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7
8#include <linux/kernel.h>
9#include <linux/module.h>
10#include <linux/backing-dev.h>
11#include <linux/bio.h>
12#include <linux/blkdev.h>
13#include <linux/kmemleak.h>
14#include <linux/mm.h>
15#include <linux/init.h>
16#include <linux/slab.h>
17#include <linux/workqueue.h>
18#include <linux/smp.h>
19#include <linux/llist.h>
20#include <linux/list_sort.h>
21#include <linux/cpu.h>
22#include <linux/cache.h>
23#include <linux/sched/sysctl.h>
24#include <linux/sched/topology.h>
25#include <linux/sched/signal.h>
26#include <linux/delay.h>
27#include <linux/crash_dump.h>
28#include <linux/prefetch.h>
29#include <linux/blk-crypto.h>
30
31#include <trace/events/block.h>
32
33#include <linux/blk-mq.h>
34#include <linux/t10-pi.h>
35#include "blk.h"
36#include "blk-mq.h"
37#include "blk-mq-debugfs.h"
38#include "blk-mq-tag.h"
39#include "blk-pm.h"
40#include "blk-stat.h"
41#include "blk-mq-sched.h"
42#include "blk-rq-qos.h"
43
44static DEFINE_PER_CPU(struct llist_head, blk_cpu_done);
45
46static void blk_mq_poll_stats_start(struct request_queue *q);
47static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb);
48
49static int blk_mq_poll_stats_bkt(const struct request *rq)
50{
51 int ddir, sectors, bucket;
52
53 ddir = rq_data_dir(rq);
54 sectors = blk_rq_stats_sectors(rq);
55
56 bucket = ddir + 2 * ilog2(sectors);
57
58 if (bucket < 0)
59 return -1;
60 else if (bucket >= BLK_MQ_POLL_STATS_BKTS)
61 return ddir + BLK_MQ_POLL_STATS_BKTS - 2;
62
63 return bucket;
64}
65
66
67
68
69
70static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx)
71{
72 return !list_empty_careful(&hctx->dispatch) ||
73 sbitmap_any_bit_set(&hctx->ctx_map) ||
74 blk_mq_sched_has_work(hctx);
75}
76
77
78
79
80static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx,
81 struct blk_mq_ctx *ctx)
82{
83 const int bit = ctx->index_hw[hctx->type];
84
85 if (!sbitmap_test_bit(&hctx->ctx_map, bit))
86 sbitmap_set_bit(&hctx->ctx_map, bit);
87}
88
89static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx,
90 struct blk_mq_ctx *ctx)
91{
92 const int bit = ctx->index_hw[hctx->type];
93
94 sbitmap_clear_bit(&hctx->ctx_map, bit);
95}
96
97struct mq_inflight {
98 struct block_device *part;
99 unsigned int inflight[2];
100};
101
102static bool blk_mq_check_inflight(struct blk_mq_hw_ctx *hctx,
103 struct request *rq, void *priv,
104 bool reserved)
105{
106 struct mq_inflight *mi = priv;
107
108 if ((!mi->part->bd_partno || rq->part == mi->part) &&
109 blk_mq_rq_state(rq) == MQ_RQ_IN_FLIGHT)
110 mi->inflight[rq_data_dir(rq)]++;
111
112 return true;
113}
114
115unsigned int blk_mq_in_flight(struct request_queue *q,
116 struct block_device *part)
117{
118 struct mq_inflight mi = { .part = part };
119
120 blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi);
121
122 return mi.inflight[0] + mi.inflight[1];
123}
124
125void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part,
126 unsigned int inflight[2])
127{
128 struct mq_inflight mi = { .part = part };
129
130 blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi);
131 inflight[0] = mi.inflight[0];
132 inflight[1] = mi.inflight[1];
133}
134
135void blk_freeze_queue_start(struct request_queue *q)
136{
137 mutex_lock(&q->mq_freeze_lock);
138 if (++q->mq_freeze_depth == 1) {
139 percpu_ref_kill(&q->q_usage_counter);
140 mutex_unlock(&q->mq_freeze_lock);
141 if (queue_is_mq(q))
142 blk_mq_run_hw_queues(q, false);
143 } else {
144 mutex_unlock(&q->mq_freeze_lock);
145 }
146}
147EXPORT_SYMBOL_GPL(blk_freeze_queue_start);
148
149void blk_mq_freeze_queue_wait(struct request_queue *q)
150{
151 wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter));
152}
153EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait);
154
155int blk_mq_freeze_queue_wait_timeout(struct request_queue *q,
156 unsigned long timeout)
157{
158 return wait_event_timeout(q->mq_freeze_wq,
159 percpu_ref_is_zero(&q->q_usage_counter),
160 timeout);
161}
162EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait_timeout);
163
164
165
166
167
168void blk_freeze_queue(struct request_queue *q)
169{
170
171
172
173
174
175
176
177 blk_freeze_queue_start(q);
178 blk_mq_freeze_queue_wait(q);
179}
180
181void blk_mq_freeze_queue(struct request_queue *q)
182{
183
184
185
186
187 blk_freeze_queue(q);
188}
189EXPORT_SYMBOL_GPL(blk_mq_freeze_queue);
190
191void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic)
192{
193 mutex_lock(&q->mq_freeze_lock);
194 if (force_atomic)
195 q->q_usage_counter.data->force_atomic = true;
196 q->mq_freeze_depth--;
197 WARN_ON_ONCE(q->mq_freeze_depth < 0);
198 if (!q->mq_freeze_depth) {
199 percpu_ref_resurrect(&q->q_usage_counter);
200 wake_up_all(&q->mq_freeze_wq);
201 }
202 mutex_unlock(&q->mq_freeze_lock);
203}
204
205void blk_mq_unfreeze_queue(struct request_queue *q)
206{
207 __blk_mq_unfreeze_queue(q, false);
208}
209EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);
210
211
212
213
214
215void blk_mq_quiesce_queue_nowait(struct request_queue *q)
216{
217 blk_queue_flag_set(QUEUE_FLAG_QUIESCED, q);
218}
219EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue_nowait);
220
221
222
223
224
225
226
227
228
229
230void blk_mq_quiesce_queue(struct request_queue *q)
231{
232 struct blk_mq_hw_ctx *hctx;
233 unsigned int i;
234 bool rcu = false;
235
236 blk_mq_quiesce_queue_nowait(q);
237
238 queue_for_each_hw_ctx(q, hctx, i) {
239 if (hctx->flags & BLK_MQ_F_BLOCKING)
240 synchronize_srcu(hctx->srcu);
241 else
242 rcu = true;
243 }
244 if (rcu)
245 synchronize_rcu();
246}
247EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue);
248
249
250
251
252
253
254
255
256void blk_mq_unquiesce_queue(struct request_queue *q)
257{
258 blk_queue_flag_clear(QUEUE_FLAG_QUIESCED, q);
259
260
261 blk_mq_run_hw_queues(q, true);
262}
263EXPORT_SYMBOL_GPL(blk_mq_unquiesce_queue);
264
265void blk_mq_wake_waiters(struct request_queue *q)
266{
267 struct blk_mq_hw_ctx *hctx;
268 unsigned int i;
269
270 queue_for_each_hw_ctx(q, hctx, i)
271 if (blk_mq_hw_queue_mapped(hctx))
272 blk_mq_tag_wakeup_all(hctx->tags, true);
273}
274
275
276
277
278
279static inline bool blk_mq_need_time_stamp(struct request *rq)
280{
281 return (rq->rq_flags & (RQF_IO_STAT | RQF_STATS)) || rq->q->elevator;
282}
283
284static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
285 unsigned int tag, u64 alloc_time_ns)
286{
287 struct blk_mq_tags *tags = blk_mq_tags_from_data(data);
288 struct request *rq = tags->static_rqs[tag];
289
290 if (data->q->elevator) {
291 rq->tag = BLK_MQ_NO_TAG;
292 rq->internal_tag = tag;
293 } else {
294 rq->tag = tag;
295 rq->internal_tag = BLK_MQ_NO_TAG;
296 }
297
298
299 rq->q = data->q;
300 rq->mq_ctx = data->ctx;
301 rq->mq_hctx = data->hctx;
302 rq->rq_flags = 0;
303 rq->cmd_flags = data->cmd_flags;
304 if (data->flags & BLK_MQ_REQ_PM)
305 rq->rq_flags |= RQF_PM;
306 if (blk_queue_io_stat(data->q))
307 rq->rq_flags |= RQF_IO_STAT;
308 INIT_LIST_HEAD(&rq->queuelist);
309 INIT_HLIST_NODE(&rq->hash);
310 RB_CLEAR_NODE(&rq->rb_node);
311 rq->rq_disk = NULL;
312 rq->part = NULL;
313#ifdef CONFIG_BLK_RQ_ALLOC_TIME
314 rq->alloc_time_ns = alloc_time_ns;
315#endif
316 if (blk_mq_need_time_stamp(rq))
317 rq->start_time_ns = ktime_get_ns();
318 else
319 rq->start_time_ns = 0;
320 rq->io_start_time_ns = 0;
321 rq->stats_sectors = 0;
322 rq->nr_phys_segments = 0;
323#if defined(CONFIG_BLK_DEV_INTEGRITY)
324 rq->nr_integrity_segments = 0;
325#endif
326 blk_crypto_rq_set_defaults(rq);
327
328 WRITE_ONCE(rq->deadline, 0);
329
330 rq->timeout = 0;
331
332 rq->end_io = NULL;
333 rq->end_io_data = NULL;
334
335 data->ctx->rq_dispatched[op_is_sync(data->cmd_flags)]++;
336 refcount_set(&rq->ref, 1);
337
338 if (!op_is_flush(data->cmd_flags)) {
339 struct elevator_queue *e = data->q->elevator;
340
341 rq->elv.icq = NULL;
342 if (e && e->type->ops.prepare_request) {
343 if (e->type->icq_cache)
344 blk_mq_sched_assign_ioc(rq);
345
346 e->type->ops.prepare_request(rq);
347 rq->rq_flags |= RQF_ELVPRIV;
348 }
349 }
350
351 data->hctx->queued++;
352 return rq;
353}
354
355static struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data)
356{
357 struct request_queue *q = data->q;
358 struct elevator_queue *e = q->elevator;
359 u64 alloc_time_ns = 0;
360 unsigned int tag;
361
362
363 if (blk_queue_rq_alloc_time(q))
364 alloc_time_ns = ktime_get_ns();
365
366 if (data->cmd_flags & REQ_NOWAIT)
367 data->flags |= BLK_MQ_REQ_NOWAIT;
368
369 if (e) {
370
371
372
373
374
375 if (!op_is_flush(data->cmd_flags) &&
376 !blk_op_is_passthrough(data->cmd_flags) &&
377 e->type->ops.limit_depth &&
378 !(data->flags & BLK_MQ_REQ_RESERVED))
379 e->type->ops.limit_depth(data->cmd_flags, data);
380 }
381
382retry:
383 data->ctx = blk_mq_get_ctx(q);
384 data->hctx = blk_mq_map_queue(q, data->cmd_flags, data->ctx);
385 if (!e)
386 blk_mq_tag_busy(data->hctx);
387
388
389
390
391
392
393 tag = blk_mq_get_tag(data);
394 if (tag == BLK_MQ_NO_TAG) {
395 if (data->flags & BLK_MQ_REQ_NOWAIT)
396 return NULL;
397
398
399
400
401
402
403 msleep(3);
404 goto retry;
405 }
406 return blk_mq_rq_ctx_init(data, tag, alloc_time_ns);
407}
408
409struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
410 blk_mq_req_flags_t flags)
411{
412 struct blk_mq_alloc_data data = {
413 .q = q,
414 .flags = flags,
415 .cmd_flags = op,
416 };
417 struct request *rq;
418 int ret;
419
420 ret = blk_queue_enter(q, flags);
421 if (ret)
422 return ERR_PTR(ret);
423
424 rq = __blk_mq_alloc_request(&data);
425 if (!rq)
426 goto out_queue_exit;
427 rq->__data_len = 0;
428 rq->__sector = (sector_t) -1;
429 rq->bio = rq->biotail = NULL;
430 return rq;
431out_queue_exit:
432 blk_queue_exit(q);
433 return ERR_PTR(-EWOULDBLOCK);
434}
435EXPORT_SYMBOL(blk_mq_alloc_request);
436
437struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
438 unsigned int op, blk_mq_req_flags_t flags, unsigned int hctx_idx)
439{
440 struct blk_mq_alloc_data data = {
441 .q = q,
442 .flags = flags,
443 .cmd_flags = op,
444 };
445 u64 alloc_time_ns = 0;
446 unsigned int cpu;
447 unsigned int tag;
448 int ret;
449
450
451 if (blk_queue_rq_alloc_time(q))
452 alloc_time_ns = ktime_get_ns();
453
454
455
456
457
458
459
460 if (WARN_ON_ONCE(!(flags & (BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED))))
461 return ERR_PTR(-EINVAL);
462
463 if (hctx_idx >= q->nr_hw_queues)
464 return ERR_PTR(-EIO);
465
466 ret = blk_queue_enter(q, flags);
467 if (ret)
468 return ERR_PTR(ret);
469
470
471
472
473
474 ret = -EXDEV;
475 data.hctx = q->queue_hw_ctx[hctx_idx];
476 if (!blk_mq_hw_queue_mapped(data.hctx))
477 goto out_queue_exit;
478 cpu = cpumask_first_and(data.hctx->cpumask, cpu_online_mask);
479 data.ctx = __blk_mq_get_ctx(q, cpu);
480
481 if (!q->elevator)
482 blk_mq_tag_busy(data.hctx);
483
484 ret = -EWOULDBLOCK;
485 tag = blk_mq_get_tag(&data);
486 if (tag == BLK_MQ_NO_TAG)
487 goto out_queue_exit;
488 return blk_mq_rq_ctx_init(&data, tag, alloc_time_ns);
489
490out_queue_exit:
491 blk_queue_exit(q);
492 return ERR_PTR(ret);
493}
494EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx);
495
496static void __blk_mq_free_request(struct request *rq)
497{
498 struct request_queue *q = rq->q;
499 struct blk_mq_ctx *ctx = rq->mq_ctx;
