2 * scsi_error.c Copyright (C) 1997 Eric Youngdale
4 * SCSI error/timeout handling
5 * Initial versions: Eric Youngdale. Based upon conversations with
6 * Leonard Zubkoff and David Miller at Linux Expo,
7 * ideas originating from all over the place.
9 * Restructured scsi_unjam_host and associated functions.
10 * September 04, 2002 Mike Anderson (andmike@us.ibm.com)
12 * Forward port of Russell King's (rmk@arm.linux.org.uk) changes and
14 * September 30, 2002 Mike Anderson (andmike@us.ibm.com)
17 #include <linux/module.h>
18 #include <linux/sched.h>
19 #include <linux/timer.h>
20 #include <linux/string.h>
21 #include <linux/slab.h>
22 #include <linux/kernel.h>
23 #include <linux/interrupt.h>
24 #include <linux/blkdev.h>
25 #include <linux/delay.h>
27 #include <scsi/scsi.h>
28 #include <scsi/scsi_dbg.h>
29 #include <scsi/scsi_device.h>
30 #include <scsi/scsi_eh.h>
31 #include <scsi/scsi_host.h>
32 #include <scsi/scsi_ioctl.h>
33 #include <scsi/scsi_request.h>
35 #include "scsi_priv.h"
36 #include "scsi_logging.h"
38 #define SENSE_TIMEOUT (10*HZ)
39 #define START_UNIT_TIMEOUT (30*HZ)
42 * These should *probably* be handled by the host itself.
43 * Since it is allowed to sleep, it probably should.
45 #define BUS_RESET_SETTLE_TIME (10)
46 #define HOST_RESET_SETTLE_TIME (10)
48 /* called with shost->host_lock held */
49 void scsi_eh_wakeup(struct Scsi_Host *shost)
51 if (shost->host_busy == shost->host_failed) {
53 SCSI_LOG_ERROR_RECOVERY(5,
54 printk("Waking error handler thread\n"));
59 * scsi_eh_scmd_add - add scsi cmd to error handling.
60 * @scmd: scmd to run eh on.
61 * @eh_flag: optional SCSI_EH flag.
66 int scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag)
68 struct Scsi_Host *shost = scmd->device->host;
71 if (shost->eh_wait == NULL)
74 spin_lock_irqsave(shost->host_lock, flags);
76 scsi_eh_eflags_set(scmd, eh_flag);
78 * FIXME: Can we stop setting owner and state.
80 scmd->owner = SCSI_OWNER_ERROR_HANDLER;
81 scmd->state = SCSI_STATE_FAILED;
82 list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q);
83 set_bit(SHOST_RECOVERY, &shost->shost_state);
85 scsi_eh_wakeup(shost);
86 spin_unlock_irqrestore(shost->host_lock, flags);
91 * scsi_add_timer - Start timeout timer for a single scsi command.
92 * @scmd: scsi command that is about to start running.
93 * @timeout: amount of time to allow this command to run.
94 * @complete: timeout function to call if timer isn't canceled.
97 * This should be turned into an inline function. Each scsi command
98 * has its own timer, and as it is added to the queue, we set up the
99 * timer. When the command completes, we cancel the timer.
101 void scsi_add_timer(struct scsi_cmnd *scmd, int timeout,
102 void (*complete)(struct scsi_cmnd *))
106 * If the clock was already running for this command, then
107 * first delete the timer. The timer handling code gets rather
108 * confused if we don't do this.
110 if (scmd->eh_timeout.function)
111 del_timer(&scmd->eh_timeout);
113 scmd->eh_timeout.data = (unsigned long)scmd;
114 scmd->eh_timeout.expires = jiffies + timeout;
115 scmd->eh_timeout.function = (void (*)(unsigned long)) complete;
117 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p, time:"
118 " %d, (%p)\n", __FUNCTION__,
119 scmd, timeout, complete));
121 add_timer(&scmd->eh_timeout);
123 EXPORT_SYMBOL(scsi_add_timer);
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;
151 EXPORT_SYMBOL(scsi_delete_timer);
154 * scsi_times_out - Timeout function for normal scsi commands.
155 * @scmd: Cmd that is timing out.
158 * We do not need to lock this. There is the potential for a race
159 * only in that the normal completion handling might run, but if the
160 * normal completion function determines that the timer has already
161 * fired, then it mustn't do anything.
163 void scsi_times_out(struct scsi_cmnd *scmd)
165 scsi_log_completion(scmd, TIMEOUT_ERROR);
167 if (scmd->device->host->hostt->eh_timed_out)
168 switch (scmd->device->host->hostt->eh_timed_out(scmd)) {
173 /* This allows a single retry even of a command
174 * with allowed == 0 */
175 if (scmd->retries++ > scmd->allowed)
177 scsi_add_timer(scmd, scmd->timeout_per_command,
184 if (unlikely(!scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD))) {
185 panic("Error handler thread not present at %p %p %s %d",
186 scmd, scmd->device->host, __FILE__, __LINE__);
191 * scsi_block_when_processing_errors - Prevent cmds from being queued.
192 * @sdev: Device on which we are performing recovery.
195 * We block until the host is out of error recovery, and then check to
196 * see whether the host or the device is offline.
199 * 0 when dev was taken offline by error recovery. 1 OK to proceed.
201 int scsi_block_when_processing_errors(struct scsi_device *sdev)
205 wait_event(sdev->host->host_wait, (!test_bit(SHOST_RECOVERY, &sdev->host->shost_state)));
207 online = scsi_device_online(sdev);
209 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: rtn: %d\n", __FUNCTION__,
214 EXPORT_SYMBOL(scsi_block_when_processing_errors);
216 #ifdef CONFIG_SCSI_LOGGING
218 * scsi_eh_prt_fail_stats - Log info on failures.
219 * @shost: scsi host being recovered.
220 * @work_q: Queue of scsi cmds to process.
222 static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost,
223 struct list_head *work_q)
225 struct scsi_cmnd *scmd;
226 struct scsi_device *sdev;
227 int total_failures = 0;
230 int devices_failed = 0;
232 shost_for_each_device(sdev, shost) {
233 list_for_each_entry(scmd, work_q, eh_entry) {
234 if (scmd->device == sdev) {
236 if (scsi_eh_eflags_chk(scmd,
244 if (cmd_cancel || cmd_failed) {
245 SCSI_LOG_ERROR_RECOVERY(3,
246 printk("%s: %d:%d:%d:%d cmds failed: %d,"
248 __FUNCTION__, shost->host_no,
249 sdev->channel, sdev->id, sdev->lun,
250 cmd_failed, cmd_cancel));
257 SCSI_LOG_ERROR_RECOVERY(2, printk("Total of %d commands on %d"
258 " devices require eh work\n",
259 total_failures, devices_failed));
264 * scsi_check_sense - Examine scsi cmd sense
265 * @scmd: Cmd to have sense checked.
