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_timeout(), 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 (!shost->hostt->eh_abort_handler) {
235 /* No abort handler, fail command directly */
239 if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) {
241 * Retry after abort failed, escalate to next level.
243 SCSI_LOG_ERROR_RECOVERY(3,
244 scmd_printk(KERN_INFO, scmd,
245 "previous abort failed\n"));
246 BUG_ON(delayed_work_pending(&scmd->abort_work));
250 spin_lock_irqsave(shost->host_lock, flags);
251 if (shost->eh_deadline != -1 && !shost->last_reset)
252 shost->last_reset = jiffies;
253 BUG_ON(!list_empty(&scmd->eh_entry));
254 list_add_tail(&scmd->eh_entry, &shost->eh_abort_list);
255 spin_unlock_irqrestore(shost->host_lock, flags);
257 scmd->eh_eflags |= SCSI_EH_ABORT_SCHEDULED;
258 SCSI_LOG_ERROR_RECOVERY(3,
259 scmd_printk(KERN_INFO, scmd, "abort scheduled\n"));
260 queue_delayed_work(shost->tmf_work_q, &scmd->abort_work, HZ / 100);
265 * scsi_eh_reset - call into ->eh_action to reset internal counters
266 * @scmd: scmd to run eh on.
268 * The scsi driver might be carrying internal state about the
269 * devices, so we need to call into the driver to reset the
270 * internal state once the error handler is started.
272 static void scsi_eh_reset(struct scsi_cmnd *scmd)
274 if (!blk_rq_is_passthrough(scsi_cmd_to_rq(scmd))) {
275 struct scsi_driver *sdrv = scsi_cmd_to_driver(scmd);
277 sdrv->eh_reset(scmd);
281 static void scsi_eh_inc_host_failed(struct rcu_head *head)
283 struct scsi_cmnd *scmd = container_of(head, typeof(*scmd), rcu);
284 struct Scsi_Host *shost = scmd->device->host;
287 spin_lock_irqsave(shost->host_lock, flags);
288 shost->host_failed++;
289 scsi_eh_wakeup(shost);
290 spin_unlock_irqrestore(shost->host_lock, flags);
294 * scsi_eh_scmd_add - add scsi cmd to error handling.
295 * @scmd: scmd to run eh on.
297 void scsi_eh_scmd_add(struct scsi_cmnd *scmd)
299 struct Scsi_Host *shost = scmd->device->host;
303 WARN_ON_ONCE(!shost->ehandler);
305 spin_lock_irqsave(shost->host_lock, flags);
306 if (scsi_host_set_state(shost, SHOST_RECOVERY)) {
307 ret = scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY);
310 if (shost->eh_deadline != -1 && !shost->last_reset)
311 shost->last_reset = jiffies;
314 list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q);
315 spin_unlock_irqrestore(shost->host_lock, flags);
317 * Ensure that all tasks observe the host state change before the
318 * host_failed change.
320 call_rcu_hurry(&scmd->rcu, scsi_eh_inc_host_failed);
324 * scsi_timeout - Timeout function for normal scsi commands.
325 * @req: request that is timing out.
328 * We do not need to lock this. There is the potential for a race
329 * only in that the normal completion handling might run, but if the
330 * normal completion function determines that the timer has already
331 * fired, then it mustn't do anything.
333 enum blk_eh_timer_return scsi_timeout(struct request *req)
335 struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(req);
336 struct Scsi_Host *host = scmd->device->host;
338 trace_scsi_dispatch_cmd_timeout(scmd);
339 scsi_log_completion(scmd, TIMEOUT_ERROR);
341 atomic_inc(&scmd->device->iotmo_cnt);
342 if (host->eh_deadline != -1 && !host->last_reset)
343 host->last_reset = jiffies;
345 if (host->hostt->eh_timed_out) {
346 switch (host->hostt->eh_timed_out(scmd)) {
349 case SCSI_EH_RESET_TIMER:
350 return BLK_EH_RESET_TIMER;
351 case SCSI_EH_NOT_HANDLED:
357 * If scsi_done() has already set SCMD_STATE_COMPLETE, do not modify
360 if (test_and_set_bit(SCMD_STATE_COMPLETE, &scmd->state))
362 atomic_inc(&scmd->device->iodone_cnt);
363 if (scsi_abort_command(scmd) != SUCCESS) {
364 set_host_byte(scmd, DID_TIME_OUT);
365 scsi_eh_scmd_add(scmd);
372 * scsi_block_when_processing_errors - Prevent cmds from being queued.
373 * @sdev: Device on which we are performing recovery.
376 * We block until the host is out of error recovery, and then check to
377 * see whether the host or the device is offline.
380 * 0 when dev was taken offline by error recovery. 1 OK to proceed.
382 int scsi_block_when_processing_errors(struct scsi_device *sdev)
386 wait_event(sdev->host->host_wait, !scsi_host_in_recovery(sdev->host));
388 online = scsi_device_online(sdev);
392 EXPORT_SYMBOL(scsi_block_when_processing_errors);
394 #ifdef CONFIG_SCSI_LOGGING
396 * scsi_eh_prt_fail_stats - Log info on failures.
397 * @shost: scsi host being recovered.
398 * @work_q: Queue of scsi cmds to process.
400 static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost,
401 struct list_head *work_q)
403 struct scsi_cmnd *scmd;
404 struct scsi_device *sdev;
405 int total_failures = 0;
408 int devices_failed = 0;
410 shost_for_each_device(sdev, shost) {
411 list_for_each_entry(scmd, work_q, eh_entry) {
412 if (scmd->device == sdev) {
414 if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED)
421 if (cmd_cancel || cmd_failed) {
422 SCSI_LOG_ERROR_RECOVERY(3,
423 shost_printk(KERN_INFO, shost,
424 "%s: cmds failed: %d, cancel: %d\n",
425 __func__, cmd_failed,
433 SCSI_LOG_ERROR_RECOVERY(2, shost_printk(KERN_INFO, shost,
434 "Total of %d commands on %d"
435 " devices require eh work\n",
436 total_failures, devices_failed));
441 * scsi_report_lun_change - Set flag on all *other* devices on the same target
442 * to indicate that a UNIT ATTENTION is expected.
443 * @sdev: Device reporting the UNIT ATTENTION
445 static void scsi_report_lun_change(struct scsi_device *sdev)
447 sdev->sdev_target->expecting_lun_change = 1;
451 * scsi_report_sense - Examine scsi sense information and log messages for
452 * certain conditions, also issue uevents for some of them.
453 * @sdev: Device reporting the sense code
454 * @sshdr: sshdr to be examined
456 static void scsi_report_sense(struct scsi_device *sdev,
457 struct scsi_sense_hdr *sshdr)
459 enum scsi_device_event evt_type = SDEV_EVT_MAXBITS; /* i.e. none */
461 if (sshdr->sense_key == UNIT_ATTENTION) {
462 if (sshdr->asc == 0x3f && sshdr->ascq == 0x03) {
463 evt_type = SDEV_EVT_INQUIRY_CHANGE_REPORTED;
464 sdev_printk(KERN_WARNING, sdev,
465 "Inquiry data has changed");
466 } else if (sshdr->asc == 0x3f && sshdr->ascq == 0x0e) {
467 evt_type = SDEV_EVT_LUN_CHANGE_REPORTED;
468 scsi_report_lun_change(sdev);
469 sdev_printk(KERN_WARNING, sdev,
470 "LUN assignments on this target have "
471 "changed. The Linux SCSI layer does not "
472 "automatically remap LUN assignments.\n");
473 } else if (sshdr->asc == 0x3f)
474 sdev_printk(KERN_WARNING, sdev,
475 "Operating parameters on this target have "
476 "changed. The Linux SCSI layer does not "
477 "automatically adjust these parameters.\n");
479 if (sshdr->asc == 0x38 && sshdr->ascq == 0x07) {
480 evt_type = SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED;
481 sdev_printk(KERN_WARNING, sdev,
482 "Warning! Received an indication that the "
483 "LUN reached a thin provisioning soft "
487 if (sshdr->asc == 0x29) {
488 evt_type = SDEV_EVT_POWER_ON_RESET_OCCURRED;
490 * Do not print message if it is an expected side-effect
493 if (!sdev->silence_suspend)
494 sdev_printk(KERN_WARNING, sdev,
495 "Power-on or device reset occurred\n");
498 if (sshdr->asc == 0x2a && sshdr->ascq == 0x01) {
499 evt_type = SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED;
500 sdev_printk(KERN_WARNING, sdev,
501 "Mode parameters changed");
502 } else if (sshdr->asc == 0x2a && sshdr->ascq == 0x06) {
503 evt_type = SDEV_EVT_ALUA_STATE_CHANGE_REPORTED;
504 sdev_printk(KERN_WARNING, sdev,
505 "Asymmetric access state changed");
506 } else if (sshdr->asc == 0x2a && sshdr->ascq == 0x09) {
507 evt_type = SDEV_EVT_CAPACITY_CHANGE_REPORTED;
508 sdev_printk(KERN_WARNING, sdev,
509 "Capacity data has changed");
510 } else if (sshdr->asc == 0x2a)
511 sdev_printk(KERN_WARNING, sdev,
512 "Parameters changed");
515 if (evt_type != SDEV_EVT_MAXBITS) {
516 set_bit(evt_type, sdev->pending_events);
517 schedule_work(&sdev->event_work);
521 static inline void set_scsi_ml_byte(struct scsi_cmnd *cmd, u8 status)
523 cmd->result = (cmd->result & 0xffff00ff) | (status << 8);
527 * scsi_check_sense - Examine scsi cmd sense
528 * @scmd: Cmd to have sense checked.
