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scsi_lib.c
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linux-6.19.14/drivers/scsi/scsi_lib.c
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 <linux/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 56static struct kmem_cache *scsi_sense_cache; 57static DEFINE_MUTEX(scsi_sense_cache_mutex); 58 59static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd); 60 61int 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 78static void 79scsi_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 114static 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 */ 142static 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 */ 182void scsi_queue_insert(struct scsi_cmnd *cmd, int reason) 183{ 184 __scsi_queue_insert(cmd, reason, true); 185} 186 187/** 188 * scsi_failures_reset_retries - reset all failures to zero 189 * @failures: &struct scsi_failures with specific failure modes set 190 */ 191void scsi_failures_reset_retries(struct scsi_failures *failures) 192{ 193 struct scsi_failure *failure; 194 195 failures->total_retries = 0; 196 197 for (failure = failures->failure_definitions; failure->result; 198 failure++) 199 failure->retries = 0; 200} 201EXPORT_SYMBOL_GPL(scsi_failures_reset_retries); 202 203/** 204 * scsi_check_passthrough - Determine if passthrough scsi_cmnd needs a retry. 205 * @scmd: scsi_cmnd to check. 206 * @failures: scsi_failures struct that lists failures to check for. 207 * 208 * Returns -EAGAIN if the caller should retry else 0. 209 */ 210static int scsi_check_passthrough(struct scsi_cmnd *scmd, 211 struct scsi_failures *failures) 212{ 213 struct scsi_failure *failure; 214 struct scsi_sense_hdr sshdr; 215 enum sam_status status; 216 217 if (!scmd->result) 218 return 0; 219 220 if (!failures) 221 return 0; 222 223 for (failure = failures->failure_definitions; failure->result; 224 failure++) { 225 if (failure->result == SCMD_FAILURE_RESULT_ANY) 226 goto maybe_retry; 227 228 if (host_byte(scmd->result) && 229 host_byte(scmd->result) == host_byte(failure->result)) 230 goto maybe_retry; 231 232 status = status_byte(scmd->result); 233 if (!status) 234 continue; 235 236 if (failure->result == SCMD_FAILURE_STAT_ANY && 237 !scsi_status_is_good(scmd->result)) 238 goto maybe_retry; 239 240 if (status != status_byte(failure->result)) 241 continue; 242 243 if (status_byte(failure->result) != SAM_STAT_CHECK_CONDITION || 244 failure->sense == SCMD_FAILURE_SENSE_ANY) 245 goto maybe_retry; 246 247 if (!scsi_command_normalize_sense(scmd, &sshdr)) 248 return 0; 249 250 if (failure->sense != sshdr.sense_key) 251 continue; 252 253 if (failure->asc == SCMD_FAILURE_ASC_ANY) 254 goto maybe_retry; 255 256 if (failure->asc != sshdr.asc) 257 continue; 258 259 if (failure->ascq == SCMD_FAILURE_ASCQ_ANY || 260 failure->ascq == sshdr.ascq) 261 goto maybe_retry; 262 } 263 264 return 0; 265 266maybe_retry: 267 if (failure->allowed) { 268 if (failure->allowed == SCMD_FAILURE_NO_LIMIT || 269 ++failure->retries <= failure->allowed) 270 return -EAGAIN; 271 } else { 272 if (failures->total_allowed == SCMD_FAILURE_NO_LIMIT || 273 ++failures->total_retries <= failures->total_allowed) 274 return -EAGAIN; 275 } 276 277 return 0; 278} 279 280/** 281 * scsi_execute_cmd - insert request and wait for the result 282 * @sdev: scsi_device 283 * @cmd: scsi command 284 * @opf: block layer request cmd_flags 285 * @buffer: data buffer 286 * @bufflen: len of buffer 287 * @timeout: request timeout in HZ 288 * @ml_retries: number of times SCSI midlayer will retry request 289 * @args: Optional args. See struct definition for field descriptions 290 * 291 * Returns the scsi_cmnd result field if a command was executed, or a negative 292 * Linux error code if we didn't get that far. 293 */ 294int scsi_execute_cmd(struct scsi_device *sdev, const unsigned char *cmd, 295 blk_opf_t opf, void *buffer, unsigned int bufflen, 296 int timeout, int ml_retries, 297 const struct scsi_exec_args *args) 298{ 299 static const struct scsi_exec_args default_args; 300 struct request *req; 301 struct scsi_cmnd *scmd; 302 int ret; 303 304 if (!args) 305 args = &default_args; 306 else if (WARN_ON_ONCE(args->sense && 307 args->sense_len != SCSI_SENSE_BUFFERSIZE)) 308 return -EINVAL; 309 310retry: 311 req = scsi_alloc_request(sdev->request_queue, opf, args->req_flags); 312 if (IS_ERR(req)) 313 return PTR_ERR(req); 314 315 if (bufflen) { 316 ret = blk_rq_map_kern(req, buffer, bufflen, GFP_NOIO); 317 if (ret) 318 goto out; 319 } 320 scmd = blk_mq_rq_to_pdu(req); 321 scmd->cmd_len = COMMAND_SIZE(cmd[0]); 322 memcpy(scmd->cmnd, cmd, scmd->cmd_len); 323 scmd->allowed = ml_retries; 324 scmd->flags |= args->scmd_flags; 325 req->timeout = timeout; 326 req->rq_flags |= RQF_QUIET; 327 328 /* 329 * head injection *required* here otherwise quiesce won't work 330 */ 331 blk_execute_rq(req, true); 332 333 if (scsi_check_passthrough(scmd, args->failures) == -EAGAIN) { 334 blk_mq_free_request(req); 335 goto retry; 336 } 337 338 /* 339 * Some devices (USB mass-storage in particular) may transfer 340 * garbage data together with a residue indicating that the data 341 * is invalid. Prevent the garbage from being misinterpreted 342 * and prevent security leaks by zeroing out the excess data. 343 */ 344 if (unlikely(scmd->resid_len > 0 && scmd->resid_len <= bufflen)) 345 memset(buffer + bufflen - scmd->resid_len, 0, scmd->resid_len); 346 347 if (args->resid) 348 *args->resid = scmd->resid_len; 349 if (args->sense) 350 memcpy(args->sense, scmd->sense_buffer, SCSI_SENSE_BUFFERSIZE); 351 if (args->sshdr) 352 scsi_normalize_sense(scmd->sense_buffer, scmd->sense_len, 353 args->sshdr); 354 355 ret = scmd->result; 356 out: 357 blk_mq_free_request(req); 358 359 return ret; 360} 361EXPORT_SYMBOL(scsi_execute_cmd); 362 363/* 364 * Wake up the error handler if necessary. Avoid as follows that the error 365 * handler is not woken up if host in-flight requests number == 366 * shost->host_failed: use call_rcu() in scsi_eh_scmd_add() in combination 367 * with an RCU read lock in this function to ensure that this function in 368 * its entirety either finishes before scsi_eh_scmd_add() increases the 369 * host_failed counter or that it notices the shost state change made by 370 * scsi_eh_scmd_add(). 371 */ 372static void scsi_dec_host_busy(struct Scsi_Host *shost, struct scsi_cmnd *cmd) 373{ 374 unsigned long flags; 375 376 rcu_read_lock(); 377 __clear_bit(SCMD_STATE_INFLIGHT, &cmd->state); 378 if (unlikely(scsi_host_in_recovery(shost))) { 379 /* 380 * Ensure the clear of SCMD_STATE_INFLIGHT is visible to 381 * other CPUs before counting busy requests. Otherwise, 382 * reordering can cause CPUs to race and miss an eh wakeup 383 * when no CPU sees all busy requests as done or timed out. 384 */ 385 smp_mb(); 386 387 unsigned int busy = scsi_host_busy(shost); 388 389 spin_lock_irqsave(shost->host_lock, flags); 390 if (shost->host_failed || shost->host_eh_scheduled) 391 scsi_eh_wakeup(shost, busy); 392 spin_unlock_irqrestore(shost->host_lock, flags); 393 } 394 rcu_read_unlock(); 395} 396 397void scsi_device_unbusy(struct scsi_device *sdev, struct scsi_cmnd *cmd) 398{ 399 struct Scsi_Host *shost = sdev->host; 400 struct scsi_target *starget = scsi_target(sdev); 401 402 scsi_dec_host_busy(shost, cmd); 403 404 if (starget->can_queue > 0) 405 atomic_dec(&starget->target_busy); 406 407 if (sdev->budget_map.map) 408 sbitmap_put(&sdev->budget_map, cmd->budget_token); 409 cmd->budget_token = -1; 410} 411 412/* 413 * Kick the queue of SCSI device @sdev if @sdev != current_sdev. Called with 414 * interrupts disabled. 415 */ 416static void scsi_kick_sdev_queue(struct scsi_device *sdev, void *data) 417{ 418 struct scsi_device *current_sdev = data; 419 420 if (sdev != current_sdev) 421 blk_mq_run_hw_queues(sdev->request_queue, true); 422} 423 424/* 425 * Called for single_lun devices on IO completion. Clear starget_sdev_user, 426 * and call blk_run_queue for all the scsi_devices on the target - 427 * including current_sdev first. 428 * 429 * Called with *no* scsi locks held. 430 */ 431static void scsi_single_lun_run(struct scsi_device *current_sdev) 432{ 433 struct Scsi_Host *shost = current_sdev->host; 434 struct scsi_target *starget = scsi_target(current_sdev); 435 unsigned long flags; 436 437 spin_lock_irqsave(shost->host_lock, flags); 438 starget->starget_sdev_user = NULL; 439 spin_unlock_irqrestore(shost->host_lock, flags); 440 441 /* 442 * Call blk_run_queue for all LUNs on the target, starting with 443 * current_sdev. We race with others (to set starget_sdev_user), 444 * but in most cases, we will be first. Ideally, each LU on the 445 * target would get some limited time or requests on the target. 446 */ 447 blk_mq_run_hw_queues(current_sdev->request_queue, 448 shost->queuecommand_may_block); 449 450 spin_lock_irqsave(shost->host_lock, flags); 451 if (!starget->starget_sdev_user) 452 __starget_for_each_device(starget, current_sdev, 453 scsi_kick_sdev_queue); 454 spin_unlock_irqrestore(shost->host_lock, flags); 455} 456 457static inline bool scsi_device_is_busy(struct scsi_device *sdev) 458{ 459 if (scsi_device_busy(sdev) >= sdev->queue_depth) 460 return true; 461 if (atomic_read(&sdev->device_blocked) > 0) 462 return true; 463 return false; 464} 465 466static inline bool scsi_target_is_busy(struct scsi_target *starget) 467{ 468 if (starget->can_queue > 0) { 469 if (atomic_read(&starget->target_busy) >= starget->can_queue) 470 return true; 471 if (atomic_read(&starget->target_blocked) > 0) 472 return true; 473 } 474 return false; 475} 476 477static inline bool scsi_host_is_busy(struct Scsi_Host *shost) 478{ 479 if (atomic_read(&shost->host_blocked) > 0) 480 return true; 481 if (shost->host_self_blocked) 482 return true; 483 return false; 484} 485 486static void scsi_starved_list_run(struct Scsi_Host *shost) 487{ 488 LIST_HEAD(starved_list); 489 struct scsi_device *sdev; 490 unsigned long flags; 491 492 spin_lock_irqsave(shost->host_lock, flags); 493 list_splice_init(&shost->starved_list, &starved_list); 494 495 while (!list_empty(&starved_list)) { 496 struct request_queue *slq; 497 498 /* 499 * As long as shost is accepting commands and we have 500 * starved queues, call blk_run_queue. scsi_request_fn 501 * drops the queue_lock and can add us back to the 502 * starved_list. 503 * 504 * host_lock protects the starved_list and starved_entry. 505 * scsi_request_fn must get the host_lock before checking 506 * or modifying starved_list or starved_entry. 507 */ 508 if (scsi_host_is_busy(shost)) 509 break; 510 511 sdev = list_entry(starved_list.next, 512 struct scsi_device, starved_entry); 513 list_del_init(&sdev->starved_entry); 514 if (scsi_target_is_busy(scsi_target(sdev))) { 515 list_move_tail(&sdev->starved_entry, 516 &shost->starved_list); 517 continue; 518 } 519 520 /* 521 * Once we drop the host lock, a racing scsi_remove_device() 522 * call may remove the sdev from the starved list and destroy 523 * it and the queue. Mitigate by taking a reference to the 524 * queue and never touching the sdev again after we drop the 525 * host lock. Note: if __scsi_remove_device() invokes 526 * blk_mq_destroy_queue() before the queue is run from this 527 * function then blk_run_queue() will return immediately since 528 * blk_mq_destroy_queue() marks the queue with QUEUE_FLAG_DYING. 529 */ 530 slq = sdev->request_queue; 531 if (!blk_get_queue(slq)) 532 continue; 533 spin_unlock_irqrestore(shost->host_lock, flags); 534 535 blk_mq_run_hw_queues(slq, false); 536 blk_put_queue(slq); 537 538 spin_lock_irqsave(shost->host_lock, flags); 539 } 540 /* put any unprocessed entries back */ 541 list_splice(&starved_list, &shost->starved_list); 542 spin_unlock_irqrestore(shost->host_lock, flags); 543} 544 545/** 546 * scsi_run_queue - Select a proper request queue to serve next. 547 * @q: last request's queue 548 * 549 * The previous command was completely finished, start a new one if possible. 