268 * SUCCESS or FAILED or NEEDS_RETRY
271 * When a deferred error is detected the current command has
272 * not been executed and needs retrying.
274 static int scsi_check_sense(struct scsi_cmnd *scmd)
276 struct scsi_sense_hdr sshdr;
278 if (! scsi_command_normalize_sense(scmd, &sshdr))
279 return FAILED; /* no valid sense data */
281 if (scsi_sense_is_deferred(&sshdr))
285 * Previous logic looked for FILEMARK, EOM or ILI which are
286 * mainly associated with tapes and returned SUCCESS.
288 if (sshdr.response_code == 0x70) {
290 if (scmd->sense_buffer[2] & 0xe0)
294 * descriptor format: look for "stream commands sense data
295 * descriptor" (see SSC-3). Assume single sense data
296 * descriptor. Ignore ILI from SBC-2 READ LONG and WRITE LONG.
298 if ((sshdr.additional_length > 3) &&
299 (scmd->sense_buffer[8] == 0x4) &&
300 (scmd->sense_buffer[11] & 0xe0))
304 switch (sshdr.sense_key) {
307 case RECOVERED_ERROR:
308 return /* soft_error */ SUCCESS;
310 case ABORTED_COMMAND:
315 * if we are expecting a cc/ua because of a bus reset that we
316 * performed, treat this just as a retry. otherwise this is
317 * information that we should pass up to the upper-level driver
318 * so that we can deal with it there.
320 if (scmd->device->expecting_cc_ua) {
321 scmd->device->expecting_cc_ua = 0;
325 * if the device is in the process of becoming ready, we
328 if ((sshdr.asc == 0x04) && (sshdr.ascq == 0x01))
331 * if the device is not started, we need to wake
332 * the error handler to start the motor
334 if (scmd->device->allow_restart &&
335 (sshdr.asc == 0x04) && (sshdr.ascq == 0x02))
339 /* these three are not supported */
341 case VOLUME_OVERFLOW:
349 if (scmd->device->retry_hwerror)
354 case ILLEGAL_REQUEST:
363 * scsi_eh_completed_normally - Disposition a eh cmd on return from LLD.
364 * @scmd: SCSI cmd to examine.
367 * This is *only* called when we are examining the status of commands
368 * queued during error recovery. the main difference here is that we
369 * don't allow for the possibility of retries here, and we are a lot
370 * more restrictive about what we consider acceptable.
372 static int scsi_eh_completed_normally(struct scsi_cmnd *scmd)
375 * first check the host byte, to see if there is anything in there
376 * that would indicate what we need to do.
378 if (host_byte(scmd->result) == DID_RESET) {
380 * rats. we are already in the error handler, so we now
381 * get to try and figure out what to do next. if the sense
382 * is valid, we have a pretty good idea of what to do.
383 * if not, we mark it as FAILED.
385 return scsi_check_sense(scmd);
387 if (host_byte(scmd->result) != DID_OK)
391 * next, check the message byte.
393 if (msg_byte(scmd->result) != COMMAND_COMPLETE)
397 * now, check the status byte to see if this indicates
400 switch (status_byte(scmd->result)) {
402 case COMMAND_TERMINATED:
404 case CHECK_CONDITION:
405 return scsi_check_sense(scmd);
407 case INTERMEDIATE_GOOD:
408 case INTERMEDIATE_C_GOOD:
410 * who knows? FIXME(eric)
415 case RESERVATION_CONFLICT:
423 * scsi_eh_times_out - timeout function for error handling.
424 * @scmd: Cmd that is timing out.
427 * During error handling, the kernel thread will be sleeping waiting
428 * for some action to complete on the device. our only job is to
429 * record that it timed out, and to wake up the thread.
431 static void scsi_eh_times_out(struct scsi_cmnd *scmd)
433 scsi_eh_eflags_set(scmd, SCSI_EH_REC_TIMEOUT);
434 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd:%p\n", __FUNCTION__,
437 up(scmd->device->host->eh_action);
441 * scsi_eh_done - Completion function for error handling.
442 * @scmd: Cmd that is done.
444 static void scsi_eh_done(struct scsi_cmnd *scmd)
447 * if the timeout handler is already running, then just set the
448 * flag which says we finished late, and return. we have no
449 * way of stopping the timeout handler from running, so we must
450 * always defer to it.
452 if (del_timer(&scmd->eh_timeout)) {
453 scmd->request->rq_status = RQ_SCSI_DONE;
454 scmd->owner = SCSI_OWNER_ERROR_HANDLER;
456 SCSI_LOG_ERROR_RECOVERY(3, printk("%s scmd: %p result: %x\n",
457 __FUNCTION__, scmd, scmd->result));
459 up(scmd->device->host->eh_action);
464 * scsi_send_eh_cmnd - send a cmd to a device as part of error recovery.
465 * @scmd: SCSI Cmd to send.
466 * @timeout: Timeout for cmd.
469 * The initialization of the structures is quite a bit different in
470 * this case, and furthermore, there is a different completion handler
471 * vs scsi_dispatch_cmd.
473 * SUCCESS or FAILED or NEEDS_RETRY
475 static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, int timeout)
477 struct scsi_device *sdev = scmd->device;
478 struct Scsi_Host *shost = sdev->host;
479 DECLARE_MUTEX_LOCKED(sem);
484 * we will use a queued command if possible, otherwise we will
485 * emulate the queuing and calling of completion function ourselves.
487 scmd->owner = SCSI_OWNER_LOWLEVEL;
489 if (sdev->scsi_level <= SCSI_2)
490 scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) |
491 (sdev->lun << 5 & 0xe0);
493 scsi_add_timer(scmd, timeout, scsi_eh_times_out);
496 * set up the semaphore so we wait for the command to complete.
498 shost->eh_action = &sem;
499 scmd->request->rq_status = RQ_SCSI_BUSY;
501 spin_lock_irqsave(shost->host_lock, flags);
503 shost->hostt->queuecommand(scmd, scsi_eh_done);
504 spin_unlock_irqrestore(shost->host_lock, flags);
507 scsi_log_completion(scmd, SUCCESS);
509 shost->eh_action = NULL;
512 * see if timeout. if so, tell the host to forget about it.
513 * in other words, we don't want a callback any more.
515 if (scsi_eh_eflags_chk(scmd, SCSI_EH_REC_TIMEOUT)) {
516 scsi_eh_eflags_clr(scmd, SCSI_EH_REC_TIMEOUT);
517 scmd->owner = SCSI_OWNER_LOWLEVEL;
520 * as far as the low level driver is
521 * concerned, this command is still active, so
522 * we must give the low level driver a chance
525 * FIXME(eric) - we are not tracking whether we could
526 * abort a timed out command or not. not sure how
527 * we should treat them differently anyways.
