2 * Copyright (C) 2016 Red Hat, Inc. All rights reserved.
4 * This file is released under the GPL.
10 #include <linux/elevator.h> /* for rq_end_sector() */
11 #include <linux/blk-mq.h>
13 #define DM_MSG_PREFIX "core-rq"
15 #define DM_MQ_NR_HW_QUEUES 1
16 #define DM_MQ_QUEUE_DEPTH 2048
17 static unsigned dm_mq_nr_hw_queues
= DM_MQ_NR_HW_QUEUES
;
18 static unsigned dm_mq_queue_depth
= DM_MQ_QUEUE_DEPTH
;
21 * Request-based DM's mempools' reserved IOs set by the user.
23 #define RESERVED_REQUEST_BASED_IOS 256
24 static unsigned reserved_rq_based_ios
= RESERVED_REQUEST_BASED_IOS
;
26 #ifdef CONFIG_DM_MQ_DEFAULT
27 static bool use_blk_mq
= true;
29 static bool use_blk_mq
= false;
32 bool dm_use_blk_mq_default(void)
37 bool dm_use_blk_mq(struct mapped_device
*md
)
39 return md
->use_blk_mq
;
41 EXPORT_SYMBOL_GPL(dm_use_blk_mq
);
43 unsigned dm_get_reserved_rq_based_ios(void)
45 return __dm_get_module_param(&reserved_rq_based_ios
,
46 RESERVED_REQUEST_BASED_IOS
, DM_RESERVED_MAX_IOS
);
48 EXPORT_SYMBOL_GPL(dm_get_reserved_rq_based_ios
);
50 static unsigned dm_get_blk_mq_nr_hw_queues(void)
52 return __dm_get_module_param(&dm_mq_nr_hw_queues
, 1, 32);
55 static unsigned dm_get_blk_mq_queue_depth(void)
57 return __dm_get_module_param(&dm_mq_queue_depth
,
58 DM_MQ_QUEUE_DEPTH
, BLK_MQ_MAX_DEPTH
);
61 int dm_request_based(struct mapped_device
*md
)
63 return blk_queue_stackable(md
->queue
);
66 static void dm_old_start_queue(struct request_queue
*q
)
70 spin_lock_irqsave(q
->queue_lock
, flags
);
71 if (blk_queue_stopped(q
))
73 spin_unlock_irqrestore(q
->queue_lock
, flags
);
76 void dm_start_queue(struct request_queue
*q
)
79 dm_old_start_queue(q
);
81 blk_mq_start_stopped_hw_queues(q
, true);
82 blk_mq_kick_requeue_list(q
);
86 static void dm_old_stop_queue(struct request_queue
*q
)
90 spin_lock_irqsave(q
->queue_lock
, flags
);
91 if (blk_queue_stopped(q
)) {
92 spin_unlock_irqrestore(q
->queue_lock
, flags
);
97 spin_unlock_irqrestore(q
->queue_lock
, flags
);
100 void dm_stop_queue(struct request_queue
*q
)
103 dm_old_stop_queue(q
);
105 blk_mq_stop_hw_queues(q
);
108 static struct dm_rq_target_io
*alloc_old_rq_tio(struct mapped_device
*md
,
111 return mempool_alloc(md
->io_pool
, gfp_mask
);
114 static void free_old_rq_tio(struct dm_rq_target_io
*tio
)
116 mempool_free(tio
, tio
->md
->io_pool
);
119 static struct request
*alloc_old_clone_request(struct mapped_device
*md
,
122 return mempool_alloc(md
->rq_pool
, gfp_mask
);
125 static void free_old_clone_request(struct mapped_device
*md
, struct request
*rq
)
127 mempool_free(rq
, md
->rq_pool
);
131 * Partial completion handling for request-based dm
133 static void end_clone_bio(struct bio
*clone
)
135 struct dm_rq_clone_bio_info
*info
=
136 container_of(clone
, struct dm_rq_clone_bio_info
, clone
);
137 struct dm_rq_target_io
*tio
= info
->tio
;
138 struct bio
*bio
= info
->orig
;
139 unsigned int nr_bytes
= info
->orig
->bi_iter
.bi_size
;
140 int error
= clone
->bi_error
;
146 * An error has already been detected on the request.
