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/kernel.h>
22 #include <linux/freezer.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_cmnd.h>
30 #include <scsi/scsi_dbg.h>
31 #include <scsi/scsi_device.h>
32 #include <scsi/scsi_eh.h>
33 #include <scsi/scsi_transport.h>
34 #include <scsi/scsi_host.h>
35 #include <scsi/scsi_ioctl.h>
37 #include "scsi_priv.h"
38 #include "scsi_logging.h"
39 #include "scsi_transport_api.h"
41 #define SENSE_TIMEOUT (10*HZ)
44 * These should *probably* be handled by the host itself.
45 * Since it is allowed to sleep, it probably should.
47 #define BUS_RESET_SETTLE_TIME (10)
48 #define HOST_RESET_SETTLE_TIME (10)
50 /* called with shost->host_lock held */
51 void scsi_eh_wakeup(struct Scsi_Host *shost)
53 if (shost->host_busy == shost->host_failed) {
54 wake_up_process(shost->ehandler);
55 SCSI_LOG_ERROR_RECOVERY(5,
56 printk("Waking error handler thread\n"));
61 * scsi_schedule_eh - schedule EH for SCSI host
62 * @shost: SCSI host to invoke error handling on.
64 * Schedule SCSI EH without scmd.
66 void scsi_schedule_eh(struct Scsi_Host *shost)
70 spin_lock_irqsave(shost->host_lock, flags);
72 if (scsi_host_set_state(shost, SHOST_RECOVERY) == 0 ||
73 scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY) == 0) {
74 shost->host_eh_scheduled++;
75 scsi_eh_wakeup(shost);
78 spin_unlock_irqrestore(shost->host_lock, flags);
80 EXPORT_SYMBOL_GPL(scsi_schedule_eh);
83 * scsi_eh_scmd_add - add scsi cmd to error handling.
84 * @scmd: scmd to run eh on.
85 * @eh_flag: optional SCSI_EH flag.
90 int scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag)
92 struct Scsi_Host *shost = scmd->device->host;
99 spin_lock_irqsave(shost->host_lock, flags);
100 if (scsi_host_set_state(shost, SHOST_RECOVERY))
101 if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY))
105 scmd->eh_eflags |= eh_flag;
106 list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q);
107 shost->host_failed++;
108 scsi_eh_wakeup(shost);
110 spin_unlock_irqrestore(shost->host_lock, flags);
115 * scsi_add_timer - Start timeout timer for a single scsi command.
116 * @scmd: scsi command that is about to start running.
117 * @timeout: amount of time to allow this command to run.
118 * @complete: timeout function to call if timer isn't canceled.
121 * This should be turned into an inline function. Each scsi command
122 * has its own timer, and as it is added to the queue, we set up the
123 * timer. When the command completes, we cancel the timer.
125 void scsi_add_timer(struct scsi_cmnd *scmd, int timeout,
126 void (*complete)(struct scsi_cmnd *))
130 * If the clock was already running for this command, then
131 * first delete the timer. The timer handling code gets rather
132 * confused if we don't do this.
134 if (scmd->eh_timeout.function)
135 del_timer(&scmd->eh_timeout);
137 scmd->eh_timeout.data = (unsigned long)scmd;
138 scmd->eh_timeout.expires = jiffies + timeout;
139 scmd->eh_timeout.function = (void (*)(unsigned long)) complete;
141 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p, time:"
142 " %d, (%p)\n", __FUNCTION__,
143 scmd, timeout, complete));
145 add_timer(&scmd->eh_timeout);
149 * scsi_delete_timer - Delete/cancel timer for a given function.
150 * @scmd: Cmd that we are canceling timer for
153 * This should be turned into an inline function.
156 * 1 if we were able to detach the timer. 0 if we blew it, and the
157 * timer function has already started to run.
159 int scsi_delete_timer(struct scsi_cmnd *scmd)
163 rtn = del_timer(&scmd->eh_timeout);
165 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p,"
166 " rtn: %d\n", __FUNCTION__,
169 scmd->eh_timeout.data = (unsigned long)NULL;
170 scmd->eh_timeout.function = NULL;
176 * scsi_times_out - Timeout function for normal scsi commands.
177 * @scmd: Cmd that is timing out.
180 * We do not need to lock this. There is the potential for a race
181 * only in that the normal completion handling might run, but if the
182 * normal completion function determines that the timer has already
183 * fired, then it mustn't do anything.
185 void scsi_times_out(struct scsi_cmnd *scmd)
187 enum scsi_eh_timer_return (* eh_timed_out)(struct scsi_cmnd *);
189 scsi_log_completion(scmd, TIMEOUT_ERROR);
191 if (scmd->device->host->transportt->eh_timed_out)
192 eh_timed_out = scmd->device->host->transportt->eh_timed_out;
193 else if (scmd->device->host->hostt->eh_timed_out)
194 eh_timed_out = scmd->device->host->hostt->eh_timed_out;
199 switch (eh_timed_out(scmd)) {
204 scsi_add_timer(scmd, scmd->timeout_per_command,
211 if (unlikely(!scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD))) {
212 scmd->result |= DID_TIME_OUT << 16;
218 * scsi_block_when_processing_errors - Prevent cmds from being queued.
219 * @sdev: Device on which we are performing recovery.
222 * We block until the host is out of error recovery, and then check to
223 * see whether the host or the device is offline.
226 * 0 when dev was taken offline by error recovery. 1 OK to proceed.
228 int scsi_block_when_processing_errors(struct scsi_device *sdev)
232 wait_event(sdev->host->host_wait, !scsi_host_in_recovery(sdev->host));
234 online = scsi_device_online(sdev);
236 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: rtn: %d\n", __FUNCTION__,
241 EXPORT_SYMBOL(scsi_block_when_processing_errors);
243 #ifdef CONFIG_SCSI_LOGGING
245 * scsi_eh_prt_fail_stats - Log info on failures.
246 * @shost: scsi host being recovered.
247 * @work_q: Queue of scsi cmds to process.
