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/kthread.h>
24 #include <linux/interrupt.h>
25 #include <linux/blkdev.h>
26 #include <linux/delay.h>
28 #include <scsi/scsi.h>
29 #include <scsi/scsi_dbg.h>
30 #include <scsi/scsi_device.h>
31 #include <scsi/scsi_eh.h>
32 #include <scsi/scsi_host.h>
33 #include <scsi/scsi_ioctl.h>
34 #include <scsi/scsi_request.h>
36 #include "scsi_priv.h"
37 #include "scsi_logging.h"
39 #define SENSE_TIMEOUT (10*HZ)
40 #define START_UNIT_TIMEOUT (30*HZ)
43 * These should *probably* be handled by the host itself.
44 * Since it is allowed to sleep, it probably should.
46 #define BUS_RESET_SETTLE_TIME (10)
47 #define HOST_RESET_SETTLE_TIME (10)
49 /* called with shost->host_lock held */
50 void scsi_eh_wakeup(struct Scsi_Host *shost)
52 if (shost->host_busy == shost->host_failed) {
54 SCSI_LOG_ERROR_RECOVERY(5,
55 printk("Waking error handler thread\n"));
60 * scsi_eh_scmd_add - add scsi cmd to error handling.
61 * @scmd: scmd to run eh on.
62 * @eh_flag: optional SCSI_EH flag.
67 int scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag)
69 struct Scsi_Host *shost = scmd->device->host;
72 if (shost->eh_wait == NULL)
75 spin_lock_irqsave(shost->host_lock, flags);
77 scmd->eh_eflags |= eh_flag;
78 list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q);
79 scsi_host_set_state(shost, SHOST_RECOVERY);
81 scsi_eh_wakeup(shost);
82 spin_unlock_irqrestore(shost->host_lock, flags);
87 * scsi_add_timer - Start timeout timer for a single scsi command.
88 * @scmd: scsi command that is about to start running.
89 * @timeout: amount of time to allow this command to run.
90 * @complete: timeout function to call if timer isn't canceled.
93 * This should be turned into an inline function. Each scsi command
94 * has its own timer, and as it is added to the queue, we set up the
95 * timer. When the command completes, we cancel the timer.
97 void scsi_add_timer(struct scsi_cmnd *scmd, int timeout,
98 void (*complete)(struct scsi_cmnd *))
102 * If the clock was already running for this command, then
103 * first delete the timer. The timer handling code gets rather
104 * confused if we don't do this.
106 if (scmd->eh_timeout.function)
107 del_timer(&scmd->eh_timeout);
109 scmd->eh_timeout.data = (unsigned long)scmd;
110 scmd->eh_timeout.expires = jiffies + timeout;
111 scmd->eh_timeout.function = (void (*)(unsigned long)) complete;
113 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p, time:"
114 " %d, (%p)\n", __FUNCTION__,
115 scmd, timeout, complete));
117 add_timer(&scmd->eh_timeout);
119 EXPORT_SYMBOL(scsi_add_timer);
122 * scsi_delete_timer - Delete/cancel timer for a given function.
123 * @scmd: Cmd that we are canceling timer for
126 * This should be turned into an inline function.
129 * 1 if we were able to detach the timer. 0 if we blew it, and the
130 * timer function has already started to run.
132 int scsi_delete_timer(struct scsi_cmnd *scmd)
136 rtn = del_timer(&scmd->eh_timeout);
138 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p,"
139 " rtn: %d\n", __FUNCTION__,
142 scmd->eh_timeout.data = (unsigned long)NULL;
143 scmd->eh_timeout.function = NULL;
147 EXPORT_SYMBOL(scsi_delete_timer);
150 * scsi_times_out - Timeout function for normal scsi commands.
151 * @scmd: Cmd that is timing out.
154 * We do not need to lock this. There is the potential for a race
155 * only in that the normal completion handling might run, but if the
156 * normal completion function determines that the timer has already
157 * fired, then it mustn't do anything.
159 void scsi_times_out(struct scsi_cmnd *scmd)
161 scsi_log_completion(scmd, TIMEOUT_ERROR);
163 if (scmd->device->host->hostt->eh_timed_out)
164 switch (scmd->device->host->hostt->eh_timed_out(scmd)) {
169 /* This allows a single retry even of a command
170 * with allowed == 0 */
171 if (scmd->retries++ > scmd->allowed)
173 scsi_add_timer(scmd, scmd->timeout_per_command,
180 if (unlikely(!scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD))) {
181 panic("Error handler thread not present at %p %p %s %d",
182 scmd, scmd->device->host, __FILE__, __LINE__);
187 * scsi_block_when_processing_errors - Prevent cmds from being queued.
188 * @sdev: Device on which we are performing recovery.
191 * We block until the host is out of error recovery, and then check to
192 * see whether the host or the device is offline.
195 * 0 when dev was taken offline by error recovery. 1 OK to proceed.
197 int scsi_block_when_processing_errors(struct scsi_device *sdev)
201 wait_event(sdev->host->host_wait, (sdev->host->shost_state !=
204 online = scsi_device_online(sdev);
206 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: rtn: %d\n", __FUNCTION__,
211 EXPORT_SYMBOL(scsi_block_when_processing_errors);
213 #ifdef CONFIG_SCSI_LOGGING
215 * scsi_eh_prt_fail_stats - Log info on failures.
216 * @shost: scsi host being recovered.
217 * @work_q: Queue of scsi cmds to process.
219 static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost,
220 struct list_head *work_q)
222 struct scsi_cmnd *scmd;
223 struct scsi_device *sdev;
224 int total_failures = 0;
227 int devices_failed = 0;
229 shost_for_each_device(sdev, shost) {
230 list_for_each_entry(scmd, work_q, eh_entry) {
231 if (scmd->device == sdev) {
233 if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD)
240 if (cmd_cancel || cmd_failed) {
241 SCSI_LOG_ERROR_RECOVERY(3,
242 printk("%s: %d:%d:%d:%d cmds failed: %d,"
244 __FUNCTION__, shost->host_no,
245 sdev->channel, sdev->id, sdev->lun,
246 cmd_failed, cmd_cancel));
253 SCSI_LOG_ERROR_RECOVERY(2, printk("Total of %d commands on %d"
254 " devices require eh work\n",
255 total_failures, devices_failed));
260 * scsi_check_sense - Examine scsi cmd sense
261 * @scmd: Cmd to have sense checked.
