blk-mq: fix two misuses on RQF_USE_SCHED
[linux-block.git] / block / blk-mq.c
CommitLineData
3dcf60bc 1// SPDX-License-Identifier: GPL-2.0
75bb4625
JA
2/*
3 * Block multiqueue core code
4 *
5 * Copyright (C) 2013-2014 Jens Axboe
6 * Copyright (C) 2013-2014 Christoph Hellwig
7 */
320ae51f
JA
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>
fe45e630 13#include <linux/blk-integrity.h>
f75782e4 14#include <linux/kmemleak.h>
320ae51f
JA
15#include <linux/mm.h>
16#include <linux/init.h>
17#include <linux/slab.h>
18#include <linux/workqueue.h>
19#include <linux/smp.h>
e41d12f5 20#include <linux/interrupt.h>
320ae51f 21#include <linux/llist.h>
320ae51f
JA
22#include <linux/cpu.h>
23#include <linux/cache.h>
24#include <linux/sched/sysctl.h>
105ab3d8 25#include <linux/sched/topology.h>
174cd4b1 26#include <linux/sched/signal.h>
320ae51f 27#include <linux/delay.h>
aedcd72f 28#include <linux/crash_dump.h>
88c7b2b7 29#include <linux/prefetch.h>
a892c8d5 30#include <linux/blk-crypto.h>
82d981d4 31#include <linux/part_stat.h>
320ae51f
JA
32
33#include <trace/events/block.h>
34
54d4e6ab 35#include <linux/t10-pi.h>
320ae51f
JA
36#include "blk.h"
37#include "blk-mq.h"
9c1051aa 38#include "blk-mq-debugfs.h"
986d413b 39#include "blk-pm.h"
cf43e6be 40#include "blk-stat.h"
bd166ef1 41#include "blk-mq-sched.h"
c1c80384 42#include "blk-rq-qos.h"
82b74cac 43#include "blk-ioprio.h"
320ae51f 44
f9ab4918 45static DEFINE_PER_CPU(struct llist_head, blk_cpu_done);
c3077b5d 46
710fa378 47static void blk_mq_insert_request(struct request *rq, blk_insert_t flags);
360f2648
CH
48static void blk_mq_request_bypass_insert(struct request *rq,
49 blk_insert_t flags);
94aa228c
CH
50static void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
51 struct list_head *list);
3e08773c 52
f70299f0
CH
53static inline struct blk_mq_hw_ctx *blk_qc_to_hctx(struct request_queue *q,
54 blk_qc_t qc)
55{
54bdd67d 56 return xa_load(&q->hctx_table, qc);
c6699d6f
CH
57}
58
3e08773c
CH
59static inline blk_qc_t blk_rq_to_qc(struct request *rq)
60{
54bdd67d 61 return rq->mq_hctx->queue_num;
3e08773c
CH
62}
63
320ae51f 64/*
85fae294
YY
65 * Check if any of the ctx, dispatch list or elevator
66 * have pending work in this hardware queue.
320ae51f 67 */
79f720a7 68static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx)
320ae51f 69{
79f720a7
JA
70 return !list_empty_careful(&hctx->dispatch) ||
71 sbitmap_any_bit_set(&hctx->ctx_map) ||
bd166ef1 72 blk_mq_sched_has_work(hctx);
1429d7c9
JA
73}
74
320ae51f
JA
75/*
76 * Mark this ctx as having pending work in this hardware queue
77 */
78static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx,
79 struct blk_mq_ctx *ctx)
80{
f31967f0
JA
81 const int bit = ctx->index_hw[hctx->type];
82
83 if (!sbitmap_test_bit(&hctx->ctx_map, bit))
84 sbitmap_set_bit(&hctx->ctx_map, bit);
1429d7c9
JA
85}
86
87static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx,
88 struct blk_mq_ctx *ctx)
89{
f31967f0
JA
90 const int bit = ctx->index_hw[hctx->type];
91
92 sbitmap_clear_bit(&hctx->ctx_map, bit);
320ae51f
JA
93}
94
f299b7c7 95struct mq_inflight {
8446fe92 96 struct block_device *part;
a2e80f6f 97 unsigned int inflight[2];
f299b7c7
JA
98};
99
2dd6532e 100static bool blk_mq_check_inflight(struct request *rq, void *priv)
f299b7c7
JA
101{
102 struct mq_inflight *mi = priv;
103
b81c14ca
HW
104 if (rq->part && blk_do_io_stat(rq) &&
105 (!mi->part->bd_partno || rq->part == mi->part) &&
b0d97557 106 blk_mq_rq_state(rq) == MQ_RQ_IN_FLIGHT)
bb4e6b14 107 mi->inflight[rq_data_dir(rq)]++;
7baa8572
JA
108
109 return true;
f299b7c7
JA
110}
111
8446fe92
CH
112unsigned int blk_mq_in_flight(struct request_queue *q,
113 struct block_device *part)
f299b7c7 114{
a2e80f6f 115 struct mq_inflight mi = { .part = part };
f299b7c7 116
f299b7c7 117 blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi);
e016b782 118
a2e80f6f 119 return mi.inflight[0] + mi.inflight[1];
bf0ddaba
OS
120}
121
8446fe92
CH
122void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part,
123 unsigned int inflight[2])
bf0ddaba 124{
a2e80f6f 125 struct mq_inflight mi = { .part = part };
bf0ddaba 126
bb4e6b14 127 blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi);
a2e80f6f
PB
128 inflight[0] = mi.inflight[0];
129 inflight[1] = mi.inflight[1];
bf0ddaba
OS
130}
131
1671d522 132void blk_freeze_queue_start(struct request_queue *q)
43a5e4e2 133{
7996a8b5
BL
134 mutex_lock(&q->mq_freeze_lock);
135 if (++q->mq_freeze_depth == 1) {
3ef28e83 136 percpu_ref_kill(&q->q_usage_counter);
7996a8b5 137 mutex_unlock(&q->mq_freeze_lock);
344e9ffc 138 if (queue_is_mq(q))
055f6e18 139 blk_mq_run_hw_queues(q, false);
7996a8b5
BL
140 } else {
141 mutex_unlock(&q->mq_freeze_lock);
cddd5d17 142 }
f3af020b 143}
1671d522 144EXPORT_SYMBOL_GPL(blk_freeze_queue_start);
f3af020b 145
6bae363e 146void blk_mq_freeze_queue_wait(struct request_queue *q)
f3af020b 147{
3ef28e83 148 wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter));
43a5e4e2 149}
6bae363e 150EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait);
43a5e4e2 151
f91328c4
KB
152int blk_mq_freeze_queue_wait_timeout(struct request_queue *q,
153 unsigned long timeout)
154{
155 return wait_event_timeout(q->mq_freeze_wq,
156 percpu_ref_is_zero(&q->q_usage_counter),
157 timeout);
158}
159EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait_timeout);
43a5e4e2 160
f3af020b
TH
161/*
162 * Guarantee no request is in use, so we can change any data structure of
163 * the queue afterward.
164 */
3ef28e83 165void blk_freeze_queue(struct request_queue *q)
f3af020b 166{
3ef28e83
DW
167 /*
168 * In the !blk_mq case we are only calling this to kill the
169 * q_usage_counter, otherwise this increases the freeze depth
170 * and waits for it to return to zero. For this reason there is
171 * no blk_unfreeze_queue(), and blk_freeze_queue() is not
172 * exported to drivers as the only user for unfreeze is blk_mq.
173 */
1671d522 174 blk_freeze_queue_start(q);
f3af020b
TH
175 blk_mq_freeze_queue_wait(q);
176}
3ef28e83
DW
177
178void blk_mq_freeze_queue(struct request_queue *q)
179{
180 /*
181 * ...just an alias to keep freeze and unfreeze actions balanced
182 * in the blk_mq_* namespace
183 */
184 blk_freeze_queue(q);
185}
c761d96b 186EXPORT_SYMBOL_GPL(blk_mq_freeze_queue);
f3af020b 187
aec89dc5 188void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic)
320ae51f 189{
7996a8b5 190 mutex_lock(&q->mq_freeze_lock);
aec89dc5
CH
191 if (force_atomic)
192 q->q_usage_counter.data->force_atomic = true;
7996a8b5
BL
193 q->mq_freeze_depth--;
194 WARN_ON_ONCE(q->mq_freeze_depth < 0);
195 if (!q->mq_freeze_depth) {
bdd63160 196 percpu_ref_resurrect(&q->q_usage_counter);
320ae51f 197 wake_up_all(&q->mq_freeze_wq);
add703fd 198 }
7996a8b5 199 mutex_unlock(&q->mq_freeze_lock);
320ae51f 200}
aec89dc5
CH
201
202void blk_mq_unfreeze_queue(struct request_queue *q)
203{
204 __blk_mq_unfreeze_queue(q, false);
205}
b4c6a028 206EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);
320ae51f 207
852ec809
BVA
208/*
209 * FIXME: replace the scsi_internal_device_*block_nowait() calls in the
210 * mpt3sas driver such that this function can be removed.
211 */
212void blk_mq_quiesce_queue_nowait(struct request_queue *q)
213{
e70feb8b
ML
214 unsigned long flags;
215
216 spin_lock_irqsave(&q->queue_lock, flags);
217 if (!q->quiesce_depth++)
218 blk_queue_flag_set(QUEUE_FLAG_QUIESCED, q);
219 spin_unlock_irqrestore(&q->queue_lock, flags);
852ec809
BVA
220}
221EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue_nowait);
222
6a83e74d 223/**
9ef4d020 224 * blk_mq_wait_quiesce_done() - wait until in-progress quiesce is done
483239c7 225 * @set: tag_set to wait on
6a83e74d 226 *
9ef4d020 227 * Note: it is driver's responsibility for making sure that quiesce has
483239c7
CH
228 * been started on or more of the request_queues of the tag_set. This
229 * function only waits for the quiesce on those request_queues that had
230 * the quiesce flag set using blk_mq_quiesce_queue_nowait.
6a83e74d 231 */
483239c7 232void blk_mq_wait_quiesce_done(struct blk_mq_tag_set *set)
6a83e74d 233{
483239c7
CH
234 if (set->flags & BLK_MQ_F_BLOCKING)
235 synchronize_srcu(set->srcu);
704b914f 236 else
6a83e74d
BVA
237 synchronize_rcu();
238}
9ef4d020
ML
239EXPORT_SYMBOL_GPL(blk_mq_wait_quiesce_done);
240
241/**
242 * blk_mq_quiesce_queue() - wait until all ongoing dispatches have finished
243 * @q: request queue.
244 *
245 * Note: this function does not prevent that the struct request end_io()
246 * callback function is invoked. Once this function is returned, we make
247 * sure no dispatch can happen until the queue is unquiesced via
248 * blk_mq_unquiesce_queue().
249 */
250void blk_mq_quiesce_queue(struct request_queue *q)
251{
252 blk_mq_quiesce_queue_nowait(q);
8537380b
CH
253 /* nothing to wait for non-mq queues */
254 if (queue_is_mq(q))
483239c7 255 blk_mq_wait_quiesce_done(q->tag_set);
9ef4d020 256}
6a83e74d
BVA
257EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue);
258
e4e73913
ML
259/*
260 * blk_mq_unquiesce_queue() - counterpart of blk_mq_quiesce_queue()
261 * @q: request queue.
262 *
263 * This function recovers queue into the state before quiescing
264 * which is done by blk_mq_quiesce_queue.
265 */
266void blk_mq_unquiesce_queue(struct request_queue *q)
267{
e70feb8b
ML
268 unsigned long flags;
269 bool run_queue = false;
270
271 spin_lock_irqsave(&q->queue_lock, flags);
272 if (WARN_ON_ONCE(q->quiesce_depth <= 0)) {
273 ;
274 } else if (!--q->quiesce_depth) {
275 blk_queue_flag_clear(QUEUE_FLAG_QUIESCED, q);
276 run_queue = true;
277 }
278 spin_unlock_irqrestore(&q->queue_lock, flags);
f4560ffe 279
1d9e9bc6 280 /* dispatch requests which are inserted during quiescing */
e70feb8b
ML
281 if (run_queue)
282 blk_mq_run_hw_queues(q, true);
e4e73913
ML
283}
284EXPORT_SYMBOL_GPL(blk_mq_unquiesce_queue);
285
414dd48e
CL
286void blk_mq_quiesce_tagset(struct blk_mq_tag_set *set)
287{
288 struct request_queue *q;
289
290 mutex_lock(&set->tag_list_lock);
291 list_for_each_entry(q, &set->tag_list, tag_set_list) {
292 if (!blk_queue_skip_tagset_quiesce(q))
293 blk_mq_quiesce_queue_nowait(q);
294 }
295 blk_mq_wait_quiesce_done(set);
296 mutex_unlock(&set->tag_list_lock);
297}
298EXPORT_SYMBOL_GPL(blk_mq_quiesce_tagset);
299
300void blk_mq_unquiesce_tagset(struct blk_mq_tag_set *set)
301{
302 struct request_queue *q;
303
304 mutex_lock(&set->tag_list_lock);
305 list_for_each_entry(q, &set->tag_list, tag_set_list) {
306 if (!blk_queue_skip_tagset_quiesce(q))
307 blk_mq_unquiesce_queue(q);
308 }
309 mutex_unlock(&set->tag_list_lock);
310}
311EXPORT_SYMBOL_GPL(blk_mq_unquiesce_tagset);
312
aed3ea94
JA
313void blk_mq_wake_waiters(struct request_queue *q)
314{
315 struct blk_mq_hw_ctx *hctx;
4f481208 316 unsigned long i;
aed3ea94
JA
317
318 queue_for_each_hw_ctx(q, hctx, i)
319 if (blk_mq_hw_queue_mapped(hctx))
320 blk_mq_tag_wakeup_all(hctx->tags, true);
321}
322
52fdbbcc
CH
323void blk_rq_init(struct request_queue *q, struct request *rq)
324{
325 memset(rq, 0, sizeof(*rq));
326
327 INIT_LIST_HEAD(&rq->queuelist);
328 rq->q = q;
329 rq->__sector = (sector_t) -1;
330 INIT_HLIST_NODE(&rq->hash);
331 RB_CLEAR_NODE(&rq->rb_node);
332 rq->tag = BLK_MQ_NO_TAG;
333 rq->internal_tag = BLK_MQ_NO_TAG;
334 rq->start_time_ns = ktime_get_ns();
335 rq->part = NULL;
336 blk_crypto_rq_set_defaults(rq);
337}
338EXPORT_SYMBOL(blk_rq_init);
339
e4cdf1a1 340static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
fe6134f6 341 struct blk_mq_tags *tags, unsigned int tag, u64 alloc_time_ns)
320ae51f 342{
605f784e
PB
343 struct blk_mq_ctx *ctx = data->ctx;
344 struct blk_mq_hw_ctx *hctx = data->hctx;
345 struct request_queue *q = data->q;
e4cdf1a1 346 struct request *rq = tags->static_rqs[tag];
c3a148d2 347
c7b84d42
JA
348 rq->q = q;
349 rq->mq_ctx = ctx;
350 rq->mq_hctx = hctx;
351 rq->cmd_flags = data->cmd_flags;
352
353 if (data->flags & BLK_MQ_REQ_PM)
354 data->rq_flags |= RQF_PM;
355 if (blk_queue_io_stat(q))
356 data->rq_flags |= RQF_IO_STAT;
357 rq->rq_flags = data->rq_flags;
358
dd6216bb 359 if (data->rq_flags & RQF_SCHED_TAGS) {
56f8da64
JA
360 rq->tag = BLK_MQ_NO_TAG;
361 rq->internal_tag = tag;
dd6216bb
CH
362 } else {
363 rq->tag = tag;
364 rq->internal_tag = BLK_MQ_NO_TAG;
e4cdf1a1 365 }
c7b84d42 366 rq->timeout = 0;
e4cdf1a1 367
4f266f2b
PB
368 if (blk_mq_need_time_stamp(rq))
369 rq->start_time_ns = ktime_get_ns();
370 else
371 rq->start_time_ns = 0;
af76e555 372 rq->part = NULL;
6f816b4b
TH
373#ifdef CONFIG_BLK_RQ_ALLOC_TIME
374 rq->alloc_time_ns = alloc_time_ns;
375#endif
544ccc8d 376 rq->io_start_time_ns = 0;
3d244306 377 rq->stats_sectors = 0;
af76e555
CH
378 rq->nr_phys_segments = 0;
379#if defined(CONFIG_BLK_DEV_INTEGRITY)
380 rq->nr_integrity_segments = 0;
381#endif
af76e555
CH
382 rq->end_io = NULL;
383 rq->end_io_data = NULL;
af76e555 384
4f266f2b
PB
385 blk_crypto_rq_set_defaults(rq);
386 INIT_LIST_HEAD(&rq->queuelist);
387 /* tag was already set */
388 WRITE_ONCE(rq->deadline, 0);
0a467d0f 389 req_ref_set(rq, 1);
7ea4d8a4 390
dd6216bb 391 if (rq->rq_flags & RQF_USE_SCHED) {
7ea4d8a4
CH
392 struct elevator_queue *e = data->q->elevator;
393
4f266f2b
PB
394 INIT_HLIST_NODE(&rq->hash);
395 RB_CLEAR_NODE(&rq->rb_node);
396
dd6216bb 397 if (e->type->ops.prepare_request)
7ea4d8a4 398 e->type->ops.prepare_request(rq);
7ea4d8a4
CH
399 }
400
e4cdf1a1 401 return rq;
5dee8577
CH
402}
403
349302da
JA
404static inline struct request *
405__blk_mq_alloc_requests_batch(struct blk_mq_alloc_data *data,
406 u64 alloc_time_ns)
407{
408 unsigned int tag, tag_offset;
fe6134f6 409 struct blk_mq_tags *tags;
349302da 410 struct request *rq;
fe6134f6 411 unsigned long tag_mask;
349302da
JA
412 int i, nr = 0;
413
fe6134f6
JA
414 tag_mask = blk_mq_get_tags(data, data->nr_tags, &tag_offset);
415 if (unlikely(!tag_mask))
349302da
JA
416 return NULL;
417
fe6134f6
JA
418 tags = blk_mq_tags_from_data(data);
419 for (i = 0; tag_mask; i++) {
420 if (!(tag_mask & (1UL << i)))
349302da
JA
421 continue;
422 tag = tag_offset + i;
a22c00be 423 prefetch(tags->static_rqs[tag]);
fe6134f6
JA
424 tag_mask &= ~(1UL << i);
425 rq = blk_mq_rq_ctx_init(data, tags, tag, alloc_time_ns);
013a7f95 426 rq_list_add(data->cached_rq, rq);
c5fc7b93 427 nr++;
349302da 428 }
c5fc7b93
JA
429 /* caller already holds a reference, add for remainder */
430 percpu_ref_get_many(&data->q->q_usage_counter, nr - 1);
349302da
JA
431 data->nr_tags -= nr;
432
013a7f95 433 return rq_list_pop(data->cached_rq);
349302da
JA
434}
435
b90cfaed 436static struct request *__blk_mq_alloc_requests(struct blk_mq_alloc_data *data)
d2c0d383 437{
e6e7abff 438 struct request_queue *q = data->q;
6f816b4b 439 u64 alloc_time_ns = 0;
47c122e3 440 struct request *rq;
600c3b0c 441 unsigned int tag;
d2c0d383 442
6f816b4b
TH
443 /* alloc_time includes depth and tag waits */
444 if (blk_queue_rq_alloc_time(q))
445 alloc_time_ns = ktime_get_ns();
446
f9afca4d 447 if (data->cmd_flags & REQ_NOWAIT)
03a07c92 448 data->flags |= BLK_MQ_REQ_NOWAIT;
d2c0d383 449
781dd830 450 if (q->elevator) {
dd6216bb
CH
451 /*
452 * All requests use scheduler tags when an I/O scheduler is
453 * enabled for the queue.
454 */
455 data->rq_flags |= RQF_SCHED_TAGS;
781dd830 456
d2c0d383 457 /*
8d663f34 458 * Flush/passthrough requests are special and go directly to the
dd6216bb 459 * dispatch list.
d2c0d383 460 */
be4c4278 461 if ((data->cmd_flags & REQ_OP_MASK) != REQ_OP_FLUSH &&
dd6216bb
CH
462 !blk_op_is_passthrough(data->cmd_flags)) {
463 struct elevator_mq_ops *ops = &q->elevator->type->ops;
464
465 WARN_ON_ONCE(data->flags & BLK_MQ_REQ_RESERVED);
466
467 data->rq_flags |= RQF_USE_SCHED;
468 if (ops->limit_depth)
469 ops->limit_depth(data->cmd_flags, data);
470 }
d2c0d383
CH
471 }
472
bf0beec0 473retry:
600c3b0c
CH
474 data->ctx = blk_mq_get_ctx(q);
475 data->hctx = blk_mq_map_queue(q, data->cmd_flags, data->ctx);
dd6216bb 476 if (!(data->rq_flags & RQF_SCHED_TAGS))
600c3b0c
CH
477 blk_mq_tag_busy(data->hctx);
478
99e48cd6
JG
479 if (data->flags & BLK_MQ_REQ_RESERVED)
480 data->rq_flags |= RQF_RESV;
481
349302da
JA
482 /*
483 * Try batched alloc if we want more than 1 tag.
484 */
485 if (data->nr_tags > 1) {
486 rq = __blk_mq_alloc_requests_batch(data, alloc_time_ns);
487 if (rq)
488 return rq;
489 data->nr_tags = 1;
490 }
491
bf0beec0
ML
492 /*
493 * Waiting allocations only fail because of an inactive hctx. In that
494 * case just retry the hctx assignment and tag allocation as CPU hotplug
495 * should have migrated us to an online CPU by now.
496 */
e4cdf1a1 497 tag = blk_mq_get_tag(data);
bf0beec0
ML
498 if (tag == BLK_MQ_NO_TAG) {
499 if (data->flags & BLK_MQ_REQ_NOWAIT)
500 return NULL;
bf0beec0 501 /*
349302da
JA
502 * Give up the CPU and sleep for a random short time to
503 * ensure that thread using a realtime scheduling class
504 * are migrated off the CPU, and thus off the hctx that
505 * is going away.
bf0beec0
ML
506 */
507 msleep(3);
508 goto retry;
509 }
47c122e3 510
fe6134f6
JA
511 return blk_mq_rq_ctx_init(data, blk_mq_tags_from_data(data), tag,
512 alloc_time_ns);
d2c0d383
CH
513}
514
4b6a5d9c
JA
515static struct request *blk_mq_rq_cache_fill(struct request_queue *q,
516 struct blk_plug *plug,
517 blk_opf_t opf,
518 blk_mq_req_flags_t flags)
320ae51f 519{
e6e7abff
CH
520 struct blk_mq_alloc_data data = {
521 .q = q,
522 .flags = flags,
16458cf3 523 .cmd_flags = opf,
4b6a5d9c
JA
524 .nr_tags = plug->nr_ios,
525 .cached_rq = &plug->cached_rq,
e6e7abff 526 };
bd166ef1 527 struct request *rq;
320ae51f 528
4b6a5d9c
JA
529 if (blk_queue_enter(q, flags))
530 return NULL;
531
532 plug->nr_ios = 1;
320ae51f 533
b90cfaed 534 rq = __blk_mq_alloc_requests(&data);
4b6a5d9c
JA
535 if (unlikely(!rq))
536 blk_queue_exit(q);
537 return rq;
538}
539
540static struct request *blk_mq_alloc_cached_request(struct request_queue *q,
541 blk_opf_t opf,
542 blk_mq_req_flags_t flags)
543{
544 struct blk_plug *plug = current->plug;
545 struct request *rq;
546
547 if (!plug)
548 return NULL;
40467282 549
4b6a5d9c
JA
550 if (rq_list_empty(plug->cached_rq)) {
551 if (plug->nr_ios == 1)
552 return NULL;
553 rq = blk_mq_rq_cache_fill(q, plug, opf, flags);
40467282
JC
554 if (!rq)
555 return NULL;
556 } else {
557 rq = rq_list_peek(&plug->cached_rq);
558 if (!rq || rq->q != q)
559 return NULL;
4b6a5d9c 560
40467282
JC
561 if (blk_mq_get_hctx_type(opf) != rq->mq_hctx->type)
562 return NULL;
563 if (op_is_flush(rq->cmd_flags) != op_is_flush(opf))
564 return NULL;
565
566 plug->cached_rq = rq_list_next(rq);
567 }
4b6a5d9c 568
4b6a5d9c
JA
569 rq->cmd_flags = opf;
570 INIT_LIST_HEAD(&rq->queuelist);
571 return rq;
572}
573
574struct request *blk_mq_alloc_request(struct request_queue *q, blk_opf_t opf,
575 blk_mq_req_flags_t flags)
576{
577 struct request *rq;
578
579 rq = blk_mq_alloc_cached_request(q, opf, flags);
580 if (!rq) {
581 struct blk_mq_alloc_data data = {
582 .q = q,
583 .flags = flags,
584 .cmd_flags = opf,
585 .nr_tags = 1,
586 };
587 int ret;
588
589 ret = blk_queue_enter(q, flags);
590 if (ret)
591 return ERR_PTR(ret);
592
593 rq = __blk_mq_alloc_requests(&data);
594 if (!rq)
595 goto out_queue_exit;
596 }
0c4de0f3
CH
597 rq->__data_len = 0;
598 rq->__sector = (sector_t) -1;
599 rq->bio = rq->biotail = NULL;
320ae51f 600 return rq;
a5ea5811
CH
601out_queue_exit:
602 blk_queue_exit(q);
603 return ERR_PTR(-EWOULDBLOCK);
320ae51f 604}
4bb659b1 605EXPORT_SYMBOL(blk_mq_alloc_request);
320ae51f 606
cd6ce148 607struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
16458cf3 608 blk_opf_t opf, blk_mq_req_flags_t flags, unsigned int hctx_idx)
1f5bd336 609{
e6e7abff
CH
610 struct blk_mq_alloc_data data = {
611 .q = q,
612 .flags = flags,
16458cf3 613 .cmd_flags = opf,
47c122e3 614 .nr_tags = 1,
e6e7abff 615 };
600c3b0c 616 u64 alloc_time_ns = 0;
e3c5a78c 617 struct request *rq;
6d2809d5 618 unsigned int cpu;
600c3b0c 619 unsigned int tag;
1f5bd336
ML
620 int ret;
621
600c3b0c
CH
622 /* alloc_time includes depth and tag waits */
623 if (blk_queue_rq_alloc_time(q))
624 alloc_time_ns = ktime_get_ns();
625
1f5bd336
ML
626 /*
627 * If the tag allocator sleeps we could get an allocation for a
628 * different hardware context. No need to complicate the low level
629 * allocator for this for the rare use case of a command tied to
630 * a specific queue.
