linux/drivers/scsi/scsi_error.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  scsi_error.c Copyright (C) 1997 Eric Youngdale
   4 *
   5 *  SCSI error/timeout handling
   6 *      Initial versions: Eric Youngdale.  Based upon conversations with
   7 *                        Leonard Zubkoff and David Miller at Linux Expo,
   8 *                        ideas originating from all over the place.
   9 *
  10 *      Restructured scsi_unjam_host and associated functions.
  11 *      September 04, 2002 Mike Anderson (andmike@us.ibm.com)
  12 *
  13 *      Forward port of Russell King's (rmk@arm.linux.org.uk) changes and
  14 *      minor cleanups.
  15 *      September 30, 2002 Mike Anderson (andmike@us.ibm.com)
  16 */
  17
  18#include <linux/module.h>
  19#include <linux/sched.h>
  20#include <linux/gfp.h>
  21#include <linux/timer.h>
  22#include <linux/string.h>
  23#include <linux/kernel.h>
  24#include <linux/freezer.h>
  25#include <linux/kthread.h>
  26#include <linux/interrupt.h>
  27#include <linux/blkdev.h>
  28#include <linux/delay.h>
  29#include <linux/jiffies.h>
  30
  31#include <scsi/scsi.h>
  32#include <scsi/scsi_cmnd.h>
  33#include <scsi/scsi_dbg.h>
  34#include <scsi/scsi_device.h>
  35#include <scsi/scsi_driver.h>
  36#include <scsi/scsi_eh.h>
  37#include <scsi/scsi_common.h>
  38#include <scsi/scsi_transport.h>
  39#include <scsi/scsi_host.h>
  40#include <scsi/scsi_ioctl.h>
  41#include <scsi/scsi_dh.h>
  42#include <scsi/scsi_devinfo.h>
  43#include <scsi/sg.h>
  44
  45#include "scsi_priv.h"
  46#include "scsi_logging.h"
  47#include "scsi_transport_api.h"
  48
  49#include <trace/events/scsi.h>
  50
  51#include <asm/unaligned.h>
  52
  53static void scsi_eh_done(struct scsi_cmnd *scmd);
  54
  55/*
  56 * These should *probably* be handled by the host itself.
  57 * Since it is allowed to sleep, it probably should.
  58 */
  59#define BUS_RESET_SETTLE_TIME   (10)
  60#define HOST_RESET_SETTLE_TIME  (10)
  61
  62static int scsi_eh_try_stu(struct scsi_cmnd *scmd);
  63static enum scsi_disposition scsi_try_to_abort_cmd(struct scsi_host_template *,
  64                                                   struct scsi_cmnd *);
  65
  66void scsi_eh_wakeup(struct Scsi_Host *shost)
  67{
  68        lockdep_assert_held(shost->host_lock);
  69
  70        if (scsi_host_busy(shost) == shost->host_failed) {
  71                trace_scsi_eh_wakeup(shost);
  72                wake_up_process(shost->ehandler);
  73                SCSI_LOG_ERROR_RECOVERY(5, shost_printk(KERN_INFO, shost,
  74                        "Waking error handler thread\n"));
  75        }
  76}
  77
  78/**
  79 * scsi_schedule_eh - schedule EH for SCSI host
  80 * @shost:      SCSI host to invoke error handling on.
  81 *
  82 * Schedule SCSI EH without scmd.
  83 */
  84void scsi_schedule_eh(struct Scsi_Host *shost)
  85{
  86        unsigned long flags;
  87
  88        spin_lock_irqsave(shost->host_lock, flags);
  89
  90        if (scsi_host_set_state(shost, SHOST_RECOVERY) == 0 ||
  91            scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY) == 0) {
  92                shost->host_eh_scheduled++;
  93                scsi_eh_wakeup(shost);
  94        }
  95
  96        spin_unlock_irqrestore(shost->host_lock, flags);
  97}
  98EXPORT_SYMBOL_GPL(scsi_schedule_eh);
  99
 100static int scsi_host_eh_past_deadline(struct Scsi_Host *shost)
 101{
 102        if (!shost->last_reset || shost->eh_deadline == -1)
 103                return 0;
 104
 105        /*
 106         * 32bit accesses are guaranteed to be atomic
 107         * (on all supported architectures), so instead
 108         * of using a spinlock we can as well double check
 109         * if eh_deadline has been set to 'off' during the
 110         * time_before call.
 111         */
 112        if (time_before(jiffies, shost->last_reset + shost->eh_deadline) &&
 113            shost->eh_deadline > -1)
 114                return 0;
 115
 116        return 1;
 117}
 118
 119static bool scsi_cmd_retry_allowed(struct scsi_cmnd *cmd)
 120{
 121        if (cmd->allowed == SCSI_CMD_RETRIES_NO_LIMIT)
 122                return true;
 123
 124        return ++cmd->retries <= cmd->allowed;
 125}
 126
 127static bool scsi_eh_should_retry_cmd(struct scsi_cmnd *cmd)
 128{
 129        struct scsi_device *sdev = cmd->device;
 130        struct Scsi_Host *host = sdev->host;
 131
 132        if (host->hostt->eh_should_retry_cmd)
 133                return  host->hostt->eh_should_retry_cmd(cmd);
 134
 135        return true;
 136}
 137
 138/**
 139 * scmd_eh_abort_handler - Handle command aborts
 140 * @work:       command to be aborted.
 141 *
 142 * Note: this function must be called only for a command that has timed out.
 143 * Because the block layer marks a request as complete before it calls
 144 * scsi_times_out(), a .scsi_done() call from the LLD for a command that has
 145 * timed out do not have any effect. Hence it is safe to call
 146 * scsi_finish_command() from this function.
 147 */
 148void
 149scmd_eh_abort_handler(struct work_struct *work)
 150{
 151        struct scsi_cmnd *scmd =
 152                container_of(work, struct scsi_cmnd, abort_work.work);
 153        struct scsi_device *sdev = scmd->device;
 154        enum scsi_disposition rtn;
 155
 156        if (scsi_host_eh_past_deadline(sdev->host)) {
 157                SCSI_LOG_ERROR_RECOVERY(3,
 158                        scmd_printk(KERN_INFO, scmd,
 159                                    "eh timeout, not aborting\n"));
 160        } else {
 161                SCSI_LOG_ERROR_RECOVERY(3,
 162                        scmd_printk(KERN_INFO, scmd,
 163                                    "aborting command\n"));
 164                rtn = scsi_try_to_abort_cmd(sdev->host->hostt, scmd);
 165                if (rtn == SUCCESS) {
 166                        set_host_byte(scmd, DID_TIME_OUT);
 167                        if (scsi_host_eh_past_deadline(sdev->host)) {
 168                                SCSI_LOG_ERROR_RECOVERY(3,
 169                                        scmd_printk(KERN_INFO, scmd,
 170                                                    "eh timeout, not retrying "
 171                                                    "aborted command\n"));
 172                        } else if (!scsi_noretry_cmd(scmd) &&
 173                                   scsi_cmd_retry_allowed(scmd) &&
 174                                scsi_eh_should_retry_cmd(scmd)) {
 175                                SCSI_LOG_ERROR_RECOVERY(3,
 176                                        scmd_printk(KERN_WARNING, scmd,
 177                                                    "retry aborted command\n"));
 178                                scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY);
 179                                return;
 180                        } else {
 181                                SCSI_LOG_ERROR_RECOVERY(3,
 182                                        scmd_printk(KERN_WARNING, scmd,
 183                                                    "finish aborted command\n"));
 184                                scsi_finish_command(scmd);
 185                                return;
 186                        }
 187                } else {
 188                        SCSI_LOG_ERROR_RECOVERY(3,
 189                                scmd_printk(KERN_INFO, scmd,
 190                                            "cmd abort %s\n",
 191                                            (rtn == FAST_IO_FAIL) ?
 192                                            "not send" : "failed"));
 193                }
 194        }
 195
 196        scsi_eh_scmd_add(scmd);
 197}
 198
 199/**
 200 * scsi_abort_command - schedule a command abort
 201 * @scmd:       scmd to abort.
 202 *
 203 * We only need to abort commands after a command timeout
 204 */
 205static int
 206scsi_abort_command(struct scsi_cmnd *scmd)
 207{
 208        struct scsi_device *sdev = scmd->device;
 209        struct Scsi_Host *shost = sdev->host;
 210        unsigned long flags;
 211
 212        if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) {
 213                /*
 214                 * Retry after abort failed, escalate to next level.
 215                 */
 216                SCSI_LOG_ERROR_RECOVERY(3,
 217                        scmd_printk(KERN_INFO, scmd,
 218                                    "previous abort failed\n"));
 219                BUG_ON(delayed_work_pending(&scmd->abort_work));
 220                return FAILED;
 221        }
 222
 223        spin_lock_irqsave(shost->host_lock, flags);
 224        if (shost->eh_deadline != -1 && !shost->last_reset)
 225                shost->last_reset = jiffies;
 226        spin_unlock_irqrestore(shost->host_lock, flags);
 227
 228        scmd->eh_eflags |= SCSI_EH_ABORT_SCHEDULED;
 229        SCSI_LOG_ERROR_RECOVERY(3,
 230                scmd_printk(KERN_INFO, scmd, "abort scheduled\n"));
 231        queue_delayed_work(shost->tmf_work_q, &scmd->abort_work, HZ / 100);
 232        return SUCCESS;
 233}
 234
 235/**
 236 * scsi_eh_reset - call into ->eh_action to reset internal counters
 237 * @scmd:       scmd to run eh on.
 238 *
 239 * The scsi driver might be carrying internal state about the
 240 * devices, so we need to call into the driver to reset the
 241 * internal state once the error handler is started.
 242 */
 243static void scsi_eh_reset(struct scsi_cmnd *scmd)
 244{
 245        if (!blk_rq_is_passthrough(scmd->request)) {
 246                struct scsi_driver *sdrv = scsi_cmd_to_driver(scmd);
 247                if (sdrv->eh_reset)
 248                        sdrv->eh_reset(scmd);
 249        }
 250}
 251
 252static void scsi_eh_inc_host_failed(struct rcu_head *head)
 253{
 254        struct scsi_cmnd *scmd = container_of(head, typeof(*scmd), rcu);
 255        struct Scsi_Host *shost = scmd->device->host;
 256        unsigned long flags;
 257
 258        spin_lock_irqsave(shost->host_lock, flags);
 259        shost->host_failed++;
 260        scsi_eh_wakeup(shost);
 261        spin_unlock_irqrestore(shost->host_lock, flags);
 262}
 263
 264/**
 265 * scsi_eh_scmd_add - add scsi cmd to error handling.
 266 * @scmd:       scmd to run eh on.
 267 */
 268void scsi_eh_scmd_add(struct scsi_cmnd *scmd)
 269{
 270        struct Scsi_Host *shost = scmd->device->host;
 271        unsigned long flags;
 272        int ret;
 273
 274        WARN_ON_ONCE(!shost->ehandler);
 275
 276        spin_lock_irqsave(shost->host_lock, flags);
 277        if (scsi_host_set_state(shost, SHOST_RECOVERY)) {
 278                ret = scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY);
 279                WARN_ON_ONCE(ret);
 280        }
 281        if (shost->eh_deadline != -1 && !shost->last_reset)
 282                shost->last_reset = jiffies;
 283
 284        scsi_eh_reset(scmd);
 285        list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q);
 286        spin_unlock_irqrestore(shost->host_lock, flags);
 287        /*
 288         * Ensure that all tasks observe the host state change before the
 289         * host_failed change.
 290         */
 291        call_rcu(&scmd->rcu, scsi_eh_inc_host_failed);
 292}
 293
 294/**
 295 * scsi_times_out - Timeout function for normal scsi commands.
 296 * @req:        request that is timing out.
 297 *
 298 * Notes:
 299 *     We do not need to lock this.  There is the potential for a race
 300 *     only in that the normal completion handling might run, but if the
 301 *     normal completion function determines that the timer has already
 302 *     fired, then it mustn't do anything.
