1 // SPDX-License-Identifier: GPL-2.0-only
3 * scsi_error.c Copyright (C) 1997 Eric Youngdale
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.
10 * Restructured scsi_unjam_host and associated functions.
11 * September 04, 2002 Mike Anderson (andmike@us.ibm.com)
13 * Forward port of Russell King's (rmk@arm.linux.org.uk) changes and
15 * September 30, 2002 Mike Anderson (andmike@us.ibm.com)
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>
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>
45 #include "scsi_priv.h"
46 #include "scsi_logging.h"
47 #include "scsi_transport_api.h"
49 #include <trace/events/scsi.h>
51 #include <asm/unaligned.h>
54 * These should *probably* be handled by the host itself.
55 * Since it is allowed to sleep, it probably should.
57 #define BUS_RESET_SETTLE_TIME (10)
58 #define HOST_RESET_SETTLE_TIME (10)
60 static int scsi_eh_try_stu(struct scsi_cmnd *scmd);
61 static enum scsi_disposition scsi_try_to_abort_cmd(struct scsi_host_template *,
64 void scsi_eh_wakeup(struct Scsi_Host *shost)
66 lockdep_assert_held(shost->host_lock);
68 if (scsi_host_busy(shost) == shost->host_failed) {
69 trace_scsi_eh_wakeup(shost);
70 wake_up_process(shost->ehandler);
71 SCSI_LOG_ERROR_RECOVERY(5, shost_printk(KERN_INFO, shost,
72 "Waking error handler thread\n"));
77 * scsi_schedule_eh - schedule EH for SCSI host
78 * @shost: SCSI host to invoke error handling on.
80 * Schedule SCSI EH without scmd.
82 void scsi_schedule_eh(struct Scsi_Host *shost)
86 spin_lock_irqsave(shost->host_lock, flags);
88 if (scsi_host_set_state(shost, SHOST_RECOVERY) == 0 ||
89 scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY) == 0) {
90 shost->host_eh_scheduled++;
91 scsi_eh_wakeup(shost);
94 spin_unlock_irqrestore(shost->host_lock, flags);
96 EXPORT_SYMBOL_GPL(scsi_schedule_eh);
98 static int scsi_host_eh_past_deadline(struct Scsi_Host *shost)
100 if (!shost->last_reset || shost->eh_deadline == -1)
104 * 32bit accesses are guaranteed to be atomic
105 * (on all supported architectures), so instead
106 * of using a spinlock we can as well double check
107 * if eh_deadline has been set to 'off' during the
110 if (time_before(jiffies, shost->last_reset + shost->eh_deadline) &&
111 shost->eh_deadline > -1)
117 static bool scsi_cmd_retry_allowed(struct scsi_cmnd *cmd)
119 if (cmd->allowed == SCSI_CMD_RETRIES_NO_LIMIT)
122 return ++cmd->retries <= cmd->allowed;
125 static bool scsi_eh_should_retry_cmd(struct scsi_cmnd *cmd)
127 struct scsi_device *sdev = cmd->device;
128 struct Scsi_Host *host = sdev->host;
130 if (host->hostt->eh_should_retry_cmd)
131 return host->hostt->eh_should_retry_cmd(cmd);
137 * scmd_eh_abort_handler - Handle command aborts
138 * @work: command to be aborted.
140 * Note: this function must be called only for a command that has timed out.
141 * Because the block layer marks a request as complete before it calls
142 * scsi_times_out(), a .scsi_done() call from the LLD for a command that has
143 * timed out do not have any effect. Hence it is safe to call
144 * scsi_finish_command() from this function.
147 scmd_eh_abort_handler(struct work_struct *work)
149 struct scsi_cmnd *scmd =
150 container_of(work, struct scsi_cmnd, abort_work.work);
151 struct scsi_device *sdev = scmd->device;
152 struct Scsi_Host *shost = sdev->host;
153 enum scsi_disposition rtn;
156 if (scsi_host_eh_past_deadline(shost)) {
157 SCSI_LOG_ERROR_RECOVERY(3,
158 scmd_printk(KERN_INFO, scmd,
159 "eh timeout, not aborting\n"));
163 SCSI_LOG_ERROR_RECOVERY(3,
164 scmd_printk(KERN_INFO, scmd,
165 "aborting command\n"));
166 rtn = scsi_try_to_abort_cmd(shost->hostt, scmd);
167 if (rtn != SUCCESS) {
168 SCSI_LOG_ERROR_RECOVERY(3,
169 scmd_printk(KERN_INFO, scmd,
171 (rtn == FAST_IO_FAIL) ?
172 "not send" : "failed"));
175 set_host_byte(scmd, DID_TIME_OUT);
176 if (scsi_host_eh_past_deadline(shost)) {
177 SCSI_LOG_ERROR_RECOVERY(3,
178 scmd_printk(KERN_INFO, scmd,
179 "eh timeout, not retrying "
180 "aborted command\n"));
184 spin_lock_irqsave(shost->host_lock, flags);
185 list_del_init(&scmd->eh_entry);
188 * If the abort succeeds, and there is no further
189 * EH action, clear the ->last_reset time.
191 if (list_empty(&shost->eh_abort_list) &&
192 list_empty(&shost->eh_cmd_q))
193 if (shost->eh_deadline != -1)
194 shost->last_reset = 0;
196 spin_unlock_irqrestore(shost->host_lock, flags);
198 if (!scsi_noretry_cmd(scmd) &&
199 scsi_cmd_retry_allowed(scmd) &&
200 scsi_eh_should_retry_cmd(scmd)) {
201 SCSI_LOG_ERROR_RECOVERY(3,
202 scmd_printk(KERN_WARNING, scmd,
203 "retry aborted command\n"));
204 scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY);
206 SCSI_LOG_ERROR_RECOVERY(3,
207 scmd_printk(KERN_WARNING, scmd,
208 "finish aborted command\n"));
209 scsi_finish_command(scmd);
214 spin_lock_irqsave(shost->host_lock, flags);
215 list_del_init(&scmd->eh_entry);
216 spin_unlock_irqrestore(shost->host_lock, flags);
218 scsi_eh_scmd_add(scmd);
222 * scsi_abort_command - schedule a command abort
223 * @scmd: scmd to abort.
225 * We only need to abort commands after a command timeout
228 scsi_abort_command(struct scsi_cmnd *scmd)
230 struct scsi_device *sdev = scmd->device;
231 struct Scsi_Host *shost = sdev->host;
234 if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) {
236 * Retry after abort failed, escalate to next level.
238 SCSI_LOG_ERROR_RECOVERY(3,
239 scmd_printk(KERN_INFO, scmd,
240 "previous abort failed\n"));
241 BUG_ON(delayed_work_pending(&scmd->abort_work));
245 spin_lock_irqsave(shost->host_lock, flags);
246 if (shost->eh_deadline != -1 && !shost->last_reset)
247 shost->last_reset = jiffies;
248 BUG_ON(!list_empty(&scmd->eh_entry));
249 list_add_tail(&scmd->eh_entry, &shost->eh_abort_list);
250 spin_unlock_irqrestore(shost->host_lock, flags);
252 scmd->eh_eflags |= SCSI_EH_ABORT_SCHEDULED;
253 SCSI_LOG_ERROR_RECOVERY(3,
254 scmd_printk(KERN_INFO, scmd, "abort scheduled\n"));
255 queue_delayed_work(shost->tmf_work_q, &scmd->abort_work, HZ / 100);
260 * scsi_eh_reset - call into ->eh_action to reset internal counters
261 * @scmd: scmd to run eh on.
263 * The scsi driver might be carrying internal state about the
264 * devices, so we need to call into the driver to reset the
265 * internal state once the error handler is started.
267 static void scsi_eh_reset(struct scsi_cmnd *scmd)
269 if (!blk_rq_is_passthrough(scsi_cmd_to_rq(scmd))) {
270 struct scsi_driver *sdrv = scsi_cmd_to_driver(scmd);
272 sdrv->eh_reset(scmd);
276 static void scsi_eh_inc_host_failed(struct rcu_head *head)
278 struct scsi_cmnd *scmd = container_of(head, typeof(*scmd), rcu);
279 struct Scsi_Host *shost = scmd->device->host;
282 spin_lock_irqsave(shost->host_lock, flags);
283 shost->host_failed++;
284 scsi_eh_wakeup(shost);
285 spin_unlock_irqrestore(shost->host_lock, flags);
289 * scsi_eh_scmd_add - add scsi cmd to error handling.
290 * @scmd: scmd to run eh on.
292 void scsi_eh_scmd_add(struct scsi_cmnd *scmd)
294 struct Scsi_Host *shost = scmd->device->host;
298 WARN_ON_ONCE(!shost->ehandler);
300 spin_lock_irqsave(shost->host_lock, flags);
301 if (scsi_host_set_state(shost, SHOST_RECOVERY)) {
302 ret = scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY);
305 if (shost->eh_deadline != -1 && !shost->last_reset)
306 shost->last_reset = jiffies;
309 list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q);
310 spin_unlock_irqrestore(shost->host_lock, flags);
312 * Ensure that all tasks observe the host state change before the
313 * host_failed change.
315 call_rcu(&scmd->rcu, scsi_eh_inc_host_failed);
319 * scsi_times_out - Timeout function for normal scsi commands.
320 * @req: request that is timing out.
323 * We do not need to lock this. There is the potential for a race
324 * only in that the normal completion handling might run, but if the
325 * normal completion function determines that the timer has already
326 * fired, then it mustn't do anything.
