_verify,/* VERIFY(10) */
            NULL, {10,  0xf7, 0xff, 0xff, 0xff, 0xff, 0xbf, 0xff, 0xff, 0xc7,
                   0, 0, 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) */
};

static const struct opcode_info_t pre_fetch_iarr[] = {
        {0, 0x90, 0, F_SYNC_DELAY | FF_MEDIA_IO, resp_pre_fetch, NULL,
            {16,  0x2, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
             0xff, 0xff, 0xff, 0xff, 0x3f, 0xc7} },     /* PRE-FETCH (16) */
};

static const struct opcode_info_t zone_out_iarr[] = {   /* ZONE OUT(16) */
        {0, 0x94, 0x1, F_SA_LOW | F_M_ACCESS, resp_close_zone, NULL,
            {16, 0x1, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
             0xff, 0, 0, 0xff, 0xff, 0x1, 0xc7} },      /* CLOSE ZONE */
        {0, 0x94, 0x2, F_SA_LOW | F_M_ACCESS, resp_finish_zone, NULL,
            {16, 0x2, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
             0xff, 0, 0, 0xff, 0xff, 0x1, 0xc7} },      /* FINISH ZONE */
        {0, 0x94, 0x4, F_SA_LOW | F_M_ACCESS, resp_rwp_zone, NULL,
            {16, 0x4, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
             0xff, 0, 0, 0xff, 0xff, 0x1, 0xc7} },  /* RESET WRITE POINTER */
};

static const struct opcode_info_t zone_in_iarr[] = {    /* ZONE IN(16) */
        {0, 0x95, 0x6, F_SA_LOW | F_D_IN | F_M_ACCESS, NULL, NULL,
            {16, 0x6, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
             0xff, 0xff, 0xff, 0xff, 0x3f, 0xc7} }, /* REPORT ZONES */
};


/* 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_ELEM_P1 + 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} },
        {ARRAY_SIZE(verify_iarr), 0x8f, 0,
            F_D_OUT_MAYBE | FF_MEDIA_IO, resp_verify,   /* VERIFY(16) */
            verify_iarr, {16,  0xf6, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                          0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xc7} },
        {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 */
        {ARRAY_SIZE(pre_fetch_iarr), 0x34, 0, F_SYNC_DELAY | FF_MEDIA_IO,
            resp_pre_fetch, pre_fetch_iarr,
            {10,  0x2, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff, 0xff, 0xc7, 0, 0,
             0, 0, 0, 0} },                     /* PRE-FETCH (10) */

/* 30 */
        {ARRAY_SIZE(zone_out_iarr), 0x94, 0x3, F_SA_LOW | F_M_ACCESS,
            resp_open_zone, zone_out_iarr, /* ZONE_OUT(16), OPEN ZONE) */
                {16,  0x3 /* SA */, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                 0xff, 0xff, 0x0, 0x0, 0xff, 0xff, 0x1, 0xc7} },
        {ARRAY_SIZE(zone_in_iarr), 0x95, 0x0, F_SA_LOW | F_M_ACCESS,
            resp_report_zones, zone_in_iarr, /* ZONE_IN(16), REPORT ZONES) */
                {16,  0x0 /* SA */, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xbf, 0xc7} },
/* sentinel */
        {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_num_hosts;
static int sdebug_add_host = DEF_NUM_HOST;  /* in sysfs this is relative */
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_PRE_INIT;
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_host_max_queue;       /* per host */
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 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 sdeb_tur_ms_to_ready = DEF_TUR_MS_TO_READY;
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_random = DEF_RANDOM;
static bool sdebug_per_host_store = DEF_PER_HOST_STORE;
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_no_rwlock;
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 bool sdebug_allow_restart;
/* Following enum: 0: no zbc, def; 1: host aware; 2: host managed */
static enum blk_zoned_model sdeb_zbc_model = BLK_ZONED_NONE;
static char *sdeb_zbc_model_s;

enum sam_lun_addr_method {SAM_LUN_AM_PERIPHERAL = 0x0,
                          SAM_LUN_AM_FLAT = 0x1,
                          SAM_LUN_AM_LOGICAL_UNIT = 0x2,
                          SAM_LUN_AM_EXTENDED = 0x3};
static enum sam_lun_addr_method sdebug_lun_am = SAM_LUN_AM_PERIPHERAL;
static int sdebug_lun_am_i = (int)SAM_LUN_AM_PERIPHERAL;

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_MUTEX(sdebug_host_list_mutex);

static struct xarray per_store_arr;
static struct xarray *per_store_ap = &per_store_arr;
static int sdeb_first_idx = -1;         /* invalid index ==> none created */
static int sdeb_most_recent_idx = -1;
static DEFINE_RWLOCK(sdeb_fake_rw_lck); /* need a RW lock when fake_rw=1 */

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;

/* ZBC global data */
static bool sdeb_zbc_in_use;    /* true for host-aware and host-managed disks */
static int sdeb_zbc_zone_cap_mb;
static int sdeb_zbc_zone_size_mb;
static int sdeb_zbc_max_open = DEF_ZBC_MAX_OPEN_ZONES;
static int sdeb_zbc_nr_conv = DEF_ZBC_NR_CONV_ZONES;

static int submit_queues = DEF_SUBMIT_QUEUES;  /* > 1 for multi-queue (mq) */
static int poll_queues; /* iouring iopoll interface.*/

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 =
        SAM_STAT_CHECK_CONDITION;

static const int illegal_condition_result =
        (DID_ABORT << 16) | SAM_STAT_CHECK_CONDITION;

static const int device_qfull_result =
        (DID_ABORT << 16) | SAM_STAT_TASK_SET_FULL;

static const int condition_met_result = SAM_STAT_CONDITION_MET;

static struct dentry *sdebug_debugfs_root;

static void sdebug_err_free(struct rcu_head *head)
{
        struct sdebug_err_inject *inject =
                container_of(head, typeof(*inject), rcu);

        kfree(inject);
}

static void sdebug_err_add(struct scsi_device *sdev, struct sdebug_err_inject *new)
{
        struct sdebug_dev_info *devip = (struct sdebug_dev_info *)sdev->hostdata;
        struct sdebug_err_inject *err;

        spin_lock(&devip->list_lock);
        list_for_each_entry_rcu(err, &devip->inject_err_list, list) {
                if (err->type == new->type && err->cmd == new->cmd) {
                        list_del_rcu(&err->list);
                        call_rcu(&err->rcu, sdebug_err_free);
                }
        }

        list_add_tail_rcu(&new->list, &devip->inject_err_list);
        spin_unlock(&devip->list_lock);
}

static int sdebug_err_remove(struct scsi_device *sdev, const char *buf, size_t count)
{
        struct sdebug_dev_info *devip = (struct sdebug_dev_info *)sdev->hostdata;
        struct sdebug_err_inject *err;
        int type;
        unsigned char cmd;

        if (sscanf(buf, "- %d %hhx", &type, &cmd) != 2) {
                kfree(buf);
                return -EINVAL;
        }

        spin_lock(&devip->list_lock);
        list_for_each_entry_rcu(err, &devip->inject_err_list, list) {
                if (err->type == type && err->cmd == cmd) {
                        list_del_rcu(&err->list);
                        call_rcu(&err->rcu, sdebug_err_free);
                        spin_unlock(&devip->list_lock);
                        kfree(buf);
                        return count;
                }
        }
        spin_unlock(&devip->list_lock);

        kfree(buf);
        return -EINVAL;
}

static int sdebug_error_show(struct seq_file *m, void *p)
{
        struct scsi_device *sdev = (struct scsi_device *)m->private;
        struct sdebug_dev_info *devip = (struct sdebug_dev_info *)sdev->hostdata;
        struct sdebug_err_inject *err;

        seq_puts(m, "Type\tCount\tCommand\n");

        rcu_read_lock();
        list_for_each_entry_rcu(err, &devip->inject_err_list, list) {
                switch (err->type) {
                case ERR_TMOUT_CMD:
                case ERR_ABORT_CMD_FAILED:
                case ERR_LUN_RESET_FAILED:
                        seq_printf(m, "%d\t%d\t0x%x\n", err->type, err->cnt,
                                err->cmd);
                break;

                case ERR_FAIL_QUEUE_CMD:
                        seq_printf(m, "%d\t%d\t0x%x\t0x%x\n", err->type,
                                err->cnt, err->cmd, err->queuecmd_ret);
                break;

                case ERR_FAIL_CMD:
                        seq_printf(m, "%d\t%d\t0x%x\t0x%x 0x%x 0x%x 0x%x 0x%x 0x%x\n",
                                err->type, err->cnt, err->cmd,
                                err->host_byte, err->driver_byte,
                                err->status_byte, err->sense_key,
                                err->asc, err->asq);
                break;
                }
        }
        rcu_read_unlock();

        return 0;
}

static int sdebug_error_open(struct inode *inode, struct file *file)
{
        return single_open(file, sdebug_error_show, inode->i_private);
}

static ssize_t sdebug_error_write(struct file *file, const char __user *ubuf,
                size_t count, loff_t *ppos)
{
        char *buf;
        unsigned int inject_type;
        struct sdebug_err_inject *inject;
        struct scsi_device *sdev = (struct scsi_device *)file->f_inode->i_private;

        buf = kzalloc(count + 1, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        if (copy_from_user(buf, ubuf, count)) {
                kfree(buf);
                return -EFAULT;
        }

        if (buf[0] == '-')
                return sdebug_err_remove(sdev, buf, count);

        if (sscanf(buf, "%d", &inject_type) != 1) {
                kfree(buf);
                return -EINVAL;
        }

        inject = kzalloc(sizeof(struct sdebug_err_inject), GFP_KERNEL);
        if (!inject) {
                kfree(buf);
                return -ENOMEM;
        }

        switch (inject_type) {
        case ERR_TMOUT_CMD:
        case ERR_ABORT_CMD_FAILED:
        case ERR_LUN_RESET_FAILED:
                if (sscanf(buf, "%d %d %hhx", &inject->type, &inject->cnt,
                           &inject->cmd) != 3)
                        goto out_error;
        break;

        case ERR_FAIL_QUEUE_CMD:
                if (sscanf(buf, "%d %d %hhx %x", &inject->type, &inject->cnt,
                           &inject->cmd, &inject->queuecmd_ret) != 4)
                        goto out_error;
        break;

        case ERR_FAIL_CMD:
                if (sscanf(buf, "%d %d %hhx %hhx %hhx %hhx %hhx %hhx %hhx",
                           &inject->type, &inject->cnt, &inject->cmd,
                           &inject->host_byte, &inject->driver_byte,
                           &inject->status_byte, &inject->sense_key,
                           &inject->asc, &inject->asq) != 9)
                        goto out_error;
        break;

        default:
                goto out_error;
        break;
        }

        kfree(buf);
        sdebug_err_add(sdev, inject);

        return count;

out_error:
        kfree(buf);
        kfree(inject);
        return -EINVAL;
}

static const struct file_operations sdebug_error_fops = {
        .open   = sdebug_error_open,
        .read   = seq_read,
        .write  = sdebug_error_write,
        .release = single_release,
};

static int sdebug_target_reset_fail_show(struct seq_file *m, void *p)
{
        struct scsi_target *starget = (struct scsi_target *)m->private;
        struct sdebug_target_info *targetip =
                (struct sdebug_target_info *)starget->hostdata;

        if (targetip)
                seq_printf(m, "%c\n", targetip->reset_fail ? 'Y' : 'N');

        return 0;
}

static int sdebug_target_reset_fail_open(struct inode *inode, struct file *file)
{
        return single_open(file, sdebug_target_reset_fail_show, inode->i_private);
}

static ssize_t sdebug_target_reset_fail_write(struct file *file,
                const char __user *ubuf, size_t count, loff_t *ppos)
{
        int ret;
        struct scsi_target *starget =
                (struct scsi_target *)file->f_inode->i_private;
        struct sdebug_target_info *targetip =
                (struct sdebug_target_info *)starget->hostdata;

        if (targetip) {
                ret = kstrtobool_from_user(ubuf, count, &targetip->reset_fail);
                return ret < 0 ? ret : count;
        }
        return -ENODEV;
}

static const struct file_operations sdebug_target_reset_fail_fops = {
        .open   = sdebug_target_reset_fail_open,
        .read   = seq_read,
        .write  = sdebug_target_reset_fail_write,
        .release = single_release,
};

static int sdebug_target_alloc(struct scsi_target *starget)
{
        struct sdebug_target_info *targetip;

        targetip = kzalloc(sizeof(struct sdebug_target_info), GFP_KERNEL);
        if (!targetip)
                return -ENOMEM;

        targetip->debugfs_entry = debugfs_create_dir(dev_name(&starget->dev),
                                sdebug_debugfs_root);

        debugfs_create_file("fail_reset", 0600, targetip->debugfs_entry, starget,
                                &sdebug_target_reset_fail_fops);

        starget->hostdata = targetip;

        return 0;
}

static void sdebug_tartget_cleanup_async(void *data, async_cookie_t cookie)
{
        struct sdebug_target_info *targetip = data;

        debugfs_remove(targetip->debugfs_entry);
        kfree(targetip);
}

static void sdebug_target_destroy(struct scsi_target *starget)
{
        struct sdebug_target_info *targetip;

        targetip = (struct sdebug_target_info *)starget->hostdata;
        if (targetip) {
                starget->hostdata = NULL;
                async_schedule(sdebug_tartget_cleanup_async, targetip);
        }
}

/* 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(struct sdeb_store_info *sip,
                            unsigned long long lba)
{
        struct sdeb_store_info *lsip = sip;

        lba = do_div(lba, sdebug_store_sectors);
        if (!sip || !sip->storep) {
                WARN_ON_ONCE(true);
                lsip = xa_load(per_store_ap, 0);  /* should never be NULL */
        }
        return lsip->storep + lba * sdebug_sector_size;
}

static struct t10_pi_tuple *dif_store(struct sdeb_store_info *sip,
                                      sector_t sector)
{
        sector = sector_div(sector, sdebug_store_sectors);

        return sip->dif_storep + sector;
}

static void sdebug_max_tgts_luns(void)
{
        struct sdebug_host_info *sdbg_host;
        struct Scsi_Host *hpnt;

        mutex_lock(&sdebug_host_list_mutex);
        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;
        }
        mutex_unlock(&sdebug_host_list_mutex);
}

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(scp, sdebug_dsense, 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)
{
        if (!scp->sense_buffer) {
                sdev_printk(KERN_ERR, scp->device,
                            "%s: sense_buffer is NULL\n", __func__);
                return;
        }
        memset(scp->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);

        scsi_build_sense(scp, sdebug_dsense, 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;

        mutex_lock(&sdebug_host_list_mutex);
        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);
                }
        }
        mutex_unlock(&sdebug_host_list_mutex);
}

static void clear_luns_changed_on_target(struct sdebug_dev_info *devip)
{
        struct sdebug_host_info *sdhp = devip->sdbg_host;
        struct sdebug_dev_info *dp;

        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);
                }
        }
}

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_POOCCUR:
                        mk_sense_buffer(scp, UNIT_ATTENTION, UA_RESET_ASC,
                                        POWER_ON_OCCURRED_ASCQ);
                        if (sdebug_verbose)
                                cp = "power on occurred";
                        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_t(u32, 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 */
}

/* Block device characteristics VPD page (SBC-3) */
static int inquiry_vpd_b1(struct sdebug_dev_info *devip, 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" */
        if (devip->zmodel == BLK_ZONED_HA)
                arr[4] = 1 << 4;        /* zoned field = 01b */

        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;
}

/* Zoned block device characteristics VPD page (ZBC mandatory) */
static int inquiry_vpd_b6(struct sdebug_dev_info *devip, unsigned char *arr)
{
        memset(arr, 0, 0x3c);
        arr[0] = 0x1; /* set URSWRZ (unrestricted read in seq. wr req zone) */
        /*
         * Set Optimal number of open sequential write preferred zones and
         * Optimal number of non-sequentially written sequential write
         * preferred zones fields to 'not reported' (0xffffffff). Leave other
         * fields set to zero, apart from Max. number of open swrz_s field.
         */
        put_unaligned_be32(0xffffffff, &arr[4]);
        put_unaligned_be32(0xffffffff, &arr[8]);
        if (sdeb_zbc_model == BLK_ZONED_HM && devip->max_open)
                put_unaligned_be32(devip->max_open, &arr[12]);
        else
                put_unaligned_be32(0xffffffff, &arr[12]);
        if (devip->zcap < devip->zsize) {
                arr[19] = ZBC_CONSTANT_ZONE_START_OFFSET;
                put_unaligned_be64(devip->zsize, &arr[20]);
        } else {
                arr[19] = 0;
        }
        return 0x3c;
}

#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;
        u32 alloc_len, n;
        int ret;
        bool have_wlun, is_disk, is_zbc, is_disk_zbc;

