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_times_out - Timeout function for normal scsi commands.
116 * @req: request that is timing out.
119 * We do not need to lock this. There is the potential for a race
120 * only in that the normal completion handling might run, but if the
121 * normal completion function determines that the timer has already
122 * fired, then it mustn't do anything.
124 enum blk_eh_timer_return scsi_times_out(struct request *req)
126 struct scsi_cmnd *scmd = req->special;
127 enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
128 enum blk_eh_timer_return rtn = BLK_EH_NOT_HANDLED;
130 scsi_log_completion(scmd, TIMEOUT_ERROR);
132 if (scmd->device->host->transportt->eh_timed_out)
133 eh_timed_out = scmd->device->host->transportt->eh_timed_out;
134 else if (scmd->device->host->hostt->eh_timed_out)
135 eh_timed_out = scmd->device->host->hostt->eh_timed_out;
140 rtn = eh_timed_out(scmd);
142 case BLK_EH_NOT_HANDLED:
148 if (unlikely(!scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD))) {
149 scmd->result |= DID_TIME_OUT << 16;
150 return BLK_EH_HANDLED;
153 return BLK_EH_NOT_HANDLED;
157 * scsi_block_when_processing_errors - Prevent cmds from being queued.
158 * @sdev: Device on which we are performing recovery.
161 * We block until the host is out of error recovery, and then check to
162 * see whether the host or the device is offline.
165 * 0 when dev was taken offline by error recovery. 1 OK to proceed.
167 int scsi_block_when_processing_errors(struct scsi_device *sdev)
171 wait_event(sdev->host->host_wait, !scsi_host_in_recovery(sdev->host));
173 online = scsi_device_online(sdev);
175 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: rtn: %d\n", __func__,
180 EXPORT_SYMBOL(scsi_block_when_processing_errors);
182 #ifdef CONFIG_SCSI_LOGGING
184 * scsi_eh_prt_fail_stats - Log info on failures.
185 * @shost: scsi host being recovered.
186 * @work_q: Queue of scsi cmds to process.
188 static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost,
189 struct list_head *work_q)
191 struct scsi_cmnd *scmd;
192 struct scsi_device *sdev;
193 int total_failures = 0;
196 int devices_failed = 0;
198 shost_for_each_device(sdev, shost) {
199 list_for_each_entry(scmd, work_q, eh_entry) {
200 if (scmd->device == sdev) {
202 if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD)
209 if (cmd_cancel || cmd_failed) {
210 SCSI_LOG_ERROR_RECOVERY(3,
211 sdev_printk(KERN_INFO, sdev,
212 "%s: cmds failed: %d, cancel: %d\n",
213 __func__, cmd_failed,
221 SCSI_LOG_ERROR_RECOVERY(2, printk("Total of %d commands on %d"
222 " devices require eh work\n",
223 total_failures, devices_failed));
228 * scsi_check_sense - Examine scsi cmd sense
229 * @scmd: Cmd to have sense checked.
232 * SUCCESS or FAILED or NEEDS_RETRY
235 * When a deferred error is detected the current command has
236 * not been executed and needs retrying.
238 static int scsi_check_sense(struct scsi_cmnd *scmd)
240 struct scsi_device *sdev = scmd->device;
241 struct scsi_sense_hdr sshdr;
243 if (! scsi_command_normalize_sense(scmd, &sshdr))
244 return FAILED; /* no valid sense data */
246 if (scsi_sense_is_deferred(&sshdr))
249 if (sdev->scsi_dh_data && sdev->scsi_dh_data->scsi_dh &&
250 sdev->scsi_dh_data->scsi_dh->check_sense) {
253 rc = sdev->scsi_dh_data->scsi_dh->check_sense(sdev, &sshdr);
254 if (rc != SCSI_RETURN_NOT_HANDLED)
256 /* handler does not care. Drop down to default handling */
260 * Previous logic looked for FILEMARK, EOM or ILI which are
261 * mainly associated with tapes and returned SUCCESS.
263 if (sshdr.response_code == 0x70) {
265 if (scmd->sense_buffer[2] & 0xe0)
269 * descriptor format: look for "stream commands sense data
270 * descriptor" (see SSC-3). Assume single sense data
271 * descriptor. Ignore ILI from SBC-2 READ LONG and WRITE LONG.
273 if ((sshdr.additional_length > 3) &&
274 (scmd->sense_buffer[8] == 0x4) &&
275 (scmd->sense_buffer[11] & 0xe0))
279 switch (sshdr.sense_key) {
282 case RECOVERED_ERROR:
283 return /* soft_error */ SUCCESS;
285 case ABORTED_COMMAND:
286 if (sshdr.asc == 0x10) /* DIF */
293 * if we are expecting a cc/ua because of a bus reset that we
294 * performed, treat this just as a retry. otherwise this is
295 * information that we should pass up to the upper-level driver
296 * so that we can deal with it there.
298 if (scmd->device->expecting_cc_ua) {
299 scmd->device->expecting_cc_ua = 0;
303 * if the device is in the process of becoming ready, we
306 if ((sshdr.asc == 0x04) && (sshdr.ascq == 0x01))
309 * if the device is not started, we need to wake
310 * the error handler to start the motor
312 if (scmd->device->allow_restart &&
313 (sshdr.asc == 0x04) && (sshdr.ascq == 0x02))
317 /* these three are not supported */
319 case VOLUME_OVERFLOW:
324 if (sshdr.asc == 0x11 || /* UNRECOVERED READ ERR */
325 sshdr.asc == 0x13 || /* AMNF DATA FIELD */
326 sshdr.asc == 0x14) { /* RECORD NOT FOUND */
332 if (scmd->device->retry_hwerror)
333 return ADD_TO_MLQUEUE;
337 case ILLEGAL_REQUEST:
346 * scsi_eh_completed_normally - Disposition a eh cmd on return from LLD.
347 * @scmd: SCSI cmd to examine.
350 * This is *only* called when we are examining the status of commands
351 * queued during error recovery. the main difference here is that we
352 * don't allow for the possibility of retries here, and we are a lot
353 * more restrictive about what we consider acceptable.
355 static int scsi_eh_completed_normally(struct scsi_cmnd *scmd)
358 * first check the host byte, to see if there is anything in there
359 * that would indicate what we need to do.