264 * SUCCESS or FAILED or NEEDS_RETRY
267 * When a deferred error is detected the current command has
268 * not been executed and needs retrying.
270 static int scsi_check_sense(struct scsi_cmnd *scmd)
272 struct scsi_sense_hdr sshdr;
274 if (! scsi_command_normalize_sense(scmd, &sshdr))
275 return FAILED; /* no valid sense data */
277 if (scsi_sense_is_deferred(&sshdr))
281 * Previous logic looked for FILEMARK, EOM or ILI which are
282 * mainly associated with tapes and returned SUCCESS.
284 if (sshdr.response_code == 0x70) {
286 if (scmd->sense_buffer[2] & 0xe0)
290 * descriptor format: look for "stream commands sense data
291 * descriptor" (see SSC-3). Assume single sense data
292 * descriptor. Ignore ILI from SBC-2 READ LONG and WRITE LONG.
294 if ((sshdr.additional_length > 3) &&
295 (scmd->sense_buffer[8] == 0x4) &&
296 (scmd->sense_buffer[11] & 0xe0))
300 switch (sshdr.sense_key) {
303 case RECOVERED_ERROR:
304 return /* soft_error */ SUCCESS;
306 case ABORTED_COMMAND:
311 * if we are expecting a cc/ua because of a bus reset that we
312 * performed, treat this just as a retry. otherwise this is
313 * information that we should pass up to the upper-level driver
314 * so that we can deal with it there.
316 if (scmd->device->expecting_cc_ua) {
317 scmd->device->expecting_cc_ua = 0;
321 * if the device is in the process of becoming ready, we
324 if ((sshdr.asc == 0x04) && (sshdr.ascq == 0x01))
327 * if the device is not started, we need to wake
328 * the error handler to start the motor
330 if (scmd->device->allow_restart &&
331 (sshdr.asc == 0x04) && (sshdr.ascq == 0x02))
335 /* these three are not supported */
337 case VOLUME_OVERFLOW:
345 if (scmd->device->retry_hwerror)
350 case ILLEGAL_REQUEST:
359 * scsi_eh_completed_normally - Disposition a eh cmd on return from LLD.
360 * @scmd: SCSI cmd to examine.
363 * This is *only* called when we are examining the status of commands
364 * queued during error recovery. the main difference here is that we
365 * don't allow for the possibility of retries here, and we are a lot
366 * more restrictive about what we consider acceptable.
368 static int scsi_eh_completed_normally(struct scsi_cmnd *scmd)
371 * first check the host byte, to see if there is anything in there
372 * that would indicate what we need to do.
374 if (host_byte(scmd->result) == DID_RESET) {
376 * rats. we are already in the error handler, so we now
377 * get to try and figure out what to do next. if the sense
378 * is valid, we have a pretty good idea of what to do.
379 * if not, we mark it as FAILED.
381 return scsi_check_sense(scmd);
383 if (host_byte(scmd->result) != DID_OK)
387 * next, check the message byte.
389 if (msg_byte(scmd->result) != COMMAND_COMPLETE)
393 * now, check the status byte to see if this indicates
396 switch (status_byte(scmd->result)) {
398 case COMMAND_TERMINATED:
400 case CHECK_CONDITION:
401 return scsi_check_sense(scmd);
403 case INTERMEDIATE_GOOD:
404 case INTERMEDIATE_C_GOOD:
406 * who knows? FIXME(eric)
411 case RESERVATION_CONFLICT:
419 * scsi_eh_times_out - timeout function for error handling.
420 * @scmd: Cmd that is timing out.
423 * During error handling, the kernel thread will be sleeping waiting
424 * for some action to complete on the device. our only job is to
425 * record that it timed out, and to wake up the thread.
427 static void scsi_eh_times_out(struct scsi_cmnd *scmd)
429 scmd->eh_eflags |= SCSI_EH_REC_TIMEOUT;
430 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd:%p\n", __FUNCTION__,
433 up(scmd->device->host->eh_action);
437 * scsi_eh_done - Completion function for error handling.
438 * @scmd: Cmd that is done.
440 static void scsi_eh_done(struct scsi_cmnd *scmd)
443 * if the timeout handler is already running, then just set the
444 * flag which says we finished late, and return. we have no
445 * way of stopping the timeout handler from running, so we must
446 * always defer to it.
448 if (del_timer(&scmd->eh_timeout)) {
449 scmd->request->rq_status = RQ_SCSI_DONE;
451 SCSI_LOG_ERROR_RECOVERY(3, printk("%s scmd: %p result: %x\n",
452 __FUNCTION__, scmd, scmd->result));
454 up(scmd->device->host->eh_action);
459 * scsi_send_eh_cmnd - send a cmd to a device as part of error recovery.
460 * @scmd: SCSI Cmd to send.
461 * @timeout: Timeout for cmd.
464 * The initialization of the structures is quite a bit different in
465 * this case, and furthermore, there is a different completion handler
466 * vs scsi_dispatch_cmd.
468 * SUCCESS or FAILED or NEEDS_RETRY
470 static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, int timeout)
472 struct scsi_device *sdev = scmd->device;
473 struct Scsi_Host *shost = sdev->host;
474 DECLARE_MUTEX_LOCKED(sem);
479 * we will use a queued command if possible, otherwise we will
480 * emulate the queuing and calling of completion function ourselves.
482 if (sdev->scsi_level <= SCSI_2)
483 scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) |
484 (sdev->lun << 5 & 0xe0);
486 scsi_add_timer(scmd, timeout, scsi_eh_times_out);
489 * set up the semaphore so we wait for the command to complete.
491 shost->eh_action = &sem;
492 scmd->request->rq_status = RQ_SCSI_BUSY;
494 spin_lock_irqsave(shost->host_lock, flags);
496 shost->hostt->queuecommand(scmd, scsi_eh_done);
497 spin_unlock_irqrestore(shost->host_lock, flags);
500 scsi_log_completion(scmd, SUCCESS);
502 shost->eh_action = NULL;
505 * see if timeout. if so, tell the host to forget about it.
506 * in other words, we don't want a callback any more.
508 if (scmd->eh_eflags & SCSI_EH_REC_TIMEOUT) {
509 scmd->eh_eflags &= ~SCSI_EH_REC_TIMEOUT;
512 * as far as the low level driver is
513 * concerned, this command is still active, so
514 * we must give the low level driver a chance
517 * FIXME(eric) - we are not tracking whether we could
518 * abort a timed out command or not. not sure how
519 * we should treat them differently anyways.
