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/timer.h>
20 #include <linux/string.h>
21 #include <linux/slab.h>
22 #include <linux/kernel.h>
23 #include <linux/interrupt.h>
24 #include <linux/blkdev.h>
25 #include <linux/delay.h>
27 #include <scsi/scsi.h>
28 #include <scsi/scsi_dbg.h>
29 #include <scsi/scsi_device.h>
30 #include <scsi/scsi_eh.h>
31 #include <scsi/scsi_host.h>
32 #include <scsi/scsi_ioctl.h>
33 #include <scsi/scsi_request.h>
35 #include "scsi_priv.h"
36 #include "scsi_logging.h"
38 #define SENSE_TIMEOUT (10*HZ)
39 #define START_UNIT_TIMEOUT (30*HZ)
42 * These should *probably* be handled by the host itself.
43 * Since it is allowed to sleep, it probably should.
45 #define BUS_RESET_SETTLE_TIME (10)
46 #define HOST_RESET_SETTLE_TIME (10)
48 /* called with shost->host_lock held */
49 void scsi_eh_wakeup(struct Scsi_Host
*shost
)
51 if (shost
->host_busy
== shost
->host_failed
) {
53 SCSI_LOG_ERROR_RECOVERY(5,
54 printk("Waking error handler thread\n"));
59 * scsi_eh_scmd_add - add scsi cmd to error handling.
60 * @scmd: scmd to run eh on.
61 * @eh_flag: optional SCSI_EH flag.
66 int scsi_eh_scmd_add(struct scsi_cmnd
*scmd
, int eh_flag
)
68 struct Scsi_Host
*shost
= scmd
->device
->host
;
71 if (shost
->eh_wait
== NULL
)
74 spin_lock_irqsave(shost
->host_lock
, flags
);
76 scsi_eh_eflags_set(scmd
, eh_flag
);
78 * FIXME: Can we stop setting owner and state.
80 scmd
->owner
= SCSI_OWNER_ERROR_HANDLER
;
81 scmd
->state
= SCSI_STATE_FAILED
;
83 * Set the serial_number_at_timeout to the current
86 scmd
->serial_number_at_timeout
= scmd
->serial_number
;
87 list_add_tail(&scmd
->eh_entry
, &shost
->eh_cmd_q
);
88 set_bit(SHOST_RECOVERY
, &shost
->shost_state
);
90 scsi_eh_wakeup(shost
);
91 spin_unlock_irqrestore(shost
->host_lock
, flags
);
96 * scsi_add_timer - Start timeout timer for a single scsi command.
97 * @scmd: scsi command that is about to start running.
98 * @timeout: amount of time to allow this command to run.
99 * @complete: timeout function to call if timer isn't canceled.
102 * This should be turned into an inline function. Each scsi command
103 * has its own timer, and as it is added to the queue, we set up the
104 * timer. When the command completes, we cancel the timer.
106 void scsi_add_timer(struct scsi_cmnd
*scmd
, int timeout
,
107 void (*complete
)(struct scsi_cmnd
*))
111 * If the clock was already running for this command, then
112 * first delete the timer. The timer handling code gets rather
113 * confused if we don't do this.
115 if (scmd
->eh_timeout
.function
)
116 del_timer(&scmd
->eh_timeout
);
118 scmd
->eh_timeout
.data
= (unsigned long)scmd
;
119 scmd
->eh_timeout
.expires
= jiffies
+ timeout
;
120 scmd
->eh_timeout
.function
= (void (*)(unsigned long)) complete
;
122 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p, time:"
123 " %d, (%p)\n", __FUNCTION__
,
124 scmd
, timeout
, complete
));
126 add_timer(&scmd
->eh_timeout
);
128 EXPORT_SYMBOL(scsi_add_timer
);
131 * scsi_delete_timer - Delete/cancel timer for a given function.
132 * @scmd: Cmd that we are canceling timer for
135 * This should be turned into an inline function.
138 * 1 if we were able to detach the timer. 0 if we blew it, and the
139 * timer function has already started to run.
141 int scsi_delete_timer(struct scsi_cmnd
*scmd
)
145 rtn
= del_timer(&scmd
->eh_timeout
);
147 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p,"
148 " rtn: %d\n", __FUNCTION__
,
151 scmd
->eh_timeout
.data
= (unsigned long)NULL
;
152 scmd
->eh_timeout
.function
= NULL
;
156 EXPORT_SYMBOL(scsi_delete_timer
);
159 * scsi_times_out - Timeout function for normal scsi commands.
160 * @scmd: Cmd that is timing out.
163 * We do not need to lock this. There is the potential for a race
164 * only in that the normal completion handling might run, but if the
165 * normal completion function determines that the timer has already
166 * fired, then it mustn't do anything.
168 void scsi_times_out(struct scsi_cmnd
*scmd
)
170 scsi_log_completion(scmd
, TIMEOUT_ERROR
);
172 if (scmd
->device
->host
->hostt
->eh_timed_out
)
173 switch (scmd
->device
->host
->hostt
->eh_timed_out(scmd
)) {
178 /* This allows a single retry even of a command
179 * with allowed == 0 */
180 if (scmd
->retries
++ > scmd
->allowed
)
182 scsi_add_timer(scmd
, scmd
->timeout_per_command
,
189 if (unlikely(!scsi_eh_scmd_add(scmd
, SCSI_EH_CANCEL_CMD
))) {
190 panic("Error handler thread not present at %p %p %s %d",
191 scmd
, scmd
->device
->host
, __FILE__
, __LINE__
);
196 * scsi_block_when_processing_errors - Prevent cmds from being queued.
197 * @sdev: Device on which we are performing recovery.
200 * We block until the host is out of error recovery, and then check to
201 * see whether the host or the device is offline.
204 * 0 when dev was taken offline by error recovery. 1 OK to proceed.
206 int scsi_block_when_processing_errors(struct scsi_device
*sdev
)
210 wait_event(sdev
->host
->host_wait
, (!test_bit(SHOST_RECOVERY
, &sdev
->host
->shost_state
)));
212 online
= scsi_device_online(sdev
);
214 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: rtn: %d\n", __FUNCTION__
,
219 EXPORT_SYMBOL(scsi_block_when_processing_errors
);
221 #ifdef CONFIG_SCSI_LOGGING
223 * scsi_eh_prt_fail_stats - Log info on failures.
224 * @shost: scsi host being recovered.
225 * @work_q: Queue of scsi cmds to process.
227 static inline void scsi_eh_prt_fail_stats(struct Scsi_Host
*shost
,
228 struct list_head
*work_q
)
230 struct scsi_cmnd
*scmd
;
231 struct scsi_device
*sdev
;
232 int total_failures
= 0;
235 int devices_failed
= 0;
237 shost_for_each_device(sdev
, shost
) {
238 list_for_each_entry(scmd
, work_q
, eh_entry
) {
239 if (scmd
->device
== sdev
) {
241 if (scsi_eh_eflags_chk(scmd
,
249 if (cmd_cancel
|| cmd_failed
) {
250 SCSI_LOG_ERROR_RECOVERY(3,
251 printk("%s: %d:%d:%d:%d cmds failed: %d,"
253 __FUNCTION__
, shost
->host_no
,
254 sdev
->channel
, sdev
->id
, sdev
->lun
,
255 cmd_failed
, cmd_cancel
));
262 SCSI_LOG_ERROR_RECOVERY(2, printk("Total of %d commands on %d"
263 " devices require eh work\n",
264 total_failures
, devices_failed
));
269 * scsi_check_sense - Examine scsi cmd sense
270 * @scmd: Cmd to have sense checked.