        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);
        is_zbc = (devip->zmodel != BLK_ZONED_NONE);
        is_disk_zbc = (is_disk || is_zbc);
        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;
                u32 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_zbc) {        /* SBC or ZBC */
                                arr[n++] = 0x89;  /* ATA information */
                                arr[n++] = 0xb0;  /* Block limits */
                                arr[n++] = 0xb1;  /* Block characteristics */
                                if (is_disk)
                                        arr[n++] = 0xb2;  /* LB Provisioning */
                                if (is_zbc)
                                        arr[n++] = 0xb6;  /* ZB dev. char. */
                        }
                        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_zbc && 0x89 == cmd[2]) { /* ATA info */
                        arr[1] = cmd[2];        /*sanity */
                        n = inquiry_vpd_89(&arr[4]);
                        put_unaligned_be16(n, arr + 2);
                } else if (is_disk_zbc && 0xb0 == cmd[2]) { /* Block limits */
                        arr[1] = cmd[2];        /*sanity */
                        arr[3] = inquiry_vpd_b0(&arr[4]);
                } else if (is_disk_zbc && 0xb1 == cmd[2]) { /* Block char. */
                        arr[1] = cmd[2];        /*sanity */
                        arr[3] = inquiry_vpd_b1(devip, &arr[4]);
                } else if (is_disk && 0xb2 == cmd[2]) { /* LB Prov. */
                        arr[1] = cmd[2];        /*sanity */
                        arr[3] = inquiry_vpd_b2(&arr[4]);
                } else if (is_zbc && cmd[2] == 0xb6) { /* ZB dev. charact. */
                        arr[1] = cmd[2];        /*sanity */
                        arr[3] = inquiry_vpd_b6(devip, &arr[4]);
                } else {
                        mk_sense_invalid_fld(scp, SDEB_IN_CDB, 2, -1);
                        kfree(arr);
                        return check_condition_result;
                }
                len = min_t(u32, get_unaligned_be16(arr + 2) + 4, alloc_len);
                ret = fill_from_dev_buffer(scp, arr,
                            min_t(u32, 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;
        } else if (is_zbc) {    /* ZBC BSR INCITS 536 revision 05 */
                put_unaligned_be16(0x624, arr + n);
                n += 2;
        }
        put_unaligned_be16(0x2100, arr + n);    /* SPL-4 no version claimed */
        ret = fill_from_dev_buffer(scp, arr,
                            min_t(u32, alloc_len, SDEBUG_LONG_INQ_SZ));
        kfree(arr);
        return ret;
}

/* See resp_iec_m_pg() for how this data is manipulated */
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 *cmd = scp->cmnd;
        unsigned char arr[SCSI_SENSE_BUFFERSIZE];       /* assume >= 18 bytes */
        bool dsense = !!(cmd[1] & 1);
        u32 alloc_len = cmd[4];
        u32 len = 18;
        int stopped_state = atomic_read(&devip->stopped);

        memset(arr, 0, sizeof(arr));
        if (stopped_state > 0) {        /* some "pollable" data [spc6r02: 5.12.2] */
                if (dsense) {
                        arr[0] = 0x72;
                        arr[1] = NOT_READY;
                        arr[2] = LOGICAL_UNIT_NOT_READY;
                        arr[3] = (stopped_state == 2) ? 0x1 : 0x2;
                        len = 8;
                } else {
                        arr[0] = 0x70;
                        arr[2] = NOT_READY;             /* NO_SENSE in sense_key */
                        arr[7] = 0xa;                   /* 18 byte sense buffer */
                        arr[12] = LOGICAL_UNIT_NOT_READY;
                        arr[13] = (stopped_state == 2) ? 0x1 : 0x2;
                }
        } else if ((iec_m_pg[2] & 0x4) && (6 == (iec_m_pg[3] & 0xf))) {
                /* Information exceptions control mode page: TEST=1, MRIE=6 */
                if (dsense) {
                        arr[0] = 0x72;
                        arr[1] = 0x0;           /* NO_SENSE in sense_key */
                        arr[2] = THRESHOLD_EXCEEDED;
                        arr[3] = 0xff;          /* Failure prediction(false) */
                        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;         /* Failure prediction(false) */
                }
        } else {        /* nothing to report */
                if (dsense) {
                        len = 8;
                        memset(arr, 0, len);
                        arr[0] = 0x72;
                } else {
                        memset(arr, 0, len);
                        arr[0] = 0x70;
                        arr[7] = 0xa;
                }
        }
        return fill_from_dev_buffer(scp, arr, min_t(u32, len, alloc_len));
}

static int resp_start_stop(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
{
        unsigned char *cmd = scp->cmnd;
        int power_cond, want_stop, stopped_state;
        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;
        }
        want_stop = !(cmd[4] & 1);
        stopped_state = atomic_read(&devip->stopped);
        if (stopped_state == 2) {
                ktime_t now_ts = ktime_get_boottime();

                if (ktime_to_ns(now_ts) > ktime_to_ns(devip->create_ts)) {
                        u64 diff_ns = ktime_to_ns(ktime_sub(now_ts, devip->create_ts));

                        if (diff_ns >= ((u64)sdeb_tur_ms_to_ready * 1000000)) {
                                /* tur_ms_to_ready timer extinguished */
                                atomic_set(&devip->stopped, 0);
                                stopped_state = 0;
                        }
                }
                if (stopped_state == 2) {
                        if (want_stop) {
                                stopped_state = 1;      /* dummy up success */
                        } else {        /* Disallow tur_ms_to_ready delay to be overridden */
                                mk_sense_invalid_fld(scp, SDEB_IN_CDB, 4, 0 /* START bit */);
                                return check_condition_result;
                        }
                }
        }
        changing = (stopped_state != want_stop);
        if (changing)
                atomic_xchg(&devip->stopped, want_stop);
        if (!changing || (cmd[1] & 0x1))  /* state unchanged or IMMED bit set in cdb */
                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];
        u32 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;
        }

        /*
         * Since the scsi_debug READ CAPACITY implementation always reports the
         * total disk capacity, set RC BASIS = 1 for host-managed ZBC devices.
         */
        if (devip->zmodel == BLK_ZONED_HM)
                arr[12] |= 1 << 4;

        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_t(u32, 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 port_group_a, port_group_b, port_a, port_b;
        u32 alen, n, rlen;
        int ret;

        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_t(u32, 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;
        u32 alloc_len, offset, len;
        int 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, is_zbc, 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);
        is_zbc = (devip->zmodel != BLK_ZONED_NONE);
        if ((is_disk || is_zbc) && !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+zbc set DPOFUA bit and clear write protect (WP) bit */
        if (is_disk || is_zbc) {
                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 || is_zbc) {
                        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);
                        } else if (is_zbc) {
                                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_t(u32, 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);
        off = bd_len + (mselect6 ? 4 : 8);
        if (md_len > 2 || off >= res) {
                mk_sense_invalid_fld(scp, SDEB_IN_DATA, 0, -1);
                return check_condition_result;
        }
        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);
}

static int resp_env_rep_l_spg(unsigned char *arr)
{
        unsigned char env_rep_l_spg[] = {0x0, 0x0, 0x23, 0x8,
                                         0x0, 40, 72, 0xff, 45, 18, 0, 0,
                                         0x1, 0x0, 0x23, 0x8,
                                         0x0, 55, 72, 35, 55, 45, 0, 0,
                };

        memcpy(arr, env_rep_l_spg, sizeof(env_rep_l_spg));
        return sizeof(env_rep_l_spg);
}

#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;
        u32 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++] = 0xd;
                        arr[n++] = 0x1;         /* Environment reporting */
                        arr[n++] = 0xd;
                        arr[n++] = 0xff;        /* all 0xd subpages */
                        arr[n++] = 0x2f;
                        arr[n++] = 0x0; /* Informational exceptions */
                        arr[n++] = 0x2f;
                        arr[n++] = 0xff;        /* all 0x2f subpages */
                        arr[3] = n - 4;
                        break;
                case 0xd:       /* Temperature subpages */
                        n = 4;
                        arr[n++] = 0xd;
                        arr[n++] = 0x0;         /* Temperature */
                        arr[n++] = 0xd;
                        arr[n++] = 0x1;         /* Environment reporting */
                        arr[n++] = 0xd;
                        arr[n++] = 0xff;        /* these subpages */
                        arr[3] = n - 4;
                        break;
                case 0x2f:      /* Informational exceptions subpages */
                        n = 4;
                        arr[n++] = 0x2f;
                        arr[n++] = 0x0;         /* Informational exceptions */
                        arr[n++] = 0x2f;
                        arr[n++] = 0xff;        /* these subpages */
                        arr[3] = n - 4;
                        break;
                default:
                        mk_sense_invalid_fld(scp, SDEB_IN_CDB, 2, 5);
                        return check_condition_result;
                }
        } else if (subpcode > 0) {
                arr[0] |= 0x40;
                arr[1] = subpcode;
                if (pcode == 0xd && subpcode == 1)
                        arr[3] = resp_env_rep_l_spg(arr + 4);
                else {
                        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_t(u32, get_unaligned_be16(arr + 2) + 4, alloc_len);
        return fill_from_dev_buffer(scp, arr,
                    min_t(u32, len, SDEBUG_MAX_INQ_ARR_SZ));
}

static inline bool sdebug_dev_is_zoned(struct sdebug_dev_info *devip)
{
        return devip->nr_zones != 0;
}

static struct sdeb_zone_state *zbc_zone(struct sdebug_dev_info *devip,
                                        unsigned long long lba)
{
        u32 zno = lba >> devip->zsize_shift;
        struct sdeb_zone_state *zsp;

        if (devip->zcap == devip->zsize || zno < devip->nr_conv_zones)
                return &devip->zstate[zno];

        /*
         * If the zone capacity is less than the zone size, adjust for gap
         * zones.
         */
        zno = 2 * zno - devip->nr_conv_zones;
        WARN_ONCE(zno >= devip->nr_zones, "%u > %u\n", zno, devip->nr_zones);
        zsp = &devip->zstate[zno];
        if (lba >= zsp->z_start + zsp->z_size)
                zsp++;
        WARN_ON_ONCE(lba >= zsp->z_start + zsp->z_size);
        return zsp;
}

static inline bool zbc_zone_is_conv(struct sdeb_zone_state *zsp)
{
        return zsp->z_type == ZBC_ZTYPE_CNV;
}

static inline bool zbc_zone_is_gap(struct sdeb_zone_state *zsp)
{
        return zsp->z_type == ZBC_ZTYPE_GAP;
}

static inline bool zbc_zone_is_seq(struct sdeb_zone_state *zsp)
{
        return !zbc_zone_is_conv(zsp) && !zbc_zone_is_gap(zsp);
}

static void zbc_close_zone(struct sdebug_dev_info *devip,
                           struct sdeb_zone_state *zsp)
{
        enum sdebug_z_cond zc;

        if (!zbc_zone_is_seq(zsp))
                return;

        zc = zsp->z_cond;
        if (!(zc == ZC2_IMPLICIT_OPEN || zc == ZC3_EXPLICIT_OPEN))
                return;

        if (zc == ZC2_IMPLICIT_OPEN)
                devip->nr_imp_open--;
        else
                devip->nr_exp_open--;

        if (zsp->z_wp == zsp->z_start) {
                zsp->z_cond = ZC1_EMPTY;
        } else {
                zsp->z_cond = ZC4_CLOSED;
                devip->nr_closed++;
        }
}

static void zbc_close_imp_open_zone(struct sdebug_dev_info *devip)
{
        struct sdeb_zone_state *zsp = &devip->zstate[0];
        unsigned int i;

        for (i = 0; i < devip->nr_zones; i++, zsp++) {
                if (zsp->z_cond == ZC2_IMPLICIT_OPEN) {
                        zbc_close_zone(devip, zsp);
                        return;
                }
        }
}

static void zbc_open_zone(struct sdebug_dev_info *devip,
                          struct sdeb_zone_state *zsp, bool explicit)
{
        enum sdebug_z_cond zc;

        if (!zbc_zone_is_seq(zsp))
                return;

        zc = zsp->z_cond;
        if ((explicit && zc == ZC3_EXPLICIT_OPEN) ||
            (!explicit && zc == ZC2_IMPLICIT_OPEN))
                return;

        /* Close an implicit open zone if necessary */
        if (explicit && zsp->z_cond == ZC2_IMPLICIT_OPEN)
                zbc_close_zone(devip, zsp);
        else if (devip->max_open &&
                 devip->nr_imp_open + devip->nr_exp_open >= devip->max_open)
                zbc_close_imp_open_zone(devip);

        if (zsp->z_cond == ZC4_CLOSED)
                devip->nr_closed--;
        if (explicit) {
                zsp->z_cond = ZC3_EXPLICIT_OPEN;
                devip->nr_exp_open++;
        } else {
                zsp->z_cond = ZC2_IMPLICIT_OPEN;
                devip->nr_imp_open++;
        }
}

static inline void zbc_set_zone_full(struct sdebug_dev_info *devip,
                                     struct sdeb_zone_state *zsp)
{
        switch (zsp->z_cond) {
        case ZC2_IMPLICIT_OPEN:
                devip->nr_imp_open--;
                break;
        case ZC3_EXPLICIT_OPEN:
                devip->nr_exp_open--;
                break;
        default:
                WARN_ONCE(true, "Invalid zone %llu condition %x\n",
                          zsp->z_start, zsp->z_cond);
                break;
        }
        zsp->z_cond = ZC5_FULL;
}

static void zbc_inc_wp(struct sdebug_dev_info *devip,
                       unsigned long long lba, unsigned int num)
{
        struct sdeb_zone_state *zsp = zbc_zone(devip, lba);
        unsigned long long n, end, zend = zsp->z_start + zsp->z_size;

        if (!zbc_zone_is_seq(zsp))
                return;

        if (zsp->z_type == ZBC_ZTYPE_SWR) {
                zsp->z_wp += num;
                if (zsp->z_wp >= zend)
                        zbc_set_zone_full(devip, zsp);
                return;
        }

        while (num) {
                if (lba != zsp->z_wp)
                        zsp->z_non_seq_resource = true;

                end = lba + num;
                if (end >= zend) {
                        n = zend - lba;
                        zsp->z_wp = zend;
                } else if (end > zsp->z_wp) {
                        n = num;
                        zsp->z_wp = end;
                } else {
                        n = num;
                }
                if (zsp->z_wp >= zend)
                        zbc_set_zone_full(devip, zsp);

                num -= n;
                lba += n;
                if (num) {
                        zsp++;
                        zend = zsp->z_start + zsp->z_size;
                }
        }
}

static int check_zbc_access_params(struct scsi_cmnd *scp,
                        unsigned long long lba, unsigned int num, bool write)
{
        struct scsi_device *sdp = scp->device;
        struct sdebug_dev_info *devip = (struct sdebug_dev_info *)sdp->hostdata;
        struct sdeb_zone_state *zsp = zbc_zone(devip, lba);
        struct sdeb_zone_state *zsp_end = zbc_zone(devip, lba + num - 1);

        if (!write) {
                if (devip->zmodel == BLK_ZONED_HA)
                        return 0;
                /* For host-managed, reads cannot cross zone types boundaries */
                if (zsp->z_type != zsp_end->z_type) {
                        mk_sense_buffer(scp, ILLEGAL_REQUEST,
                                        LBA_OUT_OF_RANGE,
                                        READ_INVDATA_ASCQ);
                        return check_condition_result;
                }
                return 0;
        }

        /* Writing into a gap zone is not allowed */
        if (zbc_zone_is_gap(zsp)) {
                mk_sense_buffer(scp, ILLEGAL_REQUEST, LBA_OUT_OF_RANGE,
                                ATTEMPT_ACCESS_GAP);
                return check_condition_result;
        }

        /* No restrictions for writes within conventional zones */
        if (zbc_zone_is_conv(zsp)) {
                if (!zbc_zone_is_conv(zsp_end)) {
                        mk_sense_buffer(scp, ILLEGAL_REQUEST,
                                        LBA_OUT_OF_RANGE,
                                        WRITE_BOUNDARY_ASCQ);
                        return check_condition_result;
                }
                return 0;
        }

        if (zsp->z_type == ZBC_ZTYPE_SWR) {
                /* Writes cannot cross sequential zone boundaries */
                if (zsp_end != zsp) {
                        mk_sense_buffer(scp, ILLEGAL_REQUEST,
                                        LBA_OUT_OF_RANGE,
                                        WRITE_BOUNDARY_ASCQ);
                        return check_condition_result;
                }
                /* Cannot write full zones */
                if (zsp->z_cond == ZC5_FULL) {
                        mk_sense_buffer(scp, ILLEGAL_REQUEST,
                                        INVALID_FIELD_IN_CDB, 0);
                        return check_condition_result;
                }
                /* Writes must be aligned to the zone WP */
                if (lba != zsp->z_wp) {
                        mk_sense_buffer(scp, ILLEGAL_REQUEST,
                                        LBA_OUT_OF_RANGE,
                                        UNALIGNED_WRITE_ASCQ);
                        return check_condition_result;
                }
        }

        /* Handle implicit open of closed and empty zones */
        if (zsp->z_cond == ZC1_EMPTY || zsp->z_cond == ZC4_CLOSED) {
                if (devip->max_open &&
                    devip->nr_exp_open >= devip->max_open) {
                        mk_sense_buffer(scp, DATA_PROTECT,
                                        INSUFF_RES_ASC,
                                        INSUFF_ZONE_ASCQ);
                        return check_condition_result;
                }
                zbc_open_zone(devip, zsp, false);
        }

        return 0;
}

static inline int check_device_access_params
                        (struct scsi_cmnd *scp, unsigned long long lba,
                         unsigned int num, bool write)
{
        struct scsi_device *sdp = scp->device;
        struct sdebug_dev_info *devip = (struct sdebug_dev_info *)sdp->hostdata;

        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;
        }
        if (sdebug_dev_is_zoned(devip))
                return check_zbc_access_params(scp, lba, num, write);

        return 0;
}

/*
 * Note: if BUG_ON() fires it usually indicates a problem with the parser
 * tables. Perhaps a missing F_FAKE_RW or FF_MEDIA_IO flag. Response functions
 * that access any of the "stores" in struct sdeb_store_info should call this
 * function with bug_if_fake_rw set to true.
 */
static inline struct sdeb_store_info *devip2sip(struct sdebug_dev_info *devip,
                                                bool bug_if_fake_rw)
{
        if (sdebug_fake_rw) {
                BUG_ON(bug_if_fake_rw); /* See note above */
                return NULL;
        }
        return xa_load(per_store_ap, devip->sdbg_host->si_idx);
}

