1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 1999 Eric Youngdale 4 * Copyright (C) 2014 Christoph Hellwig 5 * 6 * SCSI queueing library. 7 * Initial versions: Eric Youngdale (eric@andante.org). 8 * Based upon conversations with large numbers 9 * of people at Linux Expo. 10 */ 11 12 #include <linux/bio.h> 13 #include <linux/bitops.h> 14 #include <linux/blkdev.h> 15 #include <linux/completion.h> 16 #include <linux/kernel.h> 17 #include <linux/export.h> 18 #include <linux/init.h> 19 #include <linux/pci.h> 20 #include <linux/delay.h> 21 #include <linux/hardirq.h> 22 #include <linux/scatterlist.h> 23 #include <linux/blk-mq.h> 24 #include <linux/blk-integrity.h> 25 #include <linux/ratelimit.h> 26 #include <asm/unaligned.h> 27 28 #include <scsi/scsi.h> 29 #include <scsi/scsi_cmnd.h> 30 #include <scsi/scsi_dbg.h> 31 #include <scsi/scsi_device.h> 32 #include <scsi/scsi_driver.h> 33 #include <scsi/scsi_eh.h> 34 #include <scsi/scsi_host.h> 35 #include <scsi/scsi_transport.h> /* scsi_init_limits() */ 36 #include <scsi/scsi_dh.h> 37 38 #include <trace/events/scsi.h> 39 40 #include "scsi_debugfs.h" 41 #include "scsi_priv.h" 42 #include "scsi_logging.h" 43 44 /* 45 * Size of integrity metadata is usually small, 1 inline sg should 46 * cover normal cases. 47 */ 48 #ifdef CONFIG_ARCH_NO_SG_CHAIN 49 #define SCSI_INLINE_PROT_SG_CNT 0 50 #define SCSI_INLINE_SG_CNT 0 51 #else 52 #define SCSI_INLINE_PROT_SG_CNT 1 53 #define SCSI_INLINE_SG_CNT 2 54 #endif 55 56 static struct kmem_cache *scsi_sense_cache; 57 static DEFINE_MUTEX(scsi_sense_cache_mutex); 58 59 static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd); 60 61 int scsi_init_sense_cache(struct Scsi_Host *shost) 62 { 63 int ret = 0; 64 65 mutex_lock(&scsi_sense_cache_mutex); 66 if (!scsi_sense_cache) { 67 scsi_sense_cache = 68 kmem_cache_create_usercopy("scsi_sense_cache", 69 SCSI_SENSE_BUFFERSIZE, 0, SLAB_HWCACHE_ALIGN, 70 0, SCSI_SENSE_BUFFERSIZE, NULL); 71 if (!scsi_sense_cache) 72 ret = -ENOMEM; 73 } 74 mutex_unlock(&scsi_sense_cache_mutex); 75 return ret; 76 } 77 78 static void 79 scsi_set_blocked(struct scsi_cmnd *cmd, int reason) 80 { 81 struct Scsi_Host *host = cmd->device->host; 82 struct scsi_device *device = cmd->device; 83 struct scsi_target *starget = scsi_target(device); 84 85 /* 86 * Set the appropriate busy bit for the device/host. 87 * 88 * If the host/device isn't busy, assume that something actually 89 * completed, and that we should be able to queue a command now. 90 * 91 * Note that the prior mid-layer assumption that any host could 92 * always queue at least one command is now broken. The mid-layer 93 * will implement a user specifiable stall (see 94 * scsi_host.max_host_blocked and scsi_device.max_device_blocked) 95 * if a command is requeued with no other commands outstanding 96 * either for the device or for the host. 97 */ 98 switch (reason) { 99 case SCSI_MLQUEUE_HOST_BUSY: 100 atomic_set(&host->host_blocked, host->max_host_blocked); 101 break; 102 case SCSI_MLQUEUE_DEVICE_BUSY: 103 case SCSI_MLQUEUE_EH_RETRY: 104 atomic_set(&device->device_blocked, 105 device->max_device_blocked); 106 break; 107 case SCSI_MLQUEUE_TARGET_BUSY: 108 atomic_set(&starget->target_blocked, 109 starget->max_target_blocked); 110 break; 111 } 112 } 113 114 static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd, unsigned long msecs) 115 { 116 struct request *rq = scsi_cmd_to_rq(cmd); 117 118 if (rq->rq_flags & RQF_DONTPREP) { 119 rq->rq_flags &= ~RQF_DONTPREP; 120 scsi_mq_uninit_cmd(cmd); 121 } else { 122 WARN_ON_ONCE(true); 123 } 124 125 blk_mq_requeue_request(rq, false); 126 if (!scsi_host_in_recovery(cmd->device->host)) 127 blk_mq_delay_kick_requeue_list(rq->q, msecs); 128 } 129 130 /** 131 * __scsi_queue_insert - private queue insertion 132 * @cmd: The SCSI command being requeued 133 * @reason: The reason for the requeue 134 * @unbusy: Whether the queue should be unbusied 135 * 136 * This is a private queue insertion. The public interface 137 * scsi_queue_insert() always assumes the queue should be unbusied 138 * because it's always called before the completion. This function is 139 * for a requeue after completion, which should only occur in this 140 * file. 141 */ 142 static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy) 143 { 144 struct scsi_device *device = cmd->device; 145 146 SCSI_LOG_MLQUEUE(1, scmd_printk(KERN_INFO, cmd, 147 "Inserting command %p into mlqueue\n", cmd)); 148 149 scsi_set_blocked(cmd, reason); 150 151 /* 152 * Decrement the counters, since these commands are no longer 153 * active on the host/device. 154 */ 155 if (unbusy) 156 scsi_device_unbusy(device, cmd); 157 158 /* 159 * Requeue this command. It will go before all other commands 160 * that are already in the queue. Schedule requeue work under 161 * lock such that the kblockd_schedule_work() call happens 162 * before blk_mq_destroy_queue() finishes. 163 */ 164 cmd->result = 0; 165 166 blk_mq_requeue_request(scsi_cmd_to_rq(cmd), 167 !scsi_host_in_recovery(cmd->device->host)); 168 } 169 170 /** 171 * scsi_queue_insert - Reinsert a command in the queue. 172 * @cmd: command that we are adding to queue. 173 * @reason: why we are inserting command to queue. 174 * 175 * We do this for one of two cases. Either the host is busy and it cannot accept 176 * any more commands for the time being, or the device returned QUEUE_FULL and 177 * can accept no more commands. 178 * 179 * Context: This could be called either from an interrupt context or a normal 180 * process context. 181 */ 182 void scsi_queue_insert(struct scsi_cmnd *cmd, int reason) 183 { 184 __scsi_queue_insert(cmd, reason, true); 185 } 186 187 void scsi_failures_reset_retries(struct scsi_failures *failures) 188 { 189 struct scsi_failure *failure; 190 191 failures->total_retries = 0; 192 193 for (failure = failures->failure_definitions; failure->result; 194 failure++) 195 failure->retries = 0; 196 } 197 EXPORT_SYMBOL_GPL(scsi_failures_reset_retries); 198 199 /** 200 * scsi_check_passthrough - Determine if passthrough scsi_cmnd needs a retry. 201 * @scmd: scsi_cmnd to check. 202 * @failures: scsi_failures struct that lists failures to check for. 203 * 204 * Returns -EAGAIN if the caller should retry else 0. 205 */ 206 static int scsi_check_passthrough(struct scsi_cmnd *scmd, 207 struct scsi_failures *failures) 208 { 209 struct scsi_failure *failure; 210 struct scsi_sense_hdr sshdr; 211 enum sam_status status; 212 213 if (!failures) 214 return 0; 215 216 for (failure = failures->failure_definitions; failure->result; 217 failure++) { 218 if (failure->result == SCMD_FAILURE_RESULT_ANY) 219 goto maybe_retry; 220 221 if (host_byte(scmd->result) && 222 host_byte(scmd->result) == host_byte(failure->result)) 223 goto maybe_retry; 224 225 status = status_byte(scmd->result); 226 if (!status) 227 continue; 228 229 if (failure->result == SCMD_FAILURE_STAT_ANY && 230 !scsi_status_is_good(scmd->result)) 231 goto maybe_retry; 232 233 if (status != status_byte(failure->result)) 234 continue; 235 236 if (status_byte(failure->result) != SAM_STAT_CHECK_CONDITION || 237 failure->sense == SCMD_FAILURE_SENSE_ANY) 238 goto maybe_retry; 239 240 if (!scsi_command_normalize_sense(scmd, &sshdr)) 241 return 0; 242 243 if (failure->sense != sshdr.sense_key) 244 continue; 245 246 if (failure->asc == SCMD_FAILURE_ASC_ANY) 247 goto maybe_retry; 248 249 if (failure->asc != sshdr.asc) 250 continue; 251 252 if (failure->ascq == SCMD_FAILURE_ASCQ_ANY || 253 failure->ascq == sshdr.ascq) 254 goto maybe_retry; 255 } 256 257 return 0; 258 259 maybe_retry: 260 if (failure->allowed) { 261 if (failure->allowed == SCMD_FAILURE_NO_LIMIT || 262 ++failure->retries <= failure->allowed) 263 return -EAGAIN; 264 } else { 265 if (failures->total_allowed == SCMD_FAILURE_NO_LIMIT || 266 ++failures->total_retries <= failures->total_allowed) 267 return -EAGAIN; 268 } 269 270 return 0; 271 } 272 273 /** 274 * scsi_execute_cmd - insert request and wait for the result 275 * @sdev: scsi_device 276 * @cmd: scsi command 277 * @opf: block layer request cmd_flags 278 * @buffer: data buffer 279 * @bufflen: len of buffer 280 * @timeout: request timeout in HZ 281 * @ml_retries: number of times SCSI midlayer will retry request 282 * @args: Optional args. See struct definition for field descriptions 283 * 284 * Returns the scsi_cmnd result field if a command was executed, or a negative 285 * Linux error code if we didn't get that far. 286 */ 287 int scsi_execute_cmd(struct scsi_device *sdev, const unsigned char *cmd, 288 blk_opf_t opf, void *buffer, unsigned int bufflen, 289 int timeout, int ml_retries, 290 const struct scsi_exec_args *args) 291 { 292 static const struct scsi_exec_args default_args; 293 struct request *req; 294 struct scsi_cmnd *scmd; 295 int ret; 296 297 if (!args) 298 args = &default_args; 299 else if (WARN_ON_ONCE(args->sense && 300 args->sense_len != SCSI_SENSE_BUFFERSIZE)) 301 return -EINVAL; 302 303 retry: 304 req = scsi_alloc_request(sdev->request_queue, opf, args->req_flags); 305 if (IS_ERR(req)) 306 return PTR_ERR(req); 307 308 if (bufflen) { 309 ret = blk_rq_map_kern(sdev->request_queue, req, 310 buffer, bufflen, GFP_NOIO); 311 if (ret) 312 goto out; 313 } 314 scmd = blk_mq_rq_to_pdu(req); 315 scmd->cmd_len = COMMAND_SIZE(cmd[0]); 316 memcpy(scmd->cmnd, cmd, scmd->cmd_len); 317 scmd->allowed = ml_retries; 318 scmd->flags |= args->scmd_flags; 319 req->timeout = timeout; 320 req->rq_flags |= RQF_QUIET; 321 322 /* 323 * head injection *required* here otherwise quiesce won't work 324 */ 325 blk_execute_rq(req, true); 326 327 if (scsi_check_passthrough(scmd, args->failures) == -EAGAIN) { 328 blk_mq_free_request(req); 329 goto retry; 330 } 331 332 /* 333 * Some devices (USB mass-storage in particular) may transfer 334 * garbage data together with a residue indicating that the data 335 * is invalid. Prevent the garbage from being misinterpreted 336 * and prevent security leaks by zeroing out the excess data. 337 */ 338 if (unlikely(scmd->resid_len > 0 && scmd->resid_len <= bufflen)) 339 memset(buffer + bufflen - scmd->resid_len, 0, scmd->resid_len); 340 341 if (args->resid) 342 *args->resid = scmd->resid_len; 343 if (args->sense) 344 memcpy(args->sense, scmd->sense_buffer, SCSI_SENSE_BUFFERSIZE); 345 if (args->sshdr) 346 scsi_normalize_sense(scmd->sense_buffer, scmd->sense_len, 347 args->sshdr); 348 349 ret = scmd->result; 350 out: 351 blk_mq_free_request(req); 352 353 return ret; 354 } 355 EXPORT_SYMBOL(scsi_execute_cmd); 356 357 /* 358 * Wake up the error handler if necessary. Avoid as follows that the error 359 * handler is not woken up if host in-flight requests number == 360 * shost->host_failed: use call_rcu() in scsi_eh_scmd_add() in combination 361 * with an RCU read lock in this function to ensure that this function in 362 * its entirety either finishes before scsi_eh_scmd_add() increases the 363 * host_failed counter or that it notices the shost state change made by 364 * scsi_eh_scmd_add(). 365 */ 366 static void scsi_dec_host_busy(struct Scsi_Host *shost, struct scsi_cmnd *cmd) 367 { 368 unsigned long flags; 369 370 rcu_read_lock(); 371 __clear_bit(SCMD_STATE_INFLIGHT, &cmd->state); 372 if (unlikely(scsi_host_in_recovery(shost))) { 373 unsigned int busy = scsi_host_busy(shost); 374 375 spin_lock_irqsave(shost->host_lock, flags); 376 if (shost->host_failed || shost->host_eh_scheduled) 377 scsi_eh_wakeup(shost, busy); 378 spin_unlock_irqrestore(shost->host_lock, flags); 379 } 380 rcu_read_unlock(); 381 } 382 383 void scsi_device_unbusy(struct scsi_device *sdev, struct scsi_cmnd *cmd) 384 { 385 struct Scsi_Host *shost = sdev->host; 386 struct scsi_target *starget = scsi_target(sdev); 387 388 scsi_dec_host_busy(shost, cmd); 389 390 if (starget->can_queue > 0) 391 atomic_dec(&starget->target_busy); 392 393 sbitmap_put(&sdev->budget_map, cmd->budget_token); 394 cmd->budget_token = -1; 395 } 396 397 /* 398 * Kick the queue of SCSI device @sdev if @sdev != current_sdev. Called with 399 * interrupts disabled. 400 */ 401 static void scsi_kick_sdev_queue(struct scsi_device *sdev, void *data) 402 { 403 struct scsi_device *current_sdev = data; 404 405 if (sdev != current_sdev) 406 blk_mq_run_hw_queues(sdev->request_queue, true); 407 } 408 409 /* 410 * Called for single_lun devices on IO completion. Clear starget_sdev_user, 411 * and call blk_run_queue for all the scsi_devices on the target - 412 * including current_sdev first. 413 * 414 * Called with *no* scsi locks held. 415 */ 416 static void scsi_single_lun_run(struct scsi_device *current_sdev) 417 { 418 struct Scsi_Host *shost = current_sdev->host; 419 struct scsi_target *starget = scsi_target(current_sdev); 420 unsigned long flags; 421 422 spin_lock_irqsave(shost->host_lock, flags); 423 starget->starget_sdev_user = NULL; 424 spin_unlock_irqrestore(shost->host_lock, flags); 425 426 /* 427 * Call blk_run_queue for all LUNs on the target, starting with 428 * current_sdev. We race with others (to set starget_sdev_user), 429 * but in most cases, we will be first. Ideally, each LU on the 430 * target would get some limited time or requests on the target. 