diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/scsi/scsi_error.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/scsi/scsi_error.c')
-rw-r--r-- | drivers/scsi/scsi_error.c | 2050 |
1 files changed, 2050 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c new file mode 100644 index 000000000000..9bc597bd13ba --- /dev/null +++ b/drivers/scsi/scsi_error.c | |||
@@ -0,0 +1,2050 @@ | |||
1 | /* | ||
2 | * scsi_error.c Copyright (C) 1997 Eric Youngdale | ||
3 | * | ||
4 | * SCSI error/timeout handling | ||
5 | * Initial versions: Eric Youngdale. Based upon conversations with | ||
6 | * Leonard Zubkoff and David Miller at Linux Expo, | ||
7 | * ideas originating from all over the place. | ||
8 | * | ||
9 | * Restructured scsi_unjam_host and associated functions. | ||
10 | * September 04, 2002 Mike Anderson (andmike@us.ibm.com) | ||
11 | * | ||
12 | * Forward port of Russell King's (rmk@arm.linux.org.uk) changes and | ||
13 | * minor cleanups. | ||
14 | * September 30, 2002 Mike Anderson (andmike@us.ibm.com) | ||
15 | */ | ||
16 | |||
17 | #include <linux/module.h> | ||
18 | #include <linux/sched.h> | ||
19 | #include <linux/timer.h> | ||
20 | #include <linux/string.h> | ||
21 | #include <linux/slab.h> | ||
22 | #include <linux/kernel.h> | ||
23 | #include <linux/interrupt.h> | ||
24 | #include <linux/blkdev.h> | ||
25 | #include <linux/delay.h> | ||
26 | |||
27 | #include <scsi/scsi.h> | ||
28 | #include <scsi/scsi_dbg.h> | ||
29 | #include <scsi/scsi_device.h> | ||
30 | #include <scsi/scsi_eh.h> | ||
31 | #include <scsi/scsi_host.h> | ||
32 | #include <scsi/scsi_ioctl.h> | ||
33 | #include <scsi/scsi_request.h> | ||
34 | |||
35 | #include "scsi_priv.h" | ||
36 | #include "scsi_logging.h" | ||
37 | |||
38 | #define SENSE_TIMEOUT (10*HZ) | ||
39 | #define START_UNIT_TIMEOUT (30*HZ) | ||
40 | |||
41 | /* | ||
42 | * These should *probably* be handled by the host itself. | ||
43 | * Since it is allowed to sleep, it probably should. | ||
44 | */ | ||
45 | #define BUS_RESET_SETTLE_TIME (10) | ||
46 | #define HOST_RESET_SETTLE_TIME (10) | ||
47 | |||
48 | /* called with shost->host_lock held */ | ||
49 | void scsi_eh_wakeup(struct Scsi_Host *shost) | ||
50 | { | ||
51 | if (shost->host_busy == shost->host_failed) { | ||
52 | up(shost->eh_wait); | ||
53 | SCSI_LOG_ERROR_RECOVERY(5, | ||
54 | printk("Waking error handler thread\n")); | ||
55 | } | ||
56 | } | ||
57 | |||
58 | /** | ||
59 | * scsi_eh_scmd_add - add scsi cmd to error handling. | ||
60 | * @scmd: scmd to run eh on. | ||
61 | * @eh_flag: optional SCSI_EH flag. | ||
62 | * | ||
63 | * Return value: | ||
64 | * 0 on failure. | ||
65 | **/ | ||
66 | int scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag) | ||
67 | { | ||
68 | struct Scsi_Host *shost = scmd->device->host; | ||
69 | unsigned long flags; | ||
70 | |||
71 | if (shost->eh_wait == NULL) | ||
72 | return 0; | ||
73 | |||
74 | spin_lock_irqsave(shost->host_lock, flags); | ||
75 | |||
76 | scsi_eh_eflags_set(scmd, eh_flag); | ||
77 | /* | ||
78 | * FIXME: Can we stop setting owner and state. | ||
79 | */ | ||
80 | scmd->owner = SCSI_OWNER_ERROR_HANDLER; | ||
81 | scmd->state = SCSI_STATE_FAILED; | ||
82 | /* | ||
83 | * Set the serial_number_at_timeout to the current | ||
84 | * serial_number | ||
85 | */ | ||
86 | scmd->serial_number_at_timeout = scmd->serial_number; | ||
87 | list_add_tail(&scmd->eh_entry, &shost->eh_cmd_q); | ||
88 | set_bit(SHOST_RECOVERY, &shost->shost_state); | ||
89 | shost->host_failed++; | ||
90 | scsi_eh_wakeup(shost); | ||
91 | spin_unlock_irqrestore(shost->host_lock, flags); | ||
92 | return 1; | ||
93 | } | ||
94 | |||
95 | /** | ||
96 | * scsi_add_timer - Start timeout timer for a single scsi command. | ||
97 | * @scmd: scsi command that is about to start running. | ||
98 | * @timeout: amount of time to allow this command to run. | ||
99 | * @complete: timeout function to call if timer isn't canceled. | ||
100 | * | ||
101 | * Notes: | ||
102 | * This should be turned into an inline function. Each scsi command | ||
103 | * has its own timer, and as it is added to the queue, we set up the | ||
104 | * timer. When the command completes, we cancel the timer. | ||
105 | **/ | ||
106 | void scsi_add_timer(struct scsi_cmnd *scmd, int timeout, | ||
107 | void (*complete)(struct scsi_cmnd *)) | ||
108 | { | ||
109 | |||
110 | /* | ||
111 | * If the clock was already running for this command, then | ||
112 | * first delete the timer. The timer handling code gets rather | ||
113 | * confused if we don't do this. | ||
114 | */ | ||
115 | if (scmd->eh_timeout.function) | ||
116 | del_timer(&scmd->eh_timeout); | ||
117 | |||
118 | scmd->eh_timeout.data = (unsigned long)scmd; | ||
119 | scmd->eh_timeout.expires = jiffies + timeout; | ||
120 | scmd->eh_timeout.function = (void (*)(unsigned long)) complete; | ||
121 | |||
122 | SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p, time:" | ||
123 | " %d, (%p)\n", __FUNCTION__, | ||
124 | scmd, timeout, complete)); | ||
125 | |||
126 | add_timer(&scmd->eh_timeout); | ||
127 | } | ||
128 | EXPORT_SYMBOL(scsi_add_timer); | ||
129 | |||
130 | /** | ||
131 | * scsi_delete_timer - Delete/cancel timer for a given function. | ||
132 | * @scmd: Cmd that we are canceling timer for | ||
133 | * | ||
134 | * Notes: | ||
135 | * This should be turned into an inline function. | ||
136 | * | ||
137 | * Return value: | ||
138 | * 1 if we were able to detach the timer. 0 if we blew it, and the | ||
139 | * timer function has already started to run. | ||
140 | **/ | ||
141 | int scsi_delete_timer(struct scsi_cmnd *scmd) | ||
142 | { | ||
143 | int rtn; | ||
144 | |||
145 | rtn = del_timer(&scmd->eh_timeout); | ||
146 | |||
147 | SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p," | ||
148 | " rtn: %d\n", __FUNCTION__, | ||
149 | scmd, rtn)); | ||
150 | |||
151 | scmd->eh_timeout.data = (unsigned long)NULL; | ||
152 | scmd->eh_timeout.function = NULL; | ||
153 | |||
154 | return rtn; | ||
155 | } | ||
156 | EXPORT_SYMBOL(scsi_delete_timer); | ||
157 | |||
158 | /** | ||
159 | * scsi_times_out - Timeout function for normal scsi commands. | ||
160 | * @scmd: Cmd that is timing out. | ||
161 | * | ||
162 | * Notes: | ||
163 | * We do not need to lock this. There is the potential for a race | ||
164 | * only in that the normal completion handling might run, but if the | ||
165 | * normal completion function determines that the timer has already | ||
166 | * fired, then it mustn't do anything. | ||
167 | **/ | ||
168 | void scsi_times_out(struct scsi_cmnd *scmd) | ||
169 | { | ||
170 | scsi_log_completion(scmd, TIMEOUT_ERROR); | ||
171 | |||
172 | if (scmd->device->host->hostt->eh_timed_out) | ||
173 | switch (scmd->device->host->hostt->eh_timed_out(scmd)) { | ||
174 | case EH_HANDLED: | ||
175 | __scsi_done(scmd); | ||
176 | return; | ||
177 | case EH_RESET_TIMER: | ||
178 | /* This allows a single retry even of a command | ||
179 | * with allowed == 0 */ | ||
180 | if (scmd->retries++ > scmd->allowed) | ||
181 | break; | ||
182 | scsi_add_timer(scmd, scmd->timeout_per_command, | ||
183 | scsi_times_out); | ||
184 | return; | ||
185 | case EH_NOT_HANDLED: | ||
186 | break; | ||
187 | } | ||
188 | |||
189 | if (unlikely(!scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD))) { | ||
190 | panic("Error handler thread not present at %p %p %s %d", | ||
191 | scmd, scmd->device->host, __FILE__, __LINE__); | ||
192 | } | ||
193 | } | ||
194 | |||
195 | /** | ||
196 | * scsi_block_when_processing_errors - Prevent cmds from being queued. | ||
197 | * @sdev: Device on which we are performing recovery. | ||
198 | * | ||
199 | * Description: | ||
200 | * We block until the host is out of error recovery, and then check to | ||
201 | * see whether the host or the device is offline. | ||
202 | * | ||
203 | * Return value: | ||
204 | * 0 when dev was taken offline by error recovery. 1 OK to proceed. | ||
205 | **/ | ||
206 | int scsi_block_when_processing_errors(struct scsi_device *sdev) | ||
207 | { | ||
208 | int online; | ||
209 | |||
210 | wait_event(sdev->host->host_wait, (!test_bit(SHOST_RECOVERY, &sdev->host->shost_state))); | ||
211 | |||
212 | online = scsi_device_online(sdev); | ||
213 | |||
214 | SCSI_LOG_ERROR_RECOVERY(5, printk("%s: rtn: %d\n", __FUNCTION__, | ||
215 | online)); | ||
216 | |||
217 | return online; | ||
218 | } | ||
219 | EXPORT_SYMBOL(scsi_block_when_processing_errors); | ||
220 | |||
221 | #ifdef CONFIG_SCSI_LOGGING | ||
222 | /** | ||
223 | * scsi_eh_prt_fail_stats - Log info on failures. | ||
224 | * @shost: scsi host being recovered. | ||
225 | * @work_q: Queue of scsi cmds to process. | ||
226 | **/ | ||
227 | static inline void scsi_eh_prt_fail_stats(struct Scsi_Host *shost, | ||
228 | struct list_head *work_q) | ||
229 | { | ||
230 | struct scsi_cmnd *scmd; | ||
231 | struct scsi_device *sdev; | ||
232 | int total_failures = 0; | ||
233 | int cmd_failed = 0; | ||
234 | int cmd_cancel = 0; | ||
235 | int devices_failed = 0; | ||
236 | |||
237 | shost_for_each_device(sdev, shost) { | ||
238 | list_for_each_entry(scmd, work_q, eh_entry) { | ||
239 | if (scmd->device == sdev) { | ||
240 | ++total_failures; | ||
241 | if (scsi_eh_eflags_chk(scmd, | ||
242 | SCSI_EH_CANCEL_CMD)) | ||
243 | ++cmd_cancel; | ||
244 | else | ||
245 | ++cmd_failed; | ||
246 | } | ||
247 | } | ||
248 | |||
249 | if (cmd_cancel || cmd_failed) { | ||
250 | SCSI_LOG_ERROR_RECOVERY(3, | ||
251 | printk("%s: %d:%d:%d:%d cmds failed: %d," | ||
