2 * Copyright (C) 1999 Eric Youngdale
3 * Copyright (C) 2014 Christoph Hellwig
5 * SCSI queueing library.
6 * Initial versions: Eric Youngdale (eric@andante.org).
7 * Based upon conversations with large numbers
8 * of people at Linux Expo.
11 #include <linux/bio.h>
12 #include <linux/bitops.h>
13 #include <linux/blkdev.h>
14 #include <linux/completion.h>
15 #include <linux/kernel.h>
16 #include <linux/export.h>
17 #include <linux/init.h>
18 #include <linux/pci.h>
19 #include <linux/delay.h>
20 #include <linux/hardirq.h>
21 #include <linux/scatterlist.h>
22 #include <linux/blk-mq.h>
23 #include <linux/ratelimit.h>
24 #include <asm/unaligned.h>
26 #include <scsi/scsi.h>
27 #include <scsi/scsi_cmnd.h>
28 #include <scsi/scsi_dbg.h>
29 #include <scsi/scsi_device.h>
30 #include <scsi/scsi_driver.h>
31 #include <scsi/scsi_eh.h>
32 #include <scsi/scsi_host.h>
33 #include <scsi/scsi_transport.h> /* __scsi_init_queue() */
34 #include <scsi/scsi_dh.h>
36 #include <trace/events/scsi.h>
38 #include "scsi_debugfs.h"
39 #include "scsi_priv.h"
40 #include "scsi_logging.h"
42 static struct kmem_cache *scsi_sdb_cache;
43 static struct kmem_cache *scsi_sense_cache;
44 static struct kmem_cache *scsi_sense_isadma_cache;
45 static DEFINE_MUTEX(scsi_sense_cache_mutex);
47 static inline struct kmem_cache *
48 scsi_select_sense_cache(bool unchecked_isa_dma)
50 return unchecked_isa_dma ? scsi_sense_isadma_cache : scsi_sense_cache;
53 static void scsi_free_sense_buffer(bool unchecked_isa_dma,
54 unsigned char *sense_buffer)
56 kmem_cache_free(scsi_select_sense_cache(unchecked_isa_dma),
60 static unsigned char *scsi_alloc_sense_buffer(bool unchecked_isa_dma,
61 gfp_t gfp_mask, int numa_node)
63 return kmem_cache_alloc_node(scsi_select_sense_cache(unchecked_isa_dma),
67 int scsi_init_sense_cache(struct Scsi_Host *shost)
69 struct kmem_cache *cache;
72 cache = scsi_select_sense_cache(shost->unchecked_isa_dma);
76 mutex_lock(&scsi_sense_cache_mutex);
77 if (shost->unchecked_isa_dma) {
78 scsi_sense_isadma_cache =
79 kmem_cache_create("scsi_sense_cache(DMA)",
80 SCSI_SENSE_BUFFERSIZE, 0,
81 SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA, NULL);
82 if (!scsi_sense_isadma_cache)
86 kmem_cache_create("scsi_sense_cache",
87 SCSI_SENSE_BUFFERSIZE, 0, SLAB_HWCACHE_ALIGN, NULL);
88 if (!scsi_sense_cache)
92 mutex_unlock(&scsi_sense_cache_mutex);
97 * When to reinvoke queueing after a resource shortage. It's 3 msecs to
98 * not change behaviour from the previous unplug mechanism, experimentation
99 * may prove this needs changing.
101 #define SCSI_QUEUE_DELAY 3
104 scsi_set_blocked(struct scsi_cmnd *cmd, int reason)
106 struct Scsi_Host *host = cmd->device->host;
107 struct scsi_device *device = cmd->device;
108 struct scsi_target *starget = scsi_target(device);
111 * Set the appropriate busy bit for the device/host.
113 * If the host/device isn't busy, assume that something actually
114 * completed, and that we should be able to queue a command now.
116 * Note that the prior mid-layer assumption that any host could
117 * always queue at least one command is now broken. The mid-layer
118 * will implement a user specifiable stall (see
119 * scsi_host.max_host_blocked and scsi_device.max_device_blocked)
120 * if a command is requeued with no other commands outstanding
121 * either for the device or for the host.
124 case SCSI_MLQUEUE_HOST_BUSY:
125 atomic_set(&host->host_blocked, host->max_host_blocked);
127 case SCSI_MLQUEUE_DEVICE_BUSY:
128 case SCSI_MLQUEUE_EH_RETRY:
129 atomic_set(&device->device_blocked,
130 device->max_device_blocked);
132 case SCSI_MLQUEUE_TARGET_BUSY:
133 atomic_set(&starget->target_blocked,
134 starget->max_target_blocked);
139 static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd)
141 struct scsi_device *sdev = cmd->device;
143 blk_mq_requeue_request(cmd->request, true);
144 put_device(&sdev->sdev_gendev);
148 * __scsi_queue_insert - private queue insertion
149 * @cmd: The SCSI command being requeued
150 * @reason: The reason for the requeue
151 * @unbusy: Whether the queue should be unbusied
153 * This is a private queue insertion. The public interface
154 * scsi_queue_insert() always assumes the queue should be unbusied
155 * because it's always called before the completion. This function is
156 * for a requeue after completion, which should only occur in this
159 static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy)
161 struct scsi_device *device = cmd->device;
162 struct request_queue *q = device->request_queue;
165 SCSI_LOG_MLQUEUE(1, scmd_printk(KERN_INFO, cmd,
166 "Inserting command %p into mlqueue\n", cmd));
168 scsi_set_blocked(cmd, reason);
171 * Decrement the counters, since these commands are no longer
172 * active on the host/device.
175 scsi_device_unbusy(device);
178 * Requeue this command. It will go before all other commands
179 * that are already in the queue. Schedule requeue work under
180 * lock such that the kblockd_schedule_work() call happens
181 * before blk_cleanup_queue() finishes.
185 scsi_mq_requeue_cmd(cmd);
188 spin_lock_irqsave(q->queue_lock, flags);
189 blk_requeue_request(q, cmd->request);
190 kblockd_schedule_work(&device->requeue_work);
191 spin_unlock_irqrestore(q->queue_lock, flags);
195 * Function: scsi_queue_insert()
197 * Purpose: Insert a command in the midlevel queue.
199 * Arguments: cmd - command that we are adding to queue.
200 * reason - why we are inserting command to queue.
202 * Lock status: Assumed that lock is not held upon entry.
206 * Notes: We do this for one of two cases. Either the host is busy
207 * and it cannot accept any more commands for the time being,
208 * or the device returned QUEUE_FULL and can accept no more
210 * Notes: This could be called either from an interrupt context or a
211 * normal process context.
213 void scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
215 __scsi_queue_insert(cmd, reason, 1);
220 * scsi_execute - insert request and wait for the result
223 * @data_direction: data direction
224 * @buffer: data buffer
225 * @bufflen: len of buffer
226 * @sense: optional sense buffer
227 * @sshdr: optional decoded sense header
228 * @timeout: request timeout in seconds
229 * @retries: number of times to retry request
230 * @flags: flags for ->cmd_flags
231 * @rq_flags: flags for ->rq_flags
232 * @resid: optional residual length
234 * Returns the scsi_cmnd result field if a command was executed, or a negative
235 * Linux error code if we didn't get that far.
237 int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
238 int data_direction, void *buffer, unsigned bufflen,
239 unsigned char *sense, struct scsi_sense_hdr *sshdr,
240 int timeout, int retries, u64 flags, req_flags_t rq_flags,
244 struct scsi_request *rq;
245 int ret = DRIVER_ERROR << 24;
247 req = blk_get_request(sdev->request_queue,
248 data_direction == DMA_TO_DEVICE ?
249 REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, __GFP_RECLAIM);
255 if (bufflen && blk_rq_map_kern(sdev->request_queue, req,
256 buffer, bufflen, __GFP_RECLAIM))
259 rq->cmd_len = COMMAND_SIZE(cmd[0]);
260 memcpy(rq->cmd, cmd, rq->cmd_len);
261 rq->retries = retries;
262 req->timeout = timeout;
263 req->cmd_flags |= flags;
264 req->rq_flags |= rq_flags | RQF_QUIET | RQF_PREEMPT;
267 * head injection *required* here otherwise quiesce won't work
269 blk_execute_rq(req->q, NULL, req, 1);
272 * Some devices (USB mass-storage in particular) may transfer
273 * garbage data together with a residue indicating that the data
274 * is invalid. Prevent the garbage from being misinterpreted
275 * and prevent security leaks by zeroing out the excess data.
277 if (unlikely(rq->resid_len > 0 && rq->resid_len <= bufflen))
278 memset(buffer + (bufflen - rq->resid_len), 0, rq->resid_len);
281 *resid = rq->resid_len;
282 if (sense && rq->sense_len)
283 memcpy(sense, rq->sense, SCSI_SENSE_BUFFERSIZE);
285 scsi_normalize_sense(rq->sense, rq->sense_len, sshdr);
288 blk_put_request(req);
292 EXPORT_SYMBOL(scsi_execute);
295 * Function: scsi_init_cmd_errh()
297 * Purpose: Initialize cmd fields related to error handling.
299 * Arguments: cmd - command that is ready to be queued.
301 * Notes: This function has the job of initializing a number of
302 * fields related to error handling. Typically this will
303 * be called once for each command, as required.
305 static void scsi_init_cmd_errh(struct scsi_cmnd *cmd)
307 cmd->serial_number = 0;
308 scsi_set_resid(cmd, 0);
309 memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
310 if (cmd->cmd_len == 0)
311 cmd->cmd_len = scsi_command_size(cmd->cmnd);
314 void scsi_device_unbusy(struct scsi_device *sdev)
316 struct Scsi_Host *shost = sdev->host;
317 struct scsi_target *starget = scsi_target(sdev);
320 atomic_dec(&shost->host_busy);
321 if (starget->can_queue > 0)
322 atomic_dec(&starget->target_busy);
324 if (unlikely(scsi_host_in_recovery(shost) &&
325 (shost->host_failed || shost->host_eh_scheduled))) {
326 spin_lock_irqsave(shost->host_lock, flags);
327 scsi_eh_wakeup(shost);
328 spin_unlock_irqrestore(shost->host_lock, flags);
331 atomic_dec(&sdev->device_busy);
334 static void scsi_kick_queue(struct request_queue *q)
337 blk_mq_start_hw_queues(q);
343 * Called for single_lun devices on IO completion. Clear starget_sdev_user,
344 * and call blk_run_queue for all the scsi_devices on the target -
345 * including current_sdev first.
347 * Called with *no* scsi locks held.
349 static void scsi_single_lun_run(struct scsi_device *current_sdev)
351 struct Scsi_Host *shost = current_sdev->host;
352 struct scsi_device *sdev, *tmp;
353 struct scsi_target *starget = scsi_target(current_sdev);
356 spin_lock_irqsave(shost->host_lock, flags);
357 starget->starget_sdev_user = NULL;
358 spin_unlock_irqrestore(shost->host_lock, flags);
361 * Call blk_run_queue for all LUNs on the target, starting with
362 * current_sdev. We race with others (to set starget_sdev_user),
363 * but in most cases, we will be first. Ideally, each LU on the
364 * target would get some limited time or requests on the target.