/* Returns number of bytes copied or -1 if error. */
static int do_device_access(struct sdeb_store_info *sip, struct scsi_cmnd *scp,
                            u32 sg_skip, u64 lba, u32 num, bool do_write)
{
        int ret;
        u64 block, rest = 0;
        enum dma_data_direction dir;
        struct scsi_data_buffer *sdb = &scp->sdb;
        u8 *fsp;

        if (do_write) {
                dir = DMA_TO_DEVICE;
                write_since_sync = true;
        } else {
                dir = DMA_FROM_DEVICE;
        }

        if (!sdb->length || !sip)
                return 0;
        if (scp->sc_data_direction != dir)
                return -1;
        fsp = sip->storep;

        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,
                   fsp + (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,
                            fsp, rest * sdebug_sector_size,
                            sg_skip + ((num - rest) * sdebug_sector_size),
                            do_write);
        }

        return ret;
}

/* Returns number of bytes copied or -1 if error. */
static int do_dout_fetch(struct scsi_cmnd *scp, u32 num, u8 *doutp)
{
        struct scsi_data_buffer *sdb = &scp->sdb;

        if (!sdb->length)
                return 0;
        if (scp->sc_data_direction != DMA_TO_DEVICE)
                return -1;
        return sg_copy_buffer(sdb->table.sgl, sdb->table.nents, doutp,
                              num * sdebug_sector_size, 0, true);
}

/* If sip->storep+lba compares equal to arr(num), then copy top half of
 * arr into sip->storep+lba and return true. If comparison fails then
 * return false. */
static bool comp_write_worker(struct sdeb_store_info *sip, u64 lba, u32 num,
                              const u8 *arr, bool compare_only)
{
        bool res;
        u64 block, rest = 0;
        u32 store_blks = sdebug_store_sectors;
        u32 lb_size = sdebug_sector_size;
        u8 *fsp = sip->storep;

        block = do_div(lba, store_blks);
        if (block + num > store_blks)
                rest = block + num - store_blks;

        res = !memcmp(fsp + (block * lb_size), arr, (num - rest) * lb_size);
        if (!res)
                return res;
        if (rest)
                res = memcmp(fsp, arr + ((num - rest) * lb_size),
                             rest * lb_size);
        if (!res)
                return res;
        if (compare_only)
                return true;
        arr += num * lb_size;
        memcpy(fsp + (block * lb_size), arr, (num - rest) * lb_size);
        if (rest)
                memcpy(fsp, 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 *scp, sector_t sector,
                          unsigned int sectors, bool read)
{
        size_t resid;
        void *paddr;
        struct sdeb_store_info *sip = devip2sip((struct sdebug_dev_info *)
                                                scp->device->hostdata, true);
        struct t10_pi_tuple *dif_storep = sip->dif_storep;
        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(scp),
                       scsi_prot_sg_count(scp), SG_MITER_ATOMIC |
                       (read ? SG_MITER_TO_SG : SG_MITER_FROM_SG));

        while (sg_miter_next(&miter) && resid > 0) {
                size_t len = min_t(size_t, miter.length, resid);
                void *start = dif_store(sip, 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 *scp, sector_t start_sec,
                            unsigned int sectors, u32 ei_lba)
{
        int ret = 0;
        unsigned int i;
        sector_t sector;
        struct sdeb_store_info *sip = devip2sip((struct sdebug_dev_info *)
                                                scp->device->hostdata, true);
        struct t10_pi_tuple *sdt;

        for (i = 0; i < sectors; i++, ei_lba++) {
                sector = start_sec + i;
                sdt = dif_store(sip, sector);

                if (sdt->app_tag == cpu_to_be16(0xffff))
                        continue;

                /*
                 * Because scsi_debug acts as both initiator and
                 * target we proceed to verify the PI even if
                 * RDPROTECT=3. This is done so the "initiator" knows
                 * which type of error to return. Otherwise we would
                 * have to iterate over the PI twice.
                 */
                if (scp->cmnd[1] >> 5) { /* RDPROTECT */
                        ret = dif_verify(sdt, lba2fake_store(sip, sector),
                                         sector, ei_lba);
                        if (ret) {
                                dif_errors++;
                                break;
                        }
                }
        }

        dif_copy_prot(scp, start_sec, sectors, true);
        dix_reads++;

        return ret;
}

static inline void
sdeb_read_lock(struct sdeb_store_info *sip)
{
        if (sdebug_no_rwlock) {
                if (sip)
                        __acquire(&sip->macc_lck);
                else
                        __acquire(&sdeb_fake_rw_lck);
        } else {
                if (sip)
                        read_lock(&sip->macc_lck);
                else
                        read_lock(&sdeb_fake_rw_lck);
        }
}

static inline void
sdeb_read_unlock(struct sdeb_store_info *sip)
{
        if (sdebug_no_rwlock) {
                if (sip)
                        __release(&sip->macc_lck);
                else
                        __release(&sdeb_fake_rw_lck);
        } else {
                if (sip)
                        read_unlock(&sip->macc_lck);
                else
                        read_unlock(&sdeb_fake_rw_lck);
        }
}

static inline void
sdeb_write_lock(struct sdeb_store_info *sip)
{
        if (sdebug_no_rwlock) {
                if (sip)
                        __acquire(&sip->macc_lck);
                else
                        __acquire(&sdeb_fake_rw_lck);
        } else {
                if (sip)
                        write_lock(&sip->macc_lck);
                else
                        write_lock(&sdeb_fake_rw_lck);
        }
}

static inline void
sdeb_write_unlock(struct sdeb_store_info *sip)
{
        if (sdebug_no_rwlock) {
                if (sip)
                        __release(&sip->macc_lck);
                else
                        __release(&sdeb_fake_rw_lck);
        } else {
                if (sip)
                        write_unlock(&sip->macc_lck);
                else
                        write_unlock(&sdeb_fake_rw_lck);
        }
}

static int resp_read_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
{
        bool check_prot;
        u32 num;
        u32 ei_lba;
        int ret;
        u64 lba;
        struct sdeb_store_info *sip = devip2sip(devip, true);
        u8 *cmd = scp->cmnd;

        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_opts & SDEBUG_OPT_SHORT_TRANSFER) &&
                     atomic_read(&sdeb_inject_pending))) {
                num /= 2;
                atomic_set(&sdeb_inject_pending, 0);
        }

        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;
        }

        sdeb_read_lock(sip);

        /* DIX + T10 DIF */
        if (unlikely(sdebug_dix && scsi_prot_sg_count(scp))) {
                switch (prot_verify_read(scp, lba, num, ei_lba)) {
                case 1: /* Guard tag error */
                        if (cmd[1] >> 5 != 3) { /* RDPROTECT != 3 */
                                sdeb_read_unlock(sip);
                                mk_sense_buffer(scp, ABORTED_COMMAND, 0x10, 1);
                                return check_condition_result;
                        } else if (scp->prot_flags & SCSI_PROT_GUARD_CHECK) {
                                sdeb_read_unlock(sip);
                                mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10, 1);
                                return illegal_condition_result;
                        }
                        break;
                case 3: /* Reference tag error */
                        if (cmd[1] >> 5 != 3) { /* RDPROTECT != 3 */
                                sdeb_read_unlock(sip);
                                mk_sense_buffer(scp, ABORTED_COMMAND, 0x10, 3);
                                return check_condition_result;
                        } else if (scp->prot_flags & SCSI_PROT_REF_CHECK) {
                                sdeb_read_unlock(sip);
                                mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10, 3);
                                return illegal_condition_result;
                        }
                        break;
                }
        }

        ret = do_device_access(sip, scp, 0, lba, num, false);
        sdeb_read_unlock(sip);
        if (unlikely(ret == -1))
                return DID_ERROR << 16;

        scsi_set_resid(scp, scsi_bufflen(scp) - ret);

        if (unlikely((sdebug_opts & SDEBUG_OPT_RECOV_DIF_DIX) &&
                     atomic_read(&sdeb_inject_pending))) {
                if (sdebug_opts & SDEBUG_OPT_RECOVERED_ERR) {
                        mk_sense_buffer(scp, RECOVERED_ERROR, THRESHOLD_EXCEEDED, 0);
                        atomic_set(&sdeb_inject_pending, 0);
                        return check_condition_result;
                } else if (sdebug_opts & SDEBUG_OPT_DIF_ERR) {
                        /* Logical block guard check failed */
                        mk_sense_buffer(scp, ABORTED_COMMAND, 0x10, 1);
                        atomic_set(&sdeb_inject_pending, 0);
                        return illegal_condition_result;
                } else if (SDEBUG_OPT_DIX_ERR & sdebug_opts) {
                        mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10, 1);
                        atomic_set(&sdeb_inject_pending, 0);
                        return illegal_condition_result;
                }
        }
        return 0;
}

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;

                        if (SCpnt->cmnd[1] >> 5 != 3) { /* WRPROTECT */
                                ret = dif_verify(sdt, daddr, sector, ei_lba);
                                if (ret)
                                        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(struct sdeb_store_info *sip, 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, sip->map_storep);

        if (mapped)
                next = find_next_zero_bit(sip->map_storep, map_size, index);
        else
                next = find_next_bit(sip->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(struct sdeb_store_info *sip, 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, sip->map_storep);

                lba = map_index_to_lba(index + 1);
        }
}

static void unmap_region(struct sdeb_store_info *sip, sector_t lba,
                         unsigned int len)
{
        sector_t end = lba + len;
        u8 *fsp = sip->storep;

        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, sip->map_storep);
                        if (sdebug_lbprz) {  /* for LBPRZ=2 return 0xff_s */
                                memset(fsp + lba * sdebug_sector_size,
                                       (sdebug_lbprz & 1) ? 0 : 0xff,
                                       sdebug_sector_size *
                                       sdebug_unmap_granularity);
                        }
                        if (sip->dif_storep) {
                                memset(sip->dif_storep + lba, 0xff,
                                       sizeof(*sip->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)
{
        bool check_prot;
        u32 num;
        u32 ei_lba;
        int ret;
        u64 lba;
        struct sdeb_store_info *sip = devip2sip(devip, true);
        u8 *cmd = scp->cmnd;

        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");
        }

        sdeb_write_lock(sip);
        ret = check_device_access_params(scp, lba, num, true);
        if (ret) {
                sdeb_write_unlock(sip);
                return ret;
        }

        /* DIX + T10 DIF */
        if (unlikely(sdebug_dix && scsi_prot_sg_count(scp))) {
                switch (prot_verify_write(scp, lba, num, ei_lba)) {
                case 1: /* Guard tag error */
                        if (scp->prot_flags & SCSI_PROT_GUARD_CHECK) {
                                sdeb_write_unlock(sip);
                                mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10, 1);
                                return illegal_condition_result;
                        } else if (scp->cmnd[1] >> 5 != 3) { /* WRPROTECT != 3 */
                                sdeb_write_unlock(sip);
                                mk_sense_buffer(scp, ABORTED_COMMAND, 0x10, 1);
                                return check_condition_result;
                        }
                        break;
                case 3: /* Reference tag error */
                        if (scp->prot_flags & SCSI_PROT_REF_CHECK) {
                                sdeb_write_unlock(sip);
                                mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10, 3);
                                return illegal_condition_result;
                        } else if (scp->cmnd[1] >> 5 != 3) { /* WRPROTECT != 3 */
                                sdeb_write_unlock(sip);
                                mk_sense_buffer(scp, ABORTED_COMMAND, 0x10, 3);
                                return check_condition_result;
                        }
                        break;
                }
        }

        ret = do_device_access(sip, scp, 0, lba, num, true);
        if (unlikely(scsi_debug_lbp()))
                map_region(sip, lba, num);
        /* If ZBC zone then bump its write pointer */
        if (sdebug_dev_is_zoned(devip))
                zbc_inc_wp(devip, lba, num);
        sdeb_write_unlock(sip);
        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_opts & SDEBUG_OPT_RECOV_DIF_DIX) &&
                     atomic_read(&sdeb_inject_pending))) {
                if (sdebug_opts & SDEBUG_OPT_RECOVERED_ERR) {
                        mk_sense_buffer(scp, RECOVERED_ERROR, THRESHOLD_EXCEEDED, 0);
                        atomic_set(&sdeb_inject_pending, 0);
                        return check_condition_result;
                } else if (sdebug_opts & SDEBUG_OPT_DIF_ERR) {
                        /* Logical block guard check failed */
                        mk_sense_buffer(scp, ABORTED_COMMAND, 0x10, 1);
                        atomic_set(&sdeb_inject_pending, 0);
                        return illegal_condition_result;
                } else if (sdebug_opts & SDEBUG_OPT_DIX_ERR) {
                        mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10, 1);
                        atomic_set(&sdeb_inject_pending, 0);
                        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;
        struct sdeb_store_info *sip = devip2sip(devip, true);
        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;
        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 | __GFP_NOWARN);
        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;
        }

        sdeb_write_lock(sip);
        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(sip, scp, sg_off, lba, num, true);
                /* If ZBC zone then bump its write pointer */
                if (sdebug_dev_is_zoned(devip))
                        zbc_inc_wp(devip, lba, num);
                if (unlikely(scsi_debug_lbp()))
                        map_region(sip, 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_opts & SDEBUG_OPT_RECOV_DIF_DIX) &&
                             atomic_read(&sdeb_inject_pending))) {
                        if (sdebug_opts & SDEBUG_OPT_RECOVERED_ERR) {
                                mk_sense_buffer(scp, RECOVERED_ERROR, THRESHOLD_EXCEEDED, 0);
                                atomic_set(&sdeb_inject_pending, 0);
                                ret = check_condition_result;
                                goto err_out_unlock;
                        } else if (sdebug_opts & SDEBUG_OPT_DIF_ERR) {
                                /* Logical block guard check failed */
                                mk_sense_buffer(scp, ABORTED_COMMAND, 0x10, 1);
                                atomic_set(&sdeb_inject_pending, 0);
                                ret = illegal_condition_result;
                                goto err_out_unlock;
                        } else if (sdebug_opts & SDEBUG_OPT_DIX_ERR) {
                                mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10, 1);
                                atomic_set(&sdeb_inject_pending, 0);
                                ret = illegal_condition_result;
                                goto err_out_unlock;
                        }
                }
                sg_off += num_by;
                cum_lb += num;
        }
        ret = 0;
err_out_unlock:
        sdeb_write_unlock(sip);
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)
{
        struct scsi_device *sdp = scp->device;
        struct sdebug_dev_info *devip = (struct sdebug_dev_info *)sdp->hostdata;
        unsigned long long i;
        u64 block, lbaa;
        u32 lb_size = sdebug_sector_size;
        int ret;
        struct sdeb_store_info *sip = devip2sip((struct sdebug_dev_info *)
                                                scp->device->hostdata, true);
        u8 *fs1p;
        u8 *fsp;

        sdeb_write_lock(sip);

        ret = check_device_access_params(scp, lba, num, true);
        if (ret) {
                sdeb_write_unlock(sip);
                return ret;
        }

        if (unmap && scsi_debug_lbp()) {
                unmap_region(sip, 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 */
        fsp = sip->storep;
        fs1p = fsp + (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) {
                sdeb_write_unlock(sip);
                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(fsp + (block * lb_size), fs1p, lb_size);
        }
        if (scsi_debug_lbp())
                map_region(sip, lba, num);
        /* If ZBC zone then bump its write pointer */
        if (sdebug_dev_is_zoned(devip))
                zbc_inc_wp(devip, lba, num);
out:
        sdeb_write_unlock(sip);

        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;
        struct sdeb_store_info *sip = devip2sip(devip, true);
        u64 lba;
        u32 dnum;
        u32 lb_size = sdebug_sector_size;
        u8 num;
        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;
        }

        sdeb_write_lock(sip);

        ret = do_dout_fetch(scp, dnum, arr);
        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(sip, lba, num, arr, false)) {
                mk_sense_buffer(scp, MISCOMPARE, MISCOMPARE_VERIFY_ASC, 0);
                retval = check_condition_result;
                goto cleanup;
        }
        if (scsi_debug_lbp())
                map_region(sip, lba, num);
cleanup:
        sdeb_write_unlock(sip);
        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;
        struct sdeb_store_info *sip = devip2sip(devip, true);
        unsigned int i, payload_len, descriptors;
        int ret;

        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];

        sdeb_write_lock(sip);

        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(sip, lba, num);
        }

        ret = 0;

out:
        sdeb_write_unlock(sip);
        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;
        int ret;
        u8 arr[SDEBUG_GET_LBA_STATUS_LEN];

