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1/*
2 * scsi_error.c Copyright (C) 1997 Eric Youngdale
3 *
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.
8 *
9 * Restructured scsi_unjam_host and associated functions.
10 * September 04, 2002 Mike Anderson (andmike@us.ibm.com)
11 *
12 * Forward port of Russell King's (rmk@arm.linux.org.uk) changes and
13 * minor cleanups.
14 * September 30, 2002 Mike Anderson (andmike@us.ibm.com)
15 */
16
17#include <linux/module.h>
18#include <linux/sched.h>
19#include <linux/gfp.h>
20#include <linux/timer.h>
21#include <linux/string.h>
22#include <linux/kernel.h>
23#include <linux/freezer.h>
24#include <linux/kthread.h>
25#include <linux/interrupt.h>
26#include <linux/blkdev.h>
27#include <linux/delay.h>
28#include <linux/jiffies.h>
29
30#include <scsi/scsi.h>
31#include <scsi/scsi_cmnd.h>
32#include <scsi/scsi_dbg.h>
33#include <scsi/scsi_device.h>
34#include <scsi/scsi_driver.h>
35#include <scsi/scsi_eh.h>
36#include <scsi/scsi_common.h>
37#include <scsi/scsi_transport.h>
38#include <scsi/scsi_host.h>
39#include <scsi/scsi_ioctl.h>
40#include <scsi/scsi_dh.h>
41#include <scsi/sg.h>
42
43#include "scsi_priv.h"
44#include "scsi_logging.h"
45#include "scsi_transport_api.h"
46
47#include <trace/events/scsi.h>
48
49static void scsi_eh_done(struct scsi_cmnd *scmd);
50
51/*
52 * These should *probably* be handled by the host itself.
53 * Since it is allowed to sleep, it probably should.
54 */
55#define BUS_RESET_SETTLE_TIME (10)
56#define HOST_RESET_SETTLE_TIME (10)
57
58static int scsi_eh_try_stu(struct scsi_cmnd *scmd);
59static int scsi_try_to_abort_cmd(struct scsi_host_template *,
60 struct scsi_cmnd *);
61
62/* called with shost->host_lock held */
63void scsi_eh_wakeup(struct Scsi_Host *shost)
64{
65 if (atomic_read(&shost->host_busy) == shost->host_failed) {
66 trace_scsi_eh_wakeup(shost);
67 wake_up_process(shost->ehandler);
68 SCSI_LOG_ERROR_RECOVERY(5, shost_printk(KERN_INFO, shost,
69 "Waking error handler thread\n"));
70 }
71}
72
73/**
74 * scsi_schedule_eh - schedule EH for SCSI host
75 * @shost: SCSI host to invoke error handling on.
76 *
77 * Schedule SCSI EH without scmd.
78 */
79void scsi_schedule_eh(struct Scsi_Host *shost)
80{
81 unsigned long flags;
82
83 spin_lock_irqsave(shost->host_lock, flags);
84
85 if (scsi_host_set_state(shost, SHOST_RECOVERY) == 0 ||
86 scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY) == 0) {
87 shost->host_eh_scheduled++;
88 scsi_eh_wakeup(shost);
89 }
90
91 spin_unlock_irqrestore(shost->host_lock, flags);
92}
93EXPORT_SYMBOL_GPL(scsi_schedule_eh);
94
95static int scsi_host_eh_past_deadline(struct Scsi_Host *shost)
96{
97 if (!shost->last_reset || shost->eh_deadline == -1)
98 return 0;
99
100 /*
101 * 32bit accesses are guaranteed to be atomic
102 * (on all supported architectures), so instead
103 * of using a spinlock we can as well double check
104 * if eh_deadline has been set to 'off' during the
105 * time_before call.
106 */
107 if (time_before(jiffies, shost->last_reset + shost->eh_deadline) &&
108 shost->eh_deadline > -1)
109 return 0;
110
111 return 1;
112}
113
114/**
115 * scmd_eh_abort_handler - Handle command aborts
116 * @work: command to be aborted.
117 */
118void
119scmd_eh_abort_handler(struct work_struct *work)
120{
121 struct scsi_cmnd *scmd =
122 container_of(work, struct scsi_cmnd, abort_work.work);
123 struct scsi_device *sdev = scmd->device;
124 int rtn;
125
126 if (scsi_host_eh_past_deadline(sdev->host)) {
127 SCSI_LOG_ERROR_RECOVERY(3,
128 scmd_printk(KERN_INFO, scmd,
129 "eh timeout, not aborting\n"));
130 } else {
131 SCSI_LOG_ERROR_RECOVERY(3,
132 scmd_printk(KERN_INFO, scmd,
133 "aborting command\n"));
134 rtn = scsi_try_to_abort_cmd(sdev->host->hostt, scmd);
135 if (rtn == SUCCESS) {
136 set_host_byte(scmd, DID_TIME_OUT);
137 if (scsi_host_eh_past_deadline(sdev->host)) {
138 SCSI_LOG_ERROR_RECOVERY(3,
139 scmd_printk(KERN_INFO, scmd,
140 "eh timeout, not retrying "
141 "aborted command\n"));
142 } else if (!scsi_noretry_cmd(scmd) &&
143 (++scmd->retries <= scmd->allowed)) {
144 SCSI_LOG_ERROR_RECOVERY(3,
145 scmd_printk(KERN_WARNING, scmd,
146 "retry aborted command\n"));
147 scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY);
148 return;
149 } else {
150 SCSI_LOG_ERROR_RECOVERY(3,
151 scmd_printk(KERN_WARNING, scmd,
152 "finish aborted command\n"));
153 scsi_finish_command(scmd);
154 return;
155 }
156 } else {
157 SCSI_LOG_ERROR_RECOVERY(3,
158 scmd_printk(KERN_INFO, scmd,
159 "cmd abort %s\n",
160 (rtn == FAST_IO_FAIL) ?
161 "not send" : "failed"));
162 }
163 }
164
165 if (!scsi_eh_scmd_add(scmd, 0)) {
166 SCSI_LOG_ERROR_RECOVERY(3,
167 scmd_printk(KERN_WARNING, scmd,
168 "terminate aborted command\n"));
169 set_host_byte(scmd, DID_TIME_OUT);
170 scsi_finish_command(scmd);
171 }
172}
173
174/**
175 * scsi_abort_command - schedule a command abort
176 * @scmd: scmd to abort.
177 *
178 * We only need to abort commands after a command timeout
179 */
180static int
181scsi_abort_command(struct scsi_cmnd *scmd)
182{
183 struct scsi_device *sdev = scmd->device;
184 struct Scsi_Host *shost = sdev->host;
185 unsigned long flags;
186
187 if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) {
188 /*
189 * Retry after abort failed, escalate to next level.
190 */
191 scmd->eh_eflags &= ~SCSI_EH_ABORT_SCHEDULED;
192 SCSI_LOG_ERROR_RECOVERY(3,
193 scmd_printk(KERN_INFO, scmd,
194 "previous abort failed\n"));
195 BUG_ON(delayed_work_pending(&scmd->abort_work));
196 return FAILED;
197 }
198
199 /*
200 * Do not try a command abort if
201 * SCSI EH has already started.
202 */
203 spin_lock_irqsave(shost->host_lock, flags);
204 if (scsi_host_in_recovery(shost)) {
205 spin_unlock_irqrestore(shost->host_lock, flags);
206 SCSI_LOG_ERROR_RECOVERY(3,
207 scmd_printk(KERN_INFO, scmd,
208 "not aborting, host in recovery\n"));
209 return FAILED;
210 }
211
212 if (shost->eh_deadline != -1 && !shost->last_reset)
213 shost->last_reset = jiffies;
214 spin_unlock_irqrestore(shost->host_lock, flags);
215
216 scmd->eh_eflags |= SCSI_EH_ABORT_SCHEDULED;
217 SCSI_LOG_ERROR_RECOVERY(3,
218 scmd_printk(KERN_INFO, scmd, "abort scheduled\n"));
219 queue_delayed_work(shost->tmf_work_q, &scmd->abort_work, HZ / 100);
220 return SUCCESS;
221}
222
223/**
224 * scsi_eh_scmd_add - add scsi cmd to error handling.
225 * @scmd: scmd to run eh on.
226 * @eh_flag: optional SCSI_EH flag.
227 *
228 * Return value:
229 * 0 on failure.
230 */
231int scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag)
232{
233 struct Scsi_Host *shost = scmd->device->host;
234 unsigned long flags;
235 int ret = 0;
236
237 if (!shost->ehandler)
238 return 0;
239
240 spin_lock_irqsave(shost->host_lock, flags);
241 if (scsi_host_set_state(shost, SHOST_RECOVERY))
242 if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY))
243 goto out_unlock;
244
245 if (shost->eh_deadline != -1 && !shost->last_reset)
246 shost->last_reset = jiffies;
247
248 ret = 1;
249 if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED)
250 eh_flag &= ~SCSI_EH_CANCEL_CMD;
251 scmd->eh_eflags |= eh_flag;
252 list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q);
253 shost->host_failed++;
254 scsi_eh_wakeup(shost);
255 out_unlock:
256 spin_unlock_irqrestore(shost->host_lock, flags);
257 return ret;
258}
259
260/**
261 * scsi_times_out - Timeout function for normal scsi commands.
262 * @req: request that is timing out.
263 *
264 * Notes:
265 * We do not need to lock this. There is the potential for a race
266 * only in that the normal completion handling might run, but if the
267 * normal completion function determines that the timer has already
268 * fired, then it mustn't do anything.
269 */
270enum blk_eh_timer_return scsi_times_out(struct request *req)
271{
272 struct scsi_cmnd *scmd = req->special;
273 enum blk_eh_timer_return rtn = BLK_EH_NOT_HANDLED;
274 struct Scsi_Host *host = scmd->device->host;
275
276 trace_scsi_dispatch_cmd_timeout(scmd);
277 scsi_log_completion(scmd, TIMEOUT_ERROR);
278
279 if (host->eh_deadline != -1 && !host->last_reset)
280 host->last_reset = jiffies;
281
282 if (host->transportt->eh_timed_out)
283 rtn = host->transportt->eh_timed_out(scmd);
284 else if (host->hostt->eh_timed_out)
285 rtn = host->hostt->eh_timed_out(scmd);
286
287 if (rtn == BLK_EH_NOT_HANDLED) {
288 if (!host->hostt->no_async_abort &&
289 scsi_abort_command(scmd) == SUCCESS)
290 return BLK_EH_NOT_HANDLED;
291
292 set_host_byte(scmd, DID_TIME_OUT);
293 if (!scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD))
294 rtn = BLK_EH_HANDLED;
295 }
296
297 return rtn;
298}
299
300/**
301 * scsi_block_when_processing_errors - Prevent cmds from being queued.
302 * @sdev: Device on which we are performing recovery.
303 *
304 * Description:
305 * We block until the host is out of error recovery, and then check to
306 * see whether the host or the device is offline.
307 *
308 * Return value:
309 * 0 when dev was taken offline by error recovery. 1 OK to proceed.
310 */
311int scsi_block_when_processing_errors(struct scsi_device *sdev)
312{
313 int online;
314
315 wait_event(sdev->host->host_wait, !scsi_host_in_recovery(sdev->host));
316
317 online = scsi_device_online(sdev);
318
319 SCSI_LOG_ERROR_RECOVERY(5, sdev_printk(KERN_INFO, sdev,
320 "%s: rtn: %d\n", __func__, online));
321
322 return online;
323}
324EXPORT_SYMBOL(scsi_block_when_processing_errors);
325
326#ifdef CONFIG_SCSI_LOGGING
327/**
328 * scsi_eh_prt_fail_stats - Log info on failures.
329 * @shost: scsi host being recovered.
330 * @work_q: Queue of scsi cmds to process.
331 */
332static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost,
333 struct list_head *work_q)
334{
335 struct scsi_cmnd *scmd;
336 struct scsi_device *sdev;
337 int total_failures = 0;
338 int cmd_failed = 0;
339 int cmd_cancel = 0;
340 int devices_failed = 0;
341
342 shost_for_each_device(sdev, shost) {
343 list_for_each_entry(scmd, work_q, eh_entry) {
344 if (scmd->device == sdev) {
345 ++total_failures;
346 if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD)
347 ++cmd_cancel;
348 else
349 ++cmd_failed;
350 }
351 }
352
353 if (cmd_cancel || cmd_failed) {
354 SCSI_LOG_ERROR_RECOVERY(3,
355 shost_printk(KERN_INFO, shost,
356 "%s: cmds failed: %d, cancel: %d\n",
357 __func__, cmd_failed,
358 cmd_cancel));
359 cmd_cancel = 0;
360 cmd_failed = 0;
361 ++devices_failed;
362 }
363 }
364
365 SCSI_LOG_ERROR_RECOVERY(2, shost_printk(KERN_INFO, shost,
366 "Total of %d commands on %d"
367 " devices require eh work\n",
368 total_failures, devices_failed));
369}
370#endif
371
372 /**
373 * scsi_report_lun_change - Set flag on all *other* devices on the same target
374 * to indicate that a UNIT ATTENTION is expected.
375 * @sdev: Device reporting the UNIT ATTENTION
376 */
377static void scsi_report_lun_change(struct scsi_device *sdev)
378{
379 sdev->sdev_target->expecting_lun_change = 1;
380}
381
382/**
383 * scsi_report_sense - Examine scsi sense information and log messages for
384 * certain conditions, also issue uevents for some of them.
385 * @sdev: Device reporting the sense code
386 * @sshdr: sshdr to be examined
387 */
388static void scsi_report_sense(struct scsi_device *sdev,
389 struct scsi_sense_hdr *sshdr)
390{
391 enum scsi_device_event evt_type = SDEV_EVT_MAXBITS; /* i.e. none */
392
393 if (sshdr->sense_key == UNIT_ATTENTION) {
394 if (sshdr->asc == 0x3f && sshdr->ascq == 0x03) {
395 evt_type = SDEV_EVT_INQUIRY_CHANGE_REPORTED;
396 sdev_printk(KERN_WARNING, sdev,
397 "Inquiry data has changed");
398 } else if (sshdr->asc == 0x3f && sshdr->ascq == 0x0e) {
399 evt_type = SDEV_EVT_LUN_CHANGE_REPORTED;
400 scsi_report_lun_change(sdev);
401 sdev_printk(KERN_WARNING, sdev,
402 "Warning! Received an indication that the "
403 "LUN assignments on this target have "
404 "changed. The Linux SCSI layer does not "
405 "automatically remap LUN assignments.\n");
406 } else if (sshdr->asc == 0x3f)
407 sdev_printk(KERN_WARNING, sdev,
408 "Warning! Received an indication that the "
409 "operating parameters on this target have "
410 "changed. The Linux SCSI layer does not "
411 "automatically adjust these parameters.\n");
412
413 if (sshdr->asc == 0x38 && sshdr->ascq == 0x07) {
414 evt_type = SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED;
415 sdev_printk(KERN_WARNING, sdev,
416 "Warning! Received an indication that the "
417 "LUN reached a thin provisioning soft "
418 "threshold.\n");
419 }
420
421 if (sshdr->asc == 0x2a && sshdr->ascq == 0x01) {
422 evt_type = SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED;
423 sdev_printk(KERN_WARNING, sdev,
424 "Mode parameters changed");
425 } else if (sshdr->asc == 0x2a && sshdr->ascq == 0x06) {
426 evt_type = SDEV_EVT_ALUA_STATE_CHANGE_REPORTED;
427 sdev_printk(KERN_WARNING, sdev,
428 "Asymmetric access state changed");
429 } else if (sshdr->asc == 0x2a && sshdr->ascq == 0x09) {
430 evt_type = SDEV_EVT_CAPACITY_CHANGE_REPORTED;
431 sdev_printk(KERN_WARNING, sdev,
432 "Capacity data has changed");
433 } else if (sshdr->asc == 0x2a)
434 sdev_printk(KERN_WARNING, sdev,
435 "Parameters changed");
436 }
437
438 if (evt_type != SDEV_EVT_MAXBITS) {
439 set_bit(evt_type, sdev->pending_events);
440 schedule_work(&sdev->event_work);
441 }
442}
443
444/**
445 * scsi_check_sense - Examine scsi cmd sense
446 * @scmd: Cmd to have sense checked.
447 *
448 * Return value:
449 * SUCCESS or FAILED or NEEDS_RETRY or ADD_TO_MLQUEUE
450 *
451 * Notes:
452 * When a deferred error is detected the current command has
453 * not been executed and needs retrying.
454 */
455static int scsi_check_sense(struct scsi_cmnd *scmd)
456{
457 struct scsi_device *sdev = scmd->device;
458 struct scsi_sense_hdr sshdr;
459
460 if (! scsi_command_normalize_sense(scmd, &sshdr))
461 return FAILED; /* no valid sense data */
462
463 scsi_report_sense(sdev, &sshdr);
464
465 if (scsi_sense_is_deferred(&sshdr))
466 return NEEDS_RETRY;
467
468 if (sdev->handler && sdev->handler->check_sense) {
469 int rc;
470
471 rc = sdev->handler->check_sense(sdev, &sshdr);
472 if (rc != SCSI_RETURN_NOT_HANDLED)
473 return rc;
474 /* handler does not care. Drop down to default handling */
475 }
476
477 if (scmd->cmnd[0] == TEST_UNIT_READY && scmd->scsi_done != scsi_eh_done)
478 /*
479 * nasty: for mid-layer issued TURs, we need to return the
480 * actual sense data without any recovery attempt. For eh
481 * issued ones, we need to try to recover and interpret
482 */
483 return SUCCESS;
484
485 /*
486 * Previous logic looked for FILEMARK, EOM or ILI which are
487 * mainly associated with tapes and returned SUCCESS.
488 */
489 if (sshdr.response_code == 0x70) {
490 /* fixed format */
491 if (scmd->sense_buffer[2] & 0xe0)
492 return SUCCESS;
493 } else {
494 /*
495 * descriptor format: look for "stream commands sense data
496 * descriptor" (see SSC-3). Assume single sense data
497 * descriptor. Ignore ILI from SBC-2 READ LONG and WRITE LONG.
498 */
499 if ((sshdr.additional_length > 3) &&
500 (scmd->sense_buffer[8] == 0x4) &&
501 (scmd->sense_buffer[11] & 0xe0))
502 return SUCCESS;
503 }
504
505 switch (sshdr.sense_key) {
506 case NO_SENSE:
507 return SUCCESS;
508 case RECOVERED_ERROR:
509 return /* soft_error */ SUCCESS;
510
511 case ABORTED_COMMAND:
512 if (sshdr.asc == 0x10) /* DIF */
513 return SUCCESS;
514
515 return NEEDS_RETRY;
516 case NOT_READY:
517 case UNIT_ATTENTION:
518 /*
519 * if we are expecting a cc/ua because of a bus reset that we
520 * performed, treat this just as a retry. otherwise this is
521 * information that we should pass up to the upper-level driver
522 * so that we can deal with it there.
523 */
524 if (scmd->device->expecting_cc_ua) {
525 /*
526 * Because some device does not queue unit
527 * attentions correctly, we carefully check
528 * additional sense code and qualifier so as
529 * not to squash media change unit attention.
530 */
531 if (sshdr.asc != 0x28 || sshdr.ascq != 0x00) {
532 scmd->device->expecting_cc_ua = 0;
533 return NEEDS_RETRY;
534 }
535 }
536 /*
537 * we might also expect a cc/ua if another LUN on the target
538 * reported a UA with an ASC/ASCQ of 3F 0E -
539 * REPORTED LUNS DATA HAS CHANGED.
540 */
541 if (scmd->device->sdev_target->expecting_lun_change &&
542 sshdr.asc == 0x3f && sshdr.ascq == 0x0e)
543 return NEEDS_RETRY;
544 /*
545 * if the device is in the process of becoming ready, we
546 * should retry.
547 */
548 if ((sshdr.asc == 0x04) && (sshdr.ascq == 0x01))
549 return NEEDS_RETRY;
550 /*
551 * if the device is not started, we need to wake
552 * the error handler to start the motor
553 */
554 if (scmd->device->allow_restart &&
555 (sshdr.asc == 0x04) && (sshdr.ascq == 0x02))
556 return FAILED;
557 /*
558 * Pass the UA upwards for a determination in the completion
559 * functions.