366 scsi_kick_queue(current_sdev->request_queue);
368 spin_lock_irqsave(shost->host_lock, flags);
369 if (starget->starget_sdev_user)
371 list_for_each_entry_safe(sdev, tmp, &starget->devices,
372 same_target_siblings) {
373 if (sdev == current_sdev)
375 if (scsi_device_get(sdev))
378 spin_unlock_irqrestore(shost->host_lock, flags);
379 scsi_kick_queue(sdev->request_queue);
380 spin_lock_irqsave(shost->host_lock, flags);
382 scsi_device_put(sdev);
385 spin_unlock_irqrestore(shost->host_lock, flags);
388 static inline bool scsi_device_is_busy(struct scsi_device *sdev)
390 if (atomic_read(&sdev->device_busy) >= sdev->queue_depth)
392 if (atomic_read(&sdev->device_blocked) > 0)
397 static inline bool scsi_target_is_busy(struct scsi_target *starget)
399 if (starget->can_queue > 0) {
400 if (atomic_read(&starget->target_busy) >= starget->can_queue)
402 if (atomic_read(&starget->target_blocked) > 0)
408 static inline bool scsi_host_is_busy(struct Scsi_Host *shost)
410 if (shost->can_queue > 0 &&
411 atomic_read(&shost->host_busy) >= shost->can_queue)
413 if (atomic_read(&shost->host_blocked) > 0)
415 if (shost->host_self_blocked)
420 static void scsi_starved_list_run(struct Scsi_Host *shost)
422 LIST_HEAD(starved_list);
423 struct scsi_device *sdev;
426 spin_lock_irqsave(shost->host_lock, flags);
427 list_splice_init(&shost->starved_list, &starved_list);
429 while (!list_empty(&starved_list)) {
430 struct request_queue *slq;
433 * As long as shost is accepting commands and we have
434 * starved queues, call blk_run_queue. scsi_request_fn
435 * drops the queue_lock and can add us back to the
438 * host_lock protects the starved_list and starved_entry.
439 * scsi_request_fn must get the host_lock before checking
440 * or modifying starved_list or starved_entry.
442 if (scsi_host_is_busy(shost))
445 sdev = list_entry(starved_list.next,
446 struct scsi_device, starved_entry);
447 list_del_init(&sdev->starved_entry);
448 if (scsi_target_is_busy(scsi_target(sdev))) {
449 list_move_tail(&sdev->starved_entry,
450 &shost->starved_list);
455 * Once we drop the host lock, a racing scsi_remove_device()
456 * call may remove the sdev from the starved list and destroy
457 * it and the queue. Mitigate by taking a reference to the
458 * queue and never touching the sdev again after we drop the
459 * host lock. Note: if __scsi_remove_device() invokes
460 * blk_cleanup_queue() before the queue is run from this
461 * function then blk_run_queue() will return immediately since
462 * blk_cleanup_queue() marks the queue with QUEUE_FLAG_DYING.
464 slq = sdev->request_queue;
465 if (!blk_get_queue(slq))
467 spin_unlock_irqrestore(shost->host_lock, flags);
469 scsi_kick_queue(slq);
472 spin_lock_irqsave(shost->host_lock, flags);
474 /* put any unprocessed entries back */
475 list_splice(&starved_list, &shost->starved_list);
476 spin_unlock_irqrestore(shost->host_lock, flags);
480 * Function: scsi_run_queue()
482 * Purpose: Select a proper request queue to serve next
484 * Arguments: q - last request's queue
488 * Notes: The previous command was completely finished, start
489 * a new one if possible.
491 static void scsi_run_queue(struct request_queue *q)
493 struct scsi_device *sdev = q->queuedata;
495 if (scsi_target(sdev)->single_lun)
496 scsi_single_lun_run(sdev);
497 if (!list_empty(&sdev->host->starved_list))
498 scsi_starved_list_run(sdev->host);
501 blk_mq_run_hw_queues(q, false);
506 void scsi_requeue_run_queue(struct work_struct *work)
508 struct scsi_device *sdev;
509 struct request_queue *q;
511 sdev = container_of(work, struct scsi_device, requeue_work);
512 q = sdev->request_queue;
517 * Function: scsi_requeue_command()
519 * Purpose: Handle post-processing of completed commands.
521 * Arguments: q - queue to operate on
522 * cmd - command that may need to be requeued.
526 * Notes: After command completion, there may be blocks left
527 * over which weren't finished by the previous command
528 * this can be for a number of reasons - the main one is
529 * I/O errors in the middle of the request, in which case
530 * we need to request the blocks that come after the bad
532 * Notes: Upon return, cmd is a stale pointer.
534 static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd)
536 struct scsi_device *sdev = cmd->device;
537 struct request *req = cmd->request;
540 spin_lock_irqsave(q->queue_lock, flags);
541 blk_unprep_request(req);
543 scsi_put_command(cmd);
544 blk_requeue_request(q, req);
545 spin_unlock_irqrestore(q->queue_lock, flags);
549 put_device(&sdev->sdev_gendev);
552 void scsi_run_host_queues(struct Scsi_Host *shost)
554 struct scsi_device *sdev;
556 shost_for_each_device(sdev, shost)
557 scsi_run_queue(sdev->request_queue);
560 static void scsi_uninit_cmd(struct scsi_cmnd *cmd)
562 if (!blk_rq_is_passthrough(cmd->request)) {
563 struct scsi_driver *drv = scsi_cmd_to_driver(cmd);
565 if (drv->uninit_command)
566 drv->uninit_command(cmd);
570 static void scsi_mq_free_sgtables(struct scsi_cmnd *cmd)
572 struct scsi_data_buffer *sdb;
574 if (cmd->sdb.table.nents)
575 sg_free_table_chained(&cmd->sdb.table, true);
576 if (cmd->request->next_rq) {
577 sdb = cmd->request->next_rq->special;
579 sg_free_table_chained(&sdb->table, true);
581 if (scsi_prot_sg_count(cmd))
582 sg_free_table_chained(&cmd->prot_sdb->table, true);
585 static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd)
587 scsi_mq_free_sgtables(cmd);
588 scsi_uninit_cmd(cmd);
589 scsi_del_cmd_from_list(cmd);
593 * Function: scsi_release_buffers()
595 * Purpose: Free resources allocate for a scsi_command.
597 * Arguments: cmd - command that we are bailing.
599 * Lock status: Assumed that no lock is held upon entry.
603 * Notes: In the event that an upper level driver rejects a
604 * command, we must release resources allocated during
605 * the __init_io() function. Primarily this would involve
606 * the scatter-gather table.
608 static void scsi_release_buffers(struct scsi_cmnd *cmd)
610 if (cmd->sdb.table.nents)
611 sg_free_table_chained(&cmd->sdb.table, false);
613 memset(&cmd->sdb, 0, sizeof(cmd->sdb));
615 if (scsi_prot_sg_count(cmd))
616 sg_free_table_chained(&cmd->prot_sdb->table, false);
619 static void scsi_release_bidi_buffers(struct scsi_cmnd *cmd)
621 struct scsi_data_buffer *bidi_sdb = cmd->request->next_rq->special;
623 sg_free_table_chained(&bidi_sdb->table, false);
624 kmem_cache_free(scsi_sdb_cache, bidi_sdb);
625 cmd->request->next_rq->special = NULL;
628 static bool scsi_end_request(struct request *req, int error,
629 unsigned int bytes, unsigned int bidi_bytes)
631 struct scsi_cmnd *cmd = req->special;
632 struct scsi_device *sdev = cmd->device;
633 struct request_queue *q = sdev->request_queue;
635 if (blk_update_request(req, error, bytes))
638 /* Bidi request must be completed as a whole */
639 if (unlikely(bidi_bytes) &&
640 blk_update_request(req->next_rq, error, bidi_bytes))
643 if (blk_queue_add_random(q))
644 add_disk_randomness(req->rq_disk);
648 * In the MQ case the command gets freed by __blk_mq_end_request,
649 * so we have to do all cleanup that depends on it earlier.
651 * We also can't kick the queues from irq context, so we
652 * will have to defer it to a workqueue.
654 scsi_mq_uninit_cmd(cmd);
656 __blk_mq_end_request(req, error);
658 if (scsi_target(sdev)->single_lun ||
659 !list_empty(&sdev->host->starved_list))
660 kblockd_schedule_work(&sdev->requeue_work);
662 blk_mq_run_hw_queues(q, true);
667 scsi_release_bidi_buffers(cmd);
668 scsi_release_buffers(cmd);
669 scsi_put_command(cmd);
671 spin_lock_irqsave(q->queue_lock, flags);
672 blk_finish_request(req, error);
673 spin_unlock_irqrestore(q->queue_lock, flags);
678 put_device(&sdev->sdev_gendev);
683 * __scsi_error_from_host_byte - translate SCSI error code into errno
684 * @cmd: SCSI command (unused)
685 * @result: scsi error code
687 * Translate SCSI error code into standard UNIX errno.
689 * -ENOLINK temporary transport failure
690 * -EREMOTEIO permanent target failure, do not retry
691 * -EBADE permanent nexus failure, retry on other path
692 * -ENOSPC No write space available
693 * -ENODATA Medium error
694 * -EIO unspecified I/O error
696 static int __scsi_error_from_host_byte(struct scsi_cmnd *cmd, int result)
700 switch(host_byte(result)) {
701 case DID_TRANSPORT_FAILFAST:
704 case DID_TARGET_FAILURE:
705 set_host_byte(cmd, DID_OK);
708 case DID_NEXUS_FAILURE:
709 set_host_byte(cmd, DID_OK);
712 case DID_ALLOC_FAILURE:
713 set_host_byte(cmd, DID_OK);
716 case DID_MEDIUM_ERROR:
717 set_host_byte(cmd, DID_OK);
729 * Function: scsi_io_completion()
731 * Purpose: Completion processing for block device I/O requests.
733 * Arguments: cmd - command that is finished.
735 * Lock status: Assumed that no lock is held upon entry.
739 * Notes: We will finish off the specified number of sectors. If we
740 * are done, the command block will be released and the queue
741 * function will be goosed. If we are not done then we have to
742 * figure out what to do next:
744 * a) We can call scsi_requeue_command(). The request
745 * will be unprepared and put back on the queue. Then
746 * a new command will be created for it. This should
747 * be used if we made forward progress, or if we want
748 * to switch from READ(10) to READ(6) for example.
750 * b) We can call __scsi_queue_insert(). The request will
751 * be put back on the queue and retried using the same
752 * command as before, possibly after a delay.
754 * c) We can call scsi_end_request() with -EIO to fail
755 * the remainder of the request.
757 void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
759 int result = cmd->result;
760 struct request_queue *q = cmd->device->request_queue;
761 struct request *req = cmd->request;
763 struct scsi_sense_hdr sshdr;
764 bool sense_valid = false;
765 int sense_deferred = 0, level = 0;
766 enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY,
767 ACTION_DELAYED_RETRY} action;
768 unsigned long wait_for = (cmd->allowed + 1) * req->timeout;
771 sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
773 sense_deferred = scsi_sense_is_deferred(&sshdr);
776 if (blk_rq_is_passthrough(req)) {
780 * SG_IO wants current and deferred errors
782 scsi_req(req)->sense_len =
783 min(8 + cmd->sense_buffer[7],
784 SCSI_SENSE_BUFFERSIZE);
787 error = __scsi_error_from_host_byte(cmd, result);
790 * __scsi_error_from_host_byte may have reset the host_byte
792 scsi_req(req)->result = cmd->result;
793 scsi_req(req)->resid_len = scsi_get_resid(cmd);
795 if (scsi_bidi_cmnd(cmd)) {
797 * Bidi commands Must be complete as a whole,
798 * both sides at once.
800 scsi_req(req->next_rq)->resid_len = scsi_in(cmd)->resid;
801 if (scsi_end_request(req, 0, blk_rq_bytes(req),
802 blk_rq_bytes(req->next_rq)))
806 } else if (blk_rq_bytes(req) == 0 && result && !sense_deferred) {
808 * Flush commands do not transfers any data, and thus cannot use
809 * good_bytes != blk_rq_bytes(req) as the signal for an error.
