1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 1999 Eric Youngdale
4 * Copyright (C) 2014 Christoph Hellwig
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.
12 #include <linux/bio.h>
13 #include <linux/bitops.h>
14 #include <linux/blkdev.h>
15 #include <linux/completion.h>
16 #include <linux/kernel.h>
17 #include <linux/export.h>
18 #include <linux/init.h>
19 #include <linux/pci.h>
20 #include <linux/delay.h>
21 #include <linux/hardirq.h>
22 #include <linux/scatterlist.h>
23 #include <linux/blk-mq.h>
24 #include <linux/blk-integrity.h>
25 #include <linux/ratelimit.h>
26 #include <asm/unaligned.h>
28 #include <scsi/scsi.h>
29 #include <scsi/scsi_cmnd.h>
30 #include <scsi/scsi_dbg.h>
31 #include <scsi/scsi_device.h>
32 #include <scsi/scsi_driver.h>
33 #include <scsi/scsi_eh.h>
34 #include <scsi/scsi_host.h>
35 #include <scsi/scsi_transport.h> /* __scsi_init_queue() */
36 #include <scsi/scsi_dh.h>
38 #include <trace/events/scsi.h>
40 #include "scsi_debugfs.h"
41 #include "scsi_priv.h"
42 #include "scsi_logging.h"
45 * Size of integrity metadata is usually small, 1 inline sg should
48 #ifdef CONFIG_ARCH_NO_SG_CHAIN
49 #define SCSI_INLINE_PROT_SG_CNT 0
50 #define SCSI_INLINE_SG_CNT 0
52 #define SCSI_INLINE_PROT_SG_CNT 1
53 #define SCSI_INLINE_SG_CNT 2
56 static struct kmem_cache *scsi_sense_cache;
57 static DEFINE_MUTEX(scsi_sense_cache_mutex);
59 static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd);
61 int scsi_init_sense_cache(struct Scsi_Host *shost)
65 mutex_lock(&scsi_sense_cache_mutex);
66 if (!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)
74 mutex_unlock(&scsi_sense_cache_mutex);
79 scsi_set_blocked(struct scsi_cmnd *cmd, int reason)
81 struct Scsi_Host *host = cmd->device->host;
82 struct scsi_device *device = cmd->device;
83 struct scsi_target *starget = scsi_target(device);
86 * Set the appropriate busy bit for the device/host.
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.
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.
99 case SCSI_MLQUEUE_HOST_BUSY:
100 atomic_set(&host->host_blocked, host->max_host_blocked);
102 case SCSI_MLQUEUE_DEVICE_BUSY:
103 case SCSI_MLQUEUE_EH_RETRY:
104 atomic_set(&device->device_blocked,
105 device->max_device_blocked);
107 case SCSI_MLQUEUE_TARGET_BUSY:
108 atomic_set(&starget->target_blocked,
109 starget->max_target_blocked);
114 static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd, unsigned long msecs)
116 struct request *rq = scsi_cmd_to_rq(cmd);
118 if (rq->rq_flags & RQF_DONTPREP) {
119 rq->rq_flags &= ~RQF_DONTPREP;
120 scsi_mq_uninit_cmd(cmd);
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);
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
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
142 static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy)
144 struct scsi_device *device = cmd->device;
146 SCSI_LOG_MLQUEUE(1, scmd_printk(KERN_INFO, cmd,
147 "Inserting command %p into mlqueue\n", cmd));
149 scsi_set_blocked(cmd, reason);
152 * Decrement the counters, since these commands are no longer
153 * active on the host/device.
156 scsi_device_unbusy(device, cmd);
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.
166 blk_mq_requeue_request(scsi_cmd_to_rq(cmd),
167 !scsi_host_in_recovery(cmd->device->host));
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.
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.
179 * Context: This could be called either from an interrupt context or a normal
182 void scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
184 __scsi_queue_insert(cmd, reason, true);
188 * scsi_execute_cmd - insert request and wait for the result
191 * @opf: block layer request cmd_flags
192 * @buffer: data buffer
193 * @bufflen: len of buffer
194 * @timeout: request timeout in HZ
195 * @retries: number of times to retry request
196 * @args: Optional args. See struct definition for field descriptions
198 * Returns the scsi_cmnd result field if a command was executed, or a negative
199 * Linux error code if we didn't get that far.
201 int scsi_execute_cmd(struct scsi_device *sdev, const unsigned char *cmd,
202 blk_opf_t opf, void *buffer, unsigned int bufflen,
203 int timeout, int retries,
204 const struct scsi_exec_args *args)
206 static const struct scsi_exec_args default_args;
208 struct scsi_cmnd *scmd;
212 args = &default_args;
213 else if (WARN_ON_ONCE(args->sense &&
214 args->sense_len != SCSI_SENSE_BUFFERSIZE))
217 req = scsi_alloc_request(sdev->request_queue, opf, args->req_flags);
222 ret = blk_rq_map_kern(sdev->request_queue, req,
223 buffer, bufflen, GFP_NOIO);
227 scmd = blk_mq_rq_to_pdu(req);
228 scmd->cmd_len = COMMAND_SIZE(cmd[0]);
229 memcpy(scmd->cmnd, cmd, scmd->cmd_len);
230 scmd->allowed = retries;
231 scmd->flags |= args->scmd_flags;
232 req->timeout = timeout;
233 req->rq_flags |= RQF_QUIET;
236 * head injection *required* here otherwise quiesce won't work
238 blk_execute_rq(req, true);
241 * Some devices (USB mass-storage in particular) may transfer
242 * garbage data together with a residue indicating that the data
243 * is invalid. Prevent the garbage from being misinterpreted
244 * and prevent security leaks by zeroing out the excess data.
246 if (unlikely(scmd->resid_len > 0 && scmd->resid_len <= bufflen))
247 memset(buffer + bufflen - scmd->resid_len, 0, scmd->resid_len);
250 *args->resid = scmd->resid_len;
252 memcpy(args->sense, scmd->sense_buffer, SCSI_SENSE_BUFFERSIZE);
254 scsi_normalize_sense(scmd->sense_buffer, scmd->sense_len,
259 blk_mq_free_request(req);
263 EXPORT_SYMBOL(scsi_execute_cmd);
266 * Wake up the error handler if necessary. Avoid as follows that the error
267 * handler is not woken up if host in-flight requests number ==
268 * shost->host_failed: use call_rcu() in scsi_eh_scmd_add() in combination
269 * with an RCU read lock in this function to ensure that this function in
270 * its entirety either finishes before scsi_eh_scmd_add() increases the
271 * host_failed counter or that it notices the shost state change made by
272 * scsi_eh_scmd_add().
274 static void scsi_dec_host_busy(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
279 __clear_bit(SCMD_STATE_INFLIGHT, &cmd->state);
280 if (unlikely(scsi_host_in_recovery(shost))) {
281 spin_lock_irqsave(shost->host_lock, flags);
282 if (shost->host_failed || shost->host_eh_scheduled)
283 scsi_eh_wakeup(shost);
284 spin_unlock_irqrestore(shost->host_lock, flags);
289 void scsi_device_unbusy(struct scsi_device *sdev, struct scsi_cmnd *cmd)
291 struct Scsi_Host *shost = sdev->host;
292 struct scsi_target *starget = scsi_target(sdev);
294 scsi_dec_host_busy(shost, cmd);
296 if (starget->can_queue > 0)
297 atomic_dec(&starget->target_busy);
299 sbitmap_put(&sdev->budget_map, cmd->budget_token);
300 cmd->budget_token = -1;
303 static void scsi_kick_queue(struct request_queue *q)
305 blk_mq_run_hw_queues(q, false);
309 * Kick the queue of SCSI device @sdev if @sdev != current_sdev. Called with
310 * interrupts disabled.
312 static void scsi_kick_sdev_queue(struct scsi_device *sdev, void *data)
314 struct scsi_device *current_sdev = data;
316 if (sdev != current_sdev)
317 blk_mq_run_hw_queues(sdev->request_queue, true);
321 * Called for single_lun devices on IO completion. Clear starget_sdev_user,
322 * and call blk_run_queue for all the scsi_devices on the target -
323 * including current_sdev first.
325 * Called with *no* scsi locks held.
327 static void scsi_single_lun_run(struct scsi_device *current_sdev)
329 struct Scsi_Host *shost = current_sdev->host;
330 struct scsi_target *starget = scsi_target(current_sdev);
333 spin_lock_irqsave(shost->host_lock, flags);
334 starget->starget_sdev_user = NULL;
335 spin_unlock_irqrestore(shost->host_lock, flags);
338 * Call blk_run_queue for all LUNs on the target, starting with
339 * current_sdev. We race with others (to set starget_sdev_user),
340 * but in most cases, we will be first. Ideally, each LU on the
341 * target would get some limited time or requests on the target.
343 scsi_kick_queue(current_sdev->request_queue);
345 spin_lock_irqsave(shost->host_lock, flags);
346 if (!starget->starget_sdev_user)
347 __starget_for_each_device(starget, current_sdev,
348 scsi_kick_sdev_queue);
349 spin_unlock_irqrestore(shost->host_lock, flags);
352 static inline bool scsi_device_is_busy(struct scsi_device *sdev)
354 if (scsi_device_busy(sdev) >= sdev->queue_depth)
356 if (atomic_read(&sdev->device_blocked) > 0)
361 static inline bool scsi_target_is_busy(struct scsi_target *starget)
363 if (starget->can_queue > 0) {
364 if (atomic_read(&starget->target_busy) >= starget->can_queue)
366 if (atomic_read(&starget->target_blocked) > 0)
372 static inline bool scsi_host_is_busy(struct Scsi_Host *shost)
374 if (atomic_read(&shost->host_blocked) > 0)
376 if (shost->host_self_blocked)
381 static void scsi_starved_list_run(struct Scsi_Host *shost)
383 LIST_HEAD(starved_list);
384 struct scsi_device *sdev;
387 spin_lock_irqsave(shost->host_lock, flags);
388 list_splice_init(&shost->starved_list, &starved_list);
390 while (!list_empty(&starved_list)) {
391 struct request_queue *slq;
394 * As long as shost is accepting commands and we have
395 * starved queues, call blk_run_queue. scsi_request_fn
396 * drops the queue_lock and can add us back to the
399 * host_lock protects the starved_list and starved_entry.
400 * scsi_request_fn must get the host_lock before checking
401 * or modifying starved_list or starved_entry.
403 if (scsi_host_is_busy(shost))
406 sdev = list_entry(starved_list.next,
407 struct scsi_device, starved_entry);
408 list_del_init(&sdev->starved_entry);
409 if (scsi_target_is_busy(scsi_target(sdev))) {
410 list_move_tail(&sdev->starved_entry,
411 &shost->starved_list);
416 * Once we drop the host lock, a racing scsi_remove_device()
417 * call may remove the sdev from the starved list and destroy
418 * it and the queue. Mitigate by taking a reference to the
419 * queue and never touching the sdev again after we drop the
420 * host lock. Note: if __scsi_remove_device() invokes
421 * blk_mq_destroy_queue() before the queue is run from this
422 * function then blk_run_queue() will return immediately since
423 * blk_mq_destroy_queue() marks the queue with QUEUE_FLAG_DYING.
425 slq = sdev->request_queue;
426 if (!blk_get_queue(slq))
428 spin_unlock_irqrestore(shost->host_lock, flags);
430 scsi_kick_queue(slq);
433 spin_lock_irqsave(shost->host_lock, flags);
435 /* put any unprocessed entries back */
436 list_splice(&starved_list, &shost->starved_list);
437 spin_unlock_irqrestore(shost->host_lock, flags);
441 * scsi_run_queue - Select a proper request queue to serve next.