431 */ 432 blk_mq_run_hw_queues(current_sdev->request_queue, 433 shost->queuecommand_may_block); 434 435 spin_lock_irqsave(shost->host_lock, flags); 436 if (!starget->starget_sdev_user) 437 __starget_for_each_device(starget, current_sdev, 438 scsi_kick_sdev_queue); 439 spin_unlock_irqrestore(shost->host_lock, flags); 440 } 441 442 static inline bool scsi_device_is_busy(struct scsi_device *sdev) 443 { 444 if (scsi_device_busy(sdev) >= sdev->queue_depth) 445 return true; 446 if (atomic_read(&sdev->device_blocked) > 0) 447 return true; 448 return false; 449 } 450 451 static inline bool scsi_target_is_busy(struct scsi_target *starget) 452 { 453 if (starget->can_queue > 0) { 454 if (atomic_read(&starget->target_busy) >= starget->can_queue) 455 return true; 456 if (atomic_read(&starget->target_blocked) > 0) 457 return true; 458 } 459 return false; 460 } 461 462 static inline bool scsi_host_is_busy(struct Scsi_Host *shost) 463 { 464 if (atomic_read(&shost->host_blocked) > 0) 465 return true; 466 if (shost->host_self_blocked) 467 return true; 468 return false; 469 } 470 471 static void scsi_starved_list_run(struct Scsi_Host *shost) 472 { 473 LIST_HEAD(starved_list); 474 struct scsi_device *sdev; 475 unsigned long flags; 476 477 spin_lock_irqsave(shost->host_lock, flags); 478 list_splice_init(&shost->starved_list, &starved_list); 479 480 while (!list_empty(&starved_list)) { 481 struct request_queue *slq; 482 483 /* 484 * As long as shost is accepting commands and we have 485 * starved queues, call blk_run_queue. scsi_request_fn 486 * drops the queue_lock and can add us back to the 487 * starved_list. 488 * 489 * host_lock protects the starved_list and starved_entry. 490 * scsi_request_fn must get the host_lock before checking 491 * or modifying starved_list or starved_entry. 492 */ 493 if (scsi_host_is_busy(shost)) 494 break; 495 496 sdev = list_entry(starved_list.next, 497 struct scsi_device, starved_entry); 498 list_del_init(&sdev->starved_entry); 499 if (scsi_target_is_busy(scsi_target(sdev))) { 500 list_move_tail(&sdev->starved_entry, 501 &shost->starved_list); 502 continue; 503 } 504 505 /* 506 * Once we drop the host lock, a racing scsi_remove_device() 507 * call may remove the sdev from the starved list and destroy 508 * it and the queue. Mitigate by taking a reference to the 509 * queue and never touching the sdev again after we drop the 510 * host lock. Note: if __scsi_remove_device() invokes 511 * blk_mq_destroy_queue() before the queue is run from this 512 * function then blk_run_queue() will return immediately since 513 * blk_mq_destroy_queue() marks the queue with QUEUE_FLAG_DYING. 514 */ 515 slq = sdev->request_queue; 516 if (!blk_get_queue(slq)) 517 continue; 518 spin_unlock_irqrestore(shost->host_lock, flags); 519 520 blk_mq_run_hw_queues(slq, false); 521 blk_put_queue(slq); 522 523 spin_lock_irqsave(shost->host_lock, flags); 524 } 525 /* put any unprocessed entries back */ 526 list_splice(&starved_list, &shost->starved_list); 527 spin_unlock_irqrestore(shost->host_lock, flags); 528 } 529 530 /** 531 * scsi_run_queue - Select a proper request queue to serve next. 532 * @q: last request's queue 533 * 534 * The previous command was completely finished, start a new one if possible. 535 */ 536 static void scsi_run_queue(struct request_queue *q) 537 { 538 struct scsi_device *sdev = q->queuedata; 539 540 if (scsi_target(sdev)->single_lun) 541 scsi_single_lun_run(sdev); 542 if (!list_empty(&sdev->host->starved_list)) 543 scsi_starved_list_run(sdev->host); 544 545 /* Note: blk_mq_kick_requeue_list() runs the queue asynchronously. */ 546 blk_mq_kick_requeue_list(q); 547 } 548 549 void scsi_requeue_run_queue(struct work_struct *work) 550 { 551 struct scsi_device *sdev; 552 struct request_queue *q; 553 554 sdev = container_of(work, struct scsi_device, requeue_work); 555 q = sdev->request_queue; 556 scsi_run_queue(q); 557 } 558 559 void scsi_run_host_queues(struct Scsi_Host *shost) 560 { 561 struct scsi_device *sdev; 562 563 shost_for_each_device(sdev, shost) 564 scsi_run_queue(sdev->request_queue); 565 } 566 567 static void scsi_uninit_cmd(struct scsi_cmnd *cmd) 568 { 569 if (!blk_rq_is_passthrough(scsi_cmd_to_rq(cmd))) { 570 struct scsi_driver *drv = scsi_cmd_to_driver(cmd); 571 572 if (drv->uninit_command) 573 drv->uninit_command(cmd); 574 } 575 } 576 577 void scsi_free_sgtables(struct scsi_cmnd *cmd) 578 { 579 if (cmd->sdb.table.nents) 580 sg_free_table_chained(&cmd->sdb.table, 581 SCSI_INLINE_SG_CNT); 582 if (scsi_prot_sg_count(cmd)) 583 sg_free_table_chained(&cmd->prot_sdb->table, 584 SCSI_INLINE_PROT_SG_CNT); 585 } 586 EXPORT_SYMBOL_GPL(scsi_free_sgtables); 587 588 static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd) 589 { 590 scsi_free_sgtables(cmd); 591 scsi_uninit_cmd(cmd); 592 } 593 594 static void scsi_run_queue_async(struct scsi_device *sdev) 595 { 596 if (scsi_host_in_recovery(sdev->host)) 597 return; 598 599 if (scsi_target(sdev)->single_lun || 600 !list_empty(&sdev->host->starved_list)) { 601 kblockd_schedule_work(&sdev->requeue_work); 602 } else { 603 /* 604 * smp_mb() present in sbitmap_queue_clear() or implied in 605 * .end_io is for ordering writing .device_busy in 606 * scsi_device_unbusy() and reading sdev->restarts. 607 */ 608 int old = atomic_read(&sdev->restarts); 609 610 /* 611 * ->restarts has to be kept as non-zero if new budget 612 * contention occurs. 613 * 614 * No need to run queue when either another re-run 615 * queue wins in updating ->restarts or a new budget 616 * contention occurs. 617 */ 618 if (old && atomic_cmpxchg(&sdev->restarts, old, 0) == old) 619 blk_mq_run_hw_queues(sdev->request_queue, true); 620 } 621 } 622 623 /* Returns false when no more bytes to process, true if there are more */ 624 static bool scsi_end_request(struct request *req, blk_status_t error, 625 unsigned int bytes) 626 { 627 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); 628 struct scsi_device *sdev = cmd->device; 629 struct request_queue *q = sdev->request_queue; 630 631 if (blk_update_request(req, error, bytes)) 632 return true; 633 634 if (q->limits.features & BLK_FEAT_ADD_RANDOM) 635 add_disk_randomness(req->q->disk); 636 637 WARN_ON_ONCE(!blk_rq_is_passthrough(req) && 638 !(cmd->flags & SCMD_INITIALIZED)); 639 cmd->flags = 0; 640 641 /* 642 * Calling rcu_barrier() is not necessary here because the 643 * SCSI error handler guarantees that the function called by 644 * call_rcu() has been called before scsi_end_request() is 645 * called. 646 */ 647 destroy_rcu_head(&cmd->rcu); 648 649 /* 650 * In the MQ case the command gets freed by __blk_mq_end_request, 651 * so we have to do all cleanup that depends on it earlier. 652 * 653 * We also can't kick the queues from irq context, so we 654 * will have to defer it to a workqueue. 655 */ 656 scsi_mq_uninit_cmd(cmd); 657 658 /* 659 * queue is still alive, so grab the ref for preventing it 660 * from being cleaned up during running queue. 661 */ 662 percpu_ref_get(&q->q_usage_counter); 663 664 __blk_mq_end_request(req, error); 665 666 scsi_run_queue_async(sdev); 667 668 percpu_ref_put(&q->q_usage_counter); 669 return false; 670 } 671 672 /** 673 * scsi_result_to_blk_status - translate a SCSI result code into blk_status_t 674 * @result: scsi error code 675 * 676 * Translate a SCSI result code into a blk_status_t value. 677 */ 678 static blk_status_t scsi_result_to_blk_status(int result) 679 { 680 /* 681 * Check the scsi-ml byte first in case we converted a host or status 682 * byte. 683 */ 684 switch (scsi_ml_byte(result)) { 685 case SCSIML_STAT_OK: 686 break; 687 case SCSIML_STAT_RESV_CONFLICT: 688 return BLK_STS_RESV_CONFLICT; 689 case SCSIML_STAT_NOSPC: 690 return BLK_STS_NOSPC; 691 case SCSIML_STAT_MED_ERROR: 692 return BLK_STS_MEDIUM; 693 case SCSIML_STAT_TGT_FAILURE: 694 return BLK_STS_TARGET; 695 case SCSIML_STAT_DL_TIMEOUT: 696 return BLK_STS_DURATION_LIMIT; 697 } 698 699 switch (host_byte(result)) { 700 case DID_OK: 701 if (scsi_status_is_good(result)) 702 return BLK_STS_OK; 703 return BLK_STS_IOERR; 704 case DID_TRANSPORT_FAILFAST: 705 case DID_TRANSPORT_MARGINAL: 706 return BLK_STS_TRANSPORT; 707 default: 708 return BLK_STS_IOERR; 709 } 710 } 711 712 /** 713 * scsi_rq_err_bytes - determine number of bytes till the next failure boundary 714 * @rq: request to examine 715 * 716 * Description: 717 * A request could be merge of IOs which require different failure 718 * handling. This function determines the number of bytes which 719 * can be failed from the beginning of the request without 720 * crossing into area which need to be retried further. 721 * 722 * Return: 723 * The number of bytes to fail. 724 */ 725 static unsigned int scsi_rq_err_bytes(const struct request *rq) 726 { 727 blk_opf_t ff = rq->cmd_flags & REQ_FAILFAST_MASK; 728 unsigned int bytes = 0; 729 struct bio *bio; 730 731 if (!(rq->rq_flags & RQF_MIXED_MERGE)) 732 return blk_rq_bytes(rq); 733 734 /* 735 * Currently the only 'mixing' which can happen is between 736 * different fastfail types. We can safely fail portions 737 * which have all the failfast bits that the first one has - 738 * the ones which are at least as eager to fail as the first 739 * one. 740 */ 741 for (bio = rq->bio; bio; bio = bio->bi_next) { 742 if ((bio->bi_opf & ff) != ff) 743 break; 744 bytes += bio->bi_iter.bi_size; 745 } 746 747 /* this could lead to infinite loop */ 748 BUG_ON(blk_rq_bytes(rq) && !bytes); 749 return bytes; 750 } 751 752 static bool scsi_cmd_runtime_exceeced(struct scsi_cmnd *cmd) 753 { 754 struct request *req = scsi_cmd_to_rq(cmd); 755 unsigned long wait_for; 756 757 if (cmd->allowed == SCSI_CMD_RETRIES_NO_LIMIT) 758 return false; 759 760 wait_for = (cmd->allowed + 1) * req->timeout; 761 if (time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { 762 scmd_printk(KERN_ERR, cmd, "timing out command, waited %lus\n", 763 wait_for/HZ); 764 return true; 765 } 766 return false; 767 } 768 769 /* 770 * When ALUA transition state is returned, reprep the cmd to 771 * use the ALUA handler's transition timeout. Delay the reprep 772 * 1 sec to avoid aggressive retries of the target in that 773 * state. 774 */ 775 #define ALUA_TRANSITION_REPREP_DELAY 1000 776 777 /* Helper for scsi_io_completion() when special action required. */ 778 static void scsi_io_completion_action(struct scsi_cmnd *cmd, int result) 779 { 780 struct request *req = scsi_cmd_to_rq(cmd); 781 int level = 0; 782 enum {ACTION_FAIL, ACTION_REPREP, ACTION_DELAYED_REPREP, 783 ACTION_RETRY, ACTION_DELAYED_RETRY} action; 784 struct scsi_sense_hdr sshdr; 785 bool sense_valid; 786 bool sense_current = true; /* false implies "deferred sense" */ 787 blk_status_t blk_stat; 788 789 sense_valid = scsi_command_normalize_sense(cmd, &sshdr); 790 if (sense_valid) 791 sense_current = !scsi_sense_is_deferred(&sshdr); 792 793 blk_stat = scsi_result_to_blk_status(result); 794 795 if (host_byte(result) == DID_RESET) { 796 /* Third party bus reset or reset for error recovery 797 * reasons. Just retry the command and see what 798 * happens. 799 */ 800 action = ACTION_RETRY; 801 } else if (sense_valid && sense_current) { 802 switch (sshdr.sense_key) { 803 case UNIT_ATTENTION: 804 if (cmd->device->removable) { 805 /* Detected disc change. Set a bit 806 * and quietly refuse further access. 807 */ 808 cmd->device->changed = 1; 809 action = ACTION_FAIL; 810 } else { 811 /* Must have been a power glitch, or a 812 * bus reset. Could not have been a 813 * media change, so we just retry the 814 * command and see what happens. 815 */ 816 action = ACTION_RETRY; 817 } 818 break; 819 case ILLEGAL_REQUEST: 820 /* If we had an ILLEGAL REQUEST returned, then 821 * we may have performed an unsupported 822 * command. The only thing this should be 823 * would be a ten byte read where only a six 824 * byte read was supported. Also, on a system 825 * where READ CAPACITY failed, we may have 826 * read past the end of the disk. 827 */ 828 if ((cmd->device->use_10_for_rw && 829 sshdr.asc == 0x20 && sshdr.ascq == 0x00) && 830 (cmd->cmnd[0] == READ_10 || 831 cmd->cmnd[0] == WRITE_10)) { 832 /* This will issue a new 6-byte command. */ 833 cmd->device->use_10_for_rw = 0; 834 action = ACTION_REPREP; 835 } else if (sshdr.asc == 0x10) /* DIX */ { 836 action = ACTION_FAIL; 837 blk_stat = BLK_STS_PROTECTION; 838 /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */ 839 } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) { 840 action = ACTION_FAIL; 841 blk_stat = BLK_STS_TARGET; 842 } else 843 action = ACTION_FAIL; 844 break; 845 case ABORTED_COMMAND: 846 action = ACTION_FAIL; 847 if (sshdr.asc == 0x10) /* DIF */ 848 blk_stat = BLK_STS_PROTECTION; 849 break; 850 case NOT_READY: 851 /* If the device is in the process of becoming 852 * ready, or has a temporary blockage, retry. 