531 * SUCCESS or FAILED or NEEDS_RETRY or ADD_TO_MLQUEUE
534 * When a deferred error is detected the current command has
535 * not been executed and needs retrying.
537 enum scsi_disposition scsi_check_sense(struct scsi_cmnd *scmd)
539 struct scsi_device *sdev = scmd->device;
540 struct scsi_sense_hdr sshdr;
542 if (! scsi_command_normalize_sense(scmd, &sshdr))
543 return FAILED; /* no valid sense data */
545 scsi_report_sense(sdev, &sshdr);
547 if (scsi_sense_is_deferred(&sshdr))
550 if (sdev->handler && sdev->handler->check_sense) {
551 enum scsi_disposition rc;
553 rc = sdev->handler->check_sense(sdev, &sshdr);
554 if (rc != SCSI_RETURN_NOT_HANDLED)
556 /* handler does not care. Drop down to default handling */
559 if (scmd->cmnd[0] == TEST_UNIT_READY &&
560 scmd->submitter != SUBMITTED_BY_SCSI_ERROR_HANDLER)
562 * nasty: for mid-layer issued TURs, we need to return the
563 * actual sense data without any recovery attempt. For eh
564 * issued ones, we need to try to recover and interpret
569 * Previous logic looked for FILEMARK, EOM or ILI which are
570 * mainly associated with tapes and returned SUCCESS.
572 if (sshdr.response_code == 0x70) {
574 if (scmd->sense_buffer[2] & 0xe0)
578 * descriptor format: look for "stream commands sense data
579 * descriptor" (see SSC-3). Assume single sense data
580 * descriptor. Ignore ILI from SBC-2 READ LONG and WRITE LONG.
582 if ((sshdr.additional_length > 3) &&
583 (scmd->sense_buffer[8] == 0x4) &&
584 (scmd->sense_buffer[11] & 0xe0))
588 switch (sshdr.sense_key) {
591 case RECOVERED_ERROR:
592 return /* soft_error */ SUCCESS;
594 case ABORTED_COMMAND:
595 if (sshdr.asc == 0x10) /* DIF */
598 if (sshdr.asc == 0x44 && sdev->sdev_bflags & BLIST_RETRY_ITF)
599 return ADD_TO_MLQUEUE;
600 if (sshdr.asc == 0xc1 && sshdr.ascq == 0x01 &&
601 sdev->sdev_bflags & BLIST_RETRY_ASC_C1)
602 return ADD_TO_MLQUEUE;
608 * if we are expecting a cc/ua because of a bus reset that we
609 * performed, treat this just as a retry. otherwise this is
610 * information that we should pass up to the upper-level driver
611 * so that we can deal with it there.
613 if (scmd->device->expecting_cc_ua) {
615 * Because some device does not queue unit
616 * attentions correctly, we carefully check
617 * additional sense code and qualifier so as
618 * not to squash media change unit attention.
620 if (sshdr.asc != 0x28 || sshdr.ascq != 0x00) {
621 scmd->device->expecting_cc_ua = 0;
626 * we might also expect a cc/ua if another LUN on the target
627 * reported a UA with an ASC/ASCQ of 3F 0E -
628 * REPORTED LUNS DATA HAS CHANGED.
630 if (scmd->device->sdev_target->expecting_lun_change &&
631 sshdr.asc == 0x3f && sshdr.ascq == 0x0e)
634 * if the device is in the process of becoming ready, we
637 if ((sshdr.asc == 0x04) && (sshdr.ascq == 0x01))
640 * if the device is not started, we need to wake
641 * the error handler to start the motor
643 if (scmd->device->allow_restart &&
644 (sshdr.asc == 0x04) && (sshdr.ascq == 0x02))
647 * Pass the UA upwards for a determination in the completion
652 /* these are not supported */
654 if (sshdr.asc == 0x27 && sshdr.ascq == 0x07) {
655 /* Thin provisioning hard threshold reached */
656 set_scsi_ml_byte(scmd, SCSIML_STAT_NOSPC);
661 case VOLUME_OVERFLOW:
664 set_scsi_ml_byte(scmd, SCSIML_STAT_TGT_FAILURE);
668 if (sshdr.asc == 0x11 || /* UNRECOVERED READ ERR */
669 sshdr.asc == 0x13 || /* AMNF DATA FIELD */
670 sshdr.asc == 0x14) { /* RECORD NOT FOUND */
671 set_scsi_ml_byte(scmd, SCSIML_STAT_MED_ERROR);
677 if (scmd->device->retry_hwerror)
678 return ADD_TO_MLQUEUE;
680 set_scsi_ml_byte(scmd, SCSIML_STAT_TGT_FAILURE);
683 case ILLEGAL_REQUEST:
684 if (sshdr.asc == 0x20 || /* Invalid command operation code */
685 sshdr.asc == 0x21 || /* Logical block address out of range */
686 sshdr.asc == 0x22 || /* Invalid function */
687 sshdr.asc == 0x24 || /* Invalid field in cdb */
688 sshdr.asc == 0x26 || /* Parameter value invalid */
689 sshdr.asc == 0x27) { /* Write protected */
690 set_scsi_ml_byte(scmd, SCSIML_STAT_TGT_FAILURE);
698 EXPORT_SYMBOL_GPL(scsi_check_sense);
700 static void scsi_handle_queue_ramp_up(struct scsi_device *sdev)
702 struct scsi_host_template *sht = sdev->host->hostt;
703 struct scsi_device *tmp_sdev;
705 if (!sht->track_queue_depth ||
706 sdev->queue_depth >= sdev->max_queue_depth)
709 if (time_before(jiffies,
710 sdev->last_queue_ramp_up + sdev->queue_ramp_up_period))
713 if (time_before(jiffies,
714 sdev->last_queue_full_time + sdev->queue_ramp_up_period))
718 * Walk all devices of a target and do
721 shost_for_each_device(tmp_sdev, sdev->host) {
722 if (tmp_sdev->channel != sdev->channel ||
723 tmp_sdev->id != sdev->id ||
724 tmp_sdev->queue_depth == sdev->max_queue_depth)
727 scsi_change_queue_depth(tmp_sdev, tmp_sdev->queue_depth + 1);
728 sdev->last_queue_ramp_up = jiffies;
732 static void scsi_handle_queue_full(struct scsi_device *sdev)
734 struct scsi_host_template *sht = sdev->host->hostt;
735 struct scsi_device *tmp_sdev;
737 if (!sht->track_queue_depth)
740 shost_for_each_device(tmp_sdev, sdev->host) {
741 if (tmp_sdev->channel != sdev->channel ||
742 tmp_sdev->id != sdev->id)
745 * We do not know the number of commands that were at
746 * the device when we got the queue full so we start
747 * from the highest possible value and work our way down.
749 scsi_track_queue_full(tmp_sdev, tmp_sdev->queue_depth - 1);
754 * scsi_eh_completed_normally - Disposition a eh cmd on return from LLD.
755 * @scmd: SCSI cmd to examine.
758 * This is *only* called when we are examining the status of commands
759 * queued during error recovery. the main difference here is that we
760 * don't allow for the possibility of retries here, and we are a lot
761 * more restrictive about what we consider acceptable.
763 static enum scsi_disposition scsi_eh_completed_normally(struct scsi_cmnd *scmd)
766 * first check the host byte, to see if there is anything in there
767 * that would indicate what we need to do.
769 if (host_byte(scmd->result) == DID_RESET) {
771 * rats. we are already in the error handler, so we now
772 * get to try and figure out what to do next. if the sense
773 * is valid, we have a pretty good idea of what to do.
774 * if not, we mark it as FAILED.
776 return scsi_check_sense(scmd);
778 if (host_byte(scmd->result) != DID_OK)
782 * now, check the status byte to see if this indicates
785 switch (get_status_byte(scmd)) {
787 scsi_handle_queue_ramp_up(scmd->device);
789 case SAM_STAT_COMMAND_TERMINATED:
791 case SAM_STAT_CHECK_CONDITION:
792 return scsi_check_sense(scmd);
793 case SAM_STAT_CONDITION_MET:
794 case SAM_STAT_INTERMEDIATE:
795 case SAM_STAT_INTERMEDIATE_CONDITION_MET:
797 * who knows? FIXME(eric)
800 case SAM_STAT_RESERVATION_CONFLICT:
801 if (scmd->cmnd[0] == TEST_UNIT_READY)
802 /* it is a success, we probed the device and
805 /* otherwise, we failed to send the command */
807 case SAM_STAT_TASK_SET_FULL:
808 scsi_handle_queue_full(scmd->device);
819 * scsi_eh_done - Completion function for error handling.
