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_queue() */ 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 // XXX: 635 if (blk_queue_add_random(q)) 636 add_disk_randomness(req->q->disk); 637 638 WARN_ON_ONCE(!blk_rq_is_passthrough(req) && 639 !(cmd->flags & SCMD_INITIALIZED)); 640 cmd->flags = 0; 641 642 /* 643 * Calling rcu_barrier() is not necessary here because the 644 * SCSI error handler guarantees that the function called by 645 * call_rcu() has been called before scsi_end_request() is 646 * called. 647 */ 648 destroy_rcu_head(&cmd->rcu); 649 650 /* 651 * In the MQ case the command gets freed by __blk_mq_end_request, 652 * so we have to do all cleanup that depends on it earlier. 653 * 654 * We also can't kick the queues from irq context, so we 655 * will have to defer it to a workqueue. 656 */ 657 scsi_mq_uninit_cmd(cmd); 658 659 /* 660 * queue is still alive, so grab the ref for preventing it 661 * from being cleaned up during running queue. 662 */ 663 percpu_ref_get(&q->q_usage_counter); 664 665 __blk_mq_end_request(req, error); 666 667 scsi_run_queue_async(sdev); 668 669 percpu_ref_put(&q->q_usage_counter); 670 return false; 671 } 672 673 /** 674 * scsi_result_to_blk_status - translate a SCSI result code into blk_status_t 675 * @result: scsi error code 676 * 677 * Translate a SCSI result code into a blk_status_t value. 678 */ 679 static blk_status_t scsi_result_to_blk_status(int result) 680 { 681 /* 682 * Check the scsi-ml byte first in case we converted a host or status 683 * byte. 684 */ 685 switch (scsi_ml_byte(result)) { 686 case SCSIML_STAT_OK: 687 break; 688 case SCSIML_STAT_RESV_CONFLICT: 689 return BLK_STS_RESV_CONFLICT; 690 case SCSIML_STAT_NOSPC: 691 return BLK_STS_NOSPC; 692 case SCSIML_STAT_MED_ERROR: 693 return BLK_STS_MEDIUM; 694 case SCSIML_STAT_TGT_FAILURE: 695 return BLK_STS_TARGET; 696 case SCSIML_STAT_DL_TIMEOUT: 697 return BLK_STS_DURATION_LIMIT; 698 } 699 700 switch (host_byte(result)) { 701 case DID_OK: 702 if (scsi_status_is_good(result)) 703 return BLK_STS_OK; 704 return BLK_STS_IOERR; 705 case DID_TRANSPORT_FAILFAST: 706 case DID_TRANSPORT_MARGINAL: 707 return BLK_STS_TRANSPORT; 708 default: 709 return BLK_STS_IOERR; 710 } 711 } 712 713 /** 714 * scsi_rq_err_bytes - determine number of bytes till the next failure boundary 715 * @rq: request to examine 716 * 717 * Description: 718 * A request could be merge of IOs which require different failure 719 * handling. This function determines the number of bytes which 720 * can be failed from the beginning of the request without 721 * crossing into area which need to be retried further. 722 * 723 * Return: 724 * The number of bytes to fail. 725 */ 726 static unsigned int scsi_rq_err_bytes(const struct request *rq) 727 { 728 blk_opf_t ff = rq->cmd_flags & REQ_FAILFAST_MASK; 729 unsigned int bytes = 0; 730 struct bio *bio; 731 732 if (!(rq->rq_flags & RQF_MIXED_MERGE)) 733 return blk_rq_bytes(rq); 734 735 /* 736 * Currently the only 'mixing' which can happen is between 737 * different fastfail types. We can safely fail portions 738 * which have all the failfast bits that the first one has - 739 * the ones which are at least as eager to fail as the first 740 * one. 741 */ 742 for (bio = rq->bio; bio; bio = bio->bi_next) { 743 if ((bio->bi_opf & ff) != ff) 744 break; 745 bytes += bio->bi_iter.bi_size; 746 } 747 748 /* this could lead to infinite loop */ 749 BUG_ON(blk_rq_bytes(rq) && !bytes); 750 return bytes; 751 } 752 753 static bool scsi_cmd_runtime_exceeced(struct scsi_cmnd *cmd) 754 { 755 struct request *req = scsi_cmd_to_rq(cmd); 756 unsigned long wait_for; 757 758 if (cmd->allowed == SCSI_CMD_RETRIES_NO_LIMIT) 759 return false; 760 761 wait_for = (cmd->allowed + 1) * req->timeout; 762 if (time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { 763 scmd_printk(KERN_ERR, cmd, "timing out command, waited %lus\n", 764 wait_for/HZ); 765 return true; 766 } 767 return false; 768 } 769 770 /* 771 * When ALUA transition state is returned, reprep the cmd to 772 * use the ALUA handler's transition timeout. Delay the reprep 773 * 1 sec to avoid aggressive retries of the target in that 774 * state. 775 */ 776 #define ALUA_TRANSITION_REPREP_DELAY 1000 777 778 /* Helper for scsi_io_completion() when special action required. */ 779 static void scsi_io_completion_action(struct scsi_cmnd *cmd, int result) 780 { 781 struct request *req = scsi_cmd_to_rq(cmd); 782 int level = 0; 783 enum {ACTION_FAIL, ACTION_REPREP, ACTION_DELAYED_REPREP, 784 ACTION_RETRY, ACTION_DELAYED_RETRY} action; 785 struct scsi_sense_hdr sshdr; 786 bool sense_valid; 787 bool sense_current = true; /* false implies "deferred sense" */ 788 blk_status_t blk_stat; 789 790 sense_valid = scsi_command_normalize_sense(cmd, &sshdr); 791 if (sense_valid) 792 sense_current = !scsi_sense_is_deferred(&sshdr); 793 794 blk_stat = scsi_result_to_blk_status(result); 795 796 if (host_byte(result) == DID_RESET) { 797 /* Third party bus reset or reset for error recovery 798 * reasons. Just retry the command and see what 799 * happens. 800 */ 801 action = ACTION_RETRY; 802 } else if (sense_valid && sense_current) { 803 switch (sshdr.sense_key) { 804 case UNIT_ATTENTION: 805 if (cmd->device->removable) { 806 /* Detected disc change. Set a bit 807 * and quietly refuse further access. 808 */ 809 cmd->device->changed = 1; 810 action = ACTION_FAIL; 811 } else { 812 /* Must have been a power glitch, or a 813 * bus reset. Could not have been a 814 * media change, so we just retry the 815 * command and see what happens. 816 */ 817 action = ACTION_RETRY; 818 } 819 break; 820 case ILLEGAL_REQUEST: 821 /* If we had an ILLEGAL REQUEST returned, then 822 * we may have performed an unsupported 823 * command. The only thing this should be 824 * would be a ten byte read where only a six 825 * byte read was supported. Also, on a system 826 * where READ CAPACITY failed, we may have 827 * read past the end of the disk. 828 */ 829 if ((cmd->device->use_10_for_rw && 830 sshdr.asc == 0x20 && sshdr.ascq == 0x00) && 831 (cmd->cmnd[0] == READ_10 || 832 cmd->cmnd[0] == WRITE_10)) { 833 /* This will issue a new 6-byte command. */ 834 cmd->device->use_10_for_rw = 0; 835 action = ACTION_REPREP; 836 } else if (sshdr.asc == 0x10) /* DIX */ { 837 action = ACTION_FAIL; 838 blk_stat = BLK_STS_PROTECTION; 839 /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */ 840 } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) { 841 action = ACTION_FAIL; 842 blk_stat = BLK_STS_TARGET; 843 } else 844 action = ACTION_FAIL; 845 break; 846 case ABORTED_COMMAND: 847 action = ACTION_FAIL; 848 if (sshdr.asc == 0x10) /* DIF */ 849 blk_stat = BLK_STS_PROTECTION; 850 break; 851 case NOT_READY: 852 /* If the device is in the process of becoming 853 * ready, or has a temporary blockage, retry. 854 */ 855 if (sshdr.asc == 0x04) { 856 switch (sshdr.ascq) { 857 case 0x01: /* becoming ready */ 858 case 0x04: /* format in progress */ 859 case 0x05: /* rebuild in progress */ 860 case 0x06: /* recalculation in progress */ 861 case 0x07: /* operation in progress */ 862 case 0x08: /* Long write in progress */ 863 case 0x09: /* self test in progress */ 864 case 0x11: /* notify (enable spinup) required */ 865 case 0x14: /* space allocation in progress */ 866 case 0x1a: /* start stop unit in progress */ 867 case 0x1b: /* sanitize in progress */ 868 case 0x1d: /* configuration in progress */ 869 case 0x24: /* depopulation in progress */ 870 case 0x25: /* depopulation restore in progress */ 871 action = ACTION_DELAYED_RETRY; 872 break; 873 case 0x0a: /* ALUA state transition */ 874 action = ACTION_DELAYED_REPREP; 875 break; 876 default: 877 action = ACTION_FAIL; 878 break; 879 } 880 } else 881 action = ACTION_FAIL; 882 break; 883 case VOLUME_OVERFLOW: 884 /* See SSC3rXX or current. */ 885 action = ACTION_FAIL; 886 break; 887 case DATA_PROTECT: 888 action = ACTION_FAIL; 889 if ((sshdr.asc == 0x0C && sshdr.ascq == 0x12) || 890 (sshdr.asc == 0x55 && 891 (sshdr.ascq == 0x0E || sshdr.ascq == 0x0F))) { 892 /* Insufficient zone resources */ 893 blk_stat = BLK_STS_ZONE_OPEN_RESOURCE; 894 } 895 break; 896 case COMPLETED: 897 fallthrough; 898 default: 899 action = ACTION_FAIL; 900 break; 901 } 902 } else 903 action = ACTION_FAIL; 904 905 if (action != ACTION_FAIL && scsi_cmd_runtime_exceeced(cmd)) 906 action = ACTION_FAIL; 907 908 switch (action) { 909 case ACTION_FAIL: 910 /* Give up and fail the remainder of the request */ 911 if (!(req->rq_flags & RQF_QUIET)) { 912 static DEFINE_RATELIMIT_STATE(_rs, 913 DEFAULT_RATELIMIT_INTERVAL, 914 DEFAULT_RATELIMIT_BURST); 915 916 if (unlikely(scsi_logging_level)) 917 level = 918 SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, 919 SCSI_LOG_MLCOMPLETE_BITS); 920 921 /* 922 * if logging is enabled the failure will be printed 923 * in scsi_log_completion(), so avoid duplicate messages 924 */ 925 if (!level && __ratelimit(&_rs)) { 926 scsi_print_result(cmd, NULL, FAILED); 927 if (sense_valid) 928 scsi_print_sense(cmd); 929 scsi_print_command(cmd); 930 } 931 } 932 if (!scsi_end_request(req, blk_stat, scsi_rq_err_bytes(req))) 933 return; 934 fallthrough; 935 case ACTION_REPREP: 936 scsi_mq_requeue_cmd(cmd, 0); 937 break; 938 case ACTION_DELAYED_REPREP: 939 scsi_mq_requeue_cmd(cmd, ALUA_TRANSITION_REPREP_DELAY); 940 break; 941 case ACTION_RETRY: 942 /* Retry the same command immediately */ 943 __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, false); 944 break; 945 case ACTION_DELAYED_RETRY: 946 /* Retry the same command after a delay */ 947 __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, false); 948 break; 949 } 950 } 951 952 /* 953 * Helper for scsi_io_completion() when cmd->result is non-zero. Returns a 954 * new result that may suppress further error checking. Also modifies 955 * *blk_statp in some cases. 956 */ 957 static int scsi_io_completion_nz_result(struct scsi_cmnd *cmd, int result, 958 blk_status_t *blk_statp) 959 { 960 bool sense_valid; 961 bool sense_current = true; /* false implies "deferred sense" */ 962 struct request *req = scsi_cmd_to_rq(cmd); 963 struct scsi_sense_hdr sshdr; 964 965 sense_valid = scsi_command_normalize_sense(cmd, &sshdr); 966 if (sense_valid) 967 sense_current = !scsi_sense_is_deferred(&sshdr); 968 969 if (blk_rq_is_passthrough(req)) { 970 if (sense_valid) { 971 /* 972 * SG_IO wants current and deferred errors 973 */ 974 cmd->sense_len = min(8 + cmd->sense_buffer[7], 975 SCSI_SENSE_BUFFERSIZE); 976 } 977 if (sense_current) 978 *blk_statp = scsi_result_to_blk_status(result); 979 } else if (blk_rq_bytes(req) == 0 && sense_current) { 980 /* 981 * Flush commands do not transfers any data, and thus cannot use 982 * good_bytes != blk_rq_bytes(req) as the signal for an error. 