 303 */
 304enum blk_eh_timer_return scsi_times_out(struct request *req)
 305{
 306        struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(req);
 307        enum blk_eh_timer_return rtn = BLK_EH_DONE;
 308        struct Scsi_Host *host = scmd->device->host;
 309
 310        trace_scsi_dispatch_cmd_timeout(scmd);
 311        scsi_log_completion(scmd, TIMEOUT_ERROR);
 312
 313        if (host->eh_deadline != -1 && !host->last_reset)
 314                host->last_reset = jiffies;
 315
 316        if (host->hostt->eh_timed_out)
 317                rtn = host->hostt->eh_timed_out(scmd);
 318
 319        if (rtn == BLK_EH_DONE) {
 320                /*
 321                 * Set the command to complete first in order to prevent a real
 322                 * completion from releasing the command while error handling
 323                 * is using it. If the command was already completed, then the
 324                 * lower level driver beat the timeout handler, and it is safe
 325                 * to return without escalating error recovery.
 326                 *
 327                 * If timeout handling lost the race to a real completion, the
 328                 * block layer may ignore that due to a fake timeout injection,
 329                 * so return RESET_TIMER to allow error handling another shot
 330                 * at this command.
 331                 */
 332                if (test_and_set_bit(SCMD_STATE_COMPLETE, &scmd->state))
 333                        return BLK_EH_RESET_TIMER;
 334                if (scsi_abort_command(scmd) != SUCCESS) {
 335                        set_host_byte(scmd, DID_TIME_OUT);
 336                        scsi_eh_scmd_add(scmd);
 337                }
 338        }
 339
 340        return rtn;
 341}
 342
 343/**
 344 * scsi_block_when_processing_errors - Prevent cmds from being queued.
 345 * @sdev:       Device on which we are performing recovery.
 346 *
 347 * Description:
 348 *     We block until the host is out of error recovery, and then check to
 349 *     see whether the host or the device is offline.
 350 *
 351 * Return value:
 352 *     0 when dev was taken offline by error recovery. 1 OK to proceed.
 353 */
 354int scsi_block_when_processing_errors(struct scsi_device *sdev)
 355{
 356        int online;
 357
 358        wait_event(sdev->host->host_wait, !scsi_host_in_recovery(sdev->host));
 359
 360        online = scsi_device_online(sdev);
 361
 362        return online;
 363}
 364EXPORT_SYMBOL(scsi_block_when_processing_errors);
 365
 366#ifdef CONFIG_SCSI_LOGGING
 367/**
 368 * scsi_eh_prt_fail_stats - Log info on failures.
 369 * @shost:      scsi host being recovered.
 370 * @work_q:     Queue of scsi cmds to process.
 371 */
 372static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost,
 373                                          struct list_head *work_q)
 374{
 375        struct scsi_cmnd *scmd;
 376        struct scsi_device *sdev;
 377        int total_failures = 0;
 378        int cmd_failed = 0;
 379        int cmd_cancel = 0;
 380        int devices_failed = 0;
 381
 382        shost_for_each_device(sdev, shost) {
 383                list_for_each_entry(scmd, work_q, eh_entry) {
 384                        if (scmd->device == sdev) {
 385                                ++total_failures;
 386                                if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED)
 387                                        ++cmd_cancel;
 388                                else
 389                                        ++cmd_failed;
 390                        }
 391                }
 392
 393                if (cmd_cancel || cmd_failed) {
 394                        SCSI_LOG_ERROR_RECOVERY(3,
 395                                shost_printk(KERN_INFO, shost,
 396                                            "%s: cmds failed: %d, cancel: %d\n",
 397                                            __func__, cmd_failed,
 398                                            cmd_cancel));
 399                        cmd_cancel = 0;
 400                        cmd_failed = 0;
 401                        ++devices_failed;
 402                }
 403        }
 404
 405        SCSI_LOG_ERROR_RECOVERY(2, shost_printk(KERN_INFO, shost,
 406                                   "Total of %d commands on %d"
 407                                   " devices require eh work\n",
 408                                   total_failures, devices_failed));
 409}
 410#endif
 411
 412 /**
 413 * scsi_report_lun_change - Set flag on all *other* devices on the same target
 414 *                          to indicate that a UNIT ATTENTION is expected.
 415 * @sdev:       Device reporting the UNIT ATTENTION
 416 */
 417static void scsi_report_lun_change(struct scsi_device *sdev)
 418{
 419        sdev->sdev_target->expecting_lun_change = 1;
 420}
 421
 422/**
 423 * scsi_report_sense - Examine scsi sense information and log messages for
 424 *                     certain conditions, also issue uevents for some of them.
 425 * @sdev:       Device reporting the sense code
 426 * @sshdr:      sshdr to be examined
 427 */
 428static void scsi_report_sense(struct scsi_device *sdev,
 429                              struct scsi_sense_hdr *sshdr)
 430{
 431        enum scsi_device_event evt_type = SDEV_EVT_MAXBITS;     /* i.e. none */
 432
 433        if (sshdr->sense_key == UNIT_ATTENTION) {
 434                if (sshdr->asc == 0x3f && sshdr->ascq == 0x03) {
 435                        evt_type = SDEV_EVT_INQUIRY_CHANGE_REPORTED;
 436                        sdev_printk(KERN_WARNING, sdev,
 437                                    "Inquiry data has changed");
 438                } else if (sshdr->asc == 0x3f && sshdr->ascq == 0x0e) {
 439                        evt_type = SDEV_EVT_LUN_CHANGE_REPORTED;
 440                        scsi_report_lun_change(sdev);
 441                        sdev_printk(KERN_WARNING, sdev,
 442                                    "Warning! Received an indication that the "
 443                                    "LUN assignments on this target have "
 444                                    "changed. The Linux SCSI layer does not "
 445                                    "automatically remap LUN assignments.\n");
 446                } else if (sshdr->asc == 0x3f)
 447                        sdev_printk(KERN_WARNING, sdev,
 448                                    "Warning! Received an indication that the "
 449                                    "operating parameters on this target have "
 450                                    "changed. The Linux SCSI layer does not "
 451                                    "automatically adjust these parameters.\n");
 452
 453                if (sshdr->asc == 0x38 && sshdr->ascq == 0x07) {
 454                        evt_type = SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED;
 455                        sdev_printk(KERN_WARNING, sdev,
 456                                    "Warning! Received an indication that the "
 457                                    "LUN reached a thin provisioning soft "
 458                                    "threshold.\n");
 459                }
 460
 461                if (sshdr->asc == 0x29) {
 462                        evt_type = SDEV_EVT_POWER_ON_RESET_OCCURRED;
 463                        sdev_printk(KERN_WARNING, sdev,
 464                                    "Power-on or device reset occurred\n");
 465                }
 466
 467                if (sshdr->asc == 0x2a && sshdr->ascq == 0x01) {
 468                        evt_type = SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED;
 469                        sdev_printk(KERN_WARNING, sdev,
 470                                    "Mode parameters changed");
 471                } else if (sshdr->asc == 0x2a && sshdr->ascq == 0x06) {
 472                        evt_type = SDEV_EVT_ALUA_STATE_CHANGE_REPORTED;
 473                        sdev_printk(KERN_WARNING, sdev,
 474                                    "Asymmetric access state changed");
 475                } else if (sshdr->asc == 0x2a && sshdr->ascq == 0x09) {
 476                        evt_type = SDEV_EVT_CAPACITY_CHANGE_REPORTED;
 477                        sdev_printk(KERN_WARNING, sdev,
 478                                    "Capacity data has changed");
 479                } else if (sshdr->asc == 0x2a)
 480                        sdev_printk(KERN_WARNING, sdev,
 481                                    "Parameters changed");
 482        }
 483
 484        if (evt_type != SDEV_EVT_MAXBITS) {
 485                set_bit(evt_type, sdev->pending_events);
 486                schedule_work(&sdev->event_work);
 487        }
 488}
 489
 490/**
 491 * scsi_check_sense - Examine scsi cmd sense
 492 * @scmd:       Cmd to have sense checked.
 493 *
 494 * Return value:
 495 *      SUCCESS or FAILED or NEEDS_RETRY or ADD_TO_MLQUEUE
 496 *
 497 * Notes:
 498 *      When a deferred error is detected the current command has
 499 *      not been executed and needs retrying.
 500 */
 501enum scsi_disposition scsi_check_sense(struct scsi_cmnd *scmd)
 502{
 503        struct scsi_device *sdev = scmd->device;
 504        struct scsi_sense_hdr sshdr;
 505
 506        if (! scsi_command_normalize_sense(scmd, &sshdr))
 507                return FAILED;  /* no valid sense data */
 508
 509        scsi_report_sense(sdev, &sshdr);
 510
 511        if (scsi_sense_is_deferred(&sshdr))
 512                return NEEDS_RETRY;
 513
 514        if (sdev->handler && sdev->handler->check_sense) {
 515                enum scsi_disposition rc;
 516
 517                rc = sdev->handler->check_sense(sdev, &sshdr);
 518                if (rc != SCSI_RETURN_NOT_HANDLED)
 519                        return rc;
 520                /* handler does not care. Drop down to default handling */
 521        }
 522
 523        if (scmd->cmnd[0] == TEST_UNIT_READY && scmd->scsi_done != scsi_eh_done)
 524                /*
 525                 * nasty: for mid-layer issued TURs, we need to return the
 526                 * actual sense data without any recovery attempt.  For eh
 527                 * issued ones, we need to try to recover and interpret
 528                 */
 529                return SUCCESS;
 530
 531        /*
 532         * Previous logic looked for FILEMARK, EOM or ILI which are
 533         * mainly associated with tapes and returned SUCCESS.
 534         */
 535        if (sshdr.response_code == 0x70) {
 536                /* fixed format */
 537                if (scmd->sense_buffer[2] & 0xe0)
 538                        return SUCCESS;
 539        } else {
 540                /*
 541                 * descriptor format: look for "stream commands sense data
 542                 * descriptor" (see SSC-3). Assume single sense data
 543                 * descriptor. Ignore ILI from SBC-2 READ LONG and WRITE LONG.
 544                 */
 545                if ((sshdr.additional_length > 3) &&
 546                    (scmd->sense_buffer[8] == 0x4) &&
 547                    (scmd->sense_buffer[11] & 0xe0))
 548                        return SUCCESS;
 549        }
 550
 551        switch (sshdr.sense_key) {
 552        case NO_SENSE:
 553                return SUCCESS;
 554        case RECOVERED_ERROR:
 555                return /* soft_error */ SUCCESS;
 556
 557        case ABORTED_COMMAND:
 558                if (sshdr.asc == 0x10) /* DIF */
 559                        return SUCCESS;
 560
 561                if (sshdr.asc == 0x44 && sdev->sdev_bflags & BLIST_RETRY_ITF)
 562                        return ADD_TO_MLQUEUE;
 563                if (sshdr.asc == 0xc1 && sshdr.ascq == 0x01 &&
 564                    sdev->sdev_bflags & BLIST_RETRY_ASC_C1)
 565                        return ADD_TO_MLQUEUE;
 566
 567                return NEEDS_RETRY;
 568        case NOT_READY:
 569        case UNIT_ATTENTION:
 570                /*
 571                 * if we are expecting a cc/ua because of a bus reset that we
 572                 * performed, treat this just as a retry.  otherwise this is
 573                 * information that we should pass up to the upper-level driver
 574                 * so that we can deal with it there.
 575                 */
 576                if (scmd->device->expecting_cc_ua) {
 577                        /*
 578                         * Because some device does not queue unit
 579                         * attentions correctly, we carefully check
 580                         * additional sense code and qualifier so as
 581                         * not to squash media change unit attention.
 582                         */
 583                        if (sshdr.asc != 0x28 || sshdr.ascq != 0x00) {
 584                                scmd->device->expecting_cc_ua = 0;
 585                                return NEEDS_RETRY;
 586                        }
 587                }
 588                /*
 589                 * we might also expect a cc/ua if another LUN on the target
 590                 * reported a UA with an ASC/ASCQ of 3F 0E -
 591                 * REPORTED LUNS DATA HAS CHANGED.
 592                 */
 593                if (scmd->device->sdev_target->expecting_lun_change &&
 594                    sshdr.asc == 0x3f && sshdr.ascq == 0x0e)
 595                        return NEEDS_RETRY;
 596                /*
 597                 * if the device is in the process of becoming ready, we
 598                 * should retry.