560 */
561 return SUCCESS;
562
563 /* these are not supported */
564 case DATA_PROTECT:
565 if (sshdr.asc == 0x27 && sshdr.ascq == 0x07) {
566 /* Thin provisioning hard threshold reached */
567 set_host_byte(scmd, DID_ALLOC_FAILURE);
568 return SUCCESS;
569 }
570 case COPY_ABORTED:
571 case VOLUME_OVERFLOW:
572 case MISCOMPARE:
573 case BLANK_CHECK:
574 set_host_byte(scmd, DID_TARGET_FAILURE);
575 return SUCCESS;
576
577 case MEDIUM_ERROR:
578 if (sshdr.asc == 0x11 || /* UNRECOVERED READ ERR */
579 sshdr.asc == 0x13 || /* AMNF DATA FIELD */
580 sshdr.asc == 0x14) { /* RECORD NOT FOUND */
581 set_host_byte(scmd, DID_MEDIUM_ERROR);
582 return SUCCESS;
583 }
584 return NEEDS_RETRY;
585
586 case HARDWARE_ERROR:
587 if (scmd->device->retry_hwerror)
588 return ADD_TO_MLQUEUE;
589 else
590 set_host_byte(scmd, DID_TARGET_FAILURE);
591
592 case ILLEGAL_REQUEST:
593 if (sshdr.asc == 0x20 || /* Invalid command operation code */
594 sshdr.asc == 0x21 || /* Logical block address out of range */
595 sshdr.asc == 0x24 || /* Invalid field in cdb */
596 sshdr.asc == 0x26) { /* Parameter value invalid */
597 set_host_byte(scmd, DID_TARGET_FAILURE);
598 }
599 return SUCCESS;
600
601 default:
602 return SUCCESS;
603 }
604}
605
606static void scsi_handle_queue_ramp_up(struct scsi_device *sdev)
607{
608 struct scsi_host_template *sht = sdev->host->hostt;
609 struct scsi_device *tmp_sdev;
610
611 if (!sht->track_queue_depth ||
612 sdev->queue_depth >= sdev->max_queue_depth)
613 return;
614
615 if (time_before(jiffies,
616 sdev->last_queue_ramp_up + sdev->queue_ramp_up_period))
617 return;
618
619 if (time_before(jiffies,
620 sdev->last_queue_full_time + sdev->queue_ramp_up_period))
621 return;
622
623 /*
624 * Walk all devices of a target and do
625 * ramp up on them.
626 */
627 shost_for_each_device(tmp_sdev, sdev->host) {
628 if (tmp_sdev->channel != sdev->channel ||
629 tmp_sdev->id != sdev->id ||
630 tmp_sdev->queue_depth == sdev->max_queue_depth)
631 continue;
632
633 scsi_change_queue_depth(tmp_sdev, tmp_sdev->queue_depth + 1);
634 sdev->last_queue_ramp_up = jiffies;
635 }
636}
637
638static void scsi_handle_queue_full(struct scsi_device *sdev)
639{
640 struct scsi_host_template *sht = sdev->host->hostt;
641 struct scsi_device *tmp_sdev;
642
643 if (!sht->track_queue_depth)
644 return;
645
646 shost_for_each_device(tmp_sdev, sdev->host) {
647 if (tmp_sdev->channel != sdev->channel ||
648 tmp_sdev->id != sdev->id)
649 continue;
650 /*
651 * We do not know the number of commands that were at
652 * the device when we got the queue full so we start
653 * from the highest possible value and work our way down.
654 */
655 scsi_track_queue_full(tmp_sdev, tmp_sdev->queue_depth - 1);
656 }
657}
658
659/**
660 * scsi_eh_completed_normally - Disposition a eh cmd on return from LLD.
661 * @scmd: SCSI cmd to examine.
662 *
663 * Notes:
664 * This is *only* called when we are examining the status of commands
665 * queued during error recovery. the main difference here is that we
666 * don't allow for the possibility of retries here, and we are a lot
667 * more restrictive about what we consider acceptable.
668 */
669static int scsi_eh_completed_normally(struct scsi_cmnd *scmd)
670{
671 /*
672 * first check the host byte, to see if there is anything in there
673 * that would indicate what we need to do.
674 */
675 if (host_byte(scmd->result) == DID_RESET) {
676 /*
677 * rats. we are already in the error handler, so we now
678 * get to try and figure out what to do next. if the sense
679 * is valid, we have a pretty good idea of what to do.
680 * if not, we mark it as FAILED.
681 */
682 return scsi_check_sense(scmd);
683 }
684 if (host_byte(scmd->result) != DID_OK)
685 return FAILED;
686
687 /*
688 * next, check the message byte.
689 */
690 if (msg_byte(scmd->result) != COMMAND_COMPLETE)
691 return FAILED;
692
693 /*
694 * now, check the status byte to see if this indicates
695 * anything special.
696 */
697 switch (status_byte(scmd->result)) {
698 case GOOD:
699 scsi_handle_queue_ramp_up(scmd->device);
700 case COMMAND_TERMINATED:
701 return SUCCESS;
702 case CHECK_CONDITION:
703 return scsi_check_sense(scmd);
704 case CONDITION_GOOD:
705 case INTERMEDIATE_GOOD:
706 case INTERMEDIATE_C_GOOD:
707 /*
708 * who knows? FIXME(eric)
709 */
710 return SUCCESS;
711 case RESERVATION_CONFLICT:
712 if (scmd->cmnd[0] == TEST_UNIT_READY)
713 /* it is a success, we probed the device and
714 * found it */
715 return SUCCESS;
716 /* otherwise, we failed to send the command */
717 return FAILED;
718 case QUEUE_FULL:
719 scsi_handle_queue_full(scmd->device);
720 /* fall through */
721 case BUSY:
722 return NEEDS_RETRY;
723 default:
724 return FAILED;
725 }
726 return FAILED;
727}
728
729/**
730 * scsi_eh_done - Completion function for error handling.
731 * @scmd: Cmd that is done.
732 */
733static void scsi_eh_done(struct scsi_cmnd *scmd)
734{
735 struct completion *eh_action;
736
737 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
738 "%s result: %x\n", __func__, scmd->result));
739
740 eh_action = scmd->device->host->eh_action;
741 if (eh_action)
742 complete(eh_action);
743}
744
745/**
746 * scsi_try_host_reset - ask host adapter to reset itself
747 * @scmd: SCSI cmd to send host reset.
748 */
749static int scsi_try_host_reset(struct scsi_cmnd *scmd)
750{
751 unsigned long flags;
752 int rtn;
753 struct Scsi_Host *host = scmd->device->host;
754 struct scsi_host_template *hostt = host->hostt;
755
756 SCSI_LOG_ERROR_RECOVERY(3,
757 shost_printk(KERN_INFO, host, "Snd Host RST\n"));
758
759 if (!hostt->eh_host_reset_handler)
760 return FAILED;
761
762 rtn = hostt->eh_host_reset_handler(scmd);
763
764 if (rtn == SUCCESS) {
765 if (!hostt->skip_settle_delay)
766 ssleep(HOST_RESET_SETTLE_TIME);
767 spin_lock_irqsave(host->host_lock, flags);
768 scsi_report_bus_reset(host, scmd_channel(scmd));
769 spin_unlock_irqrestore(host->host_lock, flags);
770 }
771
772 return rtn;
773}
774
775/**
776 * scsi_try_bus_reset - ask host to perform a bus reset
777 * @scmd: SCSI cmd to send bus reset.
778 */
779static int scsi_try_bus_reset(struct scsi_cmnd *scmd)
780{
781 unsigned long flags;
782 int rtn;
783 struct Scsi_Host *host = scmd->device->host;
784 struct scsi_host_template *hostt = host->hostt;
785
786 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
787 "%s: Snd Bus RST\n", __func__));
788
789 if (!hostt->eh_bus_reset_handler)
790 return FAILED;
791
792 rtn = hostt->eh_bus_reset_handler(scmd);
793
794 if (rtn == SUCCESS) {
795 if (!hostt->skip_settle_delay)
796 ssleep(BUS_RESET_SETTLE_TIME);
797 spin_lock_irqsave(host->host_lock, flags);
798 scsi_report_bus_reset(host, scmd_channel(scmd));
799 spin_unlock_irqrestore(host->host_lock, flags);
800 }
801
802 return rtn;
803}
804
805static void __scsi_report_device_reset(struct scsi_device *sdev, void *data)
806{
807 sdev->was_reset = 1;
808 sdev->expecting_cc_ua = 1;
809}
810
811/**
812 * scsi_try_target_reset - Ask host to perform a target reset
813 * @scmd: SCSI cmd used to send a target reset
814 *
815 * Notes:
816 * There is no timeout for this operation. if this operation is
817 * unreliable for a given host, then the host itself needs to put a
818 * timer on it, and set the host back to a consistent state prior to
819 * returning.
820 */
821static int scsi_try_target_reset(struct scsi_cmnd *scmd)
822{
823 unsigned long flags;
824 int rtn;
825 struct Scsi_Host *host = scmd->device->host;
826 struct scsi_host_template *hostt = host->hostt;
827
828 if (!hostt->eh_target_reset_handler)
829 return FAILED;
830
831 rtn = hostt->eh_target_reset_handler(scmd);
832 if (rtn == SUCCESS) {
833 spin_lock_irqsave(host->host_lock, flags);
834 __starget_for_each_device(scsi_target(scmd->device), NULL,
835 __scsi_report_device_reset);
836 spin_unlock_irqrestore(host->host_lock, flags);
837 }
838
839 return rtn;
840}
841
842/**
843 * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev
844 * @scmd: SCSI cmd used to send BDR
845 *
846 * Notes:
847 * There is no timeout for this operation. if this operation is
848 * unreliable for a given host, then the host itself needs to put a
849 * timer on it, and set the host back to a consistent state prior to
850 * returning.
851 */
852static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd)
853{
854 int rtn;
855 struct scsi_host_template *hostt = scmd->device->host->hostt;
856
857 if (!hostt->eh_device_reset_handler)
858 return FAILED;
859
860 rtn = hostt->eh_device_reset_handler(scmd);
861 if (rtn == SUCCESS)
862 __scsi_report_device_reset(scmd->device, NULL);
863 return rtn;
864}
865
866/**
867 * scsi_try_to_abort_cmd - Ask host to abort a SCSI command
868 * @hostt: SCSI driver host template
869 * @scmd: SCSI cmd used to send a target reset
870 *
871 * Return value:
872 * SUCCESS, FAILED, or FAST_IO_FAIL
873 *
874 * Notes:
875 * SUCCESS does not necessarily indicate that the command
876 * has been aborted; it only indicates that the LLDDs
877 * has cleared all references to that command.
878 * LLDDs should return FAILED only if an abort was required
879 * but could not be executed. LLDDs should return FAST_IO_FAIL
880 * if the device is temporarily unavailable (eg due to a
881 * link down on FibreChannel)
882 */
883static int scsi_try_to_abort_cmd(struct scsi_host_template *hostt,
884 struct scsi_cmnd *scmd)
885{
886 if (!hostt->eh_abort_handler)
887 return FAILED;
888
889 return hostt->eh_abort_handler(scmd);
890}
891
892static void scsi_abort_eh_cmnd(struct scsi_cmnd *scmd)
893{
894 if (scsi_try_to_abort_cmd(scmd->device->host->hostt, scmd) != SUCCESS)
895 if (scsi_try_bus_device_reset(scmd) != SUCCESS)
896 if (scsi_try_target_reset(scmd) != SUCCESS)
897 if (scsi_try_bus_reset(scmd) != SUCCESS)
898 scsi_try_host_reset(scmd);
899}
900
901/**
902 * scsi_eh_prep_cmnd - Save a scsi command info as part of error recovery
903 * @scmd: SCSI command structure to hijack
904 * @ses: structure to save restore information
905 * @cmnd: CDB to send. Can be NULL if no new cmnd is needed
906 * @cmnd_size: size in bytes of @cmnd (must be <= BLK_MAX_CDB)
907 * @sense_bytes: size of sense data to copy. or 0 (if != 0 @cmnd is ignored)
908 *
909 * This function is used to save a scsi command information before re-execution
910 * as part of the error recovery process. If @sense_bytes is 0 the command
911 * sent must be one that does not transfer any data. If @sense_bytes != 0
912 * @cmnd is ignored and this functions sets up a REQUEST_SENSE command
913 * and cmnd buffers to read @sense_bytes into @scmd->sense_buffer.
914 */
915void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd, struct scsi_eh_save *ses,
916 unsigned char *cmnd, int cmnd_size, unsigned sense_bytes)
917{
918 struct scsi_device *sdev = scmd->device;
919
920 /*
921 * We need saved copies of a number of fields - this is because
922 * error handling may need to overwrite these with different values
923 * to run different commands, and once error handling is complete,
924 * we will need to restore these values prior to running the actual
925 * command.
926 */
927 ses->cmd_len = scmd->cmd_len;
928 ses->cmnd = scmd->cmnd;
929 ses->data_direction = scmd->sc_data_direction;
930 ses->sdb = scmd->sdb;
931 ses->next_rq = scmd->request->next_rq;
932 ses->result = scmd->result;
933 ses->underflow = scmd->underflow;
934 ses->prot_op = scmd->prot_op;
935
936 scmd->prot_op = SCSI_PROT_NORMAL;
937 scmd->eh_eflags = 0;
938 scmd->cmnd = ses->eh_cmnd;
939 memset(scmd->cmnd, 0, BLK_MAX_CDB);
940 memset(&scmd->sdb, 0, sizeof(scmd->sdb));
941 scmd->request->next_rq = NULL;
942 scmd->result = 0;
943
944 if (sense_bytes) {
945 scmd->sdb.length = min_t(unsigned, SCSI_SENSE_BUFFERSIZE,
946 sense_bytes);
947 sg_init_one(&ses->sense_sgl, scmd->sense_buffer,
948 scmd->sdb.length);
949 scmd->sdb.table.sgl = &ses->sense_sgl;
950 scmd->sc_data_direction = DMA_FROM_DEVICE;
951 scmd->sdb.table.nents = scmd->sdb.table.orig_nents = 1;
952 scmd->cmnd[0] = REQUEST_SENSE;
953 scmd->cmnd[4] = scmd->sdb.length;
954 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
955 } else {
956 scmd->sc_data_direction = DMA_NONE;
957 if (cmnd) {
958 BUG_ON(cmnd_size > BLK_MAX_CDB);
959 memcpy(scmd->cmnd, cmnd, cmnd_size);
960 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
961 }
962 }
963
964 scmd->underflow = 0;
965
966 if (sdev->scsi_level <= SCSI_2 && sdev->scsi_level != SCSI_UNKNOWN)
967 scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) |
968 (sdev->lun << 5 & 0xe0);
969
970 /*
971 * Zero the sense buffer. The scsi spec mandates that any
972 * untransferred sense data should be interpreted as being zero.
973 */
974 memset(scmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
975}
976EXPORT_SYMBOL(scsi_eh_prep_cmnd);
977
978/**
979 * scsi_eh_restore_cmnd - Restore a scsi command info as part of error recovery
980 * @scmd: SCSI command structure to restore
981 * @ses: saved information from a coresponding call to scsi_eh_prep_cmnd
982 *
983 * Undo any damage done by above scsi_eh_prep_cmnd().
984 */
985void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd, struct scsi_eh_save *ses)
986{
987 /*
988 * Restore original data
989 */
990 scmd->cmd_len = ses->cmd_len;
991 scmd->cmnd = ses->cmnd;
992 scmd->sc_data_direction = ses->data_direction;
993 scmd->sdb = ses->sdb;
994 scmd->request->next_rq = ses->next_rq;
995 scmd->result = ses->result;
996 scmd->underflow = ses->underflow;
997 scmd->prot_op = ses->prot_op;
998}
999EXPORT_SYMBOL(scsi_eh_restore_cmnd);
1000
1001/**
1002 * scsi_send_eh_cmnd - submit a scsi command as part of error recovery
1003 * @scmd: SCSI command structure to hijack
1004 * @cmnd: CDB to send
1005 * @cmnd_size: size in bytes of @cmnd
1006 * @timeout: timeout for this request
1007 * @sense_bytes: size of sense data to copy or 0
1008 *
1009 * This function is used to send a scsi command down to a target device
1010 * as part of the error recovery process. See also scsi_eh_prep_cmnd() above.
1011 *
1012 * Return value:
1013 * SUCCESS or FAILED or NEEDS_RETRY
1014 */
1015static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
1016 int cmnd_size, int timeout, unsigned sense_bytes)
1017{
1018 struct scsi_device *sdev = scmd->device;
1019 struct Scsi_Host *shost = sdev->host;
1020 DECLARE_COMPLETION_ONSTACK(done);
1021 unsigned long timeleft = timeout;
1022 struct scsi_eh_save ses;
1023 const unsigned long stall_for = msecs_to_jiffies(100);
1024 int rtn;
1025
1026retry:
1027 scsi_eh_prep_cmnd(scmd, &ses, cmnd, cmnd_size, sense_bytes);
1028 shost->eh_action = &done;
1029
1030 scsi_log_send(scmd);
1031 scmd->scsi_done = scsi_eh_done;
1032 rtn = shost->hostt->queuecommand(shost, scmd);
1033 if (rtn) {
1034 if (timeleft > stall_for) {
1035 scsi_eh_restore_cmnd(scmd, &ses);
1036 timeleft -= stall_for;
1037 msleep(jiffies_to_msecs(stall_for));
1038 goto retry;
1039 }
1040 /* signal not to enter either branch of the if () below */
1041 timeleft = 0;
1042 rtn = FAILED;
1043 } else {
1044 timeleft = wait_for_completion_timeout(&done, timeout);
1045 rtn = SUCCESS;
1046 }
1047
1048 shost->eh_action = NULL;
1049
1050 scsi_log_completion(scmd, rtn);
1051
1052 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1053 "%s timeleft: %ld\n",
1054 __func__, timeleft));
1055
1056 /*
1057 * If there is time left scsi_eh_done got called, and we will examine
1058 * the actual status codes to see whether the command actually did
1059 * complete normally, else if we have a zero return and no time left,
1060 * the command must still be pending, so abort it and return FAILED.
1061 * If we never actually managed to issue the command, because
1062 * ->queuecommand() kept returning non zero, use the rtn = FAILED
1063 * value above (so don't execute either branch of the if)
1064 */
1065 if (timeleft) {
1066 rtn = scsi_eh_completed_normally(scmd);
1067 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1068 "%s: scsi_eh_completed_normally %x\n", __func__, rtn));
1069
1070 switch (rtn) {
1071 case SUCCESS:
1072 case NEEDS_RETRY:
1073 case FAILED:
1074 break;
1075 case ADD_TO_MLQUEUE:
1076 rtn = NEEDS_RETRY;
1077 break;
1078 default:
1079 rtn = FAILED;
1080 break;
1081 }
1082 } else if (rtn != FAILED) {
1083 scsi_abort_eh_cmnd(scmd);
1084 rtn = FAILED;
1085 }
1086
1087 scsi_eh_restore_cmnd(scmd, &ses);
1088
1089 return rtn;
1090}
1091
1092/**
1093 * scsi_request_sense - Request sense data from a particular target.
1094 * @scmd: SCSI cmd for request sense.
1095 *
1096 * Notes:
1097 * Some hosts automatically obtain this information, others require
1098 * that we obtain it on our own. This function will *not* return until
1099 * the command either times out, or it completes.
1100 */
1101static int scsi_request_sense(struct scsi_cmnd *scmd)
1102{
1103 return scsi_send_eh_cmnd(scmd, NULL, 0, scmd->device->eh_timeout, ~0);
1104}
1105
1106static int scsi_eh_action(struct scsi_cmnd *scmd, int rtn)
1107{
1108 if (scmd->request->cmd_type != REQ_TYPE_BLOCK_PC) {
1109 struct scsi_driver *sdrv = scsi_cmd_to_driver(scmd);
1110 if (sdrv->eh_action)
1111 rtn = sdrv->eh_action(scmd, rtn);
1112 }
1113 return rtn;
1114}
1115
1116/**
1117 * scsi_eh_finish_cmd - Handle a cmd that eh is finished with.
1118 * @scmd: Original SCSI cmd that eh has finished.
1119 * @done_q: Queue for processed commands.
1120 *
1121 * Notes:
1122 * We don't want to use the normal command completion while we are are
1123 * still handling errors - it may cause other commands to be queued,
1124 * and that would disturb what we are doing. Thus we really want to
1125 * keep a list of pending commands for final completion, and once we
1126 * are ready to leave error handling we handle completion for real.
1127 */
1128void scsi_eh_finish_cmd(struct scsi_cmnd *scmd, struct list_head *done_q)
1129{
1130 scmd->device->host->host_failed--;
1131 scmd->eh_eflags = 0;
1132 list_move_tail(&scmd->eh_entry, done_q);
1133}
1134EXPORT_SYMBOL(scsi_eh_finish_cmd);
1135
1136/**
1137 * scsi_eh_get_sense - Get device sense data.
1138 * @work_q: Queue of commands to process.
1139 * @done_q: Queue of processed commands.
1140 *
1141 * Description:
1142 * See if we need to request sense information. if so, then get it
1143 * now, so we have a better idea of what to do.
1144 *
1145 * Notes:
1146 * This has the unfortunate side effect that if a shost adapter does
1147 * not automatically request sense information, we end up shutting
1148 * it down before we request it.
1149 *
1150 * All drivers should request sense information internally these days,
1151 * so for now all I have to say is tough noogies if you end up in here.
1152 *
1153 * XXX: Long term this code should go away, but that needs an audit of
1154 * all LLDDs first.