983 * This sets *blk_statp explicitly for the problem case. 984 */ 985 *blk_statp = scsi_result_to_blk_status(result); 986 } 987 /* 988 * Recovered errors need reporting, but they're always treated as 989 * success, so fiddle the result code here. For passthrough requests 990 * we already took a copy of the original into sreq->result which 991 * is what gets returned to the user 992 */ 993 if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) { 994 bool do_print = true; 995 /* 996 * if ATA PASS-THROUGH INFORMATION AVAILABLE [0x0, 0x1d] 997 * skip print since caller wants ATA registers. Only occurs 998 * on SCSI ATA PASS_THROUGH commands when CK_COND=1 999 */ 1000 if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d)) 1001 do_print = false; 1002 else if (req->rq_flags & RQF_QUIET) 1003 do_print = false; 1004 if (do_print) 1005 scsi_print_sense(cmd); 1006 result = 0; 1007 /* for passthrough, *blk_statp may be set */ 1008 *blk_statp = BLK_STS_OK; 1009 } 1010 /* 1011 * Another corner case: the SCSI status byte is non-zero but 'good'. 1012 * Example: PRE-FETCH command returns SAM_STAT_CONDITION_MET when 1013 * it is able to fit nominated LBs in its cache (and SAM_STAT_GOOD 1014 * if it can't fit). Treat SAM_STAT_CONDITION_MET and the related 1015 * intermediate statuses (both obsolete in SAM-4) as good. 1016 */ 1017 if ((result & 0xff) && scsi_status_is_good(result)) { 1018 result = 0; 1019 *blk_statp = BLK_STS_OK; 1020 } 1021 return result; 1022 } 1023 1024 /** 1025 * scsi_io_completion - Completion processing for SCSI commands. 1026 * @cmd: command that is finished. 1027 * @good_bytes: number of processed bytes. 1028 * 1029 * We will finish off the specified number of sectors. If we are done, the 1030 * command block will be released and the queue function will be goosed. If we 1031 * are not done then we have to figure out what to do next: 1032 * 1033 * a) We can call scsi_mq_requeue_cmd(). The request will be 1034 * unprepared and put back on the queue. Then a new command will 1035 * be created for it. This should be used if we made forward 1036 * progress, or if we want to switch from READ(10) to READ(6) for 1037 * example. 1038 * 1039 * b) We can call scsi_io_completion_action(). The request will be 1040 * put back on the queue and retried using the same command as 1041 * before, possibly after a delay. 1042 * 1043 * c) We can call scsi_end_request() with blk_stat other than 1044 * BLK_STS_OK, to fail the remainder of the request. 1045 */ 1046 void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) 1047 { 1048 int result = cmd->result; 1049 struct request *req = scsi_cmd_to_rq(cmd); 1050 blk_status_t blk_stat = BLK_STS_OK; 1051 1052 if (unlikely(result)) /* a nz result may or may not be an error */ 1053 result = scsi_io_completion_nz_result(cmd, result, &blk_stat); 1054 1055 /* 1056 * Next deal with any sectors which we were able to correctly 1057 * handle. 1058 */ 1059 SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, cmd, 1060 "%u sectors total, %d bytes done.\n", 1061 blk_rq_sectors(req), good_bytes)); 1062 1063 /* 1064 * Failed, zero length commands always need to drop down 1065 * to retry code. Fast path should return in this block. 1066 */ 1067 if (likely(blk_rq_bytes(req) > 0 || blk_stat == BLK_STS_OK)) { 1068 if (likely(!scsi_end_request(req, blk_stat, good_bytes))) 1069 return; /* no bytes remaining */ 1070 } 1071 1072 /* Kill remainder if no retries. */ 1073 if (unlikely(blk_stat && scsi_noretry_cmd(cmd))) { 1074 if (scsi_end_request(req, blk_stat, blk_rq_bytes(req))) 1075 WARN_ONCE(true, 1076 "Bytes remaining after failed, no-retry command"); 1077 return; 1078 } 1079 1080 /* 1081 * If there had been no error, but we have leftover bytes in the 1082 * request just queue the command up again. 1083 */ 1084 if (likely(result == 0)) 1085 scsi_mq_requeue_cmd(cmd, 0); 1086 else 1087 scsi_io_completion_action(cmd, result); 1088 } 1089 1090 static inline bool scsi_cmd_needs_dma_drain(struct scsi_device *sdev, 1091 struct request *rq) 1092 { 1093 return sdev->dma_drain_len && blk_rq_is_passthrough(rq) && 1094 !op_is_write(req_op(rq)) && 1095 sdev->host->hostt->dma_need_drain(rq); 1096 } 1097 1098 /** 1099 * scsi_alloc_sgtables - Allocate and initialize data and integrity scatterlists 1100 * @cmd: SCSI command data structure to initialize. 1101 * 1102 * Initializes @cmd->sdb and also @cmd->prot_sdb if data integrity is enabled 1103 * for @cmd. 1104 * 1105 * Returns: 1106 * * BLK_STS_OK - on success 1107 * * BLK_STS_RESOURCE - if the failure is retryable 1108 * * BLK_STS_IOERR - if the failure is fatal 1109 */ 1110 blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd) 1111 { 1112 struct scsi_device *sdev = cmd->device; 1113 struct request *rq = scsi_cmd_to_rq(cmd); 1114 unsigned short nr_segs = blk_rq_nr_phys_segments(rq); 1115 struct scatterlist *last_sg = NULL; 1116 blk_status_t ret; 1117 bool need_drain = scsi_cmd_needs_dma_drain(sdev, rq); 1118 int count; 1119 1120 if (WARN_ON_ONCE(!nr_segs)) 1121 return BLK_STS_IOERR; 1122 1123 /* 1124 * Make sure there is space for the drain. The driver must adjust 1125 * max_hw_segments to be prepared for this. 1126 */ 1127 if (need_drain) 1128 nr_segs++; 1129 1130 /* 1131 * If sg table allocation fails, requeue request later. 1132 */ 1133 if (unlikely(sg_alloc_table_chained(&cmd->sdb.table, nr_segs, 1134 cmd->sdb.table.sgl, SCSI_INLINE_SG_CNT))) 1135 return BLK_STS_RESOURCE; 1136 1137 /* 1138 * Next, walk the list, and fill in the addresses and sizes of 1139 * each segment. 1140 */ 1141 count = __blk_rq_map_sg(rq->q, rq, cmd->sdb.table.sgl, &last_sg); 1142 1143 if (blk_rq_bytes(rq) & rq->q->dma_pad_mask) { 1144 unsigned int pad_len = 1145 (rq->q->dma_pad_mask & ~blk_rq_bytes(rq)) + 1; 1146 1147 last_sg->length += pad_len; 1148 cmd->extra_len += pad_len; 1149 } 1150 1151 if (need_drain) { 1152 sg_unmark_end(last_sg); 1153 last_sg = sg_next(last_sg); 1154 sg_set_buf(last_sg, sdev->dma_drain_buf, sdev->dma_drain_len); 1155 sg_mark_end(last_sg); 1156 1157 cmd->extra_len += sdev->dma_drain_len; 1158 count++; 1159 } 1160 1161 BUG_ON(count > cmd->sdb.table.nents); 1162 cmd->sdb.table.nents = count; 1163 cmd->sdb.length = blk_rq_payload_bytes(rq); 1164 1165 if (blk_integrity_rq(rq)) { 1166 struct scsi_data_buffer *prot_sdb = cmd->prot_sdb; 1167 int ivecs; 1168 1169 if (WARN_ON_ONCE(!prot_sdb)) { 1170 /* 1171 * This can happen if someone (e.g. multipath) 1172 * queues a command to a device on an adapter 1173 * that does not support DIX. 1174 */ 1175 ret = BLK_STS_IOERR; 1176 goto out_free_sgtables; 1177 } 1178 1179 ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio); 1180 1181 if (sg_alloc_table_chained(&prot_sdb->table, ivecs, 1182 prot_sdb->table.sgl, 1183 SCSI_INLINE_PROT_SG_CNT)) { 1184 ret = BLK_STS_RESOURCE; 1185 goto out_free_sgtables; 1186 } 1187 1188 count = blk_rq_map_integrity_sg(rq->q, rq->bio, 1189 prot_sdb->table.sgl); 1190 BUG_ON(count > ivecs); 1191 BUG_ON(count > queue_max_integrity_segments(rq->q)); 1192 1193 cmd->prot_sdb = prot_sdb; 1194 cmd->prot_sdb->table.nents = count; 1195 } 1196 1197 return BLK_STS_OK; 1198 out_free_sgtables: 1199 scsi_free_sgtables(cmd); 1200 return ret; 1201 } 1202 EXPORT_SYMBOL(scsi_alloc_sgtables); 1203 1204 /** 1205 * scsi_initialize_rq - initialize struct scsi_cmnd partially 1206 * @rq: Request associated with the SCSI command to be initialized. 1207 * 1208 * This function initializes the members of struct scsi_cmnd that must be 1209 * initialized before request processing starts and that won't be 1210 * reinitialized if a SCSI command is requeued. 1211 */ 1212 static void scsi_initialize_rq(struct request *rq) 1213 { 1214 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); 1215 1216 memset(cmd->cmnd, 0, sizeof(cmd->cmnd)); 1217 cmd->cmd_len = MAX_COMMAND_SIZE; 1218 cmd->sense_len = 0; 1219 init_rcu_head(&cmd->rcu); 1220 cmd->jiffies_at_alloc = jiffies; 1221 cmd->retries = 0; 1222 } 1223 1224 struct request *scsi_alloc_request(struct request_queue *q, blk_opf_t opf, 1225 blk_mq_req_flags_t flags) 1226 { 1227 struct request *rq; 1228 1229 rq = blk_mq_alloc_request(q, opf, flags); 1230 if (!IS_ERR(rq)) 1231 scsi_initialize_rq(rq); 1232 return rq; 1233 } 1234 EXPORT_SYMBOL_GPL(scsi_alloc_request); 1235 1236 /* 1237 * Only called when the request isn't completed by SCSI, and not freed by 1238 * SCSI 1239 */ 1240 static void scsi_cleanup_rq(struct request *rq) 1241 { 1242 if (rq->rq_flags & RQF_DONTPREP) { 1243 scsi_mq_uninit_cmd(blk_mq_rq_to_pdu(rq)); 1244 rq->rq_flags &= ~RQF_DONTPREP; 1245 } 1246 } 1247 1248 /* Called before a request is prepared. See also scsi_mq_prep_fn(). */ 1249 void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd) 1250 { 1251 struct request *rq = scsi_cmd_to_rq(cmd); 1252 1253 if (!blk_rq_is_passthrough(rq) && !(cmd->flags & SCMD_INITIALIZED)) { 1254 cmd->flags |= SCMD_INITIALIZED; 1255 scsi_initialize_rq(rq); 1256 } 1257 1258 cmd->device = dev; 1259 INIT_LIST_HEAD(&cmd->eh_entry); 1260 INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler); 1261 } 1262 1263 static blk_status_t scsi_setup_scsi_cmnd(struct scsi_device *sdev, 1264 struct request *req) 1265 { 1266 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); 1267 1268 /* 1269 * Passthrough requests may transfer data, in which case they must 1270 * a bio attached to them. Or they might contain a SCSI command 1271 * that does not transfer data, in which case they may optionally 1272 * submit a request without an attached bio. 1273 */ 1274 if (req->bio) { 1275 blk_status_t ret = scsi_alloc_sgtables(cmd); 1276 if (unlikely(ret != BLK_STS_OK)) 1277 return ret; 1278 } else { 1279 BUG_ON(blk_rq_bytes(req)); 1280 1281 memset(&cmd->sdb, 0, sizeof(cmd->sdb)); 1282 } 1283 1284 cmd->transfersize = blk_rq_bytes(req); 1285 return BLK_STS_OK; 1286 } 1287 1288 static blk_status_t 1289 scsi_device_state_check(struct scsi_device *sdev, struct request *req) 1290 { 1291 switch (sdev->sdev_state) { 1292 case SDEV_CREATED: 1293 return BLK_STS_OK; 1294 case SDEV_OFFLINE: 1295 case SDEV_TRANSPORT_OFFLINE: 1296 /* 1297 * If the device is offline we refuse to process any 1298 * commands. The device must be brought online 1299 * before trying any recovery commands. 