Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0-only
2 : /*
3 : * scsi_error.c Copyright (C) 1997 Eric Youngdale
4 : *
5 : * SCSI error/timeout handling
6 : * Initial versions: Eric Youngdale. Based upon conversations with
7 : * Leonard Zubkoff and David Miller at Linux Expo,
8 : * ideas originating from all over the place.
9 : *
10 : * Restructured scsi_unjam_host and associated functions.
11 : * September 04, 2002 Mike Anderson (andmike@us.ibm.com)
12 : *
13 : * Forward port of Russell King's (rmk@arm.linux.org.uk) changes and
14 : * minor cleanups.
15 : * September 30, 2002 Mike Anderson (andmike@us.ibm.com)
16 : */
17 :
18 : #include <linux/module.h>
19 : #include <linux/sched.h>
20 : #include <linux/gfp.h>
21 : #include <linux/timer.h>
22 : #include <linux/string.h>
23 : #include <linux/kernel.h>
24 : #include <linux/freezer.h>
25 : #include <linux/kthread.h>
26 : #include <linux/interrupt.h>
27 : #include <linux/blkdev.h>
28 : #include <linux/delay.h>
29 : #include <linux/jiffies.h>
30 :
31 : #include <scsi/scsi.h>
32 : #include <scsi/scsi_cmnd.h>
33 : #include <scsi/scsi_dbg.h>
34 : #include <scsi/scsi_device.h>
35 : #include <scsi/scsi_driver.h>
36 : #include <scsi/scsi_eh.h>
37 : #include <scsi/scsi_common.h>
38 : #include <scsi/scsi_transport.h>
39 : #include <scsi/scsi_host.h>
40 : #include <scsi/scsi_ioctl.h>
41 : #include <scsi/scsi_dh.h>
42 : #include <scsi/scsi_devinfo.h>
43 : #include <scsi/sg.h>
44 :
45 : #include "scsi_priv.h"
46 : #include "scsi_logging.h"
47 : #include "scsi_transport_api.h"
48 :
49 : #include <trace/events/scsi.h>
50 :
51 : #include <asm/unaligned.h>
52 :
53 : static void scsi_eh_done(struct scsi_cmnd *scmd);
54 :
55 : /*
56 : * These should *probably* be handled by the host itself.
57 : * Since it is allowed to sleep, it probably should.
58 : */
59 : #define BUS_RESET_SETTLE_TIME (10)
60 : #define HOST_RESET_SETTLE_TIME (10)
61 :
62 : static int scsi_eh_try_stu(struct scsi_cmnd *scmd);
63 : static int scsi_try_to_abort_cmd(struct scsi_host_template *,
64 : struct scsi_cmnd *);
65 :
66 0 : void scsi_eh_wakeup(struct Scsi_Host *shost)
67 : {
68 0 : lockdep_assert_held(shost->host_lock);
69 :
70 0 : if (scsi_host_busy(shost) == shost->host_failed) {
71 0 : trace_scsi_eh_wakeup(shost);
72 0 : wake_up_process(shost->ehandler);
73 0 : SCSI_LOG_ERROR_RECOVERY(5, shost_printk(KERN_INFO, shost,
74 0 : "Waking error handler thread\n"));
75 : }
76 0 : }
77 :
78 : /**
79 : * scsi_schedule_eh - schedule EH for SCSI host
80 : * @shost: SCSI host to invoke error handling on.
81 : *
82 : * Schedule SCSI EH without scmd.
83 : */
84 0 : void scsi_schedule_eh(struct Scsi_Host *shost)
85 : {
86 0 : unsigned long flags;
87 :
88 0 : spin_lock_irqsave(shost->host_lock, flags);
89 :
90 0 : if (scsi_host_set_state(shost, SHOST_RECOVERY) == 0 ||
91 0 : scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY) == 0) {
92 0 : shost->host_eh_scheduled++;
93 0 : scsi_eh_wakeup(shost);
94 : }
95 :
96 0 : spin_unlock_irqrestore(shost->host_lock, flags);
97 0 : }
98 : EXPORT_SYMBOL_GPL(scsi_schedule_eh);
99 :
100 0 : static int scsi_host_eh_past_deadline(struct Scsi_Host *shost)
101 : {
102 0 : if (!shost->last_reset || shost->eh_deadline == -1)
103 : return 0;
104 :
105 : /*
106 : * 32bit accesses are guaranteed to be atomic
107 : * (on all supported architectures), so instead
108 : * of using a spinlock we can as well double check
109 : * if eh_deadline has been set to 'off' during the
110 : * time_before call.
111 : */
112 0 : if (time_before(jiffies, shost->last_reset + shost->eh_deadline) &&
113 : shost->eh_deadline > -1)
114 0 : return 0;
115 :
116 : return 1;
117 : }
118 :
119 0 : static bool scsi_cmd_retry_allowed(struct scsi_cmnd *cmd)
120 : {
121 0 : if (cmd->allowed == SCSI_CMD_RETRIES_NO_LIMIT)
122 : return true;
123 :
124 0 : return ++cmd->retries <= cmd->allowed;
125 : }
126 :
127 0 : static bool scsi_eh_should_retry_cmd(struct scsi_cmnd *cmd)
128 : {
129 0 : struct scsi_device *sdev = cmd->device;
130 0 : struct Scsi_Host *host = sdev->host;
131 :
132 0 : if (host->hostt->eh_should_retry_cmd)
133 0 : return host->hostt->eh_should_retry_cmd(cmd);
134 :
135 : return true;
136 : }
137 :
138 : /**
139 : * scmd_eh_abort_handler - Handle command aborts
140 : * @work: command to be aborted.
141 : *
142 : * Note: this function must be called only for a command that has timed out.
143 : * Because the block layer marks a request as complete before it calls
144 : * scsi_times_out(), a .scsi_done() call from the LLD for a command that has
145 : * timed out do not have any effect. Hence it is safe to call
146 : * scsi_finish_command() from this function.
147 : */
148 : void
149 0 : scmd_eh_abort_handler(struct work_struct *work)
150 : {
151 0 : struct scsi_cmnd *scmd =
152 0 : container_of(work, struct scsi_cmnd, abort_work.work);
153 0 : struct scsi_device *sdev = scmd->device;
154 0 : int rtn;
155 :
156 0 : if (scsi_host_eh_past_deadline(sdev->host)) {
157 : SCSI_LOG_ERROR_RECOVERY(3,
158 : scmd_printk(KERN_INFO, scmd,
159 : "eh timeout, not aborting\n"));
160 : } else {
161 0 : SCSI_LOG_ERROR_RECOVERY(3,
162 : scmd_printk(KERN_INFO, scmd,
163 0 : "aborting command\n"));
164 0 : rtn = scsi_try_to_abort_cmd(sdev->host->hostt, scmd);
165 0 : if (rtn == SUCCESS) {
166 0 : set_host_byte(scmd, DID_TIME_OUT);
167 0 : if (scsi_host_eh_past_deadline(sdev->host)) {
168 : SCSI_LOG_ERROR_RECOVERY(3,
169 : scmd_printk(KERN_INFO, scmd,
170 : "eh timeout, not retrying "
171 : "aborted command\n"));
172 0 : } else if (!scsi_noretry_cmd(scmd) &&
173 0 : scsi_cmd_retry_allowed(scmd) &&
174 0 : scsi_eh_should_retry_cmd(scmd)) {
175 0 : SCSI_LOG_ERROR_RECOVERY(3,
176 : scmd_printk(KERN_WARNING, scmd,
177 0 : "retry aborted command\n"));
178 0 : scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY);
179 0 : return;
180 : } else {
181 0 : SCSI_LOG_ERROR_RECOVERY(3,
182 : scmd_printk(KERN_WARNING, scmd,
183 0 : "finish aborted command\n"));
184 0 : scsi_finish_command(scmd);
185 0 : return;
186 : }
187 : } else {
188 0 : SCSI_LOG_ERROR_RECOVERY(3,
189 : scmd_printk(KERN_INFO, scmd,
190 : "cmd abort %s\n",
191 : (rtn == FAST_IO_FAIL) ?
192 0 : "not send" : "failed"));
193 : }
194 : }
195 :
196 0 : scsi_eh_scmd_add(scmd);
197 : }
198 :
199 : /**
200 : * scsi_abort_command - schedule a command abort
201 : * @scmd: scmd to abort.
202 : *
203 : * We only need to abort commands after a command timeout
204 : */
205 : static int
206 0 : scsi_abort_command(struct scsi_cmnd *scmd)
207 : {
208 0 : struct scsi_device *sdev = scmd->device;
209 0 : struct Scsi_Host *shost = sdev->host;
210 0 : unsigned long flags;
211 :
212 0 : if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) {
213 : /*
214 : * Retry after abort failed, escalate to next level.
215 : */
216 0 : SCSI_LOG_ERROR_RECOVERY(3,
217 : scmd_printk(KERN_INFO, scmd,
218 0 : "previous abort failed\n"));
219 0 : BUG_ON(delayed_work_pending(&scmd->abort_work));
220 : return FAILED;
221 : }
222 :
223 0 : spin_lock_irqsave(shost->host_lock, flags);
224 0 : if (shost->eh_deadline != -1 && !shost->last_reset)
225 0 : shost->last_reset = jiffies;
226 0 : spin_unlock_irqrestore(shost->host_lock, flags);
227 :
228 0 : scmd->eh_eflags |= SCSI_EH_ABORT_SCHEDULED;
229 0 : SCSI_LOG_ERROR_RECOVERY(3,
230 0 : scmd_printk(KERN_INFO, scmd, "abort scheduled\n"));
231 0 : queue_delayed_work(shost->tmf_work_q, &scmd->abort_work, HZ / 100);
232 0 : return SUCCESS;
233 : }
234 :
235 : /**
236 : * scsi_eh_reset - call into ->eh_action to reset internal counters
237 : * @scmd: scmd to run eh on.
238 : *
239 : * The scsi driver might be carrying internal state about the
240 : * devices, so we need to call into the driver to reset the
241 : * internal state once the error handler is started.
242 : */
243 0 : static void scsi_eh_reset(struct scsi_cmnd *scmd)
244 : {
245 0 : if (!blk_rq_is_passthrough(scmd->request)) {
246 0 : struct scsi_driver *sdrv = scsi_cmd_to_driver(scmd);
247 0 : if (sdrv->eh_reset)
248 0 : sdrv->eh_reset(scmd);
249 : }
250 0 : }
251 :
252 0 : static void scsi_eh_inc_host_failed(struct rcu_head *head)
253 : {
254 0 : struct scsi_cmnd *scmd = container_of(head, typeof(*scmd), rcu);
255 0 : struct Scsi_Host *shost = scmd->device->host;
256 0 : unsigned long flags;
257 :
258 0 : spin_lock_irqsave(shost->host_lock, flags);
259 0 : shost->host_failed++;
260 0 : scsi_eh_wakeup(shost);
261 0 : spin_unlock_irqrestore(shost->host_lock, flags);
262 0 : }
263 :
264 : /**
265 : * scsi_eh_scmd_add - add scsi cmd to error handling.
266 : * @scmd: scmd to run eh on.
267 : */
268 0 : void scsi_eh_scmd_add(struct scsi_cmnd *scmd)
269 : {
270 0 : struct Scsi_Host *shost = scmd->device->host;
271 0 : unsigned long flags;
272 0 : int ret;
273 :
274 0 : WARN_ON_ONCE(!shost->ehandler);
275 :
276 0 : spin_lock_irqsave(shost->host_lock, flags);
277 0 : if (scsi_host_set_state(shost, SHOST_RECOVERY)) {
278 0 : ret = scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY);
279 0 : WARN_ON_ONCE(ret);
280 : }
281 0 : if (shost->eh_deadline != -1 && !shost->last_reset)
282 0 : shost->last_reset = jiffies;
283 :
284 0 : scsi_eh_reset(scmd);
285 0 : list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q);
286 0 : spin_unlock_irqrestore(shost->host_lock, flags);
287 : /*
288 : * Ensure that all tasks observe the host state change before the
289 : * host_failed change.
290 : */
291 0 : call_rcu(&scmd->rcu, scsi_eh_inc_host_failed);
292 0 : }
293 :
294 : /**
295 : * scsi_times_out - Timeout function for normal scsi commands.
296 : * @req: request that is timing out.
297 : *
298 : * Notes:
299 : * We do not need to lock this. There is the potential for a race
300 : * only in that the normal completion handling might run, but if the
301 : * normal completion function determines that the timer has already
302 : * fired, then it mustn't do anything.
303 : */
304 0 : enum blk_eh_timer_return scsi_times_out(struct request *req)
305 : {
306 0 : struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(req);
307 0 : enum blk_eh_timer_return rtn = BLK_EH_DONE;
308 0 : struct Scsi_Host *host = scmd->device->host;
309 :
310 0 : trace_scsi_dispatch_cmd_timeout(scmd);
311 0 : scsi_log_completion(scmd, TIMEOUT_ERROR);
312 :
313 0 : if (host->eh_deadline != -1 && !host->last_reset)
314 0 : host->last_reset = jiffies;
315 :
316 0 : if (host->hostt->eh_timed_out)
317 0 : rtn = host->hostt->eh_timed_out(scmd);
318 :
319 0 : if (rtn == BLK_EH_DONE) {
320 : /*
321 : * Set the command to complete first in order to prevent a real
322 : * completion from releasing the command while error handling
323 : * is using it. If the command was already completed, then the
324 : * lower level driver beat the timeout handler, and it is safe
325 : * to return without escalating error recovery.