252 | " cancel: %d\n", | ||
253 | __FUNCTION__, shost->host_no, | ||
254 | sdev->channel, sdev->id, sdev->lun, | ||
255 | cmd_failed, cmd_cancel)); | ||
256 | cmd_cancel = 0; | ||
257 | cmd_failed = 0; | ||
258 | ++devices_failed; | ||
259 | } | ||
260 | } | ||
261 | |||
262 | SCSI_LOG_ERROR_RECOVERY(2, printk("Total of %d commands on %d" | ||
263 | " devices require eh work\n", | ||
264 | total_failures, devices_failed)); | ||
265 | } | ||
266 | #endif | ||
267 | |||
268 | /** | ||
269 | * scsi_check_sense - Examine scsi cmd sense | ||
270 | * @scmd: Cmd to have sense checked. | ||
271 | * | ||
272 | * Return value: | ||
273 | * SUCCESS or FAILED or NEEDS_RETRY | ||
274 | * | ||
275 | * Notes: | ||
276 | * When a deferred error is detected the current command has | ||
277 | * not been executed and needs retrying. | ||
278 | **/ | ||
279 | static int scsi_check_sense(struct scsi_cmnd *scmd) | ||
280 | { | ||
281 | struct scsi_sense_hdr sshdr; | ||
282 | |||
283 | if (! scsi_command_normalize_sense(scmd, &sshdr)) | ||
284 | return FAILED; /* no valid sense data */ | ||
285 | |||
286 | if (scsi_sense_is_deferred(&sshdr)) | ||
287 | return NEEDS_RETRY; | ||
288 | |||
289 | /* | ||
290 | * Previous logic looked for FILEMARK, EOM or ILI which are | ||
291 | * mainly associated with tapes and returned SUCCESS. | ||
292 | */ | ||
293 | if (sshdr.response_code == 0x70) { | ||
294 | /* fixed format */ | ||
295 | if (scmd->sense_buffer[2] & 0xe0) | ||
296 | return SUCCESS; | ||
297 | } else { | ||
298 | /* | ||
299 | * descriptor format: look for "stream commands sense data | ||
300 | * descriptor" (see SSC-3). Assume single sense data | ||
301 | * descriptor. Ignore ILI from SBC-2 READ LONG and WRITE LONG. | ||
302 | */ | ||
303 | if ((sshdr.additional_length > 3) && | ||
304 | (scmd->sense_buffer[8] == 0x4) && | ||
305 | (scmd->sense_buffer[11] & 0xe0)) | ||
306 | return SUCCESS; | ||
307 | } | ||
308 | |||
309 | switch (sshdr.sense_key) { | ||
310 | case NO_SENSE: | ||
311 | return SUCCESS; | ||
312 | case RECOVERED_ERROR: | ||
313 | return /* soft_error */ SUCCESS; | ||
314 | |||
315 | case ABORTED_COMMAND: | ||
316 | return NEEDS_RETRY; | ||
317 | case NOT_READY: | ||
318 | case UNIT_ATTENTION: | ||
319 | /* | ||
320 | * if we are expecting a cc/ua because of a bus reset that we | ||
321 | * performed, treat this just as a retry. otherwise this is | ||
322 | * information that we should pass up to the upper-level driver | ||
323 | * so that we can deal with it there. | ||
324 | */ | ||
325 | if (scmd->device->expecting_cc_ua) { | ||
326 | scmd->device->expecting_cc_ua = 0; | ||
327 | return NEEDS_RETRY; | ||
328 | } | ||
329 | /* | ||
330 | * if the device is in the process of becoming ready, we | ||
331 | * should retry. | ||
332 | */ | ||
333 | if ((sshdr.asc == 0x04) && (sshdr.ascq == 0x01)) | ||
334 | return NEEDS_RETRY; | ||
335 | /* | ||
336 | * if the device is not started, we need to wake | ||
337 | * the error handler to start the motor | ||
338 | */ | ||
339 | if (scmd->device->allow_restart && | ||
340 | (sshdr.asc == 0x04) && (sshdr.ascq == 0x02)) | ||
341 | return FAILED; | ||
342 | return SUCCESS; | ||
343 | |||
344 | /* these three are not supported */ | ||
345 | case COPY_ABORTED: | ||
346 | case VOLUME_OVERFLOW: | ||
347 | case MISCOMPARE: | ||
348 | return SUCCESS; | ||
349 | |||
350 | case MEDIUM_ERROR: | ||
351 | return NEEDS_RETRY; | ||
352 | |||
353 | case HARDWARE_ERROR: | ||
354 | if (scmd->device->retry_hwerror) | ||
355 | return NEEDS_RETRY; | ||
356 | else | ||
357 | return SUCCESS; | ||
358 | |||
359 | case ILLEGAL_REQUEST: | ||
360 | case BLANK_CHECK: | ||
361 | case DATA_PROTECT: | ||
362 | default: | ||
363 | return SUCCESS; | ||
364 | } | ||
365 | } | ||
366 | |||
367 | /** | ||
368 | * scsi_eh_completed_normally - Disposition a eh cmd on return from LLD. | ||
369 | * @scmd: SCSI cmd to examine. | ||
370 | * | ||
371 | * Notes: | ||
372 | * This is *only* called when we are examining the status of commands | ||
373 | * queued during error recovery. the main difference here is that we | ||
374 | * don't allow for the possibility of retries here, and we are a lot | ||
375 | * more restrictive about what we consider acceptable. | ||
376 | **/ | ||
377 | static int scsi_eh_completed_normally(struct scsi_cmnd *scmd) | ||
378 | { | ||
379 | /* | ||
380 | * first check the host byte, to see if there is anything in there | ||
381 | * that would indicate what we need to do. | ||
382 | */ | ||
383 | if (host_byte(scmd->result) == DID_RESET) { | ||
384 | /* | ||
385 | * rats. we are already in the error handler, so we now | ||
386 | * get to try and figure out what to do next. if the sense | ||
387 | * is valid, we have a pretty good idea of what to do. | ||
388 | * if not, we mark it as FAILED. | ||
389 | */ | ||
390 | return scsi_check_sense(scmd); | ||
391 | } | ||
392 | if (host_byte(scmd->result) != DID_OK) | ||
393 | return FAILED; | ||
394 | |||
395 | /* | ||
396 | * next, check the message byte. | ||
397 | */ | ||
398 | if (msg_byte(scmd->result) != COMMAND_COMPLETE) | ||
399 | return FAILED; | ||
400 | |||
401 | /* | ||
402 | * now, check the status byte to see if this indicates | ||
403 | * anything special. | ||
404 | */ | ||
405 | switch (status_byte(scmd->result)) { | ||
406 | case GOOD: | ||
407 | case COMMAND_TERMINATED: | ||
408 | return SUCCESS; | ||
409 | case CHECK_CONDITION: | ||
410 | return scsi_check_sense(scmd); | ||
411 | case CONDITION_GOOD: | ||
412 | case INTERMEDIATE_GOOD: | ||
413 | case INTERMEDIATE_C_GOOD: | ||
414 | /* | ||
415 | * who knows? FIXME(eric) | ||
416 | */ | ||
417 | return SUCCESS; | ||
418 | case BUSY: | ||
419 | case QUEUE_FULL: | ||
420 | case RESERVATION_CONFLICT: | ||
421 | default: | ||
422 | return FAILED; | ||
423 | } | ||
424 | return FAILED; | ||
425 | } | ||
426 | |||
427 | /** | ||
428 | * scsi_eh_times_out - timeout function for error handling. | ||
429 | * @scmd: Cmd that is timing out. | ||
430 | * | ||
431 | * Notes: | ||
432 | * During error handling, the kernel thread will be sleeping waiting | ||
433 | * for some action to complete on the device. our only job is to | ||
434 | * record that it timed out, and to wake up the thread. | ||
435 | **/ | ||
436 | static void scsi_eh_times_out(struct scsi_cmnd *scmd) | ||
437 | { | ||
438 | scsi_eh_eflags_set(scmd, SCSI_EH_REC_TIMEOUT); | ||
439 | SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd:%p\n", __FUNCTION__, | ||
440 | scmd)); | ||
441 | |||
442 | if (scmd->device->host->eh_action) | ||
443 | up(scmd->device->host->eh_action); | ||
444 | } | ||
445 | |||
446 | /** | ||
447 | * scsi_eh_done - Completion function for error handling. | ||
448 | * @scmd: Cmd that is done. | ||
449 | **/ | ||
450 | static void scsi_eh_done(struct scsi_cmnd *scmd) | ||
451 | { | ||
452 | /* | ||
453 | * if the timeout handler is already running, then just set the | ||
454 | * flag which says we finished late, and return. we have no | ||
455 | * way of stopping the timeout handler from running, so we must | ||
456 | * always defer to it. | ||
457 | */ | ||
458 | if (del_timer(&scmd->eh_timeout)) { | ||
459 | scmd->request->rq_status = RQ_SCSI_DONE; | ||
460 | scmd->owner = SCSI_OWNER_ERROR_HANDLER; | ||
461 | |||
462 | SCSI_LOG_ERROR_RECOVERY(3, printk("%s scmd: %p result: %x\n", | ||
463 | __FUNCTION__, scmd, scmd->result)); | ||
464 | |||
465 | if (scmd->device->host->eh_action) | ||
466 | up(scmd->device->host->eh_action); | ||
467 | } | ||
468 | } | ||
469 | |||
470 | /** | ||
471 | * scsi_send_eh_cmnd - send a cmd to a device as part of error recovery. | ||
472 | * @scmd: SCSI Cmd to send. | ||
473 | * @timeout: Timeout for cmd. | ||
474 | * | ||
475 | * Notes: | ||
476 | * The initialization of the structures is quite a bit different in | ||
477 | * this case, and furthermore, there is a different completion handler | ||
478 | * vs scsi_dispatch_cmd. | ||
479 | * Return value: | ||
480 | * SUCCESS or FAILED or NEEDS_RETRY | ||
481 | **/ | ||
482 | static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, int timeout) | ||
483 | { | ||
484 | struct Scsi_Host *host = scmd->device->host; | ||
485 | DECLARE_MUTEX_LOCKED(sem); | ||
486 | unsigned long flags; | ||
487 | int rtn = SUCCESS; | ||
488 | |||
489 | /* | ||
490 | * we will use a queued command if possible, otherwise we will | ||
491 | * emulate the queuing and calling of completion function ourselves. | ||
492 | */ | ||
493 | scmd->owner = SCSI_OWNER_LOWLEVEL; | ||
494 | |||
495 | if (scmd->device->scsi_level <= SCSI_2) | ||
496 | scmd->cmnd[1] = (scmd->cmnd[1] & 0x1f) | | ||
497 | (scmd->device->lun << 5 & 0xe0); | ||
498 | |||
499 | scsi_add_timer(scmd, timeout, scsi_eh_times_out); | ||
500 | |||
501 | /* | ||
502 | * set up the semaphore so we wait for the command to complete. | ||
503 | */ | ||
504 | scmd->device->host->eh_action = &sem; | ||
505 | scmd->request->rq_status = RQ_SCSI_BUSY; | ||
506 | |||
507 | spin_lock_irqsave(scmd->device->host->host_lock, flags); | ||
508 | scsi_log_send(scmd); | ||
509 | host->hostt->queuecommand(scmd, scsi_eh_done); | ||
510 | spin_unlock_irqrestore(scmd->device->host->host_lock, flags); | ||
511 | |||
512 | down(&sem); | ||
513 | scsi_log_completion(scmd, SUCCESS); | ||
514 | |||
515 | scmd->device->host->eh_action = NULL; | ||
516 | |||
517 | /* | ||
518 | * see if timeout. if so, tell the host to forget about it. | ||
519 | * in other words, we don't want a callback any more. | ||