147 * Once error occurred, just let clone->end_io() handle
153 * Don't notice the error to the upper layer yet.
154 * The error handling decision is made by the target driver,
155 * when the request is completed.
162 * I/O for the bio successfully completed.
163 * Notice the data completion to the upper layer.
167 * bios are processed from the head of the list.
168 * So the completing bio should always be rq->bio.
169 * If it's not, something wrong is happening.
171 if (tio
->orig
->bio
!= bio
)
172 DMERR("bio completion is going in the middle of the request");
175 * Update the original request.
176 * Do not use blk_end_request() here, because it may complete
177 * the original request before the clone, and break the ordering.
179 blk_update_request(tio
->orig
, 0, nr_bytes
);
182 static struct dm_rq_target_io
*tio_from_request(struct request
*rq
)
184 return (rq
->q
->mq_ops
? blk_mq_rq_to_pdu(rq
) : rq
->special
);
187 static void rq_end_stats(struct mapped_device
*md
, struct request
*orig
)
189 if (unlikely(dm_stats_used(&md
->stats
))) {
190 struct dm_rq_target_io
*tio
= tio_from_request(orig
);
191 tio
->duration_jiffies
= jiffies
- tio
->duration_jiffies
;
192 dm_stats_account_io(&md
->stats
, rq_data_dir(orig
),
193 blk_rq_pos(orig
), tio
->n_sectors
, true,
194 tio
->duration_jiffies
, &tio
->stats_aux
);
199 * Don't touch any member of the md after calling this function because
200 * the md may be freed in dm_put() at the end of this function.
201 * Or do dm_get() before calling this function and dm_put() later.
203 static void rq_completed(struct mapped_device
*md
, int rw
, bool run_queue
)
205 atomic_dec(&md
->pending
[rw
]);
207 /* nudge anyone waiting on suspend queue */
208 if (!md_in_flight(md
))
212 * Run this off this callpath, as drivers could invoke end_io while
213 * inside their request_fn (and holding the queue lock). Calling
214 * back into ->request_fn() could deadlock attempting to grab the
217 if (!md
->queue
->mq_ops
&& run_queue
)
218 blk_run_queue_async(md
->queue
);
221 * dm_put() must be at the end of this function. See the comment above
226 static void free_rq_clone(struct request
*clone
)
228 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
229 struct mapped_device
*md
= tio
->md
;
231 blk_rq_unprep_clone(clone
);
234 * It is possible for a clone_old_rq() allocated clone to
235 * get passed in -- it may not yet have a request_queue.
236 * This is known to occur if the error target replaces
237 * a multipath target that has a request_fn queue stacked
238 * on blk-mq queue(s).
240 if (clone
->q
&& clone
->q
->mq_ops
)
241 /* stacked on blk-mq queue(s) */
242 tio
->ti
->type
->release_clone_rq(clone
);
243 else if (!md
->queue
->mq_ops
)
244 /* request_fn queue stacked on request_fn queue(s) */
245 free_old_clone_request(md
, clone
);
247 if (!md
->queue
->mq_ops
)
248 free_old_rq_tio(tio
);
252 * Complete the clone and the original request.
253 * Must be called without clone's queue lock held,
254 * see end_clone_request() for more details.
256 static void dm_end_request(struct request
*clone
, int error
)
258 int rw
= rq_data_dir(clone
);
259 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
260 struct mapped_device
*md
= tio
->md
;
261 struct request
*rq
= tio
->orig
;
263 if (rq
->cmd_type
== REQ_TYPE_BLOCK_PC
) {
264 rq
->errors
= clone
->errors
;
265 rq
->resid_len
= clone
->resid_len
;
269 * We are using the sense buffer of the original
271 * So setting the length of the sense data is enough.
273 rq
->sense_len
= clone
->sense_len
;
276 free_rq_clone(clone
);
277 rq_end_stats(md
, rq
);
279 blk_end_request_all(rq
, error
);
281 blk_mq_end_request(rq
, error
);
282 rq_completed(md
, rw
, true);
285 static void dm_unprep_request(struct request
*rq
)
287 struct dm_rq_target_io
*tio
= tio_from_request(rq
);
288 struct request
*clone
= tio
->clone
;
290 if (!rq
->q
->mq_ops
) {
292 rq
->cmd_flags
&= ~REQ_DONTPREP
;
296 free_rq_clone(clone
);
297 else if (!tio
->md
->queue
->mq_ops
)
298 free_old_rq_tio(tio
);
302 * Requeue the original request of a clone.