249 static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost,
250 struct list_head *work_q)
252 struct scsi_cmnd *scmd;
253 struct scsi_device *sdev;
254 int total_failures = 0;
257 int devices_failed = 0;
259 shost_for_each_device(sdev, shost) {
260 list_for_each_entry(scmd, work_q, eh_entry) {
261 if (scmd->device == sdev) {
263 if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD)
270 if (cmd_cancel || cmd_failed) {
271 SCSI_LOG_ERROR_RECOVERY(3,
272 sdev_printk(KERN_INFO, sdev,
273 "%s: cmds failed: %d, cancel: %d\n",
274 __FUNCTION__, cmd_failed,
282 SCSI_LOG_ERROR_RECOVERY(2, printk("Total of %d commands on %d"
283 " devices require eh work\n",
284 total_failures, devices_failed));
289 * scsi_check_sense - Examine scsi cmd sense
290 * @scmd: Cmd to have sense checked.
293 * SUCCESS or FAILED or NEEDS_RETRY
296 * When a deferred error is detected the current command has
297 * not been executed and needs retrying.
299 static int scsi_check_sense(struct scsi_cmnd *scmd)
301 struct scsi_sense_hdr sshdr;
303 if (! scsi_command_normalize_sense(scmd, &sshdr))
304 return FAILED; /* no valid sense data */
306 if (scsi_sense_is_deferred(&sshdr))
310 * Previous logic looked for FILEMARK, EOM or ILI which are
311 * mainly associated with tapes and returned SUCCESS.
313 if (sshdr.response_code == 0x70) {
315 if (scmd->sense_buffer[2] & 0xe0)
319 * descriptor format: look for "stream commands sense data
320 * descriptor" (see SSC-3). Assume single sense data
321 * descriptor. Ignore ILI from SBC-2 READ LONG and WRITE LONG.
323 if ((sshdr.additional_length > 3) &&
324 (scmd->sense_buffer[8] == 0x4) &&
325 (scmd->sense_buffer[11] & 0xe0))
329 switch (sshdr.sense_key) {
332 case RECOVERED_ERROR:
333 return /* soft_error */ SUCCESS;
335 case ABORTED_COMMAND:
340 * if we are expecting a cc/ua because of a bus reset that we
341 * performed, treat this just as a retry. otherwise this is
342 * information that we should pass up to the upper-level driver
343 * so that we can deal with it there.
345 if (scmd->device->expecting_cc_ua) {
346 scmd->device->expecting_cc_ua = 0;
350 * if the device is in the process of becoming ready, we
353 if ((sshdr.asc == 0x04) && (sshdr.ascq == 0x01))
356 * if the device is not started, we need to wake
357 * the error handler to start the motor
359 if (scmd->device->allow_restart &&
360 (sshdr.asc == 0x04) && (sshdr.ascq == 0x02))
364 /* these three are not supported */
366 case VOLUME_OVERFLOW:
371 if (sshdr.asc == 0x11 || /* UNRECOVERED READ ERR */
372 sshdr.asc == 0x13 || /* AMNF DATA FIELD */
373 sshdr.asc == 0x14) { /* RECORD NOT FOUND */
379 if (scmd->device->retry_hwerror)
384 case ILLEGAL_REQUEST:
393 * scsi_eh_completed_normally - Disposition a eh cmd on return from LLD.
394 * @scmd: SCSI cmd to examine.
397 * This is *only* called when we are examining the status of commands
398 * queued during error recovery. the main difference here is that we
399 * don't allow for the possibility of retries here, and we are a lot
400 * more restrictive about what we consider acceptable.
402 static int scsi_eh_completed_normally(struct scsi_cmnd *scmd)
405 * first check the host byte, to see if there is anything in there
406 * that would indicate what we need to do.
408 if (host_byte(scmd->result) == DID_RESET) {
410 * rats. we are already in the error handler, so we now
411 * get to try and figure out what to do next. if the sense
412 * is valid, we have a pretty good idea of what to do.
413 * if not, we mark it as FAILED.
415 return scsi_check_sense(scmd);
417 if (host_byte(scmd->result) != DID_OK)
421 * next, check the message byte.
423 if (msg_byte(scmd->result) != COMMAND_COMPLETE)
427 * now, check the status byte to see if this indicates
430 switch (status_byte(scmd->result)) {
432 case COMMAND_TERMINATED:
434 case CHECK_CONDITION:
435 return scsi_check_sense(scmd);
437 case INTERMEDIATE_GOOD:
438 case INTERMEDIATE_C_GOOD:
440 * who knows? FIXME(eric)
445 case RESERVATION_CONFLICT:
453 * scsi_eh_done - Completion function for error handling.
454 * @scmd: Cmd that is done.
456 static void scsi_eh_done(struct scsi_cmnd *scmd)
458 struct completion *eh_action;
460 SCSI_LOG_ERROR_RECOVERY(3,
461 printk("%s scmd: %p result: %x\n",
462 __FUNCTION__, scmd, scmd->result));
464 eh_action = scmd->device->host->eh_action;
470 * scsi_try_host_reset - ask host adapter to reset itself
471 * @scmd: SCSI cmd to send hsot reset.
473 static int scsi_try_host_reset(struct scsi_cmnd *scmd)
478 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Host RST\n",
481 if (!scmd->device->host->hostt->eh_host_reset_handler)
484 rtn = scmd->device->host->hostt->eh_host_reset_handler(scmd);
486 if (rtn == SUCCESS) {
487 if (!scmd->device->host->hostt->skip_settle_delay)
488 ssleep(HOST_RESET_SETTLE_TIME);
489 spin_lock_irqsave(scmd->device->host->host_lock, flags);
490 scsi_report_bus_reset(scmd->device->host,
492 spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
499 * scsi_try_bus_reset - ask host to perform a bus reset
500 * @scmd: SCSI cmd to send bus reset.
502 static int scsi_try_bus_reset(struct scsi_cmnd *scmd)
507 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Bus RST\n",
510 if (!scmd->device->host->hostt->eh_bus_reset_handler)
513 rtn = scmd->device->host->hostt->eh_bus_reset_handler(scmd);
515 if (rtn == SUCCESS) {
516 if (!scmd->device->host->hostt->skip_settle_delay)
517 ssleep(BUS_RESET_SETTLE_TIME);
518 spin_lock_irqsave(scmd->device->host->host_lock, flags);
519 scsi_report_bus_reset(scmd->device->host,
521 spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
528 * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev
529 * @scmd: SCSI cmd used to send BDR
532 * There is no timeout for this operation. if this operation is
533 * unreliable for a given host, then the host itself needs to put a
534 * timer on it, and set the host back to a consistent state prior to
537 static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd)
541 if (!scmd->device->host->hostt->eh_device_reset_handler)
544 rtn = scmd->device->host->hostt->eh_device_reset_handler(scmd);
545 if (rtn == SUCCESS) {
546 scmd->device->was_reset = 1;
547 scmd->device->expecting_cc_ua = 1;
553 static int __scsi_try_to_abort_cmd(struct scsi_cmnd *scmd)
555 if (!scmd->device->host->hostt->eh_abort_handler)
558 return scmd->device->host->hostt->eh_abort_handler(scmd);
562 * scsi_try_to_abort_cmd - Ask host to abort a running command.