520 | */ | ||
521 | if (scsi_eh_eflags_chk(scmd, SCSI_EH_REC_TIMEOUT)) { | ||
522 | scsi_eh_eflags_clr(scmd, SCSI_EH_REC_TIMEOUT); | ||
523 | scmd->owner = SCSI_OWNER_LOWLEVEL; | ||
524 | |||
525 | /* | ||
526 | * as far as the low level driver is | ||
527 | * concerned, this command is still active, so | ||
528 | * we must give the low level driver a chance | ||
529 | * to abort it. (db) | ||
530 | * | ||
531 | * FIXME(eric) - we are not tracking whether we could | ||
532 | * abort a timed out command or not. not sure how | ||
533 | * we should treat them differently anyways. | ||
534 | */ | ||
535 | spin_lock_irqsave(scmd->device->host->host_lock, flags); | ||
536 | if (scmd->device->host->hostt->eh_abort_handler) | ||
537 | scmd->device->host->hostt->eh_abort_handler(scmd); | ||
538 | spin_unlock_irqrestore(scmd->device->host->host_lock, flags); | ||
539 | |||
540 | scmd->request->rq_status = RQ_SCSI_DONE; | ||
541 | scmd->owner = SCSI_OWNER_ERROR_HANDLER; | ||
542 | |||
543 | rtn = FAILED; | ||
544 | } | ||
545 | |||
546 | SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd: %p, rtn:%x\n", | ||
547 | __FUNCTION__, scmd, rtn)); | ||
548 | |||
549 | /* | ||
550 | * now examine the actual status codes to see whether the command | ||
551 | * actually did complete normally. | ||
552 | */ | ||
553 | if (rtn == SUCCESS) { | ||
554 | rtn = scsi_eh_completed_normally(scmd); | ||
555 | SCSI_LOG_ERROR_RECOVERY(3, | ||
556 | printk("%s: scsi_eh_completed_normally %x\n", | ||
557 | __FUNCTION__, rtn)); | ||
558 | switch (rtn) { | ||
559 | case SUCCESS: | ||
560 | case NEEDS_RETRY: | ||
561 | case FAILED: | ||
562 | break; | ||
563 | default: | ||
564 | rtn = FAILED; | ||
565 | break; | ||
566 | } | ||
567 | } | ||
568 | |||
569 | return rtn; | ||
570 | } | ||
571 | |||
572 | /** | ||
573 | * scsi_request_sense - Request sense data from a particular target. | ||
574 | * @scmd: SCSI cmd for request sense. | ||
575 | * | ||
576 | * Notes: | ||
577 | * Some hosts automatically obtain this information, others require | ||
578 | * that we obtain it on our own. This function will *not* return until | ||
579 | * the command either times out, or it completes. | ||
580 | **/ | ||
581 | static int scsi_request_sense(struct scsi_cmnd *scmd) | ||
582 | { | ||
583 | static unsigned char generic_sense[6] = | ||
584 | {REQUEST_SENSE, 0, 0, 0, 252, 0}; | ||
585 | unsigned char *scsi_result; | ||
586 | int saved_result; | ||
587 | int rtn; | ||
588 | |||
589 | memcpy(scmd->cmnd, generic_sense, sizeof(generic_sense)); | ||
590 | |||
591 | scsi_result = kmalloc(252, GFP_ATOMIC | (scmd->device->host->hostt->unchecked_isa_dma) ? __GFP_DMA : 0); | ||
592 | |||
593 | |||
594 | if (unlikely(!scsi_result)) { | ||
595 | printk(KERN_ERR "%s: cannot allocate scsi_result.\n", | ||
596 | __FUNCTION__); | ||
597 | return FAILED; | ||
598 | } | ||
599 | |||
600 | /* | ||
601 | * zero the sense buffer. some host adapters automatically always | ||
602 | * request sense, so it is not a good idea that | ||
603 | * scmd->request_buffer and scmd->sense_buffer point to the same | ||
604 | * address (db). 0 is not a valid sense code. | ||
605 | */ | ||
606 | memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer)); | ||
607 | memset(scsi_result, 0, 252); | ||
608 | |||
609 | saved_result = scmd->result; | ||
610 | scmd->request_buffer = scsi_result; | ||
611 | scmd->request_bufflen = 252; | ||
612 | scmd->use_sg = 0; | ||
613 | scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]); | ||
614 | scmd->sc_data_direction = DMA_FROM_DEVICE; | ||
615 | scmd->underflow = 0; | ||
616 | |||
617 | rtn = scsi_send_eh_cmnd(scmd, SENSE_TIMEOUT); | ||
618 | |||
619 | /* last chance to have valid sense data */ | ||
620 | if(!SCSI_SENSE_VALID(scmd)) { | ||
621 | memcpy(scmd->sense_buffer, scmd->request_buffer, | ||
622 | sizeof(scmd->sense_buffer)); | ||
623 | } | ||
624 | |||
625 | kfree(scsi_result); | ||
626 | |||
627 | /* | ||
628 | * when we eventually call scsi_finish, we really wish to complete | ||
629 | * the original request, so let's restore the original data. (db) | ||
630 | */ | ||
631 | scsi_setup_cmd_retry(scmd); | ||
632 | scmd->result = saved_result; | ||
633 | return rtn; | ||
634 | } | ||
635 | |||
636 | /** | ||
637 | * scsi_eh_finish_cmd - Handle a cmd that eh is finished with. | ||
638 | * @scmd: Original SCSI cmd that eh has finished. | ||
639 | * @done_q: Queue for processed commands. | ||
640 | * | ||
641 | * Notes: | ||
642 | * We don't want to use the normal command completion while we are are | ||
643 | * still handling errors - it may cause other commands to be queued, | ||
644 | * and that would disturb what we are doing. thus we really want to | ||
645 | * keep a list of pending commands for final completion, and once we | ||
646 | * are ready to leave error handling we handle completion for real. | ||
647 | **/ | ||
648 | static void scsi_eh_finish_cmd(struct scsi_cmnd *scmd, | ||
649 | struct list_head *done_q) | ||
650 | { | ||
651 | scmd->device->host->host_failed--; | ||
652 | scmd->state = SCSI_STATE_BHQUEUE; | ||
653 | |||
654 | scsi_eh_eflags_clr_all(scmd); | ||
655 | |||
656 | /* | ||
657 | * set this back so that the upper level can correctly free up | ||
658 | * things. | ||
659 | */ | ||
660 | scsi_setup_cmd_retry(scmd); | ||
661 | list_move_tail(&scmd->eh_entry, done_q); | ||
662 | } | ||
663 | |||
664 | /** | ||
665 | * scsi_eh_get_sense - Get device sense data. | ||
666 | * @work_q: Queue of commands to process. | ||
667 | * @done_q: Queue of proccessed commands.. | ||
668 | * | ||
669 | * Description: | ||
670 | * See if we need to request sense information. if so, then get it | ||
671 | * now, so we have a better idea of what to do. | ||
672 | * | ||
673 | * Notes: | ||
674 | * This has the unfortunate side effect that if a shost adapter does | ||
675 | * not automatically request sense information, that we end up shutting | ||
676 | * it down before we request it. | ||
677 | * | ||
678 | * All drivers should request sense information internally these days, | ||
679 | * so for now all I have to say is tough noogies if you end up in here. | ||
680 | * | ||
681 | * XXX: Long term this code should go away, but that needs an audit of | ||
682 | * all LLDDs first. | ||
683 | **/ | ||
684 | static int scsi_eh_get_sense(struct list_head *work_q, | ||
685 | struct list_head *done_q) | ||
686 | { | ||
687 | struct list_head *lh, *lh_sf; | ||
688 | struct scsi_cmnd *scmd; | ||
689 | int rtn; | ||
690 | |||
691 | list_for_each_safe(lh, lh_sf, work_q) { | ||
692 | scmd = list_entry(lh, struct scsi_cmnd, eh_entry); | ||
693 | if (scsi_eh_eflags_chk(scmd, SCSI_EH_CANCEL_CMD) || | ||
694 | SCSI_SENSE_VALID(scmd)) | ||
695 | continue; | ||
696 | |||
697 | SCSI_LOG_ERROR_RECOVERY(2, printk("%s: requesting sense" | ||
698 | " for id: %d\n", | ||
699 | current->comm, | ||
700 | scmd->device->id)); | ||
701 | rtn = scsi_request_sense(scmd); | ||
702 | if (rtn != SUCCESS) | ||
703 | continue; | ||
704 | |||
705 | SCSI_LOG_ERROR_RECOVERY(3, printk("sense requested for %p" | ||
706 | " result %x\n", scmd, | ||
707 | scmd->result)); | ||
708 | SCSI_LOG_ERROR_RECOVERY(3, scsi_print_sense("bh", scmd)); | ||
709 | |||
710 | rtn = scsi_decide_disposition(scmd); | ||
711 | |||
712 | /* | ||
713 | * if the result was normal, then just pass it along to the | ||
714 | * upper level. | ||
715 | */ | ||
716 | if (rtn == SUCCESS) | ||
717 | /* we don't want this command reissued, just | ||
718 | * finished with the sense data, so set | ||
719 | * retries to the max allowed to ensure it | ||
720 | * won't get reissued */ | ||
721 | scmd->retries = scmd->allowed; | ||
722 | else if (rtn != NEEDS_RETRY) | ||
723 | continue; | ||
724 | |||
725 | scsi_eh_finish_cmd(scmd, done_q); | ||
726 | } | ||
727 | |||
728 | return list_empty(work_q); | ||
729 | } | ||
730 | |||
731 | /** | ||
732 | * scsi_try_to_abort_cmd - Ask host to abort a running command. | ||
733 | * @scmd: SCSI cmd to abort from Lower Level. | ||
734 | * | ||
735 | * Notes: | ||
736 | * This function will not return until the user's completion function | ||
737 | * has been called. there is no timeout on this operation. if the | ||
738 | * author of the low-level driver wishes this operation to be timed, | ||
739 | * they can provide this facility themselves. helper functions in | ||
740 | * scsi_error.c can be supplied to make this easier to do. | ||
741 | **/ | ||
742 | static int scsi_try_to_abort_cmd(struct scsi_cmnd *scmd) | ||
743 | { | ||
744 | unsigned long flags; | ||
745 | int rtn = FAILED; | ||
746 | |||
747 | if (!scmd->device->host->hostt->eh_abort_handler) | ||
748 | return rtn; | ||
749 | |||
750 | /* | ||
751 | * scsi_done was called just after the command timed out and before | ||
752 | * we had a chance to process it. (db) | ||
753 | */ | ||
754 | if (scmd->serial_number == 0) | ||
755 | return SUCCESS; | ||
756 | |||
757 | scmd->owner = SCSI_OWNER_LOWLEVEL; | ||
758 | |||
759 | spin_lock_irqsave(scmd->device->host->host_lock, flags); | ||
760 | rtn = scmd->device->host->hostt->eh_abort_handler(scmd); | ||
761 | spin_unlock_irqrestore(scmd->device->host->host_lock, flags); | ||
762 | |||
763 | return rtn; | ||
764 | } | ||
765 | |||
766 | /** | ||
767 | * scsi_eh_tur - Send TUR to device. | ||
768 | * @scmd: Scsi cmd to send TUR | ||
769 | * | ||
770 | * Return value: | ||
771 | * 0 - Device is ready. 1 - Device NOT ready. | ||
772 | **/ | ||