500 struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
501 const int sched_tag = rq->internal_tag;
502
503 blk_crypto_free_request(rq);
504 blk_pm_mark_last_busy(rq);
505 rq->mq_hctx = NULL;
506 if (rq->tag != BLK_MQ_NO_TAG)
507 blk_mq_put_tag(hctx->tags, ctx, rq->tag);
508 if (sched_tag != BLK_MQ_NO_TAG)
509 blk_mq_put_tag(hctx->sched_tags, ctx, sched_tag);
510 blk_mq_sched_restart(hctx);
511 blk_queue_exit(q);
512}
513
514void blk_mq_free_request(struct request *rq)
515{
516 struct request_queue *q = rq->q;
517 struct elevator_queue *e = q->elevator;
518 struct blk_mq_ctx *ctx = rq->mq_ctx;
519 struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
520
521 if (rq->rq_flags & RQF_ELVPRIV) {
522 if (e && e->type->ops.finish_request)
523 e->type->ops.finish_request(rq);
524 if (rq->elv.icq) {
525 put_io_context(rq->elv.icq->ioc);
526 rq->elv.icq = NULL;
527 }
528 }
529
530 ctx->rq_completed[rq_is_sync(rq)]++;
531 if (rq->rq_flags & RQF_MQ_INFLIGHT)
532 __blk_mq_dec_active_requests(hctx);
533
534 if (unlikely(laptop_mode && !blk_rq_is_passthrough(rq)))
535 laptop_io_completion(q->disk->bdi);
536
537 rq_qos_done(q, rq);
538
539 WRITE_ONCE(rq->state, MQ_RQ_IDLE);
540 if (refcount_dec_and_test(&rq->ref))
541 __blk_mq_free_request(rq);
542}
543EXPORT_SYMBOL_GPL(blk_mq_free_request);
544
545inline void __blk_mq_end_request(struct request *rq, blk_status_t error)
546{
547 u64 now = 0;
548
549 if (blk_mq_need_time_stamp(rq))
550 now = ktime_get_ns();
551
552 if (rq->rq_flags & RQF_STATS) {
553 blk_mq_poll_stats_start(rq->q);
554 blk_stat_add(rq, now);
555 }
556
557 blk_mq_sched_completed_request(rq, now);
558
559 blk_account_io_done(rq, now);
560
561 if (rq->end_io) {
562 rq_qos_done(rq->q, rq);
563 rq->end_io(rq, error);
564 } else {
565 blk_mq_free_request(rq);
566 }
567}
568EXPORT_SYMBOL(__blk_mq_end_request);
569
570void blk_mq_end_request(struct request *rq, blk_status_t error)
571{
572 if (blk_update_request(rq, error, blk_rq_bytes(rq)))
573 BUG();
574 __blk_mq_end_request(rq, error);
575}
576EXPORT_SYMBOL(blk_mq_end_request);
577
578static void blk_complete_reqs(struct llist_head *list)
579{
580 struct llist_node *entry = llist_reverse_order(llist_del_all(list));
581 struct request *rq, *next;
582
583 llist_for_each_entry_safe(rq, next, entry, ipi_list)
584 rq->q->mq_ops->complete(rq);
585}
586
587static __latent_entropy void blk_done_softirq(struct softirq_action *h)
588{
589 blk_complete_reqs(this_cpu_ptr(&blk_cpu_done));
590}
591
592static int blk_softirq_cpu_dead(unsigned int cpu)
593{
594 blk_complete_reqs(&per_cpu(blk_cpu_done, cpu));
595 return 0;
596}
597
598static void __blk_mq_complete_request_remote(void *data)
599{
600 __raise_softirq_irqoff(BLOCK_SOFTIRQ);
601}
602
603static inline bool blk_mq_complete_need_ipi(struct request *rq)
604{
605 int cpu = raw_smp_processor_id();
606
607 if (!IS_ENABLED(CONFIG_SMP) ||
608 !test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags))
609 return false;
610
611
612
613
614
615
616 if (force_irqthreads())
617 return false;
618
619
620 if (cpu == rq->mq_ctx->cpu ||
621 (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags) &&
622 cpus_share_cache(cpu, rq->mq_ctx->cpu)))
623 return false;
624
625
626 return cpu_online(rq->mq_ctx->cpu);
627}
628
629static void blk_mq_complete_send_ipi(struct request *rq)
630{
631 struct llist_head *list;
632 unsigned int cpu;
633
634 cpu = rq->mq_ctx->cpu;
635 list = &per_cpu(blk_cpu_done, cpu);
636 if (llist_add(&rq->ipi_list, list)) {
637 INIT_CSD(&rq->csd, __blk_mq_complete_request_remote, rq);
638 smp_call_function_single_async(cpu, &rq->csd);
639 }
640}
641
642static void blk_mq_raise_softirq(struct request *rq)
643{
644 struct llist_head *list;
645
646 preempt_disable();
647 list = this_cpu_ptr(&blk_cpu_done);
648 if (llist_add(&rq->ipi_list, list))
649 raise_softirq(BLOCK_SOFTIRQ);
650 preempt_enable();
651}
652
653bool blk_mq_complete_request_remote(struct request *rq)
654{
655 WRITE_ONCE(rq->state, MQ_RQ_COMPLETE);
656
657
658
659
660
661 if (rq->cmd_flags & REQ_HIPRI)
662 return false;
663
664 if (blk_mq_complete_need_ipi(rq)) {
665 blk_mq_complete_send_ipi(rq);
666 return true;
667 }
668
669 if (rq->q->nr_hw_queues == 1) {
670 blk_mq_raise_softirq(rq);
671 return true;
672 }
673 return false;
674}
675EXPORT_SYMBOL_GPL(blk_mq_complete_request_remote);
676
677
678
679
680
681
682
683
684void blk_mq_complete_request(struct request *rq)
685{
686 if (!blk_mq_complete_request_remote(rq))
687 rq->q->mq_ops->complete(rq);
688}
689EXPORT_SYMBOL(blk_mq_complete_request);
690
691static void hctx_unlock(struct blk_mq_hw_ctx *hctx, int srcu_idx)
692 __releases(hctx->srcu)
693{
694 if (!(hctx->flags & BLK_MQ_F_BLOCKING))
695 rcu_read_unlock();
696 else
697 srcu_read_unlock(hctx->srcu, srcu_idx);
698}
699
700static void hctx_lock(struct blk_mq_hw_ctx *hctx, int *srcu_idx)
701 __acquires(hctx->srcu)
702{
703 if (!(hctx->flags & BLK_MQ_F_BLOCKING)) {
704
705 *srcu_idx = 0;
706 rcu_read_lock();
707 } else
708 *srcu_idx = srcu_read_lock(hctx->srcu);
709}
710
711
712
713
714
715
716
717
718
719void blk_mq_start_request(struct request *rq)
720{
721 struct request_queue *q = rq->q;
722
723 trace_block_rq_issue(rq);
724
725 if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags)) {
726 rq->io_start_time_ns = ktime_get_ns();
727 rq->stats_sectors = blk_rq_sectors(rq);
728 rq->rq_flags |= RQF_STATS;
729 rq_qos_issue(q, rq);
730 }
731
732 WARN_ON_ONCE(blk_mq_rq_state(rq) != MQ_RQ_IDLE);
733
734 blk_add_timer(rq);
735 WRITE_ONCE(rq->state, MQ_RQ_IN_FLIGHT);
736
737#ifdef CONFIG_BLK_DEV_INTEGRITY
738 if (blk_integrity_rq(rq) && req_op(rq) == REQ_OP_WRITE)
739 q->integrity.profile->prepare_fn(rq);
740#endif
741}
742EXPORT_SYMBOL(blk_mq_start_request);
743
744static void __blk_mq_requeue_request(struct request *rq)
745{
746 struct request_queue *q = rq->q;
747
748 blk_mq_put_driver_tag(rq);
749
750 trace_block_rq_requeue(rq);
751 rq_qos_requeue(q, rq);
752
753 if (blk_mq_request_started(rq)) {
754 WRITE_ONCE(rq->state, MQ_RQ_IDLE);
755 rq->rq_flags &= ~RQF_TIMED_OUT;
756 }
757}
758
759void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list)
760{
761 __blk_mq_requeue_request(rq);
762
763
764 blk_mq_sched_requeue_request(rq);
765
766 BUG_ON(!list_empty(&rq->queuelist));
767 blk_mq_add_to_requeue_list(rq, true, kick_requeue_list);
768}
769EXPORT_SYMBOL(blk_mq_requeue_request);
770
771static void blk_mq_requeue_work(struct work_struct *work)
772{
773 struct request_queue *q =
774 container_of(work, struct request_queue, requeue_work.work);
775 LIST_HEAD(rq_list);
776 struct request *rq, *next;
777
778 spin_lock_irq(&q->requeue_lock);
779 list_splice_init(&q->requeue_list, &rq_list);
780 spin_unlock_irq(&q->requeue_lock);
781
782 list_for_each_entry_safe(rq, next, &rq_list, queuelist) {
783 if (!(rq->rq_flags & (RQF_SOFTBARRIER | RQF_DONTPREP)))
784 continue;
785
786 rq->rq_flags &= ~RQF_SOFTBARRIER;
787 list_del_init(&rq->queuelist);
788
789
790
791
792
793 if (rq->rq_flags & RQF_DONTPREP)
794 blk_mq_request_bypass_insert(rq, false, false);
795 else
796 blk_mq_sched_insert_request(rq, true, false, false);
797 }
798
799 while (!list_empty(&rq_list)) {
800 rq = list_entry(rq_list.next, struct request, queuelist);
801 list_del_init(&rq->queuelist);
802 blk_mq_sched_insert_request(rq, false, false, false);
803 }
804
805 blk_mq_run_hw_queues(q, false);
806}
807
808void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
809 bool kick_requeue_list)
810{
811 struct request_queue *q = rq->q;
812 unsigned long flags;
813
814
815
816
817
818 BUG_ON(rq->rq_flags & RQF_SOFTBARRIER);
819
820 spin_lock_irqsave(&q->requeue_lock, flags);
821 if (at_head) {
822 rq->rq_flags |= RQF_SOFTBARRIER;
823 list_add(&rq->queuelist, &q->requeue_list);
824 } else {
825 list_add_tail(&rq->queuelist, &q->requeue_list);
826 }
827 spin_unlock_irqrestore(&q->requeue_lock, flags);
828
829 if (kick_requeue_list)
830 blk_mq_kick_requeue_list(q);
831}
832
833void blk_mq_kick_requeue_list(struct request_queue *q)
834{
835 kblockd_mod_delayed_work_on(WORK_CPU_UNBOUND, &q->requeue_work, 0);
836}
837EXPORT_SYMBOL(blk_mq_kick_requeue_list);
838
839void blk_mq_delay_kick_requeue_list(struct request_queue *q,
840 unsigned long msecs)
841{
842 kblockd_mod_delayed_work_on(WORK_CPU_UNBOUND, &q->requeue_work,
843 msecs_to_jiffies(msecs));
844}
845EXPORT_SYMBOL(blk_mq_delay_kick_requeue_list);
846
847struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag)
848{
849 if (tag < tags->nr_tags) {
850 prefetch(tags->rqs[tag]);
851 return tags->rqs[tag];
852 }
853
854 return NULL;
855}
856EXPORT_SYMBOL(blk_mq_tag_to_rq);
857
858static bool blk_mq_rq_inflight(struct blk_mq_hw_ctx *hctx, struct request *rq,
859 void *priv, bool reserved)
860{
861
862
863
864
865 if (blk_mq_request_started(rq) && rq->q == hctx->queue) {
866 bool *busy = priv;
867
868 *busy = true;
869 return false;
870 }
871
872 return true;
873}
874
875bool blk_mq_queue_inflight(struct request_queue *q)
876{
877 bool busy = false;
878
879 blk_mq_queue_tag_busy_iter(q, blk_mq_rq_inflight, &busy);
880 return busy;
881}
882EXPORT_SYMBOL_GPL(blk_mq_queue_inflight);
883
884static void blk_mq_rq_timed_out(struct request *req, bool reserved)
885{
886 req->rq_flags |= RQF_TIMED_OUT;
887 if (req->q->mq_ops->timeout) {
888 enum blk_eh_timer_return ret;
889
890 ret = req->q->mq_ops->timeout(req, reserved);
891 if (ret == BLK_EH_DONE)
892 return;
893 WARN_ON_ONCE(ret != BLK_EH_RESET_TIMER);
894 }
895
896 blk_add_timer(req);
897}
898
899static bool blk_mq_req_expired(struct request *rq, unsigned long *next)
900{
901 unsigned long deadline;
902
903 if (blk_mq_rq_state(rq) != MQ_RQ_IN_FLIGHT)
904 return false;
905 if (rq->rq_flags & RQF_TIMED_OUT)
906 return false;
907
908 deadline = READ_ONCE(rq->deadline);
909 if (time_after_eq(jiffies, deadline))
910 return true;
911
912 if (*next == 0)
913 *next = deadline;
914 else if (time_after(*next, deadline))
915 *next = deadline;
916 return false;
917}
918
919void blk_mq_put_rq_ref(struct request *rq)
920{
921 if (is_flush_rq(rq))
922 rq->end_io(rq, 0);
923 else if (refcount_dec_and_test(&rq->ref))
924 __blk_mq_free_request(rq);
925}
926
927static bool blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
928 struct request *rq, void *priv, bool reserved)
929{
930 unsigned long *next = priv;
931
932
933
934
935
936
937
938
939 if (blk_mq_req_expired(rq, next))
940 blk_mq_rq_timed_out(rq, reserved);
941 return true;
942}
943
944static void blk_mq_timeout_work(struct work_struct *work)
945{
946 struct request_queue *q =
947 container_of(work, struct request_queue, timeout_work);
948 unsigned long next = 0;
949 struct blk_mq_hw_ctx *hctx;
950 int i;
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965 if (!percpu_ref_tryget(&q->q_usage_counter))
966 return;
967
968 blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &next);
969
970 if (next != 0) {
971 mod_timer(&q->timeout, next);
972 } else {
973
974
975
976
977
978
979 queue_for_each_hw_ctx(q, hctx, i) {
980
981 if (blk_mq_hw_queue_mapped(hctx))
982 blk_mq_tag_idle(hctx);
983 }
984 }
985 blk_queue_exit(q);
986}
987
988struct flush_busy_ctx_data {
989 struct blk_mq_hw_ctx *hctx;
990 struct list_head *list;
991};
992