563 * @scmd: SCSI cmd to abort from Lower Level.
566 * This function will not return until the user's completion function
567 * has been called. there is no timeout on this operation. if the
568 * author of the low-level driver wishes this operation to be timed,
569 * they can provide this facility themselves. helper functions in
570 * scsi_error.c can be supplied to make this easier to do.
572 static int scsi_try_to_abort_cmd(struct scsi_cmnd *scmd)
575 * scsi_done was called just after the command timed out and before
576 * we had a chance to process it. (db)
578 if (scmd->serial_number == 0)
580 return __scsi_try_to_abort_cmd(scmd);
583 static void scsi_abort_eh_cmnd(struct scsi_cmnd *scmd)
585 if (__scsi_try_to_abort_cmd(scmd) != SUCCESS)
586 if (scsi_try_bus_device_reset(scmd) != SUCCESS)
587 if (scsi_try_bus_reset(scmd) != SUCCESS)
588 scsi_try_host_reset(scmd);
592 * scsi_eh_prep_cmnd - Save a scsi command info as part of error recory
593 * @scmd: SCSI command structure to hijack
594 * @ses: structure to save restore information
595 * @cmnd: CDB to send. Can be NULL if no new cmnd is needed
596 * @cmnd_size: size in bytes of @cmnd
597 * @sense_bytes: size of sense data to copy. or 0 (if != 0 @cmnd is ignored)
599 * This function is used to save a scsi command information before re-execution
600 * as part of the error recovery process. If @sense_bytes is 0 the command
601 * sent must be one that does not transfer any data. If @sense_bytes != 0
602 * @cmnd is ignored and this functions sets up a REQUEST_SENSE command
603 * and cmnd buffers to read @sense_bytes into @scmd->sense_buffer.
605 void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd, struct scsi_eh_save *ses,
606 unsigned char *cmnd, int cmnd_size, unsigned sense_bytes)
608 struct scsi_device *sdev = scmd->device;
611 * We need saved copies of a number of fields - this is because
612 * error handling may need to overwrite these with different values
613 * to run different commands, and once error handling is complete,
614 * we will need to restore these values prior to running the actual
617 ses->cmd_len = scmd->cmd_len;
618 memcpy(ses->cmnd, scmd->cmnd, sizeof(scmd->cmnd));
619 ses->data_direction = scmd->sc_data_direction;
620 ses->sdb = scmd->sdb;
621 ses->result = scmd->result;
623 memset(&scmd->sdb, 0, sizeof(scmd->sdb));
626 scmd->sdb.length = min_t(unsigned, SCSI_SENSE_BUFFERSIZE,
628 sg_init_one(&ses->sense_sgl, scmd->sense_buffer,
630 scmd->sdb.table.sgl = &ses->sense_sgl;
631 scmd->sc_data_direction = DMA_FROM_DEVICE;
632 scmd->sdb.table.nents = 1;
633 memset(scmd->cmnd, 0, sizeof(scmd->cmnd));
634 scmd->cmnd[0] = REQUEST_SENSE;
635 scmd->cmnd[4] = scmd->sdb.length;
636 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
638 scmd->sc_data_direction = DMA_NONE;
640 memset(scmd->cmnd, 0, sizeof(scmd->cmnd));
641 memcpy(scmd->cmnd, cmnd, cmnd_size);
642 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
648 if (sdev->scsi_level <= SCSI_2 && sdev->scsi_level != SCSI_UNKNOWN)
649 scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) |
650 (sdev->lun << 5 & 0xe0);
653 * Zero the sense buffer. The scsi spec mandates that any
654 * untransferred sense data should be interpreted as being zero.
656 memset(scmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
658 EXPORT_SYMBOL(scsi_eh_prep_cmnd);
661 * scsi_eh_restore_cmnd - Restore a scsi command info as part of error recory
662 * @scmd: SCSI command structure to restore
663 * @ses: saved information from a coresponding call to scsi_prep_eh_cmnd
665 * Undo any damage done by above scsi_prep_eh_cmnd().
667 void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd, struct scsi_eh_save *ses)
670 * Restore original data
672 scmd->cmd_len = ses->cmd_len;
673 memcpy(scmd->cmnd, ses->cmnd, sizeof(scmd->cmnd));
674 scmd->sc_data_direction = ses->data_direction;
675 scmd->sdb = ses->sdb;
676 scmd->result = ses->result;
678 EXPORT_SYMBOL(scsi_eh_restore_cmnd);
681 * scsi_send_eh_cmnd - submit a scsi command as part of error recory
682 * @scmd: SCSI command structure to hijack
684 * @cmnd_size: size in bytes of @cmnd
685 * @timeout: timeout for this request
686 * @sense_bytes: size of sense data to copy or 0
688 * This function is used to send a scsi command down to a target device
689 * as part of the error recovery process. See also scsi_eh_prep_cmnd() above.
692 * SUCCESS or FAILED or NEEDS_RETRY
694 static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
695 int cmnd_size, int timeout, unsigned sense_bytes)
697 struct scsi_device *sdev = scmd->device;
698 struct Scsi_Host *shost = sdev->host;
699 DECLARE_COMPLETION_ONSTACK(done);
700 unsigned long timeleft;
702 struct scsi_eh_save ses;
705 scsi_eh_prep_cmnd(scmd, &ses, cmnd, cmnd_size, sense_bytes);
706 shost->eh_action = &done;
708 spin_lock_irqsave(shost->host_lock, flags);
710 shost->hostt->queuecommand(scmd, scsi_eh_done);
711 spin_unlock_irqrestore(shost->host_lock, flags);
713 timeleft = wait_for_completion_timeout(&done, timeout);
715 shost->eh_action = NULL;
717 scsi_log_completion(scmd, SUCCESS);
719 SCSI_LOG_ERROR_RECOVERY(3,
720 printk("%s: scmd: %p, timeleft: %ld\n",
721 __FUNCTION__, scmd, timeleft));
724 * If there is time left scsi_eh_done got called, and we will
725 * examine the actual status codes to see whether the command
726 * actually did complete normally, else tell the host to forget
727 * about this command.