 599                 */
 600                if ((sshdr.asc == 0x04) && (sshdr.ascq == 0x01))
 601                        return NEEDS_RETRY;
 602                /*
 603                 * if the device is not started, we need to wake
 604                 * the error handler to start the motor
 605                 */
 606                if (scmd->device->allow_restart &&
 607                    (sshdr.asc == 0x04) && (sshdr.ascq == 0x02))
 608                        return FAILED;
 609                /*
 610                 * Pass the UA upwards for a determination in the completion
 611                 * functions.
 612                 */
 613                return SUCCESS;
 614
 615                /* these are not supported */
 616        case DATA_PROTECT:
 617                if (sshdr.asc == 0x27 && sshdr.ascq == 0x07) {
 618                        /* Thin provisioning hard threshold reached */
 619                        set_host_byte(scmd, DID_ALLOC_FAILURE);
 620                        return SUCCESS;
 621                }
 622                fallthrough;
 623        case COPY_ABORTED:
 624        case VOLUME_OVERFLOW:
 625        case MISCOMPARE:
 626        case BLANK_CHECK:
 627                set_host_byte(scmd, DID_TARGET_FAILURE);
 628                return SUCCESS;
 629
 630        case MEDIUM_ERROR:
 631                if (sshdr.asc == 0x11 || /* UNRECOVERED READ ERR */
 632                    sshdr.asc == 0x13 || /* AMNF DATA FIELD */
 633                    sshdr.asc == 0x14) { /* RECORD NOT FOUND */
 634                        set_host_byte(scmd, DID_MEDIUM_ERROR);
 635                        return SUCCESS;
 636                }
 637                return NEEDS_RETRY;
 638
 639        case HARDWARE_ERROR:
 640                if (scmd->device->retry_hwerror)
 641                        return ADD_TO_MLQUEUE;
 642                else
 643                        set_host_byte(scmd, DID_TARGET_FAILURE);
 644                fallthrough;
 645
 646        case ILLEGAL_REQUEST:
 647                if (sshdr.asc == 0x20 || /* Invalid command operation code */
 648                    sshdr.asc == 0x21 || /* Logical block address out of range */
 649                    sshdr.asc == 0x22 || /* Invalid function */
 650                    sshdr.asc == 0x24 || /* Invalid field in cdb */
 651                    sshdr.asc == 0x26 || /* Parameter value invalid */
 652                    sshdr.asc == 0x27) { /* Write protected */
 653                        set_host_byte(scmd, DID_TARGET_FAILURE);
 654                }
 655                return SUCCESS;
 656
 657        default:
 658                return SUCCESS;
 659        }
 660}
 661EXPORT_SYMBOL_GPL(scsi_check_sense);
 662
 663static void scsi_handle_queue_ramp_up(struct scsi_device *sdev)
 664{
 665        struct scsi_host_template *sht = sdev->host->hostt;
 666        struct scsi_device *tmp_sdev;
 667
 668        if (!sht->track_queue_depth ||
 669            sdev->queue_depth >= sdev->max_queue_depth)
 670                return;
 671
 672        if (time_before(jiffies,
 673            sdev->last_queue_ramp_up + sdev->queue_ramp_up_period))
 674                return;
 675
 676        if (time_before(jiffies,
 677            sdev->last_queue_full_time + sdev->queue_ramp_up_period))
 678                return;
 679
 680        /*
 681         * Walk all devices of a target and do
 682         * ramp up on them.
 683         */
 684        shost_for_each_device(tmp_sdev, sdev->host) {
 685                if (tmp_sdev->channel != sdev->channel ||
 686                    tmp_sdev->id != sdev->id ||
 687                    tmp_sdev->queue_depth == sdev->max_queue_depth)
 688                        continue;
 689
 690                scsi_change_queue_depth(tmp_sdev, tmp_sdev->queue_depth + 1);
 691                sdev->last_queue_ramp_up = jiffies;
 692        }
 693}
 694
 695static void scsi_handle_queue_full(struct scsi_device *sdev)
 696{
 697        struct scsi_host_template *sht = sdev->host->hostt;
 698        struct scsi_device *tmp_sdev;
 699
 700        if (!sht->track_queue_depth)
 701                return;
 702
 703        shost_for_each_device(tmp_sdev, sdev->host) {
 704                if (tmp_sdev->channel != sdev->channel ||
 705                    tmp_sdev->id != sdev->id)
 706                        continue;
 707                /*
 708                 * We do not know the number of commands that were at
 709                 * the device when we got the queue full so we start
 710                 * from the highest possible value and work our way down.
 711                 */
 712                scsi_track_queue_full(tmp_sdev, tmp_sdev->queue_depth - 1);
 713        }
 714}
 715
 716/**
 717 * scsi_eh_completed_normally - Disposition a eh cmd on return from LLD.
 718 * @scmd:       SCSI cmd to examine.
 719 *
 720 * Notes:
 721 *    This is *only* called when we are examining the status of commands
 722 *    queued during error recovery.  the main difference here is that we
 723 *    don't allow for the possibility of retries here, and we are a lot
 724 *    more restrictive about what we consider acceptable.
 725 */
 726static enum scsi_disposition scsi_eh_completed_normally(struct scsi_cmnd *scmd)
 727{
 728        /*
 729         * first check the host byte, to see if there is anything in there
 730         * that would indicate what we need to do.
 731         */
 732        if (host_byte(scmd->result) == DID_RESET) {
 733                /*
 734                 * rats.  we are already in the error handler, so we now
 735                 * get to try and figure out what to do next.  if the sense
 736                 * is valid, we have a pretty good idea of what to do.
 737                 * if not, we mark it as FAILED.
 738                 */
 739                return scsi_check_sense(scmd);
 740        }
 741        if (host_byte(scmd->result) != DID_OK)
 742                return FAILED;
 743
 744        /*
 745         * now, check the status byte to see if this indicates
 746         * anything special.
 747         */
 748        switch (get_status_byte(scmd)) {
 749        case SAM_STAT_GOOD:
 750                scsi_handle_queue_ramp_up(scmd->device);
 751                fallthrough;
 752        case SAM_STAT_COMMAND_TERMINATED:
 753                return SUCCESS;
 754        case SAM_STAT_CHECK_CONDITION:
 755                return scsi_check_sense(scmd);
 756        case SAM_STAT_CONDITION_MET:
 757        case SAM_STAT_INTERMEDIATE:
 758        case SAM_STAT_INTERMEDIATE_CONDITION_MET:
 759                /*
 760                 * who knows?  FIXME(eric)
 761                 */
 762                return SUCCESS;
 763        case SAM_STAT_RESERVATION_CONFLICT:
 764                if (scmd->cmnd[0] == TEST_UNIT_READY)
 765                        /* it is a success, we probed the device and
 766                         * found it */
 767                        return SUCCESS;
 768                /* otherwise, we failed to send the command */
 769                return FAILED;
 770        case SAM_STAT_TASK_SET_FULL:
 771                scsi_handle_queue_full(scmd->device);
 772                fallthrough;
 773        case SAM_STAT_BUSY:
 774                return NEEDS_RETRY;
 775        default:
 776                return FAILED;
 777        }
 778        return FAILED;
 779}
 780
 781/**
 782 * scsi_eh_done - Completion function for error handling.
 783 * @scmd:       Cmd that is done.
 784 */
 785static void scsi_eh_done(struct scsi_cmnd *scmd)
 786{
 787        struct completion *eh_action;
 788
 789        SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
 790                        "%s result: %x\n", __func__, scmd->result));
 791
 792        eh_action = scmd->device->host->eh_action;
 793        if (eh_action)
 794                complete(eh_action);
 795}
 796
 797/**
 798 * scsi_try_host_reset - ask host adapter to reset itself
 799 * @scmd:       SCSI cmd to send host reset.
 800 */
 801static enum scsi_disposition scsi_try_host_reset(struct scsi_cmnd *scmd)
 802{
 803        unsigned long flags;
 804        enum scsi_disposition rtn;
 805        struct Scsi_Host *host = scmd->device->host;
 806        struct scsi_host_template *hostt = host->hostt;
 807
 808        SCSI_LOG_ERROR_RECOVERY(3,
 809                shost_printk(KERN_INFO, host, "Snd Host RST\n"));
 810
 811        if (!hostt->eh_host_reset_handler)
 812                return FAILED;
 813
 814        rtn = hostt->eh_host_reset_handler(scmd);
 815
 816        if (rtn == SUCCESS) {
 817                if (!hostt->skip_settle_delay)
 818                        ssleep(HOST_RESET_SETTLE_TIME);
 819                spin_lock_irqsave(host->host_lock, flags);
 820                scsi_report_bus_reset(host, scmd_channel(scmd));
 821                spin_unlock_irqrestore(host->host_lock, flags);
 822        }
 823
 824        return rtn;
 825}
 826
 827/**
 828 * scsi_try_bus_reset - ask host to perform a bus reset
 829 * @scmd:       SCSI cmd to send bus reset.
 830 */
 831static enum scsi_disposition scsi_try_bus_reset(struct scsi_cmnd *scmd)
 832{
 833        unsigned long flags;
 834        enum scsi_disposition rtn;
 835        struct Scsi_Host *host = scmd->device->host;
 836        struct scsi_host_template *hostt = host->hostt;
 837
 838        SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
 839                "%s: Snd Bus RST\n", __func__));
 840
 841        if (!hostt->eh_bus_reset_handler)
 842                return FAILED;
 843
 844        rtn = hostt->eh_bus_reset_handler(scmd);
 845
 846        if (rtn == SUCCESS) {
 847                if (!hostt->skip_settle_delay)
 848                        ssleep(BUS_RESET_SETTLE_TIME);
 849                spin_lock_irqsave(host->host_lock, flags);
 850                scsi_report_bus_reset(host, scmd_channel(scmd));
 851                spin_unlock_irqrestore(host->host_lock, flags);
 852        }
 853
 854        return rtn;
 855}
 856
 857static void __scsi_report_device_reset(struct scsi_device *sdev, void *data)
 858{
 859        sdev->was_reset = 1;
 860        sdev->expecting_cc_ua = 1;
 861}
 862
 863/**
 864 * scsi_try_target_reset - Ask host to perform a target reset
 865 * @scmd:       SCSI cmd used to send a target reset
 866 *
 867 * Notes:
 868 *    There is no timeout for this operation.  if this operation is
 869 *    unreliable for a given host, then the host itself needs to put a
 870 *    timer on it, and set the host back to a consistent state prior to
 871 *    returning.
 872 */
 873static enum scsi_disposition scsi_try_target_reset(struct scsi_cmnd *scmd)
 874{
 875        unsigned long flags;
 876        enum scsi_disposition rtn;
 877        struct Scsi_Host *host = scmd->device->host;
 878        struct scsi_host_template *hostt = host->hostt;
 879
 880        if (!hostt->eh_target_reset_handler)
 881                return FAILED;
 882
 883        rtn = hostt->eh_target_reset_handler(scmd);
 884        if (rtn == SUCCESS) {
 885                spin_lock_irqsave(host->host_lock, flags);
 886                __starget_for_each_device(scsi_target(scmd->device), NULL,
 887                                          __scsi_report_device_reset);
 888                spin_unlock_irqrestore(host->host_lock, flags);
 889        }
 890
 891        return rtn;
 892}
 893
 894/**
 895 * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev
 896 * @scmd:       SCSI cmd used to send BDR
 897 *
 898 * Notes:
 899 *    There is no timeout for this operation.  if this operation is
 900 *    unreliable for a given host, then the host itself needs to put a
 901 *    timer on it, and set the host back to a consistent state prior to
 902 *    returning.
 903 */
 904static enum scsi_disposition scsi_try_bus_device_reset(struct scsi_cmnd *scmd)
 905{
 906        enum scsi_disposition rtn;
 907        struct scsi_host_template *hostt = scmd->device->host->hostt;
 908
 909        if (!hostt->eh_device_reset_handler)
 910                return FAILED;
 911
 912        rtn = hostt->eh_device_reset_handler(scmd);
 913        if (rtn == SUCCESS)
 914                __scsi_report_device_reset(scmd->device, NULL);
 915        return rtn;
 916}
 917
 918/**
 919 * scsi_try_to_abort_cmd - Ask host to abort a SCSI command
 920 * @hostt:      SCSI driver host template
 921 * @scmd:       SCSI cmd used to send a target reset
 922 *
 923 * Return value:
 924 *      SUCCESS, FAILED, or FAST_IO_FAIL
 925 *
 926 * Notes:
 927 *    SUCCESS does not necessarily indicate that the command
 928 *    has been aborted; it only indicates that the LLDDs
 929 *    has cleared all references to that command.
