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6
7#include <linux/kernel.h>
8#include <linux/module.h>
9#include <linux/backing-dev.h>
10#include <linux/bio.h>
11#include <linux/blkdev.h>
12#include <linux/kmemleak.h>
13#include <linux/mm.h>
14#include <linux/init.h>
15#include <linux/slab.h>
16#include <linux/workqueue.h>
17#include <linux/smp.h>
18#include <linux/llist.h>
19#include <linux/list_sort.h>
20#include <linux/cpu.h>
21#include <linux/cache.h>
22#include <linux/sched/sysctl.h>
23#include <linux/delay.h>
24#include <linux/crash_dump.h>
25#include <linux/prefetch.h>
26
27#include <trace/events/block.h>
28
29#include <linux/blk-mq.h>
30#include "blk.h"
31#include "blk-mq.h"
32#include "blk-mq-tag.h"
33
34static DEFINE_MUTEX(all_q_mutex);
35static LIST_HEAD(all_q_list);
36
37
38
39
40static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx)
41{
42 return sbitmap_any_bit_set(&hctx->ctx_map);
43}
44
45
46
47
48static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx,
49 struct blk_mq_ctx *ctx)
50{
51 if (!sbitmap_test_bit(&hctx->ctx_map, ctx->index_hw))
52 sbitmap_set_bit(&hctx->ctx_map, ctx->index_hw);
53}
54
55static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx,
56 struct blk_mq_ctx *ctx)
57{
58 sbitmap_clear_bit(&hctx->ctx_map, ctx->index_hw);
59}
60
61void blk_mq_freeze_queue_start(struct request_queue *q)
62{
63 int freeze_depth;
64
65 freeze_depth = atomic_inc_return(&q->mq_freeze_depth);
66 if (freeze_depth == 1) {
67 percpu_ref_kill(&q->q_usage_counter);
68 blk_mq_run_hw_queues(q, false);
69 }
70}
71EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_start);
72
73static void blk_mq_freeze_queue_wait(struct request_queue *q)
74{
75 wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter));
76}
77
78
79
80
81
82void blk_freeze_queue(struct request_queue *q)
83{
84
85
86
87
88
89
90
91 blk_mq_freeze_queue_start(q);
92 blk_mq_freeze_queue_wait(q);
93}
94
95void blk_mq_freeze_queue(struct request_queue *q)
96{
97
98
99
100
101 blk_freeze_queue(q);
102}
103EXPORT_SYMBOL_GPL(blk_mq_freeze_queue);
104
105void blk_mq_unfreeze_queue(struct request_queue *q)
106{
107 int freeze_depth;
108
109 freeze_depth = atomic_dec_return(&q->mq_freeze_depth);
110 WARN_ON_ONCE(freeze_depth < 0);
111 if (!freeze_depth) {
112 percpu_ref_reinit(&q->q_usage_counter);
113 wake_up_all(&q->mq_freeze_wq);
114 }
115}
116EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);
117
118void blk_mq_wake_waiters(struct request_queue *q)
119{
120 struct blk_mq_hw_ctx *hctx;
121 unsigned int i;
122
123 queue_for_each_hw_ctx(q, hctx, i)
124 if (blk_mq_hw_queue_mapped(hctx))
125 blk_mq_tag_wakeup_all(hctx->tags, true);
126
127
128
129
130
131
132 wake_up_all(&q->mq_freeze_wq);
133}
134
135bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx)
136{
137 return blk_mq_has_free_tags(hctx->tags);
138}
139EXPORT_SYMBOL(blk_mq_can_queue);
140
141static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
142 struct request *rq, int op,
143 unsigned int op_flags)
144{
145 if (blk_queue_io_stat(q))
146 op_flags |= REQ_IO_STAT;
147
148 INIT_LIST_HEAD(&rq->queuelist);
149
150 rq->q = q;
151 rq->mq_ctx = ctx;
152 req_set_op_attrs(rq, op, op_flags);
153
154 rq->cpu = -1;
155 INIT_HLIST_NODE(&rq->hash);
156 RB_CLEAR_NODE(&rq->rb_node);
157 rq->rq_disk = NULL;
158 rq->part = NULL;
159 rq->start_time = jiffies;
160#ifdef CONFIG_BLK_CGROUP
161 rq->rl = NULL;
162 set_start_time_ns(rq);
163 rq->io_start_time_ns = 0;
164#endif
165 rq->nr_phys_segments = 0;
166#if defined(CONFIG_BLK_DEV_INTEGRITY)
167 rq->nr_integrity_segments = 0;
168#endif
169 rq->special = NULL;
170
171 rq->errors = 0;
172
173 rq->cmd = rq->__cmd;
174
175 rq->extra_len = 0;
176 rq->sense_len = 0;
177 rq->resid_len = 0;
178 rq->sense = NULL;
179
180 INIT_LIST_HEAD(&rq->timeout_list);
181 rq->timeout = 0;
182
183 rq->end_io = NULL;
184 rq->end_io_data = NULL;
185 rq->next_rq = NULL;
186
187 ctx->rq_dispatched[rw_is_sync(op, op_flags)]++;
188}
189
190static struct request *
191__blk_mq_alloc_request(struct blk_mq_alloc_data *data, int op, int op_flags)
192{
193 struct request *rq;
194 unsigned int tag;
195
196 tag = blk_mq_get_tag(data);
197 if (tag != BLK_MQ_TAG_FAIL) {
198 rq = data->hctx->tags->rqs[tag];
199
200 if (blk_mq_tag_busy(data->hctx)) {
201 rq->cmd_flags = REQ_MQ_INFLIGHT;
202 atomic_inc(&data->hctx->nr_active);
203 }
204
205 rq->tag = tag;
206 blk_mq_rq_ctx_init(data->q, data->ctx, rq, op, op_flags);
207 return rq;
208 }
209
210 return NULL;
211}
212
213struct request *blk_mq_alloc_request(struct request_queue *q, int rw,
214 unsigned int flags)
215{
216 struct blk_mq_ctx *ctx;
217 struct blk_mq_hw_ctx *hctx;
218 struct request *rq;
219 struct blk_mq_alloc_data alloc_data;
220 int ret;
221
222 ret = blk_queue_enter(q, flags & BLK_MQ_REQ_NOWAIT);
223 if (ret)
224 return ERR_PTR(ret);
225
226 ctx = blk_mq_get_ctx(q);
227 hctx = blk_mq_map_queue(q, ctx->cpu);
228 blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx);
229 rq = __blk_mq_alloc_request(&alloc_data, rw, 0);
230 blk_mq_put_ctx(ctx);
231
232 if (!rq) {
233 blk_queue_exit(q);
234 return ERR_PTR(-EWOULDBLOCK);
235 }
236
237 rq->__data_len = 0;
238 rq->__sector = (sector_t) -1;
239 rq->bio = rq->biotail = NULL;
240 return rq;
241}
242EXPORT_SYMBOL(blk_mq_alloc_request);
243
244struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int rw,
245 unsigned int flags, unsigned int hctx_idx)
246{
247 struct blk_mq_hw_ctx *hctx;
248 struct blk_mq_ctx *ctx;
249 struct request *rq;
250 struct blk_mq_alloc_data alloc_data;
251 int ret;
252
253
254
255
256
257
258
259 if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT)))
260 return ERR_PTR(-EINVAL);
261
262 if (hctx_idx >= q->nr_hw_queues)
263 return ERR_PTR(-EIO);
264
265 ret = blk_queue_enter(q, true);
266 if (ret)
267 return ERR_PTR(ret);
268
269
270
271
272
273 hctx = q->queue_hw_ctx[hctx_idx];
274 if (!blk_mq_hw_queue_mapped(hctx)) {
275 ret = -EXDEV;
276 goto out_queue_exit;
277 }
278 ctx = __blk_mq_get_ctx(q, cpumask_first(hctx->cpumask));
279
280 blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx);
281 rq = __blk_mq_alloc_request(&alloc_data, rw, 0);
282 if (!rq) {
283 ret = -EWOULDBLOCK;
284 goto out_queue_exit;
285 }
286
287 return rq;
288
289out_queue_exit:
290 blk_queue_exit(q);
291 return ERR_PTR(ret);
292}
293EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx);
294
295static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx,
296 struct blk_mq_ctx *ctx, struct request *rq)
297{
298 const int tag = rq->tag;
299 struct request_queue *q = rq->q;
300
301 if (rq->cmd_flags & REQ_MQ_INFLIGHT)
302 atomic_dec(&hctx->nr_active);
303 rq->cmd_flags = 0;
304
305 clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
306 blk_mq_put_tag(hctx, ctx, tag);
