]>
Commit | Line | Data |
---|---|---|
75bb4625 JA |
1 | /* |
2 | * Block multiqueue core code | |
3 | * | |
4 | * Copyright (C) 2013-2014 Jens Axboe | |
5 | * Copyright (C) 2013-2014 Christoph Hellwig | |
6 | */ | |
320ae51f JA |
7 | #include <linux/kernel.h> |
8 | #include <linux/module.h> | |
9 | #include <linux/backing-dev.h> | |
10 | #include <linux/bio.h> | |
11 | #include <linux/blkdev.h> | |
f75782e4 | 12 | #include <linux/kmemleak.h> |
320ae51f JA |
13 | #include <linux/mm.h> |
14 | #include <linux/init.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/workqueue.h> | |
17 | #include <linux/smp.h> | |
18 | #include <linux/llist.h> | |
19 | #include <linux/list_sort.h> | |
20 | #include <linux/cpu.h> | |
21 | #include <linux/cache.h> | |
22 | #include <linux/sched/sysctl.h> | |
105ab3d8 | 23 | #include <linux/sched/topology.h> |
174cd4b1 | 24 | #include <linux/sched/signal.h> |
320ae51f | 25 | #include <linux/delay.h> |
aedcd72f | 26 | #include <linux/crash_dump.h> |
88c7b2b7 | 27 | #include <linux/prefetch.h> |
320ae51f JA |
28 | |
29 | #include <trace/events/block.h> | |
30 | ||
31 | #include <linux/blk-mq.h> | |
32 | #include "blk.h" | |
33 | #include "blk-mq.h" | |
9c1051aa | 34 | #include "blk-mq-debugfs.h" |
320ae51f | 35 | #include "blk-mq-tag.h" |
cf43e6be | 36 | #include "blk-stat.h" |
87760e5e | 37 | #include "blk-wbt.h" |
bd166ef1 | 38 | #include "blk-mq-sched.h" |
320ae51f JA |
39 | |
40 | static DEFINE_MUTEX(all_q_mutex); | |
41 | static LIST_HEAD(all_q_list); | |
42 | ||
34dbad5d OS |
43 | static void blk_mq_poll_stats_start(struct request_queue *q); |
44 | static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb); | |
2719aa21 | 45 | static void __blk_mq_stop_hw_queues(struct request_queue *q, bool sync); |
34dbad5d | 46 | |
720b8ccc SB |
47 | static int blk_mq_poll_stats_bkt(const struct request *rq) |
48 | { | |
49 | int ddir, bytes, bucket; | |
50 | ||
99c749a4 | 51 | ddir = rq_data_dir(rq); |
720b8ccc SB |
52 | bytes = blk_rq_bytes(rq); |
53 | ||
54 | bucket = ddir + 2*(ilog2(bytes) - 9); | |
55 | ||
56 | if (bucket < 0) | |
57 | return -1; | |
58 | else if (bucket >= BLK_MQ_POLL_STATS_BKTS) | |
59 | return ddir + BLK_MQ_POLL_STATS_BKTS - 2; | |
60 | ||
61 | return bucket; | |
62 | } | |
63 | ||
320ae51f JA |
64 | /* |
65 | * Check if any of the ctx's have pending work in this hardware queue | |
66 | */ | |
50e1dab8 | 67 | bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx) |
320ae51f | 68 | { |
bd166ef1 JA |
69 | return sbitmap_any_bit_set(&hctx->ctx_map) || |
70 | !list_empty_careful(&hctx->dispatch) || | |
71 | blk_mq_sched_has_work(hctx); | |
1429d7c9 JA |
72 | } |
73 | ||
320ae51f JA |
74 | /* |
75 | * Mark this ctx as having pending work in this hardware queue | |
76 | */ | |
77 | static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx, | |
78 | struct blk_mq_ctx *ctx) | |
79 | { | |
88459642 OS |
80 | if (!sbitmap_test_bit(&hctx->ctx_map, ctx->index_hw)) |
81 | sbitmap_set_bit(&hctx->ctx_map, ctx->index_hw); | |
1429d7c9 JA |
82 | } |
83 | ||
84 | static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx, | |
85 | struct blk_mq_ctx *ctx) | |
86 | { | |
88459642 | 87 | sbitmap_clear_bit(&hctx->ctx_map, ctx->index_hw); |
320ae51f JA |
88 | } |
89 | ||
1671d522 | 90 | void blk_freeze_queue_start(struct request_queue *q) |
43a5e4e2 | 91 | { |
4ecd4fef | 92 | int freeze_depth; |
cddd5d17 | 93 | |
4ecd4fef CH |
94 | freeze_depth = atomic_inc_return(&q->mq_freeze_depth); |
95 | if (freeze_depth == 1) { | |
3ef28e83 | 96 | percpu_ref_kill(&q->q_usage_counter); |
b94ec296 | 97 | blk_mq_run_hw_queues(q, false); |
cddd5d17 | 98 | } |
f3af020b | 99 | } |
1671d522 | 100 | EXPORT_SYMBOL_GPL(blk_freeze_queue_start); |
f3af020b | 101 | |
6bae363e | 102 | void blk_mq_freeze_queue_wait(struct request_queue *q) |
f3af020b | 103 | { |
3ef28e83 | 104 | wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter)); |
43a5e4e2 | 105 | } |
6bae363e | 106 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait); |
43a5e4e2 | 107 | |
f91328c4 KB |
108 | int blk_mq_freeze_queue_wait_timeout(struct request_queue *q, |
109 | unsigned long timeout) | |
110 | { | |
111 | return wait_event_timeout(q->mq_freeze_wq, | |
112 | percpu_ref_is_zero(&q->q_usage_counter), | |
113 | timeout); | |
114 | } | |
115 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait_timeout); | |
43a5e4e2 | 116 | |
f3af020b TH |
117 | /* |
118 | * Guarantee no request is in use, so we can change any data structure of | |
119 | * the queue afterward. | |
120 | */ | |
3ef28e83 | 121 | void blk_freeze_queue(struct request_queue *q) |
f3af020b | 122 | { |
3ef28e83 DW |
123 | /* |
124 | * In the !blk_mq case we are only calling this to kill the | |
125 | * q_usage_counter, otherwise this increases the freeze depth | |
126 | * and waits for it to return to zero. For this reason there is | |
127 | * no blk_unfreeze_queue(), and blk_freeze_queue() is not | |
128 | * exported to drivers as the only user for unfreeze is blk_mq. | |
129 | */ | |
1671d522 | 130 | blk_freeze_queue_start(q); |
f3af020b TH |
131 | blk_mq_freeze_queue_wait(q); |
132 | } | |
3ef28e83 DW |
133 | |
134 | void blk_mq_freeze_queue(struct request_queue *q) | |
135 | { | |
136 | /* | |
137 | * ...just an alias to keep freeze and unfreeze actions balanced | |
138 | * in the blk_mq_* namespace | |
139 | */ | |
140 | blk_freeze_queue(q); | |
141 | } | |
c761d96b | 142 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue); |
f3af020b | 143 | |
b4c6a028 | 144 | void blk_mq_unfreeze_queue(struct request_queue *q) |
320ae51f | 145 | { |
4ecd4fef | 146 | int freeze_depth; |
320ae51f | 147 | |
4ecd4fef CH |
148 | freeze_depth = atomic_dec_return(&q->mq_freeze_depth); |
149 | WARN_ON_ONCE(freeze_depth < 0); | |
150 | if (!freeze_depth) { | |
3ef28e83 | 151 | percpu_ref_reinit(&q->q_usage_counter); |
320ae51f | 152 | wake_up_all(&q->mq_freeze_wq); |
add703fd | 153 | } |
320ae51f | 154 | } |
b4c6a028 | 155 | EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue); |
320ae51f | 156 | |
6a83e74d BVA |
157 | /** |
158 | * blk_mq_quiesce_queue() - wait until all ongoing queue_rq calls have finished | |
159 | * @q: request queue. | |
160 | * | |
161 | * Note: this function does not prevent that the struct request end_io() | |
162 | * callback function is invoked. Additionally, it is not prevented that | |
163 | * new queue_rq() calls occur unless the queue has been stopped first. | |
164 | */ | |
165 | void blk_mq_quiesce_queue(struct request_queue *q) | |
166 | { | |
167 | struct blk_mq_hw_ctx *hctx; | |
168 | unsigned int i; | |
169 | bool rcu = false; | |
170 | ||
2719aa21 | 171 | __blk_mq_stop_hw_queues(q, true); |
6a83e74d BVA |
172 | |
173 | queue_for_each_hw_ctx(q, hctx, i) { | |
174 | if (hctx->flags & BLK_MQ_F_BLOCKING) | |
175 | synchronize_srcu(&hctx->queue_rq_srcu); | |
176 | else | |
177 | rcu = true; | |
178 | } | |
179 | if (rcu) | |
180 | synchronize_rcu(); | |
181 | } | |
182 | EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue); | |
183 | ||
aed3ea94 JA |
184 | void blk_mq_wake_waiters(struct request_queue *q) |
185 | { | |
186 | struct blk_mq_hw_ctx *hctx; | |
187 | unsigned int i; | |
188 | ||
189 | queue_for_each_hw_ctx(q, hctx, i) | |
190 | if (blk_mq_hw_queue_mapped(hctx)) | |
191 | blk_mq_tag_wakeup_all(hctx->tags, true); | |
3fd5940c KB |
192 | |
193 | /* | |
194 | * If we are called because the queue has now been marked as | |
195 | * dying, we need to ensure that processes currently waiting on | |
196 | * the queue are notified as well. | |
197 | */ | |
198 | wake_up_all(&q->mq_freeze_wq); | |
aed3ea94 JA |
199 | } |
200 | ||
320ae51f JA |
201 | bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx) |
202 | { | |
203 | return blk_mq_has_free_tags(hctx->tags); | |
204 | } | |
205 | EXPORT_SYMBOL(blk_mq_can_queue); | |
206 | ||
6e15cf2a CH |
207 | static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, |
208 | struct request *rq, unsigned int op) | |
320ae51f | 209 | { |
af76e555 CH |
210 | INIT_LIST_HEAD(&rq->queuelist); |
211 | /* csd/requeue_work/fifo_time is initialized before use */ | |
212 | rq->q = q; | |
320ae51f | 213 | rq->mq_ctx = ctx; |
ef295ecf | 214 | rq->cmd_flags = op; |
e8064021 CH |
215 | if (blk_queue_io_stat(q)) |
216 | rq->rq_flags |= RQF_IO_STAT; | |
af76e555 CH |
217 | /* do not touch atomic flags, it needs atomic ops against the timer */ |
218 | rq->cpu = -1; | |
af76e555 CH |
219 | INIT_HLIST_NODE(&rq->hash); |
220 | RB_CLEAR_NODE(&rq->rb_node); | |
af76e555 CH |
221 | rq->rq_disk = NULL; |
222 | rq->part = NULL; | |
3ee32372 | 223 | rq->start_time = jiffies; |
af76e555 CH |
224 | #ifdef CONFIG_BLK_CGROUP |
225 | rq->rl = NULL; | |
0fec08b4 | 226 | set_start_time_ns(rq); |
af76e555 CH |
227 | rq->io_start_time_ns = 0; |
228 | #endif | |
229 | rq->nr_phys_segments = 0; | |
230 | #if defined(CONFIG_BLK_DEV_INTEGRITY) | |
231 | rq->nr_integrity_segments = 0; | |
232 | #endif | |
af76e555 CH |
233 | rq->special = NULL; |
234 | /* tag was already set */ | |
af76e555 | 235 | rq->extra_len = 0; |
af76e555 | 236 | |
af76e555 | 237 | INIT_LIST_HEAD(&rq->timeout_list); |
f6be4fb4 JA |
238 | rq->timeout = 0; |
239 | ||
af76e555 CH |
240 | rq->end_io = NULL; |
241 | rq->end_io_data = NULL; | |
242 | rq->next_rq = NULL; | |
243 | ||
ef295ecf | 244 | ctx->rq_dispatched[op_is_sync(op)]++; |
320ae51f JA |
245 | } |
246 | ||
2c3ad667 JA |
247 | struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data, |
248 | unsigned int op) | |
5dee8577 CH |
249 | { |
250 | struct request *rq; | |
251 | unsigned int tag; | |
252 | ||
cb96a42c | 253 | tag = blk_mq_get_tag(data); |
5dee8577 | 254 | if (tag != BLK_MQ_TAG_FAIL) { |
bd166ef1 JA |
255 | struct blk_mq_tags *tags = blk_mq_tags_from_data(data); |
256 | ||
257 | rq = tags->static_rqs[tag]; | |
5dee8577 | 258 | |
bd166ef1 JA |
259 | if (data->flags & BLK_MQ_REQ_INTERNAL) { |
260 | rq->tag = -1; | |
261 | rq->internal_tag = tag; | |
262 | } else { | |
200e86b3 JA |
263 | if (blk_mq_tag_busy(data->hctx)) { |
264 | rq->rq_flags = RQF_MQ_INFLIGHT; | |
265 | atomic_inc(&data->hctx->nr_active); | |
266 | } | |
bd166ef1 JA |
267 | rq->tag = tag; |
268 | rq->internal_tag = -1; | |
562bef42 | 269 | data->hctx->tags->rqs[rq->tag] = rq; |
bd166ef1 JA |
270 | } |
271 | ||
ef295ecf | 272 | blk_mq_rq_ctx_init(data->q, data->ctx, rq, op); |
5dee8577 CH |
273 | return rq; |
274 | } | |
275 | ||
276 | return NULL; | |
277 | } | |
2c3ad667 | 278 | EXPORT_SYMBOL_GPL(__blk_mq_alloc_request); |
5dee8577 | 279 | |
d2c0d383 CH |
280 | static struct request *blk_mq_get_request(struct request_queue *q, |
281 | struct bio *bio, unsigned int op, | |
282 | struct blk_mq_alloc_data *data) | |
283 | { | |
284 | struct elevator_queue *e = q->elevator; | |
285 | struct request *rq; | |
286 | ||
287 | blk_queue_enter_live(q); | |
288 | data->q = q; | |
289 | if (likely(!data->ctx)) | |
290 | data->ctx = blk_mq_get_ctx(q); | |
291 | if (likely(!data->hctx)) | |
292 | data->hctx = blk_mq_map_queue(q, data->ctx->cpu); | |
293 | ||
294 | if (e) { | |
295 | data->flags |= BLK_MQ_REQ_INTERNAL; | |
296 | ||
297 | /* | |
298 | * Flush requests are special and go directly to the | |
299 | * dispatch list. | |
300 | */ | |
301 | if (!op_is_flush(op) && e->type->ops.mq.get_request) { | |
302 | rq = e->type->ops.mq.get_request(q, op, data); | |
303 | if (rq) | |
304 | rq->rq_flags |= RQF_QUEUED; | |
037cebb8 CH |
305 | goto allocated; |
306 | } | |
d2c0d383 CH |
307 | } |
308 | ||
037cebb8 CH |
309 | rq = __blk_mq_alloc_request(data, op); |
310 | allocated: | |
311 | if (!rq) { | |
312 | blk_queue_exit(q); | |
313 | return NULL; | |
d2c0d383 CH |
314 | } |
315 | ||
037cebb8 CH |
316 | if (!op_is_flush(op)) { |
317 | rq->elv.icq = NULL; | |
318 | if (e && e->type->icq_cache) | |
319 | blk_mq_sched_assign_ioc(q, rq, bio); | |
320 | } | |
321 | data->hctx->queued++; | |
322 | return rq; | |
d2c0d383 CH |
323 | } |
324 | ||
6f3b0e8b CH |
325 | struct request *blk_mq_alloc_request(struct request_queue *q, int rw, |
326 | unsigned int flags) | |
320ae51f | 327 | { |
5a797e00 | 328 | struct blk_mq_alloc_data alloc_data = { .flags = flags }; |
bd166ef1 | 329 | struct request *rq; |
a492f075 | 330 | int ret; |
320ae51f | 331 | |
6f3b0e8b | 332 | ret = blk_queue_enter(q, flags & BLK_MQ_REQ_NOWAIT); |
a492f075 JL |
333 | if (ret) |
334 | return ERR_PTR(ret); | |
320ae51f | 335 | |
d2c0d383 | 336 | rq = blk_mq_get_request(q, NULL, rw, &alloc_data); |
841bac2c | 337 | |
bd166ef1 JA |
338 | blk_mq_put_ctx(alloc_data.ctx); |
339 | blk_queue_exit(q); | |
340 | ||
341 | if (!rq) | |
a492f075 | 342 | return ERR_PTR(-EWOULDBLOCK); |
0c4de0f3 CH |
343 | |
344 | rq->__data_len = 0; | |
345 | rq->__sector = (sector_t) -1; | |
346 | rq->bio = rq->biotail = NULL; | |
320ae51f JA |
347 | return rq; |
348 | } | |
4bb659b1 | 349 | EXPORT_SYMBOL(blk_mq_alloc_request); |
320ae51f | 350 | |
1f5bd336 ML |
351 | struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int rw, |
352 | unsigned int flags, unsigned int hctx_idx) | |
353 | { | |
6d2809d5 | 354 | struct blk_mq_alloc_data alloc_data = { .flags = flags }; |
1f5bd336 | 355 | struct request *rq; |
6d2809d5 | 356 | unsigned int cpu; |
1f5bd336 ML |
357 | int ret; |
358 | ||
359 | /* | |
360 | * If the tag allocator sleeps we could get an allocation for a | |
361 | * different hardware context. No need to complicate the low level | |
362 | * allocator for this for the rare use case of a command tied to | |
363 | * a specific queue. | |
364 | */ | |
365 | if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT))) | |
366 | return ERR_PTR(-EINVAL); | |