529 if (shost->hostt->eh_abort_handler)
530 shost->hostt->eh_abort_handler(scmd);
532 scmd->request->rq_status = RQ_SCSI_DONE;
533 scmd->owner = SCSI_OWNER_ERROR_HANDLER;
538 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd: %p, rtn:%x\n",
539 __FUNCTION__, scmd, rtn));
542 * now examine the actual status codes to see whether the command
543 * actually did complete normally.
545 if (rtn == SUCCESS) {
546 rtn = scsi_eh_completed_normally(scmd);
547 SCSI_LOG_ERROR_RECOVERY(3,
548 printk("%s: scsi_eh_completed_normally %x\n",
565 * scsi_request_sense - Request sense data from a particular target.
566 * @scmd: SCSI cmd for request sense.
569 * Some hosts automatically obtain this information, others require
570 * that we obtain it on our own. This function will *not* return until
571 * the command either times out, or it completes.
573 static int scsi_request_sense(struct scsi_cmnd *scmd)
575 static unsigned char generic_sense[6] =
576 {REQUEST_SENSE, 0, 0, 0, 252, 0};
577 unsigned char *scsi_result;
581 memcpy(scmd->cmnd, generic_sense, sizeof(generic_sense));
583 scsi_result = kmalloc(252, GFP_ATOMIC | ((scmd->device->host->hostt->unchecked_isa_dma) ? __GFP_DMA : 0));
586 if (unlikely(!scsi_result)) {
587 printk(KERN_ERR "%s: cannot allocate scsi_result.\n",
593 * zero the sense buffer. some host adapters automatically always
594 * request sense, so it is not a good idea that
595 * scmd->request_buffer and scmd->sense_buffer point to the same
596 * address (db). 0 is not a valid sense code.
598 memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
599 memset(scsi_result, 0, 252);
601 saved_result = scmd->result;
602 scmd->request_buffer = scsi_result;
603 scmd->request_bufflen = 252;
605 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
606 scmd->sc_data_direction = DMA_FROM_DEVICE;
609 rtn = scsi_send_eh_cmnd(scmd, SENSE_TIMEOUT);
611 /* last chance to have valid sense data */
612 if(!SCSI_SENSE_VALID(scmd)) {
613 memcpy(scmd->sense_buffer, scmd->request_buffer,
614 sizeof(scmd->sense_buffer));
620 * when we eventually call scsi_finish, we really wish to complete
621 * the original request, so let's restore the original data. (db)
623 scsi_setup_cmd_retry(scmd);
624 scmd->result = saved_result;
629 * scsi_eh_finish_cmd - Handle a cmd that eh is finished with.
630 * @scmd: Original SCSI cmd that eh has finished.
631 * @done_q: Queue for processed commands.
634 * We don't want to use the normal command completion while we are are
635 * still handling errors - it may cause other commands to be queued,
636 * and that would disturb what we are doing. thus we really want to
637 * keep a list of pending commands for final completion, and once we
638 * are ready to leave error handling we handle completion for real.
640 static void scsi_eh_finish_cmd(struct scsi_cmnd *scmd,
641 struct list_head *done_q)
643 scmd->device->host->host_failed--;
644 scmd->state = SCSI_STATE_BHQUEUE;
646 scsi_eh_eflags_clr_all(scmd);
649 * set this back so that the upper level can correctly free up
652 scsi_setup_cmd_retry(scmd);
653 list_move_tail(&scmd->eh_entry, done_q);
657 * scsi_eh_get_sense - Get device sense data.
658 * @work_q: Queue of commands to process.
659 * @done_q: Queue of proccessed commands..
662 * See if we need to request sense information. if so, then get it
663 * now, so we have a better idea of what to do.
666 * This has the unfortunate side effect that if a shost adapter does
667 * not automatically request sense information, that we end up shutting
668 * it down before we request it.
670 * All drivers should request sense information internally these days,
671 * so for now all I have to say is tough noogies if you end up in here.
673 * XXX: Long term this code should go away, but that needs an audit of
676 static int scsi_eh_get_sense(struct list_head *work_q,
677 struct list_head *done_q)
679 struct list_head *lh, *lh_sf;
680 struct scsi_cmnd *scmd;
683 list_for_each_safe(lh, lh_sf, work_q) {
684 scmd = list_entry(lh, struct scsi_cmnd, eh_entry);
685 if (scsi_eh_eflags_chk(scmd, SCSI_EH_CANCEL_CMD) ||
686 SCSI_SENSE_VALID(scmd))
689 SCSI_LOG_ERROR_RECOVERY(2, printk("%s: requesting sense"
693 rtn = scsi_request_sense(scmd);
697 SCSI_LOG_ERROR_RECOVERY(3, printk("sense requested for %p"
698 " result %x\n", scmd,
700 SCSI_LOG_ERROR_RECOVERY(3, scsi_print_sense("bh", scmd));
702 rtn = scsi_decide_disposition(scmd);
705 * if the result was normal, then just pass it along to the
709 /* we don't want this command reissued, just
710 * finished with the sense data, so set
711 * retries to the max allowed to ensure it
712 * won't get reissued */
713 scmd->retries = scmd->allowed;
714 else if (rtn != NEEDS_RETRY)
717 scsi_eh_finish_cmd(scmd, done_q);
720 return list_empty(work_q);
724 * scsi_try_to_abort_cmd - Ask host to abort a running command.
725 * @scmd: SCSI cmd to abort from Lower Level.
728 * This function will not return until the user's completion function
729 * has been called. there is no timeout on this operation. if the
730 * author of the low-level driver wishes this operation to be timed,
731 * they can provide this facility themselves. helper functions in
732 * scsi_error.c can be supplied to make this easier to do.
734 static int scsi_try_to_abort_cmd(struct scsi_cmnd *scmd)
736 if (!scmd->device->host->hostt->eh_abort_handler)
740 * scsi_done was called just after the command timed out and before
741 * we had a chance to process it. (db)
743 if (scmd->serial_number == 0)
746 scmd->owner = SCSI_OWNER_LOWLEVEL;
748 return scmd->device->host->hostt->eh_abort_handler(scmd);
752 * scsi_eh_tur - Send TUR to device.
753 * @scmd: Scsi cmd to send TUR
756 * 0 - Device is ready. 1 - Device NOT ready.
758 static int scsi_eh_tur(struct scsi_cmnd *scmd)
760 static unsigned char tur_command[6] = {TEST_UNIT_READY, 0, 0, 0, 0, 0};
761 int retry_cnt = 1, rtn;
765 memcpy(scmd->cmnd, tur_command, sizeof(tur_command));
768 * zero the sense buffer. the scsi spec mandates that any
769 * untransferred sense data should be interpreted as being zero.