307 blk_queue_exit(q);
308}
309
310void blk_mq_free_hctx_request(struct blk_mq_hw_ctx *hctx, struct request *rq)
311{
312 struct blk_mq_ctx *ctx = rq->mq_ctx;
313
314 ctx->rq_completed[rq_is_sync(rq)]++;
315 __blk_mq_free_request(hctx, ctx, rq);
316
317}
318EXPORT_SYMBOL_GPL(blk_mq_free_hctx_request);
319
320void blk_mq_free_request(struct request *rq)
321{
322 blk_mq_free_hctx_request(blk_mq_map_queue(rq->q, rq->mq_ctx->cpu), rq);
323}
324EXPORT_SYMBOL_GPL(blk_mq_free_request);
325
326inline void __blk_mq_end_request(struct request *rq, int error)
327{
328 blk_account_io_done(rq);
329
330 if (rq->end_io) {
331 rq->end_io(rq, error);
332 } else {
333 if (unlikely(blk_bidi_rq(rq)))
334 blk_mq_free_request(rq->next_rq);
335 blk_mq_free_request(rq);
336 }
337}
338EXPORT_SYMBOL(__blk_mq_end_request);
339
340void blk_mq_end_request(struct request *rq, int error)
341{
342 if (blk_update_request(rq, error, blk_rq_bytes(rq)))
343 BUG();
344 __blk_mq_end_request(rq, error);
345}
346EXPORT_SYMBOL(blk_mq_end_request);
347
348static void __blk_mq_complete_request_remote(void *data)
349{
350 struct request *rq = data;
351
352 rq->q->softirq_done_fn(rq);
353}
354
355static void blk_mq_ipi_complete_request(struct request *rq)
356{
357 struct blk_mq_ctx *ctx = rq->mq_ctx;
358 bool shared = false;
359 int cpu;
360
361 if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) {
362 rq->q->softirq_done_fn(rq);
363 return;
364 }
365
366 cpu = get_cpu();
367 if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags))
368 shared = cpus_share_cache(cpu, ctx->cpu);
369
370 if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) {
371 rq->csd.func = __blk_mq_complete_request_remote;
372 rq->csd.info = rq;
373 rq->csd.flags = 0;
374 smp_call_function_single_async(ctx->cpu, &rq->csd);
375 } else {
376 rq->q->softirq_done_fn(rq);
377 }
378 put_cpu();
379}
380
381static void __blk_mq_complete_request(struct request *rq)
382{
383 struct request_queue *q = rq->q;
384
385 if (!q->softirq_done_fn)
386 blk_mq_end_request(rq, rq->errors);
387 else
388 blk_mq_ipi_complete_request(rq);
389}
390
391
392
393
394
395
396
397
398
399void blk_mq_complete_request(struct request *rq, int error)
400{
401 struct request_queue *q = rq->q;
402
403 if (unlikely(blk_should_fake_timeout(q)))
404 return;
405 if (!blk_mark_rq_complete(rq)) {
406 rq->errors = error;
407 __blk_mq_complete_request(rq);
408 }
409}
410EXPORT_SYMBOL(blk_mq_complete_request);
411
412int blk_mq_request_started(struct request *rq)
413{
414 return test_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
415}
416EXPORT_SYMBOL_GPL(blk_mq_request_started);
417
418void blk_mq_start_request(struct request *rq)
419{
420 struct request_queue *q = rq->q;
421
422 trace_block_rq_issue(q, rq);
423
424 rq->resid_len = blk_rq_bytes(rq);
425 if (unlikely(blk_bidi_rq(rq)))
426 rq->next_rq->resid_len = blk_rq_bytes(rq->next_rq);
427
428 blk_add_timer(rq);
429
430
431
432
433
434 smp_mb__before_atomic();
435
436
437
438
439
440
441
442 if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
443 set_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
444 if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags))
445 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
446
447 if (q->dma_drain_size && blk_rq_bytes(rq)) {
448
449
450
451
452
453 rq->nr_phys_segments++;
454 }
455}
456EXPORT_SYMBOL(blk_mq_start_request);
457
458static void __blk_mq_requeue_request(struct request *rq)
459{
460 struct request_queue *q = rq->q;
461
462 trace_block_rq_requeue(q, rq);
463
464 if (test_and_clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) {
465 if (q->dma_drain_size && blk_rq_bytes(rq))
466 rq->nr_phys_segments--;
467 }
468}
469
470void blk_mq_requeue_request(struct request *rq)
471{
472 __blk_mq_requeue_request(rq);
473
474 BUG_ON(blk_queued_rq(rq));
475 blk_mq_add_to_requeue_list(rq, true);
476}
477EXPORT_SYMBOL(blk_mq_requeue_request);
478
479static void blk_mq_requeue_work(struct work_struct *work)
480{
481 struct request_queue *q =
482 container_of(work, struct request_queue, requeue_work.work);
483 LIST_HEAD(rq_list);
484 struct request *rq, *next;
485 unsigned long flags;
486
487 spin_lock_irqsave(&q->requeue_lock, flags);
488 list_splice_init(&q->requeue_list, &rq_list);
489 spin_unlock_irqrestore(&q->requeue_lock, flags);
490
491 list_for_each_entry_safe(rq, next, &rq_list, queuelist) {
492 if (!(rq->cmd_flags & REQ_SOFTBARRIER))
493 continue;
494
495 rq->cmd_flags &= ~REQ_SOFTBARRIER;
496 list_del_init(&rq->queuelist);
497 blk_mq_insert_request(rq, true, false, false);
498 }
499
500 while (!list_empty(&rq_list)) {
501 rq = list_entry(rq_list.next, struct request, queuelist);
502 list_del_init(&rq->queuelist);
503 blk_mq_insert_request(rq, false, false, false);
504 }
505
506
507
508
509
510 blk_mq_start_hw_queues(q);
511}
512
513void blk_mq_add_to_requeue_list(struct request *rq, bool at_head)
514{
515 struct request_queue *q = rq->q;
516 unsigned long flags;
517
518
519
520
521
522 BUG_ON(rq->cmd_flags & REQ_SOFTBARRIER);
523
524 spin_lock_irqsave(&q->requeue_lock, flags);
525 if (at_head) {
526 rq->cmd_flags |= REQ_SOFTBARRIER;
527 list_add(&rq->queuelist, &q->requeue_list);
528 } else {
529 list_add_tail(&rq->queuelist, &q->requeue_list);
530 }
531 spin_unlock_irqrestore(&q->requeue_lock, flags);
532}
533EXPORT_SYMBOL(blk_mq_add_to_requeue_list);
534
535void blk_mq_cancel_requeue_work(struct request_queue *q)
536{
537 cancel_delayed_work_sync(&q->requeue_work);
538}
539EXPORT_SYMBOL_GPL(blk_mq_cancel_requeue_work);
540
541void blk_mq_kick_requeue_list(struct request_queue *q)
542{
543 kblockd_schedule_delayed_work(&q->requeue_work, 0);
544}
545EXPORT_SYMBOL(blk_mq_kick_requeue_list);
546
547void blk_mq_delay_kick_requeue_list(struct request_queue *q,
548 unsigned long msecs)
549{
550 kblockd_schedule_delayed_work(&q->requeue_work,
551 msecs_to_jiffies(msecs));
552}
553EXPORT_SYMBOL(blk_mq_delay_kick_requeue_list);
554
555void blk_mq_abort_requeue_list(struct request_queue *q)
556{
557 unsigned long flags;
558 LIST_HEAD(rq_list);
559
560 spin_lock_irqsave(&q->requeue_lock, flags);
561 list_splice_init(&q->requeue_list, &rq_list);
562 spin_unlock_irqrestore(&q->requeue_lock, flags);
563
564 while (!list_empty(&rq_list)) {
565 struct request *rq;
566
567 rq = list_first_entry(&rq_list, struct request, queuelist);
568 list_del_init(&rq->queuelist);
569 rq->errors = -EIO;
570 blk_mq_end_request(rq, rq->errors);
571 }
572}
573EXPORT_SYMBOL(blk_mq_abort_requeue_list);
574
575struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag)
576{
577 if (tag < tags->nr_tags) {
578 prefetch(tags->rqs[tag]);
579 return tags->rqs[tag];
580 }
581
582 return NULL;
583}
584EXPORT_SYMBOL(blk_mq_tag_to_rq);
585