521 if (shost->hostt->eh_abort_handler)
522 shost->hostt->eh_abort_handler(scmd);
524 scmd->request->rq_status = RQ_SCSI_DONE;
528 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd: %p, rtn:%x\n",
529 __FUNCTION__, scmd, rtn));
532 * now examine the actual status codes to see whether the command
533 * actually did complete normally.
535 if (rtn == SUCCESS) {
536 rtn = scsi_eh_completed_normally(scmd);
537 SCSI_LOG_ERROR_RECOVERY(3,
538 printk("%s: scsi_eh_completed_normally %x\n",
555 * scsi_request_sense - Request sense data from a particular target.
556 * @scmd: SCSI cmd for request sense.
559 * Some hosts automatically obtain this information, others require
560 * that we obtain it on our own. This function will *not* return until
561 * the command either times out, or it completes.
563 static int scsi_request_sense(struct scsi_cmnd *scmd)
565 static unsigned char generic_sense[6] =
566 {REQUEST_SENSE, 0, 0, 0, 252, 0};
567 unsigned char *scsi_result;
571 memcpy(scmd->cmnd, generic_sense, sizeof(generic_sense));
573 scsi_result = kmalloc(252, GFP_ATOMIC | ((scmd->device->host->hostt->unchecked_isa_dma) ? __GFP_DMA : 0));
576 if (unlikely(!scsi_result)) {
577 printk(KERN_ERR "%s: cannot allocate scsi_result.\n",
583 * zero the sense buffer. some host adapters automatically always
584 * request sense, so it is not a good idea that
585 * scmd->request_buffer and scmd->sense_buffer point to the same
586 * address (db). 0 is not a valid sense code.
588 memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
589 memset(scsi_result, 0, 252);
591 saved_result = scmd->result;
592 scmd->request_buffer = scsi_result;
593 scmd->request_bufflen = 252;
595 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
596 scmd->sc_data_direction = DMA_FROM_DEVICE;
599 rtn = scsi_send_eh_cmnd(scmd, SENSE_TIMEOUT);
601 /* last chance to have valid sense data */
602 if(!SCSI_SENSE_VALID(scmd)) {
603 memcpy(scmd->sense_buffer, scmd->request_buffer,
604 sizeof(scmd->sense_buffer));
610 * when we eventually call scsi_finish, we really wish to complete
611 * the original request, so let's restore the original data. (db)
613 scsi_setup_cmd_retry(scmd);
614 scmd->result = saved_result;
619 * scsi_eh_finish_cmd - Handle a cmd that eh is finished with.
620 * @scmd: Original SCSI cmd that eh has finished.
621 * @done_q: Queue for processed commands.
624 * We don't want to use the normal command completion while we are are
625 * still handling errors - it may cause other commands to be queued,
626 * and that would disturb what we are doing. thus we really want to
627 * keep a list of pending commands for final completion, and once we
628 * are ready to leave error handling we handle completion for real.
630 static void scsi_eh_finish_cmd(struct scsi_cmnd *scmd,
631 struct list_head *done_q)
633 scmd->device->host->host_failed--;
637 * set this back so that the upper level can correctly free up
640 scsi_setup_cmd_retry(scmd);
641 list_move_tail(&scmd->eh_entry, done_q);
645 * scsi_eh_get_sense - Get device sense data.
646 * @work_q: Queue of commands to process.
647 * @done_q: Queue of proccessed commands..
650 * See if we need to request sense information. if so, then get it
651 * now, so we have a better idea of what to do.
654 * This has the unfortunate side effect that if a shost adapter does
655 * not automatically request sense information, that we end up shutting
656 * it down before we request it.
658 * All drivers should request sense information internally these days,
659 * so for now all I have to say is tough noogies if you end up in here.
661 * XXX: Long term this code should go away, but that needs an audit of
664 static int scsi_eh_get_sense(struct list_head *work_q,
665 struct list_head *done_q)
667 struct scsi_cmnd *scmd, *next;
670 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
671 if ((scmd->eh_eflags & SCSI_EH_CANCEL_CMD) ||
672 SCSI_SENSE_VALID(scmd))
675 SCSI_LOG_ERROR_RECOVERY(2, printk("%s: requesting sense"
679 rtn = scsi_request_sense(scmd);
683 SCSI_LOG_ERROR_RECOVERY(3, printk("sense requested for %p"
684 " result %x\n", scmd,
686 SCSI_LOG_ERROR_RECOVERY(3, scsi_print_sense("bh", scmd));
688 rtn = scsi_decide_disposition(scmd);
691 * if the result was normal, then just pass it along to the
695 /* we don't want this command reissued, just
696 * finished with the sense data, so set
697 * retries to the max allowed to ensure it
698 * won't get reissued */
699 scmd->retries = scmd->allowed;
700 else if (rtn != NEEDS_RETRY)
703 scsi_eh_finish_cmd(scmd, done_q);
706 return list_empty(work_q);
710 * scsi_try_to_abort_cmd - Ask host to abort a running command.
711 * @scmd: SCSI cmd to abort from Lower Level.
714 * This function will not return until the user's completion function
715 * has been called. there is no timeout on this operation. if the
716 * author of the low-level driver wishes this operation to be timed,
717 * they can provide this facility themselves. helper functions in
718 * scsi_error.c can be supplied to make this easier to do.
720 static int scsi_try_to_abort_cmd(struct scsi_cmnd *scmd)
722 if (!scmd->device->host->hostt->eh_abort_handler)
726 * scsi_done was called just after the command timed out and before
727 * we had a chance to process it. (db)
729 if (scmd->serial_number == 0)
731 return scmd->device->host->hostt->eh_abort_handler(scmd);
735 * scsi_eh_tur - Send TUR to device.
736 * @scmd: Scsi cmd to send TUR
739 * 0 - Device is ready. 1 - Device NOT ready.
741 static int scsi_eh_tur(struct scsi_cmnd *scmd)
743 static unsigned char tur_command[6] = {TEST_UNIT_READY, 0, 0, 0, 0, 0};
744 int retry_cnt = 1, rtn;
748 memcpy(scmd->cmnd, tur_command, sizeof(tur_command));
751 * zero the sense buffer. the scsi spec mandates that any
752 * untransferred sense data should be interpreted as being zero.