361 if (host_byte(scmd->result) == DID_RESET) {
363 * rats. we are already in the error handler, so we now
364 * get to try and figure out what to do next. if the sense
365 * is valid, we have a pretty good idea of what to do.
366 * if not, we mark it as FAILED.
368 return scsi_check_sense(scmd);
370 if (host_byte(scmd->result) != DID_OK)
374 * next, check the message byte.
376 if (msg_byte(scmd->result) != COMMAND_COMPLETE)
380 * now, check the status byte to see if this indicates
383 switch (status_byte(scmd->result)) {
385 case COMMAND_TERMINATED:
387 case CHECK_CONDITION:
388 return scsi_check_sense(scmd);
390 case INTERMEDIATE_GOOD:
391 case INTERMEDIATE_C_GOOD:
393 * who knows? FIXME(eric)
398 case RESERVATION_CONFLICT:
406 * scsi_eh_done - Completion function for error handling.
407 * @scmd: Cmd that is done.
409 static void scsi_eh_done(struct scsi_cmnd *scmd)
411 struct completion *eh_action;
413 SCSI_LOG_ERROR_RECOVERY(3,
414 printk("%s scmd: %p result: %x\n",
415 __func__, scmd, scmd->result));
417 eh_action = scmd->device->host->eh_action;
423 * scsi_try_host_reset - ask host adapter to reset itself
424 * @scmd: SCSI cmd to send hsot reset.
426 static int scsi_try_host_reset(struct scsi_cmnd *scmd)
431 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Host RST\n",
434 if (!scmd->device->host->hostt->eh_host_reset_handler)
437 rtn = scmd->device->host->hostt->eh_host_reset_handler(scmd);
439 if (rtn == SUCCESS) {
440 if (!scmd->device->host->hostt->skip_settle_delay)
441 ssleep(HOST_RESET_SETTLE_TIME);
442 spin_lock_irqsave(scmd->device->host->host_lock, flags);
443 scsi_report_bus_reset(scmd->device->host,
445 spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
452 * scsi_try_bus_reset - ask host to perform a bus reset
453 * @scmd: SCSI cmd to send bus reset.
455 static int scsi_try_bus_reset(struct scsi_cmnd *scmd)
460 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Bus RST\n",
463 if (!scmd->device->host->hostt->eh_bus_reset_handler)
466 rtn = scmd->device->host->hostt->eh_bus_reset_handler(scmd);
468 if (rtn == SUCCESS) {
469 if (!scmd->device->host->hostt->skip_settle_delay)
470 ssleep(BUS_RESET_SETTLE_TIME);
471 spin_lock_irqsave(scmd->device->host->host_lock, flags);
472 scsi_report_bus_reset(scmd->device->host,
474 spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
480 static void __scsi_report_device_reset(struct scsi_device *sdev, void *data)
483 sdev->expecting_cc_ua = 1;
487 * scsi_try_target_reset - Ask host to perform a target reset
488 * @scmd: SCSI cmd used to send a target reset
491 * There is no timeout for this operation. if this operation is
492 * unreliable for a given host, then the host itself needs to put a
493 * timer on it, and set the host back to a consistent state prior to
496 static int scsi_try_target_reset(struct scsi_cmnd *scmd)
501 if (!scmd->device->host->hostt->eh_target_reset_handler)
504 rtn = scmd->device->host->hostt->eh_target_reset_handler(scmd);
505 if (rtn == SUCCESS) {
506 spin_lock_irqsave(scmd->device->host->host_lock, flags);
507 __starget_for_each_device(scsi_target(scmd->device), NULL,
508 __scsi_report_device_reset);
509 spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
516 * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev
517 * @scmd: SCSI cmd used to send BDR
520 * There is no timeout for this operation. if this operation is
521 * unreliable for a given host, then the host itself needs to put a
522 * timer on it, and set the host back to a consistent state prior to
525 static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd)
529 if (!scmd->device->host->hostt->eh_device_reset_handler)
532 rtn = scmd->device->host->hostt->eh_device_reset_handler(scmd);
534 __scsi_report_device_reset(scmd->device, NULL);
538 static int __scsi_try_to_abort_cmd(struct scsi_cmnd *scmd)
540 if (!scmd->device->host->hostt->eh_abort_handler)
543 return scmd->device->host->hostt->eh_abort_handler(scmd);
547 * scsi_try_to_abort_cmd - Ask host to abort a running command.
548 * @scmd: SCSI cmd to abort from Lower Level.
551 * This function will not return until the user's completion function
552 * has been called. there is no timeout on this operation. if the
553 * author of the low-level driver wishes this operation to be timed,
554 * they can provide this facility themselves. helper functions in
555 * scsi_error.c can be supplied to make this easier to do.
557 static int scsi_try_to_abort_cmd(struct scsi_cmnd *scmd)
560 * scsi_done was called just after the command timed out and before
561 * we had a chance to process it. (db)
563 if (scmd->serial_number == 0)
565 return __scsi_try_to_abort_cmd(scmd);
568 static void scsi_abort_eh_cmnd(struct scsi_cmnd *scmd)
570 if (__scsi_try_to_abort_cmd(scmd) != SUCCESS)
571 if (scsi_try_bus_device_reset(scmd) != SUCCESS)
572 if (scsi_try_target_reset(scmd) != SUCCESS)
573 if (scsi_try_bus_reset(scmd) != SUCCESS)
574 scsi_try_host_reset(scmd);
578 * scsi_eh_prep_cmnd - Save a scsi command info as part of error recory
579 * @scmd: SCSI command structure to hijack
580 * @ses: structure to save restore information
581 * @cmnd: CDB to send. Can be NULL if no new cmnd is needed
582 * @cmnd_size: size in bytes of @cmnd (must be <= BLK_MAX_CDB)
583 * @sense_bytes: size of sense data to copy. or 0 (if != 0 @cmnd is ignored)
585 * This function is used to save a scsi command information before re-execution
586 * as part of the error recovery process. If @sense_bytes is 0 the command
587 * sent must be one that does not transfer any data. If @sense_bytes != 0
588 * @cmnd is ignored and this functions sets up a REQUEST_SENSE command
589 * and cmnd buffers to read @sense_bytes into @scmd->sense_buffer.
