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3dcf60bc | 1 | // SPDX-License-Identifier: GPL-2.0 |
75bb4625 JA |
2 | /* |
3 | * Block multiqueue core code | |
4 | * | |
5 | * Copyright (C) 2013-2014 Jens Axboe | |
6 | * Copyright (C) 2013-2014 Christoph Hellwig | |
7 | */ | |
320ae51f JA |
8 | #include <linux/kernel.h> |
9 | #include <linux/module.h> | |
10 | #include <linux/backing-dev.h> | |
11 | #include <linux/bio.h> | |
12 | #include <linux/blkdev.h> | |
f75782e4 | 13 | #include <linux/kmemleak.h> |
320ae51f JA |
14 | #include <linux/mm.h> |
15 | #include <linux/init.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/workqueue.h> | |
18 | #include <linux/smp.h> | |
19 | #include <linux/llist.h> | |
20 | #include <linux/list_sort.h> | |
21 | #include <linux/cpu.h> | |
22 | #include <linux/cache.h> | |
23 | #include <linux/sched/sysctl.h> | |
105ab3d8 | 24 | #include <linux/sched/topology.h> |
174cd4b1 | 25 | #include <linux/sched/signal.h> |
320ae51f | 26 | #include <linux/delay.h> |
aedcd72f | 27 | #include <linux/crash_dump.h> |
88c7b2b7 | 28 | #include <linux/prefetch.h> |
320ae51f JA |
29 | |
30 | #include <trace/events/block.h> | |
31 | ||
32 | #include <linux/blk-mq.h> | |
54d4e6ab | 33 | #include <linux/t10-pi.h> |
320ae51f JA |
34 | #include "blk.h" |
35 | #include "blk-mq.h" | |
9c1051aa | 36 | #include "blk-mq-debugfs.h" |
320ae51f | 37 | #include "blk-mq-tag.h" |
986d413b | 38 | #include "blk-pm.h" |
cf43e6be | 39 | #include "blk-stat.h" |
bd166ef1 | 40 | #include "blk-mq-sched.h" |
c1c80384 | 41 | #include "blk-rq-qos.h" |
320ae51f | 42 | |
34dbad5d OS |
43 | static void blk_mq_poll_stats_start(struct request_queue *q); |
44 | static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb); | |
45 | ||
720b8ccc SB |
46 | static int blk_mq_poll_stats_bkt(const struct request *rq) |
47 | { | |
3d244306 | 48 | int ddir, sectors, bucket; |
720b8ccc | 49 | |
99c749a4 | 50 | ddir = rq_data_dir(rq); |
3d244306 | 51 | sectors = blk_rq_stats_sectors(rq); |
720b8ccc | 52 | |
3d244306 | 53 | bucket = ddir + 2 * ilog2(sectors); |
720b8ccc SB |
54 | |
55 | if (bucket < 0) | |
56 | return -1; | |
57 | else if (bucket >= BLK_MQ_POLL_STATS_BKTS) | |
58 | return ddir + BLK_MQ_POLL_STATS_BKTS - 2; | |
59 | ||
60 | return bucket; | |
61 | } | |
62 | ||
320ae51f | 63 | /* |
85fae294 YY |
64 | * Check if any of the ctx, dispatch list or elevator |
65 | * have pending work in this hardware queue. | |
320ae51f | 66 | */ |
79f720a7 | 67 | static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx) |
320ae51f | 68 | { |
79f720a7 JA |
69 | return !list_empty_careful(&hctx->dispatch) || |
70 | sbitmap_any_bit_set(&hctx->ctx_map) || | |
bd166ef1 | 71 | blk_mq_sched_has_work(hctx); |
1429d7c9 JA |
72 | } |
73 | ||
320ae51f JA |
74 | /* |
75 | * Mark this ctx as having pending work in this hardware queue | |
76 | */ | |
77 | static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx, | |
78 | struct blk_mq_ctx *ctx) | |
79 | { | |
f31967f0 JA |
80 | const int bit = ctx->index_hw[hctx->type]; |
81 | ||
82 | if (!sbitmap_test_bit(&hctx->ctx_map, bit)) | |
83 | sbitmap_set_bit(&hctx->ctx_map, bit); | |
1429d7c9 JA |
84 | } |
85 | ||
86 | static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx, | |
87 | struct blk_mq_ctx *ctx) | |
88 | { | |
f31967f0 JA |
89 | const int bit = ctx->index_hw[hctx->type]; |
90 | ||
91 | sbitmap_clear_bit(&hctx->ctx_map, bit); | |
320ae51f JA |
92 | } |
93 | ||
f299b7c7 JA |
94 | struct mq_inflight { |
95 | struct hd_struct *part; | |
96 | unsigned int *inflight; | |
97 | }; | |
98 | ||
7baa8572 | 99 | static bool blk_mq_check_inflight(struct blk_mq_hw_ctx *hctx, |
f299b7c7 JA |
100 | struct request *rq, void *priv, |
101 | bool reserved) | |
102 | { | |
103 | struct mq_inflight *mi = priv; | |
104 | ||
6131837b | 105 | /* |
e016b782 | 106 | * index[0] counts the specific partition that was asked for. |
6131837b OS |
107 | */ |
108 | if (rq->part == mi->part) | |
109 | mi->inflight[0]++; | |
7baa8572 JA |
110 | |
111 | return true; | |
f299b7c7 JA |
112 | } |
113 | ||
e016b782 | 114 | unsigned int blk_mq_in_flight(struct request_queue *q, struct hd_struct *part) |
f299b7c7 | 115 | { |
e016b782 | 116 | unsigned inflight[2]; |
f299b7c7 JA |
117 | struct mq_inflight mi = { .part = part, .inflight = inflight, }; |
118 | ||
b8d62b3a | 119 | inflight[0] = inflight[1] = 0; |
f299b7c7 | 120 | blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi); |
e016b782 MP |
121 | |
122 | return inflight[0]; | |
f299b7c7 JA |
123 | } |
124 | ||
7baa8572 | 125 | static bool blk_mq_check_inflight_rw(struct blk_mq_hw_ctx *hctx, |
bf0ddaba OS |
126 | struct request *rq, void *priv, |
127 | bool reserved) | |
128 | { | |
129 | struct mq_inflight *mi = priv; | |
130 | ||
131 | if (rq->part == mi->part) | |
132 | mi->inflight[rq_data_dir(rq)]++; | |
7baa8572 JA |
133 | |
134 | return true; | |
bf0ddaba OS |
135 | } |
136 | ||
137 | void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part, | |
138 | unsigned int inflight[2]) | |
139 | { | |
140 | struct mq_inflight mi = { .part = part, .inflight = inflight, }; | |
141 | ||
142 | inflight[0] = inflight[1] = 0; | |
143 | blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight_rw, &mi); | |
144 | } | |
145 | ||
1671d522 | 146 | void blk_freeze_queue_start(struct request_queue *q) |
43a5e4e2 | 147 | { |
7996a8b5 BL |
148 | mutex_lock(&q->mq_freeze_lock); |
149 | if (++q->mq_freeze_depth == 1) { | |
3ef28e83 | 150 | percpu_ref_kill(&q->q_usage_counter); |
7996a8b5 | 151 | mutex_unlock(&q->mq_freeze_lock); |
344e9ffc | 152 | if (queue_is_mq(q)) |
055f6e18 | 153 | blk_mq_run_hw_queues(q, false); |
7996a8b5 BL |
154 | } else { |
155 | mutex_unlock(&q->mq_freeze_lock); | |
cddd5d17 | 156 | } |
f3af020b | 157 | } |
1671d522 | 158 | EXPORT_SYMBOL_GPL(blk_freeze_queue_start); |
f3af020b | 159 | |
6bae363e | 160 | void blk_mq_freeze_queue_wait(struct request_queue *q) |
f3af020b | 161 | { |
3ef28e83 | 162 | wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter)); |
43a5e4e2 | 163 | } |
6bae363e | 164 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait); |
43a5e4e2 | 165 | |
f91328c4 KB |
166 | int blk_mq_freeze_queue_wait_timeout(struct request_queue *q, |
167 | unsigned long timeout) | |
168 | { | |
169 | return wait_event_timeout(q->mq_freeze_wq, | |
170 | percpu_ref_is_zero(&q->q_usage_counter), | |
171 | timeout); | |
172 | } | |
173 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait_timeout); | |
43a5e4e2 | 174 | |
f3af020b TH |
175 | /* |
176 | * Guarantee no request is in use, so we can change any data structure of | |
177 | * the queue afterward. | |
178 | */ | |
3ef28e83 | 179 | void blk_freeze_queue(struct request_queue *q) |
f3af020b | 180 | { |
3ef28e83 DW |
181 | /* |
182 | * In the !blk_mq case we are only calling this to kill the | |
183 | * q_usage_counter, otherwise this increases the freeze depth | |
184 | * and waits for it to return to zero. For this reason there is | |
185 | * no blk_unfreeze_queue(), and blk_freeze_queue() is not | |
186 | * exported to drivers as the only user for unfreeze is blk_mq. | |
187 | */ | |
1671d522 | 188 | blk_freeze_queue_start(q); |
f3af020b TH |
189 | blk_mq_freeze_queue_wait(q); |
190 | } | |
3ef28e83 DW |
191 | |
192 | void blk_mq_freeze_queue(struct request_queue *q) | |
193 | { | |
194 | /* | |
195 | * ...just an alias to keep freeze and unfreeze actions balanced | |
196 | * in the blk_mq_* namespace | |
197 | */ | |
198 | blk_freeze_queue(q); | |
199 | } | |
c761d96b | 200 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue); |
f3af020b | 201 | |
b4c6a028 | 202 | void blk_mq_unfreeze_queue(struct request_queue *q) |
320ae51f | 203 | { |
7996a8b5 BL |
204 | mutex_lock(&q->mq_freeze_lock); |
205 | q->mq_freeze_depth--; | |
206 | WARN_ON_ONCE(q->mq_freeze_depth < 0); | |
207 | if (!q->mq_freeze_depth) { | |
bdd63160 | 208 | percpu_ref_resurrect(&q->q_usage_counter); |
320ae51f | 209 | wake_up_all(&q->mq_freeze_wq); |
add703fd | 210 | } |
7996a8b5 | 211 | mutex_unlock(&q->mq_freeze_lock); |
320ae51f | 212 | } |
b4c6a028 | 213 | EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue); |
320ae51f | 214 | |
852ec809 BVA |
215 | /* |
216 | * FIXME: replace the scsi_internal_device_*block_nowait() calls in the | |
217 | * mpt3sas driver such that this function can be removed. | |
218 | */ | |
219 | void blk_mq_quiesce_queue_nowait(struct request_queue *q) | |
220 | { | |
8814ce8a | 221 | blk_queue_flag_set(QUEUE_FLAG_QUIESCED, q); |
852ec809 BVA |
222 | } |
223 | EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue_nowait); | |
224 | ||
6a83e74d | 225 | /** |
69e07c4a | 226 | * blk_mq_quiesce_queue() - wait until all ongoing dispatches have finished |
6a83e74d BVA |
227 | * @q: request queue. |
228 | * | |
229 | * Note: this function does not prevent that the struct request end_io() | |
69e07c4a ML |
230 | * callback function is invoked. Once this function is returned, we make |
231 | * sure no dispatch can happen until the queue is unquiesced via | |
232 | * blk_mq_unquiesce_queue(). | |
6a83e74d BVA |
233 | */ |
234 | void blk_mq_quiesce_queue(struct request_queue *q) | |
235 | { | |
236 | struct blk_mq_hw_ctx *hctx; | |
237 | unsigned int i; | |
238 | bool rcu = false; | |
239 | ||
1d9e9bc6 | 240 | blk_mq_quiesce_queue_nowait(q); |
f4560ffe | 241 | |
6a83e74d BVA |
242 | queue_for_each_hw_ctx(q, hctx, i) { |
243 | if (hctx->flags & BLK_MQ_F_BLOCKING) | |
05707b64 | 244 | synchronize_srcu(hctx->srcu); |
6a83e74d BVA |
245 | else |
246 | rcu = true; | |
247 | } | |
248 | if (rcu) | |
249 | synchronize_rcu(); | |
250 | } | |
251 | EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue); | |
252 | ||
e4e73913 ML |
253 | /* |
254 | * blk_mq_unquiesce_queue() - counterpart of blk_mq_quiesce_queue() | |
255 | * @q: request queue. | |
256 | * | |
257 | * This function recovers queue into the state before quiescing | |
258 | * which is done by blk_mq_quiesce_queue. | |
259 | */ | |
260 | void blk_mq_unquiesce_queue(struct request_queue *q) | |
261 | { | |
8814ce8a | 262 | blk_queue_flag_clear(QUEUE_FLAG_QUIESCED, q); |
f4560ffe | 263 | |
1d9e9bc6 ML |
264 | /* dispatch requests which are inserted during quiescing */ |
265 | blk_mq_run_hw_queues(q, true); | |
e4e73913 ML |
266 | } |
267 | EXPORT_SYMBOL_GPL(blk_mq_unquiesce_queue); | |
268 | ||
aed3ea94 JA |
269 | void blk_mq_wake_waiters(struct request_queue *q) |
270 | { | |
271 | struct blk_mq_hw_ctx *hctx; | |
272 | unsigned int i; | |
273 | ||
274 | queue_for_each_hw_ctx(q, hctx, i) | |
275 | if (blk_mq_hw_queue_mapped(hctx)) | |
276 | blk_mq_tag_wakeup_all(hctx->tags, true); | |
277 | } | |
278 | ||
320ae51f JA |
279 | bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx) |
280 | { | |
281 | return blk_mq_has_free_tags(hctx->tags); | |
282 | } | |
283 | EXPORT_SYMBOL(blk_mq_can_queue); | |
284 | ||
fe1f4526 | 285 | /* |
9a91b05b HT |
286 | * Only need start/end time stamping if we have iostat or |
287 | * blk stats enabled, or using an IO scheduler. | |
fe1f4526 JA |
288 | */ |
289 | static inline bool blk_mq_need_time_stamp(struct request *rq) | |
290 | { | |
9a91b05b | 291 | return (rq->rq_flags & (RQF_IO_STAT | RQF_STATS)) || rq->q->elevator; |
fe1f4526 JA |
292 | } |
293 | ||
e4cdf1a1 | 294 | static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data, |
6f816b4b | 295 | unsigned int tag, unsigned int op, u64 alloc_time_ns) |
320ae51f | 296 | { |
e4cdf1a1 CH |
297 | struct blk_mq_tags *tags = blk_mq_tags_from_data(data); |
298 | struct request *rq = tags->static_rqs[tag]; | |
bf9ae8c5 | 299 | req_flags_t rq_flags = 0; |
c3a148d2 | 300 | |
e4cdf1a1 CH |
301 | if (data->flags & BLK_MQ_REQ_INTERNAL) { |
302 | rq->tag = -1; | |
303 | rq->internal_tag = tag; | |
304 | } else { | |
d263ed99 | 305 | if (data->hctx->flags & BLK_MQ_F_TAG_SHARED) { |
bf9ae8c5 | 306 | rq_flags = RQF_MQ_INFLIGHT; |
e4cdf1a1 CH |
307 | atomic_inc(&data->hctx->nr_active); |
308 | } | |
309 | rq->tag = tag; | |
310 | rq->internal_tag = -1; | |
311 | data->hctx->tags->rqs[rq->tag] = rq; | |
312 | } | |
313 | ||
af76e555 | 314 | /* csd/requeue_work/fifo_time is initialized before use */ |
e4cdf1a1 CH |
315 | rq->q = data->q; |
316 | rq->mq_ctx = data->ctx; | |
ea4f995e | 317 | rq->mq_hctx = data->hctx; |
bf9ae8c5 | 318 | rq->rq_flags = rq_flags; |
ef295ecf | 319 | rq->cmd_flags = op; |
1b6d65a0 BVA |
320 | if (data->flags & BLK_MQ_REQ_PREEMPT) |
321 | rq->rq_flags |= RQF_PREEMPT; | |
e4cdf1a1 | 322 | if (blk_queue_io_stat(data->q)) |
e8064021 | 323 | rq->rq_flags |= RQF_IO_STAT; |
7c3fb70f | 324 | INIT_LIST_HEAD(&rq->queuelist); |
af76e555 CH |
325 | INIT_HLIST_NODE(&rq->hash); |
326 | RB_CLEAR_NODE(&rq->rb_node); | |
af76e555 CH |
327 | rq->rq_disk = NULL; |
328 | rq->part = NULL; | |
6f816b4b TH |
329 | #ifdef CONFIG_BLK_RQ_ALLOC_TIME |
330 | rq->alloc_time_ns = alloc_time_ns; | |
331 | #endif | |
fe1f4526 JA |
332 | if (blk_mq_need_time_stamp(rq)) |
333 | rq->start_time_ns = ktime_get_ns(); | |
334 | else | |
335 | rq->start_time_ns = 0; | |
544ccc8d | 336 | rq->io_start_time_ns = 0; |
3d244306 | 337 | rq->stats_sectors = 0; |
af76e555 CH |
338 | rq->nr_phys_segments = 0; |
339 | #if defined(CONFIG_BLK_DEV_INTEGRITY) | |
340 | rq->nr_integrity_segments = 0; | |
341 | #endif | |
af76e555 | 342 | /* tag was already set */ |
af76e555 | 343 | rq->extra_len = 0; |
079076b3 | 344 | WRITE_ONCE(rq->deadline, 0); |
af76e555 | 345 | |
f6be4fb4 JA |
346 | rq->timeout = 0; |
347 | ||
af76e555 CH |
348 | rq->end_io = NULL; |
349 | rq->end_io_data = NULL; | |
af76e555 | 350 | |
e4cdf1a1 | 351 | data->ctx->rq_dispatched[op_is_sync(op)]++; |
12f5b931 | 352 | refcount_set(&rq->ref, 1); |
e4cdf1a1 | 353 | return rq; |
5dee8577 CH |
354 | } |
355 | ||
d2c0d383 | 356 | static struct request *blk_mq_get_request(struct request_queue *q, |
f9afca4d JA |
357 | struct bio *bio, |
358 | struct blk_mq_alloc_data *data) | |
d2c0d383 CH |
359 | { |
360 | struct elevator_queue *e = q->elevator; | |
361 | struct request *rq; | |
e4cdf1a1 | 362 | unsigned int tag; |
c05f4220 | 363 | bool clear_ctx_on_error = false; |
6f816b4b | 364 | u64 alloc_time_ns = 0; |
d2c0d383 CH |
365 | |
366 | blk_queue_enter_live(q); | |
6f816b4b TH |
367 | |
368 | /* alloc_time includes depth and tag waits */ | |
369 | if (blk_queue_rq_alloc_time(q)) | |
370 | alloc_time_ns = ktime_get_ns(); | |
371 | ||
d2c0d383 | 372 | data->q = q; |
21e768b4 BVA |
373 | if (likely(!data->ctx)) { |
374 | data->ctx = blk_mq_get_ctx(q); | |
c05f4220 | 375 | clear_ctx_on_error = true; |
21e768b4 | 376 | } |
d2c0d383 | 377 | if (likely(!data->hctx)) |
f9afca4d | 378 | data->hctx = blk_mq_map_queue(q, data->cmd_flags, |
8ccdf4a3 | 379 | data->ctx); |
f9afca4d | 380 | if (data->cmd_flags & REQ_NOWAIT) |
03a07c92 | 381 | data->flags |= BLK_MQ_REQ_NOWAIT; |
d2c0d383 CH |
382 | |
383 | if (e) { | |
384 | data->flags |= BLK_MQ_REQ_INTERNAL; | |
385 | ||
386 | /* | |
387 | * Flush requests are special and go directly to the | |
17a51199 JA |
388 | * dispatch list. Don't include reserved tags in the |
389 | * limiting, as it isn't useful. | |
d2c0d383 | 390 | */ |
f9afca4d JA |
391 | if (!op_is_flush(data->cmd_flags) && |
392 | e->type->ops.limit_depth && | |
17a51199 | 393 | !(data->flags & BLK_MQ_REQ_RESERVED)) |
f9afca4d | 394 | e->type->ops.limit_depth(data->cmd_flags, data); |
d263ed99 JW |
395 | } else { |
396 | blk_mq_tag_busy(data->hctx); | |
d2c0d383 CH |
397 | } |
398 | ||
e4cdf1a1 CH |
399 | tag = blk_mq_get_tag(data); |
400 | if (tag == BLK_MQ_TAG_FAIL) { | |
c05f4220 | 401 | if (clear_ctx_on_error) |
1ad43c00 | 402 | data->ctx = NULL; |
037cebb8 CH |
403 | blk_queue_exit(q); |
404 | return NULL; | |
d2c0d383 CH |
405 | } |
406 | ||
6f816b4b | 407 | rq = blk_mq_rq_ctx_init(data, tag, data->cmd_flags, alloc_time_ns); |
f9afca4d | 408 | if (!op_is_flush(data->cmd_flags)) { |
037cebb8 | 409 | rq->elv.icq = NULL; |
f9cd4bfe | 410 | if (e && e->type->ops.prepare_request) { |
e2b3fa5a DLM |
411 | if (e->type->icq_cache) |
412 | blk_mq_sched_assign_ioc(rq); | |
44e8c2bf | 413 | |
f9cd4bfe | 414 | e->type->ops.prepare_request(rq, bio); |
5bbf4e5a | 415 | rq->rq_flags |= RQF_ELVPRIV; |
44e8c2bf | 416 | } |
037cebb8 CH |
417 | } |
418 | data->hctx->queued++; | |
419 | return rq; | |
d2c0d383 CH |
420 | } |
421 | ||
cd6ce148 | 422 | struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op, |
9a95e4ef | 423 | blk_mq_req_flags_t flags) |
320ae51f | 424 | { |
f9afca4d | 425 | struct blk_mq_alloc_data alloc_data = { .flags = flags, .cmd_flags = op }; |
bd166ef1 | 426 | struct request *rq; |
a492f075 | 427 | int ret; |
320ae51f | 428 | |
3a0a5299 | 429 | ret = blk_queue_enter(q, flags); |
a492f075 JL |
430 | if (ret) |
431 | return ERR_PTR(ret); | |
320ae51f | 432 | |
f9afca4d | 433 | rq = blk_mq_get_request(q, NULL, &alloc_data); |
3280d66a | 434 | blk_queue_exit(q); |
841bac2c | 435 | |
bd166ef1 | 436 | if (!rq) |
a492f075 | 437 | return ERR_PTR(-EWOULDBLOCK); |
0c4de0f3 CH |
438 | |
439 | rq->__data_len = 0; | |
440 | rq->__sector = (sector_t) -1; | |
441 | rq->bio = rq->biotail = NULL; | |
320ae51f JA |
442 | return rq; |
443 | } | |
4bb659b1 | 444 | EXPORT_SYMBOL(blk_mq_alloc_request); |
320ae51f | 445 | |
