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Commit | Line | Data |
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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" | |
34 | #include "blk-mq-tag.h" | |
cf43e6be | 35 | #include "blk-stat.h" |
87760e5e | 36 | #include "blk-wbt.h" |
bd166ef1 | 37 | #include "blk-mq-sched.h" |
320ae51f JA |
38 | |
39 | static DEFINE_MUTEX(all_q_mutex); | |
40 | static LIST_HEAD(all_q_list); | |
41 | ||
34dbad5d OS |
42 | static void blk_mq_poll_stats_start(struct request_queue *q); |
43 | static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb); | |
44 | ||
320ae51f JA |
45 | /* |
46 | * Check if any of the ctx's have pending work in this hardware queue | |
47 | */ | |
50e1dab8 | 48 | bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx) |
320ae51f | 49 | { |
bd166ef1 JA |
50 | return sbitmap_any_bit_set(&hctx->ctx_map) || |
51 | !list_empty_careful(&hctx->dispatch) || | |
52 | blk_mq_sched_has_work(hctx); | |
1429d7c9 JA |
53 | } |
54 | ||
320ae51f JA |
55 | /* |
56 | * Mark this ctx as having pending work in this hardware queue | |
57 | */ | |
58 | static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx, | |
59 | struct blk_mq_ctx *ctx) | |
60 | { | |
88459642 OS |
61 | if (!sbitmap_test_bit(&hctx->ctx_map, ctx->index_hw)) |
62 | sbitmap_set_bit(&hctx->ctx_map, ctx->index_hw); | |
1429d7c9 JA |
63 | } |
64 | ||
65 | static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx, | |
66 | struct blk_mq_ctx *ctx) | |
67 | { | |
88459642 | 68 | sbitmap_clear_bit(&hctx->ctx_map, ctx->index_hw); |
320ae51f JA |
69 | } |
70 | ||
1671d522 | 71 | void blk_freeze_queue_start(struct request_queue *q) |
43a5e4e2 | 72 | { |
4ecd4fef | 73 | int freeze_depth; |
cddd5d17 | 74 | |
4ecd4fef CH |
75 | freeze_depth = atomic_inc_return(&q->mq_freeze_depth); |
76 | if (freeze_depth == 1) { | |
3ef28e83 | 77 | percpu_ref_kill(&q->q_usage_counter); |
b94ec296 | 78 | blk_mq_run_hw_queues(q, false); |
cddd5d17 | 79 | } |
f3af020b | 80 | } |
1671d522 | 81 | EXPORT_SYMBOL_GPL(blk_freeze_queue_start); |
f3af020b | 82 | |
6bae363e | 83 | void blk_mq_freeze_queue_wait(struct request_queue *q) |
f3af020b | 84 | { |
3ef28e83 | 85 | wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter)); |
43a5e4e2 | 86 | } |
6bae363e | 87 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait); |
43a5e4e2 | 88 | |
f91328c4 KB |
89 | int blk_mq_freeze_queue_wait_timeout(struct request_queue *q, |
90 | unsigned long timeout) | |
91 | { | |
92 | return wait_event_timeout(q->mq_freeze_wq, | |
93 | percpu_ref_is_zero(&q->q_usage_counter), | |
94 | timeout); | |
95 | } | |
96 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait_timeout); | |
43a5e4e2 | 97 | |
f3af020b TH |
98 | /* |
99 | * Guarantee no request is in use, so we can change any data structure of | |
100 | * the queue afterward. | |
101 | */ | |
3ef28e83 | 102 | void blk_freeze_queue(struct request_queue *q) |
f3af020b | 103 | { |
3ef28e83 DW |
104 | /* |
105 | * In the !blk_mq case we are only calling this to kill the | |
106 | * q_usage_counter, otherwise this increases the freeze depth | |
107 | * and waits for it to return to zero. For this reason there is | |
108 | * no blk_unfreeze_queue(), and blk_freeze_queue() is not | |
109 | * exported to drivers as the only user for unfreeze is blk_mq. | |
110 | */ | |
1671d522 | 111 | blk_freeze_queue_start(q); |
f3af020b TH |
112 | blk_mq_freeze_queue_wait(q); |
113 | } | |
3ef28e83 DW |
114 | |
115 | void blk_mq_freeze_queue(struct request_queue *q) | |
116 | { | |
117 | /* | |
118 | * ...just an alias to keep freeze and unfreeze actions balanced | |
119 | * in the blk_mq_* namespace | |
120 | */ | |
121 | blk_freeze_queue(q); | |
122 | } | |
c761d96b | 123 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue); |
f3af020b | 124 | |
b4c6a028 | 125 | void blk_mq_unfreeze_queue(struct request_queue *q) |
320ae51f | 126 | { |
4ecd4fef | 127 | int freeze_depth; |
320ae51f | 128 | |
4ecd4fef CH |
129 | freeze_depth = atomic_dec_return(&q->mq_freeze_depth); |
130 | WARN_ON_ONCE(freeze_depth < 0); | |
131 | if (!freeze_depth) { | |
3ef28e83 | 132 | percpu_ref_reinit(&q->q_usage_counter); |
320ae51f | 133 | wake_up_all(&q->mq_freeze_wq); |
add703fd | 134 | } |
320ae51f | 135 | } |
b4c6a028 | 136 | EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue); |
320ae51f | 137 | |
6a83e74d BVA |
138 | /** |
139 | * blk_mq_quiesce_queue() - wait until all ongoing queue_rq calls have finished | |
140 | * @q: request queue. | |
141 | * | |
142 | * Note: this function does not prevent that the struct request end_io() | |
143 | * callback function is invoked. Additionally, it is not prevented that | |
144 | * new queue_rq() calls occur unless the queue has been stopped first. | |
145 | */ | |
146 | void blk_mq_quiesce_queue(struct request_queue *q) | |
147 | { | |
148 | struct blk_mq_hw_ctx *hctx; | |
149 | unsigned int i; | |
150 | bool rcu = false; | |
151 | ||
152 | blk_mq_stop_hw_queues(q); | |
153 | ||
154 | queue_for_each_hw_ctx(q, hctx, i) { | |
155 | if (hctx->flags & BLK_MQ_F_BLOCKING) | |
156 | synchronize_srcu(&hctx->queue_rq_srcu); | |
157 | else | |
158 | rcu = true; | |
159 | } | |
160 | if (rcu) | |
161 | synchronize_rcu(); | |
162 | } | |
163 | EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue); | |
164 | ||
aed3ea94 JA |
165 | void blk_mq_wake_waiters(struct request_queue *q) |
166 | { | |
167 | struct blk_mq_hw_ctx *hctx; | |
168 | unsigned int i; | |
169 | ||
170 | queue_for_each_hw_ctx(q, hctx, i) | |
171 | if (blk_mq_hw_queue_mapped(hctx)) | |
172 | blk_mq_tag_wakeup_all(hctx->tags, true); | |
3fd5940c KB |
173 | |
174 | /* | |
175 | * If we are called because the queue has now been marked as | |
176 | * dying, we need to ensure that processes currently waiting on | |
177 | * the queue are notified as well. | |
178 | */ | |
179 | wake_up_all(&q->mq_freeze_wq); | |
aed3ea94 JA |
180 | } |
181 | ||
320ae51f JA |
182 | bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx) |
183 | { | |
184 | return blk_mq_has_free_tags(hctx->tags); | |
185 | } | |
186 | EXPORT_SYMBOL(blk_mq_can_queue); | |
187 | ||
2c3ad667 JA |
188 | void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, |
189 | struct request *rq, unsigned int op) | |
320ae51f | 190 | { |
af76e555 CH |
191 | INIT_LIST_HEAD(&rq->queuelist); |
192 | /* csd/requeue_work/fifo_time is initialized before use */ | |
193 | rq->q = q; | |
320ae51f | 194 | rq->mq_ctx = ctx; |
ef295ecf | 195 | rq->cmd_flags = op; |
e8064021 CH |
196 | if (blk_queue_io_stat(q)) |
197 | rq->rq_flags |= RQF_IO_STAT; | |
af76e555 CH |
198 | /* do not touch atomic flags, it needs atomic ops against the timer */ |
199 | rq->cpu = -1; | |
af76e555 CH |
200 | INIT_HLIST_NODE(&rq->hash); |
201 | RB_CLEAR_NODE(&rq->rb_node); | |
af76e555 CH |
202 | rq->rq_disk = NULL; |
203 | rq->part = NULL; | |
3ee32372 | 204 | rq->start_time = jiffies; |
af76e555 CH |
205 | #ifdef CONFIG_BLK_CGROUP |
206 | rq->rl = NULL; | |
0fec08b4 | 207 | set_start_time_ns(rq); |
af76e555 CH |
208 | rq->io_start_time_ns = 0; |
209 | #endif | |
210 | rq->nr_phys_segments = 0; | |
211 | #if defined(CONFIG_BLK_DEV_INTEGRITY) | |
212 | rq->nr_integrity_segments = 0; | |
213 | #endif | |
af76e555 CH |
214 | rq->special = NULL; |
215 | /* tag was already set */ | |
af76e555 | 216 | rq->extra_len = 0; |
af76e555 | 217 | |
af76e555 | 218 | INIT_LIST_HEAD(&rq->timeout_list); |
f6be4fb4 JA |
219 | rq->timeout = 0; |
220 | ||
af76e555 CH |
221 | rq->end_io = NULL; |
222 | rq->end_io_data = NULL; | |
223 | rq->next_rq = NULL; | |
224 | ||
ef295ecf | 225 | ctx->rq_dispatched[op_is_sync(op)]++; |
320ae51f | 226 | } |
2c3ad667 | 227 | EXPORT_SYMBOL_GPL(blk_mq_rq_ctx_init); |
320ae51f | 228 | |
2c3ad667 JA |
229 | struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data, |
230 | unsigned int op) | |
5dee8577 CH |
231 | { |
232 | struct request *rq; | |
233 | unsigned int tag; | |
234 | ||
cb96a42c | 235 | tag = blk_mq_get_tag(data); |
5dee8577 | 236 | if (tag != BLK_MQ_TAG_FAIL) { |
bd166ef1 JA |
237 | struct blk_mq_tags *tags = blk_mq_tags_from_data(data); |
238 | ||
239 | rq = tags->static_rqs[tag]; | |
5dee8577 | 240 | |
bd166ef1 JA |
241 | if (data->flags & BLK_MQ_REQ_INTERNAL) { |
242 | rq->tag = -1; | |
243 | rq->internal_tag = tag; | |
244 | } else { | |
200e86b3 JA |
245 | if (blk_mq_tag_busy(data->hctx)) { |
246 | rq->rq_flags = RQF_MQ_INFLIGHT; | |
247 | atomic_inc(&data->hctx->nr_active); | |
248 | } | |
bd166ef1 JA |
249 | rq->tag = tag; |
250 | rq->internal_tag = -1; | |
562bef42 | 251 | data->hctx->tags->rqs[rq->tag] = rq; |
bd166ef1 JA |
252 | } |
253 | ||
ef295ecf | 254 | blk_mq_rq_ctx_init(data->q, data->ctx, rq, op); |
5dee8577 CH |
255 | return rq; |
256 | } | |
257 | ||
258 | return NULL; | |
259 | } | |
2c3ad667 | 260 | EXPORT_SYMBOL_GPL(__blk_mq_alloc_request); |
5dee8577 | 261 | |
6f3b0e8b CH |
262 | struct request *blk_mq_alloc_request(struct request_queue *q, int rw, |
263 | unsigned int flags) | |
320ae51f | 264 | { |
5a797e00 | 265 | struct blk_mq_alloc_data alloc_data = { .flags = flags }; |
bd166ef1 | 266 | struct request *rq; |
a492f075 | 267 | int ret; |
320ae51f | 268 | |
6f3b0e8b | 269 | ret = blk_queue_enter(q, flags & BLK_MQ_REQ_NOWAIT); |
a492f075 JL |
270 | if (ret) |
271 | return ERR_PTR(ret); | |
320ae51f | 272 | |
bd166ef1 | 273 | rq = blk_mq_sched_get_request(q, NULL, rw, &alloc_data); |
841bac2c | 274 | |
bd166ef1 JA |
275 | blk_mq_put_ctx(alloc_data.ctx); |
276 | blk_queue_exit(q); | |
277 | ||
278 | if (!rq) | |
a492f075 | 279 | return ERR_PTR(-EWOULDBLOCK); |
0c4de0f3 CH |
280 | |
281 | rq->__data_len = 0; | |
282 | rq->__sector = (sector_t) -1; | |
283 | rq->bio = rq->biotail = NULL; | |
320ae51f JA |
284 | return rq; |
285 | } | |
4bb659b1 | 286 | EXPORT_SYMBOL(blk_mq_alloc_request); |
320ae51f | 287 | |
1f5bd336 ML |
288 | struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int rw, |
289 | unsigned int flags, unsigned int hctx_idx) | |
290 | { | |
6d2809d5 | 291 | struct blk_mq_alloc_data alloc_data = { .flags = flags }; |
1f5bd336 | 292 | struct request *rq; |
6d2809d5 | 293 | unsigned int cpu; |
1f5bd336 ML |
294 | int ret; |
295 | ||
296 | /* | |
297 | * If the tag allocator sleeps we could get an allocation for a | |
298 | * different hardware context. No need to complicate the low level | |
299 | * allocator for this for the rare use case of a command tied to | |
300 | * a specific queue. | |
301 | */ | |
302 | if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT))) | |
303 | return ERR_PTR(-EINVAL); | |
304 | ||
305 | if (hctx_idx >= q->nr_hw_queues) | |
306 | return ERR_PTR(-EIO); | |
307 | ||
308 | ret = blk_queue_enter(q, true); | |
309 | if (ret) | |
310 | return ERR_PTR(ret); | |
311 | ||
c8712c6a CH |
312 | /* |
313 | * Check if the hardware context is actually mapped to anything. | |
314 | * If not tell the caller that it should skip this queue. | |
315 | */ | |
6d2809d5 OS |
316 | alloc_data.hctx = q->queue_hw_ctx[hctx_idx]; |
317 | if (!blk_mq_hw_queue_mapped(alloc_data.hctx)) { | |
318 | blk_queue_exit(q); | |
319 | return ERR_PTR(-EXDEV); | |
c8712c6a | 320 | } |
6d2809d5 OS |
321 | cpu = cpumask_first(alloc_data.hctx->cpumask); |
322 | alloc_data.ctx = __blk_mq_get_ctx(q, cpu); | |
1f5bd336 | 323 | |
6d2809d5 | 324 | rq = blk_mq_sched_get_request(q, NULL, rw, &alloc_data); |
c8712c6a | 325 | |
c8712c6a | 326 | blk_queue_exit(q); |
6d2809d5 OS |
327 | |
328 | if (!rq) | |
329 | return ERR_PTR(-EWOULDBLOCK); | |
330 | ||
331 | return rq; | |
1f5bd336 ML |
332 | } |
333 | EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx); | |
334 | ||
bd166ef1 JA |
335 | void __blk_mq_finish_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, |
336 | struct request *rq) | |
320ae51f | 337 | { |
bd166ef1 | 338 | const int sched_tag = rq->internal_tag; |
320ae51f JA |
339 | struct request_queue *q = rq->q; |
340 | ||
e8064021 | 341 | if (rq->rq_flags & RQF_MQ_INFLIGHT) |
0d2602ca | 342 | atomic_dec(&hctx->nr_active); |
87760e5e JA |
343 | |
344 | wbt_done(q->rq_wb, &rq->issue_stat); | |
e8064021 | 345 | rq->rq_flags = 0; |
0d2602ca | 346 | |
af76e555 | 347 | clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); |
06426adf | 348 | clear_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags); |
bd166ef1 JA |
349 | if (rq->tag != -1) |
350 | blk_mq_put_tag(hctx, hctx->tags, ctx, rq->tag); | |
351 | if (sched_tag != -1) | |
c05f8525 | 352 | blk_mq_put_tag(hctx, hctx->sched_tags, ctx, sched_tag); |
6d8c6c0f | 353 | blk_mq_sched_restart(hctx); |
3ef28e83 | 354 | blk_queue_exit(q); |
320ae51f JA |
355 | } |
356 | ||
bd166ef1 | 357 | static void blk_mq_finish_hctx_request(struct blk_mq_hw_ctx *hctx, |
16a3c2a7 | 358 | struct request *rq) |
320ae51f JA |
359 | { |
360 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
320ae51f JA |
361 | |
362 | ctx->rq_completed[rq_is_sync(rq)]++; | |
bd166ef1 JA |
363 | __blk_mq_finish_request(hctx, ctx, rq); |
364 | } | |
365 | ||
366 | void blk_mq_finish_request(struct request *rq) | |
367 | { | |
368 | blk_mq_finish_hctx_request(blk_mq_map_queue(rq->q, rq->mq_ctx->cpu), rq); | |
7c7f2f2b | 369 | } |
5b727272 | 370 | EXPORT_SYMBOL_GPL(blk_mq_finish_request); |
7c7f2f2b JA |
371 | |
