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);
254 if (bufflen && blk_rq_map_kern(sdev->request_queue, req,
255 buffer, bufflen, __GFP_RECLAIM))
258 rq->cmd_len = COMMAND_SIZE(cmd[0]);
259 memcpy(rq->cmd, cmd, rq->cmd_len);
260 rq->retries = retries;
261 req->timeout = timeout;
262 req->cmd_flags |= flags;
263 req->rq_flags |= rq_flags | RQF_QUIET | RQF_PREEMPT;
266 * head injection *required* here otherwise quiesce won't work
268 blk_execute_rq(req->q, NULL, req, 1);
271 * Some devices (USB mass-storage in particular) may transfer
272 * garbage data together with a residue indicating that the data
273 * is invalid. Prevent the garbage from being misinterpreted
274 * and prevent security leaks by zeroing out the excess data.
276 if (unlikely(rq->resid_len > 0 && rq->resid_len <= bufflen))
277 memset(buffer + (bufflen - rq->resid_len), 0, rq->resid_len);
280 *resid = rq->resid_len;
281 if (sense && rq->sense_len)
282 memcpy(sense, rq->sense, SCSI_SENSE_BUFFERSIZE);
284 scsi_normalize_sense(rq->sense, rq->sense_len, sshdr);
287 blk_put_request(req);
291 EXPORT_SYMBOL(scsi_execute);
294 * Function: scsi_init_cmd_errh()
296 * Purpose: Initialize cmd fields related to error handling.
298 * Arguments: cmd - command that is ready to be queued.
300 * Notes: This function has the job of initializing a number of
301 * fields related to error handling. Typically this will
302 * be called once for each command, as required.
304 static void scsi_init_cmd_errh(struct scsi_cmnd *cmd)
306 cmd->serial_number = 0;
307 scsi_set_resid(cmd, 0);
308 memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
309 if (cmd->cmd_len == 0)
310 cmd->cmd_len = scsi_command_size(cmd->cmnd);
313 void scsi_device_unbusy(struct scsi_device *sdev)
315 struct Scsi_Host *shost = sdev->host;
316 struct scsi_target *starget = scsi_target(sdev);
319 atomic_dec(&shost->host_busy);
320 if (starget->can_queue > 0)
321 atomic_dec(&starget->target_busy);
323 if (unlikely(scsi_host_in_recovery(shost) &&
324 (shost->host_failed || shost->host_eh_scheduled))) {
325 spin_lock_irqsave(shost->host_lock, flags);
326 scsi_eh_wakeup(shost);
327 spin_unlock_irqrestore(shost->host_lock, flags);
330 atomic_dec(&sdev->device_busy);
333 static void scsi_kick_queue(struct request_queue *q)
336 blk_mq_start_hw_queues(q);
342 * Called for single_lun devices on IO completion. Clear starget_sdev_user,
343 * and call blk_run_queue for all the scsi_devices on the target -
344 * including current_sdev first.
346 * Called with *no* scsi locks held.
348 static void scsi_single_lun_run(struct scsi_device *current_sdev)
350 struct Scsi_Host *shost = current_sdev->host;
351 struct scsi_device *sdev, *tmp;
352 struct scsi_target *starget = scsi_target(current_sdev);
355 spin_lock_irqsave(shost->host_lock, flags);
356 starget->starget_sdev_user = NULL;
357 spin_unlock_irqrestore(shost->host_lock, flags);
360 * Call blk_run_queue for all LUNs on the target, starting with
361 * current_sdev. We race with others (to set starget_sdev_user),
362 * but in most cases, we will be first. Ideally, each LU on the
363 * target would get some limited time or requests on the target.
365 scsi_kick_queue(current_sdev->request_queue);
367 spin_lock_irqsave(shost->host_lock, flags);
368 if (starget->starget_sdev_user)
370 list_for_each_entry_safe(sdev, tmp, &starget->devices,
371 same_target_siblings) {
372 if (sdev == current_sdev)
374 if (scsi_device_get(sdev))
377 spin_unlock_irqrestore(shost->host_lock, flags);
378 scsi_kick_queue(sdev->request_queue);
379 spin_lock_irqsave(shost->host_lock, flags);
381 scsi_device_put(sdev);
384 spin_unlock_irqrestore(shost->host_lock, flags);
387 static inline bool scsi_device_is_busy(struct scsi_device *sdev)
389 if (atomic_read(&sdev->device_busy) >= sdev->queue_depth)
391 if (atomic_read(&sdev->device_blocked) > 0)
396 static inline bool scsi_target_is_busy(struct scsi_target *starget)
398 if (starget->can_queue > 0) {
399 if (atomic_read(&starget->target_busy) >= starget->can_queue)
401 if (atomic_read(&starget->target_blocked) > 0)
407 static inline bool scsi_host_is_busy(struct Scsi_Host *shost)
409 if (shost->can_queue > 0 &&
410 atomic_read(&shost->host_busy) >= shost->can_queue)
412 if (atomic_read(&shost->host_blocked) > 0)
414 if (shost->host_self_blocked)
419 static void scsi_starved_list_run(struct Scsi_Host *shost)
421 LIST_HEAD(starved_list);
422 struct scsi_device *sdev;
425 spin_lock_irqsave(shost->host_lock, flags);
426 list_splice_init(&shost->starved_list, &starved_list);
428 while (!list_empty(&starved_list)) {
429 struct request_queue *slq;
432 * As long as shost is accepting commands and we have
433 * starved queues, call blk_run_queue. scsi_request_fn
434 * drops the queue_lock and can add us back to the
437 * host_lock protects the starved_list and starved_entry.
438 * scsi_request_fn must get the host_lock before checking
439 * or modifying starved_list or starved_entry.
441 if (scsi_host_is_busy(shost))
444 sdev = list_entry(starved_list.next,
445 struct scsi_device, starved_entry);
446 list_del_init(&sdev->starved_entry);
447 if (scsi_target_is_busy(scsi_target(sdev))) {
448 list_move_tail(&sdev->starved_entry,
449 &shost->starved_list);
454 * Once we drop the host lock, a racing scsi_remove_device()
455 * call may remove the sdev from the starved list and destroy
456 * it and the queue. Mitigate by taking a reference to the
457 * queue and never touching the sdev again after we drop the
458 * host lock. Note: if __scsi_remove_device() invokes
459 * blk_cleanup_queue() before the queue is run from this
460 * function then blk_run_queue() will return immediately since
461 * blk_cleanup_queue() marks the queue with QUEUE_FLAG_DYING.
463 slq = sdev->request_queue;
464 if (!blk_get_queue(slq))
466 spin_unlock_irqrestore(shost->host_lock, flags);
468 scsi_kick_queue(slq);
471 spin_lock_irqsave(shost->host_lock, flags);
473 /* put any unprocessed entries back */
474 list_splice(&starved_list, &shost->starved_list);
475 spin_unlock_irqrestore(shost->host_lock, flags);
479 * Function: scsi_run_queue()
481 * Purpose: Select a proper request queue to serve next
483 * Arguments: q - last request's queue
487 * Notes: The previous command was completely finished, start
488 * a new one if possible.
490 static void scsi_run_queue(struct request_queue *q)
492 struct scsi_device *sdev = q->queuedata;
494 if (scsi_target(sdev)->single_lun)
495 scsi_single_lun_run(sdev);
496 if (!list_empty(&sdev->host->starved_list))
497 scsi_starved_list_run(sdev->host);
500 blk_mq_run_hw_queues(q, false);
505 void scsi_requeue_run_queue(struct work_struct *work)
507 struct scsi_device *sdev;
508 struct request_queue *q;
510 sdev = container_of(work, struct scsi_device, requeue_work);
511 q = sdev->request_queue;
516 * Function: scsi_requeue_command()
518 * Purpose: Handle post-processing of completed commands.
520 * Arguments: q - queue to operate on
521 * cmd - command that may need to be requeued.
525 * Notes: After command completion, there may be blocks left
526 * over which weren't finished by the previous command
527 * this can be for a number of reasons - the main one is
528 * I/O errors in the middle of the request, in which case
529 * we need to request the blocks that come after the bad
531 * Notes: Upon return, cmd is a stale pointer.
533 static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd)
535 struct scsi_device *sdev = cmd->device;
536 struct request *req = cmd->request;
539 spin_lock_irqsave(q->queue_lock, flags);
540 blk_unprep_request(req);
542 scsi_put_command(cmd);
543 blk_requeue_request(q, req);
544 spin_unlock_irqrestore(q->queue_lock, flags);
548 put_device(&sdev->sdev_gendev);
551 void scsi_run_host_queues(struct Scsi_Host *shost)
553 struct scsi_device *sdev;
555 shost_for_each_device(sdev, shost)
556 scsi_run_queue(sdev->request_queue);
559 static void scsi_uninit_cmd(struct scsi_cmnd *cmd)
561 if (!blk_rq_is_passthrough(cmd->request)) {
562 struct scsi_driver *drv = scsi_cmd_to_driver(cmd);
564 if (drv->uninit_command)
565 drv->uninit_command(cmd);
569 static void scsi_mq_free_sgtables(struct scsi_cmnd *cmd)
571 struct scsi_data_buffer *sdb;
573 if (cmd->sdb.table.nents)
574 sg_free_table_chained(&cmd->sdb.table, true);
575 if (cmd->request->next_rq) {
576 sdb = cmd->request->next_rq->special;
578 sg_free_table_chained(&sdb->table, true);
580 if (scsi_prot_sg_count(cmd))
581 sg_free_table_chained(&cmd->prot_sdb->table, true);
584 static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd)
586 scsi_mq_free_sgtables(cmd);
587 scsi_uninit_cmd(cmd);
588 scsi_del_cmd_from_list(cmd);
592 * Function: scsi_release_buffers()
594 * Purpose: Free resources allocate for a scsi_command.
596 * Arguments: cmd - command that we are bailing.
598 * Lock status: Assumed that no lock is held upon entry.
602 * Notes: In the event that an upper level driver rejects a
603 * command, we must release resources allocated during
604 * the __init_io() function. Primarily this would involve
605 * the scatter-gather table.
