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> |
a892c8d5 | 29 | #include <linux/blk-crypto.h> |
320ae51f JA |
30 | |
31 | #include <trace/events/block.h> | |
32 | ||
33 | #include <linux/blk-mq.h> | |
54d4e6ab | 34 | #include <linux/t10-pi.h> |
320ae51f JA |
35 | #include "blk.h" |
36 | #include "blk-mq.h" | |
9c1051aa | 37 | #include "blk-mq-debugfs.h" |
320ae51f | 38 | #include "blk-mq-tag.h" |
986d413b | 39 | #include "blk-pm.h" |
cf43e6be | 40 | #include "blk-stat.h" |
bd166ef1 | 41 | #include "blk-mq-sched.h" |
c1c80384 | 42 | #include "blk-rq-qos.h" |
320ae51f | 43 | |
f9ab4918 | 44 | static DEFINE_PER_CPU(struct llist_head, blk_cpu_done); |
c3077b5d | 45 | |
34dbad5d OS |
46 | static void blk_mq_poll_stats_start(struct request_queue *q); |
47 | static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb); | |
48 | ||
720b8ccc SB |
49 | static int blk_mq_poll_stats_bkt(const struct request *rq) |
50 | { | |
3d244306 | 51 | int ddir, sectors, bucket; |
720b8ccc | 52 | |
99c749a4 | 53 | ddir = rq_data_dir(rq); |
3d244306 | 54 | sectors = blk_rq_stats_sectors(rq); |
720b8ccc | 55 | |
3d244306 | 56 | bucket = ddir + 2 * ilog2(sectors); |
720b8ccc SB |
57 | |
58 | if (bucket < 0) | |
59 | return -1; | |
60 | else if (bucket >= BLK_MQ_POLL_STATS_BKTS) | |
61 | return ddir + BLK_MQ_POLL_STATS_BKTS - 2; | |
62 | ||
63 | return bucket; | |
64 | } | |
65 | ||
320ae51f | 66 | /* |
85fae294 YY |
67 | * Check if any of the ctx, dispatch list or elevator |
68 | * have pending work in this hardware queue. | |
320ae51f | 69 | */ |
79f720a7 | 70 | static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx) |
320ae51f | 71 | { |
79f720a7 JA |
72 | return !list_empty_careful(&hctx->dispatch) || |
73 | sbitmap_any_bit_set(&hctx->ctx_map) || | |
bd166ef1 | 74 | blk_mq_sched_has_work(hctx); |
1429d7c9 JA |
75 | } |
76 | ||
320ae51f JA |
77 | /* |
78 | * Mark this ctx as having pending work in this hardware queue | |
79 | */ | |
80 | static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx, | |
81 | struct blk_mq_ctx *ctx) | |
82 | { | |
f31967f0 JA |
83 | const int bit = ctx->index_hw[hctx->type]; |
84 | ||
85 | if (!sbitmap_test_bit(&hctx->ctx_map, bit)) | |
86 | sbitmap_set_bit(&hctx->ctx_map, bit); | |
1429d7c9 JA |
87 | } |
88 | ||
89 | static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx, | |
90 | struct blk_mq_ctx *ctx) | |
91 | { | |
f31967f0 JA |
92 | const int bit = ctx->index_hw[hctx->type]; |
93 | ||
94 | sbitmap_clear_bit(&hctx->ctx_map, bit); | |
320ae51f JA |
95 | } |
96 | ||
f299b7c7 | 97 | struct mq_inflight { |
8446fe92 | 98 | struct block_device *part; |
a2e80f6f | 99 | unsigned int inflight[2]; |
f299b7c7 JA |
100 | }; |
101 | ||
7baa8572 | 102 | static bool blk_mq_check_inflight(struct blk_mq_hw_ctx *hctx, |
f299b7c7 JA |
103 | struct request *rq, void *priv, |
104 | bool reserved) | |
105 | { | |
106 | struct mq_inflight *mi = priv; | |
107 | ||
b0d97557 JX |
108 | if ((!mi->part->bd_partno || rq->part == mi->part) && |
109 | blk_mq_rq_state(rq) == MQ_RQ_IN_FLIGHT) | |
bb4e6b14 | 110 | mi->inflight[rq_data_dir(rq)]++; |
7baa8572 JA |
111 | |
112 | return true; | |
f299b7c7 JA |
113 | } |
114 | ||
8446fe92 CH |
115 | unsigned int blk_mq_in_flight(struct request_queue *q, |
116 | struct block_device *part) | |
f299b7c7 | 117 | { |
a2e80f6f | 118 | struct mq_inflight mi = { .part = part }; |
f299b7c7 | 119 | |
f299b7c7 | 120 | blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi); |
e016b782 | 121 | |
a2e80f6f | 122 | return mi.inflight[0] + mi.inflight[1]; |
bf0ddaba OS |
123 | } |
124 | ||
8446fe92 CH |
125 | void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part, |
126 | unsigned int inflight[2]) | |
bf0ddaba | 127 | { |
a2e80f6f | 128 | struct mq_inflight mi = { .part = part }; |
bf0ddaba | 129 | |
bb4e6b14 | 130 | blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi); |
a2e80f6f PB |
131 | inflight[0] = mi.inflight[0]; |
132 | inflight[1] = mi.inflight[1]; | |
bf0ddaba OS |
133 | } |
134 | ||
1671d522 | 135 | void blk_freeze_queue_start(struct request_queue *q) |
43a5e4e2 | 136 | { |
7996a8b5 BL |
137 | mutex_lock(&q->mq_freeze_lock); |
138 | if (++q->mq_freeze_depth == 1) { | |
3ef28e83 | 139 | percpu_ref_kill(&q->q_usage_counter); |
7996a8b5 | 140 | mutex_unlock(&q->mq_freeze_lock); |
344e9ffc | 141 | if (queue_is_mq(q)) |
055f6e18 | 142 | blk_mq_run_hw_queues(q, false); |
7996a8b5 BL |
143 | } else { |
144 | mutex_unlock(&q->mq_freeze_lock); | |
cddd5d17 | 145 | } |
f3af020b | 146 | } |
1671d522 | 147 | EXPORT_SYMBOL_GPL(blk_freeze_queue_start); |
f3af020b | 148 | |
6bae363e | 149 | void blk_mq_freeze_queue_wait(struct request_queue *q) |
f3af020b | 150 | { |
3ef28e83 | 151 | wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter)); |