993static bool flush_busy_ctx(struct sbitmap *sb, unsigned int bitnr, void *data)
994{
995 struct flush_busy_ctx_data *flush_data = data;
996 struct blk_mq_hw_ctx *hctx = flush_data->hctx;
997 struct blk_mq_ctx *ctx = hctx->ctxs[bitnr];
998 enum hctx_type type = hctx->type;
999
1000 spin_lock(&ctx->lock);
1001 list_splice_tail_init(&ctx->rq_lists[type], flush_data->list);
1002 sbitmap_clear_bit(sb, bitnr);
1003 spin_unlock(&ctx->lock);
1004 return true;
1005}
1006
1007
1008
1009
1010
1011void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list)
1012{
1013 struct flush_busy_ctx_data data = {
1014 .hctx = hctx,
1015 .list = list,
1016 };
1017
1018 sbitmap_for_each_set(&hctx->ctx_map, flush_busy_ctx, &data);
1019}
1020EXPORT_SYMBOL_GPL(blk_mq_flush_busy_ctxs);
1021
1022struct dispatch_rq_data {
1023 struct blk_mq_hw_ctx *hctx;
1024 struct request *rq;
1025};
1026
1027static bool dispatch_rq_from_ctx(struct sbitmap *sb, unsigned int bitnr,
1028 void *data)
1029{
1030 struct dispatch_rq_data *dispatch_data = data;
1031 struct blk_mq_hw_ctx *hctx = dispatch_data->hctx;
1032 struct blk_mq_ctx *ctx = hctx->ctxs[bitnr];
1033 enum hctx_type type = hctx->type;
1034
1035 spin_lock(&ctx->lock);
1036 if (!list_empty(&ctx->rq_lists[type])) {
1037 dispatch_data->rq = list_entry_rq(ctx->rq_lists[type].next);
1038 list_del_init(&dispatch_data->rq->queuelist);
1039 if (list_empty(&ctx->rq_lists[type]))
1040 sbitmap_clear_bit(sb, bitnr);
1041 }
1042 spin_unlock(&ctx->lock);
1043
1044 return !dispatch_data->rq;
1045}
1046
1047struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
1048 struct blk_mq_ctx *start)
1049{
1050 unsigned off = start ? start->index_hw[hctx->type] : 0;
1051 struct dispatch_rq_data data = {
1052 .hctx = hctx,
1053 .rq = NULL,
1054 };
1055
1056 __sbitmap_for_each_set(&hctx->ctx_map, off,
1057 dispatch_rq_from_ctx, &data);
1058
1059 return data.rq;
1060}
1061
1062static inline unsigned int queued_to_index(unsigned int queued)
1063{
1064 if (!queued)
1065 return 0;
1066
1067 return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1);
1068}
1069
1070static bool __blk_mq_get_driver_tag(struct request *rq)
1071{
1072 struct sbitmap_queue *bt = rq->mq_hctx->tags->bitmap_tags;
1073 unsigned int tag_offset = rq->mq_hctx->tags->nr_reserved_tags;
1074 int tag;
1075
1076 blk_mq_tag_busy(rq->mq_hctx);
1077
1078 if (blk_mq_tag_is_reserved(rq->mq_hctx->sched_tags, rq->internal_tag)) {
1079 bt = rq->mq_hctx->tags->breserved_tags;
1080 tag_offset = 0;
1081 } else {
1082 if (!hctx_may_queue(rq->mq_hctx, bt))
1083 return false;
1084 }
1085
1086 tag = __sbitmap_queue_get(bt);
1087 if (tag == BLK_MQ_NO_TAG)
1088 return false;
1089
1090 rq->tag = tag + tag_offset;
1091 return true;
1092}
1093
1094bool blk_mq_get_driver_tag(struct request *rq)
1095{
1096 struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
1097
1098 if (rq->tag == BLK_MQ_NO_TAG && !__blk_mq_get_driver_tag(rq))
1099 return false;
1100
1101 if ((hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) &&
1102 !(rq->rq_flags & RQF_MQ_INFLIGHT)) {
1103 rq->rq_flags |= RQF_MQ_INFLIGHT;
1104 __blk_mq_inc_active_requests(hctx);
1105 }
1106 hctx->tags->rqs[rq->tag] = rq;
1107 return true;
1108}
1109
1110static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode,
1111 int flags, void *key)
1112{
1113 struct blk_mq_hw_ctx *hctx;
1114
1115 hctx = container_of(wait, struct blk_mq_hw_ctx, dispatch_wait);
1116
1117 spin_lock(&hctx->dispatch_wait_lock);
1118 if (!list_empty(&wait->entry)) {
1119 struct sbitmap_queue *sbq;
1120
1121 list_del_init(&wait->entry);
1122 sbq = hctx->tags->bitmap_tags;
1123 atomic_dec(&sbq->ws_active);
1124 }
1125 spin_unlock(&hctx->dispatch_wait_lock);
1126
1127 blk_mq_run_hw_queue(hctx, true);
1128 return 1;
1129}
1130
1131
1132
1133
1134
1135
1136
1137static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx *hctx,
1138 struct request *rq)
1139{
1140 struct sbitmap_queue *sbq = hctx->tags->bitmap_tags;
1141 struct wait_queue_head *wq;
1142 wait_queue_entry_t *wait;
1143 bool ret;
1144
1145 if (!(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) {
1146 blk_mq_sched_mark_restart_hctx(hctx);
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156 return blk_mq_get_driver_tag(rq);
1157 }
1158
1159 wait = &hctx->dispatch_wait;
1160 if (!list_empty_careful(&wait->entry))
1161 return false;
1162
1163 wq = &bt_wait_ptr(sbq, hctx)->wait;
1164
1165 spin_lock_irq(&wq->lock);
1166 spin_lock(&hctx->dispatch_wait_lock);
1167 if (!list_empty(&wait->entry)) {
1168 spin_unlock(&hctx->dispatch_wait_lock);
1169 spin_unlock_irq(&wq->lock);
1170 return false;
1171 }
1172
1173 atomic_inc(&sbq->ws_active);
1174 wait->flags &= ~WQ_FLAG_EXCLUSIVE;
1175 __add_wait_queue(wq, wait);
1176
1177
1178
1179
1180
1181
1182 ret = blk_mq_get_driver_tag(rq);
1183 if (!ret) {
1184 spin_unlock(&hctx->dispatch_wait_lock);
1185 spin_unlock_irq(&wq->lock);
1186 return false;
1187 }
1188
1189
1190
1191
1192
1193 list_del_init(&wait->entry);
1194 atomic_dec(&sbq->ws_active);
1195 spin_unlock(&hctx->dispatch_wait_lock);
1196 spin_unlock_irq(&wq->lock);
1197
1198 return true;
1199}
1200
1201#define BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT 8
1202#define BLK_MQ_DISPATCH_BUSY_EWMA_FACTOR 4
1203
1204
1205
1206
1207
1208
1209
1210static void blk_mq_update_dispatch_busy(struct blk_mq_hw_ctx *hctx, bool busy)
1211{
1212 unsigned int ewma;
1213
1214 ewma = hctx->dispatch_busy;
1215
1216 if (!ewma && !busy)
1217 return;
1218
1219 ewma *= BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT - 1;
1220 if (busy)
1221 ewma += 1 << BLK_MQ_DISPATCH_BUSY_EWMA_FACTOR;
1222 ewma /= BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT;
1223
1224 hctx->dispatch_busy = ewma;
1225}
1226
1227#define BLK_MQ_RESOURCE_DELAY 3
1228
1229static void blk_mq_handle_dev_resource(struct request *rq,
1230 struct list_head *list)
1231{
1232 struct request *next =
1233 list_first_entry_or_null(list, struct request, queuelist);
1234
1235
1236
1237
1238
1239 if (next)
1240 blk_mq_put_driver_tag(next);
1241
1242 list_add(&rq->queuelist, list);
1243 __blk_mq_requeue_request(rq);
1244}
1245
1246static void blk_mq_handle_zone_resource(struct request *rq,
1247 struct list_head *zone_list)
1248{
1249
1250
1251
1252
1253
1254
1255 list_add(&rq->queuelist, zone_list);
1256 __blk_mq_requeue_request(rq);
1257}
1258
1259enum prep_dispatch {
1260 PREP_DISPATCH_OK,
1261 PREP_DISPATCH_NO_TAG,
1262 PREP_DISPATCH_NO_BUDGET,
1263};
1264
1265static enum prep_dispatch blk_mq_prep_dispatch_rq(struct request *rq,
1266 bool need_budget)
1267{
1268 struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
1269 int budget_token = -1;
1270
1271 if (need_budget) {
1272 budget_token = blk_mq_get_dispatch_budget(rq->q);
1273 if (budget_token < 0) {
1274 blk_mq_put_driver_tag(rq);
1275 return PREP_DISPATCH_NO_BUDGET;
1276 }
1277 blk_mq_set_rq_budget_token(rq, budget_token);
1278 }
1279
1280 if (!blk_mq_get_driver_tag(rq)) {
1281
1282
1283
1284
1285
1286
1287
1288 if (!blk_mq_mark_tag_wait(hctx, rq)) {
1289
1290
1291
1292
1293 if (need_budget)
1294 blk_mq_put_dispatch_budget(rq->q, budget_token);
1295 return PREP_DISPATCH_NO_TAG;
1296 }
1297 }
1298
1299 return PREP_DISPATCH_OK;
1300}
1301
1302
1303static void blk_mq_release_budgets(struct request_queue *q,
1304 struct list_head *list)
1305{
1306 struct request *rq;
1307
1308 list_for_each_entry(rq, list, queuelist) {
1309 int budget_token = blk_mq_get_rq_budget_token(rq);
1310
1311 if (budget_token >= 0)
1312 blk_mq_put_dispatch_budget(q, budget_token);
1313 }
1314}
1315
1316
1317
1318
1319bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list,
1320 unsigned int nr_budgets)
1321{
1322 enum prep_dispatch prep;
1323 struct request_queue *q = hctx->queue;
1324 struct request *rq, *nxt;
1325 int errors, queued;
1326 blk_status_t ret = BLK_STS_OK;
1327 LIST_HEAD(zone_list);
1328 bool needs_resource = false;
1329
1330 if (list_empty(list))
1331 return false;
1332
1333
1334
1335
1336 errors = queued = 0;
1337 do {
1338 struct blk_mq_queue_data bd;
1339
1340 rq = list_first_entry(list, struct request, queuelist);
1341
1342 WARN_ON_ONCE(hctx != rq->mq_hctx);
1343 prep = blk_mq_prep_dispatch_rq(rq, !nr_budgets);
1344 if (prep != PREP_DISPATCH_OK)
1345 break;
1346
1347 list_del_init(&rq->queuelist);
1348
1349 bd.rq = rq;
1350
1351
1352
1353
1354
1355 if (list_empty(list))
1356 bd.last = true;
1357 else {
1358 nxt = list_first_entry(list, struct request, queuelist);
1359 bd.last = !blk_mq_get_driver_tag(nxt);
1360 }
1361
1362
1363
1364
1365
1366 if (nr_budgets)
1367 nr_budgets--;
1368 ret = q->mq_ops->queue_rq(hctx, &bd);
1369 switch (ret) {
1370 case BLK_STS_OK:
1371 queued++;
1372 break;
1373 case BLK_STS_RESOURCE:
1374 needs_resource = true;
1375 fallthrough;
1376 case BLK_STS_DEV_RESOURCE:
1377 blk_mq_handle_dev_resource(rq, list);
1378 goto out;
1379 case BLK_STS_ZONE_RESOURCE:
1380
1381
1382
1383
1384
1385 blk_mq_handle_zone_resource(rq, &zone_list);
1386 needs_resource = true;
1387 break;
1388 default:
1389 errors++;
1390 blk_mq_end_request(rq, ret);
1391 }
1392 } while (!list_empty(list));
1393out:
1394 if (!list_empty(&zone_list))
1395 list_splice_tail_init(&zone_list, list);
1396
1397 hctx->dispatched[queued_to_index(queued)]++;
1398
1399
1400
1401
1402 if ((!list_empty(list) || errors) && q->mq_ops->commit_rqs && queued)
1403 q->mq_ops->commit_rqs(hctx);
1404
1405
1406
1407
1408 if (!list_empty(list)) {
1409 bool needs_restart;
1410
1411 bool no_tag = prep == PREP_DISPATCH_NO_TAG &&
1412 (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED);
1413
1414 if (nr_budgets)
1415 blk_mq_release_budgets(q, list);
1416
1417 spin_lock(&hctx->lock);
1418 list_splice_tail_init(list, &hctx->dispatch);
1419 spin_unlock(&hctx->lock);
1420
1421
1422
1423
1424
1425
1426
1427
1428 smp_mb();
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456 needs_restart = blk_mq_sched_needs_restart(hctx);
1457 if (prep == PREP_DISPATCH_NO_BUDGET)
1458 needs_resource = true;
1459 if (!needs_restart ||
1460 (no_tag && list_empty_careful(&hctx->dispatch_wait.entry)))
1461 blk_mq_run_hw_queue(hctx, true);
1462 else if (needs_restart && needs_resource)
1463 blk_mq_delay_run_hw_queue(hctx, BLK_MQ_RESOURCE_DELAY);
1464
1465 blk_mq_update_dispatch_busy(hctx, true);
1466 return false;
1467 } else
1468 blk_mq_update_dispatch_busy(hctx, false);
1469
1470 return (queued + errors) != 0;
1471}
1472
1473
1474
1475
1476
1477
1478
1479static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
1480{
1481 int srcu_idx;
1482
1483
1484
1485
1486
1487 WARN_ON_ONCE(in_interrupt());
1488
1489 might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING);
1490
1491 hctx_lock(hctx, &srcu_idx);
1492 blk_mq_sched_dispatch_requests(hctx);
1493 hctx_unlock(hctx, srcu_idx);
1494}
1495
1496static inline int blk_mq_first_mapped_cpu(struct blk_mq_hw_ctx *hctx)
1497{
1498 int cpu = cpumask_first_and(hctx->cpumask, cpu_online_mask);
1499
1500 if (cpu >= nr_cpu_ids)
1501 cpu = cpumask_first(hctx->cpumask);
1502 return cpu;
1503}
1504
1505
1506
1507
1508
1509
1510
1511static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx)
1512{
1513 bool tried = false;
1514 int next_cpu = hctx->next_cpu;
1515
1516 if (hctx->queue->nr_hw_queues == 1)
1517 return WORK_CPU_UNBOUND;
