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/ratelimit.h>
25 #include <asm/unaligned.h>
27 #include <scsi/scsi.h>
28 #include <scsi/scsi_cmnd.h>
29 #include <scsi/scsi_dbg.h>
30 #include <scsi/scsi_device.h>
31 #include <scsi/scsi_driver.h>
32 #include <scsi/scsi_eh.h>
33 #include <scsi/scsi_host.h>
34 #include <scsi/scsi_transport.h> /* __scsi_init_queue() */
35 #include <scsi/scsi_dh.h>
37 #include <trace/events/scsi.h>
39 #include "scsi_debugfs.h"
40 #include "scsi_priv.h"
41 #include "scsi_logging.h"
44 * Size of integrity metadata is usually small, 1 inline sg should
47 #ifdef CONFIG_ARCH_NO_SG_CHAIN
48 #define SCSI_INLINE_PROT_SG_CNT 0
49 #define SCSI_INLINE_SG_CNT 0
51 #define SCSI_INLINE_PROT_SG_CNT 1
52 #define SCSI_INLINE_SG_CNT 2
55 static struct kmem_cache
*scsi_sense_cache
;
56 static struct kmem_cache
*scsi_sense_isadma_cache
;
57 static DEFINE_MUTEX(scsi_sense_cache_mutex
);
59 static void scsi_mq_uninit_cmd(struct scsi_cmnd
*cmd
);
61 static inline struct kmem_cache
*
62 scsi_select_sense_cache(bool unchecked_isa_dma
)
64 return unchecked_isa_dma
? scsi_sense_isadma_cache
: scsi_sense_cache
;
67 static void scsi_free_sense_buffer(bool unchecked_isa_dma
,
68 unsigned char *sense_buffer
)
70 kmem_cache_free(scsi_select_sense_cache(unchecked_isa_dma
),
74 static unsigned char *scsi_alloc_sense_buffer(bool unchecked_isa_dma
,
75 gfp_t gfp_mask
, int numa_node
)
77 return kmem_cache_alloc_node(scsi_select_sense_cache(unchecked_isa_dma
),
81 int scsi_init_sense_cache(struct Scsi_Host
*shost
)
83 struct kmem_cache
*cache
;
86 mutex_lock(&scsi_sense_cache_mutex
);
87 cache
= scsi_select_sense_cache(shost
->unchecked_isa_dma
);
91 if (shost
->unchecked_isa_dma
) {
92 scsi_sense_isadma_cache
=
93 kmem_cache_create("scsi_sense_cache(DMA)",
94 SCSI_SENSE_BUFFERSIZE
, 0,
95 SLAB_HWCACHE_ALIGN
| SLAB_CACHE_DMA
, NULL
);
96 if (!scsi_sense_isadma_cache
)
100 kmem_cache_create_usercopy("scsi_sense_cache",
101 SCSI_SENSE_BUFFERSIZE
, 0, SLAB_HWCACHE_ALIGN
,
102 0, SCSI_SENSE_BUFFERSIZE
, NULL
);
103 if (!scsi_sense_cache
)
107 mutex_unlock(&scsi_sense_cache_mutex
);
112 * When to reinvoke queueing after a resource shortage. It's 3 msecs to
113 * not change behaviour from the previous unplug mechanism, experimentation
114 * may prove this needs changing.
116 #define SCSI_QUEUE_DELAY 3
119 scsi_set_blocked(struct scsi_cmnd
*cmd
, int reason
)
121 struct Scsi_Host
*host
= cmd
->device
->host
;
122 struct scsi_device
*device
= cmd
->device
;
123 struct scsi_target
*starget
= scsi_target(device
);
126 * Set the appropriate busy bit for the device/host.
128 * If the host/device isn't busy, assume that something actually
129 * completed, and that we should be able to queue a command now.
131 * Note that the prior mid-layer assumption that any host could
132 * always queue at least one command is now broken. The mid-layer
133 * will implement a user specifiable stall (see
134 * scsi_host.max_host_blocked and scsi_device.max_device_blocked)
135 * if a command is requeued with no other commands outstanding
136 * either for the device or for the host.
139 case SCSI_MLQUEUE_HOST_BUSY
:
140 atomic_set(&host
->host_blocked
, host
->max_host_blocked
);
142 case SCSI_MLQUEUE_DEVICE_BUSY
:
143 case SCSI_MLQUEUE_EH_RETRY
:
144 atomic_set(&device
->device_blocked
,
145 device
->max_device_blocked
);
147 case SCSI_MLQUEUE_TARGET_BUSY
:
148 atomic_set(&starget
->target_blocked
,
149 starget
->max_target_blocked
);
154 static void scsi_mq_requeue_cmd(struct scsi_cmnd
*cmd
)
156 if (cmd
->request
->rq_flags
& RQF_DONTPREP
) {
157 cmd
->request
->rq_flags
&= ~RQF_DONTPREP
;
158 scsi_mq_uninit_cmd(cmd
);
162 blk_mq_requeue_request(cmd
->request
, true);
166 * __scsi_queue_insert - private queue insertion
167 * @cmd: The SCSI command being requeued
168 * @reason: The reason for the requeue
169 * @unbusy: Whether the queue should be unbusied
171 * This is a private queue insertion. The public interface
172 * scsi_queue_insert() always assumes the queue should be unbusied
173 * because it's always called before the completion. This function is
174 * for a requeue after completion, which should only occur in this
177 static void __scsi_queue_insert(struct scsi_cmnd
*cmd
, int reason
, bool unbusy
)
179 struct scsi_device
*device
= cmd
->device
;
181 SCSI_LOG_MLQUEUE(1, scmd_printk(KERN_INFO
, cmd
,
182 "Inserting command %p into mlqueue\n", cmd
));
184 scsi_set_blocked(cmd
, reason
);
187 * Decrement the counters, since these commands are no longer
188 * active on the host/device.
191 scsi_device_unbusy(device
, cmd
);
194 * Requeue this command. It will go before all other commands
195 * that are already in the queue. Schedule requeue work under
196 * lock such that the kblockd_schedule_work() call happens
197 * before blk_cleanup_queue() finishes.
201 blk_mq_requeue_request(cmd
->request
, true);
205 * scsi_queue_insert - Reinsert a command in the queue.
206 * @cmd: command that we are adding to queue.
207 * @reason: why we are inserting command to queue.
209 * We do this for one of two cases. Either the host is busy and it cannot accept
210 * any more commands for the time being, or the device returned QUEUE_FULL and
211 * can accept no more commands.
213 * Context: This could be called either from an interrupt context or a normal
216 void scsi_queue_insert(struct scsi_cmnd
*cmd
, int reason
)
218 __scsi_queue_insert(cmd
, reason
, true);
223 * __scsi_execute - insert request and wait for the result
226 * @data_direction: data direction
227 * @buffer: data buffer
228 * @bufflen: len of buffer
229 * @sense: optional sense buffer
230 * @sshdr: optional decoded sense header
231 * @timeout: request timeout in seconds
232 * @retries: number of times to retry request
233 * @flags: flags for ->cmd_flags
234 * @rq_flags: flags for ->rq_flags
235 * @resid: optional residual length
237 * Returns the scsi_cmnd result field if a command was executed, or a negative
238 * Linux error code if we didn't get that far.
240 int __scsi_execute(struct scsi_device
*sdev
, const unsigned char *cmd
,
241 int data_direction
, void *buffer
, unsigned bufflen
,
242 unsigned char *sense
, struct scsi_sense_hdr
*sshdr
,
243 int timeout
, int retries
, u64 flags
, req_flags_t rq_flags
,
247 struct scsi_request
*rq
;
248 int ret
= DRIVER_ERROR
<< 24;
250 req
= blk_get_request(sdev
->request_queue
,
251 data_direction
== DMA_TO_DEVICE
?
252 REQ_OP_SCSI_OUT
: REQ_OP_SCSI_IN
, BLK_MQ_REQ_PREEMPT
);
257 if (bufflen
&& blk_rq_map_kern(sdev
->request_queue
, req
,
258 buffer
, bufflen
, GFP_NOIO
))
261 rq
->cmd_len
= COMMAND_SIZE(cmd
[0]);
262 memcpy(rq
->cmd
, cmd
, rq
->cmd_len
);
263 rq
->retries
= retries
;
264 req
->timeout
= timeout
;
265 req
->cmd_flags
|= flags
;
266 req
->rq_flags
|= rq_flags
| RQF_QUIET
;
269 * head injection *required* here otherwise quiesce won't work
271 blk_execute_rq(req
->q
, NULL
, req
, 1);
274 * Some devices (USB mass-storage in particular) may transfer
275 * garbage data together with a residue indicating that the data
276 * is invalid. Prevent the garbage from being misinterpreted
277 * and prevent security leaks by zeroing out the excess data.
279 if (unlikely(rq
->resid_len
> 0 && rq
->resid_len
<= bufflen
))
280 memset(buffer
+ (bufflen
- rq
->resid_len
), 0, rq
->resid_len
);
283 *resid
= rq
->resid_len
;
284 if (sense
&& rq
->sense_len
)
285 memcpy(sense
, rq
->sense
, SCSI_SENSE_BUFFERSIZE
);
287 scsi_normalize_sense(rq
->sense
, rq
->sense_len
, sshdr
);
290 blk_put_request(req
);
294 EXPORT_SYMBOL(__scsi_execute
);
297 * Wake up the error handler if necessary. Avoid as follows that the error
298 * handler is not woken up if host in-flight requests number ==
299 * shost->host_failed: use call_rcu() in scsi_eh_scmd_add() in combination
300 * with an RCU read lock in this function to ensure that this function in
301 * its entirety either finishes before scsi_eh_scmd_add() increases the
302 * host_failed counter or that it notices the shost state change made by
303 * scsi_eh_scmd_add().
305 static void scsi_dec_host_busy(struct Scsi_Host
*shost
, struct scsi_cmnd
*cmd
)
310 __clear_bit(SCMD_STATE_INFLIGHT
, &cmd
->state
);
311 if (unlikely(scsi_host_in_recovery(shost
))) {
312 spin_lock_irqsave(shost
->host_lock
, flags
);
313 if (shost
->host_failed
|| shost
->host_eh_scheduled
)
314 scsi_eh_wakeup(shost
);
315 spin_unlock_irqrestore(shost
->host_lock
, flags
);
320 void scsi_device_unbusy(struct scsi_device
*sdev
, struct scsi_cmnd
*cmd
)
322 struct Scsi_Host
*shost
= sdev
->host
;
323 struct scsi_target
*starget
= scsi_target(sdev
);
325 scsi_dec_host_busy(shost
, cmd
);
327 if (starget
->can_queue
> 0)
328 atomic_dec(&starget
->target_busy
);
330 atomic_dec(&sdev
->device_busy
);
333 static void scsi_kick_queue(struct request_queue
*q
)
335 blk_mq_run_hw_queues(q
, false);
339 * Called for single_lun devices on IO completion. Clear starget_sdev_user,
340 * and call blk_run_queue for all the scsi_devices on the target -
341 * including current_sdev first.
343 * Called with *no* scsi locks held.
345 static void scsi_single_lun_run(struct scsi_device
*current_sdev
)
347 struct Scsi_Host
*shost
= current_sdev
->host
;
348 struct scsi_device
*sdev
, *tmp
;
349 struct scsi_target
*starget
= scsi_target(current_sdev
);
352 spin_lock_irqsave(shost
->host_lock
, flags
);
353 starget
->starget_sdev_user
= NULL
;
354 spin_unlock_irqrestore(shost
->host_lock
, flags
);
357 * Call blk_run_queue for all LUNs on the target, starting with
358 * current_sdev. We race with others (to set starget_sdev_user),
359 * but in most cases, we will be first. Ideally, each LU on the
360 * target would get some limited time or requests on the target.