586struct blk_mq_timeout_data {
587 unsigned long next;
588 unsigned int next_set;
589};
590
591void blk_mq_rq_timed_out(struct request *req, bool reserved)
592{
593 struct blk_mq_ops *ops = req->q->mq_ops;
594 enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER;
595
596
597
598
599
600
601
602
603
604
605 if (!test_bit(REQ_ATOM_STARTED, &req->atomic_flags))
606 return;
607
608 if (ops->timeout)
609 ret = ops->timeout(req, reserved);
610
611 switch (ret) {
612 case BLK_EH_HANDLED:
613 __blk_mq_complete_request(req);
614 break;
615 case BLK_EH_RESET_TIMER:
616 blk_add_timer(req);
617 blk_clear_rq_complete(req);
618 break;
619 case BLK_EH_NOT_HANDLED:
620 break;
621 default:
622 printk(KERN_ERR "block: bad eh return: %d\n", ret);
623 break;
624 }
625}
626
627static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
628 struct request *rq, void *priv, bool reserved)
629{
630 struct blk_mq_timeout_data *data = priv;
631
632 if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) {
633
634
635
636
637 if (unlikely(blk_queue_dying(rq->q))) {
638 rq->errors = -EIO;
639 blk_mq_end_request(rq, rq->errors);
640 }
641 return;
642 }
643
644 if (time_after_eq(jiffies, rq->deadline)) {
645 if (!blk_mark_rq_complete(rq))
646 blk_mq_rq_timed_out(rq, reserved);
647 } else if (!data->next_set || time_after(data->next, rq->deadline)) {
648 data->next = rq->deadline;
649 data->next_set = 1;
650 }
651}
652
653static void blk_mq_timeout_work(struct work_struct *work)
654{
655 struct request_queue *q =
656 container_of(work, struct request_queue, timeout_work);
657 struct blk_mq_timeout_data data = {
658 .next = 0,
659 .next_set = 0,
660 };
661 int i;
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676 if (!percpu_ref_tryget(&q->q_usage_counter))
677 return;
678
679 blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &data);
680
681 if (data.next_set) {
682 data.next = blk_rq_timeout(round_jiffies_up(data.next));
683 mod_timer(&q->timeout, data.next);
684 } else {
685 struct blk_mq_hw_ctx *hctx;
686
687 queue_for_each_hw_ctx(q, hctx, i) {
688
689 if (blk_mq_hw_queue_mapped(hctx))
690 blk_mq_tag_idle(hctx);
691 }
692 }
693 blk_queue_exit(q);
694}
695
696
697
698
699
700
701static bool blk_mq_attempt_merge(struct request_queue *q,
702 struct blk_mq_ctx *ctx, struct bio *bio)
703{
704 struct request *rq;
705 int checked = 8;
706
707 list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) {
708 int el_ret;
709
710 if (!checked--)
711 break;
712
713 if (!blk_rq_merge_ok(rq, bio))
714 continue;
715
716 el_ret = blk_try_merge(rq, bio);
717 if (el_ret == ELEVATOR_BACK_MERGE) {
718 if (bio_attempt_back_merge(q, rq, bio)) {
719 ctx->rq_merged++;
720 return true;
721 }
722 break;
723 } else if (el_ret == ELEVATOR_FRONT_MERGE) {
724 if (bio_attempt_front_merge(q, rq, bio)) {
725 ctx->rq_merged++;
726 return true;
727 }
728 break;
729 }
730 }
731
732 return false;
733}
734
735struct flush_busy_ctx_data {
736 struct blk_mq_hw_ctx *hctx;
737 struct list_head *list;
738};
739
740static bool flush_busy_ctx(struct sbitmap *sb, unsigned int bitnr, void *data)
741{
742 struct flush_busy_ctx_data *flush_data = data;
743 struct blk_mq_hw_ctx *hctx = flush_data->hctx;
744 struct blk_mq_ctx *ctx = hctx->ctxs[bitnr];
745
746 sbitmap_clear_bit(sb, bitnr);
747 spin_lock(&ctx->lock);
748 list_splice_tail_init(&ctx->rq_list, flush_data->list);
749 spin_unlock(&ctx->lock);
750 return true;
751}
752
753
754
755
756
757static void flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list)
758{
759 struct flush_busy_ctx_data data = {
760 .hctx = hctx,
761 .list = list,
762 };
763
764 sbitmap_for_each_set(&hctx->ctx_map, flush_busy_ctx, &data);
765}
766
767static inline unsigned int queued_to_index(unsigned int queued)
768{
769 if (!queued)
770 return 0;
771
772 return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1);
773}
774
775
776
777
778
779
780
781static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
782{
783 struct request_queue *q = hctx->queue;
784 struct request *rq;
785 LIST_HEAD(rq_list);
786 LIST_HEAD(driver_list);
787 struct list_head *dptr;
788 int queued;
789
790 if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state)))
791 return;
792
793 WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) &&
794 cpu_online(hctx->next_cpu));
795
796 hctx->run++;
797
798
799
800
801 flush_busy_ctxs(hctx, &rq_list);
802
803
804
805
806
807 if (!list_empty_careful(&hctx->dispatch)) {
808 spin_lock(&hctx->lock);
809 if (!list_empty(&hctx->dispatch))
810 list_splice_init(&hctx->dispatch, &rq_list);
811 spin_unlock(&hctx->lock);
812 }
813
814
815
816
817
818 dptr = NULL;
819
820
821
822
823 queued = 0;
824 while (!list_empty(&rq_list)) {
825 struct blk_mq_queue_data bd;
826 int ret;
827
828 rq = list_first_entry(&rq_list, struct request, queuelist);
829 list_del_init(&rq->queuelist);
830
831 bd.rq = rq;
832 bd.list = dptr;
833 bd.last = list_empty(&rq_list);
834
835 ret = q->mq_ops->queue_rq(hctx, &bd);
836 switch (ret) {
837 case BLK_MQ_RQ_QUEUE_OK:
838 queued++;
839 break;
840 case BLK_MQ_RQ_QUEUE_BUSY:
841 list_add(&rq->queuelist, &rq_list);
842 __blk_mq_requeue_request(rq);
843 break;
844 default:
845 pr_err("blk-mq: bad return on queue: %d\n", ret);
846 case BLK_MQ_RQ_QUEUE_ERROR:
847 rq->errors = -EIO;
848 blk_mq_end_request(rq, rq->errors);
849 break;
850 }
851
852 if (ret == BLK_MQ_RQ_QUEUE_BUSY)
853 break;
854
855
856
857
858
859 if (!dptr && rq_list.next != rq_list.prev)
860 dptr = &driver_list;
861 }
862
863 hctx->dispatched[queued_to_index(queued)]++;
864
865
866
867
868
869 if (!list_empty(&rq_list)) {
870 spin_lock(&hctx->lock);
871 list_splice(&rq_list, &hctx->dispatch);
872 spin_unlock(&hctx->lock);
873
874
875
876
877
878
879
880
881
882 blk_mq_run_hw_queue(hctx, true);
883 }
884}
885
886
887
888
889
890
891
892static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx)
893{
894 if (hctx->queue->nr_hw_queues == 1)
895 return WORK_CPU_UNBOUND;
896
897 if (--hctx->next_cpu_batch <= 0) {
898 int cpu = hctx->next_cpu, next_cpu;
899
900 next_cpu = cpumask_next(hctx->next_cpu, hctx->cpumask);
901 if (next_cpu >= nr_cpu_ids)
902 next_cpu = cpumask_first(hctx->cpumask);
903
904 hctx->next_cpu = next_cpu;
905 hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
906
907 return cpu;
908 }
909
910 return hctx->next_cpu;
911}
912
913void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
914{
915 if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state) ||
916 !blk_mq_hw_queue_mapped(hctx)))
917 return;
918
919 if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) {
920 int cpu = get_cpu();
921 if (cpumask_test_cpu(cpu, hctx->cpumask)) {
922 __blk_mq_run_hw_queue(hctx);
923 put_cpu();
924 return;
925 }
926
927 put_cpu();
928 }