1155 */
1156int scsi_eh_get_sense(struct list_head *work_q,
1157 struct list_head *done_q)
1158{
1159 struct scsi_cmnd *scmd, *next;
1160 struct Scsi_Host *shost;
1161 int rtn;
1162
1163 /*
1164 * If SCSI_EH_ABORT_SCHEDULED has been set, it is timeout IO,
1165 * should not get sense.
1166 */
1167 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1168 if ((scmd->eh_eflags & SCSI_EH_CANCEL_CMD) ||
1169 (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) ||
1170 SCSI_SENSE_VALID(scmd))
1171 continue;
1172
1173 shost = scmd->device->host;
1174 if (scsi_host_eh_past_deadline(shost)) {
1175 SCSI_LOG_ERROR_RECOVERY(3,
1176 scmd_printk(KERN_INFO, scmd,
1177 "%s: skip request sense, past eh deadline\n",
1178 current->comm));
1179 break;
1180 }
1181 if (status_byte(scmd->result) != CHECK_CONDITION)
1182 /*
1183 * don't request sense if there's no check condition
1184 * status because the error we're processing isn't one
1185 * that has a sense code (and some devices get
1186 * confused by sense requests out of the blue)
1187 */
1188 continue;
1189
1190 SCSI_LOG_ERROR_RECOVERY(2, scmd_printk(KERN_INFO, scmd,
1191 "%s: requesting sense\n",
1192 current->comm));
1193 rtn = scsi_request_sense(scmd);
1194 if (rtn != SUCCESS)
1195 continue;
1196
1197 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1198 "sense requested, result %x\n", scmd->result));
1199 SCSI_LOG_ERROR_RECOVERY(3, scsi_print_sense(scmd));
1200
1201 rtn = scsi_decide_disposition(scmd);
1202
1203 /*
1204 * if the result was normal, then just pass it along to the
1205 * upper level.
1206 */
1207 if (rtn == SUCCESS)
1208 /* we don't want this command reissued, just
1209 * finished with the sense data, so set
1210 * retries to the max allowed to ensure it
1211 * won't get reissued */
1212 scmd->retries = scmd->allowed;
1213 else if (rtn != NEEDS_RETRY)
1214 continue;
1215
1216 scsi_eh_finish_cmd(scmd, done_q);
1217 }
1218
1219 return list_empty(work_q);
1220}
1221EXPORT_SYMBOL_GPL(scsi_eh_get_sense);
1222
1223/**
1224 * scsi_eh_tur - Send TUR to device.
1225 * @scmd: &scsi_cmnd to send TUR
1226 *
1227 * Return value:
1228 * 0 - Device is ready. 1 - Device NOT ready.
1229 */
1230static int scsi_eh_tur(struct scsi_cmnd *scmd)
1231{
1232 static unsigned char tur_command[6] = {TEST_UNIT_READY, 0, 0, 0, 0, 0};
1233 int retry_cnt = 1, rtn;
1234
1235retry_tur:
1236 rtn = scsi_send_eh_cmnd(scmd, tur_command, 6,
1237 scmd->device->eh_timeout, 0);
1238
1239 SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1240 "%s return: %x\n", __func__, rtn));
1241
1242 switch (rtn) {
1243 case NEEDS_RETRY:
1244 if (retry_cnt--)
1245 goto retry_tur;
1246 /*FALLTHRU*/
1247 case SUCCESS:
1248 return 0;
1249 default:
1250 return 1;
1251 }
1252}
1253
1254/**
1255 * scsi_eh_test_devices - check if devices are responding from error recovery.
1256 * @cmd_list: scsi commands in error recovery.
1257 * @work_q: queue for commands which still need more error recovery
1258 * @done_q: queue for commands which are finished
1259 * @try_stu: boolean on if a STU command should be tried in addition to TUR.
1260 *
1261 * Decription:
1262 * Tests if devices are in a working state. Commands to devices now in
1263 * a working state are sent to the done_q while commands to devices which
1264 * are still failing to respond are returned to the work_q for more
1265 * processing.
1266 **/
1267static int scsi_eh_test_devices(struct list_head *cmd_list,
1268 struct list_head *work_q,
1269 struct list_head *done_q, int try_stu)
1270{
1271 struct scsi_cmnd *scmd, *next;
1272 struct scsi_device *sdev;
1273 int finish_cmds;
1274
1275 while (!list_empty(cmd_list)) {
1276 scmd = list_entry(cmd_list->next, struct scsi_cmnd, eh_entry);
1277 sdev = scmd->device;
1278
1279 if (!try_stu) {
1280 if (scsi_host_eh_past_deadline(sdev->host)) {
1281 /* Push items back onto work_q */
1282 list_splice_init(cmd_list, work_q);
1283 SCSI_LOG_ERROR_RECOVERY(3,
1284 sdev_printk(KERN_INFO, sdev,
1285 "%s: skip test device, past eh deadline",
1286 current->comm));
1287 break;
1288 }
1289 }
1290
1291 finish_cmds = !scsi_device_online(scmd->device) ||
1292 (try_stu && !scsi_eh_try_stu(scmd) &&
1293 !scsi_eh_tur(scmd)) ||
1294 !scsi_eh_tur(scmd);
1295
1296 list_for_each_entry_safe(scmd, next, cmd_list, eh_entry)
1297 if (scmd->device == sdev) {
1298 if (finish_cmds &&
1299 (try_stu ||
1300 scsi_eh_action(scmd, SUCCESS) == SUCCESS))
1301 scsi_eh_finish_cmd(scmd, done_q);
1302 else
1303 list_move_tail(&scmd->eh_entry, work_q);
1304 }
1305 }
1306 return list_empty(work_q);
1307}
1308
1309
1310/**
1311 * scsi_eh_abort_cmds - abort pending commands.
1312 * @work_q: &list_head for pending commands.
1313 * @done_q: &list_head for processed commands.
1314 *
1315 * Decription:
1316 * Try and see whether or not it makes sense to try and abort the
1317 * running command. This only works out to be the case if we have one
1318 * command that has timed out. If the command simply failed, it makes
1319 * no sense to try and abort the command, since as far as the shost
1320 * adapter is concerned, it isn't running.
1321 */
1322static int scsi_eh_abort_cmds(struct list_head *work_q,
1323 struct list_head *done_q)
1324{
1325 struct scsi_cmnd *scmd, *next;
1326 LIST_HEAD(check_list);
1327 int rtn;
1328 struct Scsi_Host *shost;
1329
1330 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1331 if (!(scmd->eh_eflags & SCSI_EH_CANCEL_CMD))
1332 continue;
1333 shost = scmd->device->host;
1334 if (scsi_host_eh_past_deadline(shost)) {
1335 list_splice_init(&check_list, work_q);
1336 SCSI_LOG_ERROR_RECOVERY(3,
1337 scmd_printk(KERN_INFO, scmd,
1338 "%s: skip aborting cmd, past eh deadline\n",
1339 current->comm));
1340 return list_empty(work_q);
1341 }
1342 SCSI_LOG_ERROR_RECOVERY(3,
1343 scmd_printk(KERN_INFO, scmd,
1344 "%s: aborting cmd\n", current->comm));
1345 rtn = scsi_try_to_abort_cmd(shost->hostt, scmd);
1346 if (rtn == FAILED) {
1347 SCSI_LOG_ERROR_RECOVERY(3,
1348 scmd_printk(KERN_INFO, scmd,
1349 "%s: aborting cmd failed\n",
1350 current->comm));
1351 list_splice_init(&check_list, work_q);
1352 return list_empty(work_q);
1353 }
1354 scmd->eh_eflags &= ~SCSI_EH_CANCEL_CMD;
1355 if (rtn == FAST_IO_FAIL)
1356 scsi_eh_finish_cmd(scmd, done_q);
1357 else
1358 list_move_tail(&scmd->eh_entry, &check_list);
1359 }
1360
1361 return scsi_eh_test_devices(&check_list, work_q, done_q, 0);
1362}
1363
1364/**
1365 * scsi_eh_try_stu - Send START_UNIT to device.
1366 * @scmd: &scsi_cmnd to send START_UNIT
1367 *
1368 * Return value:
1369 * 0 - Device is ready. 1 - Device NOT ready.
1370 */
1371static int scsi_eh_try_stu(struct scsi_cmnd *scmd)
1372{
1373 static unsigned char stu_command[6] = {START_STOP, 0, 0, 0, 1, 0};
1374
1375 if (scmd->device->allow_restart) {
1376 int i, rtn = NEEDS_RETRY;
1377
1378 for (i = 0; rtn == NEEDS_RETRY && i < 2; i++)
1379 rtn = scsi_send_eh_cmnd(scmd, stu_command, 6, scmd->device->request_queue->rq_timeout, 0);
1380
1381 if (rtn == SUCCESS)
1382 return 0;
1383 }
1384
1385 return 1;
1386}
1387
1388 /**
1389 * scsi_eh_stu - send START_UNIT if needed
1390 * @shost: &scsi host being recovered.
1391 * @work_q: &list_head for pending commands.
1392 * @done_q: &list_head for processed commands.
1393 *
1394 * Notes:
1395 * If commands are failing due to not ready, initializing command required,
1396 * try revalidating the device, which will end up sending a start unit.
1397 */
1398static int scsi_eh_stu(struct Scsi_Host *shost,
1399 struct list_head *work_q,
1400 struct list_head *done_q)
1401{
1402 struct scsi_cmnd *scmd, *stu_scmd, *next;
1403 struct scsi_device *sdev;
1404
1405 shost_for_each_device(sdev, shost) {
1406 if (scsi_host_eh_past_deadline(shost)) {
1407 SCSI_LOG_ERROR_RECOVERY(3,
1408 sdev_printk(KERN_INFO, sdev,
1409 "%s: skip START_UNIT, past eh deadline\n",
1410 current->comm));
1411 break;
1412 }
1413 stu_scmd = NULL;
1414 list_for_each_entry(scmd, work_q, eh_entry)
1415 if (scmd->device == sdev && SCSI_SENSE_VALID(scmd) &&
1416 scsi_check_sense(scmd) == FAILED ) {
1417 stu_scmd = scmd;
1418 break;
1419 }
1420
1421 if (!stu_scmd)
1422 continue;
1423
1424 SCSI_LOG_ERROR_RECOVERY(3,
1425 sdev_printk(KERN_INFO, sdev,
1426 "%s: Sending START_UNIT\n",
1427 current->comm));
1428
1429 if (!scsi_eh_try_stu(stu_scmd)) {
1430 if (!scsi_device_online(sdev) ||
1431 !scsi_eh_tur(stu_scmd)) {
1432 list_for_each_entry_safe(scmd, next,
1433 work_q, eh_entry) {
1434 if (scmd->device == sdev &&
1435 scsi_eh_action(scmd, SUCCESS) == SUCCESS)
1436 scsi_eh_finish_cmd(scmd, done_q);
1437 }
1438 }
1439 } else {
1440 SCSI_LOG_ERROR_RECOVERY(3,
1441 sdev_printk(KERN_INFO, sdev,
1442 "%s: START_UNIT failed\n",
1443 current->comm));
1444 }
1445 }
1446
1447 return list_empty(work_q);
1448}
1449
1450
1451/**
1452 * scsi_eh_bus_device_reset - send bdr if needed
1453 * @shost: scsi host being recovered.
1454 * @work_q: &list_head for pending commands.
1455 * @done_q: &list_head for processed commands.
1456 *
1457 * Notes:
1458 * Try a bus device reset. Still, look to see whether we have multiple
1459 * devices that are jammed or not - if we have multiple devices, it
1460 * makes no sense to try bus_device_reset - we really would need to try
1461 * a bus_reset instead.
1462 */
1463static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
1464 struct list_head *work_q,
1465 struct list_head *done_q)
1466{
1467 struct scsi_cmnd *scmd, *bdr_scmd, *next;
1468 struct scsi_device *sdev;
1469 int rtn;
1470
1471 shost_for_each_device(sdev, shost) {
1472 if (scsi_host_eh_past_deadline(shost)) {
1473 SCSI_LOG_ERROR_RECOVERY(3,
1474 sdev_printk(KERN_INFO, sdev,
1475 "%s: skip BDR, past eh deadline\n",
1476 current->comm));
1477 break;
1478 }
1479 bdr_scmd = NULL;
1480 list_for_each_entry(scmd, work_q, eh_entry)
1481 if (scmd->device == sdev) {
1482 bdr_scmd = scmd;
1483 break;
1484 }
1485
1486 if (!bdr_scmd)
1487 continue;
1488
1489 SCSI_LOG_ERROR_RECOVERY(3,
1490 sdev_printk(KERN_INFO, sdev,
1491 "%s: Sending BDR\n", current->comm));
1492 rtn = scsi_try_bus_device_reset(bdr_scmd);
1493 if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
1494 if (!scsi_device_online(sdev) ||
1495 rtn == FAST_IO_FAIL ||
1496 !scsi_eh_tur(bdr_scmd)) {
1497 list_for_each_entry_safe(scmd, next,
1498 work_q, eh_entry) {
1499 if (scmd->device == sdev &&
1500 scsi_eh_action(scmd, rtn) != FAILED)
1501 scsi_eh_finish_cmd(scmd,
1502 done_q);
1503 }
1504 }
1505 } else {
1506 SCSI_LOG_ERROR_RECOVERY(3,
1507 sdev_printk(KERN_INFO, sdev,
1508 "%s: BDR failed\n", current->comm));
1509 }
1510 }
1511
1512 return list_empty(work_q);
1513}
1514
1515/**
1516 * scsi_eh_target_reset - send target reset if needed
1517 * @shost: scsi host being recovered.
1518 * @work_q: &list_head for pending commands.
1519 * @done_q: &list_head for processed commands.
1520 *
1521 * Notes:
1522 * Try a target reset.
1523 */
1524static int scsi_eh_target_reset(struct Scsi_Host *shost,
1525 struct list_head *work_q,
1526 struct list_head *done_q)
1527{
1528 LIST_HEAD(tmp_list);
1529 LIST_HEAD(check_list);
1530
1531 list_splice_init(work_q, &tmp_list);
1532
1533 while (!list_empty(&tmp_list)) {
1534 struct scsi_cmnd *next, *scmd;
1535 int rtn;
1536 unsigned int id;
1537
1538 if (scsi_host_eh_past_deadline(shost)) {
1539 /* push back on work queue for further processing */
1540 list_splice_init(&check_list, work_q);
1541 list_splice_init(&tmp_list, work_q);
1542 SCSI_LOG_ERROR_RECOVERY(3,
1543 shost_printk(KERN_INFO, shost,
1544 "%s: Skip target reset, past eh deadline\n",
1545 current->comm));
1546 return list_empty(work_q);
1547 }
1548
1549 scmd = list_entry(tmp_list.next, struct scsi_cmnd, eh_entry);
1550 id = scmd_id(scmd);
1551
1552 SCSI_LOG_ERROR_RECOVERY(3,
1553 shost_printk(KERN_INFO, shost,
1554 "%s: Sending target reset to target %d\n",
1555 current->comm, id));
1556 rtn = scsi_try_target_reset(scmd);
1557 if (rtn != SUCCESS && rtn != FAST_IO_FAIL)
1558 SCSI_LOG_ERROR_RECOVERY(3,
1559 shost_printk(KERN_INFO, shost,
1560 "%s: Target reset failed"
1561 " target: %d\n",
1562 current->comm, id));
1563 list_for_each_entry_safe(scmd, next, &tmp_list, eh_entry) {
1564 if (scmd_id(scmd) != id)
1565 continue;
1566
1567 if (rtn == SUCCESS)
1568 list_move_tail(&scmd->eh_entry, &check_list);
1569 else if (rtn == FAST_IO_FAIL)
1570 scsi_eh_finish_cmd(scmd, done_q);
1571 else
1572 /* push back on work queue for further processing */
1573 list_move(&scmd->eh_entry, work_q);
1574 }
1575 }
1576
1577 return scsi_eh_test_devices(&check_list, work_q, done_q, 0);
1578}
1579
1580/**
1581 * scsi_eh_bus_reset - send a bus reset
1582 * @shost: &scsi host being recovered.
1583 * @work_q: &list_head for pending commands.
1584 * @done_q: &list_head for processed commands.
1585 */
1586static int scsi_eh_bus_reset(struct Scsi_Host *shost,
1587 struct list_head *work_q,
1588 struct list_head *done_q)
1589{
1590 struct scsi_cmnd *scmd, *chan_scmd, *next;
1591 LIST_HEAD(check_list);
1592 unsigned int channel;
1593 int rtn;
1594
1595 /*
1596 * we really want to loop over the various channels, and do this on
1597 * a channel by channel basis. we should also check to see if any
1598 * of the failed commands are on soft_reset devices, and if so, skip
1599 * the reset.
1600 */
1601
1602 for (channel = 0; channel <= shost->max_channel; channel++) {
1603 if (scsi_host_eh_past_deadline(shost)) {
1604 list_splice_init(&check_list, work_q);
1605 SCSI_LOG_ERROR_RECOVERY(3,
1606 shost_printk(KERN_INFO, shost,
1607 "%s: skip BRST, past eh deadline\n",
1608 current->comm));
1609 return list_empty(work_q);
1610 }
1611
1612 chan_scmd = NULL;
1613 list_for_each_entry(scmd, work_q, eh_entry) {
1614 if (channel == scmd_channel(scmd)) {
1615 chan_scmd = scmd;
1616 break;
1617 /*
1618 * FIXME add back in some support for
1619 * soft_reset devices.
1620 */
1621 }
1622 }
1623
1624 if (!chan_scmd)
1625 continue;
1626 SCSI_LOG_ERROR_RECOVERY(3,
1627 shost_printk(KERN_INFO, shost,
1628 "%s: Sending BRST chan: %d\n",
1629 current->comm, channel));
1630 rtn = scsi_try_bus_reset(chan_scmd);
1631 if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
1632 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1633 if (channel == scmd_channel(scmd)) {
1634 if (rtn == FAST_IO_FAIL)
1635 scsi_eh_finish_cmd(scmd,
1636 done_q);
1637 else
1638 list_move_tail(&scmd->eh_entry,
1639 &check_list);
1640 }
1641 }
1642 } else {
1643 SCSI_LOG_ERROR_RECOVERY(3,
1644 shost_printk(KERN_INFO, shost,
1645 "%s: BRST failed chan: %d\n",
1646 current->comm, channel));
1647 }
1648 }
1649 return scsi_eh_test_devices(&check_list, work_q, done_q, 0);
1650}
1651
1652/**
1653 * scsi_eh_host_reset - send a host reset
1654 * @shost: host to be reset.
1655 * @work_q: &list_head for pending commands.
1656 * @done_q: &list_head for processed commands.
1657 */
1658static int scsi_eh_host_reset(struct Scsi_Host *shost,
1659 struct list_head *work_q,
1660 struct list_head *done_q)
1661{
1662 struct scsi_cmnd *scmd, *next;
1663 LIST_HEAD(check_list);
1664 int rtn;
1665
1666 if (!list_empty(work_q)) {
1667 scmd = list_entry(work_q->next,
1668 struct scsi_cmnd, eh_entry);
1669
1670 SCSI_LOG_ERROR_RECOVERY(3,
1671 shost_printk(KERN_INFO, shost,
1672 "%s: Sending HRST\n",
1673 current->comm));
1674
1675 rtn = scsi_try_host_reset(scmd);
1676 if (rtn == SUCCESS) {
1677 list_splice_init(work_q, &check_list);
1678 } else if (rtn == FAST_IO_FAIL) {
1679 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1680 scsi_eh_finish_cmd(scmd, done_q);
1681 }
1682 } else {
1683 SCSI_LOG_ERROR_RECOVERY(3,
1684 shost_printk(KERN_INFO, shost,
1685 "%s: HRST failed\n",
1686 current->comm));
1687 }
1688 }
1689 return scsi_eh_test_devices(&check_list, work_q, done_q, 1);
1690}
1691
1692/**
1693 * scsi_eh_offline_sdevs - offline scsi devices that fail to recover
1694 * @work_q: &list_head for pending commands.
1695 * @done_q: &list_head for processed commands.
1696 */
1697static void scsi_eh_offline_sdevs(struct list_head *work_q,
1698 struct list_head *done_q)
1699{
1700 struct scsi_cmnd *scmd, *next;
1701
1702 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1703 sdev_printk(KERN_INFO, scmd->device, "Device offlined - "
1704 "not ready after error recovery\n");
1705 scsi_device_set_state(scmd->device, SDEV_OFFLINE);
1706 if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD) {
1707 /*
1708 * FIXME: Handle lost cmds.
1709 */
1710 }
1711 scsi_eh_finish_cmd(scmd, done_q);
1712 }
1713 return;
1714}
1715
1716/**
1717 * scsi_noretry_cmd - determine if command should be failed fast
1718 * @scmd: SCSI cmd to examine.