1518
1519 if (--hctx->next_cpu_batch <= 0) {
1520select_cpu:
1521 next_cpu = cpumask_next_and(next_cpu, hctx->cpumask,
1522 cpu_online_mask);
1523 if (next_cpu >= nr_cpu_ids)
1524 next_cpu = blk_mq_first_mapped_cpu(hctx);
1525 hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
1526 }
1527
1528
1529
1530
1531
1532 if (!cpu_online(next_cpu)) {
1533 if (!tried) {
1534 tried = true;
1535 goto select_cpu;
1536 }
1537
1538
1539
1540
1541
1542 hctx->next_cpu = next_cpu;
1543 hctx->next_cpu_batch = 1;
1544 return WORK_CPU_UNBOUND;
1545 }
1546
1547 hctx->next_cpu = next_cpu;
1548 return next_cpu;
1549}
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async,
1561 unsigned long msecs)
1562{
1563 if (unlikely(blk_mq_hctx_stopped(hctx)))
1564 return;
1565
1566 if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) {
1567 int cpu = get_cpu();
1568 if (cpumask_test_cpu(cpu, hctx->cpumask)) {
1569 __blk_mq_run_hw_queue(hctx);
1570 put_cpu();
1571 return;
1572 }
1573
1574 put_cpu();
1575 }
1576
1577 kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work,
1578 msecs_to_jiffies(msecs));
1579}
1580
1581
1582
1583
1584
1585
1586
1587
1588void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs)
1589{
1590 __blk_mq_delay_run_hw_queue(hctx, true, msecs);
1591}
1592EXPORT_SYMBOL(blk_mq_delay_run_hw_queue);
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
1604{
1605 int srcu_idx;
1606 bool need_run;
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616 hctx_lock(hctx, &srcu_idx);
1617 need_run = !blk_queue_quiesced(hctx->queue) &&
1618 blk_mq_hctx_has_pending(hctx);
1619 hctx_unlock(hctx, srcu_idx);
1620
1621 if (need_run)
1622 __blk_mq_delay_run_hw_queue(hctx, async, 0);
1623}
1624EXPORT_SYMBOL(blk_mq_run_hw_queue);
1625
1626
1627
1628
1629
1630static bool blk_mq_has_sqsched(struct request_queue *q)
1631{
1632 struct elevator_queue *e = q->elevator;
1633
1634 if (e && e->type->ops.dispatch_request &&
1635 !(e->type->elevator_features & ELEVATOR_F_MQ_AWARE))
1636 return true;
1637 return false;
1638}
1639
1640
1641
1642
1643
1644static struct blk_mq_hw_ctx *blk_mq_get_sq_hctx(struct request_queue *q)
1645{
1646 struct blk_mq_hw_ctx *hctx;
1647
1648
1649
1650
1651
1652
1653
1654
1655 hctx = blk_mq_map_queue_type(q, HCTX_TYPE_DEFAULT,
1656 raw_smp_processor_id());
1657 if (!blk_mq_hctx_stopped(hctx))
1658 return hctx;
1659 return NULL;
1660}
1661
1662
1663
1664
1665
1666
1667void blk_mq_run_hw_queues(struct request_queue *q, bool async)
1668{
1669 struct blk_mq_hw_ctx *hctx, *sq_hctx;
1670 int i;
1671
1672 sq_hctx = NULL;
1673 if (blk_mq_has_sqsched(q))
1674 sq_hctx = blk_mq_get_sq_hctx(q);
1675 queue_for_each_hw_ctx(q, hctx, i) {
1676 if (blk_mq_hctx_stopped(hctx))
1677 continue;
1678
1679
1680
1681
1682
1683 if (!sq_hctx || sq_hctx == hctx ||
1684 !list_empty_careful(&hctx->dispatch))
1685 blk_mq_run_hw_queue(hctx, async);
1686 }
1687}
1688EXPORT_SYMBOL(blk_mq_run_hw_queues);
1689
1690
1691
1692
1693
1694
1695void blk_mq_delay_run_hw_queues(struct request_queue *q, unsigned long msecs)
1696{
1697 struct blk_mq_hw_ctx *hctx, *sq_hctx;
1698 int i;
1699
1700 sq_hctx = NULL;
1701 if (blk_mq_has_sqsched(q))
1702 sq_hctx = blk_mq_get_sq_hctx(q);
1703 queue_for_each_hw_ctx(q, hctx, i) {
1704 if (blk_mq_hctx_stopped(hctx))
1705 continue;
1706
1707
1708
1709
1710
1711 if (!sq_hctx || sq_hctx == hctx ||
1712 !list_empty_careful(&hctx->dispatch))
1713 blk_mq_delay_run_hw_queue(hctx, msecs);
1714 }
1715}
1716EXPORT_SYMBOL(blk_mq_delay_run_hw_queues);
1717
1718
1719
1720
1721
1722
1723
1724
1725bool blk_mq_queue_stopped(struct request_queue *q)
1726{
1727 struct blk_mq_hw_ctx *hctx;
1728 int i;
1729
1730 queue_for_each_hw_ctx(q, hctx, i)
1731 if (blk_mq_hctx_stopped(hctx))
1732 return true;
1733
1734 return false;
1735}
1736EXPORT_SYMBOL(blk_mq_queue_stopped);
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx)
1748{
1749 cancel_delayed_work(&hctx->run_work);
1750
1751 set_bit(BLK_MQ_S_STOPPED, &hctx->state);
1752}
1753EXPORT_SYMBOL(blk_mq_stop_hw_queue);
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764void blk_mq_stop_hw_queues(struct request_queue *q)
1765{
1766 struct blk_mq_hw_ctx *hctx;
1767 int i;
1768
1769 queue_for_each_hw_ctx(q, hctx, i)
1770 blk_mq_stop_hw_queue(hctx);
1771}
1772EXPORT_SYMBOL(blk_mq_stop_hw_queues);
1773
1774void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx)
1775{
1776 clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
1777
1778 blk_mq_run_hw_queue(hctx, false);
1779}
1780EXPORT_SYMBOL(blk_mq_start_hw_queue);
1781
1782void blk_mq_start_hw_queues(struct request_queue *q)
1783{
1784 struct blk_mq_hw_ctx *hctx;
1785 int i;
1786
1787 queue_for_each_hw_ctx(q, hctx, i)
1788 blk_mq_start_hw_queue(hctx);
1789}
1790EXPORT_SYMBOL(blk_mq_start_hw_queues);
1791
1792void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
1793{
1794 if (!blk_mq_hctx_stopped(hctx))
1795 return;
1796
1797 clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
1798 blk_mq_run_hw_queue(hctx, async);
1799}
1800EXPORT_SYMBOL_GPL(blk_mq_start_stopped_hw_queue);
1801
1802void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async)
1803{
1804 struct blk_mq_hw_ctx *hctx;
1805 int i;
1806
1807 queue_for_each_hw_ctx(q, hctx, i)
1808 blk_mq_start_stopped_hw_queue(hctx, async);
1809}
1810EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues);
1811
1812static void blk_mq_run_work_fn(struct work_struct *work)
1813{
1814 struct blk_mq_hw_ctx *hctx;
1815
1816 hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work);
1817
1818
1819
1820
1821 if (blk_mq_hctx_stopped(hctx))
1822 return;
1823
1824 __blk_mq_run_hw_queue(hctx);
1825}
1826
1827static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx,
1828 struct request *rq,
1829 bool at_head)
1830{
1831 struct blk_mq_ctx *ctx = rq->mq_ctx;
1832 enum hctx_type type = hctx->type;
1833
1834 lockdep_assert_held(&ctx->lock);
1835
1836 trace_block_rq_insert(rq);
1837
1838 if (at_head)
1839 list_add(&rq->queuelist, &ctx->rq_lists[type]);
1840 else
1841 list_add_tail(&rq->queuelist, &ctx->rq_lists[type]);
1842}
1843
1844void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
1845 bool at_head)
1846{
1847 struct blk_mq_ctx *ctx = rq->mq_ctx;
1848
1849 lockdep_assert_held(&ctx->lock);
1850
1851 __blk_mq_insert_req_list(hctx, rq, at_head);
1852 blk_mq_hctx_mark_pending(hctx, ctx);
1853}
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864void blk_mq_request_bypass_insert(struct request *rq, bool at_head,
1865 bool run_queue)
1866{
1867 struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
1868
1869 spin_lock(&hctx->lock);
1870 if (at_head)
1871 list_add(&rq->queuelist, &hctx->dispatch);
1872 else
1873 list_add_tail(&rq->queuelist, &hctx->dispatch);
1874 spin_unlock(&hctx->lock);
1875
1876 if (run_queue)
1877 blk_mq_run_hw_queue(hctx, false);
1878}
1879
1880void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
1881 struct list_head *list)
1882
1883{
1884 struct request *rq;
1885 enum hctx_type type = hctx->type;
1886
1887
1888
1889
1890
1891 list_for_each_entry(rq, list, queuelist) {
1892 BUG_ON(rq->mq_ctx != ctx);
1893 trace_block_rq_insert(rq);
1894 }
1895
1896 spin_lock(&ctx->lock);
1897 list_splice_tail_init(list, &ctx->rq_lists[type]);
1898 blk_mq_hctx_mark_pending(hctx, ctx);
1899 spin_unlock(&ctx->lock);
1900}
1901
1902static int plug_rq_cmp(void *priv, const struct list_head *a,
1903 const struct list_head *b)
1904{
1905 struct request *rqa = container_of(a, struct request, queuelist);
1906 struct request *rqb = container_of(b, struct request, queuelist);
1907
1908 if (rqa->mq_ctx != rqb->mq_ctx)
1909 return rqa->mq_ctx > rqb->mq_ctx;
1910 if (rqa->mq_hctx != rqb->mq_hctx)
1911 return rqa->mq_hctx > rqb->mq_hctx;
1912
1913 return blk_rq_pos(rqa) > blk_rq_pos(rqb);
1914}
1915
1916void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
1917{
1918 LIST_HEAD(list);
1919
1920 if (list_empty(&plug->mq_list))
1921 return;
1922 list_splice_init(&plug->mq_list, &list);
1923
1924 if (plug->rq_count > 2 && plug->multiple_queues)
1925 list_sort(NULL, &list, plug_rq_cmp);
1926
1927 plug->rq_count = 0;
1928
1929 do {
1930 struct list_head rq_list;
1931 struct request *rq, *head_rq = list_entry_rq(list.next);
1932 struct list_head *pos = &head_rq->queuelist;
1933 struct blk_mq_hw_ctx *this_hctx = head_rq->mq_hctx;
1934 struct blk_mq_ctx *this_ctx = head_rq->mq_ctx;
1935 unsigned int depth = 1;
1936
1937 list_for_each_continue(pos, &list) {
1938 rq = list_entry_rq(pos);
1939 BUG_ON(!rq->q);
1940 if (rq->mq_hctx != this_hctx || rq->mq_ctx != this_ctx)
1941 break;
1942 depth++;
1943 }
1944
1945 list_cut_before(&rq_list, &list, pos);
1946 trace_block_unplug(head_rq->q, depth, !from_schedule);
1947 blk_mq_sched_insert_requests(this_hctx, this_ctx, &rq_list,
1948 from_schedule);
1949 } while(!list_empty(&list));
1950}
1951
1952static void blk_mq_bio_to_request(struct request *rq, struct bio *bio,
1953 unsigned int nr_segs)
1954{
1955 int err;
1956
1957 if (bio->bi_opf & REQ_RAHEAD)
1958 rq->cmd_flags |= REQ_FAILFAST_MASK;
1959
1960 rq->__sector = bio->bi_iter.bi_sector;
1961 rq->write_hint = bio->bi_write_hint;
1962 blk_rq_bio_prep(rq, bio, nr_segs);
1963
1964
1965 err = blk_crypto_rq_bio_prep(rq, bio, GFP_NOIO);
1966 WARN_ON_ONCE(err);
1967
1968 blk_account_io_start(rq);
1969}
1970
1971static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx,
1972 struct request *rq,
1973 blk_qc_t *cookie, bool last)
1974{
1975 struct request_queue *q = rq->q;
1976 struct blk_mq_queue_data bd = {
1977 .rq = rq,
1978 .last = last,
1979 };
1980 blk_qc_t new_cookie;
1981 blk_status_t ret;
1982
1983 new_cookie = request_to_qc_t(hctx, rq);
1984
1985
1986
1987
1988
1989
1990 ret = q->mq_ops->queue_rq(hctx, &bd);
1991 switch (ret) {
1992 case BLK_STS_OK:
1993 blk_mq_update_dispatch_busy(hctx, false);
1994 *cookie = new_cookie;
1995 break;
1996 case BLK_STS_RESOURCE:
1997 case BLK_STS_DEV_RESOURCE:
1998 blk_mq_update_dispatch_busy(hctx, true);
1999 __blk_mq_requeue_request(rq);
2000 break;
2001 default:
2002 blk_mq_update_dispatch_busy(hctx, false);
2003 *cookie = BLK_QC_T_NONE;
2004 break;
2005 }
2006
2007 return ret;
2008}
2009
2010static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
2011 struct request *rq,
2012 blk_qc_t *cookie,
2013 bool bypass_insert, bool last)
2014{
2015 struct request_queue *q = rq->q;
2016 bool run_queue = true;
2017 int budget_token;
2018
2019
2020
2021
2022
2023
2024
2025
2026 if (blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(q)) {
2027 run_queue = false;
2028 bypass_insert = false;
2029 goto insert;
2030 }
2031
2032 if (q->elevator && !bypass_insert)
2033 goto insert;
2034
2035 budget_token = blk_mq_get_dispatch_budget(q);
2036 if (budget_token < 0)
2037 goto insert;
2038
2039 blk_mq_set_rq_budget_token(rq, budget_token);
2040
2041 if (!blk_mq_get_driver_tag(rq)) {
2042 blk_mq_put_dispatch_budget(q, budget_token);
2043 goto insert;
2044 }
2045
2046 return __blk_mq_issue_directly(hctx, rq, cookie, last);
2047insert:
2048 if (bypass_insert)
2049 return BLK_STS_RESOURCE;
2050
2051 blk_mq_sched_insert_request(rq, false, run_queue, false);
2052
2053 return BLK_STS_OK;
2054}
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
