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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 | ||
320ae51f JA |
42 | /* |
43 | * Check if any of the ctx's have pending work in this hardware queue | |
44 | */ | |
50e1dab8 | 45 | bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx) |
320ae51f | 46 | { |
bd166ef1 JA |
47 | return sbitmap_any_bit_set(&hctx->ctx_map) || |
48 | !list_empty_careful(&hctx->dispatch) || | |
49 | blk_mq_sched_has_work(hctx); | |
1429d7c9 JA |
50 | } |
51 | ||
320ae51f JA |
52 | /* |
53 | * Mark this ctx as having pending work in this hardware queue | |
54 | */ | |
55 | static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx, | |
56 | struct blk_mq_ctx *ctx) | |
57 | { | |
88459642 OS |
58 | if (!sbitmap_test_bit(&hctx->ctx_map, ctx->index_hw)) |
59 | sbitmap_set_bit(&hctx->ctx_map, ctx->index_hw); | |
1429d7c9 JA |
60 | } |
61 | ||
62 | static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx, | |
63 | struct blk_mq_ctx *ctx) | |
64 | { | |
88459642 | 65 | sbitmap_clear_bit(&hctx->ctx_map, ctx->index_hw); |
320ae51f JA |
66 | } |
67 | ||
b4c6a028 | 68 | void blk_mq_freeze_queue_start(struct request_queue *q) |
43a5e4e2 | 69 | { |
4ecd4fef | 70 | int freeze_depth; |
cddd5d17 | 71 | |
4ecd4fef CH |
72 | freeze_depth = atomic_inc_return(&q->mq_freeze_depth); |
73 | if (freeze_depth == 1) { | |
3ef28e83 | 74 | percpu_ref_kill(&q->q_usage_counter); |
b94ec296 | 75 | blk_mq_run_hw_queues(q, false); |
cddd5d17 | 76 | } |
f3af020b | 77 | } |
b4c6a028 | 78 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_start); |
f3af020b TH |
79 | |
80 | static void blk_mq_freeze_queue_wait(struct request_queue *q) | |
81 | { | |
3ef28e83 | 82 | wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter)); |
43a5e4e2 ML |
83 | } |
84 | ||
f3af020b TH |
85 | /* |
86 | * Guarantee no request is in use, so we can change any data structure of | |
87 | * the queue afterward. | |
88 | */ | |
3ef28e83 | 89 | void blk_freeze_queue(struct request_queue *q) |
f3af020b | 90 | { |
3ef28e83 DW |
91 | /* |
92 | * In the !blk_mq case we are only calling this to kill the | |
93 | * q_usage_counter, otherwise this increases the freeze depth | |
94 | * and waits for it to return to zero. For this reason there is | |
95 | * no blk_unfreeze_queue(), and blk_freeze_queue() is not | |
96 | * exported to drivers as the only user for unfreeze is blk_mq. | |
97 | */ | |
f3af020b TH |
98 | blk_mq_freeze_queue_start(q); |
99 | blk_mq_freeze_queue_wait(q); | |
100 | } | |
3ef28e83 DW |
101 | |
102 | void blk_mq_freeze_queue(struct request_queue *q) | |
103 | { | |
104 | /* | |
105 | * ...just an alias to keep freeze and unfreeze actions balanced | |
106 | * in the blk_mq_* namespace | |
107 | */ | |
108 | blk_freeze_queue(q); | |
109 | } | |
c761d96b | 110 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue); |
f3af020b | 111 | |
b4c6a028 | 112 | void blk_mq_unfreeze_queue(struct request_queue *q) |
320ae51f | 113 | { |
4ecd4fef | 114 | int freeze_depth; |
320ae51f | 115 | |
4ecd4fef CH |
116 | freeze_depth = atomic_dec_return(&q->mq_freeze_depth); |
117 | WARN_ON_ONCE(freeze_depth < 0); | |
118 | if (!freeze_depth) { | |
3ef28e83 | 119 | percpu_ref_reinit(&q->q_usage_counter); |
320ae51f | 120 | wake_up_all(&q->mq_freeze_wq); |
add703fd | 121 | } |
320ae51f | 122 | } |
b4c6a028 | 123 | EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue); |
320ae51f | 124 | |
6a83e74d BVA |
125 | /** |
126 | * blk_mq_quiesce_queue() - wait until all ongoing queue_rq calls have finished | |
127 | * @q: request queue. | |
128 | * | |
129 | * Note: this function does not prevent that the struct request end_io() | |
130 | * callback function is invoked. Additionally, it is not prevented that | |
131 | * new queue_rq() calls occur unless the queue has been stopped first. | |
132 | */ | |
133 | void blk_mq_quiesce_queue(struct request_queue *q) | |
134 | { | |
135 | struct blk_mq_hw_ctx *hctx; | |
136 | unsigned int i; | |
137 | bool rcu = false; | |
138 | ||
139 | blk_mq_stop_hw_queues(q); | |
140 | ||
141 | queue_for_each_hw_ctx(q, hctx, i) { | |
142 | if (hctx->flags & BLK_MQ_F_BLOCKING) | |
143 | synchronize_srcu(&hctx->queue_rq_srcu); | |
144 | else | |
145 | rcu = true; | |
146 | } | |
147 | if (rcu) | |
148 | synchronize_rcu(); | |
149 | } | |
150 | EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue); | |
151 | ||
aed3ea94 JA |
152 | void blk_mq_wake_waiters(struct request_queue *q) |
153 | { | |
154 | struct blk_mq_hw_ctx *hctx; | |
155 | unsigned int i; | |
156 | ||
157 | queue_for_each_hw_ctx(q, hctx, i) | |
158 | if (blk_mq_hw_queue_mapped(hctx)) | |
159 | blk_mq_tag_wakeup_all(hctx->tags, true); | |
3fd5940c KB |
160 | |
161 | /* | |
162 | * If we are called because the queue has now been marked as | |
163 | * dying, we need to ensure that processes currently waiting on | |
164 | * the queue are notified as well. | |
165 | */ | |
166 | wake_up_all(&q->mq_freeze_wq); | |
aed3ea94 JA |
167 | } |
168 | ||
320ae51f JA |
169 | bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx) |
170 | { | |
171 | return blk_mq_has_free_tags(hctx->tags); | |
172 | } | |
173 | EXPORT_SYMBOL(blk_mq_can_queue); | |
174 | ||
2c3ad667 JA |
175 | void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, |
176 | struct request *rq, unsigned int op) | |
320ae51f | 177 | { |
af76e555 CH |
178 | INIT_LIST_HEAD(&rq->queuelist); |
179 | /* csd/requeue_work/fifo_time is initialized before use */ | |
180 | rq->q = q; | |
320ae51f | 181 | rq->mq_ctx = ctx; |
ef295ecf | 182 | rq->cmd_flags = op; |
e8064021 CH |
183 | if (blk_queue_io_stat(q)) |
184 | rq->rq_flags |= RQF_IO_STAT; | |
af76e555 CH |
185 | /* do not touch atomic flags, it needs atomic ops against the timer */ |
186 | rq->cpu = -1; | |
af76e555 CH |
187 | INIT_HLIST_NODE(&rq->hash); |
188 | RB_CLEAR_NODE(&rq->rb_node); | |
af76e555 CH |
189 | rq->rq_disk = NULL; |
190 | rq->part = NULL; | |
3ee32372 | 191 | rq->start_time = jiffies; |
af76e555 CH |
192 | #ifdef CONFIG_BLK_CGROUP |
193 | rq->rl = NULL; | |
0fec08b4 | 194 | set_start_time_ns(rq); |
af76e555 CH |
195 | rq->io_start_time_ns = 0; |
196 | #endif | |
197 | rq->nr_phys_segments = 0; | |
198 | #if defined(CONFIG_BLK_DEV_INTEGRITY) | |
199 | rq->nr_integrity_segments = 0; | |
200 | #endif | |
af76e555 CH |
201 | rq->special = NULL; |
202 | /* tag was already set */ | |
203 | rq->errors = 0; | |
af76e555 | 204 | rq->extra_len = 0; |
af76e555 | 205 | |
af76e555 | 206 | INIT_LIST_HEAD(&rq->timeout_list); |
f6be4fb4 JA |
207 | rq->timeout = 0; |
208 | ||
af76e555 CH |
209 | rq->end_io = NULL; |
210 | rq->end_io_data = NULL; | |
211 | rq->next_rq = NULL; | |
212 | ||
ef295ecf | 213 | ctx->rq_dispatched[op_is_sync(op)]++; |
320ae51f | 214 | } |
2c3ad667 | 215 | EXPORT_SYMBOL_GPL(blk_mq_rq_ctx_init); |
320ae51f | 216 | |
2c3ad667 JA |
217 | struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data, |
218 | unsigned int op) | |
5dee8577 CH |
219 | { |
220 | struct request *rq; | |
221 | unsigned int tag; | |
222 | ||
cb96a42c | 223 | tag = blk_mq_get_tag(data); |
5dee8577 | 224 | if (tag != BLK_MQ_TAG_FAIL) { |
bd166ef1 JA |
225 | struct blk_mq_tags *tags = blk_mq_tags_from_data(data); |
226 | ||
227 | rq = tags->static_rqs[tag]; | |
5dee8577 | 228 | |
bd166ef1 JA |
229 | if (data->flags & BLK_MQ_REQ_INTERNAL) { |
230 | rq->tag = -1; | |
231 | rq->internal_tag = tag; | |
232 | } else { | |
200e86b3 JA |
233 | if (blk_mq_tag_busy(data->hctx)) { |
234 | rq->rq_flags = RQF_MQ_INFLIGHT; | |
235 | atomic_inc(&data->hctx->nr_active); | |
236 | } | |
bd166ef1 JA |
237 | rq->tag = tag; |
238 | rq->internal_tag = -1; | |
239 | } | |
240 | ||
ef295ecf | 241 | blk_mq_rq_ctx_init(data->q, data->ctx, rq, op); |
5dee8577 CH |
242 | return rq; |
243 | } | |
244 | ||
245 | return NULL; | |
246 | } | |
2c3ad667 | 247 | EXPORT_SYMBOL_GPL(__blk_mq_alloc_request); |
5dee8577 | 248 | |
6f3b0e8b CH |
249 | struct request *blk_mq_alloc_request(struct request_queue *q, int rw, |
250 | unsigned int flags) | |
320ae51f | 251 | { |
5a797e00 | 252 | struct blk_mq_alloc_data alloc_data = { .flags = flags }; |
bd166ef1 | 253 | struct request *rq; |
a492f075 | 254 | int ret; |
320ae51f | 255 | |
6f3b0e8b | 256 | ret = blk_queue_enter(q, flags & BLK_MQ_REQ_NOWAIT); |
a492f075 JL |
257 | if (ret) |
258 | return ERR_PTR(ret); | |
320ae51f | 259 | |
bd166ef1 | 260 | rq = blk_mq_sched_get_request(q, NULL, rw, &alloc_data); |
841bac2c | 261 | |
bd166ef1 JA |
262 | blk_mq_put_ctx(alloc_data.ctx); |
263 | blk_queue_exit(q); | |
264 | ||
265 | if (!rq) | |
a492f075 | 266 | return ERR_PTR(-EWOULDBLOCK); |
0c4de0f3 CH |
267 | |
268 | rq->__data_len = 0; | |
269 | rq->__sector = (sector_t) -1; | |
270 | rq->bio = rq->biotail = NULL; | |
320ae51f JA |
271 | return rq; |
272 | } | |
4bb659b1 | 273 | EXPORT_SYMBOL(blk_mq_alloc_request); |
320ae51f | 274 | |
1f5bd336 ML |
275 | struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int rw, |
276 | unsigned int flags, unsigned int hctx_idx) | |
277 | { | |
278 | struct blk_mq_hw_ctx *hctx; | |
279 | struct blk_mq_ctx *ctx; | |
280 | struct request *rq; | |
281 | struct blk_mq_alloc_data alloc_data; | |
282 | int ret; | |
283 | ||
284 | /* | |
285 | * If the tag allocator sleeps we could get an allocation for a | |
286 | * different hardware context. No need to complicate the low level | |
287 | * allocator for this for the rare use case of a command tied to | |
288 | * a specific queue. | |
289 | */ | |
290 | if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT))) | |
291 | return ERR_PTR(-EINVAL); | |
292 | ||
293 | if (hctx_idx >= q->nr_hw_queues) | |
294 | return ERR_PTR(-EIO); | |
295 | ||
296 | ret = blk_queue_enter(q, true); | |
297 | if (ret) | |
298 | return ERR_PTR(ret); | |
299 | ||
c8712c6a CH |
300 | /* |
301 | * Check if the hardware context is actually mapped to anything. | |
302 | * If not tell the caller that it should skip this queue. | |
303 | */ | |
1f5bd336 | 304 | hctx = q->queue_hw_ctx[hctx_idx]; |
c8712c6a CH |
305 | if (!blk_mq_hw_queue_mapped(hctx)) { |
306 | ret = -EXDEV; | |
307 | goto out_queue_exit; | |
308 | } | |
1f5bd336 ML |
309 | ctx = __blk_mq_get_ctx(q, cpumask_first(hctx->cpumask)); |
310 | ||
311 | blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx); | |
ef295ecf | 312 | rq = __blk_mq_alloc_request(&alloc_data, rw); |
1f5bd336 | 313 | if (!rq) { |
c8712c6a CH |
314 | ret = -EWOULDBLOCK; |
315 | goto out_queue_exit; | |
1f5bd336 ML |
316 | } |
317 | ||
318 | return rq; | |
c8712c6a CH |
319 | |
320 | out_queue_exit: | |
321 | blk_queue_exit(q); | |
322 | return ERR_PTR(ret); | |
1f5bd336 ML |
323 | } |
324 | EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx); | |
325 | ||
bd166ef1 JA |
326 | void __blk_mq_finish_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, |
327 | struct request *rq) | |
320ae51f | 328 | { |
bd166ef1 | 329 | const int sched_tag = rq->internal_tag; |
320ae51f JA |
330 | struct request_queue *q = rq->q; |
331 | ||
e8064021 | 332 | if (rq->rq_flags & RQF_MQ_INFLIGHT) |
0d2602ca | 333 | atomic_dec(&hctx->nr_active); |
87760e5e JA |
334 | |
335 | wbt_done(q->rq_wb, &rq->issue_stat); | |
e8064021 | 336 | rq->rq_flags = 0; |
0d2602ca | 337 | |
af76e555 | 338 | clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); |
06426adf | 339 | clear_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags); |
bd166ef1 JA |
340 | if (rq->tag != -1) |
341 | blk_mq_put_tag(hctx, hctx->tags, ctx, rq->tag); | |
342 | if (sched_tag != -1) | |
343 | blk_mq_sched_completed_request(hctx, rq); | |
50e1dab8 | 344 | blk_mq_sched_restart_queues(hctx); |
3ef28e83 | 345 | blk_queue_exit(q); |
320ae51f JA |
346 | } |
347 | ||
bd166ef1 | 348 | static void blk_mq_finish_hctx_request(struct blk_mq_hw_ctx *hctx, |
16a3c2a7 | 349 | struct request *rq) |
320ae51f JA |
350 | { |
351 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
320ae51f JA |
352 | |
353 | ctx->rq_completed[rq_is_sync(rq)]++; | |
bd166ef1 JA |
354 | __blk_mq_finish_request(hctx, ctx, rq); |
355 | } | |
356 | ||
357 | void blk_mq_finish_request(struct request *rq) | |
358 | { | |
359 | blk_mq_finish_hctx_request(blk_mq_map_queue(rq->q, rq->mq_ctx->cpu), rq); | |
7c7f2f2b | 360 | } |
7c7f2f2b JA |
361 | |
362 | void blk_mq_free_request(struct request *rq) | |
363 | { | |
bd166ef1 | 364 | blk_mq_sched_put_request(rq); |
320ae51f | 365 | } |
1a3b595a | 366 | EXPORT_SYMBOL_GPL(blk_mq_free_request); |
320ae51f | 367 | |
c8a446ad | 368 | inline void __blk_mq_end_request(struct request *rq, int error) |
320ae51f | 369 | { |
0d11e6ac ML |
370 | blk_account_io_done(rq); |