442 * @q: last request's queue
444 * The previous command was completely finished, start a new one if possible.
446 static void scsi_run_queue(struct request_queue *q)
448 struct scsi_device *sdev = q->queuedata;
450 if (scsi_target(sdev)->single_lun)
451 scsi_single_lun_run(sdev);
452 if (!list_empty(&sdev->host->starved_list))
453 scsi_starved_list_run(sdev->host);
455 blk_mq_kick_requeue_list(q);
456 blk_mq_run_hw_queues(q, false);
459 void scsi_requeue_run_queue(struct work_struct *work)
461 struct scsi_device *sdev;
462 struct request_queue *q;
464 sdev = container_of(work, struct scsi_device, requeue_work);
465 q = sdev->request_queue;
469 void scsi_run_host_queues(struct Scsi_Host *shost)
471 struct scsi_device *sdev;
473 shost_for_each_device(sdev, shost)
474 scsi_run_queue(sdev->request_queue);
477 static void scsi_uninit_cmd(struct scsi_cmnd *cmd)
479 if (!blk_rq_is_passthrough(scsi_cmd_to_rq(cmd))) {
480 struct scsi_driver *drv = scsi_cmd_to_driver(cmd);
482 if (drv->uninit_command)
483 drv->uninit_command(cmd);
487 void scsi_free_sgtables(struct scsi_cmnd *cmd)
489 if (cmd->sdb.table.nents)
490 sg_free_table_chained(&cmd->sdb.table,
492 if (scsi_prot_sg_count(cmd))
493 sg_free_table_chained(&cmd->prot_sdb->table,
494 SCSI_INLINE_PROT_SG_CNT);
496 EXPORT_SYMBOL_GPL(scsi_free_sgtables);
498 static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd)
500 scsi_free_sgtables(cmd);
501 scsi_uninit_cmd(cmd);
504 static void scsi_run_queue_async(struct scsi_device *sdev)
506 if (scsi_host_in_recovery(sdev->host))
509 if (scsi_target(sdev)->single_lun ||
510 !list_empty(&sdev->host->starved_list)) {
511 kblockd_schedule_work(&sdev->requeue_work);
514 * smp_mb() present in sbitmap_queue_clear() or implied in
515 * .end_io is for ordering writing .device_busy in
516 * scsi_device_unbusy() and reading sdev->restarts.
518 int old = atomic_read(&sdev->restarts);
521 * ->restarts has to be kept as non-zero if new budget
524 * No need to run queue when either another re-run
525 * queue wins in updating ->restarts or a new budget
528 if (old && atomic_cmpxchg(&sdev->restarts, old, 0) == old)
529 blk_mq_run_hw_queues(sdev->request_queue, true);
533 /* Returns false when no more bytes to process, true if there are more */
534 static bool scsi_end_request(struct request *req, blk_status_t error,
537 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
538 struct scsi_device *sdev = cmd->device;
539 struct request_queue *q = sdev->request_queue;
541 if (blk_update_request(req, error, bytes))
545 if (blk_queue_add_random(q))
546 add_disk_randomness(req->q->disk);
548 if (!blk_rq_is_passthrough(req)) {
549 WARN_ON_ONCE(!(cmd->flags & SCMD_INITIALIZED));
550 cmd->flags &= ~SCMD_INITIALIZED;
554 * Calling rcu_barrier() is not necessary here because the
555 * SCSI error handler guarantees that the function called by
556 * call_rcu() has been called before scsi_end_request() is
559 destroy_rcu_head(&cmd->rcu);
562 * In the MQ case the command gets freed by __blk_mq_end_request,
563 * so we have to do all cleanup that depends on it earlier.
565 * We also can't kick the queues from irq context, so we
566 * will have to defer it to a workqueue.
568 scsi_mq_uninit_cmd(cmd);
571 * queue is still alive, so grab the ref for preventing it
572 * from being cleaned up during running queue.
574 percpu_ref_get(&q->q_usage_counter);
576 __blk_mq_end_request(req, error);
578 scsi_run_queue_async(sdev);
580 percpu_ref_put(&q->q_usage_counter);
585 * scsi_result_to_blk_status - translate a SCSI result code into blk_status_t
586 * @result: scsi error code
588 * Translate a SCSI result code into a blk_status_t value.
590 static blk_status_t scsi_result_to_blk_status(int result)
593 * Check the scsi-ml byte first in case we converted a host or status
596 switch (scsi_ml_byte(result)) {
599 case SCSIML_STAT_RESV_CONFLICT:
600 return BLK_STS_RESV_CONFLICT;
601 case SCSIML_STAT_NOSPC:
602 return BLK_STS_NOSPC;
603 case SCSIML_STAT_MED_ERROR:
604 return BLK_STS_MEDIUM;
605 case SCSIML_STAT_TGT_FAILURE:
606 return BLK_STS_TARGET;
607 case SCSIML_STAT_DL_TIMEOUT:
608 return BLK_STS_DURATION_LIMIT;
611 switch (host_byte(result)) {
613 if (scsi_status_is_good(result))
615 return BLK_STS_IOERR;
616 case DID_TRANSPORT_FAILFAST:
617 case DID_TRANSPORT_MARGINAL:
618 return BLK_STS_TRANSPORT;
620 return BLK_STS_IOERR;
625 * scsi_rq_err_bytes - determine number of bytes till the next failure boundary
626 * @rq: request to examine
629 * A request could be merge of IOs which require different failure
630 * handling. This function determines the number of bytes which
631 * can be failed from the beginning of the request without
632 * crossing into area which need to be retried further.
635 * The number of bytes to fail.
637 static unsigned int scsi_rq_err_bytes(const struct request *rq)
639 blk_opf_t ff = rq->cmd_flags & REQ_FAILFAST_MASK;
640 unsigned int bytes = 0;
643 if (!(rq->rq_flags & RQF_MIXED_MERGE))
644 return blk_rq_bytes(rq);
647 * Currently the only 'mixing' which can happen is between
648 * different fastfail types. We can safely fail portions
649 * which have all the failfast bits that the first one has -
650 * the ones which are at least as eager to fail as the first
653 for (bio = rq->bio; bio; bio = bio->bi_next) {
654 if ((bio->bi_opf & ff) != ff)
656 bytes += bio->bi_iter.bi_size;
659 /* this could lead to infinite loop */
660 BUG_ON(blk_rq_bytes(rq) && !bytes);
664 static bool scsi_cmd_runtime_exceeced(struct scsi_cmnd *cmd)
666 struct request *req = scsi_cmd_to_rq(cmd);
667 unsigned long wait_for;
669 if (cmd->allowed == SCSI_CMD_RETRIES_NO_LIMIT)
672 wait_for = (cmd->allowed + 1) * req->timeout;
673 if (time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) {
674 scmd_printk(KERN_ERR, cmd, "timing out command, waited %lus\n",
682 * When ALUA transition state is returned, reprep the cmd to
683 * use the ALUA handler's transition timeout. Delay the reprep
684 * 1 sec to avoid aggressive retries of the target in that
687 #define ALUA_TRANSITION_REPREP_DELAY 1000
689 /* Helper for scsi_io_completion() when special action required. */
690 static void scsi_io_completion_action(struct scsi_cmnd *cmd, int result)
692 struct request *req = scsi_cmd_to_rq(cmd);
694 enum {ACTION_FAIL, ACTION_REPREP, ACTION_DELAYED_REPREP,
695 ACTION_RETRY, ACTION_DELAYED_RETRY} action;
696 struct scsi_sense_hdr sshdr;
698 bool sense_current = true; /* false implies "deferred sense" */
699 blk_status_t blk_stat;
701 sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
703 sense_current = !scsi_sense_is_deferred(&sshdr);
705 blk_stat = scsi_result_to_blk_status(result);
707 if (host_byte(result) == DID_RESET) {
708 /* Third party bus reset or reset for error recovery
709 * reasons. Just retry the command and see what
712 action = ACTION_RETRY;
713 } else if (sense_valid && sense_current) {
714 switch (sshdr.sense_key) {
716 if (cmd->device->removable) {
717 /* Detected disc change. Set a bit
718 * and quietly refuse further access.
720 cmd->device->changed = 1;
721 action = ACTION_FAIL;
723 /* Must have been a power glitch, or a
724 * bus reset. Could not have been a
725 * media change, so we just retry the
726 * command and see what happens.
728 action = ACTION_RETRY;
731 case ILLEGAL_REQUEST:
732 /* If we had an ILLEGAL REQUEST returned, then
733 * we may have performed an unsupported
734 * command. The only thing this should be
735 * would be a ten byte read where only a six
736 * byte read was supported. Also, on a system
737 * where READ CAPACITY failed, we may have
738 * read past the end of the disk.
740 if ((cmd->device->use_10_for_rw &&
741 sshdr.asc == 0x20 && sshdr.ascq == 0x00) &&
742 (cmd->cmnd[0] == READ_10 ||
743 cmd->cmnd[0] == WRITE_10)) {
744 /* This will issue a new 6-byte command. */
745 cmd->device->use_10_for_rw = 0;
746 action = ACTION_REPREP;
747 } else if (sshdr.asc == 0x10) /* DIX */ {
748 action = ACTION_FAIL;
749 blk_stat = BLK_STS_PROTECTION;
750 /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
751 } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) {
752 action = ACTION_FAIL;
753 blk_stat = BLK_STS_TARGET;
755 action = ACTION_FAIL;
757 case ABORTED_COMMAND:
758 action = ACTION_FAIL;
759 if (sshdr.asc == 0x10) /* DIF */
760 blk_stat = BLK_STS_PROTECTION;
763 /* If the device is in the process of becoming
764 * ready, or has a temporary blockage, retry.
766 if (sshdr.asc == 0x04) {
767 switch (sshdr.ascq) {
768 case 0x01: /* becoming ready */
769 case 0x04: /* format in progress */
770 case 0x05: /* rebuild in progress */
771 case 0x06: /* recalculation in progress */
772 case 0x07: /* operation in progress */
773 case 0x08: /* Long write in progress */
774 case 0x09: /* self test in progress */
775 case 0x11: /* notify (enable spinup) required */
776 case 0x14: /* space allocation in progress */
777 case 0x1a: /* start stop unit in progress */
778 case 0x1b: /* sanitize in progress */
779 case 0x1d: /* configuration in progress */
780 case 0x24: /* depopulation in progress */
781 action = ACTION_DELAYED_RETRY;
783 case 0x0a: /* ALUA state transition */
784 action = ACTION_DELAYED_REPREP;
787 action = ACTION_FAIL;
791 action = ACTION_FAIL;
793 case VOLUME_OVERFLOW:
794 /* See SSC3rXX or current. */
795 action = ACTION_FAIL;
798 action = ACTION_FAIL;
799 if ((sshdr.asc == 0x0C && sshdr.ascq == 0x12) ||
800 (sshdr.asc == 0x55 &&
801 (sshdr.ascq == 0x0E || sshdr.ascq == 0x0F))) {
802 /* Insufficient zone resources */
803 blk_stat = BLK_STS_ZONE_OPEN_RESOURCE;
809 action = ACTION_FAIL;
813 action = ACTION_FAIL;
815 if (action != ACTION_FAIL && scsi_cmd_runtime_exceeced(cmd))
816 action = ACTION_FAIL;
820 /* Give up and fail the remainder of the request */
821 if (!(req->rq_flags & RQF_QUIET)) {
822 static DEFINE_RATELIMIT_STATE(_rs,
823 DEFAULT_RATELIMIT_INTERVAL,
824 DEFAULT_RATELIMIT_BURST);
826 if (unlikely(scsi_logging_level))
828 SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
829 SCSI_LOG_MLCOMPLETE_BITS);
832 * if logging is enabled the failure will be printed
833 * in scsi_log_completion(), so avoid duplicate messages
835 if (!level && __ratelimit(&_rs)) {
836 scsi_print_result(cmd, NULL, FAILED);
838 scsi_print_sense(cmd);
839 scsi_print_command(cmd);
842 if (!scsi_end_request(req, blk_stat, scsi_rq_err_bytes(req)))
846 scsi_mq_requeue_cmd(cmd, 0);
848 case ACTION_DELAYED_REPREP:
849 scsi_mq_requeue_cmd(cmd, ALUA_TRANSITION_REPREP_DELAY);
852 /* Retry the same command immediately */
853 __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, false);
855 case ACTION_DELAYED_RETRY:
856 /* Retry the same command after a delay */
857 __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, false);
863 * Helper for scsi_io_completion() when cmd->result is non-zero. Returns a
864 * new result that may suppress further error checking. Also modifies
865 * *blk_statp in some cases.
