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) {
53 wake_up_process(shost->ehandler);
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;
76 spin_lock_irqsave(shost->host_lock, flags);
77 if (scsi_host_set_state(shost, SHOST_RECOVERY))
78 if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY))
82 scmd->eh_eflags |= eh_flag;
83 list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q);
85 scsi_eh_wakeup(shost);
87 spin_unlock_irqrestore(shost->host_lock, flags);
92 * scsi_add_timer - Start timeout timer for a single scsi command.
93 * @scmd: scsi command that is about to start running.
94 * @timeout: amount of time to allow this command to run.
95 * @complete: timeout function to call if timer isn't canceled.
98 * This should be turned into an inline function. Each scsi command
99 * has its own timer, and as it is added to the queue, we set up the
100 * timer. When the command completes, we cancel the timer.
102 void scsi_add_timer(struct scsi_cmnd *scmd, int timeout,
103 void (*complete)(struct scsi_cmnd *))
107 * If the clock was already running for this command, then
108 * first delete the timer. The timer handling code gets rather
109 * confused if we don't do this.
111 if (scmd->eh_timeout.function)
112 del_timer(&scmd->eh_timeout);
114 scmd->eh_timeout.data = (unsigned long)scmd;
115 scmd->eh_timeout.expires = jiffies + timeout;
116 scmd->eh_timeout.function = (void (*)(unsigned long)) complete;
118 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p, time:"
119 " %d, (%p)\n", __FUNCTION__,
120 scmd, timeout, complete));
122 add_timer(&scmd->eh_timeout);
126 * scsi_delete_timer - Delete/cancel timer for a given function.
127 * @scmd: Cmd that we are canceling timer for
130 * This should be turned into an inline function.
133 * 1 if we were able to detach the timer. 0 if we blew it, and the
134 * timer function has already started to run.
136 int scsi_delete_timer(struct scsi_cmnd *scmd)
140 rtn = del_timer(&scmd->eh_timeout);
142 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p,"
143 " rtn: %d\n", __FUNCTION__,
146 scmd->eh_timeout.data = (unsigned long)NULL;
147 scmd->eh_timeout.function = NULL;
153 * scsi_times_out - Timeout function for normal scsi commands.
154 * @scmd: Cmd that is timing out.
157 * We do not need to lock this. There is the potential for a race
158 * only in that the normal completion handling might run, but if the
159 * normal completion function determines that the timer has already
160 * fired, then it mustn't do anything.
162 void scsi_times_out(struct scsi_cmnd *scmd)
164 scsi_log_completion(scmd, TIMEOUT_ERROR);
166 if (scmd->device->host->hostt->eh_timed_out)
167 switch (scmd->device->host->hostt->eh_timed_out(scmd)) {
172 /* This allows a single retry even of a command
173 * with allowed == 0 */
174 if (scmd->retries++ > scmd->allowed)
176 scsi_add_timer(scmd, scmd->timeout_per_command,
183 if (unlikely(!scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD))) {
184 scmd->result |= DID_TIME_OUT << 16;
190 * scsi_block_when_processing_errors - Prevent cmds from being queued.
191 * @sdev: Device on which we are performing recovery.
194 * We block until the host is out of error recovery, and then check to
195 * see whether the host or the device is offline.
198 * 0 when dev was taken offline by error recovery. 1 OK to proceed.
200 int scsi_block_when_processing_errors(struct scsi_device *sdev)
204 wait_event(sdev->host->host_wait, !scsi_host_in_recovery(sdev->host));
206 online = scsi_device_online(sdev);
208 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: rtn: %d\n", __FUNCTION__,
213 EXPORT_SYMBOL(scsi_block_when_processing_errors);
215 #ifdef CONFIG_SCSI_LOGGING
217 * scsi_eh_prt_fail_stats - Log info on failures.
218 * @shost: scsi host being recovered.
219 * @work_q: Queue of scsi cmds to process.
221 static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost,
222 struct list_head *work_q)
224 struct scsi_cmnd *scmd;
225 struct scsi_device *sdev;
226 int total_failures = 0;
229 int devices_failed = 0;
231 shost_for_each_device(sdev, shost) {
232 list_for_each_entry(scmd, work_q, eh_entry) {
233 if (scmd->device == sdev) {
235 if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD)
242 if (cmd_cancel || cmd_failed) {
243 SCSI_LOG_ERROR_RECOVERY(3,
244 sdev_printk(KERN_INFO, sdev,
245 "%s: cmds failed: %d, cancel: %d\n",
246 __FUNCTION__, cmd_failed,
254 SCSI_LOG_ERROR_RECOVERY(2, printk("Total of %d commands on %d"
255 " devices require eh work\n",
256 total_failures, devices_failed));
261 * scsi_check_sense - Examine scsi cmd sense
262 * @scmd: Cmd to have sense checked.
265 * SUCCESS or FAILED or NEEDS_RETRY
268 * When a deferred error is detected the current command has
269 * not been executed and needs retrying.
271 static int scsi_check_sense(struct scsi_cmnd *scmd)
273 struct scsi_sense_hdr sshdr;
275 if (! scsi_command_normalize_sense(scmd, &sshdr))
276 return FAILED; /* no valid sense data */
278 if (scsi_sense_is_deferred(&sshdr))
282 * Previous logic looked for FILEMARK, EOM or ILI which are
283 * mainly associated with tapes and returned SUCCESS.
285 if (sshdr.response_code == 0x70) {
287 if (scmd->sense_buffer[2] & 0xe0)
291 * descriptor format: look for "stream commands sense data
292 * descriptor" (see SSC-3). Assume single sense data
293 * descriptor. Ignore ILI from SBC-2 READ LONG and WRITE LONG.