371 | ||
91b63639 | 372 | if (rq->end_io) { |
87760e5e | 373 | wbt_done(rq->q->rq_wb, &rq->issue_stat); |
320ae51f | 374 | rq->end_io(rq, error); |
91b63639 CH |
375 | } else { |
376 | if (unlikely(blk_bidi_rq(rq))) | |
377 | blk_mq_free_request(rq->next_rq); | |
320ae51f | 378 | blk_mq_free_request(rq); |
91b63639 | 379 | } |
320ae51f | 380 | } |
c8a446ad | 381 | EXPORT_SYMBOL(__blk_mq_end_request); |
63151a44 | 382 | |
c8a446ad | 383 | void blk_mq_end_request(struct request *rq, int error) |
63151a44 CH |
384 | { |
385 | if (blk_update_request(rq, error, blk_rq_bytes(rq))) | |
386 | BUG(); | |
c8a446ad | 387 | __blk_mq_end_request(rq, error); |
63151a44 | 388 | } |
c8a446ad | 389 | EXPORT_SYMBOL(blk_mq_end_request); |
320ae51f | 390 | |
30a91cb4 | 391 | static void __blk_mq_complete_request_remote(void *data) |
320ae51f | 392 | { |
3d6efbf6 | 393 | struct request *rq = data; |
320ae51f | 394 | |
30a91cb4 | 395 | rq->q->softirq_done_fn(rq); |
320ae51f | 396 | } |
320ae51f | 397 | |
ed851860 | 398 | static void blk_mq_ipi_complete_request(struct request *rq) |
320ae51f JA |
399 | { |
400 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
38535201 | 401 | bool shared = false; |
320ae51f JA |
402 | int cpu; |
403 | ||
38535201 | 404 | if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) { |
30a91cb4 CH |
405 | rq->q->softirq_done_fn(rq); |
406 | return; | |
407 | } | |
320ae51f JA |
408 | |
409 | cpu = get_cpu(); | |
38535201 CH |
410 | if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags)) |
411 | shared = cpus_share_cache(cpu, ctx->cpu); | |
412 | ||
413 | if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) { | |
30a91cb4 | 414 | rq->csd.func = __blk_mq_complete_request_remote; |
3d6efbf6 CH |
415 | rq->csd.info = rq; |
416 | rq->csd.flags = 0; | |
c46fff2a | 417 | smp_call_function_single_async(ctx->cpu, &rq->csd); |
3d6efbf6 | 418 | } else { |
30a91cb4 | 419 | rq->q->softirq_done_fn(rq); |
3d6efbf6 | 420 | } |
320ae51f JA |
421 | put_cpu(); |
422 | } | |
30a91cb4 | 423 | |
cf43e6be JA |
424 | static void blk_mq_stat_add(struct request *rq) |
425 | { | |
426 | if (rq->rq_flags & RQF_STATS) { | |
427 | /* | |
428 | * We could rq->mq_ctx here, but there's less of a risk | |
429 | * of races if we have the completion event add the stats | |
430 | * to the local software queue. | |
431 | */ | |
432 | struct blk_mq_ctx *ctx; | |
433 | ||
434 | ctx = __blk_mq_get_ctx(rq->q, raw_smp_processor_id()); | |
435 | blk_stat_add(&ctx->stat[rq_data_dir(rq)], rq); | |
436 | } | |
437 | } | |
438 | ||
1fa8cc52 | 439 | static void __blk_mq_complete_request(struct request *rq) |
ed851860 JA |
440 | { |
441 | struct request_queue *q = rq->q; | |
442 | ||
cf43e6be JA |
443 | blk_mq_stat_add(rq); |
444 | ||
ed851860 | 445 | if (!q->softirq_done_fn) |
c8a446ad | 446 | blk_mq_end_request(rq, rq->errors); |
ed851860 JA |
447 | else |
448 | blk_mq_ipi_complete_request(rq); | |
449 | } | |
450 | ||
30a91cb4 CH |
451 | /** |
452 | * blk_mq_complete_request - end I/O on a request | |
453 | * @rq: the request being processed | |
454 | * | |
455 | * Description: | |
456 | * Ends all I/O on a request. It does not handle partial completions. | |
457 | * The actual completion happens out-of-order, through a IPI handler. | |
458 | **/ | |
f4829a9b | 459 | void blk_mq_complete_request(struct request *rq, int error) |
30a91cb4 | 460 | { |
95f09684 JA |
461 | struct request_queue *q = rq->q; |
462 | ||
463 | if (unlikely(blk_should_fake_timeout(q))) | |
30a91cb4 | 464 | return; |
f4829a9b CH |
465 | if (!blk_mark_rq_complete(rq)) { |
466 | rq->errors = error; | |
ed851860 | 467 | __blk_mq_complete_request(rq); |
f4829a9b | 468 | } |
30a91cb4 CH |
469 | } |
470 | EXPORT_SYMBOL(blk_mq_complete_request); | |
320ae51f | 471 | |
973c0191 KB |
472 | int blk_mq_request_started(struct request *rq) |
473 | { | |
474 | return test_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
475 | } | |
476 | EXPORT_SYMBOL_GPL(blk_mq_request_started); | |
477 | ||
e2490073 | 478 | void blk_mq_start_request(struct request *rq) |
320ae51f JA |
479 | { |
480 | struct request_queue *q = rq->q; | |
481 | ||
bd166ef1 JA |
482 | blk_mq_sched_started_request(rq); |
483 | ||
320ae51f JA |
484 | trace_block_rq_issue(q, rq); |
485 | ||
cf43e6be JA |
486 | if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags)) { |
487 | blk_stat_set_issue_time(&rq->issue_stat); | |
488 | rq->rq_flags |= RQF_STATS; | |
87760e5e | 489 | wbt_issue(q->rq_wb, &rq->issue_stat); |
cf43e6be JA |
490 | } |
491 | ||
2b8393b4 | 492 | blk_add_timer(rq); |
87ee7b11 | 493 | |
538b7534 JA |
494 | /* |
495 | * Ensure that ->deadline is visible before set the started | |
496 | * flag and clear the completed flag. | |
497 | */ | |
498 | smp_mb__before_atomic(); | |
499 | ||
87ee7b11 JA |
500 | /* |
501 | * Mark us as started and clear complete. Complete might have been | |
502 | * set if requeue raced with timeout, which then marked it as | |
503 | * complete. So be sure to clear complete again when we start | |
504 | * the request, otherwise we'll ignore the completion event. | |
505 | */ | |
4b570521 JA |
506 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) |
507 | set_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
508 | if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) | |
509 | clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); | |
49f5baa5 CH |
510 | |
511 | if (q->dma_drain_size && blk_rq_bytes(rq)) { | |
512 | /* | |
513 | * Make sure space for the drain appears. We know we can do | |
514 | * this because max_hw_segments has been adjusted to be one | |
515 | * fewer than the device can handle. | |
516 | */ | |
517 | rq->nr_phys_segments++; | |
518 | } | |
320ae51f | 519 | } |
e2490073 | 520 | EXPORT_SYMBOL(blk_mq_start_request); |
320ae51f | 521 | |
ed0791b2 | 522 | static void __blk_mq_requeue_request(struct request *rq) |
320ae51f JA |
523 | { |
524 | struct request_queue *q = rq->q; | |
525 | ||
526 | trace_block_rq_requeue(q, rq); | |
87760e5e | 527 | wbt_requeue(q->rq_wb, &rq->issue_stat); |
bd166ef1 | 528 | blk_mq_sched_requeue_request(rq); |
49f5baa5 | 529 | |
e2490073 CH |
530 | if (test_and_clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) { |
531 | if (q->dma_drain_size && blk_rq_bytes(rq)) | |
532 | rq->nr_phys_segments--; | |
533 | } | |
320ae51f JA |
534 | } |
535 | ||
2b053aca | 536 | void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list) |
ed0791b2 | 537 | { |
ed0791b2 | 538 | __blk_mq_requeue_request(rq); |
ed0791b2 | 539 | |
ed0791b2 | 540 | BUG_ON(blk_queued_rq(rq)); |
2b053aca | 541 | blk_mq_add_to_requeue_list(rq, true, kick_requeue_list); |
ed0791b2 CH |
542 | } |
543 | EXPORT_SYMBOL(blk_mq_requeue_request); | |
544 | ||
6fca6a61 CH |
545 | static void blk_mq_requeue_work(struct work_struct *work) |
546 | { | |
547 | struct request_queue *q = | |
2849450a | 548 | container_of(work, struct request_queue, requeue_work.work); |
6fca6a61 CH |
549 | LIST_HEAD(rq_list); |
550 | struct request *rq, *next; | |
551 | unsigned long flags; | |
552 | ||
553 | spin_lock_irqsave(&q->requeue_lock, flags); | |
554 | list_splice_init(&q->requeue_list, &rq_list); | |
555 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
556 | ||
557 | list_for_each_entry_safe(rq, next, &rq_list, queuelist) { | |
e8064021 | 558 | if (!(rq->rq_flags & RQF_SOFTBARRIER)) |
6fca6a61 CH |
559 | continue; |
560 | ||
e8064021 | 561 | rq->rq_flags &= ~RQF_SOFTBARRIER; |
6fca6a61 | 562 | list_del_init(&rq->queuelist); |
bd6737f1 | 563 | blk_mq_sched_insert_request(rq, true, false, false, true); |
6fca6a61 CH |
564 | } |
565 | ||
566 | while (!list_empty(&rq_list)) { | |
567 | rq = list_entry(rq_list.next, struct request, queuelist); | |
568 | list_del_init(&rq->queuelist); | |
bd6737f1 | 569 | blk_mq_sched_insert_request(rq, false, false, false, true); |
6fca6a61 CH |
570 | } |
571 | ||
52d7f1b5 | 572 | blk_mq_run_hw_queues(q, false); |
6fca6a61 CH |
573 | } |
574 | ||
2b053aca BVA |
575 | void blk_mq_add_to_requeue_list(struct request *rq, bool at_head, |
576 | bool kick_requeue_list) | |
6fca6a61 CH |
577 | { |
578 | struct request_queue *q = rq->q; | |
579 | unsigned long flags; | |
580 | ||
581 | /* | |
582 | * We abuse this flag that is otherwise used by the I/O scheduler to | |
583 | * request head insertation from the workqueue. | |
584 | */ | |
e8064021 | 585 | BUG_ON(rq->rq_flags & RQF_SOFTBARRIER); |
6fca6a61 CH |
586 | |
587 | spin_lock_irqsave(&q->requeue_lock, flags); | |
588 | if (at_head) { | |
e8064021 | 589 | rq->rq_flags |= RQF_SOFTBARRIER; |
6fca6a61 CH |
590 | list_add(&rq->queuelist, &q->requeue_list); |
591 | } else { | |
592 | list_add_tail(&rq->queuelist, &q->requeue_list); | |
593 | } | |
594 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
2b053aca BVA |
595 | |
596 | if (kick_requeue_list) | |
597 | blk_mq_kick_requeue_list(q); | |
6fca6a61 CH |
598 | } |
599 | EXPORT_SYMBOL(blk_mq_add_to_requeue_list); | |
600 | ||
601 | void blk_mq_kick_requeue_list(struct request_queue *q) | |
602 | { | |
2849450a | 603 | kblockd_schedule_delayed_work(&q->requeue_work, 0); |
6fca6a61 CH |
604 | } |
605 | EXPORT_SYMBOL(blk_mq_kick_requeue_list); | |
606 | ||
2849450a MS |
607 | void blk_mq_delay_kick_requeue_list(struct request_queue *q, |
608 | unsigned long msecs) | |
609 | { | |
610 | kblockd_schedule_delayed_work(&q->requeue_work, | |
611 | msecs_to_jiffies(msecs)); | |
612 | } | |
613 | EXPORT_SYMBOL(blk_mq_delay_kick_requeue_list); | |
614 | ||
1885b24d JA |
615 | void blk_mq_abort_requeue_list(struct request_queue *q) |
616 | { | |
617 | unsigned long flags; | |
618 | LIST_HEAD(rq_list); | |
619 | ||
620 | spin_lock_irqsave(&q->requeue_lock, flags); | |
621 | list_splice_init(&q->requeue_list, &rq_list); | |
622 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
623 | ||
624 | while (!list_empty(&rq_list)) { | |
625 | struct request *rq; | |
626 | ||
627 | rq = list_first_entry(&rq_list, struct request, queuelist); | |
628 | list_del_init(&rq->queuelist); | |
629 | rq->errors = -EIO; | |
630 | blk_mq_end_request(rq, rq->errors); | |
631 | } | |
632 | } | |
633 | EXPORT_SYMBOL(blk_mq_abort_requeue_list); | |
634 | ||
0e62f51f JA |
635 | struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag) |
636 | { | |
88c7b2b7 JA |
637 | if (tag < tags->nr_tags) { |
638 | prefetch(tags->rqs[tag]); | |
4ee86bab | 639 | return tags->rqs[tag]; |
88c7b2b7 | 640 | } |
4ee86bab HR |
641 | |
642 | return NULL; | |
24d2f903 CH |
643 | } |
644 | EXPORT_SYMBOL(blk_mq_tag_to_rq); | |
645 | ||
320ae51f | 646 | struct blk_mq_timeout_data { |
46f92d42 CH |
647 | unsigned long next; |
648 | unsigned int next_set; | |
320ae51f JA |
649 | }; |
650 | ||
90415837 | 651 | void blk_mq_rq_timed_out(struct request *req, bool reserved) |
320ae51f | 652 | { |
f8a5b122 | 653 | const struct blk_mq_ops *ops = req->q->mq_ops; |
46f92d42 | 654 | enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER; |
87ee7b11 JA |
655 | |
656 | /* | |
657 | * We know that complete is set at this point. If STARTED isn't set | |
658 | * anymore, then the request isn't active and the "timeout" should | |
659 | * just be ignored. This can happen due to the bitflag ordering. | |
660 | * Timeout first checks if STARTED is set, and if it is, assumes | |
661 | * the request is active. But if we race with completion, then | |
662 | * we both flags will get cleared. So check here again, and ignore | |
663 | * a timeout event with a request that isn't active. | |
664 | */ | |
46f92d42 CH |
665 | if (!test_bit(REQ_ATOM_STARTED, &req->atomic_flags)) |
666 | return; | |
87ee7b11 | 667 | |
46f92d42 | 668 | if (ops->timeout) |
0152fb6b | 669 | ret = ops->timeout(req, reserved); |
46f92d42 CH |
670 | |
671 | switch (ret) { | |
672 | case BLK_EH_HANDLED: | |
673 | __blk_mq_complete_request(req); | |
674 | break; | |
675 | case BLK_EH_RESET_TIMER: | |
676 | blk_add_timer(req); | |
677 | blk_clear_rq_complete(req); | |
678 | break; | |
679 | case BLK_EH_NOT_HANDLED: | |
680 | break; | |
681 | default: | |
682 | printk(KERN_ERR "block: bad eh return: %d\n", ret); | |
683 | break; | |
684 | } | |
87ee7b11 | 685 | } |
5b3f25fc | 686 | |
81481eb4 CH |
687 | static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx, |
688 | struct request *rq, void *priv, bool reserved) | |
689 | { | |
690 | struct blk_mq_timeout_data *data = priv; | |
87ee7b11 | 691 | |
eb130dbf KB |
692 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) { |
693 | /* | |
694 | * If a request wasn't started before the queue was | |
695 | * marked dying, kill it here or it'll go unnoticed. | |