304 static void dm_old_requeue_request(struct request
*rq
)
306 struct request_queue
*q
= rq
->q
;
309 spin_lock_irqsave(q
->queue_lock
, flags
);
310 blk_requeue_request(q
, rq
);
311 blk_run_queue_async(q
);
312 spin_unlock_irqrestore(q
->queue_lock
, flags
);
315 static void dm_mq_requeue_request(struct request
*rq
)
317 struct request_queue
*q
= rq
->q
;
320 blk_mq_requeue_request(rq
);
321 spin_lock_irqsave(q
->queue_lock
, flags
);
322 if (!blk_queue_stopped(q
))
323 blk_mq_kick_requeue_list(q
);
324 spin_unlock_irqrestore(q
->queue_lock
, flags
);
327 static void dm_requeue_original_request(struct mapped_device
*md
,
330 int rw
= rq_data_dir(rq
);
332 rq_end_stats(md
, rq
);
333 dm_unprep_request(rq
);
336 dm_old_requeue_request(rq
);
338 dm_mq_requeue_request(rq
);
340 rq_completed(md
, rw
, false);
343 static void dm_done(struct request
*clone
, int error
, bool mapped
)
346 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
347 dm_request_endio_fn rq_end_io
= NULL
;
350 rq_end_io
= tio
->ti
->type
->rq_end_io
;
352 if (mapped
&& rq_end_io
)
353 r
= rq_end_io(tio
->ti
, clone
, error
, &tio
->info
);
356 if (unlikely(r
== -EREMOTEIO
&& (req_op(clone
) == REQ_OP_WRITE_SAME
) &&
357 !clone
->q
->limits
.max_write_same_sectors
))
358 disable_write_same(tio
->md
);
361 /* The target wants to complete the I/O */
362 dm_end_request(clone
, r
);
363 else if (r
== DM_ENDIO_INCOMPLETE
)
364 /* The target will handle the I/O */
366 else if (r
== DM_ENDIO_REQUEUE
)
367 /* The target wants to requeue the I/O */
368 dm_requeue_original_request(tio
->md
, tio
->orig
);
370 DMWARN("unimplemented target endio return value: %d", r
);
376 * Request completion handler for request-based dm
378 static void dm_softirq_done(struct request
*rq
)
381 struct dm_rq_target_io
*tio
= tio_from_request(rq
);
382 struct request
*clone
= tio
->clone
;
386 rq_end_stats(tio
->md
, rq
);
387 rw
= rq_data_dir(rq
);
388 if (!rq
->q
->mq_ops
) {
389 blk_end_request_all(rq
, tio
->error
);
390 rq_completed(tio
->md
, rw
, false);
391 free_old_rq_tio(tio
);
393 blk_mq_end_request(rq
, tio
->error
);
394 rq_completed(tio
->md
, rw
, false);
399 if (rq
->cmd_flags
& REQ_FAILED
)
402 dm_done(clone
, tio
->error
, mapped
);
406 * Complete the clone and the original request with the error status
407 * through softirq context.
409 static void dm_complete_request(struct request
*rq
, int error
)
411 struct dm_rq_target_io
*tio
= tio_from_request(rq
);
415 blk_complete_request(rq
);
417 blk_mq_complete_request(rq
, error
);
421 * Complete the not-mapped clone and the original request with the error status
422 * through softirq context.
423 * Target's rq_end_io() function isn't called.
424 * This may be used when the target's map_rq() or clone_and_map_rq() functions fail.
426 static void dm_kill_unmapped_request(struct request
*rq
, int error
)
428 rq
->cmd_flags
|= REQ_FAILED
;
429 dm_complete_request(rq
, error
);
433 * Called with the clone's queue lock held (in the case of .request_fn)
435 static void end_clone_request(struct request
*clone
, int error
)
437 struct dm_rq_target_io
*tio
= clone
->end_io_data
;
439 if (!clone
->q
->mq_ops
) {
441 * For just cleaning up the information of the queue in which
442 * the clone was dispatched.