295 if ((sshdr.additional_length > 3) &&
296 (scmd->sense_buffer[8] == 0x4) &&
297 (scmd->sense_buffer[11] & 0xe0))
301 switch (sshdr.sense_key) {
304 case RECOVERED_ERROR:
305 return /* soft_error */ SUCCESS;
307 case ABORTED_COMMAND:
312 * if we are expecting a cc/ua because of a bus reset that we
313 * performed, treat this just as a retry. otherwise this is
314 * information that we should pass up to the upper-level driver
315 * so that we can deal with it there.
317 if (scmd->device->expecting_cc_ua) {
318 scmd->device->expecting_cc_ua = 0;
322 * if the device is in the process of becoming ready, we
325 if ((sshdr.asc == 0x04) && (sshdr.ascq == 0x01))
328 * if the device is not started, we need to wake
329 * the error handler to start the motor
331 if (scmd->device->allow_restart &&
332 (sshdr.asc == 0x04) && (sshdr.ascq == 0x02))
336 /* these three are not supported */
338 case VOLUME_OVERFLOW:
346 if (scmd->device->retry_hwerror)
351 case ILLEGAL_REQUEST:
360 * scsi_eh_completed_normally - Disposition a eh cmd on return from LLD.
361 * @scmd: SCSI cmd to examine.
364 * This is *only* called when we are examining the status of commands
365 * queued during error recovery. the main difference here is that we
366 * don't allow for the possibility of retries here, and we are a lot
367 * more restrictive about what we consider acceptable.
369 static int scsi_eh_completed_normally(struct scsi_cmnd *scmd)
372 * first check the host byte, to see if there is anything in there
373 * that would indicate what we need to do.
375 if (host_byte(scmd->result) == DID_RESET) {
377 * rats. we are already in the error handler, so we now
378 * get to try and figure out what to do next. if the sense
379 * is valid, we have a pretty good idea of what to do.
380 * if not, we mark it as FAILED.
382 return scsi_check_sense(scmd);
384 if (host_byte(scmd->result) != DID_OK)
388 * next, check the message byte.
390 if (msg_byte(scmd->result) != COMMAND_COMPLETE)
394 * now, check the status byte to see if this indicates
397 switch (status_byte(scmd->result)) {
399 case COMMAND_TERMINATED:
401 case CHECK_CONDITION:
402 return scsi_check_sense(scmd);
404 case INTERMEDIATE_GOOD:
405 case INTERMEDIATE_C_GOOD:
407 * who knows? FIXME(eric)
412 case RESERVATION_CONFLICT:
420 * scsi_eh_times_out - timeout function for error handling.
421 * @scmd: Cmd that is timing out.
424 * During error handling, the kernel thread will be sleeping waiting
425 * for some action to complete on the device. our only job is to
426 * record that it timed out, and to wake up the thread.
428 static void scsi_eh_times_out(struct scsi_cmnd *scmd)
430 scmd->eh_eflags |= SCSI_EH_REC_TIMEOUT;
431 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd:%p\n", __FUNCTION__,
434 up(scmd->device->host->eh_action);
438 * scsi_eh_done - Completion function for error handling.
439 * @scmd: Cmd that is done.
441 static void scsi_eh_done(struct scsi_cmnd *scmd)
444 * if the timeout handler is already running, then just set the
445 * flag which says we finished late, and return. we have no
446 * way of stopping the timeout handler from running, so we must
447 * always defer to it.
449 if (del_timer(&scmd->eh_timeout)) {
450 scmd->request->rq_status = RQ_SCSI_DONE;
452 SCSI_LOG_ERROR_RECOVERY(3, printk("%s scmd: %p result: %x\n",
453 __FUNCTION__, scmd, scmd->result));
455 up(scmd->device->host->eh_action);
460 * scsi_send_eh_cmnd - send a cmd to a device as part of error recovery.
461 * @scmd: SCSI Cmd to send.
462 * @timeout: Timeout for cmd.
465 * The initialization of the structures is quite a bit different in
466 * this case, and furthermore, there is a different completion handler
467 * vs scsi_dispatch_cmd.
469 * SUCCESS or FAILED or NEEDS_RETRY
471 static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, int timeout)
473 struct scsi_device *sdev = scmd->device;
474 struct Scsi_Host *shost = sdev->host;
475 DECLARE_MUTEX_LOCKED(sem);
480 * we will use a queued command if possible, otherwise we will
481 * emulate the queuing and calling of completion function ourselves.
483 if (sdev->scsi_level <= SCSI_2)
484 scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) |
485 (sdev->lun << 5 & 0xe0);
487 scsi_add_timer(scmd, timeout, scsi_eh_times_out);
490 * set up the semaphore so we wait for the command to complete.
492 shost->eh_action = &sem;
493 scmd->request->rq_status = RQ_SCSI_BUSY;
495 spin_lock_irqsave(shost->host_lock, flags);
497 shost->hostt->queuecommand(scmd, scsi_eh_done);
498 spin_unlock_irqrestore(shost->host_lock, flags);
501 scsi_log_completion(scmd, SUCCESS);
503 shost->eh_action = NULL;
506 * see if timeout. if so, tell the host to forget about it.
507 * in other words, we don't want a callback any more.
509 if (scmd->eh_eflags & SCSI_EH_REC_TIMEOUT) {
510 scmd->eh_eflags &= ~SCSI_EH_REC_TIMEOUT;
513 * as far as the low level driver is
514 * concerned, this command is still active, so
515 * we must give the low level driver a chance
518 * FIXME(eric) - we are not tracking whether we could
519 * abort a timed out command or not. not sure how
520 * we should treat them differently anyways.