1719 */
1720int scsi_noretry_cmd(struct scsi_cmnd *scmd)
1721{
1722 switch (host_byte(scmd->result)) {
1723 case DID_OK:
1724 break;
1725 case DID_TIME_OUT:
1726 goto check_type;
1727 case DID_BUS_BUSY:
1728 return (scmd->request->cmd_flags & REQ_FAILFAST_TRANSPORT);
1729 case DID_PARITY:
1730 return (scmd->request->cmd_flags & REQ_FAILFAST_DEV);
1731 case DID_ERROR:
1732 if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
1733 status_byte(scmd->result) == RESERVATION_CONFLICT)
1734 return 0;
1735 /* fall through */
1736 case DID_SOFT_ERROR:
1737 return (scmd->request->cmd_flags & REQ_FAILFAST_DRIVER);
1738 }
1739
1740 if (status_byte(scmd->result) != CHECK_CONDITION)
1741 return 0;
1742
1743check_type:
1744 /*
1745 * assume caller has checked sense and determined
1746 * the check condition was retryable.
1747 */
1748 if (scmd->request->cmd_flags & REQ_FAILFAST_DEV ||
1749 scmd->request->cmd_type == REQ_TYPE_BLOCK_PC)
1750 return 1;
1751 else
1752 return 0;
1753}
1754
1755/**
1756 * scsi_decide_disposition - Disposition a cmd on return from LLD.
1757 * @scmd: SCSI cmd to examine.
1758 *
1759 * Notes:
1760 * This is *only* called when we are examining the status after sending
1761 * out the actual data command. any commands that are queued for error
1762 * recovery (e.g. test_unit_ready) do *not* come through here.
1763 *
1764 * When this routine returns failed, it means the error handler thread
1765 * is woken. In cases where the error code indicates an error that
1766 * doesn't require the error handler read (i.e. we don't need to
1767 * abort/reset), this function should return SUCCESS.
1768 */
1769int scsi_decide_disposition(struct scsi_cmnd *scmd)
1770{
1771 int rtn;
1772
1773 /*
1774 * if the device is offline, then we clearly just pass the result back
1775 * up to the top level.
1776 */
1777 if (!scsi_device_online(scmd->device)) {
1778 SCSI_LOG_ERROR_RECOVERY(5, scmd_printk(KERN_INFO, scmd,
1779 "%s: device offline - report as SUCCESS\n", __func__));
1780 return SUCCESS;
1781 }
1782
1783 /*
1784 * first check the host byte, to see if there is anything in there
1785 * that would indicate what we need to do.
1786 */
1787 switch (host_byte(scmd->result)) {
1788 case DID_PASSTHROUGH:
1789 /*
1790 * no matter what, pass this through to the upper layer.
1791 * nuke this special code so that it looks like we are saying
1792 * did_ok.
1793 */
1794 scmd->result &= 0xff00ffff;
1795 return SUCCESS;
1796 case DID_OK:
1797 /*
1798 * looks good. drop through, and check the next byte.
1799 */
1800 break;
1801 case DID_ABORT:
1802 if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) {
1803 set_host_byte(scmd, DID_TIME_OUT);
1804 return SUCCESS;
1805 }
1806 case DID_NO_CONNECT:
1807 case DID_BAD_TARGET:
1808 /*
1809 * note - this means that we just report the status back
1810 * to the top level driver, not that we actually think
1811 * that it indicates SUCCESS.
1812 */
1813 return SUCCESS;
1814 /*
1815 * when the low level driver returns did_soft_error,
1816 * it is responsible for keeping an internal retry counter
1817 * in order to avoid endless loops (db)
1818 *
1819 * actually this is a bug in this function here. we should
1820 * be mindful of the maximum number of retries specified
1821 * and not get stuck in a loop.
1822 */
1823 case DID_SOFT_ERROR:
1824 goto maybe_retry;
1825 case DID_IMM_RETRY:
1826 return NEEDS_RETRY;
1827
1828 case DID_REQUEUE:
1829 return ADD_TO_MLQUEUE;
1830 case DID_TRANSPORT_DISRUPTED:
1831 /*
1832 * LLD/transport was disrupted during processing of the IO.
1833 * The transport class is now blocked/blocking,
1834 * and the transport will decide what to do with the IO
1835 * based on its timers and recovery capablilities if
1836 * there are enough retries.
1837 */
1838 goto maybe_retry;
1839 case DID_TRANSPORT_FAILFAST:
1840 /*
1841 * The transport decided to failfast the IO (most likely
1842 * the fast io fail tmo fired), so send IO directly upwards.
1843 */
1844 return SUCCESS;
1845 case DID_ERROR:
1846 if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
1847 status_byte(scmd->result) == RESERVATION_CONFLICT)
1848 /*
1849 * execute reservation conflict processing code
1850 * lower down
1851 */
1852 break;
1853 /* fallthrough */
1854 case DID_BUS_BUSY:
1855 case DID_PARITY:
1856 goto maybe_retry;
1857 case DID_TIME_OUT:
1858 /*
1859 * when we scan the bus, we get timeout messages for
1860 * these commands if there is no device available.
1861 * other hosts report did_no_connect for the same thing.
1862 */
1863 if ((scmd->cmnd[0] == TEST_UNIT_READY ||
1864 scmd->cmnd[0] == INQUIRY)) {
1865 return SUCCESS;
1866 } else {
1867 return FAILED;
1868 }
1869 case DID_RESET:
1870 return SUCCESS;
1871 default:
1872 return FAILED;
1873 }
1874
1875 /*
1876 * next, check the message byte.
1877 */
1878 if (msg_byte(scmd->result) != COMMAND_COMPLETE)
1879 return FAILED;
1880
1881 /*
1882 * check the status byte to see if this indicates anything special.
1883 */
1884 switch (status_byte(scmd->result)) {
1885 case QUEUE_FULL:
1886 scsi_handle_queue_full(scmd->device);
1887 /*
1888 * the case of trying to send too many commands to a
1889 * tagged queueing device.
1890 */
1891 case BUSY:
1892 /*
1893 * device can't talk to us at the moment. Should only
1894 * occur (SAM-3) when the task queue is empty, so will cause
1895 * the empty queue handling to trigger a stall in the
1896 * device.
1897 */
1898 return ADD_TO_MLQUEUE;
1899 case GOOD:
1900 if (scmd->cmnd[0] == REPORT_LUNS)
1901 scmd->device->sdev_target->expecting_lun_change = 0;
1902 scsi_handle_queue_ramp_up(scmd->device);
1903 case COMMAND_TERMINATED:
1904 return SUCCESS;
1905 case TASK_ABORTED:
1906 goto maybe_retry;
1907 case CHECK_CONDITION:
1908 rtn = scsi_check_sense(scmd);
1909 if (rtn == NEEDS_RETRY)
1910 goto maybe_retry;
1911 /* if rtn == FAILED, we have no sense information;
1912 * returning FAILED will wake the error handler thread
1913 * to collect the sense and redo the decide
1914 * disposition */
1915 return rtn;
1916 case CONDITION_GOOD:
1917 case INTERMEDIATE_GOOD:
1918 case INTERMEDIATE_C_GOOD:
1919 case ACA_ACTIVE:
1920 /*
1921 * who knows? FIXME(eric)
1922 */
1923 return SUCCESS;
1924
1925 case RESERVATION_CONFLICT:
1926 sdev_printk(KERN_INFO, scmd->device,
1927 "reservation conflict\n");
1928 set_host_byte(scmd, DID_NEXUS_FAILURE);
1929 return SUCCESS; /* causes immediate i/o error */
1930 default:
1931 return FAILED;
1932 }
1933 return FAILED;
1934
1935 maybe_retry:
1936
1937 /* we requeue for retry because the error was retryable, and
1938 * the request was not marked fast fail. Note that above,
1939 * even if the request is marked fast fail, we still requeue
1940 * for queue congestion conditions (QUEUE_FULL or BUSY) */
1941 if ((++scmd->retries) <= scmd->allowed
1942 && !scsi_noretry_cmd(scmd)) {
1943 return NEEDS_RETRY;
1944 } else {
1945 /*
1946 * no more retries - report this one back to upper level.
1947 */
1948 return SUCCESS;
1949 }
1950}
1951
1952static void eh_lock_door_done(struct request *req, int uptodate)
1953{
1954 __blk_put_request(req->q, req);
1955}
1956
1957/**
1958 * scsi_eh_lock_door - Prevent medium removal for the specified device
1959 * @sdev: SCSI device to prevent medium removal
1960 *
1961 * Locking:
1962 * We must be called from process context.
1963 *
1964 * Notes:
1965 * We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the
1966 * head of the devices request queue, and continue.
1967 */
1968static void scsi_eh_lock_door(struct scsi_device *sdev)
1969{
1970 struct request *req;
1971
1972 /*
1973 * blk_get_request with GFP_KERNEL (__GFP_RECLAIM) sleeps until a
1974 * request becomes available
1975 */
1976 req = blk_get_request(sdev->request_queue, READ, GFP_KERNEL);
1977 if (IS_ERR(req))
1978 return;
1979
1980 blk_rq_set_block_pc(req);
1981
1982 req->cmd[0] = ALLOW_MEDIUM_REMOVAL;
1983 req->cmd[1] = 0;
1984 req->cmd[2] = 0;
1985 req->cmd[3] = 0;
1986 req->cmd[4] = SCSI_REMOVAL_PREVENT;
1987 req->cmd[5] = 0;
1988
1989 req->cmd_len = COMMAND_SIZE(req->cmd[0]);
1990
1991 req->cmd_flags |= REQ_QUIET;
1992 req->timeout = 10 * HZ;
1993 req->retries = 5;
1994
1995 blk_execute_rq_nowait(req->q, NULL, req, 1, eh_lock_door_done);
1996}
1997
1998/**
1999 * scsi_restart_operations - restart io operations to the specified host.
2000 * @shost: Host we are restarting.
2001 *
2002 * Notes:
2003 * When we entered the error handler, we blocked all further i/o to
2004 * this device. we need to 'reverse' this process.
2005 */
2006static void scsi_restart_operations(struct Scsi_Host *shost)
2007{
2008 struct scsi_device *sdev;
2009 unsigned long flags;
2010
2011 /*
2012 * If the door was locked, we need to insert a door lock request
2013 * onto the head of the SCSI request queue for the device. There
2014 * is no point trying to lock the door of an off-line device.
2015 */
2016 shost_for_each_device(sdev, shost) {
2017 if (scsi_device_online(sdev) && sdev->was_reset && sdev->locked) {
2018 scsi_eh_lock_door(sdev);
2019 sdev->was_reset = 0;
2020 }
2021 }
2022
2023 /*
2024 * next free up anything directly waiting upon the host. this
2025 * will be requests for character device operations, and also for
2026 * ioctls to queued block devices.
2027 */
2028 SCSI_LOG_ERROR_RECOVERY(3,
2029 shost_printk(KERN_INFO, shost, "waking up host to restart\n"));
2030
2031 spin_lock_irqsave(shost->host_lock, flags);
2032 if (scsi_host_set_state(shost, SHOST_RUNNING))
2033 if (scsi_host_set_state(shost, SHOST_CANCEL))
2034 BUG_ON(scsi_host_set_state(shost, SHOST_DEL));
2035 spin_unlock_irqrestore(shost->host_lock, flags);
2036
2037 wake_up(&shost->host_wait);
2038
2039 /*
2040 * finally we need to re-initiate requests that may be pending. we will
2041 * have had everything blocked while error handling is taking place, and
2042 * now that error recovery is done, we will need to ensure that these
2043 * requests are started.
2044 */
2045 scsi_run_host_queues(shost);
2046
2047 /*
2048 * if eh is active and host_eh_scheduled is pending we need to re-run
2049 * recovery. we do this check after scsi_run_host_queues() to allow
2050 * everything pent up since the last eh run a chance to make forward
2051 * progress before we sync again. Either we'll immediately re-run
2052 * recovery or scsi_device_unbusy() will wake us again when these
2053 * pending commands complete.
2054 */
2055 spin_lock_irqsave(shost->host_lock, flags);
2056 if (shost->host_eh_scheduled)
2057 if (scsi_host_set_state(shost, SHOST_RECOVERY))
2058 WARN_ON(scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY));
2059 spin_unlock_irqrestore(shost->host_lock, flags);
2060}
2061
2062/**
2063 * scsi_eh_ready_devs - check device ready state and recover if not.
2064 * @shost: host to be recovered.
2065 * @work_q: &list_head for pending commands.
2066 * @done_q: &list_head for processed commands.
2067 */
2068void scsi_eh_ready_devs(struct Scsi_Host *shost,
2069 struct list_head *work_q,
2070 struct list_head *done_q)
2071{
2072 if (!scsi_eh_stu(shost, work_q, done_q))
2073 if (!scsi_eh_bus_device_reset(shost, work_q, done_q))
2074 if (!scsi_eh_target_reset(shost, work_q, done_q))
2075 if (!scsi_eh_bus_reset(shost, work_q, done_q))
2076 if (!scsi_eh_host_reset(shost, work_q, done_q))
2077 scsi_eh_offline_sdevs(work_q,
2078 done_q);
2079}
2080EXPORT_SYMBOL_GPL(scsi_eh_ready_devs);
2081
2082/**
2083 * scsi_eh_flush_done_q - finish processed commands or retry them.
2084 * @done_q: list_head of processed commands.
2085 */
2086void scsi_eh_flush_done_q(struct list_head *done_q)
2087{
2088 struct scsi_cmnd *scmd, *next;
2089
2090 list_for_each_entry_safe(scmd, next, done_q, eh_entry) {
2091 list_del_init(&scmd->eh_entry);
2092 if (scsi_device_online(scmd->device) &&
2093 !scsi_noretry_cmd(scmd) &&
2094 (++scmd->retries <= scmd->allowed)) {
2095 SCSI_LOG_ERROR_RECOVERY(3,
2096 scmd_printk(KERN_INFO, scmd,
2097 "%s: flush retry cmd\n",
2098 current->comm));
2099 scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY);
2100 } else {
2101 /*
2102 * If just we got sense for the device (called
2103 * scsi_eh_get_sense), scmd->result is already
2104 * set, do not set DRIVER_TIMEOUT.
2105 */
2106 if (!scmd->result)
2107 scmd->result |= (DRIVER_TIMEOUT << 24);
2108 SCSI_LOG_ERROR_RECOVERY(3,
2109 scmd_printk(KERN_INFO, scmd,
2110 "%s: flush finish cmd\n",
2111 current->comm));
2112 scsi_finish_command(scmd);
2113 }
2114 }
2115}
2116EXPORT_SYMBOL(scsi_eh_flush_done_q);
2117
2118/**
2119 * scsi_unjam_host - Attempt to fix a host which has a cmd that failed.
2120 * @shost: Host to unjam.
2121 *
2122 * Notes:
2123 * When we come in here, we *know* that all commands on the bus have
2124 * either completed, failed or timed out. we also know that no further
2125 * commands are being sent to the host, so things are relatively quiet
2126 * and we have freedom to fiddle with things as we wish.
2127 *
2128 * This is only the *default* implementation. it is possible for
2129 * individual drivers to supply their own version of this function, and
2130 * if the maintainer wishes to do this, it is strongly suggested that
2131 * this function be taken as a template and modified. this function
2132 * was designed to correctly handle problems for about 95% of the
2133 * different cases out there, and it should always provide at least a
2134 * reasonable amount of error recovery.
2135 *
2136 * Any command marked 'failed' or 'timeout' must eventually have
2137 * scsi_finish_cmd() called for it. we do all of the retry stuff
2138 * here, so when we restart the host after we return it should have an
2139 * empty queue.
2140 */
2141static void scsi_unjam_host(struct Scsi_Host *shost)
2142{
2143 unsigned long flags;
2144 LIST_HEAD(eh_work_q);
2145 LIST_HEAD(eh_done_q);
2146
2147 spin_lock_irqsave(shost->host_lock, flags);
2148 list_splice_init(&shost->eh_cmd_q, &eh_work_q);
2149 spin_unlock_irqrestore(shost->host_lock, flags);
2150
2151 SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(shost, &eh_work_q));
2152
2153 if (!scsi_eh_get_sense(&eh_work_q, &eh_done_q))
2154 if (!scsi_eh_abort_cmds(&eh_work_q, &eh_done_q))
2155 scsi_eh_ready_devs(shost, &eh_work_q, &eh_done_q);
2156
2157 spin_lock_irqsave(shost->host_lock, flags);
2158 if (shost->eh_deadline != -1)
2159 shost->last_reset = 0;
2160 spin_unlock_irqrestore(shost->host_lock, flags);
2161 scsi_eh_flush_done_q(&eh_done_q);
2162}
2163
2164/**
2165 * scsi_error_handler - SCSI error handler thread
2166 * @data: Host for which we are running.
2167 *
2168 * Notes:
2169 * This is the main error handling loop. This is run as a kernel thread
2170 * for every SCSI host and handles all error handling activity.
2171 */
2172int scsi_error_handler(void *data)
2173{
2174 struct Scsi_Host *shost = data;
2175
2176 /*
2177 * We use TASK_INTERRUPTIBLE so that the thread is not
2178 * counted against the load average as a running process.
2179 * We never actually get interrupted because kthread_run
2180 * disables signal delivery for the created thread.
2181 */
2182 while (true) {
2183 /*
2184 * The sequence in kthread_stop() sets the stop flag first
2185 * then wakes the process. To avoid missed wakeups, the task
2186 * should always be in a non running state before the stop
2187 * flag is checked
2188 */
2189 set_current_state(TASK_INTERRUPTIBLE);
2190 if (kthread_should_stop())
2191 break;
2192
2193 if ((shost->host_failed == 0 && shost->host_eh_scheduled == 0) ||
2194 shost->host_failed != atomic_read(&shost->host_busy)) {
2195 SCSI_LOG_ERROR_RECOVERY(1,
2196 shost_printk(KERN_INFO, shost,
2197 "scsi_eh_%d: sleeping\n",
2198 shost->host_no));
2199 schedule();
2200 continue;
2201 }
2202
2203 __set_current_state(TASK_RUNNING);
2204 SCSI_LOG_ERROR_RECOVERY(1,
2205 shost_printk(KERN_INFO, shost,
2206 "scsi_eh_%d: waking up %d/%d/%d\n",
2207 shost->host_no, shost->host_eh_scheduled,
2208 shost->host_failed,
2209 atomic_read(&shost->host_busy)));
2210
2211 /*
2212 * We have a host that is failing for some reason. Figure out
2213 * what we need to do to get it up and online again (if we can).
2214 * If we fail, we end up taking the thing offline.
2215 */
2216 if (!shost->eh_noresume && scsi_autopm_get_host(shost) != 0) {
2217 SCSI_LOG_ERROR_RECOVERY(1,
2218 shost_printk(KERN_ERR, shost,
2219 "scsi_eh_%d: unable to autoresume\n",
2220 shost->host_no));
2221 continue;
2222 }
2223
2224 if (shost->transportt->eh_strategy_handler)
2225 shost->transportt->eh_strategy_handler(shost);
2226 else
2227 scsi_unjam_host(shost);
2228
2229 /*
2230 * Note - if the above fails completely, the action is to take
2231 * individual devices offline and flush the queue of any
2232 * outstanding requests that may have been pending. When we
2233 * restart, we restart any I/O to any other devices on the bus
2234 * which are still online.
2235 */
2236 scsi_restart_operations(shost);
2237 if (!shost->eh_noresume)
2238 scsi_autopm_put_host(shost);
2239 }
2240 __set_current_state(TASK_RUNNING);
2241
2242 SCSI_LOG_ERROR_RECOVERY(1,
2243 shost_printk(KERN_INFO, shost,
2244 "Error handler scsi_eh_%d exiting\n",
2245 shost->host_no));
2246 shost->ehandler = NULL;
2247 return 0;
2248}
2249
2250/*
2251 * Function: scsi_report_bus_reset()
2252 *
2253 * Purpose: Utility function used by low-level drivers to report that
2254 * they have observed a bus reset on the bus being handled.
2255 *
2256 * Arguments: shost - Host in question
2257 * channel - channel on which reset was observed.
2258 *
2259 * Returns: Nothing
2260 *
2261 * Lock status: Host lock must be held.
2262 *
2263 * Notes: This only needs to be called if the reset is one which
2264 * originates from an unknown location. Resets originated
2265 * by the mid-level itself don't need to call this, but there
2266 * should be no harm.
2267 *
2268 * The main purpose of this is to make sure that a CHECK_CONDITION
2269 * is properly treated.
2270 */
2271void scsi_report_bus_reset(struct Scsi_Host *shost, int channel)
2272{
2273 struct scsi_device *sdev;
2274
2275 __shost_for_each_device(sdev, shost) {
2276 if (channel == sdev_channel(sdev))
2277 __scsi_report_device_reset(sdev, NULL);
2278 }
2279}
2280EXPORT_SYMBOL(scsi_report_bus_reset);
2281
2282/*
2283 * Function: scsi_report_device_reset()
2284 *
2285 * Purpose: Utility function used by low-level drivers to report that
2286 * they have observed a device reset on the device being handled.