362 scsi_kick_queue(current_sdev
->request_queue
);
364 spin_lock_irqsave(shost
->host_lock
, flags
);
365 if (starget
->starget_sdev_user
)
367 list_for_each_entry_safe(sdev
, tmp
, &starget
->devices
,
368 same_target_siblings
) {
369 if (sdev
== current_sdev
)
371 if (scsi_device_get(sdev
))
374 spin_unlock_irqrestore(shost
->host_lock
, flags
);
375 scsi_kick_queue(sdev
->request_queue
);
376 spin_lock_irqsave(shost
->host_lock
, flags
);
378 scsi_device_put(sdev
);
381 spin_unlock_irqrestore(shost
->host_lock
, flags
);
384 static inline bool scsi_device_is_busy(struct scsi_device
*sdev
)
386 if (atomic_read(&sdev
->device_busy
) >= sdev
->queue_depth
)
388 if (atomic_read(&sdev
->device_blocked
) > 0)
393 static inline bool scsi_target_is_busy(struct scsi_target
*starget
)
395 if (starget
->can_queue
> 0) {
396 if (atomic_read(&starget
->target_busy
) >= starget
->can_queue
)
398 if (atomic_read(&starget
->target_blocked
) > 0)
404 static inline bool scsi_host_is_busy(struct Scsi_Host
*shost
)
406 if (atomic_read(&shost
->host_blocked
) > 0)
408 if (shost
->host_self_blocked
)
413 static void scsi_starved_list_run(struct Scsi_Host
*shost
)
415 LIST_HEAD(starved_list
);
416 struct scsi_device
*sdev
;
419 spin_lock_irqsave(shost
->host_lock
, flags
);
420 list_splice_init(&shost
->starved_list
, &starved_list
);
422 while (!list_empty(&starved_list
)) {
423 struct request_queue
*slq
;
426 * As long as shost is accepting commands and we have
427 * starved queues, call blk_run_queue. scsi_request_fn
428 * drops the queue_lock and can add us back to the
431 * host_lock protects the starved_list and starved_entry.
432 * scsi_request_fn must get the host_lock before checking
433 * or modifying starved_list or starved_entry.
435 if (scsi_host_is_busy(shost
))
438 sdev
= list_entry(starved_list
.next
,
439 struct scsi_device
, starved_entry
);
440 list_del_init(&sdev
->starved_entry
);
441 if (scsi_target_is_busy(scsi_target(sdev
))) {
442 list_move_tail(&sdev
->starved_entry
,
443 &shost
->starved_list
);
448 * Once we drop the host lock, a racing scsi_remove_device()
449 * call may remove the sdev from the starved list and destroy
450 * it and the queue. Mitigate by taking a reference to the
451 * queue and never touching the sdev again after we drop the
452 * host lock. Note: if __scsi_remove_device() invokes
453 * blk_cleanup_queue() before the queue is run from this
454 * function then blk_run_queue() will return immediately since
455 * blk_cleanup_queue() marks the queue with QUEUE_FLAG_DYING.
457 slq
= sdev
->request_queue
;
458 if (!blk_get_queue(slq
))
460 spin_unlock_irqrestore(shost
->host_lock
, flags
);
462 scsi_kick_queue(slq
);
465 spin_lock_irqsave(shost
->host_lock
, flags
);
467 /* put any unprocessed entries back */
468 list_splice(&starved_list
, &shost
->starved_list
);
469 spin_unlock_irqrestore(shost
->host_lock
, flags
);
473 * scsi_run_queue - Select a proper request queue to serve next.
474 * @q: last request's queue
476 * The previous command was completely finished, start a new one if possible.
478 static void scsi_run_queue(struct request_queue
*q
)
480 struct scsi_device
*sdev
= q
->queuedata
;
482 if (scsi_target(sdev
)->single_lun
)
483 scsi_single_lun_run(sdev
);
484 if (!list_empty(&sdev
->host
->starved_list
))
485 scsi_starved_list_run(sdev
->host
);
487 blk_mq_run_hw_queues(q
, false);
490 void scsi_requeue_run_queue(struct work_struct
*work
)
492 struct scsi_device
*sdev
;
493 struct request_queue
*q
;
495 sdev
= container_of(work
, struct scsi_device
, requeue_work
);
496 q
= sdev
->request_queue
;
500 void scsi_run_host_queues(struct Scsi_Host
*shost
)
502 struct scsi_device
*sdev
;
504 shost_for_each_device(sdev
, shost
)
505 scsi_run_queue(sdev
->request_queue
);
508 static void scsi_uninit_cmd(struct scsi_cmnd
*cmd
)
510 if (!blk_rq_is_passthrough(cmd
->request
)) {
511 struct scsi_driver
*drv
= scsi_cmd_to_driver(cmd
);
513 if (drv
->uninit_command
)
514 drv
->uninit_command(cmd
);
518 void scsi_free_sgtables(struct scsi_cmnd
*cmd
)
520 if (cmd
->sdb
.table
.nents
)
521 sg_free_table_chained(&cmd
->sdb
.table
,
523 if (scsi_prot_sg_count(cmd
))
524 sg_free_table_chained(&cmd
->prot_sdb
->table
,
525 SCSI_INLINE_PROT_SG_CNT
);
527 EXPORT_SYMBOL_GPL(scsi_free_sgtables
);
529 static void scsi_mq_uninit_cmd(struct scsi_cmnd
*cmd
)
531 scsi_free_sgtables(cmd
);
532 scsi_uninit_cmd(cmd
);
535 static void scsi_run_queue_async(struct scsi_device
*sdev
)
537 if (scsi_target(sdev
)->single_lun
||
538 !list_empty(&sdev
->host
->starved_list
)) {
539 kblockd_schedule_work(&sdev
->requeue_work
);
542 * smp_mb() present in sbitmap_queue_clear() or implied in
543 * .end_io is for ordering writing .device_busy in
544 * scsi_device_unbusy() and reading sdev->restarts.
546 int old
= atomic_read(&sdev
->restarts
);
549 * ->restarts has to be kept as non-zero if new budget
552 * No need to run queue when either another re-run
553 * queue wins in updating ->restarts or a new budget
556 if (old
&& atomic_cmpxchg(&sdev
->restarts
, old
, 0) == old
)
557 blk_mq_run_hw_queues(sdev
->request_queue
, true);
561 /* Returns false when no more bytes to process, true if there are more */
562 static bool scsi_end_request(struct request
*req
, blk_status_t error
,
565 struct scsi_cmnd
*cmd
= blk_mq_rq_to_pdu(req
);
566 struct scsi_device
*sdev
= cmd
->device
;
567 struct request_queue
*q
= sdev
->request_queue
;
569 if (blk_update_request(req
, error
, bytes
))
572 if (blk_queue_add_random(q
))
573 add_disk_randomness(req
->rq_disk
);
575 if (!blk_rq_is_scsi(req
)) {
576 WARN_ON_ONCE(!(cmd
->flags
& SCMD_INITIALIZED
));
577 cmd
->flags
&= ~SCMD_INITIALIZED
;
581 * Calling rcu_barrier() is not necessary here because the
582 * SCSI error handler guarantees that the function called by
583 * call_rcu() has been called before scsi_end_request() is
586 destroy_rcu_head(&cmd
->rcu
);
589 * In the MQ case the command gets freed by __blk_mq_end_request,
590 * so we have to do all cleanup that depends on it earlier.
592 * We also can't kick the queues from irq context, so we
593 * will have to defer it to a workqueue.
595 scsi_mq_uninit_cmd(cmd
);
598 * queue is still alive, so grab the ref for preventing it
599 * from being cleaned up during running queue.
601 percpu_ref_get(&q
->q_usage_counter
);
603 __blk_mq_end_request(req
, error
);
605 scsi_run_queue_async(sdev
);
607 percpu_ref_put(&q
->q_usage_counter
);
612 * scsi_result_to_blk_status - translate a SCSI result code into blk_status_t
614 * @result: scsi error code
616 * Translate a SCSI result code into a blk_status_t value. May reset the host
617 * byte of @cmd->result.
619 static blk_status_t
scsi_result_to_blk_status(struct scsi_cmnd
*cmd
, int result
)
621 switch (host_byte(result
)) {
624 * Also check the other bytes than the status byte in result
625 * to handle the case when a SCSI LLD sets result to
626 * DRIVER_SENSE << 24 without setting SAM_STAT_CHECK_CONDITION.
628 if (scsi_status_is_good(result
) && (result
& ~0xff) == 0)
630 return BLK_STS_IOERR
;
631 case DID_TRANSPORT_FAILFAST
:
632 return BLK_STS_TRANSPORT
;
633 case DID_TARGET_FAILURE
:
634 set_host_byte(cmd
, DID_OK
);
635 return BLK_STS_TARGET
;
636 case DID_NEXUS_FAILURE
:
637 set_host_byte(cmd
, DID_OK
);
638 return BLK_STS_NEXUS
;
639 case DID_ALLOC_FAILURE
:
640 set_host_byte(cmd
, DID_OK
);
641 return BLK_STS_NOSPC
;
642 case DID_MEDIUM_ERROR
:
643 set_host_byte(cmd
, DID_OK
);
644 return BLK_STS_MEDIUM
;
646 return BLK_STS_IOERR
;
650 /* Helper for scsi_io_completion() when "reprep" action required. */
651 static void scsi_io_completion_reprep(struct scsi_cmnd
*cmd
,
652 struct request_queue
*q
)
654 /* A new command will be prepared and issued. */
655 scsi_mq_requeue_cmd(cmd
);
658 static bool scsi_cmd_runtime_exceeced(struct scsi_cmnd
*cmd
)
660 struct request
*req
= cmd
->request
;
661 unsigned long wait_for
;
663 if (cmd
->allowed
== SCSI_CMD_RETRIES_NO_LIMIT
)
666 wait_for
= (cmd
->allowed
+ 1) * req
->timeout
;
667 if (time_before(cmd
->jiffies_at_alloc
+ wait_for
, jiffies
)) {
668 scmd_printk(KERN_ERR
, cmd
, "timing out command, waited %lus\n",
675 /* Helper for scsi_io_completion() when special action required. */
676 static void scsi_io_completion_action(struct scsi_cmnd
*cmd
, int result
)
678 struct request_queue
*q
= cmd
->device
->request_queue
;
679 struct request
*req
= cmd
->request
;
681 enum {ACTION_FAIL
, ACTION_REPREP
, ACTION_RETRY
,
682 ACTION_DELAYED_RETRY
} action
;
683 struct scsi_sense_hdr sshdr
;
685 bool sense_current
= true; /* false implies "deferred sense" */
686 blk_status_t blk_stat
;
688 sense_valid
= scsi_command_normalize_sense(cmd
, &sshdr
);
690 sense_current
= !scsi_sense_is_deferred(&sshdr
);
692 blk_stat
= scsi_result_to_blk_status(cmd
, result
);
694 if (host_byte(result
) == DID_RESET
) {
695 /* Third party bus reset or reset for error recovery
696 * reasons. Just retry the command and see what
699 action
= ACTION_RETRY
;
700 } else if (sense_valid
&& sense_current
) {
701 switch (sshdr
.sense_key
) {
703 if (cmd
->device
->removable
) {
704 /* Detected disc change. Set a bit
705 * and quietly refuse further access.
707 cmd
->device
->changed
= 1;
708 action
= ACTION_FAIL
;
710 /* Must have been a power glitch, or a
711 * bus reset. Could not have been a
712 * media change, so we just retry the
713 * command and see what happens.
715 action
= ACTION_RETRY
;
718 case ILLEGAL_REQUEST
:
719 /* If we had an ILLEGAL REQUEST returned, then
720 * we may have performed an unsupported
721 * command. The only thing this should be
722 * would be a ten byte read where only a six
723 * byte read was supported. Also, on a system
724 * where READ CAPACITY failed, we may have
725 * read past the end of the disk.
727 if ((cmd
->device
->use_10_for_rw
&&
728 sshdr
.asc
== 0x20 && sshdr
.ascq
== 0x00) &&
729 (cmd
->cmnd
[0] == READ_10
||
730 cmd
->cmnd
[0] == WRITE_10
)) {
731 /* This will issue a new 6-byte command. */
732 cmd
->device
->use_10_for_rw
= 0;
733 action
= ACTION_REPREP
;
734 } else if (sshdr
.asc
== 0x10) /* DIX */ {
735 action
= ACTION_FAIL
;
736 blk_stat
= BLK_STS_PROTECTION
;
737 /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
738 } else if (sshdr
.asc
== 0x20 || sshdr
.asc
== 0x24) {
739 action
= ACTION_FAIL
;
740 blk_stat
= BLK_STS_TARGET
;
742 action
= ACTION_FAIL
;
744 case ABORTED_COMMAND
:
745 action
= ACTION_FAIL
;
746 if (sshdr
.asc
== 0x10) /* DIF */
747 blk_stat
= BLK_STS_PROTECTION
;
750 /* If the device is in the process of becoming
751 * ready, or has a temporary blockage, retry.