754 memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
756 saved_result = scmd->result;
757 scmd->request_buffer = NULL;
758 scmd->request_bufflen = 0;
760 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
762 scmd->sc_data_direction = DMA_NONE;
764 rtn = scsi_send_eh_cmnd(scmd, SENSE_TIMEOUT);
767 * when we eventually call scsi_finish, we really wish to complete
768 * the original request, so let's restore the original data. (db)
770 scsi_setup_cmd_retry(scmd);
771 scmd->result = saved_result;
774 * hey, we are done. let's look to see what happened.
776 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n",
777 __FUNCTION__, scmd, rtn));
780 else if (rtn == NEEDS_RETRY) {
789 * scsi_eh_abort_cmds - abort canceled commands.
790 * @shost: scsi host being recovered.
791 * @eh_done_q: list_head for processed commands.
794 * Try and see whether or not it makes sense to try and abort the
795 * running command. this only works out to be the case if we have one
796 * command that has timed out. if the command simply failed, it makes
797 * no sense to try and abort the command, since as far as the shost
798 * adapter is concerned, it isn't running.
800 static int scsi_eh_abort_cmds(struct list_head *work_q,
801 struct list_head *done_q)
803 struct scsi_cmnd *scmd, *next;
806 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
807 if (!(scmd->eh_eflags & SCSI_EH_CANCEL_CMD))
809 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting cmd:"
810 "0x%p\n", current->comm,
812 rtn = scsi_try_to_abort_cmd(scmd);
813 if (rtn == SUCCESS) {
814 scmd->eh_eflags &= ~SCSI_EH_CANCEL_CMD;
815 if (!scsi_device_online(scmd->device) ||
816 !scsi_eh_tur(scmd)) {
817 scsi_eh_finish_cmd(scmd, done_q);
821 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting"
828 return list_empty(work_q);
832 * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev
833 * @scmd: SCSI cmd used to send BDR
836 * There is no timeout for this operation. if this operation is
837 * unreliable for a given host, then the host itself needs to put a
838 * timer on it, and set the host back to a consistent state prior to
841 static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd)
845 if (!scmd->device->host->hostt->eh_device_reset_handler)
848 rtn = scmd->device->host->hostt->eh_device_reset_handler(scmd);
849 if (rtn == SUCCESS) {
850 scmd->device->was_reset = 1;
851 scmd->device->expecting_cc_ua = 1;
858 * scsi_eh_try_stu - Send START_UNIT to device.
859 * @scmd: Scsi cmd to send START_UNIT
862 * 0 - Device is ready. 1 - Device NOT ready.
864 static int scsi_eh_try_stu(struct scsi_cmnd *scmd)
866 static unsigned char stu_command[6] = {START_STOP, 0, 0, 0, 1, 0};
870 if (!scmd->device->allow_restart)
873 memcpy(scmd->cmnd, stu_command, sizeof(stu_command));
876 * zero the sense buffer. the scsi spec mandates that any
877 * untransferred sense data should be interpreted as being zero.
879 memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
881 saved_result = scmd->result;
882 scmd->request_buffer = NULL;
883 scmd->request_bufflen = 0;
885 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
887 scmd->sc_data_direction = DMA_NONE;
889 rtn = scsi_send_eh_cmnd(scmd, START_UNIT_TIMEOUT);
892 * when we eventually call scsi_finish, we really wish to complete
893 * the original request, so let's restore the original data. (db)
895 scsi_setup_cmd_retry(scmd);
896 scmd->result = saved_result;
899 * hey, we are done. let's look to see what happened.
901 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n",
902 __FUNCTION__, scmd, rtn));
909 * scsi_eh_stu - send START_UNIT if needed
910 * @shost: scsi host being recovered.
911 * @eh_done_q: list_head for processed commands.
914 * If commands are failing due to not ready, initializing command required,
915 * try revalidating the device, which will end up sending a start unit.
917 static int scsi_eh_stu(struct Scsi_Host *shost,
918 struct list_head *work_q,
919 struct list_head *done_q)
921 struct scsi_cmnd *scmd, *stu_scmd, *next;
922 struct scsi_device *sdev;
924 shost_for_each_device(sdev, shost) {
926 list_for_each_entry(scmd, work_q, eh_entry)
927 if (scmd->device == sdev && SCSI_SENSE_VALID(scmd) &&
928 scsi_check_sense(scmd) == FAILED ) {
936 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending START_UNIT to sdev:"
937 " 0x%p\n", current->comm, sdev));
939 if (!scsi_eh_try_stu(stu_scmd)) {
940 if (!scsi_device_online(sdev) ||
941 !scsi_eh_tur(stu_scmd)) {
942 list_for_each_entry_safe(scmd, next,
944 if (scmd->device == sdev)
945 scsi_eh_finish_cmd(scmd, done_q);
949 SCSI_LOG_ERROR_RECOVERY(3,
950 printk("%s: START_UNIT failed to sdev:"
951 " 0x%p\n", current->comm, sdev));
955 return list_empty(work_q);
960 * scsi_eh_bus_device_reset - send bdr if needed
961 * @shost: scsi host being recovered.
962 * @eh_done_q: list_head for processed commands.
965 * Try a bus device reset. still, look to see whether we have multiple
966 * devices that are jammed or not - if we have multiple devices, it
967 * makes no sense to try bus_device_reset - we really would need to try
968 * a bus_reset instead.
970 static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
971 struct list_head *work_q,
972 struct list_head *done_q)
974 struct scsi_cmnd *scmd, *bdr_scmd, *next;
975 struct scsi_device *sdev;
978 shost_for_each_device(sdev, shost) {
980 list_for_each_entry(scmd, work_q, eh_entry)
981 if (scmd->device == sdev) {
989 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BDR sdev:"
990 " 0x%p\n", current->comm,
992 rtn = scsi_try_bus_device_reset(bdr_scmd);
993 if (rtn == SUCCESS) {
994 if (!scsi_device_online(sdev) ||
995 !scsi_eh_tur(bdr_scmd)) {
996 list_for_each_entry_safe(scmd, next,
998 if (scmd->device == sdev)
999 scsi_eh_finish_cmd(scmd,
1004 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BDR"
1012 return list_empty(work_q);
1016 * scsi_try_bus_reset - ask host to perform a bus reset
1017 * @scmd: SCSI cmd to send bus reset.