607 static void scsi_release_buffers(struct scsi_cmnd *cmd)
609 if (cmd->sdb.table.nents)
610 sg_free_table_chained(&cmd->sdb.table, false);
612 memset(&cmd->sdb, 0, sizeof(cmd->sdb));
614 if (scsi_prot_sg_count(cmd))
615 sg_free_table_chained(&cmd->prot_sdb->table, false);
618 static void scsi_release_bidi_buffers(struct scsi_cmnd *cmd)
620 struct scsi_data_buffer *bidi_sdb = cmd->request->next_rq->special;
622 sg_free_table_chained(&bidi_sdb->table, false);
623 kmem_cache_free(scsi_sdb_cache, bidi_sdb);
624 cmd->request->next_rq->special = NULL;
627 static bool scsi_end_request(struct request *req, blk_status_t error,
628 unsigned int bytes, unsigned int bidi_bytes)
630 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
631 struct scsi_device *sdev = cmd->device;
632 struct request_queue *q = sdev->request_queue;
634 if (blk_update_request(req, error, bytes))
637 /* Bidi request must be completed as a whole */
638 if (unlikely(bidi_bytes) &&
639 blk_update_request(req->next_rq, error, bidi_bytes))
642 if (blk_queue_add_random(q))
643 add_disk_randomness(req->rq_disk);
647 * In the MQ case the command gets freed by __blk_mq_end_request,
648 * so we have to do all cleanup that depends on it earlier.
650 * We also can't kick the queues from irq context, so we
651 * will have to defer it to a workqueue.
653 scsi_mq_uninit_cmd(cmd);
655 __blk_mq_end_request(req, error);
657 if (scsi_target(sdev)->single_lun ||
658 !list_empty(&sdev->host->starved_list))
659 kblockd_schedule_work(&sdev->requeue_work);
661 blk_mq_run_hw_queues(q, true);
666 scsi_release_bidi_buffers(cmd);
667 scsi_release_buffers(cmd);
668 scsi_put_command(cmd);
670 spin_lock_irqsave(q->queue_lock, flags);
671 blk_finish_request(req, error);
672 spin_unlock_irqrestore(q->queue_lock, flags);
677 put_device(&sdev->sdev_gendev);
682 * __scsi_error_from_host_byte - translate SCSI error code into errno
683 * @cmd: SCSI command (unused)
684 * @result: scsi error code
686 * Translate SCSI error code into block errors.
688 static blk_status_t __scsi_error_from_host_byte(struct scsi_cmnd *cmd,
691 switch (host_byte(result)) {
692 case DID_TRANSPORT_FAILFAST:
693 return BLK_STS_TRANSPORT;
694 case DID_TARGET_FAILURE:
695 set_host_byte(cmd, DID_OK);
696 return BLK_STS_TARGET;
697 case DID_NEXUS_FAILURE:
698 return BLK_STS_NEXUS;
699 case DID_ALLOC_FAILURE:
700 set_host_byte(cmd, DID_OK);
701 return BLK_STS_NOSPC;
702 case DID_MEDIUM_ERROR:
703 set_host_byte(cmd, DID_OK);
704 return BLK_STS_MEDIUM;
706 return BLK_STS_IOERR;
711 * Function: scsi_io_completion()
713 * Purpose: Completion processing for block device I/O requests.
715 * Arguments: cmd - command that is finished.
717 * Lock status: Assumed that no lock is held upon entry.
721 * Notes: We will finish off the specified number of sectors. If we
722 * are done, the command block will be released and the queue
723 * function will be goosed. If we are not done then we have to
724 * figure out what to do next:
726 * a) We can call scsi_requeue_command(). The request
727 * will be unprepared and put back on the queue. Then
728 * a new command will be created for it. This should
729 * be used if we made forward progress, or if we want
730 * to switch from READ(10) to READ(6) for example.
732 * b) We can call __scsi_queue_insert(). The request will
733 * be put back on the queue and retried using the same
734 * command as before, possibly after a delay.
736 * c) We can call scsi_end_request() with -EIO to fail
737 * the remainder of the request.
739 void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
741 int result = cmd->result;
742 struct request_queue *q = cmd->device->request_queue;
743 struct request *req = cmd->request;
744 blk_status_t error = BLK_STS_OK;
745 struct scsi_sense_hdr sshdr;
746 bool sense_valid = false;
747 int sense_deferred = 0, level = 0;
748 enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY,
749 ACTION_DELAYED_RETRY} action;
750 unsigned long wait_for = (cmd->allowed + 1) * req->timeout;
753 sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
755 sense_deferred = scsi_sense_is_deferred(&sshdr);
758 if (blk_rq_is_passthrough(req)) {
762 * SG_IO wants current and deferred errors
764 scsi_req(req)->sense_len =
765 min(8 + cmd->sense_buffer[7],
766 SCSI_SENSE_BUFFERSIZE);
769 error = __scsi_error_from_host_byte(cmd, result);
772 * __scsi_error_from_host_byte may have reset the host_byte
774 scsi_req(req)->result = cmd->result;
775 scsi_req(req)->resid_len = scsi_get_resid(cmd);
777 if (scsi_bidi_cmnd(cmd)) {
779 * Bidi commands Must be complete as a whole,
780 * both sides at once.
782 scsi_req(req->next_rq)->resid_len = scsi_in(cmd)->resid;
783 if (scsi_end_request(req, BLK_STS_OK, blk_rq_bytes(req),
784 blk_rq_bytes(req->next_rq)))
788 } else if (blk_rq_bytes(req) == 0 && result && !sense_deferred) {
790 * Flush commands do not transfers any data, and thus cannot use
791 * good_bytes != blk_rq_bytes(req) as the signal for an error.
792 * This sets the error explicitly for the problem case.
794 error = __scsi_error_from_host_byte(cmd, result);
797 /* no bidi support for !blk_rq_is_passthrough yet */
798 BUG_ON(blk_bidi_rq(req));
801 * Next deal with any sectors which we were able to correctly
804 SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, cmd,
805 "%u sectors total, %d bytes done.\n",
806 blk_rq_sectors(req), good_bytes));
809 * Recovered errors need reporting, but they're always treated as
810 * success, so fiddle the result code here. For passthrough requests
811 * we already took a copy of the original into sreq->result which
812 * is what gets returned to the user
814 if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) {
815 /* if ATA PASS-THROUGH INFORMATION AVAILABLE skip
816 * print since caller wants ATA registers. Only occurs on
817 * SCSI ATA PASS_THROUGH commands when CK_COND=1
819 if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d))
821 else if (!(req->rq_flags & RQF_QUIET))
822 scsi_print_sense(cmd);
824 /* for passthrough error may be set */
829 * special case: failed zero length commands always need to
830 * drop down into the retry code. Otherwise, if we finished
831 * all bytes in the request we are done now.
833 if (!(blk_rq_bytes(req) == 0 && error) &&
834 !scsi_end_request(req, error, good_bytes, 0))
838 * Kill remainder if no retrys.
840 if (error && scsi_noretry_cmd(cmd)) {
841 if (scsi_end_request(req, error, blk_rq_bytes(req), 0))
847 * If there had been no error, but we have leftover bytes in the
848 * requeues just queue the command up again.
853 error = __scsi_error_from_host_byte(cmd, result);
855 if (host_byte(result) == DID_RESET) {
856 /* Third party bus reset or reset for error recovery
857 * reasons. Just retry the command and see what
860 action = ACTION_RETRY;
861 } else if (sense_valid && !sense_deferred) {
862 switch (sshdr.sense_key) {
864 if (cmd->device->removable) {
865 /* Detected disc change. Set a bit
866 * and quietly refuse further access.
868 cmd->device->changed = 1;
869 action = ACTION_FAIL;
871 /* Must have been a power glitch, or a
872 * bus reset. Could not have been a
873 * media change, so we just retry the
874 * command and see what happens.
876 action = ACTION_RETRY;
879 case ILLEGAL_REQUEST:
880 /* If we had an ILLEGAL REQUEST returned, then
881 * we may have performed an unsupported
882 * command. The only thing this should be
883 * would be a ten byte read where only a six
884 * byte read was supported. Also, on a system
885 * where READ CAPACITY failed, we may have
886 * read past the end of the disk.
888 if ((cmd->device->use_10_for_rw &&
889 sshdr.asc == 0x20 && sshdr.ascq == 0x00) &&
890 (cmd->cmnd[0] == READ_10 ||
891 cmd->cmnd[0] == WRITE_10)) {
892 /* This will issue a new 6-byte command. */
893 cmd->device->use_10_for_rw = 0;
894 action = ACTION_REPREP;
895 } else if (sshdr.asc == 0x10) /* DIX */ {
896 action = ACTION_FAIL;
897 error = BLK_STS_PROTECTION;
898 /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */
899 } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) {
900 action = ACTION_FAIL;
901 error = BLK_STS_TARGET;
903 action = ACTION_FAIL;
905 case ABORTED_COMMAND:
906 action = ACTION_FAIL;
907 if (sshdr.asc == 0x10) /* DIF */
908 error = BLK_STS_PROTECTION;
911 /* If the device is in the process of becoming
912 * ready, or has a temporary blockage, retry.
914 if (sshdr.asc == 0x04) {
915 switch (sshdr.ascq) {
916 case 0x01: /* becoming ready */
917 case 0x04: /* format in progress */
918 case 0x05: /* rebuild in progress */
919 case 0x06: /* recalculation in progress */
920 case 0x07: /* operation in progress */
921 case 0x08: /* Long write in progress */
922 case 0x09: /* self test in progress */
923 case 0x14: /* space allocation in progress */
924 action = ACTION_DELAYED_RETRY;
927 action = ACTION_FAIL;
931 action = ACTION_FAIL;
933 case VOLUME_OVERFLOW:
934 /* See SSC3rXX or current. */
935 action = ACTION_FAIL;
938 action = ACTION_FAIL;
942 action = ACTION_FAIL;
944 if (action != ACTION_FAIL &&
945 time_before(cmd->jiffies_at_alloc + wait_for, jiffies))
946 action = ACTION_FAIL;
950 /* Give up and fail the remainder of the request */
951 if (!(req->rq_flags & RQF_QUIET)) {
952 static DEFINE_RATELIMIT_STATE(_rs,
953 DEFAULT_RATELIMIT_INTERVAL,
954 DEFAULT_RATELIMIT_BURST);
956 if (unlikely(scsi_logging_level))
957 level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
958 SCSI_LOG_MLCOMPLETE_BITS);
961 * if logging is enabled the failure will be printed
962 * in scsi_log_completion(), so avoid duplicate messages
964 if (!level && __ratelimit(&_rs)) {
965 scsi_print_result(cmd, NULL, FAILED);
966 if (driver_byte(result) & DRIVER_SENSE)
967 scsi_print_sense(cmd);
968 scsi_print_command(cmd);
971 if (!scsi_end_request(req, error, blk_rq_err_bytes(req), 0))
976 /* Unprep the request and put it back at the head of the queue.
977 * A new command will be prepared and issued.
980 cmd->request->rq_flags &= ~RQF_DONTPREP;
981 scsi_mq_uninit_cmd(cmd);
982 scsi_mq_requeue_cmd(cmd);
984 scsi_release_buffers(cmd);
985 scsi_requeue_command(q, cmd);
989 /* Retry the same command immediately */
990 __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0);
992 case ACTION_DELAYED_RETRY:
993 /* Retry the same command after a delay */
994 __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0);
999 static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb)
1004 * If sg table allocation fails, requeue request later.