753 if (sshdr
.asc
== 0x04) {
754 switch (sshdr
.ascq
) {
755 case 0x01: /* becoming ready */
756 case 0x04: /* format in progress */
757 case 0x05: /* rebuild in progress */
758 case 0x06: /* recalculation in progress */
759 case 0x07: /* operation in progress */
760 case 0x08: /* Long write in progress */
761 case 0x09: /* self test in progress */
762 case 0x14: /* space allocation in progress */
763 case 0x1a: /* start stop unit in progress */
764 case 0x1b: /* sanitize in progress */
765 case 0x1d: /* configuration in progress */
766 case 0x24: /* depopulation in progress */
767 action
= ACTION_DELAYED_RETRY
;
769 case 0x0a: /* ALUA state transition */
770 blk_stat
= BLK_STS_AGAIN
;
773 action
= ACTION_FAIL
;
777 action
= ACTION_FAIL
;
779 case VOLUME_OVERFLOW
:
780 /* See SSC3rXX or current. */
781 action
= ACTION_FAIL
;
784 action
= ACTION_FAIL
;
785 if ((sshdr
.asc
== 0x0C && sshdr
.ascq
== 0x12) ||
786 (sshdr
.asc
== 0x55 &&
787 (sshdr
.ascq
== 0x0E || sshdr
.ascq
== 0x0F))) {
788 /* Insufficient zone resources */
789 blk_stat
= BLK_STS_ZONE_OPEN_RESOURCE
;
793 action
= ACTION_FAIL
;
797 action
= ACTION_FAIL
;
799 if (action
!= ACTION_FAIL
&& scsi_cmd_runtime_exceeced(cmd
))
800 action
= ACTION_FAIL
;
804 /* Give up and fail the remainder of the request */
805 if (!(req
->rq_flags
& RQF_QUIET
)) {
806 static DEFINE_RATELIMIT_STATE(_rs
,
807 DEFAULT_RATELIMIT_INTERVAL
,
808 DEFAULT_RATELIMIT_BURST
);
810 if (unlikely(scsi_logging_level
))
812 SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT
,
813 SCSI_LOG_MLCOMPLETE_BITS
);
816 * if logging is enabled the failure will be printed
817 * in scsi_log_completion(), so avoid duplicate messages
819 if (!level
&& __ratelimit(&_rs
)) {
820 scsi_print_result(cmd
, NULL
, FAILED
);
821 if (driver_byte(result
) == DRIVER_SENSE
)
822 scsi_print_sense(cmd
);
823 scsi_print_command(cmd
);
826 if (!scsi_end_request(req
, blk_stat
, blk_rq_err_bytes(req
)))
830 scsi_io_completion_reprep(cmd
, q
);
833 /* Retry the same command immediately */
834 __scsi_queue_insert(cmd
, SCSI_MLQUEUE_EH_RETRY
, false);
836 case ACTION_DELAYED_RETRY
:
837 /* Retry the same command after a delay */
838 __scsi_queue_insert(cmd
, SCSI_MLQUEUE_DEVICE_BUSY
, false);
844 * Helper for scsi_io_completion() when cmd->result is non-zero. Returns a
845 * new result that may suppress further error checking. Also modifies
846 * *blk_statp in some cases.
848 static int scsi_io_completion_nz_result(struct scsi_cmnd
*cmd
, int result
,
849 blk_status_t
*blk_statp
)
852 bool sense_current
= true; /* false implies "deferred sense" */
853 struct request
*req
= cmd
->request
;
854 struct scsi_sense_hdr sshdr
;
856 sense_valid
= scsi_command_normalize_sense(cmd
, &sshdr
);
858 sense_current
= !scsi_sense_is_deferred(&sshdr
);
860 if (blk_rq_is_passthrough(req
)) {
863 * SG_IO wants current and deferred errors
865 scsi_req(req
)->sense_len
=
866 min(8 + cmd
->sense_buffer
[7],
867 SCSI_SENSE_BUFFERSIZE
);
870 *blk_statp
= scsi_result_to_blk_status(cmd
, result
);
871 } else if (blk_rq_bytes(req
) == 0 && sense_current
) {
873 * Flush commands do not transfers any data, and thus cannot use
874 * good_bytes != blk_rq_bytes(req) as the signal for an error.
875 * This sets *blk_statp explicitly for the problem case.
877 *blk_statp
= scsi_result_to_blk_status(cmd
, result
);
880 * Recovered errors need reporting, but they're always treated as
881 * success, so fiddle the result code here. For passthrough requests
882 * we already took a copy of the original into sreq->result which
883 * is what gets returned to the user
885 if (sense_valid
&& (sshdr
.sense_key
== RECOVERED_ERROR
)) {
886 bool do_print
= true;
888 * if ATA PASS-THROUGH INFORMATION AVAILABLE [0x0, 0x1d]
889 * skip print since caller wants ATA registers. Only occurs
890 * on SCSI ATA PASS_THROUGH commands when CK_COND=1
892 if ((sshdr
.asc
== 0x0) && (sshdr
.ascq
== 0x1d))
894 else if (req
->rq_flags
& RQF_QUIET
)
897 scsi_print_sense(cmd
);
899 /* for passthrough, *blk_statp may be set */
900 *blk_statp
= BLK_STS_OK
;
903 * Another corner case: the SCSI status byte is non-zero but 'good'.
904 * Example: PRE-FETCH command returns SAM_STAT_CONDITION_MET when
905 * it is able to fit nominated LBs in its cache (and SAM_STAT_GOOD
906 * if it can't fit). Treat SAM_STAT_CONDITION_MET and the related
907 * intermediate statuses (both obsolete in SAM-4) as good.
909 if (status_byte(result
) && scsi_status_is_good(result
)) {
911 *blk_statp
= BLK_STS_OK
;
917 * scsi_io_completion - Completion processing for SCSI commands.
918 * @cmd: command that is finished.
919 * @good_bytes: number of processed bytes.
921 * We will finish off the specified number of sectors. If we are done, the
922 * command block will be released and the queue function will be goosed. If we
923 * are not done then we have to figure out what to do next:
925 * a) We can call scsi_io_completion_reprep(). The request will be
926 * unprepared and put back on the queue. Then a new command will
927 * be created for it. This should be used if we made forward
928 * progress, or if we want to switch from READ(10) to READ(6) for
931 * b) We can call scsi_io_completion_action(). The request will be
932 * put back on the queue and retried using the same command as
933 * before, possibly after a delay.
935 * c) We can call scsi_end_request() with blk_stat other than
936 * BLK_STS_OK, to fail the remainder of the request.
938 void scsi_io_completion(struct scsi_cmnd
*cmd
, unsigned int good_bytes
)
940 int result
= cmd
->result
;
941 struct request_queue
*q
= cmd
->device
->request_queue
;
942 struct request
*req
= cmd
->request
;
943 blk_status_t blk_stat
= BLK_STS_OK
;
945 if (unlikely(result
)) /* a nz result may or may not be an error */
946 result
= scsi_io_completion_nz_result(cmd
, result
, &blk_stat
);
948 if (unlikely(blk_rq_is_passthrough(req
))) {
950 * scsi_result_to_blk_status may have reset the host_byte
952 scsi_req(req
)->result
= cmd
->result
;
956 * Next deal with any sectors which we were able to correctly
959 SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO
, cmd
,
960 "%u sectors total, %d bytes done.\n",
961 blk_rq_sectors(req
), good_bytes
));
964 * Failed, zero length commands always need to drop down
965 * to retry code. Fast path should return in this block.
967 if (likely(blk_rq_bytes(req
) > 0 || blk_stat
== BLK_STS_OK
)) {
968 if (likely(!scsi_end_request(req
, blk_stat
, good_bytes
)))
969 return; /* no bytes remaining */
972 /* Kill remainder if no retries. */
973 if (unlikely(blk_stat
&& scsi_noretry_cmd(cmd
))) {
974 if (scsi_end_request(req
, blk_stat
, blk_rq_bytes(req
)))
976 "Bytes remaining after failed, no-retry command");
981 * If there had been no error, but we have leftover bytes in the
982 * requeues just queue the command up again.
984 if (likely(result
== 0))
985 scsi_io_completion_reprep(cmd
, q
);
987 scsi_io_completion_action(cmd
, result
);
990 static inline bool scsi_cmd_needs_dma_drain(struct scsi_device
*sdev
,
993 return sdev
->dma_drain_len
&& blk_rq_is_passthrough(rq
) &&
994 !op_is_write(req_op(rq
)) &&
995 sdev
->host
->hostt
->dma_need_drain(rq
);
999 * scsi_alloc_sgtables - allocate S/G tables for a command
1000 * @cmd: command descriptor we wish to initialize
1003 * * BLK_STS_OK - on success
1004 * * BLK_STS_RESOURCE - if the failure is retryable
1005 * * BLK_STS_IOERR - if the failure is fatal
1007 blk_status_t
scsi_alloc_sgtables(struct scsi_cmnd
*cmd
)
1009 struct scsi_device
*sdev
= cmd
->device
;
1010 struct request
*rq
= cmd
->request
;
1011 unsigned short nr_segs
= blk_rq_nr_phys_segments(rq
);
1012 struct scatterlist
*last_sg
= NULL
;
1014 bool need_drain
= scsi_cmd_needs_dma_drain(sdev
, rq
);
1017 if (WARN_ON_ONCE(!nr_segs
))
1018 return BLK_STS_IOERR
;
1021 * Make sure there is space for the drain. The driver must adjust
1022 * max_hw_segments to be prepared for this.
1028 * If sg table allocation fails, requeue request later.
1030 if (unlikely(sg_alloc_table_chained(&cmd
->sdb
.table
, nr_segs
,
1031 cmd
->sdb
.table
.sgl
, SCSI_INLINE_SG_CNT
)))
1032 return BLK_STS_RESOURCE
;
1035 * Next, walk the list, and fill in the addresses and sizes of
1038 count
= __blk_rq_map_sg(rq
->q
, rq
, cmd
->sdb
.table
.sgl
, &last_sg
);
1040 if (blk_rq_bytes(rq
) & rq
->q
->dma_pad_mask
) {
1041 unsigned int pad_len
=
1042 (rq
->q
->dma_pad_mask
& ~blk_rq_bytes(rq
)) + 1;
1044 last_sg
->length
+= pad_len
;
1045 cmd
->extra_len
+= pad_len
;
1049 sg_unmark_end(last_sg
);
1050 last_sg
= sg_next(last_sg
);
1051 sg_set_buf(last_sg
, sdev
->dma_drain_buf
, sdev
->dma_drain_len
);
1052 sg_mark_end(last_sg
);
1054 cmd
->extra_len
+= sdev
->dma_drain_len
;
1058 BUG_ON(count
> cmd
->sdb
.table
.nents
);
1059 cmd
->sdb
.table
.nents
= count
;
1060 cmd
->sdb
.length
= blk_rq_payload_bytes(rq
);
1062 if (blk_integrity_rq(rq
)) {
1063 struct scsi_data_buffer
*prot_sdb
= cmd
->prot_sdb
;
1066 if (WARN_ON_ONCE(!prot_sdb
)) {
1068 * This can happen if someone (e.g. multipath)
1069 * queues a command to a device on an adapter
1070 * that does not support DIX.
1072 ret
= BLK_STS_IOERR
;
1073 goto out_free_sgtables
;
1076 ivecs
= blk_rq_count_integrity_sg(rq
->q
, rq
->bio
);
1078 if (sg_alloc_table_chained(&prot_sdb
->table
, ivecs
,
1079 prot_sdb
->table
.sgl
,
1080 SCSI_INLINE_PROT_SG_CNT
)) {
1081 ret
= BLK_STS_RESOURCE
;
1082 goto out_free_sgtables
;
1085 count
= blk_rq_map_integrity_sg(rq
->q
, rq
->bio
,
1086 prot_sdb
->table
.sgl
);
1087 BUG_ON(count
> ivecs
);
1088 BUG_ON(count
> queue_max_integrity_segments(rq
->q
));
1090 cmd
->prot_sdb
= prot_sdb
;
1091 cmd
->prot_sdb
->table
.nents
= count
;
1096 scsi_free_sgtables(cmd
);
1099 EXPORT_SYMBOL(scsi_alloc_sgtables
);
1102 * scsi_initialize_rq - initialize struct scsi_cmnd partially
1103 * @rq: Request associated with the SCSI command to be initialized.
1105 * This function initializes the members of struct scsi_cmnd that must be
1106 * initialized before request processing starts and that won't be
1107 * reinitialized if a SCSI command is requeued.
1109 * Called from inside blk_get_request() for pass-through requests and from
1110 * inside scsi_init_command() for filesystem requests.