1019 static int scsi_try_bus_reset(struct scsi_cmnd *scmd)
1021 unsigned long flags;
1024 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Bus RST\n",
1027 if (!scmd->device->host->hostt->eh_bus_reset_handler)
1030 rtn = scmd->device->host->hostt->eh_bus_reset_handler(scmd);
1032 if (rtn == SUCCESS) {
1033 if (!scmd->device->host->hostt->skip_settle_delay)
1034 ssleep(BUS_RESET_SETTLE_TIME);
1035 spin_lock_irqsave(scmd->device->host->host_lock, flags);
1036 scsi_report_bus_reset(scmd->device->host, scmd->device->channel);
1037 spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
1044 * scsi_try_host_reset - ask host adapter to reset itself
1045 * @scmd: SCSI cmd to send hsot reset.
1047 static int scsi_try_host_reset(struct scsi_cmnd *scmd)
1049 unsigned long flags;
1052 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Host RST\n",
1055 if (!scmd->device->host->hostt->eh_host_reset_handler)
1058 rtn = scmd->device->host->hostt->eh_host_reset_handler(scmd);
1060 if (rtn == SUCCESS) {
1061 if (!scmd->device->host->hostt->skip_settle_delay)
1062 ssleep(HOST_RESET_SETTLE_TIME);
1063 spin_lock_irqsave(scmd->device->host->host_lock, flags);
1064 scsi_report_bus_reset(scmd->device->host, scmd->device->channel);
1065 spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
1072 * scsi_eh_bus_reset - send a bus reset
1073 * @shost: scsi host being recovered.
1074 * @eh_done_q: list_head for processed commands.
1076 static int scsi_eh_bus_reset(struct Scsi_Host *shost,
1077 struct list_head *work_q,
1078 struct list_head *done_q)
1080 struct scsi_cmnd *scmd, *chan_scmd, *next;
1081 unsigned int channel;
1085 * we really want to loop over the various channels, and do this on
1086 * a channel by channel basis. we should also check to see if any
1087 * of the failed commands are on soft_reset devices, and if so, skip
1091 for (channel = 0; channel <= shost->max_channel; channel++) {
1093 list_for_each_entry(scmd, work_q, eh_entry) {
1094 if (channel == scmd->device->channel) {
1098 * FIXME add back in some support for
1099 * soft_reset devices.
1106 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BRST chan:"
1107 " %d\n", current->comm,
1109 rtn = scsi_try_bus_reset(chan_scmd);
1110 if (rtn == SUCCESS) {
1111 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1112 if (channel == scmd->device->channel)
1113 if (!scsi_device_online(scmd->device) ||
1115 scsi_eh_finish_cmd(scmd,
1119 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BRST"
1120 " failed chan: %d\n",
1125 return list_empty(work_q);
1129 * scsi_eh_host_reset - send a host reset
1130 * @work_q: list_head for processed commands.
1131 * @done_q: list_head for processed commands.
1133 static int scsi_eh_host_reset(struct list_head *work_q,
1134 struct list_head *done_q)
1136 struct scsi_cmnd *scmd, *next;
1139 if (!list_empty(work_q)) {
1140 scmd = list_entry(work_q->next,
1141 struct scsi_cmnd, eh_entry);
1143 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending HRST\n"
1146 rtn = scsi_try_host_reset(scmd);
1147 if (rtn == SUCCESS) {
1148 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1149 if (!scsi_device_online(scmd->device) ||
1150 (!scsi_eh_try_stu(scmd) && !scsi_eh_tur(scmd)) ||
1152 scsi_eh_finish_cmd(scmd, done_q);
1155 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: HRST"
1160 return list_empty(work_q);
1164 * scsi_eh_offline_sdevs - offline scsi devices that fail to recover
1165 * @work_q: list_head for processed commands.
1166 * @done_q: list_head for processed commands.
1169 static void scsi_eh_offline_sdevs(struct list_head *work_q,
1170 struct list_head *done_q)
1172 struct scsi_cmnd *scmd, *next;
1174 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1175 printk(KERN_INFO "scsi: Device offlined - not"
1176 " ready after error recovery: host"
1177 " %d channel %d id %d lun %d\n",
1178 scmd->device->host->host_no,
1179 scmd->device->channel,
1182 scsi_device_set_state(scmd->device, SDEV_OFFLINE);
1183 if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD) {
1185 * FIXME: Handle lost cmds.
1188 scsi_eh_finish_cmd(scmd, done_q);
1194 * scsi_decide_disposition - Disposition a cmd on return from LLD.
1195 * @scmd: SCSI cmd to examine.
1198 * This is *only* called when we are examining the status after sending
1199 * out the actual data command. any commands that are queued for error
1200 * recovery (e.g. test_unit_ready) do *not* come through here.
1202 * When this routine returns failed, it means the error handler thread
1203 * is woken. In cases where the error code indicates an error that
1204 * doesn't require the error handler read (i.e. we don't need to
1205 * abort/reset), this function should return SUCCESS.
1207 int scsi_decide_disposition(struct scsi_cmnd *scmd)
1212 * if the device is offline, then we clearly just pass the result back
1213 * up to the top level.
1215 if (!scsi_device_online(scmd->device)) {
1216 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: device offline - report"
1223 * first check the host byte, to see if there is anything in there
1224 * that would indicate what we need to do.
1226 switch (host_byte(scmd->result)) {
1227 case DID_PASSTHROUGH:
1229 * no matter what, pass this through to the upper layer.
1230 * nuke this special code so that it looks like we are saying
1233 scmd->result &= 0xff00ffff;
1237 * looks good. drop through, and check the next byte.
1240 case DID_NO_CONNECT:
1241 case DID_BAD_TARGET:
1244 * note - this means that we just report the status back
1245 * to the top level driver, not that we actually think
1246 * that it indicates SUCCESS.
1250 * when the low level driver returns did_soft_error,
1251 * it is responsible for keeping an internal retry counter
1252 * in order to avoid endless loops (db)
1254 * actually this is a bug in this function here. we should
1255 * be mindful of the maximum number of retries specified
1256 * and not get stuck in a loop.
1258 case DID_SOFT_ERROR:
1264 return ADD_TO_MLQUEUE;
1267 if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
1268 status_byte(scmd->result) == RESERVATION_CONFLICT)
1270 * execute reservation conflict processing code
1281 * when we scan the bus, we get timeout messages for
1282 * these commands if there is no device available.
1283 * other hosts report did_no_connect for the same thing.
