2 * scsi_error.c Copyright (C) 1997 Eric Youngdale
4 * SCSI error/timeout handling
5 * Initial versions: Eric Youngdale. Based upon conversations with
6 * Leonard Zubkoff and David Miller at Linux Expo,
7 * ideas originating from all over the place.
9 * Restructured scsi_unjam_host and associated functions.
10 * September 04, 2002 Mike Anderson (andmike@us.ibm.com)
12 * Forward port of Russell King's (rmk@arm.linux.org.uk) changes and
14 * September 30, 2002 Mike Anderson (andmike@us.ibm.com)
17 #include <linux/module.h>
18 #include <linux/sched.h>
19 #include <linux/gfp.h>
20 #include <linux/timer.h>
21 #include <linux/string.h>
22 #include <linux/kernel.h>
23 #include <linux/freezer.h>
24 #include <linux/kthread.h>
25 #include <linux/interrupt.h>
26 #include <linux/blkdev.h>
27 #include <linux/delay.h>
28 #include <linux/jiffies.h>
30 #include <scsi/scsi.h>
31 #include <scsi/scsi_cmnd.h>
32 #include <scsi/scsi_dbg.h>
33 #include <scsi/scsi_device.h>
34 #include <scsi/scsi_driver.h>
35 #include <scsi/scsi_eh.h>
36 #include <scsi/scsi_transport.h>
37 #include <scsi/scsi_host.h>
38 #include <scsi/scsi_ioctl.h>
41 #include "scsi_priv.h"
42 #include "scsi_logging.h"
43 #include "scsi_transport_api.h"
45 #include <trace/events/scsi.h>
47 static void scsi_eh_done(struct scsi_cmnd
*scmd
);
50 * These should *probably* be handled by the host itself.
51 * Since it is allowed to sleep, it probably should.
53 #define BUS_RESET_SETTLE_TIME (10)
54 #define HOST_RESET_SETTLE_TIME (10)
56 static int scsi_eh_try_stu(struct scsi_cmnd
*scmd
);
57 static int scsi_try_to_abort_cmd(struct scsi_host_template
*,
60 /* called with shost->host_lock held */
61 void scsi_eh_wakeup(struct Scsi_Host
*shost
)
63 if (atomic_read(&shost
->host_busy
) == shost
->host_failed
) {
64 trace_scsi_eh_wakeup(shost
);
65 wake_up_process(shost
->ehandler
);
66 SCSI_LOG_ERROR_RECOVERY(5, shost_printk(KERN_INFO
, shost
,
67 "Waking error handler thread\n"));
72 * scsi_schedule_eh - schedule EH for SCSI host
73 * @shost: SCSI host to invoke error handling on.
75 * Schedule SCSI EH without scmd.
77 void scsi_schedule_eh(struct Scsi_Host
*shost
)
81 spin_lock_irqsave(shost
->host_lock
, flags
);
83 if (scsi_host_set_state(shost
, SHOST_RECOVERY
) == 0 ||
84 scsi_host_set_state(shost
, SHOST_CANCEL_RECOVERY
) == 0) {
85 shost
->host_eh_scheduled
++;
86 scsi_eh_wakeup(shost
);
89 spin_unlock_irqrestore(shost
->host_lock
, flags
);
91 EXPORT_SYMBOL_GPL(scsi_schedule_eh
);
93 static int scsi_host_eh_past_deadline(struct Scsi_Host
*shost
)
95 if (!shost
->last_reset
|| shost
->eh_deadline
== -1)
99 * 32bit accesses are guaranteed to be atomic
100 * (on all supported architectures), so instead
101 * of using a spinlock we can as well double check
102 * if eh_deadline has been set to 'off' during the
105 if (time_before(jiffies
, shost
->last_reset
+ shost
->eh_deadline
) &&
106 shost
->eh_deadline
> -1)
113 * scmd_eh_abort_handler - Handle command aborts
114 * @work: command to be aborted.
117 scmd_eh_abort_handler(struct work_struct
*work
)
119 struct scsi_cmnd
*scmd
=
120 container_of(work
, struct scsi_cmnd
, abort_work
.work
);
121 struct scsi_device
*sdev
= scmd
->device
;
124 if (scsi_host_eh_past_deadline(sdev
->host
)) {
125 SCSI_LOG_ERROR_RECOVERY(3,
126 scmd_printk(KERN_INFO
, scmd
,
127 "eh timeout, not aborting\n"));
129 SCSI_LOG_ERROR_RECOVERY(3,
130 scmd_printk(KERN_INFO
, scmd
,
131 "aborting command\n"));
132 rtn
= scsi_try_to_abort_cmd(sdev
->host
->hostt
, scmd
);
133 if (rtn
== SUCCESS
) {
134 set_host_byte(scmd
, DID_TIME_OUT
);
135 if (scsi_host_eh_past_deadline(sdev
->host
)) {
136 SCSI_LOG_ERROR_RECOVERY(3,
137 scmd_printk(KERN_INFO
, scmd
,
138 "eh timeout, not retrying "
139 "aborted command\n"));
140 } else if (!scsi_noretry_cmd(scmd
) &&
141 (++scmd
->retries
<= scmd
->allowed
)) {
142 SCSI_LOG_ERROR_RECOVERY(3,
143 scmd_printk(KERN_WARNING
, scmd
,
144 "retry aborted command\n"));
145 scsi_queue_insert(scmd
, SCSI_MLQUEUE_EH_RETRY
);
148 SCSI_LOG_ERROR_RECOVERY(3,
149 scmd_printk(KERN_WARNING
, scmd
,
150 "finish aborted command\n"));
151 scsi_finish_command(scmd
);
155 SCSI_LOG_ERROR_RECOVERY(3,
156 scmd_printk(KERN_INFO
, scmd
,
158 (rtn
== FAST_IO_FAIL
) ?
159 "not send" : "failed"));
163 if (!scsi_eh_scmd_add(scmd
, 0)) {
164 SCSI_LOG_ERROR_RECOVERY(3,
165 scmd_printk(KERN_WARNING
, scmd
,
166 "terminate aborted command\n"));
167 set_host_byte(scmd
, DID_TIME_OUT
);
168 scsi_finish_command(scmd
);
173 * scsi_abort_command - schedule a command abort
174 * @scmd: scmd to abort.
176 * We only need to abort commands after a command timeout
179 scsi_abort_command(struct scsi_cmnd
*scmd
)
181 struct scsi_device
*sdev
= scmd
->device
;
182 struct Scsi_Host
*shost
= sdev
->host
;
185 if (scmd
->eh_eflags
& SCSI_EH_ABORT_SCHEDULED
) {
187 * Retry after abort failed, escalate to next level.
189 scmd
->eh_eflags
&= ~SCSI_EH_ABORT_SCHEDULED
;
190 SCSI_LOG_ERROR_RECOVERY(3,
191 scmd_printk(KERN_INFO
, scmd
,
192 "previous abort failed\n"));
193 BUG_ON(delayed_work_pending(&scmd
->abort_work
));
198 * Do not try a command abort if
199 * SCSI EH has already started.
201 spin_lock_irqsave(shost
->host_lock
, flags
);
202 if (scsi_host_in_recovery(shost
)) {
203 spin_unlock_irqrestore(shost
->host_lock
, flags
);
204 SCSI_LOG_ERROR_RECOVERY(3,
205 scmd_printk(KERN_INFO
, scmd
,
206 "not aborting, host in recovery\n"));
210 if (shost
->eh_deadline
!= -1 && !shost
->last_reset
)
211 shost
->last_reset
= jiffies
;
212 spin_unlock_irqrestore(shost
->host_lock
, flags
);
214 scmd
->eh_eflags
|= SCSI_EH_ABORT_SCHEDULED
;
215 SCSI_LOG_ERROR_RECOVERY(3,
216 scmd_printk(KERN_INFO
, scmd
, "abort scheduled\n"));
217 queue_delayed_work(shost
->tmf_work_q
, &scmd
->abort_work
, HZ
/ 100);
222 * scsi_eh_scmd_add - add scsi cmd to error handling.
223 * @scmd: scmd to run eh on.
224 * @eh_flag: optional SCSI_EH flag.
229 int scsi_eh_scmd_add(struct scsi_cmnd
*scmd
, int eh_flag
)
231 struct Scsi_Host
*shost
= scmd
->device
->host
;
235 if (!shost
->ehandler
)
238 spin_lock_irqsave(shost
->host_lock
, flags
);
239 if (scsi_host_set_state(shost
, SHOST_RECOVERY
))
240 if (scsi_host_set_state(shost
, SHOST_CANCEL_RECOVERY
))
243 if (shost
->eh_deadline
!= -1 && !shost
->last_reset
)
244 shost
->last_reset
= jiffies
;
247 if (scmd
->eh_eflags
& SCSI_EH_ABORT_SCHEDULED
)
248 eh_flag
&= ~SCSI_EH_CANCEL_CMD
;
249 scmd
->eh_eflags
|= eh_flag
;
250 list_add_tail(&scmd
->eh_entry
, &shost
->eh_cmd_q
);
251 shost
->host_failed
++;
252 scsi_eh_wakeup(shost
);
254 spin_unlock_irqrestore(shost
->host_lock
, flags
);
259 * scsi_times_out - Timeout function for normal scsi commands.
260 * @req: request that is timing out.
263 * We do not need to lock this. There is the potential for a race
264 * only in that the normal completion handling might run, but if the
265 * normal completion function determines that the timer has already
266 * fired, then it mustn't do anything.
268 enum blk_eh_timer_return
scsi_times_out(struct request
*req
)
270 struct scsi_cmnd
*scmd
= req
->special
;
271 enum blk_eh_timer_return rtn
= BLK_EH_NOT_HANDLED
;
272 struct Scsi_Host
*host
= scmd
->device
->host
;
274 trace_scsi_dispatch_cmd_timeout(scmd
);
275 scsi_log_completion(scmd
, TIMEOUT_ERROR
);
277 if (host
->eh_deadline
!= -1 && !host
->last_reset
)
278 host
->last_reset
= jiffies
;
280 if (host
->transportt
->eh_timed_out
)
281 rtn
= host
->transportt
->eh_timed_out(scmd
);
282 else if (host
->hostt
->eh_timed_out
)
283 rtn
= host
->hostt
->eh_timed_out(scmd
);
285 if (rtn
== BLK_EH_NOT_HANDLED
) {
286 if (!host
->hostt
->no_async_abort
&&
287 scsi_abort_command(scmd
) == SUCCESS
)
288 return BLK_EH_NOT_HANDLED
;
290 set_host_byte(scmd
, DID_TIME_OUT
);
291 if (!scsi_eh_scmd_add(scmd
, SCSI_EH_CANCEL_CMD
))
292 rtn
= BLK_EH_HANDLED
;
299 * scsi_block_when_processing_errors - Prevent cmds from being queued.