1300 */ 1301 if (!sdev->offline_already) { 1302 sdev->offline_already = true; 1303 sdev_printk(KERN_ERR, sdev, 1304 "rejecting I/O to offline device\n"); 1305 } 1306 return BLK_STS_IOERR; 1307 case SDEV_DEL: 1308 /* 1309 * If the device is fully deleted, we refuse to 1310 * process any commands as well. 1311 */ 1312 sdev_printk(KERN_ERR, sdev, 1313 "rejecting I/O to dead device\n"); 1314 return BLK_STS_IOERR; 1315 case SDEV_BLOCK: 1316 case SDEV_CREATED_BLOCK: 1317 return BLK_STS_RESOURCE; 1318 case SDEV_QUIESCE: 1319 /* 1320 * If the device is blocked we only accept power management 1321 * commands. 1322 */ 1323 if (req && WARN_ON_ONCE(!(req->rq_flags & RQF_PM))) 1324 return BLK_STS_RESOURCE; 1325 return BLK_STS_OK; 1326 default: 1327 /* 1328 * For any other not fully online state we only allow 1329 * power management commands. 1330 */ 1331 if (req && !(req->rq_flags & RQF_PM)) 1332 return BLK_STS_OFFLINE; 1333 return BLK_STS_OK; 1334 } 1335 } 1336 1337 /* 1338 * scsi_dev_queue_ready: if we can send requests to sdev, assign one token 1339 * and return the token else return -1. 1340 */ 1341 static inline int scsi_dev_queue_ready(struct request_queue *q, 1342 struct scsi_device *sdev) 1343 { 1344 int token; 1345 1346 token = sbitmap_get(&sdev->budget_map); 1347 if (token < 0) 1348 return -1; 1349 1350 if (!atomic_read(&sdev->device_blocked)) 1351 return token; 1352 1353 /* 1354 * Only unblock if no other commands are pending and 1355 * if device_blocked has decreased to zero 1356 */ 1357 if (scsi_device_busy(sdev) > 1 || 1358 atomic_dec_return(&sdev->device_blocked) > 0) { 1359 sbitmap_put(&sdev->budget_map, token); 1360 return -1; 1361 } 1362 1363 SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev, 1364 "unblocking device at zero depth\n")); 1365 1366 return token; 1367 } 1368 1369 /* 1370 * scsi_target_queue_ready: checks if there we can send commands to target 1371 * @sdev: scsi device on starget to check. 1372 */ 1373 static inline int scsi_target_queue_ready(struct Scsi_Host *shost, 1374 struct scsi_device *sdev) 1375 { 1376 struct scsi_target *starget = scsi_target(sdev); 1377 unsigned int busy; 1378 1379 if (starget->single_lun) { 1380 spin_lock_irq(shost->host_lock); 1381 if (starget->starget_sdev_user && 1382 starget->starget_sdev_user != sdev) { 1383 spin_unlock_irq(shost->host_lock); 1384 return 0; 1385 } 1386 starget->starget_sdev_user = sdev; 1387 spin_unlock_irq(shost->host_lock); 1388 } 1389 1390 if (starget->can_queue <= 0) 1391 return 1; 1392 1393 busy = atomic_inc_return(&starget->target_busy) - 1; 1394 if (atomic_read(&starget->target_blocked) > 0) { 1395 if (busy) 1396 goto starved; 1397 1398 /* 1399 * unblock after target_blocked iterates to zero 1400 */ 1401 if (atomic_dec_return(&starget->target_blocked) > 0) 1402 goto out_dec; 1403 1404 SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget, 1405 "unblocking target at zero depth\n")); 1406 } 1407 1408 if (busy >= starget->can_queue) 1409 goto starved; 1410 1411 return 1; 1412 1413 starved: 1414 spin_lock_irq(shost->host_lock); 1415 list_move_tail(&sdev->starved_entry, &shost->starved_list); 1416 spin_unlock_irq(shost->host_lock); 1417 out_dec: 1418 if (starget->can_queue > 0) 1419 atomic_dec(&starget->target_busy); 1420 return 0; 1421 } 1422 1423 /* 1424 * scsi_host_queue_ready: if we can send requests to shost, return 1 else 1425 * return 0. We must end up running the queue again whenever 0 is 1426 * returned, else IO can hang. 1427 */ 1428 static inline int scsi_host_queue_ready(struct request_queue *q, 1429 struct Scsi_Host *shost, 1430 struct scsi_device *sdev, 1431 struct scsi_cmnd *cmd) 1432 { 1433 if (atomic_read(&shost->host_blocked) > 0) { 1434 if (scsi_host_busy(shost) > 0) 1435 goto starved; 1436 1437 /* 1438 * unblock after host_blocked iterates to zero 1439 */ 1440 if (atomic_dec_return(&shost->host_blocked) > 0) 1441 goto out_dec; 1442 1443 SCSI_LOG_MLQUEUE(3, 1444 shost_printk(KERN_INFO, shost, 1445 "unblocking host at zero depth\n")); 1446 } 1447 1448 if (shost->host_self_blocked) 1449 goto starved; 1450 1451 /* We're OK to process the command, so we can't be starved */ 1452 if (!list_empty(&sdev->starved_entry)) { 1453 spin_lock_irq(shost->host_lock); 1454 if (!list_empty(&sdev->starved_entry)) 1455 list_del_init(&sdev->starved_entry); 1456 spin_unlock_irq(shost->host_lock); 1457 } 1458 1459 __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); 1460 1461 return 1; 1462 1463 starved: 1464 spin_lock_irq(shost->host_lock); 1465 if (list_empty(&sdev->starved_entry)) 1466 list_add_tail(&sdev->starved_entry, &shost->starved_list); 1467 spin_unlock_irq(shost->host_lock); 1468 out_dec: 1469 scsi_dec_host_busy(shost, cmd); 1470 return 0; 1471 } 1472 1473 /* 1474 * Busy state exporting function for request stacking drivers. 1475 * 1476 * For efficiency, no lock is taken to check the busy state of 1477 * shost/starget/sdev, since the returned value is not guaranteed and 1478 * may be changed after request stacking drivers call the function, 1479 * regardless of taking lock or not. 1480 * 1481 * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi 1482 * needs to return 'not busy'. Otherwise, request stacking drivers 1483 * may hold requests forever. 1484 */ 1485 static bool scsi_mq_lld_busy(struct request_queue *q) 1486 { 1487 struct scsi_device *sdev = q->queuedata; 1488 struct Scsi_Host *shost; 1489 1490 if (blk_queue_dying(q)) 1491 return false; 1492 1493 shost = sdev->host; 1494 1495 /* 1496 * Ignore host/starget busy state. 1497 * Since block layer does not have a concept of fairness across 1498 * multiple queues, congestion of host/starget needs to be handled 1499 * in SCSI layer. 1500 */ 1501 if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev)) 1502 return true; 1503 1504 return false; 1505 } 1506 1507 /* 1508 * Block layer request completion callback. May be called from interrupt 1509 * context. 1510 */ 1511 static void scsi_complete(struct request *rq) 1512 { 1513 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); 1514 enum scsi_disposition disposition; 1515 1516 INIT_LIST_HEAD(&cmd->eh_entry); 1517 1518 atomic_inc(&cmd->device->iodone_cnt); 1519 if (cmd->result) 1520 atomic_inc(&cmd->device->ioerr_cnt); 1521 1522 disposition = scsi_decide_disposition(cmd); 1523 if (disposition != SUCCESS && scsi_cmd_runtime_exceeced(cmd)) 1524 disposition = SUCCESS; 1525 1526 scsi_log_completion(cmd, disposition); 1527 1528 switch (disposition) { 1529 case SUCCESS: 1530 scsi_finish_command(cmd); 1531 break; 1532 case NEEDS_RETRY: 1533 scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); 1534 break; 1535 case ADD_TO_MLQUEUE: 1536 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); 1537 break; 1538 default: 1539 scsi_eh_scmd_add(cmd); 1540 break; 1541 } 1542 } 1543 1544 /** 1545 * scsi_dispatch_cmd - Dispatch a command to the low-level driver. 1546 * @cmd: command block we are dispatching. 1547 * 1548 * Return: nonzero return request was rejected and device's queue needs to be 1549 * plugged. 1550 */ 1551 static int scsi_dispatch_cmd(struct scsi_cmnd *cmd) 1552 { 1553 struct Scsi_Host *host = cmd->device->host; 1554 int rtn = 0; 1555 1556 atomic_inc(&cmd->device->iorequest_cnt); 1557 1558 /* check if the device is still usable */ 1559 if (unlikely(cmd->device->sdev_state == SDEV_DEL)) { 1560 /* in SDEV_DEL we error all commands. DID_NO_CONNECT 1561 * returns an immediate error upwards, and signals 1562 * that the device is no longer present */ 1563 cmd->result = DID_NO_CONNECT << 16; 1564 goto done; 1565 } 1566 1567 /* Check to see if the scsi lld made this device blocked. */ 1568 if (unlikely(scsi_device_blocked(cmd->device))) { 1569 /* 1570 * in blocked state, the command is just put back on 1571 * the device queue. The suspend state has already 1572 * blocked the queue so future requests should not 1573 * occur until the device transitions out of the 1574 * suspend state. 1575 */ 1576 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, 1577 "queuecommand : device blocked\n")); 1578 atomic_dec(&cmd->device->iorequest_cnt); 1579 return SCSI_MLQUEUE_DEVICE_BUSY; 1580 } 1581 1582 /* Store the LUN value in cmnd, if needed. */ 1583 if (cmd->device->lun_in_cdb) 1584 cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | 1585 (cmd->device->lun << 5 & 0xe0); 1586 1587 scsi_log_send(cmd); 1588 1589 /* 1590 * Before we queue this command, check if the command 1591 * length exceeds what the host adapter can handle. 1592 */ 1593 if (cmd->cmd_len > cmd->device->host->max_cmd_len) { 1594 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, 1595 "queuecommand : command too long. " 1596 "cdb_size=%d host->max_cmd_len=%d\n", 1597 cmd->cmd_len, cmd->device->host->max_cmd_len)); 1598 cmd->result = (DID_ABORT << 16); 1599 goto done; 1600 } 1601 1602 if (unlikely(host->shost_state == SHOST_DEL)) { 1603 cmd->result = (DID_NO_CONNECT << 16); 1604 goto done; 1605 1606 } 1607 1608 trace_scsi_dispatch_cmd_start(cmd); 1609 rtn = host->hostt->queuecommand(host, cmd); 1610 if (rtn) { 1611 atomic_dec(&cmd->device->iorequest_cnt); 1612 trace_scsi_dispatch_cmd_error(cmd, rtn); 1613 if (rtn != SCSI_MLQUEUE_DEVICE_BUSY && 1614 rtn != SCSI_MLQUEUE_TARGET_BUSY) 1615 rtn = SCSI_MLQUEUE_HOST_BUSY; 1616 1617 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, 1618 "queuecommand : request rejected\n")); 1619 } 1620 1621 return rtn; 1622 done: 1623 scsi_done(cmd); 1624 return 0; 1625 } 1626 1627 /* Size in bytes of the sg-list stored in the scsi-mq command-private data. */ 1628 static unsigned int scsi_mq_inline_sgl_size(struct Scsi_Host *shost) 1629 { 1630 return min_t(unsigned int, shost->sg_tablesize, SCSI_INLINE_SG_CNT) * 1631 sizeof(struct scatterlist); 1632 } 1633 1634 static blk_status_t scsi_prepare_cmd(struct request *req) 1635 { 1636 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); 1637 struct scsi_device *sdev = req->q->queuedata; 1638 struct Scsi_Host *shost = sdev->host; 1639 bool in_flight = test_bit(SCMD_STATE_INFLIGHT, &cmd->state); 1640 struct scatterlist *sg; 1641 1642 scsi_init_command(sdev, cmd); 1643 1644 cmd->eh_eflags = 0; 1645 cmd->prot_type = 0; 1646 cmd->prot_flags = 0; 1647 cmd->submitter = 0; 1648 memset(&cmd->sdb, 0, sizeof(cmd->sdb)); 1649 cmd->underflow = 0; 1650 cmd->transfersize = 0; 1651 cmd->host_scribble = NULL; 1652 cmd->result = 0; 1653 cmd->extra_len = 0; 1654 cmd->state = 0; 1655 if (in_flight) 1656 __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); 