522 if (shost->hostt->eh_abort_handler)
523 shost->hostt->eh_abort_handler(scmd);
525 scmd->request->rq_status = RQ_SCSI_DONE;
529 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd: %p, rtn:%x\n",
530 __FUNCTION__, scmd, rtn));
533 * now examine the actual status codes to see whether the command
534 * actually did complete normally.
536 if (rtn == SUCCESS) {
537 rtn = scsi_eh_completed_normally(scmd);
538 SCSI_LOG_ERROR_RECOVERY(3,
539 printk("%s: scsi_eh_completed_normally %x\n",
556 * scsi_request_sense - Request sense data from a particular target.
557 * @scmd: SCSI cmd for request sense.
560 * Some hosts automatically obtain this information, others require
561 * that we obtain it on our own. This function will *not* return until
562 * the command either times out, or it completes.
564 static int scsi_request_sense(struct scsi_cmnd *scmd)
566 static unsigned char generic_sense[6] =
567 {REQUEST_SENSE, 0, 0, 0, 252, 0};
568 unsigned char *scsi_result;
572 memcpy(scmd->cmnd, generic_sense, sizeof(generic_sense));
574 scsi_result = kmalloc(252, GFP_ATOMIC | ((scmd->device->host->hostt->unchecked_isa_dma) ? __GFP_DMA : 0));
577 if (unlikely(!scsi_result)) {
578 printk(KERN_ERR "%s: cannot allocate scsi_result.\n",
584 * zero the sense buffer. some host adapters automatically always
585 * request sense, so it is not a good idea that
586 * scmd->request_buffer and scmd->sense_buffer point to the same
587 * address (db). 0 is not a valid sense code.
589 memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
590 memset(scsi_result, 0, 252);
592 saved_result = scmd->result;
593 scmd->request_buffer = scsi_result;
594 scmd->request_bufflen = 252;
596 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
597 scmd->sc_data_direction = DMA_FROM_DEVICE;
600 rtn = scsi_send_eh_cmnd(scmd, SENSE_TIMEOUT);
602 /* last chance to have valid sense data */
603 if(!SCSI_SENSE_VALID(scmd)) {
604 memcpy(scmd->sense_buffer, scmd->request_buffer,
605 sizeof(scmd->sense_buffer));
611 * when we eventually call scsi_finish, we really wish to complete
612 * the original request, so let's restore the original data. (db)
614 scsi_setup_cmd_retry(scmd);
615 scmd->result = saved_result;
620 * scsi_eh_finish_cmd - Handle a cmd that eh is finished with.
621 * @scmd: Original SCSI cmd that eh has finished.
622 * @done_q: Queue for processed commands.
625 * We don't want to use the normal command completion while we are are
626 * still handling errors - it may cause other commands to be queued,
627 * and that would disturb what we are doing. thus we really want to
628 * keep a list of pending commands for final completion, and once we
629 * are ready to leave error handling we handle completion for real.
631 static void scsi_eh_finish_cmd(struct scsi_cmnd *scmd,
632 struct list_head *done_q)
634 scmd->device->host->host_failed--;
638 * set this back so that the upper level can correctly free up
641 scsi_setup_cmd_retry(scmd);
642 list_move_tail(&scmd->eh_entry, done_q);
646 * scsi_eh_get_sense - Get device sense data.
647 * @work_q: Queue of commands to process.
648 * @done_q: Queue of proccessed commands..
651 * See if we need to request sense information. if so, then get it
652 * now, so we have a better idea of what to do.
655 * This has the unfortunate side effect that if a shost adapter does
656 * not automatically request sense information, that we end up shutting
657 * it down before we request it.
659 * All drivers should request sense information internally these days,
660 * so for now all I have to say is tough noogies if you end up in here.
662 * XXX: Long term this code should go away, but that needs an audit of
665 static int scsi_eh_get_sense(struct list_head *work_q,
666 struct list_head *done_q)
668 struct scsi_cmnd *scmd, *next;
671 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
672 if ((scmd->eh_eflags & SCSI_EH_CANCEL_CMD) ||
673 SCSI_SENSE_VALID(scmd))
676 SCSI_LOG_ERROR_RECOVERY(2, printk("%s: requesting sense"
680 rtn = scsi_request_sense(scmd);
684 SCSI_LOG_ERROR_RECOVERY(3, printk("sense requested for %p"
685 " result %x\n", scmd,
687 SCSI_LOG_ERROR_RECOVERY(3, scsi_print_sense("bh", scmd));
689 rtn = scsi_decide_disposition(scmd);
692 * if the result was normal, then just pass it along to the
696 /* we don't want this command reissued, just
697 * finished with the sense data, so set
698 * retries to the max allowed to ensure it
699 * won't get reissued */
700 scmd->retries = scmd->allowed;
701 else if (rtn != NEEDS_RETRY)
704 scsi_eh_finish_cmd(scmd, done_q);
707 return list_empty(work_q);
711 * scsi_try_to_abort_cmd - Ask host to abort a running command.
712 * @scmd: SCSI cmd to abort from Lower Level.
715 * This function will not return until the user's completion function
716 * has been called. there is no timeout on this operation. if the
717 * author of the low-level driver wishes this operation to be timed,
718 * they can provide this facility themselves. helper functions in
719 * scsi_error.c can be supplied to make this easier to do.
721 static int scsi_try_to_abort_cmd(struct scsi_cmnd *scmd)
723 if (!scmd->device->host->hostt->eh_abort_handler)
727 * scsi_done was called just after the command timed out and before
728 * we had a chance to process it. (db)
730 if (scmd->serial_number == 0)
732 return scmd->device->host->hostt->eh_abort_handler(scmd);
736 * scsi_eh_tur - Send TUR to device.