 930 *    LLDDs should return FAILED only if an abort was required
 931 *    but could not be executed. LLDDs should return FAST_IO_FAIL
 932 *    if the device is temporarily unavailable (eg due to a
 933 *    link down on FibreChannel)
 934 */
 935static enum scsi_disposition
 936scsi_try_to_abort_cmd(struct scsi_host_template *hostt, struct scsi_cmnd *scmd)
 937{
 938        if (!hostt->eh_abort_handler)
 939                return FAILED;
 940
 941        return hostt->eh_abort_handler(scmd);
 942}
 943
 944static void scsi_abort_eh_cmnd(struct scsi_cmnd *scmd)
 945{
 946        if (scsi_try_to_abort_cmd(scmd->device->host->hostt, scmd) != SUCCESS)
 947                if (scsi_try_bus_device_reset(scmd) != SUCCESS)
 948                        if (scsi_try_target_reset(scmd) != SUCCESS)
 949                                if (scsi_try_bus_reset(scmd) != SUCCESS)
 950                                        scsi_try_host_reset(scmd);
 951}
 952
 953/**
 954 * scsi_eh_prep_cmnd  - Save a scsi command info as part of error recovery
 955 * @scmd:       SCSI command structure to hijack
 956 * @ses:        structure to save restore information
 957 * @cmnd:       CDB to send. Can be NULL if no new cmnd is needed
 958 * @cmnd_size:  size in bytes of @cmnd (must be <= BLK_MAX_CDB)
 959 * @sense_bytes: size of sense data to copy. or 0 (if != 0 @cmnd is ignored)
 960 *
 961 * This function is used to save a scsi command information before re-execution
 962 * as part of the error recovery process.  If @sense_bytes is 0 the command
 963 * sent must be one that does not transfer any data.  If @sense_bytes != 0
 964 * @cmnd is ignored and this functions sets up a REQUEST_SENSE command
 965 * and cmnd buffers to read @sense_bytes into @scmd->sense_buffer.
 966 */
 967void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd, struct scsi_eh_save *ses,
 968                        unsigned char *cmnd, int cmnd_size, unsigned sense_bytes)
 969{
 970        struct scsi_device *sdev = scmd->device;
 971
 972        /*
 973         * We need saved copies of a number of fields - this is because
 974         * error handling may need to overwrite these with different values
 975         * to run different commands, and once error handling is complete,
 976         * we will need to restore these values prior to running the actual
 977         * command.
 978         */
 979        ses->cmd_len = scmd->cmd_len;
 980        ses->cmnd = scmd->cmnd;
 981        ses->data_direction = scmd->sc_data_direction;
 982        ses->sdb = scmd->sdb;
 983        ses->result = scmd->result;
 984        ses->resid_len = scmd->req.resid_len;
 985        ses->underflow = scmd->underflow;
 986        ses->prot_op = scmd->prot_op;
 987        ses->eh_eflags = scmd->eh_eflags;
 988
 989        scmd->prot_op = SCSI_PROT_NORMAL;
 990        scmd->eh_eflags = 0;
 991        scmd->cmnd = ses->eh_cmnd;
 992        memset(scmd->cmnd, 0, BLK_MAX_CDB);
 993        memset(&scmd->sdb, 0, sizeof(scmd->sdb));
 994        scmd->result = 0;
 995        scmd->req.resid_len = 0;
 996
 997        if (sense_bytes) {
 998                scmd->sdb.length = min_t(unsigned, SCSI_SENSE_BUFFERSIZE,
 999                                         sense_bytes);
1000                sg_init_one(&ses->sense_sgl, scmd->sense_buffer,
1001                            scmd->sdb.length);
1002                scmd->sdb.table.sgl = &ses->sense_sgl;
1003                scmd->sc_data_direction = DMA_FROM_DEVICE;
1004                scmd->sdb.table.nents = scmd->sdb.table.orig_nents = 1;
1005                scmd->cmnd[0] = REQUEST_SENSE;
1006                scmd->cmnd[4] = scmd->sdb.length;
1007                scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
1008        } else {
1009                scmd->sc_data_direction = DMA_NONE;
1010                if (cmnd) {
1011                        BUG_ON(cmnd_size > BLK_MAX_CDB);
1012                        memcpy(scmd->cmnd, cmnd, cmnd_size);
1013                        scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
1014                }
1015        }
1016
1017        scmd->underflow = 0;
1018
1019        if (sdev->scsi_level <= SCSI_2 && sdev->scsi_level != SCSI_UNKNOWN)
1020                scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) |
1021                        (sdev->lun << 5 & 0xe0);
1022
1023        /*
1024         * Zero the sense buffer.  The scsi spec mandates that any
1025         * untransferred sense data should be interpreted as being zero.
1026         */
1027        memset(scmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
1028}
1029EXPORT_SYMBOL(scsi_eh_prep_cmnd);
1030
1031/**
1032 * scsi_eh_restore_cmnd  - Restore a scsi command info as part of error recovery
1033 * @scmd:       SCSI command structure to restore
1034 * @ses:        saved information from a coresponding call to scsi_eh_prep_cmnd
1035 *
1036 * Undo any damage done by above scsi_eh_prep_cmnd().
1037 */
1038void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd, struct scsi_eh_save *ses)
1039{
1040        /*
1041         * Restore original data
1042         */
1043        scmd->cmd_len = ses->cmd_len;
1044        scmd->cmnd = ses->cmnd;
1045        scmd->sc_data_direction = ses->data_direction;
1046        scmd->sdb = ses->sdb;
1047        scmd->result = ses->result;
1048        scmd->req.resid_len = ses->resid_len;
1049        scmd->underflow = ses->underflow;
1050        scmd->prot_op = ses->prot_op;
1051        scmd->eh_eflags = ses->eh_eflags;
1052}
1053EXPORT_SYMBOL(scsi_eh_restore_cmnd);
1054
1055/**
1056 * scsi_send_eh_cmnd  - submit a scsi command as part of error recovery
1057 * @scmd:       SCSI command structure to hijack
1058 * @cmnd:       CDB to send
1059 * @cmnd_size:  size in bytes of @cmnd
1060 * @timeout:    timeout for this request
1061 * @sense_bytes: size of sense data to copy or 0
1062 *
1063 * This function is used to send a scsi command down to a target device
1064 * as part of the error recovery process. See also scsi_eh_prep_cmnd() above.
1065 *
1066 * Return value:
1067 *    SUCCESS or FAILED or NEEDS_RETRY
1068 */
1069static enum scsi_disposition scsi_send_eh_cmnd(struct scsi_cmnd *scmd,
1070        unsigned char *cmnd, int cmnd_size, int timeout, unsigned sense_bytes)
1071{
1072        struct scsi_device *sdev = scmd->device;
1073        struct Scsi_Host *shost = sdev->host;
1074        DECLARE_COMPLETION_ONSTACK(done);
1075        unsigned long timeleft = timeout, delay;
1076        struct scsi_eh_save ses;
1077        const unsigned long stall_for = msecs_to_jiffies(100);
1078        int rtn;
1079
1080retry:
1081        scsi_eh_prep_cmnd(scmd, &ses, cmnd, cmnd_size, sense_bytes);
1082        shost->eh_action = &done;
1083
1084        scsi_log_send(scmd);
1085        scmd->scsi_done = scsi_eh_done;
1086
1087        /*
1088         * Lock sdev->state_mutex to avoid that scsi_device_quiesce() can
1089         * change the SCSI device state after we have examined it and before
1090         * .queuecommand() is called.
1091         */
1092        mutex_lock(&sdev->state_mutex);
1093        while (sdev->sdev_state == SDEV_BLOCK && timeleft > 0) {
1094                mutex_unlock(&sdev->state_mutex);
1095                SCSI_LOG_ERROR_RECOVERY(5, sdev_printk(KERN_DEBUG, sdev,
1096                        "%s: state %d <> %d\n", __func__, sdev->sdev_state,
1097                        SDEV_BLOCK));
1098                delay = min(timeleft, stall_for);
1099                timeleft -= delay;
1100                msleep(jiffies_to_msecs(delay));
1101                mutex_lock(&sdev->state_mutex);
1102        }
1103        if (sdev->sdev_state != SDEV_BLOCK)
1104                rtn = shost->hostt->queuecommand(shost, scmd);
1105        else
1106                rtn = FAILED;
1107        mutex_unlock(&sdev->state_mutex);
1108
1109        if (rtn) {
1110                if (timeleft > stall_for) {
1111                        scsi_eh_restore_cmnd(scmd, &ses);
1112                        timeleft -= stall_for;
1113                        msleep(jiffies_to_msecs(stall_for));
1114                        goto retry;
1115                }
1116                /* signal not to enter either branch of the if () below */
1117                timeleft = 0;
1118                rtn = FAILED;
1119        } else {
1120                timeleft = wait_for_completion_timeout(&done, timeout);
1121                rtn = SUCCESS;
1122        }
1123
1124        shost->eh_action = NULL;
1125
1126        scsi_log_completion(scmd, rtn);
1127
1128        SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1129                        "%s timeleft: %ld\n",
1130                        __func__, timeleft));
1131
1132        /*
1133         * If there is time left scsi_eh_done got called, and we will examine
1134         * the actual status codes to see whether the command actually did
1135         * complete normally, else if we have a zero return and no time left,
1136         * the command must still be pending, so abort it and return FAILED.
1137         * If we never actually managed to issue the command, because
1138         * ->queuecommand() kept returning non zero, use the rtn = FAILED
1139         * value above (so don't execute either branch of the if)
1140         */
1141        if (timeleft) {
1142                rtn = scsi_eh_completed_normally(scmd);
1143                SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1144                        "%s: scsi_eh_completed_normally %x\n", __func__, rtn));
1145
1146                switch (rtn) {
1147                case SUCCESS:
1148                case NEEDS_RETRY:
1149                case FAILED:
1150                        break;
1151                case ADD_TO_MLQUEUE:
1152                        rtn = NEEDS_RETRY;
1153                        break;
1154                default:
1155                        rtn = FAILED;
1156                        break;
1157                }
1158        } else if (rtn != FAILED) {
1159                scsi_abort_eh_cmnd(scmd);
1160                rtn = FAILED;
1161        }
1162
1163        scsi_eh_restore_cmnd(scmd, &ses);
1164
1165        return rtn;
1166}
1167
1168/**
1169 * scsi_request_sense - Request sense data from a particular target.
1170 * @scmd:       SCSI cmd for request sense.
1171 *
1172 * Notes:
1173 *    Some hosts automatically obtain this information, others require
1174 *    that we obtain it on our own. This function will *not* return until
1175 *    the command either times out, or it completes.
1176 */
1177static enum scsi_disposition scsi_request_sense(struct scsi_cmnd *scmd)
1178{
1179        return scsi_send_eh_cmnd(scmd, NULL, 0, scmd->device->eh_timeout, ~0);
1180}
1181
1182static enum scsi_disposition
1183scsi_eh_action(struct scsi_cmnd *scmd, enum scsi_disposition rtn)
1184{
1185        if (!blk_rq_is_passthrough(scmd->request)) {
1186                struct scsi_driver *sdrv = scsi_cmd_to_driver(scmd);
1187                if (sdrv->eh_action)
1188                        rtn = sdrv->eh_action(scmd, rtn);
1189        }
1190        return rtn;
1191}
1192
1193/**
1194 * scsi_eh_finish_cmd - Handle a cmd that eh is finished with.
1195 * @scmd:       Original SCSI cmd that eh has finished.
1196 * @done_q:     Queue for processed commands.
1197 *
1198 * Notes:
1199 *    We don't want to use the normal command completion while we are are
1200 *    still handling errors - it may cause other commands to be queued,
1201 *    and that would disturb what we are doing.  Thus we really want to
1202 *    keep a list of pending commands for final completion, and once we
1203 *    are ready to leave error handling we handle completion for real.
1204 */
1205void scsi_eh_finish_cmd(struct scsi_cmnd *scmd, struct list_head *done_q)
1206{
1207        list_move_tail(&scmd->eh_entry, done_q);
1208}
1209EXPORT_SYMBOL(scsi_eh_finish_cmd);
1210
1211/**
1212 * scsi_eh_get_sense - Get device sense data.