43a5e4e2 | 152 | } |
6bae363e | 153 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait); |
43a5e4e2 | 154 | |
f91328c4 KB |
155 | int blk_mq_freeze_queue_wait_timeout(struct request_queue *q, |
156 | unsigned long timeout) | |
157 | { | |
158 | return wait_event_timeout(q->mq_freeze_wq, | |
159 | percpu_ref_is_zero(&q->q_usage_counter), | |
160 | timeout); | |
161 | } | |
162 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait_timeout); | |
43a5e4e2 | 163 | |
f3af020b TH |
164 | /* |
165 | * Guarantee no request is in use, so we can change any data structure of | |
166 | * the queue afterward. | |
167 | */ | |
3ef28e83 | 168 | void blk_freeze_queue(struct request_queue *q) |
f3af020b | 169 | { |
3ef28e83 DW |
170 | /* |
171 | * In the !blk_mq case we are only calling this to kill the | |
172 | * q_usage_counter, otherwise this increases the freeze depth | |
173 | * and waits for it to return to zero. For this reason there is | |
174 | * no blk_unfreeze_queue(), and blk_freeze_queue() is not | |
175 | * exported to drivers as the only user for unfreeze is blk_mq. | |
176 | */ | |
1671d522 | 177 | blk_freeze_queue_start(q); |
f3af020b TH |
178 | blk_mq_freeze_queue_wait(q); |
179 | } | |
3ef28e83 DW |
180 | |
181 | void blk_mq_freeze_queue(struct request_queue *q) | |
182 | { | |
183 | /* | |
184 | * ...just an alias to keep freeze and unfreeze actions balanced | |
185 | * in the blk_mq_* namespace | |
186 | */ | |
187 | blk_freeze_queue(q); | |
188 | } | |
c761d96b | 189 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue); |
f3af020b | 190 | |
b4c6a028 | 191 | void blk_mq_unfreeze_queue(struct request_queue *q) |
320ae51f | 192 | { |
7996a8b5 BL |
193 | mutex_lock(&q->mq_freeze_lock); |
194 | q->mq_freeze_depth--; | |
195 | WARN_ON_ONCE(q->mq_freeze_depth < 0); | |
196 | if (!q->mq_freeze_depth) { | |
bdd63160 | 197 | percpu_ref_resurrect(&q->q_usage_counter); |
320ae51f | 198 | wake_up_all(&q->mq_freeze_wq); |
add703fd | 199 | } |
7996a8b5 | 200 | mutex_unlock(&q->mq_freeze_lock); |
320ae51f | 201 | } |
b4c6a028 | 202 | EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue); |
320ae51f | 203 | |
852ec809 BVA |
204 | /* |
205 | * FIXME: replace the scsi_internal_device_*block_nowait() calls in the | |
206 | * mpt3sas driver such that this function can be removed. | |
207 | */ | |
208 | void blk_mq_quiesce_queue_nowait(struct request_queue *q) | |
209 | { | |
8814ce8a | 210 | blk_queue_flag_set(QUEUE_FLAG_QUIESCED, q); |
852ec809 BVA |
211 | } |
212 | EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue_nowait); | |
213 | ||
6a83e74d | 214 | /** |
69e07c4a | 215 | * blk_mq_quiesce_queue() - wait until all ongoing dispatches have finished |
6a83e74d BVA |
216 | * @q: request queue. |
217 | * | |
218 | * Note: this function does not prevent that the struct request end_io() | |
69e07c4a ML |
219 | * callback function is invoked. Once this function is returned, we make |
220 | * sure no dispatch can happen until the queue is unquiesced via | |
221 | * blk_mq_unquiesce_queue(). | |
6a83e74d BVA |
222 | */ |
223 | void blk_mq_quiesce_queue(struct request_queue *q) | |
224 | { | |
225 | struct blk_mq_hw_ctx *hctx; | |
226 | unsigned int i; | |
227 | bool rcu = false; | |
228 | ||
1d9e9bc6 | 229 | blk_mq_quiesce_queue_nowait(q); |
f4560ffe | 230 | |
6a83e74d BVA |
231 | queue_for_each_hw_ctx(q, hctx, i) { |
232 | if (hctx->flags & BLK_MQ_F_BLOCKING) | |
05707b64 | 233 | synchronize_srcu(hctx->srcu); |
6a83e74d BVA |
234 | else |
235 | rcu = true; | |
236 | } | |
237 | if (rcu) | |
238 | synchronize_rcu(); | |
239 | } | |
240 | EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue); | |
241 | ||
e4e73913 ML |
242 | /* |
243 | * blk_mq_unquiesce_queue() - counterpart of blk_mq_quiesce_queue() | |
244 | * @q: request queue. | |
245 | * | |
246 | * This function recovers queue into the state before quiescing | |
247 | * which is done by blk_mq_quiesce_queue. | |
248 | */ | |
249 | void blk_mq_unquiesce_queue(struct request_queue *q) | |
250 | { | |
8814ce8a | 251 | blk_queue_flag_clear(QUEUE_FLAG_QUIESCED, q); |
f4560ffe | 252 | |
1d9e9bc6 ML |
253 | /* dispatch requests which are inserted during quiescing */ |
254 | blk_mq_run_hw_queues(q, true); | |
e4e73913 ML |
255 | } |
256 | EXPORT_SYMBOL_GPL(blk_mq_unquiesce_queue); | |
257 | ||
aed3ea94 JA |
258 | void blk_mq_wake_waiters(struct request_queue *q) |
259 | { | |
260 | struct blk_mq_hw_ctx *hctx; | |
261 | unsigned int i; | |
262 | ||
263 | queue_for_each_hw_ctx(q, hctx, i) | |
264 | if (blk_mq_hw_queue_mapped(hctx)) | |
265 | blk_mq_tag_wakeup_all(hctx->tags, true); | |
266 | } | |
267 | ||
fe1f4526 | 268 | /* |
9a91b05b HT |
269 | * Only need start/end time stamping if we have iostat or |