        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()) {
                struct sdeb_store_info *sip = devip2sip(devip, true);

                mapped = map_state(sip, 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;
}

/*
 * Assuming the LBA+num_blocks is not out-of-range, this function will return
 * CONDITION MET if the specified blocks will/have fitted in the cache, and
 * a GOOD status otherwise. Model a disk with a big cache and yield
 * CONDITION MET. Actually tries to bring range in main memory into the
 * cache associated with the CPU(s).
 */
static int resp_pre_fetch(struct scsi_cmnd *scp,
                          struct sdebug_dev_info *devip)
{
        int res = 0;
        u64 lba;
        u64 block, rest = 0;
        u32 nblks;
        u8 *cmd = scp->cmnd;
        struct sdeb_store_info *sip = devip2sip(devip, true);
        u8 *fsp = sip->storep;

        if (cmd[0] == PRE_FETCH) {      /* 10 byte cdb */
                lba = get_unaligned_be32(cmd + 2);
                nblks = get_unaligned_be16(cmd + 7);
        } else {                        /* PRE-FETCH(16) */
                lba = get_unaligned_be64(cmd + 2);
                nblks = get_unaligned_be32(cmd + 10);
        }
        if (lba + nblks > sdebug_capacity) {
                mk_sense_buffer(scp, ILLEGAL_REQUEST, LBA_OUT_OF_RANGE, 0);
                return check_condition_result;
        }
        if (!fsp)
                goto fini;
        /* PRE-FETCH spec says nothing about LBP or PI so skip them */
        block = do_div(lba, sdebug_store_sectors);
        if (block + nblks > sdebug_store_sectors)
                rest = block + nblks - sdebug_store_sectors;

        /* Try to bring the PRE-FETCH range into CPU's cache */
        sdeb_read_lock(sip);
        prefetch_range(fsp + (sdebug_sector_size * block),
                       (nblks - rest) * sdebug_sector_size);
        if (rest)
                prefetch_range(fsp, rest * sdebug_sector_size);
        sdeb_read_unlock(sip);
fini:
        if (cmd[1] & 0x2)
                res = SDEG_RES_IMMED_MASK;
        return res | condition_met_result;
}

#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 (lun > 1 && sdebug_lun_am == SAM_LUN_AM_FLAT)
                                lun_p->scsi_lun[0] |= 0x40;
                }
                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 int resp_verify(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
{
        bool is_bytchk3 = false;
        u8 bytchk;
        int ret, j;
        u32 vnum, a_num, off;
        const u32 lb_size = sdebug_sector_size;
        u64 lba;
        u8 *arr;
        u8 *cmd = scp->cmnd;
        struct sdeb_store_info *sip = devip2sip(devip, true);

        bytchk = (cmd[1] >> 1) & 0x3;
        if (bytchk == 0) {
                return 0;       /* always claim internal verify okay */
        } else if (bytchk == 2) {
                mk_sense_invalid_fld(scp, SDEB_IN_CDB, 2, 2);
                return check_condition_result;
        } else if (bytchk == 3) {
                is_bytchk3 = true;      /* 1 block sent, compared repeatedly */
        }
        switch (cmd[0]) {
        case VERIFY_16:
                lba = get_unaligned_be64(cmd + 2);
                vnum = get_unaligned_be32(cmd + 10);
                break;
        case VERIFY:            /* is VERIFY(10) */
                lba = get_unaligned_be32(cmd + 2);
                vnum = get_unaligned_be16(cmd + 7);
                break;
        default:
                mk_sense_invalid_opcode(scp);
                return check_condition_result;
        }
        if (vnum == 0)
                return 0;       /* not an error */
        a_num = is_bytchk3 ? 1 : vnum;
        /* Treat following check like one for read (i.e. no write) access */
        ret = check_device_access_params(scp, lba, a_num, false);
        if (ret)
                return ret;

        arr = kcalloc(lb_size, vnum, GFP_ATOMIC | __GFP_NOWARN);
        if (!arr) {
                mk_sense_buffer(scp, ILLEGAL_REQUEST, INSUFF_RES_ASC,
                                INSUFF_RES_ASCQ);
                return check_condition_result;
        }
        /* Not changing store, so only need read access */
        sdeb_read_lock(sip);

        ret = do_dout_fetch(scp, a_num, arr);
        if (ret == -1) {
                ret = DID_ERROR << 16;
                goto cleanup;
        } else if (sdebug_verbose && (ret < (a_num * lb_size))) {
                sdev_printk(KERN_INFO, scp->device,
                            "%s: %s: cdb indicated=%u, IO sent=%d bytes\n",
                            my_name, __func__, a_num * lb_size, ret);
        }
        if (is_bytchk3) {
                for (j = 1, off = lb_size; j < vnum; ++j, off += lb_size)
                        memcpy(arr + off, arr, lb_size);
        }
        ret = 0;
        if (!comp_write_worker(sip, lba, vnum, arr, true)) {
                mk_sense_buffer(scp, MISCOMPARE, MISCOMPARE_VERIFY_ASC, 0);
                ret = check_condition_result;
                goto cleanup;
        }
cleanup:
        sdeb_read_unlock(sip);
        kfree(arr);
        return ret;
}

#define RZONES_DESC_HD 64

/* Report zones depending on start LBA and reporting options */
static int resp_report_zones(struct scsi_cmnd *scp,
                             struct sdebug_dev_info *devip)
{
        unsigned int rep_max_zones, nrz = 0;
        int ret = 0;
        u32 alloc_len, rep_opts, rep_len;
        bool partial;
        u64 lba, zs_lba;
        u8 *arr = NULL, *desc;
        u8 *cmd = scp->cmnd;
        struct sdeb_zone_state *zsp = NULL;
        struct sdeb_store_info *sip = devip2sip(devip, false);

        if (!sdebug_dev_is_zoned(devip)) {
                mk_sense_invalid_opcode(scp);
                return check_condition_result;
        }
        zs_lba = get_unaligned_be64(cmd + 2);
        alloc_len = get_unaligned_be32(cmd + 10);
        if (alloc_len == 0)
                return 0;       /* not an error */
        rep_opts = cmd[14] & 0x3f;
        partial = cmd[14] & 0x80;

        if (zs_lba >= sdebug_capacity) {
                mk_sense_buffer(scp, ILLEGAL_REQUEST, LBA_OUT_OF_RANGE, 0);
                return check_condition_result;
        }

        rep_max_zones = (alloc_len - 64) >> ilog2(RZONES_DESC_HD);

        arr = kzalloc(alloc_len, GFP_ATOMIC | __GFP_NOWARN);
        if (!arr) {
                mk_sense_buffer(scp, ILLEGAL_REQUEST, INSUFF_RES_ASC,
                                INSUFF_RES_ASCQ);
                return check_condition_result;
        }

        sdeb_read_lock(sip);

        desc = arr + 64;
        for (lba = zs_lba; lba < sdebug_capacity;
             lba = zsp->z_start + zsp->z_size) {
                if (WARN_ONCE(zbc_zone(devip, lba) == zsp, "lba = %llu\n", lba))
                        break;
                zsp = zbc_zone(devip, lba);
                switch (rep_opts) {
                case 0x00:
                        /* All zones */
                        break;
                case 0x01:
                        /* Empty zones */
                        if (zsp->z_cond != ZC1_EMPTY)
                                continue;
                        break;
                case 0x02:
                        /* Implicit open zones */
                        if (zsp->z_cond != ZC2_IMPLICIT_OPEN)
                                continue;
                        break;
                case 0x03:
                        /* Explicit open zones */
                        if (zsp->z_cond != ZC3_EXPLICIT_OPEN)
                                continue;
                        break;
                case 0x04:
                        /* Closed zones */
                        if (zsp->z_cond != ZC4_CLOSED)
                                continue;
                        break;
                case 0x05:
                        /* Full zones */
                        if (zsp->z_cond != ZC5_FULL)
                                continue;
                        break;
                case 0x06:
                case 0x07:
                case 0x10:
                        /*
                         * Read-only, offline, reset WP recommended are
                         * not emulated: no zones to report;
                         */
                        continue;
                case 0x11:
                        /* non-seq-resource set */
                        if (!zsp->z_non_seq_resource)
                                continue;
                        break;
                case 0x3e:
                        /* All zones except gap zones. */
                        if (zbc_zone_is_gap(zsp))
                                continue;
                        break;
                case 0x3f:
                        /* Not write pointer (conventional) zones */
                        if (zbc_zone_is_seq(zsp))
                                continue;
                        break;
                default:
                        mk_sense_buffer(scp, ILLEGAL_REQUEST,
                                        INVALID_FIELD_IN_CDB, 0);
                        ret = check_condition_result;
                        goto fini;
                }

                if (nrz < rep_max_zones) {
                        /* Fill zone descriptor */
                        desc[0] = zsp->z_type;
                        desc[1] = zsp->z_cond << 4;
                        if (zsp->z_non_seq_resource)
                                desc[1] |= 1 << 1;
                        put_unaligned_be64((u64)zsp->z_size, desc + 8);
                        put_unaligned_be64((u64)zsp->z_start, desc + 16);
                        put_unaligned_be64((u64)zsp->z_wp, desc + 24);
                        desc += 64;
                }

                if (partial && nrz >= rep_max_zones)
                        break;

                nrz++;
        }

        /* Report header */
        /* Zone list length. */
        put_unaligned_be32(nrz * RZONES_DESC_HD, arr + 0);
        /* Maximum LBA */
        put_unaligned_be64(sdebug_capacity - 1, arr + 8);
        /* Zone starting LBA granularity. */
        if (devip->zcap < devip->zsize)
                put_unaligned_be64(devip->zsize, arr + 16);

        rep_len = (unsigned long)desc - (unsigned long)arr;
        ret = fill_from_dev_buffer(scp, arr, min_t(u32, alloc_len, rep_len));

fini:
        sdeb_read_unlock(sip);
        kfree(arr);
        return ret;
}

/* Logic transplanted from tcmu-runner, file_zbc.c */
static void zbc_open_all(struct sdebug_dev_info *devip)
{
        struct sdeb_zone_state *zsp = &devip->zstate[0];
        unsigned int i;

        for (i = 0; i < devip->nr_zones; i++, zsp++) {
                if (zsp->z_cond == ZC4_CLOSED)
                        zbc_open_zone(devip, &devip->zstate[i], true);
        }
}

static int resp_open_zone(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
{
        int res = 0;
        u64 z_id;
        enum sdebug_z_cond zc;
        u8 *cmd = scp->cmnd;
        struct sdeb_zone_state *zsp;
        bool all = cmd[14] & 0x01;
        struct sdeb_store_info *sip = devip2sip(devip, false);

        if (!sdebug_dev_is_zoned(devip)) {
                mk_sense_invalid_opcode(scp);
                return check_condition_result;
        }

        sdeb_write_lock(sip);

        if (all) {
                /* Check if all closed zones can be open */
                if (devip->max_open &&
                    devip->nr_exp_open + devip->nr_closed > devip->max_open) {
                        mk_sense_buffer(scp, DATA_PROTECT, INSUFF_RES_ASC,
                                        INSUFF_ZONE_ASCQ);
                        res = check_condition_result;
                        goto fini;
                }
                /* Open all closed zones */
                zbc_open_all(devip);
                goto fini;
        }

        /* Open the specified zone */
        z_id = get_unaligned_be64(cmd + 2);
        if (z_id >= sdebug_capacity) {
                mk_sense_buffer(scp, ILLEGAL_REQUEST, LBA_OUT_OF_RANGE, 0);
                res = check_condition_result;
                goto fini;
        }

        zsp = zbc_zone(devip, z_id);
        if (z_id != zsp->z_start) {
                mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0);
                res = check_condition_result;
                goto fini;
        }
        if (zbc_zone_is_conv(zsp)) {
                mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0);
                res = check_condition_result;
                goto fini;
        }

        zc = zsp->z_cond;
        if (zc == ZC3_EXPLICIT_OPEN || zc == ZC5_FULL)
                goto fini;

        if (devip->max_open && devip->nr_exp_open >= devip->max_open) {
                mk_sense_buffer(scp, DATA_PROTECT, INSUFF_RES_ASC,
                                INSUFF_ZONE_ASCQ);
                res = check_condition_result;
                goto fini;
        }

        zbc_open_zone(devip, zsp, true);
fini:
        sdeb_write_unlock(sip);
        return res;
}

static void zbc_close_all(struct sdebug_dev_info *devip)
{
        unsigned int i;

        for (i = 0; i < devip->nr_zones; i++)
                zbc_close_zone(devip, &devip->zstate[i]);
}

static int resp_close_zone(struct scsi_cmnd *scp,
                           struct sdebug_dev_info *devip)
{
        int res = 0;
        u64 z_id;
        u8 *cmd = scp->cmnd;
        struct sdeb_zone_state *zsp;
        bool all = cmd[14] & 0x01;
        struct sdeb_store_info *sip = devip2sip(devip, false);

        if (!sdebug_dev_is_zoned(devip)) {
                mk_sense_invalid_opcode(scp);
                return check_condition_result;
        }

        sdeb_write_lock(sip);

        if (all) {
                zbc_close_all(devip);
                goto fini;
        }

        /* Close specified zone */
        z_id = get_unaligned_be64(cmd + 2);
        if (z_id >= sdebug_capacity) {
                mk_sense_buffer(scp, ILLEGAL_REQUEST, LBA_OUT_OF_RANGE, 0);
                res = check_condition_result;
                goto fini;
        }

        zsp = zbc_zone(devip, z_id);
        if (z_id != zsp->z_start) {
                mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0);
                res = check_condition_result;
                goto fini;
        }
        if (zbc_zone_is_conv(zsp)) {
                mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0);
                res = check_condition_result;
                goto fini;
        }

        zbc_close_zone(devip, zsp);
fini:
        sdeb_write_unlock(sip);
        return res;
}

static void zbc_finish_zone(struct sdebug_dev_info *devip,
                            struct sdeb_zone_state *zsp, bool empty)
{
        enum sdebug_z_cond zc = zsp->z_cond;

        if (zc == ZC4_CLOSED || zc == ZC2_IMPLICIT_OPEN ||
            zc == ZC3_EXPLICIT_OPEN || (empty && zc == ZC1_EMPTY)) {
                if (zc == ZC2_IMPLICIT_OPEN || zc == ZC3_EXPLICIT_OPEN)
                        zbc_close_zone(devip, zsp);
                if (zsp->z_cond == ZC4_CLOSED)
                        devip->nr_closed--;
                zsp->z_wp = zsp->z_start + zsp->z_size;
                zsp->z_cond = ZC5_FULL;
        }
}

static void zbc_finish_all(struct sdebug_dev_info *devip)
{
        unsigned int i;

        for (i = 0; i < devip->nr_zones; i++)
                zbc_finish_zone(devip, &devip->zstate[i], false);
}

static int resp_finish_zone(struct scsi_cmnd *scp,
                            struct sdebug_dev_info *devip)
{
        struct sdeb_zone_state *zsp;
        int res = 0;
        u64 z_id;
        u8 *cmd = scp->cmnd;
        bool all = cmd[14] & 0x01;
        struct sdeb_store_info *sip = devip2sip(devip, false);

        if (!sdebug_dev_is_zoned(devip)) {
                mk_sense_invalid_opcode(scp);
                return check_condition_result;
        }

        sdeb_write_lock(sip);

        if (all) {
                zbc_finish_all(devip);
                goto fini;
        }

        /* Finish the specified zone */
        z_id = get_unaligned_be64(cmd + 2);
        if (z_id >= sdebug_capacity) {
                mk_sense_buffer(scp, ILLEGAL_REQUEST, LBA_OUT_OF_RANGE, 0);
                res = check_condition_result;
                goto fini;
        }

        zsp = zbc_zone(devip, z_id);
        if (z_id != zsp->z_start) {
                mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0);
                res = check_condition_result;
                goto fini;
        }
        if (zbc_zone_is_conv(zsp)) {
                mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0);
                res = check_condition_result;
                goto fini;
        }

        zbc_finish_zone(devip, zsp, true);
fini:
        sdeb_write_unlock(sip);
        return res;
}

static void zbc_rwp_zone(struct sdebug_dev_info *devip,
                         struct sdeb_zone_state *zsp)
{
        enum sdebug_z_cond zc;
        struct sdeb_store_info *sip = devip2sip(devip, false);

        if (!zbc_zone_is_seq(zsp))
                return;

        zc = zsp->z_cond;
        if (zc == ZC2_IMPLICIT_OPEN || zc == ZC3_EXPLICIT_OPEN)
                zbc_close_zone(devip, zsp);

        if (zsp->z_cond == ZC4_CLOSED)
                devip->nr_closed--;

        if (zsp->z_wp > zsp->z_start)
                memset(sip->storep + zsp->z_start * sdebug_sector_size, 0,
                       (zsp->z_wp - zsp->z_start) * sdebug_sector_size);

        zsp->z_non_seq_resource = false;
        zsp->z_wp = zsp->z_start;
        zsp->z_cond = ZC1_EMPTY;
}

static void zbc_rwp_all(struct sdebug_dev_info *devip)
{
        unsigned int i;

        for (i = 0; i < devip->nr_zones; i++)
                zbc_rwp_zone(devip, &devip->zstate[i]);
}

static int resp_rwp_zone(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
{
        struct sdeb_zone_state *zsp;
        int res = 0;
        u64 z_id;
        u8 *cmd = scp->cmnd;
        bool all = cmd[14] & 0x01;
        struct sdeb_store_info *sip = devip2sip(devip, false);

        if (!sdebug_dev_is_zoned(devip)) {
                mk_sense_invalid_opcode(scp);
                return check_condition_result;
        }

        sdeb_write_lock(sip);

        if (all) {
                zbc_rwp_all(devip);
                goto fini;
        }

        z_id = get_unaligned_be64(cmd + 2);
        if (z_id >= sdebug_capacity) {
                mk_sense_buffer(scp, ILLEGAL_REQUEST, LBA_OUT_OF_RANGE, 0);
                res = check_condition_result;
                goto fini;
        }

        zsp = zbc_zone(devip, z_id);
        if (z_id != zsp->z_start) {
                mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0);
                res = check_condition_result;
                goto fini;
        }
        if (zbc_zone_is_conv(zsp)) {
                mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0);
                res = check_condition_result;
                goto fini;
        }

        zbc_rwp_zone(devip, zsp);
fini:
        sdeb_write_unlock(sip);
        return res;
}

static u32 get_tag(struct scsi_cmnd *cmnd)
{
        return blk_mq_unique_tag(scsi_cmd_to_rq(cmnd));
}