631 */
6ee858a3
KS
632 if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT)) ||
633 WARN_ON_ONCE(!(flags & BLK_MQ_REQ_RESERVED)))
1f5bd336
ML
634 return ERR_PTR(-EINVAL);
635
636 if (hctx_idx >= q->nr_hw_queues)
637 return ERR_PTR(-EIO);
638
3a0a5299 639 ret = blk_queue_enter(q, flags);
1f5bd336
ML
640 if (ret)
641 return ERR_PTR(ret);
642
c8712c6a
CH
643 /*
644 * Check if the hardware context is actually mapped to anything.
645 * If not tell the caller that it should skip this queue.
646 */
a5ea5811 647 ret = -EXDEV;
4e5cc99e 648 data.hctx = xa_load(&q->hctx_table, hctx_idx);
e6e7abff 649 if (!blk_mq_hw_queue_mapped(data.hctx))
a5ea5811 650 goto out_queue_exit;
e6e7abff 651 cpu = cpumask_first_and(data.hctx->cpumask, cpu_online_mask);
14dc7a18
BVA
652 if (cpu >= nr_cpu_ids)
653 goto out_queue_exit;
e6e7abff 654 data.ctx = __blk_mq_get_ctx(q, cpu);
1f5bd336 655
dd6216bb
CH
656 if (q->elevator)
657 data.rq_flags |= RQF_SCHED_TAGS;
781dd830 658 else
dd6216bb 659 blk_mq_tag_busy(data.hctx);
600c3b0c 660
99e48cd6
JG
661 if (flags & BLK_MQ_REQ_RESERVED)
662 data.rq_flags |= RQF_RESV;
663
a5ea5811 664 ret = -EWOULDBLOCK;
600c3b0c
CH
665 tag = blk_mq_get_tag(&data);
666 if (tag == BLK_MQ_NO_TAG)
a5ea5811 667 goto out_queue_exit;
e3c5a78c 668 rq = blk_mq_rq_ctx_init(&data, blk_mq_tags_from_data(&data), tag,
fe6134f6 669 alloc_time_ns);
e3c5a78c
JG
670 rq->__data_len = 0;
671 rq->__sector = (sector_t) -1;
672 rq->bio = rq->biotail = NULL;
673 return rq;
600c3b0c 674
a5ea5811
CH
675out_queue_exit:
676 blk_queue_exit(q);
677 return ERR_PTR(ret);
1f5bd336
ML
678}
679EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx);
680
12f5b931
KB
681static void __blk_mq_free_request(struct request *rq)
682{
683 struct request_queue *q = rq->q;
684 struct blk_mq_ctx *ctx = rq->mq_ctx;
ea4f995e 685 struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
12f5b931
KB
686 const int sched_tag = rq->internal_tag;
687
a892c8d5 688 blk_crypto_free_request(rq);
986d413b 689 blk_pm_mark_last_busy(rq);
ea4f995e 690 rq->mq_hctx = NULL;
76647368 691 if (rq->tag != BLK_MQ_NO_TAG)
cae740a0 692 blk_mq_put_tag(hctx->tags, ctx, rq->tag);
76647368 693 if (sched_tag != BLK_MQ_NO_TAG)
cae740a0 694 blk_mq_put_tag(hctx->sched_tags, ctx, sched_tag);
12f5b931
KB
695 blk_mq_sched_restart(hctx);
696 blk_queue_exit(q);
697}
698
6af54051 699void blk_mq_free_request(struct request *rq)
320ae51f 700{
320ae51f 701 struct request_queue *q = rq->q;
ea4f995e 702 struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
6af54051 703
dd6216bb 704 if ((rq->rq_flags & RQF_USE_SCHED) &&
222ee581
CH
705 q->elevator->type->ops.finish_request)
706 q->elevator->type->ops.finish_request(rq);
320ae51f 707
e8064021 708 if (rq->rq_flags & RQF_MQ_INFLIGHT)
bccf5e26 709 __blk_mq_dec_active_requests(hctx);
87760e5e 710
7beb2f84 711 if (unlikely(laptop_mode && !blk_rq_is_passthrough(rq)))
d152c682 712 laptop_io_completion(q->disk->bdi);
7beb2f84 713
a7905043 714 rq_qos_done(q, rq);
0d2602ca 715
12f5b931 716 WRITE_ONCE(rq->state, MQ_RQ_IDLE);
0a467d0f 717 if (req_ref_put_and_test(rq))
12f5b931 718 __blk_mq_free_request(rq);
320ae51f 719}
1a3b595a 720EXPORT_SYMBOL_GPL(blk_mq_free_request);
320ae51f 721
47c122e3 722void blk_mq_free_plug_rqs(struct blk_plug *plug)
320ae51f 723{
013a7f95 724 struct request *rq;
fe1f4526 725
c5fc7b93 726 while ((rq = rq_list_pop(&plug->cached_rq)) != NULL)
47c122e3 727 blk_mq_free_request(rq);
47c122e3 728}
522a7775 729
22350ad7
CH
730void blk_dump_rq_flags(struct request *rq, char *msg)
731{
732 printk(KERN_INFO "%s: dev %s: flags=%llx\n", msg,
f3fa33ac 733 rq->q->disk ? rq->q->disk->disk_name : "?",
16458cf3 734 (__force unsigned long long) rq->cmd_flags);
22350ad7
CH
735
736 printk(KERN_INFO " sector %llu, nr/cnr %u/%u\n",
737 (unsigned long long)blk_rq_pos(rq),
738 blk_rq_sectors(rq), blk_rq_cur_sectors(rq));
739 printk(KERN_INFO " bio %p, biotail %p, len %u\n",
740 rq->bio, rq->biotail, blk_rq_bytes(rq));
741}
742EXPORT_SYMBOL(blk_dump_rq_flags);
743
9be3e06f
JA
744static void req_bio_endio(struct request *rq, struct bio *bio,
745 unsigned int nbytes, blk_status_t error)
746{
478eb72b 747 if (unlikely(error)) {
9be3e06f 748 bio->bi_status = error;
478eb72b 749 } else if (req_op(rq) == REQ_OP_ZONE_APPEND) {
9be3e06f
JA
750 /*
751 * Partial zone append completions cannot be supported as the
752 * BIO fragments may end up not being written sequentially.
753 */
297db731 754 if (bio->bi_iter.bi_size != nbytes)
9be3e06f
JA
755 bio->bi_status = BLK_STS_IOERR;
756 else
757 bio->bi_iter.bi_sector = rq->__sector;
758 }
759
478eb72b
PB
760 bio_advance(bio, nbytes);
761
762 if (unlikely(rq->rq_flags & RQF_QUIET))
763 bio_set_flag(bio, BIO_QUIET);
9be3e06f
JA
764 /* don't actually finish bio if it's part of flush sequence */
765 if (bio->bi_iter.bi_size == 0 && !(rq->rq_flags & RQF_FLUSH_SEQ))
766 bio_endio(bio);
767}
768
769static void blk_account_io_completion(struct request *req, unsigned int bytes)
770{
771 if (req->part && blk_do_io_stat(req)) {
772 const int sgrp = op_stat_group(req_op(req));
773
774 part_stat_lock();
775 part_stat_add(req->part, sectors[sgrp], bytes >> 9);
776 part_stat_unlock();
777 }
778}
779
0d7a29a2
CH
780static void blk_print_req_error(struct request *req, blk_status_t status)
781{
782 printk_ratelimited(KERN_ERR
783 "%s error, dev %s, sector %llu op 0x%x:(%s) flags 0x%x "
784 "phys_seg %u prio class %u\n",
785 blk_status_to_str(status),
f3fa33ac 786 req->q->disk ? req->q->disk->disk_name : "?",
16458cf3
BVA
787 blk_rq_pos(req), (__force u32)req_op(req),
788 blk_op_str(req_op(req)),
789 (__force u32)(req->cmd_flags & ~REQ_OP_MASK),
0d7a29a2
CH
790 req->nr_phys_segments,
791 IOPRIO_PRIO_CLASS(req->ioprio));
792}
793
5581a5dd
JA
794/*
795 * Fully end IO on a request. Does not support partial completions, or
796 * errors.
797 */
798static void blk_complete_request(struct request *req)
799{
800 const bool is_flush = (req->rq_flags & RQF_FLUSH_SEQ) != 0;
801 int total_bytes = blk_rq_bytes(req);
802 struct bio *bio = req->bio;
803
804 trace_block_rq_complete(req, BLK_STS_OK, total_bytes);
805
806 if (!bio)
807 return;
808
809#ifdef CONFIG_BLK_DEV_INTEGRITY
810 if (blk_integrity_rq(req) && req_op(req) == REQ_OP_READ)
811 req->q->integrity.profile->complete_fn(req, total_bytes);
812#endif
813
9cd1e566
EB
814 /*
815 * Upper layers may call blk_crypto_evict_key() anytime after the last
816 * bio_endio(). Therefore, the keyslot must be released before that.
817 */
818 blk_crypto_rq_put_keyslot(req);
819
5581a5dd
JA
820 blk_account_io_completion(req, total_bytes);
821
822 do {
823 struct bio *next = bio->bi_next;
824
825 /* Completion has already been traced */
826 bio_clear_flag(bio, BIO_TRACE_COMPLETION);
a12821d5
PR
827
828 if (req_op(req) == REQ_OP_ZONE_APPEND)
829 bio->bi_iter.bi_sector = req->__sector;
830
5581a5dd
JA
831 if (!is_flush)
832 bio_endio(bio);
833 bio = next;
834 } while (bio);
835
836 /*
837 * Reset counters so that the request stacking driver
838 * can find how many bytes remain in the request
839 * later.
840 */
ab3e1d3b
JA
841 if (!req->end_io) {
842 req->bio = NULL;
843 req->__data_len = 0;
844 }
5581a5dd
JA
845}
846
9be3e06f
JA
847/**
848 * blk_update_request - Complete multiple bytes without completing the request
849 * @req: the request being processed
850 * @error: block status code
851 * @nr_bytes: number of bytes to complete for @req
852 *
853 * Description:
854 * Ends I/O on a number of bytes attached to @req, but doesn't complete
855 * the request structure even if @req doesn't have leftover.
856 * If @req has leftover, sets it up for the next range of segments.
857 *
858 * Passing the result of blk_rq_bytes() as @nr_bytes guarantees
859 * %false return from this function.
860 *
861 * Note:
862 * The RQF_SPECIAL_PAYLOAD flag is ignored on purpose in this function
863 * except in the consistency check at the end of this function.
864 *
865 * Return:
866 * %false - this request doesn't have any more data
867 * %true - this request has more data
868 **/
869bool blk_update_request(struct request *req, blk_status_t error,
870 unsigned int nr_bytes)
871{
872 int total_bytes;
873
8a7d267b 874 trace_block_rq_complete(req, error, nr_bytes);
9be3e06f
JA
875
876 if (!req->bio)
877 return false;
878
879#ifdef CONFIG_BLK_DEV_INTEGRITY
880 if (blk_integrity_rq(req) && req_op(req) == REQ_OP_READ &&
881 error == BLK_STS_OK)
882 req->q->integrity.profile->complete_fn(req, nr_bytes);
883#endif
884
9cd1e566
EB
885 /*
886 * Upper layers may call blk_crypto_evict_key() anytime after the last
887 * bio_endio(). Therefore, the keyslot must be released before that.
888 */
889 if (blk_crypto_rq_has_keyslot(req) && nr_bytes >= blk_rq_bytes(req))
890 __blk_crypto_rq_put_keyslot(req);
891
9be3e06f 892 if (unlikely(error && !blk_rq_is_passthrough(req) &&
3d973a76
CH
893 !(req->rq_flags & RQF_QUIET)) &&
894 !test_bit(GD_DEAD, &req->q->disk->state)) {
9be3e06f 895 blk_print_req_error(req, error);
d5869fdc
YS
896 trace_block_rq_error(req, error, nr_bytes);
897 }
9be3e06f
JA
898
899 blk_account_io_completion(req, nr_bytes);
900
901 total_bytes = 0;
902 while (req->bio) {
903 struct bio *bio = req->bio;
904 unsigned bio_bytes = min(bio->bi_iter.bi_size, nr_bytes);
905
906 if (bio_bytes == bio->bi_iter.bi_size)
907 req->bio = bio->bi_next;
908
909 /* Completion has already been traced */
910 bio_clear_flag(bio, BIO_TRACE_COMPLETION);
911 req_bio_endio(req, bio, bio_bytes, error);
912
913 total_bytes += bio_bytes;
914 nr_bytes -= bio_bytes;
915
916 if (!nr_bytes)
917 break;
918 }
919
920 /*
921 * completely done
922 */
923 if (!req->bio) {
924 /*
925 * Reset counters so that the request stacking driver
926 * can find how many bytes remain in the request
927 * later.
928 */
929 req->__data_len = 0;
930 return false;
931 }
932
933 req->__data_len -= total_bytes;
934
935 /* update sector only for requests with clear definition of sector */
936 if (!blk_rq_is_passthrough(req))
937 req->__sector += total_bytes >> 9;
938
939 /* mixed attributes always follow the first bio */
940 if (req->rq_flags & RQF_MIXED_MERGE) {
941 req->cmd_flags &= ~REQ_FAILFAST_MASK;
942 req->cmd_flags |= req->bio->bi_opf & REQ_FAILFAST_MASK;
943 }
944
945 if (!(req->rq_flags & RQF_SPECIAL_PAYLOAD)) {
946 /*
947 * If total number of sectors is less than the first segment
948 * size, something has gone terribly wrong.
949 */
950 if (blk_rq_bytes(req) < blk_rq_cur_bytes(req)) {
951 blk_dump_rq_flags(req, "request botched");
952 req->__data_len = blk_rq_cur_bytes(req);
953 }
954
955 /* recalculate the number of segments */
956 req->nr_phys_segments = blk_recalc_rq_segments(req);
957 }
958
959 return true;
960}
961EXPORT_SYMBOL_GPL(blk_update_request);
962
450b7879
CH
963static inline void blk_account_io_done(struct request *req, u64 now)
964{
5a80bd07
HC
965 trace_block_io_done(req);
966
450b7879
CH
967 /*
968 * Account IO completion. flush_rq isn't accounted as a
969 * normal IO on queueing nor completion. Accounting the
970 * containing request is enough.
971 */
972 if (blk_do_io_stat(req) && req->part &&
06965037
CK
973 !(req->rq_flags & RQF_FLUSH_SEQ)) {
974 const int sgrp = op_stat_group(req_op(req));
450b7879 975
06965037
CK
976 part_stat_lock();
977 update_io_ticks(req->part, jiffies, true);
978 part_stat_inc(req->part, ios[sgrp]);
979 part_stat_add(req->part, nsecs[sgrp], now - req->start_time_ns);
980 part_stat_unlock();
981 }
450b7879
CH
982}
983
984static inline void blk_account_io_start(struct request *req)
985{
5a80bd07
HC
986 trace_block_io_start(req);
987
e165fb4d
CK
988 if (blk_do_io_stat(req)) {
989 /*
990 * All non-passthrough requests are created from a bio with one
991 * exception: when a flush command that is part of a flush sequence
992 * generated by the state machine in blk-flush.c is cloned onto the
993 * lower device by dm-multipath we can get here without a bio.
994 */
995 if (req->bio)
996 req->part = req->bio->bi_bdev;
997 else
998 req->part = req->q->disk->part0;
999
1000 part_stat_lock();
1001 update_io_ticks(req->part, jiffies, false);
1002 part_stat_unlock();
1003 }
450b7879
CH
1004}
1005
f794f335 1006static inline void __blk_mq_end_request_acct(struct request *rq, u64 now)
320ae51f 1007{
54bdd67d 1008 if (rq->rq_flags & RQF_STATS)
522a7775 1009 blk_stat_add(rq, now);
4bc6339a 1010
87890092 1011 blk_mq_sched_completed_request(rq, now);
522a7775 1012 blk_account_io_done(rq, now);
f794f335 1013}
522a7775 1014
f794f335
JA
1015inline void __blk_mq_end_request(struct request *rq, blk_status_t error)
1016{
1017 if (blk_mq_need_time_stamp(rq))
1018 __blk_mq_end_request_acct(rq, ktime_get_ns());
0d11e6ac 1019
91b63639 1020 if (rq->end_io) {
a7905043 1021 rq_qos_done(rq->q, rq);
de671d61
JA
1022 if (rq->end_io(rq, error) == RQ_END_IO_FREE)
1023 blk_mq_free_request(rq);
91b63639 1024 } else {
320ae51f 1025 blk_mq_free_request(rq);
91b63639 1026 }
320ae51f 1027}
c8a446ad 1028EXPORT_SYMBOL(__blk_mq_end_request);
63151a44 1029
2a842aca 1030void blk_mq_end_request(struct request *rq, blk_status_t error)
63151a44
CH
1031{
1032 if (blk_update_request(rq, error, blk_rq_bytes(rq)))
1033 BUG();
c8a446ad 1034 __blk_mq_end_request(rq, error);
63151a44 1035}
c8a446ad 1036EXPORT_SYMBOL(blk_mq_end_request);
320ae51f 1037
f794f335
JA
1038#define TAG_COMP_BATCH 32
1039
1040static inline void blk_mq_flush_tag_batch(struct blk_mq_hw_ctx *hctx,
1041 int *tag_array, int nr_tags)
1042{
1043 struct request_queue *q = hctx->queue;
1044
3b87c6ea
ML
1045 /*
1046 * All requests should have been marked as RQF_MQ_INFLIGHT, so
1047 * update hctx->nr_active in batch
1048 */
1049 if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
1050 __blk_mq_sub_active_requests(hctx, nr_tags);
1051
f794f335
JA
1052 blk_mq_put_tags(hctx->tags, tag_array, nr_tags);
1053 percpu_ref_put_many(&q->q_usage_counter, nr_tags);
1054}
1055
1056void blk_mq_end_request_batch(struct io_comp_batch *iob)
1057{
1058 int tags[TAG_COMP_BATCH], nr_tags = 0;
02f7eab0 1059 struct blk_mq_hw_ctx *cur_hctx = NULL;
f794f335
JA
1060 struct request *rq;
1061 u64 now = 0;
1062
1063 if (iob->need_ts)
1064 now = ktime_get_ns();
1065
1066 while ((rq = rq_list_pop(&iob->req_list)) != NULL) {
1067 prefetch(rq->bio);
1068 prefetch(rq->rq_next);
1069
5581a5dd 1070 blk_complete_request(rq);
f794f335
JA
1071 if (iob->need_ts)
1072 __blk_mq_end_request_acct(rq, now);
1073
98b26a0e
JA
1074 rq_qos_done(rq->q, rq);
1075
ab3e1d3b
JA
1076 /*
1077 * If end_io handler returns NONE, then it still has
1078 * ownership of the request.
1079 */
1080 if (rq->end_io && rq->end_io(rq, 0) == RQ_END_IO_NONE)
1081 continue;
1082
f794f335 1083 WRITE_ONCE(rq->state, MQ_RQ_IDLE);
0a467d0f 1084 if (!req_ref_put_and_test(rq))
f794f335
JA
1085 continue;
1086
1087 blk_crypto_free_request(rq);
1088 blk_pm_mark_last_busy(rq);
f794f335 1089
02f7eab0
JA
1090 if (nr_tags == TAG_COMP_BATCH || cur_hctx != rq->mq_hctx) {
1091 if (cur_hctx)
1092 blk_mq_flush_tag_batch(cur_hctx, tags, nr_tags);
f794f335 1093 nr_tags = 0;
02f7eab0 1094 cur_hctx = rq->mq_hctx;
f794f335
JA
1095 }
1096 tags[nr_tags++] = rq->tag;
f794f335
JA
1097 }
1098
1099 if (nr_tags)
02f7eab0 1100 blk_mq_flush_tag_batch(cur_hctx, tags, nr_tags);
f794f335
JA
1101}
1102EXPORT_SYMBOL_GPL(blk_mq_end_request_batch);
1103
f9ab4918 1104static void blk_complete_reqs(struct llist_head *list)
320ae51f 1105{
f9ab4918
SAS
1106 struct llist_node *entry = llist_reverse_order(llist_del_all(list));
1107 struct request *rq, *next;
c3077b5d 1108
f9ab4918 1109 llist_for_each_entry_safe(rq, next, entry, ipi_list)
c3077b5d 1110 rq->q->mq_ops->complete(rq);
320ae51f 1111}
320ae51f 1112
f9ab4918 1113static __latent_entropy void blk_done_softirq(struct softirq_action *h)
320ae51f 1114{
f9ab4918 1115 blk_complete_reqs(this_cpu_ptr(&blk_cpu_done));
115243f5
CH
1116}
1117
c3077b5d
CH
1118static int blk_softirq_cpu_dead(unsigned int cpu)
1119{
f9ab4918 1120 blk_complete_reqs(&per_cpu(blk_cpu_done, cpu));
c3077b5d
CH
1121 return 0;
1122}
1123
40d09b53 1124static void __blk_mq_complete_request_remote(void *data)
c3077b5d 1125{
f9ab4918 1126 __raise_softirq_irqoff(BLOCK_SOFTIRQ);
c3077b5d
CH
1127}
1128
96339526
CH
1129static inline bool blk_mq_complete_need_ipi(struct request *rq)
1130{
1131 int cpu = raw_smp_processor_id();
1132
1133 if (!IS_ENABLED(CONFIG_SMP) ||
1134 !test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags))
1135 return false;
71425189
SAS
1136 /*
1137 * With force threaded interrupts enabled, raising softirq from an SMP
1138 * function call will always result in waking the ksoftirqd thread.
1139 * This is probably worse than completing the request on a different
1140 * cache domain.
1141 */
91cc470e 1142 if (force_irqthreads())
71425189 1143 return false;
96339526
CH
1144
1145 /* same CPU or cache domain? Complete locally */
1146 if (cpu == rq->mq_ctx->cpu ||
1147 (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags) &&
1148 cpus_share_cache(cpu, rq->mq_ctx->cpu)))
1149 return false;
1150
1151 /* don't try to IPI to an offline CPU */
1152 return cpu_online(rq->mq_ctx->cpu);
1153}
1154
f9ab4918
SAS
1155static void blk_mq_complete_send_ipi(struct request *rq)
1156{
1157 struct llist_head *list;
1158 unsigned int cpu;
1159
1160 cpu = rq->mq_ctx->cpu;
1161 list = &per_cpu(blk_cpu_done, cpu);
1162 if (llist_add(&rq->ipi_list, list)) {
1163 INIT_CSD(&rq->csd, __blk_mq_complete_request_remote, rq);
1164 smp_call_function_single_async(cpu, &rq->csd);
1165 }
1166}
1167
1168static void blk_mq_raise_softirq(struct request *rq)
1169{
1170 struct llist_head *list;
1171
1172 preempt_disable();
1173 list = this_cpu_ptr(&blk_cpu_done);
1174 if (llist_add(&rq->ipi_list, list))
1175 raise_softirq(BLOCK_SOFTIRQ);
1176 preempt_enable();
1177}
1178
40d09b53 1179bool blk_mq_complete_request_remote(struct request *rq)
320ae51f 1180{
af78ff7c 1181 WRITE_ONCE(rq->state, MQ_RQ_COMPLETE);
36e76539 1182
4ab32bf3 1183 /*
f168420c
LS
1184 * For request which hctx has only one ctx mapping,
1185 * or a polled request, always complete locally,
1186 * it's pointless to redirect the completion.
4ab32bf3 1187 */
30654614
ET
1188 if ((rq->mq_hctx->nr_ctx == 1 &&
1189 rq->mq_ctx->cpu == raw_smp_processor_id()) ||
1190 rq->cmd_flags & REQ_POLLED)
40d09b53 1191 return false;
38535201 1192
96339526 1193 if (blk_mq_complete_need_ipi(rq)) {
f9ab4918
SAS
1194 blk_mq_complete_send_ipi(rq);
1195 return true;
3d6efbf6 1196 }
40d09b53 1197
f9ab4918
SAS
1198 if (rq->q->nr_hw_queues == 1) {
1199 blk_mq_raise_softirq(rq);
1200 return true;
1201 }
1202 return false;
40d09b53
CH
1203}
1204EXPORT_SYMBOL_GPL(blk_mq_complete_request_remote);
1205
1206/**
1207 * blk_mq_complete_request - end I/O on a request
1208 * @rq: the request being processed
1209 *
1210 * Description:
1211 * Complete a request by scheduling the ->complete_rq operation.
1212 **/
1213void blk_mq_complete_request(struct request *rq)
1214{
1215 if (!blk_mq_complete_request_remote(rq))
1216 rq->q->mq_ops->complete(rq);
320ae51f 1217}
15f73f5b 1218EXPORT_SYMBOL(blk_mq_complete_request);
30a91cb4 1219
105663f7
AA
1220/**
1221 * blk_mq_start_request - Start processing a request
1222 * @rq: Pointer to request to be started
1223 *
1224 * Function used by device drivers to notify the block layer that a request
1225 * is going to be processed now, so blk layer can do proper initializations
1226 * such as starting the timeout timer.
1227 */
e2490073 1228void blk_mq_start_request(struct request *rq)
320ae51f
JA
1229{
1230 struct request_queue *q = rq->q;
1231
a54895fa 1232 trace_block_rq_issue(rq);
320ae51f 1233
cf43e6be 1234 if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags)) {
4cddeaca 1235 rq->io_start_time_ns = ktime_get_ns();
3d244306 1236 rq->stats_sectors = blk_rq_sectors(rq);
cf43e6be 1237 rq->rq_flags |= RQF_STATS;
a7905043 1238 rq_qos_issue(q, rq);
cf43e6be
JA
1239 }
1240
1d9bd516 1241 WARN_ON_ONCE(blk_mq_rq_state(rq) != MQ_RQ_IDLE);
538b7534 1242
1d9bd516 1243 blk_add_timer(rq);
12f5b931 1244 WRITE_ONCE(rq->state, MQ_RQ_IN_FLIGHT);
49f5baa5 1245
54d4e6ab
MG
1246#ifdef CONFIG_BLK_DEV_INTEGRITY
1247 if (blk_integrity_rq(rq) && req_op(rq) == REQ_OP_WRITE)
1248 q->integrity.profile->prepare_fn(rq);
1249#endif
3e08773c
CH
1250 if (rq->bio && rq->bio->bi_opf & REQ_POLLED)
1251 WRITE_ONCE(rq->bio->bi_cookie, blk_rq_to_qc(rq));
320ae51f 1252}
e2490073 1253EXPORT_SYMBOL(blk_mq_start_request);
320ae51f 1254
a327c341
ML
1255/*
1256 * Allow 2x BLK_MAX_REQUEST_COUNT requests on plug queue for multiple
1257 * queues. This is important for md arrays to benefit from merging
1258 * requests.