372 | void blk_mq_free_request(struct request *rq) | |
373 | { | |
bd166ef1 | 374 | blk_mq_sched_put_request(rq); |
320ae51f | 375 | } |
1a3b595a | 376 | EXPORT_SYMBOL_GPL(blk_mq_free_request); |
320ae51f | 377 | |
c8a446ad | 378 | inline void __blk_mq_end_request(struct request *rq, int error) |
320ae51f | 379 | { |
0d11e6ac ML |
380 | blk_account_io_done(rq); |
381 | ||
91b63639 | 382 | if (rq->end_io) { |
87760e5e | 383 | wbt_done(rq->q->rq_wb, &rq->issue_stat); |
320ae51f | 384 | rq->end_io(rq, error); |
91b63639 CH |
385 | } else { |
386 | if (unlikely(blk_bidi_rq(rq))) | |
387 | blk_mq_free_request(rq->next_rq); | |
320ae51f | 388 | blk_mq_free_request(rq); |
91b63639 | 389 | } |
320ae51f | 390 | } |
c8a446ad | 391 | EXPORT_SYMBOL(__blk_mq_end_request); |
63151a44 | 392 | |
c8a446ad | 393 | void blk_mq_end_request(struct request *rq, int error) |
63151a44 CH |
394 | { |
395 | if (blk_update_request(rq, error, blk_rq_bytes(rq))) | |
396 | BUG(); | |
c8a446ad | 397 | __blk_mq_end_request(rq, error); |
63151a44 | 398 | } |
c8a446ad | 399 | EXPORT_SYMBOL(blk_mq_end_request); |
320ae51f | 400 | |
30a91cb4 | 401 | static void __blk_mq_complete_request_remote(void *data) |
320ae51f | 402 | { |
3d6efbf6 | 403 | struct request *rq = data; |
320ae51f | 404 | |
30a91cb4 | 405 | rq->q->softirq_done_fn(rq); |
320ae51f | 406 | } |
320ae51f | 407 | |
453f8341 | 408 | static void __blk_mq_complete_request(struct request *rq) |
320ae51f JA |
409 | { |
410 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
38535201 | 411 | bool shared = false; |
320ae51f JA |
412 | int cpu; |
413 | ||
453f8341 CH |
414 | if (rq->internal_tag != -1) |
415 | blk_mq_sched_completed_request(rq); | |
416 | if (rq->rq_flags & RQF_STATS) { | |
417 | blk_mq_poll_stats_start(rq->q); | |
418 | blk_stat_add(rq); | |
419 | } | |
420 | ||
38535201 | 421 | if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) { |
30a91cb4 CH |
422 | rq->q->softirq_done_fn(rq); |
423 | return; | |
424 | } | |
320ae51f JA |
425 | |
426 | cpu = get_cpu(); | |
38535201 CH |
427 | if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags)) |
428 | shared = cpus_share_cache(cpu, ctx->cpu); | |
429 | ||
430 | if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) { | |
30a91cb4 | 431 | rq->csd.func = __blk_mq_complete_request_remote; |
3d6efbf6 CH |
432 | rq->csd.info = rq; |
433 | rq->csd.flags = 0; | |
c46fff2a | 434 | smp_call_function_single_async(ctx->cpu, &rq->csd); |
3d6efbf6 | 435 | } else { |
30a91cb4 | 436 | rq->q->softirq_done_fn(rq); |
3d6efbf6 | 437 | } |
320ae51f JA |
438 | put_cpu(); |
439 | } | |
30a91cb4 CH |
440 | |
441 | /** | |
442 | * blk_mq_complete_request - end I/O on a request | |
443 | * @rq: the request being processed | |
444 | * | |
445 | * Description: | |
446 | * Ends all I/O on a request. It does not handle partial completions. | |
447 | * The actual completion happens out-of-order, through a IPI handler. | |
448 | **/ | |
08e0029a | 449 | void blk_mq_complete_request(struct request *rq) |
30a91cb4 | 450 | { |
95f09684 JA |
451 | struct request_queue *q = rq->q; |
452 | ||
453 | if (unlikely(blk_should_fake_timeout(q))) | |
30a91cb4 | 454 | return; |
08e0029a | 455 | if (!blk_mark_rq_complete(rq)) |
ed851860 | 456 | __blk_mq_complete_request(rq); |
30a91cb4 CH |
457 | } |
458 | EXPORT_SYMBOL(blk_mq_complete_request); | |
320ae51f | 459 | |
973c0191 KB |
460 | int blk_mq_request_started(struct request *rq) |
461 | { | |
462 | return test_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
463 | } | |
464 | EXPORT_SYMBOL_GPL(blk_mq_request_started); | |
465 | ||
e2490073 | 466 | void blk_mq_start_request(struct request *rq) |
320ae51f JA |
467 | { |
468 | struct request_queue *q = rq->q; | |
469 | ||
bd166ef1 JA |
470 | blk_mq_sched_started_request(rq); |
471 | ||
320ae51f JA |
472 | trace_block_rq_issue(q, rq); |
473 | ||
cf43e6be | 474 | if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags)) { |
88eeca49 | 475 | blk_stat_set_issue(&rq->issue_stat, blk_rq_sectors(rq)); |
cf43e6be | 476 | rq->rq_flags |= RQF_STATS; |
87760e5e | 477 | wbt_issue(q->rq_wb, &rq->issue_stat); |
cf43e6be JA |
478 | } |
479 | ||
2b8393b4 | 480 | blk_add_timer(rq); |
87ee7b11 | 481 | |
538b7534 JA |
482 | /* |
483 | * Ensure that ->deadline is visible before set the started | |
484 | * flag and clear the completed flag. | |
485 | */ | |
486 | smp_mb__before_atomic(); | |
487 | ||
87ee7b11 JA |
488 | /* |
489 | * Mark us as started and clear complete. Complete might have been | |
490 | * set if requeue raced with timeout, which then marked it as | |
491 | * complete. So be sure to clear complete again when we start | |
492 | * the request, otherwise we'll ignore the completion event. | |
493 | */ | |
4b570521 JA |
494 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) |
495 | set_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
496 | if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) | |
497 | clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); | |
49f5baa5 CH |
498 | |
499 | if (q->dma_drain_size && blk_rq_bytes(rq)) { | |
500 | /* | |
501 | * Make sure space for the drain appears. We know we can do | |
502 | * this because max_hw_segments has been adjusted to be one | |
503 | * fewer than the device can handle. | |
504 | */ | |
505 | rq->nr_phys_segments++; | |
506 | } | |
320ae51f | 507 | } |
e2490073 | 508 | EXPORT_SYMBOL(blk_mq_start_request); |
320ae51f | 509 | |
d9d149a3 ML |
510 | /* |
511 | * When we reach here because queue is busy, REQ_ATOM_COMPLETE | |
48b99c9d | 512 | * flag isn't set yet, so there may be race with timeout handler, |
d9d149a3 ML |
513 | * but given rq->deadline is just set in .queue_rq() under |
514 | * this situation, the race won't be possible in reality because | |
515 | * rq->timeout should be set as big enough to cover the window | |
516 | * between blk_mq_start_request() called from .queue_rq() and | |
517 | * clearing REQ_ATOM_STARTED here. | |
518 | */ | |
ed0791b2 | 519 | static void __blk_mq_requeue_request(struct request *rq) |
320ae51f JA |
520 | { |
521 | struct request_queue *q = rq->q; | |
522 | ||
523 | trace_block_rq_requeue(q, rq); | |
87760e5e | 524 | wbt_requeue(q->rq_wb, &rq->issue_stat); |
bd166ef1 | 525 | blk_mq_sched_requeue_request(rq); |
49f5baa5 | 526 | |
e2490073 CH |
527 | if (test_and_clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) { |
528 | if (q->dma_drain_size && blk_rq_bytes(rq)) | |
529 | rq->nr_phys_segments--; | |
530 | } | |
320ae51f JA |
531 | } |
532 | ||
2b053aca | 533 | void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list) |
ed0791b2 | 534 | { |
ed0791b2 | 535 | __blk_mq_requeue_request(rq); |
ed0791b2 | 536 | |
ed0791b2 | 537 | BUG_ON(blk_queued_rq(rq)); |
2b053aca | 538 | blk_mq_add_to_requeue_list(rq, true, kick_requeue_list); |
ed0791b2 CH |
539 | } |
540 | EXPORT_SYMBOL(blk_mq_requeue_request); | |
541 | ||
6fca6a61 CH |
542 | static void blk_mq_requeue_work(struct work_struct *work) |
543 | { | |
544 | struct request_queue *q = | |
2849450a | 545 | container_of(work, struct request_queue, requeue_work.work); |
6fca6a61 CH |
546 | LIST_HEAD(rq_list); |
547 | struct request *rq, *next; | |
548 | unsigned long flags; | |
549 | ||
550 | spin_lock_irqsave(&q->requeue_lock, flags); | |
551 | list_splice_init(&q->requeue_list, &rq_list); | |
552 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
553 | ||
554 | list_for_each_entry_safe(rq, next, &rq_list, queuelist) { | |
e8064021 | 555 | if (!(rq->rq_flags & RQF_SOFTBARRIER)) |
6fca6a61 CH |
556 | continue; |
557 | ||
e8064021 | 558 | rq->rq_flags &= ~RQF_SOFTBARRIER; |
6fca6a61 | 559 | list_del_init(&rq->queuelist); |
bd6737f1 | 560 | blk_mq_sched_insert_request(rq, true, false, false, true); |
6fca6a61 CH |
561 | } |
562 | ||
563 | while (!list_empty(&rq_list)) { | |
564 | rq = list_entry(rq_list.next, struct request, queuelist); | |
565 | list_del_init(&rq->queuelist); | |
bd6737f1 | 566 | blk_mq_sched_insert_request(rq, false, false, false, true); |
6fca6a61 CH |
567 | } |
568 | ||
52d7f1b5 | 569 | blk_mq_run_hw_queues(q, false); |
6fca6a61 CH |
570 | } |
571 | ||
2b053aca BVA |
572 | void blk_mq_add_to_requeue_list(struct request *rq, bool at_head, |
573 | bool kick_requeue_list) | |
6fca6a61 CH |
574 | { |
575 | struct request_queue *q = rq->q; | |
576 | unsigned long flags; | |
577 | ||
578 | /* | |
579 | * We abuse this flag that is otherwise used by the I/O scheduler to | |
580 | * request head insertation from the workqueue. | |
581 | */ | |
e8064021 | 582 | BUG_ON(rq->rq_flags & RQF_SOFTBARRIER); |
6fca6a61 CH |
583 | |
584 | spin_lock_irqsave(&q->requeue_lock, flags); | |
585 | if (at_head) { | |
e8064021 | 586 | rq->rq_flags |= RQF_SOFTBARRIER; |
6fca6a61 CH |
587 | list_add(&rq->queuelist, &q->requeue_list); |
588 | } else { | |
589 | list_add_tail(&rq->queuelist, &q->requeue_list); | |
590 | } | |
591 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
2b053aca BVA |
592 | |
593 | if (kick_requeue_list) | |
594 | blk_mq_kick_requeue_list(q); | |
6fca6a61 CH |
595 | } |
596 | EXPORT_SYMBOL(blk_mq_add_to_requeue_list); | |
597 | ||
598 | void blk_mq_kick_requeue_list(struct request_queue *q) | |
599 | { | |
2849450a | 600 | kblockd_schedule_delayed_work(&q->requeue_work, 0); |
6fca6a61 CH |
601 | } |
602 | EXPORT_SYMBOL(blk_mq_kick_requeue_list); | |
603 | ||
2849450a MS |
604 | void blk_mq_delay_kick_requeue_list(struct request_queue *q, |
605 | unsigned long msecs) | |
606 | { | |
607 | kblockd_schedule_delayed_work(&q->requeue_work, | |
608 | msecs_to_jiffies(msecs)); | |
609 | } | |
610 | EXPORT_SYMBOL(blk_mq_delay_kick_requeue_list); | |
611 | ||
1885b24d JA |
612 | void blk_mq_abort_requeue_list(struct request_queue *q) |
613 | { | |
614 | unsigned long flags; | |
615 | LIST_HEAD(rq_list); | |
616 | ||
617 | spin_lock_irqsave(&q->requeue_lock, flags); | |
618 | list_splice_init(&q->requeue_list, &rq_list); | |
619 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
620 | ||
621 | while (!list_empty(&rq_list)) { | |
622 | struct request *rq; | |
623 | ||
624 | rq = list_first_entry(&rq_list, struct request, queuelist); | |
625 | list_del_init(&rq->queuelist); | |
caf7df12 | 626 | blk_mq_end_request(rq, -EIO); |
1885b24d JA |
627 | } |
628 | } | |
629 | EXPORT_SYMBOL(blk_mq_abort_requeue_list); | |
630 | ||
0e62f51f JA |
631 | struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag) |
632 | { | |
88c7b2b7 JA |
633 | if (tag < tags->nr_tags) { |
634 | prefetch(tags->rqs[tag]); | |
4ee86bab | 635 | return tags->rqs[tag]; |
88c7b2b7 | 636 | } |
4ee86bab HR |
637 | |
638 | return NULL; | |
24d2f903 CH |
639 | } |
640 | EXPORT_SYMBOL(blk_mq_tag_to_rq); | |
641 | ||
320ae51f | 642 | struct blk_mq_timeout_data { |
46f92d42 CH |
643 | unsigned long next; |
644 | unsigned int next_set; | |
320ae51f JA |
645 | }; |
646 | ||
90415837 | 647 | void blk_mq_rq_timed_out(struct request *req, bool reserved) |
320ae51f | 648 | { |
f8a5b122 | 649 | const struct blk_mq_ops *ops = req->q->mq_ops; |
46f92d42 | 650 | enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER; |
87ee7b11 JA |
651 | |
652 | /* | |
653 | * We know that complete is set at this point. If STARTED isn't set | |
654 | * anymore, then the request isn't active and the "timeout" should | |
655 | * just be ignored. This can happen due to the bitflag ordering. | |
656 | * Timeout first checks if STARTED is set, and if it is, assumes | |
657 | * the request is active. But if we race with completion, then | |
48b99c9d | 658 | * both flags will get cleared. So check here again, and ignore |
87ee7b11 JA |
659 | * a timeout event with a request that isn't active. |
660 | */ | |
46f92d42 CH |
661 | if (!test_bit(REQ_ATOM_STARTED, &req->atomic_flags)) |
662 | return; | |
87ee7b11 | 663 | |
46f92d42 | 664 | if (ops->timeout) |
0152fb6b | 665 | ret = ops->timeout(req, reserved); |
46f92d42 CH |
666 | |
667 | switch (ret) { | |
668 | case BLK_EH_HANDLED: | |
669 | __blk_mq_complete_request(req); | |
670 | break; | |
671 | case BLK_EH_RESET_TIMER: | |
672 | blk_add_timer(req); | |
673 | blk_clear_rq_complete(req); | |
674 | break; | |
675 | case BLK_EH_NOT_HANDLED: | |
676 | break; | |
677 | default: | |
678 | printk(KERN_ERR "block: bad eh return: %d\n", ret); | |
679 | break; | |
680 | } | |
87ee7b11 | 681 | } |
5b3f25fc | 682 | |
81481eb4 CH |
683 | static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx, |
684 | struct request *rq, void *priv, bool reserved) | |
685 | { | |
686 | struct blk_mq_timeout_data *data = priv; | |
87ee7b11 | 687 | |
a4ef8e56 | 688 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) |
46f92d42 | 689 | return; |
87ee7b11 | 690 | |
d9d149a3 ML |
691 | /* |
692 | * The rq being checked may have been freed and reallocated | |
693 | * out already here, we avoid this race by checking rq->deadline | |
694 | * and REQ_ATOM_COMPLETE flag together: | |
695 | * | |
696 | * - if rq->deadline is observed as new value because of | |
697 | * reusing, the rq won't be timed out because of timing. | |
698 | * - if rq->deadline is observed as previous value, | |
699 | * REQ_ATOM_COMPLETE flag won't be cleared in reuse path | |
700 | * because we put a barrier between setting rq->deadline | |
701 | * and clearing the flag in blk_mq_start_request(), so | |