cd6ce148 | 446 | struct request *blk_mq_alloc_request_hctx(struct request_queue *q, |
9a95e4ef | 447 | unsigned int op, blk_mq_req_flags_t flags, unsigned int hctx_idx) |
1f5bd336 | 448 | { |
f9afca4d | 449 | struct blk_mq_alloc_data alloc_data = { .flags = flags, .cmd_flags = op }; |
1f5bd336 | 450 | struct request *rq; |
6d2809d5 | 451 | unsigned int cpu; |
1f5bd336 ML |
452 | int ret; |
453 | ||
454 | /* | |
455 | * If the tag allocator sleeps we could get an allocation for a | |
456 | * different hardware context. No need to complicate the low level | |
457 | * allocator for this for the rare use case of a command tied to | |
458 | * a specific queue. | |
459 | */ | |
460 | if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT))) | |
461 | return ERR_PTR(-EINVAL); | |
462 | ||
463 | if (hctx_idx >= q->nr_hw_queues) | |
464 | return ERR_PTR(-EIO); | |
465 | ||
3a0a5299 | 466 | ret = blk_queue_enter(q, flags); |
1f5bd336 ML |
467 | if (ret) |
468 | return ERR_PTR(ret); | |
469 | ||
c8712c6a CH |
470 | /* |
471 | * Check if the hardware context is actually mapped to anything. | |
472 | * If not tell the caller that it should skip this queue. | |
473 | */ | |
6d2809d5 OS |
474 | alloc_data.hctx = q->queue_hw_ctx[hctx_idx]; |
475 | if (!blk_mq_hw_queue_mapped(alloc_data.hctx)) { | |
476 | blk_queue_exit(q); | |
477 | return ERR_PTR(-EXDEV); | |
c8712c6a | 478 | } |
20e4d813 | 479 | cpu = cpumask_first_and(alloc_data.hctx->cpumask, cpu_online_mask); |
6d2809d5 | 480 | alloc_data.ctx = __blk_mq_get_ctx(q, cpu); |
1f5bd336 | 481 | |
f9afca4d | 482 | rq = blk_mq_get_request(q, NULL, &alloc_data); |
3280d66a | 483 | blk_queue_exit(q); |
c8712c6a | 484 | |
6d2809d5 OS |
485 | if (!rq) |
486 | return ERR_PTR(-EWOULDBLOCK); | |
487 | ||
488 | return rq; | |
1f5bd336 ML |
489 | } |
490 | EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx); | |
491 | ||
12f5b931 KB |
492 | static void __blk_mq_free_request(struct request *rq) |
493 | { | |
494 | struct request_queue *q = rq->q; | |
495 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
ea4f995e | 496 | struct blk_mq_hw_ctx *hctx = rq->mq_hctx; |
12f5b931 KB |
497 | const int sched_tag = rq->internal_tag; |
498 | ||
986d413b | 499 | blk_pm_mark_last_busy(rq); |
ea4f995e | 500 | rq->mq_hctx = NULL; |
12f5b931 KB |
501 | if (rq->tag != -1) |
502 | blk_mq_put_tag(hctx, hctx->tags, ctx, rq->tag); | |
503 | if (sched_tag != -1) | |
504 | blk_mq_put_tag(hctx, hctx->sched_tags, ctx, sched_tag); | |
505 | blk_mq_sched_restart(hctx); | |
506 | blk_queue_exit(q); | |
507 | } | |
508 | ||
6af54051 | 509 | void blk_mq_free_request(struct request *rq) |
320ae51f | 510 | { |
320ae51f | 511 | struct request_queue *q = rq->q; |
6af54051 CH |
512 | struct elevator_queue *e = q->elevator; |
513 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
ea4f995e | 514 | struct blk_mq_hw_ctx *hctx = rq->mq_hctx; |
6af54051 | 515 | |
5bbf4e5a | 516 | if (rq->rq_flags & RQF_ELVPRIV) { |
f9cd4bfe JA |
517 | if (e && e->type->ops.finish_request) |
518 | e->type->ops.finish_request(rq); | |
6af54051 CH |
519 | if (rq->elv.icq) { |
520 | put_io_context(rq->elv.icq->ioc); | |
521 | rq->elv.icq = NULL; | |
522 | } | |
523 | } | |
320ae51f | 524 | |
6af54051 | 525 | ctx->rq_completed[rq_is_sync(rq)]++; |
e8064021 | 526 | if (rq->rq_flags & RQF_MQ_INFLIGHT) |
0d2602ca | 527 | atomic_dec(&hctx->nr_active); |
87760e5e | 528 | |
7beb2f84 JA |
529 | if (unlikely(laptop_mode && !blk_rq_is_passthrough(rq))) |
530 | laptop_io_completion(q->backing_dev_info); | |
531 | ||
a7905043 | 532 | rq_qos_done(q, rq); |
0d2602ca | 533 | |
12f5b931 KB |
534 | WRITE_ONCE(rq->state, MQ_RQ_IDLE); |
535 | if (refcount_dec_and_test(&rq->ref)) | |
536 | __blk_mq_free_request(rq); | |
320ae51f | 537 | } |
1a3b595a | 538 | EXPORT_SYMBOL_GPL(blk_mq_free_request); |
320ae51f | 539 | |
2a842aca | 540 | inline void __blk_mq_end_request(struct request *rq, blk_status_t error) |
320ae51f | 541 | { |
fe1f4526 JA |
542 | u64 now = 0; |
543 | ||
544 | if (blk_mq_need_time_stamp(rq)) | |
545 | now = ktime_get_ns(); | |
522a7775 | 546 | |
4bc6339a OS |
547 | if (rq->rq_flags & RQF_STATS) { |
548 | blk_mq_poll_stats_start(rq->q); | |
522a7775 | 549 | blk_stat_add(rq, now); |
4bc6339a OS |
550 | } |
551 | ||
ed88660a OS |
552 | if (rq->internal_tag != -1) |
553 | blk_mq_sched_completed_request(rq, now); | |
554 | ||
522a7775 | 555 | blk_account_io_done(rq, now); |
0d11e6ac | 556 | |
91b63639 | 557 | if (rq->end_io) { |
a7905043 | 558 | rq_qos_done(rq->q, rq); |
320ae51f | 559 | rq->end_io(rq, error); |
91b63639 | 560 | } else { |
320ae51f | 561 | blk_mq_free_request(rq); |
91b63639 | 562 | } |
320ae51f | 563 | } |
c8a446ad | 564 | EXPORT_SYMBOL(__blk_mq_end_request); |
63151a44 | 565 | |
2a842aca | 566 | void blk_mq_end_request(struct request *rq, blk_status_t error) |
63151a44 CH |
567 | { |
568 | if (blk_update_request(rq, error, blk_rq_bytes(rq))) | |
569 | BUG(); | |
c8a446ad | 570 | __blk_mq_end_request(rq, error); |
63151a44 | 571 | } |
c8a446ad | 572 | EXPORT_SYMBOL(blk_mq_end_request); |
320ae51f | 573 | |
30a91cb4 | 574 | static void __blk_mq_complete_request_remote(void *data) |
320ae51f | 575 | { |
3d6efbf6 | 576 | struct request *rq = data; |
c7bb9ad1 | 577 | struct request_queue *q = rq->q; |
320ae51f | 578 | |
c7bb9ad1 | 579 | q->mq_ops->complete(rq); |
320ae51f | 580 | } |
320ae51f | 581 | |
453f8341 | 582 | static void __blk_mq_complete_request(struct request *rq) |
320ae51f JA |
583 | { |
584 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
c7bb9ad1 | 585 | struct request_queue *q = rq->q; |
38535201 | 586 | bool shared = false; |
320ae51f JA |
587 | int cpu; |
588 | ||
af78ff7c | 589 | WRITE_ONCE(rq->state, MQ_RQ_COMPLETE); |
36e76539 ML |
590 | /* |
591 | * Most of single queue controllers, there is only one irq vector | |
592 | * for handling IO completion, and the only irq's affinity is set | |
593 | * as all possible CPUs. On most of ARCHs, this affinity means the | |
594 | * irq is handled on one specific CPU. | |
595 | * | |
596 | * So complete IO reqeust in softirq context in case of single queue | |
597 | * for not degrading IO performance by irqsoff latency. | |
598 | */ | |
c7bb9ad1 | 599 | if (q->nr_hw_queues == 1) { |
36e76539 ML |
600 | __blk_complete_request(rq); |
601 | return; | |
602 | } | |
603 | ||
4ab32bf3 JA |
604 | /* |
605 | * For a polled request, always complete locallly, it's pointless | |
606 | * to redirect the completion. | |
607 | */ | |
608 | if ((rq->cmd_flags & REQ_HIPRI) || | |
609 | !test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags)) { | |
c7bb9ad1 | 610 | q->mq_ops->complete(rq); |
30a91cb4 CH |
611 | return; |
612 | } | |
320ae51f JA |
613 | |
614 | cpu = get_cpu(); | |
c7bb9ad1 | 615 | if (!test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags)) |
38535201 CH |
616 | shared = cpus_share_cache(cpu, ctx->cpu); |
617 | ||
618 | if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) { | |
30a91cb4 | 619 | rq->csd.func = __blk_mq_complete_request_remote; |
3d6efbf6 CH |
620 | rq->csd.info = rq; |
621 | rq->csd.flags = 0; | |
c46fff2a | 622 | smp_call_function_single_async(ctx->cpu, &rq->csd); |
3d6efbf6 | 623 | } else { |
c7bb9ad1 | 624 | q->mq_ops->complete(rq); |
3d6efbf6 | 625 | } |
320ae51f JA |
626 | put_cpu(); |
627 | } | |
30a91cb4 | 628 | |
04ced159 | 629 | static void hctx_unlock(struct blk_mq_hw_ctx *hctx, int srcu_idx) |
b7435db8 | 630 | __releases(hctx->srcu) |
04ced159 JA |
631 | { |
632 | if (!(hctx->flags & BLK_MQ_F_BLOCKING)) | |
633 | rcu_read_unlock(); | |
634 | else | |
05707b64 | 635 | srcu_read_unlock(hctx->srcu, srcu_idx); |
04ced159 JA |
636 | } |
637 | ||
638 | static void hctx_lock(struct blk_mq_hw_ctx *hctx, int *srcu_idx) | |
b7435db8 | 639 | __acquires(hctx->srcu) |
04ced159 | 640 | { |
08b5a6e2 JA |
641 | if (!(hctx->flags & BLK_MQ_F_BLOCKING)) { |
642 | /* shut up gcc false positive */ | |
643 | *srcu_idx = 0; | |
04ced159 | 644 | rcu_read_lock(); |
08b5a6e2 | 645 | } else |
05707b64 | 646 | *srcu_idx = srcu_read_lock(hctx->srcu); |
04ced159 JA |
647 | } |
648 | ||
30a91cb4 CH |
649 | /** |
650 | * blk_mq_complete_request - end I/O on a request | |
651 | * @rq: the request being processed | |
652 | * | |
653 | * Description: | |
654 | * Ends all I/O on a request. It does not handle partial completions. | |
655 | * The actual completion happens out-of-order, through a IPI handler. | |
656 | **/ | |
16c15eb1 | 657 | bool blk_mq_complete_request(struct request *rq) |
30a91cb4 | 658 | { |
12f5b931 | 659 | if (unlikely(blk_should_fake_timeout(rq->q))) |
16c15eb1 | 660 | return false; |
12f5b931 | 661 | __blk_mq_complete_request(rq); |
16c15eb1 | 662 | return true; |
30a91cb4 CH |
663 | } |
664 | EXPORT_SYMBOL(blk_mq_complete_request); | |
320ae51f | 665 | |
973c0191 KB |
666 | int blk_mq_request_started(struct request *rq) |
667 | { | |
5a61c363 | 668 | return blk_mq_rq_state(rq) != MQ_RQ_IDLE; |
973c0191 KB |
669 | } |
670 | EXPORT_SYMBOL_GPL(blk_mq_request_started); | |
671 | ||
aa306ab7 ML |
672 | int blk_mq_request_completed(struct request *rq) |
673 | { | |
674 | return blk_mq_rq_state(rq) == MQ_RQ_COMPLETE; | |
675 | } | |
676 | EXPORT_SYMBOL_GPL(blk_mq_request_completed); | |
677 | ||
e2490073 | 678 | void blk_mq_start_request(struct request *rq) |
320ae51f JA |
679 | { |
680 | struct request_queue *q = rq->q; | |
681 | ||
682 | trace_block_rq_issue(q, rq); | |
683 | ||
cf43e6be | 684 | if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags)) { |
544ccc8d | 685 | rq->io_start_time_ns = ktime_get_ns(); |
3d244306 | 686 | rq->stats_sectors = blk_rq_sectors(rq); |
cf43e6be | 687 | rq->rq_flags |= RQF_STATS; |
a7905043 | 688 | rq_qos_issue(q, rq); |
cf43e6be JA |
689 | } |
690 | ||
1d9bd516 | 691 | WARN_ON_ONCE(blk_mq_rq_state(rq) != MQ_RQ_IDLE); |
538b7534 | 692 | |
1d9bd516 | 693 | blk_add_timer(rq); |
12f5b931 | 694 | WRITE_ONCE(rq->state, MQ_RQ_IN_FLIGHT); |
49f5baa5 CH |
695 | |
696 | if (q->dma_drain_size && blk_rq_bytes(rq)) { | |
697 | /* | |
698 | * Make sure space for the drain appears. We know we can do | |
699 | * this because max_hw_segments has been adjusted to be one | |
700 | * fewer than the device can handle. | |
701 | */ | |
702 | rq->nr_phys_segments++; | |
703 | } | |
54d4e6ab MG |
704 | |
705 | #ifdef CONFIG_BLK_DEV_INTEGRITY | |
706 | if (blk_integrity_rq(rq) && req_op(rq) == REQ_OP_WRITE) | |
707 | q->integrity.profile->prepare_fn(rq); | |
708 | #endif | |
320ae51f | 709 | } |
e2490073 | 710 | EXPORT_SYMBOL(blk_mq_start_request); |
320ae51f | 711 | |
ed0791b2 | 712 | static void __blk_mq_requeue_request(struct request *rq) |
320ae51f JA |
713 | { |
714 | struct request_queue *q = rq->q; | |
715 | ||
923218f6 ML |
716 | blk_mq_put_driver_tag(rq); |
717 | ||
320ae51f | 718 | trace_block_rq_requeue(q, rq); |
a7905043 | 719 | rq_qos_requeue(q, rq); |
49f5baa5 | 720 | |
12f5b931 KB |
721 | if (blk_mq_request_started(rq)) { |
722 | WRITE_ONCE(rq->state, MQ_RQ_IDLE); | |
da661267 | 723 | rq->rq_flags &= ~RQF_TIMED_OUT; |
e2490073 CH |
724 | if (q->dma_drain_size && blk_rq_bytes(rq)) |
725 | rq->nr_phys_segments--; | |
726 | } | |
320ae51f JA |
727 | } |
728 | ||
2b053aca | 729 | void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list) |
ed0791b2 | 730 | { |
ed0791b2 | 731 | __blk_mq_requeue_request(rq); |
ed0791b2 | 732 | |
105976f5 ML |
733 | /* this request will be re-inserted to io scheduler queue */ |
734 | blk_mq_sched_requeue_request(rq); | |
735 | ||
7d692330 | 736 | BUG_ON(!list_empty(&rq->queuelist)); |
2b053aca | 737 | blk_mq_add_to_requeue_list(rq, true, kick_requeue_list); |
ed0791b2 CH |
738 | } |
739 | EXPORT_SYMBOL(blk_mq_requeue_request); | |
740 | ||
6fca6a61 CH |
741 | static void blk_mq_requeue_work(struct work_struct *work) |
742 | { | |
743 | struct request_queue *q = | |
2849450a | 744 | container_of(work, struct request_queue, requeue_work.work); |
6fca6a61 CH |
745 | LIST_HEAD(rq_list); |
746 | struct request *rq, *next; | |
6fca6a61 | 747 | |
18e9781d | 748 | spin_lock_irq(&q->requeue_lock); |
6fca6a61 | 749 | list_splice_init(&q->requeue_list, &rq_list); |
18e9781d | 750 | spin_unlock_irq(&q->requeue_lock); |
6fca6a61 CH |
751 | |
752 | list_for_each_entry_safe(rq, next, &rq_list, queuelist) { | |
aef1897c | 753 | if (!(rq->rq_flags & (RQF_SOFTBARRIER | RQF_DONTPREP))) |
6fca6a61 CH |
754 | continue; |
755 | ||
e8064021 | 756 | rq->rq_flags &= ~RQF_SOFTBARRIER; |
6fca6a61 | 757 | list_del_init(&rq->queuelist); |
aef1897c JW |
758 | /* |
759 | * If RQF_DONTPREP, rq has contained some driver specific | |
760 | * data, so insert it to hctx dispatch list to avoid any | |
761 | * merge. | |
762 | */ | |
763 | if (rq->rq_flags & RQF_DONTPREP) | |
9520af16 | 764 | blk_mq_request_bypass_insert(rq, false, false); |
aef1897c JW |
765 | else |
766 | blk_mq_sched_insert_request(rq, true, false, false); | |
6fca6a61 CH |
767 | } |
768 | ||
769 | while (!list_empty(&rq_list)) { | |
770 | rq = list_entry(rq_list.next, struct request, queuelist); | |
771 | list_del_init(&rq->queuelist); | |
9e97d295 | 772 | blk_mq_sched_insert_request(rq, false, false, false); |
6fca6a61 CH |
773 | } |
774 | ||
52d7f1b5 | 775 | blk_mq_run_hw_queues(q, false); |
6fca6a61 CH |
776 | } |
777 | ||
2b053aca BVA |
778 | void blk_mq_add_to_requeue_list(struct request *rq, bool at_head, |
779 | bool kick_requeue_list) | |
6fca6a61 CH |
780 | { |
781 | struct request_queue *q = rq->q; | |
782 | unsigned long flags; | |
783 | ||
784 | /* | |
785 | * We abuse this flag that is otherwise used by the I/O scheduler to | |
ff821d27 | 786 | * request head insertion from the workqueue. |
6fca6a61 | 787 | */ |
e8064021 | 788 | BUG_ON(rq->rq_flags & RQF_SOFTBARRIER); |
6fca6a61 CH |
789 | |
790 | spin_lock_irqsave(&q->requeue_lock, flags); | |
791 | if (at_head) { | |
e8064021 | 792 | rq->rq_flags |= RQF_SOFTBARRIER; |
6fca6a61 CH |
793 | list_add(&rq->queuelist, &q->requeue_list); |
794 | } else { | |
795 | list_add_tail(&rq->queuelist, &q->requeue_list); | |
796 | } | |
797 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
2b053aca BVA |
798 | |
799 | if (kick_requeue_list) | |
800 | blk_mq_kick_requeue_list(q); | |
6fca6a61 | 801 | } |
6fca6a61 CH |
802 | |
803 | void blk_mq_kick_requeue_list(struct request_queue *q) | |
804 | { | |
ae943d20 | 805 | kblockd_mod_delayed_work_on(WORK_CPU_UNBOUND, &q->requeue_work, 0); |
6fca6a61 CH |
806 | } |
807 | EXPORT_SYMBOL(blk_mq_kick_requeue_list); | |
808 | ||
2849450a MS |
809 | void blk_mq_delay_kick_requeue_list(struct request_queue *q, |
810 | unsigned long msecs) | |
811 | { | |
d4acf365 BVA |
812 | kblockd_mod_delayed_work_on(WORK_CPU_UNBOUND, &q->requeue_work, |
813 | msecs_to_jiffies(msecs)); | |
2849450a MS |
814 | } |
815 | EXPORT_SYMBOL(blk_mq_delay_kick_requeue_list); | |
816 | ||
0e62f51f JA |
817 | struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag) |
818 | { | |
88c7b2b7 JA |
819 | if (tag < tags->nr_tags) { |
820 | prefetch(tags->rqs[tag]); | |
4ee86bab | 821 | return tags->rqs[tag]; |
88c7b2b7 | 822 | } |
4ee86bab HR |
823 | |
824 | return NULL; | |
24d2f903 CH |
825 | } |
826 | EXPORT_SYMBOL(blk_mq_tag_to_rq); | |
827 | ||
3c94d83c JA |
828 | static bool blk_mq_rq_inflight(struct blk_mq_hw_ctx *hctx, struct request *rq, |
829 | void *priv, bool reserved) | |
ae879912 JA |
830 | { |
831 | /* | |
3c94d83c JA |
832 | * If we find a request that is inflight and the queue matches, |
833 | * we know the queue is busy. Return false to stop the iteration. | |
ae879912 | 834 | */ |
3c94d83c | 835 | if (rq->state == MQ_RQ_IN_FLIGHT && rq->q == hctx->queue) { |
ae879912 JA |
836 | bool *busy = priv; |
837 | ||
838 | *busy = true; | |
839 | return false; | |
840 | } | |
841 | ||
842 | return true; | |
843 | } | |
844 | ||
3c94d83c | 845 | bool blk_mq_queue_inflight(struct request_queue *q) |
ae879912 JA |
846 | { |
847 | bool busy = false; | |
848 | ||
3c94d83c | 849 | blk_mq_queue_tag_busy_iter(q, blk_mq_rq_inflight, &busy); |
ae879912 JA |
850 | return busy; |
851 | } | |
3c94d83c | 852 | EXPORT_SYMBOL_GPL(blk_mq_queue_inflight); |
ae879912 | 853 | |
358f70da | 854 | static void blk_mq_rq_timed_out(struct request *req, bool reserved) |
320ae51f | 855 | { |
da661267 | 856 | req->rq_flags |= RQF_TIMED_OUT; |
d1210d5a CH |
857 | if (req->q->mq_ops->timeout) { |
858 | enum blk_eh_timer_return ret; | |
859 | ||
860 | ret = req->q->mq_ops->timeout(req, reserved); | |
861 | if (ret == BLK_EH_DONE) | |
862 | return; | |
863 | WARN_ON_ONCE(ret != BLK_EH_RESET_TIMER); | |
46f92d42 | 864 | } |
d1210d5a CH |
865 | |
866 | blk_add_timer(req); | |
87ee7b11 | 867 | } |
5b3f25fc | 868 | |
12f5b931 | 869 | static bool blk_mq_req_expired(struct request *rq, unsigned long *next) |
81481eb4 | 870 | { |
12f5b931 | 871 | unsigned long deadline; |
87ee7b11 | 872 | |
12f5b931 KB |
873 | if (blk_mq_rq_state(rq) != MQ_RQ_IN_FLIGHT) |
874 | return false; | |
da661267 CH |
875 | if (rq->rq_flags & RQF_TIMED_OUT) |
876 | return false; | |
a7af0af3 | 877 | |
079076b3 | 878 | deadline = READ_ONCE(rq->deadline); |
12f5b931 KB |
879 | if (time_after_eq(jiffies, deadline)) |
880 | return true; | |
a7af0af3 | 881 | |
12f5b931 KB |
882 | if (*next == 0) |