443 * The clone is *NOT* freed actually here because it is alloced
444 * from dm own mempool (REQ_ALLOCED isn't set).
446 __blk_put_request(clone
->q
, clone
);
450 * Actual request completion is done in a softirq context which doesn't
451 * hold the clone's queue lock. Otherwise, deadlock could occur because:
452 * - another request may be submitted by the upper level driver
453 * of the stacking during the completion
454 * - the submission which requires queue lock may be done
455 * against this clone's queue
457 dm_complete_request(tio
->orig
, error
);
460 static void dm_dispatch_clone_request(struct request
*clone
, struct request
*rq
)
464 if (blk_queue_io_stat(clone
->q
))
465 clone
->cmd_flags
|= REQ_IO_STAT
;
467 clone
->start_time
= jiffies
;
468 r
= blk_insert_cloned_request(clone
->q
, clone
);
470 /* must complete clone in terms of original request */
471 dm_complete_request(rq
, r
);
474 static int dm_rq_bio_constructor(struct bio
*bio
, struct bio
*bio_orig
,
477 struct dm_rq_target_io
*tio
= data
;
478 struct dm_rq_clone_bio_info
*info
=
479 container_of(bio
, struct dm_rq_clone_bio_info
, clone
);
481 info
->orig
= bio_orig
;
483 bio
->bi_end_io
= end_clone_bio
;
488 static int setup_clone(struct request
*clone
, struct request
*rq
,
489 struct dm_rq_target_io
*tio
, gfp_t gfp_mask
)
493 r
= blk_rq_prep_clone(clone
, rq
, tio
->md
->bs
, gfp_mask
,
494 dm_rq_bio_constructor
, tio
);
498 clone
->cmd
= rq
->cmd
;
499 clone
->cmd_len
= rq
->cmd_len
;
500 clone
->sense
= rq
->sense
;
501 clone
->end_io
= end_clone_request
;
502 clone
->end_io_data
= tio
;
509 static struct request
*clone_old_rq(struct request
*rq
, struct mapped_device
*md
,
510 struct dm_rq_target_io
*tio
, gfp_t gfp_mask
)
513 * Create clone for use with .request_fn request_queue
515 struct request
*clone
;
517 clone
= alloc_old_clone_request(md
, gfp_mask
);
521 blk_rq_init(NULL
, clone
);
522 if (setup_clone(clone
, rq
, tio
, gfp_mask
)) {
524 free_old_clone_request(md
, clone
);
531 static void map_tio_request(struct kthread_work
*work
);
533 static void init_tio(struct dm_rq_target_io
*tio
, struct request
*rq
,
534 struct mapped_device
*md
)
542 * Avoid initializing info for blk-mq; it passes
543 * target-specific data through info.ptr
544 * (see: dm_mq_init_request)
546 if (!md
->init_tio_pdu
)
547 memset(&tio
->info
, 0, sizeof(tio
->info
));
548 if (md
->kworker_task
)
549 init_kthread_work(&tio
->work
, map_tio_request
);
552 static struct dm_rq_target_io
*dm_old_prep_tio(struct request
*rq
,
553 struct mapped_device
*md
,
556 struct dm_rq_target_io
*tio
;
558 struct dm_table
*table
;
560 tio
= alloc_old_rq_tio(md
, gfp_mask
);
564 init_tio(tio
, rq
, md
);
566 table
= dm_get_live_table(md
, &srcu_idx
);
568 * Must clone a request if this .request_fn DM device
569 * is stacked on .request_fn device(s).
571 if (!dm_table_all_blk_mq_devices(table
)) {
572 if (!clone_old_rq(rq
, md
, tio
, gfp_mask
)) {
573 dm_put_live_table(md
, srcu_idx
);
574 free_old_rq_tio(tio
);
578 dm_put_live_table(md
, srcu_idx
);
584 * Called with the queue lock held.
