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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * scsi_error.c Copyright (C) 1997 Eric Youngdale
3 *
4 * SCSI error/timeout handling
5 * Initial versions: Eric Youngdale. Based upon conversations with
6 * Leonard Zubkoff and David Miller at Linux Expo,
7 * ideas originating from all over the place.
8 *
9 * Restructured scsi_unjam_host and associated functions.
10 * September 04, 2002 Mike Anderson (andmike@us.ibm.com)
11 *
12 * Forward port of Russell King's (rmk@arm.linux.org.uk) changes and
13 * minor cleanups.
14 * September 30, 2002 Mike Anderson (andmike@us.ibm.com)
15 */
16
17#include <linux/module.h>
18#include <linux/sched.h>
19#include <linux/timer.h>
20#include <linux/string.h>
21#include <linux/slab.h>
22#include <linux/kernel.h>
Christoph Hellwigc5478de2005-09-06 14:04:26 +020023#include <linux/kthread.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/interrupt.h>
25#include <linux/blkdev.h>
26#include <linux/delay.h>
27
28#include <scsi/scsi.h>
29#include <scsi/scsi_dbg.h>
30#include <scsi/scsi_device.h>
31#include <scsi/scsi_eh.h>
32#include <scsi/scsi_host.h>
33#include <scsi/scsi_ioctl.h>
34#include <scsi/scsi_request.h>
35
36#include "scsi_priv.h"
37#include "scsi_logging.h"
38
39#define SENSE_TIMEOUT (10*HZ)
40#define START_UNIT_TIMEOUT (30*HZ)
41
42/*
43 * These should *probably* be handled by the host itself.
44 * Since it is allowed to sleep, it probably should.
45 */
46#define BUS_RESET_SETTLE_TIME (10)
47#define HOST_RESET_SETTLE_TIME (10)
48
49/* called with shost->host_lock held */
50void scsi_eh_wakeup(struct Scsi_Host *shost)
51{
52 if (shost->host_busy == shost->host_failed) {
James Bottomley3ed7a472005-09-19 09:50:04 -050053 wake_up_process(shost->ehandler);
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 SCSI_LOG_ERROR_RECOVERY(5,
55 printk("Waking error handler thread\n"));
56 }
57}
58
59/**
60 * scsi_eh_scmd_add - add scsi cmd to error handling.
61 * @scmd: scmd to run eh on.
62 * @eh_flag: optional SCSI_EH flag.
63 *
64 * Return value:
65 * 0 on failure.
66 **/
67int scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag)
68{
69 struct Scsi_Host *shost = scmd->device->host;
70 unsigned long flags;
James Bottomley939647e2005-09-18 15:05:20 -050071 int ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
James Bottomley3ed7a472005-09-19 09:50:04 -050073 if (!shost->ehandler)
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 return 0;
75
76 spin_lock_irqsave(shost->host_lock, flags);
James Bottomley939647e2005-09-18 15:05:20 -050077 if (scsi_host_set_state(shost, SHOST_RECOVERY))
78 if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY))
79 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
James Bottomley939647e2005-09-18 15:05:20 -050081 ret = 1;
Christoph Hellwig3111b0d2005-06-19 13:43:26 +020082 scmd->eh_eflags |= eh_flag;
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 shost->host_failed++;
85 scsi_eh_wakeup(shost);
James Bottomley939647e2005-09-18 15:05:20 -050086 out_unlock:
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 spin_unlock_irqrestore(shost->host_lock, flags);
James Bottomley939647e2005-09-18 15:05:20 -050088 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -070089}
90
91/**
92 * scsi_add_timer - Start timeout timer for a single scsi command.
93 * @scmd: scsi command that is about to start running.
94 * @timeout: amount of time to allow this command to run.
95 * @complete: timeout function to call if timer isn't canceled.
96 *
97 * Notes:
98 * This should be turned into an inline function. Each scsi command
99 * has its own timer, and as it is added to the queue, we set up the
100 * timer. When the command completes, we cancel the timer.
101 **/
102void scsi_add_timer(struct scsi_cmnd *scmd, int timeout,
103 void (*complete)(struct scsi_cmnd *))
104{
105
106 /*
107 * If the clock was already running for this command, then
108 * first delete the timer. The timer handling code gets rather
109 * confused if we don't do this.
110 */
111 if (scmd->eh_timeout.function)
112 del_timer(&scmd->eh_timeout);
113
114 scmd->eh_timeout.data = (unsigned long)scmd;
115 scmd->eh_timeout.expires = jiffies + timeout;
116 scmd->eh_timeout.function = (void (*)(unsigned long)) complete;
117
118 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p, time:"
119 " %d, (%p)\n", __FUNCTION__,
120 scmd, timeout, complete));
121
122 add_timer(&scmd->eh_timeout);
123}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124
125/**
126 * scsi_delete_timer - Delete/cancel timer for a given function.
127 * @scmd: Cmd that we are canceling timer for
128 *
129 * Notes:
130 * This should be turned into an inline function.
131 *
132 * Return value:
133 * 1 if we were able to detach the timer. 0 if we blew it, and the
134 * timer function has already started to run.
135 **/
136int scsi_delete_timer(struct scsi_cmnd *scmd)
137{
138 int rtn;
139
140 rtn = del_timer(&scmd->eh_timeout);
141
142 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p,"
143 " rtn: %d\n", __FUNCTION__,
144 scmd, rtn));
145
146 scmd->eh_timeout.data = (unsigned long)NULL;
147 scmd->eh_timeout.function = NULL;
148
149 return rtn;
150}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151
152/**
153 * scsi_times_out - Timeout function for normal scsi commands.
154 * @scmd: Cmd that is timing out.
155 *
156 * Notes:
157 * We do not need to lock this. There is the potential for a race
158 * only in that the normal completion handling might run, but if the
159 * normal completion function determines that the timer has already
160 * fired, then it mustn't do anything.
161 **/
162void scsi_times_out(struct scsi_cmnd *scmd)
163{
164 scsi_log_completion(scmd, TIMEOUT_ERROR);
165
166 if (scmd->device->host->hostt->eh_timed_out)
167 switch (scmd->device->host->hostt->eh_timed_out(scmd)) {
168 case EH_HANDLED:
169 __scsi_done(scmd);
170 return;
171 case EH_RESET_TIMER:
172 /* This allows a single retry even of a command
173 * with allowed == 0 */
174 if (scmd->retries++ > scmd->allowed)
175 break;
176 scsi_add_timer(scmd, scmd->timeout_per_command,
177 scsi_times_out);
178 return;
179 case EH_NOT_HANDLED:
180 break;
181 }
182
183 if (unlikely(!scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD))) {
James Bottomley939647e2005-09-18 15:05:20 -0500184 scmd->result |= DID_TIME_OUT << 16;
185 __scsi_done(scmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 }
187}
188
189/**
190 * scsi_block_when_processing_errors - Prevent cmds from being queued.
191 * @sdev: Device on which we are performing recovery.
192 *
193 * Description:
194 * We block until the host is out of error recovery, and then check to
195 * see whether the host or the device is offline.
196 *
197 * Return value:
198 * 0 when dev was taken offline by error recovery. 1 OK to proceed.
199 **/
200int scsi_block_when_processing_errors(struct scsi_device *sdev)
201{
202 int online;
203
James Bottomley939647e2005-09-18 15:05:20 -0500204 wait_event(sdev->host->host_wait, !scsi_host_in_recovery(sdev->host));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205
206 online = scsi_device_online(sdev);
207
208 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: rtn: %d\n", __FUNCTION__,
209 online));
210
211 return online;
212}
213EXPORT_SYMBOL(scsi_block_when_processing_errors);
214
215#ifdef CONFIG_SCSI_LOGGING
216/**
217 * scsi_eh_prt_fail_stats - Log info on failures.
218 * @shost: scsi host being recovered.
219 * @work_q: Queue of scsi cmds to process.
220 **/
221static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost,
222 struct list_head *work_q)
223{
224 struct scsi_cmnd *scmd;
225 struct scsi_device *sdev;
226 int total_failures = 0;
227 int cmd_failed = 0;
228 int cmd_cancel = 0;
229 int devices_failed = 0;
230
231 shost_for_each_device(sdev, shost) {
232 list_for_each_entry(scmd, work_q, eh_entry) {
233 if (scmd->device == sdev) {
234 ++total_failures;
Christoph Hellwig3111b0d2005-06-19 13:43:26 +0200235 if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 ++cmd_cancel;
237 else
238 ++cmd_failed;
239 }
240 }
241
242 if (cmd_cancel || cmd_failed) {
243 SCSI_LOG_ERROR_RECOVERY(3,
James Bottomley9ccfc752005-10-02 11:45:08 -0500244 sdev_printk(KERN_INFO, sdev,
245 "%s: cmds failed: %d, cancel: %d\n",
246 __FUNCTION__, cmd_failed,
247 cmd_cancel));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 cmd_cancel = 0;
249 cmd_failed = 0;
250 ++devices_failed;
251 }
252 }
253
254 SCSI_LOG_ERROR_RECOVERY(2, printk("Total of %d commands on %d"
255 " devices require eh work\n",
256 total_failures, devices_failed));
257}
258#endif
259
260/**
261 * scsi_check_sense - Examine scsi cmd sense
262 * @scmd: Cmd to have sense checked.