550 */ 551static void scsi_run_queue(struct request_queue *q) 552{ 553 struct scsi_device *sdev = q->queuedata; 554 555 if (scsi_target(sdev)->single_lun) 556 scsi_single_lun_run(sdev); 557 if (!list_empty(&sdev->host->starved_list)) 558 scsi_starved_list_run(sdev->host); 559 560 /* Note: blk_mq_kick_requeue_list() runs the queue asynchronously. */ 561 blk_mq_kick_requeue_list(q); 562} 563 564void scsi_requeue_run_queue(struct work_struct *work) 565{ 566 struct scsi_device *sdev; 567 struct request_queue *q; 568 569 sdev = container_of(work, struct scsi_device, requeue_work); 570 q = sdev->request_queue; 571 scsi_run_queue(q); 572} 573 574void scsi_run_host_queues(struct Scsi_Host *shost) 575{ 576 struct scsi_device *sdev; 577 578 shost_for_each_device(sdev, shost) 579 scsi_run_queue(sdev->request_queue); 580} 581 582static void scsi_uninit_cmd(struct scsi_cmnd *cmd) 583{ 584 if (!blk_rq_is_passthrough(scsi_cmd_to_rq(cmd))) { 585 struct scsi_driver *drv = scsi_cmd_to_driver(cmd); 586 587 if (drv->uninit_command) 588 drv->uninit_command(cmd); 589 } 590} 591 592void scsi_free_sgtables(struct scsi_cmnd *cmd) 593{ 594 if (cmd->sdb.table.nents) 595 sg_free_table_chained(&cmd->sdb.table, 596 SCSI_INLINE_SG_CNT); 597 if (scsi_prot_sg_count(cmd)) 598 sg_free_table_chained(&cmd->prot_sdb->table, 599 SCSI_INLINE_PROT_SG_CNT); 600} 601EXPORT_SYMBOL_GPL(scsi_free_sgtables); 602 603static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd) 604{ 605 scsi_free_sgtables(cmd); 606 scsi_uninit_cmd(cmd); 607} 608 609static void scsi_run_queue_async(struct scsi_device *sdev) 610{ 611 if (scsi_host_in_recovery(sdev->host)) 612 return; 613 614 if (scsi_target(sdev)->single_lun || 615 !list_empty(&sdev->host->starved_list)) { 616 kblockd_schedule_work(&sdev->requeue_work); 617 } else { 618 /* 619 * smp_mb() present in sbitmap_queue_clear() or implied in 620 * .end_io is for ordering writing .device_busy in 621 * scsi_device_unbusy() and reading sdev->restarts. 622 */ 623 int old = atomic_read(&sdev->restarts); 624 625 /* 626 * ->restarts has to be kept as non-zero if new budget 627 * contention occurs. 628 * 629 * No need to run queue when either another re-run 630 * queue wins in updating ->restarts or a new budget 631 * contention occurs. 632 */ 633 if (old && atomic_cmpxchg(&sdev->restarts, old, 0) == old) 634 blk_mq_run_hw_queues(sdev->request_queue, true); 635 } 636} 637 638/* Returns false when no more bytes to process, true if there are more */ 639static bool scsi_end_request(struct request *req, blk_status_t error, 640 unsigned int bytes) 641{ 642 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); 643 struct scsi_device *sdev = cmd->device; 644 struct request_queue *q = sdev->request_queue; 645 646 if (blk_update_request(req, error, bytes)) 647 return true; 648 649 if (q->limits.features & BLK_FEAT_ADD_RANDOM) 650 add_disk_randomness(req->q->disk); 651 652 WARN_ON_ONCE(!blk_rq_is_passthrough(req) && 653 !(cmd->flags & SCMD_INITIALIZED)); 654 cmd->flags = 0; 655 656 /* 657 * Calling rcu_barrier() is not necessary here because the 658 * SCSI error handler guarantees that the function called by 659 * call_rcu() has been called before scsi_end_request() is 660 * called. 661 */ 662 destroy_rcu_head(&cmd->rcu); 663 664 /* 665 * In the MQ case the command gets freed by __blk_mq_end_request, 666 * so we have to do all cleanup that depends on it earlier. 667 * 668 * We also can't kick the queues from irq context, so we 669 * will have to defer it to a workqueue. 670 */ 671 scsi_mq_uninit_cmd(cmd); 672 673 /* 674 * queue is still alive, so grab the ref for preventing it 675 * from being cleaned up during running queue. 676 */ 677 percpu_ref_get(&q->q_usage_counter); 678 679 __blk_mq_end_request(req, error); 680 681 scsi_run_queue_async(sdev); 682 683 percpu_ref_put(&q->q_usage_counter); 684 return false; 685} 686 687/** 688 * scsi_result_to_blk_status - translate a SCSI result code into blk_status_t 689 * @result: scsi error code 690 * 691 * Translate a SCSI result code into a blk_status_t value. 692 */ 693static blk_status_t scsi_result_to_blk_status(int result) 694{ 695 /* 696 * Check the scsi-ml byte first in case we converted a host or status 697 * byte. 698 */ 699 switch (scsi_ml_byte(result)) { 700 case SCSIML_STAT_OK: 701 break; 702 case SCSIML_STAT_RESV_CONFLICT: 703 return BLK_STS_RESV_CONFLICT; 704 case SCSIML_STAT_NOSPC: 705 return BLK_STS_NOSPC; 706 case SCSIML_STAT_MED_ERROR: 707 return BLK_STS_MEDIUM; 708 case SCSIML_STAT_TGT_FAILURE: 709 return BLK_STS_TARGET; 710 case SCSIML_STAT_DL_TIMEOUT: 711 return BLK_STS_DURATION_LIMIT; 712 } 713 714 switch (host_byte(result)) { 715 case DID_OK: 716 if (scsi_status_is_good(result)) 717 return BLK_STS_OK; 718 return BLK_STS_IOERR; 719 case DID_TRANSPORT_FAILFAST: 720 case DID_TRANSPORT_MARGINAL: 721 return BLK_STS_TRANSPORT; 722 default: 723 return BLK_STS_IOERR; 724 } 725} 726 727/** 728 * scsi_rq_err_bytes - determine number of bytes till the next failure boundary 729 * @rq: request to examine 730 * 731 * Description: 732 * A request could be merge of IOs which require different failure 733 * handling. This function determines the number of bytes which 734 * can be failed from the beginning of the request without 735 * crossing into area which need to be retried further. 736 * 737 * Return: 738 * The number of bytes to fail. 739 */ 740static unsigned int scsi_rq_err_bytes(const struct request *rq) 741{ 742 blk_opf_t ff = rq->cmd_flags & REQ_FAILFAST_MASK; 743 unsigned int bytes = 0; 744 struct bio *bio; 745 746 if (!(rq->rq_flags & RQF_MIXED_MERGE)) 747 return blk_rq_bytes(rq); 748 749 /* 750 * Currently the only 'mixing' which can happen is between 751 * different fastfail types. We can safely fail portions 752 * which have all the failfast bits that the first one has - 753 * the ones which are at least as eager to fail as the first 754 * one. 755 */ 756 for (bio = rq->bio; bio; bio = bio->bi_next) { 757 if ((bio->bi_opf & ff) != ff) 758 break; 759 bytes += bio->bi_iter.bi_size; 760 } 761 762 /* this could lead to infinite loop */ 763 BUG_ON(blk_rq_bytes(rq) && !bytes); 764 return bytes; 765} 766 767static bool scsi_cmd_runtime_exceeced(struct scsi_cmnd *cmd) 768{ 769 struct request *req = scsi_cmd_to_rq(cmd); 770 unsigned long wait_for; 771 772 if (cmd->allowed == SCSI_CMD_RETRIES_NO_LIMIT) 773 return false; 774 775 wait_for = (cmd->allowed + 1) * req->timeout; 776 if (time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { 777 scmd_printk(KERN_ERR, cmd, "timing out command, waited %lus\n", 778 wait_for/HZ); 779 return true; 780 } 781 return false; 782} 783 784/* 785 * When ALUA transition state is returned, reprep the cmd to 786 * use the ALUA handler's transition timeout. Delay the reprep 787 * 1 sec to avoid aggressive retries of the target in that 788 * state. 789 */ 790#define ALUA_TRANSITION_REPREP_DELAY 1000 791 792/* Helper for scsi_io_completion() when special action required. */ 793static void scsi_io_completion_action(struct scsi_cmnd *cmd, int result) 794{ 795 struct request *req = scsi_cmd_to_rq(cmd); 796 int level = 0; 797 enum {ACTION_FAIL, ACTION_REPREP, ACTION_DELAYED_REPREP, 798 ACTION_RETRY, ACTION_DELAYED_RETRY} action; 799 struct scsi_sense_hdr sshdr; 800 bool sense_valid; 801 bool sense_current = true; /* false implies "deferred sense" */ 802 blk_status_t blk_stat; 803 804 sense_valid = scsi_command_normalize_sense(cmd, &sshdr); 805 if (sense_valid) 806 sense_current = !scsi_sense_is_deferred(&sshdr); 807 808 blk_stat = scsi_result_to_blk_status(result); 809 810 if (host_byte(result) == DID_RESET) { 811 /* Third party bus reset or reset for error recovery 812 * reasons. Just retry the command and see what 813 * happens. 814 */ 815 action = ACTION_RETRY; 816 } else if (sense_valid && sense_current) { 817 switch (sshdr.sense_key) { 818 case UNIT_ATTENTION: 819 if (cmd->device->removable) { 820 /* Detected disc change. Set a bit 821 * and quietly refuse further access. 822 */ 823 cmd->device->changed = 1; 824 action = ACTION_FAIL; 825 } else { 826 /* Must have been a power glitch, or a 827 * bus reset. Could not have been a 828 * media change, so we just retry the 829 * command and see what happens. 830 */ 831 action = ACTION_RETRY; 832 } 833 break; 834 case ILLEGAL_REQUEST: 835 /* If we had an ILLEGAL REQUEST returned, then 836 * we may have performed an unsupported 837 * command. The only thing this should be 838 * would be a ten byte read where only a six 839 * byte read was supported. Also, on a system 840 * where READ CAPACITY failed, we may have 841 * read past the end of the disk. 842 */ 843 if ((cmd->device->use_10_for_rw && 844 sshdr.asc == 0x20 && sshdr.ascq == 0x00) && 845 (cmd->cmnd[0] == READ_10 || 846 cmd->cmnd[0] == WRITE_10)) { 847 /* This will issue a new 6-byte command. */ 848 cmd->device->use_10_for_rw = 0; 849 action = ACTION_REPREP; 850 } else if (sshdr.asc == 0x10) /* DIX */ { 851 action = ACTION_FAIL; 852 blk_stat = BLK_STS_PROTECTION; 853 /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */ 854 } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) { 855 action = ACTION_FAIL; 856 blk_stat = BLK_STS_TARGET; 857 } else 858 action = ACTION_FAIL; 859 break; 860 case ABORTED_COMMAND: 861 action = ACTION_FAIL; 862 if (sshdr.asc == 0x10) /* DIF */ 863 blk_stat = BLK_STS_PROTECTION; 864 break; 865 case NOT_READY: 866 /* If the device is in the process of becoming 867 * ready, or has a temporary blockage, retry. 868 */ 869 if (sshdr.asc == 0x04) { 870 switch (sshdr.ascq) { 871 case 0x01: /* becoming ready */ 872 case 0x04: /* format in progress */ 873 case 0x05: /* rebuild in progress */ 874 case 0x06: /* recalculation in progress */ 875 case 0x07: /* operation in progress */ 876 case 0x08: /* Long write in progress */ 877 case 0x09: /* self test in progress */ 878 case 0x11: /* notify (enable spinup) required */ 879 case 0x14: /* space allocation in progress */ 880 case 0x1a: /* start stop unit in progress */ 881 case 0x1b: /* sanitize in progress */ 882 case 0x1d: /* configuration in progress */ 883 action = ACTION_DELAYED_RETRY; 884 break; 885 case 0x0a: /* ALUA state transition */ 886 action = ACTION_DELAYED_REPREP; 887 break; 888 /* 889 * Depopulation might take many hours, 890 * thus it is not worthwhile to retry. 891 */ 892 case 0x24: /* depopulation in progress */ 893 case 0x25: /* depopulation restore in progress */ 894 fallthrough; 895 default: 896 action = ACTION_FAIL; 897 break; 898 } 899 } else 900 action = ACTION_FAIL; 901 break; 902 case VOLUME_OVERFLOW: 903 /* See SSC3rXX or current. */ 904 action = ACTION_FAIL; 905 break; 906 case DATA_PROTECT: 907 action = ACTION_FAIL; 908 if ((sshdr.asc == 0x0C && sshdr.ascq == 0x12) || 909 (sshdr.asc == 0x55 && 910 (sshdr.ascq == 0x0E || sshdr.ascq == 0x0F))) { 911 /* Insufficient zone resources */ 912 blk_stat = BLK_STS_ZONE_OPEN_RESOURCE; 913 } 914 break; 915 case COMPLETED: 916 fallthrough; 917 default: 918 action = ACTION_FAIL; 919 break; 920 } 921 } else 922 action = ACTION_FAIL; 923 924 if (action != ACTION_FAIL && scsi_cmd_runtime_exceeced(cmd)) 925 action = ACTION_FAIL; 926 927 switch (action) { 928 case ACTION_FAIL: 929 /* Give up and fail the remainder of the request */ 930 if (!(req->rq_flags & RQF_QUIET)) { 931 static DEFINE_RATELIMIT_STATE(_rs, 932 DEFAULT_RATELIMIT_INTERVAL, 933 DEFAULT_RATELIMIT_BURST); 934 935 if (unlikely(scsi_logging_level)) 936 level = 937 SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, 938 SCSI_LOG_MLCOMPLETE_BITS); 939 940 /* 941 * if logging is enabled the failure will be printed 942 * in scsi_log_completion(), so avoid duplicate messages 943 */ 944 if (!level && __ratelimit(&_rs)) { 945 scsi_print_result(cmd, NULL, FAILED); 946 if (sense_valid) 947 scsi_print_sense(cmd); 948 scsi_print_command(cmd); 949 } 950 } 951 if (!scsi_end_request(req, blk_stat, scsi_rq_err_bytes(req))) 952 return; 953 fallthrough; 954 case ACTION_REPREP: 955 scsi_mq_requeue_cmd(cmd, 0); 956 break; 957 case ACTION_DELAYED_REPREP: 958 scsi_mq_requeue_cmd(cmd, ALUA_TRANSITION_REPREP_DELAY); 959 break; 960 case ACTION_RETRY: 961 /* Retry the same command immediately */ 962 __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, false); 963 break; 964 case ACTION_DELAYED_RETRY: 965 /* Retry the same command after a delay */ 966 __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, false); 967 break; 968 } 969} 970 971/* 972 * Helper for scsi_io_completion() when cmd->result is non-zero. Returns a 973 * new result that may suppress further error checking. Also modifies 974 * *blk_statp in some cases. 975 */ 976static int scsi_io_completion_nz_result(struct scsi_cmnd *cmd, int result, 977 blk_status_t *blk_statp) 978{ 979 bool sense_valid; 980 bool sense_current = true; /* false implies "deferred sense" */ 981 struct request *req = scsi_cmd_to_rq(cmd); 982 struct scsi_sense_hdr sshdr; 983 984 sense_valid = scsi_command_normalize_sense(cmd, &sshdr); 985 if (sense_valid) 986 sense_current = !scsi_sense_is_deferred(&sshdr); 987 988 if (blk_rq_is_passthrough(req)) { 989 if (sense_valid) { 990 /* 991 * SG_IO wants current and deferred errors 992 */ 993 cmd->sense_len = min(8 + cmd->sense_buffer[7], 994 SCSI_SENSE_BUFFERSIZE); 995 } 996 if (sense_current) 997 *blk_statp = scsi_result_to_blk_status(result); 998 } else if (blk_rq_bytes(req) == 0 && sense_current) { 999 /* 1000 * Flush commands do not transfers any data, and thus cannot use 1001 * good_bytes != blk_rq_bytes(req) as the signal for an error. 