/* Queued (deferred) command completions converge here. */
static void sdebug_q_cmd_complete(struct sdebug_defer *sd_dp)
{
        struct sdebug_queued_cmd *sqcp = container_of(sd_dp, struct sdebug_queued_cmd, sd_dp);
        unsigned long flags;
        struct scsi_cmnd *scp = sqcp->scmd;
        struct sdebug_scsi_cmd *sdsc;
        bool aborted;

        if (sdebug_statistics) {
                atomic_inc(&sdebug_completions);
                if (raw_smp_processor_id() != sd_dp->issuing_cpu)
                        atomic_inc(&sdebug_miss_cpus);
        }

        if (!scp) {
                pr_err("scmd=NULL\n");
                goto out;
        }

        sdsc = scsi_cmd_priv(scp);
        spin_lock_irqsave(&sdsc->lock, flags);
        aborted = sd_dp->aborted;
        if (unlikely(aborted))
                sd_dp->aborted = false;
        ASSIGN_QUEUED_CMD(scp, NULL);

        spin_unlock_irqrestore(&sdsc->lock, flags);

        if (aborted) {
                pr_info("bypassing scsi_done() due to aborted cmd, kicking-off EH\n");
                blk_abort_request(scsi_cmd_to_rq(scp));
                goto out;
        }

        scsi_done(scp); /* callback to mid level */
out:
        sdebug_free_queued_cmd(sqcp);
}

/* 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 int sdebug_device_create_zones(struct sdebug_dev_info *devip)
{
        struct sdeb_zone_state *zsp;
        sector_t capacity = get_sdebug_capacity();
        sector_t conv_capacity;
        sector_t zstart = 0;
        unsigned int i;

        /*
         * Set the zone size: if sdeb_zbc_zone_size_mb is not set, figure out
         * a zone size allowing for at least 4 zones on the device. Otherwise,
         * use the specified zone size checking that at least 2 zones can be
         * created for the device.
         */
        if (!sdeb_zbc_zone_size_mb) {
                devip->zsize = (DEF_ZBC_ZONE_SIZE_MB * SZ_1M)
                        >> ilog2(sdebug_sector_size);
                while (capacity < devip->zsize << 2 && devip->zsize >= 2)
                        devip->zsize >>= 1;
                if (devip->zsize < 2) {
                        pr_err("Device capacity too small\n");
                        return -EINVAL;
                }
        } else {
                if (!is_power_of_2(sdeb_zbc_zone_size_mb)) {
                        pr_err("Zone size is not a power of 2\n");
                        return -EINVAL;
                }
                devip->zsize = (sdeb_zbc_zone_size_mb * SZ_1M)
                        >> ilog2(sdebug_sector_size);
                if (devip->zsize >= capacity) {
                        pr_err("Zone size too large for device capacity\n");
                        return -EINVAL;
                }
        }

        devip->zsize_shift = ilog2(devip->zsize);
        devip->nr_zones = (capacity + devip->zsize - 1) >> devip->zsize_shift;

        if (sdeb_zbc_zone_cap_mb == 0) {
                devip->zcap = devip->zsize;
        } else {
                devip->zcap = (sdeb_zbc_zone_cap_mb * SZ_1M) >>
                              ilog2(sdebug_sector_size);
                if (devip->zcap > devip->zsize) {
                        pr_err("Zone capacity too large\n");
                        return -EINVAL;
                }
        }

        conv_capacity = (sector_t)sdeb_zbc_nr_conv << devip->zsize_shift;
        if (conv_capacity >= capacity) {
                pr_err("Number of conventional zones too large\n");
                return -EINVAL;
        }
        devip->nr_conv_zones = sdeb_zbc_nr_conv;
        devip->nr_seq_zones = ALIGN(capacity - conv_capacity, devip->zsize) >>
                              devip->zsize_shift;
        devip->nr_zones = devip->nr_conv_zones + devip->nr_seq_zones;

        /* Add gap zones if zone capacity is smaller than the zone size */
        if (devip->zcap < devip->zsize)
                devip->nr_zones += devip->nr_seq_zones;

        if (devip->zmodel == BLK_ZONED_HM) {
                /* zbc_max_open_zones can be 0, meaning "not reported" */
                if (sdeb_zbc_max_open >= devip->nr_zones - 1)
                        devip->max_open = (devip->nr_zones - 1) / 2;
                else
                        devip->max_open = sdeb_zbc_max_open;
        }

        devip->zstate = kcalloc(devip->nr_zones,
                                sizeof(struct sdeb_zone_state), GFP_KERNEL);
        if (!devip->zstate)
                return -ENOMEM;

        for (i = 0; i < devip->nr_zones; i++) {
                zsp = &devip->zstate[i];

                zsp->z_start = zstart;

                if (i < devip->nr_conv_zones) {
                        zsp->z_type = ZBC_ZTYPE_CNV;
                        zsp->z_cond = ZBC_NOT_WRITE_POINTER;
                        zsp->z_wp = (sector_t)-1;
                        zsp->z_size =
                                min_t(u64, devip->zsize, capacity - zstart);
                } else if ((zstart & (devip->zsize - 1)) == 0) {
                        if (devip->zmodel == BLK_ZONED_HM)
                                zsp->z_type = ZBC_ZTYPE_SWR;
                        else
                                zsp->z_type = ZBC_ZTYPE_SWP;
                        zsp->z_cond = ZC1_EMPTY;
                        zsp->z_wp = zsp->z_start;
                        zsp->z_size =
                                min_t(u64, devip->zcap, capacity - zstart);
                } else {
                        zsp->z_type = ZBC_ZTYPE_GAP;
                        zsp->z_cond = ZBC_NOT_WRITE_POINTER;
                        zsp->z_wp = (sector_t)-1;
                        zsp->z_size = min_t(u64, devip->zsize - devip->zcap,
                                            capacity - zstart);
                }

                WARN_ON_ONCE((int)zsp->z_size <= 0);
                zstart += zsp->z_size;
        }

        return 0;
}

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;
                if (sdeb_zbc_in_use) {
                        devip->zmodel = sdeb_zbc_model;
                        if (sdebug_device_create_zones(devip)) {
                                kfree(devip);
                                return NULL;
                        }
                } else {
                        devip->zmodel = BLK_ZONED_NONE;
                }
                devip->create_ts = ktime_get_boottime();
                atomic_set(&devip->stopped, (sdeb_tur_ms_to_ready > 0 ? 2 : 0));
                spin_lock_init(&devip->list_lock);
                INIT_LIST_HEAD(&devip->inject_err_list);
                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 = shost_to_sdebug_host(sdev->host);

        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;
        set_bit(SDEBUG_UA_POOCCUR, 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;
        struct dentry *dentry;

        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);

        if (sdebug_allow_restart)
                sdp->allow_restart = 1;

        devip->debugfs_entry = debugfs_create_dir(dev_name(&sdp->sdev_dev),
                                sdebug_debugfs_root);
        if (IS_ERR_OR_NULL(devip->debugfs_entry))
                pr_info("%s: failed to create debugfs directory for device %s\n",
                        __func__, dev_name(&sdp->sdev_gendev));

        dentry = debugfs_create_file("error", 0600, devip->debugfs_entry, sdp,
                                &sdebug_error_fops);
        if (IS_ERR_OR_NULL(dentry))
                pr_info("%s: failed to create error file for device %s\n",
                        __func__, dev_name(&sdp->sdev_gendev));

        return 0;
}

static void scsi_debug_slave_destroy(struct scsi_device *sdp)
{
        struct sdebug_dev_info *devip =
                (struct sdebug_dev_info *)sdp->hostdata;
        struct sdebug_err_inject *err;

        if (sdebug_verbose)
                pr_info("slave_destroy <%u %u %u %llu>\n",
                       sdp->host->host_no, sdp->channel, sdp->id, sdp->lun);

        if (!devip)
                return;

        spin_lock(&devip->list_lock);
        list_for_each_entry_rcu(err, &devip->inject_err_list, list) {
                list_del_rcu(&err->list);
                call_rcu(&err->rcu, sdebug_err_free);
        }
        spin_unlock(&devip->list_lock);

        debugfs_remove(devip->debugfs_entry);

        /* make this slot available for re-use */
        devip->used = false;
        sdp->hostdata = NULL;
}

/* Returns true if we require the queued memory to be freed by the caller. */
static bool stop_qc_helper(struct sdebug_defer *sd_dp,
                           enum sdeb_defer_type defer_t)
{
        if (defer_t == SDEB_DEFER_HRT) {
                int res = hrtimer_try_to_cancel(&sd_dp->hrt);

                switch (res) {
                case 0: /* Not active, it must have already run */
                case -1: /* -1 It's executing the CB */
                        return false;
                case 1: /* Was active, we've now cancelled */
                default:
                        return true;
                }
        } else if (defer_t == SDEB_DEFER_WQ) {
                /* Cancel if pending */
                if (cancel_work_sync(&sd_dp->ew.work))
                        return true;
                /* Was not pending, so it must have run */
                return false;
        } else if (defer_t == SDEB_DEFER_POLL) {
                return true;
        }

        return false;
}


static bool scsi_debug_stop_cmnd(struct scsi_cmnd *cmnd)
{
        enum sdeb_defer_type l_defer_t;
        struct sdebug_defer *sd_dp;
        struct sdebug_scsi_cmd *sdsc = scsi_cmd_priv(cmnd);
        struct sdebug_queued_cmd *sqcp = TO_QUEUED_CMD(cmnd);

        lockdep_assert_held(&sdsc->lock);

        if (!sqcp)
                return false;
        sd_dp = &sqcp->sd_dp;
        l_defer_t = READ_ONCE(sd_dp->defer_t);
        ASSIGN_QUEUED_CMD(cmnd, NULL);

        if (stop_qc_helper(sd_dp, l_defer_t))
                sdebug_free_queued_cmd(sqcp);

        return true;
}

/*
 * Called from scsi_debug_abort() only, which is for timed-out cmd.
 */
static bool scsi_debug_abort_cmnd(struct scsi_cmnd *cmnd)
{
        struct sdebug_scsi_cmd *sdsc = scsi_cmd_priv(cmnd);
        unsigned long flags;
        bool res;

        spin_lock_irqsave(&sdsc->lock, flags);
        res = scsi_debug_stop_cmnd(cmnd);
        spin_unlock_irqrestore(&sdsc->lock, flags);

        return res;
}

/*
 * All we can do is set the cmnd as internally aborted and wait for it to
 * finish. We cannot call scsi_done() as normal completion path may do that.
 */
static bool sdebug_stop_cmnd(struct request *rq, void *data)
{
        scsi_debug_abort_cmnd(blk_mq_rq_to_pdu(rq));

        return true;
}

/* Deletes (stops) timers or work queues of all queued commands */
static void stop_all_queued(void)
{
        struct sdebug_host_info *sdhp;

        mutex_lock(&sdebug_host_list_mutex);
        list_for_each_entry(sdhp, &sdebug_host_list, host_list) {
                struct Scsi_Host *shost = sdhp->shost;

                blk_mq_tagset_busy_iter(&shost->tag_set, sdebug_stop_cmnd, NULL);
        }
        mutex_unlock(&sdebug_host_list_mutex);
}

static int sdebug_fail_abort(struct scsi_cmnd *cmnd)
{
        struct scsi_device *sdp = cmnd->device;
        struct sdebug_dev_info *devip = (struct sdebug_dev_info *)sdp->hostdata;
        struct sdebug_err_inject *err;
        unsigned char *cmd = cmnd->cmnd;
        int ret = 0;

        if (devip == NULL)
                return 0;

        rcu_read_lock();
        list_for_each_entry_rcu(err, &devip->inject_err_list, list) {
                if (err->type == ERR_ABORT_CMD_FAILED &&
                    (err->cmd == cmd[0] || err->cmd == 0xff)) {
                        ret = !!err->cnt;
                        if (err->cnt < 0)
                                err->cnt++;

                        rcu_read_unlock();
                        return ret;
                }
        }
        rcu_read_unlock();

        return 0;
}

static int scsi_debug_abort(struct scsi_cmnd *SCpnt)
{
        bool ok = scsi_debug_abort_cmnd(SCpnt);
        u8 *cmd = SCpnt->cmnd;
        u8 opcode = cmd[0];

        ++num_aborts;

        if (SDEBUG_OPT_ALL_NOISE & sdebug_opts)
                sdev_printk(KERN_INFO, SCpnt->device,
                            "%s: command%s found\n", __func__,
                            ok ? "" : " not");

        if (sdebug_fail_abort(SCpnt)) {
                scmd_printk(KERN_INFO, SCpnt, "fail abort command 0x%x\n",
                            opcode);
                return FAILED;
        }

        return SUCCESS;
}

static bool scsi_debug_stop_all_queued_iter(struct request *rq, void *data)
{
        struct scsi_device *sdp = data;
        struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);

        if (scmd->device == sdp)
                scsi_debug_abort_cmnd(scmd);

        return true;
}

/* Deletes (stops) timers or work queues of all queued commands per sdev */
static void scsi_debug_stop_all_queued(struct scsi_device *sdp)
{
        struct Scsi_Host *shost = sdp->host;

        blk_mq_tagset_busy_iter(&shost->tag_set,
                                scsi_debug_stop_all_queued_iter, sdp);
}

static int sdebug_fail_lun_reset(struct scsi_cmnd *cmnd)
{
        struct scsi_device *sdp = cmnd->device;
        struct sdebug_dev_info *devip = (struct sdebug_dev_info *)sdp->hostdata;
        struct sdebug_err_inject *err;
        unsigned char *cmd = cmnd->cmnd;
        int ret = 0;

        if (devip == NULL)
                return 0;

        rcu_read_lock();
        list_for_each_entry_rcu(err, &devip->inject_err_list, list) {
                if (err->type == ERR_LUN_RESET_FAILED &&
                    (err->cmd == cmd[0] || err->cmd == 0xff)) {
                        ret = !!err->cnt;
                        if (err->cnt < 0)
                                err->cnt++;

                        rcu_read_unlock();
                        return ret;
                }
        }
        rcu_read_unlock();

        return 0;
}

static int scsi_debug_device_reset(struct scsi_cmnd *SCpnt)
{
        struct scsi_device *sdp = SCpnt->device;
        struct sdebug_dev_info *devip = sdp->hostdata;
        u8 *cmd = SCpnt->cmnd;
        u8 opcode = cmd[0];

        ++num_dev_resets;

        if (SDEBUG_OPT_ALL_NOISE & sdebug_opts)
                sdev_printk(KERN_INFO, sdp, "%s\n", __func__);

        scsi_debug_stop_all_queued(sdp);
        if (devip)
                set_bit(SDEBUG_UA_POR, devip->uas_bm);

        if (sdebug_fail_lun_reset(SCpnt)) {
                scmd_printk(KERN_INFO, SCpnt, "fail lun reset 0x%x\n", opcode);
                return FAILED;
        }

        return SUCCESS;
}

static int sdebug_fail_target_reset(struct scsi_cmnd *cmnd)
{
        struct scsi_target *starget = scsi_target(cmnd->device);
        struct sdebug_target_info *targetip =
                (struct sdebug_target_info *)starget->hostdata;

        if (targetip)
                return targetip->reset_fail;

        return 0;
}

static int scsi_debug_target_reset(struct scsi_cmnd *SCpnt)
{
        struct scsi_device *sdp = SCpnt->device;
        struct sdebug_host_info *sdbg_host = shost_to_sdebug_host(sdp->host);
        struct sdebug_dev_info *devip;
        u8 *cmd = SCpnt->cmnd;
        u8 opcode = cmd[0];
        int k = 0;

        ++num_target_resets;
        if (SDEBUG_OPT_ALL_NOISE & sdebug_opts)
                sdev_printk(KERN_INFO, sdp, "%s\n", __func__);

        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);

        if (sdebug_fail_target_reset(SCpnt)) {
                scmd_printk(KERN_INFO, SCpnt, "fail target reset 0x%x\n",
                            opcode);
                return FAILED;
        }

        return SUCCESS;
}

static int scsi_debug_bus_reset(struct scsi_cmnd *SCpnt)
{
        struct scsi_device *sdp = SCpnt->device;
        struct sdebug_host_info *sdbg_host = shost_to_sdebug_host(sdp->host);
        struct sdebug_dev_info *devip;
        int k = 0;

        ++num_bus_resets;

        if (SDEBUG_OPT_ALL_NOISE & sdebug_opts)
                sdev_printk(KERN_INFO, sdp, "%s\n", __func__);