263 *
264 * Return value:
265 * SUCCESS or FAILED or NEEDS_RETRY
266 *
267 * Notes:
268 * When a deferred error is detected the current command has
269 * not been executed and needs retrying.
270 **/
271static int scsi_check_sense(struct scsi_cmnd *scmd)
272{
273 struct scsi_sense_hdr sshdr;
274
275 if (! scsi_command_normalize_sense(scmd, &sshdr))
276 return FAILED; /* no valid sense data */
277
278 if (scsi_sense_is_deferred(&sshdr))
279 return NEEDS_RETRY;
280
281 /*
282 * Previous logic looked for FILEMARK, EOM or ILI which are
283 * mainly associated with tapes and returned SUCCESS.
284 */
285 if (sshdr.response_code == 0x70) {
286 /* fixed format */
287 if (scmd->sense_buffer[2] & 0xe0)
288 return SUCCESS;
289 } else {
290 /*
291 * descriptor format: look for "stream commands sense data
292 * descriptor" (see SSC-3). Assume single sense data
293 * descriptor. Ignore ILI from SBC-2 READ LONG and WRITE LONG.
294 */
295 if ((sshdr.additional_length > 3) &&
296 (scmd->sense_buffer[8] == 0x4) &&
297 (scmd->sense_buffer[11] & 0xe0))
298 return SUCCESS;
299 }
300
301 switch (sshdr.sense_key) {
302 case NO_SENSE:
303 return SUCCESS;
304 case RECOVERED_ERROR:
305 return /* soft_error */ SUCCESS;
306
307 case ABORTED_COMMAND:
308 return NEEDS_RETRY;
309 case NOT_READY:
310 case UNIT_ATTENTION:
311 /*
312 * if we are expecting a cc/ua because of a bus reset that we
313 * performed, treat this just as a retry. otherwise this is
314 * information that we should pass up to the upper-level driver
315 * so that we can deal with it there.
316 */
317 if (scmd->device->expecting_cc_ua) {
318 scmd->device->expecting_cc_ua = 0;
319 return NEEDS_RETRY;
320 }
321 /*
322 * if the device is in the process of becoming ready, we
323 * should retry.
324 */
325 if ((sshdr.asc == 0x04) && (sshdr.ascq == 0x01))
326 return NEEDS_RETRY;
327 /*
328 * if the device is not started, we need to wake
329 * the error handler to start the motor
330 */
331 if (scmd->device->allow_restart &&
332 (sshdr.asc == 0x04) && (sshdr.ascq == 0x02))
333 return FAILED;
334 return SUCCESS;
335
336 /* these three are not supported */
337 case COPY_ABORTED:
338 case VOLUME_OVERFLOW:
339 case MISCOMPARE:
340 return SUCCESS;
341
342 case MEDIUM_ERROR:
343 return NEEDS_RETRY;
344
345 case HARDWARE_ERROR:
346 if (scmd->device->retry_hwerror)
347 return NEEDS_RETRY;
348 else
349 return SUCCESS;
350
351 case ILLEGAL_REQUEST:
352 case BLANK_CHECK:
353 case DATA_PROTECT:
354 default:
355 return SUCCESS;
356 }
357}
358
359/**
360 * scsi_eh_completed_normally - Disposition a eh cmd on return from LLD.
361 * @scmd: SCSI cmd to examine.
362 *
363 * Notes:
364 * This is *only* called when we are examining the status of commands
365 * queued during error recovery. the main difference here is that we
366 * don't allow for the possibility of retries here, and we are a lot
367 * more restrictive about what we consider acceptable.
368 **/
369static int scsi_eh_completed_normally(struct scsi_cmnd *scmd)
370{
371 /*
372 * first check the host byte, to see if there is anything in there
373 * that would indicate what we need to do.
374 */
375 if (host_byte(scmd->result) == DID_RESET) {
376 /*
377 * rats. we are already in the error handler, so we now
378 * get to try and figure out what to do next. if the sense
379 * is valid, we have a pretty good idea of what to do.
380 * if not, we mark it as FAILED.
381 */
382 return scsi_check_sense(scmd);
383 }
384 if (host_byte(scmd->result) != DID_OK)
385 return FAILED;
386
387 /*
388 * next, check the message byte.
389 */
390 if (msg_byte(scmd->result) != COMMAND_COMPLETE)
391 return FAILED;
392
393 /*
394 * now, check the status byte to see if this indicates
395 * anything special.
396 */
397 switch (status_byte(scmd->result)) {
398 case GOOD:
399 case COMMAND_TERMINATED:
400 return SUCCESS;
401 case CHECK_CONDITION:
402 return scsi_check_sense(scmd);
403 case CONDITION_GOOD:
404 case INTERMEDIATE_GOOD:
405 case INTERMEDIATE_C_GOOD:
406 /*
407 * who knows? FIXME(eric)
408 */
409 return SUCCESS;
410 case BUSY:
411 case QUEUE_FULL:
412 case RESERVATION_CONFLICT:
413 default:
414 return FAILED;
415 }
416 return FAILED;
417}
418
419/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 * scsi_eh_done - Completion function for error handling.
421 * @scmd: Cmd that is done.
422 **/
423static void scsi_eh_done(struct scsi_cmnd *scmd)
424{
Michael Reed85631672005-12-07 21:46:27 -0600425 struct completion *eh_action;
426
Christoph Hellwig7dfdc9a2005-10-31 18:49:52 +0100427 SCSI_LOG_ERROR_RECOVERY(3,
428 printk("%s scmd: %p result: %x\n",
429 __FUNCTION__, scmd, scmd->result));
Michael Reed85631672005-12-07 21:46:27 -0600430
431 eh_action = scmd->device->host->eh_action;
432 if (eh_action)
433 complete(eh_action);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434}
435
436/**
437 * scsi_send_eh_cmnd - send a cmd to a device as part of error recovery.
438 * @scmd: SCSI Cmd to send.
439 * @timeout: Timeout for cmd.
440 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 * Return value:
442 * SUCCESS or FAILED or NEEDS_RETRY
443 **/
444static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, int timeout)
445{
f59114b2005-04-17 15:00:23 -0500446 struct scsi_device *sdev = scmd->device;
447 struct Scsi_Host *shost = sdev->host;
Christoph Hellwig7dfdc9a2005-10-31 18:49:52 +0100448 DECLARE_COMPLETION(done);
449 unsigned long timeleft;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450 unsigned long flags;
Christoph Hellwig7dfdc9a2005-10-31 18:49:52 +0100451 int rtn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452
f59114b2005-04-17 15:00:23 -0500453 if (sdev->scsi_level <= SCSI_2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) |
f59114b2005-04-17 15:00:23 -0500455 (sdev->lun << 5 & 0xe0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456
Christoph Hellwig7dfdc9a2005-10-31 18:49:52 +0100457 shost->eh_action = &done;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 scmd->request->rq_status = RQ_SCSI_BUSY;
459
f59114b2005-04-17 15:00:23 -0500460 spin_lock_irqsave(shost->host_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 scsi_log_send(scmd);
f59114b2005-04-17 15:00:23 -0500462 shost->hostt->queuecommand(scmd, scsi_eh_done);
463 spin_unlock_irqrestore(shost->host_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464
Christoph Hellwig7dfdc9a2005-10-31 18:49:52 +0100465 timeleft = wait_for_completion_timeout(&done, timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466
Christoph Hellwig7dfdc9a2005-10-31 18:49:52 +0100467 scmd->request->rq_status = RQ_SCSI_DONE;
f59114b2005-04-17 15:00:23 -0500468 shost->eh_action = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469
Christoph Hellwig7dfdc9a2005-10-31 18:49:52 +0100470 scsi_log_completion(scmd, SUCCESS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471
Christoph Hellwig7dfdc9a2005-10-31 18:49:52 +0100472 SCSI_LOG_ERROR_RECOVERY(3,
473 printk("%s: scmd: %p, timeleft: %ld\n",
474 __FUNCTION__, scmd, timeleft));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475
476 /*
Christoph Hellwig7dfdc9a2005-10-31 18:49:52 +0100477 * If there is time left scsi_eh_done got called, and we will
478 * examine the actual status codes to see whether the command
479 * actually did complete normally, else tell the host to forget
480 * about this command.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 */
Christoph Hellwig7dfdc9a2005-10-31 18:49:52 +0100482 if (timeleft) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483 rtn = scsi_eh_completed_normally(scmd);
484 SCSI_LOG_ERROR_RECOVERY(3,
485 printk("%s: scsi_eh_completed_normally %x\n",
486 __FUNCTION__, rtn));
Christoph Hellwig7dfdc9a2005-10-31 18:49:52 +0100487
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 switch (rtn) {
489 case SUCCESS:
490 case NEEDS_RETRY:
491 case FAILED:
492 break;
493 default:
494 rtn = FAILED;
495 break;
496 }
Christoph Hellwig7dfdc9a2005-10-31 18:49:52 +0100497 } else {
498 /*
499 * FIXME(eric) - we are not tracking whether we could
500 * abort a timed out command or not. not sure how
501 * we should treat them differently anyways.