730 rtn = scsi_eh_completed_normally(scmd);
731 SCSI_LOG_ERROR_RECOVERY(3,
732 printk("%s: scsi_eh_completed_normally %x\n",
745 scsi_abort_eh_cmnd(scmd);
749 scsi_eh_restore_cmnd(scmd, &ses);
754 * scsi_request_sense - Request sense data from a particular target.
755 * @scmd: SCSI cmd for request sense.
758 * Some hosts automatically obtain this information, others require
759 * that we obtain it on our own. This function will *not* return until
760 * the command either times out, or it completes.
762 static int scsi_request_sense(struct scsi_cmnd *scmd)
764 return scsi_send_eh_cmnd(scmd, NULL, 0, SENSE_TIMEOUT, ~0);
768 * scsi_eh_finish_cmd - Handle a cmd that eh is finished with.
769 * @scmd: Original SCSI cmd that eh has finished.
770 * @done_q: Queue for processed commands.
773 * We don't want to use the normal command completion while we are are
774 * still handling errors - it may cause other commands to be queued,
775 * and that would disturb what we are doing. Thus we really want to
776 * keep a list of pending commands for final completion, and once we
777 * are ready to leave error handling we handle completion for real.
779 void scsi_eh_finish_cmd(struct scsi_cmnd *scmd, struct list_head *done_q)
781 scmd->device->host->host_failed--;
783 list_move_tail(&scmd->eh_entry, done_q);
785 EXPORT_SYMBOL(scsi_eh_finish_cmd);
788 * scsi_eh_get_sense - Get device sense data.
789 * @work_q: Queue of commands to process.
790 * @done_q: Queue of processed commands.
793 * See if we need to request sense information. if so, then get it
794 * now, so we have a better idea of what to do.
797 * This has the unfortunate side effect that if a shost adapter does
798 * not automatically request sense information, we end up shutting
799 * it down before we request it.
801 * All drivers should request sense information internally these days,
802 * so for now all I have to say is tough noogies if you end up in here.
804 * XXX: Long term this code should go away, but that needs an audit of
807 int scsi_eh_get_sense(struct list_head *work_q,
808 struct list_head *done_q)
810 struct scsi_cmnd *scmd, *next;
813 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
814 if ((scmd->eh_eflags & SCSI_EH_CANCEL_CMD) ||
815 SCSI_SENSE_VALID(scmd))
818 SCSI_LOG_ERROR_RECOVERY(2, scmd_printk(KERN_INFO, scmd,
819 "%s: requesting sense\n",
821 rtn = scsi_request_sense(scmd);
825 SCSI_LOG_ERROR_RECOVERY(3, printk("sense requested for %p"
826 " result %x\n", scmd,
828 SCSI_LOG_ERROR_RECOVERY(3, scsi_print_sense("bh", scmd));
830 rtn = scsi_decide_disposition(scmd);
833 * if the result was normal, then just pass it along to the
837 /* we don't want this command reissued, just
838 * finished with the sense data, so set
839 * retries to the max allowed to ensure it
840 * won't get reissued */
841 scmd->retries = scmd->allowed;
842 else if (rtn != NEEDS_RETRY)
845 scsi_eh_finish_cmd(scmd, done_q);
848 return list_empty(work_q);
850 EXPORT_SYMBOL_GPL(scsi_eh_get_sense);
853 * scsi_eh_tur - Send TUR to device.
854 * @scmd: &scsi_cmnd to send TUR
857 * 0 - Device is ready. 1 - Device NOT ready.
859 static int scsi_eh_tur(struct scsi_cmnd *scmd)
861 static unsigned char tur_command[6] = {TEST_UNIT_READY, 0, 0, 0, 0, 0};
862 int retry_cnt = 1, rtn;
865 rtn = scsi_send_eh_cmnd(scmd, tur_command, 6, SENSE_TIMEOUT, 0);
867 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n",
868 __FUNCTION__, scmd, rtn));
883 * scsi_eh_abort_cmds - abort pending commands.
884 * @work_q: &list_head for pending commands.
885 * @done_q: &list_head for processed commands.
888 * Try and see whether or not it makes sense to try and abort the
889 * running command. This only works out to be the case if we have one
890 * command that has timed out. If the command simply failed, it makes
891 * no sense to try and abort the command, since as far as the shost
892 * adapter is concerned, it isn't running.
894 static int scsi_eh_abort_cmds(struct list_head *work_q,
895 struct list_head *done_q)
897 struct scsi_cmnd *scmd, *next;
900 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
901 if (!(scmd->eh_eflags & SCSI_EH_CANCEL_CMD))
903 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting cmd:"
904 "0x%p\n", current->comm,
906 rtn = scsi_try_to_abort_cmd(scmd);
907 if (rtn == SUCCESS) {
908 scmd->eh_eflags &= ~SCSI_EH_CANCEL_CMD;
909 if (!scsi_device_online(scmd->device) ||
910 !scsi_eh_tur(scmd)) {
911 scsi_eh_finish_cmd(scmd, done_q);
915 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting"
922 return list_empty(work_q);
926 * scsi_eh_try_stu - Send START_UNIT to device.
927 * @scmd: &scsi_cmnd to send START_UNIT
930 * 0 - Device is ready. 1 - Device NOT ready.
932 static int scsi_eh_try_stu(struct scsi_cmnd *scmd)
934 static unsigned char stu_command[6] = {START_STOP, 0, 0, 0, 1, 0};
936 if (scmd->device->allow_restart) {
937 int i, rtn = NEEDS_RETRY;
939 for (i = 0; rtn == NEEDS_RETRY && i < 2; i++)
940 rtn = scsi_send_eh_cmnd(scmd, stu_command, 6,
941 scmd->device->timeout, 0);
951 * scsi_eh_stu - send START_UNIT if needed
952 * @shost: &scsi host being recovered.
953 * @work_q: &list_head for pending commands.
954 * @done_q: &list_head for processed commands.
957 * If commands are failing due to not ready, initializing command required,
958 * try revalidating the device, which will end up sending a start unit.