270 | * blk stats enabled, or using an IO scheduler. | |
fe1f4526 JA |
271 | */ |
272 | static inline bool blk_mq_need_time_stamp(struct request *rq) | |
273 | { | |
9a91b05b | 274 | return (rq->rq_flags & (RQF_IO_STAT | RQF_STATS)) || rq->q->elevator; |
fe1f4526 JA |
275 | } |
276 | ||
e4cdf1a1 | 277 | static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data, |
7ea4d8a4 | 278 | unsigned int tag, u64 alloc_time_ns) |
320ae51f | 279 | { |
e4cdf1a1 CH |
280 | struct blk_mq_tags *tags = blk_mq_tags_from_data(data); |
281 | struct request *rq = tags->static_rqs[tag]; | |
c3a148d2 | 282 | |
42fdc5e4 | 283 | if (data->q->elevator) { |
76647368 | 284 | rq->tag = BLK_MQ_NO_TAG; |
e4cdf1a1 CH |
285 | rq->internal_tag = tag; |
286 | } else { | |
e4cdf1a1 | 287 | rq->tag = tag; |
76647368 | 288 | rq->internal_tag = BLK_MQ_NO_TAG; |
e4cdf1a1 CH |
289 | } |
290 | ||
af76e555 | 291 | /* csd/requeue_work/fifo_time is initialized before use */ |
e4cdf1a1 CH |
292 | rq->q = data->q; |
293 | rq->mq_ctx = data->ctx; | |
ea4f995e | 294 | rq->mq_hctx = data->hctx; |
568f2700 | 295 | rq->rq_flags = 0; |
7ea4d8a4 | 296 | rq->cmd_flags = data->cmd_flags; |
0854bcdc BVA |
297 | if (data->flags & BLK_MQ_REQ_PM) |
298 | rq->rq_flags |= RQF_PM; | |
e4cdf1a1 | 299 | if (blk_queue_io_stat(data->q)) |
e8064021 | 300 | rq->rq_flags |= RQF_IO_STAT; |
7c3fb70f | 301 | INIT_LIST_HEAD(&rq->queuelist); |
af76e555 CH |
302 | INIT_HLIST_NODE(&rq->hash); |
303 | RB_CLEAR_NODE(&rq->rb_node); | |
af76e555 CH |
304 | rq->rq_disk = NULL; |
305 | rq->part = NULL; | |
6f816b4b TH |
306 | #ifdef CONFIG_BLK_RQ_ALLOC_TIME |
307 | rq->alloc_time_ns = alloc_time_ns; | |
308 | #endif | |
fe1f4526 JA |
309 | if (blk_mq_need_time_stamp(rq)) |
310 | rq->start_time_ns = ktime_get_ns(); | |
311 | else | |
312 | rq->start_time_ns = 0; | |
544ccc8d | 313 | rq->io_start_time_ns = 0; |
3d244306 | 314 | rq->stats_sectors = 0; |
af76e555 CH |
315 | rq->nr_phys_segments = 0; |
316 | #if defined(CONFIG_BLK_DEV_INTEGRITY) | |
317 | rq->nr_integrity_segments = 0; | |
318 | #endif | |
a892c8d5 | 319 | blk_crypto_rq_set_defaults(rq); |
af76e555 | 320 | /* tag was already set */ |
079076b3 | 321 | WRITE_ONCE(rq->deadline, 0); |
af76e555 | 322 | |
f6be4fb4 JA |
323 | rq->timeout = 0; |
324 | ||
af76e555 CH |
325 | rq->end_io = NULL; |
326 | rq->end_io_data = NULL; | |
af76e555 | 327 | |
7ea4d8a4 | 328 | data->ctx->rq_dispatched[op_is_sync(data->cmd_flags)]++; |
12f5b931 | 329 | refcount_set(&rq->ref, 1); |
7ea4d8a4 CH |
330 | |
331 | if (!op_is_flush(data->cmd_flags)) { | |
332 | struct elevator_queue *e = data->q->elevator; | |
333 | ||
334 | rq->elv.icq = NULL; | |
335 | if (e && e->type->ops.prepare_request) { | |
336 | if (e->type->icq_cache) | |
337 | blk_mq_sched_assign_ioc(rq); | |
338 | ||
339 | e->type->ops.prepare_request(rq); | |
340 | rq->rq_flags |= RQF_ELVPRIV; | |
341 | } | |
342 | } | |
343 | ||
344 | data->hctx->queued++; | |
e4cdf1a1 | 345 | return rq; |
5dee8577 CH |
346 | } |
347 | ||
e6e7abff | 348 | static struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data) |
d2c0d383 | 349 | { |
e6e7abff | 350 | struct request_queue *q = data->q; |
d2c0d383 | 351 | struct elevator_queue *e = q->elevator; |
6f816b4b | 352 | u64 alloc_time_ns = 0; |
600c3b0c | 353 | unsigned int tag; |
d2c0d383 | 354 | |
6f816b4b TH |
355 | /* alloc_time includes depth and tag waits */ |
356 | if (blk_queue_rq_alloc_time(q)) | |
357 | alloc_time_ns = ktime_get_ns(); | |
358 | ||
f9afca4d | 359 | if (data->cmd_flags & REQ_NOWAIT) |
03a07c92 | 360 | data->flags |= BLK_MQ_REQ_NOWAIT; |
d2c0d383 CH |
361 | |
362 | if (e) { | |
d2c0d383 | 363 | /* |
8d663f34 | 364 | * Flush/passthrough requests are special and go directly to the |
17a51199 JA |
365 | * dispatch list. Don't include reserved tags in the |
366 | * limiting, as it isn't useful. | |
d2c0d383 | 367 | */ |
f9afca4d | 368 | if (!op_is_flush(data->cmd_flags) && |
8d663f34 | 369 | !blk_op_is_passthrough(data->cmd_flags) && |
f9afca4d | 370 | e->type->ops.limit_depth && |
17a51199 | 371 | !(data->flags & BLK_MQ_REQ_RESERVED)) |
f9afca4d | 372 | e->type->ops.limit_depth(data->cmd_flags, data); |
d2c0d383 CH |
373 | } |
374 | ||
bf0beec0 | 375 | retry: |
600c3b0c CH |
376 | data->ctx = blk_mq_get_ctx(q); |
377 | data->hctx = blk_mq_map_queue(q, data->cmd_flags, data->ctx); | |
42fdc5e4 | 378 | if (!e) |
600c3b0c CH |
379 | blk_mq_tag_busy(data->hctx); |
380 | ||
bf0beec0 ML |
381 | /* |
382 | * Waiting allocations only fail because of an inactive hctx. In that | |
383 | * case just retry the hctx assignment and tag allocation as CPU hotplug | |
384 | * should have migrated us to an online CPU by now. | |
385 | */ | |
e4cdf1a1 | 386 | tag = blk_mq_get_tag(data); |