820 * @scmd: Cmd that is done.
822 void scsi_eh_done(struct scsi_cmnd *scmd)
824 struct completion *eh_action;
826 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
827 "%s result: %x\n", __func__, scmd->result));
829 eh_action = scmd->device->host->eh_action;
835 * scsi_try_host_reset - ask host adapter to reset itself
836 * @scmd: SCSI cmd to send host reset.
838 static enum scsi_disposition scsi_try_host_reset(struct scsi_cmnd *scmd)
841 enum scsi_disposition rtn;
842 struct Scsi_Host *host = scmd->device->host;
843 struct scsi_host_template *hostt = host->hostt;
845 SCSI_LOG_ERROR_RECOVERY(3,
846 shost_printk(KERN_INFO, host, "Snd Host RST\n"));
848 if (!hostt->eh_host_reset_handler)
851 rtn = hostt->eh_host_reset_handler(scmd);
853 if (rtn == SUCCESS) {
854 if (!hostt->skip_settle_delay)
855 ssleep(HOST_RESET_SETTLE_TIME);
856 spin_lock_irqsave(host->host_lock, flags);
857 scsi_report_bus_reset(host, scmd_channel(scmd));
858 spin_unlock_irqrestore(host->host_lock, flags);
865 * scsi_try_bus_reset - ask host to perform a bus reset
866 * @scmd: SCSI cmd to send bus reset.
868 static enum scsi_disposition scsi_try_bus_reset(struct scsi_cmnd *scmd)
871 enum scsi_disposition rtn;
872 struct Scsi_Host *host = scmd->device->host;
873 struct scsi_host_template *hostt = host->hostt;
875 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
876 "%s: Snd Bus RST\n", __func__));
878 if (!hostt->eh_bus_reset_handler)
881 rtn = hostt->eh_bus_reset_handler(scmd);
883 if (rtn == SUCCESS) {
884 if (!hostt->skip_settle_delay)
885 ssleep(BUS_RESET_SETTLE_TIME);
886 spin_lock_irqsave(host->host_lock, flags);
887 scsi_report_bus_reset(host, scmd_channel(scmd));
888 spin_unlock_irqrestore(host->host_lock, flags);
894 static void __scsi_report_device_reset(struct scsi_device *sdev, void *data)
897 sdev->expecting_cc_ua = 1;
901 * scsi_try_target_reset - Ask host to perform a target reset
902 * @scmd: SCSI cmd used to send a target reset
905 * There is no timeout for this operation. if this operation is
906 * unreliable for a given host, then the host itself needs to put a
907 * timer on it, and set the host back to a consistent state prior to
910 static enum scsi_disposition scsi_try_target_reset(struct scsi_cmnd *scmd)
913 enum scsi_disposition rtn;
914 struct Scsi_Host *host = scmd->device->host;
915 struct scsi_host_template *hostt = host->hostt;
917 if (!hostt->eh_target_reset_handler)
920 rtn = hostt->eh_target_reset_handler(scmd);
921 if (rtn == SUCCESS) {
922 spin_lock_irqsave(host->host_lock, flags);
923 __starget_for_each_device(scsi_target(scmd->device), NULL,
924 __scsi_report_device_reset);
925 spin_unlock_irqrestore(host->host_lock, flags);
932 * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev
933 * @scmd: SCSI cmd used to send BDR
936 * There is no timeout for this operation. if this operation is
937 * unreliable for a given host, then the host itself needs to put a
938 * timer on it, and set the host back to a consistent state prior to
941 static enum scsi_disposition scsi_try_bus_device_reset(struct scsi_cmnd *scmd)
943 enum scsi_disposition rtn;
944 struct scsi_host_template *hostt = scmd->device->host->hostt;
946 if (!hostt->eh_device_reset_handler)
949 rtn = hostt->eh_device_reset_handler(scmd);
951 __scsi_report_device_reset(scmd->device, NULL);
956 * scsi_try_to_abort_cmd - Ask host to abort a SCSI command
957 * @hostt: SCSI driver host template
958 * @scmd: SCSI cmd used to send a target reset
961 * SUCCESS, FAILED, or FAST_IO_FAIL
964 * SUCCESS does not necessarily indicate that the command
965 * has been aborted; it only indicates that the LLDDs
966 * has cleared all references to that command.
967 * LLDDs should return FAILED only if an abort was required
968 * but could not be executed. LLDDs should return FAST_IO_FAIL
969 * if the device is temporarily unavailable (eg due to a
970 * link down on FibreChannel)
972 static enum scsi_disposition
973 scsi_try_to_abort_cmd(struct scsi_host_template *hostt, struct scsi_cmnd *scmd)
975 if (!hostt->eh_abort_handler)
978 return hostt->eh_abort_handler(scmd);
981 static void scsi_abort_eh_cmnd(struct scsi_cmnd *scmd)
983 if (scsi_try_to_abort_cmd(scmd->device->host->hostt, scmd) != SUCCESS)
984 if (scsi_try_bus_device_reset(scmd) != SUCCESS)
985 if (scsi_try_target_reset(scmd) != SUCCESS)
986 if (scsi_try_bus_reset(scmd) != SUCCESS)
987 scsi_try_host_reset(scmd);
991 * scsi_eh_prep_cmnd - Save a scsi command info as part of error recovery
992 * @scmd: SCSI command structure to hijack
993 * @ses: structure to save restore information
994 * @cmnd: CDB to send. Can be NULL if no new cmnd is needed
995 * @cmnd_size: size in bytes of @cmnd (must be <= MAX_COMMAND_SIZE)
996 * @sense_bytes: size of sense data to copy. or 0 (if != 0 @cmnd is ignored)
998 * This function is used to save a scsi command information before re-execution
999 * as part of the error recovery process. If @sense_bytes is 0 the command
1000 * sent must be one that does not transfer any data. If @sense_bytes != 0
1001 * @cmnd is ignored and this functions sets up a REQUEST_SENSE command
1002 * and cmnd buffers to read @sense_bytes into @scmd->sense_buffer.
1004 void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd, struct scsi_eh_save *ses,
1005 unsigned char *cmnd, int cmnd_size, unsigned sense_bytes)
1007 struct scsi_device *sdev = scmd->device;
1010 * We need saved copies of a number of fields - this is because
1011 * error handling may need to overwrite these with different values
1012 * to run different commands, and once error handling is complete,
1013 * we will need to restore these values prior to running the actual
1016 ses->cmd_len = scmd->cmd_len;
1017 ses->data_direction = scmd->sc_data_direction;
1018 ses->sdb = scmd->sdb;
1019 ses->result = scmd->result;
1020 ses->resid_len = scmd->resid_len;
1021 ses->underflow = scmd->underflow;
1022 ses->prot_op = scmd->prot_op;
1023 ses->eh_eflags = scmd->eh_eflags;
1025 scmd->prot_op = SCSI_PROT_NORMAL;
1026 scmd->eh_eflags = 0;
1027 memcpy(ses->cmnd, scmd->cmnd, sizeof(ses->cmnd));
1028 memset(scmd->cmnd, 0, sizeof(scmd->cmnd));
1029 memset(&scmd->sdb, 0, sizeof(scmd->sdb));
1031 scmd->resid_len = 0;
1034 scmd->sdb.length = min_t(unsigned, SCSI_SENSE_BUFFERSIZE,
1036 sg_init_one(&ses->sense_sgl, scmd->sense_buffer,
1038 scmd->sdb.table.sgl = &ses->sense_sgl;
1039 scmd->sc_data_direction = DMA_FROM_DEVICE;
1040 scmd->sdb.table.nents = scmd->sdb.table.orig_nents = 1;
1041 scmd->cmnd[0] = REQUEST_SENSE;
1042 scmd->cmnd[4] = scmd->sdb.length;
1043 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
1045 scmd->sc_data_direction = DMA_NONE;
1047 BUG_ON(cmnd_size > sizeof(scmd->cmnd));
1048 memcpy(scmd->cmnd, cmnd, cmnd_size);
1049 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
1053 scmd->underflow = 0;
1055 if (sdev->scsi_level <= SCSI_2 && sdev->scsi_level != SCSI_UNKNOWN)
1056 scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) |
1057 (sdev->lun << 5 & 0xe0);
1060 * Zero the sense buffer. The scsi spec mandates that any
1061 * untransferred sense data should be interpreted as being zero.