591 void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd, struct scsi_eh_save *ses,
592 unsigned char *cmnd, int cmnd_size, unsigned sense_bytes)
594 struct scsi_device *sdev = scmd->device;
597 * We need saved copies of a number of fields - this is because
598 * error handling may need to overwrite these with different values
599 * to run different commands, and once error handling is complete,
600 * we will need to restore these values prior to running the actual
603 ses->cmd_len = scmd->cmd_len;
604 ses->cmnd = scmd->cmnd;
605 ses->data_direction = scmd->sc_data_direction;
606 ses->sdb = scmd->sdb;
607 ses->next_rq = scmd->request->next_rq;
608 ses->result = scmd->result;
609 ses->underflow = scmd->underflow;
610 ses->prot_op = scmd->prot_op;
612 scmd->prot_op = SCSI_PROT_NORMAL;
613 scmd->cmnd = ses->eh_cmnd;
614 memset(scmd->cmnd, 0, BLK_MAX_CDB);
615 memset(&scmd->sdb, 0, sizeof(scmd->sdb));
616 scmd->request->next_rq = NULL;
619 scmd->sdb.length = min_t(unsigned, SCSI_SENSE_BUFFERSIZE,
621 sg_init_one(&ses->sense_sgl, scmd->sense_buffer,
623 scmd->sdb.table.sgl = &ses->sense_sgl;
624 scmd->sc_data_direction = DMA_FROM_DEVICE;
625 scmd->sdb.table.nents = 1;
626 scmd->cmnd[0] = REQUEST_SENSE;
627 scmd->cmnd[4] = scmd->sdb.length;
628 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
630 scmd->sc_data_direction = DMA_NONE;
632 BUG_ON(cmnd_size > BLK_MAX_CDB);
633 memcpy(scmd->cmnd, cmnd, cmnd_size);
634 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
640 if (sdev->scsi_level <= SCSI_2 && sdev->scsi_level != SCSI_UNKNOWN)
641 scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) |
642 (sdev->lun << 5 & 0xe0);
645 * Zero the sense buffer. The scsi spec mandates that any
646 * untransferred sense data should be interpreted as being zero.
648 memset(scmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
650 EXPORT_SYMBOL(scsi_eh_prep_cmnd);
653 * scsi_eh_restore_cmnd - Restore a scsi command info as part of error recory
654 * @scmd: SCSI command structure to restore
655 * @ses: saved information from a coresponding call to scsi_prep_eh_cmnd
657 * Undo any damage done by above scsi_prep_eh_cmnd().
659 void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd, struct scsi_eh_save *ses)
662 * Restore original data
664 scmd->cmd_len = ses->cmd_len;
665 scmd->cmnd = ses->cmnd;
666 scmd->sc_data_direction = ses->data_direction;
667 scmd->sdb = ses->sdb;
668 scmd->request->next_rq = ses->next_rq;
669 scmd->result = ses->result;
670 scmd->underflow = ses->underflow;
671 scmd->prot_op = ses->prot_op;
673 EXPORT_SYMBOL(scsi_eh_restore_cmnd);
676 * scsi_send_eh_cmnd - submit a scsi command as part of error recory
677 * @scmd: SCSI command structure to hijack
679 * @cmnd_size: size in bytes of @cmnd
680 * @timeout: timeout for this request
681 * @sense_bytes: size of sense data to copy or 0
683 * This function is used to send a scsi command down to a target device
684 * as part of the error recovery process. See also scsi_eh_prep_cmnd() above.
687 * SUCCESS or FAILED or NEEDS_RETRY
689 static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
690 int cmnd_size, int timeout, unsigned sense_bytes)
692 struct scsi_device *sdev = scmd->device;
693 struct Scsi_Host *shost = sdev->host;
694 DECLARE_COMPLETION_ONSTACK(done);
695 unsigned long timeleft;
697 struct scsi_eh_save ses;
700 scsi_eh_prep_cmnd(scmd, &ses, cmnd, cmnd_size, sense_bytes);
701 shost->eh_action = &done;
703 spin_lock_irqsave(shost->host_lock, flags);
705 shost->hostt->queuecommand(scmd, scsi_eh_done);
706 spin_unlock_irqrestore(shost->host_lock, flags);
708 timeleft = wait_for_completion_timeout(&done, timeout);
710 shost->eh_action = NULL;
712 scsi_log_completion(scmd, SUCCESS);
714 SCSI_LOG_ERROR_RECOVERY(3,
715 printk("%s: scmd: %p, timeleft: %ld\n",
716 __func__, scmd, timeleft));
719 * If there is time left scsi_eh_done got called, and we will
720 * examine the actual status codes to see whether the command
721 * actually did complete normally, else tell the host to forget
722 * about this command.
725 rtn = scsi_eh_completed_normally(scmd);
726 SCSI_LOG_ERROR_RECOVERY(3,
727 printk("%s: scsi_eh_completed_normally %x\n",
740 scsi_abort_eh_cmnd(scmd);
744 scsi_eh_restore_cmnd(scmd, &ses);
749 * scsi_request_sense - Request sense data from a particular target.
750 * @scmd: SCSI cmd for request sense.
753 * Some hosts automatically obtain this information, others require
754 * that we obtain it on our own. This function will *not* return until
755 * the command either times out, or it completes.
757 static int scsi_request_sense(struct scsi_cmnd *scmd)
759 return scsi_send_eh_cmnd(scmd, NULL, 0, SENSE_TIMEOUT, ~0);
763 * scsi_eh_finish_cmd - Handle a cmd that eh is finished with.
764 * @scmd: Original SCSI cmd that eh has finished.
765 * @done_q: Queue for processed commands.
768 * We don't want to use the normal command completion while we are are
769 * still handling errors - it may cause other commands to be queued,
770 * and that would disturb what we are doing. Thus we really want to
771 * keep a list of pending commands for final completion, and once we
772 * are ready to leave error handling we handle completion for real.
774 void scsi_eh_finish_cmd(struct scsi_cmnd *scmd, struct list_head *done_q)
776 scmd->device->host->host_failed--;
778 list_move_tail(&scmd->eh_entry, done_q);
780 EXPORT_SYMBOL(scsi_eh_finish_cmd);
783 * scsi_eh_get_sense - Get device sense data.
784 * @work_q: Queue of commands to process.