771 memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
773 saved_result = scmd->result;
774 scmd->request_buffer = NULL;
775 scmd->request_bufflen = 0;
777 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
779 scmd->sc_data_direction = DMA_NONE;
781 rtn = scsi_send_eh_cmnd(scmd, SENSE_TIMEOUT);
784 * when we eventually call scsi_finish, we really wish to complete
785 * the original request, so let's restore the original data. (db)
787 scsi_setup_cmd_retry(scmd);
788 scmd->result = saved_result;
791 * hey, we are done. let's look to see what happened.
793 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n",
794 __FUNCTION__, scmd, rtn));
797 else if (rtn == NEEDS_RETRY)
804 * scsi_eh_abort_cmds - abort canceled commands.
805 * @shost: scsi host being recovered.
806 * @eh_done_q: list_head for processed commands.
809 * Try and see whether or not it makes sense to try and abort the
810 * running command. this only works out to be the case if we have one
811 * command that has timed out. if the command simply failed, it makes
812 * no sense to try and abort the command, since as far as the shost
813 * adapter is concerned, it isn't running.
815 static int scsi_eh_abort_cmds(struct list_head *work_q,
816 struct list_head *done_q)
818 struct list_head *lh, *lh_sf;
819 struct scsi_cmnd *scmd;
822 list_for_each_safe(lh, lh_sf, work_q) {
823 scmd = list_entry(lh, struct scsi_cmnd, eh_entry);
824 if (!scsi_eh_eflags_chk(scmd, SCSI_EH_CANCEL_CMD))
826 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting cmd:"
827 "0x%p\n", current->comm,
829 rtn = scsi_try_to_abort_cmd(scmd);
830 if (rtn == SUCCESS) {
831 scsi_eh_eflags_clr(scmd, SCSI_EH_CANCEL_CMD);
832 if (!scsi_device_online(scmd->device) ||
833 !scsi_eh_tur(scmd)) {
834 scsi_eh_finish_cmd(scmd, done_q);
838 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting"
845 return list_empty(work_q);
849 * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev
850 * @scmd: SCSI cmd used to send BDR
853 * There is no timeout for this operation. if this operation is
854 * unreliable for a given host, then the host itself needs to put a
855 * timer on it, and set the host back to a consistent state prior to
858 static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd)
863 if (!scmd->device->host->hostt->eh_device_reset_handler)
866 scmd->owner = SCSI_OWNER_LOWLEVEL;
868 spin_lock_irqsave(scmd->device->host->host_lock, flags);
869 rtn = scmd->device->host->hostt->eh_device_reset_handler(scmd);
870 spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
872 if (rtn == SUCCESS) {
873 scmd->device->was_reset = 1;
874 scmd->device->expecting_cc_ua = 1;
881 * scsi_eh_try_stu - Send START_UNIT to device.
882 * @scmd: Scsi cmd to send START_UNIT
885 * 0 - Device is ready. 1 - Device NOT ready.
887 static int scsi_eh_try_stu(struct scsi_cmnd *scmd)
889 static unsigned char stu_command[6] = {START_STOP, 0, 0, 0, 1, 0};
893 if (!scmd->device->allow_restart)
896 memcpy(scmd->cmnd, stu_command, sizeof(stu_command));
899 * zero the sense buffer. the scsi spec mandates that any
900 * untransferred sense data should be interpreted as being zero.
902 memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
904 saved_result = scmd->result;
905 scmd->request_buffer = NULL;
906 scmd->request_bufflen = 0;
908 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
910 scmd->sc_data_direction = DMA_NONE;
912 rtn = scsi_send_eh_cmnd(scmd, START_UNIT_TIMEOUT);
915 * when we eventually call scsi_finish, we really wish to complete
916 * the original request, so let's restore the original data. (db)
918 scsi_setup_cmd_retry(scmd);
919 scmd->result = saved_result;
922 * hey, we are done. let's look to see what happened.
924 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n",
925 __FUNCTION__, scmd, rtn));
932 * scsi_eh_stu - send START_UNIT if needed
933 * @shost: scsi host being recovered.
934 * @eh_done_q: list_head for processed commands.
937 * If commands are failing due to not ready, initializing command required,
938 * try revalidating the device, which will end up sending a start unit.
940 static int scsi_eh_stu(struct Scsi_Host *shost,
941 struct list_head *work_q,
942 struct list_head *done_q)
944 struct list_head *lh, *lh_sf;
945 struct scsi_cmnd *scmd, *stu_scmd;
946 struct scsi_device *sdev;
948 shost_for_each_device(sdev, shost) {
950 list_for_each_entry(scmd, work_q, eh_entry)
951 if (scmd->device == sdev && SCSI_SENSE_VALID(scmd) &&
952 scsi_check_sense(scmd) == FAILED ) {
960 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending START_UNIT to sdev:"
961 " 0x%p\n", current->comm, sdev));
963 if (!scsi_eh_try_stu(stu_scmd)) {
964 if (!scsi_device_online(sdev) ||
965 !scsi_eh_tur(stu_scmd)) {
966 list_for_each_safe(lh, lh_sf, work_q) {
967 scmd = list_entry(lh, struct scsi_cmnd, eh_entry);
968 if (scmd->device == sdev)
969 scsi_eh_finish_cmd(scmd, done_q);
973 SCSI_LOG_ERROR_RECOVERY(3,
974 printk("%s: START_UNIT failed to sdev:"
975 " 0x%p\n", current->comm, sdev));
979 return list_empty(work_q);
984 * scsi_eh_bus_device_reset - send bdr if needed
985 * @shost: scsi host being recovered.
986 * @eh_done_q: list_head for processed commands.
989 * Try a bus device reset. still, look to see whether we have multiple
990 * devices that are jammed or not - if we have multiple devices, it
991 * makes no sense to try bus_device_reset - we really would need to try
992 * a bus_reset instead.
994 static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
995 struct list_head *work_q,
996 struct list_head *done_q)
998 struct list_head *lh, *lh_sf;
999 struct scsi_cmnd *scmd, *bdr_scmd;
1000 struct scsi_device *sdev;
1003 shost_for_each_device(sdev, shost) {
1005 list_for_each_entry(scmd, work_q, eh_entry)
1006 if (scmd->device == sdev) {
1014 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BDR sdev:"
1015 " 0x%p\n", current->comm,
1017 rtn = scsi_try_bus_device_reset(bdr_scmd);
1018 if (rtn == SUCCESS) {
1019 if (!scsi_device_online(sdev) ||
1020 !scsi_eh_tur(bdr_scmd)) {
1021 list_for_each_safe(lh, lh_sf,
1023 scmd = list_entry(lh, struct
1026 if (scmd->device == sdev)
1027 scsi_eh_finish_cmd(scmd,
1032 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BDR"
1040 return list_empty(work_q);
1044 * scsi_try_bus_reset - ask host to perform a bus reset
1045 * @scmd: SCSI cmd to send bus reset.