1006 if (unlikely(sg_alloc_table_chained(&sdb->table,
1007 blk_rq_nr_phys_segments(req), sdb->table.sgl)))
1008 return BLKPREP_DEFER;
1011 * Next, walk the list, and fill in the addresses and sizes of
1014 count = blk_rq_map_sg(req->q, req, sdb->table.sgl);
1015 BUG_ON(count > sdb->table.nents);
1016 sdb->table.nents = count;
1017 sdb->length = blk_rq_payload_bytes(req);
1022 * Function: scsi_init_io()
1024 * Purpose: SCSI I/O initialize function.
1026 * Arguments: cmd - Command descriptor we wish to initialize
1028 * Returns: 0 on success
1029 * BLKPREP_DEFER if the failure is retryable
1030 * BLKPREP_KILL if the failure is fatal
1032 int scsi_init_io(struct scsi_cmnd *cmd)
1034 struct scsi_device *sdev = cmd->device;
1035 struct request *rq = cmd->request;
1036 bool is_mq = (rq->mq_ctx != NULL);
1037 int error = BLKPREP_KILL;
1039 if (WARN_ON_ONCE(!blk_rq_nr_phys_segments(rq)))
1042 error = scsi_init_sgtable(rq, &cmd->sdb);
1046 if (blk_bidi_rq(rq)) {
1047 if (!rq->q->mq_ops) {
1048 struct scsi_data_buffer *bidi_sdb =
1049 kmem_cache_zalloc(scsi_sdb_cache, GFP_ATOMIC);
1051 error = BLKPREP_DEFER;
1055 rq->next_rq->special = bidi_sdb;
1058 error = scsi_init_sgtable(rq->next_rq, rq->next_rq->special);
1063 if (blk_integrity_rq(rq)) {
1064 struct scsi_data_buffer *prot_sdb = cmd->prot_sdb;
1067 if (prot_sdb == NULL) {
1069 * This can happen if someone (e.g. multipath)
1070 * queues a command to a device on an adapter
1071 * that does not support DIX.
1074 error = BLKPREP_KILL;
1078 ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio);
1080 if (sg_alloc_table_chained(&prot_sdb->table, ivecs,
1081 prot_sdb->table.sgl)) {
1082 error = BLKPREP_DEFER;
1086 count = blk_rq_map_integrity_sg(rq->q, rq->bio,
1087 prot_sdb->table.sgl);
1088 BUG_ON(unlikely(count > ivecs));
1089 BUG_ON(unlikely(count > queue_max_integrity_segments(rq->q)));
1091 cmd->prot_sdb = prot_sdb;
1092 cmd->prot_sdb->table.nents = count;
1098 scsi_mq_free_sgtables(cmd);
1100 scsi_release_buffers(cmd);
1101 cmd->request->special = NULL;
1102 scsi_put_command(cmd);
1103 put_device(&sdev->sdev_gendev);
1107 EXPORT_SYMBOL(scsi_init_io);
1110 * scsi_initialize_rq - initialize struct scsi_cmnd.req
1111 * @rq: Request associated with the SCSI command to be initialized.
1113 * Called from inside blk_get_request().
1115 void scsi_initialize_rq(struct request *rq)
1117 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
1119 scsi_req_init(&cmd->req);
1121 EXPORT_SYMBOL(scsi_initialize_rq);
1123 /* Add a command to the list used by the aacraid and dpt_i2o drivers */
1124 void scsi_add_cmd_to_list(struct scsi_cmnd *cmd)
1126 struct scsi_device *sdev = cmd->device;
1127 struct Scsi_Host *shost = sdev->host;
1128 unsigned long flags;
1130 if (shost->use_cmd_list) {
1131 spin_lock_irqsave(&sdev->list_lock, flags);
1132 list_add_tail(&cmd->list, &sdev->cmd_list);
1133 spin_unlock_irqrestore(&sdev->list_lock, flags);
1137 /* Remove a command from the list used by the aacraid and dpt_i2o drivers */
1138 void scsi_del_cmd_from_list(struct scsi_cmnd *cmd)
1140 struct scsi_device *sdev = cmd->device;
1141 struct Scsi_Host *shost = sdev->host;
1142 unsigned long flags;
1144 if (shost->use_cmd_list) {
1145 spin_lock_irqsave(&sdev->list_lock, flags);
1146 BUG_ON(list_empty(&cmd->list));
1147 list_del_init(&cmd->list);
1148 spin_unlock_irqrestore(&sdev->list_lock, flags);
1152 /* Called after a request has been started. */
1153 void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
1155 void *buf = cmd->sense_buffer;
1156 void *prot = cmd->prot_sdb;
1157 unsigned int unchecked_isa_dma = cmd->flags & SCMD_UNCHECKED_ISA_DMA;
1159 /* zero out the cmd, except for the embedded scsi_request */
1160 memset((char *)cmd + sizeof(cmd->req), 0,
1161 sizeof(*cmd) - sizeof(cmd->req) + dev->host->hostt->cmd_size);
1164 cmd->sense_buffer = buf;
1165 cmd->prot_sdb = prot;
1166 cmd->flags = unchecked_isa_dma;
1167 INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
1168 cmd->jiffies_at_alloc = jiffies;
1170 scsi_add_cmd_to_list(cmd);
1173 static int scsi_setup_scsi_cmnd(struct scsi_device *sdev, struct request *req)
1175 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
1178 * Passthrough requests may transfer data, in which case they must
1179 * a bio attached to them. Or they might contain a SCSI command
1180 * that does not transfer data, in which case they may optionally
1181 * submit a request without an attached bio.
1184 int ret = scsi_init_io(cmd);
1188 BUG_ON(blk_rq_bytes(req));
1190 memset(&cmd->sdb, 0, sizeof(cmd->sdb));
1193 cmd->cmd_len = scsi_req(req)->cmd_len;
1194 cmd->cmnd = scsi_req(req)->cmd;
1195 cmd->transfersize = blk_rq_bytes(req);
1196 cmd->allowed = scsi_req(req)->retries;
1201 * Setup a normal block command. These are simple request from filesystems
1202 * that still need to be translated to SCSI CDBs from the ULD.
1204 static int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
1206 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
1208 if (unlikely(sdev->handler && sdev->handler->prep_fn)) {
1209 int ret = sdev->handler->prep_fn(sdev, req);
1210 if (ret != BLKPREP_OK)
1214 cmd->cmnd = scsi_req(req)->cmd = scsi_req(req)->__cmd;
1215 memset(cmd->cmnd, 0, BLK_MAX_CDB);
1216 return scsi_cmd_to_driver(cmd)->init_command(cmd);
1219 static int scsi_setup_cmnd(struct scsi_device *sdev, struct request *req)
1221 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
1223 if (!blk_rq_bytes(req))
1224 cmd->sc_data_direction = DMA_NONE;
1225 else if (rq_data_dir(req) == WRITE)
1226 cmd->sc_data_direction = DMA_TO_DEVICE;
1228 cmd->sc_data_direction = DMA_FROM_DEVICE;
1230 if (blk_rq_is_scsi(req))
1231 return scsi_setup_scsi_cmnd(sdev, req);
1233 return scsi_setup_fs_cmnd(sdev, req);
1237 scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
1239 int ret = BLKPREP_OK;
1242 * If the device is not in running state we will reject some
1245 if (unlikely(sdev->sdev_state != SDEV_RUNNING)) {
1246 switch (sdev->sdev_state) {
1248 case SDEV_TRANSPORT_OFFLINE:
1250 * If the device is offline we refuse to process any
1251 * commands. The device must be brought online
1252 * before trying any recovery commands.
1254 sdev_printk(KERN_ERR, sdev,
1255 "rejecting I/O to offline device\n");
1260 * If the device is fully deleted, we refuse to
1261 * process any commands as well.
1263 sdev_printk(KERN_ERR, sdev,
1264 "rejecting I/O to dead device\n");
1268 case SDEV_CREATED_BLOCK:
1269 ret = BLKPREP_DEFER;
1273 * If the devices is blocked we defer normal commands.
1275 if (!(req->rq_flags & RQF_PREEMPT))
1276 ret = BLKPREP_DEFER;
1280 * For any other not fully online state we only allow
1281 * special commands. In particular any user initiated
1282 * command is not allowed.
1284 if (!(req->rq_flags & RQF_PREEMPT))
1293 scsi_prep_return(struct request_queue *q, struct request *req, int ret)
1295 struct scsi_device *sdev = q->queuedata;
1299 case BLKPREP_INVALID:
1300 scsi_req(req)->result = DID_NO_CONNECT << 16;
1301 /* release the command and kill it */
1303 struct scsi_cmnd *cmd = req->special;
1304 scsi_release_buffers(cmd);
1305 scsi_put_command(cmd);
1306 put_device(&sdev->sdev_gendev);
1307 req->special = NULL;
1312 * If we defer, the blk_peek_request() returns NULL, but the
1313 * queue must be restarted, so we schedule a callback to happen
1316 if (atomic_read(&sdev->device_busy) == 0)
1317 blk_delay_queue(q, SCSI_QUEUE_DELAY);
1320 req->rq_flags |= RQF_DONTPREP;
1326 static int scsi_prep_fn(struct request_queue *q, struct request *req)
1328 struct scsi_device *sdev = q->queuedata;
1329 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
1332 ret = scsi_prep_state_check(sdev, req);
1333 if (ret != BLKPREP_OK)
1336 if (!req->special) {
1337 /* Bail if we can't get a reference to the device */
1338 if (unlikely(!get_device(&sdev->sdev_gendev))) {
1339 ret = BLKPREP_DEFER;
1343 scsi_init_command(sdev, cmd);
1347 cmd->tag = req->tag;
1349 cmd->prot_op = SCSI_PROT_NORMAL;
1351 ret = scsi_setup_cmnd(sdev, req);
1353 return scsi_prep_return(q, req, ret);
1356 static void scsi_unprep_fn(struct request_queue *q, struct request *req)
1358 scsi_uninit_cmd(blk_mq_rq_to_pdu(req));
1362 * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else
1365 * Called with the queue_lock held.
1367 static inline int scsi_dev_queue_ready(struct request_queue *q,
1368 struct scsi_device *sdev)
1372 busy = atomic_inc_return(&sdev->device_busy) - 1;
1373 if (atomic_read(&sdev->device_blocked)) {
1378 * unblock after device_blocked iterates to zero
1380 if (atomic_dec_return(&sdev->device_blocked) > 0) {
1382 * For the MQ case we take care of this in the caller.