1213 * @work_q:     Queue of commands to process.
1214 * @done_q:     Queue of processed commands.
1215 *
1216 * Description:
1217 *    See if we need to request sense information.  if so, then get it
1218 *    now, so we have a better idea of what to do.
1219 *
1220 * Notes:
1221 *    This has the unfortunate side effect that if a shost adapter does
1222 *    not automatically request sense information, we end up shutting
1223 *    it down before we request it.
1224 *
1225 *    All drivers should request sense information internally these days,
1226 *    so for now all I have to say is tough noogies if you end up in here.
1227 *
1228 *    XXX: Long term this code should go away, but that needs an audit of
1229 *         all LLDDs first.
1230 */
1231int scsi_eh_get_sense(struct list_head *work_q,
1232                      struct list_head *done_q)
1233{
1234        struct scsi_cmnd *scmd, *next;
1235        struct Scsi_Host *shost;
1236        enum scsi_disposition rtn;
1237
1238        /*
1239         * If SCSI_EH_ABORT_SCHEDULED has been set, it is timeout IO,
1240         * should not get sense.
1241         */
1242        list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1243                if ((scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) ||
1244                    SCSI_SENSE_VALID(scmd))
1245                        continue;
1246
1247                shost = scmd->device->host;
1248                if (scsi_host_eh_past_deadline(shost)) {
1249                        SCSI_LOG_ERROR_RECOVERY(3,
1250                                scmd_printk(KERN_INFO, scmd,
1251                                            "%s: skip request sense, past eh deadline\n",
1252                                             current->comm));
1253                        break;
1254                }
1255                if (!scsi_status_is_check_condition(scmd->result))
1256                        /*
1257                         * don't request sense if there's no check condition
1258                         * status because the error we're processing isn't one
1259                         * that has a sense code (and some devices get
1260                         * confused by sense requests out of the blue)
1261                         */
1262                        continue;
1263
1264                SCSI_LOG_ERROR_RECOVERY(2, scmd_printk(KERN_INFO, scmd,
1265                                                  "%s: requesting sense\n",
1266                                                  current->comm));
1267                rtn = scsi_request_sense(scmd);
1268                if (rtn != SUCCESS)
1269                        continue;
1270
1271                SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1272                        "sense requested, result %x\n", scmd->result));
1273                SCSI_LOG_ERROR_RECOVERY(3, scsi_print_sense(scmd));
1274
1275                rtn = scsi_decide_disposition(scmd);
1276
1277                /*
1278                 * if the result was normal, then just pass it along to the
1279                 * upper level.
1280                 */
1281                if (rtn == SUCCESS)
1282                        /*
1283                         * We don't want this command reissued, just finished
1284                         * with the sense data, so set retries to the max
1285                         * allowed to ensure it won't get reissued. If the user
1286                         * has requested infinite retries, we also want to
1287                         * finish this command, so force completion by setting
1288                         * retries and allowed to the same value.
1289                         */
1290                        if (scmd->allowed == SCSI_CMD_RETRIES_NO_LIMIT)
1291                                scmd->retries = scmd->allowed = 1;
1292                        else
1293                                scmd->retries = scmd->allowed;
1294                else if (rtn != NEEDS_RETRY)
1295                        continue;
1296
1297                scsi_eh_finish_cmd(scmd, done_q);
1298        }
1299
1300        return list_empty(work_q);
1301}
1302EXPORT_SYMBOL_GPL(scsi_eh_get_sense);
1303
1304/**
1305 * scsi_eh_tur - Send TUR to device.
1306 * @scmd:       &scsi_cmnd to send TUR
1307 *
1308 * Return value:
1309 *    0 - Device is ready. 1 - Device NOT ready.
1310 */
1311static int scsi_eh_tur(struct scsi_cmnd *scmd)
1312{
1313        static unsigned char tur_command[6] = {TEST_UNIT_READY, 0, 0, 0, 0, 0};
1314        int retry_cnt = 1;
1315        enum scsi_disposition rtn;
1316
1317retry_tur:
1318        rtn = scsi_send_eh_cmnd(scmd, tur_command, 6,
1319                                scmd->device->eh_timeout, 0);
1320
1321        SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1322                "%s return: %x\n", __func__, rtn));
1323
1324        switch (rtn) {
1325        case NEEDS_RETRY:
1326                if (retry_cnt--)
1327                        goto retry_tur;
1328                fallthrough;
1329        case SUCCESS:
1330                return 0;
1331        default:
1332                return 1;
1333        }
1334}
1335
1336/**
1337 * scsi_eh_test_devices - check if devices are responding from error recovery.
1338 * @cmd_list:   scsi commands in error recovery.
1339 * @work_q:     queue for commands which still need more error recovery
1340 * @done_q:     queue for commands which are finished
1341 * @try_stu:    boolean on if a STU command should be tried in addition to TUR.
1342 *
1343 * Decription:
1344 *    Tests if devices are in a working state.  Commands to devices now in
1345 *    a working state are sent to the done_q while commands to devices which
1346 *    are still failing to respond are returned to the work_q for more
1347 *    processing.
1348 **/
1349static int scsi_eh_test_devices(struct list_head *cmd_list,
1350                                struct list_head *work_q,
1351                                struct list_head *done_q, int try_stu)
1352{
1353        struct scsi_cmnd *scmd, *next;
1354        struct scsi_device *sdev;
1355        int finish_cmds;
1356
1357        while (!list_empty(cmd_list)) {
1358                scmd = list_entry(cmd_list->next, struct scsi_cmnd, eh_entry);
1359                sdev = scmd->device;
1360
1361                if (!try_stu) {
1362                        if (scsi_host_eh_past_deadline(sdev->host)) {
1363                                /* Push items back onto work_q */
1364                                list_splice_init(cmd_list, work_q);
1365                                SCSI_LOG_ERROR_RECOVERY(3,
1366                                        sdev_printk(KERN_INFO, sdev,
1367                                                    "%s: skip test device, past eh deadline",
1368                                                    current->comm));
1369                                break;
1370                        }
1371                }
1372
1373                finish_cmds = !scsi_device_online(scmd->device) ||
1374                        (try_stu && !scsi_eh_try_stu(scmd) &&
1375                         !scsi_eh_tur(scmd)) ||
1376                        !scsi_eh_tur(scmd);
1377
1378                list_for_each_entry_safe(scmd, next, cmd_list, eh_entry)
1379                        if (scmd->device == sdev) {
1380                                if (finish_cmds &&
1381                                    (try_stu ||
1382                                     scsi_eh_action(scmd, SUCCESS) == SUCCESS))
1383                                        scsi_eh_finish_cmd(scmd, done_q);
1384                                else
1385                                        list_move_tail(&scmd->eh_entry, work_q);
1386                        }
1387        }
1388        return list_empty(work_q);
1389}
1390
1391/**
1392 * scsi_eh_try_stu - Send START_UNIT to device.
1393 * @scmd:       &scsi_cmnd to send START_UNIT
1394 *
1395 * Return value:
1396 *    0 - Device is ready. 1 - Device NOT ready.
1397 */
1398static int scsi_eh_try_stu(struct scsi_cmnd *scmd)
1399{
1400        static unsigned char stu_command[6] = {START_STOP, 0, 0, 0, 1, 0};
1401
1402        if (scmd->device->allow_restart) {
1403                int i;
1404                enum scsi_disposition rtn = NEEDS_RETRY;
1405
1406                for (i = 0; rtn == NEEDS_RETRY && i < 2; i++)
1407                        rtn = scsi_send_eh_cmnd(scmd, stu_command, 6, scmd->device->request_queue->rq_timeout, 0);
1408
1409                if (rtn == SUCCESS)
1410                        return 0;
1411        }
1412
1413        return 1;
1414}
1415
1416 /**
1417 * scsi_eh_stu - send START_UNIT if needed
1418 * @shost:      &scsi host being recovered.
1419 * @work_q:     &list_head for pending commands.
1420 * @done_q:     &list_head for processed commands.
1421 *
1422 * Notes:
1423 *    If commands are failing due to not ready, initializing command required,
1424 *      try revalidating the device, which will end up sending a start unit.
1425 */
1426static int scsi_eh_stu(struct Scsi_Host *shost,
1427                              struct list_head *work_q,
1428                              struct list_head *done_q)
1429{
1430        struct scsi_cmnd *scmd, *stu_scmd, *next;
1431        struct scsi_device *sdev;
1432
1433        shost_for_each_device(sdev, shost) {
1434                if (scsi_host_eh_past_deadline(shost)) {
1435                        SCSI_LOG_ERROR_RECOVERY(3,
1436                                sdev_printk(KERN_INFO, sdev,
1437                                            "%s: skip START_UNIT, past eh deadline\n",
1438                                            current->comm));
1439                        scsi_device_put(sdev);
1440                        break;
1441                }
1442                stu_scmd = NULL;
1443                list_for_each_entry(scmd, work_q, eh_entry)
1444                        if (scmd->device == sdev && SCSI_SENSE_VALID(scmd) &&
1445                            scsi_check_sense(scmd) == FAILED ) {
1446                                stu_scmd = scmd;
1447                                break;
1448                        }
1449
1450                if (!stu_scmd)
1451                        continue;
1452
1453                SCSI_LOG_ERROR_RECOVERY(3,
1454                        sdev_printk(KERN_INFO, sdev,
1455                                     "%s: Sending START_UNIT\n",
1456                                    current->comm));
1457
1458                if (!scsi_eh_try_stu(stu_scmd)) {
1459                        if (!scsi_device_online(sdev) ||
1460                            !scsi_eh_tur(stu_scmd)) {
1461                                list_for_each_entry_safe(scmd, next,
1462                                                          work_q, eh_entry) {
1463                                        if (scmd->device == sdev &&
1464                                            scsi_eh_action(scmd, SUCCESS) == SUCCESS)
1465                                                scsi_eh_finish_cmd(scmd, done_q);
1466                                }
1467                        }
1468                } else {
1469                        SCSI_LOG_ERROR_RECOVERY(3,
1470                                sdev_printk(KERN_INFO, sdev,
1471                                            "%s: START_UNIT failed\n",
1472                                            current->comm));
1473                }
1474        }
1475
1476        return list_empty(work_q);
1477}
1478
1479
1480/**
1481 * scsi_eh_bus_device_reset - send bdr if needed
1482 * @shost:      scsi host being recovered.
1483 * @work_q:     &list_head for pending commands.
1484 * @done_q:     &list_head for processed commands.
1485 *
1486 * Notes:
1487 *    Try a bus device reset.  Still, look to see whether we have multiple
1488 *    devices that are jammed or not - if we have multiple devices, it
1489 *    makes no sense to try bus_device_reset - we really would need to try
1490 *    a bus_reset instead.
1491 */
1492static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
1493                                    struct list_head *work_q,
1494                                    struct list_head *done_q)
1495{
1496        struct scsi_cmnd *scmd, *bdr_scmd, *next;
1497        struct scsi_device *sdev;
1498        enum scsi_disposition rtn;
1499
1500        shost_for_each_device(sdev, shost) {
1501                if (scsi_host_eh_past_deadline(shost)) {
1502                        SCSI_LOG_ERROR_RECOVERY(3,
1503                                sdev_printk(KERN_INFO, sdev,
1504                                            "%s: skip BDR, past eh deadline\n",
1505                                             current->comm));
1506                        scsi_device_put(sdev);
1507                        break;
1508                }
1509                bdr_scmd = NULL;
1510                list_for_each_entry(scmd, work_q, eh_entry)
1511                        if (scmd->device == sdev) {
1512                                bdr_scmd = scmd;
1513                                break;
1514                        }
1515
1516                if (!bdr_scmd)
1517                        continue;
1518
1519                SCSI_LOG_ERROR_RECOVERY(3,
1520                        sdev_printk(KERN_INFO, sdev,
1521                                     "%s: Sending BDR\n", current->comm));
1522                rtn = scsi_try_bus_device_reset(bdr_scmd);
1523                if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
1524                        if (!scsi_device_online(sdev) ||
1525                            rtn == FAST_IO_FAIL ||
1526                            !scsi_eh_tur(bdr_scmd)) {
1527                                list_for_each_entry_safe(scmd, next,
1528                                                         work_q, eh_entry) {
1529                                        if (scmd->device == sdev &&
1530                                            scsi_eh_action(scmd, rtn) != FAILED)
1531                                                scsi_eh_finish_cmd(scmd,
1532                                                                   done_q);
1533                                }
1534                        }
1535                } else {
1536                        SCSI_LOG_ERROR_RECOVERY(3,
1537                                sdev_printk(KERN_INFO, sdev,
1538                                            "%s: BDR failed\n", current->comm));
1539                }
1540        }
1541
1542        return list_empty(work_q);
1543}
1544
1545/**
1546 * scsi_eh_target_reset - send target reset if needed
1547 * @shost:      scsi host being recovered.