867 static int scsi_io_completion_nz_result(struct scsi_cmnd *cmd, int result,
868 blk_status_t *blk_statp)
871 bool sense_current = true; /* false implies "deferred sense" */
872 struct request *req = scsi_cmd_to_rq(cmd);
873 struct scsi_sense_hdr sshdr;
875 sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
877 sense_current = !scsi_sense_is_deferred(&sshdr);
879 if (blk_rq_is_passthrough(req)) {
882 * SG_IO wants current and deferred errors
884 cmd->sense_len = min(8 + cmd->sense_buffer[7],
885 SCSI_SENSE_BUFFERSIZE);
888 *blk_statp = scsi_result_to_blk_status(result);
889 } else if (blk_rq_bytes(req) == 0 && sense_current) {
891 * Flush commands do not transfers any data, and thus cannot use
892 * good_bytes != blk_rq_bytes(req) as the signal for an error.
893 * This sets *blk_statp explicitly for the problem case.
895 *blk_statp = scsi_result_to_blk_status(result);
898 * Recovered errors need reporting, but they're always treated as
899 * success, so fiddle the result code here. For passthrough requests
900 * we already took a copy of the original into sreq->result which
901 * is what gets returned to the user
903 if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) {
904 bool do_print = true;
906 * if ATA PASS-THROUGH INFORMATION AVAILABLE [0x0, 0x1d]
907 * skip print since caller wants ATA registers. Only occurs
908 * on SCSI ATA PASS_THROUGH commands when CK_COND=1
910 if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d))
912 else if (req->rq_flags & RQF_QUIET)
915 scsi_print_sense(cmd);
917 /* for passthrough, *blk_statp may be set */
918 *blk_statp = BLK_STS_OK;
921 * Another corner case: the SCSI status byte is non-zero but 'good'.
922 * Example: PRE-FETCH command returns SAM_STAT_CONDITION_MET when
923 * it is able to fit nominated LBs in its cache (and SAM_STAT_GOOD
924 * if it can't fit). Treat SAM_STAT_CONDITION_MET and the related
925 * intermediate statuses (both obsolete in SAM-4) as good.
927 if ((result & 0xff) && scsi_status_is_good(result)) {
929 *blk_statp = BLK_STS_OK;
935 * scsi_io_completion - Completion processing for SCSI commands.
936 * @cmd: command that is finished.
937 * @good_bytes: number of processed bytes.
939 * We will finish off the specified number of sectors. If we are done, the
940 * command block will be released and the queue function will be goosed. If we
941 * are not done then we have to figure out what to do next:
943 * a) We can call scsi_mq_requeue_cmd(). The request will be
944 * unprepared and put back on the queue. Then a new command will
945 * be created for it. This should be used if we made forward
946 * progress, or if we want to switch from READ(10) to READ(6) for
949 * b) We can call scsi_io_completion_action(). The request will be
950 * put back on the queue and retried using the same command as
951 * before, possibly after a delay.
953 * c) We can call scsi_end_request() with blk_stat other than
954 * BLK_STS_OK, to fail the remainder of the request.
956 void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
958 int result = cmd->result;
959 struct request *req = scsi_cmd_to_rq(cmd);
960 blk_status_t blk_stat = BLK_STS_OK;
962 if (unlikely(result)) /* a nz result may or may not be an error */
963 result = scsi_io_completion_nz_result(cmd, result, &blk_stat);
966 * Next deal with any sectors which we were able to correctly
969 SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, cmd,
970 "%u sectors total, %d bytes done.\n",
971 blk_rq_sectors(req), good_bytes));
974 * Failed, zero length commands always need to drop down
975 * to retry code. Fast path should return in this block.
977 if (likely(blk_rq_bytes(req) > 0 || blk_stat == BLK_STS_OK)) {
978 if (likely(!scsi_end_request(req, blk_stat, good_bytes)))
979 return; /* no bytes remaining */
982 /* Kill remainder if no retries. */
983 if (unlikely(blk_stat && scsi_noretry_cmd(cmd))) {
984 if (scsi_end_request(req, blk_stat, blk_rq_bytes(req)))
986 "Bytes remaining after failed, no-retry command");
991 * If there had been no error, but we have leftover bytes in the
992 * request just queue the command up again.
994 if (likely(result == 0))
995 scsi_mq_requeue_cmd(cmd, 0);
997 scsi_io_completion_action(cmd, result);
1000 static inline bool scsi_cmd_needs_dma_drain(struct scsi_device *sdev,
1003 return sdev->dma_drain_len && blk_rq_is_passthrough(rq) &&
1004 !op_is_write(req_op(rq)) &&
1005 sdev->host->hostt->dma_need_drain(rq);
1009 * scsi_alloc_sgtables - Allocate and initialize data and integrity scatterlists
1010 * @cmd: SCSI command data structure to initialize.
1012 * Initializes @cmd->sdb and also @cmd->prot_sdb if data integrity is enabled
1016 * * BLK_STS_OK - on success
1017 * * BLK_STS_RESOURCE - if the failure is retryable
1018 * * BLK_STS_IOERR - if the failure is fatal
1020 blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd)
1022 struct scsi_device *sdev = cmd->device;
1023 struct request *rq = scsi_cmd_to_rq(cmd);
1024 unsigned short nr_segs = blk_rq_nr_phys_segments(rq);
1025 struct scatterlist *last_sg = NULL;
1027 bool need_drain = scsi_cmd_needs_dma_drain(sdev, rq);
1030 if (WARN_ON_ONCE(!nr_segs))
1031 return BLK_STS_IOERR;
1034 * Make sure there is space for the drain. The driver must adjust
1035 * max_hw_segments to be prepared for this.
1041 * If sg table allocation fails, requeue request later.
1043 if (unlikely(sg_alloc_table_chained(&cmd->sdb.table, nr_segs,
1044 cmd->sdb.table.sgl, SCSI_INLINE_SG_CNT)))
1045 return BLK_STS_RESOURCE;
1048 * Next, walk the list, and fill in the addresses and sizes of
1051 count = __blk_rq_map_sg(rq->q, rq, cmd->sdb.table.sgl, &last_sg);
1053 if (blk_rq_bytes(rq) & rq->q->dma_pad_mask) {
1054 unsigned int pad_len =
1055 (rq->q->dma_pad_mask & ~blk_rq_bytes(rq)) + 1;
1057 last_sg->length += pad_len;
1058 cmd->extra_len += pad_len;
1062 sg_unmark_end(last_sg);
1063 last_sg = sg_next(last_sg);
1064 sg_set_buf(last_sg, sdev->dma_drain_buf, sdev->dma_drain_len);
1065 sg_mark_end(last_sg);
1067 cmd->extra_len += sdev->dma_drain_len;
1071 BUG_ON(count > cmd->sdb.table.nents);
1072 cmd->sdb.table.nents = count;
1073 cmd->sdb.length = blk_rq_payload_bytes(rq);
1075 if (blk_integrity_rq(rq)) {
1076 struct scsi_data_buffer *prot_sdb = cmd->prot_sdb;
1079 if (WARN_ON_ONCE(!prot_sdb)) {
1081 * This can happen if someone (e.g. multipath)
1082 * queues a command to a device on an adapter
1083 * that does not support DIX.
1085 ret = BLK_STS_IOERR;
1086 goto out_free_sgtables;
1089 ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio);
1091 if (sg_alloc_table_chained(&prot_sdb->table, ivecs,
1092 prot_sdb->table.sgl,
1093 SCSI_INLINE_PROT_SG_CNT)) {
1094 ret = BLK_STS_RESOURCE;
1095 goto out_free_sgtables;
1098 count = blk_rq_map_integrity_sg(rq->q, rq->bio,
1099 prot_sdb->table.sgl);
1100 BUG_ON(count > ivecs);
1101 BUG_ON(count > queue_max_integrity_segments(rq->q));
1103 cmd->prot_sdb = prot_sdb;
1104 cmd->prot_sdb->table.nents = count;
1109 scsi_free_sgtables(cmd);
1112 EXPORT_SYMBOL(scsi_alloc_sgtables);
1115 * scsi_initialize_rq - initialize struct scsi_cmnd partially
1116 * @rq: Request associated with the SCSI command to be initialized.
1118 * This function initializes the members of struct scsi_cmnd that must be
1119 * initialized before request processing starts and that won't be
1120 * reinitialized if a SCSI command is requeued.
1122 static void scsi_initialize_rq(struct request *rq)
1124 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
1126 memset(cmd->cmnd, 0, sizeof(cmd->cmnd));
1127 cmd->cmd_len = MAX_COMMAND_SIZE;
1129 init_rcu_head(&cmd->rcu);
1130 cmd->jiffies_at_alloc = jiffies;
1134 struct request *scsi_alloc_request(struct request_queue *q, blk_opf_t opf,
1135 blk_mq_req_flags_t flags)
1139 rq = blk_mq_alloc_request(q, opf, flags);
1141 scsi_initialize_rq(rq);
1144 EXPORT_SYMBOL_GPL(scsi_alloc_request);
1147 * Only called when the request isn't completed by SCSI, and not freed by
1150 static void scsi_cleanup_rq(struct request *rq)
1152 if (rq->rq_flags & RQF_DONTPREP) {
1153 scsi_mq_uninit_cmd(blk_mq_rq_to_pdu(rq));
1154 rq->rq_flags &= ~RQF_DONTPREP;
1158 /* Called before a request is prepared. See also scsi_mq_prep_fn(). */
1159 void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
1161 struct request *rq = scsi_cmd_to_rq(cmd);
1163 if (!blk_rq_is_passthrough(rq) && !(cmd->flags & SCMD_INITIALIZED)) {
1164 cmd->flags |= SCMD_INITIALIZED;
1165 scsi_initialize_rq(rq);
1169 INIT_LIST_HEAD(&cmd->eh_entry);
1170 INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
1173 static blk_status_t scsi_setup_scsi_cmnd(struct scsi_device *sdev,
1174 struct request *req)
1176 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
1179 * Passthrough requests may transfer data, in which case they must
1180 * a bio attached to them. Or they might contain a SCSI command
1181 * that does not transfer data, in which case they may optionally
1182 * submit a request without an attached bio.