502 */
503 if (shost->hostt->eh_abort_handler)
504 shost->hostt->eh_abort_handler(scmd);
505 rtn = FAILED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 }
507
508 return rtn;
509}
510
511/**
512 * scsi_request_sense - Request sense data from a particular target.
513 * @scmd: SCSI cmd for request sense.
514 *
515 * Notes:
516 * Some hosts automatically obtain this information, others require
517 * that we obtain it on our own. This function will *not* return until
518 * the command either times out, or it completes.
519 **/
520static int scsi_request_sense(struct scsi_cmnd *scmd)
521{
522 static unsigned char generic_sense[6] =
523 {REQUEST_SENSE, 0, 0, 0, 252, 0};
524 unsigned char *scsi_result;
525 int saved_result;
526 int rtn;
527
528 memcpy(scmd->cmnd, generic_sense, sizeof(generic_sense));
529
Al Virobc861202005-04-24 12:28:34 -0700530 scsi_result = kmalloc(252, GFP_ATOMIC | ((scmd->device->host->hostt->unchecked_isa_dma) ? __GFP_DMA : 0));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531
532
533 if (unlikely(!scsi_result)) {
534 printk(KERN_ERR "%s: cannot allocate scsi_result.\n",
535 __FUNCTION__);
536 return FAILED;
537 }
538
539 /*
540 * zero the sense buffer. some host adapters automatically always
541 * request sense, so it is not a good idea that
542 * scmd->request_buffer and scmd->sense_buffer point to the same
543 * address (db). 0 is not a valid sense code.
544 */
545 memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
546 memset(scsi_result, 0, 252);
547
548 saved_result = scmd->result;
549 scmd->request_buffer = scsi_result;
550 scmd->request_bufflen = 252;
551 scmd->use_sg = 0;
552 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
553 scmd->sc_data_direction = DMA_FROM_DEVICE;
554 scmd->underflow = 0;
555
556 rtn = scsi_send_eh_cmnd(scmd, SENSE_TIMEOUT);
557
558 /* last chance to have valid sense data */
559 if(!SCSI_SENSE_VALID(scmd)) {
560 memcpy(scmd->sense_buffer, scmd->request_buffer,
561 sizeof(scmd->sense_buffer));
562 }
563
564 kfree(scsi_result);
565
566 /*
567 * when we eventually call scsi_finish, we really wish to complete
568 * the original request, so let's restore the original data. (db)
569 */
570 scsi_setup_cmd_retry(scmd);
571 scmd->result = saved_result;
572 return rtn;
573}
574
575/**
576 * scsi_eh_finish_cmd - Handle a cmd that eh is finished with.
577 * @scmd: Original SCSI cmd that eh has finished.
578 * @done_q: Queue for processed commands.
579 *
580 * Notes:
581 * We don't want to use the normal command completion while we are are
582 * still handling errors - it may cause other commands to be queued,
583 * and that would disturb what we are doing. thus we really want to
584 * keep a list of pending commands for final completion, and once we
585 * are ready to leave error handling we handle completion for real.
586 **/
587static void scsi_eh_finish_cmd(struct scsi_cmnd *scmd,
588 struct list_head *done_q)
589{
590 scmd->device->host->host_failed--;
Christoph Hellwig3111b0d2005-06-19 13:43:26 +0200591 scmd->eh_eflags = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592
593 /*
594 * set this back so that the upper level can correctly free up
595 * things.
596 */
597 scsi_setup_cmd_retry(scmd);
598 list_move_tail(&scmd->eh_entry, done_q);
599}
600
601/**
602 * scsi_eh_get_sense - Get device sense data.
603 * @work_q: Queue of commands to process.
604 * @done_q: Queue of proccessed commands..
605 *
606 * Description:
607 * See if we need to request sense information. if so, then get it
608 * now, so we have a better idea of what to do.
609 *
610 * Notes:
611 * This has the unfortunate side effect that if a shost adapter does
612 * not automatically request sense information, that we end up shutting
613 * it down before we request it.
614 *
615 * All drivers should request sense information internally these days,
616 * so for now all I have to say is tough noogies if you end up in here.
617 *
618 * XXX: Long term this code should go away, but that needs an audit of
619 * all LLDDs first.
620 **/
621static int scsi_eh_get_sense(struct list_head *work_q,
622 struct list_head *done_q)
623{
Christoph Hellwig937abeaa2005-06-19 13:43:56 +0200624 struct scsi_cmnd *scmd, *next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625 int rtn;
626
Christoph Hellwig937abeaa2005-06-19 13:43:56 +0200627 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
Christoph Hellwig3111b0d2005-06-19 13:43:26 +0200628 if ((scmd->eh_eflags & SCSI_EH_CANCEL_CMD) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 SCSI_SENSE_VALID(scmd))
630 continue;
631
Jeff Garzik3bf743e2005-10-24 18:04:06 -0400632 SCSI_LOG_ERROR_RECOVERY(2, scmd_printk(KERN_INFO, scmd,
633 "%s: requesting sense\n",
634 current->comm));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 rtn = scsi_request_sense(scmd);
636 if (rtn != SUCCESS)
637 continue;
638
639 SCSI_LOG_ERROR_RECOVERY(3, printk("sense requested for %p"
640 " result %x\n", scmd,
641 scmd->result));
642 SCSI_LOG_ERROR_RECOVERY(3, scsi_print_sense("bh", scmd));
643
644 rtn = scsi_decide_disposition(scmd);
645
646 /*
647 * if the result was normal, then just pass it along to the
648 * upper level.
649 */
650 if (rtn == SUCCESS)
651 /* we don't want this command reissued, just
652 * finished with the sense data, so set
653 * retries to the max allowed to ensure it
654 * won't get reissued */
655 scmd->retries = scmd->allowed;
656 else if (rtn != NEEDS_RETRY)
657 continue;
658
659 scsi_eh_finish_cmd(scmd, done_q);
660 }
661
662 return list_empty(work_q);
663}
664
665/**
666 * scsi_try_to_abort_cmd - Ask host to abort a running command.
667 * @scmd: SCSI cmd to abort from Lower Level.
668 *
669 * Notes:
670 * This function will not return until the user's completion function
671 * has been called. there is no timeout on this operation. if the
672 * author of the low-level driver wishes this operation to be timed,
673 * they can provide this facility themselves. helper functions in
674 * scsi_error.c can be supplied to make this easier to do.
675 **/
676static int scsi_try_to_abort_cmd(struct scsi_cmnd *scmd)
677{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 if (!scmd->device->host->hostt->eh_abort_handler)
Jeff Garzik 8fa728a2005-05-28 07:54:40 -0400679 return FAILED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680
681 /*
682 * scsi_done was called just after the command timed out and before
683 * we had a chance to process it. (db)
684 */
685 if (scmd->serial_number == 0)
686 return SUCCESS;
Jeff Garzik 8fa728a2005-05-28 07:54:40 -0400687 return scmd->device->host->hostt->eh_abort_handler(scmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688}
689
690/**
691 * scsi_eh_tur - Send TUR to device.
692 * @scmd: Scsi cmd to send TUR
693 *
694 * Return value:
695 * 0 - Device is ready. 1 - Device NOT ready.
696 **/
697static int scsi_eh_tur(struct scsi_cmnd *scmd)
698{
699 static unsigned char tur_command[6] = {TEST_UNIT_READY, 0, 0, 0, 0, 0};
700 int retry_cnt = 1, rtn;
Patrick Mansfield 793698c2005-05-16 17:42:15 -0700701 int saved_result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702
703retry_tur:
704 memcpy(scmd->cmnd, tur_command, sizeof(tur_command));
705
706 /*
707 * zero the sense buffer. the scsi spec mandates that any
708 * untransferred sense data should be interpreted as being zero.
709 */
710 memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
711
Patrick Mansfield 793698c2005-05-16 17:42:15 -0700712 saved_result = scmd->result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 scmd->request_buffer = NULL;
714 scmd->request_bufflen = 0;
715 scmd->use_sg = 0;
716 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
717 scmd->underflow = 0;
718 scmd->sc_data_direction = DMA_NONE;
719
720 rtn = scsi_send_eh_cmnd(scmd, SENSE_TIMEOUT);
721
722 /*
723 * when we eventually call scsi_finish, we really wish to complete
724 * the original request, so let's restore the original data. (db)
725 */
726 scsi_setup_cmd_retry(scmd);
Patrick Mansfield 793698c2005-05-16 17:42:15 -0700727 scmd->result = saved_result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728
729 /*
730 * hey, we are done. let's look to see what happened.