300 * @sdev: Device on which we are performing recovery.
303 * We block until the host is out of error recovery, and then check to
304 * see whether the host or the device is offline.
307 * 0 when dev was taken offline by error recovery. 1 OK to proceed.
309 int scsi_block_when_processing_errors(struct scsi_device
*sdev
)
313 wait_event(sdev
->host
->host_wait
, !scsi_host_in_recovery(sdev
->host
));
315 online
= scsi_device_online(sdev
);
317 SCSI_LOG_ERROR_RECOVERY(5, sdev_printk(KERN_INFO
, sdev
,
318 "%s: rtn: %d\n", __func__
, online
));
322 EXPORT_SYMBOL(scsi_block_when_processing_errors
);
324 #ifdef CONFIG_SCSI_LOGGING
326 * scsi_eh_prt_fail_stats - Log info on failures.
327 * @shost: scsi host being recovered.
328 * @work_q: Queue of scsi cmds to process.
330 static inline void scsi_eh_prt_fail_stats(struct Scsi_Host
*shost
,
331 struct list_head
*work_q
)
333 struct scsi_cmnd
*scmd
;
334 struct scsi_device
*sdev
;
335 int total_failures
= 0;
338 int devices_failed
= 0;
340 shost_for_each_device(sdev
, shost
) {
341 list_for_each_entry(scmd
, work_q
, eh_entry
) {
342 if (scmd
->device
== sdev
) {
344 if (scmd
->eh_eflags
& SCSI_EH_CANCEL_CMD
)
351 if (cmd_cancel
|| cmd_failed
) {
352 SCSI_LOG_ERROR_RECOVERY(3,
353 shost_printk(KERN_INFO
, shost
,
354 "%s: cmds failed: %d, cancel: %d\n",
355 __func__
, cmd_failed
,
363 SCSI_LOG_ERROR_RECOVERY(2, shost_printk(KERN_INFO
, shost
,
364 "Total of %d commands on %d"
365 " devices require eh work\n",
366 total_failures
, devices_failed
));
371 * scsi_report_lun_change - Set flag on all *other* devices on the same target
372 * to indicate that a UNIT ATTENTION is expected.
373 * @sdev: Device reporting the UNIT ATTENTION
375 static void scsi_report_lun_change(struct scsi_device
*sdev
)
377 sdev
->sdev_target
->expecting_lun_change
= 1;
381 * scsi_report_sense - Examine scsi sense information and log messages for
382 * certain conditions, also issue uevents for some of them.
383 * @sdev: Device reporting the sense code
384 * @sshdr: sshdr to be examined
386 static void scsi_report_sense(struct scsi_device
*sdev
,
387 struct scsi_sense_hdr
*sshdr
)
389 enum scsi_device_event evt_type
= SDEV_EVT_MAXBITS
; /* i.e. none */
391 if (sshdr
->sense_key
== UNIT_ATTENTION
) {
392 if (sshdr
->asc
== 0x3f && sshdr
->ascq
== 0x03) {
393 evt_type
= SDEV_EVT_INQUIRY_CHANGE_REPORTED
;
394 sdev_printk(KERN_WARNING
, sdev
,
395 "Inquiry data has changed");
396 } else if (sshdr
->asc
== 0x3f && sshdr
->ascq
== 0x0e) {
397 evt_type
= SDEV_EVT_LUN_CHANGE_REPORTED
;
398 scsi_report_lun_change(sdev
);
399 sdev_printk(KERN_WARNING
, sdev
,
400 "Warning! Received an indication that the "
401 "LUN assignments on this target have "
402 "changed. The Linux SCSI layer does not "
403 "automatically remap LUN assignments.\n");
404 } else if (sshdr
->asc
== 0x3f)
405 sdev_printk(KERN_WARNING
, sdev
,
406 "Warning! Received an indication that the "
407 "operating parameters on this target have "
408 "changed. The Linux SCSI layer does not "
409 "automatically adjust these parameters.\n");
411 if (sshdr
->asc
== 0x38 && sshdr
->ascq
== 0x07) {
412 evt_type
= SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED
;
413 sdev_printk(KERN_WARNING
, sdev
,
414 "Warning! Received an indication that the "
415 "LUN reached a thin provisioning soft "
419 if (sshdr
->asc
== 0x2a && sshdr
->ascq
== 0x01) {
420 evt_type
= SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED
;
421 sdev_printk(KERN_WARNING
, sdev
,
422 "Mode parameters changed");
423 } else if (sshdr
->asc
== 0x2a && sshdr
->ascq
== 0x06) {
424 evt_type
= SDEV_EVT_ALUA_STATE_CHANGE_REPORTED
;
425 sdev_printk(KERN_WARNING
, sdev
,
426 "Asymmetric access state changed");
427 } else if (sshdr
->asc
== 0x2a && sshdr
->ascq
== 0x09) {
428 evt_type
= SDEV_EVT_CAPACITY_CHANGE_REPORTED
;
429 sdev_printk(KERN_WARNING
, sdev
,
430 "Capacity data has changed");
431 } else if (sshdr
->asc
== 0x2a)
432 sdev_printk(KERN_WARNING
, sdev
,
433 "Parameters changed");
436 if (evt_type
!= SDEV_EVT_MAXBITS
) {
437 set_bit(evt_type
, sdev
->pending_events
);
438 schedule_work(&sdev
->event_work
);
443 * scsi_check_sense - Examine scsi cmd sense
444 * @scmd: Cmd to have sense checked.
447 * SUCCESS or FAILED or NEEDS_RETRY or ADD_TO_MLQUEUE
450 * When a deferred error is detected the current command has
451 * not been executed and needs retrying.
453 static int scsi_check_sense(struct scsi_cmnd
*scmd
)
455 struct scsi_device
*sdev
= scmd
->device
;
456 struct scsi_sense_hdr sshdr
;
458 if (! scsi_command_normalize_sense(scmd
, &sshdr
))
459 return FAILED
; /* no valid sense data */
461 scsi_report_sense(sdev
, &sshdr
);
463 if (scsi_sense_is_deferred(&sshdr
))
466 if (sdev
->scsi_dh_data
&& sdev
->scsi_dh_data
->scsi_dh
&&
467 sdev
->scsi_dh_data
->scsi_dh
->check_sense
) {
470 rc
= sdev
->scsi_dh_data
->scsi_dh
->check_sense(sdev
, &sshdr
);
471 if (rc
!= SCSI_RETURN_NOT_HANDLED
)
473 /* handler does not care. Drop down to default handling */
476 if (scmd
->cmnd
[0] == TEST_UNIT_READY
&& scmd
->scsi_done
!= scsi_eh_done
)
478 * nasty: for mid-layer issued TURs, we need to return the
479 * actual sense data without any recovery attempt. For eh
480 * issued ones, we need to try to recover and interpret
485 * Previous logic looked for FILEMARK, EOM or ILI which are
486 * mainly associated with tapes and returned SUCCESS.
488 if (sshdr
.response_code
== 0x70) {
490 if (scmd
->sense_buffer
[2] & 0xe0)
494 * descriptor format: look for "stream commands sense data
495 * descriptor" (see SSC-3). Assume single sense data
496 * descriptor. Ignore ILI from SBC-2 READ LONG and WRITE LONG.
498 if ((sshdr
.additional_length
> 3) &&
499 (scmd
->sense_buffer
[8] == 0x4) &&
500 (scmd
->sense_buffer
[11] & 0xe0))
504 switch (sshdr
.sense_key
) {
507 case RECOVERED_ERROR
:
508 return /* soft_error */ SUCCESS
;
510 case ABORTED_COMMAND
:
511 if (sshdr
.asc
== 0x10) /* DIF */
518 * if we are expecting a cc/ua because of a bus reset that we
519 * performed, treat this just as a retry. otherwise this is
520 * information that we should pass up to the upper-level driver
521 * so that we can deal with it there.
523 if (scmd
->device
->expecting_cc_ua
) {
525 * Because some device does not queue unit
526 * attentions correctly, we carefully check
527 * additional sense code and qualifier so as
528 * not to squash media change unit attention.
530 if (sshdr
.asc
!= 0x28 || sshdr
.ascq
!= 0x00) {
531 scmd
->device
->expecting_cc_ua
= 0;
536 * we might also expect a cc/ua if another LUN on the target
537 * reported a UA with an ASC/ASCQ of 3F 0E -
538 * REPORTED LUNS DATA HAS CHANGED.
540 if (scmd
->device
->sdev_target
->expecting_lun_change
&&
541 sshdr
.asc
== 0x3f && sshdr
.ascq
== 0x0e)
544 * if the device is in the process of becoming ready, we
547 if ((sshdr
.asc
== 0x04) && (sshdr
.ascq
== 0x01))
550 * if the device is not started, we need to wake
551 * the error handler to start the motor
553 if (scmd
->device
->allow_restart
&&
554 (sshdr
.asc
== 0x04) && (sshdr
.ascq
== 0x02))
557 * Pass the UA upwards for a determination in the completion
562 /* these are not supported */
564 if (sshdr
.asc
== 0x27 && sshdr
.ascq
== 0x07) {
565 /* Thin provisioning hard threshold reached */
566 set_host_byte(scmd
, DID_ALLOC_FAILURE
);
570 case VOLUME_OVERFLOW
:
573 set_host_byte(scmd
, DID_TARGET_FAILURE
);
577 if (sshdr
.asc
== 0x11 || /* UNRECOVERED READ ERR */
578 sshdr
.asc
== 0x13 || /* AMNF DATA FIELD */
579 sshdr
.asc
== 0x14) { /* RECORD NOT FOUND */
580 set_host_byte(scmd
, DID_MEDIUM_ERROR
);
586 if (scmd
->device
->retry_hwerror
)
587 return ADD_TO_MLQUEUE
;
589 set_host_byte(scmd
, DID_TARGET_FAILURE
);
591 case ILLEGAL_REQUEST
:
592 if (sshdr
.asc
== 0x20 || /* Invalid command operation code */
593 sshdr
.asc
== 0x21 || /* Logical block address out of range */
594 sshdr
.asc
== 0x24 || /* Invalid field in cdb */
595 sshdr
.asc
== 0x26) { /* Parameter value invalid */
596 set_host_byte(scmd
, DID_TARGET_FAILURE
);
605 static void scsi_handle_queue_ramp_up(struct scsi_device
*sdev
)
607 struct scsi_host_template
*sht
= sdev
->host
->hostt
;
608 struct scsi_device
*tmp_sdev
;
610 if (!sht
->track_queue_depth
||
611 sdev
->queue_depth
>= sdev
->max_queue_depth
)
614 if (time_before(jiffies
,
615 sdev
->last_queue_ramp_up
+ sdev
->queue_ramp_up_period
))
618 if (time_before(jiffies
,
619 sdev
->last_queue_full_time
+ sdev
->queue_ramp_up_period
))
623 * Walk all devices of a target and do
626 shost_for_each_device(tmp_sdev
, sdev
->host
) {
627 if (tmp_sdev
->channel
!= sdev
->channel
||
628 tmp_sdev
->id
!= sdev
->id
||
629 tmp_sdev
->queue_depth
== sdev
->max_queue_depth
)
632 scsi_change_queue_depth(tmp_sdev
, tmp_sdev
->queue_depth
+ 1);
633 sdev
->last_queue_ramp_up
= jiffies
;
637 static void scsi_handle_queue_full(struct scsi_device
*sdev
)
639 struct scsi_host_template
*sht
= sdev
->host
->hostt
;
640 struct scsi_device
*tmp_sdev
;
642 if (!sht
->track_queue_depth
)
645 shost_for_each_device(tmp_sdev
, sdev
->host
) {
646 if (tmp_sdev
->channel
!= sdev
->channel
||
647 tmp_sdev
->id
!= sdev
->id
)
650 * We do not know the number of commands that were at
651 * the device when we got the queue full so we start
652 * from the highest possible value and work our way down.