1063 memset(scmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
1065 EXPORT_SYMBOL(scsi_eh_prep_cmnd);
1068 * scsi_eh_restore_cmnd - Restore a scsi command info as part of error recovery
1069 * @scmd: SCSI command structure to restore
1070 * @ses: saved information from a coresponding call to scsi_eh_prep_cmnd
1072 * Undo any damage done by above scsi_eh_prep_cmnd().
1074 void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd, struct scsi_eh_save *ses)
1077 * Restore original data
1079 scmd->cmd_len = ses->cmd_len;
1080 memcpy(scmd->cmnd, ses->cmnd, sizeof(ses->cmnd));
1081 scmd->sc_data_direction = ses->data_direction;
1082 scmd->sdb = ses->sdb;
1083 scmd->result = ses->result;
1084 scmd->resid_len = ses->resid_len;
1085 scmd->underflow = ses->underflow;
1086 scmd->prot_op = ses->prot_op;
1087 scmd->eh_eflags = ses->eh_eflags;
1089 EXPORT_SYMBOL(scsi_eh_restore_cmnd);
1092 * scsi_send_eh_cmnd - submit a scsi command as part of error recovery
1093 * @scmd: SCSI command structure to hijack
1094 * @cmnd: CDB to send
1095 * @cmnd_size: size in bytes of @cmnd
1096 * @timeout: timeout for this request
1097 * @sense_bytes: size of sense data to copy or 0
1099 * This function is used to send a scsi command down to a target device
1100 * as part of the error recovery process. See also scsi_eh_prep_cmnd() above.
1103 * SUCCESS or FAILED or NEEDS_RETRY
1105 static enum scsi_disposition scsi_send_eh_cmnd(struct scsi_cmnd *scmd,
1106 unsigned char *cmnd, int cmnd_size, int timeout, unsigned sense_bytes)
1108 struct scsi_device *sdev = scmd->device;
1109 struct Scsi_Host *shost = sdev->host;
1110 DECLARE_COMPLETION_ONSTACK(done);
1111 unsigned long timeleft = timeout, delay;
1112 struct scsi_eh_save ses;
1113 const unsigned long stall_for = msecs_to_jiffies(100);
1117 scsi_eh_prep_cmnd(scmd, &ses, cmnd, cmnd_size, sense_bytes);
1118 shost->eh_action = &done;
1120 scsi_log_send(scmd);
1121 scmd->submitter = SUBMITTED_BY_SCSI_ERROR_HANDLER;
1124 * Lock sdev->state_mutex to avoid that scsi_device_quiesce() can
1125 * change the SCSI device state after we have examined it and before
1126 * .queuecommand() is called.
1128 mutex_lock(&sdev->state_mutex);
1129 while (sdev->sdev_state == SDEV_BLOCK && timeleft > 0) {
1130 mutex_unlock(&sdev->state_mutex);
1131 SCSI_LOG_ERROR_RECOVERY(5, sdev_printk(KERN_DEBUG, sdev,
1132 "%s: state %d <> %d\n", __func__, sdev->sdev_state,
1134 delay = min(timeleft, stall_for);
1136 msleep(jiffies_to_msecs(delay));
1137 mutex_lock(&sdev->state_mutex);
1139 if (sdev->sdev_state != SDEV_BLOCK)
1140 rtn = shost->hostt->queuecommand(shost, scmd);
1143 mutex_unlock(&sdev->state_mutex);
1146 if (timeleft > stall_for) {
1147 scsi_eh_restore_cmnd(scmd, &ses);
1149 timeleft -= stall_for;
1150 msleep(jiffies_to_msecs(stall_for));
1153 /* signal not to enter either branch of the if () below */
1157 timeleft = wait_for_completion_timeout(&done, timeout);
1161 shost->eh_action = NULL;
1163 scsi_log_completion(scmd, rtn);
1165 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1166 "%s timeleft: %ld\n",
1167 __func__, timeleft));
1170 * If there is time left scsi_eh_done got called, and we will examine
1171 * the actual status codes to see whether the command actually did
1172 * complete normally, else if we have a zero return and no time left,
1173 * the command must still be pending, so abort it and return FAILED.
1174 * If we never actually managed to issue the command, because
1175 * ->queuecommand() kept returning non zero, use the rtn = FAILED
1176 * value above (so don't execute either branch of the if)
1179 rtn = scsi_eh_completed_normally(scmd);
1180 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1181 "%s: scsi_eh_completed_normally %x\n", __func__, rtn));
1188 case ADD_TO_MLQUEUE:
1195 } else if (rtn != FAILED) {
1196 scsi_abort_eh_cmnd(scmd);
1200 scsi_eh_restore_cmnd(scmd, &ses);
1206 * scsi_request_sense - Request sense data from a particular target.
1207 * @scmd: SCSI cmd for request sense.
1210 * Some hosts automatically obtain this information, others require
1211 * that we obtain it on our own. This function will *not* return until
1212 * the command either times out, or it completes.
1214 static enum scsi_disposition scsi_request_sense(struct scsi_cmnd *scmd)
1216 return scsi_send_eh_cmnd(scmd, NULL, 0, scmd->device->eh_timeout, ~0);
1219 static enum scsi_disposition
1220 scsi_eh_action(struct scsi_cmnd *scmd, enum scsi_disposition rtn)
1222 if (!blk_rq_is_passthrough(scsi_cmd_to_rq(scmd))) {
1223 struct scsi_driver *sdrv = scsi_cmd_to_driver(scmd);
1224 if (sdrv->eh_action)
1225 rtn = sdrv->eh_action(scmd, rtn);
1231 * scsi_eh_finish_cmd - Handle a cmd that eh is finished with.
1232 * @scmd: Original SCSI cmd that eh has finished.
1233 * @done_q: Queue for processed commands.
1236 * We don't want to use the normal command completion while we are are
1237 * still handling errors - it may cause other commands to be queued,
1238 * and that would disturb what we are doing. Thus we really want to
1239 * keep a list of pending commands for final completion, and once we
1240 * are ready to leave error handling we handle completion for real.
1242 void scsi_eh_finish_cmd(struct scsi_cmnd *scmd, struct list_head *done_q)
1244 list_move_tail(&scmd->eh_entry, done_q);
1246 EXPORT_SYMBOL(scsi_eh_finish_cmd);
1249 * scsi_eh_get_sense - Get device sense data.
1250 * @work_q: Queue of commands to process.
1251 * @done_q: Queue of processed commands.
1254 * See if we need to request sense information. if so, then get it
1255 * now, so we have a better idea of what to do.
1258 * This has the unfortunate side effect that if a shost adapter does
1259 * not automatically request sense information, we end up shutting
1260 * it down before we request it.
1262 * All drivers should request sense information internally these days,
1263 * so for now all I have to say is tough noogies if you end up in here.
1265 * XXX: Long term this code should go away, but that needs an audit of
1268 int scsi_eh_get_sense(struct list_head *work_q,
1269 struct list_head *done_q)
1271 struct scsi_cmnd *scmd, *next;
1272 struct Scsi_Host *shost;
1273 enum scsi_disposition rtn;
1276 * If SCSI_EH_ABORT_SCHEDULED has been set, it is timeout IO,
1277 * should not get sense.
1279 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1280 if ((scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) ||
1281 SCSI_SENSE_VALID(scmd))
1284 shost = scmd->device->host;
1285 if (scsi_host_eh_past_deadline(shost)) {
1286 SCSI_LOG_ERROR_RECOVERY(3,
1287 scmd_printk(KERN_INFO, scmd,
1288 "%s: skip request sense, past eh deadline\n",
1292 if (!scsi_status_is_check_condition(scmd->result))
1294 * don't request sense if there's no check condition
1295 * status because the error we're processing isn't one
1296 * that has a sense code (and some devices get
1297 * confused by sense requests out of the blue)
1301 SCSI_LOG_ERROR_RECOVERY(2, scmd_printk(KERN_INFO, scmd,
1302 "%s: requesting sense\n",
1304 rtn = scsi_request_sense(scmd);
1308 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1309 "sense requested, result %x\n", scmd->result));
1310 SCSI_LOG_ERROR_RECOVERY(3, scsi_print_sense(scmd));
1312 rtn = scsi_decide_disposition(scmd);
1315 * if the result was normal, then just pass it along to the
1320 * We don't want this command reissued, just finished
1321 * with the sense data, so set retries to the max
1322 * allowed to ensure it won't get reissued. If the user
1323 * has requested infinite retries, we also want to
1324 * finish this command, so force completion by setting
1325 * retries and allowed to the same value.
1327 if (scmd->allowed == SCSI_CMD_RETRIES_NO_LIMIT)
1328 scmd->retries = scmd->allowed = 1;
1330 scmd->retries = scmd->allowed;
1331 else if (rtn != NEEDS_RETRY)
1334 scsi_eh_finish_cmd(scmd, done_q);
1337 return list_empty(work_q);
1339 EXPORT_SYMBOL_GPL(scsi_eh_get_sense);
1342 * scsi_eh_tur - Send TUR to device.