853 */ 854 if (sshdr.asc == 0x04) { 855 switch (sshdr.ascq) { 856 case 0x01: /* becoming ready */ 857 case 0x04: /* format in progress */ 858 case 0x05: /* rebuild in progress */ 859 case 0x06: /* recalculation in progress */ 860 case 0x07: /* operation in progress */ 861 case 0x08: /* Long write in progress */ 862 case 0x09: /* self test in progress */ 863 case 0x11: /* notify (enable spinup) required */ 864 case 0x14: /* space allocation in progress */ 865 case 0x1a: /* start stop unit in progress */ 866 case 0x1b: /* sanitize in progress */ 867 case 0x1d: /* configuration in progress */ 868 case 0x24: /* depopulation in progress */ 869 case 0x25: /* depopulation restore in progress */ 870 action = ACTION_DELAYED_RETRY; 871 break; 872 case 0x0a: /* ALUA state transition */ 873 action = ACTION_DELAYED_REPREP; 874 break; 875 default: 876 action = ACTION_FAIL; 877 break; 878 } 879 } else 880 action = ACTION_FAIL; 881 break; 882 case VOLUME_OVERFLOW: 883 /* See SSC3rXX or current. */ 884 action = ACTION_FAIL; 885 break; 886 case DATA_PROTECT: 887 action = ACTION_FAIL; 888 if ((sshdr.asc == 0x0C && sshdr.ascq == 0x12) || 889 (sshdr.asc == 0x55 && 890 (sshdr.ascq == 0x0E || sshdr.ascq == 0x0F))) { 891 /* Insufficient zone resources */ 892 blk_stat = BLK_STS_ZONE_OPEN_RESOURCE; 893 } 894 break; 895 case COMPLETED: 896 fallthrough; 897 default: 898 action = ACTION_FAIL; 899 break; 900 } 901 } else 902 action = ACTION_FAIL; 903 904 if (action != ACTION_FAIL && scsi_cmd_runtime_exceeced(cmd)) 905 action = ACTION_FAIL; 906 907 switch (action) { 908 case ACTION_FAIL: 909 /* Give up and fail the remainder of the request */ 910 if (!(req->rq_flags & RQF_QUIET)) { 911 static DEFINE_RATELIMIT_STATE(_rs, 912 DEFAULT_RATELIMIT_INTERVAL, 913 DEFAULT_RATELIMIT_BURST); 914 915 if (unlikely(scsi_logging_level)) 916 level = 917 SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, 918 SCSI_LOG_MLCOMPLETE_BITS); 919 920 /* 921 * if logging is enabled the failure will be printed 922 * in scsi_log_completion(), so avoid duplicate messages 923 */ 924 if (!level && __ratelimit(&_rs)) { 925 scsi_print_result(cmd, NULL, FAILED); 926 if (sense_valid) 927 scsi_print_sense(cmd); 928 scsi_print_command(cmd); 929 } 930 } 931 if (!scsi_end_request(req, blk_stat, scsi_rq_err_bytes(req))) 932 return; 933 fallthrough; 934 case ACTION_REPREP: 935 scsi_mq_requeue_cmd(cmd, 0); 936 break; 937 case ACTION_DELAYED_REPREP: 938 scsi_mq_requeue_cmd(cmd, ALUA_TRANSITION_REPREP_DELAY); 939 break; 940 case ACTION_RETRY: 941 /* Retry the same command immediately */ 942 __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, false); 943 break; 944 case ACTION_DELAYED_RETRY: 945 /* Retry the same command after a delay */ 946 __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, false); 947 break; 948 } 949 } 950 951 /* 952 * Helper for scsi_io_completion() when cmd->result is non-zero. Returns a 953 * new result that may suppress further error checking. Also modifies 954 * *blk_statp in some cases. 955 */ 956 static int scsi_io_completion_nz_result(struct scsi_cmnd *cmd, int result, 957 blk_status_t *blk_statp) 958 { 959 bool sense_valid; 960 bool sense_current = true; /* false implies "deferred sense" */ 961 struct request *req = scsi_cmd_to_rq(cmd); 962 struct scsi_sense_hdr sshdr; 963 964 sense_valid = scsi_command_normalize_sense(cmd, &sshdr); 965 if (sense_valid) 966 sense_current = !scsi_sense_is_deferred(&sshdr); 967 968 if (blk_rq_is_passthrough(req)) { 969 if (sense_valid) { 970 /* 971 * SG_IO wants current and deferred errors 972 */ 973 cmd->sense_len = min(8 + cmd->sense_buffer[7], 974 SCSI_SENSE_BUFFERSIZE); 975 } 976 if (sense_current) 977 *blk_statp = scsi_result_to_blk_status(result); 978 } else if (blk_rq_bytes(req) == 0 && sense_current) { 979 /* 980 * Flush commands do not transfers any data, and thus cannot use 981 * good_bytes != blk_rq_bytes(req) as the signal for an error. 982 * This sets *blk_statp explicitly for the problem case. 983 */ 984 *blk_statp = scsi_result_to_blk_status(result); 985 } 986 /* 987 * Recovered errors need reporting, but they're always treated as 988 * success, so fiddle the result code here. For passthrough requests 989 * we already took a copy of the original into sreq->result which 990 * is what gets returned to the user 991 */ 992 if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) { 993 bool do_print = true; 994 /* 995 * if ATA PASS-THROUGH INFORMATION AVAILABLE [0x0, 0x1d] 996 * skip print since caller wants ATA registers. Only occurs 997 * on SCSI ATA PASS_THROUGH commands when CK_COND=1 998 */ 999 if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d)) 1000 do_print = false; 1001 else if (req->rq_flags & RQF_QUIET) 1002 do_print = false; 1003 if (do_print) 1004 scsi_print_sense(cmd); 1005 result = 0; 1006 /* for passthrough, *blk_statp may be set */ 1007 *blk_statp = BLK_STS_OK; 1008 } 1009 /* 1010 * Another corner case: the SCSI status byte is non-zero but 'good'. 1011 * Example: PRE-FETCH command returns SAM_STAT_CONDITION_MET when 1012 * it is able to fit nominated LBs in its cache (and SAM_STAT_GOOD 1013 * if it can't fit). Treat SAM_STAT_CONDITION_MET and the related 1014 * intermediate statuses (both obsolete in SAM-4) as good. 1015 */ 1016 if ((result & 0xff) && scsi_status_is_good(result)) { 1017 result = 0; 1018 *blk_statp = BLK_STS_OK; 1019 } 1020 return result; 1021 } 1022 1023 /** 1024 * scsi_io_completion - Completion processing for SCSI commands. 1025 * @cmd: command that is finished. 1026 * @good_bytes: number of processed bytes. 1027 * 1028 * We will finish off the specified number of sectors. If we are done, the 1029 * command block will be released and the queue function will be goosed. If we 1030 * are not done then we have to figure out what to do next: 1031 * 1032 * a) We can call scsi_mq_requeue_cmd(). The request will be 1033 * unprepared and put back on the queue. Then a new command will 1034 * be created for it. This should be used if we made forward 1035 * progress, or if we want to switch from READ(10) to READ(6) for 1036 * example. 1037 * 1038 * b) We can call scsi_io_completion_action(). The request will be 1039 * put back on the queue and retried using the same command as 1040 * before, possibly after a delay. 1041 * 1042 * c) We can call scsi_end_request() with blk_stat other than 1043 * BLK_STS_OK, to fail the remainder of the request. 1044 */ 1045 void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) 1046 { 1047 int result = cmd->result; 1048 struct request *req = scsi_cmd_to_rq(cmd); 1049 blk_status_t blk_stat = BLK_STS_OK; 1050 1051 if (unlikely(result)) /* a nz result may or may not be an error */ 1052 result = scsi_io_completion_nz_result(cmd, result, &blk_stat); 1053 1054 /* 1055 * Next deal with any sectors which we were able to correctly 1056 * handle. 1057 */ 1058 SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, cmd, 1059 "%u sectors total, %d bytes done.\n", 1060 blk_rq_sectors(req), good_bytes)); 1061 1062 /* 1063 * Failed, zero length commands always need to drop down 1064 * to retry code. Fast path should return in this block. 1065 */ 1066 if (likely(blk_rq_bytes(req) > 0 || blk_stat == BLK_STS_OK)) { 1067 if (likely(!scsi_end_request(req, blk_stat, good_bytes))) 1068 return; /* no bytes remaining */ 1069 } 1070 1071 /* Kill remainder if no retries. */ 1072 if (unlikely(blk_stat && scsi_noretry_cmd(cmd))) { 1073 if (scsi_end_request(req, blk_stat, blk_rq_bytes(req))) 1074 WARN_ONCE(true, 1075 "Bytes remaining after failed, no-retry command"); 1076 return; 1077 } 1078 1079 /* 1080 * If there had been no error, but we have leftover bytes in the 1081 * request just queue the command up again. 1082 */ 1083 if (likely(result == 0)) 1084 scsi_mq_requeue_cmd(cmd, 0); 1085 else 1086 scsi_io_completion_action(cmd, result); 1087 } 1088 1089 static inline bool scsi_cmd_needs_dma_drain(struct scsi_device *sdev, 1090 struct request *rq) 1091 { 1092 return sdev->dma_drain_len && blk_rq_is_passthrough(rq) && 1093 !op_is_write(req_op(rq)) && 1094 sdev->host->hostt->dma_need_drain(rq); 1095 } 1096 1097 /** 1098 * scsi_alloc_sgtables - Allocate and initialize data and integrity scatterlists 1099 * @cmd: SCSI command data structure to initialize. 1100 * 1101 * Initializes @cmd->sdb and also @cmd->prot_sdb if data integrity is enabled 1102 * for @cmd. 1103 * 1104 * Returns: 1105 * * BLK_STS_OK - on success 1106 * * BLK_STS_RESOURCE - if the failure is retryable 1107 * * BLK_STS_IOERR - if the failure is fatal 1108 */ 1109 blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd) 1110 { 1111 struct scsi_device *sdev = cmd->device; 1112 struct request *rq = scsi_cmd_to_rq(cmd); 1113 unsigned short nr_segs = blk_rq_nr_phys_segments(rq); 1114 struct scatterlist *last_sg = NULL; 1115 blk_status_t ret; 1116 bool need_drain = scsi_cmd_needs_dma_drain(sdev, rq); 1117 int count; 1118 1119 if (WARN_ON_ONCE(!nr_segs)) 1120 return BLK_STS_IOERR; 1121 1122 /* 1123 * Make sure there is space for the drain. The driver must adjust 1124 * max_hw_segments to be prepared for this. 1125 */ 1126 if (need_drain) 1127 nr_segs++; 1128 1129 /* 1130 * If sg table allocation fails, requeue request later. 1131 */ 1132 if (unlikely(sg_alloc_table_chained(&cmd->sdb.table, nr_segs, 1133 cmd->sdb.table.sgl, SCSI_INLINE_SG_CNT))) 1134 return BLK_STS_RESOURCE; 1135 1136 /* 1137 * Next, walk the list, and fill in the addresses and sizes of 1138 * each segment. 1139 */ 1140 count = __blk_rq_map_sg(rq->q, rq, cmd->sdb.table.sgl, &last_sg); 1141 1142 if (blk_rq_bytes(rq) & rq->q->limits.dma_pad_mask) { 1143 unsigned int pad_len = 1144 (rq->q->limits.dma_pad_mask & ~blk_rq_bytes(rq)) + 1; 1145 1146 last_sg->length += pad_len; 1147 cmd->extra_len += pad_len; 1148 } 1149 1150 if (need_drain) { 1151 sg_unmark_end(last_sg); 1152 last_sg = sg_next(last_sg); 1153 sg_set_buf(last_sg, sdev->dma_drain_buf, sdev->dma_drain_len); 1154 sg_mark_end(last_sg); 1155 1156 cmd->extra_len += sdev->dma_drain_len; 1157 count++; 1158 } 1159 1160 BUG_ON(count > cmd->sdb.table.nents); 1161 cmd->sdb.table.nents = count; 1162 cmd->sdb.length = blk_rq_payload_bytes(rq); 1163 1164 if (blk_integrity_rq(rq)) { 1165 struct scsi_data_buffer *prot_sdb = cmd->prot_sdb; 1166 int ivecs; 1167 1168 if (WARN_ON_ONCE(!prot_sdb)) { 1169 /* 1170 * This can happen if someone (e.g. multipath) 1171 * queues a command to a device on an adapter 1172 * that does not support DIX. 1173 */ 1174 ret = BLK_STS_IOERR; 1175 goto out_free_sgtables; 1176 } 1177 1178 ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio); 1179 1180 if (sg_alloc_table_chained(&prot_sdb->table, ivecs, 1181 prot_sdb->table.sgl, 1182 SCSI_INLINE_PROT_SG_CNT)) { 1183 ret = BLK_STS_RESOURCE; 1184 goto out_free_sgtables; 1185 } 1186 1187 count = blk_rq_map_integrity_sg(rq->q, rq->bio, 1188 prot_sdb->table.sgl); 1189 BUG_ON(count > ivecs); 1190 BUG_ON(count > queue_max_integrity_segments(rq->q)); 1191 1192 cmd->prot_sdb = prot_sdb; 1193 cmd->prot_sdb->table.nents = count; 1194 } 1195 1196 return BLK_STS_OK; 1197 out_free_sgtables: 1198 scsi_free_sgtables(cmd); 1199 return ret; 1200 } 1201 EXPORT_SYMBOL(scsi_alloc_sgtables); 1202 1203 /** 1204 * scsi_initialize_rq - initialize struct scsi_cmnd partially 1205 * @rq: Request associated with the SCSI command to be initialized. 1206 * 1207 * This function initializes the members of struct scsi_cmnd that must be 1208 * initialized before request processing starts and that won't be 1209 * reinitialized if a SCSI command is requeued. 1210 */ 1211 static void scsi_initialize_rq(struct request *rq) 1212 { 1213 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); 1214 1215 memset(cmd->cmnd, 0, sizeof(cmd->cmnd)); 1216 cmd->cmd_len = MAX_COMMAND_SIZE; 1217 cmd->sense_len = 0; 1218 init_rcu_head(&cmd->rcu); 1219 cmd->jiffies_at_alloc = jiffies; 1220 cmd->retries = 0; 1221 } 1222 1223 struct request *scsi_alloc_request(struct request_queue *q, blk_opf_t opf, 1224 blk_mq_req_flags_t flags) 1225 { 1226 struct request *rq; 1227 1228 rq = blk_mq_alloc_request(q, opf, flags); 1229 if (!IS_ERR(rq)) 1230 scsi_initialize_rq(rq); 1231 return rq; 1232 } 1233 EXPORT_SYMBOL_GPL(scsi_alloc_request); 1234 1235 /* 1236 * Only called when the request isn't completed by SCSI, and not freed by 1237 * SCSI 1238 */ 1239 static void scsi_cleanup_rq(struct request *rq) 1240 { 1241 if (rq->rq_flags & RQF_DONTPREP) { 1242 scsi_mq_uninit_cmd(blk_mq_rq_to_pdu(rq)); 1243 rq->rq_flags &= ~RQF_DONTPREP; 1244 } 1245 } 1246 1247 /* Called before a request is prepared. See also scsi_mq_prep_fn(). */ 1248 void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd) 1249 { 1250 struct request *rq = scsi_cmd_to_rq(cmd); 1251 1252 if (!blk_rq_is_passthrough(rq) && !