731 */
732 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n",
733 __FUNCTION__, scmd, rtn));
734 if (rtn == SUCCESS)
735 return 0;
Alan Sterne47373e2005-03-30 15:05:45 -0500736 else if (rtn == NEEDS_RETRY) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737 if (retry_cnt--)
738 goto retry_tur;
Alan Sterne47373e2005-03-30 15:05:45 -0500739 return 0;
740 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741 return 1;
742}
743
744/**
745 * scsi_eh_abort_cmds - abort canceled commands.
746 * @shost: scsi host being recovered.
747 * @eh_done_q: list_head for processed commands.
748 *
749 * Decription:
750 * Try and see whether or not it makes sense to try and abort the
751 * running command. this only works out to be the case if we have one
752 * command that has timed out. if the command simply failed, it makes
753 * no sense to try and abort the command, since as far as the shost
754 * adapter is concerned, it isn't running.
755 **/
756static int scsi_eh_abort_cmds(struct list_head *work_q,
757 struct list_head *done_q)
758{
Christoph Hellwig937abeaa2005-06-19 13:43:56 +0200759 struct scsi_cmnd *scmd, *next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760 int rtn;
761
Christoph Hellwig937abeaa2005-06-19 13:43:56 +0200762 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
Christoph Hellwig3111b0d2005-06-19 13:43:26 +0200763 if (!(scmd->eh_eflags & SCSI_EH_CANCEL_CMD))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764 continue;
765 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting cmd:"
766 "0x%p\n", current->comm,
767 scmd));
768 rtn = scsi_try_to_abort_cmd(scmd);
769 if (rtn == SUCCESS) {
Christoph Hellwig3111b0d2005-06-19 13:43:26 +0200770 scmd->eh_eflags &= ~SCSI_EH_CANCEL_CMD;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771 if (!scsi_device_online(scmd->device) ||
772 !scsi_eh_tur(scmd)) {
773 scsi_eh_finish_cmd(scmd, done_q);
774 }
775
776 } else
777 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting"
778 " cmd failed:"
779 "0x%p\n",
780 current->comm,
781 scmd));
782 }
783
784 return list_empty(work_q);
785}
786
787/**
788 * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev
789 * @scmd: SCSI cmd used to send BDR
790 *
791 * Notes:
792 * There is no timeout for this operation. if this operation is
793 * unreliable for a given host, then the host itself needs to put a
794 * timer on it, and set the host back to a consistent state prior to
795 * returning.
796 **/
797static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd)
798{
Jeff Garzik 94d0e7b82005-05-28 07:55:48 -0400799 int rtn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800
801 if (!scmd->device->host->hostt->eh_device_reset_handler)
Jeff Garzik 94d0e7b82005-05-28 07:55:48 -0400802 return FAILED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 rtn = scmd->device->host->hostt->eh_device_reset_handler(scmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 if (rtn == SUCCESS) {
806 scmd->device->was_reset = 1;
807 scmd->device->expecting_cc_ua = 1;
808 }
809
810 return rtn;
811}
812
813/**
814 * scsi_eh_try_stu - Send START_UNIT to device.
815 * @scmd: Scsi cmd to send START_UNIT
816 *
817 * Return value:
818 * 0 - Device is ready. 1 - Device NOT ready.
819 **/
820static int scsi_eh_try_stu(struct scsi_cmnd *scmd)
821{
822 static unsigned char stu_command[6] = {START_STOP, 0, 0, 0, 1, 0};
823 int rtn;
Patrick Mansfield 793698c2005-05-16 17:42:15 -0700824 int saved_result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825
826 if (!scmd->device->allow_restart)
827 return 1;
828
829 memcpy(scmd->cmnd, stu_command, sizeof(stu_command));
830
831 /*
832 * zero the sense buffer. the scsi spec mandates that any
833 * untransferred sense data should be interpreted as being zero.
834 */
835 memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
836
Patrick Mansfield 793698c2005-05-16 17:42:15 -0700837 saved_result = scmd->result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838 scmd->request_buffer = NULL;
839 scmd->request_bufflen = 0;
840 scmd->use_sg = 0;
841 scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
842 scmd->underflow = 0;
843 scmd->sc_data_direction = DMA_NONE;
844
845 rtn = scsi_send_eh_cmnd(scmd, START_UNIT_TIMEOUT);
846
847 /*
848 * when we eventually call scsi_finish, we really wish to complete
849 * the original request, so let's restore the original data. (db)
850 */
851 scsi_setup_cmd_retry(scmd);
Patrick Mansfield 793698c2005-05-16 17:42:15 -0700852 scmd->result = saved_result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853
854 /*
855 * hey, we are done. let's look to see what happened.
856 */
857 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n",
858 __FUNCTION__, scmd, rtn));
859 if (rtn == SUCCESS)
860 return 0;
861 return 1;
862}
863
864 /**
865 * scsi_eh_stu - send START_UNIT if needed
866 * @shost: scsi host being recovered.
867 * @eh_done_q: list_head for processed commands.
868 *
869 * Notes:
870 * If commands are failing due to not ready, initializing command required,
871 * try revalidating the device, which will end up sending a start unit.
872 **/
873static int scsi_eh_stu(struct Scsi_Host *shost,
874 struct list_head *work_q,
875 struct list_head *done_q)
876{
Christoph Hellwig937abeaa2005-06-19 13:43:56 +0200877 struct scsi_cmnd *scmd, *stu_scmd, *next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 struct scsi_device *sdev;
879
880 shost_for_each_device(sdev, shost) {
881 stu_scmd = NULL;
882 list_for_each_entry(scmd, work_q, eh_entry)
883 if (scmd->device == sdev && SCSI_SENSE_VALID(scmd) &&
884 scsi_check_sense(scmd) == FAILED ) {
885 stu_scmd = scmd;
886 break;
887 }
888
889 if (!stu_scmd)
890 continue;
891
892 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending START_UNIT to sdev:"
893 " 0x%p\n", current->comm, sdev));
894
895 if (!scsi_eh_try_stu(stu_scmd)) {
896 if (!scsi_device_online(sdev) ||
897 !scsi_eh_tur(stu_scmd)) {
Christoph Hellwig937abeaa2005-06-19 13:43:56 +0200898 list_for_each_entry_safe(scmd, next,
899 work_q, eh_entry) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900 if (scmd->device == sdev)
901 scsi_eh_finish_cmd(scmd, done_q);
902 }
903 }
904 } else {
905 SCSI_LOG_ERROR_RECOVERY(3,
906 printk("%s: START_UNIT failed to sdev:"
907 " 0x%p\n", current->comm, sdev));
908 }
909 }
910
911 return list_empty(work_q);
912}
913
914
915/**
916 * scsi_eh_bus_device_reset - send bdr if needed
917 * @shost: scsi host being recovered.
918 * @eh_done_q: list_head for processed commands.
919 *
920 * Notes:
921 * Try a bus device reset. still, look to see whether we have multiple
922 * devices that are jammed or not - if we have multiple devices, it
923 * makes no sense to try bus_device_reset - we really would need to try
924 * a bus_reset instead.
925 **/
926static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
927 struct list_head *work_q,
928 struct list_head *done_q)
929{
Christoph Hellwig937abeaa2005-06-19 13:43:56 +0200930 struct scsi_cmnd *scmd, *bdr_scmd, *next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931 struct scsi_device *sdev;
932 int rtn;
933
934 shost_for_each_device(sdev, shost) {
935 bdr_scmd = NULL;
936 list_for_each_entry(scmd, work_q, eh_entry)
937 if (scmd->device == sdev) {
938 bdr_scmd = scmd;
939 break;
940 }
941
942 if (!bdr_scmd)
943 continue;
944
945 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BDR sdev:"
946 " 0x%p\n", current->comm,
947 sdev));
948 rtn = scsi_try_bus_device_reset(bdr_scmd);
949 if (rtn == SUCCESS) {
950 if (!scsi_device_online(sdev) ||
951 !scsi_eh_tur(bdr_scmd)) {
Christoph Hellwig937abeaa2005-06-19 13:43:56 +0200952 list_for_each_entry_safe(scmd, next,
953 work_q, eh_entry) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954 if (scmd->device == sdev)
955 scsi_eh_finish_cmd(scmd,
956 done_q);
957 }
958 }
959 } else {
960 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BDR"
961 " failed sdev:"
962 "0x%p\n",
963 current->comm,
964 sdev));
965 }
966 }
967
968 return list_empty(work_q);
969}
970
971/**
972 * scsi_try_bus_reset - ask host to perform a bus reset
973 * @scmd: SCSI cmd to send bus reset.