1343 * @scmd: &scsi_cmnd to send TUR
1346 * 0 - Device is ready. 1 - Device NOT ready.
1348 static int scsi_eh_tur(struct scsi_cmnd *scmd)
1350 static unsigned char tur_command[6] = {TEST_UNIT_READY, 0, 0, 0, 0, 0};
1352 enum scsi_disposition rtn;
1355 rtn = scsi_send_eh_cmnd(scmd, tur_command, 6,
1356 scmd->device->eh_timeout, 0);
1358 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1359 "%s return: %x\n", __func__, rtn));
1374 * scsi_eh_test_devices - check if devices are responding from error recovery.
1375 * @cmd_list: scsi commands in error recovery.
1376 * @work_q: queue for commands which still need more error recovery
1377 * @done_q: queue for commands which are finished
1378 * @try_stu: boolean on if a STU command should be tried in addition to TUR.
1381 * Tests if devices are in a working state. Commands to devices now in
1382 * a working state are sent to the done_q while commands to devices which
1383 * are still failing to respond are returned to the work_q for more
1386 static int scsi_eh_test_devices(struct list_head *cmd_list,
1387 struct list_head *work_q,
1388 struct list_head *done_q, int try_stu)
1390 struct scsi_cmnd *scmd, *next;
1391 struct scsi_device *sdev;
1394 while (!list_empty(cmd_list)) {
1395 scmd = list_entry(cmd_list->next, struct scsi_cmnd, eh_entry);
1396 sdev = scmd->device;
1399 if (scsi_host_eh_past_deadline(sdev->host)) {
1400 /* Push items back onto work_q */
1401 list_splice_init(cmd_list, work_q);
1402 SCSI_LOG_ERROR_RECOVERY(3,
1403 sdev_printk(KERN_INFO, sdev,
1404 "%s: skip test device, past eh deadline",
1410 finish_cmds = !scsi_device_online(scmd->device) ||
1411 (try_stu && !scsi_eh_try_stu(scmd) &&
1412 !scsi_eh_tur(scmd)) ||
1415 list_for_each_entry_safe(scmd, next, cmd_list, eh_entry)
1416 if (scmd->device == sdev) {
1419 scsi_eh_action(scmd, SUCCESS) == SUCCESS))
1420 scsi_eh_finish_cmd(scmd, done_q);
1422 list_move_tail(&scmd->eh_entry, work_q);
1425 return list_empty(work_q);
1429 * scsi_eh_try_stu - Send START_UNIT to device.
1430 * @scmd: &scsi_cmnd to send START_UNIT
1433 * 0 - Device is ready. 1 - Device NOT ready.
1435 static int scsi_eh_try_stu(struct scsi_cmnd *scmd)
1437 static unsigned char stu_command[6] = {START_STOP, 0, 0, 0, 1, 0};
1439 if (scmd->device->allow_restart) {
1441 enum scsi_disposition rtn = NEEDS_RETRY;
1443 for (i = 0; rtn == NEEDS_RETRY && i < 2; i++)
1444 rtn = scsi_send_eh_cmnd(scmd, stu_command, 6,
1445 scmd->device->eh_timeout, 0);
1455 * scsi_eh_stu - send START_UNIT if needed
1456 * @shost: &scsi host being recovered.
1457 * @work_q: &list_head for pending commands.
1458 * @done_q: &list_head for processed commands.
1461 * If commands are failing due to not ready, initializing command required,
1462 * try revalidating the device, which will end up sending a start unit.
1464 static int scsi_eh_stu(struct Scsi_Host *shost,
1465 struct list_head *work_q,
1466 struct list_head *done_q)
1468 struct scsi_cmnd *scmd, *stu_scmd, *next;
1469 struct scsi_device *sdev;
1471 shost_for_each_device(sdev, shost) {
1472 if (scsi_host_eh_past_deadline(shost)) {
1473 SCSI_LOG_ERROR_RECOVERY(3,
1474 sdev_printk(KERN_INFO, sdev,
1475 "%s: skip START_UNIT, past eh deadline\n",
1477 scsi_device_put(sdev);
1481 list_for_each_entry(scmd, work_q, eh_entry)
1482 if (scmd->device == sdev && SCSI_SENSE_VALID(scmd) &&
1483 scsi_check_sense(scmd) == FAILED ) {
1491 SCSI_LOG_ERROR_RECOVERY(3,
1492 sdev_printk(KERN_INFO, sdev,
1493 "%s: Sending START_UNIT\n",
1496 if (!scsi_eh_try_stu(stu_scmd)) {
1497 if (!scsi_device_online(sdev) ||
1498 !scsi_eh_tur(stu_scmd)) {
1499 list_for_each_entry_safe(scmd, next,
1501 if (scmd->device == sdev &&
1502 scsi_eh_action(scmd, SUCCESS) == SUCCESS)
1503 scsi_eh_finish_cmd(scmd, done_q);
1507 SCSI_LOG_ERROR_RECOVERY(3,
1508 sdev_printk(KERN_INFO, sdev,
1509 "%s: START_UNIT failed\n",
1514 return list_empty(work_q);
1519 * scsi_eh_bus_device_reset - send bdr if needed
1520 * @shost: scsi host being recovered.
1521 * @work_q: &list_head for pending commands.
1522 * @done_q: &list_head for processed commands.
1525 * Try a bus device reset. Still, look to see whether we have multiple
1526 * devices that are jammed or not - if we have multiple devices, it
1527 * makes no sense to try bus_device_reset - we really would need to try
1528 * a bus_reset instead.
1530 static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
1531 struct list_head *work_q,
1532 struct list_head *done_q)
1534 struct scsi_cmnd *scmd, *bdr_scmd, *next;
1535 struct scsi_device *sdev;
1536 enum scsi_disposition rtn;
1538 shost_for_each_device(sdev, shost) {
1539 if (scsi_host_eh_past_deadline(shost)) {
1540 SCSI_LOG_ERROR_RECOVERY(3,
1541 sdev_printk(KERN_INFO, sdev,
1542 "%s: skip BDR, past eh deadline\n",
1544 scsi_device_put(sdev);
1548 list_for_each_entry(scmd, work_q, eh_entry)
1549 if (scmd->device == sdev) {
1557 SCSI_LOG_ERROR_RECOVERY(3,
1558 sdev_printk(KERN_INFO, sdev,
1559 "%s: Sending BDR\n", current->comm));
1560 rtn = scsi_try_bus_device_reset(bdr_scmd);
1561 if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
1562 if (!scsi_device_online(sdev) ||
1563 rtn == FAST_IO_FAIL ||
1564 !scsi_eh_tur(bdr_scmd)) {
1565 list_for_each_entry_safe(scmd, next,
1567 if (scmd->device == sdev &&
1568 scsi_eh_action(scmd, rtn) != FAILED)
1569 scsi_eh_finish_cmd(scmd,
1574 SCSI_LOG_ERROR_RECOVERY(3,
1575 sdev_printk(KERN_INFO, sdev,
1576 "%s: BDR failed\n", current->comm));
1580 return list_empty(work_q);
1584 * scsi_eh_target_reset - send target reset if needed
1585 * @shost: scsi host being recovered.
1586 * @work_q: &list_head for pending commands.
1587 * @done_q: &list_head for processed commands.
1590 * Try a target reset.
1592 static int scsi_eh_target_reset(struct Scsi_Host *shost,
1593 struct list_head *work_q,
1594 struct list_head *done_q)
1596 LIST_HEAD(tmp_list);
1597 LIST_HEAD(check_list);
1599 list_splice_init(work_q, &tmp_list);
1601 while (!list_empty(&tmp_list)) {
1602 struct scsi_cmnd *next, *scmd;
1603 enum scsi_disposition rtn;
1606 if (scsi_host_eh_past_deadline(shost)) {
1607 /* push back on work queue for further processing */
1608 list_splice_init(&check_list, work_q);
1609 list_splice_init(&tmp_list, work_q);
1610 SCSI_LOG_ERROR_RECOVERY(3,
1611 shost_printk(KERN_INFO, shost,
1612 "%s: Skip target reset, past eh deadline\n",
1614 return list_empty(work_q);
1617 scmd = list_entry(tmp_list.next, struct scsi_cmnd, eh_entry);
1620 SCSI_LOG_ERROR_RECOVERY(3,
1621 shost_printk(KERN_INFO, shost,
1622 "%s: Sending target reset to target %d\n",
1623 current->comm, id));
1624 rtn = scsi_try_target_reset(scmd);
1625 if (rtn != SUCCESS && rtn != FAST_IO_FAIL)
1626 SCSI_LOG_ERROR_RECOVERY(3,
1627 shost_printk(KERN_INFO, shost,
1628 "%s: Target reset failed"
1630 current->comm, id));
1631 list_for_each_entry_safe(scmd, next, &tmp_list, eh_entry) {
1632 if (scmd_id(scmd) != id)
1636 list_move_tail(&scmd->eh_entry, &check_list);
1637 else if (rtn == FAST_IO_FAIL)
1638 scsi_eh_finish_cmd(scmd, done_q);
1640 /* push back on work queue for further processing */
1641 list_move(&scmd->eh_entry, work_q);
1645 return scsi_eh_test_devices(&check_list, work_q, done_q, 0);
1649 * scsi_eh_bus_reset - send a bus reset
1650 * @shost: &scsi host being recovered.