773 | static int scsi_eh_tur(struct scsi_cmnd *scmd) | ||
774 | { | ||
775 | static unsigned char tur_command[6] = {TEST_UNIT_READY, 0, 0, 0, 0, 0}; | ||
776 | int retry_cnt = 1, rtn; | ||
777 | |||
778 | retry_tur: | ||
779 | memcpy(scmd->cmnd, tur_command, sizeof(tur_command)); | ||
780 | |||
781 | /* | ||
782 | * zero the sense buffer. the scsi spec mandates that any | ||
783 | * untransferred sense data should be interpreted as being zero. | ||
784 | */ | ||
785 | memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer)); | ||
786 | |||
787 | scmd->request_buffer = NULL; | ||
788 | scmd->request_bufflen = 0; | ||
789 | scmd->use_sg = 0; | ||
790 | scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]); | ||
791 | scmd->underflow = 0; | ||
792 | scmd->sc_data_direction = DMA_NONE; | ||
793 | |||
794 | rtn = scsi_send_eh_cmnd(scmd, SENSE_TIMEOUT); | ||
795 | |||
796 | /* | ||
797 | * when we eventually call scsi_finish, we really wish to complete | ||
798 | * the original request, so let's restore the original data. (db) | ||
799 | */ | ||
800 | scsi_setup_cmd_retry(scmd); | ||
801 | |||
802 | /* | ||
803 | * hey, we are done. let's look to see what happened. | ||
804 | */ | ||
805 | SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n", | ||
806 | __FUNCTION__, scmd, rtn)); | ||
807 | if (rtn == SUCCESS) | ||
808 | return 0; | ||
809 | else if (rtn == NEEDS_RETRY) | ||
810 | if (retry_cnt--) | ||
811 | goto retry_tur; | ||
812 | return 1; | ||
813 | } | ||
814 | |||
815 | /** | ||
816 | * scsi_eh_abort_cmds - abort canceled commands. | ||
817 | * @shost: scsi host being recovered. | ||
818 | * @eh_done_q: list_head for processed commands. | ||
819 | * | ||
820 | * Decription: | ||
821 | * Try and see whether or not it makes sense to try and abort the | ||
822 | * running command. this only works out to be the case if we have one | ||
823 | * command that has timed out. if the command simply failed, it makes | ||
824 | * no sense to try and abort the command, since as far as the shost | ||
825 | * adapter is concerned, it isn't running. | ||
826 | **/ | ||
827 | static int scsi_eh_abort_cmds(struct list_head *work_q, | ||
828 | struct list_head *done_q) | ||
829 | { | ||
830 | struct list_head *lh, *lh_sf; | ||
831 | struct scsi_cmnd *scmd; | ||
832 | int rtn; | ||
833 | |||
834 | list_for_each_safe(lh, lh_sf, work_q) { | ||
835 | scmd = list_entry(lh, struct scsi_cmnd, eh_entry); | ||
836 | if (!scsi_eh_eflags_chk(scmd, SCSI_EH_CANCEL_CMD)) | ||
837 | continue; | ||
838 | SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting cmd:" | ||
839 | "0x%p\n", current->comm, | ||
840 | scmd)); | ||
841 | rtn = scsi_try_to_abort_cmd(scmd); | ||
842 | if (rtn == SUCCESS) { | ||
843 | scsi_eh_eflags_clr(scmd, SCSI_EH_CANCEL_CMD); | ||
844 | if (!scsi_device_online(scmd->device) || | ||
845 | !scsi_eh_tur(scmd)) { | ||
846 | scsi_eh_finish_cmd(scmd, done_q); | ||
847 | } | ||
848 | |||
849 | } else | ||
850 | SCSI_LOG_ERROR_RECOVERY(3, printk("%s: aborting" | ||
851 | " cmd failed:" | ||
852 | "0x%p\n", | ||
853 | current->comm, | ||
854 | scmd)); | ||
855 | } | ||
856 | |||
857 | return list_empty(work_q); | ||
858 | } | ||
859 | |||
860 | /** | ||
861 | * scsi_try_bus_device_reset - Ask host to perform a BDR on a dev | ||
862 | * @scmd: SCSI cmd used to send BDR | ||
863 | * | ||
864 | * Notes: | ||
865 | * There is no timeout for this operation. if this operation is | ||
866 | * unreliable for a given host, then the host itself needs to put a | ||
867 | * timer on it, and set the host back to a consistent state prior to | ||
868 | * returning. | ||
869 | **/ | ||
870 | static int scsi_try_bus_device_reset(struct scsi_cmnd *scmd) | ||
871 | { | ||
872 | unsigned long flags; | ||
873 | int rtn = FAILED; | ||
874 | |||
875 | if (!scmd->device->host->hostt->eh_device_reset_handler) | ||
876 | return rtn; | ||
877 | |||
878 | scmd->owner = SCSI_OWNER_LOWLEVEL; | ||
879 | |||
880 | spin_lock_irqsave(scmd->device->host->host_lock, flags); | ||
881 | rtn = scmd->device->host->hostt->eh_device_reset_handler(scmd); | ||
882 | spin_unlock_irqrestore(scmd->device->host->host_lock, flags); | ||
883 | |||
884 | if (rtn == SUCCESS) { | ||
885 | scmd->device->was_reset = 1; | ||
886 | scmd->device->expecting_cc_ua = 1; | ||
887 | } | ||
888 | |||
889 | return rtn; | ||
890 | } | ||
891 | |||
892 | /** | ||
893 | * scsi_eh_try_stu - Send START_UNIT to device. | ||
894 | * @scmd: Scsi cmd to send START_UNIT | ||
895 | * | ||
896 | * Return value: | ||
897 | * 0 - Device is ready. 1 - Device NOT ready. | ||
898 | **/ | ||
899 | static int scsi_eh_try_stu(struct scsi_cmnd *scmd) | ||
900 | { | ||
901 | static unsigned char stu_command[6] = {START_STOP, 0, 0, 0, 1, 0}; | ||
902 | int rtn; | ||
903 | |||
904 | if (!scmd->device->allow_restart) | ||
905 | return 1; | ||
906 | |||
907 | memcpy(scmd->cmnd, stu_command, sizeof(stu_command)); | ||
908 | |||
909 | /* | ||
910 | * zero the sense buffer. the scsi spec mandates that any | ||
911 | * untransferred sense data should be interpreted as being zero. | ||
912 | */ | ||
913 | memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer)); | ||
914 | |||
915 | scmd->request_buffer = NULL; | ||
916 | scmd->request_bufflen = 0; | ||
917 | scmd->use_sg = 0; | ||
918 | scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]); | ||
919 | scmd->underflow = 0; | ||
920 | scmd->sc_data_direction = DMA_NONE; | ||
921 | |||
922 | rtn = scsi_send_eh_cmnd(scmd, START_UNIT_TIMEOUT); | ||
923 | |||
924 | /* | ||
925 | * when we eventually call scsi_finish, we really wish to complete | ||
926 | * the original request, so let's restore the original data. (db) | ||
927 | */ | ||
928 | scsi_setup_cmd_retry(scmd); | ||
929 | |||
930 | /* | ||
931 | * hey, we are done. let's look to see what happened. | ||
932 | */ | ||
933 | SCSI_LOG_ERROR_RECOVERY(3, printk("%s: scmd %p rtn %x\n", | ||
934 | __FUNCTION__, scmd, rtn)); | ||
935 | if (rtn == SUCCESS) | ||
936 | return 0; | ||
937 | return 1; | ||
938 | } | ||
939 | |||
940 | /** | ||
941 | * scsi_eh_stu - send START_UNIT if needed | ||
942 | * @shost: scsi host being recovered. | ||
943 | * @eh_done_q: list_head for processed commands. | ||
944 | * | ||
945 | * Notes: | ||
946 | * If commands are failing due to not ready, initializing command required, | ||
947 | * try revalidating the device, which will end up sending a start unit. | ||
948 | **/ | ||
949 | static int scsi_eh_stu(struct Scsi_Host *shost, | ||
950 | struct list_head *work_q, | ||
951 | struct list_head *done_q) | ||
952 | { | ||
953 | struct list_head *lh, *lh_sf; | ||
954 | struct scsi_cmnd *scmd, *stu_scmd; | ||
955 | struct scsi_device *sdev; | ||
956 | |||
957 | shost_for_each_device(sdev, shost) { | ||
958 | stu_scmd = NULL; | ||
959 | list_for_each_entry(scmd, work_q, eh_entry) | ||
960 | if (scmd->device == sdev && SCSI_SENSE_VALID(scmd) && | ||
961 | scsi_check_sense(scmd) == FAILED ) { | ||
962 | stu_scmd = scmd; | ||
963 | break; | ||
964 | } | ||
965 | |||
966 | if (!stu_scmd) | ||
967 | continue; | ||
968 | |||
969 | SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending START_UNIT to sdev:" | ||
970 | " 0x%p\n", current->comm, sdev)); | ||
971 | |||
972 | if (!scsi_eh_try_stu(stu_scmd)) { | ||
973 | if (!scsi_device_online(sdev) || | ||
974 | !scsi_eh_tur(stu_scmd)) { | ||
975 | list_for_each_safe(lh, lh_sf, work_q) { | ||
976 | scmd = list_entry(lh, struct scsi_cmnd, eh_entry); | ||
977 | if (scmd->device == sdev) | ||
978 | scsi_eh_finish_cmd(scmd, done_q); | ||
979 | } | ||
980 | } | ||
981 | } else { | ||
982 | SCSI_LOG_ERROR_RECOVERY(3, | ||
983 | printk("%s: START_UNIT failed to sdev:" | ||
984 | " 0x%p\n", current->comm, sdev)); | ||
985 | } | ||
986 | } | ||
987 | |||
988 | return list_empty(work_q); | ||
989 | } | ||
990 | |||
991 | |||
992 | /** | ||
993 | * scsi_eh_bus_device_reset - send bdr if needed | ||
994 | * @shost: scsi host being recovered. | ||
995 | * @eh_done_q: list_head for processed commands. | ||
996 | * | ||
997 | * Notes: | ||
998 | * Try a bus device reset. still, look to see whether we have multiple | ||
999 | * devices that are jammed or not - if we have multiple devices, it | ||
1000 | * makes no sense to try bus_device_reset - we really would need to try | ||
1001 | * a bus_reset instead. | ||
1002 | **/ | ||
1003 | static int scsi_eh_bus_device_reset(struct Scsi_Host *shost, | ||
1004 | struct list_head *work_q, | ||
1005 | struct list_head *done_q) | ||
1006 | { | ||
1007 | struct list_head *lh, *lh_sf; | ||
1008 | struct scsi_cmnd *scmd, *bdr_scmd; | ||
1009 | struct scsi_device *sdev; | ||
1010 | int rtn; | ||
1011 | |||
1012 | shost_for_each_device(sdev, shost) { | ||
1013 | bdr_scmd = NULL; | ||
1014 | list_for_each_entry(scmd, work_q, eh_entry) | ||
1015 | if (scmd->device == sdev) { | ||
1016 | bdr_scmd = scmd; | ||
1017 | break; | ||
1018 | } | ||
1019 | |||
1020 | if (!bdr_scmd) | ||
1021 | continue; | ||
1022 | |||
1023 | SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BDR sdev:" | ||
1024 | " 0x%p\n", current->comm, | ||
1025 | sdev)); | ||
1026 | rtn = scsi_try_bus_device_reset(bdr_scmd); | ||
1027 | if (rtn == SUCCESS) { | ||
1028 | if (!scsi_device_online(sdev) || | ||
1029 | !scsi_eh_tur(bdr_scmd)) { | ||
1030 | list_for_each_safe(lh, lh_sf, | ||
1031 | work_q) { | ||
1032 | scmd = list_entry(lh, struct | ||
1033 | scsi_cmnd, | ||
1034 | eh_entry); | ||
1035 | if (scmd->device == sdev) | ||
1036 | scsi_eh_finish_cmd(scmd, | ||