702 | * this rq won't be timed out too. | |
703 | */ | |
46f92d42 CH |
704 | if (time_after_eq(jiffies, rq->deadline)) { |
705 | if (!blk_mark_rq_complete(rq)) | |
0152fb6b | 706 | blk_mq_rq_timed_out(rq, reserved); |
46f92d42 CH |
707 | } else if (!data->next_set || time_after(data->next, rq->deadline)) { |
708 | data->next = rq->deadline; | |
709 | data->next_set = 1; | |
710 | } | |
87ee7b11 JA |
711 | } |
712 | ||
287922eb | 713 | static void blk_mq_timeout_work(struct work_struct *work) |
320ae51f | 714 | { |
287922eb CH |
715 | struct request_queue *q = |
716 | container_of(work, struct request_queue, timeout_work); | |
81481eb4 CH |
717 | struct blk_mq_timeout_data data = { |
718 | .next = 0, | |
719 | .next_set = 0, | |
720 | }; | |
81481eb4 | 721 | int i; |
320ae51f | 722 | |
71f79fb3 GKB |
723 | /* A deadlock might occur if a request is stuck requiring a |
724 | * timeout at the same time a queue freeze is waiting | |
725 | * completion, since the timeout code would not be able to | |
726 | * acquire the queue reference here. | |
727 | * | |
728 | * That's why we don't use blk_queue_enter here; instead, we use | |
729 | * percpu_ref_tryget directly, because we need to be able to | |
730 | * obtain a reference even in the short window between the queue | |
731 | * starting to freeze, by dropping the first reference in | |
1671d522 | 732 | * blk_freeze_queue_start, and the moment the last request is |
71f79fb3 GKB |
733 | * consumed, marked by the instant q_usage_counter reaches |
734 | * zero. | |
735 | */ | |
736 | if (!percpu_ref_tryget(&q->q_usage_counter)) | |
287922eb CH |
737 | return; |
738 | ||
0bf6cd5b | 739 | blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &data); |
320ae51f | 740 | |
81481eb4 CH |
741 | if (data.next_set) { |
742 | data.next = blk_rq_timeout(round_jiffies_up(data.next)); | |
743 | mod_timer(&q->timeout, data.next); | |
0d2602ca | 744 | } else { |
0bf6cd5b CH |
745 | struct blk_mq_hw_ctx *hctx; |
746 | ||
f054b56c ML |
747 | queue_for_each_hw_ctx(q, hctx, i) { |
748 | /* the hctx may be unmapped, so check it here */ | |
749 | if (blk_mq_hw_queue_mapped(hctx)) | |
750 | blk_mq_tag_idle(hctx); | |
751 | } | |
0d2602ca | 752 | } |
287922eb | 753 | blk_queue_exit(q); |
320ae51f JA |
754 | } |
755 | ||
756 | /* | |
757 | * Reverse check our software queue for entries that we could potentially | |
758 | * merge with. Currently includes a hand-wavy stop count of 8, to not spend | |
759 | * too much time checking for merges. | |
760 | */ | |
761 | static bool blk_mq_attempt_merge(struct request_queue *q, | |
762 | struct blk_mq_ctx *ctx, struct bio *bio) | |
763 | { | |
764 | struct request *rq; | |
765 | int checked = 8; | |
766 | ||
767 | list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) { | |
34fe7c05 | 768 | bool merged = false; |
320ae51f JA |
769 | |
770 | if (!checked--) | |
771 | break; | |
772 | ||
773 | if (!blk_rq_merge_ok(rq, bio)) | |
774 | continue; | |
775 | ||
34fe7c05 CH |
776 | switch (blk_try_merge(rq, bio)) { |
777 | case ELEVATOR_BACK_MERGE: | |
778 | if (blk_mq_sched_allow_merge(q, rq, bio)) | |
779 | merged = bio_attempt_back_merge(q, rq, bio); | |
bd166ef1 | 780 | break; |
34fe7c05 CH |
781 | case ELEVATOR_FRONT_MERGE: |
782 | if (blk_mq_sched_allow_merge(q, rq, bio)) | |
783 | merged = bio_attempt_front_merge(q, rq, bio); | |
320ae51f | 784 | break; |
1e739730 CH |
785 | case ELEVATOR_DISCARD_MERGE: |
786 | merged = bio_attempt_discard_merge(q, rq, bio); | |
320ae51f | 787 | break; |
34fe7c05 CH |
788 | default: |
789 | continue; | |
320ae51f | 790 | } |
34fe7c05 CH |
791 | |
792 | if (merged) | |
793 | ctx->rq_merged++; | |
794 | return merged; | |
320ae51f JA |
795 | } |
796 | ||
797 | return false; | |
798 | } | |
799 | ||
88459642 OS |
800 | struct flush_busy_ctx_data { |
801 | struct blk_mq_hw_ctx *hctx; | |
802 | struct list_head *list; | |
803 | }; | |
804 | ||
805 | static bool flush_busy_ctx(struct sbitmap *sb, unsigned int bitnr, void *data) | |
806 | { | |
807 | struct flush_busy_ctx_data *flush_data = data; | |
808 | struct blk_mq_hw_ctx *hctx = flush_data->hctx; | |
809 | struct blk_mq_ctx *ctx = hctx->ctxs[bitnr]; | |
810 | ||
811 | sbitmap_clear_bit(sb, bitnr); | |
812 | spin_lock(&ctx->lock); | |
813 | list_splice_tail_init(&ctx->rq_list, flush_data->list); | |
814 | spin_unlock(&ctx->lock); | |
815 | return true; | |
816 | } | |
817 | ||
1429d7c9 JA |
818 | /* |
819 | * Process software queues that have been marked busy, splicing them | |
820 | * to the for-dispatch | |
821 | */ | |
2c3ad667 | 822 | void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) |
1429d7c9 | 823 | { |
88459642 OS |
824 | struct flush_busy_ctx_data data = { |
825 | .hctx = hctx, | |
826 | .list = list, | |
827 | }; | |
1429d7c9 | 828 | |
88459642 | 829 | sbitmap_for_each_set(&hctx->ctx_map, flush_busy_ctx, &data); |
1429d7c9 | 830 | } |
2c3ad667 | 831 | EXPORT_SYMBOL_GPL(blk_mq_flush_busy_ctxs); |
1429d7c9 | 832 | |
703fd1c0 JA |
833 | static inline unsigned int queued_to_index(unsigned int queued) |
834 | { | |
835 | if (!queued) | |
836 | return 0; | |
1429d7c9 | 837 | |
703fd1c0 | 838 | return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1); |
1429d7c9 JA |
839 | } |
840 | ||
bd6737f1 JA |
841 | bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx, |
842 | bool wait) | |
bd166ef1 JA |
843 | { |
844 | struct blk_mq_alloc_data data = { | |
845 | .q = rq->q, | |
bd166ef1 JA |
846 | .hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu), |
847 | .flags = wait ? 0 : BLK_MQ_REQ_NOWAIT, | |
848 | }; | |
849 | ||
81380ca1 OS |
850 | if (rq->tag != -1) |
851 | goto done; | |
bd166ef1 | 852 | |
415b806d SG |
853 | if (blk_mq_tag_is_reserved(data.hctx->sched_tags, rq->internal_tag)) |
854 | data.flags |= BLK_MQ_REQ_RESERVED; | |
855 | ||
bd166ef1 JA |
856 | rq->tag = blk_mq_get_tag(&data); |
857 | if (rq->tag >= 0) { | |
200e86b3 JA |
858 | if (blk_mq_tag_busy(data.hctx)) { |
859 | rq->rq_flags |= RQF_MQ_INFLIGHT; | |
860 | atomic_inc(&data.hctx->nr_active); | |
861 | } | |
bd166ef1 | 862 | data.hctx->tags->rqs[rq->tag] = rq; |
bd166ef1 JA |
863 | } |
864 | ||
81380ca1 OS |
865 | done: |
866 | if (hctx) | |
867 | *hctx = data.hctx; | |
868 | return rq->tag != -1; | |
bd166ef1 JA |
869 | } |
870 | ||
113285b4 JA |
871 | static void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx, |
872 | struct request *rq) | |
99cf1dc5 | 873 | { |
99cf1dc5 JA |
874 | blk_mq_put_tag(hctx, hctx->tags, rq->mq_ctx, rq->tag); |
875 | rq->tag = -1; | |
876 | ||
877 | if (rq->rq_flags & RQF_MQ_INFLIGHT) { | |
878 | rq->rq_flags &= ~RQF_MQ_INFLIGHT; | |
879 | atomic_dec(&hctx->nr_active); | |
880 | } | |
881 | } | |
882 | ||
113285b4 JA |
883 | static void blk_mq_put_driver_tag_hctx(struct blk_mq_hw_ctx *hctx, |
884 | struct request *rq) | |
885 | { | |
886 | if (rq->tag == -1 || rq->internal_tag == -1) | |
887 | return; | |
888 | ||
889 | __blk_mq_put_driver_tag(hctx, rq); | |
890 | } | |
891 | ||
892 | static void blk_mq_put_driver_tag(struct request *rq) | |
893 | { | |
894 | struct blk_mq_hw_ctx *hctx; | |
895 | ||
896 | if (rq->tag == -1 || rq->internal_tag == -1) | |
897 | return; | |
898 | ||
899 | hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu); | |
900 | __blk_mq_put_driver_tag(hctx, rq); | |
901 | } | |
902 | ||
bd166ef1 JA |
903 | /* |
904 | * If we fail getting a driver tag because all the driver tags are already | |
905 | * assigned and on the dispatch list, BUT the first entry does not have a | |
906 | * tag, then we could deadlock. For that case, move entries with assigned | |
907 | * driver tags to the front, leaving the set of tagged requests in the | |
908 | * same order, and the untagged set in the same order. | |
909 | */ | |
910 | static bool reorder_tags_to_front(struct list_head *list) | |
911 | { | |
912 | struct request *rq, *tmp, *first = NULL; | |
913 | ||
914 | list_for_each_entry_safe_reverse(rq, tmp, list, queuelist) { | |
915 | if (rq == first) | |
916 | break; | |
917 | if (rq->tag != -1) { | |
918 | list_move(&rq->queuelist, list); | |
919 | if (!first) | |
920 | first = rq; | |
921 | } | |
922 | } | |
923 | ||
924 | return first != NULL; | |
925 | } | |
926 | ||
da55f2cc OS |
927 | static int blk_mq_dispatch_wake(wait_queue_t *wait, unsigned mode, int flags, |
928 | void *key) | |
929 | { | |
930 | struct blk_mq_hw_ctx *hctx; | |
931 | ||
932 | hctx = container_of(wait, struct blk_mq_hw_ctx, dispatch_wait); | |
933 | ||
934 | list_del(&wait->task_list); | |
935 | clear_bit_unlock(BLK_MQ_S_TAG_WAITING, &hctx->state); | |
936 | blk_mq_run_hw_queue(hctx, true); | |
937 | return 1; | |
938 | } | |
939 | ||
940 | static bool blk_mq_dispatch_wait_add(struct blk_mq_hw_ctx *hctx) | |
941 | { | |
942 | struct sbq_wait_state *ws; | |
943 | ||
944 | /* | |
945 | * The TAG_WAITING bit serves as a lock protecting hctx->dispatch_wait. | |
946 | * The thread which wins the race to grab this bit adds the hardware | |
947 | * queue to the wait queue. | |
948 | */ | |
949 | if (test_bit(BLK_MQ_S_TAG_WAITING, &hctx->state) || | |
950 | test_and_set_bit_lock(BLK_MQ_S_TAG_WAITING, &hctx->state)) | |
951 | return false; | |
952 | ||
953 | init_waitqueue_func_entry(&hctx->dispatch_wait, blk_mq_dispatch_wake); | |
954 | ws = bt_wait_ptr(&hctx->tags->bitmap_tags, hctx); | |
955 | ||
956 | /* | |
957 | * As soon as this returns, it's no longer safe to fiddle with | |
958 | * hctx->dispatch_wait, since a completion can wake up the wait queue | |
959 | * and unlock the bit. | |
960 | */ | |
961 | add_wait_queue(&ws->wait, &hctx->dispatch_wait); | |
962 | return true; | |
963 | } | |
964 | ||
81380ca1 | 965 | bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list) |
320ae51f | 966 | { |
81380ca1 | 967 | struct blk_mq_hw_ctx *hctx; |
320ae51f | 968 | struct request *rq; |
3e8a7069 | 969 | int errors, queued, ret = BLK_MQ_RQ_QUEUE_OK; |
320ae51f | 970 | |
81380ca1 OS |
971 | if (list_empty(list)) |
972 | return false; | |
973 | ||
320ae51f JA |
974 | /* |
975 | * Now process all the entries, sending them to the driver. | |
976 | */ | |
3e8a7069 | 977 | errors = queued = 0; |
81380ca1 | 978 | do { |
74c45052 | 979 | struct blk_mq_queue_data bd; |
320ae51f | 980 | |
f04c3df3 | 981 | rq = list_first_entry(list, struct request, queuelist); |
bd166ef1 JA |
982 | if (!blk_mq_get_driver_tag(rq, &hctx, false)) { |
983 | if (!queued && reorder_tags_to_front(list)) | |
984 | continue; | |
3c782d67 JA |
985 | |
986 | /* | |
da55f2cc OS |
987 | * The initial allocation attempt failed, so we need to |
988 | * rerun the hardware queue when a tag is freed. | |
3c782d67 | 989 | */ |
807b1041 OS |
990 | if (!blk_mq_dispatch_wait_add(hctx)) |
991 | break; | |
992 | ||
993 | /* | |
994 | * It's possible that a tag was freed in the window | |
995 | * between the allocation failure and adding the | |
996 | * hardware queue to the wait queue. | |
997 | */ | |
998 | if (!blk_mq_get_driver_tag(rq, &hctx, false)) | |
3c782d67 | 999 | break; |
bd166ef1 | 1000 | } |
da55f2cc | 1001 | |
320ae51f | 1002 | list_del_init(&rq->queuelist); |
320ae51f | 1003 | |
74c45052 | 1004 | bd.rq = rq; |
113285b4 JA |
1005 | |
1006 | /* | |
1007 | * Flag last if we have no more requests, or if we have more | |
1008 | * but can't assign a driver tag to it. | |
1009 | */ | |
1010 | if (list_empty(list)) | |
1011 | bd.last = true; | |
1012 | else { | |
1013 | struct request *nxt; | |
1014 | ||
1015 | nxt = list_first_entry(list, struct request, queuelist); | |
1016 | bd.last = !blk_mq_get_driver_tag(nxt, NULL, false); | |
1017 | } | |
74c45052 JA |
1018 | |
1019 | ret = q->mq_ops->queue_rq(hctx, &bd); | |
320ae51f JA |
1020 | switch (ret) { |
1021 | case BLK_MQ_RQ_QUEUE_OK: | |
1022 | queued++; | |
52b9c330 | 1023 | break; |
320ae51f | 1024 | case BLK_MQ_RQ_QUEUE_BUSY: |
113285b4 | 1025 | blk_mq_put_driver_tag_hctx(hctx, rq); |
f04c3df3 | 1026 | list_add(&rq->queuelist, list); |
ed0791b2 | 1027 | __blk_mq_requeue_request(rq); |
320ae51f JA |
1028 | break; |
1029 | default: | |
1030 | pr_err("blk-mq: bad return on queue: %d\n", ret); | |
320ae51f | 1031 | case BLK_MQ_RQ_QUEUE_ERROR: |
3e8a7069 | 1032 | errors++; |
caf7df12 | 1033 | blk_mq_end_request(rq, -EIO); |
320ae51f JA |
1034 | break; |
1035 | } | |
1036 | ||
1037 | if (ret == BLK_MQ_RQ_QUEUE_BUSY) | |
1038 | break; | |
81380ca1 | 1039 | } while (!list_empty(list)); |
320ae51f | 1040 | |
703fd1c0 | 1041 | hctx->dispatched[queued_to_index(queued)]++; |
320ae51f JA |
1042 | |
1043 | /* | |
1044 | * Any items that need requeuing? Stuff them into hctx->dispatch, | |
1045 | * that is where we will continue on next queue run. | |
1046 | */ | |
f04c3df3 | 1047 | if (!list_empty(list)) { |
113285b4 | 1048 | /* |
710c785f BVA |
1049 | * If an I/O scheduler has been configured and we got a driver |
1050 | * tag for the next request already, free it again. | |
113285b4 JA |
1051 | */ |
1052 | rq = list_first_entry(list, struct request, queuelist); | |
1053 | blk_mq_put_driver_tag(rq); | |
1054 | ||
320ae51f | 1055 | spin_lock(&hctx->lock); |
c13660a0 | 1056 | list_splice_init(list, &hctx->dispatch); |
320ae51f | 1057 | spin_unlock(&hctx->lock); |
f04c3df3 | 1058 | |
9ba52e58 | 1059 | /* |
710c785f BVA |
1060 | * If SCHED_RESTART was set by the caller of this function and |