1259 */
1260static inline unsigned short blk_plug_max_rq_count(struct blk_plug *plug)
1261{
1262 if (plug->multiple_queues)
1263 return BLK_MAX_REQUEST_COUNT * 2;
1264 return BLK_MAX_REQUEST_COUNT;
1265}
1266
1267static void blk_add_rq_to_plug(struct blk_plug *plug, struct request *rq)
1268{
1269 struct request *last = rq_list_peek(&plug->mq_list);
1270
1271 if (!plug->rq_count) {
1272 trace_block_plug(rq->q);
1273 } else if (plug->rq_count >= blk_plug_max_rq_count(plug) ||
1274 (!blk_queue_nomerges(rq->q) &&
1275 blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE)) {
1276 blk_mq_flush_plug_list(plug, false);
878eb6e4 1277 last = NULL;
a327c341
ML
1278 trace_block_plug(rq->q);
1279 }
1280
1281 if (!plug->multiple_queues && last && last->q != rq->q)
1282 plug->multiple_queues = true;
c6b7a3a2
ML
1283 /*
1284 * Any request allocated from sched tags can't be issued to
1285 * ->queue_rqs() directly
1286 */
1287 if (!plug->has_elevator && (rq->rq_flags & RQF_SCHED_TAGS))
a327c341
ML
1288 plug->has_elevator = true;
1289 rq->rq_next = NULL;
1290 rq_list_add(&plug->mq_list, rq);
1291 plug->rq_count++;
1292}
1293
4054cff9
CH
1294/**
1295 * blk_execute_rq_nowait - insert a request to I/O scheduler for execution
4054cff9
CH
1296 * @rq: request to insert
1297 * @at_head: insert request at head or tail of queue
4054cff9
CH
1298 *
1299 * Description:
1300 * Insert a fully prepared request at the back of the I/O scheduler queue
1301 * for execution. Don't wait for completion.
1302 *
1303 * Note:
1304 * This function will invoke @done directly if the queue is dead.
1305 */
e2e53086 1306void blk_execute_rq_nowait(struct request *rq, bool at_head)
4054cff9 1307{
f0dbe6e8
CH
1308 struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
1309
ae948fd6
CH
1310 WARN_ON(irqs_disabled());
1311 WARN_ON(!blk_rq_is_passthrough(rq));
4054cff9 1312
ae948fd6 1313 blk_account_io_start(rq);
110fdb44
PR
1314
1315 /*
1316 * As plugging can be enabled for passthrough requests on a zoned
1317 * device, directly accessing the plug instead of using blk_mq_plug()
1318 * should not have any consequences.
1319 */
f0dbe6e8 1320 if (current->plug && !at_head) {
ae948fd6 1321 blk_add_rq_to_plug(current->plug, rq);
f0dbe6e8
CH
1322 return;
1323 }
1324
710fa378 1325 blk_mq_insert_request(rq, at_head ? BLK_MQ_INSERT_AT_HEAD : 0);
f0dbe6e8 1326 blk_mq_run_hw_queue(hctx, false);
4054cff9
CH
1327}
1328EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
1329
32ac5a9b
CH
1330struct blk_rq_wait {
1331 struct completion done;
1332 blk_status_t ret;
1333};
1334
de671d61 1335static enum rq_end_io_ret blk_end_sync_rq(struct request *rq, blk_status_t ret)
32ac5a9b
CH
1336{
1337 struct blk_rq_wait *wait = rq->end_io_data;
1338
1339 wait->ret = ret;
1340 complete(&wait->done);
de671d61 1341 return RQ_END_IO_NONE;
32ac5a9b
CH
1342}
1343
c6e99ea4 1344bool blk_rq_is_poll(struct request *rq)
4054cff9
CH
1345{
1346 if (!rq->mq_hctx)
1347 return false;
1348 if (rq->mq_hctx->type != HCTX_TYPE_POLL)
1349 return false;
4054cff9
CH
1350 return true;
1351}
c6e99ea4 1352EXPORT_SYMBOL_GPL(blk_rq_is_poll);
4054cff9
CH
1353
1354static void blk_rq_poll_completion(struct request *rq, struct completion *wait)
1355{
1356 do {
38a8c4d1 1357 blk_mq_poll(rq->q, blk_rq_to_qc(rq), NULL, 0);
4054cff9
CH
1358 cond_resched();
1359 } while (!completion_done(wait));
1360}
1361
1362/**
1363 * blk_execute_rq - insert a request into queue for execution
4054cff9
CH
1364 * @rq: request to insert
1365 * @at_head: insert request at head or tail of queue
1366 *
1367 * Description:
1368 * Insert a fully prepared request at the back of the I/O scheduler queue
1369 * for execution and wait for completion.
1370 * Return: The blk_status_t result provided to blk_mq_end_request().
1371 */
b84ba30b 1372blk_status_t blk_execute_rq(struct request *rq, bool at_head)
4054cff9 1373{
f0dbe6e8 1374 struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
32ac5a9b
CH
1375 struct blk_rq_wait wait = {
1376 .done = COMPLETION_INITIALIZER_ONSTACK(wait.done),
1377 };
4054cff9 1378
ae948fd6
CH
1379 WARN_ON(irqs_disabled());
1380 WARN_ON(!blk_rq_is_passthrough(rq));
4054cff9
CH
1381
1382 rq->end_io_data = &wait;
ae948fd6 1383 rq->end_io = blk_end_sync_rq;
4054cff9 1384
ae948fd6 1385 blk_account_io_start(rq);
710fa378 1386 blk_mq_insert_request(rq, at_head ? BLK_MQ_INSERT_AT_HEAD : 0);
f0dbe6e8 1387 blk_mq_run_hw_queue(hctx, false);
4054cff9 1388
ae948fd6 1389 if (blk_rq_is_poll(rq)) {
32ac5a9b 1390 blk_rq_poll_completion(rq, &wait.done);
ae948fd6
CH
1391 } else {
1392 /*
1393 * Prevent hang_check timer from firing at us during very long
1394 * I/O
1395 */
1396 unsigned long hang_check = sysctl_hung_task_timeout_secs;
1397
1398 if (hang_check)
32ac5a9b 1399 while (!wait_for_completion_io_timeout(&wait.done,
ae948fd6
CH
1400 hang_check * (HZ/2)))
1401 ;
1402 else
32ac5a9b 1403 wait_for_completion_io(&wait.done);
ae948fd6 1404 }
4054cff9 1405
32ac5a9b 1406 return wait.ret;
4054cff9
CH
1407}
1408EXPORT_SYMBOL(blk_execute_rq);
1409
ed0791b2 1410static void __blk_mq_requeue_request(struct request *rq)
320ae51f
JA
1411{
1412 struct request_queue *q = rq->q;
1413
923218f6
ML
1414 blk_mq_put_driver_tag(rq);
1415
a54895fa 1416 trace_block_rq_requeue(rq);
a7905043 1417 rq_qos_requeue(q, rq);
49f5baa5 1418
12f5b931
KB
1419 if (blk_mq_request_started(rq)) {
1420 WRITE_ONCE(rq->state, MQ_RQ_IDLE);
da661267 1421 rq->rq_flags &= ~RQF_TIMED_OUT;
e2490073 1422 }
320ae51f
JA
1423}
1424
2b053aca 1425void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list)
ed0791b2 1426{
214a4418 1427 struct request_queue *q = rq->q;
9a67aa52 1428 unsigned long flags;
214a4418 1429
ed0791b2 1430 __blk_mq_requeue_request(rq);
ed0791b2 1431
105976f5
ML
1432 /* this request will be re-inserted to io scheduler queue */
1433 blk_mq_sched_requeue_request(rq);
1434
9a67aa52
CH
1435 spin_lock_irqsave(&q->requeue_lock, flags);
1436 list_add_tail(&rq->queuelist, &q->requeue_list);
1437 spin_unlock_irqrestore(&q->requeue_lock, flags);
214a4418
CH
1438
1439 if (kick_requeue_list)
1440 blk_mq_kick_requeue_list(q);
ed0791b2
CH
1441}
1442EXPORT_SYMBOL(blk_mq_requeue_request);
1443
6fca6a61
CH
1444static void blk_mq_requeue_work(struct work_struct *work)
1445{
1446 struct request_queue *q =
2849450a 1447 container_of(work, struct request_queue, requeue_work.work);
6fca6a61 1448 LIST_HEAD(rq_list);
9a67aa52
CH
1449 LIST_HEAD(flush_list);
1450 struct request *rq;
6fca6a61 1451
18e9781d 1452 spin_lock_irq(&q->requeue_lock);
6fca6a61 1453 list_splice_init(&q->requeue_list, &rq_list);
9a67aa52 1454 list_splice_init(&q->flush_list, &flush_list);
18e9781d 1455 spin_unlock_irq(&q->requeue_lock);
6fca6a61 1456
9a67aa52
CH
1457 while (!list_empty(&rq_list)) {
1458 rq = list_entry(rq_list.next, struct request, queuelist);
aef1897c 1459 /*
a1e948b8
CH
1460 * If RQF_DONTPREP ist set, the request has been started by the
1461 * driver already and might have driver-specific data allocated
1462 * already. Insert it into the hctx dispatch list to avoid
1463 * block layer merges for the request.
aef1897c 1464 */
a1e948b8 1465 if (rq->rq_flags & RQF_DONTPREP) {
a1e948b8 1466 list_del_init(&rq->queuelist);
2b597613 1467 blk_mq_request_bypass_insert(rq, 0);
9a67aa52 1468 } else {
a1e948b8 1469 list_del_init(&rq->queuelist);
710fa378 1470 blk_mq_insert_request(rq, BLK_MQ_INSERT_AT_HEAD);
a1e948b8 1471 }
6fca6a61
CH
1472 }
1473
9a67aa52
CH
1474 while (!list_empty(&flush_list)) {
1475 rq = list_entry(flush_list.next, struct request, queuelist);
6fca6a61 1476 list_del_init(&rq->queuelist);
710fa378 1477 blk_mq_insert_request(rq, 0);
6fca6a61
CH
1478 }
1479
52d7f1b5 1480 blk_mq_run_hw_queues(q, false);
6fca6a61
CH
1481}
1482
6fca6a61
CH
1483void blk_mq_kick_requeue_list(struct request_queue *q)
1484{
ae943d20 1485 kblockd_mod_delayed_work_on(WORK_CPU_UNBOUND, &q->requeue_work, 0);
6fca6a61
CH
1486}
1487EXPORT_SYMBOL(blk_mq_kick_requeue_list);
1488
2849450a
MS
1489void blk_mq_delay_kick_requeue_list(struct request_queue *q,
1490 unsigned long msecs)
1491{
d4acf365
BVA
1492 kblockd_mod_delayed_work_on(WORK_CPU_UNBOUND, &q->requeue_work,
1493 msecs_to_jiffies(msecs));
2849450a
MS
1494}
1495EXPORT_SYMBOL(blk_mq_delay_kick_requeue_list);
1496
2dd6532e 1497static bool blk_mq_rq_inflight(struct request *rq, void *priv)
ae879912
JA
1498{
1499 /*
8ab30a33
JG
1500 * If we find a request that isn't idle we know the queue is busy
1501 * as it's checked in the iter.
1502 * Return false to stop the iteration.
ae879912 1503 */
8ab30a33 1504 if (blk_mq_request_started(rq)) {
ae879912
JA
1505 bool *busy = priv;
1506
1507 *busy = true;
1508 return false;
1509 }
1510
1511 return true;
1512}
1513
3c94d83c 1514bool blk_mq_queue_inflight(struct request_queue *q)
ae879912
JA
1515{
1516 bool busy = false;
1517
3c94d83c 1518 blk_mq_queue_tag_busy_iter(q, blk_mq_rq_inflight, &busy);
ae879912
JA
1519 return busy;
1520}
3c94d83c 1521EXPORT_SYMBOL_GPL(blk_mq_queue_inflight);
ae879912 1522
9bdb4833 1523static void blk_mq_rq_timed_out(struct request *req)
320ae51f 1524{
da661267 1525 req->rq_flags |= RQF_TIMED_OUT;
d1210d5a
CH
1526 if (req->q->mq_ops->timeout) {
1527 enum blk_eh_timer_return ret;
1528
9bdb4833 1529 ret = req->q->mq_ops->timeout(req);
d1210d5a
CH
1530 if (ret == BLK_EH_DONE)
1531 return;
1532 WARN_ON_ONCE(ret != BLK_EH_RESET_TIMER);
46f92d42 1533 }
d1210d5a
CH
1534
1535 blk_add_timer(req);
87ee7b11 1536}
5b3f25fc 1537
82c22947
DJ
1538struct blk_expired_data {
1539 bool has_timedout_rq;
1540 unsigned long next;
1541 unsigned long timeout_start;
1542};
1543
1544static bool blk_mq_req_expired(struct request *rq, struct blk_expired_data *expired)
81481eb4 1545{
12f5b931 1546 unsigned long deadline;
87ee7b11 1547
12f5b931
KB
1548 if (blk_mq_rq_state(rq) != MQ_RQ_IN_FLIGHT)
1549 return false;
da661267
CH
1550 if (rq->rq_flags & RQF_TIMED_OUT)
1551 return false;
a7af0af3 1552
079076b3 1553 deadline = READ_ONCE(rq->deadline);
82c22947 1554 if (time_after_eq(expired->timeout_start, deadline))
12f5b931 1555 return true;
a7af0af3 1556
82c22947
DJ
1557 if (expired->next == 0)
1558 expired->next = deadline;
1559 else if (time_after(expired->next, deadline))
1560 expired->next = deadline;
12f5b931 1561 return false;
87ee7b11
JA
1562}
1563
2e315dc0
ML
1564void blk_mq_put_rq_ref(struct request *rq)
1565{
de671d61
JA
1566 if (is_flush_rq(rq)) {
1567 if (rq->end_io(rq, 0) == RQ_END_IO_FREE)
1568 blk_mq_free_request(rq);
1569 } else if (req_ref_put_and_test(rq)) {
2e315dc0 1570 __blk_mq_free_request(rq);
de671d61 1571 }
2e315dc0
ML
1572}
1573
2dd6532e 1574static bool blk_mq_check_expired(struct request *rq, void *priv)
1d9bd516 1575{
82c22947 1576 struct blk_expired_data *expired = priv;
12f5b931
KB
1577
1578 /*
c797b40c
ML
1579 * blk_mq_queue_tag_busy_iter() has locked the request, so it cannot
1580 * be reallocated underneath the timeout handler's processing, then
1581 * the expire check is reliable. If the request is not expired, then
1582 * it was completed and reallocated as a new request after returning
1583 * from blk_mq_check_expired().
1d9bd516 1584 */
82c22947
DJ
1585 if (blk_mq_req_expired(rq, expired)) {
1586 expired->has_timedout_rq = true;
1587 return false;
1588 }
1589 return true;
1590}
1591
1592static bool blk_mq_handle_expired(struct request *rq, void *priv)
1593{
1594 struct blk_expired_data *expired = priv;
1595
1596 if (blk_mq_req_expired(rq, expired))
9bdb4833 1597 blk_mq_rq_timed_out(rq);
7baa8572 1598 return true;
1d9bd516
TH
1599}
1600
287922eb 1601static void blk_mq_timeout_work(struct work_struct *work)
320ae51f 1602{
287922eb
CH
1603 struct request_queue *q =
1604 container_of(work, struct request_queue, timeout_work);
82c22947
DJ
1605 struct blk_expired_data expired = {
1606 .timeout_start = jiffies,
1607 };
1d9bd516 1608 struct blk_mq_hw_ctx *hctx;
4f481208 1609 unsigned long i;
320ae51f 1610
71f79fb3
GKB
1611 /* A deadlock might occur if a request is stuck requiring a
1612 * timeout at the same time a queue freeze is waiting
1613 * completion, since the timeout code would not be able to
1614 * acquire the queue reference here.
1615 *
1616 * That's why we don't use blk_queue_enter here; instead, we use
1617 * percpu_ref_tryget directly, because we need to be able to
1618 * obtain a reference even in the short window between the queue
1619 * starting to freeze, by dropping the first reference in
1671d522 1620 * blk_freeze_queue_start, and the moment the last request is
71f79fb3
GKB
1621 * consumed, marked by the instant q_usage_counter reaches
1622 * zero.
1623 */
1624 if (!percpu_ref_tryget(&q->q_usage_counter))
287922eb
CH
1625 return;
1626
82c22947
DJ
1627 /* check if there is any timed-out request */
1628 blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &expired);
1629 if (expired.has_timedout_rq) {
1630 /*
1631 * Before walking tags, we must ensure any submit started
1632 * before the current time has finished. Since the submit
1633 * uses srcu or rcu, wait for a synchronization point to
1634 * ensure all running submits have finished
1635 */
483239c7 1636 blk_mq_wait_quiesce_done(q->tag_set);
82c22947
DJ
1637
1638 expired.next = 0;
1639 blk_mq_queue_tag_busy_iter(q, blk_mq_handle_expired, &expired);
1640 }
320ae51f 1641
82c22947
DJ
1642 if (expired.next != 0) {
1643 mod_timer(&q->timeout, expired.next);
0d2602ca 1644 } else {
fcd36c36
BVA
1645 /*
1646 * Request timeouts are handled as a forward rolling timer. If
1647 * we end up here it means that no requests are pending and
1648 * also that no request has been pending for a while. Mark
1649 * each hctx as idle.
1650 */
f054b56c
ML
1651 queue_for_each_hw_ctx(q, hctx, i) {
1652 /* the hctx may be unmapped, so check it here */
1653 if (blk_mq_hw_queue_mapped(hctx))
1654 blk_mq_tag_idle(hctx);
1655 }
0d2602ca 1656 }
287922eb 1657 blk_queue_exit(q);
320ae51f
JA
1658}
1659
88459642
OS
1660struct flush_busy_ctx_data {
1661 struct blk_mq_hw_ctx *hctx;
1662 struct list_head *list;
1663};
1664
1665static bool flush_busy_ctx(struct sbitmap *sb, unsigned int bitnr, void *data)
1666{
1667 struct flush_busy_ctx_data *flush_data = data;
1668 struct blk_mq_hw_ctx *hctx = flush_data->hctx;
1669 struct blk_mq_ctx *ctx = hctx->ctxs[bitnr];
c16d6b5a 1670 enum hctx_type type = hctx->type;
88459642 1671
88459642 1672 spin_lock(&ctx->lock);
c16d6b5a 1673 list_splice_tail_init(&ctx->rq_lists[type], flush_data->list);
e9a99a63 1674 sbitmap_clear_bit(sb, bitnr);
88459642
OS
1675 spin_unlock(&ctx->lock);
1676 return true;
1677}
1678
1429d7c9
JA
1679/*
1680 * Process software queues that have been marked busy, splicing them
1681 * to the for-dispatch
1682 */
2c3ad667 1683void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list)
1429d7c9 1684{
88459642
OS
1685 struct flush_busy_ctx_data data = {
1686 .hctx = hctx,
1687 .list = list,
1688 };
1429d7c9 1689
88459642 1690 sbitmap_for_each_set(&hctx->ctx_map, flush_busy_ctx, &data);
1429d7c9 1691}
2c3ad667 1692EXPORT_SYMBOL_GPL(blk_mq_flush_busy_ctxs);
1429d7c9 1693
b347689f
ML
1694struct dispatch_rq_data {
1695 struct blk_mq_hw_ctx *hctx;
1696 struct request *rq;
1697};
1698
1699static bool dispatch_rq_from_ctx(struct sbitmap *sb, unsigned int bitnr,
1700 void *data)
1701{
1702 struct dispatch_rq_data *dispatch_data = data;
1703 struct blk_mq_hw_ctx *hctx = dispatch_data->hctx;
1704 struct blk_mq_ctx *ctx = hctx->ctxs[bitnr];
c16d6b5a 1705 enum hctx_type type = hctx->type;
b347689f
ML
1706
1707 spin_lock(&ctx->lock);
c16d6b5a
ML
1708 if (!list_empty(&ctx->rq_lists[type])) {
1709 dispatch_data->rq = list_entry_rq(ctx->rq_lists[type].next);
b347689f 1710 list_del_init(&dispatch_data->rq->queuelist);
c16d6b5a 1711 if (list_empty(&ctx->rq_lists[type]))
b347689f
ML
1712 sbitmap_clear_bit(sb, bitnr);
1713 }
1714 spin_unlock(&ctx->lock);
1715
1716 return !dispatch_data->rq;
1717}
1718
1719struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
1720 struct blk_mq_ctx *start)
1721{
f31967f0 1722 unsigned off = start ? start->index_hw[hctx->type] : 0;
b347689f
ML
1723 struct dispatch_rq_data data = {
1724 .hctx = hctx,
1725 .rq = NULL,
1726 };
1727
1728 __sbitmap_for_each_set(&hctx->ctx_map, off,
1729 dispatch_rq_from_ctx, &data);
1730
1731 return data.rq;
1732}
1733
a808a9d5 1734static bool __blk_mq_alloc_driver_tag(struct request *rq)
570e9b73 1735{
ae0f1a73 1736 struct sbitmap_queue *bt = &rq->mq_hctx->tags->bitmap_tags;
570e9b73 1737 unsigned int tag_offset = rq->mq_hctx->tags->nr_reserved_tags;
570e9b73
ML
1738 int tag;
1739
568f2700
ML
1740 blk_mq_tag_busy(rq->mq_hctx);
1741
570e9b73 1742 if (blk_mq_tag_is_reserved(rq->mq_hctx->sched_tags, rq->internal_tag)) {
ae0f1a73 1743 bt = &rq->mq_hctx->tags->breserved_tags;
570e9b73 1744 tag_offset = 0;
28500850
ML
1745 } else {
1746 if (!hctx_may_queue(rq->mq_hctx, bt))
1747 return false;
570e9b73
ML
1748 }
1749
570e9b73
ML
1750 tag = __sbitmap_queue_get(bt);
1751 if (tag == BLK_MQ_NO_TAG)
1752 return false;
1753
1754 rq->tag = tag + tag_offset;
570e9b73
ML
1755 return true;
1756}
1757
a808a9d5 1758bool __blk_mq_get_driver_tag(struct blk_mq_hw_ctx *hctx, struct request *rq)
570e9b73 1759{
a808a9d5 1760 if (rq->tag == BLK_MQ_NO_TAG && !__blk_mq_alloc_driver_tag(rq))
568f2700
ML
1761 return false;
1762
51db1c37 1763 if ((hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) &&
568f2700
ML
1764 !(rq->rq_flags & RQF_MQ_INFLIGHT)) {
1765 rq->rq_flags |= RQF_MQ_INFLIGHT;
bccf5e26 1766 __blk_mq_inc_active_requests(hctx);
568f2700
ML
1767 }
1768 hctx->tags->rqs[rq->tag] = rq;
1769 return true;
570e9b73
ML
1770}
1771
eb619fdb
JA
1772static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode,
1773 int flags, void *key)
da55f2cc
OS
1774{
1775 struct blk_mq_hw_ctx *hctx;
1776
1777 hctx = container_of(wait, struct blk_mq_hw_ctx, dispatch_wait);
1778
5815839b 1779 spin_lock(&hctx->dispatch_wait_lock);
e8618575
JA
1780 if (!list_empty(&wait->entry)) {
1781 struct sbitmap_queue *sbq;
1782
1783 list_del_init(&wait->entry);
ae0f1a73 1784 sbq = &hctx->tags->bitmap_tags;
e8618575
JA
1785 atomic_dec(&sbq->ws_active);
1786 }
5815839b
ML
1787 spin_unlock(&hctx->dispatch_wait_lock);
1788
da55f2cc
OS
1789 blk_mq_run_hw_queue(hctx, true);
1790 return 1;
1791}
1792
f906a6a0
JA
1793/*
1794 * Mark us waiting for a tag. For shared tags, this involves hooking us into
ee3e4de5
BVA
1795 * the tag wakeups. For non-shared tags, we can simply mark us needing a
1796 * restart. For both cases, take care to check the condition again after
f906a6a0
JA
1797 * marking us as waiting.
1798 */
2278d69f 1799static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx *hctx,
f906a6a0 1800 struct request *rq)
da55f2cc 1801{
98b99e94 1802 struct sbitmap_queue *sbq;
5815839b 1803 struct wait_queue_head *wq;
f906a6a0
JA
1804 wait_queue_entry_t *wait;
1805 bool ret;
da55f2cc 1806
47df9ce9
KS
1807 if (!(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) &&
1808 !(blk_mq_is_shared_tags(hctx->flags))) {
684b7324 1809 blk_mq_sched_mark_restart_hctx(hctx);
f906a6a0 1810
c27d53fb
BVA
1811 /*
1812 * It's possible that a tag was freed in the window between the
1813 * allocation failure and adding the hardware queue to the wait
1814 * queue.
1815 *
1816 * Don't clear RESTART here, someone else could have set it.
1817 * At most this will cost an extra queue run.