1002 * This sets *blk_statp explicitly for the problem case. 1003 */ 1004 *blk_statp = scsi_result_to_blk_status(result); 1005 } 1006 /* 1007 * Recovered errors need reporting, but they're always treated as 1008 * success, so fiddle the result code here. For passthrough requests 1009 * we already took a copy of the original into sreq->result which 1010 * is what gets returned to the user 1011 */ 1012 if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) { 1013 bool do_print = true; 1014 /* 1015 * if ATA PASS-THROUGH INFORMATION AVAILABLE [0x0, 0x1d] 1016 * skip print since caller wants ATA registers. Only occurs 1017 * on SCSI ATA PASS_THROUGH commands when CK_COND=1 1018 */ 1019 if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d)) 1020 do_print = false; 1021 else if (req->rq_flags & RQF_QUIET) 1022 do_print = false; 1023 if (do_print) 1024 scsi_print_sense(cmd); 1025 result = 0; 1026 /* for passthrough, *blk_statp may be set */ 1027 *blk_statp = BLK_STS_OK; 1028 } 1029 /* 1030 * Another corner case: the SCSI status byte is non-zero but 'good'. 1031 * Example: PRE-FETCH command returns SAM_STAT_CONDITION_MET when 1032 * it is able to fit nominated LBs in its cache (and SAM_STAT_GOOD 1033 * if it can't fit). Treat SAM_STAT_CONDITION_MET and the related 1034 * intermediate statuses (both obsolete in SAM-4) as good. 1035 */ 1036 if ((result & 0xff) && scsi_status_is_good(result)) { 1037 result = 0; 1038 *blk_statp = BLK_STS_OK; 1039 } 1040 return result; 1041} 1042 1043/** 1044 * scsi_io_completion - Completion processing for SCSI commands. 1045 * @cmd: command that is finished. 1046 * @good_bytes: number of processed bytes. 1047 * 1048 * We will finish off the specified number of sectors. If we are done, the 1049 * command block will be released and the queue function will be goosed. If we 1050 * are not done then we have to figure out what to do next: 1051 * 1052 * a) We can call scsi_mq_requeue_cmd(). The request will be 1053 * unprepared and put back on the queue. Then a new command will 1054 * be created for it. This should be used if we made forward 1055 * progress, or if we want to switch from READ(10) to READ(6) for 1056 * example. 1057 * 1058 * b) We can call scsi_io_completion_action(). The request will be 1059 * put back on the queue and retried using the same command as 1060 * before, possibly after a delay. 1061 * 1062 * c) We can call scsi_end_request() with blk_stat other than 1063 * BLK_STS_OK, to fail the remainder of the request. 1064 */ 1065void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) 1066{ 1067 int result = cmd->result; 1068 struct request *req = scsi_cmd_to_rq(cmd); 1069 blk_status_t blk_stat = BLK_STS_OK; 1070 1071 if (unlikely(result)) /* a nz result may or may not be an error */ 1072 result = scsi_io_completion_nz_result(cmd, result, &blk_stat); 1073 1074 /* 1075 * Next deal with any sectors which we were able to correctly 1076 * handle. 1077 */ 1078 SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, cmd, 1079 "%u sectors total, %d bytes done.\n", 1080 blk_rq_sectors(req), good_bytes)); 1081 1082 /* 1083 * Failed, zero length commands always need to drop down 1084 * to retry code. Fast path should return in this block. 1085 */ 1086 if (likely(blk_rq_bytes(req) > 0 || blk_stat == BLK_STS_OK)) { 1087 if (likely(!scsi_end_request(req, blk_stat, good_bytes))) 1088 return; /* no bytes remaining */ 1089 } 1090 1091 /* Kill remainder if no retries. */ 1092 if (unlikely(blk_stat && scsi_noretry_cmd(cmd))) { 1093 if (scsi_end_request(req, blk_stat, blk_rq_bytes(req))) 1094 WARN_ONCE(true, 1095 "Bytes remaining after failed, no-retry command"); 1096 return; 1097 } 1098 1099 /* 1100 * If there had been no error, but we have leftover bytes in the 1101 * request just queue the command up again. 1102 */ 1103 if (likely(result == 0)) 1104 scsi_mq_requeue_cmd(cmd, 0); 1105 else 1106 scsi_io_completion_action(cmd, result); 1107} 1108 1109static inline bool scsi_cmd_needs_dma_drain(struct scsi_device *sdev, 1110 struct request *rq) 1111{ 1112 return sdev->dma_drain_len && blk_rq_is_passthrough(rq) && 1113 !op_is_write(req_op(rq)) && 1114 sdev->host->hostt->dma_need_drain(rq); 1115} 1116 1117/** 1118 * scsi_alloc_sgtables - Allocate and initialize data and integrity scatterlists 1119 * @cmd: SCSI command data structure to initialize. 1120 * 1121 * Initializes @cmd->sdb and also @cmd->prot_sdb if data integrity is enabled 1122 * for @cmd. 1123 * 1124 * Returns: 1125 * * BLK_STS_OK - on success 1126 * * BLK_STS_RESOURCE - if the failure is retryable 1127 * * BLK_STS_IOERR - if the failure is fatal 1128 */ 1129blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd) 1130{ 1131 struct scsi_device *sdev = cmd->device; 1132 struct request *rq = scsi_cmd_to_rq(cmd); 1133 unsigned short nr_segs = blk_rq_nr_phys_segments(rq); 1134 struct scatterlist *last_sg = NULL; 1135 blk_status_t ret; 1136 bool need_drain = scsi_cmd_needs_dma_drain(sdev, rq); 1137 int count; 1138 1139 if (WARN_ON_ONCE(!nr_segs)) 1140 return BLK_STS_IOERR; 1141 1142 /* 1143 * Make sure there is space for the drain. The driver must adjust 1144 * max_hw_segments to be prepared for this. 1145 */ 1146 if (need_drain) 1147 nr_segs++; 1148 1149 /* 1150 * If sg table allocation fails, requeue request later. 1151 */ 1152 if (unlikely(sg_alloc_table_chained(&cmd->sdb.table, nr_segs, 1153 cmd->sdb.table.sgl, SCSI_INLINE_SG_CNT))) 1154 return BLK_STS_RESOURCE; 1155 1156 /* 1157 * Next, walk the list, and fill in the addresses and sizes of 1158 * each segment. 1159 */ 1160 count = __blk_rq_map_sg(rq, cmd->sdb.table.sgl, &last_sg); 1161 1162 if (blk_rq_bytes(rq) & rq->q->limits.dma_pad_mask) { 1163 unsigned int pad_len = 1164 (rq->q->limits.dma_pad_mask & ~blk_rq_bytes(rq)) + 1; 1165 1166 last_sg->length += pad_len; 1167 cmd->extra_len += pad_len; 1168 } 1169 1170 if (need_drain) { 1171 sg_unmark_end(last_sg); 1172 last_sg = sg_next(last_sg); 1173 sg_set_buf(last_sg, sdev->dma_drain_buf, sdev->dma_drain_len); 1174 sg_mark_end(last_sg); 1175 1176 cmd->extra_len += sdev->dma_drain_len; 1177 count++; 1178 } 1179 1180 BUG_ON(count > cmd->sdb.table.nents); 1181 cmd->sdb.table.nents = count; 1182 cmd->sdb.length = blk_rq_payload_bytes(rq); 1183 1184 if (blk_integrity_rq(rq)) { 1185 struct scsi_data_buffer *prot_sdb = cmd->prot_sdb; 1186 1187 if (WARN_ON_ONCE(!prot_sdb)) { 1188 /* 1189 * This can happen if someone (e.g. multipath) 1190 * queues a command to a device on an adapter 1191 * that does not support DIX. 1192 */ 1193 ret = BLK_STS_IOERR; 1194 goto out_free_sgtables; 1195 } 1196 1197 if (sg_alloc_table_chained(&prot_sdb->table, 1198 rq->nr_integrity_segments, 1199 prot_sdb->table.sgl, 1200 SCSI_INLINE_PROT_SG_CNT)) { 1201 ret = BLK_STS_RESOURCE; 1202 goto out_free_sgtables; 1203 } 1204 1205 count = blk_rq_map_integrity_sg(rq, prot_sdb->table.sgl); 1206 cmd->prot_sdb = prot_sdb; 1207 cmd->prot_sdb->table.nents = count; 1208 } 1209 1210 return BLK_STS_OK; 1211out_free_sgtables: 1212 scsi_free_sgtables(cmd); 1213 return ret; 1214} 1215EXPORT_SYMBOL(scsi_alloc_sgtables); 1216 1217/** 1218 * scsi_initialize_rq - initialize struct scsi_cmnd partially 1219 * @rq: Request associated with the SCSI command to be initialized. 1220 * 1221 * This function initializes the members of struct scsi_cmnd that must be 1222 * initialized before request processing starts and that won't be 1223 * reinitialized if a SCSI command is requeued. 1224 */ 1225static void scsi_initialize_rq(struct request *rq) 1226{ 1227 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); 1228 1229 memset(cmd->cmnd, 0, sizeof(cmd->cmnd)); 1230 cmd->cmd_len = MAX_COMMAND_SIZE; 1231 cmd->sense_len = 0; 1232 init_rcu_head(&cmd->rcu); 1233 cmd->jiffies_at_alloc = jiffies; 1234 cmd->retries = 0; 1235} 1236 1237/** 1238 * scsi_alloc_request - allocate a block request and partially 1239 * initialize its &scsi_cmnd 1240 * @q: the device's request queue 1241 * @opf: the request operation code 1242 * @flags: block layer allocation flags 1243 * 1244 * Return: &struct request pointer on success or %NULL on failure 1245 */ 1246struct request *scsi_alloc_request(struct request_queue *q, blk_opf_t opf, 1247 blk_mq_req_flags_t flags) 1248{ 1249 struct request *rq; 1250 1251 rq = blk_mq_alloc_request(q, opf, flags); 1252 if (!IS_ERR(rq)) 1253 scsi_initialize_rq(rq); 1254 return rq; 1255} 1256EXPORT_SYMBOL_GPL(scsi_alloc_request); 1257 1258/* 1259 * Only called when the request isn't completed by SCSI, and not freed by 1260 * SCSI 1261 */ 1262static void scsi_cleanup_rq(struct request *rq) 1263{ 1264 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); 1265 1266 cmd->flags = 0; 1267 1268 if (rq->rq_flags & RQF_DONTPREP) { 1269 scsi_mq_uninit_cmd(cmd); 1270 rq->rq_flags &= ~RQF_DONTPREP; 1271 } 1272} 1273 1274/* Called before a request is prepared. See also scsi_mq_prep_fn(). */ 1275void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd) 1276{ 1277 struct request *rq = scsi_cmd_to_rq(cmd); 1278 1279 if (!blk_rq_is_passthrough(rq) && !(cmd->flags & SCMD_INITIALIZED)) { 1280 cmd->flags |= SCMD_INITIALIZED; 1281 scsi_initialize_rq(rq); 1282 } 1283 1284 cmd->device = dev; 1285 INIT_LIST_HEAD(&cmd->eh_entry); 1286 INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler); 1287} 1288 1289static blk_status_t scsi_setup_scsi_cmnd(struct scsi_device *sdev, 1290 struct request *req) 1291{ 1292 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); 1293 1294 /* 1295 * Passthrough requests may transfer data, in which case they must 1296 * a bio attached to them. Or they might contain a SCSI command 1297 * that does not transfer data, in which case they may optionally 1298 * submit a request without an attached bio. 1299 */ 1300 if (req->bio) { 1301 blk_status_t ret = scsi_alloc_sgtables(cmd); 1302 if (unlikely(ret != BLK_STS_OK)) 1303 return ret; 1304 } else { 1305 BUG_ON(blk_rq_bytes(req)); 1306 1307 memset(&cmd->sdb, 0, sizeof(cmd->sdb)); 1308 } 1309 1310 cmd->transfersize = blk_rq_bytes(req); 1311 return BLK_STS_OK; 1312} 1313 1314static blk_status_t 1315scsi_device_state_check(struct scsi_device *sdev, struct request *req) 1316{ 1317 switch (sdev->sdev_state) { 1318 case SDEV_CREATED: 1319 return BLK_STS_OK; 1320 case SDEV_OFFLINE: 1321 case SDEV_TRANSPORT_OFFLINE: 1322 /* 1323 * If the device is offline we refuse to process any 1324 * commands. The device must be brought online 1325 * before trying any recovery commands. 1326 */ 1327 if (!sdev->offline_already) { 1328 sdev->offline_already = true; 1329 sdev_printk(KERN_ERR, sdev, 1330 "rejecting I/O to offline device\n"); 1331 } 1332 return BLK_STS_IOERR; 1333 case SDEV_DEL: 1334 /* 1335 * If the device is fully deleted, we refuse to 1336 * process any commands as well. 1337 */ 1338 sdev_printk(KERN_ERR, sdev, 1339 "rejecting I/O to dead device\n"); 1340 return BLK_STS_IOERR; 1341 case SDEV_BLOCK: 1342 case SDEV_CREATED_BLOCK: 1343 return BLK_STS_RESOURCE; 1344 case SDEV_QUIESCE: 1345 /* 1346 * If the device is blocked we only accept power management 1347 * commands. 1348 */ 1349 if (req && WARN_ON_ONCE(!(req->rq_flags & RQF_PM))) 1350 return BLK_STS_RESOURCE; 1351 return BLK_STS_OK; 1352 default: 1353 /* 1354 * For any other not fully online state we only allow 1355 * power management commands. 1356 */ 1357 if (req && !(req->rq_flags & RQF_PM)) 1358 return BLK_STS_OFFLINE; 1359 return BLK_STS_OK; 1360 } 1361} 1362 1363/* 1364 * scsi_dev_queue_ready: if we can send requests to sdev, assign one token 1365 * and return the token else return -1. 1366 */ 1367static inline int scsi_dev_queue_ready(struct request_queue *q, 1368 struct scsi_device *sdev) 1369{ 1370 int token; 1371 1372 if (!sdev->budget_map.map) 1373 return INT_MAX; 1374 1375 token = sbitmap_get(&sdev->budget_map); 1376 if (token < 0) 1377 return -1; 1378 1379 if (!atomic_read(&sdev->device_blocked)) 1380 return token; 1381 1382 /* 1383 * Only unblock if no other commands are pending and 1384 * if device_blocked has decreased to zero 1385 */ 1386 if (scsi_device_busy(sdev) > 1 || 1387 atomic_dec_return(&sdev->device_blocked) > 0) { 1388 sbitmap_put(&sdev->budget_map, token); 1389 return -1; 1390 } 1391 1392 SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev, 1393 "unblocking device at zero depth\n")); 1394 1395 return token; 1396} 1397 1398/* 1399 * scsi_target_queue_ready: checks if there we can send commands to target 1400 * @sdev: scsi device on starget to check. 