737 * @scmd: Scsi cmd to send TUR
740 * 0 - Device is ready. 1 - Device NOT ready.
742 static int scsi_eh_tur(struct scsi_cmnd *scmd)
744 static unsigned char tur_command[6] = {TEST_UNIT_READY, 0, 0, 0, 0, 0};
745 int retry_cnt = 1, rtn;
749 memcpy(scmd->cmnd, tur_command, sizeof(tur_command));
752 * zero the sense buffer. the scsi spec mandates that any
753 * untransferred sense data should be interpreted as being zero.
755 memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
757 saved_result = scmd->result;
758 scmd->request_buffer = NULL;
759 scmd->request_bufflen = 0;
761 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
763 scmd->sc_data_direction = DMA_NONE;
765 rtn = scsi_send_eh_cmnd(scmd, SENSE_TIMEOUT);
768 * when we eventually call scsi_finish, we really wish to complete
769 * the original request, so let's restore the original data. (db)
771 scsi_setup_cmd_retry(scmd);
772 scmd->result = saved_result;
775 * hey, we are done. let's look to see what happened.
777 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n",
778 __FUNCTION__, scmd, rtn));
781 else if (rtn == NEEDS_RETRY) {
790 * scsi_eh_abort_cmds - abort canceled commands.
791 * @shost: scsi host being recovered.
792 * @eh_done_q: list_head for processed commands.
795 * Try and see whether or not it makes sense to try and abort the
796 * running command. this only works out to be the case if we have one
797 * command that has timed out. if the command simply failed, it makes
798 * no sense to try and abort the command, since as far as the shost
799 * adapter is concerned, it isn't running.
801 static int scsi_eh_abort_cmds(struct list_head *work_q,
802 struct list_head *done_q)
804 struct scsi_cmnd *scmd, *next;
807 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
808 if (!(scmd->eh_eflags & SCSI_EH_CANCEL_CMD))
810 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting cmd:"
811 "0x%p\n", current->comm,
813 rtn = scsi_try_to_abort_cmd(scmd);
814 if (rtn == SUCCESS) {
815 scmd->eh_eflags &= ~SCSI_EH_CANCEL_CMD;
816 if (!scsi_device_online(scmd->device) ||
817 !scsi_eh_tur(scmd)) {
818 scsi_eh_finish_cmd(scmd, done_q);
822 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting"
829 return list_empty(work_q);
833 * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev
834 * @scmd: SCSI cmd used to send BDR
837 * There is no timeout for this operation. if this operation is
838 * unreliable for a given host, then the host itself needs to put a
839 * timer on it, and set the host back to a consistent state prior to
842 static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd)
846 if (!scmd->device->host->hostt->eh_device_reset_handler)
849 rtn = scmd->device->host->hostt->eh_device_reset_handler(scmd);
850 if (rtn == SUCCESS) {
851 scmd->device->was_reset = 1;
852 scmd->device->expecting_cc_ua = 1;
859 * scsi_eh_try_stu - Send START_UNIT to device.
860 * @scmd: Scsi cmd to send START_UNIT
863 * 0 - Device is ready. 1 - Device NOT ready.
865 static int scsi_eh_try_stu(struct scsi_cmnd *scmd)
867 static unsigned char stu_command[6] = {START_STOP, 0, 0, 0, 1, 0};
871 if (!scmd->device->allow_restart)
874 memcpy(scmd->cmnd, stu_command, sizeof(stu_command));
877 * zero the sense buffer. the scsi spec mandates that any
878 * untransferred sense data should be interpreted as being zero.
880 memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
882 saved_result = scmd->result;
883 scmd->request_buffer = NULL;
884 scmd->request_bufflen = 0;
886 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
888 scmd->sc_data_direction = DMA_NONE;
890 rtn = scsi_send_eh_cmnd(scmd, START_UNIT_TIMEOUT);
893 * when we eventually call scsi_finish, we really wish to complete
894 * the original request, so let's restore the original data. (db)
896 scsi_setup_cmd_retry(scmd);
897 scmd->result = saved_result;
900 * hey, we are done. let's look to see what happened.
902 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n",
903 __FUNCTION__, scmd, rtn));
910 * scsi_eh_stu - send START_UNIT if needed
911 * @shost: scsi host being recovered.
912 * @eh_done_q: list_head for processed commands.
915 * If commands are failing due to not ready, initializing command required,
916 * try revalidating the device, which will end up sending a start unit.
918 static int scsi_eh_stu(struct Scsi_Host *shost,
919 struct list_head *work_q,
920 struct list_head *done_q)
922 struct scsi_cmnd *scmd, *stu_scmd, *next;
923 struct scsi_device *sdev;
925 shost_for_each_device(sdev, shost) {
927 list_for_each_entry(scmd, work_q, eh_entry)
928 if (scmd->device == sdev && SCSI_SENSE_VALID(scmd) &&
929 scsi_check_sense(scmd) == FAILED ) {
937 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending START_UNIT to sdev:"
938 " 0x%p\n", current->comm, sdev));
940 if (!scsi_eh_try_stu(stu_scmd)) {
941 if (!scsi_device_online(sdev) ||
942 !scsi_eh_tur(stu_scmd)) {
943 list_for_each_entry_safe(scmd, next,
945 if (scmd->device == sdev)
946 scsi_eh_finish_cmd(scmd, done_q);
950 SCSI_LOG_ERROR_RECOVERY(3,
951 printk("%s: START_UNIT failed to sdev:"
952 " 0x%p\n", current->comm, sdev));
956 return list_empty(work_q);
961 * scsi_eh_bus_device_reset - send bdr if needed
962 * @shost: scsi host being recovered.