1818 */
8ab6bb9e 1819 return blk_mq_get_driver_tag(rq);
eb619fdb 1820 }
eb619fdb 1821
2278d69f 1822 wait = &hctx->dispatch_wait;
c27d53fb
BVA
1823 if (!list_empty_careful(&wait->entry))
1824 return false;
1825
98b99e94
KS
1826 if (blk_mq_tag_is_reserved(rq->mq_hctx->sched_tags, rq->internal_tag))
1827 sbq = &hctx->tags->breserved_tags;
1828 else
1829 sbq = &hctx->tags->bitmap_tags;
e8618575 1830 wq = &bt_wait_ptr(sbq, hctx)->wait;
5815839b
ML
1831
1832 spin_lock_irq(&wq->lock);
1833 spin_lock(&hctx->dispatch_wait_lock);
c27d53fb 1834 if (!list_empty(&wait->entry)) {
5815839b
ML
1835 spin_unlock(&hctx->dispatch_wait_lock);
1836 spin_unlock_irq(&wq->lock);
c27d53fb 1837 return false;
eb619fdb
JA
1838 }
1839
e8618575 1840 atomic_inc(&sbq->ws_active);
5815839b
ML
1841 wait->flags &= ~WQ_FLAG_EXCLUSIVE;
1842 __add_wait_queue(wq, wait);
c27d53fb 1843
da55f2cc 1844 /*
eb619fdb
JA
1845 * It's possible that a tag was freed in the window between the
1846 * allocation failure and adding the hardware queue to the wait
1847 * queue.
da55f2cc 1848 */
8ab6bb9e 1849 ret = blk_mq_get_driver_tag(rq);
c27d53fb 1850 if (!ret) {
5815839b
ML
1851 spin_unlock(&hctx->dispatch_wait_lock);
1852 spin_unlock_irq(&wq->lock);
c27d53fb 1853 return false;
eb619fdb 1854 }
c27d53fb
BVA
1855
1856 /*
1857 * We got a tag, remove ourselves from the wait queue to ensure
1858 * someone else gets the wakeup.
1859 */
c27d53fb 1860 list_del_init(&wait->entry);
e8618575 1861 atomic_dec(&sbq->ws_active);
5815839b
ML
1862 spin_unlock(&hctx->dispatch_wait_lock);
1863 spin_unlock_irq(&wq->lock);
c27d53fb
BVA
1864
1865 return true;
da55f2cc
OS
1866}
1867
6e768717
ML
1868#define BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT 8
1869#define BLK_MQ_DISPATCH_BUSY_EWMA_FACTOR 4
1870/*
1871 * Update dispatch busy with the Exponential Weighted Moving Average(EWMA):
1872 * - EWMA is one simple way to compute running average value
1873 * - weight(7/8 and 1/8) is applied so that it can decrease exponentially
1874 * - take 4 as factor for avoiding to get too small(0) result, and this
1875 * factor doesn't matter because EWMA decreases exponentially
1876 */
1877static void blk_mq_update_dispatch_busy(struct blk_mq_hw_ctx *hctx, bool busy)
1878{
1879 unsigned int ewma;
1880
6e768717
ML
1881 ewma = hctx->dispatch_busy;
1882
1883 if (!ewma && !busy)
1884 return;
1885
1886 ewma *= BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT - 1;
1887 if (busy)
1888 ewma += 1 << BLK_MQ_DISPATCH_BUSY_EWMA_FACTOR;
1889 ewma /= BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT;
1890
1891 hctx->dispatch_busy = ewma;
1892}
1893
86ff7c2a
ML
1894#define BLK_MQ_RESOURCE_DELAY 3 /* ms units */
1895
c92a4103
JT
1896static void blk_mq_handle_dev_resource(struct request *rq,
1897 struct list_head *list)
1898{
c92a4103
JT
1899 list_add(&rq->queuelist, list);
1900 __blk_mq_requeue_request(rq);
1901}
1902
0512a75b
KB
1903static void blk_mq_handle_zone_resource(struct request *rq,
1904 struct list_head *zone_list)
1905{
1906 /*
1907 * If we end up here it is because we cannot dispatch a request to a
1908 * specific zone due to LLD level zone-write locking or other zone
1909 * related resource not being available. In this case, set the request
1910 * aside in zone_list for retrying it later.
1911 */
1912 list_add(&rq->queuelist, zone_list);
1913 __blk_mq_requeue_request(rq);
1914}
1915
75383524
ML
1916enum prep_dispatch {
1917 PREP_DISPATCH_OK,
1918 PREP_DISPATCH_NO_TAG,
1919 PREP_DISPATCH_NO_BUDGET,
1920};
1921
1922static enum prep_dispatch blk_mq_prep_dispatch_rq(struct request *rq,
1923 bool need_budget)
1924{
1925 struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
2a5a24aa 1926 int budget_token = -1;
75383524 1927
2a5a24aa
ML
1928 if (need_budget) {
1929 budget_token = blk_mq_get_dispatch_budget(rq->q);
1930 if (budget_token < 0) {
1931 blk_mq_put_driver_tag(rq);
1932 return PREP_DISPATCH_NO_BUDGET;
1933 }
1934 blk_mq_set_rq_budget_token(rq, budget_token);
75383524
ML
1935 }
1936
1937 if (!blk_mq_get_driver_tag(rq)) {
1938 /*
1939 * The initial allocation attempt failed, so we need to
1940 * rerun the hardware queue when a tag is freed. The
1941 * waitqueue takes care of that. If the queue is run
1942 * before we add this entry back on the dispatch list,
1943 * we'll re-run it below.
1944 */
1945 if (!blk_mq_mark_tag_wait(hctx, rq)) {
1fd40b5e
ML
1946 /*
1947 * All budgets not got from this function will be put
1948 * together during handling partial dispatch
1949 */
1950 if (need_budget)
2a5a24aa 1951 blk_mq_put_dispatch_budget(rq->q, budget_token);
75383524
ML
1952 return PREP_DISPATCH_NO_TAG;
1953 }
1954 }
1955
1956 return PREP_DISPATCH_OK;
1957}
1958
1fd40b5e
ML
1959/* release all allocated budgets before calling to blk_mq_dispatch_rq_list */
1960static void blk_mq_release_budgets(struct request_queue *q,
2a5a24aa 1961 struct list_head *list)
1fd40b5e 1962{
2a5a24aa 1963 struct request *rq;
1fd40b5e 1964
2a5a24aa
ML
1965 list_for_each_entry(rq, list, queuelist) {
1966 int budget_token = blk_mq_get_rq_budget_token(rq);
1fd40b5e 1967
2a5a24aa
ML
1968 if (budget_token >= 0)
1969 blk_mq_put_dispatch_budget(q, budget_token);
1970 }
1fd40b5e
ML
1971}
1972
34c9f547
KS
1973/*
1974 * blk_mq_commit_rqs will notify driver using bd->last that there is no
1975 * more requests. (See comment in struct blk_mq_ops for commit_rqs for
1976 * details)
1977 * Attention, we should explicitly call this in unusual cases:
1978 * 1) did not queue everything initially scheduled to queue
1979 * 2) the last attempt to queue a request failed
1980 */
1981static void blk_mq_commit_rqs(struct blk_mq_hw_ctx *hctx, int queued,
1982 bool from_schedule)
1983{
1984 if (hctx->queue->mq_ops->commit_rqs && queued) {
1985 trace_block_unplug(hctx->queue, queued, !from_schedule);
1986 hctx->queue->mq_ops->commit_rqs(hctx);
1987 }
1988}
1989
1f57f8d4
JA
1990/*
1991 * Returns true if we did some work AND can potentially do more.
1992 */
445874e8 1993bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list,
1fd40b5e 1994 unsigned int nr_budgets)
320ae51f 1995{
75383524 1996 enum prep_dispatch prep;
445874e8 1997 struct request_queue *q = hctx->queue;
f1ce99f7 1998 struct request *rq;
4ea58fe4 1999 int queued;
86ff7c2a 2000 blk_status_t ret = BLK_STS_OK;
0512a75b 2001 LIST_HEAD(zone_list);
9586e67b 2002 bool needs_resource = false;
320ae51f 2003
81380ca1
OS
2004 if (list_empty(list))
2005 return false;
2006
320ae51f
JA
2007 /*
2008 * Now process all the entries, sending them to the driver.
2009 */
4ea58fe4 2010 queued = 0;
81380ca1 2011 do {
74c45052 2012 struct blk_mq_queue_data bd;
320ae51f 2013
f04c3df3 2014 rq = list_first_entry(list, struct request, queuelist);
0bca799b 2015
445874e8 2016 WARN_ON_ONCE(hctx != rq->mq_hctx);
1fd40b5e 2017 prep = blk_mq_prep_dispatch_rq(rq, !nr_budgets);
75383524 2018 if (prep != PREP_DISPATCH_OK)
0bca799b 2019 break;
de148297 2020
320ae51f 2021 list_del_init(&rq->queuelist);
320ae51f 2022
74c45052 2023 bd.rq = rq;
f1ce99f7 2024 bd.last = list_empty(list);
74c45052 2025
1fd40b5e
ML
2026 /*
2027 * once the request is queued to lld, no need to cover the
2028 * budget any more
2029 */
2030 if (nr_budgets)
2031 nr_budgets--;
74c45052 2032 ret = q->mq_ops->queue_rq(hctx, &bd);
7bf13729
ML
2033 switch (ret) {
2034 case BLK_STS_OK:
2035 queued++;
320ae51f 2036 break;
7bf13729 2037 case BLK_STS_RESOURCE:
9586e67b
NA
2038 needs_resource = true;
2039 fallthrough;
7bf13729
ML
2040 case BLK_STS_DEV_RESOURCE:
2041 blk_mq_handle_dev_resource(rq, list);
2042 goto out;
2043 case BLK_STS_ZONE_RESOURCE:
0512a75b
KB
2044 /*
2045 * Move the request to zone_list and keep going through
2046 * the dispatch list to find more requests the drive can
2047 * accept.
2048 */
2049 blk_mq_handle_zone_resource(rq, &zone_list);
9586e67b 2050 needs_resource = true;
7bf13729
ML
2051 break;
2052 default:
e21ee5a6 2053 blk_mq_end_request(rq, ret);
320ae51f 2054 }
81380ca1 2055 } while (!list_empty(list));
7bf13729 2056out:
0512a75b
KB
2057 if (!list_empty(&zone_list))
2058 list_splice_tail_init(&zone_list, list);
2059
632bfb63 2060 /* If we didn't flush the entire list, we could have told the driver
2061 * there was more coming, but that turned out to be a lie.
2062 */
e4ef2e05
KS
2063 if (!list_empty(list) || ret != BLK_STS_OK)
2064 blk_mq_commit_rqs(hctx, queued, false);
2065
320ae51f
JA
2066 /*
2067 * Any items that need requeuing? Stuff them into hctx->dispatch,
2068 * that is where we will continue on next queue run.
2069 */
f04c3df3 2070 if (!list_empty(list)) {
86ff7c2a 2071 bool needs_restart;
75383524
ML
2072 /* For non-shared tags, the RESTART check will suffice */
2073 bool no_tag = prep == PREP_DISPATCH_NO_TAG &&
47df9ce9
KS
2074 ((hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) ||
2075 blk_mq_is_shared_tags(hctx->flags));
86ff7c2a 2076
2a5a24aa
ML
2077 if (nr_budgets)
2078 blk_mq_release_budgets(q, list);
86ff7c2a 2079
320ae51f 2080 spin_lock(&hctx->lock);
01e99aec 2081 list_splice_tail_init(list, &hctx->dispatch);
320ae51f 2082 spin_unlock(&hctx->lock);
f04c3df3 2083
d7d8535f
ML
2084 /*
2085 * Order adding requests to hctx->dispatch and checking
2086 * SCHED_RESTART flag. The pair of this smp_mb() is the one
2087 * in blk_mq_sched_restart(). Avoid restart code path to
2088 * miss the new added requests to hctx->dispatch, meantime
2089 * SCHED_RESTART is observed here.
2090 */
2091 smp_mb();
2092
9ba52e58 2093 /*
710c785f
BVA
2094 * If SCHED_RESTART was set by the caller of this function and
2095 * it is no longer set that means that it was cleared by another
2096 * thread and hence that a queue rerun is needed.
9ba52e58 2097 *
eb619fdb
JA
2098 * If 'no_tag' is set, that means that we failed getting
2099 * a driver tag with an I/O scheduler attached. If our dispatch
2100 * waitqueue is no longer active, ensure that we run the queue
2101 * AFTER adding our entries back to the list.
bd166ef1 2102 *
710c785f
BVA
2103 * If no I/O scheduler has been configured it is possible that
2104 * the hardware queue got stopped and restarted before requests
2105 * were pushed back onto the dispatch list. Rerun the queue to
2106 * avoid starvation. Notes:
2107 * - blk_mq_run_hw_queue() checks whether or not a queue has
2108 * been stopped before rerunning a queue.
2109 * - Some but not all block drivers stop a queue before
fc17b653 2110 * returning BLK_STS_RESOURCE. Two exceptions are scsi-mq
710c785f 2111 * and dm-rq.
86ff7c2a
ML
2112 *
2113 * If driver returns BLK_STS_RESOURCE and SCHED_RESTART
2114 * bit is set, run queue after a delay to avoid IO stalls
ab3cee37 2115 * that could otherwise occur if the queue is idle. We'll do
9586e67b
NA
2116 * similar if we couldn't get budget or couldn't lock a zone
2117 * and SCHED_RESTART is set.
bd166ef1 2118 */
86ff7c2a 2119 needs_restart = blk_mq_sched_needs_restart(hctx);
9586e67b
NA
2120 if (prep == PREP_DISPATCH_NO_BUDGET)
2121 needs_resource = true;
86ff7c2a 2122 if (!needs_restart ||
eb619fdb 2123 (no_tag && list_empty_careful(&hctx->dispatch_wait.entry)))
bd166ef1 2124 blk_mq_run_hw_queue(hctx, true);
6d5e8d21 2125 else if (needs_resource)
86ff7c2a 2126 blk_mq_delay_run_hw_queue(hctx, BLK_MQ_RESOURCE_DELAY);
1f57f8d4 2127
6e768717 2128 blk_mq_update_dispatch_busy(hctx, true);
1f57f8d4 2129 return false;
4ea58fe4 2130 }
f04c3df3 2131
4ea58fe4
KS
2132 blk_mq_update_dispatch_busy(hctx, false);
2133 return true;
f04c3df3
JA
2134}
2135
f82ddf19
ML
2136static inline int blk_mq_first_mapped_cpu(struct blk_mq_hw_ctx *hctx)
2137{
2138 int cpu = cpumask_first_and(hctx->cpumask, cpu_online_mask);
2139
2140 if (cpu >= nr_cpu_ids)
2141 cpu = cpumask_first(hctx->cpumask);
2142 return cpu;
2143}
2144
506e931f
JA
2145/*
2146 * It'd be great if the workqueue API had a way to pass
2147 * in a mask and had some smarts for more clever placement.
2148 * For now we just round-robin here, switching for every
2149 * BLK_MQ_CPU_WORK_BATCH queued items.
2150 */
2151static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx)
2152{
7bed4595 2153 bool tried = false;
476f8c98 2154 int next_cpu = hctx->next_cpu;
7bed4595 2155
b657d7e6
CH
2156 if (hctx->queue->nr_hw_queues == 1)
2157 return WORK_CPU_UNBOUND;
506e931f
JA
2158
2159 if (--hctx->next_cpu_batch <= 0) {
7bed4595 2160select_cpu:
476f8c98 2161 next_cpu = cpumask_next_and(next_cpu, hctx->cpumask,
20e4d813 2162 cpu_online_mask);
506e931f 2163 if (next_cpu >= nr_cpu_ids)
f82ddf19 2164 next_cpu = blk_mq_first_mapped_cpu(hctx);
506e931f
JA
2165 hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
2166 }
2167
7bed4595
ML
2168 /*
2169 * Do unbound schedule if we can't find a online CPU for this hctx,
2170 * and it should only happen in the path of handling CPU DEAD.
2171 */
476f8c98 2172 if (!cpu_online(next_cpu)) {
7bed4595
ML
2173 if (!tried) {
2174 tried = true;
2175 goto select_cpu;
2176 }
2177
2178 /*
2179 * Make sure to re-select CPU next time once after CPUs
2180 * in hctx->cpumask become online again.
2181 */
476f8c98 2182 hctx->next_cpu = next_cpu;
7bed4595
ML
2183 hctx->next_cpu_batch = 1;
2184 return WORK_CPU_UNBOUND;
2185 }
476f8c98
ML
2186
2187 hctx->next_cpu = next_cpu;
2188 return next_cpu;
506e931f
JA
2189}
2190
105663f7 2191/**
1aa8d875 2192 * blk_mq_delay_run_hw_queue - Run a hardware queue asynchronously.
105663f7 2193 * @hctx: Pointer to the hardware queue to run.
fa94ba8a 2194 * @msecs: Milliseconds of delay to wait before running the queue.
105663f7 2195 *
1aa8d875 2196 * Run a hardware queue asynchronously with a delay of @msecs.
105663f7 2197 */
1aa8d875 2198void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs)
320ae51f 2199{
5435c023 2200 if (unlikely(blk_mq_hctx_stopped(hctx)))
320ae51f 2201 return;
ae943d20
BVA
2202 kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work,
2203 msecs_to_jiffies(msecs));
7587a5ae 2204}
7587a5ae
BVA
2205EXPORT_SYMBOL(blk_mq_delay_run_hw_queue);
2206
105663f7
AA
2207/**
2208 * blk_mq_run_hw_queue - Start to run a hardware queue.
2209 * @hctx: Pointer to the hardware queue to run.
2210 * @async: If we want to run the queue asynchronously.
2211 *
2212 * Check if the request queue is not in a quiesced state and if there are
2213 * pending requests to be sent. If this is true, run the queue to send requests
2214 * to hardware.
2215 */
626fb735 2216void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
7587a5ae 2217{
24f5a90f
ML
2218 bool need_run;
2219
4d5bba5b
CH
2220 /*
2221 * We can't run the queue inline with interrupts disabled.
2222 */
2223 WARN_ON_ONCE(!async && in_interrupt());
2224
24f5a90f
ML
2225 /*
2226 * When queue is quiesced, we may be switching io scheduler, or
2227 * updating nr_hw_queues, or other things, and we can't run queue
2228 * any more, even __blk_mq_hctx_has_pending() can't be called safely.
2229 *
2230 * And queue will be rerun in blk_mq_unquiesce_queue() if it is
2231 * quiesced.
2232 */
41adf531 2233 __blk_mq_run_dispatch_ops(hctx->queue, false,
2a904d00
ML
2234 need_run = !blk_queue_quiesced(hctx->queue) &&
2235 blk_mq_hctx_has_pending(hctx));
24f5a90f 2236
1aa8d875
CH
2237 if (!need_run)
2238 return;
2239
2240 if (async || (hctx->flags & BLK_MQ_F_BLOCKING) ||
2241 !cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask)) {
2242 blk_mq_delay_run_hw_queue(hctx, 0);
2243 return;
2244 }
2245
4d5bba5b
CH
2246 blk_mq_run_dispatch_ops(hctx->queue,
2247 blk_mq_sched_dispatch_requests(hctx));
320ae51f 2248}
5b727272 2249EXPORT_SYMBOL(blk_mq_run_hw_queue);
320ae51f 2250
b6e68ee8
JK
2251/*
2252 * Return prefered queue to dispatch from (if any) for non-mq aware IO
2253 * scheduler.
2254 */
2255static struct blk_mq_hw_ctx *blk_mq_get_sq_hctx(struct request_queue *q)
2256{
5d05426e 2257 struct blk_mq_ctx *ctx = blk_mq_get_ctx(q);
b6e68ee8
JK
2258 /*
2259 * If the IO scheduler does not respect hardware queues when
2260 * dispatching, we just don't bother with multiple HW queues and
2261 * dispatch from hctx for the current CPU since running multiple queues
2262 * just causes lock contention inside the scheduler and pointless cache
2263 * bouncing.
2264 */
51ab80f0 2265 struct blk_mq_hw_ctx *hctx = ctx->hctxs[HCTX_TYPE_DEFAULT];
5d05426e 2266
b6e68ee8
JK
2267 if (!blk_mq_hctx_stopped(hctx))
2268 return hctx;
2269 return NULL;
2270}
2271
105663f7 2272/**
24f7bb88 2273 * blk_mq_run_hw_queues - Run all hardware queues in a request queue.
105663f7
AA
2274 * @q: Pointer to the request queue to run.
2275 * @async: If we want to run the queue asynchronously.
2276 */
b94ec296 2277void blk_mq_run_hw_queues(struct request_queue *q, bool async)
320ae51f 2278{
b6e68ee8 2279 struct blk_mq_hw_ctx *hctx, *sq_hctx;
4f481208 2280 unsigned long i;
320ae51f 2281
b6e68ee8 2282 sq_hctx = NULL;
4d337ceb 2283 if (blk_queue_sq_sched(q))
b6e68ee8 2284 sq_hctx = blk_mq_get_sq_hctx(q);
320ae51f 2285 queue_for_each_hw_ctx(q, hctx, i) {
79f720a7 2286 if (blk_mq_hctx_stopped(hctx))
320ae51f 2287 continue;
b6e68ee8
JK
2288 /*
2289 * Dispatch from this hctx either if there's no hctx preferred
2290 * by IO scheduler or if it has requests that bypass the
2291 * scheduler.
2292 */
2293 if (!sq_hctx || sq_hctx == hctx ||
2294 !list_empty_careful(&hctx->dispatch))
2295 blk_mq_run_hw_queue(hctx, async);
320ae51f
JA
2296 }
2297}
b94ec296 2298EXPORT_SYMBOL(blk_mq_run_hw_queues);
320ae51f 2299
b9151e7b
DA
2300/**
2301 * blk_mq_delay_run_hw_queues - Run all hardware queues asynchronously.
2302 * @q: Pointer to the request queue to run.
fa94ba8a 2303 * @msecs: Milliseconds of delay to wait before running the queues.
b9151e7b
DA
2304 */
2305void blk_mq_delay_run_hw_queues(struct request_queue *q, unsigned long msecs)
2306{
b6e68ee8 2307 struct blk_mq_hw_ctx *hctx, *sq_hctx;
4f481208 2308 unsigned long i;
b9151e7b 2309
b6e68ee8 2310 sq_hctx = NULL;
4d337ceb 2311 if (blk_queue_sq_sched(q))
b6e68ee8 2312 sq_hctx = blk_mq_get_sq_hctx(q);
b9151e7b
DA
2313 queue_for_each_hw_ctx(q, hctx, i) {
2314 if (blk_mq_hctx_stopped(hctx))
2315 continue;
8f5fea65
DJ
2316 /*
2317 * If there is already a run_work pending, leave the
2318 * pending delay untouched. Otherwise, a hctx can stall
2319 * if another hctx is re-delaying the other's work
2320 * before the work executes.
2321 */
2322 if (delayed_work_pending(&hctx->run_work))
2323 continue;
b6e68ee8
JK
2324 /*
2325 * Dispatch from this hctx either if there's no hctx preferred
2326 * by IO scheduler or if it has requests that bypass the
2327 * scheduler.
2328 */
2329 if (!sq_hctx || sq_hctx == hctx ||
2330 !list_empty_careful(&hctx->dispatch))
2331 blk_mq_delay_run_hw_queue(hctx, msecs);
b9151e7b
DA
2332 }
2333}
2334EXPORT_SYMBOL(blk_mq_delay_run_hw_queues);
2335
39a70c76
ML
2336/*
2337 * This function is often used for pausing .queue_rq() by driver when
2338 * there isn't enough resource or some conditions aren't satisfied, and
4d606219 2339 * BLK_STS_RESOURCE is usually returned.
39a70c76
ML
2340 *
2341 * We do not guarantee that dispatch can be drained or blocked
2342 * after blk_mq_stop_hw_queue() returns. Please use
2343 * blk_mq_quiesce_queue() for that requirement.
2344 */
2719aa21
JA
2345void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx)
2346{
641a9ed6 2347 cancel_delayed_work(&hctx->run_work);
280d45f6 2348
641a9ed6 2349 set_bit(BLK_MQ_S_STOPPED, &hctx->state);
2719aa21 2350}
641a9ed6 2351EXPORT_SYMBOL(blk_mq_stop_hw_queue);
2719aa21 2352
39a70c76
ML
2353/*
2354 * This function is often used for pausing .queue_rq() by driver when
2355 * there isn't enough resource or some conditions aren't satisfied, and
4d606219 2356 * BLK_STS_RESOURCE is usually returned.
39a70c76
ML
2357 *
2358 * We do not guarantee that dispatch can be drained or blocked
2359 * after blk_mq_stop_hw_queues() returns. Please use
2360 * blk_mq_quiesce_queue() for that requirement.
2361 */
2719aa21
JA
2362void blk_mq_stop_hw_queues(struct request_queue *q)
2363{
641a9ed6 2364 struct blk_mq_hw_ctx *hctx;
4f481208 2365 unsigned long i;
641a9ed6
ML
2366
2367 queue_for_each_hw_ctx(q, hctx, i)
2368 blk_mq_stop_hw_queue(hctx);
280d45f6
CH
2369}
2370EXPORT_SYMBOL(blk_mq_stop_hw_queues);
2371
320ae51f
JA
2372void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx)
2373{
2374 clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
e4043dcf 2375
0ffbce80 2376 blk_mq_run_hw_queue(hctx, false);
320ae51f
JA
2377}
2378EXPORT_SYMBOL(blk_mq_start_hw_queue);
2379
2f268556
CH
2380void blk_mq_start_hw_queues(struct request_queue *q)
2381{
2382 struct blk_mq_hw_ctx *hctx;
4f481208 2383 unsigned long i;
2f268556
CH
2384
2385 queue_for_each_hw_ctx(q, hctx, i)
2386 blk_mq_start_hw_queue(hctx);
2387}
2388EXPORT_SYMBOL(blk_mq_start_hw_queues);
2389
ae911c5e
JA
2390void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
2391{
2392 if (!blk_mq_hctx_stopped(hctx))
2393 return;
2394
2395 clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
2396 blk_mq_run_hw_queue(hctx, async);
2397}
2398EXPORT_SYMBOL_GPL(blk_mq_start_stopped_hw_queue);
2399
1b4a3258 2400void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async)
320ae51f
JA
2401{
2402 struct blk_mq_hw_ctx *hctx;
4f481208 2403 unsigned long i;
320ae51f 2404
ae911c5e
JA
2405 queue_for_each_hw_ctx(q, hctx, i)
2406 blk_mq_start_stopped_hw_queue(hctx, async);
320ae51f
JA
2407}
2408EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues);
2409
70f4db63 2410static void blk_mq_run_work_fn(struct work_struct *work)
320ae51f 2411{
c20a1a2c
CH
2412 struct blk_mq_hw_ctx *hctx =
2413 container_of(work, struct blk_mq_hw_ctx, run_work.work);
7b607814 2414
4d5bba5b
CH
2415 blk_mq_run_dispatch_ops(hctx->queue,
2416 blk_mq_sched_dispatch_requests(hctx));
320ae51f
JA
2417}
2418
105663f7
AA
2419/**
2420 * blk_mq_request_bypass_insert - Insert a request at dispatch list.
2421 * @rq: Pointer to request to be inserted.