328 enum blk_eh_timer_return scsi_times_out(struct request *req)
330 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(req);
331 enum blk_eh_timer_return rtn = BLK_EH_DONE;
332 struct Scsi_Host *host = scmd->device->host;
334 trace_scsi_dispatch_cmd_timeout(scmd);
335 scsi_log_completion(scmd, TIMEOUT_ERROR);
337 if (host->eh_deadline != -1 && !host->last_reset)
338 host->last_reset = jiffies;
340 if (host->hostt->eh_timed_out)
341 rtn = host->hostt->eh_timed_out(scmd);
343 if (rtn == BLK_EH_DONE) {
345 * Set the command to complete first in order to prevent a real
346 * completion from releasing the command while error handling
347 * is using it. If the command was already completed, then the
348 * lower level driver beat the timeout handler, and it is safe
349 * to return without escalating error recovery.
351 * If timeout handling lost the race to a real completion, the
352 * block layer may ignore that due to a fake timeout injection,
353 * so return RESET_TIMER to allow error handling another shot
356 if (test_and_set_bit(SCMD_STATE_COMPLETE, &scmd->state))
357 return BLK_EH_RESET_TIMER;
358 if (scsi_abort_command(scmd) != SUCCESS) {
359 set_host_byte(scmd, DID_TIME_OUT);
360 scsi_eh_scmd_add(scmd);
368 * scsi_block_when_processing_errors - Prevent cmds from being queued.
369 * @sdev: Device on which we are performing recovery.
372 * We block until the host is out of error recovery, and then check to
373 * see whether the host or the device is offline.
376 * 0 when dev was taken offline by error recovery. 1 OK to proceed.
378 int scsi_block_when_processing_errors(struct scsi_device *sdev)
382 wait_event(sdev->host->host_wait, !scsi_host_in_recovery(sdev->host));
384 online = scsi_device_online(sdev);
388 EXPORT_SYMBOL(scsi_block_when_processing_errors);
390 #ifdef CONFIG_SCSI_LOGGING
392 * scsi_eh_prt_fail_stats - Log info on failures.
393 * @shost: scsi host being recovered.
394 * @work_q: Queue of scsi cmds to process.
396 static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost,
397 struct list_head *work_q)
399 struct scsi_cmnd *scmd;
400 struct scsi_device *sdev;
401 int total_failures = 0;
404 int devices_failed = 0;
406 shost_for_each_device(sdev, shost) {
407 list_for_each_entry(scmd, work_q, eh_entry) {
408 if (scmd->device == sdev) {
410 if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED)
417 if (cmd_cancel || cmd_failed) {
418 SCSI_LOG_ERROR_RECOVERY(3,
419 shost_printk(KERN_INFO, shost,
420 "%s: cmds failed: %d, cancel: %d\n",
421 __func__, cmd_failed,
429 SCSI_LOG_ERROR_RECOVERY(2, shost_printk(KERN_INFO, shost,
430 "Total of %d commands on %d"
431 " devices require eh work\n",
432 total_failures, devices_failed));
437 * scsi_report_lun_change - Set flag on all *other* devices on the same target
438 * to indicate that a UNIT ATTENTION is expected.
439 * @sdev: Device reporting the UNIT ATTENTION
441 static void scsi_report_lun_change(struct scsi_device *sdev)
443 sdev->sdev_target->expecting_lun_change = 1;
447 * scsi_report_sense - Examine scsi sense information and log messages for
448 * certain conditions, also issue uevents for some of them.
449 * @sdev: Device reporting the sense code
450 * @sshdr: sshdr to be examined
452 static void scsi_report_sense(struct scsi_device *sdev,
453 struct scsi_sense_hdr *sshdr)
455 enum scsi_device_event evt_type = SDEV_EVT_MAXBITS; /* i.e. none */
457 if (sshdr->sense_key == UNIT_ATTENTION) {
458 if (sshdr->asc == 0x3f && sshdr->ascq == 0x03) {
459 evt_type = SDEV_EVT_INQUIRY_CHANGE_REPORTED;
460 sdev_printk(KERN_WARNING, sdev,
461 "Inquiry data has changed");
462 } else if (sshdr->asc == 0x3f && sshdr->ascq == 0x0e) {
463 evt_type = SDEV_EVT_LUN_CHANGE_REPORTED;
464 scsi_report_lun_change(sdev);
465 sdev_printk(KERN_WARNING, sdev,
466 "Warning! Received an indication that the "
467 "LUN assignments on this target have "
468 "changed. The Linux SCSI layer does not "
469 "automatically remap LUN assignments.\n");
470 } else if (sshdr->asc == 0x3f)
471 sdev_printk(KERN_WARNING, sdev,
472 "Warning! Received an indication that the "
473 "operating parameters on this target have "
474 "changed. The Linux SCSI layer does not "
475 "automatically adjust these parameters.\n");
477 if (sshdr->asc == 0x38 && sshdr->ascq == 0x07) {
478 evt_type = SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED;
479 sdev_printk(KERN_WARNING, sdev,
480 "Warning! Received an indication that the "
481 "LUN reached a thin provisioning soft "
485 if (sshdr->asc == 0x29) {
486 evt_type = SDEV_EVT_POWER_ON_RESET_OCCURRED;
487 sdev_printk(KERN_WARNING, sdev,
488 "Power-on or device reset occurred\n");
491 if (sshdr->asc == 0x2a && sshdr->ascq == 0x01) {
492 evt_type = SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED;
493 sdev_printk(KERN_WARNING, sdev,
494 "Mode parameters changed");
495 } else if (sshdr->asc == 0x2a && sshdr->ascq == 0x06) {
496 evt_type = SDEV_EVT_ALUA_STATE_CHANGE_REPORTED;
497 sdev_printk(KERN_WARNING, sdev,
498 "Asymmetric access state changed");
499 } else if (sshdr->asc == 0x2a && sshdr->ascq == 0x09) {
500 evt_type = SDEV_EVT_CAPACITY_CHANGE_REPORTED;
501 sdev_printk(KERN_WARNING, sdev,
502 "Capacity data has changed");
503 } else if (sshdr->asc == 0x2a)
504 sdev_printk(KERN_WARNING, sdev,
505 "Parameters changed");
508 if (evt_type != SDEV_EVT_MAXBITS) {
509 set_bit(evt_type, sdev->pending_events);
510 schedule_work(&sdev->event_work);
515 * scsi_check_sense - Examine scsi cmd sense
516 * @scmd: Cmd to have sense checked.
519 * SUCCESS or FAILED or NEEDS_RETRY or ADD_TO_MLQUEUE
522 * When a deferred error is detected the current command has
523 * not been executed and needs retrying.
525 enum scsi_disposition scsi_check_sense(struct scsi_cmnd *scmd)
527 struct scsi_device *sdev = scmd->device;
528 struct scsi_sense_hdr sshdr;
530 if (! scsi_command_normalize_sense(scmd, &sshdr))
531 return FAILED; /* no valid sense data */
533 scsi_report_sense(sdev, &sshdr);
535 if (scsi_sense_is_deferred(&sshdr))
538 if (sdev->handler && sdev->handler->check_sense) {
539 enum scsi_disposition rc;
541 rc = sdev->handler->check_sense(sdev, &sshdr);
542 if (rc != SCSI_RETURN_NOT_HANDLED)
544 /* handler does not care. Drop down to default handling */
547 if (scmd->cmnd[0] == TEST_UNIT_READY &&
548 scmd->submitter != SUBMITTED_BY_SCSI_ERROR_HANDLER)
550 * nasty: for mid-layer issued TURs, we need to return the
551 * actual sense data without any recovery attempt. For eh
552 * issued ones, we need to try to recover and interpret
557 * Previous logic looked for FILEMARK, EOM or ILI which are
558 * mainly associated with tapes and returned SUCCESS.
560 if (sshdr.response_code == 0x70) {
562 if (scmd->sense_buffer[2] & 0xe0)
566 * descriptor format: look for "stream commands sense data
567 * descriptor" (see SSC-3). Assume single sense data
568 * descriptor. Ignore ILI from SBC-2 READ LONG and WRITE LONG.
570 if ((sshdr.additional_length > 3) &&
571 (scmd->sense_buffer[8] == 0x4) &&
572 (scmd->sense_buffer[11] & 0xe0))
576 switch (sshdr.sense_key) {
579 case RECOVERED_ERROR:
580 return /* soft_error */ SUCCESS;
582 case ABORTED_COMMAND:
583 if (sshdr.asc == 0x10) /* DIF */
586 if (sshdr.asc == 0x44 && sdev->sdev_bflags & BLIST_RETRY_ITF)
587 return ADD_TO_MLQUEUE;
588 if (sshdr.asc == 0xc1 && sshdr.ascq == 0x01 &&
589 sdev->sdev_bflags & BLIST_RETRY_ASC_C1)
590 return ADD_TO_MLQUEUE;
596 * if we are expecting a cc/ua because of a bus reset that we
597 * performed, treat this just as a retry. otherwise this is
598 * information that we should pass up to the upper-level driver
599 * so that we can deal with it there.
601 if (scmd->device->expecting_cc_ua) {
603 * Because some device does not queue unit
604 * attentions correctly, we carefully check
605 * additional sense code and qualifier so as
606 * not to squash media change unit attention.
608 if (sshdr.asc != 0x28 || sshdr.ascq != 0x00) {
609 scmd->device->expecting_cc_ua = 0;
614 * we might also expect a cc/ua if another LUN on the target
615 * reported a UA with an ASC/ASCQ of 3F 0E -
616 * REPORTED LUNS DATA HAS CHANGED.