963 * @eh_done_q: list_head for processed commands.
966 * Try a bus device reset. still, look to see whether we have multiple
967 * devices that are jammed or not - if we have multiple devices, it
968 * makes no sense to try bus_device_reset - we really would need to try
969 * a bus_reset instead.
971 static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
972 struct list_head *work_q,
973 struct list_head *done_q)
975 struct scsi_cmnd *scmd, *bdr_scmd, *next;
976 struct scsi_device *sdev;
979 shost_for_each_device(sdev, shost) {
981 list_for_each_entry(scmd, work_q, eh_entry)
982 if (scmd->device == sdev) {
990 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BDR sdev:"
991 " 0x%p\n", current->comm,
993 rtn = scsi_try_bus_device_reset(bdr_scmd);
994 if (rtn == SUCCESS) {
995 if (!scsi_device_online(sdev) ||
996 !scsi_eh_tur(bdr_scmd)) {
997 list_for_each_entry_safe(scmd, next,
999 if (scmd->device == sdev)
1000 scsi_eh_finish_cmd(scmd,
1005 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BDR"
1013 return list_empty(work_q);
1017 * scsi_try_bus_reset - ask host to perform a bus reset
1018 * @scmd: SCSI cmd to send bus reset.
1020 static int scsi_try_bus_reset(struct scsi_cmnd *scmd)
1022 unsigned long flags;
1025 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Bus RST\n",
1028 if (!scmd->device->host->hostt->eh_bus_reset_handler)
1031 rtn = scmd->device->host->hostt->eh_bus_reset_handler(scmd);
1033 if (rtn == SUCCESS) {
1034 if (!scmd->device->host->hostt->skip_settle_delay)
1035 ssleep(BUS_RESET_SETTLE_TIME);
1036 spin_lock_irqsave(scmd->device->host->host_lock, flags);
1037 scsi_report_bus_reset(scmd->device->host, scmd->device->channel);
1038 spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
1045 * scsi_try_host_reset - ask host adapter to reset itself
1046 * @scmd: SCSI cmd to send hsot reset.
1048 static int scsi_try_host_reset(struct scsi_cmnd *scmd)
1050 unsigned long flags;
1053 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Host RST\n",
1056 if (!scmd->device->host->hostt->eh_host_reset_handler)
1059 rtn = scmd->device->host->hostt->eh_host_reset_handler(scmd);
1061 if (rtn == SUCCESS) {
1062 if (!scmd->device->host->hostt->skip_settle_delay)
1063 ssleep(HOST_RESET_SETTLE_TIME);
1064 spin_lock_irqsave(scmd->device->host->host_lock, flags);
1065 scsi_report_bus_reset(scmd->device->host, scmd->device->channel);
1066 spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
1073 * scsi_eh_bus_reset - send a bus reset
1074 * @shost: scsi host being recovered.
1075 * @eh_done_q: list_head for processed commands.
1077 static int scsi_eh_bus_reset(struct Scsi_Host *shost,
1078 struct list_head *work_q,
1079 struct list_head *done_q)
1081 struct scsi_cmnd *scmd, *chan_scmd, *next;
1082 unsigned int channel;
1086 * we really want to loop over the various channels, and do this on
1087 * a channel by channel basis. we should also check to see if any
1088 * of the failed commands are on soft_reset devices, and if so, skip
1092 for (channel = 0; channel <= shost->max_channel; channel++) {
1094 list_for_each_entry(scmd, work_q, eh_entry) {
1095 if (channel == scmd->device->channel) {
1099 * FIXME add back in some support for
1100 * soft_reset devices.
1107 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BRST chan:"
1108 " %d\n", current->comm,
1110 rtn = scsi_try_bus_reset(chan_scmd);
1111 if (rtn == SUCCESS) {
1112 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1113 if (channel == scmd->device->channel)
1114 if (!scsi_device_online(scmd->device) ||
1116 scsi_eh_finish_cmd(scmd,
1120 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BRST"
1121 " failed chan: %d\n",
1126 return list_empty(work_q);
1130 * scsi_eh_host_reset - send a host reset
1131 * @work_q: list_head for processed commands.
1132 * @done_q: list_head for processed commands.
1134 static int scsi_eh_host_reset(struct list_head *work_q,
1135 struct list_head *done_q)
1137 struct scsi_cmnd *scmd, *next;
1140 if (!list_empty(work_q)) {
1141 scmd = list_entry(work_q->next,
1142 struct scsi_cmnd, eh_entry);
1144 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending HRST\n"
1147 rtn = scsi_try_host_reset(scmd);
1148 if (rtn == SUCCESS) {
1149 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1150 if (!scsi_device_online(scmd->device) ||
1151 (!scsi_eh_try_stu(scmd) && !scsi_eh_tur(scmd)) ||
1153 scsi_eh_finish_cmd(scmd, done_q);
1156 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: HRST"
1161 return list_empty(work_q);
1165 * scsi_eh_offline_sdevs - offline scsi devices that fail to recover
1166 * @work_q: list_head for processed commands.
1167 * @done_q: list_head for processed commands.
1170 static void scsi_eh_offline_sdevs(struct list_head *work_q,
1171 struct list_head *done_q)
1173 struct scsi_cmnd *scmd, *next;
1175 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1176 sdev_printk(KERN_INFO, scmd->device,
1177 "scsi: Device offlined - not"
1178 " ready after error recovery\n");
1179 scsi_device_set_state(scmd->device, SDEV_OFFLINE);
1180 if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD) {
1182 * FIXME: Handle lost cmds.
1185 scsi_eh_finish_cmd(scmd, done_q);
1191 * scsi_decide_disposition - Disposition a cmd on return from LLD.