1401 */ 1402static inline int scsi_target_queue_ready(struct Scsi_Host *shost, 1403 struct scsi_device *sdev) 1404{ 1405 struct scsi_target *starget = scsi_target(sdev); 1406 unsigned int busy; 1407 1408 if (starget->single_lun) { 1409 spin_lock_irq(shost->host_lock); 1410 if (starget->starget_sdev_user && 1411 starget->starget_sdev_user != sdev) { 1412 spin_unlock_irq(shost->host_lock); 1413 return 0; 1414 } 1415 starget->starget_sdev_user = sdev; 1416 spin_unlock_irq(shost->host_lock); 1417 } 1418 1419 if (starget->can_queue <= 0) 1420 return 1; 1421 1422 busy = atomic_inc_return(&starget->target_busy) - 1; 1423 if (atomic_read(&starget->target_blocked) > 0) { 1424 if (busy) 1425 goto starved; 1426 1427 /* 1428 * unblock after target_blocked iterates to zero 1429 */ 1430 if (atomic_dec_return(&starget->target_blocked) > 0) 1431 goto out_dec; 1432 1433 SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget, 1434 "unblocking target at zero depth\n")); 1435 } 1436 1437 if (busy >= starget->can_queue) 1438 goto starved; 1439 1440 return 1; 1441 1442starved: 1443 spin_lock_irq(shost->host_lock); 1444 list_move_tail(&sdev->starved_entry, &shost->starved_list); 1445 spin_unlock_irq(shost->host_lock); 1446out_dec: 1447 if (starget->can_queue > 0) 1448 atomic_dec(&starget->target_busy); 1449 return 0; 1450} 1451 1452/* 1453 * scsi_host_queue_ready: if we can send requests to shost, return 1 else 1454 * return 0. We must end up running the queue again whenever 0 is 1455 * returned, else IO can hang. 1456 */ 1457static inline int scsi_host_queue_ready(struct request_queue *q, 1458 struct Scsi_Host *shost, 1459 struct scsi_device *sdev, 1460 struct scsi_cmnd *cmd) 1461{ 1462 if (atomic_read(&shost->host_blocked) > 0) { 1463 if (scsi_host_busy(shost) > 0) 1464 goto starved; 1465 1466 /* 1467 * unblock after host_blocked iterates to zero 1468 */ 1469 if (atomic_dec_return(&shost->host_blocked) > 0) 1470 goto out_dec; 1471 1472 SCSI_LOG_MLQUEUE(3, 1473 shost_printk(KERN_INFO, shost, 1474 "unblocking host at zero depth\n")); 1475 } 1476 1477 if (shost->host_self_blocked) 1478 goto starved; 1479 1480 /* We're OK to process the command, so we can't be starved */ 1481 if (!list_empty(&sdev->starved_entry)) { 1482 spin_lock_irq(shost->host_lock); 1483 if (!list_empty(&sdev->starved_entry)) 1484 list_del_init(&sdev->starved_entry); 1485 spin_unlock_irq(shost->host_lock); 1486 } 1487 1488 __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); 1489 1490 return 1; 1491 1492starved: 1493 spin_lock_irq(shost->host_lock); 1494 if (list_empty(&sdev->starved_entry)) 1495 list_add_tail(&sdev->starved_entry, &shost->starved_list); 1496 spin_unlock_irq(shost->host_lock); 1497out_dec: 1498 scsi_dec_host_busy(shost, cmd); 1499 return 0; 1500} 1501 1502/* 1503 * Busy state exporting function for request stacking drivers. 1504 * 1505 * For efficiency, no lock is taken to check the busy state of 1506 * shost/starget/sdev, since the returned value is not guaranteed and 1507 * may be changed after request stacking drivers call the function, 1508 * regardless of taking lock or not. 1509 * 1510 * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi 1511 * needs to return 'not busy'. Otherwise, request stacking drivers 1512 * may hold requests forever. 1513 */ 1514static bool scsi_mq_lld_busy(struct request_queue *q) 1515{ 1516 struct scsi_device *sdev = q->queuedata; 1517 struct Scsi_Host *shost; 1518 1519 if (blk_queue_dying(q)) 1520 return false; 1521 1522 shost = sdev->host; 1523 1524 /* 1525 * Ignore host/starget busy state. 1526 * Since block layer does not have a concept of fairness across 1527 * multiple queues, congestion of host/starget needs to be handled 1528 * in SCSI layer. 1529 */ 1530 if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev)) 1531 return true; 1532 1533 return false; 1534} 1535 1536/* 1537 * Block layer request completion callback. May be called from interrupt 1538 * context. 1539 */ 1540static void scsi_complete(struct request *rq) 1541{ 1542 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); 1543 enum scsi_disposition disposition; 1544 1545 if (blk_mq_is_reserved_rq(rq)) { 1546 /* Only pass-through requests are supported in this code path. */ 1547 WARN_ON_ONCE(!blk_rq_is_passthrough(scsi_cmd_to_rq(cmd))); 1548 scsi_mq_uninit_cmd(cmd); 1549 __blk_mq_end_request(rq, scsi_result_to_blk_status(cmd->result)); 1550 return; 1551 } 1552 1553 INIT_LIST_HEAD(&cmd->eh_entry); 1554 1555 atomic_inc(&cmd->device->iodone_cnt); 1556 if (cmd->result) 1557 atomic_inc(&cmd->device->ioerr_cnt); 1558 1559 disposition = scsi_decide_disposition(cmd); 1560 if (disposition != SUCCESS && scsi_cmd_runtime_exceeced(cmd)) 1561 disposition = SUCCESS; 1562 1563 scsi_log_completion(cmd, disposition); 1564 1565 switch (disposition) { 1566 case SUCCESS: 1567 scsi_finish_command(cmd); 1568 break; 1569 case NEEDS_RETRY: 1570 scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); 1571 break; 1572 case ADD_TO_MLQUEUE: 1573 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); 1574 break; 1575 default: 1576 scsi_eh_scmd_add(cmd); 1577 break; 1578 } 1579} 1580 1581/** 1582 * scsi_dispatch_cmd - Dispatch a command to the low-level driver. 1583 * @cmd: command block we are dispatching. 1584 * 1585 * Return: nonzero return request was rejected and device's queue needs to be 1586 * plugged. 1587 */ 1588static int scsi_dispatch_cmd(struct scsi_cmnd *cmd) 1589{ 1590 struct Scsi_Host *host = cmd->device->host; 1591 int rtn = 0; 1592 1593 atomic_inc(&cmd->device->iorequest_cnt); 1594 1595 /* check if the device is still usable */ 1596 if (unlikely(cmd->device->sdev_state == SDEV_DEL)) { 1597 /* in SDEV_DEL we error all commands. DID_NO_CONNECT 1598 * returns an immediate error upwards, and signals 1599 * that the device is no longer present */ 1600 cmd->result = DID_NO_CONNECT << 16; 1601 goto done; 1602 } 1603 1604 /* Check to see if the scsi lld made this device blocked. */ 1605 if (unlikely(scsi_device_blocked(cmd->device))) { 1606 /* 1607 * in blocked state, the command is just put back on 1608 * the device queue. The suspend state has already 1609 * blocked the queue so future requests should not 1610 * occur until the device transitions out of the 1611 * suspend state. 1612 */ 1613 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, 1614 "queuecommand : device blocked\n")); 1615 atomic_dec(&cmd->device->iorequest_cnt); 1616 return SCSI_MLQUEUE_DEVICE_BUSY; 1617 } 1618 1619 /* Store the LUN value in cmnd, if needed. */ 1620 if (cmd->device->lun_in_cdb) 1621 cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) | 1622 (cmd->device->lun << 5 & 0xe0); 1623 1624 scsi_log_send(cmd); 1625 1626 /* 1627 * Before we queue this command, check if the command 1628 * length exceeds what the host adapter can handle. 1629 */ 1630 if (cmd->cmd_len > cmd->device->host->max_cmd_len) { 1631 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, 1632 "queuecommand : command too long. " 1633 "cdb_size=%d host->max_cmd_len=%d\n", 1634 cmd->cmd_len, cmd->device->host->max_cmd_len)); 1635 cmd->result = (DID_ABORT << 16); 1636 goto done; 1637 } 1638 1639 if (unlikely(host->shost_state == SHOST_DEL)) { 1640 cmd->result = (DID_NO_CONNECT << 16); 1641 goto done; 1642 1643 } 1644 1645 trace_scsi_dispatch_cmd_start(cmd); 1646 rtn = host->hostt->queuecommand(host, cmd); 1647 if (rtn) { 1648 atomic_dec(&cmd->device->iorequest_cnt); 1649 trace_scsi_dispatch_cmd_error(cmd, rtn); 1650 if (rtn != SCSI_MLQUEUE_DEVICE_BUSY && 1651 rtn != SCSI_MLQUEUE_TARGET_BUSY) 1652 rtn = SCSI_MLQUEUE_HOST_BUSY; 1653 1654 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd, 1655 "queuecommand : request rejected\n")); 1656 } 1657 1658 return rtn; 1659 done: 1660 scsi_done(cmd); 1661 return 0; 1662} 1663 1664/* Size in bytes of the sg-list stored in the scsi-mq command-private data. */ 1665static unsigned int scsi_mq_inline_sgl_size(struct Scsi_Host *shost) 1666{ 1667 return min_t(unsigned int, shost->sg_tablesize, SCSI_INLINE_SG_CNT) * 1668 sizeof(struct scatterlist); 1669} 1670 1671static blk_status_t scsi_prepare_cmd(struct request *req) 1672{ 1673 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); 1674 struct scsi_device *sdev = req->q->queuedata; 1675 struct Scsi_Host *shost = sdev->host; 1676 bool in_flight = test_bit(SCMD_STATE_INFLIGHT, &cmd->state); 1677 struct scatterlist *sg; 1678 1679 scsi_init_command(sdev, cmd); 1680 1681 cmd->eh_eflags = 0; 1682 cmd->prot_type = 0; 1683 cmd->prot_flags = 0; 1684 cmd->submitter = 0; 1685 memset(&cmd->sdb, 0, sizeof(cmd->sdb)); 1686 cmd->underflow = 0; 1687 cmd->transfersize = 0; 1688 cmd->host_scribble = NULL; 1689 cmd->result = 0; 1690 cmd->extra_len = 0; 1691 cmd->state = 0; 1692 if (in_flight) 1693 __set_bit(SCMD_STATE_INFLIGHT, &cmd->state); 1694 1695 cmd->prot_op = SCSI_PROT_NORMAL; 1696 if (blk_rq_bytes(req)) 1697 cmd->sc_data_direction = rq_dma_dir(req); 1698 else 1699 cmd->sc_data_direction = DMA_NONE; 1700 1701 sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size; 1702 cmd->sdb.table.sgl = sg; 1703 1704 if (scsi_host_get_prot(shost)) { 1705 memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer)); 1706 1707 cmd->prot_sdb->table.sgl = 1708 (struct scatterlist *)(cmd->prot_sdb + 1); 1709 } 1710 1711 /* 1712 * Special handling for passthrough commands, which don't go to the ULP 1713 * at all: 1714 */ 1715 if (blk_rq_is_passthrough(req)) 1716 return scsi_setup_scsi_cmnd(sdev, req); 1717 1718 if (sdev->handler && sdev->handler->prep_fn) { 1719 blk_status_t ret = sdev->handler->prep_fn(sdev, req); 1720 1721 if (ret != BLK_STS_OK) 1722 return ret; 1723 } 1724 1725 /* Usually overridden by the ULP */ 1726 cmd->allowed = 0; 1727 memset(cmd->cmnd, 0, sizeof(cmd->cmnd)); 1728 return scsi_cmd_to_driver(cmd)->init_command(cmd); 1729} 1730 1731static void scsi_done_internal(struct scsi_cmnd *cmd, bool complete_directly) 1732{ 1733 struct request *req = scsi_cmd_to_rq(cmd); 1734 1735 switch (cmd->submitter) { 1736 case SUBMITTED_BY_BLOCK_LAYER: 1737 break; 1738 case SUBMITTED_BY_SCSI_ERROR_HANDLER: 1739 return scsi_eh_done(cmd); 1740 case SUBMITTED_BY_SCSI_RESET_IOCTL: 1741 return; 1742 } 1743 1744 if (unlikely(blk_should_fake_timeout(scsi_cmd_to_rq(cmd)->q))) 1745 return; 1746 if (unlikely(test_and_set_bit(SCMD_STATE_COMPLETE, &cmd->state))) 1747 return; 1748 trace_scsi_dispatch_cmd_done(cmd); 1749 1750 if (complete_directly) 1751 blk_mq_complete_request_direct(req, scsi_complete); 1752 else 1753 blk_mq_complete_request(req); 1754} 1755 1756void scsi_done(struct scsi_cmnd *cmd) 1757{ 1758 scsi_done_internal(cmd, false); 1759} 1760EXPORT_SYMBOL(scsi_done); 1761 1762void scsi_done_direct(struct scsi_cmnd *cmd) 1763{ 1764 scsi_done_internal(cmd, true); 1765} 1766EXPORT_SYMBOL(scsi_done_direct); 1767 1768static void scsi_mq_put_budget(struct request_queue *q, int budget_token) 1769{ 1770 struct scsi_device *sdev = q->queuedata; 1771 1772 if (sdev->budget_map.map) 1773 sbitmap_put(&sdev->budget_map, budget_token); 1774} 1775 1776/* 1777 * When to reinvoke queueing after a resource shortage. It's 3 msecs to 1778 * not change behaviour from the previous unplug mechanism, experimentation 1779 * may prove this needs changing. 1780 */ 1781#define SCSI_QUEUE_DELAY 3 1782 1783static int scsi_mq_get_budget(struct request_queue *q) 1784{ 1785 struct scsi_device *sdev = q->queuedata; 1786 int token = scsi_dev_queue_ready(q, sdev); 1787 1788 if (token >= 0) 1789 return token; 1790 1791 atomic_inc(&sdev->restarts); 1792 1793 /* 1794 * Orders atomic_inc(&sdev->restarts) and atomic_read(&sdev->device_busy). 1795 * .restarts must be incremented before .device_busy is read because the 1796 * code in scsi_run_queue_async() depends on the order of these operations. 1797 */ 1798 smp_mb__after_atomic(); 1799 1800 /* 1801 * If all in-flight requests originated from this LUN are completed 1802 * before reading .device_busy, sdev->device_busy will be observed as 1803 * zero, then blk_mq_delay_run_hw_queues() will dispatch this request 1804 * soon. Otherwise, completion of one of these requests will observe 1805 * the .restarts flag, and the request queue will be run for handling 1806 * this request, see scsi_end_request(). 