2068 struct request *rq, blk_qc_t *cookie)
2069{
2070 blk_status_t ret;
2071 int srcu_idx;
2072
2073 might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING);
2074
2075 hctx_lock(hctx, &srcu_idx);
2076
2077 ret = __blk_mq_try_issue_directly(hctx, rq, cookie, false, true);
2078 if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE)
2079 blk_mq_request_bypass_insert(rq, false, true);
2080 else if (ret != BLK_STS_OK)
2081 blk_mq_end_request(rq, ret);
2082
2083 hctx_unlock(hctx, srcu_idx);
2084}
2085
2086blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last)
2087{
2088 blk_status_t ret;
2089 int srcu_idx;
2090 blk_qc_t unused_cookie;
2091 struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
2092
2093 hctx_lock(hctx, &srcu_idx);
2094 ret = __blk_mq_try_issue_directly(hctx, rq, &unused_cookie, true, last);
2095 hctx_unlock(hctx, srcu_idx);
2096
2097 return ret;
2098}
2099
2100void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
2101 struct list_head *list)
2102{
2103 int queued = 0;
2104 int errors = 0;
2105
2106 while (!list_empty(list)) {
2107 blk_status_t ret;
2108 struct request *rq = list_first_entry(list, struct request,
2109 queuelist);
2110
2111 list_del_init(&rq->queuelist);
2112 ret = blk_mq_request_issue_directly(rq, list_empty(list));
2113 if (ret != BLK_STS_OK) {
2114 if (ret == BLK_STS_RESOURCE ||
2115 ret == BLK_STS_DEV_RESOURCE) {
2116 blk_mq_request_bypass_insert(rq, false,
2117 list_empty(list));
2118 break;
2119 }
2120 blk_mq_end_request(rq, ret);
2121 errors++;
2122 } else
2123 queued++;
2124 }
2125
2126
2127
2128
2129
2130
2131 if ((!list_empty(list) || errors) &&
2132 hctx->queue->mq_ops->commit_rqs && queued)
2133 hctx->queue->mq_ops->commit_rqs(hctx);
2134}
2135
2136static void blk_add_rq_to_plug(struct blk_plug *plug, struct request *rq)
2137{
2138 list_add_tail(&rq->queuelist, &plug->mq_list);
2139 plug->rq_count++;
2140 if (!plug->multiple_queues && !list_is_singular(&plug->mq_list)) {
2141 struct request *tmp;
2142
2143 tmp = list_first_entry(&plug->mq_list, struct request,
2144 queuelist);
2145 if (tmp->q != rq->q)
2146 plug->multiple_queues = true;
2147 }
2148}
2149
2150
2151
2152
2153
2154
2155static inline unsigned short blk_plug_max_rq_count(struct blk_plug *plug)
2156{
2157 if (plug->multiple_queues)
2158 return BLK_MAX_REQUEST_COUNT * 4;
2159 return BLK_MAX_REQUEST_COUNT;
2160}
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177blk_qc_t blk_mq_submit_bio(struct bio *bio)
2178{
2179 struct request_queue *q = bio->bi_bdev->bd_disk->queue;
2180 const int is_sync = op_is_sync(bio->bi_opf);
2181 const int is_flush_fua = op_is_flush(bio->bi_opf);
2182 struct blk_mq_alloc_data data = {
2183 .q = q,
2184 };
2185 struct request *rq;
2186 struct blk_plug *plug;
2187 struct request *same_queue_rq = NULL;
2188 unsigned int nr_segs;
2189 blk_qc_t cookie;
2190 blk_status_t ret;
2191 bool hipri;
2192
2193 blk_queue_bounce(q, &bio);
2194 __blk_queue_split(&bio, &nr_segs);
2195
2196 if (!bio_integrity_prep(bio))
2197 goto queue_exit;
2198
2199 if (!is_flush_fua && !blk_queue_nomerges(q) &&
2200 blk_attempt_plug_merge(q, bio, nr_segs, &same_queue_rq))
2201 goto queue_exit;
2202
2203 if (blk_mq_sched_bio_merge(q, bio, nr_segs))
2204 goto queue_exit;
2205
2206 rq_qos_throttle(q, bio);
2207
2208 hipri = bio->bi_opf & REQ_HIPRI;
2209
2210 data.cmd_flags = bio->bi_opf;
2211 rq = __blk_mq_alloc_request(&data);
2212 if (unlikely(!rq)) {
2213 rq_qos_cleanup(q, bio);
2214 if (bio->bi_opf & REQ_NOWAIT)
2215 bio_wouldblock_error(bio);
2216 goto queue_exit;
2217 }
2218
2219 trace_block_getrq(bio);
2220
2221 rq_qos_track(q, rq, bio);
2222
2223 cookie = request_to_qc_t(data.hctx, rq);
2224
2225 blk_mq_bio_to_request(rq, bio, nr_segs);
2226
2227 ret = blk_crypto_init_request(rq);
2228 if (ret != BLK_STS_OK) {
2229 bio->bi_status = ret;
2230 bio_endio(bio);
2231 blk_mq_free_request(rq);
2232 return BLK_QC_T_NONE;
2233 }
2234
2235 plug = blk_mq_plug(q, bio);
2236 if (unlikely(is_flush_fua)) {
2237
2238 blk_insert_flush(rq);
2239 blk_mq_run_hw_queue(data.hctx, true);
2240 } else if (plug && (q->nr_hw_queues == 1 ||
2241 blk_mq_is_sbitmap_shared(rq->mq_hctx->flags) ||
2242 q->mq_ops->commit_rqs || !blk_queue_nonrot(q))) {
2243
2244
2245
2246
2247
2248
2249
2250 unsigned int request_count = plug->rq_count;
2251 struct request *last = NULL;
2252
2253 if (!request_count)
2254 trace_block_plug(q);
2255 else
2256 last = list_entry_rq(plug->mq_list.prev);
2257
2258 if (request_count >= blk_plug_max_rq_count(plug) || (last &&
2259 blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE)) {
2260 blk_flush_plug_list(plug, false);
2261 trace_block_plug(q);
2262 }
2263
2264 blk_add_rq_to_plug(plug, rq);
2265 } else if (q->elevator) {
2266
2267 blk_mq_sched_insert_request(rq, false, true, true);
2268 } else if (plug && !blk_queue_nomerges(q)) {
2269
2270
2271
2272
2273
2274
2275
2276 if (list_empty(&plug->mq_list))
2277 same_queue_rq = NULL;
2278 if (same_queue_rq) {
2279 list_del_init(&same_queue_rq->queuelist);
2280 plug->rq_count--;
2281 }
2282 blk_add_rq_to_plug(plug, rq);
2283 trace_block_plug(q);
2284
2285 if (same_queue_rq) {
2286 data.hctx = same_queue_rq->mq_hctx;
2287 trace_block_unplug(q, 1, true);
2288 blk_mq_try_issue_directly(data.hctx, same_queue_rq,
2289 &cookie);
2290 }
2291 } else if ((q->nr_hw_queues > 1 && is_sync) ||
2292 !data.hctx->dispatch_busy) {
2293
2294
2295
2296
2297 blk_mq_try_issue_directly(data.hctx, rq, &cookie);
2298 } else {
2299
2300 blk_mq_sched_insert_request(rq, false, true, true);
2301 }
2302
2303 if (!hipri)
2304 return BLK_QC_T_NONE;
2305 return cookie;
2306queue_exit:
2307 blk_queue_exit(q);
2308 return BLK_QC_T_NONE;
2309}
2310
2311static size_t order_to_size(unsigned int order)
2312{
2313 return (size_t)PAGE_SIZE << order;
2314}
2315
2316
2317static void blk_mq_clear_rq_mapping(struct blk_mq_tag_set *set,
2318 struct blk_mq_tags *tags, unsigned int hctx_idx)
2319{
2320 struct blk_mq_tags *drv_tags = set->tags[hctx_idx];
2321 struct page *page;
2322 unsigned long flags;
2323
2324 list_for_each_entry(page, &tags->page_list, lru) {
2325 unsigned long start = (unsigned long)page_address(page);
2326 unsigned long end = start + order_to_size(page->private);
2327 int i;
2328
2329 for (i = 0; i < set->queue_depth; i++) {
2330 struct request *rq = drv_tags->rqs[i];
2331 unsigned long rq_addr = (unsigned long)rq;
2332
2333 if (rq_addr >= start && rq_addr < end) {
2334 WARN_ON_ONCE(refcount_read(&rq->ref) != 0);
2335 cmpxchg(&drv_tags->rqs[i], rq, NULL);
2336 }
2337 }
2338 }
2339
2340
2341
2342
2343
2344
2345
2346 spin_lock_irqsave(&drv_tags->lock, flags);
2347 spin_unlock_irqrestore(&drv_tags->lock, flags);
2348}
2349
2350void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
2351 unsigned int hctx_idx)
2352{
2353 struct page *page;
2354
2355 if (tags->rqs && set->ops->exit_request) {
2356 int i;
2357
2358 for (i = 0; i < tags->nr_tags; i++) {
2359 struct request *rq = tags->static_rqs[i];
2360
2361 if (!rq)
2362 continue;
2363 set->ops->exit_request(set, rq, hctx_idx);
2364 tags->static_rqs[i] = NULL;
2365 }
2366 }
2367
2368 blk_mq_clear_rq_mapping(set, tags, hctx_idx);
2369
2370 while (!list_empty(&tags->page_list)) {
2371 page = list_first_entry(&tags->page_list, struct page, lru);
2372 list_del_init(&page->lru);
2373
2374
2375
2376
2377 kmemleak_free(page_address(page));
2378 __free_pages(page, page->private);
2379 }
2380}
2381
2382void blk_mq_free_rq_map(struct blk_mq_tags *tags, unsigned int flags)
2383{
2384 kfree(tags->rqs);
2385 tags->rqs = NULL;
2386 kfree(tags->static_rqs);
2387 tags->static_rqs = NULL;
2388
2389 blk_mq_free_tags(tags, flags);
2390}
2391
2392struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
2393 unsigned int hctx_idx,
2394 unsigned int nr_tags,
2395 unsigned int reserved_tags,
2396 unsigned int flags)
2397{
2398 struct blk_mq_tags *tags;
2399 int node;
2400
2401 node = blk_mq_hw_queue_to_node(&set->map[HCTX_TYPE_DEFAULT], hctx_idx);
2402 if (node == NUMA_NO_NODE)
2403 node = set->numa_node;
2404
2405 tags = blk_mq_init_tags(nr_tags, reserved_tags, node, flags);
2406 if (!tags)
2407 return NULL;
2408
2409 tags->rqs = kcalloc_node(nr_tags, sizeof(struct request *),
2410 GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY,
2411 node);
2412 if (!tags->rqs) {
2413 blk_mq_free_tags(tags, flags);
2414 return NULL;
2415 }
2416
2417 tags->static_rqs = kcalloc_node(nr_tags, sizeof(struct request *),
2418 GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY,
2419 node);
2420 if (!tags->static_rqs) {
2421 kfree(tags->rqs);
2422 blk_mq_free_tags(tags, flags);
2423 return NULL;
2424 }
2425
2426 return tags;
2427}
2428
2429static int blk_mq_init_request(struct blk_mq_tag_set *set, struct request *rq,
2430 unsigned int hctx_idx, int node)
2431{
2432 int ret;
2433
2434 if (set->ops->init_request) {
2435 ret = set->ops->init_request(set, rq, hctx_idx, node);
2436 if (ret)
2437 return ret;
2438 }
2439
2440 WRITE_ONCE(rq->state, MQ_RQ_IDLE);
2441 return 0;
2442}
2443
2444int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
2445 unsigned int hctx_idx, unsigned int depth)
2446{
2447 unsigned int i, j, entries_per_page, max_order = 4;
2448 size_t rq_size, left;
2449 int node;
2450
2451 node = blk_mq_hw_queue_to_node(&set->map[HCTX_TYPE_DEFAULT], hctx_idx);
2452 if (node == NUMA_NO_NODE)
2453 node = set->numa_node;
2454
2455 INIT_LIST_HEAD(&tags->page_list);
2456
2457
2458
2459
2460
2461 rq_size = round_up(sizeof(struct request) + set->cmd_size,
2462 cache_line_size());
2463 left = rq_size * depth;
2464
2465 for (i = 0; i < depth; ) {
2466 int this_order = max_order;
2467 struct page *page;
2468 int to_do;
2469 void *p;
2470
2471 while (this_order && left < order_to_size(this_order - 1))
2472 this_order--;
2473
2474 do {
2475 page = alloc_pages_node(node,
2476 GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO,
2477 this_order);
2478 if (page)
2479 break;
2480 if (!this_order--)
2481 break;
2482 if (order_to_size(this_order) < rq_size)
2483 break;
2484 } while (1);
2485
2486 if (!page)
2487 goto fail;
2488
2489 page->private = this_order;
2490 list_add_tail(&page->lru, &tags->page_list);
2491
2492 p = page_address(page);
2493
2494
2495
2496
2497 kmemleak_alloc(p, order_to_size(this_order), 1, GFP_NOIO);
2498 entries_per_page = order_to_size(this_order) / rq_size;
2499 to_do = min(entries_per_page, depth - i);
2500 left -= to_do * rq_size;
2501 for (j = 0; j < to_do; j++) {
2502 struct request *rq = p;
2503
2504 tags->static_rqs[i] = rq;
2505 if (blk_mq_init_request(set, rq, hctx_idx, node)) {
2506 tags->static_rqs[i] = NULL;
2507 goto fail;
2508 }
2509
2510 p += rq_size;
2511 i++;
2512 }
2513 }
2514 return 0;
2515
2516fail:
2517 blk_mq_free_rqs(set, tags, hctx_idx);
2518 return -ENOMEM;
2519}
2520
2521struct rq_iter_data {
2522 struct blk_mq_hw_ctx *hctx;
2523 bool has_rq;
2524};
2525
2526static bool blk_mq_has_request(struct request *rq, void *data, bool reserved)
2527{
2528 struct rq_iter_data *iter_data = data;
2529
2530 if (rq->mq_hctx != iter_data->hctx)
2531 return true;
2532 iter_data->has_rq = true;
2533 return false;
2534}
2535
2536static bool blk_mq_hctx_has_requests(struct blk_mq_hw_ctx *hctx)
2537{
2538 struct blk_mq_tags *tags = hctx->sched_tags ?