1112 static void scsi_initialize_rq(struct request
*rq
)
1114 struct scsi_cmnd
*cmd
= blk_mq_rq_to_pdu(rq
);
1116 scsi_req_init(&cmd
->req
);
1117 init_rcu_head(&cmd
->rcu
);
1118 cmd
->jiffies_at_alloc
= jiffies
;
1123 * Only called when the request isn't completed by SCSI, and not freed by
1126 static void scsi_cleanup_rq(struct request
*rq
)
1128 if (rq
->rq_flags
& RQF_DONTPREP
) {
1129 scsi_mq_uninit_cmd(blk_mq_rq_to_pdu(rq
));
1130 rq
->rq_flags
&= ~RQF_DONTPREP
;
1134 /* Called before a request is prepared. See also scsi_mq_prep_fn(). */
1135 void scsi_init_command(struct scsi_device
*dev
, struct scsi_cmnd
*cmd
)
1137 void *buf
= cmd
->sense_buffer
;
1138 void *prot
= cmd
->prot_sdb
;
1139 struct request
*rq
= blk_mq_rq_from_pdu(cmd
);
1140 unsigned int flags
= cmd
->flags
& SCMD_PRESERVED_FLAGS
;
1141 unsigned long jiffies_at_alloc
;
1142 int retries
, to_clear
;
1145 if (!blk_rq_is_scsi(rq
) && !(flags
& SCMD_INITIALIZED
)) {
1146 flags
|= SCMD_INITIALIZED
;
1147 scsi_initialize_rq(rq
);
1150 jiffies_at_alloc
= cmd
->jiffies_at_alloc
;
1151 retries
= cmd
->retries
;
1152 in_flight
= test_bit(SCMD_STATE_INFLIGHT
, &cmd
->state
);
1154 * Zero out the cmd, except for the embedded scsi_request. Only clear
1155 * the driver-private command data if the LLD does not supply a
1156 * function to initialize that data.
1158 to_clear
= sizeof(*cmd
) - sizeof(cmd
->req
);
1159 if (!dev
->host
->hostt
->init_cmd_priv
)
1160 to_clear
+= dev
->host
->hostt
->cmd_size
;
1161 memset((char *)cmd
+ sizeof(cmd
->req
), 0, to_clear
);
1164 cmd
->sense_buffer
= buf
;
1165 cmd
->prot_sdb
= prot
;
1167 INIT_DELAYED_WORK(&cmd
->abort_work
, scmd_eh_abort_handler
);
1168 cmd
->jiffies_at_alloc
= jiffies_at_alloc
;
1169 cmd
->retries
= retries
;
1171 __set_bit(SCMD_STATE_INFLIGHT
, &cmd
->state
);
1175 static blk_status_t
scsi_setup_scsi_cmnd(struct scsi_device
*sdev
,
1176 struct request
*req
)
1178 struct scsi_cmnd
*cmd
= blk_mq_rq_to_pdu(req
);
1181 * Passthrough requests may transfer data, in which case they must
1182 * a bio attached to them. Or they might contain a SCSI command
1183 * that does not transfer data, in which case they may optionally
1184 * submit a request without an attached bio.
1187 blk_status_t ret
= scsi_alloc_sgtables(cmd
);
1188 if (unlikely(ret
!= BLK_STS_OK
))
1191 BUG_ON(blk_rq_bytes(req
));
1193 memset(&cmd
->sdb
, 0, sizeof(cmd
->sdb
));
1196 cmd
->cmd_len
= scsi_req(req
)->cmd_len
;
1197 if (cmd
->cmd_len
== 0)
1198 cmd
->cmd_len
= scsi_command_size(cmd
->cmnd
);
1199 cmd
->cmnd
= scsi_req(req
)->cmd
;
1200 cmd
->transfersize
= blk_rq_bytes(req
);
1201 cmd
->allowed
= scsi_req(req
)->retries
;
1206 scsi_device_state_check(struct scsi_device
*sdev
, struct request
*req
)
1208 switch (sdev
->sdev_state
) {
1210 case SDEV_TRANSPORT_OFFLINE
:
1212 * If the device is offline we refuse to process any
1213 * commands. The device must be brought online
1214 * before trying any recovery commands.
1216 if (!sdev
->offline_already
) {
1217 sdev
->offline_already
= true;
1218 sdev_printk(KERN_ERR
, sdev
,
1219 "rejecting I/O to offline device\n");
1221 return BLK_STS_IOERR
;
1224 * If the device is fully deleted, we refuse to
1225 * process any commands as well.
1227 sdev_printk(KERN_ERR
, sdev
,
1228 "rejecting I/O to dead device\n");
1229 return BLK_STS_IOERR
;
1231 case SDEV_CREATED_BLOCK
:
1232 return BLK_STS_RESOURCE
;
1235 * If the devices is blocked we defer normal commands.
1237 if (req
&& !(req
->rq_flags
& RQF_PREEMPT
))
1238 return BLK_STS_RESOURCE
;
1242 * For any other not fully online state we only allow
1243 * special commands. In particular any user initiated
1244 * command is not allowed.
1246 if (req
&& !(req
->rq_flags
& RQF_PREEMPT
))
1247 return BLK_STS_IOERR
;
1253 * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else
1256 * Called with the queue_lock held.
1258 static inline int scsi_dev_queue_ready(struct request_queue
*q
,
1259 struct scsi_device
*sdev
)
1263 busy
= atomic_inc_return(&sdev
->device_busy
) - 1;
1264 if (atomic_read(&sdev
->device_blocked
)) {
1269 * unblock after device_blocked iterates to zero
1271 if (atomic_dec_return(&sdev
->device_blocked
) > 0)
1273 SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO
, sdev
,
1274 "unblocking device at zero depth\n"));
1277 if (busy
>= sdev
->queue_depth
)
1282 atomic_dec(&sdev
->device_busy
);
1287 * scsi_target_queue_ready: checks if there we can send commands to target
1288 * @sdev: scsi device on starget to check.
1290 static inline int scsi_target_queue_ready(struct Scsi_Host
*shost
,
1291 struct scsi_device
*sdev
)
1293 struct scsi_target
*starget
= scsi_target(sdev
);
1296 if (starget
->single_lun
) {
1297 spin_lock_irq(shost
->host_lock
);
1298 if (starget
->starget_sdev_user
&&
1299 starget
->starget_sdev_user
!= sdev
) {
1300 spin_unlock_irq(shost
->host_lock
);
1303 starget
->starget_sdev_user
= sdev
;
1304 spin_unlock_irq(shost
->host_lock
);
1307 if (starget
->can_queue
<= 0)
1310 busy
= atomic_inc_return(&starget
->target_busy
) - 1;
1311 if (atomic_read(&starget
->target_blocked
) > 0) {
1316 * unblock after target_blocked iterates to zero
1318 if (atomic_dec_return(&starget
->target_blocked
) > 0)
1321 SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO
, starget
,
1322 "unblocking target at zero depth\n"));
1325 if (busy
>= starget
->can_queue
)
1331 spin_lock_irq(shost
->host_lock
);
1332 list_move_tail(&sdev
->starved_entry
, &shost
->starved_list
);
1333 spin_unlock_irq(shost
->host_lock
);
1335 if (starget
->can_queue
> 0)
1336 atomic_dec(&starget
->target_busy
);
1341 * scsi_host_queue_ready: if we can send requests to shost, return 1 else
1342 * return 0. We must end up running the queue again whenever 0 is
1343 * returned, else IO can hang.
1345 static inline int scsi_host_queue_ready(struct request_queue
*q
,
1346 struct Scsi_Host
*shost
,
1347 struct scsi_device
*sdev
,
1348 struct scsi_cmnd
*cmd
)
1350 if (scsi_host_in_recovery(shost
))
1353 if (atomic_read(&shost
->host_blocked
) > 0) {
1354 if (scsi_host_busy(shost
) > 0)
1358 * unblock after host_blocked iterates to zero
1360 if (atomic_dec_return(&shost
->host_blocked
) > 0)
1364 shost_printk(KERN_INFO
, shost
,
1365 "unblocking host at zero depth\n"));
1368 if (shost
->host_self_blocked
)
1371 /* We're OK to process the command, so we can't be starved */
1372 if (!list_empty(&sdev
->starved_entry
)) {
1373 spin_lock_irq(shost
->host_lock
);
1374 if (!list_empty(&sdev
->starved_entry
))
1375 list_del_init(&sdev
->starved_entry
);
1376 spin_unlock_irq(shost
->host_lock
);
1379 __set_bit(SCMD_STATE_INFLIGHT
, &cmd
->state
);
1384 spin_lock_irq(shost
->host_lock
);
1385 if (list_empty(&sdev
->starved_entry
))
1386 list_add_tail(&sdev
->starved_entry
, &shost
->starved_list
);
1387 spin_unlock_irq(shost
->host_lock
);
1389 scsi_dec_host_busy(shost
, cmd
);
1394 * Busy state exporting function for request stacking drivers.
1396 * For efficiency, no lock is taken to check the busy state of
1397 * shost/starget/sdev, since the returned value is not guaranteed and
1398 * may be changed after request stacking drivers call the function,
1399 * regardless of taking lock or not.
1401 * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi
1402 * needs to return 'not busy'. Otherwise, request stacking drivers
1403 * may hold requests forever.
1405 static bool scsi_mq_lld_busy(struct request_queue
*q
)
1407 struct scsi_device
*sdev
= q
->queuedata
;
1408 struct Scsi_Host
*shost
;
1410 if (blk_queue_dying(q
))
1416 * Ignore host/starget busy state.
1417 * Since block layer does not have a concept of fairness across
1418 * multiple queues, congestion of host/starget needs to be handled
1421 if (scsi_host_in_recovery(shost
) || scsi_device_is_busy(sdev
))
1427 static void scsi_softirq_done(struct request
*rq
)
1429 struct scsi_cmnd
*cmd
= blk_mq_rq_to_pdu(rq
);
1432 INIT_LIST_HEAD(&cmd
->eh_entry
);
1434 atomic_inc(&cmd
->device
->iodone_cnt
);
1436 atomic_inc(&cmd
->device
->ioerr_cnt
);
1438 disposition
= scsi_decide_disposition(cmd
);
1439 if (disposition
!= SUCCESS
&& scsi_cmd_runtime_exceeced(cmd
))
1440 disposition
= SUCCESS
;
1442 scsi_log_completion(cmd
, disposition
);
1444 switch (disposition
) {
1446 scsi_finish_command(cmd
);
1449 scsi_queue_insert(cmd
, SCSI_MLQUEUE_EH_RETRY
);
1451 case ADD_TO_MLQUEUE
:
1452 scsi_queue_insert(cmd
, SCSI_MLQUEUE_DEVICE_BUSY
);
1455 scsi_eh_scmd_add(cmd
);
1461 * scsi_dispatch_cmd - Dispatch a command to the low-level driver.
1462 * @cmd: command block we are dispatching.
1464 * Return: nonzero return request was rejected and device's queue needs to be
1467 static int scsi_dispatch_cmd(struct scsi_cmnd
*cmd
)
1469 struct Scsi_Host
*host
= cmd
->device
->host
;
1472 atomic_inc(&cmd
->device
->iorequest_cnt
);
1474 /* check if the device is still usable */
1475 if (unlikely(cmd
->device
->sdev_state
== SDEV_DEL
)) {
1476 /* in SDEV_DEL we error all commands. DID_NO_CONNECT
1477 * returns an immediate error upwards, and signals
1478 * that the device is no longer present */
1479 cmd
->result
= DID_NO_CONNECT
<< 16;
1483 /* Check to see if the scsi lld made this device blocked. */
1484 if (unlikely(scsi_device_blocked(cmd
->device
))) {
1486 * in blocked state, the command is just put back on
1487 * the device queue. The suspend state has already
1488 * blocked the queue so future requests should not
1489 * occur until the device transitions out of the
1492 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO
, cmd
,
1493 "queuecommand : device blocked\n"));
1494 return SCSI_MLQUEUE_DEVICE_BUSY
;
1497 /* Store the LUN value in cmnd, if needed. */
1498 if (cmd
->device
->lun_in_cdb
)
1499 cmd
->cmnd
[1] = (cmd
->cmnd
[1] & 0x1f) |
1500 (cmd
->device
->lun
<< 5 & 0xe0);
1505 * Before we queue this command, check if the command
1506 * length exceeds what the host adapter can handle.