(cmd->flags & SCMD_INITIALIZED)) { 1253 cmd->flags |= SCMD_INITIALIZED; 1254 scsi_initialize_rq(rq); 1255 } 1256 1257 cmd->device = dev; 1258 INIT_LIST_HEAD(&cmd->eh_entry); 1259 INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler); 1260 } 1261 1262 static blk_status_t scsi_setup_scsi_cmnd(struct scsi_device *sdev, 1263 struct request *req) 1264 { 1265 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); 1266 1267 /* 1268 * Passthrough requests may transfer data, in which case they must 1269 * a bio attached to them. Or they might contain a SCSI command 1270 * that does not transfer data, in which case they may optionally 1271 * submit a request without an attached bio. 1272 */ 1273 if (req->bio) { 1274 blk_status_t ret = scsi_alloc_sgtables(cmd); 1275 if (unlikely(ret != BLK_STS_OK)) 1276 return ret; 1277 } else { 1278 BUG_ON(blk_rq_bytes(req)); 1279 1280 memset(&cmd->sdb, 0, sizeof(cmd->sdb)); 1281 } 1282 1283 cmd->transfersize = blk_rq_bytes(req); 1284 return BLK_STS_OK; 1285 } 1286 1287 static blk_status_t 1288 scsi_device_state_check(struct scsi_device *sdev, struct request *req) 1289 { 1290 switch (sdev->sdev_state) { 1291 case SDEV_CREATED: 1292 return BLK_STS_OK; 1293 case SDEV_OFFLINE: 1294 case SDEV_TRANSPORT_OFFLINE: 1295 /* 1296 * If the device is offline we refuse to process any 1297 * commands. The device must be brought online 1298 * before trying any recovery commands. 1299 */ 1300 if (!sdev->offline_already) { 1301 sdev->offline_already = true; 1302 sdev_printk(KERN_ERR, sdev, 1303 "rejecting I/O to offline device\n"); 1304 } 1305 return BLK_STS_IOERR; 1306 case SDEV_DEL: 1307 /* 1308 * If the device is fully deleted, we refuse to 1309 * process any commands as well. 1310 */ 1311 sdev_printk(KERN_ERR, sdev, 1312 "rejecting I/O to dead device\n"); 1313 return BLK_STS_IOERR; 1314 case SDEV_BLOCK: 1315 case SDEV_CREATED_BLOCK: 1316 return BLK_STS_RESOURCE; 1317 case SDEV_QUIESCE: 1318 /* 1319 * If the device is blocked we only accept power management 1320 * commands. 1321 */ 1322 if (req && WARN_ON_ONCE(!(req->rq_flags & RQF_PM))) 1323 return BLK_STS_RESOURCE; 1324 return BLK_STS_OK; 1325 default: 1326 /* 1327 * For any other not fully online state we only allow 1328 * power management commands. 1329 */ 1330 if (req && !(req->rq_flags & RQF_PM)) 1331 return BLK_STS_OFFLINE; 1332 return BLK_STS_OK; 1333 } 1334 } 1335 1336 /* 1337 * scsi_dev_queue_ready: if we can send requests to sdev, assign one token 1338 * and return the token else return -1. 1339 */ 1340 static inline int scsi_dev_queue_ready(struct request_queue *q, 1341 struct scsi_device *sdev) 1342 { 1343 int token; 1344 1345 token = sbitmap_get(&sdev->budget_map); 1346 if (token < 0) 1347 return -1; 1348 1349 if (!atomic_read(&sdev->device_blocked)) 1350 return token; 1351 1352 /* 1353 * Only unblock if no other commands are pending and 1354 * if device_blocked has decreased to zero 1355 */ 1356 if (scsi_device_busy(sdev) > 1 || 1357 atomic_dec_return(&sdev->device_blocked) > 0) { 1358 sbitmap_put(&sdev->budget_map, token); 1359 return -1; 1360 } 1361 1362 SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev, 1363 "unblocking device at zero depth\n")); 1364 1365 return token; 1366 } 1367 1368 /* 1369 * scsi_target_queue_ready: checks if there we can send commands to target 1370 * @sdev: scsi device on starget to check. 1371 */ 1372 static inline int scsi_target_queue_ready(struct Scsi_Host *shost, 1373 struct scsi_device *sdev) 1374 { 1375 struct scsi_target *starget = scsi_target(sdev); 1376 unsigned int busy; 1377 1378 if (starget->single_lun) { 1379 spin_lock_irq(shost->host_lock); 1380 if (starget->starget_sdev_user && 1381 starget->starget_sdev_user != sdev) { 1382 spin_unlock_irq(shost->host_lock); 1383 return 0; 1384 } 1385 starget->starget_sdev_user = sdev; 1386 spin_unlock_irq(shost->host_lock); 1387 } 1388 1389 if (starget->can_queue <= 0) 1390 return 1; 1391 1392 busy = atomic_inc_return(&starget->target_busy) - 1; 1393 if (atomic_read(&starget->target_blocked) > 0) { 1394 if (busy) 1395 goto starved; 1396 1397 /* 1398 * unblock after target_blocked iterates to zero 1399 */ 1400 if (atomic_dec_return(&starget->target_blocked) > 0) 1401 goto out_dec; 1402 1403 SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget, 1404 "unblocking target at zero depth\n")); 1405 } 1406 1407 if (busy >= starget->can_queue) 1408 goto starved; 1409 1410 return 1; 1411 1412 starved: 1413 spin_lock_irq(shost->host_lock); 1414 list_move_tail(&sdev->starved_entry, &shost->starved_list); 1415 spin_unlock_irq(shost->host_lock); 1416 out_dec: 1417 if (starget->can_queue > 0) 1418 atomic_dec(&starget->target_busy); 1419 return 0; 1420 } 1421 1422 /* 1423 * scsi_host_queue_ready: if we can send requests to shost, return 1 else 1424 * return 0. We must end up running the queue again whenever 0 is 1425 * returned, else IO can hang. 1426 */ 1427 static inline int scsi_host_queue_ready(struct request_queue *q, 1428 struct Scsi_Host *shost, 1429 struct scsi_device *sdev, 1430 struct scsi_cmnd *cmd) 1431 { 1432 if (atomic_read(&shost->host_blocked) > 0) { 1433 if (scsi_host_busy(shost) > 0) 1434 goto starved; 1435 1436 /* 1437 * unblock after host_blocked iterates to zero 1438 */ 1439 if (atomic_dec_return(&shost->host_blocked) > 0) 1440 goto out_dec; 1441 1442 SCSI_LOG_MLQUEUE(3, 1443 shost_printk(KERN_INFO, shost, 1444 "unblocking host at zero depth\n")); 1445 } 1446 1447 if (shost->host_self_blocked) 1448 goto starved; 1449 1450 /* We're OK to process the command, so we can't be starved */ 1451 if (!list_empty(&sdev->starved_entry)) { 1452 spin_lock_irq(shost->host_lock); 1453 if (!list_empty(&sdev->starved_entry)) 1454 list_del_init(&sdev->starved_entry); 1455 spin_unlock_irq(shost->host_lock); 1456 } 1457 1458 __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); 1459 1460 return 1; 1461 1462 starved: 1463 spin_lock_irq(shost->host_lock); 1464 if (list_empty(&sdev->starved_entry)) 1465 list_add_tail(&sdev->starved_entry, &shost->starved_list); 1466 spin_unlock_irq(shost->host_lock); 1467 out_dec: 1468 scsi_dec_host_busy(shost, cmd); 1469 return 0; 1470 } 1471 1472 /* 1473 * Busy state exporting function for request stacking drivers. 1474 * 1475 * For efficiency, no lock is taken to check the busy state of 1476 * shost/starget/sdev, since the returned value is not guaranteed and 1477 * may be changed after request stacking drivers call the function, 1478 * regardless of taking lock or not. 1479 * 1480 * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi 1481 * needs to return 'not busy'. Otherwise, request stacking drivers 1482 * may hold requests forever. 1483 */ 1484 static bool scsi_mq_lld_busy(struct request_queue *q) 1485 { 1486 struct scsi_device *sdev = q->queuedata; 1487 struct Scsi_Host *shost; 1488 1489 if (blk_queue_dying(q)) 1490 return false; 1491 1492 shost = sdev->host; 1493 1494 /* 1495 * Ignore host/starget busy state. 1496 * Since block layer does not have a concept of fairness across 1497 * multiple queues, congestion of host/starget needs to be handled 1498 * in SCSI layer. 1499 */ 1500 if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev)) 1501 return true; 1502 1503 return false; 1504 } 1505 1506 /* 1507 * Block layer request completion callback. May be called from interrupt 1508 * context. 1509 */ 1510 static void scsi_complete(struct request *rq) 1511 { 1512 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); 1513 enum scsi_disposition disposition; 1514 1515 INIT_LIST_HEAD(&cmd->eh_entry); 1516 1517 atomic_inc(&cmd->device->iodone_cnt); 1518 if (cmd->result) 1519 atomic_inc(&cmd->device->ioerr_cnt); 1520 1521 disposition = scsi_decide_disposition(cmd); 1522 if (disposition != SUCCESS && scsi_cmd_runtime_exceeced(cmd)) 1523 disposition = SUCCESS; 1524 1525 scsi_log_completion(cmd, disposition); 1526 1527 switch (disposition) { 1528 case SUCCESS: 1529 scsi_finish_command(cmd); 1530 break; 1531 case NEEDS_RETRY: 1532 scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); 1533 break; 1534 case ADD_TO_MLQUEUE: 1535 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); 1536 break; 1537 default: 1538 scsi_eh_scmd_add(cmd); 1539 break; 1540 } 1541 } 1542 1543 /** 1544 * scsi_dispatch_cmd - Dispatch a command to the low-level driver. 1545 * @cmd: command block we are dispatching. 1546 * 1547 * Return: nonzero return request was rejected and device's queue needs to be 1548 * plugged. 1549 */ 1550 static int scsi_dispatch_cmd(struct scsi_cmnd *cmd) 1551 { 1552 struct Scsi_Host *host = cmd->device->host; 1553 int rtn = 0; 1554 1555 atomic_inc(&cmd->device->iorequest_cnt); 1556 1557 /* check if the device is still usable */ 1558 if (unlikely(cmd->device->sdev_state == SDEV_DEL)) { 1559 /* in SDEV_DEL we error all commands. DID_NO_CONNECT 1560 * returns an immediate error upwards, and signals 1561 * that the device is no longer present */ 1562 cmd->result = DID_NO_CONNECT << 16; 1563 goto done; 1564 } 1565 1566 /* Check to see if the scsi lld made this device blocked. */ 1567 if (unlikely(scsi_device_blocked(cmd->device))) { 1568 /* 1569 * in blocked state, the command is just put back on 1570 * the device queue. The suspend state has already 1571 * blocked the queue so future requests should not 1572 * occur until the device transitions out of the 1573 * suspend state. 1574 */ 1575 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, 1576 "queuecommand : device blocked\n")); 1577 atomic_dec(&cmd->device->iorequest_cnt); 1578 return SCSI_MLQUEUE_DEVICE_BUSY; 1579 } 1580 1581 /* Store the LUN value in cmnd, if needed. */ 1582 if (cmd->device->lun_in_cdb) 1583 cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | 1584 (cmd->device->lun << 5 & 0xe0); 1585 1586 scsi_log_send(cmd); 1587 1588 /* 1589 * Before we queue this command, check if the command 1590 * length exceeds what the host adapter can handle. 1591 */ 1592 if (cmd->cmd_len > cmd->device->host->max_cmd_len) { 1593 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, 1594 "queuecommand : command too long. " 1595 "cdb_size=%d host->max_cmd_len=%d\n", 1596 cmd->cmd_len, cmd->device->host->max_cmd_len)); 1597 cmd->result = (DID_ABORT << 16); 1598 goto done; 1599 } 1600 1601 if (unlikely(host->shost_state == SHOST_DEL)) { 1602 cmd->result = (DID_NO_CONNECT << 16); 1603 goto done; 1604 1605 } 1606 1607 trace_scsi_dispatch_cmd_start(cmd); 1608 rtn = host->hostt->queuecommand(host, cmd); 1609 if (rtn) { 1610 atomic_dec(&cmd->device->iorequest_cnt); 1611 trace_scsi_dispatch_cmd_error(cmd, rtn); 1612 if (rtn != SCSI_MLQUEUE_DEVICE_BUSY && 1613 rtn != SCSI_MLQUEUE_TARGET_BUSY) 1614 rtn = SCSI_MLQUEUE_HOST_BUSY; 1615 1616 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, 1617 "queuecommand : request rejected\n")); 1618 } 1619 1620 return rtn; 1621 done: 1622 scsi_done(cmd); 1623 return 0; 1624 } 1625 1626 /* Size in bytes of the sg-list stored in the scsi-mq command-private data. */ 1627 static unsigned int scsi_mq_inline_sgl_size(struct Scsi_Host *shost) 1628 { 1629 return min_t(unsigned int, shost->sg_tablesize, SCSI_INLINE_SG_CNT) * 1630 sizeof(struct scatterlist); 1631 } 1632 1633 static blk_status_t scsi_prepare_cmd(struct request *req) 1634 { 1635 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); 1636 struct scsi_device *sdev = req->q->queuedata; 1637 struct Scsi_Host *shost = sdev->host; 1638 bool in_flight = test_bit(SCMD_STATE_INFLIGHT, &cmd->state); 1639 struct scatterlist *sg; 1640 1641 scsi_init_command(sdev, cmd); 1642 1643 cmd->eh_eflags = 0; 1644 cmd->prot_type = 0; 1645 cmd->prot_flags = 0; 1646 cmd->submitter = 0; 1647 memset(&cmd->sdb, 0, sizeof(cmd->sdb)); 1648 cmd->underflow = 0; 1649 cmd->transfersize = 0; 1650 cmd->host_scribble = NULL; 1651 cmd->result = 0; 1652 cmd->extra_len = 0; 1653 cmd->state = 0; 1654 if (in_flight) 1655 __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); 1656 1657 /* 1658 * Only clear the driver-private command data if the LLD does not supply 1659 * a function to initialize that data. 1660 */ 1661 if (!shost->hostt->init_cmd_priv) 1662 memset(cmd + 1, 0, shost->hostt->cmd_size); 1663 1664 cmd->prot_op = SCSI_PROT_NORMAL; 1665 if (blk_rq_bytes(req)) 1666 cmd->sc_data_direction = rq_dma_dir(req); 1667 else 1668 cmd->sc_data_direction = DMA_NONE; 1669 1670 sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size; 1671 cmd->sdb.table.sgl = sg; 1672 1673 if (scsi_host_get_prot(shost)) { 1674 memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer)); 1675 1676 cmd->prot_sdb->table.sgl = 1677 (struct scatterlist *)(cmd->prot_sdb + 1); 1678 } 1679 1680 /* 1681 * Special handling for passthrough commands, which don't go to the ULP 1682 * at all: 1683 */ 1684 if (blk_rq_is_passthrough(req)) 1685 return scsi_setup_scsi_cmnd(sdev, req); 1686 1687 if (sdev->handler && sdev->handler->prep_fn) { 1688 blk_status_t ret = sdev->handler->prep_fn(sdev, req); 1689 1690 if (ret != BLK_STS_OK) 1691 return ret; 1692 } 1693 1694 /* Usually overridden by the ULP */ 1695 cmd->allowed = 0; 1696 memset(cmd->cmnd, 0, sizeof(cmd->cmnd)); 1697 return scsi_cmd_to_driver(cmd)->init_command(cmd); 1698 } 1699 1700 static void scsi_done_internal(struct scsi_cmnd *cmd, bool complete_directly) 1701 { 1702 struct request *req = scsi_cmd_to_rq(cmd); 1703 1704 switch (cmd->submitter) { 1705 case SUBMITTED_BY_BLOCK_LAYER: 1706 break; 1707 case SUBMITTED_BY_SCSI_ERROR_HANDLER: 1708 return scsi_eh_done(cmd); 1709 case SUBMITTED_BY_SCSI_RESET_IOCTL: 1710 return; 1711 } 1712 1713 if (unlikely(blk_should_fake_timeout(scsi_cmd_to_rq(cmd)->q))) 1714 return; 1715 if (unlikely(test_and_set_bit(SCMD_STATE_COMPLETE, &cmd->state))) 1716 return; 1717 trace_scsi_dispatch_cmd_done(cmd); 1718 1719 if (complete_directly) 1720 blk_mq_complete_request_direct(req, scsi_complete); 1721 else 1722 blk_mq_complete_request(req); 1723 } 1724 1725 void scsi_done(struct scsi_cmnd *cmd) 1726 { 1727 scsi_done_internal(cmd, false); 1728 } 1729 EXPORT_SYMBOL(scsi_done); 1730 1731 void scsi_done_direct(struct scsi_cmnd *cmd) 1732 { 1733 scsi_done_internal(cmd, true); 1734 } 1735 EXPORT_SYMBOL(scsi_done_direct); 1736 1737 static void scsi_mq_put_budget(struct request_queue *q, int budget_token) 1738 { 1739 struct scsi_device *sdev = q->queuedata; 1740 1741 sbitmap_put(&sdev->budget_map, budget_token); 1742 } 1743 1744 /* 1745 * When to reinvoke queueing after a resource shortage. It's 3 msecs to 1746 * not change behaviour from the previous unplug mechanism, experimentation 1747 * may prove this needs changing. 