960 static int scsi_eh_stu(struct Scsi_Host *shost,
961 struct list_head *work_q,
962 struct list_head *done_q)
964 struct scsi_cmnd *scmd, *stu_scmd, *next;
965 struct scsi_device *sdev;
967 shost_for_each_device(sdev, shost) {
969 list_for_each_entry(scmd, work_q, eh_entry)
970 if (scmd->device == sdev && SCSI_SENSE_VALID(scmd) &&
971 scsi_check_sense(scmd) == FAILED ) {
979 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending START_UNIT to sdev:"
980 " 0x%p\n", current->comm, sdev));
982 if (!scsi_eh_try_stu(stu_scmd)) {
983 if (!scsi_device_online(sdev) ||
984 !scsi_eh_tur(stu_scmd)) {
985 list_for_each_entry_safe(scmd, next,
987 if (scmd->device == sdev)
988 scsi_eh_finish_cmd(scmd, done_q);
992 SCSI_LOG_ERROR_RECOVERY(3,
993 printk("%s: START_UNIT failed to sdev:"
994 " 0x%p\n", current->comm, sdev));
998 return list_empty(work_q);
1003 * scsi_eh_bus_device_reset - send bdr if needed
1004 * @shost: scsi host being recovered.
1005 * @work_q: &list_head for pending commands.
1006 * @done_q: &list_head for processed commands.
1009 * Try a bus device reset. Still, look to see whether we have multiple
1010 * devices that are jammed or not - if we have multiple devices, it
1011 * makes no sense to try bus_device_reset - we really would need to try
1012 * a bus_reset instead.
1014 static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
1015 struct list_head *work_q,
1016 struct list_head *done_q)
1018 struct scsi_cmnd *scmd, *bdr_scmd, *next;
1019 struct scsi_device *sdev;
1022 shost_for_each_device(sdev, shost) {
1024 list_for_each_entry(scmd, work_q, eh_entry)
1025 if (scmd->device == sdev) {
1033 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BDR sdev:"
1034 " 0x%p\n", current->comm,
1036 rtn = scsi_try_bus_device_reset(bdr_scmd);
1037 if (rtn == SUCCESS) {
1038 if (!scsi_device_online(sdev) ||
1039 !scsi_eh_tur(bdr_scmd)) {
1040 list_for_each_entry_safe(scmd, next,
1042 if (scmd->device == sdev)
1043 scsi_eh_finish_cmd(scmd,
1048 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BDR"
1056 return list_empty(work_q);
1060 * scsi_eh_bus_reset - send a bus reset
1061 * @shost: &scsi host being recovered.
1062 * @work_q: &list_head for pending commands.
1063 * @done_q: &list_head for processed commands.
1065 static int scsi_eh_bus_reset(struct Scsi_Host *shost,
1066 struct list_head *work_q,
1067 struct list_head *done_q)
1069 struct scsi_cmnd *scmd, *chan_scmd, *next;
1070 unsigned int channel;
1074 * we really want to loop over the various channels, and do this on
1075 * a channel by channel basis. we should also check to see if any
1076 * of the failed commands are on soft_reset devices, and if so, skip
1080 for (channel = 0; channel <= shost->max_channel; channel++) {
1082 list_for_each_entry(scmd, work_q, eh_entry) {
1083 if (channel == scmd_channel(scmd)) {
1087 * FIXME add back in some support for
1088 * soft_reset devices.
1095 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BRST chan:"
1096 " %d\n", current->comm,
1098 rtn = scsi_try_bus_reset(chan_scmd);
1099 if (rtn == SUCCESS) {
1100 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1101 if (channel == scmd_channel(scmd))
1102 if (!scsi_device_online(scmd->device) ||
1104 scsi_eh_finish_cmd(scmd,
1108 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BRST"
1109 " failed chan: %d\n",
1114 return list_empty(work_q);
1118 * scsi_eh_host_reset - send a host reset
1119 * @work_q: list_head for processed commands.
1120 * @done_q: list_head for processed commands.
1122 static int scsi_eh_host_reset(struct list_head *work_q,
1123 struct list_head *done_q)
1125 struct scsi_cmnd *scmd, *next;
1128 if (!list_empty(work_q)) {
1129 scmd = list_entry(work_q->next,
1130 struct scsi_cmnd, eh_entry);
1132 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending HRST\n"
1135 rtn = scsi_try_host_reset(scmd);
1136 if (rtn == SUCCESS) {
1137 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1138 if (!scsi_device_online(scmd->device) ||
1139 (!scsi_eh_try_stu(scmd) && !scsi_eh_tur(scmd)) ||
1141 scsi_eh_finish_cmd(scmd, done_q);
1144 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: HRST"
1149 return list_empty(work_q);
1153 * scsi_eh_offline_sdevs - offline scsi devices that fail to recover
1154 * @work_q: list_head for processed commands.
1155 * @done_q: list_head for processed commands.
1157 static void scsi_eh_offline_sdevs(struct list_head *work_q,
1158 struct list_head *done_q)
1160 struct scsi_cmnd *scmd, *next;
1162 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1163 sdev_printk(KERN_INFO, scmd->device, "Device offlined - "
1164 "not ready after error recovery\n");
1165 scsi_device_set_state(scmd->device, SDEV_OFFLINE);
1166 if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD) {
1168 * FIXME: Handle lost cmds.
1171 scsi_eh_finish_cmd(scmd, done_q);
1177 * scsi_decide_disposition - Disposition a cmd on return from LLD.
1178 * @scmd: SCSI cmd to examine.
1181 * This is *only* called when we are examining the status after sending
1182 * out the actual data command. any commands that are queued for error
1183 * recovery (e.g. test_unit_ready) do *not* come through here.
1185 * When this routine returns failed, it means the error handler thread
1186 * is woken. In cases where the error code indicates an error that
1187 * doesn't require the error handler read (i.e. we don't need to
1188 * abort/reset), this function should return SUCCESS.
1190 int scsi_decide_disposition(struct scsi_cmnd *scmd)
1195 * if the device is offline, then we clearly just pass the result back
1196 * up to the top level.
1198 if (!scsi_device_online(scmd->device)) {
1199 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: device offline - report"
1206 * first check the host byte, to see if there is anything in there
1207 * that would indicate what we need to do.
1209 switch (host_byte(scmd->result)) {
1210 case DID_PASSTHROUGH:
1212 * no matter what, pass this through to the upper layer.