273 * SUCCESS or FAILED or NEEDS_RETRY
276 * When a deferred error is detected the current command has
277 * not been executed and needs retrying.
279 static int scsi_check_sense(struct scsi_cmnd
*scmd
)
281 struct scsi_sense_hdr sshdr
;
283 if (! scsi_command_normalize_sense(scmd
, &sshdr
))
284 return FAILED
; /* no valid sense data */
286 if (scsi_sense_is_deferred(&sshdr
))
290 * Previous logic looked for FILEMARK, EOM or ILI which are
291 * mainly associated with tapes and returned SUCCESS.
293 if (sshdr
.response_code
== 0x70) {
295 if (scmd
->sense_buffer
[2] & 0xe0)
299 * descriptor format: look for "stream commands sense data
300 * descriptor" (see SSC-3). Assume single sense data
301 * descriptor. Ignore ILI from SBC-2 READ LONG and WRITE LONG.
303 if ((sshdr
.additional_length
> 3) &&
304 (scmd
->sense_buffer
[8] == 0x4) &&
305 (scmd
->sense_buffer
[11] & 0xe0))
309 switch (sshdr
.sense_key
) {
312 case RECOVERED_ERROR
:
313 return /* soft_error */ SUCCESS
;
315 case ABORTED_COMMAND
:
320 * if we are expecting a cc/ua because of a bus reset that we
321 * performed, treat this just as a retry. otherwise this is
322 * information that we should pass up to the upper-level driver
323 * so that we can deal with it there.
325 if (scmd
->device
->expecting_cc_ua
) {
326 scmd
->device
->expecting_cc_ua
= 0;
330 * if the device is in the process of becoming ready, we
333 if ((sshdr
.asc
== 0x04) && (sshdr
.ascq
== 0x01))
336 * if the device is not started, we need to wake
337 * the error handler to start the motor
339 if (scmd
->device
->allow_restart
&&
340 (sshdr
.asc
== 0x04) && (sshdr
.ascq
== 0x02))
344 /* these three are not supported */
346 case VOLUME_OVERFLOW
:
354 if (scmd
->device
->retry_hwerror
)
359 case ILLEGAL_REQUEST
:
368 * scsi_eh_completed_normally - Disposition a eh cmd on return from LLD.
369 * @scmd: SCSI cmd to examine.
372 * This is *only* called when we are examining the status of commands
373 * queued during error recovery. the main difference here is that we
374 * don't allow for the possibility of retries here, and we are a lot
375 * more restrictive about what we consider acceptable.
377 static int scsi_eh_completed_normally(struct scsi_cmnd
*scmd
)
380 * first check the host byte, to see if there is anything in there
381 * that would indicate what we need to do.
383 if (host_byte(scmd
->result
) == DID_RESET
) {
385 * rats. we are already in the error handler, so we now
386 * get to try and figure out what to do next. if the sense
387 * is valid, we have a pretty good idea of what to do.
388 * if not, we mark it as FAILED.
390 return scsi_check_sense(scmd
);
392 if (host_byte(scmd
->result
) != DID_OK
)
396 * next, check the message byte.
398 if (msg_byte(scmd
->result
) != COMMAND_COMPLETE
)
402 * now, check the status byte to see if this indicates
405 switch (status_byte(scmd
->result
)) {
407 case COMMAND_TERMINATED
:
409 case CHECK_CONDITION
:
410 return scsi_check_sense(scmd
);
412 case INTERMEDIATE_GOOD
:
413 case INTERMEDIATE_C_GOOD
:
415 * who knows? FIXME(eric)
420 case RESERVATION_CONFLICT
:
428 * scsi_eh_times_out - timeout function for error handling.
429 * @scmd: Cmd that is timing out.
432 * During error handling, the kernel thread will be sleeping waiting
433 * for some action to complete on the device. our only job is to
434 * record that it timed out, and to wake up the thread.
436 static void scsi_eh_times_out(struct scsi_cmnd
*scmd
)
438 scsi_eh_eflags_set(scmd
, SCSI_EH_REC_TIMEOUT
);
439 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd:%p\n", __FUNCTION__
,
442 if (scmd
->device
->host
->eh_action
)
443 up(scmd
->device
->host
->eh_action
);
447 * scsi_eh_done - Completion function for error handling.
448 * @scmd: Cmd that is done.
450 static void scsi_eh_done(struct scsi_cmnd
*scmd
)
453 * if the timeout handler is already running, then just set the
454 * flag which says we finished late, and return. we have no
455 * way of stopping the timeout handler from running, so we must
456 * always defer to it.
458 if (del_timer(&scmd
->eh_timeout
)) {
459 scmd
->request
->rq_status
= RQ_SCSI_DONE
;
460 scmd
->owner
= SCSI_OWNER_ERROR_HANDLER
;
462 SCSI_LOG_ERROR_RECOVERY(3, printk("%s scmd: %p result: %x\n",
463 __FUNCTION__
, scmd
, scmd
->result
));
465 if (scmd
->device
->host
->eh_action
)
466 up(scmd
->device
->host
->eh_action
);
471 * scsi_send_eh_cmnd - send a cmd to a device as part of error recovery.
472 * @scmd: SCSI Cmd to send.
473 * @timeout: Timeout for cmd.
476 * The initialization of the structures is quite a bit different in
477 * this case, and furthermore, there is a different completion handler
478 * vs scsi_dispatch_cmd.
480 * SUCCESS or FAILED or NEEDS_RETRY
482 static int scsi_send_eh_cmnd(struct scsi_cmnd
*scmd
, int timeout
)
484 struct Scsi_Host
*host
= scmd
->device
->host
;
485 DECLARE_MUTEX_LOCKED(sem
);
490 * we will use a queued command if possible, otherwise we will
491 * emulate the queuing and calling of completion function ourselves.
493 scmd
->owner
= SCSI_OWNER_LOWLEVEL
;
495 if (scmd
->device
->scsi_level
<= SCSI_2
)
496 scmd
->cmnd
[1] = (scmd
->cmnd
[1] & 0x1f) |
497 (scmd
->device
->lun
<< 5 & 0xe0);
499 scsi_add_timer(scmd
, timeout
, scsi_eh_times_out
);
502 * set up the semaphore so we wait for the command to complete.
504 scmd
->device
->host
->eh_action
= &sem
;
505 scmd
->request
->rq_status
= RQ_SCSI_BUSY
;
507 spin_lock_irqsave(scmd
->device
->host
->host_lock
, flags
);
509 host
->hostt
->queuecommand(scmd
, scsi_eh_done
);
510 spin_unlock_irqrestore(scmd
->device
->host
->host_lock
, flags
);
513 scsi_log_completion(scmd
, SUCCESS
);
515 scmd
->device
->host
->eh_action
= NULL
;
518 * see if timeout. if so, tell the host to forget about it.
519 * in other words, we don't want a callback any more.
521 if (scsi_eh_eflags_chk(scmd
, SCSI_EH_REC_TIMEOUT
)) {
522 scsi_eh_eflags_clr(scmd
, SCSI_EH_REC_TIMEOUT
);
523 scmd
->owner
= SCSI_OWNER_LOWLEVEL
;
526 * as far as the low level driver is
527 * concerned, this command is still active, so
528 * we must give the low level driver a chance
531 * FIXME(eric) - we are not tracking whether we could
532 * abort a timed out command or not. not sure how
533 * we should treat them differently anyways.