654 scsi_track_queue_full(tmp_sdev
, tmp_sdev
->queue_depth
- 1);
659 * scsi_eh_completed_normally - Disposition a eh cmd on return from LLD.
660 * @scmd: SCSI cmd to examine.
663 * This is *only* called when we are examining the status of commands
664 * queued during error recovery. the main difference here is that we
665 * don't allow for the possibility of retries here, and we are a lot
666 * more restrictive about what we consider acceptable.
668 static int scsi_eh_completed_normally(struct scsi_cmnd
*scmd
)
671 * first check the host byte, to see if there is anything in there
672 * that would indicate what we need to do.
674 if (host_byte(scmd
->result
) == DID_RESET
) {
676 * rats. we are already in the error handler, so we now
677 * get to try and figure out what to do next. if the sense
678 * is valid, we have a pretty good idea of what to do.
679 * if not, we mark it as FAILED.
681 return scsi_check_sense(scmd
);
683 if (host_byte(scmd
->result
) != DID_OK
)
687 * next, check the message byte.
689 if (msg_byte(scmd
->result
) != COMMAND_COMPLETE
)
693 * now, check the status byte to see if this indicates
696 switch (status_byte(scmd
->result
)) {
698 scsi_handle_queue_ramp_up(scmd
->device
);
699 case COMMAND_TERMINATED
:
701 case CHECK_CONDITION
:
702 return scsi_check_sense(scmd
);
704 case INTERMEDIATE_GOOD
:
705 case INTERMEDIATE_C_GOOD
:
707 * who knows? FIXME(eric)
710 case RESERVATION_CONFLICT
:
711 if (scmd
->cmnd
[0] == TEST_UNIT_READY
)
712 /* it is a success, we probed the device and
715 /* otherwise, we failed to send the command */
718 scsi_handle_queue_full(scmd
->device
);
729 * scsi_eh_done - Completion function for error handling.
730 * @scmd: Cmd that is done.
732 static void scsi_eh_done(struct scsi_cmnd
*scmd
)
734 struct completion
*eh_action
;
736 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO
, scmd
,
737 "%s result: %x\n", __func__
, scmd
->result
));
739 eh_action
= scmd
->device
->host
->eh_action
;
745 * scsi_try_host_reset - ask host adapter to reset itself
746 * @scmd: SCSI cmd to send host reset.
748 static int scsi_try_host_reset(struct scsi_cmnd
*scmd
)
752 struct Scsi_Host
*host
= scmd
->device
->host
;
753 struct scsi_host_template
*hostt
= host
->hostt
;
755 SCSI_LOG_ERROR_RECOVERY(3,
756 shost_printk(KERN_INFO
, host
, "Snd Host RST\n"));
758 if (!hostt
->eh_host_reset_handler
)
761 rtn
= hostt
->eh_host_reset_handler(scmd
);
763 if (rtn
== SUCCESS
) {
764 if (!hostt
->skip_settle_delay
)
765 ssleep(HOST_RESET_SETTLE_TIME
);
766 spin_lock_irqsave(host
->host_lock
, flags
);
767 scsi_report_bus_reset(host
, scmd_channel(scmd
));
768 spin_unlock_irqrestore(host
->host_lock
, flags
);
775 * scsi_try_bus_reset - ask host to perform a bus reset
776 * @scmd: SCSI cmd to send bus reset.
778 static int scsi_try_bus_reset(struct scsi_cmnd
*scmd
)
782 struct Scsi_Host
*host
= scmd
->device
->host
;
783 struct scsi_host_template
*hostt
= host
->hostt
;
785 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO
, scmd
,
786 "%s: Snd Bus RST\n", __func__
));
788 if (!hostt
->eh_bus_reset_handler
)
791 rtn
= hostt
->eh_bus_reset_handler(scmd
);
793 if (rtn
== SUCCESS
) {
794 if (!hostt
->skip_settle_delay
)
795 ssleep(BUS_RESET_SETTLE_TIME
);
796 spin_lock_irqsave(host
->host_lock
, flags
);
797 scsi_report_bus_reset(host
, scmd_channel(scmd
));
798 spin_unlock_irqrestore(host
->host_lock
, flags
);
804 static void __scsi_report_device_reset(struct scsi_device
*sdev
, void *data
)
807 sdev
->expecting_cc_ua
= 1;
811 * scsi_try_target_reset - Ask host to perform a target reset
812 * @scmd: SCSI cmd used to send a target reset
815 * There is no timeout for this operation. if this operation is
816 * unreliable for a given host, then the host itself needs to put a
817 * timer on it, and set the host back to a consistent state prior to
820 static int scsi_try_target_reset(struct scsi_cmnd
*scmd
)
824 struct Scsi_Host
*host
= scmd
->device
->host
;
825 struct scsi_host_template
*hostt
= host
->hostt
;
827 if (!hostt
->eh_target_reset_handler
)
830 rtn
= hostt
->eh_target_reset_handler(scmd
);
831 if (rtn
== SUCCESS
) {
832 spin_lock_irqsave(host
->host_lock
, flags
);
833 __starget_for_each_device(scsi_target(scmd
->device
), NULL
,
834 __scsi_report_device_reset
);
835 spin_unlock_irqrestore(host
->host_lock
, flags
);
842 * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev
843 * @scmd: SCSI cmd used to send BDR
846 * There is no timeout for this operation. if this operation is
847 * unreliable for a given host, then the host itself needs to put a
848 * timer on it, and set the host back to a consistent state prior to
851 static int scsi_try_bus_device_reset(struct scsi_cmnd
*scmd
)
854 struct scsi_host_template
*hostt
= scmd
->device
->host
->hostt
;
856 if (!hostt
->eh_device_reset_handler
)
859 rtn
= hostt
->eh_device_reset_handler(scmd
);
861 __scsi_report_device_reset(scmd
->device
, NULL
);
866 * scsi_try_to_abort_cmd - Ask host to abort a SCSI command
867 * @hostt: SCSI driver host template
868 * @scmd: SCSI cmd used to send a target reset
871 * SUCCESS, FAILED, or FAST_IO_FAIL
874 * SUCCESS does not necessarily indicate that the command
875 * has been aborted; it only indicates that the LLDDs
876 * has cleared all references to that command.
877 * LLDDs should return FAILED only if an abort was required
878 * but could not be executed. LLDDs should return FAST_IO_FAIL
879 * if the device is temporarily unavailable (eg due to a
880 * link down on FibreChannel)
882 static int scsi_try_to_abort_cmd(struct scsi_host_template
*hostt
,
883 struct scsi_cmnd
*scmd
)
885 if (!hostt
->eh_abort_handler
)
888 return hostt
->eh_abort_handler(scmd
);
891 static void scsi_abort_eh_cmnd(struct scsi_cmnd
*scmd
)
893 if (scsi_try_to_abort_cmd(scmd
->device
->host
->hostt
, scmd
) != SUCCESS
)
894 if (scsi_try_bus_device_reset(scmd
) != SUCCESS
)
895 if (scsi_try_target_reset(scmd
) != SUCCESS
)
896 if (scsi_try_bus_reset(scmd
) != SUCCESS
)
897 scsi_try_host_reset(scmd
);
901 * scsi_eh_prep_cmnd - Save a scsi command info as part of error recovery
902 * @scmd: SCSI command structure to hijack
903 * @ses: structure to save restore information
904 * @cmnd: CDB to send. Can be NULL if no new cmnd is needed
905 * @cmnd_size: size in bytes of @cmnd (must be <= BLK_MAX_CDB)
906 * @sense_bytes: size of sense data to copy. or 0 (if != 0 @cmnd is ignored)
908 * This function is used to save a scsi command information before re-execution
909 * as part of the error recovery process. If @sense_bytes is 0 the command
910 * sent must be one that does not transfer any data. If @sense_bytes != 0
911 * @cmnd is ignored and this functions sets up a REQUEST_SENSE command
912 * and cmnd buffers to read @sense_bytes into @scmd->sense_buffer.