1548 * @work_q:     &list_head for pending commands.
1549 * @done_q:     &list_head for processed commands.
1550 *
1551 * Notes:
1552 *    Try a target reset.
1553 */
1554static int scsi_eh_target_reset(struct Scsi_Host *shost,
1555                                struct list_head *work_q,
1556                                struct list_head *done_q)
1557{
1558        LIST_HEAD(tmp_list);
1559        LIST_HEAD(check_list);
1560
1561        list_splice_init(work_q, &tmp_list);
1562
1563        while (!list_empty(&tmp_list)) {
1564                struct scsi_cmnd *next, *scmd;
1565                enum scsi_disposition rtn;
1566                unsigned int id;
1567
1568                if (scsi_host_eh_past_deadline(shost)) {
1569                        /* push back on work queue for further processing */
1570                        list_splice_init(&check_list, work_q);
1571                        list_splice_init(&tmp_list, work_q);
1572                        SCSI_LOG_ERROR_RECOVERY(3,
1573                                shost_printk(KERN_INFO, shost,
1574                                            "%s: Skip target reset, past eh deadline\n",
1575                                             current->comm));
1576                        return list_empty(work_q);
1577                }
1578
1579                scmd = list_entry(tmp_list.next, struct scsi_cmnd, eh_entry);
1580                id = scmd_id(scmd);
1581
1582                SCSI_LOG_ERROR_RECOVERY(3,
1583                        shost_printk(KERN_INFO, shost,
1584                                     "%s: Sending target reset to target %d\n",
1585                                     current->comm, id));
1586                rtn = scsi_try_target_reset(scmd);
1587                if (rtn != SUCCESS && rtn != FAST_IO_FAIL)
1588                        SCSI_LOG_ERROR_RECOVERY(3,
1589                                shost_printk(KERN_INFO, shost,
1590                                             "%s: Target reset failed"
1591                                             " target: %d\n",
1592                                             current->comm, id));
1593                list_for_each_entry_safe(scmd, next, &tmp_list, eh_entry) {
1594                        if (scmd_id(scmd) != id)
1595                                continue;
1596
1597                        if (rtn == SUCCESS)
1598                                list_move_tail(&scmd->eh_entry, &check_list);
1599                        else if (rtn == FAST_IO_FAIL)
1600                                scsi_eh_finish_cmd(scmd, done_q);
1601                        else
1602                                /* push back on work queue for further processing */
1603                                list_move(&scmd->eh_entry, work_q);
1604                }
1605        }
1606
1607        return scsi_eh_test_devices(&check_list, work_q, done_q, 0);
1608}
1609
1610/**
1611 * scsi_eh_bus_reset - send a bus reset
1612 * @shost:      &scsi host being recovered.
1613 * @work_q:     &list_head for pending commands.
1614 * @done_q:     &list_head for processed commands.
1615 */
1616static int scsi_eh_bus_reset(struct Scsi_Host *shost,
1617                             struct list_head *work_q,
1618                             struct list_head *done_q)
1619{
1620        struct scsi_cmnd *scmd, *chan_scmd, *next;
1621        LIST_HEAD(check_list);
1622        unsigned int channel;
1623        enum scsi_disposition rtn;
1624
1625        /*
1626         * we really want to loop over the various channels, and do this on
1627         * a channel by channel basis.  we should also check to see if any
1628         * of the failed commands are on soft_reset devices, and if so, skip
1629         * the reset.
1630         */
1631
1632        for (channel = 0; channel <= shost->max_channel; channel++) {
1633                if (scsi_host_eh_past_deadline(shost)) {
1634                        list_splice_init(&check_list, work_q);
1635                        SCSI_LOG_ERROR_RECOVERY(3,
1636                                shost_printk(KERN_INFO, shost,
1637                                            "%s: skip BRST, past eh deadline\n",
1638                                             current->comm));
1639                        return list_empty(work_q);
1640                }
1641
1642                chan_scmd = NULL;
1643                list_for_each_entry(scmd, work_q, eh_entry) {
1644                        if (channel == scmd_channel(scmd)) {
1645                                chan_scmd = scmd;
1646                                break;
1647                                /*
1648                                 * FIXME add back in some support for
1649                                 * soft_reset devices.
1650                                 */
1651                        }
1652                }
1653
1654                if (!chan_scmd)
1655                        continue;
1656                SCSI_LOG_ERROR_RECOVERY(3,
1657                        shost_printk(KERN_INFO, shost,
1658                                     "%s: Sending BRST chan: %d\n",
1659                                     current->comm, channel));
1660                rtn = scsi_try_bus_reset(chan_scmd);
1661                if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
1662                        list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1663                                if (channel == scmd_channel(scmd)) {
1664                                        if (rtn == FAST_IO_FAIL)
1665                                                scsi_eh_finish_cmd(scmd,
1666                                                                   done_q);
1667                                        else
1668                                                list_move_tail(&scmd->eh_entry,
1669                                                               &check_list);
1670                                }
1671                        }
1672                } else {
1673                        SCSI_LOG_ERROR_RECOVERY(3,
1674                                shost_printk(KERN_INFO, shost,
1675                                             "%s: BRST failed chan: %d\n",
1676                                             current->comm, channel));
1677                }
1678        }
1679        return scsi_eh_test_devices(&check_list, work_q, done_q, 0);
1680}
1681
1682/**
1683 * scsi_eh_host_reset - send a host reset
1684 * @shost:      host to be reset.
1685 * @work_q:     &list_head for pending commands.
1686 * @done_q:     &list_head for processed commands.
1687 */
1688static int scsi_eh_host_reset(struct Scsi_Host *shost,
1689                              struct list_head *work_q,
1690                              struct list_head *done_q)
1691{
1692        struct scsi_cmnd *scmd, *next;
1693        LIST_HEAD(check_list);
1694        enum scsi_disposition rtn;
1695
1696        if (!list_empty(work_q)) {
1697                scmd = list_entry(work_q->next,
1698                                  struct scsi_cmnd, eh_entry);
1699
1700                SCSI_LOG_ERROR_RECOVERY(3,
1701                        shost_printk(KERN_INFO, shost,
1702                                     "%s: Sending HRST\n",
1703                                     current->comm));
1704
1705                rtn = scsi_try_host_reset(scmd);
1706                if (rtn == SUCCESS) {
1707                        list_splice_init(work_q, &check_list);
1708                } else if (rtn == FAST_IO_FAIL) {
1709                        list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1710                                        scsi_eh_finish_cmd(scmd, done_q);
1711                        }
1712                } else {
1713                        SCSI_LOG_ERROR_RECOVERY(3,
1714                                shost_printk(KERN_INFO, shost,
1715                                             "%s: HRST failed\n",
1716                                             current->comm));
1717                }
1718        }
1719        return scsi_eh_test_devices(&check_list, work_q, done_q, 1);
1720}
1721
1722/**
1723 * scsi_eh_offline_sdevs - offline scsi devices that fail to recover
1724 * @work_q:     &list_head for pending commands.
1725 * @done_q:     &list_head for processed commands.
1726 */
1727static void scsi_eh_offline_sdevs(struct list_head *work_q,
1728                                  struct list_head *done_q)
1729{
1730        struct scsi_cmnd *scmd, *next;
1731        struct scsi_device *sdev;
1732
1733        list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1734                sdev_printk(KERN_INFO, scmd->device, "Device offlined - "
1735                            "not ready after error recovery\n");
1736                sdev = scmd->device;
1737
1738                mutex_lock(&sdev->state_mutex);
1739                scsi_device_set_state(sdev, SDEV_OFFLINE);
1740                mutex_unlock(&sdev->state_mutex);
1741
1742                scsi_eh_finish_cmd(scmd, done_q);
1743        }
1744        return;
1745}
1746
1747/**
1748 * scsi_noretry_cmd - determine if command should be failed fast
1749 * @scmd:       SCSI cmd to examine.
1750 */
1751int scsi_noretry_cmd(struct scsi_cmnd *scmd)
1752{
1753        switch (host_byte(scmd->result)) {
1754        case DID_OK:
1755                break;
1756        case DID_TIME_OUT:
1757                goto check_type;
1758        case DID_BUS_BUSY:
1759                return (scmd->request->cmd_flags & REQ_FAILFAST_TRANSPORT);
1760        case DID_PARITY:
1761                return (scmd->request->cmd_flags & REQ_FAILFAST_DEV);
1762        case DID_ERROR:
1763                if (get_status_byte(scmd) == SAM_STAT_RESERVATION_CONFLICT)
1764                        return 0;
1765                fallthrough;
1766        case DID_SOFT_ERROR:
1767                return (scmd->request->cmd_flags & REQ_FAILFAST_DRIVER);
1768        }
1769
1770        if (!scsi_status_is_check_condition(scmd->result))
1771                return 0;
1772
1773check_type:
1774        /*
1775         * assume caller has checked sense and determined
1776         * the check condition was retryable.
1777         */
1778        if (scmd->request->cmd_flags & REQ_FAILFAST_DEV ||
1779            blk_rq_is_passthrough(scmd->request))
1780                return 1;
1781
1782        return 0;
1783}
1784
1785/**
1786 * scsi_decide_disposition - Disposition a cmd on return from LLD.
1787 * @scmd:       SCSI cmd to examine.
1788 *
1789 * Notes:
1790 *    This is *only* called when we are examining the status after sending
1791 *    out the actual data command.  any commands that are queued for error
1792 *    recovery (e.g. test_unit_ready) do *not* come through here.
1793 *
1794 *    When this routine returns failed, it means the error handler thread
1795 *    is woken.  In cases where the error code indicates an error that
1796 *    doesn't require the error handler read (i.e. we don't need to
1797 *    abort/reset), this function should return SUCCESS.
1798 */
1799enum scsi_disposition scsi_decide_disposition(struct scsi_cmnd *scmd)
1800{
1801        enum scsi_disposition rtn;
1802
1803        /*
1804         * if the device is offline, then we clearly just pass the result back
1805         * up to the top level.
1806         */
1807        if (!scsi_device_online(scmd->device)) {
1808                SCSI_LOG_ERROR_RECOVERY(5, scmd_printk(KERN_INFO, scmd,
1809                        "%s: device offline - report as SUCCESS\n", __func__));
1810                return SUCCESS;
1811        }
1812
1813        /*
1814         * first check the host byte, to see if there is anything in there
1815         * that would indicate what we need to do.
1816         */
1817        switch (host_byte(scmd->result)) {
1818        case DID_PASSTHROUGH:
1819                /*
1820                 * no matter what, pass this through to the upper layer.
1821                 * nuke this special code so that it looks like we are saying
1822                 * did_ok.
1823                 */
1824                scmd->result &= 0xff00ffff;
1825                return SUCCESS;
1826        case DID_OK:
1827                /*
1828                 * looks good.  drop through, and check the next byte.
1829                 */
1830                break;
1831        case DID_ABORT:
1832                if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) {
1833                        set_host_byte(scmd, DID_TIME_OUT);
1834                        return SUCCESS;
1835                }
1836                fallthrough;
1837        case DID_NO_CONNECT:
1838        case DID_BAD_TARGET:
1839                /*
1840                 * note - this means that we just report the status back
1841                 * to the top level driver, not that we actually think
1842                 * that it indicates SUCCESS.
1843                 */
1844                return SUCCESS;
1845        case DID_SOFT_ERROR:
1846                /*
1847                 * when the low level driver returns did_soft_error,
1848                 * it is responsible for keeping an internal retry counter
1849                 * in order to avoid endless loops (db)
1850                 */
1851                goto maybe_retry;
1852        case DID_IMM_RETRY:
1853                return NEEDS_RETRY;
1854
1855        case DID_REQUEUE:
1856                return ADD_TO_MLQUEUE;
1857        case DID_TRANSPORT_DISRUPTED:
1858                /*
1859                 * LLD/transport was disrupted during processing of the IO.