1657 1658 /* 1659 * Only clear the driver-private command data if the LLD does not supply 1660 * a function to initialize that data. 1661 */ 1662 if (!shost->hostt->init_cmd_priv) 1663 memset(cmd + 1, 0, shost->hostt->cmd_size); 1664 1665 cmd->prot_op = SCSI_PROT_NORMAL; 1666 if (blk_rq_bytes(req)) 1667 cmd->sc_data_direction = rq_dma_dir(req); 1668 else 1669 cmd->sc_data_direction = DMA_NONE; 1670 1671 sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size; 1672 cmd->sdb.table.sgl = sg; 1673 1674 if (scsi_host_get_prot(shost)) { 1675 memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer)); 1676 1677 cmd->prot_sdb->table.sgl = 1678 (struct scatterlist *)(cmd->prot_sdb + 1); 1679 } 1680 1681 /* 1682 * Special handling for passthrough commands, which don't go to the ULP 1683 * at all: 1684 */ 1685 if (blk_rq_is_passthrough(req)) 1686 return scsi_setup_scsi_cmnd(sdev, req); 1687 1688 if (sdev->handler && sdev->handler->prep_fn) { 1689 blk_status_t ret = sdev->handler->prep_fn(sdev, req); 1690 1691 if (ret != BLK_STS_OK) 1692 return ret; 1693 } 1694 1695 /* Usually overridden by the ULP */ 1696 cmd->allowed = 0; 1697 memset(cmd->cmnd, 0, sizeof(cmd->cmnd)); 1698 return scsi_cmd_to_driver(cmd)->init_command(cmd); 1699 } 1700 1701 static void scsi_done_internal(struct scsi_cmnd *cmd, bool complete_directly) 1702 { 1703 struct request *req = scsi_cmd_to_rq(cmd); 1704 1705 switch (cmd->submitter) { 1706 case SUBMITTED_BY_BLOCK_LAYER: 1707 break; 1708 case SUBMITTED_BY_SCSI_ERROR_HANDLER: 1709 return scsi_eh_done(cmd); 1710 case SUBMITTED_BY_SCSI_RESET_IOCTL: 1711 return; 1712 } 1713 1714 if (unlikely(blk_should_fake_timeout(scsi_cmd_to_rq(cmd)->q))) 1715 return; 1716 if (unlikely(test_and_set_bit(SCMD_STATE_COMPLETE, &cmd->state))) 1717 return; 1718 trace_scsi_dispatch_cmd_done(cmd); 1719 1720 if (complete_directly) 1721 blk_mq_complete_request_direct(req, scsi_complete); 1722 else 1723 blk_mq_complete_request(req); 1724 } 1725 1726 void scsi_done(struct scsi_cmnd *cmd) 1727 { 1728 scsi_done_internal(cmd, false); 1729 } 1730 EXPORT_SYMBOL(scsi_done); 1731 1732 void scsi_done_direct(struct scsi_cmnd *cmd) 1733 { 1734 scsi_done_internal(cmd, true); 1735 } 1736 EXPORT_SYMBOL(scsi_done_direct); 1737 1738 static void scsi_mq_put_budget(struct request_queue *q, int budget_token) 1739 { 1740 struct scsi_device *sdev = q->queuedata; 1741 1742 sbitmap_put(&sdev->budget_map, budget_token); 1743 } 1744 1745 /* 1746 * When to reinvoke queueing after a resource shortage. It's 3 msecs to 1747 * not change behaviour from the previous unplug mechanism, experimentation 1748 * may prove this needs changing. 1749 */ 1750 #define SCSI_QUEUE_DELAY 3 1751 1752 static int scsi_mq_get_budget(struct request_queue *q) 1753 { 1754 struct scsi_device *sdev = q->queuedata; 1755 int token = scsi_dev_queue_ready(q, sdev); 1756 1757 if (token >= 0) 1758 return token; 1759 1760 atomic_inc(&sdev->restarts); 1761 1762 /* 1763 * Orders atomic_inc(&sdev->restarts) and atomic_read(&sdev->device_busy). 1764 * .restarts must be incremented before .device_busy is read because the 1765 * code in scsi_run_queue_async() depends on the order of these operations. 1766 */ 1767 smp_mb__after_atomic(); 1768 1769 /* 1770 * If all in-flight requests originated from this LUN are completed 1771 * before reading .device_busy, sdev->device_busy will be observed as 1772 * zero, then blk_mq_delay_run_hw_queues() will dispatch this request 1773 * soon. Otherwise, completion of one of these requests will observe 1774 * the .restarts flag, and the request queue will be run for handling 1775 * this request, see scsi_end_request(). 1776 */ 1777 if (unlikely(scsi_device_busy(sdev) == 0 && 1778 !scsi_device_blocked(sdev))) 1779 blk_mq_delay_run_hw_queues(sdev->request_queue, SCSI_QUEUE_DELAY); 1780 return -1; 1781 } 1782 1783 static void scsi_mq_set_rq_budget_token(struct request *req, int token) 1784 { 1785 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); 1786 1787 cmd->budget_token = token; 1788 } 1789 1790 static int scsi_mq_get_rq_budget_token(struct request *req) 1791 { 1792 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); 1793 1794 return cmd->budget_token; 1795 } 1796 1797 static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, 1798 const struct blk_mq_queue_data *bd) 1799 { 1800 struct request *req = bd->rq; 1801 struct request_queue *q = req->q; 1802 struct scsi_device *sdev = q->queuedata; 1803 struct Scsi_Host *shost = sdev->host; 1804 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); 1805 blk_status_t ret; 1806 int reason; 1807 1808 WARN_ON_ONCE(cmd->budget_token < 0); 1809 1810 /* 1811 * If the device is not in running state we will reject some or all 1812 * commands. 1813 */ 1814 if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { 1815 ret = scsi_device_state_check(sdev, req); 1816 if (ret != BLK_STS_OK) 1817 goto out_put_budget; 1818 } 1819 1820 ret = BLK_STS_RESOURCE; 1821 if (!scsi_target_queue_ready(shost, sdev)) 1822 goto out_put_budget; 1823 if (unlikely(scsi_host_in_recovery(shost))) { 1824 if (cmd->flags & SCMD_FAIL_IF_RECOVERING) 1825 ret = BLK_STS_OFFLINE; 1826 goto out_dec_target_busy; 1827 } 1828 if (!scsi_host_queue_ready(q, shost, sdev, cmd)) 1829 goto out_dec_target_busy; 1830 1831 if (!(req->rq_flags & RQF_DONTPREP)) { 1832 ret = scsi_prepare_cmd(req); 1833 if (ret != BLK_STS_OK) 1834 goto out_dec_host_busy; 1835 req->rq_flags |= RQF_DONTPREP; 1836 } else { 1837 clear_bit(SCMD_STATE_COMPLETE, &cmd->state); 1838 } 1839 1840 cmd->flags &= SCMD_PRESERVED_FLAGS; 1841 if (sdev->simple_tags) 1842 cmd->flags |= SCMD_TAGGED; 1843 if (bd->last) 1844 cmd->flags |= SCMD_LAST; 1845 1846 scsi_set_resid(cmd, 0); 1847 memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); 1848 cmd->submitter = SUBMITTED_BY_BLOCK_LAYER; 1849 1850 blk_mq_start_request(req); 1851 reason = scsi_dispatch_cmd(cmd); 1852 if (reason) { 1853 scsi_set_blocked(cmd, reason); 1854 ret = BLK_STS_RESOURCE; 1855 goto out_dec_host_busy; 1856 } 1857 1858 return BLK_STS_OK; 1859 1860 out_dec_host_busy: 1861 scsi_dec_host_busy(shost, cmd); 1862 out_dec_target_busy: 1863 if (scsi_target(sdev)->can_queue > 0) 1864 atomic_dec(&scsi_target(sdev)->target_busy); 1865 out_put_budget: 1866 scsi_mq_put_budget(q, cmd->budget_token); 1867 cmd->budget_token = -1; 1868 switch (ret) { 1869 case BLK_STS_OK: 1870 break; 1871 case BLK_STS_RESOURCE: 1872 case BLK_STS_ZONE_RESOURCE: 1873 if (scsi_device_blocked(sdev)) 1874 ret = BLK_STS_DEV_RESOURCE; 1875 break; 1876 case BLK_STS_AGAIN: 1877 cmd->result = DID_BUS_BUSY << 16; 1878 if (req->rq_flags & RQF_DONTPREP) 1879 scsi_mq_uninit_cmd(cmd); 1880 break; 1881 default: 1882 if (unlikely(!scsi_device_online(sdev))) 1883 cmd->result = DID_NO_CONNECT << 16; 1884 else 1885 cmd->result = DID_ERROR << 16; 1886 /* 1887 * Make sure to release all allocated resources when 1888 * we hit an error, as we will never see this command 1889 * again. 1890 */ 1891 if (req->rq_flags & RQF_DONTPREP) 1892 scsi_mq_uninit_cmd(cmd); 1893 scsi_run_queue_async(sdev); 1894 break; 1895 } 1896 return ret; 1897 } 1898 1899 static int scsi_mq_init_request(struct blk_mq_tag_set *set, struct request *rq, 1900 unsigned int hctx_idx, unsigned int numa_node) 1901 { 1902 struct Scsi_Host *shost = set->driver_data; 1903 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); 1904 struct scatterlist *sg; 1905 int ret = 0; 1906 1907 cmd->sense_buffer = 1908 kmem_cache_alloc_node(scsi_sense_cache, GFP_KERNEL, numa_node); 1909 if (!cmd->sense_buffer) 1910 return -ENOMEM; 1911 1912 if (scsi_host_get_prot(shost)) { 1913 sg = (void *)cmd + sizeof(struct scsi_cmnd) + 1914 shost->hostt->cmd_size; 1915 cmd->prot_sdb = (void *)sg + scsi_mq_inline_sgl_size(shost); 1916 } 1917 1918 if (shost->hostt->init_cmd_priv) { 1919 ret = shost->hostt->init_cmd_priv(shost, cmd); 1920 if (ret < 0) 1921 kmem_cache_free(scsi_sense_cache, cmd->sense_buffer); 1922 } 1923 1924 return ret; 1925 } 1926 1927 static void scsi_mq_exit_request(struct blk_mq_tag_set *set, struct request *rq, 1928 unsigned int hctx_idx) 1929 { 1930 struct Scsi_Host *shost = set->driver_data; 1931 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); 1932 1933 if (shost->hostt->exit_cmd_priv) 1934 shost->hostt->exit_cmd_priv(shost, cmd); 1935 kmem_cache_free(scsi_sense_cache, cmd->sense_buffer); 1936 } 1937 1938 1939 static int scsi_mq_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) 1940 { 1941 struct Scsi_Host *shost = hctx->driver_data; 1942 1943 if (shost->hostt->mq_poll) 1944 return shost->hostt->mq_poll(shost, hctx->queue_num); 1945 1946 return 0; 1947 } 1948 1949 static int scsi_init_hctx(struct blk_mq_hw_ctx *hctx, void *data, 1950 unsigned int hctx_idx) 1951 { 1952 struct Scsi_Host *shost = data; 1953 1954 hctx->driver_data = shost; 1955 return 0; 1956 } 1957 1958 static void scsi_map_queues(struct blk_mq_tag_set *set) 1959 { 1960 struct Scsi_Host *shost = container_of(set, struct Scsi_Host, tag_set); 1961 1962 if (shost->hostt->map_queues) 1963 return shost->hostt->map_queues(shost); 1964 blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]); 1965 } 1966 1967 void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) 1968 { 1969 struct device *dev = shost->dma_dev; 1970 1971 /* 1972 * this limit is imposed by hardware restrictions 1973 */ 1974 blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize, 1975 SG_MAX_SEGMENTS)); 1976 1977 if (scsi_host_prot_dma(shost)) { 1978 shost->sg_prot_tablesize = 1979 min_not_zero(shost->sg_prot_tablesize, 1980 (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS); 1981 BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize); 1982 blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize); 1983 } 1984 1985 blk_queue_max_hw_sectors(q, shost->max_sectors); 1986 blk_queue_segment_boundary(q, shost->dma_boundary); 1987 dma_set_seg_boundary(dev, shost->dma_boundary); 1988 1989 blk_queue_max_segment_size(q, shost->max_segment_size); 1990 blk_queue_virt_boundary(q, shost->virt_boundary_mask); 1991 dma_set_max_seg_size(dev, queue_max_segment_size(q)); 1992 1993 /* 1994 * Set a reasonable default alignment: The larger of 32-byte (dword), 1995 * which is a common minimum for HBAs, and the minimum DMA alignment, 1996 * which is set by the platform. 1997 * 1998 * Devices that require a bigger alignment can increase it later. 