367 | ||
368 | if (hctx_idx >= q->nr_hw_queues) | |
369 | return ERR_PTR(-EIO); | |
370 | ||
371 | ret = blk_queue_enter(q, true); | |
372 | if (ret) | |
373 | return ERR_PTR(ret); | |
374 | ||
c8712c6a CH |
375 | /* |
376 | * Check if the hardware context is actually mapped to anything. | |
377 | * If not tell the caller that it should skip this queue. | |
378 | */ | |
6d2809d5 OS |
379 | alloc_data.hctx = q->queue_hw_ctx[hctx_idx]; |
380 | if (!blk_mq_hw_queue_mapped(alloc_data.hctx)) { | |
381 | blk_queue_exit(q); | |
382 | return ERR_PTR(-EXDEV); | |
c8712c6a | 383 | } |
6d2809d5 OS |
384 | cpu = cpumask_first(alloc_data.hctx->cpumask); |
385 | alloc_data.ctx = __blk_mq_get_ctx(q, cpu); | |
1f5bd336 | 386 | |
d2c0d383 | 387 | rq = blk_mq_get_request(q, NULL, rw, &alloc_data); |
c8712c6a | 388 | |
c8712c6a | 389 | blk_queue_exit(q); |
6d2809d5 OS |
390 | |
391 | if (!rq) | |
392 | return ERR_PTR(-EWOULDBLOCK); | |
393 | ||
394 | return rq; | |
1f5bd336 ML |
395 | } |
396 | EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx); | |
397 | ||
6af54051 | 398 | void blk_mq_free_request(struct request *rq) |
320ae51f | 399 | { |
320ae51f | 400 | struct request_queue *q = rq->q; |
6af54051 CH |
401 | struct elevator_queue *e = q->elevator; |
402 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
403 | struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); | |
404 | const int sched_tag = rq->internal_tag; | |
405 | ||
406 | if (rq->rq_flags & (RQF_ELVPRIV | RQF_QUEUED)) { | |
407 | if (e && e->type->ops.mq.finish_request) | |
408 | e->type->ops.mq.finish_request(rq); | |
409 | if (rq->elv.icq) { | |
410 | put_io_context(rq->elv.icq->ioc); | |
411 | rq->elv.icq = NULL; | |
412 | } | |
413 | } | |
320ae51f | 414 | |
6af54051 | 415 | ctx->rq_completed[rq_is_sync(rq)]++; |
e8064021 | 416 | if (rq->rq_flags & RQF_MQ_INFLIGHT) |
0d2602ca | 417 | atomic_dec(&hctx->nr_active); |
87760e5e JA |
418 | |
419 | wbt_done(q->rq_wb, &rq->issue_stat); | |
e8064021 | 420 | rq->rq_flags = 0; |
0d2602ca | 421 | |
af76e555 | 422 | clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); |
06426adf | 423 | clear_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags); |
bd166ef1 JA |
424 | if (rq->tag != -1) |
425 | blk_mq_put_tag(hctx, hctx->tags, ctx, rq->tag); | |
426 | if (sched_tag != -1) | |
c05f8525 | 427 | blk_mq_put_tag(hctx, hctx->sched_tags, ctx, sched_tag); |
6d8c6c0f | 428 | blk_mq_sched_restart(hctx); |
3ef28e83 | 429 | blk_queue_exit(q); |
320ae51f | 430 | } |
1a3b595a | 431 | EXPORT_SYMBOL_GPL(blk_mq_free_request); |
320ae51f | 432 | |
2a842aca | 433 | inline void __blk_mq_end_request(struct request *rq, blk_status_t error) |
320ae51f | 434 | { |
0d11e6ac ML |
435 | blk_account_io_done(rq); |
436 | ||
91b63639 | 437 | if (rq->end_io) { |
87760e5e | 438 | wbt_done(rq->q->rq_wb, &rq->issue_stat); |
320ae51f | 439 | rq->end_io(rq, error); |
91b63639 CH |
440 | } else { |
441 | if (unlikely(blk_bidi_rq(rq))) | |
442 | blk_mq_free_request(rq->next_rq); | |
320ae51f | 443 | blk_mq_free_request(rq); |
91b63639 | 444 | } |
320ae51f | 445 | } |
c8a446ad | 446 | EXPORT_SYMBOL(__blk_mq_end_request); |
63151a44 | 447 | |
2a842aca | 448 | void blk_mq_end_request(struct request *rq, blk_status_t error) |
63151a44 CH |
449 | { |
450 | if (blk_update_request(rq, error, blk_rq_bytes(rq))) | |
451 | BUG(); | |
c8a446ad | 452 | __blk_mq_end_request(rq, error); |
63151a44 | 453 | } |
c8a446ad | 454 | EXPORT_SYMBOL(blk_mq_end_request); |
320ae51f | 455 | |
30a91cb4 | 456 | static void __blk_mq_complete_request_remote(void *data) |
320ae51f | 457 | { |
3d6efbf6 | 458 | struct request *rq = data; |
320ae51f | 459 | |
30a91cb4 | 460 | rq->q->softirq_done_fn(rq); |
320ae51f | 461 | } |
320ae51f | 462 | |
453f8341 | 463 | static void __blk_mq_complete_request(struct request *rq) |
320ae51f JA |
464 | { |
465 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
38535201 | 466 | bool shared = false; |
320ae51f JA |
467 | int cpu; |
468 | ||
453f8341 CH |
469 | if (rq->internal_tag != -1) |
470 | blk_mq_sched_completed_request(rq); | |
471 | if (rq->rq_flags & RQF_STATS) { | |
472 | blk_mq_poll_stats_start(rq->q); | |
473 | blk_stat_add(rq); | |
474 | } | |
475 | ||
38535201 | 476 | if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) { |
30a91cb4 CH |
477 | rq->q->softirq_done_fn(rq); |
478 | return; | |
479 | } | |
320ae51f JA |
480 | |
481 | cpu = get_cpu(); | |
38535201 CH |
482 | if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags)) |
483 | shared = cpus_share_cache(cpu, ctx->cpu); | |
484 | ||
485 | if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) { | |
30a91cb4 | 486 | rq->csd.func = __blk_mq_complete_request_remote; |
3d6efbf6 CH |
487 | rq->csd.info = rq; |
488 | rq->csd.flags = 0; | |
c46fff2a | 489 | smp_call_function_single_async(ctx->cpu, &rq->csd); |
3d6efbf6 | 490 | } else { |
30a91cb4 | 491 | rq->q->softirq_done_fn(rq); |
3d6efbf6 | 492 | } |
320ae51f JA |
493 | put_cpu(); |
494 | } | |
30a91cb4 CH |
495 | |
496 | /** | |
497 | * blk_mq_complete_request - end I/O on a request | |
498 | * @rq: the request being processed | |
499 | * | |
500 | * Description: | |
501 | * Ends all I/O on a request. It does not handle partial completions. | |
502 | * The actual completion happens out-of-order, through a IPI handler. | |
503 | **/ | |
08e0029a | 504 | void blk_mq_complete_request(struct request *rq) |
30a91cb4 | 505 | { |
95f09684 JA |
506 | struct request_queue *q = rq->q; |
507 | ||
508 | if (unlikely(blk_should_fake_timeout(q))) | |
30a91cb4 | 509 | return; |
08e0029a | 510 | if (!blk_mark_rq_complete(rq)) |
ed851860 | 511 | __blk_mq_complete_request(rq); |
30a91cb4 CH |
512 | } |
513 | EXPORT_SYMBOL(blk_mq_complete_request); | |
320ae51f | 514 | |
973c0191 KB |
515 | int blk_mq_request_started(struct request *rq) |
516 | { | |
517 | return test_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
518 | } | |
519 | EXPORT_SYMBOL_GPL(blk_mq_request_started); | |
520 | ||
e2490073 | 521 | void blk_mq_start_request(struct request *rq) |
320ae51f JA |
522 | { |
523 | struct request_queue *q = rq->q; | |
524 | ||
bd166ef1 JA |
525 | blk_mq_sched_started_request(rq); |
526 | ||
320ae51f JA |
527 | trace_block_rq_issue(q, rq); |
528 | ||
cf43e6be | 529 | if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags)) { |
88eeca49 | 530 | blk_stat_set_issue(&rq->issue_stat, blk_rq_sectors(rq)); |
cf43e6be | 531 | rq->rq_flags |= RQF_STATS; |
87760e5e | 532 | wbt_issue(q->rq_wb, &rq->issue_stat); |
cf43e6be JA |
533 | } |
534 | ||
2b8393b4 | 535 | blk_add_timer(rq); |
87ee7b11 | 536 | |
538b7534 JA |
537 | /* |
538 | * Ensure that ->deadline is visible before set the started | |
539 | * flag and clear the completed flag. | |
540 | */ | |
541 | smp_mb__before_atomic(); | |
542 | ||
87ee7b11 JA |
543 | /* |
544 | * Mark us as started and clear complete. Complete might have been | |
545 | * set if requeue raced with timeout, which then marked it as | |
546 | * complete. So be sure to clear complete again when we start | |
547 | * the request, otherwise we'll ignore the completion event. | |
548 | */ | |
4b570521 JA |
549 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) |
550 | set_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
551 | if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) | |
552 | clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); | |
49f5baa5 CH |
553 | |
554 | if (q->dma_drain_size && blk_rq_bytes(rq)) { | |
555 | /* | |
556 | * Make sure space for the drain appears. We know we can do | |
557 | * this because max_hw_segments has been adjusted to be one | |
558 | * fewer than the device can handle. | |
559 | */ | |
560 | rq->nr_phys_segments++; | |
561 | } | |
320ae51f | 562 | } |
e2490073 | 563 | EXPORT_SYMBOL(blk_mq_start_request); |
320ae51f | 564 | |
d9d149a3 ML |
565 | /* |
566 | * When we reach here because queue is busy, REQ_ATOM_COMPLETE | |
48b99c9d | 567 | * flag isn't set yet, so there may be race with timeout handler, |
d9d149a3 ML |
568 | * but given rq->deadline is just set in .queue_rq() under |
569 | * this situation, the race won't be possible in reality because | |
570 | * rq->timeout should be set as big enough to cover the window | |
571 | * between blk_mq_start_request() called from .queue_rq() and | |
572 | * clearing REQ_ATOM_STARTED here. | |
573 | */ | |
ed0791b2 | 574 | static void __blk_mq_requeue_request(struct request *rq) |
320ae51f JA |
575 | { |
576 | struct request_queue *q = rq->q; | |
577 | ||
578 | trace_block_rq_requeue(q, rq); | |
87760e5e | 579 | wbt_requeue(q->rq_wb, &rq->issue_stat); |
bd166ef1 | 580 | blk_mq_sched_requeue_request(rq); |
49f5baa5 | 581 | |
e2490073 CH |
582 | if (test_and_clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) { |
583 | if (q->dma_drain_size && blk_rq_bytes(rq)) | |
584 | rq->nr_phys_segments--; | |
585 | } | |
320ae51f JA |
586 | } |
587 | ||
2b053aca | 588 | void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list) |
ed0791b2 | 589 | { |
ed0791b2 | 590 | __blk_mq_requeue_request(rq); |
ed0791b2 | 591 | |
ed0791b2 | 592 | BUG_ON(blk_queued_rq(rq)); |
2b053aca | 593 | blk_mq_add_to_requeue_list(rq, true, kick_requeue_list); |
ed0791b2 CH |
594 | } |
595 | EXPORT_SYMBOL(blk_mq_requeue_request); | |
596 | ||
6fca6a61 CH |
597 | static void blk_mq_requeue_work(struct work_struct *work) |
598 | { | |
599 | struct request_queue *q = | |
2849450a | 600 | container_of(work, struct request_queue, requeue_work.work); |
6fca6a61 CH |
601 | LIST_HEAD(rq_list); |
602 | struct request *rq, *next; | |
603 | unsigned long flags; | |
604 | ||
605 | spin_lock_irqsave(&q->requeue_lock, flags); | |
606 | list_splice_init(&q->requeue_list, &rq_list); | |
607 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
608 | ||
609 | list_for_each_entry_safe(rq, next, &rq_list, queuelist) { | |
e8064021 | 610 | if (!(rq->rq_flags & RQF_SOFTBARRIER)) |
6fca6a61 CH |
611 | continue; |
612 | ||
e8064021 | 613 | rq->rq_flags &= ~RQF_SOFTBARRIER; |
6fca6a61 | 614 | list_del_init(&rq->queuelist); |
bd6737f1 | 615 | blk_mq_sched_insert_request(rq, true, false, false, true); |
6fca6a61 CH |
616 | } |
617 | ||
618 | while (!list_empty(&rq_list)) { | |
619 | rq = list_entry(rq_list.next, struct request, queuelist); | |
620 | list_del_init(&rq->queuelist); | |
bd6737f1 | 621 | blk_mq_sched_insert_request(rq, false, false, false, true); |
6fca6a61 CH |
622 | } |
623 | ||
52d7f1b5 | 624 | blk_mq_run_hw_queues(q, false); |
6fca6a61 CH |
625 | } |
626 | ||
2b053aca BVA |
627 | void blk_mq_add_to_requeue_list(struct request *rq, bool at_head, |
628 | bool kick_requeue_list) | |
6fca6a61 CH |
629 | { |
630 | struct request_queue *q = rq->q; | |
631 | unsigned long flags; | |
632 | ||
633 | /* | |
634 | * We abuse this flag that is otherwise used by the I/O scheduler to | |
635 | * request head insertation from the workqueue. | |
636 | */ | |
e8064021 | 637 | BUG_ON(rq->rq_flags & RQF_SOFTBARRIER); |
6fca6a61 CH |
638 | |
639 | spin_lock_irqsave(&q->requeue_lock, flags); | |
640 | if (at_head) { | |
e8064021 | 641 | rq->rq_flags |= RQF_SOFTBARRIER; |
6fca6a61 CH |
642 | list_add(&rq->queuelist, &q->requeue_list); |
643 | } else { | |
644 | list_add_tail(&rq->queuelist, &q->requeue_list); | |
645 | } | |
646 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
2b053aca BVA |
647 | |
648 | if (kick_requeue_list) | |
649 | blk_mq_kick_requeue_list(q); | |
6fca6a61 CH |
650 | } |
651 | EXPORT_SYMBOL(blk_mq_add_to_requeue_list); | |
652 | ||
653 | void blk_mq_kick_requeue_list(struct request_queue *q) | |
654 | { | |
2849450a | 655 | kblockd_schedule_delayed_work(&q->requeue_work, 0); |
6fca6a61 CH |
656 | } |
657 | EXPORT_SYMBOL(blk_mq_kick_requeue_list); | |
658 | ||
2849450a MS |
659 | void blk_mq_delay_kick_requeue_list(struct request_queue *q, |
660 | unsigned long msecs) | |
661 | { | |
662 | kblockd_schedule_delayed_work(&q->requeue_work, | |
663 | msecs_to_jiffies(msecs)); | |
664 | } | |
665 | EXPORT_SYMBOL(blk_mq_delay_kick_requeue_list); | |
666 | ||
0e62f51f JA |
667 | struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag) |
668 | { | |
88c7b2b7 JA |
669 | if (tag < tags->nr_tags) { |
670 | prefetch(tags->rqs[tag]); | |
4ee86bab | 671 | return tags->rqs[tag]; |
88c7b2b7 | 672 | } |
4ee86bab HR |
673 | |
674 | return NULL; | |
24d2f903 CH |
675 | } |
676 | EXPORT_SYMBOL(blk_mq_tag_to_rq); | |
677 | ||
320ae51f | 678 | struct blk_mq_timeout_data { |
46f92d42 CH |
679 | unsigned long next; |
680 | unsigned int next_set; | |
320ae51f JA |
681 | }; |
682 | ||
90415837 | 683 | void blk_mq_rq_timed_out(struct request *req, bool reserved) |
320ae51f | 684 | { |
f8a5b122 | 685 | const struct blk_mq_ops *ops = req->q->mq_ops; |
46f92d42 | 686 | enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER; |
87ee7b11 JA |
687 | |
688 | /* | |
689 | * We know that complete is set at this point. If STARTED isn't set | |
690 | * anymore, then the request isn't active and the "timeout" should | |
691 | * just be ignored. This can happen due to the bitflag ordering. | |
692 | * Timeout first checks if STARTED is set, and if it is, assumes | |
693 | * the request is active. But if we race with completion, then | |
48b99c9d | 694 | * both flags will get cleared. So check here again, and ignore |
87ee7b11 JA |
695 | * a timeout event with a request that isn't active. |
696 | */ | |
46f92d42 CH |
697 | if (!test_bit(REQ_ATOM_STARTED, &req->atomic_flags)) |
698 | return; | |
87ee7b11 | 699 | |
46f92d42 | 700 | if (ops->timeout) |
0152fb6b | 701 | ret = ops->timeout(req, reserved); |
46f92d42 CH |
702 | |
703 | switch (ret) { | |