326 : *
327 : * If timeout handling lost the race to a real completion, the
328 : * block layer may ignore that due to a fake timeout injection,
329 : * so return RESET_TIMER to allow error handling another shot
330 : * at this command.
331 : */
332 0 : if (test_and_set_bit(SCMD_STATE_COMPLETE, &scmd->state))
333 : return BLK_EH_RESET_TIMER;
334 0 : if (scsi_abort_command(scmd) != SUCCESS) {
335 0 : set_host_byte(scmd, DID_TIME_OUT);
336 0 : scsi_eh_scmd_add(scmd);
337 : }
338 : }
339 :
340 : return rtn;
341 : }
342 :
343 : /**
344 : * scsi_block_when_processing_errors - Prevent cmds from being queued.
345 : * @sdev: Device on which we are performing recovery.
346 : *
347 : * Description:
348 : * We block until the host is out of error recovery, and then check to
349 : * see whether the host or the device is offline.
350 : *
351 : * Return value:
352 : * 0 when dev was taken offline by error recovery. 1 OK to proceed.
353 : */
354 0 : int scsi_block_when_processing_errors(struct scsi_device *sdev)
355 : {
356 0 : int online;
357 :
358 0 : wait_event(sdev->host->host_wait, !scsi_host_in_recovery(sdev->host));
359 :
360 0 : online = scsi_device_online(sdev);
361 :
362 0 : return online;
363 : }
364 : EXPORT_SYMBOL(scsi_block_when_processing_errors);
365 :
366 : #ifdef CONFIG_SCSI_LOGGING
367 : /**
368 : * scsi_eh_prt_fail_stats - Log info on failures.
369 : * @shost: scsi host being recovered.
370 : * @work_q: Queue of scsi cmds to process.
371 : */
372 : static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost,
373 : struct list_head *work_q)
374 : {
375 : struct scsi_cmnd *scmd;
376 : struct scsi_device *sdev;
377 : int total_failures = 0;
378 : int cmd_failed = 0;
379 : int cmd_cancel = 0;
380 : int devices_failed = 0;
381 :
382 : shost_for_each_device(sdev, shost) {
383 : list_for_each_entry(scmd, work_q, eh_entry) {
384 : if (scmd->device == sdev) {
385 : ++total_failures;
386 : if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED)
387 : ++cmd_cancel;
388 : else
389 : ++cmd_failed;
390 : }
391 : }
392 :
393 : if (cmd_cancel || cmd_failed) {
394 : SCSI_LOG_ERROR_RECOVERY(3,
395 : shost_printk(KERN_INFO, shost,
396 : "%s: cmds failed: %d, cancel: %d\n",
397 : __func__, cmd_failed,
398 : cmd_cancel));
399 : cmd_cancel = 0;
400 : cmd_failed = 0;
401 : ++devices_failed;
402 : }
403 : }
404 :
405 : SCSI_LOG_ERROR_RECOVERY(2, shost_printk(KERN_INFO, shost,
406 : "Total of %d commands on %d"
407 : " devices require eh work\n",
408 : total_failures, devices_failed));
409 : }
410 : #endif
411 :
412 : /**
413 : * scsi_report_lun_change - Set flag on all *other* devices on the same target
414 : * to indicate that a UNIT ATTENTION is expected.
415 : * @sdev: Device reporting the UNIT ATTENTION
416 : */
417 0 : static void scsi_report_lun_change(struct scsi_device *sdev)
418 : {
419 0 : sdev->sdev_target->expecting_lun_change = 1;
420 : }
421 :
422 : /**
423 : * scsi_report_sense - Examine scsi sense information and log messages for
424 : * certain conditions, also issue uevents for some of them.
425 : * @sdev: Device reporting the sense code
426 : * @sshdr: sshdr to be examined
427 : */
428 0 : static void scsi_report_sense(struct scsi_device *sdev,
429 : struct scsi_sense_hdr *sshdr)
430 : {
431 0 : enum scsi_device_event evt_type = SDEV_EVT_MAXBITS; /* i.e. none */
432 :
433 0 : if (sshdr->sense_key == UNIT_ATTENTION) {
434 0 : if (sshdr->asc == 0x3f && sshdr->ascq == 0x03) {
435 0 : evt_type = SDEV_EVT_INQUIRY_CHANGE_REPORTED;
436 0 : sdev_printk(KERN_WARNING, sdev,
437 : "Inquiry data has changed");
438 0 : } else if (sshdr->asc == 0x3f && sshdr->ascq == 0x0e) {
439 0 : evt_type = SDEV_EVT_LUN_CHANGE_REPORTED;
440 0 : scsi_report_lun_change(sdev);
441 0 : sdev_printk(KERN_WARNING, sdev,
442 : "Warning! Received an indication that the "
443 : "LUN assignments on this target have "
444 : "changed. The Linux SCSI layer does not "
445 : "automatically remap LUN assignments.\n");
446 0 : } else if (sshdr->asc == 0x3f)
447 0 : sdev_printk(KERN_WARNING, sdev,
448 : "Warning! Received an indication that the "
449 : "operating parameters on this target have "
450 : "changed. The Linux SCSI layer does not "
451 : "automatically adjust these parameters.\n");
452 :
453 0 : if (sshdr->asc == 0x38 && sshdr->ascq == 0x07) {
454 0 : evt_type = SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED;
455 0 : sdev_printk(KERN_WARNING, sdev,
456 : "Warning! Received an indication that the "
457 : "LUN reached a thin provisioning soft "
458 : "threshold.\n");
459 : }
460 :
461 0 : if (sshdr->asc == 0x29) {
462 0 : evt_type = SDEV_EVT_POWER_ON_RESET_OCCURRED;
463 0 : sdev_printk(KERN_WARNING, sdev,
464 : "Power-on or device reset occurred\n");
465 : }
466 :
467 0 : if (sshdr->asc == 0x2a && sshdr->ascq == 0x01) {
468 0 : evt_type = SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED;
469 0 : sdev_printk(KERN_WARNING, sdev,
470 : "Mode parameters changed");
471 0 : } else if (sshdr->asc == 0x2a && sshdr->ascq == 0x06) {
472 0 : evt_type = SDEV_EVT_ALUA_STATE_CHANGE_REPORTED;
473 0 : sdev_printk(KERN_WARNING, sdev,
474 : "Asymmetric access state changed");
475 0 : } else if (sshdr->asc == 0x2a && sshdr->ascq == 0x09) {
476 0 : evt_type = SDEV_EVT_CAPACITY_CHANGE_REPORTED;
477 0 : sdev_printk(KERN_WARNING, sdev,
478 : "Capacity data has changed");
479 0 : } else if (sshdr->asc == 0x2a)
480 0 : sdev_printk(KERN_WARNING, sdev,
481 : "Parameters changed");
482 : }
483 :
484 0 : if (evt_type != SDEV_EVT_MAXBITS) {
485 0 : set_bit(evt_type, sdev->pending_events);
486 0 : schedule_work(&sdev->event_work);
487 : }
488 0 : }
489 :
490 : /**
491 : * scsi_check_sense - Examine scsi cmd sense
492 : * @scmd: Cmd to have sense checked.
493 : *
494 : * Return value:
495 : * SUCCESS or FAILED or NEEDS_RETRY or ADD_TO_MLQUEUE
496 : *
497 : * Notes:
498 : * When a deferred error is detected the current command has
499 : * not been executed and needs retrying.
500 : */
501 0 : int scsi_check_sense(struct scsi_cmnd *scmd)
502 : {
503 0 : struct scsi_device *sdev = scmd->device;
504 0 : struct scsi_sense_hdr sshdr;
505 :
506 0 : if (! scsi_command_normalize_sense(scmd, &sshdr))
507 : return FAILED; /* no valid sense data */
508 :
509 0 : scsi_report_sense(sdev, &sshdr);
510 :
511 0 : if (scsi_sense_is_deferred(&sshdr))
512 : return NEEDS_RETRY;
513 :
514 0 : if (sdev->handler && sdev->handler->check_sense) {
515 0 : int rc;
516 :
517 0 : rc = sdev->handler->check_sense(sdev, &sshdr);
518 0 : if (rc != SCSI_RETURN_NOT_HANDLED)
519 : return rc;
520 : /* handler does not care. Drop down to default handling */
521 : }
522 :
523 0 : if (scmd->cmnd[0] == TEST_UNIT_READY && scmd->scsi_done != scsi_eh_done)
524 : /*
525 : * nasty: for mid-layer issued TURs, we need to return the
526 : * actual sense data without any recovery attempt. For eh
527 : * issued ones, we need to try to recover and interpret
528 : */
529 : return SUCCESS;
530 :
531 : /*
532 : * Previous logic looked for FILEMARK, EOM or ILI which are
533 : * mainly associated with tapes and returned SUCCESS.
534 : */
535 0 : if (sshdr.response_code == 0x70) {
536 : /* fixed format */
537 0 : if (scmd->sense_buffer[2] & 0xe0)
538 : return SUCCESS;
539 : } else {
540 : /*
541 : * descriptor format: look for "stream commands sense data
542 : * descriptor" (see SSC-3). Assume single sense data
543 : * descriptor. Ignore ILI from SBC-2 READ LONG and WRITE LONG.
544 : */
545 0 : if ((sshdr.additional_length > 3) &&
546 0 : (scmd->sense_buffer[8] == 0x4) &&
547 0 : (scmd->sense_buffer[11] & 0xe0))
548 : return SUCCESS;
549 : }
550 :
551 0 : switch (sshdr.sense_key) {
552 : case NO_SENSE:
553 : return SUCCESS;
554 : case RECOVERED_ERROR:
555 : return /* soft_error */ SUCCESS;
556 :
557 0 : case ABORTED_COMMAND:
558 0 : if (sshdr.asc == 0x10) /* DIF */
559 : return SUCCESS;
560 :
561 0 : if (sshdr.asc == 0x44 && sdev->sdev_bflags & BLIST_RETRY_ITF)
562 : return ADD_TO_MLQUEUE;
563 0 : if (sshdr.asc == 0xc1 && sshdr.ascq == 0x01 &&
564 0 : sdev->sdev_bflags & BLIST_RETRY_ASC_C1)
565 0 : return ADD_TO_MLQUEUE;
566 :
567 : return NEEDS_RETRY;
568 0 : case NOT_READY:
569 : case UNIT_ATTENTION:
570 : /*
571 : * if we are expecting a cc/ua because of a bus reset that we
572 : * performed, treat this just as a retry. otherwise this is
573 : * information that we should pass up to the upper-level driver
574 : * so that we can deal with it there.
575 : */
576 0 : if (scmd->device->expecting_cc_ua) {
577 : /*
578 : * Because some device does not queue unit
579 : * attentions correctly, we carefully check
580 : * additional sense code and qualifier so as
581 : * not to squash media change unit attention.
582 : */
583 0 : if (sshdr.asc != 0x28 || sshdr.ascq != 0x00) {
584 0 : scmd->device->expecting_cc_ua = 0;
585 0 : return NEEDS_RETRY;
586 : }
587 : }
588 : /*
589 : * we might also expect a cc/ua if another LUN on the target
590 : * reported a UA with an ASC/ASCQ of 3F 0E -
591 : * REPORTED LUNS DATA HAS CHANGED.
592 : */
593 0 : if (scmd->device->sdev_target->expecting_lun_change &&
594 0 : sshdr.asc == 0x3f && sshdr.ascq == 0x0e)
595 : return NEEDS_RETRY;
596 : /*
597 : * if the device is in the process of becoming ready, we
598 : * should retry.
599 : */
600 0 : if ((sshdr.asc == 0x04) && (sshdr.ascq == 0x01))
601 : return NEEDS_RETRY;
602 : /*
603 : * if the device is not started, we need to wake
604 : * the error handler to start the motor
605 : */
606 0 : if (scmd->device->allow_restart &&
607 0 : (sshdr.asc == 0x04) && (sshdr.ascq == 0x02))
608 0 : return FAILED;
609 : /*
610 : * Pass the UA upwards for a determination in the completion
611 : * functions.