1385 blk_delay_queue(q, SCSI_QUEUE_DELAY);
1388 SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev,
1389 "unblocking device at zero depth\n"));
1392 if (busy >= sdev->queue_depth)
1397 atomic_dec(&sdev->device_busy);
1402 * scsi_target_queue_ready: checks if there we can send commands to target
1403 * @sdev: scsi device on starget to check.
1405 static inline int scsi_target_queue_ready(struct Scsi_Host *shost,
1406 struct scsi_device *sdev)
1408 struct scsi_target *starget = scsi_target(sdev);
1411 if (starget->single_lun) {
1412 spin_lock_irq(shost->host_lock);
1413 if (starget->starget_sdev_user &&
1414 starget->starget_sdev_user != sdev) {
1415 spin_unlock_irq(shost->host_lock);
1418 starget->starget_sdev_user = sdev;
1419 spin_unlock_irq(shost->host_lock);
1422 if (starget->can_queue <= 0)
1425 busy = atomic_inc_return(&starget->target_busy) - 1;
1426 if (atomic_read(&starget->target_blocked) > 0) {
1431 * unblock after target_blocked iterates to zero
1433 if (atomic_dec_return(&starget->target_blocked) > 0)
1436 SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget,
1437 "unblocking target at zero depth\n"));
1440 if (busy >= starget->can_queue)
1446 spin_lock_irq(shost->host_lock);
1447 list_move_tail(&sdev->starved_entry, &shost->starved_list);
1448 spin_unlock_irq(shost->host_lock);
1450 if (starget->can_queue > 0)
1451 atomic_dec(&starget->target_busy);
1456 * scsi_host_queue_ready: if we can send requests to shost, return 1 else
1457 * return 0. We must end up running the queue again whenever 0 is
1458 * returned, else IO can hang.
1460 static inline int scsi_host_queue_ready(struct request_queue *q,
1461 struct Scsi_Host *shost,
1462 struct scsi_device *sdev)
1466 if (scsi_host_in_recovery(shost))
1469 busy = atomic_inc_return(&shost->host_busy) - 1;
1470 if (atomic_read(&shost->host_blocked) > 0) {
1475 * unblock after host_blocked iterates to zero
1477 if (atomic_dec_return(&shost->host_blocked) > 0)
1481 shost_printk(KERN_INFO, shost,
1482 "unblocking host at zero depth\n"));
1485 if (shost->can_queue > 0 && busy >= shost->can_queue)
1487 if (shost->host_self_blocked)
1490 /* We're OK to process the command, so we can't be starved */
1491 if (!list_empty(&sdev->starved_entry)) {
1492 spin_lock_irq(shost->host_lock);
1493 if (!list_empty(&sdev->starved_entry))
1494 list_del_init(&sdev->starved_entry);
1495 spin_unlock_irq(shost->host_lock);
1501 spin_lock_irq(shost->host_lock);
1502 if (list_empty(&sdev->starved_entry))
1503 list_add_tail(&sdev->starved_entry, &shost->starved_list);
1504 spin_unlock_irq(shost->host_lock);
1506 atomic_dec(&shost->host_busy);
1511 * Busy state exporting function for request stacking drivers.
1513 * For efficiency, no lock is taken to check the busy state of
1514 * shost/starget/sdev, since the returned value is not guaranteed and
1515 * may be changed after request stacking drivers call the function,
1516 * regardless of taking lock or not.
1518 * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi
1519 * needs to return 'not busy'. Otherwise, request stacking drivers
1520 * may hold requests forever.
1522 static int scsi_lld_busy(struct request_queue *q)
1524 struct scsi_device *sdev = q->queuedata;
1525 struct Scsi_Host *shost;
1527 if (blk_queue_dying(q))
1533 * Ignore host/starget busy state.
1534 * Since block layer does not have a concept of fairness across
1535 * multiple queues, congestion of host/starget needs to be handled
1538 if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev))
1545 * Kill a request for a dead device
1547 static void scsi_kill_request(struct request *req, struct request_queue *q)
1549 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
1550 struct scsi_device *sdev;
1551 struct scsi_target *starget;
1552 struct Scsi_Host *shost;
1554 blk_start_request(req);
1556 scmd_printk(KERN_INFO, cmd, "killing request\n");
1559 starget = scsi_target(sdev);
1561 scsi_init_cmd_errh(cmd);
1562 cmd->result = DID_NO_CONNECT << 16;
1563 atomic_inc(&cmd->device->iorequest_cnt);
1566 * SCSI request completion path will do scsi_device_unbusy(),
1567 * bump busy counts. To bump the counters, we need to dance
1568 * with the locks as normal issue path does.
1570 atomic_inc(&sdev->device_busy);
1571 atomic_inc(&shost->host_busy);
1572 if (starget->can_queue > 0)
1573 atomic_inc(&starget->target_busy);
1575 blk_complete_request(req);
1578 static void scsi_softirq_done(struct request *rq)
1580 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
1581 unsigned long wait_for = (cmd->allowed + 1) * rq->timeout;
1584 INIT_LIST_HEAD(&cmd->eh_entry);
1586 atomic_inc(&cmd->device->iodone_cnt);
1588 atomic_inc(&cmd->device->ioerr_cnt);
1590 disposition = scsi_decide_disposition(cmd);
1591 if (disposition != SUCCESS &&
1592 time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) {
1593 sdev_printk(KERN_ERR, cmd->device,
1594 "timing out command, waited %lus\n",
1596 disposition = SUCCESS;
1599 scsi_log_completion(cmd, disposition);
1601 switch (disposition) {
1603 scsi_finish_command(cmd);
1606 scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY);
1608 case ADD_TO_MLQUEUE:
1609 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
1612 scsi_eh_scmd_add(cmd);
1618 * scsi_dispatch_command - Dispatch a command to the low-level driver.
1619 * @cmd: command block we are dispatching.
1621 * Return: nonzero return request was rejected and device's queue needs to be
1624 static int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
1626 struct Scsi_Host *host = cmd->device->host;
1629 atomic_inc(&cmd->device->iorequest_cnt);
1631 /* check if the device is still usable */
1632 if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
1633 /* in SDEV_DEL we error all commands. DID_NO_CONNECT
1634 * returns an immediate error upwards, and signals
1635 * that the device is no longer present */
1636 cmd->result = DID_NO_CONNECT << 16;
1640 /* Check to see if the scsi lld made this device blocked. */
1641 if (unlikely(scsi_device_blocked(cmd->device))) {
1643 * in blocked state, the command is just put back on
1644 * the device queue. The suspend state has already
1645 * blocked the queue so future requests should not
1646 * occur until the device transitions out of the
1649 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
1650 "queuecommand : device blocked\n"));
1651 return SCSI_MLQUEUE_DEVICE_BUSY;
1654 /* Store the LUN value in cmnd, if needed. */
1655 if (cmd->device->lun_in_cdb)
1656 cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
1657 (cmd->device->lun << 5 & 0xe0);
1662 * Before we queue this command, check if the command
1663 * length exceeds what the host adapter can handle.
1665 if (cmd->cmd_len > cmd->device->host->max_cmd_len) {
1666 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
1667 "queuecommand : command too long. "
1668 "cdb_size=%d host->max_cmd_len=%d\n",
1669 cmd->cmd_len, cmd->device->host->max_cmd_len));
1670 cmd->result = (DID_ABORT << 16);
1674 if (unlikely(host->shost_state == SHOST_DEL)) {
1675 cmd->result = (DID_NO_CONNECT << 16);
1680 trace_scsi_dispatch_cmd_start(cmd);
1681 rtn = host->hostt->queuecommand(host, cmd);
1683 trace_scsi_dispatch_cmd_error(cmd, rtn);
1684 if (rtn != SCSI_MLQUEUE_DEVICE_BUSY &&
1685 rtn != SCSI_MLQUEUE_TARGET_BUSY)
1686 rtn = SCSI_MLQUEUE_HOST_BUSY;
1688 SCSI_LOG_MLQUEUE(3, scmd_printk(KERN_INFO, cmd,
1689 "queuecommand : request rejected\n"));
1694 cmd->scsi_done(cmd);
1699 * scsi_done - Invoke completion on finished SCSI command.
1700 * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives
1701 * ownership back to SCSI Core -- i.e. the LLDD has finished with it.
1703 * Description: This function is the mid-level's (SCSI Core) interrupt routine,
1704 * which regains ownership of the SCSI command (de facto) from a LLDD, and
1705 * calls blk_complete_request() for further processing.
1707 * This function is interrupt context safe.
1709 static void scsi_done(struct scsi_cmnd *cmd)
1711 trace_scsi_dispatch_cmd_done(cmd);
1712 blk_complete_request(cmd->request);
1716 * Function: scsi_request_fn()
1718 * Purpose: Main strategy routine for SCSI.
1720 * Arguments: q - Pointer to actual queue.
1724 * Lock status: IO request lock assumed to be held when called.
1726 static void scsi_request_fn(struct request_queue *q)
1727 __releases(q->queue_lock)
1728 __acquires(q->queue_lock)
1730 struct scsi_device *sdev = q->queuedata;
1731 struct Scsi_Host *shost;
1732 struct scsi_cmnd *cmd;
1733 struct request *req;
1736 * To start with, we keep looping until the queue is empty, or until
1737 * the host is no longer able to accept any more requests.
1743 * get next queueable request. We do this early to make sure
1744 * that the request is fully prepared even if we cannot
1747 req = blk_peek_request(q);
1751 if (unlikely(!scsi_device_online(sdev))) {
1752 sdev_printk(KERN_ERR, sdev,
1753 "rejecting I/O to offline device\n");
1754 scsi_kill_request(req, q);
1758 if (!scsi_dev_queue_ready(q, sdev))
1762 * Remove the request from the request list.
1764 if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req)))
1765 blk_start_request(req);
1767 spin_unlock_irq(q->queue_lock);
1768 cmd = blk_mq_rq_to_pdu(req);
1769 if (cmd != req->special) {
1770 printk(KERN_CRIT "impossible request in %s.\n"
1771 "please mail a stack trace to "
1772 "linux-scsi@vger.kernel.org\n",
1774 blk_dump_rq_flags(req, "foo");
1779 * We hit this when the driver is using a host wide
1780 * tag map. For device level tag maps the queue_depth check
1781 * in the device ready fn would prevent us from trying
1782 * to allocate a tag. Since the map is a shared host resource
1783 * we add the dev to the starved list so it eventually gets
1784 * a run when a tag is freed.