1748 */ 1749 #define SCSI_QUEUE_DELAY 3 1750 1751 static int scsi_mq_get_budget(struct request_queue *q) 1752 { 1753 struct scsi_device *sdev = q->queuedata; 1754 int token = scsi_dev_queue_ready(q, sdev); 1755 1756 if (token >= 0) 1757 return token; 1758 1759 atomic_inc(&sdev->restarts); 1760 1761 /* 1762 * Orders atomic_inc(&sdev->restarts) and atomic_read(&sdev->device_busy). 1763 * .restarts must be incremented before .device_busy is read because the 1764 * code in scsi_run_queue_async() depends on the order of these operations. 1765 */ 1766 smp_mb__after_atomic(); 1767 1768 /* 1769 * If all in-flight requests originated from this LUN are completed 1770 * before reading .device_busy, sdev->device_busy will be observed as 1771 * zero, then blk_mq_delay_run_hw_queues() will dispatch this request 1772 * soon. Otherwise, completion of one of these requests will observe 1773 * the .restarts flag, and the request queue will be run for handling 1774 * this request, see scsi_end_request(). 1775 */ 1776 if (unlikely(scsi_device_busy(sdev) == 0 && 1777 !scsi_device_blocked(sdev))) 1778 blk_mq_delay_run_hw_queues(sdev->request_queue, SCSI_QUEUE_DELAY); 1779 return -1; 1780 } 1781 1782 static void scsi_mq_set_rq_budget_token(struct request *req, int token) 1783 { 1784 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); 1785 1786 cmd->budget_token = token; 1787 } 1788 1789 static int scsi_mq_get_rq_budget_token(struct request *req) 1790 { 1791 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); 1792 1793 return cmd->budget_token; 1794 } 1795 1796 static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, 1797 const struct blk_mq_queue_data *bd) 1798 { 1799 struct request *req = bd->rq; 1800 struct request_queue *q = req->q; 1801 struct scsi_device *sdev = q->queuedata; 1802 struct Scsi_Host *shost = sdev->host; 1803 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); 1804 blk_status_t ret; 1805 int reason; 1806 1807 WARN_ON_ONCE(cmd->budget_token < 0); 1808 1809 /* 1810 * If the device is not in running state we will reject some or all 1811 * commands. 1812 */ 1813 if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { 1814 ret = scsi_device_state_check(sdev, req); 1815 if (ret != BLK_STS_OK) 1816 goto out_put_budget; 1817 } 1818 1819 ret = BLK_STS_RESOURCE; 1820 if (!scsi_target_queue_ready(shost, sdev)) 1821 goto out_put_budget; 1822 if (unlikely(scsi_host_in_recovery(shost))) { 1823 if (cmd->flags & SCMD_FAIL_IF_RECOVERING) 1824 ret = BLK_STS_OFFLINE; 1825 goto out_dec_target_busy; 1826 } 1827 if (!scsi_host_queue_ready(q, shost, sdev, cmd)) 1828 goto out_dec_target_busy; 1829 1830 if (!(req->rq_flags & RQF_DONTPREP)) { 1831 ret = scsi_prepare_cmd(req); 1832 if (ret != BLK_STS_OK) 1833 goto out_dec_host_busy; 1834 req->rq_flags |= RQF_DONTPREP; 1835 } else { 1836 clear_bit(SCMD_STATE_COMPLETE, &cmd->state); 1837 } 1838 1839 cmd->flags &= SCMD_PRESERVED_FLAGS; 1840 if (sdev->simple_tags) 1841 cmd->flags |= SCMD_TAGGED; 1842 if (bd->last) 1843 cmd->flags |= SCMD_LAST; 1844 1845 scsi_set_resid(cmd, 0); 1846 memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); 1847 cmd->submitter = SUBMITTED_BY_BLOCK_LAYER; 1848 1849 blk_mq_start_request(req); 1850 reason = scsi_dispatch_cmd(cmd); 1851 if (reason) { 1852 scsi_set_blocked(cmd, reason); 1853 ret = BLK_STS_RESOURCE; 1854 goto out_dec_host_busy; 1855 } 1856 1857 return BLK_STS_OK; 1858 1859 out_dec_host_busy: 1860 scsi_dec_host_busy(shost, cmd); 1861 out_dec_target_busy: 1862 if (scsi_target(sdev)->can_queue > 0) 1863 atomic_dec(&scsi_target(sdev)->target_busy); 1864 out_put_budget: 1865 scsi_mq_put_budget(q, cmd->budget_token); 1866 cmd->budget_token = -1; 1867 switch (ret) { 1868 case BLK_STS_OK: 1869 break; 1870 case BLK_STS_RESOURCE: 1871 if (scsi_device_blocked(sdev)) 1872 ret = BLK_STS_DEV_RESOURCE; 1873 break; 1874 case BLK_STS_AGAIN: 1875 cmd->result = DID_BUS_BUSY << 16; 1876 if (req->rq_flags & RQF_DONTPREP) 1877 scsi_mq_uninit_cmd(cmd); 1878 break; 1879 default: 1880 if (unlikely(!scsi_device_online(sdev))) 1881 cmd->result = DID_NO_CONNECT << 16; 1882 else 1883 cmd->result = DID_ERROR << 16; 1884 /* 1885 * Make sure to release all allocated resources when 1886 * we hit an error, as we will never see this command 1887 * again. 1888 */ 1889 if (req->rq_flags & RQF_DONTPREP) 1890 scsi_mq_uninit_cmd(cmd); 1891 scsi_run_queue_async(sdev); 1892 break; 1893 } 1894 return ret; 1895 } 1896 1897 static int scsi_mq_init_request(struct blk_mq_tag_set *set, struct request *rq, 1898 unsigned int hctx_idx, unsigned int numa_node) 1899 { 1900 struct Scsi_Host *shost = set->driver_data; 1901 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); 1902 struct scatterlist *sg; 1903 int ret = 0; 1904 1905 cmd->sense_buffer = 1906 kmem_cache_alloc_node(scsi_sense_cache, GFP_KERNEL, numa_node); 1907 if (!cmd->sense_buffer) 1908 return -ENOMEM; 1909 1910 if (scsi_host_get_prot(shost)) { 1911 sg = (void *)cmd + sizeof(struct scsi_cmnd) + 1912 shost->hostt->cmd_size; 1913 cmd->prot_sdb = (void *)sg + scsi_mq_inline_sgl_size(shost); 1914 } 1915 1916 if (shost->hostt->init_cmd_priv) { 1917 ret = shost->hostt->init_cmd_priv(shost, cmd); 1918 if (ret < 0) 1919 kmem_cache_free(scsi_sense_cache, cmd->sense_buffer); 1920 } 1921 1922 return ret; 1923 } 1924 1925 static void scsi_mq_exit_request(struct blk_mq_tag_set *set, struct request *rq, 1926 unsigned int hctx_idx) 1927 { 1928 struct Scsi_Host *shost = set->driver_data; 1929 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); 1930 1931 if (shost->hostt->exit_cmd_priv) 1932 shost->hostt->exit_cmd_priv(shost, cmd); 1933 kmem_cache_free(scsi_sense_cache, cmd->sense_buffer); 1934 } 1935 1936 1937 static int scsi_mq_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) 1938 { 1939 struct Scsi_Host *shost = hctx->driver_data; 1940 1941 if (shost->hostt->mq_poll) 1942 return shost->hostt->mq_poll(shost, hctx->queue_num); 1943 1944 return 0; 1945 } 1946 1947 static int scsi_init_hctx(struct blk_mq_hw_ctx *hctx, void *data, 1948 unsigned int hctx_idx) 1949 { 1950 struct Scsi_Host *shost = data; 1951 1952 hctx->driver_data = shost; 1953 return 0; 1954 } 1955 1956 static void scsi_map_queues(struct blk_mq_tag_set *set) 1957 { 1958 struct Scsi_Host *shost = container_of(set, struct Scsi_Host, tag_set); 1959 1960 if (shost->hostt->map_queues) 1961 return shost->hostt->map_queues(shost); 1962 blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]); 1963 } 1964 1965 void scsi_init_limits(struct Scsi_Host *shost, struct queue_limits *lim) 1966 { 1967 struct device *dev = shost->dma_dev; 1968 1969 memset(lim, 0, sizeof(*lim)); 1970 lim->max_segments = 1971 min_t(unsigned short, shost->sg_tablesize, SG_MAX_SEGMENTS); 1972 1973 if (scsi_host_prot_dma(shost)) { 1974 shost->sg_prot_tablesize = 1975 min_not_zero(shost->sg_prot_tablesize, 1976 (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS); 1977 BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize); 1978 lim->max_integrity_segments = shost->sg_prot_tablesize; 1979 } 1980 1981 lim->max_hw_sectors = shost->max_sectors; 1982 lim->seg_boundary_mask = shost->dma_boundary; 1983 lim->max_segment_size = shost->max_segment_size; 1984 lim->virt_boundary_mask = shost->virt_boundary_mask; 1985 lim->dma_alignment = max_t(unsigned int, 1986 shost->dma_alignment, dma_get_cache_alignment() - 1); 1987 1988 if (shost->no_highmem) 1989 lim->features |= BLK_FEAT_BOUNCE_HIGH; 1990 1991 /* 1992 * Propagate the DMA formation properties to the dma-mapping layer as 1993 * a courtesy service to the LLDDs. This needs to check that the buses 1994 * actually support the DMA API first, though. 1995 */ 1996 if (dev->dma_parms) { 1997 dma_set_seg_boundary(dev, shost->dma_boundary); 1998 dma_set_max_seg_size(dev, shost->max_segment_size); 1999 } 2000 } 2001 EXPORT_SYMBOL_GPL(scsi_init_limits); 2002 2003 static const struct blk_mq_ops scsi_mq_ops_no_commit = { 2004 .get_budget = scsi_mq_get_budget, 2005 .put_budget = scsi_mq_put_budget, 2006 .queue_rq = scsi_queue_rq, 2007 .complete = scsi_complete, 2008 .timeout = scsi_timeout, 2009 #ifdef CONFIG_BLK_DEBUG_FS 2010 .show_rq = scsi_show_rq, 2011 #endif 2012 .init_request = scsi_mq_init_request, 2013 .exit_request = scsi_mq_exit_request, 2014 .cleanup_rq = scsi_cleanup_rq, 2015 .busy = scsi_mq_lld_busy, 2016 .map_queues = scsi_map_queues, 2017 .init_hctx = scsi_init_hctx, 2018 .poll = scsi_mq_poll, 2019 .set_rq_budget_token = scsi_mq_set_rq_budget_token, 2020 .get_rq_budget_token = scsi_mq_get_rq_budget_token, 2021 }; 2022 2023 2024 static void scsi_commit_rqs(struct blk_mq_hw_ctx *hctx) 2025 { 2026 struct Scsi_Host *shost = hctx->driver_data; 2027 2028 shost->hostt->commit_rqs(shost, hctx->queue_num); 2029 } 2030 2031 static const struct blk_mq_ops scsi_mq_ops = { 2032 .get_budget = scsi_mq_get_budget, 2033 .put_budget = scsi_mq_put_budget, 2034 .queue_rq = scsi_queue_rq, 2035 .commit_rqs = scsi_commit_rqs, 2036 .complete = scsi_complete, 2037 .timeout = scsi_timeout, 2038 #ifdef CONFIG_BLK_DEBUG_FS 2039 .show_rq = scsi_show_rq, 2040 #endif 2041 .init_request = scsi_mq_init_request, 2042 .exit_request = scsi_mq_exit_request, 2043 .cleanup_rq = scsi_cleanup_rq, 2044 .busy = scsi_mq_lld_busy, 2045 .map_queues = scsi_map_queues, 2046 .init_hctx = scsi_init_hctx, 2047 .poll = scsi_mq_poll, 2048 .set_rq_budget_token = scsi_mq_set_rq_budget_token, 2049 .get_rq_budget_token = scsi_mq_get_rq_budget_token, 2050 }; 2051 2052 int scsi_mq_setup_tags(struct Scsi_Host *shost) 2053 { 2054 unsigned int cmd_size, sgl_size; 2055 struct blk_mq_tag_set *tag_set = &shost->tag_set; 2056 2057 sgl_size = max_t(unsigned int, sizeof(struct scatterlist), 2058 scsi_mq_inline_sgl_size(shost)); 2059 cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size + sgl_size; 2060 if (scsi_host_get_prot(shost)) 2061 cmd_size += sizeof(struct scsi_data_buffer) + 2062 sizeof(struct scatterlist) * SCSI_INLINE_PROT_SG_CNT; 2063 2064 memset(tag_set, 0, sizeof(*tag_set)); 2065 if (shost->hostt->commit_rqs) 2066 tag_set->ops = &scsi_mq_ops; 2067 else 2068 tag_set->ops = &scsi_mq_ops_no_commit; 2069 tag_set->nr_hw_queues = shost->nr_hw_queues ? : 1; 2070 tag_set->nr_maps = shost->nr_maps ? : 1; 2071 tag_set->queue_depth = shost->can_queue; 2072 tag_set->cmd_size = cmd_size; 2073 tag_set->numa_node = dev_to_node(shost->dma_dev); 2074 tag_set->flags = BLK_MQ_F_SHOULD_MERGE; 2075 tag_set->flags |= 2076 BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy); 2077 if (shost->queuecommand_may_block) 2078 tag_set->flags |= BLK_MQ_F_BLOCKING; 2079 tag_set->driver_data = shost; 2080 if (shost->host_tagset) 2081 tag_set->flags |= BLK_MQ_F_TAG_HCTX_SHARED; 2082 2083 return blk_mq_alloc_tag_set(tag_set); 2084 } 2085 2086 void scsi_mq_free_tags(struct kref *kref) 2087 { 2088 struct Scsi_Host *shost = container_of(kref, typeof(*shost), 2089 tagset_refcnt); 2090 2091 blk_mq_free_tag_set(&shost->tag_set); 2092 complete(&shost->tagset_freed); 2093 } 2094 2095 /** 2096 * scsi_device_from_queue - return sdev associated with a request_queue 2097 * @q: The request queue to return the sdev from 2098 * 2099 * Return the sdev associated with a request queue or NULL if the 2100 * request_queue does not reference a SCSI device. 