2 * scsi_error.c Copyright (C) 1997 Eric Youngdale
4 * SCSI error/timeout handling
5 * Initial versions: Eric Youngdale. Based upon conversations with
6 * Leonard Zubkoff and David Miller at Linux Expo,
7 * ideas originating from all over the place.
9 * Restructured scsi_unjam_host and associated functions.
10 * September 04, 2002 Mike Anderson (andmike@us.ibm.com)
12 * Forward port of Russell King's (rmk@arm.linux.org.uk) changes and
14 * September 30, 2002 Mike Anderson (andmike@us.ibm.com)
17 #include <linux/module.h>
18 #include <linux/sched.h>
19 #include <linux/timer.h>
20 #include <linux/string.h>
21 #include <linux/slab.h>
22 #include <linux/kernel.h>
23 #include <linux/kthread.h>
24 #include <linux/interrupt.h>
25 #include <linux/blkdev.h>
26 #include <linux/delay.h>
28 #include <scsi/scsi.h>
29 #include <scsi/scsi_dbg.h>
30 #include <scsi/scsi_device.h>
31 #include <scsi/scsi_eh.h>
32 #include <scsi/scsi_host.h>
33 #include <scsi/scsi_ioctl.h>
34 #include <scsi/scsi_request.h>
36 #include "scsi_priv.h"
37 #include "scsi_logging.h"
39 #define SENSE_TIMEOUT (10*HZ)
40 #define START_UNIT_TIMEOUT (30*HZ)
43 * These should *probably* be handled by the host itself.
44 * Since it is allowed to sleep, it probably should.
46 #define BUS_RESET_SETTLE_TIME (10)
47 #define HOST_RESET_SETTLE_TIME (10)
49 /* called with shost->host_lock held */
50 void scsi_eh_wakeup(struct Scsi_Host *shost)
52 if (shost->host_busy == shost->host_failed) {
53 wake_up_process(shost->ehandler);
54 SCSI_LOG_ERROR_RECOVERY(5,
55 printk("Waking error handler thread\n"));
60 * scsi_eh_scmd_add - add scsi cmd to error handling.
61 * @scmd: scmd to run eh on.
62 * @eh_flag: optional SCSI_EH flag.
67 int scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag)
69 struct Scsi_Host *shost = scmd->device->host;
76 spin_lock_irqsave(shost->host_lock, flags);
77 if (scsi_host_set_state(shost, SHOST_RECOVERY))
78 if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY))
82 scmd->eh_eflags |= eh_flag;
83 list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q);
85 scsi_eh_wakeup(shost);
87 spin_unlock_irqrestore(shost->host_lock, flags);
92 * scsi_add_timer - Start timeout timer for a single scsi command.
93 * @scmd: scsi command that is about to start running.
94 * @timeout: amount of time to allow this command to run.
95 * @complete: timeout function to call if timer isn't canceled.
98 * This should be turned into an inline function. Each scsi command
99 * has its own timer, and as it is added to the queue, we set up the
100 * timer. When the command completes, we cancel the timer.
102 void scsi_add_timer(struct scsi_cmnd *scmd, int timeout,
103 void (*complete)(struct scsi_cmnd *))
107 * If the clock was already running for this command, then
108 * first delete the timer. The timer handling code gets rather
109 * confused if we don't do this.
111 if (scmd->eh_timeout.function)
112 del_timer(&scmd->eh_timeout);
114 scmd->eh_timeout.data = (unsigned long)scmd;
115 scmd->eh_timeout.expires = jiffies + timeout;
116 scmd->eh_timeout.function = (void (*)(unsigned long)) complete;
118 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p, time:"
119 " %d, (%p)\n", __FUNCTION__,
120 scmd, timeout, complete));
122 add_timer(&scmd->eh_timeout);
126 * scsi_delete_timer - Delete/cancel timer for a given function.
127 * @scmd: Cmd that we are canceling timer for
130 * This should be turned into an inline function.
133 * 1 if we were able to detach the timer. 0 if we blew it, and the
134 * timer function has already started to run.
136 int scsi_delete_timer(struct scsi_cmnd *scmd)
140 rtn = del_timer(&scmd->eh_timeout);
142 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p,"
143 " rtn: %d\n", __FUNCTION__,
146 scmd->eh_timeout.data = (unsigned long)NULL;
147 scmd->eh_timeout.function = NULL;
153 * scsi_times_out - Timeout function for normal scsi commands.
154 * @scmd: Cmd that is timing out.
157 * We do not need to lock this. There is the potential for a race
158 * only in that the normal completion handling might run, but if the
159 * normal completion function determines that the timer has already
160 * fired, then it mustn't do anything.
162 void scsi_times_out(struct scsi_cmnd *scmd)
164 scsi_log_completion(scmd, TIMEOUT_ERROR);
166 if (scmd->device->host->hostt->eh_timed_out)
167 switch (scmd->device->host->hostt->eh_timed_out(scmd)) {
172 /* This allows a single retry even of a command
173 * with allowed == 0 */
174 if (scmd->retries++ > scmd->allowed)
176 scsi_add_timer(scmd, scmd->timeout_per_command,
183 if (unlikely(!scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD))) {
184 scmd->result |= DID_TIME_OUT << 16;
190 * scsi_block_when_processing_errors - Prevent cmds from being queued.
191 * @sdev: Device on which we are performing recovery.
194 * We block until the host is out of error recovery, and then check to
195 * see whether the host or the device is offline.
198 * 0 when dev was taken offline by error recovery. 1 OK to proceed.
200 int scsi_block_when_processing_errors(struct scsi_device *sdev)
204 wait_event(sdev->host->host_wait, !scsi_host_in_recovery(sdev->host));
206 online = scsi_device_online(sdev);
208 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: rtn: %d\n", __FUNCTION__,
213 EXPORT_SYMBOL(scsi_block_when_processing_errors);
215 #ifdef CONFIG_SCSI_LOGGING
217 * scsi_eh_prt_fail_stats - Log info on failures.
218 * @shost: scsi host being recovered.
219 * @work_q: Queue of scsi cmds to process.