1860                 * The transport class is now blocked/blocking,
1861                 * and the transport will decide what to do with the IO
1862                 * based on its timers and recovery capablilities if
1863                 * there are enough retries.
1864                 */
1865                goto maybe_retry;
1866        case DID_TRANSPORT_FAILFAST:
1867                /*
1868                 * The transport decided to failfast the IO (most likely
1869                 * the fast io fail tmo fired), so send IO directly upwards.
1870                 */
1871                return SUCCESS;
1872        case DID_TRANSPORT_MARGINAL:
1873                /*
1874                 * caller has decided not to do retries on
1875                 * abort success, so send IO directly upwards
1876                 */
1877                return SUCCESS;
1878        case DID_ERROR:
1879                if (get_status_byte(scmd) == SAM_STAT_RESERVATION_CONFLICT)
1880                        /*
1881                         * execute reservation conflict processing code
1882                         * lower down
1883                         */
1884                        break;
1885                fallthrough;
1886        case DID_BUS_BUSY:
1887        case DID_PARITY:
1888                goto maybe_retry;
1889        case DID_TIME_OUT:
1890                /*
1891                 * when we scan the bus, we get timeout messages for
1892                 * these commands if there is no device available.
1893                 * other hosts report did_no_connect for the same thing.
1894                 */
1895                if ((scmd->cmnd[0] == TEST_UNIT_READY ||
1896                     scmd->cmnd[0] == INQUIRY)) {
1897                        return SUCCESS;
1898                } else {
1899                        return FAILED;
1900                }
1901        case DID_RESET:
1902                return SUCCESS;
1903        default:
1904                return FAILED;
1905        }
1906
1907        /*
1908         * check the status byte to see if this indicates anything special.
1909         */
1910        switch (get_status_byte(scmd)) {
1911        case SAM_STAT_TASK_SET_FULL:
1912                scsi_handle_queue_full(scmd->device);
1913                /*
1914                 * the case of trying to send too many commands to a
1915                 * tagged queueing device.
1916                 */
1917                fallthrough;
1918        case SAM_STAT_BUSY:
1919                /*
1920                 * device can't talk to us at the moment.  Should only
1921                 * occur (SAM-3) when the task queue is empty, so will cause
1922                 * the empty queue handling to trigger a stall in the
1923                 * device.
1924                 */
1925                return ADD_TO_MLQUEUE;
1926        case SAM_STAT_GOOD:
1927                if (scmd->cmnd[0] == REPORT_LUNS)
1928                        scmd->device->sdev_target->expecting_lun_change = 0;
1929                scsi_handle_queue_ramp_up(scmd->device);
1930                fallthrough;
1931        case SAM_STAT_COMMAND_TERMINATED:
1932                return SUCCESS;
1933        case SAM_STAT_TASK_ABORTED:
1934                goto maybe_retry;
1935        case SAM_STAT_CHECK_CONDITION:
1936                rtn = scsi_check_sense(scmd);
1937                if (rtn == NEEDS_RETRY)
1938                        goto maybe_retry;
1939                /* if rtn == FAILED, we have no sense information;
1940                 * returning FAILED will wake the error handler thread
1941                 * to collect the sense and redo the decide
1942                 * disposition */
1943                return rtn;
1944        case SAM_STAT_CONDITION_MET:
1945        case SAM_STAT_INTERMEDIATE:
1946        case SAM_STAT_INTERMEDIATE_CONDITION_MET:
1947        case SAM_STAT_ACA_ACTIVE:
1948                /*
1949                 * who knows?  FIXME(eric)
1950                 */
1951                return SUCCESS;
1952
1953        case SAM_STAT_RESERVATION_CONFLICT:
1954                sdev_printk(KERN_INFO, scmd->device,
1955                            "reservation conflict\n");
1956                set_host_byte(scmd, DID_NEXUS_FAILURE);
1957                return SUCCESS; /* causes immediate i/o error */
1958        default:
1959                return FAILED;
1960        }
1961        return FAILED;
1962
1963maybe_retry:
1964
1965        /* we requeue for retry because the error was retryable, and
1966         * the request was not marked fast fail.  Note that above,
1967         * even if the request is marked fast fail, we still requeue
1968         * for queue congestion conditions (QUEUE_FULL or BUSY) */
1969        if (scsi_cmd_retry_allowed(scmd) && !scsi_noretry_cmd(scmd)) {
1970                return NEEDS_RETRY;
1971        } else {
1972                /*
1973                 * no more retries - report this one back to upper level.
1974                 */
1975                return SUCCESS;
1976        }
1977}
1978
1979static void eh_lock_door_done(struct request *req, blk_status_t status)
1980{
1981        blk_put_request(req);
1982}
1983
1984/**
1985 * scsi_eh_lock_door - Prevent medium removal for the specified device
1986 * @sdev:       SCSI device to prevent medium removal
1987 *
1988 * Locking:
1989 *      We must be called from process context.
1990 *
1991 * Notes:
1992 *      We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the
1993 *      head of the devices request queue, and continue.
1994 */
1995static void scsi_eh_lock_door(struct scsi_device *sdev)
1996{
1997        struct request *req;
1998        struct scsi_request *rq;
1999
2000        req = blk_get_request(sdev->request_queue, REQ_OP_DRV_IN, 0);
2001        if (IS_ERR(req))
2002                return;
2003        rq = scsi_req(req);
2004
2005        rq->cmd[0] = ALLOW_MEDIUM_REMOVAL;
2006        rq->cmd[1] = 0;
2007        rq->cmd[2] = 0;
2008        rq->cmd[3] = 0;
2009        rq->cmd[4] = SCSI_REMOVAL_PREVENT;
2010        rq->cmd[5] = 0;
2011        rq->cmd_len = COMMAND_SIZE(rq->cmd[0]);
2012
2013        req->rq_flags |= RQF_QUIET;
2014        req->timeout = 10 * HZ;
2015        rq->retries = 5;
2016
2017        blk_execute_rq_nowait(NULL, req, 1, eh_lock_door_done);
2018}
2019
2020/**
2021 * scsi_restart_operations - restart io operations to the specified host.
2022 * @shost:      Host we are restarting.
2023 *
2024 * Notes:
2025 *    When we entered the error handler, we blocked all further i/o to
2026 *    this device.  we need to 'reverse' this process.
2027 */
2028static void scsi_restart_operations(struct Scsi_Host *shost)
2029{
2030        struct scsi_device *sdev;
2031        unsigned long flags;
2032
2033        /*
2034         * If the door was locked, we need to insert a door lock request
2035         * onto the head of the SCSI request queue for the device.  There
2036         * is no point trying to lock the door of an off-line device.
2037         */
2038        shost_for_each_device(sdev, shost) {
2039                if (scsi_device_online(sdev) && sdev->was_reset && sdev->locked) {
2040                        scsi_eh_lock_door(sdev);
2041                        sdev->was_reset = 0;
2042                }
2043        }
2044
2045        /*
2046         * next free up anything directly waiting upon the host.  this
2047         * will be requests for character device operations, and also for
2048         * ioctls to queued block devices.
2049         */
2050        SCSI_LOG_ERROR_RECOVERY(3,
2051                shost_printk(KERN_INFO, shost, "waking up host to restart\n"));
2052
2053        spin_lock_irqsave(shost->host_lock, flags);
2054        if (scsi_host_set_state(shost, SHOST_RUNNING))
2055                if (scsi_host_set_state(shost, SHOST_CANCEL))
2056                        BUG_ON(scsi_host_set_state(shost, SHOST_DEL));
2057        spin_unlock_irqrestore(shost->host_lock, flags);
2058
2059        wake_up(&shost->host_wait);
2060
2061        /*
2062         * finally we need to re-initiate requests that may be pending.  we will
2063         * have had everything blocked while error handling is taking place, and
2064         * now that error recovery is done, we will need to ensure that these
2065         * requests are started.
2066         */
2067        scsi_run_host_queues(shost);
2068
2069        /*
2070         * if eh is active and host_eh_scheduled is pending we need to re-run
2071         * recovery.  we do this check after scsi_run_host_queues() to allow
2072         * everything pent up since the last eh run a chance to make forward
2073         * progress before we sync again.  Either we'll immediately re-run
2074         * recovery or scsi_device_unbusy() will wake us again when these
2075         * pending commands complete.
2076         */
2077        spin_lock_irqsave(shost->host_lock, flags);
2078        if (shost->host_eh_scheduled)
2079                if (scsi_host_set_state(shost, SHOST_RECOVERY))
2080                        WARN_ON(scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY));
2081        spin_unlock_irqrestore(shost->host_lock, flags);
2082}
2083
2084/**
2085 * scsi_eh_ready_devs - check device ready state and recover if not.
2086 * @shost:      host to be recovered.
2087 * @work_q:     &list_head for pending commands.
2088 * @done_q:     &list_head for processed commands.
2089 */
2090void scsi_eh_ready_devs(struct Scsi_Host *shost,
2091                        struct list_head *work_q,
2092                        struct list_head *done_q)
2093{
2094        if (!scsi_eh_stu(shost, work_q, done_q))
2095                if (!scsi_eh_bus_device_reset(shost, work_q, done_q))
2096                        if (!scsi_eh_target_reset(shost, work_q, done_q))
2097                                if (!scsi_eh_bus_reset(shost, work_q, done_q))
2098                                        if (!scsi_eh_host_reset(shost, work_q, done_q))
2099                                                scsi_eh_offline_sdevs(work_q,
2100                                                                      done_q);
2101}
2102EXPORT_SYMBOL_GPL(scsi_eh_ready_devs);
2103
2104/**
2105 * scsi_eh_flush_done_q - finish processed commands or retry them.
2106 * @done_q:     list_head of processed commands.
2107 */
2108void scsi_eh_flush_done_q(struct list_head *done_q)
2109{
2110        struct scsi_cmnd *scmd, *next;
2111
2112        list_for_each_entry_safe(scmd, next, done_q, eh_entry) {
2113                list_del_init(&scmd->eh_entry);
2114                if (scsi_device_online(scmd->device) &&
2115                    !scsi_noretry_cmd(scmd) && scsi_cmd_retry_allowed(scmd) &&
2116                        scsi_eh_should_retry_cmd(scmd)) {
2117                        SCSI_LOG_ERROR_RECOVERY(3,
2118                                scmd_printk(KERN_INFO, scmd,
2119                                             "%s: flush retry cmd\n",
2120                                             current->comm));
2121                                scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY);
2122                } else {
2123                        /*
2124                         * If just we got sense for the device (called
2125                         * scsi_eh_get_sense), scmd->result is already
2126                         * set, do not set DID_TIME_OUT.
2127                         */
2128                        if (!scmd->result)
2129                                scmd->result |= (DID_TIME_OUT << 16);
2130                        SCSI_LOG_ERROR_RECOVERY(3,
2131                                scmd_printk(KERN_INFO, scmd,
2132                                             "%s: flush finish cmd\n",
2133                                             current->comm));
2134                        scsi_finish_command(scmd);
2135                }
2136        }
2137}
2138EXPORT_SYMBOL(scsi_eh_flush_done_q);
2139
2140/**
2141 * scsi_unjam_host - Attempt to fix a host which has a cmd that failed.
2142 * @shost:      Host to unjam.
2143 *
2144 * Notes:
2145 *    When we come in here, we *know* that all commands on the bus have
2146 *    either completed, failed or timed out.  we also know that no further
2147 *    commands are being sent to the host, so things are relatively quiet
2148 *    and we have freedom to fiddle with things as we wish.
2149 *
2150 *    This is only the *default* implementation.  it is possible for
2151 *    individual drivers to supply their own version of this function, and
2152 *    if the maintainer wishes to do this, it is strongly suggested that
2153 *    this function be taken as a template and modified.  this function
2154 *    was designed to correctly handle problems for about 95% of the
2155 *    different cases out there, and it should always provide at least a
2156 *    reasonable amount of error recovery.
2157 *
2158 *    Any command marked 'failed' or 'timeout' must eventually have
2159 *    scsi_finish_cmd() called for it.  we do all of the retry stuff
2160 *    here, so when we restart the host after we return it should have an
2161 *    empty queue.