696 | */ | |
a59e0f57 KB |
697 | if (unlikely(blk_queue_dying(rq->q))) { |
698 | rq->errors = -EIO; | |
699 | blk_mq_end_request(rq, rq->errors); | |
700 | } | |
46f92d42 | 701 | return; |
eb130dbf | 702 | } |
87ee7b11 | 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 | |
732 | * blk_mq_freeze_queue_start, and the moment the last request is | |
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 | ||
bd166ef1 JA |
850 | if (rq->tag != -1) { |
851 | done: | |
852 | if (hctx) | |
853 | *hctx = data.hctx; | |
854 | return true; | |
855 | } | |
856 | ||
857 | rq->tag = blk_mq_get_tag(&data); | |
858 | if (rq->tag >= 0) { | |
200e86b3 JA |
859 | if (blk_mq_tag_busy(data.hctx)) { |
860 | rq->rq_flags |= RQF_MQ_INFLIGHT; | |
861 | atomic_inc(&data.hctx->nr_active); | |
862 | } | |
bd166ef1 JA |
863 | data.hctx->tags->rqs[rq->tag] = rq; |
864 | goto done; | |
865 | } | |
866 | ||
867 | return false; | |
868 | } | |
869 | ||
99cf1dc5 JA |
870 | static void blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx, |
871 | struct request *rq) | |
872 | { | |
873 | if (rq->tag == -1 || rq->internal_tag == -1) | |
874 | return; | |
875 | ||
876 | blk_mq_put_tag(hctx, hctx->tags, rq->mq_ctx, rq->tag); | |
877 | rq->tag = -1; | |
878 | ||
879 | if (rq->rq_flags & RQF_MQ_INFLIGHT) { | |
880 | rq->rq_flags &= ~RQF_MQ_INFLIGHT; | |
881 | atomic_dec(&hctx->nr_active); | |
882 | } | |
883 | } | |
884 | ||
bd166ef1 JA |
885 | /* |
886 | * If we fail getting a driver tag because all the driver tags are already | |
887 | * assigned and on the dispatch list, BUT the first entry does not have a | |
888 | * tag, then we could deadlock. For that case, move entries with assigned | |
889 | * driver tags to the front, leaving the set of tagged requests in the | |
890 | * same order, and the untagged set in the same order. | |
891 | */ | |
892 | static bool reorder_tags_to_front(struct list_head *list) | |
893 | { | |
894 | struct request *rq, *tmp, *first = NULL; | |
895 | ||
896 | list_for_each_entry_safe_reverse(rq, tmp, list, queuelist) { | |
897 | if (rq == first) | |
898 | break; | |
899 | if (rq->tag != -1) { | |
900 | list_move(&rq->queuelist, list); | |
901 | if (!first) | |
902 | first = rq; | |
903 | } | |
904 | } | |
905 | ||
906 | return first != NULL; | |
907 | } | |
908 | ||
da55f2cc OS |
909 | static int blk_mq_dispatch_wake(wait_queue_t *wait, unsigned mode, int flags, |
910 | void *key) | |
911 | { | |
912 | struct blk_mq_hw_ctx *hctx; | |
913 | ||
914 | hctx = container_of(wait, struct blk_mq_hw_ctx, dispatch_wait); | |
915 | ||
916 | list_del(&wait->task_list); | |
917 | clear_bit_unlock(BLK_MQ_S_TAG_WAITING, &hctx->state); | |
918 | blk_mq_run_hw_queue(hctx, true); | |
919 | return 1; | |
920 | } | |
921 | ||
922 | static bool blk_mq_dispatch_wait_add(struct blk_mq_hw_ctx *hctx) | |
923 | { | |
924 | struct sbq_wait_state *ws; | |
925 | ||
926 | /* | |
927 | * The TAG_WAITING bit serves as a lock protecting hctx->dispatch_wait. | |
928 | * The thread which wins the race to grab this bit adds the hardware | |
929 | * queue to the wait queue. | |
930 | */ | |
931 | if (test_bit(BLK_MQ_S_TAG_WAITING, &hctx->state) || | |
932 | test_and_set_bit_lock(BLK_MQ_S_TAG_WAITING, &hctx->state)) | |
933 | return false; | |
934 | ||
935 | init_waitqueue_func_entry(&hctx->dispatch_wait, blk_mq_dispatch_wake); | |
936 | ws = bt_wait_ptr(&hctx->tags->bitmap_tags, hctx); | |
937 | ||
938 | /* | |
939 | * As soon as this returns, it's no longer safe to fiddle with | |
940 | * hctx->dispatch_wait, since a completion can wake up the wait queue | |
941 | * and unlock the bit. | |
942 | */ | |
943 | add_wait_queue(&ws->wait, &hctx->dispatch_wait); | |
944 | return true; | |
945 | } | |
946 | ||
f04c3df3 | 947 | bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list) |
320ae51f JA |
948 | { |
949 | struct request_queue *q = hctx->queue; | |
320ae51f | 950 | struct request *rq; |
74c45052 JA |
951 | LIST_HEAD(driver_list); |
952 | struct list_head *dptr; | |
f04c3df3 | 953 | int queued, ret = BLK_MQ_RQ_QUEUE_OK; |
320ae51f | 954 | |
74c45052 JA |
955 | /* |
956 | * Start off with dptr being NULL, so we start the first request | |
957 | * immediately, even if we have more pending. | |
958 | */ | |
959 | dptr = NULL; | |
960 | ||
320ae51f JA |
961 | /* |
962 | * Now process all the entries, sending them to the driver. | |
963 | */ | |
1429d7c9 | 964 | queued = 0; |
f04c3df3 | 965 | while (!list_empty(list)) { |
74c45052 | 966 | struct blk_mq_queue_data bd; |
320ae51f | 967 | |
f04c3df3 | 968 | rq = list_first_entry(list, struct request, queuelist); |
bd166ef1 JA |
969 | if (!blk_mq_get_driver_tag(rq, &hctx, false)) { |
970 | if (!queued && reorder_tags_to_front(list)) | |
971 | continue; | |
3c782d67 JA |
972 | |
973 | /* | |
da55f2cc OS |
974 | * The initial allocation attempt failed, so we need to |
975 | * rerun the hardware queue when a tag is freed. | |
3c782d67 | 976 | */ |
da55f2cc OS |
977 | if (blk_mq_dispatch_wait_add(hctx)) { |
978 | /* | |
979 | * It's possible that a tag was freed in the | |
980 | * window between the allocation failure and | |
981 | * adding the hardware queue to the wait queue. | |
982 | */ | |
983 | if (!blk_mq_get_driver_tag(rq, &hctx, false)) | |
984 | break; | |
985 | } else { | |
3c782d67 | 986 | break; |
da55f2cc | 987 | } |
bd166ef1 | 988 | } |
da55f2cc | 989 | |
320ae51f | 990 | list_del_init(&rq->queuelist); |
320ae51f | 991 | |
74c45052 JA |
992 | bd.rq = rq; |
993 | bd.list = dptr; | |
f04c3df3 | 994 | bd.last = list_empty(list); |
74c45052 JA |
995 | |
996 | ret = q->mq_ops->queue_rq(hctx, &bd); | |
320ae51f JA |
997 | switch (ret) { |
998 | case BLK_MQ_RQ_QUEUE_OK: | |
999 | queued++; | |
52b9c330 | 1000 | break; |
320ae51f | 1001 | case BLK_MQ_RQ_QUEUE_BUSY: |
99cf1dc5 | 1002 | blk_mq_put_driver_tag(hctx, rq); |
f04c3df3 | 1003 | list_add(&rq->queuelist, list); |
ed0791b2 | 1004 | __blk_mq_requeue_request(rq); |
320ae51f JA |
1005 | break; |
1006 | default: | |
1007 | pr_err("blk-mq: bad return on queue: %d\n", ret); | |
320ae51f | 1008 | case BLK_MQ_RQ_QUEUE_ERROR: |
1e93b8c2 | 1009 | rq->errors = -EIO; |
c8a446ad | 1010 | blk_mq_end_request(rq, rq->errors); |
320ae51f JA |
1011 | break; |
1012 | } | |
1013 | ||
1014 | if (ret == BLK_MQ_RQ_QUEUE_BUSY) | |
1015 | break; | |
74c45052 JA |
1016 | |
1017 | /* | |
1018 | * We've done the first request. If we have more than 1 | |
1019 | * left in the list, set dptr to defer issue. | |
1020 | */ | |
f04c3df3 | 1021 | if (!dptr && list->next != list->prev) |
74c45052 | 1022 | dptr = &driver_list; |
320ae51f JA |
1023 | } |
1024 | ||
703fd1c0 | 1025 | hctx->dispatched[queued_to_index(queued)]++; |
320ae51f JA |
1026 | |
1027 | /* | |
1028 | * Any items that need requeuing? Stuff them into hctx->dispatch, | |
1029 | * that is where we will continue on next queue run. | |
1030 | */ | |
f04c3df3 | 1031 | if (!list_empty(list)) { |
320ae51f | 1032 | spin_lock(&hctx->lock); |
c13660a0 | 1033 | list_splice_init(list, &hctx->dispatch); |
320ae51f | 1034 | spin_unlock(&hctx->lock); |
f04c3df3 | 1035 | |
9ba52e58 SL |
1036 | /* |
1037 | * the queue is expected stopped with BLK_MQ_RQ_QUEUE_BUSY, but | |
1038 | * it's possible the queue is stopped and restarted again | |
1039 | * before this. Queue restart will dispatch requests. And since | |
1040 | * requests in rq_list aren't added into hctx->dispatch yet, | |
1041 | * the requests in rq_list might get lost. | |
1042 | * | |
1043 | * blk_mq_run_hw_queue() already checks the STOPPED bit | |
bd166ef1 | 1044 | * |
da55f2cc OS |
1045 | * If RESTART or TAG_WAITING is set, then let completion restart |
1046 | * the queue instead of potentially looping here. | |
bd166ef1 | 1047 | */ |
da55f2cc OS |
1048 | if (!blk_mq_sched_needs_restart(hctx) && |
1049 | !test_bit(BLK_MQ_S_TAG_WAITING, &hctx->state)) | |
bd166ef1 | 1050 | blk_mq_run_hw_queue(hctx, true); |
320ae51f | 1051 | } |
f04c3df3 | 1052 | |
2aa0f21d | 1053 | return queued != 0; |
f04c3df3 JA |
1054 | } |
1055 | ||
6a83e74d BVA |
1056 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) |
1057 | { | |
1058 | int srcu_idx; | |
1059 | ||
1060 | WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) && | |
1061 | cpu_online(hctx->next_cpu)); | |
1062 | ||
1063 | if (!(hctx->flags & BLK_MQ_F_BLOCKING)) { | |
1064 | rcu_read_lock(); | |
bd166ef1 | 1065 | blk_mq_sched_dispatch_requests(hctx); |
6a83e74d BVA |
1066 | rcu_read_unlock(); |
1067 | } else { | |
1068 | srcu_idx = srcu_read_lock(&hctx->queue_rq_srcu); | |
bd166ef1 | 1069 | blk_mq_sched_dispatch_requests(hctx); |
6a83e74d BVA |
1070 | srcu_read_unlock(&hctx->queue_rq_srcu, srcu_idx); |
1071 | } | |
1072 | } | |
1073 | ||
506e931f JA |
1074 | /* |
1075 | * It'd be great if the workqueue API had a way to pass | |
1076 | * in a mask and had some smarts for more clever placement. | |
1077 | * For now we just round-robin here, switching for every | |
1078 | * BLK_MQ_CPU_WORK_BATCH queued items. | |
1079 | */ | |
1080 | static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) | |
1081 | { | |
b657d7e6 CH |
1082 | if (hctx->queue->nr_hw_queues == 1) |
1083 | return WORK_CPU_UNBOUND; | |
506e931f JA |
1084 | |
1085 | if (--hctx->next_cpu_batch <= 0) { | |
c02ebfdd | 1086 | int next_cpu; |
506e931f JA |
1087 | |
1088 | next_cpu = cpumask_next(hctx->next_cpu, hctx->cpumask); | |
1089 | if (next_cpu >= nr_cpu_ids) | |
1090 | next_cpu = cpumask_first(hctx->cpumask); | |
1091 | ||
1092 | hctx->next_cpu = next_cpu; | |
1093 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
1094 | } | |
1095 | ||
b657d7e6 | 1096 | return hctx->next_cpu; |
506e931f JA |
1097 | } |
1098 | ||
320ae51f JA |
1099 | void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
1100 | { | |
5d1b25c1 BVA |
1101 | if (unlikely(blk_mq_hctx_stopped(hctx) || |
1102 | !blk_mq_hw_queue_mapped(hctx))) | |
320ae51f JA |
1103 | return; |
1104 | ||
1b792f2f | 1105 | if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) { |
2a90d4aa PB |
1106 | int cpu = get_cpu(); |
1107 | if (cpumask_test_cpu(cpu, hctx->cpumask)) { | |
398205b8 | 1108 | __blk_mq_run_hw_queue(hctx); |
2a90d4aa | 1109 | put_cpu(); |
398205b8 PB |
1110 | return; |
1111 | } | |
e4043dcf | 1112 | |
2a90d4aa | 1113 | put_cpu(); |
e4043dcf | 1114 | } |
398205b8 | 1115 | |
27489a3c | 1116 | kblockd_schedule_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work); |
320ae51f JA |
1117 | } |
1118 | ||
b94ec296 | 1119 | void blk_mq_run_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
1120 | { |
1121 | struct blk_mq_hw_ctx *hctx; | |
1122 | int i; | |
1123 | ||
1124 | queue_for_each_hw_ctx(q, hctx, i) { | |
bd166ef1 | 1125 | if (!blk_mq_hctx_has_pending(hctx) || |
5d1b25c1 | 1126 | blk_mq_hctx_stopped(hctx)) |
320ae51f JA |
1127 | continue; |
1128 | ||
b94ec296 | 1129 | blk_mq_run_hw_queue(hctx, async); |
320ae51f JA |
1130 | } |
1131 | } | |
b94ec296 | 1132 | EXPORT_SYMBOL(blk_mq_run_hw_queues); |
320ae51f | 1133 | |
fd001443 BVA |
1134 | /** |
1135 | * blk_mq_queue_stopped() - check whether one or more hctxs have been stopped | |
1136 | * @q: request queue. | |
1137 | * | |
1138 | * The caller is responsible for serializing this function against | |
1139 | * blk_mq_{start,stop}_hw_queue(). | |
1140 | */ | |
1141 | bool blk_mq_queue_stopped(struct request_queue *q) | |
1142 | { | |
1143 | struct blk_mq_hw_ctx *hctx; | |
1144 | int i; | |
1145 | ||
1146 | queue_for_each_hw_ctx(q, hctx, i) | |
1147 | if (blk_mq_hctx_stopped(hctx)) | |
1148 | return true; | |
1149 | ||
1150 | return false; | |
1151 | } | |
1152 | EXPORT_SYMBOL(blk_mq_queue_stopped); | |
1153 | ||
320ae51f JA |
1154 | void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx) |
1155 | { | |
27489a3c | 1156 | cancel_work(&hctx->run_work); |
70f4db63 | 1157 | cancel_delayed_work(&hctx->delay_work); |
320ae51f JA |
1158 | set_bit(BLK_MQ_S_STOPPED, &hctx->state); |
1159 | } | |
1160 | EXPORT_SYMBOL(blk_mq_stop_hw_queue); | |
1161 | ||
280d45f6 CH |
1162 | void blk_mq_stop_hw_queues(struct request_queue *q) |
1163 | { | |
1164 | struct blk_mq_hw_ctx *hctx; | |
1165 | int i; | |
1166 | ||
1167 | queue_for_each_hw_ctx(q, hctx, i) | |
1168 | blk_mq_stop_hw_queue(hctx); | |
1169 | } | |
1170 | EXPORT_SYMBOL(blk_mq_stop_hw_queues); | |
1171 | ||
320ae51f JA |
1172 | void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx) |
1173 | { | |
1174 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
e4043dcf | 1175 | |
0ffbce80 | 1176 | blk_mq_run_hw_queue(hctx, false); |
320ae51f JA |
1177 | } |
1178 | EXPORT_SYMBOL(blk_mq_start_hw_queue); | |
1179 | ||
2f268556 CH |