1047 static int scsi_try_bus_reset(struct scsi_cmnd *scmd)
1049 unsigned long flags;
1052 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Bus RST\n",
1054 scmd->owner = SCSI_OWNER_LOWLEVEL;
1056 if (!scmd->device->host->hostt->eh_bus_reset_handler)
1059 spin_lock_irqsave(scmd->device->host->host_lock, flags);
1060 rtn = scmd->device->host->hostt->eh_bus_reset_handler(scmd);
1061 spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
1063 if (rtn == SUCCESS) {
1064 if (!scmd->device->host->hostt->skip_settle_delay)
1065 ssleep(BUS_RESET_SETTLE_TIME);
1066 spin_lock_irqsave(scmd->device->host->host_lock, flags);
1067 scsi_report_bus_reset(scmd->device->host, scmd->device->channel);
1068 spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
1075 * scsi_try_host_reset - ask host adapter to reset itself
1076 * @scmd: SCSI cmd to send hsot reset.
1078 static int scsi_try_host_reset(struct scsi_cmnd *scmd)
1080 unsigned long flags;
1083 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Host RST\n",
1085 scmd->owner = SCSI_OWNER_LOWLEVEL;
1087 if (!scmd->device->host->hostt->eh_host_reset_handler)
1090 spin_lock_irqsave(scmd->device->host->host_lock, flags);
1091 rtn = scmd->device->host->hostt->eh_host_reset_handler(scmd);
1092 spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
1094 if (rtn == SUCCESS) {
1095 if (!scmd->device->host->hostt->skip_settle_delay)
1096 ssleep(HOST_RESET_SETTLE_TIME);
1097 spin_lock_irqsave(scmd->device->host->host_lock, flags);
1098 scsi_report_bus_reset(scmd->device->host, scmd->device->channel);
1099 spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
1106 * scsi_eh_bus_reset - send a bus reset
1107 * @shost: scsi host being recovered.
1108 * @eh_done_q: list_head for processed commands.
1110 static int scsi_eh_bus_reset(struct Scsi_Host *shost,
1111 struct list_head *work_q,
1112 struct list_head *done_q)
1114 struct list_head *lh, *lh_sf;
1115 struct scsi_cmnd *scmd;
1116 struct scsi_cmnd *chan_scmd;
1117 unsigned int channel;
1121 * we really want to loop over the various channels, and do this on
1122 * a channel by channel basis. we should also check to see if any
1123 * of the failed commands are on soft_reset devices, and if so, skip
1127 for (channel = 0; channel <= shost->max_channel; channel++) {
1129 list_for_each_entry(scmd, work_q, eh_entry) {
1130 if (channel == scmd->device->channel) {
1134 * FIXME add back in some support for
1135 * soft_reset devices.
1142 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BRST chan:"
1143 " %d\n", current->comm,
1145 rtn = scsi_try_bus_reset(chan_scmd);
1146 if (rtn == SUCCESS) {
1147 list_for_each_safe(lh, lh_sf, work_q) {
1148 scmd = list_entry(lh, struct scsi_cmnd,
1150 if (channel == scmd->device->channel)
1151 if (!scsi_device_online(scmd->device) ||
1153 scsi_eh_finish_cmd(scmd,
1157 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BRST"
1158 " failed chan: %d\n",
1163 return list_empty(work_q);
1167 * scsi_eh_host_reset - send a host reset
1168 * @work_q: list_head for processed commands.
1169 * @done_q: list_head for processed commands.
1171 static int scsi_eh_host_reset(struct list_head *work_q,
1172 struct list_head *done_q)
1175 struct list_head *lh, *lh_sf;
1176 struct scsi_cmnd *scmd;
1178 if (!list_empty(work_q)) {
1179 scmd = list_entry(work_q->next,
1180 struct scsi_cmnd, eh_entry);
1182 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending HRST\n"
1185 rtn = scsi_try_host_reset(scmd);
1186 if (rtn == SUCCESS) {
1187 list_for_each_safe(lh, lh_sf, work_q) {
1188 scmd = list_entry(lh, struct scsi_cmnd, eh_entry);
1189 if (!scsi_device_online(scmd->device) ||
1190 (!scsi_eh_try_stu(scmd) && !scsi_eh_tur(scmd)) ||
1192 scsi_eh_finish_cmd(scmd, done_q);
1195 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: HRST"
1200 return list_empty(work_q);
1204 * scsi_eh_offline_sdevs - offline scsi devices that fail to recover
1205 * @work_q: list_head for processed commands.
1206 * @done_q: list_head for processed commands.
1209 static void scsi_eh_offline_sdevs(struct list_head *work_q,
1210 struct list_head *done_q)
1212 struct list_head *lh, *lh_sf;
1213 struct scsi_cmnd *scmd;
1215 list_for_each_safe(lh, lh_sf, work_q) {
1216 scmd = list_entry(lh, struct scsi_cmnd, eh_entry);
1217 printk(KERN_INFO "scsi: Device offlined - not"
1218 " ready after error recovery: host"
1219 " %d channel %d id %d lun %d\n",
1220 scmd->device->host->host_no,
1221 scmd->device->channel,
1224 scsi_device_set_state(scmd->device, SDEV_OFFLINE);
1225 if (scsi_eh_eflags_chk(scmd, SCSI_EH_CANCEL_CMD)) {
1227 * FIXME: Handle lost cmds.
1230 scsi_eh_finish_cmd(scmd, done_q);
1236 * scsi_decide_disposition - Disposition a cmd on return from LLD.
1237 * @scmd: SCSI cmd to examine.
1240 * This is *only* called when we are examining the status after sending
1241 * out the actual data command. any commands that are queued for error
1242 * recovery (e.g. test_unit_ready) do *not* come through here.
1244 * When this routine returns failed, it means the error handler thread
1245 * is woken. In cases where the error code indicates an error that
1246 * doesn't require the error handler read (i.e. we don't need to
1247 * abort/reset), this function should return SUCCESS.
1249 int scsi_decide_disposition(struct scsi_cmnd *scmd)
1254 * if the device is offline, then we clearly just pass the result back
1255 * up to the top level.
1257 if (!scsi_device_online(scmd->device)) {
1258 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: device offline - report"
1265 * first check the host byte, to see if there is anything in there
1266 * that would indicate what we need to do.
1268 switch (host_byte(scmd->result)) {
1269 case DID_PASSTHROUGH:
1271 * no matter what, pass this through to the upper layer.
1272 * nuke this special code so that it looks like we are saying
1275 scmd->result &= 0xff00ffff;
1279 * looks good. drop through, and check the next byte.
1282 case DID_NO_CONNECT:
1283 case DID_BAD_TARGET:
1286 * note - this means that we just report the status back
1287 * to the top level driver, not that we actually think
1288 * that it indicates SUCCESS.
1292 * when the low level driver returns did_soft_error,
1293 * it is responsible for keeping an internal retry counter
1294 * in order to avoid endless loops (db)
1296 * actually this is a bug in this function here. we should
1297 * be mindful of the maximum number of retries specified
1298 * and not get stuck in a loop.