612 : */
613 : return SUCCESS;
614 :
615 : /* these are not supported */
616 0 : case DATA_PROTECT:
617 0 : if (sshdr.asc == 0x27 && sshdr.ascq == 0x07) {
618 : /* Thin provisioning hard threshold reached */
619 0 : set_host_byte(scmd, DID_ALLOC_FAILURE);
620 0 : return SUCCESS;
621 : }
622 0 : fallthrough;
623 : case COPY_ABORTED:
624 : case VOLUME_OVERFLOW:
625 : case MISCOMPARE:
626 : case BLANK_CHECK:
627 0 : set_host_byte(scmd, DID_TARGET_FAILURE);
628 0 : return SUCCESS;
629 :
630 0 : case MEDIUM_ERROR:
631 0 : if (sshdr.asc == 0x11 || /* UNRECOVERED READ ERR */
632 0 : sshdr.asc == 0x13 || /* AMNF DATA FIELD */
633 : sshdr.asc == 0x14) { /* RECORD NOT FOUND */
634 0 : set_host_byte(scmd, DID_MEDIUM_ERROR);
635 0 : return SUCCESS;
636 : }
637 : return NEEDS_RETRY;
638 :
639 0 : case HARDWARE_ERROR:
640 0 : if (scmd->device->retry_hwerror)
641 : return ADD_TO_MLQUEUE;
642 : else
643 0 : set_host_byte(scmd, DID_TARGET_FAILURE);
644 0 : fallthrough;
645 :
646 0 : case ILLEGAL_REQUEST:
647 0 : if (sshdr.asc == 0x20 || /* Invalid command operation code */
648 : sshdr.asc == 0x21 || /* Logical block address out of range */
649 0 : sshdr.asc == 0x22 || /* Invalid function */
650 0 : sshdr.asc == 0x24 || /* Invalid field in cdb */
651 0 : sshdr.asc == 0x26 || /* Parameter value invalid */
652 : sshdr.asc == 0x27) { /* Write protected */
653 0 : set_host_byte(scmd, DID_TARGET_FAILURE);
654 : }
655 : return SUCCESS;
656 :
657 : default:
658 : return SUCCESS;
659 : }
660 : }
661 : EXPORT_SYMBOL_GPL(scsi_check_sense);
662 :
663 0 : static void scsi_handle_queue_ramp_up(struct scsi_device *sdev)
664 : {
665 0 : struct scsi_host_template *sht = sdev->host->hostt;
666 0 : struct scsi_device *tmp_sdev;
667 :
668 0 : if (!sht->track_queue_depth ||
669 0 : sdev->queue_depth >= sdev->max_queue_depth)
670 : return;
671 :
672 0 : if (time_before(jiffies,
673 : sdev->last_queue_ramp_up + sdev->queue_ramp_up_period))
674 : return;
675 :
676 0 : if (time_before(jiffies,
677 : sdev->last_queue_full_time + sdev->queue_ramp_up_period))
678 : return;
679 :
680 : /*
681 : * Walk all devices of a target and do
682 : * ramp up on them.
683 : */
684 0 : shost_for_each_device(tmp_sdev, sdev->host) {
685 0 : if (tmp_sdev->channel != sdev->channel ||
686 0 : tmp_sdev->id != sdev->id ||
687 0 : tmp_sdev->queue_depth == sdev->max_queue_depth)
688 0 : continue;
689 :
690 0 : scsi_change_queue_depth(tmp_sdev, tmp_sdev->queue_depth + 1);
691 0 : sdev->last_queue_ramp_up = jiffies;
692 : }
693 : }
694 :
695 0 : static void scsi_handle_queue_full(struct scsi_device *sdev)
696 : {
697 0 : struct scsi_host_template *sht = sdev->host->hostt;
698 0 : struct scsi_device *tmp_sdev;
699 :
700 0 : if (!sht->track_queue_depth)
701 : return;
702 :
703 0 : shost_for_each_device(tmp_sdev, sdev->host) {
704 0 : if (tmp_sdev->channel != sdev->channel ||
705 : tmp_sdev->id != sdev->id)
706 0 : continue;
707 : /*
708 : * We do not know the number of commands that were at
709 : * the device when we got the queue full so we start
710 : * from the highest possible value and work our way down.
711 : */
712 0 : scsi_track_queue_full(tmp_sdev, tmp_sdev->queue_depth - 1);
713 : }
714 : }
715 :
716 : /**
717 : * scsi_eh_completed_normally - Disposition a eh cmd on return from LLD.
718 : * @scmd: SCSI cmd to examine.
719 : *
720 : * Notes:
721 : * This is *only* called when we are examining the status of commands
722 : * queued during error recovery. the main difference here is that we
723 : * don't allow for the possibility of retries here, and we are a lot
724 : * more restrictive about what we consider acceptable.
725 : */
726 0 : static int scsi_eh_completed_normally(struct scsi_cmnd *scmd)
727 : {
728 : /*
729 : * first check the host byte, to see if there is anything in there
730 : * that would indicate what we need to do.
731 : */
732 0 : if (host_byte(scmd->result) == DID_RESET) {
733 : /*
734 : * rats. we are already in the error handler, so we now
735 : * get to try and figure out what to do next. if the sense
736 : * is valid, we have a pretty good idea of what to do.
737 : * if not, we mark it as FAILED.
738 : */
739 0 : return scsi_check_sense(scmd);
740 : }
741 0 : if (host_byte(scmd->result) != DID_OK)
742 : return FAILED;
743 :
744 : /*
745 : * next, check the message byte.
746 : */
747 0 : if (msg_byte(scmd->result) != COMMAND_COMPLETE)
748 : return FAILED;
749 :
750 : /*
751 : * now, check the status byte to see if this indicates
752 : * anything special.
753 : */
754 0 : switch (status_byte(scmd->result)) {
755 0 : case GOOD:
756 0 : scsi_handle_queue_ramp_up(scmd->device);
757 : fallthrough;
758 : case COMMAND_TERMINATED:
759 : return SUCCESS;
760 0 : case CHECK_CONDITION:
761 0 : return scsi_check_sense(scmd);
762 : case CONDITION_GOOD:
763 : case INTERMEDIATE_GOOD:
764 : case INTERMEDIATE_C_GOOD:
765 : /*
766 : * who knows? FIXME(eric)
767 : */
768 : return SUCCESS;
769 0 : case RESERVATION_CONFLICT:
770 0 : if (scmd->cmnd[0] == TEST_UNIT_READY)
771 : /* it is a success, we probed the device and
772 : * found it */
773 0 : return SUCCESS;
774 : /* otherwise, we failed to send the command */
775 : return FAILED;
776 0 : case QUEUE_FULL:
777 0 : scsi_handle_queue_full(scmd->device);
778 : fallthrough;
779 : case BUSY:
780 : return NEEDS_RETRY;
781 0 : default:
782 0 : return FAILED;
783 : }
784 : return FAILED;
785 : }
786 :
787 : /**
788 : * scsi_eh_done - Completion function for error handling.
789 : * @scmd: Cmd that is done.
790 : */
791 0 : static void scsi_eh_done(struct scsi_cmnd *scmd)
792 : {
793 0 : struct completion *eh_action;
794 :
795 0 : SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
796 0 : "%s result: %x\n", __func__, scmd->result));
797 :
798 0 : eh_action = scmd->device->host->eh_action;
799 0 : if (eh_action)
800 0 : complete(eh_action);
801 0 : }
802 :
803 : /**
804 : * scsi_try_host_reset - ask host adapter to reset itself
805 : * @scmd: SCSI cmd to send host reset.
806 : */
807 0 : static int scsi_try_host_reset(struct scsi_cmnd *scmd)
808 : {
809 0 : unsigned long flags;
810 0 : int rtn;
811 0 : struct Scsi_Host *host = scmd->device->host;
812 0 : struct scsi_host_template *hostt = host->hostt;
813 :
814 0 : SCSI_LOG_ERROR_RECOVERY(3,
815 0 : shost_printk(KERN_INFO, host, "Snd Host RST\n"));
816 :
817 0 : if (!hostt->eh_host_reset_handler)
818 : return FAILED;
819 :
820 0 : rtn = hostt->eh_host_reset_handler(scmd);
821 :
822 0 : if (rtn == SUCCESS) {
823 0 : if (!hostt->skip_settle_delay)
824 0 : ssleep(HOST_RESET_SETTLE_TIME);
825 0 : spin_lock_irqsave(host->host_lock, flags);
826 0 : scsi_report_bus_reset(host, scmd_channel(scmd));
827 0 : spin_unlock_irqrestore(host->host_lock, flags);
828 : }
829 :
830 : return rtn;
831 : }
832 :
833 : /**
834 : * scsi_try_bus_reset - ask host to perform a bus reset
835 : * @scmd: SCSI cmd to send bus reset.
836 : */
837 0 : static int scsi_try_bus_reset(struct scsi_cmnd *scmd)
838 : {
839 0 : unsigned long flags;
840 0 : int rtn;
841 0 : struct Scsi_Host *host = scmd->device->host;
842 0 : struct scsi_host_template *hostt = host->hostt;
843 :
844 0 : SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
845 0 : "%s: Snd Bus RST\n", __func__));
846 :
847 0 : if (!hostt->eh_bus_reset_handler)
848 : return FAILED;
849 :
850 0 : rtn = hostt->eh_bus_reset_handler(scmd);
851 :
852 0 : if (rtn == SUCCESS) {
853 0 : if (!hostt->skip_settle_delay)
854 0 : ssleep(BUS_RESET_SETTLE_TIME);
855 0 : spin_lock_irqsave(host->host_lock, flags);
856 0 : scsi_report_bus_reset(host, scmd_channel(scmd));
857 0 : spin_unlock_irqrestore(host->host_lock, flags);
858 : }
859 :
860 : return rtn;
861 : }
862 :
863 0 : static void __scsi_report_device_reset(struct scsi_device *sdev, void *data)
864 : {
865 0 : sdev->was_reset = 1;
866 0 : sdev->expecting_cc_ua = 1;
867 0 : }
868 :
869 : /**
870 : * scsi_try_target_reset - Ask host to perform a target reset
871 : * @scmd: SCSI cmd used to send a target reset
872 : *
873 : * Notes:
874 : * There is no timeout for this operation. if this operation is
875 : * unreliable for a given host, then the host itself needs to put a
876 : * timer on it, and set the host back to a consistent state prior to
877 : * returning.
878 : */
879 0 : static int scsi_try_target_reset(struct scsi_cmnd *scmd)
880 : {
881 0 : unsigned long flags;
882 0 : int rtn;
883 0 : struct Scsi_Host *host = scmd->device->host;
884 0 : struct scsi_host_template *hostt = host->hostt;
885 :
886 0 : if (!hostt->eh_target_reset_handler)
887 : return FAILED;
888 :
889 0 : rtn = hostt->eh_target_reset_handler(scmd);
890 0 : if (rtn == SUCCESS) {
891 0 : spin_lock_irqsave(host->host_lock, flags);
892 0 : __starget_for_each_device(scsi_target(scmd->device), NULL,
893 : __scsi_report_device_reset);
894 0 : spin_unlock_irqrestore(host->host_lock, flags);
895 : }
896 :
897 : return rtn;
898 : }
899 :
900 : /**
901 : * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev
902 : * @scmd: SCSI cmd used to send BDR
903 : *
904 : * Notes:
905 : * There is no timeout for this operation. if this operation is
906 : * unreliable for a given host, then the host itself needs to put a
907 : * timer on it, and set the host back to a consistent state prior to
908 : * returning.
909 : */
910 0 : static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd)
911 : {
912 0 : int rtn;
913 0 : struct scsi_host_template *hostt = scmd->device->host->hostt;
914 :
915 0 : if (!hostt->eh_device_reset_handler)
916 : return FAILED;
917 :
918 0 : rtn = hostt->eh_device_reset_handler(scmd);
919 0 : if (rtn == SUCCESS)
920 0 : __scsi_report_device_reset(scmd->device, NULL);
921 : return rtn;
922 : }
923 :
924 : /**
925 : * scsi_try_to_abort_cmd - Ask host to abort a SCSI command
926 : * @hostt: SCSI driver host template
927 : * @scmd: SCSI cmd used to send a target reset
928 : *
929 : * Return value:
930 : * SUCCESS, FAILED, or FAST_IO_FAIL
931 : *
932 : * Notes:
933 : * SUCCESS does not necessarily indicate that the command
934 : * has been aborted; it only indicates that the LLDDs
935 : * has cleared all references to that command.
936 : * LLDDs should return FAILED only if an abort was required
937 : * but could not be executed. LLDDs should return FAST_IO_FAIL
938 : * if the device is temporarily unavailable (eg due to a
939 : * link down on FibreChannel)
940 : */
941 0 : static int scsi_try_to_abort_cmd(struct scsi_host_template *hostt,
942 : struct scsi_cmnd *scmd)
943 : {
944 0 : if (!hostt->eh_abort_handler)
945 : return FAILED;
946 :
947 0 : return hostt->eh_abort_handler(scmd);
948 : }
949 :
950 0 : static void scsi_abort_eh_cmnd(struct scsi_cmnd *scmd)
951 : {
952 0 : if (scsi_try_to_abort_cmd(scmd->device->host->hostt, scmd) != SUCCESS)
953 0 : if (scsi_try_bus_device_reset(scmd) != SUCCESS)
954 0 : if (scsi_try_target_reset(scmd) != SUCCESS)
955 0 : if (scsi_try_bus_reset(scmd) != SUCCESS)
956 0 : scsi_try_host_reset(scmd);
957 0 : }
958 :
959 : /**
960 : * scsi_eh_prep_cmnd - Save a scsi command info as part of error recovery
961 : * @scmd: SCSI command structure to hijack
962 : * @ses: structure to save restore information
963 : * @cmnd: CDB to send. Can be NULL if no new cmnd is needed
964 : * @cmnd_size: size in bytes of @cmnd (must be <= BLK_MAX_CDB)
965 : * @sense_bytes: size of sense data to copy. or 0 (if != 0 @cmnd is ignored)
966 : *
967 : * This function is used to save a scsi command information before re-execution
968 : * as part of the error recovery process. If @sense_bytes is 0 the command
969 : * sent must be one that does not transfer any data. If @sense_bytes != 0
970 : * @cmnd is ignored and this functions sets up a REQUEST_SENSE command
971 : * and cmnd buffers to read @sense_bytes into @scmd->sense_buffer.