704 | case BLK_EH_HANDLED: | |
705 | __blk_mq_complete_request(req); | |
706 | break; | |
707 | case BLK_EH_RESET_TIMER: | |
708 | blk_add_timer(req); | |
709 | blk_clear_rq_complete(req); | |
710 | break; | |
711 | case BLK_EH_NOT_HANDLED: | |
712 | break; | |
713 | default: | |
714 | printk(KERN_ERR "block: bad eh return: %d\n", ret); | |
715 | break; | |
716 | } | |
87ee7b11 | 717 | } |
5b3f25fc | 718 | |
81481eb4 CH |
719 | static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx, |
720 | struct request *rq, void *priv, bool reserved) | |
721 | { | |
722 | struct blk_mq_timeout_data *data = priv; | |
87ee7b11 | 723 | |
95a49603 | 724 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) |
46f92d42 | 725 | return; |
87ee7b11 | 726 | |
d9d149a3 ML |
727 | /* |
728 | * The rq being checked may have been freed and reallocated | |
729 | * out already here, we avoid this race by checking rq->deadline | |
730 | * and REQ_ATOM_COMPLETE flag together: | |
731 | * | |
732 | * - if rq->deadline is observed as new value because of | |
733 | * reusing, the rq won't be timed out because of timing. | |
734 | * - if rq->deadline is observed as previous value, | |
735 | * REQ_ATOM_COMPLETE flag won't be cleared in reuse path | |
736 | * because we put a barrier between setting rq->deadline | |
737 | * and clearing the flag in blk_mq_start_request(), so | |
738 | * this rq won't be timed out too. | |
739 | */ | |
46f92d42 CH |
740 | if (time_after_eq(jiffies, rq->deadline)) { |
741 | if (!blk_mark_rq_complete(rq)) | |
0152fb6b | 742 | blk_mq_rq_timed_out(rq, reserved); |
46f92d42 CH |
743 | } else if (!data->next_set || time_after(data->next, rq->deadline)) { |
744 | data->next = rq->deadline; | |
745 | data->next_set = 1; | |
746 | } | |
87ee7b11 JA |
747 | } |
748 | ||
287922eb | 749 | static void blk_mq_timeout_work(struct work_struct *work) |
320ae51f | 750 | { |
287922eb CH |
751 | struct request_queue *q = |
752 | container_of(work, struct request_queue, timeout_work); | |
81481eb4 CH |
753 | struct blk_mq_timeout_data data = { |
754 | .next = 0, | |
755 | .next_set = 0, | |
756 | }; | |
81481eb4 | 757 | int i; |
320ae51f | 758 | |
71f79fb3 GKB |
759 | /* A deadlock might occur if a request is stuck requiring a |
760 | * timeout at the same time a queue freeze is waiting | |
761 | * completion, since the timeout code would not be able to | |
762 | * acquire the queue reference here. | |
763 | * | |
764 | * That's why we don't use blk_queue_enter here; instead, we use | |
765 | * percpu_ref_tryget directly, because we need to be able to | |
766 | * obtain a reference even in the short window between the queue | |
767 | * starting to freeze, by dropping the first reference in | |
1671d522 | 768 | * blk_freeze_queue_start, and the moment the last request is |
71f79fb3 GKB |
769 | * consumed, marked by the instant q_usage_counter reaches |
770 | * zero. | |
771 | */ | |
772 | if (!percpu_ref_tryget(&q->q_usage_counter)) | |
287922eb CH |
773 | return; |
774 | ||
0bf6cd5b | 775 | blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &data); |
320ae51f | 776 | |
81481eb4 CH |
777 | if (data.next_set) { |
778 | data.next = blk_rq_timeout(round_jiffies_up(data.next)); | |
779 | mod_timer(&q->timeout, data.next); | |
0d2602ca | 780 | } else { |
0bf6cd5b CH |
781 | struct blk_mq_hw_ctx *hctx; |
782 | ||
f054b56c ML |
783 | queue_for_each_hw_ctx(q, hctx, i) { |
784 | /* the hctx may be unmapped, so check it here */ | |
785 | if (blk_mq_hw_queue_mapped(hctx)) | |
786 | blk_mq_tag_idle(hctx); | |
787 | } | |
0d2602ca | 788 | } |
287922eb | 789 | blk_queue_exit(q); |
320ae51f JA |
790 | } |
791 | ||
88459642 OS |
792 | struct flush_busy_ctx_data { |
793 | struct blk_mq_hw_ctx *hctx; | |
794 | struct list_head *list; | |
795 | }; | |
796 | ||
797 | static bool flush_busy_ctx(struct sbitmap *sb, unsigned int bitnr, void *data) | |
798 | { | |
799 | struct flush_busy_ctx_data *flush_data = data; | |
800 | struct blk_mq_hw_ctx *hctx = flush_data->hctx; | |
801 | struct blk_mq_ctx *ctx = hctx->ctxs[bitnr]; | |
802 | ||
803 | sbitmap_clear_bit(sb, bitnr); | |
804 | spin_lock(&ctx->lock); | |
805 | list_splice_tail_init(&ctx->rq_list, flush_data->list); | |
806 | spin_unlock(&ctx->lock); | |
807 | return true; | |
808 | } | |
809 | ||
1429d7c9 JA |
810 | /* |
811 | * Process software queues that have been marked busy, splicing them | |
812 | * to the for-dispatch | |
813 | */ | |
2c3ad667 | 814 | void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) |
1429d7c9 | 815 | { |
88459642 OS |
816 | struct flush_busy_ctx_data data = { |
817 | .hctx = hctx, | |
818 | .list = list, | |
819 | }; | |
1429d7c9 | 820 | |
88459642 | 821 | sbitmap_for_each_set(&hctx->ctx_map, flush_busy_ctx, &data); |
1429d7c9 | 822 | } |
2c3ad667 | 823 | EXPORT_SYMBOL_GPL(blk_mq_flush_busy_ctxs); |
1429d7c9 | 824 | |
703fd1c0 JA |
825 | static inline unsigned int queued_to_index(unsigned int queued) |
826 | { | |
827 | if (!queued) | |
828 | return 0; | |
1429d7c9 | 829 | |
703fd1c0 | 830 | return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1); |
1429d7c9 JA |
831 | } |
832 | ||
bd6737f1 JA |
833 | bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx, |
834 | bool wait) | |
bd166ef1 JA |
835 | { |
836 | struct blk_mq_alloc_data data = { | |
837 | .q = rq->q, | |
bd166ef1 JA |
838 | .hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu), |
839 | .flags = wait ? 0 : BLK_MQ_REQ_NOWAIT, | |
840 | }; | |
841 | ||
5feeacdd JA |
842 | might_sleep_if(wait); |
843 | ||
81380ca1 OS |
844 | if (rq->tag != -1) |
845 | goto done; | |
bd166ef1 | 846 | |
415b806d SG |
847 | if (blk_mq_tag_is_reserved(data.hctx->sched_tags, rq->internal_tag)) |
848 | data.flags |= BLK_MQ_REQ_RESERVED; | |
849 | ||
bd166ef1 JA |
850 | rq->tag = blk_mq_get_tag(&data); |
851 | if (rq->tag >= 0) { | |
200e86b3 JA |
852 | if (blk_mq_tag_busy(data.hctx)) { |
853 | rq->rq_flags |= RQF_MQ_INFLIGHT; | |
854 | atomic_inc(&data.hctx->nr_active); | |
855 | } | |
bd166ef1 | 856 | data.hctx->tags->rqs[rq->tag] = rq; |
bd166ef1 JA |
857 | } |
858 | ||
81380ca1 OS |
859 | done: |
860 | if (hctx) | |
861 | *hctx = data.hctx; | |
862 | return rq->tag != -1; | |
bd166ef1 JA |
863 | } |
864 | ||
113285b4 JA |
865 | static void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx, |
866 | struct request *rq) | |
99cf1dc5 | 867 | { |
99cf1dc5 JA |
868 | blk_mq_put_tag(hctx, hctx->tags, rq->mq_ctx, rq->tag); |
869 | rq->tag = -1; | |
870 | ||
871 | if (rq->rq_flags & RQF_MQ_INFLIGHT) { | |
872 | rq->rq_flags &= ~RQF_MQ_INFLIGHT; | |
873 | atomic_dec(&hctx->nr_active); | |
874 | } | |
875 | } | |
876 | ||
113285b4 JA |
877 | static void blk_mq_put_driver_tag_hctx(struct blk_mq_hw_ctx *hctx, |
878 | struct request *rq) | |
879 | { | |
880 | if (rq->tag == -1 || rq->internal_tag == -1) | |
881 | return; | |
882 | ||
883 | __blk_mq_put_driver_tag(hctx, rq); | |
884 | } | |
885 | ||
886 | static void blk_mq_put_driver_tag(struct request *rq) | |
887 | { | |
888 | struct blk_mq_hw_ctx *hctx; | |
889 | ||
890 | if (rq->tag == -1 || rq->internal_tag == -1) | |
891 | return; | |
892 | ||
893 | hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu); | |
894 | __blk_mq_put_driver_tag(hctx, rq); | |
895 | } | |
896 | ||
bd166ef1 JA |
897 | /* |
898 | * If we fail getting a driver tag because all the driver tags are already | |
899 | * assigned and on the dispatch list, BUT the first entry does not have a | |
900 | * tag, then we could deadlock. For that case, move entries with assigned | |
901 | * driver tags to the front, leaving the set of tagged requests in the | |
902 | * same order, and the untagged set in the same order. | |
903 | */ | |
904 | static bool reorder_tags_to_front(struct list_head *list) | |
905 | { | |
906 | struct request *rq, *tmp, *first = NULL; | |
907 | ||
908 | list_for_each_entry_safe_reverse(rq, tmp, list, queuelist) { | |
909 | if (rq == first) | |
910 | break; | |
911 | if (rq->tag != -1) { | |
912 | list_move(&rq->queuelist, list); | |
913 | if (!first) | |
914 | first = rq; | |
915 | } | |
916 | } | |
917 | ||
918 | return first != NULL; | |
919 | } | |
920 | ||
da55f2cc OS |
921 | static int blk_mq_dispatch_wake(wait_queue_t *wait, unsigned mode, int flags, |
922 | void *key) | |
923 | { | |
924 | struct blk_mq_hw_ctx *hctx; | |
925 | ||
926 | hctx = container_of(wait, struct blk_mq_hw_ctx, dispatch_wait); | |
927 | ||
928 | list_del(&wait->task_list); | |
929 | clear_bit_unlock(BLK_MQ_S_TAG_WAITING, &hctx->state); | |
930 | blk_mq_run_hw_queue(hctx, true); | |
931 | return 1; | |
932 | } | |
933 | ||
934 | static bool blk_mq_dispatch_wait_add(struct blk_mq_hw_ctx *hctx) | |
935 | { | |
936 | struct sbq_wait_state *ws; | |
937 | ||
938 | /* | |
939 | * The TAG_WAITING bit serves as a lock protecting hctx->dispatch_wait. | |
940 | * The thread which wins the race to grab this bit adds the hardware | |
941 | * queue to the wait queue. | |
942 | */ | |
943 | if (test_bit(BLK_MQ_S_TAG_WAITING, &hctx->state) || | |
944 | test_and_set_bit_lock(BLK_MQ_S_TAG_WAITING, &hctx->state)) | |
945 | return false; | |
946 | ||
947 | init_waitqueue_func_entry(&hctx->dispatch_wait, blk_mq_dispatch_wake); | |
948 | ws = bt_wait_ptr(&hctx->tags->bitmap_tags, hctx); | |
949 | ||
950 | /* | |
951 | * As soon as this returns, it's no longer safe to fiddle with | |
952 | * hctx->dispatch_wait, since a completion can wake up the wait queue | |
953 | * and unlock the bit. | |
954 | */ | |
955 | add_wait_queue(&ws->wait, &hctx->dispatch_wait); | |
956 | return true; | |
957 | } | |
958 | ||
81380ca1 | 959 | bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list) |
320ae51f | 960 | { |
81380ca1 | 961 | struct blk_mq_hw_ctx *hctx; |
320ae51f | 962 | struct request *rq; |
fc17b653 | 963 | int errors, queued; |
320ae51f | 964 | |
81380ca1 OS |
965 | if (list_empty(list)) |
966 | return false; | |
967 | ||
320ae51f JA |
968 | /* |
969 | * Now process all the entries, sending them to the driver. | |
970 | */ | |
93efe981 | 971 | errors = queued = 0; |
81380ca1 | 972 | do { |
74c45052 | 973 | struct blk_mq_queue_data bd; |
fc17b653 | 974 | blk_status_t ret; |
320ae51f | 975 | |
f04c3df3 | 976 | rq = list_first_entry(list, struct request, queuelist); |
bd166ef1 JA |
977 | if (!blk_mq_get_driver_tag(rq, &hctx, false)) { |
978 | if (!queued && reorder_tags_to_front(list)) | |
979 | continue; | |
3c782d67 JA |
980 | |
981 | /* | |
da55f2cc OS |
982 | * The initial allocation attempt failed, so we need to |
983 | * rerun the hardware queue when a tag is freed. | |
3c782d67 | 984 | */ |
807b1041 OS |
985 | if (!blk_mq_dispatch_wait_add(hctx)) |
986 | break; | |
987 | ||
988 | /* | |
989 | * It's possible that a tag was freed in the window | |
990 | * between the allocation failure and adding the | |
991 | * hardware queue to the wait queue. | |
992 | */ | |
993 | if (!blk_mq_get_driver_tag(rq, &hctx, false)) | |
3c782d67 | 994 | break; |
bd166ef1 | 995 | } |
da55f2cc | 996 | |
320ae51f | 997 | list_del_init(&rq->queuelist); |
320ae51f | 998 | |
74c45052 | 999 | bd.rq = rq; |
113285b4 JA |
1000 | |
1001 | /* | |
1002 | * Flag last if we have no more requests, or if we have more | |
1003 | * but can't assign a driver tag to it. | |
1004 | */ | |
1005 | if (list_empty(list)) | |
1006 | bd.last = true; | |
1007 | else { | |
1008 | struct request *nxt; | |
1009 | ||
1010 | nxt = list_first_entry(list, struct request, queuelist); | |
1011 | bd.last = !blk_mq_get_driver_tag(nxt, NULL, false); | |
1012 | } | |
74c45052 JA |
1013 | |
1014 | ret = q->mq_ops->queue_rq(hctx, &bd); | |
fc17b653 | 1015 | if (ret == BLK_STS_RESOURCE) { |
113285b4 | 1016 | blk_mq_put_driver_tag_hctx(hctx, rq); |
f04c3df3 | 1017 | list_add(&rq->queuelist, list); |
ed0791b2 | 1018 | __blk_mq_requeue_request(rq); |
320ae51f | 1019 | break; |
fc17b653 CH |
1020 | } |
1021 | ||
1022 | if (unlikely(ret != BLK_STS_OK)) { | |
93efe981 | 1023 | errors++; |
2a842aca | 1024 | blk_mq_end_request(rq, BLK_STS_IOERR); |
fc17b653 | 1025 | continue; |
320ae51f JA |
1026 | } |
1027 | ||
fc17b653 | 1028 | queued++; |
81380ca1 | 1029 | } while (!list_empty(list)); |
320ae51f | 1030 | |
703fd1c0 | 1031 | hctx->dispatched[queued_to_index(queued)]++; |
320ae51f JA |
1032 | |
1033 | /* | |
1034 | * Any items that need requeuing? Stuff them into hctx->dispatch, | |
1035 | * that is where we will continue on next queue run. | |
1036 | */ | |
f04c3df3 | 1037 | if (!list_empty(list)) { |
113285b4 | 1038 | /* |
710c785f BVA |
1039 | * If an I/O scheduler has been configured and we got a driver |
1040 | * tag for the next request already, free it again. | |
113285b4 JA |
1041 | */ |
1042 | rq = list_first_entry(list, struct request, queuelist); | |
1043 | blk_mq_put_driver_tag(rq); | |
1044 | ||
320ae51f | 1045 | spin_lock(&hctx->lock); |
c13660a0 | 1046 | list_splice_init(list, &hctx->dispatch); |
320ae51f | 1047 | spin_unlock(&hctx->lock); |
f04c3df3 | 1048 | |
9ba52e58 | 1049 | /* |
710c785f BVA |
1050 | * If SCHED_RESTART was set by the caller of this function and |
1051 | * it is no longer set that means that it was cleared by another | |
1052 | * thread and hence that a queue rerun is needed. | |
9ba52e58 | 1053 | * |
710c785f BVA |
1054 | * If TAG_WAITING is set that means that an I/O scheduler has |
1055 | * been configured and another thread is waiting for a driver | |
1056 | * tag. To guarantee fairness, do not rerun this hardware queue | |
1057 | * but let the other thread grab the driver tag. | |
bd166ef1 | 1058 | * |
710c785f BVA |
1059 | * If no I/O scheduler has been configured it is possible that |