1300 case DID_SOFT_ERROR:
1306 return ADD_TO_MLQUEUE;
1309 if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
1310 status_byte(scmd->result) == RESERVATION_CONFLICT)
1312 * execute reservation conflict processing code
1323 * when we scan the bus, we get timeout messages for
1324 * these commands if there is no device available.
1325 * other hosts report did_no_connect for the same thing.
1327 if ((scmd->cmnd[0] == TEST_UNIT_READY ||
1328 scmd->cmnd[0] == INQUIRY)) {
1340 * next, check the message byte.
1342 if (msg_byte(scmd->result) != COMMAND_COMPLETE)
1346 * check the status byte to see if this indicates anything special.
1348 switch (status_byte(scmd->result)) {
1351 * the case of trying to send too many commands to a
1352 * tagged queueing device.
1356 * device can't talk to us at the moment. Should only
1357 * occur (SAM-3) when the task queue is empty, so will cause
1358 * the empty queue handling to trigger a stall in the
1361 return ADD_TO_MLQUEUE;
1363 case COMMAND_TERMINATED:
1366 case CHECK_CONDITION:
1367 rtn = scsi_check_sense(scmd);
1368 if (rtn == NEEDS_RETRY)
1370 /* if rtn == FAILED, we have no sense information;
1371 * returning FAILED will wake the error handler thread
1372 * to collect the sense and redo the decide
1375 case CONDITION_GOOD:
1376 case INTERMEDIATE_GOOD:
1377 case INTERMEDIATE_C_GOOD:
1380 * who knows? FIXME(eric)
1384 case RESERVATION_CONFLICT:
1385 printk(KERN_INFO "scsi: reservation conflict: host"
1386 " %d channel %d id %d lun %d\n",
1387 scmd->device->host->host_no, scmd->device->channel,
1388 scmd->device->id, scmd->device->lun);
1389 return SUCCESS; /* causes immediate i/o error */
1397 /* we requeue for retry because the error was retryable, and
1398 * the request was not marked fast fail. Note that above,
1399 * even if the request is marked fast fail, we still requeue
1400 * for queue congestion conditions (QUEUE_FULL or BUSY) */
1401 if ((++scmd->retries) < scmd->allowed
1402 && !blk_noretry_request(scmd->request)) {
1406 * no more retries - report this one back to upper level.
1413 * scsi_eh_lock_done - done function for eh door lock request
1414 * @scmd: SCSI command block for the door lock request
1417 * We completed the asynchronous door lock request, and it has either
1418 * locked the door or failed. We must free the command structures
1419 * associated with this request.
1421 static void scsi_eh_lock_done(struct scsi_cmnd *scmd)
1423 struct scsi_request *sreq = scmd->sc_request;
1425 scsi_release_request(sreq);
1430 * scsi_eh_lock_door - Prevent medium removal for the specified device
1431 * @sdev: SCSI device to prevent medium removal
1434 * We must be called from process context; scsi_allocate_request()
1438 * We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the
1439 * head of the devices request queue, and continue.
1442 * scsi_allocate_request() may sleep waiting for existing requests to
1443 * be processed. However, since we haven't kicked off any request
1444 * processing for this host, this may deadlock.
1446 * If scsi_allocate_request() fails for what ever reason, we
1447 * completely forget to lock the door.
1449 static void scsi_eh_lock_door(struct scsi_device *sdev)
1451 struct scsi_request *sreq = scsi_allocate_request(sdev, GFP_KERNEL);
1453 if (unlikely(!sreq)) {
1454 printk(KERN_ERR "%s: request allocate failed,"
1455 "prevent media removal cmd not sent\n", __FUNCTION__);
1459 sreq->sr_cmnd[0] = ALLOW_MEDIUM_REMOVAL;
1460 sreq->sr_cmnd[1] = 0;
1461 sreq->sr_cmnd[2] = 0;
1462 sreq->sr_cmnd[3] = 0;
1463 sreq->sr_cmnd[4] = SCSI_REMOVAL_PREVENT;
1464 sreq->sr_cmnd[5] = 0;
1465 sreq->sr_data_direction = DMA_NONE;
1466 sreq->sr_bufflen = 0;
1467 sreq->sr_buffer = NULL;
1468 sreq->sr_allowed = 5;
1469 sreq->sr_done = scsi_eh_lock_done;
1470 sreq->sr_timeout_per_command = 10 * HZ;
1471 sreq->sr_cmd_len = COMMAND_SIZE(sreq->sr_cmnd[0]);
1473 scsi_insert_special_req(sreq, 1);
1478 * scsi_restart_operations - restart io operations to the specified host.
1479 * @shost: Host we are restarting.
1482 * When we entered the error handler, we blocked all further i/o to
1483 * this device. we need to 'reverse' this process.
1485 static void scsi_restart_operations(struct Scsi_Host *shost)
1487 struct scsi_device *sdev;
1490 * If the door was locked, we need to insert a door lock request
1491 * onto the head of the SCSI request queue for the device. There
1492 * is no point trying to lock the door of an off-line device.
1494 shost_for_each_device(sdev, shost) {
1495 if (scsi_device_online(sdev) && sdev->locked)
1496 scsi_eh_lock_door(sdev);
1500 * next free up anything directly waiting upon the host. this
1501 * will be requests for character device operations, and also for
1502 * ioctls to queued block devices.
1504 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: waking up host to restart\n",
1507 clear_bit(SHOST_RECOVERY, &shost->shost_state);
1509 wake_up(&shost->host_wait);
1512 * finally we need to re-initiate requests that may be pending. we will
1513 * have had everything blocked while error handling is taking place, and
1514 * now that error recovery is done, we will need to ensure that these
1515 * requests are started.
1517 scsi_run_host_queues(shost);
1521 * scsi_eh_ready_devs - check device ready state and recover if not.
1522 * @shost: host to be recovered.
1523 * @eh_done_q: list_head for processed commands.
1526 static void scsi_eh_ready_devs(struct Scsi_Host *shost,
1527 struct list_head *work_q,
1528 struct list_head *done_q)
1530 if (!scsi_eh_stu(shost, work_q, done_q))
1531 if (!scsi_eh_bus_device_reset(shost, work_q, done_q))
1532 if (!scsi_eh_bus_reset(shost, work_q, done_q))
1533 if (!scsi_eh_host_reset(work_q, done_q))
1534 scsi_eh_offline_sdevs(work_q, done_q);
1538 * scsi_eh_flush_done_q - finish processed commands or retry them.
1539 * @done_q: list_head of processed commands.