974 **/
975static int scsi_try_bus_reset(struct scsi_cmnd *scmd)
976{
977 unsigned long flags;
978 int rtn;
979
980 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Bus RST\n",
981 __FUNCTION__));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982
983 if (!scmd->device->host->hostt->eh_bus_reset_handler)
984 return FAILED;
985
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986 rtn = scmd->device->host->hostt->eh_bus_reset_handler(scmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987
988 if (rtn == SUCCESS) {
989 if (!scmd->device->host->hostt->skip_settle_delay)
990 ssleep(BUS_RESET_SETTLE_TIME);
991 spin_lock_irqsave(scmd->device->host->host_lock, flags);
Jeff Garzik422c0d62005-10-24 18:05:09 -0400992 scsi_report_bus_reset(scmd->device->host,
993 scmd_channel(scmd));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994 spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
995 }
996
997 return rtn;
998}
999
1000/**
1001 * scsi_try_host_reset - ask host adapter to reset itself
1002 * @scmd: SCSI cmd to send hsot reset.
1003 **/
1004static int scsi_try_host_reset(struct scsi_cmnd *scmd)
1005{
1006 unsigned long flags;
1007 int rtn;
1008
1009 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Host RST\n",
1010 __FUNCTION__));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001011
1012 if (!scmd->device->host->hostt->eh_host_reset_handler)
1013 return FAILED;
1014
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015 rtn = scmd->device->host->hostt->eh_host_reset_handler(scmd);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016
1017 if (rtn == SUCCESS) {
1018 if (!scmd->device->host->hostt->skip_settle_delay)
1019 ssleep(HOST_RESET_SETTLE_TIME);
1020 spin_lock_irqsave(scmd->device->host->host_lock, flags);
Jeff Garzik422c0d62005-10-24 18:05:09 -04001021 scsi_report_bus_reset(scmd->device->host,
1022 scmd_channel(scmd));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001023 spin_unlock_irqrestore(scmd->device->host->host_lock, flags);
1024 }
1025
1026 return rtn;
1027}
1028
1029/**
1030 * scsi_eh_bus_reset - send a bus reset
1031 * @shost: scsi host being recovered.
1032 * @eh_done_q: list_head for processed commands.
1033 **/
1034static int scsi_eh_bus_reset(struct Scsi_Host *shost,
1035 struct list_head *work_q,
1036 struct list_head *done_q)
1037{
Christoph Hellwig937abeaa2005-06-19 13:43:56 +02001038 struct scsi_cmnd *scmd, *chan_scmd, *next;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001039 unsigned int channel;
1040 int rtn;
1041
1042 /*
1043 * we really want to loop over the various channels, and do this on
1044 * a channel by channel basis. we should also check to see if any
1045 * of the failed commands are on soft_reset devices, and if so, skip
1046 * the reset.
1047 */
1048
1049 for (channel = 0; channel <= shost->max_channel; channel++) {
1050 chan_scmd = NULL;
1051 list_for_each_entry(scmd, work_q, eh_entry) {
Jeff Garzik422c0d62005-10-24 18:05:09 -04001052 if (channel == scmd_channel(scmd)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001053 chan_scmd = scmd;
1054 break;
1055 /*
1056 * FIXME add back in some support for
1057 * soft_reset devices.
1058 */
1059 }
1060 }
1061
1062 if (!chan_scmd)
1063 continue;
1064 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BRST chan:"
1065 " %d\n", current->comm,
1066 channel));
1067 rtn = scsi_try_bus_reset(chan_scmd);
1068 if (rtn == SUCCESS) {
Christoph Hellwig937abeaa2005-06-19 13:43:56 +02001069 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
Jeff Garzik422c0d62005-10-24 18:05:09 -04001070 if (channel == scmd_channel(scmd))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001071 if (!scsi_device_online(scmd->device) ||
1072 !scsi_eh_tur(scmd))
1073 scsi_eh_finish_cmd(scmd,
1074 done_q);
1075 }
1076 } else {
1077 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BRST"
1078 " failed chan: %d\n",
1079 current->comm,
1080 channel));
1081 }
1082 }
1083 return list_empty(work_q);
1084}
1085
1086/**
1087 * scsi_eh_host_reset - send a host reset
1088 * @work_q: list_head for processed commands.
1089 * @done_q: list_head for processed commands.
1090 **/
1091static int scsi_eh_host_reset(struct list_head *work_q,
1092 struct list_head *done_q)
1093{
Christoph Hellwig937abeaa2005-06-19 13:43:56 +02001094 struct scsi_cmnd *scmd, *next;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001095 int rtn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001096
1097 if (!list_empty(work_q)) {
1098 scmd = list_entry(work_q->next,
1099 struct scsi_cmnd, eh_entry);
1100
1101 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending HRST\n"
1102 , current->comm));
1103
1104 rtn = scsi_try_host_reset(scmd);
1105 if (rtn == SUCCESS) {
Christoph Hellwig937abeaa2005-06-19 13:43:56 +02001106 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001107 if (!scsi_device_online(scmd->device) ||
1108 (!scsi_eh_try_stu(scmd) && !scsi_eh_tur(scmd)) ||
1109 !scsi_eh_tur(scmd))
1110 scsi_eh_finish_cmd(scmd, done_q);
1111 }
1112 } else {
1113 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: HRST"
1114 " failed\n",
1115 current->comm));
1116 }
1117 }
1118 return list_empty(work_q);
1119}
1120
1121/**
1122 * scsi_eh_offline_sdevs - offline scsi devices that fail to recover
1123 * @work_q: list_head for processed commands.
1124 * @done_q: list_head for processed commands.
1125 *
1126 **/
1127static void scsi_eh_offline_sdevs(struct list_head *work_q,
1128 struct list_head *done_q)
1129{
Christoph Hellwig937abeaa2005-06-19 13:43:56 +02001130 struct scsi_cmnd *scmd, *next;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001131
Christoph Hellwig937abeaa2005-06-19 13:43:56 +02001132 list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
James Bottomley9ccfc752005-10-02 11:45:08 -05001133 sdev_printk(KERN_INFO, scmd->device,
1134 "scsi: Device offlined - not"
1135 " ready after error recovery\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001136 scsi_device_set_state(scmd->device, SDEV_OFFLINE);
Christoph Hellwig3111b0d2005-06-19 13:43:26 +02001137 if (scmd->eh_eflags & SCSI_EH_CANCEL_CMD) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138 /*
1139 * FIXME: Handle lost cmds.
1140 */
1141 }
1142 scsi_eh_finish_cmd(scmd, done_q);
1143 }
1144 return;
1145}
1146
1147/**
1148 * scsi_decide_disposition - Disposition a cmd on return from LLD.
1149 * @scmd: SCSI cmd to examine.
1150 *
1151 * Notes:
1152 * This is *only* called when we are examining the status after sending
1153 * out the actual data command. any commands that are queued for error
1154 * recovery (e.g. test_unit_ready) do *not* come through here.
1155 *
1156 * When this routine returns failed, it means the error handler thread
1157 * is woken. In cases where the error code indicates an error that
1158 * doesn't require the error handler read (i.e. we don't need to
1159 * abort/reset), this function should return SUCCESS.
1160 **/
1161int scsi_decide_disposition(struct scsi_cmnd *scmd)
1162{
1163 int rtn;
1164
1165 /*
1166 * if the device is offline, then we clearly just pass the result back
1167 * up to the top level.
1168 */
1169 if (!scsi_device_online(scmd->device)) {
1170 SCSI_LOG_ERROR_RECOVERY(5, printk("%s: device offline - report"
1171 " as SUCCESS\n",
1172 __FUNCTION__));
1173 return SUCCESS;
1174 }
1175
1176 /*
1177 * first check the host byte, to see if there is anything in there
1178 * that would indicate what we need to do.
1179 */
1180 switch (host_byte(scmd->result)) {
1181 case DID_PASSTHROUGH:
1182 /*
1183 * no matter what, pass this through to the upper layer.
1184 * nuke this special code so that it looks like we are saying
1185 * did_ok.
1186 */
1187 scmd->result &= 0xff00ffff;
1188 return SUCCESS;
1189 case DID_OK:
1190 /*
1191 * looks good. drop through, and check the next byte.
1192 */
1193 break;
1194 case DID_NO_CONNECT:
1195 case DID_BAD_TARGET:
1196 case DID_ABORT:
1197 /*
1198 * note - this means that we just report the status back
1199 * to the top level driver, not that we actually think
1200 * that it indicates SUCCESS.
1201 */
1202 return SUCCESS;
1203 /*
1204 * when the low level driver returns did_soft_error,
1205 * it is responsible for keeping an internal retry counter
1206 * in order to avoid endless loops (db)
1207 *
1208 * actually this is a bug in this function here. we should
1209 * be mindful of the maximum number of retries specified
1210 * and not get stuck in a loop.