1786 if (blk_queue_tagged(q) && !(req->rq_flags & RQF_QUEUED)) {
1787 spin_lock_irq(shost->host_lock);
1788 if (list_empty(&sdev->starved_entry))
1789 list_add_tail(&sdev->starved_entry,
1790 &shost->starved_list);
1791 spin_unlock_irq(shost->host_lock);
1795 if (!scsi_target_queue_ready(shost, sdev))
1798 if (!scsi_host_queue_ready(q, shost, sdev))
1799 goto host_not_ready;
1801 if (sdev->simple_tags)
1802 cmd->flags |= SCMD_TAGGED;
1804 cmd->flags &= ~SCMD_TAGGED;
1807 * Finally, initialize any error handling parameters, and set up
1808 * the timers for timeouts.
1810 scsi_init_cmd_errh(cmd);
1813 * Dispatch the command to the low-level driver.
1815 cmd->scsi_done = scsi_done;
1816 rtn = scsi_dispatch_cmd(cmd);
1818 scsi_queue_insert(cmd, rtn);
1819 spin_lock_irq(q->queue_lock);
1822 spin_lock_irq(q->queue_lock);
1828 if (scsi_target(sdev)->can_queue > 0)
1829 atomic_dec(&scsi_target(sdev)->target_busy);
1832 * lock q, handle tag, requeue req, and decrement device_busy. We
1833 * must return with queue_lock held.
1835 * Decrementing device_busy without checking it is OK, as all such
1836 * cases (host limits or settings) should run the queue at some
1839 spin_lock_irq(q->queue_lock);
1840 blk_requeue_request(q, req);
1841 atomic_dec(&sdev->device_busy);
1843 if (!atomic_read(&sdev->device_busy) && !scsi_device_blocked(sdev))
1844 blk_delay_queue(q, SCSI_QUEUE_DELAY);
1847 static inline blk_status_t prep_to_mq(int ret)
1853 return BLK_STS_RESOURCE;
1855 return BLK_STS_IOERR;
1859 /* Size in bytes of the sg-list stored in the scsi-mq command-private data. */
1860 static unsigned int scsi_mq_sgl_size(struct Scsi_Host *shost)
1862 return min_t(unsigned int, shost->sg_tablesize, SG_CHUNK_SIZE) *
1863 sizeof(struct scatterlist);
1866 static int scsi_mq_prep_fn(struct request *req)
1868 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
1869 struct scsi_device *sdev = req->q->queuedata;
1870 struct Scsi_Host *shost = sdev->host;
1871 struct scatterlist *sg;
1873 scsi_init_command(sdev, cmd);
1879 cmd->tag = req->tag;
1880 cmd->prot_op = SCSI_PROT_NORMAL;
1882 sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size;
1883 cmd->sdb.table.sgl = sg;
1885 if (scsi_host_get_prot(shost)) {
1886 memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer));
1888 cmd->prot_sdb->table.sgl =
1889 (struct scatterlist *)(cmd->prot_sdb + 1);
1892 if (blk_bidi_rq(req)) {
1893 struct request *next_rq = req->next_rq;
1894 struct scsi_data_buffer *bidi_sdb = blk_mq_rq_to_pdu(next_rq);
1896 memset(bidi_sdb, 0, sizeof(struct scsi_data_buffer));
1897 bidi_sdb->table.sgl =
1898 (struct scatterlist *)(bidi_sdb + 1);
1900 next_rq->special = bidi_sdb;
1903 blk_mq_start_request(req);
1905 return scsi_setup_cmnd(sdev, req);
1908 static void scsi_mq_done(struct scsi_cmnd *cmd)
1910 trace_scsi_dispatch_cmd_done(cmd);
1911 blk_mq_complete_request(cmd->request);
1914 static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
1915 const struct blk_mq_queue_data *bd)
1917 struct request *req = bd->rq;
1918 struct request_queue *q = req->q;
1919 struct scsi_device *sdev = q->queuedata;
1920 struct Scsi_Host *shost = sdev->host;
1921 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
1925 ret = prep_to_mq(scsi_prep_state_check(sdev, req));
1926 if (ret != BLK_STS_OK)
1929 ret = BLK_STS_RESOURCE;
1930 if (!get_device(&sdev->sdev_gendev))
1933 if (!scsi_dev_queue_ready(q, sdev))
1934 goto out_put_device;
1935 if (!scsi_target_queue_ready(shost, sdev))
1936 goto out_dec_device_busy;
1937 if (!scsi_host_queue_ready(q, shost, sdev))
1938 goto out_dec_target_busy;
1940 if (!(req->rq_flags & RQF_DONTPREP)) {
1941 ret = prep_to_mq(scsi_mq_prep_fn(req));
1942 if (ret != BLK_STS_OK)
1943 goto out_dec_host_busy;
1944 req->rq_flags |= RQF_DONTPREP;
1946 blk_mq_start_request(req);
1949 if (sdev->simple_tags)
1950 cmd->flags |= SCMD_TAGGED;
1952 cmd->flags &= ~SCMD_TAGGED;
1954 scsi_init_cmd_errh(cmd);
1955 cmd->scsi_done = scsi_mq_done;
1957 reason = scsi_dispatch_cmd(cmd);
1959 scsi_set_blocked(cmd, reason);
1960 ret = BLK_STS_RESOURCE;
1961 goto out_dec_host_busy;
1967 atomic_dec(&shost->host_busy);
1968 out_dec_target_busy:
1969 if (scsi_target(sdev)->can_queue > 0)
1970 atomic_dec(&scsi_target(sdev)->target_busy);
1971 out_dec_device_busy:
1972 atomic_dec(&sdev->device_busy);
1974 put_device(&sdev->sdev_gendev);
1979 case BLK_STS_RESOURCE:
1980 if (atomic_read(&sdev->device_busy) == 0 &&
1981 !scsi_device_blocked(sdev))
1982 blk_mq_delay_run_hw_queue(hctx, SCSI_QUEUE_DELAY);
1986 * Make sure to release all allocated ressources when
1987 * we hit an error, as we will never see this command
1990 if (req->rq_flags & RQF_DONTPREP)
1991 scsi_mq_uninit_cmd(cmd);
1997 static enum blk_eh_timer_return scsi_timeout(struct request *req,
2001 return BLK_EH_RESET_TIMER;
2002 return scsi_times_out(req);
2005 static int scsi_mq_init_request(struct blk_mq_tag_set *set, struct request *rq,
2006 unsigned int hctx_idx, unsigned int numa_node)
2008 struct Scsi_Host *shost = set->driver_data;
2009 const bool unchecked_isa_dma = shost->unchecked_isa_dma;
2010 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
2011 struct scatterlist *sg;
2013 if (unchecked_isa_dma)
2014 cmd->flags |= SCMD_UNCHECKED_ISA_DMA;
2015 cmd->sense_buffer = scsi_alloc_sense_buffer(unchecked_isa_dma,
2016 GFP_KERNEL, numa_node);
2017 if (!cmd->sense_buffer)
2019 cmd->req.sense = cmd->sense_buffer;
2021 if (scsi_host_get_prot(shost)) {
2022 sg = (void *)cmd + sizeof(struct scsi_cmnd) +
2023 shost->hostt->cmd_size;
2024 cmd->prot_sdb = (void *)sg + scsi_mq_sgl_size(shost);
2030 static void scsi_mq_exit_request(struct blk_mq_tag_set *set, struct request *rq,
2031 unsigned int hctx_idx)
2033 struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
2035 scsi_free_sense_buffer(cmd->flags & SCMD_UNCHECKED_ISA_DMA,
2039 static int scsi_map_queues(struct blk_mq_tag_set *set)
2041 struct Scsi_Host *shost = container_of(set, struct Scsi_Host, tag_set);
2043 if (shost->hostt->map_queues)
2044 return shost->hostt->map_queues(shost);
2045 return blk_mq_map_queues(set);
2048 static u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost)
2050 struct device *host_dev;
2051 u64 bounce_limit = 0xffffffff;
2053 if (shost->unchecked_isa_dma)
2054 return BLK_BOUNCE_ISA;
2056 * Platforms with virtual-DMA translation
2057 * hardware have no practical limit.
2059 if (!PCI_DMA_BUS_IS_PHYS)
2060 return BLK_BOUNCE_ANY;
2062 host_dev = scsi_get_device(shost);
2063 if (host_dev && host_dev->dma_mask)
2064 bounce_limit = (u64)dma_max_pfn(host_dev) << PAGE_SHIFT;
2066 return bounce_limit;
2069 void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q)
2071 struct device *dev = shost->dma_dev;
2073 queue_flag_set_unlocked(QUEUE_FLAG_SCSI_PASSTHROUGH, q);
2076 * this limit is imposed by hardware restrictions
2078 blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize,
2081 if (scsi_host_prot_dma(shost)) {
2082 shost->sg_prot_tablesize =
2083 min_not_zero(shost->sg_prot_tablesize,
2084 (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS);
2085 BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize);
2086 blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize);
2089 blk_queue_max_hw_sectors(q, shost->max_sectors);
2090 blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost));
2091 blk_queue_segment_boundary(q, shost->dma_boundary);
2092 dma_set_seg_boundary(dev, shost->dma_boundary);
2094 blk_queue_max_segment_size(q, dma_get_max_seg_size(dev));
2096 if (!shost->use_clustering)
2097 q->limits.cluster = 0;
2100 * set a reasonable default alignment on word boundaries: the
2101 * host and device may alter it using
2102 * blk_queue_update_dma_alignment() later.