883 | *next = deadline; | |
884 | else if (time_after(*next, deadline)) | |
885 | *next = deadline; | |
886 | return false; | |
87ee7b11 JA |
887 | } |
888 | ||
7baa8572 | 889 | static bool blk_mq_check_expired(struct blk_mq_hw_ctx *hctx, |
1d9bd516 TH |
890 | struct request *rq, void *priv, bool reserved) |
891 | { | |
12f5b931 KB |
892 | unsigned long *next = priv; |
893 | ||
894 | /* | |
895 | * Just do a quick check if it is expired before locking the request in | |
896 | * so we're not unnecessarilly synchronizing across CPUs. | |
897 | */ | |
898 | if (!blk_mq_req_expired(rq, next)) | |
7baa8572 | 899 | return true; |
12f5b931 KB |
900 | |
901 | /* | |
902 | * We have reason to believe the request may be expired. Take a | |
903 | * reference on the request to lock this request lifetime into its | |
904 | * currently allocated context to prevent it from being reallocated in | |
905 | * the event the completion by-passes this timeout handler. | |
906 | * | |
907 | * If the reference was already released, then the driver beat the | |
908 | * timeout handler to posting a natural completion. | |
909 | */ | |
910 | if (!refcount_inc_not_zero(&rq->ref)) | |
7baa8572 | 911 | return true; |
12f5b931 | 912 | |
1d9bd516 | 913 | /* |
12f5b931 KB |
914 | * The request is now locked and cannot be reallocated underneath the |
915 | * timeout handler's processing. Re-verify this exact request is truly | |
916 | * expired; if it is not expired, then the request was completed and | |
917 | * reallocated as a new request. | |
1d9bd516 | 918 | */ |
12f5b931 | 919 | if (blk_mq_req_expired(rq, next)) |
1d9bd516 | 920 | blk_mq_rq_timed_out(rq, reserved); |
8d699663 YY |
921 | |
922 | if (is_flush_rq(rq, hctx)) | |
923 | rq->end_io(rq, 0); | |
924 | else if (refcount_dec_and_test(&rq->ref)) | |
12f5b931 | 925 | __blk_mq_free_request(rq); |
7baa8572 JA |
926 | |
927 | return true; | |
1d9bd516 TH |
928 | } |
929 | ||
287922eb | 930 | static void blk_mq_timeout_work(struct work_struct *work) |
320ae51f | 931 | { |
287922eb CH |
932 | struct request_queue *q = |
933 | container_of(work, struct request_queue, timeout_work); | |
12f5b931 | 934 | unsigned long next = 0; |
1d9bd516 | 935 | struct blk_mq_hw_ctx *hctx; |
81481eb4 | 936 | int i; |
320ae51f | 937 | |
71f79fb3 GKB |
938 | /* A deadlock might occur if a request is stuck requiring a |
939 | * timeout at the same time a queue freeze is waiting | |
940 | * completion, since the timeout code would not be able to | |
941 | * acquire the queue reference here. | |
942 | * | |
943 | * That's why we don't use blk_queue_enter here; instead, we use | |
944 | * percpu_ref_tryget directly, because we need to be able to | |
945 | * obtain a reference even in the short window between the queue | |
946 | * starting to freeze, by dropping the first reference in | |
1671d522 | 947 | * blk_freeze_queue_start, and the moment the last request is |
71f79fb3 GKB |
948 | * consumed, marked by the instant q_usage_counter reaches |
949 | * zero. | |
950 | */ | |
951 | if (!percpu_ref_tryget(&q->q_usage_counter)) | |
287922eb CH |
952 | return; |
953 | ||
12f5b931 | 954 | blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &next); |
320ae51f | 955 | |
12f5b931 KB |
956 | if (next != 0) { |
957 | mod_timer(&q->timeout, next); | |
0d2602ca | 958 | } else { |
fcd36c36 BVA |
959 | /* |
960 | * Request timeouts are handled as a forward rolling timer. If | |
961 | * we end up here it means that no requests are pending and | |
962 | * also that no request has been pending for a while. Mark | |
963 | * each hctx as idle. | |
964 | */ | |
f054b56c ML |
965 | queue_for_each_hw_ctx(q, hctx, i) { |
966 | /* the hctx may be unmapped, so check it here */ | |
967 | if (blk_mq_hw_queue_mapped(hctx)) | |
968 | blk_mq_tag_idle(hctx); | |
969 | } | |
0d2602ca | 970 | } |
287922eb | 971 | blk_queue_exit(q); |
320ae51f JA |
972 | } |
973 | ||
88459642 OS |
974 | struct flush_busy_ctx_data { |
975 | struct blk_mq_hw_ctx *hctx; | |
976 | struct list_head *list; | |
977 | }; | |
978 | ||
979 | static bool flush_busy_ctx(struct sbitmap *sb, unsigned int bitnr, void *data) | |
980 | { | |
981 | struct flush_busy_ctx_data *flush_data = data; | |
982 | struct blk_mq_hw_ctx *hctx = flush_data->hctx; | |
983 | struct blk_mq_ctx *ctx = hctx->ctxs[bitnr]; | |
c16d6b5a | 984 | enum hctx_type type = hctx->type; |
88459642 | 985 | |
88459642 | 986 | spin_lock(&ctx->lock); |
c16d6b5a | 987 | list_splice_tail_init(&ctx->rq_lists[type], flush_data->list); |
e9a99a63 | 988 | sbitmap_clear_bit(sb, bitnr); |
88459642 OS |
989 | spin_unlock(&ctx->lock); |
990 | return true; | |
991 | } | |
992 | ||
1429d7c9 JA |
993 | /* |
994 | * Process software queues that have been marked busy, splicing them | |
995 | * to the for-dispatch | |
996 | */ | |
2c3ad667 | 997 | void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) |
1429d7c9 | 998 | { |
88459642 OS |
999 | struct flush_busy_ctx_data data = { |
1000 | .hctx = hctx, | |
1001 | .list = list, | |
1002 | }; | |
1429d7c9 | 1003 | |
88459642 | 1004 | sbitmap_for_each_set(&hctx->ctx_map, flush_busy_ctx, &data); |
1429d7c9 | 1005 | } |
2c3ad667 | 1006 | EXPORT_SYMBOL_GPL(blk_mq_flush_busy_ctxs); |
1429d7c9 | 1007 | |
b347689f ML |
1008 | struct dispatch_rq_data { |
1009 | struct blk_mq_hw_ctx *hctx; | |
1010 | struct request *rq; | |
1011 | }; | |
1012 | ||
1013 | static bool dispatch_rq_from_ctx(struct sbitmap *sb, unsigned int bitnr, | |
1014 | void *data) | |
1015 | { | |
1016 | struct dispatch_rq_data *dispatch_data = data; | |
1017 | struct blk_mq_hw_ctx *hctx = dispatch_data->hctx; | |
1018 | struct blk_mq_ctx *ctx = hctx->ctxs[bitnr]; | |
c16d6b5a | 1019 | enum hctx_type type = hctx->type; |
b347689f ML |
1020 | |
1021 | spin_lock(&ctx->lock); | |
c16d6b5a ML |
1022 | if (!list_empty(&ctx->rq_lists[type])) { |
1023 | dispatch_data->rq = list_entry_rq(ctx->rq_lists[type].next); | |
b347689f | 1024 | list_del_init(&dispatch_data->rq->queuelist); |
c16d6b5a | 1025 | if (list_empty(&ctx->rq_lists[type])) |
b347689f ML |
1026 | sbitmap_clear_bit(sb, bitnr); |
1027 | } | |
1028 | spin_unlock(&ctx->lock); | |
1029 | ||
1030 | return !dispatch_data->rq; | |
1031 | } | |
1032 | ||
1033 | struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx, | |
1034 | struct blk_mq_ctx *start) | |
1035 | { | |
f31967f0 | 1036 | unsigned off = start ? start->index_hw[hctx->type] : 0; |
b347689f ML |
1037 | struct dispatch_rq_data data = { |
1038 | .hctx = hctx, | |
1039 | .rq = NULL, | |
1040 | }; | |
1041 | ||
1042 | __sbitmap_for_each_set(&hctx->ctx_map, off, | |
1043 | dispatch_rq_from_ctx, &data); | |
1044 | ||
1045 | return data.rq; | |
1046 | } | |
1047 | ||
703fd1c0 JA |
1048 | static inline unsigned int queued_to_index(unsigned int queued) |
1049 | { | |
1050 | if (!queued) | |
1051 | return 0; | |
1429d7c9 | 1052 | |
703fd1c0 | 1053 | return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1); |
1429d7c9 JA |
1054 | } |
1055 | ||
8ab6bb9e | 1056 | bool blk_mq_get_driver_tag(struct request *rq) |
bd166ef1 JA |
1057 | { |
1058 | struct blk_mq_alloc_data data = { | |
1059 | .q = rq->q, | |
ea4f995e | 1060 | .hctx = rq->mq_hctx, |
8ab6bb9e | 1061 | .flags = BLK_MQ_REQ_NOWAIT, |
f9afca4d | 1062 | .cmd_flags = rq->cmd_flags, |
bd166ef1 | 1063 | }; |
d263ed99 | 1064 | bool shared; |
5feeacdd | 1065 | |
81380ca1 OS |
1066 | if (rq->tag != -1) |
1067 | goto done; | |
bd166ef1 | 1068 | |
415b806d SG |
1069 | if (blk_mq_tag_is_reserved(data.hctx->sched_tags, rq->internal_tag)) |
1070 | data.flags |= BLK_MQ_REQ_RESERVED; | |
1071 | ||
d263ed99 | 1072 | shared = blk_mq_tag_busy(data.hctx); |
bd166ef1 JA |
1073 | rq->tag = blk_mq_get_tag(&data); |
1074 | if (rq->tag >= 0) { | |
d263ed99 | 1075 | if (shared) { |
200e86b3 JA |
1076 | rq->rq_flags |= RQF_MQ_INFLIGHT; |
1077 | atomic_inc(&data.hctx->nr_active); | |
1078 | } | |
bd166ef1 | 1079 | data.hctx->tags->rqs[rq->tag] = rq; |
bd166ef1 JA |
1080 | } |
1081 | ||
81380ca1 | 1082 | done: |
81380ca1 | 1083 | return rq->tag != -1; |
bd166ef1 JA |
1084 | } |
1085 | ||
eb619fdb JA |
1086 | static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode, |
1087 | int flags, void *key) | |
da55f2cc OS |
1088 | { |
1089 | struct blk_mq_hw_ctx *hctx; | |
1090 | ||
1091 | hctx = container_of(wait, struct blk_mq_hw_ctx, dispatch_wait); | |
1092 | ||
5815839b | 1093 | spin_lock(&hctx->dispatch_wait_lock); |
e8618575 JA |
1094 | if (!list_empty(&wait->entry)) { |
1095 | struct sbitmap_queue *sbq; | |
1096 | ||
1097 | list_del_init(&wait->entry); | |
1098 | sbq = &hctx->tags->bitmap_tags; | |
1099 | atomic_dec(&sbq->ws_active); | |
1100 | } | |
5815839b ML |
1101 | spin_unlock(&hctx->dispatch_wait_lock); |
1102 | ||
da55f2cc OS |
1103 | blk_mq_run_hw_queue(hctx, true); |
1104 | return 1; | |
1105 | } | |
1106 | ||
f906a6a0 JA |
1107 | /* |
1108 | * Mark us waiting for a tag. For shared tags, this involves hooking us into | |
ee3e4de5 BVA |
1109 | * the tag wakeups. For non-shared tags, we can simply mark us needing a |
1110 | * restart. For both cases, take care to check the condition again after | |
f906a6a0 JA |
1111 | * marking us as waiting. |
1112 | */ | |
2278d69f | 1113 | static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx *hctx, |
f906a6a0 | 1114 | struct request *rq) |
da55f2cc | 1115 | { |
e8618575 | 1116 | struct sbitmap_queue *sbq = &hctx->tags->bitmap_tags; |
5815839b | 1117 | struct wait_queue_head *wq; |
f906a6a0 JA |
1118 | wait_queue_entry_t *wait; |
1119 | bool ret; | |
da55f2cc | 1120 | |
2278d69f | 1121 | if (!(hctx->flags & BLK_MQ_F_TAG_SHARED)) { |
684b7324 | 1122 | blk_mq_sched_mark_restart_hctx(hctx); |
f906a6a0 | 1123 | |
c27d53fb BVA |
1124 | /* |
1125 | * It's possible that a tag was freed in the window between the | |
1126 | * allocation failure and adding the hardware queue to the wait | |
1127 | * queue. | |
1128 | * | |
1129 | * Don't clear RESTART here, someone else could have set it. | |
1130 | * At most this will cost an extra queue run. | |
1131 | */ | |
8ab6bb9e | 1132 | return blk_mq_get_driver_tag(rq); |
eb619fdb | 1133 | } |
eb619fdb | 1134 | |
2278d69f | 1135 | wait = &hctx->dispatch_wait; |
c27d53fb BVA |
1136 | if (!list_empty_careful(&wait->entry)) |
1137 | return false; | |
1138 | ||
e8618575 | 1139 | wq = &bt_wait_ptr(sbq, hctx)->wait; |
5815839b ML |
1140 | |
1141 | spin_lock_irq(&wq->lock); | |
1142 | spin_lock(&hctx->dispatch_wait_lock); | |
c27d53fb | 1143 | if (!list_empty(&wait->entry)) { |
5815839b ML |
1144 | spin_unlock(&hctx->dispatch_wait_lock); |
1145 | spin_unlock_irq(&wq->lock); | |
c27d53fb | 1146 | return false; |
eb619fdb JA |
1147 | } |
1148 | ||
e8618575 | 1149 | atomic_inc(&sbq->ws_active); |
5815839b ML |
1150 | wait->flags &= ~WQ_FLAG_EXCLUSIVE; |
1151 | __add_wait_queue(wq, wait); | |
c27d53fb | 1152 | |
da55f2cc | 1153 | /* |
eb619fdb JA |
1154 | * It's possible that a tag was freed in the window between the |
1155 | * allocation failure and adding the hardware queue to the wait | |
1156 | * queue. | |
da55f2cc | 1157 | */ |
8ab6bb9e | 1158 | ret = blk_mq_get_driver_tag(rq); |
c27d53fb | 1159 | if (!ret) { |
5815839b ML |
1160 | spin_unlock(&hctx->dispatch_wait_lock); |
1161 | spin_unlock_irq(&wq->lock); | |
c27d53fb | 1162 | return false; |
eb619fdb | 1163 | } |
c27d53fb BVA |
1164 | |
1165 | /* | |
1166 | * We got a tag, remove ourselves from the wait queue to ensure | |
1167 | * someone else gets the wakeup. | |
1168 | */ | |
c27d53fb | 1169 | list_del_init(&wait->entry); |
e8618575 | 1170 | atomic_dec(&sbq->ws_active); |
5815839b ML |
1171 | spin_unlock(&hctx->dispatch_wait_lock); |
1172 | spin_unlock_irq(&wq->lock); | |
c27d53fb BVA |
1173 | |
1174 | return true; | |
da55f2cc OS |
1175 | } |
1176 | ||
6e768717 ML |
1177 | #define BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT 8 |
1178 | #define BLK_MQ_DISPATCH_BUSY_EWMA_FACTOR 4 | |
1179 | /* | |
1180 | * Update dispatch busy with the Exponential Weighted Moving Average(EWMA): | |
1181 | * - EWMA is one simple way to compute running average value | |
1182 | * - weight(7/8 and 1/8) is applied so that it can decrease exponentially | |
1183 | * - take 4 as factor for avoiding to get too small(0) result, and this | |
1184 | * factor doesn't matter because EWMA decreases exponentially | |
1185 | */ | |
1186 | static void blk_mq_update_dispatch_busy(struct blk_mq_hw_ctx *hctx, bool busy) | |
1187 | { | |
1188 | unsigned int ewma; | |
1189 | ||
1190 | if (hctx->queue->elevator) | |
1191 | return; | |
1192 | ||
1193 | ewma = hctx->dispatch_busy; | |
1194 | ||
1195 | if (!ewma && !busy) | |
1196 | return; | |
1197 | ||
1198 | ewma *= BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT - 1; | |
1199 | if (busy) | |
1200 | ewma += 1 << BLK_MQ_DISPATCH_BUSY_EWMA_FACTOR; | |
1201 | ewma /= BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT; | |
1202 | ||
1203 | hctx->dispatch_busy = ewma; | |
1204 | } | |
1205 | ||
86ff7c2a ML |
1206 | #define BLK_MQ_RESOURCE_DELAY 3 /* ms units */ |
1207 | ||
1f57f8d4 JA |
1208 | /* |
1209 | * Returns true if we did some work AND can potentially do more. | |
1210 | */ | |
de148297 | 1211 | bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list, |
eb619fdb | 1212 | bool got_budget) |
320ae51f | 1213 | { |
81380ca1 | 1214 | struct blk_mq_hw_ctx *hctx; |
6d6f167c | 1215 | struct request *rq, *nxt; |
eb619fdb | 1216 | bool no_tag = false; |
fc17b653 | 1217 | int errors, queued; |
86ff7c2a | 1218 | blk_status_t ret = BLK_STS_OK; |
320ae51f | 1219 | |
81380ca1 OS |
1220 | if (list_empty(list)) |
1221 | return false; | |
1222 | ||
de148297 ML |
1223 | WARN_ON(!list_is_singular(list) && got_budget); |
1224 | ||
320ae51f JA |
1225 | /* |
1226 | * Now process all the entries, sending them to the driver. | |
1227 | */ | |
93efe981 | 1228 | errors = queued = 0; |
81380ca1 | 1229 | do { |
74c45052 | 1230 | struct blk_mq_queue_data bd; |
320ae51f | 1231 | |
f04c3df3 | 1232 | rq = list_first_entry(list, struct request, queuelist); |
0bca799b | 1233 | |
ea4f995e | 1234 | hctx = rq->mq_hctx; |
0bca799b ML |
1235 | if (!got_budget && !blk_mq_get_dispatch_budget(hctx)) |
1236 | break; | |
1237 | ||
8ab6bb9e | 1238 | if (!blk_mq_get_driver_tag(rq)) { |
3c782d67 | 1239 | /* |
da55f2cc | 1240 | * The initial allocation attempt failed, so we need to |
eb619fdb JA |
1241 | * rerun the hardware queue when a tag is freed. The |
1242 | * waitqueue takes care of that. If the queue is run | |
1243 | * before we add this entry back on the dispatch list, | |
1244 | * we'll re-run it below. | |
3c782d67 | 1245 | */ |
2278d69f | 1246 | if (!blk_mq_mark_tag_wait(hctx, rq)) { |
0bca799b | 1247 | blk_mq_put_dispatch_budget(hctx); |
f906a6a0 JA |
1248 | /* |
1249 | * For non-shared tags, the RESTART check | |
1250 | * will suffice. | |
1251 | */ | |
1252 | if (hctx->flags & BLK_MQ_F_TAG_SHARED) | |
1253 | no_tag = true; | |
de148297 ML |
1254 | break; |
1255 | } | |
1256 | } | |
1257 | ||
320ae51f | 1258 | list_del_init(&rq->queuelist); |
320ae51f | 1259 | |
74c45052 | 1260 | bd.rq = rq; |
113285b4 JA |
1261 | |
1262 | /* | |
1263 | * Flag last if we have no more requests, or if we have more | |
1264 | * but can't assign a driver tag to it. | |
1265 | */ | |
1266 | if (list_empty(list)) | |
1267 | bd.last = true; | |
1268 | else { | |
113285b4 | 1269 | nxt = list_first_entry(list, struct request, queuelist); |
8ab6bb9e | 1270 | bd.last = !blk_mq_get_driver_tag(nxt); |
113285b4 | 1271 | } |
74c45052 JA |
1272 | |
1273 | ret = q->mq_ops->queue_rq(hctx, &bd); | |
86ff7c2a | 1274 | if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) { |
6d6f167c JW |
1275 | /* |
1276 | * If an I/O scheduler has been configured and we got a | |
ff821d27 JA |
1277 | * driver tag for the next request already, free it |
1278 | * again. | |
6d6f167c JW |
1279 | */ |
1280 | if (!list_empty(list)) { | |
1281 | nxt = list_first_entry(list, struct request, queuelist); | |
1282 | blk_mq_put_driver_tag(nxt); | |
1283 | } | |
f04c3df3 | 1284 | list_add(&rq->queuelist, list); |
ed0791b2 | 1285 | __blk_mq_requeue_request(rq); |
320ae51f | 1286 | break; |
fc17b653 CH |
1287 | } |
1288 | ||
1289 | if (unlikely(ret != BLK_STS_OK)) { | |
93efe981 | 1290 | errors++; |
2a842aca | 1291 | blk_mq_end_request(rq, BLK_STS_IOERR); |
fc17b653 | 1292 | continue; |
320ae51f JA |
1293 | } |
1294 | ||
fc17b653 | 1295 | queued++; |
81380ca1 | 1296 | } while (!list_empty(list)); |
320ae51f | 1297 | |
703fd1c0 | 1298 | hctx->dispatched[queued_to_index(queued)]++; |
320ae51f JA |
1299 | |
1300 | /* | |
1301 | * Any items that need requeuing? Stuff them into hctx->dispatch, | |
1302 | * that is where we will continue on next queue run. | |
1303 | */ | |
f04c3df3 | 1304 | if (!list_empty(list)) { |
86ff7c2a ML |
1305 | bool needs_restart; |
1306 | ||
d666ba98 JA |
1307 | /* |
1308 | * If we didn't flush the entire list, we could have told | |
1309 | * the driver there was more coming, but that turned out to | |
1310 | * be a lie. | |
1311 | */ | |
1312 | if (q->mq_ops->commit_rqs) | |
1313 | q->mq_ops->commit_rqs(hctx); | |
1314 | ||
320ae51f | 1315 | spin_lock(&hctx->lock); |
9520af16 | 1316 | list_splice_tail_init(list, &hctx->dispatch); |