2539 hctx->sched_tags : hctx->tags;
2540 struct rq_iter_data data = {
2541 .hctx = hctx,
2542 };
2543
2544 blk_mq_all_tag_iter(tags, blk_mq_has_request, &data);
2545 return data.has_rq;
2546}
2547
2548static inline bool blk_mq_last_cpu_in_hctx(unsigned int cpu,
2549 struct blk_mq_hw_ctx *hctx)
2550{
2551 if (cpumask_next_and(-1, hctx->cpumask, cpu_online_mask) != cpu)
2552 return false;
2553 if (cpumask_next_and(cpu, hctx->cpumask, cpu_online_mask) < nr_cpu_ids)
2554 return false;
2555 return true;
2556}
2557
2558static int blk_mq_hctx_notify_offline(unsigned int cpu, struct hlist_node *node)
2559{
2560 struct blk_mq_hw_ctx *hctx = hlist_entry_safe(node,
2561 struct blk_mq_hw_ctx, cpuhp_online);
2562
2563 if (!cpumask_test_cpu(cpu, hctx->cpumask) ||
2564 !blk_mq_last_cpu_in_hctx(cpu, hctx))
2565 return 0;
2566
2567
2568
2569
2570
2571
2572
2573
2574 set_bit(BLK_MQ_S_INACTIVE, &hctx->state);
2575 smp_mb__after_atomic();
2576
2577
2578
2579
2580
2581
2582 if (percpu_ref_tryget(&hctx->queue->q_usage_counter)) {
2583 while (blk_mq_hctx_has_requests(hctx))
2584 msleep(5);
2585 percpu_ref_put(&hctx->queue->q_usage_counter);
2586 }
2587
2588 return 0;
2589}
2590
2591static int blk_mq_hctx_notify_online(unsigned int cpu, struct hlist_node *node)
2592{
2593 struct blk_mq_hw_ctx *hctx = hlist_entry_safe(node,
2594 struct blk_mq_hw_ctx, cpuhp_online);
2595
2596 if (cpumask_test_cpu(cpu, hctx->cpumask))
2597 clear_bit(BLK_MQ_S_INACTIVE, &hctx->state);
2598 return 0;
2599}
2600
2601
2602
2603
2604
2605
2606static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node)
2607{
2608 struct blk_mq_hw_ctx *hctx;
2609 struct blk_mq_ctx *ctx;
2610 LIST_HEAD(tmp);
2611 enum hctx_type type;
2612
2613 hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_dead);
2614 if (!cpumask_test_cpu(cpu, hctx->cpumask))
2615 return 0;
2616
2617 ctx = __blk_mq_get_ctx(hctx->queue, cpu);
2618 type = hctx->type;
2619
2620 spin_lock(&ctx->lock);
2621 if (!list_empty(&ctx->rq_lists[type])) {
2622 list_splice_init(&ctx->rq_lists[type], &tmp);
2623 blk_mq_hctx_clear_pending(hctx, ctx);
2624 }
2625 spin_unlock(&ctx->lock);
2626
2627 if (list_empty(&tmp))
2628 return 0;
2629
2630 spin_lock(&hctx->lock);
2631 list_splice_tail_init(&tmp, &hctx->dispatch);
2632 spin_unlock(&hctx->lock);
2633
2634 blk_mq_run_hw_queue(hctx, true);
2635 return 0;
2636}
2637
2638static void blk_mq_remove_cpuhp(struct blk_mq_hw_ctx *hctx)
2639{
2640 if (!(hctx->flags & BLK_MQ_F_STACKING))
2641 cpuhp_state_remove_instance_nocalls(CPUHP_AP_BLK_MQ_ONLINE,
2642 &hctx->cpuhp_online);
2643 cpuhp_state_remove_instance_nocalls(CPUHP_BLK_MQ_DEAD,
2644 &hctx->cpuhp_dead);
2645}
2646
2647
2648
2649
2650
2651static void blk_mq_clear_flush_rq_mapping(struct blk_mq_tags *tags,
2652 unsigned int queue_depth, struct request *flush_rq)
2653{
2654 int i;
2655 unsigned long flags;
2656
2657
2658 if (!tags)
2659 return;
2660
2661 WARN_ON_ONCE(refcount_read(&flush_rq->ref) != 0);
2662
2663 for (i = 0; i < queue_depth; i++)
2664 cmpxchg(&tags->rqs[i], flush_rq, NULL);
2665
2666
2667
2668
2669
2670
2671
2672 spin_lock_irqsave(&tags->lock, flags);
2673 spin_unlock_irqrestore(&tags->lock, flags);
2674}
2675
2676
2677static void blk_mq_exit_hctx(struct request_queue *q,
2678 struct blk_mq_tag_set *set,
2679 struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
2680{
2681 struct request *flush_rq = hctx->fq->flush_rq;
2682
2683 if (blk_mq_hw_queue_mapped(hctx))
2684 blk_mq_tag_idle(hctx);
2685
2686 blk_mq_clear_flush_rq_mapping(set->tags[hctx_idx],
2687 set->queue_depth, flush_rq);
2688 if (set->ops->exit_request)
2689 set->ops->exit_request(set, flush_rq, hctx_idx);
2690
2691 if (set->ops->exit_hctx)
2692 set->ops->exit_hctx(hctx, hctx_idx);
2693
2694 blk_mq_remove_cpuhp(hctx);
2695
2696 spin_lock(&q->unused_hctx_lock);
2697 list_add(&hctx->hctx_list, &q->unused_hctx_list);
2698 spin_unlock(&q->unused_hctx_lock);
2699}
2700
2701static void blk_mq_exit_hw_queues(struct request_queue *q,
2702 struct blk_mq_tag_set *set, int nr_queue)
2703{
2704 struct blk_mq_hw_ctx *hctx;
2705 unsigned int i;
2706
2707 queue_for_each_hw_ctx(q, hctx, i) {
2708 if (i == nr_queue)
2709 break;
2710 blk_mq_debugfs_unregister_hctx(hctx);
2711 blk_mq_exit_hctx(q, set, hctx, i);
2712 }
2713}
2714
2715static int blk_mq_hw_ctx_size(struct blk_mq_tag_set *tag_set)
2716{
2717 int hw_ctx_size = sizeof(struct blk_mq_hw_ctx);
2718
2719 BUILD_BUG_ON(ALIGN(offsetof(struct blk_mq_hw_ctx, srcu),
2720 __alignof__(struct blk_mq_hw_ctx)) !=
2721 sizeof(struct blk_mq_hw_ctx));
2722
2723 if (tag_set->flags & BLK_MQ_F_BLOCKING)
2724 hw_ctx_size += sizeof(struct srcu_struct);
2725
2726 return hw_ctx_size;
2727}
2728
2729static int blk_mq_init_hctx(struct request_queue *q,
2730 struct blk_mq_tag_set *set,
2731 struct blk_mq_hw_ctx *hctx, unsigned hctx_idx)
2732{
2733 hctx->queue_num = hctx_idx;
2734
2735 if (!(hctx->flags & BLK_MQ_F_STACKING))
2736 cpuhp_state_add_instance_nocalls(CPUHP_AP_BLK_MQ_ONLINE,
2737 &hctx->cpuhp_online);
2738 cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, &hctx->cpuhp_dead);
2739
2740 hctx->tags = set->tags[hctx_idx];
2741
2742 if (set->ops->init_hctx &&
2743 set->ops->init_hctx(hctx, set->driver_data, hctx_idx))
2744 goto unregister_cpu_notifier;
2745
2746 if (blk_mq_init_request(set, hctx->fq->flush_rq, hctx_idx,
2747 hctx->numa_node))
2748 goto exit_hctx;
2749 return 0;
2750
2751 exit_hctx:
2752 if (set->ops->exit_hctx)
2753 set->ops->exit_hctx(hctx, hctx_idx);
2754 unregister_cpu_notifier:
2755 blk_mq_remove_cpuhp(hctx);
2756 return -1;
2757}
2758
2759static struct blk_mq_hw_ctx *
2760blk_mq_alloc_hctx(struct request_queue *q, struct blk_mq_tag_set *set,
2761 int node)
2762{
2763 struct blk_mq_hw_ctx *hctx;
2764 gfp_t gfp = GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY;
2765
2766 hctx = kzalloc_node(blk_mq_hw_ctx_size(set), gfp, node);
2767 if (!hctx)
2768 goto fail_alloc_hctx;
2769
2770 if (!zalloc_cpumask_var_node(&hctx->cpumask, gfp, node))
2771 goto free_hctx;
2772
2773 atomic_set(&hctx->nr_active, 0);
2774 if (node == NUMA_NO_NODE)
2775 node = set->numa_node;
2776 hctx->numa_node = node;
2777
2778 INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn);
2779 spin_lock_init(&hctx->lock);
2780 INIT_LIST_HEAD(&hctx->dispatch);
2781 hctx->queue = q;
2782 hctx->flags = set->flags & ~BLK_MQ_F_TAG_QUEUE_SHARED;
2783
2784 INIT_LIST_HEAD(&hctx->hctx_list);
2785
2786
2787
2788
2789
2790 hctx->ctxs = kmalloc_array_node(nr_cpu_ids, sizeof(void *),
2791 gfp, node);
2792 if (!hctx->ctxs)
2793 goto free_cpumask;
2794
2795 if (sbitmap_init_node(&hctx->ctx_map, nr_cpu_ids, ilog2(8),
2796 gfp, node, false, false))
2797 goto free_ctxs;
2798 hctx->nr_ctx = 0;
2799
2800 spin_lock_init(&hctx->dispatch_wait_lock);
2801 init_waitqueue_func_entry(&hctx->dispatch_wait, blk_mq_dispatch_wake);
2802 INIT_LIST_HEAD(&hctx->dispatch_wait.entry);
2803
2804 hctx->fq = blk_alloc_flush_queue(hctx->numa_node, set->cmd_size, gfp);
2805 if (!hctx->fq)
2806 goto free_bitmap;
2807
2808 if (hctx->flags & BLK_MQ_F_BLOCKING)
2809 init_srcu_struct(hctx->srcu);
2810 blk_mq_hctx_kobj_init(hctx);
2811
2812 return hctx;
2813
2814 free_bitmap:
2815 sbitmap_free(&hctx->ctx_map);
2816 free_ctxs:
2817 kfree(hctx->ctxs);
2818 free_cpumask:
2819 free_cpumask_var(hctx->cpumask);
2820 free_hctx:
2821 kfree(hctx);
2822 fail_alloc_hctx:
2823 return NULL;
2824}
2825
2826static void blk_mq_init_cpu_queues(struct request_queue *q,
2827 unsigned int nr_hw_queues)
2828{
2829 struct blk_mq_tag_set *set = q->tag_set;
2830 unsigned int i, j;
2831
2832 for_each_possible_cpu(i) {
2833 struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i);
2834 struct blk_mq_hw_ctx *hctx;
2835 int k;
2836
2837 __ctx->cpu = i;
2838 spin_lock_init(&__ctx->lock);
2839 for (k = HCTX_TYPE_DEFAULT; k < HCTX_MAX_TYPES; k++)
2840 INIT_LIST_HEAD(&__ctx->rq_lists[k]);
2841
2842 __ctx->queue = q;
2843
2844
2845
2846
2847
2848 for (j = 0; j < set->nr_maps; j++) {
2849 hctx = blk_mq_map_queue_type(q, j, i);
2850 if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE)
2851 hctx->numa_node = cpu_to_node(i);
2852 }
2853 }
2854}
2855
2856static bool __blk_mq_alloc_map_and_request(struct blk_mq_tag_set *set,
2857 int hctx_idx)
2858{
2859 unsigned int flags = set->flags;
2860 int ret = 0;
2861
2862 set->tags[hctx_idx] = blk_mq_alloc_rq_map(set, hctx_idx,
2863 set->queue_depth, set->reserved_tags, flags);
2864 if (!set->tags[hctx_idx])
2865 return false;
2866
2867 ret = blk_mq_alloc_rqs(set, set->tags[hctx_idx], hctx_idx,
2868 set->queue_depth);
2869 if (!ret)
2870 return true;
2871
2872 blk_mq_free_rq_map(set->tags[hctx_idx], flags);
2873 set->tags[hctx_idx] = NULL;
2874 return false;
2875}
2876
2877static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set,
2878 unsigned int hctx_idx)
2879{
2880 unsigned int flags = set->flags;
2881
2882 if (set->tags && set->tags[hctx_idx]) {
2883 blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx);
2884 blk_mq_free_rq_map(set->tags[hctx_idx], flags);
2885 set->tags[hctx_idx] = NULL;
2886 }
2887}
2888
2889static void blk_mq_map_swqueue(struct request_queue *q)
2890{
2891 unsigned int i, j, hctx_idx;
2892 struct blk_mq_hw_ctx *hctx;
2893 struct blk_mq_ctx *ctx;
2894 struct blk_mq_tag_set *set = q->tag_set;
2895
2896 queue_for_each_hw_ctx(q, hctx, i) {
2897 cpumask_clear(hctx->cpumask);
2898 hctx->nr_ctx = 0;
2899 hctx->dispatch_from = NULL;
2900 }
2901
2902
2903
2904
2905
2906
2907 for_each_possible_cpu(i) {
2908
2909 ctx = per_cpu_ptr(q->queue_ctx, i);
2910 for (j = 0; j < set->nr_maps; j++) {
2911 if (!set->map[j].nr_queues) {
2912 ctx->hctxs[j] = blk_mq_map_queue_type(q,
2913 HCTX_TYPE_DEFAULT, i);
2914 continue;
2915 }
2916 hctx_idx = set->map[j].mq_map[i];
2917
2918 if (!set->tags[hctx_idx] &&
2919 !__blk_mq_alloc_map_and_request(set, hctx_idx)) {
2920
2921
2922
2923
2924
2925
2926 set->map[j].mq_map[i] = 0;
2927 }
2928
2929 hctx = blk_mq_map_queue_type(q, j, i);
2930 ctx->hctxs[j] = hctx;
2931
2932
2933
2934
2935
2936 if (cpumask_test_cpu(i, hctx->cpumask))
2937 continue;
2938
2939 cpumask_set_cpu(i, hctx->cpumask);
2940 hctx->type = j;
2941 ctx->index_hw[hctx->type] = hctx->nr_ctx;
2942 hctx->ctxs[hctx->nr_ctx++] = ctx;
2943
2944
2945
2946
2947
2948 BUG_ON(!hctx->nr_ctx);
2949 }
2950
2951 for (; j < HCTX_MAX_TYPES; j++)
2952 ctx->hctxs[j] = blk_mq_map_queue_type(q,
2953 HCTX_TYPE_DEFAULT, i);
2954 }
2955
2956 queue_for_each_hw_ctx(q, hctx, i) {
2957
2958
2959
2960
2961 if (!hctx->nr_ctx) {
2962
2963
2964
2965
2966 if (i && set->tags[i])
2967 blk_mq_free_map_and_requests(set, i);
2968
2969 hctx->tags = NULL;
2970 continue;
2971 }
2972
2973 hctx->tags = set->tags[i];
2974 WARN_ON(!hctx->tags);
2975
2976
2977
2978
2979
2980
2981 sbitmap_resize(&hctx->ctx_map, hctx->nr_ctx);
2982
2983
2984
2985
2986 hctx->next_cpu = blk_mq_first_mapped_cpu(hctx);
2987 hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
2988 }
2989}
2990
2991
2992
2993
2994
2995static void queue_set_hctx_shared(struct request_queue *q, bool shared)
2996{
2997 struct blk_mq_hw_ctx *hctx;
2998 int i;
2999
3000 queue_for_each_hw_ctx(q, hctx, i) {
3001 if (shared) {
3002 hctx->flags |= BLK_MQ_F_TAG_QUEUE_SHARED;
3003 } else {
3004 blk_mq_tag_idle(hctx);
3005 hctx->flags &= ~BLK_MQ_F_TAG_QUEUE_SHARED;
3006 }
3007 }
3008}
3009
3010static void blk_mq_update_tag_set_shared(struct blk_mq_tag_set *set,
3011 bool shared)
3012{
3013 struct request_queue *q;
3014
3015 lockdep_assert_held(&set->tag_list_lock);
3016
3017 list_for_each_entry(q, &set->tag_list, tag_set_list) {
3018 blk_mq_freeze_queue(q);