1213 * nuke this special code so that it looks like we are saying
1216 scmd->result &= 0xff00ffff;
1220 * looks good. drop through, and check the next byte.
1223 case DID_NO_CONNECT:
1224 case DID_BAD_TARGET:
1227 * note - this means that we just report the status back
1228 * to the top level driver, not that we actually think
1229 * that it indicates SUCCESS.
1233 * when the low level driver returns did_soft_error,
1234 * it is responsible for keeping an internal retry counter
1235 * in order to avoid endless loops (db)
1237 * actually this is a bug in this function here. we should
1238 * be mindful of the maximum number of retries specified
1239 * and not get stuck in a loop.
1241 case DID_SOFT_ERROR:
1247 return ADD_TO_MLQUEUE;
1250 if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
1251 status_byte(scmd->result) == RESERVATION_CONFLICT)
1253 * execute reservation conflict processing code
1264 * when we scan the bus, we get timeout messages for
1265 * these commands if there is no device available.
1266 * other hosts report did_no_connect for the same thing.
1268 if ((scmd->cmnd[0] == TEST_UNIT_READY ||
1269 scmd->cmnd[0] == INQUIRY)) {
1281 * next, check the message byte.
1283 if (msg_byte(scmd->result) != COMMAND_COMPLETE)
1287 * check the status byte to see if this indicates anything special.
1289 switch (status_byte(scmd->result)) {
1292 * the case of trying to send too many commands to a
1293 * tagged queueing device.
1297 * device can't talk to us at the moment. Should only
1298 * occur (SAM-3) when the task queue is empty, so will cause
1299 * the empty queue handling to trigger a stall in the
1302 return ADD_TO_MLQUEUE;
1304 case COMMAND_TERMINATED:
1307 case CHECK_CONDITION:
1308 rtn = scsi_check_sense(scmd);
1309 if (rtn == NEEDS_RETRY)
1311 /* if rtn == FAILED, we have no sense information;
1312 * returning FAILED will wake the error handler thread
1313 * to collect the sense and redo the decide
1316 case CONDITION_GOOD:
1317 case INTERMEDIATE_GOOD:
1318 case INTERMEDIATE_C_GOOD:
1321 * who knows? FIXME(eric)
1325 case RESERVATION_CONFLICT:
1326 sdev_printk(KERN_INFO, scmd->device,
1327 "reservation conflict\n");
1328 return SUCCESS; /* causes immediate i/o error */
1336 /* we requeue for retry because the error was retryable, and
1337 * the request was not marked fast fail. Note that above,
1338 * even if the request is marked fast fail, we still requeue
1339 * for queue congestion conditions (QUEUE_FULL or BUSY) */
1340 if ((++scmd->retries) <= scmd->allowed
1341 && !blk_noretry_request(scmd->request)) {
1345 * no more retries - report this one back to upper level.
1352 * scsi_eh_lock_door - Prevent medium removal for the specified device
1353 * @sdev: SCSI device to prevent medium removal
1356 * We must be called from process context; scsi_allocate_request()
1360 * We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the
1361 * head of the devices request queue, and continue.
1364 * scsi_allocate_request() may sleep waiting for existing requests to
1365 * be processed. However, since we haven't kicked off any request
1366 * processing for this host, this may deadlock.
1368 * If scsi_allocate_request() fails for what ever reason, we
1369 * completely forget to lock the door.
1371 static void scsi_eh_lock_door(struct scsi_device *sdev)
1373 unsigned char cmnd[MAX_COMMAND_SIZE];
1375 cmnd[0] = ALLOW_MEDIUM_REMOVAL;
1379 cmnd[4] = SCSI_REMOVAL_PREVENT;
1382 scsi_execute_async(sdev, cmnd, 6, DMA_NONE, NULL, 0, 0, 10 * HZ,
1383 5, NULL, NULL, GFP_KERNEL);
1388 * scsi_restart_operations - restart io operations to the specified host.
1389 * @shost: Host we are restarting.
1392 * When we entered the error handler, we blocked all further i/o to
1393 * this device. we need to 'reverse' this process.
1395 static void scsi_restart_operations(struct Scsi_Host *shost)
1397 struct scsi_device *sdev;
1398 unsigned long flags;
1401 * If the door was locked, we need to insert a door lock request
1402 * onto the head of the SCSI request queue for the device. There
1403 * is no point trying to lock the door of an off-line device.
1405 shost_for_each_device(sdev, shost) {
1406 if (scsi_device_online(sdev) && sdev->locked)
1407 scsi_eh_lock_door(sdev);
1411 * next free up anything directly waiting upon the host. this
1412 * will be requests for character device operations, and also for
1413 * ioctls to queued block devices.
1415 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: waking up host to restart\n",
1418 spin_lock_irqsave(shost->host_lock, flags);
1419 if (scsi_host_set_state(shost, SHOST_RUNNING))
1420 if (scsi_host_set_state(shost, SHOST_CANCEL))
1421 BUG_ON(scsi_host_set_state(shost, SHOST_DEL));
1422 spin_unlock_irqrestore(shost->host_lock, flags);
1424 wake_up(&shost->host_wait);
1427 * finally we need to re-initiate requests that may be pending. we will
1428 * have had everything blocked while error handling is taking place, and
1429 * now that error recovery is done, we will need to ensure that these
1430 * requests are started.
1432 scsi_run_host_queues(shost);
1436 * scsi_eh_ready_devs - check device ready state and recover if not.
1437 * @shost: host to be recovered.
1438 * @work_q: &list_head for pending commands.
1439 * @done_q: &list_head for processed commands.
1441 void scsi_eh_ready_devs(struct Scsi_Host *shost,
1442 struct list_head *work_q,
1443 struct list_head *done_q)
1445 if (!scsi_eh_stu(shost, work_q, done_q))
1446 if (!scsi_eh_bus_device_reset(shost, work_q, done_q))
1447 if (!scsi_eh_bus_reset(shost, work_q, done_q))
1448 if (!scsi_eh_host_reset(work_q, done_q))
1449 scsi_eh_offline_sdevs(work_q, done_q);
1451 EXPORT_SYMBOL_GPL(scsi_eh_ready_devs);
1454 * scsi_eh_flush_done_q - finish processed commands or retry them.
1455 * @done_q: list_head of processed commands.