972 : */
973 0 : void scsi_eh_prep_cmnd(struct scsi_cmnd *scmd, struct scsi_eh_save *ses,
974 : unsigned char *cmnd, int cmnd_size, unsigned sense_bytes)
975 : {
976 0 : struct scsi_device *sdev = scmd->device;
977 :
978 : /*
979 : * We need saved copies of a number of fields - this is because
980 : * error handling may need to overwrite these with different values
981 : * to run different commands, and once error handling is complete,
982 : * we will need to restore these values prior to running the actual
983 : * command.
984 : */
985 0 : ses->cmd_len = scmd->cmd_len;
986 0 : ses->cmnd = scmd->cmnd;
987 0 : ses->data_direction = scmd->sc_data_direction;
988 0 : ses->sdb = scmd->sdb;
989 0 : ses->result = scmd->result;
990 0 : ses->resid_len = scmd->req.resid_len;
991 0 : ses->underflow = scmd->underflow;
992 0 : ses->prot_op = scmd->prot_op;
993 0 : ses->eh_eflags = scmd->eh_eflags;
994 :
995 0 : scmd->prot_op = SCSI_PROT_NORMAL;
996 0 : scmd->eh_eflags = 0;
997 0 : scmd->cmnd = ses->eh_cmnd;
998 0 : memset(scmd->cmnd, 0, BLK_MAX_CDB);
999 0 : memset(&scmd->sdb, 0, sizeof(scmd->sdb));
1000 0 : scmd->result = 0;
1001 0 : scmd->req.resid_len = 0;
1002 :
1003 0 : if (sense_bytes) {
1004 0 : scmd->sdb.length = min_t(unsigned, SCSI_SENSE_BUFFERSIZE,
1005 : sense_bytes);
1006 0 : sg_init_one(&ses->sense_sgl, scmd->sense_buffer,
1007 : scmd->sdb.length);
1008 0 : scmd->sdb.table.sgl = &ses->sense_sgl;
1009 0 : scmd->sc_data_direction = DMA_FROM_DEVICE;
1010 0 : scmd->sdb.table.nents = scmd->sdb.table.orig_nents = 1;
1011 0 : scmd->cmnd[0] = REQUEST_SENSE;
1012 0 : scmd->cmnd[4] = scmd->sdb.length;
1013 0 : scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
1014 : } else {
1015 0 : scmd->sc_data_direction = DMA_NONE;
1016 0 : if (cmnd) {
1017 0 : BUG_ON(cmnd_size > BLK_MAX_CDB);
1018 0 : memcpy(scmd->cmnd, cmnd, cmnd_size);
1019 0 : scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
1020 : }
1021 : }
1022 :
1023 0 : scmd->underflow = 0;
1024 :
1025 0 : if (sdev->scsi_level <= SCSI_2 && sdev->scsi_level != SCSI_UNKNOWN)
1026 0 : scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) |
1027 0 : (sdev->lun << 5 & 0xe0);
1028 :
1029 : /*
1030 : * Zero the sense buffer. The scsi spec mandates that any
1031 : * untransferred sense data should be interpreted as being zero.
1032 : */
1033 0 : memset(scmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
1034 0 : }
1035 : EXPORT_SYMBOL(scsi_eh_prep_cmnd);
1036 :
1037 : /**
1038 : * scsi_eh_restore_cmnd - Restore a scsi command info as part of error recovery
1039 : * @scmd: SCSI command structure to restore
1040 : * @ses: saved information from a coresponding call to scsi_eh_prep_cmnd
1041 : *
1042 : * Undo any damage done by above scsi_eh_prep_cmnd().
1043 : */
1044 0 : void scsi_eh_restore_cmnd(struct scsi_cmnd* scmd, struct scsi_eh_save *ses)
1045 : {
1046 : /*
1047 : * Restore original data
1048 : */
1049 0 : scmd->cmd_len = ses->cmd_len;
1050 0 : scmd->cmnd = ses->cmnd;
1051 0 : scmd->sc_data_direction = ses->data_direction;
1052 0 : scmd->sdb = ses->sdb;
1053 0 : scmd->result = ses->result;
1054 0 : scmd->req.resid_len = ses->resid_len;
1055 0 : scmd->underflow = ses->underflow;
1056 0 : scmd->prot_op = ses->prot_op;
1057 0 : scmd->eh_eflags = ses->eh_eflags;
1058 0 : }
1059 : EXPORT_SYMBOL(scsi_eh_restore_cmnd);
1060 :
1061 : /**
1062 : * scsi_send_eh_cmnd - submit a scsi command as part of error recovery
1063 : * @scmd: SCSI command structure to hijack
1064 : * @cmnd: CDB to send
1065 : * @cmnd_size: size in bytes of @cmnd
1066 : * @timeout: timeout for this request
1067 : * @sense_bytes: size of sense data to copy or 0
1068 : *
1069 : * This function is used to send a scsi command down to a target device
1070 : * as part of the error recovery process. See also scsi_eh_prep_cmnd() above.
1071 : *
1072 : * Return value:
1073 : * SUCCESS or FAILED or NEEDS_RETRY
1074 : */
1075 0 : static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
1076 : int cmnd_size, int timeout, unsigned sense_bytes)
1077 : {
1078 0 : struct scsi_device *sdev = scmd->device;
1079 0 : struct Scsi_Host *shost = sdev->host;
1080 0 : DECLARE_COMPLETION_ONSTACK(done);
1081 0 : unsigned long timeleft = timeout, delay;
1082 0 : struct scsi_eh_save ses;
1083 0 : const unsigned long stall_for = msecs_to_jiffies(100);
1084 0 : int rtn;
1085 :
1086 0 : retry:
1087 0 : scsi_eh_prep_cmnd(scmd, &ses, cmnd, cmnd_size, sense_bytes);
1088 0 : shost->eh_action = &done;
1089 :
1090 0 : scsi_log_send(scmd);
1091 0 : scmd->scsi_done = scsi_eh_done;
1092 :
1093 : /*
1094 : * Lock sdev->state_mutex to avoid that scsi_device_quiesce() can
1095 : * change the SCSI device state after we have examined it and before
1096 : * .queuecommand() is called.
1097 : */
1098 0 : mutex_lock(&sdev->state_mutex);
1099 0 : while (sdev->sdev_state == SDEV_BLOCK && timeleft > 0) {
1100 0 : mutex_unlock(&sdev->state_mutex);
1101 0 : SCSI_LOG_ERROR_RECOVERY(5, sdev_printk(KERN_DEBUG, sdev,
1102 : "%s: state %d <> %d\n", __func__, sdev->sdev_state,
1103 0 : SDEV_BLOCK));
1104 0 : delay = min(timeleft, stall_for);
1105 0 : timeleft -= delay;
1106 0 : msleep(jiffies_to_msecs(delay));
1107 0 : mutex_lock(&sdev->state_mutex);
1108 : }
1109 0 : if (sdev->sdev_state != SDEV_BLOCK)
1110 0 : rtn = shost->hostt->queuecommand(shost, scmd);
1111 : else
1112 : rtn = SCSI_MLQUEUE_DEVICE_BUSY;
1113 0 : mutex_unlock(&sdev->state_mutex);
1114 :
1115 0 : if (rtn) {
1116 0 : if (timeleft > stall_for) {
1117 0 : scsi_eh_restore_cmnd(scmd, &ses);
1118 0 : timeleft -= stall_for;
1119 0 : msleep(jiffies_to_msecs(stall_for));
1120 0 : goto retry;
1121 : }
1122 : /* signal not to enter either branch of the if () below */
1123 : timeleft = 0;
1124 : rtn = FAILED;
1125 : } else {
1126 0 : timeleft = wait_for_completion_timeout(&done, timeout);
1127 0 : rtn = SUCCESS;
1128 : }
1129 :
1130 0 : shost->eh_action = NULL;
1131 :
1132 0 : scsi_log_completion(scmd, rtn);
1133 :
1134 0 : SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1135 : "%s timeleft: %ld\n",
1136 0 : __func__, timeleft));
1137 :
1138 : /*
1139 : * If there is time left scsi_eh_done got called, and we will examine
1140 : * the actual status codes to see whether the command actually did
1141 : * complete normally, else if we have a zero return and no time left,
1142 : * the command must still be pending, so abort it and return FAILED.
1143 : * If we never actually managed to issue the command, because
1144 : * ->queuecommand() kept returning non zero, use the rtn = FAILED
1145 : * value above (so don't execute either branch of the if)
1146 : */
1147 0 : if (timeleft) {
1148 0 : rtn = scsi_eh_completed_normally(scmd);
1149 0 : SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1150 0 : "%s: scsi_eh_completed_normally %x\n", __func__, rtn));
1151 :
1152 0 : switch (rtn) {
1153 : case SUCCESS:
1154 : case NEEDS_RETRY:
1155 : case FAILED:
1156 : break;
1157 0 : case ADD_TO_MLQUEUE:
1158 0 : rtn = NEEDS_RETRY;
1159 0 : break;
1160 0 : default:
1161 0 : rtn = FAILED;
1162 0 : break;
1163 : }
1164 0 : } else if (rtn != FAILED) {
1165 0 : scsi_abort_eh_cmnd(scmd);
1166 0 : rtn = FAILED;
1167 : }
1168 :
1169 0 : scsi_eh_restore_cmnd(scmd, &ses);
1170 :
1171 0 : return rtn;
1172 : }
1173 :
1174 : /**
1175 : * scsi_request_sense - Request sense data from a particular target.
1176 : * @scmd: SCSI cmd for request sense.
1177 : *
1178 : * Notes:
1179 : * Some hosts automatically obtain this information, others require
1180 : * that we obtain it on our own. This function will *not* return until
1181 : * the command either times out, or it completes.
1182 : */
1183 0 : static int scsi_request_sense(struct scsi_cmnd *scmd)
1184 : {
1185 0 : return scsi_send_eh_cmnd(scmd, NULL, 0, scmd->device->eh_timeout, ~0);
1186 : }
1187 :
1188 0 : static int scsi_eh_action(struct scsi_cmnd *scmd, int rtn)
1189 : {
1190 0 : if (!blk_rq_is_passthrough(scmd->request)) {
1191 0 : struct scsi_driver *sdrv = scsi_cmd_to_driver(scmd);
1192 0 : if (sdrv->eh_action)
1193 0 : rtn = sdrv->eh_action(scmd, rtn);
1194 : }
1195 0 : return rtn;
1196 : }
1197 :
1198 : /**
1199 : * scsi_eh_finish_cmd - Handle a cmd that eh is finished with.
1200 : * @scmd: Original SCSI cmd that eh has finished.
1201 : * @done_q: Queue for processed commands.
1202 : *
1203 : * Notes:
1204 : * We don't want to use the normal command completion while we are are
1205 : * still handling errors - it may cause other commands to be queued,
1206 : * and that would disturb what we are doing. Thus we really want to
1207 : * keep a list of pending commands for final completion, and once we
1208 : * are ready to leave error handling we handle completion for real.
1209 : */
1210 0 : void scsi_eh_finish_cmd(struct scsi_cmnd *scmd, struct list_head *done_q)
1211 : {
1212 0 : list_move_tail(&scmd->eh_entry, done_q);
1213 0 : }
1214 : EXPORT_SYMBOL(scsi_eh_finish_cmd);
1215 :
1216 : /**
1217 : * scsi_eh_get_sense - Get device sense data.
1218 : * @work_q: Queue of commands to process.
1219 : * @done_q: Queue of processed commands.
1220 : *
1221 : * Description:
1222 : * See if we need to request sense information. if so, then get it
1223 : * now, so we have a better idea of what to do.
1224 : *
1225 : * Notes:
1226 : * This has the unfortunate side effect that if a shost adapter does
1227 : * not automatically request sense information, we end up shutting
1228 : * it down before we request it.
1229 : *
1230 : * All drivers should request sense information internally these days,
1231 : * so for now all I have to say is tough noogies if you end up in here.
1232 : *
1233 : * XXX: Long term this code should go away, but that needs an audit of
1234 : * all LLDDs first.
1235 : */
1236 0 : int scsi_eh_get_sense(struct list_head *work_q,
1237 : struct list_head *done_q)
1238 : {
1239 0 : struct scsi_cmnd *scmd, *next;
1240 0 : struct Scsi_Host *shost;
1241 0 : int rtn;
1242 :
1243 : /*
1244 : * If SCSI_EH_ABORT_SCHEDULED has been set, it is timeout IO,
1245 : * should not get sense.