1180 | void blk_mq_start_hw_queues(struct request_queue *q) |
1181 | { | |
1182 | struct blk_mq_hw_ctx *hctx; | |
1183 | int i; | |
1184 | ||
1185 | queue_for_each_hw_ctx(q, hctx, i) | |
1186 | blk_mq_start_hw_queue(hctx); | |
1187 | } | |
1188 | EXPORT_SYMBOL(blk_mq_start_hw_queues); | |
1189 | ||
ae911c5e JA |
1190 | void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
1191 | { | |
1192 | if (!blk_mq_hctx_stopped(hctx)) | |
1193 | return; | |
1194 | ||
1195 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
1196 | blk_mq_run_hw_queue(hctx, async); | |
1197 | } | |
1198 | EXPORT_SYMBOL_GPL(blk_mq_start_stopped_hw_queue); | |
1199 | ||
1b4a3258 | 1200 | void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
1201 | { |
1202 | struct blk_mq_hw_ctx *hctx; | |
1203 | int i; | |
1204 | ||
ae911c5e JA |
1205 | queue_for_each_hw_ctx(q, hctx, i) |
1206 | blk_mq_start_stopped_hw_queue(hctx, async); | |
320ae51f JA |
1207 | } |
1208 | EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); | |
1209 | ||
70f4db63 | 1210 | static void blk_mq_run_work_fn(struct work_struct *work) |
320ae51f JA |
1211 | { |
1212 | struct blk_mq_hw_ctx *hctx; | |
1213 | ||
27489a3c | 1214 | hctx = container_of(work, struct blk_mq_hw_ctx, run_work); |
e4043dcf | 1215 | |
320ae51f JA |
1216 | __blk_mq_run_hw_queue(hctx); |
1217 | } | |
1218 | ||
70f4db63 CH |
1219 | static void blk_mq_delay_work_fn(struct work_struct *work) |
1220 | { | |
1221 | struct blk_mq_hw_ctx *hctx; | |
1222 | ||
1223 | hctx = container_of(work, struct blk_mq_hw_ctx, delay_work.work); | |
1224 | ||
1225 | if (test_and_clear_bit(BLK_MQ_S_STOPPED, &hctx->state)) | |
1226 | __blk_mq_run_hw_queue(hctx); | |
1227 | } | |
1228 | ||
1229 | void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) | |
1230 | { | |
19c66e59 ML |
1231 | if (unlikely(!blk_mq_hw_queue_mapped(hctx))) |
1232 | return; | |
70f4db63 | 1233 | |
7e79dadc | 1234 | blk_mq_stop_hw_queue(hctx); |
b657d7e6 CH |
1235 | kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx), |
1236 | &hctx->delay_work, msecs_to_jiffies(msecs)); | |
70f4db63 CH |
1237 | } |
1238 | EXPORT_SYMBOL(blk_mq_delay_queue); | |
1239 | ||
cfd0c552 | 1240 | static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx, |
cfd0c552 ML |
1241 | struct request *rq, |
1242 | bool at_head) | |
320ae51f | 1243 | { |
e57690fe JA |
1244 | struct blk_mq_ctx *ctx = rq->mq_ctx; |
1245 | ||
01b983c9 JA |
1246 | trace_block_rq_insert(hctx->queue, rq); |
1247 | ||
72a0a36e CH |
1248 | if (at_head) |
1249 | list_add(&rq->queuelist, &ctx->rq_list); | |
1250 | else | |
1251 | list_add_tail(&rq->queuelist, &ctx->rq_list); | |
cfd0c552 | 1252 | } |
4bb659b1 | 1253 | |
2c3ad667 JA |
1254 | void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, |
1255 | bool at_head) | |
cfd0c552 ML |
1256 | { |
1257 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
1258 | ||
e57690fe | 1259 | __blk_mq_insert_req_list(hctx, rq, at_head); |
320ae51f | 1260 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f JA |
1261 | } |
1262 | ||
bd166ef1 JA |
1263 | void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, |
1264 | struct list_head *list) | |
320ae51f JA |
1265 | |
1266 | { | |
320ae51f JA |
1267 | /* |
1268 | * preemption doesn't flush plug list, so it's possible ctx->cpu is | |
1269 | * offline now | |
1270 | */ | |
1271 | spin_lock(&ctx->lock); | |
1272 | while (!list_empty(list)) { | |
1273 | struct request *rq; | |
1274 | ||
1275 | rq = list_first_entry(list, struct request, queuelist); | |
e57690fe | 1276 | BUG_ON(rq->mq_ctx != ctx); |
320ae51f | 1277 | list_del_init(&rq->queuelist); |
e57690fe | 1278 | __blk_mq_insert_req_list(hctx, rq, false); |
320ae51f | 1279 | } |
cfd0c552 | 1280 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f | 1281 | spin_unlock(&ctx->lock); |
320ae51f JA |
1282 | } |
1283 | ||
1284 | static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b) | |
1285 | { | |
1286 | struct request *rqa = container_of(a, struct request, queuelist); | |
1287 | struct request *rqb = container_of(b, struct request, queuelist); | |
1288 | ||
1289 | return !(rqa->mq_ctx < rqb->mq_ctx || | |
1290 | (rqa->mq_ctx == rqb->mq_ctx && | |
1291 | blk_rq_pos(rqa) < blk_rq_pos(rqb))); | |
1292 | } | |
1293 | ||
1294 | void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) | |
1295 | { | |
1296 | struct blk_mq_ctx *this_ctx; | |
1297 | struct request_queue *this_q; | |
1298 | struct request *rq; | |
1299 | LIST_HEAD(list); | |
1300 | LIST_HEAD(ctx_list); | |
1301 | unsigned int depth; | |
1302 | ||
1303 | list_splice_init(&plug->mq_list, &list); | |
1304 | ||
1305 | list_sort(NULL, &list, plug_ctx_cmp); | |
1306 | ||
1307 | this_q = NULL; | |
1308 | this_ctx = NULL; | |
1309 | depth = 0; | |
1310 | ||
1311 | while (!list_empty(&list)) { | |
1312 | rq = list_entry_rq(list.next); | |
1313 | list_del_init(&rq->queuelist); | |
1314 | BUG_ON(!rq->q); | |
1315 | if (rq->mq_ctx != this_ctx) { | |
1316 | if (this_ctx) { | |
bd166ef1 JA |
1317 | trace_block_unplug(this_q, depth, from_schedule); |
1318 | blk_mq_sched_insert_requests(this_q, this_ctx, | |
1319 | &ctx_list, | |
1320 | from_schedule); | |
320ae51f JA |
1321 | } |
1322 | ||
1323 | this_ctx = rq->mq_ctx; | |
1324 | this_q = rq->q; | |
1325 | depth = 0; | |
1326 | } | |
1327 | ||
1328 | depth++; | |
1329 | list_add_tail(&rq->queuelist, &ctx_list); | |
1330 | } | |
1331 | ||
1332 | /* | |
1333 | * If 'this_ctx' is set, we know we have entries to complete | |
1334 | * on 'ctx_list'. Do those. | |
1335 | */ | |
1336 | if (this_ctx) { | |
bd166ef1 JA |
1337 | trace_block_unplug(this_q, depth, from_schedule); |
1338 | blk_mq_sched_insert_requests(this_q, this_ctx, &ctx_list, | |
1339 | from_schedule); | |
320ae51f JA |
1340 | } |
1341 | } | |
1342 | ||
1343 | static void blk_mq_bio_to_request(struct request *rq, struct bio *bio) | |
1344 | { | |
1345 | init_request_from_bio(rq, bio); | |
4b570521 | 1346 | |
6e85eaf3 | 1347 | blk_account_io_start(rq, true); |
320ae51f JA |
1348 | } |
1349 | ||
274a5843 JA |
1350 | static inline bool hctx_allow_merges(struct blk_mq_hw_ctx *hctx) |
1351 | { | |
1352 | return (hctx->flags & BLK_MQ_F_SHOULD_MERGE) && | |
1353 | !blk_queue_nomerges(hctx->queue); | |
1354 | } | |
1355 | ||
07068d5b JA |
1356 | static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx, |
1357 | struct blk_mq_ctx *ctx, | |
1358 | struct request *rq, struct bio *bio) | |
320ae51f | 1359 | { |
e18378a6 | 1360 | if (!hctx_allow_merges(hctx) || !bio_mergeable(bio)) { |
07068d5b JA |
1361 | blk_mq_bio_to_request(rq, bio); |
1362 | spin_lock(&ctx->lock); | |
1363 | insert_rq: | |
1364 | __blk_mq_insert_request(hctx, rq, false); | |
1365 | spin_unlock(&ctx->lock); | |
1366 | return false; | |
1367 | } else { | |
274a5843 JA |
1368 | struct request_queue *q = hctx->queue; |
1369 | ||
07068d5b JA |
1370 | spin_lock(&ctx->lock); |
1371 | if (!blk_mq_attempt_merge(q, ctx, bio)) { | |
1372 | blk_mq_bio_to_request(rq, bio); | |
1373 | goto insert_rq; | |
1374 | } | |
320ae51f | 1375 | |
07068d5b | 1376 | spin_unlock(&ctx->lock); |
bd166ef1 | 1377 | __blk_mq_finish_request(hctx, ctx, rq); |
07068d5b | 1378 | return true; |
14ec77f3 | 1379 | } |
07068d5b | 1380 | } |
14ec77f3 | 1381 | |
fd2d3326 JA |
1382 | static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq) |
1383 | { | |
bd166ef1 JA |
1384 | if (rq->tag != -1) |
1385 | return blk_tag_to_qc_t(rq->tag, hctx->queue_num, false); | |
1386 | ||
1387 | return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true); | |
fd2d3326 JA |
1388 | } |
1389 | ||
066a4a73 | 1390 | static void blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie) |
f984df1f | 1391 | { |
f984df1f | 1392 | struct request_queue *q = rq->q; |
f984df1f SL |
1393 | struct blk_mq_queue_data bd = { |
1394 | .rq = rq, | |
1395 | .list = NULL, | |
1396 | .last = 1 | |
1397 | }; | |
bd166ef1 JA |
1398 | struct blk_mq_hw_ctx *hctx; |
1399 | blk_qc_t new_cookie; | |
1400 | int ret; | |
f984df1f | 1401 | |
bd166ef1 | 1402 | if (q->elevator) |
2253efc8 BVA |
1403 | goto insert; |
1404 | ||
bd166ef1 JA |
1405 | if (!blk_mq_get_driver_tag(rq, &hctx, false)) |
1406 | goto insert; | |
1407 | ||
1408 | new_cookie = request_to_qc_t(hctx, rq); | |
1409 | ||
f984df1f SL |
1410 | /* |
1411 | * For OK queue, we are done. For error, kill it. Any other | |
1412 | * error (busy), just add it to our list as we previously | |
1413 | * would have done | |
1414 | */ | |
1415 | ret = q->mq_ops->queue_rq(hctx, &bd); | |
7b371636 JA |
1416 | if (ret == BLK_MQ_RQ_QUEUE_OK) { |
1417 | *cookie = new_cookie; | |
2253efc8 | 1418 | return; |
7b371636 | 1419 | } |
f984df1f | 1420 | |
7b371636 JA |
1421 | __blk_mq_requeue_request(rq); |
1422 | ||
1423 | if (ret == BLK_MQ_RQ_QUEUE_ERROR) { | |
1424 | *cookie = BLK_QC_T_NONE; | |
1425 | rq->errors = -EIO; | |
1426 | blk_mq_end_request(rq, rq->errors); | |
2253efc8 | 1427 | return; |
f984df1f | 1428 | } |
7b371636 | 1429 | |
2253efc8 | 1430 | insert: |
bd6737f1 | 1431 | blk_mq_sched_insert_request(rq, false, true, true, false); |
f984df1f SL |
1432 | } |
1433 | ||
07068d5b JA |
1434 | /* |
1435 | * Multiple hardware queue variant. This will not use per-process plugs, | |
1436 | * but will attempt to bypass the hctx queueing if we can go straight to | |
1437 | * hardware for SYNC IO. | |
1438 | */ | |
dece1635 | 1439 | static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) |
07068d5b | 1440 | { |
ef295ecf | 1441 | const int is_sync = op_is_sync(bio->bi_opf); |
f73f44eb | 1442 | const int is_flush_fua = op_is_flush(bio->bi_opf); |
5a797e00 | 1443 | struct blk_mq_alloc_data data = { .flags = 0 }; |
07068d5b | 1444 | struct request *rq; |
6a83e74d | 1445 | unsigned int request_count = 0, srcu_idx; |
f984df1f | 1446 | struct blk_plug *plug; |
5b3f341f | 1447 | struct request *same_queue_rq = NULL; |
7b371636 | 1448 | blk_qc_t cookie; |
87760e5e | 1449 | unsigned int wb_acct; |
07068d5b JA |
1450 | |
1451 | blk_queue_bounce(q, &bio); | |
1452 | ||
1453 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
4246a0b6 | 1454 | bio_io_error(bio); |
dece1635 | 1455 | return BLK_QC_T_NONE; |
07068d5b JA |
1456 | } |
1457 | ||
54efd50b KO |
1458 | blk_queue_split(q, &bio, q->bio_split); |
1459 | ||
87c279e6 OS |
1460 | if (!is_flush_fua && !blk_queue_nomerges(q) && |
1461 | blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq)) | |
1462 | return BLK_QC_T_NONE; | |
f984df1f | 1463 | |
bd166ef1 JA |
1464 | if (blk_mq_sched_bio_merge(q, bio)) |
1465 | return BLK_QC_T_NONE; | |
1466 | ||
87760e5e JA |
1467 | wb_acct = wbt_wait(q->rq_wb, bio, NULL); |
1468 | ||
bd166ef1 JA |
1469 | trace_block_getrq(q, bio, bio->bi_opf); |
1470 | ||
1471 | rq = blk_mq_sched_get_request(q, bio, bio->bi_opf, &data); | |
87760e5e JA |
1472 | if (unlikely(!rq)) { |
1473 | __wbt_done(q->rq_wb, wb_acct); | |
dece1635 | 1474 | return BLK_QC_T_NONE; |
87760e5e JA |
1475 | } |
1476 | ||
1477 | wbt_track(&rq->issue_stat, wb_acct); | |
07068d5b | 1478 | |
fd2d3326 | 1479 | cookie = request_to_qc_t(data.hctx, rq); |
07068d5b JA |
1480 | |
1481 | if (unlikely(is_flush_fua)) { | |
0c2a6fe4 JA |
1482 | if (q->elevator) |
1483 | goto elv_insert; | |
07068d5b JA |
1484 | blk_mq_bio_to_request(rq, bio); |
1485 | blk_insert_flush(rq); | |
0c2a6fe4 | 1486 | goto run_queue; |
07068d5b JA |
1487 | } |
1488 | ||
f984df1f | 1489 | plug = current->plug; |
e167dfb5 JA |
1490 | /* |
1491 | * If the driver supports defer issued based on 'last', then | |
1492 | * queue it up like normal since we can potentially save some | |
1493 | * CPU this way. | |
1494 | */ | |
f984df1f SL |
1495 | if (((plug && !blk_queue_nomerges(q)) || is_sync) && |
1496 | !(data.hctx->flags & BLK_MQ_F_DEFER_ISSUE)) { | |
1497 | struct request *old_rq = NULL; | |
07068d5b JA |
1498 | |
1499 | blk_mq_bio_to_request(rq, bio); | |
07068d5b JA |
1500 | |
1501 | /* | |
6a83e74d | 1502 | * We do limited plugging. If the bio can be merged, do that. |
f984df1f SL |
1503 | * Otherwise the existing request in the plug list will be |
1504 | * issued. So the plug list will have one request at most | |
07068d5b | 1505 | */ |
f984df1f | 1506 | if (plug) { |
5b3f341f SL |
1507 | /* |
1508 | * The plug list might get flushed before this. If that | |
b094f89c JA |
1509 | * happens, same_queue_rq is invalid and plug list is |
1510 | * empty | |
1511 | */ | |
5b3f341f SL |
1512 | if (same_queue_rq && !list_empty(&plug->mq_list)) { |
1513 | old_rq = same_queue_rq; | |
f984df1f | 1514 | list_del_init(&old_rq->queuelist); |
07068d5b | 1515 | } |
f984df1f SL |
1516 | list_add_tail(&rq->queuelist, &plug->mq_list); |