586 static int dm_old_prep_fn(struct request_queue
*q
, struct request
*rq
)
588 struct mapped_device
*md
= q
->queuedata
;
589 struct dm_rq_target_io
*tio
;
591 if (unlikely(rq
->special
)) {
592 DMWARN("Already has something in rq->special.");
596 tio
= dm_old_prep_tio(rq
, md
, GFP_ATOMIC
);
598 return BLKPREP_DEFER
;
601 rq
->cmd_flags
|= REQ_DONTPREP
;
608 * 0 : the request has been processed
609 * DM_MAPIO_REQUEUE : the original request needs to be requeued
610 * < 0 : the request was completed due to failure
612 static int map_request(struct dm_rq_target_io
*tio
, struct request
*rq
,
613 struct mapped_device
*md
)
616 struct dm_target
*ti
= tio
->ti
;
617 struct request
*clone
= NULL
;
621 r
= ti
->type
->map_rq(ti
, clone
, &tio
->info
);
623 r
= ti
->type
->clone_and_map_rq(ti
, rq
, &tio
->info
, &clone
);
625 /* The target wants to complete the I/O */
626 dm_kill_unmapped_request(rq
, r
);
629 if (r
!= DM_MAPIO_REMAPPED
)
631 if (setup_clone(clone
, rq
, tio
, GFP_ATOMIC
)) {
633 ti
->type
->release_clone_rq(clone
);
634 return DM_MAPIO_REQUEUE
;
639 case DM_MAPIO_SUBMITTED
:
640 /* The target has taken the I/O to submit by itself later */
642 case DM_MAPIO_REMAPPED
:
643 /* The target has remapped the I/O so dispatch it */
644 trace_block_rq_remap(clone
->q
, clone
, disk_devt(dm_disk(md
)),
646 dm_dispatch_clone_request(clone
, rq
);
648 case DM_MAPIO_REQUEUE
:
649 /* The target wants to requeue the I/O */
650 dm_requeue_original_request(md
, tio
->orig
);
654 DMWARN("unimplemented target map return value: %d", r
);
658 /* The target wants to complete the I/O */
659 dm_kill_unmapped_request(rq
, r
);
666 static void dm_start_request(struct mapped_device
*md
, struct request
*orig
)
668 if (!orig
->q
->mq_ops
)
669 blk_start_request(orig
);
671 blk_mq_start_request(orig
);
672 atomic_inc(&md
->pending
[rq_data_dir(orig
)]);
674 if (md
->seq_rq_merge_deadline_usecs
) {
675 md
->last_rq_pos
= rq_end_sector(orig
);
676 md
->last_rq_rw
= rq_data_dir(orig
);
677 md
->last_rq_start_time
= ktime_get();
680 if (unlikely(dm_stats_used(&md
->stats
))) {
681 struct dm_rq_target_io
*tio
= tio_from_request(orig
);
682 tio
->duration_jiffies
= jiffies
;
683 tio
->n_sectors
= blk_rq_sectors(orig
);
684 dm_stats_account_io(&md
->stats
, rq_data_dir(orig
),
685 blk_rq_pos(orig
), tio
->n_sectors
, false, 0,
690 * Hold the md reference here for the in-flight I/O.
691 * We can't rely on the reference count by device opener,
692 * because the device may be closed during the request completion
693 * when all bios are completed.
694 * See the comment in rq_completed() too.
699 static void map_tio_request(struct kthread_work
*work
)
701 struct dm_rq_target_io
*tio
= container_of(work
, struct dm_rq_target_io
, work
);
702 struct request
*rq
= tio
->orig
;
703 struct mapped_device
*md
= tio
->md
;
705 if (map_request(tio
, rq
, md
) == DM_MAPIO_REQUEUE
)
706 dm_requeue_original_request(md
, rq
);
709 ssize_t
dm_attr_rq_based_seq_io_merge_deadline_show(struct mapped_device
*md
, char *buf
)
711 return sprintf(buf
, "%u\n", md
->seq_rq_merge_deadline_usecs
);
714 #define MAX_SEQ_RQ_MERGE_DEADLINE_USECS 100000
716 ssize_t
dm_attr_rq_based_seq_io_merge_deadline_store(struct mapped_device
*md
,
717 const char *buf
, size_t count
)
721 if (dm_get_md_type(md
) != DM_TYPE_REQUEST_BASED
)
724 if (kstrtouint(buf
, 10, &deadline
))
727 if (deadline
> MAX_SEQ_RQ_MERGE_DEADLINE_USECS
)
728 deadline
= MAX_SEQ_RQ_MERGE_DEADLINE_USECS
;
730 md
->seq_rq_merge_deadline_usecs
= deadline
;
735 static bool dm_old_request_peeked_before_merge_deadline(struct mapped_device
*md
)
739 if (!md
->seq_rq_merge_deadline_usecs
)
742 kt_deadline
= ns_to_ktime((u64
)md
->seq_rq_merge_deadline_usecs
* NSEC_PER_USEC
);
743 kt_deadline
= ktime_add_safe(md
->last_rq_start_time
, kt_deadline
);
745 return !ktime_after(ktime_get(), kt_deadline
);
749 * q->request_fn for old request-based dm.