810 * This sets the error explicitly for the problem case.
812 error = __scsi_error_from_host_byte(cmd, result);
815 /* no bidi support for !blk_rq_is_passthrough yet */
816 BUG_ON(blk_bidi_rq(req));
819 * Next deal with any sectors which we were able to correctly
822 SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, cmd,
823 "%u sectors total, %d bytes done.\n",
824 blk_rq_sectors(req), good_bytes));
827 * Recovered errors need reporting, but they're always treated as
828 * success, so fiddle the result code here. For passthrough requests
829 * we already took a copy of the original into sreq->result which
830 * is what gets returned to the user
832 if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) {
833 /* if ATA PASS-THROUGH INFORMATION AVAILABLE skip
834 * print since caller wants ATA registers. Only occurs on
835 * SCSI ATA PASS_THROUGH commands when CK_COND=1
837 if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d))
839 else if (!(req->rq_flags & RQF_QUIET))
840 scsi_print_sense(cmd);
842 /* for passthrough error may be set */
847 * special case: failed zero length commands always need to
848 * drop down into the retry code. Otherwise, if we finished
849 * all bytes in the request we are done now.
851 if (!(blk_rq_bytes(req) == 0 && error) &&
852 !scsi_end_request(req, error, good_bytes, 0))
856 * Kill remainder if no retrys.
858 if (error && scsi_noretry_cmd(cmd)) {
859 if (scsi_end_request(req, error, blk_rq_bytes(req), 0))
865 * If there had been no error, but we have leftover bytes in the
866 * requeues just queue the command up again.
871 error = __scsi_error_from_host_byte(cmd, result);
873 if (host_byte(result) == DID_RESET) {
874 /* Third party bus reset or reset for error recovery
875 * reasons. Just retry the command and see what
878 action = ACTION_RETRY;
879 } else if (sense_valid && !sense_deferred) {
880 switch (sshdr.sense_key) {
882 if (cmd->device->removable) {
883 /* Detected disc change. Set a bit
884 * and quietly refuse further access.
886 cmd->device->changed = 1;
887 action = ACTION_FAIL;
889 /* Must have been a power glitch, or a
890 * bus reset. Could not have been a
891 * media change, so we just retry the
892 * command and see what happens.
894 action = ACTION_RETRY;
897 case ILLEGAL_REQUEST:
898 /* If we had an ILLEGAL REQUEST returned, then
899 * we may have performed an unsupported
900 * command. The only thing this should be
901 * would be a ten byte read where only a six
902 * byte read was supported. Also, on a system
903 * where READ CAPACITY failed, we may have
904 * read past the end of the disk.
906 if ((cmd->device->use_10_for_rw &&
907 sshdr.asc == 0x20 && sshdr.ascq == 0x00) &&
908 (cmd->cmnd[0] == READ_10 ||
909 cmd->cmnd[0] == WRITE_10)) {
910 /* This will issue a new 6-byte command. */
911 cmd->device->use_10_for_rw = 0;
912 action = ACTION_REPREP;
913 } else if (sshdr.asc == 0x10) /* DIX */ {
914 action = ACTION_FAIL;
916 /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
917 } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) {
918 action = ACTION_FAIL;
921 action = ACTION_FAIL;
923 case ABORTED_COMMAND:
924 action = ACTION_FAIL;
925 if (sshdr.asc == 0x10) /* DIF */
929 /* If the device is in the process of becoming
930 * ready, or has a temporary blockage, retry.
932 if (sshdr.asc == 0x04) {
933 switch (sshdr.ascq) {
934 case 0x01: /* becoming ready */
935 case 0x04: /* format in progress */
936 case 0x05: /* rebuild in progress */
937 case 0x06: /* recalculation in progress */
938 case 0x07: /* operation in progress */
939 case 0x08: /* Long write in progress */
940 case 0x09: /* self test in progress */
941 case 0x14: /* space allocation in progress */
942 action = ACTION_DELAYED_RETRY;
945 action = ACTION_FAIL;
949 action = ACTION_FAIL;
951 case VOLUME_OVERFLOW:
952 /* See SSC3rXX or current. */
953 action = ACTION_FAIL;
956 action = ACTION_FAIL;
960 action = ACTION_FAIL;
962 if (action != ACTION_FAIL &&
963 time_before(cmd->jiffies_at_alloc + wait_for, jiffies))
964 action = ACTION_FAIL;
968 /* Give up and fail the remainder of the request */
969 if (!(req->rq_flags & RQF_QUIET)) {
970 static DEFINE_RATELIMIT_STATE(_rs,
971 DEFAULT_RATELIMIT_INTERVAL,
972 DEFAULT_RATELIMIT_BURST);
974 if (unlikely(scsi_logging_level))
975 level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
976 SCSI_LOG_MLCOMPLETE_BITS);
979 * if logging is enabled the failure will be printed
980 * in scsi_log_completion(), so avoid duplicate messages
982 if (!level && __ratelimit(&_rs)) {
983 scsi_print_result(cmd, NULL, FAILED);
984 if (driver_byte(result) & DRIVER_SENSE)
985 scsi_print_sense(cmd);
986 scsi_print_command(cmd);
989 if (!scsi_end_request(req, error, blk_rq_err_bytes(req), 0))
994 /* Unprep the request and put it back at the head of the queue.
995 * A new command will be prepared and issued.
998 cmd->request->rq_flags &= ~RQF_DONTPREP;
999 scsi_mq_uninit_cmd(cmd);
1000 scsi_mq_requeue_cmd(cmd);
1002 scsi_release_buffers(cmd);
1003 scsi_requeue_command(q, cmd);
1007 /* Retry the same command immediately */
1008 __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0);
1010 case ACTION_DELAYED_RETRY:
1011 /* Retry the same command after a delay */
1012 __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0);
1017 static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb)
1022 * If sg table allocation fails, requeue request later.
1024 if (unlikely(sg_alloc_table_chained(&sdb->table,
1025 blk_rq_nr_phys_segments(req), sdb->table.sgl)))
1026 return BLKPREP_DEFER;
1029 * Next, walk the list, and fill in the addresses and sizes of
1032 count = blk_rq_map_sg(req->q, req, sdb->table.sgl);
1033 BUG_ON(count > sdb->table.nents);
1034 sdb->table.nents = count;
1035 sdb->length = blk_rq_payload_bytes(req);
1040 * Function: scsi_init_io()
1042 * Purpose: SCSI I/O initialize function.
1044 * Arguments: cmd - Command descriptor we wish to initialize
1046 * Returns: 0 on success
1047 * BLKPREP_DEFER if the failure is retryable
1048 * BLKPREP_KILL if the failure is fatal
1050 int scsi_init_io(struct scsi_cmnd *cmd)
1052 struct scsi_device *sdev = cmd->device;
1053 struct request *rq = cmd->request;
1054 bool is_mq = (rq->mq_ctx != NULL);
1055 int error = BLKPREP_KILL;
1057 if (WARN_ON_ONCE(!blk_rq_nr_phys_segments(rq)))
1060 error = scsi_init_sgtable(rq, &cmd->sdb);
1064 if (blk_bidi_rq(rq)) {
1065 if (!rq->q->mq_ops) {
1066 struct scsi_data_buffer *bidi_sdb =
1067 kmem_cache_zalloc(scsi_sdb_cache, GFP_ATOMIC);
1069 error = BLKPREP_DEFER;
1073 rq->next_rq->special = bidi_sdb;
1076 error = scsi_init_sgtable(rq->next_rq, rq->next_rq->special);
1081 if (blk_integrity_rq(rq)) {
1082 struct scsi_data_buffer *prot_sdb = cmd->prot_sdb;
1085 if (prot_sdb == NULL) {
1087 * This can happen if someone (e.g. multipath)
1088 * queues a command to a device on an adapter
1089 * that does not support DIX.
1092 error = BLKPREP_KILL;
1096 ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio);
1098 if (sg_alloc_table_chained(&prot_sdb->table, ivecs,
1099 prot_sdb->table.sgl)) {
1100 error = BLKPREP_DEFER;
1104 count = blk_rq_map_integrity_sg(rq->q, rq->bio,
1105 prot_sdb->table.sgl);
1106 BUG_ON(unlikely(count > ivecs));
1107 BUG_ON(unlikely(count > queue_max_integrity_segments(rq->q)));
1109 cmd->prot_sdb = prot_sdb;
1110 cmd->prot_sdb->table.nents = count;
1116 scsi_mq_free_sgtables(cmd);
1118 scsi_release_buffers(cmd);
1119 cmd->request->special = NULL;
1120 scsi_put_command(cmd);
1121 put_device(&sdev->sdev_gendev);
1125 EXPORT_SYMBOL(scsi_init_io);
1127 /* Add a command to the list used by the aacraid and dpt_i2o drivers */
1128 void scsi_add_cmd_to_list(struct scsi_cmnd *cmd)
1130 struct scsi_device *sdev = cmd->device;
1131 struct Scsi_Host *shost = sdev->host;
1132 unsigned long flags;
1134 if (shost->use_cmd_list) {
1135 spin_lock_irqsave(&sdev->list_lock, flags);
1136 list_add_tail(&cmd->list, &sdev->cmd_list);
1137 spin_unlock_irqrestore(&sdev->list_lock, flags);
1141 /* Remove a command from the list used by the aacraid and dpt_i2o drivers */
1142 void scsi_del_cmd_from_list(struct scsi_cmnd *cmd)
1144 struct scsi_device *sdev = cmd->device;
1145 struct Scsi_Host *shost = sdev->host;
1146 unsigned long flags;
1148 if (shost->use_cmd_list) {
1149 spin_lock_irqsave(&sdev->list_lock, flags);
1150 BUG_ON(list_empty(&cmd->list));
1151 list_del_init(&cmd->list);
1152 spin_unlock_irqrestore(&sdev->list_lock, flags);
1156 void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
1158 void *buf = cmd->sense_buffer;
1159 void *prot = cmd->prot_sdb;
1160 unsigned int unchecked_isa_dma = cmd->flags & SCMD_UNCHECKED_ISA_DMA;
1162 /* zero out the cmd, except for the embedded scsi_request */
1163 memset((char *)cmd + sizeof(cmd->req), 0,
1164 sizeof(*cmd) - sizeof(cmd->req) + dev->host->hostt->cmd_size);
1167 cmd->sense_buffer = buf;
1168 cmd->prot_sdb = prot;
1169 cmd->flags = unchecked_isa_dma;
1170 INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
1171 cmd->jiffies_at_alloc = jiffies;
1173 scsi_add_cmd_to_list(cmd);
1176 static int scsi_setup_scsi_cmnd(struct scsi_device *sdev, struct request *req)
1178 struct scsi_cmnd *cmd = req->special;
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 int ret = scsi_init_io(cmd);
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 cmd->cmnd = scsi_req(req)->cmd;
1198 cmd->transfersize = blk_rq_bytes(req);
1199 cmd->allowed = scsi_req(req)->retries;
1204 * Setup a normal block command. These are simple request from filesystems
1205 * that still need to be translated to SCSI CDBs from the ULD.