2101 */ 2102 struct scsi_device *scsi_device_from_queue(struct request_queue *q) 2103 { 2104 struct scsi_device *sdev = NULL; 2105 2106 if (q->mq_ops == &scsi_mq_ops_no_commit || 2107 q->mq_ops == &scsi_mq_ops) 2108 sdev = q->queuedata; 2109 if (!sdev || !get_device(&sdev->sdev_gendev)) 2110 sdev = NULL; 2111 2112 return sdev; 2113 } 2114 /* 2115 * pktcdvd should have been integrated into the SCSI layers, but for historical 2116 * reasons like the old IDE driver it isn't. This export allows it to safely 2117 * probe if a given device is a SCSI one and only attach to that. 2118 */ 2119 #ifdef CONFIG_CDROM_PKTCDVD_MODULE 2120 EXPORT_SYMBOL_GPL(scsi_device_from_queue); 2121 #endif 2122 2123 /** 2124 * scsi_block_requests - Utility function used by low-level drivers to prevent 2125 * further commands from being queued to the device. 2126 * @shost: host in question 2127 * 2128 * There is no timer nor any other means by which the requests get unblocked 2129 * other than the low-level driver calling scsi_unblock_requests(). 2130 */ 2131 void scsi_block_requests(struct Scsi_Host *shost) 2132 { 2133 shost->host_self_blocked = 1; 2134 } 2135 EXPORT_SYMBOL(scsi_block_requests); 2136 2137 /** 2138 * scsi_unblock_requests - Utility function used by low-level drivers to allow 2139 * further commands to be queued to the device. 2140 * @shost: host in question 2141 * 2142 * There is no timer nor any other means by which the requests get unblocked 2143 * other than the low-level driver calling scsi_unblock_requests(). This is done 2144 * as an API function so that changes to the internals of the scsi mid-layer 2145 * won't require wholesale changes to drivers that use this feature. 2146 */ 2147 void scsi_unblock_requests(struct Scsi_Host *shost) 2148 { 2149 shost->host_self_blocked = 0; 2150 scsi_run_host_queues(shost); 2151 } 2152 EXPORT_SYMBOL(scsi_unblock_requests); 2153 2154 void scsi_exit_queue(void) 2155 { 2156 kmem_cache_destroy(scsi_sense_cache); 2157 } 2158 2159 /** 2160 * scsi_mode_select - issue a mode select 2161 * @sdev: SCSI device to be queried 2162 * @pf: Page format bit (1 == standard, 0 == vendor specific) 2163 * @sp: Save page bit (0 == don't save, 1 == save) 2164 * @buffer: request buffer (may not be smaller than eight bytes) 2165 * @len: length of request buffer. 2166 * @timeout: command timeout 2167 * @retries: number of retries before failing 2168 * @data: returns a structure abstracting the mode header data 2169 * @sshdr: place to put sense data (or NULL if no sense to be collected). 2170 * must be SCSI_SENSE_BUFFERSIZE big. 2171 * 2172 * Returns zero if successful; negative error number or scsi 2173 * status on error 2174 * 2175 */ 2176 int scsi_mode_select(struct scsi_device *sdev, int pf, int sp, 2177 unsigned char *buffer, int len, int timeout, int retries, 2178 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) 2179 { 2180 unsigned char cmd[10]; 2181 unsigned char *real_buffer; 2182 const struct scsi_exec_args exec_args = { 2183 .sshdr = sshdr, 2184 }; 2185 int ret; 2186 2187 memset(cmd, 0, sizeof(cmd)); 2188 cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); 2189 2190 /* 2191 * Use MODE SELECT(10) if the device asked for it or if the mode page 2192 * and the mode select header cannot fit within the maximumm 255 bytes 2193 * of the MODE SELECT(6) command. 2194 */ 2195 if (sdev->use_10_for_ms || 2196 len + 4 > 255 || 2197 data->block_descriptor_length > 255) { 2198 if (len > 65535 - 8) 2199 return -EINVAL; 2200 real_buffer = kmalloc(8 + len, GFP_KERNEL); 2201 if (!real_buffer) 2202 return -ENOMEM; 2203 memcpy(real_buffer + 8, buffer, len); 2204 len += 8; 2205 real_buffer[0] = 0; 2206 real_buffer[1] = 0; 2207 real_buffer[2] = data->medium_type; 2208 real_buffer[3] = data->device_specific; 2209 real_buffer[4] = data->longlba ? 0x01 : 0; 2210 real_buffer[5] = 0; 2211 put_unaligned_be16(data->block_descriptor_length, 2212 &real_buffer[6]); 2213 2214 cmd[0] = MODE_SELECT_10; 2215 put_unaligned_be16(len, &cmd[7]); 2216 } else { 2217 if (data->longlba) 2218 return -EINVAL; 2219 2220 real_buffer = kmalloc(4 + len, GFP_KERNEL); 2221 if (!real_buffer) 2222 return -ENOMEM; 2223 memcpy(real_buffer + 4, buffer, len); 2224 len += 4; 2225 real_buffer[0] = 0; 2226 real_buffer[1] = data->medium_type; 2227 real_buffer[2] = data->device_specific; 2228 real_buffer[3] = data->block_descriptor_length; 2229 2230 cmd[0] = MODE_SELECT; 2231 cmd[4] = len; 2232 } 2233 2234 ret = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_OUT, real_buffer, len, 2235 timeout, retries, &exec_args); 2236 kfree(real_buffer); 2237 return ret; 2238 } 2239 EXPORT_SYMBOL_GPL(scsi_mode_select); 2240 2241 /** 2242 * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary. 2243 * @sdev: SCSI device to be queried 2244 * @dbd: set to prevent mode sense from returning block descriptors 2245 * @modepage: mode page being requested 2246 * @subpage: sub-page of the mode page being requested 2247 * @buffer: request buffer (may not be smaller than eight bytes) 2248 * @len: length of request buffer. 2249 * @timeout: command timeout 2250 * @retries: number of retries before failing 2251 * @data: returns a structure abstracting the mode header data 2252 * @sshdr: place to put sense data (or NULL if no sense to be collected). 2253 * must be SCSI_SENSE_BUFFERSIZE big. 2254 * 2255 * Returns zero if successful, or a negative error number on failure 2256 */ 2257 int 2258 scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, int subpage, 2259 unsigned char *buffer, int len, int timeout, int retries, 2260 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) 2261 { 2262 unsigned char cmd[12]; 2263 int use_10_for_ms; 2264 int header_length; 2265 int result; 2266 struct scsi_sense_hdr my_sshdr; 2267 struct scsi_failure failure_defs[] = { 2268 { 2269 .sense = UNIT_ATTENTION, 2270 .asc = SCMD_FAILURE_ASC_ANY, 2271 .ascq = SCMD_FAILURE_ASCQ_ANY, 2272 .allowed = retries, 2273 .result = SAM_STAT_CHECK_CONDITION, 2274 }, 2275 {} 2276 }; 2277 struct scsi_failures failures = { 2278 .failure_definitions = failure_defs, 2279 }; 2280 const struct scsi_exec_args exec_args = { 2281 /* caller might not be interested in sense, but we need it */ 2282 .sshdr = sshdr ? : &my_sshdr, 2283 .failures = &failures, 2284 }; 2285 2286 memset(data, 0, sizeof(*data)); 2287 memset(&cmd[0], 0, 12); 2288 2289 dbd = sdev->set_dbd_for_ms ? 8 : dbd; 2290 cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ 2291 cmd[2] = modepage; 2292 cmd[3] = subpage; 2293 2294 sshdr = exec_args.sshdr; 2295 2296 retry: 2297 use_10_for_ms = sdev->use_10_for_ms || len > 255; 2298 2299 if (use_10_for_ms) { 2300 if (len < 8 || len > 65535) 2301 return -EINVAL; 2302 2303 cmd[0] = MODE_SENSE_10; 2304 put_unaligned_be16(len, &cmd[7]); 2305 header_length = 8; 2306 } else { 2307 if (len < 4) 2308 return -EINVAL; 2309 2310 cmd[0] = MODE_SENSE; 2311 cmd[4] = len; 2312 header_length = 4; 2313 } 2314 2315 memset(buffer, 0, len); 2316 2317 result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, buffer, len, 2318 timeout, retries, &exec_args); 2319 if (result < 0) 2320 return result; 2321 2322 /* This code looks awful: what it's doing is making sure an 2323 * ILLEGAL REQUEST sense return identifies the actual command 2324 * byte as the problem. MODE_SENSE commands can return 2325 * ILLEGAL REQUEST if the code page isn't supported */ 2326 2327 if (!scsi_status_is_good(result)) { 2328 if (scsi_sense_valid(sshdr)) { 2329 if ((sshdr->sense_key == ILLEGAL_REQUEST) && 2330 (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { 2331 /* 2332 * Invalid command operation code: retry using 2333 * MODE SENSE(6) if this was a MODE SENSE(10) 2334 * request, except if the request mode page is 2335 * too large for MODE SENSE single byte 2336 * allocation length field. 2337 */ 2338 if (use_10_for_ms) { 2339 if (len > 255) 2340 return -EIO; 2341 sdev->use_10_for_ms = 0; 2342 goto retry; 2343 } 2344 } 2345 } 2346 return -EIO; 2347 } 2348 if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && 2349 (modepage == 6 || modepage == 8))) { 2350 /* Initio breakage? */ 2351 header_length = 0; 2352 data->length = 13; 2353 data->medium_type = 0; 2354 data->device_specific = 0; 2355 data->longlba = 0; 2356 data->block_descriptor_length = 0; 2357 } else if (use_10_for_ms) { 2358 data->length = get_unaligned_be16(&buffer[0]) + 2; 2359 data->medium_type = buffer[2]; 2360 data->device_specific = buffer[3]; 2361 data->longlba = buffer[4] & 0x01; 2362 data->block_descriptor_length = get_unaligned_be16(&buffer[6]); 2363 } else { 2364 data->length = buffer[0] + 1; 2365 data->medium_type = buffer[1]; 2366 data->device_specific = buffer[2]; 2367 data->block_descriptor_length = buffer[3]; 2368 } 2369 data->header_length = header_length; 2370 2371 return 0; 2372 } 2373 EXPORT_SYMBOL(scsi_mode_sense); 2374 2375 /** 2376 * scsi_test_unit_ready - test if unit is ready 2377 * @sdev: scsi device to change the state of. 2378 * @timeout: command timeout 2379 * @retries: number of retries before failing 2380 * @sshdr: outpout pointer for decoded sense information. 2381 * 2382 * Returns zero if unsuccessful or an error if TUR failed. For 2383 * removable media, UNIT_ATTENTION sets ->changed flag. 2384 **/ 2385 int 2386 scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, 2387 struct scsi_sense_hdr *sshdr) 2388 { 2389 char cmd[] = { 2390 TEST_UNIT_READY, 0, 0, 0, 0, 0, 2391 }; 2392 const struct scsi_exec_args exec_args = { 2393 .sshdr = sshdr, 2394 }; 2395 int result; 2396 2397 /* try to eat the UNIT_ATTENTION if there are enough retries */ 2398 do { 2399 result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, NULL, 0, 2400 timeout, 1, &exec_args); 2401 if (sdev->removable && result > 0 && scsi_sense_valid(sshdr) && 2402 sshdr->sense_key == UNIT_ATTENTION) 2403 sdev->changed = 1; 2404 } while (result > 0 && scsi_sense_valid(sshdr) && 2405 sshdr->sense_key == UNIT_ATTENTION && --retries); 2406 2407 return result; 2408 } 2409 EXPORT_SYMBOL(scsi_test_unit_ready); 2410 2411 /** 2412 * scsi_device_set_state - Take the given device through the device state model. 2413 * @sdev: scsi device to change the state of. 2414 * @state: state to change to. 2415 * 2416 * Returns zero if successful or an error if the requested 2417 * transition is illegal. 2418 */ 2419 int 2420 scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) 2421 { 2422 enum scsi_device_state oldstate = sdev->sdev_state; 2423 2424 if (state == oldstate) 2425 return 0; 2426 2427 switch (state) { 2428 case SDEV_CREATED: 2429 switch (oldstate) { 2430 case SDEV_CREATED_BLOCK: 2431 break; 2432 default: 2433 goto illegal; 2434 } 2435 break; 2436 2437 case SDEV_RUNNING: 2438 switch (oldstate) { 2439 case SDEV_CREATED: 2440 case SDEV_OFFLINE: 2441 case SDEV_TRANSPORT_OFFLINE: 2442 case SDEV_QUIESCE: 2443 case SDEV_BLOCK: 2444 break; 2445 default: 2446 goto illegal; 2447 } 2448 break; 2449 2450 case SDEV_QUIESCE: 2451 switch (oldstate) { 2452 case SDEV_RUNNING: 2453 case SDEV_OFFLINE: 2454 case SDEV_TRANSPORT_OFFLINE: 2455 break; 2456 default: 2457 goto illegal; 2458 } 2459 break; 2460 2461 case SDEV_OFFLINE: 2462 case SDEV_TRANSPORT_OFFLINE: 2463 switch (oldstate) { 2464 case SDEV_CREATED: 2465 case SDEV_RUNNING: 2466 case SDEV_QUIESCE: 2467 case SDEV_BLOCK: 2468 break; 2469 default: 2470 goto illegal; 2471 } 2472 break; 2473 2474 case SDEV_BLOCK: 2475 switch (oldstate) { 2476 case SDEV_RUNNING: 2477 case SDEV_CREATED_BLOCK: 2478 case SDEV_QUIESCE: 2479 case SDEV_OFFLINE: 2480 break; 2481 default: 2482 goto illegal; 2483 } 2484 break; 2485 2486 case SDEV_CREATED_BLOCK: 2487 switch (oldstate) { 2488 case SDEV_CREATED: 2489 break; 2490 default: 2491 goto illegal; 2492 } 2493 break; 2494 2495 case SDEV_CANCEL: 2496 switch (oldstate) { 2497 case SDEV_CREATED: 2498 case SDEV_RUNNING: 2499 case SDEV_QUIESCE: 2500 case SDEV_OFFLINE: 2501 case SDEV_TRANSPORT_OFFLINE: 2502 break; 2503 default: 2504 goto illegal; 2505 } 2506 break; 2507 2508 case SDEV_DEL: 2509 switch (oldstate) { 2510 case SDEV_CREATED: 2511 case SDEV_RUNNING: 2512 case SDEV_OFFLINE: 2513 case SDEV_TRANSPORT_OFFLINE: 2514 case SDEV_CANCEL: 2515 case SDEV_BLOCK: 2516 case SDEV_CREATED_BLOCK: 2517 break; 2518 default: 2519 goto illegal; 2520 } 2521 break; 2522 2523 } 2524 sdev->offline_already = false; 2525 sdev->sdev_state = state; 2526 return 0; 2527 2528 illegal: 2529 SCSI_LOG_ERROR_RECOVERY(1, 2530 sdev_printk(KERN_ERR, sdev, 2531 "Illegal state transition %s->%s", 2532 scsi_device_state_name(oldstate), 2533 scsi_device_state_name(state)) 2534 ); 2535 return -EINVAL; 2536 } 2537 EXPORT_SYMBOL(scsi_device_set_state); 2538 2539 /** 2540 * scsi_evt_emit - emit a single SCSI device uevent 2541 * @sdev: associated SCSI device 2542 * @evt: event to emit 2543 * 2544 * Send a single uevent (scsi_event) to the associated scsi_device. 