2287 *
2288 * Arguments: shost - Host in question
2289 * channel - channel on which reset was observed
2290 * target - target on which reset was observed
2291 *
2292 * Returns: Nothing
2293 *
2294 * Lock status: Host lock must be held
2295 *
2296 * Notes: This only needs to be called if the reset is one which
2297 * originates from an unknown location. Resets originated
2298 * by the mid-level itself don't need to call this, but there
2299 * should be no harm.
2300 *
2301 * The main purpose of this is to make sure that a CHECK_CONDITION
2302 * is properly treated.
2303 */
2304void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
2305{
2306 struct scsi_device *sdev;
2307
2308 __shost_for_each_device(sdev, shost) {
2309 if (channel == sdev_channel(sdev) &&
2310 target == sdev_id(sdev))
2311 __scsi_report_device_reset(sdev, NULL);
2312 }
2313}
2314EXPORT_SYMBOL(scsi_report_device_reset);
2315
2316static void
2317scsi_reset_provider_done_command(struct scsi_cmnd *scmd)
2318{
2319}
2320
2321/**
2322 * scsi_ioctl_reset: explicitly reset a host/bus/target/device
2323 * @dev: scsi_device to operate on
2324 * @arg: reset type (see sg.h)
2325 */
2326int
2327scsi_ioctl_reset(struct scsi_device *dev, int __user *arg)
2328{
2329 struct scsi_cmnd *scmd;
2330 struct Scsi_Host *shost = dev->host;
2331 struct request req;
2332 unsigned long flags;
2333 int error = 0, rtn, val;
2334
2335 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2336 return -EACCES;
2337
2338 error = get_user(val, arg);
2339 if (error)
2340 return error;
2341
2342 if (scsi_autopm_get_host(shost) < 0)
2343 return -EIO;
2344
2345 error = -EIO;
2346 scmd = scsi_get_command(dev, GFP_KERNEL);
2347 if (!scmd)
2348 goto out_put_autopm_host;
2349
2350 blk_rq_init(NULL, &req);
2351 scmd->request = &req;
2352
2353 scmd->cmnd = req.cmd;
2354
2355 scmd->scsi_done = scsi_reset_provider_done_command;
2356 memset(&scmd->sdb, 0, sizeof(scmd->sdb));
2357
2358 scmd->cmd_len = 0;
2359
2360 scmd->sc_data_direction = DMA_BIDIRECTIONAL;
2361
2362 spin_lock_irqsave(shost->host_lock, flags);
2363 shost->tmf_in_progress = 1;
2364 spin_unlock_irqrestore(shost->host_lock, flags);
2365
2366 switch (val & ~SG_SCSI_RESET_NO_ESCALATE) {
2367 case SG_SCSI_RESET_NOTHING:
2368 rtn = SUCCESS;
2369 break;
2370 case SG_SCSI_RESET_DEVICE:
2371 rtn = scsi_try_bus_device_reset(scmd);
2372 if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE))
2373 break;
2374 /* FALLTHROUGH */
2375 case SG_SCSI_RESET_TARGET:
2376 rtn = scsi_try_target_reset(scmd);
2377 if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE))
2378 break;
2379 /* FALLTHROUGH */
2380 case SG_SCSI_RESET_BUS:
2381 rtn = scsi_try_bus_reset(scmd);
2382 if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE))
2383 break;
2384 /* FALLTHROUGH */
2385 case SG_SCSI_RESET_HOST:
2386 rtn = scsi_try_host_reset(scmd);
2387 if (rtn == SUCCESS)
2388 break;
2389 default:
2390 /* FALLTHROUGH */
2391 rtn = FAILED;
2392 break;
2393 }
2394
2395 error = (rtn == SUCCESS) ? 0 : -EIO;
2396
2397 spin_lock_irqsave(shost->host_lock, flags);
2398 shost->tmf_in_progress = 0;
2399 spin_unlock_irqrestore(shost->host_lock, flags);
2400
2401 /*
2402 * be sure to wake up anyone who was sleeping or had their queue
2403 * suspended while we performed the TMF.
2404 */
2405 SCSI_LOG_ERROR_RECOVERY(3,
2406 shost_printk(KERN_INFO, shost,
2407 "waking up host to restart after TMF\n"));
2408
2409 wake_up(&shost->host_wait);
2410 scsi_run_host_queues(shost);
2411
2412 scsi_put_command(scmd);
2413
2414out_put_autopm_host:
2415 scsi_autopm_put_host(shost);
2416 return error;
2417}
2418EXPORT_SYMBOL(scsi_ioctl_reset);
2419
2420bool scsi_command_normalize_sense(const struct scsi_cmnd *cmd,
2421 struct scsi_sense_hdr *sshdr)
2422{
2423 return scsi_normalize_sense(cmd->sense_buffer,
2424 SCSI_SENSE_BUFFERSIZE, sshdr);
2425}
2426EXPORT_SYMBOL(scsi_command_normalize_sense);
2427
2428/**
2429 * scsi_get_sense_info_fld - get information field from sense data (either fixed or descriptor format)
2430 * @sense_buffer: byte array of sense data
2431 * @sb_len: number of valid bytes in sense_buffer
2432 * @info_out: pointer to 64 integer where 8 or 4 byte information
2433 * field will be placed if found.
2434 *
2435 * Return value:
2436 * 1 if information field found, 0 if not found.
2437 */
2438int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len,
2439 u64 * info_out)
2440{
2441 int j;
2442 const u8 * ucp;
2443 u64 ull;
2444
2445 if (sb_len < 7)
2446 return 0;
2447 switch (sense_buffer[0] & 0x7f) {
2448 case 0x70:
2449 case 0x71:
2450 if (sense_buffer[0] & 0x80) {
2451 *info_out = (sense_buffer[3] << 24) +
2452 (sense_buffer[4] << 16) +
2453 (sense_buffer[5] << 8) + sense_buffer[6];
2454 return 1;
2455 } else
2456 return 0;
2457 case 0x72:
2458 case 0x73:
2459 ucp = scsi_sense_desc_find(sense_buffer, sb_len,
2460 0 /* info desc */);
2461 if (ucp && (0xa == ucp[1])) {
2462 ull = 0;
2463 for (j = 0; j < 8; ++j) {
2464 if (j > 0)
2465 ull <<= 8;
2466 ull |= ucp[4 + j];
2467 }
2468 *info_out = ull;
2469 return 1;
2470 } else
2471 return 0;
2472 default:
2473 return 0;
2474 }
2475}
2476EXPORT_SYMBOL(scsi_get_sense_info_fld);
1/*
2 * scsi_error.c Copyright (C) 1997 Eric Youngdale
3 *
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.
8 *
9 * Restructured scsi_unjam_host and associated functions.
10 * September 04, 2002 Mike Anderson (andmike@us.ibm.com)
11 *
12 * Forward port of Russell King's (rmk@arm.linux.org.uk) changes and
13 * minor cleanups.
14 * September 30, 2002 Mike Anderson (andmike@us.ibm.com)
15 */
16
17#include <linux/module.h>
18#include <linux/sched.h>
19#include <linux/gfp.h>
20#include <linux/timer.h>
21#include <linux/string.h>
22#include <linux/kernel.h>
23#include <linux/freezer.h>
24#include <linux/kthread.h>
25#include <linux/interrupt.h>
26#include <linux/blkdev.h>
27#include <linux/delay.h>
28
29#include <scsi/scsi.h>
30#include <scsi/scsi_cmnd.h>
31#include <scsi/scsi_dbg.h>
32#include <scsi/scsi_device.h>
33#include <scsi/scsi_driver.h>
34#include <scsi/scsi_eh.h>
35#include <scsi/scsi_transport.h>
36#include <scsi/scsi_host.h>
37#include <scsi/scsi_ioctl.h>
38
39#include "scsi_priv.h"
40#include "scsi_logging.h"
41#include "scsi_transport_api.h"
42
43#include <trace/events/scsi.h>
44
45static void scsi_eh_done(struct scsi_cmnd *scmd);
46
47#define SENSE_TIMEOUT (10*HZ)
48
49/*
50 * These should *probably* be handled by the host itself.
51 * Since it is allowed to sleep, it probably should.
52 */
53#define BUS_RESET_SETTLE_TIME (10)
54#define HOST_RESET_SETTLE_TIME (10)
55
56static int scsi_eh_try_stu(struct scsi_cmnd *scmd);
57
58/* called with shost->host_lock held */
59void scsi_eh_wakeup(struct Scsi_Host *shost)
60{
61 if (shost->host_busy == shost->host_failed) {
62 trace_scsi_eh_wakeup(shost);
63 wake_up_process(shost->ehandler);
64 SCSI_LOG_ERROR_RECOVERY(5,
65 printk("Waking error handler thread\n"));
66 }
67}
68
69/**
70 * scsi_schedule_eh - schedule EH for SCSI host
71 * @shost: SCSI host to invoke error handling on.
72 *
73 * Schedule SCSI EH without scmd.
74 */
75void scsi_schedule_eh(struct Scsi_Host *shost)
76{
77 unsigned long flags;
78
79 spin_lock_irqsave(shost->host_lock, flags);
80
81 if (scsi_host_set_state(shost, SHOST_RECOVERY) == 0 ||
82 scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY) == 0) {
83 shost->host_eh_scheduled++;
84 scsi_eh_wakeup(shost);
85 }
86
87 spin_unlock_irqrestore(shost->host_lock, flags);
88}
89EXPORT_SYMBOL_GPL(scsi_schedule_eh);
90
91/**
92 * scsi_eh_scmd_add - add scsi cmd to error handling.
93 * @scmd: scmd to run eh on.
94 * @eh_flag: optional SCSI_EH flag.
95 *
96 * Return value:
97 * 0 on failure.
98 */
99int scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag)
100{
101 struct Scsi_Host *shost = scmd->device->host;
102 unsigned long flags;
103 int ret = 0;
104
105 if (!shost->ehandler)
106 return 0;
107
108 spin_lock_irqsave(shost->host_lock, flags);
109 if (scsi_host_set_state(shost, SHOST_RECOVERY))
110 if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY))
111 goto out_unlock;
112
113 ret = 1;
114 scmd->eh_eflags |= eh_flag;
115 list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q);
116 shost->host_failed++;
117 scsi_eh_wakeup(shost);
118 out_unlock:
119 spin_unlock_irqrestore(shost->host_lock, flags);
120 return ret;
121}
122
123/**
124 * scsi_times_out - Timeout function for normal scsi commands.
125 * @req: request that is timing out.
126 *
127 * Notes:
128 * We do not need to lock this. There is the potential for a race
129 * only in that the normal completion handling might run, but if the
130 * normal completion function determines that the timer has already
131 * fired, then it mustn't do anything.
132 */
133enum blk_eh_timer_return scsi_times_out(struct request *req)
134{
135 struct scsi_cmnd *scmd = req->special;
136 enum blk_eh_timer_return rtn = BLK_EH_NOT_HANDLED;
137 struct Scsi_Host *host = scmd->device->host;
138
139 trace_scsi_dispatch_cmd_timeout(scmd);
140 scsi_log_completion(scmd, TIMEOUT_ERROR);
141
142 if (host->transportt->eh_timed_out)
143 rtn = host->transportt->eh_timed_out(scmd);
144 else if (host->hostt->eh_timed_out)
145 rtn = host->hostt->eh_timed_out(scmd);
146
147 scmd->result |= DID_TIME_OUT << 16;
148
149 if (unlikely(rtn == BLK_EH_NOT_HANDLED &&
150 !scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD)))
151 rtn = BLK_EH_HANDLED;
152
153 return rtn;
154}
155
156/**
157 * scsi_block_when_processing_errors - Prevent cmds from being queued.
158 * @sdev: Device on which we are performing recovery.
159 *
160 * Description:
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.
163 *
164 * Return value:
165 * 0 when dev was taken offline by error recovery. 1 OK to proceed.
166 */
167int scsi_block_when_processing_errors(struct scsi_device *sdev)
168{
169 int online;
170
171 wait_event(sdev->host->host_wait, !scsi_host_in_recovery(sdev->host));
172
173 online = scsi_device_online(sdev);
174
175 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: rtn: %d\n", __func__,
176 online));
177
178 return online;
179}
180EXPORT_SYMBOL(scsi_block_when_processing_errors);
181
182#ifdef CONFIG_SCSI_LOGGING
183/**
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.
187 */
188static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost,
189 struct list_head *work_q)
190{
191 struct scsi_cmnd *scmd;
192 struct scsi_device *sdev;
193 int total_failures = 0;
194 int cmd_failed = 0;
195 int cmd_cancel = 0;
196 int devices_failed = 0;
197
198 shost_for_each_device(sdev, shost) {
199 list_for_each_entry(scmd, work_q, eh_entry) {
200 if (scmd->device == sdev) {
201 ++total_failures;
202 if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD)
203 ++cmd_cancel;
204 else
205 ++cmd_failed;
206 }
207 }
208
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,
214 cmd_cancel));
215 cmd_cancel = 0;
216 cmd_failed = 0;
217 ++devices_failed;
218 }
219 }
220
221 SCSI_LOG_ERROR_RECOVERY(2, printk("Total of %d commands on %d"
222 " devices require eh work\n",
223 total_failures, devices_failed));
224}
225#endif
226
227/**
228 * scsi_check_sense - Examine scsi cmd sense
229 * @scmd: Cmd to have sense checked.
230 *
231 * Return value:
232 * SUCCESS or FAILED or NEEDS_RETRY or TARGET_ERROR
233 *
234 * Notes:
235 * When a deferred error is detected the current command has
236 * not been executed and needs retrying.
237 */
238static int scsi_check_sense(struct scsi_cmnd *scmd)
239{
240 struct scsi_device *sdev = scmd->device;
241 struct scsi_sense_hdr sshdr;
242
243 if (! scsi_command_normalize_sense(scmd, &sshdr))
244 return FAILED; /* no valid sense data */
245
246 if (scmd->cmnd[0] == TEST_UNIT_READY && scmd->scsi_done != scsi_eh_done)
247 /*
248 * nasty: for mid-layer issued TURs, we need to return the
249 * actual sense data without any recovery attempt. For eh
250 * issued ones, we need to try to recover and interpret
251 */
252 return SUCCESS;
253
254 if (scsi_sense_is_deferred(&sshdr))
255 return NEEDS_RETRY;
256
257 if (sdev->scsi_dh_data && sdev->scsi_dh_data->scsi_dh &&
258 sdev->scsi_dh_data->scsi_dh->check_sense) {
259 int rc;
260
261 rc = sdev->scsi_dh_data->scsi_dh->check_sense(sdev, &sshdr);
262 if (rc != SCSI_RETURN_NOT_HANDLED)
263 return rc;
264 /* handler does not care. Drop down to default handling */
265 }
266
267 /*
268 * Previous logic looked for FILEMARK, EOM or ILI which are
269 * mainly associated with tapes and returned SUCCESS.
270 */
271 if (sshdr.response_code == 0x70) {
272 /* fixed format */
273 if (scmd->sense_buffer[2] & 0xe0)
274 return SUCCESS;
275 } else {
276 /*
277 * descriptor format: look for "stream commands sense data
278 * descriptor" (see SSC-3). Assume single sense data
279 * descriptor. Ignore ILI from SBC-2 READ LONG and WRITE LONG.
280 */
281 if ((sshdr.additional_length > 3) &&
282 (scmd->sense_buffer[8] == 0x4) &&
283 (scmd->sense_buffer[11] & 0xe0))
284 return SUCCESS;
285 }
286
287 switch (sshdr.sense_key) {
288 case NO_SENSE:
289 return SUCCESS;
290 case RECOVERED_ERROR:
291 return /* soft_error */ SUCCESS;
292
293 case ABORTED_COMMAND:
294 if (sshdr.asc == 0x10) /* DIF */
295 return SUCCESS;
296
297 return NEEDS_RETRY;
298 case NOT_READY:
299 case UNIT_ATTENTION:
300 /*
301 * if we are expecting a cc/ua because of a bus reset that we
302 * performed, treat this just as a retry. otherwise this is
303 * information that we should pass up to the upper-level driver
304 * so that we can deal with it there.
305 */
306 if (scmd->device->expecting_cc_ua) {
307 /*
308 * Because some device does not queue unit
309 * attentions correctly, we carefully check
310 * additional sense code and qualifier so as
311 * not to squash media change unit attention.
312 */
313 if (sshdr.asc != 0x28 || sshdr.ascq != 0x00) {
314 scmd->device->expecting_cc_ua = 0;
315 return NEEDS_RETRY;
316 }
317 }
318 /*
319 * if the device is in the process of becoming ready, we
320 * should retry.
321 */
322 if ((sshdr.asc == 0x04) && (sshdr.ascq == 0x01))
323 return NEEDS_RETRY;
324 /*
325 * if the device is not started, we need to wake
326 * the error handler to start the motor
327 */
328 if (scmd->device->allow_restart &&
329 (sshdr.asc == 0x04) && (sshdr.ascq == 0x02))
330 return FAILED;
331
332 if (sshdr.asc == 0x3f && sshdr.ascq == 0x0e)
333 scmd_printk(KERN_WARNING, scmd,
334 "Warning! Received an indication that the "
335 "LUN assignments on this target have "
336 "changed. The Linux SCSI layer does not "
337 "automatically remap LUN assignments.\n");
338 else if (sshdr.asc == 0x3f)
339 scmd_printk(KERN_WARNING, scmd,
340 "Warning! Received an indication that the "
341 "operating parameters on this target have "
342 "changed. The Linux SCSI layer does not "
343 "automatically adjust these parameters.\n");
344
345 if (sshdr.asc == 0x38 && sshdr.ascq == 0x07)
346 scmd_printk(KERN_WARNING, scmd,
347 "Warning! Received an indication that the "
348 "LUN reached a thin provisioning soft "
349 "threshold.\n");
350
351 /*
352 * Pass the UA upwards for a determination in the completion
353 * functions.
354 */
355 return SUCCESS;
356
357 /* these are not supported */
358 case COPY_ABORTED:
359 case VOLUME_OVERFLOW:
360 case MISCOMPARE:
361 case BLANK_CHECK:
362 case DATA_PROTECT:
363 return TARGET_ERROR;
364
365 case MEDIUM_ERROR:
366 if (sshdr.asc == 0x11 || /* UNRECOVERED READ ERR */
367 sshdr.asc == 0x13 || /* AMNF DATA FIELD */
368 sshdr.asc == 0x14) { /* RECORD NOT FOUND */
369 return TARGET_ERROR;
370 }
371 return NEEDS_RETRY;
372
373 case HARDWARE_ERROR:
374 if (scmd->device->retry_hwerror)
375 return ADD_TO_MLQUEUE;
376 else
377 return TARGET_ERROR;
378
379 case ILLEGAL_REQUEST:
380 if (sshdr.asc == 0x20 || /* Invalid command operation code */
381 sshdr.asc == 0x21 || /* Logical block address out of range */
382 sshdr.asc == 0x24 || /* Invalid field in cdb */
383 sshdr.asc == 0x26) { /* Parameter value invalid */
384 return TARGET_ERROR;
385 }
386 return SUCCESS;
387
388 default:
389 return SUCCESS;
390 }
391}
392
393static void scsi_handle_queue_ramp_up(struct scsi_device *sdev)
394{
395 struct scsi_host_template *sht = sdev->host->hostt;
396 struct scsi_device *tmp_sdev;
397
398 if (!sht->change_queue_depth ||
399 sdev->queue_depth >= sdev->max_queue_depth)
400 return;
401
402 if (time_before(jiffies,
403 sdev->last_queue_ramp_up + sdev->queue_ramp_up_period))
404 return;
405
406 if (time_before(jiffies,
407 sdev->last_queue_full_time + sdev->queue_ramp_up_period))
408 return;
409
410 /*
411 * Walk all devices of a target and do
412 * ramp up on them.
413 */
414 shost_for_each_device(tmp_sdev, sdev->host) {
415 if (tmp_sdev->channel != sdev->channel ||
416 tmp_sdev->id != sdev->id ||
417 tmp_sdev->queue_depth == sdev->max_queue_depth)
418 continue;
419 /*
420 * call back into LLD to increase queue_depth by one
421 * with ramp up reason code.
422 */
423 sht->change_queue_depth(tmp_sdev, tmp_sdev->queue_depth + 1,
424 SCSI_QDEPTH_RAMP_UP);
425 sdev->last_queue_ramp_up = jiffies;
426 }
427}
428
429static void scsi_handle_queue_full(struct scsi_device *sdev)
430{
431 struct scsi_host_template *sht = sdev->host->hostt;
432 struct scsi_device *tmp_sdev;
433
434 if (!sht->change_queue_depth)
435 return;
436
437 shost_for_each_device(tmp_sdev, sdev->host) {
438 if (tmp_sdev->channel != sdev->channel ||
439 tmp_sdev->id != sdev->id)
440 continue;
441 /*
442 * We do not know the number of commands that were at
443 * the device when we got the queue full so we start
444 * from the highest possible value and work our way down.