1807 */ 1808 if (unlikely(scsi_device_busy(sdev) == 0 && 1809 !scsi_device_blocked(sdev))) 1810 blk_mq_delay_run_hw_queues(sdev->request_queue, SCSI_QUEUE_DELAY); 1811 return -1; 1812} 1813 1814static void scsi_mq_set_rq_budget_token(struct request *req, int token) 1815{ 1816 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); 1817 1818 cmd->budget_token = token; 1819} 1820 1821static int scsi_mq_get_rq_budget_token(struct request *req) 1822{ 1823 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); 1824 1825 return cmd->budget_token; 1826} 1827 1828static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, 1829 const struct blk_mq_queue_data *bd) 1830{ 1831 struct request *req = bd->rq; 1832 struct request_queue *q = req->q; 1833 struct scsi_device *sdev = q->queuedata; 1834 struct Scsi_Host *shost = sdev->host; 1835 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); 1836 blk_status_t ret; 1837 int reason; 1838 1839 WARN_ON_ONCE(cmd->budget_token < 0); 1840 1841 /* 1842 * Bypass the SCSI device, SCSI target and SCSI host checks for 1843 * reserved commands. 1844 */ 1845 if (!blk_mq_is_reserved_rq(req)) { 1846 /* 1847 * If the device is not in running state we will reject some or 1848 * all commands. 1849 */ 1850 if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { 1851 ret = scsi_device_state_check(sdev, req); 1852 if (ret != BLK_STS_OK) 1853 goto out_put_budget; 1854 } 1855 1856 ret = BLK_STS_RESOURCE; 1857 if (!scsi_target_queue_ready(shost, sdev)) 1858 goto out_put_budget; 1859 if (unlikely(scsi_host_in_recovery(shost))) { 1860 if (cmd->flags & SCMD_FAIL_IF_RECOVERING) 1861 ret = BLK_STS_OFFLINE; 1862 goto out_dec_target_busy; 1863 } 1864 if (!scsi_host_queue_ready(q, shost, sdev, cmd)) 1865 goto out_dec_target_busy; 1866 } 1867 1868 /* 1869 * Only clear the driver-private command data if the LLD does not supply 1870 * a function to initialize that data. 1871 */ 1872 if (shost->hostt->cmd_size && !shost->hostt->init_cmd_priv) 1873 memset(scsi_cmd_priv(cmd), 0, shost->hostt->cmd_size); 1874 1875 if (!(req->rq_flags & RQF_DONTPREP)) { 1876 ret = scsi_prepare_cmd(req); 1877 if (ret != BLK_STS_OK) 1878 goto out_dec_host_busy; 1879 req->rq_flags |= RQF_DONTPREP; 1880 } else { 1881 clear_bit(SCMD_STATE_COMPLETE, &cmd->state); 1882 } 1883 1884 cmd->flags &= SCMD_PRESERVED_FLAGS; 1885 if (sdev->simple_tags) 1886 cmd->flags |= SCMD_TAGGED; 1887 if (bd->last) 1888 cmd->flags |= SCMD_LAST; 1889 1890 scsi_set_resid(cmd, 0); 1891 memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); 1892 cmd->submitter = SUBMITTED_BY_BLOCK_LAYER; 1893 1894 blk_mq_start_request(req); 1895 if (blk_mq_is_reserved_rq(req)) { 1896 reason = shost->hostt->queue_reserved_command(shost, cmd); 1897 if (reason) { 1898 ret = BLK_STS_RESOURCE; 1899 goto out_put_budget; 1900 } 1901 return BLK_STS_OK; 1902 } 1903 reason = scsi_dispatch_cmd(cmd); 1904 if (reason) { 1905 scsi_set_blocked(cmd, reason); 1906 ret = BLK_STS_RESOURCE; 1907 goto out_dec_host_busy; 1908 } 1909 1910 return BLK_STS_OK; 1911 1912out_dec_host_busy: 1913 scsi_dec_host_busy(shost, cmd); 1914out_dec_target_busy: 1915 if (scsi_target(sdev)->can_queue > 0) 1916 atomic_dec(&scsi_target(sdev)->target_busy); 1917out_put_budget: 1918 scsi_mq_put_budget(q, cmd->budget_token); 1919 cmd->budget_token = -1; 1920 switch (ret) { 1921 case BLK_STS_OK: 1922 break; 1923 case BLK_STS_RESOURCE: 1924 if (scsi_device_blocked(sdev)) 1925 ret = BLK_STS_DEV_RESOURCE; 1926 break; 1927 case BLK_STS_AGAIN: 1928 cmd->result = DID_BUS_BUSY << 16; 1929 if (req->rq_flags & RQF_DONTPREP) 1930 scsi_mq_uninit_cmd(cmd); 1931 break; 1932 default: 1933 if (unlikely(!scsi_device_online(sdev))) 1934 cmd->result = DID_NO_CONNECT << 16; 1935 else 1936 cmd->result = DID_ERROR << 16; 1937 /* 1938 * Make sure to release all allocated resources when 1939 * we hit an error, as we will never see this command 1940 * again. 1941 */ 1942 if (req->rq_flags & RQF_DONTPREP) 1943 scsi_mq_uninit_cmd(cmd); 1944 scsi_run_queue_async(sdev); 1945 break; 1946 } 1947 return ret; 1948} 1949 1950static int scsi_mq_init_request(struct blk_mq_tag_set *set, struct request *rq, 1951 unsigned int hctx_idx, unsigned int numa_node) 1952{ 1953 struct Scsi_Host *shost = set->driver_data; 1954 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); 1955 struct scatterlist *sg; 1956 int ret = 0; 1957 1958 cmd->sense_buffer = 1959 kmem_cache_alloc_node(scsi_sense_cache, GFP_KERNEL, numa_node); 1960 if (!cmd->sense_buffer) 1961 return -ENOMEM; 1962 1963 if (scsi_host_get_prot(shost)) { 1964 sg = (void *)cmd + sizeof(struct scsi_cmnd) + 1965 shost->hostt->cmd_size; 1966 cmd->prot_sdb = (void *)sg + scsi_mq_inline_sgl_size(shost); 1967 } 1968 1969 if (shost->hostt->init_cmd_priv) { 1970 ret = shost->hostt->init_cmd_priv(shost, cmd); 1971 if (ret < 0) 1972 kmem_cache_free(scsi_sense_cache, cmd->sense_buffer); 1973 } 1974 1975 return ret; 1976} 1977 1978static void scsi_mq_exit_request(struct blk_mq_tag_set *set, struct request *rq, 1979 unsigned int hctx_idx) 1980{ 1981 struct Scsi_Host *shost = set->driver_data; 1982 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); 1983 1984 if (shost->hostt->exit_cmd_priv) 1985 shost->hostt->exit_cmd_priv(shost, cmd); 1986 kmem_cache_free(scsi_sense_cache, cmd->sense_buffer); 1987} 1988 1989 1990static int scsi_mq_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob) 1991{ 1992 struct Scsi_Host *shost = hctx->driver_data; 1993 1994 if (shost->hostt->mq_poll) 1995 return shost->hostt->mq_poll(shost, hctx->queue_num); 1996 1997 return 0; 1998} 1999 2000static int scsi_init_hctx(struct blk_mq_hw_ctx *hctx, void *data, 2001 unsigned int hctx_idx) 2002{ 2003 struct Scsi_Host *shost = data; 2004 2005 hctx->driver_data = shost; 2006 return 0; 2007} 2008 2009static void scsi_map_queues(struct blk_mq_tag_set *set) 2010{ 2011 struct Scsi_Host *shost = container_of(set, struct Scsi_Host, tag_set); 2012 2013 if (shost->hostt->map_queues) 2014 return shost->hostt->map_queues(shost); 2015 blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]); 2016} 2017 2018void scsi_init_limits(struct Scsi_Host *shost, struct queue_limits *lim) 2019{ 2020 struct device *dev = shost->dma_dev; 2021 2022 memset(lim, 0, sizeof(*lim)); 2023 lim->max_segments = 2024 min_t(unsigned short, shost->sg_tablesize, SG_MAX_SEGMENTS); 2025 2026 if (scsi_host_prot_dma(shost)) { 2027 shost->sg_prot_tablesize = 2028 min_not_zero(shost->sg_prot_tablesize, 2029 (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS); 2030 BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize); 2031 lim->max_integrity_segments = shost->sg_prot_tablesize; 2032 } 2033 2034 lim->max_hw_sectors = shost->max_sectors; 2035 lim->seg_boundary_mask = shost->dma_boundary; 2036 lim->max_segment_size = shost->max_segment_size; 2037 lim->virt_boundary_mask = shost->virt_boundary_mask; 2038 lim->dma_alignment = max_t(unsigned int, 2039 shost->dma_alignment, dma_get_cache_alignment() - 1); 2040 2041 /* 2042 * Propagate the DMA formation properties to the dma-mapping layer as 2043 * a courtesy service to the LLDDs. This needs to check that the buses 2044 * actually support the DMA API first, though. 2045 */ 2046 if (dev->dma_parms) { 2047 dma_set_seg_boundary(dev, shost->dma_boundary); 2048 dma_set_max_seg_size(dev, shost->max_segment_size); 2049 } 2050} 2051EXPORT_SYMBOL_GPL(scsi_init_limits); 2052 2053static const struct blk_mq_ops scsi_mq_ops_no_commit = { 2054 .get_budget = scsi_mq_get_budget, 2055 .put_budget = scsi_mq_put_budget, 2056 .queue_rq = scsi_queue_rq, 2057 .complete = scsi_complete, 2058 .timeout = scsi_timeout, 2059#ifdef CONFIG_BLK_DEBUG_FS 2060 .show_rq = scsi_show_rq, 2061#endif 2062 .init_request = scsi_mq_init_request, 2063 .exit_request = scsi_mq_exit_request, 2064 .cleanup_rq = scsi_cleanup_rq, 2065 .busy = scsi_mq_lld_busy, 2066 .map_queues = scsi_map_queues, 2067 .init_hctx = scsi_init_hctx, 2068 .poll = scsi_mq_poll, 2069 .set_rq_budget_token = scsi_mq_set_rq_budget_token, 2070 .get_rq_budget_token = scsi_mq_get_rq_budget_token, 2071}; 2072 2073 2074static void scsi_commit_rqs(struct blk_mq_hw_ctx *hctx) 2075{ 2076 struct Scsi_Host *shost = hctx->driver_data; 2077 2078 shost->hostt->commit_rqs(shost, hctx->queue_num); 2079} 2080 2081static const struct blk_mq_ops scsi_mq_ops = { 2082 .get_budget = scsi_mq_get_budget, 2083 .put_budget = scsi_mq_put_budget, 2084 .queue_rq = scsi_queue_rq, 2085 .commit_rqs = scsi_commit_rqs, 2086 .complete = scsi_complete, 2087 .timeout = scsi_timeout, 2088#ifdef CONFIG_BLK_DEBUG_FS 2089 .show_rq = scsi_show_rq, 2090#endif 2091 .init_request = scsi_mq_init_request, 2092 .exit_request = scsi_mq_exit_request, 2093 .cleanup_rq = scsi_cleanup_rq, 2094 .busy = scsi_mq_lld_busy, 2095 .map_queues = scsi_map_queues, 2096 .init_hctx = scsi_init_hctx, 2097 .poll = scsi_mq_poll, 2098 .set_rq_budget_token = scsi_mq_set_rq_budget_token, 2099 .get_rq_budget_token = scsi_mq_get_rq_budget_token, 2100}; 2101 2102int scsi_mq_setup_tags(struct Scsi_Host *shost) 2103{ 2104 unsigned int cmd_size, sgl_size; 2105 struct blk_mq_tag_set *tag_set = &shost->tag_set; 2106 2107 sgl_size = max_t(unsigned int, sizeof(struct scatterlist), 2108 scsi_mq_inline_sgl_size(shost)); 2109 cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size + sgl_size; 2110 if (scsi_host_get_prot(shost)) 2111 cmd_size += sizeof(struct scsi_data_buffer) + 2112 sizeof(struct scatterlist) * SCSI_INLINE_PROT_SG_CNT; 2113 2114 memset(tag_set, 0, sizeof(*tag_set)); 2115 if (shost->hostt->commit_rqs) 2116 tag_set->ops = &scsi_mq_ops; 2117 else 2118 tag_set->ops = &scsi_mq_ops_no_commit; 2119 tag_set->nr_hw_queues = shost->nr_hw_queues ? : 1; 2120 tag_set->nr_maps = shost->nr_maps ? : 1; 2121 tag_set->queue_depth = shost->can_queue + shost->nr_reserved_cmds; 2122 tag_set->reserved_tags = shost->nr_reserved_cmds; 2123 tag_set->cmd_size = cmd_size; 2124 tag_set->numa_node = dev_to_node(shost->dma_dev); 2125 if (shost->hostt->tag_alloc_policy_rr) 2126 tag_set->flags |= BLK_MQ_F_TAG_RR; 2127 if (shost->queuecommand_may_block) 2128 tag_set->flags |= BLK_MQ_F_BLOCKING; 2129 tag_set->driver_data = shost; 2130 if (shost->host_tagset) 2131 tag_set->flags |= BLK_MQ_F_TAG_HCTX_SHARED; 2132 2133 return blk_mq_alloc_tag_set(tag_set); 2134} 2135 2136void scsi_mq_free_tags(struct kref *kref) 2137{ 2138 struct Scsi_Host *shost = container_of(kref, typeof(*shost), 2139 tagset_refcnt); 2140 2141 blk_mq_free_tag_set(&shost->tag_set); 2142 complete(&shost->tagset_freed); 2143} 2144 2145/** 2146 * scsi_get_internal_cmd() - Allocate an internal SCSI command. 2147 * @sdev: SCSI device from which to allocate the command 2148 * @data_direction: Data direction for the allocated command 2149 * @flags: request allocation flags, e.g. BLK_MQ_REQ_RESERVED or 2150 * BLK_MQ_REQ_NOWAIT. 2151 * 2152 * Allocates a SCSI command for internal LLDD use. 2153 */ 2154struct scsi_cmnd *scsi_get_internal_cmd(struct scsi_device *sdev, 2155 enum dma_data_direction data_direction, 2156 blk_mq_req_flags_t flags) 2157{ 2158 enum req_op op = data_direction == DMA_TO_DEVICE ? REQ_OP_DRV_OUT : 2159 REQ_OP_DRV_IN; 2160 struct scsi_cmnd *scmd; 2161 struct request *rq; 2162 2163 rq = scsi_alloc_request(sdev->request_queue, op, flags); 2164 if (IS_ERR(rq)) 2165 return NULL; 2166 scmd = blk_mq_rq_to_pdu(rq); 2167 scmd->device = sdev; 2168 2169 return scmd; 2170} 2171EXPORT_SYMBOL_GPL(scsi_get_internal_cmd); 2172 2173/** 2174 * scsi_put_internal_cmd() - Free an internal SCSI command. 2175 * @scmd: SCSI command to be freed 2176 */ 2177void scsi_put_internal_cmd(struct scsi_cmnd *scmd) 2178{ 2179 blk_mq_free_request(blk_mq_rq_from_pdu(scmd)); 2180} 2181EXPORT_SYMBOL_GPL(scsi_put_internal_cmd); 2182 2183/** 2184 * scsi_device_from_queue - return sdev associated with a request_queue 2185 * @q: The request queue to return the sdev from 2186 * 2187 * Return the sdev associated with a request queue or NULL if the 2188 * request_queue does not reference a SCSI device. 2189 */ 2190struct scsi_device *scsi_device_from_queue(struct request_queue *q) 2191{ 2192 struct scsi_device *sdev = NULL; 2193 2194 if (q->mq_ops == &scsi_mq_ops_no_commit || 2195 q->mq_ops == &scsi_mq_ops) 2196 sdev = q->queuedata; 2197 if (!sdev || !get_device(&sdev->sdev_gendev)) 2198 sdev = NULL; 2199 2200 return sdev; 2201} 2202/* 2203 * pktcdvd should have been integrated into the SCSI layers, but for historical 2204 * reasons like the old IDE driver it isn't. This export allows it to safely 2205 * probe if a given device is a SCSI one and only attach to that. 2206 */ 2207#ifdef CONFIG_CDROM_PKTCDVD_MODULE 2208EXPORT_SYMBOL_GPL(scsi_device_from_queue); 2209#endif 2210 2211/** 2212 * scsi_block_requests - Utility function used by low-level drivers to prevent 2213 * further commands from being queued to the device. 