320ae51f | 1317 | spin_unlock(&hctx->lock); |
f04c3df3 | 1318 | |
9ba52e58 | 1319 | /* |
710c785f BVA |
1320 | * If SCHED_RESTART was set by the caller of this function and |
1321 | * it is no longer set that means that it was cleared by another | |
1322 | * thread and hence that a queue rerun is needed. | |
9ba52e58 | 1323 | * |
eb619fdb JA |
1324 | * If 'no_tag' is set, that means that we failed getting |
1325 | * a driver tag with an I/O scheduler attached. If our dispatch | |
1326 | * waitqueue is no longer active, ensure that we run the queue | |
1327 | * AFTER adding our entries back to the list. | |
bd166ef1 | 1328 | * |
710c785f BVA |
1329 | * If no I/O scheduler has been configured it is possible that |
1330 | * the hardware queue got stopped and restarted before requests | |
1331 | * were pushed back onto the dispatch list. Rerun the queue to | |
1332 | * avoid starvation. Notes: | |
1333 | * - blk_mq_run_hw_queue() checks whether or not a queue has | |
1334 | * been stopped before rerunning a queue. | |
1335 | * - Some but not all block drivers stop a queue before | |
fc17b653 | 1336 | * returning BLK_STS_RESOURCE. Two exceptions are scsi-mq |
710c785f | 1337 | * and dm-rq. |
86ff7c2a ML |
1338 | * |
1339 | * If driver returns BLK_STS_RESOURCE and SCHED_RESTART | |
1340 | * bit is set, run queue after a delay to avoid IO stalls | |
1341 | * that could otherwise occur if the queue is idle. | |
bd166ef1 | 1342 | */ |
86ff7c2a ML |
1343 | needs_restart = blk_mq_sched_needs_restart(hctx); |
1344 | if (!needs_restart || | |
eb619fdb | 1345 | (no_tag && list_empty_careful(&hctx->dispatch_wait.entry))) |
bd166ef1 | 1346 | blk_mq_run_hw_queue(hctx, true); |
86ff7c2a ML |
1347 | else if (needs_restart && (ret == BLK_STS_RESOURCE)) |
1348 | blk_mq_delay_run_hw_queue(hctx, BLK_MQ_RESOURCE_DELAY); | |
1f57f8d4 | 1349 | |
6e768717 | 1350 | blk_mq_update_dispatch_busy(hctx, true); |
1f57f8d4 | 1351 | return false; |
6e768717 ML |
1352 | } else |
1353 | blk_mq_update_dispatch_busy(hctx, false); | |
f04c3df3 | 1354 | |
1f57f8d4 JA |
1355 | /* |
1356 | * If the host/device is unable to accept more work, inform the | |
1357 | * caller of that. | |
1358 | */ | |
1359 | if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) | |
1360 | return false; | |
1361 | ||
93efe981 | 1362 | return (queued + errors) != 0; |
f04c3df3 JA |
1363 | } |
1364 | ||
6a83e74d BVA |
1365 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) |
1366 | { | |
1367 | int srcu_idx; | |
1368 | ||
b7a71e66 JA |
1369 | /* |
1370 | * We should be running this queue from one of the CPUs that | |
1371 | * are mapped to it. | |
7df938fb ML |
1372 | * |
1373 | * There are at least two related races now between setting | |
1374 | * hctx->next_cpu from blk_mq_hctx_next_cpu() and running | |
1375 | * __blk_mq_run_hw_queue(): | |
1376 | * | |
1377 | * - hctx->next_cpu is found offline in blk_mq_hctx_next_cpu(), | |
1378 | * but later it becomes online, then this warning is harmless | |
1379 | * at all | |
1380 | * | |
1381 | * - hctx->next_cpu is found online in blk_mq_hctx_next_cpu(), | |
1382 | * but later it becomes offline, then the warning can't be | |
1383 | * triggered, and we depend on blk-mq timeout handler to | |
1384 | * handle dispatched requests to this hctx | |
b7a71e66 | 1385 | */ |
7df938fb ML |
1386 | if (!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) && |
1387 | cpu_online(hctx->next_cpu)) { | |
1388 | printk(KERN_WARNING "run queue from wrong CPU %d, hctx %s\n", | |
1389 | raw_smp_processor_id(), | |
1390 | cpumask_empty(hctx->cpumask) ? "inactive": "active"); | |
1391 | dump_stack(); | |
1392 | } | |
6a83e74d | 1393 | |
b7a71e66 JA |
1394 | /* |
1395 | * We can't run the queue inline with ints disabled. Ensure that | |
1396 | * we catch bad users of this early. | |
1397 | */ | |
1398 | WARN_ON_ONCE(in_interrupt()); | |
1399 | ||
04ced159 | 1400 | might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING); |
bf4907c0 | 1401 | |
04ced159 JA |
1402 | hctx_lock(hctx, &srcu_idx); |
1403 | blk_mq_sched_dispatch_requests(hctx); | |
1404 | hctx_unlock(hctx, srcu_idx); | |
6a83e74d BVA |
1405 | } |
1406 | ||
f82ddf19 ML |
1407 | static inline int blk_mq_first_mapped_cpu(struct blk_mq_hw_ctx *hctx) |
1408 | { | |
1409 | int cpu = cpumask_first_and(hctx->cpumask, cpu_online_mask); | |
1410 | ||
1411 | if (cpu >= nr_cpu_ids) | |
1412 | cpu = cpumask_first(hctx->cpumask); | |
1413 | return cpu; | |
1414 | } | |
1415 | ||
506e931f JA |
1416 | /* |
1417 | * It'd be great if the workqueue API had a way to pass | |
1418 | * in a mask and had some smarts for more clever placement. | |
1419 | * For now we just round-robin here, switching for every | |
1420 | * BLK_MQ_CPU_WORK_BATCH queued items. | |
1421 | */ | |
1422 | static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) | |
1423 | { | |
7bed4595 | 1424 | bool tried = false; |
476f8c98 | 1425 | int next_cpu = hctx->next_cpu; |
7bed4595 | 1426 | |
b657d7e6 CH |
1427 | if (hctx->queue->nr_hw_queues == 1) |
1428 | return WORK_CPU_UNBOUND; | |
506e931f JA |
1429 | |
1430 | if (--hctx->next_cpu_batch <= 0) { | |
7bed4595 | 1431 | select_cpu: |
476f8c98 | 1432 | next_cpu = cpumask_next_and(next_cpu, hctx->cpumask, |
20e4d813 | 1433 | cpu_online_mask); |
506e931f | 1434 | if (next_cpu >= nr_cpu_ids) |
f82ddf19 | 1435 | next_cpu = blk_mq_first_mapped_cpu(hctx); |
506e931f JA |
1436 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; |
1437 | } | |
1438 | ||
7bed4595 ML |
1439 | /* |
1440 | * Do unbound schedule if we can't find a online CPU for this hctx, | |
1441 | * and it should only happen in the path of handling CPU DEAD. | |
1442 | */ | |
476f8c98 | 1443 | if (!cpu_online(next_cpu)) { |
7bed4595 ML |
1444 | if (!tried) { |
1445 | tried = true; | |
1446 | goto select_cpu; | |
1447 | } | |
1448 | ||
1449 | /* | |
1450 | * Make sure to re-select CPU next time once after CPUs | |
1451 | * in hctx->cpumask become online again. | |
1452 | */ | |
476f8c98 | 1453 | hctx->next_cpu = next_cpu; |
7bed4595 ML |
1454 | hctx->next_cpu_batch = 1; |
1455 | return WORK_CPU_UNBOUND; | |
1456 | } | |
476f8c98 ML |
1457 | |
1458 | hctx->next_cpu = next_cpu; | |
1459 | return next_cpu; | |
506e931f JA |
1460 | } |
1461 | ||
7587a5ae BVA |
1462 | static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async, |
1463 | unsigned long msecs) | |
320ae51f | 1464 | { |
5435c023 | 1465 | if (unlikely(blk_mq_hctx_stopped(hctx))) |
320ae51f JA |
1466 | return; |
1467 | ||
1b792f2f | 1468 | if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) { |
2a90d4aa PB |
1469 | int cpu = get_cpu(); |
1470 | if (cpumask_test_cpu(cpu, hctx->cpumask)) { | |
398205b8 | 1471 | __blk_mq_run_hw_queue(hctx); |
2a90d4aa | 1472 | put_cpu(); |
398205b8 PB |
1473 | return; |
1474 | } | |
e4043dcf | 1475 | |
2a90d4aa | 1476 | put_cpu(); |
e4043dcf | 1477 | } |
398205b8 | 1478 | |
ae943d20 BVA |
1479 | kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work, |
1480 | msecs_to_jiffies(msecs)); | |
7587a5ae BVA |
1481 | } |
1482 | ||
1483 | void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) | |
1484 | { | |
1485 | __blk_mq_delay_run_hw_queue(hctx, true, msecs); | |
1486 | } | |
1487 | EXPORT_SYMBOL(blk_mq_delay_run_hw_queue); | |
1488 | ||
79f720a7 | 1489 | bool blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
7587a5ae | 1490 | { |
24f5a90f ML |
1491 | int srcu_idx; |
1492 | bool need_run; | |
1493 | ||
1494 | /* | |
1495 | * When queue is quiesced, we may be switching io scheduler, or | |
1496 | * updating nr_hw_queues, or other things, and we can't run queue | |
1497 | * any more, even __blk_mq_hctx_has_pending() can't be called safely. | |
1498 | * | |
1499 | * And queue will be rerun in blk_mq_unquiesce_queue() if it is | |
1500 | * quiesced. | |
1501 | */ | |
04ced159 JA |
1502 | hctx_lock(hctx, &srcu_idx); |
1503 | need_run = !blk_queue_quiesced(hctx->queue) && | |
1504 | blk_mq_hctx_has_pending(hctx); | |
1505 | hctx_unlock(hctx, srcu_idx); | |
24f5a90f ML |
1506 | |
1507 | if (need_run) { | |
79f720a7 JA |
1508 | __blk_mq_delay_run_hw_queue(hctx, async, 0); |
1509 | return true; | |
1510 | } | |
1511 | ||
1512 | return false; | |
320ae51f | 1513 | } |
5b727272 | 1514 | EXPORT_SYMBOL(blk_mq_run_hw_queue); |
320ae51f | 1515 | |
b94ec296 | 1516 | void blk_mq_run_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
1517 | { |
1518 | struct blk_mq_hw_ctx *hctx; | |
1519 | int i; | |
1520 | ||
1521 | queue_for_each_hw_ctx(q, hctx, i) { | |
79f720a7 | 1522 | if (blk_mq_hctx_stopped(hctx)) |
320ae51f JA |
1523 | continue; |
1524 | ||
b94ec296 | 1525 | blk_mq_run_hw_queue(hctx, async); |
320ae51f JA |
1526 | } |
1527 | } | |
b94ec296 | 1528 | EXPORT_SYMBOL(blk_mq_run_hw_queues); |
320ae51f | 1529 | |
fd001443 BVA |
1530 | /** |
1531 | * blk_mq_queue_stopped() - check whether one or more hctxs have been stopped | |
1532 | * @q: request queue. | |
1533 | * | |
1534 | * The caller is responsible for serializing this function against | |
1535 | * blk_mq_{start,stop}_hw_queue(). | |
1536 | */ | |
1537 | bool blk_mq_queue_stopped(struct request_queue *q) | |
1538 | { | |
1539 | struct blk_mq_hw_ctx *hctx; | |
1540 | int i; | |
1541 | ||
1542 | queue_for_each_hw_ctx(q, hctx, i) | |
1543 | if (blk_mq_hctx_stopped(hctx)) | |
1544 | return true; | |
1545 | ||
1546 | return false; | |
1547 | } | |
1548 | EXPORT_SYMBOL(blk_mq_queue_stopped); | |
1549 | ||
39a70c76 ML |
1550 | /* |
1551 | * This function is often used for pausing .queue_rq() by driver when | |
1552 | * there isn't enough resource or some conditions aren't satisfied, and | |
4d606219 | 1553 | * BLK_STS_RESOURCE is usually returned. |
39a70c76 ML |
1554 | * |
1555 | * We do not guarantee that dispatch can be drained or blocked | |
1556 | * after blk_mq_stop_hw_queue() returns. Please use | |
1557 | * blk_mq_quiesce_queue() for that requirement. | |
1558 | */ | |
2719aa21 JA |
1559 | void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx) |
1560 | { | |
641a9ed6 | 1561 | cancel_delayed_work(&hctx->run_work); |
280d45f6 | 1562 | |
641a9ed6 | 1563 | set_bit(BLK_MQ_S_STOPPED, &hctx->state); |
2719aa21 | 1564 | } |
641a9ed6 | 1565 | EXPORT_SYMBOL(blk_mq_stop_hw_queue); |
2719aa21 | 1566 | |
39a70c76 ML |
1567 | /* |
1568 | * This function is often used for pausing .queue_rq() by driver when | |
1569 | * there isn't enough resource or some conditions aren't satisfied, and | |
4d606219 | 1570 | * BLK_STS_RESOURCE is usually returned. |
39a70c76 ML |
1571 | * |
1572 | * We do not guarantee that dispatch can be drained or blocked | |
1573 | * after blk_mq_stop_hw_queues() returns. Please use | |
1574 | * blk_mq_quiesce_queue() for that requirement. | |
1575 | */ | |
2719aa21 JA |
1576 | void blk_mq_stop_hw_queues(struct request_queue *q) |
1577 | { | |
641a9ed6 ML |
1578 | struct blk_mq_hw_ctx *hctx; |
1579 | int i; | |
1580 | ||
1581 | queue_for_each_hw_ctx(q, hctx, i) | |
1582 | blk_mq_stop_hw_queue(hctx); | |
280d45f6 CH |
1583 | } |
1584 | EXPORT_SYMBOL(blk_mq_stop_hw_queues); | |
1585 | ||
320ae51f JA |
1586 | void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx) |
1587 | { | |
1588 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
e4043dcf | 1589 | |
0ffbce80 | 1590 | blk_mq_run_hw_queue(hctx, false); |
320ae51f JA |
1591 | } |
1592 | EXPORT_SYMBOL(blk_mq_start_hw_queue); | |
1593 | ||
2f268556 CH |
1594 | void blk_mq_start_hw_queues(struct request_queue *q) |
1595 | { | |
1596 | struct blk_mq_hw_ctx *hctx; | |
1597 | int i; | |
1598 | ||
1599 | queue_for_each_hw_ctx(q, hctx, i) | |
1600 | blk_mq_start_hw_queue(hctx); | |
1601 | } | |
1602 | EXPORT_SYMBOL(blk_mq_start_hw_queues); | |
1603 | ||
ae911c5e JA |
1604 | void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
1605 | { | |
1606 | if (!blk_mq_hctx_stopped(hctx)) | |
1607 | return; | |
1608 | ||
1609 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
1610 | blk_mq_run_hw_queue(hctx, async); | |
1611 | } | |
1612 | EXPORT_SYMBOL_GPL(blk_mq_start_stopped_hw_queue); | |
1613 | ||
1b4a3258 | 1614 | void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
1615 | { |
1616 | struct blk_mq_hw_ctx *hctx; | |
1617 | int i; | |
1618 | ||
ae911c5e JA |
1619 | queue_for_each_hw_ctx(q, hctx, i) |
1620 | blk_mq_start_stopped_hw_queue(hctx, async); | |
320ae51f JA |
1621 | } |
1622 | EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); | |
1623 | ||
70f4db63 | 1624 | static void blk_mq_run_work_fn(struct work_struct *work) |
320ae51f JA |
1625 | { |
1626 | struct blk_mq_hw_ctx *hctx; | |
1627 | ||
9f993737 | 1628 | hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work); |
320ae51f | 1629 | |
21c6e939 | 1630 | /* |
15fe8a90 | 1631 | * If we are stopped, don't run the queue. |
21c6e939 | 1632 | */ |
15fe8a90 | 1633 | if (test_bit(BLK_MQ_S_STOPPED, &hctx->state)) |
0196d6b4 | 1634 | return; |
7587a5ae BVA |
1635 | |
1636 | __blk_mq_run_hw_queue(hctx); | |
1637 | } | |
1638 | ||
cfd0c552 | 1639 | static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx, |
cfd0c552 ML |
1640 | struct request *rq, |
1641 | bool at_head) | |
320ae51f | 1642 | { |
e57690fe | 1643 | struct blk_mq_ctx *ctx = rq->mq_ctx; |
c16d6b5a | 1644 | enum hctx_type type = hctx->type; |
e57690fe | 1645 | |
7b607814 BVA |
1646 | lockdep_assert_held(&ctx->lock); |
1647 | ||
01b983c9 JA |
1648 | trace_block_rq_insert(hctx->queue, rq); |
1649 | ||
72a0a36e | 1650 | if (at_head) |
c16d6b5a | 1651 | list_add(&rq->queuelist, &ctx->rq_lists[type]); |
72a0a36e | 1652 | else |
c16d6b5a | 1653 | list_add_tail(&rq->queuelist, &ctx->rq_lists[type]); |
cfd0c552 | 1654 | } |
4bb659b1 | 1655 | |
2c3ad667 JA |
1656 | void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, |
1657 | bool at_head) | |
cfd0c552 ML |
1658 | { |
1659 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
1660 | ||
7b607814 BVA |
1661 | lockdep_assert_held(&ctx->lock); |
1662 | ||
e57690fe | 1663 | __blk_mq_insert_req_list(hctx, rq, at_head); |
320ae51f | 1664 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f JA |
1665 | } |
1666 | ||
157f377b JA |
1667 | /* |
1668 | * Should only be used carefully, when the caller knows we want to | |
1669 | * bypass a potential IO scheduler on the target device. | |
1670 | */ | |
9520af16 ML |
1671 | void blk_mq_request_bypass_insert(struct request *rq, bool at_head, |
1672 | bool run_queue) | |
157f377b | 1673 | { |
ea4f995e | 1674 | struct blk_mq_hw_ctx *hctx = rq->mq_hctx; |
157f377b JA |
1675 | |
1676 | spin_lock(&hctx->lock); | |
9520af16 ML |
1677 | if (at_head) |
1678 | list_add(&rq->queuelist, &hctx->dispatch); | |
1679 | else | |
1680 | list_add_tail(&rq->queuelist, &hctx->dispatch); | |
157f377b JA |
1681 | spin_unlock(&hctx->lock); |
1682 | ||
b0850297 ML |
1683 | if (run_queue) |
1684 | blk_mq_run_hw_queue(hctx, false); | |
157f377b JA |
1685 | } |
1686 | ||
bd166ef1 JA |
1687 | void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, |
1688 | struct list_head *list) | |
320ae51f JA |
1689 | |
1690 | { | |
3f0cedc7 | 1691 | struct request *rq; |
c16d6b5a | 1692 | enum hctx_type type = hctx->type; |
3f0cedc7 | 1693 | |
320ae51f JA |
1694 | /* |
1695 | * preemption doesn't flush plug list, so it's possible ctx->cpu is | |
1696 | * offline now | |
1697 | */ | |
3f0cedc7 | 1698 | list_for_each_entry(rq, list, queuelist) { |
e57690fe | 1699 | BUG_ON(rq->mq_ctx != ctx); |
3f0cedc7 | 1700 | trace_block_rq_insert(hctx->queue, rq); |
320ae51f | 1701 | } |
3f0cedc7 ML |
1702 | |
1703 | spin_lock(&ctx->lock); | |
c16d6b5a | 1704 | list_splice_tail_init(list, &ctx->rq_lists[type]); |
cfd0c552 | 1705 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f | 1706 | spin_unlock(&ctx->lock); |
320ae51f JA |
1707 | } |
1708 | ||
3110fc79 | 1709 | static int plug_rq_cmp(void *priv, struct list_head *a, struct list_head *b) |
320ae51f JA |
1710 | { |
1711 | struct request *rqa = container_of(a, struct request, queuelist); | |
1712 | struct request *rqb = container_of(b, struct request, queuelist); | |
1713 | ||
3110fc79 JA |
1714 | if (rqa->mq_ctx < rqb->mq_ctx) |
1715 | return -1; | |
1716 | else if (rqa->mq_ctx > rqb->mq_ctx) | |
1717 | return 1; | |
1718 | else if (rqa->mq_hctx < rqb->mq_hctx) | |
1719 | return -1; | |
1720 | else if (rqa->mq_hctx > rqb->mq_hctx) | |
1721 | return 1; | |
1722 | ||
1723 | return blk_rq_pos(rqa) > blk_rq_pos(rqb); | |
320ae51f JA |
1724 | } |
1725 | ||
1726 | void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) | |
1727 | { | |
67cae4c9 | 1728 | struct blk_mq_hw_ctx *this_hctx; |
320ae51f JA |
1729 | struct blk_mq_ctx *this_ctx; |
1730 | struct request_queue *this_q; | |
1731 | struct request *rq; | |
1732 | LIST_HEAD(list); | |
67cae4c9 | 1733 | LIST_HEAD(rq_list); |
320ae51f JA |
1734 | unsigned int depth; |
1735 | ||
1736 | list_splice_init(&plug->mq_list, &list); | |
1737 | ||
ce5b009c JA |
1738 | if (plug->rq_count > 2 && plug->multiple_queues) |
1739 | list_sort(NULL, &list, plug_rq_cmp); | |
320ae51f | 1740 | |
bcc816df DZ |
1741 | plug->rq_count = 0; |
1742 | ||
320ae51f | 1743 | this_q = NULL; |
67cae4c9 | 1744 | this_hctx = NULL; |
320ae51f JA |
1745 | this_ctx = NULL; |
1746 | depth = 0; | |
1747 | ||
1748 | while (!list_empty(&list)) { | |
1749 | rq = list_entry_rq(list.next); | |