1060 | * the hardware queue got stopped and restarted before requests | |
1061 | * were pushed back onto the dispatch list. Rerun the queue to | |
1062 | * avoid starvation. Notes: | |
1063 | * - blk_mq_run_hw_queue() checks whether or not a queue has | |
1064 | * been stopped before rerunning a queue. | |
1065 | * - Some but not all block drivers stop a queue before | |
fc17b653 | 1066 | * returning BLK_STS_RESOURCE. Two exceptions are scsi-mq |
710c785f | 1067 | * and dm-rq. |
bd166ef1 | 1068 | */ |
da55f2cc OS |
1069 | if (!blk_mq_sched_needs_restart(hctx) && |
1070 | !test_bit(BLK_MQ_S_TAG_WAITING, &hctx->state)) | |
bd166ef1 | 1071 | blk_mq_run_hw_queue(hctx, true); |
320ae51f | 1072 | } |
f04c3df3 | 1073 | |
93efe981 | 1074 | return (queued + errors) != 0; |
f04c3df3 JA |
1075 | } |
1076 | ||
6a83e74d BVA |
1077 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) |
1078 | { | |
1079 | int srcu_idx; | |
1080 | ||
1081 | WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) && | |
1082 | cpu_online(hctx->next_cpu)); | |
1083 | ||
1084 | if (!(hctx->flags & BLK_MQ_F_BLOCKING)) { | |
1085 | rcu_read_lock(); | |
bd166ef1 | 1086 | blk_mq_sched_dispatch_requests(hctx); |
6a83e74d BVA |
1087 | rcu_read_unlock(); |
1088 | } else { | |
bf4907c0 JA |
1089 | might_sleep(); |
1090 | ||
6a83e74d | 1091 | srcu_idx = srcu_read_lock(&hctx->queue_rq_srcu); |
bd166ef1 | 1092 | blk_mq_sched_dispatch_requests(hctx); |
6a83e74d BVA |
1093 | srcu_read_unlock(&hctx->queue_rq_srcu, srcu_idx); |
1094 | } | |
1095 | } | |
1096 | ||
506e931f JA |
1097 | /* |
1098 | * It'd be great if the workqueue API had a way to pass | |
1099 | * in a mask and had some smarts for more clever placement. | |
1100 | * For now we just round-robin here, switching for every | |
1101 | * BLK_MQ_CPU_WORK_BATCH queued items. | |
1102 | */ | |
1103 | static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) | |
1104 | { | |
b657d7e6 CH |
1105 | if (hctx->queue->nr_hw_queues == 1) |
1106 | return WORK_CPU_UNBOUND; | |
506e931f JA |
1107 | |
1108 | if (--hctx->next_cpu_batch <= 0) { | |
c02ebfdd | 1109 | int next_cpu; |
506e931f JA |
1110 | |
1111 | next_cpu = cpumask_next(hctx->next_cpu, hctx->cpumask); | |
1112 | if (next_cpu >= nr_cpu_ids) | |
1113 | next_cpu = cpumask_first(hctx->cpumask); | |
1114 | ||
1115 | hctx->next_cpu = next_cpu; | |
1116 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
1117 | } | |
1118 | ||
b657d7e6 | 1119 | return hctx->next_cpu; |
506e931f JA |
1120 | } |
1121 | ||
7587a5ae BVA |
1122 | static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async, |
1123 | unsigned long msecs) | |
320ae51f | 1124 | { |
5d1b25c1 BVA |
1125 | if (unlikely(blk_mq_hctx_stopped(hctx) || |
1126 | !blk_mq_hw_queue_mapped(hctx))) | |
320ae51f JA |
1127 | return; |
1128 | ||
1b792f2f | 1129 | if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) { |
2a90d4aa PB |
1130 | int cpu = get_cpu(); |
1131 | if (cpumask_test_cpu(cpu, hctx->cpumask)) { | |
398205b8 | 1132 | __blk_mq_run_hw_queue(hctx); |
2a90d4aa | 1133 | put_cpu(); |
398205b8 PB |
1134 | return; |
1135 | } | |
e4043dcf | 1136 | |
2a90d4aa | 1137 | put_cpu(); |
e4043dcf | 1138 | } |
398205b8 | 1139 | |
9f993737 JA |
1140 | kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx), |
1141 | &hctx->run_work, | |
1142 | msecs_to_jiffies(msecs)); | |
7587a5ae BVA |
1143 | } |
1144 | ||
1145 | void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) | |
1146 | { | |
1147 | __blk_mq_delay_run_hw_queue(hctx, true, msecs); | |
1148 | } | |
1149 | EXPORT_SYMBOL(blk_mq_delay_run_hw_queue); | |
1150 | ||
1151 | void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) | |
1152 | { | |
1153 | __blk_mq_delay_run_hw_queue(hctx, async, 0); | |
320ae51f | 1154 | } |
5b727272 | 1155 | EXPORT_SYMBOL(blk_mq_run_hw_queue); |
320ae51f | 1156 | |
b94ec296 | 1157 | void blk_mq_run_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
1158 | { |
1159 | struct blk_mq_hw_ctx *hctx; | |
1160 | int i; | |
1161 | ||
1162 | queue_for_each_hw_ctx(q, hctx, i) { | |
bd166ef1 | 1163 | if (!blk_mq_hctx_has_pending(hctx) || |
5d1b25c1 | 1164 | blk_mq_hctx_stopped(hctx)) |
320ae51f JA |
1165 | continue; |
1166 | ||
b94ec296 | 1167 | blk_mq_run_hw_queue(hctx, async); |
320ae51f JA |
1168 | } |
1169 | } | |
b94ec296 | 1170 | EXPORT_SYMBOL(blk_mq_run_hw_queues); |
320ae51f | 1171 | |
fd001443 BVA |
1172 | /** |
1173 | * blk_mq_queue_stopped() - check whether one or more hctxs have been stopped | |
1174 | * @q: request queue. | |
1175 | * | |
1176 | * The caller is responsible for serializing this function against | |
1177 | * blk_mq_{start,stop}_hw_queue(). | |
1178 | */ | |
1179 | bool blk_mq_queue_stopped(struct request_queue *q) | |
1180 | { | |
1181 | struct blk_mq_hw_ctx *hctx; | |
1182 | int i; | |
1183 | ||
1184 | queue_for_each_hw_ctx(q, hctx, i) | |
1185 | if (blk_mq_hctx_stopped(hctx)) | |
1186 | return true; | |
1187 | ||
1188 | return false; | |
1189 | } | |
1190 | EXPORT_SYMBOL(blk_mq_queue_stopped); | |
1191 | ||
2719aa21 | 1192 | static void __blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx, bool sync) |
320ae51f | 1193 | { |
2719aa21 JA |
1194 | if (sync) |
1195 | cancel_delayed_work_sync(&hctx->run_work); | |
1196 | else | |
1197 | cancel_delayed_work(&hctx->run_work); | |
1198 | ||
320ae51f JA |
1199 | set_bit(BLK_MQ_S_STOPPED, &hctx->state); |
1200 | } | |
2719aa21 JA |
1201 | |
1202 | void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx) | |
1203 | { | |
1204 | __blk_mq_stop_hw_queue(hctx, false); | |
1205 | } | |
320ae51f JA |
1206 | EXPORT_SYMBOL(blk_mq_stop_hw_queue); |
1207 | ||
ebd76857 | 1208 | static void __blk_mq_stop_hw_queues(struct request_queue *q, bool sync) |
280d45f6 CH |
1209 | { |
1210 | struct blk_mq_hw_ctx *hctx; | |
1211 | int i; | |
1212 | ||
1213 | queue_for_each_hw_ctx(q, hctx, i) | |
2719aa21 JA |
1214 | __blk_mq_stop_hw_queue(hctx, sync); |
1215 | } | |
1216 | ||
1217 | void blk_mq_stop_hw_queues(struct request_queue *q) | |
1218 | { | |
1219 | __blk_mq_stop_hw_queues(q, false); | |
280d45f6 CH |
1220 | } |
1221 | EXPORT_SYMBOL(blk_mq_stop_hw_queues); | |
1222 | ||
320ae51f JA |
1223 | void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx) |
1224 | { | |
1225 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
e4043dcf | 1226 | |
0ffbce80 | 1227 | blk_mq_run_hw_queue(hctx, false); |
320ae51f JA |
1228 | } |
1229 | EXPORT_SYMBOL(blk_mq_start_hw_queue); | |
1230 | ||
2f268556 CH |
1231 | void blk_mq_start_hw_queues(struct request_queue *q) |
1232 | { | |
1233 | struct blk_mq_hw_ctx *hctx; | |
1234 | int i; | |
1235 | ||
1236 | queue_for_each_hw_ctx(q, hctx, i) | |
1237 | blk_mq_start_hw_queue(hctx); | |
1238 | } | |
1239 | EXPORT_SYMBOL(blk_mq_start_hw_queues); | |
1240 | ||
ae911c5e JA |
1241 | void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
1242 | { | |
1243 | if (!blk_mq_hctx_stopped(hctx)) | |
1244 | return; | |
1245 | ||
1246 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
1247 | blk_mq_run_hw_queue(hctx, async); | |
1248 | } | |
1249 | EXPORT_SYMBOL_GPL(blk_mq_start_stopped_hw_queue); | |
1250 | ||
1b4a3258 | 1251 | void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
1252 | { |
1253 | struct blk_mq_hw_ctx *hctx; | |
1254 | int i; | |
1255 | ||
ae911c5e JA |
1256 | queue_for_each_hw_ctx(q, hctx, i) |
1257 | blk_mq_start_stopped_hw_queue(hctx, async); | |
320ae51f JA |
1258 | } |
1259 | EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); | |
1260 | ||
70f4db63 | 1261 | static void blk_mq_run_work_fn(struct work_struct *work) |
320ae51f JA |
1262 | { |
1263 | struct blk_mq_hw_ctx *hctx; | |
1264 | ||
9f993737 | 1265 | hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work); |
320ae51f | 1266 | |
21c6e939 JA |
1267 | /* |
1268 | * If we are stopped, don't run the queue. The exception is if | |
1269 | * BLK_MQ_S_START_ON_RUN is set. For that case, we auto-clear | |
1270 | * the STOPPED bit and run it. | |
1271 | */ | |
1272 | if (test_bit(BLK_MQ_S_STOPPED, &hctx->state)) { | |
1273 | if (!test_bit(BLK_MQ_S_START_ON_RUN, &hctx->state)) | |
1274 | return; | |
7587a5ae | 1275 | |
21c6e939 JA |
1276 | clear_bit(BLK_MQ_S_START_ON_RUN, &hctx->state); |
1277 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
1278 | } | |
7587a5ae BVA |
1279 | |
1280 | __blk_mq_run_hw_queue(hctx); | |
1281 | } | |
1282 | ||
70f4db63 CH |
1283 | |
1284 | void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) | |
1285 | { | |
19c66e59 ML |
1286 | if (unlikely(!blk_mq_hw_queue_mapped(hctx))) |
1287 | return; | |
70f4db63 | 1288 | |
21c6e939 JA |
1289 | /* |
1290 | * Stop the hw queue, then modify currently delayed work. | |
1291 | * This should prevent us from running the queue prematurely. | |
1292 | * Mark the queue as auto-clearing STOPPED when it runs. | |
1293 | */ | |
7e79dadc | 1294 | blk_mq_stop_hw_queue(hctx); |
21c6e939 JA |
1295 | set_bit(BLK_MQ_S_START_ON_RUN, &hctx->state); |
1296 | kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx), | |
1297 | &hctx->run_work, | |
1298 | msecs_to_jiffies(msecs)); | |
70f4db63 CH |
1299 | } |
1300 | EXPORT_SYMBOL(blk_mq_delay_queue); | |
1301 | ||
cfd0c552 | 1302 | static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx, |
cfd0c552 ML |
1303 | struct request *rq, |
1304 | bool at_head) | |
320ae51f | 1305 | { |
e57690fe JA |
1306 | struct blk_mq_ctx *ctx = rq->mq_ctx; |
1307 | ||
01b983c9 JA |
1308 | trace_block_rq_insert(hctx->queue, rq); |
1309 | ||
72a0a36e CH |
1310 | if (at_head) |
1311 | list_add(&rq->queuelist, &ctx->rq_list); | |
1312 | else | |
1313 | list_add_tail(&rq->queuelist, &ctx->rq_list); | |
cfd0c552 | 1314 | } |
4bb659b1 | 1315 | |
2c3ad667 JA |
1316 | void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, |
1317 | bool at_head) | |
cfd0c552 ML |
1318 | { |
1319 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
1320 | ||
e57690fe | 1321 | __blk_mq_insert_req_list(hctx, rq, at_head); |
320ae51f | 1322 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f JA |
1323 | } |
1324 | ||
bd166ef1 JA |
1325 | void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, |
1326 | struct list_head *list) | |
320ae51f JA |
1327 | |
1328 | { | |
320ae51f JA |
1329 | /* |
1330 | * preemption doesn't flush plug list, so it's possible ctx->cpu is | |
1331 | * offline now | |
1332 | */ | |
1333 | spin_lock(&ctx->lock); | |
1334 | while (!list_empty(list)) { | |
1335 | struct request *rq; | |
1336 | ||
1337 | rq = list_first_entry(list, struct request, queuelist); | |
e57690fe | 1338 | BUG_ON(rq->mq_ctx != ctx); |
320ae51f | 1339 | list_del_init(&rq->queuelist); |
e57690fe | 1340 | __blk_mq_insert_req_list(hctx, rq, false); |
320ae51f | 1341 | } |
cfd0c552 | 1342 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f | 1343 | spin_unlock(&ctx->lock); |
320ae51f JA |
1344 | } |
1345 | ||
1346 | static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b) | |
1347 | { | |
1348 | struct request *rqa = container_of(a, struct request, queuelist); | |
1349 | struct request *rqb = container_of(b, struct request, queuelist); | |
1350 | ||
1351 | return !(rqa->mq_ctx < rqb->mq_ctx || | |
1352 | (rqa->mq_ctx == rqb->mq_ctx && | |
1353 | blk_rq_pos(rqa) < blk_rq_pos(rqb))); | |
1354 | } | |
1355 | ||
1356 | void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) | |
1357 | { | |
1358 | struct blk_mq_ctx *this_ctx; | |
1359 | struct request_queue *this_q; | |
1360 | struct request *rq; | |
1361 | LIST_HEAD(list); | |
1362 | LIST_HEAD(ctx_list); | |
1363 | unsigned int depth; | |
1364 | ||
1365 | list_splice_init(&plug->mq_list, &list); | |
1366 | ||
1367 | list_sort(NULL, &list, plug_ctx_cmp); | |
1368 | ||
1369 | this_q = NULL; | |
1370 | this_ctx = NULL; | |
1371 | depth = 0; | |
1372 | ||
1373 | while (!list_empty(&list)) { | |
1374 | rq = list_entry_rq(list.next); | |
1375 | list_del_init(&rq->queuelist); | |
1376 | BUG_ON(!rq->q); | |
1377 | if (rq->mq_ctx != this_ctx) { | |
1378 | if (this_ctx) { | |
bd166ef1 JA |
1379 | trace_block_unplug(this_q, depth, from_schedule); |
1380 | blk_mq_sched_insert_requests(this_q, this_ctx, | |
1381 | &ctx_list, | |
1382 | from_schedule); | |
320ae51f JA |
1383 | } |
1384 | ||
1385 | this_ctx = rq->mq_ctx; | |
1386 | this_q = rq->q; | |
1387 | depth = 0; | |
1388 | } | |
1389 | ||
1390 | depth++; | |
1391 | list_add_tail(&rq->queuelist, &ctx_list); | |
1392 | } | |
1393 | ||
1394 | /* | |
1395 | * If 'this_ctx' is set, we know we have entries to complete | |
1396 | * on 'ctx_list'. Do those. | |
1397 | */ | |
1398 | if (this_ctx) { | |
bd166ef1 JA |
1399 | trace_block_unplug(this_q, depth, from_schedule); |
1400 | blk_mq_sched_insert_requests(this_q, this_ctx, &ctx_list, | |
1401 | from_schedule); | |
320ae51f JA |
1402 | } |
1403 | } | |
1404 | ||
1405 | static void blk_mq_bio_to_request(struct request *rq, struct bio *bio) | |
1406 | { | |
da8d7f07 | 1407 | blk_init_request_from_bio(rq, bio); |
4b570521 | 1408 | |
6e85eaf3 | 1409 | blk_account_io_start(rq, true); |
320ae51f JA |
1410 | } |
1411 | ||
274a5843 JA |
1412 | static inline bool hctx_allow_merges(struct blk_mq_hw_ctx *hctx) |
1413 | { | |
1414 | return (hctx->flags & BLK_MQ_F_SHOULD_MERGE) && | |
1415 | !blk_queue_nomerges(hctx->queue); | |
1416 | } | |
1417 | ||
ab42f35d ML |
1418 | static inline void blk_mq_queue_io(struct blk_mq_hw_ctx *hctx, |
1419 | struct blk_mq_ctx *ctx, | |
1420 | struct request *rq) | |
1421 | { | |
1422 | spin_lock(&ctx->lock); | |
1423 | __blk_mq_insert_request(hctx, rq, false); | |
1424 | spin_unlock(&ctx->lock); | |
07068d5b | 1425 | } |
14ec77f3 | 1426 | |
fd2d3326 JA |
1427 | static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq) |