2b597613 2422 * @flags: BLK_MQ_INSERT_*
105663f7 2423 *
157f377b
JA
2424 * Should only be used carefully, when the caller knows we want to
2425 * bypass a potential IO scheduler on the target device.
2426 */
360f2648 2427static void blk_mq_request_bypass_insert(struct request *rq, blk_insert_t flags)
157f377b 2428{
ea4f995e 2429 struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
157f377b
JA
2430
2431 spin_lock(&hctx->lock);
2b597613 2432 if (flags & BLK_MQ_INSERT_AT_HEAD)
01e99aec
ML
2433 list_add(&rq->queuelist, &hctx->dispatch);
2434 else
2435 list_add_tail(&rq->queuelist, &hctx->dispatch);
157f377b 2436 spin_unlock(&hctx->lock);
157f377b
JA
2437}
2438
05a93117
CH
2439static void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx,
2440 struct blk_mq_ctx *ctx, struct list_head *list,
2441 bool run_queue_async)
320ae51f 2442{
3f0cedc7 2443 struct request *rq;
c16d6b5a 2444 enum hctx_type type = hctx->type;
3f0cedc7 2445
94aa228c
CH
2446 /*
2447 * Try to issue requests directly if the hw queue isn't busy to save an
2448 * extra enqueue & dequeue to the sw queue.
2449 */
2450 if (!hctx->dispatch_busy && !run_queue_async) {
2451 blk_mq_run_dispatch_ops(hctx->queue,
2452 blk_mq_try_issue_list_directly(hctx, list));
2453 if (list_empty(list))
2454 goto out;
2455 }
2456
320ae51f
JA
2457 /*
2458 * preemption doesn't flush plug list, so it's possible ctx->cpu is
2459 * offline now
2460 */
3f0cedc7 2461 list_for_each_entry(rq, list, queuelist) {
e57690fe 2462 BUG_ON(rq->mq_ctx != ctx);
a54895fa 2463 trace_block_rq_insert(rq);
320ae51f 2464 }
3f0cedc7
ML
2465
2466 spin_lock(&ctx->lock);
c16d6b5a 2467 list_splice_tail_init(list, &ctx->rq_lists[type]);
cfd0c552 2468 blk_mq_hctx_mark_pending(hctx, ctx);
320ae51f 2469 spin_unlock(&ctx->lock);
94aa228c
CH
2470out:
2471 blk_mq_run_hw_queue(hctx, run_queue_async);
320ae51f
JA
2472}
2473
710fa378 2474static void blk_mq_insert_request(struct request *rq, blk_insert_t flags)
2bd215df
CH
2475{
2476 struct request_queue *q = rq->q;
2bd215df
CH
2477 struct blk_mq_ctx *ctx = rq->mq_ctx;
2478 struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
2479
53548d2a
CH
2480 if (blk_rq_is_passthrough(rq)) {
2481 /*
2482 * Passthrough request have to be added to hctx->dispatch
2483 * directly. The device may be in a situation where it can't
2484 * handle FS request, and always returns BLK_STS_RESOURCE for
2485 * them, which gets them added to hctx->dispatch.
2486 *
2487 * If a passthrough request is required to unblock the queues,
2488 * and it is added to the scheduler queue, there is no chance to
2489 * dispatch it given we prioritize requests in hctx->dispatch.
2490 */
2b597613 2491 blk_mq_request_bypass_insert(rq, flags);
be4c4278 2492 } else if (req_op(rq) == REQ_OP_FLUSH) {
2bd215df
CH
2493 /*
2494 * Firstly normal IO request is inserted to scheduler queue or
2495 * sw queue, meantime we add flush request to dispatch queue(
2496 * hctx->dispatch) directly and there is at most one in-flight
2497 * flush request for each hw queue, so it doesn't matter to add
2498 * flush request to tail or front of the dispatch queue.
2499 *
2500 * Secondly in case of NCQ, flush request belongs to non-NCQ
2501 * command, and queueing it will fail when there is any
2502 * in-flight normal IO request(NCQ command). When adding flush
2503 * rq to the front of hctx->dispatch, it is easier to introduce
2504 * extra time to flush rq's latency because of S_SCHED_RESTART
2505 * compared with adding to the tail of dispatch queue, then
2506 * chance of flush merge is increased, and less flush requests
2507 * will be issued to controller. It is observed that ~10% time
2508 * is saved in blktests block/004 on disk attached to AHCI/NCQ
2509 * drive when adding flush rq to the front of hctx->dispatch.
2510 *
2511 * Simply queue flush rq to the front of hctx->dispatch so that
2512 * intensive flush workloads can benefit in case of NCQ HW.
2513 */
2b597613 2514 blk_mq_request_bypass_insert(rq, BLK_MQ_INSERT_AT_HEAD);
53548d2a 2515 } else if (q->elevator) {
2bd215df
CH
2516 LIST_HEAD(list);
2517
53548d2a
CH
2518 WARN_ON_ONCE(rq->tag != BLK_MQ_NO_TAG);
2519
2bd215df 2520 list_add(&rq->queuelist, &list);
93fffe16 2521 q->elevator->type->ops.insert_requests(hctx, &list, flags);
2bd215df 2522 } else {
4ec5c055
CH
2523 trace_block_rq_insert(rq);
2524
2bd215df 2525 spin_lock(&ctx->lock);
710fa378 2526 if (flags & BLK_MQ_INSERT_AT_HEAD)
4ec5c055
CH
2527 list_add(&rq->queuelist, &ctx->rq_lists[hctx->type]);
2528 else
2529 list_add_tail(&rq->queuelist,
2530 &ctx->rq_lists[hctx->type]);
a88db1e0 2531 blk_mq_hctx_mark_pending(hctx, ctx);
2bd215df
CH
2532 spin_unlock(&ctx->lock);
2533 }
320ae51f
JA
2534}
2535
14ccb66b
CH
2536static void blk_mq_bio_to_request(struct request *rq, struct bio *bio,
2537 unsigned int nr_segs)
320ae51f 2538{
93f221ae
EB
2539 int err;
2540
f924cdde
CH
2541 if (bio->bi_opf & REQ_RAHEAD)
2542 rq->cmd_flags |= REQ_FAILFAST_MASK;
2543
2544 rq->__sector = bio->bi_iter.bi_sector;
14ccb66b 2545 blk_rq_bio_prep(rq, bio, nr_segs);
93f221ae
EB
2546
2547 /* This can't fail, since GFP_NOIO includes __GFP_DIRECT_RECLAIM. */
2548 err = blk_crypto_rq_bio_prep(rq, bio, GFP_NOIO);
2549 WARN_ON_ONCE(err);
4b570521 2550
b5af37ab 2551 blk_account_io_start(rq);
320ae51f
JA
2552}
2553
0f95549c 2554static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx,
3e08773c 2555 struct request *rq, bool last)
f984df1f 2556{
f984df1f 2557 struct request_queue *q = rq->q;
f984df1f
SL
2558 struct blk_mq_queue_data bd = {
2559 .rq = rq,
be94f058 2560 .last = last,
f984df1f 2561 };
f06345ad 2562 blk_status_t ret;
0f95549c 2563
0f95549c
MS
2564 /*
2565 * For OK queue, we are done. For error, caller may kill it.
2566 * Any other error (busy), just add it to our list as we
2567 * previously would have done.
2568 */
2569 ret = q->mq_ops->queue_rq(hctx, &bd);
2570 switch (ret) {
2571 case BLK_STS_OK:
6ce3dd6e 2572 blk_mq_update_dispatch_busy(hctx, false);
0f95549c
MS
2573 break;
2574 case BLK_STS_RESOURCE:
86ff7c2a 2575 case BLK_STS_DEV_RESOURCE:
6ce3dd6e 2576 blk_mq_update_dispatch_busy(hctx, true);
0f95549c
MS
2577 __blk_mq_requeue_request(rq);
2578 break;
2579 default:
6ce3dd6e 2580 blk_mq_update_dispatch_busy(hctx, false);
0f95549c
MS
2581 break;
2582 }
2583
2584 return ret;
2585}
2586
2b71b877 2587static bool blk_mq_get_budget_and_tag(struct request *rq)
0f95549c 2588{
2a5a24aa 2589 int budget_token;
d964f04a 2590
2b71b877 2591 budget_token = blk_mq_get_dispatch_budget(rq->q);
2a5a24aa 2592 if (budget_token < 0)
2b71b877 2593 return false;
2a5a24aa 2594 blk_mq_set_rq_budget_token(rq, budget_token);
8ab6bb9e 2595 if (!blk_mq_get_driver_tag(rq)) {
2b71b877
CH
2596 blk_mq_put_dispatch_budget(rq->q, budget_token);
2597 return false;
88022d72 2598 }
2b71b877 2599 return true;
fd9c40f6
BVA
2600}
2601
105663f7
AA
2602/**
2603 * blk_mq_try_issue_directly - Try to send a request directly to device driver.
2604 * @hctx: Pointer of the associated hardware queue.
2605 * @rq: Pointer to request to be sent.
105663f7
AA
2606 *
2607 * If the device has enough resources to accept a new request now, send the
2608 * request directly to device driver. Else, insert at hctx->dispatch queue, so
2609 * we can try send it another time in the future. Requests inserted at this
2610 * queue have higher priority.
2611 */
fd9c40f6 2612static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
3e08773c 2613 struct request *rq)
fd9c40f6 2614{
e1f44ac0
CH
2615 blk_status_t ret;
2616
2617 if (blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(rq->q)) {
710fa378 2618 blk_mq_insert_request(rq, 0);
e1f44ac0
CH
2619 return;
2620 }
2621
dd6216bb 2622 if ((rq->rq_flags & RQF_USE_SCHED) || !blk_mq_get_budget_and_tag(rq)) {
710fa378 2623 blk_mq_insert_request(rq, 0);
f0dbe6e8 2624 blk_mq_run_hw_queue(hctx, false);
e1f44ac0
CH
2625 return;
2626 }
fd9c40f6 2627
e1f44ac0
CH
2628 ret = __blk_mq_issue_directly(hctx, rq, true);
2629 switch (ret) {
2630 case BLK_STS_OK:
2631 break;
2632 case BLK_STS_RESOURCE:
2633 case BLK_STS_DEV_RESOURCE:
2b597613 2634 blk_mq_request_bypass_insert(rq, 0);
2394395c 2635 blk_mq_run_hw_queue(hctx, false);
e1f44ac0
CH
2636 break;
2637 default:
fd9c40f6 2638 blk_mq_end_request(rq, ret);
e1f44ac0
CH
2639 break;
2640 }
fd9c40f6
BVA
2641}
2642
06c8c691 2643static blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last)
fd9c40f6 2644{
e1f44ac0
CH
2645 struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
2646
2647 if (blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(rq->q)) {
710fa378 2648 blk_mq_insert_request(rq, 0);
e1f44ac0
CH
2649 return BLK_STS_OK;
2650 }
2651
2652 if (!blk_mq_get_budget_and_tag(rq))
2653 return BLK_STS_RESOURCE;
2654 return __blk_mq_issue_directly(hctx, rq, last);
5eb6126e
CH
2655}
2656
3e368fb0 2657static void blk_mq_plug_issue_direct(struct blk_plug *plug)
b84c5b50
CH
2658{
2659 struct blk_mq_hw_ctx *hctx = NULL;
2660 struct request *rq;
2661 int queued = 0;
0d617a83 2662 blk_status_t ret = BLK_STS_OK;
b84c5b50
CH
2663
2664 while ((rq = rq_list_pop(&plug->mq_list))) {
2665 bool last = rq_list_empty(plug->mq_list);
b84c5b50
CH
2666
2667 if (hctx != rq->mq_hctx) {
34c9f547
KS
2668 if (hctx) {
2669 blk_mq_commit_rqs(hctx, queued, false);
2670 queued = 0;
2671 }
b84c5b50
CH
2672 hctx = rq->mq_hctx;
2673 }
2674
2675 ret = blk_mq_request_issue_directly(rq, last);
2676 switch (ret) {
2677 case BLK_STS_OK:
2678 queued++;
2679 break;
2680 case BLK_STS_RESOURCE:
2681 case BLK_STS_DEV_RESOURCE:
2b597613 2682 blk_mq_request_bypass_insert(rq, 0);
2394395c 2683 blk_mq_run_hw_queue(hctx, false);
0d617a83 2684 goto out;
b84c5b50
CH
2685 default:
2686 blk_mq_end_request(rq, ret);
b84c5b50
CH
2687 break;
2688 }
2689 }
2690
0d617a83
KS
2691out:
2692 if (ret != BLK_STS_OK)
34c9f547 2693 blk_mq_commit_rqs(hctx, queued, false);
b84c5b50
CH
2694}
2695
518579a9
KB
2696static void __blk_mq_flush_plug_list(struct request_queue *q,
2697 struct blk_plug *plug)
2698{
2699 if (blk_queue_quiesced(q))
2700 return;
2701 q->mq_ops->queue_rqs(&plug->mq_list);
2702}
2703
26fed4ac
JA
2704static void blk_mq_dispatch_plug_list(struct blk_plug *plug, bool from_sched)
2705{
2706 struct blk_mq_hw_ctx *this_hctx = NULL;
2707 struct blk_mq_ctx *this_ctx = NULL;
2708 struct request *requeue_list = NULL;
34e0a279 2709 struct request **requeue_lastp = &requeue_list;
26fed4ac 2710 unsigned int depth = 0;
d97217e7 2711 bool is_passthrough = false;
26fed4ac
JA
2712 LIST_HEAD(list);
2713
2714 do {
2715 struct request *rq = rq_list_pop(&plug->mq_list);
2716
2717 if (!this_hctx) {
2718 this_hctx = rq->mq_hctx;
2719 this_ctx = rq->mq_ctx;
d97217e7
ML
2720 is_passthrough = blk_rq_is_passthrough(rq);
2721 } else if (this_hctx != rq->mq_hctx || this_ctx != rq->mq_ctx ||
2722 is_passthrough != blk_rq_is_passthrough(rq)) {
34e0a279 2723 rq_list_add_tail(&requeue_lastp, rq);
26fed4ac
JA
2724 continue;
2725 }
34e0a279 2726 list_add(&rq->queuelist, &list);
26fed4ac
JA
2727 depth++;
2728 } while (!rq_list_empty(plug->mq_list));
2729
2730 plug->mq_list = requeue_list;
2731 trace_block_unplug(this_hctx->queue, depth, !from_sched);
05a93117
CH
2732
2733 percpu_ref_get(&this_hctx->queue->q_usage_counter);
d97217e7 2734 /* passthrough requests should never be issued to the I/O scheduler */
2293cae7
ML
2735 if (is_passthrough) {
2736 spin_lock(&this_hctx->lock);
2737 list_splice_tail_init(&list, &this_hctx->dispatch);
2738 spin_unlock(&this_hctx->lock);
2739 blk_mq_run_hw_queue(this_hctx, from_sched);
2740 } else if (this_hctx->queue->elevator) {
05a93117 2741 this_hctx->queue->elevator->type->ops.insert_requests(this_hctx,
93fffe16 2742 &list, 0);
05a93117
CH
2743 blk_mq_run_hw_queue(this_hctx, from_sched);
2744 } else {
2745 blk_mq_insert_requests(this_hctx, this_ctx, &list, from_sched);
2746 }
2747 percpu_ref_put(&this_hctx->queue->q_usage_counter);
26fed4ac
JA
2748}
2749
b84c5b50
CH
2750void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
2751{
3c67d44d 2752 struct request *rq;
b84c5b50
CH
2753
2754 if (rq_list_empty(plug->mq_list))
2755 return;
2756 plug->rq_count = 0;
2757
2758 if (!plug->multiple_queues && !plug->has_elevator && !from_schedule) {
3c67d44d
JA
2759 struct request_queue *q;
2760
2761 rq = rq_list_peek(&plug->mq_list);
2762 q = rq->q;
2763
2764 /*
2765 * Peek first request and see if we have a ->queue_rqs() hook.
2766 * If we do, we can dispatch the whole plug list in one go. We
2767 * already know at this point that all requests belong to the
2768 * same queue, caller must ensure that's the case.
2769 *
2770 * Since we pass off the full list to the driver at this point,
2771 * we do not increment the active request count for the queue.
2772 * Bypass shared tags for now because of that.
2773 */
2774 if (q->mq_ops->queue_rqs &&
2775 !(rq->mq_hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) {
2776 blk_mq_run_dispatch_ops(q,
518579a9 2777 __blk_mq_flush_plug_list(q, plug));
3c67d44d
JA
2778 if (rq_list_empty(plug->mq_list))
2779 return;
2780 }
73f3760e
ML
2781
2782 blk_mq_run_dispatch_ops(q,
3e368fb0 2783 blk_mq_plug_issue_direct(plug));
b84c5b50
CH
2784 if (rq_list_empty(plug->mq_list))
2785 return;
2786 }
2787
b84c5b50 2788 do {
26fed4ac 2789 blk_mq_dispatch_plug_list(plug, from_schedule);
b84c5b50 2790 } while (!rq_list_empty(plug->mq_list));
b84c5b50
CH
2791}
2792
94aa228c 2793static void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
6ce3dd6e
ML
2794 struct list_head *list)
2795{
536167d4 2796 int queued = 0;
984ce0a7 2797 blk_status_t ret = BLK_STS_OK;
536167d4 2798
6ce3dd6e 2799 while (!list_empty(list)) {
6ce3dd6e
ML
2800 struct request *rq = list_first_entry(list, struct request,
2801 queuelist);
2802
2803 list_del_init(&rq->queuelist);
fd9c40f6 2804 ret = blk_mq_request_issue_directly(rq, list_empty(list));
27e8b2bb
KS
2805 switch (ret) {
2806 case BLK_STS_OK:
536167d4 2807 queued++;
27e8b2bb
KS
2808 break;
2809 case BLK_STS_RESOURCE:
2810 case BLK_STS_DEV_RESOURCE:
2b597613 2811 blk_mq_request_bypass_insert(rq, 0);
2394395c
CH
2812 if (list_empty(list))
2813 blk_mq_run_hw_queue(hctx, false);
27e8b2bb
KS
2814 goto out;
2815 default:
2816 blk_mq_end_request(rq, ret);
2817 break;
2818 }
6ce3dd6e 2819 }
d666ba98 2820
27e8b2bb 2821out:
984ce0a7
KS
2822 if (ret != BLK_STS_OK)
2823 blk_mq_commit_rqs(hctx, queued, false);
6ce3dd6e
ML
2824}
2825
b131f201 2826static bool blk_mq_attempt_bio_merge(struct request_queue *q,
0c5bcc92 2827 struct bio *bio, unsigned int nr_segs)
900e0807
JA
2828{
2829 if (!blk_queue_nomerges(q) && bio_mergeable(bio)) {
0c5bcc92 2830 if (blk_attempt_plug_merge(q, bio, nr_segs))
900e0807
JA
2831 return true;
2832 if (blk_mq_sched_bio_merge(q, bio, nr_segs))
2833 return true;
2834 }
2835 return false;
2836}
2837
71539717
JA
2838static struct request *blk_mq_get_new_requests(struct request_queue *q,
2839 struct blk_plug *plug,
0a5aa8d1
SK
2840 struct bio *bio,
2841 unsigned int nsegs)
71539717
JA
2842{
2843 struct blk_mq_alloc_data data = {
2844 .q = q,
2845 .nr_tags = 1,
9d497e29 2846 .cmd_flags = bio->bi_opf,
71539717
JA
2847 };
2848 struct request *rq;
2849
5b13bc8a 2850 if (unlikely(bio_queue_enter(bio)))
b637108a 2851 return NULL;
900e0807 2852
0a5aa8d1
SK
2853 if (blk_mq_attempt_bio_merge(q, bio, nsegs))
2854 goto queue_exit;
2855
2856 rq_qos_throttle(q, bio);
2857
71539717
JA
2858 if (plug) {
2859 data.nr_tags = plug->nr_ios;
2860 plug->nr_ios = 1;
2861 data.cached_rq = &plug->cached_rq;
2862 }
2863
2864 rq = __blk_mq_alloc_requests(&data);
373b5416
JA
2865 if (rq)
2866 return rq;
71539717
JA
2867 rq_qos_cleanup(q, bio);
2868 if (bio->bi_opf & REQ_NOWAIT)
2869 bio_wouldblock_error(bio);
0a5aa8d1 2870queue_exit:
5b13bc8a 2871 blk_queue_exit(q);
71539717
JA
2872 return NULL;
2873}
2874
5b13bc8a 2875static inline struct request *blk_mq_get_cached_request(struct request_queue *q,
0a5aa8d1 2876 struct blk_plug *plug, struct bio **bio, unsigned int nsegs)
71539717 2877{
b637108a 2878 struct request *rq;
77465647 2879 enum hctx_type type, hctx_type;
b637108a 2880
5b13bc8a
CH
2881 if (!plug)
2882 return NULL;
81ea1222
ML
2883 rq = rq_list_peek(&plug->cached_rq);
2884 if (!rq || rq->q != q)
2885 return NULL;
71539717 2886
0a5aa8d1
SK
2887 if (blk_mq_attempt_bio_merge(q, *bio, nsegs)) {
2888 *bio = NULL;
2889 return NULL;
2890 }
2891
77465647
PB
2892 type = blk_mq_get_hctx_type((*bio)->bi_opf);
2893 hctx_type = rq->mq_hctx->type;
2894 if (type != hctx_type &&
2895 !(type == HCTX_TYPE_READ && hctx_type == HCTX_TYPE_DEFAULT))
5b13bc8a 2896 return NULL;
0a5aa8d1 2897 if (op_is_flush(rq->cmd_flags) != op_is_flush((*bio)->bi_opf))
5b13bc8a
CH
2898 return NULL;
2899
2645672f
JA
2900 /*
2901 * If any qos ->throttle() end up blocking, we will have flushed the
2902 * plug and hence killed the cached_rq list as well. Pop this entry
2903 * before we throttle.
2904 */
5b13bc8a 2905 plug->cached_rq = rq_list_next(rq);
2645672f
JA
2906 rq_qos_throttle(q, *bio);
2907
2908 rq->cmd_flags = (*bio)->bi_opf;
5b13bc8a 2909 INIT_LIST_HEAD(&rq->queuelist);
5b13bc8a 2910 return rq;
71539717
JA
2911}
2912
82b74cac
JK
2913static void bio_set_ioprio(struct bio *bio)
2914{
a78418e6
JK
2915 /* Nobody set ioprio so far? Initialize it based on task's nice value */
2916 if (IOPRIO_PRIO_CLASS(bio->bi_ioprio) == IOPRIO_CLASS_NONE)
2917 bio->bi_ioprio = get_current_ioprio();
82b74cac
JK
2918 blkcg_set_ioprio(bio);
2919}
2920
105663f7 2921/**
c62b37d9 2922 * blk_mq_submit_bio - Create and send a request to block device.
105663f7
AA
2923 * @bio: Bio pointer.
2924 *
2925 * Builds up a request structure from @q and @bio and send to the device. The
2926 * request may not be queued directly to hardware if:
2927 * * This request can be merged with another one
2928 * * We want to place request at plug queue for possible future merging
2929 * * There is an IO scheduler active at this queue
2930 *
2931 * It will not queue the request if there is an error with the bio, or at the
2932 * request creation.
105663f7 2933 */
3e08773c 2934void blk_mq_submit_bio(struct bio *bio)
07068d5b 2935{
ed6cddef 2936 struct request_queue *q = bdev_get_queue(bio->bi_bdev);
6deacb3b 2937 struct blk_plug *plug = blk_mq_plug(bio);
ef295ecf 2938 const int is_sync = op_is_sync(bio->bi_opf);
f0dbe6e8 2939 struct blk_mq_hw_ctx *hctx;
07068d5b 2940 struct request *rq;
abd45c15 2941 unsigned int nr_segs = 1;
a892c8d5 2942 blk_status_t ret;
07068d5b 2943
51d798cd 2944 bio = blk_queue_bounce(bio, q);
613b1488 2945 if (bio_may_exceed_limits(bio, &q->limits)) {
c55ddd90 2946 bio = __bio_split_to_limits(bio, &q->limits, &nr_segs);
613b1488
JA
2947 if (!bio)
2948 return;
2949 }
f36ea50c 2950
e23947bd 2951 if (!bio_integrity_prep(bio))
900e0807 2952 return;
87760e5e 2953
9c6227e0
JK
2954 bio_set_ioprio(bio);
2955
0a5aa8d1 2956 rq = blk_mq_get_cached_request(q, plug, &bio, nr_segs);
5b13bc8a 2957 if (!rq) {
0a5aa8d1
SK
2958 if (!bio)
2959 return;
2960 rq = blk_mq_get_new_requests(q, plug, bio, nr_segs);
5b13bc8a
CH
2961 if (unlikely(!rq))
2962 return;
2963 }
87760e5e 2964
e8a676d6 2965 trace_block_getrq(bio);
d6f1dda2 2966
c1c80384 2967 rq_qos_track(q, rq, bio);
07068d5b 2968
970d168d
BVA
2969 blk_mq_bio_to_request(rq, bio, nr_segs);
2970
9cd1e566 2971 ret = blk_crypto_rq_get_keyslot(rq);
a892c8d5
ST
2972 if (ret != BLK_STS_OK) {
2973 bio->bi_status = ret;
2974 bio_endio(bio);
2975 blk_mq_free_request(rq);
3e08773c 2976 return;
a892c8d5
ST
2977 }
2978
360f2648 2979 if (op_is_flush(bio->bi_opf) && blk_insert_flush(rq))
d92ca9d8
CH
2980 return;
2981
f0dbe6e8 2982 if (plug) {
ce5b009c 2983 blk_add_rq_to_plug(plug, rq);
f0dbe6e8
CH
2984 return;
2985 }
2986
2987 hctx = rq->mq_hctx;
dd6216bb 2988 if ((rq->rq_flags & RQF_USE_SCHED) ||
f0dbe6e8 2989 (hctx->dispatch_busy && (q->nr_hw_queues == 1 || !is_sync))) {
710fa378 2990 blk_mq_insert_request(rq, 0);
f0dbe6e8
CH
2991 blk_mq_run_hw_queue(hctx, true);
2992 } else {
2993 blk_mq_run_dispatch_ops(q, blk_mq_try_issue_directly(hctx, rq));
2994 }
320ae51f
JA
2995}
2996
248c7933 2997#ifdef CONFIG_BLK_MQ_STACKING
06c8c691 2998/**
a5efda3c 2999 * blk_insert_cloned_request - Helper for stacking drivers to submit a request
a5efda3c 3000 * @rq: the request being queued
06c8c691 3001 */
28db4711 3002blk_status_t blk_insert_cloned_request(struct request *rq)
06c8c691 3003{
28db4711 3004 struct request_queue *q = rq->q;
06c8c691 3005 unsigned int max_sectors = blk_queue_get_max_sectors(q, req_op(rq));
49d24398 3006 unsigned int max_segments = blk_rq_get_max_segments(rq);
a5efda3c 3007 blk_status_t ret;
06c8c691
CH
3008
3009 if (blk_rq_sectors(rq) > max_sectors) {
3010 /*
3011 * SCSI device does not have a good way to return if
3012 * Write Same/Zero is actually supported. If a device rejects
3013 * a non-read/write command (discard, write same,etc.) the
3014 * low-level device driver will set the relevant queue limit to
3015 * 0 to prevent blk-lib from issuing more of the offending
3016 * operations. Commands queued prior to the queue limit being
3017 * reset need to be completed with BLK_STS_NOTSUPP to avoid I/O
3018 * errors being propagated to upper layers.