1037 | done_q); | ||
1038 | } | ||
1039 | } | ||
1040 | } else { | ||
1041 | SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BDR" | ||
1042 | " failed sdev:" | ||
1043 | "0x%p\n", | ||
1044 | current->comm, | ||
1045 | sdev)); | ||
1046 | } | ||
1047 | } | ||
1048 | |||
1049 | return list_empty(work_q); | ||
1050 | } | ||
1051 | |||
1052 | /** | ||
1053 | * scsi_try_bus_reset - ask host to perform a bus reset | ||
1054 | * @scmd: SCSI cmd to send bus reset. | ||
1055 | **/ | ||
1056 | static int scsi_try_bus_reset(struct scsi_cmnd *scmd) | ||
1057 | { | ||
1058 | unsigned long flags; | ||
1059 | int rtn; | ||
1060 | |||
1061 | SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Bus RST\n", | ||
1062 | __FUNCTION__)); | ||
1063 | scmd->owner = SCSI_OWNER_LOWLEVEL; | ||
1064 | scmd->serial_number_at_timeout = scmd->serial_number; | ||
1065 | |||
1066 | if (!scmd->device->host->hostt->eh_bus_reset_handler) | ||
1067 | return FAILED; | ||
1068 | |||
1069 | spin_lock_irqsave(scmd->device->host->host_lock, flags); | ||
1070 | rtn = scmd->device->host->hostt->eh_bus_reset_handler(scmd); | ||
1071 | spin_unlock_irqrestore(scmd->device->host->host_lock, flags); | ||
1072 | |||
1073 | if (rtn == SUCCESS) { | ||
1074 | if (!scmd->device->host->hostt->skip_settle_delay) | ||
1075 | ssleep(BUS_RESET_SETTLE_TIME); | ||
1076 | spin_lock_irqsave(scmd->device->host->host_lock, flags); | ||
1077 | scsi_report_bus_reset(scmd->device->host, scmd->device->channel); | ||
1078 | spin_unlock_irqrestore(scmd->device->host->host_lock, flags); | ||
1079 | } | ||
1080 | |||
1081 | return rtn; | ||
1082 | } | ||
1083 | |||
1084 | /** | ||
1085 | * scsi_try_host_reset - ask host adapter to reset itself | ||
1086 | * @scmd: SCSI cmd to send hsot reset. | ||
1087 | **/ | ||
1088 | static int scsi_try_host_reset(struct scsi_cmnd *scmd) | ||
1089 | { | ||
1090 | unsigned long flags; | ||
1091 | int rtn; | ||
1092 | |||
1093 | SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Snd Host RST\n", | ||
1094 | __FUNCTION__)); | ||
1095 | scmd->owner = SCSI_OWNER_LOWLEVEL; | ||
1096 | scmd->serial_number_at_timeout = scmd->serial_number; | ||
1097 | |||
1098 | if (!scmd->device->host->hostt->eh_host_reset_handler) | ||
1099 | return FAILED; | ||
1100 | |||
1101 | spin_lock_irqsave(scmd->device->host->host_lock, flags); | ||
1102 | rtn = scmd->device->host->hostt->eh_host_reset_handler(scmd); | ||
1103 | spin_unlock_irqrestore(scmd->device->host->host_lock, flags); | ||
1104 | |||
1105 | if (rtn == SUCCESS) { | ||
1106 | if (!scmd->device->host->hostt->skip_settle_delay) | ||
1107 | ssleep(HOST_RESET_SETTLE_TIME); | ||
1108 | spin_lock_irqsave(scmd->device->host->host_lock, flags); | ||
1109 | scsi_report_bus_reset(scmd->device->host, scmd->device->channel); | ||
1110 | spin_unlock_irqrestore(scmd->device->host->host_lock, flags); | ||
1111 | } | ||
1112 | |||
1113 | return rtn; | ||
1114 | } | ||
1115 | |||
1116 | /** | ||
1117 | * scsi_eh_bus_reset - send a bus reset | ||
1118 | * @shost: scsi host being recovered. | ||
1119 | * @eh_done_q: list_head for processed commands. | ||
1120 | **/ | ||
1121 | static int scsi_eh_bus_reset(struct Scsi_Host *shost, | ||
1122 | struct list_head *work_q, | ||
1123 | struct list_head *done_q) | ||
1124 | { | ||
1125 | struct list_head *lh, *lh_sf; | ||
1126 | struct scsi_cmnd *scmd; | ||
1127 | struct scsi_cmnd *chan_scmd; | ||
1128 | unsigned int channel; | ||
1129 | int rtn; | ||
1130 | |||
1131 | /* | ||
1132 | * we really want to loop over the various channels, and do this on | ||
1133 | * a channel by channel basis. we should also check to see if any | ||
1134 | * of the failed commands are on soft_reset devices, and if so, skip | ||
1135 | * the reset. | ||
1136 | */ | ||
1137 | |||
1138 | for (channel = 0; channel <= shost->max_channel; channel++) { | ||
1139 | chan_scmd = NULL; | ||
1140 | list_for_each_entry(scmd, work_q, eh_entry) { | ||
1141 | if (channel == scmd->device->channel) { | ||
1142 | chan_scmd = scmd; | ||
1143 | break; | ||
1144 | /* | ||
1145 | * FIXME add back in some support for | ||
1146 | * soft_reset devices. | ||
1147 | */ | ||
1148 | } | ||
1149 | } | ||
1150 | |||
1151 | if (!chan_scmd) | ||
1152 | continue; | ||
1153 | SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending BRST chan:" | ||
1154 | " %d\n", current->comm, | ||
1155 | channel)); | ||
1156 | rtn = scsi_try_bus_reset(chan_scmd); | ||
1157 | if (rtn == SUCCESS) { | ||
1158 | list_for_each_safe(lh, lh_sf, work_q) { | ||
1159 | scmd = list_entry(lh, struct scsi_cmnd, | ||
1160 | eh_entry); | ||
1161 | if (channel == scmd->device->channel) | ||
1162 | if (!scsi_device_online(scmd->device) || | ||
1163 | !scsi_eh_tur(scmd)) | ||
1164 | scsi_eh_finish_cmd(scmd, | ||
1165 | done_q); | ||
1166 | } | ||
1167 | } else { | ||
1168 | SCSI_LOG_ERROR_RECOVERY(3, printk("%s: BRST" | ||
1169 | " failed chan: %d\n", | ||
1170 | current->comm, | ||
1171 | channel)); | ||
1172 | } | ||
1173 | } | ||
1174 | return list_empty(work_q); | ||
1175 | } | ||
1176 | |||
1177 | /** | ||
1178 | * scsi_eh_host_reset - send a host reset | ||
1179 | * @work_q: list_head for processed commands. | ||
1180 | * @done_q: list_head for processed commands. | ||
1181 | **/ | ||
1182 | static int scsi_eh_host_reset(struct list_head *work_q, | ||
1183 | struct list_head *done_q) | ||
1184 | { | ||
1185 | int rtn; | ||
1186 | struct list_head *lh, *lh_sf; | ||
1187 | struct scsi_cmnd *scmd; | ||
1188 | |||
1189 | if (!list_empty(work_q)) { | ||
1190 | scmd = list_entry(work_q->next, | ||
1191 | struct scsi_cmnd, eh_entry); | ||
1192 | |||
1193 | SCSI_LOG_ERROR_RECOVERY(3, printk("%s: Sending HRST\n" | ||
1194 | , current->comm)); | ||
1195 | |||
1196 | rtn = scsi_try_host_reset(scmd); | ||
1197 | if (rtn == SUCCESS) { | ||
1198 | list_for_each_safe(lh, lh_sf, work_q) { | ||
1199 | scmd = list_entry(lh, struct scsi_cmnd, eh_entry); | ||
1200 | if (!scsi_device_online(scmd->device) || | ||
1201 | (!scsi_eh_try_stu(scmd) && !scsi_eh_tur(scmd)) || | ||
1202 | !scsi_eh_tur(scmd)) | ||
1203 | scsi_eh_finish_cmd(scmd, done_q); | ||
1204 | } | ||
1205 | } else { | ||
1206 | SCSI_LOG_ERROR_RECOVERY(3, printk("%s: HRST" | ||
1207 | " failed\n", | ||
1208 | current->comm)); | ||
1209 | } | ||
1210 | } | ||
1211 | return list_empty(work_q); | ||
1212 | } | ||
1213 | |||
1214 | /** | ||
1215 | * scsi_eh_offline_sdevs - offline scsi devices that fail to recover | ||
1216 | * @work_q: list_head for processed commands. | ||
1217 | * @done_q: list_head for processed commands. | ||
1218 | * | ||
1219 | **/ | ||
1220 | static void scsi_eh_offline_sdevs(struct list_head *work_q, | ||
1221 | struct list_head *done_q) | ||
1222 | { | ||
1223 | struct list_head *lh, *lh_sf; | ||
1224 | struct scsi_cmnd *scmd; | ||
1225 | |||
1226 | list_for_each_safe(lh, lh_sf, work_q) { | ||
1227 | scmd = list_entry(lh, struct scsi_cmnd, eh_entry); | ||
1228 | printk(KERN_INFO "scsi: Device offlined - not" | ||
1229 | " ready after error recovery: host" | ||
1230 | " %d channel %d id %d lun %d\n", | ||
1231 | scmd->device->host->host_no, | ||
1232 | scmd->device->channel, | ||
1233 | scmd->device->id, | ||
1234 | scmd->device->lun); | ||
1235 | scsi_device_set_state(scmd->device, SDEV_OFFLINE); | ||
1236 | if (scsi_eh_eflags_chk(scmd, SCSI_EH_CANCEL_CMD)) { | ||
1237 | /* | ||
1238 | * FIXME: Handle lost cmds. | ||
1239 | */ | ||
1240 | } | ||
1241 | scsi_eh_finish_cmd(scmd, done_q); | ||
1242 | } | ||
1243 | return; | ||
1244 | } | ||
1245 | |||
1246 | /** | ||
1247 | * scsi_decide_disposition - Disposition a cmd on return from LLD. | ||
1248 | * @scmd: SCSI cmd to examine. | ||
1249 | * | ||
1250 | * Notes: | ||
1251 | * This is *only* called when we are examining the status after sending | ||
1252 | * out the actual data command. any commands that are queued for error | ||
1253 | * recovery (e.g. test_unit_ready) do *not* come through here. | ||
1254 | * | ||
1255 | * When this routine returns failed, it means the error handler thread | ||
1256 | * is woken. In cases where the error code indicates an error that | ||
1257 | * doesn't require the error handler read (i.e. we don't need to | ||
1258 | * abort/reset), this function should return SUCCESS. | ||
1259 | **/ | ||
1260 | int scsi_decide_disposition(struct scsi_cmnd *scmd) | ||
1261 | { | ||
1262 | int rtn; | ||
1263 | |||
1264 | /* | ||
1265 | * if the device is offline, then we clearly just pass the result back | ||
1266 | * up to the top level. | ||
1267 | */ | ||
1268 | if (!scsi_device_online(scmd->device)) { | ||
1269 | SCSI_LOG_ERROR_RECOVERY(5, printk("%s: device offline - report" | ||
1270 | " as SUCCESS\n", | ||
1271 | __FUNCTION__)); | ||
1272 | return SUCCESS; | ||
1273 | } | ||
1274 | |||
1275 | /* | ||
1276 | * first check the host byte, to see if there is anything in there | ||
1277 | * that would indicate what we need to do. | ||
1278 | */ | ||
1279 | switch (host_byte(scmd->result)) { | ||
1280 | case DID_PASSTHROUGH: | ||
1281 | /* | ||
1282 | * no matter what, pass this through to the upper layer. | ||
1283 | * nuke this special code so that it looks like we are saying | ||
1284 | * did_ok. | ||
1285 | */ | ||
1286 | scmd->result &= 0xff00ffff; | ||
1287 | return SUCCESS; | ||
1288 | case DID_OK: | ||
1289 | /* | ||
1290 | * looks good. drop through, and check the next byte. | ||
1291 | */ | ||
1292 | break; | ||
1293 | case DID_NO_CONNECT: | ||
1294 | case DID_BAD_TARGET: | ||