1207 static int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
1209 struct scsi_cmnd *cmd = req->special;
1211 if (unlikely(sdev->handler && sdev->handler->prep_fn)) {
1212 int ret = sdev->handler->prep_fn(sdev, req);
1213 if (ret != BLKPREP_OK)
1217 cmd->cmnd = scsi_req(req)->cmd = scsi_req(req)->__cmd;
1218 memset(cmd->cmnd, 0, BLK_MAX_CDB);
1219 return scsi_cmd_to_driver(cmd)->init_command(cmd);
1222 static int scsi_setup_cmnd(struct scsi_device *sdev, struct request *req)
1224 struct scsi_cmnd *cmd = req->special;
1226 if (!blk_rq_bytes(req))
1227 cmd->sc_data_direction = DMA_NONE;
1228 else if (rq_data_dir(req) == WRITE)
1229 cmd->sc_data_direction = DMA_TO_DEVICE;
1231 cmd->sc_data_direction = DMA_FROM_DEVICE;
1233 if (blk_rq_is_scsi(req))
1234 return scsi_setup_scsi_cmnd(sdev, req);
1236 return scsi_setup_fs_cmnd(sdev, req);
1240 scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
1242 int ret = BLKPREP_OK;
1245 * If the device is not in running state we will reject some
1248 if (unlikely(sdev->sdev_state != SDEV_RUNNING)) {
1249 switch (sdev->sdev_state) {
1251 case SDEV_TRANSPORT_OFFLINE:
1253 * If the device is offline we refuse to process any
1254 * commands. The device must be brought online
1255 * before trying any recovery commands.
1257 sdev_printk(KERN_ERR, sdev,
1258 "rejecting I/O to offline device\n");
1263 * If the device is fully deleted, we refuse to
1264 * process any commands as well.
1266 sdev_printk(KERN_ERR, sdev,
1267 "rejecting I/O to dead device\n");
1271 case SDEV_CREATED_BLOCK:
1272 ret = BLKPREP_DEFER;
1276 * If the devices is blocked we defer normal commands.
1278 if (!(req->rq_flags & RQF_PREEMPT))
1279 ret = BLKPREP_DEFER;
1283 * For any other not fully online state we only allow
1284 * special commands. In particular any user initiated
1285 * command is not allowed.
1287 if (!(req->rq_flags & RQF_PREEMPT))
1296 scsi_prep_return(struct request_queue *q, struct request *req, int ret)
1298 struct scsi_device *sdev = q->queuedata;
1302 case BLKPREP_INVALID:
1303 scsi_req(req)->result = DID_NO_CONNECT << 16;
1304 /* release the command and kill it */
1306 struct scsi_cmnd *cmd = req->special;
1307 scsi_release_buffers(cmd);
1308 scsi_put_command(cmd);
1309 put_device(&sdev->sdev_gendev);
1310 req->special = NULL;
1315 * If we defer, the blk_peek_request() returns NULL, but the
1316 * queue must be restarted, so we schedule a callback to happen
1319 if (atomic_read(&sdev->device_busy) == 0)
1320 blk_delay_queue(q, SCSI_QUEUE_DELAY);
1323 req->rq_flags |= RQF_DONTPREP;
1329 static int scsi_prep_fn(struct request_queue *q, struct request *req)
1331 struct scsi_device *sdev = q->queuedata;
1332 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
1335 ret = scsi_prep_state_check(sdev, req);
1336 if (ret != BLKPREP_OK)
1339 if (!req->special) {
1340 /* Bail if we can't get a reference to the device */
1341 if (unlikely(!get_device(&sdev->sdev_gendev))) {
1342 ret = BLKPREP_DEFER;
1346 scsi_init_command(sdev, cmd);
1350 cmd->tag = req->tag;
1352 cmd->prot_op = SCSI_PROT_NORMAL;
1354 ret = scsi_setup_cmnd(sdev, req);
1356 return scsi_prep_return(q, req, ret);
1359 static void scsi_unprep_fn(struct request_queue *q, struct request *req)
1361 scsi_uninit_cmd(req->special);
1365 * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else
1368 * Called with the queue_lock held.
1370 static inline int scsi_dev_queue_ready(struct request_queue *q,
1371 struct scsi_device *sdev)
1375 busy = atomic_inc_return(&sdev->device_busy) - 1;
1376 if (atomic_read(&sdev->device_blocked)) {
1381 * unblock after device_blocked iterates to zero
1383 if (atomic_dec_return(&sdev->device_blocked) > 0) {
1385 * For the MQ case we take care of this in the caller.
1388 blk_delay_queue(q, SCSI_QUEUE_DELAY);
1391 SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev,
1392 "unblocking device at zero depth\n"));
1395 if (busy >= sdev->queue_depth)
1400 atomic_dec(&sdev->device_busy);
1405 * scsi_target_queue_ready: checks if there we can send commands to target
1406 * @sdev: scsi device on starget to check.
1408 static inline int scsi_target_queue_ready(struct Scsi_Host *shost,
1409 struct scsi_device *sdev)
1411 struct scsi_target *starget = scsi_target(sdev);
1414 if (starget->single_lun) {
1415 spin_lock_irq(shost->host_lock);
1416 if (starget->starget_sdev_user &&
1417 starget->starget_sdev_user != sdev) {
1418 spin_unlock_irq(shost->host_lock);
1421 starget->starget_sdev_user = sdev;
1422 spin_unlock_irq(shost->host_lock);
1425 if (starget->can_queue <= 0)
1428 busy = atomic_inc_return(&starget->target_busy) - 1;
1429 if (atomic_read(&starget->target_blocked) > 0) {
1434 * unblock after target_blocked iterates to zero
1436 if (atomic_dec_return(&starget->target_blocked) > 0)
1439 SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget,
1440 "unblocking target at zero depth\n"));
1443 if (busy >= starget->can_queue)
1449 spin_lock_irq(shost->host_lock);
1450 list_move_tail(&sdev->starved_entry, &shost->starved_list);
1451 spin_unlock_irq(shost->host_lock);
1453 if (starget->can_queue > 0)
1454 atomic_dec(&starget->target_busy);
1459 * scsi_host_queue_ready: if we can send requests to shost, return 1 else
1460 * return 0. We must end up running the queue again whenever 0 is
1461 * returned, else IO can hang.
1463 static inline int scsi_host_queue_ready(struct request_queue *q,
1464 struct Scsi_Host *shost,
1465 struct scsi_device *sdev)
1469 if (scsi_host_in_recovery(shost))
1472 busy = atomic_inc_return(&shost->host_busy) - 1;
1473 if (atomic_read(&shost->host_blocked) > 0) {
1478 * unblock after host_blocked iterates to zero
1480 if (atomic_dec_return(&shost->host_blocked) > 0)
1484 shost_printk(KERN_INFO, shost,
1485 "unblocking host at zero depth\n"));
1488 if (shost->can_queue > 0 && busy >= shost->can_queue)
1490 if (shost->host_self_blocked)
1493 /* We're OK to process the command, so we can't be starved */
1494 if (!list_empty(&sdev->starved_entry)) {
1495 spin_lock_irq(shost->host_lock);
1496 if (!list_empty(&sdev->starved_entry))
1497 list_del_init(&sdev->starved_entry);
1498 spin_unlock_irq(shost->host_lock);
1504 spin_lock_irq(shost->host_lock);
1505 if (list_empty(&sdev->starved_entry))
1506 list_add_tail(&sdev->starved_entry, &shost->starved_list);
1507 spin_unlock_irq(shost->host_lock);
1509 atomic_dec(&shost->host_busy);
1514 * Busy state exporting function for request stacking drivers.
1516 * For efficiency, no lock is taken to check the busy state of
1517 * shost/starget/sdev, since the returned value is not guaranteed and
1518 * may be changed after request stacking drivers call the function,
1519 * regardless of taking lock or not.
1521 * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi
1522 * needs to return 'not busy'. Otherwise, request stacking drivers
1523 * may hold requests forever.
1525 static int scsi_lld_busy(struct request_queue *q)
1527 struct scsi_device *sdev = q->queuedata;
1528 struct Scsi_Host *shost;
1530 if (blk_queue_dying(q))
1536 * Ignore host/starget busy state.
1537 * Since block layer does not have a concept of fairness across
1538 * multiple queues, congestion of host/starget needs to be handled
1541 if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev))
1548 * Kill a request for a dead device
1550 static void scsi_kill_request(struct request *req, struct request_queue *q)
1552 struct scsi_cmnd *cmd = req->special;
1553 struct scsi_device *sdev;
1554 struct scsi_target *starget;
1555 struct Scsi_Host *shost;
1557 blk_start_request(req);
1559 scmd_printk(KERN_INFO, cmd, "killing request\n");
1562 starget = scsi_target(sdev);
1564 scsi_init_cmd_errh(cmd);
1565 cmd->result = DID_NO_CONNECT << 16;
1566 atomic_inc(&cmd->device->iorequest_cnt);
1569 * SCSI request completion path will do scsi_device_unbusy(),
1570 * bump busy counts. To bump the counters, we need to dance
1571 * with the locks as normal issue path does.
1573 atomic_inc(&sdev->device_busy);
1574 atomic_inc(&shost->host_busy);
1575 if (starget->can_queue > 0)
1576 atomic_inc(&starget->target_busy);
1578 blk_complete_request(req);
1581 static void scsi_softirq_done(struct request *rq)
1583 struct scsi_cmnd *cmd = rq->special;
1584 unsigned long wait_for = (cmd->allowed + 1) * rq->timeout;
1587 INIT_LIST_HEAD(&cmd->eh_entry);
1589 atomic_inc(&cmd->device->iodone_cnt);
1591 atomic_inc(&cmd->device->ioerr_cnt);
1593 disposition = scsi_decide_disposition(cmd);
1594 if (disposition != SUCCESS &&
1595 time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) {
1596 sdev_printk(KERN_ERR, cmd->device,
1597 "timing out command, waited %lus\n",
1599 disposition = SUCCESS;
1602 scsi_log_completion(cmd, disposition);
1604 switch (disposition) {
1606 scsi_finish_command(cmd);
1609 scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY);
1611 case ADD_TO_MLQUEUE:
1612 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
1615 scsi_eh_scmd_add(cmd);
1621 * scsi_dispatch_command - Dispatch a command to the low-level driver.
1622 * @cmd: command block we are dispatching.
1624 * Return: nonzero return request was rejected and device's queue needs to be
1627 static int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
1629 struct Scsi_Host *host = cmd->device->host;
1632 atomic_inc(&cmd->device->iorequest_cnt);
1634 /* check if the device is still usable */
1635 if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
1636 /* in SDEV_DEL we error all commands. DID_NO_CONNECT
1637 * returns an immediate error upwards, and signals
1638 * that the device is no longer present */
1639 cmd->result = DID_NO_CONNECT << 16;
1643 /* Check to see if the scsi lld made this device blocked. */
1644 if (unlikely(scsi_device_blocked(cmd->device))) {
1646 * in blocked state, the command is just put back on
1647 * the device queue. The suspend state has already
1648 * blocked the queue so future requests should not
1649 * occur until the device transitions out of the
1652 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
1653 "queuecommand : device blocked\n"));
1654 return SCSI_MLQUEUE_DEVICE_BUSY;
1657 /* Store the LUN value in cmnd, if needed. */
1658 if (cmd->device->lun_in_cdb)
1659 cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
1660 (cmd->device->lun << 5 & 0xe0);
1665 * Before we queue this command, check if the command
1666 * length exceeds what the host adapter can handle.
1668 if (cmd->cmd_len > cmd->device->host->max_cmd_len) {
1669 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
1670 "queuecommand : command too long. "
1671 "cdb_size=%d host->max_cmd_len=%d\n",
1672 cmd->cmd_len, cmd->device->host->max_cmd_len));
1673 cmd->result = (DID_ABORT << 16);
1677 if (unlikely(host->shost_state == SHOST_DEL)) {
1678 cmd->result = (DID_NO_CONNECT << 16);
1683 trace_scsi_dispatch_cmd_start(cmd);
1684 rtn = host->hostt->queuecommand(host, cmd);
1686 trace_scsi_dispatch_cmd_error(cmd, rtn);
1687 if (rtn != SCSI_MLQUEUE_DEVICE_BUSY &&
1688 rtn != SCSI_MLQUEUE_TARGET_BUSY)
1689 rtn = SCSI_MLQUEUE_HOST_BUSY;
1691 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
1692 "queuecommand : request rejected\n"));
1697 cmd->scsi_done(cmd);
1702 * scsi_done - Invoke completion on finished SCSI command.