3019 */
3020 if (max_sectors == 0)
3021 return BLK_STS_NOTSUPP;
3022
3023 printk(KERN_ERR "%s: over max size limit. (%u > %u)\n",
3024 __func__, blk_rq_sectors(rq), max_sectors);
3025 return BLK_STS_IOERR;
3026 }
3027
3028 /*
3029 * The queue settings related to segment counting may differ from the
3030 * original queue.
3031 */
3032 rq->nr_phys_segments = blk_recalc_rq_segments(rq);
49d24398
US
3033 if (rq->nr_phys_segments > max_segments) {
3034 printk(KERN_ERR "%s: over max segments limit. (%u > %u)\n",
3035 __func__, rq->nr_phys_segments, max_segments);
06c8c691
CH
3036 return BLK_STS_IOERR;
3037 }
3038
28db4711 3039 if (q->disk && should_fail_request(q->disk->part0, blk_rq_bytes(rq)))
06c8c691
CH
3040 return BLK_STS_IOERR;
3041
5b8562f0
EB
3042 ret = blk_crypto_rq_get_keyslot(rq);
3043 if (ret != BLK_STS_OK)
3044 return ret;
06c8c691
CH
3045
3046 blk_account_io_start(rq);
3047
3048 /*
3049 * Since we have a scheduler attached on the top device,
3050 * bypass a potential scheduler on the bottom device for
3051 * insert.
3052 */
28db4711 3053 blk_mq_run_dispatch_ops(q,
4cafe86c 3054 ret = blk_mq_request_issue_directly(rq, true));
592ee119
YK
3055 if (ret)
3056 blk_account_io_done(rq, ktime_get_ns());
4cafe86c 3057 return ret;
06c8c691
CH
3058}
3059EXPORT_SYMBOL_GPL(blk_insert_cloned_request);
3060
3061/**
3062 * blk_rq_unprep_clone - Helper function to free all bios in a cloned request
3063 * @rq: the clone request to be cleaned up
3064 *
3065 * Description:
3066 * Free all bios in @rq for a cloned request.
3067 */
3068void blk_rq_unprep_clone(struct request *rq)
3069{
3070 struct bio *bio;
3071
3072 while ((bio = rq->bio) != NULL) {
3073 rq->bio = bio->bi_next;
3074
3075 bio_put(bio);
3076 }
3077}
3078EXPORT_SYMBOL_GPL(blk_rq_unprep_clone);
3079
3080/**
3081 * blk_rq_prep_clone - Helper function to setup clone request
3082 * @rq: the request to be setup
3083 * @rq_src: original request to be cloned
3084 * @bs: bio_set that bios for clone are allocated from
3085 * @gfp_mask: memory allocation mask for bio
3086 * @bio_ctr: setup function to be called for each clone bio.
3087 * Returns %0 for success, non %0 for failure.
3088 * @data: private data to be passed to @bio_ctr
3089 *
3090 * Description:
3091 * Clones bios in @rq_src to @rq, and copies attributes of @rq_src to @rq.
3092 * Also, pages which the original bios are pointing to are not copied
3093 * and the cloned bios just point same pages.
3094 * So cloned bios must be completed before original bios, which means
3095 * the caller must complete @rq before @rq_src.
3096 */
3097int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
3098 struct bio_set *bs, gfp_t gfp_mask,
3099 int (*bio_ctr)(struct bio *, struct bio *, void *),
3100 void *data)
3101{
3102 struct bio *bio, *bio_src;
3103
3104 if (!bs)
3105 bs = &fs_bio_set;
3106
3107 __rq_for_each_bio(bio_src, rq_src) {
abfc426d
CH
3108 bio = bio_alloc_clone(rq->q->disk->part0, bio_src, gfp_mask,
3109 bs);
06c8c691
CH
3110 if (!bio)
3111 goto free_and_out;
3112
3113 if (bio_ctr && bio_ctr(bio, bio_src, data))
3114 goto free_and_out;
3115
3116 if (rq->bio) {
3117 rq->biotail->bi_next = bio;
3118 rq->biotail = bio;
3119 } else {
3120 rq->bio = rq->biotail = bio;
3121 }
3122 bio = NULL;
3123 }
3124
3125 /* Copy attributes of the original request to the clone request. */
3126 rq->__sector = blk_rq_pos(rq_src);
3127 rq->__data_len = blk_rq_bytes(rq_src);
3128 if (rq_src->rq_flags & RQF_SPECIAL_PAYLOAD) {
3129 rq->rq_flags |= RQF_SPECIAL_PAYLOAD;
3130 rq->special_vec = rq_src->special_vec;
3131 }
3132 rq->nr_phys_segments = rq_src->nr_phys_segments;
3133 rq->ioprio = rq_src->ioprio;
3134
3135 if (rq->bio && blk_crypto_rq_bio_prep(rq, rq->bio, gfp_mask) < 0)
3136 goto free_and_out;
3137
3138 return 0;
3139
3140free_and_out:
3141 if (bio)
3142 bio_put(bio);
3143 blk_rq_unprep_clone(rq);
3144
3145 return -ENOMEM;
3146}
3147EXPORT_SYMBOL_GPL(blk_rq_prep_clone);
248c7933 3148#endif /* CONFIG_BLK_MQ_STACKING */
06c8c691 3149
f2b8f3ce
CH
3150/*
3151 * Steal bios from a request and add them to a bio list.
3152 * The request must not have been partially completed before.
3153 */
3154void blk_steal_bios(struct bio_list *list, struct request *rq)
3155{
3156 if (rq->bio) {
3157 if (list->tail)
3158 list->tail->bi_next = rq->bio;
3159 else
3160 list->head = rq->bio;
3161 list->tail = rq->biotail;
3162
3163 rq->bio = NULL;
3164 rq->biotail = NULL;
3165 }
3166
3167 rq->__data_len = 0;
3168}
3169EXPORT_SYMBOL_GPL(blk_steal_bios);
3170
bd63141d
ML
3171static size_t order_to_size(unsigned int order)
3172{
3173 return (size_t)PAGE_SIZE << order;
3174}
3175
3176/* called before freeing request pool in @tags */
f32e4eaf
JG
3177static void blk_mq_clear_rq_mapping(struct blk_mq_tags *drv_tags,
3178 struct blk_mq_tags *tags)
bd63141d 3179{
bd63141d
ML
3180 struct page *page;
3181 unsigned long flags;
3182
76dd2980
YK
3183 /*
3184 * There is no need to clear mapping if driver tags is not initialized
3185 * or the mapping belongs to the driver tags.
3186 */
3187 if (!drv_tags || drv_tags == tags)
4f245d5b
JG
3188 return;
3189
bd63141d
ML
3190 list_for_each_entry(page, &tags->page_list, lru) {
3191 unsigned long start = (unsigned long)page_address(page);
3192 unsigned long end = start + order_to_size(page->private);
3193 int i;
3194
f32e4eaf 3195 for (i = 0; i < drv_tags->nr_tags; i++) {
bd63141d
ML
3196 struct request *rq = drv_tags->rqs[i];
3197 unsigned long rq_addr = (unsigned long)rq;
3198
3199 if (rq_addr >= start && rq_addr < end) {
0a467d0f 3200 WARN_ON_ONCE(req_ref_read(rq) != 0);
bd63141d
ML
3201 cmpxchg(&drv_tags->rqs[i], rq, NULL);
3202 }
3203 }
3204 }
3205
3206 /*
3207 * Wait until all pending iteration is done.
3208 *
3209 * Request reference is cleared and it is guaranteed to be observed
3210 * after the ->lock is released.
3211 */
3212 spin_lock_irqsave(&drv_tags->lock, flags);
3213 spin_unlock_irqrestore(&drv_tags->lock, flags);
3214}
3215
cc71a6f4
JA
3216void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
3217 unsigned int hctx_idx)
95363efd 3218{
f32e4eaf 3219 struct blk_mq_tags *drv_tags;
e9b267d9 3220 struct page *page;
320ae51f 3221
e02657ea
ML
3222 if (list_empty(&tags->page_list))
3223 return;
3224
079a2e3e
JG
3225 if (blk_mq_is_shared_tags(set->flags))
3226 drv_tags = set->shared_tags;
e155b0c2
JG
3227 else
3228 drv_tags = set->tags[hctx_idx];
f32e4eaf 3229
65de57bb 3230 if (tags->static_rqs && set->ops->exit_request) {
e9b267d9 3231 int i;
320ae51f 3232
24d2f903 3233 for (i = 0; i < tags->nr_tags; i++) {
2af8cbe3
JA
3234 struct request *rq = tags->static_rqs[i];
3235
3236 if (!rq)
e9b267d9 3237 continue;
d6296d39 3238 set->ops->exit_request(set, rq, hctx_idx);
2af8cbe3 3239 tags->static_rqs[i] = NULL;
e9b267d9 3240 }
320ae51f 3241 }
320ae51f 3242
f32e4eaf 3243 blk_mq_clear_rq_mapping(drv_tags, tags);
bd63141d 3244
24d2f903
CH
3245 while (!list_empty(&tags->page_list)) {
3246 page = list_first_entry(&tags->page_list, struct page, lru);
6753471c 3247 list_del_init(&page->lru);
f75782e4
CM
3248 /*
3249 * Remove kmemleak object previously allocated in
273938bf 3250 * blk_mq_alloc_rqs().
f75782e4
CM
3251 */
3252 kmemleak_free(page_address(page));
320ae51f
JA
3253 __free_pages(page, page->private);
3254 }
cc71a6f4 3255}
320ae51f 3256
e155b0c2 3257void blk_mq_free_rq_map(struct blk_mq_tags *tags)
cc71a6f4 3258{
24d2f903 3259 kfree(tags->rqs);
cc71a6f4 3260 tags->rqs = NULL;
2af8cbe3
JA
3261 kfree(tags->static_rqs);
3262 tags->static_rqs = NULL;
320ae51f 3263
e155b0c2 3264 blk_mq_free_tags(tags);
320ae51f
JA
3265}
3266
4d805131
ML
3267static enum hctx_type hctx_idx_to_type(struct blk_mq_tag_set *set,
3268 unsigned int hctx_idx)
3269{
3270 int i;
3271
3272 for (i = 0; i < set->nr_maps; i++) {
3273 unsigned int start = set->map[i].queue_offset;
3274 unsigned int end = start + set->map[i].nr_queues;
3275
3276 if (hctx_idx >= start && hctx_idx < end)
3277 break;
3278 }
3279
3280 if (i >= set->nr_maps)
3281 i = HCTX_TYPE_DEFAULT;
3282
3283 return i;
3284}
3285
3286static int blk_mq_get_hctx_node(struct blk_mq_tag_set *set,
3287 unsigned int hctx_idx)
3288{
3289 enum hctx_type type = hctx_idx_to_type(set, hctx_idx);
3290
3291 return blk_mq_hw_queue_to_node(&set->map[type], hctx_idx);
3292}
3293
63064be1
JG
3294static struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
3295 unsigned int hctx_idx,
3296 unsigned int nr_tags,
e155b0c2 3297 unsigned int reserved_tags)
320ae51f 3298{
4d805131 3299 int node = blk_mq_get_hctx_node(set, hctx_idx);
24d2f903 3300 struct blk_mq_tags *tags;
320ae51f 3301
59f082e4
SL
3302 if (node == NUMA_NO_NODE)
3303 node = set->numa_node;
3304
e155b0c2
JG
3305 tags = blk_mq_init_tags(nr_tags, reserved_tags, node,
3306 BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags));
24d2f903
CH
3307 if (!tags)
3308 return NULL;
320ae51f 3309
590b5b7d 3310 tags->rqs = kcalloc_node(nr_tags, sizeof(struct request *),
36e1f3d1 3311 GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY,
59f082e4 3312 node);
7edfd681
JC
3313 if (!tags->rqs)
3314 goto err_free_tags;
320ae51f 3315
590b5b7d
KC
3316 tags->static_rqs = kcalloc_node(nr_tags, sizeof(struct request *),
3317 GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY,
3318 node);
7edfd681
JC
3319 if (!tags->static_rqs)
3320 goto err_free_rqs;
2af8cbe3 3321
cc71a6f4 3322 return tags;
7edfd681
JC
3323
3324err_free_rqs:
3325 kfree(tags->rqs);
3326err_free_tags:
3327 blk_mq_free_tags(tags);
3328 return NULL;
cc71a6f4
JA
3329}
3330
1d9bd516
TH
3331static int blk_mq_init_request(struct blk_mq_tag_set *set, struct request *rq,
3332 unsigned int hctx_idx, int node)
3333{
3334 int ret;
3335
3336 if (set->ops->init_request) {
3337 ret = set->ops->init_request(set, rq, hctx_idx, node);
3338 if (ret)
3339 return ret;
3340 }
3341
12f5b931 3342 WRITE_ONCE(rq->state, MQ_RQ_IDLE);
1d9bd516
TH
3343 return 0;
3344}
3345
63064be1
JG
3346static int blk_mq_alloc_rqs(struct blk_mq_tag_set *set,
3347 struct blk_mq_tags *tags,
3348 unsigned int hctx_idx, unsigned int depth)
cc71a6f4
JA
3349{
3350 unsigned int i, j, entries_per_page, max_order = 4;
4d805131 3351 int node = blk_mq_get_hctx_node(set, hctx_idx);
cc71a6f4 3352 size_t rq_size, left;
59f082e4 3353
59f082e4
SL
3354 if (node == NUMA_NO_NODE)
3355 node = set->numa_node;
cc71a6f4
JA
3356
3357 INIT_LIST_HEAD(&tags->page_list);
3358
320ae51f
JA
3359 /*
3360 * rq_size is the size of the request plus driver payload, rounded
3361 * to the cacheline size
3362 */
24d2f903 3363 rq_size = round_up(sizeof(struct request) + set->cmd_size,
320ae51f 3364 cache_line_size());
cc71a6f4 3365 left = rq_size * depth;
320ae51f 3366
cc71a6f4 3367 for (i = 0; i < depth; ) {
320ae51f
JA
3368 int this_order = max_order;
3369 struct page *page;
3370 int to_do;
3371 void *p;
3372
b3a834b1 3373 while (this_order && left < order_to_size(this_order - 1))
320ae51f
JA
3374 this_order--;
3375
3376 do {
59f082e4 3377 page = alloc_pages_node(node,
36e1f3d1 3378 GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO,
a5164405 3379 this_order);
320ae51f
JA
3380 if (page)
3381 break;
3382 if (!this_order--)
3383 break;
3384 if (order_to_size(this_order) < rq_size)
3385 break;
3386 } while (1);
3387
3388 if (!page)
24d2f903 3389 goto fail;
320ae51f
JA
3390
3391 page->private = this_order;
24d2f903 3392 list_add_tail(&page->lru, &tags->page_list);
320ae51f
JA
3393
3394 p = page_address(page);
f75782e4
CM
3395 /*
3396 * Allow kmemleak to scan these pages as they contain pointers
3397 * to additional allocations like via ops->init_request().
3398 */
36e1f3d1 3399 kmemleak_alloc(p, order_to_size(this_order), 1, GFP_NOIO);
320ae51f 3400 entries_per_page = order_to_size(this_order) / rq_size;
cc71a6f4 3401 to_do = min(entries_per_page, depth - i);
320ae51f
JA
3402 left -= to_do * rq_size;
3403 for (j = 0; j < to_do; j++) {
2af8cbe3
JA
3404 struct request *rq = p;
3405
3406 tags->static_rqs[i] = rq;
1d9bd516
TH
3407 if (blk_mq_init_request(set, rq, hctx_idx, node)) {
3408 tags->static_rqs[i] = NULL;
3409 goto fail;
e9b267d9
CH
3410 }
3411
320ae51f
JA
3412 p += rq_size;
3413 i++;
3414 }
3415 }
cc71a6f4 3416 return 0;
320ae51f 3417
24d2f903 3418fail:
cc71a6f4
JA
3419 blk_mq_free_rqs(set, tags, hctx_idx);
3420 return -ENOMEM;
320ae51f
JA
3421}
3422
bf0beec0
ML
3423struct rq_iter_data {
3424 struct blk_mq_hw_ctx *hctx;
3425 bool has_rq;
3426};
3427
2dd6532e 3428static bool blk_mq_has_request(struct request *rq, void *data)
bf0beec0
ML
3429{
3430 struct rq_iter_data *iter_data = data;
3431
3432 if (rq->mq_hctx != iter_data->hctx)
3433 return true;
3434 iter_data->has_rq = true;
3435 return false;
3436}
3437
3438static bool blk_mq_hctx_has_requests(struct blk_mq_hw_ctx *hctx)
3439{
3440 struct blk_mq_tags *tags = hctx->sched_tags ?
3441 hctx->sched_tags : hctx->tags;
3442 struct rq_iter_data data = {
3443 .hctx = hctx,
3444 };
3445
3446 blk_mq_all_tag_iter(tags, blk_mq_has_request, &data);
3447 return data.has_rq;
3448}
3449
3450static inline bool blk_mq_last_cpu_in_hctx(unsigned int cpu,
3451 struct blk_mq_hw_ctx *hctx)
3452{
9b51d9d8 3453 if (cpumask_first_and(hctx->cpumask, cpu_online_mask) != cpu)
bf0beec0
ML
3454 return false;
3455 if (cpumask_next_and(cpu, hctx->cpumask, cpu_online_mask) < nr_cpu_ids)
3456 return false;
3457 return true;
3458}
3459
3460static int blk_mq_hctx_notify_offline(unsigned int cpu, struct hlist_node *node)
3461{
3462 struct blk_mq_hw_ctx *hctx = hlist_entry_safe(node,
3463 struct blk_mq_hw_ctx, cpuhp_online);
3464
3465 if (!cpumask_test_cpu(cpu, hctx->cpumask) ||
3466 !blk_mq_last_cpu_in_hctx(cpu, hctx))
3467 return 0;
3468
3469 /*
3470 * Prevent new request from being allocated on the current hctx.
3471 *
3472 * The smp_mb__after_atomic() Pairs with the implied barrier in
3473 * test_and_set_bit_lock in sbitmap_get(). Ensures the inactive flag is
3474 * seen once we return from the tag allocator.
3475 */
3476 set_bit(BLK_MQ_S_INACTIVE, &hctx->state);
3477 smp_mb__after_atomic();
3478
3479 /*
3480 * Try to grab a reference to the queue and wait for any outstanding
3481 * requests. If we could not grab a reference the queue has been
3482 * frozen and there are no requests.
3483 */
3484 if (percpu_ref_tryget(&hctx->queue->q_usage_counter)) {
3485 while (blk_mq_hctx_has_requests(hctx))
3486 msleep(5);
3487 percpu_ref_put(&hctx->queue->q_usage_counter);
3488 }
3489
3490 return 0;
3491}
3492
3493static int blk_mq_hctx_notify_online(unsigned int cpu, struct hlist_node *node)
3494{
3495 struct blk_mq_hw_ctx *hctx = hlist_entry_safe(node,
3496 struct blk_mq_hw_ctx, cpuhp_online);
3497
3498 if (cpumask_test_cpu(cpu, hctx->cpumask))
3499 clear_bit(BLK_MQ_S_INACTIVE, &hctx->state);
3500 return 0;
3501}
3502
e57690fe
JA
3503/*
3504 * 'cpu' is going away. splice any existing rq_list entries from this
3505 * software queue to the hw queue dispatch list, and ensure that it
3506 * gets run.
3507 */
9467f859 3508static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node)
484b4061 3509{
9467f859 3510 struct blk_mq_hw_ctx *hctx;
484b4061
JA
3511 struct blk_mq_ctx *ctx;
3512 LIST_HEAD(tmp);
c16d6b5a 3513 enum hctx_type type;
484b4061 3514
9467f859 3515 hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_dead);
bf0beec0
ML
3516 if (!cpumask_test_cpu(cpu, hctx->cpumask))
3517 return 0;
3518
e57690fe 3519 ctx = __blk_mq_get_ctx(hctx->queue, cpu);
c16d6b5a 3520 type = hctx->type;
484b4061
JA
3521
3522 spin_lock(&ctx->lock);
c16d6b5a
ML
3523 if (!list_empty(&ctx->rq_lists[type])) {
3524 list_splice_init(&ctx->rq_lists[type], &tmp);
484b4061
JA
3525 blk_mq_hctx_clear_pending(hctx, ctx);
3526 }
3527 spin_unlock(&ctx->lock);
3528
3529 if (list_empty(&tmp))
9467f859 3530 return 0;
484b4061 3531
e57690fe
JA
3532 spin_lock(&hctx->lock);
3533 list_splice_tail_init(&tmp, &hctx->dispatch);
3534 spin_unlock(&hctx->lock);
484b4061
JA
3535
3536 blk_mq_run_hw_queue(hctx, true);
9467f859 3537 return 0;
484b4061
JA
3538}
3539
9467f859 3540static void blk_mq_remove_cpuhp(struct blk_mq_hw_ctx *hctx)
484b4061 3541{
bf0beec0
ML
3542 if (!(hctx->flags & BLK_MQ_F_STACKING))
3543 cpuhp_state_remove_instance_nocalls(CPUHP_AP_BLK_MQ_ONLINE,
3544 &hctx->cpuhp_online);
9467f859
TG
3545 cpuhp_state_remove_instance_nocalls(CPUHP_BLK_MQ_DEAD,
3546 &hctx->cpuhp_dead);
484b4061
JA
3547}
3548
364b6181
ML
3549/*
3550 * Before freeing hw queue, clearing the flush request reference in
3551 * tags->rqs[] for avoiding potential UAF.
3552 */
3553static void blk_mq_clear_flush_rq_mapping(struct blk_mq_tags *tags,
3554 unsigned int queue_depth, struct request *flush_rq)
3555{
3556 int i;
3557 unsigned long flags;
3558
3559 /* The hw queue may not be mapped yet */
3560 if (!tags)
3561 return;
3562
0a467d0f 3563 WARN_ON_ONCE(req_ref_read(flush_rq) != 0);
364b6181
ML
3564
3565 for (i = 0; i < queue_depth; i++)
3566 cmpxchg(&tags->rqs[i], flush_rq, NULL);
3567
3568 /*
3569 * Wait until all pending iteration is done.
3570 *
3571 * Request reference is cleared and it is guaranteed to be observed
3572 * after the ->lock is released.