914 void scsi_eh_prep_cmnd(struct scsi_cmnd
*scmd
, struct scsi_eh_save
*ses
,
915 unsigned char *cmnd
, int cmnd_size
, unsigned sense_bytes
)
917 struct scsi_device
*sdev
= scmd
->device
;
920 * We need saved copies of a number of fields - this is because
921 * error handling may need to overwrite these with different values
922 * to run different commands, and once error handling is complete,
923 * we will need to restore these values prior to running the actual
926 ses
->cmd_len
= scmd
->cmd_len
;
927 ses
->cmnd
= scmd
->cmnd
;
928 ses
->data_direction
= scmd
->sc_data_direction
;
929 ses
->sdb
= scmd
->sdb
;
930 ses
->next_rq
= scmd
->request
->next_rq
;
931 ses
->result
= scmd
->result
;
932 ses
->underflow
= scmd
->underflow
;
933 ses
->prot_op
= scmd
->prot_op
;
935 scmd
->prot_op
= SCSI_PROT_NORMAL
;
937 scmd
->cmnd
= ses
->eh_cmnd
;
938 memset(scmd
->cmnd
, 0, BLK_MAX_CDB
);
939 memset(&scmd
->sdb
, 0, sizeof(scmd
->sdb
));
940 scmd
->request
->next_rq
= NULL
;
944 scmd
->sdb
.length
= min_t(unsigned, SCSI_SENSE_BUFFERSIZE
,
946 sg_init_one(&ses
->sense_sgl
, scmd
->sense_buffer
,
948 scmd
->sdb
.table
.sgl
= &ses
->sense_sgl
;
949 scmd
->sc_data_direction
= DMA_FROM_DEVICE
;
950 scmd
->sdb
.table
.nents
= scmd
->sdb
.table
.orig_nents
= 1;
951 scmd
->cmnd
[0] = REQUEST_SENSE
;
952 scmd
->cmnd
[4] = scmd
->sdb
.length
;
953 scmd
->cmd_len
= COMMAND_SIZE(scmd
->cmnd
[0]);
955 scmd
->sc_data_direction
= DMA_NONE
;
957 BUG_ON(cmnd_size
> BLK_MAX_CDB
);
958 memcpy(scmd
->cmnd
, cmnd
, cmnd_size
);
959 scmd
->cmd_len
= COMMAND_SIZE(scmd
->cmnd
[0]);
965 if (sdev
->scsi_level
<= SCSI_2
&& sdev
->scsi_level
!= SCSI_UNKNOWN
)
966 scmd
->cmnd
[1] = (scmd
->cmnd
[1] & 0x1f) |
967 (sdev
->lun
<< 5 & 0xe0);
970 * Zero the sense buffer. The scsi spec mandates that any
971 * untransferred sense data should be interpreted as being zero.
973 memset(scmd
->sense_buffer
, 0, SCSI_SENSE_BUFFERSIZE
);
975 EXPORT_SYMBOL(scsi_eh_prep_cmnd
);
978 * scsi_eh_restore_cmnd - Restore a scsi command info as part of error recovery
979 * @scmd: SCSI command structure to restore
980 * @ses: saved information from a coresponding call to scsi_eh_prep_cmnd
982 * Undo any damage done by above scsi_eh_prep_cmnd().
984 void scsi_eh_restore_cmnd(struct scsi_cmnd
* scmd
, struct scsi_eh_save
*ses
)
987 * Restore original data
989 scmd
->cmd_len
= ses
->cmd_len
;
990 scmd
->cmnd
= ses
->cmnd
;
991 scmd
->sc_data_direction
= ses
->data_direction
;
992 scmd
->sdb
= ses
->sdb
;
993 scmd
->request
->next_rq
= ses
->next_rq
;
994 scmd
->result
= ses
->result
;
995 scmd
->underflow
= ses
->underflow
;
996 scmd
->prot_op
= ses
->prot_op
;
998 EXPORT_SYMBOL(scsi_eh_restore_cmnd
);
1001 * scsi_send_eh_cmnd - submit a scsi command as part of error recovery
1002 * @scmd: SCSI command structure to hijack
1003 * @cmnd: CDB to send
1004 * @cmnd_size: size in bytes of @cmnd
1005 * @timeout: timeout for this request
1006 * @sense_bytes: size of sense data to copy or 0
1008 * This function is used to send a scsi command down to a target device
1009 * as part of the error recovery process. See also scsi_eh_prep_cmnd() above.
1012 * SUCCESS or FAILED or NEEDS_RETRY
1014 static int scsi_send_eh_cmnd(struct scsi_cmnd
*scmd
, unsigned char *cmnd
,
1015 int cmnd_size
, int timeout
, unsigned sense_bytes
)
1017 struct scsi_device
*sdev
= scmd
->device
;
1018 struct Scsi_Host
*shost
= sdev
->host
;
1019 DECLARE_COMPLETION_ONSTACK(done
);
1020 unsigned long timeleft
= timeout
;
1021 struct scsi_eh_save ses
;
1022 const unsigned long stall_for
= msecs_to_jiffies(100);
1026 scsi_eh_prep_cmnd(scmd
, &ses
, cmnd
, cmnd_size
, sense_bytes
);
1027 shost
->eh_action
= &done
;
1029 scsi_log_send(scmd
);
1030 scmd
->scsi_done
= scsi_eh_done
;
1031 rtn
= shost
->hostt
->queuecommand(shost
, scmd
);
1033 if (timeleft
> stall_for
) {
1034 scsi_eh_restore_cmnd(scmd
, &ses
);
1035 timeleft
-= stall_for
;
1036 msleep(jiffies_to_msecs(stall_for
));
1039 /* signal not to enter either branch of the if () below */
1043 timeleft
= wait_for_completion_timeout(&done
, timeout
);
1047 shost
->eh_action
= NULL
;
1049 scsi_log_completion(scmd
, rtn
);
1051 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO
, scmd
,
1052 "%s timeleft: %ld\n",
1053 __func__
, timeleft
));
1056 * If there is time left scsi_eh_done got called, and we will examine
1057 * the actual status codes to see whether the command actually did
1058 * complete normally, else if we have a zero return and no time left,
1059 * the command must still be pending, so abort it and return FAILED.
1060 * If we never actually managed to issue the command, because
1061 * ->queuecommand() kept returning non zero, use the rtn = FAILED
1062 * value above (so don't execute either branch of the if)
1065 rtn
= scsi_eh_completed_normally(scmd
);
1066 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO
, scmd
,
1067 "%s: scsi_eh_completed_normally %x\n", __func__
, rtn
));
1074 case ADD_TO_MLQUEUE
:
1081 } else if (rtn
!= FAILED
) {
1082 scsi_abort_eh_cmnd(scmd
);
1086 scsi_eh_restore_cmnd(scmd
, &ses
);
1092 * scsi_request_sense - Request sense data from a particular target.
1093 * @scmd: SCSI cmd for request sense.
1096 * Some hosts automatically obtain this information, others require
1097 * that we obtain it on our own. This function will *not* return until
1098 * the command either times out, or it completes.
1100 static int scsi_request_sense(struct scsi_cmnd
*scmd
)
1102 return scsi_send_eh_cmnd(scmd
, NULL
, 0, scmd
->device
->eh_timeout
, ~0);
1105 static int scsi_eh_action(struct scsi_cmnd
*scmd
, int rtn
)
1107 if (scmd
->request
->cmd_type
!= REQ_TYPE_BLOCK_PC
) {
1108 struct scsi_driver
*sdrv
= scsi_cmd_to_driver(scmd
);
1109 if (sdrv
->eh_action
)
1110 rtn
= sdrv
->eh_action(scmd
, rtn
);
1116 * scsi_eh_finish_cmd - Handle a cmd that eh is finished with.
1117 * @scmd: Original SCSI cmd that eh has finished.
1118 * @done_q: Queue for processed commands.
1121 * We don't want to use the normal command completion while we are are
1122 * still handling errors - it may cause other commands to be queued,
1123 * and that would disturb what we are doing. Thus we really want to
1124 * keep a list of pending commands for final completion, and once we
1125 * are ready to leave error handling we handle completion for real.
1127 void scsi_eh_finish_cmd(struct scsi_cmnd
*scmd
, struct list_head
*done_q
)
1129 scmd
->device
->host
->host_failed
--;
1130 scmd
->eh_eflags
= 0;
1131 list_move_tail(&scmd
->eh_entry
, done_q
);
1133 EXPORT_SYMBOL(scsi_eh_finish_cmd
);
1136 * scsi_eh_get_sense - Get device sense data.
1137 * @work_q: Queue of commands to process.
1138 * @done_q: Queue of processed commands.
1141 * See if we need to request sense information. if so, then get it
1142 * now, so we have a better idea of what to do.
1145 * This has the unfortunate side effect that if a shost adapter does
1146 * not automatically request sense information, we end up shutting
1147 * it down before we request it.
1149 * All drivers should request sense information internally these days,
1150 * so for now all I have to say is tough noogies if you end up in here.
1152 * XXX: Long term this code should go away, but that needs an audit of
1155 int scsi_eh_get_sense(struct list_head
*work_q
,
1156 struct list_head
*done_q
)
1158 struct scsi_cmnd
*scmd
, *next
;
1159 struct Scsi_Host
*shost
;
1163 * If SCSI_EH_ABORT_SCHEDULED has been set, it is timeout IO,
1164 * should not get sense.
1166 list_for_each_entry_safe(scmd
, next
, work_q
, eh_entry
) {
1167 if ((scmd
->eh_eflags
& SCSI_EH_CANCEL_CMD
) ||
1168 (scmd
->eh_eflags
& SCSI_EH_ABORT_SCHEDULED
) ||
1169 SCSI_SENSE_VALID(scmd
))
1172 shost
= scmd
->device
->host
;
1173 if (scsi_host_eh_past_deadline(shost
)) {
1174 SCSI_LOG_ERROR_RECOVERY(3,
1175 scmd_printk(KERN_INFO
, scmd
,
1176 "%s: skip request sense, past eh deadline\n",
1180 if (status_byte(scmd
->result
) != CHECK_CONDITION
)
1182 * don't request sense if there's no check condition
1183 * status because the error we're processing isn't one
1184 * that has a sense code (and some devices get
1185 * confused by sense requests out of the blue)
1189 SCSI_LOG_ERROR_RECOVERY(2, scmd_printk(KERN_INFO
, scmd
,
1190 "%s: requesting sense\n",
1192 rtn
= scsi_request_sense(scmd
);
1196 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO
, scmd
,
1197 "sense requested, result %x\n", scmd
->result
));
1198 SCSI_LOG_ERROR_RECOVERY(3, scsi_print_sense(scmd
));
1200 rtn
= scsi_decide_disposition(scmd
);
1203 * if the result was normal, then just pass it along to the
1207 /* we don't want this command reissued, just
1208 * finished with the sense data, so set
1209 * retries to the max allowed to ensure it
1210 * won't get reissued */
1211 scmd
->retries
= scmd
->allowed
;
1212 else if (rtn
!= NEEDS_RETRY
)
1215 scsi_eh_finish_cmd(scmd
, done_q
);
1218 return list_empty(work_q
);
1220 EXPORT_SYMBOL_GPL(scsi_eh_get_sense
);
1223 * scsi_eh_tur - Send TUR to device.
1224 * @scmd: &scsi_cmnd to send TUR
1227 * 0 - Device is ready. 1 - Device NOT ready.
