Commit | Line | Data |
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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; | |
a2e80f6f | 96 | unsigned int inflight[2]; |
f299b7c7 JA |
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 | if (rq->part == mi->part) |
bb4e6b14 | 106 | mi->inflight[rq_data_dir(rq)]++; |
7baa8572 JA |
107 | |
108 | return true; | |
f299b7c7 JA |
109 | } |
110 | ||
e016b782 | 111 | unsigned int blk_mq_in_flight(struct request_queue *q, struct hd_struct *part) |
f299b7c7 | 112 | { |
a2e80f6f | 113 | struct mq_inflight mi = { .part = part }; |
f299b7c7 | 114 | |
f299b7c7 | 115 | blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi); |
e016b782 | 116 | |
a2e80f6f | 117 | return mi.inflight[0] + mi.inflight[1]; |
bf0ddaba OS |
118 | } |
119 | ||
120 | void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part, | |
121 | unsigned int inflight[2]) | |
122 | { | |
a2e80f6f | 123 | struct mq_inflight mi = { .part = part }; |
bf0ddaba | 124 | |
bb4e6b14 | 125 | blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi); |
a2e80f6f PB |
126 | inflight[0] = mi.inflight[0]; |
127 | inflight[1] = mi.inflight[1]; | |
bf0ddaba OS |
128 | } |
129 | ||
1671d522 | 130 | void blk_freeze_queue_start(struct request_queue *q) |
43a5e4e2 | 131 | { |
7996a8b5 BL |
132 | mutex_lock(&q->mq_freeze_lock); |
133 | if (++q->mq_freeze_depth == 1) { | |
3ef28e83 | 134 | percpu_ref_kill(&q->q_usage_counter); |
7996a8b5 | 135 | mutex_unlock(&q->mq_freeze_lock); |
344e9ffc | 136 | if (queue_is_mq(q)) |
055f6e18 | 137 | blk_mq_run_hw_queues(q, false); |
7996a8b5 BL |
138 | } else { |
139 | mutex_unlock(&q->mq_freeze_lock); | |
cddd5d17 | 140 | } |
f3af020b | 141 | } |
1671d522 | 142 | EXPORT_SYMBOL_GPL(blk_freeze_queue_start); |
f3af020b | 143 | |
6bae363e | 144 | void blk_mq_freeze_queue_wait(struct request_queue *q) |
f3af020b | 145 | { |
3ef28e83 | 146 | wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter)); |
43a5e4e2 | 147 | } |
6bae363e | 148 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait); |
43a5e4e2 | 149 | |
f91328c4 KB |
150 | int blk_mq_freeze_queue_wait_timeout(struct request_queue *q, |
151 | unsigned long timeout) | |
152 | { | |
153 | return wait_event_timeout(q->mq_freeze_wq, | |
154 | percpu_ref_is_zero(&q->q_usage_counter), | |
155 | timeout); | |
156 | } | |
157 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait_timeout); | |
43a5e4e2 | 158 | |
f3af020b TH |
159 | /* |
160 | * Guarantee no request is in use, so we can change any data structure of | |
161 | * the queue afterward. | |
162 | */ | |
3ef28e83 | 163 | void blk_freeze_queue(struct request_queue *q) |
f3af020b | 164 | { |
3ef28e83 DW |
165 | /* |
166 | * In the !blk_mq case we are only calling this to kill the | |
167 | * q_usage_counter, otherwise this increases the freeze depth | |
168 | * and waits for it to return to zero. For this reason there is | |
169 | * no blk_unfreeze_queue(), and blk_freeze_queue() is not | |
170 | * exported to drivers as the only user for unfreeze is blk_mq. | |
171 | */ | |
1671d522 | 172 | blk_freeze_queue_start(q); |
f3af020b TH |
173 | blk_mq_freeze_queue_wait(q); |
174 | } | |
3ef28e83 DW |
175 | |
176 | void blk_mq_freeze_queue(struct request_queue *q) | |
177 | { | |
178 | /* | |
179 | * ...just an alias to keep freeze and unfreeze actions balanced | |
180 | * in the blk_mq_* namespace | |
181 | */ | |
182 | blk_freeze_queue(q); | |
183 | } | |
c761d96b | 184 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue); |
f3af020b | 185 | |
b4c6a028 | 186 | void blk_mq_unfreeze_queue(struct request_queue *q) |
320ae51f | 187 | { |
7996a8b5 BL |
188 | mutex_lock(&q->mq_freeze_lock); |
189 | q->mq_freeze_depth--; | |
190 | WARN_ON_ONCE(q->mq_freeze_depth < 0); | |
191 | if (!q->mq_freeze_depth) { | |
bdd63160 | 192 | percpu_ref_resurrect(&q->q_usage_counter); |
320ae51f | 193 | wake_up_all(&q->mq_freeze_wq); |
add703fd | 194 | } |
7996a8b5 | 195 | mutex_unlock(&q->mq_freeze_lock); |
320ae51f | 196 | } |
b4c6a028 | 197 | EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue); |
320ae51f | 198 | |
852ec809 BVA |
199 | /* |
200 | * FIXME: replace the scsi_internal_device_*block_nowait() calls in the | |
201 | * mpt3sas driver such that this function can be removed. | |
202 | */ | |
203 | void blk_mq_quiesce_queue_nowait(struct request_queue *q) | |
204 | { | |
8814ce8a | 205 | blk_queue_flag_set(QUEUE_FLAG_QUIESCED, q); |
852ec809 BVA |
206 | } |
207 | EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue_nowait); | |
208 | ||
6a83e74d | 209 | /** |
69e07c4a | 210 | * blk_mq_quiesce_queue() - wait until all ongoing dispatches have finished |
6a83e74d BVA |
211 | * @q: request queue. |
212 | * | |
213 | * Note: this function does not prevent that the struct request end_io() | |
69e07c4a ML |
214 | * callback function is invoked. Once this function is returned, we make |
215 | * sure no dispatch can happen until the queue is unquiesced via | |
216 | * blk_mq_unquiesce_queue(). | |
6a83e74d BVA |
217 | */ |
218 | void blk_mq_quiesce_queue(struct request_queue *q) | |
219 | { | |
220 | struct blk_mq_hw_ctx *hctx; | |
221 | unsigned int i; | |
222 | bool rcu = false; | |
223 | ||
1d9e9bc6 | 224 | blk_mq_quiesce_queue_nowait(q); |
f4560ffe | 225 | |
6a83e74d BVA |
226 | queue_for_each_hw_ctx(q, hctx, i) { |
227 | if (hctx->flags & BLK_MQ_F_BLOCKING) | |
05707b64 | 228 | synchronize_srcu(hctx->srcu); |
6a83e74d BVA |
229 | else |
230 | rcu = true; | |
231 | } | |
232 | if (rcu) | |
233 | synchronize_rcu(); | |
234 | } | |
235 | EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue); | |
236 | ||
e4e73913 ML |
237 | /* |
238 | * blk_mq_unquiesce_queue() - counterpart of blk_mq_quiesce_queue() | |
239 | * @q: request queue. | |
240 | * | |
241 | * This function recovers queue into the state before quiescing | |
242 | * which is done by blk_mq_quiesce_queue. | |
243 | */ | |
244 | void blk_mq_unquiesce_queue(struct request_queue *q) | |
245 | { | |
8814ce8a | 246 | blk_queue_flag_clear(QUEUE_FLAG_QUIESCED, q); |
f4560ffe | 247 | |
1d9e9bc6 ML |
248 | /* dispatch requests which are inserted during quiescing */ |
249 | blk_mq_run_hw_queues(q, true); | |
e4e73913 ML |
250 | } |
251 | EXPORT_SYMBOL_GPL(blk_mq_unquiesce_queue); | |
252 | ||
aed3ea94 JA |
253 | void blk_mq_wake_waiters(struct request_queue *q) |
254 | { | |
255 | struct blk_mq_hw_ctx *hctx; | |
256 | unsigned int i; | |
257 | ||
258 | queue_for_each_hw_ctx(q, hctx, i) | |
259 | if (blk_mq_hw_queue_mapped(hctx)) | |
260 | blk_mq_tag_wakeup_all(hctx->tags, true); | |
261 | } | |
262 | ||
320ae51f JA |
263 | bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx) |
264 | { | |
265 | return blk_mq_has_free_tags(hctx->tags); | |
266 | } | |
267 | EXPORT_SYMBOL(blk_mq_can_queue); | |
268 | ||
fe1f4526 | 269 | /* |
9a91b05b HT |
270 | * Only need start/end time stamping if we have iostat or |
271 | * blk stats enabled, or using an IO scheduler. | |
fe1f4526 JA |
272 | */ |
273 | static inline bool blk_mq_need_time_stamp(struct request *rq) | |
274 | { | |
9a91b05b | 275 | return (rq->rq_flags & (RQF_IO_STAT | RQF_STATS)) || rq->q->elevator; |
fe1f4526 JA |
276 | } |
277 | ||
e4cdf1a1 | 278 | static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data, |
6f816b4b | 279 | unsigned int tag, unsigned int op, u64 alloc_time_ns) |
320ae51f | 280 | { |
e4cdf1a1 CH |
281 | struct blk_mq_tags *tags = blk_mq_tags_from_data(data); |
282 | struct request *rq = tags->static_rqs[tag]; | |
bf9ae8c5 | 283 | req_flags_t rq_flags = 0; |
c3a148d2 | 284 | |
e4cdf1a1 CH |
285 | if (data->flags & BLK_MQ_REQ_INTERNAL) { |
286 | rq->tag = -1; | |
287 | rq->internal_tag = tag; | |
288 | } else { | |
d263ed99 | 289 | if (data->hctx->flags & BLK_MQ_F_TAG_SHARED) { |
bf9ae8c5 | 290 | rq_flags = RQF_MQ_INFLIGHT; |
e4cdf1a1 CH |
291 | atomic_inc(&data->hctx->nr_active); |
292 | } | |
293 | rq->tag = tag; | |
294 | rq->internal_tag = -1; | |
295 | data->hctx->tags->rqs[rq->tag] = rq; | |
296 | } | |
297 | ||
af76e555 | 298 | /* csd/requeue_work/fifo_time is initialized before use */ |
e4cdf1a1 CH |
299 | rq->q = data->q; |
300 | rq->mq_ctx = data->ctx; | |
ea4f995e | 301 | rq->mq_hctx = data->hctx; |
bf9ae8c5 | 302 | rq->rq_flags = rq_flags; |
ef295ecf | 303 | rq->cmd_flags = op; |
1b6d65a0 BVA |
304 | if (data->flags & BLK_MQ_REQ_PREEMPT) |
305 | rq->rq_flags |= RQF_PREEMPT; | |
e4cdf1a1 | 306 | if (blk_queue_io_stat(data->q)) |
e8064021 | 307 | rq->rq_flags |= RQF_IO_STAT; |
7c3fb70f | 308 | INIT_LIST_HEAD(&rq->queuelist); |
af76e555 CH |
309 | INIT_HLIST_NODE(&rq->hash); |
310 | RB_CLEAR_NODE(&rq->rb_node); | |
af76e555 CH |
311 | rq->rq_disk = NULL; |
312 | rq->part = NULL; | |
6f816b4b TH |
313 | #ifdef CONFIG_BLK_RQ_ALLOC_TIME |
314 | rq->alloc_time_ns = alloc_time_ns; | |
315 | #endif | |
fe1f4526 JA |
316 | if (blk_mq_need_time_stamp(rq)) |
317 | rq->start_time_ns = ktime_get_ns(); | |
318 | else | |
319 | rq->start_time_ns = 0; | |
544ccc8d | 320 | rq->io_start_time_ns = 0; |
3d244306 | 321 | rq->stats_sectors = 0; |
af76e555 CH |
322 | rq->nr_phys_segments = 0; |
323 | #if defined(CONFIG_BLK_DEV_INTEGRITY) | |
324 | rq->nr_integrity_segments = 0; | |
325 | #endif | |
af76e555 | 326 | /* tag was already set */ |
af76e555 | 327 | rq->extra_len = 0; |
079076b3 | 328 | WRITE_ONCE(rq->deadline, 0); |
af76e555 | 329 | |
f6be4fb4 JA |
330 | rq->timeout = 0; |
331 | ||
af76e555 CH |
332 | rq->end_io = NULL; |
333 | rq->end_io_data = NULL; | |
af76e555 | 334 | |
e4cdf1a1 | 335 | data->ctx->rq_dispatched[op_is_sync(op)]++; |
12f5b931 | 336 | refcount_set(&rq->ref, 1); |
e4cdf1a1 | 337 | return rq; |
5dee8577 CH |
338 | } |
339 | ||
d2c0d383 | 340 | static struct request *blk_mq_get_request(struct request_queue *q, |
f9afca4d JA |
341 | struct bio *bio, |
342 | struct blk_mq_alloc_data *data) | |
d2c0d383 CH |
343 | { |
344 | struct elevator_queue *e = q->elevator; | |
345 | struct request *rq; | |
e4cdf1a1 | 346 | unsigned int tag; |
c05f4220 | 347 | bool clear_ctx_on_error = false; |
6f816b4b | 348 | u64 alloc_time_ns = 0; |
d2c0d383 CH |
349 | |
350 | blk_queue_enter_live(q); | |
6f816b4b TH |
351 | |
352 | /* alloc_time includes depth and tag waits */ | |
353 | if (blk_queue_rq_alloc_time(q)) | |
354 | alloc_time_ns = ktime_get_ns(); | |
355 | ||
d2c0d383 | 356 | data->q = q; |
21e768b4 BVA |
357 | if (likely(!data->ctx)) { |
358 | data->ctx = blk_mq_get_ctx(q); | |
c05f4220 | 359 | clear_ctx_on_error = true; |
21e768b4 | 360 | } |
d2c0d383 | 361 | if (likely(!data->hctx)) |
f9afca4d | 362 | data->hctx = blk_mq_map_queue(q, data->cmd_flags, |
8ccdf4a3 | 363 | data->ctx); |
f9afca4d | 364 | if (data->cmd_flags & REQ_NOWAIT) |
03a07c92 | 365 | data->flags |= BLK_MQ_REQ_NOWAIT; |
d2c0d383 CH |
366 | |
367 | if (e) { | |
368 | data->flags |= BLK_MQ_REQ_INTERNAL; | |
369 | ||
370 | /* | |
371 | * Flush requests are special and go directly to the | |
17a51199 JA |
372 | * dispatch list. Don't include reserved tags in the |
373 | * limiting, as it isn't useful. | |
d2c0d383 | 374 | */ |
f9afca4d JA |
375 | if (!op_is_flush(data->cmd_flags) && |
376 | e->type->ops.limit_depth && | |
17a51199 | 377 | !(data->flags & BLK_MQ_REQ_RESERVED)) |
f9afca4d | 378 | e->type->ops.limit_depth(data->cmd_flags, data); |
d263ed99 JW |
379 | } else { |
380 | blk_mq_tag_busy(data->hctx); | |
d2c0d383 CH |
381 | } |
382 | ||
e4cdf1a1 CH |
383 | tag = blk_mq_get_tag(data); |
384 | if (tag == BLK_MQ_TAG_FAIL) { | |
c05f4220 | 385 | if (clear_ctx_on_error) |
1ad43c00 | 386 | data->ctx = NULL; |
037cebb8 CH |
387 | blk_queue_exit(q); |
388 | return NULL; | |
d2c0d383 CH |
389 | } |
390 | ||
6f816b4b | 391 | rq = blk_mq_rq_ctx_init(data, tag, data->cmd_flags, alloc_time_ns); |
f9afca4d | 392 | if (!op_is_flush(data->cmd_flags)) { |
037cebb8 | 393 | rq->elv.icq = NULL; |
f9cd4bfe | 394 | if (e && e->type->ops.prepare_request) { |
e2b3fa5a DLM |
395 | if (e->type->icq_cache) |
396 | blk_mq_sched_assign_ioc(rq); | |
44e8c2bf | 397 | |
f9cd4bfe | 398 | e->type->ops.prepare_request(rq, bio); |
5bbf4e5a | 399 | rq->rq_flags |= RQF_ELVPRIV; |
44e8c2bf | 400 | } |
037cebb8 CH |
401 | } |
402 | data->hctx->queued++; | |
403 | return rq; | |
d2c0d383 CH |
404 | } |
405 | ||
cd6ce148 | 406 | struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op, |
9a95e4ef | 407 | blk_mq_req_flags_t flags) |
320ae51f | 408 | { |
f9afca4d | 409 | struct blk_mq_alloc_data alloc_data = { .flags = flags, .cmd_flags = op }; |
bd166ef1 | 410 | struct request *rq; |
a492f075 | 411 | int ret; |
320ae51f | 412 | |
3a0a5299 | 413 | ret = blk_queue_enter(q, flags); |
a492f075 JL |
414 | if (ret) |
415 | return ERR_PTR(ret); | |
320ae51f | 416 | |
f9afca4d | 417 | rq = blk_mq_get_request(q, NULL, &alloc_data); |
3280d66a | 418 | blk_queue_exit(q); |
841bac2c | 419 | |
bd166ef1 | 420 | if (!rq) |
a492f075 | 421 | return ERR_PTR(-EWOULDBLOCK); |
0c4de0f3 CH |
422 | |
423 | rq->__data_len = 0; | |
424 | rq->__sector = (sector_t) -1; | |
425 | rq->bio = rq->biotail = NULL; | |
320ae51f JA |
426 | return rq; |
427 | } | |
4bb659b1 | 428 | EXPORT_SYMBOL(blk_mq_alloc_request); |
320ae51f | 429 | |
cd6ce148 | 430 | struct request *blk_mq_alloc_request_hctx(struct request_queue *q, |
9a95e4ef | 431 | unsigned int op, blk_mq_req_flags_t flags, unsigned int hctx_idx) |
1f5bd336 | 432 | { |
f9afca4d | 433 | struct blk_mq_alloc_data alloc_data = { .flags = flags, .cmd_flags = op }; |
1f5bd336 | 434 | struct request *rq; |
6d2809d5 | 435 | unsigned int cpu; |
1f5bd336 ML |
436 | int ret; |
437 | ||
438 | /* | |
439 | * If the tag allocator sleeps we could get an allocation for a | |
440 | * different hardware context. No need to complicate the low level | |
441 | * allocator for this for the rare use case of a command tied to | |
442 | * a specific queue. | |
443 | */ | |
444 | if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT))) | |
445 | return ERR_PTR(-EINVAL); | |
446 | ||
447 | if (hctx_idx >= q->nr_hw_queues) | |
448 | return ERR_PTR(-EIO); | |
449 | ||
3a0a5299 | 450 | ret = blk_queue_enter(q, flags); |
1f5bd336 ML |
451 | if (ret) |
452 | return ERR_PTR(ret); | |
453 | ||
c8712c6a CH |
454 | /* |
455 | * Check if the hardware context is actually mapped to anything. | |
456 | * If not tell the caller that it should skip this queue. | |
457 | */ | |
6d2809d5 OS |
458 | alloc_data.hctx = q->queue_hw_ctx[hctx_idx]; |
459 | if (!blk_mq_hw_queue_mapped(alloc_data.hctx)) { | |
460 | blk_queue_exit(q); | |
461 | return ERR_PTR(-EXDEV); | |
c8712c6a | 462 | } |
20e4d813 | 463 | cpu = cpumask_first_and(alloc_data.hctx->cpumask, cpu_online_mask); |
6d2809d5 | 464 | alloc_data.ctx = __blk_mq_get_ctx(q, cpu); |
1f5bd336 | 465 | |
f9afca4d | 466 | rq = blk_mq_get_request(q, NULL, &alloc_data); |
3280d66a | 467 | blk_queue_exit(q); |
c8712c6a | 468 | |
6d2809d5 OS |
469 | if (!rq) |
470 | return ERR_PTR(-EWOULDBLOCK); | |
471 | ||
472 | return rq; | |
1f5bd336 ML |
473 | } |
474 | EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx); | |
475 | ||
12f5b931 KB |
476 | static void __blk_mq_free_request(struct request *rq) |
477 | { | |
478 | struct request_queue *q = rq->q; | |
479 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
ea4f995e | 480 | struct blk_mq_hw_ctx *hctx = rq->mq_hctx; |
12f5b931 KB |
481 | const int sched_tag = rq->internal_tag; |
482 | ||
986d413b | 483 | blk_pm_mark_last_busy(rq); |
ea4f995e | 484 | rq->mq_hctx = NULL; |
12f5b931 KB |
485 | if (rq->tag != -1) |
486 | blk_mq_put_tag(hctx, hctx->tags, ctx, rq->tag); | |
487 | if (sched_tag != -1) | |
488 | blk_mq_put_tag(hctx, hctx->sched_tags, ctx, sched_tag); | |
489 | blk_mq_sched_restart(hctx); | |
490 | blk_queue_exit(q); | |
491 | } | |
492 | ||
6af54051 | 493 | void blk_mq_free_request(struct request *rq) |
320ae51f | 494 | { |
320ae51f | 495 | struct request_queue *q = rq->q; |
6af54051 CH |
496 | struct elevator_queue *e = q->elevator; |
497 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
ea4f995e | 498 | struct blk_mq_hw_ctx *hctx = rq->mq_hctx; |
6af54051 | 499 | |
5bbf4e5a | 500 | if (rq->rq_flags & RQF_ELVPRIV) { |
f9cd4bfe JA |
501 | if (e && e->type->ops.finish_request) |
502 | e->type->ops.finish_request(rq); | |
6af54051 CH |
503 | if (rq->elv.icq) { |
504 | put_io_context(rq->elv.icq->ioc); | |
505 | rq->elv.icq = NULL; | |
506 | } | |
507 | } | |
320ae51f | 508 | |
6af54051 | 509 | ctx->rq_completed[rq_is_sync(rq)]++; |
e8064021 | 510 | if (rq->rq_flags & RQF_MQ_INFLIGHT) |
0d2602ca | 511 | atomic_dec(&hctx->nr_active); |
87760e5e | 512 | |
7beb2f84 JA |
513 | if (unlikely(laptop_mode && !blk_rq_is_passthrough(rq))) |