785 * @done_q: Queue of processed commands.
788 * See if we need to request sense information. if so, then get it
789 * now, so we have a better idea of what to do.
792 * This has the unfortunate side effect that if a shost adapter does
793 * not automatically request sense information, we end up shutting
794 * it down before we request it.
796 * All drivers should request sense information internally these days,
797 * so for now all I have to say is tough noogies if you end up in here.
799 * XXX: Long term this code should go away, but that needs an audit of
802 int scsi_eh_get_sense(struct list_head *work_q,
803 struct list_head *done_q)
805 struct scsi_cmnd *scmd, *next;
808 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
809 if ((scmd->eh_eflags & SCSI_EH_CANCEL_CMD) ||
810 SCSI_SENSE_VALID(scmd))
813 SCSI_LOG_ERROR_RECOVERY(2, scmd_printk(KERN_INFO, scmd,
814 "%s: requesting sense\n",
816 rtn = scsi_request_sense(scmd);
820 SCSI_LOG_ERROR_RECOVERY(3, printk("sense requested for %p"
821 " result %x\n", scmd,
823 SCSI_LOG_ERROR_RECOVERY(3, scsi_print_sense("bh", scmd));
825 rtn = scsi_decide_disposition(scmd);
828 * if the result was normal, then just pass it along to the
832 /* we don't want this command reissued, just
833 * finished with the sense data, so set
834 * retries to the max allowed to ensure it
835 * won't get reissued */
836 scmd->retries = scmd->allowed;
837 else if (rtn != NEEDS_RETRY)
840 scsi_eh_finish_cmd(scmd, done_q);
843 return list_empty(work_q);
845 EXPORT_SYMBOL_GPL(scsi_eh_get_sense);
848 * scsi_eh_tur - Send TUR to device.
849 * @scmd: &scsi_cmnd to send TUR
852 * 0 - Device is ready. 1 - Device NOT ready.
854 static int scsi_eh_tur(struct scsi_cmnd *scmd)
856 static unsigned char tur_command[6] = {TEST_UNIT_READY, 0, 0, 0, 0, 0};
857 int retry_cnt = 1, rtn;
860 rtn = scsi_send_eh_cmnd(scmd, tur_command, 6, SENSE_TIMEOUT, 0);
862 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n",
863 __func__, scmd, rtn));
878 * scsi_eh_abort_cmds - abort pending commands.
879 * @work_q: &list_head for pending commands.
880 * @done_q: &list_head for processed commands.
883 * Try and see whether or not it makes sense to try and abort the
884 * running command. This only works out to be the case if we have one
885 * command that has timed out. If the command simply failed, it makes
886 * no sense to try and abort the command, since as far as the shost
887 * adapter is concerned, it isn't running.
889 static int scsi_eh_abort_cmds(struct list_head *work_q,
890 struct list_head *done_q)
892 struct scsi_cmnd *scmd, *next;
895 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
896 if (!(scmd->eh_eflags & SCSI_EH_CANCEL_CMD))
898 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting cmd:"
899 "0x%p\n", current->comm,
901 rtn = scsi_try_to_abort_cmd(scmd);
902 if (rtn == SUCCESS) {
903 scmd->eh_eflags &= ~SCSI_EH_CANCEL_CMD;
904 if (!scsi_device_online(scmd->device) ||
905 !scsi_eh_tur(scmd)) {
906 scsi_eh_finish_cmd(scmd, done_q);
910 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting"
917 return list_empty(work_q);
921 * scsi_eh_try_stu - Send START_UNIT to device.
922 * @scmd: &scsi_cmnd to send START_UNIT
925 * 0 - Device is ready. 1 - Device NOT ready.
927 static int scsi_eh_try_stu(struct scsi_cmnd *scmd)
929 static unsigned char stu_command[6] = {START_STOP, 0, 0, 0, 1, 0};
931 if (scmd->device->allow_restart) {
932 int i, rtn = NEEDS_RETRY;
934 for (i = 0; rtn == NEEDS_RETRY && i < 2; i++)
935 rtn = scsi_send_eh_cmnd(scmd, stu_command, 6,
936 scmd->device->timeout, 0);
946 * scsi_eh_stu - send START_UNIT if needed
947 * @shost: &scsi host being recovered.
948 * @work_q: &list_head for pending commands.
949 * @done_q: &list_head for processed commands.
952 * If commands are failing due to not ready, initializing command required,
953 * try revalidating the device, which will end up sending a start unit.
955 static int scsi_eh_stu(struct Scsi_Host *shost,
956 struct list_head *work_q,
957 struct list_head *done_q)
959 struct scsi_cmnd *scmd, *stu_scmd, *next;
960 struct scsi_device *sdev;
962 shost_for_each_device(sdev, shost) {
964 list_for_each_entry(scmd, work_q, eh_entry)
965 if (scmd->device == sdev && SCSI_SENSE_VALID(scmd) &&
966 scsi_check_sense(scmd) == FAILED ) {
974 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending START_UNIT to sdev:"
975 " 0x%p\n", current->comm, sdev));
977 if (!scsi_eh_try_stu(stu_scmd)) {
978 if (!scsi_device_online(sdev) ||
979 !scsi_eh_tur(stu_scmd)) {
980 list_for_each_entry_safe(scmd, next,
982 if (scmd->device == sdev)
983 scsi_eh_finish_cmd(scmd, done_q);
987 SCSI_LOG_ERROR_RECOVERY(3,
988 printk("%s: START_UNIT failed to sdev:"
989 " 0x%p\n", current->comm, sdev));
993 return list_empty(work_q);
998 * scsi_eh_bus_device_reset - send bdr if needed
999 * @shost: scsi host being recovered.
1000 * @work_q: &list_head for pending commands.
1001 * @done_q: &list_head for processed commands.
1004 * Try a bus device reset. Still, look to see whether we have multiple
1005 * devices that are jammed or not - if we have multiple devices, it
1006 * makes no sense to try bus_device_reset - we really would need to try
1007 * a bus_reset instead.