1517 | } else /* is_sync */ | |
1518 | old_rq = rq; | |
1519 | blk_mq_put_ctx(data.ctx); | |
1520 | if (!old_rq) | |
7b371636 | 1521 | goto done; |
6a83e74d BVA |
1522 | |
1523 | if (!(data.hctx->flags & BLK_MQ_F_BLOCKING)) { | |
1524 | rcu_read_lock(); | |
066a4a73 | 1525 | blk_mq_try_issue_directly(old_rq, &cookie); |
6a83e74d BVA |
1526 | rcu_read_unlock(); |
1527 | } else { | |
1528 | srcu_idx = srcu_read_lock(&data.hctx->queue_rq_srcu); | |
066a4a73 | 1529 | blk_mq_try_issue_directly(old_rq, &cookie); |
6a83e74d BVA |
1530 | srcu_read_unlock(&data.hctx->queue_rq_srcu, srcu_idx); |
1531 | } | |
7b371636 | 1532 | goto done; |
07068d5b JA |
1533 | } |
1534 | ||
bd166ef1 | 1535 | if (q->elevator) { |
0c2a6fe4 | 1536 | elv_insert: |
bd166ef1 JA |
1537 | blk_mq_put_ctx(data.ctx); |
1538 | blk_mq_bio_to_request(rq, bio); | |
0abad774 | 1539 | blk_mq_sched_insert_request(rq, false, true, |
bd6737f1 | 1540 | !is_sync || is_flush_fua, true); |
bd166ef1 JA |
1541 | goto done; |
1542 | } | |
07068d5b JA |
1543 | if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { |
1544 | /* | |
1545 | * For a SYNC request, send it to the hardware immediately. For | |
1546 | * an ASYNC request, just ensure that we run it later on. The | |
1547 | * latter allows for merging opportunities and more efficient | |
1548 | * dispatching. | |
1549 | */ | |
0c2a6fe4 | 1550 | run_queue: |
07068d5b JA |
1551 | blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); |
1552 | } | |
07068d5b | 1553 | blk_mq_put_ctx(data.ctx); |
7b371636 JA |
1554 | done: |
1555 | return cookie; | |
07068d5b JA |
1556 | } |
1557 | ||
1558 | /* | |
1559 | * Single hardware queue variant. This will attempt to use any per-process | |
1560 | * plug for merging and IO deferral. | |
1561 | */ | |
dece1635 | 1562 | static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio) |
07068d5b | 1563 | { |
ef295ecf | 1564 | const int is_sync = op_is_sync(bio->bi_opf); |
f73f44eb | 1565 | const int is_flush_fua = op_is_flush(bio->bi_opf); |
e6c4438b JM |
1566 | struct blk_plug *plug; |
1567 | unsigned int request_count = 0; | |
5a797e00 | 1568 | struct blk_mq_alloc_data data = { .flags = 0 }; |
07068d5b | 1569 | struct request *rq; |
7b371636 | 1570 | blk_qc_t cookie; |
87760e5e | 1571 | unsigned int wb_acct; |
07068d5b | 1572 | |
07068d5b JA |
1573 | blk_queue_bounce(q, &bio); |
1574 | ||
1575 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
4246a0b6 | 1576 | bio_io_error(bio); |
dece1635 | 1577 | return BLK_QC_T_NONE; |
07068d5b JA |
1578 | } |
1579 | ||
54efd50b KO |
1580 | blk_queue_split(q, &bio, q->bio_split); |
1581 | ||
87c279e6 OS |
1582 | if (!is_flush_fua && !blk_queue_nomerges(q)) { |
1583 | if (blk_attempt_plug_merge(q, bio, &request_count, NULL)) | |
1584 | return BLK_QC_T_NONE; | |
1585 | } else | |
1586 | request_count = blk_plug_queued_count(q); | |
07068d5b | 1587 | |
bd166ef1 JA |
1588 | if (blk_mq_sched_bio_merge(q, bio)) |
1589 | return BLK_QC_T_NONE; | |
1590 | ||
87760e5e JA |
1591 | wb_acct = wbt_wait(q->rq_wb, bio, NULL); |
1592 | ||
bd166ef1 JA |
1593 | trace_block_getrq(q, bio, bio->bi_opf); |
1594 | ||
1595 | rq = blk_mq_sched_get_request(q, bio, bio->bi_opf, &data); | |
87760e5e JA |
1596 | if (unlikely(!rq)) { |
1597 | __wbt_done(q->rq_wb, wb_acct); | |
dece1635 | 1598 | return BLK_QC_T_NONE; |
87760e5e JA |
1599 | } |
1600 | ||
1601 | wbt_track(&rq->issue_stat, wb_acct); | |
320ae51f | 1602 | |
fd2d3326 | 1603 | cookie = request_to_qc_t(data.hctx, rq); |
320ae51f JA |
1604 | |
1605 | if (unlikely(is_flush_fua)) { | |
0c2a6fe4 JA |
1606 | if (q->elevator) |
1607 | goto elv_insert; | |
320ae51f | 1608 | blk_mq_bio_to_request(rq, bio); |
320ae51f | 1609 | blk_insert_flush(rq); |
0c2a6fe4 | 1610 | goto run_queue; |
320ae51f JA |
1611 | } |
1612 | ||
1613 | /* | |
1614 | * A task plug currently exists. Since this is completely lockless, | |
1615 | * utilize that to temporarily store requests until the task is | |
1616 | * either done or scheduled away. | |
1617 | */ | |
e6c4438b JM |
1618 | plug = current->plug; |
1619 | if (plug) { | |
600271d9 SL |
1620 | struct request *last = NULL; |
1621 | ||
e6c4438b | 1622 | blk_mq_bio_to_request(rq, bio); |
0a6219a9 ML |
1623 | |
1624 | /* | |
1625 | * @request_count may become stale because of schedule | |
1626 | * out, so check the list again. | |
1627 | */ | |
1628 | if (list_empty(&plug->mq_list)) | |
1629 | request_count = 0; | |
676d0607 | 1630 | if (!request_count) |
e6c4438b | 1631 | trace_block_plug(q); |
600271d9 SL |
1632 | else |
1633 | last = list_entry_rq(plug->mq_list.prev); | |
b094f89c JA |
1634 | |
1635 | blk_mq_put_ctx(data.ctx); | |
1636 | ||
600271d9 SL |
1637 | if (request_count >= BLK_MAX_REQUEST_COUNT || (last && |
1638 | blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE)) { | |
e6c4438b JM |
1639 | blk_flush_plug_list(plug, false); |
1640 | trace_block_plug(q); | |
320ae51f | 1641 | } |
b094f89c | 1642 | |
e6c4438b | 1643 | list_add_tail(&rq->queuelist, &plug->mq_list); |
7b371636 | 1644 | return cookie; |
320ae51f JA |
1645 | } |
1646 | ||
bd166ef1 | 1647 | if (q->elevator) { |
0c2a6fe4 | 1648 | elv_insert: |
bd166ef1 JA |
1649 | blk_mq_put_ctx(data.ctx); |
1650 | blk_mq_bio_to_request(rq, bio); | |
0abad774 | 1651 | blk_mq_sched_insert_request(rq, false, true, |
bd6737f1 | 1652 | !is_sync || is_flush_fua, true); |
bd166ef1 JA |
1653 | goto done; |
1654 | } | |
07068d5b JA |
1655 | if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { |
1656 | /* | |
1657 | * For a SYNC request, send it to the hardware immediately. For | |
1658 | * an ASYNC request, just ensure that we run it later on. The | |
1659 | * latter allows for merging opportunities and more efficient | |
1660 | * dispatching. | |
1661 | */ | |
0c2a6fe4 | 1662 | run_queue: |
07068d5b | 1663 | blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); |
320ae51f JA |
1664 | } |
1665 | ||
07068d5b | 1666 | blk_mq_put_ctx(data.ctx); |
bd166ef1 | 1667 | done: |
7b371636 | 1668 | return cookie; |
320ae51f JA |
1669 | } |
1670 | ||
cc71a6f4 JA |
1671 | void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, |
1672 | unsigned int hctx_idx) | |
95363efd | 1673 | { |
e9b267d9 | 1674 | struct page *page; |
320ae51f | 1675 | |
24d2f903 | 1676 | if (tags->rqs && set->ops->exit_request) { |
e9b267d9 | 1677 | int i; |
320ae51f | 1678 | |
24d2f903 | 1679 | for (i = 0; i < tags->nr_tags; i++) { |
2af8cbe3 JA |
1680 | struct request *rq = tags->static_rqs[i]; |
1681 | ||
1682 | if (!rq) | |
e9b267d9 | 1683 | continue; |
2af8cbe3 | 1684 | set->ops->exit_request(set->driver_data, rq, |
24d2f903 | 1685 | hctx_idx, i); |
2af8cbe3 | 1686 | tags->static_rqs[i] = NULL; |
e9b267d9 | 1687 | } |
320ae51f | 1688 | } |
320ae51f | 1689 | |
24d2f903 CH |
1690 | while (!list_empty(&tags->page_list)) { |
1691 | page = list_first_entry(&tags->page_list, struct page, lru); | |
6753471c | 1692 | list_del_init(&page->lru); |
f75782e4 CM |
1693 | /* |
1694 | * Remove kmemleak object previously allocated in | |
1695 | * blk_mq_init_rq_map(). | |
1696 | */ | |
1697 | kmemleak_free(page_address(page)); | |
320ae51f JA |
1698 | __free_pages(page, page->private); |
1699 | } | |
cc71a6f4 | 1700 | } |
320ae51f | 1701 | |
cc71a6f4 JA |
1702 | void blk_mq_free_rq_map(struct blk_mq_tags *tags) |
1703 | { | |
24d2f903 | 1704 | kfree(tags->rqs); |
cc71a6f4 | 1705 | tags->rqs = NULL; |
2af8cbe3 JA |
1706 | kfree(tags->static_rqs); |
1707 | tags->static_rqs = NULL; | |
320ae51f | 1708 | |
24d2f903 | 1709 | blk_mq_free_tags(tags); |
320ae51f JA |
1710 | } |
1711 | ||
cc71a6f4 JA |
1712 | struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, |
1713 | unsigned int hctx_idx, | |
1714 | unsigned int nr_tags, | |
1715 | unsigned int reserved_tags) | |
320ae51f | 1716 | { |
24d2f903 | 1717 | struct blk_mq_tags *tags; |
320ae51f | 1718 | |
cc71a6f4 | 1719 | tags = blk_mq_init_tags(nr_tags, reserved_tags, |
24391c0d SL |
1720 | set->numa_node, |
1721 | BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags)); | |
24d2f903 CH |
1722 | if (!tags) |
1723 | return NULL; | |
320ae51f | 1724 | |
cc71a6f4 | 1725 | tags->rqs = kzalloc_node(nr_tags * sizeof(struct request *), |
36e1f3d1 | 1726 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, |
a5164405 | 1727 | set->numa_node); |
24d2f903 CH |
1728 | if (!tags->rqs) { |
1729 | blk_mq_free_tags(tags); | |
1730 | return NULL; | |
1731 | } | |
320ae51f | 1732 | |
2af8cbe3 JA |
1733 | tags->static_rqs = kzalloc_node(nr_tags * sizeof(struct request *), |
1734 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, | |
1735 | set->numa_node); | |
1736 | if (!tags->static_rqs) { | |
1737 | kfree(tags->rqs); | |
1738 | blk_mq_free_tags(tags); | |
1739 | return NULL; | |
1740 | } | |
1741 | ||
cc71a6f4 JA |
1742 | return tags; |
1743 | } | |
1744 | ||
1745 | static size_t order_to_size(unsigned int order) | |
1746 | { | |
1747 | return (size_t)PAGE_SIZE << order; | |
1748 | } | |
1749 | ||
1750 | int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, | |
1751 | unsigned int hctx_idx, unsigned int depth) | |
1752 | { | |
1753 | unsigned int i, j, entries_per_page, max_order = 4; | |
1754 | size_t rq_size, left; | |
1755 | ||
1756 | INIT_LIST_HEAD(&tags->page_list); | |
1757 | ||
320ae51f JA |
1758 | /* |
1759 | * rq_size is the size of the request plus driver payload, rounded | |
1760 | * to the cacheline size | |
1761 | */ | |
24d2f903 | 1762 | rq_size = round_up(sizeof(struct request) + set->cmd_size, |
320ae51f | 1763 | cache_line_size()); |
cc71a6f4 | 1764 | left = rq_size * depth; |
320ae51f | 1765 | |
cc71a6f4 | 1766 | for (i = 0; i < depth; ) { |
320ae51f JA |
1767 | int this_order = max_order; |
1768 | struct page *page; | |
1769 | int to_do; | |
1770 | void *p; | |
1771 | ||
b3a834b1 | 1772 | while (this_order && left < order_to_size(this_order - 1)) |
320ae51f JA |
1773 | this_order--; |
1774 | ||
1775 | do { | |
a5164405 | 1776 | page = alloc_pages_node(set->numa_node, |
36e1f3d1 | 1777 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO, |
a5164405 | 1778 | this_order); |
320ae51f JA |
1779 | if (page) |
1780 | break; | |
1781 | if (!this_order--) | |
1782 | break; | |
1783 | if (order_to_size(this_order) < rq_size) | |
1784 | break; | |
1785 | } while (1); | |
1786 | ||
1787 | if (!page) | |
24d2f903 | 1788 | goto fail; |
320ae51f JA |
1789 | |
1790 | page->private = this_order; | |
24d2f903 | 1791 | list_add_tail(&page->lru, &tags->page_list); |
320ae51f JA |
1792 | |
1793 | p = page_address(page); | |
f75782e4 CM |
1794 | /* |
1795 | * Allow kmemleak to scan these pages as they contain pointers | |
1796 | * to additional allocations like via ops->init_request(). | |
1797 | */ | |
36e1f3d1 | 1798 | kmemleak_alloc(p, order_to_size(this_order), 1, GFP_NOIO); |
320ae51f | 1799 | entries_per_page = order_to_size(this_order) / rq_size; |
cc71a6f4 | 1800 | to_do = min(entries_per_page, depth - i); |
320ae51f JA |
1801 | left -= to_do * rq_size; |
1802 | for (j = 0; j < to_do; j++) { | |
2af8cbe3 JA |
1803 | struct request *rq = p; |
1804 | ||
1805 | tags->static_rqs[i] = rq; | |
24d2f903 CH |
1806 | if (set->ops->init_request) { |
1807 | if (set->ops->init_request(set->driver_data, | |
2af8cbe3 | 1808 | rq, hctx_idx, i, |
a5164405 | 1809 | set->numa_node)) { |
2af8cbe3 | 1810 | tags->static_rqs[i] = NULL; |
24d2f903 | 1811 | goto fail; |
a5164405 | 1812 | } |
e9b267d9 CH |
1813 | } |
1814 | ||
320ae51f JA |
1815 | p += rq_size; |
1816 | i++; | |
1817 | } | |
1818 | } | |
cc71a6f4 | 1819 | return 0; |
320ae51f | 1820 | |
24d2f903 | 1821 | fail: |
cc71a6f4 JA |
1822 | blk_mq_free_rqs(set, tags, hctx_idx); |
1823 | return -ENOMEM; | |
320ae51f JA |
1824 | } |
1825 | ||
e57690fe JA |
1826 | /* |
1827 | * 'cpu' is going away. splice any existing rq_list entries from this | |
1828 | * software queue to the hw queue dispatch list, and ensure that it | |
1829 | * gets run. | |
1830 | */ | |
9467f859 | 1831 | static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node) |
484b4061 | 1832 | { |
9467f859 | 1833 | struct blk_mq_hw_ctx *hctx; |
484b4061 JA |
1834 | struct blk_mq_ctx *ctx; |
1835 | LIST_HEAD(tmp); | |
1836 | ||
9467f859 | 1837 | hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_dead); |
e57690fe | 1838 | ctx = __blk_mq_get_ctx(hctx->queue, cpu); |
484b4061 JA |
1839 | |
1840 | spin_lock(&ctx->lock); | |
1841 | if (!list_empty(&ctx->rq_list)) { | |
1842 | list_splice_init(&ctx->rq_list, &tmp); | |
1843 | blk_mq_hctx_clear_pending(hctx, ctx); | |
1844 | } | |
1845 | spin_unlock(&ctx->lock); | |
1846 | ||
1847 | if (list_empty(&tmp)) | |
9467f859 | 1848 | return 0; |