514 | laptop_io_completion(q->backing_dev_info); | |
515 | ||
a7905043 | 516 | rq_qos_done(q, rq); |
0d2602ca | 517 | |
12f5b931 KB |
518 | WRITE_ONCE(rq->state, MQ_RQ_IDLE); |
519 | if (refcount_dec_and_test(&rq->ref)) | |
520 | __blk_mq_free_request(rq); | |
320ae51f | 521 | } |
1a3b595a | 522 | EXPORT_SYMBOL_GPL(blk_mq_free_request); |
320ae51f | 523 | |
2a842aca | 524 | inline void __blk_mq_end_request(struct request *rq, blk_status_t error) |
320ae51f | 525 | { |
fe1f4526 JA |
526 | u64 now = 0; |
527 | ||
528 | if (blk_mq_need_time_stamp(rq)) | |
529 | now = ktime_get_ns(); | |
522a7775 | 530 | |
4bc6339a OS |
531 | if (rq->rq_flags & RQF_STATS) { |
532 | blk_mq_poll_stats_start(rq->q); | |
522a7775 | 533 | blk_stat_add(rq, now); |
4bc6339a OS |
534 | } |
535 | ||
ed88660a OS |
536 | if (rq->internal_tag != -1) |
537 | blk_mq_sched_completed_request(rq, now); | |
538 | ||
522a7775 | 539 | blk_account_io_done(rq, now); |
0d11e6ac | 540 | |
91b63639 | 541 | if (rq->end_io) { |
a7905043 | 542 | rq_qos_done(rq->q, rq); |
320ae51f | 543 | rq->end_io(rq, error); |
91b63639 | 544 | } else { |
320ae51f | 545 | blk_mq_free_request(rq); |
91b63639 | 546 | } |
320ae51f | 547 | } |
c8a446ad | 548 | EXPORT_SYMBOL(__blk_mq_end_request); |
63151a44 | 549 | |
2a842aca | 550 | void blk_mq_end_request(struct request *rq, blk_status_t error) |
63151a44 CH |
551 | { |
552 | if (blk_update_request(rq, error, blk_rq_bytes(rq))) | |
553 | BUG(); | |
c8a446ad | 554 | __blk_mq_end_request(rq, error); |
63151a44 | 555 | } |
c8a446ad | 556 | EXPORT_SYMBOL(blk_mq_end_request); |
320ae51f | 557 | |
30a91cb4 | 558 | static void __blk_mq_complete_request_remote(void *data) |
320ae51f | 559 | { |
3d6efbf6 | 560 | struct request *rq = data; |
c7bb9ad1 | 561 | struct request_queue *q = rq->q; |
320ae51f | 562 | |
c7bb9ad1 | 563 | q->mq_ops->complete(rq); |
320ae51f | 564 | } |
320ae51f | 565 | |
453f8341 | 566 | static void __blk_mq_complete_request(struct request *rq) |
320ae51f JA |
567 | { |
568 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
c7bb9ad1 | 569 | struct request_queue *q = rq->q; |
38535201 | 570 | bool shared = false; |
320ae51f JA |
571 | int cpu; |
572 | ||
af78ff7c | 573 | WRITE_ONCE(rq->state, MQ_RQ_COMPLETE); |
36e76539 ML |
574 | /* |
575 | * Most of single queue controllers, there is only one irq vector | |
576 | * for handling IO completion, and the only irq's affinity is set | |
577 | * as all possible CPUs. On most of ARCHs, this affinity means the | |
578 | * irq is handled on one specific CPU. | |
579 | * | |
580 | * So complete IO reqeust in softirq context in case of single queue | |
581 | * for not degrading IO performance by irqsoff latency. | |
582 | */ | |
c7bb9ad1 | 583 | if (q->nr_hw_queues == 1) { |
36e76539 ML |
584 | __blk_complete_request(rq); |
585 | return; | |
586 | } | |
587 | ||
4ab32bf3 JA |
588 | /* |
589 | * For a polled request, always complete locallly, it's pointless | |
590 | * to redirect the completion. | |
591 | */ | |
592 | if ((rq->cmd_flags & REQ_HIPRI) || | |
593 | !test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags)) { | |
c7bb9ad1 | 594 | q->mq_ops->complete(rq); |
30a91cb4 CH |
595 | return; |
596 | } | |
320ae51f JA |
597 | |
598 | cpu = get_cpu(); | |
c7bb9ad1 | 599 | if (!test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags)) |
38535201 CH |
600 | shared = cpus_share_cache(cpu, ctx->cpu); |
601 | ||
602 | if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) { | |
30a91cb4 | 603 | rq->csd.func = __blk_mq_complete_request_remote; |
3d6efbf6 CH |
604 | rq->csd.info = rq; |
605 | rq->csd.flags = 0; | |
c46fff2a | 606 | smp_call_function_single_async(ctx->cpu, &rq->csd); |
3d6efbf6 | 607 | } else { |
c7bb9ad1 | 608 | q->mq_ops->complete(rq); |
3d6efbf6 | 609 | } |
320ae51f JA |
610 | put_cpu(); |
611 | } | |
30a91cb4 | 612 | |
04ced159 | 613 | static void hctx_unlock(struct blk_mq_hw_ctx *hctx, int srcu_idx) |
b7435db8 | 614 | __releases(hctx->srcu) |
04ced159 JA |
615 | { |
616 | if (!(hctx->flags & BLK_MQ_F_BLOCKING)) | |
617 | rcu_read_unlock(); | |
618 | else | |
05707b64 | 619 | srcu_read_unlock(hctx->srcu, srcu_idx); |
04ced159 JA |
620 | } |
621 | ||
622 | static void hctx_lock(struct blk_mq_hw_ctx *hctx, int *srcu_idx) | |
b7435db8 | 623 | __acquires(hctx->srcu) |
04ced159 | 624 | { |
08b5a6e2 JA |
625 | if (!(hctx->flags & BLK_MQ_F_BLOCKING)) { |
626 | /* shut up gcc false positive */ | |
627 | *srcu_idx = 0; | |
04ced159 | 628 | rcu_read_lock(); |
08b5a6e2 | 629 | } else |
05707b64 | 630 | *srcu_idx = srcu_read_lock(hctx->srcu); |
04ced159 JA |
631 | } |
632 | ||
30a91cb4 CH |
633 | /** |
634 | * blk_mq_complete_request - end I/O on a request | |
635 | * @rq: the request being processed | |
636 | * | |
637 | * Description: | |
638 | * Ends all I/O on a request. It does not handle partial completions. | |
639 | * The actual completion happens out-of-order, through a IPI handler. | |
640 | **/ | |
16c15eb1 | 641 | bool blk_mq_complete_request(struct request *rq) |
30a91cb4 | 642 | { |
12f5b931 | 643 | if (unlikely(blk_should_fake_timeout(rq->q))) |
16c15eb1 | 644 | return false; |
12f5b931 | 645 | __blk_mq_complete_request(rq); |
16c15eb1 | 646 | return true; |
30a91cb4 CH |
647 | } |
648 | EXPORT_SYMBOL(blk_mq_complete_request); | |
320ae51f | 649 | |
e2490073 | 650 | void blk_mq_start_request(struct request *rq) |
320ae51f JA |
651 | { |
652 | struct request_queue *q = rq->q; | |
653 | ||
654 | trace_block_rq_issue(q, rq); | |
655 | ||
cf43e6be | 656 | if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags)) { |
544ccc8d | 657 | rq->io_start_time_ns = ktime_get_ns(); |
3d244306 | 658 | rq->stats_sectors = blk_rq_sectors(rq); |
cf43e6be | 659 | rq->rq_flags |= RQF_STATS; |
a7905043 | 660 | rq_qos_issue(q, rq); |
cf43e6be JA |
661 | } |
662 | ||
1d9bd516 | 663 | WARN_ON_ONCE(blk_mq_rq_state(rq) != MQ_RQ_IDLE); |
538b7534 | 664 | |
1d9bd516 | 665 | blk_add_timer(rq); |
12f5b931 | 666 | WRITE_ONCE(rq->state, MQ_RQ_IN_FLIGHT); |
49f5baa5 CH |
667 | |
668 | if (q->dma_drain_size && blk_rq_bytes(rq)) { | |
669 | /* | |
670 | * Make sure space for the drain appears. We know we can do | |
671 | * this because max_hw_segments has been adjusted to be one | |
672 | * fewer than the device can handle. | |
673 | */ | |
674 | rq->nr_phys_segments++; | |
675 | } | |
54d4e6ab MG |
676 | |
677 | #ifdef CONFIG_BLK_DEV_INTEGRITY | |
678 | if (blk_integrity_rq(rq) && req_op(rq) == REQ_OP_WRITE) | |
679 | q->integrity.profile->prepare_fn(rq); | |
680 | #endif | |
320ae51f | 681 | } |
e2490073 | 682 | EXPORT_SYMBOL(blk_mq_start_request); |
320ae51f | 683 | |
ed0791b2 | 684 | static void __blk_mq_requeue_request(struct request *rq) |
320ae51f JA |
685 | { |
686 | struct request_queue *q = rq->q; | |
687 | ||
923218f6 ML |
688 | blk_mq_put_driver_tag(rq); |
689 | ||
320ae51f | 690 | trace_block_rq_requeue(q, rq); |
a7905043 | 691 | rq_qos_requeue(q, rq); |
49f5baa5 | 692 | |
12f5b931 KB |
693 | if (blk_mq_request_started(rq)) { |
694 | WRITE_ONCE(rq->state, MQ_RQ_IDLE); | |
da661267 | 695 | rq->rq_flags &= ~RQF_TIMED_OUT; |
e2490073 CH |
696 | if (q->dma_drain_size && blk_rq_bytes(rq)) |
697 | rq->nr_phys_segments--; | |
698 | } | |
320ae51f JA |
699 | } |
700 | ||
2b053aca | 701 | void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list) |
ed0791b2 | 702 | { |
ed0791b2 | 703 | __blk_mq_requeue_request(rq); |
ed0791b2 | 704 | |
105976f5 ML |
705 | /* this request will be re-inserted to io scheduler queue */ |
706 | blk_mq_sched_requeue_request(rq); | |
707 | ||
7d692330 | 708 | BUG_ON(!list_empty(&rq->queuelist)); |
2b053aca | 709 | blk_mq_add_to_requeue_list(rq, true, kick_requeue_list); |
ed0791b2 CH |
710 | } |
711 | EXPORT_SYMBOL(blk_mq_requeue_request); | |
712 | ||
6fca6a61 CH |
713 | static void blk_mq_requeue_work(struct work_struct *work) |
714 | { | |
715 | struct request_queue *q = | |
2849450a | 716 | container_of(work, struct request_queue, requeue_work.work); |
6fca6a61 CH |
717 | LIST_HEAD(rq_list); |
718 | struct request *rq, *next; | |
6fca6a61 | 719 | |
18e9781d | 720 | spin_lock_irq(&q->requeue_lock); |
6fca6a61 | 721 | list_splice_init(&q->requeue_list, &rq_list); |
18e9781d | 722 | spin_unlock_irq(&q->requeue_lock); |
6fca6a61 CH |
723 | |
724 | list_for_each_entry_safe(rq, next, &rq_list, queuelist) { | |
aef1897c | 725 | if (!(rq->rq_flags & (RQF_SOFTBARRIER | RQF_DONTPREP))) |
6fca6a61 CH |
726 | continue; |
727 | ||
e8064021 | 728 | rq->rq_flags &= ~RQF_SOFTBARRIER; |
6fca6a61 | 729 | list_del_init(&rq->queuelist); |
aef1897c JW |
730 | /* |
731 | * If RQF_DONTPREP, rq has contained some driver specific | |
732 | * data, so insert it to hctx dispatch list to avoid any | |
733 | * merge. | |
734 | */ | |
735 | if (rq->rq_flags & RQF_DONTPREP) | |
736 | blk_mq_request_bypass_insert(rq, false); | |
737 | else | |
738 | blk_mq_sched_insert_request(rq, true, false, false); | |
6fca6a61 CH |
739 | } |
740 | ||
741 | while (!list_empty(&rq_list)) { | |
742 | rq = list_entry(rq_list.next, struct request, queuelist); | |
743 | list_del_init(&rq->queuelist); | |
9e97d295 | 744 | blk_mq_sched_insert_request(rq, false, false, false); |
6fca6a61 CH |
745 | } |
746 | ||
52d7f1b5 | 747 | blk_mq_run_hw_queues(q, false); |
6fca6a61 CH |
748 | } |
749 | ||
2b053aca BVA |
750 | void blk_mq_add_to_requeue_list(struct request *rq, bool at_head, |
751 | bool kick_requeue_list) | |
6fca6a61 CH |
752 | { |
753 | struct request_queue *q = rq->q; | |
754 | unsigned long flags; | |
755 | ||
756 | /* | |
757 | * We abuse this flag that is otherwise used by the I/O scheduler to | |
ff821d27 | 758 | * request head insertion from the workqueue. |
6fca6a61 | 759 | */ |
e8064021 | 760 | BUG_ON(rq->rq_flags & RQF_SOFTBARRIER); |
6fca6a61 CH |
761 | |
762 | spin_lock_irqsave(&q->requeue_lock, flags); | |
763 | if (at_head) { | |
e8064021 | 764 | rq->rq_flags |= RQF_SOFTBARRIER; |
6fca6a61 CH |
765 | list_add(&rq->queuelist, &q->requeue_list); |
766 | } else { | |
767 | list_add_tail(&rq->queuelist, &q->requeue_list); | |
768 | } | |
769 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
2b053aca BVA |
770 | |
771 | if (kick_requeue_list) | |
772 | blk_mq_kick_requeue_list(q); | |
6fca6a61 | 773 | } |
6fca6a61 CH |
774 | |
775 | void blk_mq_kick_requeue_list(struct request_queue *q) | |
776 | { | |
ae943d20 | 777 | kblockd_mod_delayed_work_on(WORK_CPU_UNBOUND, &q->requeue_work, 0); |
6fca6a61 CH |
778 | } |
779 | EXPORT_SYMBOL(blk_mq_kick_requeue_list); | |
780 | ||
2849450a MS |
781 | void blk_mq_delay_kick_requeue_list(struct request_queue *q, |
782 | unsigned long msecs) | |
783 | { | |
d4acf365 BVA |
784 | kblockd_mod_delayed_work_on(WORK_CPU_UNBOUND, &q->requeue_work, |
785 | msecs_to_jiffies(msecs)); | |
2849450a MS |
786 | } |
787 | EXPORT_SYMBOL(blk_mq_delay_kick_requeue_list); | |
788 | ||
0e62f51f JA |
789 | struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag) |
790 | { | |
88c7b2b7 JA |
791 | if (tag < tags->nr_tags) { |
792 | prefetch(tags->rqs[tag]); | |
4ee86bab | 793 | return tags->rqs[tag]; |
88c7b2b7 | 794 | } |
4ee86bab HR |
795 | |
796 | return NULL; | |
24d2f903 CH |
797 | } |
798 | EXPORT_SYMBOL(blk_mq_tag_to_rq); | |
799 | ||
3c94d83c JA |
800 | static bool blk_mq_rq_inflight(struct blk_mq_hw_ctx *hctx, struct request *rq, |
801 | void *priv, bool reserved) | |
ae879912 JA |
802 | { |
803 | /* | |
3c94d83c JA |
804 | * If we find a request that is inflight and the queue matches, |
805 | * we know the queue is busy. Return false to stop the iteration. | |
ae879912 | 806 | */ |
3c94d83c | 807 | if (rq->state == MQ_RQ_IN_FLIGHT && rq->q == hctx->queue) { |
ae879912 JA |
808 | bool *busy = priv; |
809 | ||
810 | *busy = true; | |
811 | return false; | |
812 | } | |
813 | ||
814 | return true; | |
815 | } | |
816 | ||
3c94d83c | 817 | bool blk_mq_queue_inflight(struct request_queue *q) |
ae879912 JA |
818 | { |
819 | bool busy = false; | |
820 | ||
3c94d83c | 821 | blk_mq_queue_tag_busy_iter(q, blk_mq_rq_inflight, &busy); |
ae879912 JA |
822 | return busy; |
823 | } | |
3c94d83c | 824 | EXPORT_SYMBOL_GPL(blk_mq_queue_inflight); |
ae879912 | 825 | |
358f70da | 826 | static void blk_mq_rq_timed_out(struct request *req, bool reserved) |
320ae51f | 827 | { |
da661267 | 828 | req->rq_flags |= RQF_TIMED_OUT; |
d1210d5a CH |
829 | if (req->q->mq_ops->timeout) { |
830 | enum blk_eh_timer_return ret; | |
831 | ||
832 | ret = req->q->mq_ops->timeout(req, reserved); | |
833 | if (ret == BLK_EH_DONE) | |
834 | return; | |
835 | WARN_ON_ONCE(ret != BLK_EH_RESET_TIMER); | |
46f92d42 | 836 | } |
d1210d5a CH |
837 | |
838 | blk_add_timer(req); | |
87ee7b11 | 839 | } |
5b3f25fc | 840 | |
12f5b931 | 841 | static bool blk_mq_req_expired(struct request *rq, unsigned long *next) |
81481eb4 | 842 | { |
12f5b931 | 843 | unsigned long deadline; |
87ee7b11 | 844 | |
12f5b931 KB |
845 | if (blk_mq_rq_state(rq) != MQ_RQ_IN_FLIGHT) |
846 | return false; | |
da661267 CH |
847 | if (rq->rq_flags & RQF_TIMED_OUT) |
848 | return false; | |
a7af0af3 | 849 | |
079076b3 | 850 | deadline = READ_ONCE(rq->deadline); |
12f5b931 KB |
851 | if (time_after_eq(jiffies, deadline)) |
852 | return true; | |
a7af0af3 | 853 | |
12f5b931 KB |
854 | if (*next == 0) |
855 | *next = deadline; | |
856 | else if (time_after(*next, deadline)) | |
857 | *next = deadline; | |
858 | return false; | |
87ee7b11 JA |
859 | } |
860 | ||
7baa8572 | 861 | static bool blk_mq_check_expired(struct blk_mq_hw_ctx *hctx, |
1d9bd516 TH |
862 | struct request *rq, void *priv, bool reserved) |
863 | { | |
12f5b931 KB |
864 | unsigned long *next = priv; |
865 | ||
866 | /* | |
867 | * Just do a quick check if it is expired before locking the request in | |
868 | * so we're not unnecessarilly synchronizing across CPUs. | |
869 | */ | |
870 | if (!blk_mq_req_expired(rq, next)) | |
7baa8572 | 871 | return true; |
12f5b931 KB |
872 | |
873 | /* | |
874 | * We have reason to believe the request may be expired. Take a | |
875 | * reference on the request to lock this request lifetime into its | |
876 | * currently allocated context to prevent it from being reallocated in | |
877 | * the event the completion by-passes this timeout handler. | |
878 | * | |
879 | * If the reference was already released, then the driver beat the | |
880 | * timeout handler to posting a natural completion. | |
881 | */ | |
882 | if (!refcount_inc_not_zero(&rq->ref)) | |
7baa8572 | 883 | return true; |
12f5b931 | 884 | |
1d9bd516 | 885 | /* |
12f5b931 KB |
886 | * The request is now locked and cannot be reallocated underneath the |
887 | * timeout handler's processing. Re-verify this exact request is truly | |
888 | * expired; if it is not expired, then the request was completed and | |
889 | * reallocated as a new request. | |
1d9bd516 | 890 | */ |
12f5b931 | 891 | if (blk_mq_req_expired(rq, next)) |
1d9bd516 | 892 | blk_mq_rq_timed_out(rq, reserved); |
8d699663 YY |
893 | |
894 | if (is_flush_rq(rq, hctx)) | |
895 | rq->end_io(rq, 0); | |
896 | else if (refcount_dec_and_test(&rq->ref)) | |
12f5b931 | 897 | __blk_mq_free_request(rq); |
7baa8572 JA |
898 | |
899 | return true; | |
1d9bd516 TH |
900 | } |
901 | ||
287922eb | 902 | static void blk_mq_timeout_work(struct work_struct *work) |
320ae51f | 903 | { |
287922eb CH |
904 | struct request_queue *q = |
905 | container_of(work, struct request_queue, timeout_work); | |
12f5b931 | 906 | unsigned long next = 0; |
1d9bd516 | 907 | struct blk_mq_hw_ctx *hctx; |
81481eb4 | 908 | int i; |
320ae51f | 909 | |
71f79fb3 GKB |
910 | /* A deadlock might occur if a request is stuck requiring a |
911 | * timeout at the same time a queue freeze is waiting | |
912 | * completion, since the timeout code would not be able to | |
913 | * acquire the queue reference here. | |
914 | * | |
915 | * That's why we don't use blk_queue_enter here; instead, we use | |
916 | * percpu_ref_tryget directly, because we need to be able to | |
917 | * obtain a reference even in the short window between the queue | |
918 | * starting to freeze, by dropping the first reference in | |
1671d522 | 919 | * blk_freeze_queue_start, and the moment the last request is |
71f79fb3 GKB |
920 | * consumed, marked by the instant q_usage_counter reaches |
921 | * zero. | |
922 | */ | |
923 | if (!percpu_ref_tryget(&q->q_usage_counter)) | |
287922eb CH |
924 | return; |
925 | ||
12f5b931 | 926 | blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &next); |
320ae51f | 927 | |
12f5b931 KB |
928 | if (next != 0) { |
929 | mod_timer(&q->timeout, next); | |
0d2602ca | 930 | } else { |
fcd36c36 BVA |
931 | /* |