1542 static void scsi_eh_flush_done_q(struct list_head *done_q)
1544 struct list_head *lh, *lh_sf;
1545 struct scsi_cmnd *scmd;
1547 list_for_each_safe(lh, lh_sf, done_q) {
1548 scmd = list_entry(lh, struct scsi_cmnd, eh_entry);
1550 if (scsi_device_online(scmd->device) &&
1551 !blk_noretry_request(scmd->request) &&
1552 (++scmd->retries < scmd->allowed)) {
1553 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush"
1557 scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY);
1560 * If just we got sense for the device (called
1561 * scsi_eh_get_sense), scmd->result is already
1562 * set, do not set DRIVER_TIMEOUT.
1565 scmd->result |= (DRIVER_TIMEOUT << 24);
1566 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush finish"
1568 current->comm, scmd));
1569 scsi_finish_command(scmd);
1575 * scsi_unjam_host - Attempt to fix a host which has a cmd that failed.
1576 * @shost: Host to unjam.
1579 * When we come in here, we *know* that all commands on the bus have
1580 * either completed, failed or timed out. we also know that no further
1581 * commands are being sent to the host, so things are relatively quiet
1582 * and we have freedom to fiddle with things as we wish.
1584 * This is only the *default* implementation. it is possible for
1585 * individual drivers to supply their own version of this function, and
1586 * if the maintainer wishes to do this, it is strongly suggested that
1587 * this function be taken as a template and modified. this function
1588 * was designed to correctly handle problems for about 95% of the
1589 * different cases out there, and it should always provide at least a
1590 * reasonable amount of error recovery.
1592 * Any command marked 'failed' or 'timeout' must eventually have
1593 * scsi_finish_cmd() called for it. we do all of the retry stuff
1594 * here, so when we restart the host after we return it should have an
1597 static void scsi_unjam_host(struct Scsi_Host *shost)
1599 unsigned long flags;
1600 LIST_HEAD(eh_work_q);
1601 LIST_HEAD(eh_done_q);
1603 spin_lock_irqsave(shost->host_lock, flags);
1604 list_splice_init(&shost->eh_cmd_q, &eh_work_q);
1605 spin_unlock_irqrestore(shost->host_lock, flags);
1607 SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(shost, &eh_work_q));
1609 if (!scsi_eh_get_sense(&eh_work_q, &eh_done_q))
1610 if (!scsi_eh_abort_cmds(&eh_work_q, &eh_done_q))
1611 scsi_eh_ready_devs(shost, &eh_work_q, &eh_done_q);
1613 scsi_eh_flush_done_q(&eh_done_q);
1617 * scsi_error_handler - Handle errors/timeouts of SCSI cmds.
1618 * @data: Host for which we are running.
1621 * This is always run in the context of a kernel thread. The idea is
1622 * that we start this thing up when the kernel starts up (one per host
1623 * that we detect), and it immediately goes to sleep and waits for some
1624 * event (i.e. failure). When this takes place, we have the job of
1625 * trying to unjam the bus and restarting things.
1627 int scsi_error_handler(void *data)
1629 struct Scsi_Host *shost = (struct Scsi_Host *) data;
1631 DECLARE_MUTEX_LOCKED(sem);
1637 daemonize("scsi_eh_%d", shost->host_no);
1639 current->flags |= PF_NOFREEZE;
1641 shost->eh_wait = &sem;
1642 shost->ehandler = current;
1645 * Wake up the thread that created us.
1647 SCSI_LOG_ERROR_RECOVERY(3, printk("Wake up parent of"
1648 " scsi_eh_%d\n",shost->host_no));
1650 complete(shost->eh_notify);
1654 * If we get a signal, it means we are supposed to go
1655 * away and die. This typically happens if the user is
1656 * trying to unload a module.
1658 SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler"
1660 " sleeping\n",shost->host_no));
1663 * Note - we always use down_interruptible with the semaphore
1664 * even if the module was loaded as part of the kernel. The
1665 * reason is that down() will cause this thread to be counted
1666 * in the load average as a running process, and down
1667 * interruptible doesn't. Given that we need to allow this
1668 * thread to die if the driver was loaded as a module, using
1669 * semaphores isn't unreasonable.
1671 down_interruptible(&sem);
1675 SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler"
1676 " scsi_eh_%d waking"
1677 " up\n",shost->host_no));
1679 shost->eh_active = 1;
1682 * We have a host that is failing for some reason. Figure out
1683 * what we need to do to get it up and online again (if we can).
1684 * If we fail, we end up taking the thing offline.
1686 if (shost->hostt->eh_strategy_handler)
1687 rtn = shost->hostt->eh_strategy_handler(shost);
1689 scsi_unjam_host(shost);
1691 shost->eh_active = 0;
1694 * Note - if the above fails completely, the action is to take
1695 * individual devices offline and flush the queue of any
1696 * outstanding requests that may have been pending. When we
1697 * restart, we restart any I/O to any other devices on the bus
1698 * which are still online.
1700 scsi_restart_operations(shost);
1704 SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler scsi_eh_%d"
1705 " exiting\n",shost->host_no));
1708 * Make sure that nobody tries to wake us up again.
1710 shost->eh_wait = NULL;
1713 * Knock this down too. From this point on, the host is flying
1714 * without a pilot. If this is because the module is being unloaded,
1715 * that's fine. If the user sent a signal to this thing, we are
1716 * potentially in real danger.
1718 shost->eh_active = 0;
1719 shost->ehandler = NULL;
1722 * If anyone is waiting for us to exit (i.e. someone trying to unload
1723 * a driver), then wake up that process to let them know we are on
1724 * the way out the door.
1726 complete_and_exit(shost->eh_notify, 0);
1731 * Function: scsi_report_bus_reset()
1733 * Purpose: Utility function used by low-level drivers to report that
1734 * they have observed a bus reset on the bus being handled.
1736 * Arguments: shost - Host in question
1737 * channel - channel on which reset was observed.
1741 * Lock status: Host lock must be held.
1743 * Notes: This only needs to be called if the reset is one which
1744 * originates from an unknown location. Resets originated
1745 * by the mid-level itself don't need to call this, but there
1746 * should be no harm.
1748 * The main purpose of this is to make sure that a CHECK_CONDITION
1749 * is properly treated.
1751 void scsi_report_bus_reset(struct Scsi_Host *shost, int channel)
1753 struct scsi_device *sdev;
1755 __shost_for_each_device(sdev, shost) {
1756 if (channel == sdev->channel) {
1757 sdev->was_reset = 1;
1758 sdev->expecting_cc_ua = 1;
1762 EXPORT_SYMBOL(scsi_report_bus_reset);
1765 * Function: scsi_report_device_reset()
1767 * Purpose: Utility function used by low-level drivers to report that
1768 * they have observed a device reset on the device being handled.
1770 * Arguments: shost - Host in question
1771 * channel - channel on which reset was observed
1772 * target - target on which reset was observed
1776 * Lock status: Host lock must be held
1778 * Notes: This only needs to be called if the reset is one which
1779 * originates from an unknown location. Resets originated
1780 * by the mid-level itself don't need to call this, but there
1781 * should be no harm.