1295 | case DID_ABORT: | ||
1296 | /* | ||
1297 | * note - this means that we just report the status back | ||
1298 | * to the top level driver, not that we actually think | ||
1299 | * that it indicates SUCCESS. | ||
1300 | */ | ||
1301 | return SUCCESS; | ||
1302 | /* | ||
1303 | * when the low level driver returns did_soft_error, | ||
1304 | * it is responsible for keeping an internal retry counter | ||
1305 | * in order to avoid endless loops (db) | ||
1306 | * | ||
1307 | * actually this is a bug in this function here. we should | ||
1308 | * be mindful of the maximum number of retries specified | ||
1309 | * and not get stuck in a loop. | ||
1310 | */ | ||
1311 | case DID_SOFT_ERROR: | ||
1312 | goto maybe_retry; | ||
1313 | case DID_IMM_RETRY: | ||
1314 | return NEEDS_RETRY; | ||
1315 | |||
1316 | case DID_ERROR: | ||
1317 | if (msg_byte(scmd->result) == COMMAND_COMPLETE && | ||
1318 | status_byte(scmd->result) == RESERVATION_CONFLICT) | ||
1319 | /* | ||
1320 | * execute reservation conflict processing code | ||
1321 | * lower down | ||
1322 | */ | ||
1323 | break; | ||
1324 | /* fallthrough */ | ||
1325 | |||
1326 | case DID_BUS_BUSY: | ||
1327 | case DID_PARITY: | ||
1328 | goto maybe_retry; | ||
1329 | case DID_TIME_OUT: | ||
1330 | /* | ||
1331 | * when we scan the bus, we get timeout messages for | ||
1332 | * these commands if there is no device available. | ||
1333 | * other hosts report did_no_connect for the same thing. | ||
1334 | */ | ||
1335 | if ((scmd->cmnd[0] == TEST_UNIT_READY || | ||
1336 | scmd->cmnd[0] == INQUIRY)) { | ||
1337 | return SUCCESS; | ||
1338 | } else { | ||
1339 | return FAILED; | ||
1340 | } | ||
1341 | case DID_RESET: | ||
1342 | return SUCCESS; | ||
1343 | default: | ||
1344 | return FAILED; | ||
1345 | } | ||
1346 | |||
1347 | /* | ||
1348 | * next, check the message byte. | ||
1349 | */ | ||
1350 | if (msg_byte(scmd->result) != COMMAND_COMPLETE) | ||
1351 | return FAILED; | ||
1352 | |||
1353 | /* | ||
1354 | * check the status byte to see if this indicates anything special. | ||
1355 | */ | ||
1356 | switch (status_byte(scmd->result)) { | ||
1357 | case QUEUE_FULL: | ||
1358 | /* | ||
1359 | * the case of trying to send too many commands to a | ||
1360 | * tagged queueing device. | ||
1361 | */ | ||
1362 | case BUSY: | ||
1363 | /* | ||
1364 | * device can't talk to us at the moment. Should only | ||
1365 | * occur (SAM-3) when the task queue is empty, so will cause | ||
1366 | * the empty queue handling to trigger a stall in the | ||
1367 | * device. | ||
1368 | */ | ||
1369 | return ADD_TO_MLQUEUE; | ||
1370 | case GOOD: | ||
1371 | case COMMAND_TERMINATED: | ||
1372 | case TASK_ABORTED: | ||
1373 | return SUCCESS; | ||
1374 | case CHECK_CONDITION: | ||
1375 | rtn = scsi_check_sense(scmd); | ||
1376 | if (rtn == NEEDS_RETRY) | ||
1377 | goto maybe_retry; | ||
1378 | /* if rtn == FAILED, we have no sense information; | ||
1379 | * returning FAILED will wake the error handler thread | ||
1380 | * to collect the sense and redo the decide | ||
1381 | * disposition */ | ||
1382 | return rtn; | ||
1383 | case CONDITION_GOOD: | ||
1384 | case INTERMEDIATE_GOOD: | ||
1385 | case INTERMEDIATE_C_GOOD: | ||
1386 | case ACA_ACTIVE: | ||
1387 | /* | ||
1388 | * who knows? FIXME(eric) | ||
1389 | */ | ||
1390 | return SUCCESS; | ||
1391 | |||
1392 | case RESERVATION_CONFLICT: | ||
1393 | printk(KERN_INFO "scsi: reservation conflict: host" | ||
1394 | " %d channel %d id %d lun %d\n", | ||
1395 | scmd->device->host->host_no, scmd->device->channel, | ||
1396 | scmd->device->id, scmd->device->lun); | ||
1397 | return SUCCESS; /* causes immediate i/o error */ | ||
1398 | default: | ||
1399 | return FAILED; | ||
1400 | } | ||
1401 | return FAILED; | ||
1402 | |||
1403 | maybe_retry: | ||
1404 | |||
1405 | /* we requeue for retry because the error was retryable, and | ||
1406 | * the request was not marked fast fail. Note that above, | ||
1407 | * even if the request is marked fast fail, we still requeue | ||
1408 | * for queue congestion conditions (QUEUE_FULL or BUSY) */ | ||
1409 | if ((++scmd->retries) < scmd->allowed | ||
1410 | && !blk_noretry_request(scmd->request)) { | ||
1411 | return NEEDS_RETRY; | ||
1412 | } else { | ||
1413 | /* | ||
1414 | * no more retries - report this one back to upper level. | ||
1415 | */ | ||
1416 | return SUCCESS; | ||
1417 | } | ||
1418 | } | ||
1419 | |||
1420 | /** | ||
1421 | * scsi_eh_lock_done - done function for eh door lock request | ||
1422 | * @scmd: SCSI command block for the door lock request | ||
1423 | * | ||
1424 | * Notes: | ||
1425 | * We completed the asynchronous door lock request, and it has either | ||
1426 | * locked the door or failed. We must free the command structures | ||
1427 | * associated with this request. | ||
1428 | **/ | ||
1429 | static void scsi_eh_lock_done(struct scsi_cmnd *scmd) | ||
1430 | { | ||
1431 | struct scsi_request *sreq = scmd->sc_request; | ||
1432 | |||
1433 | scsi_release_request(sreq); | ||
1434 | } | ||
1435 | |||
1436 | |||
1437 | /** | ||
1438 | * scsi_eh_lock_door - Prevent medium removal for the specified device | ||
1439 | * @sdev: SCSI device to prevent medium removal | ||
1440 | * | ||
1441 | * Locking: | ||
1442 | * We must be called from process context; scsi_allocate_request() | ||
1443 | * may sleep. | ||
1444 | * | ||
1445 | * Notes: | ||
1446 | * We queue up an asynchronous "ALLOW MEDIUM REMOVAL" request on the | ||
1447 | * head of the devices request queue, and continue. | ||
1448 | * | ||
1449 | * Bugs: | ||
1450 | * scsi_allocate_request() may sleep waiting for existing requests to | ||
1451 | * be processed. However, since we haven't kicked off any request | ||
1452 | * processing for this host, this may deadlock. | ||
1453 | * | ||
1454 | * If scsi_allocate_request() fails for what ever reason, we | ||
1455 | * completely forget to lock the door. | ||
1456 | **/ | ||
1457 | static void scsi_eh_lock_door(struct scsi_device *sdev) | ||
1458 | { | ||
1459 | struct scsi_request *sreq = scsi_allocate_request(sdev, GFP_KERNEL); | ||
1460 | |||
1461 | if (unlikely(!sreq)) { | ||
1462 | printk(KERN_ERR "%s: request allocate failed," | ||
1463 | "prevent media removal cmd not sent\n", __FUNCTION__); | ||
1464 | return; | ||
1465 | } | ||
1466 | |||
1467 | sreq->sr_cmnd[0] = ALLOW_MEDIUM_REMOVAL; | ||
1468 | sreq->sr_cmnd[1] = 0; | ||
1469 | sreq->sr_cmnd[2] = 0; | ||
1470 | sreq->sr_cmnd[3] = 0; | ||
1471 | sreq->sr_cmnd[4] = SCSI_REMOVAL_PREVENT; | ||
1472 | sreq->sr_cmnd[5] = 0; | ||
1473 | sreq->sr_data_direction = DMA_NONE; | ||
1474 | sreq->sr_bufflen = 0; | ||
1475 | sreq->sr_buffer = NULL; | ||
1476 | sreq->sr_allowed = 5; | ||
1477 | sreq->sr_done = scsi_eh_lock_done; | ||
1478 | sreq->sr_timeout_per_command = 10 * HZ; | ||
1479 | sreq->sr_cmd_len = COMMAND_SIZE(sreq->sr_cmnd[0]); | ||
1480 | |||
1481 | scsi_insert_special_req(sreq, 1); | ||
1482 | } | ||
1483 | |||
1484 | |||
1485 | /** | ||
1486 | * scsi_restart_operations - restart io operations to the specified host. | ||
1487 | * @shost: Host we are restarting. | ||
1488 | * | ||
1489 | * Notes: | ||
1490 | * When we entered the error handler, we blocked all further i/o to | ||
1491 | * this device. we need to 'reverse' this process. | ||
1492 | **/ | ||
1493 | static void scsi_restart_operations(struct Scsi_Host *shost) | ||
1494 | { | ||
1495 | struct scsi_device *sdev; | ||
1496 | |||
1497 | /* | ||
1498 | * If the door was locked, we need to insert a door lock request | ||
1499 | * onto the head of the SCSI request queue for the device. There | ||
1500 | * is no point trying to lock the door of an off-line device. | ||
1501 | */ | ||
1502 | shost_for_each_device(sdev, shost) { | ||
1503 | if (scsi_device_online(sdev) && sdev->locked) | ||
1504 | scsi_eh_lock_door(sdev); | ||
1505 | } | ||
1506 | |||
1507 | /* | ||
1508 | * next free up anything directly waiting upon the host. this | ||
1509 | * will be requests for character device operations, and also for | ||
1510 | * ioctls to queued block devices. | ||
1511 | */ | ||
1512 | SCSI_LOG_ERROR_RECOVERY(3, printk("%s: waking up host to restart\n", | ||
1513 | __FUNCTION__)); | ||
1514 | |||
1515 | clear_bit(SHOST_RECOVERY, &shost->shost_state); | ||
1516 | |||
1517 | wake_up(&shost->host_wait); | ||
1518 | |||
1519 | /* | ||
1520 | * finally we need to re-initiate requests that may be pending. we will | ||
1521 | * have had everything blocked while error handling is taking place, and | ||
1522 | * now that error recovery is done, we will need to ensure that these | ||
1523 | * requests are started. | ||
1524 | */ | ||
1525 | scsi_run_host_queues(shost); | ||
1526 | } | ||
1527 | |||
1528 | /** | ||
1529 | * scsi_eh_ready_devs - check device ready state and recover if not. | ||
1530 | * @shost: host to be recovered. | ||
1531 | * @eh_done_q: list_head for processed commands. | ||
1532 | * | ||
1533 | **/ | ||
1534 | static void scsi_eh_ready_devs(struct Scsi_Host *shost, | ||
1535 | struct list_head *work_q, | ||
1536 | struct list_head *done_q) | ||
1537 | { | ||
1538 | if (!scsi_eh_stu(shost, work_q, done_q)) | ||
1539 | if (!scsi_eh_bus_device_reset(shost, work_q, done_q)) | ||
1540 | if (!scsi_eh_bus_reset(shost, work_q, done_q)) | ||
1541 | if (!scsi_eh_host_reset(work_q, done_q)) | ||
1542 | scsi_eh_offline_sdevs(work_q, done_q); | ||
1543 | } | ||
1544 | |||
1545 | /** | ||
1546 | * scsi_eh_flush_done_q - finish processed commands or retry them. | ||