1457 void scsi_eh_flush_done_q(struct list_head *done_q)
1459 struct scsi_cmnd *scmd, *next;
1461 list_for_each_entry_safe(scmd, next, done_q, eh_entry) {
1462 list_del_init(&scmd->eh_entry);
1463 if (scsi_device_online(scmd->device) &&
1464 !blk_noretry_request(scmd->request) &&
1465 (++scmd->retries <= scmd->allowed)) {
1466 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush"
1470 scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY);
1473 * If just we got sense for the device (called
1474 * scsi_eh_get_sense), scmd->result is already
1475 * set, do not set DRIVER_TIMEOUT.
1478 scmd->result |= (DRIVER_TIMEOUT << 24);
1479 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush finish"
1481 current->comm, scmd));
1482 scsi_finish_command(scmd);
1486 EXPORT_SYMBOL(scsi_eh_flush_done_q);
1489 * scsi_unjam_host - Attempt to fix a host which has a cmd that failed.
1490 * @shost: Host to unjam.
1493 * When we come in here, we *know* that all commands on the bus have
1494 * either completed, failed or timed out. we also know that no further
1495 * commands are being sent to the host, so things are relatively quiet
1496 * and we have freedom to fiddle with things as we wish.
1498 * This is only the *default* implementation. it is possible for
1499 * individual drivers to supply their own version of this function, and
1500 * if the maintainer wishes to do this, it is strongly suggested that
1501 * this function be taken as a template and modified. this function
1502 * was designed to correctly handle problems for about 95% of the
1503 * different cases out there, and it should always provide at least a
1504 * reasonable amount of error recovery.
1506 * Any command marked 'failed' or 'timeout' must eventually have
1507 * scsi_finish_cmd() called for it. we do all of the retry stuff
1508 * here, so when we restart the host after we return it should have an
1511 static void scsi_unjam_host(struct Scsi_Host *shost)
1513 unsigned long flags;
1514 LIST_HEAD(eh_work_q);
1515 LIST_HEAD(eh_done_q);
1517 spin_lock_irqsave(shost->host_lock, flags);
1518 list_splice_init(&shost->eh_cmd_q, &eh_work_q);
1519 spin_unlock_irqrestore(shost->host_lock, flags);
1521 SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(shost, &eh_work_q));
1523 if (!scsi_eh_get_sense(&eh_work_q, &eh_done_q))
1524 if (!scsi_eh_abort_cmds(&eh_work_q, &eh_done_q))
1525 scsi_eh_ready_devs(shost, &eh_work_q, &eh_done_q);
1527 scsi_eh_flush_done_q(&eh_done_q);
1531 * scsi_error_handler - SCSI error handler thread
1532 * @data: Host for which we are running.
1535 * This is the main error handling loop. This is run as a kernel thread
1536 * for every SCSI host and handles all error handling activity.
1538 int scsi_error_handler(void *data)
1540 struct Scsi_Host *shost = data;
1543 * We use TASK_INTERRUPTIBLE so that the thread is not
1544 * counted against the load average as a running process.
1545 * We never actually get interrupted because kthread_run
1546 * disables singal delivery for the created thread.
1548 set_current_state(TASK_INTERRUPTIBLE);
1549 while (!kthread_should_stop()) {
1550 if ((shost->host_failed == 0 && shost->host_eh_scheduled == 0) ||
1551 shost->host_failed != shost->host_busy) {
1552 SCSI_LOG_ERROR_RECOVERY(1,
1553 printk("Error handler scsi_eh_%d sleeping\n",
1556 set_current_state(TASK_INTERRUPTIBLE);
1560 __set_current_state(TASK_RUNNING);
1561 SCSI_LOG_ERROR_RECOVERY(1,
1562 printk("Error handler scsi_eh_%d waking up\n",
1566 * We have a host that is failing for some reason. Figure out
1567 * what we need to do to get it up and online again (if we can).
1568 * If we fail, we end up taking the thing offline.
1570 if (shost->transportt->eh_strategy_handler)
1571 shost->transportt->eh_strategy_handler(shost);
1573 scsi_unjam_host(shost);
1576 * Note - if the above fails completely, the action is to take
1577 * individual devices offline and flush the queue of any
1578 * outstanding requests that may have been pending. When we
1579 * restart, we restart any I/O to any other devices on the bus
1580 * which are still online.
1582 scsi_restart_operations(shost);
1583 set_current_state(TASK_INTERRUPTIBLE);
1585 __set_current_state(TASK_RUNNING);
1587 SCSI_LOG_ERROR_RECOVERY(1,
1588 printk("Error handler scsi_eh_%d exiting\n", shost->host_no));
1589 shost->ehandler = NULL;
1594 * Function: scsi_report_bus_reset()
1596 * Purpose: Utility function used by low-level drivers to report that
1597 * they have observed a bus reset on the bus being handled.
1599 * Arguments: shost - Host in question
1600 * channel - channel on which reset was observed.
1604 * Lock status: Host lock must be held.
1606 * Notes: This only needs to be called if the reset is one which
1607 * originates from an unknown location. Resets originated
1608 * by the mid-level itself don't need to call this, but there
1609 * should be no harm.
1611 * The main purpose of this is to make sure that a CHECK_CONDITION
1612 * is properly treated.
1614 void scsi_report_bus_reset(struct Scsi_Host *shost, int channel)
1616 struct scsi_device *sdev;
1618 __shost_for_each_device(sdev, shost) {
1619 if (channel == sdev_channel(sdev)) {
1620 sdev->was_reset = 1;
1621 sdev->expecting_cc_ua = 1;
1625 EXPORT_SYMBOL(scsi_report_bus_reset);
1628 * Function: scsi_report_device_reset()
1630 * Purpose: Utility function used by low-level drivers to report that
1631 * they have observed a device reset on the device being handled.
1633 * Arguments: shost - Host in question
1634 * channel - channel on which reset was observed
1635 * target - target on which reset was observed
1639 * Lock status: Host lock must be held
1641 * Notes: This only needs to be called if the reset is one which
1642 * originates from an unknown location. Resets originated
1643 * by the mid-level itself don't need to call this, but there
1644 * should be no harm.
1646 * The main purpose of this is to make sure that a CHECK_CONDITION
1647 * is properly treated.