2104 blk_queue_dma_alignment(q, 0x03);
2106 EXPORT_SYMBOL_GPL(__scsi_init_queue);
2108 static int scsi_old_init_rq(struct request_queue *q, struct request *rq,
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_old_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_old_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_old_init_rq;
2161 q->exit_rq_fn = scsi_old_exit_rq;
2162 q->initialize_rq_fn = scsi_initialize_rq;
2164 if (blk_init_allocated_queue(q) < 0) {
2165 blk_cleanup_queue(q);
2169 __scsi_init_queue(shost, q);
2170 blk_queue_prep_rq(q, scsi_prep_fn);
2171 blk_queue_unprep_rq(q, scsi_unprep_fn);
2172 blk_queue_softirq_done(q, scsi_softirq_done);
2173 blk_queue_rq_timed_out(q, scsi_times_out);
2174 blk_queue_lld_busy(q, scsi_lld_busy);
2178 static const struct blk_mq_ops scsi_mq_ops = {
2179 .queue_rq = scsi_queue_rq,
2180 .complete = scsi_softirq_done,
2181 .timeout = scsi_timeout,
2182 #ifdef CONFIG_BLK_DEBUG_FS
2183 .show_rq = scsi_show_rq,
2185 .init_request = scsi_mq_init_request,
2186 .exit_request = scsi_mq_exit_request,
2187 .initialize_rq_fn = scsi_initialize_rq,
2188 .map_queues = scsi_map_queues,
2191 struct request_queue *scsi_mq_alloc_queue(struct scsi_device *sdev)
2193 sdev->request_queue = blk_mq_init_queue(&sdev->host->tag_set);
2194 if (IS_ERR(sdev->request_queue))
2197 sdev->request_queue->queuedata = sdev;
2198 __scsi_init_queue(sdev->host, sdev->request_queue);
2199 return sdev->request_queue;
2202 int scsi_mq_setup_tags(struct Scsi_Host *shost)
2204 unsigned int cmd_size, sgl_size;
2206 sgl_size = scsi_mq_sgl_size(shost);
2207 cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size + sgl_size;
2208 if (scsi_host_get_prot(shost))
2209 cmd_size += sizeof(struct scsi_data_buffer) + sgl_size;
2211 memset(&shost->tag_set, 0, sizeof(shost->tag_set));
2212 shost->tag_set.ops = &scsi_mq_ops;
2213 shost->tag_set.nr_hw_queues = shost->nr_hw_queues ? : 1;
2214 shost->tag_set.queue_depth = shost->can_queue;
2215 shost->tag_set.cmd_size = cmd_size;
2216 shost->tag_set.numa_node = NUMA_NO_NODE;
2217 shost->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
2218 shost->tag_set.flags |=
2219 BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy);
2220 shost->tag_set.driver_data = shost;
2222 return blk_mq_alloc_tag_set(&shost->tag_set);
2225 void scsi_mq_destroy_tags(struct Scsi_Host *shost)
2227 blk_mq_free_tag_set(&shost->tag_set);
2231 * scsi_device_from_queue - return sdev associated with a request_queue
2232 * @q: The request queue to return the sdev from
2234 * Return the sdev associated with a request queue or NULL if the
2235 * request_queue does not reference a SCSI device.
2237 struct scsi_device *scsi_device_from_queue(struct request_queue *q)
2239 struct scsi_device *sdev = NULL;
2242 if (q->mq_ops == &scsi_mq_ops)
2243 sdev = q->queuedata;
2244 } else if (q->request_fn == scsi_request_fn)
2245 sdev = q->queuedata;
2246 if (!sdev || !get_device(&sdev->sdev_gendev))
2251 EXPORT_SYMBOL_GPL(scsi_device_from_queue);
2254 * Function: scsi_block_requests()
2256 * Purpose: Utility function used by low-level drivers to prevent further
2257 * commands from being queued to the device.
2259 * Arguments: shost - Host in question
2263 * Lock status: No locks are assumed held.
2265 * Notes: There is no timer nor any other means by which the requests
2266 * get unblocked other than the low-level driver calling
2267 * scsi_unblock_requests().
2269 void scsi_block_requests(struct Scsi_Host *shost)
2271 shost->host_self_blocked = 1;
2273 EXPORT_SYMBOL(scsi_block_requests);
2276 * Function: scsi_unblock_requests()
2278 * Purpose: Utility function used by low-level drivers to allow further
2279 * commands from being queued to the device.
2281 * Arguments: shost - Host in question
2285 * Lock status: No locks are assumed held.
2287 * Notes: There is no timer nor any other means by which the requests
2288 * get unblocked other than the low-level driver calling
2289 * scsi_unblock_requests().
2291 * This is done as an API function so that changes to the
2292 * internals of the scsi mid-layer won't require wholesale
2293 * changes to drivers that use this feature.
2295 void scsi_unblock_requests(struct Scsi_Host *shost)
2297 shost->host_self_blocked = 0;
2298 scsi_run_host_queues(shost);
2300 EXPORT_SYMBOL(scsi_unblock_requests);
2302 int __init scsi_init_queue(void)
2304 scsi_sdb_cache = kmem_cache_create("scsi_data_buffer",
2305 sizeof(struct scsi_data_buffer),
2307 if (!scsi_sdb_cache) {
2308 printk(KERN_ERR "SCSI: can't init scsi sdb cache\n");
2315 void scsi_exit_queue(void)
2317 kmem_cache_destroy(scsi_sense_cache);
2318 kmem_cache_destroy(scsi_sense_isadma_cache);
2319 kmem_cache_destroy(scsi_sdb_cache);
2323 * scsi_mode_select - issue a mode select
2324 * @sdev: SCSI device to be queried
2325 * @pf: Page format bit (1 == standard, 0 == vendor specific)
2326 * @sp: Save page bit (0 == don't save, 1 == save)
2327 * @modepage: mode page being requested
2328 * @buffer: request buffer (may not be smaller than eight bytes)
2329 * @len: length of request buffer.
2330 * @timeout: command timeout
2331 * @retries: number of retries before failing
2332 * @data: returns a structure abstracting the mode header data
2333 * @sshdr: place to put sense data (or NULL if no sense to be collected).
2334 * must be SCSI_SENSE_BUFFERSIZE big.
2336 * Returns zero if successful; negative error number or scsi
2341 scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage,
2342 unsigned char *buffer, int len, int timeout, int retries,
2343 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
2345 unsigned char cmd[10];
2346 unsigned char *real_buffer;
2349 memset(cmd, 0, sizeof(cmd));
2350 cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0);
2352 if (sdev->use_10_for_ms) {
2355 real_buffer = kmalloc(8 + len, GFP_KERNEL);
2358 memcpy(real_buffer + 8, buffer, len);
2362 real_buffer[2] = data->medium_type;
2363 real_buffer[3] = data->device_specific;
2364 real_buffer[4] = data->longlba ? 0x01 : 0;
2366 real_buffer[6] = data->block_descriptor_length >> 8;
2367 real_buffer[7] = data->block_descriptor_length;
2369 cmd[0] = MODE_SELECT_10;
2373 if (len > 255 || data->block_descriptor_length > 255 ||
2377 real_buffer = kmalloc(4 + len, GFP_KERNEL);
2380 memcpy(real_buffer + 4, buffer, len);
2383 real_buffer[1] = data->medium_type;
2384 real_buffer[2] = data->device_specific;
2385 real_buffer[3] = data->block_descriptor_length;
2388 cmd[0] = MODE_SELECT;
2392 ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len,
2393 sshdr, timeout, retries, NULL);
2397 EXPORT_SYMBOL_GPL(scsi_mode_select);
2400 * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary.
2401 * @sdev: SCSI device to be queried
2402 * @dbd: set if mode sense will allow block descriptors to be returned
2403 * @modepage: mode page being requested
2404 * @buffer: request buffer (may not be smaller than eight bytes)
2405 * @len: length of request buffer.
2406 * @timeout: command timeout
2407 * @retries: number of retries before failing
2408 * @data: returns a structure abstracting the mode header data
2409 * @sshdr: place to put sense data (or NULL if no sense to be collected).
2410 * must be SCSI_SENSE_BUFFERSIZE big.
2412 * Returns zero if unsuccessful, or the header offset (either 4
2413 * or 8 depending on whether a six or ten byte command was
2414 * issued) if successful.
2417 scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
2418 unsigned char *buffer, int len, int timeout, int retries,
2419 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
2421 unsigned char cmd[12];
2424 int result, retry_count = retries;
2425 struct scsi_sense_hdr my_sshdr;
2427 memset(data, 0, sizeof(*data));
2428 memset(&cmd[0], 0, 12);
2429 cmd[1] = dbd & 0x18; /* allows DBD and LLBA bits */
2432 /* caller might not be interested in sense, but we need it */
2437 use_10_for_ms = sdev->use_10_for_ms;
2439 if (use_10_for_ms) {
2443 cmd[0] = MODE_SENSE_10;
2450 cmd[0] = MODE_SENSE;
2455 memset(buffer, 0, len);
2457 result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len,
2458 sshdr, timeout, retries, NULL);
2460 /* This code looks awful: what it's doing is making sure an
2461 * ILLEGAL REQUEST sense return identifies the actual command
2462 * byte as the problem. MODE_SENSE commands can return
2463 * ILLEGAL REQUEST if the code page isn't supported */
2465 if (use_10_for_ms && !scsi_status_is_good(result) &&
2466 (driver_byte(result) & DRIVER_SENSE)) {
2467 if (scsi_sense_valid(sshdr)) {
2468 if ((sshdr->sense_key == ILLEGAL_REQUEST) &&
2469 (sshdr->asc == 0x20) && (sshdr->ascq == 0)) {
2471 * Invalid command operation code
2473 sdev->use_10_for_ms = 0;
2479 if(scsi_status_is_good(result)) {
2480 if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b &&
2481 (modepage == 6 || modepage == 8))) {
2482 /* Initio breakage? */
2485 data->medium_type = 0;
2486 data->device_specific = 0;
2488 data->block_descriptor_length = 0;
2489 } else if(use_10_for_ms) {
2490 data->length = buffer[0]*256 + buffer[1] + 2;
2491 data->medium_type = buffer[2];
2492 data->device_specific = buffer[3];
2493 data->longlba = buffer[4] & 0x01;
2494 data->block_descriptor_length = buffer[6]*256
2497 data->length = buffer[0] + 1;
2498 data->medium_type = buffer[1];
2499 data->device_specific = buffer[2];
2500 data->block_descriptor_length = buffer[3];
2502 data->header_length = header_length;
2503 } else if ((status_byte(result) == CHECK_CONDITION) &&
2504 scsi_sense_valid(sshdr) &&
2505 sshdr->sense_key == UNIT_ATTENTION && retry_count) {
2512 EXPORT_SYMBOL(scsi_mode_sense);
2515 * scsi_test_unit_ready - test if unit is ready
2516 * @sdev: scsi device to change the state of.
2517 * @timeout: command timeout
2518 * @retries: number of retries before failing
2519 * @sshdr: outpout pointer for decoded sense information.
2521 * Returns zero if unsuccessful or an error if TUR failed. For
2522 * removable media, UNIT_ATTENTION sets ->changed flag.
2525 scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries,
2526 struct scsi_sense_hdr *sshdr)
2529 TEST_UNIT_READY, 0, 0, 0, 0, 0,
2533 /* try to eat the UNIT_ATTENTION if there are enough retries */
2535 result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr,
2536 timeout, retries, NULL);
2537 if (sdev->removable && scsi_sense_valid(sshdr) &&
2538 sshdr->sense_key == UNIT_ATTENTION)
2540 } while (scsi_sense_valid(sshdr) &&
2541 sshdr->sense_key == UNIT_ATTENTION && --retries);
2545 EXPORT_SYMBOL(scsi_test_unit_ready);
2548 * scsi_device_set_state - Take the given device through the device state model.
2549 * @sdev: scsi device to change the state of.
2550 * @state: state to change to.
2552 * Returns zero if successful or an error if the requested
2553 * transition is illegal.