221 static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost,
222 struct list_head *work_q)
224 struct scsi_cmnd *scmd;
225 struct scsi_device *sdev;
226 int total_failures = 0;
229 int devices_failed = 0;
231 shost_for_each_device(sdev, shost) {
232 list_for_each_entry(scmd, work_q, eh_entry) {
233 if (scmd->device == sdev) {
235 if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD)
242 if (cmd_cancel || cmd_failed) {
243 SCSI_LOG_ERROR_RECOVERY(3,
244 sdev_printk(KERN_INFO, sdev,
245 "%s: cmds failed: %d, cancel: %d\n",
246 __FUNCTION__, cmd_failed,
254 SCSI_LOG_ERROR_RECOVERY(2, printk("Total of %d commands on %d"
255 " devices require eh work\n",
256 total_failures, devices_failed));
261 * scsi_check_sense - Examine scsi cmd sense
262 * @scmd: Cmd to have sense checked.
265 * SUCCESS or FAILED or NEEDS_RETRY
268 * When a deferred error is detected the current command has
269 * not been executed and needs retrying.
271 static int scsi_check_sense(struct scsi_cmnd *scmd)
273 struct scsi_sense_hdr sshdr;
275 if (! scsi_command_normalize_sense(scmd, &sshdr))
276 return FAILED; /* no valid sense data */
278 if (scsi_sense_is_deferred(&sshdr))
282 * Previous logic looked for FILEMARK, EOM or ILI which are
283 * mainly associated with tapes and returned SUCCESS.
285 if (sshdr.response_code == 0x70) {
287 if (scmd->sense_buffer[2] & 0xe0)
291 * descriptor format: look for "stream commands sense data
292 * descriptor" (see SSC-3). Assume single sense data
293 * descriptor. Ignore ILI from SBC-2 READ LONG and WRITE LONG.
295 if ((sshdr.additional_length > 3) &&
296 (scmd->sense_buffer[8] == 0x4) &&
297 (scmd->sense_buffer[11] & 0xe0))
301 switch (sshdr.sense_key) {
304 case RECOVERED_ERROR:
305 return /* soft_error */ SUCCESS;
307 case ABORTED_COMMAND:
312 * if we are expecting a cc/ua because of a bus reset that we
313 * performed, treat this just as a retry. otherwise this is
314 * information that we should pass up to the upper-level driver
315 * so that we can deal with it there.
317 if (scmd->device->expecting_cc_ua) {
318 scmd->device->expecting_cc_ua = 0;
322 * if the device is in the process of becoming ready, we
325 if ((sshdr.asc == 0x04) && (sshdr.ascq == 0x01))
328 * if the device is not started, we need to wake
329 * the error handler to start the motor
331 if (scmd->device->allow_restart &&
332 (sshdr.asc == 0x04) && (sshdr.ascq == 0x02))
336 /* these three are not supported */
338 case VOLUME_OVERFLOW:
346 if (scmd->device->retry_hwerror)
351 case ILLEGAL_REQUEST:
360 * scsi_eh_completed_normally - Disposition a eh cmd on return from LLD.
361 * @scmd: SCSI cmd to examine.
364 * This is *only* called when we are examining the status of commands
365 * queued during error recovery. the main difference here is that we
366 * don't allow for the possibility of retries here, and we are a lot
367 * more restrictive about what we consider acceptable.
369 static int scsi_eh_completed_normally(struct scsi_cmnd *scmd)
372 * first check the host byte, to see if there is anything in there
373 * that would indicate what we need to do.
375 if (host_byte(scmd->result) == DID_RESET) {
377 * rats. we are already in the error handler, so we now
378 * get to try and figure out what to do next. if the sense
379 * is valid, we have a pretty good idea of what to do.
380 * if not, we mark it as FAILED.
382 return scsi_check_sense(scmd);
384 if (host_byte(scmd->result) != DID_OK)
388 * next, check the message byte.
390 if (msg_byte(scmd->result) != COMMAND_COMPLETE)
394 * now, check the status byte to see if this indicates
397 switch (status_byte(scmd->result)) {
399 case COMMAND_TERMINATED:
401 case CHECK_CONDITION:
402 return scsi_check_sense(scmd);
404 case INTERMEDIATE_GOOD:
405 case INTERMEDIATE_C_GOOD:
407 * who knows? FIXME(eric)
412 case RESERVATION_CONFLICT:
420 * scsi_eh_done - Completion function for error handling.
421 * @scmd: Cmd that is done.
423 static void scsi_eh_done(struct scsi_cmnd *scmd)
425 struct completion *eh_action;
427 SCSI_LOG_ERROR_RECOVERY(3,
428 printk("%s scmd: %p result: %x\n",
429 __FUNCTION__, scmd, scmd->result));
431 eh_action = scmd->device->host->eh_action;
437 * scsi_send_eh_cmnd - send a cmd to a device as part of error recovery.
438 * @scmd: SCSI Cmd to send.
439 * @timeout: Timeout for cmd.
442 * SUCCESS or FAILED or NEEDS_RETRY
444 static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, int timeout)
446 struct scsi_device *sdev = scmd->device;
447 struct Scsi_Host *shost = sdev->host;
448 DECLARE_COMPLETION(done);
449 unsigned long timeleft;
453 if (sdev->scsi_level <= SCSI_2)
454 scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) |
455 (sdev->lun << 5 & 0xe0);
457 shost->eh_action = &done;
458 scmd->request->rq_status = RQ_SCSI_BUSY;
460 spin_lock_irqsave(shost->host_lock, flags);
462 shost->hostt->queuecommand(scmd, scsi_eh_done);
463 spin_unlock_irqrestore(shost->host_lock, flags);
465 timeleft = wait_for_completion_timeout(&done, timeout);
467 scmd->request->rq_status = RQ_SCSI_DONE;
468 shost->eh_action = NULL;
470 scsi_log_completion(scmd, SUCCESS);
472 SCSI_LOG_ERROR_RECOVERY(3,
473 printk("%s: scmd: %p, timeleft: %ld\n",
474 __FUNCTION__, scmd, timeleft));
477 * If there is time left scsi_eh_done got called, and we will
478 * examine the actual status codes to see whether the command
479 * actually did complete normally, else tell the host to forget
480 * about this command.