1428 | { | |
bd166ef1 JA |
1429 | if (rq->tag != -1) |
1430 | return blk_tag_to_qc_t(rq->tag, hctx->queue_num, false); | |
1431 | ||
1432 | return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true); | |
fd2d3326 JA |
1433 | } |
1434 | ||
d964f04a ML |
1435 | static void __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, |
1436 | struct request *rq, | |
1437 | blk_qc_t *cookie, bool may_sleep) | |
f984df1f | 1438 | { |
f984df1f | 1439 | struct request_queue *q = rq->q; |
f984df1f SL |
1440 | struct blk_mq_queue_data bd = { |
1441 | .rq = rq, | |
d945a365 | 1442 | .last = true, |
f984df1f | 1443 | }; |
bd166ef1 | 1444 | blk_qc_t new_cookie; |
f06345ad | 1445 | blk_status_t ret; |
d964f04a ML |
1446 | bool run_queue = true; |
1447 | ||
1448 | if (blk_mq_hctx_stopped(hctx)) { | |
1449 | run_queue = false; | |
1450 | goto insert; | |
1451 | } | |
f984df1f | 1452 | |
bd166ef1 | 1453 | if (q->elevator) |
2253efc8 BVA |
1454 | goto insert; |
1455 | ||
d964f04a | 1456 | if (!blk_mq_get_driver_tag(rq, NULL, false)) |
bd166ef1 JA |
1457 | goto insert; |
1458 | ||
1459 | new_cookie = request_to_qc_t(hctx, rq); | |
1460 | ||
f984df1f SL |
1461 | /* |
1462 | * For OK queue, we are done. For error, kill it. Any other | |
1463 | * error (busy), just add it to our list as we previously | |
1464 | * would have done | |
1465 | */ | |
1466 | ret = q->mq_ops->queue_rq(hctx, &bd); | |
fc17b653 CH |
1467 | switch (ret) { |
1468 | case BLK_STS_OK: | |
7b371636 | 1469 | *cookie = new_cookie; |
2253efc8 | 1470 | return; |
fc17b653 CH |
1471 | case BLK_STS_RESOURCE: |
1472 | __blk_mq_requeue_request(rq); | |
1473 | goto insert; | |
1474 | default: | |
7b371636 | 1475 | *cookie = BLK_QC_T_NONE; |
fc17b653 | 1476 | blk_mq_end_request(rq, ret); |
2253efc8 | 1477 | return; |
f984df1f | 1478 | } |
7b371636 | 1479 | |
2253efc8 | 1480 | insert: |
d964f04a | 1481 | blk_mq_sched_insert_request(rq, false, run_queue, false, may_sleep); |
f984df1f SL |
1482 | } |
1483 | ||
5eb6126e CH |
1484 | static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, |
1485 | struct request *rq, blk_qc_t *cookie) | |
1486 | { | |
1487 | if (!(hctx->flags & BLK_MQ_F_BLOCKING)) { | |
1488 | rcu_read_lock(); | |
d964f04a | 1489 | __blk_mq_try_issue_directly(hctx, rq, cookie, false); |
5eb6126e CH |
1490 | rcu_read_unlock(); |
1491 | } else { | |
bf4907c0 JA |
1492 | unsigned int srcu_idx; |
1493 | ||
1494 | might_sleep(); | |
1495 | ||
1496 | srcu_idx = srcu_read_lock(&hctx->queue_rq_srcu); | |
d964f04a | 1497 | __blk_mq_try_issue_directly(hctx, rq, cookie, true); |
5eb6126e CH |
1498 | srcu_read_unlock(&hctx->queue_rq_srcu, srcu_idx); |
1499 | } | |
1500 | } | |
1501 | ||
dece1635 | 1502 | static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) |
07068d5b | 1503 | { |
ef295ecf | 1504 | const int is_sync = op_is_sync(bio->bi_opf); |
f73f44eb | 1505 | const int is_flush_fua = op_is_flush(bio->bi_opf); |
5a797e00 | 1506 | struct blk_mq_alloc_data data = { .flags = 0 }; |
07068d5b | 1507 | struct request *rq; |
5eb6126e | 1508 | unsigned int request_count = 0; |
f984df1f | 1509 | struct blk_plug *plug; |
5b3f341f | 1510 | struct request *same_queue_rq = NULL; |
7b371636 | 1511 | blk_qc_t cookie; |
87760e5e | 1512 | unsigned int wb_acct; |
07068d5b JA |
1513 | |
1514 | blk_queue_bounce(q, &bio); | |
1515 | ||
f36ea50c WX |
1516 | blk_queue_split(q, &bio, q->bio_split); |
1517 | ||
07068d5b | 1518 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { |
4246a0b6 | 1519 | bio_io_error(bio); |
dece1635 | 1520 | return BLK_QC_T_NONE; |
07068d5b JA |
1521 | } |
1522 | ||
87c279e6 OS |
1523 | if (!is_flush_fua && !blk_queue_nomerges(q) && |
1524 | blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq)) | |
1525 | return BLK_QC_T_NONE; | |
f984df1f | 1526 | |
bd166ef1 JA |
1527 | if (blk_mq_sched_bio_merge(q, bio)) |
1528 | return BLK_QC_T_NONE; | |
1529 | ||
87760e5e JA |
1530 | wb_acct = wbt_wait(q->rq_wb, bio, NULL); |
1531 | ||
bd166ef1 JA |
1532 | trace_block_getrq(q, bio, bio->bi_opf); |
1533 | ||
d2c0d383 | 1534 | rq = blk_mq_get_request(q, bio, bio->bi_opf, &data); |
87760e5e JA |
1535 | if (unlikely(!rq)) { |
1536 | __wbt_done(q->rq_wb, wb_acct); | |
dece1635 | 1537 | return BLK_QC_T_NONE; |
87760e5e JA |
1538 | } |
1539 | ||
1540 | wbt_track(&rq->issue_stat, wb_acct); | |
07068d5b | 1541 | |
fd2d3326 | 1542 | cookie = request_to_qc_t(data.hctx, rq); |
07068d5b | 1543 | |
f984df1f | 1544 | plug = current->plug; |
07068d5b | 1545 | if (unlikely(is_flush_fua)) { |
f984df1f | 1546 | blk_mq_put_ctx(data.ctx); |
07068d5b | 1547 | blk_mq_bio_to_request(rq, bio); |
a4d907b6 CH |
1548 | if (q->elevator) { |
1549 | blk_mq_sched_insert_request(rq, false, true, true, | |
1550 | true); | |
6a83e74d | 1551 | } else { |
a4d907b6 CH |
1552 | blk_insert_flush(rq); |
1553 | blk_mq_run_hw_queue(data.hctx, true); | |
6a83e74d | 1554 | } |
a4d907b6 | 1555 | } else if (plug && q->nr_hw_queues == 1) { |
600271d9 SL |
1556 | struct request *last = NULL; |
1557 | ||
b00c53e8 | 1558 | blk_mq_put_ctx(data.ctx); |
e6c4438b | 1559 | blk_mq_bio_to_request(rq, bio); |
0a6219a9 ML |
1560 | |
1561 | /* | |
1562 | * @request_count may become stale because of schedule | |
1563 | * out, so check the list again. | |
1564 | */ | |
1565 | if (list_empty(&plug->mq_list)) | |
1566 | request_count = 0; | |
254d259d CH |
1567 | else if (blk_queue_nomerges(q)) |
1568 | request_count = blk_plug_queued_count(q); | |
1569 | ||
676d0607 | 1570 | if (!request_count) |
e6c4438b | 1571 | trace_block_plug(q); |
600271d9 SL |
1572 | else |
1573 | last = list_entry_rq(plug->mq_list.prev); | |
b094f89c | 1574 | |
600271d9 SL |
1575 | if (request_count >= BLK_MAX_REQUEST_COUNT || (last && |
1576 | blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE)) { | |
e6c4438b JM |
1577 | blk_flush_plug_list(plug, false); |
1578 | trace_block_plug(q); | |
320ae51f | 1579 | } |
b094f89c | 1580 | |
e6c4438b | 1581 | list_add_tail(&rq->queuelist, &plug->mq_list); |
2299722c | 1582 | } else if (plug && !blk_queue_nomerges(q)) { |
bd166ef1 | 1583 | blk_mq_bio_to_request(rq, bio); |
07068d5b | 1584 | |
07068d5b | 1585 | /* |
6a83e74d | 1586 | * We do limited plugging. If the bio can be merged, do that. |
f984df1f SL |
1587 | * Otherwise the existing request in the plug list will be |
1588 | * issued. So the plug list will have one request at most | |
2299722c CH |
1589 | * The plug list might get flushed before this. If that happens, |
1590 | * the plug list is empty, and same_queue_rq is invalid. | |
07068d5b | 1591 | */ |
2299722c CH |
1592 | if (list_empty(&plug->mq_list)) |
1593 | same_queue_rq = NULL; | |
1594 | if (same_queue_rq) | |
1595 | list_del_init(&same_queue_rq->queuelist); | |
1596 | list_add_tail(&rq->queuelist, &plug->mq_list); | |
1597 | ||
bf4907c0 JA |
1598 | blk_mq_put_ctx(data.ctx); |
1599 | ||
dad7a3be ML |
1600 | if (same_queue_rq) { |
1601 | data.hctx = blk_mq_map_queue(q, | |
1602 | same_queue_rq->mq_ctx->cpu); | |
2299722c CH |
1603 | blk_mq_try_issue_directly(data.hctx, same_queue_rq, |
1604 | &cookie); | |
dad7a3be | 1605 | } |
a4d907b6 | 1606 | } else if (q->nr_hw_queues > 1 && is_sync) { |
bf4907c0 | 1607 | blk_mq_put_ctx(data.ctx); |
2299722c | 1608 | blk_mq_bio_to_request(rq, bio); |
2299722c | 1609 | blk_mq_try_issue_directly(data.hctx, rq, &cookie); |
a4d907b6 | 1610 | } else if (q->elevator) { |
b00c53e8 | 1611 | blk_mq_put_ctx(data.ctx); |
bd166ef1 | 1612 | blk_mq_bio_to_request(rq, bio); |
a4d907b6 | 1613 | blk_mq_sched_insert_request(rq, false, true, true, true); |
ab42f35d | 1614 | } else { |
b00c53e8 | 1615 | blk_mq_put_ctx(data.ctx); |
ab42f35d ML |
1616 | blk_mq_bio_to_request(rq, bio); |
1617 | blk_mq_queue_io(data.hctx, data.ctx, rq); | |
a4d907b6 | 1618 | blk_mq_run_hw_queue(data.hctx, true); |
ab42f35d | 1619 | } |
320ae51f | 1620 | |
7b371636 | 1621 | return cookie; |
320ae51f JA |
1622 | } |
1623 | ||
cc71a6f4 JA |
1624 | void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, |
1625 | unsigned int hctx_idx) | |
95363efd | 1626 | { |
e9b267d9 | 1627 | struct page *page; |
320ae51f | 1628 | |
24d2f903 | 1629 | if (tags->rqs && set->ops->exit_request) { |
e9b267d9 | 1630 | int i; |
320ae51f | 1631 | |
24d2f903 | 1632 | for (i = 0; i < tags->nr_tags; i++) { |
2af8cbe3 JA |
1633 | struct request *rq = tags->static_rqs[i]; |
1634 | ||
1635 | if (!rq) | |
e9b267d9 | 1636 | continue; |
d6296d39 | 1637 | set->ops->exit_request(set, rq, hctx_idx); |
2af8cbe3 | 1638 | tags->static_rqs[i] = NULL; |
e9b267d9 | 1639 | } |
320ae51f | 1640 | } |
320ae51f | 1641 | |
24d2f903 CH |
1642 | while (!list_empty(&tags->page_list)) { |
1643 | page = list_first_entry(&tags->page_list, struct page, lru); | |
6753471c | 1644 | list_del_init(&page->lru); |
f75782e4 CM |
1645 | /* |
1646 | * Remove kmemleak object previously allocated in | |
1647 | * blk_mq_init_rq_map(). | |
1648 | */ | |
1649 | kmemleak_free(page_address(page)); | |
320ae51f JA |
1650 | __free_pages(page, page->private); |
1651 | } | |
cc71a6f4 | 1652 | } |
320ae51f | 1653 | |
cc71a6f4 JA |
1654 | void blk_mq_free_rq_map(struct blk_mq_tags *tags) |
1655 | { | |
24d2f903 | 1656 | kfree(tags->rqs); |
cc71a6f4 | 1657 | tags->rqs = NULL; |
2af8cbe3 JA |
1658 | kfree(tags->static_rqs); |
1659 | tags->static_rqs = NULL; | |
320ae51f | 1660 | |
24d2f903 | 1661 | blk_mq_free_tags(tags); |
320ae51f JA |
1662 | } |
1663 | ||
cc71a6f4 JA |
1664 | struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, |
1665 | unsigned int hctx_idx, | |
1666 | unsigned int nr_tags, | |
1667 | unsigned int reserved_tags) | |
320ae51f | 1668 | { |
24d2f903 | 1669 | struct blk_mq_tags *tags; |
59f082e4 | 1670 | int node; |
320ae51f | 1671 | |
59f082e4 SL |
1672 | node = blk_mq_hw_queue_to_node(set->mq_map, hctx_idx); |
1673 | if (node == NUMA_NO_NODE) | |
1674 | node = set->numa_node; | |
1675 | ||
1676 | tags = blk_mq_init_tags(nr_tags, reserved_tags, node, | |
24391c0d | 1677 | BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags)); |
24d2f903 CH |
1678 | if (!tags) |
1679 | return NULL; | |
320ae51f | 1680 | |
cc71a6f4 | 1681 | tags->rqs = kzalloc_node(nr_tags * sizeof(struct request *), |
36e1f3d1 | 1682 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, |
59f082e4 | 1683 | node); |
24d2f903 CH |
1684 | if (!tags->rqs) { |
1685 | blk_mq_free_tags(tags); | |
1686 | return NULL; | |
1687 | } | |
320ae51f | 1688 | |
2af8cbe3 JA |
1689 | tags->static_rqs = kzalloc_node(nr_tags * sizeof(struct request *), |
1690 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, | |
59f082e4 | 1691 | node); |
2af8cbe3 JA |
1692 | if (!tags->static_rqs) { |
1693 | kfree(tags->rqs); | |
1694 | blk_mq_free_tags(tags); | |
1695 | return NULL; | |
1696 | } | |
1697 | ||
cc71a6f4 JA |
1698 | return tags; |
1699 | } | |
1700 | ||
1701 | static size_t order_to_size(unsigned int order) | |
1702 | { | |
1703 | return (size_t)PAGE_SIZE << order; | |
1704 | } | |
1705 | ||
1706 | int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, | |
1707 | unsigned int hctx_idx, unsigned int depth) | |
1708 | { | |
1709 | unsigned int i, j, entries_per_page, max_order = 4; | |
1710 | size_t rq_size, left; | |
59f082e4 SL |
1711 | int node; |
1712 | ||
1713 | node = blk_mq_hw_queue_to_node(set->mq_map, hctx_idx); | |
1714 | if (node == NUMA_NO_NODE) | |
1715 | node = set->numa_node; | |
cc71a6f4 JA |
1716 | |
1717 | INIT_LIST_HEAD(&tags->page_list); | |
1718 | ||
320ae51f JA |
1719 | /* |
1720 | * rq_size is the size of the request plus driver payload, rounded | |
1721 | * to the cacheline size | |
1722 | */ | |
24d2f903 | 1723 | rq_size = round_up(sizeof(struct request) + set->cmd_size, |
320ae51f | 1724 | cache_line_size()); |
cc71a6f4 | 1725 | left = rq_size * depth; |
320ae51f | 1726 | |
cc71a6f4 | 1727 | for (i = 0; i < depth; ) { |
320ae51f JA |
1728 | int this_order = max_order; |
1729 | struct page *page; | |
1730 | int to_do; | |
1731 | void *p; | |
1732 | ||
b3a834b1 | 1733 | while (this_order && left < order_to_size(this_order - 1)) |
320ae51f JA |
1734 | this_order--; |
1735 | ||
1736 | do { | |
59f082e4 | 1737 | page = alloc_pages_node(node, |
36e1f3d1 | 1738 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO, |
a5164405 | 1739 | this_order); |
320ae51f JA |
1740 | if (page) |
1741 | break; | |
1742 | if (!this_order--) | |
1743 | break; | |
1744 | if (order_to_size(this_order) < rq_size) | |
1745 | break; | |
1746 | } while (1); | |
1747 | ||
1748 | if (!page) | |
24d2f903 | 1749 | goto fail; |
320ae51f JA |
1750 | |
1751 | page->private = this_order; | |
24d2f903 | 1752 | list_add_tail(&page->lru, &tags->page_list); |
320ae51f JA |
1753 | |
1754 | p = page_address(page); | |
f75782e4 CM |
1755 | /* |
1756 | * Allow kmemleak to scan these pages as they contain pointers | |
1757 | * to additional allocations like via ops->init_request(). | |
1758 | */ | |
36e1f3d1 | 1759 | kmemleak_alloc(p, order_to_size(this_order), 1, GFP_NOIO); |
320ae51f | 1760 | entries_per_page = order_to_size(this_order) / rq_size; |
cc71a6f4 | 1761 | to_do = min(entries_per_page, depth - i); |
320ae51f JA |
1762 | left -= to_do * rq_size; |
1763 | for (j = 0; j < to_do; j++) { | |
2af8cbe3 JA |
1764 | struct request *rq = p; |
1765 | ||
1766 | tags->static_rqs[i] = rq; | |
24d2f903 | 1767 | if (set->ops->init_request) { |
d6296d39 | 1768 | if (set->ops->init_request(set, rq, hctx_idx, |
59f082e4 | 1769 | node)) { |
2af8cbe3 | 1770 | tags->static_rqs[i] = NULL; |
24d2f903 | 1771 | goto fail; |
a5164405 | 1772 | } |
e9b267d9 CH |
1773 | } |
1774 | ||
320ae51f JA |
1775 | p += rq_size; |
1776 | i++; | |
1777 | } | |
1778 | } | |