535 spin_lock_irqsave(scmd
->device
->host
->host_lock
, flags
);
536 if (scmd
->device
->host
->hostt
->eh_abort_handler
)
537 scmd
->device
->host
->hostt
->eh_abort_handler(scmd
);
538 spin_unlock_irqrestore(scmd
->device
->host
->host_lock
, flags
);
540 scmd
->request
->rq_status
= RQ_SCSI_DONE
;
541 scmd
->owner
= SCSI_OWNER_ERROR_HANDLER
;
546 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd: %p, rtn:%x\n",
547 __FUNCTION__
, scmd
, rtn
));
550 * now examine the actual status codes to see whether the command
551 * actually did complete normally.
553 if (rtn
== SUCCESS
) {
554 rtn
= scsi_eh_completed_normally(scmd
);
555 SCSI_LOG_ERROR_RECOVERY(3,
556 printk("%s: scsi_eh_completed_normally %x\n",
573 * scsi_request_sense - Request sense data from a particular target.
574 * @scmd: SCSI cmd for request sense.
577 * Some hosts automatically obtain this information, others require
578 * that we obtain it on our own. This function will *not* return until
579 * the command either times out, or it completes.
581 static int scsi_request_sense(struct scsi_cmnd
*scmd
)
583 static unsigned char generic_sense
[6] =
584 {REQUEST_SENSE
, 0, 0, 0, 252, 0};
585 unsigned char *scsi_result
;
589 memcpy(scmd
->cmnd
, generic_sense
, sizeof(generic_sense
));
591 scsi_result
= kmalloc(252, GFP_ATOMIC
| (scmd
->device
->host
->hostt
->unchecked_isa_dma
) ? __GFP_DMA
: 0);
594 if (unlikely(!scsi_result
)) {
595 printk(KERN_ERR
"%s: cannot allocate scsi_result.\n",
601 * zero the sense buffer. some host adapters automatically always
602 * request sense, so it is not a good idea that
603 * scmd->request_buffer and scmd->sense_buffer point to the same
604 * address (db). 0 is not a valid sense code.
606 memset(scmd
->sense_buffer
, 0, sizeof(scmd
->sense_buffer
));
607 memset(scsi_result
, 0, 252);
609 saved_result
= scmd
->result
;
610 scmd
->request_buffer
= scsi_result
;
611 scmd
->request_bufflen
= 252;
613 scmd
->cmd_len
= COMMAND_SIZE(scmd
->cmnd
[0]);
614 scmd
->sc_data_direction
= DMA_FROM_DEVICE
;
617 rtn
= scsi_send_eh_cmnd(scmd
, SENSE_TIMEOUT
);
619 /* last chance to have valid sense data */
620 if(!SCSI_SENSE_VALID(scmd
)) {
621 memcpy(scmd
->sense_buffer
, scmd
->request_buffer
,
622 sizeof(scmd
->sense_buffer
));
628 * when we eventually call scsi_finish, we really wish to complete
629 * the original request, so let's restore the original data. (db)
631 scsi_setup_cmd_retry(scmd
);
632 scmd
->result
= saved_result
;
637 * scsi_eh_finish_cmd - Handle a cmd that eh is finished with.
638 * @scmd: Original SCSI cmd that eh has finished.
639 * @done_q: Queue for processed commands.
642 * We don't want to use the normal command completion while we are are
643 * still handling errors - it may cause other commands to be queued,
644 * and that would disturb what we are doing. thus we really want to
645 * keep a list of pending commands for final completion, and once we
646 * are ready to leave error handling we handle completion for real.
648 static void scsi_eh_finish_cmd(struct scsi_cmnd
*scmd
,
649 struct list_head
*done_q
)
651 scmd
->device
->host
->host_failed
--;
652 scmd
->state
= SCSI_STATE_BHQUEUE
;
654 scsi_eh_eflags_clr_all(scmd
);
657 * set this back so that the upper level can correctly free up
660 scsi_setup_cmd_retry(scmd
);
661 list_move_tail(&scmd
->eh_entry
, done_q
);
665 * scsi_eh_get_sense - Get device sense data.
666 * @work_q: Queue of commands to process.
667 * @done_q: Queue of proccessed commands..
670 * See if we need to request sense information. if so, then get it
671 * now, so we have a better idea of what to do.
674 * This has the unfortunate side effect that if a shost adapter does
675 * not automatically request sense information, that we end up shutting
676 * it down before we request it.
678 * All drivers should request sense information internally these days,
679 * so for now all I have to say is tough noogies if you end up in here.
681 * XXX: Long term this code should go away, but that needs an audit of
684 static int scsi_eh_get_sense(struct list_head
*work_q
,
685 struct list_head
*done_q
)
687 struct list_head
*lh
, *lh_sf
;
688 struct scsi_cmnd
*scmd
;
691 list_for_each_safe(lh
, lh_sf
, work_q
) {
692 scmd
= list_entry(lh
, struct scsi_cmnd
, eh_entry
);
693 if (scsi_eh_eflags_chk(scmd
, SCSI_EH_CANCEL_CMD
) ||
694 SCSI_SENSE_VALID(scmd
))
697 SCSI_LOG_ERROR_RECOVERY(2, printk("%s: requesting sense"
701 rtn
= scsi_request_sense(scmd
);
705 SCSI_LOG_ERROR_RECOVERY(3, printk("sense requested for %p"
706 " result %x\n", scmd
,
708 SCSI_LOG_ERROR_RECOVERY(3, scsi_print_sense("bh", scmd
));
710 rtn
= scsi_decide_disposition(scmd
);
713 * if the result was normal, then just pass it along to the
717 /* we don't want this command reissued, just
718 * finished with the sense data, so set
719 * retries to the max allowed to ensure it
720 * won't get reissued */
721 scmd
->retries
= scmd
->allowed
;
722 else if (rtn
!= NEEDS_RETRY
)
725 scsi_eh_finish_cmd(scmd
, done_q
);
728 return list_empty(work_q
);
732 * scsi_try_to_abort_cmd - Ask host to abort a running command.
733 * @scmd: SCSI cmd to abort from Lower Level.
736 * This function will not return until the user's completion function
737 * has been called. there is no timeout on this operation. if the
738 * author of the low-level driver wishes this operation to be timed,
739 * they can provide this facility themselves. helper functions in
740 * scsi_error.c can be supplied to make this easier to do.
742 static int scsi_try_to_abort_cmd(struct scsi_cmnd
*scmd
)
747 if (!scmd
->device
->host
->hostt
->eh_abort_handler
)
751 * scsi_done was called just after the command timed out and before
752 * we had a chance to process it. (db)
754 if (scmd
->serial_number
== 0)
757 scmd
->owner
= SCSI_OWNER_LOWLEVEL
;
759 spin_lock_irqsave(scmd
->device
->host
->host_lock
, flags
);
760 rtn
= scmd
->device
->host
->hostt
->eh_abort_handler(scmd
);
761 spin_unlock_irqrestore(scmd
->device
->host
->host_lock
, flags
);
767 * scsi_eh_tur - Send TUR to device.
768 * @scmd: Scsi cmd to send TUR
771 * 0 - Device is ready. 1 - Device NOT ready.
773 static int scsi_eh_tur(struct scsi_cmnd
*scmd
)
775 static unsigned char tur_command
[6] = {TEST_UNIT_READY
, 0, 0, 0, 0, 0};
776 int retry_cnt
= 1, rtn
;
779 memcpy(scmd
->cmnd
, tur_command
, sizeof(tur_command
));
782 * zero the sense buffer. the scsi spec mandates that any
783 * untransferred sense data should be interpreted as being zero.