445 */
446 sht->change_queue_depth(tmp_sdev, tmp_sdev->queue_depth - 1,
447 SCSI_QDEPTH_QFULL);
448 }
449}
450
451/**
452 * scsi_eh_completed_normally - Disposition a eh cmd on return from LLD.
453 * @scmd: SCSI cmd to examine.
454 *
455 * Notes:
456 * This is *only* called when we are examining the status of commands
457 * queued during error recovery. the main difference here is that we
458 * don't allow for the possibility of retries here, and we are a lot
459 * more restrictive about what we consider acceptable.
460 */
461static int scsi_eh_completed_normally(struct scsi_cmnd *scmd)
462{
463 /*
464 * first check the host byte, to see if there is anything in there
465 * that would indicate what we need to do.
466 */
467 if (host_byte(scmd->result) == DID_RESET) {
468 /*
469 * rats. we are already in the error handler, so we now
470 * get to try and figure out what to do next. if the sense
471 * is valid, we have a pretty good idea of what to do.
472 * if not, we mark it as FAILED.
473 */
474 return scsi_check_sense(scmd);
475 }
476 if (host_byte(scmd->result) != DID_OK)
477 return FAILED;
478
479 /*
480 * next, check the message byte.
481 */
482 if (msg_byte(scmd->result) != COMMAND_COMPLETE)
483 return FAILED;
484
485 /*
486 * now, check the status byte to see if this indicates
487 * anything special.
488 */
489 switch (status_byte(scmd->result)) {
490 case GOOD:
491 scsi_handle_queue_ramp_up(scmd->device);
492 case COMMAND_TERMINATED:
493 return SUCCESS;
494 case CHECK_CONDITION:
495 return scsi_check_sense(scmd);
496 case CONDITION_GOOD:
497 case INTERMEDIATE_GOOD:
498 case INTERMEDIATE_C_GOOD:
499 /*
500 * who knows? FIXME(eric)
501 */
502 return SUCCESS;
503 case RESERVATION_CONFLICT:
504 if (scmd->cmnd[0] == TEST_UNIT_READY)
505 /* it is a success, we probed the device and
506 * found it */
507 return SUCCESS;
508 /* otherwise, we failed to send the command */
509 return FAILED;
510 case QUEUE_FULL:
511 scsi_handle_queue_full(scmd->device);
512 /* fall through */
513 case BUSY:
514 return NEEDS_RETRY;
515 default:
516 return FAILED;
517 }
518 return FAILED;
519}
520
521/**
522 * scsi_eh_done - Completion function for error handling.
523 * @scmd: Cmd that is done.
524 */
525static void scsi_eh_done(struct scsi_cmnd *scmd)
526{
527 struct completion *eh_action;
528
529 SCSI_LOG_ERROR_RECOVERY(3,
530 printk("%s scmd: %p result: %x\n",
531 __func__, scmd, scmd->result));
532
533 eh_action = scmd->device->host->eh_action;
534 if (eh_action)
535 complete(eh_action);
536}
537
538/**
539 * scsi_try_host_reset - ask host adapter to reset itself
540 * @scmd: SCSI cmd to send hsot reset.
541 */
542static int scsi_try_host_reset(struct scsi_cmnd *scmd)
543{
544 unsigned long flags;
545 int rtn;
546 struct Scsi_Host *host = scmd->device->host;
547 struct scsi_host_template *hostt = host->hostt;
548
549 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Host RST\n",
550 __func__));
551
552 if (!hostt->eh_host_reset_handler)
553 return FAILED;
554
555 rtn = hostt->eh_host_reset_handler(scmd);
556
557 if (rtn == SUCCESS) {
558 if (!hostt->skip_settle_delay)
559 ssleep(HOST_RESET_SETTLE_TIME);
560 spin_lock_irqsave(host->host_lock, flags);
561 scsi_report_bus_reset(host, scmd_channel(scmd));
562 spin_unlock_irqrestore(host->host_lock, flags);
563 }
564
565 return rtn;
566}
567
568/**
569 * scsi_try_bus_reset - ask host to perform a bus reset
570 * @scmd: SCSI cmd to send bus reset.
571 */
572static int scsi_try_bus_reset(struct scsi_cmnd *scmd)
573{
574 unsigned long flags;
575 int rtn;
576 struct Scsi_Host *host = scmd->device->host;
577 struct scsi_host_template *hostt = host->hostt;
578
579 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Bus RST\n",
580 __func__));
581
582 if (!hostt->eh_bus_reset_handler)
583 return FAILED;
584
585 rtn = hostt->eh_bus_reset_handler(scmd);
586
587 if (rtn == SUCCESS) {
588 if (!hostt->skip_settle_delay)
589 ssleep(BUS_RESET_SETTLE_TIME);
590 spin_lock_irqsave(host->host_lock, flags);
591 scsi_report_bus_reset(host, scmd_channel(scmd));
592 spin_unlock_irqrestore(host->host_lock, flags);
593 }
594
595 return rtn;
596}
597
598static void __scsi_report_device_reset(struct scsi_device *sdev, void *data)
599{
600 sdev->was_reset = 1;
601 sdev->expecting_cc_ua = 1;
602}
603
604/**
605 * scsi_try_target_reset - Ask host to perform a target reset
606 * @scmd: SCSI cmd used to send a target reset
607 *
608 * Notes:
609 * There is no timeout for this operation. if this operation is
610 * unreliable for a given host, then the host itself needs to put a
611 * timer on it, and set the host back to a consistent state prior to
612 * returning.
613 */
614static int scsi_try_target_reset(struct scsi_cmnd *scmd)
615{
616 unsigned long flags;
617 int rtn;
618 struct Scsi_Host *host = scmd->device->host;
619 struct scsi_host_template *hostt = host->hostt;
620
621 if (!hostt->eh_target_reset_handler)
622 return FAILED;
623
624 rtn = hostt->eh_target_reset_handler(scmd);
625 if (rtn == SUCCESS) {
626 spin_lock_irqsave(host->host_lock, flags);
627 __starget_for_each_device(scsi_target(scmd->device), NULL,
628 __scsi_report_device_reset);
629 spin_unlock_irqrestore(host->host_lock, flags);
630 }
631
632 return rtn;
633}
634
635/**
636 * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev
637 * @scmd: SCSI cmd used to send BDR
638 *
639 * Notes:
640 * There is no timeout for this operation. if this operation is
641 * unreliable for a given host, then the host itself needs to put a
642 * timer on it, and set the host back to a consistent state prior to
643 * returning.
644 */
645static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd)
646{
647 int rtn;
648 struct scsi_host_template *hostt = scmd->device->host->hostt;
649
650 if (!hostt->eh_device_reset_handler)
651 return FAILED;
652
653 rtn = hostt->eh_device_reset_handler(scmd);
654 if (rtn == SUCCESS)
655 __scsi_report_device_reset(scmd->device, NULL);
656 return rtn;
657}
658
659static int scsi_try_to_abort_cmd(struct scsi_host_template *hostt, struct scsi_cmnd *scmd)
660{
661 if (!hostt->eh_abort_handler)
662 return FAILED;
663
664 return hostt->eh_abort_handler(scmd);
665}
666
667static void scsi_abort_eh_cmnd(struct scsi_cmnd *scmd)
668{
669 if (scsi_try_to_abort_cmd(scmd->device->host->hostt, scmd) != SUCCESS)
670 if (scsi_try_bus_device_reset(scmd) != SUCCESS)
671 if (scsi_try_target_reset(scmd) != SUCCESS)
672 if (scsi_try_bus_reset(scmd) != SUCCESS)
673 scsi_try_host_reset(scmd);
674}
675
676/**
677 * scsi_eh_prep_cmnd - Save a scsi command info as part of error recovery
678 * @scmd: SCSI command structure to hijack
679 * @ses: structure to save restore information
680 * @cmnd: CDB to send. Can be NULL if no new cmnd is needed
681 * @cmnd_size: size in bytes of @cmnd (must be <= BLK_MAX_CDB)
682 * @sense_bytes: size of sense data to copy. or 0 (if != 0 @cmnd is ignored)
683 *
684 * This function is used to save a scsi command information before re-execution
685 * as part of the error recovery process. If @sense_bytes is 0 the command
686 * sent must be one that does not transfer any data. If @sense_bytes != 0
687 * @cmnd is ignored and this functions sets up a REQUEST_SENSE command
688 * and cmnd buffers to read @sense_bytes into @scmd->sense_buffer.
689 */
690void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd, struct scsi_eh_save *ses,
691 unsigned char *cmnd, int cmnd_size, unsigned sense_bytes)
692{
693 struct scsi_device *sdev = scmd->device;
694
695 /*
696 * We need saved copies of a number of fields - this is because
697 * error handling may need to overwrite these with different values
698 * to run different commands, and once error handling is complete,
699 * we will need to restore these values prior to running the actual
700 * command.
701 */
702 ses->cmd_len = scmd->cmd_len;
703 ses->cmnd = scmd->cmnd;
704 ses->data_direction = scmd->sc_data_direction;
705 ses->sdb = scmd->sdb;
706 ses->next_rq = scmd->request->next_rq;
707 ses->result = scmd->result;
708 ses->underflow = scmd->underflow;
709 ses->prot_op = scmd->prot_op;
710
711 scmd->prot_op = SCSI_PROT_NORMAL;
712 scmd->cmnd = ses->eh_cmnd;
713 memset(scmd->cmnd, 0, BLK_MAX_CDB);
714 memset(&scmd->sdb, 0, sizeof(scmd->sdb));
715 scmd->request->next_rq = NULL;
716
717 if (sense_bytes) {
718 scmd->sdb.length = min_t(unsigned, SCSI_SENSE_BUFFERSIZE,
719 sense_bytes);
720 sg_init_one(&ses->sense_sgl, scmd->sense_buffer,
721 scmd->sdb.length);
722 scmd->sdb.table.sgl = &ses->sense_sgl;
723 scmd->sc_data_direction = DMA_FROM_DEVICE;
724 scmd->sdb.table.nents = 1;
725 scmd->cmnd[0] = REQUEST_SENSE;
726 scmd->cmnd[4] = scmd->sdb.length;
727 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
728 } else {
729 scmd->sc_data_direction = DMA_NONE;
730 if (cmnd) {
731 BUG_ON(cmnd_size > BLK_MAX_CDB);
732 memcpy(scmd->cmnd, cmnd, cmnd_size);
733 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
734 }
735 }
736
737 scmd->underflow = 0;
738
739 if (sdev->scsi_level <= SCSI_2 && sdev->scsi_level != SCSI_UNKNOWN)
740 scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) |
741 (sdev->lun << 5 & 0xe0);
742
743 /*
744 * Zero the sense buffer. The scsi spec mandates that any
745 * untransferred sense data should be interpreted as being zero.
746 */
747 memset(scmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
748}
749EXPORT_SYMBOL(scsi_eh_prep_cmnd);
750
751/**
752 * scsi_eh_restore_cmnd - Restore a scsi command info as part of error recovery
753 * @scmd: SCSI command structure to restore
754 * @ses: saved information from a coresponding call to scsi_eh_prep_cmnd
755 *
756 * Undo any damage done by above scsi_eh_prep_cmnd().
757 */
758void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd, struct scsi_eh_save *ses)
759{
760 /*
761 * Restore original data
762 */
763 scmd->cmd_len = ses->cmd_len;
764 scmd->cmnd = ses->cmnd;
765 scmd->sc_data_direction = ses->data_direction;
766 scmd->sdb = ses->sdb;
767 scmd->request->next_rq = ses->next_rq;
768 scmd->result = ses->result;
769 scmd->underflow = ses->underflow;
770 scmd->prot_op = ses->prot_op;
771}
772EXPORT_SYMBOL(scsi_eh_restore_cmnd);
773
774/**
775 * scsi_send_eh_cmnd - submit a scsi command as part of error recovery
776 * @scmd: SCSI command structure to hijack
777 * @cmnd: CDB to send
778 * @cmnd_size: size in bytes of @cmnd
779 * @timeout: timeout for this request
780 * @sense_bytes: size of sense data to copy or 0
781 *
782 * This function is used to send a scsi command down to a target device
783 * as part of the error recovery process. See also scsi_eh_prep_cmnd() above.
784 *
785 * Return value:
786 * SUCCESS or FAILED or NEEDS_RETRY
787 */
788static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
789 int cmnd_size, int timeout, unsigned sense_bytes)
790{
791 struct scsi_device *sdev = scmd->device;
792 struct scsi_driver *sdrv = scsi_cmd_to_driver(scmd);
793 struct Scsi_Host *shost = sdev->host;
794 DECLARE_COMPLETION_ONSTACK(done);
795 unsigned long timeleft;
796 struct scsi_eh_save ses;
797 int rtn;
798
799 scsi_eh_prep_cmnd(scmd, &ses, cmnd, cmnd_size, sense_bytes);
800 shost->eh_action = &done;
801
802 scsi_log_send(scmd);
803 scmd->scsi_done = scsi_eh_done;
804 shost->hostt->queuecommand(shost, scmd);
805
806 timeleft = wait_for_completion_timeout(&done, timeout);
807
808 shost->eh_action = NULL;
809
810 scsi_log_completion(scmd, SUCCESS);
811
812 SCSI_LOG_ERROR_RECOVERY(3,
813 printk("%s: scmd: %p, timeleft: %ld\n",
814 __func__, scmd, timeleft));
815
816 /*
817 * If there is time left scsi_eh_done got called, and we will
818 * examine the actual status codes to see whether the command
819 * actually did complete normally, else tell the host to forget
820 * about this command.
821 */
822 if (timeleft) {
823 rtn = scsi_eh_completed_normally(scmd);
824 SCSI_LOG_ERROR_RECOVERY(3,
825 printk("%s: scsi_eh_completed_normally %x\n",
826 __func__, rtn));
827
828 switch (rtn) {
829 case SUCCESS:
830 case NEEDS_RETRY:
831 case FAILED:
832 case TARGET_ERROR:
833 break;
834 case ADD_TO_MLQUEUE:
835 rtn = NEEDS_RETRY;
836 break;
837 default:
838 rtn = FAILED;
839 break;
840 }
841 } else {
842 scsi_abort_eh_cmnd(scmd);
843 rtn = FAILED;
844 }
845
846 scsi_eh_restore_cmnd(scmd, &ses);
847
848 if (sdrv && sdrv->eh_action)
849 rtn = sdrv->eh_action(scmd, cmnd, cmnd_size, rtn);
850
851 return rtn;
852}
853
854/**
855 * scsi_request_sense - Request sense data from a particular target.
856 * @scmd: SCSI cmd for request sense.
857 *
858 * Notes:
859 * Some hosts automatically obtain this information, others require
860 * that we obtain it on our own. This function will *not* return until
861 * the command either times out, or it completes.
862 */
863static int scsi_request_sense(struct scsi_cmnd *scmd)
864{
865 return scsi_send_eh_cmnd(scmd, NULL, 0, SENSE_TIMEOUT, ~0);
866}
867
868/**
869 * scsi_eh_finish_cmd - Handle a cmd that eh is finished with.
870 * @scmd: Original SCSI cmd that eh has finished.
871 * @done_q: Queue for processed commands.
872 *
873 * Notes:
874 * We don't want to use the normal command completion while we are are
875 * still handling errors - it may cause other commands to be queued,
876 * and that would disturb what we are doing. Thus we really want to
877 * keep a list of pending commands for final completion, and once we
878 * are ready to leave error handling we handle completion for real.
879 */
880void scsi_eh_finish_cmd(struct scsi_cmnd *scmd, struct list_head *done_q)
881{
882 scmd->device->host->host_failed--;
883 scmd->eh_eflags = 0;
884 list_move_tail(&scmd->eh_entry, done_q);
885}
886EXPORT_SYMBOL(scsi_eh_finish_cmd);
887
888/**
889 * scsi_eh_get_sense - Get device sense data.
890 * @work_q: Queue of commands to process.
891 * @done_q: Queue of processed commands.
892 *
893 * Description:
894 * See if we need to request sense information. if so, then get it
895 * now, so we have a better idea of what to do.
896 *
897 * Notes:
898 * This has the unfortunate side effect that if a shost adapter does
899 * not automatically request sense information, we end up shutting
900 * it down before we request it.
901 *
902 * All drivers should request sense information internally these days,
903 * so for now all I have to say is tough noogies if you end up in here.
904 *
905 * XXX: Long term this code should go away, but that needs an audit of
906 * all LLDDs first.
907 */
908int scsi_eh_get_sense(struct list_head *work_q,
909 struct list_head *done_q)
910{
911 struct scsi_cmnd *scmd, *next;
912 int rtn;
913
914 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
915 if ((scmd->eh_eflags & SCSI_EH_CANCEL_CMD) ||
916 SCSI_SENSE_VALID(scmd))
917 continue;
918
919 SCSI_LOG_ERROR_RECOVERY(2, scmd_printk(KERN_INFO, scmd,
920 "%s: requesting sense\n",
921 current->comm));
922 rtn = scsi_request_sense(scmd);
923 if (rtn != SUCCESS)
924 continue;
925
926 SCSI_LOG_ERROR_RECOVERY(3, printk("sense requested for %p"
927 " result %x\n", scmd,
928 scmd->result));
929 SCSI_LOG_ERROR_RECOVERY(3, scsi_print_sense("bh", scmd));
930
931 rtn = scsi_decide_disposition(scmd);
932
933 /*
934 * if the result was normal, then just pass it along to the
935 * upper level.
936 */
937 if (rtn == SUCCESS)
938 /* we don't want this command reissued, just
939 * finished with the sense data, so set
940 * retries to the max allowed to ensure it
941 * won't get reissued */
942 scmd->retries = scmd->allowed;
943 else if (rtn != NEEDS_RETRY)
944 continue;
945
946 scsi_eh_finish_cmd(scmd, done_q);
947 }
948
949 return list_empty(work_q);
950}
951EXPORT_SYMBOL_GPL(scsi_eh_get_sense);
952
953/**
954 * scsi_eh_tur - Send TUR to device.
955 * @scmd: &scsi_cmnd to send TUR
956 *
957 * Return value:
958 * 0 - Device is ready. 1 - Device NOT ready.
959 */
960static int scsi_eh_tur(struct scsi_cmnd *scmd)
961{
962 static unsigned char tur_command[6] = {TEST_UNIT_READY, 0, 0, 0, 0, 0};
963 int retry_cnt = 1, rtn;
964
965retry_tur:
966 rtn = scsi_send_eh_cmnd(scmd, tur_command, 6, SENSE_TIMEOUT, 0);
967
968 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n",
969 __func__, scmd, rtn));
970
971 switch (rtn) {
972 case NEEDS_RETRY:
973 if (retry_cnt--)
974 goto retry_tur;
975 /*FALLTHRU*/
976 case SUCCESS:
977 return 0;
978 default:
979 return 1;
980 }
981}
982
983/**
984 * scsi_eh_test_devices - check if devices are responding from error recovery.
985 * @cmd_list: scsi commands in error recovery.
986 * @work_q: queue for commands which still need more error recovery
987 * @done_q: queue for commands which are finished
988 * @try_stu: boolean on if a STU command should be tried in addition to TUR.
989 *
990 * Decription:
991 * Tests if devices are in a working state. Commands to devices now in
992 * a working state are sent to the done_q while commands to devices which
993 * are still failing to respond are returned to the work_q for more
994 * processing.
995 **/
996static int scsi_eh_test_devices(struct list_head *cmd_list,
997 struct list_head *work_q,
998 struct list_head *done_q, int try_stu)
999{
1000 struct scsi_cmnd *scmd, *next;
1001 struct scsi_device *sdev;
1002 int finish_cmds;
1003
1004 while (!list_empty(cmd_list)) {
1005 scmd = list_entry(cmd_list->next, struct scsi_cmnd, eh_entry);
1006 sdev = scmd->device;
1007
1008 finish_cmds = !scsi_device_online(scmd->device) ||
1009 (try_stu && !scsi_eh_try_stu(scmd) &&
1010 !scsi_eh_tur(scmd)) ||
1011 !scsi_eh_tur(scmd);
1012
1013 list_for_each_entry_safe(scmd, next, cmd_list, eh_entry)
1014 if (scmd->device == sdev) {
1015 if (finish_cmds)
1016 scsi_eh_finish_cmd(scmd, done_q);
1017 else
1018 list_move_tail(&scmd->eh_entry, work_q);
1019 }
1020 }
1021 return list_empty(work_q);
1022}
1023
1024
1025/**
1026 * scsi_eh_abort_cmds - abort pending commands.
1027 * @work_q: &list_head for pending commands.
1028 * @done_q: &list_head for processed commands.
1029 *
1030 * Decription:
1031 * Try and see whether or not it makes sense to try and abort the
1032 * running command. This only works out to be the case if we have one
1033 * command that has timed out. If the command simply failed, it makes
1034 * no sense to try and abort the command, since as far as the shost
1035 * adapter is concerned, it isn't running.