cc71a6f4 | 1779 | return 0; |
320ae51f | 1780 | |
24d2f903 | 1781 | fail: |
cc71a6f4 JA |
1782 | blk_mq_free_rqs(set, tags, hctx_idx); |
1783 | return -ENOMEM; | |
320ae51f JA |
1784 | } |
1785 | ||
e57690fe JA |
1786 | /* |
1787 | * 'cpu' is going away. splice any existing rq_list entries from this | |
1788 | * software queue to the hw queue dispatch list, and ensure that it | |
1789 | * gets run. | |
1790 | */ | |
9467f859 | 1791 | static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node) |
484b4061 | 1792 | { |
9467f859 | 1793 | struct blk_mq_hw_ctx *hctx; |
484b4061 JA |
1794 | struct blk_mq_ctx *ctx; |
1795 | LIST_HEAD(tmp); | |
1796 | ||
9467f859 | 1797 | hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_dead); |
e57690fe | 1798 | ctx = __blk_mq_get_ctx(hctx->queue, cpu); |
484b4061 JA |
1799 | |
1800 | spin_lock(&ctx->lock); | |
1801 | if (!list_empty(&ctx->rq_list)) { | |
1802 | list_splice_init(&ctx->rq_list, &tmp); | |
1803 | blk_mq_hctx_clear_pending(hctx, ctx); | |
1804 | } | |
1805 | spin_unlock(&ctx->lock); | |
1806 | ||
1807 | if (list_empty(&tmp)) | |
9467f859 | 1808 | return 0; |
484b4061 | 1809 | |
e57690fe JA |
1810 | spin_lock(&hctx->lock); |
1811 | list_splice_tail_init(&tmp, &hctx->dispatch); | |
1812 | spin_unlock(&hctx->lock); | |
484b4061 JA |
1813 | |
1814 | blk_mq_run_hw_queue(hctx, true); | |
9467f859 | 1815 | return 0; |
484b4061 JA |
1816 | } |
1817 | ||
9467f859 | 1818 | static void blk_mq_remove_cpuhp(struct blk_mq_hw_ctx *hctx) |
484b4061 | 1819 | { |
9467f859 TG |
1820 | cpuhp_state_remove_instance_nocalls(CPUHP_BLK_MQ_DEAD, |
1821 | &hctx->cpuhp_dead); | |
484b4061 JA |
1822 | } |
1823 | ||
c3b4afca | 1824 | /* hctx->ctxs will be freed in queue's release handler */ |
08e98fc6 ML |
1825 | static void blk_mq_exit_hctx(struct request_queue *q, |
1826 | struct blk_mq_tag_set *set, | |
1827 | struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) | |
1828 | { | |
9c1051aa OS |
1829 | blk_mq_debugfs_unregister_hctx(hctx); |
1830 | ||
08e98fc6 ML |
1831 | blk_mq_tag_idle(hctx); |
1832 | ||
f70ced09 | 1833 | if (set->ops->exit_request) |
d6296d39 | 1834 | set->ops->exit_request(set, hctx->fq->flush_rq, hctx_idx); |
f70ced09 | 1835 | |
93252632 OS |
1836 | blk_mq_sched_exit_hctx(q, hctx, hctx_idx); |
1837 | ||
08e98fc6 ML |
1838 | if (set->ops->exit_hctx) |
1839 | set->ops->exit_hctx(hctx, hctx_idx); | |
1840 | ||
6a83e74d BVA |
1841 | if (hctx->flags & BLK_MQ_F_BLOCKING) |
1842 | cleanup_srcu_struct(&hctx->queue_rq_srcu); | |
1843 | ||
9467f859 | 1844 | blk_mq_remove_cpuhp(hctx); |
f70ced09 | 1845 | blk_free_flush_queue(hctx->fq); |
88459642 | 1846 | sbitmap_free(&hctx->ctx_map); |
08e98fc6 ML |
1847 | } |
1848 | ||
624dbe47 ML |
1849 | static void blk_mq_exit_hw_queues(struct request_queue *q, |
1850 | struct blk_mq_tag_set *set, int nr_queue) | |
1851 | { | |
1852 | struct blk_mq_hw_ctx *hctx; | |
1853 | unsigned int i; | |
1854 | ||
1855 | queue_for_each_hw_ctx(q, hctx, i) { | |
1856 | if (i == nr_queue) | |
1857 | break; | |
08e98fc6 | 1858 | blk_mq_exit_hctx(q, set, hctx, i); |
624dbe47 | 1859 | } |
624dbe47 ML |
1860 | } |
1861 | ||
08e98fc6 ML |
1862 | static int blk_mq_init_hctx(struct request_queue *q, |
1863 | struct blk_mq_tag_set *set, | |
1864 | struct blk_mq_hw_ctx *hctx, unsigned hctx_idx) | |
320ae51f | 1865 | { |
08e98fc6 ML |
1866 | int node; |
1867 | ||
1868 | node = hctx->numa_node; | |
1869 | if (node == NUMA_NO_NODE) | |
1870 | node = hctx->numa_node = set->numa_node; | |
1871 | ||
9f993737 | 1872 | INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn); |
08e98fc6 ML |
1873 | spin_lock_init(&hctx->lock); |
1874 | INIT_LIST_HEAD(&hctx->dispatch); | |
1875 | hctx->queue = q; | |
1876 | hctx->queue_num = hctx_idx; | |
2404e607 | 1877 | hctx->flags = set->flags & ~BLK_MQ_F_TAG_SHARED; |
08e98fc6 | 1878 | |
9467f859 | 1879 | cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, &hctx->cpuhp_dead); |
08e98fc6 ML |
1880 | |
1881 | hctx->tags = set->tags[hctx_idx]; | |
320ae51f JA |
1882 | |
1883 | /* | |
08e98fc6 ML |
1884 | * Allocate space for all possible cpus to avoid allocation at |
1885 | * runtime | |
320ae51f | 1886 | */ |
08e98fc6 ML |
1887 | hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *), |
1888 | GFP_KERNEL, node); | |
1889 | if (!hctx->ctxs) | |
1890 | goto unregister_cpu_notifier; | |
320ae51f | 1891 | |
88459642 OS |
1892 | if (sbitmap_init_node(&hctx->ctx_map, nr_cpu_ids, ilog2(8), GFP_KERNEL, |
1893 | node)) | |
08e98fc6 | 1894 | goto free_ctxs; |
320ae51f | 1895 | |
08e98fc6 | 1896 | hctx->nr_ctx = 0; |
320ae51f | 1897 | |
08e98fc6 ML |
1898 | if (set->ops->init_hctx && |
1899 | set->ops->init_hctx(hctx, set->driver_data, hctx_idx)) | |
1900 | goto free_bitmap; | |
320ae51f | 1901 | |
93252632 OS |
1902 | if (blk_mq_sched_init_hctx(q, hctx, hctx_idx)) |
1903 | goto exit_hctx; | |
1904 | ||
f70ced09 ML |
1905 | hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size); |
1906 | if (!hctx->fq) | |
93252632 | 1907 | goto sched_exit_hctx; |
320ae51f | 1908 | |
f70ced09 | 1909 | if (set->ops->init_request && |
d6296d39 CH |
1910 | set->ops->init_request(set, hctx->fq->flush_rq, hctx_idx, |
1911 | node)) | |
f70ced09 | 1912 | goto free_fq; |
320ae51f | 1913 | |
6a83e74d BVA |
1914 | if (hctx->flags & BLK_MQ_F_BLOCKING) |
1915 | init_srcu_struct(&hctx->queue_rq_srcu); | |
1916 | ||
9c1051aa OS |
1917 | blk_mq_debugfs_register_hctx(q, hctx); |
1918 | ||
08e98fc6 | 1919 | return 0; |
320ae51f | 1920 | |
f70ced09 ML |
1921 | free_fq: |
1922 | kfree(hctx->fq); | |
93252632 OS |
1923 | sched_exit_hctx: |
1924 | blk_mq_sched_exit_hctx(q, hctx, hctx_idx); | |
f70ced09 ML |
1925 | exit_hctx: |
1926 | if (set->ops->exit_hctx) | |
1927 | set->ops->exit_hctx(hctx, hctx_idx); | |
08e98fc6 | 1928 | free_bitmap: |
88459642 | 1929 | sbitmap_free(&hctx->ctx_map); |
08e98fc6 ML |
1930 | free_ctxs: |
1931 | kfree(hctx->ctxs); | |
1932 | unregister_cpu_notifier: | |
9467f859 | 1933 | blk_mq_remove_cpuhp(hctx); |
08e98fc6 ML |
1934 | return -1; |
1935 | } | |
320ae51f | 1936 | |
320ae51f JA |
1937 | static void blk_mq_init_cpu_queues(struct request_queue *q, |
1938 | unsigned int nr_hw_queues) | |
1939 | { | |
1940 | unsigned int i; | |
1941 | ||
1942 | for_each_possible_cpu(i) { | |
1943 | struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i); | |
1944 | struct blk_mq_hw_ctx *hctx; | |
1945 | ||
320ae51f JA |
1946 | __ctx->cpu = i; |
1947 | spin_lock_init(&__ctx->lock); | |
1948 | INIT_LIST_HEAD(&__ctx->rq_list); | |
1949 | __ctx->queue = q; | |
1950 | ||
1951 | /* If the cpu isn't online, the cpu is mapped to first hctx */ | |
320ae51f JA |
1952 | if (!cpu_online(i)) |
1953 | continue; | |
1954 | ||
7d7e0f90 | 1955 | hctx = blk_mq_map_queue(q, i); |
e4043dcf | 1956 | |
320ae51f JA |
1957 | /* |
1958 | * Set local node, IFF we have more than one hw queue. If | |
1959 | * not, we remain on the home node of the device | |
1960 | */ | |
1961 | if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE) | |
bffed457 | 1962 | hctx->numa_node = local_memory_node(cpu_to_node(i)); |
320ae51f JA |
1963 | } |
1964 | } | |
1965 | ||
cc71a6f4 JA |
1966 | static bool __blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, int hctx_idx) |
1967 | { | |
1968 | int ret = 0; | |
1969 | ||
1970 | set->tags[hctx_idx] = blk_mq_alloc_rq_map(set, hctx_idx, | |
1971 | set->queue_depth, set->reserved_tags); | |
1972 | if (!set->tags[hctx_idx]) | |
1973 | return false; | |
1974 | ||
1975 | ret = blk_mq_alloc_rqs(set, set->tags[hctx_idx], hctx_idx, | |
1976 | set->queue_depth); | |
1977 | if (!ret) | |
1978 | return true; | |
1979 | ||
1980 | blk_mq_free_rq_map(set->tags[hctx_idx]); | |
1981 | set->tags[hctx_idx] = NULL; | |
1982 | return false; | |
1983 | } | |
1984 | ||
1985 | static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set, | |
1986 | unsigned int hctx_idx) | |
1987 | { | |
bd166ef1 JA |
1988 | if (set->tags[hctx_idx]) { |
1989 | blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx); | |
1990 | blk_mq_free_rq_map(set->tags[hctx_idx]); | |
1991 | set->tags[hctx_idx] = NULL; | |
1992 | } | |
cc71a6f4 JA |
1993 | } |
1994 | ||
5778322e AM |
1995 | static void blk_mq_map_swqueue(struct request_queue *q, |
1996 | const struct cpumask *online_mask) | |
320ae51f | 1997 | { |
d1b1cea1 | 1998 | unsigned int i, hctx_idx; |
320ae51f JA |
1999 | struct blk_mq_hw_ctx *hctx; |
2000 | struct blk_mq_ctx *ctx; | |
2a34c087 | 2001 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 2002 | |
60de074b AM |
2003 | /* |
2004 | * Avoid others reading imcomplete hctx->cpumask through sysfs | |
2005 | */ | |
2006 | mutex_lock(&q->sysfs_lock); | |
2007 | ||
320ae51f | 2008 | queue_for_each_hw_ctx(q, hctx, i) { |
e4043dcf | 2009 | cpumask_clear(hctx->cpumask); |
320ae51f JA |
2010 | hctx->nr_ctx = 0; |
2011 | } | |
2012 | ||
2013 | /* | |
2014 | * Map software to hardware queues | |
2015 | */ | |
897bb0c7 | 2016 | for_each_possible_cpu(i) { |
320ae51f | 2017 | /* If the cpu isn't online, the cpu is mapped to first hctx */ |
5778322e | 2018 | if (!cpumask_test_cpu(i, online_mask)) |
e4043dcf JA |
2019 | continue; |
2020 | ||
d1b1cea1 GKB |
2021 | hctx_idx = q->mq_map[i]; |
2022 | /* unmapped hw queue can be remapped after CPU topo changed */ | |
cc71a6f4 JA |
2023 | if (!set->tags[hctx_idx] && |
2024 | !__blk_mq_alloc_rq_map(set, hctx_idx)) { | |
d1b1cea1 GKB |
2025 | /* |
2026 | * If tags initialization fail for some hctx, | |
2027 | * that hctx won't be brought online. In this | |
2028 | * case, remap the current ctx to hctx[0] which | |
2029 | * is guaranteed to always have tags allocated | |
2030 | */ | |
cc71a6f4 | 2031 | q->mq_map[i] = 0; |
d1b1cea1 GKB |
2032 | } |
2033 | ||
897bb0c7 | 2034 | ctx = per_cpu_ptr(q->queue_ctx, i); |
7d7e0f90 | 2035 | hctx = blk_mq_map_queue(q, i); |
868f2f0b | 2036 | |
e4043dcf | 2037 | cpumask_set_cpu(i, hctx->cpumask); |
320ae51f JA |
2038 | ctx->index_hw = hctx->nr_ctx; |
2039 | hctx->ctxs[hctx->nr_ctx++] = ctx; | |
2040 | } | |
506e931f | 2041 | |
60de074b AM |
2042 | mutex_unlock(&q->sysfs_lock); |
2043 | ||
506e931f | 2044 | queue_for_each_hw_ctx(q, hctx, i) { |
484b4061 | 2045 | /* |
a68aafa5 JA |
2046 | * If no software queues are mapped to this hardware queue, |
2047 | * disable it and free the request entries. | |
484b4061 JA |
2048 | */ |
2049 | if (!hctx->nr_ctx) { | |
d1b1cea1 GKB |
2050 | /* Never unmap queue 0. We need it as a |
2051 | * fallback in case of a new remap fails | |
2052 | * allocation | |
2053 | */ | |
cc71a6f4 JA |
2054 | if (i && set->tags[i]) |
2055 | blk_mq_free_map_and_requests(set, i); | |
2056 | ||
2a34c087 | 2057 | hctx->tags = NULL; |
484b4061 JA |
2058 | continue; |
2059 | } | |
2060 | ||
2a34c087 ML |
2061 | hctx->tags = set->tags[i]; |
2062 | WARN_ON(!hctx->tags); | |
2063 | ||
889fa31f CY |
2064 | /* |
2065 | * Set the map size to the number of mapped software queues. | |
2066 | * This is more accurate and more efficient than looping | |
2067 | * over all possibly mapped software queues. | |
2068 | */ | |
88459642 | 2069 | sbitmap_resize(&hctx->ctx_map, hctx->nr_ctx); |
889fa31f | 2070 | |
484b4061 JA |
2071 | /* |
2072 | * Initialize batch roundrobin counts | |
2073 | */ | |
506e931f JA |
2074 | hctx->next_cpu = cpumask_first(hctx->cpumask); |
2075 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
2076 | } | |
320ae51f JA |
2077 | } |
2078 | ||
2404e607 | 2079 | static void queue_set_hctx_shared(struct request_queue *q, bool shared) |
0d2602ca JA |
2080 | { |
2081 | struct blk_mq_hw_ctx *hctx; | |
0d2602ca JA |
2082 | int i; |
2083 | ||
2404e607 JM |
2084 | queue_for_each_hw_ctx(q, hctx, i) { |
2085 | if (shared) | |
2086 | hctx->flags |= BLK_MQ_F_TAG_SHARED; | |
2087 | else | |
2088 | hctx->flags &= ~BLK_MQ_F_TAG_SHARED; | |
2089 | } | |
2090 | } | |
2091 | ||
2092 | static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set, bool shared) | |
2093 | { | |
2094 | struct request_queue *q; | |
0d2602ca | 2095 | |
705cda97 BVA |
2096 | lockdep_assert_held(&set->tag_list_lock); |
2097 | ||
0d2602ca JA |
2098 | list_for_each_entry(q, &set->tag_list, tag_set_list) { |
2099 | blk_mq_freeze_queue(q); | |
2404e607 | 2100 | queue_set_hctx_shared(q, shared); |
0d2602ca JA |
2101 | blk_mq_unfreeze_queue(q); |
2102 | } | |
2103 | } | |
2104 | ||
2105 | static void blk_mq_del_queue_tag_set(struct request_queue *q) | |
2106 | { | |
2107 | struct blk_mq_tag_set *set = q->tag_set; | |
2108 | ||
0d2602ca | 2109 | mutex_lock(&set->tag_list_lock); |
705cda97 BVA |
2110 | list_del_rcu(&q->tag_set_list); |
2111 | INIT_LIST_HEAD(&q->tag_set_list); | |
2404e607 JM |
2112 | if (list_is_singular(&set->tag_list)) { |
2113 | /* just transitioned to unshared */ | |
2114 | set->flags &= ~BLK_MQ_F_TAG_SHARED; | |
2115 | /* update existing queue */ | |
2116 | blk_mq_update_tag_set_depth(set, false); | |
2117 | } | |
0d2602ca | 2118 | mutex_unlock(&set->tag_list_lock); |
705cda97 BVA |
2119 | |
2120 | synchronize_rcu(); | |
0d2602ca JA |
2121 | } |
2122 | ||
2123 | static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, | |
2124 | struct request_queue *q) | |
2125 | { | |
2126 | q->tag_set = set; | |
2127 | ||
2128 | mutex_lock(&set->tag_list_lock); | |
2404e607 JM |
2129 | |
2130 | /* Check to see if we're transitioning to shared (from 1 to 2 queues). */ | |
2131 | if (!list_empty(&set->tag_list) && !(set->flags & BLK_MQ_F_TAG_SHARED)) { | |
2132 | set->flags |= BLK_MQ_F_TAG_SHARED; | |
2133 | /* update existing queue */ | |
2134 | blk_mq_update_tag_set_depth(set, true); | |
2135 | } | |
2136 | if (set->flags & BLK_MQ_F_TAG_SHARED) | |
2137 | queue_set_hctx_shared(q, true); | |