929
930 kblockd_schedule_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work);
931}
932
933void blk_mq_run_hw_queues(struct request_queue *q, bool async)
934{
935 struct blk_mq_hw_ctx *hctx;
936 int i;
937
938 queue_for_each_hw_ctx(q, hctx, i) {
939 if ((!blk_mq_hctx_has_pending(hctx) &&
940 list_empty_careful(&hctx->dispatch)) ||
941 test_bit(BLK_MQ_S_STOPPED, &hctx->state))
942 continue;
943
944 blk_mq_run_hw_queue(hctx, async);
945 }
946}
947EXPORT_SYMBOL(blk_mq_run_hw_queues);
948
949void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx)
950{
951 cancel_work(&hctx->run_work);
952 cancel_delayed_work(&hctx->delay_work);
953 set_bit(BLK_MQ_S_STOPPED, &hctx->state);
954}
955EXPORT_SYMBOL(blk_mq_stop_hw_queue);
956
957void blk_mq_stop_hw_queues(struct request_queue *q)
958{
959 struct blk_mq_hw_ctx *hctx;
960 int i;
961
962 queue_for_each_hw_ctx(q, hctx, i)
963 blk_mq_stop_hw_queue(hctx);
964}
965EXPORT_SYMBOL(blk_mq_stop_hw_queues);
966
967void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx)
968{
969 clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
970
971 blk_mq_run_hw_queue(hctx, false);
972}
973EXPORT_SYMBOL(blk_mq_start_hw_queue);
974
975void blk_mq_start_hw_queues(struct request_queue *q)
976{
977 struct blk_mq_hw_ctx *hctx;
978 int i;
979
980 queue_for_each_hw_ctx(q, hctx, i)
981 blk_mq_start_hw_queue(hctx);
982}
983EXPORT_SYMBOL(blk_mq_start_hw_queues);
984
985void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async)
986{
987 struct blk_mq_hw_ctx *hctx;
988 int i;
989
990 queue_for_each_hw_ctx(q, hctx, i) {
991 if (!test_bit(BLK_MQ_S_STOPPED, &hctx->state))
992 continue;
993
994 clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
995 blk_mq_run_hw_queue(hctx, async);
996 }
997}
998EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues);
999
1000static void blk_mq_run_work_fn(struct work_struct *work)
1001{
1002 struct blk_mq_hw_ctx *hctx;
1003
1004 hctx = container_of(work, struct blk_mq_hw_ctx, run_work);
1005
1006 __blk_mq_run_hw_queue(hctx);
1007}
1008
1009static void blk_mq_delay_work_fn(struct work_struct *work)
1010{
1011 struct blk_mq_hw_ctx *hctx;
1012
1013 hctx = container_of(work, struct blk_mq_hw_ctx, delay_work.work);
1014
1015 if (test_and_clear_bit(BLK_MQ_S_STOPPED, &hctx->state))
1016 __blk_mq_run_hw_queue(hctx);
1017}
1018
1019void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs)
1020{
1021 if (unlikely(!blk_mq_hw_queue_mapped(hctx)))
1022 return;
1023
1024 kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx),
1025 &hctx->delay_work, msecs_to_jiffies(msecs));
1026}
1027EXPORT_SYMBOL(blk_mq_delay_queue);
1028
1029static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx,
1030 struct request *rq,
1031 bool at_head)
1032{
1033 struct blk_mq_ctx *ctx = rq->mq_ctx;
1034
1035 trace_block_rq_insert(hctx->queue, rq);
1036
1037 if (at_head)
1038 list_add(&rq->queuelist, &ctx->rq_list);
1039 else
1040 list_add_tail(&rq->queuelist, &ctx->rq_list);
1041}
1042
1043static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx,
1044 struct request *rq, bool at_head)
1045{
1046 struct blk_mq_ctx *ctx = rq->mq_ctx;
1047
1048 __blk_mq_insert_req_list(hctx, rq, at_head);
1049 blk_mq_hctx_mark_pending(hctx, ctx);
1050}
1051
1052void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue,
1053 bool async)
1054{
1055 struct blk_mq_ctx *ctx = rq->mq_ctx;
1056 struct request_queue *q = rq->q;
1057 struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu);
1058
1059 spin_lock(&ctx->lock);
1060 __blk_mq_insert_request(hctx, rq, at_head);
1061 spin_unlock(&ctx->lock);
1062
1063 if (run_queue)
1064 blk_mq_run_hw_queue(hctx, async);
1065}
1066
1067static void blk_mq_insert_requests(struct request_queue *q,
1068 struct blk_mq_ctx *ctx,
1069 struct list_head *list,
1070 int depth,
1071 bool from_schedule)
1072
1073{
1074 struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu);
1075
1076 trace_block_unplug(q, depth, !from_schedule);
1077
1078
1079
1080
1081
1082 spin_lock(&ctx->lock);
1083 while (!list_empty(list)) {
1084 struct request *rq;
1085
1086 rq = list_first_entry(list, struct request, queuelist);
1087 BUG_ON(rq->mq_ctx != ctx);
1088 list_del_init(&rq->queuelist);
1089 __blk_mq_insert_req_list(hctx, rq, false);
1090 }
1091 blk_mq_hctx_mark_pending(hctx, ctx);
1092 spin_unlock(&ctx->lock);
1093
1094 blk_mq_run_hw_queue(hctx, from_schedule);
1095}
1096
1097static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b)
1098{
1099 struct request *rqa = container_of(a, struct request, queuelist);
1100 struct request *rqb = container_of(b, struct request, queuelist);
1101
1102 return !(rqa->mq_ctx < rqb->mq_ctx ||
1103 (rqa->mq_ctx == rqb->mq_ctx &&
1104 blk_rq_pos(rqa) < blk_rq_pos(rqb)));
1105}
1106
1107void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
1108{
1109 struct blk_mq_ctx *this_ctx;
1110 struct request_queue *this_q;
1111 struct request *rq;
1112 LIST_HEAD(list);
1113 LIST_HEAD(ctx_list);
1114 unsigned int depth;
1115
1116 list_splice_init(&plug->mq_list, &list);
1117
1118 list_sort(NULL, &list, plug_ctx_cmp);
1119
1120 this_q = NULL;
1121 this_ctx = NULL;
1122 depth = 0;
1123
1124 while (!list_empty(&list)) {
1125 rq = list_entry_rq(list.next);
1126 list_del_init(&rq->queuelist);
1127 BUG_ON(!rq->q);
1128 if (rq->mq_ctx != this_ctx) {
1129 if (this_ctx) {
1130 blk_mq_insert_requests(this_q, this_ctx,
1131 &ctx_list, depth,
1132 from_schedule);
1133 }
1134
1135 this_ctx = rq->mq_ctx;
1136 this_q = rq->q;
1137 depth = 0;
1138 }
1139
1140 depth++;
1141 list_add_tail(&rq->queuelist, &ctx_list);
1142 }
1143
1144
1145
1146
1147
1148 if (this_ctx) {
1149 blk_mq_insert_requests(this_q, this_ctx, &ctx_list, depth,
1150 from_schedule);
1151 }
1152}
1153
1154static void blk_mq_bio_to_request(struct request *rq, struct bio *bio)
1155{
1156 init_request_from_bio(rq, bio);
1157
1158 blk_account_io_start(rq, 1);
1159}
1160
1161static inline bool hctx_allow_merges(struct blk_mq_hw_ctx *hctx)
1162{
1163 return (hctx->flags & BLK_MQ_F_SHOULD_MERGE) &&
1164 !blk_queue_nomerges(hctx->queue);
1165}
1166
1167static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx,
1168 struct blk_mq_ctx *ctx,
1169 struct request *rq, struct bio *bio)
1170{
1171 if (!hctx_allow_merges(hctx) || !bio_mergeable(bio)) {
1172 blk_mq_bio_to_request(rq, bio);
1173 spin_lock(&ctx->lock);
1174insert_rq:
1175 __blk_mq_insert_request(hctx, rq, false);
1176 spin_unlock(&ctx->lock);
1177 return false;
1178 } else {
1179 struct request_queue *q = hctx->queue;
1180
1181 spin_lock(&ctx->lock);
1182 if (!blk_mq_attempt_merge(q, ctx, bio)) {
1183 blk_mq_bio_to_request(rq, bio);
1184 goto insert_rq;
1185 }
1186
1187 spin_unlock(&ctx->lock);
1188 __blk_mq_free_request(hctx, ctx, rq);
1189 return true;
1190 }