1009 static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
1010 struct list_head *work_q,
1011 struct list_head *done_q)
1013 struct scsi_cmnd *scmd, *bdr_scmd, *next;
1014 struct scsi_device *sdev;
1017 shost_for_each_device(sdev, shost) {
1019 list_for_each_entry(scmd, work_q, eh_entry)
1020 if (scmd->device == sdev) {
1028 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BDR sdev:"
1029 " 0x%p\n", current->comm,
1031 rtn = scsi_try_bus_device_reset(bdr_scmd);
1032 if (rtn == SUCCESS) {
1033 if (!scsi_device_online(sdev) ||
1034 !scsi_eh_tur(bdr_scmd)) {
1035 list_for_each_entry_safe(scmd, next,
1037 if (scmd->device == sdev)
1038 scsi_eh_finish_cmd(scmd,
1043 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BDR"
1051 return list_empty(work_q);
1055 * scsi_eh_target_reset - send target reset if needed
1056 * @shost: scsi host being recovered.
1057 * @work_q: &list_head for pending commands.
1058 * @done_q: &list_head for processed commands.
1061 * Try a target reset.
1063 static int scsi_eh_target_reset(struct Scsi_Host *shost,
1064 struct list_head *work_q,
1065 struct list_head *done_q)
1067 struct scsi_cmnd *scmd, *tgtr_scmd, *next;
1071 for (id = 0; id <= shost->max_id; id++) {
1073 list_for_each_entry(scmd, work_q, eh_entry) {
1074 if (id == scmd_id(scmd)) {
1082 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending target reset "
1084 current->comm, id));
1085 rtn = scsi_try_target_reset(tgtr_scmd);
1086 if (rtn == SUCCESS) {
1087 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1088 if (id == scmd_id(scmd))
1089 if (!scsi_device_online(scmd->device) ||
1090 !scsi_eh_tur(tgtr_scmd))
1091 scsi_eh_finish_cmd(scmd,
1095 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Target reset"
1098 current->comm, id));
1101 return list_empty(work_q);
1105 * scsi_eh_bus_reset - send a bus reset
1106 * @shost: &scsi host being recovered.
1107 * @work_q: &list_head for pending commands.
1108 * @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 scsi_cmnd *scmd, *chan_scmd, *next;
1115 unsigned int channel;
1119 * we really want to loop over the various channels, and do this on
1120 * a channel by channel basis. we should also check to see if any
1121 * of the failed commands are on soft_reset devices, and if so, skip
1125 for (channel = 0; channel <= shost->max_channel; channel++) {
1127 list_for_each_entry(scmd, work_q, eh_entry) {
1128 if (channel == scmd_channel(scmd)) {
1132 * FIXME add back in some support for
1133 * soft_reset devices.
1140 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BRST chan:"
1141 " %d\n", current->comm,
1143 rtn = scsi_try_bus_reset(chan_scmd);
1144 if (rtn == SUCCESS) {
1145 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1146 if (channel == scmd_channel(scmd))
1147 if (!scsi_device_online(scmd->device) ||
1149 scsi_eh_finish_cmd(scmd,
1153 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BRST"
1154 " failed chan: %d\n",
1159 return list_empty(work_q);
1163 * scsi_eh_host_reset - send a host reset
1164 * @work_q: list_head for processed commands.
1165 * @done_q: list_head for processed commands.
1167 static int scsi_eh_host_reset(struct list_head *work_q,
1168 struct list_head *done_q)
1170 struct scsi_cmnd *scmd, *next;
1173 if (!list_empty(work_q)) {
1174 scmd = list_entry(work_q->next,
1175 struct scsi_cmnd, eh_entry);
1177 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending HRST\n"
1180 rtn = scsi_try_host_reset(scmd);
1181 if (rtn == SUCCESS) {
1182 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1183 if (!scsi_device_online(scmd->device) ||
1184 (!scsi_eh_try_stu(scmd) && !scsi_eh_tur(scmd)) ||
1186 scsi_eh_finish_cmd(scmd, done_q);
1189 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: HRST"
1194 return list_empty(work_q);
1198 * scsi_eh_offline_sdevs - offline scsi devices that fail to recover
1199 * @work_q: list_head for processed commands.
1200 * @done_q: list_head for processed commands.
1202 static void scsi_eh_offline_sdevs(struct list_head *work_q,
1203 struct list_head *done_q)
1205 struct scsi_cmnd *scmd, *next;
1207 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1208 sdev_printk(KERN_INFO, scmd->device, "Device offlined - "
1209 "not ready after error recovery\n");
1210 scsi_device_set_state(scmd->device, SDEV_OFFLINE);
1211 if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD) {
1213 * FIXME: Handle lost cmds.
1216 scsi_eh_finish_cmd(scmd, done_q);
1222 * scsi_decide_disposition - Disposition a cmd on return from LLD.
1223 * @scmd: SCSI cmd to examine.
1226 * This is *only* called when we are examining the status after sending
1227 * out the actual data command. any commands that are queued for error
1228 * recovery (e.g. test_unit_ready) do *not* come through here.
1230 * When this routine returns failed, it means the error handler thread
1231 * is woken. In cases where the error code indicates an error that
1232 * doesn't require the error handler read (i.e. we don't need to
1233 * abort/reset), this function should return SUCCESS.
1235 int scsi_decide_disposition(struct scsi_cmnd *scmd)
1240 * if the device is offline, then we clearly just pass the result back
1241 * up to the top level.
1243 if (!scsi_device_online(scmd->device)) {
1244 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: device offline - report"
1251 * first check the host byte, to see if there is anything in there
1252 * that would indicate what we need to do.
1254 switch (host_byte(scmd->result)) {
1255 case DID_PASSTHROUGH:
1257 * no matter what, pass this through to the upper layer.
1258 * nuke this special code so that it looks like we are saying
1261 scmd->result &= 0xff00ffff;
1265 * looks good. drop through, and check the next byte.
1268 case DID_NO_CONNECT:
1269 case DID_BAD_TARGET:
1272 * note - this means that we just report the status back
1273 * to the top level driver, not that we actually think
1274 * that it indicates SUCCESS.
1278 * when the low level driver returns did_soft_error,
1279 * it is responsible for keeping an internal retry counter
1280 * in order to avoid endless loops (db)
1282 * actually this is a bug in this function here. we should
1283 * be mindful of the maximum number of retries specified
1284 * and not get stuck in a loop.