2545 */ 2546 static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) 2547 { 2548 int idx = 0; 2549 char *envp[3]; 2550 2551 switch (evt->evt_type) { 2552 case SDEV_EVT_MEDIA_CHANGE: 2553 envp[idx++] = "SDEV_MEDIA_CHANGE=1"; 2554 break; 2555 case SDEV_EVT_INQUIRY_CHANGE_REPORTED: 2556 scsi_rescan_device(sdev); 2557 envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED"; 2558 break; 2559 case SDEV_EVT_CAPACITY_CHANGE_REPORTED: 2560 envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED"; 2561 break; 2562 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: 2563 envp[idx++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED"; 2564 break; 2565 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: 2566 envp[idx++] = "SDEV_UA=MODE_PARAMETERS_CHANGED"; 2567 break; 2568 case SDEV_EVT_LUN_CHANGE_REPORTED: 2569 envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED"; 2570 break; 2571 case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED: 2572 envp[idx++] = "SDEV_UA=ASYMMETRIC_ACCESS_STATE_CHANGED"; 2573 break; 2574 case SDEV_EVT_POWER_ON_RESET_OCCURRED: 2575 envp[idx++] = "SDEV_UA=POWER_ON_RESET_OCCURRED"; 2576 break; 2577 default: 2578 /* do nothing */ 2579 break; 2580 } 2581 2582 envp[idx++] = NULL; 2583 2584 kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); 2585 } 2586 2587 /** 2588 * scsi_evt_thread - send a uevent for each scsi event 2589 * @work: work struct for scsi_device 2590 * 2591 * Dispatch queued events to their associated scsi_device kobjects 2592 * as uevents. 2593 */ 2594 void scsi_evt_thread(struct work_struct *work) 2595 { 2596 struct scsi_device *sdev; 2597 enum scsi_device_event evt_type; 2598 LIST_HEAD(event_list); 2599 2600 sdev = container_of(work, struct scsi_device, event_work); 2601 2602 for (evt_type = SDEV_EVT_FIRST; evt_type <= SDEV_EVT_LAST; evt_type++) 2603 if (test_and_clear_bit(evt_type, sdev->pending_events)) 2604 sdev_evt_send_simple(sdev, evt_type, GFP_KERNEL); 2605 2606 while (1) { 2607 struct scsi_event *evt; 2608 struct list_head *this, *tmp; 2609 unsigned long flags; 2610 2611 spin_lock_irqsave(&sdev->list_lock, flags); 2612 list_splice_init(&sdev->event_list, &event_list); 2613 spin_unlock_irqrestore(&sdev->list_lock, flags); 2614 2615 if (list_empty(&event_list)) 2616 break; 2617 2618 list_for_each_safe(this, tmp, &event_list) { 2619 evt = list_entry(this, struct scsi_event, node); 2620 list_del(&evt->node); 2621 scsi_evt_emit(sdev, evt); 2622 kfree(evt); 2623 } 2624 } 2625 } 2626 2627 /** 2628 * sdev_evt_send - send asserted event to uevent thread 2629 * @sdev: scsi_device event occurred on 2630 * @evt: event to send 2631 * 2632 * Assert scsi device event asynchronously. 2633 */ 2634 void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) 2635 { 2636 unsigned long flags; 2637 2638 #if 0 2639 /* FIXME: currently this check eliminates all media change events 2640 * for polled devices. Need to update to discriminate between AN 2641 * and polled events */ 2642 if (!test_bit(evt->evt_type, sdev->supported_events)) { 2643 kfree(evt); 2644 return; 2645 } 2646 #endif 2647 2648 spin_lock_irqsave(&sdev->list_lock, flags); 2649 list_add_tail(&evt->node, &sdev->event_list); 2650 schedule_work(&sdev->event_work); 2651 spin_unlock_irqrestore(&sdev->list_lock, flags); 2652 } 2653 EXPORT_SYMBOL_GPL(sdev_evt_send); 2654 2655 /** 2656 * sdev_evt_alloc - allocate a new scsi event 2657 * @evt_type: type of event to allocate 2658 * @gfpflags: GFP flags for allocation 2659 * 2660 * Allocates and returns a new scsi_event. 2661 */ 2662 struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, 2663 gfp_t gfpflags) 2664 { 2665 struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); 2666 if (!evt) 2667 return NULL; 2668 2669 evt->evt_type = evt_type; 2670 INIT_LIST_HEAD(&evt->node); 2671 2672 /* evt_type-specific initialization, if any */ 2673 switch (evt_type) { 2674 case SDEV_EVT_MEDIA_CHANGE: 2675 case SDEV_EVT_INQUIRY_CHANGE_REPORTED: 2676 case SDEV_EVT_CAPACITY_CHANGE_REPORTED: 2677 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: 2678 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: 2679 case SDEV_EVT_LUN_CHANGE_REPORTED: 2680 case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED: 2681 case SDEV_EVT_POWER_ON_RESET_OCCURRED: 2682 default: 2683 /* do nothing */ 2684 break; 2685 } 2686 2687 return evt; 2688 } 2689 EXPORT_SYMBOL_GPL(sdev_evt_alloc); 2690 2691 /** 2692 * sdev_evt_send_simple - send asserted event to uevent thread 2693 * @sdev: scsi_device event occurred on 2694 * @evt_type: type of event to send 2695 * @gfpflags: GFP flags for allocation 2696 * 2697 * Assert scsi device event asynchronously, given an event type. 2698 */ 2699 void sdev_evt_send_simple(struct scsi_device *sdev, 2700 enum scsi_device_event evt_type, gfp_t gfpflags) 2701 { 2702 struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); 2703 if (!evt) { 2704 sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", 2705 evt_type); 2706 return; 2707 } 2708 2709 sdev_evt_send(sdev, evt); 2710 } 2711 EXPORT_SYMBOL_GPL(sdev_evt_send_simple); 2712 2713 /** 2714 * scsi_device_quiesce - Block all commands except power management. 2715 * @sdev: scsi device to quiesce. 2716 * 2717 * This works by trying to transition to the SDEV_QUIESCE state 2718 * (which must be a legal transition). When the device is in this 2719 * state, only power management requests will be accepted, all others will 2720 * be deferred. 2721 * 2722 * Must be called with user context, may sleep. 2723 * 2724 * Returns zero if unsuccessful or an error if not. 2725 */ 2726 int 2727 scsi_device_quiesce(struct scsi_device *sdev) 2728 { 2729 struct request_queue *q = sdev->request_queue; 2730 int err; 2731 2732 /* 2733 * It is allowed to call scsi_device_quiesce() multiple times from 2734 * the same context but concurrent scsi_device_quiesce() calls are 2735 * not allowed. 2736 */ 2737 WARN_ON_ONCE(sdev->quiesced_by && sdev->quiesced_by != current); 2738 2739 if (sdev->quiesced_by == current) 2740 return 0; 2741 2742 blk_set_pm_only(q); 2743 2744 blk_mq_freeze_queue(q); 2745 /* 2746 * Ensure that the effect of blk_set_pm_only() will be visible 2747 * for percpu_ref_tryget() callers that occur after the queue 2748 * unfreeze even if the queue was already frozen before this function 2749 * was called. See also https://lwn.net/Articles/573497/. 2750 */ 2751 synchronize_rcu(); 2752 blk_mq_unfreeze_queue(q); 2753 2754 mutex_lock(&sdev->state_mutex); 2755 err = scsi_device_set_state(sdev, SDEV_QUIESCE); 2756 if (err == 0) 2757 sdev->quiesced_by = current; 2758 else 2759 blk_clear_pm_only(q); 2760 mutex_unlock(&sdev->state_mutex); 2761 2762 return err; 2763 } 2764 EXPORT_SYMBOL(scsi_device_quiesce); 2765 2766 /** 2767 * scsi_device_resume - Restart user issued commands to a quiesced device. 2768 * @sdev: scsi device to resume. 2769 * 2770 * Moves the device from quiesced back to running and restarts the 2771 * queues. 2772 * 2773 * Must be called with user context, may sleep. 2774 */ 2775 void scsi_device_resume(struct scsi_device *sdev) 2776 { 2777 /* check if the device state was mutated prior to resume, and if 2778 * so assume the state is being managed elsewhere (for example 2779 * device deleted during suspend) 2780 */ 2781 mutex_lock(&sdev->state_mutex); 2782 if (sdev->sdev_state == SDEV_QUIESCE) 2783 scsi_device_set_state(sdev, SDEV_RUNNING); 2784 if (sdev->quiesced_by) { 2785 sdev->quiesced_by = NULL; 2786 blk_clear_pm_only(sdev->request_queue); 2787 } 2788 mutex_unlock(&sdev->state_mutex); 2789 } 2790 EXPORT_SYMBOL(scsi_device_resume); 2791 2792 static void 2793 device_quiesce_fn(struct scsi_device *sdev, void *data) 2794 { 2795 scsi_device_quiesce(sdev); 2796 } 2797 2798 void 2799 scsi_target_quiesce(struct scsi_target *starget) 2800 { 2801 starget_for_each_device(starget, NULL, device_quiesce_fn); 2802 } 2803 EXPORT_SYMBOL(scsi_target_quiesce); 2804 2805 static void 2806 device_resume_fn(struct scsi_device *sdev, void *data) 2807 { 2808 scsi_device_resume(sdev); 2809 } 2810 2811 void 2812 scsi_target_resume(struct scsi_target *starget) 2813 { 2814 starget_for_each_device(starget, NULL, device_resume_fn); 2815 } 2816 EXPORT_SYMBOL(scsi_target_resume); 2817 2818 static int __scsi_internal_device_block_nowait(struct scsi_device *sdev) 2819 { 2820 if (scsi_device_set_state(sdev, SDEV_BLOCK)) 2821 return scsi_device_set_state(sdev, SDEV_CREATED_BLOCK); 2822 2823 return 0; 2824 } 2825 2826 void scsi_start_queue(struct scsi_device *sdev) 2827 { 2828 if (cmpxchg(&sdev->queue_stopped, 1, 0)) 2829 blk_mq_unquiesce_queue(sdev->request_queue); 2830 } 2831 2832 static void scsi_stop_queue(struct scsi_device *sdev) 2833 { 2834 /* 2835 * The atomic variable of ->queue_stopped covers that 2836 * blk_mq_quiesce_queue* is balanced with blk_mq_unquiesce_queue. 2837 * 2838 * The caller needs to wait until quiesce is done. 2839 */ 2840 if (!cmpxchg(&sdev->queue_stopped, 0, 1)) 2841 blk_mq_quiesce_queue_nowait(sdev->request_queue); 2842 } 2843 2844 /** 2845 * scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state 2846 * @sdev: device to block 2847 * 2848 * Pause SCSI command processing on the specified device. Does not sleep. 2849 * 2850 * Returns zero if successful or a negative error code upon failure. 2851 * 2852 * Notes: 2853 * This routine transitions the device to the SDEV_BLOCK state (which must be 2854 * a legal transition). When the device is in this state, command processing 2855 * is paused until the device leaves the SDEV_BLOCK state. See also 2856 * scsi_internal_device_unblock_nowait(). 2857 */ 2858 int scsi_internal_device_block_nowait(struct scsi_device *sdev) 2859 { 2860 int ret = __scsi_internal_device_block_nowait(sdev); 2861 2862 /* 2863 * The device has transitioned to SDEV_BLOCK. Stop the 2864 * block layer from calling the midlayer with this device's 2865 * request queue. 2866 */ 2867 if (!ret) 2868 scsi_stop_queue(sdev); 2869 return ret; 2870 } 2871 EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait); 2872 2873 /** 2874 * scsi_device_block - try to transition to the SDEV_BLOCK state 2875 * @sdev: device to block 2876 * @data: dummy argument, ignored 2877 * 2878 * Pause SCSI command processing on the specified device. Callers must wait 2879 * until all ongoing scsi_queue_rq() calls have finished after this function 2880 * returns. 2881 * 2882 * Note: 2883 * This routine transitions the device to the SDEV_BLOCK state (which must be 2884 * a legal transition). When the device is in this state, command processing 2885 * is paused until the device leaves the SDEV_BLOCK state. See also 2886 * scsi_internal_device_unblock(). 2887 */ 2888 static void scsi_device_block(struct scsi_device *sdev, void *data) 2889 { 2890 int err; 2891 enum scsi_device_state state; 2892 2893 mutex_lock(&sdev->state_mutex); 2894 err = __scsi_internal_device_block_nowait(sdev); 2895 state = sdev->sdev_state; 2896 if (err == 0) 2897 /* 2898 * scsi_stop_queue() must be called with the state_mutex 2899 * held. Otherwise a simultaneous scsi_start_queue() call 2900 * might unquiesce the queue before we quiesce it. 2901 */ 2902 scsi_stop_queue(sdev); 2903 2904 mutex_unlock(&sdev->state_mutex); 2905 2906 WARN_ONCE(err, "%s: failed to block %s in state %d\n", 2907 __func__, dev_name(&sdev->sdev_gendev), state); 2908 } 2909 2910 /** 2911 * scsi_internal_device_unblock_nowait - resume a device after a block request 2912 * @sdev: device to resume 2913 * @new_state: state to set the device to after unblocking 2914 * 2915 * Restart the device queue for a previously suspended SCSI device. Does not 2916 * sleep. 2917 * 2918 * Returns zero if successful or a negative error code upon failure. 2919 * 2920 * Notes: 2921 * This routine transitions the device to the SDEV_RUNNING state or to one of 2922 * the offline states (which must be a legal transition) allowing the midlayer 2923 * to goose the queue for this device. 2924 */ 2925 int scsi_internal_device_unblock_nowait(struct scsi_device *sdev, 2926 enum scsi_device_state new_state) 2927 { 2928 switch (new_state) { 2929 case SDEV_RUNNING: 2930 case SDEV_TRANSPORT_OFFLINE: 2931 break; 2932 default: 2933 return -EINVAL; 2934 } 2935 2936 /* 2937 * Try to transition the scsi device to SDEV_RUNNING or one of the 2938 * offlined states and goose the device queue if successful. 2939 */ 2940 switch (sdev->sdev_state) { 2941 case SDEV_BLOCK: 2942 case SDEV_TRANSPORT_OFFLINE: 2943 sdev->sdev_state = new_state; 2944 break; 2945 case SDEV_CREATED_BLOCK: 2946 if (new_state == SDEV_TRANSPORT_OFFLINE || 2947 new_state == SDEV_OFFLINE) 2948 sdev->sdev_state = new_state; 2949 else 2950 sdev->sdev_state = SDEV_CREATED; 2951 break; 2952 case SDEV_CANCEL: 2953 case SDEV_OFFLINE: 2954 break; 2955 default: 2956 return -EINVAL; 2957 } 2958 scsi_start_queue(sdev); 2959 2960 return 0; 2961 } 2962 EXPORT_SYMBOL_GPL(scsi_internal_device_unblock_nowait); 2963 2964 /** 2965 * scsi_internal_device_unblock - resume a device after a block request 2966 * @sdev: device to resume 2967 * @new_state: state to set the device to after unblocking 2968 * 2969 * Restart the device queue for a previously suspended SCSI device. May sleep. 