1211 */
1212 case DID_SOFT_ERROR:
1213 goto maybe_retry;
1214 case DID_IMM_RETRY:
1215 return NEEDS_RETRY;
1216
bf341912005-04-12 17:49:09 -05001217 case DID_REQUEUE:
1218 return ADD_TO_MLQUEUE;
1219
Linus Torvalds1da177e2005-04-16 15:20:36 -07001220 case DID_ERROR:
1221 if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
1222 status_byte(scmd->result) == RESERVATION_CONFLICT)
1223 /*
1224 * execute reservation conflict processing code
1225 * lower down
1226 */
1227 break;
1228 /* fallthrough */
1229
1230 case DID_BUS_BUSY:
1231 case DID_PARITY:
1232 goto maybe_retry;
1233 case DID_TIME_OUT:
1234 /*
1235 * when we scan the bus, we get timeout messages for
1236 * these commands if there is no device available.
1237 * other hosts report did_no_connect for the same thing.
1238 */
1239 if ((scmd->cmnd[0] == TEST_UNIT_READY ||
1240 scmd->cmnd[0] == INQUIRY)) {
1241 return SUCCESS;
1242 } else {
1243 return FAILED;
1244 }
1245 case DID_RESET:
1246 return SUCCESS;
1247 default:
1248 return FAILED;
1249 }
1250
1251 /*
1252 * next, check the message byte.
1253 */
1254 if (msg_byte(scmd->result) != COMMAND_COMPLETE)
1255 return FAILED;
1256
1257 /*
1258 * check the status byte to see if this indicates anything special.
1259 */
1260 switch (status_byte(scmd->result)) {
1261 case QUEUE_FULL:
1262 /*
1263 * the case of trying to send too many commands to a
1264 * tagged queueing device.
1265 */
1266 case BUSY:
1267 /*
1268 * device can't talk to us at the moment. Should only
1269 * occur (SAM-3) when the task queue is empty, so will cause
1270 * the empty queue handling to trigger a stall in the
1271 * device.
1272 */
1273 return ADD_TO_MLQUEUE;
1274 case GOOD:
1275 case COMMAND_TERMINATED:
1276 case TASK_ABORTED:
1277 return SUCCESS;
1278 case CHECK_CONDITION:
1279 rtn = scsi_check_sense(scmd);
1280 if (rtn == NEEDS_RETRY)
1281 goto maybe_retry;
1282 /* if rtn == FAILED, we have no sense information;
1283 * returning FAILED will wake the error handler thread
1284 * to collect the sense and redo the decide
1285 * disposition */
1286 return rtn;
1287 case CONDITION_GOOD:
1288 case INTERMEDIATE_GOOD:
1289 case INTERMEDIATE_C_GOOD:
1290 case ACA_ACTIVE:
1291 /*
1292 * who knows? FIXME(eric)
1293 */
1294 return SUCCESS;
1295
1296 case RESERVATION_CONFLICT:
James Bottomley9ccfc752005-10-02 11:45:08 -05001297 sdev_printk(KERN_INFO, scmd->device,
1298 "reservation conflict\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001299 return SUCCESS; /* causes immediate i/o error */
1300 default:
1301 return FAILED;
1302 }
1303 return FAILED;
1304
1305 maybe_retry:
1306
1307 /* we requeue for retry because the error was retryable, and
1308 * the request was not marked fast fail. Note that above,
1309 * even if the request is marked fast fail, we still requeue
1310 * for queue congestion conditions (QUEUE_FULL or BUSY) */
1311 if ((++scmd->retries) < scmd->allowed
1312 && !blk_noretry_request(scmd->request)) {
1313 return NEEDS_RETRY;
1314 } else {
1315 /*
1316 * no more retries - report this one back to upper level.
1317 */
1318 return SUCCESS;
1319 }
1320}
1321
1322/**
Linus Torvalds1da177e2005-04-16 15:20:36 -07001323 * scsi_eh_lock_door - Prevent medium removal for the specified device
1324 * @sdev: SCSI device to prevent medium removal
1325 *
1326 * Locking:
1327 * We must be called from process context; scsi_allocate_request()
1328 * may sleep.
1329 *
1330 * Notes:
1331 * We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the
1332 * head of the devices request queue, and continue.
1333 *
1334 * Bugs:
1335 * scsi_allocate_request() may sleep waiting for existing requests to
1336 * be processed. However, since we haven't kicked off any request
1337 * processing for this host, this may deadlock.
1338 *
1339 * If scsi_allocate_request() fails for what ever reason, we
1340 * completely forget to lock the door.
1341 **/
1342static void scsi_eh_lock_door(struct scsi_device *sdev)
1343{
Mike Christie6e68af62005-11-11 05:30:27 -06001344 unsigned char cmnd[MAX_COMMAND_SIZE];
Linus Torvalds1da177e2005-04-16 15:20:36 -07001345
Mike Christie6e68af62005-11-11 05:30:27 -06001346 cmnd[0] = ALLOW_MEDIUM_REMOVAL;
1347 cmnd[1] = 0;
1348 cmnd[2] = 0;
1349 cmnd[3] = 0;
1350 cmnd[4] = SCSI_REMOVAL_PREVENT;
1351 cmnd[5] = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001352
brking@us.ibm.combb1d1072006-01-23 15:03:22 -06001353 scsi_execute_async(sdev, cmnd, 6, DMA_NONE, NULL, 0, 0, 10 * HZ,
Mike Christie6e68af62005-11-11 05:30:27 -06001354 5, NULL, NULL, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001355}
1356
1357
1358/**
1359 * scsi_restart_operations - restart io operations to the specified host.
1360 * @shost: Host we are restarting.
1361 *
1362 * Notes:
1363 * When we entered the error handler, we blocked all further i/o to
1364 * this device. we need to 'reverse' this process.
1365 **/
1366static void scsi_restart_operations(struct Scsi_Host *shost)
1367{
1368 struct scsi_device *sdev;
James Bottomley939647e2005-09-18 15:05:20 -05001369 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001370
1371 /*
1372 * If the door was locked, we need to insert a door lock request
1373 * onto the head of the SCSI request queue for the device. There
1374 * is no point trying to lock the door of an off-line device.
1375 */
1376 shost_for_each_device(sdev, shost) {
1377 if (scsi_device_online(sdev) && sdev->locked)
1378 scsi_eh_lock_door(sdev);
1379 }
1380
1381 /*
1382 * next free up anything directly waiting upon the host. this
1383 * will be requests for character device operations, and also for
1384 * ioctls to queued block devices.
1385 */
1386 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: waking up host to restart\n",
1387 __FUNCTION__));
1388
James Bottomley939647e2005-09-18 15:05:20 -05001389 spin_lock_irqsave(shost->host_lock, flags);
1390 if (scsi_host_set_state(shost, SHOST_RUNNING))
1391 if (scsi_host_set_state(shost, SHOST_CANCEL))
1392 BUG_ON(scsi_host_set_state(shost, SHOST_DEL));
1393 spin_unlock_irqrestore(shost->host_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001394
1395 wake_up(&shost->host_wait);
1396
1397 /*
1398 * finally we need to re-initiate requests that may be pending. we will
1399 * have had everything blocked while error handling is taking place, and
1400 * now that error recovery is done, we will need to ensure that these
1401 * requests are started.
1402 */
1403 scsi_run_host_queues(shost);
1404}
1405
1406/**
1407 * scsi_eh_ready_devs - check device ready state and recover if not.
1408 * @shost: host to be recovered.
1409 * @eh_done_q: list_head for processed commands.
1410 *
1411 **/
1412static void scsi_eh_ready_devs(struct Scsi_Host *shost,
1413 struct list_head *work_q,
1414 struct list_head *done_q)
1415{
1416 if (!scsi_eh_stu(shost, work_q, done_q))
1417 if (!scsi_eh_bus_device_reset(shost, work_q, done_q))
1418 if (!scsi_eh_bus_reset(shost, work_q, done_q))
1419 if (!scsi_eh_host_reset(work_q, done_q))
1420 scsi_eh_offline_sdevs(work_q, done_q);
1421}
1422
1423/**
1424 * scsi_eh_flush_done_q - finish processed commands or retry them.
1425 * @done_q: list_head of processed commands.
1426 *
1427 **/
1428static void scsi_eh_flush_done_q(struct list_head *done_q)
1429{
Christoph Hellwig937abeaa2005-06-19 13:43:56 +02001430 struct scsi_cmnd *scmd, *next;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001431
Christoph Hellwig937abeaa2005-06-19 13:43:56 +02001432 list_for_each_entry_safe(scmd, next, done_q, eh_entry) {
1433 list_del_init(&scmd->eh_entry);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001434 if (scsi_device_online(scmd->device) &&
1435 !blk_noretry_request(scmd->request) &&
1436 (++scmd->retries < scmd->allowed)) {
1437 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush"
1438 " retry cmd: %p\n",
1439 current->comm,
1440 scmd));
1441 scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY);
1442 } else {
Patrick Mansfield 793698c2005-05-16 17:42:15 -07001443 /*
1444 * If just we got sense for the device (called
1445 * scsi_eh_get_sense), scmd->result is already
1446 * set, do not set DRIVER_TIMEOUT.