618 if (scmd->device->sdev_target->expecting_lun_change &&
619 sshdr.asc == 0x3f && sshdr.ascq == 0x0e)
622 * if the device is in the process of becoming ready, we
625 if ((sshdr.asc == 0x04) && (sshdr.ascq == 0x01))
628 * if the device is not started, we need to wake
629 * the error handler to start the motor
631 if (scmd->device->allow_restart &&
632 (sshdr.asc == 0x04) && (sshdr.ascq == 0x02))
635 * Pass the UA upwards for a determination in the completion
640 /* these are not supported */
642 if (sshdr.asc == 0x27 && sshdr.ascq == 0x07) {
643 /* Thin provisioning hard threshold reached */
644 set_host_byte(scmd, DID_ALLOC_FAILURE);
649 case VOLUME_OVERFLOW:
652 set_host_byte(scmd, DID_TARGET_FAILURE);
656 if (sshdr.asc == 0x11 || /* UNRECOVERED READ ERR */
657 sshdr.asc == 0x13 || /* AMNF DATA FIELD */
658 sshdr.asc == 0x14) { /* RECORD NOT FOUND */
659 set_host_byte(scmd, DID_MEDIUM_ERROR);
665 if (scmd->device->retry_hwerror)
666 return ADD_TO_MLQUEUE;
668 set_host_byte(scmd, DID_TARGET_FAILURE);
671 case ILLEGAL_REQUEST:
672 if (sshdr.asc == 0x20 || /* Invalid command operation code */
673 sshdr.asc == 0x21 || /* Logical block address out of range */
674 sshdr.asc == 0x22 || /* Invalid function */
675 sshdr.asc == 0x24 || /* Invalid field in cdb */
676 sshdr.asc == 0x26 || /* Parameter value invalid */
677 sshdr.asc == 0x27) { /* Write protected */
678 set_host_byte(scmd, DID_TARGET_FAILURE);
686 EXPORT_SYMBOL_GPL(scsi_check_sense);
688 static void scsi_handle_queue_ramp_up(struct scsi_device *sdev)
690 struct scsi_host_template *sht = sdev->host->hostt;
691 struct scsi_device *tmp_sdev;
693 if (!sht->track_queue_depth ||
694 sdev->queue_depth >= sdev->max_queue_depth)
697 if (time_before(jiffies,
698 sdev->last_queue_ramp_up + sdev->queue_ramp_up_period))
701 if (time_before(jiffies,
702 sdev->last_queue_full_time + sdev->queue_ramp_up_period))
706 * Walk all devices of a target and do
709 shost_for_each_device(tmp_sdev, sdev->host) {
710 if (tmp_sdev->channel != sdev->channel ||
711 tmp_sdev->id != sdev->id ||
712 tmp_sdev->queue_depth == sdev->max_queue_depth)
715 scsi_change_queue_depth(tmp_sdev, tmp_sdev->queue_depth + 1);
716 sdev->last_queue_ramp_up = jiffies;
720 static void scsi_handle_queue_full(struct scsi_device *sdev)
722 struct scsi_host_template *sht = sdev->host->hostt;
723 struct scsi_device *tmp_sdev;
725 if (!sht->track_queue_depth)
728 shost_for_each_device(tmp_sdev, sdev->host) {
729 if (tmp_sdev->channel != sdev->channel ||
730 tmp_sdev->id != sdev->id)
733 * We do not know the number of commands that were at
734 * the device when we got the queue full so we start
735 * from the highest possible value and work our way down.
737 scsi_track_queue_full(tmp_sdev, tmp_sdev->queue_depth - 1);
742 * scsi_eh_completed_normally - Disposition a eh cmd on return from LLD.
743 * @scmd: SCSI cmd to examine.
746 * This is *only* called when we are examining the status of commands
747 * queued during error recovery. the main difference here is that we
748 * don't allow for the possibility of retries here, and we are a lot
749 * more restrictive about what we consider acceptable.
751 static enum scsi_disposition scsi_eh_completed_normally(struct scsi_cmnd *scmd)
754 * first check the host byte, to see if there is anything in there
755 * that would indicate what we need to do.
757 if (host_byte(scmd->result) == DID_RESET) {
759 * rats. we are already in the error handler, so we now
760 * get to try and figure out what to do next. if the sense
761 * is valid, we have a pretty good idea of what to do.
762 * if not, we mark it as FAILED.
764 return scsi_check_sense(scmd);
766 if (host_byte(scmd->result) != DID_OK)
770 * now, check the status byte to see if this indicates
773 switch (get_status_byte(scmd)) {
775 scsi_handle_queue_ramp_up(scmd->device);
777 case SAM_STAT_COMMAND_TERMINATED:
779 case SAM_STAT_CHECK_CONDITION:
780 return scsi_check_sense(scmd);
781 case SAM_STAT_CONDITION_MET:
782 case SAM_STAT_INTERMEDIATE:
783 case SAM_STAT_INTERMEDIATE_CONDITION_MET:
785 * who knows? FIXME(eric)
788 case SAM_STAT_RESERVATION_CONFLICT:
789 if (scmd->cmnd[0] == TEST_UNIT_READY)
790 /* it is a success, we probed the device and
793 /* otherwise, we failed to send the command */
795 case SAM_STAT_TASK_SET_FULL:
796 scsi_handle_queue_full(scmd->device);
807 * scsi_eh_done - Completion function for error handling.
808 * @scmd: Cmd that is done.
810 void scsi_eh_done(struct scsi_cmnd *scmd)
812 struct completion *eh_action;
814 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
815 "%s result: %x\n", __func__, scmd->result));
817 eh_action = scmd->device->host->eh_action;
823 * scsi_try_host_reset - ask host adapter to reset itself
824 * @scmd: SCSI cmd to send host reset.
826 static enum scsi_disposition scsi_try_host_reset(struct scsi_cmnd *scmd)
829 enum scsi_disposition rtn;
830 struct Scsi_Host *host = scmd->device->host;
831 struct scsi_host_template *hostt = host->hostt;
833 SCSI_LOG_ERROR_RECOVERY(3,
834 shost_printk(KERN_INFO, host, "Snd Host RST\n"));
836 if (!hostt->eh_host_reset_handler)
839 rtn = hostt->eh_host_reset_handler(scmd);
841 if (rtn == SUCCESS) {
842 if (!hostt->skip_settle_delay)
843 ssleep(HOST_RESET_SETTLE_TIME);
844 spin_lock_irqsave(host->host_lock, flags);
845 scsi_report_bus_reset(host, scmd_channel(scmd));
846 spin_unlock_irqrestore(host->host_lock, flags);
853 * scsi_try_bus_reset - ask host to perform a bus reset
854 * @scmd: SCSI cmd to send bus reset.
856 static enum scsi_disposition scsi_try_bus_reset(struct scsi_cmnd *scmd)
859 enum scsi_disposition rtn;
860 struct Scsi_Host *host = scmd->device->host;
861 struct scsi_host_template *hostt = host->hostt;
863 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
864 "%s: Snd Bus RST\n", __func__));
866 if (!hostt->eh_bus_reset_handler)
869 rtn = hostt->eh_bus_reset_handler(scmd);
871 if (rtn == SUCCESS) {
872 if (!hostt->skip_settle_delay)
873 ssleep(BUS_RESET_SETTLE_TIME);
874 spin_lock_irqsave(host->host_lock, flags);
875 scsi_report_bus_reset(host, scmd_channel(scmd));
876 spin_unlock_irqrestore(host->host_lock, flags);
882 static void __scsi_report_device_reset(struct scsi_device *sdev, void *data)
885 sdev->expecting_cc_ua = 1;
889 * scsi_try_target_reset - Ask host to perform a target reset
890 * @scmd: SCSI cmd used to send a target reset
893 * There is no timeout for this operation. if this operation is
894 * unreliable for a given host, then the host itself needs to put a
895 * timer on it, and set the host back to a consistent state prior to
898 static enum scsi_disposition scsi_try_target_reset(struct scsi_cmnd *scmd)
901 enum scsi_disposition rtn;
902 struct Scsi_Host *host = scmd->device->host;
903 struct scsi_host_template *hostt = host->hostt;
905 if (!hostt->eh_target_reset_handler)
908 rtn = hostt->eh_target_reset_handler(scmd);
909 if (rtn == SUCCESS) {
910 spin_lock_irqsave(host->host_lock, flags);
911 __starget_for_each_device(scsi_target(scmd->device), NULL,
912 __scsi_report_device_reset);
913 spin_unlock_irqrestore(host->host_lock, flags);
920 * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev
921 * @scmd: SCSI cmd used to send BDR
924 * There is no timeout for this operation. if this operation is
925 * unreliable for a given host, then the host itself needs to put a
926 * timer on it, and set the host back to a consistent state prior to
929 static enum scsi_disposition scsi_try_bus_device_reset(struct scsi_cmnd *scmd)
931 enum scsi_disposition rtn;
932 struct scsi_host_template *hostt = scmd->device->host->hostt;
934 if (!hostt->eh_device_reset_handler)
937 rtn = hostt->eh_device_reset_handler(scmd);
939 __scsi_report_device_reset(scmd->device, NULL);
944 * scsi_try_to_abort_cmd - Ask host to abort a SCSI command
945 * @hostt: SCSI driver host template
946 * @scmd: SCSI cmd used to send a target reset
949 * SUCCESS, FAILED, or FAST_IO_FAIL
952 * SUCCESS does not necessarily indicate that the command
953 * has been aborted; it only indicates that the LLDDs
954 * has cleared all references to that command.