932 | * Request timeouts are handled as a forward rolling timer. If | |
933 | * we end up here it means that no requests are pending and | |
934 | * also that no request has been pending for a while. Mark | |
935 | * each hctx as idle. | |
936 | */ | |
f054b56c ML |
937 | queue_for_each_hw_ctx(q, hctx, i) { |
938 | /* the hctx may be unmapped, so check it here */ | |
939 | if (blk_mq_hw_queue_mapped(hctx)) | |
940 | blk_mq_tag_idle(hctx); | |
941 | } | |
0d2602ca | 942 | } |
287922eb | 943 | blk_queue_exit(q); |
320ae51f JA |
944 | } |
945 | ||
88459642 OS |
946 | struct flush_busy_ctx_data { |
947 | struct blk_mq_hw_ctx *hctx; | |
948 | struct list_head *list; | |
949 | }; | |
950 | ||
951 | static bool flush_busy_ctx(struct sbitmap *sb, unsigned int bitnr, void *data) | |
952 | { | |
953 | struct flush_busy_ctx_data *flush_data = data; | |
954 | struct blk_mq_hw_ctx *hctx = flush_data->hctx; | |
955 | struct blk_mq_ctx *ctx = hctx->ctxs[bitnr]; | |
c16d6b5a | 956 | enum hctx_type type = hctx->type; |
88459642 | 957 | |
88459642 | 958 | spin_lock(&ctx->lock); |
c16d6b5a | 959 | list_splice_tail_init(&ctx->rq_lists[type], flush_data->list); |
e9a99a63 | 960 | sbitmap_clear_bit(sb, bitnr); |
88459642 OS |
961 | spin_unlock(&ctx->lock); |
962 | return true; | |
963 | } | |
964 | ||
1429d7c9 JA |
965 | /* |
966 | * Process software queues that have been marked busy, splicing them | |
967 | * to the for-dispatch | |
968 | */ | |
2c3ad667 | 969 | void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) |
1429d7c9 | 970 | { |
88459642 OS |
971 | struct flush_busy_ctx_data data = { |
972 | .hctx = hctx, | |
973 | .list = list, | |
974 | }; | |
1429d7c9 | 975 | |
88459642 | 976 | sbitmap_for_each_set(&hctx->ctx_map, flush_busy_ctx, &data); |
1429d7c9 | 977 | } |
2c3ad667 | 978 | EXPORT_SYMBOL_GPL(blk_mq_flush_busy_ctxs); |
1429d7c9 | 979 | |
b347689f ML |
980 | struct dispatch_rq_data { |
981 | struct blk_mq_hw_ctx *hctx; | |
982 | struct request *rq; | |
983 | }; | |
984 | ||
985 | static bool dispatch_rq_from_ctx(struct sbitmap *sb, unsigned int bitnr, | |
986 | void *data) | |
987 | { | |
988 | struct dispatch_rq_data *dispatch_data = data; | |
989 | struct blk_mq_hw_ctx *hctx = dispatch_data->hctx; | |
990 | struct blk_mq_ctx *ctx = hctx->ctxs[bitnr]; | |
c16d6b5a | 991 | enum hctx_type type = hctx->type; |
b347689f ML |
992 | |
993 | spin_lock(&ctx->lock); | |
c16d6b5a ML |
994 | if (!list_empty(&ctx->rq_lists[type])) { |
995 | dispatch_data->rq = list_entry_rq(ctx->rq_lists[type].next); | |
b347689f | 996 | list_del_init(&dispatch_data->rq->queuelist); |
c16d6b5a | 997 | if (list_empty(&ctx->rq_lists[type])) |
b347689f ML |
998 | sbitmap_clear_bit(sb, bitnr); |
999 | } | |
1000 | spin_unlock(&ctx->lock); | |
1001 | ||
1002 | return !dispatch_data->rq; | |
1003 | } | |
1004 | ||
1005 | struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx, | |
1006 | struct blk_mq_ctx *start) | |
1007 | { | |
f31967f0 | 1008 | unsigned off = start ? start->index_hw[hctx->type] : 0; |
b347689f ML |
1009 | struct dispatch_rq_data data = { |
1010 | .hctx = hctx, | |
1011 | .rq = NULL, | |
1012 | }; | |
1013 | ||
1014 | __sbitmap_for_each_set(&hctx->ctx_map, off, | |
1015 | dispatch_rq_from_ctx, &data); | |
1016 | ||
1017 | return data.rq; | |
1018 | } | |
1019 | ||
703fd1c0 JA |
1020 | static inline unsigned int queued_to_index(unsigned int queued) |
1021 | { | |
1022 | if (!queued) | |
1023 | return 0; | |
1429d7c9 | 1024 | |
703fd1c0 | 1025 | return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1); |
1429d7c9 JA |
1026 | } |
1027 | ||
8ab6bb9e | 1028 | bool blk_mq_get_driver_tag(struct request *rq) |
bd166ef1 JA |
1029 | { |
1030 | struct blk_mq_alloc_data data = { | |
1031 | .q = rq->q, | |
ea4f995e | 1032 | .hctx = rq->mq_hctx, |
8ab6bb9e | 1033 | .flags = BLK_MQ_REQ_NOWAIT, |
f9afca4d | 1034 | .cmd_flags = rq->cmd_flags, |
bd166ef1 | 1035 | }; |
d263ed99 | 1036 | bool shared; |
5feeacdd | 1037 | |
81380ca1 OS |
1038 | if (rq->tag != -1) |
1039 | goto done; | |
bd166ef1 | 1040 | |
415b806d SG |
1041 | if (blk_mq_tag_is_reserved(data.hctx->sched_tags, rq->internal_tag)) |
1042 | data.flags |= BLK_MQ_REQ_RESERVED; | |
1043 | ||
d263ed99 | 1044 | shared = blk_mq_tag_busy(data.hctx); |
bd166ef1 JA |
1045 | rq->tag = blk_mq_get_tag(&data); |
1046 | if (rq->tag >= 0) { | |
d263ed99 | 1047 | if (shared) { |
200e86b3 JA |
1048 | rq->rq_flags |= RQF_MQ_INFLIGHT; |
1049 | atomic_inc(&data.hctx->nr_active); | |
1050 | } | |
bd166ef1 | 1051 | data.hctx->tags->rqs[rq->tag] = rq; |
bd166ef1 JA |
1052 | } |
1053 | ||
81380ca1 | 1054 | done: |
81380ca1 | 1055 | return rq->tag != -1; |
bd166ef1 JA |
1056 | } |
1057 | ||
eb619fdb JA |
1058 | static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode, |
1059 | int flags, void *key) | |
da55f2cc OS |
1060 | { |
1061 | struct blk_mq_hw_ctx *hctx; | |
1062 | ||
1063 | hctx = container_of(wait, struct blk_mq_hw_ctx, dispatch_wait); | |
1064 | ||
5815839b | 1065 | spin_lock(&hctx->dispatch_wait_lock); |
e8618575 JA |
1066 | if (!list_empty(&wait->entry)) { |
1067 | struct sbitmap_queue *sbq; | |
1068 | ||
1069 | list_del_init(&wait->entry); | |
1070 | sbq = &hctx->tags->bitmap_tags; | |
1071 | atomic_dec(&sbq->ws_active); | |
1072 | } | |
5815839b ML |
1073 | spin_unlock(&hctx->dispatch_wait_lock); |
1074 | ||
da55f2cc OS |
1075 | blk_mq_run_hw_queue(hctx, true); |
1076 | return 1; | |
1077 | } | |
1078 | ||
f906a6a0 JA |
1079 | /* |
1080 | * Mark us waiting for a tag. For shared tags, this involves hooking us into | |
ee3e4de5 BVA |
1081 | * the tag wakeups. For non-shared tags, we can simply mark us needing a |
1082 | * restart. For both cases, take care to check the condition again after | |
f906a6a0 JA |
1083 | * marking us as waiting. |
1084 | */ | |
2278d69f | 1085 | static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx *hctx, |
f906a6a0 | 1086 | struct request *rq) |
da55f2cc | 1087 | { |
e8618575 | 1088 | struct sbitmap_queue *sbq = &hctx->tags->bitmap_tags; |
5815839b | 1089 | struct wait_queue_head *wq; |
f906a6a0 JA |
1090 | wait_queue_entry_t *wait; |
1091 | bool ret; | |
da55f2cc | 1092 | |
2278d69f | 1093 | if (!(hctx->flags & BLK_MQ_F_TAG_SHARED)) { |
684b7324 | 1094 | blk_mq_sched_mark_restart_hctx(hctx); |
f906a6a0 | 1095 | |
c27d53fb BVA |
1096 | /* |
1097 | * It's possible that a tag was freed in the window between the | |
1098 | * allocation failure and adding the hardware queue to the wait | |
1099 | * queue. | |
1100 | * | |
1101 | * Don't clear RESTART here, someone else could have set it. | |
1102 | * At most this will cost an extra queue run. | |
1103 | */ | |
8ab6bb9e | 1104 | return blk_mq_get_driver_tag(rq); |
eb619fdb | 1105 | } |
eb619fdb | 1106 | |
2278d69f | 1107 | wait = &hctx->dispatch_wait; |
c27d53fb BVA |
1108 | if (!list_empty_careful(&wait->entry)) |
1109 | return false; | |
1110 | ||
e8618575 | 1111 | wq = &bt_wait_ptr(sbq, hctx)->wait; |
5815839b ML |
1112 | |
1113 | spin_lock_irq(&wq->lock); | |
1114 | spin_lock(&hctx->dispatch_wait_lock); | |
c27d53fb | 1115 | if (!list_empty(&wait->entry)) { |
5815839b ML |
1116 | spin_unlock(&hctx->dispatch_wait_lock); |
1117 | spin_unlock_irq(&wq->lock); | |
c27d53fb | 1118 | return false; |
eb619fdb JA |
1119 | } |
1120 | ||
e8618575 | 1121 | atomic_inc(&sbq->ws_active); |
5815839b ML |
1122 | wait->flags &= ~WQ_FLAG_EXCLUSIVE; |
1123 | __add_wait_queue(wq, wait); | |
c27d53fb | 1124 | |
da55f2cc | 1125 | /* |
eb619fdb JA |
1126 | * It's possible that a tag was freed in the window between the |
1127 | * allocation failure and adding the hardware queue to the wait | |
1128 | * queue. | |
da55f2cc | 1129 | */ |
8ab6bb9e | 1130 | ret = blk_mq_get_driver_tag(rq); |
c27d53fb | 1131 | if (!ret) { |
5815839b ML |
1132 | spin_unlock(&hctx->dispatch_wait_lock); |
1133 | spin_unlock_irq(&wq->lock); | |
c27d53fb | 1134 | return false; |
eb619fdb | 1135 | } |
c27d53fb BVA |
1136 | |
1137 | /* | |
1138 | * We got a tag, remove ourselves from the wait queue to ensure | |
1139 | * someone else gets the wakeup. | |
1140 | */ | |
c27d53fb | 1141 | list_del_init(&wait->entry); |
e8618575 | 1142 | atomic_dec(&sbq->ws_active); |
5815839b ML |
1143 | spin_unlock(&hctx->dispatch_wait_lock); |
1144 | spin_unlock_irq(&wq->lock); | |
c27d53fb BVA |
1145 | |
1146 | return true; | |
da55f2cc OS |
1147 | } |
1148 | ||
6e768717 ML |
1149 | #define BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT 8 |
1150 | #define BLK_MQ_DISPATCH_BUSY_EWMA_FACTOR 4 | |
1151 | /* | |
1152 | * Update dispatch busy with the Exponential Weighted Moving Average(EWMA): | |
1153 | * - EWMA is one simple way to compute running average value | |
1154 | * - weight(7/8 and 1/8) is applied so that it can decrease exponentially | |
1155 | * - take 4 as factor for avoiding to get too small(0) result, and this | |
1156 | * factor doesn't matter because EWMA decreases exponentially | |
1157 | */ | |
1158 | static void blk_mq_update_dispatch_busy(struct blk_mq_hw_ctx *hctx, bool busy) | |
1159 | { | |
1160 | unsigned int ewma; | |
1161 | ||
1162 | if (hctx->queue->elevator) | |
1163 | return; | |
1164 | ||
1165 | ewma = hctx->dispatch_busy; | |
1166 | ||
1167 | if (!ewma && !busy) | |
1168 | return; | |
1169 | ||
1170 | ewma *= BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT - 1; | |
1171 | if (busy) | |
1172 | ewma += 1 << BLK_MQ_DISPATCH_BUSY_EWMA_FACTOR; | |
1173 | ewma /= BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT; | |
1174 | ||
1175 | hctx->dispatch_busy = ewma; | |
1176 | } | |
1177 | ||
86ff7c2a ML |
1178 | #define BLK_MQ_RESOURCE_DELAY 3 /* ms units */ |
1179 | ||
1f57f8d4 JA |
1180 | /* |
1181 | * Returns true if we did some work AND can potentially do more. | |
1182 | */ | |
de148297 | 1183 | bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list, |
eb619fdb | 1184 | bool got_budget) |
320ae51f | 1185 | { |
81380ca1 | 1186 | struct blk_mq_hw_ctx *hctx; |
6d6f167c | 1187 | struct request *rq, *nxt; |
eb619fdb | 1188 | bool no_tag = false; |
fc17b653 | 1189 | int errors, queued; |
86ff7c2a | 1190 | blk_status_t ret = BLK_STS_OK; |
320ae51f | 1191 | |
81380ca1 OS |
1192 | if (list_empty(list)) |
1193 | return false; | |
1194 | ||
de148297 ML |
1195 | WARN_ON(!list_is_singular(list) && got_budget); |
1196 | ||
320ae51f JA |
1197 | /* |
1198 | * Now process all the entries, sending them to the driver. | |
1199 | */ | |
93efe981 | 1200 | errors = queued = 0; |
81380ca1 | 1201 | do { |
74c45052 | 1202 | struct blk_mq_queue_data bd; |
320ae51f | 1203 | |
f04c3df3 | 1204 | rq = list_first_entry(list, struct request, queuelist); |
0bca799b | 1205 | |
ea4f995e | 1206 | hctx = rq->mq_hctx; |
0bca799b ML |
1207 | if (!got_budget && !blk_mq_get_dispatch_budget(hctx)) |
1208 | break; | |
1209 | ||
8ab6bb9e | 1210 | if (!blk_mq_get_driver_tag(rq)) { |
3c782d67 | 1211 | /* |
da55f2cc | 1212 | * The initial allocation attempt failed, so we need to |
eb619fdb JA |
1213 | * rerun the hardware queue when a tag is freed. The |
1214 | * waitqueue takes care of that. If the queue is run | |
1215 | * before we add this entry back on the dispatch list, | |
1216 | * we'll re-run it below. | |
3c782d67 | 1217 | */ |
2278d69f | 1218 | if (!blk_mq_mark_tag_wait(hctx, rq)) { |
0bca799b | 1219 | blk_mq_put_dispatch_budget(hctx); |
f906a6a0 JA |
1220 | /* |
1221 | * For non-shared tags, the RESTART check | |
1222 | * will suffice. | |
1223 | */ | |
1224 | if (hctx->flags & BLK_MQ_F_TAG_SHARED) | |
1225 | no_tag = true; | |
de148297 ML |
1226 | break; |
1227 | } | |
1228 | } | |
1229 | ||
320ae51f | 1230 | list_del_init(&rq->queuelist); |
320ae51f | 1231 | |
74c45052 | 1232 | bd.rq = rq; |
113285b4 JA |
1233 | |
1234 | /* | |
1235 | * Flag last if we have no more requests, or if we have more | |
1236 | * but can't assign a driver tag to it. | |
1237 | */ | |
1238 | if (list_empty(list)) | |
1239 | bd.last = true; | |
1240 | else { | |
113285b4 | 1241 | nxt = list_first_entry(list, struct request, queuelist); |
8ab6bb9e | 1242 | bd.last = !blk_mq_get_driver_tag(nxt); |
113285b4 | 1243 | } |
74c45052 JA |
1244 | |
1245 | ret = q->mq_ops->queue_rq(hctx, &bd); | |
86ff7c2a | 1246 | if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) { |
6d6f167c JW |
1247 | /* |
1248 | * If an I/O scheduler has been configured and we got a | |
ff821d27 JA |
1249 | * driver tag for the next request already, free it |
1250 | * again. | |
6d6f167c JW |
1251 | */ |
1252 | if (!list_empty(list)) { | |
1253 | nxt = list_first_entry(list, struct request, queuelist); | |
1254 | blk_mq_put_driver_tag(nxt); | |
1255 | } | |
f04c3df3 | 1256 | list_add(&rq->queuelist, list); |
ed0791b2 | 1257 | __blk_mq_requeue_request(rq); |
320ae51f | 1258 | break; |
fc17b653 CH |
1259 | } |
1260 | ||
1261 | if (unlikely(ret != BLK_STS_OK)) { | |
93efe981 | 1262 | errors++; |
2a842aca | 1263 | blk_mq_end_request(rq, BLK_STS_IOERR); |
fc17b653 | 1264 | continue; |
320ae51f JA |
1265 | } |
1266 | ||
fc17b653 | 1267 | queued++; |
81380ca1 | 1268 | } while (!list_empty(list)); |
320ae51f | 1269 | |
703fd1c0 | 1270 | hctx->dispatched[queued_to_index(queued)]++; |
320ae51f JA |
1271 | |
1272 | /* | |
1273 | * Any items that need requeuing? Stuff them into hctx->dispatch, | |
1274 | * that is where we will continue on next queue run. | |
1275 | */ | |
f04c3df3 | 1276 | if (!list_empty(list)) { |
86ff7c2a ML |
1277 | bool needs_restart; |
1278 | ||
d666ba98 JA |
1279 | /* |
1280 | * If we didn't flush the entire list, we could have told | |
1281 | * the driver there was more coming, but that turned out to | |
1282 | * be a lie. | |
1283 | */ | |
1284 | if (q->mq_ops->commit_rqs) | |
1285 | q->mq_ops->commit_rqs(hctx); | |
1286 | ||
320ae51f | 1287 | spin_lock(&hctx->lock); |
c13660a0 | 1288 | list_splice_init(list, &hctx->dispatch); |
320ae51f | 1289 | spin_unlock(&hctx->lock); |
f04c3df3 | 1290 | |
9ba52e58 | 1291 | /* |
710c785f BVA |
1292 | * If SCHED_RESTART was set by the caller of this function and |
1293 | * it is no longer set that means that it was cleared by another | |
1294 | * thread and hence that a queue rerun is needed. | |
9ba52e58 | 1295 | * |
eb619fdb JA |
1296 | * If 'no_tag' is set, that means that we failed getting |
1297 | * a driver tag with an I/O scheduler attached. If our dispatch | |
1298 | * waitqueue is no longer active, ensure that we run the queue | |
1299 | * AFTER adding our entries back to the list. | |
bd166ef1 | 1300 | * |
710c785f BVA |
1301 | * If no I/O scheduler has been configured it is possible that |
1302 | * the hardware queue got stopped and restarted before requests | |
1303 | * were pushed back onto the dispatch list. Rerun the queue to | |
1304 | * avoid starvation. Notes: | |
1305 | * - blk_mq_run_hw_queue() checks whether or not a queue has | |
1306 | * been stopped before rerunning a queue. | |
1307 | * - Some but not all block drivers stop a queue before | |
fc17b653 | 1308 | * returning BLK_STS_RESOURCE. Two exceptions are scsi-mq |
710c785f | 1309 | * and dm-rq. |
86ff7c2a ML |
1310 | * |
1311 | * If driver returns BLK_STS_RESOURCE and SCHED_RESTART | |
1312 | * bit is set, run queue after a delay to avoid IO stalls | |
1313 | * that could otherwise occur if the queue is idle. | |
bd166ef1 | 1314 | */ |
86ff7c2a ML |
1315 | needs_restart = blk_mq_sched_needs_restart(hctx); |
1316 | if (!needs_restart || | |
eb619fdb | 1317 | (no_tag && list_empty_careful(&hctx->dispatch_wait.entry))) |
bd166ef1 | 1318 | blk_mq_run_hw_queue(hctx, true); |
86ff7c2a ML |
1319 | else if (needs_restart && (ret == BLK_STS_RESOURCE)) |
1320 | blk_mq_delay_run_hw_queue(hctx, BLK_MQ_RESOURCE_DELAY); | |
1f57f8d4 | 1321 | |
6e768717 | 1322 | blk_mq_update_dispatch_busy(hctx, true); |
1f57f8d4 | 1323 | return false; |
6e768717 ML |
1324 | } else |
1325 | blk_mq_update_dispatch_busy(hctx, false); | |
f04c3df3 | 1326 | |
1f57f8d4 JA |
1327 | /* |
1328 | * If the host/device is unable to accept more work, inform the | |
1329 | * caller of that. | |
1330 | */ | |
1331 | if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) | |
1332 | return false; | |
1333 | ||
93efe981 | 1334 | return (queued + errors) != 0; |
f04c3df3 JA |
1335 | } |
1336 | ||
6a83e74d BVA |
1337 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) |
1338 | { | |
1339 | int srcu_idx; | |
1340 | ||
b7a71e66 JA |
1341 | /* |
1342 | * We should be running this queue from one of the CPUs that | |
1343 | * are mapped to it. | |
7df938fb ML |
1344 | * |
1345 | * There are at least two related races now between setting | |
1346 | * hctx->next_cpu from blk_mq_hctx_next_cpu() and running | |
1347 | * __blk_mq_run_hw_queue(): | |