1192 * @scmd: SCSI cmd to examine.
1195 * This is *only* called when we are examining the status after sending
1196 * out the actual data command. any commands that are queued for error
1197 * recovery (e.g. test_unit_ready) do *not* come through here.
1199 * When this routine returns failed, it means the error handler thread
1200 * is woken. In cases where the error code indicates an error that
1201 * doesn't require the error handler read (i.e. we don't need to
1202 * abort/reset), this function should return SUCCESS.
1204 int scsi_decide_disposition(struct scsi_cmnd *scmd)
1209 * if the device is offline, then we clearly just pass the result back
1210 * up to the top level.
1212 if (!scsi_device_online(scmd->device)) {
1213 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: device offline - report"
1220 * first check the host byte, to see if there is anything in there
1221 * that would indicate what we need to do.
1223 switch (host_byte(scmd->result)) {
1224 case DID_PASSTHROUGH:
1226 * no matter what, pass this through to the upper layer.
1227 * nuke this special code so that it looks like we are saying
1230 scmd->result &= 0xff00ffff;
1234 * looks good. drop through, and check the next byte.
1237 case DID_NO_CONNECT:
1238 case DID_BAD_TARGET:
1241 * note - this means that we just report the status back
1242 * to the top level driver, not that we actually think
1243 * that it indicates SUCCESS.
1247 * when the low level driver returns did_soft_error,
1248 * it is responsible for keeping an internal retry counter
1249 * in order to avoid endless loops (db)
1251 * actually this is a bug in this function here. we should
1252 * be mindful of the maximum number of retries specified
1253 * and not get stuck in a loop.
1255 case DID_SOFT_ERROR:
1261 return ADD_TO_MLQUEUE;
1264 if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
1265 status_byte(scmd->result) == RESERVATION_CONFLICT)
1267 * execute reservation conflict processing code
1278 * when we scan the bus, we get timeout messages for
1279 * these commands if there is no device available.
1280 * other hosts report did_no_connect for the same thing.
1282 if ((scmd->cmnd[0] == TEST_UNIT_READY ||
1283 scmd->cmnd[0] == INQUIRY)) {
1295 * next, check the message byte.
1297 if (msg_byte(scmd->result) != COMMAND_COMPLETE)
1301 * check the status byte to see if this indicates anything special.
1303 switch (status_byte(scmd->result)) {
1306 * the case of trying to send too many commands to a
1307 * tagged queueing device.
1311 * device can't talk to us at the moment. Should only
1312 * occur (SAM-3) when the task queue is empty, so will cause
1313 * the empty queue handling to trigger a stall in the
1316 return ADD_TO_MLQUEUE;
1318 case COMMAND_TERMINATED:
1321 case CHECK_CONDITION:
1322 rtn = scsi_check_sense(scmd);
1323 if (rtn == NEEDS_RETRY)
1325 /* if rtn == FAILED, we have no sense information;
1326 * returning FAILED will wake the error handler thread
1327 * to collect the sense and redo the decide
1330 case CONDITION_GOOD:
1331 case INTERMEDIATE_GOOD:
1332 case INTERMEDIATE_C_GOOD:
1335 * who knows? FIXME(eric)
1339 case RESERVATION_CONFLICT:
1340 sdev_printk(KERN_INFO, scmd->device,
1341 "reservation conflict\n");
1342 return SUCCESS; /* causes immediate i/o error */
1350 /* we requeue for retry because the error was retryable, and
1351 * the request was not marked fast fail. Note that above,
1352 * even if the request is marked fast fail, we still requeue
1353 * for queue congestion conditions (QUEUE_FULL or BUSY) */
1354 if ((++scmd->retries) < scmd->allowed
1355 && !blk_noretry_request(scmd->request)) {
1359 * no more retries - report this one back to upper level.
1366 * scsi_eh_lock_done - done function for eh door lock request
1367 * @scmd: SCSI command block for the door lock request
1370 * We completed the asynchronous door lock request, and it has either
1371 * locked the door or failed. We must free the command structures
1372 * associated with this request.
1374 static void scsi_eh_lock_done(struct scsi_cmnd *scmd)
1376 struct scsi_request *sreq = scmd->sc_request;
1378 scsi_release_request(sreq);
1383 * scsi_eh_lock_door - Prevent medium removal for the specified device
1384 * @sdev: SCSI device to prevent medium removal
1387 * We must be called from process context; scsi_allocate_request()
1391 * We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the
1392 * head of the devices request queue, and continue.
1395 * scsi_allocate_request() may sleep waiting for existing requests to
1396 * be processed. However, since we haven't kicked off any request
1397 * processing for this host, this may deadlock.
1399 * If scsi_allocate_request() fails for what ever reason, we
1400 * completely forget to lock the door.
1402 static void scsi_eh_lock_door(struct scsi_device *sdev)
1404 struct scsi_request *sreq = scsi_allocate_request(sdev, GFP_KERNEL);
1406 if (unlikely(!sreq)) {
1407 printk(KERN_ERR "%s: request allocate failed,"
1408 "prevent media removal cmd not sent\n", __FUNCTION__);
1412 sreq->sr_cmnd[0] = ALLOW_MEDIUM_REMOVAL;
1413 sreq->sr_cmnd[1] = 0;
1414 sreq->sr_cmnd[2] = 0;
1415 sreq->sr_cmnd[3] = 0;
1416 sreq->sr_cmnd[4] = SCSI_REMOVAL_PREVENT;
1417 sreq->sr_cmnd[5] = 0;
1418 sreq->sr_data_direction = DMA_NONE;
1419 sreq->sr_bufflen = 0;
1420 sreq->sr_buffer = NULL;
1421 sreq->sr_allowed = 5;
1422 sreq->sr_done = scsi_eh_lock_done;
1423 sreq->sr_timeout_per_command = 10 * HZ;
1424 sreq->sr_cmd_len = COMMAND_SIZE(sreq->sr_cmnd[0]);
1426 scsi_insert_special_req(sreq, 1);
1431 * scsi_restart_operations - restart io operations to the specified host.