1246 : */
1247 0 : list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1248 0 : if ((scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) ||
1249 0 : SCSI_SENSE_VALID(scmd))
1250 0 : continue;
1251 :
1252 0 : shost = scmd->device->host;
1253 0 : if (scsi_host_eh_past_deadline(shost)) {
1254 : SCSI_LOG_ERROR_RECOVERY(3,
1255 : scmd_printk(KERN_INFO, scmd,
1256 : "%s: skip request sense, past eh deadline\n",
1257 : current->comm));
1258 : break;
1259 : }
1260 0 : if (status_byte(scmd->result) != CHECK_CONDITION)
1261 : /*
1262 : * don't request sense if there's no check condition
1263 : * status because the error we're processing isn't one
1264 : * that has a sense code (and some devices get
1265 : * confused by sense requests out of the blue)
1266 : */
1267 0 : continue;
1268 :
1269 0 : SCSI_LOG_ERROR_RECOVERY(2, scmd_printk(KERN_INFO, scmd,
1270 : "%s: requesting sense\n",
1271 0 : current->comm));
1272 0 : rtn = scsi_request_sense(scmd);
1273 0 : if (rtn != SUCCESS)
1274 0 : continue;
1275 :
1276 0 : SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1277 0 : "sense requested, result %x\n", scmd->result));
1278 0 : SCSI_LOG_ERROR_RECOVERY(3, scsi_print_sense(scmd));
1279 :
1280 0 : rtn = scsi_decide_disposition(scmd);
1281 :
1282 : /*
1283 : * if the result was normal, then just pass it along to the
1284 : * upper level.
1285 : */
1286 0 : if (rtn == SUCCESS)
1287 : /*
1288 : * We don't want this command reissued, just finished
1289 : * with the sense data, so set retries to the max
1290 : * allowed to ensure it won't get reissued. If the user
1291 : * has requested infinite retries, we also want to
1292 : * finish this command, so force completion by setting
1293 : * retries and allowed to the same value.
1294 : */
1295 0 : if (scmd->allowed == SCSI_CMD_RETRIES_NO_LIMIT)
1296 0 : scmd->retries = scmd->allowed = 1;
1297 : else
1298 0 : scmd->retries = scmd->allowed;
1299 0 : else if (rtn != NEEDS_RETRY)
1300 0 : continue;
1301 :
1302 0 : scsi_eh_finish_cmd(scmd, done_q);
1303 : }
1304 :
1305 0 : return list_empty(work_q);
1306 : }
1307 : EXPORT_SYMBOL_GPL(scsi_eh_get_sense);
1308 :
1309 : /**
1310 : * scsi_eh_tur - Send TUR to device.
1311 : * @scmd: &scsi_cmnd to send TUR
1312 : *
1313 : * Return value:
1314 : * 0 - Device is ready. 1 - Device NOT ready.
1315 : */
1316 0 : static int scsi_eh_tur(struct scsi_cmnd *scmd)
1317 : {
1318 0 : static unsigned char tur_command[6] = {TEST_UNIT_READY, 0, 0, 0, 0, 0};
1319 0 : int retry_cnt = 1, rtn;
1320 :
1321 0 : retry_tur:
1322 0 : rtn = scsi_send_eh_cmnd(scmd, tur_command, 6,
1323 0 : scmd->device->eh_timeout, 0);
1324 :
1325 0 : SCSI_LOG_ERROR_RECOVERY(3, scmd_printk(KERN_INFO, scmd,
1326 0 : "%s return: %x\n", __func__, rtn));
1327 :
1328 0 : switch (rtn) {
1329 0 : case NEEDS_RETRY:
1330 0 : if (retry_cnt--)
1331 0 : goto retry_tur;
1332 : fallthrough;
1333 : case SUCCESS:
1334 : return 0;
1335 0 : default:
1336 0 : return 1;
1337 : }
1338 : }
1339 :
1340 : /**
1341 : * scsi_eh_test_devices - check if devices are responding from error recovery.
1342 : * @cmd_list: scsi commands in error recovery.
1343 : * @work_q: queue for commands which still need more error recovery
1344 : * @done_q: queue for commands which are finished
1345 : * @try_stu: boolean on if a STU command should be tried in addition to TUR.
1346 : *
1347 : * Decription:
1348 : * Tests if devices are in a working state. Commands to devices now in
1349 : * a working state are sent to the done_q while commands to devices which
1350 : * are still failing to respond are returned to the work_q for more
1351 : * processing.
1352 : **/
1353 0 : static int scsi_eh_test_devices(struct list_head *cmd_list,
1354 : struct list_head *work_q,
1355 : struct list_head *done_q, int try_stu)
1356 : {
1357 0 : struct scsi_cmnd *scmd, *next;
1358 0 : struct scsi_device *sdev;
1359 0 : int finish_cmds;
1360 :
1361 0 : while (!list_empty(cmd_list)) {
1362 0 : scmd = list_entry(cmd_list->next, struct scsi_cmnd, eh_entry);
1363 0 : sdev = scmd->device;
1364 :
1365 0 : if (!try_stu) {
1366 0 : if (scsi_host_eh_past_deadline(sdev->host)) {
1367 : /* Push items back onto work_q */
1368 0 : list_splice_init(cmd_list, work_q);
1369 : SCSI_LOG_ERROR_RECOVERY(3,
1370 : sdev_printk(KERN_INFO, sdev,
1371 : "%s: skip test device, past eh deadline",
1372 : current->comm));
1373 : break;
1374 : }
1375 : }
1376 :
1377 0 : finish_cmds = !scsi_device_online(scmd->device) ||
1378 0 : (try_stu && !scsi_eh_try_stu(scmd) &&
1379 0 : !scsi_eh_tur(scmd)) ||
1380 0 : !scsi_eh_tur(scmd);
1381 :
1382 0 : list_for_each_entry_safe(scmd, next, cmd_list, eh_entry)
1383 0 : if (scmd->device == sdev) {
1384 0 : if (finish_cmds &&
1385 0 : (try_stu ||
1386 0 : scsi_eh_action(scmd, SUCCESS) == SUCCESS))
1387 0 : scsi_eh_finish_cmd(scmd, done_q);
1388 : else
1389 0 : list_move_tail(&scmd->eh_entry, work_q);
1390 : }
1391 : }
1392 0 : return list_empty(work_q);
1393 : }
1394 :
1395 : /**
1396 : * scsi_eh_try_stu - Send START_UNIT to device.
1397 : * @scmd: &scsi_cmnd to send START_UNIT
1398 : *
1399 : * Return value:
1400 : * 0 - Device is ready. 1 - Device NOT ready.
1401 : */
1402 0 : static int scsi_eh_try_stu(struct scsi_cmnd *scmd)
1403 : {
1404 0 : static unsigned char stu_command[6] = {START_STOP, 0, 0, 0, 1, 0};
1405 :
1406 0 : if (scmd->device->allow_restart) {
1407 : int i, rtn = NEEDS_RETRY;
1408 :
1409 0 : for (i = 0; rtn == NEEDS_RETRY && i < 2; i++)
1410 0 : rtn = scsi_send_eh_cmnd(scmd, stu_command, 6, scmd->device->request_queue->rq_timeout, 0);
1411 :
1412 0 : if (rtn == SUCCESS)
1413 0 : return 0;
1414 : }
1415 :
1416 : return 1;
1417 : }
1418 :
1419 : /**
1420 : * scsi_eh_stu - send START_UNIT if needed
1421 : * @shost: &scsi host being recovered.
1422 : * @work_q: &list_head for pending commands.
1423 : * @done_q: &list_head for processed commands.
1424 : *
1425 : * Notes:
1426 : * If commands are failing due to not ready, initializing command required,
1427 : * try revalidating the device, which will end up sending a start unit.
1428 : */
1429 0 : static int scsi_eh_stu(struct Scsi_Host *shost,
1430 : struct list_head *work_q,
1431 : struct list_head *done_q)
1432 : {
1433 0 : struct scsi_cmnd *scmd, *stu_scmd, *next;
1434 0 : struct scsi_device *sdev;
1435 :
1436 0 : shost_for_each_device(sdev, shost) {
1437 0 : if (scsi_host_eh_past_deadline(shost)) {
1438 0 : SCSI_LOG_ERROR_RECOVERY(3,
1439 : sdev_printk(KERN_INFO, sdev,
1440 : "%s: skip START_UNIT, past eh deadline\n",
1441 0 : current->comm));
1442 0 : scsi_device_put(sdev);
1443 0 : break;
1444 : }
1445 0 : stu_scmd = NULL;
1446 0 : list_for_each_entry(scmd, work_q, eh_entry)
1447 0 : if (scmd->device == sdev && SCSI_SENSE_VALID(scmd) &&
1448 0 : scsi_check_sense(scmd) == FAILED ) {
1449 : stu_scmd = scmd;
1450 : break;
1451 : }
1452 :
1453 0 : if (!stu_scmd)
1454 0 : continue;
1455 :
1456 0 : SCSI_LOG_ERROR_RECOVERY(3,
1457 : sdev_printk(KERN_INFO, sdev,
1458 : "%s: Sending START_UNIT\n",
1459 0 : current->comm));
1460 :
1461 0 : if (!scsi_eh_try_stu(stu_scmd)) {
1462 0 : if (!scsi_device_online(sdev) ||
1463 0 : !scsi_eh_tur(stu_scmd)) {
1464 0 : list_for_each_entry_safe(scmd, next,
1465 : work_q, eh_entry) {
1466 0 : if (scmd->device == sdev &&
1467 0 : scsi_eh_action(scmd, SUCCESS) == SUCCESS)
1468 0 : scsi_eh_finish_cmd(scmd, done_q);
1469 : }
1470 : }
1471 : } else {
1472 0 : SCSI_LOG_ERROR_RECOVERY(3,
1473 : sdev_printk(KERN_INFO, sdev,
1474 : "%s: START_UNIT failed\n",
1475 0 : current->comm));
1476 : }
1477 : }
1478 :
1479 0 : return list_empty(work_q);
1480 : }
1481 :
1482 :
1483 : /**
1484 : * scsi_eh_bus_device_reset - send bdr if needed
1485 : * @shost: scsi host being recovered.
1486 : * @work_q: &list_head for pending commands.
1487 : * @done_q: &list_head for processed commands.
1488 : *
1489 : * Notes:
1490 : * Try a bus device reset. Still, look to see whether we have multiple
1491 : * devices that are jammed or not - if we have multiple devices, it
1492 : * makes no sense to try bus_device_reset - we really would need to try
1493 : * a bus_reset instead.
1494 : */
1495 0 : static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
1496 : struct list_head *work_q,
1497 : struct list_head *done_q)
1498 : {
1499 0 : struct scsi_cmnd *scmd, *bdr_scmd, *next;
1500 0 : struct scsi_device *sdev;
1501 0 : int rtn;
1502 :
1503 0 : shost_for_each_device(sdev, shost) {
1504 0 : if (scsi_host_eh_past_deadline(shost)) {
1505 0 : SCSI_LOG_ERROR_RECOVERY(3,
1506 : sdev_printk(KERN_INFO, sdev,
1507 : "%s: skip BDR, past eh deadline\n",
1508 0 : current->comm));
1509 0 : scsi_device_put(sdev);
1510 0 : break;
1511 : }
1512 0 : bdr_scmd = NULL;
1513 0 : list_for_each_entry(scmd, work_q, eh_entry)
1514 0 : if (scmd->device == sdev) {
1515 : bdr_scmd = scmd;
1516 : break;
1517 : }
1518 :
1519 0 : if (!bdr_scmd)
1520 0 : continue;
1521 :
1522 0 : SCSI_LOG_ERROR_RECOVERY(3,
1523 : sdev_printk(KERN_INFO, sdev,
1524 0 : "%s: Sending BDR\n", current->comm));
1525 0 : rtn = scsi_try_bus_device_reset(bdr_scmd);
1526 0 : if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
1527 0 : if (!scsi_device_online(sdev) ||
1528 0 : rtn == FAST_IO_FAIL ||
1529 0 : !scsi_eh_tur(bdr_scmd)) {
1530 0 : list_for_each_entry_safe(scmd, next,
1531 : work_q, eh_entry) {
1532 0 : if (scmd->device == sdev &&
1533 0 : scsi_eh_action(scmd, rtn) != FAILED)
1534 0 : scsi_eh_finish_cmd(scmd,
1535 : done_q);
1536 : }
1537 : }
1538 : } else {
1539 0 : SCSI_LOG_ERROR_RECOVERY(3,
1540 : sdev_printk(KERN_INFO, sdev,
1541 0 : "%s: BDR failed\n", current->comm));
1542 : }
1543 : }
1544 :
1545 0 : return list_empty(work_q);
1546 : }
1547 :
1548 : /**
1549 : * scsi_eh_target_reset - send target reset if needed
1550 : * @shost: scsi host being recovered.
1551 : * @work_q: &list_head for pending commands.
1552 : * @done_q: &list_head for processed commands.
1553 : *
1554 : * Notes:
1555 : * Try a target reset.