484b4061 | 1849 | |
e57690fe JA |
1850 | spin_lock(&hctx->lock); |
1851 | list_splice_tail_init(&tmp, &hctx->dispatch); | |
1852 | spin_unlock(&hctx->lock); | |
484b4061 JA |
1853 | |
1854 | blk_mq_run_hw_queue(hctx, true); | |
9467f859 | 1855 | return 0; |
484b4061 JA |
1856 | } |
1857 | ||
9467f859 | 1858 | static void blk_mq_remove_cpuhp(struct blk_mq_hw_ctx *hctx) |
484b4061 | 1859 | { |
9467f859 TG |
1860 | cpuhp_state_remove_instance_nocalls(CPUHP_BLK_MQ_DEAD, |
1861 | &hctx->cpuhp_dead); | |
484b4061 JA |
1862 | } |
1863 | ||
c3b4afca | 1864 | /* hctx->ctxs will be freed in queue's release handler */ |
08e98fc6 ML |
1865 | static void blk_mq_exit_hctx(struct request_queue *q, |
1866 | struct blk_mq_tag_set *set, | |
1867 | struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) | |
1868 | { | |
f70ced09 ML |
1869 | unsigned flush_start_tag = set->queue_depth; |
1870 | ||
08e98fc6 ML |
1871 | blk_mq_tag_idle(hctx); |
1872 | ||
f70ced09 ML |
1873 | if (set->ops->exit_request) |
1874 | set->ops->exit_request(set->driver_data, | |
1875 | hctx->fq->flush_rq, hctx_idx, | |
1876 | flush_start_tag + hctx_idx); | |
1877 | ||
08e98fc6 ML |
1878 | if (set->ops->exit_hctx) |
1879 | set->ops->exit_hctx(hctx, hctx_idx); | |
1880 | ||
6a83e74d BVA |
1881 | if (hctx->flags & BLK_MQ_F_BLOCKING) |
1882 | cleanup_srcu_struct(&hctx->queue_rq_srcu); | |
1883 | ||
9467f859 | 1884 | blk_mq_remove_cpuhp(hctx); |
f70ced09 | 1885 | blk_free_flush_queue(hctx->fq); |
88459642 | 1886 | sbitmap_free(&hctx->ctx_map); |
08e98fc6 ML |
1887 | } |
1888 | ||
624dbe47 ML |
1889 | static void blk_mq_exit_hw_queues(struct request_queue *q, |
1890 | struct blk_mq_tag_set *set, int nr_queue) | |
1891 | { | |
1892 | struct blk_mq_hw_ctx *hctx; | |
1893 | unsigned int i; | |
1894 | ||
1895 | queue_for_each_hw_ctx(q, hctx, i) { | |
1896 | if (i == nr_queue) | |
1897 | break; | |
08e98fc6 | 1898 | blk_mq_exit_hctx(q, set, hctx, i); |
624dbe47 | 1899 | } |
624dbe47 ML |
1900 | } |
1901 | ||
1902 | static void blk_mq_free_hw_queues(struct request_queue *q, | |
1903 | struct blk_mq_tag_set *set) | |
1904 | { | |
1905 | struct blk_mq_hw_ctx *hctx; | |
1906 | unsigned int i; | |
1907 | ||
e09aae7e | 1908 | queue_for_each_hw_ctx(q, hctx, i) |
624dbe47 | 1909 | free_cpumask_var(hctx->cpumask); |
624dbe47 ML |
1910 | } |
1911 | ||
08e98fc6 ML |
1912 | static int blk_mq_init_hctx(struct request_queue *q, |
1913 | struct blk_mq_tag_set *set, | |
1914 | struct blk_mq_hw_ctx *hctx, unsigned hctx_idx) | |
320ae51f | 1915 | { |
08e98fc6 | 1916 | int node; |
f70ced09 | 1917 | unsigned flush_start_tag = set->queue_depth; |
08e98fc6 ML |
1918 | |
1919 | node = hctx->numa_node; | |
1920 | if (node == NUMA_NO_NODE) | |
1921 | node = hctx->numa_node = set->numa_node; | |
1922 | ||
27489a3c | 1923 | INIT_WORK(&hctx->run_work, blk_mq_run_work_fn); |
08e98fc6 ML |
1924 | INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn); |
1925 | spin_lock_init(&hctx->lock); | |
1926 | INIT_LIST_HEAD(&hctx->dispatch); | |
1927 | hctx->queue = q; | |
1928 | hctx->queue_num = hctx_idx; | |
2404e607 | 1929 | hctx->flags = set->flags & ~BLK_MQ_F_TAG_SHARED; |
08e98fc6 | 1930 | |
9467f859 | 1931 | cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, &hctx->cpuhp_dead); |
08e98fc6 ML |
1932 | |
1933 | hctx->tags = set->tags[hctx_idx]; | |
320ae51f JA |
1934 | |
1935 | /* | |
08e98fc6 ML |
1936 | * Allocate space for all possible cpus to avoid allocation at |
1937 | * runtime | |
320ae51f | 1938 | */ |
08e98fc6 ML |
1939 | hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *), |
1940 | GFP_KERNEL, node); | |
1941 | if (!hctx->ctxs) | |
1942 | goto unregister_cpu_notifier; | |
320ae51f | 1943 | |
88459642 OS |
1944 | if (sbitmap_init_node(&hctx->ctx_map, nr_cpu_ids, ilog2(8), GFP_KERNEL, |
1945 | node)) | |
08e98fc6 | 1946 | goto free_ctxs; |
320ae51f | 1947 | |
08e98fc6 | 1948 | hctx->nr_ctx = 0; |
320ae51f | 1949 | |
08e98fc6 ML |
1950 | if (set->ops->init_hctx && |
1951 | set->ops->init_hctx(hctx, set->driver_data, hctx_idx)) | |
1952 | goto free_bitmap; | |
320ae51f | 1953 | |
f70ced09 ML |
1954 | hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size); |
1955 | if (!hctx->fq) | |
1956 | goto exit_hctx; | |
320ae51f | 1957 | |
f70ced09 ML |
1958 | if (set->ops->init_request && |
1959 | set->ops->init_request(set->driver_data, | |
1960 | hctx->fq->flush_rq, hctx_idx, | |
1961 | flush_start_tag + hctx_idx, node)) | |
1962 | goto free_fq; | |
320ae51f | 1963 | |
6a83e74d BVA |
1964 | if (hctx->flags & BLK_MQ_F_BLOCKING) |
1965 | init_srcu_struct(&hctx->queue_rq_srcu); | |
1966 | ||
08e98fc6 | 1967 | return 0; |
320ae51f | 1968 | |
f70ced09 ML |
1969 | free_fq: |
1970 | kfree(hctx->fq); | |
1971 | exit_hctx: | |
1972 | if (set->ops->exit_hctx) | |
1973 | set->ops->exit_hctx(hctx, hctx_idx); | |
08e98fc6 | 1974 | free_bitmap: |
88459642 | 1975 | sbitmap_free(&hctx->ctx_map); |
08e98fc6 ML |
1976 | free_ctxs: |
1977 | kfree(hctx->ctxs); | |
1978 | unregister_cpu_notifier: | |
9467f859 | 1979 | blk_mq_remove_cpuhp(hctx); |
08e98fc6 ML |
1980 | return -1; |
1981 | } | |
320ae51f | 1982 | |
320ae51f JA |
1983 | static void blk_mq_init_cpu_queues(struct request_queue *q, |
1984 | unsigned int nr_hw_queues) | |
1985 | { | |
1986 | unsigned int i; | |
1987 | ||
1988 | for_each_possible_cpu(i) { | |
1989 | struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i); | |
1990 | struct blk_mq_hw_ctx *hctx; | |
1991 | ||
1992 | memset(__ctx, 0, sizeof(*__ctx)); | |
1993 | __ctx->cpu = i; | |
1994 | spin_lock_init(&__ctx->lock); | |
1995 | INIT_LIST_HEAD(&__ctx->rq_list); | |
1996 | __ctx->queue = q; | |
cf43e6be JA |
1997 | blk_stat_init(&__ctx->stat[BLK_STAT_READ]); |
1998 | blk_stat_init(&__ctx->stat[BLK_STAT_WRITE]); | |
320ae51f JA |
1999 | |
2000 | /* If the cpu isn't online, the cpu is mapped to first hctx */ | |
320ae51f JA |
2001 | if (!cpu_online(i)) |
2002 | continue; | |
2003 | ||
7d7e0f90 | 2004 | hctx = blk_mq_map_queue(q, i); |
e4043dcf | 2005 | |
320ae51f JA |
2006 | /* |
2007 | * Set local node, IFF we have more than one hw queue. If | |
2008 | * not, we remain on the home node of the device | |
2009 | */ | |
2010 | if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE) | |
bffed457 | 2011 | hctx->numa_node = local_memory_node(cpu_to_node(i)); |
320ae51f JA |
2012 | } |
2013 | } | |
2014 | ||
cc71a6f4 JA |
2015 | static bool __blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, int hctx_idx) |
2016 | { | |
2017 | int ret = 0; | |
2018 | ||
2019 | set->tags[hctx_idx] = blk_mq_alloc_rq_map(set, hctx_idx, | |
2020 | set->queue_depth, set->reserved_tags); | |
2021 | if (!set->tags[hctx_idx]) | |
2022 | return false; | |
2023 | ||
2024 | ret = blk_mq_alloc_rqs(set, set->tags[hctx_idx], hctx_idx, | |
2025 | set->queue_depth); | |
2026 | if (!ret) | |
2027 | return true; | |
2028 | ||
2029 | blk_mq_free_rq_map(set->tags[hctx_idx]); | |
2030 | set->tags[hctx_idx] = NULL; | |
2031 | return false; | |
2032 | } | |
2033 | ||
2034 | static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set, | |
2035 | unsigned int hctx_idx) | |
2036 | { | |
bd166ef1 JA |
2037 | if (set->tags[hctx_idx]) { |
2038 | blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx); | |
2039 | blk_mq_free_rq_map(set->tags[hctx_idx]); | |
2040 | set->tags[hctx_idx] = NULL; | |
2041 | } | |
cc71a6f4 JA |
2042 | } |
2043 | ||
5778322e AM |
2044 | static void blk_mq_map_swqueue(struct request_queue *q, |
2045 | const struct cpumask *online_mask) | |
320ae51f | 2046 | { |
d1b1cea1 | 2047 | unsigned int i, hctx_idx; |
320ae51f JA |
2048 | struct blk_mq_hw_ctx *hctx; |
2049 | struct blk_mq_ctx *ctx; | |
2a34c087 | 2050 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 2051 | |
60de074b AM |
2052 | /* |
2053 | * Avoid others reading imcomplete hctx->cpumask through sysfs | |
2054 | */ | |
2055 | mutex_lock(&q->sysfs_lock); | |
2056 | ||
320ae51f | 2057 | queue_for_each_hw_ctx(q, hctx, i) { |
e4043dcf | 2058 | cpumask_clear(hctx->cpumask); |
320ae51f JA |
2059 | hctx->nr_ctx = 0; |
2060 | } | |
2061 | ||
2062 | /* | |
2063 | * Map software to hardware queues | |
2064 | */ | |
897bb0c7 | 2065 | for_each_possible_cpu(i) { |
320ae51f | 2066 | /* If the cpu isn't online, the cpu is mapped to first hctx */ |
5778322e | 2067 | if (!cpumask_test_cpu(i, online_mask)) |
e4043dcf JA |
2068 | continue; |
2069 | ||
d1b1cea1 GKB |
2070 | hctx_idx = q->mq_map[i]; |
2071 | /* unmapped hw queue can be remapped after CPU topo changed */ | |
cc71a6f4 JA |
2072 | if (!set->tags[hctx_idx] && |
2073 | !__blk_mq_alloc_rq_map(set, hctx_idx)) { | |
d1b1cea1 GKB |
2074 | /* |
2075 | * If tags initialization fail for some hctx, | |
2076 | * that hctx won't be brought online. In this | |
2077 | * case, remap the current ctx to hctx[0] which | |
2078 | * is guaranteed to always have tags allocated | |
2079 | */ | |
cc71a6f4 | 2080 | q->mq_map[i] = 0; |
d1b1cea1 GKB |
2081 | } |
2082 | ||
897bb0c7 | 2083 | ctx = per_cpu_ptr(q->queue_ctx, i); |
7d7e0f90 | 2084 | hctx = blk_mq_map_queue(q, i); |
868f2f0b | 2085 | |
e4043dcf | 2086 | cpumask_set_cpu(i, hctx->cpumask); |
320ae51f JA |
2087 | ctx->index_hw = hctx->nr_ctx; |
2088 | hctx->ctxs[hctx->nr_ctx++] = ctx; | |
2089 | } | |
506e931f | 2090 | |
60de074b AM |
2091 | mutex_unlock(&q->sysfs_lock); |
2092 | ||
506e931f | 2093 | queue_for_each_hw_ctx(q, hctx, i) { |
484b4061 | 2094 | /* |
a68aafa5 JA |
2095 | * If no software queues are mapped to this hardware queue, |
2096 | * disable it and free the request entries. | |
484b4061 JA |
2097 | */ |
2098 | if (!hctx->nr_ctx) { | |
d1b1cea1 GKB |
2099 | /* Never unmap queue 0. We need it as a |
2100 | * fallback in case of a new remap fails | |
2101 | * allocation | |
2102 | */ | |
cc71a6f4 JA |
2103 | if (i && set->tags[i]) |
2104 | blk_mq_free_map_and_requests(set, i); | |
2105 | ||
2a34c087 | 2106 | hctx->tags = NULL; |
484b4061 JA |
2107 | continue; |
2108 | } | |
2109 | ||
2a34c087 ML |
2110 | hctx->tags = set->tags[i]; |
2111 | WARN_ON(!hctx->tags); | |
2112 | ||
889fa31f CY |
2113 | /* |
2114 | * Set the map size to the number of mapped software queues. | |
2115 | * This is more accurate and more efficient than looping | |
2116 | * over all possibly mapped software queues. | |
2117 | */ | |
88459642 | 2118 | sbitmap_resize(&hctx->ctx_map, hctx->nr_ctx); |
889fa31f | 2119 | |
484b4061 JA |
2120 | /* |
2121 | * Initialize batch roundrobin counts | |
2122 | */ | |
506e931f JA |
2123 | hctx->next_cpu = cpumask_first(hctx->cpumask); |
2124 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
2125 | } | |
320ae51f JA |
2126 | } |
2127 | ||
2404e607 | 2128 | static void queue_set_hctx_shared(struct request_queue *q, bool shared) |
0d2602ca JA |
2129 | { |
2130 | struct blk_mq_hw_ctx *hctx; | |
0d2602ca JA |
2131 | int i; |
2132 | ||
2404e607 JM |
2133 | queue_for_each_hw_ctx(q, hctx, i) { |
2134 | if (shared) | |
2135 | hctx->flags |= BLK_MQ_F_TAG_SHARED; | |
2136 | else | |
2137 | hctx->flags &= ~BLK_MQ_F_TAG_SHARED; | |
2138 | } | |
2139 | } | |
2140 | ||
2141 | static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set, bool shared) | |
2142 | { | |
2143 | struct request_queue *q; | |
0d2602ca JA |
2144 | |
2145 | list_for_each_entry(q, &set->tag_list, tag_set_list) { | |
2146 | blk_mq_freeze_queue(q); | |
2404e607 | 2147 | queue_set_hctx_shared(q, shared); |
0d2602ca JA |
2148 | blk_mq_unfreeze_queue(q); |
2149 | } | |
2150 | } | |
2151 | ||
2152 | static void blk_mq_del_queue_tag_set(struct request_queue *q) | |
2153 | { | |
2154 | struct blk_mq_tag_set *set = q->tag_set; | |
2155 | ||
0d2602ca JA |
2156 | mutex_lock(&set->tag_list_lock); |
2157 | list_del_init(&q->tag_set_list); | |
2404e607 JM |
2158 | if (list_is_singular(&set->tag_list)) { |
2159 | /* just transitioned to unshared */ | |
2160 | set->flags &= ~BLK_MQ_F_TAG_SHARED; | |
2161 | /* update existing queue */ | |
2162 | blk_mq_update_tag_set_depth(set, false); | |
2163 | } | |
0d2602ca | 2164 | mutex_unlock(&set->tag_list_lock); |
0d2602ca JA |
2165 | } |
2166 | ||
2167 | static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, | |
2168 | struct request_queue *q) | |
2169 | { | |
2170 | q->tag_set = set; | |
2171 | ||
2172 | mutex_lock(&set->tag_list_lock); | |
2404e607 JM |
2173 | |
2174 | /* Check to see if we're transitioning to shared (from 1 to 2 queues). */ | |
2175 | if (!list_empty(&set->tag_list) && !(set->flags & BLK_MQ_F_TAG_SHARED)) { | |
2176 | set->flags |= BLK_MQ_F_TAG_SHARED; | |
2177 | /* update existing queue */ | |
2178 | blk_mq_update_tag_set_depth(set, true); | |
2179 | } | |