483 rtn = scsi_eh_completed_normally(scmd);
484 SCSI_LOG_ERROR_RECOVERY(3,
485 printk("%s: scsi_eh_completed_normally %x\n",
499 * FIXME(eric) - we are not tracking whether we could
500 * abort a timed out command or not. not sure how
501 * we should treat them differently anyways.
503 if (shost->hostt->eh_abort_handler)
504 shost->hostt->eh_abort_handler(scmd);
512 * scsi_request_sense - Request sense data from a particular target.
513 * @scmd: SCSI cmd for request sense.
516 * Some hosts automatically obtain this information, others require
517 * that we obtain it on our own. This function will *not* return until
518 * the command either times out, or it completes.
520 static int scsi_request_sense(struct scsi_cmnd *scmd)
522 static unsigned char generic_sense[6] =
523 {REQUEST_SENSE, 0, 0, 0, 252, 0};
524 unsigned char *scsi_result;
528 memcpy(scmd->cmnd, generic_sense, sizeof(generic_sense));
530 scsi_result = kmalloc(252, GFP_ATOMIC | ((scmd->device->host->hostt->unchecked_isa_dma) ? __GFP_DMA : 0));
533 if (unlikely(!scsi_result)) {
534 printk(KERN_ERR "%s: cannot allocate scsi_result.\n",
540 * zero the sense buffer. some host adapters automatically always
541 * request sense, so it is not a good idea that
542 * scmd->request_buffer and scmd->sense_buffer point to the same
543 * address (db). 0 is not a valid sense code.
545 memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
546 memset(scsi_result, 0, 252);
548 saved_result = scmd->result;
549 scmd->request_buffer = scsi_result;
550 scmd->request_bufflen = 252;
552 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
553 scmd->sc_data_direction = DMA_FROM_DEVICE;
556 rtn = scsi_send_eh_cmnd(scmd, SENSE_TIMEOUT);
558 /* last chance to have valid sense data */
559 if(!SCSI_SENSE_VALID(scmd)) {
560 memcpy(scmd->sense_buffer, scmd->request_buffer,
561 sizeof(scmd->sense_buffer));
567 * when we eventually call scsi_finish, we really wish to complete
568 * the original request, so let's restore the original data. (db)
570 scsi_setup_cmd_retry(scmd);
571 scmd->result = saved_result;
576 * scsi_eh_finish_cmd - Handle a cmd that eh is finished with.
577 * @scmd: Original SCSI cmd that eh has finished.
578 * @done_q: Queue for processed commands.
581 * We don't want to use the normal command completion while we are are
582 * still handling errors - it may cause other commands to be queued,
583 * and that would disturb what we are doing. thus we really want to
584 * keep a list of pending commands for final completion, and once we
585 * are ready to leave error handling we handle completion for real.
587 void scsi_eh_finish_cmd(struct scsi_cmnd *scmd, struct list_head *done_q)
589 scmd->device->host->host_failed--;
593 * set this back so that the upper level can correctly free up
596 scsi_setup_cmd_retry(scmd);
597 list_move_tail(&scmd->eh_entry, done_q);
599 EXPORT_SYMBOL(scsi_eh_finish_cmd);
602 * scsi_eh_get_sense - Get device sense data.
603 * @work_q: Queue of commands to process.
604 * @done_q: Queue of proccessed commands..
607 * See if we need to request sense information. if so, then get it
608 * now, so we have a better idea of what to do.
611 * This has the unfortunate side effect that if a shost adapter does
612 * not automatically request sense information, that we end up shutting
613 * it down before we request it.
615 * All drivers should request sense information internally these days,
616 * so for now all I have to say is tough noogies if you end up in here.
618 * XXX: Long term this code should go away, but that needs an audit of
621 static int scsi_eh_get_sense(struct list_head *work_q,
622 struct list_head *done_q)
624 struct scsi_cmnd *scmd, *next;
627 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
628 if ((scmd->eh_eflags & SCSI_EH_CANCEL_CMD) ||
629 SCSI_SENSE_VALID(scmd))
632 SCSI_LOG_ERROR_RECOVERY(2, scmd_printk(KERN_INFO, scmd,
633 "%s: requesting sense\n",
635 rtn = scsi_request_sense(scmd);
639 SCSI_LOG_ERROR_RECOVERY(3, printk("sense requested for %p"
640 " result %x\n", scmd,
642 SCSI_LOG_ERROR_RECOVERY(3, scsi_print_sense("bh", scmd));
644 rtn = scsi_decide_disposition(scmd);
647 * if the result was normal, then just pass it along to the
651 /* we don't want this command reissued, just
652 * finished with the sense data, so set
653 * retries to the max allowed to ensure it
654 * won't get reissued */
655 scmd->retries = scmd->allowed;
656 else if (rtn != NEEDS_RETRY)
659 scsi_eh_finish_cmd(scmd, done_q);
662 return list_empty(work_q);
666 * scsi_try_to_abort_cmd - Ask host to abort a running command.
667 * @scmd: SCSI cmd to abort from Lower Level.
670 * This function will not return until the user's completion function
671 * has been called. there is no timeout on this operation. if the
672 * author of the low-level driver wishes this operation to be timed,
673 * they can provide this facility themselves. helper functions in
674 * scsi_error.c can be supplied to make this easier to do.
676 static int scsi_try_to_abort_cmd(struct scsi_cmnd *scmd)
678 if (!scmd->device->host->hostt->eh_abort_handler)
682 * scsi_done was called just after the command timed out and before
683 * we had a chance to process it. (db)
685 if (scmd->serial_number == 0)
687 return scmd->device->host->hostt->eh_abort_handler(scmd);
691 * scsi_eh_tur - Send TUR to device.
692 * @scmd: Scsi cmd to send TUR
695 * 0 - Device is ready. 1 - Device NOT ready.
697 static int scsi_eh_tur(struct scsi_cmnd *scmd)
699 static unsigned char tur_command[6] = {TEST_UNIT_READY, 0, 0, 0, 0, 0};
700 int retry_cnt = 1, rtn;
704 memcpy(scmd->cmnd, tur_command, sizeof(tur_command));
707 * zero the sense buffer. the scsi spec mandates that any
708 * untransferred sense data should be interpreted as being zero.