1783 * The main purpose of this is to make sure that a CHECK_CONDITION
1784 * is properly treated.
1786 void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
1788 struct scsi_device *sdev;
1790 __shost_for_each_device(sdev, shost) {
1791 if (channel == sdev->channel &&
1792 target == sdev->id) {
1793 sdev->was_reset = 1;
1794 sdev->expecting_cc_ua = 1;
1798 EXPORT_SYMBOL(scsi_report_device_reset);
1801 scsi_reset_provider_done_command(struct scsi_cmnd *scmd)
1806 * Function: scsi_reset_provider
1808 * Purpose: Send requested reset to a bus or device at any phase.
1810 * Arguments: device - device to send reset to
1811 * flag - reset type (see scsi.h)
1813 * Returns: SUCCESS/FAILURE.
1815 * Notes: This is used by the SCSI Generic driver to provide
1816 * Bus/Device reset capability.
1819 scsi_reset_provider(struct scsi_device *dev, int flag)
1821 struct scsi_cmnd *scmd = scsi_get_command(dev, GFP_KERNEL);
1825 scmd->request = &req;
1826 memset(&scmd->eh_timeout, 0, sizeof(scmd->eh_timeout));
1827 scmd->request->rq_status = RQ_SCSI_BUSY;
1828 scmd->state = SCSI_STATE_INITIALIZING;
1829 scmd->owner = SCSI_OWNER_MIDLEVEL;
1831 memset(&scmd->cmnd, '\0', sizeof(scmd->cmnd));
1833 scmd->scsi_done = scsi_reset_provider_done_command;
1835 scmd->buffer = NULL;
1837 scmd->request_buffer = NULL;
1838 scmd->request_bufflen = 0;
1839 scmd->abort_reason = DID_ABORT;
1843 scmd->sc_data_direction = DMA_BIDIRECTIONAL;
1844 scmd->sc_request = NULL;
1845 scmd->sc_magic = SCSI_CMND_MAGIC;
1847 init_timer(&scmd->eh_timeout);
1850 * Sometimes the command can get back into the timer chain,
1851 * so use the pid as an identifier.
1856 case SCSI_TRY_RESET_DEVICE:
1857 rtn = scsi_try_bus_device_reset(scmd);
1861 case SCSI_TRY_RESET_BUS:
1862 rtn = scsi_try_bus_reset(scmd);
1866 case SCSI_TRY_RESET_HOST:
1867 rtn = scsi_try_host_reset(scmd);
1873 scsi_next_command(scmd);
1876 EXPORT_SYMBOL(scsi_reset_provider);
1879 * scsi_normalize_sense - normalize main elements from either fixed or
1880 * descriptor sense data format into a common format.
1882 * @sense_buffer: byte array containing sense data returned by device
1883 * @sb_len: number of valid bytes in sense_buffer
1884 * @sshdr: pointer to instance of structure that common
1885 * elements are written to.
1888 * The "main elements" from sense data are: response_code, sense_key,
1889 * asc, ascq and additional_length (only for descriptor format).
1891 * Typically this function can be called after a device has
1892 * responded to a SCSI command with the CHECK_CONDITION status.
1895 * 1 if valid sense data information found, else 0;
1897 int scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
1898 struct scsi_sense_hdr *sshdr)
1900 if (!sense_buffer || !sb_len || (sense_buffer[0] & 0x70) != 0x70)
1903 memset(sshdr, 0, sizeof(struct scsi_sense_hdr));
1905 sshdr->response_code = (sense_buffer[0] & 0x7f);
1906 if (sshdr->response_code >= 0x72) {
1911 sshdr->sense_key = (sense_buffer[1] & 0xf);
1913 sshdr->asc = sense_buffer[2];
1915 sshdr->ascq = sense_buffer[3];
1917 sshdr->additional_length = sense_buffer[7];
1923 sshdr->sense_key = (sense_buffer[2] & 0xf);
1925 sb_len = (sb_len < (sense_buffer[7] + 8)) ?
1926 sb_len : (sense_buffer[7] + 8);
1928 sshdr->asc = sense_buffer[12];
1930 sshdr->ascq = sense_buffer[13];
1936 EXPORT_SYMBOL(scsi_normalize_sense);
1938 int scsi_request_normalize_sense(struct scsi_request *sreq,
1939 struct scsi_sense_hdr *sshdr)
1941 return scsi_normalize_sense(sreq->sr_sense_buffer,
1942 sizeof(sreq->sr_sense_buffer), sshdr);
1944 EXPORT_SYMBOL(scsi_request_normalize_sense);
1946 int scsi_command_normalize_sense(struct scsi_cmnd *cmd,
1947 struct scsi_sense_hdr *sshdr)
1949 return scsi_normalize_sense(cmd->sense_buffer,
1950 sizeof(cmd->sense_buffer), sshdr);
1952 EXPORT_SYMBOL(scsi_command_normalize_sense);
1955 * scsi_sense_desc_find - search for a given descriptor type in
1956 * descriptor sense data format.
1958 * @sense_buffer: byte array of descriptor format sense data
1959 * @sb_len: number of valid bytes in sense_buffer
1960 * @desc_type: value of descriptor type to find
1961 * (e.g. 0 -> information)
1964 * only valid when sense data is in descriptor format
1967 * pointer to start of (first) descriptor if found else NULL
1969 const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
1972 int add_sen_len, add_len, desc_len, k;
1975 if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7])))
1977 if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73))
1979 add_sen_len = (add_sen_len < (sb_len - 8)) ?
1980 add_sen_len : (sb_len - 8);
1981 descp = &sense_buffer[8];
1982 for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) {
1984 add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
1985 desc_len = add_len + 2;
1986 if (descp[0] == desc_type)
1988 if (add_len < 0) // short descriptor ??
1993 EXPORT_SYMBOL(scsi_sense_desc_find);
1996 * scsi_get_sense_info_fld - attempts to get information field from
1997 * sense data (either fixed or descriptor format)
1999 * @sense_buffer: byte array of sense data
2000 * @sb_len: number of valid bytes in sense_buffer
2001 * @info_out: pointer to 64 integer where 8 or 4 byte information
2002 * field will be placed if found.
2005 * 1 if information field found, 0 if not found.
2007 int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len,
2016 switch (sense_buffer[0] & 0x7f) {
2019 if (sense_buffer[0] & 0x80) {
2020 *info_out = (sense_buffer[3] << 24) +
2021 (sense_buffer[4] << 16) +
2022 (sense_buffer[5] << 8) + sense_buffer[6];
2028 ucp = scsi_sense_desc_find(sense_buffer, sb_len,
2030 if (ucp && (0xa == ucp[1])) {
2032 for (j = 0; j < 8; ++j) {
2045 EXPORT_SYMBOL(scsi_get_sense_info_fld);