1508 if (cmd
->cmd_len
> cmd
->device
->host
->max_cmd_len
) {
1509 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO
, cmd
,
1510 "queuecommand : command too long. "
1511 "cdb_size=%d host->max_cmd_len=%d\n",
1512 cmd
->cmd_len
, cmd
->device
->host
->max_cmd_len
));
1513 cmd
->result
= (DID_ABORT
<< 16);
1517 if (unlikely(host
->shost_state
== SHOST_DEL
)) {
1518 cmd
->result
= (DID_NO_CONNECT
<< 16);
1523 trace_scsi_dispatch_cmd_start(cmd
);
1524 rtn
= host
->hostt
->queuecommand(host
, cmd
);
1526 trace_scsi_dispatch_cmd_error(cmd
, rtn
);
1527 if (rtn
!= SCSI_MLQUEUE_DEVICE_BUSY
&&
1528 rtn
!= SCSI_MLQUEUE_TARGET_BUSY
)
1529 rtn
= SCSI_MLQUEUE_HOST_BUSY
;
1531 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO
, cmd
,
1532 "queuecommand : request rejected\n"));
1537 cmd
->scsi_done(cmd
);
1541 /* Size in bytes of the sg-list stored in the scsi-mq command-private data. */
1542 static unsigned int scsi_mq_inline_sgl_size(struct Scsi_Host
*shost
)
1544 return min_t(unsigned int, shost
->sg_tablesize
, SCSI_INLINE_SG_CNT
) *
1545 sizeof(struct scatterlist
);
1548 static blk_status_t
scsi_prepare_cmd(struct request
*req
)
1550 struct scsi_cmnd
*cmd
= blk_mq_rq_to_pdu(req
);
1551 struct scsi_device
*sdev
= req
->q
->queuedata
;
1552 struct Scsi_Host
*shost
= sdev
->host
;
1553 struct scatterlist
*sg
;
1555 scsi_init_command(sdev
, cmd
);
1558 cmd
->tag
= req
->tag
;
1559 cmd
->prot_op
= SCSI_PROT_NORMAL
;
1560 if (blk_rq_bytes(req
))
1561 cmd
->sc_data_direction
= rq_dma_dir(req
);
1563 cmd
->sc_data_direction
= DMA_NONE
;
1565 sg
= (void *)cmd
+ sizeof(struct scsi_cmnd
) + shost
->hostt
->cmd_size
;
1566 cmd
->sdb
.table
.sgl
= sg
;
1568 if (scsi_host_get_prot(shost
)) {
1569 memset(cmd
->prot_sdb
, 0, sizeof(struct scsi_data_buffer
));
1571 cmd
->prot_sdb
->table
.sgl
=
1572 (struct scatterlist
*)(cmd
->prot_sdb
+ 1);
1576 * Special handling for passthrough commands, which don't go to the ULP
1579 if (blk_rq_is_scsi(req
))
1580 return scsi_setup_scsi_cmnd(sdev
, req
);
1582 if (sdev
->handler
&& sdev
->handler
->prep_fn
) {
1583 blk_status_t ret
= sdev
->handler
->prep_fn(sdev
, req
);
1585 if (ret
!= BLK_STS_OK
)
1589 cmd
->cmnd
= scsi_req(req
)->cmd
= scsi_req(req
)->__cmd
;
1590 memset(cmd
->cmnd
, 0, BLK_MAX_CDB
);
1591 return scsi_cmd_to_driver(cmd
)->init_command(cmd
);
1594 static void scsi_mq_done(struct scsi_cmnd
*cmd
)
1596 if (unlikely(blk_should_fake_timeout(cmd
->request
->q
)))
1598 if (unlikely(test_and_set_bit(SCMD_STATE_COMPLETE
, &cmd
->state
)))
1600 trace_scsi_dispatch_cmd_done(cmd
);
1601 blk_mq_complete_request(cmd
->request
);
1604 static void scsi_mq_put_budget(struct request_queue
*q
)
1606 struct scsi_device
*sdev
= q
->queuedata
;
1608 atomic_dec(&sdev
->device_busy
);
1611 static bool scsi_mq_get_budget(struct request_queue
*q
)
1613 struct scsi_device
*sdev
= q
->queuedata
;
1615 if (scsi_dev_queue_ready(q
, sdev
))
1618 atomic_inc(&sdev
->restarts
);
1621 * Orders atomic_inc(&sdev->restarts) and atomic_read(&sdev->device_busy).
1622 * .restarts must be incremented before .device_busy is read because the
1623 * code in scsi_run_queue_async() depends on the order of these operations.
1625 smp_mb__after_atomic();
1628 * If all in-flight requests originated from this LUN are completed
1629 * before reading .device_busy, sdev->device_busy will be observed as
1630 * zero, then blk_mq_delay_run_hw_queues() will dispatch this request
1631 * soon. Otherwise, completion of one of these requests will observe
1632 * the .restarts flag, and the request queue will be run for handling
1633 * this request, see scsi_end_request().
1635 if (unlikely(atomic_read(&sdev
->device_busy
) == 0 &&
1636 !scsi_device_blocked(sdev
)))
1637 blk_mq_delay_run_hw_queues(sdev
->request_queue
, SCSI_QUEUE_DELAY
);
1641 static blk_status_t
scsi_queue_rq(struct blk_mq_hw_ctx
*hctx
,
1642 const struct blk_mq_queue_data
*bd
)
1644 struct request
*req
= bd
->rq
;
1645 struct request_queue
*q
= req
->q
;
1646 struct scsi_device
*sdev
= q
->queuedata
;
1647 struct Scsi_Host
*shost
= sdev
->host
;
1648 struct scsi_cmnd
*cmd
= blk_mq_rq_to_pdu(req
);
1653 * If the device is not in running state we will reject some or all
1656 if (unlikely(sdev
->sdev_state
!= SDEV_RUNNING
)) {
1657 ret
= scsi_device_state_check(sdev
, req
);
1658 if (ret
!= BLK_STS_OK
)
1659 goto out_put_budget
;
1662 ret
= BLK_STS_RESOURCE
;
1663 if (!scsi_target_queue_ready(shost
, sdev
))
1664 goto out_put_budget
;
1665 if (!scsi_host_queue_ready(q
, shost
, sdev
, cmd
))
1666 goto out_dec_target_busy
;
1668 if (!(req
->rq_flags
& RQF_DONTPREP
)) {
1669 ret
= scsi_prepare_cmd(req
);
1670 if (ret
!= BLK_STS_OK
)
1671 goto out_dec_host_busy
;
1672 req
->rq_flags
|= RQF_DONTPREP
;
1674 clear_bit(SCMD_STATE_COMPLETE
, &cmd
->state
);
1677 cmd
->flags
&= SCMD_PRESERVED_FLAGS
;
1678 if (sdev
->simple_tags
)
1679 cmd
->flags
|= SCMD_TAGGED
;
1681 cmd
->flags
|= SCMD_LAST
;
1683 scsi_set_resid(cmd
, 0);
1684 memset(cmd
->sense_buffer
, 0, SCSI_SENSE_BUFFERSIZE
);
1685 cmd
->scsi_done
= scsi_mq_done
;
1687 blk_mq_start_request(req
);
1688 reason
= scsi_dispatch_cmd(cmd
);
1690 scsi_set_blocked(cmd
, reason
);
1691 ret
= BLK_STS_RESOURCE
;
1692 goto out_dec_host_busy
;
1698 scsi_dec_host_busy(shost
, cmd
);
1699 out_dec_target_busy
:
1700 if (scsi_target(sdev
)->can_queue
> 0)
1701 atomic_dec(&scsi_target(sdev
)->target_busy
);
1703 scsi_mq_put_budget(q
);
1707 case BLK_STS_RESOURCE
:
1708 case BLK_STS_ZONE_RESOURCE
:
1709 if (scsi_device_blocked(sdev
))
1710 ret
= BLK_STS_DEV_RESOURCE
;
1713 scsi_req(req
)->result
= DID_BUS_BUSY
<< 16;
1714 if (req
->rq_flags
& RQF_DONTPREP
)
1715 scsi_mq_uninit_cmd(cmd
);
1718 if (unlikely(!scsi_device_online(sdev
)))
1719 scsi_req(req
)->result
= DID_NO_CONNECT
<< 16;
1721 scsi_req(req
)->result
= DID_ERROR
<< 16;
1723 * Make sure to release all allocated resources when
1724 * we hit an error, as we will never see this command
1727 if (req
->rq_flags
& RQF_DONTPREP
)
1728 scsi_mq_uninit_cmd(cmd
);
1729 scsi_run_queue_async(sdev
);
1735 static enum blk_eh_timer_return
scsi_timeout(struct request
*req
,
1739 return BLK_EH_RESET_TIMER
;
1740 return scsi_times_out(req
);
1743 static int scsi_mq_init_request(struct blk_mq_tag_set
*set
, struct request
*rq
,
1744 unsigned int hctx_idx
, unsigned int numa_node
)
1746 struct Scsi_Host
*shost
= set
->driver_data
;
1747 const bool unchecked_isa_dma
= shost
->unchecked_isa_dma
;
1748 struct scsi_cmnd
*cmd
= blk_mq_rq_to_pdu(rq
);
1749 struct scatterlist
*sg
;
1752 if (unchecked_isa_dma
)
1753 cmd
->flags
|= SCMD_UNCHECKED_ISA_DMA
;
1754 cmd
->sense_buffer
= scsi_alloc_sense_buffer(unchecked_isa_dma
,
1755 GFP_KERNEL
, numa_node
);
1756 if (!cmd
->sense_buffer
)
1758 cmd
->req
.sense
= cmd
->sense_buffer
;
1760 if (scsi_host_get_prot(shost
)) {
1761 sg
= (void *)cmd
+ sizeof(struct scsi_cmnd
) +
1762 shost
->hostt
->cmd_size
;
1763 cmd
->prot_sdb
= (void *)sg
+ scsi_mq_inline_sgl_size(shost
);
1766 if (shost
->hostt
->init_cmd_priv
) {
1767 ret
= shost
->hostt
->init_cmd_priv(shost
, cmd
);
1769 scsi_free_sense_buffer(unchecked_isa_dma
,
1776 static void scsi_mq_exit_request(struct blk_mq_tag_set
*set
, struct request
*rq
,
1777 unsigned int hctx_idx
)
1779 struct Scsi_Host
*shost
= set
->driver_data
;
1780 struct scsi_cmnd
*cmd
= blk_mq_rq_to_pdu(rq
);
1782 if (shost
->hostt
->exit_cmd_priv
)
1783 shost
->hostt
->exit_cmd_priv(shost
, cmd
);
1784 scsi_free_sense_buffer(cmd
->flags
& SCMD_UNCHECKED_ISA_DMA
,
1788 static int scsi_map_queues(struct blk_mq_tag_set
*set
)
1790 struct Scsi_Host
*shost
= container_of(set
, struct Scsi_Host
, tag_set
);
1792 if (shost
->hostt
->map_queues
)
1793 return shost
->hostt
->map_queues(shost
);
1794 return blk_mq_map_queues(&set
->map
[HCTX_TYPE_DEFAULT
]);
1797 void __scsi_init_queue(struct Scsi_Host
*shost
, struct request_queue
*q
)
1799 struct device
*dev
= shost
->dma_dev
;
1802 * this limit is imposed by hardware restrictions
1804 blk_queue_max_segments(q
, min_t(unsigned short, shost
->sg_tablesize
,
1807 if (scsi_host_prot_dma(shost
)) {
1808 shost
->sg_prot_tablesize
=
1809 min_not_zero(shost
->sg_prot_tablesize
,
1810 (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS
);
1811 BUG_ON(shost
->sg_prot_tablesize
< shost
->sg_tablesize
);
1812 blk_queue_max_integrity_segments(q
, shost
->sg_prot_tablesize
);
1815 if (dev
->dma_mask
) {
1816 shost
->max_sectors
= min_t(unsigned int, shost
->max_sectors
,
1817 dma_max_mapping_size(dev
) >> SECTOR_SHIFT
);
1819 blk_queue_max_hw_sectors(q
, shost
->max_sectors
);
1820 if (shost
->unchecked_isa_dma
)
1821 blk_queue_bounce_limit(q
, BLK_BOUNCE_ISA
);
1822 blk_queue_segment_boundary(q
, shost
->dma_boundary
);
1823 dma_set_seg_boundary(dev
, shost
->dma_boundary
);
1825 blk_queue_max_segment_size(q
, shost
->max_segment_size
);
1826 blk_queue_virt_boundary(q
, shost
->virt_boundary_mask
);
1827 dma_set_max_seg_size(dev
, queue_max_segment_size(q
));
1830 * Set a reasonable default alignment: The larger of 32-byte (dword),
1831 * which is a common minimum for HBAs, and the minimum DMA alignment,
1832 * which is set by the platform.
1834 * Devices that require a bigger alignment can increase it later.