1703 * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives
1704 * ownership back to SCSI Core -- i.e. the LLDD has finished with it.
1706 * Description: This function is the mid-level's (SCSI Core) interrupt routine,
1707 * which regains ownership of the SCSI command (de facto) from a LLDD, and
1708 * calls blk_complete_request() for further processing.
1710 * This function is interrupt context safe.
1712 static void scsi_done(struct scsi_cmnd *cmd)
1714 trace_scsi_dispatch_cmd_done(cmd);
1715 blk_complete_request(cmd->request);
1719 * Function: scsi_request_fn()
1721 * Purpose: Main strategy routine for SCSI.
1723 * Arguments: q - Pointer to actual queue.
1727 * Lock status: IO request lock assumed to be held when called.
1729 static void scsi_request_fn(struct request_queue *q)
1730 __releases(q->queue_lock)
1731 __acquires(q->queue_lock)
1733 struct scsi_device *sdev = q->queuedata;
1734 struct Scsi_Host *shost;
1735 struct scsi_cmnd *cmd;
1736 struct request *req;
1739 * To start with, we keep looping until the queue is empty, or until
1740 * the host is no longer able to accept any more requests.
1746 * get next queueable request. We do this early to make sure
1747 * that the request is fully prepared even if we cannot
1750 req = blk_peek_request(q);
1754 if (unlikely(!scsi_device_online(sdev))) {
1755 sdev_printk(KERN_ERR, sdev,
1756 "rejecting I/O to offline device\n");
1757 scsi_kill_request(req, q);
1761 if (!scsi_dev_queue_ready(q, sdev))
1765 * Remove the request from the request list.
1767 if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req)))
1768 blk_start_request(req);
1770 spin_unlock_irq(q->queue_lock);
1772 if (unlikely(cmd == NULL)) {
1773 printk(KERN_CRIT "impossible request in %s.\n"
1774 "please mail a stack trace to "
1775 "linux-scsi@vger.kernel.org\n",
1777 blk_dump_rq_flags(req, "foo");
1782 * We hit this when the driver is using a host wide
1783 * tag map. For device level tag maps the queue_depth check
1784 * in the device ready fn would prevent us from trying
1785 * to allocate a tag. Since the map is a shared host resource
1786 * we add the dev to the starved list so it eventually gets
1787 * a run when a tag is freed.
1789 if (blk_queue_tagged(q) && !(req->rq_flags & RQF_QUEUED)) {
1790 spin_lock_irq(shost->host_lock);
1791 if (list_empty(&sdev->starved_entry))
1792 list_add_tail(&sdev->starved_entry,
1793 &shost->starved_list);
1794 spin_unlock_irq(shost->host_lock);
1798 if (!scsi_target_queue_ready(shost, sdev))
1801 if (!scsi_host_queue_ready(q, shost, sdev))
1802 goto host_not_ready;
1804 if (sdev->simple_tags)
1805 cmd->flags |= SCMD_TAGGED;
1807 cmd->flags &= ~SCMD_TAGGED;
1810 * Finally, initialize any error handling parameters, and set up
1811 * the timers for timeouts.
1813 scsi_init_cmd_errh(cmd);
1816 * Dispatch the command to the low-level driver.
1818 cmd->scsi_done = scsi_done;
1819 rtn = scsi_dispatch_cmd(cmd);
1821 scsi_queue_insert(cmd, rtn);
1822 spin_lock_irq(q->queue_lock);
1825 spin_lock_irq(q->queue_lock);
1831 if (scsi_target(sdev)->can_queue > 0)
1832 atomic_dec(&scsi_target(sdev)->target_busy);
1835 * lock q, handle tag, requeue req, and decrement device_busy. We
1836 * must return with queue_lock held.
1838 * Decrementing device_busy without checking it is OK, as all such
1839 * cases (host limits or settings) should run the queue at some
1842 spin_lock_irq(q->queue_lock);
1843 blk_requeue_request(q, req);
1844 atomic_dec(&sdev->device_busy);
1846 if (!atomic_read(&sdev->device_busy) && !scsi_device_blocked(sdev))
1847 blk_delay_queue(q, SCSI_QUEUE_DELAY);
1850 static inline int prep_to_mq(int ret)
1854 return BLK_MQ_RQ_QUEUE_OK;
1856 return BLK_MQ_RQ_QUEUE_BUSY;
1858 return BLK_MQ_RQ_QUEUE_ERROR;
1862 /* Size in bytes of the sg-list stored in the scsi-mq command-private data. */
1863 static unsigned int scsi_mq_sgl_size(struct Scsi_Host *shost)
1865 return min_t(unsigned int, shost->sg_tablesize, SG_CHUNK_SIZE) *
1866 sizeof(struct scatterlist);
1869 static int scsi_mq_prep_fn(struct request *req)
1871 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
1872 struct scsi_device *sdev = req->q->queuedata;
1873 struct Scsi_Host *shost = sdev->host;
1874 struct scatterlist *sg;
1876 scsi_init_command(sdev, cmd);
1882 cmd->tag = req->tag;
1883 cmd->prot_op = SCSI_PROT_NORMAL;
1885 sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size;
1886 cmd->sdb.table.sgl = sg;
1888 if (scsi_host_get_prot(shost)) {
1889 memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer));
1891 cmd->prot_sdb->table.sgl =
1892 (struct scatterlist *)(cmd->prot_sdb + 1);
1895 if (blk_bidi_rq(req)) {
1896 struct request *next_rq = req->next_rq;
1897 struct scsi_data_buffer *bidi_sdb = blk_mq_rq_to_pdu(next_rq);
1899 memset(bidi_sdb, 0, sizeof(struct scsi_data_buffer));
1900 bidi_sdb->table.sgl =
1901 (struct scatterlist *)(bidi_sdb + 1);
1903 next_rq->special = bidi_sdb;
1906 blk_mq_start_request(req);
1908 return scsi_setup_cmnd(sdev, req);
1911 static void scsi_mq_done(struct scsi_cmnd *cmd)
1913 trace_scsi_dispatch_cmd_done(cmd);
1914 blk_mq_complete_request(cmd->request);
1917 static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
1918 const struct blk_mq_queue_data *bd)
1920 struct request *req = bd->rq;
1921 struct request_queue *q = req->q;
1922 struct scsi_device *sdev = q->queuedata;
1923 struct Scsi_Host *shost = sdev->host;
1924 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
1928 ret = prep_to_mq(scsi_prep_state_check(sdev, req));
1929 if (ret != BLK_MQ_RQ_QUEUE_OK)
1932 ret = BLK_MQ_RQ_QUEUE_BUSY;
1933 if (!get_device(&sdev->sdev_gendev))
1936 if (!scsi_dev_queue_ready(q, sdev))
1937 goto out_put_device;
1938 if (!scsi_target_queue_ready(shost, sdev))
1939 goto out_dec_device_busy;
1940 if (!scsi_host_queue_ready(q, shost, sdev))
1941 goto out_dec_target_busy;
1943 if (!(req->rq_flags & RQF_DONTPREP)) {
1944 ret = prep_to_mq(scsi_mq_prep_fn(req));
1945 if (ret != BLK_MQ_RQ_QUEUE_OK)
1946 goto out_dec_host_busy;
1947 req->rq_flags |= RQF_DONTPREP;
1949 blk_mq_start_request(req);
1952 if (sdev->simple_tags)
1953 cmd->flags |= SCMD_TAGGED;
1955 cmd->flags &= ~SCMD_TAGGED;
1957 scsi_init_cmd_errh(cmd);
1958 cmd->scsi_done = scsi_mq_done;
1960 reason = scsi_dispatch_cmd(cmd);
1962 scsi_set_blocked(cmd, reason);
1963 ret = BLK_MQ_RQ_QUEUE_BUSY;
1964 goto out_dec_host_busy;
1967 return BLK_MQ_RQ_QUEUE_OK;
1970 atomic_dec(&shost->host_busy);
1971 out_dec_target_busy:
1972 if (scsi_target(sdev)->can_queue > 0)
1973 atomic_dec(&scsi_target(sdev)->target_busy);
1974 out_dec_device_busy:
1975 atomic_dec(&sdev->device_busy);
1977 put_device(&sdev->sdev_gendev);
1980 case BLK_MQ_RQ_QUEUE_BUSY:
1981 if (atomic_read(&sdev->device_busy) == 0 &&
1982 !scsi_device_blocked(sdev))
1983 blk_mq_delay_run_hw_queue(hctx, SCSI_QUEUE_DELAY);
1985 case BLK_MQ_RQ_QUEUE_ERROR:
1987 * Make sure to release all allocated ressources when
1988 * we hit an error, as we will never see this command
1991 if (req->rq_flags & RQF_DONTPREP)
1992 scsi_mq_uninit_cmd(cmd);
2000 static enum blk_eh_timer_return scsi_timeout(struct request *req,
2004 return BLK_EH_RESET_TIMER;
2005 return scsi_times_out(req);
2008 static int scsi_init_request(struct blk_mq_tag_set *set, struct request *rq,
2009 unsigned int hctx_idx, unsigned int numa_node)
2011 struct Scsi_Host *shost = set->driver_data;
2012 const bool unchecked_isa_dma = shost->unchecked_isa_dma;
2013 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
2014 struct scatterlist *sg;
2016 if (unchecked_isa_dma)
2017 cmd->flags |= SCMD_UNCHECKED_ISA_DMA;
2018 cmd->sense_buffer = scsi_alloc_sense_buffer(unchecked_isa_dma,
2019 GFP_KERNEL, numa_node);
2020 if (!cmd->sense_buffer)
2022 cmd->req.sense = cmd->sense_buffer;
2024 if (scsi_host_get_prot(shost)) {
2025 sg = (void *)cmd + sizeof(struct scsi_cmnd) +
2026 shost->hostt->cmd_size;
2027 cmd->prot_sdb = (void *)sg + scsi_mq_sgl_size(shost);
2033 static void scsi_exit_request(struct blk_mq_tag_set *set, struct request *rq,
2034 unsigned int hctx_idx)
2036 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
2038 scsi_free_sense_buffer(cmd->flags & SCMD_UNCHECKED_ISA_DMA,
2042 static int scsi_map_queues(struct blk_mq_tag_set *set)
2044 struct Scsi_Host *shost = container_of(set, struct Scsi_Host, tag_set);
2046 if (shost->hostt->map_queues)
2047 return shost->hostt->map_queues(shost);
2048 return blk_mq_map_queues(set);
2051 static u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost)
2053 struct device *host_dev;
2054 u64 bounce_limit = 0xffffffff;
2056 if (shost->unchecked_isa_dma)
2057 return BLK_BOUNCE_ISA;
2059 * Platforms with virtual-DMA translation
2060 * hardware have no practical limit.
2062 if (!PCI_DMA_BUS_IS_PHYS)
2063 return BLK_BOUNCE_ANY;
2065 host_dev = scsi_get_device(shost);
2066 if (host_dev && host_dev->dma_mask)
2067 bounce_limit = (u64)dma_max_pfn(host_dev) << PAGE_SHIFT;
2069 return bounce_limit;
2072 void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q)
2074 struct device *dev = shost->dma_dev;
2077 * this limit is imposed by hardware restrictions
2079 blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize,
2082 if (scsi_host_prot_dma(shost)) {
2083 shost->sg_prot_tablesize =
2084 min_not_zero(shost->sg_prot_tablesize,
2085 (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS);
2086 BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize);
2087 blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize);
2090 blk_queue_max_hw_sectors(q, shost->max_sectors);
2091 blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost));
2092 blk_queue_segment_boundary(q, shost->dma_boundary);
2093 dma_set_seg_boundary(dev, shost->dma_boundary);
2095 blk_queue_max_segment_size(q, dma_get_max_seg_size(dev));
2097 if (!shost->use_clustering)
2098 q->limits.cluster = 0;
2101 * set a reasonable default alignment on word boundaries: the
2102 * host and device may alter it using
2103 * blk_queue_update_dma_alignment() later.