785 memset(scmd
->sense_buffer
, 0, sizeof(scmd
->sense_buffer
));
787 scmd
->request_buffer
= NULL
;
788 scmd
->request_bufflen
= 0;
790 scmd
->cmd_len
= COMMAND_SIZE(scmd
->cmnd
[0]);
792 scmd
->sc_data_direction
= DMA_NONE
;
794 rtn
= scsi_send_eh_cmnd(scmd
, SENSE_TIMEOUT
);
797 * when we eventually call scsi_finish, we really wish to complete
798 * the original request, so let's restore the original data. (db)
800 scsi_setup_cmd_retry(scmd
);
803 * hey, we are done. let's look to see what happened.
805 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n",
806 __FUNCTION__
, scmd
, rtn
));
809 else if (rtn
== NEEDS_RETRY
)
816 * scsi_eh_abort_cmds - abort canceled commands.
817 * @shost: scsi host being recovered.
818 * @eh_done_q: list_head for processed commands.
821 * Try and see whether or not it makes sense to try and abort the
822 * running command. this only works out to be the case if we have one
823 * command that has timed out. if the command simply failed, it makes
824 * no sense to try and abort the command, since as far as the shost
825 * adapter is concerned, it isn't running.
827 static int scsi_eh_abort_cmds(struct list_head
*work_q
,
828 struct list_head
*done_q
)
830 struct list_head
*lh
, *lh_sf
;
831 struct scsi_cmnd
*scmd
;
834 list_for_each_safe(lh
, lh_sf
, work_q
) {
835 scmd
= list_entry(lh
, struct scsi_cmnd
, eh_entry
);
836 if (!scsi_eh_eflags_chk(scmd
, SCSI_EH_CANCEL_CMD
))
838 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting cmd:"
839 "0x%p\n", current
->comm
,
841 rtn
= scsi_try_to_abort_cmd(scmd
);
842 if (rtn
== SUCCESS
) {
843 scsi_eh_eflags_clr(scmd
, SCSI_EH_CANCEL_CMD
);
844 if (!scsi_device_online(scmd
->device
) ||
845 !scsi_eh_tur(scmd
)) {
846 scsi_eh_finish_cmd(scmd
, done_q
);
850 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting"
857 return list_empty(work_q
);
861 * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev
862 * @scmd: SCSI cmd used to send BDR
865 * There is no timeout for this operation. if this operation is
866 * unreliable for a given host, then the host itself needs to put a
867 * timer on it, and set the host back to a consistent state prior to
870 static int scsi_try_bus_device_reset(struct scsi_cmnd
*scmd
)
875 if (!scmd
->device
->host
->hostt
->eh_device_reset_handler
)
878 scmd
->owner
= SCSI_OWNER_LOWLEVEL
;
880 spin_lock_irqsave(scmd
->device
->host
->host_lock
, flags
);
881 rtn
= scmd
->device
->host
->hostt
->eh_device_reset_handler(scmd
);
882 spin_unlock_irqrestore(scmd
->device
->host
->host_lock
, flags
);
884 if (rtn
== SUCCESS
) {
885 scmd
->device
->was_reset
= 1;
886 scmd
->device
->expecting_cc_ua
= 1;
893 * scsi_eh_try_stu - Send START_UNIT to device.
894 * @scmd: Scsi cmd to send START_UNIT
897 * 0 - Device is ready. 1 - Device NOT ready.
899 static int scsi_eh_try_stu(struct scsi_cmnd
*scmd
)
901 static unsigned char stu_command
[6] = {START_STOP
, 0, 0, 0, 1, 0};
904 if (!scmd
->device
->allow_restart
)
907 memcpy(scmd
->cmnd
, stu_command
, sizeof(stu_command
));
910 * zero the sense buffer. the scsi spec mandates that any
911 * untransferred sense data should be interpreted as being zero.
913 memset(scmd
->sense_buffer
, 0, sizeof(scmd
->sense_buffer
));
915 scmd
->request_buffer
= NULL
;
916 scmd
->request_bufflen
= 0;
918 scmd
->cmd_len
= COMMAND_SIZE(scmd
->cmnd
[0]);
920 scmd
->sc_data_direction
= DMA_NONE
;
922 rtn
= scsi_send_eh_cmnd(scmd
, START_UNIT_TIMEOUT
);
925 * when we eventually call scsi_finish, we really wish to complete
926 * the original request, so let's restore the original data. (db)
928 scsi_setup_cmd_retry(scmd
);
931 * hey, we are done. let's look to see what happened.
933 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n",
934 __FUNCTION__
, scmd
, rtn
));
941 * scsi_eh_stu - send START_UNIT if needed
942 * @shost: scsi host being recovered.
943 * @eh_done_q: list_head for processed commands.
946 * If commands are failing due to not ready, initializing command required,
947 * try revalidating the device, which will end up sending a start unit.
949 static int scsi_eh_stu(struct Scsi_Host
*shost
,
950 struct list_head
*work_q
,
951 struct list_head
*done_q
)
953 struct list_head
*lh
, *lh_sf
;
954 struct scsi_cmnd
*scmd
, *stu_scmd
;
955 struct scsi_device
*sdev
;
957 shost_for_each_device(sdev
, shost
) {
959 list_for_each_entry(scmd
, work_q
, eh_entry
)
960 if (scmd
->device
== sdev
&& SCSI_SENSE_VALID(scmd
) &&
961 scsi_check_sense(scmd
) == FAILED
) {
969 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending START_UNIT to sdev:"
970 " 0x%p\n", current
->comm
, sdev
));
972 if (!scsi_eh_try_stu(stu_scmd
)) {
973 if (!scsi_device_online(sdev
) ||
974 !scsi_eh_tur(stu_scmd
)) {
975 list_for_each_safe(lh
, lh_sf
, work_q
) {
976 scmd
= list_entry(lh
, struct scsi_cmnd
, eh_entry
);
977 if (scmd
->device
== sdev
)
978 scsi_eh_finish_cmd(scmd
, done_q
);
982 SCSI_LOG_ERROR_RECOVERY(3,
983 printk("%s: START_UNIT failed to sdev:"
984 " 0x%p\n", current
->comm
, sdev
));
988 return list_empty(work_q
);
993 * scsi_eh_bus_device_reset - send bdr if needed
994 * @shost: scsi host being recovered.
995 * @eh_done_q: list_head for processed commands.
998 * Try a bus device reset. still, look to see whether we have multiple
999 * devices that are jammed or not - if we have multiple devices, it
1000 * makes no sense to try bus_device_reset - we really would need to try
1001 * a bus_reset instead.
1003 static int scsi_eh_bus_device_reset(struct Scsi_Host
*shost
,
1004 struct list_head
*work_q
,
1005 struct list_head
*done_q
)
1007 struct list_head
*lh
, *lh_sf
;
1008 struct scsi_cmnd
*scmd
, *bdr_scmd
;
1009 struct scsi_device
*sdev
;
1012 shost_for_each_device(sdev
, shost
) {
1014 list_for_each_entry(scmd
, work_q
, eh_entry
)
1015 if (scmd
->device
== sdev
) {
1023 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BDR sdev:"
1024 " 0x%p\n", current
->comm
,
1026 rtn
= scsi_try_bus_device_reset(bdr_scmd
);
1027 if (rtn
== SUCCESS
) {
1028 if (!scsi_device_online(sdev
) ||
1029 !scsi_eh_tur(bdr_scmd
)) {
1030 list_for_each_safe(lh
, lh_sf
,
1032 scmd
= list_entry(lh
, struct
1035 if (scmd
->device
== sdev
)
1036 scsi_eh_finish_cmd(scmd
,
1041 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BDR"
1049 return list_empty(work_q
);
1053 * scsi_try_bus_reset - ask host to perform a bus reset
1054 * @scmd: SCSI cmd to send bus reset.