1432 * @shost: Host we are restarting.
1435 * When we entered the error handler, we blocked all further i/o to
1436 * this device. we need to 'reverse' this process.
1438 static void scsi_restart_operations(struct Scsi_Host *shost)
1440 struct scsi_device *sdev;
1441 unsigned long flags;
1444 * If the door was locked, we need to insert a door lock request
1445 * onto the head of the SCSI request queue for the device. There
1446 * is no point trying to lock the door of an off-line device.
1448 shost_for_each_device(sdev, shost) {
1449 if (scsi_device_online(sdev) && sdev->locked)
1450 scsi_eh_lock_door(sdev);
1454 * next free up anything directly waiting upon the host. this
1455 * will be requests for character device operations, and also for
1456 * ioctls to queued block devices.
1458 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: waking up host to restart\n",
1461 spin_lock_irqsave(shost->host_lock, flags);
1462 if (scsi_host_set_state(shost, SHOST_RUNNING))
1463 if (scsi_host_set_state(shost, SHOST_CANCEL))
1464 BUG_ON(scsi_host_set_state(shost, SHOST_DEL));
1465 spin_unlock_irqrestore(shost->host_lock, flags);
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;
1588 current->flags |= PF_NOFREEZE;
1592 * Note - we always use TASK_INTERRUPTIBLE even if the module
1593 * was loaded as part of the kernel. The reason is that
1594 * UNINTERRUPTIBLE would cause this thread to be counted in
1595 * the load average as a running process, and an interruptible
1598 set_current_state(TASK_INTERRUPTIBLE);
1599 while (!kthread_should_stop()) {
1600 if (shost->host_failed == 0 ||
1601 shost->host_failed != shost->host_busy) {
1602 SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler"
1607 set_current_state(TASK_INTERRUPTIBLE);
1611 __set_current_state(TASK_RUNNING);
1612 SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler"
1613 " scsi_eh_%d waking"
1614 " up\n",shost->host_no));
1616 shost->eh_active = 1;
1619 * We have a host that is failing for some reason. Figure out
1620 * what we need to do to get it up and online again (if we can).
1621 * If we fail, we end up taking the thing offline.
1623 if (shost->hostt->eh_strategy_handler)
1624 rtn = shost->hostt->eh_strategy_handler(shost);
1626 scsi_unjam_host(shost);
1628 shost->eh_active = 0;
1631 * Note - if the above fails completely, the action is to take
1632 * individual devices offline and flush the queue of any
1633 * outstanding requests that may have been pending. When we
1634 * restart, we restart any I/O to any other devices on the bus
1635 * which are still online.
1637 scsi_restart_operations(shost);
1638 set_current_state(TASK_INTERRUPTIBLE);
1641 __set_current_state(TASK_RUNNING);
1643 SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler scsi_eh_%d"
1644 " exiting\n",shost->host_no));
1647 * Make sure that nobody tries to wake us up again.
1649 shost->ehandler = NULL;
1654 * Function: scsi_report_bus_reset()
1656 * Purpose: Utility function used by low-level drivers to report that
1657 * they have observed a bus reset on the bus being handled.
1659 * Arguments: shost - Host in question
1660 * channel - channel on which reset was observed.
1664 * Lock status: Host lock must be held.
1666 * Notes: This only needs to be called if the reset is one which
1667 * originates from an unknown location. Resets originated
1668 * by the mid-level itself don't need to call this, but there
1669 * should be no harm.
1671 * The main purpose of this is to make sure that a CHECK_CONDITION
1672 * is properly treated.
1674 void scsi_report_bus_reset(struct Scsi_Host *shost, int channel)
1676 struct scsi_device *sdev;
1678 __shost_for_each_device(sdev, shost) {
1679 if (channel == sdev->channel) {
1680 sdev->was_reset = 1;
1681 sdev->expecting_cc_ua = 1;
1685 EXPORT_SYMBOL(scsi_report_bus_reset);
1688 * Function: scsi_report_device_reset()
1690 * Purpose: Utility function used by low-level drivers to report that
1691 * they have observed a device reset on the device being handled.
1693 * Arguments: shost - Host in question
1694 * channel - channel on which reset was observed
1695 * target - target on which reset was observed
1699 * Lock status: Host lock must be held
1701 * Notes: This only needs to be called if the reset is one which
1702 * originates from an unknown location. Resets originated
1703 * by the mid-level itself don't need to call this, but there
1704 * should be no harm.
1706 * The main purpose of this is to make sure that a CHECK_CONDITION
1707 * is properly treated.
1709 void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
1711 struct scsi_device *sdev;
1713 __shost_for_each_device(sdev, shost) {
1714 if (channel == sdev->channel &&
1715 target == sdev->id) {
1716 sdev->was_reset = 1;
1717 sdev->expecting_cc_ua = 1;
1721 EXPORT_SYMBOL(scsi_report_device_reset);
1724 scsi_reset_provider_done_command(struct scsi_cmnd *scmd)
1729 * Function: scsi_reset_provider
1731 * Purpose: Send requested reset to a bus or device at any phase.
1733 * Arguments: device - device to send reset to
1734 * flag - reset type (see scsi.h)
1736 * Returns: SUCCESS/FAILURE.
1738 * Notes: This is used by the SCSI Generic driver to provide
1739 * Bus/Device reset capability.