1185 blk_status_t ret = scsi_alloc_sgtables(cmd);
1186 if (unlikely(ret != BLK_STS_OK))
1189 BUG_ON(blk_rq_bytes(req));
1191 memset(&cmd->sdb, 0, sizeof(cmd->sdb));
1194 cmd->transfersize = blk_rq_bytes(req);
1199 scsi_device_state_check(struct scsi_device *sdev, struct request *req)
1201 switch (sdev->sdev_state) {
1205 case SDEV_TRANSPORT_OFFLINE:
1207 * If the device is offline we refuse to process any
1208 * commands. The device must be brought online
1209 * before trying any recovery commands.
1211 if (!sdev->offline_already) {
1212 sdev->offline_already = true;
1213 sdev_printk(KERN_ERR, sdev,
1214 "rejecting I/O to offline device\n");
1216 return BLK_STS_IOERR;
1219 * If the device is fully deleted, we refuse to
1220 * process any commands as well.
1222 sdev_printk(KERN_ERR, sdev,
1223 "rejecting I/O to dead device\n");
1224 return BLK_STS_IOERR;
1226 case SDEV_CREATED_BLOCK:
1227 return BLK_STS_RESOURCE;
1230 * If the device is blocked we only accept power management
1233 if (req && WARN_ON_ONCE(!(req->rq_flags & RQF_PM)))
1234 return BLK_STS_RESOURCE;
1238 * For any other not fully online state we only allow
1239 * power management commands.
1241 if (req && !(req->rq_flags & RQF_PM))
1242 return BLK_STS_OFFLINE;
1248 * scsi_dev_queue_ready: if we can send requests to sdev, assign one token
1249 * and return the token else return -1.
1251 static inline int scsi_dev_queue_ready(struct request_queue *q,
1252 struct scsi_device *sdev)
1256 token = sbitmap_get(&sdev->budget_map);
1257 if (atomic_read(&sdev->device_blocked)) {
1261 if (scsi_device_busy(sdev) > 1)
1265 * unblock after device_blocked iterates to zero
1267 if (atomic_dec_return(&sdev->device_blocked) > 0)
1269 SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev,
1270 "unblocking device at zero depth\n"));
1276 sbitmap_put(&sdev->budget_map, token);
1282 * scsi_target_queue_ready: checks if there we can send commands to target
1283 * @sdev: scsi device on starget to check.
1285 static inline int scsi_target_queue_ready(struct Scsi_Host *shost,
1286 struct scsi_device *sdev)
1288 struct scsi_target *starget = scsi_target(sdev);
1291 if (starget->single_lun) {
1292 spin_lock_irq(shost->host_lock);
1293 if (starget->starget_sdev_user &&
1294 starget->starget_sdev_user != sdev) {
1295 spin_unlock_irq(shost->host_lock);
1298 starget->starget_sdev_user = sdev;
1299 spin_unlock_irq(shost->host_lock);
1302 if (starget->can_queue <= 0)
1305 busy = atomic_inc_return(&starget->target_busy) - 1;
1306 if (atomic_read(&starget->target_blocked) > 0) {
1311 * unblock after target_blocked iterates to zero
1313 if (atomic_dec_return(&starget->target_blocked) > 0)
1316 SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget,
1317 "unblocking target at zero depth\n"));
1320 if (busy >= starget->can_queue)
1326 spin_lock_irq(shost->host_lock);
1327 list_move_tail(&sdev->starved_entry, &shost->starved_list);
1328 spin_unlock_irq(shost->host_lock);
1330 if (starget->can_queue > 0)
1331 atomic_dec(&starget->target_busy);
1336 * scsi_host_queue_ready: if we can send requests to shost, return 1 else
1337 * return 0. We must end up running the queue again whenever 0 is
1338 * returned, else IO can hang.
1340 static inline int scsi_host_queue_ready(struct request_queue *q,
1341 struct Scsi_Host *shost,
1342 struct scsi_device *sdev,
1343 struct scsi_cmnd *cmd)
1345 if (atomic_read(&shost->host_blocked) > 0) {
1346 if (scsi_host_busy(shost) > 0)
1350 * unblock after host_blocked iterates to zero
1352 if (atomic_dec_return(&shost->host_blocked) > 0)
1356 shost_printk(KERN_INFO, shost,
1357 "unblocking host at zero depth\n"));
1360 if (shost->host_self_blocked)
1363 /* We're OK to process the command, so we can't be starved */
1364 if (!list_empty(&sdev->starved_entry)) {
1365 spin_lock_irq(shost->host_lock);
1366 if (!list_empty(&sdev->starved_entry))
1367 list_del_init(&sdev->starved_entry);
1368 spin_unlock_irq(shost->host_lock);
1371 __set_bit(SCMD_STATE_INFLIGHT, &cmd->state);
1376 spin_lock_irq(shost->host_lock);
1377 if (list_empty(&sdev->starved_entry))
1378 list_add_tail(&sdev->starved_entry, &shost->starved_list);
1379 spin_unlock_irq(shost->host_lock);
1381 scsi_dec_host_busy(shost, cmd);
1386 * Busy state exporting function for request stacking drivers.
1388 * For efficiency, no lock is taken to check the busy state of
1389 * shost/starget/sdev, since the returned value is not guaranteed and
1390 * may be changed after request stacking drivers call the function,
1391 * regardless of taking lock or not.
1393 * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi
1394 * needs to return 'not busy'. Otherwise, request stacking drivers
1395 * may hold requests forever.
1397 static bool scsi_mq_lld_busy(struct request_queue *q)
1399 struct scsi_device *sdev = q->queuedata;
1400 struct Scsi_Host *shost;
1402 if (blk_queue_dying(q))
1408 * Ignore host/starget busy state.
1409 * Since block layer does not have a concept of fairness across
1410 * multiple queues, congestion of host/starget needs to be handled
1413 if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev))
1420 * Block layer request completion callback. May be called from interrupt
1423 static void scsi_complete(struct request *rq)
1425 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
1426 enum scsi_disposition disposition;
1428 INIT_LIST_HEAD(&cmd->eh_entry);
1430 atomic_inc(&cmd->device->iodone_cnt);
1432 atomic_inc(&cmd->device->ioerr_cnt);
1434 disposition = scsi_decide_disposition(cmd);
1435 if (disposition != SUCCESS && scsi_cmd_runtime_exceeced(cmd))
1436 disposition = SUCCESS;
1438 scsi_log_completion(cmd, disposition);
1440 switch (disposition) {
1442 scsi_finish_command(cmd);
1445 scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY);
1447 case ADD_TO_MLQUEUE:
1448 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
1451 scsi_eh_scmd_add(cmd);
1457 * scsi_dispatch_cmd - Dispatch a command to the low-level driver.
1458 * @cmd: command block we are dispatching.
1460 * Return: nonzero return request was rejected and device's queue needs to be
1463 static int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
1465 struct Scsi_Host *host = cmd->device->host;
1468 atomic_inc(&cmd->device->iorequest_cnt);
1470 /* check if the device is still usable */
1471 if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
1472 /* in SDEV_DEL we error all commands. DID_NO_CONNECT
1473 * returns an immediate error upwards, and signals
1474 * that the device is no longer present */
1475 cmd->result = DID_NO_CONNECT << 16;
1479 /* Check to see if the scsi lld made this device blocked. */
1480 if (unlikely(scsi_device_blocked(cmd->device))) {
1482 * in blocked state, the command is just put back on
1483 * the device queue. The suspend state has already
1484 * blocked the queue so future requests should not
1485 * occur until the device transitions out of the
1488 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
1489 "queuecommand : device blocked\n"));
1490 atomic_dec(&cmd->device->iorequest_cnt);
1491 return SCSI_MLQUEUE_DEVICE_BUSY;
1494 /* Store the LUN value in cmnd, if needed. */
1495 if (cmd->device->lun_in_cdb)
1496 cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
1497 (cmd->device->lun << 5 & 0xe0);
1502 * Before we queue this command, check if the command
1503 * length exceeds what the host adapter can handle.
1505 if (cmd->cmd_len > cmd->device->host->max_cmd_len) {
1506 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
1507 "queuecommand : command too long. "
1508 "cdb_size=%d host->max_cmd_len=%d\n",
1509 cmd->cmd_len, cmd->device->host->max_cmd_len));
1510 cmd->result = (DID_ABORT << 16);
1514 if (unlikely(host->shost_state == SHOST_DEL)) {
1515 cmd->result = (DID_NO_CONNECT << 16);
1520 trace_scsi_dispatch_cmd_start(cmd);
1521 rtn = host->hostt->queuecommand(host, cmd);
1523 atomic_dec(&cmd->device->iorequest_cnt);
1524 trace_scsi_dispatch_cmd_error(cmd, rtn);
1525 if (rtn != SCSI_MLQUEUE_DEVICE_BUSY &&
1526 rtn != SCSI_MLQUEUE_TARGET_BUSY)
1527 rtn = SCSI_MLQUEUE_HOST_BUSY;
1529 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
1530 "queuecommand : request rejected\n"));
1539 /* Size in bytes of the sg-list stored in the scsi-mq command-private data. */
1540 static unsigned int scsi_mq_inline_sgl_size(struct Scsi_Host *shost)
1542 return min_t(unsigned int, shost->sg_tablesize, SCSI_INLINE_SG_CNT) *
1543 sizeof(struct scatterlist);
1546 static blk_status_t scsi_prepare_cmd(struct request *req)
1548 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
1549 struct scsi_device *sdev = req->q->queuedata;
1550 struct Scsi_Host *shost = sdev->host;
1551 bool in_flight = test_bit(SCMD_STATE_INFLIGHT, &cmd->state);
1552 struct scatterlist *sg;
1554 scsi_init_command(sdev, cmd);
1558 cmd->prot_flags = 0;
1560 memset(&cmd->sdb, 0, sizeof(cmd->sdb));
1562 cmd->transfersize = 0;
1563 cmd->host_scribble = NULL;
1568 __set_bit(SCMD_STATE_INFLIGHT, &cmd->state);
1571 * Only clear the driver-private command data if the LLD does not supply
1572 * a function to initialize that data.
1574 if (!shost->hostt->init_cmd_priv)
1575 memset(cmd + 1, 0, shost->hostt->cmd_size);
1577 cmd->prot_op = SCSI_PROT_NORMAL;
1578 if (blk_rq_bytes(req))
1579 cmd->sc_data_direction = rq_dma_dir(req);
1581 cmd->sc_data_direction = DMA_NONE;
1583 sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size;
1584 cmd->sdb.table.sgl = sg;
1586 if (scsi_host_get_prot(shost)) {
1587 memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer));
1589 cmd->prot_sdb->table.sgl =
1590 (struct scatterlist *)(cmd->prot_sdb + 1);
1594 * Special handling for passthrough commands, which don't go to the ULP
1597 if (blk_rq_is_passthrough(req))
1598 return scsi_setup_scsi_cmnd(sdev, req);
1600 if (sdev->handler && sdev->handler->prep_fn) {
1601 blk_status_t ret = sdev->handler->prep_fn(sdev, req);
1603 if (ret != BLK_STS_OK)
1607 /* Usually overridden by the ULP */
1609 memset(cmd->cmnd, 0, sizeof(cmd->cmnd));
1610 return scsi_cmd_to_driver(cmd)->init_command(cmd);
1613 static void scsi_done_internal(struct scsi_cmnd *cmd, bool complete_directly)
1615 struct request *req = scsi_cmd_to_rq(cmd);
1617 switch (cmd->submitter) {
1618 case SUBMITTED_BY_BLOCK_LAYER:
1620 case SUBMITTED_BY_SCSI_ERROR_HANDLER:
1621 return scsi_eh_done(cmd);
1622 case SUBMITTED_BY_SCSI_RESET_IOCTL:
1626 if (unlikely(blk_should_fake_timeout(scsi_cmd_to_rq(cmd)->q)))
1628 if (unlikely(test_and_set_bit(SCMD_STATE_COMPLETE, &cmd->state)))
1630 trace_scsi_dispatch_cmd_done(cmd);
1632 if (complete_directly)
1633 blk_mq_complete_request_direct(req, scsi_complete);
1635 blk_mq_complete_request(req);
1638 void scsi_done(struct scsi_cmnd *cmd)
1640 scsi_done_internal(cmd, false);
1642 EXPORT_SYMBOL(scsi_done);
1644 void scsi_done_direct(struct scsi_cmnd *cmd)
1646 scsi_done_internal(cmd, true);
1648 EXPORT_SYMBOL(scsi_done_direct);
1650 static void scsi_mq_put_budget(struct request_queue *q, int budget_token)
1652 struct scsi_device *sdev = q->queuedata;
1654 sbitmap_put(&sdev->budget_map, budget_token);
1658 * When to reinvoke queueing after a resource shortage. It's 3 msecs to
1659 * not change behaviour from the previous unplug mechanism, experimentation
1660 * may prove this needs changing.