710 memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
712 saved_result = scmd->result;
713 scmd->request_buffer = NULL;
714 scmd->request_bufflen = 0;
716 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
718 scmd->sc_data_direction = DMA_NONE;
720 rtn = scsi_send_eh_cmnd(scmd, SENSE_TIMEOUT);
723 * when we eventually call scsi_finish, we really wish to complete
724 * the original request, so let's restore the original data. (db)
726 scsi_setup_cmd_retry(scmd);
727 scmd->result = saved_result;
730 * hey, we are done. let's look to see what happened.
732 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n",
733 __FUNCTION__, scmd, rtn));
736 else if (rtn == NEEDS_RETRY) {
745 * scsi_eh_abort_cmds - abort canceled commands.
746 * @shost: scsi host being recovered.
747 * @eh_done_q: list_head for processed commands.
750 * Try and see whether or not it makes sense to try and abort the
751 * running command. this only works out to be the case if we have one
752 * command that has timed out. if the command simply failed, it makes
753 * no sense to try and abort the command, since as far as the shost
754 * adapter is concerned, it isn't running.
756 static int scsi_eh_abort_cmds(struct list_head *work_q,
757 struct list_head *done_q)
759 struct scsi_cmnd *scmd, *next;
762 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
763 if (!(scmd->eh_eflags & SCSI_EH_CANCEL_CMD))
765 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting cmd:"
766 "0x%p\n", current->comm,
768 rtn = scsi_try_to_abort_cmd(scmd);
769 if (rtn == SUCCESS) {
770 scmd->eh_eflags &= ~SCSI_EH_CANCEL_CMD;
771 if (!scsi_device_online(scmd->device) ||
772 !scsi_eh_tur(scmd)) {
773 scsi_eh_finish_cmd(scmd, done_q);
777 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting"
784 return list_empty(work_q);
788 * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev
789 * @scmd: SCSI cmd used to send BDR
792 * There is no timeout for this operation. if this operation is
793 * unreliable for a given host, then the host itself needs to put a
794 * timer on it, and set the host back to a consistent state prior to
797 static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd)
801 if (!scmd->device->host->hostt->eh_device_reset_handler)
804 rtn = scmd->device->host->hostt->eh_device_reset_handler(scmd);
805 if (rtn == SUCCESS) {
806 scmd->device->was_reset = 1;
807 scmd->device->expecting_cc_ua = 1;
814 * scsi_eh_try_stu - Send START_UNIT to device.
815 * @scmd: Scsi cmd to send START_UNIT
818 * 0 - Device is ready. 1 - Device NOT ready.
820 static int scsi_eh_try_stu(struct scsi_cmnd *scmd)
822 static unsigned char stu_command[6] = {START_STOP, 0, 0, 0, 1, 0};
826 if (!scmd->device->allow_restart)
829 memcpy(scmd->cmnd, stu_command, sizeof(stu_command));
832 * zero the sense buffer. the scsi spec mandates that any
833 * untransferred sense data should be interpreted as being zero.
835 memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
837 saved_result = scmd->result;
838 scmd->request_buffer = NULL;
839 scmd->request_bufflen = 0;
841 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
843 scmd->sc_data_direction = DMA_NONE;
845 rtn = scsi_send_eh_cmnd(scmd, START_UNIT_TIMEOUT);
848 * when we eventually call scsi_finish, we really wish to complete
849 * the original request, so let's restore the original data. (db)
851 scsi_setup_cmd_retry(scmd);
852 scmd->result = saved_result;
855 * hey, we are done. let's look to see what happened.
857 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n",
858 __FUNCTION__, scmd, rtn));
865 * scsi_eh_stu - send START_UNIT if needed
866 * @shost: scsi host being recovered.
867 * @eh_done_q: list_head for processed commands.
870 * If commands are failing due to not ready, initializing command required,
871 * try revalidating the device, which will end up sending a start unit.
873 static int scsi_eh_stu(struct Scsi_Host *shost,
874 struct list_head *work_q,
875 struct list_head *done_q)
877 struct scsi_cmnd *scmd, *stu_scmd, *next;
878 struct scsi_device *sdev;
880 shost_for_each_device(sdev, shost) {
882 list_for_each_entry(scmd, work_q, eh_entry)
883 if (scmd->device == sdev && SCSI_SENSE_VALID(scmd) &&
884 scsi_check_sense(scmd) == FAILED ) {
892 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending START_UNIT to sdev:"
893 " 0x%p\n", current->comm, sdev));
895 if (!scsi_eh_try_stu(stu_scmd)) {
896 if (!scsi_device_online(sdev) ||
897 !scsi_eh_tur(stu_scmd)) {
898 list_for_each_entry_safe(scmd, next,
900 if (scmd->device == sdev)
901 scsi_eh_finish_cmd(scmd, done_q);
905 SCSI_LOG_ERROR_RECOVERY(3,
906 printk("%s: START_UNIT failed to sdev:"
907 " 0x%p\n", current->comm, sdev));
911 return list_empty(work_q);
916 * scsi_eh_bus_device_reset - send bdr if needed
917 * @shost: scsi host being recovered.
918 * @eh_done_q: list_head for processed commands.
921 * Try a bus device reset. still, look to see whether we have multiple
922 * devices that are jammed or not - if we have multiple devices, it
923 * makes no sense to try bus_device_reset - we really would need to try
924 * a bus_reset instead.
926 static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
927 struct list_head *work_q,
928 struct list_head *done_q)
930 struct scsi_cmnd *scmd, *bdr_scmd, *next;
931 struct scsi_device *sdev;
934 shost_for_each_device(sdev, shost) {
936 list_for_each_entry(scmd, work_q, eh_entry)
937 if (scmd->device == sdev) {
945 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BDR sdev:"
946 " 0x%p\n", current->comm,
948 rtn = scsi_try_bus_device_reset(bdr_scmd);
949 if (rtn == SUCCESS) {
950 if (!scsi_device_online(sdev) ||
951 !scsi_eh_tur(bdr_scmd)) {
952 list_for_each_entry_safe(scmd, next,
954 if (scmd->device == sdev)
955 scsi_eh_finish_cmd(scmd,
960 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BDR"
968 return list_empty(work_q);
972 * scsi_try_bus_reset - ask host to perform a bus reset
973 * @scmd: SCSI cmd to send bus reset.