1056 static int scsi_try_bus_reset(struct scsi_cmnd
*scmd
)
1058 unsigned long flags
;
1061 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Bus RST\n",
1063 scmd
->owner
= SCSI_OWNER_LOWLEVEL
;
1064 scmd
->serial_number_at_timeout
= scmd
->serial_number
;
1066 if (!scmd
->device
->host
->hostt
->eh_bus_reset_handler
)
1069 spin_lock_irqsave(scmd
->device
->host
->host_lock
, flags
);
1070 rtn
= scmd
->device
->host
->hostt
->eh_bus_reset_handler(scmd
);
1071 spin_unlock_irqrestore(scmd
->device
->host
->host_lock
, flags
);
1073 if (rtn
== SUCCESS
) {
1074 if (!scmd
->device
->host
->hostt
->skip_settle_delay
)
1075 ssleep(BUS_RESET_SETTLE_TIME
);
1076 spin_lock_irqsave(scmd
->device
->host
->host_lock
, flags
);
1077 scsi_report_bus_reset(scmd
->device
->host
, scmd
->device
->channel
);
1078 spin_unlock_irqrestore(scmd
->device
->host
->host_lock
, flags
);
1085 * scsi_try_host_reset - ask host adapter to reset itself
1086 * @scmd: SCSI cmd to send hsot reset.
1088 static int scsi_try_host_reset(struct scsi_cmnd
*scmd
)
1090 unsigned long flags
;
1093 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Host RST\n",
1095 scmd
->owner
= SCSI_OWNER_LOWLEVEL
;
1096 scmd
->serial_number_at_timeout
= scmd
->serial_number
;
1098 if (!scmd
->device
->host
->hostt
->eh_host_reset_handler
)
1101 spin_lock_irqsave(scmd
->device
->host
->host_lock
, flags
);
1102 rtn
= scmd
->device
->host
->hostt
->eh_host_reset_handler(scmd
);
1103 spin_unlock_irqrestore(scmd
->device
->host
->host_lock
, flags
);
1105 if (rtn
== SUCCESS
) {
1106 if (!scmd
->device
->host
->hostt
->skip_settle_delay
)
1107 ssleep(HOST_RESET_SETTLE_TIME
);
1108 spin_lock_irqsave(scmd
->device
->host
->host_lock
, flags
);
1109 scsi_report_bus_reset(scmd
->device
->host
, scmd
->device
->channel
);
1110 spin_unlock_irqrestore(scmd
->device
->host
->host_lock
, flags
);
1117 * scsi_eh_bus_reset - send a bus reset
1118 * @shost: scsi host being recovered.
1119 * @eh_done_q: list_head for processed commands.
1121 static int scsi_eh_bus_reset(struct Scsi_Host
*shost
,
1122 struct list_head
*work_q
,
1123 struct list_head
*done_q
)
1125 struct list_head
*lh
, *lh_sf
;
1126 struct scsi_cmnd
*scmd
;
1127 struct scsi_cmnd
*chan_scmd
;
1128 unsigned int channel
;
1132 * we really want to loop over the various channels, and do this on
1133 * a channel by channel basis. we should also check to see if any
1134 * of the failed commands are on soft_reset devices, and if so, skip
1138 for (channel
= 0; channel
<= shost
->max_channel
; channel
++) {
1140 list_for_each_entry(scmd
, work_q
, eh_entry
) {
1141 if (channel
== scmd
->device
->channel
) {
1145 * FIXME add back in some support for
1146 * soft_reset devices.
1153 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BRST chan:"
1154 " %d\n", current
->comm
,
1156 rtn
= scsi_try_bus_reset(chan_scmd
);
1157 if (rtn
== SUCCESS
) {
1158 list_for_each_safe(lh
, lh_sf
, work_q
) {
1159 scmd
= list_entry(lh
, struct scsi_cmnd
,
1161 if (channel
== scmd
->device
->channel
)
1162 if (!scsi_device_online(scmd
->device
) ||
1164 scsi_eh_finish_cmd(scmd
,
1168 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BRST"
1169 " failed chan: %d\n",
1174 return list_empty(work_q
);
1178 * scsi_eh_host_reset - send a host reset
1179 * @work_q: list_head for processed commands.
1180 * @done_q: list_head for processed commands.
1182 static int scsi_eh_host_reset(struct list_head
*work_q
,
1183 struct list_head
*done_q
)
1186 struct list_head
*lh
, *lh_sf
;
1187 struct scsi_cmnd
*scmd
;
1189 if (!list_empty(work_q
)) {
1190 scmd
= list_entry(work_q
->next
,
1191 struct scsi_cmnd
, eh_entry
);
1193 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending HRST\n"
1196 rtn
= scsi_try_host_reset(scmd
);
1197 if (rtn
== SUCCESS
) {
1198 list_for_each_safe(lh
, lh_sf
, work_q
) {
1199 scmd
= list_entry(lh
, struct scsi_cmnd
, eh_entry
);
1200 if (!scsi_device_online(scmd
->device
) ||
1201 (!scsi_eh_try_stu(scmd
) && !scsi_eh_tur(scmd
)) ||
1203 scsi_eh_finish_cmd(scmd
, done_q
);
1206 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: HRST"
1211 return list_empty(work_q
);
1215 * scsi_eh_offline_sdevs - offline scsi devices that fail to recover
1216 * @work_q: list_head for processed commands.
1217 * @done_q: list_head for processed commands.
1220 static void scsi_eh_offline_sdevs(struct list_head
*work_q
,
1221 struct list_head
*done_q
)
1223 struct list_head
*lh
, *lh_sf
;
1224 struct scsi_cmnd
*scmd
;
1226 list_for_each_safe(lh
, lh_sf
, work_q
) {
1227 scmd
= list_entry(lh
, struct scsi_cmnd
, eh_entry
);
1228 printk(KERN_INFO
"scsi: Device offlined - not"
1229 " ready after error recovery: host"
1230 " %d channel %d id %d lun %d\n",
1231 scmd
->device
->host
->host_no
,
1232 scmd
->device
->channel
,
1235 scsi_device_set_state(scmd
->device
, SDEV_OFFLINE
);
1236 if (scsi_eh_eflags_chk(scmd
, SCSI_EH_CANCEL_CMD
)) {
1238 * FIXME: Handle lost cmds.
1241 scsi_eh_finish_cmd(scmd
, done_q
);
1247 * scsi_decide_disposition - Disposition a cmd on return from LLD.
1248 * @scmd: SCSI cmd to examine.
1251 * This is *only* called when we are examining the status after sending
1252 * out the actual data command. any commands that are queued for error
1253 * recovery (e.g. test_unit_ready) do *not* come through here.
1255 * When this routine returns failed, it means the error handler thread
1256 * is woken. In cases where the error code indicates an error that
1257 * doesn't require the error handler read (i.e. we don't need to
1258 * abort/reset), this function should return SUCCESS.
1260 int scsi_decide_disposition(struct scsi_cmnd
*scmd
)
1265 * if the device is offline, then we clearly just pass the result back
1266 * up to the top level.
1268 if (!scsi_device_online(scmd
->device
)) {
1269 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: device offline - report"
1276 * first check the host byte, to see if there is anything in there
1277 * that would indicate what we need to do.
1279 switch (host_byte(scmd
->result
)) {
1280 case DID_PASSTHROUGH
:
1282 * no matter what, pass this through to the upper layer.
1283 * nuke this special code so that it looks like we are saying
1286 scmd
->result
&= 0xff00ffff;
1290 * looks good. drop through, and check the next byte.