955 * LLDDs should return FAILED only if an abort was required
956 * but could not be executed. LLDDs should return FAST_IO_FAIL
957 * if the device is temporarily unavailable (eg due to a
958 * link down on FibreChannel)
960 static enum scsi_disposition
961 scsi_try_to_abort_cmd(struct scsi_host_template *hostt, struct scsi_cmnd *scmd)
963 if (!hostt->eh_abort_handler)
966 return hostt->eh_abort_handler(scmd);
969 static void scsi_abort_eh_cmnd(struct scsi_cmnd *scmd)
971 if (scsi_try_to_abort_cmd(scmd->device->host->hostt, scmd) != SUCCESS)
972 if (scsi_try_bus_device_reset(scmd) != SUCCESS)
973 if (scsi_try_target_reset(scmd) != SUCCESS)
974 if (scsi_try_bus_reset(scmd) != SUCCESS)
975 scsi_try_host_reset(scmd);
979 * scsi_eh_prep_cmnd - Save a scsi command info as part of error recovery
980 * @scmd: SCSI command structure to hijack
981 * @ses: structure to save restore information
982 * @cmnd: CDB to send. Can be NULL if no new cmnd is needed
983 * @cmnd_size: size in bytes of @cmnd (must be <= BLK_MAX_CDB)
984 * @sense_bytes: size of sense data to copy. or 0 (if != 0 @cmnd is ignored)
986 * This function is used to save a scsi command information before re-execution
987 * as part of the error recovery process. If @sense_bytes is 0 the command
988 * sent must be one that does not transfer any data. If @sense_bytes != 0
989 * @cmnd is ignored and this functions sets up a REQUEST_SENSE command
990 * and cmnd buffers to read @sense_bytes into @scmd->sense_buffer.
992 void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd, struct scsi_eh_save *ses,
993 unsigned char *cmnd, int cmnd_size, unsigned sense_bytes)
995 struct scsi_device *sdev = scmd->device;
998 * We need saved copies of a number of fields - this is because
999 * error handling may need to overwrite these with different values
1000 * to run different commands, and once error handling is complete,
1001 * we will need to restore these values prior to running the actual
1004 ses->cmd_len = scmd->cmd_len;
1005 ses->cmnd = scmd->cmnd;
1006 ses->data_direction = scmd->sc_data_direction;
1007 ses->sdb = scmd->sdb;
1008 ses->result = scmd->result;
1009 ses->resid_len = scmd->req.resid_len;
1010 ses->underflow = scmd->underflow;
1011 ses->prot_op = scmd->prot_op;
1012 ses->eh_eflags = scmd->eh_eflags;
1014 scmd->prot_op = SCSI_PROT_NORMAL;
1015 scmd->eh_eflags = 0;
1016 scmd->cmnd = ses->eh_cmnd;
1017 memset(scmd->cmnd, 0, BLK_MAX_CDB);
1018 memset(&scmd->sdb, 0, sizeof(scmd->sdb));
1020 scmd->req.resid_len = 0;
1023 scmd->sdb.length = min_t(unsigned, SCSI_SENSE_BUFFERSIZE,
1025 sg_init_one(&ses->sense_sgl, scmd->sense_buffer,
1027 scmd->sdb.table.sgl = &ses->sense_sgl;
1028 scmd->sc_data_direction = DMA_FROM_DEVICE;
1029 scmd->sdb.table.nents = scmd->sdb.table.orig_nents = 1;
1030 scmd->cmnd[0] = REQUEST_SENSE;
1031 scmd->cmnd[4] = scmd->sdb.length;
1032 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
1034 scmd->sc_data_direction = DMA_NONE;
1036 BUG_ON(cmnd_size > BLK_MAX_CDB);
1037 memcpy(scmd->cmnd, cmnd, cmnd_size);
1038 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
1042 scmd->underflow = 0;
1044 if (sdev->scsi_level <= SCSI_2 && sdev->scsi_level != SCSI_UNKNOWN)
1045 scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) |
1046 (sdev->lun << 5 & 0xe0);
1049 * Zero the sense buffer. The scsi spec mandates that any
1050 * untransferred sense data should be interpreted as being zero.
1052 memset(scmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
1054 EXPORT_SYMBOL(scsi_eh_prep_cmnd);
1057 * scsi_eh_restore_cmnd - Restore a scsi command info as part of error recovery
1058 * @scmd: SCSI command structure to restore
1059 * @ses: saved information from a coresponding call to scsi_eh_prep_cmnd
1061 * Undo any damage done by above scsi_eh_prep_cmnd().
1063 void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd, struct scsi_eh_save *ses)
1066 * Restore original data
1068 scmd->cmd_len = ses->cmd_len;
1069 scmd->cmnd = ses->cmnd;
1070 scmd->sc_data_direction = ses->data_direction;
1071 scmd->sdb = ses->sdb;
1072 scmd->result = ses->result;
1073 scmd->req.resid_len = ses->resid_len;
1074 scmd->underflow = ses->underflow;
1075 scmd->prot_op = ses->prot_op;
1076 scmd->eh_eflags = ses->eh_eflags;
1078 EXPORT_SYMBOL(scsi_eh_restore_cmnd);
1081 * scsi_send_eh_cmnd - submit a scsi command as part of error recovery
1082 * @scmd: SCSI command structure to hijack
1083 * @cmnd: CDB to send
1084 * @cmnd_size: size in bytes of @cmnd
1085 * @timeout: timeout for this request
1086 * @sense_bytes: size of sense data to copy or 0
1088 * This function is used to send a scsi command down to a target device
1089 * as part of the error recovery process. See also scsi_eh_prep_cmnd() above.
1092 * SUCCESS or FAILED or NEEDS_RETRY
1094 static enum scsi_disposition scsi_send_eh_cmnd(struct scsi_cmnd *scmd,
1095 unsigned char *cmnd, int cmnd_size, int timeout, unsigned sense_bytes)
1097 struct scsi_device *sdev = scmd->device;
1098 struct Scsi_Host *shost = sdev->host;
1099 DECLARE_COMPLETION_ONSTACK(done);
1100 unsigned long timeleft = timeout, delay;
1101 struct scsi_eh_save ses;
1102 const unsigned long stall_for = msecs_to_jiffies(100);
1106 scsi_eh_prep_cmnd(scmd, &ses, cmnd, cmnd_size, sense_bytes);
1107 shost->eh_action = &done;
1109 scsi_log_send(scmd);
1110 scmd->submitter = SUBMITTED_BY_SCSI_ERROR_HANDLER;
1113 * Lock sdev->state_mutex to avoid that scsi_device_quiesce() can
1114 * change the SCSI device state after we have examined it and before
1115 * .queuecommand() is called.
1117 mutex_lock(&sdev->state_mutex);
1118 while (sdev->sdev_state == SDEV_BLOCK && timeleft > 0) {
1119 mutex_unlock(&sdev->state_mutex);
1120 SCSI_LOG_ERROR_RECOVERY(5, sdev_printk(KERN_DEBUG, sdev,
1121 "%s: state %d <> %d\n", __func__, sdev->sdev_state,
1123 delay = min(timeleft, stall_for);
1125 msleep(jiffies_to_msecs(delay));
1126 mutex_lock(&sdev->state_mutex);
1128 if (sdev->sdev_state != SDEV_BLOCK)
1129 rtn = shost->hostt->queuecommand(shost, scmd);
1132 mutex_unlock(&sdev->state_mutex);
1135 if (timeleft > stall_for) {
1136 scsi_eh_restore_cmnd(scmd, &ses);
1138 timeleft -= stall_for;
1139 msleep(jiffies_to_msecs(stall_for));
1142 /* signal not to enter either branch of the if () below */
1146 timeleft = wait_for_completion_timeout(&done, timeout);
1150 shost->eh_action = NULL;
1152 scsi_log_completion(scmd, rtn);
1154 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1155 "%s timeleft: %ld\n",
1156 __func__, timeleft));
1159 * If there is time left scsi_eh_done got called, and we will examine
1160 * the actual status codes to see whether the command actually did
1161 * complete normally, else if we have a zero return and no time left,
1162 * the command must still be pending, so abort it and return FAILED.
1163 * If we never actually managed to issue the command, because
1164 * ->queuecommand() kept returning non zero, use the rtn = FAILED
1165 * value above (so don't execute either branch of the if)
1168 rtn = scsi_eh_completed_normally(scmd);
1169 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1170 "%s: scsi_eh_completed_normally %x\n", __func__, rtn));
1177 case ADD_TO_MLQUEUE:
1184 } else if (rtn != FAILED) {
1185 scsi_abort_eh_cmnd(scmd);
1189 scsi_eh_restore_cmnd(scmd, &ses);
1195 * scsi_request_sense - Request sense data from a particular target.
1196 * @scmd: SCSI cmd for request sense.
1199 * Some hosts automatically obtain this information, others require
1200 * that we obtain it on our own. This function will *not* return until
1201 * the command either times out, or it completes.
1203 static enum scsi_disposition scsi_request_sense(struct scsi_cmnd *scmd)
1205 return scsi_send_eh_cmnd(scmd, NULL, 0, scmd->device->eh_timeout, ~0);
1208 static enum scsi_disposition
1209 scsi_eh_action(struct scsi_cmnd *scmd, enum scsi_disposition rtn)
1211 if (!blk_rq_is_passthrough(scsi_cmd_to_rq(scmd))) {
1212 struct scsi_driver *sdrv = scsi_cmd_to_driver(scmd);
1213 if (sdrv->eh_action)
1214 rtn = sdrv->eh_action(scmd, rtn);
1220 * scsi_eh_finish_cmd - Handle a cmd that eh is finished with.
1221 * @scmd: Original SCSI cmd that eh has finished.
1222 * @done_q: Queue for processed commands.
1225 * We don't want to use the normal command completion while we are are
1226 * still handling errors - it may cause other commands to be queued,
1227 * and that would disturb what we are doing. Thus we really want to
1228 * keep a list of pending commands for final completion, and once we
1229 * are ready to leave error handling we handle completion for real.