705cda97 | 2138 | list_add_tail_rcu(&q->tag_set_list, &set->tag_list); |
2404e607 | 2139 | |
0d2602ca JA |
2140 | mutex_unlock(&set->tag_list_lock); |
2141 | } | |
2142 | ||
e09aae7e ML |
2143 | /* |
2144 | * It is the actual release handler for mq, but we do it from | |
2145 | * request queue's release handler for avoiding use-after-free | |
2146 | * and headache because q->mq_kobj shouldn't have been introduced, | |
2147 | * but we can't group ctx/kctx kobj without it. | |
2148 | */ | |
2149 | void blk_mq_release(struct request_queue *q) | |
2150 | { | |
2151 | struct blk_mq_hw_ctx *hctx; | |
2152 | unsigned int i; | |
2153 | ||
2154 | /* hctx kobj stays in hctx */ | |
c3b4afca ML |
2155 | queue_for_each_hw_ctx(q, hctx, i) { |
2156 | if (!hctx) | |
2157 | continue; | |
6c8b232e | 2158 | kobject_put(&hctx->kobj); |
c3b4afca | 2159 | } |
e09aae7e | 2160 | |
a723bab3 AM |
2161 | q->mq_map = NULL; |
2162 | ||
e09aae7e ML |
2163 | kfree(q->queue_hw_ctx); |
2164 | ||
7ea5fe31 ML |
2165 | /* |
2166 | * release .mq_kobj and sw queue's kobject now because | |
2167 | * both share lifetime with request queue. | |
2168 | */ | |
2169 | blk_mq_sysfs_deinit(q); | |
2170 | ||
e09aae7e ML |
2171 | free_percpu(q->queue_ctx); |
2172 | } | |
2173 | ||
24d2f903 | 2174 | struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) |
b62c21b7 MS |
2175 | { |
2176 | struct request_queue *uninit_q, *q; | |
2177 | ||
2178 | uninit_q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node); | |
2179 | if (!uninit_q) | |
2180 | return ERR_PTR(-ENOMEM); | |
2181 | ||
2182 | q = blk_mq_init_allocated_queue(set, uninit_q); | |
2183 | if (IS_ERR(q)) | |
2184 | blk_cleanup_queue(uninit_q); | |
2185 | ||
2186 | return q; | |
2187 | } | |
2188 | EXPORT_SYMBOL(blk_mq_init_queue); | |
2189 | ||
868f2f0b KB |
2190 | static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, |
2191 | struct request_queue *q) | |
320ae51f | 2192 | { |
868f2f0b KB |
2193 | int i, j; |
2194 | struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx; | |
f14bbe77 | 2195 | |
868f2f0b | 2196 | blk_mq_sysfs_unregister(q); |
24d2f903 | 2197 | for (i = 0; i < set->nr_hw_queues; i++) { |
868f2f0b | 2198 | int node; |
f14bbe77 | 2199 | |
868f2f0b KB |
2200 | if (hctxs[i]) |
2201 | continue; | |
2202 | ||
2203 | node = blk_mq_hw_queue_to_node(q->mq_map, i); | |
cdef54dd CH |
2204 | hctxs[i] = kzalloc_node(sizeof(struct blk_mq_hw_ctx), |
2205 | GFP_KERNEL, node); | |
320ae51f | 2206 | if (!hctxs[i]) |
868f2f0b | 2207 | break; |
320ae51f | 2208 | |
a86073e4 | 2209 | if (!zalloc_cpumask_var_node(&hctxs[i]->cpumask, GFP_KERNEL, |
868f2f0b KB |
2210 | node)) { |
2211 | kfree(hctxs[i]); | |
2212 | hctxs[i] = NULL; | |
2213 | break; | |
2214 | } | |
e4043dcf | 2215 | |
0d2602ca | 2216 | atomic_set(&hctxs[i]->nr_active, 0); |
f14bbe77 | 2217 | hctxs[i]->numa_node = node; |
320ae51f | 2218 | hctxs[i]->queue_num = i; |
868f2f0b KB |
2219 | |
2220 | if (blk_mq_init_hctx(q, set, hctxs[i], i)) { | |
2221 | free_cpumask_var(hctxs[i]->cpumask); | |
2222 | kfree(hctxs[i]); | |
2223 | hctxs[i] = NULL; | |
2224 | break; | |
2225 | } | |
2226 | blk_mq_hctx_kobj_init(hctxs[i]); | |
320ae51f | 2227 | } |
868f2f0b KB |
2228 | for (j = i; j < q->nr_hw_queues; j++) { |
2229 | struct blk_mq_hw_ctx *hctx = hctxs[j]; | |
2230 | ||
2231 | if (hctx) { | |
cc71a6f4 JA |
2232 | if (hctx->tags) |
2233 | blk_mq_free_map_and_requests(set, j); | |
868f2f0b | 2234 | blk_mq_exit_hctx(q, set, hctx, j); |
868f2f0b | 2235 | kobject_put(&hctx->kobj); |
868f2f0b KB |
2236 | hctxs[j] = NULL; |
2237 | ||
2238 | } | |
2239 | } | |
2240 | q->nr_hw_queues = i; | |
2241 | blk_mq_sysfs_register(q); | |
2242 | } | |
2243 | ||
2244 | struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, | |
2245 | struct request_queue *q) | |
2246 | { | |
66841672 ML |
2247 | /* mark the queue as mq asap */ |
2248 | q->mq_ops = set->ops; | |
2249 | ||
34dbad5d | 2250 | q->poll_cb = blk_stat_alloc_callback(blk_mq_poll_stats_fn, |
720b8ccc SB |
2251 | blk_mq_poll_stats_bkt, |
2252 | BLK_MQ_POLL_STATS_BKTS, q); | |
34dbad5d OS |
2253 | if (!q->poll_cb) |
2254 | goto err_exit; | |
2255 | ||
868f2f0b KB |
2256 | q->queue_ctx = alloc_percpu(struct blk_mq_ctx); |
2257 | if (!q->queue_ctx) | |
c7de5726 | 2258 | goto err_exit; |
868f2f0b | 2259 | |
737f98cf ML |
2260 | /* init q->mq_kobj and sw queues' kobjects */ |
2261 | blk_mq_sysfs_init(q); | |
2262 | ||
868f2f0b KB |
2263 | q->queue_hw_ctx = kzalloc_node(nr_cpu_ids * sizeof(*(q->queue_hw_ctx)), |
2264 | GFP_KERNEL, set->numa_node); | |
2265 | if (!q->queue_hw_ctx) | |
2266 | goto err_percpu; | |
2267 | ||
bdd17e75 | 2268 | q->mq_map = set->mq_map; |
868f2f0b KB |
2269 | |
2270 | blk_mq_realloc_hw_ctxs(set, q); | |
2271 | if (!q->nr_hw_queues) | |
2272 | goto err_hctxs; | |
320ae51f | 2273 | |
287922eb | 2274 | INIT_WORK(&q->timeout_work, blk_mq_timeout_work); |
e56f698b | 2275 | blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ); |
320ae51f JA |
2276 | |
2277 | q->nr_queues = nr_cpu_ids; | |
320ae51f | 2278 | |
94eddfbe | 2279 | q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; |
320ae51f | 2280 | |
05f1dd53 JA |
2281 | if (!(set->flags & BLK_MQ_F_SG_MERGE)) |
2282 | q->queue_flags |= 1 << QUEUE_FLAG_NO_SG_MERGE; | |
2283 | ||
1be036e9 CH |
2284 | q->sg_reserved_size = INT_MAX; |
2285 | ||
2849450a | 2286 | INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work); |
6fca6a61 CH |
2287 | INIT_LIST_HEAD(&q->requeue_list); |
2288 | spin_lock_init(&q->requeue_lock); | |
2289 | ||
254d259d | 2290 | blk_queue_make_request(q, blk_mq_make_request); |
07068d5b | 2291 | |
eba71768 JA |
2292 | /* |
2293 | * Do this after blk_queue_make_request() overrides it... | |
2294 | */ | |
2295 | q->nr_requests = set->queue_depth; | |
2296 | ||
64f1c21e JA |
2297 | /* |
2298 | * Default to classic polling | |
2299 | */ | |
2300 | q->poll_nsec = -1; | |
2301 | ||
24d2f903 CH |
2302 | if (set->ops->complete) |
2303 | blk_queue_softirq_done(q, set->ops->complete); | |
30a91cb4 | 2304 | |
24d2f903 | 2305 | blk_mq_init_cpu_queues(q, set->nr_hw_queues); |
320ae51f | 2306 | |
eabe0659 | 2307 | get_online_cpus(); |
51d638b1 | 2308 | mutex_lock(&all_q_mutex); |
320ae51f | 2309 | |
4593fdbe | 2310 | list_add_tail(&q->all_q_node, &all_q_list); |
0d2602ca | 2311 | blk_mq_add_queue_tag_set(set, q); |
5778322e | 2312 | blk_mq_map_swqueue(q, cpu_online_mask); |
484b4061 | 2313 | |
eabe0659 | 2314 | mutex_unlock(&all_q_mutex); |
51d638b1 | 2315 | put_online_cpus(); |
4593fdbe | 2316 | |
d3484991 JA |
2317 | if (!(set->flags & BLK_MQ_F_NO_SCHED)) { |
2318 | int ret; | |
2319 | ||
2320 | ret = blk_mq_sched_init(q); | |
2321 | if (ret) | |
2322 | return ERR_PTR(ret); | |
2323 | } | |
2324 | ||
320ae51f | 2325 | return q; |
18741986 | 2326 | |
320ae51f | 2327 | err_hctxs: |
868f2f0b | 2328 | kfree(q->queue_hw_ctx); |
320ae51f | 2329 | err_percpu: |
868f2f0b | 2330 | free_percpu(q->queue_ctx); |
c7de5726 ML |
2331 | err_exit: |
2332 | q->mq_ops = NULL; | |
320ae51f JA |
2333 | return ERR_PTR(-ENOMEM); |
2334 | } | |
b62c21b7 | 2335 | EXPORT_SYMBOL(blk_mq_init_allocated_queue); |
320ae51f JA |
2336 | |
2337 | void blk_mq_free_queue(struct request_queue *q) | |
2338 | { | |
624dbe47 | 2339 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 2340 | |
0e626368 AM |
2341 | mutex_lock(&all_q_mutex); |
2342 | list_del_init(&q->all_q_node); | |
2343 | mutex_unlock(&all_q_mutex); | |
2344 | ||
0d2602ca JA |
2345 | blk_mq_del_queue_tag_set(q); |
2346 | ||
624dbe47 | 2347 | blk_mq_exit_hw_queues(q, set, set->nr_hw_queues); |
320ae51f | 2348 | } |
320ae51f JA |
2349 | |
2350 | /* Basically redo blk_mq_init_queue with queue frozen */ | |
5778322e AM |
2351 | static void blk_mq_queue_reinit(struct request_queue *q, |
2352 | const struct cpumask *online_mask) | |
320ae51f | 2353 | { |
4ecd4fef | 2354 | WARN_ON_ONCE(!atomic_read(&q->mq_freeze_depth)); |
320ae51f | 2355 | |
9c1051aa | 2356 | blk_mq_debugfs_unregister_hctxs(q); |
67aec14c JA |
2357 | blk_mq_sysfs_unregister(q); |
2358 | ||
320ae51f JA |
2359 | /* |
2360 | * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe | |
2361 | * we should change hctx numa_node according to new topology (this | |
2362 | * involves free and re-allocate memory, worthy doing?) | |
2363 | */ | |
2364 | ||
5778322e | 2365 | blk_mq_map_swqueue(q, online_mask); |
320ae51f | 2366 | |
67aec14c | 2367 | blk_mq_sysfs_register(q); |
9c1051aa | 2368 | blk_mq_debugfs_register_hctxs(q); |
320ae51f JA |
2369 | } |
2370 | ||
65d5291e SAS |
2371 | /* |
2372 | * New online cpumask which is going to be set in this hotplug event. | |
2373 | * Declare this cpumasks as global as cpu-hotplug operation is invoked | |
2374 | * one-by-one and dynamically allocating this could result in a failure. | |
2375 | */ | |
2376 | static struct cpumask cpuhp_online_new; | |
2377 | ||
2378 | static void blk_mq_queue_reinit_work(void) | |
320ae51f JA |
2379 | { |
2380 | struct request_queue *q; | |
320ae51f JA |
2381 | |
2382 | mutex_lock(&all_q_mutex); | |
f3af020b TH |
2383 | /* |
2384 | * We need to freeze and reinit all existing queues. Freezing | |
2385 | * involves synchronous wait for an RCU grace period and doing it | |
2386 | * one by one may take a long time. Start freezing all queues in | |
2387 | * one swoop and then wait for the completions so that freezing can | |
2388 | * take place in parallel. | |
2389 | */ | |
2390 | list_for_each_entry(q, &all_q_list, all_q_node) | |
1671d522 | 2391 | blk_freeze_queue_start(q); |
415d3dab | 2392 | list_for_each_entry(q, &all_q_list, all_q_node) |
f3af020b TH |
2393 | blk_mq_freeze_queue_wait(q); |
2394 | ||
320ae51f | 2395 | list_for_each_entry(q, &all_q_list, all_q_node) |
65d5291e | 2396 | blk_mq_queue_reinit(q, &cpuhp_online_new); |
f3af020b TH |
2397 | |
2398 | list_for_each_entry(q, &all_q_list, all_q_node) | |
2399 | blk_mq_unfreeze_queue(q); | |
2400 | ||
320ae51f | 2401 | mutex_unlock(&all_q_mutex); |
65d5291e SAS |
2402 | } |
2403 | ||
2404 | static int blk_mq_queue_reinit_dead(unsigned int cpu) | |
2405 | { | |
97a32864 | 2406 | cpumask_copy(&cpuhp_online_new, cpu_online_mask); |
65d5291e SAS |
2407 | blk_mq_queue_reinit_work(); |
2408 | return 0; | |
2409 | } | |
2410 | ||
2411 | /* | |
2412 | * Before hotadded cpu starts handling requests, new mappings must be | |
2413 | * established. Otherwise, these requests in hw queue might never be | |
2414 | * dispatched. | |
2415 | * | |
2416 | * For example, there is a single hw queue (hctx) and two CPU queues (ctx0 | |
2417 | * for CPU0, and ctx1 for CPU1). | |
2418 | * | |
2419 | * Now CPU1 is just onlined and a request is inserted into ctx1->rq_list | |
2420 | * and set bit0 in pending bitmap as ctx1->index_hw is still zero. | |
2421 | * | |
2c3ad667 JA |
2422 | * And then while running hw queue, blk_mq_flush_busy_ctxs() finds bit0 is set |
2423 | * in pending bitmap and tries to retrieve requests in hctx->ctxs[0]->rq_list. | |
2424 | * But htx->ctxs[0] is a pointer to ctx0, so the request in ctx1->rq_list is | |
2425 | * ignored. | |
65d5291e SAS |
2426 | */ |
2427 | static int blk_mq_queue_reinit_prepare(unsigned int cpu) | |
2428 | { | |
2429 | cpumask_copy(&cpuhp_online_new, cpu_online_mask); | |
2430 | cpumask_set_cpu(cpu, &cpuhp_online_new); | |
2431 | blk_mq_queue_reinit_work(); | |
2432 | return 0; | |
320ae51f JA |
2433 | } |
2434 | ||
a5164405 JA |
2435 | static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) |
2436 | { | |
2437 | int i; | |
2438 | ||
cc71a6f4 JA |
2439 | for (i = 0; i < set->nr_hw_queues; i++) |
2440 | if (!__blk_mq_alloc_rq_map(set, i)) | |
a5164405 | 2441 | goto out_unwind; |
a5164405 JA |
2442 | |
2443 | return 0; | |
2444 | ||
2445 | out_unwind: | |
2446 | while (--i >= 0) | |
cc71a6f4 | 2447 | blk_mq_free_rq_map(set->tags[i]); |
a5164405 | 2448 | |
a5164405 JA |
2449 | return -ENOMEM; |
2450 | } | |
2451 | ||
2452 | /* | |
2453 | * Allocate the request maps associated with this tag_set. Note that this | |
2454 | * may reduce the depth asked for, if memory is tight. set->queue_depth | |
2455 | * will be updated to reflect the allocated depth. | |
2456 | */ | |
2457 | static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) | |
2458 | { | |
2459 | unsigned int depth; | |
2460 | int err; | |
2461 | ||
2462 | depth = set->queue_depth; | |
2463 | do { | |
2464 | err = __blk_mq_alloc_rq_maps(set); | |
2465 | if (!err) | |
2466 | break; | |
2467 | ||
2468 | set->queue_depth >>= 1; | |
2469 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) { | |
2470 | err = -ENOMEM; | |
2471 | break; | |
2472 | } | |
2473 | } while (set->queue_depth); | |
2474 | ||
2475 | if (!set->queue_depth || err) { | |
2476 | pr_err("blk-mq: failed to allocate request map\n"); | |
2477 | return -ENOMEM; | |
2478 | } | |
2479 | ||
2480 | if (depth != set->queue_depth) | |
2481 | pr_info("blk-mq: reduced tag depth (%u -> %u)\n", | |
2482 | depth, set->queue_depth); | |
2483 | ||
2484 | return 0; | |
2485 | } | |
2486 | ||
ebe8bddb OS |
2487 | static int blk_mq_update_queue_map(struct blk_mq_tag_set *set) |
2488 | { | |
2489 | if (set->ops->map_queues) | |
2490 | return set->ops->map_queues(set); | |
2491 | else | |
2492 | return blk_mq_map_queues(set); | |
2493 | } | |
2494 | ||
a4391c64 JA |
2495 | /* |
2496 | * Alloc a tag set to be associated with one or more request queues. | |
2497 | * May fail with EINVAL for various error conditions. May adjust the | |
2498 | * requested depth down, if if it too large. In that case, the set | |
2499 | * value will be stored in set->queue_depth. | |
2500 | */ | |
24d2f903 CH |
2501 | int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) |