1662 #define SCSI_QUEUE_DELAY 3
1664 static int scsi_mq_get_budget(struct request_queue *q)
1666 struct scsi_device *sdev = q->queuedata;
1667 int token = scsi_dev_queue_ready(q, sdev);
1672 atomic_inc(&sdev->restarts);
1675 * Orders atomic_inc(&sdev->restarts) and atomic_read(&sdev->device_busy).
1676 * .restarts must be incremented before .device_busy is read because the
1677 * code in scsi_run_queue_async() depends on the order of these operations.
1679 smp_mb__after_atomic();
1682 * If all in-flight requests originated from this LUN are completed
1683 * before reading .device_busy, sdev->device_busy will be observed as
1684 * zero, then blk_mq_delay_run_hw_queues() will dispatch this request
1685 * soon. Otherwise, completion of one of these requests will observe
1686 * the .restarts flag, and the request queue will be run for handling
1687 * this request, see scsi_end_request().
1689 if (unlikely(scsi_device_busy(sdev) == 0 &&
1690 !scsi_device_blocked(sdev)))
1691 blk_mq_delay_run_hw_queues(sdev->request_queue, SCSI_QUEUE_DELAY);
1695 static void scsi_mq_set_rq_budget_token(struct request *req, int token)
1697 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
1699 cmd->budget_token = token;
1702 static int scsi_mq_get_rq_budget_token(struct request *req)
1704 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
1706 return cmd->budget_token;
1709 static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
1710 const struct blk_mq_queue_data *bd)
1712 struct request *req = bd->rq;
1713 struct request_queue *q = req->q;
1714 struct scsi_device *sdev = q->queuedata;
1715 struct Scsi_Host *shost = sdev->host;
1716 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
1720 WARN_ON_ONCE(cmd->budget_token < 0);
1723 * If the device is not in running state we will reject some or all
1726 if (unlikely(sdev->sdev_state != SDEV_RUNNING)) {
1727 ret = scsi_device_state_check(sdev, req);
1728 if (ret != BLK_STS_OK)
1729 goto out_put_budget;
1732 ret = BLK_STS_RESOURCE;
1733 if (!scsi_target_queue_ready(shost, sdev))
1734 goto out_put_budget;
1735 if (unlikely(scsi_host_in_recovery(shost))) {
1736 if (cmd->flags & SCMD_FAIL_IF_RECOVERING)
1737 ret = BLK_STS_OFFLINE;
1738 goto out_dec_target_busy;
1740 if (!scsi_host_queue_ready(q, shost, sdev, cmd))
1741 goto out_dec_target_busy;
1743 if (!(req->rq_flags & RQF_DONTPREP)) {
1744 ret = scsi_prepare_cmd(req);
1745 if (ret != BLK_STS_OK)
1746 goto out_dec_host_busy;
1747 req->rq_flags |= RQF_DONTPREP;
1749 clear_bit(SCMD_STATE_COMPLETE, &cmd->state);
1752 cmd->flags &= SCMD_PRESERVED_FLAGS;
1753 if (sdev->simple_tags)
1754 cmd->flags |= SCMD_TAGGED;
1756 cmd->flags |= SCMD_LAST;
1758 scsi_set_resid(cmd, 0);
1759 memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
1760 cmd->submitter = SUBMITTED_BY_BLOCK_LAYER;
1762 blk_mq_start_request(req);
1763 reason = scsi_dispatch_cmd(cmd);
1765 scsi_set_blocked(cmd, reason);
1766 ret = BLK_STS_RESOURCE;
1767 goto out_dec_host_busy;
1773 scsi_dec_host_busy(shost, cmd);
1774 out_dec_target_busy:
1775 if (scsi_target(sdev)->can_queue > 0)
1776 atomic_dec(&scsi_target(sdev)->target_busy);
1778 scsi_mq_put_budget(q, cmd->budget_token);
1779 cmd->budget_token = -1;
1783 case BLK_STS_RESOURCE:
1784 case BLK_STS_ZONE_RESOURCE:
1785 if (scsi_device_blocked(sdev))
1786 ret = BLK_STS_DEV_RESOURCE;
1789 cmd->result = DID_BUS_BUSY << 16;
1790 if (req->rq_flags & RQF_DONTPREP)
1791 scsi_mq_uninit_cmd(cmd);
1794 if (unlikely(!scsi_device_online(sdev)))
1795 cmd->result = DID_NO_CONNECT << 16;
1797 cmd->result = DID_ERROR << 16;
1799 * Make sure to release all allocated resources when
1800 * we hit an error, as we will never see this command
1803 if (req->rq_flags & RQF_DONTPREP)
1804 scsi_mq_uninit_cmd(cmd);
1805 scsi_run_queue_async(sdev);
1811 static int scsi_mq_init_request(struct blk_mq_tag_set *set, struct request *rq,
1812 unsigned int hctx_idx, unsigned int numa_node)
1814 struct Scsi_Host *shost = set->driver_data;
1815 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
1816 struct scatterlist *sg;
1820 kmem_cache_alloc_node(scsi_sense_cache, GFP_KERNEL, numa_node);
1821 if (!cmd->sense_buffer)
1824 if (scsi_host_get_prot(shost)) {
1825 sg = (void *)cmd + sizeof(struct scsi_cmnd) +
1826 shost->hostt->cmd_size;
1827 cmd->prot_sdb = (void *)sg + scsi_mq_inline_sgl_size(shost);
1830 if (shost->hostt->init_cmd_priv) {
1831 ret = shost->hostt->init_cmd_priv(shost, cmd);
1833 kmem_cache_free(scsi_sense_cache, cmd->sense_buffer);
1839 static void scsi_mq_exit_request(struct blk_mq_tag_set *set, struct request *rq,
1840 unsigned int hctx_idx)
1842 struct Scsi_Host *shost = set->driver_data;
1843 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
1845 if (shost->hostt->exit_cmd_priv)
1846 shost->hostt->exit_cmd_priv(shost, cmd);
1847 kmem_cache_free(scsi_sense_cache, cmd->sense_buffer);
1851 static int scsi_mq_poll(struct blk_mq_hw_ctx *hctx, struct io_comp_batch *iob)
1853 struct Scsi_Host *shost = hctx->driver_data;
1855 if (shost->hostt->mq_poll)
1856 return shost->hostt->mq_poll(shost, hctx->queue_num);
1861 static int scsi_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
1862 unsigned int hctx_idx)
1864 struct Scsi_Host *shost = data;
1866 hctx->driver_data = shost;
1870 static void scsi_map_queues(struct blk_mq_tag_set *set)
1872 struct Scsi_Host *shost = container_of(set, struct Scsi_Host, tag_set);
1874 if (shost->hostt->map_queues)
1875 return shost->hostt->map_queues(shost);
1876 blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]);
1879 void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q)
1881 struct device *dev = shost->dma_dev;
1884 * this limit is imposed by hardware restrictions
1886 blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize,
1889 if (scsi_host_prot_dma(shost)) {
1890 shost->sg_prot_tablesize =
1891 min_not_zero(shost->sg_prot_tablesize,
1892 (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS);
1893 BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize);
1894 blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize);
1897 blk_queue_max_hw_sectors(q, shost->max_sectors);
1898 blk_queue_segment_boundary(q, shost->dma_boundary);
1899 dma_set_seg_boundary(dev, shost->dma_boundary);
1901 blk_queue_max_segment_size(q, shost->max_segment_size);
1902 blk_queue_virt_boundary(q, shost->virt_boundary_mask);
1903 dma_set_max_seg_size(dev, queue_max_segment_size(q));
1906 * Set a reasonable default alignment: The larger of 32-byte (dword),
1907 * which is a common minimum for HBAs, and the minimum DMA alignment,
1908 * which is set by the platform.
1910 * Devices that require a bigger alignment can increase it later.
1912 blk_queue_dma_alignment(q, max(4, dma_get_cache_alignment()) - 1);
1914 EXPORT_SYMBOL_GPL(__scsi_init_queue);
1916 static const struct blk_mq_ops scsi_mq_ops_no_commit = {
1917 .get_budget = scsi_mq_get_budget,
1918 .put_budget = scsi_mq_put_budget,
1919 .queue_rq = scsi_queue_rq,
1920 .complete = scsi_complete,
1921 .timeout = scsi_timeout,
1922 #ifdef CONFIG_BLK_DEBUG_FS
1923 .show_rq = scsi_show_rq,
1925 .init_request = scsi_mq_init_request,
1926 .exit_request = scsi_mq_exit_request,
1927 .cleanup_rq = scsi_cleanup_rq,
1928 .busy = scsi_mq_lld_busy,
1929 .map_queues = scsi_map_queues,
1930 .init_hctx = scsi_init_hctx,
1931 .poll = scsi_mq_poll,
1932 .set_rq_budget_token = scsi_mq_set_rq_budget_token,
1933 .get_rq_budget_token = scsi_mq_get_rq_budget_token,
1937 static void scsi_commit_rqs(struct blk_mq_hw_ctx *hctx)
1939 struct Scsi_Host *shost = hctx->driver_data;
1941 shost->hostt->commit_rqs(shost, hctx->queue_num);
1944 static const struct blk_mq_ops scsi_mq_ops = {
1945 .get_budget = scsi_mq_get_budget,
1946 .put_budget = scsi_mq_put_budget,
1947 .queue_rq = scsi_queue_rq,
1948 .commit_rqs = scsi_commit_rqs,
1949 .complete = scsi_complete,
1950 .timeout = scsi_timeout,
1951 #ifdef CONFIG_BLK_DEBUG_FS
1952 .show_rq = scsi_show_rq,
1954 .init_request = scsi_mq_init_request,
1955 .exit_request = scsi_mq_exit_request,
1956 .cleanup_rq = scsi_cleanup_rq,
1957 .busy = scsi_mq_lld_busy,
1958 .map_queues = scsi_map_queues,
1959 .init_hctx = scsi_init_hctx,
1960 .poll = scsi_mq_poll,
1961 .set_rq_budget_token = scsi_mq_set_rq_budget_token,
1962 .get_rq_budget_token = scsi_mq_get_rq_budget_token,
1965 int scsi_mq_setup_tags(struct Scsi_Host *shost)
1967 unsigned int cmd_size, sgl_size;
1968 struct blk_mq_tag_set *tag_set = &shost->tag_set;
1970 sgl_size = max_t(unsigned int, sizeof(struct scatterlist),
1971 scsi_mq_inline_sgl_size(shost));
1972 cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size + sgl_size;
1973 if (scsi_host_get_prot(shost))
1974 cmd_size += sizeof(struct scsi_data_buffer) +
1975 sizeof(struct scatterlist) * SCSI_INLINE_PROT_SG_CNT;
1977 memset(tag_set, 0, sizeof(*tag_set));
1978 if (shost->hostt->commit_rqs)
1979 tag_set->ops = &scsi_mq_ops;
1981 tag_set->ops = &scsi_mq_ops_no_commit;
1982 tag_set->nr_hw_queues = shost->nr_hw_queues ? : 1;
1983 tag_set->nr_maps = shost->nr_maps ? : 1;
1984 tag_set->queue_depth = shost->can_queue;
1985 tag_set->cmd_size = cmd_size;
1986 tag_set->numa_node = dev_to_node(shost->dma_dev);
1987 tag_set->flags = BLK_MQ_F_SHOULD_MERGE;
1989 BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy);
1990 if (shost->queuecommand_may_block)
1991 tag_set->flags |= BLK_MQ_F_BLOCKING;
1992 tag_set->driver_data = shost;
1993 if (shost->host_tagset)
1994 tag_set->flags |= BLK_MQ_F_TAG_HCTX_SHARED;
1996 return blk_mq_alloc_tag_set(tag_set);
1999 void scsi_mq_free_tags(struct kref *kref)
2001 struct Scsi_Host *shost = container_of(kref, typeof(*shost),
2004 blk_mq_free_tag_set(&shost->tag_set);
2005 complete(&shost->tagset_freed);
2009 * scsi_device_from_queue - return sdev associated with a request_queue
2010 * @q: The request queue to return the sdev from
2012 * Return the sdev associated with a request queue or NULL if the
2013 * request_queue does not reference a SCSI device.