1999 */ 2000 blk_queue_dma_alignment(q, max(4, dma_get_cache_alignment()) - 1); 2001 } 2002 EXPORT_SYMBOL_GPL(__scsi_init_queue); 2003 2004 static const struct blk_mq_ops scsi_mq_ops_no_commit = { 2005 .get_budget = scsi_mq_get_budget, 2006 .put_budget = scsi_mq_put_budget, 2007 .queue_rq = scsi_queue_rq, 2008 .complete = scsi_complete, 2009 .timeout = scsi_timeout, 2010 #ifdef CONFIG_BLK_DEBUG_FS 2011 .show_rq = scsi_show_rq, 2012 #endif 2013 .init_request = scsi_mq_init_request, 2014 .exit_request = scsi_mq_exit_request, 2015 .cleanup_rq = scsi_cleanup_rq, 2016 .busy = scsi_mq_lld_busy, 2017 .map_queues = scsi_map_queues, 2018 .init_hctx = scsi_init_hctx, 2019 .poll = scsi_mq_poll, 2020 .set_rq_budget_token = scsi_mq_set_rq_budget_token, 2021 .get_rq_budget_token = scsi_mq_get_rq_budget_token, 2022 }; 2023 2024 2025 static void scsi_commit_rqs(struct blk_mq_hw_ctx *hctx) 2026 { 2027 struct Scsi_Host *shost = hctx->driver_data; 2028 2029 shost->hostt->commit_rqs(shost, hctx->queue_num); 2030 } 2031 2032 static const struct blk_mq_ops scsi_mq_ops = { 2033 .get_budget = scsi_mq_get_budget, 2034 .put_budget = scsi_mq_put_budget, 2035 .queue_rq = scsi_queue_rq, 2036 .commit_rqs = scsi_commit_rqs, 2037 .complete = scsi_complete, 2038 .timeout = scsi_timeout, 2039 #ifdef CONFIG_BLK_DEBUG_FS 2040 .show_rq = scsi_show_rq, 2041 #endif 2042 .init_request = scsi_mq_init_request, 2043 .exit_request = scsi_mq_exit_request, 2044 .cleanup_rq = scsi_cleanup_rq, 2045 .busy = scsi_mq_lld_busy, 2046 .map_queues = scsi_map_queues, 2047 .init_hctx = scsi_init_hctx, 2048 .poll = scsi_mq_poll, 2049 .set_rq_budget_token = scsi_mq_set_rq_budget_token, 2050 .get_rq_budget_token = scsi_mq_get_rq_budget_token, 2051 }; 2052 2053 int scsi_mq_setup_tags(struct Scsi_Host *shost) 2054 { 2055 unsigned int cmd_size, sgl_size; 2056 struct blk_mq_tag_set *tag_set = &shost->tag_set; 2057 2058 sgl_size = max_t(unsigned int, sizeof(struct scatterlist), 2059 scsi_mq_inline_sgl_size(shost)); 2060 cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size + sgl_size; 2061 if (scsi_host_get_prot(shost)) 2062 cmd_size += sizeof(struct scsi_data_buffer) + 2063 sizeof(struct scatterlist) * SCSI_INLINE_PROT_SG_CNT; 2064 2065 memset(tag_set, 0, sizeof(*tag_set)); 2066 if (shost->hostt->commit_rqs) 2067 tag_set->ops = &scsi_mq_ops; 2068 else 2069 tag_set->ops = &scsi_mq_ops_no_commit; 2070 tag_set->nr_hw_queues = shost->nr_hw_queues ? : 1; 2071 tag_set->nr_maps = shost->nr_maps ? : 1; 2072 tag_set->queue_depth = shost->can_queue; 2073 tag_set->cmd_size = cmd_size; 2074 tag_set->numa_node = dev_to_node(shost->dma_dev); 2075 tag_set->flags = BLK_MQ_F_SHOULD_MERGE; 2076 tag_set->flags |= 2077 BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy); 2078 if (shost->queuecommand_may_block) 2079 tag_set->flags |= BLK_MQ_F_BLOCKING; 2080 tag_set->driver_data = shost; 2081 if (shost->host_tagset) 2082 tag_set->flags |= BLK_MQ_F_TAG_HCTX_SHARED; 2083 2084 return blk_mq_alloc_tag_set(tag_set); 2085 } 2086 2087 void scsi_mq_free_tags(struct kref *kref) 2088 { 2089 struct Scsi_Host *shost = container_of(kref, typeof(*shost), 2090 tagset_refcnt); 2091 2092 blk_mq_free_tag_set(&shost->tag_set); 2093 complete(&shost->tagset_freed); 2094 } 2095 2096 /** 2097 * scsi_device_from_queue - return sdev associated with a request_queue 2098 * @q: The request queue to return the sdev from 2099 * 2100 * Return the sdev associated with a request queue or NULL if the 2101 * request_queue does not reference a SCSI device. 2102 */ 2103 struct scsi_device *scsi_device_from_queue(struct request_queue *q) 2104 { 2105 struct scsi_device *sdev = NULL; 2106 2107 if (q->mq_ops == &scsi_mq_ops_no_commit || 2108 q->mq_ops == &scsi_mq_ops) 2109 sdev = q->queuedata; 2110 if (!sdev || !get_device(&sdev->sdev_gendev)) 2111 sdev = NULL; 2112 2113 return sdev; 2114 } 2115 /* 2116 * pktcdvd should have been integrated into the SCSI layers, but for historical 2117 * reasons like the old IDE driver it isn't. This export allows it to safely 2118 * probe if a given device is a SCSI one and only attach to that. 2119 */ 2120 #ifdef CONFIG_CDROM_PKTCDVD_MODULE 2121 EXPORT_SYMBOL_GPL(scsi_device_from_queue); 2122 #endif 2123 2124 /** 2125 * scsi_block_requests - Utility function used by low-level drivers to prevent 2126 * further commands from being queued to the device. 2127 * @shost: host in question 2128 * 2129 * There is no timer nor any other means by which the requests get unblocked 2130 * other than the low-level driver calling scsi_unblock_requests(). 2131 */ 2132 void scsi_block_requests(struct Scsi_Host *shost) 2133 { 2134 shost->host_self_blocked = 1; 2135 } 2136 EXPORT_SYMBOL(scsi_block_requests); 2137 2138 /** 2139 * scsi_unblock_requests - Utility function used by low-level drivers to allow 2140 * further commands to be queued to the device. 2141 * @shost: host in question 2142 * 2143 * There is no timer nor any other means by which the requests get unblocked 2144 * other than the low-level driver calling scsi_unblock_requests(). This is done 2145 * as an API function so that changes to the internals of the scsi mid-layer 2146 * won't require wholesale changes to drivers that use this feature. 2147 */ 2148 void scsi_unblock_requests(struct Scsi_Host *shost) 2149 { 2150 shost->host_self_blocked = 0; 2151 scsi_run_host_queues(shost); 2152 } 2153 EXPORT_SYMBOL(scsi_unblock_requests); 2154 2155 void scsi_exit_queue(void) 2156 { 2157 kmem_cache_destroy(scsi_sense_cache); 2158 } 2159 2160 /** 2161 * scsi_mode_select - issue a mode select 2162 * @sdev: SCSI device to be queried 2163 * @pf: Page format bit (1 == standard, 0 == vendor specific) 2164 * @sp: Save page bit (0 == don't save, 1 == save) 2165 * @buffer: request buffer (may not be smaller than eight bytes) 2166 * @len: length of request buffer. 2167 * @timeout: command timeout 2168 * @retries: number of retries before failing 2169 * @data: returns a structure abstracting the mode header data 2170 * @sshdr: place to put sense data (or NULL if no sense to be collected). 2171 * must be SCSI_SENSE_BUFFERSIZE big. 2172 * 2173 * Returns zero if successful; negative error number or scsi 2174 * status on error 2175 * 2176 */ 2177 int scsi_mode_select(struct scsi_device *sdev, int pf, int sp, 2178 unsigned char *buffer, int len, int timeout, int retries, 2179 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) 2180 { 2181 unsigned char cmd[10]; 2182 unsigned char *real_buffer; 2183 const struct scsi_exec_args exec_args = { 2184 .sshdr = sshdr, 2185 }; 2186 int ret; 2187 2188 memset(cmd, 0, sizeof(cmd)); 2189 cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); 2190 2191 /* 2192 * Use MODE SELECT(10) if the device asked for it or if the mode page 2193 * and the mode select header cannot fit within the maximumm 255 bytes 2194 * of the MODE SELECT(6) command. 2195 */ 2196 if (sdev->use_10_for_ms || 2197 len + 4 > 255 || 2198 data->block_descriptor_length > 255) { 2199 if (len > 65535 - 8) 2200 return -EINVAL; 2201 real_buffer = kmalloc(8 + len, GFP_KERNEL); 2202 if (!real_buffer) 2203 return -ENOMEM; 2204 memcpy(real_buffer + 8, buffer, len); 2205 len += 8; 2206 real_buffer[0] = 0; 2207 real_buffer[1] = 0; 2208 real_buffer[2] = data->medium_type; 2209 real_buffer[3] = data->device_specific; 2210 real_buffer[4] = data->longlba ? 0x01 : 0; 2211 real_buffer[5] = 0; 2212 put_unaligned_be16(data->block_descriptor_length, 2213 &real_buffer[6]); 2214 2215 cmd[0] = MODE_SELECT_10; 2216 put_unaligned_be16(len, &cmd[7]); 2217 } else { 2218 if (data->longlba) 2219 return -EINVAL; 2220 2221 real_buffer = kmalloc(4 + len, GFP_KERNEL); 2222 if (!real_buffer) 2223 return -ENOMEM; 2224 memcpy(real_buffer + 4, buffer, len); 2225 len += 4; 2226 real_buffer[0] = 0; 2227 real_buffer[1] = data->medium_type; 2228 real_buffer[2] = data->device_specific; 2229 real_buffer[3] = data->block_descriptor_length; 2230 2231 cmd[0] = MODE_SELECT; 2232 cmd[4] = len; 2233 } 2234 2235 ret = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_OUT, real_buffer, len, 2236 timeout, retries, &exec_args); 2237 kfree(real_buffer); 2238 return ret; 2239 } 2240 EXPORT_SYMBOL_GPL(scsi_mode_select); 2241 2242 /** 2243 * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary. 2244 * @sdev: SCSI device to be queried 2245 * @dbd: set to prevent mode sense from returning block descriptors 2246 * @modepage: mode page being requested 2247 * @subpage: sub-page of the mode page being requested 2248 * @buffer: request buffer (may not be smaller than eight bytes) 2249 * @len: length of request buffer. 2250 * @timeout: command timeout 2251 * @retries: number of retries before failing 2252 * @data: returns a structure abstracting the mode header data 2253 * @sshdr: place to put sense data (or NULL if no sense to be collected). 2254 * must be SCSI_SENSE_BUFFERSIZE big. 2255 * 2256 * Returns zero if successful, or a negative error number on failure 2257 */ 2258 int 2259 scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, int subpage, 2260 unsigned char *buffer, int len, int timeout, int retries, 2261 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) 2262 { 2263 unsigned char cmd[12]; 2264 int use_10_for_ms; 2265 int header_length; 2266 int result; 2267 struct scsi_sense_hdr my_sshdr; 2268 struct scsi_failure failure_defs[] = { 2269 { 2270 .sense = UNIT_ATTENTION, 2271 .asc = SCMD_FAILURE_ASC_ANY, 2272 .ascq = SCMD_FAILURE_ASCQ_ANY, 2273 .allowed = retries, 2274 .result = SAM_STAT_CHECK_CONDITION, 2275 }, 2276 {} 2277 }; 2278 struct scsi_failures failures = { 2279 .failure_definitions = failure_defs, 2280 }; 2281 const struct scsi_exec_args exec_args = { 2282 /* caller might not be interested in sense, but we need it */ 2283 .sshdr = sshdr ? : &my_sshdr, 2284 .failures = &failures, 2285 }; 2286 2287 memset(data, 0, sizeof(*data)); 2288 memset(&cmd[0], 0, 12); 2289 2290 dbd = sdev->set_dbd_for_ms ? 