1293 case DID_NO_CONNECT
:
1294 case DID_BAD_TARGET
:
1297 * note - this means that we just report the status back
1298 * to the top level driver, not that we actually think
1299 * that it indicates SUCCESS.
1303 * when the low level driver returns did_soft_error,
1304 * it is responsible for keeping an internal retry counter
1305 * in order to avoid endless loops (db)
1307 * actually this is a bug in this function here. we should
1308 * be mindful of the maximum number of retries specified
1309 * and not get stuck in a loop.
1311 case DID_SOFT_ERROR
:
1317 if (msg_byte(scmd
->result
) == COMMAND_COMPLETE
&&
1318 status_byte(scmd
->result
) == RESERVATION_CONFLICT
)
1320 * execute reservation conflict processing code
1331 * when we scan the bus, we get timeout messages for
1332 * these commands if there is no device available.
1333 * other hosts report did_no_connect for the same thing.
1335 if ((scmd
->cmnd
[0] == TEST_UNIT_READY
||
1336 scmd
->cmnd
[0] == INQUIRY
)) {
1348 * next, check the message byte.
1350 if (msg_byte(scmd
->result
) != COMMAND_COMPLETE
)
1354 * check the status byte to see if this indicates anything special.
1356 switch (status_byte(scmd
->result
)) {
1359 * the case of trying to send too many commands to a
1360 * tagged queueing device.
1364 * device can't talk to us at the moment. Should only
1365 * occur (SAM-3) when the task queue is empty, so will cause
1366 * the empty queue handling to trigger a stall in the
1369 return ADD_TO_MLQUEUE
;
1371 case COMMAND_TERMINATED
:
1374 case CHECK_CONDITION
:
1375 rtn
= scsi_check_sense(scmd
);
1376 if (rtn
== NEEDS_RETRY
)
1378 /* if rtn == FAILED, we have no sense information;
1379 * returning FAILED will wake the error handler thread
1380 * to collect the sense and redo the decide
1383 case CONDITION_GOOD
:
1384 case INTERMEDIATE_GOOD
:
1385 case INTERMEDIATE_C_GOOD
:
1388 * who knows? FIXME(eric)
1392 case RESERVATION_CONFLICT
:
1393 printk(KERN_INFO
"scsi: reservation conflict: host"
1394 " %d channel %d id %d lun %d\n",
1395 scmd
->device
->host
->host_no
, scmd
->device
->channel
,
1396 scmd
->device
->id
, scmd
->device
->lun
);
1397 return SUCCESS
; /* causes immediate i/o error */
1405 /* we requeue for retry because the error was retryable, and
1406 * the request was not marked fast fail. Note that above,
1407 * even if the request is marked fast fail, we still requeue
1408 * for queue congestion conditions (QUEUE_FULL or BUSY) */
1409 if ((++scmd
->retries
) < scmd
->allowed
1410 && !blk_noretry_request(scmd
->request
)) {
1414 * no more retries - report this one back to upper level.
1421 * scsi_eh_lock_done - done function for eh door lock request
1422 * @scmd: SCSI command block for the door lock request
1425 * We completed the asynchronous door lock request, and it has either
1426 * locked the door or failed. We must free the command structures
1427 * associated with this request.
1429 static void scsi_eh_lock_done(struct scsi_cmnd
*scmd
)
1431 struct scsi_request
*sreq
= scmd
->sc_request
;
1433 scsi_release_request(sreq
);
1438 * scsi_eh_lock_door - Prevent medium removal for the specified device
1439 * @sdev: SCSI device to prevent medium removal
1442 * We must be called from process context; scsi_allocate_request()
1446 * We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the
1447 * head of the devices request queue, and continue.
1450 * scsi_allocate_request() may sleep waiting for existing requests to
1451 * be processed. However, since we haven't kicked off any request
1452 * processing for this host, this may deadlock.
1454 * If scsi_allocate_request() fails for what ever reason, we
1455 * completely forget to lock the door.
1457 static void scsi_eh_lock_door(struct scsi_device
*sdev
)
1459 struct scsi_request
*sreq
= scsi_allocate_request(sdev
, GFP_KERNEL
);
1461 if (unlikely(!sreq
)) {
1462 printk(KERN_ERR
"%s: request allocate failed,"
1463 "prevent media removal cmd not sent\n", __FUNCTION__
);
1467 sreq
->sr_cmnd
[0] = ALLOW_MEDIUM_REMOVAL
;
1468 sreq
->sr_cmnd
[1] = 0;
1469 sreq
->sr_cmnd
[2] = 0;
1470 sreq
->sr_cmnd
[3] = 0;
1471 sreq
->sr_cmnd
[4] = SCSI_REMOVAL_PREVENT
;
1472 sreq
->sr_cmnd
[5] = 0;
1473 sreq
->sr_data_direction
= DMA_NONE
;
1474 sreq
->sr_bufflen
= 0;
1475 sreq
->sr_buffer
= NULL
;
1476 sreq
->sr_allowed
= 5;
1477 sreq
->sr_done
= scsi_eh_lock_done
;
1478 sreq
->sr_timeout_per_command
= 10 * HZ
;
1479 sreq
->sr_cmd_len
= COMMAND_SIZE(sreq
->sr_cmnd
[0]);
1481 scsi_insert_special_req(sreq
, 1);
1486 * scsi_restart_operations - restart io operations to the specified host.
1487 * @shost: Host we are restarting.
1490 * When we entered the error handler, we blocked all further i/o to
1491 * this device. we need to 'reverse' this process.
1493 static void scsi_restart_operations(struct Scsi_Host
*shost
)
1495 struct scsi_device
*sdev
;
1498 * If the door was locked, we need to insert a door lock request
1499 * onto the head of the SCSI request queue for the device. There
1500 * is no point trying to lock the door of an off-line device.
1502 shost_for_each_device(sdev
, shost
) {
1503 if (scsi_device_online(sdev
) && sdev
->locked
)
1504 scsi_eh_lock_door(sdev
);
1508 * next free up anything directly waiting upon the host. this
1509 * will be requests for character device operations, and also for
1510 * ioctls to queued block devices.
1512 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: waking up host to restart\n",
1515 clear_bit(SHOST_RECOVERY
, &shost
->shost_state
);
1517 wake_up(&shost
->host_wait
);
1520 * finally we need to re-initiate requests that may be pending. we will
1521 * have had everything blocked while error handling is taking place, and
1522 * now that error recovery is done, we will need to ensure that these
1523 * requests are started.
1525 scsi_run_host_queues(shost
);
1529 * scsi_eh_ready_devs - check device ready state and recover if not.
1530 * @shost: host to be recovered.
1531 * @eh_done_q: list_head for processed commands.
1534 static void scsi_eh_ready_devs(struct Scsi_Host
*shost
,
1535 struct list_head
*work_q
,
1536 struct list_head
*done_q
)
1538 if (!scsi_eh_stu(shost
, work_q
, done_q
))
1539 if (!scsi_eh_bus_device_reset(shost
, work_q
, done_q
))
1540 if (!scsi_eh_bus_reset(shost
, work_q
, done_q
))
1541 if (!scsi_eh_host_reset(work_q
, done_q
))
1542 scsi_eh_offline_sdevs(work_q
, done_q
);
1546 * scsi_eh_flush_done_q - finish processed commands or retry them.
1547 * @done_q: list_head of processed commands.