2970 * 2971 * Returns zero if successful or a negative error code upon failure. 2972 * 2973 * Notes: 2974 * This routine transitions the device to the SDEV_RUNNING state or to one of 2975 * the offline states (which must be a legal transition) allowing the midlayer 2976 * to goose the queue for this device. 2977 */ 2978 static int scsi_internal_device_unblock(struct scsi_device *sdev, 2979 enum scsi_device_state new_state) 2980 { 2981 int ret; 2982 2983 mutex_lock(&sdev->state_mutex); 2984 ret = scsi_internal_device_unblock_nowait(sdev, new_state); 2985 mutex_unlock(&sdev->state_mutex); 2986 2987 return ret; 2988 } 2989 2990 static int 2991 target_block(struct device *dev, void *data) 2992 { 2993 if (scsi_is_target_device(dev)) 2994 starget_for_each_device(to_scsi_target(dev), NULL, 2995 scsi_device_block); 2996 return 0; 2997 } 2998 2999 /** 3000 * scsi_block_targets - transition all SCSI child devices to SDEV_BLOCK state 3001 * @dev: a parent device of one or more scsi_target devices 3002 * @shost: the Scsi_Host to which this device belongs 3003 * 3004 * Iterate over all children of @dev, which should be scsi_target devices, 3005 * and switch all subordinate scsi devices to SDEV_BLOCK state. Wait for 3006 * ongoing scsi_queue_rq() calls to finish. May sleep. 3007 * 3008 * Note: 3009 * @dev must not itself be a scsi_target device. 3010 */ 3011 void 3012 scsi_block_targets(struct Scsi_Host *shost, struct device *dev) 3013 { 3014 WARN_ON_ONCE(scsi_is_target_device(dev)); 3015 device_for_each_child(dev, NULL, target_block); 3016 blk_mq_wait_quiesce_done(&shost->tag_set); 3017 } 3018 EXPORT_SYMBOL_GPL(scsi_block_targets); 3019 3020 static void 3021 device_unblock(struct scsi_device *sdev, void *data) 3022 { 3023 scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data); 3024 } 3025 3026 static int 3027 target_unblock(struct device *dev, void *data) 3028 { 3029 if (scsi_is_target_device(dev)) 3030 starget_for_each_device(to_scsi_target(dev), data, 3031 device_unblock); 3032 return 0; 3033 } 3034 3035 void 3036 scsi_target_unblock(struct device *dev, enum scsi_device_state new_state) 3037 { 3038 if (scsi_is_target_device(dev)) 3039 starget_for_each_device(to_scsi_target(dev), &new_state, 3040 device_unblock); 3041 else 3042 device_for_each_child(dev, &new_state, target_unblock); 3043 } 3044 EXPORT_SYMBOL_GPL(scsi_target_unblock); 3045 3046 /** 3047 * scsi_host_block - Try to transition all logical units to the SDEV_BLOCK state 3048 * @shost: device to block 3049 * 3050 * Pause SCSI command processing for all logical units associated with the SCSI 3051 * host and wait until pending scsi_queue_rq() calls have finished. 3052 * 3053 * Returns zero if successful or a negative error code upon failure. 3054 */ 3055 int 3056 scsi_host_block(struct Scsi_Host *shost) 3057 { 3058 struct scsi_device *sdev; 3059 int ret; 3060 3061 /* 3062 * Call scsi_internal_device_block_nowait so we can avoid 3063 * calling synchronize_rcu() for each LUN. 3064 */ 3065 shost_for_each_device(sdev, shost) { 3066 mutex_lock(&sdev->state_mutex); 3067 ret = scsi_internal_device_block_nowait(sdev); 3068 mutex_unlock(&sdev->state_mutex); 3069 if (ret) { 3070 scsi_device_put(sdev); 3071 return ret; 3072 } 3073 } 3074 3075 /* Wait for ongoing scsi_queue_rq() calls to finish. */ 3076 blk_mq_wait_quiesce_done(&shost->tag_set); 3077 3078 return 0; 3079 } 3080 EXPORT_SYMBOL_GPL(scsi_host_block); 3081 3082 int 3083 scsi_host_unblock(struct Scsi_Host *shost, int new_state) 3084 { 3085 struct scsi_device *sdev; 3086 int ret = 0; 3087 3088 shost_for_each_device(sdev, shost) { 3089 ret = scsi_internal_device_unblock(sdev, new_state); 3090 if (ret) { 3091 scsi_device_put(sdev); 3092 break; 3093 } 3094 } 3095 return ret; 3096 } 3097 EXPORT_SYMBOL_GPL(scsi_host_unblock); 3098 3099 /** 3100 * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt 3101 * @sgl: scatter-gather list 3102 * @sg_count: number of segments in sg 3103 * @offset: offset in bytes into sg, on return offset into the mapped area 3104 * @len: bytes to map, on return number of bytes mapped 3105 * 3106 * Returns virtual address of the start of the mapped page 3107 */ 3108 void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count, 3109 size_t *offset, size_t *len) 3110 { 3111 int i; 3112 size_t sg_len = 0, len_complete = 0; 3113 struct scatterlist *sg; 3114 struct page *page; 3115 3116 WARN_ON(!irqs_disabled()); 3117 3118 for_each_sg(sgl, sg, sg_count, i) { 3119 len_complete = sg_len; /* Complete sg-entries */ 3120 sg_len += sg->length; 3121 if (sg_len > *offset) 3122 break; 3123 } 3124 3125 if (unlikely(i == sg_count)) { 3126 printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " 3127 "elements %d\n", 3128 __func__, sg_len, *offset, sg_count); 3129 WARN_ON(1); 3130 return NULL; 3131 } 3132 3133 /* Offset starting from the beginning of first page in this sg-entry */ 3134 *offset = *offset - len_complete + sg->offset; 3135 3136 /* Assumption: contiguous pages can be accessed as "page + i" */ 3137 page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT)); 3138 *offset &= ~PAGE_MASK; 3139 3140 /* Bytes in this sg-entry from *offset to the end of the page */ 3141 sg_len = PAGE_SIZE - *offset; 3142 if (*len > sg_len) 3143 *len = sg_len; 3144 3145 return kmap_atomic(page); 3146 } 3147 EXPORT_SYMBOL(scsi_kmap_atomic_sg); 3148 3149 /** 3150 * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg 3151 * @virt: virtual address to be unmapped 3152 */ 3153 void scsi_kunmap_atomic_sg(void *virt) 3154 { 3155 kunmap_atomic(virt); 3156 } 3157 EXPORT_SYMBOL(scsi_kunmap_atomic_sg); 3158 3159 void sdev_disable_disk_events(struct scsi_device *sdev) 3160 { 3161 atomic_inc(&sdev->disk_events_disable_depth); 3162 } 3163 EXPORT_SYMBOL(sdev_disable_disk_events); 3164 3165 void sdev_enable_disk_events(struct scsi_device *sdev) 3166 { 3167 if (WARN_ON_ONCE(atomic_read(&sdev->disk_events_disable_depth) <= 0)) 3168 return; 3169 atomic_dec(&sdev->disk_events_disable_depth); 3170 } 3171 EXPORT_SYMBOL(sdev_enable_disk_events); 3172 3173 static unsigned char designator_prio(const unsigned char *d) 3174 { 3175 if (d[1] & 0x30) 3176 /* not associated with LUN */ 3177 return 0; 3178 3179 if (d[3] == 0) 3180 /* invalid length */ 3181 return 0; 3182 3183 /* 3184 * Order of preference for lun descriptor: 3185 * - SCSI name string 3186 * - NAA IEEE Registered Extended 3187 * - EUI-64 based 16-byte 3188 * - EUI-64 based 12-byte 3189 * - NAA IEEE Registered 3190 * - NAA IEEE Extended 3191 * - EUI-64 based 8-byte 3192 * - SCSI name string (truncated) 3193 * - T10 Vendor ID 3194 * as longer descriptors reduce the likelyhood 3195 * of identification clashes. 3196 */ 3197 3198 switch (d[1] & 0xf) { 3199 case 8: 3200 /* SCSI name string, variable-length UTF-8 */ 3201 return 9; 3202 case 3: 3203 switch (d[4] >> 4) { 3204 case 6: 3205 /* NAA registered extended */ 3206 return 8; 3207 case 5: 3208 /* NAA registered */ 3209 return 5; 3210 case 4: 3211 /* NAA extended */ 3212 return 4; 3213 case 3: 3214 /* NAA locally assigned */ 3215 return 1; 3216 default: 3217 break; 3218 } 3219 break; 3220 case 2: 3221 switch (d[3]) { 3222 case 16: 3223 /* EUI64-based, 16 byte */ 3224 return 7; 3225 case 12: 3226 /* EUI64-based, 12 byte */ 3227 return 6; 3228 case 8: 3229 /* EUI64-based, 8 byte */ 3230 return 3; 3231 default: 3232 break; 3233 } 3234 break; 3235 case 1: 3236 /* T10 vendor ID */ 3237 return 1; 3238 default: 3239 break; 3240 } 3241 3242 return 0; 3243 } 3244 3245 /** 3246 * scsi_vpd_lun_id - return a unique device identification 3247 * @sdev: SCSI device 3248 * @id: buffer for the identification 3249 * @id_len: length of the buffer 3250 * 3251 * Copies a unique device identification into @id based 3252 * on the information in the VPD page 0x83 of the device. 3253 * The string will be formatted as a SCSI name string. 3254 * 3255 * Returns the length of the identification or error on failure. 3256 * If the identifier is longer than the supplied buffer the actual 3257 * identifier length is returned and the buffer is not zero-padded. 3258 */ 3259 int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len) 3260 { 3261 u8 cur_id_prio = 0; 3262 u8 cur_id_size = 0; 3263 const unsigned char *d, *cur_id_str; 3264 const struct scsi_vpd *vpd_pg83; 3265 int id_size = -EINVAL; 3266 3267 rcu_read_lock(); 3268 vpd_pg83 = rcu_dereference(sdev->vpd_pg83); 3269 if (!vpd_pg83) { 3270 rcu_read_unlock(); 3271 return -ENXIO; 3272 } 3273 3274 /* The id string must be at least 20 bytes + terminating NULL byte */ 3275 if (id_len < 21) { 3276 rcu_read_unlock(); 3277 return -EINVAL; 3278 } 3279 3280 memset(id, 0, id_len); 3281 for (d = vpd_pg83->data + 4; 3282 d < vpd_pg83->data + vpd_pg83->len; 3283 d += d[3] + 4) { 3284 u8 prio = designator_prio(d); 3285 3286 if (prio == 0 || cur_id_prio > prio) 3287 continue; 3288 3289 switch (d[1] & 0xf) { 3290 case 0x1: 3291 /* T10 Vendor ID */ 3292 if (cur_id_size > d[3]) 3293 break; 3294 cur_id_prio = prio; 3295 cur_id_size = d[3]; 3296 if (cur_id_size + 4 > id_len) 3297 cur_id_size = id_len - 4; 3298 cur_id_str = d + 4; 3299 id_size = snprintf(id, id_len, "t10.%*pE", 3300 cur_id_size, cur_id_str); 3301 break; 3302 case 0x2: 3303 /* EUI-64 */ 3304 cur_id_prio = prio; 3305 cur_id_size = d[3]; 3306 cur_id_str = d + 4; 3307 switch (cur_id_size) { 3308 case 8: 3309 id_size = snprintf(id, id_len, 3310 "eui.%8phN", 3311 cur_id_str); 3312 break; 3313 case 12: 3314 id_size = snprintf(id, id_len, 3315 "eui.%12phN", 3316 cur_id_str); 3317 break; 3318 case 16: 3319 id_size = snprintf(id, id_len, 3320 "eui.%16phN", 3321 cur_id_str); 3322 break; 3323 default: 3324 break; 3325 } 3326 break; 3327 case 0x3: 3328 /* NAA */ 3329 cur_id_prio = prio; 3330 cur_id_size = d[3]; 3331 cur_id_str = d + 4; 3332 switch (cur_id_size) { 3333 case 8: 3334 id_size = snprintf(id, id_len, 3335 "naa.%8phN", 3336 cur_id_str); 3337 break; 3338 case 16: 3339 id_size = snprintf(id, id_len, 3340 "naa.%16phN", 3341 cur_id_str); 3342 break; 3343 default: 3344 break; 3345 } 3346 break; 3347 case 0x8: 3348 /* SCSI name string */ 3349 if (cur_id_size > d[3]) 3350 break; 3351 /* Prefer others for truncated descriptor */ 3352 if (d[3] > id_len) { 3353 prio = 2; 3354 if (cur_id_prio > prio) 3355 break; 3356 } 3357 cur_id_prio = prio; 3358 cur_id_size = id_size = d[3]; 3359 cur_id_str = d + 4; 3360 if (cur_id_size >= id_len) 3361 cur_id_size = id_len - 1; 3362 memcpy(id, cur_id_str, cur_id_size); 3363 break; 3364 default: 3365 break; 3366 } 3367 } 3368 rcu_read_unlock(); 3369 3370 return id_size; 3371 } 3372 EXPORT_SYMBOL(scsi_vpd_lun_id); 3373 3374 /* 3375 * scsi_vpd_tpg_id - return a target port group identifier 3376 * @sdev: SCSI device 3377 * 3378 * Returns the Target Port Group identifier from the information 3379 * froom VPD page 0x83 of the device. 3380 * 3381 * Returns the identifier or error on failure. 3382 */ 3383 int scsi_vpd_tpg_id(struct scsi_device *sdev, int *rel_id) 3384 { 3385 const unsigned char *d; 3386 const struct scsi_vpd *vpd_pg83; 3387 int group_id = -EAGAIN, rel_port = -1; 3388 3389 rcu_read_lock(); 3390 vpd_pg83 = rcu_dereference(sdev->vpd_pg83); 3391 if (!vpd_pg83) { 3392 rcu_read_unlock(); 3393 return -ENXIO; 3394 } 3395 3396 d = vpd_pg83->data + 4; 3397 while (d < vpd_pg83->data + vpd_pg83->len) { 3398 switch (d[1] & 0xf) { 3399 case 0x4: 3400 /* Relative target port */ 3401 rel_port = get_unaligned_be16(&d[6]); 3402 break; 3403 case 0x5: 3404 /* Target port group */ 3405 group_id = get_unaligned_be16(&d[6]); 3406 break; 3407 default: 3408 break; 3409 } 3410 d += d[3] + 4; 3411 } 3412 rcu_read_unlock(); 3413 3414 if (group_id >= 0 && rel_id && rel_port != -1) 3415 *rel_id = rel_port; 3416 3417 return group_id; 3418 } 3419 EXPORT_SYMBOL(scsi_vpd_tpg_id); 3420 3421 /** 3422 * scsi_build_sense - build sense data for a command 3423 * @scmd: scsi command for which the sense should be formatted 3424 * @desc: Sense format (non-zero == descriptor format, 3425 * 0 == fixed format) 3426 * @key: Sense key 3427 * @asc: Additional sense code 3428 * @ascq: Additional sense code qualifier 3429 * 3430 **/ 3431 void scsi_build_sense(struct scsi_cmnd *scmd, int desc, u8 key, u8 asc, u8 ascq) 3432 { 3433 scsi_build_sense_buffer(desc, scmd->sense_buffer, key, asc, ascq); 3434 scmd->result = SAM_STAT_CHECK_CONDITION; 3435 } 3436 EXPORT_SYMBOL_GPL(scsi_build_sense); 3437 3438 #ifdef CONFIG_SCSI_LIB_KUNIT_TEST 3439 #include "scsi_lib_test.c" 3440 #endif 3441