1556 : */
1557 0 : static int scsi_eh_target_reset(struct Scsi_Host *shost,
1558 : struct list_head *work_q,
1559 : struct list_head *done_q)
1560 : {
1561 0 : LIST_HEAD(tmp_list);
1562 0 : LIST_HEAD(check_list);
1563 :
1564 0 : list_splice_init(work_q, &tmp_list);
1565 :
1566 0 : while (!list_empty(&tmp_list)) {
1567 0 : struct scsi_cmnd *next, *scmd;
1568 0 : int rtn;
1569 0 : unsigned int id;
1570 :
1571 0 : if (scsi_host_eh_past_deadline(shost)) {
1572 : /* push back on work queue for further processing */
1573 0 : list_splice_init(&check_list, work_q);
1574 0 : list_splice_init(&tmp_list, work_q);
1575 0 : SCSI_LOG_ERROR_RECOVERY(3,
1576 : shost_printk(KERN_INFO, shost,
1577 : "%s: Skip target reset, past eh deadline\n",
1578 0 : current->comm));
1579 0 : return list_empty(work_q);
1580 : }
1581 :
1582 0 : scmd = list_entry(tmp_list.next, struct scsi_cmnd, eh_entry);
1583 0 : id = scmd_id(scmd);
1584 :
1585 0 : SCSI_LOG_ERROR_RECOVERY(3,
1586 : shost_printk(KERN_INFO, shost,
1587 : "%s: Sending target reset to target %d\n",
1588 0 : current->comm, id));
1589 0 : rtn = scsi_try_target_reset(scmd);
1590 0 : if (rtn != SUCCESS && rtn != FAST_IO_FAIL)
1591 0 : SCSI_LOG_ERROR_RECOVERY(3,
1592 : shost_printk(KERN_INFO, shost,
1593 : "%s: Target reset failed"
1594 : " target: %d\n",
1595 0 : current->comm, id));
1596 0 : list_for_each_entry_safe(scmd, next, &tmp_list, eh_entry) {
1597 0 : if (scmd_id(scmd) != id)
1598 0 : continue;
1599 :
1600 0 : if (rtn == SUCCESS)
1601 0 : list_move_tail(&scmd->eh_entry, &check_list);
1602 0 : else if (rtn == FAST_IO_FAIL)
1603 0 : scsi_eh_finish_cmd(scmd, done_q);
1604 : else
1605 : /* push back on work queue for further processing */
1606 0 : list_move(&scmd->eh_entry, work_q);
1607 : }
1608 : }
1609 :
1610 0 : return scsi_eh_test_devices(&check_list, work_q, done_q, 0);
1611 : }
1612 :
1613 : /**
1614 : * scsi_eh_bus_reset - send a bus reset
1615 : * @shost: &scsi host being recovered.
1616 : * @work_q: &list_head for pending commands.
1617 : * @done_q: &list_head for processed commands.
1618 : */
1619 0 : static int scsi_eh_bus_reset(struct Scsi_Host *shost,
1620 : struct list_head *work_q,
1621 : struct list_head *done_q)
1622 : {
1623 0 : struct scsi_cmnd *scmd, *chan_scmd, *next;
1624 0 : LIST_HEAD(check_list);
1625 0 : unsigned int channel;
1626 0 : int rtn;
1627 :
1628 : /*
1629 : * we really want to loop over the various channels, and do this on
1630 : * a channel by channel basis. we should also check to see if any
1631 : * of the failed commands are on soft_reset devices, and if so, skip
1632 : * the reset.
1633 : */
1634 :
1635 0 : for (channel = 0; channel <= shost->max_channel; channel++) {
1636 0 : if (scsi_host_eh_past_deadline(shost)) {
1637 0 : list_splice_init(&check_list, work_q);
1638 0 : SCSI_LOG_ERROR_RECOVERY(3,
1639 : shost_printk(KERN_INFO, shost,
1640 : "%s: skip BRST, past eh deadline\n",
1641 0 : current->comm));
1642 0 : return list_empty(work_q);
1643 : }
1644 :
1645 0 : chan_scmd = NULL;
1646 0 : list_for_each_entry(scmd, work_q, eh_entry) {
1647 0 : if (channel == scmd_channel(scmd)) {
1648 : chan_scmd = scmd;
1649 : break;
1650 : /*
1651 : * FIXME add back in some support for
1652 : * soft_reset devices.
1653 : */
1654 : }
1655 : }
1656 :
1657 0 : if (!chan_scmd)
1658 0 : continue;
1659 0 : SCSI_LOG_ERROR_RECOVERY(3,
1660 : shost_printk(KERN_INFO, shost,
1661 : "%s: Sending BRST chan: %d\n",
1662 0 : current->comm, channel));
1663 0 : rtn = scsi_try_bus_reset(chan_scmd);
1664 0 : if (rtn == SUCCESS || rtn == FAST_IO_FAIL) {
1665 0 : list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1666 0 : if (channel == scmd_channel(scmd)) {
1667 0 : if (rtn == FAST_IO_FAIL)
1668 0 : scsi_eh_finish_cmd(scmd,
1669 : done_q);
1670 : else
1671 0 : list_move_tail(&scmd->eh_entry,
1672 : &check_list);
1673 : }
1674 : }
1675 : } else {
1676 0 : SCSI_LOG_ERROR_RECOVERY(3,
1677 : shost_printk(KERN_INFO, shost,
1678 : "%s: BRST failed chan: %d\n",
1679 0 : current->comm, channel));
1680 : }
1681 : }
1682 0 : return scsi_eh_test_devices(&check_list, work_q, done_q, 0);
1683 : }
1684 :
1685 : /**
1686 : * scsi_eh_host_reset - send a host reset
1687 : * @shost: host to be reset.
1688 : * @work_q: &list_head for pending commands.
1689 : * @done_q: &list_head for processed commands.
1690 : */
1691 0 : static int scsi_eh_host_reset(struct Scsi_Host *shost,
1692 : struct list_head *work_q,
1693 : struct list_head *done_q)
1694 : {
1695 0 : struct scsi_cmnd *scmd, *next;
1696 0 : LIST_HEAD(check_list);
1697 0 : int rtn;
1698 :
1699 0 : if (!list_empty(work_q)) {
1700 0 : scmd = list_entry(work_q->next,
1701 : struct scsi_cmnd, eh_entry);
1702 :
1703 0 : SCSI_LOG_ERROR_RECOVERY(3,
1704 : shost_printk(KERN_INFO, shost,
1705 : "%s: Sending HRST\n",
1706 0 : current->comm));
1707 :
1708 0 : rtn = scsi_try_host_reset(scmd);
1709 0 : if (rtn == SUCCESS) {
1710 0 : list_splice_init(work_q, &check_list);
1711 0 : } else if (rtn == FAST_IO_FAIL) {
1712 0 : list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1713 0 : scsi_eh_finish_cmd(scmd, done_q);
1714 : }
1715 : } else {
1716 0 : SCSI_LOG_ERROR_RECOVERY(3,
1717 : shost_printk(KERN_INFO, shost,
1718 : "%s: HRST failed\n",
1719 0 : current->comm));
1720 : }
1721 : }
1722 0 : return scsi_eh_test_devices(&check_list, work_q, done_q, 1);
1723 : }
1724 :
1725 : /**
1726 : * scsi_eh_offline_sdevs - offline scsi devices that fail to recover
1727 : * @work_q: &list_head for pending commands.
1728 : * @done_q: &list_head for processed commands.
1729 : */
1730 0 : static void scsi_eh_offline_sdevs(struct list_head *work_q,
1731 : struct list_head *done_q)
1732 : {
1733 0 : struct scsi_cmnd *scmd, *next;
1734 0 : struct scsi_device *sdev;
1735 :
1736 0 : list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
1737 0 : sdev_printk(KERN_INFO, scmd->device, "Device offlined - "
1738 : "not ready after error recovery\n");
1739 0 : sdev = scmd->device;
1740 :
1741 0 : mutex_lock(&sdev->state_mutex);
1742 0 : scsi_device_set_state(sdev, SDEV_OFFLINE);
1743 0 : mutex_unlock(&sdev->state_mutex);
1744 :
1745 0 : scsi_eh_finish_cmd(scmd, done_q);
1746 : }
1747 0 : return;
1748 : }
1749 :
1750 : /**
1751 : * scsi_noretry_cmd - determine if command should be failed fast
1752 : * @scmd: SCSI cmd to examine.
1753 : */
1754 0 : int scsi_noretry_cmd(struct scsi_cmnd *scmd)
1755 : {
1756 0 : switch (host_byte(scmd->result)) {
1757 : case DID_OK:
1758 : break;
1759 0 : case DID_TIME_OUT:
1760 0 : goto check_type;
1761 0 : case DID_BUS_BUSY:
1762 0 : return (scmd->request->cmd_flags & REQ_FAILFAST_TRANSPORT);
1763 0 : case DID_PARITY:
1764 0 : return (scmd->request->cmd_flags & REQ_FAILFAST_DEV);
1765 0 : case DID_ERROR:
1766 0 : if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
1767 0 : status_byte(scmd->result) == RESERVATION_CONFLICT)
1768 : return 0;
1769 0 : fallthrough;
1770 : case DID_SOFT_ERROR:
1771 0 : return (scmd->request->cmd_flags & REQ_FAILFAST_DRIVER);
1772 : }
1773 :
1774 0 : if (status_byte(scmd->result) != CHECK_CONDITION)
1775 : return 0;
1776 :
1777 0 : check_type:
1778 : /*
1779 : * assume caller has checked sense and determined
1780 : * the check condition was retryable.
1781 : */
1782 0 : if (scmd->request->cmd_flags & REQ_FAILFAST_DEV ||
1783 0 : blk_rq_is_passthrough(scmd->request))
1784 0 : return 1;
1785 :
1786 : return 0;
1787 : }
1788 :
1789 : /**
1790 : * scsi_decide_disposition - Disposition a cmd on return from LLD.
1791 : * @scmd: SCSI cmd to examine.
1792 : *
1793 : * Notes:
1794 : * This is *only* called when we are examining the status after sending
1795 : * out the actual data command. any commands that are queued for error
1796 : * recovery (e.g. test_unit_ready) do *not* come through here.
1797 : *
1798 : * When this routine returns failed, it means the error handler thread
1799 : * is woken. In cases where the error code indicates an error that
1800 : * doesn't require the error handler read (i.e. we don't need to
1801 : * abort/reset), this function should return SUCCESS.
1802 : */
1803 0 : int scsi_decide_disposition(struct scsi_cmnd *scmd)
1804 : {
1805 0 : int rtn;
1806 :
1807 : /*
1808 : * if the device is offline, then we clearly just pass the result back
1809 : * up to the top level.
1810 : */
1811 0 : if (!scsi_device_online(scmd->device)) {
1812 : SCSI_LOG_ERROR_RECOVERY(5, scmd_printk(KERN_INFO, scmd,
1813 : "%s: device offline - report as SUCCESS\n", __func__));
1814 : return SUCCESS;
1815 : }
1816 :
1817 : /*
1818 : * first check the host byte, to see if there is anything in there
1819 : * that would indicate what we need to do.
1820 : */
1821 0 : switch (host_byte(scmd->result)) {
1822 0 : case DID_PASSTHROUGH:
1823 : /*
1824 : * no matter what, pass this through to the upper layer.
1825 : * nuke this special code so that it looks like we are saying
1826 : * did_ok.
1827 : */
1828 0 : scmd->result &= 0xff00ffff;
1829 0 : return SUCCESS;
1830 : case DID_OK:
1831 : /*
1832 : * looks good. drop through, and check the next byte.
1833 : */
1834 : break;
1835 0 : case DID_ABORT:
1836 0 : if (scmd->eh_eflags & SCSI_EH_ABORT_SCHEDULED) {
1837 0 : set_host_byte(scmd, DID_TIME_OUT);
1838 0 : return SUCCESS;
1839 : }
1840 : fallthrough;
1841 : case DID_NO_CONNECT:
1842 : case DID_BAD_TARGET:
1843 : /*
1844 : * note - this means that we just report the status back
1845 : * to the top level driver, not that we actually think
1846 : * that it indicates SUCCESS.
1847 : */
1848 : return SUCCESS;
1849 0 : case DID_SOFT_ERROR:
1850 : /*
1851 : * when the low level driver returns did_soft_error,
1852 : * it is responsible for keeping an internal retry counter
1853 : * in order to avoid endless loops (db)
1854 : */
1855 0 : goto maybe_retry;
1856 0 : case DID_IMM_RETRY:
1857 0 : return NEEDS_RETRY;
1858 :
1859 0 : case DID_REQUEUE:
1860 0 : return ADD_TO_MLQUEUE;
1861 0 : case DID_TRANSPORT_DISRUPTED:
1862 : /*
1863 : * LLD/transport was disrupted during processing of the IO.
1864 : * The transport class is now blocked/blocking,
1865 : * and the transport will decide what to do with the IO
1866 : * based on its timers and recovery capablilities if
1867 : * there are enough retries.
1868 : */
1869 0 : goto maybe_retry;
1870 : case DID_TRANSPORT_FAILFAST:
1871 : /*
1872 : * The transport decided to failfast the IO (most likely
1873 : * the fast io fail tmo fired), so send IO directly upwards.