2214 * @shost: host in question 2215 * 2216 * There is no timer nor any other means by which the requests get unblocked 2217 * other than the low-level driver calling scsi_unblock_requests(). 2218 */ 2219void scsi_block_requests(struct Scsi_Host *shost) 2220{ 2221 shost->host_self_blocked = 1; 2222} 2223EXPORT_SYMBOL(scsi_block_requests); 2224 2225/** 2226 * scsi_unblock_requests - Utility function used by low-level drivers to allow 2227 * further commands to be queued to the device. 2228 * @shost: host in question 2229 * 2230 * There is no timer nor any other means by which the requests get unblocked 2231 * other than the low-level driver calling scsi_unblock_requests(). This is done 2232 * as an API function so that changes to the internals of the scsi mid-layer 2233 * won't require wholesale changes to drivers that use this feature. 2234 */ 2235void scsi_unblock_requests(struct Scsi_Host *shost) 2236{ 2237 shost->host_self_blocked = 0; 2238 scsi_run_host_queues(shost); 2239} 2240EXPORT_SYMBOL(scsi_unblock_requests); 2241 2242void scsi_exit_queue(void) 2243{ 2244 kmem_cache_destroy(scsi_sense_cache); 2245} 2246 2247/** 2248 * scsi_mode_select - issue a mode select 2249 * @sdev: SCSI device to be queried 2250 * @pf: Page format bit (1 == standard, 0 == vendor specific) 2251 * @sp: Save page bit (0 == don't save, 1 == save) 2252 * @buffer: request buffer (may not be smaller than eight bytes) 2253 * @len: length of request buffer. 2254 * @timeout: command timeout 2255 * @retries: number of retries before failing 2256 * @data: returns a structure abstracting the mode header data 2257 * @sshdr: place to put sense data (or NULL if no sense to be collected). 2258 * must be SCSI_SENSE_BUFFERSIZE big. 2259 * 2260 * Returns zero if successful; negative error number or scsi 2261 * status on error 2262 * 2263 */ 2264int scsi_mode_select(struct scsi_device *sdev, int pf, int sp, 2265 unsigned char *buffer, int len, int timeout, int retries, 2266 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) 2267{ 2268 unsigned char cmd[10]; 2269 unsigned char *real_buffer; 2270 const struct scsi_exec_args exec_args = { 2271 .sshdr = sshdr, 2272 }; 2273 int ret; 2274 2275 memset(cmd, 0, sizeof(cmd)); 2276 cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); 2277 2278 /* 2279 * Use MODE SELECT(10) if the device asked for it or if the mode page 2280 * and the mode select header cannot fit within the maximumm 255 bytes 2281 * of the MODE SELECT(6) command. 2282 */ 2283 if (sdev->use_10_for_ms || 2284 len + 4 > 255 || 2285 data->block_descriptor_length > 255) { 2286 if (len > 65535 - 8) 2287 return -EINVAL; 2288 real_buffer = kmalloc(8 + len, GFP_KERNEL); 2289 if (!real_buffer) 2290 return -ENOMEM; 2291 memcpy(real_buffer + 8, buffer, len); 2292 len += 8; 2293 real_buffer[0] = 0; 2294 real_buffer[1] = 0; 2295 real_buffer[2] = data->medium_type; 2296 real_buffer[3] = data->device_specific; 2297 real_buffer[4] = data->longlba ? 0x01 : 0; 2298 real_buffer[5] = 0; 2299 put_unaligned_be16(data->block_descriptor_length, 2300 &real_buffer[6]); 2301 2302 cmd[0] = MODE_SELECT_10; 2303 put_unaligned_be16(len, &cmd[7]); 2304 } else { 2305 if (data->longlba) 2306 return -EINVAL; 2307 2308 real_buffer = kmalloc(4 + len, GFP_KERNEL); 2309 if (!real_buffer) 2310 return -ENOMEM; 2311 memcpy(real_buffer + 4, buffer, len); 2312 len += 4; 2313 real_buffer[0] = 0; 2314 real_buffer[1] = data->medium_type; 2315 real_buffer[2] = data->device_specific; 2316 real_buffer[3] = data->block_descriptor_length; 2317 2318 cmd[0] = MODE_SELECT; 2319 cmd[4] = len; 2320 } 2321 2322 ret = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_OUT, real_buffer, len, 2323 timeout, retries, &exec_args); 2324 kfree(real_buffer); 2325 return ret; 2326} 2327EXPORT_SYMBOL_GPL(scsi_mode_select); 2328 2329/** 2330 * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary. 2331 * @sdev: SCSI device to be queried 2332 * @dbd: set to prevent mode sense from returning block descriptors 2333 * @modepage: mode page being requested 2334 * @subpage: sub-page of the mode page being requested 2335 * @buffer: request buffer (may not be smaller than eight bytes) 2336 * @len: length of request buffer. 2337 * @timeout: command timeout 2338 * @retries: number of retries before failing 2339 * @data: returns a structure abstracting the mode header data 2340 * @sshdr: place to put sense data (or NULL if no sense to be collected). 2341 * must be SCSI_SENSE_BUFFERSIZE big. 2342 * 2343 * Returns zero if successful, or a negative error number on failure 2344 */ 2345int 2346scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, int subpage, 2347 unsigned char *buffer, int len, int timeout, int retries, 2348 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) 2349{ 2350 unsigned char cmd[12]; 2351 int use_10_for_ms; 2352 int header_length; 2353 int result; 2354 struct scsi_sense_hdr my_sshdr; 2355 struct scsi_failure failure_defs[] = { 2356 { 2357 .sense = UNIT_ATTENTION, 2358 .asc = SCMD_FAILURE_ASC_ANY, 2359 .ascq = SCMD_FAILURE_ASCQ_ANY, 2360 .allowed = retries, 2361 .result = SAM_STAT_CHECK_CONDITION, 2362 }, 2363 {} 2364 }; 2365 struct scsi_failures failures = { 2366 .failure_definitions = failure_defs, 2367 }; 2368 const struct scsi_exec_args exec_args = { 2369 /* caller might not be interested in sense, but we need it */ 2370 .sshdr = sshdr ? : &my_sshdr, 2371 .failures = &failures, 2372 }; 2373 2374 memset(data, 0, sizeof(*data)); 2375 memset(&cmd[0], 0, 12); 2376 2377 dbd = sdev->set_dbd_for_ms ? 8 : dbd; 2378 cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */ 2379 cmd[2] = modepage; 2380 cmd[3] = subpage; 2381 2382 sshdr = exec_args.sshdr; 2383 2384 retry: 2385 use_10_for_ms = sdev->use_10_for_ms || len > 255; 2386 2387 if (use_10_for_ms) { 2388 if (len < 8 || len > 65535) 2389 return -EINVAL; 2390 2391 cmd[0] = MODE_SENSE_10; 2392 put_unaligned_be16(len, &cmd[7]); 2393 header_length = 8; 2394 } else { 2395 if (len < 4) 2396 return -EINVAL; 2397 2398 cmd[0] = MODE_SENSE; 2399 cmd[4] = len; 2400 header_length = 4; 2401 } 2402 2403 memset(buffer, 0, len); 2404 2405 result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, buffer, len, 2406 timeout, retries, &exec_args); 2407 if (result < 0) 2408 return result; 2409 2410 /* This code looks awful: what it's doing is making sure an 2411 * ILLEGAL REQUEST sense return identifies the actual command 2412 * byte as the problem. MODE_SENSE commands can return 2413 * ILLEGAL REQUEST if the code page isn't supported */ 2414 2415 if (!scsi_status_is_good(result)) { 2416 if (scsi_sense_valid(sshdr)) { 2417 if ((sshdr->sense_key == ILLEGAL_REQUEST) && 2418 (sshdr->asc == 0x20) && (sshdr->ascq == 0)) { 2419 /* 2420 * Invalid command operation code: retry using 2421 * MODE SENSE(6) if this was a MODE SENSE(10) 2422 * request, except if the request mode page is 2423 * too large for MODE SENSE single byte 2424 * allocation length field. 2425 */ 2426 if (use_10_for_ms) { 2427 if (len > 255) 2428 return -EIO; 2429 sdev->use_10_for_ms = 0; 2430 goto retry; 2431 } 2432 } 2433 } 2434 return -EIO; 2435 } 2436 if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && 2437 (modepage == 6 || modepage == 8))) { 2438 /* Initio breakage? */ 2439 header_length = 0; 2440 data->length = 13; 2441 data->medium_type = 0; 2442 data->device_specific = 0; 2443 data->longlba = 0; 2444 data->block_descriptor_length = 0; 2445 } else if (use_10_for_ms) { 2446 data->length = get_unaligned_be16(&buffer[0]) + 2; 2447 data->medium_type = buffer[2]; 2448 data->device_specific = buffer[3]; 2449 data->longlba = buffer[4] & 0x01; 2450 data->block_descriptor_length = get_unaligned_be16(&buffer[6]); 2451 } else { 2452 data->length = buffer[0] + 1; 2453 data->medium_type = buffer[1]; 2454 data->device_specific = buffer[2]; 2455 data->block_descriptor_length = buffer[3]; 2456 } 2457 data->header_length = header_length; 2458 2459 return 0; 2460} 2461EXPORT_SYMBOL(scsi_mode_sense); 2462 2463/** 2464 * scsi_test_unit_ready - test if unit is ready 2465 * @sdev: scsi device to change the state of. 2466 * @timeout: command timeout 2467 * @retries: number of retries before failing 2468 * @sshdr: outpout pointer for decoded sense information. 2469 * 2470 * Returns zero if successful or an error if TUR failed. For 2471 * removable media, UNIT_ATTENTION sets ->changed flag. 2472 **/ 2473int 2474scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, 2475 struct scsi_sense_hdr *sshdr) 2476{ 2477 char cmd[] = { 2478 TEST_UNIT_READY, 0, 0, 0, 0, 0, 2479 }; 2480 const struct scsi_exec_args exec_args = { 2481 .sshdr = sshdr, 2482 }; 2483 int result; 2484 2485 /* try to eat the UNIT_ATTENTION if there are enough retries */ 2486 do { 2487 result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, NULL, 0, 2488 timeout, 1, &exec_args); 2489 if (sdev->removable && result > 0 && scsi_sense_valid(sshdr) && 2490 sshdr->sense_key == UNIT_ATTENTION) 2491 sdev->changed = 1; 2492 } while (result > 0 && scsi_sense_valid(sshdr) && 2493 sshdr->sense_key == UNIT_ATTENTION && --retries); 2494 2495 return result; 2496} 2497EXPORT_SYMBOL(scsi_test_unit_ready); 2498 2499/** 2500 * scsi_device_set_state - Take the given device through the device state model. 2501 * @sdev: scsi device to change the state of. 2502 * @state: state to change to. 2503 * 2504 * Returns zero if successful or an error if the requested 2505 * transition is illegal. 2506 */ 2507int 2508scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) 2509{ 2510 enum scsi_device_state oldstate = sdev->sdev_state; 2511 2512 if (state == oldstate) 2513 return 0; 2514 2515 switch (state) { 2516 case SDEV_CREATED: 2517 switch (oldstate) { 2518 case SDEV_CREATED_BLOCK: 2519 break; 2520 default: 2521 goto illegal; 2522 } 2523 break; 2524 2525 case SDEV_RUNNING: 2526 switch (oldstate) { 2527 case SDEV_CREATED: 2528 case SDEV_OFFLINE: 2529 case SDEV_TRANSPORT_OFFLINE: 2530 case SDEV_QUIESCE: 2531 case SDEV_BLOCK: 2532 break; 2533 default: 2534 goto illegal; 2535 } 2536 break; 2537 2538 case SDEV_QUIESCE: 2539 switch (oldstate) { 2540 case SDEV_RUNNING: 2541 case SDEV_OFFLINE: 2542 case SDEV_TRANSPORT_OFFLINE: 2543 break; 2544 default: 2545 goto illegal; 2546 } 2547 break; 2548 2549 case SDEV_OFFLINE: 2550 case SDEV_TRANSPORT_OFFLINE: 2551 switch (oldstate) { 2552 case SDEV_CREATED: 2553 case SDEV_RUNNING: 2554 case SDEV_QUIESCE: 2555 case SDEV_BLOCK: 2556 break; 2557 default: 2558 goto illegal; 2559 } 2560 break; 2561 2562 case SDEV_BLOCK: 2563 switch (oldstate) { 2564 case SDEV_RUNNING: 2565 case SDEV_CREATED_BLOCK: 2566 case SDEV_QUIESCE: 2567 case SDEV_OFFLINE: 2568 break; 2569 default: 2570 goto illegal; 2571 } 2572 break; 2573 2574 case SDEV_CREATED_BLOCK: 2575 switch (oldstate) { 2576 case SDEV_CREATED: 2577 break; 2578 default: 2579 goto illegal; 2580 } 2581 break; 2582 2583 case SDEV_CANCEL: 2584 switch (oldstate) { 2585 case SDEV_CREATED: 2586 case SDEV_RUNNING: 2587 case SDEV_QUIESCE: 2588 case SDEV_OFFLINE: 2589 case SDEV_TRANSPORT_OFFLINE: 2590 break; 2591 default: 2592 goto illegal; 2593 } 2594 break; 2595 2596 case SDEV_DEL: 2597 switch (oldstate) { 2598 case SDEV_CREATED: 2599 case SDEV_RUNNING: 2600 case SDEV_OFFLINE: 2601 case SDEV_TRANSPORT_OFFLINE: 2602 case SDEV_CANCEL: 2603 case SDEV_BLOCK: 2604 case SDEV_CREATED_BLOCK: 2605 break; 2606 default: 2607 goto illegal; 2608 } 2609 break; 2610 2611 } 2612 sdev->offline_already = false; 2613 sdev->sdev_state = state; 2614 return 0; 2615 2616 illegal: 2617 SCSI_LOG_ERROR_RECOVERY(1, 2618 sdev_printk(KERN_ERR, sdev, 2619 "Illegal state transition %s->%s", 2620 scsi_device_state_name(oldstate), 2621 scsi_device_state_name(state)) 2622 ); 2623 return -EINVAL; 2624} 2625EXPORT_SYMBOL(scsi_device_set_state); 2626 2627/** 2628 * scsi_evt_emit - emit a single SCSI device uevent 2629 * @sdev: associated SCSI device 2630 * @evt: event to emit 2631 * 2632 * Send a single uevent (scsi_event) to the associated scsi_device. 