        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);
        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 (SDEBUG_OPT_ALL_NOISE & sdebug_opts)
                sdev_printk(KERN_INFO, SCpnt->device, "%s\n", __func__);
        mutex_lock(&sdebug_host_list_mutex);
        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;
                }
        }
        mutex_unlock(&sdebug_host_list_mutex);
        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 sdebug_build_parts(unsigned char *ramp, unsigned long store_size)
{
        struct msdos_partition *pp;
        int starts[SDEBUG_MAX_PARTS + 2], max_part_secs;
        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)get_sdebug_capacity();
        sectors_per_part = (num_sectors - sdebug_sectors_per)
                           / sdebug_num_parts;
        heads_by_sects = sdebug_heads * sdebug_sectors_per;
        starts[0] = sdebug_sectors_per;
        max_part_secs = sectors_per_part;
        for (k = 1; k < sdebug_num_parts; ++k) {
                starts[k] = ((k * sectors_per_part) / heads_by_sects)
                            * heads_by_sects;
                if (starts[k] - starts[k - 1] < max_part_secs)
                        max_part_secs = starts[k] - starts[k - 1];
        }
        starts[sdebug_num_parts] = num_sectors;
        starts[sdebug_num_parts + 1] = 0;

        ramp[510] = 0x55;       /* magic partition markings */
        ramp[511] = 0xAA;
        pp = (struct msdos_partition *)(ramp + 0x1be);
        for (k = 0; starts[k + 1]; ++k, ++pp) {
                start_sec = starts[k];
                end_sec = starts[k] + max_part_secs - 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)
{
        struct sdebug_host_info *sdhp;

        lockdep_assert_held(&sdebug_host_list_mutex);

        list_for_each_entry(sdhp, &sdebug_host_list, host_list) {
                struct Scsi_Host *shost = sdhp->shost;

                if (block)
                        scsi_block_requests(shost);
                else
                        scsi_unblock_requests(shost);
        }
}

/* 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;

        mutex_lock(&sdebug_host_list_mutex);
        block_unblock_all_queues(true);
        count = atomic_read(&sdebug_cmnd_count);
        atomic_set(&sdebug_cmnd_count, (count / modulo) * modulo);
        block_unblock_all_queues(false);
        mutex_unlock(&sdebug_host_list_mutex);
}

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 bool inject_on_this_cmd(void)
{
        if (sdebug_every_nth == 0)
                return false;
        return (atomic_read(&sdebug_cmnd_count) % abs(sdebug_every_nth)) == 0;
}

#define INCLUSIVE_TIMING_MAX_NS 1000000         /* 1 millisecond */


void sdebug_free_queued_cmd(struct sdebug_queued_cmd *sqcp)
{
        if (sqcp)
                kmem_cache_free(queued_cmd_cache, sqcp);
}

static struct sdebug_queued_cmd *sdebug_alloc_queued_cmd(struct scsi_cmnd *scmd)
{
        struct sdebug_queued_cmd *sqcp;
        struct sdebug_defer *sd_dp;

        sqcp = kmem_cache_zalloc(queued_cmd_cache, GFP_ATOMIC);
        if (!sqcp)
                return NULL;

        sd_dp = &sqcp->sd_dp;

        hrtimer_init(&sd_dp->hrt, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
        sd_dp->hrt.function = sdebug_q_cmd_hrt_complete;
        INIT_WORK(&sd_dp->ew.work, sdebug_q_cmd_wq_complete);

        sqcp->scmd = scmd;

        return sqcp;
}

/* 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)
{
        struct request *rq = scsi_cmd_to_rq(cmnd);
        bool polled = rq->cmd_flags & REQ_POLLED;
        struct sdebug_scsi_cmd *sdsc = scsi_cmd_priv(cmnd);
        unsigned long flags;
        u64 ns_from_boot = 0;
        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;


        if (unlikely(sdebug_every_nth && (SDEBUG_OPT_RARE_TSF & sdebug_opts) &&
                     (scsi_result == 0))) {
                int num_in_q = scsi_device_busy(sdp);
                int qdepth = cmnd->device->queue_depth;

                if ((num_in_q == qdepth) &&
                    (atomic_inc_return(&sdebug_a_tsf) >=
                     abs(sdebug_every_nth))) {
                        atomic_set(&sdebug_a_tsf, 0);
                        scsi_result = device_qfull_result;

                        if (unlikely(SDEBUG_OPT_Q_NOISE & sdebug_opts))
                                sdev_printk(KERN_INFO, sdp, "%s: num_in_q=%d +1, <inject> status: TASK SET FULL\n",
                                            __func__, num_in_q);
                }
        }

        sqcp = sdebug_alloc_queued_cmd(cmnd);
        if (!sqcp) {
                pr_err("%s no alloc\n", __func__);
                return SCSI_MLQUEUE_HOST_BUSY;
        }
        sd_dp = &sqcp->sd_dp;

        if (polled)
                ns_from_boot = ktime_get_boottime_ns();

        /* one of the resp_*() response functions is called here */
        cmnd->result = pfp ? pfp(cmnd, devip) : 0;
        if (cmnd->result & SDEG_RES_IMMED_MASK) {
                cmnd->result &= ~SDEG_RES_IMMED_MASK;
                delta_jiff = ndelay = 0;
        }
        if (cmnd->result == 0 && scsi_result != 0)
                cmnd->result = scsi_result;
        if (cmnd->result == 0 && unlikely(sdebug_opts & SDEBUG_OPT_TRANSPORT_ERR)) {
                if (atomic_read(&sdeb_inject_pending)) {
                        mk_sense_buffer(cmnd, ABORTED_COMMAND, TRANSPORT_PROBLEM, ACK_NAK_TO);
                        atomic_set(&sdeb_inject_pending, 0);
                        cmnd->result = check_condition_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) {
                        u64 ns = jiffies_to_nsecs(delta_jiff);

                        if (sdebug_random && ns < U32_MAX) {
                                ns = get_random_u32_below((u32)ns);
                        } else if (sdebug_random) {
                                ns >>= 12;      /* scale to 4 usec precision */
                                if (ns < U32_MAX)       /* over 4 hours max */
                                        ns = get_random_u32_below((u32)ns);
                                ns <<= 12;
                        }
                        kt = ns_to_ktime(ns);
                } else {        /* ndelay has a 4.2 second max */
                        kt = sdebug_random ? get_random_u32_below((u32)ndelay) :
                                             (u32)ndelay;
                        if (ndelay < INCLUSIVE_TIMING_MAX_NS) {
                                u64 d = ktime_get_boottime_ns() - ns_from_boot;

                                if (kt <= d) {  /* elapsed duration >= kt */
                                        /* call scsi_done() from this thread */
                                        sdebug_free_queued_cmd(sqcp);
                                        scsi_done(cmnd);
                                        return 0;
                                }
                                /* otherwise reduce kt by elapsed time */
                                kt -= d;
                        }
                }
                if (sdebug_statistics)
                        sd_dp->issuing_cpu = raw_smp_processor_id();
                if (polled) {
                        spin_lock_irqsave(&sdsc->lock, flags);
                        sd_dp->cmpl_ts = ktime_add(ns_to_ktime(ns_from_boot), kt);
                        ASSIGN_QUEUED_CMD(cmnd, sqcp);
                        WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_POLL);
                        spin_unlock_irqrestore(&sdsc->lock, flags);
                } else {
                        /* schedule the invocation of scsi_done() for a later time */
                        spin_lock_irqsave(&sdsc->lock, flags);
                        ASSIGN_QUEUED_CMD(cmnd, sqcp);
                        WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_HRT);
                        hrtimer_start(&sd_dp->hrt, kt, HRTIMER_MODE_REL_PINNED);
                        /*
                         * The completion handler will try to grab sqcp->lock,
                         * so there is no chance that the completion handler
                         * will call scsi_done() until we release the lock
                         * here (so ok to keep referencing sdsc).
                         */
                        spin_unlock_irqrestore(&sdsc->lock, flags);
                }
        } else {        /* jdelay < 0, use work queue */
                if (unlikely((sdebug_opts & SDEBUG_OPT_CMD_ABORT) &&
                             atomic_read(&sdeb_inject_pending))) {
                        sd_dp->aborted = true;
                        atomic_set(&sdeb_inject_pending, 0);
                        sdev_printk(KERN_INFO, sdp, "abort request tag=%#x\n",
                                    blk_mq_unique_tag_to_tag(get_tag(cmnd)));
                }

                if (sdebug_statistics)
                        sd_dp->issuing_cpu = raw_smp_processor_id();
                if (polled) {
                        spin_lock_irqsave(&sdsc->lock, flags);
                        ASSIGN_QUEUED_CMD(cmnd, sqcp);
                        sd_dp->cmpl_ts = ns_to_ktime(ns_from_boot);
                        WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_POLL);
                        spin_unlock_irqrestore(&sdsc->lock, flags);
                } else {
                        spin_lock_irqsave(&sdsc->lock, flags);
                        ASSIGN_QUEUED_CMD(cmnd, sqcp);
                        WRITE_ONCE(sd_dp->defer_t, SDEB_DEFER_WQ);
                        schedule_work(&sd_dp->ew.work);
                        spin_unlock_irqrestore(&sdsc->lock, flags);
                }
        }

        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;
        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_named(host_max_queue, sdebug_host_max_queue, int, S_IRUGO);
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_string(inq_vendor, sdebug_inq_vendor_id,
                    sizeof(sdebug_inq_vendor_id), S_IRUGO | S_IWUSR);
module_param_named(lbprz, sdebug_lbprz, int, S_IRUGO);
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(lowest_aligned, sdebug_lowest_aligned, int, S_IRUGO);
module_param_named(lun_format, sdebug_lun_am_i, int, S_IRUGO | S_IWUSR);
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_count, sdebug_medium_error_count, int,
                   S_IRUGO | S_IWUSR);
module_param_named(medium_error_start, sdebug_medium_error_start, 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_rwlock, sdebug_no_rwlock, bool, 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(opt_xferlen_exp, sdebug_opt_xferlen_exp, int, S_IRUGO);
module_param_named(opts, sdebug_opts, int, S_IRUGO | S_IWUSR);
module_param_named(per_host_store, sdebug_per_host_store, bool,
                   S_IRUGO | S_IWUSR);
module_param_named(physblk_exp, sdebug_physblk_exp, int, S_IRUGO);
module_param_named(ptype, sdebug_ptype, int, S_IRUGO | S_IWUSR);
module_param_named(random, sdebug_random, bool, 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(poll_queues, poll_queues, int, S_IRUGO);
module_param_named(tur_ms_to_ready, sdeb_tur_ms_to_ready, 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(uuid_ctl, sdebug_uuid_ctl, int, S_IRUGO);
module_param_named(virtual_gb, sdebug_virtual_gb, int, S_IRUGO | S_IWUSR);
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_param_named(zbc, sdeb_zbc_model_s, charp, S_IRUGO);
module_param_named(zone_cap_mb, sdeb_zbc_zone_cap_mb, int, S_IRUGO);
module_param_named(zone_max_open, sdeb_zbc_max_open, int, S_IRUGO);
module_param_named(zone_nr_conv, sdeb_zbc_nr_conv, int, S_IRUGO);
module_param_named(zone_size_mb, sdeb_zbc_zone_size_mb, int, S_IRUGO);
module_param_named(allow_restart, sdebug_allow_restart, bool, 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, "add n hosts, in sysfs if negative remove host(s) (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(host_max_queue,
                 "host max # of queued cmds (0 to max(def) [max_queue fixed equal for !0])");
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(inq_vendor, "SCSI INQUIRY vendor string (def=\"Linux\")");
MODULE_PARM_DESC(lbprz,
                 "on read unmapped LBs return 0 when 1 (def), return 0xff when 2");
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(lowest_aligned, "lowest aligned lba (def=0)");
MODULE_PARM_DESC(lun_format, "LUN format: 0->peripheral (def); 1 --> flat address method");
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_count, "count of sectors to return follow on MEDIUM error");
MODULE_PARM_DESC(medium_error_start, "starting sector number to return 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_rwlock, "don't protect user data reads+writes (def=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(opt_xferlen_exp, "optimal transfer length granularity exponent (def=physblk_exp)");
MODULE_PARM_DESC(opts, "1->noise, 2->medium_err, 4->timeout, 8->recovered_err... (def=0)");
MODULE_PARM_DESC(per_host_store, "If set, next positive add_host will get new store (def=0)");
MODULE_PARM_DESC(physblk_exp, "physical block exponent (def=0)");
MODULE_PARM_DESC(poll_queues, "support for iouring iopoll queues (1 to max(submit_queues - 1))");
MODULE_PARM_DESC(ptype, "SCSI peripheral type(def=0[disk])");
MODULE_PARM_DESC(random, "If set, uniformly randomize command duration between 0 and delay_in_ns");
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(tur_ms_to_ready, "TEST UNIT READY millisecs before initial good status (def=0)");
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)");
MODULE_PARM_DESC(zbc, "'none' [0]; 'aware' [1]; 'managed' [2] (def=0). Can have 'host-' prefix");
MODULE_PARM_DESC(zone_cap_mb, "Zone capacity in MiB (def=zone size)");
MODULE_PARM_DESC(zone_max_open, "Maximum number of open zones; [0] for no limit (def=auto)");
MODULE_PARM_DESC(zone_nr_conv, "Number of conventional zones (def=1)");
MODULE_PARM_DESC(zone_size_mb, "Zone size in MiB (def=auto)");
MODULE_PARM_DESC(allow_restart, "Set scsi_device's allow_restart flag(def=0)");

#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;
}

struct sdebug_submit_queue_data {
        int *first;
        int *last;
        int queue_num;
};

static bool sdebug_submit_queue_iter(struct request *rq, void *opaque)
{
        struct sdebug_submit_queue_data *data = opaque;
        u32 unique_tag = blk_mq_unique_tag(rq);
        u16 hwq = blk_mq_unique_tag_to_hwq(unique_tag);
        u16 tag = blk_mq_unique_tag_to_tag(unique_tag);
        int queue_num = data->queue_num;

        if (hwq != queue_num)
                return true;

        /* Rely on iter'ing in ascending tag order */
        if (*data->first == -1)
                *data->first = *data->last = tag;
        else
                *data->last = tag;

        return true;
}

/* 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)
{
        struct sdebug_host_info *sdhp;
        int j;

        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, mq_polls=%d\n",
                   atomic_read(&sdebug_cmnd_count),
                   atomic_read(&sdebug_completions),
                   "miss_cpus", atomic_read(&sdebug_miss_cpus),
                   atomic_read(&sdebug_a_tsf),
                   atomic_read(&sdeb_mq_poll_count));

        seq_printf(m, "submit_queues=%d\n", submit_queues);
        for (j = 0; j < submit_queues; ++j) {
                int f = -1, l = -1;
                struct sdebug_submit_queue_data data = {
                        .queue_num = j,
                        .first = &f,
                        .last = &l,
                };
                seq_printf(m, "  queue %d:\n", j);
                blk_mq_tagset_busy_iter(&host->tag_set, sdebug_submit_queue_iter,
                                        &data);
                if (f >= 0) {
                        seq_printf(m, "    in_use_bm BUSY: %s: %d,%d\n",
                                   "first,last bits", f, l);
                }
        }

        seq_printf(m, "this host_no=%d\n", host->host_no);
        if (!xa_empty(per_store_ap)) {
                bool niu;
                int idx;
                unsigned long l_idx;
                struct sdeb_store_info *sip;

                seq_puts(m, "\nhost list:\n");
                j = 0;
                list_for_each_entry(sdhp, &sdebug_host_list, host_list) {
                        idx = sdhp->si_idx;
                        seq_printf(m, "  %d: host_no=%d, si_idx=%d\n", j,
                                   sdhp->shost->host_no, idx);
                        ++j;
                }
                seq_printf(m, "\nper_store array [most_recent_idx=%d]:\n",
                           sdeb_most_recent_idx);
                j = 0;
                xa_for_each(per_store_ap, l_idx, sip) {
                        niu = xa_get_mark(per_store_ap, l_idx,
                                          SDEB_XA_NOT_IN_USE);
                        idx = (int)l_idx;
                        seq_printf(m, "  %d: idx=%d%s\n", j, idx,
                                   (niu ? "  not_in_use" : ""));
                        ++j;
                }
        }
        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) {
                        struct sdebug_host_info *sdhp;

                        mutex_lock(&sdebug_host_list_mutex);
                        block_unblock_all_queues(true);

                        list_for_each_entry(sdhp, &sdebug_host_list, host_list) {
                                struct Scsi_Host *shost = sdhp->shost;

                                if (scsi_host_busy(shost)) {
                                        res = -EBUSY;   /* queued commands */
                                        break;
                                }
                        }
                        if (res > 0) {
                                sdebug_jdelay = jdelay;
                                sdebug_ndelay = 0;
                        }
                        block_unblock_all_queues(false);
                        mutex_unlock(&sdebug_host_list_mutex);
                }
                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) {
                        struct sdebug_host_info *sdhp;

                        mutex_lock(&sdebug_host_list_mutex);
                        block_unblock_all_queues(true);

                        list_for_each_entry(sdhp, &sdebug_host_list, host_list) {
                                struct Scsi_Host *shost = sdhp->shost;

                                if (scsi_host_busy(shost)) {
                                        res = -EBUSY;   /* queued commands */
                                        break;
                                }
                        }

                        if (res > 0) {
                                sdebug_ndelay = ndelay;
                                sdebug_jdelay = ndelay  ? JDELAY_OVERRIDDEN
                                                        : DEF_JDELAY;
                        }
                        block_unblock_all_queues(false);
                        mutex_unlock(&sdebug_host_list_mutex);
                }
                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;

