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