1285 if ((scmd->cmnd[0] == TEST_UNIT_READY ||
1286 scmd->cmnd[0] == INQUIRY)) {
1298 * next, check the message byte.
1300 if (msg_byte(scmd->result) != COMMAND_COMPLETE)
1304 * check the status byte to see if this indicates anything special.
1306 switch (status_byte(scmd->result)) {
1309 * the case of trying to send too many commands to a
1310 * tagged queueing device.
1314 * device can't talk to us at the moment. Should only
1315 * occur (SAM-3) when the task queue is empty, so will cause
1316 * the empty queue handling to trigger a stall in the
1319 return ADD_TO_MLQUEUE;
1321 case COMMAND_TERMINATED:
1324 case CHECK_CONDITION:
1325 rtn = scsi_check_sense(scmd);
1326 if (rtn == NEEDS_RETRY)
1328 /* if rtn == FAILED, we have no sense information;
1329 * returning FAILED will wake the error handler thread
1330 * to collect the sense and redo the decide
1333 case CONDITION_GOOD:
1334 case INTERMEDIATE_GOOD:
1335 case INTERMEDIATE_C_GOOD:
1338 * who knows? FIXME(eric)
1342 case RESERVATION_CONFLICT:
1343 printk(KERN_INFO "scsi: reservation conflict: host"
1344 " %d channel %d id %d lun %d\n",
1345 scmd->device->host->host_no, scmd->device->channel,
1346 scmd->device->id, scmd->device->lun);
1347 return SUCCESS; /* causes immediate i/o error */
1355 /* we requeue for retry because the error was retryable, and
1356 * the request was not marked fast fail. Note that above,
1357 * even if the request is marked fast fail, we still requeue
1358 * for queue congestion conditions (QUEUE_FULL or BUSY) */
1359 if ((++scmd->retries) < scmd->allowed
1360 && !blk_noretry_request(scmd->request)) {
1364 * no more retries - report this one back to upper level.
1371 * scsi_eh_lock_done - done function for eh door lock request
1372 * @scmd: SCSI command block for the door lock request
1375 * We completed the asynchronous door lock request, and it has either
1376 * locked the door or failed. We must free the command structures
1377 * associated with this request.
1379 static void scsi_eh_lock_done(struct scsi_cmnd *scmd)
1381 struct scsi_request *sreq = scmd->sc_request;
1383 scsi_release_request(sreq);
1388 * scsi_eh_lock_door - Prevent medium removal for the specified device
1389 * @sdev: SCSI device to prevent medium removal
1392 * We must be called from process context; scsi_allocate_request()
1396 * We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the
1397 * head of the devices request queue, and continue.
1400 * scsi_allocate_request() may sleep waiting for existing requests to
1401 * be processed. However, since we haven't kicked off any request
1402 * processing for this host, this may deadlock.
1404 * If scsi_allocate_request() fails for what ever reason, we
1405 * completely forget to lock the door.
1407 static void scsi_eh_lock_door(struct scsi_device *sdev)
1409 struct scsi_request *sreq = scsi_allocate_request(sdev, GFP_KERNEL);
1411 if (unlikely(!sreq)) {
1412 printk(KERN_ERR "%s: request allocate failed,"
1413 "prevent media removal cmd not sent\n", __FUNCTION__);
1417 sreq->sr_cmnd[0] = ALLOW_MEDIUM_REMOVAL;
1418 sreq->sr_cmnd[1] = 0;
1419 sreq->sr_cmnd[2] = 0;
1420 sreq->sr_cmnd[3] = 0;
1421 sreq->sr_cmnd[4] = SCSI_REMOVAL_PREVENT;
1422 sreq->sr_cmnd[5] = 0;
1423 sreq->sr_data_direction = DMA_NONE;
1424 sreq->sr_bufflen = 0;
1425 sreq->sr_buffer = NULL;
1426 sreq->sr_allowed = 5;
1427 sreq->sr_done = scsi_eh_lock_done;
1428 sreq->sr_timeout_per_command = 10 * HZ;
1429 sreq->sr_cmd_len = COMMAND_SIZE(sreq->sr_cmnd[0]);
1431 scsi_insert_special_req(sreq, 1);
1436 * scsi_restart_operations - restart io operations to the specified host.
1437 * @shost: Host we are restarting.
1440 * When we entered the error handler, we blocked all further i/o to
1441 * this device. we need to 'reverse' this process.
1443 static void scsi_restart_operations(struct Scsi_Host *shost)
1445 struct scsi_device *sdev;
1448 * If the door was locked, we need to insert a door lock request
1449 * onto the head of the SCSI request queue for the device. There
1450 * is no point trying to lock the door of an off-line device.
1452 shost_for_each_device(sdev, shost) {
1453 if (scsi_device_online(sdev) && sdev->locked)
1454 scsi_eh_lock_door(sdev);
1458 * next free up anything directly waiting upon the host. this
1459 * will be requests for character device operations, and also for
1460 * ioctls to queued block devices.
1462 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: waking up host to restart\n",
1465 scsi_host_set_state(shost, SHOST_RUNNING);
1467 wake_up(&shost->host_wait);
1470 * finally we need to re-initiate requests that may be pending. we will
1471 * have had everything blocked while error handling is taking place, and
1472 * now that error recovery is done, we will need to ensure that these
1473 * requests are started.
1475 scsi_run_host_queues(shost);
1479 * scsi_eh_ready_devs - check device ready state and recover if not.
1480 * @shost: host to be recovered.
1481 * @eh_done_q: list_head for processed commands.
1484 static void scsi_eh_ready_devs(struct Scsi_Host *shost,
1485 struct list_head *work_q,
1486 struct list_head *done_q)
1488 if (!scsi_eh_stu(shost, work_q, done_q))
1489 if (!scsi_eh_bus_device_reset(shost, work_q, done_q))
1490 if (!scsi_eh_bus_reset(shost, work_q, done_q))
1491 if (!scsi_eh_host_reset(work_q, done_q))
1492 scsi_eh_offline_sdevs(work_q, done_q);
1496 * scsi_eh_flush_done_q - finish processed commands or retry them.
1497 * @done_q: list_head of processed commands.