3019 queue_set_hctx_shared(q, shared);
3020 blk_mq_unfreeze_queue(q);
3021 }
3022}
3023
3024static void blk_mq_del_queue_tag_set(struct request_queue *q)
3025{
3026 struct blk_mq_tag_set *set = q->tag_set;
3027
3028 mutex_lock(&set->tag_list_lock);
3029 list_del(&q->tag_set_list);
3030 if (list_is_singular(&set->tag_list)) {
3031
3032 set->flags &= ~BLK_MQ_F_TAG_QUEUE_SHARED;
3033
3034 blk_mq_update_tag_set_shared(set, false);
3035 }
3036 mutex_unlock(&set->tag_list_lock);
3037 INIT_LIST_HEAD(&q->tag_set_list);
3038}
3039
3040static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set,
3041 struct request_queue *q)
3042{
3043 mutex_lock(&set->tag_list_lock);
3044
3045
3046
3047
3048 if (!list_empty(&set->tag_list) &&
3049 !(set->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) {
3050 set->flags |= BLK_MQ_F_TAG_QUEUE_SHARED;
3051
3052 blk_mq_update_tag_set_shared(set, true);
3053 }
3054 if (set->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
3055 queue_set_hctx_shared(q, true);
3056 list_add_tail(&q->tag_set_list, &set->tag_list);
3057
3058 mutex_unlock(&set->tag_list_lock);
3059}
3060
3061
3062static int blk_mq_alloc_ctxs(struct request_queue *q)
3063{
3064 struct blk_mq_ctxs *ctxs;
3065 int cpu;
3066
3067 ctxs = kzalloc(sizeof(*ctxs), GFP_KERNEL);
3068 if (!ctxs)
3069 return -ENOMEM;
3070
3071 ctxs->queue_ctx = alloc_percpu(struct blk_mq_ctx);
3072 if (!ctxs->queue_ctx)
3073 goto fail;
3074
3075 for_each_possible_cpu(cpu) {
3076 struct blk_mq_ctx *ctx = per_cpu_ptr(ctxs->queue_ctx, cpu);
3077 ctx->ctxs = ctxs;
3078 }
3079
3080 q->mq_kobj = &ctxs->kobj;
3081 q->queue_ctx = ctxs->queue_ctx;
3082
3083 return 0;
3084 fail:
3085 kfree(ctxs);
3086 return -ENOMEM;
3087}
3088
3089
3090
3091
3092
3093
3094
3095void blk_mq_release(struct request_queue *q)
3096{
3097 struct blk_mq_hw_ctx *hctx, *next;
3098 int i;
3099
3100 queue_for_each_hw_ctx(q, hctx, i)
3101 WARN_ON_ONCE(hctx && list_empty(&hctx->hctx_list));
3102
3103
3104 list_for_each_entry_safe(hctx, next, &q->unused_hctx_list, hctx_list) {
3105 list_del_init(&hctx->hctx_list);
3106 kobject_put(&hctx->kobj);
3107 }
3108
3109 kfree(q->queue_hw_ctx);
3110
3111
3112
3113
3114
3115 blk_mq_sysfs_deinit(q);
3116}
3117
3118static struct request_queue *blk_mq_init_queue_data(struct blk_mq_tag_set *set,
3119 void *queuedata)
3120{
3121 struct request_queue *q;
3122 int ret;
3123
3124 q = blk_alloc_queue(set->numa_node);
3125 if (!q)
3126 return ERR_PTR(-ENOMEM);
3127 q->queuedata = queuedata;
3128 ret = blk_mq_init_allocated_queue(set, q);
3129 if (ret) {
3130 blk_cleanup_queue(q);
3131 return ERR_PTR(ret);
3132 }
3133 return q;
3134}
3135
3136struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
3137{
3138 return blk_mq_init_queue_data(set, NULL);
3139}
3140EXPORT_SYMBOL(blk_mq_init_queue);
3141
3142struct gendisk *__blk_mq_alloc_disk(struct blk_mq_tag_set *set, void *queuedata,
3143 struct lock_class_key *lkclass)
3144{
3145 struct request_queue *q;
3146 struct gendisk *disk;
3147
3148 q = blk_mq_init_queue_data(set, queuedata);
3149 if (IS_ERR(q))
3150 return ERR_CAST(q);
3151
3152 disk = __alloc_disk_node(q, set->numa_node, lkclass);
3153 if (!disk) {
3154 blk_cleanup_queue(q);
3155 return ERR_PTR(-ENOMEM);
3156 }
3157 return disk;
3158}
3159EXPORT_SYMBOL(__blk_mq_alloc_disk);
3160
3161static struct blk_mq_hw_ctx *blk_mq_alloc_and_init_hctx(
3162 struct blk_mq_tag_set *set, struct request_queue *q,
3163 int hctx_idx, int node)
3164{
3165 struct blk_mq_hw_ctx *hctx = NULL, *tmp;
3166
3167
3168 spin_lock(&q->unused_hctx_lock);
3169 list_for_each_entry(tmp, &q->unused_hctx_list, hctx_list) {
3170 if (tmp->numa_node == node) {
3171 hctx = tmp;
3172 break;
3173 }
3174 }
3175 if (hctx)
3176 list_del_init(&hctx->hctx_list);
3177 spin_unlock(&q->unused_hctx_lock);
3178
3179 if (!hctx)
3180 hctx = blk_mq_alloc_hctx(q, set, node);
3181 if (!hctx)
3182 goto fail;
3183
3184 if (blk_mq_init_hctx(q, set, hctx, hctx_idx))
3185 goto free_hctx;
3186
3187 return hctx;
3188
3189 free_hctx:
3190 kobject_put(&hctx->kobj);
3191 fail:
3192 return NULL;
3193}
3194
3195static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set,
3196 struct request_queue *q)
3197{
3198 int i, j, end;
3199 struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx;
3200
3201 if (q->nr_hw_queues < set->nr_hw_queues) {
3202 struct blk_mq_hw_ctx **new_hctxs;
3203
3204 new_hctxs = kcalloc_node(set->nr_hw_queues,
3205 sizeof(*new_hctxs), GFP_KERNEL,
3206 set->numa_node);
3207 if (!new_hctxs)
3208 return;
3209 if (hctxs)
3210 memcpy(new_hctxs, hctxs, q->nr_hw_queues *
3211 sizeof(*hctxs));
3212 q->queue_hw_ctx = new_hctxs;
3213 kfree(hctxs);
3214 hctxs = new_hctxs;
3215 }
3216
3217
3218 mutex_lock(&q->sysfs_lock);
3219 for (i = 0; i < set->nr_hw_queues; i++) {
3220 int node;
3221 struct blk_mq_hw_ctx *hctx;
3222
3223 node = blk_mq_hw_queue_to_node(&set->map[HCTX_TYPE_DEFAULT], i);
3224
3225
3226
3227
3228
3229 if (hctxs[i] && (hctxs[i]->numa_node == node))
3230 continue;
3231
3232 hctx = blk_mq_alloc_and_init_hctx(set, q, i, node);
3233 if (hctx) {
3234 if (hctxs[i])
3235 blk_mq_exit_hctx(q, set, hctxs[i], i);
3236 hctxs[i] = hctx;
3237 } else {
3238 if (hctxs[i])
3239 pr_warn("Allocate new hctx on node %d fails,\
3240 fallback to previous one on node %d\n",
3241 node, hctxs[i]->numa_node);
3242 else
3243 break;
3244 }
3245 }
3246
3247
3248
3249
3250 if (i != set->nr_hw_queues) {
3251 j = q->nr_hw_queues;
3252 end = i;
3253 } else {
3254 j = i;
3255 end = q->nr_hw_queues;
3256 q->nr_hw_queues = set->nr_hw_queues;
3257 }
3258
3259 for (; j < end; j++) {
3260 struct blk_mq_hw_ctx *hctx = hctxs[j];
3261
3262 if (hctx) {
3263 if (hctx->tags)
3264 blk_mq_free_map_and_requests(set, j);
3265 blk_mq_exit_hctx(q, set, hctx, j);
3266 hctxs[j] = NULL;
3267 }
3268 }
3269 mutex_unlock(&q->sysfs_lock);
3270}
3271
3272int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
3273 struct request_queue *q)
3274{
3275
3276 q->mq_ops = set->ops;
3277
3278 q->poll_cb = blk_stat_alloc_callback(blk_mq_poll_stats_fn,
3279 blk_mq_poll_stats_bkt,
3280 BLK_MQ_POLL_STATS_BKTS, q);
3281 if (!q->poll_cb)
3282 goto err_exit;
3283
3284 if (blk_mq_alloc_ctxs(q))
3285 goto err_poll;
3286
3287
3288 blk_mq_sysfs_init(q);
3289
3290 INIT_LIST_HEAD(&q->unused_hctx_list);
3291 spin_lock_init(&q->unused_hctx_lock);
3292
3293 blk_mq_realloc_hw_ctxs(set, q);
3294 if (!q->nr_hw_queues)
3295 goto err_hctxs;
3296
3297 INIT_WORK(&q->timeout_work, blk_mq_timeout_work);
3298 blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ);
3299
3300 q->tag_set = set;
3301
3302 q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;
3303 if (set->nr_maps > HCTX_TYPE_POLL &&
3304 set->map[HCTX_TYPE_POLL].nr_queues)
3305 blk_queue_flag_set(QUEUE_FLAG_POLL, q);
3306
3307 INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work);
3308 INIT_LIST_HEAD(&q->requeue_list);
3309 spin_lock_init(&q->requeue_lock);
3310
3311 q->nr_requests = set->queue_depth;
3312
3313
3314
3315
3316 q->poll_nsec = BLK_MQ_POLL_CLASSIC;
3317
3318 blk_mq_init_cpu_queues(q, set->nr_hw_queues);
3319 blk_mq_add_queue_tag_set(set, q);
3320 blk_mq_map_swqueue(q);
3321 return 0;
3322
3323err_hctxs:
3324 kfree(q->queue_hw_ctx);
3325 q->nr_hw_queues = 0;
3326 blk_mq_sysfs_deinit(q);
3327err_poll:
3328 blk_stat_free_callback(q->poll_cb);
3329 q->poll_cb = NULL;
3330err_exit:
3331 q->mq_ops = NULL;
3332 return -ENOMEM;
3333}
3334EXPORT_SYMBOL(blk_mq_init_allocated_queue);
3335
3336
3337void blk_mq_exit_queue(struct request_queue *q)
3338{
3339 struct blk_mq_tag_set *set = q->tag_set;
3340
3341
3342 blk_mq_exit_hw_queues(q, set, set->nr_hw_queues);
3343
3344 blk_mq_del_queue_tag_set(q);
3345}
3346
3347static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
3348{
3349 int i;
3350
3351 for (i = 0; i < set->nr_hw_queues; i++) {
3352 if (!__blk_mq_alloc_map_and_request(set, i))
3353 goto out_unwind;
3354 cond_resched();
3355 }
3356
3357 return 0;
3358
3359out_unwind:
3360 while (--i >= 0)
3361 blk_mq_free_map_and_requests(set, i);
3362
3363 return -ENOMEM;
3364}
3365
3366
3367
3368
3369
3370
3371static int blk_mq_alloc_map_and_requests(struct blk_mq_tag_set *set)
3372{
3373 unsigned int depth;
3374 int err;
3375
3376 depth = set->queue_depth;
3377 do {
3378 err = __blk_mq_alloc_rq_maps(set);
3379 if (!err)
3380 break;
3381
3382 set->queue_depth >>= 1;
3383 if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) {
3384 err = -ENOMEM;
3385 break;
3386 }
3387 } while (set->queue_depth);
3388
3389 if (!set->queue_depth || err) {
3390 pr_err("blk-mq: failed to allocate request map\n");
3391 return -ENOMEM;
3392 }
3393
3394 if (depth != set->queue_depth)
3395 pr_info("blk-mq: reduced tag depth (%u -> %u)\n",
3396 depth, set->queue_depth);
3397
3398 return 0;
3399}
3400
3401static int blk_mq_update_queue_map(struct blk_mq_tag_set *set)
3402{
3403
3404
3405
3406
3407
3408 if (set->nr_maps == 1)
3409 set->map[HCTX_TYPE_DEFAULT].nr_queues = set->nr_hw_queues;
3410
3411 if (set->ops->map_queues && !is_kdump_kernel()) {
3412 int i;
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428 for (i = 0; i < set->nr_maps; i++)
3429 blk_mq_clear_mq_map(&set->map[i]);
3430
3431 return set->ops->map_queues(set);
3432 } else {
3433 BUG_ON(set->nr_maps > 1);
3434 return blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]);
3435 }
3436}
3437
3438static int blk_mq_realloc_tag_set_tags(struct blk_mq_tag_set *set,
3439 int cur_nr_hw_queues, int new_nr_hw_queues)
3440{
3441 struct blk_mq_tags **new_tags;
3442
3443 if (cur_nr_hw_queues >= new_nr_hw_queues)
3444 return 0;
3445
3446 new_tags = kcalloc_node(new_nr_hw_queues, sizeof(struct blk_mq_tags *),
3447 GFP_KERNEL, set->numa_node);
3448 if (!new_tags)
3449 return -ENOMEM;
3450
3451 if (set->tags)
3452 memcpy(new_tags, set->tags, cur_nr_hw_queues *
3453 sizeof(*set->tags));
3454 kfree(set->tags);
3455 set->tags = new_tags;
3456 set->nr_hw_queues = new_nr_hw_queues;
3457
3458 return 0;
3459}
3460
3461static int blk_mq_alloc_tag_set_tags(struct blk_mq_tag_set *set,
3462 int new_nr_hw_queues)
3463{
3464 return blk_mq_realloc_tag_set_tags(set, 0, new_nr_hw_queues);
3465}
3466
3467
3468
3469
3470
3471
3472
3473int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
3474{
3475 int i, ret;
3476
3477 BUILD_BUG_ON(BLK_MQ_MAX_DEPTH > 1 << BLK_MQ_UNIQUE_TAG_BITS);
3478
3479 if (!set->nr_hw_queues)
3480 return -EINVAL;
3481 if (!set->queue_depth)
3482 return -EINVAL;
3483 if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN)
3484 return -EINVAL;
3485
3486 if (!set->ops->queue_rq)
3487 return -EINVAL;
3488
3489 if (!set->ops->get_budget ^ !set->ops->put_budget)
3490 return -EINVAL;
3491
3492 if (set->queue_depth > BLK_MQ_MAX_DEPTH) {
3493 pr_info("blk-mq: reduced tag depth to %u\n",
3494 BLK_MQ_MAX_DEPTH);
3495 set->queue_depth = BLK_MQ_MAX_DEPTH;
3496 }
3497
3498 if (!set->nr_maps)
3499 set->nr_maps = 1;
3500 else if (set->nr_maps > HCTX_MAX_TYPES)
3501 return -EINVAL;
3502
3503
3504
3505
3506
3507
3508 if (is_kdump_kernel()) {
3509 set->nr_hw_queues = 1;
3510 set->nr_maps = 1;
3511 set->queue_depth = min(64U, set->queue_depth);
3512 }
3513
3514
3515
3516
3517 if (set->nr_maps == 1 && set->nr_hw_queues > nr_cpu_ids)
3518 set->nr_hw_queues = nr_cpu_ids;
3519
3520 if (blk_mq_alloc_tag_set_tags(set, set->nr_hw_queues) < 0)
3521 return -ENOMEM;
3522
3523 ret = -ENOMEM;
3524 for (i = 0; i < set->nr_maps; i++) {
3525 set->map[i].mq_map = kcalloc_node(nr_cpu_ids,
3526 sizeof(set->map[i].mq_map[0]),
3527 GFP_KERNEL, set->numa_node);
3528 if (!set->map[i].mq_map)
3529 goto out_free_mq_map;