1750 | list_del_init(&rq->queuelist); | |
1751 | BUG_ON(!rq->q); | |
67cae4c9 JA |
1752 | if (rq->mq_hctx != this_hctx || rq->mq_ctx != this_ctx) { |
1753 | if (this_hctx) { | |
587562d0 | 1754 | trace_block_unplug(this_q, depth, !from_schedule); |
67cae4c9 JA |
1755 | blk_mq_sched_insert_requests(this_hctx, this_ctx, |
1756 | &rq_list, | |
bd166ef1 | 1757 | from_schedule); |
320ae51f JA |
1758 | } |
1759 | ||
320ae51f | 1760 | this_q = rq->q; |
67cae4c9 JA |
1761 | this_ctx = rq->mq_ctx; |
1762 | this_hctx = rq->mq_hctx; | |
320ae51f JA |
1763 | depth = 0; |
1764 | } | |
1765 | ||
1766 | depth++; | |
67cae4c9 | 1767 | list_add_tail(&rq->queuelist, &rq_list); |
320ae51f JA |
1768 | } |
1769 | ||
1770 | /* | |
67cae4c9 JA |
1771 | * If 'this_hctx' is set, we know we have entries to complete |
1772 | * on 'rq_list'. Do those. | |
320ae51f | 1773 | */ |
67cae4c9 | 1774 | if (this_hctx) { |
587562d0 | 1775 | trace_block_unplug(this_q, depth, !from_schedule); |
67cae4c9 | 1776 | blk_mq_sched_insert_requests(this_hctx, this_ctx, &rq_list, |
bd166ef1 | 1777 | from_schedule); |
320ae51f JA |
1778 | } |
1779 | } | |
1780 | ||
14ccb66b CH |
1781 | static void blk_mq_bio_to_request(struct request *rq, struct bio *bio, |
1782 | unsigned int nr_segs) | |
320ae51f | 1783 | { |
f924cdde CH |
1784 | if (bio->bi_opf & REQ_RAHEAD) |
1785 | rq->cmd_flags |= REQ_FAILFAST_MASK; | |
1786 | ||
1787 | rq->__sector = bio->bi_iter.bi_sector; | |
1788 | rq->write_hint = bio->bi_write_hint; | |
14ccb66b | 1789 | blk_rq_bio_prep(rq, bio, nr_segs); |
4b570521 | 1790 | |
6e85eaf3 | 1791 | blk_account_io_start(rq, true); |
320ae51f JA |
1792 | } |
1793 | ||
0f95549c MS |
1794 | static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx, |
1795 | struct request *rq, | |
be94f058 | 1796 | blk_qc_t *cookie, bool last) |
f984df1f | 1797 | { |
f984df1f | 1798 | struct request_queue *q = rq->q; |
f984df1f SL |
1799 | struct blk_mq_queue_data bd = { |
1800 | .rq = rq, | |
be94f058 | 1801 | .last = last, |
f984df1f | 1802 | }; |
bd166ef1 | 1803 | blk_qc_t new_cookie; |
f06345ad | 1804 | blk_status_t ret; |
0f95549c MS |
1805 | |
1806 | new_cookie = request_to_qc_t(hctx, rq); | |
1807 | ||
1808 | /* | |
1809 | * For OK queue, we are done. For error, caller may kill it. | |
1810 | * Any other error (busy), just add it to our list as we | |
1811 | * previously would have done. | |
1812 | */ | |
1813 | ret = q->mq_ops->queue_rq(hctx, &bd); | |
1814 | switch (ret) { | |
1815 | case BLK_STS_OK: | |
6ce3dd6e | 1816 | blk_mq_update_dispatch_busy(hctx, false); |
0f95549c MS |
1817 | *cookie = new_cookie; |
1818 | break; | |
1819 | case BLK_STS_RESOURCE: | |
86ff7c2a | 1820 | case BLK_STS_DEV_RESOURCE: |
6ce3dd6e | 1821 | blk_mq_update_dispatch_busy(hctx, true); |
0f95549c MS |
1822 | __blk_mq_requeue_request(rq); |
1823 | break; | |
1824 | default: | |
6ce3dd6e | 1825 | blk_mq_update_dispatch_busy(hctx, false); |
0f95549c MS |
1826 | *cookie = BLK_QC_T_NONE; |
1827 | break; | |
1828 | } | |
1829 | ||
1830 | return ret; | |
1831 | } | |
1832 | ||
fd9c40f6 | 1833 | static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, |
0f95549c | 1834 | struct request *rq, |
396eaf21 | 1835 | blk_qc_t *cookie, |
fd9c40f6 | 1836 | bool bypass_insert, bool last) |
0f95549c MS |
1837 | { |
1838 | struct request_queue *q = rq->q; | |
d964f04a ML |
1839 | bool run_queue = true; |
1840 | ||
23d4ee19 | 1841 | /* |
fd9c40f6 | 1842 | * RCU or SRCU read lock is needed before checking quiesced flag. |
23d4ee19 | 1843 | * |
fd9c40f6 BVA |
1844 | * When queue is stopped or quiesced, ignore 'bypass_insert' from |
1845 | * blk_mq_request_issue_directly(), and return BLK_STS_OK to caller, | |
1846 | * and avoid driver to try to dispatch again. | |
23d4ee19 | 1847 | */ |
fd9c40f6 | 1848 | if (blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(q)) { |
d964f04a | 1849 | run_queue = false; |
fd9c40f6 BVA |
1850 | bypass_insert = false; |
1851 | goto insert; | |
d964f04a | 1852 | } |
f984df1f | 1853 | |
fd9c40f6 BVA |
1854 | if (q->elevator && !bypass_insert) |
1855 | goto insert; | |
2253efc8 | 1856 | |
0bca799b | 1857 | if (!blk_mq_get_dispatch_budget(hctx)) |
fd9c40f6 | 1858 | goto insert; |
bd166ef1 | 1859 | |
8ab6bb9e | 1860 | if (!blk_mq_get_driver_tag(rq)) { |
0bca799b | 1861 | blk_mq_put_dispatch_budget(hctx); |
fd9c40f6 | 1862 | goto insert; |
88022d72 | 1863 | } |
de148297 | 1864 | |
fd9c40f6 BVA |
1865 | return __blk_mq_issue_directly(hctx, rq, cookie, last); |
1866 | insert: | |
1867 | if (bypass_insert) | |
1868 | return BLK_STS_RESOURCE; | |
1869 | ||
9520af16 | 1870 | blk_mq_request_bypass_insert(rq, false, run_queue); |
fd9c40f6 BVA |
1871 | return BLK_STS_OK; |
1872 | } | |
1873 | ||
1874 | static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, | |
1875 | struct request *rq, blk_qc_t *cookie) | |
1876 | { | |
1877 | blk_status_t ret; | |
1878 | int srcu_idx; | |
1879 | ||
1880 | might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING); | |
1881 | ||
1882 | hctx_lock(hctx, &srcu_idx); | |
1883 | ||
1884 | ret = __blk_mq_try_issue_directly(hctx, rq, cookie, false, true); | |
1885 | if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) | |
9520af16 | 1886 | blk_mq_request_bypass_insert(rq, false, true); |
fd9c40f6 BVA |
1887 | else if (ret != BLK_STS_OK) |
1888 | blk_mq_end_request(rq, ret); | |
1889 | ||
1890 | hctx_unlock(hctx, srcu_idx); | |
1891 | } | |
1892 | ||
1893 | blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last) | |
1894 | { | |
1895 | blk_status_t ret; | |
1896 | int srcu_idx; | |
1897 | blk_qc_t unused_cookie; | |
1898 | struct blk_mq_hw_ctx *hctx = rq->mq_hctx; | |
1899 | ||
1900 | hctx_lock(hctx, &srcu_idx); | |
1901 | ret = __blk_mq_try_issue_directly(hctx, rq, &unused_cookie, true, last); | |
04ced159 | 1902 | hctx_unlock(hctx, srcu_idx); |
7f556a44 JW |
1903 | |
1904 | return ret; | |
5eb6126e CH |
1905 | } |
1906 | ||
6ce3dd6e ML |
1907 | void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, |
1908 | struct list_head *list) | |
1909 | { | |
1910 | while (!list_empty(list)) { | |
fd9c40f6 | 1911 | blk_status_t ret; |
6ce3dd6e ML |
1912 | struct request *rq = list_first_entry(list, struct request, |
1913 | queuelist); | |
1914 | ||
1915 | list_del_init(&rq->queuelist); | |
fd9c40f6 BVA |
1916 | ret = blk_mq_request_issue_directly(rq, list_empty(list)); |
1917 | if (ret != BLK_STS_OK) { | |
1918 | if (ret == BLK_STS_RESOURCE || | |
1919 | ret == BLK_STS_DEV_RESOURCE) { | |
9520af16 | 1920 | blk_mq_request_bypass_insert(rq, false, |
c616cbee | 1921 | list_empty(list)); |
fd9c40f6 BVA |
1922 | break; |
1923 | } | |
1924 | blk_mq_end_request(rq, ret); | |
1925 | } | |
6ce3dd6e | 1926 | } |
d666ba98 JA |
1927 | |
1928 | /* | |
1929 | * If we didn't flush the entire list, we could have told | |
1930 | * the driver there was more coming, but that turned out to | |
1931 | * be a lie. | |
1932 | */ | |
fd9c40f6 | 1933 | if (!list_empty(list) && hctx->queue->mq_ops->commit_rqs) |
d666ba98 | 1934 | hctx->queue->mq_ops->commit_rqs(hctx); |
6ce3dd6e ML |
1935 | } |
1936 | ||
ce5b009c JA |
1937 | static void blk_add_rq_to_plug(struct blk_plug *plug, struct request *rq) |
1938 | { | |
1939 | list_add_tail(&rq->queuelist, &plug->mq_list); | |
1940 | plug->rq_count++; | |
1941 | if (!plug->multiple_queues && !list_is_singular(&plug->mq_list)) { | |
1942 | struct request *tmp; | |
1943 | ||
1944 | tmp = list_first_entry(&plug->mq_list, struct request, | |
1945 | queuelist); | |
1946 | if (tmp->q != rq->q) | |
1947 | plug->multiple_queues = true; | |
1948 | } | |
1949 | } | |
1950 | ||
dece1635 | 1951 | static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) |
07068d5b | 1952 | { |
ef295ecf | 1953 | const int is_sync = op_is_sync(bio->bi_opf); |
f73f44eb | 1954 | const int is_flush_fua = op_is_flush(bio->bi_opf); |
7809167d | 1955 | struct blk_mq_alloc_data data = { .flags = 0}; |
07068d5b | 1956 | struct request *rq; |
f984df1f | 1957 | struct blk_plug *plug; |
5b3f341f | 1958 | struct request *same_queue_rq = NULL; |
14ccb66b | 1959 | unsigned int nr_segs; |
7b371636 | 1960 | blk_qc_t cookie; |
07068d5b JA |
1961 | |
1962 | blk_queue_bounce(q, &bio); | |
14ccb66b | 1963 | __blk_queue_split(q, &bio, &nr_segs); |
f36ea50c | 1964 | |
e23947bd | 1965 | if (!bio_integrity_prep(bio)) |
dece1635 | 1966 | return BLK_QC_T_NONE; |
07068d5b | 1967 | |
87c279e6 | 1968 | if (!is_flush_fua && !blk_queue_nomerges(q) && |
14ccb66b | 1969 | blk_attempt_plug_merge(q, bio, nr_segs, &same_queue_rq)) |
87c279e6 | 1970 | return BLK_QC_T_NONE; |
f984df1f | 1971 | |
14ccb66b | 1972 | if (blk_mq_sched_bio_merge(q, bio, nr_segs)) |
bd166ef1 JA |
1973 | return BLK_QC_T_NONE; |
1974 | ||
d5337560 | 1975 | rq_qos_throttle(q, bio); |
87760e5e | 1976 | |
7809167d | 1977 | data.cmd_flags = bio->bi_opf; |
f9afca4d | 1978 | rq = blk_mq_get_request(q, bio, &data); |
87760e5e | 1979 | if (unlikely(!rq)) { |
c1c80384 | 1980 | rq_qos_cleanup(q, bio); |
7b6620d7 | 1981 | if (bio->bi_opf & REQ_NOWAIT) |
03a07c92 | 1982 | bio_wouldblock_error(bio); |
7b6620d7 | 1983 | return BLK_QC_T_NONE; |
87760e5e JA |
1984 | } |
1985 | ||
d6f1dda2 XW |
1986 | trace_block_getrq(q, bio, bio->bi_opf); |
1987 | ||
c1c80384 | 1988 | rq_qos_track(q, rq, bio); |
07068d5b | 1989 | |
fd2d3326 | 1990 | cookie = request_to_qc_t(data.hctx, rq); |
07068d5b | 1991 | |
970d168d BVA |
1992 | blk_mq_bio_to_request(rq, bio, nr_segs); |
1993 | ||
b49773e7 | 1994 | plug = blk_mq_plug(q, bio); |
07068d5b | 1995 | if (unlikely(is_flush_fua)) { |
923218f6 ML |
1996 | /* bypass scheduler for flush rq */ |
1997 | blk_insert_flush(rq); | |
1998 | blk_mq_run_hw_queue(data.hctx, true); | |
3154df26 ML |
1999 | } else if (plug && (q->nr_hw_queues == 1 || q->mq_ops->commit_rqs || |
2000 | !blk_queue_nonrot(q))) { | |
b2c5d16b JA |
2001 | /* |
2002 | * Use plugging if we have a ->commit_rqs() hook as well, as | |
2003 | * we know the driver uses bd->last in a smart fashion. | |
3154df26 ML |
2004 | * |
2005 | * Use normal plugging if this disk is slow HDD, as sequential | |
2006 | * IO may benefit a lot from plug merging. | |
b2c5d16b | 2007 | */ |
5f0ed774 | 2008 | unsigned int request_count = plug->rq_count; |
600271d9 SL |
2009 | struct request *last = NULL; |
2010 | ||
676d0607 | 2011 | if (!request_count) |
e6c4438b | 2012 | trace_block_plug(q); |
600271d9 SL |
2013 | else |
2014 | last = list_entry_rq(plug->mq_list.prev); | |
b094f89c | 2015 | |
600271d9 SL |
2016 | if (request_count >= BLK_MAX_REQUEST_COUNT || (last && |
2017 | blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE)) { | |
e6c4438b JM |
2018 | blk_flush_plug_list(plug, false); |
2019 | trace_block_plug(q); | |
320ae51f | 2020 | } |
b094f89c | 2021 | |
ce5b009c | 2022 | blk_add_rq_to_plug(plug, rq); |
a12de1d4 ML |
2023 | } else if (q->elevator) { |
2024 | blk_mq_sched_insert_request(rq, false, true, true); | |
2299722c | 2025 | } else if (plug && !blk_queue_nomerges(q)) { |
07068d5b | 2026 | /* |
6a83e74d | 2027 | * We do limited plugging. If the bio can be merged, do that. |
f984df1f SL |
2028 | * Otherwise the existing request in the plug list will be |
2029 | * issued. So the plug list will have one request at most | |
2299722c CH |
2030 | * The plug list might get flushed before this. If that happens, |
2031 | * the plug list is empty, and same_queue_rq is invalid. | |
07068d5b | 2032 | */ |
2299722c CH |
2033 | if (list_empty(&plug->mq_list)) |
2034 | same_queue_rq = NULL; | |
4711b573 | 2035 | if (same_queue_rq) { |
2299722c | 2036 | list_del_init(&same_queue_rq->queuelist); |
4711b573 JA |
2037 | plug->rq_count--; |
2038 | } | |
ce5b009c | 2039 | blk_add_rq_to_plug(plug, rq); |
ff3b74b8 | 2040 | trace_block_plug(q); |
2299722c | 2041 | |
dad7a3be | 2042 | if (same_queue_rq) { |
ea4f995e | 2043 | data.hctx = same_queue_rq->mq_hctx; |
ff3b74b8 | 2044 | trace_block_unplug(q, 1, true); |
2299722c | 2045 | blk_mq_try_issue_directly(data.hctx, same_queue_rq, |
fd9c40f6 | 2046 | &cookie); |
dad7a3be | 2047 | } |
a12de1d4 ML |
2048 | } else if ((q->nr_hw_queues > 1 && is_sync) || |
2049 | !data.hctx->dispatch_busy) { | |
fd9c40f6 | 2050 | blk_mq_try_issue_directly(data.hctx, rq, &cookie); |
ab42f35d | 2051 | } else { |
8fa9f556 | 2052 | blk_mq_sched_insert_request(rq, false, true, true); |
ab42f35d | 2053 | } |
320ae51f | 2054 | |
7b371636 | 2055 | return cookie; |
320ae51f JA |
2056 | } |
2057 | ||
cc71a6f4 JA |
2058 | void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, |
2059 | unsigned int hctx_idx) | |
95363efd | 2060 | { |
e9b267d9 | 2061 | struct page *page; |
320ae51f | 2062 | |
24d2f903 | 2063 | if (tags->rqs && set->ops->exit_request) { |
e9b267d9 | 2064 | int i; |
320ae51f | 2065 | |
24d2f903 | 2066 | for (i = 0; i < tags->nr_tags; i++) { |
2af8cbe3 JA |
2067 | struct request *rq = tags->static_rqs[i]; |
2068 | ||
2069 | if (!rq) | |
e9b267d9 | 2070 | continue; |
d6296d39 | 2071 | set->ops->exit_request(set, rq, hctx_idx); |
2af8cbe3 | 2072 | tags->static_rqs[i] = NULL; |
e9b267d9 | 2073 | } |
320ae51f | 2074 | } |
320ae51f | 2075 | |
24d2f903 CH |
2076 | while (!list_empty(&tags->page_list)) { |
2077 | page = list_first_entry(&tags->page_list, struct page, lru); | |
6753471c | 2078 | list_del_init(&page->lru); |
f75782e4 CM |
2079 | /* |
2080 | * Remove kmemleak object previously allocated in | |
273938bf | 2081 | * blk_mq_alloc_rqs(). |
f75782e4 CM |
2082 | */ |
2083 | kmemleak_free(page_address(page)); | |
320ae51f JA |
2084 | __free_pages(page, page->private); |
2085 | } | |
cc71a6f4 | 2086 | } |
320ae51f | 2087 | |
cc71a6f4 JA |
2088 | void blk_mq_free_rq_map(struct blk_mq_tags *tags) |
2089 | { | |
24d2f903 | 2090 | kfree(tags->rqs); |
cc71a6f4 | 2091 | tags->rqs = NULL; |
2af8cbe3 JA |
2092 | kfree(tags->static_rqs); |
2093 | tags->static_rqs = NULL; | |
320ae51f | 2094 | |
24d2f903 | 2095 | blk_mq_free_tags(tags); |
320ae51f JA |
2096 | } |
2097 | ||
cc71a6f4 JA |
2098 | struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, |
2099 | unsigned int hctx_idx, | |
2100 | unsigned int nr_tags, | |
2101 | unsigned int reserved_tags) | |
320ae51f | 2102 | { |
24d2f903 | 2103 | struct blk_mq_tags *tags; |
59f082e4 | 2104 | int node; |
320ae51f | 2105 | |
7d76f856 | 2106 | node = blk_mq_hw_queue_to_node(&set->map[HCTX_TYPE_DEFAULT], hctx_idx); |
59f082e4 SL |
2107 | if (node == NUMA_NO_NODE) |
2108 | node = set->numa_node; | |
2109 | ||
2110 | tags = blk_mq_init_tags(nr_tags, reserved_tags, node, | |
24391c0d | 2111 | BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags)); |
24d2f903 CH |
2112 | if (!tags) |
2113 | return NULL; | |
320ae51f | 2114 | |
590b5b7d | 2115 | tags->rqs = kcalloc_node(nr_tags, sizeof(struct request *), |
36e1f3d1 | 2116 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, |
59f082e4 | 2117 | node); |
24d2f903 CH |
2118 | if (!tags->rqs) { |
2119 | blk_mq_free_tags(tags); | |
2120 | return NULL; | |
2121 | } | |
320ae51f | 2122 | |
590b5b7d KC |
2123 | tags->static_rqs = kcalloc_node(nr_tags, sizeof(struct request *), |
2124 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, | |
2125 | node); | |
2af8cbe3 JA |
2126 | if (!tags->static_rqs) { |
2127 | kfree(tags->rqs); | |
2128 | blk_mq_free_tags(tags); | |
2129 | return NULL; | |
2130 | } | |
2131 | ||
cc71a6f4 JA |
2132 | return tags; |
2133 | } | |
2134 | ||
2135 | static size_t order_to_size(unsigned int order) | |
2136 | { | |
2137 | return (size_t)PAGE_SIZE << order; | |
2138 | } | |
2139 | ||
1d9bd516 TH |
2140 | static int blk_mq_init_request(struct blk_mq_tag_set *set, struct request *rq, |
2141 | unsigned int hctx_idx, int node) | |
2142 | { | |
2143 | int ret; | |
2144 | ||
2145 | if (set->ops->init_request) { | |
2146 | ret = set->ops->init_request(set, rq, hctx_idx, node); | |
2147 | if (ret) | |
2148 | return ret; | |
2149 | } | |
2150 | ||
12f5b931 | 2151 | WRITE_ONCE(rq->state, MQ_RQ_IDLE); |
1d9bd516 TH |
2152 | return 0; |
2153 | } | |
2154 | ||
cc71a6f4 JA |
2155 | int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, |
2156 | unsigned int hctx_idx, unsigned int depth) | |
2157 | { | |
2158 | unsigned int i, j, entries_per_page, max_order = 4; | |
2159 | size_t rq_size, left; | |
59f082e4 SL |
2160 | int node; |
2161 | ||
7d76f856 | 2162 | node = blk_mq_hw_queue_to_node(&set->map[HCTX_TYPE_DEFAULT], hctx_idx); |
59f082e4 SL |
2163 | if (node == NUMA_NO_NODE) |
2164 | node = set->numa_node; | |
cc71a6f4 JA |
2165 | |
2166 | INIT_LIST_HEAD(&tags->page_list); | |
2167 | ||
320ae51f JA |
2168 | /* |
2169 | * rq_size is the size of the request plus driver payload, rounded | |
2170 | * to the cacheline size | |
2171 | */ | |
24d2f903 | 2172 | rq_size = round_up(sizeof(struct request) + set->cmd_size, |
320ae51f | 2173 | cache_line_size()); |
cc71a6f4 | 2174 | left = rq_size * depth; |
320ae51f | 2175 | |
cc71a6f4 | 2176 | for (i = 0; i < depth; ) { |
320ae51f JA |
2177 | int this_order = max_order; |
2178 | struct page *page; | |
2179 | int to_do; | |
2180 | void *p; | |
2181 | ||
b3a834b1 | 2182 | while (this_order && left < order_to_size(this_order - 1)) |
320ae51f JA |
2183 | this_order--; |
2184 | ||
2185 | do { | |
59f082e4 | 2186 | page = alloc_pages_node(node, |