1651 * @work_q: &list_head for pending commands.
1652 * @done_q: &list_head for processed commands.
1654 static int scsi_eh_bus_reset(struct Scsi_Host *shost,
1655 struct list_head *work_q,
1656 struct list_head *done_q)
1658 struct scsi_cmnd *scmd, *chan_scmd, *next;
1659 LIST_HEAD(check_list);
1660 unsigned int channel;
1661 enum scsi_disposition rtn;
1664 * we really want to loop over the various channels, and do this on
1665 * a channel by channel basis. we should also check to see if any
1666 * of the failed commands are on soft_reset devices, and if so, skip
1670 for (channel = 0; channel <= shost->max_channel; channel++) {
1671 if (scsi_host_eh_past_deadline(shost)) {
1672 list_splice_init(&check_list, work_q);
1673 SCSI_LOG_ERROR_RECOVERY(3,
1674 shost_printk(KERN_INFO, shost,
1675 "%s: skip BRST, past eh deadline\n",
1677 return list_empty(work_q);
1681 list_for_each_entry(scmd, work_q, eh_entry) {
1682 if (channel == scmd_channel(scmd)) {
1686 * FIXME add back in some support for
1687 * soft_reset devices.
1694 SCSI_LOG_ERROR_RECOVERY(3,
1695 shost_printk(KERN_INFO, shost,
1696 "%s: Sending BRST chan: %d\n",
1697 current->comm, channel));
1698 rtn = scsi_try_bus_reset(chan_scmd);
1699 if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
1700 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1701 if (channel == scmd_channel(scmd)) {
1702 if (rtn == FAST_IO_FAIL)
1703 scsi_eh_finish_cmd(scmd,
1706 list_move_tail(&scmd->eh_entry,
1711 SCSI_LOG_ERROR_RECOVERY(3,
1712 shost_printk(KERN_INFO, shost,
1713 "%s: BRST failed chan: %d\n",
1714 current->comm, channel));
1717 return scsi_eh_test_devices(&check_list, work_q, done_q, 0);
1721 * scsi_eh_host_reset - send a host reset
1722 * @shost: host to be reset.
1723 * @work_q: &list_head for pending commands.
1724 * @done_q: &list_head for processed commands.
1726 static int scsi_eh_host_reset(struct Scsi_Host *shost,
1727 struct list_head *work_q,
1728 struct list_head *done_q)
1730 struct scsi_cmnd *scmd, *next;
1731 LIST_HEAD(check_list);
1732 enum scsi_disposition rtn;
1734 if (!list_empty(work_q)) {
1735 scmd = list_entry(work_q->next,
1736 struct scsi_cmnd, eh_entry);
1738 SCSI_LOG_ERROR_RECOVERY(3,
1739 shost_printk(KERN_INFO, shost,
1740 "%s: Sending HRST\n",
1743 rtn = scsi_try_host_reset(scmd);
1744 if (rtn == SUCCESS) {
1745 list_splice_init(work_q, &check_list);
1746 } else if (rtn == FAST_IO_FAIL) {
1747 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1748 scsi_eh_finish_cmd(scmd, done_q);
1751 SCSI_LOG_ERROR_RECOVERY(3,
1752 shost_printk(KERN_INFO, shost,
1753 "%s: HRST failed\n",
1757 return scsi_eh_test_devices(&check_list, work_q, done_q, 1);
1761 * scsi_eh_offline_sdevs - offline scsi devices that fail to recover
1762 * @work_q: &list_head for pending commands.
1763 * @done_q: &list_head for processed commands.
1765 static void scsi_eh_offline_sdevs(struct list_head *work_q,
1766 struct list_head *done_q)
1768 struct scsi_cmnd *scmd, *next;
1769 struct scsi_device *sdev;
1771 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1772 sdev_printk(KERN_INFO, scmd->device, "Device offlined - "
1773 "not ready after error recovery\n");
1774 sdev = scmd->device;
1776 mutex_lock(&sdev->state_mutex);
1777 scsi_device_set_state(sdev, SDEV_OFFLINE);
1778 mutex_unlock(&sdev->state_mutex);
1780 scsi_eh_finish_cmd(scmd, done_q);
1786 * scsi_noretry_cmd - determine if command should be failed fast
1787 * @scmd: SCSI cmd to examine.
1789 bool scsi_noretry_cmd(struct scsi_cmnd *scmd)
1791 struct request *req = scsi_cmd_to_rq(scmd);
1793 switch (host_byte(scmd->result)) {
1799 return !!(req->cmd_flags & REQ_FAILFAST_TRANSPORT);
1801 return !!(req->cmd_flags & REQ_FAILFAST_DEV);
1803 if (get_status_byte(scmd) == SAM_STAT_RESERVATION_CONFLICT)
1806 case DID_SOFT_ERROR:
1807 return !!(req->cmd_flags & REQ_FAILFAST_DRIVER);
1810 if (!scsi_status_is_check_condition(scmd->result))
1815 * assume caller has checked sense and determined
1816 * the check condition was retryable.
1818 if (req->cmd_flags & REQ_FAILFAST_DEV || blk_rq_is_passthrough(req))
1825 * scsi_decide_disposition - Disposition a cmd on return from LLD.
1826 * @scmd: SCSI cmd to examine.
1829 * This is *only* called when we are examining the status after sending
1830 * out the actual data command. any commands that are queued for error
1831 * recovery (e.g. test_unit_ready) do *not* come through here.
1833 * When this routine returns failed, it means the error handler thread
1834 * is woken. In cases where the error code indicates an error that
1835 * doesn't require the error handler read (i.e. we don't need to
1836 * abort/reset), this function should return SUCCESS.
1838 enum scsi_disposition scsi_decide_disposition(struct scsi_cmnd *scmd)
1840 enum scsi_disposition rtn;
1843 * if the device is offline, then we clearly just pass the result back
1844 * up to the top level.
1846 if (!scsi_device_online(scmd->device)) {
1847 SCSI_LOG_ERROR_RECOVERY(5, scmd_printk(KERN_INFO, scmd,
1848 "%s: device offline - report as SUCCESS\n", __func__));
1853 * first check the host byte, to see if there is anything in there
1854 * that would indicate what we need to do.
1856 switch (host_byte(scmd->result)) {
1857 case DID_PASSTHROUGH:
1859 * no matter what, pass this through to the upper layer.
1860 * nuke this special code so that it looks like we are saying
1863 scmd->result &= 0xff00ffff;
1867 * looks good. drop through, and check the next byte.
1871 if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) {
1872 set_host_byte(scmd, DID_TIME_OUT);
1876 case DID_NO_CONNECT:
1877 case DID_BAD_TARGET:
1879 * note - this means that we just report the status back
1880 * to the top level driver, not that we actually think
1881 * that it indicates SUCCESS.
1884 case DID_SOFT_ERROR:
1886 * when the low level driver returns did_soft_error,
1887 * it is responsible for keeping an internal retry counter
1888 * in order to avoid endless loops (db)
1895 return ADD_TO_MLQUEUE;
1896 case DID_TRANSPORT_DISRUPTED:
1898 * LLD/transport was disrupted during processing of the IO.
1899 * The transport class is now blocked/blocking,
1900 * and the transport will decide what to do with the IO
1901 * based on its timers and recovery capablilities if
1902 * there are enough retries.
1905 case DID_TRANSPORT_FAILFAST:
1907 * The transport decided to failfast the IO (most likely
1908 * the fast io fail tmo fired), so send IO directly upwards.
1911 case DID_TRANSPORT_MARGINAL:
1913 * caller has decided not to do retries on
1914 * abort success, so send IO directly upwards
1918 if (get_status_byte(scmd) == SAM_STAT_RESERVATION_CONFLICT)
1920 * execute reservation conflict processing code
1930 * when we scan the bus, we get timeout messages for
1931 * these commands if there is no device available.
1932 * other hosts report did_no_connect for the same thing.
1934 if ((scmd->cmnd[0] == TEST_UNIT_READY ||
1935 scmd->cmnd[0] == INQUIRY)) {
1947 * check the status byte to see if this indicates anything special.
1949 switch (get_status_byte(scmd)) {
1950 case SAM_STAT_TASK_SET_FULL:
1951 scsi_handle_queue_full(scmd->device);
1953 * the case of trying to send too many commands to a
1954 * tagged queueing device.