3573 */
3574 spin_lock_irqsave(&tags->lock, flags);
3575 spin_unlock_irqrestore(&tags->lock, flags);
3576}
3577
c3b4afca 3578/* hctx->ctxs will be freed in queue's release handler */
08e98fc6
ML
3579static void blk_mq_exit_hctx(struct request_queue *q,
3580 struct blk_mq_tag_set *set,
3581 struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
3582{
364b6181
ML
3583 struct request *flush_rq = hctx->fq->flush_rq;
3584
8ab0b7dc
ML
3585 if (blk_mq_hw_queue_mapped(hctx))
3586 blk_mq_tag_idle(hctx);
08e98fc6 3587
6cfeadbf
ML
3588 if (blk_queue_init_done(q))
3589 blk_mq_clear_flush_rq_mapping(set->tags[hctx_idx],
3590 set->queue_depth, flush_rq);
f70ced09 3591 if (set->ops->exit_request)
364b6181 3592 set->ops->exit_request(set, flush_rq, hctx_idx);
f70ced09 3593
08e98fc6
ML
3594 if (set->ops->exit_hctx)
3595 set->ops->exit_hctx(hctx, hctx_idx);
3596
9467f859 3597 blk_mq_remove_cpuhp(hctx);
2f8f1336 3598
4e5cc99e
ML
3599 xa_erase(&q->hctx_table, hctx_idx);
3600
2f8f1336
ML
3601 spin_lock(&q->unused_hctx_lock);
3602 list_add(&hctx->hctx_list, &q->unused_hctx_list);
3603 spin_unlock(&q->unused_hctx_lock);
08e98fc6
ML
3604}
3605
624dbe47
ML
3606static void blk_mq_exit_hw_queues(struct request_queue *q,
3607 struct blk_mq_tag_set *set, int nr_queue)
3608{
3609 struct blk_mq_hw_ctx *hctx;
4f481208 3610 unsigned long i;
624dbe47
ML
3611
3612 queue_for_each_hw_ctx(q, hctx, i) {
3613 if (i == nr_queue)
3614 break;
08e98fc6 3615 blk_mq_exit_hctx(q, set, hctx, i);
624dbe47 3616 }
624dbe47
ML
3617}
3618
08e98fc6
ML
3619static int blk_mq_init_hctx(struct request_queue *q,
3620 struct blk_mq_tag_set *set,
3621 struct blk_mq_hw_ctx *hctx, unsigned hctx_idx)
320ae51f 3622{
7c6c5b7c
ML
3623 hctx->queue_num = hctx_idx;
3624
bf0beec0
ML
3625 if (!(hctx->flags & BLK_MQ_F_STACKING))
3626 cpuhp_state_add_instance_nocalls(CPUHP_AP_BLK_MQ_ONLINE,
3627 &hctx->cpuhp_online);
7c6c5b7c
ML
3628 cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, &hctx->cpuhp_dead);
3629
3630 hctx->tags = set->tags[hctx_idx];
3631
3632 if (set->ops->init_hctx &&
3633 set->ops->init_hctx(hctx, set->driver_data, hctx_idx))
3634 goto unregister_cpu_notifier;
08e98fc6 3635
7c6c5b7c
ML
3636 if (blk_mq_init_request(set, hctx->fq->flush_rq, hctx_idx,
3637 hctx->numa_node))
3638 goto exit_hctx;
4e5cc99e
ML
3639
3640 if (xa_insert(&q->hctx_table, hctx_idx, hctx, GFP_KERNEL))
3641 goto exit_flush_rq;
3642
7c6c5b7c
ML
3643 return 0;
3644
4e5cc99e
ML
3645 exit_flush_rq:
3646 if (set->ops->exit_request)
3647 set->ops->exit_request(set, hctx->fq->flush_rq, hctx_idx);
7c6c5b7c
ML
3648 exit_hctx:
3649 if (set->ops->exit_hctx)
3650 set->ops->exit_hctx(hctx, hctx_idx);
3651 unregister_cpu_notifier:
3652 blk_mq_remove_cpuhp(hctx);
3653 return -1;
3654}
3655
3656static struct blk_mq_hw_ctx *
3657blk_mq_alloc_hctx(struct request_queue *q, struct blk_mq_tag_set *set,
3658 int node)
3659{
3660 struct blk_mq_hw_ctx *hctx;
3661 gfp_t gfp = GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY;
3662
704b914f 3663 hctx = kzalloc_node(sizeof(struct blk_mq_hw_ctx), gfp, node);
7c6c5b7c
ML
3664 if (!hctx)
3665 goto fail_alloc_hctx;
3666
3667 if (!zalloc_cpumask_var_node(&hctx->cpumask, gfp, node))
3668 goto free_hctx;
3669
3670 atomic_set(&hctx->nr_active, 0);
08e98fc6 3671 if (node == NUMA_NO_NODE)
7c6c5b7c
ML
3672 node = set->numa_node;
3673 hctx->numa_node = node;
08e98fc6 3674
9f993737 3675 INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn);
08e98fc6
ML
3676 spin_lock_init(&hctx->lock);
3677 INIT_LIST_HEAD(&hctx->dispatch);
3678 hctx->queue = q;
51db1c37 3679 hctx->flags = set->flags & ~BLK_MQ_F_TAG_QUEUE_SHARED;
08e98fc6 3680
2f8f1336
ML
3681 INIT_LIST_HEAD(&hctx->hctx_list);
3682
320ae51f 3683 /*
08e98fc6
ML
3684 * Allocate space for all possible cpus to avoid allocation at
3685 * runtime
320ae51f 3686 */
d904bfa7 3687 hctx->ctxs = kmalloc_array_node(nr_cpu_ids, sizeof(void *),
7c6c5b7c 3688 gfp, node);
08e98fc6 3689 if (!hctx->ctxs)
7c6c5b7c 3690 goto free_cpumask;
320ae51f 3691
5b202853 3692 if (sbitmap_init_node(&hctx->ctx_map, nr_cpu_ids, ilog2(8),
c548e62b 3693 gfp, node, false, false))
08e98fc6 3694 goto free_ctxs;
08e98fc6 3695 hctx->nr_ctx = 0;
320ae51f 3696
5815839b 3697 spin_lock_init(&hctx->dispatch_wait_lock);
eb619fdb
JA
3698 init_waitqueue_func_entry(&hctx->dispatch_wait, blk_mq_dispatch_wake);
3699 INIT_LIST_HEAD(&hctx->dispatch_wait.entry);
3700
754a1572 3701 hctx->fq = blk_alloc_flush_queue(hctx->numa_node, set->cmd_size, gfp);
f70ced09 3702 if (!hctx->fq)
7c6c5b7c 3703 goto free_bitmap;
320ae51f 3704
7c6c5b7c 3705 blk_mq_hctx_kobj_init(hctx);
6a83e74d 3706
7c6c5b7c 3707 return hctx;
320ae51f 3708
08e98fc6 3709 free_bitmap:
88459642 3710 sbitmap_free(&hctx->ctx_map);
08e98fc6
ML
3711 free_ctxs:
3712 kfree(hctx->ctxs);
7c6c5b7c
ML
3713 free_cpumask:
3714 free_cpumask_var(hctx->cpumask);
3715 free_hctx:
3716 kfree(hctx);
3717 fail_alloc_hctx:
3718 return NULL;
08e98fc6 3719}
320ae51f 3720
320ae51f
JA
3721static void blk_mq_init_cpu_queues(struct request_queue *q,
3722 unsigned int nr_hw_queues)
3723{
b3c661b1
JA
3724 struct blk_mq_tag_set *set = q->tag_set;
3725 unsigned int i, j;
320ae51f
JA
3726
3727 for_each_possible_cpu(i) {
3728 struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i);
3729 struct blk_mq_hw_ctx *hctx;
c16d6b5a 3730 int k;
320ae51f 3731
320ae51f
JA
3732 __ctx->cpu = i;
3733 spin_lock_init(&__ctx->lock);
c16d6b5a
ML
3734 for (k = HCTX_TYPE_DEFAULT; k < HCTX_MAX_TYPES; k++)
3735 INIT_LIST_HEAD(&__ctx->rq_lists[k]);
3736
320ae51f
JA
3737 __ctx->queue = q;
3738
320ae51f
JA
3739 /*
3740 * Set local node, IFF we have more than one hw queue. If
3741 * not, we remain on the home node of the device
3742 */
b3c661b1
JA
3743 for (j = 0; j < set->nr_maps; j++) {
3744 hctx = blk_mq_map_queue_type(q, j, i);
3745 if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE)
576e85c5 3746 hctx->numa_node = cpu_to_node(i);
b3c661b1 3747 }
320ae51f
JA
3748 }
3749}
3750
63064be1
JG
3751struct blk_mq_tags *blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set,
3752 unsigned int hctx_idx,
3753 unsigned int depth)
cc71a6f4 3754{
63064be1
JG
3755 struct blk_mq_tags *tags;
3756 int ret;
cc71a6f4 3757
e155b0c2 3758 tags = blk_mq_alloc_rq_map(set, hctx_idx, depth, set->reserved_tags);
63064be1
JG
3759 if (!tags)
3760 return NULL;
cc71a6f4 3761
63064be1
JG
3762 ret = blk_mq_alloc_rqs(set, tags, hctx_idx, depth);
3763 if (ret) {
e155b0c2 3764 blk_mq_free_rq_map(tags);
63064be1
JG
3765 return NULL;
3766 }
cc71a6f4 3767
63064be1 3768 return tags;
cc71a6f4
JA
3769}
3770
63064be1
JG
3771static bool __blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set,
3772 int hctx_idx)
cc71a6f4 3773{
079a2e3e
JG
3774 if (blk_mq_is_shared_tags(set->flags)) {
3775 set->tags[hctx_idx] = set->shared_tags;
1c0706a7 3776
e155b0c2 3777 return true;
bd166ef1 3778 }
e155b0c2 3779
63064be1
JG
3780 set->tags[hctx_idx] = blk_mq_alloc_map_and_rqs(set, hctx_idx,
3781 set->queue_depth);
3782
3783 return set->tags[hctx_idx];
cc71a6f4
JA
3784}
3785
645db34e
JG
3786void blk_mq_free_map_and_rqs(struct blk_mq_tag_set *set,
3787 struct blk_mq_tags *tags,
3788 unsigned int hctx_idx)
cc71a6f4 3789{
645db34e
JG
3790 if (tags) {
3791 blk_mq_free_rqs(set, tags, hctx_idx);
e155b0c2 3792 blk_mq_free_rq_map(tags);
bd166ef1 3793 }
cc71a6f4
JA
3794}
3795
e155b0c2
JG
3796static void __blk_mq_free_map_and_rqs(struct blk_mq_tag_set *set,
3797 unsigned int hctx_idx)
3798{
079a2e3e 3799 if (!blk_mq_is_shared_tags(set->flags))
e155b0c2
JG
3800 blk_mq_free_map_and_rqs(set, set->tags[hctx_idx], hctx_idx);
3801
3802 set->tags[hctx_idx] = NULL;
cc71a6f4
JA
3803}
3804
4b855ad3 3805static void blk_mq_map_swqueue(struct request_queue *q)
320ae51f 3806{
4f481208
ML
3807 unsigned int j, hctx_idx;
3808 unsigned long i;
320ae51f
JA
3809 struct blk_mq_hw_ctx *hctx;
3810 struct blk_mq_ctx *ctx;
2a34c087 3811 struct blk_mq_tag_set *set = q->tag_set;
320ae51f
JA
3812
3813 queue_for_each_hw_ctx(q, hctx, i) {
e4043dcf 3814 cpumask_clear(hctx->cpumask);
320ae51f 3815 hctx->nr_ctx = 0;
d416c92c 3816 hctx->dispatch_from = NULL;
320ae51f
JA
3817 }
3818
3819 /*
4b855ad3 3820 * Map software to hardware queues.
4412efec
ML
3821 *
3822 * If the cpu isn't present, the cpu is mapped to first hctx.
320ae51f 3823 */
20e4d813 3824 for_each_possible_cpu(i) {
4412efec 3825
897bb0c7 3826 ctx = per_cpu_ptr(q->queue_ctx, i);
b3c661b1 3827 for (j = 0; j < set->nr_maps; j++) {
bb94aea1
JW
3828 if (!set->map[j].nr_queues) {
3829 ctx->hctxs[j] = blk_mq_map_queue_type(q,
3830 HCTX_TYPE_DEFAULT, i);
e5edd5f2 3831 continue;
bb94aea1 3832 }
fd689871
ML
3833 hctx_idx = set->map[j].mq_map[i];
3834 /* unmapped hw queue can be remapped after CPU topo changed */
3835 if (!set->tags[hctx_idx] &&
63064be1 3836 !__blk_mq_alloc_map_and_rqs(set, hctx_idx)) {
fd689871
ML
3837 /*
3838 * If tags initialization fail for some hctx,
3839 * that hctx won't be brought online. In this
3840 * case, remap the current ctx to hctx[0] which
3841 * is guaranteed to always have tags allocated
3842 */
3843 set->map[j].mq_map[i] = 0;
3844 }
e5edd5f2 3845
b3c661b1 3846 hctx = blk_mq_map_queue_type(q, j, i);
8ccdf4a3 3847 ctx->hctxs[j] = hctx;
b3c661b1
JA
3848 /*
3849 * If the CPU is already set in the mask, then we've
3850 * mapped this one already. This can happen if
3851 * devices share queues across queue maps.
3852 */
3853 if (cpumask_test_cpu(i, hctx->cpumask))
3854 continue;
3855
3856 cpumask_set_cpu(i, hctx->cpumask);
3857 hctx->type = j;
3858 ctx->index_hw[hctx->type] = hctx->nr_ctx;
3859 hctx->ctxs[hctx->nr_ctx++] = ctx;
3860
3861 /*
3862 * If the nr_ctx type overflows, we have exceeded the
3863 * amount of sw queues we can support.
3864 */
3865 BUG_ON(!hctx->nr_ctx);
3866 }
bb94aea1
JW
3867
3868 for (; j < HCTX_MAX_TYPES; j++)
3869 ctx->hctxs[j] = blk_mq_map_queue_type(q,
3870 HCTX_TYPE_DEFAULT, i);
320ae51f 3871 }
506e931f
JA
3872
3873 queue_for_each_hw_ctx(q, hctx, i) {
4412efec
ML
3874 /*
3875 * If no software queues are mapped to this hardware queue,
3876 * disable it and free the request entries.
3877 */
3878 if (!hctx->nr_ctx) {
3879 /* Never unmap queue 0. We need it as a
3880 * fallback in case of a new remap fails
3881 * allocation
3882 */
e155b0c2
JG
3883 if (i)
3884 __blk_mq_free_map_and_rqs(set, i);
4412efec
ML
3885
3886 hctx->tags = NULL;
3887 continue;
3888 }
484b4061 3889
2a34c087
ML
3890 hctx->tags = set->tags[i];
3891 WARN_ON(!hctx->tags);
3892
889fa31f
CY
3893 /*
3894 * Set the map size to the number of mapped software queues.
3895 * This is more accurate and more efficient than looping
3896 * over all possibly mapped software queues.
3897 */
88459642 3898 sbitmap_resize(&hctx->ctx_map, hctx->nr_ctx);
889fa31f 3899
484b4061
JA
3900 /*
3901 * Initialize batch roundrobin counts
3902 */
f82ddf19 3903 hctx->next_cpu = blk_mq_first_mapped_cpu(hctx);
506e931f
JA
3904 hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
3905 }
320ae51f
JA
3906}
3907
8e8320c9
JA
3908/*
3909 * Caller needs to ensure that we're either frozen/quiesced, or that
3910 * the queue isn't live yet.
3911 */
2404e607 3912static void queue_set_hctx_shared(struct request_queue *q, bool shared)
0d2602ca
JA
3913{
3914 struct blk_mq_hw_ctx *hctx;
4f481208 3915 unsigned long i;
0d2602ca 3916
2404e607 3917 queue_for_each_hw_ctx(q, hctx, i) {
454bb677 3918 if (shared) {
51db1c37 3919 hctx->flags |= BLK_MQ_F_TAG_QUEUE_SHARED;
454bb677
YK
3920 } else {
3921 blk_mq_tag_idle(hctx);
51db1c37 3922 hctx->flags &= ~BLK_MQ_F_TAG_QUEUE_SHARED;
454bb677 3923 }
2404e607
JM
3924 }
3925}
3926
655ac300
HR
3927static void blk_mq_update_tag_set_shared(struct blk_mq_tag_set *set,
3928 bool shared)
2404e607
JM
3929{
3930 struct request_queue *q;
0d2602ca 3931
705cda97
BVA
3932 lockdep_assert_held(&set->tag_list_lock);
3933
0d2602ca
JA
3934 list_for_each_entry(q, &set->tag_list, tag_set_list) {
3935 blk_mq_freeze_queue(q);
2404e607 3936 queue_set_hctx_shared(q, shared);
0d2602ca
JA
3937 blk_mq_unfreeze_queue(q);
3938 }
3939}
3940
3941static void blk_mq_del_queue_tag_set(struct request_queue *q)
3942{
3943 struct blk_mq_tag_set *set = q->tag_set;
3944
0d2602ca 3945 mutex_lock(&set->tag_list_lock);
08c875cb 3946 list_del(&q->tag_set_list);
2404e607
JM
3947 if (list_is_singular(&set->tag_list)) {
3948 /* just transitioned to unshared */
51db1c37 3949 set->flags &= ~BLK_MQ_F_TAG_QUEUE_SHARED;
2404e607 3950 /* update existing queue */
655ac300 3951 blk_mq_update_tag_set_shared(set, false);
2404e607 3952 }
0d2602ca 3953 mutex_unlock(&set->tag_list_lock);
a347c7ad 3954 INIT_LIST_HEAD(&q->tag_set_list);
0d2602ca
JA
3955}
3956
3957static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set,
3958 struct request_queue *q)
3959{
0d2602ca 3960 mutex_lock(&set->tag_list_lock);
2404e607 3961
ff821d27
JA
3962 /*
3963 * Check to see if we're transitioning to shared (from 1 to 2 queues).
3964 */
3965 if (!list_empty(&set->tag_list) &&
51db1c37
ML
3966 !(set->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) {
3967 set->flags |= BLK_MQ_F_TAG_QUEUE_SHARED;
2404e607 3968 /* update existing queue */
655ac300 3969 blk_mq_update_tag_set_shared(set, true);
2404e607 3970 }
51db1c37 3971 if (set->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
2404e607 3972 queue_set_hctx_shared(q, true);
08c875cb 3973 list_add_tail(&q->tag_set_list, &set->tag_list);
2404e607 3974
0d2602ca
JA
3975 mutex_unlock(&set->tag_list_lock);
3976}
3977
1db4909e
ML
3978/* All allocations will be freed in release handler of q->mq_kobj */
3979static int blk_mq_alloc_ctxs(struct request_queue *q)
3980{
3981 struct blk_mq_ctxs *ctxs;
3982 int cpu;
3983
3984 ctxs = kzalloc(sizeof(*ctxs), GFP_KERNEL);
3985 if (!ctxs)
3986 return -ENOMEM;
3987
3988 ctxs->queue_ctx = alloc_percpu(struct blk_mq_ctx);
3989 if (!ctxs->queue_ctx)
3990 goto fail;
3991
3992 for_each_possible_cpu(cpu) {
3993 struct blk_mq_ctx *ctx = per_cpu_ptr(ctxs->queue_ctx, cpu);
3994 ctx->ctxs = ctxs;
3995 }
3996
3997 q->mq_kobj = &ctxs->kobj;
3998 q->queue_ctx = ctxs->queue_ctx;
3999
4000 return 0;
4001 fail:
4002 kfree(ctxs);
4003 return -ENOMEM;
4004}
4005
e09aae7e
ML
4006/*
4007 * It is the actual release handler for mq, but we do it from
4008 * request queue's release handler for avoiding use-after-free
4009 * and headache because q->mq_kobj shouldn't have been introduced,
4010 * but we can't group ctx/kctx kobj without it.
4011 */
4012void blk_mq_release(struct request_queue *q)
4013{
2f8f1336 4014 struct blk_mq_hw_ctx *hctx, *next;
4f481208 4015 unsigned long i;
e09aae7e 4016
2f8f1336
ML
4017 queue_for_each_hw_ctx(q, hctx, i)
4018 WARN_ON_ONCE(hctx && list_empty(&hctx->hctx_list));
4019
4020 /* all hctx are in .unused_hctx_list now */
4021 list_for_each_entry_safe(hctx, next, &q->unused_hctx_list, hctx_list) {
4022 list_del_init(&hctx->hctx_list);
6c8b232e 4023 kobject_put(&hctx->kobj);
c3b4afca 4024 }
e09aae7e 4025
4e5cc99e 4026 xa_destroy(&q->hctx_table);
e09aae7e 4027
7ea5fe31
ML
4028 /*
4029 * release .mq_kobj and sw queue's kobject now because
4030 * both share lifetime with request queue.
4031 */
4032 blk_mq_sysfs_deinit(q);
e09aae7e
ML
4033}
4034
5ec780a6 4035static struct request_queue *blk_mq_init_queue_data(struct blk_mq_tag_set *set,
2f227bb9 4036 void *queuedata)
b62c21b7 4037{
26a9750a
CH
4038 struct request_queue *q;
4039 int ret;
b62c21b7 4040
80bd4a7a 4041 q = blk_alloc_queue(set->numa_node);
26a9750a 4042 if (!q)
b62c21b7 4043 return ERR_PTR(-ENOMEM);
26a9750a
CH
4044 q->queuedata = queuedata;
4045 ret = blk_mq_init_allocated_queue(set, q);
4046 if (ret) {
6f8191fd 4047 blk_put_queue(q);
26a9750a
CH
4048 return ERR_PTR(ret);
4049 }
b62c21b7
MS
4050 return q;
4051}
2f227bb9
CH
4052
4053struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
4054{
4055 return blk_mq_init_queue_data(set, NULL);
4056}
b62c21b7
MS
4057EXPORT_SYMBOL(blk_mq_init_queue);
4058
6f8191fd
CH
4059/**
4060 * blk_mq_destroy_queue - shutdown a request queue
4061 * @q: request queue to shutdown
4062 *
81ea42b9
BVA
4063 * This shuts down a request queue allocated by blk_mq_init_queue(). All future
4064 * requests will be failed with -ENODEV. The caller is responsible for dropping
4065 * the reference from blk_mq_init_queue() by calling blk_put_queue().
6f8191fd
CH
4066 *
4067 * Context: can sleep
4068 */
4069void blk_mq_destroy_queue(struct request_queue *q)
4070{
4071 WARN_ON_ONCE(!queue_is_mq(q));
4072 WARN_ON_ONCE(blk_queue_registered(q));
4073
4074 might_sleep();
4075
4076 blk_queue_flag_set(QUEUE_FLAG_DYING, q);
4077 blk_queue_start_drain(q);
56c1ee92 4078 blk_mq_freeze_queue_wait(q);
6f8191fd
CH
4079
4080 blk_sync_queue(q);
4081 blk_mq_cancel_work_sync(q);
4082 blk_mq_exit_queue(q);
6f8191fd
CH
4083}
4084EXPORT_SYMBOL(blk_mq_destroy_queue);
4085
4dcc4874
CH
4086struct gendisk *__blk_mq_alloc_disk(struct blk_mq_tag_set *set, void *queuedata,
4087 struct lock_class_key *lkclass)
9316a9ed
JA
4088{
4089 struct request_queue *q;
b461dfc4 4090 struct gendisk *disk;
9316a9ed 4091
b461dfc4
CH
4092 q = blk_mq_init_queue_data(set, queuedata);
4093 if (IS_ERR(q))
4094 return ERR_CAST(q);
9316a9ed 4095
4a1fa41d 4096 disk = __alloc_disk_node(q, set->numa_node, lkclass);
b461dfc4 4097 if (!disk) {
0a3e5cc7 4098 blk_mq_destroy_queue(q);
2b3f056f 4099 blk_put_queue(q);
b461dfc4 4100 return ERR_PTR(-ENOMEM);
9316a9ed 4101 }
6f8191fd 4102 set_bit(GD_OWNS_QUEUE, &disk->state);
b461dfc4 4103 return disk;
9316a9ed 4104}
b461dfc4 4105EXPORT_SYMBOL(__blk_mq_alloc_disk);
9316a9ed 4106
6f8191fd
CH
4107struct gendisk *blk_mq_alloc_disk_for_queue(struct request_queue *q,
4108 struct lock_class_key *lkclass)
4109{
22c17e27
CH
4110 struct gendisk *disk;
4111
6f8191fd
CH
4112 if (!blk_get_queue(q))
4113 return NULL;
22c17e27
CH
4114 disk = __alloc_disk_node(q, NUMA_NO_NODE, lkclass);
4115 if (!disk)
4116 blk_put_queue(q);
4117 return disk;
6f8191fd
CH
4118}
4119EXPORT_SYMBOL(blk_mq_alloc_disk_for_queue);
4120
34d11ffa
JW
4121static struct blk_mq_hw_ctx *blk_mq_alloc_and_init_hctx(
4122 struct blk_mq_tag_set *set, struct request_queue *q,
4123 int hctx_idx, int node)
4124{
2f8f1336 4125 struct blk_mq_hw_ctx *hctx = NULL, *tmp;
34d11ffa 4126
2f8f1336
ML
4127 /* reuse dead hctx first */
4128 spin_lock(&q->unused_hctx_lock);
4129 list_for_each_entry(tmp, &q->unused_hctx_list, hctx_list) {
4130 if (tmp->numa_node == node) {
4131 hctx = tmp;
4132 break;
4133 }
4134 }
4135 if (hctx)
4136 list_del_init(&hctx->hctx_list);
4137 spin_unlock(&q->unused_hctx_lock);
4138
4139 if (!hctx)
4140 hctx = blk_mq_alloc_hctx(q, set, node);
34d11ffa 4141 if (!hctx)
7c6c5b7c 4142 goto fail;
34d11ffa 4143
7c6c5b7c
ML
4144 if (blk_mq_init_hctx(q, set, hctx, hctx_idx))
4145 goto free_hctx;
34d11ffa
JW
4146
4147 return hctx;
7c6c5b7c
ML
4148
4149 free_hctx:
4150 kobject_put(&hctx->kobj);
4151 fail:
4152 return NULL;
34d11ffa
JW
4153}
4154
868f2f0b
KB
4155static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set,
4156 struct request_queue *q)
320ae51f 4157{
4e5cc99e
ML
4158 struct blk_mq_hw_ctx *hctx;
4159 unsigned long i, j;
ac0d6b92 4160
fb350e0a
ML
4161 /* protect against switching io scheduler */
4162 mutex_lock(&q->sysfs_lock);
24d2f903 4163 for (i = 0; i < set->nr_hw_queues; i++) {
306f13ee 4164 int old_node;
4d805131 4165 int node = blk_mq_get_hctx_node(set, i);
4e5cc99e 4166 struct blk_mq_hw_ctx *old_hctx = xa_load(&q->hctx_table, i);
868f2f0b 4167
306f13ee
ML
4168 if (old_hctx) {
4169 old_node = old_hctx->numa_node;
4170 blk_mq_exit_hctx(q, set, old_hctx, i);
4171 }
868f2f0b 4172
4e5cc99e 4173 if (!blk_mq_alloc_and_init_hctx(set, q, i, node)) {
306f13ee 4174 if (!old_hctx)
34d11ffa 4175 break;
306f13ee
ML
4176 pr_warn("Allocate new hctx on node %d fails, fallback to previous one on node %d\n",
4177 node, old_node);
4e5cc99e
ML
4178 hctx = blk_mq_alloc_and_init_hctx(set, q, i, old_node);
4179 WARN_ON_ONCE(!hctx);
868f2f0b 4180 }
320ae51f 4181 }
e01ad46d
JW
4182 /*
4183 * Increasing nr_hw_queues fails. Free the newly allocated
4184 * hctxs and keep the previous q->nr_hw_queues.