bf0beec0 ML |
387 | if (tag == BLK_MQ_NO_TAG) { |
388 | if (data->flags & BLK_MQ_REQ_NOWAIT) | |
389 | return NULL; | |
390 | ||
391 | /* | |
392 | * Give up the CPU and sleep for a random short time to ensure | |
393 | * that thread using a realtime scheduling class are migrated | |
70f15a4f | 394 | * off the CPU, and thus off the hctx that is going away. |
bf0beec0 ML |
395 | */ |
396 | msleep(3); | |
397 | goto retry; | |
398 | } | |
7ea4d8a4 | 399 | return blk_mq_rq_ctx_init(data, tag, alloc_time_ns); |
d2c0d383 CH |
400 | } |
401 | ||
cd6ce148 | 402 | struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op, |
9a95e4ef | 403 | blk_mq_req_flags_t flags) |
320ae51f | 404 | { |
e6e7abff CH |
405 | struct blk_mq_alloc_data data = { |
406 | .q = q, | |
407 | .flags = flags, | |
408 | .cmd_flags = op, | |
409 | }; | |
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 | |
e6e7abff | 417 | rq = __blk_mq_alloc_request(&data); |
bd166ef1 | 418 | if (!rq) |
a5ea5811 | 419 | goto out_queue_exit; |
0c4de0f3 CH |
420 | rq->__data_len = 0; |
421 | rq->__sector = (sector_t) -1; | |
422 | rq->bio = rq->biotail = NULL; | |
320ae51f | 423 | return rq; |
a5ea5811 CH |
424 | out_queue_exit: |
425 | blk_queue_exit(q); | |
426 | return ERR_PTR(-EWOULDBLOCK); | |
320ae51f | 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 | { |
e6e7abff CH |
433 | struct blk_mq_alloc_data data = { |
434 | .q = q, | |
435 | .flags = flags, | |
436 | .cmd_flags = op, | |
437 | }; | |
600c3b0c | 438 | u64 alloc_time_ns = 0; |
6d2809d5 | 439 | unsigned int cpu; |
600c3b0c | 440 | unsigned int tag; |
1f5bd336 ML |
441 | int ret; |
442 | ||
600c3b0c CH |
443 | /* alloc_time includes depth and tag waits */ |
444 | if (blk_queue_rq_alloc_time(q)) | |
445 | alloc_time_ns = ktime_get_ns(); | |
446 | ||
1f5bd336 ML |
447 | /* |
448 | * If the tag allocator sleeps we could get an allocation for a | |
449 | * different hardware context. No need to complicate the low level | |
450 | * allocator for this for the rare use case of a command tied to | |
451 | * a specific queue. | |
452 | */ | |
600c3b0c | 453 | if (WARN_ON_ONCE(!(flags & (BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED)))) |
1f5bd336 ML |
454 | return ERR_PTR(-EINVAL); |
455 | ||
456 | if (hctx_idx >= q->nr_hw_queues) | |
457 | return ERR_PTR(-EIO); | |
458 | ||
3a0a5299 | 459 | ret = blk_queue_enter(q, flags); |
1f5bd336 ML |
460 | if (ret) |
461 | return ERR_PTR(ret); | |
462 | ||
c8712c6a CH |
463 | /* |
464 | * Check if the hardware context is actually mapped to anything. | |
465 | * If not tell the caller that it should skip this queue. | |
466 | */ | |
a5ea5811 | 467 | ret = -EXDEV; |
e6e7abff CH |
468 | data.hctx = q->queue_hw_ctx[hctx_idx]; |
469 | if (!blk_mq_hw_queue_mapped(data.hctx)) | |
a5ea5811 | 470 | goto out_queue_exit; |
e6e7abff CH |
471 | cpu = cpumask_first_and(data.hctx->cpumask, cpu_online_mask); |
472 | data.ctx = __blk_mq_get_ctx(q, cpu); | |
1f5bd336 | 473 | |
42fdc5e4 | 474 | if (!q->elevator) |
600c3b0c CH |
475 | blk_mq_tag_busy(data.hctx); |
476 | ||
a5ea5811 | 477 | ret = -EWOULDBLOCK; |
600c3b0c CH |
478 | tag = blk_mq_get_tag(&data); |
479 | if (tag == BLK_MQ_NO_TAG) | |
a5ea5811 | 480 | goto out_queue_exit; |
600c3b0c CH |
481 | return blk_mq_rq_ctx_init(&data, tag, alloc_time_ns); |
482 | ||
a5ea5811 CH |
483 | out_queue_exit: |
484 | blk_queue_exit(q); | |
485 | return ERR_PTR(ret); | |
1f5bd336 ML |
486 | } |
487 | EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx); | |
488 | ||
12f5b931 KB |
489 | static void __blk_mq_free_request(struct request *rq) |
490 | { | |
491 | struct request_queue *q = rq->q; | |
492 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
ea4f995e | 493 | struct blk_mq_hw_ctx *hctx = rq->mq_hctx; |
12f5b931 KB |
494 | const int sched_tag = rq->internal_tag; |
495 | ||
a892c8d5 | 496 | blk_crypto_free_request(rq); |
986d413b | 497 | blk_pm_mark_last_busy(rq); |
ea4f995e | 498 | rq->mq_hctx = NULL; |
76647368 | 499 | if (rq->tag != BLK_MQ_NO_TAG) |
cae740a0 | 500 | blk_mq_put_tag(hctx->tags, ctx, rq->tag); |
76647368 | 501 | if (sched_tag != BLK_MQ_NO_TAG) |
cae740a0 | 502 | blk_mq_put_tag(hctx->sched_tags, ctx, sched_tag); |
12f5b931 KB |
503 | blk_mq_sched_restart(hctx); |
504 | blk_queue_exit(q); | |
505 | } | |
506 | ||
6af54051 | 507 | void blk_mq_free_request(struct request *rq) |
320ae51f | 508 | { |
320ae51f | 509 | struct request_queue *q = rq->q; |
6af54051 CH |
510 | struct elevator_queue *e = q->elevator; |
511 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
ea4f995e | 512 | struct blk_mq_hw_ctx *hctx = rq->mq_hctx; |
6af54051 | 513 | |
5bbf4e5a | 514 | if (rq->rq_flags & RQF_ELVPRIV) { |
f9cd4bfe JA |
515 | if (e && e->type->ops.finish_request) |