1231 void scsi_eh_finish_cmd(struct scsi_cmnd *scmd, struct list_head *done_q)
1233 list_move_tail(&scmd->eh_entry, done_q);
1235 EXPORT_SYMBOL(scsi_eh_finish_cmd);
1238 * scsi_eh_get_sense - Get device sense data.
1239 * @work_q: Queue of commands to process.
1240 * @done_q: Queue of processed commands.
1243 * See if we need to request sense information. if so, then get it
1244 * now, so we have a better idea of what to do.
1247 * This has the unfortunate side effect that if a shost adapter does
1248 * not automatically request sense information, we end up shutting
1249 * it down before we request it.
1251 * All drivers should request sense information internally these days,
1252 * so for now all I have to say is tough noogies if you end up in here.
1254 * XXX: Long term this code should go away, but that needs an audit of
1257 int scsi_eh_get_sense(struct list_head *work_q,
1258 struct list_head *done_q)
1260 struct scsi_cmnd *scmd, *next;
1261 struct Scsi_Host *shost;
1262 enum scsi_disposition rtn;
1265 * If SCSI_EH_ABORT_SCHEDULED has been set, it is timeout IO,
1266 * should not get sense.
1268 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1269 if ((scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) ||
1270 SCSI_SENSE_VALID(scmd))
1273 shost = scmd->device->host;
1274 if (scsi_host_eh_past_deadline(shost)) {
1275 SCSI_LOG_ERROR_RECOVERY(3,
1276 scmd_printk(KERN_INFO, scmd,
1277 "%s: skip request sense, past eh deadline\n",
1281 if (!scsi_status_is_check_condition(scmd->result))
1283 * don't request sense if there's no check condition
1284 * status because the error we're processing isn't one
1285 * that has a sense code (and some devices get
1286 * confused by sense requests out of the blue)
1290 SCSI_LOG_ERROR_RECOVERY(2, scmd_printk(KERN_INFO, scmd,
1291 "%s: requesting sense\n",
1293 rtn = scsi_request_sense(scmd);
1297 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1298 "sense requested, result %x\n", scmd->result));
1299 SCSI_LOG_ERROR_RECOVERY(3, scsi_print_sense(scmd));
1301 rtn = scsi_decide_disposition(scmd);
1304 * if the result was normal, then just pass it along to the
1309 * We don't want this command reissued, just finished
1310 * with the sense data, so set retries to the max
1311 * allowed to ensure it won't get reissued. If the user
1312 * has requested infinite retries, we also want to
1313 * finish this command, so force completion by setting
1314 * retries and allowed to the same value.
1316 if (scmd->allowed == SCSI_CMD_RETRIES_NO_LIMIT)
1317 scmd->retries = scmd->allowed = 1;
1319 scmd->retries = scmd->allowed;
1320 else if (rtn != NEEDS_RETRY)
1323 scsi_eh_finish_cmd(scmd, done_q);
1326 return list_empty(work_q);
1328 EXPORT_SYMBOL_GPL(scsi_eh_get_sense);
1331 * scsi_eh_tur - Send TUR to device.
1332 * @scmd: &scsi_cmnd to send TUR
1335 * 0 - Device is ready. 1 - Device NOT ready.
1337 static int scsi_eh_tur(struct scsi_cmnd *scmd)
1339 static unsigned char tur_command[6] = {TEST_UNIT_READY, 0, 0, 0, 0, 0};
1341 enum scsi_disposition rtn;
1344 rtn = scsi_send_eh_cmnd(scmd, tur_command, 6,
1345 scmd->device->eh_timeout, 0);
1347 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1348 "%s return: %x\n", __func__, rtn));
1363 * scsi_eh_test_devices - check if devices are responding from error recovery.
1364 * @cmd_list: scsi commands in error recovery.
1365 * @work_q: queue for commands which still need more error recovery
1366 * @done_q: queue for commands which are finished
1367 * @try_stu: boolean on if a STU command should be tried in addition to TUR.
1370 * Tests if devices are in a working state. Commands to devices now in
1371 * a working state are sent to the done_q while commands to devices which
1372 * are still failing to respond are returned to the work_q for more
1375 static int scsi_eh_test_devices(struct list_head *cmd_list,
1376 struct list_head *work_q,
1377 struct list_head *done_q, int try_stu)
1379 struct scsi_cmnd *scmd, *next;
1380 struct scsi_device *sdev;
1383 while (!list_empty(cmd_list)) {
1384 scmd = list_entry(cmd_list->next, struct scsi_cmnd, eh_entry);
1385 sdev = scmd->device;
1388 if (scsi_host_eh_past_deadline(sdev->host)) {
1389 /* Push items back onto work_q */
1390 list_splice_init(cmd_list, work_q);
1391 SCSI_LOG_ERROR_RECOVERY(3,
1392 sdev_printk(KERN_INFO, sdev,
1393 "%s: skip test device, past eh deadline",
1399 finish_cmds = !scsi_device_online(scmd->device) ||
1400 (try_stu && !scsi_eh_try_stu(scmd) &&
1401 !scsi_eh_tur(scmd)) ||
1404 list_for_each_entry_safe(scmd, next, cmd_list, eh_entry)
1405 if (scmd->device == sdev) {
1408 scsi_eh_action(scmd, SUCCESS) == SUCCESS))
1409 scsi_eh_finish_cmd(scmd, done_q);
1411 list_move_tail(&scmd->eh_entry, work_q);
1414 return list_empty(work_q);
1418 * scsi_eh_try_stu - Send START_UNIT to device.
1419 * @scmd: &scsi_cmnd to send START_UNIT
1422 * 0 - Device is ready. 1 - Device NOT ready.
1424 static int scsi_eh_try_stu(struct scsi_cmnd *scmd)
1426 static unsigned char stu_command[6] = {START_STOP, 0, 0, 0, 1, 0};
1428 if (scmd->device->allow_restart) {
1430 enum scsi_disposition rtn = NEEDS_RETRY;
1432 for (i = 0; rtn == NEEDS_RETRY && i < 2; i++)
1433 rtn = scsi_send_eh_cmnd(scmd, stu_command, 6,
1434 scmd->device->eh_timeout, 0);
1444 * scsi_eh_stu - send START_UNIT if needed
1445 * @shost: &scsi host being recovered.
1446 * @work_q: &list_head for pending commands.
1447 * @done_q: &list_head for processed commands.
1450 * If commands are failing due to not ready, initializing command required,
1451 * try revalidating the device, which will end up sending a start unit.
1453 static int scsi_eh_stu(struct Scsi_Host *shost,
1454 struct list_head *work_q,
1455 struct list_head *done_q)
1457 struct scsi_cmnd *scmd, *stu_scmd, *next;
1458 struct scsi_device *sdev;
1460 shost_for_each_device(sdev, shost) {
1461 if (scsi_host_eh_past_deadline(shost)) {
1462 SCSI_LOG_ERROR_RECOVERY(3,
1463 sdev_printk(KERN_INFO, sdev,
1464 "%s: skip START_UNIT, past eh deadline\n",
1466 scsi_device_put(sdev);
1470 list_for_each_entry(scmd, work_q, eh_entry)
1471 if (scmd->device == sdev && SCSI_SENSE_VALID(scmd) &&
1472 scsi_check_sense(scmd) == FAILED ) {
1480 SCSI_LOG_ERROR_RECOVERY(3,
1481 sdev_printk(KERN_INFO, sdev,
1482 "%s: Sending START_UNIT\n",
1485 if (!scsi_eh_try_stu(stu_scmd)) {
1486 if (!scsi_device_online(sdev) ||
1487 !scsi_eh_tur(stu_scmd)) {
1488 list_for_each_entry_safe(scmd, next,
1490 if (scmd->device == sdev &&
1491 scsi_eh_action(scmd, SUCCESS) == SUCCESS)
1492 scsi_eh_finish_cmd(scmd, done_q);
1496 SCSI_LOG_ERROR_RECOVERY(3,
1497 sdev_printk(KERN_INFO, sdev,
1498 "%s: START_UNIT failed\n",
1503 return list_empty(work_q);
1508 * scsi_eh_bus_device_reset - send bdr if needed
1509 * @shost: scsi host being recovered.
1510 * @work_q: &list_head for pending commands.
1511 * @done_q: &list_head for processed commands.
1514 * Try a bus device reset. Still, look to see whether we have multiple
1515 * devices that are jammed or not - if we have multiple devices, it
1516 * makes no sense to try bus_device_reset - we really would need to try
1517 * a bus_reset instead.
1519 static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
1520 struct list_head *work_q,
1521 struct list_head *done_q)
1523 struct scsi_cmnd *scmd, *bdr_scmd, *next;
1524 struct scsi_device *sdev;
1525 enum scsi_disposition rtn;
1527 shost_for_each_device(sdev, shost) {
1528 if (scsi_host_eh_past_deadline(shost)) {
1529 SCSI_LOG_ERROR_RECOVERY(3,
1530 sdev_printk(KERN_INFO, sdev,
1531 "%s: skip BDR, past eh deadline\n",
1533 scsi_device_put(sdev);
1537 list_for_each_entry(scmd, work_q, eh_entry)
1538 if (scmd->device == sdev) {
1546 SCSI_LOG_ERROR_RECOVERY(3,
1547 sdev_printk(KERN_INFO, sdev,
1548 "%s: Sending BDR\n", current->comm));
1549 rtn = scsi_try_bus_device_reset(bdr_scmd);
1550 if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
1551 if (!scsi_device_online(sdev) ||
1552 rtn == FAST_IO_FAIL ||
1553 !scsi_eh_tur(bdr_scmd)) {
1554 list_for_each_entry_safe(scmd, next,
1556 if (scmd->device == sdev &&
1557 scsi_eh_action(scmd, rtn) != FAILED)
1558 scsi_eh_finish_cmd(scmd,
1563 SCSI_LOG_ERROR_RECOVERY(3,
1564 sdev_printk(KERN_INFO, sdev,
1565 "%s: BDR failed\n", current->comm));
1569 return list_empty(work_q);
1573 * scsi_eh_target_reset - send target reset if needed
1574 * @shost: scsi host being recovered.