975 static int scsi_try_bus_reset(struct scsi_cmnd *scmd)
980 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Bus RST\n",
983 if (!scmd->device->host->hostt->eh_bus_reset_handler)
986 rtn = scmd->device->host->hostt->eh_bus_reset_handler(scmd);
988 if (rtn == SUCCESS) {
989 if (!scmd->device->host->hostt->skip_settle_delay)
990 ssleep(BUS_RESET_SETTLE_TIME);
991 spin_lock_irqsave(scmd->device->host->host_lock, flags);
992 scsi_report_bus_reset(scmd->device->host,
994 spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
1001 * scsi_try_host_reset - ask host adapter to reset itself
1002 * @scmd: SCSI cmd to send hsot reset.
1004 static int scsi_try_host_reset(struct scsi_cmnd *scmd)
1006 unsigned long flags;
1009 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Host RST\n",
1012 if (!scmd->device->host->hostt->eh_host_reset_handler)
1015 rtn = scmd->device->host->hostt->eh_host_reset_handler(scmd);
1017 if (rtn == SUCCESS) {
1018 if (!scmd->device->host->hostt->skip_settle_delay)
1019 ssleep(HOST_RESET_SETTLE_TIME);
1020 spin_lock_irqsave(scmd->device->host->host_lock, flags);
1021 scsi_report_bus_reset(scmd->device->host,
1022 scmd_channel(scmd));
1023 spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
1030 * scsi_eh_bus_reset - send a bus reset
1031 * @shost: scsi host being recovered.
1032 * @eh_done_q: list_head for processed commands.
1034 static int scsi_eh_bus_reset(struct Scsi_Host *shost,
1035 struct list_head *work_q,
1036 struct list_head *done_q)
1038 struct scsi_cmnd *scmd, *chan_scmd, *next;
1039 unsigned int channel;
1043 * we really want to loop over the various channels, and do this on
1044 * a channel by channel basis. we should also check to see if any
1045 * of the failed commands are on soft_reset devices, and if so, skip
1049 for (channel = 0; channel <= shost->max_channel; channel++) {
1051 list_for_each_entry(scmd, work_q, eh_entry) {
1052 if (channel == scmd_channel(scmd)) {
1056 * FIXME add back in some support for
1057 * soft_reset devices.
1064 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BRST chan:"
1065 " %d\n", current->comm,
1067 rtn = scsi_try_bus_reset(chan_scmd);
1068 if (rtn == SUCCESS) {
1069 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1070 if (channel == scmd_channel(scmd))
1071 if (!scsi_device_online(scmd->device) ||
1073 scsi_eh_finish_cmd(scmd,
1077 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BRST"
1078 " failed chan: %d\n",
1083 return list_empty(work_q);
1087 * scsi_eh_host_reset - send a host reset
1088 * @work_q: list_head for processed commands.
1089 * @done_q: list_head for processed commands.
1091 static int scsi_eh_host_reset(struct list_head *work_q,
1092 struct list_head *done_q)
1094 struct scsi_cmnd *scmd, *next;
1097 if (!list_empty(work_q)) {
1098 scmd = list_entry(work_q->next,
1099 struct scsi_cmnd, eh_entry);
1101 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending HRST\n"
1104 rtn = scsi_try_host_reset(scmd);
1105 if (rtn == SUCCESS) {
1106 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1107 if (!scsi_device_online(scmd->device) ||
1108 (!scsi_eh_try_stu(scmd) && !scsi_eh_tur(scmd)) ||
1110 scsi_eh_finish_cmd(scmd, done_q);
1113 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: HRST"
1118 return list_empty(work_q);
1122 * scsi_eh_offline_sdevs - offline scsi devices that fail to recover
1123 * @work_q: list_head for processed commands.
1124 * @done_q: list_head for processed commands.
1127 static void scsi_eh_offline_sdevs(struct list_head *work_q,
1128 struct list_head *done_q)
1130 struct scsi_cmnd *scmd, *next;
1132 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1133 sdev_printk(KERN_INFO, scmd->device,
1134 "scsi: Device offlined - not"
1135 " ready after error recovery\n");
1136 scsi_device_set_state(scmd->device, SDEV_OFFLINE);
1137 if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD) {
1139 * FIXME: Handle lost cmds.
1142 scsi_eh_finish_cmd(scmd, done_q);
1148 * scsi_decide_disposition - Disposition a cmd on return from LLD.
1149 * @scmd: SCSI cmd to examine.
1152 * This is *only* called when we are examining the status after sending
1153 * out the actual data command. any commands that are queued for error
1154 * recovery (e.g. test_unit_ready) do *not* come through here.
1156 * When this routine returns failed, it means the error handler thread
1157 * is woken. In cases where the error code indicates an error that
1158 * doesn't require the error handler read (i.e. we don't need to
1159 * abort/reset), this function should return SUCCESS.
1161 int scsi_decide_disposition(struct scsi_cmnd *scmd)
1166 * if the device is offline, then we clearly just pass the result back
1167 * up to the top level.
1169 if (!scsi_device_online(scmd->device)) {
1170 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: device offline - report"
1177 * first check the host byte, to see if there is anything in there
1178 * that would indicate what we need to do.
1180 switch (host_byte(scmd->result)) {
1181 case DID_PASSTHROUGH:
1183 * no matter what, pass this through to the upper layer.
1184 * nuke this special code so that it looks like we are saying
1187 scmd->result &= 0xff00ffff;
1191 * looks good. drop through, and check the next byte.
1194 case DID_NO_CONNECT:
1195 case DID_BAD_TARGET:
1198 * note - this means that we just report the status back
1199 * to the top level driver, not that we actually think
1200 * that it indicates SUCCESS.