750 * Called with the queue lock held.
752 static void dm_old_request_fn(struct request_queue
*q
)
754 struct mapped_device
*md
= q
->queuedata
;
755 struct dm_target
*ti
= md
->immutable_target
;
757 struct dm_rq_target_io
*tio
;
762 struct dm_table
*map
= dm_get_live_table(md
, &srcu_idx
);
764 ti
= dm_table_find_target(map
, pos
);
765 dm_put_live_table(md
, srcu_idx
);
769 * For suspend, check blk_queue_stopped() and increment
770 * ->pending within a single queue_lock not to increment the
771 * number of in-flight I/Os after the queue is stopped in
774 while (!blk_queue_stopped(q
)) {
775 rq
= blk_peek_request(q
);
779 /* always use block 0 to find the target for flushes for now */
781 if (req_op(rq
) != REQ_OP_FLUSH
)
782 pos
= blk_rq_pos(rq
);
784 if ((dm_old_request_peeked_before_merge_deadline(md
) &&
785 md_in_flight(md
) && rq
->bio
&& rq
->bio
->bi_vcnt
== 1 &&
786 md
->last_rq_pos
== pos
&& md
->last_rq_rw
== rq_data_dir(rq
)) ||
787 (ti
->type
->busy
&& ti
->type
->busy(ti
))) {
788 blk_delay_queue(q
, 10);
792 dm_start_request(md
, rq
);
794 tio
= tio_from_request(rq
);
795 /* Establish tio->ti before queuing work (map_tio_request) */
797 queue_kthread_work(&md
->kworker
, &tio
->work
);
798 BUG_ON(!irqs_disabled());
803 * Fully initialize a .request_fn request-based queue.
805 int dm_old_init_request_queue(struct mapped_device
*md
)
807 /* Fully initialize the queue */
808 if (!blk_init_allocated_queue(md
->queue
, dm_old_request_fn
, NULL
))
811 /* disable dm_old_request_fn's merge heuristic by default */
812 md
->seq_rq_merge_deadline_usecs
= 0;
814 dm_init_normal_md_queue(md
);
815 blk_queue_softirq_done(md
->queue
, dm_softirq_done
);
816 blk_queue_prep_rq(md
->queue
, dm_old_prep_fn
);
818 /* Initialize the request-based DM worker thread */
819 init_kthread_worker(&md
->kworker
);
820 md
->kworker_task
= kthread_run(kthread_worker_fn
, &md
->kworker
,
821 "kdmwork-%s", dm_device_name(md
));
822 if (IS_ERR(md
->kworker_task
))
823 return PTR_ERR(md
->kworker_task
);
825 elv_register_queue(md
->queue
);
830 static int dm_mq_init_request(void *data
, struct request
*rq
,
831 unsigned int hctx_idx
, unsigned int request_idx
,
832 unsigned int numa_node
)
834 struct mapped_device
*md
= data
;
835 struct dm_rq_target_io
*tio
= blk_mq_rq_to_pdu(rq
);
838 * Must initialize md member of tio, otherwise it won't
839 * be available in dm_mq_queue_rq.
843 if (md
->init_tio_pdu
) {
844 /* target-specific per-io data is immediately after the tio */
845 tio
->info
.ptr
= tio
+ 1;
851 static int dm_mq_queue_rq(struct blk_mq_hw_ctx
*hctx
,
852 const struct blk_mq_queue_data
*bd
)
854 struct request
*rq
= bd
->rq
;
855 struct dm_rq_target_io
*tio
= blk_mq_rq_to_pdu(rq
);
856 struct mapped_device
*md
= tio
->md
;
857 struct dm_target
*ti
= md
->immutable_target
;
861 struct dm_table
*map
= dm_get_live_table(md
, &srcu_idx
);
863 ti
= dm_table_find_target(map
, 0);
864 dm_put_live_table(md
, srcu_idx
);
867 if (ti
->type
->busy
&& ti
->type
->busy(ti
))
868 return BLK_MQ_RQ_QUEUE_BUSY
;
870 dm_start_request(md
, rq
);
872 /* Init tio using md established in .init_request */
873 init_tio(tio
, rq
, md
);
876 * Establish tio->ti before calling map_request().