        /* Cannot change from or to TYPE_ZBC with sysfs */
        if (sdebug_ptype == TYPE_ZBC)
                return -EINVAL;

        if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
                if (n == TYPE_ZBC)
                        return -EINVAL;
                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, idx;

        if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
                bool want_store = (n == 0);
                struct sdebug_host_info *sdhp;

                n = (n > 0);
                sdebug_fake_rw = (sdebug_fake_rw > 0);
                if (sdebug_fake_rw == n)
                        return count;   /* not transitioning so do nothing */

                if (want_store) {       /* 1 --> 0 transition, set up store */
                        if (sdeb_first_idx < 0) {
                                idx = sdebug_add_store();
                                if (idx < 0)
                                        return idx;
                        } else {
                                idx = sdeb_first_idx;
                                xa_clear_mark(per_store_ap, idx,
                                              SDEB_XA_NOT_IN_USE);
                        }
                        /* make all hosts use same store */
                        list_for_each_entry(sdhp, &sdebug_host_list,
                                            host_list) {
                                if (sdhp->si_idx != idx) {
                                        xa_set_mark(per_store_ap, sdhp->si_idx,
                                                    SDEB_XA_NOT_IN_USE);
                                        sdhp->si_idx = idx;
                                }
                        }
                        sdeb_most_recent_idx = idx;
                } else {        /* 0 --> 1 transition is trigger for shrink */
                        sdebug_erase_all_stores(true /* apart from first */);
                }
                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 per_host_store_show(struct device_driver *ddp, char *buf)
{
        return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_per_host_store);
}

static ssize_t per_host_store_store(struct device_driver *ddp, const char *buf,
                                    size_t count)
{
        bool v;

        if (kstrtobool(buf, &v))
                return -EINVAL;

        sdebug_per_host_store = v;
        return count;
}
static DRIVER_ATTR_RW(per_host_store);

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;
        char work[20];

        if (sscanf(buf, "%10s", work) == 1) {
                if (strncasecmp(work, "0x", 2) == 0) {
                        if (kstrtoint(work + 2, 16, &nth) == 0)
                                goto every_nth_done;
                } else {
                        if (kstrtoint(work, 10, &nth) == 0)
                                goto every_nth_done;
                }
        }
        return -EINVAL;

every_nth_done:
        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;
}
static DRIVER_ATTR_RW(every_nth);

static ssize_t lun_format_show(struct device_driver *ddp, char *buf)
{
        return scnprintf(buf, PAGE_SIZE, "%d\n", (int)sdebug_lun_am);
}
static ssize_t lun_format_store(struct device_driver *ddp, const char *buf,
                                size_t count)
{
        int n;
        bool changed;

        if (kstrtoint(buf, 0, &n))
                return -EINVAL;
        if (n >= 0) {
                if (n > (int)SAM_LUN_AM_FLAT) {
                        pr_warn("only LUN address methods 0 and 1 are supported\n");
                        return -EINVAL;
                }
                changed = ((int)sdebug_lun_am != n);
                sdebug_lun_am = n;
                if (changed && sdebug_scsi_level >= 5) {        /* >= SPC-3 */
                        struct sdebug_host_info *sdhp;
                        struct sdebug_dev_info *dp;

                        mutex_lock(&sdebug_host_list_mutex);
                        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);
                                }
                        }
                        mutex_unlock(&sdebug_host_list_mutex);
                }
                return count;
        }
        return -EINVAL;
}
static DRIVER_ATTR_RW(lun_format);

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;

                        mutex_lock(&sdebug_host_list_mutex);
                        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);
                                }
                        }
                        mutex_unlock(&sdebug_host_list_mutex);
                }
                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 n;

        if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n > 0) &&
            (n <= SDEBUG_CANQUEUE) &&
            (sdebug_host_max_queue == 0)) {
                mutex_lock(&sdebug_host_list_mutex);

                /* We may only change sdebug_max_queue when we have no shosts */
                if (list_empty(&sdebug_host_list))
                        sdebug_max_queue = n;
                else
                        count = -EBUSY;
                mutex_unlock(&sdebug_host_list_mutex);
                return count;
        }
        return -EINVAL;
}
static DRIVER_ATTR_RW(max_queue);

static ssize_t host_max_queue_show(struct device_driver *ddp, char *buf)
{
        return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_host_max_queue);
}

static ssize_t no_rwlock_show(struct device_driver *ddp, char *buf)
{
        return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_no_rwlock);
}

static ssize_t no_rwlock_store(struct device_driver *ddp, const char *buf, size_t count)
{
        bool v;

        if (kstrtobool(buf, &v))
                return -EINVAL;

        sdebug_no_rwlock = v;
        return count;
}
static DRIVER_ATTR_RW(no_rwlock);

/*
 * Since this is used for .can_queue, and we get the hc_idx tag from the bitmap
 * in range [0, sdebug_host_max_queue), we can't change it.
 */
static DRIVER_ATTR_RO(host_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;

        /* Ignore capacity change for ZBC drives for now */
        if (sdeb_zbc_in_use)
                return -ENOTSUPP;

        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;

                        mutex_lock(&sdebug_host_list_mutex);
                        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);
                                }
                        }
                        mutex_unlock(&sdebug_host_list_mutex);
                }
                return count;
        }
        return -EINVAL;
}
static DRIVER_ATTR_RW(virtual_gb);

static ssize_t add_host_show(struct device_driver *ddp, char *buf)
{
        /* absolute number of hosts currently active is what is shown */
        return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_num_hosts);
}

static ssize_t add_host_store(struct device_driver *ddp, const char *buf,
                              size_t count)
{
        bool found;
        unsigned long idx;
        struct sdeb_store_info *sip;
        bool want_phs = (sdebug_fake_rw == 0) && sdebug_per_host_store;
        int delta_hosts;

        if (sscanf(buf, "%d", &delta_hosts) != 1)
                return -EINVAL;
        if (delta_hosts > 0) {
                do {
                        found = false;
                        if (want_phs) {
                                xa_for_each_marked(per_store_ap, idx, sip,
                                                   SDEB_XA_NOT_IN_USE) {
                                        sdeb_most_recent_idx = (int)idx;
                                        found = true;
                                        break;
                                }
                                if (found)      /* re-use case */
                                        sdebug_add_host_helper((int)idx);
                                else
                                        sdebug_do_add_host(true);
                        } else {
                                sdebug_do_add_host(false);
                        }
                } while (--delta_hosts);
        } else if (delta_hosts < 0) {
                do {
                        sdebug_do_remove_host(false);
                } 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 = 0;

        if (!scsi_debug_lbp())
                return scnprintf(buf, PAGE_SIZE, "0-%u\n",
                                 sdebug_store_sectors);

        if (sdebug_fake_rw == 0 && !xa_empty(per_store_ap)) {
                struct sdeb_store_info *sip = xa_load(per_store_ap, 0);

                if (sip)
                        count = scnprintf(buf, PAGE_SIZE - 1, "%*pbl",
                                          (int)map_size, sip->map_storep);
        }
        buf[count++] = '\n';
        buf[count] = '\0';

        return count;
}
static DRIVER_ATTR_RO(map);

static ssize_t random_show(struct device_driver *ddp, char *buf)
{
        return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_random);
}

static ssize_t random_store(struct device_driver *ddp, const char *buf,
                            size_t count)
{
        bool v;

        if (kstrtobool(buf, &v))
                return -EINVAL;

        sdebug_random = v;
        return count;
}
static DRIVER_ATTR_RW(random);

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);

static const char * const zbc_model_strs_a[] = {
        [BLK_ZONED_NONE] = "none",
        [BLK_ZONED_HA]   = "host-aware",
        [BLK_ZONED_HM]   = "host-managed",
};

static const char * const zbc_model_strs_b[] = {
        [BLK_ZONED_NONE] = "no",
        [BLK_ZONED_HA]   = "aware",
        [BLK_ZONED_HM]   = "managed",
};

static const char * const zbc_model_strs_c[] = {
        [BLK_ZONED_NONE] = "0",
        [BLK_ZONED_HA]   = "1",
        [BLK_ZONED_HM]   = "2",
};

static int sdeb_zbc_model_str(const char *cp)
{
        int res = sysfs_match_string(zbc_model_strs_a, cp);

        if (res < 0) {
                res = sysfs_match_string(zbc_model_strs_b, cp);
                if (res < 0) {
                        res = sysfs_match_string(zbc_model_strs_c, cp);
                        if (res < 0)
                                return -EINVAL;
                }
        }
        return res;
}

static ssize_t zbc_show(struct device_driver *ddp, char *buf)
{
        return scnprintf(buf, PAGE_SIZE, "%s\n",
                         zbc_model_strs_a[sdeb_zbc_model]);
}
static DRIVER_ATTR_RO(zbc);

static ssize_t tur_ms_to_ready_show(struct device_driver *ddp, char *buf)
{
        return scnprintf(buf, PAGE_SIZE, "%d\n", sdeb_tur_ms_to_ready);
}
static DRIVER_ATTR_RO(tur_ms_to_ready);

/* 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: 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_host_max_queue.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_lun_format.attr,
        &driver_attr_max_luns.attr,
        &driver_attr_max_queue.attr,
        &driver_attr_no_rwlock.attr,
        &driver_attr_no_uld.attr,
        &driver_attr_scsi_level.attr,
        &driver_attr_virtual_gb.attr,
        &driver_attr_add_host.attr,
        &driver_attr_per_host_store.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_random.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,
        &driver_attr_tur_ms_to_ready.attr,
        &driver_attr_zbc.attr,
        NULL,
};
ATTRIBUTE_GROUPS(sdebug_drv);

static struct device *pseudo_primary;

static int __init scsi_debug_init(void)
{
        bool want_store = (sdebug_fake_rw == 0);
        unsigned long sz;
        int k, ret, hosts_to_add;
        int idx = -1;

        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;
        }

        sdebug_lun_am = sdebug_lun_am_i;
        if (sdebug_lun_am > SAM_LUN_AM_FLAT) {
                pr_warn("Invalid LUN format %u, using default\n", (int)sdebug_lun_am);
                sdebug_lun_am = SAM_LUN_AM_PERIPHERAL;
        }

        if (sdebug_max_luns > 256) {
                if (sdebug_max_luns > 16384) {
                        pr_warn("max_luns can be no more than 16384, use default\n");
                        sdebug_max_luns = DEF_MAX_LUNS;
                }
                sdebug_lun_am = SAM_LUN_AM_FLAT;
        }

        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;
        }

        if ((sdebug_max_queue > SDEBUG_CANQUEUE) || (sdebug_max_queue < 1)) {
                pr_err("max_queue must be in range [1, %d]\n", SDEBUG_CANQUEUE);
                return -EINVAL;
        }

        if ((sdebug_host_max_queue > SDEBUG_CANQUEUE) ||
            (sdebug_host_max_queue < 0)) {
                pr_err("host_max_queue must be in range [0 %d]\n",
                       SDEBUG_CANQUEUE);
                return -EINVAL;
        }

        if (sdebug_host_max_queue &&
            (sdebug_max_queue != sdebug_host_max_queue)) {
                sdebug_max_queue = sdebug_host_max_queue;
                pr_warn("fixing max submit queue depth to host max queue depth, %d\n",
                        sdebug_max_queue);
        }

        /*
         * check for host managed zoned block device specified with
         * ptype=0x14 or zbc=XXX.
         */
        if (sdebug_ptype == TYPE_ZBC) {
                sdeb_zbc_model = BLK_ZONED_HM;
        } else if (sdeb_zbc_model_s && *sdeb_zbc_model_s) {
                k = sdeb_zbc_model_str(sdeb_zbc_model_s);
                if (k < 0)
                        return k;
                sdeb_zbc_model = k;
                switch (sdeb_zbc_model) {
                case BLK_ZONED_NONE:
                case BLK_ZONED_HA:
                        sdebug_ptype = TYPE_DISK;
                        break;
                case BLK_ZONED_HM:
                        sdebug_ptype = TYPE_ZBC;
                        break;
                default:
                        pr_err("Invalid ZBC model\n");
                        return -EINVAL;
                }
        }
        if (sdeb_zbc_model != BLK_ZONED_NONE) {
                sdeb_zbc_in_use = true;
                if (sdebug_dev_size_mb == DEF_DEV_SIZE_PRE_INIT)
                        sdebug_dev_size_mb = DEF_ZBC_DEV_SIZE_MB;
        }

        if (sdebug_dev_size_mb == DEF_DEV_SIZE_PRE_INIT)
                sdebug_dev_size_mb = DEF_DEV_SIZE_MB;
        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 (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");
                        return -EINVAL;
                }
        }
        xa_init_flags(per_store_ap, XA_FLAGS_ALLOC | XA_FLAGS_LOCK_IRQ);
        if (want_store) {
                idx = sdebug_add_store();
                if (idx < 0)
                        return idx;
        }

        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;
        }

        hosts_to_add = sdebug_add_host;
        sdebug_add_host = 0;

        queued_cmd_cache = KMEM_CACHE(sdebug_queued_cmd, SLAB_HWCACHE_ALIGN);
        if (!queued_cmd_cache) {
                ret = -ENOMEM;
                goto driver_unreg;
        }

        sdebug_debugfs_root = debugfs_create_dir("scsi_debug", NULL);
        if (IS_ERR_OR_NULL(sdebug_debugfs_root))
                pr_info("%s: failed to create initial debugfs directory\n", __func__);

        for (k = 0; k < hosts_to_add; k++) {
                if (want_store && k == 0) {
                        ret = sdebug_add_host_helper(idx);
                        if (ret < 0) {
                                pr_err("add_host_helper k=%d, error=%d\n",
                                       k, -ret);
                                break;
                        }
                } else {
                        ret = sdebug_do_add_host(want_store &&
                                                 sdebug_per_host_store);
                        if (ret < 0) {
                                pr_err("add_host k=%d error=%d\n", k, -ret);
                                break;
                        }
                }
        }
        if (sdebug_verbose)
                pr_info("built %d host(s)\n", sdebug_num_hosts);

        return 0;

driver_unreg:
        driver_unregister(&sdebug_driverfs_driver);
bus_unreg:
        bus_unregister(&pseudo_lld_bus);
dev_unreg:
        root_device_unregister(pseudo_primary);
free_vm:
        sdebug_erase_store(idx, NULL);
        return ret;
}

static void __exit scsi_debug_exit(void)
{
        int k = sdebug_num_hosts;

        for (; k; k--)
                sdebug_do_remove_host(true);
        kmem_cache_destroy(queued_cmd_cache);
        driver_unregister(&sdebug_driverfs_driver);
        bus_unregister(&pseudo_lld_bus);
        root_device_unregister(pseudo_primary);

        sdebug_erase_all_stores(false);
        xa_destroy(per_store_ap);
        debugfs_remove(sdebug_debugfs_root);
}

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 = dev_to_sdebug_host(dev);
        kfree(sdbg_host);
}

/* idx must be valid, if sip is NULL then it will be obtained using idx */
static void sdebug_erase_store(int idx, struct sdeb_store_info *sip)
{
        if (idx < 0)
                return;
        if (!sip) {
                if (xa_empty(per_store_ap))
                        return;
                sip = xa_load(per_store_ap, idx);
                if (!sip)
                        return;
        }
        vfree(sip->map_storep);
        vfree(sip->dif_storep);
        vfree(sip->storep);
        xa_erase(per_store_ap, idx);
        kfree(sip);
}

/* Assume apart_from_first==false only in shutdown case. */
static void sdebug_erase_all_stores(bool apart_from_first)
{
        unsigned long idx;
        struct sdeb_store_info *sip = NULL;

        xa_for_each(per_store_ap, idx, sip) {
                if (apart_from_first)
                        apart_from_first = false;
                else
                        sdebug_erase_store(idx, sip);
        }
        if (apart_from_first)
                sdeb_most_recent_idx = sdeb_first_idx;
}

/*
 * Returns store xarray new element index (idx) if >=0 else negated errno.
 * Limit the number of stores to 65536.
 */
static int sdebug_add_store(void)
{
        int res;
        u32 n_idx;
        unsigned long iflags;
        unsigned long sz = (unsigned long)sdebug_dev_size_mb * 1048576;
        struct sdeb_store_info *sip = NULL;
        struct xa_limit xal = { .max = 1 << 16, .min = 0 };

        sip = kzalloc(sizeof(*sip), GFP_KERNEL);
        if (!sip)
                return -ENOMEM;

        xa_lock_irqsave(per_store_ap, iflags);
        res = __xa_alloc(per_store_ap, &n_idx, sip, xal, GFP_ATOMIC);
        if (unlikely(res < 0)) {
                xa_unlock_irqrestore(per_store_ap, iflags);
                kfree(sip);
                pr_warn("%s: xa_alloc() errno=%d\n", __func__, -res);
                return res;
        }
        sdeb_most_recent_idx = n_idx;
        if (sdeb_first_idx < 0)
                sdeb_first_idx = n_idx;
        xa_unlock_irqrestore(per_store_ap, iflags);

        res = -ENOMEM;
        sip->storep = vzalloc(sz);
        if (!sip->storep) {
                pr_err("user data oom\n");
                goto err;
        }
        if (sdebug_num_parts > 0)
                sdebug_build_parts(sip->storep, sz);

        /* DIF/DIX: what T10 calls Protection Information (PI) */
        if (sdebug_dix) {
                int dif_size;

                dif_size = sdebug_store_sectors * sizeof(struct t10_pi_tuple);
                sip->dif_storep = vmalloc(dif_size);

                pr_info("dif_storep %u bytes @ %pK\n", dif_size,
                        sip->dif_storep);

                if (!sip->dif_storep) {
                        pr_err("DIX oom\n");
                        goto err;
                }
                memset(sip->dif_storep, 0xff, dif_size);
        }
        /* Logical Block Provisioning */
        if (scsi_debug_lbp()) {
                map_size = lba_to_map_index(sdebug_store_sectors - 1) + 1;
                sip->map_storep = vmalloc(array_size(sizeof(long),
                                                     BITS_TO_LONGS(map_size)));

                pr_info("%lu provisioning blocks\n", map_size);

                if (!sip->map_storep) {
                        pr_err("LBP map oom\n");
                        goto err;
                }

                bitmap_zero(sip->map_storep, map_size);