1036 */
1037static int scsi_eh_abort_cmds(struct list_head *work_q,
1038 struct list_head *done_q)
1039{
1040 struct scsi_cmnd *scmd, *next;
1041 LIST_HEAD(check_list);
1042 int rtn;
1043
1044 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1045 if (!(scmd->eh_eflags & SCSI_EH_CANCEL_CMD))
1046 continue;
1047 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting cmd:"
1048 "0x%p\n", current->comm,
1049 scmd));
1050 rtn = scsi_try_to_abort_cmd(scmd->device->host->hostt, scmd);
1051 if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
1052 scmd->eh_eflags &= ~SCSI_EH_CANCEL_CMD;
1053 if (rtn == FAST_IO_FAIL)
1054 scsi_eh_finish_cmd(scmd, done_q);
1055 else
1056 list_move_tail(&scmd->eh_entry, &check_list);
1057 } else
1058 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting"
1059 " cmd failed:"
1060 "0x%p\n",
1061 current->comm,
1062 scmd));
1063 }
1064
1065 return scsi_eh_test_devices(&check_list, work_q, done_q, 0);
1066}
1067
1068/**
1069 * scsi_eh_try_stu - Send START_UNIT to device.
1070 * @scmd: &scsi_cmnd to send START_UNIT
1071 *
1072 * Return value:
1073 * 0 - Device is ready. 1 - Device NOT ready.
1074 */
1075static int scsi_eh_try_stu(struct scsi_cmnd *scmd)
1076{
1077 static unsigned char stu_command[6] = {START_STOP, 0, 0, 0, 1, 0};
1078
1079 if (scmd->device->allow_restart) {
1080 int i, rtn = NEEDS_RETRY;
1081
1082 for (i = 0; rtn == NEEDS_RETRY && i < 2; i++)
1083 rtn = scsi_send_eh_cmnd(scmd, stu_command, 6, scmd->device->request_queue->rq_timeout, 0);
1084
1085 if (rtn == SUCCESS)
1086 return 0;
1087 }
1088
1089 return 1;
1090}
1091
1092 /**
1093 * scsi_eh_stu - send START_UNIT if needed
1094 * @shost: &scsi host being recovered.
1095 * @work_q: &list_head for pending commands.
1096 * @done_q: &list_head for processed commands.
1097 *
1098 * Notes:
1099 * If commands are failing due to not ready, initializing command required,
1100 * try revalidating the device, which will end up sending a start unit.
1101 */
1102static int scsi_eh_stu(struct Scsi_Host *shost,
1103 struct list_head *work_q,
1104 struct list_head *done_q)
1105{
1106 struct scsi_cmnd *scmd, *stu_scmd, *next;
1107 struct scsi_device *sdev;
1108
1109 shost_for_each_device(sdev, shost) {
1110 stu_scmd = NULL;
1111 list_for_each_entry(scmd, work_q, eh_entry)
1112 if (scmd->device == sdev && SCSI_SENSE_VALID(scmd) &&
1113 scsi_check_sense(scmd) == FAILED ) {
1114 stu_scmd = scmd;
1115 break;
1116 }
1117
1118 if (!stu_scmd)
1119 continue;
1120
1121 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending START_UNIT to sdev:"
1122 " 0x%p\n", current->comm, sdev));
1123
1124 if (!scsi_eh_try_stu(stu_scmd)) {
1125 if (!scsi_device_online(sdev) ||
1126 !scsi_eh_tur(stu_scmd)) {
1127 list_for_each_entry_safe(scmd, next,
1128 work_q, eh_entry) {
1129 if (scmd->device == sdev)
1130 scsi_eh_finish_cmd(scmd, done_q);
1131 }
1132 }
1133 } else {
1134 SCSI_LOG_ERROR_RECOVERY(3,
1135 printk("%s: START_UNIT failed to sdev:"
1136 " 0x%p\n", current->comm, sdev));
1137 }
1138 }
1139
1140 return list_empty(work_q);
1141}
1142
1143
1144/**
1145 * scsi_eh_bus_device_reset - send bdr if needed
1146 * @shost: scsi host being recovered.
1147 * @work_q: &list_head for pending commands.
1148 * @done_q: &list_head for processed commands.
1149 *
1150 * Notes:
1151 * Try a bus device reset. Still, look to see whether we have multiple
1152 * devices that are jammed or not - if we have multiple devices, it
1153 * makes no sense to try bus_device_reset - we really would need to try
1154 * a bus_reset instead.
1155 */
1156static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
1157 struct list_head *work_q,
1158 struct list_head *done_q)
1159{
1160 struct scsi_cmnd *scmd, *bdr_scmd, *next;
1161 struct scsi_device *sdev;
1162 int rtn;
1163
1164 shost_for_each_device(sdev, shost) {
1165 bdr_scmd = NULL;
1166 list_for_each_entry(scmd, work_q, eh_entry)
1167 if (scmd->device == sdev) {
1168 bdr_scmd = scmd;
1169 break;
1170 }
1171
1172 if (!bdr_scmd)
1173 continue;
1174
1175 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BDR sdev:"
1176 " 0x%p\n", current->comm,
1177 sdev));
1178 rtn = scsi_try_bus_device_reset(bdr_scmd);
1179 if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
1180 if (!scsi_device_online(sdev) ||
1181 rtn == FAST_IO_FAIL ||
1182 !scsi_eh_tur(bdr_scmd)) {
1183 list_for_each_entry_safe(scmd, next,
1184 work_q, eh_entry) {
1185 if (scmd->device == sdev)
1186 scsi_eh_finish_cmd(scmd,
1187 done_q);
1188 }
1189 }
1190 } else {
1191 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BDR"
1192 " failed sdev:"
1193 "0x%p\n",
1194 current->comm,
1195 sdev));
1196 }
1197 }
1198
1199 return list_empty(work_q);
1200}
1201
1202/**
1203 * scsi_eh_target_reset - send target reset if needed
1204 * @shost: scsi host being recovered.
1205 * @work_q: &list_head for pending commands.
1206 * @done_q: &list_head for processed commands.
1207 *
1208 * Notes:
1209 * Try a target reset.
1210 */
1211static int scsi_eh_target_reset(struct Scsi_Host *shost,
1212 struct list_head *work_q,
1213 struct list_head *done_q)
1214{
1215 LIST_HEAD(tmp_list);
1216 LIST_HEAD(check_list);
1217
1218 list_splice_init(work_q, &tmp_list);
1219
1220 while (!list_empty(&tmp_list)) {
1221 struct scsi_cmnd *next, *scmd;
1222 int rtn;
1223 unsigned int id;
1224
1225 scmd = list_entry(tmp_list.next, struct scsi_cmnd, eh_entry);
1226 id = scmd_id(scmd);
1227
1228 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending target reset "
1229 "to target %d\n",
1230 current->comm, id));
1231 rtn = scsi_try_target_reset(scmd);
1232 if (rtn != SUCCESS && rtn != FAST_IO_FAIL)
1233 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Target reset"
1234 " failed target: "
1235 "%d\n",
1236 current->comm, id));
1237 list_for_each_entry_safe(scmd, next, &tmp_list, eh_entry) {
1238 if (scmd_id(scmd) != id)
1239 continue;
1240
1241 if (rtn == SUCCESS)
1242 list_move_tail(&scmd->eh_entry, &check_list);
1243 else if (rtn == FAST_IO_FAIL)
1244 scsi_eh_finish_cmd(scmd, done_q);
1245 else
1246 /* push back on work queue for further processing */
1247 list_move(&scmd->eh_entry, work_q);
1248 }
1249 }
1250
1251 return scsi_eh_test_devices(&check_list, work_q, done_q, 0);
1252}
1253
1254/**
1255 * scsi_eh_bus_reset - send a bus reset
1256 * @shost: &scsi host being recovered.
1257 * @work_q: &list_head for pending commands.
1258 * @done_q: &list_head for processed commands.
1259 */
1260static int scsi_eh_bus_reset(struct Scsi_Host *shost,
1261 struct list_head *work_q,
1262 struct list_head *done_q)
1263{
1264 struct scsi_cmnd *scmd, *chan_scmd, *next;
1265 LIST_HEAD(check_list);
1266 unsigned int channel;
1267 int rtn;
1268
1269 /*
1270 * we really want to loop over the various channels, and do this on
1271 * a channel by channel basis. we should also check to see if any
1272 * of the failed commands are on soft_reset devices, and if so, skip
1273 * the reset.
1274 */
1275
1276 for (channel = 0; channel <= shost->max_channel; channel++) {
1277 chan_scmd = NULL;
1278 list_for_each_entry(scmd, work_q, eh_entry) {
1279 if (channel == scmd_channel(scmd)) {
1280 chan_scmd = scmd;
1281 break;
1282 /*
1283 * FIXME add back in some support for
1284 * soft_reset devices.
1285 */
1286 }
1287 }
1288
1289 if (!chan_scmd)
1290 continue;
1291 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BRST chan:"
1292 " %d\n", current->comm,
1293 channel));
1294 rtn = scsi_try_bus_reset(chan_scmd);
1295 if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
1296 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1297 if (channel == scmd_channel(scmd)) {
1298 if (rtn == FAST_IO_FAIL)
1299 scsi_eh_finish_cmd(scmd,
1300 done_q);
1301 else
1302 list_move_tail(&scmd->eh_entry,
1303 &check_list);
1304 }
1305 }
1306 } else {
1307 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BRST"
1308 " failed chan: %d\n",
1309 current->comm,
1310 channel));
1311 }
1312 }
1313 return scsi_eh_test_devices(&check_list, work_q, done_q, 0);
1314}
1315
1316/**
1317 * scsi_eh_host_reset - send a host reset
1318 * @work_q: list_head for processed commands.
1319 * @done_q: list_head for processed commands.
1320 */
1321static int scsi_eh_host_reset(struct list_head *work_q,
1322 struct list_head *done_q)
1323{
1324 struct scsi_cmnd *scmd, *next;
1325 LIST_HEAD(check_list);
1326 int rtn;
1327
1328 if (!list_empty(work_q)) {
1329 scmd = list_entry(work_q->next,
1330 struct scsi_cmnd, eh_entry);
1331
1332 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending HRST\n"
1333 , current->comm));
1334
1335 rtn = scsi_try_host_reset(scmd);
1336 if (rtn == SUCCESS) {
1337 list_splice_init(work_q, &check_list);
1338 } else if (rtn == FAST_IO_FAIL) {
1339 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1340 scsi_eh_finish_cmd(scmd, done_q);
1341 }
1342 } else {
1343 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: HRST"
1344 " failed\n",
1345 current->comm));
1346 }
1347 }
1348 return scsi_eh_test_devices(&check_list, work_q, done_q, 1);
1349}
1350
1351/**
1352 * scsi_eh_offline_sdevs - offline scsi devices that fail to recover
1353 * @work_q: list_head for processed commands.
1354 * @done_q: list_head for processed commands.
1355 */
1356static void scsi_eh_offline_sdevs(struct list_head *work_q,
1357 struct list_head *done_q)
1358{
1359 struct scsi_cmnd *scmd, *next;
1360
1361 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1362 sdev_printk(KERN_INFO, scmd->device, "Device offlined - "
1363 "not ready after error recovery\n");
1364 scsi_device_set_state(scmd->device, SDEV_OFFLINE);
1365 if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD) {
1366 /*
1367 * FIXME: Handle lost cmds.
1368 */
1369 }
1370 scsi_eh_finish_cmd(scmd, done_q);
1371 }
1372 return;
1373}
1374
1375/**
1376 * scsi_noretry_cmd - determinte if command should be failed fast
1377 * @scmd: SCSI cmd to examine.
1378 */
1379int scsi_noretry_cmd(struct scsi_cmnd *scmd)
1380{
1381 switch (host_byte(scmd->result)) {
1382 case DID_OK:
1383 break;
1384 case DID_BUS_BUSY:
1385 return (scmd->request->cmd_flags & REQ_FAILFAST_TRANSPORT);
1386 case DID_PARITY:
1387 return (scmd->request->cmd_flags & REQ_FAILFAST_DEV);
1388 case DID_ERROR:
1389 if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
1390 status_byte(scmd->result) == RESERVATION_CONFLICT)
1391 return 0;
1392 /* fall through */
1393 case DID_SOFT_ERROR:
1394 return (scmd->request->cmd_flags & REQ_FAILFAST_DRIVER);
1395 }
1396
1397 switch (status_byte(scmd->result)) {
1398 case CHECK_CONDITION:
1399 /*
1400 * assume caller has checked sense and determinted
1401 * the check condition was retryable.
1402 */
1403 if (scmd->request->cmd_flags & REQ_FAILFAST_DEV ||
1404 scmd->request->cmd_type == REQ_TYPE_BLOCK_PC)
1405 return 1;
1406 }
1407
1408 return 0;
1409}
1410
1411/**
1412 * scsi_decide_disposition - Disposition a cmd on return from LLD.
1413 * @scmd: SCSI cmd to examine.
1414 *
1415 * Notes:
1416 * This is *only* called when we are examining the status after sending
1417 * out the actual data command. any commands that are queued for error
1418 * recovery (e.g. test_unit_ready) do *not* come through here.
1419 *
1420 * When this routine returns failed, it means the error handler thread
1421 * is woken. In cases where the error code indicates an error that
1422 * doesn't require the error handler read (i.e. we don't need to
1423 * abort/reset), this function should return SUCCESS.
1424 */
1425int scsi_decide_disposition(struct scsi_cmnd *scmd)
1426{
1427 int rtn;
1428
1429 /*
1430 * if the device is offline, then we clearly just pass the result back
1431 * up to the top level.
1432 */
1433 if (!scsi_device_online(scmd->device)) {
1434 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: device offline - report"
1435 " as SUCCESS\n",
1436 __func__));
1437 return SUCCESS;
1438 }
1439
1440 /*
1441 * first check the host byte, to see if there is anything in there
1442 * that would indicate what we need to do.
1443 */
1444 switch (host_byte(scmd->result)) {
1445 case DID_PASSTHROUGH:
1446 /*
1447 * no matter what, pass this through to the upper layer.
1448 * nuke this special code so that it looks like we are saying
1449 * did_ok.
1450 */
1451 scmd->result &= 0xff00ffff;
1452 return SUCCESS;
1453 case DID_OK:
1454 /*
1455 * looks good. drop through, and check the next byte.
1456 */
1457 break;
1458 case DID_NO_CONNECT:
1459 case DID_BAD_TARGET:
1460 case DID_ABORT:
1461 /*
1462 * note - this means that we just report the status back
1463 * to the top level driver, not that we actually think
1464 * that it indicates SUCCESS.
1465 */
1466 return SUCCESS;
1467 /*
1468 * when the low level driver returns did_soft_error,
1469 * it is responsible for keeping an internal retry counter
1470 * in order to avoid endless loops (db)
1471 *
1472 * actually this is a bug in this function here. we should
1473 * be mindful of the maximum number of retries specified
1474 * and not get stuck in a loop.
1475 */
1476 case DID_SOFT_ERROR:
1477 goto maybe_retry;
1478 case DID_IMM_RETRY:
1479 return NEEDS_RETRY;
1480
1481 case DID_REQUEUE:
1482 return ADD_TO_MLQUEUE;
1483 case DID_TRANSPORT_DISRUPTED:
1484 /*
1485 * LLD/transport was disrupted during processing of the IO.
1486 * The transport class is now blocked/blocking,
1487 * and the transport will decide what to do with the IO
1488 * based on its timers and recovery capablilities if
1489 * there are enough retries.
1490 */
1491 goto maybe_retry;
1492 case DID_TRANSPORT_FAILFAST:
1493 /*
1494 * The transport decided to failfast the IO (most likely
1495 * the fast io fail tmo fired), so send IO directly upwards.
1496 */
1497 return SUCCESS;
1498 case DID_ERROR:
1499 if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
1500 status_byte(scmd->result) == RESERVATION_CONFLICT)
1501 /*
1502 * execute reservation conflict processing code
1503 * lower down
1504 */
1505 break;
1506 /* fallthrough */
1507 case DID_BUS_BUSY:
1508 case DID_PARITY:
1509 goto maybe_retry;
1510 case DID_TIME_OUT:
1511 /*
1512 * when we scan the bus, we get timeout messages for
1513 * these commands if there is no device available.
1514 * other hosts report did_no_connect for the same thing.
1515 */
1516 if ((scmd->cmnd[0] == TEST_UNIT_READY ||
1517 scmd->cmnd[0] == INQUIRY)) {
1518 return SUCCESS;
1519 } else {
1520 return FAILED;
1521 }
1522 case DID_RESET:
1523 return SUCCESS;
1524 default:
1525 return FAILED;
1526 }
1527
1528 /*
1529 * next, check the message byte.
1530 */
1531 if (msg_byte(scmd->result) != COMMAND_COMPLETE)
1532 return FAILED;
1533
1534 /*
1535 * check the status byte to see if this indicates anything special.
1536 */
1537 switch (status_byte(scmd->result)) {
1538 case QUEUE_FULL:
1539 scsi_handle_queue_full(scmd->device);
1540 /*
1541 * the case of trying to send too many commands to a
1542 * tagged queueing device.
1543 */
1544 case BUSY:
1545 /*
1546 * device can't talk to us at the moment. Should only
1547 * occur (SAM-3) when the task queue is empty, so will cause
1548 * the empty queue handling to trigger a stall in the
1549 * device.
1550 */
1551 return ADD_TO_MLQUEUE;
1552 case GOOD:
1553 scsi_handle_queue_ramp_up(scmd->device);
1554 case COMMAND_TERMINATED:
1555 return SUCCESS;
1556 case TASK_ABORTED:
1557 goto maybe_retry;
1558 case CHECK_CONDITION:
1559 rtn = scsi_check_sense(scmd);
1560 if (rtn == NEEDS_RETRY)
1561 goto maybe_retry;
1562 else if (rtn == TARGET_ERROR) {
1563 /*
1564 * Need to modify host byte to signal a
1565 * permanent target failure
1566 */
1567 set_host_byte(scmd, DID_TARGET_FAILURE);
1568 rtn = SUCCESS;
1569 }
1570 /* if rtn == FAILED, we have no sense information;
1571 * returning FAILED will wake the error handler thread
1572 * to collect the sense and redo the decide
1573 * disposition */
1574 return rtn;
1575 case CONDITION_GOOD:
1576 case INTERMEDIATE_GOOD:
1577 case INTERMEDIATE_C_GOOD:
1578 case ACA_ACTIVE:
1579 /*
1580 * who knows? FIXME(eric)
1581 */
1582 return SUCCESS;
1583
1584 case RESERVATION_CONFLICT:
1585 sdev_printk(KERN_INFO, scmd->device,
1586 "reservation conflict\n");
1587 set_host_byte(scmd, DID_NEXUS_FAILURE);
1588 return SUCCESS; /* causes immediate i/o error */
1589 default:
1590 return FAILED;
1591 }
1592 return FAILED;
1593
1594 maybe_retry:
1595
1596 /* we requeue for retry because the error was retryable, and
1597 * the request was not marked fast fail. Note that above,
1598 * even if the request is marked fast fail, we still requeue
1599 * for queue congestion conditions (QUEUE_FULL or BUSY) */
1600 if ((++scmd->retries) <= scmd->allowed
1601 && !scsi_noretry_cmd(scmd)) {
1602 return NEEDS_RETRY;
1603 } else {
1604 /*
1605 * no more retries - report this one back to upper level.
1606 */
1607 return SUCCESS;
1608 }
1609}
1610
1611static void eh_lock_door_done(struct request *req, int uptodate)
1612{
1613 __blk_put_request(req->q, req);
1614}
1615
1616/**
1617 * scsi_eh_lock_door - Prevent medium removal for the specified device
1618 * @sdev: SCSI device to prevent medium removal
1619 *
1620 * Locking:
1621 * We must be called from process context.
1622 *
1623 * Notes:
1624 * We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the
1625 * head of the devices request queue, and continue.
1626 */
1627static void scsi_eh_lock_door(struct scsi_device *sdev)
1628{
1629 struct request *req;
1630
1631 /*
1632 * blk_get_request with GFP_KERNEL (__GFP_WAIT) sleeps until a
1633 * request becomes available
1634 */
1635 req = blk_get_request(sdev->request_queue, READ, GFP_KERNEL);
1636
1637 req->cmd[0] = ALLOW_MEDIUM_REMOVAL;
1638 req->cmd[1] = 0;
1639 req->cmd[2] = 0;
1640 req->cmd[3] = 0;
1641 req->cmd[4] = SCSI_REMOVAL_PREVENT;
1642 req->cmd[5] = 0;
1643
1644 req->cmd_len = COMMAND_SIZE(req->cmd[0]);
1645
1646 req->cmd_type = REQ_TYPE_BLOCK_PC;
1647 req->cmd_flags |= REQ_QUIET;
1648 req->timeout = 10 * HZ;
1649 req->retries = 5;
1650
1651 blk_execute_rq_nowait(req->q, NULL, req, 1, eh_lock_door_done);
1652}
1653
1654/**
1655 * scsi_restart_operations - restart io operations to the specified host.
