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