1061 | * it is no longer set that means that it was cleared by another | |
1062 | * thread and hence that a queue rerun is needed. | |
9ba52e58 | 1063 | * |
710c785f BVA |
1064 | * If TAG_WAITING is set that means that an I/O scheduler has |
1065 | * been configured and another thread is waiting for a driver | |
1066 | * tag. To guarantee fairness, do not rerun this hardware queue | |
1067 | * but let the other thread grab the driver tag. | |
bd166ef1 | 1068 | * |
710c785f BVA |
1069 | * If no I/O scheduler has been configured it is possible that |
1070 | * the hardware queue got stopped and restarted before requests | |
1071 | * were pushed back onto the dispatch list. Rerun the queue to | |
1072 | * avoid starvation. Notes: | |
1073 | * - blk_mq_run_hw_queue() checks whether or not a queue has | |
1074 | * been stopped before rerunning a queue. | |
1075 | * - Some but not all block drivers stop a queue before | |
1076 | * returning BLK_MQ_RQ_QUEUE_BUSY. Two exceptions are scsi-mq | |
1077 | * and dm-rq. | |
bd166ef1 | 1078 | */ |
da55f2cc OS |
1079 | if (!blk_mq_sched_needs_restart(hctx) && |
1080 | !test_bit(BLK_MQ_S_TAG_WAITING, &hctx->state)) | |
bd166ef1 | 1081 | blk_mq_run_hw_queue(hctx, true); |
320ae51f | 1082 | } |
f04c3df3 | 1083 | |
3e8a7069 | 1084 | return (queued + errors) != 0; |
f04c3df3 JA |
1085 | } |
1086 | ||
6a83e74d BVA |
1087 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) |
1088 | { | |
1089 | int srcu_idx; | |
1090 | ||
1091 | WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) && | |
1092 | cpu_online(hctx->next_cpu)); | |
1093 | ||
1094 | if (!(hctx->flags & BLK_MQ_F_BLOCKING)) { | |
1095 | rcu_read_lock(); | |
bd166ef1 | 1096 | blk_mq_sched_dispatch_requests(hctx); |
6a83e74d BVA |
1097 | rcu_read_unlock(); |
1098 | } else { | |
bf4907c0 JA |
1099 | might_sleep(); |
1100 | ||
6a83e74d | 1101 | srcu_idx = srcu_read_lock(&hctx->queue_rq_srcu); |
bd166ef1 | 1102 | blk_mq_sched_dispatch_requests(hctx); |
6a83e74d BVA |
1103 | srcu_read_unlock(&hctx->queue_rq_srcu, srcu_idx); |
1104 | } | |
1105 | } | |
1106 | ||
506e931f JA |
1107 | /* |
1108 | * It'd be great if the workqueue API had a way to pass | |
1109 | * in a mask and had some smarts for more clever placement. | |
1110 | * For now we just round-robin here, switching for every | |
1111 | * BLK_MQ_CPU_WORK_BATCH queued items. | |
1112 | */ | |
1113 | static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) | |
1114 | { | |
b657d7e6 CH |
1115 | if (hctx->queue->nr_hw_queues == 1) |
1116 | return WORK_CPU_UNBOUND; | |
506e931f JA |
1117 | |
1118 | if (--hctx->next_cpu_batch <= 0) { | |
c02ebfdd | 1119 | int next_cpu; |
506e931f JA |
1120 | |
1121 | next_cpu = cpumask_next(hctx->next_cpu, hctx->cpumask); | |
1122 | if (next_cpu >= nr_cpu_ids) | |
1123 | next_cpu = cpumask_first(hctx->cpumask); | |
1124 | ||
1125 | hctx->next_cpu = next_cpu; | |
1126 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
1127 | } | |
1128 | ||
b657d7e6 | 1129 | return hctx->next_cpu; |
506e931f JA |
1130 | } |
1131 | ||
7587a5ae BVA |
1132 | static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async, |
1133 | unsigned long msecs) | |
320ae51f | 1134 | { |
5d1b25c1 BVA |
1135 | if (unlikely(blk_mq_hctx_stopped(hctx) || |
1136 | !blk_mq_hw_queue_mapped(hctx))) | |
320ae51f JA |
1137 | return; |
1138 | ||
1b792f2f | 1139 | if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) { |
2a90d4aa PB |
1140 | int cpu = get_cpu(); |
1141 | if (cpumask_test_cpu(cpu, hctx->cpumask)) { | |
398205b8 | 1142 | __blk_mq_run_hw_queue(hctx); |
2a90d4aa | 1143 | put_cpu(); |
398205b8 PB |
1144 | return; |
1145 | } | |
e4043dcf | 1146 | |
2a90d4aa | 1147 | put_cpu(); |
e4043dcf | 1148 | } |
398205b8 | 1149 | |
7587a5ae BVA |
1150 | if (msecs == 0) |
1151 | kblockd_schedule_work_on(blk_mq_hctx_next_cpu(hctx), | |
1152 | &hctx->run_work); | |
1153 | else | |
1154 | kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx), | |
1155 | &hctx->delayed_run_work, | |
1156 | msecs_to_jiffies(msecs)); | |
1157 | } | |
1158 | ||
1159 | void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) | |
1160 | { | |
1161 | __blk_mq_delay_run_hw_queue(hctx, true, msecs); | |
1162 | } | |
1163 | EXPORT_SYMBOL(blk_mq_delay_run_hw_queue); | |
1164 | ||
1165 | void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) | |
1166 | { | |
1167 | __blk_mq_delay_run_hw_queue(hctx, async, 0); | |
320ae51f | 1168 | } |
5b727272 | 1169 | EXPORT_SYMBOL(blk_mq_run_hw_queue); |
320ae51f | 1170 | |
b94ec296 | 1171 | void blk_mq_run_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
1172 | { |
1173 | struct blk_mq_hw_ctx *hctx; | |
1174 | int i; | |
1175 | ||
1176 | queue_for_each_hw_ctx(q, hctx, i) { | |
bd166ef1 | 1177 | if (!blk_mq_hctx_has_pending(hctx) || |
5d1b25c1 | 1178 | blk_mq_hctx_stopped(hctx)) |
320ae51f JA |
1179 | continue; |
1180 | ||
b94ec296 | 1181 | blk_mq_run_hw_queue(hctx, async); |
320ae51f JA |
1182 | } |
1183 | } | |
b94ec296 | 1184 | EXPORT_SYMBOL(blk_mq_run_hw_queues); |
320ae51f | 1185 | |
fd001443 BVA |
1186 | /** |
1187 | * blk_mq_queue_stopped() - check whether one or more hctxs have been stopped | |
1188 | * @q: request queue. | |
1189 | * | |
1190 | * The caller is responsible for serializing this function against | |
1191 | * blk_mq_{start,stop}_hw_queue(). | |
1192 | */ | |
1193 | bool blk_mq_queue_stopped(struct request_queue *q) | |
1194 | { | |
1195 | struct blk_mq_hw_ctx *hctx; | |
1196 | int i; | |
1197 | ||
1198 | queue_for_each_hw_ctx(q, hctx, i) | |
1199 | if (blk_mq_hctx_stopped(hctx)) | |
1200 | return true; | |
1201 | ||
1202 | return false; | |
1203 | } | |
1204 | EXPORT_SYMBOL(blk_mq_queue_stopped); | |
1205 | ||
320ae51f JA |
1206 | void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx) |
1207 | { | |
27489a3c | 1208 | cancel_work(&hctx->run_work); |
70f4db63 | 1209 | cancel_delayed_work(&hctx->delay_work); |
320ae51f JA |
1210 | set_bit(BLK_MQ_S_STOPPED, &hctx->state); |
1211 | } | |
1212 | EXPORT_SYMBOL(blk_mq_stop_hw_queue); | |
1213 | ||
280d45f6 CH |
1214 | void blk_mq_stop_hw_queues(struct request_queue *q) |
1215 | { | |
1216 | struct blk_mq_hw_ctx *hctx; | |
1217 | int i; | |
1218 | ||
1219 | queue_for_each_hw_ctx(q, hctx, i) | |
1220 | blk_mq_stop_hw_queue(hctx); | |
1221 | } | |
1222 | EXPORT_SYMBOL(blk_mq_stop_hw_queues); | |
1223 | ||
320ae51f JA |
1224 | void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx) |
1225 | { | |
1226 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
e4043dcf | 1227 | |
0ffbce80 | 1228 | blk_mq_run_hw_queue(hctx, false); |
320ae51f JA |
1229 | } |
1230 | EXPORT_SYMBOL(blk_mq_start_hw_queue); | |
1231 | ||
2f268556 CH |
1232 | void blk_mq_start_hw_queues(struct request_queue *q) |
1233 | { | |
1234 | struct blk_mq_hw_ctx *hctx; | |
1235 | int i; | |
1236 | ||
1237 | queue_for_each_hw_ctx(q, hctx, i) | |
1238 | blk_mq_start_hw_queue(hctx); | |
1239 | } | |
1240 | EXPORT_SYMBOL(blk_mq_start_hw_queues); | |
1241 | ||
ae911c5e JA |
1242 | void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
1243 | { | |
1244 | if (!blk_mq_hctx_stopped(hctx)) | |
1245 | return; | |
1246 | ||
1247 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
1248 | blk_mq_run_hw_queue(hctx, async); | |
1249 | } | |
1250 | EXPORT_SYMBOL_GPL(blk_mq_start_stopped_hw_queue); | |
1251 | ||
1b4a3258 | 1252 | void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
1253 | { |
1254 | struct blk_mq_hw_ctx *hctx; | |
1255 | int i; | |
1256 | ||
ae911c5e JA |
1257 | queue_for_each_hw_ctx(q, hctx, i) |
1258 | blk_mq_start_stopped_hw_queue(hctx, async); | |
320ae51f JA |
1259 | } |
1260 | EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); | |
1261 | ||
70f4db63 | 1262 | static void blk_mq_run_work_fn(struct work_struct *work) |
320ae51f JA |
1263 | { |
1264 | struct blk_mq_hw_ctx *hctx; | |
1265 | ||
27489a3c | 1266 | hctx = container_of(work, struct blk_mq_hw_ctx, run_work); |
e4043dcf | 1267 | |
320ae51f JA |
1268 | __blk_mq_run_hw_queue(hctx); |
1269 | } | |
1270 | ||
7587a5ae BVA |
1271 | static void blk_mq_delayed_run_work_fn(struct work_struct *work) |
1272 | { | |
1273 | struct blk_mq_hw_ctx *hctx; | |
1274 | ||
1275 | hctx = container_of(work, struct blk_mq_hw_ctx, delayed_run_work.work); | |
1276 | ||
1277 | __blk_mq_run_hw_queue(hctx); | |
1278 | } | |
1279 | ||
70f4db63 CH |
1280 | static void blk_mq_delay_work_fn(struct work_struct *work) |
1281 | { | |
1282 | struct blk_mq_hw_ctx *hctx; | |
1283 | ||
1284 | hctx = container_of(work, struct blk_mq_hw_ctx, delay_work.work); | |
1285 | ||
1286 | if (test_and_clear_bit(BLK_MQ_S_STOPPED, &hctx->state)) | |
1287 | __blk_mq_run_hw_queue(hctx); | |
1288 | } | |
1289 | ||
1290 | void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) | |
1291 | { | |
19c66e59 ML |
1292 | if (unlikely(!blk_mq_hw_queue_mapped(hctx))) |
1293 | return; | |
70f4db63 | 1294 | |
7e79dadc | 1295 | blk_mq_stop_hw_queue(hctx); |
b657d7e6 CH |
1296 | kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx), |
1297 | &hctx->delay_work, msecs_to_jiffies(msecs)); | |
70f4db63 CH |
1298 | } |
1299 | EXPORT_SYMBOL(blk_mq_delay_queue); | |
1300 | ||
cfd0c552 | 1301 | static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx, |
cfd0c552 ML |
1302 | struct request *rq, |
1303 | bool at_head) | |
320ae51f | 1304 | { |
e57690fe JA |
1305 | struct blk_mq_ctx *ctx = rq->mq_ctx; |
1306 | ||
01b983c9 JA |
1307 | trace_block_rq_insert(hctx->queue, rq); |
1308 | ||
72a0a36e CH |
1309 | if (at_head) |
1310 | list_add(&rq->queuelist, &ctx->rq_list); | |
1311 | else | |
1312 | list_add_tail(&rq->queuelist, &ctx->rq_list); | |
cfd0c552 | 1313 | } |
4bb659b1 | 1314 | |
2c3ad667 JA |
1315 | void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, |
1316 | bool at_head) | |
cfd0c552 ML |
1317 | { |
1318 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
1319 | ||
e57690fe | 1320 | __blk_mq_insert_req_list(hctx, rq, at_head); |
320ae51f | 1321 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f JA |
1322 | } |
1323 | ||
bd166ef1 JA |
1324 | void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, |
1325 | struct list_head *list) | |
320ae51f JA |
1326 | |
1327 | { | |
320ae51f JA |
1328 | /* |
1329 | * preemption doesn't flush plug list, so it's possible ctx->cpu is | |
1330 | * offline now | |
1331 | */ | |
1332 | spin_lock(&ctx->lock); | |
1333 | while (!list_empty(list)) { | |
1334 | struct request *rq; | |
1335 | ||
1336 | rq = list_first_entry(list, struct request, queuelist); | |
e57690fe | 1337 | BUG_ON(rq->mq_ctx != ctx); |
320ae51f | 1338 | list_del_init(&rq->queuelist); |
e57690fe | 1339 | __blk_mq_insert_req_list(hctx, rq, false); |
320ae51f | 1340 | } |
cfd0c552 | 1341 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f | 1342 | spin_unlock(&ctx->lock); |
320ae51f JA |
1343 | } |
1344 | ||
1345 | static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b) | |
1346 | { | |
1347 | struct request *rqa = container_of(a, struct request, queuelist); | |
1348 | struct request *rqb = container_of(b, struct request, queuelist); | |
1349 | ||
1350 | return !(rqa->mq_ctx < rqb->mq_ctx || | |
1351 | (rqa->mq_ctx == rqb->mq_ctx && | |
1352 | blk_rq_pos(rqa) < blk_rq_pos(rqb))); | |
1353 | } | |
1354 | ||
1355 | void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) | |
1356 | { | |
1357 | struct blk_mq_ctx *this_ctx; | |
1358 | struct request_queue *this_q; | |
1359 | struct request *rq; | |
1360 | LIST_HEAD(list); | |
1361 | LIST_HEAD(ctx_list); | |
1362 | unsigned int depth; | |
1363 | ||
1364 | list_splice_init(&plug->mq_list, &list); | |
1365 | ||
1366 | list_sort(NULL, &list, plug_ctx_cmp); | |
1367 | ||
1368 | this_q = NULL; | |
1369 | this_ctx = NULL; | |
1370 | depth = 0; | |
1371 | ||
1372 | while (!list_empty(&list)) { | |
1373 | rq = list_entry_rq(list.next); | |
1374 | list_del_init(&rq->queuelist); | |
1375 | BUG_ON(!rq->q); | |
1376 | if (rq->mq_ctx != this_ctx) { | |
1377 | if (this_ctx) { | |
bd166ef1 JA |
1378 | trace_block_unplug(this_q, depth, from_schedule); |
1379 | blk_mq_sched_insert_requests(this_q, this_ctx, | |
1380 | &ctx_list, | |
1381 | from_schedule); | |
320ae51f JA |
1382 | } |
1383 | ||
1384 | this_ctx = rq->mq_ctx; | |
1385 | this_q = rq->q; | |
1386 | depth = 0; | |
1387 | } | |
1388 | ||
1389 | depth++; | |
1390 | list_add_tail(&rq->queuelist, &ctx_list); | |
1391 | } | |
1392 | ||
1393 | /* | |
1394 | * If 'this_ctx' is set, we know we have entries to complete | |
1395 | * on 'ctx_list'. Do those. | |
1396 | */ | |
1397 | if (this_ctx) { | |
bd166ef1 JA |
1398 | trace_block_unplug(this_q, depth, from_schedule); |
1399 | blk_mq_sched_insert_requests(this_q, this_ctx, &ctx_list, | |
1400 | from_schedule); | |
320ae51f JA |
1401 | } |
1402 | } | |
1403 | ||
1404 | static void blk_mq_bio_to_request(struct request *rq, struct bio *bio) | |
1405 | { | |
da8d7f07 | 1406 | blk_init_request_from_bio(rq, bio); |
4b570521 | 1407 | |
6e85eaf3 | 1408 | blk_account_io_start(rq, true); |
320ae51f JA |
1409 | } |
1410 | ||
274a5843 JA |
1411 | static inline bool hctx_allow_merges(struct blk_mq_hw_ctx *hctx) |
1412 | { | |
1413 | return (hctx->flags & BLK_MQ_F_SHOULD_MERGE) && | |
1414 | !blk_queue_nomerges(hctx->queue); | |
1415 | } | |
1416 | ||
07068d5b JA |