8 : dbd; 2291 cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ 2292 cmd[2] = modepage; 2293 cmd[3] = subpage; 2294 2295 sshdr = exec_args.sshdr; 2296 2297 retry: 2298 use_10_for_ms = sdev->use_10_for_ms || len > 255; 2299 2300 if (use_10_for_ms) { 2301 if (len < 8 || len > 65535) 2302 return -EINVAL; 2303 2304 cmd[0] = MODE_SENSE_10; 2305 put_unaligned_be16(len, &cmd[7]); 2306 header_length = 8; 2307 } else { 2308 if (len < 4) 2309 return -EINVAL; 2310 2311 cmd[0] = MODE_SENSE; 2312 cmd[4] = len; 2313 header_length = 4; 2314 } 2315 2316 memset(buffer, 0, len); 2317 2318 result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, buffer, len, 2319 timeout, retries, &exec_args); 2320 if (result < 0) 2321 return result; 2322 2323 /* This code looks awful: what it's doing is making sure an 2324 * ILLEGAL REQUEST sense return identifies the actual command 2325 * byte as the problem. MODE_SENSE commands can return 2326 * ILLEGAL REQUEST if the code page isn't supported */ 2327 2328 if (!scsi_status_is_good(result)) { 2329 if (scsi_sense_valid(sshdr)) { 2330 if ((sshdr->sense_key == ILLEGAL_REQUEST) && 2331 (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { 2332 /* 2333 * Invalid command operation code: retry using 2334 * MODE SENSE(6) if this was a MODE SENSE(10) 2335 * request, except if the request mode page is 2336 * too large for MODE SENSE single byte 2337 * allocation length field. 2338 */ 2339 if (use_10_for_ms) { 2340 if (len > 255) 2341 return -EIO; 2342 sdev->use_10_for_ms = 0; 2343 goto retry; 2344 } 2345 } 2346 } 2347 return -EIO; 2348 } 2349 if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && 2350 (modepage == 6 || modepage == 8))) { 2351 /* Initio breakage? */ 2352 header_length = 0; 2353 data->length = 13; 2354 data->medium_type = 0; 2355 data->device_specific = 0; 2356 data->longlba = 0; 2357 data->block_descriptor_length = 0; 2358 } else if (use_10_for_ms) { 2359 data->length = get_unaligned_be16(&buffer[0]) + 2; 2360 data->medium_type = buffer[2]; 2361 data->device_specific = buffer[3]; 2362 data->longlba = buffer[4] & 0x01; 2363 data->block_descriptor_length = get_unaligned_be16(&buffer[6]); 2364 } else { 2365 data->length = buffer[0] + 1; 2366 data->medium_type = buffer[1]; 2367 data->device_specific = buffer[2]; 2368 data->block_descriptor_length = buffer[3]; 2369 } 2370 data->header_length = header_length; 2371 2372 return 0; 2373 } 2374 EXPORT_SYMBOL(scsi_mode_sense); 2375 2376 /** 2377 * scsi_test_unit_ready - test if unit is ready 2378 * @sdev: scsi device to change the state of. 2379 * @timeout: command timeout 2380 * @retries: number of retries before failing 2381 * @sshdr: outpout pointer for decoded sense information. 2382 * 2383 * Returns zero if unsuccessful or an error if TUR failed. For 2384 * removable media, UNIT_ATTENTION sets ->changed flag. 2385 **/ 2386 int 2387 scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, 2388 struct scsi_sense_hdr *sshdr) 2389 { 2390 char cmd[] = { 2391 TEST_UNIT_READY, 0, 0, 0, 0, 0, 2392 }; 2393 const struct scsi_exec_args exec_args = { 2394 .sshdr = sshdr, 2395 }; 2396 int result; 2397 2398 /* try to eat the UNIT_ATTENTION if there are enough retries */ 2399 do { 2400 result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, NULL, 0, 2401 timeout, 1, &exec_args); 2402 if (sdev->removable && result > 0 && scsi_sense_valid(sshdr) && 2403 sshdr->sense_key == UNIT_ATTENTION) 2404 sdev->changed = 1; 2405 } while (result > 0 && scsi_sense_valid(sshdr) && 2406 sshdr->sense_key == UNIT_ATTENTION && --retries); 2407 2408 return result; 2409 } 2410 EXPORT_SYMBOL(scsi_test_unit_ready); 2411 2412 /** 2413 * scsi_device_set_state - Take the given device through the device state model. 2414 * @sdev: scsi device to change the state of. 2415 * @state: state to change to. 2416 * 2417 * Returns zero if successful or an error if the requested 2418 * transition is illegal. 2419 */ 2420 int 2421 scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) 2422 { 2423 enum scsi_device_state oldstate = sdev->sdev_state; 2424 2425 if (state == oldstate) 2426 return 0; 2427 2428 switch (state) { 2429 case SDEV_CREATED: 2430 switch (oldstate) { 2431 case SDEV_CREATED_BLOCK: 2432 break; 2433 default: 2434 goto illegal; 2435 } 2436 break; 2437 2438 case SDEV_RUNNING: 2439 switch (oldstate) { 2440 case SDEV_CREATED: 2441 case SDEV_OFFLINE: 2442 case SDEV_TRANSPORT_OFFLINE: 2443 case SDEV_QUIESCE: 2444 case SDEV_BLOCK: 2445 break; 2446 default: 2447 goto illegal; 2448 } 2449 break; 2450 2451 case SDEV_QUIESCE: 2452 switch (oldstate) { 2453 case SDEV_RUNNING: 2454 case SDEV_OFFLINE: 2455 case SDEV_TRANSPORT_OFFLINE: 2456 break; 2457 default: 2458 goto illegal; 2459 } 2460 break; 2461 2462 case SDEV_OFFLINE: 2463 case SDEV_TRANSPORT_OFFLINE: 2464 switch (oldstate) { 2465 case SDEV_CREATED: 2466 case SDEV_RUNNING: 2467 case SDEV_QUIESCE: 2468 case SDEV_BLOCK: 2469 break; 2470 default: 2471 goto illegal; 2472 } 2473 break; 2474 2475 case SDEV_BLOCK: 2476 switch (oldstate) { 2477 case SDEV_RUNNING: 2478 case SDEV_CREATED_BLOCK: 2479 case SDEV_QUIESCE: 2480 case SDEV_OFFLINE: 2481 break; 2482 default: 2483 goto illegal; 2484 } 2485 break; 2486 2487 case SDEV_CREATED_BLOCK: 2488 switch (oldstate) { 2489 case SDEV_CREATED: 2490 break; 2491 default: 2492 goto illegal; 2493 } 2494 break; 2495 2496 case SDEV_CANCEL: 2497 switch (oldstate) { 2498 case SDEV_CREATED: 2499 case SDEV_RUNNING: 2500 case SDEV_QUIESCE: 2501 case SDEV_OFFLINE: 2502 case SDEV_TRANSPORT_OFFLINE: 2503 break; 2504 default: 2505 goto illegal; 2506 } 2507 break; 2508 2509 case SDEV_DEL: 2510 switch (oldstate) { 2511 case SDEV_CREATED: 2512 case SDEV_RUNNING: 2513 case SDEV_OFFLINE: 2514 case SDEV_TRANSPORT_OFFLINE: 2515 case SDEV_CANCEL: 2516 case SDEV_BLOCK: 2517 case SDEV_CREATED_BLOCK: 2518 break; 2519 default: 2520 goto illegal; 2521 } 2522 break; 2523 2524 } 2525 sdev->offline_already = false; 2526 sdev->sdev_state = state; 2527 return 0; 2528 2529 illegal: 2530 SCSI_LOG_ERROR_RECOVERY(1, 2531 sdev_printk(KERN_ERR, sdev, 2532 "Illegal state transition %s->%s", 2533 scsi_device_state_name(oldstate), 2534 scsi_device_state_name(state)) 2535 ); 2536 return -EINVAL; 2537 } 2538 EXPORT_SYMBOL(scsi_device_set_state); 2539 2540 /** 2541 * scsi_evt_emit - emit a single SCSI device uevent 2542 * @sdev: associated SCSI device 2543 * @evt: event to emit 2544 * 2545 * Send a single uevent (scsi_event) to the associated scsi_device. 2546 */ 2547 static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) 2548 { 2549 int idx = 0; 2550 char *envp[3]; 2551 2552 switch (evt->evt_type) { 2553 case SDEV_EVT_MEDIA_CHANGE: 2554 envp[idx++] = "SDEV_MEDIA_CHANGE=1"; 2555 break; 2556 case SDEV_EVT_INQUIRY_CHANGE_REPORTED: 2557 scsi_rescan_device(sdev); 2558 envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED"; 2559 break; 2560 case SDEV_EVT_CAPACITY_CHANGE_REPORTED: 2561 envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED"; 2562 break; 2563 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: 2564 envp[idx++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED"; 2565 break; 2566 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: 2567 envp[idx++] = "SDEV_UA=MODE_PARAMETERS_CHANGED"; 2568 break; 2569 case SDEV_EVT_LUN_CHANGE_REPORTED: 2570 envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED"; 2571 break; 2572 case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED: 2573 envp[idx++] = "SDEV_UA=ASYMMETRIC_ACCESS_STATE_CHANGED"; 2574 break; 2575 case SDEV_EVT_POWER_ON_RESET_OCCURRED: 2576 envp[idx++] = "SDEV_UA=POWER_ON_RESET_OCCURRED"; 2577 break; 2578 default: 2579 /* do nothing */ 2580 break; 2581 } 2582 2583 envp[idx++] = NULL; 2584 2585 kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); 2586 } 2587 2588 /** 2589 * scsi_evt_thread - send a uevent for each scsi event 2590 * @work: work struct for scsi_device 2591 * 2592 * Dispatch queued events to their associated scsi_device kobjects 2593 * as uevents. 2594 */ 2595 void scsi_evt_thread(struct work_struct *work) 2596 { 2597 struct scsi_device *sdev; 2598 enum scsi_device_event evt_type; 2599 LIST_HEAD(event_list); 2600 2601 sdev = container_of(work, struct scsi_device, event_work); 2602 2603 for (evt_type = SDEV_EVT_FIRST; evt_type <= SDEV_EVT_LAST; evt_type++) 2604 if (test_and_clear_bit(evt_type, sdev->pending_events)) 2605 sdev_evt_send_simple(sdev, evt_type, GFP_KERNEL); 2606 2607 while (1) { 2608 struct scsi_event *evt; 2609 struct list_head *this, *tmp; 2610 unsigned long flags; 2611 2612 spin_lock_irqsave(&sdev->list_lock, flags); 2613 list_splice_init(&sdev->event_list, &event_list); 2614 spin_unlock_irqrestore(&sdev->list_lock, flags); 2615 2616 if (list_empty(&event_list)) 2617 break; 2618 2619 list_for_each_safe(this, tmp, &event_list) { 2620 evt = list_entry(this, struct scsi_event, node); 2621 list_del(&evt->node); 2622 scsi_evt_emit(sdev, evt); 2623 kfree(evt); 2624 } 2625 } 2626 } 2627 2628 /** 2629 * sdev_evt_send - send asserted event to uevent thread 2630 * @sdev: scsi_device event occurred on 2631 * @evt: event to send 2632 * 2633 * Assert scsi device event asynchronously. 2634 */ 2635 void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) 2636 { 2637 unsigned long flags; 2638 2639 #if 0 2640 /* FIXME: currently this check eliminates all media change events 2641 * for polled devices. Need to update to discriminate between AN 2642 * and polled events */ 2643 if (!test_bit(evt->evt_type, sdev->supported_events)) { 2644 kfree(evt); 2645 return; 2646 } 2647 #endif 2648 2649 spin_lock_irqsave(&sdev->list_lock, flags); 2650 list_add_tail(&evt->node, &sdev->event_list); 2651 schedule_work(&sdev->event_work); 2652 spin_unlock_irqrestore(&sdev->list_lock, flags); 2653 } 2654 EXPORT_SYMBOL_GPL(sdev_evt_send); 2655 2656 /** 2657 * sdev_evt_alloc - allocate a new scsi event 2658 * @evt_type: type of event to allocate 2659 * @gfpflags: GFP flags for allocation 2660 * 2661 * Allocates and returns a new scsi_event. 2662 */ 2663 struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, 2664 gfp_t gfpflags) 2665 { 2666 struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); 2667 if (!evt) 2668 return NULL; 2669 2670 evt->evt_type = evt_type; 2671 INIT_LIST_HEAD(&evt->node); 2672 2673 /* evt_type-specific initialization, if any */ 2674 switch (evt_type) { 2675 case SDEV_EVT_MEDIA_CHANGE: 2676 case SDEV_EVT_INQUIRY_CHANGE_REPORTED: 2677 case SDEV_EVT_CAPACITY_CHANGE_REPORTED: 2678 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: 2679 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: 2680 case SDEV_EVT_LUN_CHANGE_REPORTED: 2681 case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED: 2682 case SDEV_EVT_POWER_ON_RESET_OCCURRED: 2683 default: 2684 /* do nothing */ 2685 break; 2686 } 2687 2688 return evt; 2689 } 2690 EXPORT_SYMBOL_GPL(sdev_evt_alloc); 2691 2692 /** 2693 * sdev_evt_send_simple - send asserted event to uevent thread 2694 * @sdev: scsi_device event occurred on 2695 * @evt_type: type of event to send 2696 * @gfpflags: GFP flags for allocation 2697 * 2698 * Assert scsi device event asynchronously, given an event type. 2699 */ 2700 void sdev_evt_send_simple(struct scsi_device *sdev, 2701 enum scsi_device_event evt_type, gfp_t gfpflags) 2702 { 2703 struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); 2704 if (!evt) { 2705 sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", 2706 evt_type); 2707 return; 2708 } 2709 2710 sdev_evt_send(sdev, evt); 2711 } 2712 EXPORT_SYMBOL_GPL(sdev_evt_send_simple); 2713 2714 /** 2715 * scsi_device_quiesce - Block all commands except power management. 