1500 static void scsi_eh_flush_done_q(struct list_head *done_q)
1502 struct scsi_cmnd *scmd, *next;
1504 list_for_each_entry_safe(scmd, next, done_q, eh_entry) {
1505 list_del_init(&scmd->eh_entry);
1506 if (scsi_device_online(scmd->device) &&
1507 !blk_noretry_request(scmd->request) &&
1508 (++scmd->retries < scmd->allowed)) {
1509 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush"
1513 scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY);
1516 * If just we got sense for the device (called
1517 * scsi_eh_get_sense), scmd->result is already
1518 * set, do not set DRIVER_TIMEOUT.
1521 scmd->result |= (DRIVER_TIMEOUT << 24);
1522 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush finish"
1524 current->comm, scmd));
1525 scsi_finish_command(scmd);
1531 * scsi_unjam_host - Attempt to fix a host which has a cmd that failed.
1532 * @shost: Host to unjam.
1535 * When we come in here, we *know* that all commands on the bus have
1536 * either completed, failed or timed out. we also know that no further
1537 * commands are being sent to the host, so things are relatively quiet
1538 * and we have freedom to fiddle with things as we wish.
1540 * This is only the *default* implementation. it is possible for
1541 * individual drivers to supply their own version of this function, and
1542 * if the maintainer wishes to do this, it is strongly suggested that
1543 * this function be taken as a template and modified. this function
1544 * was designed to correctly handle problems for about 95% of the
1545 * different cases out there, and it should always provide at least a
1546 * reasonable amount of error recovery.
1548 * Any command marked 'failed' or 'timeout' must eventually have
1549 * scsi_finish_cmd() called for it. we do all of the retry stuff
1550 * here, so when we restart the host after we return it should have an
1553 static void scsi_unjam_host(struct Scsi_Host *shost)
1555 unsigned long flags;
1556 LIST_HEAD(eh_work_q);
1557 LIST_HEAD(eh_done_q);
1559 spin_lock_irqsave(shost->host_lock, flags);
1560 list_splice_init(&shost->eh_cmd_q, &eh_work_q);
1561 spin_unlock_irqrestore(shost->host_lock, flags);
1563 SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(shost, &eh_work_q));
1565 if (!scsi_eh_get_sense(&eh_work_q, &eh_done_q))
1566 if (!scsi_eh_abort_cmds(&eh_work_q, &eh_done_q))
1567 scsi_eh_ready_devs(shost, &eh_work_q, &eh_done_q);
1569 scsi_eh_flush_done_q(&eh_done_q);
1573 * scsi_error_handler - Handle errors/timeouts of SCSI cmds.
1574 * @data: Host for which we are running.
1577 * This is always run in the context of a kernel thread. The idea is
1578 * that we start this thing up when the kernel starts up (one per host
1579 * that we detect), and it immediately goes to sleep and waits for some
1580 * event (i.e. failure). When this takes place, we have the job of
1581 * trying to unjam the bus and restarting things.
1583 int scsi_error_handler(void *data)
1585 struct Scsi_Host *shost = (struct Scsi_Host *) data;
1587 DECLARE_MUTEX_LOCKED(sem);
1589 current->flags |= PF_NOFREEZE;
1590 shost->eh_wait = &sem;
1593 * Wake up the thread that created us.
1595 SCSI_LOG_ERROR_RECOVERY(3, printk("Wake up parent of"
1596 " scsi_eh_%d\n",shost->host_no));
1600 * If we get a signal, it means we are supposed to go
1601 * away and die. This typically happens if the user is
1602 * trying to unload a module.
1604 SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler"
1606 " sleeping\n",shost->host_no));
1609 * Note - we always use down_interruptible with the semaphore
1610 * even if the module was loaded as part of the kernel. The
1611 * reason is that down() will cause this thread to be counted
1612 * in the load average as a running process, and down
1613 * interruptible doesn't. Given that we need to allow this
1614 * thread to die if the driver was loaded as a module, using
1615 * semaphores isn't unreasonable.
1617 down_interruptible(&sem);
1618 if (kthread_should_stop())
1621 SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler"
1622 " scsi_eh_%d waking"
1623 " up\n",shost->host_no));
1625 shost->eh_active = 1;
1628 * We have a host that is failing for some reason. Figure out
1629 * what we need to do to get it up and online again (if we can).
1630 * If we fail, we end up taking the thing offline.
1632 if (shost->hostt->eh_strategy_handler)
1633 rtn = shost->hostt->eh_strategy_handler(shost);
1635 scsi_unjam_host(shost);
1637 shost->eh_active = 0;
1640 * Note - if the above fails completely, the action is to take
1641 * individual devices offline and flush the queue of any
1642 * outstanding requests that may have been pending. When we
1643 * restart, we restart any I/O to any other devices on the bus
1644 * which are still online.
1646 scsi_restart_operations(shost);
1650 SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler scsi_eh_%d"
1651 " exiting\n",shost->host_no));
1654 * Make sure that nobody tries to wake us up again.
1656 shost->eh_wait = NULL;
1661 * Function: scsi_report_bus_reset()
1663 * Purpose: Utility function used by low-level drivers to report that
1664 * they have observed a bus reset on the bus being handled.
1666 * Arguments: shost - Host in question
1667 * channel - channel on which reset was observed.
1671 * Lock status: Host lock must be held.
1673 * Notes: This only needs to be called if the reset is one which
1674 * originates from an unknown location. Resets originated
1675 * by the mid-level itself don't need to call this, but there
1676 * should be no harm.
1678 * The main purpose of this is to make sure that a CHECK_CONDITION
1679 * is properly treated.
1681 void scsi_report_bus_reset(struct Scsi_Host *shost, int channel)
1683 struct scsi_device *sdev;
1685 __shost_for_each_device(sdev, shost) {
1686 if (channel == sdev->channel) {
1687 sdev->was_reset = 1;
1688 sdev->expecting_cc_ua = 1;
1692 EXPORT_SYMBOL(scsi_report_bus_reset);
1695 * Function: scsi_report_device_reset()
1697 * Purpose: Utility function used by low-level drivers to report that
1698 * they have observed a device reset on the device being handled.
1700 * Arguments: shost - Host in question
1701 * channel - channel on which reset was observed
1702 * target - target on which reset was observed
1706 * Lock status: Host lock must be held
1708 * Notes: This only needs to be called if the reset is one which
1709 * originates from an unknown location. Resets originated
1710 * by the mid-level itself don't need to call this, but there
1711 * should be no harm.
1713 * The main purpose of this is to make sure that a CHECK_CONDITION
1714 * is properly treated.