1649 void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
1651 struct scsi_device *sdev;
1653 __shost_for_each_device(sdev, shost) {
1654 if (channel == sdev_channel(sdev) &&
1655 target == sdev_id(sdev)) {
1656 sdev->was_reset = 1;
1657 sdev->expecting_cc_ua = 1;
1661 EXPORT_SYMBOL(scsi_report_device_reset);
1664 scsi_reset_provider_done_command(struct scsi_cmnd *scmd)
1669 * Function: scsi_reset_provider
1671 * Purpose: Send requested reset to a bus or device at any phase.
1673 * Arguments: device - device to send reset to
1674 * flag - reset type (see scsi.h)
1676 * Returns: SUCCESS/FAILURE.
1678 * Notes: This is used by the SCSI Generic driver to provide
1679 * Bus/Device reset capability.
1682 scsi_reset_provider(struct scsi_device *dev, int flag)
1684 struct scsi_cmnd *scmd = scsi_get_command(dev, GFP_KERNEL);
1685 struct Scsi_Host *shost = dev->host;
1687 unsigned long flags;
1690 scmd->request = &req;
1691 memset(&scmd->eh_timeout, 0, sizeof(scmd->eh_timeout));
1693 memset(&scmd->cmnd, '\0', sizeof(scmd->cmnd));
1695 scmd->scsi_done = scsi_reset_provider_done_command;
1696 memset(&scmd->sdb, 0, sizeof(scmd->sdb));
1700 scmd->sc_data_direction = DMA_BIDIRECTIONAL;
1702 init_timer(&scmd->eh_timeout);
1704 spin_lock_irqsave(shost->host_lock, flags);
1705 shost->tmf_in_progress = 1;
1706 spin_unlock_irqrestore(shost->host_lock, flags);
1709 case SCSI_TRY_RESET_DEVICE:
1710 rtn = scsi_try_bus_device_reset(scmd);
1714 case SCSI_TRY_RESET_BUS:
1715 rtn = scsi_try_bus_reset(scmd);
1719 case SCSI_TRY_RESET_HOST:
1720 rtn = scsi_try_host_reset(scmd);
1726 spin_lock_irqsave(shost->host_lock, flags);
1727 shost->tmf_in_progress = 0;
1728 spin_unlock_irqrestore(shost->host_lock, flags);
1731 * be sure to wake up anyone who was sleeping or had their queue
1732 * suspended while we performed the TMF.
1734 SCSI_LOG_ERROR_RECOVERY(3,
1735 printk("%s: waking up host to restart after TMF\n",
1738 wake_up(&shost->host_wait);
1740 scsi_run_host_queues(shost);
1742 scsi_next_command(scmd);
1745 EXPORT_SYMBOL(scsi_reset_provider);
1748 * scsi_normalize_sense - normalize main elements from either fixed or
1749 * descriptor sense data format into a common format.
1751 * @sense_buffer: byte array containing sense data returned by device
1752 * @sb_len: number of valid bytes in sense_buffer
1753 * @sshdr: pointer to instance of structure that common
1754 * elements are written to.
1757 * The "main elements" from sense data are: response_code, sense_key,
1758 * asc, ascq and additional_length (only for descriptor format).
1760 * Typically this function can be called after a device has
1761 * responded to a SCSI command with the CHECK_CONDITION status.
1764 * 1 if valid sense data information found, else 0;
1766 int scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
1767 struct scsi_sense_hdr *sshdr)
1769 if (!sense_buffer || !sb_len)
1772 memset(sshdr, 0, sizeof(struct scsi_sense_hdr));
1774 sshdr->response_code = (sense_buffer[0] & 0x7f);
1776 if (!scsi_sense_valid(sshdr))
1779 if (sshdr->response_code >= 0x72) {
1784 sshdr->sense_key = (sense_buffer[1] & 0xf);
1786 sshdr->asc = sense_buffer[2];
1788 sshdr->ascq = sense_buffer[3];
1790 sshdr->additional_length = sense_buffer[7];
1796 sshdr->sense_key = (sense_buffer[2] & 0xf);
1798 sb_len = (sb_len < (sense_buffer[7] + 8)) ?
1799 sb_len : (sense_buffer[7] + 8);
1801 sshdr->asc = sense_buffer[12];
1803 sshdr->ascq = sense_buffer[13];
1809 EXPORT_SYMBOL(scsi_normalize_sense);
1811 int scsi_command_normalize_sense(struct scsi_cmnd *cmd,
1812 struct scsi_sense_hdr *sshdr)
1814 return scsi_normalize_sense(cmd->sense_buffer,
1815 SCSI_SENSE_BUFFERSIZE, sshdr);
1817 EXPORT_SYMBOL(scsi_command_normalize_sense);
1820 * scsi_sense_desc_find - search for a given descriptor type in descriptor sense data format.
1821 * @sense_buffer: byte array of descriptor format sense data
1822 * @sb_len: number of valid bytes in sense_buffer
1823 * @desc_type: value of descriptor type to find
1824 * (e.g. 0 -> information)
1827 * only valid when sense data is in descriptor format
1830 * pointer to start of (first) descriptor if found else NULL
1832 const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
1835 int add_sen_len, add_len, desc_len, k;
1838 if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7])))
1840 if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73))
1842 add_sen_len = (add_sen_len < (sb_len - 8)) ?
1843 add_sen_len : (sb_len - 8);
1844 descp = &sense_buffer[8];
1845 for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) {
1847 add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
1848 desc_len = add_len + 2;
1849 if (descp[0] == desc_type)
1851 if (add_len < 0) // short descriptor ??
1856 EXPORT_SYMBOL(scsi_sense_desc_find);
1859 * scsi_get_sense_info_fld - get information field from sense data (either fixed or descriptor format)
1860 * @sense_buffer: byte array of sense data
1861 * @sb_len: number of valid bytes in sense_buffer
1862 * @info_out: pointer to 64 integer where 8 or 4 byte information
1863 * field will be placed if found.
1866 * 1 if information field found, 0 if not found.
1868 int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len,
1877 switch (sense_buffer[0] & 0x7f) {
1880 if (sense_buffer[0] & 0x80) {
1881 *info_out = (sense_buffer[3] << 24) +
1882 (sense_buffer[4] << 16) +
1883 (sense_buffer[5] << 8) + sense_buffer[6];
1889 ucp = scsi_sense_desc_find(sense_buffer, sb_len,
1891 if (ucp && (0xa == ucp[1])) {
1893 for (j = 0; j < 8; ++j) {
1906 EXPORT_SYMBOL(scsi_get_sense_info_fld);