2105 blk_queue_dma_alignment(q, 0x03);
2107 EXPORT_SYMBOL_GPL(__scsi_init_queue);
2109 static int scsi_init_rq(struct request_queue *q, struct request *rq, gfp_t gfp)
2111 struct Scsi_Host *shost = q->rq_alloc_data;
2112 const bool unchecked_isa_dma = shost->unchecked_isa_dma;
2113 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
2115 memset(cmd, 0, sizeof(*cmd));
2117 if (unchecked_isa_dma)
2118 cmd->flags |= SCMD_UNCHECKED_ISA_DMA;
2119 cmd->sense_buffer = scsi_alloc_sense_buffer(unchecked_isa_dma, gfp,
2121 if (!cmd->sense_buffer)
2123 cmd->req.sense = cmd->sense_buffer;
2125 if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) {
2126 cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp);
2128 goto fail_free_sense;
2134 scsi_free_sense_buffer(unchecked_isa_dma, cmd->sense_buffer);
2139 static void scsi_exit_rq(struct request_queue *q, struct request *rq)
2141 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
2144 kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb);
2145 scsi_free_sense_buffer(cmd->flags & SCMD_UNCHECKED_ISA_DMA,
2149 struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
2151 struct Scsi_Host *shost = sdev->host;
2152 struct request_queue *q;
2154 q = blk_alloc_queue_node(GFP_KERNEL, NUMA_NO_NODE);
2157 q->cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size;
2158 q->rq_alloc_data = shost;
2159 q->request_fn = scsi_request_fn;
2160 q->init_rq_fn = scsi_init_rq;
2161 q->exit_rq_fn = scsi_exit_rq;
2163 if (blk_init_allocated_queue(q) < 0) {
2164 blk_cleanup_queue(q);
2168 __scsi_init_queue(shost, q);
2169 blk_queue_prep_rq(q, scsi_prep_fn);
2170 blk_queue_unprep_rq(q, scsi_unprep_fn);
2171 blk_queue_softirq_done(q, scsi_softirq_done);
2172 blk_queue_rq_timed_out(q, scsi_times_out);
2173 blk_queue_lld_busy(q, scsi_lld_busy);
2177 static const struct blk_mq_ops scsi_mq_ops = {
2178 .queue_rq = scsi_queue_rq,
2179 .complete = scsi_softirq_done,
2180 .timeout = scsi_timeout,
2181 #ifdef CONFIG_BLK_DEBUG_FS
2182 .show_rq = scsi_show_rq,
2184 .init_request = scsi_init_request,
2185 .exit_request = scsi_exit_request,
2186 .map_queues = scsi_map_queues,
2189 struct request_queue *scsi_mq_alloc_queue(struct scsi_device *sdev)
2191 sdev->request_queue = blk_mq_init_queue(&sdev->host->tag_set);
2192 if (IS_ERR(sdev->request_queue))
2195 sdev->request_queue->queuedata = sdev;
2196 __scsi_init_queue(sdev->host, sdev->request_queue);
2197 return sdev->request_queue;
2200 int scsi_mq_setup_tags(struct Scsi_Host *shost)
2202 unsigned int cmd_size, sgl_size;
2204 sgl_size = scsi_mq_sgl_size(shost);
2205 cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size + sgl_size;
2206 if (scsi_host_get_prot(shost))
2207 cmd_size += sizeof(struct scsi_data_buffer) + sgl_size;
2209 memset(&shost->tag_set, 0, sizeof(shost->tag_set));
2210 shost->tag_set.ops = &scsi_mq_ops;
2211 shost->tag_set.nr_hw_queues = shost->nr_hw_queues ? : 1;
2212 shost->tag_set.queue_depth = shost->can_queue;
2213 shost->tag_set.cmd_size = cmd_size;
2214 shost->tag_set.numa_node = NUMA_NO_NODE;
2215 shost->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
2216 shost->tag_set.flags |=
2217 BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy);
2218 shost->tag_set.driver_data = shost;
2220 return blk_mq_alloc_tag_set(&shost->tag_set);
2223 void scsi_mq_destroy_tags(struct Scsi_Host *shost)
2225 blk_mq_free_tag_set(&shost->tag_set);
2229 * scsi_device_from_queue - return sdev associated with a request_queue
2230 * @q: The request queue to return the sdev from
2232 * Return the sdev associated with a request queue or NULL if the
2233 * request_queue does not reference a SCSI device.
2235 struct scsi_device *scsi_device_from_queue(struct request_queue *q)
2237 struct scsi_device *sdev = NULL;
2240 if (q->mq_ops == &scsi_mq_ops)
2241 sdev = q->queuedata;
2242 } else if (q->request_fn == scsi_request_fn)
2243 sdev = q->queuedata;
2244 if (!sdev || !get_device(&sdev->sdev_gendev))
2249 EXPORT_SYMBOL_GPL(scsi_device_from_queue);
2252 * Function: scsi_block_requests()
2254 * Purpose: Utility function used by low-level drivers to prevent further
2255 * commands from being queued to the device.
2257 * Arguments: shost - Host in question
2261 * Lock status: No locks are assumed held.
2263 * Notes: There is no timer nor any other means by which the requests
2264 * get unblocked other than the low-level driver calling
2265 * scsi_unblock_requests().
2267 void scsi_block_requests(struct Scsi_Host *shost)
2269 shost->host_self_blocked = 1;
2271 EXPORT_SYMBOL(scsi_block_requests);
2274 * Function: scsi_unblock_requests()
2276 * Purpose: Utility function used by low-level drivers to allow further
2277 * commands from being queued to the device.
2279 * Arguments: shost - Host in question
2283 * Lock status: No locks are assumed held.
2285 * Notes: There is no timer nor any other means by which the requests
2286 * get unblocked other than the low-level driver calling
2287 * scsi_unblock_requests().
2289 * This is done as an API function so that changes to the
2290 * internals of the scsi mid-layer won't require wholesale
2291 * changes to drivers that use this feature.
2293 void scsi_unblock_requests(struct Scsi_Host *shost)
2295 shost->host_self_blocked = 0;
2296 scsi_run_host_queues(shost);
2298 EXPORT_SYMBOL(scsi_unblock_requests);
2300 int __init scsi_init_queue(void)
2302 scsi_sdb_cache = kmem_cache_create("scsi_data_buffer",
2303 sizeof(struct scsi_data_buffer),
2305 if (!scsi_sdb_cache) {
2306 printk(KERN_ERR "SCSI: can't init scsi sdb cache\n");
2313 void scsi_exit_queue(void)
2315 kmem_cache_destroy(scsi_sense_cache);
2316 kmem_cache_destroy(scsi_sense_isadma_cache);
2317 kmem_cache_destroy(scsi_sdb_cache);
2321 * scsi_mode_select - issue a mode select
2322 * @sdev: SCSI device to be queried
2323 * @pf: Page format bit (1 == standard, 0 == vendor specific)
2324 * @sp: Save page bit (0 == don't save, 1 == save)
2325 * @modepage: mode page being requested
2326 * @buffer: request buffer (may not be smaller than eight bytes)
2327 * @len: length of request buffer.
2328 * @timeout: command timeout
2329 * @retries: number of retries before failing
2330 * @data: returns a structure abstracting the mode header data
2331 * @sshdr: place to put sense data (or NULL if no sense to be collected).
2332 * must be SCSI_SENSE_BUFFERSIZE big.
2334 * Returns zero if successful; negative error number or scsi
2339 scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage,
2340 unsigned char *buffer, int len, int timeout, int retries,
2341 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
2343 unsigned char cmd[10];
2344 unsigned char *real_buffer;
2347 memset(cmd, 0, sizeof(cmd));
2348 cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0);
2350 if (sdev->use_10_for_ms) {
2353 real_buffer = kmalloc(8 + len, GFP_KERNEL);
2356 memcpy(real_buffer + 8, buffer, len);
2360 real_buffer[2] = data->medium_type;
2361 real_buffer[3] = data->device_specific;
2362 real_buffer[4] = data->longlba ? 0x01 : 0;
2364 real_buffer[6] = data->block_descriptor_length >> 8;
2365 real_buffer[7] = data->block_descriptor_length;
2367 cmd[0] = MODE_SELECT_10;
2371 if (len > 255 || data->block_descriptor_length > 255 ||
2375 real_buffer = kmalloc(4 + len, GFP_KERNEL);
2378 memcpy(real_buffer + 4, buffer, len);
2381 real_buffer[1] = data->medium_type;
2382 real_buffer[2] = data->device_specific;
2383 real_buffer[3] = data->block_descriptor_length;
2386 cmd[0] = MODE_SELECT;
2390 ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len,
2391 sshdr, timeout, retries, NULL);
2395 EXPORT_SYMBOL_GPL(scsi_mode_select);
2398 * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary.
2399 * @sdev: SCSI device to be queried
2400 * @dbd: set if mode sense will allow block descriptors to be returned
2401 * @modepage: mode page being requested
2402 * @buffer: request buffer (may not be smaller than eight bytes)
2403 * @len: length of request buffer.
2404 * @timeout: command timeout
2405 * @retries: number of retries before failing
2406 * @data: returns a structure abstracting the mode header data
2407 * @sshdr: place to put sense data (or NULL if no sense to be collected).
2408 * must be SCSI_SENSE_BUFFERSIZE big.
2410 * Returns zero if unsuccessful, or the header offset (either 4
2411 * or 8 depending on whether a six or ten byte command was
2412 * issued) if successful.
2415 scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
2416 unsigned char *buffer, int len, int timeout, int retries,
2417 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
2419 unsigned char cmd[12];
2422 int result, retry_count = retries;
2423 struct scsi_sense_hdr my_sshdr;
2425 memset(data, 0, sizeof(*data));
2426 memset(&cmd[0], 0, 12);
2427 cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */
2430 /* caller might not be interested in sense, but we need it */
2435 use_10_for_ms = sdev->use_10_for_ms;
2437 if (use_10_for_ms) {
2441 cmd[0] = MODE_SENSE_10;
2448 cmd[0] = MODE_SENSE;
2453 memset(buffer, 0, len);
2455 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len,
2456 sshdr, timeout, retries, NULL);
2458 /* This code looks awful: what it's doing is making sure an
2459 * ILLEGAL REQUEST sense return identifies the actual command
2460 * byte as the problem. MODE_SENSE commands can return
2461 * ILLEGAL REQUEST if the code page isn't supported */
2463 if (use_10_for_ms && !scsi_status_is_good(result) &&
2464 (driver_byte(result) & DRIVER_SENSE)) {
2465 if (scsi_sense_valid(sshdr)) {
2466 if ((sshdr->sense_key == ILLEGAL_REQUEST) &&
2467 (sshdr->asc == 0x20) && (sshdr->ascq == 0)) {
2469 * Invalid command operation code
2471 sdev->use_10_for_ms = 0;
2477 if(scsi_status_is_good(result)) {
2478 if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b &&
2479 (modepage == 6 || modepage == 8))) {
2480 /* Initio breakage? */
2483 data->medium_type = 0;
2484 data->device_specific = 0;
2486 data->block_descriptor_length = 0;
2487 } else if(use_10_for_ms) {
2488 data->length = buffer[0]*256 + buffer[1] + 2;
2489 data->medium_type = buffer[2];
2490 data->device_specific = buffer[3];
2491 data->longlba = buffer[4] & 0x01;
2492 data->block_descriptor_length = buffer[6]*256
2495 data->length = buffer[0] + 1;
2496 data->medium_type = buffer[1];
2497 data->device_specific = buffer[2];
2498 data->block_descriptor_length = buffer[3];
2500 data->header_length = header_length;
2501 } else if ((status_byte(result) == CHECK_CONDITION) &&
2502 scsi_sense_valid(sshdr) &&
2503 sshdr->sense_key == UNIT_ATTENTION && retry_count) {
2510 EXPORT_SYMBOL(scsi_mode_sense);
2513 * scsi_test_unit_ready - test if unit is ready
2514 * @sdev: scsi device to change the state of.