1204 * when the low level driver returns did_soft_error,
1205 * it is responsible for keeping an internal retry counter
1206 * in order to avoid endless loops (db)
1208 * actually this is a bug in this function here. we should
1209 * be mindful of the maximum number of retries specified
1210 * and not get stuck in a loop.
1212 case DID_SOFT_ERROR:
1218 return ADD_TO_MLQUEUE;
1221 if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
1222 status_byte(scmd->result) == RESERVATION_CONFLICT)
1224 * execute reservation conflict processing code
1235 * when we scan the bus, we get timeout messages for
1236 * these commands if there is no device available.
1237 * other hosts report did_no_connect for the same thing.
1239 if ((scmd->cmnd[0] == TEST_UNIT_READY ||
1240 scmd->cmnd[0] == INQUIRY)) {
1252 * next, check the message byte.
1254 if (msg_byte(scmd->result) != COMMAND_COMPLETE)
1258 * check the status byte to see if this indicates anything special.
1260 switch (status_byte(scmd->result)) {
1263 * the case of trying to send too many commands to a
1264 * tagged queueing device.
1268 * device can't talk to us at the moment. Should only
1269 * occur (SAM-3) when the task queue is empty, so will cause
1270 * the empty queue handling to trigger a stall in the
1273 return ADD_TO_MLQUEUE;
1275 case COMMAND_TERMINATED:
1278 case CHECK_CONDITION:
1279 rtn = scsi_check_sense(scmd);
1280 if (rtn == NEEDS_RETRY)
1282 /* if rtn == FAILED, we have no sense information;
1283 * returning FAILED will wake the error handler thread
1284 * to collect the sense and redo the decide
1287 case CONDITION_GOOD:
1288 case INTERMEDIATE_GOOD:
1289 case INTERMEDIATE_C_GOOD:
1292 * who knows? FIXME(eric)
1296 case RESERVATION_CONFLICT:
1297 sdev_printk(KERN_INFO, scmd->device,
1298 "reservation conflict\n");
1299 return SUCCESS; /* causes immediate i/o error */
1307 /* we requeue for retry because the error was retryable, and
1308 * the request was not marked fast fail. Note that above,
1309 * even if the request is marked fast fail, we still requeue
1310 * for queue congestion conditions (QUEUE_FULL or BUSY) */
1311 if ((++scmd->retries) <= scmd->allowed
1312 && !blk_noretry_request(scmd->request)) {
1316 * no more retries - report this one back to upper level.
1323 * scsi_eh_lock_door - Prevent medium removal for the specified device
1324 * @sdev: SCSI device to prevent medium removal
1327 * We must be called from process context; scsi_allocate_request()
1331 * We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the
1332 * head of the devices request queue, and continue.
1335 * scsi_allocate_request() may sleep waiting for existing requests to
1336 * be processed. However, since we haven't kicked off any request
1337 * processing for this host, this may deadlock.
1339 * If scsi_allocate_request() fails for what ever reason, we
1340 * completely forget to lock the door.
1342 static void scsi_eh_lock_door(struct scsi_device *sdev)
1344 unsigned char cmnd[MAX_COMMAND_SIZE];
1346 cmnd[0] = ALLOW_MEDIUM_REMOVAL;
1350 cmnd[4] = SCSI_REMOVAL_PREVENT;
1353 scsi_execute_async(sdev, cmnd, 6, DMA_NONE, NULL, 0, 0, 10 * HZ,
1354 5, NULL, NULL, GFP_KERNEL);
1359 * scsi_restart_operations - restart io operations to the specified host.
1360 * @shost: Host we are restarting.
1363 * When we entered the error handler, we blocked all further i/o to
1364 * this device. we need to 'reverse' this process.
1366 static void scsi_restart_operations(struct Scsi_Host *shost)
1368 struct scsi_device *sdev;
1369 unsigned long flags;
1372 * If the door was locked, we need to insert a door lock request
1373 * onto the head of the SCSI request queue for the device. There
1374 * is no point trying to lock the door of an off-line device.
1376 shost_for_each_device(sdev, shost) {
1377 if (scsi_device_online(sdev) && sdev->locked)
1378 scsi_eh_lock_door(sdev);
1382 * next free up anything directly waiting upon the host. this
1383 * will be requests for character device operations, and also for
1384 * ioctls to queued block devices.
1386 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: waking up host to restart\n",
1389 spin_lock_irqsave(shost->host_lock, flags);
1390 if (scsi_host_set_state(shost, SHOST_RUNNING))
1391 if (scsi_host_set_state(shost, SHOST_CANCEL))
1392 BUG_ON(scsi_host_set_state(shost, SHOST_DEL));
1393 spin_unlock_irqrestore(shost->host_lock, flags);
1395 wake_up(&shost->host_wait);
1398 * finally we need to re-initiate requests that may be pending. we will
1399 * have had everything blocked while error handling is taking place, and
1400 * now that error recovery is done, we will need to ensure that these
1401 * requests are started.
1403 scsi_run_host_queues(shost);
1407 * scsi_eh_ready_devs - check device ready state and recover if not.
1408 * @shost: host to be recovered.
1409 * @eh_done_q: list_head for processed commands.
1412 static void scsi_eh_ready_devs(struct Scsi_Host *shost,
1413 struct list_head *work_q,
1414 struct list_head *done_q)
1416 if (!scsi_eh_stu(shost, work_q, done_q))
1417 if (!scsi_eh_bus_device_reset(shost, work_q, done_q))
1418 if (!scsi_eh_bus_reset(shost, work_q, done_q))
1419 if (!scsi_eh_host_reset(work_q, done_q))
1420 scsi_eh_offline_sdevs(work_q, done_q);
1424 * scsi_eh_flush_done_q - finish processed commands or retry them.
1425 * @done_q: list_head of processed commands.
1428 void scsi_eh_flush_done_q(struct list_head *done_q)
1430 struct scsi_cmnd *scmd, *next;
1432 list_for_each_entry_safe(scmd, next, done_q, eh_entry) {
1433 list_del_init(&scmd->eh_entry);
1434 if (scsi_device_online(scmd->device) &&
1435 !blk_noretry_request(scmd->request) &&
1436 (++scmd->retries <= scmd->allowed)) {
1437 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush"
1441 scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY);
1444 * If just we got sense for the device (called
1445 * scsi_eh_get_sense), scmd->result is already
1446 * set, do not set DRIVER_TIMEOUT.