2180 | if (set->flags & BLK_MQ_F_TAG_SHARED) | |
2181 | queue_set_hctx_shared(q, true); | |
0d2602ca | 2182 | list_add_tail(&q->tag_set_list, &set->tag_list); |
2404e607 | 2183 | |
0d2602ca JA |
2184 | mutex_unlock(&set->tag_list_lock); |
2185 | } | |
2186 | ||
e09aae7e ML |
2187 | /* |
2188 | * It is the actual release handler for mq, but we do it from | |
2189 | * request queue's release handler for avoiding use-after-free | |
2190 | * and headache because q->mq_kobj shouldn't have been introduced, | |
2191 | * but we can't group ctx/kctx kobj without it. | |
2192 | */ | |
2193 | void blk_mq_release(struct request_queue *q) | |
2194 | { | |
2195 | struct blk_mq_hw_ctx *hctx; | |
2196 | unsigned int i; | |
2197 | ||
bd166ef1 JA |
2198 | blk_mq_sched_teardown(q); |
2199 | ||
e09aae7e | 2200 | /* hctx kobj stays in hctx */ |
c3b4afca ML |
2201 | queue_for_each_hw_ctx(q, hctx, i) { |
2202 | if (!hctx) | |
2203 | continue; | |
2204 | kfree(hctx->ctxs); | |
e09aae7e | 2205 | kfree(hctx); |
c3b4afca | 2206 | } |
e09aae7e | 2207 | |
a723bab3 AM |
2208 | q->mq_map = NULL; |
2209 | ||
e09aae7e ML |
2210 | kfree(q->queue_hw_ctx); |
2211 | ||
2212 | /* ctx kobj stays in queue_ctx */ | |
2213 | free_percpu(q->queue_ctx); | |
2214 | } | |
2215 | ||
24d2f903 | 2216 | struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) |
b62c21b7 MS |
2217 | { |
2218 | struct request_queue *uninit_q, *q; | |
2219 | ||
2220 | uninit_q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node); | |
2221 | if (!uninit_q) | |
2222 | return ERR_PTR(-ENOMEM); | |
2223 | ||
2224 | q = blk_mq_init_allocated_queue(set, uninit_q); | |
2225 | if (IS_ERR(q)) | |
2226 | blk_cleanup_queue(uninit_q); | |
2227 | ||
2228 | return q; | |
2229 | } | |
2230 | EXPORT_SYMBOL(blk_mq_init_queue); | |
2231 | ||
868f2f0b KB |
2232 | static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, |
2233 | struct request_queue *q) | |
320ae51f | 2234 | { |
868f2f0b KB |
2235 | int i, j; |
2236 | struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx; | |
f14bbe77 | 2237 | |
868f2f0b | 2238 | blk_mq_sysfs_unregister(q); |
24d2f903 | 2239 | for (i = 0; i < set->nr_hw_queues; i++) { |
868f2f0b | 2240 | int node; |
f14bbe77 | 2241 | |
868f2f0b KB |
2242 | if (hctxs[i]) |
2243 | continue; | |
2244 | ||
2245 | node = blk_mq_hw_queue_to_node(q->mq_map, i); | |
cdef54dd CH |
2246 | hctxs[i] = kzalloc_node(sizeof(struct blk_mq_hw_ctx), |
2247 | GFP_KERNEL, node); | |
320ae51f | 2248 | if (!hctxs[i]) |
868f2f0b | 2249 | break; |
320ae51f | 2250 | |
a86073e4 | 2251 | if (!zalloc_cpumask_var_node(&hctxs[i]->cpumask, GFP_KERNEL, |
868f2f0b KB |
2252 | node)) { |
2253 | kfree(hctxs[i]); | |
2254 | hctxs[i] = NULL; | |
2255 | break; | |
2256 | } | |
e4043dcf | 2257 | |
0d2602ca | 2258 | atomic_set(&hctxs[i]->nr_active, 0); |
f14bbe77 | 2259 | hctxs[i]->numa_node = node; |
320ae51f | 2260 | hctxs[i]->queue_num = i; |
868f2f0b KB |
2261 | |
2262 | if (blk_mq_init_hctx(q, set, hctxs[i], i)) { | |
2263 | free_cpumask_var(hctxs[i]->cpumask); | |
2264 | kfree(hctxs[i]); | |
2265 | hctxs[i] = NULL; | |
2266 | break; | |
2267 | } | |
2268 | blk_mq_hctx_kobj_init(hctxs[i]); | |
320ae51f | 2269 | } |
868f2f0b KB |
2270 | for (j = i; j < q->nr_hw_queues; j++) { |
2271 | struct blk_mq_hw_ctx *hctx = hctxs[j]; | |
2272 | ||
2273 | if (hctx) { | |
cc71a6f4 JA |
2274 | if (hctx->tags) |
2275 | blk_mq_free_map_and_requests(set, j); | |
868f2f0b KB |
2276 | blk_mq_exit_hctx(q, set, hctx, j); |
2277 | free_cpumask_var(hctx->cpumask); | |
2278 | kobject_put(&hctx->kobj); | |
2279 | kfree(hctx->ctxs); | |
2280 | kfree(hctx); | |
2281 | hctxs[j] = NULL; | |
2282 | ||
2283 | } | |
2284 | } | |
2285 | q->nr_hw_queues = i; | |
2286 | blk_mq_sysfs_register(q); | |
2287 | } | |
2288 | ||
2289 | struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, | |
2290 | struct request_queue *q) | |
2291 | { | |
66841672 ML |
2292 | /* mark the queue as mq asap */ |
2293 | q->mq_ops = set->ops; | |
2294 | ||
868f2f0b KB |
2295 | q->queue_ctx = alloc_percpu(struct blk_mq_ctx); |
2296 | if (!q->queue_ctx) | |
c7de5726 | 2297 | goto err_exit; |
868f2f0b KB |
2298 | |
2299 | q->queue_hw_ctx = kzalloc_node(nr_cpu_ids * sizeof(*(q->queue_hw_ctx)), | |
2300 | GFP_KERNEL, set->numa_node); | |
2301 | if (!q->queue_hw_ctx) | |
2302 | goto err_percpu; | |
2303 | ||
bdd17e75 | 2304 | q->mq_map = set->mq_map; |
868f2f0b KB |
2305 | |
2306 | blk_mq_realloc_hw_ctxs(set, q); | |
2307 | if (!q->nr_hw_queues) | |
2308 | goto err_hctxs; | |
320ae51f | 2309 | |
287922eb | 2310 | INIT_WORK(&q->timeout_work, blk_mq_timeout_work); |
e56f698b | 2311 | blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ); |
320ae51f JA |
2312 | |
2313 | q->nr_queues = nr_cpu_ids; | |
320ae51f | 2314 | |
94eddfbe | 2315 | q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; |
320ae51f | 2316 | |
05f1dd53 JA |
2317 | if (!(set->flags & BLK_MQ_F_SG_MERGE)) |
2318 | q->queue_flags |= 1 << QUEUE_FLAG_NO_SG_MERGE; | |
2319 | ||
1be036e9 CH |
2320 | q->sg_reserved_size = INT_MAX; |
2321 | ||
2849450a | 2322 | INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work); |
6fca6a61 CH |
2323 | INIT_LIST_HEAD(&q->requeue_list); |
2324 | spin_lock_init(&q->requeue_lock); | |
2325 | ||
07068d5b JA |
2326 | if (q->nr_hw_queues > 1) |
2327 | blk_queue_make_request(q, blk_mq_make_request); | |
2328 | else | |
2329 | blk_queue_make_request(q, blk_sq_make_request); | |
2330 | ||
eba71768 JA |
2331 | /* |
2332 | * Do this after blk_queue_make_request() overrides it... | |
2333 | */ | |
2334 | q->nr_requests = set->queue_depth; | |
2335 | ||
64f1c21e JA |
2336 | /* |
2337 | * Default to classic polling | |
2338 | */ | |
2339 | q->poll_nsec = -1; | |
2340 | ||
24d2f903 CH |
2341 | if (set->ops->complete) |
2342 | blk_queue_softirq_done(q, set->ops->complete); | |
30a91cb4 | 2343 | |
24d2f903 | 2344 | blk_mq_init_cpu_queues(q, set->nr_hw_queues); |
320ae51f | 2345 | |
5778322e | 2346 | get_online_cpus(); |
320ae51f | 2347 | mutex_lock(&all_q_mutex); |
320ae51f | 2348 | |
4593fdbe | 2349 | list_add_tail(&q->all_q_node, &all_q_list); |
0d2602ca | 2350 | blk_mq_add_queue_tag_set(set, q); |
5778322e | 2351 | blk_mq_map_swqueue(q, cpu_online_mask); |
484b4061 | 2352 | |
4593fdbe | 2353 | mutex_unlock(&all_q_mutex); |
5778322e | 2354 | put_online_cpus(); |
4593fdbe | 2355 | |
d3484991 JA |
2356 | if (!(set->flags & BLK_MQ_F_NO_SCHED)) { |
2357 | int ret; | |
2358 | ||
2359 | ret = blk_mq_sched_init(q); | |
2360 | if (ret) | |
2361 | return ERR_PTR(ret); | |
2362 | } | |
2363 | ||
320ae51f | 2364 | return q; |
18741986 | 2365 | |
320ae51f | 2366 | err_hctxs: |
868f2f0b | 2367 | kfree(q->queue_hw_ctx); |
320ae51f | 2368 | err_percpu: |
868f2f0b | 2369 | free_percpu(q->queue_ctx); |
c7de5726 ML |
2370 | err_exit: |
2371 | q->mq_ops = NULL; | |
320ae51f JA |
2372 | return ERR_PTR(-ENOMEM); |
2373 | } | |
b62c21b7 | 2374 | EXPORT_SYMBOL(blk_mq_init_allocated_queue); |
320ae51f JA |
2375 | |
2376 | void blk_mq_free_queue(struct request_queue *q) | |
2377 | { | |
624dbe47 | 2378 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 2379 | |
0e626368 AM |
2380 | mutex_lock(&all_q_mutex); |
2381 | list_del_init(&q->all_q_node); | |
2382 | mutex_unlock(&all_q_mutex); | |
2383 | ||
87760e5e JA |
2384 | wbt_exit(q); |
2385 | ||
0d2602ca JA |
2386 | blk_mq_del_queue_tag_set(q); |
2387 | ||
624dbe47 ML |
2388 | blk_mq_exit_hw_queues(q, set, set->nr_hw_queues); |
2389 | blk_mq_free_hw_queues(q, set); | |
320ae51f | 2390 | } |
320ae51f JA |
2391 | |
2392 | /* Basically redo blk_mq_init_queue with queue frozen */ | |
5778322e AM |
2393 | static void blk_mq_queue_reinit(struct request_queue *q, |
2394 | const struct cpumask *online_mask) | |
320ae51f | 2395 | { |
4ecd4fef | 2396 | WARN_ON_ONCE(!atomic_read(&q->mq_freeze_depth)); |
320ae51f | 2397 | |
67aec14c JA |
2398 | blk_mq_sysfs_unregister(q); |
2399 | ||
320ae51f JA |
2400 | /* |
2401 | * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe | |
2402 | * we should change hctx numa_node according to new topology (this | |
2403 | * involves free and re-allocate memory, worthy doing?) | |
2404 | */ | |
2405 | ||
5778322e | 2406 | blk_mq_map_swqueue(q, online_mask); |
320ae51f | 2407 | |
67aec14c | 2408 | blk_mq_sysfs_register(q); |
320ae51f JA |
2409 | } |
2410 | ||
65d5291e SAS |
2411 | /* |
2412 | * New online cpumask which is going to be set in this hotplug event. | |
2413 | * Declare this cpumasks as global as cpu-hotplug operation is invoked | |
2414 | * one-by-one and dynamically allocating this could result in a failure. | |
2415 | */ | |
2416 | static struct cpumask cpuhp_online_new; | |
2417 | ||
2418 | static void blk_mq_queue_reinit_work(void) | |
320ae51f JA |
2419 | { |
2420 | struct request_queue *q; | |
320ae51f JA |
2421 | |
2422 | mutex_lock(&all_q_mutex); | |
f3af020b TH |
2423 | /* |
2424 | * We need to freeze and reinit all existing queues. Freezing | |
2425 | * involves synchronous wait for an RCU grace period and doing it | |
2426 | * one by one may take a long time. Start freezing all queues in | |
2427 | * one swoop and then wait for the completions so that freezing can | |
2428 | * take place in parallel. | |
2429 | */ | |
2430 | list_for_each_entry(q, &all_q_list, all_q_node) | |
2431 | blk_mq_freeze_queue_start(q); | |
415d3dab | 2432 | list_for_each_entry(q, &all_q_list, all_q_node) |
f3af020b TH |
2433 | blk_mq_freeze_queue_wait(q); |
2434 | ||
320ae51f | 2435 | list_for_each_entry(q, &all_q_list, all_q_node) |
65d5291e | 2436 | blk_mq_queue_reinit(q, &cpuhp_online_new); |
f3af020b TH |
2437 | |
2438 | list_for_each_entry(q, &all_q_list, all_q_node) | |
2439 | blk_mq_unfreeze_queue(q); | |
2440 | ||
320ae51f | 2441 | mutex_unlock(&all_q_mutex); |
65d5291e SAS |
2442 | } |
2443 | ||
2444 | static int blk_mq_queue_reinit_dead(unsigned int cpu) | |
2445 | { | |
97a32864 | 2446 | cpumask_copy(&cpuhp_online_new, cpu_online_mask); |
65d5291e SAS |
2447 | blk_mq_queue_reinit_work(); |
2448 | return 0; | |
2449 | } | |
2450 | ||
2451 | /* | |
2452 | * Before hotadded cpu starts handling requests, new mappings must be | |
2453 | * established. Otherwise, these requests in hw queue might never be | |
2454 | * dispatched. | |
2455 | * | |
2456 | * For example, there is a single hw queue (hctx) and two CPU queues (ctx0 | |
2457 | * for CPU0, and ctx1 for CPU1). | |
2458 | * | |
2459 | * Now CPU1 is just onlined and a request is inserted into ctx1->rq_list | |
2460 | * and set bit0 in pending bitmap as ctx1->index_hw is still zero. | |
2461 | * | |
2c3ad667 JA |
2462 | * And then while running hw queue, blk_mq_flush_busy_ctxs() finds bit0 is set |
2463 | * in pending bitmap and tries to retrieve requests in hctx->ctxs[0]->rq_list. | |
2464 | * But htx->ctxs[0] is a pointer to ctx0, so the request in ctx1->rq_list is | |
2465 | * ignored. | |
65d5291e SAS |
2466 | */ |
2467 | static int blk_mq_queue_reinit_prepare(unsigned int cpu) | |
2468 | { | |
2469 | cpumask_copy(&cpuhp_online_new, cpu_online_mask); | |
2470 | cpumask_set_cpu(cpu, &cpuhp_online_new); | |
2471 | blk_mq_queue_reinit_work(); | |
2472 | return 0; | |
320ae51f JA |
2473 | } |
2474 | ||
a5164405 JA |
2475 | static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) |
2476 | { | |
2477 | int i; | |
2478 | ||
cc71a6f4 JA |
2479 | for (i = 0; i < set->nr_hw_queues; i++) |
2480 | if (!__blk_mq_alloc_rq_map(set, i)) | |
a5164405 | 2481 | goto out_unwind; |
a5164405 JA |
2482 | |
2483 | return 0; | |
2484 | ||
2485 | out_unwind: | |
2486 | while (--i >= 0) | |
cc71a6f4 | 2487 | blk_mq_free_rq_map(set->tags[i]); |
a5164405 | 2488 | |
a5164405 JA |
2489 | return -ENOMEM; |
2490 | } | |
2491 | ||
2492 | /* | |
2493 | * Allocate the request maps associated with this tag_set. Note that this | |
2494 | * may reduce the depth asked for, if memory is tight. set->queue_depth | |
2495 | * will be updated to reflect the allocated depth. | |
2496 | */ | |
2497 | static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) | |
2498 | { | |
2499 | unsigned int depth; | |
2500 | int err; | |
2501 | ||
2502 | depth = set->queue_depth; | |
2503 | do { | |
2504 | err = __blk_mq_alloc_rq_maps(set); | |
2505 | if (!err) | |
2506 | break; | |
2507 | ||
2508 | set->queue_depth >>= 1; | |
2509 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) { | |
2510 | err = -ENOMEM; | |
2511 | break; | |
2512 | } | |
2513 | } while (set->queue_depth); | |
2514 | ||
2515 | if (!set->queue_depth || err) { | |
2516 | pr_err("blk-mq: failed to allocate request map\n"); | |
2517 | return -ENOMEM; | |
2518 | } | |
2519 | ||
2520 | if (depth != set->queue_depth) | |