4185 */
4186 if (i != set->nr_hw_queues) {
4187 j = q->nr_hw_queues;
e01ad46d
JW
4188 } else {
4189 j = i;
e01ad46d
JW
4190 q->nr_hw_queues = set->nr_hw_queues;
4191 }
34d11ffa 4192
4e5cc99e
ML
4193 xa_for_each_start(&q->hctx_table, j, hctx, j)
4194 blk_mq_exit_hctx(q, set, hctx, j);
fb350e0a 4195 mutex_unlock(&q->sysfs_lock);
868f2f0b
KB
4196}
4197
42ee3061
ML
4198static void blk_mq_update_poll_flag(struct request_queue *q)
4199{
4200 struct blk_mq_tag_set *set = q->tag_set;
4201
4202 if (set->nr_maps > HCTX_TYPE_POLL &&
4203 set->map[HCTX_TYPE_POLL].nr_queues)
4204 blk_queue_flag_set(QUEUE_FLAG_POLL, q);
4205 else
4206 blk_queue_flag_clear(QUEUE_FLAG_POLL, q);
4207}
4208
26a9750a
CH
4209int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
4210 struct request_queue *q)
868f2f0b 4211{
66841672
ML
4212 /* mark the queue as mq asap */
4213 q->mq_ops = set->ops;
4214
1db4909e 4215 if (blk_mq_alloc_ctxs(q))
54bdd67d 4216 goto err_exit;
868f2f0b 4217
737f98cf
ML
4218 /* init q->mq_kobj and sw queues' kobjects */
4219 blk_mq_sysfs_init(q);
4220
2f8f1336
ML
4221 INIT_LIST_HEAD(&q->unused_hctx_list);
4222 spin_lock_init(&q->unused_hctx_lock);
4223
4e5cc99e
ML
4224 xa_init(&q->hctx_table);
4225
868f2f0b
KB
4226 blk_mq_realloc_hw_ctxs(set, q);
4227 if (!q->nr_hw_queues)
4228 goto err_hctxs;
320ae51f 4229
287922eb 4230 INIT_WORK(&q->timeout_work, blk_mq_timeout_work);
e56f698b 4231 blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ);
320ae51f 4232
a8908939 4233 q->tag_set = set;
320ae51f 4234
94eddfbe 4235 q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;
42ee3061 4236 blk_mq_update_poll_flag(q);
320ae51f 4237
2849450a 4238 INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work);
9a67aa52 4239 INIT_LIST_HEAD(&q->flush_list);
6fca6a61
CH
4240 INIT_LIST_HEAD(&q->requeue_list);
4241 spin_lock_init(&q->requeue_lock);
4242
eba71768
JA
4243 q->nr_requests = set->queue_depth;
4244
24d2f903 4245 blk_mq_init_cpu_queues(q, set->nr_hw_queues);
0d2602ca 4246 blk_mq_add_queue_tag_set(set, q);
4b855ad3 4247 blk_mq_map_swqueue(q);
26a9750a 4248 return 0;
18741986 4249
320ae51f 4250err_hctxs:
943f45b9 4251 blk_mq_release(q);
c7de5726
ML
4252err_exit:
4253 q->mq_ops = NULL;
26a9750a 4254 return -ENOMEM;
320ae51f 4255}
b62c21b7 4256EXPORT_SYMBOL(blk_mq_init_allocated_queue);
320ae51f 4257
c7e2d94b
ML
4258/* tags can _not_ be used after returning from blk_mq_exit_queue */
4259void blk_mq_exit_queue(struct request_queue *q)
320ae51f 4260{
630ef623 4261 struct blk_mq_tag_set *set = q->tag_set;
320ae51f 4262
630ef623 4263 /* Checks hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED. */
624dbe47 4264 blk_mq_exit_hw_queues(q, set, set->nr_hw_queues);
630ef623
BVA
4265 /* May clear BLK_MQ_F_TAG_QUEUE_SHARED in hctx->flags. */
4266 blk_mq_del_queue_tag_set(q);
320ae51f 4267}
320ae51f 4268
a5164405
JA
4269static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
4270{
4271 int i;
4272
079a2e3e
JG
4273 if (blk_mq_is_shared_tags(set->flags)) {
4274 set->shared_tags = blk_mq_alloc_map_and_rqs(set,
e155b0c2
JG
4275 BLK_MQ_NO_HCTX_IDX,
4276 set->queue_depth);
079a2e3e 4277 if (!set->shared_tags)
e155b0c2
JG
4278 return -ENOMEM;
4279 }
4280
8229cca8 4281 for (i = 0; i < set->nr_hw_queues; i++) {
63064be1 4282 if (!__blk_mq_alloc_map_and_rqs(set, i))
a5164405 4283 goto out_unwind;
8229cca8
XT
4284 cond_resched();
4285 }
a5164405
JA
4286
4287 return 0;
4288
4289out_unwind:
4290 while (--i >= 0)
e155b0c2
JG
4291 __blk_mq_free_map_and_rqs(set, i);
4292
079a2e3e
JG
4293 if (blk_mq_is_shared_tags(set->flags)) {
4294 blk_mq_free_map_and_rqs(set, set->shared_tags,
e155b0c2 4295 BLK_MQ_NO_HCTX_IDX);
645db34e 4296 }
a5164405 4297
a5164405
JA
4298 return -ENOMEM;
4299}
4300
4301/*
4302 * Allocate the request maps associated with this tag_set. Note that this
4303 * may reduce the depth asked for, if memory is tight. set->queue_depth
4304 * will be updated to reflect the allocated depth.
4305 */
63064be1 4306static int blk_mq_alloc_set_map_and_rqs(struct blk_mq_tag_set *set)
a5164405
JA
4307{
4308 unsigned int depth;
4309 int err;
4310
4311 depth = set->queue_depth;
4312 do {
4313 err = __blk_mq_alloc_rq_maps(set);
4314 if (!err)
4315 break;
4316
4317 set->queue_depth >>= 1;
4318 if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) {
4319 err = -ENOMEM;
4320 break;
4321 }
4322 } while (set->queue_depth);
4323
4324 if (!set->queue_depth || err) {
4325 pr_err("blk-mq: failed to allocate request map\n");
4326 return -ENOMEM;
4327 }
4328
4329 if (depth != set->queue_depth)
4330 pr_info("blk-mq: reduced tag depth (%u -> %u)\n",
4331 depth, set->queue_depth);
4332
4333 return 0;
4334}
4335
a4e1d0b7 4336static void blk_mq_update_queue_map(struct blk_mq_tag_set *set)
ebe8bddb 4337{
6e66b493
BVA
4338 /*
4339 * blk_mq_map_queues() and multiple .map_queues() implementations
4340 * expect that set->map[HCTX_TYPE_DEFAULT].nr_queues is set to the
4341 * number of hardware queues.
4342 */
4343 if (set->nr_maps == 1)
4344 set->map[HCTX_TYPE_DEFAULT].nr_queues = set->nr_hw_queues;
4345
59388702 4346 if (set->ops->map_queues && !is_kdump_kernel()) {
b3c661b1
JA
4347 int i;
4348
7d4901a9
ML
4349 /*
4350 * transport .map_queues is usually done in the following
4351 * way:
4352 *
4353 * for (queue = 0; queue < set->nr_hw_queues; queue++) {
4354 * mask = get_cpu_mask(queue)
4355 * for_each_cpu(cpu, mask)
b3c661b1 4356 * set->map[x].mq_map[cpu] = queue;
7d4901a9
ML
4357 * }
4358 *
4359 * When we need to remap, the table has to be cleared for
4360 * killing stale mapping since one CPU may not be mapped
4361 * to any hw queue.
4362 */
b3c661b1
JA
4363 for (i = 0; i < set->nr_maps; i++)
4364 blk_mq_clear_mq_map(&set->map[i]);
7d4901a9 4365
a4e1d0b7 4366 set->ops->map_queues(set);
b3c661b1
JA
4367 } else {
4368 BUG_ON(set->nr_maps > 1);
a4e1d0b7 4369 blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]);
b3c661b1 4370 }
ebe8bddb
OS
4371}
4372
f7e76dbc 4373static int blk_mq_realloc_tag_set_tags(struct blk_mq_tag_set *set,
ee9d5521 4374 int new_nr_hw_queues)
f7e76dbc
BVA
4375{
4376 struct blk_mq_tags **new_tags;
4377
ee9d5521 4378 if (set->nr_hw_queues >= new_nr_hw_queues)
d4b2e0d4 4379 goto done;
f7e76dbc
BVA
4380
4381 new_tags = kcalloc_node(new_nr_hw_queues, sizeof(struct blk_mq_tags *),
4382 GFP_KERNEL, set->numa_node);
4383 if (!new_tags)
4384 return -ENOMEM;
4385
4386 if (set->tags)
ee9d5521 4387 memcpy(new_tags, set->tags, set->nr_hw_queues *
f7e76dbc
BVA
4388 sizeof(*set->tags));
4389 kfree(set->tags);
4390 set->tags = new_tags;
d4b2e0d4 4391done:
f7e76dbc 4392 set->nr_hw_queues = new_nr_hw_queues;
f7e76dbc
BVA
4393 return 0;
4394}
4395
a4391c64
JA
4396/*
4397 * Alloc a tag set to be associated with one or more request queues.
4398 * May fail with EINVAL for various error conditions. May adjust the
c018c84f 4399 * requested depth down, if it's too large. In that case, the set
a4391c64
JA
4400 * value will be stored in set->queue_depth.
4401 */
24d2f903
CH
4402int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
4403{
b3c661b1 4404 int i, ret;
da695ba2 4405
205fb5f5
BVA
4406 BUILD_BUG_ON(BLK_MQ_MAX_DEPTH > 1 << BLK_MQ_UNIQUE_TAG_BITS);
4407
24d2f903
CH
4408 if (!set->nr_hw_queues)
4409 return -EINVAL;
a4391c64 4410 if (!set->queue_depth)
24d2f903
CH
4411 return -EINVAL;
4412 if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN)
4413 return -EINVAL;
4414
7d7e0f90 4415 if (!set->ops->queue_rq)
24d2f903
CH
4416 return -EINVAL;
4417
de148297
ML
4418 if (!set->ops->get_budget ^ !set->ops->put_budget)
4419 return -EINVAL;
4420
a4391c64
JA
4421 if (set->queue_depth > BLK_MQ_MAX_DEPTH) {
4422 pr_info("blk-mq: reduced tag depth to %u\n",
4423 BLK_MQ_MAX_DEPTH);
4424 set->queue_depth = BLK_MQ_MAX_DEPTH;
4425 }
24d2f903 4426
b3c661b1
JA
4427 if (!set->nr_maps)
4428 set->nr_maps = 1;
4429 else if (set->nr_maps > HCTX_MAX_TYPES)
4430 return -EINVAL;
4431
6637fadf
SL
4432 /*
4433 * If a crashdump is active, then we are potentially in a very
4434 * memory constrained environment. Limit us to 1 queue and
4435 * 64 tags to prevent using too much memory.
4436 */
4437 if (is_kdump_kernel()) {
4438 set->nr_hw_queues = 1;
59388702 4439 set->nr_maps = 1;
6637fadf
SL
4440 set->queue_depth = min(64U, set->queue_depth);
4441 }
868f2f0b 4442 /*
392546ae
JA
4443 * There is no use for more h/w queues than cpus if we just have
4444 * a single map
868f2f0b 4445 */
392546ae 4446 if (set->nr_maps == 1 && set->nr_hw_queues > nr_cpu_ids)
868f2f0b 4447 set->nr_hw_queues = nr_cpu_ids;
6637fadf 4448
80bd4a7a
CH
4449 if (set->flags & BLK_MQ_F_BLOCKING) {
4450 set->srcu = kmalloc(sizeof(*set->srcu), GFP_KERNEL);
4451 if (!set->srcu)
4452 return -ENOMEM;
4453 ret = init_srcu_struct(set->srcu);
4454 if (ret)
4455 goto out_free_srcu;
4456 }
24d2f903 4457
da695ba2 4458 ret = -ENOMEM;
5ee20298
CH
4459 set->tags = kcalloc_node(set->nr_hw_queues,
4460 sizeof(struct blk_mq_tags *), GFP_KERNEL,
4461 set->numa_node);
4462 if (!set->tags)
80bd4a7a 4463 goto out_cleanup_srcu;
24d2f903 4464
b3c661b1
JA
4465 for (i = 0; i < set->nr_maps; i++) {
4466 set->map[i].mq_map = kcalloc_node(nr_cpu_ids,
07b35eb5 4467 sizeof(set->map[i].mq_map[0]),
b3c661b1
JA
4468 GFP_KERNEL, set->numa_node);
4469 if (!set->map[i].mq_map)
4470 goto out_free_mq_map;
59388702 4471 set->map[i].nr_queues = is_kdump_kernel() ? 1 : set->nr_hw_queues;
b3c661b1 4472 }
bdd17e75 4473
a4e1d0b7 4474 blk_mq_update_queue_map(set);
da695ba2 4475
63064be1 4476 ret = blk_mq_alloc_set_map_and_rqs(set);
da695ba2 4477 if (ret)
bdd17e75 4478 goto out_free_mq_map;
24d2f903 4479
0d2602ca
JA
4480 mutex_init(&set->tag_list_lock);
4481 INIT_LIST_HEAD(&set->tag_list);
4482
24d2f903 4483 return 0;
bdd17e75
CH
4484
4485out_free_mq_map:
b3c661b1
JA
4486 for (i = 0; i < set->nr_maps; i++) {
4487 kfree(set->map[i].mq_map);
4488 set->map[i].mq_map = NULL;
4489 }
5676e7b6
RE
4490 kfree(set->tags);
4491 set->tags = NULL;
80bd4a7a
CH
4492out_cleanup_srcu:
4493 if (set->flags & BLK_MQ_F_BLOCKING)
4494 cleanup_srcu_struct(set->srcu);
4495out_free_srcu:
4496 if (set->flags & BLK_MQ_F_BLOCKING)
4497 kfree(set->srcu);
da695ba2 4498 return ret;
24d2f903
CH
4499}
4500EXPORT_SYMBOL(blk_mq_alloc_tag_set);
4501
cdb14e0f
CH
4502/* allocate and initialize a tagset for a simple single-queue device */
4503int blk_mq_alloc_sq_tag_set(struct blk_mq_tag_set *set,
4504 const struct blk_mq_ops *ops, unsigned int queue_depth,
4505 unsigned int set_flags)
4506{
4507 memset(set, 0, sizeof(*set));
4508 set->ops = ops;
4509 set->nr_hw_queues = 1;
4510 set->nr_maps = 1;
4511 set->queue_depth = queue_depth;
4512 set->numa_node = NUMA_NO_NODE;
4513 set->flags = set_flags;
4514 return blk_mq_alloc_tag_set(set);
4515}
4516EXPORT_SYMBOL_GPL(blk_mq_alloc_sq_tag_set);
4517
24d2f903
CH
4518void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
4519{
b3c661b1 4520 int i, j;
24d2f903 4521
f7e76dbc 4522 for (i = 0; i < set->nr_hw_queues; i++)
e155b0c2 4523 __blk_mq_free_map_and_rqs(set, i);
484b4061 4524
079a2e3e
JG
4525 if (blk_mq_is_shared_tags(set->flags)) {
4526 blk_mq_free_map_and_rqs(set, set->shared_tags,
e155b0c2
JG
4527 BLK_MQ_NO_HCTX_IDX);
4528 }
32bc15af 4529
b3c661b1
JA
4530 for (j = 0; j < set->nr_maps; j++) {
4531 kfree(set->map[j].mq_map);
4532 set->map[j].mq_map = NULL;
4533 }
bdd17e75 4534
981bd189 4535 kfree(set->tags);
5676e7b6 4536 set->tags = NULL;
80bd4a7a
CH
4537 if (set->flags & BLK_MQ_F_BLOCKING) {
4538 cleanup_srcu_struct(set->srcu);
4539 kfree(set->srcu);
4540 }
24d2f903
CH
4541}
4542EXPORT_SYMBOL(blk_mq_free_tag_set);
4543
e3a2b3f9
JA
4544int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
4545{
4546 struct blk_mq_tag_set *set = q->tag_set;
4547 struct blk_mq_hw_ctx *hctx;
4f481208
ML
4548 int ret;
4549 unsigned long i;
e3a2b3f9 4550
bd166ef1 4551 if (!set)
e3a2b3f9
JA
4552 return -EINVAL;
4553
e5fa8140
AZ
4554 if (q->nr_requests == nr)
4555 return 0;
4556
70f36b60 4557 blk_mq_freeze_queue(q);
24f5a90f 4558 blk_mq_quiesce_queue(q);
70f36b60 4559
e3a2b3f9
JA
4560 ret = 0;
4561 queue_for_each_hw_ctx(q, hctx, i) {
e9137d4b
KB
4562 if (!hctx->tags)
4563 continue;
bd166ef1
JA
4564 /*
4565 * If we're using an MQ scheduler, just update the scheduler
4566 * queue depth. This is similar to what the old code would do.
4567 */
f6adcef5 4568 if (hctx->sched_tags) {
70f36b60 4569 ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags,
f6adcef5 4570 nr, true);
f6adcef5
JG
4571 } else {
4572 ret = blk_mq_tag_update_depth(hctx, &hctx->tags, nr,
4573 false);
70f36b60 4574 }
e3a2b3f9
JA
4575 if (ret)
4576 break;
77f1e0a5
JA
4577 if (q->elevator && q->elevator->type->ops.depth_updated)
4578 q->elevator->type->ops.depth_updated(hctx);
e3a2b3f9 4579 }
d97e594c 4580 if (!ret) {
e3a2b3f9 4581 q->nr_requests = nr;
079a2e3e 4582 if (blk_mq_is_shared_tags(set->flags)) {
8fa04464 4583 if (q->elevator)
079a2e3e 4584 blk_mq_tag_update_sched_shared_tags(q);
8fa04464 4585 else
079a2e3e 4586 blk_mq_tag_resize_shared_tags(set, nr);
8fa04464 4587 }
d97e594c 4588 }
e3a2b3f9 4589
24f5a90f 4590 blk_mq_unquiesce_queue(q);
70f36b60 4591 blk_mq_unfreeze_queue(q);
70f36b60 4592
e3a2b3f9
JA
4593 return ret;
4594}
4595
d48ece20
JW
4596/*
4597 * request_queue and elevator_type pair.
4598 * It is just used by __blk_mq_update_nr_hw_queues to cache
4599 * the elevator_type associated with a request_queue.
4600 */
4601struct blk_mq_qe_pair {
4602 struct list_head node;
4603 struct request_queue *q;
4604 struct elevator_type *type;
4605};
4606
4607/*
4608 * Cache the elevator_type in qe pair list and switch the
4609 * io scheduler to 'none'
4610 */
4611static bool blk_mq_elv_switch_none(struct list_head *head,
4612 struct request_queue *q)
4613{
4614 struct blk_mq_qe_pair *qe;
4615
d48ece20
JW
4616 qe = kmalloc(sizeof(*qe), GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY);
4617 if (!qe)
4618 return false;
4619
5fd7a84a
ML
4620 /* q->elevator needs protection from ->sysfs_lock */
4621 mutex_lock(&q->sysfs_lock);
4622
24516565
ML
4623 /* the check has to be done with holding sysfs_lock */
4624 if (!q->elevator) {
4625 kfree(qe);
4626 goto unlock;
4627 }
4628
d48ece20
JW
4629 INIT_LIST_HEAD(&qe->node);
4630 qe->q = q;
4631 qe->type = q->elevator->type;
dd6f7f17
CH
4632 /* keep a reference to the elevator module as we'll switch back */
4633 __elevator_get(qe->type);
d48ece20 4634 list_add(&qe->node, head);
64b36075 4635 elevator_disable(q);
24516565 4636unlock:
d48ece20
JW
4637 mutex_unlock(&q->sysfs_lock);
4638
4639 return true;
4640}
4641
4a3b666e
JK
4642static struct blk_mq_qe_pair *blk_lookup_qe_pair(struct list_head *head,
4643 struct request_queue *q)
d48ece20
JW
4644{
4645 struct blk_mq_qe_pair *qe;
d48ece20
JW
4646
4647 list_for_each_entry(qe, head, node)
4a3b666e
JK
4648 if (qe->q == q)
4649 return qe;
d48ece20 4650
4a3b666e
JK
4651 return NULL;
4652}
d48ece20 4653
4a3b666e
JK
4654static void blk_mq_elv_switch_back(struct list_head *head,
4655 struct request_queue *q)
4656{
4657 struct blk_mq_qe_pair *qe;
4658 struct elevator_type *t;
4659
4660 qe = blk_lookup_qe_pair(head, q);
4661 if (!qe)
4662 return;
4663 t = qe->type;
d48ece20
JW
4664 list_del(&qe->node);
4665 kfree(qe);
4666
4667 mutex_lock(&q->sysfs_lock);
8237c01f 4668 elevator_switch(q, t);
8ed40ee3
JC
4669 /* drop the reference acquired in blk_mq_elv_switch_none */
4670 elevator_put(t);
d48ece20
JW
4671 mutex_unlock(&q->sysfs_lock);
4672}
4673
e4dc2b32
KB
4674static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set,
4675 int nr_hw_queues)
868f2f0b
KB
4676{
4677 struct request_queue *q;
d48ece20 4678 LIST_HEAD(head);
e01ad46d 4679 int prev_nr_hw_queues;
868f2f0b 4680
705cda97
BVA
4681 lockdep_assert_held(&set->tag_list_lock);
4682
392546ae 4683 if (set->nr_maps == 1 && nr_hw_queues > nr_cpu_ids)
868f2f0b 4684 nr_hw_queues = nr_cpu_ids;
fe35ec58
WZ
4685 if (nr_hw_queues < 1)
4686 return;
4687 if (set->nr_maps == 1 && nr_hw_queues == set->nr_hw_queues)
868f2f0b
KB
4688 return;
4689
4690 list_for_each_entry(q, &set->tag_list, tag_set_list)
4691 blk_mq_freeze_queue(q);
d48ece20
JW
4692 /*
4693 * Switch IO scheduler to 'none', cleaning up the data associated
4694 * with the previous scheduler. We will switch back once we are done
4695 * updating the new sw to hw queue mappings.
4696 */
4697 list_for_each_entry(q, &set->tag_list, tag_set_list)
4698 if (!blk_mq_elv_switch_none(&head, q))
4699 goto switch_back;
868f2f0b 4700
477e19de
JW
4701 list_for_each_entry(q, &set->tag_list, tag_set_list) {
4702 blk_mq_debugfs_unregister_hctxs(q);
eaa870f9 4703 blk_mq_sysfs_unregister_hctxs(q);
477e19de
JW
4704 }
4705
a2584e43 4706 prev_nr_hw_queues = set->nr_hw_queues;
ee9d5521 4707 if (blk_mq_realloc_tag_set_tags(set, nr_hw_queues) < 0)
f7e76dbc
BVA
4708 goto reregister;
4709
e01ad46d 4710fallback:
aa880ad6 4711 blk_mq_update_queue_map(set);
868f2f0b
KB
4712 list_for_each_entry(q, &set->tag_list, tag_set_list) {
4713 blk_mq_realloc_hw_ctxs(set, q);
42ee3061 4714 blk_mq_update_poll_flag(q);
e01ad46d 4715 if (q->nr_hw_queues != set->nr_hw_queues) {
a846a8e6
YB
4716 int i = prev_nr_hw_queues;
4717
e01ad46d
JW
4718 pr_warn("Increasing nr_hw_queues to %d fails, fallback to %d\n",
4719 nr_hw_queues, prev_nr_hw_queues);
a846a8e6
YB
4720 for (; i < set->nr_hw_queues; i++)
4721 __blk_mq_free_map_and_rqs(set, i);
4722
e01ad46d 4723 set->nr_hw_queues = prev_nr_hw_queues;
7d76f856 4724 blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]);
e01ad46d
JW
4725 goto fallback;
4726 }
477e19de
JW
4727 blk_mq_map_swqueue(q);
4728 }
4729
f7e76dbc 4730reregister:
477e19de 4731 list_for_each_entry(q, &set->tag_list, tag_set_list) {
eaa870f9 4732 blk_mq_sysfs_register_hctxs(q);
477e19de 4733 blk_mq_debugfs_register_hctxs(q);
868f2f0b
KB
4734 }
4735
d48ece20
JW
4736switch_back:
4737 list_for_each_entry(q, &set->tag_list, tag_set_list)
4738 blk_mq_elv_switch_back(&head, q);
4739
868f2f0b
KB
4740 list_for_each_entry(q, &set->tag_list, tag_set_list)
4741 blk_mq_unfreeze_queue(q);
4742}
e4dc2b32
KB
4743
4744void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues)
4745{
4746 mutex_lock(&set->tag_list_lock);
4747 __blk_mq_update_nr_hw_queues(set, nr_hw_queues);
4748 mutex_unlock(&set->tag_list_lock);
4749}
868f2f0b
KB
4750EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues);
4751
54bdd67d
KB
4752int blk_mq_poll(struct request_queue *q, blk_qc_t cookie, struct io_comp_batch *iob,
4753 unsigned int flags)
bbd7bb70 4754{
c6699d6f
CH
4755 struct blk_mq_hw_ctx *hctx = blk_qc_to_hctx(q, cookie);
4756 long state = get_current_state();
4757 int ret;
bbd7bb70 4758
aa61bec3 4759 do {
5a72e899 4760 ret = q->mq_ops->poll(hctx, iob);
bbd7bb70 4761 if (ret > 0) {
849a3700 4762 __set_current_state(TASK_RUNNING);
85f4d4b6 4763 return ret;
bbd7bb70
JA
4764 }
4765
4766 if (signal_pending_state(state, current))
849a3700 4767 __set_current_state(TASK_RUNNING);
b03fbd4f 4768 if (task_is_running(current))
85f4d4b6 4769 return 1;
c6699d6f 4770
ef99b2d3 4771 if (ret < 0 || (flags & BLK_POLL_ONESHOT))
bbd7bb70
JA
4772 break;
4773 cpu_relax();
aa61bec3 4774 } while (!need_resched());
bbd7bb70 4775
67b4110f 4776 __set_current_state(TASK_RUNNING);
85f4d4b6 4777 return 0;
bbd7bb70 4778}
1052b8ac 4779
9cf2bab6
JA
4780unsigned int blk_mq_rq_cpu(struct request *rq)
4781{
4782 return rq->mq_ctx->cpu;
4783}
4784EXPORT_SYMBOL(blk_mq_rq_cpu);
4785
2a19b28f
ML
4786void blk_mq_cancel_work_sync(struct request_queue *q)
4787{
219cf43c
JC
4788 struct blk_mq_hw_ctx *hctx;
4789 unsigned long i;
2a19b28f 4790
219cf43c 4791 cancel_delayed_work_sync(&q->requeue_work);
2a19b28f 4792
219cf43c
JC
4793 queue_for_each_hw_ctx(q, hctx, i)
4794 cancel_delayed_work_sync(&hctx->run_work);
2a19b28f
ML
4795}
4796
320ae51f
JA
4797static int __init blk_mq_init(void)
4798{
c3077b5d
CH
4799 int i;
4800
4801 for_each_possible_cpu(i)
f9ab4918 4802 init_llist_head(&per_cpu(blk_cpu_done, i));
c3077b5d
CH
4803 open_softirq(BLOCK_SOFTIRQ, blk_done_softirq);
4804
4805 cpuhp_setup_state_nocalls(CPUHP_BLOCK_SOFTIRQ_DEAD,
4806 "block/softirq:dead", NULL,
4807 blk_softirq_cpu_dead);
9467f859
TG
4808 cpuhp_setup_state_multi(CPUHP_BLK_MQ_DEAD, "block/mq:dead", NULL,
4809 blk_mq_hctx_notify_dead);
bf0beec0
ML
4810 cpuhp_setup_state_multi(CPUHP_AP_BLK_MQ_ONLINE, "block/mq:online",
4811 blk_mq_hctx_notify_online,
4812 blk_mq_hctx_notify_offline);
320ae51f
JA
4813 return 0;
4814}
4815subsys_initcall(blk_mq_init);