1229 static int scsi_eh_tur(struct scsi_cmnd
*scmd
)
1231 static unsigned char tur_command
[6] = {TEST_UNIT_READY
, 0, 0, 0, 0, 0};
1232 int retry_cnt
= 1, rtn
;
1235 rtn
= scsi_send_eh_cmnd(scmd
, tur_command
, 6,
1236 scmd
->device
->eh_timeout
, 0);
1238 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO
, scmd
,
1239 "%s return: %x\n", __func__
, rtn
));
1254 * scsi_eh_test_devices - check if devices are responding from error recovery.
1255 * @cmd_list: scsi commands in error recovery.
1256 * @work_q: queue for commands which still need more error recovery
1257 * @done_q: queue for commands which are finished
1258 * @try_stu: boolean on if a STU command should be tried in addition to TUR.
1261 * Tests if devices are in a working state. Commands to devices now in
1262 * a working state are sent to the done_q while commands to devices which
1263 * are still failing to respond are returned to the work_q for more
1266 static int scsi_eh_test_devices(struct list_head
*cmd_list
,
1267 struct list_head
*work_q
,
1268 struct list_head
*done_q
, int try_stu
)
1270 struct scsi_cmnd
*scmd
, *next
;
1271 struct scsi_device
*sdev
;
1274 while (!list_empty(cmd_list
)) {
1275 scmd
= list_entry(cmd_list
->next
, struct scsi_cmnd
, eh_entry
);
1276 sdev
= scmd
->device
;
1279 if (scsi_host_eh_past_deadline(sdev
->host
)) {
1280 /* Push items back onto work_q */
1281 list_splice_init(cmd_list
, work_q
);
1282 SCSI_LOG_ERROR_RECOVERY(3,
1283 sdev_printk(KERN_INFO
, sdev
,
1284 "%s: skip test device, past eh deadline",
1290 finish_cmds
= !scsi_device_online(scmd
->device
) ||
1291 (try_stu
&& !scsi_eh_try_stu(scmd
) &&
1292 !scsi_eh_tur(scmd
)) ||
1295 list_for_each_entry_safe(scmd
, next
, cmd_list
, eh_entry
)
1296 if (scmd
->device
== sdev
) {
1299 scsi_eh_action(scmd
, SUCCESS
) == SUCCESS
))
1300 scsi_eh_finish_cmd(scmd
, done_q
);
1302 list_move_tail(&scmd
->eh_entry
, work_q
);
1305 return list_empty(work_q
);
1310 * scsi_eh_abort_cmds - abort pending commands.
1311 * @work_q: &list_head for pending commands.
1312 * @done_q: &list_head for processed commands.
1315 * Try and see whether or not it makes sense to try and abort the
1316 * running command. This only works out to be the case if we have one
1317 * command that has timed out. If the command simply failed, it makes
1318 * no sense to try and abort the command, since as far as the shost
1319 * adapter is concerned, it isn't running.
1321 static int scsi_eh_abort_cmds(struct list_head
*work_q
,
1322 struct list_head
*done_q
)
1324 struct scsi_cmnd
*scmd
, *next
;
1325 LIST_HEAD(check_list
);
1327 struct Scsi_Host
*shost
;
1329 list_for_each_entry_safe(scmd
, next
, work_q
, eh_entry
) {
1330 if (!(scmd
->eh_eflags
& SCSI_EH_CANCEL_CMD
))
1332 shost
= scmd
->device
->host
;
1333 if (scsi_host_eh_past_deadline(shost
)) {
1334 list_splice_init(&check_list
, work_q
);
1335 SCSI_LOG_ERROR_RECOVERY(3,
1336 scmd_printk(KERN_INFO
, scmd
,
1337 "%s: skip aborting cmd, past eh deadline\n",
1339 return list_empty(work_q
);
1341 SCSI_LOG_ERROR_RECOVERY(3,
1342 scmd_printk(KERN_INFO
, scmd
,
1343 "%s: aborting cmd\n", current
->comm
));
1344 rtn
= scsi_try_to_abort_cmd(shost
->hostt
, scmd
);
1345 if (rtn
== FAILED
) {
1346 SCSI_LOG_ERROR_RECOVERY(3,
1347 scmd_printk(KERN_INFO
, scmd
,
1348 "%s: aborting cmd failed\n",
1350 list_splice_init(&check_list
, work_q
);
1351 return list_empty(work_q
);
1353 scmd
->eh_eflags
&= ~SCSI_EH_CANCEL_CMD
;
1354 if (rtn
== FAST_IO_FAIL
)
1355 scsi_eh_finish_cmd(scmd
, done_q
);
1357 list_move_tail(&scmd
->eh_entry
, &check_list
);
1360 return scsi_eh_test_devices(&check_list
, work_q
, done_q
, 0);
1364 * scsi_eh_try_stu - Send START_UNIT to device.
1365 * @scmd: &scsi_cmnd to send START_UNIT
1368 * 0 - Device is ready. 1 - Device NOT ready.
1370 static int scsi_eh_try_stu(struct scsi_cmnd
*scmd
)
1372 static unsigned char stu_command
[6] = {START_STOP
, 0, 0, 0, 1, 0};
1374 if (scmd
->device
->allow_restart
) {
1375 int i
, rtn
= NEEDS_RETRY
;
1377 for (i
= 0; rtn
== NEEDS_RETRY
&& i
< 2; i
++)
1378 rtn
= scsi_send_eh_cmnd(scmd
, stu_command
, 6, scmd
->device
->request_queue
->rq_timeout
, 0);
1388 * scsi_eh_stu - send START_UNIT if needed
1389 * @shost: &scsi host being recovered.
1390 * @work_q: &list_head for pending commands.
1391 * @done_q: &list_head for processed commands.
1394 * If commands are failing due to not ready, initializing command required,
1395 * try revalidating the device, which will end up sending a start unit.
1397 static int scsi_eh_stu(struct Scsi_Host
*shost
,
1398 struct list_head
*work_q
,
1399 struct list_head
*done_q
)
1401 struct scsi_cmnd
*scmd
, *stu_scmd
, *next
;
1402 struct scsi_device
*sdev
;
1404 shost_for_each_device(sdev
, shost
) {
1405 if (scsi_host_eh_past_deadline(shost
)) {
1406 SCSI_LOG_ERROR_RECOVERY(3,
1407 sdev_printk(KERN_INFO
, sdev
,
1408 "%s: skip START_UNIT, past eh deadline\n",
1413 list_for_each_entry(scmd
, work_q
, eh_entry
)
1414 if (scmd
->device
== sdev
&& SCSI_SENSE_VALID(scmd
) &&
1415 scsi_check_sense(scmd
) == FAILED
) {
1423 SCSI_LOG_ERROR_RECOVERY(3,
1424 sdev_printk(KERN_INFO
, sdev
,
1425 "%s: Sending START_UNIT\n",
1428 if (!scsi_eh_try_stu(stu_scmd
)) {
1429 if (!scsi_device_online(sdev
) ||
1430 !scsi_eh_tur(stu_scmd
)) {
1431 list_for_each_entry_safe(scmd
, next
,
1433 if (scmd
->device
== sdev
&&
1434 scsi_eh_action(scmd
, SUCCESS
) == SUCCESS
)
1435 scsi_eh_finish_cmd(scmd
, done_q
);
1439 SCSI_LOG_ERROR_RECOVERY(3,
1440 sdev_printk(KERN_INFO
, sdev
,
1441 "%s: START_UNIT failed\n",
1446 return list_empty(work_q
);
1451 * scsi_eh_bus_device_reset - send bdr if needed
1452 * @shost: scsi host being recovered.
1453 * @work_q: &list_head for pending commands.
1454 * @done_q: &list_head for processed commands.
1457 * Try a bus device reset. Still, look to see whether we have multiple
1458 * devices that are jammed or not - if we have multiple devices, it
1459 * makes no sense to try bus_device_reset - we really would need to try
1460 * a bus_reset instead.
1462 static int scsi_eh_bus_device_reset(struct Scsi_Host
*shost
,
1463 struct list_head
*work_q
,
1464 struct list_head
*done_q
)
1466 struct scsi_cmnd
*scmd
, *bdr_scmd
, *next
;
1467 struct scsi_device
*sdev
;
1470 shost_for_each_device(sdev
, shost
) {
1471 if (scsi_host_eh_past_deadline(shost
)) {
1472 SCSI_LOG_ERROR_RECOVERY(3,
1473 sdev_printk(KERN_INFO
, sdev
,
1474 "%s: skip BDR, past eh deadline\n",
1479 list_for_each_entry(scmd
, work_q
, eh_entry
)
1480 if (scmd
->device
== sdev
) {
1488 SCSI_LOG_ERROR_RECOVERY(3,
1489 sdev_printk(KERN_INFO
, sdev
,
1490 "%s: Sending BDR\n", current
->comm
));
1491 rtn
= scsi_try_bus_device_reset(bdr_scmd
);
1492 if (rtn
== SUCCESS
|| rtn
== FAST_IO_FAIL
) {
1493 if (!scsi_device_online(sdev
) ||
1494 rtn
== FAST_IO_FAIL
||
1495 !scsi_eh_tur(bdr_scmd
)) {
1496 list_for_each_entry_safe(scmd
, next
,
1498 if (scmd
->device
== sdev
&&
1499 scsi_eh_action(scmd
, rtn
) != FAILED
)
1500 scsi_eh_finish_cmd(scmd
,
1505 SCSI_LOG_ERROR_RECOVERY(3,
1506 sdev_printk(KERN_INFO
, sdev
,
1507 "%s: BDR failed\n", current
->comm
));
1511 return list_empty(work_q
);
1515 * scsi_eh_target_reset - send target reset if needed
1516 * @shost: scsi host being recovered.
1517 * @work_q: &list_head for pending commands.
1518 * @done_q: &list_head for processed commands.
1521 * Try a target reset.