1286 case DID_SOFT_ERROR:
1292 return ADD_TO_MLQUEUE;
1295 if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
1296 status_byte(scmd->result) == RESERVATION_CONFLICT)
1298 * execute reservation conflict processing code
1309 * when we scan the bus, we get timeout messages for
1310 * these commands if there is no device available.
1311 * other hosts report did_no_connect for the same thing.
1313 if ((scmd->cmnd[0] == TEST_UNIT_READY ||
1314 scmd->cmnd[0] == INQUIRY)) {
1326 * next, check the message byte.
1328 if (msg_byte(scmd->result) != COMMAND_COMPLETE)
1332 * check the status byte to see if this indicates anything special.
1334 switch (status_byte(scmd->result)) {
1337 * the case of trying to send too many commands to a
1338 * tagged queueing device.
1342 * device can't talk to us at the moment. Should only
1343 * occur (SAM-3) when the task queue is empty, so will cause
1344 * the empty queue handling to trigger a stall in the
1347 return ADD_TO_MLQUEUE;
1349 case COMMAND_TERMINATED:
1352 case CHECK_CONDITION:
1353 rtn = scsi_check_sense(scmd);
1354 if (rtn == NEEDS_RETRY)
1356 /* if rtn == FAILED, we have no sense information;
1357 * returning FAILED will wake the error handler thread
1358 * to collect the sense and redo the decide
1361 case CONDITION_GOOD:
1362 case INTERMEDIATE_GOOD:
1363 case INTERMEDIATE_C_GOOD:
1366 * who knows? FIXME(eric)
1370 case RESERVATION_CONFLICT:
1371 sdev_printk(KERN_INFO, scmd->device,
1372 "reservation conflict\n");
1373 return SUCCESS; /* causes immediate i/o error */
1381 /* we requeue for retry because the error was retryable, and
1382 * the request was not marked fast fail. Note that above,
1383 * even if the request is marked fast fail, we still requeue
1384 * for queue congestion conditions (QUEUE_FULL or BUSY) */
1385 if ((++scmd->retries) <= scmd->allowed
1386 && !blk_noretry_request(scmd->request)) {
1390 * no more retries - report this one back to upper level.
1397 * scsi_eh_lock_door - Prevent medium removal for the specified device
1398 * @sdev: SCSI device to prevent medium removal
1401 * We must be called from process context; scsi_allocate_request()
1405 * We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the
1406 * head of the devices request queue, and continue.
1409 * scsi_allocate_request() may sleep waiting for existing requests to
1410 * be processed. However, since we haven't kicked off any request
1411 * processing for this host, this may deadlock.
1413 * If scsi_allocate_request() fails for what ever reason, we
1414 * completely forget to lock the door.
1416 static void scsi_eh_lock_door(struct scsi_device *sdev)
1418 unsigned char cmnd[MAX_COMMAND_SIZE];
1420 cmnd[0] = ALLOW_MEDIUM_REMOVAL;
1424 cmnd[4] = SCSI_REMOVAL_PREVENT;
1427 scsi_execute_async(sdev, cmnd, 6, DMA_NONE, NULL, 0, 0, 10 * HZ,
1428 5, NULL, NULL, GFP_KERNEL);
1433 * scsi_restart_operations - restart io operations to the specified host.
1434 * @shost: Host we are restarting.
1437 * When we entered the error handler, we blocked all further i/o to
1438 * this device. we need to 'reverse' this process.
1440 static void scsi_restart_operations(struct Scsi_Host *shost)
1442 struct scsi_device *sdev;
1443 unsigned long flags;
1446 * If the door was locked, we need to insert a door lock request
1447 * onto the head of the SCSI request queue for the device. There
1448 * is no point trying to lock the door of an off-line device.
1450 shost_for_each_device(sdev, shost) {
1451 if (scsi_device_online(sdev) && sdev->locked)
1452 scsi_eh_lock_door(sdev);
1456 * next free up anything directly waiting upon the host. this
1457 * will be requests for character device operations, and also for
1458 * ioctls to queued block devices.
1460 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: waking up host to restart\n",
1463 spin_lock_irqsave(shost->host_lock, flags);
1464 if (scsi_host_set_state(shost, SHOST_RUNNING))
1465 if (scsi_host_set_state(shost, SHOST_CANCEL))
1466 BUG_ON(scsi_host_set_state(shost, SHOST_DEL));
1467 spin_unlock_irqrestore(shost->host_lock, flags);
1469 wake_up(&shost->host_wait);
1472 * finally we need to re-initiate requests that may be pending. we will
1473 * have had everything blocked while error handling is taking place, and
1474 * now that error recovery is done, we will need to ensure that these
1475 * requests are started.
1477 scsi_run_host_queues(shost);
1481 * scsi_eh_ready_devs - check device ready state and recover if not.
1482 * @shost: host to be recovered.
1483 * @work_q: &list_head for pending commands.
1484 * @done_q: &list_head for processed commands.
1486 void scsi_eh_ready_devs(struct Scsi_Host *shost,
1487 struct list_head *work_q,
1488 struct list_head *done_q)
1490 if (!scsi_eh_stu(shost, work_q, done_q))
1491 if (!scsi_eh_bus_device_reset(shost, work_q, done_q))
1492 if (!scsi_eh_target_reset(shost, work_q, done_q))
1493 if (!scsi_eh_bus_reset(shost, work_q, done_q))
1494 if (!scsi_eh_host_reset(work_q, done_q))
1495 scsi_eh_offline_sdevs(work_q,
1498 EXPORT_SYMBOL_GPL(scsi_eh_ready_devs);
1501 * scsi_eh_flush_done_q - finish processed commands or retry them.
1502 * @done_q: list_head of processed commands.
1504 void scsi_eh_flush_done_q(struct list_head *done_q)
1506 struct scsi_cmnd *scmd, *next;
1508 list_for_each_entry_safe(scmd, next, done_q, eh_entry) {
1509 list_del_init(&scmd->eh_entry);
1510 if (scsi_device_online(scmd->device) &&
1511 !blk_noretry_request(scmd->request) &&
1512 (++scmd->retries <= scmd->allowed)) {
1513 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush"
1517 scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY);
1520 * If just we got sense for the device (called
1521 * scsi_eh_get_sense), scmd->result is already
1522 * set, do not set DRIVER_TIMEOUT.