2556 scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
2558 enum scsi_device_state oldstate = sdev->sdev_state;
2560 if (state == oldstate)
2566 case SDEV_CREATED_BLOCK:
2577 case SDEV_TRANSPORT_OFFLINE:
2590 case SDEV_TRANSPORT_OFFLINE:
2598 case SDEV_TRANSPORT_OFFLINE:
2613 case SDEV_CREATED_BLOCK:
2620 case SDEV_CREATED_BLOCK:
2635 case SDEV_TRANSPORT_OFFLINE:
2647 case SDEV_TRANSPORT_OFFLINE:
2650 case SDEV_CREATED_BLOCK:
2658 sdev->sdev_state = state;
2659 sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state");
2663 SCSI_LOG_ERROR_RECOVERY(1,
2664 sdev_printk(KERN_ERR, sdev,
2665 "Illegal state transition %s->%s",
2666 scsi_device_state_name(oldstate),
2667 scsi_device_state_name(state))
2671 EXPORT_SYMBOL(scsi_device_set_state);
2674 * sdev_evt_emit - emit a single SCSI device uevent
2675 * @sdev: associated SCSI device
2676 * @evt: event to emit
2678 * Send a single uevent (scsi_event) to the associated scsi_device.
2680 static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt)
2685 switch (evt->evt_type) {
2686 case SDEV_EVT_MEDIA_CHANGE:
2687 envp[idx++] = "SDEV_MEDIA_CHANGE=1";
2689 case SDEV_EVT_INQUIRY_CHANGE_REPORTED:
2690 scsi_rescan_device(&sdev->sdev_gendev);
2691 envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED";
2693 case SDEV_EVT_CAPACITY_CHANGE_REPORTED:
2694 envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED";
2696 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED:
2697 envp[idx++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED";
2699 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED:
2700 envp[idx++] = "SDEV_UA=MODE_PARAMETERS_CHANGED";
2702 case SDEV_EVT_LUN_CHANGE_REPORTED:
2703 envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED";
2705 case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED:
2706 envp[idx++] = "SDEV_UA=ASYMMETRIC_ACCESS_STATE_CHANGED";
2715 kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp);
2719 * sdev_evt_thread - send a uevent for each scsi event
2720 * @work: work struct for scsi_device
2722 * Dispatch queued events to their associated scsi_device kobjects
2725 void scsi_evt_thread(struct work_struct *work)
2727 struct scsi_device *sdev;
2728 enum scsi_device_event evt_type;
2729 LIST_HEAD(event_list);
2731 sdev = container_of(work, struct scsi_device, event_work);
2733 for (evt_type = SDEV_EVT_FIRST; evt_type <= SDEV_EVT_LAST; evt_type++)
2734 if (test_and_clear_bit(evt_type, sdev->pending_events))
2735 sdev_evt_send_simple(sdev, evt_type, GFP_KERNEL);
2738 struct scsi_event *evt;
2739 struct list_head *this, *tmp;
2740 unsigned long flags;
2742 spin_lock_irqsave(&sdev->list_lock, flags);
2743 list_splice_init(&sdev->event_list, &event_list);
2744 spin_unlock_irqrestore(&sdev->list_lock, flags);
2746 if (list_empty(&event_list))
2749 list_for_each_safe(this, tmp, &event_list) {
2750 evt = list_entry(this, struct scsi_event, node);
2751 list_del(&evt->node);
2752 scsi_evt_emit(sdev, evt);
2759 * sdev_evt_send - send asserted event to uevent thread
2760 * @sdev: scsi_device event occurred on
2761 * @evt: event to send
2763 * Assert scsi device event asynchronously.
2765 void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt)
2767 unsigned long flags;
2770 /* FIXME: currently this check eliminates all media change events
2771 * for polled devices. Need to update to discriminate between AN
2772 * and polled events */
2773 if (!test_bit(evt->evt_type, sdev->supported_events)) {
2779 spin_lock_irqsave(&sdev->list_lock, flags);
2780 list_add_tail(&evt->node, &sdev->event_list);
2781 schedule_work(&sdev->event_work);
2782 spin_unlock_irqrestore(&sdev->list_lock, flags);
2784 EXPORT_SYMBOL_GPL(sdev_evt_send);
2787 * sdev_evt_alloc - allocate a new scsi event
2788 * @evt_type: type of event to allocate
2789 * @gfpflags: GFP flags for allocation
2791 * Allocates and returns a new scsi_event.
2793 struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type,
2796 struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags);
2800 evt->evt_type = evt_type;
2801 INIT_LIST_HEAD(&evt->node);
2803 /* evt_type-specific initialization, if any */
2805 case SDEV_EVT_MEDIA_CHANGE:
2806 case SDEV_EVT_INQUIRY_CHANGE_REPORTED:
2807 case SDEV_EVT_CAPACITY_CHANGE_REPORTED:
2808 case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED:
2809 case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED:
2810 case SDEV_EVT_LUN_CHANGE_REPORTED:
2811 case SDEV_EVT_ALUA_STATE_CHANGE_REPORTED:
2819 EXPORT_SYMBOL_GPL(sdev_evt_alloc);
2822 * sdev_evt_send_simple - send asserted event to uevent thread
2823 * @sdev: scsi_device event occurred on
2824 * @evt_type: type of event to send
2825 * @gfpflags: GFP flags for allocation
2827 * Assert scsi device event asynchronously, given an event type.
2829 void sdev_evt_send_simple(struct scsi_device *sdev,
2830 enum scsi_device_event evt_type, gfp_t gfpflags)
2832 struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags);
2834 sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n",
2839 sdev_evt_send(sdev, evt);
2841 EXPORT_SYMBOL_GPL(sdev_evt_send_simple);
2844 * scsi_request_fn_active() - number of kernel threads inside scsi_request_fn()
2845 * @sdev: SCSI device to count the number of scsi_request_fn() callers for.
2847 static int scsi_request_fn_active(struct scsi_device *sdev)
2849 struct request_queue *q = sdev->request_queue;
2850 int request_fn_active;
2852 WARN_ON_ONCE(sdev->host->use_blk_mq);
2854 spin_lock_irq(q->queue_lock);
2855 request_fn_active = q->request_fn_active;
2856 spin_unlock_irq(q->queue_lock);
2858 return request_fn_active;
2862 * scsi_wait_for_queuecommand() - wait for ongoing queuecommand() calls
2863 * @sdev: SCSI device pointer.
2865 * Wait until the ongoing shost->hostt->queuecommand() calls that are
2866 * invoked from scsi_request_fn() have finished.
2868 static void scsi_wait_for_queuecommand(struct scsi_device *sdev)
2870 WARN_ON_ONCE(sdev->host->use_blk_mq);
2872 while (scsi_request_fn_active(sdev))
2877 * scsi_device_quiesce - Block user issued commands.
2878 * @sdev: scsi device to quiesce.
2880 * This works by trying to transition to the SDEV_QUIESCE state
2881 * (which must be a legal transition). When the device is in this
2882 * state, only special requests will be accepted, all others will
2883 * be deferred. Since special requests may also be requeued requests,
2884 * a successful return doesn't guarantee the device will be
2885 * totally quiescent.
2887 * Must be called with user context, may sleep.
2889 * Returns zero if unsuccessful or an error if not.
2892 scsi_device_quiesce(struct scsi_device *sdev)
2896 mutex_lock(&sdev->state_mutex);
2897 err = scsi_device_set_state(sdev, SDEV_QUIESCE);
2898 mutex_unlock(&sdev->state_mutex);
2903 scsi_run_queue(sdev->request_queue);
2904 while (atomic_read(&sdev->device_busy)) {
2905 msleep_interruptible(200);
2906 scsi_run_queue(sdev->request_queue);
2910 EXPORT_SYMBOL(scsi_device_quiesce);
2913 * scsi_device_resume - Restart user issued commands to a quiesced device.
2914 * @sdev: scsi device to resume.
2916 * Moves the device from quiesced back to running and restarts the
2919 * Must be called with user context, may sleep.
2921 void scsi_device_resume(struct scsi_device *sdev)
2923 /* check if the device state was mutated prior to resume, and if
2924 * so assume the state is being managed elsewhere (for example
2925 * device deleted during suspend)
2927 mutex_lock(&sdev->state_mutex);
2928 if (sdev->sdev_state == SDEV_QUIESCE &&
2929 scsi_device_set_state(sdev, SDEV_RUNNING) == 0)
2930 scsi_run_queue(sdev->request_queue);
2931 mutex_unlock(&sdev->state_mutex);
2933 EXPORT_SYMBOL(scsi_device_resume);
2936 device_quiesce_fn(struct scsi_device *sdev, void *data)
2938 scsi_device_quiesce(sdev);
2942 scsi_target_quiesce(struct scsi_target *starget)
2944 starget_for_each_device(starget, NULL, device_quiesce_fn);
2946 EXPORT_SYMBOL(scsi_target_quiesce);
2949 device_resume_fn(struct scsi_device *sdev, void *data)
2951 scsi_device_resume(sdev);
2955 scsi_target_resume(struct scsi_target *starget)
2957 starget_for_each_device(starget, NULL, device_resume_fn);
2959 EXPORT_SYMBOL(scsi_target_resume);
2962 * scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state
2963 * @sdev: device to block
2965 * Pause SCSI command processing on the specified device. Does not sleep.
2967 * Returns zero if successful or a negative error code upon failure.
2970 * This routine transitions the device to the SDEV_BLOCK state (which must be
2971 * a legal transition). When the device is in this state, command processing
2972 * is paused until the device leaves the SDEV_BLOCK state. See also
2973 * scsi_internal_device_unblock_nowait().
2975 int scsi_internal_device_block_nowait(struct scsi_device *sdev)
2977 struct request_queue *q = sdev->request_queue;
2978 unsigned long flags;
2981 err = scsi_device_set_state(sdev, SDEV_BLOCK);
2983 err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK);
2990 * The device has transitioned to SDEV_BLOCK. Stop the
2991 * block layer from calling the midlayer with this device's
2995 blk_mq_quiesce_queue_nowait(q);
2997 spin_lock_irqsave(q->queue_lock, flags);
2999 spin_unlock_irqrestore(q->queue_lock, flags);
3004 EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait);
3007 * scsi_internal_device_block - try to transition to the SDEV_BLOCK state
3008 * @sdev: device to block
3010 * Pause SCSI command processing on the specified device and wait until all
3011 * ongoing scsi_request_fn() / scsi_queue_rq() calls have finished. May sleep.
3013 * Returns zero if successful or a negative error code upon failure.
3016 * This routine transitions the device to the SDEV_BLOCK state (which must be
3017 * a legal transition). When the device is in this state, command processing
3018 * is paused until the device leaves the SDEV_BLOCK state. See also
3019 * scsi_internal_device_unblock().