36e1f3d1 | 2187 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO, |
a5164405 | 2188 | this_order); |
320ae51f JA |
2189 | if (page) |
2190 | break; | |
2191 | if (!this_order--) | |
2192 | break; | |
2193 | if (order_to_size(this_order) < rq_size) | |
2194 | break; | |
2195 | } while (1); | |
2196 | ||
2197 | if (!page) | |
24d2f903 | 2198 | goto fail; |
320ae51f JA |
2199 | |
2200 | page->private = this_order; | |
24d2f903 | 2201 | list_add_tail(&page->lru, &tags->page_list); |
320ae51f JA |
2202 | |
2203 | p = page_address(page); | |
f75782e4 CM |
2204 | /* |
2205 | * Allow kmemleak to scan these pages as they contain pointers | |
2206 | * to additional allocations like via ops->init_request(). | |
2207 | */ | |
36e1f3d1 | 2208 | kmemleak_alloc(p, order_to_size(this_order), 1, GFP_NOIO); |
320ae51f | 2209 | entries_per_page = order_to_size(this_order) / rq_size; |
cc71a6f4 | 2210 | to_do = min(entries_per_page, depth - i); |
320ae51f JA |
2211 | left -= to_do * rq_size; |
2212 | for (j = 0; j < to_do; j++) { | |
2af8cbe3 JA |
2213 | struct request *rq = p; |
2214 | ||
2215 | tags->static_rqs[i] = rq; | |
1d9bd516 TH |
2216 | if (blk_mq_init_request(set, rq, hctx_idx, node)) { |
2217 | tags->static_rqs[i] = NULL; | |
2218 | goto fail; | |
e9b267d9 CH |
2219 | } |
2220 | ||
320ae51f JA |
2221 | p += rq_size; |
2222 | i++; | |
2223 | } | |
2224 | } | |
cc71a6f4 | 2225 | return 0; |
320ae51f | 2226 | |
24d2f903 | 2227 | fail: |
cc71a6f4 JA |
2228 | blk_mq_free_rqs(set, tags, hctx_idx); |
2229 | return -ENOMEM; | |
320ae51f JA |
2230 | } |
2231 | ||
e57690fe JA |
2232 | /* |
2233 | * 'cpu' is going away. splice any existing rq_list entries from this | |
2234 | * software queue to the hw queue dispatch list, and ensure that it | |
2235 | * gets run. | |
2236 | */ | |
9467f859 | 2237 | static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node) |
484b4061 | 2238 | { |
9467f859 | 2239 | struct blk_mq_hw_ctx *hctx; |
484b4061 JA |
2240 | struct blk_mq_ctx *ctx; |
2241 | LIST_HEAD(tmp); | |
c16d6b5a | 2242 | enum hctx_type type; |
484b4061 | 2243 | |
9467f859 | 2244 | hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_dead); |
e57690fe | 2245 | ctx = __blk_mq_get_ctx(hctx->queue, cpu); |
c16d6b5a | 2246 | type = hctx->type; |
484b4061 JA |
2247 | |
2248 | spin_lock(&ctx->lock); | |
c16d6b5a ML |
2249 | if (!list_empty(&ctx->rq_lists[type])) { |
2250 | list_splice_init(&ctx->rq_lists[type], &tmp); | |
484b4061 JA |
2251 | blk_mq_hctx_clear_pending(hctx, ctx); |
2252 | } | |
2253 | spin_unlock(&ctx->lock); | |
2254 | ||
2255 | if (list_empty(&tmp)) | |
9467f859 | 2256 | return 0; |
484b4061 | 2257 | |
e57690fe JA |
2258 | spin_lock(&hctx->lock); |
2259 | list_splice_tail_init(&tmp, &hctx->dispatch); | |
2260 | spin_unlock(&hctx->lock); | |
484b4061 JA |
2261 | |
2262 | blk_mq_run_hw_queue(hctx, true); | |
9467f859 | 2263 | return 0; |
484b4061 JA |
2264 | } |
2265 | ||
9467f859 | 2266 | static void blk_mq_remove_cpuhp(struct blk_mq_hw_ctx *hctx) |
484b4061 | 2267 | { |
9467f859 TG |
2268 | cpuhp_state_remove_instance_nocalls(CPUHP_BLK_MQ_DEAD, |
2269 | &hctx->cpuhp_dead); | |
484b4061 JA |
2270 | } |
2271 | ||
c3b4afca | 2272 | /* hctx->ctxs will be freed in queue's release handler */ |
08e98fc6 ML |
2273 | static void blk_mq_exit_hctx(struct request_queue *q, |
2274 | struct blk_mq_tag_set *set, | |
2275 | struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) | |
2276 | { | |
8ab0b7dc ML |
2277 | if (blk_mq_hw_queue_mapped(hctx)) |
2278 | blk_mq_tag_idle(hctx); | |
08e98fc6 | 2279 | |
f70ced09 | 2280 | if (set->ops->exit_request) |
d6296d39 | 2281 | set->ops->exit_request(set, hctx->fq->flush_rq, hctx_idx); |
f70ced09 | 2282 | |
08e98fc6 ML |
2283 | if (set->ops->exit_hctx) |
2284 | set->ops->exit_hctx(hctx, hctx_idx); | |
2285 | ||
9467f859 | 2286 | blk_mq_remove_cpuhp(hctx); |
2f8f1336 ML |
2287 | |
2288 | spin_lock(&q->unused_hctx_lock); | |
2289 | list_add(&hctx->hctx_list, &q->unused_hctx_list); | |
2290 | spin_unlock(&q->unused_hctx_lock); | |
08e98fc6 ML |
2291 | } |
2292 | ||
624dbe47 ML |
2293 | static void blk_mq_exit_hw_queues(struct request_queue *q, |
2294 | struct blk_mq_tag_set *set, int nr_queue) | |
2295 | { | |
2296 | struct blk_mq_hw_ctx *hctx; | |
2297 | unsigned int i; | |
2298 | ||
2299 | queue_for_each_hw_ctx(q, hctx, i) { | |
2300 | if (i == nr_queue) | |
2301 | break; | |
477e19de | 2302 | blk_mq_debugfs_unregister_hctx(hctx); |
08e98fc6 | 2303 | blk_mq_exit_hctx(q, set, hctx, i); |
624dbe47 | 2304 | } |
624dbe47 ML |
2305 | } |
2306 | ||
7c6c5b7c ML |
2307 | static int blk_mq_hw_ctx_size(struct blk_mq_tag_set *tag_set) |
2308 | { | |
2309 | int hw_ctx_size = sizeof(struct blk_mq_hw_ctx); | |
2310 | ||
2311 | BUILD_BUG_ON(ALIGN(offsetof(struct blk_mq_hw_ctx, srcu), | |
2312 | __alignof__(struct blk_mq_hw_ctx)) != | |
2313 | sizeof(struct blk_mq_hw_ctx)); | |
2314 | ||
2315 | if (tag_set->flags & BLK_MQ_F_BLOCKING) | |
2316 | hw_ctx_size += sizeof(struct srcu_struct); | |
2317 | ||
2318 | return hw_ctx_size; | |
2319 | } | |
2320 | ||
08e98fc6 ML |
2321 | static int blk_mq_init_hctx(struct request_queue *q, |
2322 | struct blk_mq_tag_set *set, | |
2323 | struct blk_mq_hw_ctx *hctx, unsigned hctx_idx) | |
320ae51f | 2324 | { |
7c6c5b7c ML |
2325 | hctx->queue_num = hctx_idx; |
2326 | ||
2327 | cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, &hctx->cpuhp_dead); | |
2328 | ||
2329 | hctx->tags = set->tags[hctx_idx]; | |
2330 | ||
2331 | if (set->ops->init_hctx && | |
2332 | set->ops->init_hctx(hctx, set->driver_data, hctx_idx)) | |
2333 | goto unregister_cpu_notifier; | |
08e98fc6 | 2334 | |
7c6c5b7c ML |
2335 | if (blk_mq_init_request(set, hctx->fq->flush_rq, hctx_idx, |
2336 | hctx->numa_node)) | |
2337 | goto exit_hctx; | |
2338 | return 0; | |
2339 | ||
2340 | exit_hctx: | |
2341 | if (set->ops->exit_hctx) | |
2342 | set->ops->exit_hctx(hctx, hctx_idx); | |
2343 | unregister_cpu_notifier: | |
2344 | blk_mq_remove_cpuhp(hctx); | |
2345 | return -1; | |
2346 | } | |
2347 | ||
2348 | static struct blk_mq_hw_ctx * | |
2349 | blk_mq_alloc_hctx(struct request_queue *q, struct blk_mq_tag_set *set, | |
2350 | int node) | |
2351 | { | |
2352 | struct blk_mq_hw_ctx *hctx; | |
2353 | gfp_t gfp = GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY; | |
2354 | ||
2355 | hctx = kzalloc_node(blk_mq_hw_ctx_size(set), gfp, node); | |
2356 | if (!hctx) | |
2357 | goto fail_alloc_hctx; | |
2358 | ||
2359 | if (!zalloc_cpumask_var_node(&hctx->cpumask, gfp, node)) | |
2360 | goto free_hctx; | |
2361 | ||
2362 | atomic_set(&hctx->nr_active, 0); | |
08e98fc6 | 2363 | if (node == NUMA_NO_NODE) |
7c6c5b7c ML |
2364 | node = set->numa_node; |
2365 | hctx->numa_node = node; | |
08e98fc6 | 2366 | |
9f993737 | 2367 | INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn); |
08e98fc6 ML |
2368 | spin_lock_init(&hctx->lock); |
2369 | INIT_LIST_HEAD(&hctx->dispatch); | |
2370 | hctx->queue = q; | |
2404e607 | 2371 | hctx->flags = set->flags & ~BLK_MQ_F_TAG_SHARED; |
08e98fc6 | 2372 | |
2f8f1336 ML |
2373 | INIT_LIST_HEAD(&hctx->hctx_list); |
2374 | ||
320ae51f | 2375 | /* |
08e98fc6 ML |
2376 | * Allocate space for all possible cpus to avoid allocation at |
2377 | * runtime | |
320ae51f | 2378 | */ |
d904bfa7 | 2379 | hctx->ctxs = kmalloc_array_node(nr_cpu_ids, sizeof(void *), |
7c6c5b7c | 2380 | gfp, node); |
08e98fc6 | 2381 | if (!hctx->ctxs) |
7c6c5b7c | 2382 | goto free_cpumask; |
320ae51f | 2383 | |
5b202853 | 2384 | if (sbitmap_init_node(&hctx->ctx_map, nr_cpu_ids, ilog2(8), |
7c6c5b7c | 2385 | gfp, node)) |
08e98fc6 | 2386 | goto free_ctxs; |
08e98fc6 | 2387 | hctx->nr_ctx = 0; |
320ae51f | 2388 | |
5815839b | 2389 | spin_lock_init(&hctx->dispatch_wait_lock); |
eb619fdb JA |
2390 | init_waitqueue_func_entry(&hctx->dispatch_wait, blk_mq_dispatch_wake); |
2391 | INIT_LIST_HEAD(&hctx->dispatch_wait.entry); | |
2392 | ||
5b202853 | 2393 | hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size, |
7c6c5b7c | 2394 | gfp); |
f70ced09 | 2395 | if (!hctx->fq) |
7c6c5b7c | 2396 | goto free_bitmap; |
320ae51f | 2397 | |
6a83e74d | 2398 | if (hctx->flags & BLK_MQ_F_BLOCKING) |
05707b64 | 2399 | init_srcu_struct(hctx->srcu); |
7c6c5b7c | 2400 | blk_mq_hctx_kobj_init(hctx); |
6a83e74d | 2401 | |
7c6c5b7c | 2402 | return hctx; |
320ae51f | 2403 | |
08e98fc6 | 2404 | free_bitmap: |
88459642 | 2405 | sbitmap_free(&hctx->ctx_map); |
08e98fc6 ML |
2406 | free_ctxs: |
2407 | kfree(hctx->ctxs); | |
7c6c5b7c ML |
2408 | free_cpumask: |
2409 | free_cpumask_var(hctx->cpumask); | |
2410 | free_hctx: | |
2411 | kfree(hctx); | |
2412 | fail_alloc_hctx: | |
2413 | return NULL; | |
08e98fc6 | 2414 | } |
320ae51f | 2415 | |
320ae51f JA |
2416 | static void blk_mq_init_cpu_queues(struct request_queue *q, |
2417 | unsigned int nr_hw_queues) | |
2418 | { | |
b3c661b1 JA |
2419 | struct blk_mq_tag_set *set = q->tag_set; |
2420 | unsigned int i, j; | |
320ae51f JA |
2421 | |
2422 | for_each_possible_cpu(i) { | |
2423 | struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i); | |
2424 | struct blk_mq_hw_ctx *hctx; | |
c16d6b5a | 2425 | int k; |
320ae51f | 2426 | |
320ae51f JA |
2427 | __ctx->cpu = i; |
2428 | spin_lock_init(&__ctx->lock); | |
c16d6b5a ML |
2429 | for (k = HCTX_TYPE_DEFAULT; k < HCTX_MAX_TYPES; k++) |
2430 | INIT_LIST_HEAD(&__ctx->rq_lists[k]); | |
2431 | ||
320ae51f JA |
2432 | __ctx->queue = q; |
2433 | ||
320ae51f JA |
2434 | /* |
2435 | * Set local node, IFF we have more than one hw queue. If | |
2436 | * not, we remain on the home node of the device | |
2437 | */ | |
b3c661b1 JA |
2438 | for (j = 0; j < set->nr_maps; j++) { |
2439 | hctx = blk_mq_map_queue_type(q, j, i); | |
2440 | if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE) | |
2441 | hctx->numa_node = local_memory_node(cpu_to_node(i)); | |
2442 | } | |
320ae51f JA |
2443 | } |
2444 | } | |
2445 | ||
cc71a6f4 JA |
2446 | static bool __blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, int hctx_idx) |
2447 | { | |
2448 | int ret = 0; | |
2449 | ||
2450 | set->tags[hctx_idx] = blk_mq_alloc_rq_map(set, hctx_idx, | |
2451 | set->queue_depth, set->reserved_tags); | |
2452 | if (!set->tags[hctx_idx]) | |
2453 | return false; | |
2454 | ||
2455 | ret = blk_mq_alloc_rqs(set, set->tags[hctx_idx], hctx_idx, | |
2456 | set->queue_depth); | |
2457 | if (!ret) | |
2458 | return true; | |
2459 | ||
2460 | blk_mq_free_rq_map(set->tags[hctx_idx]); | |
2461 | set->tags[hctx_idx] = NULL; | |
2462 | return false; | |
2463 | } | |
2464 | ||
2465 | static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set, | |
2466 | unsigned int hctx_idx) | |
2467 | { | |
4e6db0f2 | 2468 | if (set->tags && set->tags[hctx_idx]) { |
bd166ef1 JA |
2469 | blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx); |
2470 | blk_mq_free_rq_map(set->tags[hctx_idx]); | |
2471 | set->tags[hctx_idx] = NULL; | |
2472 | } | |
cc71a6f4 JA |
2473 | } |
2474 | ||
4b855ad3 | 2475 | static void blk_mq_map_swqueue(struct request_queue *q) |
320ae51f | 2476 | { |
b3c661b1 | 2477 | unsigned int i, j, hctx_idx; |
320ae51f JA |
2478 | struct blk_mq_hw_ctx *hctx; |
2479 | struct blk_mq_ctx *ctx; | |
2a34c087 | 2480 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f JA |
2481 | |
2482 | queue_for_each_hw_ctx(q, hctx, i) { | |
e4043dcf | 2483 | cpumask_clear(hctx->cpumask); |
320ae51f | 2484 | hctx->nr_ctx = 0; |
d416c92c | 2485 | hctx->dispatch_from = NULL; |
320ae51f JA |
2486 | } |
2487 | ||
2488 | /* | |
4b855ad3 | 2489 | * Map software to hardware queues. |
4412efec ML |
2490 | * |
2491 | * If the cpu isn't present, the cpu is mapped to first hctx. | |
320ae51f | 2492 | */ |
20e4d813 | 2493 | for_each_possible_cpu(i) { |
7d76f856 | 2494 | hctx_idx = set->map[HCTX_TYPE_DEFAULT].mq_map[i]; |
4412efec ML |
2495 | /* unmapped hw queue can be remapped after CPU topo changed */ |
2496 | if (!set->tags[hctx_idx] && | |
2497 | !__blk_mq_alloc_rq_map(set, hctx_idx)) { | |
2498 | /* | |
2499 | * If tags initialization fail for some hctx, | |
2500 | * that hctx won't be brought online. In this | |
2501 | * case, remap the current ctx to hctx[0] which | |
2502 | * is guaranteed to always have tags allocated | |
2503 | */ | |
7d76f856 | 2504 | set->map[HCTX_TYPE_DEFAULT].mq_map[i] = 0; |
4412efec ML |
2505 | } |
2506 | ||
897bb0c7 | 2507 | ctx = per_cpu_ptr(q->queue_ctx, i); |
b3c661b1 | 2508 | for (j = 0; j < set->nr_maps; j++) { |
bb94aea1 JW |
2509 | if (!set->map[j].nr_queues) { |
2510 | ctx->hctxs[j] = blk_mq_map_queue_type(q, | |
2511 | HCTX_TYPE_DEFAULT, i); | |
e5edd5f2 | 2512 | continue; |
bb94aea1 | 2513 | } |
e5edd5f2 | 2514 | |
b3c661b1 | 2515 | hctx = blk_mq_map_queue_type(q, j, i); |
8ccdf4a3 | 2516 | ctx->hctxs[j] = hctx; |
b3c661b1 JA |
2517 | /* |
2518 | * If the CPU is already set in the mask, then we've | |
2519 | * mapped this one already. This can happen if | |
2520 | * devices share queues across queue maps. | |
2521 | */ | |
2522 | if (cpumask_test_cpu(i, hctx->cpumask)) | |
2523 | continue; | |
2524 | ||
2525 | cpumask_set_cpu(i, hctx->cpumask); | |
2526 | hctx->type = j; | |
2527 | ctx->index_hw[hctx->type] = hctx->nr_ctx; | |
2528 | hctx->ctxs[hctx->nr_ctx++] = ctx; | |
2529 | ||
2530 | /* | |
2531 | * If the nr_ctx type overflows, we have exceeded the | |
2532 | * amount of sw queues we can support. | |
2533 | */ | |
2534 | BUG_ON(!hctx->nr_ctx); | |
2535 | } | |
bb94aea1 JW |
2536 | |
2537 | for (; j < HCTX_MAX_TYPES; j++) | |
2538 | ctx->hctxs[j] = blk_mq_map_queue_type(q, | |
2539 | HCTX_TYPE_DEFAULT, i); | |
320ae51f | 2540 | } |
506e931f JA |
2541 | |
2542 | queue_for_each_hw_ctx(q, hctx, i) { | |
4412efec ML |
2543 | /* |
2544 | * If no software queues are mapped to this hardware queue, | |
2545 | * disable it and free the request entries. | |
2546 | */ | |
2547 | if (!hctx->nr_ctx) { | |
2548 | /* Never unmap queue 0. We need it as a | |
2549 | * fallback in case of a new remap fails | |
2550 | * allocation | |
2551 | */ | |
2552 | if (i && set->tags[i]) | |
2553 | blk_mq_free_map_and_requests(set, i); | |
2554 | ||
2555 | hctx->tags = NULL; | |
2556 | continue; | |
2557 | } | |
484b4061 | 2558 | |
2a34c087 ML |
2559 | hctx->tags = set->tags[i]; |
2560 | WARN_ON(!hctx->tags); | |
2561 | ||
889fa31f CY |
2562 | /* |
2563 | * Set the map size to the number of mapped software queues. | |
2564 | * This is more accurate and more efficient than looping | |
2565 | * over all possibly mapped software queues. | |
2566 | */ | |
88459642 | 2567 | sbitmap_resize(&hctx->ctx_map, hctx->nr_ctx); |
889fa31f | 2568 | |
484b4061 JA |
2569 | /* |
2570 | * Initialize batch roundrobin counts | |
2571 | */ | |
f82ddf19 | 2572 | hctx->next_cpu = blk_mq_first_mapped_cpu(hctx); |
506e931f JA |
2573 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; |
2574 | } | |
320ae51f JA |
2575 | } |
2576 | ||
8e8320c9 JA |
2577 | /* |
2578 | * Caller needs to ensure that we're either frozen/quiesced, or that | |
2579 | * the queue isn't live yet. | |
2580 | */ | |
2404e607 | 2581 | static void queue_set_hctx_shared(struct request_queue *q, bool shared) |
0d2602ca JA |
2582 | { |
2583 | struct blk_mq_hw_ctx *hctx; | |
0d2602ca JA |
2584 | int i; |
2585 | ||
2404e607 | 2586 | queue_for_each_hw_ctx(q, hctx, i) { |
97889f9a | 2587 | if (shared) |
2404e607 | 2588 | hctx->flags |= BLK_MQ_F_TAG_SHARED; |
97889f9a | 2589 | else |
2404e607 JM |
2590 | hctx->flags &= ~BLK_MQ_F_TAG_SHARED; |
2591 | } | |
2592 | } | |
2593 | ||
8e8320c9 JA |
2594 | static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set, |
2595 | bool shared) | |
2404e607 JM |
2596 | { |
2597 | struct request_queue *q; | |
0d2602ca | 2598 | |
705cda97 BVA |
2599 | lockdep_assert_held(&set->tag_list_lock); |
2600 | ||
0d2602ca JA |
2601 | list_for_each_entry(q, &set->tag_list, tag_set_list) { |
2602 | blk_mq_freeze_queue(q); | |
2404e607 | 2603 | queue_set_hctx_shared(q, shared); |
0d2602ca JA |
2604 | blk_mq_unfreeze_queue(q); |
2605 | } | |
2606 | } | |
2607 | ||
2608 | static void blk_mq_del_queue_tag_set(struct request_queue *q) | |
2609 | { | |
2610 | struct blk_mq_tag_set *set = q->tag_set; | |
2611 | ||
0d2602ca | 2612 | mutex_lock(&set->tag_list_lock); |
705cda97 | 2613 | list_del_rcu(&q->tag_set_list); |
2404e607 JM |
2614 | if (list_is_singular(&set->tag_list)) { |
2615 | /* just transitioned to unshared */ | |
2616 | set->flags &= ~BLK_MQ_F_TAG_SHARED; | |
2617 | /* update existing queue */ | |
2618 | blk_mq_update_tag_set_depth(set, false); | |
2619 | } | |
0d2602ca | 2620 | mutex_unlock(&set->tag_list_lock); |
a347c7ad | 2621 | INIT_LIST_HEAD(&q->tag_set_list); |
0d2602ca JA |
2622 | } |
2623 | ||
2624 | static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, | |
2625 | struct request_queue *q) | |
2626 | { | |
0d2602ca | 2627 | mutex_lock(&set->tag_list_lock); |
2404e607 | 2628 | |
ff821d27 JA |
2629 | /* |
2630 | * Check to see if we're transitioning to shared (from 1 to 2 queues). | |
2631 | */ | |
2632 | if (!list_empty(&set->tag_list) && | |
2633 | !(set->flags & BLK_MQ_F_TAG_SHARED)) { | |
2404e607 JM |
2634 | set->flags |= BLK_MQ_F_TAG_SHARED; |
2635 | /* update existing queue */ | |
2636 | blk_mq_update_tag_set_depth(set, true); | |
2637 | } | |