1525 scmd->result |= (DRIVER_TIMEOUT << 24);
1526 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush finish"
1528 current->comm, scmd));
1529 scsi_finish_command(scmd);
1533 EXPORT_SYMBOL(scsi_eh_flush_done_q);
1536 * scsi_unjam_host - Attempt to fix a host which has a cmd that failed.
1537 * @shost: Host to unjam.
1540 * When we come in here, we *know* that all commands on the bus have
1541 * either completed, failed or timed out. we also know that no further
1542 * commands are being sent to the host, so things are relatively quiet
1543 * and we have freedom to fiddle with things as we wish.
1545 * This is only the *default* implementation. it is possible for
1546 * individual drivers to supply their own version of this function, and
1547 * if the maintainer wishes to do this, it is strongly suggested that
1548 * this function be taken as a template and modified. this function
1549 * was designed to correctly handle problems for about 95% of the
1550 * different cases out there, and it should always provide at least a
1551 * reasonable amount of error recovery.
1553 * Any command marked 'failed' or 'timeout' must eventually have
1554 * scsi_finish_cmd() called for it. we do all of the retry stuff
1555 * here, so when we restart the host after we return it should have an
1558 static void scsi_unjam_host(struct Scsi_Host *shost)
1560 unsigned long flags;
1561 LIST_HEAD(eh_work_q);
1562 LIST_HEAD(eh_done_q);
1564 spin_lock_irqsave(shost->host_lock, flags);
1565 list_splice_init(&shost->eh_cmd_q, &eh_work_q);
1566 spin_unlock_irqrestore(shost->host_lock, flags);
1568 SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(shost, &eh_work_q));
1570 if (!scsi_eh_get_sense(&eh_work_q, &eh_done_q))
1571 if (!scsi_eh_abort_cmds(&eh_work_q, &eh_done_q))
1572 scsi_eh_ready_devs(shost, &eh_work_q, &eh_done_q);
1574 scsi_eh_flush_done_q(&eh_done_q);
1578 * scsi_error_handler - SCSI error handler thread
1579 * @data: Host for which we are running.
1582 * This is the main error handling loop. This is run as a kernel thread
1583 * for every SCSI host and handles all error handling activity.
1585 int scsi_error_handler(void *data)
1587 struct Scsi_Host *shost = data;
1590 * We use TASK_INTERRUPTIBLE so that the thread is not
1591 * counted against the load average as a running process.
1592 * We never actually get interrupted because kthread_run
1593 * disables singal delivery for the created thread.
1595 set_current_state(TASK_INTERRUPTIBLE);
1596 while (!kthread_should_stop()) {
1597 if ((shost->host_failed == 0 && shost->host_eh_scheduled == 0) ||
1598 shost->host_failed != shost->host_busy) {
1599 SCSI_LOG_ERROR_RECOVERY(1,
1600 printk("Error handler scsi_eh_%d sleeping\n",
1603 set_current_state(TASK_INTERRUPTIBLE);
1607 __set_current_state(TASK_RUNNING);
1608 SCSI_LOG_ERROR_RECOVERY(1,
1609 printk("Error handler scsi_eh_%d waking up\n",
1613 * We have a host that is failing for some reason. Figure out
1614 * what we need to do to get it up and online again (if we can).
1615 * If we fail, we end up taking the thing offline.
1617 if (shost->transportt->eh_strategy_handler)
1618 shost->transportt->eh_strategy_handler(shost);
1620 scsi_unjam_host(shost);
1623 * Note - if the above fails completely, the action is to take
1624 * individual devices offline and flush the queue of any
1625 * outstanding requests that may have been pending. When we
1626 * restart, we restart any I/O to any other devices on the bus
1627 * which are still online.
1629 scsi_restart_operations(shost);
1630 set_current_state(TASK_INTERRUPTIBLE);
1632 __set_current_state(TASK_RUNNING);
1634 SCSI_LOG_ERROR_RECOVERY(1,
1635 printk("Error handler scsi_eh_%d exiting\n", shost->host_no));
1636 shost->ehandler = NULL;
1641 * Function: scsi_report_bus_reset()
1643 * Purpose: Utility function used by low-level drivers to report that
1644 * they have observed a bus reset on the bus being handled.
1646 * Arguments: shost - Host in question
1647 * channel - channel on which reset was observed.
1651 * Lock status: Host lock must be held.
1653 * Notes: This only needs to be called if the reset is one which
1654 * originates from an unknown location. Resets originated
1655 * by the mid-level itself don't need to call this, but there
1656 * should be no harm.
1658 * The main purpose of this is to make sure that a CHECK_CONDITION
1659 * is properly treated.
1661 void scsi_report_bus_reset(struct Scsi_Host *shost, int channel)
1663 struct scsi_device *sdev;
1665 __shost_for_each_device(sdev, shost) {
1666 if (channel == sdev_channel(sdev))
1667 __scsi_report_device_reset(sdev, NULL);
1670 EXPORT_SYMBOL(scsi_report_bus_reset);
1673 * Function: scsi_report_device_reset()
1675 * Purpose: Utility function used by low-level drivers to report that
1676 * they have observed a device reset on the device being handled.
1678 * Arguments: shost - Host in question
1679 * channel - channel on which reset was observed
1680 * target - target on which reset was observed
1684 * Lock status: Host lock must be held
1686 * Notes: This only needs to be called if the reset is one which
1687 * originates from an unknown location. Resets originated
1688 * by the mid-level itself don't need to call this, but there
1689 * should be no harm.
1691 * The main purpose of this is to make sure that a CHECK_CONDITION
1692 * is properly treated.
1694 void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
1696 struct scsi_device *sdev;
1698 __shost_for_each_device(sdev, shost) {
1699 if (channel == sdev_channel(sdev) &&
1700 target == sdev_id(sdev))
1701 __scsi_report_device_reset(sdev, NULL);
1704 EXPORT_SYMBOL(scsi_report_device_reset);
1707 scsi_reset_provider_done_command(struct scsi_cmnd *scmd)
1712 * Function: scsi_reset_provider
1714 * Purpose: Send requested reset to a bus or device at any phase.
1716 * Arguments: device - device to send reset to
1717 * flag - reset type (see scsi.h)
1719 * Returns: SUCCESS/FAILURE.
1721 * Notes: This is used by the SCSI Generic driver to provide
1722 * Bus/Device reset capability.