1417 | static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx, |
1418 | struct blk_mq_ctx *ctx, | |
1419 | struct request *rq, struct bio *bio) | |
320ae51f | 1420 | { |
e18378a6 | 1421 | if (!hctx_allow_merges(hctx) || !bio_mergeable(bio)) { |
07068d5b JA |
1422 | blk_mq_bio_to_request(rq, bio); |
1423 | spin_lock(&ctx->lock); | |
1424 | insert_rq: | |
1425 | __blk_mq_insert_request(hctx, rq, false); | |
1426 | spin_unlock(&ctx->lock); | |
1427 | return false; | |
1428 | } else { | |
274a5843 JA |
1429 | struct request_queue *q = hctx->queue; |
1430 | ||
07068d5b JA |
1431 | spin_lock(&ctx->lock); |
1432 | if (!blk_mq_attempt_merge(q, ctx, bio)) { | |
1433 | blk_mq_bio_to_request(rq, bio); | |
1434 | goto insert_rq; | |
1435 | } | |
320ae51f | 1436 | |
07068d5b | 1437 | spin_unlock(&ctx->lock); |
bd166ef1 | 1438 | __blk_mq_finish_request(hctx, ctx, rq); |
07068d5b | 1439 | return true; |
14ec77f3 | 1440 | } |
07068d5b | 1441 | } |
14ec77f3 | 1442 | |
fd2d3326 JA |
1443 | static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq) |
1444 | { | |
bd166ef1 JA |
1445 | if (rq->tag != -1) |
1446 | return blk_tag_to_qc_t(rq->tag, hctx->queue_num, false); | |
1447 | ||
1448 | return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true); | |
fd2d3326 JA |
1449 | } |
1450 | ||
5eb6126e | 1451 | static void __blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie, |
9c621104 | 1452 | bool may_sleep) |
f984df1f | 1453 | { |
f984df1f | 1454 | struct request_queue *q = rq->q; |
f984df1f SL |
1455 | struct blk_mq_queue_data bd = { |
1456 | .rq = rq, | |
d945a365 | 1457 | .last = true, |
f984df1f | 1458 | }; |
bd166ef1 JA |
1459 | struct blk_mq_hw_ctx *hctx; |
1460 | blk_qc_t new_cookie; | |
1461 | int ret; | |
f984df1f | 1462 | |
bd166ef1 | 1463 | if (q->elevator) |
2253efc8 BVA |
1464 | goto insert; |
1465 | ||
bd166ef1 JA |
1466 | if (!blk_mq_get_driver_tag(rq, &hctx, false)) |
1467 | goto insert; | |
1468 | ||
1469 | new_cookie = request_to_qc_t(hctx, rq); | |
1470 | ||
f984df1f SL |
1471 | /* |
1472 | * For OK queue, we are done. For error, kill it. Any other | |
1473 | * error (busy), just add it to our list as we previously | |
1474 | * would have done | |
1475 | */ | |
1476 | ret = q->mq_ops->queue_rq(hctx, &bd); | |
7b371636 JA |
1477 | if (ret == BLK_MQ_RQ_QUEUE_OK) { |
1478 | *cookie = new_cookie; | |
2253efc8 | 1479 | return; |
7b371636 | 1480 | } |
f984df1f | 1481 | |
7b371636 JA |
1482 | if (ret == BLK_MQ_RQ_QUEUE_ERROR) { |
1483 | *cookie = BLK_QC_T_NONE; | |
caf7df12 | 1484 | blk_mq_end_request(rq, -EIO); |
2253efc8 | 1485 | return; |
f984df1f | 1486 | } |
7b371636 | 1487 | |
b58e1769 | 1488 | __blk_mq_requeue_request(rq); |
2253efc8 | 1489 | insert: |
9c621104 | 1490 | blk_mq_sched_insert_request(rq, false, true, false, may_sleep); |
f984df1f SL |
1491 | } |
1492 | ||
5eb6126e CH |
1493 | static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, |
1494 | struct request *rq, blk_qc_t *cookie) | |
1495 | { | |
1496 | if (!(hctx->flags & BLK_MQ_F_BLOCKING)) { | |
1497 | rcu_read_lock(); | |
1498 | __blk_mq_try_issue_directly(rq, cookie, false); | |
1499 | rcu_read_unlock(); | |
1500 | } else { | |
bf4907c0 JA |
1501 | unsigned int srcu_idx; |
1502 | ||
1503 | might_sleep(); | |
1504 | ||
1505 | srcu_idx = srcu_read_lock(&hctx->queue_rq_srcu); | |
5eb6126e CH |
1506 | __blk_mq_try_issue_directly(rq, cookie, true); |
1507 | srcu_read_unlock(&hctx->queue_rq_srcu, srcu_idx); | |
1508 | } | |
1509 | } | |
1510 | ||
dece1635 | 1511 | static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) |
07068d5b | 1512 | { |
ef295ecf | 1513 | const int is_sync = op_is_sync(bio->bi_opf); |
f73f44eb | 1514 | const int is_flush_fua = op_is_flush(bio->bi_opf); |
5a797e00 | 1515 | struct blk_mq_alloc_data data = { .flags = 0 }; |
07068d5b | 1516 | struct request *rq; |
5eb6126e | 1517 | unsigned int request_count = 0; |
f984df1f | 1518 | struct blk_plug *plug; |
5b3f341f | 1519 | struct request *same_queue_rq = NULL; |
7b371636 | 1520 | blk_qc_t cookie; |
87760e5e | 1521 | unsigned int wb_acct; |
07068d5b JA |
1522 | |
1523 | blk_queue_bounce(q, &bio); | |
1524 | ||
1525 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
4246a0b6 | 1526 | bio_io_error(bio); |
dece1635 | 1527 | return BLK_QC_T_NONE; |
07068d5b JA |
1528 | } |
1529 | ||
54efd50b KO |
1530 | blk_queue_split(q, &bio, q->bio_split); |
1531 | ||
87c279e6 OS |
1532 | if (!is_flush_fua && !blk_queue_nomerges(q) && |
1533 | blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq)) | |
1534 | return BLK_QC_T_NONE; | |
f984df1f | 1535 | |
bd166ef1 JA |
1536 | if (blk_mq_sched_bio_merge(q, bio)) |
1537 | return BLK_QC_T_NONE; | |
1538 | ||
87760e5e JA |
1539 | wb_acct = wbt_wait(q->rq_wb, bio, NULL); |
1540 | ||
bd166ef1 JA |
1541 | trace_block_getrq(q, bio, bio->bi_opf); |
1542 | ||
1543 | rq = blk_mq_sched_get_request(q, bio, bio->bi_opf, &data); | |
87760e5e JA |
1544 | if (unlikely(!rq)) { |
1545 | __wbt_done(q->rq_wb, wb_acct); | |
dece1635 | 1546 | return BLK_QC_T_NONE; |
87760e5e JA |
1547 | } |
1548 | ||
1549 | wbt_track(&rq->issue_stat, wb_acct); | |
07068d5b | 1550 | |
fd2d3326 | 1551 | cookie = request_to_qc_t(data.hctx, rq); |
07068d5b | 1552 | |
a4d907b6 | 1553 | plug = current->plug; |
07068d5b JA |
1554 | if (unlikely(is_flush_fua)) { |
1555 | blk_mq_bio_to_request(rq, bio); | |
a4d907b6 CH |
1556 | if (q->elevator) { |
1557 | blk_mq_sched_insert_request(rq, false, true, true, | |
1558 | true); | |
1559 | } else { | |
1560 | blk_insert_flush(rq); | |
1561 | blk_mq_run_hw_queue(data.hctx, true); | |
1562 | } | |
1563 | } else if (plug && q->nr_hw_queues == 1) { | |
254d259d CH |
1564 | struct request *last = NULL; |
1565 | ||
1566 | blk_mq_bio_to_request(rq, bio); | |
1567 | ||
1568 | /* | |
1569 | * @request_count may become stale because of schedule | |
1570 | * out, so check the list again. | |
1571 | */ | |
1572 | if (list_empty(&plug->mq_list)) | |
1573 | request_count = 0; | |
1574 | else if (blk_queue_nomerges(q)) | |
1575 | request_count = blk_plug_queued_count(q); | |
1576 | ||
1577 | if (!request_count) | |
1578 | trace_block_plug(q); | |
1579 | else | |
1580 | last = list_entry_rq(plug->mq_list.prev); | |
1581 | ||
254d259d CH |
1582 | if (request_count >= BLK_MAX_REQUEST_COUNT || (last && |
1583 | blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE)) { | |
1584 | blk_flush_plug_list(plug, false); | |
1585 | trace_block_plug(q); | |
1586 | } | |
1587 | ||
1588 | list_add_tail(&rq->queuelist, &plug->mq_list); | |
2299722c | 1589 | } else if (plug && !blk_queue_nomerges(q)) { |
07068d5b | 1590 | blk_mq_bio_to_request(rq, bio); |
07068d5b JA |
1591 | |
1592 | /* | |
6a83e74d | 1593 | * We do limited plugging. If the bio can be merged, do that. |
f984df1f SL |
1594 | * Otherwise the existing request in the plug list will be |
1595 | * issued. So the plug list will have one request at most | |
2299722c CH |
1596 | * The plug list might get flushed before this. If that happens, |
1597 | * the plug list is empty, and same_queue_rq is invalid. | |
07068d5b | 1598 | */ |
2299722c CH |
1599 | if (list_empty(&plug->mq_list)) |
1600 | same_queue_rq = NULL; | |
1601 | if (same_queue_rq) | |
1602 | list_del_init(&same_queue_rq->queuelist); | |
1603 | list_add_tail(&rq->queuelist, &plug->mq_list); | |
1604 | ||
bf4907c0 JA |
1605 | blk_mq_put_ctx(data.ctx); |
1606 | ||
2299722c CH |
1607 | if (same_queue_rq) |
1608 | blk_mq_try_issue_directly(data.hctx, same_queue_rq, | |
1609 | &cookie); | |
bf4907c0 JA |
1610 | |
1611 | return cookie; | |
a4d907b6 | 1612 | } else if (q->nr_hw_queues > 1 && is_sync) { |
bf4907c0 | 1613 | blk_mq_put_ctx(data.ctx); |
2299722c | 1614 | blk_mq_bio_to_request(rq, bio); |
2299722c | 1615 | blk_mq_try_issue_directly(data.hctx, rq, &cookie); |
bf4907c0 | 1616 | return cookie; |
a4d907b6 | 1617 | } else if (q->elevator) { |
bd166ef1 | 1618 | blk_mq_bio_to_request(rq, bio); |
a4d907b6 | 1619 | blk_mq_sched_insert_request(rq, false, true, true, true); |
bf4907c0 | 1620 | } else if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) |
a4d907b6 | 1621 | blk_mq_run_hw_queue(data.hctx, true); |
a4d907b6 | 1622 | |
07068d5b | 1623 | blk_mq_put_ctx(data.ctx); |
7b371636 | 1624 | return cookie; |
07068d5b JA |
1625 | } |
1626 | ||
cc71a6f4 JA |
1627 | void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, |
1628 | unsigned int hctx_idx) | |
95363efd | 1629 | { |
e9b267d9 | 1630 | struct page *page; |
320ae51f | 1631 | |
24d2f903 | 1632 | if (tags->rqs && set->ops->exit_request) { |
e9b267d9 | 1633 | int i; |
320ae51f | 1634 | |
24d2f903 | 1635 | for (i = 0; i < tags->nr_tags; i++) { |
2af8cbe3 JA |
1636 | struct request *rq = tags->static_rqs[i]; |
1637 | ||
1638 | if (!rq) | |
e9b267d9 | 1639 | continue; |
2af8cbe3 | 1640 | set->ops->exit_request(set->driver_data, rq, |
24d2f903 | 1641 | hctx_idx, i); |
2af8cbe3 | 1642 | tags->static_rqs[i] = NULL; |
e9b267d9 | 1643 | } |
320ae51f | 1644 | } |
320ae51f | 1645 | |
24d2f903 CH |
1646 | while (!list_empty(&tags->page_list)) { |
1647 | page = list_first_entry(&tags->page_list, struct page, lru); | |
6753471c | 1648 | list_del_init(&page->lru); |
f75782e4 CM |
1649 | /* |
1650 | * Remove kmemleak object previously allocated in | |
1651 | * blk_mq_init_rq_map(). | |
1652 | */ | |
1653 | kmemleak_free(page_address(page)); | |
320ae51f JA |
1654 | __free_pages(page, page->private); |
1655 | } | |
cc71a6f4 | 1656 | } |
320ae51f | 1657 | |
cc71a6f4 JA |
1658 | void blk_mq_free_rq_map(struct blk_mq_tags *tags) |
1659 | { | |
24d2f903 | 1660 | kfree(tags->rqs); |
cc71a6f4 | 1661 | tags->rqs = NULL; |
2af8cbe3 JA |
1662 | kfree(tags->static_rqs); |
1663 | tags->static_rqs = NULL; | |
320ae51f | 1664 | |
24d2f903 | 1665 | blk_mq_free_tags(tags); |
320ae51f JA |
1666 | } |
1667 | ||
cc71a6f4 JA |
1668 | struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, |
1669 | unsigned int hctx_idx, | |
1670 | unsigned int nr_tags, | |
1671 | unsigned int reserved_tags) | |
320ae51f | 1672 | { |
24d2f903 | 1673 | struct blk_mq_tags *tags; |
59f082e4 | 1674 | int node; |
320ae51f | 1675 | |
59f082e4 SL |
1676 | node = blk_mq_hw_queue_to_node(set->mq_map, hctx_idx); |
1677 | if (node == NUMA_NO_NODE) | |
1678 | node = set->numa_node; | |
1679 | ||
1680 | tags = blk_mq_init_tags(nr_tags, reserved_tags, node, | |
24391c0d | 1681 | BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags)); |
24d2f903 CH |
1682 | if (!tags) |
1683 | return NULL; | |
320ae51f | 1684 | |
cc71a6f4 | 1685 | tags->rqs = kzalloc_node(nr_tags * sizeof(struct request *), |
36e1f3d1 | 1686 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, |
59f082e4 | 1687 | node); |
24d2f903 CH |
1688 | if (!tags->rqs) { |
1689 | blk_mq_free_tags(tags); | |
1690 | return NULL; | |
1691 | } | |
320ae51f | 1692 | |
2af8cbe3 JA |
1693 | tags->static_rqs = kzalloc_node(nr_tags * sizeof(struct request *), |
1694 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, | |
59f082e4 | 1695 | node); |
2af8cbe3 JA |
1696 | if (!tags->static_rqs) { |
1697 | kfree(tags->rqs); | |
1698 | blk_mq_free_tags(tags); | |
1699 | return NULL; | |
1700 | } | |
1701 | ||
cc71a6f4 JA |
1702 | return tags; |
1703 | } | |
1704 | ||
1705 | static size_t order_to_size(unsigned int order) | |
1706 | { | |
1707 | return (size_t)PAGE_SIZE << order; | |
1708 | } | |
1709 | ||
1710 | int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, | |
1711 | unsigned int hctx_idx, unsigned int depth) | |
1712 | { | |
1713 | unsigned int i, j, entries_per_page, max_order = 4; | |
1714 | size_t rq_size, left; | |
59f082e4 SL |
1715 | int node; |
1716 | ||
1717 | node = blk_mq_hw_queue_to_node(set->mq_map, hctx_idx); | |
1718 | if (node == NUMA_NO_NODE) | |
1719 | node = set->numa_node; | |
cc71a6f4 JA |
1720 | |
1721 | INIT_LIST_HEAD(&tags->page_list); | |
1722 | ||
320ae51f JA |
1723 | /* |
1724 | * rq_size is the size of the request plus driver payload, rounded | |
1725 | * to the cacheline size | |
1726 | */ | |
24d2f903 | 1727 | rq_size = round_up(sizeof(struct request) + set->cmd_size, |
320ae51f | 1728 | cache_line_size()); |
cc71a6f4 | 1729 | left = rq_size * depth; |
320ae51f | 1730 | |
cc71a6f4 | 1731 | for (i = 0; i < depth; ) { |
320ae51f JA |
1732 | int this_order = max_order; |
1733 | struct page *page; | |
1734 | int to_do; | |
1735 | void *p; | |
1736 | ||
b3a834b1 | 1737 | while (this_order && left < order_to_size(this_order - 1)) |
320ae51f JA |
1738 | this_order--; |
1739 | ||
1740 | do { | |
59f082e4 | 1741 | page = alloc_pages_node(node, |
36e1f3d1 | 1742 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO, |
a5164405 | 1743 | this_order); |
320ae51f JA |
1744 | if (page) |
1745 | break; | |
1746 | if (!this_order--) | |
1747 | break; | |
1748 | if (order_to_size(this_order) < rq_size) | |
1749 | break; | |
1750 | } while (1); | |
1751 | ||
1752 | if (!page) | |
24d2f903 | 1753 | goto fail; |
320ae51f JA |
1754 | |
1755 | page->private = this_order; | |
24d2f903 | 1756 | list_add_tail(&page->lru, &tags->page_list); |
320ae51f JA |
1757 | |
1758 | p = page_address(page); | |
f75782e4 CM |
1759 | /* |
1760 | * Allow kmemleak to scan these pages as they contain pointers | |
1761 | * to additional allocations like via ops->init_request(). | |
1762 | */ | |