2638 | if (set->flags & BLK_MQ_F_TAG_SHARED) | |
2639 | queue_set_hctx_shared(q, true); | |
705cda97 | 2640 | list_add_tail_rcu(&q->tag_set_list, &set->tag_list); |
2404e607 | 2641 | |
0d2602ca JA |
2642 | mutex_unlock(&set->tag_list_lock); |
2643 | } | |
2644 | ||
1db4909e ML |
2645 | /* All allocations will be freed in release handler of q->mq_kobj */ |
2646 | static int blk_mq_alloc_ctxs(struct request_queue *q) | |
2647 | { | |
2648 | struct blk_mq_ctxs *ctxs; | |
2649 | int cpu; | |
2650 | ||
2651 | ctxs = kzalloc(sizeof(*ctxs), GFP_KERNEL); | |
2652 | if (!ctxs) | |
2653 | return -ENOMEM; | |
2654 | ||
2655 | ctxs->queue_ctx = alloc_percpu(struct blk_mq_ctx); | |
2656 | if (!ctxs->queue_ctx) | |
2657 | goto fail; | |
2658 | ||
2659 | for_each_possible_cpu(cpu) { | |
2660 | struct blk_mq_ctx *ctx = per_cpu_ptr(ctxs->queue_ctx, cpu); | |
2661 | ctx->ctxs = ctxs; | |
2662 | } | |
2663 | ||
2664 | q->mq_kobj = &ctxs->kobj; | |
2665 | q->queue_ctx = ctxs->queue_ctx; | |
2666 | ||
2667 | return 0; | |
2668 | fail: | |
2669 | kfree(ctxs); | |
2670 | return -ENOMEM; | |
2671 | } | |
2672 | ||
e09aae7e ML |
2673 | /* |
2674 | * It is the actual release handler for mq, but we do it from | |
2675 | * request queue's release handler for avoiding use-after-free | |
2676 | * and headache because q->mq_kobj shouldn't have been introduced, | |
2677 | * but we can't group ctx/kctx kobj without it. | |
2678 | */ | |
2679 | void blk_mq_release(struct request_queue *q) | |
2680 | { | |
2f8f1336 ML |
2681 | struct blk_mq_hw_ctx *hctx, *next; |
2682 | int i; | |
e09aae7e | 2683 | |
2f8f1336 ML |
2684 | queue_for_each_hw_ctx(q, hctx, i) |
2685 | WARN_ON_ONCE(hctx && list_empty(&hctx->hctx_list)); | |
2686 | ||
2687 | /* all hctx are in .unused_hctx_list now */ | |
2688 | list_for_each_entry_safe(hctx, next, &q->unused_hctx_list, hctx_list) { | |
2689 | list_del_init(&hctx->hctx_list); | |
6c8b232e | 2690 | kobject_put(&hctx->kobj); |
c3b4afca | 2691 | } |
e09aae7e ML |
2692 | |
2693 | kfree(q->queue_hw_ctx); | |
2694 | ||
7ea5fe31 ML |
2695 | /* |
2696 | * release .mq_kobj and sw queue's kobject now because | |
2697 | * both share lifetime with request queue. | |
2698 | */ | |
2699 | blk_mq_sysfs_deinit(q); | |
e09aae7e ML |
2700 | } |
2701 | ||
24d2f903 | 2702 | struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) |
b62c21b7 MS |
2703 | { |
2704 | struct request_queue *uninit_q, *q; | |
2705 | ||
6d469642 | 2706 | uninit_q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node); |
b62c21b7 MS |
2707 | if (!uninit_q) |
2708 | return ERR_PTR(-ENOMEM); | |
2709 | ||
737eb78e DLM |
2710 | /* |
2711 | * Initialize the queue without an elevator. device_add_disk() will do | |
2712 | * the initialization. | |
2713 | */ | |
2714 | q = blk_mq_init_allocated_queue(set, uninit_q, false); | |
b62c21b7 MS |
2715 | if (IS_ERR(q)) |
2716 | blk_cleanup_queue(uninit_q); | |
2717 | ||
2718 | return q; | |
2719 | } | |
2720 | EXPORT_SYMBOL(blk_mq_init_queue); | |
2721 | ||
9316a9ed JA |
2722 | /* |
2723 | * Helper for setting up a queue with mq ops, given queue depth, and | |
2724 | * the passed in mq ops flags. | |
2725 | */ | |
2726 | struct request_queue *blk_mq_init_sq_queue(struct blk_mq_tag_set *set, | |
2727 | const struct blk_mq_ops *ops, | |
2728 | unsigned int queue_depth, | |
2729 | unsigned int set_flags) | |
2730 | { | |
2731 | struct request_queue *q; | |
2732 | int ret; | |
2733 | ||
2734 | memset(set, 0, sizeof(*set)); | |
2735 | set->ops = ops; | |
2736 | set->nr_hw_queues = 1; | |
b3c661b1 | 2737 | set->nr_maps = 1; |
9316a9ed JA |
2738 | set->queue_depth = queue_depth; |
2739 | set->numa_node = NUMA_NO_NODE; | |
2740 | set->flags = set_flags; | |
2741 | ||
2742 | ret = blk_mq_alloc_tag_set(set); | |
2743 | if (ret) | |
2744 | return ERR_PTR(ret); | |
2745 | ||
2746 | q = blk_mq_init_queue(set); | |
2747 | if (IS_ERR(q)) { | |
2748 | blk_mq_free_tag_set(set); | |
2749 | return q; | |
2750 | } | |
2751 | ||
2752 | return q; | |
2753 | } | |
2754 | EXPORT_SYMBOL(blk_mq_init_sq_queue); | |
2755 | ||
34d11ffa JW |
2756 | static struct blk_mq_hw_ctx *blk_mq_alloc_and_init_hctx( |
2757 | struct blk_mq_tag_set *set, struct request_queue *q, | |
2758 | int hctx_idx, int node) | |
2759 | { | |
2f8f1336 | 2760 | struct blk_mq_hw_ctx *hctx = NULL, *tmp; |
34d11ffa | 2761 | |
2f8f1336 ML |
2762 | /* reuse dead hctx first */ |
2763 | spin_lock(&q->unused_hctx_lock); | |
2764 | list_for_each_entry(tmp, &q->unused_hctx_list, hctx_list) { | |
2765 | if (tmp->numa_node == node) { | |
2766 | hctx = tmp; | |
2767 | break; | |
2768 | } | |
2769 | } | |
2770 | if (hctx) | |
2771 | list_del_init(&hctx->hctx_list); | |
2772 | spin_unlock(&q->unused_hctx_lock); | |
2773 | ||
2774 | if (!hctx) | |
2775 | hctx = blk_mq_alloc_hctx(q, set, node); | |
34d11ffa | 2776 | if (!hctx) |
7c6c5b7c | 2777 | goto fail; |
34d11ffa | 2778 | |
7c6c5b7c ML |
2779 | if (blk_mq_init_hctx(q, set, hctx, hctx_idx)) |
2780 | goto free_hctx; | |
34d11ffa JW |
2781 | |
2782 | return hctx; | |
7c6c5b7c ML |
2783 | |
2784 | free_hctx: | |
2785 | kobject_put(&hctx->kobj); | |
2786 | fail: | |
2787 | return NULL; | |
34d11ffa JW |
2788 | } |
2789 | ||
868f2f0b KB |
2790 | static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, |
2791 | struct request_queue *q) | |
320ae51f | 2792 | { |
e01ad46d | 2793 | int i, j, end; |
868f2f0b | 2794 | struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx; |
f14bbe77 | 2795 | |
fb350e0a ML |
2796 | /* protect against switching io scheduler */ |
2797 | mutex_lock(&q->sysfs_lock); | |
24d2f903 | 2798 | for (i = 0; i < set->nr_hw_queues; i++) { |
868f2f0b | 2799 | int node; |
34d11ffa | 2800 | struct blk_mq_hw_ctx *hctx; |
868f2f0b | 2801 | |
7d76f856 | 2802 | node = blk_mq_hw_queue_to_node(&set->map[HCTX_TYPE_DEFAULT], i); |
34d11ffa JW |
2803 | /* |
2804 | * If the hw queue has been mapped to another numa node, | |
2805 | * we need to realloc the hctx. If allocation fails, fallback | |
2806 | * to use the previous one. | |
2807 | */ | |
2808 | if (hctxs[i] && (hctxs[i]->numa_node == node)) | |
2809 | continue; | |
868f2f0b | 2810 | |
34d11ffa JW |
2811 | hctx = blk_mq_alloc_and_init_hctx(set, q, i, node); |
2812 | if (hctx) { | |
2f8f1336 | 2813 | if (hctxs[i]) |
34d11ffa | 2814 | blk_mq_exit_hctx(q, set, hctxs[i], i); |
34d11ffa JW |
2815 | hctxs[i] = hctx; |
2816 | } else { | |
2817 | if (hctxs[i]) | |
2818 | pr_warn("Allocate new hctx on node %d fails,\ | |
2819 | fallback to previous one on node %d\n", | |
2820 | node, hctxs[i]->numa_node); | |
2821 | else | |
2822 | break; | |
868f2f0b | 2823 | } |
320ae51f | 2824 | } |
e01ad46d JW |
2825 | /* |
2826 | * Increasing nr_hw_queues fails. Free the newly allocated | |
2827 | * hctxs and keep the previous q->nr_hw_queues. | |
2828 | */ | |
2829 | if (i != set->nr_hw_queues) { | |
2830 | j = q->nr_hw_queues; | |
2831 | end = i; | |
2832 | } else { | |
2833 | j = i; | |
2834 | end = q->nr_hw_queues; | |
2835 | q->nr_hw_queues = set->nr_hw_queues; | |
2836 | } | |
34d11ffa | 2837 | |
e01ad46d | 2838 | for (; j < end; j++) { |
868f2f0b KB |
2839 | struct blk_mq_hw_ctx *hctx = hctxs[j]; |
2840 | ||
2841 | if (hctx) { | |
cc71a6f4 JA |
2842 | if (hctx->tags) |
2843 | blk_mq_free_map_and_requests(set, j); | |
868f2f0b | 2844 | blk_mq_exit_hctx(q, set, hctx, j); |
868f2f0b | 2845 | hctxs[j] = NULL; |
868f2f0b KB |
2846 | } |
2847 | } | |
fb350e0a | 2848 | mutex_unlock(&q->sysfs_lock); |
868f2f0b KB |
2849 | } |
2850 | ||
392546ae JA |
2851 | /* |
2852 | * Maximum number of hardware queues we support. For single sets, we'll never | |
2853 | * have more than the CPUs (software queues). For multiple sets, the tag_set | |
2854 | * user may have set ->nr_hw_queues larger. | |
2855 | */ | |
2856 | static unsigned int nr_hw_queues(struct blk_mq_tag_set *set) | |
2857 | { | |
2858 | if (set->nr_maps == 1) | |
2859 | return nr_cpu_ids; | |
2860 | ||
2861 | return max(set->nr_hw_queues, nr_cpu_ids); | |
2862 | } | |
2863 | ||
868f2f0b | 2864 | struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, |
737eb78e DLM |
2865 | struct request_queue *q, |
2866 | bool elevator_init) | |
868f2f0b | 2867 | { |
66841672 ML |
2868 | /* mark the queue as mq asap */ |
2869 | q->mq_ops = set->ops; | |
2870 | ||
34dbad5d | 2871 | q->poll_cb = blk_stat_alloc_callback(blk_mq_poll_stats_fn, |
720b8ccc SB |
2872 | blk_mq_poll_stats_bkt, |
2873 | BLK_MQ_POLL_STATS_BKTS, q); | |
34dbad5d OS |
2874 | if (!q->poll_cb) |
2875 | goto err_exit; | |
2876 | ||
1db4909e | 2877 | if (blk_mq_alloc_ctxs(q)) |
41de54c6 | 2878 | goto err_poll; |
868f2f0b | 2879 | |
737f98cf ML |
2880 | /* init q->mq_kobj and sw queues' kobjects */ |
2881 | blk_mq_sysfs_init(q); | |
2882 | ||
392546ae JA |
2883 | q->nr_queues = nr_hw_queues(set); |
2884 | q->queue_hw_ctx = kcalloc_node(q->nr_queues, sizeof(*(q->queue_hw_ctx)), | |
868f2f0b KB |
2885 | GFP_KERNEL, set->numa_node); |
2886 | if (!q->queue_hw_ctx) | |
1db4909e | 2887 | goto err_sys_init; |
868f2f0b | 2888 | |
2f8f1336 ML |
2889 | INIT_LIST_HEAD(&q->unused_hctx_list); |
2890 | spin_lock_init(&q->unused_hctx_lock); | |
2891 | ||
868f2f0b KB |
2892 | blk_mq_realloc_hw_ctxs(set, q); |
2893 | if (!q->nr_hw_queues) | |
2894 | goto err_hctxs; | |
320ae51f | 2895 | |
287922eb | 2896 | INIT_WORK(&q->timeout_work, blk_mq_timeout_work); |
e56f698b | 2897 | blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ); |
320ae51f | 2898 | |
a8908939 | 2899 | q->tag_set = set; |
320ae51f | 2900 | |
94eddfbe | 2901 | q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; |
cd19181b ML |
2902 | if (set->nr_maps > HCTX_TYPE_POLL && |
2903 | set->map[HCTX_TYPE_POLL].nr_queues) | |
6544d229 | 2904 | blk_queue_flag_set(QUEUE_FLAG_POLL, q); |
320ae51f | 2905 | |
1be036e9 CH |
2906 | q->sg_reserved_size = INT_MAX; |
2907 | ||
2849450a | 2908 | INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work); |
6fca6a61 CH |
2909 | INIT_LIST_HEAD(&q->requeue_list); |
2910 | spin_lock_init(&q->requeue_lock); | |
2911 | ||
254d259d | 2912 | blk_queue_make_request(q, blk_mq_make_request); |
07068d5b | 2913 | |
eba71768 JA |
2914 | /* |
2915 | * Do this after blk_queue_make_request() overrides it... | |
2916 | */ | |
2917 | q->nr_requests = set->queue_depth; | |
2918 | ||
64f1c21e JA |
2919 | /* |
2920 | * Default to classic polling | |
2921 | */ | |
29ece8b4 | 2922 | q->poll_nsec = BLK_MQ_POLL_CLASSIC; |
64f1c21e | 2923 | |
24d2f903 | 2924 | blk_mq_init_cpu_queues(q, set->nr_hw_queues); |
0d2602ca | 2925 | blk_mq_add_queue_tag_set(set, q); |
4b855ad3 | 2926 | blk_mq_map_swqueue(q); |
4593fdbe | 2927 | |
737eb78e DLM |
2928 | if (elevator_init) |
2929 | elevator_init_mq(q); | |
d3484991 | 2930 | |
320ae51f | 2931 | return q; |
18741986 | 2932 | |
320ae51f | 2933 | err_hctxs: |
868f2f0b | 2934 | kfree(q->queue_hw_ctx); |
73d9c8d4 | 2935 | q->nr_hw_queues = 0; |
1db4909e ML |
2936 | err_sys_init: |
2937 | blk_mq_sysfs_deinit(q); | |
41de54c6 JS |
2938 | err_poll: |
2939 | blk_stat_free_callback(q->poll_cb); | |
2940 | q->poll_cb = NULL; | |
c7de5726 ML |
2941 | err_exit: |
2942 | q->mq_ops = NULL; | |
320ae51f JA |
2943 | return ERR_PTR(-ENOMEM); |
2944 | } | |
b62c21b7 | 2945 | EXPORT_SYMBOL(blk_mq_init_allocated_queue); |
320ae51f | 2946 | |
c7e2d94b ML |
2947 | /* tags can _not_ be used after returning from blk_mq_exit_queue */ |
2948 | void blk_mq_exit_queue(struct request_queue *q) | |
320ae51f | 2949 | { |
624dbe47 | 2950 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 2951 | |
0d2602ca | 2952 | blk_mq_del_queue_tag_set(q); |
624dbe47 | 2953 | blk_mq_exit_hw_queues(q, set, set->nr_hw_queues); |
320ae51f | 2954 | } |
320ae51f | 2955 | |
a5164405 JA |
2956 | static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) |
2957 | { | |
2958 | int i; | |
2959 | ||
cc71a6f4 JA |
2960 | for (i = 0; i < set->nr_hw_queues; i++) |
2961 | if (!__blk_mq_alloc_rq_map(set, i)) | |
a5164405 | 2962 | goto out_unwind; |
a5164405 JA |
2963 | |
2964 | return 0; | |
2965 | ||
2966 | out_unwind: | |
2967 | while (--i >= 0) | |
cc71a6f4 | 2968 | blk_mq_free_rq_map(set->tags[i]); |
a5164405 | 2969 | |
a5164405 JA |
2970 | return -ENOMEM; |
2971 | } | |
2972 | ||
2973 | /* | |
2974 | * Allocate the request maps associated with this tag_set. Note that this | |
2975 | * may reduce the depth asked for, if memory is tight. set->queue_depth | |
2976 | * will be updated to reflect the allocated depth. | |
2977 | */ | |
2978 | static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) | |
2979 | { | |
2980 | unsigned int depth; | |
2981 | int err; | |
2982 | ||
2983 | depth = set->queue_depth; | |
2984 | do { | |
2985 | err = __blk_mq_alloc_rq_maps(set); | |
2986 | if (!err) | |
2987 | break; | |
2988 | ||
2989 | set->queue_depth >>= 1; | |
2990 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) { | |
2991 | err = -ENOMEM; | |
2992 | break; | |
2993 | } | |
2994 | } while (set->queue_depth); | |
2995 | ||
2996 | if (!set->queue_depth || err) { | |
2997 | pr_err("blk-mq: failed to allocate request map\n"); | |
2998 | return -ENOMEM; | |
2999 | } | |
3000 | ||
3001 | if (depth != set->queue_depth) | |
3002 | pr_info("blk-mq: reduced tag depth (%u -> %u)\n", | |
3003 | depth, set->queue_depth); | |
3004 | ||
3005 | return 0; | |
3006 | } | |
3007 | ||
ebe8bddb OS |
3008 | static int blk_mq_update_queue_map(struct blk_mq_tag_set *set) |
3009 | { | |
d413d177 BVA |
3010 | /* |
3011 | * blk_mq_map_queues() and multiple .map_queues() implementations | |
3012 | * expect that set->map[HCTX_TYPE_DEFAULT].nr_queues is set to the | |
3013 | * number of hardware queues. | |
3014 | */ | |
3015 | if (set->nr_maps == 1) | |
3016 | set->map[HCTX_TYPE_DEFAULT].nr_queues = set->nr_hw_queues; | |
3017 | ||
59388702 | 3018 | if (set->ops->map_queues && !is_kdump_kernel()) { |
b3c661b1 JA |
3019 | int i; |
3020 | ||
7d4901a9 ML |
3021 | /* |
3022 | * transport .map_queues is usually done in the following | |
3023 | * way: | |
3024 | * | |
3025 | * for (queue = 0; queue < set->nr_hw_queues; queue++) { | |
3026 | * mask = get_cpu_mask(queue) | |
3027 | * for_each_cpu(cpu, mask) | |
b3c661b1 | 3028 | * set->map[x].mq_map[cpu] = queue; |
7d4901a9 ML |
3029 | * } |
3030 | * | |
3031 | * When we need to remap, the table has to be cleared for | |
3032 | * killing stale mapping since one CPU may not be mapped | |
3033 | * to any hw queue. | |
3034 | */ | |
b3c661b1 JA |
3035 | for (i = 0; i < set->nr_maps; i++) |
3036 | blk_mq_clear_mq_map(&set->map[i]); | |
7d4901a9 | 3037 | |
ebe8bddb | 3038 | return set->ops->map_queues(set); |
b3c661b1 JA |
3039 | } else { |
3040 | BUG_ON(set->nr_maps > 1); | |
7d76f856 | 3041 | return blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]); |
b3c661b1 | 3042 | } |
ebe8bddb OS |
3043 | } |
3044 | ||
a4391c64 JA |
3045 | /* |
3046 | * Alloc a tag set to be associated with one or more request queues. | |
3047 | * May fail with EINVAL for various error conditions. May adjust the | |
c018c84f | 3048 | * requested depth down, if it's too large. In that case, the set |
a4391c64 JA |
3049 | * value will be stored in set->queue_depth. |
3050 | */ | |
24d2f903 CH |
3051 | int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) |
3052 | { | |
b3c661b1 | 3053 | int i, ret; |
da695ba2 | 3054 | |
205fb5f5 BVA |
3055 | BUILD_BUG_ON(BLK_MQ_MAX_DEPTH > 1 << BLK_MQ_UNIQUE_TAG_BITS); |
3056 | ||
24d2f903 CH |
3057 | if (!set->nr_hw_queues) |
3058 | return -EINVAL; | |
a4391c64 | 3059 | if (!set->queue_depth) |
24d2f903 CH |
3060 | return -EINVAL; |
3061 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) | |
3062 | return -EINVAL; | |
3063 | ||
7d7e0f90 | 3064 | if (!set->ops->queue_rq) |
24d2f903 CH |
3065 | return -EINVAL; |
3066 | ||
de148297 ML |
3067 | if (!set->ops->get_budget ^ !set->ops->put_budget) |
3068 | return -EINVAL; | |
3069 | ||
a4391c64 JA |
3070 | if (set->queue_depth > BLK_MQ_MAX_DEPTH) { |
3071 | pr_info("blk-mq: reduced tag depth to %u\n", | |
3072 | BLK_MQ_MAX_DEPTH); | |
3073 | set->queue_depth = BLK_MQ_MAX_DEPTH; | |
3074 | } | |
24d2f903 | 3075 | |
b3c661b1 JA |
3076 | if (!set->nr_maps) |
3077 | set->nr_maps = 1; | |
3078 | else if (set->nr_maps > HCTX_MAX_TYPES) | |
3079 | return -EINVAL; | |
3080 | ||
6637fadf SL |
3081 | /* |
3082 | * If a crashdump is active, then we are potentially in a very | |
3083 | * memory constrained environment. Limit us to 1 queue and | |
3084 | * 64 tags to prevent using too much memory. | |
3085 | */ | |
3086 | if (is_kdump_kernel()) { | |
3087 | set->nr_hw_queues = 1; | |
59388702 | 3088 | set->nr_maps = 1; |
6637fadf SL |
3089 | set->queue_depth = min(64U, set->queue_depth); |
3090 | } | |
868f2f0b | 3091 | /* |
392546ae JA |
3092 | * There is no use for more h/w queues than cpus if we just have |
3093 | * a single map | |
868f2f0b | 3094 | */ |
392546ae | 3095 | if (set->nr_maps == 1 && set->nr_hw_queues > nr_cpu_ids) |
868f2f0b | 3096 | set->nr_hw_queues = nr_cpu_ids; |
6637fadf | 3097 | |
392546ae | 3098 | set->tags = kcalloc_node(nr_hw_queues(set), sizeof(struct blk_mq_tags *), |
24d2f903 CH |
3099 | GFP_KERNEL, set->numa_node); |
3100 | if (!set->tags) | |
a5164405 | 3101 | return -ENOMEM; |
24d2f903 | 3102 | |
da695ba2 | 3103 | ret = -ENOMEM; |