1959 * device can't talk to us at the moment. Should only
1960 * occur (SAM-3) when the task queue is empty, so will cause
1961 * the empty queue handling to trigger a stall in the
1964 return ADD_TO_MLQUEUE;
1966 if (scmd->cmnd[0] == REPORT_LUNS)
1967 scmd->device->sdev_target->expecting_lun_change = 0;
1968 scsi_handle_queue_ramp_up(scmd->device);
1970 case SAM_STAT_COMMAND_TERMINATED:
1972 case SAM_STAT_TASK_ABORTED:
1974 case SAM_STAT_CHECK_CONDITION:
1975 rtn = scsi_check_sense(scmd);
1976 if (rtn == NEEDS_RETRY)
1978 /* if rtn == FAILED, we have no sense information;
1979 * returning FAILED will wake the error handler thread
1980 * to collect the sense and redo the decide
1983 case SAM_STAT_CONDITION_MET:
1984 case SAM_STAT_INTERMEDIATE:
1985 case SAM_STAT_INTERMEDIATE_CONDITION_MET:
1986 case SAM_STAT_ACA_ACTIVE:
1988 * who knows? FIXME(eric)
1992 case SAM_STAT_RESERVATION_CONFLICT:
1993 sdev_printk(KERN_INFO, scmd->device,
1994 "reservation conflict\n");
1995 set_scsi_ml_byte(scmd, SCSIML_STAT_RESV_CONFLICT);
1996 return SUCCESS; /* causes immediate i/o error */
2002 /* we requeue for retry because the error was retryable, and
2003 * the request was not marked fast fail. Note that above,
2004 * even if the request is marked fast fail, we still requeue
2005 * for queue congestion conditions (QUEUE_FULL or BUSY) */
2006 if (scsi_cmd_retry_allowed(scmd) && !scsi_noretry_cmd(scmd)) {
2010 * no more retries - report this one back to upper level.
2016 static enum rq_end_io_ret eh_lock_door_done(struct request *req,
2017 blk_status_t status)
2019 blk_mq_free_request(req);
2020 return RQ_END_IO_NONE;
2024 * scsi_eh_lock_door - Prevent medium removal for the specified device
2025 * @sdev: SCSI device to prevent medium removal
2028 * We must be called from process context.
2031 * We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the
2032 * head of the devices request queue, and continue.
2034 static void scsi_eh_lock_door(struct scsi_device *sdev)
2036 struct scsi_cmnd *scmd;
2037 struct request *req;
2039 req = scsi_alloc_request(sdev->request_queue, REQ_OP_DRV_IN, 0);
2042 scmd = blk_mq_rq_to_pdu(req);
2044 scmd->cmnd[0] = ALLOW_MEDIUM_REMOVAL;
2048 scmd->cmnd[4] = SCSI_REMOVAL_PREVENT;
2050 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
2053 req->rq_flags |= RQF_QUIET;
2054 req->timeout = 10 * HZ;
2055 req->end_io = eh_lock_door_done;
2057 blk_execute_rq_nowait(req, true);
2061 * scsi_restart_operations - restart io operations to the specified host.
2062 * @shost: Host we are restarting.
2065 * When we entered the error handler, we blocked all further i/o to
2066 * this device. we need to 'reverse' this process.
2068 static void scsi_restart_operations(struct Scsi_Host *shost)
2070 struct scsi_device *sdev;
2071 unsigned long flags;
2074 * If the door was locked, we need to insert a door lock request
2075 * onto the head of the SCSI request queue for the device. There
2076 * is no point trying to lock the door of an off-line device.
2078 shost_for_each_device(sdev, shost) {
2079 if (scsi_device_online(sdev) && sdev->was_reset && sdev->locked) {
2080 scsi_eh_lock_door(sdev);
2081 sdev->was_reset = 0;
2086 * next free up anything directly waiting upon the host. this
2087 * will be requests for character device operations, and also for
2088 * ioctls to queued block devices.
2090 SCSI_LOG_ERROR_RECOVERY(3,
2091 shost_printk(KERN_INFO, shost, "waking up host to restart\n"));
2093 spin_lock_irqsave(shost->host_lock, flags);
2094 if (scsi_host_set_state(shost, SHOST_RUNNING))
2095 if (scsi_host_set_state(shost, SHOST_CANCEL))
2096 BUG_ON(scsi_host_set_state(shost, SHOST_DEL));
2097 spin_unlock_irqrestore(shost->host_lock, flags);
2099 wake_up(&shost->host_wait);
2102 * finally we need to re-initiate requests that may be pending. we will
2103 * have had everything blocked while error handling is taking place, and
2104 * now that error recovery is done, we will need to ensure that these
2105 * requests are started.
2107 scsi_run_host_queues(shost);
2110 * if eh is active and host_eh_scheduled is pending we need to re-run
2111 * recovery. we do this check after scsi_run_host_queues() to allow
2112 * everything pent up since the last eh run a chance to make forward
2113 * progress before we sync again. Either we'll immediately re-run
2114 * recovery or scsi_device_unbusy() will wake us again when these
2115 * pending commands complete.
2117 spin_lock_irqsave(shost->host_lock, flags);
2118 if (shost->host_eh_scheduled)
2119 if (scsi_host_set_state(shost, SHOST_RECOVERY))
2120 WARN_ON(scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY));
2121 spin_unlock_irqrestore(shost->host_lock, flags);
2125 * scsi_eh_ready_devs - check device ready state and recover if not.
2126 * @shost: host to be recovered.
2127 * @work_q: &list_head for pending commands.
2128 * @done_q: &list_head for processed commands.
2130 void scsi_eh_ready_devs(struct Scsi_Host *shost,
2131 struct list_head *work_q,
2132 struct list_head *done_q)
2134 if (!scsi_eh_stu(shost, work_q, done_q))
2135 if (!scsi_eh_bus_device_reset(shost, work_q, done_q))
2136 if (!scsi_eh_target_reset(shost, work_q, done_q))
2137 if (!scsi_eh_bus_reset(shost, work_q, done_q))
2138 if (!scsi_eh_host_reset(shost, work_q, done_q))
2139 scsi_eh_offline_sdevs(work_q,
2142 EXPORT_SYMBOL_GPL(scsi_eh_ready_devs);
2145 * scsi_eh_flush_done_q - finish processed commands or retry them.
2146 * @done_q: list_head of processed commands.
2148 void scsi_eh_flush_done_q(struct list_head *done_q)
2150 struct scsi_cmnd *scmd, *next;
2152 list_for_each_entry_safe(scmd, next, done_q, eh_entry) {
2153 list_del_init(&scmd->eh_entry);
2154 if (scsi_device_online(scmd->device) &&
2155 !scsi_noretry_cmd(scmd) && scsi_cmd_retry_allowed(scmd) &&
2156 scsi_eh_should_retry_cmd(scmd)) {
2157 SCSI_LOG_ERROR_RECOVERY(3,
2158 scmd_printk(KERN_INFO, scmd,
2159 "%s: flush retry cmd\n",
2161 scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY);
2164 * If just we got sense for the device (called
2165 * scsi_eh_get_sense), scmd->result is already
2166 * set, do not set DID_TIME_OUT.
2169 scmd->result |= (DID_TIME_OUT << 16);
2170 SCSI_LOG_ERROR_RECOVERY(3,
2171 scmd_printk(KERN_INFO, scmd,
2172 "%s: flush finish cmd\n",
2174 scsi_finish_command(scmd);
2178 EXPORT_SYMBOL(scsi_eh_flush_done_q);
2181 * scsi_unjam_host - Attempt to fix a host which has a cmd that failed.
2182 * @shost: Host to unjam.
2185 * When we come in here, we *know* that all commands on the bus have
2186 * either completed, failed or timed out. we also know that no further
2187 * commands are being sent to the host, so things are relatively quiet
2188 * and we have freedom to fiddle with things as we wish.
2190 * This is only the *default* implementation. it is possible for
2191 * individual drivers to supply their own version of this function, and
2192 * if the maintainer wishes to do this, it is strongly suggested that
2193 * this function be taken as a template and modified. this function
2194 * was designed to correctly handle problems for about 95% of the
2195 * different cases out there, and it should always provide at least a
2196 * reasonable amount of error recovery.
2198 * Any command marked 'failed' or 'timeout' must eventually have
2199 * scsi_finish_cmd() called for it. we do all of the retry stuff
2200 * here, so when we restart the host after we return it should have an
2203 static void scsi_unjam_host(struct Scsi_Host *shost)
2205 unsigned long flags;
2206 LIST_HEAD(eh_work_q);
2207 LIST_HEAD(eh_done_q);
2209 spin_lock_irqsave(shost->host_lock, flags);
2210 list_splice_init(&shost->eh_cmd_q, &eh_work_q);
2211 spin_unlock_irqrestore(shost->host_lock, flags);
2213 SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(shost, &eh_work_q));
2215 if (!scsi_eh_get_sense(&eh_work_q, &eh_done_q))
2216 scsi_eh_ready_devs(shost, &eh_work_q, &eh_done_q);
2218 spin_lock_irqsave(shost->host_lock, flags);
2219 if (shost->eh_deadline != -1)
2220 shost->last_reset = 0;
2221 spin_unlock_irqrestore(shost->host_lock, flags);
2222 scsi_eh_flush_done_q(&eh_done_q);
2226 * scsi_error_handler - SCSI error handler thread
2227 * @data: Host for which we are running.