2716 * @sdev: scsi device to quiesce. 2717 * 2718 * This works by trying to transition to the SDEV_QUIESCE state 2719 * (which must be a legal transition). When the device is in this 2720 * state, only power management requests will be accepted, all others will 2721 * be deferred. 2722 * 2723 * Must be called with user context, may sleep. 2724 * 2725 * Returns zero if unsuccessful or an error if not. 2726 */ 2727 int 2728 scsi_device_quiesce(struct scsi_device *sdev) 2729 { 2730 struct request_queue *q = sdev->request_queue; 2731 int err; 2732 2733 /* 2734 * It is allowed to call scsi_device_quiesce() multiple times from 2735 * the same context but concurrent scsi_device_quiesce() calls are 2736 * not allowed. 2737 */ 2738 WARN_ON_ONCE(sdev->quiesced_by && sdev->quiesced_by != current); 2739 2740 if (sdev->quiesced_by == current) 2741 return 0; 2742 2743 blk_set_pm_only(q); 2744 2745 blk_mq_freeze_queue(q); 2746 /* 2747 * Ensure that the effect of blk_set_pm_only() will be visible 2748 * for percpu_ref_tryget() callers that occur after the queue 2749 * unfreeze even if the queue was already frozen before this function 2750 * was called. See also https://lwn.net/Articles/573497/. 2751 */ 2752 synchronize_rcu(); 2753 blk_mq_unfreeze_queue(q); 2754 2755 mutex_lock(&sdev->state_mutex); 2756 err = scsi_device_set_state(sdev, SDEV_QUIESCE); 2757 if (err == 0) 2758 sdev->quiesced_by = current; 2759 else 2760 blk_clear_pm_only(q); 2761 mutex_unlock(&sdev->state_mutex); 2762 2763 return err; 2764 } 2765 EXPORT_SYMBOL(scsi_device_quiesce); 2766 2767 /** 2768 * scsi_device_resume - Restart user issued commands to a quiesced device. 2769 * @sdev: scsi device to resume. 2770 * 2771 * Moves the device from quiesced back to running and restarts the 2772 * queues. 2773 * 2774 * Must be called with user context, may sleep. 2775 */ 2776 void scsi_device_resume(struct scsi_device *sdev) 2777 { 2778 /* check if the device state was mutated prior to resume, and if 2779 * so assume the state is being managed elsewhere (for example 2780 * device deleted during suspend) 2781 */ 2782 mutex_lock(&sdev->state_mutex); 2783 if (sdev->sdev_state == SDEV_QUIESCE) 2784 scsi_device_set_state(sdev, SDEV_RUNNING); 2785 if (sdev->quiesced_by) { 2786 sdev->quiesced_by = NULL; 2787 blk_clear_pm_only(sdev->request_queue); 2788 } 2789 mutex_unlock(&sdev->state_mutex); 2790 } 2791 EXPORT_SYMBOL(scsi_device_resume); 2792 2793 static void 2794 device_quiesce_fn(struct scsi_device *sdev, void *data) 2795 { 2796 scsi_device_quiesce(sdev); 2797 } 2798 2799 void 2800 scsi_target_quiesce(struct scsi_target *starget) 2801 { 2802 starget_for_each_device(starget, NULL, device_quiesce_fn); 2803 } 2804 EXPORT_SYMBOL(scsi_target_quiesce); 2805 2806 static void 2807 device_resume_fn(struct scsi_device *sdev, void *data) 2808 { 2809 scsi_device_resume(sdev); 2810 } 2811 2812 void 2813 scsi_target_resume(struct scsi_target *starget) 2814 { 2815 starget_for_each_device(starget, NULL, device_resume_fn); 2816 } 2817 EXPORT_SYMBOL(scsi_target_resume); 2818 2819 static int __scsi_internal_device_block_nowait(struct scsi_device *sdev) 2820 { 2821 if (scsi_device_set_state(sdev, SDEV_BLOCK)) 2822 return scsi_device_set_state(sdev, SDEV_CREATED_BLOCK); 2823 2824 return 0; 2825 } 2826 2827 void scsi_start_queue(struct scsi_device *sdev) 2828 { 2829 if (cmpxchg(&sdev->queue_stopped, 1, 0)) 2830 blk_mq_unquiesce_queue(sdev->request_queue); 2831 } 2832 2833 static void scsi_stop_queue(struct scsi_device *sdev) 2834 { 2835 /* 2836 * The atomic variable of ->queue_stopped covers that 2837 * blk_mq_quiesce_queue* is balanced with blk_mq_unquiesce_queue. 2838 * 2839 * The caller needs to wait until quiesce is done. 2840 */ 2841 if (!cmpxchg(&sdev->queue_stopped, 0, 1)) 2842 blk_mq_quiesce_queue_nowait(sdev->request_queue); 2843 } 2844 2845 /** 2846 * scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state 2847 * @sdev: device to block 2848 * 2849 * Pause SCSI command processing on the specified device. Does not sleep. 2850 * 2851 * Returns zero if successful or a negative error code upon failure. 2852 * 2853 * Notes: 2854 * This routine transitions the device to the SDEV_BLOCK state (which must be 2855 * a legal transition). When the device is in this state, command processing 2856 * is paused until the device leaves the SDEV_BLOCK state. See also 2857 * scsi_internal_device_unblock_nowait(). 2858 */ 2859 int scsi_internal_device_block_nowait(struct scsi_device *sdev) 2860 { 2861 int ret = __scsi_internal_device_block_nowait(sdev); 2862 2863 /* 2864 * The device has transitioned to SDEV_BLOCK. Stop the 2865 * block layer from calling the midlayer with this device's 2866 * request queue. 2867 */ 2868 if (!ret) 2869 scsi_stop_queue(sdev); 2870 return ret; 2871 } 2872 EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait); 2873 2874 /** 2875 * scsi_device_block - try to transition to the SDEV_BLOCK state 2876 * @sdev: device to block 2877 * @data: dummy argument, ignored 2878 * 2879 * Pause SCSI command processing on the specified device. Callers must wait 2880 * until all ongoing scsi_queue_rq() calls have finished after this function 2881 * returns. 2882 * 2883 * Note: 2884 * This routine transitions the device to the SDEV_BLOCK state (which must be 2885 * a legal transition). When the device is in this state, command processing 2886 * is paused until the device leaves the SDEV_BLOCK state. See also 2887 * scsi_internal_device_unblock(). 2888 */ 2889 static void scsi_device_block(struct scsi_device *sdev, void *data) 2890 { 2891 int err; 2892 enum scsi_device_state state; 2893 2894 mutex_lock(&sdev->state_mutex); 2895 err = __scsi_internal_device_block_nowait(sdev); 2896 state = sdev->sdev_state; 2897 if (err == 0) 2898 /* 2899 * scsi_stop_queue() must be called with the state_mutex 2900 * held. Otherwise a simultaneous scsi_start_queue() call 2901 * might unquiesce the queue before we quiesce it. 2902 */ 2903 scsi_stop_queue(sdev); 2904 2905 mutex_unlock(&sdev->state_mutex); 2906 2907 WARN_ONCE(err, "%s: failed to block %s in state %d\n", 2908 __func__, dev_name(&sdev->sdev_gendev), state); 2909 } 2910 2911 /** 2912 * scsi_internal_device_unblock_nowait - resume a device after a block request 2913 * @sdev: device to resume 2914 * @new_state: state to set the device to after unblocking 2915 * 2916 * Restart the device queue for a previously suspended SCSI device. Does not 2917 * sleep. 2918 * 2919 * Returns zero if successful or a negative error code upon failure. 2920 * 2921 * Notes: 2922 * This routine transitions the device to the SDEV_RUNNING state or to one of 2923 * the offline states (which must be a legal transition) allowing the midlayer 2924 * to goose the queue for this device. 2925 */ 2926 int scsi_internal_device_unblock_nowait(struct scsi_device *sdev, 2927 enum scsi_device_state new_state) 2928 { 2929 switch (new_state) { 2930 case SDEV_RUNNING: 2931 case SDEV_TRANSPORT_OFFLINE: 2932 break; 2933 default: 2934 return -EINVAL; 2935 } 2936 2937 /* 2938 * Try to transition the scsi device to SDEV_RUNNING or one of the 2939 * offlined states and goose the device queue if successful. 2940 */ 2941 switch (sdev->sdev_state) { 2942 case SDEV_BLOCK: 2943 case SDEV_TRANSPORT_OFFLINE: 2944 sdev->sdev_state = new_state; 2945 break; 2946 case SDEV_CREATED_BLOCK: 2947 if (new_state == SDEV_TRANSPORT_OFFLINE || 2948 new_state == SDEV_OFFLINE) 2949 sdev->sdev_state = new_state; 2950 else 2951 sdev->sdev_state = SDEV_CREATED; 2952 break; 2953 case SDEV_CANCEL: 2954 case SDEV_OFFLINE: 2955 break; 2956 default: 2957 return -EINVAL; 2958 } 2959 scsi_start_queue(sdev); 2960 2961 return 0; 2962 } 2963 EXPORT_SYMBOL_GPL(scsi_internal_device_unblock_nowait); 2964 2965 /** 2966 * scsi_internal_device_unblock - resume a device after a block request 2967 * @sdev: device to resume 2968 * @new_state: state to set the device to after unblocking 2969 * 2970 * Restart the device queue for a previously suspended SCSI device. May sleep. 2971 * 2972 * Returns zero if successful or a negative error code upon failure. 2973 * 2974 * Notes: 2975 * This routine transitions the device to the SDEV_RUNNING state or to one of 2976 * the offline states (which must be a legal transition) allowing the midlayer 2977 * to goose the queue for this device. 2978 */ 2979 static int scsi_internal_device_unblock(struct scsi_device *sdev, 2980 enum scsi_device_state new_state) 2981 { 2982 int ret; 2983 2984 mutex_lock(&sdev->state_mutex); 2985 ret = scsi_internal_device_unblock_nowait(sdev, new_state); 2986 mutex_unlock(&sdev->state_mutex); 2987 2988 return ret; 2989 } 2990 2991 static int 2992 target_block(struct device *dev, void *data) 2993 { 2994 if (scsi_is_target_device(dev)) 2995 starget_for_each_device(to_scsi_target(dev), NULL, 2996 scsi_device_block); 2997 return 0; 2998 } 2999 3000 /** 3001 * scsi_block_targets - transition all SCSI child devices to SDEV_BLOCK state 3002 * @dev: a parent device of one or more scsi_target devices 3003 * @shost: the Scsi_Host to which this device belongs 3004 * 3005 * Iterate over all children of @dev, which should be scsi_target devices, 3006 * and switch all subordinate scsi devices to SDEV_BLOCK state. Wait for 3007 * ongoing scsi_queue_rq() calls to finish. May sleep. 3008 * 3009 * Note: 3010 * @dev must not itself be a scsi_target device. 