2521 | pr_info("blk-mq: reduced tag depth (%u -> %u)\n", | |
2522 | depth, set->queue_depth); | |
2523 | ||
2524 | return 0; | |
2525 | } | |
2526 | ||
a4391c64 JA |
2527 | /* |
2528 | * Alloc a tag set to be associated with one or more request queues. | |
2529 | * May fail with EINVAL for various error conditions. May adjust the | |
2530 | * requested depth down, if if it too large. In that case, the set | |
2531 | * value will be stored in set->queue_depth. | |
2532 | */ | |
24d2f903 CH |
2533 | int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) |
2534 | { | |
da695ba2 CH |
2535 | int ret; |
2536 | ||
205fb5f5 BVA |
2537 | BUILD_BUG_ON(BLK_MQ_MAX_DEPTH > 1 << BLK_MQ_UNIQUE_TAG_BITS); |
2538 | ||
24d2f903 CH |
2539 | if (!set->nr_hw_queues) |
2540 | return -EINVAL; | |
a4391c64 | 2541 | if (!set->queue_depth) |
24d2f903 CH |
2542 | return -EINVAL; |
2543 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) | |
2544 | return -EINVAL; | |
2545 | ||
7d7e0f90 | 2546 | if (!set->ops->queue_rq) |
24d2f903 CH |
2547 | return -EINVAL; |
2548 | ||
a4391c64 JA |
2549 | if (set->queue_depth > BLK_MQ_MAX_DEPTH) { |
2550 | pr_info("blk-mq: reduced tag depth to %u\n", | |
2551 | BLK_MQ_MAX_DEPTH); | |
2552 | set->queue_depth = BLK_MQ_MAX_DEPTH; | |
2553 | } | |
24d2f903 | 2554 | |
6637fadf SL |
2555 | /* |
2556 | * If a crashdump is active, then we are potentially in a very | |
2557 | * memory constrained environment. Limit us to 1 queue and | |
2558 | * 64 tags to prevent using too much memory. | |
2559 | */ | |
2560 | if (is_kdump_kernel()) { | |
2561 | set->nr_hw_queues = 1; | |
2562 | set->queue_depth = min(64U, set->queue_depth); | |
2563 | } | |
868f2f0b KB |
2564 | /* |
2565 | * There is no use for more h/w queues than cpus. | |
2566 | */ | |
2567 | if (set->nr_hw_queues > nr_cpu_ids) | |
2568 | set->nr_hw_queues = nr_cpu_ids; | |
6637fadf | 2569 | |
868f2f0b | 2570 | set->tags = kzalloc_node(nr_cpu_ids * sizeof(struct blk_mq_tags *), |
24d2f903 CH |
2571 | GFP_KERNEL, set->numa_node); |
2572 | if (!set->tags) | |
a5164405 | 2573 | return -ENOMEM; |
24d2f903 | 2574 | |
da695ba2 CH |
2575 | ret = -ENOMEM; |
2576 | set->mq_map = kzalloc_node(sizeof(*set->mq_map) * nr_cpu_ids, | |
2577 | GFP_KERNEL, set->numa_node); | |
bdd17e75 CH |
2578 | if (!set->mq_map) |
2579 | goto out_free_tags; | |
2580 | ||
da695ba2 CH |
2581 | if (set->ops->map_queues) |
2582 | ret = set->ops->map_queues(set); | |
2583 | else | |
2584 | ret = blk_mq_map_queues(set); | |
2585 | if (ret) | |
2586 | goto out_free_mq_map; | |
2587 | ||
2588 | ret = blk_mq_alloc_rq_maps(set); | |
2589 | if (ret) | |
bdd17e75 | 2590 | goto out_free_mq_map; |
24d2f903 | 2591 | |
0d2602ca JA |
2592 | mutex_init(&set->tag_list_lock); |
2593 | INIT_LIST_HEAD(&set->tag_list); | |
2594 | ||
24d2f903 | 2595 | return 0; |
bdd17e75 CH |
2596 | |
2597 | out_free_mq_map: | |
2598 | kfree(set->mq_map); | |
2599 | set->mq_map = NULL; | |
2600 | out_free_tags: | |
5676e7b6 RE |
2601 | kfree(set->tags); |
2602 | set->tags = NULL; | |
da695ba2 | 2603 | return ret; |
24d2f903 CH |
2604 | } |
2605 | EXPORT_SYMBOL(blk_mq_alloc_tag_set); | |
2606 | ||
2607 | void blk_mq_free_tag_set(struct blk_mq_tag_set *set) | |
2608 | { | |
2609 | int i; | |
2610 | ||
cc71a6f4 JA |
2611 | for (i = 0; i < nr_cpu_ids; i++) |
2612 | blk_mq_free_map_and_requests(set, i); | |
484b4061 | 2613 | |
bdd17e75 CH |
2614 | kfree(set->mq_map); |
2615 | set->mq_map = NULL; | |
2616 | ||
981bd189 | 2617 | kfree(set->tags); |
5676e7b6 | 2618 | set->tags = NULL; |
24d2f903 CH |
2619 | } |
2620 | EXPORT_SYMBOL(blk_mq_free_tag_set); | |
2621 | ||
e3a2b3f9 JA |
2622 | int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) |
2623 | { | |
2624 | struct blk_mq_tag_set *set = q->tag_set; | |
2625 | struct blk_mq_hw_ctx *hctx; | |
2626 | int i, ret; | |
2627 | ||
bd166ef1 | 2628 | if (!set) |
e3a2b3f9 JA |
2629 | return -EINVAL; |
2630 | ||
70f36b60 JA |
2631 | blk_mq_freeze_queue(q); |
2632 | blk_mq_quiesce_queue(q); | |
2633 | ||
e3a2b3f9 JA |
2634 | ret = 0; |
2635 | queue_for_each_hw_ctx(q, hctx, i) { | |
e9137d4b KB |
2636 | if (!hctx->tags) |
2637 | continue; | |
bd166ef1 JA |
2638 | /* |
2639 | * If we're using an MQ scheduler, just update the scheduler | |
2640 | * queue depth. This is similar to what the old code would do. | |
2641 | */ | |
70f36b60 JA |
2642 | if (!hctx->sched_tags) { |
2643 | ret = blk_mq_tag_update_depth(hctx, &hctx->tags, | |
2644 | min(nr, set->queue_depth), | |
2645 | false); | |
2646 | } else { | |
2647 | ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags, | |
2648 | nr, true); | |
2649 | } | |
e3a2b3f9 JA |
2650 | if (ret) |
2651 | break; | |
2652 | } | |
2653 | ||
2654 | if (!ret) | |
2655 | q->nr_requests = nr; | |
2656 | ||
70f36b60 JA |
2657 | blk_mq_unfreeze_queue(q); |
2658 | blk_mq_start_stopped_hw_queues(q, true); | |
2659 | ||
e3a2b3f9 JA |
2660 | return ret; |
2661 | } | |
2662 | ||
868f2f0b KB |
2663 | void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues) |
2664 | { | |
2665 | struct request_queue *q; | |
2666 | ||
2667 | if (nr_hw_queues > nr_cpu_ids) | |
2668 | nr_hw_queues = nr_cpu_ids; | |
2669 | if (nr_hw_queues < 1 || nr_hw_queues == set->nr_hw_queues) | |
2670 | return; | |
2671 | ||
2672 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
2673 | blk_mq_freeze_queue(q); | |
2674 | ||
2675 | set->nr_hw_queues = nr_hw_queues; | |
2676 | list_for_each_entry(q, &set->tag_list, tag_set_list) { | |
2677 | blk_mq_realloc_hw_ctxs(set, q); | |
2678 | ||
f6f94300 JB |
2679 | /* |
2680 | * Manually set the make_request_fn as blk_queue_make_request | |
2681 | * resets a lot of the queue settings. | |
2682 | */ | |
868f2f0b | 2683 | if (q->nr_hw_queues > 1) |
f6f94300 | 2684 | q->make_request_fn = blk_mq_make_request; |
868f2f0b | 2685 | else |
f6f94300 | 2686 | q->make_request_fn = blk_sq_make_request; |
868f2f0b KB |
2687 | |
2688 | blk_mq_queue_reinit(q, cpu_online_mask); | |
2689 | } | |
2690 | ||
2691 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
2692 | blk_mq_unfreeze_queue(q); | |
2693 | } | |
2694 | EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues); | |
2695 | ||
64f1c21e JA |
2696 | static unsigned long blk_mq_poll_nsecs(struct request_queue *q, |
2697 | struct blk_mq_hw_ctx *hctx, | |
2698 | struct request *rq) | |
2699 | { | |
2700 | struct blk_rq_stat stat[2]; | |
2701 | unsigned long ret = 0; | |
2702 | ||
2703 | /* | |
2704 | * If stats collection isn't on, don't sleep but turn it on for | |
2705 | * future users | |
2706 | */ | |
2707 | if (!blk_stat_enable(q)) | |
2708 | return 0; | |
2709 | ||
2710 | /* | |
2711 | * We don't have to do this once per IO, should optimize this | |
2712 | * to just use the current window of stats until it changes | |
2713 | */ | |
2714 | memset(&stat, 0, sizeof(stat)); | |
2715 | blk_hctx_stat_get(hctx, stat); | |
2716 | ||
2717 | /* | |
2718 | * As an optimistic guess, use half of the mean service time | |
2719 | * for this type of request. We can (and should) make this smarter. | |
2720 | * For instance, if the completion latencies are tight, we can | |
2721 | * get closer than just half the mean. This is especially | |
2722 | * important on devices where the completion latencies are longer | |
2723 | * than ~10 usec. | |
2724 | */ | |
2725 | if (req_op(rq) == REQ_OP_READ && stat[BLK_STAT_READ].nr_samples) | |
2726 | ret = (stat[BLK_STAT_READ].mean + 1) / 2; | |
2727 | else if (req_op(rq) == REQ_OP_WRITE && stat[BLK_STAT_WRITE].nr_samples) | |
2728 | ret = (stat[BLK_STAT_WRITE].mean + 1) / 2; | |
2729 | ||
2730 | return ret; | |
2731 | } | |
2732 | ||
06426adf | 2733 | static bool blk_mq_poll_hybrid_sleep(struct request_queue *q, |
64f1c21e | 2734 | struct blk_mq_hw_ctx *hctx, |
06426adf JA |
2735 | struct request *rq) |
2736 | { | |
2737 | struct hrtimer_sleeper hs; | |
2738 | enum hrtimer_mode mode; | |
64f1c21e | 2739 | unsigned int nsecs; |
06426adf JA |
2740 | ktime_t kt; |
2741 | ||
64f1c21e JA |
2742 | if (test_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags)) |
2743 | return false; | |
2744 | ||
2745 | /* | |
2746 | * poll_nsec can be: | |
2747 | * | |
2748 | * -1: don't ever hybrid sleep | |
2749 | * 0: use half of prev avg | |
2750 | * >0: use this specific value | |
2751 | */ | |
2752 | if (q->poll_nsec == -1) | |
2753 | return false; | |
2754 | else if (q->poll_nsec > 0) | |
2755 | nsecs = q->poll_nsec; | |
2756 | else | |
2757 | nsecs = blk_mq_poll_nsecs(q, hctx, rq); | |
2758 | ||
2759 | if (!nsecs) | |
06426adf JA |
2760 | return false; |
2761 | ||
2762 | set_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags); | |
2763 | ||
2764 | /* | |
2765 | * This will be replaced with the stats tracking code, using | |
2766 | * 'avg_completion_time / 2' as the pre-sleep target. | |
2767 | */ | |
8b0e1953 | 2768 | kt = nsecs; |
06426adf JA |
2769 | |
2770 | mode = HRTIMER_MODE_REL; | |
2771 | hrtimer_init_on_stack(&hs.timer, CLOCK_MONOTONIC, mode); | |
2772 | hrtimer_set_expires(&hs.timer, kt); | |
2773 | ||
2774 | hrtimer_init_sleeper(&hs, current); | |
2775 | do { | |
2776 | if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) | |
2777 | break; | |
2778 | set_current_state(TASK_UNINTERRUPTIBLE); | |
2779 | hrtimer_start_expires(&hs.timer, mode); | |
2780 | if (hs.task) | |
2781 | io_schedule(); | |
2782 | hrtimer_cancel(&hs.timer); | |
2783 | mode = HRTIMER_MODE_ABS; | |
2784 | } while (hs.task && !signal_pending(current)); | |
2785 | ||
2786 | __set_current_state(TASK_RUNNING); | |
2787 | destroy_hrtimer_on_stack(&hs.timer); | |
2788 | return true; | |
2789 | } | |
2790 | ||
bbd7bb70 JA |
2791 | static bool __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq) |
2792 | { | |
2793 | struct request_queue *q = hctx->queue; | |
2794 | long state; | |
2795 | ||
06426adf JA |
2796 | /* |
2797 | * If we sleep, have the caller restart the poll loop to reset | |
2798 | * the state. Like for the other success return cases, the | |
2799 | * caller is responsible for checking if the IO completed. If | |
2800 | * the IO isn't complete, we'll get called again and will go | |
2801 | * straight to the busy poll loop. | |
2802 | */ | |
64f1c21e | 2803 | if (blk_mq_poll_hybrid_sleep(q, hctx, rq)) |
06426adf JA |
2804 | return true; |
2805 | ||
bbd7bb70 JA |
2806 | hctx->poll_considered++; |
2807 | ||
2808 | state = current->state; | |
2809 | while (!need_resched()) { | |
2810 | int ret; | |
2811 | ||
2812 | hctx->poll_invoked++; | |
2813 | ||
2814 | ret = q->mq_ops->poll(hctx, rq->tag); | |
2815 | if (ret > 0) { | |
2816 | hctx->poll_success++; | |
2817 | set_current_state(TASK_RUNNING); | |
2818 | return true; | |
2819 | } | |
2820 | ||
2821 | if (signal_pending_state(state, current)) | |
2822 | set_current_state(TASK_RUNNING); | |
2823 | ||
2824 | if (current->state == TASK_RUNNING) | |
2825 | return true; | |
2826 | if (ret < 0) | |
2827 | break; | |
2828 | cpu_relax(); | |
2829 | } | |
2830 | ||
2831 | return false; | |
2832 | } | |
2833 | ||
2834 | bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie) | |
2835 | { | |
2836 | struct blk_mq_hw_ctx *hctx; | |
2837 | struct blk_plug *plug; | |
2838 | struct request *rq; | |
2839 | ||
2840 | if (!q->mq_ops || !q->mq_ops->poll || !blk_qc_t_valid(cookie) || | |
2841 | !test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) | |
2842 | return false; | |
2843 | ||
2844 | plug = current->plug; | |
2845 | if (plug) | |
2846 | blk_flush_plug_list(plug, false); | |
2847 | ||
2848 | hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)]; | |
bd166ef1 JA |
2849 | if (!blk_qc_t_is_internal(cookie)) |
2850 | rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie)); | |
2851 | else | |
2852 | rq = blk_mq_tag_to_rq(hctx->sched_tags, blk_qc_t_to_tag(cookie)); | |
bbd7bb70 JA |
2853 | |
2854 | return __blk_mq_poll(hctx, rq); | |
2855 | } | |
2856 | EXPORT_SYMBOL_GPL(blk_mq_poll); | |
2857 | ||
676141e4 JA |
2858 | void blk_mq_disable_hotplug(void) |
2859 | { | |
2860 | mutex_lock(&all_q_mutex); | |
2861 | } | |
2862 | ||
2863 | void blk_mq_enable_hotplug(void) | |
2864 | { | |
2865 | mutex_unlock(&all_q_mutex); | |
2866 | } | |
2867 | ||
320ae51f JA |
2868 | static int __init blk_mq_init(void) |
2869 | { | |
9467f859 TG |
2870 | cpuhp_setup_state_multi(CPUHP_BLK_MQ_DEAD, "block/mq:dead", NULL, |
2871 | blk_mq_hctx_notify_dead); | |
320ae51f | 2872 | |
65d5291e SAS |
2873 | cpuhp_setup_state_nocalls(CPUHP_BLK_MQ_PREPARE, "block/mq:prepare", |
2874 | blk_mq_queue_reinit_prepare, | |
2875 | blk_mq_queue_reinit_dead); | |
320ae51f JA |
2876 | return 0; |
2877 | } | |
2878 | subsys_initcall(blk_mq_init); |