1523 static int scsi_eh_target_reset(struct Scsi_Host
*shost
,
1524 struct list_head
*work_q
,
1525 struct list_head
*done_q
)
1527 LIST_HEAD(tmp_list
);
1528 LIST_HEAD(check_list
);
1530 list_splice_init(work_q
, &tmp_list
);
1532 while (!list_empty(&tmp_list
)) {
1533 struct scsi_cmnd
*next
, *scmd
;
1537 if (scsi_host_eh_past_deadline(shost
)) {
1538 /* push back on work queue for further processing */
1539 list_splice_init(&check_list
, work_q
);
1540 list_splice_init(&tmp_list
, work_q
);
1541 SCSI_LOG_ERROR_RECOVERY(3,
1542 shost_printk(KERN_INFO
, shost
,
1543 "%s: Skip target reset, past eh deadline\n",
1545 return list_empty(work_q
);
1548 scmd
= list_entry(tmp_list
.next
, struct scsi_cmnd
, eh_entry
);
1551 SCSI_LOG_ERROR_RECOVERY(3,
1552 shost_printk(KERN_INFO
, shost
,
1553 "%s: Sending target reset to target %d\n",
1554 current
->comm
, id
));
1555 rtn
= scsi_try_target_reset(scmd
);
1556 if (rtn
!= SUCCESS
&& rtn
!= FAST_IO_FAIL
)
1557 SCSI_LOG_ERROR_RECOVERY(3,
1558 shost_printk(KERN_INFO
, shost
,
1559 "%s: Target reset failed"
1561 current
->comm
, id
));
1562 list_for_each_entry_safe(scmd
, next
, &tmp_list
, eh_entry
) {
1563 if (scmd_id(scmd
) != id
)
1567 list_move_tail(&scmd
->eh_entry
, &check_list
);
1568 else if (rtn
== FAST_IO_FAIL
)
1569 scsi_eh_finish_cmd(scmd
, done_q
);
1571 /* push back on work queue for further processing */
1572 list_move(&scmd
->eh_entry
, work_q
);
1576 return scsi_eh_test_devices(&check_list
, work_q
, done_q
, 0);
1580 * scsi_eh_bus_reset - send a bus reset
1581 * @shost: &scsi host being recovered.
1582 * @work_q: &list_head for pending commands.
1583 * @done_q: &list_head for processed commands.
1585 static int scsi_eh_bus_reset(struct Scsi_Host
*shost
,
1586 struct list_head
*work_q
,
1587 struct list_head
*done_q
)
1589 struct scsi_cmnd
*scmd
, *chan_scmd
, *next
;
1590 LIST_HEAD(check_list
);
1591 unsigned int channel
;
1595 * we really want to loop over the various channels, and do this on
1596 * a channel by channel basis. we should also check to see if any
1597 * of the failed commands are on soft_reset devices, and if so, skip
1601 for (channel
= 0; channel
<= shost
->max_channel
; channel
++) {
1602 if (scsi_host_eh_past_deadline(shost
)) {
1603 list_splice_init(&check_list
, work_q
);
1604 SCSI_LOG_ERROR_RECOVERY(3,
1605 shost_printk(KERN_INFO
, shost
,
1606 "%s: skip BRST, past eh deadline\n",
1608 return list_empty(work_q
);
1612 list_for_each_entry(scmd
, work_q
, eh_entry
) {
1613 if (channel
== scmd_channel(scmd
)) {
1617 * FIXME add back in some support for
1618 * soft_reset devices.
1625 SCSI_LOG_ERROR_RECOVERY(3,
1626 shost_printk(KERN_INFO
, shost
,
1627 "%s: Sending BRST chan: %d\n",
1628 current
->comm
, channel
));
1629 rtn
= scsi_try_bus_reset(chan_scmd
);
1630 if (rtn
== SUCCESS
|| rtn
== FAST_IO_FAIL
) {
1631 list_for_each_entry_safe(scmd
, next
, work_q
, eh_entry
) {
1632 if (channel
== scmd_channel(scmd
)) {
1633 if (rtn
== FAST_IO_FAIL
)
1634 scsi_eh_finish_cmd(scmd
,
1637 list_move_tail(&scmd
->eh_entry
,
1642 SCSI_LOG_ERROR_RECOVERY(3,
1643 shost_printk(KERN_INFO
, shost
,
1644 "%s: BRST failed chan: %d\n",
1645 current
->comm
, channel
));
1648 return scsi_eh_test_devices(&check_list
, work_q
, done_q
, 0);
1652 * scsi_eh_host_reset - send a host reset
1653 * @shost: host to be reset.
1654 * @work_q: &list_head for pending commands.
1655 * @done_q: &list_head for processed commands.
1657 static int scsi_eh_host_reset(struct Scsi_Host
*shost
,
1658 struct list_head
*work_q
,
1659 struct list_head
*done_q
)
1661 struct scsi_cmnd
*scmd
, *next
;
1662 LIST_HEAD(check_list
);
1665 if (!list_empty(work_q
)) {
1666 scmd
= list_entry(work_q
->next
,
1667 struct scsi_cmnd
, eh_entry
);
1669 SCSI_LOG_ERROR_RECOVERY(3,
1670 shost_printk(KERN_INFO
, shost
,
1671 "%s: Sending HRST\n",
1674 rtn
= scsi_try_host_reset(scmd
);
1675 if (rtn
== SUCCESS
) {
1676 list_splice_init(work_q
, &check_list
);
1677 } else if (rtn
== FAST_IO_FAIL
) {
1678 list_for_each_entry_safe(scmd
, next
, work_q
, eh_entry
) {
1679 scsi_eh_finish_cmd(scmd
, done_q
);
1682 SCSI_LOG_ERROR_RECOVERY(3,
1683 shost_printk(KERN_INFO
, shost
,
1684 "%s: HRST failed\n",
1688 return scsi_eh_test_devices(&check_list
, work_q
, done_q
, 1);
1692 * scsi_eh_offline_sdevs - offline scsi devices that fail to recover
1693 * @work_q: &list_head for pending commands.
1694 * @done_q: &list_head for processed commands.
1696 static void scsi_eh_offline_sdevs(struct list_head
*work_q
,
1697 struct list_head
*done_q
)
1699 struct scsi_cmnd
*scmd
, *next
;
1701 list_for_each_entry_safe(scmd
, next
, work_q
, eh_entry
) {
1702 sdev_printk(KERN_INFO
, scmd
->device
, "Device offlined - "
1703 "not ready after error recovery\n");
1704 scsi_device_set_state(scmd
->device
, SDEV_OFFLINE
);
1705 if (scmd
->eh_eflags
& SCSI_EH_CANCEL_CMD
) {
1707 * FIXME: Handle lost cmds.
1710 scsi_eh_finish_cmd(scmd
, done_q
);
1716 * scsi_noretry_cmd - determine if command should be failed fast
1717 * @scmd: SCSI cmd to examine.
1719 int scsi_noretry_cmd(struct scsi_cmnd
*scmd
)
1721 switch (host_byte(scmd
->result
)) {
1727 return (scmd
->request
->cmd_flags
& REQ_FAILFAST_TRANSPORT
);
1729 return (scmd
->request
->cmd_flags
& REQ_FAILFAST_DEV
);
1731 if (msg_byte(scmd
->result
) == COMMAND_COMPLETE
&&
1732 status_byte(scmd
->result
) == RESERVATION_CONFLICT
)
1735 case DID_SOFT_ERROR
:
1736 return (scmd
->request
->cmd_flags
& REQ_FAILFAST_DRIVER
);
1739 if (status_byte(scmd
->result
) != CHECK_CONDITION
)
1744 * assume caller has checked sense and determined
1745 * the check condition was retryable.
1747 if (scmd
->request
->cmd_flags
& REQ_FAILFAST_DEV
||
1748 scmd
->request
->cmd_type
== REQ_TYPE_BLOCK_PC
)
1755 * scsi_decide_disposition - Disposition a cmd on return from LLD.
1756 * @scmd: SCSI cmd to examine.
1759 * This is *only* called when we are examining the status after sending
1760 * out the actual data command. any commands that are queued for error
1761 * recovery (e.g. test_unit_ready) do *not* come through here.
1763 * When this routine returns failed, it means the error handler thread
1764 * is woken. In cases where the error code indicates an error that
1765 * doesn't require the error handler read (i.e. we don't need to
1766 * abort/reset), this function should return SUCCESS.
1768 int scsi_decide_disposition(struct scsi_cmnd
*scmd
)
1773 * if the device is offline, then we clearly just pass the result back
1774 * up to the top level.
1776 if (!scsi_device_online(scmd
->device
)) {
1777 SCSI_LOG_ERROR_RECOVERY(5, scmd_printk(KERN_INFO
, scmd
,
1778 "%s: device offline - report as SUCCESS\n", __func__
));
1783 * first check the host byte, to see if there is anything in there
1784 * that would indicate what we need to do.
1786 switch (host_byte(scmd
->result
)) {
1787 case DID_PASSTHROUGH
:
1789 * no matter what, pass this through to the upper layer.
1790 * nuke this special code so that it looks like we are saying
1793 scmd
->result
&= 0xff00ffff;
1797 * looks good. drop through, and check the next byte.
1801 if (scmd
->eh_eflags
& SCSI_EH_ABORT_SCHEDULED
) {
1802 set_host_byte(scmd
, DID_TIME_OUT
);
1805 case DID_NO_CONNECT
:
1806 case DID_BAD_TARGET
:
1808 * note - this means that we just report the status back
1809 * to the top level driver, not that we actually think
1810 * that it indicates SUCCESS.
1814 * when the low level driver returns did_soft_error,
1815 * it is responsible for keeping an internal retry counter
1816 * in order to avoid endless loops (db)
1818 * actually this is a bug in this function here. we should
1819 * be mindful of the maximum number of retries specified
1820 * and not get stuck in a loop.
1822 case DID_SOFT_ERROR
:
1828 return ADD_TO_MLQUEUE
;
1829 case DID_TRANSPORT_DISRUPTED
:
1831 * LLD/transport was disrupted during processing of the IO.
1832 * The transport class is now blocked/blocking,
1833 * and the transport will decide what to do with the IO
1834 * based on its timers and recovery capablilities if
1835 * there are enough retries.
1838 case DID_TRANSPORT_FAILFAST
:
1840 * The transport decided to failfast the IO (most likely
1841 * the fast io fail tmo fired), so send IO directly upwards.
1845 if (msg_byte(scmd
->result
) == COMMAND_COMPLETE
&&
1846 status_byte(scmd
->result
) == RESERVATION_CONFLICT
)
1848 * execute reservation conflict processing code
1858 * when we scan the bus, we get timeout messages for
1859 * these commands if there is no device available.
1860 * other hosts report did_no_connect for the same thing.
1862 if ((scmd
->cmnd
[0] == TEST_UNIT_READY
||
1863 scmd
->cmnd
[0] == INQUIRY
)) {
1875 * next, check the message byte.
1877 if (msg_byte(scmd
->result
) != COMMAND_COMPLETE
)
1881 * check the status byte to see if this indicates anything special.
1883 switch (status_byte(scmd
->result
)) {
1885 scsi_handle_queue_full(scmd
->device
);
1887 * the case of trying to send too many commands to a
1888 * tagged queueing device.