1836 blk_queue_dma_alignment(q
, max(4, dma_get_cache_alignment()) - 1);
1838 EXPORT_SYMBOL_GPL(__scsi_init_queue
);
1840 static const struct blk_mq_ops scsi_mq_ops_no_commit
= {
1841 .get_budget
= scsi_mq_get_budget
,
1842 .put_budget
= scsi_mq_put_budget
,
1843 .queue_rq
= scsi_queue_rq
,
1844 .complete
= scsi_softirq_done
,
1845 .timeout
= scsi_timeout
,
1846 #ifdef CONFIG_BLK_DEBUG_FS
1847 .show_rq
= scsi_show_rq
,
1849 .init_request
= scsi_mq_init_request
,
1850 .exit_request
= scsi_mq_exit_request
,
1851 .initialize_rq_fn
= scsi_initialize_rq
,
1852 .cleanup_rq
= scsi_cleanup_rq
,
1853 .busy
= scsi_mq_lld_busy
,
1854 .map_queues
= scsi_map_queues
,
1858 static void scsi_commit_rqs(struct blk_mq_hw_ctx
*hctx
)
1860 struct request_queue
*q
= hctx
->queue
;
1861 struct scsi_device
*sdev
= q
->queuedata
;
1862 struct Scsi_Host
*shost
= sdev
->host
;
1864 shost
->hostt
->commit_rqs(shost
, hctx
->queue_num
);
1867 static const struct blk_mq_ops scsi_mq_ops
= {
1868 .get_budget
= scsi_mq_get_budget
,
1869 .put_budget
= scsi_mq_put_budget
,
1870 .queue_rq
= scsi_queue_rq
,
1871 .commit_rqs
= scsi_commit_rqs
,
1872 .complete
= scsi_softirq_done
,
1873 .timeout
= scsi_timeout
,
1874 #ifdef CONFIG_BLK_DEBUG_FS
1875 .show_rq
= scsi_show_rq
,
1877 .init_request
= scsi_mq_init_request
,
1878 .exit_request
= scsi_mq_exit_request
,
1879 .initialize_rq_fn
= scsi_initialize_rq
,
1880 .cleanup_rq
= scsi_cleanup_rq
,
1881 .busy
= scsi_mq_lld_busy
,
1882 .map_queues
= scsi_map_queues
,
1885 struct request_queue
*scsi_mq_alloc_queue(struct scsi_device
*sdev
)
1887 sdev
->request_queue
= blk_mq_init_queue(&sdev
->host
->tag_set
);
1888 if (IS_ERR(sdev
->request_queue
))
1891 sdev
->request_queue
->queuedata
= sdev
;
1892 __scsi_init_queue(sdev
->host
, sdev
->request_queue
);
1893 blk_queue_flag_set(QUEUE_FLAG_SCSI_PASSTHROUGH
, sdev
->request_queue
);
1894 return sdev
->request_queue
;
1897 int scsi_mq_setup_tags(struct Scsi_Host
*shost
)
1899 unsigned int cmd_size
, sgl_size
;
1900 struct blk_mq_tag_set
*tag_set
= &shost
->tag_set
;
1902 sgl_size
= max_t(unsigned int, sizeof(struct scatterlist
),
1903 scsi_mq_inline_sgl_size(shost
));
1904 cmd_size
= sizeof(struct scsi_cmnd
) + shost
->hostt
->cmd_size
+ sgl_size
;
1905 if (scsi_host_get_prot(shost
))
1906 cmd_size
+= sizeof(struct scsi_data_buffer
) +
1907 sizeof(struct scatterlist
) * SCSI_INLINE_PROT_SG_CNT
;
1909 memset(tag_set
, 0, sizeof(*tag_set
));
1910 if (shost
->hostt
->commit_rqs
)
1911 tag_set
->ops
= &scsi_mq_ops
;
1913 tag_set
->ops
= &scsi_mq_ops_no_commit
;
1914 tag_set
->nr_hw_queues
= shost
->nr_hw_queues
? : 1;
1915 tag_set
->queue_depth
= shost
->can_queue
;
1916 tag_set
->cmd_size
= cmd_size
;
1917 tag_set
->numa_node
= NUMA_NO_NODE
;
1918 tag_set
->flags
= BLK_MQ_F_SHOULD_MERGE
;
1920 BLK_ALLOC_POLICY_TO_MQ_FLAG(shost
->hostt
->tag_alloc_policy
);
1921 tag_set
->driver_data
= shost
;
1922 if (shost
->host_tagset
)
1923 tag_set
->flags
|= BLK_MQ_F_TAG_HCTX_SHARED
;
1925 return blk_mq_alloc_tag_set(tag_set
);
1928 void scsi_mq_destroy_tags(struct Scsi_Host
*shost
)
1930 blk_mq_free_tag_set(&shost
->tag_set
);
1934 * scsi_device_from_queue - return sdev associated with a request_queue
1935 * @q: The request queue to return the sdev from
1937 * Return the sdev associated with a request queue or NULL if the
1938 * request_queue does not reference a SCSI device.
1940 struct scsi_device
*scsi_device_from_queue(struct request_queue
*q
)
1942 struct scsi_device
*sdev
= NULL
;
1944 if (q
->mq_ops
== &scsi_mq_ops_no_commit
||
1945 q
->mq_ops
== &scsi_mq_ops
)
1946 sdev
= q
->queuedata
;
1947 if (!sdev
|| !get_device(&sdev
->sdev_gendev
))
1954 * scsi_block_requests - Utility function used by low-level drivers to prevent
1955 * further commands from being queued to the device.
1956 * @shost: host in question
1958 * There is no timer nor any other means by which the requests get unblocked
1959 * other than the low-level driver calling scsi_unblock_requests().
1961 void scsi_block_requests(struct Scsi_Host
*shost
)
1963 shost
->host_self_blocked
= 1;
1965 EXPORT_SYMBOL(scsi_block_requests
);
1968 * scsi_unblock_requests - Utility function used by low-level drivers to allow
1969 * further commands to be queued to the device.
1970 * @shost: host in question
1972 * There is no timer nor any other means by which the requests get unblocked
1973 * other than the low-level driver calling scsi_unblock_requests(). This is done
1974 * as an API function so that changes to the internals of the scsi mid-layer
1975 * won't require wholesale changes to drivers that use this feature.
1977 void scsi_unblock_requests(struct Scsi_Host
*shost
)
1979 shost
->host_self_blocked
= 0;
1980 scsi_run_host_queues(shost
);
1982 EXPORT_SYMBOL(scsi_unblock_requests
);
1984 void scsi_exit_queue(void)
1986 kmem_cache_destroy(scsi_sense_cache
);
1987 kmem_cache_destroy(scsi_sense_isadma_cache
);
1991 * scsi_mode_select - issue a mode select
1992 * @sdev: SCSI device to be queried
1993 * @pf: Page format bit (1 == standard, 0 == vendor specific)
1994 * @sp: Save page bit (0 == don't save, 1 == save)
1995 * @modepage: mode page being requested
1996 * @buffer: request buffer (may not be smaller than eight bytes)
1997 * @len: length of request buffer.
1998 * @timeout: command timeout
1999 * @retries: number of retries before failing
2000 * @data: returns a structure abstracting the mode header data
2001 * @sshdr: place to put sense data (or NULL if no sense to be collected).
2002 * must be SCSI_SENSE_BUFFERSIZE big.
2004 * Returns zero if successful; negative error number or scsi
2009 scsi_mode_select(struct scsi_device
*sdev
, int pf
, int sp
, int modepage
,
2010 unsigned char *buffer
, int len
, int timeout
, int retries
,
2011 struct scsi_mode_data
*data
, struct scsi_sense_hdr
*sshdr
)
2013 unsigned char cmd
[10];
2014 unsigned char *real_buffer
;
2017 memset(cmd
, 0, sizeof(cmd
));
2018 cmd
[1] = (pf
? 0x10 : 0) | (sp
? 0x01 : 0);
2020 if (sdev
->use_10_for_ms
) {
2023 real_buffer
= kmalloc(8 + len
, GFP_KERNEL
);
2026 memcpy(real_buffer
+ 8, buffer
, len
);
2030 real_buffer
[2] = data
->medium_type
;
2031 real_buffer
[3] = data
->device_specific
;
2032 real_buffer
[4] = data
->longlba
? 0x01 : 0;
2034 real_buffer
[6] = data
->block_descriptor_length
>> 8;
2035 real_buffer
[7] = data
->block_descriptor_length
;
2037 cmd
[0] = MODE_SELECT_10
;
2041 if (len
> 255 || data
->block_descriptor_length
> 255 ||
2045 real_buffer
= kmalloc(4 + len
, GFP_KERNEL
);
2048 memcpy(real_buffer
+ 4, buffer
, len
);
2051 real_buffer
[1] = data
->medium_type
;
2052 real_buffer
[2] = data
->device_specific
;
2053 real_buffer
[3] = data
->block_descriptor_length
;
2055 cmd
[0] = MODE_SELECT
;
2059 ret
= scsi_execute_req(sdev
, cmd
, DMA_TO_DEVICE
, real_buffer
, len
,
2060 sshdr
, timeout
, retries
, NULL
);
2064 EXPORT_SYMBOL_GPL(scsi_mode_select
);
2067 * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary.
2068 * @sdev: SCSI device to be queried
2069 * @dbd: set if mode sense will allow block descriptors to be returned
2070 * @modepage: mode page being requested
2071 * @buffer: request buffer (may not be smaller than eight bytes)
2072 * @len: length of request buffer.
2073 * @timeout: command timeout
2074 * @retries: number of retries before failing
2075 * @data: returns a structure abstracting the mode header data
2076 * @sshdr: place to put sense data (or NULL if no sense to be collected).
2077 * must be SCSI_SENSE_BUFFERSIZE big.
2079 * Returns zero if unsuccessful, or the header offset (either 4
2080 * or 8 depending on whether a six or ten byte command was
2081 * issued) if successful.
2084 scsi_mode_sense(struct scsi_device
*sdev
, int dbd
, int modepage
,
2085 unsigned char *buffer
, int len
, int timeout
, int retries
,
2086 struct scsi_mode_data
*data
, struct scsi_sense_hdr
*sshdr
)
2088 unsigned char cmd
[12];
2091 int result
, retry_count
= retries
;
2092 struct scsi_sense_hdr my_sshdr
;
2094 memset(data
, 0, sizeof(*data
));
2095 memset(&cmd
[0], 0, 12);
2097 dbd
= sdev
->set_dbd_for_ms
? 8 : dbd
;
2098 cmd
[1] = dbd
& 0x18; /* allows DBD and LLBA bits */
2101 /* caller might not be interested in sense, but we need it */
2106 use_10_for_ms
= sdev
->use_10_for_ms
;
2108 if (use_10_for_ms
) {
2112 cmd
[0] = MODE_SENSE_10
;
2119 cmd
[0] = MODE_SENSE
;
2124 memset(buffer
, 0, len
);
2126 result
= scsi_execute_req(sdev
, cmd
, DMA_FROM_DEVICE
, buffer
, len
,
2127 sshdr
, timeout
, retries
, NULL
);
2129 /* This code looks awful: what it's doing is making sure an
2130 * ILLEGAL REQUEST sense return identifies the actual command
2131 * byte as the problem. MODE_SENSE commands can return
2132 * ILLEGAL REQUEST if the code page isn't supported */
2134 if (use_10_for_ms
&& !scsi_status_is_good(result
) &&
2135 driver_byte(result
) == DRIVER_SENSE
) {
2136 if (scsi_sense_valid(sshdr
)) {
2137 if ((sshdr
->sense_key
== ILLEGAL_REQUEST
) &&
2138 (sshdr
->asc
== 0x20) && (sshdr
->ascq
== 0)) {
2140 * Invalid command operation code
2142 sdev
->use_10_for_ms
= 0;
2148 if (scsi_status_is_good(result
)) {
2149 if (unlikely(buffer
[0] == 0x86 && buffer
[1] == 0x0b &&
2150 (modepage
== 6 || modepage
== 8))) {
2151 /* Initio breakage? */
2154 data
->medium_type
= 0;
2155 data
->device_specific
= 0;
2157 data
->block_descriptor_length
= 0;
2158 } else if (use_10_for_ms
) {
2159 data
->length
= buffer
[0]*256 + buffer
[1] + 2;
2160 data
->medium_type
= buffer
[2];
2161 data
->device_specific
= buffer
[3];
2162 data
->longlba
= buffer
[4] & 0x01;
2163 data
->block_descriptor_length
= buffer
[6]*256
2166 data
->length
= buffer
[0] + 1;
2167 data
->medium_type
= buffer
[1];
2168 data
->device_specific
= buffer
[2];
2169 data
->block_descriptor_length
= buffer
[3];
2171 data
->header_length
= header_length
;
2172 } else if ((status_byte(result
) == CHECK_CONDITION
) &&
2173 scsi_sense_valid(sshdr
) &&
2174 sshdr
->sense_key
== UNIT_ATTENTION
&& retry_count
) {
2181 EXPORT_SYMBOL(scsi_mode_sense
);
2184 * scsi_test_unit_ready - test if unit is ready
2185 * @sdev: scsi device to change the state of.
2186 * @timeout: command timeout
2187 * @retries: number of retries before failing
2188 * @sshdr: outpout pointer for decoded sense information.