1575 * @work_q: &list_head for pending commands.
1576 * @done_q: &list_head for processed commands.
1579 * Try a target reset.
1581 static int scsi_eh_target_reset(struct Scsi_Host *shost,
1582 struct list_head *work_q,
1583 struct list_head *done_q)
1585 LIST_HEAD(tmp_list);
1586 LIST_HEAD(check_list);
1588 list_splice_init(work_q, &tmp_list);
1590 while (!list_empty(&tmp_list)) {
1591 struct scsi_cmnd *next, *scmd;
1592 enum scsi_disposition rtn;
1595 if (scsi_host_eh_past_deadline(shost)) {
1596 /* push back on work queue for further processing */
1597 list_splice_init(&check_list, work_q);
1598 list_splice_init(&tmp_list, work_q);
1599 SCSI_LOG_ERROR_RECOVERY(3,
1600 shost_printk(KERN_INFO, shost,
1601 "%s: Skip target reset, past eh deadline\n",
1603 return list_empty(work_q);
1606 scmd = list_entry(tmp_list.next, struct scsi_cmnd, eh_entry);
1609 SCSI_LOG_ERROR_RECOVERY(3,
1610 shost_printk(KERN_INFO, shost,
1611 "%s: Sending target reset to target %d\n",
1612 current->comm, id));
1613 rtn = scsi_try_target_reset(scmd);
1614 if (rtn != SUCCESS && rtn != FAST_IO_FAIL)
1615 SCSI_LOG_ERROR_RECOVERY(3,
1616 shost_printk(KERN_INFO, shost,
1617 "%s: Target reset failed"
1619 current->comm, id));
1620 list_for_each_entry_safe(scmd, next, &tmp_list, eh_entry) {
1621 if (scmd_id(scmd) != id)
1625 list_move_tail(&scmd->eh_entry, &check_list);
1626 else if (rtn == FAST_IO_FAIL)
1627 scsi_eh_finish_cmd(scmd, done_q);
1629 /* push back on work queue for further processing */
1630 list_move(&scmd->eh_entry, work_q);
1634 return scsi_eh_test_devices(&check_list, work_q, done_q, 0);
1638 * scsi_eh_bus_reset - send a bus reset
1639 * @shost: &scsi host being recovered.
1640 * @work_q: &list_head for pending commands.
1641 * @done_q: &list_head for processed commands.
1643 static int scsi_eh_bus_reset(struct Scsi_Host *shost,
1644 struct list_head *work_q,
1645 struct list_head *done_q)
1647 struct scsi_cmnd *scmd, *chan_scmd, *next;
1648 LIST_HEAD(check_list);
1649 unsigned int channel;
1650 enum scsi_disposition rtn;
1653 * we really want to loop over the various channels, and do this on
1654 * a channel by channel basis. we should also check to see if any
1655 * of the failed commands are on soft_reset devices, and if so, skip
1659 for (channel = 0; channel <= shost->max_channel; channel++) {
1660 if (scsi_host_eh_past_deadline(shost)) {
1661 list_splice_init(&check_list, work_q);
1662 SCSI_LOG_ERROR_RECOVERY(3,
1663 shost_printk(KERN_INFO, shost,
1664 "%s: skip BRST, past eh deadline\n",
1666 return list_empty(work_q);
1670 list_for_each_entry(scmd, work_q, eh_entry) {
1671 if (channel == scmd_channel(scmd)) {
1675 * FIXME add back in some support for
1676 * soft_reset devices.
1683 SCSI_LOG_ERROR_RECOVERY(3,
1684 shost_printk(KERN_INFO, shost,
1685 "%s: Sending BRST chan: %d\n",
1686 current->comm, channel));
1687 rtn = scsi_try_bus_reset(chan_scmd);
1688 if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
1689 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1690 if (channel == scmd_channel(scmd)) {
1691 if (rtn == FAST_IO_FAIL)
1692 scsi_eh_finish_cmd(scmd,
1695 list_move_tail(&scmd->eh_entry,
1700 SCSI_LOG_ERROR_RECOVERY(3,
1701 shost_printk(KERN_INFO, shost,
1702 "%s: BRST failed chan: %d\n",
1703 current->comm, channel));
1706 return scsi_eh_test_devices(&check_list, work_q, done_q, 0);
1710 * scsi_eh_host_reset - send a host reset
1711 * @shost: host to be reset.
1712 * @work_q: &list_head for pending commands.
1713 * @done_q: &list_head for processed commands.
1715 static int scsi_eh_host_reset(struct Scsi_Host *shost,
1716 struct list_head *work_q,
1717 struct list_head *done_q)
1719 struct scsi_cmnd *scmd, *next;
1720 LIST_HEAD(check_list);
1721 enum scsi_disposition rtn;
1723 if (!list_empty(work_q)) {
1724 scmd = list_entry(work_q->next,
1725 struct scsi_cmnd, eh_entry);
1727 SCSI_LOG_ERROR_RECOVERY(3,
1728 shost_printk(KERN_INFO, shost,
1729 "%s: Sending HRST\n",
1732 rtn = scsi_try_host_reset(scmd);
1733 if (rtn == SUCCESS) {
1734 list_splice_init(work_q, &check_list);
1735 } else if (rtn == FAST_IO_FAIL) {
1736 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1737 scsi_eh_finish_cmd(scmd, done_q);
1740 SCSI_LOG_ERROR_RECOVERY(3,
1741 shost_printk(KERN_INFO, shost,
1742 "%s: HRST failed\n",
1746 return scsi_eh_test_devices(&check_list, work_q, done_q, 1);
1750 * scsi_eh_offline_sdevs - offline scsi devices that fail to recover
1751 * @work_q: &list_head for pending commands.
1752 * @done_q: &list_head for processed commands.
1754 static void scsi_eh_offline_sdevs(struct list_head *work_q,
1755 struct list_head *done_q)
1757 struct scsi_cmnd *scmd, *next;
1758 struct scsi_device *sdev;
1760 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1761 sdev_printk(KERN_INFO, scmd->device, "Device offlined - "
1762 "not ready after error recovery\n");
1763 sdev = scmd->device;
1765 mutex_lock(&sdev->state_mutex);
1766 scsi_device_set_state(sdev, SDEV_OFFLINE);
1767 mutex_unlock(&sdev->state_mutex);
1769 scsi_eh_finish_cmd(scmd, done_q);
1775 * scsi_noretry_cmd - determine if command should be failed fast
1776 * @scmd: SCSI cmd to examine.
1778 int scsi_noretry_cmd(struct scsi_cmnd *scmd)
1780 struct request *req = scsi_cmd_to_rq(scmd);
1782 switch (host_byte(scmd->result)) {
1788 return req->cmd_flags & REQ_FAILFAST_TRANSPORT;
1790 return req->cmd_flags & REQ_FAILFAST_DEV;
1792 if (get_status_byte(scmd) == SAM_STAT_RESERVATION_CONFLICT)
1795 case DID_SOFT_ERROR:
1796 return req->cmd_flags & REQ_FAILFAST_DRIVER;
1799 if (!scsi_status_is_check_condition(scmd->result))
1804 * assume caller has checked sense and determined
1805 * the check condition was retryable.
1807 if (req->cmd_flags & REQ_FAILFAST_DEV || blk_rq_is_passthrough(req))
1814 * scsi_decide_disposition - Disposition a cmd on return from LLD.
1815 * @scmd: SCSI cmd to examine.
1818 * This is *only* called when we are examining the status after sending
1819 * out the actual data command. any commands that are queued for error
1820 * recovery (e.g. test_unit_ready) do *not* come through here.
1822 * When this routine returns failed, it means the error handler thread
1823 * is woken. In cases where the error code indicates an error that
1824 * doesn't require the error handler read (i.e. we don't need to
1825 * abort/reset), this function should return SUCCESS.
1827 enum scsi_disposition scsi_decide_disposition(struct scsi_cmnd *scmd)
1829 enum scsi_disposition rtn;
1832 * if the device is offline, then we clearly just pass the result back
1833 * up to the top level.
1835 if (!scsi_device_online(scmd->device)) {
1836 SCSI_LOG_ERROR_RECOVERY(5, scmd_printk(KERN_INFO, scmd,
1837 "%s: device offline - report as SUCCESS\n", __func__));
1842 * first check the host byte, to see if there is anything in there
1843 * that would indicate what we need to do.
1845 switch (host_byte(scmd->result)) {
1846 case DID_PASSTHROUGH:
1848 * no matter what, pass this through to the upper layer.
1849 * nuke this special code so that it looks like we are saying
1852 scmd->result &= 0xff00ffff;
1856 * looks good. drop through, and check the next byte.
1860 if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) {
1861 set_host_byte(scmd, DID_TIME_OUT);
1865 case DID_NO_CONNECT:
1866 case DID_BAD_TARGET:
1868 * note - this means that we just report the status back
1869 * to the top level driver, not that we actually think
1870 * that it indicates SUCCESS.