1348 | * | |
1349 | * - hctx->next_cpu is found offline in blk_mq_hctx_next_cpu(), | |
1350 | * but later it becomes online, then this warning is harmless | |
1351 | * at all | |
1352 | * | |
1353 | * - hctx->next_cpu is found online in blk_mq_hctx_next_cpu(), | |
1354 | * but later it becomes offline, then the warning can't be | |
1355 | * triggered, and we depend on blk-mq timeout handler to | |
1356 | * handle dispatched requests to this hctx | |
b7a71e66 | 1357 | */ |
7df938fb ML |
1358 | if (!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) && |
1359 | cpu_online(hctx->next_cpu)) { | |
1360 | printk(KERN_WARNING "run queue from wrong CPU %d, hctx %s\n", | |
1361 | raw_smp_processor_id(), | |
1362 | cpumask_empty(hctx->cpumask) ? "inactive": "active"); | |
1363 | dump_stack(); | |
1364 | } | |
6a83e74d | 1365 | |
b7a71e66 JA |
1366 | /* |
1367 | * We can't run the queue inline with ints disabled. Ensure that | |
1368 | * we catch bad users of this early. | |
1369 | */ | |
1370 | WARN_ON_ONCE(in_interrupt()); | |
1371 | ||
04ced159 | 1372 | might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING); |
bf4907c0 | 1373 | |
04ced159 JA |
1374 | hctx_lock(hctx, &srcu_idx); |
1375 | blk_mq_sched_dispatch_requests(hctx); | |
1376 | hctx_unlock(hctx, srcu_idx); | |
6a83e74d BVA |
1377 | } |
1378 | ||
f82ddf19 ML |
1379 | static inline int blk_mq_first_mapped_cpu(struct blk_mq_hw_ctx *hctx) |
1380 | { | |
1381 | int cpu = cpumask_first_and(hctx->cpumask, cpu_online_mask); | |
1382 | ||
1383 | if (cpu >= nr_cpu_ids) | |
1384 | cpu = cpumask_first(hctx->cpumask); | |
1385 | return cpu; | |
1386 | } | |
1387 | ||
506e931f JA |
1388 | /* |
1389 | * It'd be great if the workqueue API had a way to pass | |
1390 | * in a mask and had some smarts for more clever placement. | |
1391 | * For now we just round-robin here, switching for every | |
1392 | * BLK_MQ_CPU_WORK_BATCH queued items. | |
1393 | */ | |
1394 | static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) | |
1395 | { | |
7bed4595 | 1396 | bool tried = false; |
476f8c98 | 1397 | int next_cpu = hctx->next_cpu; |
7bed4595 | 1398 | |
b657d7e6 CH |
1399 | if (hctx->queue->nr_hw_queues == 1) |
1400 | return WORK_CPU_UNBOUND; | |
506e931f JA |
1401 | |
1402 | if (--hctx->next_cpu_batch <= 0) { | |
7bed4595 | 1403 | select_cpu: |
476f8c98 | 1404 | next_cpu = cpumask_next_and(next_cpu, hctx->cpumask, |
20e4d813 | 1405 | cpu_online_mask); |
506e931f | 1406 | if (next_cpu >= nr_cpu_ids) |
f82ddf19 | 1407 | next_cpu = blk_mq_first_mapped_cpu(hctx); |
506e931f JA |
1408 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; |
1409 | } | |
1410 | ||
7bed4595 ML |
1411 | /* |
1412 | * Do unbound schedule if we can't find a online CPU for this hctx, | |
1413 | * and it should only happen in the path of handling CPU DEAD. | |
1414 | */ | |
476f8c98 | 1415 | if (!cpu_online(next_cpu)) { |
7bed4595 ML |
1416 | if (!tried) { |
1417 | tried = true; | |
1418 | goto select_cpu; | |
1419 | } | |
1420 | ||
1421 | /* | |
1422 | * Make sure to re-select CPU next time once after CPUs | |
1423 | * in hctx->cpumask become online again. | |
1424 | */ | |
476f8c98 | 1425 | hctx->next_cpu = next_cpu; |
7bed4595 ML |
1426 | hctx->next_cpu_batch = 1; |
1427 | return WORK_CPU_UNBOUND; | |
1428 | } | |
476f8c98 ML |
1429 | |
1430 | hctx->next_cpu = next_cpu; | |
1431 | return next_cpu; | |
506e931f JA |
1432 | } |
1433 | ||
7587a5ae BVA |
1434 | static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async, |
1435 | unsigned long msecs) | |
320ae51f | 1436 | { |
5435c023 | 1437 | if (unlikely(blk_mq_hctx_stopped(hctx))) |
320ae51f JA |
1438 | return; |
1439 | ||
1b792f2f | 1440 | if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) { |
2a90d4aa PB |
1441 | int cpu = get_cpu(); |
1442 | if (cpumask_test_cpu(cpu, hctx->cpumask)) { | |
398205b8 | 1443 | __blk_mq_run_hw_queue(hctx); |
2a90d4aa | 1444 | put_cpu(); |
398205b8 PB |
1445 | return; |
1446 | } | |
e4043dcf | 1447 | |
2a90d4aa | 1448 | put_cpu(); |
e4043dcf | 1449 | } |
398205b8 | 1450 | |
ae943d20 BVA |
1451 | kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work, |
1452 | msecs_to_jiffies(msecs)); | |
7587a5ae BVA |
1453 | } |
1454 | ||
1455 | void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) | |
1456 | { | |
1457 | __blk_mq_delay_run_hw_queue(hctx, true, msecs); | |
1458 | } | |
1459 | EXPORT_SYMBOL(blk_mq_delay_run_hw_queue); | |
1460 | ||
79f720a7 | 1461 | bool blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
7587a5ae | 1462 | { |
24f5a90f ML |
1463 | int srcu_idx; |
1464 | bool need_run; | |
1465 | ||
1466 | /* | |
1467 | * When queue is quiesced, we may be switching io scheduler, or | |
1468 | * updating nr_hw_queues, or other things, and we can't run queue | |
1469 | * any more, even __blk_mq_hctx_has_pending() can't be called safely. | |
1470 | * | |
1471 | * And queue will be rerun in blk_mq_unquiesce_queue() if it is | |
1472 | * quiesced. | |
1473 | */ | |
04ced159 JA |
1474 | hctx_lock(hctx, &srcu_idx); |
1475 | need_run = !blk_queue_quiesced(hctx->queue) && | |
1476 | blk_mq_hctx_has_pending(hctx); | |
1477 | hctx_unlock(hctx, srcu_idx); | |
24f5a90f ML |
1478 | |
1479 | if (need_run) { | |
79f720a7 JA |
1480 | __blk_mq_delay_run_hw_queue(hctx, async, 0); |
1481 | return true; | |
1482 | } | |
1483 | ||
1484 | return false; | |
320ae51f | 1485 | } |
5b727272 | 1486 | EXPORT_SYMBOL(blk_mq_run_hw_queue); |
320ae51f | 1487 | |
b94ec296 | 1488 | void blk_mq_run_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
1489 | { |
1490 | struct blk_mq_hw_ctx *hctx; | |
1491 | int i; | |
1492 | ||
1493 | queue_for_each_hw_ctx(q, hctx, i) { | |
79f720a7 | 1494 | if (blk_mq_hctx_stopped(hctx)) |
320ae51f JA |
1495 | continue; |
1496 | ||
b94ec296 | 1497 | blk_mq_run_hw_queue(hctx, async); |
320ae51f JA |
1498 | } |
1499 | } | |
b94ec296 | 1500 | EXPORT_SYMBOL(blk_mq_run_hw_queues); |
320ae51f | 1501 | |
fd001443 BVA |
1502 | /** |
1503 | * blk_mq_queue_stopped() - check whether one or more hctxs have been stopped | |
1504 | * @q: request queue. | |
1505 | * | |
1506 | * The caller is responsible for serializing this function against | |
1507 | * blk_mq_{start,stop}_hw_queue(). | |
1508 | */ | |
1509 | bool blk_mq_queue_stopped(struct request_queue *q) | |
1510 | { | |
1511 | struct blk_mq_hw_ctx *hctx; | |
1512 | int i; | |
1513 | ||
1514 | queue_for_each_hw_ctx(q, hctx, i) | |
1515 | if (blk_mq_hctx_stopped(hctx)) | |
1516 | return true; | |
1517 | ||
1518 | return false; | |
1519 | } | |
1520 | EXPORT_SYMBOL(blk_mq_queue_stopped); | |
1521 | ||
39a70c76 ML |
1522 | /* |
1523 | * This function is often used for pausing .queue_rq() by driver when | |
1524 | * there isn't enough resource or some conditions aren't satisfied, and | |
4d606219 | 1525 | * BLK_STS_RESOURCE is usually returned. |
39a70c76 ML |
1526 | * |
1527 | * We do not guarantee that dispatch can be drained or blocked | |
1528 | * after blk_mq_stop_hw_queue() returns. Please use | |
1529 | * blk_mq_quiesce_queue() for that requirement. | |
1530 | */ | |
2719aa21 JA |
1531 | void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx) |
1532 | { | |
641a9ed6 | 1533 | cancel_delayed_work(&hctx->run_work); |
280d45f6 | 1534 | |
641a9ed6 | 1535 | set_bit(BLK_MQ_S_STOPPED, &hctx->state); |
2719aa21 | 1536 | } |
641a9ed6 | 1537 | EXPORT_SYMBOL(blk_mq_stop_hw_queue); |
2719aa21 | 1538 | |
39a70c76 ML |
1539 | /* |
1540 | * This function is often used for pausing .queue_rq() by driver when | |
1541 | * there isn't enough resource or some conditions aren't satisfied, and | |
4d606219 | 1542 | * BLK_STS_RESOURCE is usually returned. |
39a70c76 ML |
1543 | * |
1544 | * We do not guarantee that dispatch can be drained or blocked | |
1545 | * after blk_mq_stop_hw_queues() returns. Please use | |
1546 | * blk_mq_quiesce_queue() for that requirement. | |
1547 | */ | |
2719aa21 JA |
1548 | void blk_mq_stop_hw_queues(struct request_queue *q) |
1549 | { | |
641a9ed6 ML |
1550 | struct blk_mq_hw_ctx *hctx; |
1551 | int i; | |
1552 | ||
1553 | queue_for_each_hw_ctx(q, hctx, i) | |
1554 | blk_mq_stop_hw_queue(hctx); | |
280d45f6 CH |
1555 | } |
1556 | EXPORT_SYMBOL(blk_mq_stop_hw_queues); | |
1557 | ||
320ae51f JA |
1558 | void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx) |
1559 | { | |
1560 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
e4043dcf | 1561 | |
0ffbce80 | 1562 | blk_mq_run_hw_queue(hctx, false); |
320ae51f JA |
1563 | } |
1564 | EXPORT_SYMBOL(blk_mq_start_hw_queue); | |
1565 | ||
2f268556 CH |
1566 | void blk_mq_start_hw_queues(struct request_queue *q) |
1567 | { | |
1568 | struct blk_mq_hw_ctx *hctx; | |
1569 | int i; | |
1570 | ||
1571 | queue_for_each_hw_ctx(q, hctx, i) | |
1572 | blk_mq_start_hw_queue(hctx); | |
1573 | } | |
1574 | EXPORT_SYMBOL(blk_mq_start_hw_queues); | |
1575 | ||
ae911c5e JA |
1576 | void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
1577 | { | |
1578 | if (!blk_mq_hctx_stopped(hctx)) | |
1579 | return; | |
1580 | ||
1581 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
1582 | blk_mq_run_hw_queue(hctx, async); | |
1583 | } | |
1584 | EXPORT_SYMBOL_GPL(blk_mq_start_stopped_hw_queue); | |
1585 | ||
1b4a3258 | 1586 | void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
1587 | { |
1588 | struct blk_mq_hw_ctx *hctx; | |
1589 | int i; | |
1590 | ||
ae911c5e JA |
1591 | queue_for_each_hw_ctx(q, hctx, i) |
1592 | blk_mq_start_stopped_hw_queue(hctx, async); | |
320ae51f JA |
1593 | } |
1594 | EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); | |
1595 | ||
70f4db63 | 1596 | static void blk_mq_run_work_fn(struct work_struct *work) |
320ae51f JA |
1597 | { |
1598 | struct blk_mq_hw_ctx *hctx; | |
1599 | ||
9f993737 | 1600 | hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work); |
320ae51f | 1601 | |
21c6e939 | 1602 | /* |
15fe8a90 | 1603 | * If we are stopped, don't run the queue. |
21c6e939 | 1604 | */ |
15fe8a90 | 1605 | if (test_bit(BLK_MQ_S_STOPPED, &hctx->state)) |
0196d6b4 | 1606 | return; |
7587a5ae BVA |
1607 | |
1608 | __blk_mq_run_hw_queue(hctx); | |
1609 | } | |
1610 | ||
cfd0c552 | 1611 | static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx, |
cfd0c552 ML |
1612 | struct request *rq, |
1613 | bool at_head) | |
320ae51f | 1614 | { |
e57690fe | 1615 | struct blk_mq_ctx *ctx = rq->mq_ctx; |
c16d6b5a | 1616 | enum hctx_type type = hctx->type; |
e57690fe | 1617 | |
7b607814 BVA |
1618 | lockdep_assert_held(&ctx->lock); |
1619 | ||
01b983c9 JA |
1620 | trace_block_rq_insert(hctx->queue, rq); |
1621 | ||
72a0a36e | 1622 | if (at_head) |
c16d6b5a | 1623 | list_add(&rq->queuelist, &ctx->rq_lists[type]); |
72a0a36e | 1624 | else |
c16d6b5a | 1625 | list_add_tail(&rq->queuelist, &ctx->rq_lists[type]); |
cfd0c552 | 1626 | } |
4bb659b1 | 1627 | |
2c3ad667 JA |
1628 | void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, |
1629 | bool at_head) | |
cfd0c552 ML |
1630 | { |
1631 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
1632 | ||
7b607814 BVA |
1633 | lockdep_assert_held(&ctx->lock); |
1634 | ||
e57690fe | 1635 | __blk_mq_insert_req_list(hctx, rq, at_head); |
320ae51f | 1636 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f JA |
1637 | } |
1638 | ||
157f377b JA |
1639 | /* |
1640 | * Should only be used carefully, when the caller knows we want to | |
1641 | * bypass a potential IO scheduler on the target device. | |
1642 | */ | |
b0850297 | 1643 | void blk_mq_request_bypass_insert(struct request *rq, bool run_queue) |
157f377b | 1644 | { |
ea4f995e | 1645 | struct blk_mq_hw_ctx *hctx = rq->mq_hctx; |
157f377b JA |
1646 | |
1647 | spin_lock(&hctx->lock); | |
1648 | list_add_tail(&rq->queuelist, &hctx->dispatch); | |
1649 | spin_unlock(&hctx->lock); | |
1650 | ||
b0850297 ML |
1651 | if (run_queue) |
1652 | blk_mq_run_hw_queue(hctx, false); | |
157f377b JA |
1653 | } |
1654 | ||
bd166ef1 JA |
1655 | void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, |
1656 | struct list_head *list) | |
320ae51f JA |
1657 | |
1658 | { | |
3f0cedc7 | 1659 | struct request *rq; |
c16d6b5a | 1660 | enum hctx_type type = hctx->type; |
3f0cedc7 | 1661 | |
320ae51f JA |
1662 | /* |
1663 | * preemption doesn't flush plug list, so it's possible ctx->cpu is | |
1664 | * offline now | |
1665 | */ | |
3f0cedc7 | 1666 | list_for_each_entry(rq, list, queuelist) { |
e57690fe | 1667 | BUG_ON(rq->mq_ctx != ctx); |
3f0cedc7 | 1668 | trace_block_rq_insert(hctx->queue, rq); |
320ae51f | 1669 | } |
3f0cedc7 ML |
1670 | |
1671 | spin_lock(&ctx->lock); | |
c16d6b5a | 1672 | list_splice_tail_init(list, &ctx->rq_lists[type]); |
cfd0c552 | 1673 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f | 1674 | spin_unlock(&ctx->lock); |
320ae51f JA |
1675 | } |
1676 | ||
3110fc79 | 1677 | static int plug_rq_cmp(void *priv, struct list_head *a, struct list_head *b) |
320ae51f JA |
1678 | { |
1679 | struct request *rqa = container_of(a, struct request, queuelist); | |
1680 | struct request *rqb = container_of(b, struct request, queuelist); | |
1681 | ||
3110fc79 JA |
1682 | if (rqa->mq_ctx < rqb->mq_ctx) |
1683 | return -1; | |
1684 | else if (rqa->mq_ctx > rqb->mq_ctx) | |
1685 | return 1; | |
1686 | else if (rqa->mq_hctx < rqb->mq_hctx) | |
1687 | return -1; | |
1688 | else if (rqa->mq_hctx > rqb->mq_hctx) | |
1689 | return 1; | |
1690 | ||
1691 | return blk_rq_pos(rqa) > blk_rq_pos(rqb); | |
320ae51f JA |
1692 | } |
1693 | ||
1694 | void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) | |
1695 | { | |
67cae4c9 | 1696 | struct blk_mq_hw_ctx *this_hctx; |
320ae51f JA |
1697 | struct blk_mq_ctx *this_ctx; |
1698 | struct request_queue *this_q; | |
1699 | struct request *rq; | |
1700 | LIST_HEAD(list); | |
67cae4c9 | 1701 | LIST_HEAD(rq_list); |
320ae51f JA |
1702 | unsigned int depth; |
1703 | ||
1704 | list_splice_init(&plug->mq_list, &list); | |
1705 | ||
ce5b009c JA |
1706 | if (plug->rq_count > 2 && plug->multiple_queues) |
1707 | list_sort(NULL, &list, plug_rq_cmp); | |
320ae51f | 1708 | |
bcc816df DZ |
1709 | plug->rq_count = 0; |
1710 | ||
320ae51f | 1711 | this_q = NULL; |
67cae4c9 | 1712 | this_hctx = NULL; |
320ae51f JA |
1713 | this_ctx = NULL; |
1714 | depth = 0; | |
1715 | ||
1716 | while (!list_empty(&list)) { | |
1717 | rq = list_entry_rq(list.next); | |
1718 | list_del_init(&rq->queuelist); | |
1719 | BUG_ON(!rq->q); | |
67cae4c9 JA |
1720 | if (rq->mq_hctx != this_hctx || rq->mq_ctx != this_ctx) { |
1721 | if (this_hctx) { | |
587562d0 | 1722 | trace_block_unplug(this_q, depth, !from_schedule); |
67cae4c9 JA |
1723 | blk_mq_sched_insert_requests(this_hctx, this_ctx, |
1724 | &rq_list, | |
bd166ef1 | 1725 | from_schedule); |
320ae51f JA |
1726 | } |
1727 | ||
320ae51f | 1728 | this_q = rq->q; |
67cae4c9 JA |
1729 | this_ctx = rq->mq_ctx; |
1730 | this_hctx = rq->mq_hctx; | |
320ae51f JA |
1731 | depth = 0; |
1732 | } | |
1733 | ||
1734 | depth++; | |
67cae4c9 | 1735 | list_add_tail(&rq->queuelist, &rq_list); |
320ae51f JA |
1736 | } |
1737 | ||
1738 | /* | |
67cae4c9 JA |
1739 | * If 'this_hctx' is set, we know we have entries to complete |
1740 | * on 'rq_list'. Do those. | |
320ae51f | 1741 | */ |
67cae4c9 | 1742 | if (this_hctx) { |
587562d0 | 1743 | trace_block_unplug(this_q, depth, !from_schedule); |
67cae4c9 | 1744 | blk_mq_sched_insert_requests(this_hctx, this_ctx, &rq_list, |
bd166ef1 | 1745 | from_schedule); |
320ae51f JA |
1746 | } |
1747 | } | |
1748 | ||
14ccb66b CH |
1749 | static void blk_mq_bio_to_request(struct request *rq, struct bio *bio, |
1750 | unsigned int nr_segs) | |
320ae51f | 1751 | { |
f924cdde CH |
1752 | if (bio->bi_opf & REQ_RAHEAD) |
1753 | rq->cmd_flags |= REQ_FAILFAST_MASK; | |
1754 | ||
1755 | rq->__sector = bio->bi_iter.bi_sector; | |
1756 | rq->write_hint = bio->bi_write_hint; | |
14ccb66b | 1757 | blk_rq_bio_prep(rq, bio, nr_segs); |
4b570521 | 1758 | |
6e85eaf3 | 1759 | blk_account_io_start(rq, true); |
320ae51f JA |
1760 | } |
1761 | ||
0f95549c MS |
1762 | static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx, |
1763 | struct request *rq, | |
be94f058 | 1764 | blk_qc_t *cookie, bool last) |
f984df1f | 1765 | { |
f984df1f | 1766 | struct request_queue *q = rq->q; |
f984df1f SL |
1767 | struct blk_mq_queue_data bd = { |
1768 | .rq = rq, | |
be94f058 | 1769 | .last = last, |
f984df1f | 1770 | }; |
bd166ef1 | 1771 | blk_qc_t new_cookie; |
f06345ad | 1772 | blk_status_t ret; |
0f95549c MS |
1773 | |
1774 | new_cookie = request_to_qc_t(hctx, rq); | |
1775 | ||
1776 | /* | |
1777 | * For OK queue, we are done. For error, caller may kill it. | |
1778 | * Any other error (busy), just add it to our list as we | |
1779 | * previously would have done. | |