2190 * Returns zero if unsuccessful or an error if TUR failed. For
2191 * removable media, UNIT_ATTENTION sets ->changed flag.
2194 scsi_test_unit_ready(struct scsi_device
*sdev
, int timeout
, int retries
,
2195 struct scsi_sense_hdr
*sshdr
)
2198 TEST_UNIT_READY
, 0, 0, 0, 0, 0,
2202 /* try to eat the UNIT_ATTENTION if there are enough retries */
2204 result
= scsi_execute_req(sdev
, cmd
, DMA_NONE
, NULL
, 0, sshdr
,
2206 if (sdev
->removable
&& scsi_sense_valid(sshdr
) &&
2207 sshdr
->sense_key
== UNIT_ATTENTION
)
2209 } while (scsi_sense_valid(sshdr
) &&
2210 sshdr
->sense_key
== UNIT_ATTENTION
&& --retries
);
2214 EXPORT_SYMBOL(scsi_test_unit_ready
);
2217 * scsi_device_set_state - Take the given device through the device state model.
2218 * @sdev: scsi device to change the state of.
2219 * @state: state to change to.
2221 * Returns zero if successful or an error if the requested
2222 * transition is illegal.
2225 scsi_device_set_state(struct scsi_device
*sdev
, enum scsi_device_state state
)
2227 enum scsi_device_state oldstate
= sdev
->sdev_state
;
2229 if (state
== oldstate
)
2235 case SDEV_CREATED_BLOCK
:
2246 case SDEV_TRANSPORT_OFFLINE
:
2259 case SDEV_TRANSPORT_OFFLINE
:
2267 case SDEV_TRANSPORT_OFFLINE
:
2282 case SDEV_CREATED_BLOCK
:
2291 case SDEV_CREATED_BLOCK
:
2306 case SDEV_TRANSPORT_OFFLINE
:
2318 case SDEV_TRANSPORT_OFFLINE
:
2321 case SDEV_CREATED_BLOCK
:
2329 sdev
->offline_already
= false;
2330 sdev
->sdev_state
= state
;
2334 SCSI_LOG_ERROR_RECOVERY(1,
2335 sdev_printk(KERN_ERR
, sdev
,
2336 "Illegal state transition %s->%s",
2337 scsi_device_state_name(oldstate
),
2338 scsi_device_state_name(state
))
2342 EXPORT_SYMBOL(scsi_device_set_state
);
2345 * scsi_evt_emit - emit a single SCSI device uevent
2346 * @sdev: associated SCSI device
2347 * @evt: event to emit
2349 * Send a single uevent (scsi_event) to the associated scsi_device.
2351 static void scsi_evt_emit(struct scsi_device
*sdev
, struct scsi_event
*evt
)
2356 switch (evt
->evt_type
) {
2357 case SDEV_EVT_MEDIA_CHANGE
:
2358 envp
[idx
++] = "SDEV_MEDIA_CHANGE=1";
2360 case SDEV_EVT_INQUIRY_CHANGE_REPORTED
:
2361 scsi_rescan_device(&sdev
->sdev_gendev
);
2362 envp
[idx
++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED";
2364 case SDEV_EVT_CAPACITY_CHANGE_REPORTED
:
2365 envp
[idx
++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED";
2367 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED
:
2368 envp
[idx
++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED";
2370 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED
:
2371 envp
[idx
++] = "SDEV_UA=MODE_PARAMETERS_CHANGED";
2373 case SDEV_EVT_LUN_CHANGE_REPORTED
:
2374 envp
[idx
++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED";
2376 case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED
:
2377 envp
[idx
++] = "SDEV_UA=ASYMMETRIC_ACCESS_STATE_CHANGED";
2379 case SDEV_EVT_POWER_ON_RESET_OCCURRED
:
2380 envp
[idx
++] = "SDEV_UA=POWER_ON_RESET_OCCURRED";
2389 kobject_uevent_env(&sdev
->sdev_gendev
.kobj
, KOBJ_CHANGE
, envp
);
2393 * scsi_evt_thread - send a uevent for each scsi event
2394 * @work: work struct for scsi_device
2396 * Dispatch queued events to their associated scsi_device kobjects
2399 void scsi_evt_thread(struct work_struct
*work
)
2401 struct scsi_device
*sdev
;
2402 enum scsi_device_event evt_type
;
2403 LIST_HEAD(event_list
);
2405 sdev
= container_of(work
, struct scsi_device
, event_work
);
2407 for (evt_type
= SDEV_EVT_FIRST
; evt_type
<= SDEV_EVT_LAST
; evt_type
++)
2408 if (test_and_clear_bit(evt_type
, sdev
->pending_events
))
2409 sdev_evt_send_simple(sdev
, evt_type
, GFP_KERNEL
);
2412 struct scsi_event
*evt
;
2413 struct list_head
*this, *tmp
;
2414 unsigned long flags
;
2416 spin_lock_irqsave(&sdev
->list_lock
, flags
);
2417 list_splice_init(&sdev
->event_list
, &event_list
);
2418 spin_unlock_irqrestore(&sdev
->list_lock
, flags
);
2420 if (list_empty(&event_list
))
2423 list_for_each_safe(this, tmp
, &event_list
) {
2424 evt
= list_entry(this, struct scsi_event
, node
);
2425 list_del(&evt
->node
);
2426 scsi_evt_emit(sdev
, evt
);
2433 * sdev_evt_send - send asserted event to uevent thread
2434 * @sdev: scsi_device event occurred on
2435 * @evt: event to send
2437 * Assert scsi device event asynchronously.
2439 void sdev_evt_send(struct scsi_device
*sdev
, struct scsi_event
*evt
)
2441 unsigned long flags
;
2444 /* FIXME: currently this check eliminates all media change events
2445 * for polled devices. Need to update to discriminate between AN
2446 * and polled events */
2447 if (!test_bit(evt
->evt_type
, sdev
->supported_events
)) {
2453 spin_lock_irqsave(&sdev
->list_lock
, flags
);
2454 list_add_tail(&evt
->node
, &sdev
->event_list
);
2455 schedule_work(&sdev
->event_work
);
2456 spin_unlock_irqrestore(&sdev
->list_lock
, flags
);
2458 EXPORT_SYMBOL_GPL(sdev_evt_send
);
2461 * sdev_evt_alloc - allocate a new scsi event
2462 * @evt_type: type of event to allocate
2463 * @gfpflags: GFP flags for allocation
2465 * Allocates and returns a new scsi_event.
2467 struct scsi_event
*sdev_evt_alloc(enum scsi_device_event evt_type
,
2470 struct scsi_event
*evt
= kzalloc(sizeof(struct scsi_event
), gfpflags
);
2474 evt
->evt_type
= evt_type
;
2475 INIT_LIST_HEAD(&evt
->node
);
2477 /* evt_type-specific initialization, if any */
2479 case SDEV_EVT_MEDIA_CHANGE
:
2480 case SDEV_EVT_INQUIRY_CHANGE_REPORTED
:
2481 case SDEV_EVT_CAPACITY_CHANGE_REPORTED
:
2482 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED
:
2483 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED
:
2484 case SDEV_EVT_LUN_CHANGE_REPORTED
:
2485 case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED
:
2486 case SDEV_EVT_POWER_ON_RESET_OCCURRED
:
2494 EXPORT_SYMBOL_GPL(sdev_evt_alloc
);
2497 * sdev_evt_send_simple - send asserted event to uevent thread
2498 * @sdev: scsi_device event occurred on
2499 * @evt_type: type of event to send
2500 * @gfpflags: GFP flags for allocation
2502 * Assert scsi device event asynchronously, given an event type.
2504 void sdev_evt_send_simple(struct scsi_device
*sdev
,
2505 enum scsi_device_event evt_type
, gfp_t gfpflags
)
2507 struct scsi_event
*evt
= sdev_evt_alloc(evt_type
, gfpflags
);
2509 sdev_printk(KERN_ERR
, sdev
, "event %d eaten due to OOM\n",
2514 sdev_evt_send(sdev
, evt
);
2516 EXPORT_SYMBOL_GPL(sdev_evt_send_simple
);
2519 * scsi_device_quiesce - Block user issued commands.
2520 * @sdev: scsi device to quiesce.
2522 * This works by trying to transition to the SDEV_QUIESCE state
2523 * (which must be a legal transition). When the device is in this
2524 * state, only special requests will be accepted, all others will
2525 * be deferred. Since special requests may also be requeued requests,
2526 * a successful return doesn't guarantee the device will be
2527 * totally quiescent.
2529 * Must be called with user context, may sleep.
2531 * Returns zero if unsuccessful or an error if not.
2534 scsi_device_quiesce(struct scsi_device
*sdev
)
2536 struct request_queue
*q
= sdev
->request_queue
;
2540 * It is allowed to call scsi_device_quiesce() multiple times from
2541 * the same context but concurrent scsi_device_quiesce() calls are
2544 WARN_ON_ONCE(sdev
->quiesced_by
&& sdev
->quiesced_by
!= current
);
2546 if (sdev
->quiesced_by
== current
)
2551 blk_mq_freeze_queue(q
);
2553 * Ensure that the effect of blk_set_pm_only() will be visible
2554 * for percpu_ref_tryget() callers that occur after the queue
2555 * unfreeze even if the queue was already frozen before this function
2556 * was called. See also https://lwn.net/Articles/573497/.
2559 blk_mq_unfreeze_queue(q
);
2561 mutex_lock(&sdev
->state_mutex
);
2562 err
= scsi_device_set_state(sdev
, SDEV_QUIESCE
);
2564 sdev
->quiesced_by
= current
;
2566 blk_clear_pm_only(q
);
2567 mutex_unlock(&sdev
->state_mutex
);
2571 EXPORT_SYMBOL(scsi_device_quiesce
);
2574 * scsi_device_resume - Restart user issued commands to a quiesced device.
2575 * @sdev: scsi device to resume.
2577 * Moves the device from quiesced back to running and restarts the
2580 * Must be called with user context, may sleep.
2582 void scsi_device_resume(struct scsi_device
*sdev
)
2584 /* check if the device state was mutated prior to resume, and if
2585 * so assume the state is being managed elsewhere (for example
2586 * device deleted during suspend)
2588 mutex_lock(&sdev
->state_mutex
);
2589 if (sdev
->quiesced_by
) {
2590 sdev
->quiesced_by
= NULL
;
2591 blk_clear_pm_only(sdev
->request_queue
);
2593 if (sdev
->sdev_state
== SDEV_QUIESCE
)
2594 scsi_device_set_state(sdev
, SDEV_RUNNING
);
2595 mutex_unlock(&sdev
->state_mutex
);
2597 EXPORT_SYMBOL(scsi_device_resume
);
2600 device_quiesce_fn(struct scsi_device
*sdev
, void *data
)
2602 scsi_device_quiesce(sdev
);
2606 scsi_target_quiesce(struct scsi_target
*starget
)
2608 starget_for_each_device(starget
, NULL
, device_quiesce_fn
);
2610 EXPORT_SYMBOL(scsi_target_quiesce
);
2613 device_resume_fn(struct scsi_device
*sdev
, void *data
)
2615 scsi_device_resume(sdev
);
2619 scsi_target_resume(struct scsi_target
*starget
)
2621 starget_for_each_device(starget
, NULL
, device_resume_fn
);
2623 EXPORT_SYMBOL(scsi_target_resume
);
2626 * scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state
2627 * @sdev: device to block
2629 * Pause SCSI command processing on the specified device. Does not sleep.
2631 * Returns zero if successful or a negative error code upon failure.
2634 * This routine transitions the device to the SDEV_BLOCK state (which must be
2635 * a legal transition). When the device is in this state, command processing
2636 * is paused until the device leaves the SDEV_BLOCK state. See also
2637 * scsi_internal_device_unblock_nowait().
2639 int scsi_internal_device_block_nowait(struct scsi_device
*sdev
)
2641 struct request_queue
*q
= sdev
->request_queue
;
2644 err
= scsi_device_set_state(sdev
, SDEV_BLOCK
);
2646 err
= scsi_device_set_state(sdev
, SDEV_CREATED_BLOCK
);
2653 * The device has transitioned to SDEV_BLOCK. Stop the
2654 * block layer from calling the midlayer with this device's
2657 blk_mq_quiesce_queue_nowait(q
);
2660 EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait
);
2663 * scsi_internal_device_block - try to transition to the SDEV_BLOCK state
2664 * @sdev: device to block
2666 * Pause SCSI command processing on the specified device and wait until all
2667 * ongoing scsi_request_fn() / scsi_queue_rq() calls have finished. May sleep.
2669 * Returns zero if successful or a negative error code upon failure.