3011 */ 3012 void 3013 scsi_block_targets(struct Scsi_Host *shost, struct device *dev) 3014 { 3015 WARN_ON_ONCE(scsi_is_target_device(dev)); 3016 device_for_each_child(dev, NULL, target_block); 3017 blk_mq_wait_quiesce_done(&shost->tag_set); 3018 } 3019 EXPORT_SYMBOL_GPL(scsi_block_targets); 3020 3021 static void 3022 device_unblock(struct scsi_device *sdev, void *data) 3023 { 3024 scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data); 3025 } 3026 3027 static int 3028 target_unblock(struct device *dev, void *data) 3029 { 3030 if (scsi_is_target_device(dev)) 3031 starget_for_each_device(to_scsi_target(dev), data, 3032 device_unblock); 3033 return 0; 3034 } 3035 3036 void 3037 scsi_target_unblock(struct device *dev, enum scsi_device_state new_state) 3038 { 3039 if (scsi_is_target_device(dev)) 3040 starget_for_each_device(to_scsi_target(dev), &new_state, 3041 device_unblock); 3042 else 3043 device_for_each_child(dev, &new_state, target_unblock); 3044 } 3045 EXPORT_SYMBOL_GPL(scsi_target_unblock); 3046 3047 /** 3048 * scsi_host_block - Try to transition all logical units to the SDEV_BLOCK state 3049 * @shost: device to block 3050 * 3051 * Pause SCSI command processing for all logical units associated with the SCSI 3052 * host and wait until pending scsi_queue_rq() calls have finished. 3053 * 3054 * Returns zero if successful or a negative error code upon failure. 3055 */ 3056 int 3057 scsi_host_block(struct Scsi_Host *shost) 3058 { 3059 struct scsi_device *sdev; 3060 int ret; 3061 3062 /* 3063 * Call scsi_internal_device_block_nowait so we can avoid 3064 * calling synchronize_rcu() for each LUN. 3065 */ 3066 shost_for_each_device(sdev, shost) { 3067 mutex_lock(&sdev->state_mutex); 3068 ret = scsi_internal_device_block_nowait(sdev); 3069 mutex_unlock(&sdev->state_mutex); 3070 if (ret) { 3071 scsi_device_put(sdev); 3072 return ret; 3073 } 3074 } 3075 3076 /* Wait for ongoing scsi_queue_rq() calls to finish. */ 3077 blk_mq_wait_quiesce_done(&shost->tag_set); 3078 3079 return 0; 3080 } 3081 EXPORT_SYMBOL_GPL(scsi_host_block); 3082 3083 int 3084 scsi_host_unblock(struct Scsi_Host *shost, int new_state) 3085 { 3086 struct scsi_device *sdev; 3087 int ret = 0; 3088 3089 shost_for_each_device(sdev, shost) { 3090 ret = scsi_internal_device_unblock(sdev, new_state); 3091 if (ret) { 3092 scsi_device_put(sdev); 3093 break; 3094 } 3095 } 3096 return ret; 3097 } 3098 EXPORT_SYMBOL_GPL(scsi_host_unblock); 3099 3100 /** 3101 * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt 3102 * @sgl: scatter-gather list 3103 * @sg_count: number of segments in sg 3104 * @offset: offset in bytes into sg, on return offset into the mapped area 3105 * @len: bytes to map, on return number of bytes mapped 3106 * 3107 * Returns virtual address of the start of the mapped page 3108 */ 3109 void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count, 3110 size_t *offset, size_t *len) 3111 { 3112 int i; 3113 size_t sg_len = 0, len_complete = 0; 3114 struct scatterlist *sg; 3115 struct page *page; 3116 3117 WARN_ON(!irqs_disabled()); 3118 3119 for_each_sg(sgl, sg, sg_count, i) { 3120 len_complete = sg_len; /* Complete sg-entries */ 3121 sg_len += sg->length; 3122 if (sg_len > *offset) 3123 break; 3124 } 3125 3126 if (unlikely(i == sg_count)) { 3127 printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " 3128 "elements %d\n", 3129 __func__, sg_len, *offset, sg_count); 3130 WARN_ON(1); 3131 return NULL; 3132 } 3133 3134 /* Offset starting from the beginning of first page in this sg-entry */ 3135 *offset = *offset - len_complete + sg->offset; 3136 3137 /* Assumption: contiguous pages can be accessed as "page + i" */ 3138 page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT)); 3139 *offset &= ~PAGE_MASK; 3140 3141 /* Bytes in this sg-entry from *offset to the end of the page */ 3142 sg_len = PAGE_SIZE - *offset; 3143 if (*len > sg_len) 3144 *len = sg_len; 3145 3146 return kmap_atomic(page); 3147 } 3148 EXPORT_SYMBOL(scsi_kmap_atomic_sg); 3149 3150 /** 3151 * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg 3152 * @virt: virtual address to be unmapped 3153 */ 3154 void scsi_kunmap_atomic_sg(void *virt) 3155 { 3156 kunmap_atomic(virt); 3157 } 3158 EXPORT_SYMBOL(scsi_kunmap_atomic_sg); 3159 3160 void sdev_disable_disk_events(struct scsi_device *sdev) 3161 { 3162 atomic_inc(&sdev->disk_events_disable_depth); 3163 } 3164 EXPORT_SYMBOL(sdev_disable_disk_events); 3165 3166 void sdev_enable_disk_events(struct scsi_device *sdev) 3167 { 3168 if (WARN_ON_ONCE(atomic_read(&sdev->disk_events_disable_depth) <= 0)) 3169 return; 3170 atomic_dec(&sdev->disk_events_disable_depth); 3171 } 3172 EXPORT_SYMBOL(sdev_enable_disk_events); 3173 3174 static unsigned char designator_prio(const unsigned char *d) 3175 { 3176 if (d[1] & 0x30) 3177 /* not associated with LUN */ 3178 return 0; 3179 3180 if (d[3] == 0) 3181 /* invalid length */ 3182 return 0; 3183 3184 /* 3185 * Order of preference for lun descriptor: 3186 * - SCSI name string 3187 * - NAA IEEE Registered Extended 3188 * - EUI-64 based 16-byte 3189 * - EUI-64 based 12-byte 3190 * - NAA IEEE Registered 3191 * - NAA IEEE Extended 3192 * - EUI-64 based 8-byte 3193 * - SCSI name string (truncated) 3194 * - T10 Vendor ID 3195 * as longer descriptors reduce the likelyhood 3196 * of identification clashes. 3197 */ 3198 3199 switch (d[1] & 0xf) { 3200 case 8: 3201 /* SCSI name string, variable-length UTF-8 */ 3202 return 9; 3203 case 3: 3204 switch (d[4] >> 4) { 3205 case 6: 3206 /* NAA registered extended */ 3207 return 8; 3208 case 5: 3209 /* NAA registered */ 3210 return 5; 3211 case 4: 3212 /* NAA extended */ 3213 return 4; 3214 case 3: 3215 /* NAA locally assigned */ 3216 return 1; 3217 default: 3218 break; 3219 } 3220 break; 3221 case 2: 3222 switch (d[3]) { 3223 case 16: 3224 /* EUI64-based, 16 byte */ 3225 return 7; 3226 case 12: 3227 /* EUI64-based, 12 byte */ 3228 return 6; 3229 case 8: 3230 /* EUI64-based, 8 byte */ 3231 return 3; 3232 default: 3233 break; 3234 } 3235 break; 3236 case 1: 3237 /* T10 vendor ID */ 3238 return 1; 3239 default: 3240 break; 3241 } 3242 3243 return 0; 3244 } 3245 3246 /** 3247 * scsi_vpd_lun_id - return a unique device identification 3248 * @sdev: SCSI device 3249 * @id: buffer for the identification 3250 * @id_len: length of the buffer 3251 * 3252 * Copies a unique device identification into @id based 3253 * on the information in the VPD page 0x83 of the device. 3254 * The string will be formatted as a SCSI name string. 3255 * 3256 * Returns the length of the identification or error on failure. 3257 * If the identifier is longer than the supplied buffer the actual 3258 * identifier length is returned and the buffer is not zero-padded. 3259 */ 3260 int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len) 3261 { 3262 u8 cur_id_prio = 0; 3263 u8 cur_id_size = 0; 3264 const unsigned char *d, *cur_id_str; 3265 const struct scsi_vpd *vpd_pg83; 3266 int id_size = -EINVAL; 3267 3268 rcu_read_lock(); 3269 vpd_pg83 = rcu_dereference(sdev->vpd_pg83); 3270 if (!vpd_pg83) { 3271 rcu_read_unlock(); 3272 return -ENXIO; 3273 } 3274 3275 /* The id string must be at least 20 bytes + terminating NULL byte */ 3276 if (id_len < 21) { 3277 rcu_read_unlock(); 3278 return -EINVAL; 3279 } 3280 3281 memset(id, 0, id_len); 3282 for (d = vpd_pg83->data + 4; 3283 d < vpd_pg83->data + vpd_pg83->len; 3284 d += d[3] + 4) { 3285 u8 prio = designator_prio(d); 3286 3287 if (prio == 0 || cur_id_prio > prio) 3288 continue; 3289 3290 switch (d[1] & 0xf) { 3291 case 0x1: 3292 /* T10 Vendor ID */ 3293 if (cur_id_size > d[3]) 3294 break; 3295 cur_id_prio = prio; 3296 cur_id_size = d[3]; 3297 if (cur_id_size + 4 > id_len) 3298 cur_id_size = id_len - 4; 3299 cur_id_str = d + 4; 3300 id_size = snprintf(id, id_len, "t10.%*pE", 3301 cur_id_size, cur_id_str); 3302 break; 3303 case 0x2: 3304 /* EUI-64 */ 3305 cur_id_prio = prio; 3306 cur_id_size = d[3]; 3307 cur_id_str = d + 4; 3308 switch (cur_id_size) { 3309 case 8: 3310 id_size = snprintf(id, id_len, 3311 "eui.%8phN", 3312 cur_id_str); 3313 break; 3314 case 12: 3315 id_size = snprintf(id, id_len, 3316 "eui.%12phN", 3317 cur_id_str); 3318 break; 3319 case 16: 3320 id_size = snprintf(id, id_len, 3321 "eui.%16phN", 3322 cur_id_str); 3323 break; 3324 default: 3325 break; 3326 } 3327 break; 3328 case 0x3: 3329 /* NAA */ 3330 cur_id_prio = prio; 3331 cur_id_size = d[3]; 3332 cur_id_str = d + 4; 3333 switch (cur_id_size) { 3334 case 8: 3335 id_size = snprintf(id, id_len, 3336 "naa.%8phN", 3337 cur_id_str); 3338 break; 3339 case 16: 3340 id_size = snprintf(id, id_len, 3341 "naa.%16phN", 3342 cur_id_str); 3343 break; 3344 default: 3345 break; 3346 } 3347 break; 3348 case 0x8: 3349 /* SCSI name string */ 3350 if (cur_id_size > d[3]) 3351 break; 3352 /* Prefer others for truncated descriptor */ 3353 if (d[3] > id_len) { 3354 prio = 2; 3355 if (cur_id_prio > prio) 3356 break; 3357 } 3358 cur_id_prio = prio; 3359 cur_id_size = id_size = d[3]; 3360 cur_id_str = d + 4; 3361 if (cur_id_size >= id_len) 3362 cur_id_size = id_len - 1; 3363 memcpy(id, cur_id_str, cur_id_size); 3364 break; 3365 default: 3366 break; 3367 } 3368 } 3369 rcu_read_unlock(); 3370 3371 return id_size; 3372 } 3373 EXPORT_SYMBOL(scsi_vpd_lun_id); 3374 3375 /* 3376 * scsi_vpd_tpg_id - return a target port group identifier 3377 * @sdev: SCSI device 3378 * 3379 * Returns the Target Port Group identifier from the information 3380 * froom VPD page 0x83 of the device. 3381 * 3382 * Returns the identifier or error on failure. 3383 */ 3384 int scsi_vpd_tpg_id(struct scsi_device *sdev, int *rel_id) 3385 { 3386 const unsigned char *d; 3387 const struct scsi_vpd *vpd_pg83; 3388 int group_id = -EAGAIN, rel_port = -1; 3389 3390 rcu_read_lock(); 3391 vpd_pg83 = rcu_dereference(sdev->vpd_pg83); 3392 if (!vpd_pg83) { 3393 rcu_read_unlock(); 3394 return -ENXIO; 3395 } 3396 3397 d = vpd_pg83->data + 4; 3398 while (d < vpd_pg83->data + vpd_pg83->len) { 3399 switch (d[1] & 0xf) { 3400 case 0x4: 3401 /* Relative target port */ 3402 rel_port = get_unaligned_be16(&d[6]); 3403 break; 3404 case 0x5: 3405 /* Target port group */ 3406 group_id = get_unaligned_be16(&d[6]); 3407 break; 3408 default: 3409 break; 3410 } 3411 d += d[3] + 4; 3412 } 3413 rcu_read_unlock(); 3414 3415 if (group_id >= 0 && rel_id && rel_port != -1) 3416 *rel_id = rel_port; 3417 3418 return group_id; 3419 } 3420 EXPORT_SYMBOL(scsi_vpd_tpg_id); 3421 3422 /** 3423 * scsi_build_sense - build sense data for a command 3424 * @scmd: scsi command for which the sense should be formatted 3425 * @desc: Sense format (non-zero == descriptor format, 3426 * 0 == fixed format) 3427 * @key: Sense key 3428 * @asc: Additional sense code 3429 * @ascq: Additional sense code qualifier 3430 * 3431 **/ 3432 void scsi_build_sense(struct scsi_cmnd *scmd, int desc, u8 key, u8 asc, u8 ascq) 3433 { 3434 scsi_build_sense_buffer(desc, scmd->sense_buffer, key, asc, ascq); 3435 scmd->result = SAM_STAT_CHECK_CONDITION; 3436 } 3437 EXPORT_SYMBOL_GPL(scsi_build_sense); 3438 3439 #ifdef CONFIG_SCSI_LIB_KUNIT_TEST 3440 #include "scsi_lib_test.c" 3441 #endif 3442