1780 | */ | |
1781 | ret = q->mq_ops->queue_rq(hctx, &bd); | |
1782 | switch (ret) { | |
1783 | case BLK_STS_OK: | |
6ce3dd6e | 1784 | blk_mq_update_dispatch_busy(hctx, false); |
0f95549c MS |
1785 | *cookie = new_cookie; |
1786 | break; | |
1787 | case BLK_STS_RESOURCE: | |
86ff7c2a | 1788 | case BLK_STS_DEV_RESOURCE: |
6ce3dd6e | 1789 | blk_mq_update_dispatch_busy(hctx, true); |
0f95549c MS |
1790 | __blk_mq_requeue_request(rq); |
1791 | break; | |
1792 | default: | |
6ce3dd6e | 1793 | blk_mq_update_dispatch_busy(hctx, false); |
0f95549c MS |
1794 | *cookie = BLK_QC_T_NONE; |
1795 | break; | |
1796 | } | |
1797 | ||
1798 | return ret; | |
1799 | } | |
1800 | ||
fd9c40f6 | 1801 | static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, |
0f95549c | 1802 | struct request *rq, |
396eaf21 | 1803 | blk_qc_t *cookie, |
fd9c40f6 | 1804 | bool bypass_insert, bool last) |
0f95549c MS |
1805 | { |
1806 | struct request_queue *q = rq->q; | |
d964f04a ML |
1807 | bool run_queue = true; |
1808 | ||
23d4ee19 | 1809 | /* |
fd9c40f6 | 1810 | * RCU or SRCU read lock is needed before checking quiesced flag. |
23d4ee19 | 1811 | * |
fd9c40f6 BVA |
1812 | * When queue is stopped or quiesced, ignore 'bypass_insert' from |
1813 | * blk_mq_request_issue_directly(), and return BLK_STS_OK to caller, | |
1814 | * and avoid driver to try to dispatch again. | |
23d4ee19 | 1815 | */ |
fd9c40f6 | 1816 | if (blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(q)) { |
d964f04a | 1817 | run_queue = false; |
fd9c40f6 BVA |
1818 | bypass_insert = false; |
1819 | goto insert; | |
d964f04a | 1820 | } |
f984df1f | 1821 | |
fd9c40f6 BVA |
1822 | if (q->elevator && !bypass_insert) |
1823 | goto insert; | |
2253efc8 | 1824 | |
0bca799b | 1825 | if (!blk_mq_get_dispatch_budget(hctx)) |
fd9c40f6 | 1826 | goto insert; |
bd166ef1 | 1827 | |
8ab6bb9e | 1828 | if (!blk_mq_get_driver_tag(rq)) { |
0bca799b | 1829 | blk_mq_put_dispatch_budget(hctx); |
fd9c40f6 | 1830 | goto insert; |
88022d72 | 1831 | } |
de148297 | 1832 | |
fd9c40f6 BVA |
1833 | return __blk_mq_issue_directly(hctx, rq, cookie, last); |
1834 | insert: | |
1835 | if (bypass_insert) | |
1836 | return BLK_STS_RESOURCE; | |
1837 | ||
1838 | blk_mq_request_bypass_insert(rq, run_queue); | |
1839 | return BLK_STS_OK; | |
1840 | } | |
1841 | ||
1842 | static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, | |
1843 | struct request *rq, blk_qc_t *cookie) | |
1844 | { | |
1845 | blk_status_t ret; | |
1846 | int srcu_idx; | |
1847 | ||
1848 | might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING); | |
1849 | ||
1850 | hctx_lock(hctx, &srcu_idx); | |
1851 | ||
1852 | ret = __blk_mq_try_issue_directly(hctx, rq, cookie, false, true); | |
1853 | if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) | |
1854 | blk_mq_request_bypass_insert(rq, true); | |
1855 | else if (ret != BLK_STS_OK) | |
1856 | blk_mq_end_request(rq, ret); | |
1857 | ||
1858 | hctx_unlock(hctx, srcu_idx); | |
1859 | } | |
1860 | ||
1861 | blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last) | |
1862 | { | |
1863 | blk_status_t ret; | |
1864 | int srcu_idx; | |
1865 | blk_qc_t unused_cookie; | |
1866 | struct blk_mq_hw_ctx *hctx = rq->mq_hctx; | |
1867 | ||
1868 | hctx_lock(hctx, &srcu_idx); | |
1869 | ret = __blk_mq_try_issue_directly(hctx, rq, &unused_cookie, true, last); | |
04ced159 | 1870 | hctx_unlock(hctx, srcu_idx); |
7f556a44 JW |
1871 | |
1872 | return ret; | |
5eb6126e CH |
1873 | } |
1874 | ||
6ce3dd6e ML |
1875 | void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, |
1876 | struct list_head *list) | |
1877 | { | |
1878 | while (!list_empty(list)) { | |
fd9c40f6 | 1879 | blk_status_t ret; |
6ce3dd6e ML |
1880 | struct request *rq = list_first_entry(list, struct request, |
1881 | queuelist); | |
1882 | ||
1883 | list_del_init(&rq->queuelist); | |
fd9c40f6 BVA |
1884 | ret = blk_mq_request_issue_directly(rq, list_empty(list)); |
1885 | if (ret != BLK_STS_OK) { | |
1886 | if (ret == BLK_STS_RESOURCE || | |
1887 | ret == BLK_STS_DEV_RESOURCE) { | |
1888 | blk_mq_request_bypass_insert(rq, | |
c616cbee | 1889 | list_empty(list)); |
fd9c40f6 BVA |
1890 | break; |
1891 | } | |
1892 | blk_mq_end_request(rq, ret); | |
1893 | } | |
6ce3dd6e | 1894 | } |
d666ba98 JA |
1895 | |
1896 | /* | |
1897 | * If we didn't flush the entire list, we could have told | |
1898 | * the driver there was more coming, but that turned out to | |
1899 | * be a lie. | |
1900 | */ | |
fd9c40f6 | 1901 | if (!list_empty(list) && hctx->queue->mq_ops->commit_rqs) |
d666ba98 | 1902 | hctx->queue->mq_ops->commit_rqs(hctx); |
6ce3dd6e ML |
1903 | } |
1904 | ||
ce5b009c JA |
1905 | static void blk_add_rq_to_plug(struct blk_plug *plug, struct request *rq) |
1906 | { | |
1907 | list_add_tail(&rq->queuelist, &plug->mq_list); | |
1908 | plug->rq_count++; | |
1909 | if (!plug->multiple_queues && !list_is_singular(&plug->mq_list)) { | |
1910 | struct request *tmp; | |
1911 | ||
1912 | tmp = list_first_entry(&plug->mq_list, struct request, | |
1913 | queuelist); | |
1914 | if (tmp->q != rq->q) | |
1915 | plug->multiple_queues = true; | |
1916 | } | |
1917 | } | |
1918 | ||
dece1635 | 1919 | static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) |
07068d5b | 1920 | { |
ef295ecf | 1921 | const int is_sync = op_is_sync(bio->bi_opf); |
f73f44eb | 1922 | const int is_flush_fua = op_is_flush(bio->bi_opf); |
7809167d | 1923 | struct blk_mq_alloc_data data = { .flags = 0}; |
07068d5b | 1924 | struct request *rq; |
f984df1f | 1925 | struct blk_plug *plug; |
5b3f341f | 1926 | struct request *same_queue_rq = NULL; |
14ccb66b | 1927 | unsigned int nr_segs; |
7b371636 | 1928 | blk_qc_t cookie; |
07068d5b JA |
1929 | |
1930 | blk_queue_bounce(q, &bio); | |
14ccb66b | 1931 | __blk_queue_split(q, &bio, &nr_segs); |
f36ea50c | 1932 | |
e23947bd | 1933 | if (!bio_integrity_prep(bio)) |
dece1635 | 1934 | return BLK_QC_T_NONE; |
07068d5b | 1935 | |
87c279e6 | 1936 | if (!is_flush_fua && !blk_queue_nomerges(q) && |
14ccb66b | 1937 | blk_attempt_plug_merge(q, bio, nr_segs, &same_queue_rq)) |
87c279e6 | 1938 | return BLK_QC_T_NONE; |
f984df1f | 1939 | |
14ccb66b | 1940 | if (blk_mq_sched_bio_merge(q, bio, nr_segs)) |
bd166ef1 JA |
1941 | return BLK_QC_T_NONE; |
1942 | ||
d5337560 | 1943 | rq_qos_throttle(q, bio); |
87760e5e | 1944 | |
7809167d | 1945 | data.cmd_flags = bio->bi_opf; |
f9afca4d | 1946 | rq = blk_mq_get_request(q, bio, &data); |
87760e5e | 1947 | if (unlikely(!rq)) { |
c1c80384 | 1948 | rq_qos_cleanup(q, bio); |
7b6620d7 | 1949 | if (bio->bi_opf & REQ_NOWAIT) |
03a07c92 | 1950 | bio_wouldblock_error(bio); |
7b6620d7 | 1951 | return BLK_QC_T_NONE; |
87760e5e JA |
1952 | } |
1953 | ||
d6f1dda2 XW |
1954 | trace_block_getrq(q, bio, bio->bi_opf); |
1955 | ||
c1c80384 | 1956 | rq_qos_track(q, rq, bio); |
07068d5b | 1957 | |
fd2d3326 | 1958 | cookie = request_to_qc_t(data.hctx, rq); |
07068d5b | 1959 | |
970d168d BVA |
1960 | blk_mq_bio_to_request(rq, bio, nr_segs); |
1961 | ||
b49773e7 | 1962 | plug = blk_mq_plug(q, bio); |
07068d5b | 1963 | if (unlikely(is_flush_fua)) { |
923218f6 ML |
1964 | /* bypass scheduler for flush rq */ |
1965 | blk_insert_flush(rq); | |
1966 | blk_mq_run_hw_queue(data.hctx, true); | |
3154df26 ML |
1967 | } else if (plug && (q->nr_hw_queues == 1 || q->mq_ops->commit_rqs || |
1968 | !blk_queue_nonrot(q))) { | |
b2c5d16b JA |
1969 | /* |
1970 | * Use plugging if we have a ->commit_rqs() hook as well, as | |
1971 | * we know the driver uses bd->last in a smart fashion. | |
3154df26 ML |
1972 | * |
1973 | * Use normal plugging if this disk is slow HDD, as sequential | |
1974 | * IO may benefit a lot from plug merging. | |
b2c5d16b | 1975 | */ |
5f0ed774 | 1976 | unsigned int request_count = plug->rq_count; |
600271d9 SL |
1977 | struct request *last = NULL; |
1978 | ||
676d0607 | 1979 | if (!request_count) |
e6c4438b | 1980 | trace_block_plug(q); |
600271d9 SL |
1981 | else |
1982 | last = list_entry_rq(plug->mq_list.prev); | |
b094f89c | 1983 | |
600271d9 SL |
1984 | if (request_count >= BLK_MAX_REQUEST_COUNT || (last && |
1985 | blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE)) { | |
e6c4438b JM |
1986 | blk_flush_plug_list(plug, false); |
1987 | trace_block_plug(q); | |
320ae51f | 1988 | } |
b094f89c | 1989 | |
ce5b009c | 1990 | blk_add_rq_to_plug(plug, rq); |
a12de1d4 ML |
1991 | } else if (q->elevator) { |
1992 | blk_mq_sched_insert_request(rq, false, true, true); | |
2299722c | 1993 | } else if (plug && !blk_queue_nomerges(q)) { |
07068d5b | 1994 | /* |
6a83e74d | 1995 | * We do limited plugging. If the bio can be merged, do that. |
f984df1f SL |
1996 | * Otherwise the existing request in the plug list will be |
1997 | * issued. So the plug list will have one request at most | |
2299722c CH |
1998 | * The plug list might get flushed before this. If that happens, |
1999 | * the plug list is empty, and same_queue_rq is invalid. | |
07068d5b | 2000 | */ |
2299722c CH |
2001 | if (list_empty(&plug->mq_list)) |
2002 | same_queue_rq = NULL; | |
4711b573 | 2003 | if (same_queue_rq) { |
2299722c | 2004 | list_del_init(&same_queue_rq->queuelist); |
4711b573 JA |
2005 | plug->rq_count--; |
2006 | } | |
ce5b009c | 2007 | blk_add_rq_to_plug(plug, rq); |
ff3b74b8 | 2008 | trace_block_plug(q); |
2299722c | 2009 | |
dad7a3be | 2010 | if (same_queue_rq) { |
ea4f995e | 2011 | data.hctx = same_queue_rq->mq_hctx; |
ff3b74b8 | 2012 | trace_block_unplug(q, 1, true); |
2299722c | 2013 | blk_mq_try_issue_directly(data.hctx, same_queue_rq, |
fd9c40f6 | 2014 | &cookie); |
dad7a3be | 2015 | } |
a12de1d4 ML |
2016 | } else if ((q->nr_hw_queues > 1 && is_sync) || |
2017 | !data.hctx->dispatch_busy) { | |
fd9c40f6 | 2018 | blk_mq_try_issue_directly(data.hctx, rq, &cookie); |
ab42f35d | 2019 | } else { |
8fa9f556 | 2020 | blk_mq_sched_insert_request(rq, false, true, true); |
ab42f35d | 2021 | } |
320ae51f | 2022 | |
7b371636 | 2023 | return cookie; |
320ae51f JA |
2024 | } |
2025 | ||
cc71a6f4 JA |
2026 | void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, |
2027 | unsigned int hctx_idx) | |
95363efd | 2028 | { |
e9b267d9 | 2029 | struct page *page; |
320ae51f | 2030 | |
24d2f903 | 2031 | if (tags->rqs && set->ops->exit_request) { |
e9b267d9 | 2032 | int i; |
320ae51f | 2033 | |
24d2f903 | 2034 | for (i = 0; i < tags->nr_tags; i++) { |
2af8cbe3 JA |
2035 | struct request *rq = tags->static_rqs[i]; |
2036 | ||
2037 | if (!rq) | |
e9b267d9 | 2038 | continue; |
d6296d39 | 2039 | set->ops->exit_request(set, rq, hctx_idx); |
2af8cbe3 | 2040 | tags->static_rqs[i] = NULL; |
e9b267d9 | 2041 | } |
320ae51f | 2042 | } |
320ae51f | 2043 | |
24d2f903 CH |
2044 | while (!list_empty(&tags->page_list)) { |
2045 | page = list_first_entry(&tags->page_list, struct page, lru); | |
6753471c | 2046 | list_del_init(&page->lru); |
f75782e4 CM |
2047 | /* |
2048 | * Remove kmemleak object previously allocated in | |
273938bf | 2049 | * blk_mq_alloc_rqs(). |
f75782e4 CM |
2050 | */ |
2051 | kmemleak_free(page_address(page)); | |
320ae51f JA |
2052 | __free_pages(page, page->private); |
2053 | } | |
cc71a6f4 | 2054 | } |
320ae51f | 2055 | |
cc71a6f4 JA |
2056 | void blk_mq_free_rq_map(struct blk_mq_tags *tags) |
2057 | { | |
24d2f903 | 2058 | kfree(tags->rqs); |
cc71a6f4 | 2059 | tags->rqs = NULL; |
2af8cbe3 JA |
2060 | kfree(tags->static_rqs); |
2061 | tags->static_rqs = NULL; | |
320ae51f | 2062 | |
24d2f903 | 2063 | blk_mq_free_tags(tags); |
320ae51f JA |
2064 | } |
2065 | ||
cc71a6f4 JA |
2066 | struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, |
2067 | unsigned int hctx_idx, | |
2068 | unsigned int nr_tags, | |
2069 | unsigned int reserved_tags) | |
320ae51f | 2070 | { |
24d2f903 | 2071 | struct blk_mq_tags *tags; |
59f082e4 | 2072 | int node; |
320ae51f | 2073 | |
7d76f856 | 2074 | node = blk_mq_hw_queue_to_node(&set->map[HCTX_TYPE_DEFAULT], hctx_idx); |
59f082e4 SL |
2075 | if (node == NUMA_NO_NODE) |
2076 | node = set->numa_node; | |
2077 | ||
2078 | tags = blk_mq_init_tags(nr_tags, reserved_tags, node, | |
24391c0d | 2079 | BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags)); |
24d2f903 CH |
2080 | if (!tags) |
2081 | return NULL; | |
320ae51f | 2082 | |
590b5b7d | 2083 | tags->rqs = kcalloc_node(nr_tags, sizeof(struct request *), |
36e1f3d1 | 2084 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, |
59f082e4 | 2085 | node); |
24d2f903 CH |
2086 | if (!tags->rqs) { |
2087 | blk_mq_free_tags(tags); | |
2088 | return NULL; | |
2089 | } | |
320ae51f | 2090 | |
590b5b7d KC |
2091 | tags->static_rqs = kcalloc_node(nr_tags, sizeof(struct request *), |
2092 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, | |
2093 | node); | |
2af8cbe3 JA |
2094 | if (!tags->static_rqs) { |
2095 | kfree(tags->rqs); | |
2096 | blk_mq_free_tags(tags); | |
2097 | return NULL; | |
2098 | } | |
2099 | ||
cc71a6f4 JA |
2100 | return tags; |
2101 | } | |
2102 | ||
2103 | static size_t order_to_size(unsigned int order) | |
2104 | { | |
2105 | return (size_t)PAGE_SIZE << order; | |
2106 | } | |
2107 | ||
1d9bd516 TH |
2108 | static int blk_mq_init_request(struct blk_mq_tag_set *set, struct request *rq, |
2109 | unsigned int hctx_idx, int node) | |
2110 | { | |
2111 | int ret; | |
2112 | ||
2113 | if (set->ops->init_request) { | |
2114 | ret = set->ops->init_request(set, rq, hctx_idx, node); | |
2115 | if (ret) | |
2116 | return ret; | |
2117 | } | |
2118 | ||
12f5b931 | 2119 | WRITE_ONCE(rq->state, MQ_RQ_IDLE); |
1d9bd516 TH |
2120 | return 0; |
2121 | } | |
2122 | ||
cc71a6f4 JA |
2123 | int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, |
2124 | unsigned int hctx_idx, unsigned int depth) | |
2125 | { | |
2126 | unsigned int i, j, entries_per_page, max_order = 4; | |
2127 | size_t rq_size, left; | |
59f082e4 SL |
2128 | int node; |
2129 | ||
7d76f856 | 2130 | node = blk_mq_hw_queue_to_node(&set->map[HCTX_TYPE_DEFAULT], hctx_idx); |
59f082e4 SL |
2131 | if (node == NUMA_NO_NODE) |
2132 | node = set->numa_node; | |
cc71a6f4 JA |
2133 | |
2134 | INIT_LIST_HEAD(&tags->page_list); | |
2135 | ||
320ae51f JA |
2136 | /* |
2137 | * rq_size is the size of the request plus driver payload, rounded | |
2138 | * to the cacheline size | |
2139 | */ | |
24d2f903 | 2140 | rq_size = round_up(sizeof(struct request) + set->cmd_size, |
320ae51f | 2141 | cache_line_size()); |
cc71a6f4 | 2142 | left = rq_size * depth; |
320ae51f | 2143 | |
cc71a6f4 | 2144 | for (i = 0; i < depth; ) { |
320ae51f JA |
2145 | int this_order = max_order; |
2146 | struct page *page; | |
2147 | int to_do; | |
2148 | void *p; | |
2149 | ||
b3a834b1 | 2150 | while (this_order && left < order_to_size(this_order - 1)) |
320ae51f JA |
2151 | this_order--; |
2152 | ||
2153 | do { | |
59f082e4 | 2154 | page = alloc_pages_node(node, |
36e1f3d1 | 2155 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO, |
a5164405 | 2156 | this_order); |
320ae51f JA |
2157 | if (page) |
2158 | break; | |
2159 | if (!this_order--) | |
2160 | break; | |
2161 | if (order_to_size(this_order) < rq_size) | |
2162 | break; | |
2163 | } while (1); | |
2164 | ||
2165 | if (!page) | |
24d2f903 | 2166 | goto fail; |
320ae51f JA |
2167 | |
2168 | page->private = this_order; | |
24d2f903 | 2169 | list_add_tail(&page->lru, &tags->page_list); |
320ae51f JA |
2170 | |
2171 | p = page_address(page); | |
f75782e4 CM |
2172 | /* |
2173 | * Allow kmemleak to scan these pages as they contain pointers | |
2174 | * to additional allocations like via ops->init_request(). | |
2175 | */ | |
36e1f3d1 | 2176 | kmemleak_alloc(p, order_to_size(this_order), 1, GFP_NOIO); |
320ae51f | 2177 | entries_per_page = order_to_size(this_order) / rq_size; |
cc71a6f4 | 2178 | to_do = min(entries_per_page, depth - i); |
320ae51f JA |
2179 | left -= to_do * rq_size; |
2180 | for (j = 0; j < to_do; j++) { | |
2af8cbe3 JA |
2181 | struct request *rq = p; |
2182 | ||
2183 | tags->static_rqs[i] = rq; | |
1d9bd516 TH |
2184 | if (blk_mq_init_request(set, rq, hctx_idx, node)) { |
2185 | tags->static_rqs[i] = NULL; | |
2186 | goto fail; | |
e9b267d9 CH |
2187 | } |
2188 | ||
320ae51f JA |
2189 | p += rq_size; |
2190 | i++; | |
2191 | } | |
2192 | } | |
cc71a6f4 | 2193 | return 0; |
320ae51f | 2194 | |
24d2f903 | 2195 | fail: |
cc71a6f4 JA |
2196 | blk_mq_free_rqs(set, tags, hctx_idx); |
2197 | return -ENOMEM; | |
320ae51f JA |
2198 | } |
2199 | ||
e57690fe JA |
2200 | /* |
2201 | * 'cpu' is going away. splice any existing rq_list entries from this | |
2202 | * software queue to the hw queue dispatch list, and ensure that it | |
2203 | * gets run. | |
2204 | */ | |
9467f859 | 2205 | static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node) |