1191}
1192
1193struct blk_map_ctx {
1194 struct blk_mq_hw_ctx *hctx;
1195 struct blk_mq_ctx *ctx;
1196};
1197
1198static struct request *blk_mq_map_request(struct request_queue *q,
1199 struct bio *bio,
1200 struct blk_map_ctx *data)
1201{
1202 struct blk_mq_hw_ctx *hctx;
1203 struct blk_mq_ctx *ctx;
1204 struct request *rq;
1205 int op = bio_data_dir(bio);
1206 int op_flags = 0;
1207 struct blk_mq_alloc_data alloc_data;
1208
1209 blk_queue_enter_live(q);
1210 ctx = blk_mq_get_ctx(q);
1211 hctx = blk_mq_map_queue(q, ctx->cpu);
1212
1213 if (rw_is_sync(bio_op(bio), bio->bi_opf))
1214 op_flags |= REQ_SYNC;
1215
1216 trace_block_getrq(q, bio, op);
1217 blk_mq_set_alloc_data(&alloc_data, q, 0, ctx, hctx);
1218 rq = __blk_mq_alloc_request(&alloc_data, op, op_flags);
1219
1220 data->hctx = alloc_data.hctx;
1221 data->ctx = alloc_data.ctx;
1222 data->hctx->queued++;
1223 return rq;
1224}
1225
1226static int blk_mq_direct_issue_request(struct request *rq, blk_qc_t *cookie)
1227{
1228 int ret;
1229 struct request_queue *q = rq->q;
1230 struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, rq->mq_ctx->cpu);
1231 struct blk_mq_queue_data bd = {
1232 .rq = rq,
1233 .list = NULL,
1234 .last = 1
1235 };
1236 blk_qc_t new_cookie = blk_tag_to_qc_t(rq->tag, hctx->queue_num);
1237
1238
1239
1240
1241
1242
1243 ret = q->mq_ops->queue_rq(hctx, &bd);
1244 if (ret == BLK_MQ_RQ_QUEUE_OK) {
1245 *cookie = new_cookie;
1246 return 0;
1247 }
1248
1249 __blk_mq_requeue_request(rq);
1250
1251 if (ret == BLK_MQ_RQ_QUEUE_ERROR) {
1252 *cookie = BLK_QC_T_NONE;
1253 rq->errors = -EIO;
1254 blk_mq_end_request(rq, rq->errors);
1255 return 0;
1256 }
1257
1258 return -1;
1259}
1260
1261
1262
1263
1264
1265
1266static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
1267{
1268 const int is_sync = rw_is_sync(bio_op(bio), bio->bi_opf);
1269 const int is_flush_fua = bio->bi_opf & (REQ_PREFLUSH | REQ_FUA);
1270 struct blk_map_ctx data;
1271 struct request *rq;
1272 unsigned int request_count = 0;
1273 struct blk_plug *plug;
1274 struct request *same_queue_rq = NULL;
1275 blk_qc_t cookie;
1276
1277 blk_queue_bounce(q, &bio);
1278
1279 if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
1280 bio_io_error(bio);
1281 return BLK_QC_T_NONE;
1282 }
1283
1284 blk_queue_split(q, &bio, q->bio_split);
1285
1286 if (!is_flush_fua && !blk_queue_nomerges(q) &&
1287 blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq))
1288 return BLK_QC_T_NONE;
1289
1290 rq = blk_mq_map_request(q, bio, &data);
1291 if (unlikely(!rq))
1292 return BLK_QC_T_NONE;
1293
1294 cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num);
1295
1296 if (unlikely(is_flush_fua)) {
1297 blk_mq_bio_to_request(rq, bio);
1298 blk_insert_flush(rq);
1299 goto run_queue;
1300 }
1301
1302 plug = current->plug;
1303
1304
1305
1306
1307
1308 if (((plug && !blk_queue_nomerges(q)) || is_sync) &&
1309 !(data.hctx->flags & BLK_MQ_F_DEFER_ISSUE)) {
1310 struct request *old_rq = NULL;
1311
1312 blk_mq_bio_to_request(rq, bio);
1313
1314
1315
1316
1317
1318
1319 if (plug) {
1320
1321
1322
1323
1324
1325 if (same_queue_rq && !list_empty(&plug->mq_list)) {
1326 old_rq = same_queue_rq;
1327 list_del_init(&old_rq->queuelist);
1328 }
1329 list_add_tail(&rq->queuelist, &plug->mq_list);
1330 } else
1331 old_rq = rq;
1332 blk_mq_put_ctx(data.ctx);
1333 if (!old_rq)
1334 goto done;
1335 if (!blk_mq_direct_issue_request(old_rq, &cookie))
1336 goto done;
1337 blk_mq_insert_request(old_rq, false, true, true);
1338 goto done;
1339 }
1340
1341 if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) {
1342
1343
1344
1345
1346
1347
1348run_queue:
1349 blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua);
1350 }
1351 blk_mq_put_ctx(data.ctx);
1352done:
1353 return cookie;
1354}
1355
1356
1357
1358
1359
1360static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio)
1361{
1362 const int is_sync = rw_is_sync(bio_op(bio), bio->bi_opf);
1363 const int is_flush_fua = bio->bi_opf & (REQ_PREFLUSH | REQ_FUA);
1364 struct blk_plug *plug;
1365 unsigned int request_count = 0;
1366 struct blk_map_ctx data;
1367 struct request *rq;
1368 blk_qc_t cookie;
1369
1370 blk_queue_bounce(q, &bio);
1371
1372 if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
1373 bio_io_error(bio);
1374 return BLK_QC_T_NONE;
1375 }
1376
1377 blk_queue_split(q, &bio, q->bio_split);
1378
1379 if (!is_flush_fua && !blk_queue_nomerges(q)) {
1380 if (blk_attempt_plug_merge(q, bio, &request_count, NULL))
1381 return BLK_QC_T_NONE;
1382 } else
1383 request_count = blk_plug_queued_count(q);
1384
1385 rq = blk_mq_map_request(q, bio, &data);
1386 if (unlikely(!rq))
1387 return BLK_QC_T_NONE;
1388
1389 cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num);
1390
1391 if (unlikely(is_flush_fua)) {
1392 blk_mq_bio_to_request(rq, bio);
1393 blk_insert_flush(rq);
1394 goto run_queue;
1395 }
1396
1397
1398
1399
1400
1401
1402 plug = current->plug;
1403 if (plug) {
1404 blk_mq_bio_to_request(rq, bio);
1405 if (!request_count)
1406 trace_block_plug(q);
1407
1408 blk_mq_put_ctx(data.ctx);
1409
1410 if (request_count >= BLK_MAX_REQUEST_COUNT) {
1411 blk_flush_plug_list(plug, false);
1412 trace_block_plug(q);
1413 }
1414
1415 list_add_tail(&rq->queuelist, &plug->mq_list);
1416 return cookie;
1417 }
1418
1419 if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) {
1420
1421
1422
1423
1424
1425
1426run_queue:
1427 blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua);
1428 }
1429
1430 blk_mq_put_ctx(data.ctx);
1431 return cookie;
1432}
1433
1434static void blk_mq_free_rq_map(struct blk_mq_tag_set *set,
1435 struct blk_mq_tags *tags, unsigned int hctx_idx)
1436{
1437 struct page *page;
1438
1439 if (tags->rqs && set->ops->exit_request) {
1440 int i;
1441
1442 for (i = 0; i < tags->nr_tags; i++) {
1443 if (!tags->rqs[i])
1444 continue;
1445 set->ops->exit_request(set->driver_data, tags->rqs[i],
1446 hctx_idx, i);
1447 tags->rqs[i] = NULL;
1448 }
1449 }
1450
1451 while (!list_empty(&tags->page_list)) {
1452 page = list_first_entry(&tags->page_list, struct page, lru);
1453 list_del_init(&page->lru);
1454
1455
1456
1457
1458 kmemleak_free(page_address(page));
1459 __free_pages(page, page->private);
1460 }
1461
1462 kfree(tags->rqs);
1463
1464 blk_mq_free_tags(tags);
1465}
1466
1467static size_t order_to_size(unsigned int order)
1468{
1469 return (size_t)PAGE_SIZE << order;
1470}
1471
1472static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,
1473 unsigned int hctx_idx)
1474{
1475 struct blk_mq_tags *tags;
1476 unsigned int i, j, entries_per_page, max_order = 4;
1477 size_t rq_size, left;
1478
1479 tags = blk_mq_init_tags(set->queue_depth, set->reserved_tags,
1480 set->numa_node,
1481 BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags));
1482 if (!tags)