516 | e->type->ops.finish_request(rq); | |
6af54051 CH |
517 | if (rq->elv.icq) { |
518 | put_io_context(rq->elv.icq->ioc); | |
519 | rq->elv.icq = NULL; | |
520 | } | |
521 | } | |
320ae51f | 522 | |
6af54051 | 523 | ctx->rq_completed[rq_is_sync(rq)]++; |
e8064021 | 524 | if (rq->rq_flags & RQF_MQ_INFLIGHT) |
bccf5e26 | 525 | __blk_mq_dec_active_requests(hctx); |
87760e5e | 526 | |
7beb2f84 JA |
527 | if (unlikely(laptop_mode && !blk_rq_is_passthrough(rq))) |
528 | laptop_io_completion(q->backing_dev_info); | |
529 | ||
a7905043 | 530 | rq_qos_done(q, rq); |
0d2602ca | 531 | |
12f5b931 KB |
532 | WRITE_ONCE(rq->state, MQ_RQ_IDLE); |
533 | if (refcount_dec_and_test(&rq->ref)) | |
534 | __blk_mq_free_request(rq); | |
320ae51f | 535 | } |
1a3b595a | 536 | EXPORT_SYMBOL_GPL(blk_mq_free_request); |
320ae51f | 537 | |
2a842aca | 538 | inline void __blk_mq_end_request(struct request *rq, blk_status_t error) |
320ae51f | 539 | { |
fe1f4526 JA |
540 | u64 now = 0; |
541 | ||
542 | if (blk_mq_need_time_stamp(rq)) | |
543 | now = ktime_get_ns(); | |
522a7775 | 544 | |
4bc6339a OS |
545 | if (rq->rq_flags & RQF_STATS) { |
546 | blk_mq_poll_stats_start(rq->q); | |
522a7775 | 547 | blk_stat_add(rq, now); |
4bc6339a OS |
548 | } |
549 | ||
87890092 | 550 | blk_mq_sched_completed_request(rq, now); |
ed88660a | 551 | |
522a7775 | 552 | blk_account_io_done(rq, now); |
0d11e6ac | 553 | |
91b63639 | 554 | if (rq->end_io) { |
a7905043 | 555 | rq_qos_done(rq->q, rq); |
320ae51f | 556 | rq->end_io(rq, error); |
91b63639 | 557 | } else { |
320ae51f | 558 | blk_mq_free_request(rq); |
91b63639 | 559 | } |
320ae51f | 560 | } |
c8a446ad | 561 | EXPORT_SYMBOL(__blk_mq_end_request); |
63151a44 | 562 | |
2a842aca | 563 | void blk_mq_end_request(struct request *rq, blk_status_t error) |
63151a44 CH |
564 | { |
565 | if (blk_update_request(rq, error, blk_rq_bytes(rq))) | |
566 | BUG(); | |
c8a446ad | 567 | __blk_mq_end_request(rq, error); |
63151a44 | 568 | } |
c8a446ad | 569 | EXPORT_SYMBOL(blk_mq_end_request); |
320ae51f | 570 | |
f9ab4918 | 571 | static void blk_complete_reqs(struct llist_head *list) |
320ae51f | 572 | { |
f9ab4918 SAS |
573 | struct llist_node *entry = llist_reverse_order(llist_del_all(list)); |
574 | struct request *rq, *next; | |
c3077b5d | 575 | |
f9ab4918 | 576 | llist_for_each_entry_safe(rq, next, entry, ipi_list) |
c3077b5d | 577 | rq->q->mq_ops->complete(rq); |
320ae51f | 578 | } |
320ae51f | 579 | |
f9ab4918 | 580 | static __latent_entropy void blk_done_softirq(struct softirq_action *h) |
320ae51f | 581 | { |
f9ab4918 | 582 | blk_complete_reqs(this_cpu_ptr(&blk_cpu_done)); |
115243f5 CH |
583 | } |
584 | ||
c3077b5d CH |
585 | static int blk_softirq_cpu_dead(unsigned int cpu) |
586 | { | |
f9ab4918 | 587 | blk_complete_reqs(&per_cpu(blk_cpu_done, cpu)); |
c3077b5d CH |
588 | return 0; |
589 | } | |
590 | ||
40d09b53 | 591 | static void __blk_mq_complete_request_remote(void *data) |
c3077b5d | 592 | { |
f9ab4918 | 593 | __raise_softirq_irqoff(BLOCK_SOFTIRQ); |
c3077b5d CH |
594 | } |
595 | ||
96339526 CH |
596 | static inline bool blk_mq_complete_need_ipi(struct request *rq) |
597 | { | |
598 | int cpu = raw_smp_processor_id(); | |
599 | ||
600 | if (!IS_ENABLED(CONFIG_SMP) || | |
601 | !test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) | |
602 | return false; | |
71425189 SAS |
603 | /* |
604 | * With force threaded interrupts enabled, raising softirq from an SMP | |
605 | * function call will always result in waking the ksoftirqd thread. | |
606 | * This is probably worse than completing the request on a different | |
607 | * cache domain. | |
608 | */ | |
609 | if (force_irqthreads) | |
610 | return false; | |
96339526 CH |
611 | |
612 | /* same CPU or cache domain? Complete locally */ | |
613 | if (cpu == rq->mq_ctx->cpu || | |
614 | (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags) && | |
615 | cpus_share_cache(cpu, rq->mq_ctx->cpu))) | |
616 | return false; | |
617 | ||
618 | /* don't try to IPI to an offline CPU */ | |
619 | return cpu_online(rq->mq_ctx->cpu); | |
620 | } | |
621 | ||
f9ab4918 SAS |
622 | static void blk_mq_complete_send_ipi(struct request *rq) |
623 | { | |
624 | struct llist_head *list; | |
625 | unsigned int cpu; | |
626 | ||
627 | cpu = rq->mq_ctx->cpu; | |
628 | list = &per_cpu(blk_cpu_done, cpu); | |
629 | if (llist_add(&rq->ipi_list, list)) { | |
630 | INIT_CSD(&rq->csd, __blk_mq_complete_request_remote, rq); | |
631 | smp_call_function_single_async(cpu, &rq->csd); | |
632 | } | |
633 | } | |
634 | ||
635 | static void blk_mq_raise_softirq(struct request *rq) | |
636 | { | |
637 | struct llist_head *list; | |
638 | ||
639 | preempt_disable(); | |
640 | list = this_cpu_ptr(&blk_cpu_done); | |
641 | if (llist_add(&rq->ipi_list, list)) | |