1550 static void scsi_eh_flush_done_q(struct list_head
*done_q
)
1552 struct list_head
*lh
, *lh_sf
;
1553 struct scsi_cmnd
*scmd
;
1555 list_for_each_safe(lh
, lh_sf
, done_q
) {
1556 scmd
= list_entry(lh
, struct scsi_cmnd
, eh_entry
);
1558 if (scsi_device_online(scmd
->device
) &&
1559 !blk_noretry_request(scmd
->request
) &&
1560 (++scmd
->retries
< scmd
->allowed
)) {
1561 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush"
1565 scsi_queue_insert(scmd
, SCSI_MLQUEUE_EH_RETRY
);
1568 scmd
->result
|= (DRIVER_TIMEOUT
<< 24);
1569 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush finish"
1571 current
->comm
, scmd
));
1572 scsi_finish_command(scmd
);
1578 * scsi_unjam_host - Attempt to fix a host which has a cmd that failed.
1579 * @shost: Host to unjam.
1582 * When we come in here, we *know* that all commands on the bus have
1583 * either completed, failed or timed out. we also know that no further
1584 * commands are being sent to the host, so things are relatively quiet
1585 * and we have freedom to fiddle with things as we wish.
1587 * This is only the *default* implementation. it is possible for
1588 * individual drivers to supply their own version of this function, and
1589 * if the maintainer wishes to do this, it is strongly suggested that
1590 * this function be taken as a template and modified. this function
1591 * was designed to correctly handle problems for about 95% of the
1592 * different cases out there, and it should always provide at least a
1593 * reasonable amount of error recovery.
1595 * Any command marked 'failed' or 'timeout' must eventually have
1596 * scsi_finish_cmd() called for it. we do all of the retry stuff
1597 * here, so when we restart the host after we return it should have an
1600 static void scsi_unjam_host(struct Scsi_Host
*shost
)
1602 unsigned long flags
;
1603 LIST_HEAD(eh_work_q
);
1604 LIST_HEAD(eh_done_q
);
1606 spin_lock_irqsave(shost
->host_lock
, flags
);
1607 list_splice_init(&shost
->eh_cmd_q
, &eh_work_q
);
1608 spin_unlock_irqrestore(shost
->host_lock
, flags
);
1610 SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(shost
, &eh_work_q
));
1612 if (!scsi_eh_get_sense(&eh_work_q
, &eh_done_q
))
1613 if (!scsi_eh_abort_cmds(&eh_work_q
, &eh_done_q
))
1614 scsi_eh_ready_devs(shost
, &eh_work_q
, &eh_done_q
);
1616 scsi_eh_flush_done_q(&eh_done_q
);
1620 * scsi_error_handler - Handle errors/timeouts of SCSI cmds.
1621 * @data: Host for which we are running.
1624 * This is always run in the context of a kernel thread. The idea is
1625 * that we start this thing up when the kernel starts up (one per host
1626 * that we detect), and it immediately goes to sleep and waits for some
1627 * event (i.e. failure). When this takes place, we have the job of
1628 * trying to unjam the bus and restarting things.
1630 int scsi_error_handler(void *data
)
1632 struct Scsi_Host
*shost
= (struct Scsi_Host
*) data
;
1634 DECLARE_MUTEX_LOCKED(sem
);
1640 daemonize("scsi_eh_%d", shost
->host_no
);
1642 current
->flags
|= PF_NOFREEZE
;
1644 shost
->eh_wait
= &sem
;
1645 shost
->ehandler
= current
;
1648 * Wake up the thread that created us.
1650 SCSI_LOG_ERROR_RECOVERY(3, printk("Wake up parent of"
1651 " scsi_eh_%d\n",shost
->host_no
));
1653 complete(shost
->eh_notify
);
1657 * If we get a signal, it means we are supposed to go
1658 * away and die. This typically happens if the user is
1659 * trying to unload a module.
1661 SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler"
1663 " sleeping\n",shost
->host_no
));
1666 * Note - we always use down_interruptible with the semaphore
1667 * even if the module was loaded as part of the kernel. The
1668 * reason is that down() will cause this thread to be counted
1669 * in the load average as a running process, and down
1670 * interruptible doesn't. Given that we need to allow this
1671 * thread to die if the driver was loaded as a module, using
1672 * semaphores isn't unreasonable.
1674 down_interruptible(&sem
);
1678 SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler"
1679 " scsi_eh_%d waking"
1680 " up\n",shost
->host_no
));
1682 shost
->eh_active
= 1;
1685 * We have a host that is failing for some reason. Figure out
1686 * what we need to do to get it up and online again (if we can).
1687 * If we fail, we end up taking the thing offline.
1689 if (shost
->hostt
->eh_strategy_handler
)
1690 rtn
= shost
->hostt
->eh_strategy_handler(shost
);
1692 scsi_unjam_host(shost
);
1694 shost
->eh_active
= 0;
1697 * Note - if the above fails completely, the action is to take
1698 * individual devices offline and flush the queue of any
1699 * outstanding requests that may have been pending. When we
1700 * restart, we restart any I/O to any other devices on the bus
1701 * which are still online.
1703 scsi_restart_operations(shost
);
1707 SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler scsi_eh_%d"
1708 " exiting\n",shost
->host_no
));
1711 * Make sure that nobody tries to wake us up again.
1713 shost
->eh_wait
= NULL
;
1716 * Knock this down too. From this point on, the host is flying
1717 * without a pilot. If this is because the module is being unloaded,
1718 * that's fine. If the user sent a signal to this thing, we are
1719 * potentially in real danger.
1721 shost
->eh_active
= 0;
1722 shost
->ehandler
= NULL
;
1725 * If anyone is waiting for us to exit (i.e. someone trying to unload
1726 * a driver), then wake up that process to let them know we are on
1727 * the way out the door.
1729 complete_and_exit(shost
->eh_notify
, 0);
1734 * Function: scsi_report_bus_reset()
1736 * Purpose: Utility function used by low-level drivers to report that
1737 * they have observed a bus reset on the bus being handled.
1739 * Arguments: shost - Host in question
1740 * channel - channel on which reset was observed.
1744 * Lock status: Host lock must be held.
1746 * Notes: This only needs to be called if the reset is one which
1747 * originates from an unknown location. Resets originated
1748 * by the mid-level itself don't need to call this, but there
1749 * should be no harm.
1751 * The main purpose of this is to make sure that a CHECK_CONDITION
1752 * is properly treated.
1754 void scsi_report_bus_reset(struct Scsi_Host
*shost
, int channel
)
1756 struct scsi_device
*sdev
;
1758 __shost_for_each_device(sdev
, shost
) {
1759 if (channel
== sdev
->channel
) {
1760 sdev
->was_reset
= 1;
1761 sdev
->expecting_cc_ua
= 1;
1765 EXPORT_SYMBOL(scsi_report_bus_reset
);
1768 * Function: scsi_report_device_reset()
1770 * Purpose: Utility function used by low-level drivers to report that
1771 * they have observed a device reset on the device being handled.
1773 * Arguments: shost - Host in question
1774 * channel - channel on which reset was observed
1775 * target - target on which reset was observed
1779 * Lock status: Host lock must be held
1781 * Notes: This only needs to be called if the reset is one which
1782 * originates from an unknown location. Resets originated
1783 * by the mid-level itself don't need to call this, but there
1784 * should be no harm.
1786 * The main purpose of this is to make sure that a CHECK_CONDITION
1787 * is properly treated.