2230 * This is the main error handling loop. This is run as a kernel thread
2231 * for every SCSI host and handles all error handling activity.
2233 int scsi_error_handler(void *data)
2235 struct Scsi_Host *shost = data;
2238 * We use TASK_INTERRUPTIBLE so that the thread is not
2239 * counted against the load average as a running process.
2240 * We never actually get interrupted because kthread_run
2241 * disables signal delivery for the created thread.
2245 * The sequence in kthread_stop() sets the stop flag first
2246 * then wakes the process. To avoid missed wakeups, the task
2247 * should always be in a non running state before the stop
2250 set_current_state(TASK_INTERRUPTIBLE);
2251 if (kthread_should_stop())
2254 if ((shost->host_failed == 0 && shost->host_eh_scheduled == 0) ||
2255 shost->host_failed != scsi_host_busy(shost)) {
2256 SCSI_LOG_ERROR_RECOVERY(1,
2257 shost_printk(KERN_INFO, shost,
2258 "scsi_eh_%d: sleeping\n",
2264 __set_current_state(TASK_RUNNING);
2265 SCSI_LOG_ERROR_RECOVERY(1,
2266 shost_printk(KERN_INFO, shost,
2267 "scsi_eh_%d: waking up %d/%d/%d\n",
2268 shost->host_no, shost->host_eh_scheduled,
2270 scsi_host_busy(shost)));
2273 * We have a host that is failing for some reason. Figure out
2274 * what we need to do to get it up and online again (if we can).
2275 * If we fail, we end up taking the thing offline.
2277 if (!shost->eh_noresume && scsi_autopm_get_host(shost) != 0) {
2278 SCSI_LOG_ERROR_RECOVERY(1,
2279 shost_printk(KERN_ERR, shost,
2280 "scsi_eh_%d: unable to autoresume\n",
2285 if (shost->transportt->eh_strategy_handler)
2286 shost->transportt->eh_strategy_handler(shost);
2288 scsi_unjam_host(shost);
2290 /* All scmds have been handled */
2291 shost->host_failed = 0;
2294 * Note - if the above fails completely, the action is to take
2295 * individual devices offline and flush the queue of any
2296 * outstanding requests that may have been pending. When we
2297 * restart, we restart any I/O to any other devices on the bus
2298 * which are still online.
2300 scsi_restart_operations(shost);
2301 if (!shost->eh_noresume)
2302 scsi_autopm_put_host(shost);
2304 __set_current_state(TASK_RUNNING);
2306 SCSI_LOG_ERROR_RECOVERY(1,
2307 shost_printk(KERN_INFO, shost,
2308 "Error handler scsi_eh_%d exiting\n",
2310 shost->ehandler = NULL;
2315 * Function: scsi_report_bus_reset()
2317 * Purpose: Utility function used by low-level drivers to report that
2318 * they have observed a bus reset on the bus being handled.
2320 * Arguments: shost - Host in question
2321 * channel - channel on which reset was observed.
2325 * Lock status: Host lock must be held.
2327 * Notes: This only needs to be called if the reset is one which
2328 * originates from an unknown location. Resets originated
2329 * by the mid-level itself don't need to call this, but there
2330 * should be no harm.
2332 * The main purpose of this is to make sure that a CHECK_CONDITION
2333 * is properly treated.
2335 void scsi_report_bus_reset(struct Scsi_Host *shost, int channel)
2337 struct scsi_device *sdev;
2339 __shost_for_each_device(sdev, shost) {
2340 if (channel == sdev_channel(sdev))
2341 __scsi_report_device_reset(sdev, NULL);
2344 EXPORT_SYMBOL(scsi_report_bus_reset);
2347 * Function: scsi_report_device_reset()
2349 * Purpose: Utility function used by low-level drivers to report that
2350 * they have observed a device reset on the device being handled.
2352 * Arguments: shost - Host in question
2353 * channel - channel on which reset was observed
2354 * target - target on which reset was observed
2358 * Lock status: Host lock must be held
2360 * Notes: This only needs to be called if the reset is one which
2361 * originates from an unknown location. Resets originated
2362 * by the mid-level itself don't need to call this, but there
2363 * should be no harm.
2365 * The main purpose of this is to make sure that a CHECK_CONDITION
2366 * is properly treated.
2368 void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
2370 struct scsi_device *sdev;
2372 __shost_for_each_device(sdev, shost) {
2373 if (channel == sdev_channel(sdev) &&
2374 target == sdev_id(sdev))
2375 __scsi_report_device_reset(sdev, NULL);
2378 EXPORT_SYMBOL(scsi_report_device_reset);
2381 * scsi_ioctl_reset: explicitly reset a host/bus/target/device
2382 * @dev: scsi_device to operate on
2383 * @arg: reset type (see sg.h)
2386 scsi_ioctl_reset(struct scsi_device *dev, int __user *arg)
2388 struct scsi_cmnd *scmd;
2389 struct Scsi_Host *shost = dev->host;
2391 unsigned long flags;
2393 enum scsi_disposition rtn;
2395 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2398 error = get_user(val, arg);
2402 if (scsi_autopm_get_host(shost) < 0)
2406 rq = kzalloc(sizeof(struct request) + sizeof(struct scsi_cmnd) +
2407 shost->hostt->cmd_size, GFP_KERNEL);
2409 goto out_put_autopm_host;
2410 blk_rq_init(NULL, rq);
2412 scmd = (struct scsi_cmnd *)(rq + 1);
2413 scsi_init_command(dev, scmd);
2415 scmd->submitter = SUBMITTED_BY_SCSI_RESET_IOCTL;
2416 memset(&scmd->sdb, 0, sizeof(scmd->sdb));
2420 scmd->sc_data_direction = DMA_BIDIRECTIONAL;
2422 spin_lock_irqsave(shost->host_lock, flags);
2423 shost->tmf_in_progress = 1;
2424 spin_unlock_irqrestore(shost->host_lock, flags);
2426 switch (val & ~SG_SCSI_RESET_NO_ESCALATE) {
2427 case SG_SCSI_RESET_NOTHING:
2430 case SG_SCSI_RESET_DEVICE:
2431 rtn = scsi_try_bus_device_reset(scmd);
2432 if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE))
2435 case SG_SCSI_RESET_TARGET:
2436 rtn = scsi_try_target_reset(scmd);
2437 if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE))
2440 case SG_SCSI_RESET_BUS:
2441 rtn = scsi_try_bus_reset(scmd);
2442 if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE))
2445 case SG_SCSI_RESET_HOST:
2446 rtn = scsi_try_host_reset(scmd);
2455 error = (rtn == SUCCESS) ? 0 : -EIO;
2457 spin_lock_irqsave(shost->host_lock, flags);
2458 shost->tmf_in_progress = 0;
2459 spin_unlock_irqrestore(shost->host_lock, flags);
2462 * be sure to wake up anyone who was sleeping or had their queue
2463 * suspended while we performed the TMF.
2465 SCSI_LOG_ERROR_RECOVERY(3,
2466 shost_printk(KERN_INFO, shost,
2467 "waking up host to restart after TMF\n"));
2469 wake_up(&shost->host_wait);
2470 scsi_run_host_queues(shost);
2474 out_put_autopm_host:
2475 scsi_autopm_put_host(shost);
2479 bool scsi_command_normalize_sense(const struct scsi_cmnd *cmd,
2480 struct scsi_sense_hdr *sshdr)
2482 return scsi_normalize_sense(cmd->sense_buffer,
2483 SCSI_SENSE_BUFFERSIZE, sshdr);
2485 EXPORT_SYMBOL(scsi_command_normalize_sense);
2488 * scsi_get_sense_info_fld - get information field from sense data (either fixed or descriptor format)
2489 * @sense_buffer: byte array of sense data
2490 * @sb_len: number of valid bytes in sense_buffer
2491 * @info_out: pointer to 64 integer where 8 or 4 byte information
2492 * field will be placed if found.
2495 * true if information field found, false if not found.
2497 bool scsi_get_sense_info_fld(const u8 *sense_buffer, int sb_len,
2504 switch (sense_buffer[0] & 0x7f) {
2507 if (sense_buffer[0] & 0x80) {
2508 *info_out = get_unaligned_be32(&sense_buffer[3]);
2514 ucp = scsi_sense_desc_find(sense_buffer, sb_len,
2516 if (ucp && (0xa == ucp[1])) {
2517 *info_out = get_unaligned_be64(&ucp[4]);
2525 EXPORT_SYMBOL(scsi_get_sense_info_fld);