642 | raise_softirq(BLOCK_SOFTIRQ); | |
643 | preempt_enable(); | |
644 | } | |
645 | ||
40d09b53 | 646 | bool blk_mq_complete_request_remote(struct request *rq) |
320ae51f | 647 | { |
af78ff7c | 648 | WRITE_ONCE(rq->state, MQ_RQ_COMPLETE); |
36e76539 | 649 | |
4ab32bf3 JA |
650 | /* |
651 | * For a polled request, always complete locallly, it's pointless | |
652 | * to redirect the completion. | |
653 | */ | |
40d09b53 CH |
654 | if (rq->cmd_flags & REQ_HIPRI) |
655 | return false; | |
38535201 | 656 | |
96339526 | 657 | if (blk_mq_complete_need_ipi(rq)) { |
f9ab4918 SAS |
658 | blk_mq_complete_send_ipi(rq); |
659 | return true; | |
3d6efbf6 | 660 | } |
40d09b53 | 661 | |
f9ab4918 SAS |
662 | if (rq->q->nr_hw_queues == 1) { |
663 | blk_mq_raise_softirq(rq); | |
664 | return true; | |
665 | } | |
666 | return false; | |
40d09b53 CH |
667 | } |
668 | EXPORT_SYMBOL_GPL(blk_mq_complete_request_remote); | |
669 | ||
670 | /** | |
671 | * blk_mq_complete_request - end I/O on a request | |
672 | * @rq: the request being processed | |
673 | * | |
674 | * Description: | |
675 | * Complete a request by scheduling the ->complete_rq operation. | |
676 | **/ | |
677 | void blk_mq_complete_request(struct request *rq) | |
678 | { | |
679 | if (!blk_mq_complete_request_remote(rq)) | |
680 | rq->q->mq_ops->complete(rq); | |
320ae51f | 681 | } |
15f73f5b | 682 | EXPORT_SYMBOL(blk_mq_complete_request); |
30a91cb4 | 683 | |
04ced159 | 684 | static void hctx_unlock(struct blk_mq_hw_ctx *hctx, int srcu_idx) |
b7435db8 | 685 | __releases(hctx->srcu) |
04ced159 JA |
686 | { |
687 | if (!(hctx->flags & BLK_MQ_F_BLOCKING)) | |
688 | rcu_read_unlock(); | |
689 | else | |
05707b64 | 690 | srcu_read_unlock(hctx->srcu, srcu_idx); |
04ced159 JA |
691 | } |
692 | ||
693 | static void hctx_lock(struct blk_mq_hw_ctx *hctx, int *srcu_idx) | |
b7435db8 | 694 | __acquires(hctx->srcu) |
04ced159 | 695 | { |
08b5a6e2 JA |
696 | if (!(hctx->flags & BLK_MQ_F_BLOCKING)) { |
697 | /* shut up gcc false positive */ | |
698 | *srcu_idx = 0; | |
04ced159 | 699 | rcu_read_lock(); |
08b5a6e2 | 700 | } else |
05707b64 | 701 | *srcu_idx = srcu_read_lock(hctx->srcu); |
04ced159 JA |
702 | } |
703 | ||
105663f7 AA |
704 | /** |
705 | * blk_mq_start_request - Start processing a request | |
706 | * @rq: Pointer to request to be started | |
707 | * | |
708 | * Function used by device drivers to notify the block layer that a request | |
709 | * is going to be processed now, so blk layer can do proper initializations | |
710 | * such as starting the timeout timer. | |
711 | */ | |
e2490073 | 712 | void blk_mq_start_request(struct request *rq) |
320ae51f JA |
713 | { |
714 | struct request_queue *q = rq->q; | |
715 | ||
a54895fa | 716 | trace_block_rq_issue(rq); |
320ae51f | 717 | |
cf43e6be | 718 | if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags)) { |
544ccc8d | 719 | rq->io_start_time_ns = ktime_get_ns(); |
3d244306 | 720 | rq->stats_sectors = blk_rq_sectors(rq); |
cf43e6be | 721 | rq->rq_flags |= RQF_STATS; |
a7905043 | 722 | rq_qos_issue(q, rq); |
cf43e6be JA |
723 | } |
724 | ||
1d9bd516 | 725 | WARN_ON_ONCE(blk_mq_rq_state(rq) != MQ_RQ_IDLE); |
538b7534 | 726 | |
1d9bd516 | 727 | blk_add_timer(rq); |
12f5b931 | 728 | WRITE_ONCE(rq->state, MQ_RQ_IN_FLIGHT); |
49f5baa5 | 729 | |
54d4e6ab MG |
730 | #ifdef CONFIG_BLK_DEV_INTEGRITY |
731 | if (blk_integrity_rq(rq) && req_op(rq) == REQ_OP_WRITE) | |
732 | q->integrity.profile->prepare_fn(rq); | |
733 | #endif | |
320ae51f | 734 | } |
e2490073 | 735 | EXPORT_SYMBOL(blk_mq_start_request); |
320ae51f | 736 | |
ed0791b2 | 737 | static void __blk_mq_requeue_request(struct request *rq) |
320ae51f JA |
738 | { |
739 | struct request_queue *q = rq->q; | |
740 | ||
923218f6 ML |
741 | blk_mq_put_driver_tag(rq); |
742 | ||
a54895fa | 743 | trace_block_rq_requeue(rq); |
a7905043 | 744 | rq_qos_requeue(q, rq); |
49f5baa5 | 745 | |
12f5b931 KB |
746 | if (blk_mq_request_started(rq)) { |
747 | WRITE_ONCE(rq->state, MQ_RQ_IDLE); | |
da661267 | 748 | rq->rq_flags &= ~RQF_TIMED_OUT; |
e2490073 | 749 | } |
320ae51f JA |
750 | } |
751 | ||
2b053aca | 752 | void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list) |
ed0791b2 | 753 | { |
ed0791b2 | 754 | __blk_mq_requeue_request(rq); |
ed0791b2 | 755 | |
105976f5 ML |
756 | /* this request will be re-inserted to io scheduler queue */ |
757 | blk_mq_sched_requeue_request(rq); | |
758 | ||
7d692330 | 759 | BUG_ON(!list_empty(&rq->queuelist)); |
2b053aca | 760 | blk_mq_add_to_requeue_list(rq, true, kick_requeue_list); |
ed0791b2 CH |
761 | } |
762 | EXPORT_SYMBOL(blk_mq_requeue_request); | |
763 | ||
6fca6a61 CH |
764 | static void blk_mq_requeue_work(struct work_struct *work) |
765 | { | |
766 | struct request_queue *q = | |