1449 scmd->result |= (DRIVER_TIMEOUT << 24);
1450 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush finish"
1452 current->comm, scmd));
1453 scsi_finish_command(scmd);
1457 EXPORT_SYMBOL(scsi_eh_flush_done_q);
1460 * scsi_unjam_host - Attempt to fix a host which has a cmd that failed.
1461 * @shost: Host to unjam.
1464 * When we come in here, we *know* that all commands on the bus have
1465 * either completed, failed or timed out. we also know that no further
1466 * commands are being sent to the host, so things are relatively quiet
1467 * and we have freedom to fiddle with things as we wish.
1469 * This is only the *default* implementation. it is possible for
1470 * individual drivers to supply their own version of this function, and
1471 * if the maintainer wishes to do this, it is strongly suggested that
1472 * this function be taken as a template and modified. this function
1473 * was designed to correctly handle problems for about 95% of the
1474 * different cases out there, and it should always provide at least a
1475 * reasonable amount of error recovery.
1477 * Any command marked 'failed' or 'timeout' must eventually have
1478 * scsi_finish_cmd() called for it. we do all of the retry stuff
1479 * here, so when we restart the host after we return it should have an
1482 static void scsi_unjam_host(struct Scsi_Host *shost)
1484 unsigned long flags;
1485 LIST_HEAD(eh_work_q);
1486 LIST_HEAD(eh_done_q);
1488 spin_lock_irqsave(shost->host_lock, flags);
1489 list_splice_init(&shost->eh_cmd_q, &eh_work_q);
1490 spin_unlock_irqrestore(shost->host_lock, flags);
1492 SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(shost, &eh_work_q));
1494 if (!scsi_eh_get_sense(&eh_work_q, &eh_done_q))
1495 if (!scsi_eh_abort_cmds(&eh_work_q, &eh_done_q))
1496 scsi_eh_ready_devs(shost, &eh_work_q, &eh_done_q);
1498 scsi_eh_flush_done_q(&eh_done_q);
1502 * scsi_error_handler - SCSI error handler thread
1503 * @data: Host for which we are running.
1506 * This is the main error handling loop. This is run as a kernel thread
1507 * for every SCSI host and handles all error handling activity.
1509 int scsi_error_handler(void *data)
1511 struct Scsi_Host *shost = data;
1513 current->flags |= PF_NOFREEZE;
1516 * We use TASK_INTERRUPTIBLE so that the thread is not
1517 * counted against the load average as a running process.
1518 * We never actually get interrupted because kthread_run
1519 * disables singal delivery for the created thread.
1521 set_current_state(TASK_INTERRUPTIBLE);
1522 while (!kthread_should_stop()) {
1523 if (shost->host_failed == 0 ||
1524 shost->host_failed != shost->host_busy) {
1525 SCSI_LOG_ERROR_RECOVERY(1,
1526 printk("Error handler scsi_eh_%d sleeping\n",
1529 set_current_state(TASK_INTERRUPTIBLE);
1533 __set_current_state(TASK_RUNNING);
1534 SCSI_LOG_ERROR_RECOVERY(1,
1535 printk("Error handler scsi_eh_%d waking up\n",
1539 * We have a host that is failing for some reason. Figure out
1540 * what we need to do to get it up and online again (if we can).
1541 * If we fail, we end up taking the thing offline.
1543 if (shost->hostt->eh_strategy_handler)
1544 shost->hostt->eh_strategy_handler(shost);
1546 scsi_unjam_host(shost);
1549 * Note - if the above fails completely, the action is to take
1550 * individual devices offline and flush the queue of any
1551 * outstanding requests that may have been pending. When we
1552 * restart, we restart any I/O to any other devices on the bus
1553 * which are still online.
1555 scsi_restart_operations(shost);
1556 set_current_state(TASK_INTERRUPTIBLE);
1558 __set_current_state(TASK_RUNNING);
1560 SCSI_LOG_ERROR_RECOVERY(1,
1561 printk("Error handler scsi_eh_%d exiting\n", shost->host_no));
1562 shost->ehandler = NULL;
1567 * Function: scsi_report_bus_reset()
1569 * Purpose: Utility function used by low-level drivers to report that
1570 * they have observed a bus reset on the bus being handled.
1572 * Arguments: shost - Host in question
1573 * channel - channel on which reset was observed.
1577 * Lock status: Host lock must be held.
1579 * Notes: This only needs to be called if the reset is one which
1580 * originates from an unknown location. Resets originated
1581 * by the mid-level itself don't need to call this, but there
1582 * should be no harm.
1584 * The main purpose of this is to make sure that a CHECK_CONDITION
1585 * is properly treated.
1587 void scsi_report_bus_reset(struct Scsi_Host *shost, int channel)
1589 struct scsi_device *sdev;
1591 __shost_for_each_device(sdev, shost) {
1592 if (channel == sdev_channel(sdev)) {
1593 sdev->was_reset = 1;
1594 sdev->expecting_cc_ua = 1;
1598 EXPORT_SYMBOL(scsi_report_bus_reset);
1601 * Function: scsi_report_device_reset()
1603 * Purpose: Utility function used by low-level drivers to report that
1604 * they have observed a device reset on the device being handled.
1606 * Arguments: shost - Host in question
1607 * channel - channel on which reset was observed
1608 * target - target on which reset was observed
1612 * Lock status: Host lock must be held
1614 * Notes: This only needs to be called if the reset is one which
1615 * originates from an unknown location. Resets originated
1616 * by the mid-level itself don't need to call this, but there
1617 * should be no harm.
1619 * The main purpose of this is to make sure that a CHECK_CONDITION
1620 * is properly treated.
1622 void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
1624 struct scsi_device *sdev;
1626 __shost_for_each_device(sdev, shost) {
1627 if (channel == sdev_channel(sdev) &&
1628 target == sdev_id(sdev)) {
1629 sdev->was_reset = 1;
1630 sdev->expecting_cc_ua = 1;
1634 EXPORT_SYMBOL(scsi_report_device_reset);
1637 scsi_reset_provider_done_command(struct scsi_cmnd *scmd)
1642 * Function: scsi_reset_provider
1644 * Purpose: Send requested reset to a bus or device at any phase.