1547 | * @done_q: list_head of processed commands. | ||
1548 | * | ||
1549 | **/ | ||
1550 | static void scsi_eh_flush_done_q(struct list_head *done_q) | ||
1551 | { | ||
1552 | struct list_head *lh, *lh_sf; | ||
1553 | struct scsi_cmnd *scmd; | ||
1554 | |||
1555 | list_for_each_safe(lh, lh_sf, done_q) { | ||
1556 | scmd = list_entry(lh, struct scsi_cmnd, eh_entry); | ||
1557 | list_del_init(lh); | ||
1558 | if (scsi_device_online(scmd->device) && | ||
1559 | !blk_noretry_request(scmd->request) && | ||
1560 | (++scmd->retries < scmd->allowed)) { | ||
1561 | SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush" | ||
1562 | " retry cmd: %p\n", | ||
1563 | current->comm, | ||
1564 | scmd)); | ||
1565 | scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY); | ||
1566 | } else { | ||
1567 | if (!scmd->result) | ||
1568 | scmd->result |= (DRIVER_TIMEOUT << 24); | ||
1569 | SCSI_LOG_ERROR_RECOVERY(3, printk("%s: flush finish" | ||
1570 | " cmd: %p\n", | ||
1571 | current->comm, scmd)); | ||
1572 | scsi_finish_command(scmd); | ||
1573 | } | ||
1574 | } | ||
1575 | } | ||
1576 | |||
1577 | /** | ||
1578 | * scsi_unjam_host - Attempt to fix a host which has a cmd that failed. | ||
1579 | * @shost: Host to unjam. | ||
1580 | * | ||
1581 | * Notes: | ||
1582 | * When we come in here, we *know* that all commands on the bus have | ||
1583 | * either completed, failed or timed out. we also know that no further | ||
1584 | * commands are being sent to the host, so things are relatively quiet | ||
1585 | * and we have freedom to fiddle with things as we wish. | ||
1586 | * | ||
1587 | * This is only the *default* implementation. it is possible for | ||
1588 | * individual drivers to supply their own version of this function, and | ||
1589 | * if the maintainer wishes to do this, it is strongly suggested that | ||
1590 | * this function be taken as a template and modified. this function | ||
1591 | * was designed to correctly handle problems for about 95% of the | ||
1592 | * different cases out there, and it should always provide at least a | ||
1593 | * reasonable amount of error recovery. | ||
1594 | * | ||
1595 | * Any command marked 'failed' or 'timeout' must eventually have | ||
1596 | * scsi_finish_cmd() called for it. we do all of the retry stuff | ||
1597 | * here, so when we restart the host after we return it should have an | ||
1598 | * empty queue. | ||
1599 | **/ | ||
1600 | static void scsi_unjam_host(struct Scsi_Host *shost) | ||
1601 | { | ||
1602 | unsigned long flags; | ||
1603 | LIST_HEAD(eh_work_q); | ||
1604 | LIST_HEAD(eh_done_q); | ||
1605 | |||
1606 | spin_lock_irqsave(shost->host_lock, flags); | ||
1607 | list_splice_init(&shost->eh_cmd_q, &eh_work_q); | ||
1608 | spin_unlock_irqrestore(shost->host_lock, flags); | ||
1609 | |||
1610 | SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(shost, &eh_work_q)); | ||
1611 | |||
1612 | if (!scsi_eh_get_sense(&eh_work_q, &eh_done_q)) | ||
1613 | if (!scsi_eh_abort_cmds(&eh_work_q, &eh_done_q)) | ||
1614 | scsi_eh_ready_devs(shost, &eh_work_q, &eh_done_q); | ||
1615 | |||
1616 | scsi_eh_flush_done_q(&eh_done_q); | ||
1617 | } | ||
1618 | |||
1619 | /** | ||
1620 | * scsi_error_handler - Handle errors/timeouts of SCSI cmds. | ||
1621 | * @data: Host for which we are running. | ||
1622 | * | ||
1623 | * Notes: | ||
1624 | * This is always run in the context of a kernel thread. The idea is | ||
1625 | * that we start this thing up when the kernel starts up (one per host | ||
1626 | * that we detect), and it immediately goes to sleep and waits for some | ||
1627 | * event (i.e. failure). When this takes place, we have the job of | ||
1628 | * trying to unjam the bus and restarting things. | ||
1629 | **/ | ||
1630 | int scsi_error_handler(void *data) | ||
1631 | { | ||
1632 | struct Scsi_Host *shost = (struct Scsi_Host *) data; | ||
1633 | int rtn; | ||
1634 | DECLARE_MUTEX_LOCKED(sem); | ||
1635 | |||
1636 | /* | ||
1637 | * Flush resources | ||
1638 | */ | ||
1639 | |||
1640 | daemonize("scsi_eh_%d", shost->host_no); | ||
1641 | |||
1642 | current->flags |= PF_NOFREEZE; | ||
1643 | |||
1644 | shost->eh_wait = &sem; | ||
1645 | shost->ehandler = current; | ||
1646 | |||
1647 | /* | ||
1648 | * Wake up the thread that created us. | ||
1649 | */ | ||
1650 | SCSI_LOG_ERROR_RECOVERY(3, printk("Wake up parent of" | ||
1651 | " scsi_eh_%d\n",shost->host_no)); | ||
1652 | |||
1653 | complete(shost->eh_notify); | ||
1654 | |||
1655 | while (1) { | ||
1656 | /* | ||
1657 | * If we get a signal, it means we are supposed to go | ||
1658 | * away and die. This typically happens if the user is | ||
1659 | * trying to unload a module. | ||
1660 | */ | ||
1661 | SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler" | ||
1662 | " scsi_eh_%d" | ||
1663 | " sleeping\n",shost->host_no)); | ||
1664 | |||
1665 | /* | ||
1666 | * Note - we always use down_interruptible with the semaphore | ||
1667 | * even if the module was loaded as part of the kernel. The | ||
1668 | * reason is that down() will cause this thread to be counted | ||
1669 | * in the load average as a running process, and down | ||
1670 | * interruptible doesn't. Given that we need to allow this | ||
1671 | * thread to die if the driver was loaded as a module, using | ||
1672 | * semaphores isn't unreasonable. | ||
1673 | */ | ||
1674 | down_interruptible(&sem); | ||
1675 | if (shost->eh_kill) | ||
1676 | break; | ||
1677 | |||
1678 | SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler" | ||
1679 | " scsi_eh_%d waking" | ||
1680 | " up\n",shost->host_no)); | ||
1681 | |||
1682 | shost->eh_active = 1; | ||
1683 | |||
1684 | /* | ||
1685 | * We have a host that is failing for some reason. Figure out | ||
1686 | * what we need to do to get it up and online again (if we can). | ||
1687 | * If we fail, we end up taking the thing offline. | ||
1688 | */ | ||
1689 | if (shost->hostt->eh_strategy_handler) | ||
1690 | rtn = shost->hostt->eh_strategy_handler(shost); | ||
1691 | else | ||
1692 | scsi_unjam_host(shost); | ||
1693 | |||
1694 | shost->eh_active = 0; | ||
1695 | |||
1696 | /* | ||
1697 | * Note - if the above fails completely, the action is to take | ||
1698 | * individual devices offline and flush the queue of any | ||
1699 | * outstanding requests that may have been pending. When we | ||
1700 | * restart, we restart any I/O to any other devices on the bus | ||
1701 | * which are still online. | ||
1702 | */ | ||
1703 | scsi_restart_operations(shost); | ||
1704 | |||
1705 | } | ||
1706 | |||
1707 | SCSI_LOG_ERROR_RECOVERY(1, printk("Error handler scsi_eh_%d" | ||
1708 | " exiting\n",shost->host_no)); | ||
1709 | |||
1710 | /* | ||
1711 | * Make sure that nobody tries to wake us up again. | ||
1712 | */ | ||
1713 | shost->eh_wait = NULL; | ||
1714 | |||
1715 | /* | ||
1716 | * Knock this down too. From this point on, the host is flying | ||
1717 | * without a pilot. If this is because the module is being unloaded, | ||
1718 | * that's fine. If the user sent a signal to this thing, we are | ||
1719 | * potentially in real danger. | ||
1720 | */ | ||
1721 | shost->eh_active = 0; | ||
1722 | shost->ehandler = NULL; | ||
1723 | |||
1724 | /* | ||
1725 | * If anyone is waiting for us to exit (i.e. someone trying to unload | ||
1726 | * a driver), then wake up that process to let them know we are on | ||
1727 | * the way out the door. | ||
1728 | */ | ||
1729 | complete_and_exit(shost->eh_notify, 0); | ||
1730 | return 0; | ||
1731 | } | ||
1732 | |||
1733 | /* | ||
1734 | * Function: scsi_report_bus_reset() | ||
1735 | * | ||
1736 | * Purpose: Utility function used by low-level drivers to report that | ||
1737 | * they have observed a bus reset on the bus being handled. | ||
1738 | * | ||
1739 | * Arguments: shost - Host in question | ||
1740 | * channel - channel on which reset was observed. | ||
1741 | * | ||
1742 | * Returns: Nothing | ||
1743 | * | ||
1744 | * Lock status: Host lock must be held. | ||
1745 | * | ||
1746 | * Notes: This only needs to be called if the reset is one which | ||
1747 | * originates from an unknown location. Resets originated | ||
1748 | * by the mid-level itself don't need to call this, but there | ||
1749 | * should be no harm. | ||
1750 | * | ||
1751 | * The main purpose of this is to make sure that a CHECK_CONDITION | ||
1752 | * is properly treated. | ||
1753 | */ | ||
1754 | void scsi_report_bus_reset(struct Scsi_Host *shost, int channel) | ||
1755 | { | ||
1756 | struct scsi_device *sdev; | ||
1757 | |||
1758 | __shost_for_each_device(sdev, shost) { | ||
1759 | if (channel == sdev->channel) { | ||
1760 | sdev->was_reset = 1; | ||
1761 | sdev->expecting_cc_ua = 1; | ||
1762 | } | ||
1763 | } | ||
1764 | } | ||
1765 | EXPORT_SYMBOL(scsi_report_bus_reset); | ||
1766 | |||
1767 | /* | ||
1768 | * Function: scsi_report_device_reset() | ||
1769 | * | ||
1770 | * Purpose: Utility function used by low-level drivers to report that | ||
1771 | * they have observed a device reset on the device being handled. | ||
1772 | * | ||
1773 | * Arguments: shost - Host in question | ||
1774 | * channel - channel on which reset was observed | ||
1775 | * target - target on which reset was observed | ||
1776 | * | ||
1777 | * Returns: Nothing | ||
1778 | * | ||
1779 | * Lock status: Host lock must be held | ||
1780 | * | ||
1781 | * Notes: This only needs to be called if the reset is one which | ||
1782 | * originates from an unknown location. Resets originated | ||