1873 case DID_SOFT_ERROR:
1875 * when the low level driver returns did_soft_error,
1876 * it is responsible for keeping an internal retry counter
1877 * in order to avoid endless loops (db)
1884 return ADD_TO_MLQUEUE;
1885 case DID_TRANSPORT_DISRUPTED:
1887 * LLD/transport was disrupted during processing of the IO.
1888 * The transport class is now blocked/blocking,
1889 * and the transport will decide what to do with the IO
1890 * based on its timers and recovery capablilities if
1891 * there are enough retries.
1894 case DID_TRANSPORT_FAILFAST:
1896 * The transport decided to failfast the IO (most likely
1897 * the fast io fail tmo fired), so send IO directly upwards.
1900 case DID_TRANSPORT_MARGINAL:
1902 * caller has decided not to do retries on
1903 * abort success, so send IO directly upwards
1907 if (get_status_byte(scmd) == SAM_STAT_RESERVATION_CONFLICT)
1909 * execute reservation conflict processing code
1919 * when we scan the bus, we get timeout messages for
1920 * these commands if there is no device available.
1921 * other hosts report did_no_connect for the same thing.
1923 if ((scmd->cmnd[0] == TEST_UNIT_READY ||
1924 scmd->cmnd[0] == INQUIRY)) {
1936 * check the status byte to see if this indicates anything special.
1938 switch (get_status_byte(scmd)) {
1939 case SAM_STAT_TASK_SET_FULL:
1940 scsi_handle_queue_full(scmd->device);
1942 * the case of trying to send too many commands to a
1943 * tagged queueing device.
1948 * device can't talk to us at the moment. Should only
1949 * occur (SAM-3) when the task queue is empty, so will cause
1950 * the empty queue handling to trigger a stall in the
1953 return ADD_TO_MLQUEUE;
1955 if (scmd->cmnd[0] == REPORT_LUNS)
1956 scmd->device->sdev_target->expecting_lun_change = 0;
1957 scsi_handle_queue_ramp_up(scmd->device);
1959 case SAM_STAT_COMMAND_TERMINATED:
1961 case SAM_STAT_TASK_ABORTED:
1963 case SAM_STAT_CHECK_CONDITION:
1964 rtn = scsi_check_sense(scmd);
1965 if (rtn == NEEDS_RETRY)
1967 /* if rtn == FAILED, we have no sense information;
1968 * returning FAILED will wake the error handler thread
1969 * to collect the sense and redo the decide
1972 case SAM_STAT_CONDITION_MET:
1973 case SAM_STAT_INTERMEDIATE:
1974 case SAM_STAT_INTERMEDIATE_CONDITION_MET:
1975 case SAM_STAT_ACA_ACTIVE:
1977 * who knows? FIXME(eric)
1981 case SAM_STAT_RESERVATION_CONFLICT:
1982 sdev_printk(KERN_INFO, scmd->device,
1983 "reservation conflict\n");
1984 set_host_byte(scmd, DID_NEXUS_FAILURE);
1985 return SUCCESS; /* causes immediate i/o error */
1993 /* we requeue for retry because the error was retryable, and
1994 * the request was not marked fast fail. Note that above,
1995 * even if the request is marked fast fail, we still requeue
1996 * for queue congestion conditions (QUEUE_FULL or BUSY) */
1997 if (scsi_cmd_retry_allowed(scmd) && !scsi_noretry_cmd(scmd)) {
2001 * no more retries - report this one back to upper level.
2007 static void eh_lock_door_done(struct request *req, blk_status_t status)
2009 blk_mq_free_request(req);
2013 * scsi_eh_lock_door - Prevent medium removal for the specified device
2014 * @sdev: SCSI device to prevent medium removal
2017 * We must be called from process context.
2020 * We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the
2021 * head of the devices request queue, and continue.
2023 static void scsi_eh_lock_door(struct scsi_device *sdev)
2025 struct request *req;
2026 struct scsi_request *rq;
2028 req = scsi_alloc_request(sdev->request_queue, REQ_OP_DRV_IN, 0);
2033 rq->cmd[0] = ALLOW_MEDIUM_REMOVAL;
2037 rq->cmd[4] = SCSI_REMOVAL_PREVENT;
2039 rq->cmd_len = COMMAND_SIZE(rq->cmd[0]);
2041 req->rq_flags |= RQF_QUIET;
2042 req->timeout = 10 * HZ;
2045 blk_execute_rq_nowait(req, true, eh_lock_door_done);
2049 * scsi_restart_operations - restart io operations to the specified host.
2050 * @shost: Host we are restarting.
2053 * When we entered the error handler, we blocked all further i/o to
2054 * this device. we need to 'reverse' this process.
2056 static void scsi_restart_operations(struct Scsi_Host *shost)
2058 struct scsi_device *sdev;
2059 unsigned long flags;
2062 * If the door was locked, we need to insert a door lock request
2063 * onto the head of the SCSI request queue for the device. There
2064 * is no point trying to lock the door of an off-line device.
2066 shost_for_each_device(sdev, shost) {
2067 if (scsi_device_online(sdev) && sdev->was_reset && sdev->locked) {
2068 scsi_eh_lock_door(sdev);
2069 sdev->was_reset = 0;
2074 * next free up anything directly waiting upon the host. this
2075 * will be requests for character device operations, and also for
2076 * ioctls to queued block devices.
2078 SCSI_LOG_ERROR_RECOVERY(3,
2079 shost_printk(KERN_INFO, shost, "waking up host to restart\n"));
2081 spin_lock_irqsave(shost->host_lock, flags);
2082 if (scsi_host_set_state(shost, SHOST_RUNNING))
2083 if (scsi_host_set_state(shost, SHOST_CANCEL))
2084 BUG_ON(scsi_host_set_state(shost, SHOST_DEL));
2085 spin_unlock_irqrestore(shost->host_lock, flags);
2087 wake_up(&shost->host_wait);
2090 * finally we need to re-initiate requests that may be pending. we will
2091 * have had everything blocked while error handling is taking place, and
2092 * now that error recovery is done, we will need to ensure that these
2093 * requests are started.
2095 scsi_run_host_queues(shost);
2098 * if eh is active and host_eh_scheduled is pending we need to re-run
2099 * recovery. we do this check after scsi_run_host_queues() to allow
2100 * everything pent up since the last eh run a chance to make forward
2101 * progress before we sync again. Either we'll immediately re-run
2102 * recovery or scsi_device_unbusy() will wake us again when these
2103 * pending commands complete.
2105 spin_lock_irqsave(shost->host_lock, flags);
2106 if (shost->host_eh_scheduled)
2107 if (scsi_host_set_state(shost, SHOST_RECOVERY))
2108 WARN_ON(scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY));
2109 spin_unlock_irqrestore(shost->host_lock, flags);
2113 * scsi_eh_ready_devs - check device ready state and recover if not.
2114 * @shost: host to be recovered.
2115 * @work_q: &list_head for pending commands.
2116 * @done_q: &list_head for processed commands.
2118 void scsi_eh_ready_devs(struct Scsi_Host *shost,
2119 struct list_head *work_q,
2120 struct list_head *done_q)
2122 if (!scsi_eh_stu(shost, work_q, done_q))
2123 if (!scsi_eh_bus_device_reset(shost, work_q, done_q))
2124 if (!scsi_eh_target_reset(shost, work_q, done_q))
2125 if (!scsi_eh_bus_reset(shost, work_q, done_q))
2126 if (!scsi_eh_host_reset(shost, work_q, done_q))
2127 scsi_eh_offline_sdevs(work_q,
2130 EXPORT_SYMBOL_GPL(scsi_eh_ready_devs);
2133 * scsi_eh_flush_done_q - finish processed commands or retry them.
2134 * @done_q: list_head of processed commands.
2136 void scsi_eh_flush_done_q(struct list_head *done_q)
2138 struct scsi_cmnd *scmd, *next;
2140 list_for_each_entry_safe(scmd, next, done_q, eh_entry) {
2141 list_del_init(&scmd->eh_entry);
2142 if (scsi_device_online(scmd->device) &&
2143 !scsi_noretry_cmd(scmd) && scsi_cmd_retry_allowed(scmd) &&
2144 scsi_eh_should_retry_cmd(scmd)) {
2145 SCSI_LOG_ERROR_RECOVERY(3,
2146 scmd_printk(KERN_INFO, scmd,
2147 "%s: flush retry cmd\n",
2149 scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY);
2152 * If just we got sense for the device (called
2153 * scsi_eh_get_sense), scmd->result is already
2154 * set, do not set DID_TIME_OUT.
2157 scmd->result |= (DID_TIME_OUT << 16);
2158 SCSI_LOG_ERROR_RECOVERY(3,
2159 scmd_printk(KERN_INFO, scmd,
2160 "%s: flush finish cmd\n",
2162 scsi_finish_command(scmd);
2166 EXPORT_SYMBOL(scsi_eh_flush_done_q);
2169 * scsi_unjam_host - Attempt to fix a host which has a cmd that failed.
2170 * @shost: Host to unjam.
2173 * When we come in here, we *know* that all commands on the bus have
2174 * either completed, failed or timed out. we also know that no further
2175 * commands are being sent to the host, so things are relatively quiet
2176 * and we have freedom to fiddle with things as we wish.
2178 * This is only the *default* implementation. it is possible for
2179 * individual drivers to supply their own version of this function, and
2180 * if the maintainer wishes to do this, it is strongly suggested that
2181 * this function be taken as a template and modified. this function
2182 * was designed to correctly handle problems for about 95% of the
2183 * different cases out there, and it should always provide at least a
2184 * reasonable amount of error recovery.