                /* Map first 1KB for partition table */
                if (sdebug_num_parts)
                        map_region(sip, 0, 2);
        }

        rwlock_init(&sip->macc_lck);
        return (int)n_idx;
err:
        sdebug_erase_store((int)n_idx, sip);
        pr_warn("%s: failed, errno=%d\n", __func__, -res);
        return res;
}

static int sdebug_add_host_helper(int per_host_idx)
{
        int k, devs_per_host, idx;
        int error = -ENOMEM;
        struct sdebug_host_info *sdbg_host;
        struct sdebug_dev_info *sdbg_devinfo, *tmp;

        sdbg_host = kzalloc(sizeof(*sdbg_host), GFP_KERNEL);
        if (!sdbg_host)
                return -ENOMEM;
        idx = (per_host_idx < 0) ? sdeb_first_idx : per_host_idx;
        if (xa_get_mark(per_store_ap, idx, SDEB_XA_NOT_IN_USE))
                xa_clear_mark(per_store_ap, idx, SDEB_XA_NOT_IN_USE);
        sdbg_host->si_idx = idx;

        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)
                        goto clean;
        }

        mutex_lock(&sdebug_host_list_mutex);
        list_add_tail(&sdbg_host->host_list, &sdebug_host_list);
        mutex_unlock(&sdebug_host_list_mutex);

        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_num_hosts);

        error = device_register(&sdbg_host->dev);
        if (error) {
                mutex_lock(&sdebug_host_list_mutex);
                list_del(&sdbg_host->host_list);
                mutex_unlock(&sdebug_host_list_mutex);
                goto clean;
        }

        ++sdebug_num_hosts;
        return 0;

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->zstate);
                kfree(sdbg_devinfo);
        }
        if (sdbg_host->dev.release)
                put_device(&sdbg_host->dev);
        else
                kfree(sdbg_host);
        pr_warn("%s: failed, errno=%d\n", __func__, -error);
        return error;
}

static int sdebug_do_add_host(bool mk_new_store)
{
        int ph_idx = sdeb_most_recent_idx;

        if (mk_new_store) {
                ph_idx = sdebug_add_store();
                if (ph_idx < 0)
                        return ph_idx;
        }
        return sdebug_add_host_helper(ph_idx);
}

static void sdebug_do_remove_host(bool the_end)
{
        int idx = -1;
        struct sdebug_host_info *sdbg_host = NULL;
        struct sdebug_host_info *sdbg_host2;

        mutex_lock(&sdebug_host_list_mutex);
        if (!list_empty(&sdebug_host_list)) {
                sdbg_host = list_entry(sdebug_host_list.prev,
                                       struct sdebug_host_info, host_list);
                idx = sdbg_host->si_idx;
        }
        if (!the_end && idx >= 0) {
                bool unique = true;

                list_for_each_entry(sdbg_host2, &sdebug_host_list, host_list) {
                        if (sdbg_host2 == sdbg_host)
                                continue;
                        if (idx == sdbg_host2->si_idx) {
                                unique = false;
                                break;
                        }
                }
                if (unique) {
                        xa_set_mark(per_store_ap, idx, SDEB_XA_NOT_IN_USE);
                        if (idx == sdeb_most_recent_idx)
                                --sdeb_most_recent_idx;
                }
        }
        if (sdbg_host)
                list_del(&sdbg_host->host_list);
        mutex_unlock(&sdebug_host_list_mutex);

        if (!sdbg_host)
                return;

        device_unregister(&sdbg_host->dev);
        --sdebug_num_hosts;
}

static int sdebug_change_qdepth(struct scsi_device *sdev, int qdepth)
{
        struct sdebug_dev_info *devip = sdev->hostdata;

        if (!devip)
                return  -ENODEV;

        mutex_lock(&sdebug_host_list_mutex);
        block_unblock_all_queues(true);

        if (qdepth > SDEBUG_CANQUEUE) {
                qdepth = SDEBUG_CANQUEUE;
                pr_warn("%s: requested qdepth [%d] exceeds canqueue [%d], trim\n", __func__,
                        qdepth, SDEBUG_CANQUEUE);
        }
        if (qdepth < 1)
                qdepth = 1;
        if (qdepth != sdev->queue_depth)
                scsi_change_queue_depth(sdev, qdepth);

        block_unblock_all_queues(false);
        mutex_unlock(&sdebug_host_list_mutex);

        if (SDEBUG_OPT_Q_NOISE & sdebug_opts)
                sdev_printk(KERN_INFO, sdev, "%s: qdepth=%d\n", __func__, qdepth);

        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;
}

/* Response to TUR or media access command when device stopped */
static int resp_not_ready(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
{
        int stopped_state;
        u64 diff_ns = 0;
        ktime_t now_ts = ktime_get_boottime();
        struct scsi_device *sdp = scp->device;

        stopped_state = atomic_read(&devip->stopped);
        if (stopped_state == 2) {
                if (ktime_to_ns(now_ts) > ktime_to_ns(devip->create_ts)) {
                        diff_ns = ktime_to_ns(ktime_sub(now_ts, devip->create_ts));
                        if (diff_ns >= ((u64)sdeb_tur_ms_to_ready * 1000000)) {
                                /* tur_ms_to_ready timer extinguished */
                                atomic_set(&devip->stopped, 0);
                                return 0;
                        }
                }
                mk_sense_buffer(scp, NOT_READY, LOGICAL_UNIT_NOT_READY, 0x1);
                if (sdebug_verbose)
                        sdev_printk(KERN_INFO, sdp,
                                    "%s: Not ready: in process of becoming ready\n", my_name);
                if (scp->cmnd[0] == TEST_UNIT_READY) {
                        u64 tur_nanosecs_to_ready = (u64)sdeb_tur_ms_to_ready * 1000000;

                        if (diff_ns <= tur_nanosecs_to_ready)
                                diff_ns = tur_nanosecs_to_ready - diff_ns;
                        else
                                diff_ns = tur_nanosecs_to_ready;
                        /* As per 20-061r2 approved for spc6 by T10 on 20200716 */
                        do_div(diff_ns, 1000000);       /* diff_ns becomes milliseconds */
                        scsi_set_sense_information(scp->sense_buffer, SCSI_SENSE_BUFFERSIZE,
                                                   diff_ns);
                        return check_condition_result;
                }
        }
        mk_sense_buffer(scp, NOT_READY, LOGICAL_UNIT_NOT_READY, 0x2);
        if (sdebug_verbose)
                sdev_printk(KERN_INFO, sdp, "%s: Not ready: initializing command required\n",
                            my_name);
        return check_condition_result;
}

static void sdebug_map_queues(struct Scsi_Host *shost)
{
        int i, qoff;

        if (shost->nr_hw_queues == 1)
                return;

        for (i = 0, qoff = 0; i < HCTX_MAX_TYPES; i++) {
                struct blk_mq_queue_map *map = &shost->tag_set.map[i];

                map->nr_queues  = 0;

                if (i == HCTX_TYPE_DEFAULT)
                        map->nr_queues = submit_queues - poll_queues;
                else if (i == HCTX_TYPE_POLL)
                        map->nr_queues = poll_queues;

                if (!map->nr_queues) {
                        BUG_ON(i == HCTX_TYPE_DEFAULT);
                        continue;
                }

                map->queue_offset = qoff;
                blk_mq_map_queues(map);

                qoff += map->nr_queues;
        }
}

struct sdebug_blk_mq_poll_data {
        unsigned int queue_num;
        int *num_entries;
};

/*
 * We don't handle aborted commands here, but it does not seem possible to have
 * aborted polled commands from schedule_resp()
 */
static bool sdebug_blk_mq_poll_iter(struct request *rq, void *opaque)
{
        struct sdebug_blk_mq_poll_data *data = opaque;
        struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
        struct sdebug_scsi_cmd *sdsc = scsi_cmd_priv(cmd);
        struct sdebug_defer *sd_dp;
        u32 unique_tag = blk_mq_unique_tag(rq);
        u16 hwq = blk_mq_unique_tag_to_hwq(unique_tag);
        struct sdebug_queued_cmd *sqcp;
        unsigned long flags;
        int queue_num = data->queue_num;
        ktime_t time;

        /* We're only interested in one queue for this iteration */
        if (hwq != queue_num)
                return true;

        /* Subsequent checks would fail if this failed, but check anyway */
        if (!test_bit(SCMD_STATE_INFLIGHT, &cmd->state))
                return true;

        time = ktime_get_boottime();

        spin_lock_irqsave(&sdsc->lock, flags);
        sqcp = TO_QUEUED_CMD(cmd);
        if (!sqcp) {
                spin_unlock_irqrestore(&sdsc->lock, flags);
                return true;
        }

        sd_dp = &sqcp->sd_dp;
        if (READ_ONCE(sd_dp->defer_t) != SDEB_DEFER_POLL) {
                spin_unlock_irqrestore(&sdsc->lock, flags);
                return true;
        }

        if (time < sd_dp->cmpl_ts) {
                spin_unlock_irqrestore(&sdsc->lock, flags);
                return true;
        }

        ASSIGN_QUEUED_CMD(cmd, NULL);
        spin_unlock_irqrestore(&sdsc->lock, flags);

        if (sdebug_statistics) {
                atomic_inc(&sdebug_completions);
                if (raw_smp_processor_id() != sd_dp->issuing_cpu)
                        atomic_inc(&sdebug_miss_cpus);
        }

        sdebug_free_queued_cmd(sqcp);

        scsi_done(cmd); /* callback to mid level */
        (*data->num_entries)++;
        return true;
}

static int sdebug_blk_mq_poll(struct Scsi_Host *shost, unsigned int queue_num)
{
        int num_entries = 0;
        struct sdebug_blk_mq_poll_data data = {
                .queue_num = queue_num,
                .num_entries = &num_entries,
        };

        blk_mq_tagset_busy_iter(&shost->tag_set, sdebug_blk_mq_poll_iter,
                                &data);

        if (num_entries > 0)
                atomic_add(num_entries, &sdeb_mq_poll_count);
        return num_entries;
}

static int sdebug_timeout_cmd(struct scsi_cmnd *cmnd)
{
        struct scsi_device *sdp = cmnd->device;
        struct sdebug_dev_info *devip = (struct sdebug_dev_info *)sdp->hostdata;
        struct sdebug_err_inject *err;
        unsigned char *cmd = cmnd->cmnd;
        int ret = 0;

        if (devip == NULL)
                return 0;

        rcu_read_lock();
        list_for_each_entry_rcu(err, &devip->inject_err_list, list) {
                if (err->type == ERR_TMOUT_CMD &&
                    (err->cmd == cmd[0] || err->cmd == 0xff)) {
                        ret = !!err->cnt;
                        if (err->cnt < 0)
                                err->cnt++;

                        rcu_read_unlock();
                        return ret;
                }
        }
        rcu_read_unlock();

        return 0;
}

static int sdebug_fail_queue_cmd(struct scsi_cmnd *cmnd)
{
        struct scsi_device *sdp = cmnd->device;
        struct sdebug_dev_info *devip = (struct sdebug_dev_info *)sdp->hostdata;
        struct sdebug_err_inject *err;
        unsigned char *cmd = cmnd->cmnd;
        int ret = 0;

        if (devip == NULL)
                return 0;

        rcu_read_lock();
        list_for_each_entry_rcu(err, &devip->inject_err_list, list) {
                if (err->type == ERR_FAIL_QUEUE_CMD &&
                    (err->cmd == cmd[0] || err->cmd == 0xff)) {
                        ret = err->cnt ? err->queuecmd_ret : 0;
                        if (err->cnt < 0)
                                err->cnt++;

                        rcu_read_unlock();
                        return ret;
                }
        }
        rcu_read_unlock();

        return 0;
}

static int sdebug_fail_cmd(struct scsi_cmnd *cmnd, int *retval,
                           struct sdebug_err_inject *info)
{
        struct scsi_device *sdp = cmnd->device;
        struct sdebug_dev_info *devip = (struct sdebug_dev_info *)sdp->hostdata;
        struct sdebug_err_inject *err;
        unsigned char *cmd = cmnd->cmnd;
        int ret = 0;
        int result;

        if (devip == NULL)
                return 0;

        rcu_read_lock();
        list_for_each_entry_rcu(err, &devip->inject_err_list, list) {
                if (err->type == ERR_FAIL_CMD &&
                    (err->cmd == cmd[0] || err->cmd == 0xff)) {
                        if (!err->cnt) {
                                rcu_read_unlock();
                                return 0;
                        }

                        ret = !!err->cnt;
                        rcu_read_unlock();
                        goto out_handle;
                }
        }
        rcu_read_unlock();

        return 0;

out_handle:
        if (err->cnt < 0)
                err->cnt++;
        mk_sense_buffer(cmnd, err->sense_key, err->asc, err->asq);
        result = err->status_byte | err->host_byte << 16 | err->driver_byte << 24;
        *info = *err;
        *retval = schedule_resp(cmnd, devip, result, NULL, 0, 0);

        return ret;
}

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;
        u64 lun_index = sdp->lun & 0x3FFF;
        u32 flags;
        u16 sa;
        u8 opcode = cmd[0];
        bool has_wlun_rl;
        bool inject_now;
        int ret = 0;
        struct sdebug_err_inject err;

        scsi_set_resid(scp, 0);
        if (sdebug_statistics) {
                atomic_inc(&sdebug_cmnd_count);
                inject_now = inject_on_this_cmd();
        } else {
                inject_now = false;
        }
        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(scsi_cmd_to_rq(scp)), b);
        }
        if (unlikely(inject_now && (sdebug_opts & SDEBUG_OPT_HOST_BUSY)))
                return SCSI_MLQUEUE_HOST_BUSY;
        has_wlun_rl = (sdp->lun == SCSI_W_LUN_REPORT_LUNS);
        if (unlikely(lun_index >= 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;
        }

        if (sdebug_timeout_cmd(scp)) {
                scmd_printk(KERN_INFO, scp, "timeout command 0x%x\n", opcode);
                return 0;
        }

        ret = sdebug_fail_queue_cmd(scp);
        if (ret) {
                scmd_printk(KERN_INFO, scp, "fail queue command 0x%x with 0x%x\n",
                                opcode, ret);
                return ret;
        }

        if (sdebug_fail_cmd(scp, &ret, &err)) {
                scmd_printk(KERN_INFO, scp,
                        "fail command 0x%x with hostbyte=0x%x, "
                        "driverbyte=0x%x, statusbyte=0x%x, "
                        "sense_key=0x%x, asc=0x%x, asq=0x%x\n",
                        opcode, err.host_byte, err.driver_byte,
                        err.status_byte, err.sense_key, err.asc, err.asq);
                return ret;
        }

        if (unlikely(inject_now && !atomic_read(&sdeb_inject_pending)))
                atomic_set(&sdeb_inject_pending, 1);

        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) || scp->cmnd[0] == TEST_UNIT_READY) &&
                     atomic_read(&devip->stopped))) {
                errsts = resp_not_ready(scp, devip);
                if (errsts)
                        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)      /* cmds like INQUIRY respond asap */
                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 int sdebug_init_cmd_priv(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
{
        struct sdebug_scsi_cmd *sdsc = scsi_cmd_priv(cmd);

        spin_lock_init(&sdsc->lock);

        return 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,
        .map_queues =           sdebug_map_queues,
        .mq_poll =              sdebug_blk_mq_poll,
        .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,
        .cmd_size = sizeof(struct sdebug_scsi_cmd),
        .init_cmd_priv = sdebug_init_cmd_priv,
        .target_alloc =         sdebug_target_alloc,
        .target_destroy =       sdebug_target_destroy,
};

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 = dev_to_sdebug_host(dev);

        sdebug_driver_template.can_queue = sdebug_max_queue;
        sdebug_driver_template.cmd_per_lun = sdebug_max_queue;
        if (!sdebug_clustering)
                sdebug_driver_template.dma_boundary = PAGE_SIZE - 1;

        hpnt = scsi_host_alloc(&sdebug_driver_template, 0);
        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. The
         * following should give the same answer for each host.
         */
        hpnt->nr_hw_queues = submit_queues;
        if (sdebug_host_max_queue)
                hpnt->host_tagset = 1;

        /* poll queues are possible for nr_hw_queues > 1 */
        if (hpnt->nr_hw_queues == 1 || (poll_queues < 1)) {
                pr_warn("%s: trim poll_queues to 0. poll_q/nr_hw = (%d/%d)\n",
                         my_name, poll_queues, hpnt->nr_hw_queues);
                poll_queues = 0;
        }

        /*
         * Poll queues don't need interrupts, but we need at least one I/O queue
         * left over for non-polled I/O.
         * If condition not met, trim poll_queues to 1 (just for simplicity).
         */
        if (poll_queues >= submit_queues) {
                if (submit_queues < 3)
                        pr_warn("%s: trim poll_queues to 1\n", my_name);
                else
                        pr_warn("%s: trim poll_queues to 1. Perhaps try poll_queues=%d\n",
                                my_name, submit_queues - 1);
                poll_queues = 1;
        }
        if (poll_queues)
                hpnt->nr_maps = 3;

        sdbg_host->shost = hpnt;
        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 void sdebug_driver_remove(struct device *dev)
{
        struct sdebug_host_info *sdbg_host;
        struct sdebug_dev_info *sdbg_devinfo, *tmp;

        sdbg_host = dev_to_sdebug_host(dev);

        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->zstate);
                kfree(sdbg_devinfo);
        }

        scsi_host_put(sdbg_host->shost);
}

static struct bus_type pseudo_lld_bus = {
        .name = "pseudo",
        .probe = sdebug_driver_probe,
        .remove = sdebug_driver_remove,
        .drv_groups = sdebug_drv_groups,
};