1874 : */
1875 : return SUCCESS;
1876 : case DID_TRANSPORT_MARGINAL:
1877 : /*
1878 : * caller has decided not to do retries on
1879 : * abort success, so send IO directly upwards
1880 : */
1881 : return SUCCESS;
1882 0 : case DID_ERROR:
1883 0 : if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
1884 0 : status_byte(scmd->result) == RESERVATION_CONFLICT)
1885 : /*
1886 : * execute reservation conflict processing code
1887 : * lower down
1888 : */
1889 : break;
1890 0 : fallthrough;
1891 : case DID_BUS_BUSY:
1892 : case DID_PARITY:
1893 0 : goto maybe_retry;
1894 0 : case DID_TIME_OUT:
1895 : /*
1896 : * when we scan the bus, we get timeout messages for
1897 : * these commands if there is no device available.
1898 : * other hosts report did_no_connect for the same thing.
1899 : */
1900 0 : if ((scmd->cmnd[0] == TEST_UNIT_READY ||
1901 : scmd->cmnd[0] == INQUIRY)) {
1902 : return SUCCESS;
1903 : } else {
1904 0 : return FAILED;
1905 : }
1906 : case DID_RESET:
1907 : return SUCCESS;
1908 0 : default:
1909 0 : return FAILED;
1910 : }
1911 :
1912 : /*
1913 : * next, check the message byte.
1914 : */
1915 0 : if (msg_byte(scmd->result) != COMMAND_COMPLETE)
1916 : return FAILED;
1917 :
1918 : /*
1919 : * check the status byte to see if this indicates anything special.
1920 : */
1921 0 : switch (status_byte(scmd->result)) {
1922 0 : case QUEUE_FULL:
1923 0 : scsi_handle_queue_full(scmd->device);
1924 : /*
1925 : * the case of trying to send too many commands to a
1926 : * tagged queueing device.
1927 : */
1928 : fallthrough;
1929 : case BUSY:
1930 : /*
1931 : * device can't talk to us at the moment. Should only
1932 : * occur (SAM-3) when the task queue is empty, so will cause
1933 : * the empty queue handling to trigger a stall in the
1934 : * device.
1935 : */
1936 : return ADD_TO_MLQUEUE;
1937 0 : case GOOD:
1938 0 : if (scmd->cmnd[0] == REPORT_LUNS)
1939 0 : scmd->device->sdev_target->expecting_lun_change = 0;
1940 0 : scsi_handle_queue_ramp_up(scmd->device);
1941 : fallthrough;
1942 : case COMMAND_TERMINATED:
1943 : return SUCCESS;
1944 0 : case TASK_ABORTED:
1945 0 : goto maybe_retry;
1946 0 : case CHECK_CONDITION:
1947 0 : rtn = scsi_check_sense(scmd);
1948 0 : if (rtn == NEEDS_RETRY)
1949 0 : goto maybe_retry;
1950 : /* if rtn == FAILED, we have no sense information;
1951 : * returning FAILED will wake the error handler thread
1952 : * to collect the sense and redo the decide
1953 : * disposition */
1954 : return rtn;
1955 : case CONDITION_GOOD:
1956 : case INTERMEDIATE_GOOD:
1957 : case INTERMEDIATE_C_GOOD:
1958 : case ACA_ACTIVE:
1959 : /*
1960 : * who knows? FIXME(eric)
1961 : */
1962 : return SUCCESS;
1963 :
1964 0 : case RESERVATION_CONFLICT:
1965 0 : sdev_printk(KERN_INFO, scmd->device,
1966 : "reservation conflict\n");
1967 0 : set_host_byte(scmd, DID_NEXUS_FAILURE);
1968 0 : return SUCCESS; /* causes immediate i/o error */
1969 0 : default:
1970 0 : return FAILED;
1971 : }
1972 : return FAILED;
1973 :
1974 0 : maybe_retry:
1975 :
1976 : /* we requeue for retry because the error was retryable, and
1977 : * the request was not marked fast fail. Note that above,
1978 : * even if the request is marked fast fail, we still requeue
1979 : * for queue congestion conditions (QUEUE_FULL or BUSY) */
1980 0 : if (scsi_cmd_retry_allowed(scmd) && !scsi_noretry_cmd(scmd)) {
1981 : return NEEDS_RETRY;
1982 : } else {
1983 : /*
1984 : * no more retries - report this one back to upper level.
1985 : */
1986 0 : return SUCCESS;
1987 : }
1988 : }
1989 :
1990 0 : static void eh_lock_door_done(struct request *req, blk_status_t status)
1991 : {
1992 0 : blk_put_request(req);
1993 0 : }
1994 :
1995 : /**
1996 : * scsi_eh_lock_door - Prevent medium removal for the specified device
1997 : * @sdev: SCSI device to prevent medium removal
1998 : *
1999 : * Locking:
2000 : * We must be called from process context.
2001 : *
2002 : * Notes:
2003 : * We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the
2004 : * head of the devices request queue, and continue.
2005 : */
2006 0 : static void scsi_eh_lock_door(struct scsi_device *sdev)
2007 : {
2008 0 : struct request *req;
2009 0 : struct scsi_request *rq;
2010 :
2011 0 : req = blk_get_request(sdev->request_queue, REQ_OP_SCSI_IN, 0);
2012 0 : if (IS_ERR(req))
2013 : return;
2014 0 : rq = scsi_req(req);
2015 :
2016 0 : rq->cmd[0] = ALLOW_MEDIUM_REMOVAL;
2017 0 : rq->cmd[1] = 0;
2018 0 : rq->cmd[2] = 0;
2019 0 : rq->cmd[3] = 0;
2020 0 : rq->cmd[4] = SCSI_REMOVAL_PREVENT;
2021 0 : rq->cmd[5] = 0;
2022 0 : rq->cmd_len = COMMAND_SIZE(rq->cmd[0]);
2023 :
2024 0 : req->rq_flags |= RQF_QUIET;
2025 0 : req->timeout = 10 * HZ;
2026 0 : rq->retries = 5;
2027 :
2028 0 : blk_execute_rq_nowait(NULL, req, 1, eh_lock_door_done);
2029 : }
2030 :
2031 : /**
2032 : * scsi_restart_operations - restart io operations to the specified host.
2033 : * @shost: Host we are restarting.
2034 : *
2035 : * Notes:
2036 : * When we entered the error handler, we blocked all further i/o to
2037 : * this device. we need to 'reverse' this process.
2038 : */
2039 0 : static void scsi_restart_operations(struct Scsi_Host *shost)
2040 : {
2041 0 : struct scsi_device *sdev;
2042 0 : unsigned long flags;
2043 :
2044 : /*
2045 : * If the door was locked, we need to insert a door lock request
2046 : * onto the head of the SCSI request queue for the device. There
2047 : * is no point trying to lock the door of an off-line device.
2048 : */
2049 0 : shost_for_each_device(sdev, shost) {
2050 0 : if (scsi_device_online(sdev) && sdev->was_reset && sdev->locked) {
2051 0 : scsi_eh_lock_door(sdev);
2052 0 : sdev->was_reset = 0;
2053 : }
2054 : }
2055 :
2056 : /*
2057 : * next free up anything directly waiting upon the host. this
2058 : * will be requests for character device operations, and also for
2059 : * ioctls to queued block devices.
2060 : */
2061 0 : SCSI_LOG_ERROR_RECOVERY(3,
2062 0 : shost_printk(KERN_INFO, shost, "waking up host to restart\n"));
2063 :
2064 0 : spin_lock_irqsave(shost->host_lock, flags);
2065 0 : if (scsi_host_set_state(shost, SHOST_RUNNING))
2066 0 : if (scsi_host_set_state(shost, SHOST_CANCEL))
2067 0 : BUG_ON(scsi_host_set_state(shost, SHOST_DEL));
2068 0 : spin_unlock_irqrestore(shost->host_lock, flags);
2069 :
2070 0 : wake_up(&shost->host_wait);
2071 :
2072 : /*
2073 : * finally we need to re-initiate requests that may be pending. we will
2074 : * have had everything blocked while error handling is taking place, and
2075 : * now that error recovery is done, we will need to ensure that these
2076 : * requests are started.
2077 : */
2078 0 : scsi_run_host_queues(shost);
2079 :
2080 : /*
2081 : * if eh is active and host_eh_scheduled is pending we need to re-run
2082 : * recovery. we do this check after scsi_run_host_queues() to allow
2083 : * everything pent up since the last eh run a chance to make forward
2084 : * progress before we sync again. Either we'll immediately re-run
2085 : * recovery or scsi_device_unbusy() will wake us again when these
2086 : * pending commands complete.
2087 : */
2088 0 : spin_lock_irqsave(shost->host_lock, flags);
2089 0 : if (shost->host_eh_scheduled)
2090 0 : if (scsi_host_set_state(shost, SHOST_RECOVERY))
2091 0 : WARN_ON(scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY));
2092 0 : spin_unlock_irqrestore(shost->host_lock, flags);
2093 0 : }
2094 :
2095 : /**
2096 : * scsi_eh_ready_devs - check device ready state and recover if not.
2097 : * @shost: host to be recovered.
2098 : * @work_q: &list_head for pending commands.
2099 : * @done_q: &list_head for processed commands.
2100 : */
2101 0 : void scsi_eh_ready_devs(struct Scsi_Host *shost,
2102 : struct list_head *work_q,
2103 : struct list_head *done_q)
2104 : {
2105 0 : if (!scsi_eh_stu(shost, work_q, done_q))
2106 0 : if (!scsi_eh_bus_device_reset(shost, work_q, done_q))
2107 0 : if (!scsi_eh_target_reset(shost, work_q, done_q))
2108 0 : if (!scsi_eh_bus_reset(shost, work_q, done_q))
2109 0 : if (!scsi_eh_host_reset(shost, work_q, done_q))
2110 0 : scsi_eh_offline_sdevs(work_q,
2111 : done_q);
2112 0 : }
2113 : EXPORT_SYMBOL_GPL(scsi_eh_ready_devs);
2114 :
2115 : /**
2116 : * scsi_eh_flush_done_q - finish processed commands or retry them.
2117 : * @done_q: list_head of processed commands.
2118 : */
2119 0 : void scsi_eh_flush_done_q(struct list_head *done_q)
2120 : {
2121 0 : struct scsi_cmnd *scmd, *next;
2122 :
2123 0 : list_for_each_entry_safe(scmd, next, done_q, eh_entry) {
2124 0 : list_del_init(&scmd->eh_entry);
2125 0 : if (scsi_device_online(scmd->device) &&
2126 0 : !scsi_noretry_cmd(scmd) && scsi_cmd_retry_allowed(scmd) &&
2127 0 : scsi_eh_should_retry_cmd(scmd)) {
2128 0 : SCSI_LOG_ERROR_RECOVERY(3,
2129 : scmd_printk(KERN_INFO, scmd,
2130 : "%s: flush retry cmd\n",
2131 0 : current->comm));
2132 0 : scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY);
2133 : } else {
2134 : /*
2135 : * If just we got sense for the device (called
2136 : * scsi_eh_get_sense), scmd->result is already
2137 : * set, do not set DRIVER_TIMEOUT.
2138 : */
2139 0 : if (!scmd->result)
2140 0 : scmd->result |= (DRIVER_TIMEOUT << 24);
2141 0 : SCSI_LOG_ERROR_RECOVERY(3,
2142 : scmd_printk(KERN_INFO, scmd,
2143 : "%s: flush finish cmd\n",
2144 0 : current->comm));
2145 0 : scsi_finish_command(scmd);
2146 : }
2147 : }
2148 0 : }
2149 : EXPORT_SYMBOL(scsi_eh_flush_done_q);
2150 :
2151 : /**
2152 : * scsi_unjam_host - Attempt to fix a host which has a cmd that failed.
2153 : * @shost: Host to unjam.
2154 : *
2155 : * Notes:
2156 : * When we come in here, we *know* that all commands on the bus have
2157 : * either completed, failed or timed out. we also know that no further
2158 : * commands are being sent to the host, so things are relatively quiet
2159 : * and we have freedom to fiddle with things as we wish.
2160 : *
2161 : * This is only the *default* implementation. it is possible for
2162 : * individual drivers to supply their own version of this function, and
2163 : * if the maintainer wishes to do this, it is strongly suggested that
2164 : * this function be taken as a template and modified. this function
2165 : * was designed to correctly handle problems for about 95% of the
2166 : * different cases out there, and it should always provide at least a
2167 : * reasonable amount of error recovery.
2168 : *
2169 : * Any command marked 'failed' or 'timeout' must eventually have
2170 : * scsi_finish_cmd() called for it. we do all of the retry stuff
2171 : * here, so when we restart the host after we return it should have an
2172 : * empty queue.