1483 return NULL;
1484
1485 INIT_LIST_HEAD(&tags->page_list);
1486
1487 tags->rqs = kzalloc_node(set->queue_depth * sizeof(struct request *),
1488 GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY,
1489 set->numa_node);
1490 if (!tags->rqs) {
1491 blk_mq_free_tags(tags);
1492 return NULL;
1493 }
1494
1495
1496
1497
1498
1499 rq_size = round_up(sizeof(struct request) + set->cmd_size,
1500 cache_line_size());
1501 left = rq_size * set->queue_depth;
1502
1503 for (i = 0; i < set->queue_depth; ) {
1504 int this_order = max_order;
1505 struct page *page;
1506 int to_do;
1507 void *p;
1508
1509 while (this_order && left < order_to_size(this_order - 1))
1510 this_order--;
1511
1512 do {
1513 page = alloc_pages_node(set->numa_node,
1514 GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO,
1515 this_order);
1516 if (page)
1517 break;
1518 if (!this_order--)
1519 break;
1520 if (order_to_size(this_order) < rq_size)
1521 break;
1522 } while (1);
1523
1524 if (!page)
1525 goto fail;
1526
1527 page->private = this_order;
1528 list_add_tail(&page->lru, &tags->page_list);
1529
1530 p = page_address(page);
1531
1532
1533
1534
1535 kmemleak_alloc(p, order_to_size(this_order), 1, GFP_KERNEL);
1536 entries_per_page = order_to_size(this_order) / rq_size;
1537 to_do = min(entries_per_page, set->queue_depth - i);
1538 left -= to_do * rq_size;
1539 for (j = 0; j < to_do; j++) {
1540 tags->rqs[i] = p;
1541 if (set->ops->init_request) {
1542 if (set->ops->init_request(set->driver_data,
1543 tags->rqs[i], hctx_idx, i,
1544 set->numa_node)) {
1545 tags->rqs[i] = NULL;
1546 goto fail;
1547 }
1548 }
1549
1550 p += rq_size;
1551 i++;
1552 }
1553 }
1554 return tags;
1555
1556fail:
1557 blk_mq_free_rq_map(set, tags, hctx_idx);
1558 return NULL;
1559}
1560
1561
1562
1563
1564
1565
1566static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node)
1567{
1568 struct blk_mq_hw_ctx *hctx;
1569 struct blk_mq_ctx *ctx;
1570 LIST_HEAD(tmp);
1571
1572 hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_dead);
1573 ctx = __blk_mq_get_ctx(hctx->queue, cpu);
1574
1575 spin_lock(&ctx->lock);
1576 if (!list_empty(&ctx->rq_list)) {
1577 list_splice_init(&ctx->rq_list, &tmp);
1578 blk_mq_hctx_clear_pending(hctx, ctx);
1579 }
1580 spin_unlock(&ctx->lock);
1581
1582 if (list_empty(&tmp))
1583 return 0;
1584
1585 spin_lock(&hctx->lock);
1586 list_splice_tail_init(&tmp, &hctx->dispatch);
1587 spin_unlock(&hctx->lock);
1588
1589 blk_mq_run_hw_queue(hctx, true);
1590 return 0;
1591}
1592
1593static void blk_mq_remove_cpuhp(struct blk_mq_hw_ctx *hctx)
1594{
1595 cpuhp_state_remove_instance_nocalls(CPUHP_BLK_MQ_DEAD,
1596 &hctx->cpuhp_dead);
1597}
1598
1599
1600static void blk_mq_exit_hctx(struct request_queue *q,
1601 struct blk_mq_tag_set *set,
1602 struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
1603{
1604 unsigned flush_start_tag = set->queue_depth;
1605
1606 blk_mq_tag_idle(hctx);
1607
1608 if (set->ops->exit_request)
1609 set->ops->exit_request(set->driver_data,
1610 hctx->fq->flush_rq, hctx_idx,
1611 flush_start_tag + hctx_idx);
1612
1613 if (set->ops->exit_hctx)
1614 set->ops->exit_hctx(hctx, hctx_idx);
1615
1616 blk_mq_remove_cpuhp(hctx);
1617 blk_free_flush_queue(hctx->fq);
1618 sbitmap_free(&hctx->ctx_map);
1619}
1620
1621static void blk_mq_exit_hw_queues(struct request_queue *q,
1622 struct blk_mq_tag_set *set, int nr_queue)
1623{
1624 struct blk_mq_hw_ctx *hctx;
1625 unsigned int i;
1626
1627 queue_for_each_hw_ctx(q, hctx, i) {
1628 if (i == nr_queue)
1629 break;
1630 blk_mq_exit_hctx(q, set, hctx, i);
1631 }
1632}
1633
1634static void blk_mq_free_hw_queues(struct request_queue *q,
1635 struct blk_mq_tag_set *set)
1636{
1637 struct blk_mq_hw_ctx *hctx;
1638 unsigned int i;
1639
1640 queue_for_each_hw_ctx(q, hctx, i)
1641 free_cpumask_var(hctx->cpumask);
1642}
1643
1644static int blk_mq_init_hctx(struct request_queue *q,
1645 struct blk_mq_tag_set *set,
1646 struct blk_mq_hw_ctx *hctx, unsigned hctx_idx)
1647{
1648 int node;
1649 unsigned flush_start_tag = set->queue_depth;
1650
1651 node = hctx->numa_node;
1652 if (node == NUMA_NO_NODE)
1653 node = hctx->numa_node = set->numa_node;
1654
1655 INIT_WORK(&hctx->run_work, blk_mq_run_work_fn);
1656 INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn);
1657 spin_lock_init(&hctx->lock);
1658 INIT_LIST_HEAD(&hctx->dispatch);
1659 hctx->queue = q;
1660 hctx->queue_num = hctx_idx;
1661 hctx->flags = set->flags & ~BLK_MQ_F_TAG_SHARED;
1662
1663 cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, &hctx->cpuhp_dead);
1664
1665 hctx->tags = set->tags[hctx_idx];
1666
1667
1668
1669
1670
1671 hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *),
1672 GFP_KERNEL, node);
1673 if (!hctx->ctxs)
1674 goto unregister_cpu_notifier;
1675
1676 if (sbitmap_init_node(&hctx->ctx_map, nr_cpu_ids, ilog2(8), GFP_KERNEL,
1677 node))
1678 goto free_ctxs;
1679
1680 hctx->nr_ctx = 0;
1681
1682 if (set->ops->init_hctx &&
1683 set->ops->init_hctx(hctx, set->driver_data, hctx_idx))
1684 goto free_bitmap;
1685
1686 hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size);
1687 if (!hctx->fq)
1688 goto exit_hctx;
1689
1690 if (set->ops->init_request &&
1691 set->ops->init_request(set->driver_data,
1692 hctx->fq->flush_rq, hctx_idx,
1693 flush_start_tag + hctx_idx, node))
1694 goto free_fq;
1695
1696 return 0;
1697
1698 free_fq:
1699 kfree(hctx->fq);
1700 exit_hctx:
1701 if (set->ops->exit_hctx)
1702 set->ops->exit_hctx(hctx, hctx_idx);
1703 free_bitmap:
1704 sbitmap_free(&hctx->ctx_map);
1705 free_ctxs:
1706 kfree(hctx->ctxs);
1707 unregister_cpu_notifier:
1708 blk_mq_remove_cpuhp(hctx);
1709 return -1;
1710}
1711
1712static void blk_mq_init_cpu_queues(struct request_queue *q,
1713 unsigned int nr_hw_queues)
1714{
1715 unsigned int i;
1716
1717 for_each_possible_cpu(i) {
1718 struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i);
1719 struct blk_mq_hw_ctx *hctx;
1720
1721 memset(__ctx, 0, sizeof(*__ctx));
1722 __ctx->cpu = i;
1723 spin_lock_init(&__ctx->lock);
1724 INIT_LIST_HEAD(&__ctx->rq_list);
1725 __ctx->queue = q;
1726
1727
1728 if (!cpu_online(i))
1729 continue;
1730
1731 hctx = blk_mq_map_queue(q, i);
1732
1733
1734
1735
1736
1737 if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE)
1738 hctx->numa_node = local_memory_node(cpu_to_node(i));
1739 }
1740}
1741
1742static void blk_mq_map_swqueue(struct request_queue *q,
1743 const struct cpumask *online_mask)
1744{
1745 unsigned int i;
1746 struct blk_mq_hw_ctx *hctx;
1747 struct blk_mq_ctx *ctx;
1748 struct blk_mq_tag_set *set = q->tag_set;
1749
1750
1751
1752
1753 mutex_lock(&q->sysfs_lock);
1754
1755 queue_for_each_hw_ctx(q, hctx, i) {
1756 cpumask_clear(hctx->cpumask);
1757 hctx->nr_ctx = 0;
1758 }
1759
1760
1761
1762
1763 for_each_possible_cpu(i) {