1725 scsi_reset_provider(struct scsi_device *dev, int flag)
1727 struct scsi_cmnd *scmd = scsi_get_command(dev, GFP_KERNEL);
1728 struct Scsi_Host *shost = dev->host;
1730 unsigned long flags;
1733 blk_rq_init(NULL, &req);
1734 scmd->request = &req;
1736 scmd->cmnd = req.cmd;
1738 scmd->scsi_done = scsi_reset_provider_done_command;
1739 memset(&scmd->sdb, 0, sizeof(scmd->sdb));
1743 scmd->sc_data_direction = DMA_BIDIRECTIONAL;
1745 spin_lock_irqsave(shost->host_lock, flags);
1746 shost->tmf_in_progress = 1;
1747 spin_unlock_irqrestore(shost->host_lock, flags);
1750 case SCSI_TRY_RESET_DEVICE:
1751 rtn = scsi_try_bus_device_reset(scmd);
1755 case SCSI_TRY_RESET_TARGET:
1756 rtn = scsi_try_target_reset(scmd);
1760 case SCSI_TRY_RESET_BUS:
1761 rtn = scsi_try_bus_reset(scmd);
1765 case SCSI_TRY_RESET_HOST:
1766 rtn = scsi_try_host_reset(scmd);
1772 spin_lock_irqsave(shost->host_lock, flags);
1773 shost->tmf_in_progress = 0;
1774 spin_unlock_irqrestore(shost->host_lock, flags);
1777 * be sure to wake up anyone who was sleeping or had their queue
1778 * suspended while we performed the TMF.
1780 SCSI_LOG_ERROR_RECOVERY(3,
1781 printk("%s: waking up host to restart after TMF\n",
1784 wake_up(&shost->host_wait);
1786 scsi_run_host_queues(shost);
1788 scsi_next_command(scmd);
1791 EXPORT_SYMBOL(scsi_reset_provider);
1794 * scsi_normalize_sense - normalize main elements from either fixed or
1795 * descriptor sense data format into a common format.
1797 * @sense_buffer: byte array containing sense data returned by device
1798 * @sb_len: number of valid bytes in sense_buffer
1799 * @sshdr: pointer to instance of structure that common
1800 * elements are written to.
1803 * The "main elements" from sense data are: response_code, sense_key,
1804 * asc, ascq and additional_length (only for descriptor format).
1806 * Typically this function can be called after a device has
1807 * responded to a SCSI command with the CHECK_CONDITION status.
1810 * 1 if valid sense data information found, else 0;
1812 int scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
1813 struct scsi_sense_hdr *sshdr)
1815 if (!sense_buffer || !sb_len)
1818 memset(sshdr, 0, sizeof(struct scsi_sense_hdr));
1820 sshdr->response_code = (sense_buffer[0] & 0x7f);
1822 if (!scsi_sense_valid(sshdr))
1825 if (sshdr->response_code >= 0x72) {
1830 sshdr->sense_key = (sense_buffer[1] & 0xf);
1832 sshdr->asc = sense_buffer[2];
1834 sshdr->ascq = sense_buffer[3];
1836 sshdr->additional_length = sense_buffer[7];
1842 sshdr->sense_key = (sense_buffer[2] & 0xf);
1844 sb_len = (sb_len < (sense_buffer[7] + 8)) ?
1845 sb_len : (sense_buffer[7] + 8);
1847 sshdr->asc = sense_buffer[12];
1849 sshdr->ascq = sense_buffer[13];
1855 EXPORT_SYMBOL(scsi_normalize_sense);
1857 int scsi_command_normalize_sense(struct scsi_cmnd *cmd,
1858 struct scsi_sense_hdr *sshdr)
1860 return scsi_normalize_sense(cmd->sense_buffer,
1861 SCSI_SENSE_BUFFERSIZE, sshdr);
1863 EXPORT_SYMBOL(scsi_command_normalize_sense);
1866 * scsi_sense_desc_find - search for a given descriptor type in descriptor sense data format.
1867 * @sense_buffer: byte array of descriptor format sense data
1868 * @sb_len: number of valid bytes in sense_buffer
1869 * @desc_type: value of descriptor type to find
1870 * (e.g. 0 -> information)
1873 * only valid when sense data is in descriptor format
1876 * pointer to start of (first) descriptor if found else NULL
1878 const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
1881 int add_sen_len, add_len, desc_len, k;
1884 if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7])))
1886 if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73))
1888 add_sen_len = (add_sen_len < (sb_len - 8)) ?
1889 add_sen_len : (sb_len - 8);
1890 descp = &sense_buffer[8];
1891 for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) {
1893 add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
1894 desc_len = add_len + 2;
1895 if (descp[0] == desc_type)
1897 if (add_len < 0) // short descriptor ??
1902 EXPORT_SYMBOL(scsi_sense_desc_find);
1905 * scsi_get_sense_info_fld - get information field from sense data (either fixed or descriptor format)
1906 * @sense_buffer: byte array of sense data
1907 * @sb_len: number of valid bytes in sense_buffer
1908 * @info_out: pointer to 64 integer where 8 or 4 byte information
1909 * field will be placed if found.
1912 * 1 if information field found, 0 if not found.
1914 int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len,
1923 switch (sense_buffer[0] & 0x7f) {
1926 if (sense_buffer[0] & 0x80) {
1927 *info_out = (sense_buffer[3] << 24) +
1928 (sense_buffer[4] << 16) +
1929 (sense_buffer[5] << 8) + sense_buffer[6];
1935 ucp = scsi_sense_desc_find(sense_buffer, sb_len,
1937 if (ucp && (0xa == ucp[1])) {
1939 for (j = 0; j < 8; ++j) {
1952 EXPORT_SYMBOL(scsi_get_sense_info_fld);
1955 * scsi_build_sense_buffer - build sense data in a buffer
1956 * @desc: Sense format (non zero == descriptor format,
1957 * 0 == fixed format)
1958 * @buf: Where to build sense data
1960 * @asc: Additional sense code
1961 * @ascq: Additional sense code qualifier
1964 void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq)
1967 buf[0] = 0x72; /* descriptor, current */
1973 buf[0] = 0x70; /* fixed, current */
1980 EXPORT_SYMBOL(scsi_build_sense_buffer);