b3c661b1 JA |
3104 | for (i = 0; i < set->nr_maps; i++) { |
3105 | set->map[i].mq_map = kcalloc_node(nr_cpu_ids, | |
07b35eb5 | 3106 | sizeof(set->map[i].mq_map[0]), |
b3c661b1 JA |
3107 | GFP_KERNEL, set->numa_node); |
3108 | if (!set->map[i].mq_map) | |
3109 | goto out_free_mq_map; | |
59388702 | 3110 | set->map[i].nr_queues = is_kdump_kernel() ? 1 : set->nr_hw_queues; |
b3c661b1 | 3111 | } |
bdd17e75 | 3112 | |
ebe8bddb | 3113 | ret = blk_mq_update_queue_map(set); |
da695ba2 CH |
3114 | if (ret) |
3115 | goto out_free_mq_map; | |
3116 | ||
3117 | ret = blk_mq_alloc_rq_maps(set); | |
3118 | if (ret) | |
bdd17e75 | 3119 | goto out_free_mq_map; |
24d2f903 | 3120 | |
0d2602ca JA |
3121 | mutex_init(&set->tag_list_lock); |
3122 | INIT_LIST_HEAD(&set->tag_list); | |
3123 | ||
24d2f903 | 3124 | return 0; |
bdd17e75 CH |
3125 | |
3126 | out_free_mq_map: | |
b3c661b1 JA |
3127 | for (i = 0; i < set->nr_maps; i++) { |
3128 | kfree(set->map[i].mq_map); | |
3129 | set->map[i].mq_map = NULL; | |
3130 | } | |
5676e7b6 RE |
3131 | kfree(set->tags); |
3132 | set->tags = NULL; | |
da695ba2 | 3133 | return ret; |
24d2f903 CH |
3134 | } |
3135 | EXPORT_SYMBOL(blk_mq_alloc_tag_set); | |
3136 | ||
3137 | void blk_mq_free_tag_set(struct blk_mq_tag_set *set) | |
3138 | { | |
b3c661b1 | 3139 | int i, j; |
24d2f903 | 3140 | |
392546ae | 3141 | for (i = 0; i < nr_hw_queues(set); i++) |
cc71a6f4 | 3142 | blk_mq_free_map_and_requests(set, i); |
484b4061 | 3143 | |
b3c661b1 JA |
3144 | for (j = 0; j < set->nr_maps; j++) { |
3145 | kfree(set->map[j].mq_map); | |
3146 | set->map[j].mq_map = NULL; | |
3147 | } | |
bdd17e75 | 3148 | |
981bd189 | 3149 | kfree(set->tags); |
5676e7b6 | 3150 | set->tags = NULL; |
24d2f903 CH |
3151 | } |
3152 | EXPORT_SYMBOL(blk_mq_free_tag_set); | |
3153 | ||
e3a2b3f9 JA |
3154 | int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) |
3155 | { | |
3156 | struct blk_mq_tag_set *set = q->tag_set; | |
3157 | struct blk_mq_hw_ctx *hctx; | |
3158 | int i, ret; | |
3159 | ||
bd166ef1 | 3160 | if (!set) |
e3a2b3f9 JA |
3161 | return -EINVAL; |
3162 | ||
e5fa8140 AZ |
3163 | if (q->nr_requests == nr) |
3164 | return 0; | |
3165 | ||
70f36b60 | 3166 | blk_mq_freeze_queue(q); |
24f5a90f | 3167 | blk_mq_quiesce_queue(q); |
70f36b60 | 3168 | |
e3a2b3f9 JA |
3169 | ret = 0; |
3170 | queue_for_each_hw_ctx(q, hctx, i) { | |
e9137d4b KB |
3171 | if (!hctx->tags) |
3172 | continue; | |
bd166ef1 JA |
3173 | /* |
3174 | * If we're using an MQ scheduler, just update the scheduler | |
3175 | * queue depth. This is similar to what the old code would do. | |
3176 | */ | |
70f36b60 | 3177 | if (!hctx->sched_tags) { |
c2e82a23 | 3178 | ret = blk_mq_tag_update_depth(hctx, &hctx->tags, nr, |
70f36b60 JA |
3179 | false); |
3180 | } else { | |
3181 | ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags, | |
3182 | nr, true); | |
3183 | } | |
e3a2b3f9 JA |
3184 | if (ret) |
3185 | break; | |
77f1e0a5 JA |
3186 | if (q->elevator && q->elevator->type->ops.depth_updated) |
3187 | q->elevator->type->ops.depth_updated(hctx); | |
e3a2b3f9 JA |
3188 | } |
3189 | ||
3190 | if (!ret) | |
3191 | q->nr_requests = nr; | |
3192 | ||
24f5a90f | 3193 | blk_mq_unquiesce_queue(q); |
70f36b60 | 3194 | blk_mq_unfreeze_queue(q); |
70f36b60 | 3195 | |
e3a2b3f9 JA |
3196 | return ret; |
3197 | } | |
3198 | ||
d48ece20 JW |
3199 | /* |
3200 | * request_queue and elevator_type pair. | |
3201 | * It is just used by __blk_mq_update_nr_hw_queues to cache | |
3202 | * the elevator_type associated with a request_queue. | |
3203 | */ | |
3204 | struct blk_mq_qe_pair { | |
3205 | struct list_head node; | |
3206 | struct request_queue *q; | |
3207 | struct elevator_type *type; | |
3208 | }; | |
3209 | ||
3210 | /* | |
3211 | * Cache the elevator_type in qe pair list and switch the | |
3212 | * io scheduler to 'none' | |
3213 | */ | |
3214 | static bool blk_mq_elv_switch_none(struct list_head *head, | |
3215 | struct request_queue *q) | |
3216 | { | |
3217 | struct blk_mq_qe_pair *qe; | |
3218 | ||
3219 | if (!q->elevator) | |
3220 | return true; | |
3221 | ||
3222 | qe = kmalloc(sizeof(*qe), GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY); | |
3223 | if (!qe) | |
3224 | return false; | |
3225 | ||
3226 | INIT_LIST_HEAD(&qe->node); | |
3227 | qe->q = q; | |
3228 | qe->type = q->elevator->type; | |
3229 | list_add(&qe->node, head); | |
3230 | ||
3231 | mutex_lock(&q->sysfs_lock); | |
3232 | /* | |
3233 | * After elevator_switch_mq, the previous elevator_queue will be | |
3234 | * released by elevator_release. The reference of the io scheduler | |
3235 | * module get by elevator_get will also be put. So we need to get | |
3236 | * a reference of the io scheduler module here to prevent it to be | |
3237 | * removed. | |
3238 | */ | |
3239 | __module_get(qe->type->elevator_owner); | |
3240 | elevator_switch_mq(q, NULL); | |
3241 | mutex_unlock(&q->sysfs_lock); | |
3242 | ||
3243 | return true; | |
3244 | } | |
3245 | ||
3246 | static void blk_mq_elv_switch_back(struct list_head *head, | |
3247 | struct request_queue *q) | |
3248 | { | |
3249 | struct blk_mq_qe_pair *qe; | |
3250 | struct elevator_type *t = NULL; | |
3251 | ||
3252 | list_for_each_entry(qe, head, node) | |
3253 | if (qe->q == q) { | |
3254 | t = qe->type; | |
3255 | break; | |
3256 | } | |
3257 | ||
3258 | if (!t) | |
3259 | return; | |
3260 | ||
3261 | list_del(&qe->node); | |
3262 | kfree(qe); | |
3263 | ||
3264 | mutex_lock(&q->sysfs_lock); | |
3265 | elevator_switch_mq(q, t); | |
3266 | mutex_unlock(&q->sysfs_lock); | |
3267 | } | |
3268 | ||
e4dc2b32 KB |
3269 | static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, |
3270 | int nr_hw_queues) | |
868f2f0b KB |
3271 | { |
3272 | struct request_queue *q; | |
d48ece20 | 3273 | LIST_HEAD(head); |
e01ad46d | 3274 | int prev_nr_hw_queues; |
868f2f0b | 3275 | |
705cda97 BVA |
3276 | lockdep_assert_held(&set->tag_list_lock); |
3277 | ||
392546ae | 3278 | if (set->nr_maps == 1 && nr_hw_queues > nr_cpu_ids) |
868f2f0b KB |
3279 | nr_hw_queues = nr_cpu_ids; |
3280 | if (nr_hw_queues < 1 || nr_hw_queues == set->nr_hw_queues) | |
3281 | return; | |
3282 | ||
3283 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
3284 | blk_mq_freeze_queue(q); | |
f5bbbbe4 JW |
3285 | /* |
3286 | * Sync with blk_mq_queue_tag_busy_iter. | |
3287 | */ | |
3288 | synchronize_rcu(); | |
d48ece20 JW |
3289 | /* |
3290 | * Switch IO scheduler to 'none', cleaning up the data associated | |
3291 | * with the previous scheduler. We will switch back once we are done | |
3292 | * updating the new sw to hw queue mappings. | |
3293 | */ | |
3294 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
3295 | if (!blk_mq_elv_switch_none(&head, q)) | |
3296 | goto switch_back; | |
868f2f0b | 3297 | |
477e19de JW |
3298 | list_for_each_entry(q, &set->tag_list, tag_set_list) { |
3299 | blk_mq_debugfs_unregister_hctxs(q); | |
3300 | blk_mq_sysfs_unregister(q); | |
3301 | } | |
3302 | ||
e01ad46d | 3303 | prev_nr_hw_queues = set->nr_hw_queues; |
868f2f0b | 3304 | set->nr_hw_queues = nr_hw_queues; |
ebe8bddb | 3305 | blk_mq_update_queue_map(set); |
e01ad46d | 3306 | fallback: |
868f2f0b KB |
3307 | list_for_each_entry(q, &set->tag_list, tag_set_list) { |
3308 | blk_mq_realloc_hw_ctxs(set, q); | |
e01ad46d JW |
3309 | if (q->nr_hw_queues != set->nr_hw_queues) { |
3310 | pr_warn("Increasing nr_hw_queues to %d fails, fallback to %d\n", | |
3311 | nr_hw_queues, prev_nr_hw_queues); | |
3312 | set->nr_hw_queues = prev_nr_hw_queues; | |
7d76f856 | 3313 | blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]); |
e01ad46d JW |
3314 | goto fallback; |
3315 | } | |
477e19de JW |
3316 | blk_mq_map_swqueue(q); |
3317 | } | |
3318 | ||
3319 | list_for_each_entry(q, &set->tag_list, tag_set_list) { | |
3320 | blk_mq_sysfs_register(q); | |
3321 | blk_mq_debugfs_register_hctxs(q); | |
868f2f0b KB |
3322 | } |
3323 | ||
d48ece20 JW |
3324 | switch_back: |
3325 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
3326 | blk_mq_elv_switch_back(&head, q); | |
3327 | ||
868f2f0b KB |
3328 | list_for_each_entry(q, &set->tag_list, tag_set_list) |
3329 | blk_mq_unfreeze_queue(q); | |
3330 | } | |
e4dc2b32 KB |
3331 | |
3332 | void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues) | |
3333 | { | |
3334 | mutex_lock(&set->tag_list_lock); | |
3335 | __blk_mq_update_nr_hw_queues(set, nr_hw_queues); | |
3336 | mutex_unlock(&set->tag_list_lock); | |
3337 | } | |
868f2f0b KB |
3338 | EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues); |
3339 | ||
34dbad5d OS |
3340 | /* Enable polling stats and return whether they were already enabled. */ |
3341 | static bool blk_poll_stats_enable(struct request_queue *q) | |
3342 | { | |
3343 | if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags) || | |
7dfdbc73 | 3344 | blk_queue_flag_test_and_set(QUEUE_FLAG_POLL_STATS, q)) |
34dbad5d OS |
3345 | return true; |
3346 | blk_stat_add_callback(q, q->poll_cb); | |
3347 | return false; | |
3348 | } | |
3349 | ||
3350 | static void blk_mq_poll_stats_start(struct request_queue *q) | |
3351 | { | |
3352 | /* | |
3353 | * We don't arm the callback if polling stats are not enabled or the | |
3354 | * callback is already active. | |
3355 | */ | |
3356 | if (!test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags) || | |
3357 | blk_stat_is_active(q->poll_cb)) | |
3358 | return; | |
3359 | ||
3360 | blk_stat_activate_msecs(q->poll_cb, 100); | |
3361 | } | |
3362 | ||
3363 | static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb) | |
3364 | { | |
3365 | struct request_queue *q = cb->data; | |
720b8ccc | 3366 | int bucket; |
34dbad5d | 3367 | |
720b8ccc SB |
3368 | for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS; bucket++) { |
3369 | if (cb->stat[bucket].nr_samples) | |
3370 | q->poll_stat[bucket] = cb->stat[bucket]; | |
3371 | } | |
34dbad5d OS |
3372 | } |
3373 | ||
64f1c21e JA |
3374 | static unsigned long blk_mq_poll_nsecs(struct request_queue *q, |
3375 | struct blk_mq_hw_ctx *hctx, | |
3376 | struct request *rq) | |
3377 | { | |
64f1c21e | 3378 | unsigned long ret = 0; |
720b8ccc | 3379 | int bucket; |
64f1c21e JA |
3380 | |
3381 | /* | |
3382 | * If stats collection isn't on, don't sleep but turn it on for | |
3383 | * future users | |
3384 | */ | |
34dbad5d | 3385 | if (!blk_poll_stats_enable(q)) |
64f1c21e JA |
3386 | return 0; |
3387 | ||
64f1c21e JA |
3388 | /* |
3389 | * As an optimistic guess, use half of the mean service time | |
3390 | * for this type of request. We can (and should) make this smarter. | |
3391 | * For instance, if the completion latencies are tight, we can | |
3392 | * get closer than just half the mean. This is especially | |
3393 | * important on devices where the completion latencies are longer | |
720b8ccc SB |
3394 | * than ~10 usec. We do use the stats for the relevant IO size |
3395 | * if available which does lead to better estimates. | |
64f1c21e | 3396 | */ |
720b8ccc SB |
3397 | bucket = blk_mq_poll_stats_bkt(rq); |
3398 | if (bucket < 0) | |
3399 | return ret; | |
3400 | ||
3401 | if (q->poll_stat[bucket].nr_samples) | |
3402 | ret = (q->poll_stat[bucket].mean + 1) / 2; | |
64f1c21e JA |
3403 | |
3404 | return ret; | |
3405 | } | |
3406 | ||
06426adf | 3407 | static bool blk_mq_poll_hybrid_sleep(struct request_queue *q, |
64f1c21e | 3408 | struct blk_mq_hw_ctx *hctx, |
06426adf JA |
3409 | struct request *rq) |
3410 | { | |
3411 | struct hrtimer_sleeper hs; | |
3412 | enum hrtimer_mode mode; | |
64f1c21e | 3413 | unsigned int nsecs; |
06426adf JA |
3414 | ktime_t kt; |
3415 | ||
76a86f9d | 3416 | if (rq->rq_flags & RQF_MQ_POLL_SLEPT) |
64f1c21e JA |
3417 | return false; |
3418 | ||
3419 | /* | |
1052b8ac | 3420 | * If we get here, hybrid polling is enabled. Hence poll_nsec can be: |
64f1c21e | 3421 | * |
64f1c21e JA |
3422 | * 0: use half of prev avg |
3423 | * >0: use this specific value | |
3424 | */ | |
1052b8ac | 3425 | if (q->poll_nsec > 0) |
64f1c21e JA |
3426 | nsecs = q->poll_nsec; |
3427 | else | |
3428 | nsecs = blk_mq_poll_nsecs(q, hctx, rq); | |
3429 | ||
3430 | if (!nsecs) | |
06426adf JA |
3431 | return false; |
3432 | ||
76a86f9d | 3433 | rq->rq_flags |= RQF_MQ_POLL_SLEPT; |
06426adf JA |
3434 | |
3435 | /* | |
3436 | * This will be replaced with the stats tracking code, using | |
3437 | * 'avg_completion_time / 2' as the pre-sleep target. | |
3438 | */ | |
8b0e1953 | 3439 | kt = nsecs; |
06426adf JA |
3440 | |
3441 | mode = HRTIMER_MODE_REL; | |
dbc1625f | 3442 | hrtimer_init_sleeper_on_stack(&hs, CLOCK_MONOTONIC, mode); |
06426adf JA |
3443 | hrtimer_set_expires(&hs.timer, kt); |
3444 | ||
06426adf | 3445 | do { |
5a61c363 | 3446 | if (blk_mq_rq_state(rq) == MQ_RQ_COMPLETE) |
06426adf JA |
3447 | break; |
3448 | set_current_state(TASK_UNINTERRUPTIBLE); | |
9dd8813e | 3449 | hrtimer_sleeper_start_expires(&hs, mode); |
06426adf JA |
3450 | if (hs.task) |
3451 | io_schedule(); | |
3452 | hrtimer_cancel(&hs.timer); | |
3453 | mode = HRTIMER_MODE_ABS; | |
3454 | } while (hs.task && !signal_pending(current)); | |
3455 | ||
3456 | __set_current_state(TASK_RUNNING); | |
3457 | destroy_hrtimer_on_stack(&hs.timer); | |
3458 | return true; | |
3459 | } | |
3460 | ||
1052b8ac JA |
3461 | static bool blk_mq_poll_hybrid(struct request_queue *q, |
3462 | struct blk_mq_hw_ctx *hctx, blk_qc_t cookie) | |
bbd7bb70 | 3463 | { |
1052b8ac JA |
3464 | struct request *rq; |
3465 | ||
29ece8b4 | 3466 | if (q->poll_nsec == BLK_MQ_POLL_CLASSIC) |
1052b8ac JA |
3467 | return false; |
3468 | ||
3469 | if (!blk_qc_t_is_internal(cookie)) | |
3470 | rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie)); | |
3471 | else { | |
3472 | rq = blk_mq_tag_to_rq(hctx->sched_tags, blk_qc_t_to_tag(cookie)); | |
3473 | /* | |
3474 | * With scheduling, if the request has completed, we'll | |
3475 | * get a NULL return here, as we clear the sched tag when | |
3476 | * that happens. The request still remains valid, like always, | |
3477 | * so we should be safe with just the NULL check. | |
3478 | */ | |
3479 | if (!rq) | |
3480 | return false; | |
3481 | } | |
3482 | ||
3483 | return blk_mq_poll_hybrid_sleep(q, hctx, rq); | |
3484 | } | |
3485 | ||
529262d5 CH |
3486 | /** |
3487 | * blk_poll - poll for IO completions | |
3488 | * @q: the queue | |
3489 | * @cookie: cookie passed back at IO submission time | |
3490 | * @spin: whether to spin for completions | |
3491 | * | |
3492 | * Description: | |
3493 | * Poll for completions on the passed in queue. Returns number of | |
3494 | * completed entries found. If @spin is true, then blk_poll will continue | |
3495 | * looping until at least one completion is found, unless the task is | |
3496 | * otherwise marked running (or we need to reschedule). | |
3497 | */ | |
3498 | int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin) | |
1052b8ac JA |
3499 | { |
3500 | struct blk_mq_hw_ctx *hctx; | |
bbd7bb70 JA |
3501 | long state; |
3502 | ||
529262d5 CH |
3503 | if (!blk_qc_t_valid(cookie) || |
3504 | !test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) | |
1052b8ac JA |
3505 | return 0; |
3506 | ||
529262d5 CH |
3507 | if (current->plug) |
3508 | blk_flush_plug_list(current->plug, false); | |
3509 | ||
1052b8ac JA |
3510 | hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)]; |
3511 | ||
06426adf JA |
3512 | /* |
3513 | * If we sleep, have the caller restart the poll loop to reset | |
3514 | * the state. Like for the other success return cases, the | |
3515 | * caller is responsible for checking if the IO completed. If | |
3516 | * the IO isn't complete, we'll get called again and will go | |
3517 | * straight to the busy poll loop. | |
3518 | */ | |
1052b8ac | 3519 | if (blk_mq_poll_hybrid(q, hctx, cookie)) |
85f4d4b6 | 3520 | return 1; |
06426adf | 3521 | |
bbd7bb70 JA |
3522 | hctx->poll_considered++; |
3523 | ||
3524 | state = current->state; | |
aa61bec3 | 3525 | do { |
bbd7bb70 JA |
3526 | int ret; |
3527 | ||
3528 | hctx->poll_invoked++; | |
3529 | ||
9743139c | 3530 | ret = q->mq_ops->poll(hctx); |
bbd7bb70 JA |
3531 | if (ret > 0) { |
3532 | hctx->poll_success++; | |
849a3700 | 3533 | __set_current_state(TASK_RUNNING); |
85f4d4b6 | 3534 | return ret; |
bbd7bb70 JA |
3535 | } |
3536 | ||
3537 | if (signal_pending_state(state, current)) | |
849a3700 | 3538 | __set_current_state(TASK_RUNNING); |
bbd7bb70 JA |
3539 | |
3540 | if (current->state == TASK_RUNNING) | |
85f4d4b6 | 3541 | return 1; |
0a1b8b87 | 3542 | if (ret < 0 || !spin) |
bbd7bb70 JA |
3543 | break; |
3544 | cpu_relax(); | |
aa61bec3 | 3545 | } while (!need_resched()); |
bbd7bb70 | 3546 | |
67b4110f | 3547 | __set_current_state(TASK_RUNNING); |
85f4d4b6 | 3548 | return 0; |
bbd7bb70 | 3549 | } |
529262d5 | 3550 | EXPORT_SYMBOL_GPL(blk_poll); |
bbd7bb70 | 3551 | |
9cf2bab6 JA |
3552 | unsigned int blk_mq_rq_cpu(struct request *rq) |
3553 | { | |
3554 | return rq->mq_ctx->cpu; | |
3555 | } | |
3556 | EXPORT_SYMBOL(blk_mq_rq_cpu); | |
3557 | ||
320ae51f JA |
3558 | static int __init blk_mq_init(void) |
3559 | { | |
9467f859 TG |
3560 | cpuhp_setup_state_multi(CPUHP_BLK_MQ_DEAD, "block/mq:dead", NULL, |
3561 | blk_mq_hctx_notify_dead); | |
320ae51f JA |
3562 | return 0; |
3563 | } | |
3564 | subsys_initcall(blk_mq_init); |