2015 struct scsi_device *scsi_device_from_queue(struct request_queue *q)
2017 struct scsi_device *sdev = NULL;
2019 if (q->mq_ops == &scsi_mq_ops_no_commit ||
2020 q->mq_ops == &scsi_mq_ops)
2021 sdev = q->queuedata;
2022 if (!sdev || !get_device(&sdev->sdev_gendev))
2028 * pktcdvd should have been integrated into the SCSI layers, but for historical
2029 * reasons like the old IDE driver it isn't. This export allows it to safely
2030 * probe if a given device is a SCSI one and only attach to that.
2032 #ifdef CONFIG_CDROM_PKTCDVD_MODULE
2033 EXPORT_SYMBOL_GPL(scsi_device_from_queue);
2037 * scsi_block_requests - Utility function used by low-level drivers to prevent
2038 * further commands from being queued to the device.
2039 * @shost: host in question
2041 * There is no timer nor any other means by which the requests get unblocked
2042 * other than the low-level driver calling scsi_unblock_requests().
2044 void scsi_block_requests(struct Scsi_Host *shost)
2046 shost->host_self_blocked = 1;
2048 EXPORT_SYMBOL(scsi_block_requests);
2051 * scsi_unblock_requests - Utility function used by low-level drivers to allow
2052 * further commands to be queued to the device.
2053 * @shost: host in question
2055 * There is no timer nor any other means by which the requests get unblocked
2056 * other than the low-level driver calling scsi_unblock_requests(). This is done
2057 * as an API function so that changes to the internals of the scsi mid-layer
2058 * won't require wholesale changes to drivers that use this feature.
2060 void scsi_unblock_requests(struct Scsi_Host *shost)
2062 shost->host_self_blocked = 0;
2063 scsi_run_host_queues(shost);
2065 EXPORT_SYMBOL(scsi_unblock_requests);
2067 void scsi_exit_queue(void)
2069 kmem_cache_destroy(scsi_sense_cache);
2073 * scsi_mode_select - issue a mode select
2074 * @sdev: SCSI device to be queried
2075 * @pf: Page format bit (1 == standard, 0 == vendor specific)
2076 * @sp: Save page bit (0 == don't save, 1 == save)
2077 * @buffer: request buffer (may not be smaller than eight bytes)
2078 * @len: length of request buffer.
2079 * @timeout: command timeout
2080 * @retries: number of retries before failing
2081 * @data: returns a structure abstracting the mode header data
2082 * @sshdr: place to put sense data (or NULL if no sense to be collected).
2083 * must be SCSI_SENSE_BUFFERSIZE big.
2085 * Returns zero if successful; negative error number or scsi
2089 int scsi_mode_select(struct scsi_device *sdev, int pf, int sp,
2090 unsigned char *buffer, int len, int timeout, int retries,
2091 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
2093 unsigned char cmd[10];
2094 unsigned char *real_buffer;
2095 const struct scsi_exec_args exec_args = {
2100 memset(cmd, 0, sizeof(cmd));
2101 cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0);
2104 * Use MODE SELECT(10) if the device asked for it or if the mode page
2105 * and the mode select header cannot fit within the maximumm 255 bytes
2106 * of the MODE SELECT(6) command.
2108 if (sdev->use_10_for_ms ||
2110 data->block_descriptor_length > 255) {
2111 if (len > 65535 - 8)
2113 real_buffer = kmalloc(8 + len, GFP_KERNEL);
2116 memcpy(real_buffer + 8, buffer, len);
2120 real_buffer[2] = data->medium_type;
2121 real_buffer[3] = data->device_specific;
2122 real_buffer[4] = data->longlba ? 0x01 : 0;
2124 put_unaligned_be16(data->block_descriptor_length,
2127 cmd[0] = MODE_SELECT_10;
2128 put_unaligned_be16(len, &cmd[7]);
2133 real_buffer = kmalloc(4 + len, GFP_KERNEL);
2136 memcpy(real_buffer + 4, buffer, len);
2139 real_buffer[1] = data->medium_type;
2140 real_buffer[2] = data->device_specific;
2141 real_buffer[3] = data->block_descriptor_length;
2143 cmd[0] = MODE_SELECT;
2147 ret = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_OUT, real_buffer, len,
2148 timeout, retries, &exec_args);
2152 EXPORT_SYMBOL_GPL(scsi_mode_select);
2155 * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary.
2156 * @sdev: SCSI device to be queried
2157 * @dbd: set to prevent mode sense from returning block descriptors
2158 * @modepage: mode page being requested
2159 * @subpage: sub-page of the mode page being requested
2160 * @buffer: request buffer (may not be smaller than eight bytes)
2161 * @len: length of request buffer.
2162 * @timeout: command timeout
2163 * @retries: number of retries before failing
2164 * @data: returns a structure abstracting the mode header data
2165 * @sshdr: place to put sense data (or NULL if no sense to be collected).
2166 * must be SCSI_SENSE_BUFFERSIZE big.
2168 * Returns zero if successful, or a negative error number on failure
2171 scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, int subpage,
2172 unsigned char *buffer, int len, int timeout, int retries,
2173 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
2175 unsigned char cmd[12];
2178 int result, retry_count = retries;
2179 struct scsi_sense_hdr my_sshdr;
2180 const struct scsi_exec_args exec_args = {
2181 /* caller might not be interested in sense, but we need it */
2182 .sshdr = sshdr ? : &my_sshdr,
2185 memset(data, 0, sizeof(*data));
2186 memset(&cmd[0], 0, 12);
2188 dbd = sdev->set_dbd_for_ms ? 8 : dbd;
2189 cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */
2193 sshdr = exec_args.sshdr;
2196 use_10_for_ms = sdev->use_10_for_ms || len > 255;
2198 if (use_10_for_ms) {
2199 if (len < 8 || len > 65535)
2202 cmd[0] = MODE_SENSE_10;
2203 put_unaligned_be16(len, &cmd[7]);
2209 cmd[0] = MODE_SENSE;
2214 memset(buffer, 0, len);
2216 result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, buffer, len,
2217 timeout, retries, &exec_args);
2221 /* This code looks awful: what it's doing is making sure an
2222 * ILLEGAL REQUEST sense return identifies the actual command
2223 * byte as the problem. MODE_SENSE commands can return
2224 * ILLEGAL REQUEST if the code page isn't supported */
2226 if (!scsi_status_is_good(result)) {
2227 if (scsi_sense_valid(sshdr)) {
2228 if ((sshdr->sense_key == ILLEGAL_REQUEST) &&
2229 (sshdr->asc == 0x20) && (sshdr->ascq == 0)) {
2231 * Invalid command operation code: retry using
2232 * MODE SENSE(6) if this was a MODE SENSE(10)
2233 * request, except if the request mode page is
2234 * too large for MODE SENSE single byte
2235 * allocation length field.
2237 if (use_10_for_ms) {
2240 sdev->use_10_for_ms = 0;
2244 if (scsi_status_is_check_condition(result) &&
2245 sshdr->sense_key == UNIT_ATTENTION &&
2253 if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b &&
2254 (modepage == 6 || modepage == 8))) {
2255 /* Initio breakage? */
2258 data->medium_type = 0;
2259 data->device_specific = 0;
2261 data->block_descriptor_length = 0;
2262 } else if (use_10_for_ms) {
2263 data->length = get_unaligned_be16(&buffer[0]) + 2;
2264 data->medium_type = buffer[2];
2265 data->device_specific = buffer[3];
2266 data->longlba = buffer[4] & 0x01;
2267 data->block_descriptor_length = get_unaligned_be16(&buffer[6]);
2269 data->length = buffer[0] + 1;
2270 data->medium_type = buffer[1];
2271 data->device_specific = buffer[2];
2272 data->block_descriptor_length = buffer[3];
2274 data->header_length = header_length;
2278 EXPORT_SYMBOL(scsi_mode_sense);
2281 * scsi_test_unit_ready - test if unit is ready
2282 * @sdev: scsi device to change the state of.
2283 * @timeout: command timeout
2284 * @retries: number of retries before failing
2285 * @sshdr: outpout pointer for decoded sense information.
2287 * Returns zero if unsuccessful or an error if TUR failed. For
2288 * removable media, UNIT_ATTENTION sets ->changed flag.
2291 scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries,
2292 struct scsi_sense_hdr *sshdr)
2295 TEST_UNIT_READY, 0, 0, 0, 0, 0,
2297 const struct scsi_exec_args exec_args = {
2302 /* try to eat the UNIT_ATTENTION if there are enough retries */
2304 result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, NULL, 0,
2305 timeout, 1, &exec_args);
2306 if (sdev->removable && scsi_sense_valid(sshdr) &&
2307 sshdr->sense_key == UNIT_ATTENTION)
2309 } while (scsi_sense_valid(sshdr) &&
2310 sshdr->sense_key == UNIT_ATTENTION && --retries);
2314 EXPORT_SYMBOL(scsi_test_unit_ready);
2317 * scsi_device_set_state - Take the given device through the device state model.
2318 * @sdev: scsi device to change the state of.
2319 * @state: state to change to.
2321 * Returns zero if successful or an error if the requested
2322 * transition is illegal.
2325 scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
2327 enum scsi_device_state oldstate = sdev->sdev_state;
2329 if (state == oldstate)
2335 case SDEV_CREATED_BLOCK:
2346 case SDEV_TRANSPORT_OFFLINE:
2359 case SDEV_TRANSPORT_OFFLINE:
2367 case SDEV_TRANSPORT_OFFLINE:
2382 case SDEV_CREATED_BLOCK:
2391 case SDEV_CREATED_BLOCK:
2406 case SDEV_TRANSPORT_OFFLINE:
2418 case SDEV_TRANSPORT_OFFLINE:
2421 case SDEV_CREATED_BLOCK:
2429 sdev->offline_already = false;
2430 sdev->sdev_state = state;
2434 SCSI_LOG_ERROR_RECOVERY(1,
2435 sdev_printk(KERN_ERR, sdev,
2436 "Illegal state transition %s->%s",
2437 scsi_device_state_name(oldstate),
2438 scsi_device_state_name(state))
2442 EXPORT_SYMBOL(scsi_device_set_state);
2445 * scsi_evt_emit - emit a single SCSI device uevent
2446 * @sdev: associated SCSI device
2447 * @evt: event to emit
2449 * Send a single uevent (scsi_event) to the associated scsi_device.
