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