1646 * Arguments: device - device to send reset to
1647 * flag - reset type (see scsi.h)
1649 * Returns: SUCCESS/FAILURE.
1651 * Notes: This is used by the SCSI Generic driver to provide
1652 * Bus/Device reset capability.
1655 scsi_reset_provider(struct scsi_device *dev, int flag)
1657 struct scsi_cmnd *scmd = scsi_get_command(dev, GFP_KERNEL);
1661 scmd->request = &req;
1662 memset(&scmd->eh_timeout, 0, sizeof(scmd->eh_timeout));
1663 scmd->request->rq_status = RQ_SCSI_BUSY;
1665 memset(&scmd->cmnd, '\0', sizeof(scmd->cmnd));
1667 scmd->scsi_done = scsi_reset_provider_done_command;
1669 scmd->buffer = NULL;
1671 scmd->request_buffer = NULL;
1672 scmd->request_bufflen = 0;
1676 scmd->sc_data_direction = DMA_BIDIRECTIONAL;
1677 scmd->sc_request = NULL;
1678 scmd->sc_magic = SCSI_CMND_MAGIC;
1680 init_timer(&scmd->eh_timeout);
1683 * Sometimes the command can get back into the timer chain,
1684 * so use the pid as an identifier.
1689 case SCSI_TRY_RESET_DEVICE:
1690 rtn = scsi_try_bus_device_reset(scmd);
1694 case SCSI_TRY_RESET_BUS:
1695 rtn = scsi_try_bus_reset(scmd);
1699 case SCSI_TRY_RESET_HOST:
1700 rtn = scsi_try_host_reset(scmd);
1706 scsi_next_command(scmd);
1709 EXPORT_SYMBOL(scsi_reset_provider);
1712 * scsi_normalize_sense - normalize main elements from either fixed or
1713 * descriptor sense data format into a common format.
1715 * @sense_buffer: byte array containing sense data returned by device
1716 * @sb_len: number of valid bytes in sense_buffer
1717 * @sshdr: pointer to instance of structure that common
1718 * elements are written to.
1721 * The "main elements" from sense data are: response_code, sense_key,
1722 * asc, ascq and additional_length (only for descriptor format).
1724 * Typically this function can be called after a device has
1725 * responded to a SCSI command with the CHECK_CONDITION status.
1728 * 1 if valid sense data information found, else 0;
1730 int scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
1731 struct scsi_sense_hdr *sshdr)
1733 if (!sense_buffer || !sb_len)
1736 memset(sshdr, 0, sizeof(struct scsi_sense_hdr));
1738 sshdr->response_code = (sense_buffer[0] & 0x7f);
1740 if (!scsi_sense_valid(sshdr))
1743 if (sshdr->response_code >= 0x72) {
1748 sshdr->sense_key = (sense_buffer[1] & 0xf);
1750 sshdr->asc = sense_buffer[2];
1752 sshdr->ascq = sense_buffer[3];
1754 sshdr->additional_length = sense_buffer[7];
1760 sshdr->sense_key = (sense_buffer[2] & 0xf);
1762 sb_len = (sb_len < (sense_buffer[7] + 8)) ?
1763 sb_len : (sense_buffer[7] + 8);
1765 sshdr->asc = sense_buffer[12];
1767 sshdr->ascq = sense_buffer[13];
1773 EXPORT_SYMBOL(scsi_normalize_sense);
1775 int scsi_request_normalize_sense(struct scsi_request *sreq,
1776 struct scsi_sense_hdr *sshdr)
1778 return scsi_normalize_sense(sreq->sr_sense_buffer,
1779 sizeof(sreq->sr_sense_buffer), sshdr);
1781 EXPORT_SYMBOL(scsi_request_normalize_sense);
1783 int scsi_command_normalize_sense(struct scsi_cmnd *cmd,
1784 struct scsi_sense_hdr *sshdr)
1786 return scsi_normalize_sense(cmd->sense_buffer,
1787 sizeof(cmd->sense_buffer), sshdr);
1789 EXPORT_SYMBOL(scsi_command_normalize_sense);
1792 * scsi_sense_desc_find - search for a given descriptor type in
1793 * descriptor sense data format.
1795 * @sense_buffer: byte array of descriptor format sense data
1796 * @sb_len: number of valid bytes in sense_buffer
1797 * @desc_type: value of descriptor type to find
1798 * (e.g. 0 -> information)
1801 * only valid when sense data is in descriptor format
1804 * pointer to start of (first) descriptor if found else NULL
1806 const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
1809 int add_sen_len, add_len, desc_len, k;
1812 if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7])))
1814 if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73))
1816 add_sen_len = (add_sen_len < (sb_len - 8)) ?
1817 add_sen_len : (sb_len - 8);
1818 descp = &sense_buffer[8];
1819 for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) {
1821 add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
1822 desc_len = add_len + 2;
1823 if (descp[0] == desc_type)
1825 if (add_len < 0) // short descriptor ??
1830 EXPORT_SYMBOL(scsi_sense_desc_find);
1833 * scsi_get_sense_info_fld - attempts to get information field from
1834 * sense data (either fixed or descriptor format)
1836 * @sense_buffer: byte array of sense data
1837 * @sb_len: number of valid bytes in sense_buffer
1838 * @info_out: pointer to 64 integer where 8 or 4 byte information
1839 * field will be placed if found.
1842 * 1 if information field found, 0 if not found.
1844 int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len,
1853 switch (sense_buffer[0] & 0x7f) {
1856 if (sense_buffer[0] & 0x80) {
1857 *info_out = (sense_buffer[3] << 24) +
1858 (sense_buffer[4] << 16) +
1859 (sense_buffer[5] << 8) + sense_buffer[6];
1865 ucp = scsi_sense_desc_find(sense_buffer, sb_len,
1867 if (ucp && (0xa == ucp[1])) {
1869 for (j = 0; j < 8; ++j) {
1882 EXPORT_SYMBOL(scsi_get_sense_info_fld);