2173 : */
2174 0 : static void scsi_unjam_host(struct Scsi_Host *shost)
2175 : {
2176 0 : unsigned long flags;
2177 0 : LIST_HEAD(eh_work_q);
2178 0 : LIST_HEAD(eh_done_q);
2179 :
2180 0 : spin_lock_irqsave(shost->host_lock, flags);
2181 0 : list_splice_init(&shost->eh_cmd_q, &eh_work_q);
2182 0 : spin_unlock_irqrestore(shost->host_lock, flags);
2183 :
2184 0 : SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(shost, &eh_work_q));
2185 :
2186 0 : if (!scsi_eh_get_sense(&eh_work_q, &eh_done_q))
2187 0 : scsi_eh_ready_devs(shost, &eh_work_q, &eh_done_q);
2188 :
2189 0 : spin_lock_irqsave(shost->host_lock, flags);
2190 0 : if (shost->eh_deadline != -1)
2191 0 : shost->last_reset = 0;
2192 0 : spin_unlock_irqrestore(shost->host_lock, flags);
2193 0 : scsi_eh_flush_done_q(&eh_done_q);
2194 0 : }
2195 :
2196 : /**
2197 : * scsi_error_handler - SCSI error handler thread
2198 : * @data: Host for which we are running.
2199 : *
2200 : * Notes:
2201 : * This is the main error handling loop. This is run as a kernel thread
2202 : * for every SCSI host and handles all error handling activity.
2203 : */
2204 0 : int scsi_error_handler(void *data)
2205 : {
2206 0 : struct Scsi_Host *shost = data;
2207 :
2208 : /*
2209 : * We use TASK_INTERRUPTIBLE so that the thread is not
2210 : * counted against the load average as a running process.
2211 : * We never actually get interrupted because kthread_run
2212 : * disables signal delivery for the created thread.
2213 : */
2214 0 : while (true) {
2215 : /*
2216 : * The sequence in kthread_stop() sets the stop flag first
2217 : * then wakes the process. To avoid missed wakeups, the task
2218 : * should always be in a non running state before the stop
2219 : * flag is checked
2220 : */
2221 0 : set_current_state(TASK_INTERRUPTIBLE);
2222 0 : if (kthread_should_stop())
2223 : break;
2224 :
2225 0 : if ((shost->host_failed == 0 && shost->host_eh_scheduled == 0) ||
2226 0 : shost->host_failed != scsi_host_busy(shost)) {
2227 0 : SCSI_LOG_ERROR_RECOVERY(1,
2228 : shost_printk(KERN_INFO, shost,
2229 : "scsi_eh_%d: sleeping\n",
2230 0 : shost->host_no));
2231 0 : schedule();
2232 0 : continue;
2233 : }
2234 :
2235 0 : __set_current_state(TASK_RUNNING);
2236 0 : SCSI_LOG_ERROR_RECOVERY(1,
2237 : shost_printk(KERN_INFO, shost,
2238 : "scsi_eh_%d: waking up %d/%d/%d\n",
2239 : shost->host_no, shost->host_eh_scheduled,
2240 : shost->host_failed,
2241 0 : scsi_host_busy(shost)));
2242 :
2243 : /*
2244 : * We have a host that is failing for some reason. Figure out
2245 : * what we need to do to get it up and online again (if we can).
2246 : * If we fail, we end up taking the thing offline.
2247 : */
2248 0 : if (!shost->eh_noresume && scsi_autopm_get_host(shost) != 0) {
2249 : SCSI_LOG_ERROR_RECOVERY(1,
2250 : shost_printk(KERN_ERR, shost,
2251 : "scsi_eh_%d: unable to autoresume\n",
2252 : shost->host_no));
2253 : continue;
2254 : }
2255 :
2256 0 : if (shost->transportt->eh_strategy_handler)
2257 0 : shost->transportt->eh_strategy_handler(shost);
2258 : else
2259 0 : scsi_unjam_host(shost);
2260 :
2261 : /* All scmds have been handled */
2262 0 : shost->host_failed = 0;
2263 :
2264 : /*
2265 : * Note - if the above fails completely, the action is to take
2266 : * individual devices offline and flush the queue of any
2267 : * outstanding requests that may have been pending. When we
2268 : * restart, we restart any I/O to any other devices on the bus
2269 : * which are still online.
2270 : */
2271 0 : scsi_restart_operations(shost);
2272 0 : if (!shost->eh_noresume)
2273 0 : scsi_autopm_put_host(shost);
2274 : }
2275 0 : __set_current_state(TASK_RUNNING);
2276 :
2277 0 : SCSI_LOG_ERROR_RECOVERY(1,
2278 : shost_printk(KERN_INFO, shost,
2279 : "Error handler scsi_eh_%d exiting\n",
2280 0 : shost->host_no));
2281 0 : shost->ehandler = NULL;
2282 0 : return 0;
2283 : }
2284 :
2285 : /*
2286 : * Function: scsi_report_bus_reset()
2287 : *
2288 : * Purpose: Utility function used by low-level drivers to report that
2289 : * they have observed a bus reset on the bus being handled.
2290 : *
2291 : * Arguments: shost - Host in question
2292 : * channel - channel on which reset was observed.
2293 : *
2294 : * Returns: Nothing
2295 : *
2296 : * Lock status: Host lock must be held.
2297 : *
2298 : * Notes: This only needs to be called if the reset is one which
2299 : * originates from an unknown location. Resets originated
2300 : * by the mid-level itself don't need to call this, but there
2301 : * should be no harm.
2302 : *
2303 : * The main purpose of this is to make sure that a CHECK_CONDITION
2304 : * is properly treated.
2305 : */
2306 0 : void scsi_report_bus_reset(struct Scsi_Host *shost, int channel)
2307 : {
2308 0 : struct scsi_device *sdev;
2309 :
2310 0 : __shost_for_each_device(sdev, shost) {
2311 0 : if (channel == sdev_channel(sdev))
2312 0 : __scsi_report_device_reset(sdev, NULL);
2313 : }
2314 0 : }
2315 : EXPORT_SYMBOL(scsi_report_bus_reset);
2316 :
2317 : /*
2318 : * Function: scsi_report_device_reset()
2319 : *
2320 : * Purpose: Utility function used by low-level drivers to report that
2321 : * they have observed a device reset on the device being handled.
2322 : *
2323 : * Arguments: shost - Host in question
2324 : * channel - channel on which reset was observed
2325 : * target - target on which reset was observed
2326 : *
2327 : * Returns: Nothing
2328 : *
2329 : * Lock status: Host lock must be held
2330 : *
2331 : * Notes: This only needs to be called if the reset is one which
2332 : * originates from an unknown location. Resets originated
2333 : * by the mid-level itself don't need to call this, but there
2334 : * should be no harm.
2335 : *
2336 : * The main purpose of this is to make sure that a CHECK_CONDITION
2337 : * is properly treated.
2338 : */
2339 0 : void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
2340 : {
2341 0 : struct scsi_device *sdev;
2342 :
2343 0 : __shost_for_each_device(sdev, shost) {
2344 0 : if (channel == sdev_channel(sdev) &&
2345 0 : target == sdev_id(sdev))
2346 0 : __scsi_report_device_reset(sdev, NULL);
2347 : }
2348 0 : }
2349 : EXPORT_SYMBOL(scsi_report_device_reset);
2350 :
2351 : static void
2352 0 : scsi_reset_provider_done_command(struct scsi_cmnd *scmd)
2353 : {
2354 0 : }
2355 :
2356 : /**
2357 : * scsi_ioctl_reset: explicitly reset a host/bus/target/device
2358 : * @dev: scsi_device to operate on
2359 : * @arg: reset type (see sg.h)
2360 : */
2361 : int
2362 0 : scsi_ioctl_reset(struct scsi_device *dev, int __user *arg)
2363 : {
2364 0 : struct scsi_cmnd *scmd;
2365 0 : struct Scsi_Host *shost = dev->host;
2366 0 : struct request *rq;
2367 0 : unsigned long flags;
2368 0 : int error = 0, rtn, val;
2369 :
2370 0 : if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
2371 0 : return -EACCES;
2372 :
2373 0 : error = get_user(val, arg);
2374 0 : if (error)
2375 : return error;
2376 :
2377 0 : if (scsi_autopm_get_host(shost) < 0)
2378 : return -EIO;
2379 :
2380 0 : error = -EIO;
2381 0 : rq = kzalloc(sizeof(struct request) + sizeof(struct scsi_cmnd) +
2382 0 : shost->hostt->cmd_size, GFP_KERNEL);
2383 0 : if (!rq)
2384 0 : goto out_put_autopm_host;
2385 0 : blk_rq_init(NULL, rq);
2386 :
2387 0 : scmd = (struct scsi_cmnd *)(rq + 1);
2388 0 : scsi_init_command(dev, scmd);
2389 0 : scmd->request = rq;
2390 0 : scmd->cmnd = scsi_req(rq)->cmd;
2391 :
2392 0 : scmd->scsi_done = scsi_reset_provider_done_command;
2393 0 : memset(&scmd->sdb, 0, sizeof(scmd->sdb));
2394 :
2395 0 : scmd->cmd_len = 0;
2396 :
2397 0 : scmd->sc_data_direction = DMA_BIDIRECTIONAL;
2398 :
2399 0 : spin_lock_irqsave(shost->host_lock, flags);
2400 0 : shost->tmf_in_progress = 1;
2401 0 : spin_unlock_irqrestore(shost->host_lock, flags);
2402 :
2403 0 : switch (val & ~SG_SCSI_RESET_NO_ESCALATE) {
2404 : case SG_SCSI_RESET_NOTHING:
2405 : rtn = SUCCESS;
2406 : break;
2407 0 : case SG_SCSI_RESET_DEVICE:
2408 0 : rtn = scsi_try_bus_device_reset(scmd);
2409 0 : if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE))
2410 : break;
2411 0 : fallthrough;
2412 : case SG_SCSI_RESET_TARGET:
2413 0 : rtn = scsi_try_target_reset(scmd);
2414 0 : if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE))
2415 : break;
2416 0 : fallthrough;
2417 : case SG_SCSI_RESET_BUS:
2418 0 : rtn = scsi_try_bus_reset(scmd);
2419 0 : if (rtn == SUCCESS || (val & SG_SCSI_RESET_NO_ESCALATE))
2420 : break;
2421 0 : fallthrough;
2422 : case SG_SCSI_RESET_HOST:
2423 0 : rtn = scsi_try_host_reset(scmd);
2424 0 : if (rtn == SUCCESS)
2425 : break;
2426 : fallthrough;
2427 : default:
2428 : rtn = FAILED;
2429 : break;
2430 : }
2431 :
2432 0 : error = (rtn == SUCCESS) ? 0 : -EIO;
2433 :
2434 0 : spin_lock_irqsave(shost->host_lock, flags);
2435 0 : shost->tmf_in_progress = 0;
2436 0 : spin_unlock_irqrestore(shost->host_lock, flags);
2437 :
2438 : /*
2439 : * be sure to wake up anyone who was sleeping or had their queue
2440 : * suspended while we performed the TMF.
2441 : */
2442 0 : SCSI_LOG_ERROR_RECOVERY(3,
2443 : shost_printk(KERN_INFO, shost,
2444 0 : "waking up host to restart after TMF\n"));
2445 :
2446 0 : wake_up(&shost->host_wait);
2447 0 : scsi_run_host_queues(shost);
2448 :
2449 0 : kfree(rq);
2450 :
2451 : out_put_autopm_host:
2452 0 : scsi_autopm_put_host(shost);
2453 : return error;
2454 : }
2455 :
2456 0 : bool scsi_command_normalize_sense(const struct scsi_cmnd *cmd,
2457 : struct scsi_sense_hdr *sshdr)
2458 : {
2459 0 : return scsi_normalize_sense(cmd->sense_buffer,
2460 : SCSI_SENSE_BUFFERSIZE, sshdr);
2461 : }
2462 : EXPORT_SYMBOL(scsi_command_normalize_sense);
2463 :
2464 : /**
2465 : * scsi_get_sense_info_fld - get information field from sense data (either fixed or descriptor format)
2466 : * @sense_buffer: byte array of sense data
2467 : * @sb_len: number of valid bytes in sense_buffer
2468 : * @info_out: pointer to 64 integer where 8 or 4 byte information
2469 : * field will be placed if found.
2470 : *
2471 : * Return value:
2472 : * true if information field found, false if not found.
2473 : */
2474 0 : bool scsi_get_sense_info_fld(const u8 *sense_buffer, int sb_len,
2475 : u64 *info_out)
2476 : {
2477 0 : const u8 * ucp;
2478 :
2479 0 : if (sb_len < 7)
2480 : return false;
2481 0 : switch (sense_buffer[0] & 0x7f) {
2482 0 : case 0x70:
2483 : case 0x71:
2484 0 : if (sense_buffer[0] & 0x80) {
2485 0 : *info_out = get_unaligned_be32(&sense_buffer[3]);
2486 0 : return true;
2487 : }
2488 : return false;
2489 0 : case 0x72:
2490 : case 0x73:
2491 0 : ucp = scsi_sense_desc_find(sense_buffer, sb_len,
2492 : 0 /* info desc */);
2493 0 : if (ucp && (0xa == ucp[1])) {
2494 0 : *info_out = get_unaligned_be64(&ucp[4]);
2495 0 : return true;
2496 : }
2497 : return false;
2498 : default:
2499 : return false;
2500 : }
2501 : }
2502 : EXPORT_SYMBOL(scsi_get_sense_info_fld);
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