2849450a | 767 | container_of(work, struct request_queue, requeue_work.work); |
6fca6a61 CH |
768 | LIST_HEAD(rq_list); |
769 | struct request *rq, *next; | |
6fca6a61 | 770 | |
18e9781d | 771 | spin_lock_irq(&q->requeue_lock); |
6fca6a61 | 772 | list_splice_init(&q->requeue_list, &rq_list); |
18e9781d | 773 | spin_unlock_irq(&q->requeue_lock); |
6fca6a61 CH |
774 | |
775 | list_for_each_entry_safe(rq, next, &rq_list, queuelist) { | |
aef1897c | 776 | if (!(rq->rq_flags & (RQF_SOFTBARRIER | RQF_DONTPREP))) |
6fca6a61 CH |
777 | continue; |
778 | ||
e8064021 | 779 | rq->rq_flags &= ~RQF_SOFTBARRIER; |
6fca6a61 | 780 | list_del_init(&rq->queuelist); |
aef1897c JW |
781 | /* |
782 | * If RQF_DONTPREP, rq has contained some driver specific | |
783 | * data, so insert it to hctx dispatch list to avoid any | |
784 | * merge. | |
785 | */ | |
786 | if (rq->rq_flags & RQF_DONTPREP) | |
01e99aec | 787 | blk_mq_request_bypass_insert(rq, false, false); |
aef1897c JW |
788 | else |
789 | blk_mq_sched_insert_request(rq, true, false, false); | |
6fca6a61 CH |
790 | } |
791 | ||
792 | while (!list_empty(&rq_list)) { | |
793 | rq = list_entry(rq_list.next, struct request, queuelist); | |
794 | list_del_init(&rq->queuelist); | |
9e97d295 | 795 | blk_mq_sched_insert_request(rq, false, false, false); |
6fca6a61 CH |
796 | } |
797 | ||
52d7f1b5 | 798 | blk_mq_run_hw_queues(q, false); |
6fca6a61 CH |
799 | } |
800 | ||
2b053aca BVA |
801 | void blk_mq_add_to_requeue_list(struct request *rq, bool at_head, |
802 | bool kick_requeue_list) | |
6fca6a61 CH |
803 | { |
804 | struct request_queue *q = rq->q; | |
805 | unsigned long flags; | |
806 | ||
807 | /* | |
808 | * We abuse this flag that is otherwise used by the I/O scheduler to | |
ff821d27 | 809 | * request head insertion from the workqueue. |
6fca6a61 | 810 | */ |
e8064021 | 811 | BUG_ON(rq->rq_flags & RQF_SOFTBARRIER); |
6fca6a61 CH |
812 | |
813 | spin_lock_irqsave(&q->requeue_lock, flags); | |
814 | if (at_head) { | |
e8064021 | 815 | rq->rq_flags |= RQF_SOFTBARRIER; |
6fca6a61 CH |
816 | list_add(&rq->queuelist, &q->requeue_list); |
817 | } else { | |
818 | list_add_tail(&rq->queuelist, &q->requeue_list); | |
819 | } | |
820 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
2b053aca BVA |
821 | |
822 | if (kick_requeue_list) | |
823 | blk_mq_kick_requeue_list(q); | |
6fca6a61 | 824 | } |
6fca6a61 CH |
825 | |
826 | void blk_mq_kick_requeue_list(struct request_queue *q) | |
827 | { | |
ae943d20 | 828 | kblockd_mod_delayed_work_on(WORK_CPU_UNBOUND, &q->requeue_work, 0); |
6fca6a61 CH |
829 | } |
830 | EXPORT_SYMBOL(blk_mq_kick_requeue_list); | |
831 | ||
2849450a MS |
832 | void blk_mq_delay_kick_requeue_list(struct request_queue *q, |
833 | unsigned long msecs) | |
834 | { | |
d4acf365 BVA |
835 | kblockd_mod_delayed_work_on(WORK_CPU_UNBOUND, &q->requeue_work, |
836 | msecs_to_jiffies(msecs)); | |
2849450a MS |
837 | } |
838 | EXPORT_SYMBOL(blk_mq_delay_kick_requeue_list); | |
839 | ||
0e62f51f JA |
840 | struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag) |
841 | { | |
88c7b2b7 JA |
842 | if (tag < tags->nr_tags) { |
843 | prefetch(tags->rqs[tag]); | |
4ee86bab | 844 | return tags->rqs[tag]; |
88c7b2b7 | 845 | } |
4ee86bab HR |
846 | |
847 | return NULL; | |
24d2f903 CH |
848 | } |
849 | EXPORT_SYMBOL(blk_mq_tag_to_rq); | |
850 | ||
3c94d83c JA |
851 | static bool blk_mq_rq_inflight(struct blk_mq_hw_ctx *hctx, struct request *rq, |
852 | void *priv, bool reserved) | |
ae879912 JA |
853 | { |
854 | /* | |
05a4fed6 | 855 | * If we find a request that isn't idle and the queue matches, |
3c94d83c | 856 | * we know the queue is busy. Return false to stop the iteration. |
ae879912 | 857 | */ |
05a4fed6 | 858 | if (blk_mq_request_started(rq) && rq->q == hctx->queue) { |
ae879912 JA |
859 | bool *busy = priv; |
860 | ||
861 | *busy = true; | |
862 | return false; | |
863 | } | |
864 | ||
865 | return true; | |
866 | } | |
867 | ||
3c94d83c | 868 | bool blk_mq_queue_inflight(struct request_queue *q) |
ae879912 JA |
869 | { |
870 | bool busy = false; | |
871 | ||
3c94d83c | 872 | blk_mq_queue_tag_busy_iter(q, blk_mq_rq_inflight, &busy); |
ae879912 JA |
873 | return busy; |
874 | } | |
3c94d83c | 875 | EXPORT_SYMBOL_GPL(blk_mq_queue_inflight); |
ae879912 | 876 | |
358f70da | 877 | static void blk_mq_rq_timed_out(struct request *req, bool reserved) |
320ae51f | 878 | { |
da661267 | 879 | req->rq_flags |= RQF_TIMED_OUT; |
d1210d5a CH |
880 | if (req->q->mq_ops->timeout) { |
881 | enum blk_eh_timer_return ret; | |
882 | ||
883 | ret = req->q->mq_ops->timeout(req, reserved); | |
884 | if (ret == BLK_EH_DONE) | |
885 | return; | |
886 | WARN_ON_ONCE(ret != BLK_EH_RESET_TIMER); | |
46f92d42 | 887 | } |
d1210d5a CH |
888 | |