1764
1765 if (!cpumask_test_cpu(i, online_mask))
1766 continue;
1767
1768 ctx = per_cpu_ptr(q->queue_ctx, i);
1769 hctx = blk_mq_map_queue(q, i);
1770
1771 cpumask_set_cpu(i, hctx->cpumask);
1772 ctx->index_hw = hctx->nr_ctx;
1773 hctx->ctxs[hctx->nr_ctx++] = ctx;
1774 }
1775
1776 mutex_unlock(&q->sysfs_lock);
1777
1778 queue_for_each_hw_ctx(q, hctx, i) {
1779
1780
1781
1782
1783 if (!hctx->nr_ctx) {
1784 if (set->tags[i]) {
1785 blk_mq_free_rq_map(set, set->tags[i], i);
1786 set->tags[i] = NULL;
1787 }
1788 hctx->tags = NULL;
1789 continue;
1790 }
1791
1792
1793 if (!set->tags[i])
1794 set->tags[i] = blk_mq_init_rq_map(set, i);
1795 hctx->tags = set->tags[i];
1796 WARN_ON(!hctx->tags);
1797
1798
1799
1800
1801
1802
1803 sbitmap_resize(&hctx->ctx_map, hctx->nr_ctx);
1804
1805
1806
1807
1808 hctx->next_cpu = cpumask_first(hctx->cpumask);
1809 hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
1810 }
1811}
1812
1813static void queue_set_hctx_shared(struct request_queue *q, bool shared)
1814{
1815 struct blk_mq_hw_ctx *hctx;
1816 int i;
1817
1818 queue_for_each_hw_ctx(q, hctx, i) {
1819 if (shared)
1820 hctx->flags |= BLK_MQ_F_TAG_SHARED;
1821 else
1822 hctx->flags &= ~BLK_MQ_F_TAG_SHARED;
1823 }
1824}
1825
1826static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set, bool shared)
1827{
1828 struct request_queue *q;
1829
1830 list_for_each_entry(q, &set->tag_list, tag_set_list) {
1831 blk_mq_freeze_queue(q);
1832 queue_set_hctx_shared(q, shared);
1833 blk_mq_unfreeze_queue(q);
1834 }
1835}
1836
1837static void blk_mq_del_queue_tag_set(struct request_queue *q)
1838{
1839 struct blk_mq_tag_set *set = q->tag_set;
1840
1841 mutex_lock(&set->tag_list_lock);
1842 list_del_init(&q->tag_set_list);
1843 if (list_is_singular(&set->tag_list)) {
1844
1845 set->flags &= ~BLK_MQ_F_TAG_SHARED;
1846
1847 blk_mq_update_tag_set_depth(set, false);
1848 }
1849 mutex_unlock(&set->tag_list_lock);
1850}
1851
1852static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set,
1853 struct request_queue *q)
1854{
1855 q->tag_set = set;
1856
1857 mutex_lock(&set->tag_list_lock);
1858
1859
1860 if (!list_empty(&set->tag_list) && !(set->flags & BLK_MQ_F_TAG_SHARED)) {
1861 set->flags |= BLK_MQ_F_TAG_SHARED;
1862
1863 blk_mq_update_tag_set_depth(set, true);
1864 }
1865 if (set->flags & BLK_MQ_F_TAG_SHARED)
1866 queue_set_hctx_shared(q, true);
1867 list_add_tail(&q->tag_set_list, &set->tag_list);
1868
1869 mutex_unlock(&set->tag_list_lock);
1870}
1871
1872
1873
1874
1875
1876
1877
1878void blk_mq_release(struct request_queue *q)
1879{
1880 struct blk_mq_hw_ctx *hctx;
1881 unsigned int i;
1882
1883
1884 queue_for_each_hw_ctx(q, hctx, i) {
1885 if (!hctx)
1886 continue;
1887 kfree(hctx->ctxs);
1888 kfree(hctx);
1889 }
1890
1891 q->mq_map = NULL;
1892
1893 kfree(q->queue_hw_ctx);
1894
1895
1896 free_percpu(q->queue_ctx);
1897}
1898
1899struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
1900{
1901 struct request_queue *uninit_q, *q;
1902
1903 uninit_q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node);
1904 if (!uninit_q)
1905 return ERR_PTR(-ENOMEM);
1906
1907 q = blk_mq_init_allocated_queue(set, uninit_q);
1908 if (IS_ERR(q))
1909 blk_cleanup_queue(uninit_q);
1910
1911 return q;
1912}
1913EXPORT_SYMBOL(blk_mq_init_queue);
1914
1915static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set,
1916 struct request_queue *q)
1917{
1918 int i, j;
1919 struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx;
1920
1921 blk_mq_sysfs_unregister(q);
1922 for (i = 0; i < set->nr_hw_queues; i++) {
1923 int node;
1924
1925 if (hctxs[i])
1926 continue;
1927
1928 node = blk_mq_hw_queue_to_node(q->mq_map, i);
1929 hctxs[i] = kzalloc_node(sizeof(struct blk_mq_hw_ctx),
1930 GFP_KERNEL, node);
1931 if (!hctxs[i])
1932 break;
1933
1934 if (!zalloc_cpumask_var_node(&hctxs[i]->cpumask, GFP_KERNEL,
1935 node)) {
1936 kfree(hctxs[i]);
1937 hctxs[i] = NULL;
1938 break;
1939 }
1940
1941 atomic_set(&hctxs[i]->nr_active, 0);
1942 hctxs[i]->numa_node = node;
1943 hctxs[i]->queue_num = i;
1944
1945 if (blk_mq_init_hctx(q, set, hctxs[i], i)) {
1946 free_cpumask_var(hctxs[i]->cpumask);
1947 kfree(hctxs[i]);
1948 hctxs[i] = NULL;
1949 break;
1950 }
1951 blk_mq_hctx_kobj_init(hctxs[i]);
1952 }
1953 for (j = i; j < q->nr_hw_queues; j++) {
1954 struct blk_mq_hw_ctx *hctx = hctxs[j];
1955
1956 if (hctx) {
1957 if (hctx->tags) {
1958 blk_mq_free_rq_map(set, hctx->tags, j);
1959 set->tags[j] = NULL;
1960 }
1961 blk_mq_exit_hctx(q, set, hctx, j);
1962 free_cpumask_var(hctx->cpumask);
1963 kobject_put(&hctx->kobj);
1964 kfree(hctx->ctxs);
1965 kfree(hctx);
1966 hctxs[j] = NULL;
1967
1968 }
1969 }
1970 q->nr_hw_queues = i;
1971 blk_mq_sysfs_register(q);
1972}
1973
1974struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
1975 struct request_queue *q)
1976{
1977
1978 q->mq_ops = set->ops;
1979
1980 q->queue_ctx = alloc_percpu(struct blk_mq_ctx);
1981 if (!q->queue_ctx)
1982 goto err_exit;
1983
1984 q->queue_hw_ctx = kzalloc_node(nr_cpu_ids * sizeof(*(q->queue_hw_ctx)),
1985 GFP_KERNEL, set->numa_node);
1986 if (!q->queue_hw_ctx)
1987 goto err_percpu;
1988
1989 q->mq_map = set->mq_map;
1990
1991 blk_mq_realloc_hw_ctxs(set, q);
1992 if (!q->nr_hw_queues)
1993 goto err_hctxs;
1994
1995 INIT_WORK(&q->timeout_work, blk_mq_timeout_work);
1996 blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ);
1997
1998 q->nr_queues = nr_cpu_ids;
1999
2000 q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;
2001
2002 if (!(set->flags & BLK_MQ_F_SG_MERGE))
2003 q->queue_flags |= 1 << QUEUE_FLAG_NO_SG_MERGE;
2004
2005 q->sg_reserved_size = INT_MAX;
2006
2007 INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work);
2008 INIT_LIST_HEAD(&q->requeue_list);
2009 spin_lock_init(&q->requeue_lock);
2010
2011 if (q->nr_hw_queues > 1)
2012 blk_queue_make_request(q, blk_mq_make_request);
2013 else
2014 blk_queue_make_request(q, blk_sq_make_request);
2015
2016
2017
2018
2019 q->nr_requests = set->queue_depth;
2020
2021 if (set->ops->complete)
2022 blk_queue_softirq_done(q, set->ops->complete);
2023
2024 blk_mq_init_cpu_queues(q, set->nr_hw_queues);
2025
2026 get_online_cpus();
2027 mutex_lock(&all_q_mutex);
2028
2029 list_add_tail(&q->all_q_node, &all_q_list);
2030 blk_mq_add_queue_tag_set(set, q);
2031 blk_mq_map_swqueue(q, cpu_online_mask);
2032
2033 mutex_unlock(&all_q_mutex);
2034 put_online_cpus();
2035
2036 return q;
2037
2038err_hctxs:
2039 kfree(q->queue_hw_ctx);
2040err_percpu:
2041 free_percpu(q->queue_ctx);
2042err_exit:
2043 q->mq_ops = NULL;
2044 return ERR_PTR(-ENOMEM);
2045}
2046EXPORT_SYMBOL(blk_mq_init_allocated_queue);
2047
2048void blk_mq_free_queue(struct request_queue *q)
2049{
2050 struct blk_mq_tag_set *set = q->tag_set;
2051
2052 mutex_lock(&all_q_mutex);