2515 * @timeout: command timeout
2516 * @retries: number of retries before failing
2517 * @sshdr: outpout pointer for decoded sense information.
2519 * Returns zero if unsuccessful or an error if TUR failed. For
2520 * removable media, UNIT_ATTENTION sets ->changed flag.
2523 scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries,
2524 struct scsi_sense_hdr *sshdr)
2527 TEST_UNIT_READY, 0, 0, 0, 0, 0,
2531 /* try to eat the UNIT_ATTENTION if there are enough retries */
2533 result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr,
2534 timeout, retries, NULL);
2535 if (sdev->removable && scsi_sense_valid(sshdr) &&
2536 sshdr->sense_key == UNIT_ATTENTION)
2538 } while (scsi_sense_valid(sshdr) &&
2539 sshdr->sense_key == UNIT_ATTENTION && --retries);
2543 EXPORT_SYMBOL(scsi_test_unit_ready);
2546 * scsi_device_set_state - Take the given device through the device state model.
2547 * @sdev: scsi device to change the state of.
2548 * @state: state to change to.
2550 * Returns zero if unsuccessful or an error if the requested
2551 * transition is illegal.
2554 scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
2556 enum scsi_device_state oldstate = sdev->sdev_state;
2558 if (state == oldstate)
2564 case SDEV_CREATED_BLOCK:
2575 case SDEV_TRANSPORT_OFFLINE:
2588 case SDEV_TRANSPORT_OFFLINE:
2596 case SDEV_TRANSPORT_OFFLINE:
2611 case SDEV_CREATED_BLOCK:
2618 case SDEV_CREATED_BLOCK:
2633 case SDEV_TRANSPORT_OFFLINE:
2645 case SDEV_TRANSPORT_OFFLINE:
2648 case SDEV_CREATED_BLOCK:
2656 sdev->sdev_state = state;
2660 SCSI_LOG_ERROR_RECOVERY(1,
2661 sdev_printk(KERN_ERR, sdev,
2662 "Illegal state transition %s->%s",
2663 scsi_device_state_name(oldstate),
2664 scsi_device_state_name(state))
2668 EXPORT_SYMBOL(scsi_device_set_state);
2671 * sdev_evt_emit - emit a single SCSI device uevent
2672 * @sdev: associated SCSI device
2673 * @evt: event to emit
2675 * Send a single uevent (scsi_event) to the associated scsi_device.
2677 static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt)
2682 switch (evt->evt_type) {
2683 case SDEV_EVT_MEDIA_CHANGE:
2684 envp[idx++] = "SDEV_MEDIA_CHANGE=1";
2686 case SDEV_EVT_INQUIRY_CHANGE_REPORTED:
2687 scsi_rescan_device(&sdev->sdev_gendev);
2688 envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED";
2690 case SDEV_EVT_CAPACITY_CHANGE_REPORTED:
2691 envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED";
2693 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED:
2694 envp[idx++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED";
2696 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED:
2697 envp[idx++] = "SDEV_UA=MODE_PARAMETERS_CHANGED";
2699 case SDEV_EVT_LUN_CHANGE_REPORTED:
2700 envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED";
2702 case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED:
2703 envp[idx++] = "SDEV_UA=ASYMMETRIC_ACCESS_STATE_CHANGED";
2712 kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp);
2716 * sdev_evt_thread - send a uevent for each scsi event
2717 * @work: work struct for scsi_device
2719 * Dispatch queued events to their associated scsi_device kobjects
2722 void scsi_evt_thread(struct work_struct *work)
2724 struct scsi_device *sdev;
2725 enum scsi_device_event evt_type;
2726 LIST_HEAD(event_list);
2728 sdev = container_of(work, struct scsi_device, event_work);
2730 for (evt_type = SDEV_EVT_FIRST; evt_type <= SDEV_EVT_LAST; evt_type++)
2731 if (test_and_clear_bit(evt_type, sdev->pending_events))
2732 sdev_evt_send_simple(sdev, evt_type, GFP_KERNEL);
2735 struct scsi_event *evt;
2736 struct list_head *this, *tmp;
2737 unsigned long flags;
2739 spin_lock_irqsave(&sdev->list_lock, flags);
2740 list_splice_init(&sdev->event_list, &event_list);
2741 spin_unlock_irqrestore(&sdev->list_lock, flags);
2743 if (list_empty(&event_list))
2746 list_for_each_safe(this, tmp, &event_list) {
2747 evt = list_entry(this, struct scsi_event, node);
2748 list_del(&evt->node);
2749 scsi_evt_emit(sdev, evt);
2756 * sdev_evt_send - send asserted event to uevent thread
2757 * @sdev: scsi_device event occurred on
2758 * @evt: event to send
2760 * Assert scsi device event asynchronously.
2762 void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt)
2764 unsigned long flags;
2767 /* FIXME: currently this check eliminates all media change events
2768 * for polled devices. Need to update to discriminate between AN
2769 * and polled events */
2770 if (!test_bit(evt->evt_type, sdev->supported_events)) {
2776 spin_lock_irqsave(&sdev->list_lock, flags);
2777 list_add_tail(&evt->node, &sdev->event_list);
2778 schedule_work(&sdev->event_work);
2779 spin_unlock_irqrestore(&sdev->list_lock, flags);
2781 EXPORT_SYMBOL_GPL(sdev_evt_send);
2784 * sdev_evt_alloc - allocate a new scsi event
2785 * @evt_type: type of event to allocate
2786 * @gfpflags: GFP flags for allocation
2788 * Allocates and returns a new scsi_event.
2790 struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type,
2793 struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags);
2797 evt->evt_type = evt_type;
2798 INIT_LIST_HEAD(&evt->node);
2800 /* evt_type-specific initialization, if any */
2802 case SDEV_EVT_MEDIA_CHANGE:
2803 case SDEV_EVT_INQUIRY_CHANGE_REPORTED:
2804 case SDEV_EVT_CAPACITY_CHANGE_REPORTED:
2805 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED:
2806 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED:
2807 case SDEV_EVT_LUN_CHANGE_REPORTED:
2808 case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED:
2816 EXPORT_SYMBOL_GPL(sdev_evt_alloc);
2819 * sdev_evt_send_simple - send asserted event to uevent thread
2820 * @sdev: scsi_device event occurred on
2821 * @evt_type: type of event to send
2822 * @gfpflags: GFP flags for allocation
2824 * Assert scsi device event asynchronously, given an event type.
2826 void sdev_evt_send_simple(struct scsi_device *sdev,
2827 enum scsi_device_event evt_type, gfp_t gfpflags)
2829 struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags);
2831 sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n",
2836 sdev_evt_send(sdev, evt);
2838 EXPORT_SYMBOL_GPL(sdev_evt_send_simple);
2841 * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn()
2842 * @sdev: SCSI device to count the number of scsi_request_fn() callers for.
2844 static int scsi_request_fn_active(struct scsi_device *sdev)
2846 struct request_queue *q = sdev->request_queue;
2847 int request_fn_active;
2849 WARN_ON_ONCE(sdev->host->use_blk_mq);
2851 spin_lock_irq(q->queue_lock);
2852 request_fn_active = q->request_fn_active;
2853 spin_unlock_irq(q->queue_lock);
2855 return request_fn_active;
2859 * scsi_wait_for_queuecommand() - wait for ongoing queuecommand() calls
2860 * @sdev: SCSI device pointer.
2862 * Wait until the ongoing shost->hostt->queuecommand() calls that are
2863 * invoked from scsi_request_fn() have finished.
2865 static void scsi_wait_for_queuecommand(struct scsi_device *sdev)
2867 WARN_ON_ONCE(sdev->host->use_blk_mq);
2869 while (scsi_request_fn_active(sdev))
2874 * scsi_device_quiesce - Block user issued commands.
2875 * @sdev: scsi device to quiesce.
2877 * This works by trying to transition to the SDEV_QUIESCE state
2878 * (which must be a legal transition). When the device is in this
2879 * state, only special requests will be accepted, all others will
2880 * be deferred. Since special requests may also be requeued requests,
2881 * a successful return doesn't guarantee the device will be
2882 * totally quiescent.
2884 * Must be called with user context, may sleep.
2886 * Returns zero if unsuccessful or an error if not.
2889 scsi_device_quiesce(struct scsi_device *sdev)
2893 mutex_lock(&sdev->state_mutex);
2894 err = scsi_device_set_state(sdev, SDEV_QUIESCE);
2895 mutex_unlock(&sdev->state_mutex);
2900 scsi_run_queue(sdev->request_queue);
2901 while (atomic_read(&sdev->device_busy)) {
2902 msleep_interruptible(200);
2903 scsi_run_queue(sdev->request_queue);
2907 EXPORT_SYMBOL(scsi_device_quiesce);
2910 * scsi_device_resume - Restart user issued commands to a quiesced device.
2911 * @sdev: scsi device to resume.
2913 * Moves the device from quiesced back to running and restarts the
2916 * Must be called with user context, may sleep.
2918 void scsi_device_resume(struct scsi_device *sdev)
2920 /* check if the device state was mutated prior to resume, and if
2921 * so assume the state is being managed elsewhere (for example
2922 * device deleted during suspend)
2924 mutex_lock(&sdev->state_mutex);
2925 if (sdev->sdev_state == SDEV_QUIESCE &&
2926 scsi_device_set_state(sdev, SDEV_RUNNING) == 0)
2927 scsi_run_queue(sdev->request_queue);
2928 mutex_unlock(&sdev->state_mutex);
2930 EXPORT_SYMBOL(scsi_device_resume);
2933 device_quiesce_fn(struct scsi_device *sdev, void *data)
2935 scsi_device_quiesce(sdev);
2939 scsi_target_quiesce(struct scsi_target *starget)
2941 starget_for_each_device(starget, NULL, device_quiesce_fn);
2943 EXPORT_SYMBOL(scsi_target_quiesce);
2946 device_resume_fn(struct scsi_device *sdev, void *data)
2948 scsi_device_resume(sdev);
2952 scsi_target_resume(struct scsi_target *starget)
2954 starget_for_each_device(starget, NULL, device_resume_fn);
2956 EXPORT_SYMBOL(scsi_target_resume);
2959 * scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state
2960 * @sdev: device to block
2962 * Pause SCSI command processing on the specified device. Does not sleep.
2964 * Returns zero if successful or a negative error code upon failure.
2967 * This routine transitions the device to the SDEV_BLOCK state (which must be
2968 * a legal transition). When the device is in this state, command processing
2969 * is paused until the device leaves the SDEV_BLOCK state. See also
2970 * scsi_internal_device_unblock_nowait().