36e1f3d1 | 1763 | kmemleak_alloc(p, order_to_size(this_order), 1, GFP_NOIO); |
320ae51f | 1764 | entries_per_page = order_to_size(this_order) / rq_size; |
cc71a6f4 | 1765 | to_do = min(entries_per_page, depth - i); |
320ae51f JA |
1766 | left -= to_do * rq_size; |
1767 | for (j = 0; j < to_do; j++) { | |
2af8cbe3 JA |
1768 | struct request *rq = p; |
1769 | ||
1770 | tags->static_rqs[i] = rq; | |
24d2f903 CH |
1771 | if (set->ops->init_request) { |
1772 | if (set->ops->init_request(set->driver_data, | |
2af8cbe3 | 1773 | rq, hctx_idx, i, |
59f082e4 | 1774 | node)) { |
2af8cbe3 | 1775 | tags->static_rqs[i] = NULL; |
24d2f903 | 1776 | goto fail; |
a5164405 | 1777 | } |
e9b267d9 CH |
1778 | } |
1779 | ||
320ae51f JA |
1780 | p += rq_size; |
1781 | i++; | |
1782 | } | |
1783 | } | |
cc71a6f4 | 1784 | return 0; |
320ae51f | 1785 | |
24d2f903 | 1786 | fail: |
cc71a6f4 JA |
1787 | blk_mq_free_rqs(set, tags, hctx_idx); |
1788 | return -ENOMEM; | |
320ae51f JA |
1789 | } |
1790 | ||
e57690fe JA |
1791 | /* |
1792 | * 'cpu' is going away. splice any existing rq_list entries from this | |
1793 | * software queue to the hw queue dispatch list, and ensure that it | |
1794 | * gets run. | |
1795 | */ | |
9467f859 | 1796 | static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node) |
484b4061 | 1797 | { |
9467f859 | 1798 | struct blk_mq_hw_ctx *hctx; |
484b4061 JA |
1799 | struct blk_mq_ctx *ctx; |
1800 | LIST_HEAD(tmp); | |
1801 | ||
9467f859 | 1802 | hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_dead); |
e57690fe | 1803 | ctx = __blk_mq_get_ctx(hctx->queue, cpu); |
484b4061 JA |
1804 | |
1805 | spin_lock(&ctx->lock); | |
1806 | if (!list_empty(&ctx->rq_list)) { | |
1807 | list_splice_init(&ctx->rq_list, &tmp); | |
1808 | blk_mq_hctx_clear_pending(hctx, ctx); | |
1809 | } | |
1810 | spin_unlock(&ctx->lock); | |
1811 | ||
1812 | if (list_empty(&tmp)) | |
9467f859 | 1813 | return 0; |
484b4061 | 1814 | |
e57690fe JA |
1815 | spin_lock(&hctx->lock); |
1816 | list_splice_tail_init(&tmp, &hctx->dispatch); | |
1817 | spin_unlock(&hctx->lock); | |
484b4061 JA |
1818 | |
1819 | blk_mq_run_hw_queue(hctx, true); | |
9467f859 | 1820 | return 0; |
484b4061 JA |
1821 | } |
1822 | ||
9467f859 | 1823 | static void blk_mq_remove_cpuhp(struct blk_mq_hw_ctx *hctx) |
484b4061 | 1824 | { |
9467f859 TG |
1825 | cpuhp_state_remove_instance_nocalls(CPUHP_BLK_MQ_DEAD, |
1826 | &hctx->cpuhp_dead); | |
484b4061 JA |
1827 | } |
1828 | ||
c3b4afca | 1829 | /* hctx->ctxs will be freed in queue's release handler */ |
08e98fc6 ML |
1830 | static void blk_mq_exit_hctx(struct request_queue *q, |
1831 | struct blk_mq_tag_set *set, | |
1832 | struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) | |
1833 | { | |
f70ced09 ML |
1834 | unsigned flush_start_tag = set->queue_depth; |
1835 | ||
08e98fc6 ML |
1836 | blk_mq_tag_idle(hctx); |
1837 | ||
f70ced09 ML |
1838 | if (set->ops->exit_request) |
1839 | set->ops->exit_request(set->driver_data, | |
1840 | hctx->fq->flush_rq, hctx_idx, | |
1841 | flush_start_tag + hctx_idx); | |
1842 | ||
93252632 OS |
1843 | blk_mq_sched_exit_hctx(q, hctx, hctx_idx); |
1844 | ||
08e98fc6 ML |
1845 | if (set->ops->exit_hctx) |
1846 | set->ops->exit_hctx(hctx, hctx_idx); | |
1847 | ||
6a83e74d BVA |
1848 | if (hctx->flags & BLK_MQ_F_BLOCKING) |
1849 | cleanup_srcu_struct(&hctx->queue_rq_srcu); | |
1850 | ||
9467f859 | 1851 | blk_mq_remove_cpuhp(hctx); |
f70ced09 | 1852 | blk_free_flush_queue(hctx->fq); |
88459642 | 1853 | sbitmap_free(&hctx->ctx_map); |
08e98fc6 ML |
1854 | } |
1855 | ||
624dbe47 ML |
1856 | static void blk_mq_exit_hw_queues(struct request_queue *q, |
1857 | struct blk_mq_tag_set *set, int nr_queue) | |
1858 | { | |
1859 | struct blk_mq_hw_ctx *hctx; | |
1860 | unsigned int i; | |
1861 | ||
1862 | queue_for_each_hw_ctx(q, hctx, i) { | |
1863 | if (i == nr_queue) | |
1864 | break; | |
08e98fc6 | 1865 | blk_mq_exit_hctx(q, set, hctx, i); |
624dbe47 | 1866 | } |
624dbe47 ML |
1867 | } |
1868 | ||
08e98fc6 ML |
1869 | static int blk_mq_init_hctx(struct request_queue *q, |
1870 | struct blk_mq_tag_set *set, | |
1871 | struct blk_mq_hw_ctx *hctx, unsigned hctx_idx) | |
320ae51f | 1872 | { |
08e98fc6 | 1873 | int node; |
f70ced09 | 1874 | unsigned flush_start_tag = set->queue_depth; |
08e98fc6 ML |
1875 | |
1876 | node = hctx->numa_node; | |
1877 | if (node == NUMA_NO_NODE) | |
1878 | node = hctx->numa_node = set->numa_node; | |
1879 | ||
27489a3c | 1880 | INIT_WORK(&hctx->run_work, blk_mq_run_work_fn); |
7587a5ae | 1881 | INIT_DELAYED_WORK(&hctx->delayed_run_work, blk_mq_delayed_run_work_fn); |
08e98fc6 ML |
1882 | INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn); |
1883 | spin_lock_init(&hctx->lock); | |
1884 | INIT_LIST_HEAD(&hctx->dispatch); | |
1885 | hctx->queue = q; | |
1886 | hctx->queue_num = hctx_idx; | |
2404e607 | 1887 | hctx->flags = set->flags & ~BLK_MQ_F_TAG_SHARED; |
08e98fc6 | 1888 | |
9467f859 | 1889 | cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, &hctx->cpuhp_dead); |
08e98fc6 ML |
1890 | |
1891 | hctx->tags = set->tags[hctx_idx]; | |
320ae51f JA |
1892 | |
1893 | /* | |
08e98fc6 ML |
1894 | * Allocate space for all possible cpus to avoid allocation at |
1895 | * runtime | |
320ae51f | 1896 | */ |
08e98fc6 ML |
1897 | hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *), |
1898 | GFP_KERNEL, node); | |
1899 | if (!hctx->ctxs) | |
1900 | goto unregister_cpu_notifier; | |
320ae51f | 1901 | |
88459642 OS |
1902 | if (sbitmap_init_node(&hctx->ctx_map, nr_cpu_ids, ilog2(8), GFP_KERNEL, |
1903 | node)) | |
08e98fc6 | 1904 | goto free_ctxs; |
320ae51f | 1905 | |
08e98fc6 | 1906 | hctx->nr_ctx = 0; |
320ae51f | 1907 | |
08e98fc6 ML |
1908 | if (set->ops->init_hctx && |
1909 | set->ops->init_hctx(hctx, set->driver_data, hctx_idx)) | |
1910 | goto free_bitmap; | |
320ae51f | 1911 | |
93252632 OS |
1912 | if (blk_mq_sched_init_hctx(q, hctx, hctx_idx)) |
1913 | goto exit_hctx; | |
1914 | ||
f70ced09 ML |
1915 | hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size); |
1916 | if (!hctx->fq) | |
93252632 | 1917 | goto sched_exit_hctx; |
320ae51f | 1918 | |
f70ced09 ML |
1919 | if (set->ops->init_request && |
1920 | set->ops->init_request(set->driver_data, | |
1921 | hctx->fq->flush_rq, hctx_idx, | |
1922 | flush_start_tag + hctx_idx, node)) | |
1923 | goto free_fq; | |
320ae51f | 1924 | |
6a83e74d BVA |
1925 | if (hctx->flags & BLK_MQ_F_BLOCKING) |
1926 | init_srcu_struct(&hctx->queue_rq_srcu); | |
1927 | ||
08e98fc6 | 1928 | return 0; |
320ae51f | 1929 | |
f70ced09 ML |
1930 | free_fq: |
1931 | kfree(hctx->fq); | |
93252632 OS |
1932 | sched_exit_hctx: |
1933 | blk_mq_sched_exit_hctx(q, hctx, hctx_idx); | |
f70ced09 ML |
1934 | exit_hctx: |
1935 | if (set->ops->exit_hctx) | |
1936 | set->ops->exit_hctx(hctx, hctx_idx); | |
08e98fc6 | 1937 | free_bitmap: |
88459642 | 1938 | sbitmap_free(&hctx->ctx_map); |
08e98fc6 ML |
1939 | free_ctxs: |
1940 | kfree(hctx->ctxs); | |
1941 | unregister_cpu_notifier: | |
9467f859 | 1942 | blk_mq_remove_cpuhp(hctx); |
08e98fc6 ML |
1943 | return -1; |
1944 | } | |
320ae51f | 1945 | |
320ae51f JA |
1946 | static void blk_mq_init_cpu_queues(struct request_queue *q, |
1947 | unsigned int nr_hw_queues) | |
1948 | { | |
1949 | unsigned int i; | |
1950 | ||
1951 | for_each_possible_cpu(i) { | |
1952 | struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i); | |
1953 | struct blk_mq_hw_ctx *hctx; | |
1954 | ||
320ae51f JA |
1955 | __ctx->cpu = i; |
1956 | spin_lock_init(&__ctx->lock); | |
1957 | INIT_LIST_HEAD(&__ctx->rq_list); | |
1958 | __ctx->queue = q; | |
1959 | ||
1960 | /* If the cpu isn't online, the cpu is mapped to first hctx */ | |
320ae51f JA |
1961 | if (!cpu_online(i)) |
1962 | continue; | |
1963 | ||
7d7e0f90 | 1964 | hctx = blk_mq_map_queue(q, i); |
e4043dcf | 1965 | |
320ae51f JA |
1966 | /* |
1967 | * Set local node, IFF we have more than one hw queue. If | |
1968 | * not, we remain on the home node of the device | |
1969 | */ | |
1970 | if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE) | |
bffed457 | 1971 | hctx->numa_node = local_memory_node(cpu_to_node(i)); |
320ae51f JA |
1972 | } |
1973 | } | |
1974 | ||
cc71a6f4 JA |
1975 | static bool __blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, int hctx_idx) |
1976 | { | |
1977 | int ret = 0; | |
1978 | ||
1979 | set->tags[hctx_idx] = blk_mq_alloc_rq_map(set, hctx_idx, | |
1980 | set->queue_depth, set->reserved_tags); | |
1981 | if (!set->tags[hctx_idx]) | |
1982 | return false; | |
1983 | ||
1984 | ret = blk_mq_alloc_rqs(set, set->tags[hctx_idx], hctx_idx, | |
1985 | set->queue_depth); | |
1986 | if (!ret) | |
1987 | return true; | |
1988 | ||
1989 | blk_mq_free_rq_map(set->tags[hctx_idx]); | |
1990 | set->tags[hctx_idx] = NULL; | |
1991 | return false; | |
1992 | } | |
1993 | ||
1994 | static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set, | |
1995 | unsigned int hctx_idx) | |
1996 | { | |
bd166ef1 JA |
1997 | if (set->tags[hctx_idx]) { |
1998 | blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx); | |
1999 | blk_mq_free_rq_map(set->tags[hctx_idx]); | |
2000 | set->tags[hctx_idx] = NULL; | |
2001 | } | |
cc71a6f4 JA |
2002 | } |
2003 | ||
5778322e AM |
2004 | static void blk_mq_map_swqueue(struct request_queue *q, |
2005 | const struct cpumask *online_mask) | |
320ae51f | 2006 | { |
d1b1cea1 | 2007 | unsigned int i, hctx_idx; |
320ae51f JA |
2008 | struct blk_mq_hw_ctx *hctx; |
2009 | struct blk_mq_ctx *ctx; | |
2a34c087 | 2010 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 2011 | |
60de074b AM |
2012 | /* |
2013 | * Avoid others reading imcomplete hctx->cpumask through sysfs | |
2014 | */ | |
2015 | mutex_lock(&q->sysfs_lock); | |
2016 | ||
320ae51f | 2017 | queue_for_each_hw_ctx(q, hctx, i) { |
e4043dcf | 2018 | cpumask_clear(hctx->cpumask); |
320ae51f JA |
2019 | hctx->nr_ctx = 0; |
2020 | } | |
2021 | ||
2022 | /* | |
2023 | * Map software to hardware queues | |
2024 | */ | |
897bb0c7 | 2025 | for_each_possible_cpu(i) { |
320ae51f | 2026 | /* If the cpu isn't online, the cpu is mapped to first hctx */ |
5778322e | 2027 | if (!cpumask_test_cpu(i, online_mask)) |
e4043dcf JA |
2028 | continue; |
2029 | ||
d1b1cea1 GKB |
2030 | hctx_idx = q->mq_map[i]; |
2031 | /* unmapped hw queue can be remapped after CPU topo changed */ | |
cc71a6f4 JA |
2032 | if (!set->tags[hctx_idx] && |
2033 | !__blk_mq_alloc_rq_map(set, hctx_idx)) { | |
d1b1cea1 GKB |
2034 | /* |
2035 | * If tags initialization fail for some hctx, | |
2036 | * that hctx won't be brought online. In this | |
2037 | * case, remap the current ctx to hctx[0] which | |
2038 | * is guaranteed to always have tags allocated | |
2039 | */ | |
cc71a6f4 | 2040 | q->mq_map[i] = 0; |
d1b1cea1 GKB |
2041 | } |
2042 | ||
897bb0c7 | 2043 | ctx = per_cpu_ptr(q->queue_ctx, i); |
7d7e0f90 | 2044 | hctx = blk_mq_map_queue(q, i); |
868f2f0b | 2045 | |
e4043dcf | 2046 | cpumask_set_cpu(i, hctx->cpumask); |
320ae51f JA |
2047 | ctx->index_hw = hctx->nr_ctx; |
2048 | hctx->ctxs[hctx->nr_ctx++] = ctx; | |
2049 | } | |
506e931f | 2050 | |
60de074b AM |
2051 | mutex_unlock(&q->sysfs_lock); |
2052 | ||
506e931f | 2053 | queue_for_each_hw_ctx(q, hctx, i) { |
484b4061 | 2054 | /* |
a68aafa5 JA |
2055 | * If no software queues are mapped to this hardware queue, |
2056 | * disable it and free the request entries. | |
484b4061 JA |
2057 | */ |
2058 | if (!hctx->nr_ctx) { | |
d1b1cea1 GKB |
2059 | /* Never unmap queue 0. We need it as a |
2060 | * fallback in case of a new remap fails | |
2061 | * allocation | |
2062 | */ | |
cc71a6f4 JA |
2063 | if (i && set->tags[i]) |
2064 | blk_mq_free_map_and_requests(set, i); | |
2065 | ||
2a34c087 | 2066 | hctx->tags = NULL; |
484b4061 JA |
2067 | continue; |
2068 | } | |
2069 | ||
2a34c087 ML |
2070 | hctx->tags = set->tags[i]; |
2071 | WARN_ON(!hctx->tags); | |
2072 | ||
889fa31f CY |
2073 | /* |
2074 | * Set the map size to the number of mapped software queues. | |
2075 | * This is more accurate and more efficient than looping | |
2076 | * over all possibly mapped software queues. | |
2077 | */ | |
88459642 | 2078 | sbitmap_resize(&hctx->ctx_map, hctx->nr_ctx); |
889fa31f | 2079 | |
484b4061 JA |
2080 | /* |
2081 | * Initialize batch roundrobin counts | |
2082 | */ | |
506e931f JA |
2083 | hctx->next_cpu = cpumask_first(hctx->cpumask); |
2084 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
2085 | } | |
320ae51f JA |
2086 | } |
2087 | ||
2404e607 | 2088 | static void queue_set_hctx_shared(struct request_queue *q, bool shared) |
0d2602ca JA |
2089 | { |
2090 | struct blk_mq_hw_ctx *hctx; | |
0d2602ca JA |
2091 | int i; |
2092 | ||
2404e607 JM |
2093 | queue_for_each_hw_ctx(q, hctx, i) { |
2094 | if (shared) | |
2095 | hctx->flags |= BLK_MQ_F_TAG_SHARED; | |
2096 | else | |
2097 | hctx->flags &= ~BLK_MQ_F_TAG_SHARED; | |
2098 | } | |
2099 | } | |
2100 | ||
2101 | static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set, bool shared) | |
2102 | { | |
2103 | struct request_queue *q; | |
0d2602ca | 2104 | |
705cda97 BVA |
2105 | lockdep_assert_held(&set->tag_list_lock); |
2106 | ||
0d2602ca JA |
2107 | list_for_each_entry(q, &set->tag_list, tag_set_list) { |
2108 | blk_mq_freeze_queue(q); | |
2404e607 | 2109 | queue_set_hctx_shared(q, shared); |
0d2602ca JA |
2110 | blk_mq_unfreeze_queue(q); |
2111 | } | |