1892 * device can't talk to us at the moment. Should only
1893 * occur (SAM-3) when the task queue is empty, so will cause
1894 * the empty queue handling to trigger a stall in the
1897 return ADD_TO_MLQUEUE
;
1899 if (scmd
->cmnd
[0] == REPORT_LUNS
)
1900 scmd
->device
->sdev_target
->expecting_lun_change
= 0;
1901 scsi_handle_queue_ramp_up(scmd
->device
);
1902 case COMMAND_TERMINATED
:
1906 case CHECK_CONDITION
:
1907 rtn
= scsi_check_sense(scmd
);
1908 if (rtn
== NEEDS_RETRY
)
1910 /* if rtn == FAILED, we have no sense information;
1911 * returning FAILED will wake the error handler thread
1912 * to collect the sense and redo the decide
1915 case CONDITION_GOOD
:
1916 case INTERMEDIATE_GOOD
:
1917 case INTERMEDIATE_C_GOOD
:
1920 * who knows? FIXME(eric)
1924 case RESERVATION_CONFLICT
:
1925 sdev_printk(KERN_INFO
, scmd
->device
,
1926 "reservation conflict\n");
1927 set_host_byte(scmd
, DID_NEXUS_FAILURE
);
1928 return SUCCESS
; /* causes immediate i/o error */
1936 /* we requeue for retry because the error was retryable, and
1937 * the request was not marked fast fail. Note that above,
1938 * even if the request is marked fast fail, we still requeue
1939 * for queue congestion conditions (QUEUE_FULL or BUSY) */
1940 if ((++scmd
->retries
) <= scmd
->allowed
1941 && !scsi_noretry_cmd(scmd
)) {
1945 * no more retries - report this one back to upper level.
1951 static void eh_lock_door_done(struct request
*req
, int uptodate
)
1953 __blk_put_request(req
->q
, req
);
1957 * scsi_eh_lock_door - Prevent medium removal for the specified device
1958 * @sdev: SCSI device to prevent medium removal
1961 * We must be called from process context.
1964 * We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the
1965 * head of the devices request queue, and continue.
1967 static void scsi_eh_lock_door(struct scsi_device
*sdev
)
1969 struct request
*req
;
1972 * blk_get_request with GFP_KERNEL (__GFP_WAIT) sleeps until a
1973 * request becomes available
1975 req
= blk_get_request(sdev
->request_queue
, READ
, GFP_KERNEL
);
1979 blk_rq_set_block_pc(req
);
1981 req
->cmd
[0] = ALLOW_MEDIUM_REMOVAL
;
1985 req
->cmd
[4] = SCSI_REMOVAL_PREVENT
;
1988 req
->cmd_len
= COMMAND_SIZE(req
->cmd
[0]);
1990 req
->cmd_flags
|= REQ_QUIET
;
1991 req
->timeout
= 10 * HZ
;
1994 blk_execute_rq_nowait(req
->q
, NULL
, req
, 1, eh_lock_door_done
);
1998 * scsi_restart_operations - restart io operations to the specified host.
1999 * @shost: Host we are restarting.
2002 * When we entered the error handler, we blocked all further i/o to
2003 * this device. we need to 'reverse' this process.
2005 static void scsi_restart_operations(struct Scsi_Host
*shost
)
2007 struct scsi_device
*sdev
;
2008 unsigned long flags
;
2011 * If the door was locked, we need to insert a door lock request
2012 * onto the head of the SCSI request queue for the device. There
2013 * is no point trying to lock the door of an off-line device.
2015 shost_for_each_device(sdev
, shost
) {
2016 if (scsi_device_online(sdev
) && sdev
->was_reset
&& sdev
->locked
) {
2017 scsi_eh_lock_door(sdev
);
2018 sdev
->was_reset
= 0;
2023 * next free up anything directly waiting upon the host. this
2024 * will be requests for character device operations, and also for
2025 * ioctls to queued block devices.
2027 SCSI_LOG_ERROR_RECOVERY(3,
2028 shost_printk(KERN_INFO
, shost
, "waking up host to restart\n"));
2030 spin_lock_irqsave(shost
->host_lock
, flags
);
2031 if (scsi_host_set_state(shost
, SHOST_RUNNING
))
2032 if (scsi_host_set_state(shost
, SHOST_CANCEL
))
2033 BUG_ON(scsi_host_set_state(shost
, SHOST_DEL
));
2034 spin_unlock_irqrestore(shost
->host_lock
, flags
);
2036 wake_up(&shost
->host_wait
);
2039 * finally we need to re-initiate requests that may be pending. we will
2040 * have had everything blocked while error handling is taking place, and
2041 * now that error recovery is done, we will need to ensure that these
2042 * requests are started.
2044 scsi_run_host_queues(shost
);
2047 * if eh is active and host_eh_scheduled is pending we need to re-run
2048 * recovery. we do this check after scsi_run_host_queues() to allow
2049 * everything pent up since the last eh run a chance to make forward
2050 * progress before we sync again. Either we'll immediately re-run
2051 * recovery or scsi_device_unbusy() will wake us again when these
2052 * pending commands complete.
2054 spin_lock_irqsave(shost
->host_lock
, flags
);
2055 if (shost
->host_eh_scheduled
)
2056 if (scsi_host_set_state(shost
, SHOST_RECOVERY
))
2057 WARN_ON(scsi_host_set_state(shost
, SHOST_CANCEL_RECOVERY
));
2058 spin_unlock_irqrestore(shost
->host_lock
, flags
);
2062 * scsi_eh_ready_devs - check device ready state and recover if not.
2063 * @shost: host to be recovered.
2064 * @work_q: &list_head for pending commands.
2065 * @done_q: &list_head for processed commands.
2067 void scsi_eh_ready_devs(struct Scsi_Host
*shost
,
2068 struct list_head
*work_q
,
2069 struct list_head
*done_q
)
2071 if (!scsi_eh_stu(shost
, work_q
, done_q
))
2072 if (!scsi_eh_bus_device_reset(shost
, work_q
, done_q
))
2073 if (!scsi_eh_target_reset(shost
, work_q
, done_q
))
2074 if (!scsi_eh_bus_reset(shost
, work_q
, done_q
))
2075 if (!scsi_eh_host_reset(shost
, work_q
, done_q
))
2076 scsi_eh_offline_sdevs(work_q
,
2079 EXPORT_SYMBOL_GPL(scsi_eh_ready_devs
);
2082 * scsi_eh_flush_done_q - finish processed commands or retry them.
2083 * @done_q: list_head of processed commands.
2085 void scsi_eh_flush_done_q(struct list_head
*done_q
)
2087 struct scsi_cmnd
*scmd
, *next
;
2089 list_for_each_entry_safe(scmd
, next
, done_q
, eh_entry
) {
2090 list_del_init(&scmd
->eh_entry
);
2091 if (scsi_device_online(scmd
->device
) &&
2092 !scsi_noretry_cmd(scmd
) &&
2093 (++scmd
->retries
<= scmd
->allowed
)) {
2094 SCSI_LOG_ERROR_RECOVERY(3,
2095 scmd_printk(KERN_INFO
, scmd
,
2096 "%s: flush retry cmd\n",
2098 scsi_queue_insert(scmd
, SCSI_MLQUEUE_EH_RETRY
);
2101 * If just we got sense for the device (called
2102 * scsi_eh_get_sense), scmd->result is already
2103 * set, do not set DRIVER_TIMEOUT.
2106 scmd
->result
|= (DRIVER_TIMEOUT
<< 24);
2107 SCSI_LOG_ERROR_RECOVERY(3,
2108 scmd_printk(KERN_INFO
, scmd
,
2109 "%s: flush finish cmd\n",
2111 scsi_finish_command(scmd
);
2115 EXPORT_SYMBOL(scsi_eh_flush_done_q
);
2118 * scsi_unjam_host - Attempt to fix a host which has a cmd that failed.
2119 * @shost: Host to unjam.
2122 * When we come in here, we *know* that all commands on the bus have
2123 * either completed, failed or timed out. we also know that no further
2124 * commands are being sent to the host, so things are relatively quiet
2125 * and we have freedom to fiddle with things as we wish.
2127 * This is only the *default* implementation. it is possible for
2128 * individual drivers to supply their own version of this function, and
2129 * if the maintainer wishes to do this, it is strongly suggested that
2130 * this function be taken as a template and modified. this function
2131 * was designed to correctly handle problems for about 95% of the
2132 * different cases out there, and it should always provide at least a
2133 * reasonable amount of error recovery.
2135 * Any command marked 'failed' or 'timeout' must eventually have
2136 * scsi_finish_cmd() called for it. we do all of the retry stuff
2137 * here, so when we restart the host after we return it should have an
2140 static void scsi_unjam_host(struct Scsi_Host
*shost
)
2142 unsigned long flags
;
2143 LIST_HEAD(eh_work_q
);
2144 LIST_HEAD(eh_done_q
);
2146 spin_lock_irqsave(shost
->host_lock
, flags
);
2147 list_splice_init(&shost
->eh_cmd_q
, &eh_work_q
);
2148 spin_unlock_irqrestore(shost
->host_lock
, flags
);
2150 SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(shost
, &eh_work_q
));
2152 if (!scsi_eh_get_sense(&eh_work_q
, &eh_done_q
))
2153 if (!scsi_eh_abort_cmds(&eh_work_q
, &eh_done_q
))
2154 scsi_eh_ready_devs(shost
, &eh_work_q
, &eh_done_q
);
2156 spin_lock_irqsave(shost
->host_lock
, flags
);
2157 if (shost
->eh_deadline
!= -1)
2158 shost
->last_reset
= 0;
2159 spin_unlock_irqrestore(shost
->host_lock
, flags
);
2160 scsi_eh_flush_done_q(&eh_done_q
);
2164 * scsi_error_handler - SCSI error handler thread
2165 * @data: Host for which we are running.
2168 * This is the main error handling loop. This is run as a kernel thread
2169 * for every SCSI host and handles all error handling activity.
2171 int scsi_error_handler(void *data
)
2173 struct Scsi_Host
*shost
= data
;
2176 * We use TASK_INTERRUPTIBLE so that the thread is not
2177 * counted against the load average as a running process.
2178 * We never actually get interrupted because kthread_run
2179 * disables signal delivery for the created thread.