1789 void scsi_report_device_reset(struct Scsi_Host
*shost
, int channel
, int target
)
1791 struct scsi_device
*sdev
;
1793 __shost_for_each_device(sdev
, shost
) {
1794 if (channel
== sdev
->channel
&&
1795 target
== sdev
->id
) {
1796 sdev
->was_reset
= 1;
1797 sdev
->expecting_cc_ua
= 1;
1801 EXPORT_SYMBOL(scsi_report_device_reset
);
1804 scsi_reset_provider_done_command(struct scsi_cmnd
*scmd
)
1809 * Function: scsi_reset_provider
1811 * Purpose: Send requested reset to a bus or device at any phase.
1813 * Arguments: device - device to send reset to
1814 * flag - reset type (see scsi.h)
1816 * Returns: SUCCESS/FAILURE.
1818 * Notes: This is used by the SCSI Generic driver to provide
1819 * Bus/Device reset capability.
1822 scsi_reset_provider(struct scsi_device
*dev
, int flag
)
1824 struct scsi_cmnd
*scmd
= scsi_get_command(dev
, GFP_KERNEL
);
1828 scmd
->request
= &req
;
1829 memset(&scmd
->eh_timeout
, 0, sizeof(scmd
->eh_timeout
));
1830 scmd
->request
->rq_status
= RQ_SCSI_BUSY
;
1831 scmd
->state
= SCSI_STATE_INITIALIZING
;
1832 scmd
->owner
= SCSI_OWNER_MIDLEVEL
;
1834 memset(&scmd
->cmnd
, '\0', sizeof(scmd
->cmnd
));
1836 scmd
->scsi_done
= scsi_reset_provider_done_command
;
1838 scmd
->buffer
= NULL
;
1840 scmd
->request_buffer
= NULL
;
1841 scmd
->request_bufflen
= 0;
1842 scmd
->internal_timeout
= NORMAL_TIMEOUT
;
1843 scmd
->abort_reason
= DID_ABORT
;
1847 scmd
->sc_data_direction
= DMA_BIDIRECTIONAL
;
1848 scmd
->sc_request
= NULL
;
1849 scmd
->sc_magic
= SCSI_CMND_MAGIC
;
1851 init_timer(&scmd
->eh_timeout
);
1854 * Sometimes the command can get back into the timer chain,
1855 * so use the pid as an identifier.
1860 case SCSI_TRY_RESET_DEVICE
:
1861 rtn
= scsi_try_bus_device_reset(scmd
);
1865 case SCSI_TRY_RESET_BUS
:
1866 rtn
= scsi_try_bus_reset(scmd
);
1870 case SCSI_TRY_RESET_HOST
:
1871 rtn
= scsi_try_host_reset(scmd
);
1877 scsi_delete_timer(scmd
);
1878 scsi_next_command(scmd
);
1881 EXPORT_SYMBOL(scsi_reset_provider
);
1884 * scsi_normalize_sense - normalize main elements from either fixed or
1885 * descriptor sense data format into a common format.
1887 * @sense_buffer: byte array containing sense data returned by device
1888 * @sb_len: number of valid bytes in sense_buffer
1889 * @sshdr: pointer to instance of structure that common
1890 * elements are written to.
1893 * The "main elements" from sense data are: response_code, sense_key,
1894 * asc, ascq and additional_length (only for descriptor format).
1896 * Typically this function can be called after a device has
1897 * responded to a SCSI command with the CHECK_CONDITION status.
1900 * 1 if valid sense data information found, else 0;
1902 int scsi_normalize_sense(const u8
*sense_buffer
, int sb_len
,
1903 struct scsi_sense_hdr
*sshdr
)
1905 if (!sense_buffer
|| !sb_len
|| (sense_buffer
[0] & 0x70) != 0x70)
1908 memset(sshdr
, 0, sizeof(struct scsi_sense_hdr
));
1910 sshdr
->response_code
= (sense_buffer
[0] & 0x7f);
1911 if (sshdr
->response_code
>= 0x72) {
1916 sshdr
->sense_key
= (sense_buffer
[1] & 0xf);
1918 sshdr
->asc
= sense_buffer
[2];
1920 sshdr
->ascq
= sense_buffer
[3];
1922 sshdr
->additional_length
= sense_buffer
[7];
1928 sshdr
->sense_key
= (sense_buffer
[2] & 0xf);
1930 sb_len
= (sb_len
< (sense_buffer
[7] + 8)) ?
1931 sb_len
: (sense_buffer
[7] + 8);
1933 sshdr
->asc
= sense_buffer
[12];
1935 sshdr
->ascq
= sense_buffer
[13];
1941 EXPORT_SYMBOL(scsi_normalize_sense
);
1943 int scsi_request_normalize_sense(struct scsi_request
*sreq
,
1944 struct scsi_sense_hdr
*sshdr
)
1946 return scsi_normalize_sense(sreq
->sr_sense_buffer
,
1947 sizeof(sreq
->sr_sense_buffer
), sshdr
);
1949 EXPORT_SYMBOL(scsi_request_normalize_sense
);
1951 int scsi_command_normalize_sense(struct scsi_cmnd
*cmd
,
1952 struct scsi_sense_hdr
*sshdr
)
1954 return scsi_normalize_sense(cmd
->sense_buffer
,
1955 sizeof(cmd
->sense_buffer
), sshdr
);
1957 EXPORT_SYMBOL(scsi_command_normalize_sense
);
1960 * scsi_sense_desc_find - search for a given descriptor type in
1961 * descriptor sense data format.
1963 * @sense_buffer: byte array of descriptor format sense data
1964 * @sb_len: number of valid bytes in sense_buffer
1965 * @desc_type: value of descriptor type to find
1966 * (e.g. 0 -> information)
1969 * only valid when sense data is in descriptor format
1972 * pointer to start of (first) descriptor if found else NULL
1974 const u8
* scsi_sense_desc_find(const u8
* sense_buffer
, int sb_len
,
1977 int add_sen_len
, add_len
, desc_len
, k
;
1980 if ((sb_len
< 8) || (0 == (add_sen_len
= sense_buffer
[7])))
1982 if ((sense_buffer
[0] < 0x72) || (sense_buffer
[0] > 0x73))
1984 add_sen_len
= (add_sen_len
< (sb_len
- 8)) ?
1985 add_sen_len
: (sb_len
- 8);
1986 descp
= &sense_buffer
[8];
1987 for (desc_len
= 0, k
= 0; k
< add_sen_len
; k
+= desc_len
) {
1989 add_len
= (k
< (add_sen_len
- 1)) ? descp
[1]: -1;
1990 desc_len
= add_len
+ 2;
1991 if (descp
[0] == desc_type
)
1993 if (add_len
< 0) // short descriptor ??
1998 EXPORT_SYMBOL(scsi_sense_desc_find
);
2001 * scsi_get_sense_info_fld - attempts to get information field from
2002 * sense data (either fixed or descriptor format)
2004 * @sense_buffer: byte array of sense data
2005 * @sb_len: number of valid bytes in sense_buffer
2006 * @info_out: pointer to 64 integer where 8 or 4 byte information
2007 * field will be placed if found.
2010 * 1 if information field found, 0 if not found.
2012 int scsi_get_sense_info_fld(const u8
* sense_buffer
, int sb_len
,
2021 switch (sense_buffer
[0] & 0x7f) {
2024 if (sense_buffer
[0] & 0x80) {
2025 *info_out
= (sense_buffer
[3] << 24) +
2026 (sense_buffer
[4] << 16) +
2027 (sense_buffer
[5] << 8) + sense_buffer
[6];
2033 ucp
= scsi_sense_desc_find(sense_buffer
, sb_len
,
2035 if (ucp
&& (0xa == ucp
[1])) {
2037 for (j
= 0; j
< 8; ++j
) {
2050 EXPORT_SYMBOL(scsi_get_sense_info_fld
);