1742 scsi_reset_provider(struct scsi_device *dev, int flag)
1744 struct scsi_cmnd *scmd = scsi_get_command(dev, GFP_KERNEL);
1748 scmd->request = &req;
1749 memset(&scmd->eh_timeout, 0, sizeof(scmd->eh_timeout));
1750 scmd->request->rq_status = RQ_SCSI_BUSY;
1752 memset(&scmd->cmnd, '\0', sizeof(scmd->cmnd));
1754 scmd->scsi_done = scsi_reset_provider_done_command;
1756 scmd->buffer = NULL;
1758 scmd->request_buffer = NULL;
1759 scmd->request_bufflen = 0;
1763 scmd->sc_data_direction = DMA_BIDIRECTIONAL;
1764 scmd->sc_request = NULL;
1765 scmd->sc_magic = SCSI_CMND_MAGIC;
1767 init_timer(&scmd->eh_timeout);
1770 * Sometimes the command can get back into the timer chain,
1771 * so use the pid as an identifier.
1776 case SCSI_TRY_RESET_DEVICE:
1777 rtn = scsi_try_bus_device_reset(scmd);
1781 case SCSI_TRY_RESET_BUS:
1782 rtn = scsi_try_bus_reset(scmd);
1786 case SCSI_TRY_RESET_HOST:
1787 rtn = scsi_try_host_reset(scmd);
1793 scsi_next_command(scmd);
1796 EXPORT_SYMBOL(scsi_reset_provider);
1799 * scsi_normalize_sense - normalize main elements from either fixed or
1800 * descriptor sense data format into a common format.
1802 * @sense_buffer: byte array containing sense data returned by device
1803 * @sb_len: number of valid bytes in sense_buffer
1804 * @sshdr: pointer to instance of structure that common
1805 * elements are written to.
1808 * The "main elements" from sense data are: response_code, sense_key,
1809 * asc, ascq and additional_length (only for descriptor format).
1811 * Typically this function can be called after a device has
1812 * responded to a SCSI command with the CHECK_CONDITION status.
1815 * 1 if valid sense data information found, else 0;
1817 int scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
1818 struct scsi_sense_hdr *sshdr)
1820 if (!sense_buffer || !sb_len)
1823 memset(sshdr, 0, sizeof(struct scsi_sense_hdr));
1825 sshdr->response_code = (sense_buffer[0] & 0x7f);
1827 if (!scsi_sense_valid(sshdr))
1830 if (sshdr->response_code >= 0x72) {
1835 sshdr->sense_key = (sense_buffer[1] & 0xf);
1837 sshdr->asc = sense_buffer[2];
1839 sshdr->ascq = sense_buffer[3];
1841 sshdr->additional_length = sense_buffer[7];
1847 sshdr->sense_key = (sense_buffer[2] & 0xf);
1849 sb_len = (sb_len < (sense_buffer[7] + 8)) ?
1850 sb_len : (sense_buffer[7] + 8);
1852 sshdr->asc = sense_buffer[12];
1854 sshdr->ascq = sense_buffer[13];
1860 EXPORT_SYMBOL(scsi_normalize_sense);
1862 int scsi_request_normalize_sense(struct scsi_request *sreq,
1863 struct scsi_sense_hdr *sshdr)
1865 return scsi_normalize_sense(sreq->sr_sense_buffer,
1866 sizeof(sreq->sr_sense_buffer), sshdr);
1868 EXPORT_SYMBOL(scsi_request_normalize_sense);
1870 int scsi_command_normalize_sense(struct scsi_cmnd *cmd,
1871 struct scsi_sense_hdr *sshdr)
1873 return scsi_normalize_sense(cmd->sense_buffer,
1874 sizeof(cmd->sense_buffer), sshdr);
1876 EXPORT_SYMBOL(scsi_command_normalize_sense);
1879 * scsi_sense_desc_find - search for a given descriptor type in
1880 * descriptor sense data format.
1882 * @sense_buffer: byte array of descriptor format sense data
1883 * @sb_len: number of valid bytes in sense_buffer
1884 * @desc_type: value of descriptor type to find
1885 * (e.g. 0 -> information)
1888 * only valid when sense data is in descriptor format
1891 * pointer to start of (first) descriptor if found else NULL
1893 const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
1896 int add_sen_len, add_len, desc_len, k;
1899 if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7])))
1901 if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73))
1903 add_sen_len = (add_sen_len < (sb_len - 8)) ?
1904 add_sen_len : (sb_len - 8);
1905 descp = &sense_buffer[8];
1906 for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) {
1908 add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
1909 desc_len = add_len + 2;
1910 if (descp[0] == desc_type)
1912 if (add_len < 0) // short descriptor ??
1917 EXPORT_SYMBOL(scsi_sense_desc_find);
1920 * scsi_get_sense_info_fld - attempts to get information field from
1921 * sense data (either fixed or descriptor format)
1923 * @sense_buffer: byte array of sense data
1924 * @sb_len: number of valid bytes in sense_buffer
1925 * @info_out: pointer to 64 integer where 8 or 4 byte information
1926 * field will be placed if found.
1929 * 1 if information field found, 0 if not found.
1931 int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len,
1940 switch (sense_buffer[0] & 0x7f) {
1943 if (sense_buffer[0] & 0x80) {
1944 *info_out = (sense_buffer[3] << 24) +
1945 (sense_buffer[4] << 16) +
1946 (sense_buffer[5] << 8) + sense_buffer[6];
1952 ucp = scsi_sense_desc_find(sense_buffer, sb_len,
1954 if (ucp && (0xa == ucp[1])) {
1956 for (j = 0; j < 8; ++j) {
1969 EXPORT_SYMBOL(scsi_get_sense_info_fld);