2181 while (!kthread_should_stop()) {
2182 set_current_state(TASK_INTERRUPTIBLE
);
2183 if ((shost
->host_failed
== 0 && shost
->host_eh_scheduled
== 0) ||
2184 shost
->host_failed
!= atomic_read(&shost
->host_busy
)) {
2185 SCSI_LOG_ERROR_RECOVERY(1,
2186 shost_printk(KERN_INFO
, shost
,
2187 "scsi_eh_%d: sleeping\n",
2193 __set_current_state(TASK_RUNNING
);
2194 SCSI_LOG_ERROR_RECOVERY(1,
2195 shost_printk(KERN_INFO
, shost
,
2196 "scsi_eh_%d: waking up %d/%d/%d\n",
2197 shost
->host_no
, shost
->host_eh_scheduled
,
2199 atomic_read(&shost
->host_busy
)));
2202 * We have a host that is failing for some reason. Figure out
2203 * what we need to do to get it up and online again (if we can).
2204 * If we fail, we end up taking the thing offline.
2206 if (!shost
->eh_noresume
&& scsi_autopm_get_host(shost
) != 0) {
2207 SCSI_LOG_ERROR_RECOVERY(1,
2208 shost_printk(KERN_ERR
, shost
,
2209 "scsi_eh_%d: unable to autoresume\n",
2214 if (shost
->transportt
->eh_strategy_handler
)
2215 shost
->transportt
->eh_strategy_handler(shost
);
2217 scsi_unjam_host(shost
);
2220 * Note - if the above fails completely, the action is to take
2221 * individual devices offline and flush the queue of any
2222 * outstanding requests that may have been pending. When we
2223 * restart, we restart any I/O to any other devices on the bus
2224 * which are still online.
2226 scsi_restart_operations(shost
);
2227 if (!shost
->eh_noresume
)
2228 scsi_autopm_put_host(shost
);
2230 __set_current_state(TASK_RUNNING
);
2232 SCSI_LOG_ERROR_RECOVERY(1,
2233 shost_printk(KERN_INFO
, shost
,
2234 "Error handler scsi_eh_%d exiting\n",
2236 shost
->ehandler
= NULL
;
2241 * Function: scsi_report_bus_reset()
2243 * Purpose: Utility function used by low-level drivers to report that
2244 * they have observed a bus reset on the bus being handled.
2246 * Arguments: shost - Host in question
2247 * channel - channel on which reset was observed.
2251 * Lock status: Host lock must be held.
2253 * Notes: This only needs to be called if the reset is one which
2254 * originates from an unknown location. Resets originated
2255 * by the mid-level itself don't need to call this, but there
2256 * should be no harm.
2258 * The main purpose of this is to make sure that a CHECK_CONDITION
2259 * is properly treated.
2261 void scsi_report_bus_reset(struct Scsi_Host
*shost
, int channel
)
2263 struct scsi_device
*sdev
;
2265 __shost_for_each_device(sdev
, shost
) {
2266 if (channel
== sdev_channel(sdev
))
2267 __scsi_report_device_reset(sdev
, NULL
);
2270 EXPORT_SYMBOL(scsi_report_bus_reset
);
2273 * Function: scsi_report_device_reset()
2275 * Purpose: Utility function used by low-level drivers to report that
2276 * they have observed a device reset on the device being handled.
2278 * Arguments: shost - Host in question
2279 * channel - channel on which reset was observed
2280 * target - target on which reset was observed
2284 * Lock status: Host lock must be held
2286 * Notes: This only needs to be called if the reset is one which
2287 * originates from an unknown location. Resets originated
2288 * by the mid-level itself don't need to call this, but there
2289 * should be no harm.
2291 * The main purpose of this is to make sure that a CHECK_CONDITION
2292 * is properly treated.
2294 void scsi_report_device_reset(struct Scsi_Host
*shost
, int channel
, int target
)
2296 struct scsi_device
*sdev
;
2298 __shost_for_each_device(sdev
, shost
) {
2299 if (channel
== sdev_channel(sdev
) &&
2300 target
== sdev_id(sdev
))
2301 __scsi_report_device_reset(sdev
, NULL
);
2304 EXPORT_SYMBOL(scsi_report_device_reset
);
2307 scsi_reset_provider_done_command(struct scsi_cmnd
*scmd
)
2312 * scsi_ioctl_reset: explicitly reset a host/bus/target/device
2313 * @dev: scsi_device to operate on
2314 * @arg: reset type (see sg.h)
2317 scsi_ioctl_reset(struct scsi_device
*dev
, int __user
*arg
)
2319 struct scsi_cmnd
*scmd
;
2320 struct Scsi_Host
*shost
= dev
->host
;
2322 unsigned long flags
;
2323 int error
= 0, rtn
, val
;
2325 if (!capable(CAP_SYS_ADMIN
) || !capable(CAP_SYS_RAWIO
))
2328 error
= get_user(val
, arg
);
2332 if (scsi_autopm_get_host(shost
) < 0)
2336 scmd
= scsi_get_command(dev
, GFP_KERNEL
);
2338 goto out_put_autopm_host
;
2340 blk_rq_init(NULL
, &req
);
2341 scmd
->request
= &req
;
2343 scmd
->cmnd
= req
.cmd
;
2345 scmd
->scsi_done
= scsi_reset_provider_done_command
;
2346 memset(&scmd
->sdb
, 0, sizeof(scmd
->sdb
));
2350 scmd
->sc_data_direction
= DMA_BIDIRECTIONAL
;
2352 spin_lock_irqsave(shost
->host_lock
, flags
);
2353 shost
->tmf_in_progress
= 1;
2354 spin_unlock_irqrestore(shost
->host_lock
, flags
);
2356 switch (val
& ~SG_SCSI_RESET_NO_ESCALATE
) {
2357 case SG_SCSI_RESET_NOTHING
:
2360 case SG_SCSI_RESET_DEVICE
:
2361 rtn
= scsi_try_bus_device_reset(scmd
);
2362 if (rtn
== SUCCESS
|| (val
& SG_SCSI_RESET_NO_ESCALATE
))
2365 case SG_SCSI_RESET_TARGET
:
2366 rtn
= scsi_try_target_reset(scmd
);
2367 if (rtn
== SUCCESS
|| (val
& SG_SCSI_RESET_NO_ESCALATE
))
2370 case SG_SCSI_RESET_BUS
:
2371 rtn
= scsi_try_bus_reset(scmd
);
2372 if (rtn
== SUCCESS
|| (val
& SG_SCSI_RESET_NO_ESCALATE
))
2375 case SG_SCSI_RESET_HOST
:
2376 rtn
= scsi_try_host_reset(scmd
);
2385 error
= (rtn
== SUCCESS
) ? 0 : -EIO
;
2387 spin_lock_irqsave(shost
->host_lock
, flags
);
2388 shost
->tmf_in_progress
= 0;
2389 spin_unlock_irqrestore(shost
->host_lock
, flags
);
2392 * be sure to wake up anyone who was sleeping or had their queue
2393 * suspended while we performed the TMF.
2395 SCSI_LOG_ERROR_RECOVERY(3,
2396 shost_printk(KERN_INFO
, shost
,
2397 "waking up host to restart after TMF\n"));
2399 wake_up(&shost
->host_wait
);
2400 scsi_run_host_queues(shost
);
2402 scsi_put_command(scmd
);
2404 out_put_autopm_host
:
2405 scsi_autopm_put_host(shost
);
2408 EXPORT_SYMBOL(scsi_ioctl_reset
);
2410 bool scsi_command_normalize_sense(const struct scsi_cmnd
*cmd
,
2411 struct scsi_sense_hdr
*sshdr
)
2413 return scsi_normalize_sense(cmd
->sense_buffer
,
2414 SCSI_SENSE_BUFFERSIZE
, sshdr
);
2416 EXPORT_SYMBOL(scsi_command_normalize_sense
);
2419 * scsi_sense_desc_find - search for a given descriptor type in descriptor sense data format.
2420 * @sense_buffer: byte array of descriptor format sense data
2421 * @sb_len: number of valid bytes in sense_buffer
2422 * @desc_type: value of descriptor type to find
2423 * (e.g. 0 -> information)
2426 * only valid when sense data is in descriptor format
2429 * pointer to start of (first) descriptor if found else NULL
2431 const u8
* scsi_sense_desc_find(const u8
* sense_buffer
, int sb_len
,
2434 int add_sen_len
, add_len
, desc_len
, k
;
2437 if ((sb_len
< 8) || (0 == (add_sen_len
= sense_buffer
[7])))
2439 if ((sense_buffer
[0] < 0x72) || (sense_buffer
[0] > 0x73))
2441 add_sen_len
= (add_sen_len
< (sb_len
- 8)) ?
2442 add_sen_len
: (sb_len
- 8);
2443 descp
= &sense_buffer
[8];
2444 for (desc_len
= 0, k
= 0; k
< add_sen_len
; k
+= desc_len
) {
2446 add_len
= (k
< (add_sen_len
- 1)) ? descp
[1]: -1;
2447 desc_len
= add_len
+ 2;
2448 if (descp
[0] == desc_type
)
2450 if (add_len
< 0) // short descriptor ??
2455 EXPORT_SYMBOL(scsi_sense_desc_find
);
2458 * scsi_get_sense_info_fld - get information field from sense data (either fixed or descriptor format)
2459 * @sense_buffer: byte array of sense data
2460 * @sb_len: number of valid bytes in sense_buffer
2461 * @info_out: pointer to 64 integer where 8 or 4 byte information
2462 * field will be placed if found.
2465 * 1 if information field found, 0 if not found.
2467 int scsi_get_sense_info_fld(const u8
* sense_buffer
, int sb_len
,
2476 switch (sense_buffer
[0] & 0x7f) {
2479 if (sense_buffer
[0] & 0x80) {
2480 *info_out
= (sense_buffer
[3] << 24) +
2481 (sense_buffer
[4] << 16) +
2482 (sense_buffer
[5] << 8) + sense_buffer
[6];
2488 ucp
= scsi_sense_desc_find(sense_buffer
, sb_len
,
2490 if (ucp
&& (0xa == ucp
[1])) {
2492 for (j
= 0; j
< 8; ++j
) {
2505 EXPORT_SYMBOL(scsi_get_sense_info_fld
);
2508 * scsi_build_sense_buffer - build sense data in a buffer
2509 * @desc: Sense format (non zero == descriptor format,
2510 * 0 == fixed format)
2511 * @buf: Where to build sense data
2513 * @asc: Additional sense code
2514 * @ascq: Additional sense code qualifier
2517 void scsi_build_sense_buffer(int desc
, u8
*buf
, u8 key
, u8 asc
, u8 ascq
)
2520 buf
[0] = 0x72; /* descriptor, current */
2526 buf
[0] = 0x70; /* fixed, current */
2533 EXPORT_SYMBOL(scsi_build_sense_buffer
);