484b4061 | 2206 | { |
9467f859 | 2207 | struct blk_mq_hw_ctx *hctx; |
484b4061 JA |
2208 | struct blk_mq_ctx *ctx; |
2209 | LIST_HEAD(tmp); | |
c16d6b5a | 2210 | enum hctx_type type; |
484b4061 | 2211 | |
9467f859 | 2212 | hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_dead); |
e57690fe | 2213 | ctx = __blk_mq_get_ctx(hctx->queue, cpu); |
c16d6b5a | 2214 | type = hctx->type; |
484b4061 JA |
2215 | |
2216 | spin_lock(&ctx->lock); | |
c16d6b5a ML |
2217 | if (!list_empty(&ctx->rq_lists[type])) { |
2218 | list_splice_init(&ctx->rq_lists[type], &tmp); | |
484b4061 JA |
2219 | blk_mq_hctx_clear_pending(hctx, ctx); |
2220 | } | |
2221 | spin_unlock(&ctx->lock); | |
2222 | ||
2223 | if (list_empty(&tmp)) | |
9467f859 | 2224 | return 0; |
484b4061 | 2225 | |
e57690fe JA |
2226 | spin_lock(&hctx->lock); |
2227 | list_splice_tail_init(&tmp, &hctx->dispatch); | |
2228 | spin_unlock(&hctx->lock); | |
484b4061 JA |
2229 | |
2230 | blk_mq_run_hw_queue(hctx, true); | |
9467f859 | 2231 | return 0; |
484b4061 JA |
2232 | } |
2233 | ||
9467f859 | 2234 | static void blk_mq_remove_cpuhp(struct blk_mq_hw_ctx *hctx) |
484b4061 | 2235 | { |
9467f859 TG |
2236 | cpuhp_state_remove_instance_nocalls(CPUHP_BLK_MQ_DEAD, |
2237 | &hctx->cpuhp_dead); | |
484b4061 JA |
2238 | } |
2239 | ||
c3b4afca | 2240 | /* hctx->ctxs will be freed in queue's release handler */ |
08e98fc6 ML |
2241 | static void blk_mq_exit_hctx(struct request_queue *q, |
2242 | struct blk_mq_tag_set *set, | |
2243 | struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) | |
2244 | { | |
8ab0b7dc ML |
2245 | if (blk_mq_hw_queue_mapped(hctx)) |
2246 | blk_mq_tag_idle(hctx); | |
08e98fc6 | 2247 | |
f70ced09 | 2248 | if (set->ops->exit_request) |
d6296d39 | 2249 | set->ops->exit_request(set, hctx->fq->flush_rq, hctx_idx); |
f70ced09 | 2250 | |
08e98fc6 ML |
2251 | if (set->ops->exit_hctx) |
2252 | set->ops->exit_hctx(hctx, hctx_idx); | |
2253 | ||
9467f859 | 2254 | blk_mq_remove_cpuhp(hctx); |
2f8f1336 ML |
2255 | |
2256 | spin_lock(&q->unused_hctx_lock); | |
2257 | list_add(&hctx->hctx_list, &q->unused_hctx_list); | |
2258 | spin_unlock(&q->unused_hctx_lock); | |
08e98fc6 ML |
2259 | } |
2260 | ||
624dbe47 ML |
2261 | static void blk_mq_exit_hw_queues(struct request_queue *q, |
2262 | struct blk_mq_tag_set *set, int nr_queue) | |
2263 | { | |
2264 | struct blk_mq_hw_ctx *hctx; | |
2265 | unsigned int i; | |
2266 | ||
2267 | queue_for_each_hw_ctx(q, hctx, i) { | |
2268 | if (i == nr_queue) | |
2269 | break; | |
477e19de | 2270 | blk_mq_debugfs_unregister_hctx(hctx); |
08e98fc6 | 2271 | blk_mq_exit_hctx(q, set, hctx, i); |
624dbe47 | 2272 | } |
624dbe47 ML |
2273 | } |
2274 | ||
7c6c5b7c ML |
2275 | static int blk_mq_hw_ctx_size(struct blk_mq_tag_set *tag_set) |
2276 | { | |
2277 | int hw_ctx_size = sizeof(struct blk_mq_hw_ctx); | |
2278 | ||
2279 | BUILD_BUG_ON(ALIGN(offsetof(struct blk_mq_hw_ctx, srcu), | |
2280 | __alignof__(struct blk_mq_hw_ctx)) != | |
2281 | sizeof(struct blk_mq_hw_ctx)); | |
2282 | ||
2283 | if (tag_set->flags & BLK_MQ_F_BLOCKING) | |
2284 | hw_ctx_size += sizeof(struct srcu_struct); | |
2285 | ||
2286 | return hw_ctx_size; | |
2287 | } | |
2288 | ||
08e98fc6 ML |
2289 | static int blk_mq_init_hctx(struct request_queue *q, |
2290 | struct blk_mq_tag_set *set, | |
2291 | struct blk_mq_hw_ctx *hctx, unsigned hctx_idx) | |
320ae51f | 2292 | { |
7c6c5b7c ML |
2293 | hctx->queue_num = hctx_idx; |
2294 | ||
2295 | cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, &hctx->cpuhp_dead); | |
2296 | ||
2297 | hctx->tags = set->tags[hctx_idx]; | |
2298 | ||
2299 | if (set->ops->init_hctx && | |
2300 | set->ops->init_hctx(hctx, set->driver_data, hctx_idx)) | |
2301 | goto unregister_cpu_notifier; | |
08e98fc6 | 2302 | |
7c6c5b7c ML |
2303 | if (blk_mq_init_request(set, hctx->fq->flush_rq, hctx_idx, |
2304 | hctx->numa_node)) | |
2305 | goto exit_hctx; | |
2306 | return 0; | |
2307 | ||
2308 | exit_hctx: | |
2309 | if (set->ops->exit_hctx) | |
2310 | set->ops->exit_hctx(hctx, hctx_idx); | |
2311 | unregister_cpu_notifier: | |
2312 | blk_mq_remove_cpuhp(hctx); | |
2313 | return -1; | |
2314 | } | |
2315 | ||
2316 | static struct blk_mq_hw_ctx * | |
2317 | blk_mq_alloc_hctx(struct request_queue *q, struct blk_mq_tag_set *set, | |
2318 | int node) | |
2319 | { | |
2320 | struct blk_mq_hw_ctx *hctx; | |
2321 | gfp_t gfp = GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY; | |
2322 | ||
2323 | hctx = kzalloc_node(blk_mq_hw_ctx_size(set), gfp, node); | |
2324 | if (!hctx) | |
2325 | goto fail_alloc_hctx; | |
2326 | ||
2327 | if (!zalloc_cpumask_var_node(&hctx->cpumask, gfp, node)) | |
2328 | goto free_hctx; | |
2329 | ||
2330 | atomic_set(&hctx->nr_active, 0); | |
08e98fc6 | 2331 | if (node == NUMA_NO_NODE) |
7c6c5b7c ML |
2332 | node = set->numa_node; |
2333 | hctx->numa_node = node; | |
08e98fc6 | 2334 | |
9f993737 | 2335 | INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn); |
08e98fc6 ML |
2336 | spin_lock_init(&hctx->lock); |
2337 | INIT_LIST_HEAD(&hctx->dispatch); | |
2338 | hctx->queue = q; | |
2404e607 | 2339 | hctx->flags = set->flags & ~BLK_MQ_F_TAG_SHARED; |
08e98fc6 | 2340 | |
2f8f1336 ML |
2341 | INIT_LIST_HEAD(&hctx->hctx_list); |
2342 | ||
320ae51f | 2343 | /* |
08e98fc6 ML |
2344 | * Allocate space for all possible cpus to avoid allocation at |
2345 | * runtime | |
320ae51f | 2346 | */ |
d904bfa7 | 2347 | hctx->ctxs = kmalloc_array_node(nr_cpu_ids, sizeof(void *), |
7c6c5b7c | 2348 | gfp, node); |
08e98fc6 | 2349 | if (!hctx->ctxs) |
7c6c5b7c | 2350 | goto free_cpumask; |
320ae51f | 2351 | |
5b202853 | 2352 | if (sbitmap_init_node(&hctx->ctx_map, nr_cpu_ids, ilog2(8), |
7c6c5b7c | 2353 | gfp, node)) |
08e98fc6 | 2354 | goto free_ctxs; |
08e98fc6 | 2355 | hctx->nr_ctx = 0; |
320ae51f | 2356 | |
5815839b | 2357 | spin_lock_init(&hctx->dispatch_wait_lock); |
eb619fdb JA |
2358 | init_waitqueue_func_entry(&hctx->dispatch_wait, blk_mq_dispatch_wake); |
2359 | INIT_LIST_HEAD(&hctx->dispatch_wait.entry); | |
2360 | ||
5b202853 | 2361 | hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size, |
7c6c5b7c | 2362 | gfp); |
f70ced09 | 2363 | if (!hctx->fq) |
7c6c5b7c | 2364 | goto free_bitmap; |
320ae51f | 2365 | |
6a83e74d | 2366 | if (hctx->flags & BLK_MQ_F_BLOCKING) |
05707b64 | 2367 | init_srcu_struct(hctx->srcu); |
7c6c5b7c | 2368 | blk_mq_hctx_kobj_init(hctx); |
6a83e74d | 2369 | |
7c6c5b7c | 2370 | return hctx; |
320ae51f | 2371 | |
08e98fc6 | 2372 | free_bitmap: |
88459642 | 2373 | sbitmap_free(&hctx->ctx_map); |
08e98fc6 ML |
2374 | free_ctxs: |
2375 | kfree(hctx->ctxs); | |
7c6c5b7c ML |
2376 | free_cpumask: |
2377 | free_cpumask_var(hctx->cpumask); | |
2378 | free_hctx: | |
2379 | kfree(hctx); | |
2380 | fail_alloc_hctx: | |
2381 | return NULL; | |
08e98fc6 | 2382 | } |
320ae51f | 2383 | |
320ae51f JA |
2384 | static void blk_mq_init_cpu_queues(struct request_queue *q, |
2385 | unsigned int nr_hw_queues) | |
2386 | { | |
b3c661b1 JA |
2387 | struct blk_mq_tag_set *set = q->tag_set; |
2388 | unsigned int i, j; | |
320ae51f JA |
2389 | |
2390 | for_each_possible_cpu(i) { | |
2391 | struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i); | |
2392 | struct blk_mq_hw_ctx *hctx; | |
c16d6b5a | 2393 | int k; |
320ae51f | 2394 | |
320ae51f JA |
2395 | __ctx->cpu = i; |
2396 | spin_lock_init(&__ctx->lock); | |
c16d6b5a ML |
2397 | for (k = HCTX_TYPE_DEFAULT; k < HCTX_MAX_TYPES; k++) |
2398 | INIT_LIST_HEAD(&__ctx->rq_lists[k]); | |
2399 | ||
320ae51f JA |
2400 | __ctx->queue = q; |
2401 | ||
320ae51f JA |
2402 | /* |
2403 | * Set local node, IFF we have more than one hw queue. If | |
2404 | * not, we remain on the home node of the device | |
2405 | */ | |
b3c661b1 JA |
2406 | for (j = 0; j < set->nr_maps; j++) { |
2407 | hctx = blk_mq_map_queue_type(q, j, i); | |
2408 | if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE) | |
2409 | hctx->numa_node = local_memory_node(cpu_to_node(i)); | |
2410 | } | |
320ae51f JA |
2411 | } |
2412 | } | |
2413 | ||
cc71a6f4 JA |
2414 | static bool __blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, int hctx_idx) |
2415 | { | |
2416 | int ret = 0; | |
2417 | ||
2418 | set->tags[hctx_idx] = blk_mq_alloc_rq_map(set, hctx_idx, | |
2419 | set->queue_depth, set->reserved_tags); | |
2420 | if (!set->tags[hctx_idx]) | |
2421 | return false; | |
2422 | ||
2423 | ret = blk_mq_alloc_rqs(set, set->tags[hctx_idx], hctx_idx, | |
2424 | set->queue_depth); | |
2425 | if (!ret) | |
2426 | return true; | |
2427 | ||
2428 | blk_mq_free_rq_map(set->tags[hctx_idx]); | |
2429 | set->tags[hctx_idx] = NULL; | |
2430 | return false; | |
2431 | } | |
2432 | ||
2433 | static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set, | |
2434 | unsigned int hctx_idx) | |
2435 | { | |
4e6db0f2 | 2436 | if (set->tags && set->tags[hctx_idx]) { |
bd166ef1 JA |
2437 | blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx); |
2438 | blk_mq_free_rq_map(set->tags[hctx_idx]); | |
2439 | set->tags[hctx_idx] = NULL; | |
2440 | } | |
cc71a6f4 JA |
2441 | } |
2442 | ||
4b855ad3 | 2443 | static void blk_mq_map_swqueue(struct request_queue *q) |
320ae51f | 2444 | { |
b3c661b1 | 2445 | unsigned int i, j, hctx_idx; |
320ae51f JA |
2446 | struct blk_mq_hw_ctx *hctx; |
2447 | struct blk_mq_ctx *ctx; | |
2a34c087 | 2448 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f JA |
2449 | |
2450 | queue_for_each_hw_ctx(q, hctx, i) { | |
e4043dcf | 2451 | cpumask_clear(hctx->cpumask); |
320ae51f | 2452 | hctx->nr_ctx = 0; |
d416c92c | 2453 | hctx->dispatch_from = NULL; |
320ae51f JA |
2454 | } |
2455 | ||
2456 | /* | |
4b855ad3 | 2457 | * Map software to hardware queues. |
4412efec ML |
2458 | * |
2459 | * If the cpu isn't present, the cpu is mapped to first hctx. | |
320ae51f | 2460 | */ |
20e4d813 | 2461 | for_each_possible_cpu(i) { |
7d76f856 | 2462 | hctx_idx = set->map[HCTX_TYPE_DEFAULT].mq_map[i]; |
4412efec ML |
2463 | /* unmapped hw queue can be remapped after CPU topo changed */ |
2464 | if (!set->tags[hctx_idx] && | |
2465 | !__blk_mq_alloc_rq_map(set, hctx_idx)) { | |
2466 | /* | |
2467 | * If tags initialization fail for some hctx, | |
2468 | * that hctx won't be brought online. In this | |
2469 | * case, remap the current ctx to hctx[0] which | |
2470 | * is guaranteed to always have tags allocated | |
2471 | */ | |
7d76f856 | 2472 | set->map[HCTX_TYPE_DEFAULT].mq_map[i] = 0; |
4412efec ML |
2473 | } |
2474 | ||
897bb0c7 | 2475 | ctx = per_cpu_ptr(q->queue_ctx, i); |
b3c661b1 | 2476 | for (j = 0; j < set->nr_maps; j++) { |
bb94aea1 JW |
2477 | if (!set->map[j].nr_queues) { |
2478 | ctx->hctxs[j] = blk_mq_map_queue_type(q, | |
2479 | HCTX_TYPE_DEFAULT, i); | |
e5edd5f2 | 2480 | continue; |
bb94aea1 | 2481 | } |
e5edd5f2 | 2482 | |
b3c661b1 | 2483 | hctx = blk_mq_map_queue_type(q, j, i); |
8ccdf4a3 | 2484 | ctx->hctxs[j] = hctx; |
b3c661b1 JA |
2485 | /* |
2486 | * If the CPU is already set in the mask, then we've | |
2487 | * mapped this one already. This can happen if | |
2488 | * devices share queues across queue maps. | |
2489 | */ | |
2490 | if (cpumask_test_cpu(i, hctx->cpumask)) | |
2491 | continue; | |
2492 | ||
2493 | cpumask_set_cpu(i, hctx->cpumask); | |
2494 | hctx->type = j; | |
2495 | ctx->index_hw[hctx->type] = hctx->nr_ctx; | |
2496 | hctx->ctxs[hctx->nr_ctx++] = ctx; | |
2497 | ||
2498 | /* | |
2499 | * If the nr_ctx type overflows, we have exceeded the | |
2500 | * amount of sw queues we can support. | |
2501 | */ | |
2502 | BUG_ON(!hctx->nr_ctx); | |
2503 | } | |
bb94aea1 JW |
2504 | |
2505 | for (; j < HCTX_MAX_TYPES; j++) | |
2506 | ctx->hctxs[j] = blk_mq_map_queue_type(q, | |
2507 | HCTX_TYPE_DEFAULT, i); | |
320ae51f | 2508 | } |
506e931f JA |
2509 | |
2510 | queue_for_each_hw_ctx(q, hctx, i) { | |
4412efec ML |
2511 | /* |
2512 | * If no software queues are mapped to this hardware queue, | |
2513 | * disable it and free the request entries. | |
2514 | */ | |
2515 | if (!hctx->nr_ctx) { | |
2516 | /* Never unmap queue 0. We need it as a | |
2517 | * fallback in case of a new remap fails | |
2518 | * allocation | |
2519 | */ | |
2520 | if (i && set->tags[i]) | |
2521 | blk_mq_free_map_and_requests(set, i); | |
2522 | ||
2523 | hctx->tags = NULL; | |
2524 | continue; | |
2525 | } | |
484b4061 | 2526 | |
2a34c087 ML |
2527 | hctx->tags = set->tags[i]; |
2528 | WARN_ON(!hctx->tags); | |
2529 | ||
889fa31f CY |
2530 | /* |
2531 | * Set the map size to the number of mapped software queues. | |
2532 | * This is more accurate and more efficient than looping | |
2533 | * over all possibly mapped software queues. | |
2534 | */ | |
88459642 | 2535 | sbitmap_resize(&hctx->ctx_map, hctx->nr_ctx); |
889fa31f | 2536 | |
484b4061 JA |
2537 | /* |
2538 | * Initialize batch roundrobin counts | |
2539 | */ | |
f82ddf19 | 2540 | hctx->next_cpu = blk_mq_first_mapped_cpu(hctx); |
506e931f JA |
2541 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; |
2542 | } | |
320ae51f JA |
2543 | } |
2544 | ||
8e8320c9 JA |
2545 | /* |
2546 | * Caller needs to ensure that we're either frozen/quiesced, or that | |
2547 | * the queue isn't live yet. | |
2548 | */ | |
2404e607 | 2549 | static void queue_set_hctx_shared(struct request_queue *q, bool shared) |
0d2602ca JA |
2550 | { |
2551 | struct blk_mq_hw_ctx *hctx; | |
0d2602ca JA |
2552 | int i; |
2553 | ||
2404e607 | 2554 | queue_for_each_hw_ctx(q, hctx, i) { |
97889f9a | 2555 | if (shared) |
2404e607 | 2556 | hctx->flags |= BLK_MQ_F_TAG_SHARED; |
97889f9a | 2557 | else |
2404e607 JM |
2558 | hctx->flags &= ~BLK_MQ_F_TAG_SHARED; |
2559 | } | |
2560 | } | |
2561 | ||
8e8320c9 JA |
2562 | static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set, |
2563 | bool shared) | |
2404e607 JM |
2564 | { |
2565 | struct request_queue *q; | |
0d2602ca | 2566 | |
705cda97 BVA |
2567 | lockdep_assert_held(&set->tag_list_lock); |
2568 | ||
0d2602ca JA |
2569 | list_for_each_entry(q, &set->tag_list, tag_set_list) { |
2570 | blk_mq_freeze_queue(q); | |
2404e607 | 2571 | queue_set_hctx_shared(q, shared); |
0d2602ca JA |
2572 | blk_mq_unfreeze_queue(q); |
2573 | } | |
2574 | } | |
2575 | ||
2576 | static void blk_mq_del_queue_tag_set(struct request_queue *q) | |
2577 | { | |
2578 | struct blk_mq_tag_set *set = q->tag_set; | |
2579 | ||
0d2602ca | 2580 | mutex_lock(&set->tag_list_lock); |
705cda97 | 2581 | list_del_rcu(&q->tag_set_list); |
2404e607 JM |
2582 | if (list_is_singular(&set->tag_list)) { |
2583 | /* just transitioned to unshared */ | |
2584 | set->flags &= ~BLK_MQ_F_TAG_SHARED; | |
2585 | /* update existing queue */ | |
2586 | blk_mq_update_tag_set_depth(set, false); | |
2587 | } | |
0d2602ca | 2588 | mutex_unlock(&set->tag_list_lock); |
a347c7ad | 2589 | INIT_LIST_HEAD(&q->tag_set_list); |
0d2602ca JA |
2590 | } |
2591 | ||
2592 | static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, | |
2593 | struct request_queue *q) | |
2594 | { | |
0d2602ca | 2595 | mutex_lock(&set->tag_list_lock); |
2404e607 | 2596 | |
ff821d27 JA |
2597 | /* |
2598 | * Check to see if we're transitioning to shared (from 1 to 2 queues). | |
2599 | */ | |
2600 | if (!list_empty(&set->tag_list) && | |
2601 | !(set->flags & BLK_MQ_F_TAG_SHARED)) { | |
2404e607 JM |
2602 | set->flags |= BLK_MQ_F_TAG_SHARED; |
2603 | /* update existing queue */ | |
2604 | blk_mq_update_tag_set_depth(set, true); | |
2605 | } | |
2606 | if (set->flags & BLK_MQ_F_TAG_SHARED) | |
2607 | queue_set_hctx_shared(q, true); | |
705cda97 | 2608 | list_add_tail_rcu(&q->tag_set_list, &set->tag_list); |
2404e607 | 2609 | |
0d2602ca JA |
2610 | mutex_unlock(&set->tag_list_lock); |
2611 | } | |
2612 | ||
1db4909e ML |
2613 | /* All allocations will be freed in release handler of q->mq_kobj */ |
2614 | static int blk_mq_alloc_ctxs(struct request_queue *q) | |
2615 | { | |
2616 | struct blk_mq_ctxs *ctxs; | |
2617 | int cpu; | |
2618 | ||
2619 | ctxs = kzalloc(sizeof(*ctxs), GFP_KERNEL); | |
2620 | if (!ctxs) | |
2621 | return -ENOMEM; | |
2622 | ||
2623 | ctxs->queue_ctx = alloc_percpu(struct blk_mq_ctx); | |
2624 | if (!ctxs->queue_ctx) | |
2625 | goto fail; | |
2626 | ||
2627 | for_each_possible_cpu(cpu) { | |
2628 | struct blk_mq_ctx *ctx = per_cpu_ptr(ctxs->queue_ctx, cpu); | |
2629 | ctx->ctxs = ctxs; | |
2630 | } | |
2631 | ||
2632 | q->mq_kobj = &ctxs->kobj; | |
2633 | q->queue_ctx = ctxs->queue_ctx; | |
2634 | ||
2635 | return 0; | |
2636 | fail: | |
2637 | kfree(ctxs); | |
2638 | return -ENOMEM; | |
2639 | } | |
2640 | ||
e09aae7e ML |
2641 | /* |
2642 | * It is the actual release handler for mq, but we do it from | |
2643 | * request queue's release handler for avoiding use-after-free | |