2053 list_del_init(&q->all_q_node);
2054 mutex_unlock(&all_q_mutex);
2055
2056 blk_mq_del_queue_tag_set(q);
2057
2058 blk_mq_exit_hw_queues(q, set, set->nr_hw_queues);
2059 blk_mq_free_hw_queues(q, set);
2060}
2061
2062
2063static void blk_mq_queue_reinit(struct request_queue *q,
2064 const struct cpumask *online_mask)
2065{
2066 WARN_ON_ONCE(!atomic_read(&q->mq_freeze_depth));
2067
2068 blk_mq_sysfs_unregister(q);
2069
2070
2071
2072
2073
2074
2075
2076 blk_mq_map_swqueue(q, online_mask);
2077
2078 blk_mq_sysfs_register(q);
2079}
2080
2081
2082
2083
2084
2085
2086static struct cpumask cpuhp_online_new;
2087
2088static void blk_mq_queue_reinit_work(void)
2089{
2090 struct request_queue *q;
2091
2092 mutex_lock(&all_q_mutex);
2093
2094
2095
2096
2097
2098
2099
2100 list_for_each_entry(q, &all_q_list, all_q_node)
2101 blk_mq_freeze_queue_start(q);
2102 list_for_each_entry(q, &all_q_list, all_q_node) {
2103 blk_mq_freeze_queue_wait(q);
2104
2105
2106
2107
2108
2109 del_timer_sync(&q->timeout);
2110 }
2111
2112 list_for_each_entry(q, &all_q_list, all_q_node)
2113 blk_mq_queue_reinit(q, &cpuhp_online_new);
2114
2115 list_for_each_entry(q, &all_q_list, all_q_node)
2116 blk_mq_unfreeze_queue(q);
2117
2118 mutex_unlock(&all_q_mutex);
2119}
2120
2121static int blk_mq_queue_reinit_dead(unsigned int cpu)
2122{
2123 cpumask_copy(&cpuhp_online_new, cpu_online_mask);
2124 blk_mq_queue_reinit_work();
2125 return 0;
2126}
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144static int blk_mq_queue_reinit_prepare(unsigned int cpu)
2145{
2146 cpumask_copy(&cpuhp_online_new, cpu_online_mask);
2147 cpumask_set_cpu(cpu, &cpuhp_online_new);
2148 blk_mq_queue_reinit_work();
2149 return 0;
2150}
2151
2152static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
2153{
2154 int i;
2155
2156 for (i = 0; i < set->nr_hw_queues; i++) {
2157 set->tags[i] = blk_mq_init_rq_map(set, i);
2158 if (!set->tags[i])
2159 goto out_unwind;
2160 }
2161
2162 return 0;
2163
2164out_unwind:
2165 while (--i >= 0)
2166 blk_mq_free_rq_map(set, set->tags[i], i);
2167
2168 return -ENOMEM;
2169}
2170
2171
2172
2173
2174
2175
2176static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
2177{
2178 unsigned int depth;
2179 int err;
2180
2181 depth = set->queue_depth;
2182 do {
2183 err = __blk_mq_alloc_rq_maps(set);
2184 if (!err)
2185 break;
2186
2187 set->queue_depth >>= 1;
2188 if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) {
2189 err = -ENOMEM;
2190 break;
2191 }
2192 } while (set->queue_depth);
2193
2194 if (!set->queue_depth || err) {
2195 pr_err("blk-mq: failed to allocate request map\n");
2196 return -ENOMEM;
2197 }
2198
2199 if (depth != set->queue_depth)
2200 pr_info("blk-mq: reduced tag depth (%u -> %u)\n",
2201 depth, set->queue_depth);
2202
2203 return 0;
2204}
2205
2206
2207
2208
2209
2210
2211
2212int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
2213{
2214 int ret;
2215
2216 BUILD_BUG_ON(BLK_MQ_MAX_DEPTH > 1 << BLK_MQ_UNIQUE_TAG_BITS);
2217
2218 if (!set->nr_hw_queues)
2219 return -EINVAL;
2220 if (!set->queue_depth)
2221 return -EINVAL;
2222 if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN)
2223 return -EINVAL;
2224
2225 if (!set->ops->queue_rq)
2226 return -EINVAL;
2227
2228 if (set->queue_depth > BLK_MQ_MAX_DEPTH) {
2229 pr_info("blk-mq: reduced tag depth to %u\n",
2230 BLK_MQ_MAX_DEPTH);
2231 set->queue_depth = BLK_MQ_MAX_DEPTH;
2232 }
2233
2234
2235
2236
2237
2238
2239 if (is_kdump_kernel()) {
2240 set->nr_hw_queues = 1;
2241 set->queue_depth = min(64U, set->queue_depth);
2242 }
2243
2244
2245
2246 if (set->nr_hw_queues > nr_cpu_ids)
2247 set->nr_hw_queues = nr_cpu_ids;
2248
2249 set->tags = kzalloc_node(nr_cpu_ids * sizeof(struct blk_mq_tags *),
2250 GFP_KERNEL, set->numa_node);
2251 if (!set->tags)
2252 return -ENOMEM;
2253
2254 ret = -ENOMEM;
2255 set->mq_map = kzalloc_node(sizeof(*set->mq_map) * nr_cpu_ids,
2256 GFP_KERNEL, set->numa_node);
2257 if (!set->mq_map)
2258 goto out_free_tags;
2259
2260 if (set->ops->map_queues)
2261 ret = set->ops->map_queues(set);
2262 else
2263 ret = blk_mq_map_queues(set);
2264 if (ret)
2265 goto out_free_mq_map;
2266
2267 ret = blk_mq_alloc_rq_maps(set);
2268 if (ret)
2269 goto out_free_mq_map;
2270
2271 mutex_init(&set->tag_list_lock);
2272 INIT_LIST_HEAD(&set->tag_list);
2273
2274 return 0;
2275
2276out_free_mq_map:
2277 kfree(set->mq_map);
2278 set->mq_map = NULL;
2279out_free_tags:
2280 kfree(set->tags);
2281 set->tags = NULL;
2282 return ret;
2283}
2284EXPORT_SYMBOL(blk_mq_alloc_tag_set);
2285
2286void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
2287{
2288 int i;
2289
2290 for (i = 0; i < nr_cpu_ids; i++) {
2291 if (set->tags[i])
2292 blk_mq_free_rq_map(set, set->tags[i], i);
2293 }
2294
2295 kfree(set->mq_map);
2296 set->mq_map = NULL;
2297
2298 kfree(set->tags);
2299 set->tags = NULL;
2300}
2301EXPORT_SYMBOL(blk_mq_free_tag_set);
2302
2303int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
2304{
2305 struct blk_mq_tag_set *set = q->tag_set;
2306 struct blk_mq_hw_ctx *hctx;
2307 int i, ret;
2308
2309 if (!set || nr > set->queue_depth)
2310 return -EINVAL;
2311
2312 ret = 0;
2313 queue_for_each_hw_ctx(q, hctx, i) {
2314 if (!hctx->tags)
2315 continue;
2316 ret = blk_mq_tag_update_depth(hctx->tags, nr);
2317 if (ret)
2318 break;
2319 }
2320
2321 if (!ret)
2322 q->nr_requests = nr;
2323
2324 return ret;
2325}
2326
2327void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues)
2328{
2329 struct request_queue *q;
2330
2331 if (nr_hw_queues > nr_cpu_ids)
2332 nr_hw_queues = nr_cpu_ids;
2333 if (nr_hw_queues < 1 || nr_hw_queues == set->nr_hw_queues)
2334 return;
2335
2336 list_for_each_entry(q, &set->tag_list, tag_set_list)
2337 blk_mq_freeze_queue(q);
2338
2339 set->nr_hw_queues = nr_hw_queues;
2340 list_for_each_entry(q, &set->tag_list, tag_set_list) {
2341 blk_mq_realloc_hw_ctxs(set, q);
2342
2343 if (q->nr_hw_queues > 1)
2344 blk_queue_make_request(q, blk_mq_make_request);
2345 else
2346 blk_queue_make_request(q, blk_sq_make_request);
2347
2348 blk_mq_queue_reinit(q, cpu_online_mask);
2349 }
2350
2351 list_for_each_entry(q, &set->tag_list, tag_set_list)
2352 blk_mq_unfreeze_queue(q);
2353}
2354EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues);
2355
2356void blk_mq_disable_hotplug(void)
2357{
2358 mutex_lock(&all_q_mutex);
2359}
2360
2361void blk_mq_enable_hotplug(void)
2362{
2363 mutex_unlock(&all_q_mutex);
2364}
2365
2366static int __init blk_mq_init(void)
2367{
2368 cpuhp_setup_state_multi(CPUHP_BLK_MQ_DEAD, "block/mq:dead", NULL,
2369 blk_mq_hctx_notify_dead);
2370
2371 cpuhp_setup_state_nocalls(CPUHP_BLK_MQ_PREPARE, "block/mq:prepare",
2372 blk_mq_queue_reinit_prepare,
2373 blk_mq_queue_reinit_dead);
2374 return 0;
2375}
2376subsys_initcall(blk_mq_init);
2377