2672 * This routine transitions the device to the SDEV_BLOCK state (which must be
2673 * a legal transition). When the device is in this state, command processing
2674 * is paused until the device leaves the SDEV_BLOCK state. See also
2675 * scsi_internal_device_unblock().
2677 static int scsi_internal_device_block(struct scsi_device
*sdev
)
2679 struct request_queue
*q
= sdev
->request_queue
;
2682 mutex_lock(&sdev
->state_mutex
);
2683 err
= scsi_internal_device_block_nowait(sdev
);
2685 blk_mq_quiesce_queue(q
);
2686 mutex_unlock(&sdev
->state_mutex
);
2691 void scsi_start_queue(struct scsi_device
*sdev
)
2693 struct request_queue
*q
= sdev
->request_queue
;
2695 blk_mq_unquiesce_queue(q
);
2699 * scsi_internal_device_unblock_nowait - resume a device after a block request
2700 * @sdev: device to resume
2701 * @new_state: state to set the device to after unblocking
2703 * Restart the device queue for a previously suspended SCSI device. Does not
2706 * Returns zero if successful or a negative error code upon failure.
2709 * This routine transitions the device to the SDEV_RUNNING state or to one of
2710 * the offline states (which must be a legal transition) allowing the midlayer
2711 * to goose the queue for this device.
2713 int scsi_internal_device_unblock_nowait(struct scsi_device
*sdev
,
2714 enum scsi_device_state new_state
)
2716 switch (new_state
) {
2718 case SDEV_TRANSPORT_OFFLINE
:
2725 * Try to transition the scsi device to SDEV_RUNNING or one of the
2726 * offlined states and goose the device queue if successful.
2728 switch (sdev
->sdev_state
) {
2730 case SDEV_TRANSPORT_OFFLINE
:
2731 sdev
->sdev_state
= new_state
;
2733 case SDEV_CREATED_BLOCK
:
2734 if (new_state
== SDEV_TRANSPORT_OFFLINE
||
2735 new_state
== SDEV_OFFLINE
)
2736 sdev
->sdev_state
= new_state
;
2738 sdev
->sdev_state
= SDEV_CREATED
;
2746 scsi_start_queue(sdev
);
2750 EXPORT_SYMBOL_GPL(scsi_internal_device_unblock_nowait
);
2753 * scsi_internal_device_unblock - resume a device after a block request
2754 * @sdev: device to resume
2755 * @new_state: state to set the device to after unblocking
2757 * Restart the device queue for a previously suspended SCSI device. May sleep.
2759 * Returns zero if successful or a negative error code upon failure.
2762 * This routine transitions the device to the SDEV_RUNNING state or to one of
2763 * the offline states (which must be a legal transition) allowing the midlayer
2764 * to goose the queue for this device.
2766 static int scsi_internal_device_unblock(struct scsi_device
*sdev
,
2767 enum scsi_device_state new_state
)
2771 mutex_lock(&sdev
->state_mutex
);
2772 ret
= scsi_internal_device_unblock_nowait(sdev
, new_state
);
2773 mutex_unlock(&sdev
->state_mutex
);
2779 device_block(struct scsi_device
*sdev
, void *data
)
2783 ret
= scsi_internal_device_block(sdev
);
2785 WARN_ONCE(ret
, "scsi_internal_device_block(%s) failed: ret = %d\n",
2786 dev_name(&sdev
->sdev_gendev
), ret
);
2790 target_block(struct device
*dev
, void *data
)
2792 if (scsi_is_target_device(dev
))
2793 starget_for_each_device(to_scsi_target(dev
), NULL
,
2799 scsi_target_block(struct device
*dev
)
2801 if (scsi_is_target_device(dev
))
2802 starget_for_each_device(to_scsi_target(dev
), NULL
,
2805 device_for_each_child(dev
, NULL
, target_block
);
2807 EXPORT_SYMBOL_GPL(scsi_target_block
);
2810 device_unblock(struct scsi_device
*sdev
, void *data
)
2812 scsi_internal_device_unblock(sdev
, *(enum scsi_device_state
*)data
);
2816 target_unblock(struct device
*dev
, void *data
)
2818 if (scsi_is_target_device(dev
))
2819 starget_for_each_device(to_scsi_target(dev
), data
,
2825 scsi_target_unblock(struct device
*dev
, enum scsi_device_state new_state
)
2827 if (scsi_is_target_device(dev
))
2828 starget_for_each_device(to_scsi_target(dev
), &new_state
,
2831 device_for_each_child(dev
, &new_state
, target_unblock
);
2833 EXPORT_SYMBOL_GPL(scsi_target_unblock
);
2836 scsi_host_block(struct Scsi_Host
*shost
)
2838 struct scsi_device
*sdev
;
2842 * Call scsi_internal_device_block_nowait so we can avoid
2843 * calling synchronize_rcu() for each LUN.
2845 shost_for_each_device(sdev
, shost
) {
2846 mutex_lock(&sdev
->state_mutex
);
2847 ret
= scsi_internal_device_block_nowait(sdev
);
2848 mutex_unlock(&sdev
->state_mutex
);
2850 scsi_device_put(sdev
);
2856 * SCSI never enables blk-mq's BLK_MQ_F_BLOCKING flag so
2857 * calling synchronize_rcu() once is enough.
2859 WARN_ON_ONCE(shost
->tag_set
.flags
& BLK_MQ_F_BLOCKING
);
2866 EXPORT_SYMBOL_GPL(scsi_host_block
);
2869 scsi_host_unblock(struct Scsi_Host
*shost
, int new_state
)
2871 struct scsi_device
*sdev
;
2874 shost_for_each_device(sdev
, shost
) {
2875 ret
= scsi_internal_device_unblock(sdev
, new_state
);
2877 scsi_device_put(sdev
);
2883 EXPORT_SYMBOL_GPL(scsi_host_unblock
);
2886 * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt
2887 * @sgl: scatter-gather list
2888 * @sg_count: number of segments in sg
2889 * @offset: offset in bytes into sg, on return offset into the mapped area
2890 * @len: bytes to map, on return number of bytes mapped
2892 * Returns virtual address of the start of the mapped page
2894 void *scsi_kmap_atomic_sg(struct scatterlist
*sgl
, int sg_count
,
2895 size_t *offset
, size_t *len
)
2898 size_t sg_len
= 0, len_complete
= 0;
2899 struct scatterlist
*sg
;
2902 WARN_ON(!irqs_disabled());
2904 for_each_sg(sgl
, sg
, sg_count
, i
) {
2905 len_complete
= sg_len
; /* Complete sg-entries */
2906 sg_len
+= sg
->length
;
2907 if (sg_len
> *offset
)
2911 if (unlikely(i
== sg_count
)) {
2912 printk(KERN_ERR
"%s: Bytes in sg: %zu, requested offset %zu, "
2914 __func__
, sg_len
, *offset
, sg_count
);
2919 /* Offset starting from the beginning of first page in this sg-entry */
2920 *offset
= *offset
- len_complete
+ sg
->offset
;
2922 /* Assumption: contiguous pages can be accessed as "page + i" */
2923 page
= nth_page(sg_page(sg
), (*offset
>> PAGE_SHIFT
));
2924 *offset
&= ~PAGE_MASK
;
2926 /* Bytes in this sg-entry from *offset to the end of the page */
2927 sg_len
= PAGE_SIZE
- *offset
;
2931 return kmap_atomic(page
);
2933 EXPORT_SYMBOL(scsi_kmap_atomic_sg
);
2936 * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg
2937 * @virt: virtual address to be unmapped
2939 void scsi_kunmap_atomic_sg(void *virt
)
2941 kunmap_atomic(virt
);
2943 EXPORT_SYMBOL(scsi_kunmap_atomic_sg
);
2945 void sdev_disable_disk_events(struct scsi_device
*sdev
)
2947 atomic_inc(&sdev
->disk_events_disable_depth
);
2949 EXPORT_SYMBOL(sdev_disable_disk_events
);
2951 void sdev_enable_disk_events(struct scsi_device
*sdev
)
2953 if (WARN_ON_ONCE(atomic_read(&sdev
->disk_events_disable_depth
) <= 0))
2955 atomic_dec(&sdev
->disk_events_disable_depth
);
2957 EXPORT_SYMBOL(sdev_enable_disk_events
);
2959 static unsigned char designator_prio(const unsigned char *d
)
2962 /* not associated with LUN */
2966 /* invalid length */
2970 * Order of preference for lun descriptor:
2971 * - SCSI name string
2972 * - NAA IEEE Registered Extended
2973 * - EUI-64 based 16-byte
2974 * - EUI-64 based 12-byte
2975 * - NAA IEEE Registered
2976 * - NAA IEEE Extended
2977 * - EUI-64 based 8-byte
2978 * - SCSI name string (truncated)
2980 * as longer descriptors reduce the likelyhood
2981 * of identification clashes.
2984 switch (d
[1] & 0xf) {
2986 /* SCSI name string, variable-length UTF-8 */
2989 switch (d
[4] >> 4) {
2991 /* NAA registered extended */
2994 /* NAA registered */
3000 /* NAA locally assigned */
3009 /* EUI64-based, 16 byte */
3012 /* EUI64-based, 12 byte */
3015 /* EUI64-based, 8 byte */
3032 * scsi_vpd_lun_id - return a unique device identification
3033 * @sdev: SCSI device
3034 * @id: buffer for the identification
3035 * @id_len: length of the buffer
3037 * Copies a unique device identification into @id based
3038 * on the information in the VPD page 0x83 of the device.
3039 * The string will be formatted as a SCSI name string.
3041 * Returns the length of the identification or error on failure.
3042 * If the identifier is longer than the supplied buffer the actual
3043 * identifier length is returned and the buffer is not zero-padded.
3045 int scsi_vpd_lun_id(struct scsi_device
*sdev
, char *id
, size_t id_len
)
3049 const unsigned char *d
, *cur_id_str
;
3050 const struct scsi_vpd
*vpd_pg83
;
3051 int id_size
= -EINVAL
;
3054 vpd_pg83
= rcu_dereference(sdev
->vpd_pg83
);
3060 /* The id string must be at least 20 bytes + terminating NULL byte */
3066 memset(id
, 0, id_len
);
3067 for (d
= vpd_pg83
->data
+ 4;
3068 d
< vpd_pg83
->data
+ vpd_pg83
->len
;
3070 u8 prio
= designator_prio(d
);
3072 if (prio
== 0 || cur_id_prio
> prio
)
3075 switch (d
[1] & 0xf) {
3078 if (cur_id_size
> d
[3])
3082 if (cur_id_size
+ 4 > id_len
)
3083 cur_id_size
= id_len
- 4;
3085 id_size
= snprintf(id
, id_len
, "t10.%*pE",
3086 cur_id_size
, cur_id_str
);
3093 switch (cur_id_size
) {
3095 id_size
= snprintf(id
, id_len
,
3100 id_size
= snprintf(id
, id_len
,
3105 id_size
= snprintf(id
, id_len
,
3118 switch (cur_id_size
) {
3120 id_size
= snprintf(id
, id_len
,
3125 id_size
= snprintf(id
, id_len
,
3134 /* SCSI name string */
3135 if (cur_id_size
> d
[3])
3137 /* Prefer others for truncated descriptor */
3138 if (d
[3] > id_len
) {
3140 if (cur_id_prio
> prio
)
3144 cur_id_size
= id_size
= d
[3];
3146 if (cur_id_size
>= id_len
)
3147 cur_id_size
= id_len
- 1;
3148 memcpy(id
, cur_id_str
, cur_id_size
);
3158 EXPORT_SYMBOL(scsi_vpd_lun_id
);
3161 * scsi_vpd_tpg_id - return a target port group identifier
3162 * @sdev: SCSI device
3164 * Returns the Target Port Group identifier from the information
3165 * froom VPD page 0x83 of the device.
3167 * Returns the identifier or error on failure.
3169 int scsi_vpd_tpg_id(struct scsi_device
*sdev
, int *rel_id
)
3171 const unsigned char *d
;
3172 const struct scsi_vpd
*vpd_pg83
;
3173 int group_id
= -EAGAIN
, rel_port
= -1;
3176 vpd_pg83
= rcu_dereference(sdev
->vpd_pg83
);
3182 d
= vpd_pg83
->data
+ 4;
3183 while (d
< vpd_pg83
->data
+ vpd_pg83
->len
) {
3184 switch (d
[1] & 0xf) {
3186 /* Relative target port */
3187 rel_port
= get_unaligned_be16(&d
[6]);
3190 /* Target port group */
3191 group_id
= get_unaligned_be16(&d
[6]);
3200 if (group_id
>= 0 && rel_id
&& rel_port
!= -1)
3205 EXPORT_SYMBOL(scsi_vpd_tpg_id
);