880 /* Direct call is fine since .queue_rq allows allocations */
881 if (map_request(tio
, rq
, md
) == DM_MAPIO_REQUEUE
) {
882 /* Undo dm_start_request() before requeuing */
883 rq_end_stats(md
, rq
);
884 rq_completed(md
, rq_data_dir(rq
), false);
885 return BLK_MQ_RQ_QUEUE_BUSY
;
888 return BLK_MQ_RQ_QUEUE_OK
;
891 static struct blk_mq_ops dm_mq_ops
= {
892 .queue_rq
= dm_mq_queue_rq
,
893 .map_queue
= blk_mq_map_queue
,
894 .complete
= dm_softirq_done
,
895 .init_request
= dm_mq_init_request
,
898 int dm_mq_init_request_queue(struct mapped_device
*md
, struct dm_table
*t
)
900 struct request_queue
*q
;
901 struct dm_target
*immutable_tgt
;
904 if (!dm_table_all_blk_mq_devices(t
)) {
905 DMERR("request-based dm-mq may only be stacked on blk-mq device(s)");
909 md
->tag_set
= kzalloc_node(sizeof(struct blk_mq_tag_set
), GFP_KERNEL
, md
->numa_node_id
);
913 md
->tag_set
->ops
= &dm_mq_ops
;
914 md
->tag_set
->queue_depth
= dm_get_blk_mq_queue_depth();
915 md
->tag_set
->numa_node
= md
->numa_node_id
;
916 md
->tag_set
->flags
= BLK_MQ_F_SHOULD_MERGE
| BLK_MQ_F_SG_MERGE
;
917 md
->tag_set
->nr_hw_queues
= dm_get_blk_mq_nr_hw_queues();
918 md
->tag_set
->driver_data
= md
;
920 md
->tag_set
->cmd_size
= sizeof(struct dm_rq_target_io
);
921 immutable_tgt
= dm_table_get_immutable_target(t
);
922 if (immutable_tgt
&& immutable_tgt
->per_io_data_size
) {
923 /* any target-specific per-io data is immediately after the tio */
924 md
->tag_set
->cmd_size
+= immutable_tgt
->per_io_data_size
;
925 md
->init_tio_pdu
= true;
928 err
= blk_mq_alloc_tag_set(md
->tag_set
);
930 goto out_kfree_tag_set
;
932 q
= blk_mq_init_allocated_queue(md
->tag_set
, md
->queue
);
937 dm_init_md_queue(md
);
939 /* backfill 'mq' sysfs registration normally done in blk_register_queue */
940 blk_mq_register_disk(md
->disk
);
945 blk_mq_free_tag_set(md
->tag_set
);
952 void dm_mq_cleanup_mapped_device(struct mapped_device
*md
)
955 blk_mq_free_tag_set(md
->tag_set
);
960 module_param(reserved_rq_based_ios
, uint
, S_IRUGO
| S_IWUSR
);
961 MODULE_PARM_DESC(reserved_rq_based_ios
, "Reserved IOs in request-based mempools");
963 module_param(use_blk_mq
, bool, S_IRUGO
| S_IWUSR
);
964 MODULE_PARM_DESC(use_blk_mq
, "Use block multiqueue for request-based DM devices");
966 module_param(dm_mq_nr_hw_queues
, uint
, S_IRUGO
| S_IWUSR
);
967 MODULE_PARM_DESC(dm_mq_nr_hw_queues
, "Number of hardware queues for request-based dm-mq devices");
969 module_param(dm_mq_queue_depth
, uint
, S_IRUGO
| S_IWUSR
);
970 MODULE_PARM_DESC(dm_mq_queue_depth
, "Queue depth for request-based dm-mq devices");