2162 */
2163static void scsi_unjam_host(struct Scsi_Host *shost)
2164{
2165        unsigned long flags;
2166        LIST_HEAD(eh_work_q);
2167        LIST_HEAD(eh_done_q);
2168
2169        spin_lock_irqsave(shost->host_lock, flags);
2170        list_splice_init(&shost->eh_cmd_q, &eh_work_q);
2171        spin_unlock_irqrestore(shost->host_lock, flags);
2172
2173        SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(shost, &eh_work_q));
2174
2175        if (!scsi_eh_get_sense(&eh_work_q, &eh_done_q))
2176                scsi_eh_ready_devs(shost, &eh_work_q, &eh_done_q);
2177
2178        spin_lock_irqsave(shost->host_lock, flags);
2179        if (shost->eh_deadline != -1)
2180                shost->last_reset = 0;
2181        spin_unlock_irqrestore(shost->host_lock, flags);
2182        scsi_eh_flush_done_q(&eh_done_q);
2183}
2184
2185/**
2186 * scsi_error_handler - SCSI error handler thread
2187 * @data:       Host for which we are running.
2188 *
2189 * Notes:
2190 *    This is the main error handling loop.  This is run as a kernel thread
2191 *    for every SCSI host and handles all error handling activity.
2192 */
2193int scsi_error_handler(void *data)
2194{
2195        struct Scsi_Host *shost = data;
2196
2197        /*
2198         * We use TASK_INTERRUPTIBLE so that the thread is not
2199         * counted against the load average as a running process.
2200         * We never actually get interrupted because kthread_run
2201         * disables signal delivery for the created thread.
2202         */
2203        while (true) {
2204                /*
2205                 * The sequence in kthread_stop() sets the stop flag first
2206                 * then wakes the process.  To avoid missed wakeups, the task
2207                 * should always be in a non running state before the stop
2208                 * flag is checked
2209                 */
2210                set_current_state(TASK_INTERRUPTIBLE);
2211                if (kthread_should_stop())
2212                        break;
2213
2214                if ((shost->host_failed == 0 && shost->host_eh_scheduled == 0) ||
2215                    shost->host_failed != scsi_host_busy(shost)) {
2216                        SCSI_LOG_ERROR_RECOVERY(1,
2217                                shost_printk(KERN_INFO, shost,
2218                                             "scsi_eh_%d: sleeping\n",
2219                                             shost->host_no));
2220                        schedule();
2221                        continue;
2222                }
2223
2224                __set_current_state(TASK_RUNNING);
2225                SCSI_LOG_ERROR_RECOVERY(1,
2226                        shost_printk(KERN_INFO, shost,
2227                                     "scsi_eh_%d: waking up %d/%d/%d\n",
2228                                     shost->host_no, shost->host_eh_scheduled,
2229                                     shost->host_failed,
2230                                     scsi_host_busy(shost)));
2231
2232                /*
2233                 * We have a host that is failing for some reason.  Figure out
2234                 * what we need to do to get it up and online again (if we can).
2235                 * If we fail, we end up taking the thing offline.
2236                 */
2237                if (!shost->eh_noresume && scsi_autopm_get_host(shost) != 0) {
2238                        SCSI_LOG_ERROR_RECOVERY(1,
2239                                shost_printk(KERN_ERR, shost,
2240                                             "scsi_eh_%d: unable to autoresume\n",
2241                                             shost->host_no));
2242                        continue;
2243                }
2244
2245                if (shost->transportt->eh_strategy_handler)
2246                        shost->transportt->eh_strategy_handler(shost);
2247                else
2248                        scsi_unjam_host(shost);
2249
2250                /* All scmds have been handled */
2251                shost->host_failed = 0;
2252
2253                /*
2254                 * Note - if the above fails completely, the action is to take
2255                 * individual devices offline and flush the queue of any
2256                 * outstanding requests that may have been pending.  When we
2257                 * restart, we restart any I/O to any other devices on the bus
2258                 * which are still online.
2259                 */
2260                scsi_restart_operations(shost);
2261                if (!shost->eh_noresume)
2262                        scsi_autopm_put_host(shost);
2263        }
2264        __set_current_state(TASK_RUNNING);
2265
2266        SCSI_LOG_ERROR_RECOVERY(1,
2267                shost_printk(KERN_INFO, shost,
2268                             "Error handler scsi_eh_%d exiting\n",
2269                             shost->host_no));
2270        shost->ehandler = NULL;
2271        return 0;
2272}
2273
2274/*
2275 * Function:    scsi_report_bus_reset()
2276 *
2277 * Purpose:     Utility function used by low-level drivers to report that
2278 *              they have observed a bus reset on the bus being handled.
2279 *
2280 * Arguments:   shost       - Host in question
2281 *              channel     - channel on which reset was observed.
2282 *
2283 * Returns:     Nothing
2284 *
2285 * Lock status: Host lock must be held.
2286 *
2287 * Notes:       This only needs to be called if the reset is one which
2288 *              originates from an unknown location.  Resets originated
2289 *              by the mid-level itself don't need to call this, but there
2290 *              should be no harm.
2291 *
2292 *              The main purpose of this is to make sure that a CHECK_CONDITION
2293 *              is properly treated.
2294 */
2295void scsi_report_bus_reset(struct Scsi_Host *shost, int channel)
2296{
2297        struct scsi_device *sdev;
2298
2299        __shost_for_each_device(sdev, shost) {
2300                if (channel == sdev_channel(sdev))
2301                        __scsi_report_device_reset(sdev, NULL);
2302        }
2303}
2304EXPORT_SYMBOL(scsi_report_bus_reset);
2305
2306/*
2307 * Function:    scsi_report_device_reset()
2308 *
2309 * Purpose:     Utility function used by low-level drivers to report that
2310 *              they have observed a device reset on the device being handled.
2311 *
2312 * Arguments:   shost       - Host in question
2313 *              channel     - channel on which reset was observed
2314 *              target      - target on which reset was observed
2315 *
2316 * Returns:     Nothing
2317 *
2318 * Lock status: Host lock must be held
2319 *
2320 * Notes:       This only needs to be called if the reset is one which
2321 *              originates from an unknown location.  Resets originated
2322 *              by the mid-level itself don't need to call this, but there
2323 *              should be no harm.
2324 *
2325 *              The main purpose of this is to make sure that a CHECK_CONDITION
2326 *              is properly treated.
2327 */
2328void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
2329{
2330        struct scsi_device *sdev;
2331
2332        __shost_for_each_device(sdev, shost) {
2333                if (channel == sdev_channel(sdev) &&
2334                    target == sdev_id(sdev))
2335                        __scsi_report_device_reset(sdev, NULL);
2336        }
2337}
2338EXPORT_SYMBOL(scsi_report_device_reset);
2339
2340static void
2341scsi_reset_provider_done_command(struct scsi_cmnd *scmd)
2342{
2343}
2344
2345/**
2346 * scsi_ioctl_reset: explicitly reset a host/bus/target/device
2347 * @dev:        scsi_device to operate on
2348 * @arg:        reset type (see sg.h)
2349 */
2350int
2351scsi_ioctl_reset(struct scsi_device *dev, int __user *arg)
2352{
2353        struct scsi_cmnd *scmd;
2354        struct Scsi_Host *shost = dev->host;
2355        struct request *rq;
2356        unsigned long flags;
2357        int error = 0, val;
2358        enum scsi_disposition rtn;
2359
2360        if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2361                return -EACCES;
2362
2363        error = get_user(val, arg);
2364        if (error)
2365                return error;
2366
2367        if (scsi_autopm_get_host(shost) < 0)
2368                return -EIO;
2369
2370        error = -EIO;
2371        rq = kzalloc(sizeof(struct request) + sizeof(struct scsi_cmnd) +
2372                        shost->hostt->cmd_size, GFP_KERNEL);
2373        if (!rq)
2374                goto out_put_autopm_host;
2375        blk_rq_init(NULL, rq);
2376
2377        scmd = (struct scsi_cmnd *)(rq + 1);
2378        scsi_init_command(dev, scmd);
2379        scmd->request = rq;
2380        scmd->cmnd = scsi_req(rq)->cmd;
2381
2382        scmd->scsi_done         = scsi_reset_provider_done_command;
2383        memset(&scmd->sdb, 0, sizeof(scmd->sdb));
2384
2385        scmd->cmd_len                   = 0;
2386
2387        scmd->sc_data_direction         = DMA_BIDIRECTIONAL;
2388
2389        spin_lock_irqsave(shost->host_lock, flags);
2390        shost->tmf_in_progress = 1;
2391        spin_unlock_irqrestore(shost->host_lock, flags);
2392
2393        switch (val & ~SG_SCSI_RESET_NO_ESCALATE) {
2394        case SG_SCSI_RESET_NOTHING:
2395                rtn = SUCCESS;
2396                break;
2397        case SG_SCSI_RESET_DEVICE:
2398                rtn = scsi_try_bus_device_reset(scmd);
2399                if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE))
2400                        break;
2401                fallthrough;
2402        case SG_SCSI_RESET_TARGET:
2403                rtn = scsi_try_target_reset(scmd);
2404                if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE))
2405                        break;
2406                fallthrough;
2407        case SG_SCSI_RESET_BUS:
2408                rtn = scsi_try_bus_reset(scmd);
2409                if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE))
2410                        break;
2411                fallthrough;
2412        case SG_SCSI_RESET_HOST:
2413                rtn = scsi_try_host_reset(scmd);
2414                if (rtn == SUCCESS)
2415                        break;
2416                fallthrough;
2417        default:
2418                rtn = FAILED;
2419                break;
2420        }
2421
2422        error = (rtn == SUCCESS) ? 0 : -EIO;
2423
2424        spin_lock_irqsave(shost->host_lock, flags);
2425        shost->tmf_in_progress = 0;
2426        spin_unlock_irqrestore(shost->host_lock, flags);
2427
2428        /*
2429         * be sure to wake up anyone who was sleeping or had their queue
2430         * suspended while we performed the TMF.
2431         */
2432        SCSI_LOG_ERROR_RECOVERY(3,
2433                shost_printk(KERN_INFO, shost,
2434                             "waking up host to restart after TMF\n"));
2435
2436        wake_up(&shost->host_wait);
2437        scsi_run_host_queues(shost);
2438
2439        kfree(rq);
2440
2441out_put_autopm_host:
2442        scsi_autopm_put_host(shost);
2443        return error;
2444}
2445
2446bool scsi_command_normalize_sense(const struct scsi_cmnd *cmd,
2447                                  struct scsi_sense_hdr *sshdr)
2448{
2449        return scsi_normalize_sense(cmd->sense_buffer,
2450                        SCSI_SENSE_BUFFERSIZE, sshdr);
2451}
2452EXPORT_SYMBOL(scsi_command_normalize_sense);
2453
2454/**
2455 * scsi_get_sense_info_fld - get information field from sense data (either fixed or descriptor format)
2456 * @sense_buffer:       byte array of sense data
2457 * @sb_len:             number of valid bytes in sense_buffer
2458 * @info_out:           pointer to 64 integer where 8 or 4 byte information
2459 *                      field will be placed if found.
2460 *
2461 * Return value:
2462 *      true if information field found, false if not found.
2463 */
2464bool scsi_get_sense_info_fld(const u8 *sense_buffer, int sb_len,
2465                             u64 *info_out)
2466{
2467        const u8 * ucp;
2468
2469        if (sb_len < 7)
2470                return false;
2471        switch (sense_buffer[0] & 0x7f) {
2472        case 0x70:
2473        case 0x71:
2474                if (sense_buffer[0] & 0x80) {
2475                        *info_out = get_unaligned_be32(&sense_buffer[3]);
2476                        return true;
2477                }
2478                return false;
2479        case 0x72:
2480        case 0x73:
2481                ucp = scsi_sense_desc_find(sense_buffer, sb_len,
2482                                           0 /* info desc */);
2483                if (ucp && (0xa == ucp[1])) {
2484                        *info_out = get_unaligned_be64(&ucp[4]);
2485                        return true;
2486                }
2487                return false;
2488        default:
2489                return false;
2490        }
2491}
2492EXPORT_SYMBOL(scsi_get_sense_info_fld);
2493