2644 | * and headache because q->mq_kobj shouldn't have been introduced, | |
2645 | * but we can't group ctx/kctx kobj without it. | |
2646 | */ | |
2647 | void blk_mq_release(struct request_queue *q) | |
2648 | { | |
2f8f1336 ML |
2649 | struct blk_mq_hw_ctx *hctx, *next; |
2650 | int i; | |
e09aae7e | 2651 | |
2f8f1336 ML |
2652 | queue_for_each_hw_ctx(q, hctx, i) |
2653 | WARN_ON_ONCE(hctx && list_empty(&hctx->hctx_list)); | |
2654 | ||
2655 | /* all hctx are in .unused_hctx_list now */ | |
2656 | list_for_each_entry_safe(hctx, next, &q->unused_hctx_list, hctx_list) { | |
2657 | list_del_init(&hctx->hctx_list); | |
6c8b232e | 2658 | kobject_put(&hctx->kobj); |
c3b4afca | 2659 | } |
e09aae7e ML |
2660 | |
2661 | kfree(q->queue_hw_ctx); | |
2662 | ||
7ea5fe31 ML |
2663 | /* |
2664 | * release .mq_kobj and sw queue's kobject now because | |
2665 | * both share lifetime with request queue. | |
2666 | */ | |
2667 | blk_mq_sysfs_deinit(q); | |
e09aae7e ML |
2668 | } |
2669 | ||
24d2f903 | 2670 | struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) |
b62c21b7 MS |
2671 | { |
2672 | struct request_queue *uninit_q, *q; | |
2673 | ||
6d469642 | 2674 | uninit_q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node); |
b62c21b7 MS |
2675 | if (!uninit_q) |
2676 | return ERR_PTR(-ENOMEM); | |
2677 | ||
737eb78e DLM |
2678 | /* |
2679 | * Initialize the queue without an elevator. device_add_disk() will do | |
2680 | * the initialization. | |
2681 | */ | |
2682 | q = blk_mq_init_allocated_queue(set, uninit_q, false); | |
b62c21b7 MS |
2683 | if (IS_ERR(q)) |
2684 | blk_cleanup_queue(uninit_q); | |
2685 | ||
2686 | return q; | |
2687 | } | |
2688 | EXPORT_SYMBOL(blk_mq_init_queue); | |
2689 | ||
9316a9ed JA |
2690 | /* |
2691 | * Helper for setting up a queue with mq ops, given queue depth, and | |
2692 | * the passed in mq ops flags. | |
2693 | */ | |
2694 | struct request_queue *blk_mq_init_sq_queue(struct blk_mq_tag_set *set, | |
2695 | const struct blk_mq_ops *ops, | |
2696 | unsigned int queue_depth, | |
2697 | unsigned int set_flags) | |
2698 | { | |
2699 | struct request_queue *q; | |
2700 | int ret; | |
2701 | ||
2702 | memset(set, 0, sizeof(*set)); | |
2703 | set->ops = ops; | |
2704 | set->nr_hw_queues = 1; | |
b3c661b1 | 2705 | set->nr_maps = 1; |
9316a9ed JA |
2706 | set->queue_depth = queue_depth; |
2707 | set->numa_node = NUMA_NO_NODE; | |
2708 | set->flags = set_flags; | |
2709 | ||
2710 | ret = blk_mq_alloc_tag_set(set); | |
2711 | if (ret) | |
2712 | return ERR_PTR(ret); | |
2713 | ||
2714 | q = blk_mq_init_queue(set); | |
2715 | if (IS_ERR(q)) { | |
2716 | blk_mq_free_tag_set(set); | |
2717 | return q; | |
2718 | } | |
2719 | ||
2720 | return q; | |
2721 | } | |
2722 | EXPORT_SYMBOL(blk_mq_init_sq_queue); | |
2723 | ||
34d11ffa JW |
2724 | static struct blk_mq_hw_ctx *blk_mq_alloc_and_init_hctx( |
2725 | struct blk_mq_tag_set *set, struct request_queue *q, | |
2726 | int hctx_idx, int node) | |
2727 | { | |
2f8f1336 | 2728 | struct blk_mq_hw_ctx *hctx = NULL, *tmp; |
34d11ffa | 2729 | |
2f8f1336 ML |
2730 | /* reuse dead hctx first */ |
2731 | spin_lock(&q->unused_hctx_lock); | |
2732 | list_for_each_entry(tmp, &q->unused_hctx_list, hctx_list) { | |
2733 | if (tmp->numa_node == node) { | |
2734 | hctx = tmp; | |
2735 | break; | |
2736 | } | |
2737 | } | |
2738 | if (hctx) | |
2739 | list_del_init(&hctx->hctx_list); | |
2740 | spin_unlock(&q->unused_hctx_lock); | |
2741 | ||
2742 | if (!hctx) | |
2743 | hctx = blk_mq_alloc_hctx(q, set, node); | |
34d11ffa | 2744 | if (!hctx) |
7c6c5b7c | 2745 | goto fail; |
34d11ffa | 2746 | |
7c6c5b7c ML |
2747 | if (blk_mq_init_hctx(q, set, hctx, hctx_idx)) |
2748 | goto free_hctx; | |
34d11ffa JW |
2749 | |
2750 | return hctx; | |
7c6c5b7c ML |
2751 | |
2752 | free_hctx: | |
2753 | kobject_put(&hctx->kobj); | |
2754 | fail: | |
2755 | return NULL; | |
34d11ffa JW |
2756 | } |
2757 | ||
868f2f0b KB |
2758 | static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, |
2759 | struct request_queue *q) | |
320ae51f | 2760 | { |
e01ad46d | 2761 | int i, j, end; |
868f2f0b | 2762 | struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx; |
f14bbe77 | 2763 | |
ac0d6b92 BVA |
2764 | if (q->nr_hw_queues < set->nr_hw_queues) { |
2765 | struct blk_mq_hw_ctx **new_hctxs; | |
2766 | ||
2767 | new_hctxs = kcalloc_node(set->nr_hw_queues, | |
2768 | sizeof(*new_hctxs), GFP_KERNEL, | |
2769 | set->numa_node); | |
2770 | if (!new_hctxs) | |
2771 | return; | |
2772 | if (hctxs) | |
2773 | memcpy(new_hctxs, hctxs, q->nr_hw_queues * | |
2774 | sizeof(*hctxs)); | |
2775 | q->queue_hw_ctx = new_hctxs; | |
2776 | q->nr_hw_queues = set->nr_hw_queues; | |
2777 | kfree(hctxs); | |
2778 | hctxs = new_hctxs; | |
2779 | } | |
2780 | ||
fb350e0a ML |
2781 | /* protect against switching io scheduler */ |
2782 | mutex_lock(&q->sysfs_lock); | |
24d2f903 | 2783 | for (i = 0; i < set->nr_hw_queues; i++) { |
868f2f0b | 2784 | int node; |
34d11ffa | 2785 | struct blk_mq_hw_ctx *hctx; |
868f2f0b | 2786 | |
7d76f856 | 2787 | node = blk_mq_hw_queue_to_node(&set->map[HCTX_TYPE_DEFAULT], i); |
34d11ffa JW |
2788 | /* |
2789 | * If the hw queue has been mapped to another numa node, | |
2790 | * we need to realloc the hctx. If allocation fails, fallback | |
2791 | * to use the previous one. | |
2792 | */ | |
2793 | if (hctxs[i] && (hctxs[i]->numa_node == node)) | |
2794 | continue; | |
868f2f0b | 2795 | |
34d11ffa JW |
2796 | hctx = blk_mq_alloc_and_init_hctx(set, q, i, node); |
2797 | if (hctx) { | |
2f8f1336 | 2798 | if (hctxs[i]) |
34d11ffa | 2799 | blk_mq_exit_hctx(q, set, hctxs[i], i); |
34d11ffa JW |
2800 | hctxs[i] = hctx; |
2801 | } else { | |
2802 | if (hctxs[i]) | |
2803 | pr_warn("Allocate new hctx on node %d fails,\ | |
2804 | fallback to previous one on node %d\n", | |
2805 | node, hctxs[i]->numa_node); | |
2806 | else | |
2807 | break; | |
868f2f0b | 2808 | } |
320ae51f | 2809 | } |
e01ad46d JW |
2810 | /* |
2811 | * Increasing nr_hw_queues fails. Free the newly allocated | |
2812 | * hctxs and keep the previous q->nr_hw_queues. | |
2813 | */ | |
2814 | if (i != set->nr_hw_queues) { | |
2815 | j = q->nr_hw_queues; | |
2816 | end = i; | |
2817 | } else { | |
2818 | j = i; | |
2819 | end = q->nr_hw_queues; | |
2820 | q->nr_hw_queues = set->nr_hw_queues; | |
2821 | } | |
34d11ffa | 2822 | |
e01ad46d | 2823 | for (; j < end; j++) { |
868f2f0b KB |
2824 | struct blk_mq_hw_ctx *hctx = hctxs[j]; |
2825 | ||
2826 | if (hctx) { | |
cc71a6f4 JA |
2827 | if (hctx->tags) |
2828 | blk_mq_free_map_and_requests(set, j); | |
868f2f0b | 2829 | blk_mq_exit_hctx(q, set, hctx, j); |
868f2f0b | 2830 | hctxs[j] = NULL; |
868f2f0b KB |
2831 | } |
2832 | } | |
fb350e0a | 2833 | mutex_unlock(&q->sysfs_lock); |
868f2f0b KB |
2834 | } |
2835 | ||
2836 | struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, | |
737eb78e DLM |
2837 | struct request_queue *q, |
2838 | bool elevator_init) | |
868f2f0b | 2839 | { |
66841672 ML |
2840 | /* mark the queue as mq asap */ |
2841 | q->mq_ops = set->ops; | |
2842 | ||
34dbad5d | 2843 | q->poll_cb = blk_stat_alloc_callback(blk_mq_poll_stats_fn, |
720b8ccc SB |
2844 | blk_mq_poll_stats_bkt, |
2845 | BLK_MQ_POLL_STATS_BKTS, q); | |
34dbad5d OS |
2846 | if (!q->poll_cb) |
2847 | goto err_exit; | |
2848 | ||
1db4909e | 2849 | if (blk_mq_alloc_ctxs(q)) |
41de54c6 | 2850 | goto err_poll; |
868f2f0b | 2851 | |
737f98cf ML |
2852 | /* init q->mq_kobj and sw queues' kobjects */ |
2853 | blk_mq_sysfs_init(q); | |
2854 | ||
2f8f1336 ML |
2855 | INIT_LIST_HEAD(&q->unused_hctx_list); |
2856 | spin_lock_init(&q->unused_hctx_lock); | |
2857 | ||
868f2f0b KB |
2858 | blk_mq_realloc_hw_ctxs(set, q); |
2859 | if (!q->nr_hw_queues) | |
2860 | goto err_hctxs; | |
320ae51f | 2861 | |
287922eb | 2862 | INIT_WORK(&q->timeout_work, blk_mq_timeout_work); |
e56f698b | 2863 | blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ); |
320ae51f | 2864 | |
a8908939 | 2865 | q->tag_set = set; |
320ae51f | 2866 | |
94eddfbe | 2867 | q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; |
cd19181b ML |
2868 | if (set->nr_maps > HCTX_TYPE_POLL && |
2869 | set->map[HCTX_TYPE_POLL].nr_queues) | |
6544d229 | 2870 | blk_queue_flag_set(QUEUE_FLAG_POLL, q); |
320ae51f | 2871 | |
1be036e9 CH |
2872 | q->sg_reserved_size = INT_MAX; |
2873 | ||
2849450a | 2874 | INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work); |
6fca6a61 CH |
2875 | INIT_LIST_HEAD(&q->requeue_list); |
2876 | spin_lock_init(&q->requeue_lock); | |
2877 | ||
254d259d | 2878 | blk_queue_make_request(q, blk_mq_make_request); |
07068d5b | 2879 | |
eba71768 JA |
2880 | /* |
2881 | * Do this after blk_queue_make_request() overrides it... | |
2882 | */ | |
2883 | q->nr_requests = set->queue_depth; | |
2884 | ||
64f1c21e JA |
2885 | /* |
2886 | * Default to classic polling | |
2887 | */ | |
29ece8b4 | 2888 | q->poll_nsec = BLK_MQ_POLL_CLASSIC; |
64f1c21e | 2889 | |
24d2f903 | 2890 | blk_mq_init_cpu_queues(q, set->nr_hw_queues); |
0d2602ca | 2891 | blk_mq_add_queue_tag_set(set, q); |
4b855ad3 | 2892 | blk_mq_map_swqueue(q); |
4593fdbe | 2893 | |
737eb78e DLM |
2894 | if (elevator_init) |
2895 | elevator_init_mq(q); | |
d3484991 | 2896 | |
320ae51f | 2897 | return q; |
18741986 | 2898 | |
320ae51f | 2899 | err_hctxs: |
868f2f0b | 2900 | kfree(q->queue_hw_ctx); |
73d9c8d4 | 2901 | q->nr_hw_queues = 0; |
1db4909e | 2902 | blk_mq_sysfs_deinit(q); |
41de54c6 JS |
2903 | err_poll: |
2904 | blk_stat_free_callback(q->poll_cb); | |
2905 | q->poll_cb = NULL; | |
c7de5726 ML |
2906 | err_exit: |
2907 | q->mq_ops = NULL; | |
320ae51f JA |
2908 | return ERR_PTR(-ENOMEM); |
2909 | } | |
b62c21b7 | 2910 | EXPORT_SYMBOL(blk_mq_init_allocated_queue); |
320ae51f | 2911 | |
c7e2d94b ML |
2912 | /* tags can _not_ be used after returning from blk_mq_exit_queue */ |
2913 | void blk_mq_exit_queue(struct request_queue *q) | |
320ae51f | 2914 | { |
624dbe47 | 2915 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 2916 | |
0d2602ca | 2917 | blk_mq_del_queue_tag_set(q); |
624dbe47 | 2918 | blk_mq_exit_hw_queues(q, set, set->nr_hw_queues); |
320ae51f | 2919 | } |
320ae51f | 2920 | |
a5164405 JA |
2921 | static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) |
2922 | { | |
2923 | int i; | |
2924 | ||
cc71a6f4 JA |
2925 | for (i = 0; i < set->nr_hw_queues; i++) |
2926 | if (!__blk_mq_alloc_rq_map(set, i)) | |
a5164405 | 2927 | goto out_unwind; |
a5164405 JA |
2928 | |
2929 | return 0; | |
2930 | ||
2931 | out_unwind: | |
2932 | while (--i >= 0) | |
cc71a6f4 | 2933 | blk_mq_free_rq_map(set->tags[i]); |
a5164405 | 2934 | |
a5164405 JA |
2935 | return -ENOMEM; |
2936 | } | |
2937 | ||
2938 | /* | |
2939 | * Allocate the request maps associated with this tag_set. Note that this | |
2940 | * may reduce the depth asked for, if memory is tight. set->queue_depth | |
2941 | * will be updated to reflect the allocated depth. | |
2942 | */ | |
2943 | static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) | |
2944 | { | |
2945 | unsigned int depth; | |
2946 | int err; | |
2947 | ||
2948 | depth = set->queue_depth; | |
2949 | do { | |
2950 | err = __blk_mq_alloc_rq_maps(set); | |
2951 | if (!err) | |
2952 | break; | |
2953 | ||
2954 | set->queue_depth >>= 1; | |
2955 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) { | |
2956 | err = -ENOMEM; | |
2957 | break; | |
2958 | } | |
2959 | } while (set->queue_depth); | |
2960 | ||
2961 | if (!set->queue_depth || err) { | |
2962 | pr_err("blk-mq: failed to allocate request map\n"); | |
2963 | return -ENOMEM; | |
2964 | } | |
2965 | ||
2966 | if (depth != set->queue_depth) | |
2967 | pr_info("blk-mq: reduced tag depth (%u -> %u)\n", | |
2968 | depth, set->queue_depth); | |
2969 | ||
2970 | return 0; | |
2971 | } | |
2972 | ||
ebe8bddb OS |
2973 | static int blk_mq_update_queue_map(struct blk_mq_tag_set *set) |
2974 | { | |
59388702 | 2975 | if (set->ops->map_queues && !is_kdump_kernel()) { |
b3c661b1 JA |
2976 | int i; |
2977 | ||
7d4901a9 ML |
2978 | /* |
2979 | * transport .map_queues is usually done in the following | |
2980 | * way: | |
2981 | * | |
2982 | * for (queue = 0; queue < set->nr_hw_queues; queue++) { | |
2983 | * mask = get_cpu_mask(queue) | |
2984 | * for_each_cpu(cpu, mask) | |
b3c661b1 | 2985 | * set->map[x].mq_map[cpu] = queue; |
7d4901a9 ML |
2986 | * } |
2987 | * | |
2988 | * When we need to remap, the table has to be cleared for | |
2989 | * killing stale mapping since one CPU may not be mapped | |
2990 | * to any hw queue. | |
2991 | */ | |
b3c661b1 JA |
2992 | for (i = 0; i < set->nr_maps; i++) |
2993 | blk_mq_clear_mq_map(&set->map[i]); | |
7d4901a9 | 2994 | |
ebe8bddb | 2995 | return set->ops->map_queues(set); |
b3c661b1 JA |
2996 | } else { |
2997 | BUG_ON(set->nr_maps > 1); | |
7d76f856 | 2998 | return blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]); |
b3c661b1 | 2999 | } |
ebe8bddb OS |
3000 | } |
3001 | ||
f7e76dbc BVA |
3002 | static int blk_mq_realloc_tag_set_tags(struct blk_mq_tag_set *set, |
3003 | int cur_nr_hw_queues, int new_nr_hw_queues) | |
3004 | { | |
3005 | struct blk_mq_tags **new_tags; | |
3006 | ||
3007 | if (cur_nr_hw_queues >= new_nr_hw_queues) | |
3008 | return 0; | |
3009 | ||
3010 | new_tags = kcalloc_node(new_nr_hw_queues, sizeof(struct blk_mq_tags *), | |
3011 | GFP_KERNEL, set->numa_node); | |
3012 | if (!new_tags) | |
3013 | return -ENOMEM; | |
3014 | ||
3015 | if (set->tags) | |
3016 | memcpy(new_tags, set->tags, cur_nr_hw_queues * | |
3017 | sizeof(*set->tags)); | |
3018 | kfree(set->tags); | |
3019 | set->tags = new_tags; | |
3020 | set->nr_hw_queues = new_nr_hw_queues; | |
3021 | ||
3022 | return 0; | |
3023 | } | |
3024 | ||
a4391c64 JA |
3025 | /* |
3026 | * Alloc a tag set to be associated with one or more request queues. | |
3027 | * May fail with EINVAL for various error conditions. May adjust the | |
c018c84f | 3028 | * requested depth down, if it's too large. In that case, the set |
a4391c64 JA |
3029 | * value will be stored in set->queue_depth. |
3030 | */ | |
24d2f903 CH |
3031 | int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) |
3032 | { | |
b3c661b1 | 3033 | int i, ret; |
da695ba2 | 3034 | |
205fb5f5 BVA |
3035 | BUILD_BUG_ON(BLK_MQ_MAX_DEPTH > 1 << BLK_MQ_UNIQUE_TAG_BITS); |
3036 | ||
24d2f903 CH |
3037 | if (!set->nr_hw_queues) |
3038 | return -EINVAL; | |
a4391c64 | 3039 | if (!set->queue_depth) |
24d2f903 CH |
3040 | return -EINVAL; |
3041 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) | |
3042 | return -EINVAL; | |
3043 | ||
7d7e0f90 | 3044 | if (!set->ops->queue_rq) |
24d2f903 CH |
3045 | return -EINVAL; |
3046 | ||
de148297 ML |
3047 | if (!set->ops->get_budget ^ !set->ops->put_budget) |
3048 | return -EINVAL; | |
3049 | ||
a4391c64 JA |
3050 | if (set->queue_depth > BLK_MQ_MAX_DEPTH) { |
3051 | pr_info("blk-mq: reduced tag depth to %u\n", | |
3052 | BLK_MQ_MAX_DEPTH); | |
3053 | set->queue_depth = BLK_MQ_MAX_DEPTH; | |
3054 | } | |
24d2f903 | 3055 | |
b3c661b1 JA |
3056 | if (!set->nr_maps) |
3057 | set->nr_maps = 1; | |
3058 | else if (set->nr_maps > HCTX_MAX_TYPES) | |
3059 | return -EINVAL; | |
3060 | ||
6637fadf SL |
3061 | /* |
3062 | * If a crashdump is active, then we are potentially in a very | |
3063 | * memory constrained environment. Limit us to 1 queue and | |
3064 | * 64 tags to prevent using too much memory. | |
3065 | */ | |
3066 | if (is_kdump_kernel()) { | |
3067 | set->nr_hw_queues = 1; | |
59388702 | 3068 | set->nr_maps = 1; |
6637fadf SL |
3069 | set->queue_depth = min(64U, set->queue_depth); |
3070 | } | |
868f2f0b | 3071 | /* |
392546ae JA |
3072 | * There is no use for more h/w queues than cpus if we just have |
3073 | * a single map | |
868f2f0b | 3074 | */ |
392546ae | 3075 | if (set->nr_maps == 1 && set->nr_hw_queues > nr_cpu_ids) |
868f2f0b | 3076 | set->nr_hw_queues = nr_cpu_ids; |
6637fadf | 3077 | |
f7e76dbc | 3078 | if (blk_mq_realloc_tag_set_tags(set, 0, set->nr_hw_queues) < 0) |
a5164405 | 3079 | return -ENOMEM; |
24d2f903 | 3080 | |
da695ba2 | 3081 | ret = -ENOMEM; |
b3c661b1 JA |
3082 | for (i = 0; i < set->nr_maps; i++) { |
3083 | set->map[i].mq_map = kcalloc_node(nr_cpu_ids, | |
07b35eb5 | 3084 | sizeof(set->map[i].mq_map[0]), |
b3c661b1 JA |
3085 | GFP_KERNEL, set->numa_node); |
3086 | if (!set->map[i].mq_map) | |
3087 | goto out_free_mq_map; | |
59388702 | 3088 | set->map[i].nr_queues = is_kdump_kernel() ? 1 : set->nr_hw_queues; |
b3c661b1 | 3089 | } |
bdd17e75 | 3090 | |
ebe8bddb | 3091 | ret = blk_mq_update_queue_map(set); |
da695ba2 CH |
3092 | if (ret) |
3093 | goto out_free_mq_map; | |
3094 | ||
3095 | ret = blk_mq_alloc_rq_maps(set); | |
3096 | if (ret) | |
bdd17e75 | 3097 | goto out_free_mq_map; |