2972 int scsi_internal_device_block_nowait(struct scsi_device *sdev)
2974 struct request_queue *q = sdev->request_queue;
2975 unsigned long flags;
2978 err = scsi_device_set_state(sdev, SDEV_BLOCK);
2980 err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK);
2987 * The device has transitioned to SDEV_BLOCK. Stop the
2988 * block layer from calling the midlayer with this device's
2992 blk_mq_stop_hw_queues(q);
2994 spin_lock_irqsave(q->queue_lock, flags);
2996 spin_unlock_irqrestore(q->queue_lock, flags);
3001 EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait);
3004 * scsi_internal_device_block - try to transition to the SDEV_BLOCK state
3005 * @sdev: device to block
3007 * Pause SCSI command processing on the specified device and wait until all
3008 * ongoing scsi_request_fn() / scsi_queue_rq() calls have finished. May sleep.
3010 * Returns zero if successful or a negative error code upon failure.
3013 * This routine transitions the device to the SDEV_BLOCK state (which must be
3014 * a legal transition). When the device is in this state, command processing
3015 * is paused until the device leaves the SDEV_BLOCK state. See also
3016 * scsi_internal_device_unblock().
3018 * To do: avoid that scsi_send_eh_cmnd() calls queuecommand() after
3019 * scsi_internal_device_block() has blocked a SCSI device and also
3020 * remove the rport mutex lock and unlock calls from srp_queuecommand().
3022 static int scsi_internal_device_block(struct scsi_device *sdev)
3024 struct request_queue *q = sdev->request_queue;
3027 mutex_lock(&sdev->state_mutex);
3028 err = scsi_internal_device_block_nowait(sdev);
3031 blk_mq_quiesce_queue(q);
3033 scsi_wait_for_queuecommand(sdev);
3035 mutex_unlock(&sdev->state_mutex);
3040 void scsi_start_queue(struct scsi_device *sdev)
3042 struct request_queue *q = sdev->request_queue;
3043 unsigned long flags;
3046 blk_mq_start_stopped_hw_queues(q, false);
3048 spin_lock_irqsave(q->queue_lock, flags);
3050 spin_unlock_irqrestore(q->queue_lock, flags);
3055 * scsi_internal_device_unblock_nowait - resume a device after a block request
3056 * @sdev: device to resume
3057 * @new_state: state to set the device to after unblocking
3059 * Restart the device queue for a previously suspended SCSI device. Does not
3062 * Returns zero if successful or a negative error code upon failure.
3065 * This routine transitions the device to the SDEV_RUNNING state or to one of
3066 * the offline states (which must be a legal transition) allowing the midlayer
3067 * to goose the queue for this device.
3069 int scsi_internal_device_unblock_nowait(struct scsi_device *sdev,
3070 enum scsi_device_state new_state)
3073 * Try to transition the scsi device to SDEV_RUNNING or one of the
3074 * offlined states and goose the device queue if successful.
3076 if ((sdev->sdev_state == SDEV_BLOCK) ||
3077 (sdev->sdev_state == SDEV_TRANSPORT_OFFLINE))
3078 sdev->sdev_state = new_state;
3079 else if (sdev->sdev_state == SDEV_CREATED_BLOCK) {
3080 if (new_state == SDEV_TRANSPORT_OFFLINE ||
3081 new_state == SDEV_OFFLINE)
3082 sdev->sdev_state = new_state;
3084 sdev->sdev_state = SDEV_CREATED;
3085 } else if (sdev->sdev_state != SDEV_CANCEL &&
3086 sdev->sdev_state != SDEV_OFFLINE)
3089 scsi_start_queue(sdev);
3093 EXPORT_SYMBOL_GPL(scsi_internal_device_unblock_nowait);
3096 * scsi_internal_device_unblock - resume a device after a block request
3097 * @sdev: device to resume
3098 * @new_state: state to set the device to after unblocking
3100 * Restart the device queue for a previously suspended SCSI device. May sleep.
3102 * Returns zero if successful or a negative error code upon failure.
3105 * This routine transitions the device to the SDEV_RUNNING state or to one of
3106 * the offline states (which must be a legal transition) allowing the midlayer
3107 * to goose the queue for this device.
3109 static int scsi_internal_device_unblock(struct scsi_device *sdev,
3110 enum scsi_device_state new_state)
3114 mutex_lock(&sdev->state_mutex);
3115 ret = scsi_internal_device_unblock_nowait(sdev, new_state);
3116 mutex_unlock(&sdev->state_mutex);
3122 device_block(struct scsi_device *sdev, void *data)
3124 scsi_internal_device_block(sdev);
3128 target_block(struct device *dev, void *data)
3130 if (scsi_is_target_device(dev))
3131 starget_for_each_device(to_scsi_target(dev), NULL,
3137 scsi_target_block(struct device *dev)
3139 if (scsi_is_target_device(dev))
3140 starget_for_each_device(to_scsi_target(dev), NULL,
3143 device_for_each_child(dev, NULL, target_block);
3145 EXPORT_SYMBOL_GPL(scsi_target_block);
3148 device_unblock(struct scsi_device *sdev, void *data)
3150 scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data);
3154 target_unblock(struct device *dev, void *data)
3156 if (scsi_is_target_device(dev))
3157 starget_for_each_device(to_scsi_target(dev), data,
3163 scsi_target_unblock(struct device *dev, enum scsi_device_state new_state)
3165 if (scsi_is_target_device(dev))
3166 starget_for_each_device(to_scsi_target(dev), &new_state,
3169 device_for_each_child(dev, &new_state, target_unblock);
3171 EXPORT_SYMBOL_GPL(scsi_target_unblock);
3174 * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt
3175 * @sgl: scatter-gather list
3176 * @sg_count: number of segments in sg
3177 * @offset: offset in bytes into sg, on return offset into the mapped area
3178 * @len: bytes to map, on return number of bytes mapped
3180 * Returns virtual address of the start of the mapped page
3182 void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count,
3183 size_t *offset, size_t *len)
3186 size_t sg_len = 0, len_complete = 0;
3187 struct scatterlist *sg;
3190 WARN_ON(!irqs_disabled());
3192 for_each_sg(sgl, sg, sg_count, i) {
3193 len_complete = sg_len; /* Complete sg-entries */
3194 sg_len += sg->length;
3195 if (sg_len > *offset)
3199 if (unlikely(i == sg_count)) {
3200 printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, "
3202 __func__, sg_len, *offset, sg_count);
3207 /* Offset starting from the beginning of first page in this sg-entry */
3208 *offset = *offset - len_complete + sg->offset;
3210 /* Assumption: contiguous pages can be accessed as "page + i" */
3211 page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT));
3212 *offset &= ~PAGE_MASK;
3214 /* Bytes in this sg-entry from *offset to the end of the page */
3215 sg_len = PAGE_SIZE - *offset;
3219 return kmap_atomic(page);
3221 EXPORT_SYMBOL(scsi_kmap_atomic_sg);
3224 * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg
3225 * @virt: virtual address to be unmapped
3227 void scsi_kunmap_atomic_sg(void *virt)
3229 kunmap_atomic(virt);
3231 EXPORT_SYMBOL(scsi_kunmap_atomic_sg);
3233 void sdev_disable_disk_events(struct scsi_device *sdev)
3235 atomic_inc(&sdev->disk_events_disable_depth);
3237 EXPORT_SYMBOL(sdev_disable_disk_events);
3239 void sdev_enable_disk_events(struct scsi_device *sdev)
3241 if (WARN_ON_ONCE(atomic_read(&sdev->disk_events_disable_depth) <= 0))
3243 atomic_dec(&sdev->disk_events_disable_depth);
3245 EXPORT_SYMBOL(sdev_enable_disk_events);
3248 * scsi_vpd_lun_id - return a unique device identification
3249 * @sdev: SCSI device
3250 * @id: buffer for the identification
3251 * @id_len: length of the buffer
3253 * Copies a unique device identification into @id based
3254 * on the information in the VPD page 0x83 of the device.
3255 * The string will be formatted as a SCSI name string.
3257 * Returns the length of the identification or error on failure.
3258 * If the identifier is longer than the supplied buffer the actual
3259 * identifier length is returned and the buffer is not zero-padded.
3261 int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len)
3263 u8 cur_id_type = 0xff;
3265 unsigned char *d, *cur_id_str;
3266 unsigned char __rcu *vpd_pg83;
3267 int id_size = -EINVAL;
3270 vpd_pg83 = rcu_dereference(sdev->vpd_pg83);
3277 * Look for the correct descriptor.
3278 * Order of preference for lun descriptor:
3279 * - SCSI name string
3280 * - NAA IEEE Registered Extended
3281 * - EUI-64 based 16-byte
3282 * - EUI-64 based 12-byte
3283 * - NAA IEEE Registered
3284 * - NAA IEEE Extended
3286 * as longer descriptors reduce the likelyhood
3287 * of identification clashes.
3290 /* The id string must be at least 20 bytes + terminating NULL byte */
3296 memset(id, 0, id_len);
3298 while (d < vpd_pg83 + sdev->vpd_pg83_len) {
3299 /* Skip designators not referring to the LUN */
3300 if ((d[1] & 0x30) != 0x00)
3303 switch (d[1] & 0xf) {
3306 if (cur_id_size > d[3])
3308 /* Prefer anything */
3309 if (cur_id_type > 0x01 && cur_id_type != 0xff)
3312 if (cur_id_size + 4 > id_len)
3313 cur_id_size = id_len - 4;
3315 cur_id_type = d[1] & 0xf;
3316 id_size = snprintf(id, id_len, "t10.%*pE",
3317 cur_id_size, cur_id_str);
3321 if (cur_id_size > d[3])
3323 /* Prefer NAA IEEE Registered Extended */
3324 if (cur_id_type == 0x3 &&
3325 cur_id_size == d[3])
3329 cur_id_type = d[1] & 0xf;
3330 switch (cur_id_size) {
3332 id_size = snprintf(id, id_len,
3337 id_size = snprintf(id, id_len,
3342 id_size = snprintf(id, id_len,
3353 if (cur_id_size > d[3])
3357 cur_id_type = d[1] & 0xf;
3358 switch (cur_id_size) {
3360 id_size = snprintf(id, id_len,
3365 id_size = snprintf(id, id_len,
3375 /* SCSI name string */
3376 if (cur_id_size + 4 > d[3])
3378 /* Prefer others for truncated descriptor */
3379 if (cur_id_size && d[3] > id_len)
3381 cur_id_size = id_size = d[3];
3383 cur_id_type = d[1] & 0xf;
3384 if (cur_id_size >= id_len)
3385 cur_id_size = id_len - 1;
3386 memcpy(id, cur_id_str, cur_id_size);
3387 /* Decrease priority for truncated descriptor */
3388 if (cur_id_size != id_size)
3401 EXPORT_SYMBOL(scsi_vpd_lun_id);
3404 * scsi_vpd_tpg_id - return a target port group identifier
3405 * @sdev: SCSI device
3407 * Returns the Target Port Group identifier from the information
3408 * froom VPD page 0x83 of the device.
3410 * Returns the identifier or error on failure.
3412 int scsi_vpd_tpg_id(struct scsi_device *sdev, int *rel_id)
3415 unsigned char __rcu *vpd_pg83;
3416 int group_id = -EAGAIN, rel_port = -1;
3419 vpd_pg83 = rcu_dereference(sdev->vpd_pg83);
3425 d = sdev->vpd_pg83 + 4;
3426 while (d < sdev->vpd_pg83 + sdev->vpd_pg83_len) {
3427 switch (d[1] & 0xf) {
3429 /* Relative target port */
3430 rel_port = get_unaligned_be16(&d[6]);
3433 /* Target port group */
3434 group_id = get_unaligned_be16(&d[6]);
3443 if (group_id >= 0 && rel_id && rel_port != -1)
3448 EXPORT_SYMBOL(scsi_vpd_tpg_id);