1447 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001448 if (!scmd->result)
1449 scmd->result |= (DRIVER_TIMEOUT << 24);
1450 SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush finish"
1451 " cmd: %p\n",
1452 current->comm, scmd));
1453 scsi_finish_command(scmd);
1454 }
1455 }
1456}
1457
1458/**
1459 * scsi_unjam_host - Attempt to fix a host which has a cmd that failed.
1460 * @shost: Host to unjam.
1461 *
1462 * Notes:
1463 * When we come in here, we *know* that all commands on the bus have
1464 * either completed, failed or timed out. we also know that no further
1465 * commands are being sent to the host, so things are relatively quiet
1466 * and we have freedom to fiddle with things as we wish.
1467 *
1468 * This is only the *default* implementation. it is possible for
1469 * individual drivers to supply their own version of this function, and
1470 * if the maintainer wishes to do this, it is strongly suggested that
1471 * this function be taken as a template and modified. this function
1472 * was designed to correctly handle problems for about 95% of the
1473 * different cases out there, and it should always provide at least a
1474 * reasonable amount of error recovery.
1475 *
1476 * Any command marked 'failed' or 'timeout' must eventually have
1477 * scsi_finish_cmd() called for it. we do all of the retry stuff
1478 * here, so when we restart the host after we return it should have an
1479 * empty queue.
1480 **/
1481static void scsi_unjam_host(struct Scsi_Host *shost)
1482{
1483 unsigned long flags;
1484 LIST_HEAD(eh_work_q);
1485 LIST_HEAD(eh_done_q);
1486
1487 spin_lock_irqsave(shost->host_lock, flags);
1488 list_splice_init(&shost->eh_cmd_q, &eh_work_q);
1489 spin_unlock_irqrestore(shost->host_lock, flags);
1490
1491 SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(shost, &eh_work_q));
1492
1493 if (!scsi_eh_get_sense(&eh_work_q, &eh_done_q))
1494 if (!scsi_eh_abort_cmds(&eh_work_q, &eh_done_q))
1495 scsi_eh_ready_devs(shost, &eh_work_q, &eh_done_q);
1496
1497 scsi_eh_flush_done_q(&eh_done_q);
1498}
1499
1500/**
Christoph Hellwigad42eb12005-10-29 01:01:55 +02001501 * scsi_error_handler - SCSI error handler thread
Linus Torvalds1da177e2005-04-16 15:20:36 -07001502 * @data: Host for which we are running.
1503 *
1504 * Notes:
Christoph Hellwigad42eb12005-10-29 01:01:55 +02001505 * This is the main error handling loop. This is run as a kernel thread
1506 * for every SCSI host and handles all error handling activity.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001507 **/
1508int scsi_error_handler(void *data)
1509{
Christoph Hellwigad42eb12005-10-29 01:01:55 +02001510 struct Scsi_Host *shost = data;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001511
Linus Torvalds1da177e2005-04-16 15:20:36 -07001512 current->flags |= PF_NOFREEZE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001513
1514 /*
Christoph Hellwigad42eb12005-10-29 01:01:55 +02001515 * We use TASK_INTERRUPTIBLE so that the thread is not
1516 * counted against the load average as a running process.
1517 * We never actually get interrupted because kthread_run
1518 * disables singal delivery for the created thread.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001519 */
James Bottomley3ed7a472005-09-19 09:50:04 -05001520 set_current_state(TASK_INTERRUPTIBLE);
1521 while (!kthread_should_stop()) {
1522 if (shost->host_failed == 0 ||
1523 shost->host_failed != shost->host_busy) {
Christoph Hellwigad42eb12005-10-29 01:01:55 +02001524 SCSI_LOG_ERROR_RECOVERY(1,
1525 printk("Error handler scsi_eh_%d sleeping\n",
1526 shost->host_no));
James Bottomley3ed7a472005-09-19 09:50:04 -05001527 schedule();
1528 set_current_state(TASK_INTERRUPTIBLE);
1529 continue;
1530 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001531
James Bottomley3ed7a472005-09-19 09:50:04 -05001532 __set_current_state(TASK_RUNNING);
Christoph Hellwigad42eb12005-10-29 01:01:55 +02001533 SCSI_LOG_ERROR_RECOVERY(1,
1534 printk("Error handler scsi_eh_%d waking up\n",
1535 shost->host_no));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001536
Linus Torvalds1da177e2005-04-16 15:20:36 -07001537 /*
1538 * We have a host that is failing for some reason. Figure out
1539 * what we need to do to get it up and online again (if we can).
1540 * If we fail, we end up taking the thing offline.
1541 */
1542 if (shost->hostt->eh_strategy_handler)
Christoph Hellwigad42eb12005-10-29 01:01:55 +02001543 shost->hostt->eh_strategy_handler(shost);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001544 else
1545 scsi_unjam_host(shost);
1546
Linus Torvalds1da177e2005-04-16 15:20:36 -07001547 /*
1548 * Note - if the above fails completely, the action is to take
1549 * individual devices offline and flush the queue of any
1550 * outstanding requests that may have been pending. When we
1551 * restart, we restart any I/O to any other devices on the bus
1552 * which are still online.
1553 */
1554 scsi_restart_operations(shost);
James Bottomley3ed7a472005-09-19 09:50:04 -05001555 set_current_state(TASK_INTERRUPTIBLE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001556 }
Steven Rostedt461a0ff2005-10-19 08:22:13 -04001557 __set_current_state(TASK_RUNNING);
1558
Christoph Hellwigad42eb12005-10-29 01:01:55 +02001559 SCSI_LOG_ERROR_RECOVERY(1,
1560 printk("Error handler scsi_eh_%d exiting\n", shost->host_no));
James Bottomley3ed7a472005-09-19 09:50:04 -05001561 shost->ehandler = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001562 return 0;
1563}
1564
1565/*
1566 * Function: scsi_report_bus_reset()
1567 *
1568 * Purpose: Utility function used by low-level drivers to report that
1569 * they have observed a bus reset on the bus being handled.
1570 *
1571 * Arguments: shost - Host in question
1572 * channel - channel on which reset was observed.
1573 *
1574 * Returns: Nothing
1575 *
1576 * Lock status: Host lock must be held.
1577 *
1578 * Notes: This only needs to be called if the reset is one which
1579 * originates from an unknown location. Resets originated
1580 * by the mid-level itself don't need to call this, but there
1581 * should be no harm.
1582 *
1583 * The main purpose of this is to make sure that a CHECK_CONDITION
1584 * is properly treated.
1585 */
1586void scsi_report_bus_reset(struct Scsi_Host *shost, int channel)
1587{
1588 struct scsi_device *sdev;
1589
1590 __shost_for_each_device(sdev, shost) {
Jeff Garzik422c0d62005-10-24 18:05:09 -04001591 if (channel == sdev_channel(sdev)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001592 sdev->was_reset = 1;
1593 sdev->expecting_cc_ua = 1;
1594 }
1595 }
1596}
1597EXPORT_SYMBOL(scsi_report_bus_reset);
1598
1599/*
1600 * Function: scsi_report_device_reset()
1601 *
1602 * Purpose: Utility function used by low-level drivers to report that
1603 * they have observed a device reset on the device being handled.
1604 *
1605 * Arguments: shost - Host in question
1606 * channel - channel on which reset was observed
1607 * target - target on which reset was observed
1608 *
1609 * Returns: Nothing
1610 *
1611 * Lock status: Host lock must be held
1612 *
1613 * Notes: This only needs to be called if the reset is one which
1614 * originates from an unknown location. Resets originated
1615 * by the mid-level itself don't need to call this, but there
1616 * should be no harm.
1617 *
1618 * The main purpose of this is to make sure that a CHECK_CONDITION
1619 * is properly treated.
1620 */
1621void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
1622{
1623 struct scsi_device *sdev;
1624
1625 __shost_for_each_device(sdev, shost) {
Jeff Garzik422c0d62005-10-24 18:05:09 -04001626 if (channel == sdev_channel(sdev) &&
1627 target == sdev_id(sdev)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001628 sdev->was_reset = 1;
1629 sdev->expecting_cc_ua = 1;
1630 }
1631 }
1632}
1633EXPORT_SYMBOL(scsi_report_device_reset);
1634
1635static void
1636scsi_reset_provider_done_command(struct scsi_cmnd *scmd)
1637{
1638}
1639
1640/*
1641 * Function: scsi_reset_provider
1642 *
1643 * Purpose: Send requested reset to a bus or device at any phase.