2112 | } | |
2113 | ||
2114 | static void blk_mq_del_queue_tag_set(struct request_queue *q) | |
2115 | { | |
2116 | struct blk_mq_tag_set *set = q->tag_set; | |
2117 | ||
0d2602ca | 2118 | mutex_lock(&set->tag_list_lock); |
705cda97 BVA |
2119 | list_del_rcu(&q->tag_set_list); |
2120 | INIT_LIST_HEAD(&q->tag_set_list); | |
2404e607 JM |
2121 | if (list_is_singular(&set->tag_list)) { |
2122 | /* just transitioned to unshared */ | |
2123 | set->flags &= ~BLK_MQ_F_TAG_SHARED; | |
2124 | /* update existing queue */ | |
2125 | blk_mq_update_tag_set_depth(set, false); | |
2126 | } | |
0d2602ca | 2127 | mutex_unlock(&set->tag_list_lock); |
705cda97 BVA |
2128 | |
2129 | synchronize_rcu(); | |
0d2602ca JA |
2130 | } |
2131 | ||
2132 | static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, | |
2133 | struct request_queue *q) | |
2134 | { | |
2135 | q->tag_set = set; | |
2136 | ||
2137 | mutex_lock(&set->tag_list_lock); | |
2404e607 JM |
2138 | |
2139 | /* Check to see if we're transitioning to shared (from 1 to 2 queues). */ | |
2140 | if (!list_empty(&set->tag_list) && !(set->flags & BLK_MQ_F_TAG_SHARED)) { | |
2141 | set->flags |= BLK_MQ_F_TAG_SHARED; | |
2142 | /* update existing queue */ | |
2143 | blk_mq_update_tag_set_depth(set, true); | |
2144 | } | |
2145 | if (set->flags & BLK_MQ_F_TAG_SHARED) | |
2146 | queue_set_hctx_shared(q, true); | |
705cda97 | 2147 | list_add_tail_rcu(&q->tag_set_list, &set->tag_list); |
2404e607 | 2148 | |
0d2602ca JA |
2149 | mutex_unlock(&set->tag_list_lock); |
2150 | } | |
2151 | ||
e09aae7e ML |
2152 | /* |
2153 | * It is the actual release handler for mq, but we do it from | |
2154 | * request queue's release handler for avoiding use-after-free | |
2155 | * and headache because q->mq_kobj shouldn't have been introduced, | |
2156 | * but we can't group ctx/kctx kobj without it. | |
2157 | */ | |
2158 | void blk_mq_release(struct request_queue *q) | |
2159 | { | |
2160 | struct blk_mq_hw_ctx *hctx; | |
2161 | unsigned int i; | |
2162 | ||
2163 | /* hctx kobj stays in hctx */ | |
c3b4afca ML |
2164 | queue_for_each_hw_ctx(q, hctx, i) { |
2165 | if (!hctx) | |
2166 | continue; | |
6c8b232e | 2167 | kobject_put(&hctx->kobj); |
c3b4afca | 2168 | } |
e09aae7e | 2169 | |
a723bab3 AM |
2170 | q->mq_map = NULL; |
2171 | ||
e09aae7e ML |
2172 | kfree(q->queue_hw_ctx); |
2173 | ||
7ea5fe31 ML |
2174 | /* |
2175 | * release .mq_kobj and sw queue's kobject now because | |
2176 | * both share lifetime with request queue. | |
2177 | */ | |
2178 | blk_mq_sysfs_deinit(q); | |
2179 | ||
e09aae7e ML |
2180 | free_percpu(q->queue_ctx); |
2181 | } | |
2182 | ||
24d2f903 | 2183 | struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) |
b62c21b7 MS |
2184 | { |
2185 | struct request_queue *uninit_q, *q; | |
2186 | ||
2187 | uninit_q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node); | |
2188 | if (!uninit_q) | |
2189 | return ERR_PTR(-ENOMEM); | |
2190 | ||
2191 | q = blk_mq_init_allocated_queue(set, uninit_q); | |
2192 | if (IS_ERR(q)) | |
2193 | blk_cleanup_queue(uninit_q); | |
2194 | ||
2195 | return q; | |
2196 | } | |
2197 | EXPORT_SYMBOL(blk_mq_init_queue); | |
2198 | ||
868f2f0b KB |
2199 | static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, |
2200 | struct request_queue *q) | |
320ae51f | 2201 | { |
868f2f0b KB |
2202 | int i, j; |
2203 | struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx; | |
f14bbe77 | 2204 | |
868f2f0b | 2205 | blk_mq_sysfs_unregister(q); |
24d2f903 | 2206 | for (i = 0; i < set->nr_hw_queues; i++) { |
868f2f0b | 2207 | int node; |
f14bbe77 | 2208 | |
868f2f0b KB |
2209 | if (hctxs[i]) |
2210 | continue; | |
2211 | ||
2212 | node = blk_mq_hw_queue_to_node(q->mq_map, i); | |
cdef54dd CH |
2213 | hctxs[i] = kzalloc_node(sizeof(struct blk_mq_hw_ctx), |
2214 | GFP_KERNEL, node); | |
320ae51f | 2215 | if (!hctxs[i]) |
868f2f0b | 2216 | break; |
320ae51f | 2217 | |
a86073e4 | 2218 | if (!zalloc_cpumask_var_node(&hctxs[i]->cpumask, GFP_KERNEL, |
868f2f0b KB |
2219 | node)) { |
2220 | kfree(hctxs[i]); | |
2221 | hctxs[i] = NULL; | |
2222 | break; | |
2223 | } | |
e4043dcf | 2224 | |
0d2602ca | 2225 | atomic_set(&hctxs[i]->nr_active, 0); |
f14bbe77 | 2226 | hctxs[i]->numa_node = node; |
320ae51f | 2227 | hctxs[i]->queue_num = i; |
868f2f0b KB |
2228 | |
2229 | if (blk_mq_init_hctx(q, set, hctxs[i], i)) { | |
2230 | free_cpumask_var(hctxs[i]->cpumask); | |
2231 | kfree(hctxs[i]); | |
2232 | hctxs[i] = NULL; | |
2233 | break; | |
2234 | } | |
2235 | blk_mq_hctx_kobj_init(hctxs[i]); | |
320ae51f | 2236 | } |
868f2f0b KB |
2237 | for (j = i; j < q->nr_hw_queues; j++) { |
2238 | struct blk_mq_hw_ctx *hctx = hctxs[j]; | |
2239 | ||
2240 | if (hctx) { | |
cc71a6f4 JA |
2241 | if (hctx->tags) |
2242 | blk_mq_free_map_and_requests(set, j); | |
868f2f0b | 2243 | blk_mq_exit_hctx(q, set, hctx, j); |
868f2f0b | 2244 | kobject_put(&hctx->kobj); |
868f2f0b KB |
2245 | hctxs[j] = NULL; |
2246 | ||
2247 | } | |
2248 | } | |
2249 | q->nr_hw_queues = i; | |
2250 | blk_mq_sysfs_register(q); | |
2251 | } | |
2252 | ||
2253 | struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, | |
2254 | struct request_queue *q) | |
2255 | { | |
66841672 ML |
2256 | /* mark the queue as mq asap */ |
2257 | q->mq_ops = set->ops; | |
2258 | ||
34dbad5d OS |
2259 | q->poll_cb = blk_stat_alloc_callback(blk_mq_poll_stats_fn, |
2260 | blk_stat_rq_ddir, 2, q); | |
2261 | if (!q->poll_cb) | |
2262 | goto err_exit; | |
2263 | ||
868f2f0b KB |
2264 | q->queue_ctx = alloc_percpu(struct blk_mq_ctx); |
2265 | if (!q->queue_ctx) | |
c7de5726 | 2266 | goto err_exit; |
868f2f0b | 2267 | |
737f98cf ML |
2268 | /* init q->mq_kobj and sw queues' kobjects */ |
2269 | blk_mq_sysfs_init(q); | |
2270 | ||
868f2f0b KB |
2271 | q->queue_hw_ctx = kzalloc_node(nr_cpu_ids * sizeof(*(q->queue_hw_ctx)), |
2272 | GFP_KERNEL, set->numa_node); | |
2273 | if (!q->queue_hw_ctx) | |
2274 | goto err_percpu; | |
2275 | ||
bdd17e75 | 2276 | q->mq_map = set->mq_map; |
868f2f0b KB |
2277 | |
2278 | blk_mq_realloc_hw_ctxs(set, q); | |
2279 | if (!q->nr_hw_queues) | |
2280 | goto err_hctxs; | |
320ae51f | 2281 | |
287922eb | 2282 | INIT_WORK(&q->timeout_work, blk_mq_timeout_work); |
e56f698b | 2283 | blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ); |
320ae51f JA |
2284 | |
2285 | q->nr_queues = nr_cpu_ids; | |
320ae51f | 2286 | |
94eddfbe | 2287 | q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; |
320ae51f | 2288 | |
05f1dd53 JA |
2289 | if (!(set->flags & BLK_MQ_F_SG_MERGE)) |
2290 | q->queue_flags |= 1 << QUEUE_FLAG_NO_SG_MERGE; | |
2291 | ||
1be036e9 CH |
2292 | q->sg_reserved_size = INT_MAX; |
2293 | ||
2849450a | 2294 | INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work); |
6fca6a61 CH |
2295 | INIT_LIST_HEAD(&q->requeue_list); |
2296 | spin_lock_init(&q->requeue_lock); | |
2297 | ||
254d259d | 2298 | blk_queue_make_request(q, blk_mq_make_request); |
07068d5b | 2299 | |
eba71768 JA |
2300 | /* |
2301 | * Do this after blk_queue_make_request() overrides it... | |
2302 | */ | |
2303 | q->nr_requests = set->queue_depth; | |
2304 | ||
64f1c21e JA |
2305 | /* |
2306 | * Default to classic polling | |
2307 | */ | |
2308 | q->poll_nsec = -1; | |
2309 | ||
24d2f903 CH |
2310 | if (set->ops->complete) |
2311 | blk_queue_softirq_done(q, set->ops->complete); | |
30a91cb4 | 2312 | |
24d2f903 | 2313 | blk_mq_init_cpu_queues(q, set->nr_hw_queues); |
320ae51f | 2314 | |
5778322e | 2315 | get_online_cpus(); |
320ae51f | 2316 | mutex_lock(&all_q_mutex); |
320ae51f | 2317 | |
4593fdbe | 2318 | list_add_tail(&q->all_q_node, &all_q_list); |
0d2602ca | 2319 | blk_mq_add_queue_tag_set(set, q); |
5778322e | 2320 | blk_mq_map_swqueue(q, cpu_online_mask); |
484b4061 | 2321 | |
4593fdbe | 2322 | mutex_unlock(&all_q_mutex); |
5778322e | 2323 | put_online_cpus(); |
4593fdbe | 2324 | |
d3484991 JA |
2325 | if (!(set->flags & BLK_MQ_F_NO_SCHED)) { |
2326 | int ret; | |
2327 | ||
2328 | ret = blk_mq_sched_init(q); | |
2329 | if (ret) | |
2330 | return ERR_PTR(ret); | |
2331 | } | |
2332 | ||
320ae51f | 2333 | return q; |
18741986 | 2334 | |
320ae51f | 2335 | err_hctxs: |
868f2f0b | 2336 | kfree(q->queue_hw_ctx); |
320ae51f | 2337 | err_percpu: |
868f2f0b | 2338 | free_percpu(q->queue_ctx); |
c7de5726 ML |
2339 | err_exit: |
2340 | q->mq_ops = NULL; | |
320ae51f JA |
2341 | return ERR_PTR(-ENOMEM); |
2342 | } | |
b62c21b7 | 2343 | EXPORT_SYMBOL(blk_mq_init_allocated_queue); |
320ae51f JA |
2344 | |
2345 | void blk_mq_free_queue(struct request_queue *q) | |
2346 | { | |
624dbe47 | 2347 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 2348 | |
0e626368 AM |
2349 | mutex_lock(&all_q_mutex); |
2350 | list_del_init(&q->all_q_node); | |
2351 | mutex_unlock(&all_q_mutex); | |
2352 | ||
0d2602ca JA |
2353 | blk_mq_del_queue_tag_set(q); |
2354 | ||
624dbe47 | 2355 | blk_mq_exit_hw_queues(q, set, set->nr_hw_queues); |
320ae51f | 2356 | } |
320ae51f JA |
2357 | |
2358 | /* Basically redo blk_mq_init_queue with queue frozen */ | |
5778322e AM |
2359 | static void blk_mq_queue_reinit(struct request_queue *q, |
2360 | const struct cpumask *online_mask) | |
320ae51f | 2361 | { |
4ecd4fef | 2362 | WARN_ON_ONCE(!atomic_read(&q->mq_freeze_depth)); |
320ae51f | 2363 | |
67aec14c JA |
2364 | blk_mq_sysfs_unregister(q); |
2365 | ||
320ae51f JA |
2366 | /* |
2367 | * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe | |
2368 | * we should change hctx numa_node according to new topology (this | |
2369 | * involves free and re-allocate memory, worthy doing?) | |
2370 | */ | |
2371 | ||
5778322e | 2372 | blk_mq_map_swqueue(q, online_mask); |
320ae51f | 2373 | |
67aec14c | 2374 | blk_mq_sysfs_register(q); |
320ae51f JA |
2375 | } |
2376 | ||
65d5291e SAS |
2377 | /* |
2378 | * New online cpumask which is going to be set in this hotplug event. | |
2379 | * Declare this cpumasks as global as cpu-hotplug operation is invoked | |
2380 | * one-by-one and dynamically allocating this could result in a failure. | |
2381 | */ | |
2382 | static struct cpumask cpuhp_online_new; | |
2383 | ||
2384 | static void blk_mq_queue_reinit_work(void) | |
320ae51f JA |
2385 | { |
2386 | struct request_queue *q; | |
320ae51f JA |
2387 | |
2388 | mutex_lock(&all_q_mutex); | |
f3af020b TH |
2389 | /* |
2390 | * We need to freeze and reinit all existing queues. Freezing | |
2391 | * involves synchronous wait for an RCU grace period and doing it | |
2392 | * one by one may take a long time. Start freezing all queues in | |
2393 | * one swoop and then wait for the completions so that freezing can | |
2394 | * take place in parallel. | |
2395 | */ | |
2396 | list_for_each_entry(q, &all_q_list, all_q_node) | |
1671d522 | 2397 | blk_freeze_queue_start(q); |
415d3dab | 2398 | list_for_each_entry(q, &all_q_list, all_q_node) |
f3af020b TH |
2399 | blk_mq_freeze_queue_wait(q); |
2400 | ||
320ae51f | 2401 | list_for_each_entry(q, &all_q_list, all_q_node) |
65d5291e | 2402 | blk_mq_queue_reinit(q, &cpuhp_online_new); |
f3af020b TH |
2403 | |
2404 | list_for_each_entry(q, &all_q_list, all_q_node) | |
2405 | blk_mq_unfreeze_queue(q); | |
2406 | ||
320ae51f | 2407 | mutex_unlock(&all_q_mutex); |
65d5291e SAS |
2408 | } |
2409 | ||
2410 | static int blk_mq_queue_reinit_dead(unsigned int cpu) | |
2411 | { | |
97a32864 | 2412 | cpumask_copy(&cpuhp_online_new, cpu_online_mask); |
65d5291e SAS |
2413 | blk_mq_queue_reinit_work(); |
2414 | return 0; | |
2415 | } | |
2416 | ||
2417 | /* | |
2418 | * Before hotadded cpu starts handling requests, new mappings must be | |
2419 | * established. Otherwise, these requests in hw queue might never be | |
2420 | * dispatched. | |
2421 | * | |
2422 | * For example, there is a single hw queue (hctx) and two CPU queues (ctx0 | |
2423 | * for CPU0, and ctx1 for CPU1). | |
2424 | * | |
2425 | * Now CPU1 is just onlined and a request is inserted into ctx1->rq_list | |
2426 | * and set bit0 in pending bitmap as ctx1->index_hw is still zero. | |
2427 | * | |
2c3ad667 JA |
2428 | * And then while running hw queue, blk_mq_flush_busy_ctxs() finds bit0 is set |
2429 | * in pending bitmap and tries to retrieve requests in hctx->ctxs[0]->rq_list. | |
2430 | * But htx->ctxs[0] is a pointer to ctx0, so the request in ctx1->rq_list is | |
2431 | * ignored. | |
65d5291e SAS |
2432 | */ |
2433 | static int blk_mq_queue_reinit_prepare(unsigned int cpu) | |
2434 | { | |
2435 | cpumask_copy(&cpuhp_online_new, cpu_online_mask); | |
2436 | cpumask_set_cpu(cpu, &cpuhp_online_new); | |
2437 | blk_mq_queue_reinit_work(); | |
2438 | return 0; | |
320ae51f JA |
2439 | } |
2440 | ||
a5164405 JA |
2441 | static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) |
2442 | { | |
2443 | int i; | |
2444 | ||
cc71a6f4 JA |
2445 | for (i = 0; i < set->nr_hw_queues; i++) |
2446 | if (!__blk_mq_alloc_rq_map(set, i)) | |
a5164405 | 2447 | goto out_unwind; |
a5164405 JA |
2448 | |
2449 | return 0; | |
2450 | ||
2451 | out_unwind: | |
2452 | while (--i >= 0) | |
cc71a6f4 | 2453 | blk_mq_free_rq_map(set->tags[i]); |
a5164405 | 2454 | |
a5164405 JA |
2455 | return -ENOMEM; |
2456 | } | |
2457 | ||
2458 | /* | |
2459 | * Allocate the request maps associated with this tag_set. Note that this | |
2460 | * may reduce the depth asked for, if memory is tight. set->queue_depth | |