2451 static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt)
2456 switch (evt->evt_type) {
2457 case SDEV_EVT_MEDIA_CHANGE:
2458 envp[idx++] = "SDEV_MEDIA_CHANGE=1";
2460 case SDEV_EVT_INQUIRY_CHANGE_REPORTED:
2461 scsi_rescan_device(&sdev->sdev_gendev);
2462 envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED";
2464 case SDEV_EVT_CAPACITY_CHANGE_REPORTED:
2465 envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED";
2467 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED:
2468 envp[idx++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED";
2470 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED:
2471 envp[idx++] = "SDEV_UA=MODE_PARAMETERS_CHANGED";
2473 case SDEV_EVT_LUN_CHANGE_REPORTED:
2474 envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED";
2476 case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED:
2477 envp[idx++] = "SDEV_UA=ASYMMETRIC_ACCESS_STATE_CHANGED";
2479 case SDEV_EVT_POWER_ON_RESET_OCCURRED:
2480 envp[idx++] = "SDEV_UA=POWER_ON_RESET_OCCURRED";
2489 kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp);
2493 * scsi_evt_thread - send a uevent for each scsi event
2494 * @work: work struct for scsi_device
2496 * Dispatch queued events to their associated scsi_device kobjects
2499 void scsi_evt_thread(struct work_struct *work)
2501 struct scsi_device *sdev;
2502 enum scsi_device_event evt_type;
2503 LIST_HEAD(event_list);
2505 sdev = container_of(work, struct scsi_device, event_work);
2507 for (evt_type = SDEV_EVT_FIRST; evt_type <= SDEV_EVT_LAST; evt_type++)
2508 if (test_and_clear_bit(evt_type, sdev->pending_events))
2509 sdev_evt_send_simple(sdev, evt_type, GFP_KERNEL);
2512 struct scsi_event *evt;
2513 struct list_head *this, *tmp;
2514 unsigned long flags;
2516 spin_lock_irqsave(&sdev->list_lock, flags);
2517 list_splice_init(&sdev->event_list, &event_list);
2518 spin_unlock_irqrestore(&sdev->list_lock, flags);
2520 if (list_empty(&event_list))
2523 list_for_each_safe(this, tmp, &event_list) {
2524 evt = list_entry(this, struct scsi_event, node);
2525 list_del(&evt->node);
2526 scsi_evt_emit(sdev, evt);
2533 * sdev_evt_send - send asserted event to uevent thread
2534 * @sdev: scsi_device event occurred on
2535 * @evt: event to send
2537 * Assert scsi device event asynchronously.
2539 void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt)
2541 unsigned long flags;
2544 /* FIXME: currently this check eliminates all media change events
2545 * for polled devices. Need to update to discriminate between AN
2546 * and polled events */
2547 if (!test_bit(evt->evt_type, sdev->supported_events)) {
2553 spin_lock_irqsave(&sdev->list_lock, flags);
2554 list_add_tail(&evt->node, &sdev->event_list);
2555 schedule_work(&sdev->event_work);
2556 spin_unlock_irqrestore(&sdev->list_lock, flags);
2558 EXPORT_SYMBOL_GPL(sdev_evt_send);
2561 * sdev_evt_alloc - allocate a new scsi event
2562 * @evt_type: type of event to allocate
2563 * @gfpflags: GFP flags for allocation
2565 * Allocates and returns a new scsi_event.
2567 struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type,
2570 struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags);
2574 evt->evt_type = evt_type;
2575 INIT_LIST_HEAD(&evt->node);
2577 /* evt_type-specific initialization, if any */
2579 case SDEV_EVT_MEDIA_CHANGE:
2580 case SDEV_EVT_INQUIRY_CHANGE_REPORTED:
2581 case SDEV_EVT_CAPACITY_CHANGE_REPORTED:
2582 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED:
2583 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED:
2584 case SDEV_EVT_LUN_CHANGE_REPORTED:
2585 case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED:
2586 case SDEV_EVT_POWER_ON_RESET_OCCURRED:
2594 EXPORT_SYMBOL_GPL(sdev_evt_alloc);
2597 * sdev_evt_send_simple - send asserted event to uevent thread
2598 * @sdev: scsi_device event occurred on
2599 * @evt_type: type of event to send
2600 * @gfpflags: GFP flags for allocation
2602 * Assert scsi device event asynchronously, given an event type.
2604 void sdev_evt_send_simple(struct scsi_device *sdev,
2605 enum scsi_device_event evt_type, gfp_t gfpflags)
2607 struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags);
2609 sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n",
2614 sdev_evt_send(sdev, evt);
2616 EXPORT_SYMBOL_GPL(sdev_evt_send_simple);
2619 * scsi_device_quiesce - Block all commands except power management.
2620 * @sdev: scsi device to quiesce.
2622 * This works by trying to transition to the SDEV_QUIESCE state
2623 * (which must be a legal transition). When the device is in this
2624 * state, only power management requests will be accepted, all others will
2627 * Must be called with user context, may sleep.
2629 * Returns zero if unsuccessful or an error if not.
2632 scsi_device_quiesce(struct scsi_device *sdev)
2634 struct request_queue *q = sdev->request_queue;
2638 * It is allowed to call scsi_device_quiesce() multiple times from
2639 * the same context but concurrent scsi_device_quiesce() calls are
2642 WARN_ON_ONCE(sdev->quiesced_by && sdev->quiesced_by != current);
2644 if (sdev->quiesced_by == current)
2649 blk_mq_freeze_queue(q);
2651 * Ensure that the effect of blk_set_pm_only() will be visible
2652 * for percpu_ref_tryget() callers that occur after the queue
2653 * unfreeze even if the queue was already frozen before this function
2654 * was called. See also https://lwn.net/Articles/573497/.
2657 blk_mq_unfreeze_queue(q);
2659 mutex_lock(&sdev->state_mutex);
2660 err = scsi_device_set_state(sdev, SDEV_QUIESCE);
2662 sdev->quiesced_by = current;
2664 blk_clear_pm_only(q);
2665 mutex_unlock(&sdev->state_mutex);
2669 EXPORT_SYMBOL(scsi_device_quiesce);
2672 * scsi_device_resume - Restart user issued commands to a quiesced device.
2673 * @sdev: scsi device to resume.
2675 * Moves the device from quiesced back to running and restarts the
2678 * Must be called with user context, may sleep.
2680 void scsi_device_resume(struct scsi_device *sdev)
2682 /* check if the device state was mutated prior to resume, and if
2683 * so assume the state is being managed elsewhere (for example
2684 * device deleted during suspend)
2686 mutex_lock(&sdev->state_mutex);
2687 if (sdev->sdev_state == SDEV_QUIESCE)
2688 scsi_device_set_state(sdev, SDEV_RUNNING);
2689 if (sdev->quiesced_by) {
2690 sdev->quiesced_by = NULL;
2691 blk_clear_pm_only(sdev->request_queue);
2693 mutex_unlock(&sdev->state_mutex);
2695 EXPORT_SYMBOL(scsi_device_resume);
2698 device_quiesce_fn(struct scsi_device *sdev, void *data)
2700 scsi_device_quiesce(sdev);
2704 scsi_target_quiesce(struct scsi_target *starget)
2706 starget_for_each_device(starget, NULL, device_quiesce_fn);
2708 EXPORT_SYMBOL(scsi_target_quiesce);
2711 device_resume_fn(struct scsi_device *sdev, void *data)
2713 scsi_device_resume(sdev);
2717 scsi_target_resume(struct scsi_target *starget)
2719 starget_for_each_device(starget, NULL, device_resume_fn);
2721 EXPORT_SYMBOL(scsi_target_resume);
2723 static int __scsi_internal_device_block_nowait(struct scsi_device *sdev)
2725 if (scsi_device_set_state(sdev, SDEV_BLOCK))
2726 return scsi_device_set_state(sdev, SDEV_CREATED_BLOCK);
2731 void scsi_start_queue(struct scsi_device *sdev)
2733 if (cmpxchg(&sdev->queue_stopped, 1, 0))
2734 blk_mq_unquiesce_queue(sdev->request_queue);
2737 static void scsi_stop_queue(struct scsi_device *sdev)
2740 * The atomic variable of ->queue_stopped covers that
2741 * blk_mq_quiesce_queue* is balanced with blk_mq_unquiesce_queue.
2743 * The caller needs to wait until quiesce is done.
2745 if (!cmpxchg(&sdev->queue_stopped, 0, 1))
2746 blk_mq_quiesce_queue_nowait(sdev->request_queue);
2750 * scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state
2751 * @sdev: device to block
2753 * Pause SCSI command processing on the specified device. Does not sleep.
2755 * Returns zero if successful or a negative error code upon failure.
2758 * This routine transitions the device to the SDEV_BLOCK state (which must be
2759 * a legal transition). When the device is in this state, command processing
2760 * is paused until the device leaves the SDEV_BLOCK state. See also
2761 * scsi_internal_device_unblock_nowait().
2763 int scsi_internal_device_block_nowait(struct scsi_device *sdev)
2765 int ret = __scsi_internal_device_block_nowait(sdev);
2768 * The device has transitioned to SDEV_BLOCK. Stop the
2769 * block layer from calling the midlayer with this device's
2773 scsi_stop_queue(sdev);
2776 EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait);
2779 * scsi_device_block - try to transition to the SDEV_BLOCK state
2780 * @sdev: device to block
2781 * @data: dummy argument, ignored
2783 * Pause SCSI command processing on the specified device. Callers must wait
2784 * until all ongoing scsi_queue_rq() calls have finished after this function
2788 * This routine transitions the device to the SDEV_BLOCK state (which must be
2789 * a legal transition). When the device is in this state, command processing
2790 * is paused until the device leaves the SDEV_BLOCK state. See also
2791 * scsi_internal_device_unblock().
2793 static void scsi_device_block(struct scsi_device *sdev, void *data)
2796 enum scsi_device_state state;
2798 mutex_lock(&sdev->state_mutex);
2799 err = __scsi_internal_device_block_nowait(sdev);
2800 state = sdev->sdev_state;
2803 * scsi_stop_queue() must be called with the state_mutex
2804 * held. Otherwise a simultaneous scsi_start_queue() call
2805 * might unquiesce the queue before we quiesce it.
2807 scsi_stop_queue(sdev);
2809 mutex_unlock(&sdev->state_mutex);
2811 WARN_ONCE(err, "%s: failed to block %s in state %d\n",
2812 __func__, dev_name(&sdev->sdev_gendev), state);
2816 * scsi_internal_device_unblock_nowait - resume a device after a block request
2817 * @sdev: device to resume
2818 * @new_state: state to set the device to after unblocking
2820 * Restart the device queue for a previously suspended SCSI device. Does not
2823 * Returns zero if successful or a negative error code upon failure.
2826 * This routine transitions the device to the SDEV_RUNNING state or to one of
2827 * the offline states (which must be a legal transition) allowing the midlayer
2828 * to goose the queue for this device.