1716 void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
1718 struct scsi_device *sdev;
1720 __shost_for_each_device(sdev, shost) {
1721 if (channel == sdev->channel &&
1722 target == sdev->id) {
1723 sdev->was_reset = 1;
1724 sdev->expecting_cc_ua = 1;
1728 EXPORT_SYMBOL(scsi_report_device_reset);
1731 scsi_reset_provider_done_command(struct scsi_cmnd *scmd)
1736 * Function: scsi_reset_provider
1738 * Purpose: Send requested reset to a bus or device at any phase.
1740 * Arguments: device - device to send reset to
1741 * flag - reset type (see scsi.h)
1743 * Returns: SUCCESS/FAILURE.
1745 * Notes: This is used by the SCSI Generic driver to provide
1746 * Bus/Device reset capability.
1749 scsi_reset_provider(struct scsi_device *dev, int flag)
1751 struct scsi_cmnd *scmd = scsi_get_command(dev, GFP_KERNEL);
1755 scmd->request = &req;
1756 memset(&scmd->eh_timeout, 0, sizeof(scmd->eh_timeout));
1757 scmd->request->rq_status = RQ_SCSI_BUSY;
1759 memset(&scmd->cmnd, '\0', sizeof(scmd->cmnd));
1761 scmd->scsi_done = scsi_reset_provider_done_command;
1763 scmd->buffer = NULL;
1765 scmd->request_buffer = NULL;
1766 scmd->request_bufflen = 0;
1770 scmd->sc_data_direction = DMA_BIDIRECTIONAL;
1771 scmd->sc_request = NULL;
1772 scmd->sc_magic = SCSI_CMND_MAGIC;
1774 init_timer(&scmd->eh_timeout);
1777 * Sometimes the command can get back into the timer chain,
1778 * so use the pid as an identifier.
1783 case SCSI_TRY_RESET_DEVICE:
1784 rtn = scsi_try_bus_device_reset(scmd);
1788 case SCSI_TRY_RESET_BUS:
1789 rtn = scsi_try_bus_reset(scmd);
1793 case SCSI_TRY_RESET_HOST:
1794 rtn = scsi_try_host_reset(scmd);
1800 scsi_next_command(scmd);
1803 EXPORT_SYMBOL(scsi_reset_provider);
1806 * scsi_normalize_sense - normalize main elements from either fixed or
1807 * descriptor sense data format into a common format.
1809 * @sense_buffer: byte array containing sense data returned by device
1810 * @sb_len: number of valid bytes in sense_buffer
1811 * @sshdr: pointer to instance of structure that common
1812 * elements are written to.
1815 * The "main elements" from sense data are: response_code, sense_key,
1816 * asc, ascq and additional_length (only for descriptor format).
1818 * Typically this function can be called after a device has
1819 * responded to a SCSI command with the CHECK_CONDITION status.
1822 * 1 if valid sense data information found, else 0;
1824 int scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
1825 struct scsi_sense_hdr *sshdr)
1827 if (!sense_buffer || !sb_len || (sense_buffer[0] & 0x70) != 0x70)
1830 memset(sshdr, 0, sizeof(struct scsi_sense_hdr));
1832 sshdr->response_code = (sense_buffer[0] & 0x7f);
1833 if (sshdr->response_code >= 0x72) {
1838 sshdr->sense_key = (sense_buffer[1] & 0xf);
1840 sshdr->asc = sense_buffer[2];
1842 sshdr->ascq = sense_buffer[3];
1844 sshdr->additional_length = sense_buffer[7];
1850 sshdr->sense_key = (sense_buffer[2] & 0xf);
1852 sb_len = (sb_len < (sense_buffer[7] + 8)) ?
1853 sb_len : (sense_buffer[7] + 8);
1855 sshdr->asc = sense_buffer[12];
1857 sshdr->ascq = sense_buffer[13];
1863 EXPORT_SYMBOL(scsi_normalize_sense);
1865 int scsi_request_normalize_sense(struct scsi_request *sreq,
1866 struct scsi_sense_hdr *sshdr)
1868 return scsi_normalize_sense(sreq->sr_sense_buffer,
1869 sizeof(sreq->sr_sense_buffer), sshdr);
1871 EXPORT_SYMBOL(scsi_request_normalize_sense);
1873 int scsi_command_normalize_sense(struct scsi_cmnd *cmd,
1874 struct scsi_sense_hdr *sshdr)
1876 return scsi_normalize_sense(cmd->sense_buffer,
1877 sizeof(cmd->sense_buffer), sshdr);
1879 EXPORT_SYMBOL(scsi_command_normalize_sense);
1882 * scsi_sense_desc_find - search for a given descriptor type in
1883 * descriptor sense data format.
1885 * @sense_buffer: byte array of descriptor format sense data
1886 * @sb_len: number of valid bytes in sense_buffer
1887 * @desc_type: value of descriptor type to find
1888 * (e.g. 0 -> information)
1891 * only valid when sense data is in descriptor format
1894 * pointer to start of (first) descriptor if found else NULL
1896 const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
1899 int add_sen_len, add_len, desc_len, k;
1902 if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7])))
1904 if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73))
1906 add_sen_len = (add_sen_len < (sb_len - 8)) ?
1907 add_sen_len : (sb_len - 8);
1908 descp = &sense_buffer[8];
1909 for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) {
1911 add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
1912 desc_len = add_len + 2;
1913 if (descp[0] == desc_type)
1915 if (add_len < 0) // short descriptor ??
1920 EXPORT_SYMBOL(scsi_sense_desc_find);
1923 * scsi_get_sense_info_fld - attempts to get information field from
1924 * sense data (either fixed or descriptor format)
1926 * @sense_buffer: byte array of sense data
1927 * @sb_len: number of valid bytes in sense_buffer
1928 * @info_out: pointer to 64 integer where 8 or 4 byte information
1929 * field will be placed if found.
1932 * 1 if information field found, 0 if not found.
1934 int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len,
1943 switch (sense_buffer[0] & 0x7f) {
1946 if (sense_buffer[0] & 0x80) {
1947 *info_out = (sense_buffer[3] << 24) +
1948 (sense_buffer[4] << 16) +
1949 (sense_buffer[5] << 8) + sense_buffer[6];
1955 ucp = scsi_sense_desc_find(sense_buffer, sb_len,
1957 if (ucp && (0xa == ucp[1])) {
1959 for (j = 0; j < 8; ++j) {
1972 EXPORT_SYMBOL(scsi_get_sense_info_fld);