1783 | * by the mid-level itself don't need to call this, but there | ||
1784 | * should be no harm. | ||
1785 | * | ||
1786 | * The main purpose of this is to make sure that a CHECK_CONDITION | ||
1787 | * is properly treated. | ||
1788 | */ | ||
1789 | void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target) | ||
1790 | { | ||
1791 | struct scsi_device *sdev; | ||
1792 | |||
1793 | __shost_for_each_device(sdev, shost) { | ||
1794 | if (channel == sdev->channel && | ||
1795 | target == sdev->id) { | ||
1796 | sdev->was_reset = 1; | ||
1797 | sdev->expecting_cc_ua = 1; | ||
1798 | } | ||
1799 | } | ||
1800 | } | ||
1801 | EXPORT_SYMBOL(scsi_report_device_reset); | ||
1802 | |||
1803 | static void | ||
1804 | scsi_reset_provider_done_command(struct scsi_cmnd *scmd) | ||
1805 | { | ||
1806 | } | ||
1807 | |||
1808 | /* | ||
1809 | * Function: scsi_reset_provider | ||
1810 | * | ||
1811 | * Purpose: Send requested reset to a bus or device at any phase. | ||
1812 | * | ||
1813 | * Arguments: device - device to send reset to | ||
1814 | * flag - reset type (see scsi.h) | ||
1815 | * | ||
1816 | * Returns: SUCCESS/FAILURE. | ||
1817 | * | ||
1818 | * Notes: This is used by the SCSI Generic driver to provide | ||
1819 | * Bus/Device reset capability. | ||
1820 | */ | ||
1821 | int | ||
1822 | scsi_reset_provider(struct scsi_device *dev, int flag) | ||
1823 | { | ||
1824 | struct scsi_cmnd *scmd = scsi_get_command(dev, GFP_KERNEL); | ||
1825 | struct request req; | ||
1826 | int rtn; | ||
1827 | |||
1828 | scmd->request = &req; | ||
1829 | memset(&scmd->eh_timeout, 0, sizeof(scmd->eh_timeout)); | ||
1830 | scmd->request->rq_status = RQ_SCSI_BUSY; | ||
1831 | scmd->state = SCSI_STATE_INITIALIZING; | ||
1832 | scmd->owner = SCSI_OWNER_MIDLEVEL; | ||
1833 | |||
1834 | memset(&scmd->cmnd, '\0', sizeof(scmd->cmnd)); | ||
1835 | |||
1836 | scmd->scsi_done = scsi_reset_provider_done_command; | ||
1837 | scmd->done = NULL; | ||
1838 | scmd->buffer = NULL; | ||
1839 | scmd->bufflen = 0; | ||
1840 | scmd->request_buffer = NULL; | ||
1841 | scmd->request_bufflen = 0; | ||
1842 | scmd->internal_timeout = NORMAL_TIMEOUT; | ||
1843 | scmd->abort_reason = DID_ABORT; | ||
1844 | |||
1845 | scmd->cmd_len = 0; | ||
1846 | |||
1847 | scmd->sc_data_direction = DMA_BIDIRECTIONAL; | ||
1848 | scmd->sc_request = NULL; | ||
1849 | scmd->sc_magic = SCSI_CMND_MAGIC; | ||
1850 | |||
1851 | init_timer(&scmd->eh_timeout); | ||
1852 | |||
1853 | /* | ||
1854 | * Sometimes the command can get back into the timer chain, | ||
1855 | * so use the pid as an identifier. | ||
1856 | */ | ||
1857 | scmd->pid = 0; | ||
1858 | |||
1859 | switch (flag) { | ||
1860 | case SCSI_TRY_RESET_DEVICE: | ||
1861 | rtn = scsi_try_bus_device_reset(scmd); | ||
1862 | if (rtn == SUCCESS) | ||
1863 | break; | ||
1864 | /* FALLTHROUGH */ | ||
1865 | case SCSI_TRY_RESET_BUS: | ||
1866 | rtn = scsi_try_bus_reset(scmd); | ||
1867 | if (rtn == SUCCESS) | ||
1868 | break; | ||
1869 | /* FALLTHROUGH */ | ||
1870 | case SCSI_TRY_RESET_HOST: | ||
1871 | rtn = scsi_try_host_reset(scmd); | ||
1872 | break; | ||
1873 | default: | ||
1874 | rtn = FAILED; | ||
1875 | } | ||
1876 | |||
1877 | scsi_delete_timer(scmd); | ||
1878 | scsi_next_command(scmd); | ||
1879 | return rtn; | ||
1880 | } | ||
1881 | EXPORT_SYMBOL(scsi_reset_provider); | ||
1882 | |||
1883 | /** | ||
1884 | * scsi_normalize_sense - normalize main elements from either fixed or | ||
1885 | * descriptor sense data format into a common format. | ||
1886 | * | ||
1887 | * @sense_buffer: byte array containing sense data returned by device | ||
1888 | * @sb_len: number of valid bytes in sense_buffer | ||
1889 | * @sshdr: pointer to instance of structure that common | ||
1890 | * elements are written to. | ||
1891 | * | ||
1892 | * Notes: | ||
1893 | * The "main elements" from sense data are: response_code, sense_key, | ||
1894 | * asc, ascq and additional_length (only for descriptor format). | ||
1895 | * | ||
1896 | * Typically this function can be called after a device has | ||
1897 | * responded to a SCSI command with the CHECK_CONDITION status. | ||
1898 | * | ||
1899 | * Return value: | ||
1900 | * 1 if valid sense data information found, else 0; | ||
1901 | **/ | ||
1902 | int scsi_normalize_sense(const u8 *sense_buffer, int sb_len, | ||
1903 | struct scsi_sense_hdr *sshdr) | ||
1904 | { | ||
1905 | if (!sense_buffer || !sb_len || (sense_buffer[0] & 0x70) != 0x70) | ||
1906 | return 0; | ||
1907 | |||
1908 | memset(sshdr, 0, sizeof(struct scsi_sense_hdr)); | ||
1909 | |||
1910 | sshdr->response_code = (sense_buffer[0] & 0x7f); | ||
1911 | if (sshdr->response_code >= 0x72) { | ||
1912 | /* | ||
1913 | * descriptor format | ||
1914 | */ | ||
1915 | if (sb_len > 1) | ||
1916 | sshdr->sense_key = (sense_buffer[1] & 0xf); | ||
1917 | if (sb_len > 2) | ||
1918 | sshdr->asc = sense_buffer[2]; | ||
1919 | if (sb_len > 3) | ||
1920 | sshdr->ascq = sense_buffer[3]; | ||
1921 | if (sb_len > 7) | ||
1922 | sshdr->additional_length = sense_buffer[7]; | ||
1923 | } else { | ||
1924 | /* | ||
1925 | * fixed format | ||
1926 | */ | ||
1927 | if (sb_len > 2) | ||
1928 | sshdr->sense_key = (sense_buffer[2] & 0xf); | ||
1929 | if (sb_len > 7) { | ||
1930 | sb_len = (sb_len < (sense_buffer[7] + 8)) ? | ||
1931 | sb_len : (sense_buffer[7] + 8); | ||
1932 | if (sb_len > 12) | ||
1933 | sshdr->asc = sense_buffer[12]; | ||
1934 | if (sb_len > 13) | ||
1935 | sshdr->ascq = sense_buffer[13]; | ||
1936 | } | ||
1937 | } | ||
1938 | |||
1939 | return 1; | ||
1940 | } | ||
1941 | EXPORT_SYMBOL(scsi_normalize_sense); | ||
1942 | |||
1943 | int scsi_request_normalize_sense(struct scsi_request *sreq, | ||
1944 | struct scsi_sense_hdr *sshdr) | ||
1945 | { | ||
1946 | return scsi_normalize_sense(sreq->sr_sense_buffer, | ||
1947 | sizeof(sreq->sr_sense_buffer), sshdr); | ||
1948 | } | ||
1949 | EXPORT_SYMBOL(scsi_request_normalize_sense); | ||
1950 | |||
1951 | int scsi_command_normalize_sense(struct scsi_cmnd *cmd, | ||
1952 | struct scsi_sense_hdr *sshdr) | ||
1953 | { | ||
1954 | return scsi_normalize_sense(cmd->sense_buffer, | ||
1955 | sizeof(cmd->sense_buffer), sshdr); | ||
1956 | } | ||
1957 | EXPORT_SYMBOL(scsi_command_normalize_sense); | ||
1958 | |||
1959 | /** | ||
1960 | * scsi_sense_desc_find - search for a given descriptor type in | ||
1961 | * descriptor sense data format. | ||
1962 | * | ||
1963 | * @sense_buffer: byte array of descriptor format sense data | ||
1964 | * @sb_len: number of valid bytes in sense_buffer | ||
1965 | * @desc_type: value of descriptor type to find | ||
1966 | * (e.g. 0 -> information) | ||
1967 | * | ||
1968 | * Notes: | ||
1969 | * only valid when sense data is in descriptor format | ||
1970 | * | ||
1971 | * Return value: | ||
1972 | * pointer to start of (first) descriptor if found else NULL | ||
1973 | **/ | ||
1974 | const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len, | ||
1975 | int desc_type) | ||
1976 | { | ||
1977 | int add_sen_len, add_len, desc_len, k; | ||
1978 | const u8 * descp; | ||
1979 | |||
1980 | if ((sb_len < 8) || (0 == (add_sen_len = sense_buffer[7]))) | ||
1981 | return NULL; | ||
1982 | if ((sense_buffer[0] < 0x72) || (sense_buffer[0] > 0x73)) | ||
1983 | return NULL; | ||
1984 | add_sen_len = (add_sen_len < (sb_len - 8)) ? | ||
1985 | add_sen_len : (sb_len - 8); | ||
1986 | descp = &sense_buffer[8]; | ||
1987 | for (desc_len = 0, k = 0; k < add_sen_len; k += desc_len) { | ||
1988 | descp += desc_len; | ||
1989 | add_len = (k < (add_sen_len - 1)) ? descp[1]: -1; | ||
1990 | desc_len = add_len + 2; | ||
1991 | if (descp[0] == desc_type) | ||
1992 | return descp; | ||
1993 | if (add_len < 0) // short descriptor ?? | ||
1994 | break; | ||
1995 | } | ||
1996 | return NULL; | ||
1997 | } | ||
1998 | EXPORT_SYMBOL(scsi_sense_desc_find); | ||
1999 | |||
2000 | /** | ||
2001 | * scsi_get_sense_info_fld - attempts to get information field from | ||
2002 | * sense data (either fixed or descriptor format) | ||
2003 | * | ||
2004 | * @sense_buffer: byte array of sense data | ||
2005 | * @sb_len: number of valid bytes in sense_buffer | ||
2006 | * @info_out: pointer to 64 integer where 8 or 4 byte information | ||
2007 | * field will be placed if found. | ||
2008 | * | ||
2009 | * Return value: | ||
2010 | * 1 if information field found, 0 if not found. | ||
2011 | **/ | ||
2012 | int scsi_get_sense_info_fld(const u8 * sense_buffer, int sb_len, | ||
2013 | u64 * info_out) | ||
2014 | { | ||
2015 | int j; | ||
2016 | const u8 * ucp; | ||
2017 | u64 ull; | ||
2018 | |||
2019 | if (sb_len < 7) | ||
2020 | return 0; | ||
2021 | switch (sense_buffer[0] & 0x7f) { | ||
2022 | case 0x70: | ||
2023 | case 0x71: | ||
2024 | if (sense_buffer[0] & 0x80) { | ||
2025 | *info_out = (sense_buffer[3] << 24) + | ||
2026 | (sense_buffer[4] << 16) + | ||
2027 | (sense_buffer[5] << 8) + sense_buffer[6]; | ||
2028 | return 1; | ||
2029 | } else | ||
2030 | return 0; | ||
2031 | case 0x72: | ||
2032 | case 0x73: | ||
2033 | ucp = scsi_sense_desc_find(sense_buffer, sb_len, | ||
2034 | 0 /* info desc */); | ||
2035 | if (ucp && (0xa == ucp[1])) { | ||
2036 | ull = 0; | ||
2037 | for (j = 0; j < 8; ++j) { | ||
2038 | if (j > 0) | ||
2039 | ull <<= 8; | ||
2040 | ull |= ucp[4 + j]; | ||
2041 | } | ||
2042 | *info_out = ull; | ||
2043 | return 1; | ||
2044 | } else | ||
2045 | return 0; | ||
2046 | default: | ||
2047 | return 0; | ||
2048 | } | ||
2049 | } | ||
2050 | EXPORT_SYMBOL(scsi_get_sense_info_fld); | ||