2502 | { | |
da695ba2 CH |
2503 | int ret; |
2504 | ||
205fb5f5 BVA |
2505 | BUILD_BUG_ON(BLK_MQ_MAX_DEPTH > 1 << BLK_MQ_UNIQUE_TAG_BITS); |
2506 | ||
24d2f903 CH |
2507 | if (!set->nr_hw_queues) |
2508 | return -EINVAL; | |
a4391c64 | 2509 | if (!set->queue_depth) |
24d2f903 CH |
2510 | return -EINVAL; |
2511 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) | |
2512 | return -EINVAL; | |
2513 | ||
7d7e0f90 | 2514 | if (!set->ops->queue_rq) |
24d2f903 CH |
2515 | return -EINVAL; |
2516 | ||
a4391c64 JA |
2517 | if (set->queue_depth > BLK_MQ_MAX_DEPTH) { |
2518 | pr_info("blk-mq: reduced tag depth to %u\n", | |
2519 | BLK_MQ_MAX_DEPTH); | |
2520 | set->queue_depth = BLK_MQ_MAX_DEPTH; | |
2521 | } | |
24d2f903 | 2522 | |
6637fadf SL |
2523 | /* |
2524 | * If a crashdump is active, then we are potentially in a very | |
2525 | * memory constrained environment. Limit us to 1 queue and | |
2526 | * 64 tags to prevent using too much memory. | |
2527 | */ | |
2528 | if (is_kdump_kernel()) { | |
2529 | set->nr_hw_queues = 1; | |
2530 | set->queue_depth = min(64U, set->queue_depth); | |
2531 | } | |
868f2f0b KB |
2532 | /* |
2533 | * There is no use for more h/w queues than cpus. | |
2534 | */ | |
2535 | if (set->nr_hw_queues > nr_cpu_ids) | |
2536 | set->nr_hw_queues = nr_cpu_ids; | |
6637fadf | 2537 | |
868f2f0b | 2538 | set->tags = kzalloc_node(nr_cpu_ids * sizeof(struct blk_mq_tags *), |
24d2f903 CH |
2539 | GFP_KERNEL, set->numa_node); |
2540 | if (!set->tags) | |
a5164405 | 2541 | return -ENOMEM; |
24d2f903 | 2542 | |
da695ba2 CH |
2543 | ret = -ENOMEM; |
2544 | set->mq_map = kzalloc_node(sizeof(*set->mq_map) * nr_cpu_ids, | |
2545 | GFP_KERNEL, set->numa_node); | |
bdd17e75 CH |
2546 | if (!set->mq_map) |
2547 | goto out_free_tags; | |
2548 | ||
ebe8bddb | 2549 | ret = blk_mq_update_queue_map(set); |
da695ba2 CH |
2550 | if (ret) |
2551 | goto out_free_mq_map; | |
2552 | ||
2553 | ret = blk_mq_alloc_rq_maps(set); | |
2554 | if (ret) | |
bdd17e75 | 2555 | goto out_free_mq_map; |
24d2f903 | 2556 | |
0d2602ca JA |
2557 | mutex_init(&set->tag_list_lock); |
2558 | INIT_LIST_HEAD(&set->tag_list); | |
2559 | ||
24d2f903 | 2560 | return 0; |
bdd17e75 CH |
2561 | |
2562 | out_free_mq_map: | |
2563 | kfree(set->mq_map); | |
2564 | set->mq_map = NULL; | |
2565 | out_free_tags: | |
5676e7b6 RE |
2566 | kfree(set->tags); |
2567 | set->tags = NULL; | |
da695ba2 | 2568 | return ret; |
24d2f903 CH |
2569 | } |
2570 | EXPORT_SYMBOL(blk_mq_alloc_tag_set); | |
2571 | ||
2572 | void blk_mq_free_tag_set(struct blk_mq_tag_set *set) | |
2573 | { | |
2574 | int i; | |
2575 | ||
cc71a6f4 JA |
2576 | for (i = 0; i < nr_cpu_ids; i++) |
2577 | blk_mq_free_map_and_requests(set, i); | |
484b4061 | 2578 | |
bdd17e75 CH |
2579 | kfree(set->mq_map); |
2580 | set->mq_map = NULL; | |
2581 | ||
981bd189 | 2582 | kfree(set->tags); |
5676e7b6 | 2583 | set->tags = NULL; |
24d2f903 CH |
2584 | } |
2585 | EXPORT_SYMBOL(blk_mq_free_tag_set); | |
2586 | ||
e3a2b3f9 JA |
2587 | int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) |
2588 | { | |
2589 | struct blk_mq_tag_set *set = q->tag_set; | |
2590 | struct blk_mq_hw_ctx *hctx; | |
2591 | int i, ret; | |
2592 | ||
bd166ef1 | 2593 | if (!set) |
e3a2b3f9 JA |
2594 | return -EINVAL; |
2595 | ||
70f36b60 | 2596 | blk_mq_freeze_queue(q); |
70f36b60 | 2597 | |
e3a2b3f9 JA |
2598 | ret = 0; |
2599 | queue_for_each_hw_ctx(q, hctx, i) { | |
e9137d4b KB |
2600 | if (!hctx->tags) |
2601 | continue; | |
bd166ef1 JA |
2602 | /* |
2603 | * If we're using an MQ scheduler, just update the scheduler | |
2604 | * queue depth. This is similar to what the old code would do. | |
2605 | */ | |
70f36b60 JA |
2606 | if (!hctx->sched_tags) { |
2607 | ret = blk_mq_tag_update_depth(hctx, &hctx->tags, | |
2608 | min(nr, set->queue_depth), | |
2609 | false); | |
2610 | } else { | |
2611 | ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags, | |
2612 | nr, true); | |
2613 | } | |
e3a2b3f9 JA |
2614 | if (ret) |
2615 | break; | |
2616 | } | |
2617 | ||
2618 | if (!ret) | |
2619 | q->nr_requests = nr; | |
2620 | ||
70f36b60 | 2621 | blk_mq_unfreeze_queue(q); |
70f36b60 | 2622 | |
e3a2b3f9 JA |
2623 | return ret; |
2624 | } | |
2625 | ||
e4dc2b32 KB |
2626 | static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, |
2627 | int nr_hw_queues) | |
868f2f0b KB |
2628 | { |
2629 | struct request_queue *q; | |
2630 | ||
705cda97 BVA |
2631 | lockdep_assert_held(&set->tag_list_lock); |
2632 | ||
868f2f0b KB |
2633 | if (nr_hw_queues > nr_cpu_ids) |
2634 | nr_hw_queues = nr_cpu_ids; | |
2635 | if (nr_hw_queues < 1 || nr_hw_queues == set->nr_hw_queues) | |
2636 | return; | |
2637 | ||
2638 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
2639 | blk_mq_freeze_queue(q); | |
2640 | ||
2641 | set->nr_hw_queues = nr_hw_queues; | |
ebe8bddb | 2642 | blk_mq_update_queue_map(set); |
868f2f0b KB |
2643 | list_for_each_entry(q, &set->tag_list, tag_set_list) { |
2644 | blk_mq_realloc_hw_ctxs(set, q); | |
868f2f0b KB |
2645 | blk_mq_queue_reinit(q, cpu_online_mask); |
2646 | } | |
2647 | ||
2648 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
2649 | blk_mq_unfreeze_queue(q); | |
2650 | } | |
e4dc2b32 KB |
2651 | |
2652 | void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues) | |
2653 | { | |
2654 | mutex_lock(&set->tag_list_lock); | |
2655 | __blk_mq_update_nr_hw_queues(set, nr_hw_queues); | |
2656 | mutex_unlock(&set->tag_list_lock); | |
2657 | } | |
868f2f0b KB |
2658 | EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues); |
2659 | ||
34dbad5d OS |
2660 | /* Enable polling stats and return whether they were already enabled. */ |
2661 | static bool blk_poll_stats_enable(struct request_queue *q) | |
2662 | { | |
2663 | if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags) || | |
2664 | test_and_set_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags)) | |
2665 | return true; | |
2666 | blk_stat_add_callback(q, q->poll_cb); | |
2667 | return false; | |
2668 | } | |
2669 | ||
2670 | static void blk_mq_poll_stats_start(struct request_queue *q) | |
2671 | { | |
2672 | /* | |
2673 | * We don't arm the callback if polling stats are not enabled or the | |
2674 | * callback is already active. | |
2675 | */ | |
2676 | if (!test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags) || | |
2677 | blk_stat_is_active(q->poll_cb)) | |
2678 | return; | |
2679 | ||
2680 | blk_stat_activate_msecs(q->poll_cb, 100); | |
2681 | } | |
2682 | ||
2683 | static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb) | |
2684 | { | |
2685 | struct request_queue *q = cb->data; | |
720b8ccc | 2686 | int bucket; |
34dbad5d | 2687 | |
720b8ccc SB |
2688 | for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS; bucket++) { |
2689 | if (cb->stat[bucket].nr_samples) | |
2690 | q->poll_stat[bucket] = cb->stat[bucket]; | |
2691 | } | |
34dbad5d OS |
2692 | } |
2693 | ||
64f1c21e JA |
2694 | static unsigned long blk_mq_poll_nsecs(struct request_queue *q, |
2695 | struct blk_mq_hw_ctx *hctx, | |
2696 | struct request *rq) | |
2697 | { | |
64f1c21e | 2698 | unsigned long ret = 0; |
720b8ccc | 2699 | int bucket; |
64f1c21e JA |
2700 | |
2701 | /* | |
2702 | * If stats collection isn't on, don't sleep but turn it on for | |
2703 | * future users | |
2704 | */ | |
34dbad5d | 2705 | if (!blk_poll_stats_enable(q)) |
64f1c21e JA |
2706 | return 0; |
2707 | ||
64f1c21e JA |
2708 | /* |
2709 | * As an optimistic guess, use half of the mean service time | |
2710 | * for this type of request. We can (and should) make this smarter. | |
2711 | * For instance, if the completion latencies are tight, we can | |
2712 | * get closer than just half the mean. This is especially | |
2713 | * important on devices where the completion latencies are longer | |
720b8ccc SB |
2714 | * than ~10 usec. We do use the stats for the relevant IO size |
2715 | * if available which does lead to better estimates. | |
64f1c21e | 2716 | */ |
720b8ccc SB |
2717 | bucket = blk_mq_poll_stats_bkt(rq); |
2718 | if (bucket < 0) | |
2719 | return ret; | |
2720 | ||
2721 | if (q->poll_stat[bucket].nr_samples) | |
2722 | ret = (q->poll_stat[bucket].mean + 1) / 2; | |
64f1c21e JA |
2723 | |
2724 | return ret; | |
2725 | } | |
2726 | ||
06426adf | 2727 | static bool blk_mq_poll_hybrid_sleep(struct request_queue *q, |
64f1c21e | 2728 | struct blk_mq_hw_ctx *hctx, |
06426adf JA |
2729 | struct request *rq) |
2730 | { | |
2731 | struct hrtimer_sleeper hs; | |
2732 | enum hrtimer_mode mode; | |
64f1c21e | 2733 | unsigned int nsecs; |
06426adf JA |
2734 | ktime_t kt; |
2735 | ||
64f1c21e JA |
2736 | if (test_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags)) |
2737 | return false; | |
2738 | ||
2739 | /* | |
2740 | * poll_nsec can be: | |
2741 | * | |
2742 | * -1: don't ever hybrid sleep | |
2743 | * 0: use half of prev avg | |
2744 | * >0: use this specific value | |
2745 | */ | |
2746 | if (q->poll_nsec == -1) | |
2747 | return false; | |
2748 | else if (q->poll_nsec > 0) | |
2749 | nsecs = q->poll_nsec; | |
2750 | else | |
2751 | nsecs = blk_mq_poll_nsecs(q, hctx, rq); | |
2752 | ||
2753 | if (!nsecs) | |
06426adf JA |
2754 | return false; |
2755 | ||
2756 | set_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags); | |
2757 | ||
2758 | /* | |
2759 | * This will be replaced with the stats tracking code, using | |
2760 | * 'avg_completion_time / 2' as the pre-sleep target. | |
2761 | */ | |
8b0e1953 | 2762 | kt = nsecs; |
06426adf JA |
2763 | |
2764 | mode = HRTIMER_MODE_REL; | |
2765 | hrtimer_init_on_stack(&hs.timer, CLOCK_MONOTONIC, mode); | |
2766 | hrtimer_set_expires(&hs.timer, kt); | |
2767 | ||
2768 | hrtimer_init_sleeper(&hs, current); | |
2769 | do { | |
2770 | if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) | |
2771 | break; | |
2772 | set_current_state(TASK_UNINTERRUPTIBLE); | |
2773 | hrtimer_start_expires(&hs.timer, mode); | |
2774 | if (hs.task) | |
2775 | io_schedule(); | |
2776 | hrtimer_cancel(&hs.timer); | |
2777 | mode = HRTIMER_MODE_ABS; | |
2778 | } while (hs.task && !signal_pending(current)); | |
2779 | ||
2780 | __set_current_state(TASK_RUNNING); | |
2781 | destroy_hrtimer_on_stack(&hs.timer); | |
2782 | return true; | |
2783 | } | |
2784 | ||
bbd7bb70 JA |
2785 | static bool __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq) |
2786 | { | |
2787 | struct request_queue *q = hctx->queue; | |
2788 | long state; | |
2789 | ||
06426adf JA |
2790 | /* |
2791 | * If we sleep, have the caller restart the poll loop to reset | |
2792 | * the state. Like for the other success return cases, the | |
2793 | * caller is responsible for checking if the IO completed. If | |
2794 | * the IO isn't complete, we'll get called again and will go | |
2795 | * straight to the busy poll loop. | |
2796 | */ | |
64f1c21e | 2797 | if (blk_mq_poll_hybrid_sleep(q, hctx, rq)) |
06426adf JA |
2798 | return true; |
2799 | ||
bbd7bb70 JA |
2800 | hctx->poll_considered++; |
2801 | ||
2802 | state = current->state; | |
2803 | while (!need_resched()) { | |
2804 | int ret; | |
2805 | ||
2806 | hctx->poll_invoked++; | |
2807 | ||
2808 | ret = q->mq_ops->poll(hctx, rq->tag); | |
2809 | if (ret > 0) { | |
2810 | hctx->poll_success++; | |
2811 | set_current_state(TASK_RUNNING); | |
2812 | return true; | |
2813 | } | |
2814 | ||
2815 | if (signal_pending_state(state, current)) | |
2816 | set_current_state(TASK_RUNNING); | |
2817 | ||
2818 | if (current->state == TASK_RUNNING) | |
2819 | return true; | |
2820 | if (ret < 0) | |
2821 | break; | |
2822 | cpu_relax(); | |
2823 | } | |
2824 | ||
2825 | return false; | |
2826 | } | |
2827 | ||
2828 | bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie) | |
2829 | { | |
2830 | struct blk_mq_hw_ctx *hctx; | |
2831 | struct blk_plug *plug; | |
2832 | struct request *rq; | |
2833 | ||
2834 | if (!q->mq_ops || !q->mq_ops->poll || !blk_qc_t_valid(cookie) || | |
2835 | !test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) | |
2836 | return false; | |
2837 | ||
2838 | plug = current->plug; | |
2839 | if (plug) | |
2840 | blk_flush_plug_list(plug, false); | |
2841 | ||
2842 | hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)]; | |
bd166ef1 JA |
2843 | if (!blk_qc_t_is_internal(cookie)) |
2844 | rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie)); | |
3a07bb1d | 2845 | else { |
bd166ef1 | 2846 | rq = blk_mq_tag_to_rq(hctx->sched_tags, blk_qc_t_to_tag(cookie)); |
3a07bb1d JA |
2847 | /* |
2848 | * With scheduling, if the request has completed, we'll | |
2849 | * get a NULL return here, as we clear the sched tag when | |
2850 | * that happens. The request still remains valid, like always, | |
2851 | * so we should be safe with just the NULL check. | |
2852 | */ | |
2853 | if (!rq) | |
2854 | return false; | |
2855 | } | |
bbd7bb70 JA |
2856 | |
2857 | return __blk_mq_poll(hctx, rq); | |
2858 | } | |
2859 | EXPORT_SYMBOL_GPL(blk_mq_poll); | |
2860 | ||
676141e4 JA |
2861 | void blk_mq_disable_hotplug(void) |
2862 | { | |
2863 | mutex_lock(&all_q_mutex); | |
2864 | } | |
2865 | ||
2866 | void blk_mq_enable_hotplug(void) | |
2867 | { | |
2868 | mutex_unlock(&all_q_mutex); | |
2869 | } | |
2870 | ||
320ae51f JA |
2871 | static int __init blk_mq_init(void) |
2872 | { | |
9467f859 TG |
2873 | cpuhp_setup_state_multi(CPUHP_BLK_MQ_DEAD, "block/mq:dead", NULL, |
2874 | blk_mq_hctx_notify_dead); | |
320ae51f | 2875 | |
65d5291e SAS |
2876 | cpuhp_setup_state_nocalls(CPUHP_BLK_MQ_PREPARE, "block/mq:prepare", |
2877 | blk_mq_queue_reinit_prepare, | |
2878 | blk_mq_queue_reinit_dead); | |
320ae51f JA |
2879 | return 0; |
2880 | } | |
2881 | subsys_initcall(blk_mq_init); |