24d2f903 | 3098 | |
0d2602ca JA |
3099 | mutex_init(&set->tag_list_lock); |
3100 | INIT_LIST_HEAD(&set->tag_list); | |
3101 | ||
24d2f903 | 3102 | return 0; |
bdd17e75 CH |
3103 | |
3104 | out_free_mq_map: | |
b3c661b1 JA |
3105 | for (i = 0; i < set->nr_maps; i++) { |
3106 | kfree(set->map[i].mq_map); | |
3107 | set->map[i].mq_map = NULL; | |
3108 | } | |
5676e7b6 RE |
3109 | kfree(set->tags); |
3110 | set->tags = NULL; | |
da695ba2 | 3111 | return ret; |
24d2f903 CH |
3112 | } |
3113 | EXPORT_SYMBOL(blk_mq_alloc_tag_set); | |
3114 | ||
3115 | void blk_mq_free_tag_set(struct blk_mq_tag_set *set) | |
3116 | { | |
b3c661b1 | 3117 | int i, j; |
24d2f903 | 3118 | |
f7e76dbc | 3119 | for (i = 0; i < set->nr_hw_queues; i++) |
cc71a6f4 | 3120 | blk_mq_free_map_and_requests(set, i); |
484b4061 | 3121 | |
b3c661b1 JA |
3122 | for (j = 0; j < set->nr_maps; j++) { |
3123 | kfree(set->map[j].mq_map); | |
3124 | set->map[j].mq_map = NULL; | |
3125 | } | |
bdd17e75 | 3126 | |
981bd189 | 3127 | kfree(set->tags); |
5676e7b6 | 3128 | set->tags = NULL; |
24d2f903 CH |
3129 | } |
3130 | EXPORT_SYMBOL(blk_mq_free_tag_set); | |
3131 | ||
e3a2b3f9 JA |
3132 | int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) |
3133 | { | |
3134 | struct blk_mq_tag_set *set = q->tag_set; | |
3135 | struct blk_mq_hw_ctx *hctx; | |
3136 | int i, ret; | |
3137 | ||
bd166ef1 | 3138 | if (!set) |
e3a2b3f9 JA |
3139 | return -EINVAL; |
3140 | ||
e5fa8140 AZ |
3141 | if (q->nr_requests == nr) |
3142 | return 0; | |
3143 | ||
70f36b60 | 3144 | blk_mq_freeze_queue(q); |
24f5a90f | 3145 | blk_mq_quiesce_queue(q); |
70f36b60 | 3146 | |
e3a2b3f9 JA |
3147 | ret = 0; |
3148 | queue_for_each_hw_ctx(q, hctx, i) { | |
e9137d4b KB |
3149 | if (!hctx->tags) |
3150 | continue; | |
bd166ef1 JA |
3151 | /* |
3152 | * If we're using an MQ scheduler, just update the scheduler | |
3153 | * queue depth. This is similar to what the old code would do. | |
3154 | */ | |
70f36b60 | 3155 | if (!hctx->sched_tags) { |
c2e82a23 | 3156 | ret = blk_mq_tag_update_depth(hctx, &hctx->tags, nr, |
70f36b60 JA |
3157 | false); |
3158 | } else { | |
3159 | ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags, | |
3160 | nr, true); | |
3161 | } | |
e3a2b3f9 JA |
3162 | if (ret) |
3163 | break; | |
77f1e0a5 JA |
3164 | if (q->elevator && q->elevator->type->ops.depth_updated) |
3165 | q->elevator->type->ops.depth_updated(hctx); | |
e3a2b3f9 JA |
3166 | } |
3167 | ||
3168 | if (!ret) | |
3169 | q->nr_requests = nr; | |
3170 | ||
24f5a90f | 3171 | blk_mq_unquiesce_queue(q); |
70f36b60 | 3172 | blk_mq_unfreeze_queue(q); |
70f36b60 | 3173 | |
e3a2b3f9 JA |
3174 | return ret; |
3175 | } | |
3176 | ||
d48ece20 JW |
3177 | /* |
3178 | * request_queue and elevator_type pair. | |
3179 | * It is just used by __blk_mq_update_nr_hw_queues to cache | |
3180 | * the elevator_type associated with a request_queue. | |
3181 | */ | |
3182 | struct blk_mq_qe_pair { | |
3183 | struct list_head node; | |
3184 | struct request_queue *q; | |
3185 | struct elevator_type *type; | |
3186 | }; | |
3187 | ||
3188 | /* | |
3189 | * Cache the elevator_type in qe pair list and switch the | |
3190 | * io scheduler to 'none' | |
3191 | */ | |
3192 | static bool blk_mq_elv_switch_none(struct list_head *head, | |
3193 | struct request_queue *q) | |
3194 | { | |
3195 | struct blk_mq_qe_pair *qe; | |
3196 | ||
3197 | if (!q->elevator) | |
3198 | return true; | |
3199 | ||
3200 | qe = kmalloc(sizeof(*qe), GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY); | |
3201 | if (!qe) | |
3202 | return false; | |
3203 | ||
3204 | INIT_LIST_HEAD(&qe->node); | |
3205 | qe->q = q; | |
3206 | qe->type = q->elevator->type; | |
3207 | list_add(&qe->node, head); | |
3208 | ||
3209 | mutex_lock(&q->sysfs_lock); | |
3210 | /* | |
3211 | * After elevator_switch_mq, the previous elevator_queue will be | |
3212 | * released by elevator_release. The reference of the io scheduler | |
3213 | * module get by elevator_get will also be put. So we need to get | |
3214 | * a reference of the io scheduler module here to prevent it to be | |
3215 | * removed. | |
3216 | */ | |
3217 | __module_get(qe->type->elevator_owner); | |
3218 | elevator_switch_mq(q, NULL); | |
3219 | mutex_unlock(&q->sysfs_lock); | |
3220 | ||
3221 | return true; | |
3222 | } | |
3223 | ||
3224 | static void blk_mq_elv_switch_back(struct list_head *head, | |
3225 | struct request_queue *q) | |
3226 | { | |
3227 | struct blk_mq_qe_pair *qe; | |
3228 | struct elevator_type *t = NULL; | |
3229 | ||
3230 | list_for_each_entry(qe, head, node) | |
3231 | if (qe->q == q) { | |
3232 | t = qe->type; | |
3233 | break; | |
3234 | } | |
3235 | ||
3236 | if (!t) | |
3237 | return; | |
3238 | ||
3239 | list_del(&qe->node); | |
3240 | kfree(qe); | |
3241 | ||
3242 | mutex_lock(&q->sysfs_lock); | |
3243 | elevator_switch_mq(q, t); | |
3244 | mutex_unlock(&q->sysfs_lock); | |
3245 | } | |
3246 | ||
e4dc2b32 KB |
3247 | static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, |
3248 | int nr_hw_queues) | |
868f2f0b KB |
3249 | { |
3250 | struct request_queue *q; | |
d48ece20 | 3251 | LIST_HEAD(head); |
e01ad46d | 3252 | int prev_nr_hw_queues; |
868f2f0b | 3253 | |
705cda97 BVA |
3254 | lockdep_assert_held(&set->tag_list_lock); |
3255 | ||
392546ae | 3256 | if (set->nr_maps == 1 && nr_hw_queues > nr_cpu_ids) |
868f2f0b KB |
3257 | nr_hw_queues = nr_cpu_ids; |
3258 | if (nr_hw_queues < 1 || nr_hw_queues == set->nr_hw_queues) | |
3259 | return; | |
3260 | ||
3261 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
3262 | blk_mq_freeze_queue(q); | |
d48ece20 JW |
3263 | /* |
3264 | * Switch IO scheduler to 'none', cleaning up the data associated | |
3265 | * with the previous scheduler. We will switch back once we are done | |
3266 | * updating the new sw to hw queue mappings. | |
3267 | */ | |
3268 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
3269 | if (!blk_mq_elv_switch_none(&head, q)) | |
3270 | goto switch_back; | |
868f2f0b | 3271 | |
477e19de JW |
3272 | list_for_each_entry(q, &set->tag_list, tag_set_list) { |
3273 | blk_mq_debugfs_unregister_hctxs(q); | |
3274 | blk_mq_sysfs_unregister(q); | |
3275 | } | |
3276 | ||
f7e76dbc BVA |
3277 | if (blk_mq_realloc_tag_set_tags(set, set->nr_hw_queues, nr_hw_queues) < |
3278 | 0) | |
3279 | goto reregister; | |
3280 | ||
e01ad46d | 3281 | prev_nr_hw_queues = set->nr_hw_queues; |
868f2f0b | 3282 | set->nr_hw_queues = nr_hw_queues; |
ebe8bddb | 3283 | blk_mq_update_queue_map(set); |
e01ad46d | 3284 | fallback: |
868f2f0b KB |
3285 | list_for_each_entry(q, &set->tag_list, tag_set_list) { |
3286 | blk_mq_realloc_hw_ctxs(set, q); | |
e01ad46d JW |
3287 | if (q->nr_hw_queues != set->nr_hw_queues) { |
3288 | pr_warn("Increasing nr_hw_queues to %d fails, fallback to %d\n", | |
3289 | nr_hw_queues, prev_nr_hw_queues); | |
3290 | set->nr_hw_queues = prev_nr_hw_queues; | |
7d76f856 | 3291 | blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]); |
e01ad46d JW |
3292 | goto fallback; |
3293 | } | |
477e19de JW |
3294 | blk_mq_map_swqueue(q); |
3295 | } | |
3296 | ||
f7e76dbc | 3297 | reregister: |
477e19de JW |
3298 | list_for_each_entry(q, &set->tag_list, tag_set_list) { |
3299 | blk_mq_sysfs_register(q); | |
3300 | blk_mq_debugfs_register_hctxs(q); | |
868f2f0b KB |
3301 | } |
3302 | ||
d48ece20 JW |
3303 | switch_back: |
3304 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
3305 | blk_mq_elv_switch_back(&head, q); | |
3306 | ||
868f2f0b KB |
3307 | list_for_each_entry(q, &set->tag_list, tag_set_list) |
3308 | blk_mq_unfreeze_queue(q); | |
3309 | } | |
e4dc2b32 KB |
3310 | |
3311 | void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues) | |
3312 | { | |
3313 | mutex_lock(&set->tag_list_lock); | |
3314 | __blk_mq_update_nr_hw_queues(set, nr_hw_queues); | |
3315 | mutex_unlock(&set->tag_list_lock); | |
3316 | } | |
868f2f0b KB |
3317 | EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues); |
3318 | ||
34dbad5d OS |
3319 | /* Enable polling stats and return whether they were already enabled. */ |
3320 | static bool blk_poll_stats_enable(struct request_queue *q) | |
3321 | { | |
3322 | if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags) || | |
7dfdbc73 | 3323 | blk_queue_flag_test_and_set(QUEUE_FLAG_POLL_STATS, q)) |
34dbad5d OS |
3324 | return true; |
3325 | blk_stat_add_callback(q, q->poll_cb); | |
3326 | return false; | |
3327 | } | |
3328 | ||
3329 | static void blk_mq_poll_stats_start(struct request_queue *q) | |
3330 | { | |
3331 | /* | |
3332 | * We don't arm the callback if polling stats are not enabled or the | |
3333 | * callback is already active. | |
3334 | */ | |
3335 | if (!test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags) || | |
3336 | blk_stat_is_active(q->poll_cb)) | |
3337 | return; | |
3338 | ||
3339 | blk_stat_activate_msecs(q->poll_cb, 100); | |
3340 | } | |
3341 | ||
3342 | static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb) | |
3343 | { | |
3344 | struct request_queue *q = cb->data; | |
720b8ccc | 3345 | int bucket; |
34dbad5d | 3346 | |
720b8ccc SB |
3347 | for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS; bucket++) { |
3348 | if (cb->stat[bucket].nr_samples) | |
3349 | q->poll_stat[bucket] = cb->stat[bucket]; | |
3350 | } | |
34dbad5d OS |
3351 | } |
3352 | ||
64f1c21e JA |
3353 | static unsigned long blk_mq_poll_nsecs(struct request_queue *q, |
3354 | struct blk_mq_hw_ctx *hctx, | |
3355 | struct request *rq) | |
3356 | { | |
64f1c21e | 3357 | unsigned long ret = 0; |
720b8ccc | 3358 | int bucket; |
64f1c21e JA |
3359 | |
3360 | /* | |
3361 | * If stats collection isn't on, don't sleep but turn it on for | |
3362 | * future users | |
3363 | */ | |
34dbad5d | 3364 | if (!blk_poll_stats_enable(q)) |
64f1c21e JA |
3365 | return 0; |
3366 | ||
64f1c21e JA |
3367 | /* |
3368 | * As an optimistic guess, use half of the mean service time | |
3369 | * for this type of request. We can (and should) make this smarter. | |
3370 | * For instance, if the completion latencies are tight, we can | |
3371 | * get closer than just half the mean. This is especially | |
3372 | * important on devices where the completion latencies are longer | |
720b8ccc SB |
3373 | * than ~10 usec. We do use the stats for the relevant IO size |
3374 | * if available which does lead to better estimates. | |
64f1c21e | 3375 | */ |
720b8ccc SB |
3376 | bucket = blk_mq_poll_stats_bkt(rq); |
3377 | if (bucket < 0) | |
3378 | return ret; | |
3379 | ||
3380 | if (q->poll_stat[bucket].nr_samples) | |
3381 | ret = (q->poll_stat[bucket].mean + 1) / 2; | |
64f1c21e JA |
3382 | |
3383 | return ret; | |
3384 | } | |
3385 | ||
06426adf | 3386 | static bool blk_mq_poll_hybrid_sleep(struct request_queue *q, |
64f1c21e | 3387 | struct blk_mq_hw_ctx *hctx, |
06426adf JA |
3388 | struct request *rq) |
3389 | { | |
3390 | struct hrtimer_sleeper hs; | |
3391 | enum hrtimer_mode mode; | |
64f1c21e | 3392 | unsigned int nsecs; |
06426adf JA |
3393 | ktime_t kt; |
3394 | ||
76a86f9d | 3395 | if (rq->rq_flags & RQF_MQ_POLL_SLEPT) |
64f1c21e JA |
3396 | return false; |
3397 | ||
3398 | /* | |
1052b8ac | 3399 | * If we get here, hybrid polling is enabled. Hence poll_nsec can be: |
64f1c21e | 3400 | * |
64f1c21e JA |
3401 | * 0: use half of prev avg |
3402 | * >0: use this specific value | |
3403 | */ | |
1052b8ac | 3404 | if (q->poll_nsec > 0) |
64f1c21e JA |
3405 | nsecs = q->poll_nsec; |
3406 | else | |
3407 | nsecs = blk_mq_poll_nsecs(q, hctx, rq); | |
3408 | ||
3409 | if (!nsecs) | |
06426adf JA |
3410 | return false; |
3411 | ||
76a86f9d | 3412 | rq->rq_flags |= RQF_MQ_POLL_SLEPT; |
06426adf JA |
3413 | |
3414 | /* | |
3415 | * This will be replaced with the stats tracking code, using | |
3416 | * 'avg_completion_time / 2' as the pre-sleep target. | |
3417 | */ | |
8b0e1953 | 3418 | kt = nsecs; |
06426adf JA |
3419 | |
3420 | mode = HRTIMER_MODE_REL; | |
dbc1625f | 3421 | hrtimer_init_sleeper_on_stack(&hs, CLOCK_MONOTONIC, mode); |
06426adf JA |
3422 | hrtimer_set_expires(&hs.timer, kt); |
3423 | ||
06426adf | 3424 | do { |
5a61c363 | 3425 | if (blk_mq_rq_state(rq) == MQ_RQ_COMPLETE) |
06426adf JA |
3426 | break; |
3427 | set_current_state(TASK_UNINTERRUPTIBLE); | |
9dd8813e | 3428 | hrtimer_sleeper_start_expires(&hs, mode); |
06426adf JA |
3429 | if (hs.task) |
3430 | io_schedule(); | |
3431 | hrtimer_cancel(&hs.timer); | |
3432 | mode = HRTIMER_MODE_ABS; | |
3433 | } while (hs.task && !signal_pending(current)); | |
3434 | ||
3435 | __set_current_state(TASK_RUNNING); | |
3436 | destroy_hrtimer_on_stack(&hs.timer); | |
3437 | return true; | |
3438 | } | |
3439 | ||
1052b8ac JA |
3440 | static bool blk_mq_poll_hybrid(struct request_queue *q, |
3441 | struct blk_mq_hw_ctx *hctx, blk_qc_t cookie) | |
bbd7bb70 | 3442 | { |
1052b8ac JA |
3443 | struct request *rq; |
3444 | ||
29ece8b4 | 3445 | if (q->poll_nsec == BLK_MQ_POLL_CLASSIC) |
1052b8ac JA |
3446 | return false; |
3447 | ||
3448 | if (!blk_qc_t_is_internal(cookie)) | |
3449 | rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie)); | |
3450 | else { | |
3451 | rq = blk_mq_tag_to_rq(hctx->sched_tags, blk_qc_t_to_tag(cookie)); | |
3452 | /* | |
3453 | * With scheduling, if the request has completed, we'll | |
3454 | * get a NULL return here, as we clear the sched tag when | |
3455 | * that happens. The request still remains valid, like always, | |
3456 | * so we should be safe with just the NULL check. | |
3457 | */ | |
3458 | if (!rq) | |
3459 | return false; | |
3460 | } | |
3461 | ||
3462 | return blk_mq_poll_hybrid_sleep(q, hctx, rq); | |
3463 | } | |
3464 | ||
529262d5 CH |
3465 | /** |
3466 | * blk_poll - poll for IO completions | |
3467 | * @q: the queue | |
3468 | * @cookie: cookie passed back at IO submission time | |
3469 | * @spin: whether to spin for completions | |
3470 | * | |
3471 | * Description: | |
3472 | * Poll for completions on the passed in queue. Returns number of | |
3473 | * completed entries found. If @spin is true, then blk_poll will continue | |
3474 | * looping until at least one completion is found, unless the task is | |
3475 | * otherwise marked running (or we need to reschedule). | |
3476 | */ | |
3477 | int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin) | |
1052b8ac JA |
3478 | { |
3479 | struct blk_mq_hw_ctx *hctx; | |
bbd7bb70 JA |
3480 | long state; |
3481 | ||
529262d5 CH |
3482 | if (!blk_qc_t_valid(cookie) || |
3483 | !test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) | |
1052b8ac JA |
3484 | return 0; |
3485 | ||
529262d5 CH |
3486 | if (current->plug) |
3487 | blk_flush_plug_list(current->plug, false); | |
3488 | ||
1052b8ac JA |
3489 | hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)]; |
3490 | ||
06426adf JA |
3491 | /* |
3492 | * If we sleep, have the caller restart the poll loop to reset | |
3493 | * the state. Like for the other success return cases, the | |
3494 | * caller is responsible for checking if the IO completed. If | |
3495 | * the IO isn't complete, we'll get called again and will go | |
3496 | * straight to the busy poll loop. | |
3497 | */ | |
1052b8ac | 3498 | if (blk_mq_poll_hybrid(q, hctx, cookie)) |
85f4d4b6 | 3499 | return 1; |
06426adf | 3500 | |
bbd7bb70 JA |
3501 | hctx->poll_considered++; |
3502 | ||
3503 | state = current->state; | |
aa61bec3 | 3504 | do { |
bbd7bb70 JA |
3505 | int ret; |
3506 | ||
3507 | hctx->poll_invoked++; | |
3508 | ||
9743139c | 3509 | ret = q->mq_ops->poll(hctx); |
bbd7bb70 JA |
3510 | if (ret > 0) { |
3511 | hctx->poll_success++; | |
849a3700 | 3512 | __set_current_state(TASK_RUNNING); |
85f4d4b6 | 3513 | return ret; |
bbd7bb70 JA |
3514 | } |
3515 | ||
3516 | if (signal_pending_state(state, current)) | |
849a3700 | 3517 | __set_current_state(TASK_RUNNING); |
bbd7bb70 JA |
3518 | |
3519 | if (current->state == TASK_RUNNING) | |
85f4d4b6 | 3520 | return 1; |
0a1b8b87 | 3521 | if (ret < 0 || !spin) |
bbd7bb70 JA |
3522 | break; |
3523 | cpu_relax(); | |
aa61bec3 | 3524 | } while (!need_resched()); |
bbd7bb70 | 3525 | |
67b4110f | 3526 | __set_current_state(TASK_RUNNING); |
85f4d4b6 | 3527 | return 0; |
bbd7bb70 | 3528 | } |
529262d5 | 3529 | EXPORT_SYMBOL_GPL(blk_poll); |
bbd7bb70 | 3530 | |
9cf2bab6 JA |
3531 | unsigned int blk_mq_rq_cpu(struct request *rq) |
3532 | { | |
3533 | return rq->mq_ctx->cpu; | |
3534 | } | |
3535 | EXPORT_SYMBOL(blk_mq_rq_cpu); | |
3536 | ||
320ae51f JA |
3537 | static int __init blk_mq_init(void) |
3538 | { | |
9467f859 TG |
3539 | cpuhp_setup_state_multi(CPUHP_BLK_MQ_DEAD, "block/mq:dead", NULL, |
3540 | blk_mq_hctx_notify_dead); | |
320ae51f JA |
3541 | return 0; |
3542 | } | |
3543 | subsys_initcall(blk_mq_init); |