2830 int scsi_internal_device_unblock_nowait(struct scsi_device *sdev,
2831 enum scsi_device_state new_state)
2833 switch (new_state) {
2835 case SDEV_TRANSPORT_OFFLINE:
2842 * Try to transition the scsi device to SDEV_RUNNING or one of the
2843 * offlined states and goose the device queue if successful.
2845 switch (sdev->sdev_state) {
2847 case SDEV_TRANSPORT_OFFLINE:
2848 sdev->sdev_state = new_state;
2850 case SDEV_CREATED_BLOCK:
2851 if (new_state == SDEV_TRANSPORT_OFFLINE ||
2852 new_state == SDEV_OFFLINE)
2853 sdev->sdev_state = new_state;
2855 sdev->sdev_state = SDEV_CREATED;
2863 scsi_start_queue(sdev);
2867 EXPORT_SYMBOL_GPL(scsi_internal_device_unblock_nowait);
2870 * scsi_internal_device_unblock - resume a device after a block request
2871 * @sdev: device to resume
2872 * @new_state: state to set the device to after unblocking
2874 * Restart the device queue for a previously suspended SCSI device. May sleep.
2876 * Returns zero if successful or a negative error code upon failure.
2879 * This routine transitions the device to the SDEV_RUNNING state or to one of
2880 * the offline states (which must be a legal transition) allowing the midlayer
2881 * to goose the queue for this device.
2883 static int scsi_internal_device_unblock(struct scsi_device *sdev,
2884 enum scsi_device_state new_state)
2888 mutex_lock(&sdev->state_mutex);
2889 ret = scsi_internal_device_unblock_nowait(sdev, new_state);
2890 mutex_unlock(&sdev->state_mutex);
2896 target_block(struct device *dev, void *data)
2898 if (scsi_is_target_device(dev))
2899 starget_for_each_device(to_scsi_target(dev), NULL,
2905 * scsi_block_targets - transition all SCSI child devices to SDEV_BLOCK state
2906 * @dev: a parent device of one or more scsi_target devices
2907 * @shost: the Scsi_Host to which this device belongs
2909 * Iterate over all children of @dev, which should be scsi_target devices,
2910 * and switch all subordinate scsi devices to SDEV_BLOCK state. Wait for
2911 * ongoing scsi_queue_rq() calls to finish. May sleep.
2914 * @dev must not itself be a scsi_target device.
2917 scsi_block_targets(struct Scsi_Host *shost, struct device *dev)
2919 WARN_ON_ONCE(scsi_is_target_device(dev));
2920 device_for_each_child(dev, NULL, target_block);
2921 blk_mq_wait_quiesce_done(&shost->tag_set);
2923 EXPORT_SYMBOL_GPL(scsi_block_targets);
2926 device_unblock(struct scsi_device *sdev, void *data)
2928 scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data);
2932 target_unblock(struct device *dev, void *data)
2934 if (scsi_is_target_device(dev))
2935 starget_for_each_device(to_scsi_target(dev), data,
2941 scsi_target_unblock(struct device *dev, enum scsi_device_state new_state)
2943 if (scsi_is_target_device(dev))
2944 starget_for_each_device(to_scsi_target(dev), &new_state,
2947 device_for_each_child(dev, &new_state, target_unblock);
2949 EXPORT_SYMBOL_GPL(scsi_target_unblock);
2952 * scsi_host_block - Try to transition all logical units to the SDEV_BLOCK state
2953 * @shost: device to block
2955 * Pause SCSI command processing for all logical units associated with the SCSI
2956 * host and wait until pending scsi_queue_rq() calls have finished.
2958 * Returns zero if successful or a negative error code upon failure.
2961 scsi_host_block(struct Scsi_Host *shost)
2963 struct scsi_device *sdev;
2967 * Call scsi_internal_device_block_nowait so we can avoid
2968 * calling synchronize_rcu() for each LUN.
2970 shost_for_each_device(sdev, shost) {
2971 mutex_lock(&sdev->state_mutex);
2972 ret = scsi_internal_device_block_nowait(sdev);
2973 mutex_unlock(&sdev->state_mutex);
2975 scsi_device_put(sdev);
2980 /* Wait for ongoing scsi_queue_rq() calls to finish. */
2981 blk_mq_wait_quiesce_done(&shost->tag_set);
2985 EXPORT_SYMBOL_GPL(scsi_host_block);
2988 scsi_host_unblock(struct Scsi_Host *shost, int new_state)
2990 struct scsi_device *sdev;
2993 shost_for_each_device(sdev, shost) {
2994 ret = scsi_internal_device_unblock(sdev, new_state);
2996 scsi_device_put(sdev);
3002 EXPORT_SYMBOL_GPL(scsi_host_unblock);
3005 * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt
3006 * @sgl: scatter-gather list
3007 * @sg_count: number of segments in sg
3008 * @offset: offset in bytes into sg, on return offset into the mapped area
3009 * @len: bytes to map, on return number of bytes mapped
3011 * Returns virtual address of the start of the mapped page
3013 void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count,
3014 size_t *offset, size_t *len)
3017 size_t sg_len = 0, len_complete = 0;
3018 struct scatterlist *sg;
3021 WARN_ON(!irqs_disabled());
3023 for_each_sg(sgl, sg, sg_count, i) {
3024 len_complete = sg_len; /* Complete sg-entries */
3025 sg_len += sg->length;
3026 if (sg_len > *offset)
3030 if (unlikely(i == sg_count)) {
3031 printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, "
3033 __func__, sg_len, *offset, sg_count);
3038 /* Offset starting from the beginning of first page in this sg-entry */
3039 *offset = *offset - len_complete + sg->offset;
3041 /* Assumption: contiguous pages can be accessed as "page + i" */
3042 page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT));
3043 *offset &= ~PAGE_MASK;
3045 /* Bytes in this sg-entry from *offset to the end of the page */
3046 sg_len = PAGE_SIZE - *offset;
3050 return kmap_atomic(page);
3052 EXPORT_SYMBOL(scsi_kmap_atomic_sg);
3055 * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg
3056 * @virt: virtual address to be unmapped
3058 void scsi_kunmap_atomic_sg(void *virt)
3060 kunmap_atomic(virt);
3062 EXPORT_SYMBOL(scsi_kunmap_atomic_sg);
3064 void sdev_disable_disk_events(struct scsi_device *sdev)
3066 atomic_inc(&sdev->disk_events_disable_depth);
3068 EXPORT_SYMBOL(sdev_disable_disk_events);
3070 void sdev_enable_disk_events(struct scsi_device *sdev)
3072 if (WARN_ON_ONCE(atomic_read(&sdev->disk_events_disable_depth) <= 0))
3074 atomic_dec(&sdev->disk_events_disable_depth);
3076 EXPORT_SYMBOL(sdev_enable_disk_events);
3078 static unsigned char designator_prio(const unsigned char *d)
3081 /* not associated with LUN */
3085 /* invalid length */
3089 * Order of preference for lun descriptor:
3090 * - SCSI name string
3091 * - NAA IEEE Registered Extended
3092 * - EUI-64 based 16-byte
3093 * - EUI-64 based 12-byte
3094 * - NAA IEEE Registered
3095 * - NAA IEEE Extended
3096 * - EUI-64 based 8-byte
3097 * - SCSI name string (truncated)
3099 * as longer descriptors reduce the likelyhood
3100 * of identification clashes.
3103 switch (d[1] & 0xf) {
3105 /* SCSI name string, variable-length UTF-8 */
3108 switch (d[4] >> 4) {
3110 /* NAA registered extended */
3113 /* NAA registered */
3119 /* NAA locally assigned */
3128 /* EUI64-based, 16 byte */
3131 /* EUI64-based, 12 byte */
3134 /* EUI64-based, 8 byte */
3151 * scsi_vpd_lun_id - return a unique device identification
3152 * @sdev: SCSI device
3153 * @id: buffer for the identification
3154 * @id_len: length of the buffer
3156 * Copies a unique device identification into @id based
3157 * on the information in the VPD page 0x83 of the device.
3158 * The string will be formatted as a SCSI name string.
3160 * Returns the length of the identification or error on failure.
3161 * If the identifier is longer than the supplied buffer the actual
3162 * identifier length is returned and the buffer is not zero-padded.
3164 int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len)
3168 const unsigned char *d, *cur_id_str;
3169 const struct scsi_vpd *vpd_pg83;
3170 int id_size = -EINVAL;
3173 vpd_pg83 = rcu_dereference(sdev->vpd_pg83);
3179 /* The id string must be at least 20 bytes + terminating NULL byte */
3185 memset(id, 0, id_len);
3186 for (d = vpd_pg83->data + 4;
3187 d < vpd_pg83->data + vpd_pg83->len;
3189 u8 prio = designator_prio(d);
3191 if (prio == 0 || cur_id_prio > prio)
3194 switch (d[1] & 0xf) {
3197 if (cur_id_size > d[3])
3201 if (cur_id_size + 4 > id_len)
3202 cur_id_size = id_len - 4;
3204 id_size = snprintf(id, id_len, "t10.%*pE",
3205 cur_id_size, cur_id_str);
3212 switch (cur_id_size) {
3214 id_size = snprintf(id, id_len,
3219 id_size = snprintf(id, id_len,
3224 id_size = snprintf(id, id_len,
3237 switch (cur_id_size) {
3239 id_size = snprintf(id, id_len,
3244 id_size = snprintf(id, id_len,
3253 /* SCSI name string */
3254 if (cur_id_size > d[3])
3256 /* Prefer others for truncated descriptor */
3257 if (d[3] > id_len) {
3259 if (cur_id_prio > prio)
3263 cur_id_size = id_size = d[3];
3265 if (cur_id_size >= id_len)
3266 cur_id_size = id_len - 1;
3267 memcpy(id, cur_id_str, cur_id_size);
3277 EXPORT_SYMBOL(scsi_vpd_lun_id);
3280 * scsi_vpd_tpg_id - return a target port group identifier
3281 * @sdev: SCSI device
3283 * Returns the Target Port Group identifier from the information
3284 * froom VPD page 0x83 of the device.
3286 * Returns the identifier or error on failure.
3288 int scsi_vpd_tpg_id(struct scsi_device *sdev, int *rel_id)
3290 const unsigned char *d;
3291 const struct scsi_vpd *vpd_pg83;
3292 int group_id = -EAGAIN, rel_port = -1;
3295 vpd_pg83 = rcu_dereference(sdev->vpd_pg83);
3301 d = vpd_pg83->data + 4;
3302 while (d < vpd_pg83->data + vpd_pg83->len) {
3303 switch (d[1] & 0xf) {
3305 /* Relative target port */
3306 rel_port = get_unaligned_be16(&d[6]);
3309 /* Target port group */
3310 group_id = get_unaligned_be16(&d[6]);
3319 if (group_id >= 0 && rel_id && rel_port != -1)
3324 EXPORT_SYMBOL(scsi_vpd_tpg_id);
3327 * scsi_build_sense - build sense data for a command
3328 * @scmd: scsi command for which the sense should be formatted
3329 * @desc: Sense format (non-zero == descriptor format,
3330 * 0 == fixed format)
3332 * @asc: Additional sense code
3333 * @ascq: Additional sense code qualifier
3336 void scsi_build_sense(struct scsi_cmnd *scmd, int desc, u8 key, u8 asc, u8 ascq)
3338 scsi_build_sense_buffer(desc, scmd->sense_buffer, key, asc, ascq);
3339 scmd->result = SAM_STAT_CHECK_CONDITION;
3341 EXPORT_SYMBOL_GPL(scsi_build_sense);