1656 * @shost: Host we are restarting.
1657 *
1658 * Notes:
1659 * When we entered the error handler, we blocked all further i/o to
1660 * this device. we need to 'reverse' this process.
1661 */
1662static void scsi_restart_operations(struct Scsi_Host *shost)
1663{
1664 struct scsi_device *sdev;
1665 unsigned long flags;
1666
1667 /*
1668 * If the door was locked, we need to insert a door lock request
1669 * onto the head of the SCSI request queue for the device. There
1670 * is no point trying to lock the door of an off-line device.
1671 */
1672 shost_for_each_device(sdev, shost) {
1673 if (scsi_device_online(sdev) && sdev->locked)
1674 scsi_eh_lock_door(sdev);
1675 }
1676
1677 /*
1678 * next free up anything directly waiting upon the host. this
1679 * will be requests for character device operations, and also for
1680 * ioctls to queued block devices.
1681 */
1682 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: waking up host to restart\n",
1683 __func__));
1684
1685 spin_lock_irqsave(shost->host_lock, flags);
1686 if (scsi_host_set_state(shost, SHOST_RUNNING))
1687 if (scsi_host_set_state(shost, SHOST_CANCEL))
1688 BUG_ON(scsi_host_set_state(shost, SHOST_DEL));
1689 spin_unlock_irqrestore(shost->host_lock, flags);
1690
1691 wake_up(&shost->host_wait);
1692
1693 /*
1694 * finally we need to re-initiate requests that may be pending. we will
1695 * have had everything blocked while error handling is taking place, and
1696 * now that error recovery is done, we will need to ensure that these
1697 * requests are started.
1698 */
1699 scsi_run_host_queues(shost);
1700
1701 /*
1702 * if eh is active and host_eh_scheduled is pending we need to re-run
1703 * recovery. we do this check after scsi_run_host_queues() to allow
1704 * everything pent up since the last eh run a chance to make forward
1705 * progress before we sync again. Either we'll immediately re-run
1706 * recovery or scsi_device_unbusy() will wake us again when these
1707 * pending commands complete.
1708 */
1709 spin_lock_irqsave(shost->host_lock, flags);
1710 if (shost->host_eh_scheduled)
1711 if (scsi_host_set_state(shost, SHOST_RECOVERY))
1712 WARN_ON(scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY));
1713 spin_unlock_irqrestore(shost->host_lock, flags);
1714}
1715
1716/**
1717 * scsi_eh_ready_devs - check device ready state and recover if not.
1718 * @shost: host to be recovered.
1719 * @work_q: &list_head for pending commands.
1720 * @done_q: &list_head for processed commands.
1721 */
1722void scsi_eh_ready_devs(struct Scsi_Host *shost,
1723 struct list_head *work_q,
1724 struct list_head *done_q)
1725{
1726 if (!scsi_eh_stu(shost, work_q, done_q))
1727 if (!scsi_eh_bus_device_reset(shost, work_q, done_q))
1728 if (!scsi_eh_target_reset(shost, work_q, done_q))
1729 if (!scsi_eh_bus_reset(shost, work_q, done_q))
1730 if (!scsi_eh_host_reset(work_q, done_q))
1731 scsi_eh_offline_sdevs(work_q,
1732 done_q);
1733}
1734EXPORT_SYMBOL_GPL(scsi_eh_ready_devs);
1735
1736/**
1737 * scsi_eh_flush_done_q - finish processed commands or retry them.
1738 * @done_q: list_head of processed commands.
1739 */
1740void scsi_eh_flush_done_q(struct list_head *done_q)
1741{
1742 struct scsi_cmnd *scmd, *next;
1743
1744 list_for_each_entry_safe(scmd, next, done_q, eh_entry) {
1745 list_del_init(&scmd->eh_entry);
1746 if (scsi_device_online(scmd->device) &&
1747 !scsi_noretry_cmd(scmd) &&
1748 (++scmd->retries <= scmd->allowed)) {
1749 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush"
1750 " retry cmd: %p\n",
1751 current->comm,
1752 scmd));
1753 scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY);
1754 } else {
1755 /*
1756 * If just we got sense for the device (called
1757 * scsi_eh_get_sense), scmd->result is already
1758 * set, do not set DRIVER_TIMEOUT.
1759 */
1760 if (!scmd->result)
1761 scmd->result |= (DRIVER_TIMEOUT << 24);
1762 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush finish"
1763 " cmd: %p\n",
1764 current->comm, scmd));
1765 scsi_finish_command(scmd);
1766 }
1767 }
1768}
1769EXPORT_SYMBOL(scsi_eh_flush_done_q);
1770
1771/**
1772 * scsi_unjam_host - Attempt to fix a host which has a cmd that failed.
1773 * @shost: Host to unjam.
1774 *
1775 * Notes:
1776 * When we come in here, we *know* that all commands on the bus have
1777 * either completed, failed or timed out. we also know that no further
1778 * commands are being sent to the host, so things are relatively quiet
1779 * and we have freedom to fiddle with things as we wish.
1780 *
1781 * This is only the *default* implementation. it is possible for
1782 * individual drivers to supply their own version of this function, and
1783 * if the maintainer wishes to do this, it is strongly suggested that
1784 * this function be taken as a template and modified. this function
1785 * was designed to correctly handle problems for about 95% of the
1786 * different cases out there, and it should always provide at least a
1787 * reasonable amount of error recovery.
1788 *
1789 * Any command marked 'failed' or 'timeout' must eventually have
1790 * scsi_finish_cmd() called for it. we do all of the retry stuff
1791 * here, so when we restart the host after we return it should have an
1792 * empty queue.
1793 */
1794static void scsi_unjam_host(struct Scsi_Host *shost)
1795{
1796 unsigned long flags;
1797 LIST_HEAD(eh_work_q);
1798 LIST_HEAD(eh_done_q);
1799
1800 spin_lock_irqsave(shost->host_lock, flags);
1801 list_splice_init(&shost->eh_cmd_q, &eh_work_q);
1802 spin_unlock_irqrestore(shost->host_lock, flags);
1803
1804 SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(shost, &eh_work_q));
1805
1806 if (!scsi_eh_get_sense(&eh_work_q, &eh_done_q))
1807 if (!scsi_eh_abort_cmds(&eh_work_q, &eh_done_q))
1808 scsi_eh_ready_devs(shost, &eh_work_q, &eh_done_q);
1809
1810 scsi_eh_flush_done_q(&eh_done_q);
1811}
1812
1813/**
1814 * scsi_error_handler - SCSI error handler thread
1815 * @data: Host for which we are running.
1816 *
1817 * Notes:
1818 * This is the main error handling loop. This is run as a kernel thread
1819 * for every SCSI host and handles all error handling activity.
1820 */
1821int scsi_error_handler(void *data)
1822{
1823 struct Scsi_Host *shost = data;
1824
1825 /*
1826 * We use TASK_INTERRUPTIBLE so that the thread is not
1827 * counted against the load average as a running process.
1828 * We never actually get interrupted because kthread_run
1829 * disables signal delivery for the created thread.
1830 */
1831 set_current_state(TASK_INTERRUPTIBLE);
1832 while (!kthread_should_stop()) {
1833 if ((shost->host_failed == 0 && shost->host_eh_scheduled == 0) ||
1834 shost->host_failed != shost->host_busy) {
1835 SCSI_LOG_ERROR_RECOVERY(1,
1836 printk("Error handler scsi_eh_%d sleeping\n",
1837 shost->host_no));
1838 schedule();
1839 set_current_state(TASK_INTERRUPTIBLE);
1840 continue;
1841 }
1842
1843 __set_current_state(TASK_RUNNING);
1844 SCSI_LOG_ERROR_RECOVERY(1,
1845 printk("Error handler scsi_eh_%d waking up\n",
1846 shost->host_no));
1847
1848 /*
1849 * We have a host that is failing for some reason. Figure out
1850 * what we need to do to get it up and online again (if we can).
1851 * If we fail, we end up taking the thing offline.
1852 */
1853 if (!shost->eh_noresume && scsi_autopm_get_host(shost) != 0) {
1854 SCSI_LOG_ERROR_RECOVERY(1,
1855 printk(KERN_ERR "Error handler scsi_eh_%d "
1856 "unable to autoresume\n",
1857 shost->host_no));
1858 continue;
1859 }
1860
1861 if (shost->transportt->eh_strategy_handler)
1862 shost->transportt->eh_strategy_handler(shost);
1863 else
1864 scsi_unjam_host(shost);
1865
1866 /*
1867 * Note - if the above fails completely, the action is to take
1868 * individual devices offline and flush the queue of any
1869 * outstanding requests that may have been pending. When we
1870 * restart, we restart any I/O to any other devices on the bus
1871 * which are still online.
1872 */
1873 scsi_restart_operations(shost);
1874 if (!shost->eh_noresume)
1875 scsi_autopm_put_host(shost);
1876 set_current_state(TASK_INTERRUPTIBLE);
1877 }
1878 __set_current_state(TASK_RUNNING);
1879
1880 SCSI_LOG_ERROR_RECOVERY(1,
1881 printk("Error handler scsi_eh_%d exiting\n", shost->host_no));
1882 shost->ehandler = NULL;
1883 return 0;
1884}
1885
1886/*
1887 * Function: scsi_report_bus_reset()
1888 *
1889 * Purpose: Utility function used by low-level drivers to report that
1890 * they have observed a bus reset on the bus being handled.
1891 *
1892 * Arguments: shost - Host in question
1893 * channel - channel on which reset was observed.
1894 *
1895 * Returns: Nothing
1896 *
1897 * Lock status: Host lock must be held.
1898 *
1899 * Notes: This only needs to be called if the reset is one which
1900 * originates from an unknown location. Resets originated
1901 * by the mid-level itself don't need to call this, but there
1902 * should be no harm.
1903 *
1904 * The main purpose of this is to make sure that a CHECK_CONDITION
1905 * is properly treated.
1906 */
1907void scsi_report_bus_reset(struct Scsi_Host *shost, int channel)
1908{
1909 struct scsi_device *sdev;
1910
1911 __shost_for_each_device(sdev, shost) {
1912 if (channel == sdev_channel(sdev))
1913 __scsi_report_device_reset(sdev, NULL);
1914 }
1915}
1916EXPORT_SYMBOL(scsi_report_bus_reset);
1917
1918/*
1919 * Function: scsi_report_device_reset()
1920 *
1921 * Purpose: Utility function used by low-level drivers to report that
1922 * they have observed a device reset on the device being handled.
1923 *
1924 * Arguments: shost - Host in question
1925 * channel - channel on which reset was observed
1926 * target - target on which reset was observed
1927 *
1928 * Returns: Nothing
1929 *
1930 * Lock status: Host lock must be held
1931 *
1932 * Notes: This only needs to be called if the reset is one which
1933 * originates from an unknown location. Resets originated
1934 * by the mid-level itself don't need to call this, but there
1935 * should be no harm.
1936 *
1937 * The main purpose of this is to make sure that a CHECK_CONDITION
1938 * is properly treated.
1939 */
1940void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
1941{
1942 struct scsi_device *sdev;
1943
1944 __shost_for_each_device(sdev, shost) {
1945 if (channel == sdev_channel(sdev) &&
1946 target == sdev_id(sdev))
1947 __scsi_report_device_reset(sdev, NULL);
1948 }
1949}
1950EXPORT_SYMBOL(scsi_report_device_reset);
1951
1952static void
1953scsi_reset_provider_done_command(struct scsi_cmnd *scmd)
1954{
1955}
1956
1957/*
1958 * Function: scsi_reset_provider
1959 *
1960 * Purpose: Send requested reset to a bus or device at any phase.
1961 *
1962 * Arguments: device - device to send reset to
1963 * flag - reset type (see scsi.h)
1964 *
1965 * Returns: SUCCESS/FAILURE.
1966 *
1967 * Notes: This is used by the SCSI Generic driver to provide
1968 * Bus/Device reset capability.
1969 */
1970int
1971scsi_reset_provider(struct scsi_device *dev, int flag)
1972{
1973 struct scsi_cmnd *scmd;
1974 struct Scsi_Host *shost = dev->host;
1975 struct request req;
1976 unsigned long flags;
1977 int rtn;
1978
1979 if (scsi_autopm_get_host(shost) < 0)
1980 return FAILED;
1981
1982 scmd = scsi_get_command(dev, GFP_KERNEL);
1983 blk_rq_init(NULL, &req);
1984 scmd->request = &req;
1985
1986 scmd->cmnd = req.cmd;
1987
1988 scmd->scsi_done = scsi_reset_provider_done_command;
1989 memset(&scmd->sdb, 0, sizeof(scmd->sdb));
1990
1991 scmd->cmd_len = 0;
1992
1993 scmd->sc_data_direction = DMA_BIDIRECTIONAL;
1994
1995 spin_lock_irqsave(shost->host_lock, flags);
1996 shost->tmf_in_progress = 1;
1997 spin_unlock_irqrestore(shost->host_lock, flags);
1998
1999 switch (flag) {
2000 case SCSI_TRY_RESET_DEVICE:
2001 rtn = scsi_try_bus_device_reset(scmd);
2002 if (rtn == SUCCESS)
2003 break;
2004 /* FALLTHROUGH */
2005 case SCSI_TRY_RESET_TARGET:
2006 rtn = scsi_try_target_reset(scmd);
2007 if (rtn == SUCCESS)
2008 break;
2009 /* FALLTHROUGH */
2010 case SCSI_TRY_RESET_BUS:
2011 rtn = scsi_try_bus_reset(scmd);
2012 if (rtn == SUCCESS)
2013 break;
2014 /* FALLTHROUGH */
2015 case SCSI_TRY_RESET_HOST:
2016 rtn = scsi_try_host_reset(scmd);
2017 break;
2018 default:
2019 rtn = FAILED;
2020 }
2021
2022 spin_lock_irqsave(shost->host_lock, flags);
2023 shost->tmf_in_progress = 0;
2024 spin_unlock_irqrestore(shost->host_lock, flags);
2025
2026 /*
2027 * be sure to wake up anyone who was sleeping or had their queue
2028 * suspended while we performed the TMF.
2029 */
2030 SCSI_LOG_ERROR_RECOVERY(3,
2031 printk("%s: waking up host to restart after TMF\n",
2032 __func__));
2033
2034 wake_up(&shost->host_wait);
2035
2036 scsi_run_host_queues(shost);
2037
2038 scsi_next_command(scmd);
2039 scsi_autopm_put_host(shost);
2040 return rtn;
2041}
2042EXPORT_SYMBOL(scsi_reset_provider);
2043
2044/**
2045 * scsi_normalize_sense - normalize main elements from either fixed or
2046 * descriptor sense data format into a common format.
2047 *
2048 * @sense_buffer: byte array containing sense data returned by device
2049 * @sb_len: number of valid bytes in sense_buffer
2050 * @sshdr: pointer to instance of structure that common
2051 * elements are written to.
2052 *
2053 * Notes:
2054 * The "main elements" from sense data are: response_code, sense_key,
2055 * asc, ascq and additional_length (only for descriptor format).
2056 *
2057 * Typically this function can be called after a device has
2058 * responded to a SCSI command with the CHECK_CONDITION status.
2059 *
2060 * Return value:
2061 * 1 if valid sense data information found, else 0;
2062 */
2063int scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
2064 struct scsi_sense_hdr *sshdr)
2065{
2066 if (!sense_buffer || !sb_len)
2067 return 0;
2068
2069 memset(sshdr, 0, sizeof(struct scsi_sense_hdr));
2070
2071 sshdr->response_code = (sense_buffer[0] & 0x7f);
2072
2073 if (!scsi_sense_valid(sshdr))
2074 return 0;
2075
2076 if (sshdr->response_code >= 0x72) {
2077 /*
2078 * descriptor format
2079 */
2080 if (sb_len > 1)
2081 sshdr->sense_key = (sense_buffer[1] & 0xf);
2082 if (sb_len > 2)
2083 sshdr->asc = sense_buffer[2];
2084 if (sb_len > 3)
2085 sshdr->ascq = sense_buffer[3];
2086 if (sb_len > 7)
2087 sshdr->additional_length = sense_buffer[7];
2088 } else {
2089 /*
2090 * fixed format
2091 */
2092 if (sb_len > 2)
2093 sshdr->sense_key = (sense_buffer[2] & 0xf);
2094 if (sb_len > 7) {
2095 sb_len = (sb_len < (sense_buffer[7] + 8)) ?
2096 sb_len : (sense_buffer[7] + 8);
2097 if (sb_len > 12)
2098 sshdr->asc = sense_buffer[12];
2099 if (sb_len > 13)
2100 sshdr->ascq = sense_buffer[13];
2101 }
2102 }
2103
2104 return 1;
2105}
2106EXPORT_SYMBOL(scsi_normalize_sense);
2107
2108int scsi_command_normalize_sense(struct scsi_cmnd *cmd,
2109 struct scsi_sense_hdr *sshdr)
2110{
2111 return scsi_normalize_sense(cmd->sense_buffer,
2112 SCSI_SENSE_BUFFERSIZE, sshdr);
2113}
2114EXPORT_SYMBOL(scsi_command_normalize_sense);
2115
2116/**
2117 * scsi_sense_desc_find - search for a given descriptor type in descriptor sense data format.
2118 * @sense_buffer: byte array of descriptor format sense data
2119 * @sb_len: number of valid bytes in sense_buffer
2120 * @desc_type: value of descriptor type to find
2121 * (e.g. 0 -> information)
2122 *
2123 * Notes:
2124 * only valid when sense data is in descriptor format
2125 *
2126 * Return value:
2127 * pointer to start of (first) descriptor if found else NULL
2128 */
2129const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
2130 int desc_type)
2131{
2132 int add_sen_len, add_len, desc_len, k;
2133 const u8 * descp;
2134
2135 if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7])))
2136 return NULL;
2137 if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73))
2138 return NULL;
2139 add_sen_len = (add_sen_len < (sb_len - 8)) ?
2140 add_sen_len : (sb_len - 8);
2141 descp = &sense_buffer[8];
2142 for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) {
2143 descp += desc_len;
2144 add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
2145 desc_len = add_len + 2;
2146 if (descp[0] == desc_type)
2147 return descp;
2148 if (add_len < 0) // short descriptor ??
2149 break;
2150 }
2151 return NULL;
2152}
2153EXPORT_SYMBOL(scsi_sense_desc_find);
2154
2155/**
2156 * scsi_get_sense_info_fld - get information field from sense data (either fixed or descriptor format)
2157 * @sense_buffer: byte array of sense data
2158 * @sb_len: number of valid bytes in sense_buffer
2159 * @info_out: pointer to 64 integer where 8 or 4 byte information
2160 * field will be placed if found.
2161 *
2162 * Return value:
2163 * 1 if information field found, 0 if not found.
2164 */
2165int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len,
2166 u64 * info_out)
2167{
2168 int j;
2169 const u8 * ucp;
2170 u64 ull;
2171
2172 if (sb_len < 7)
2173 return 0;
2174 switch (sense_buffer[0] & 0x7f) {
2175 case 0x70:
2176 case 0x71:
2177 if (sense_buffer[0] & 0x80) {
2178 *info_out = (sense_buffer[3] << 24) +
2179 (sense_buffer[4] << 16) +
2180 (sense_buffer[5] << 8) + sense_buffer[6];
2181 return 1;
2182 } else
2183 return 0;
2184 case 0x72:
2185 case 0x73:
2186 ucp = scsi_sense_desc_find(sense_buffer, sb_len,
2187 0 /* info desc */);
2188 if (ucp && (0xa == ucp[1])) {
2189 ull = 0;
2190 for (j = 0; j < 8; ++j) {
2191 if (j > 0)
2192 ull <<= 8;
2193 ull |= ucp[4 + j];
2194 }
2195 *info_out = ull;
2196 return 1;
2197 } else
2198 return 0;
2199 default:
2200 return 0;
2201 }
2202}
2203EXPORT_SYMBOL(scsi_get_sense_info_fld);
2204
2205/**
2206 * scsi_build_sense_buffer - build sense data in a buffer
2207 * @desc: Sense format (non zero == descriptor format,
2208 * 0 == fixed format)
2209 * @buf: Where to build sense data
2210 * @key: Sense key
2211 * @asc: Additional sense code
2212 * @ascq: Additional sense code qualifier
2213 *
2214 **/
2215void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq)
2216{
2217 if (desc) {
2218 buf[0] = 0x72; /* descriptor, current */
2219 buf[1] = key;
2220 buf[2] = asc;
2221 buf[3] = ascq;
2222 buf[7] = 0;
2223 } else {
2224 buf[0] = 0x70; /* fixed, current */
2225 buf[2] = key;
2226 buf[7] = 0xa;
2227 buf[12] = asc;
2228 buf[13] = ascq;
2229 }
2230}
2231EXPORT_SYMBOL(scsi_build_sense_buffer);