2633 */ 2634static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) 2635{ 2636 int idx = 0; 2637 char *envp[3]; 2638 2639 switch (evt->evt_type) { 2640 case SDEV_EVT_MEDIA_CHANGE: 2641 envp[idx++] = "SDEV_MEDIA_CHANGE=1"; 2642 break; 2643 case SDEV_EVT_INQUIRY_CHANGE_REPORTED: 2644 scsi_rescan_device(sdev); 2645 envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED"; 2646 break; 2647 case SDEV_EVT_CAPACITY_CHANGE_REPORTED: 2648 envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED"; 2649 break; 2650 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: 2651 envp[idx++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED"; 2652 break; 2653 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: 2654 envp[idx++] = "SDEV_UA=MODE_PARAMETERS_CHANGED"; 2655 break; 2656 case SDEV_EVT_LUN_CHANGE_REPORTED: 2657 envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED"; 2658 break; 2659 case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED: 2660 envp[idx++] = "SDEV_UA=ASYMMETRIC_ACCESS_STATE_CHANGED"; 2661 break; 2662 case SDEV_EVT_POWER_ON_RESET_OCCURRED: 2663 envp[idx++] = "SDEV_UA=POWER_ON_RESET_OCCURRED"; 2664 break; 2665 default: 2666 /* do nothing */ 2667 break; 2668 } 2669 2670 envp[idx++] = NULL; 2671 2672 kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); 2673} 2674 2675/** 2676 * scsi_evt_thread - send a uevent for each scsi event 2677 * @work: work struct for scsi_device 2678 * 2679 * Dispatch queued events to their associated scsi_device kobjects 2680 * as uevents. 2681 */ 2682void scsi_evt_thread(struct work_struct *work) 2683{ 2684 struct scsi_device *sdev; 2685 enum scsi_device_event evt_type; 2686 LIST_HEAD(event_list); 2687 2688 sdev = container_of(work, struct scsi_device, event_work); 2689 2690 for (evt_type = SDEV_EVT_FIRST; evt_type <= SDEV_EVT_LAST; evt_type++) 2691 if (test_and_clear_bit(evt_type, sdev->pending_events)) 2692 sdev_evt_send_simple(sdev, evt_type, GFP_KERNEL); 2693 2694 while (1) { 2695 struct scsi_event *evt; 2696 struct list_head *this, *tmp; 2697 unsigned long flags; 2698 2699 spin_lock_irqsave(&sdev->list_lock, flags); 2700 list_splice_init(&sdev->event_list, &event_list); 2701 spin_unlock_irqrestore(&sdev->list_lock, flags); 2702 2703 if (list_empty(&event_list)) 2704 break; 2705 2706 list_for_each_safe(this, tmp, &event_list) { 2707 evt = list_entry(this, struct scsi_event, node); 2708 list_del(&evt->node); 2709 scsi_evt_emit(sdev, evt); 2710 kfree(evt); 2711 } 2712 } 2713} 2714 2715/** 2716 * sdev_evt_send - send asserted event to uevent thread 2717 * @sdev: scsi_device event occurred on 2718 * @evt: event to send 2719 * 2720 * Assert scsi device event asynchronously. 2721 */ 2722void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) 2723{ 2724 unsigned long flags; 2725 2726#if 0 2727 /* FIXME: currently this check eliminates all media change events 2728 * for polled devices. Need to update to discriminate between AN 2729 * and polled events */ 2730 if (!test_bit(evt->evt_type, sdev->supported_events)) { 2731 kfree(evt); 2732 return; 2733 } 2734#endif 2735 2736 spin_lock_irqsave(&sdev->list_lock, flags); 2737 list_add_tail(&evt->node, &sdev->event_list); 2738 schedule_work(&sdev->event_work); 2739 spin_unlock_irqrestore(&sdev->list_lock, flags); 2740} 2741EXPORT_SYMBOL_GPL(sdev_evt_send); 2742 2743/** 2744 * sdev_evt_alloc - allocate a new scsi event 2745 * @evt_type: type of event to allocate 2746 * @gfpflags: GFP flags for allocation 2747 * 2748 * Allocates and returns a new scsi_event. 2749 */ 2750struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, 2751 gfp_t gfpflags) 2752{ 2753 struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); 2754 if (!evt) 2755 return NULL; 2756 2757 evt->evt_type = evt_type; 2758 INIT_LIST_HEAD(&evt->node); 2759 2760 /* evt_type-specific initialization, if any */ 2761 switch (evt_type) { 2762 case SDEV_EVT_MEDIA_CHANGE: 2763 case SDEV_EVT_INQUIRY_CHANGE_REPORTED: 2764 case SDEV_EVT_CAPACITY_CHANGE_REPORTED: 2765 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: 2766 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: 2767 case SDEV_EVT_LUN_CHANGE_REPORTED: 2768 case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED: 2769 case SDEV_EVT_POWER_ON_RESET_OCCURRED: 2770 default: 2771 /* do nothing */ 2772 break; 2773 } 2774 2775 return evt; 2776} 2777EXPORT_SYMBOL_GPL(sdev_evt_alloc); 2778 2779/** 2780 * sdev_evt_send_simple - send asserted event to uevent thread 2781 * @sdev: scsi_device event occurred on 2782 * @evt_type: type of event to send 2783 * @gfpflags: GFP flags for allocation 2784 * 2785 * Assert scsi device event asynchronously, given an event type. 2786 */ 2787void sdev_evt_send_simple(struct scsi_device *sdev, 2788 enum scsi_device_event evt_type, gfp_t gfpflags) 2789{ 2790 struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); 2791 if (!evt) { 2792 sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", 2793 evt_type); 2794 return; 2795 } 2796 2797 sdev_evt_send(sdev, evt); 2798} 2799EXPORT_SYMBOL_GPL(sdev_evt_send_simple); 2800 2801/** 2802 * scsi_device_quiesce - Block all commands except power management. 2803 * @sdev: scsi device to quiesce. 2804 * 2805 * This works by trying to transition to the SDEV_QUIESCE state 2806 * (which must be a legal transition). When the device is in this 2807 * state, only power management requests will be accepted, all others will 2808 * be deferred. 2809 * 2810 * Must be called with user context, may sleep. 2811 * 2812 * Returns zero if successful or an error if not. 2813 */ 2814int 2815scsi_device_quiesce(struct scsi_device *sdev) 2816{ 2817 struct request_queue *q = sdev->request_queue; 2818 unsigned int memflags; 2819 int err; 2820 2821 /* 2822 * It is allowed to call scsi_device_quiesce() multiple times from 2823 * the same context but concurrent scsi_device_quiesce() calls are 2824 * not allowed. 2825 */ 2826 WARN_ON_ONCE(sdev->quiesced_by && sdev->quiesced_by != current); 2827 2828 if (sdev->quiesced_by == current) 2829 return 0; 2830 2831 blk_set_pm_only(q); 2832 2833 memflags = blk_mq_freeze_queue(q); 2834 /* 2835 * Ensure that the effect of blk_set_pm_only() will be visible 2836 * for percpu_ref_tryget() callers that occur after the queue 2837 * unfreeze even if the queue was already frozen before this function 2838 * was called. See also https://lwn.net/Articles/573497/. 2839 */ 2840 synchronize_rcu(); 2841 blk_mq_unfreeze_queue(q, memflags); 2842 2843 mutex_lock(&sdev->state_mutex); 2844 err = scsi_device_set_state(sdev, SDEV_QUIESCE); 2845 if (err == 0) 2846 sdev->quiesced_by = current; 2847 else 2848 blk_clear_pm_only(q); 2849 mutex_unlock(&sdev->state_mutex); 2850 2851 return err; 2852} 2853EXPORT_SYMBOL(scsi_device_quiesce); 2854 2855/** 2856 * scsi_device_resume - Restart user issued commands to a quiesced device. 2857 * @sdev: scsi device to resume. 2858 * 2859 * Moves the device from quiesced back to running and restarts the 2860 * queues. 2861 * 2862 * Must be called with user context, may sleep. 2863 */ 2864void scsi_device_resume(struct scsi_device *sdev) 2865{ 2866 /* check if the device state was mutated prior to resume, and if 2867 * so assume the state is being managed elsewhere (for example 2868 * device deleted during suspend) 2869 */ 2870 mutex_lock(&sdev->state_mutex); 2871 if (sdev->sdev_state == SDEV_QUIESCE) 2872 scsi_device_set_state(sdev, SDEV_RUNNING); 2873 if (sdev->quiesced_by) { 2874 sdev->quiesced_by = NULL; 2875 blk_clear_pm_only(sdev->request_queue); 2876 } 2877 mutex_unlock(&sdev->state_mutex); 2878} 2879EXPORT_SYMBOL(scsi_device_resume); 2880 2881static void 2882device_quiesce_fn(struct scsi_device *sdev, void *data) 2883{ 2884 scsi_device_quiesce(sdev); 2885} 2886 2887void 2888scsi_target_quiesce(struct scsi_target *starget) 2889{ 2890 starget_for_each_device(starget, NULL, device_quiesce_fn); 2891} 2892EXPORT_SYMBOL(scsi_target_quiesce); 2893 2894static void 2895device_resume_fn(struct scsi_device *sdev, void *data) 2896{ 2897 scsi_device_resume(sdev); 2898} 2899 2900void 2901scsi_target_resume(struct scsi_target *starget) 2902{ 2903 starget_for_each_device(starget, NULL, device_resume_fn); 2904} 2905EXPORT_SYMBOL(scsi_target_resume); 2906 2907static int __scsi_internal_device_block_nowait(struct scsi_device *sdev) 2908{ 2909 if (scsi_device_set_state(sdev, SDEV_BLOCK)) 2910 return scsi_device_set_state(sdev, SDEV_CREATED_BLOCK); 2911 2912 return 0; 2913} 2914 2915void scsi_start_queue(struct scsi_device *sdev) 2916{ 2917 if (cmpxchg(&sdev->queue_stopped, 1, 0)) 2918 blk_mq_unquiesce_queue(sdev->request_queue); 2919} 2920 2921static void scsi_stop_queue(struct scsi_device *sdev) 2922{ 2923 /* 2924 * The atomic variable of ->queue_stopped covers that 2925 * blk_mq_quiesce_queue* is balanced with blk_mq_unquiesce_queue. 2926 * 2927 * The caller needs to wait until quiesce is done. 2928 */ 2929 if (!cmpxchg(&sdev->queue_stopped, 0, 1)) 2930 blk_mq_quiesce_queue_nowait(sdev->request_queue); 2931} 2932 2933/** 2934 * scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state 2935 * @sdev: device to block 2936 * 2937 * Pause SCSI command processing on the specified device. Does not sleep. 2938 * 2939 * Returns zero if successful or a negative error code upon failure. 2940 * 2941 * Notes: 2942 * This routine transitions the device to the SDEV_BLOCK state (which must be 2943 * a legal transition). When the device is in this state, command processing 2944 * is paused until the device leaves the SDEV_BLOCK state. See also 2945 * scsi_internal_device_unblock_nowait(). 2946 */ 2947int scsi_internal_device_block_nowait(struct scsi_device *sdev) 2948{ 2949 int ret = __scsi_internal_device_block_nowait(sdev); 2950 2951 /* 2952 * The device has transitioned to SDEV_BLOCK. Stop the 2953 * block layer from calling the midlayer with this device's 2954 * request queue. 2955 */ 2956 if (!ret) 2957 scsi_stop_queue(sdev); 2958 return ret; 2959} 2960EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait); 2961 2962/** 2963 * scsi_device_block - try to transition to the SDEV_BLOCK state 2964 * @sdev: device to block 2965 * @data: dummy argument, ignored 2966 * 2967 * Pause SCSI command processing on the specified device. Callers must wait 2968 * until all ongoing scsi_queue_rq() calls have finished after this function 2969 * returns. 2970 * 2971 * Note: 2972 * This routine transitions the device to the SDEV_BLOCK state (which must be 2973 * a legal transition). When the device is in this state, command processing 2974 * is paused until the device leaves the SDEV_BLOCK state. See also 2975 * scsi_internal_device_unblock(). 2976 */ 2977static void scsi_device_block(struct scsi_device *sdev, void *data) 2978{ 2979 int err; 2980 enum scsi_device_state state; 2981 2982 mutex_lock(&sdev->state_mutex); 2983 err = __scsi_internal_device_block_nowait(sdev); 2984 state = sdev->sdev_state; 2985 if (err == 0) 2986 /* 2987 * scsi_stop_queue() must be called with the state_mutex 2988 * held. Otherwise a simultaneous scsi_start_queue() call 2989 * might unquiesce the queue before we quiesce it. 2990 */ 2991 scsi_stop_queue(sdev); 2992 2993 mutex_unlock(&sdev->state_mutex); 2994 2995 WARN_ONCE(err, "%s: failed to block %s in state %d\n", 2996 __func__, dev_name(&sdev->sdev_gendev), state); 2997} 2998 2999/** 3000 * scsi_internal_device_unblock_nowait - resume a device after a block request 3001 * @sdev: device to resume 3002 * @new_state: state to set the device to after unblocking 3003 * 3004 * Restart the device queue for a previously suspended SCSI device. Does not 3005 * sleep. 3006 * 3007 * Returns zero if successful or a negative error code upon failure. 3008 * 3009 * Notes: 3010 * This routine transitions the device to the SDEV_RUNNING state or to one of 3011 * the offline states (which must be a legal transition) allowing the midlayer 3012 * to goose the queue for this device. 3013 */ 3014int scsi_internal_device_unblock_nowait(struct scsi_device *sdev, 3015 enum scsi_device_state new_state) 3016{ 3017 switch (new_state) { 3018 case SDEV_RUNNING: 3019 case SDEV_TRANSPORT_OFFLINE: 3020 break; 3021 default: 3022 return -EINVAL; 3023 } 3024 3025 /* 3026 * Try to transition the scsi device to SDEV_RUNNING or one of the 3027 * offlined states and goose the device queue if successful. 3028 */ 3029 switch (sdev->sdev_state) { 3030 case SDEV_BLOCK: 3031 case SDEV_TRANSPORT_OFFLINE: 3032 sdev->sdev_state = new_state; 3033 break; 3034 case SDEV_CREATED_BLOCK: 3035 if (new_state == SDEV_TRANSPORT_OFFLINE || 3036 new_state == SDEV_OFFLINE) 3037 sdev->sdev_state = new_state; 3038 else 3039 sdev->sdev_state = SDEV_CREATED; 3040 break; 3041 case SDEV_CANCEL: 3042 case SDEV_OFFLINE: 3043 break; 3044 default: 3045 return -EINVAL; 3046 } 3047 scsi_start_queue(sdev); 3048 3049 return 0; 3050} 3051EXPORT_SYMBOL_GPL(scsi_internal_device_unblock_nowait); 3052 3053/** 3054 * scsi_internal_device_unblock - resume a device after a block request 3055 * @sdev: device to resume 3056 * @new_state: state to set the device to after unblocking 3057 * 3058 * Restart the device queue for a previously suspended SCSI device. May sleep. 