3530 set->map[i].nr_queues = is_kdump_kernel() ? 1 : set->nr_hw_queues;
3531 }
3532
3533 ret = blk_mq_update_queue_map(set);
3534 if (ret)
3535 goto out_free_mq_map;
3536
3537 ret = blk_mq_alloc_map_and_requests(set);
3538 if (ret)
3539 goto out_free_mq_map;
3540
3541 if (blk_mq_is_sbitmap_shared(set->flags)) {
3542 atomic_set(&set->active_queues_shared_sbitmap, 0);
3543
3544 if (blk_mq_init_shared_sbitmap(set)) {
3545 ret = -ENOMEM;
3546 goto out_free_mq_rq_maps;
3547 }
3548 }
3549
3550 mutex_init(&set->tag_list_lock);
3551 INIT_LIST_HEAD(&set->tag_list);
3552
3553 return 0;
3554
3555out_free_mq_rq_maps:
3556 for (i = 0; i < set->nr_hw_queues; i++)
3557 blk_mq_free_map_and_requests(set, i);
3558out_free_mq_map:
3559 for (i = 0; i < set->nr_maps; i++) {
3560 kfree(set->map[i].mq_map);
3561 set->map[i].mq_map = NULL;
3562 }
3563 kfree(set->tags);
3564 set->tags = NULL;
3565 return ret;
3566}
3567EXPORT_SYMBOL(blk_mq_alloc_tag_set);
3568
3569
3570int blk_mq_alloc_sq_tag_set(struct blk_mq_tag_set *set,
3571 const struct blk_mq_ops *ops, unsigned int queue_depth,
3572 unsigned int set_flags)
3573{
3574 memset(set, 0, sizeof(*set));
3575 set->ops = ops;
3576 set->nr_hw_queues = 1;
3577 set->nr_maps = 1;
3578 set->queue_depth = queue_depth;
3579 set->numa_node = NUMA_NO_NODE;
3580 set->flags = set_flags;
3581 return blk_mq_alloc_tag_set(set);
3582}
3583EXPORT_SYMBOL_GPL(blk_mq_alloc_sq_tag_set);
3584
3585void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
3586{
3587 int i, j;
3588
3589 for (i = 0; i < set->nr_hw_queues; i++)
3590 blk_mq_free_map_and_requests(set, i);
3591
3592 if (blk_mq_is_sbitmap_shared(set->flags))
3593 blk_mq_exit_shared_sbitmap(set);
3594
3595 for (j = 0; j < set->nr_maps; j++) {
3596 kfree(set->map[j].mq_map);
3597 set->map[j].mq_map = NULL;
3598 }
3599
3600 kfree(set->tags);
3601 set->tags = NULL;
3602}
3603EXPORT_SYMBOL(blk_mq_free_tag_set);
3604
3605int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
3606{
3607 struct blk_mq_tag_set *set = q->tag_set;
3608 struct blk_mq_hw_ctx *hctx;
3609 int i, ret;
3610
3611 if (!set)
3612 return -EINVAL;
3613
3614 if (q->nr_requests == nr)
3615 return 0;
3616
3617 blk_mq_freeze_queue(q);
3618 blk_mq_quiesce_queue(q);
3619
3620 ret = 0;
3621 queue_for_each_hw_ctx(q, hctx, i) {
3622 if (!hctx->tags)
3623 continue;
3624
3625
3626
3627
3628 if (!hctx->sched_tags) {
3629 ret = blk_mq_tag_update_depth(hctx, &hctx->tags, nr,
3630 false);
3631 if (!ret && blk_mq_is_sbitmap_shared(set->flags))
3632 blk_mq_tag_resize_shared_sbitmap(set, nr);
3633 } else {
3634 ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags,
3635 nr, true);
3636 if (blk_mq_is_sbitmap_shared(set->flags)) {
3637 hctx->sched_tags->bitmap_tags =
3638 &q->sched_bitmap_tags;
3639 hctx->sched_tags->breserved_tags =
3640 &q->sched_breserved_tags;
3641 }
3642 }
3643 if (ret)
3644 break;
3645 if (q->elevator && q->elevator->type->ops.depth_updated)
3646 q->elevator->type->ops.depth_updated(hctx);
3647 }
3648 if (!ret) {
3649 q->nr_requests = nr;
3650 if (q->elevator && blk_mq_is_sbitmap_shared(set->flags))
3651 sbitmap_queue_resize(&q->sched_bitmap_tags,
3652 nr - set->reserved_tags);
3653 }
3654
3655 blk_mq_unquiesce_queue(q);
3656 blk_mq_unfreeze_queue(q);
3657
3658 return ret;
3659}
3660
3661
3662
3663
3664
3665
3666struct blk_mq_qe_pair {
3667 struct list_head node;
3668 struct request_queue *q;
3669 struct elevator_type *type;
3670};
3671
3672
3673
3674
3675
3676static bool blk_mq_elv_switch_none(struct list_head *head,
3677 struct request_queue *q)
3678{
3679 struct blk_mq_qe_pair *qe;
3680
3681 if (!q->elevator)
3682 return true;
3683
3684 qe = kmalloc(sizeof(*qe), GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY);
3685 if (!qe)
3686 return false;
3687
3688 INIT_LIST_HEAD(&qe->node);
3689 qe->q = q;
3690 qe->type = q->elevator->type;
3691 list_add(&qe->node, head);
3692
3693 mutex_lock(&q->sysfs_lock);
3694
3695
3696
3697
3698
3699
3700
3701 __module_get(qe->type->elevator_owner);
3702 elevator_switch_mq(q, NULL);
3703 mutex_unlock(&q->sysfs_lock);
3704
3705 return true;
3706}
3707
3708static void blk_mq_elv_switch_back(struct list_head *head,
3709 struct request_queue *q)
3710{
3711 struct blk_mq_qe_pair *qe;
3712 struct elevator_type *t = NULL;
3713
3714 list_for_each_entry(qe, head, node)
3715 if (qe->q == q) {
3716 t = qe->type;
3717 break;
3718 }
3719
3720 if (!t)
3721 return;
3722
3723 list_del(&qe->node);
3724 kfree(qe);
3725
3726 mutex_lock(&q->sysfs_lock);
3727 elevator_switch_mq(q, t);
3728 mutex_unlock(&q->sysfs_lock);
3729}
3730
3731static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set,
3732 int nr_hw_queues)
3733{
3734 struct request_queue *q;
3735 LIST_HEAD(head);
3736 int prev_nr_hw_queues;
3737
3738 lockdep_assert_held(&set->tag_list_lock);
3739
3740 if (set->nr_maps == 1 && nr_hw_queues > nr_cpu_ids)
3741 nr_hw_queues = nr_cpu_ids;
3742 if (nr_hw_queues < 1)
3743 return;
3744 if (set->nr_maps == 1 && nr_hw_queues == set->nr_hw_queues)
3745 return;
3746
3747 list_for_each_entry(q, &set->tag_list, tag_set_list)
3748 blk_mq_freeze_queue(q);
3749
3750
3751
3752
3753
3754 list_for_each_entry(q, &set->tag_list, tag_set_list)
3755 if (!blk_mq_elv_switch_none(&head, q))
3756 goto switch_back;
3757
3758 list_for_each_entry(q, &set->tag_list, tag_set_list) {
3759 blk_mq_debugfs_unregister_hctxs(q);
3760 blk_mq_sysfs_unregister(q);
3761 }
3762
3763 prev_nr_hw_queues = set->nr_hw_queues;
3764 if (blk_mq_realloc_tag_set_tags(set, set->nr_hw_queues, nr_hw_queues) <
3765 0)
3766 goto reregister;
3767
3768 set->nr_hw_queues = nr_hw_queues;
3769fallback:
3770 blk_mq_update_queue_map(set);
3771 list_for_each_entry(q, &set->tag_list, tag_set_list) {
3772 blk_mq_realloc_hw_ctxs(set, q);
3773 if (q->nr_hw_queues != set->nr_hw_queues) {
3774 pr_warn("Increasing nr_hw_queues to %d fails, fallback to %d\n",
3775 nr_hw_queues, prev_nr_hw_queues);
3776 set->nr_hw_queues = prev_nr_hw_queues;
3777 blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]);
3778 goto fallback;
3779 }
3780 blk_mq_map_swqueue(q);
3781 }
3782
3783reregister:
3784 list_for_each_entry(q, &set->tag_list, tag_set_list) {
3785 blk_mq_sysfs_register(q);
3786 blk_mq_debugfs_register_hctxs(q);
3787 }
3788
3789switch_back:
3790 list_for_each_entry(q, &set->tag_list, tag_set_list)
3791 blk_mq_elv_switch_back(&head, q);
3792
3793 list_for_each_entry(q, &set->tag_list, tag_set_list)
3794 blk_mq_unfreeze_queue(q);
3795}
3796
3797void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues)
3798{
3799 mutex_lock(&set->tag_list_lock);
3800 __blk_mq_update_nr_hw_queues(set, nr_hw_queues);
3801 mutex_unlock(&set->tag_list_lock);
3802}
3803EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues);
3804
3805
3806static bool blk_poll_stats_enable(struct request_queue *q)
3807{
3808 if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags) ||
3809 blk_queue_flag_test_and_set(QUEUE_FLAG_POLL_STATS, q))
3810 return true;
3811 blk_stat_add_callback(q, q->poll_cb);
3812 return false;
3813}
3814
3815static void blk_mq_poll_stats_start(struct request_queue *q)
3816{
3817
3818
3819
3820
3821 if (!test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags) ||
3822 blk_stat_is_active(q->poll_cb))
3823 return;
3824
3825 blk_stat_activate_msecs(q->poll_cb, 100);
3826}
3827
3828static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb)
3829{
3830 struct request_queue *q = cb->data;
3831 int bucket;
3832
3833 for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS; bucket++) {
3834 if (cb->stat[bucket].nr_samples)
3835 q->poll_stat[bucket] = cb->stat[bucket];
3836 }
3837}
3838
3839static unsigned long blk_mq_poll_nsecs(struct request_queue *q,
3840 struct request *rq)
3841{
3842 unsigned long ret = 0;
3843 int bucket;
3844
3845
3846
3847
3848
3849 if (!blk_poll_stats_enable(q))
3850 return 0;
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861 bucket = blk_mq_poll_stats_bkt(rq);
3862 if (bucket < 0)
3863 return ret;
3864
3865 if (q->poll_stat[bucket].nr_samples)
3866 ret = (q->poll_stat[bucket].mean + 1) / 2;
3867
3868 return ret;
3869}
3870
3871static bool blk_mq_poll_hybrid_sleep(struct request_queue *q,
3872 struct request *rq)
3873{
3874 struct hrtimer_sleeper hs;
3875 enum hrtimer_mode mode;
3876 unsigned int nsecs;
3877 ktime_t kt;
3878
3879 if (rq->rq_flags & RQF_MQ_POLL_SLEPT)
3880 return false;
3881
3882
3883
3884
3885
3886
3887
3888 if (q->poll_nsec > 0)
3889 nsecs = q->poll_nsec;
3890 else
3891 nsecs = blk_mq_poll_nsecs(q, rq);
3892
3893 if (!nsecs)
3894 return false;
3895
3896 rq->rq_flags |= RQF_MQ_POLL_SLEPT;
3897
3898
3899
3900
3901
3902 kt = nsecs;
3903
3904 mode = HRTIMER_MODE_REL;
3905 hrtimer_init_sleeper_on_stack(&hs, CLOCK_MONOTONIC, mode);
3906 hrtimer_set_expires(&hs.timer, kt);
3907
3908 do {
3909 if (blk_mq_rq_state(rq) == MQ_RQ_COMPLETE)
3910 break;
3911 set_current_state(TASK_UNINTERRUPTIBLE);
3912 hrtimer_sleeper_start_expires(&hs, mode);
3913 if (hs.task)
3914 io_schedule();
3915 hrtimer_cancel(&hs.timer);
3916 mode = HRTIMER_MODE_ABS;
3917 } while (hs.task && !signal_pending(current));
3918
3919 __set_current_state(TASK_RUNNING);
3920 destroy_hrtimer_on_stack(&hs.timer);
3921 return true;
3922}
3923
3924static bool blk_mq_poll_hybrid(struct request_queue *q,
3925 struct blk_mq_hw_ctx *hctx, blk_qc_t cookie)
3926{
3927 struct request *rq;
3928
3929 if (q->poll_nsec == BLK_MQ_POLL_CLASSIC)
3930 return false;
3931
3932 if (!blk_qc_t_is_internal(cookie))
3933 rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie));
3934 else {
3935 rq = blk_mq_tag_to_rq(hctx->sched_tags, blk_qc_t_to_tag(cookie));
3936
3937
3938
3939
3940
3941
3942 if (!rq)
3943 return false;
3944 }
3945
3946 return blk_mq_poll_hybrid_sleep(q, rq);
3947}
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin)
3962{
3963 struct blk_mq_hw_ctx *hctx;
3964 unsigned int state;
3965
3966 if (!blk_qc_t_valid(cookie) ||
3967 !test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
3968 return 0;
3969
3970 if (current->plug)
3971 blk_flush_plug_list(current->plug, false);
3972
3973 hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)];
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983 if (spin && blk_mq_poll_hybrid(q, hctx, cookie))
3984 return 1;
3985
3986 hctx->poll_considered++;
3987
3988 state = get_current_state();
3989 do {
3990 int ret;
3991
3992 hctx->poll_invoked++;
3993
3994 ret = q->mq_ops->poll(hctx);
3995 if (ret > 0) {
3996 hctx->poll_success++;
3997 __set_current_state(TASK_RUNNING);
3998 return ret;
3999 }
4000
4001 if (signal_pending_state(state, current))
4002 __set_current_state(TASK_RUNNING);
4003
4004 if (task_is_running(current))
4005 return 1;
4006 if (ret < 0 || !spin)
4007 break;
4008 cpu_relax();
4009 } while (!need_resched());
4010
4011 __set_current_state(TASK_RUNNING);
4012 return 0;
4013}
4014EXPORT_SYMBOL_GPL(blk_poll);
4015
4016unsigned int blk_mq_rq_cpu(struct request *rq)
4017{
4018 return rq->mq_ctx->cpu;
4019}
4020EXPORT_SYMBOL(blk_mq_rq_cpu);
4021
4022static int __init blk_mq_init(void)
4023{
4024 int i;
4025
4026 for_each_possible_cpu(i)
4027 init_llist_head(&per_cpu(blk_cpu_done, i));
4028 open_softirq(BLOCK_SOFTIRQ, blk_done_softirq);
4029
4030 cpuhp_setup_state_nocalls(CPUHP_BLOCK_SOFTIRQ_DEAD,
4031 "block/softirq:dead", NULL,
4032 blk_softirq_cpu_dead);
4033 cpuhp_setup_state_multi(CPUHP_BLK_MQ_DEAD, "block/mq:dead", NULL,
4034 blk_mq_hctx_notify_dead);
4035 cpuhp_setup_state_multi(CPUHP_AP_BLK_MQ_ONLINE, "block/mq:online",
4036 blk_mq_hctx_notify_online,
4037 blk_mq_hctx_notify_offline);
4038 return 0;
4039}
4040subsys_initcall(blk_mq_init);
4041