3021 * To do: avoid that scsi_send_eh_cmnd() calls queuecommand() after
3022 * scsi_internal_device_block() has blocked a SCSI device and also
3023 * remove the rport mutex lock and unlock calls from srp_queuecommand().
3025 static int scsi_internal_device_block(struct scsi_device *sdev)
3027 struct request_queue *q = sdev->request_queue;
3030 mutex_lock(&sdev->state_mutex);
3031 err = scsi_internal_device_block_nowait(sdev);
3034 blk_mq_quiesce_queue(q);
3036 scsi_wait_for_queuecommand(sdev);
3038 mutex_unlock(&sdev->state_mutex);
3043 void scsi_start_queue(struct scsi_device *sdev)
3045 struct request_queue *q = sdev->request_queue;
3046 unsigned long flags;
3049 blk_mq_unquiesce_queue(q);
3051 spin_lock_irqsave(q->queue_lock, flags);
3053 spin_unlock_irqrestore(q->queue_lock, flags);
3058 * scsi_internal_device_unblock_nowait - resume a device after a block request
3059 * @sdev: device to resume
3060 * @new_state: state to set the device to after unblocking
3062 * Restart the device queue for a previously suspended SCSI device. Does not
3065 * Returns zero if successful or a negative error code upon failure.
3068 * This routine transitions the device to the SDEV_RUNNING state or to one of
3069 * the offline states (which must be a legal transition) allowing the midlayer
3070 * to goose the queue for this device.
3072 int scsi_internal_device_unblock_nowait(struct scsi_device *sdev,
3073 enum scsi_device_state new_state)
3076 * Try to transition the scsi device to SDEV_RUNNING or one of the
3077 * offlined states and goose the device queue if successful.
3079 switch (sdev->sdev_state) {
3081 case SDEV_TRANSPORT_OFFLINE:
3082 sdev->sdev_state = new_state;
3083 sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state");
3085 case SDEV_CREATED_BLOCK:
3086 if (new_state == SDEV_TRANSPORT_OFFLINE ||
3087 new_state == SDEV_OFFLINE)
3088 sdev->sdev_state = new_state;
3090 sdev->sdev_state = SDEV_CREATED;
3091 sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state");
3099 scsi_start_queue(sdev);
3103 EXPORT_SYMBOL_GPL(scsi_internal_device_unblock_nowait);
3106 * scsi_internal_device_unblock - resume a device after a block request
3107 * @sdev: device to resume
3108 * @new_state: state to set the device to after unblocking
3110 * Restart the device queue for a previously suspended SCSI device. May sleep.
3112 * Returns zero if successful or a negative error code upon failure.
3115 * This routine transitions the device to the SDEV_RUNNING state or to one of
3116 * the offline states (which must be a legal transition) allowing the midlayer
3117 * to goose the queue for this device.
3119 static int scsi_internal_device_unblock(struct scsi_device *sdev,
3120 enum scsi_device_state new_state)
3124 mutex_lock(&sdev->state_mutex);
3125 ret = scsi_internal_device_unblock_nowait(sdev, new_state);
3126 mutex_unlock(&sdev->state_mutex);
3132 device_block(struct scsi_device *sdev, void *data)
3134 scsi_internal_device_block(sdev);
3138 target_block(struct device *dev, void *data)
3140 if (scsi_is_target_device(dev))
3141 starget_for_each_device(to_scsi_target(dev), NULL,
3147 scsi_target_block(struct device *dev)
3149 if (scsi_is_target_device(dev))
3150 starget_for_each_device(to_scsi_target(dev), NULL,
3153 device_for_each_child(dev, NULL, target_block);
3155 EXPORT_SYMBOL_GPL(scsi_target_block);
3158 device_unblock(struct scsi_device *sdev, void *data)
3160 scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data);
3164 target_unblock(struct device *dev, void *data)
3166 if (scsi_is_target_device(dev))
3167 starget_for_each_device(to_scsi_target(dev), data,
3173 scsi_target_unblock(struct device *dev, enum scsi_device_state new_state)
3175 if (scsi_is_target_device(dev))
3176 starget_for_each_device(to_scsi_target(dev), &new_state,
3179 device_for_each_child(dev, &new_state, target_unblock);
3181 EXPORT_SYMBOL_GPL(scsi_target_unblock);
3184 * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt
3185 * @sgl: scatter-gather list
3186 * @sg_count: number of segments in sg
3187 * @offset: offset in bytes into sg, on return offset into the mapped area
3188 * @len: bytes to map, on return number of bytes mapped
3190 * Returns virtual address of the start of the mapped page
3192 void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count,
3193 size_t *offset, size_t *len)
3196 size_t sg_len = 0, len_complete = 0;
3197 struct scatterlist *sg;
3200 WARN_ON(!irqs_disabled());
3202 for_each_sg(sgl, sg, sg_count, i) {
3203 len_complete = sg_len; /* Complete sg-entries */
3204 sg_len += sg->length;
3205 if (sg_len > *offset)
3209 if (unlikely(i == sg_count)) {
3210 printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, "
3212 __func__, sg_len, *offset, sg_count);
3217 /* Offset starting from the beginning of first page in this sg-entry */
3218 *offset = *offset - len_complete + sg->offset;
3220 /* Assumption: contiguous pages can be accessed as "page + i" */
3221 page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT));
3222 *offset &= ~PAGE_MASK;
3224 /* Bytes in this sg-entry from *offset to the end of the page */
3225 sg_len = PAGE_SIZE - *offset;
3229 return kmap_atomic(page);
3231 EXPORT_SYMBOL(scsi_kmap_atomic_sg);
3234 * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg
3235 * @virt: virtual address to be unmapped
3237 void scsi_kunmap_atomic_sg(void *virt)
3239 kunmap_atomic(virt);
3241 EXPORT_SYMBOL(scsi_kunmap_atomic_sg);
3243 void sdev_disable_disk_events(struct scsi_device *sdev)
3245 atomic_inc(&sdev->disk_events_disable_depth);
3247 EXPORT_SYMBOL(sdev_disable_disk_events);
3249 void sdev_enable_disk_events(struct scsi_device *sdev)
3251 if (WARN_ON_ONCE(atomic_read(&sdev->disk_events_disable_depth) <= 0))
3253 atomic_dec(&sdev->disk_events_disable_depth);
3255 EXPORT_SYMBOL(sdev_enable_disk_events);
3258 * scsi_vpd_lun_id - return a unique device identification
3259 * @sdev: SCSI device
3260 * @id: buffer for the identification
3261 * @id_len: length of the buffer
3263 * Copies a unique device identification into @id based
3264 * on the information in the VPD page 0x83 of the device.
3265 * The string will be formatted as a SCSI name string.
3267 * Returns the length of the identification or error on failure.
3268 * If the identifier is longer than the supplied buffer the actual
3269 * identifier length is returned and the buffer is not zero-padded.
3271 int scsi_vpd_lun_id(struct scsi_device *sdev, char *id, size_t id_len)
3273 u8 cur_id_type = 0xff;
3275 const unsigned char *d, *cur_id_str;
3276 const struct scsi_vpd *vpd_pg83;
3277 int id_size = -EINVAL;
3280 vpd_pg83 = rcu_dereference(sdev->vpd_pg83);
3287 * Look for the correct descriptor.
3288 * Order of preference for lun descriptor:
3289 * - SCSI name string
3290 * - NAA IEEE Registered Extended
3291 * - EUI-64 based 16-byte
3292 * - EUI-64 based 12-byte
3293 * - NAA IEEE Registered
3294 * - NAA IEEE Extended
3296 * as longer descriptors reduce the likelyhood
3297 * of identification clashes.
3300 /* The id string must be at least 20 bytes + terminating NULL byte */
3306 memset(id, 0, id_len);
3307 d = vpd_pg83->data + 4;
3308 while (d < vpd_pg83->data + vpd_pg83->len) {
3309 /* Skip designators not referring to the LUN */
3310 if ((d[1] & 0x30) != 0x00)
3313 switch (d[1] & 0xf) {
3316 if (cur_id_size > d[3])
3318 /* Prefer anything */
3319 if (cur_id_type > 0x01 && cur_id_type != 0xff)
3322 if (cur_id_size + 4 > id_len)
3323 cur_id_size = id_len - 4;
3325 cur_id_type = d[1] & 0xf;
3326 id_size = snprintf(id, id_len, "t10.%*pE",
3327 cur_id_size, cur_id_str);
3331 if (cur_id_size > d[3])
3333 /* Prefer NAA IEEE Registered Extended */
3334 if (cur_id_type == 0x3 &&
3335 cur_id_size == d[3])
3339 cur_id_type = d[1] & 0xf;
3340 switch (cur_id_size) {
3342 id_size = snprintf(id, id_len,
3347 id_size = snprintf(id, id_len,
3352 id_size = snprintf(id, id_len,
3363 if (cur_id_size > d[3])
3367 cur_id_type = d[1] & 0xf;
3368 switch (cur_id_size) {
3370 id_size = snprintf(id, id_len,
3375 id_size = snprintf(id, id_len,
3385 /* SCSI name string */
3386 if (cur_id_size + 4 > d[3])
3388 /* Prefer others for truncated descriptor */
3389 if (cur_id_size && d[3] > id_len)
3391 cur_id_size = id_size = d[3];
3393 cur_id_type = d[1] & 0xf;
3394 if (cur_id_size >= id_len)
3395 cur_id_size = id_len - 1;
3396 memcpy(id, cur_id_str, cur_id_size);
3397 /* Decrease priority for truncated descriptor */
3398 if (cur_id_size != id_size)
3411 EXPORT_SYMBOL(scsi_vpd_lun_id);
3414 * scsi_vpd_tpg_id - return a target port group identifier
3415 * @sdev: SCSI device
3417 * Returns the Target Port Group identifier from the information
3418 * froom VPD page 0x83 of the device.
3420 * Returns the identifier or error on failure.
3422 int scsi_vpd_tpg_id(struct scsi_device *sdev, int *rel_id)
3424 const unsigned char *d;
3425 const struct scsi_vpd *vpd_pg83;
3426 int group_id = -EAGAIN, rel_port = -1;
3429 vpd_pg83 = rcu_dereference(sdev->vpd_pg83);
3435 d = vpd_pg83->data + 4;
3436 while (d < vpd_pg83->data + vpd_pg83->len) {
3437 switch (d[1] & 0xf) {
3439 /* Relative target port */
3440 rel_port = get_unaligned_be16(&d[6]);
3443 /* Target port group */
3444 group_id = get_unaligned_be16(&d[6]);
3453 if (group_id >= 0 && rel_id && rel_port != -1)
3458 EXPORT_SYMBOL(scsi_vpd_tpg_id);