2461 | * will be updated to reflect the allocated depth. | |
2462 | */ | |
2463 | static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) | |
2464 | { | |
2465 | unsigned int depth; | |
2466 | int err; | |
2467 | ||
2468 | depth = set->queue_depth; | |
2469 | do { | |
2470 | err = __blk_mq_alloc_rq_maps(set); | |
2471 | if (!err) | |
2472 | break; | |
2473 | ||
2474 | set->queue_depth >>= 1; | |
2475 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) { | |
2476 | err = -ENOMEM; | |
2477 | break; | |
2478 | } | |
2479 | } while (set->queue_depth); | |
2480 | ||
2481 | if (!set->queue_depth || err) { | |
2482 | pr_err("blk-mq: failed to allocate request map\n"); | |
2483 | return -ENOMEM; | |
2484 | } | |
2485 | ||
2486 | if (depth != set->queue_depth) | |
2487 | pr_info("blk-mq: reduced tag depth (%u -> %u)\n", | |
2488 | depth, set->queue_depth); | |
2489 | ||
2490 | return 0; | |
2491 | } | |
2492 | ||
ebe8bddb OS |
2493 | static int blk_mq_update_queue_map(struct blk_mq_tag_set *set) |
2494 | { | |
2495 | if (set->ops->map_queues) | |
2496 | return set->ops->map_queues(set); | |
2497 | else | |
2498 | return blk_mq_map_queues(set); | |
2499 | } | |
2500 | ||
a4391c64 JA |
2501 | /* |
2502 | * Alloc a tag set to be associated with one or more request queues. | |
2503 | * May fail with EINVAL for various error conditions. May adjust the | |
2504 | * requested depth down, if if it too large. In that case, the set | |
2505 | * value will be stored in set->queue_depth. | |
2506 | */ | |
24d2f903 CH |
2507 | int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) |
2508 | { | |
da695ba2 CH |
2509 | int ret; |
2510 | ||
205fb5f5 BVA |
2511 | BUILD_BUG_ON(BLK_MQ_MAX_DEPTH > 1 << BLK_MQ_UNIQUE_TAG_BITS); |
2512 | ||
24d2f903 CH |
2513 | if (!set->nr_hw_queues) |
2514 | return -EINVAL; | |
a4391c64 | 2515 | if (!set->queue_depth) |
24d2f903 CH |
2516 | return -EINVAL; |
2517 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) | |
2518 | return -EINVAL; | |
2519 | ||
7d7e0f90 | 2520 | if (!set->ops->queue_rq) |
24d2f903 CH |
2521 | return -EINVAL; |
2522 | ||
a4391c64 JA |
2523 | if (set->queue_depth > BLK_MQ_MAX_DEPTH) { |
2524 | pr_info("blk-mq: reduced tag depth to %u\n", | |
2525 | BLK_MQ_MAX_DEPTH); | |
2526 | set->queue_depth = BLK_MQ_MAX_DEPTH; | |
2527 | } | |
24d2f903 | 2528 | |
6637fadf SL |
2529 | /* |
2530 | * If a crashdump is active, then we are potentially in a very | |
2531 | * memory constrained environment. Limit us to 1 queue and | |
2532 | * 64 tags to prevent using too much memory. | |
2533 | */ | |
2534 | if (is_kdump_kernel()) { | |
2535 | set->nr_hw_queues = 1; | |
2536 | set->queue_depth = min(64U, set->queue_depth); | |
2537 | } | |
868f2f0b KB |
2538 | /* |
2539 | * There is no use for more h/w queues than cpus. | |
2540 | */ | |
2541 | if (set->nr_hw_queues > nr_cpu_ids) | |
2542 | set->nr_hw_queues = nr_cpu_ids; | |
6637fadf | 2543 | |
868f2f0b | 2544 | set->tags = kzalloc_node(nr_cpu_ids * sizeof(struct blk_mq_tags *), |
24d2f903 CH |
2545 | GFP_KERNEL, set->numa_node); |
2546 | if (!set->tags) | |
a5164405 | 2547 | return -ENOMEM; |
24d2f903 | 2548 | |
da695ba2 CH |
2549 | ret = -ENOMEM; |
2550 | set->mq_map = kzalloc_node(sizeof(*set->mq_map) * nr_cpu_ids, | |
2551 | GFP_KERNEL, set->numa_node); | |
bdd17e75 CH |
2552 | if (!set->mq_map) |
2553 | goto out_free_tags; | |
2554 | ||
ebe8bddb | 2555 | ret = blk_mq_update_queue_map(set); |
da695ba2 CH |
2556 | if (ret) |
2557 | goto out_free_mq_map; | |
2558 | ||
2559 | ret = blk_mq_alloc_rq_maps(set); | |
2560 | if (ret) | |
bdd17e75 | 2561 | goto out_free_mq_map; |
24d2f903 | 2562 | |
0d2602ca JA |
2563 | mutex_init(&set->tag_list_lock); |
2564 | INIT_LIST_HEAD(&set->tag_list); | |
2565 | ||
24d2f903 | 2566 | return 0; |
bdd17e75 CH |
2567 | |
2568 | out_free_mq_map: | |
2569 | kfree(set->mq_map); | |
2570 | set->mq_map = NULL; | |
2571 | out_free_tags: | |
5676e7b6 RE |
2572 | kfree(set->tags); |
2573 | set->tags = NULL; | |
da695ba2 | 2574 | return ret; |
24d2f903 CH |
2575 | } |
2576 | EXPORT_SYMBOL(blk_mq_alloc_tag_set); | |
2577 | ||
2578 | void blk_mq_free_tag_set(struct blk_mq_tag_set *set) | |
2579 | { | |
2580 | int i; | |
2581 | ||
cc71a6f4 JA |
2582 | for (i = 0; i < nr_cpu_ids; i++) |
2583 | blk_mq_free_map_and_requests(set, i); | |
484b4061 | 2584 | |
bdd17e75 CH |
2585 | kfree(set->mq_map); |
2586 | set->mq_map = NULL; | |
2587 | ||
981bd189 | 2588 | kfree(set->tags); |
5676e7b6 | 2589 | set->tags = NULL; |
24d2f903 CH |
2590 | } |
2591 | EXPORT_SYMBOL(blk_mq_free_tag_set); | |
2592 | ||
e3a2b3f9 JA |
2593 | int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) |
2594 | { | |
2595 | struct blk_mq_tag_set *set = q->tag_set; | |
2596 | struct blk_mq_hw_ctx *hctx; | |
2597 | int i, ret; | |
2598 | ||
bd166ef1 | 2599 | if (!set) |
e3a2b3f9 JA |
2600 | return -EINVAL; |
2601 | ||
70f36b60 JA |
2602 | blk_mq_freeze_queue(q); |
2603 | blk_mq_quiesce_queue(q); | |
2604 | ||
e3a2b3f9 JA |
2605 | ret = 0; |
2606 | queue_for_each_hw_ctx(q, hctx, i) { | |
e9137d4b KB |
2607 | if (!hctx->tags) |
2608 | continue; | |
bd166ef1 JA |
2609 | /* |
2610 | * If we're using an MQ scheduler, just update the scheduler | |
2611 | * queue depth. This is similar to what the old code would do. | |
2612 | */ | |
70f36b60 JA |
2613 | if (!hctx->sched_tags) { |
2614 | ret = blk_mq_tag_update_depth(hctx, &hctx->tags, | |
2615 | min(nr, set->queue_depth), | |
2616 | false); | |
2617 | } else { | |
2618 | ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags, | |
2619 | nr, true); | |
2620 | } | |
e3a2b3f9 JA |
2621 | if (ret) |
2622 | break; | |
2623 | } | |
2624 | ||
2625 | if (!ret) | |
2626 | q->nr_requests = nr; | |
2627 | ||
70f36b60 JA |
2628 | blk_mq_unfreeze_queue(q); |
2629 | blk_mq_start_stopped_hw_queues(q, true); | |
2630 | ||
e3a2b3f9 JA |
2631 | return ret; |
2632 | } | |
2633 | ||
868f2f0b KB |
2634 | void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues) |
2635 | { | |
2636 | struct request_queue *q; | |
2637 | ||
705cda97 BVA |
2638 | lockdep_assert_held(&set->tag_list_lock); |
2639 | ||
868f2f0b KB |
2640 | if (nr_hw_queues > nr_cpu_ids) |
2641 | nr_hw_queues = nr_cpu_ids; | |
2642 | if (nr_hw_queues < 1 || nr_hw_queues == set->nr_hw_queues) | |
2643 | return; | |
2644 | ||
2645 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
2646 | blk_mq_freeze_queue(q); | |
2647 | ||
2648 | set->nr_hw_queues = nr_hw_queues; | |
ebe8bddb | 2649 | blk_mq_update_queue_map(set); |
868f2f0b KB |
2650 | list_for_each_entry(q, &set->tag_list, tag_set_list) { |
2651 | blk_mq_realloc_hw_ctxs(set, q); | |
868f2f0b KB |
2652 | blk_mq_queue_reinit(q, cpu_online_mask); |
2653 | } | |
2654 | ||
2655 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
2656 | blk_mq_unfreeze_queue(q); | |
2657 | } | |
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; | |
2686 | ||
2687 | if (cb->stat[READ].nr_samples) | |
2688 | q->poll_stat[READ] = cb->stat[READ]; | |
2689 | if (cb->stat[WRITE].nr_samples) | |
2690 | q->poll_stat[WRITE] = cb->stat[WRITE]; | |
2691 | } | |
2692 | ||
64f1c21e JA |
2693 | static unsigned long blk_mq_poll_nsecs(struct request_queue *q, |
2694 | struct blk_mq_hw_ctx *hctx, | |
2695 | struct request *rq) | |
2696 | { | |
64f1c21e JA |
2697 | unsigned long ret = 0; |
2698 | ||
2699 | /* | |
2700 | * If stats collection isn't on, don't sleep but turn it on for | |
2701 | * future users | |
2702 | */ | |
34dbad5d | 2703 | if (!blk_poll_stats_enable(q)) |
64f1c21e JA |
2704 | return 0; |
2705 | ||
64f1c21e JA |
2706 | /* |
2707 | * As an optimistic guess, use half of the mean service time | |
2708 | * for this type of request. We can (and should) make this smarter. | |
2709 | * For instance, if the completion latencies are tight, we can | |
2710 | * get closer than just half the mean. This is especially | |
2711 | * important on devices where the completion latencies are longer | |
2712 | * than ~10 usec. | |
2713 | */ | |
34dbad5d OS |
2714 | if (req_op(rq) == REQ_OP_READ && q->poll_stat[READ].nr_samples) |
2715 | ret = (q->poll_stat[READ].mean + 1) / 2; | |
2716 | else if (req_op(rq) == REQ_OP_WRITE && q->poll_stat[WRITE].nr_samples) | |
2717 | ret = (q->poll_stat[WRITE].mean + 1) / 2; | |
64f1c21e JA |
2718 | |
2719 | return ret; | |
2720 | } | |
2721 | ||
06426adf | 2722 | static bool blk_mq_poll_hybrid_sleep(struct request_queue *q, |
64f1c21e | 2723 | struct blk_mq_hw_ctx *hctx, |
06426adf JA |
2724 | struct request *rq) |
2725 | { | |
2726 | struct hrtimer_sleeper hs; | |
2727 | enum hrtimer_mode mode; | |
64f1c21e | 2728 | unsigned int nsecs; |
06426adf JA |
2729 | ktime_t kt; |
2730 | ||
64f1c21e JA |
2731 | if (test_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags)) |
2732 | return false; | |
2733 | ||
2734 | /* | |
2735 | * poll_nsec can be: | |
2736 | * | |
2737 | * -1: don't ever hybrid sleep | |
2738 | * 0: use half of prev avg | |
2739 | * >0: use this specific value | |
2740 | */ | |
2741 | if (q->poll_nsec == -1) | |
2742 | return false; | |
2743 | else if (q->poll_nsec > 0) | |
2744 | nsecs = q->poll_nsec; | |
2745 | else | |
2746 | nsecs = blk_mq_poll_nsecs(q, hctx, rq); | |
2747 | ||
2748 | if (!nsecs) | |
06426adf JA |
2749 | return false; |
2750 | ||
2751 | set_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags); | |
2752 | ||
2753 | /* | |
2754 | * This will be replaced with the stats tracking code, using | |
2755 | * 'avg_completion_time / 2' as the pre-sleep target. | |
2756 | */ | |
8b0e1953 | 2757 | kt = nsecs; |
06426adf JA |
2758 | |
2759 | mode = HRTIMER_MODE_REL; | |
2760 | hrtimer_init_on_stack(&hs.timer, CLOCK_MONOTONIC, mode); | |
2761 | hrtimer_set_expires(&hs.timer, kt); | |
2762 | ||
2763 | hrtimer_init_sleeper(&hs, current); | |
2764 | do { | |
2765 | if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) | |
2766 | break; | |
2767 | set_current_state(TASK_UNINTERRUPTIBLE); | |
2768 | hrtimer_start_expires(&hs.timer, mode); | |
2769 | if (hs.task) | |
2770 | io_schedule(); | |
2771 | hrtimer_cancel(&hs.timer); | |
2772 | mode = HRTIMER_MODE_ABS; | |
2773 | } while (hs.task && !signal_pending(current)); | |
2774 | ||
2775 | __set_current_state(TASK_RUNNING); | |
2776 | destroy_hrtimer_on_stack(&hs.timer); | |
2777 | return true; | |
2778 | } | |
2779 | ||
bbd7bb70 JA |
2780 | static bool __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq) |
2781 | { | |
2782 | struct request_queue *q = hctx->queue; | |
2783 | long state; | |
2784 | ||
06426adf JA |
2785 | /* |
2786 | * If we sleep, have the caller restart the poll loop to reset | |
2787 | * the state. Like for the other success return cases, the | |
2788 | * caller is responsible for checking if the IO completed. If | |
2789 | * the IO isn't complete, we'll get called again and will go | |
2790 | * straight to the busy poll loop. | |
2791 | */ | |
64f1c21e | 2792 | if (blk_mq_poll_hybrid_sleep(q, hctx, rq)) |
06426adf JA |
2793 | return true; |
2794 | ||
bbd7bb70 JA |
2795 | hctx->poll_considered++; |
2796 | ||
2797 | state = current->state; | |
2798 | while (!need_resched()) { | |
2799 | int ret; | |
2800 | ||
2801 | hctx->poll_invoked++; | |
2802 | ||
2803 | ret = q->mq_ops->poll(hctx, rq->tag); | |
2804 | if (ret > 0) { | |
2805 | hctx->poll_success++; | |
2806 | set_current_state(TASK_RUNNING); | |
2807 | return true; | |
2808 | } | |
2809 | ||
2810 | if (signal_pending_state(state, current)) | |
2811 | set_current_state(TASK_RUNNING); | |
2812 | ||
2813 | if (current->state == TASK_RUNNING) | |
2814 | return true; | |
2815 | if (ret < 0) | |
2816 | break; | |
2817 | cpu_relax(); | |
2818 | } | |
2819 | ||
2820 | return false; | |
2821 | } | |
2822 | ||
2823 | bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie) | |
2824 | { | |
2825 | struct blk_mq_hw_ctx *hctx; | |
2826 | struct blk_plug *plug; | |
2827 | struct request *rq; | |
2828 | ||
2829 | if (!q->mq_ops || !q->mq_ops->poll || !blk_qc_t_valid(cookie) || | |
2830 | !test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) | |
2831 | return false; | |
2832 | ||
2833 | plug = current->plug; | |
2834 | if (plug) | |
2835 | blk_flush_plug_list(plug, false); | |
2836 | ||
2837 | hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)]; | |
bd166ef1 JA |
2838 | if (!blk_qc_t_is_internal(cookie)) |
2839 | rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie)); | |
2840 | else | |
2841 | rq = blk_mq_tag_to_rq(hctx->sched_tags, blk_qc_t_to_tag(cookie)); | |
bbd7bb70 JA |
2842 | |
2843 | return __blk_mq_poll(hctx, rq); | |
2844 | } | |
2845 | EXPORT_SYMBOL_GPL(blk_mq_poll); | |
2846 | ||
676141e4 JA |
2847 | void blk_mq_disable_hotplug(void) |
2848 | { | |
2849 | mutex_lock(&all_q_mutex); | |
2850 | } | |
2851 | ||
2852 | void blk_mq_enable_hotplug(void) | |
2853 | { | |
2854 | mutex_unlock(&all_q_mutex); | |
2855 | } | |
2856 | ||
320ae51f JA |
2857 | static int __init blk_mq_init(void) |
2858 | { | |
9467f859 TG |
2859 | cpuhp_setup_state_multi(CPUHP_BLK_MQ_DEAD, "block/mq:dead", NULL, |
2860 | blk_mq_hctx_notify_dead); | |
320ae51f | 2861 | |
65d5291e SAS |
2862 | cpuhp_setup_state_nocalls(CPUHP_BLK_MQ_PREPARE, "block/mq:prepare", |
2863 | blk_mq_queue_reinit_prepare, | |
2864 | blk_mq_queue_reinit_dead); | |
320ae51f JA |
2865 | return 0; |
2866 | } | |
2867 | subsys_initcall(blk_mq_init); |