1644 *
1645 * Arguments: device - device to send reset to
1646 * flag - reset type (see scsi.h)
1647 *
1648 * Returns: SUCCESS/FAILURE.
1649 *
1650 * Notes: This is used by the SCSI Generic driver to provide
1651 * Bus/Device reset capability.
1652 */
1653int
1654scsi_reset_provider(struct scsi_device *dev, int flag)
1655{
1656 struct scsi_cmnd *scmd = scsi_get_command(dev, GFP_KERNEL);
1657 struct request req;
1658 int rtn;
1659
1660 scmd->request = &req;
1661 memset(&scmd->eh_timeout, 0, sizeof(scmd->eh_timeout));
1662 scmd->request->rq_status = RQ_SCSI_BUSY;
Christoph Hellwigb4edcbc2005-06-19 13:40:52 +02001663
Linus Torvalds1da177e2005-04-16 15:20:36 -07001664 memset(&scmd->cmnd, '\0', sizeof(scmd->cmnd));
1665
1666 scmd->scsi_done = scsi_reset_provider_done_command;
1667 scmd->done = NULL;
1668 scmd->buffer = NULL;
1669 scmd->bufflen = 0;
1670 scmd->request_buffer = NULL;
1671 scmd->request_bufflen = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001672
1673 scmd->cmd_len = 0;
1674
1675 scmd->sc_data_direction = DMA_BIDIRECTIONAL;
1676 scmd->sc_request = NULL;
1677 scmd->sc_magic = SCSI_CMND_MAGIC;
1678
1679 init_timer(&scmd->eh_timeout);
1680
1681 /*
1682 * Sometimes the command can get back into the timer chain,
1683 * so use the pid as an identifier.
1684 */
1685 scmd->pid = 0;
1686
1687 switch (flag) {
1688 case SCSI_TRY_RESET_DEVICE:
1689 rtn = scsi_try_bus_device_reset(scmd);
1690 if (rtn == SUCCESS)
1691 break;
1692 /* FALLTHROUGH */
1693 case SCSI_TRY_RESET_BUS:
1694 rtn = scsi_try_bus_reset(scmd);
1695 if (rtn == SUCCESS)
1696 break;
1697 /* FALLTHROUGH */
1698 case SCSI_TRY_RESET_HOST:
1699 rtn = scsi_try_host_reset(scmd);
1700 break;
1701 default:
1702 rtn = FAILED;
1703 }
1704
Linus Torvalds1da177e2005-04-16 15:20:36 -07001705 scsi_next_command(scmd);
1706 return rtn;
1707}
1708EXPORT_SYMBOL(scsi_reset_provider);
1709
1710/**
1711 * scsi_normalize_sense - normalize main elements from either fixed or
1712 * descriptor sense data format into a common format.
1713 *
1714 * @sense_buffer: byte array containing sense data returned by device
1715 * @sb_len: number of valid bytes in sense_buffer
1716 * @sshdr: pointer to instance of structure that common
1717 * elements are written to.
1718 *
1719 * Notes:
1720 * The "main elements" from sense data are: response_code, sense_key,
1721 * asc, ascq and additional_length (only for descriptor format).
1722 *
1723 * Typically this function can be called after a device has
1724 * responded to a SCSI command with the CHECK_CONDITION status.
1725 *
1726 * Return value:
1727 * 1 if valid sense data information found, else 0;
1728 **/
1729int scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
1730 struct scsi_sense_hdr *sshdr)
1731{
James Bottomley33aa6872005-08-28 11:31:14 -05001732 if (!sense_buffer || !sb_len)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001733 return 0;
1734
1735 memset(sshdr, 0, sizeof(struct scsi_sense_hdr));
1736
1737 sshdr->response_code = (sense_buffer[0] & 0x7f);
James Bottomley33aa6872005-08-28 11:31:14 -05001738
1739 if (!scsi_sense_valid(sshdr))
1740 return 0;
1741
Linus Torvalds1da177e2005-04-16 15:20:36 -07001742 if (sshdr->response_code >= 0x72) {
1743 /*
1744 * descriptor format
1745 */
1746 if (sb_len > 1)
1747 sshdr->sense_key = (sense_buffer[1] & 0xf);
1748 if (sb_len > 2)
1749 sshdr->asc = sense_buffer[2];
1750 if (sb_len > 3)
1751 sshdr->ascq = sense_buffer[3];
1752 if (sb_len > 7)
1753 sshdr->additional_length = sense_buffer[7];
1754 } else {
1755 /*
1756 * fixed format
1757 */
1758 if (sb_len > 2)
1759 sshdr->sense_key = (sense_buffer[2] & 0xf);
1760 if (sb_len > 7) {
1761 sb_len = (sb_len < (sense_buffer[7] + 8)) ?
1762 sb_len : (sense_buffer[7] + 8);
1763 if (sb_len > 12)
1764 sshdr->asc = sense_buffer[12];
1765 if (sb_len > 13)
1766 sshdr->ascq = sense_buffer[13];
1767 }
1768 }
1769
1770 return 1;
1771}
1772EXPORT_SYMBOL(scsi_normalize_sense);
1773
1774int scsi_request_normalize_sense(struct scsi_request *sreq,
1775 struct scsi_sense_hdr *sshdr)
1776{
1777 return scsi_normalize_sense(sreq->sr_sense_buffer,
1778 sizeof(sreq->sr_sense_buffer), sshdr);
1779}
1780EXPORT_SYMBOL(scsi_request_normalize_sense);
1781
1782int scsi_command_normalize_sense(struct scsi_cmnd *cmd,
1783 struct scsi_sense_hdr *sshdr)
1784{
1785 return scsi_normalize_sense(cmd->sense_buffer,
1786 sizeof(cmd->sense_buffer), sshdr);
1787}
1788EXPORT_SYMBOL(scsi_command_normalize_sense);
1789
1790/**
1791 * scsi_sense_desc_find - search for a given descriptor type in
1792 * descriptor sense data format.
1793 *
1794 * @sense_buffer: byte array of descriptor format sense data
1795 * @sb_len: number of valid bytes in sense_buffer
1796 * @desc_type: value of descriptor type to find
1797 * (e.g. 0 -> information)
1798 *
1799 * Notes:
1800 * only valid when sense data is in descriptor format
1801 *
1802 * Return value:
1803 * pointer to start of (first) descriptor if found else NULL
1804 **/
1805const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
1806 int desc_type)
1807{
1808 int add_sen_len, add_len, desc_len, k;
1809 const u8 * descp;
1810
1811 if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7])))
1812 return NULL;
1813 if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73))
1814 return NULL;
1815 add_sen_len = (add_sen_len < (sb_len - 8)) ?
1816 add_sen_len : (sb_len - 8);
1817 descp = &sense_buffer[8];
1818 for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) {
1819 descp += desc_len;
1820 add_len = (k < (add_sen_len - 1)) ? descp[1]: -1;
1821 desc_len = add_len + 2;
1822 if (descp[0] == desc_type)
1823 return descp;
1824 if (add_len < 0) // short descriptor ??
1825 break;
1826 }
1827 return NULL;
1828}
1829EXPORT_SYMBOL(scsi_sense_desc_find);
1830
1831/**
1832 * scsi_get_sense_info_fld - attempts to get information field from
1833 * sense data (either fixed or descriptor format)
1834 *
1835 * @sense_buffer: byte array of sense data
1836 * @sb_len: number of valid bytes in sense_buffer
1837 * @info_out: pointer to 64 integer where 8 or 4 byte information
1838 * field will be placed if found.
1839 *
1840 * Return value:
1841 * 1 if information field found, 0 if not found.
1842 **/
1843int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len,
1844 u64 * info_out)
1845{
1846 int j;
1847 const u8 * ucp;
1848 u64 ull;
1849
1850 if (sb_len < 7)
1851 return 0;
1852 switch (sense_buffer[0] & 0x7f) {
1853 case 0x70:
1854 case 0x71:
1855 if (sense_buffer[0] & 0x80) {
1856 *info_out = (sense_buffer[3] << 24) +
1857 (sense_buffer[4] << 16) +
1858 (sense_buffer[5] << 8) + sense_buffer[6];
1859 return 1;
1860 } else
1861 return 0;
1862 case 0x72:
1863 case 0x73:
1864 ucp = scsi_sense_desc_find(sense_buffer, sb_len,
1865 0 /* info desc */);
1866 if (ucp && (0xa == ucp[1])) {
1867 ull = 0;
1868 for (j = 0; j < 8; ++j) {
1869 if (j > 0)
1870 ull <<= 8;
1871 ull |= ucp[4 + j];
1872 }
1873 *info_out = ull;
1874 return 1;
1875 } else
1876 return 0;
1877 default:
1878 return 0;
1879 }
1880}
1881EXPORT_SYMBOL(scsi_get_sense_info_fld);