3059 * 3060 * Returns zero if successful or a negative error code upon failure. 3061 * 3062 * Notes: 3063 * This routine transitions the device to the SDEV_RUNNING state or to one of 3064 * the offline states (which must be a legal transition) allowing the midlayer 3065 * to goose the queue for this device. 3066 */ 3067static int scsi_internal_device_unblock(struct scsi_device *sdev, 3068 enum scsi_device_state new_state) 3069{ 3070 int ret; 3071 3072 mutex_lock(&sdev->state_mutex); 3073 ret = scsi_internal_device_unblock_nowait(sdev, new_state); 3074 mutex_unlock(&sdev->state_mutex); 3075 3076 return ret; 3077} 3078 3079static int 3080target_block(struct device *dev, void *data) 3081{ 3082 if (scsi_is_target_device(dev)) 3083 starget_for_each_device(to_scsi_target(dev), NULL, 3084 scsi_device_block); 3085 return 0; 3086} 3087 3088/** 3089 * scsi_block_targets - transition all SCSI child devices to SDEV_BLOCK state 3090 * @dev: a parent device of one or more scsi_target devices 3091 * @shost: the Scsi_Host to which this device belongs 3092 * 3093 * Iterate over all children of @dev, which should be scsi_target devices, 3094 * and switch all subordinate scsi devices to SDEV_BLOCK state. Wait for 3095 * ongoing scsi_queue_rq() calls to finish. May sleep. 3096 * 3097 * Note: 3098 * @dev must not itself be a scsi_target device. 3099 */ 3100void 3101scsi_block_targets(struct Scsi_Host *shost, struct device *dev) 3102{ 3103 WARN_ON_ONCE(scsi_is_target_device(dev)); 3104 device_for_each_child(dev, NULL, target_block); 3105 blk_mq_wait_quiesce_done(&shost->tag_set); 3106} 3107EXPORT_SYMBOL_GPL(scsi_block_targets); 3108 3109static void 3110device_unblock(struct scsi_device *sdev, void *data) 3111{ 3112 scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data); 3113} 3114 3115static int 3116target_unblock(struct device *dev, void *data) 3117{ 3118 if (scsi_is_target_device(dev)) 3119 starget_for_each_device(to_scsi_target(dev), data, 3120 device_unblock); 3121 return 0; 3122} 3123 3124void 3125scsi_target_unblock(struct device *dev, enum scsi_device_state new_state) 3126{ 3127 if (scsi_is_target_device(dev)) 3128 starget_for_each_device(to_scsi_target(dev), &new_state, 3129 device_unblock); 3130 else 3131 device_for_each_child(dev, &new_state, target_unblock); 3132} 3133EXPORT_SYMBOL_GPL(scsi_target_unblock); 3134 3135/** 3136 * scsi_host_block - Try to transition all logical units to the SDEV_BLOCK state 3137 * @shost: device to block 3138 * 3139 * Pause SCSI command processing for all logical units associated with the SCSI 3140 * host and wait until pending scsi_queue_rq() calls have finished. 3141 * 3142 * Returns zero if successful or a negative error code upon failure. 3143 */ 3144int 3145scsi_host_block(struct Scsi_Host *shost) 3146{ 3147 struct scsi_device *sdev; 3148 int ret; 3149 3150 /* 3151 * Call scsi_internal_device_block_nowait so we can avoid 3152 * calling synchronize_rcu() for each LUN. 3153 */ 3154 shost_for_each_device(sdev, shost) { 3155 mutex_lock(&sdev->state_mutex); 3156 ret = scsi_internal_device_block_nowait(sdev); 3157 mutex_unlock(&sdev->state_mutex); 3158 if (ret) { 3159 scsi_device_put(sdev); 3160 return ret; 3161 } 3162 } 3163 3164 /* Wait for ongoing scsi_queue_rq() calls to finish. */ 3165 blk_mq_wait_quiesce_done(&shost->tag_set); 3166 3167 return 0; 3168} 3169EXPORT_SYMBOL_GPL(scsi_host_block); 3170 3171int 3172scsi_host_unblock(struct Scsi_Host *shost, int new_state) 3173{ 3174 struct scsi_device *sdev; 3175 int ret = 0; 3176 3177 shost_for_each_device(sdev, shost) { 3178 ret = scsi_internal_device_unblock(sdev, new_state); 3179 if (ret) { 3180 scsi_device_put(sdev); 3181 break; 3182 } 3183 } 3184 return ret; 3185} 3186EXPORT_SYMBOL_GPL(scsi_host_unblock); 3187 3188/** 3189 * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt 3190 * @sgl: scatter-gather list 3191 * @sg_count: number of segments in sg 3192 * @offset: offset in bytes into sg, on return offset into the mapped area 3193 * @len: bytes to map, on return number of bytes mapped 3194 * 3195 * Returns virtual address of the start of the mapped page 3196 */ 3197void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count, 3198 size_t *offset, size_t *len) 3199{ 3200 int i; 3201 size_t sg_len = 0, len_complete = 0; 3202 struct scatterlist *sg; 3203 struct page *page; 3204 3205 WARN_ON(!irqs_disabled()); 3206 3207 for_each_sg(sgl, sg, sg_count, i) { 3208 len_complete = sg_len; /* Complete sg-entries */ 3209 sg_len += sg->length; 3210 if (sg_len > *offset) 3211 break; 3212 } 3213 3214 if (unlikely(i == sg_count)) { 3215 printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " 3216 "elements %d\n", 3217 __func__, sg_len, *offset, sg_count); 3218 WARN_ON(1); 3219 return NULL; 3220 } 3221 3222 /* Offset starting from the beginning of first page in this sg-entry */ 3223 *offset = *offset - len_complete + sg->offset; 3224 3225 page = sg_page(sg) + (*offset >> PAGE_SHIFT); 3226 *offset &= ~PAGE_MASK; 3227 3228 /* Bytes in this sg-entry from *offset to the end of the page */ 3229 sg_len = PAGE_SIZE - *offset; 3230 if (*len > sg_len) 3231 *len = sg_len; 3232 3233 return kmap_atomic(page); 3234} 3235EXPORT_SYMBOL(scsi_kmap_atomic_sg); 3236 3237/** 3238 * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg 3239 * @virt: virtual address to be unmapped 3240 */ 3241void scsi_kunmap_atomic_sg(void *virt) 3242{ 3243 kunmap_atomic(virt); 3244} 3245EXPORT_SYMBOL(scsi_kunmap_atomic_sg); 3246 3247void sdev_disable_disk_events(struct scsi_device *sdev) 3248{ 3249 atomic_inc(&sdev->disk_events_disable_depth); 3250} 3251EXPORT_SYMBOL(sdev_disable_disk_events); 3252 3253void sdev_enable_disk_events(struct scsi_device *sdev) 3254{ 3255 if (WARN_ON_ONCE(atomic_read(&sdev->disk_events_disable_depth) <= 0)) 3256 return; 3257 atomic_dec(&sdev->disk_events_disable_depth); 3258} 3259EXPORT_SYMBOL(sdev_enable_disk_events); 3260 3261static unsigned char designator_prio(const unsigned char *d) 3262{ 3263 if (d[1] & 0x30) 3264 /* not associated with LUN */ 3265 return 0; 3266 3267 if (d[3] == 0) 3268 /* invalid length */ 3269 return 0; 3270 3271 /* 3272 * Order of preference for lun descriptor: 3273 * - SCSI name string 3274 * - NAA IEEE Registered Extended 3275 * - EUI-64 based 16-byte 3276 * - EUI-64 based 12-byte 3277 * - NAA IEEE Registered 3278 * - NAA IEEE Extended 3279 * - EUI-64 based 8-byte 3280 * - SCSI name string (truncated) 3281 * - T10 Vendor ID 3282 * as longer descriptors reduce the likelyhood 3283 * of identification clashes. 3284 */ 3285 3286 switch (d[1] & 0xf) { 3287 case 8: 3288 /* SCSI name string, variable-length UTF-8 */ 3289 return 9; 3290 case 3: 3291 switch (d[4] >> 4) { 3292 case 6: 3293 /* NAA registered extended */ 3294 return 8; 3295 case 5: 3296 /* NAA registered */ 3297 return 5; 3298 case 4: 3299 /* NAA extended */ 3300 return 4; 3301 case 3: 3302 /* NAA locally assigned */ 3303 return 1; 3304 default: 3305 break; 3306 } 3307 break; 3308 case 2: 3309 switch (d[3]) { 3310 case 16: 3311 /* EUI64-based, 16 byte */ 3312 return 7; 3313 case 12: 3314 /* EUI64-based, 12 byte */ 3315 return 6; 3316 case 8: 3317 /* EUI64-based, 8 byte */ 3318 return 3; 3319 default: 3320 break; 3321 } 3322 break; 3323 case 1: 3324 /* T10 vendor ID */ 3325 return 1; 3326 default: 3327 break; 3328 } 3329 3330 return 0; 3331} 3332 3333/** 3334 * scsi_vpd_lun_id - return a unique device identification 3335 * @sdev: SCSI device 3336 * @id: buffer for the identification 3337 * @id_len: length of the buffer 3338 * 3339 * Copies a unique device identification into @id based 3340 * on the information in the VPD page 0x83 of the device. 3341 * The string will be formatted as a SCSI name string. 3342 * 3343 * Returns the length of the identification or error on failure. 3344 * If the identifier is longer than the supplied buffer the actual 3345 * identifier length is returned and the buffer is not zero-padded. 3346 */ 3347int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len) 3348{ 3349 u8 cur_id_prio = 0; 3350 u8 cur_id_size = 0; 3351 const unsigned char *d, *cur_id_str; 3352 const struct scsi_vpd *vpd_pg83; 3353 int id_size = -EINVAL; 3354 3355 rcu_read_lock(); 3356 vpd_pg83 = rcu_dereference(sdev->vpd_pg83); 3357 if (!vpd_pg83) { 3358 rcu_read_unlock(); 3359 return -ENXIO; 3360 } 3361 3362 /* The id string must be at least 20 bytes + terminating NULL byte */ 3363 if (id_len < 21) { 3364 rcu_read_unlock(); 3365 return -EINVAL; 3366 } 3367 3368 memset(id, 0, id_len); 3369 for (d = vpd_pg83->data + 4; 3370 d < vpd_pg83->data + vpd_pg83->len; 3371 d += d[3] + 4) { 3372 u8 prio = designator_prio(d); 3373 3374 if (prio == 0 || cur_id_prio > prio) 3375 continue; 3376 3377 switch (d[1] & 0xf) { 3378 case 0x1: 3379 /* T10 Vendor ID */ 3380 if (cur_id_size > d[3]) 3381 break; 3382 cur_id_prio = prio; 3383 cur_id_size = d[3]; 3384 if (cur_id_size + 4 > id_len) 3385 cur_id_size = id_len - 4; 3386 cur_id_str = d + 4; 3387 id_size = snprintf(id, id_len, "t10.%*pE", 3388 cur_id_size, cur_id_str); 3389 break; 3390 case 0x2: 3391 /* EUI-64 */ 3392 cur_id_prio = prio; 3393 cur_id_size = d[3]; 3394 cur_id_str = d + 4; 3395 switch (cur_id_size) { 3396 case 8: 3397 id_size = snprintf(id, id_len, 3398 "eui.%8phN", 3399 cur_id_str); 3400 break; 3401 case 12: 3402 id_size = snprintf(id, id_len, 3403 "eui.%12phN", 3404 cur_id_str); 3405 break; 3406 case 16: 3407 id_size = snprintf(id, id_len, 3408 "eui.%16phN", 3409 cur_id_str); 3410 break; 3411 default: 3412 break; 3413 } 3414 break; 3415 case 0x3: 3416 /* NAA */ 3417 cur_id_prio = prio; 3418 cur_id_size = d[3]; 3419 cur_id_str = d + 4; 3420 switch (cur_id_size) { 3421 case 8: 3422 id_size = snprintf(id, id_len, 3423 "naa.%8phN", 3424 cur_id_str); 3425 break; 3426 case 16: 3427 id_size = snprintf(id, id_len, 3428 "naa.%16phN", 3429 cur_id_str); 3430 break; 3431 default: 3432 break; 3433 } 3434 break; 3435 case 0x8: 3436 /* SCSI name string */ 3437 if (cur_id_size > d[3]) 3438 break; 3439 /* Prefer others for truncated descriptor */ 3440 if (d[3] > id_len) { 3441 prio = 2; 3442 if (cur_id_prio > prio) 3443 break; 3444 } 3445 cur_id_prio = prio; 3446 cur_id_size = id_size = d[3]; 3447 cur_id_str = d + 4; 3448 if (cur_id_size >= id_len) 3449 cur_id_size = id_len - 1; 3450 memcpy(id, cur_id_str, cur_id_size); 3451 break; 3452 default: 3453 break; 3454 } 3455 } 3456 rcu_read_unlock(); 3457 3458 return id_size; 3459} 3460EXPORT_SYMBOL(scsi_vpd_lun_id); 3461 3462/** 3463 * scsi_vpd_tpg_id - return a target port group identifier 3464 * @sdev: SCSI device 3465 * @rel_id: pointer to return relative target port in if not %NULL 3466 * 3467 * Returns the Target Port Group identifier from the information 3468 * from VPD page 0x83 of the device. 3469 * Optionally sets @rel_id to the relative target port on success. 3470 * 3471 * Return: the identifier or error on failure. 3472 */ 3473int scsi_vpd_tpg_id(struct scsi_device *sdev, int *rel_id) 3474{ 3475 const unsigned char *d; 3476 const struct scsi_vpd *vpd_pg83; 3477 int group_id = -EAGAIN, rel_port = -1; 3478 3479 rcu_read_lock(); 3480 vpd_pg83 = rcu_dereference(sdev->vpd_pg83); 3481 if (!vpd_pg83) { 3482 rcu_read_unlock(); 3483 return -ENXIO; 3484 } 3485 3486 d = vpd_pg83->data + 4; 3487 while (d < vpd_pg83->data + vpd_pg83->len) { 3488 switch (d[1] & 0xf) { 3489 case 0x4: 3490 /* Relative target port */ 3491 rel_port = get_unaligned_be16(&d[6]); 3492 break; 3493 case 0x5: 3494 /* Target port group */ 3495 group_id = get_unaligned_be16(&d[6]); 3496 break; 3497 default: 3498 break; 3499 } 3500 d += d[3] + 4; 3501 } 3502 rcu_read_unlock(); 3503 3504 if (group_id >= 0 && rel_id && rel_port != -1) 3505 *rel_id = rel_port; 3506 3507 return group_id; 3508} 3509EXPORT_SYMBOL(scsi_vpd_tpg_id); 3510 3511/** 3512 * scsi_build_sense - build sense data for a command 3513 * @scmd: scsi command for which the sense should be formatted 3514 * @desc: Sense format (non-zero == descriptor format, 3515 * 0 == fixed format) 3516 * @key: Sense key 3517 * @asc: Additional sense code 3518 * @ascq: Additional sense code qualifier 3519 * 3520 **/ 3521void scsi_build_sense(struct scsi_cmnd *scmd, int desc, u8 key, u8 asc, u8 ascq) 3522{ 3523 scsi_build_sense_buffer(desc, scmd->sense_buffer, key, asc, ascq); 3524 scmd->result = SAM_STAT_CHECK_CONDITION; 3525} 3526EXPORT_SYMBOL_GPL(scsi_build_sense); 3527 3528#ifdef CONFIG_SCSI_LIB_KUNIT_TEST 3529#include "scsi_lib_test.c" 3530#endif
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