2186 * Any command marked 'failed' or 'timeout' must eventually have
2187 * scsi_finish_cmd() called for it. we do all of the retry stuff
2188 * here, so when we restart the host after we return it should have an
2191 static void scsi_unjam_host(struct Scsi_Host *shost)
2193 unsigned long flags;
2194 LIST_HEAD(eh_work_q);
2195 LIST_HEAD(eh_done_q);
2197 spin_lock_irqsave(shost->host_lock, flags);
2198 list_splice_init(&shost->eh_cmd_q, &eh_work_q);
2199 spin_unlock_irqrestore(shost->host_lock, flags);
2201 SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(shost, &eh_work_q));
2203 if (!scsi_eh_get_sense(&eh_work_q, &eh_done_q))
2204 scsi_eh_ready_devs(shost, &eh_work_q, &eh_done_q);
2206 spin_lock_irqsave(shost->host_lock, flags);
2207 if (shost->eh_deadline != -1)
2208 shost->last_reset = 0;
2209 spin_unlock_irqrestore(shost->host_lock, flags);
2210 scsi_eh_flush_done_q(&eh_done_q);
2214 * scsi_error_handler - SCSI error handler thread
2215 * @data: Host for which we are running.
2218 * This is the main error handling loop. This is run as a kernel thread
2219 * for every SCSI host and handles all error handling activity.
2221 int scsi_error_handler(void *data)
2223 struct Scsi_Host *shost = data;
2226 * We use TASK_INTERRUPTIBLE so that the thread is not
2227 * counted against the load average as a running process.
2228 * We never actually get interrupted because kthread_run
2229 * disables signal delivery for the created thread.
2233 * The sequence in kthread_stop() sets the stop flag first
2234 * then wakes the process. To avoid missed wakeups, the task
2235 * should always be in a non running state before the stop
2238 set_current_state(TASK_INTERRUPTIBLE);
2239 if (kthread_should_stop())
2242 if ((shost->host_failed == 0 && shost->host_eh_scheduled == 0) ||
2243 shost->host_failed != scsi_host_busy(shost)) {
2244 SCSI_LOG_ERROR_RECOVERY(1,
2245 shost_printk(KERN_INFO, shost,
2246 "scsi_eh_%d: sleeping\n",
2252 __set_current_state(TASK_RUNNING);
2253 SCSI_LOG_ERROR_RECOVERY(1,
2254 shost_printk(KERN_INFO, shost,
2255 "scsi_eh_%d: waking up %d/%d/%d\n",
2256 shost->host_no, shost->host_eh_scheduled,
2258 scsi_host_busy(shost)));
2261 * We have a host that is failing for some reason. Figure out
2262 * what we need to do to get it up and online again (if we can).
2263 * If we fail, we end up taking the thing offline.
2265 if (!shost->eh_noresume && scsi_autopm_get_host(shost) != 0) {
2266 SCSI_LOG_ERROR_RECOVERY(1,
2267 shost_printk(KERN_ERR, shost,
2268 "scsi_eh_%d: unable to autoresume\n",
2273 if (shost->transportt->eh_strategy_handler)
2274 shost->transportt->eh_strategy_handler(shost);
2276 scsi_unjam_host(shost);
2278 /* All scmds have been handled */
2279 shost->host_failed = 0;
2282 * Note - if the above fails completely, the action is to take
2283 * individual devices offline and flush the queue of any
2284 * outstanding requests that may have been pending. When we
2285 * restart, we restart any I/O to any other devices on the bus
2286 * which are still online.
2288 scsi_restart_operations(shost);
2289 if (!shost->eh_noresume)
2290 scsi_autopm_put_host(shost);
2292 __set_current_state(TASK_RUNNING);
2294 SCSI_LOG_ERROR_RECOVERY(1,
2295 shost_printk(KERN_INFO, shost,
2296 "Error handler scsi_eh_%d exiting\n",
2298 shost->ehandler = NULL;
2303 * Function: scsi_report_bus_reset()
2305 * Purpose: Utility function used by low-level drivers to report that
2306 * they have observed a bus reset on the bus being handled.
2308 * Arguments: shost - Host in question
2309 * channel - channel on which reset was observed.
2313 * Lock status: Host lock must be held.
2315 * Notes: This only needs to be called if the reset is one which
2316 * originates from an unknown location. Resets originated
2317 * by the mid-level itself don't need to call this, but there
2318 * should be no harm.
2320 * The main purpose of this is to make sure that a CHECK_CONDITION
2321 * is properly treated.
2323 void scsi_report_bus_reset(struct Scsi_Host *shost, int channel)
2325 struct scsi_device *sdev;
2327 __shost_for_each_device(sdev, shost) {
2328 if (channel == sdev_channel(sdev))
2329 __scsi_report_device_reset(sdev, NULL);
2332 EXPORT_SYMBOL(scsi_report_bus_reset);
2335 * Function: scsi_report_device_reset()
2337 * Purpose: Utility function used by low-level drivers to report that
2338 * they have observed a device reset on the device being handled.
2340 * Arguments: shost - Host in question
2341 * channel - channel on which reset was observed
2342 * target - target on which reset was observed
2346 * Lock status: Host lock must be held
2348 * Notes: This only needs to be called if the reset is one which
2349 * originates from an unknown location. Resets originated
2350 * by the mid-level itself don't need to call this, but there
2351 * should be no harm.
2353 * The main purpose of this is to make sure that a CHECK_CONDITION
2354 * is properly treated.
2356 void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
2358 struct scsi_device *sdev;
2360 __shost_for_each_device(sdev, shost) {
2361 if (channel == sdev_channel(sdev) &&
2362 target == sdev_id(sdev))
2363 __scsi_report_device_reset(sdev, NULL);
2366 EXPORT_SYMBOL(scsi_report_device_reset);
2369 * scsi_ioctl_reset: explicitly reset a host/bus/target/device
2370 * @dev: scsi_device to operate on
2371 * @arg: reset type (see sg.h)
2374 scsi_ioctl_reset(struct scsi_device *dev, int __user *arg)
2376 struct scsi_cmnd *scmd;
2377 struct Scsi_Host *shost = dev->host;
2379 unsigned long flags;
2381 enum scsi_disposition rtn;
2383 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2386 error = get_user(val, arg);
2390 if (scsi_autopm_get_host(shost) < 0)
2394 rq = kzalloc(sizeof(struct request) + sizeof(struct scsi_cmnd) +
2395 shost->hostt->cmd_size, GFP_KERNEL);
2397 goto out_put_autopm_host;
2398 blk_rq_init(NULL, rq);
2400 scmd = (struct scsi_cmnd *)(rq + 1);
2401 scsi_init_command(dev, scmd);
2402 scmd->cmnd = scsi_req(rq)->cmd;
2404 scmd->submitter = SUBMITTED_BY_SCSI_RESET_IOCTL;
2405 memset(&scmd->sdb, 0, sizeof(scmd->sdb));
2409 scmd->sc_data_direction = DMA_BIDIRECTIONAL;
2411 spin_lock_irqsave(shost->host_lock, flags);
2412 shost->tmf_in_progress = 1;
2413 spin_unlock_irqrestore(shost->host_lock, flags);
2415 switch (val & ~SG_SCSI_RESET_NO_ESCALATE) {
2416 case SG_SCSI_RESET_NOTHING:
2419 case SG_SCSI_RESET_DEVICE:
2420 rtn = scsi_try_bus_device_reset(scmd);
2421 if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE))
2424 case SG_SCSI_RESET_TARGET:
2425 rtn = scsi_try_target_reset(scmd);
2426 if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE))
2429 case SG_SCSI_RESET_BUS:
2430 rtn = scsi_try_bus_reset(scmd);
2431 if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE))
2434 case SG_SCSI_RESET_HOST:
2435 rtn = scsi_try_host_reset(scmd);
2444 error = (rtn == SUCCESS) ? 0 : -EIO;
2446 spin_lock_irqsave(shost->host_lock, flags);
2447 shost->tmf_in_progress = 0;
2448 spin_unlock_irqrestore(shost->host_lock, flags);
2451 * be sure to wake up anyone who was sleeping or had their queue
2452 * suspended while we performed the TMF.
2454 SCSI_LOG_ERROR_RECOVERY(3,
2455 shost_printk(KERN_INFO, shost,
2456 "waking up host to restart after TMF\n"));
2458 wake_up(&shost->host_wait);
2459 scsi_run_host_queues(shost);
2463 out_put_autopm_host:
2464 scsi_autopm_put_host(shost);
2468 bool scsi_command_normalize_sense(const struct scsi_cmnd *cmd,
2469 struct scsi_sense_hdr *sshdr)
2471 return scsi_normalize_sense(cmd->sense_buffer,
2472 SCSI_SENSE_BUFFERSIZE, sshdr);
2474 EXPORT_SYMBOL(scsi_command_normalize_sense);
2477 * scsi_get_sense_info_fld - get information field from sense data (either fixed or descriptor format)
2478 * @sense_buffer: byte array of sense data
2479 * @sb_len: number of valid bytes in sense_buffer
2480 * @info_out: pointer to 64 integer where 8 or 4 byte information
2481 * field will be placed if found.
2484 * true if information field found, false if not found.
2486 bool scsi_get_sense_info_fld(const u8 *sense_buffer, int sb_len,
2493 switch (sense_buffer[0] & 0x7f) {
2496 if (sense_buffer[0] & 0x80) {
2497 *info_out = get_unaligned_be32(&sense_buffer[3]);
2503 ucp = scsi_sense_desc_find(sense_buffer, sb_len,
2505 if (ucp && (0xa == ucp[1])) {
2506 *info_out = get_unaligned_be64(&ucp[4]);
2514 EXPORT_SYMBOL(scsi_get_sense_info_fld);