889 | blk_add_timer(req); | |
87ee7b11 | 890 | } |
5b3f25fc | 891 | |
12f5b931 | 892 | static bool blk_mq_req_expired(struct request *rq, unsigned long *next) |
81481eb4 | 893 | { |
12f5b931 | 894 | unsigned long deadline; |
87ee7b11 | 895 | |
12f5b931 KB |
896 | if (blk_mq_rq_state(rq) != MQ_RQ_IN_FLIGHT) |
897 | return false; | |
da661267 CH |
898 | if (rq->rq_flags & RQF_TIMED_OUT) |
899 | return false; | |
a7af0af3 | 900 | |
079076b3 | 901 | deadline = READ_ONCE(rq->deadline); |
12f5b931 KB |
902 | if (time_after_eq(jiffies, deadline)) |
903 | return true; | |
a7af0af3 | 904 | |
12f5b931 KB |
905 | if (*next == 0) |
906 | *next = deadline; | |
907 | else if (time_after(*next, deadline)) | |
908 | *next = deadline; | |
909 | return false; | |
87ee7b11 JA |
910 | } |
911 | ||
2e315dc0 ML |
912 | void blk_mq_put_rq_ref(struct request *rq) |
913 | { | |
914 | if (is_flush_rq(rq, rq->mq_hctx)) | |
915 | rq->end_io(rq, 0); | |
916 | else if (refcount_dec_and_test(&rq->ref)) | |
917 | __blk_mq_free_request(rq); | |
918 | } | |
919 | ||
7baa8572 | 920 | static bool blk_mq_check_expired(struct blk_mq_hw_ctx *hctx, |
1d9bd516 TH |
921 | struct request *rq, void *priv, bool reserved) |
922 | { | |
12f5b931 KB |
923 | unsigned long *next = priv; |
924 | ||
925 | /* | |
926 | * Just do a quick check if it is expired before locking the request in | |
927 | * so we're not unnecessarilly synchronizing across CPUs. | |
928 | */ | |
929 | if (!blk_mq_req_expired(rq, next)) | |
7baa8572 | 930 | return true; |
12f5b931 KB |
931 | |
932 | /* | |
933 | * We have reason to believe the request may be expired. Take a | |
934 | * reference on the request to lock this request lifetime into its | |
935 | * currently allocated context to prevent it from being reallocated in | |
936 | * the event the completion by-passes this timeout handler. | |
937 | * | |
938 | * If the reference was already released, then the driver beat the | |
939 | * timeout handler to posting a natural completion. | |
940 | */ | |
941 | if (!refcount_inc_not_zero(&rq->ref)) | |
7baa8572 | 942 | return true; |
12f5b931 | 943 | |
1d9bd516 | 944 | /* |
12f5b931 KB |
945 | * The request is now locked and cannot be reallocated underneath the |
946 | * timeout handler's processing. Re-verify this exact request is truly | |
947 | * expired; if it is not expired, then the request was completed and | |
948 | * reallocated as a new request. | |
1d9bd516 | 949 | */ |
12f5b931 | 950 | if (blk_mq_req_expired(rq, next)) |
1d9bd516 | 951 | blk_mq_rq_timed_out(rq, reserved); |
8d699663 | 952 | |
2e315dc0 | 953 | blk_mq_put_rq_ref(rq); |
7baa8572 | 954 | return true; |
1d9bd516 TH |
955 | } |
956 | ||
287922eb | 957 | static void blk_mq_timeout_work(struct work_struct *work) |
320ae51f | 958 | { |
287922eb CH |
959 | struct request_queue *q = |
960 | container_of(work, struct request_queue, timeout_work); | |
12f5b931 | 961 | unsigned long next = 0; |
1d9bd516 | 962 | struct blk_mq_hw_ctx *hctx; |
81481eb4 | 963 | int i; |
320ae51f | 964 | |
71f79fb3 GKB |
965 | /* A deadlock might occur if a request is stuck requiring a |
966 | * timeout at the same time a queue freeze is waiting | |
967 | * completion, since the timeout code would not be able to | |
968 | * acquire the queue reference here. | |
969 | * | |
970 | * That's why we don't use blk_queue_enter here; instead, we use | |
971 | * percpu_ref_tryget directly, because we need to be able to | |
972 | * obtain a reference even in the short window between the queue | |
973 | * starting to freeze, by dropping the first reference in | |
1671d522 | 974 | * blk_freeze_queue_start, and the moment the last request is |
71f79fb3 GKB |
975 | * consumed, marked by the instant q_usage_counter reaches |
976 | * zero. | |
977 | */ | |
978 | if (!percpu_ref_tryget(&q->q_usage_counter)) | |
287922eb CH |
979 | return; |
980 | ||
12f5b931 | 981 | blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &next); |
320ae51f | 982 | |
12f5b931 KB |
983 | if (next != 0) { |
984 | mod_timer(&q->timeout, next); | |
0d2602ca | 985 | } else { |
fcd36c36 BVA |
986 | /* |
987 | * Request timeouts are handled as a forward rolling timer. If | |
988 | * we end up here it means that no requests are pending and | |
989 | * also that no request has been pending for a while. Mark | |
990 | * each hctx as idle. | |
991 | */ | |
f054b56c ML |
992 | queue_for_each_hw_ctx(q, hctx, i) { |
993 | /* the hctx may be unmapped, so check it here */ | |
994 | if (blk_mq_hw_queue_mapped(hctx)) | |
995 | blk_mq_tag_idle(hctx); | |
996 | } | |
0d2602ca | 997 | } |
287922eb | 998 | blk_queue_exit(q); |
320ae51f JA |
999 | } |
1000 | ||
88459642 OS |
1001 | struct flush_busy_ctx_data { |
1002 | struct blk_mq_hw_ctx *hctx; | |
1003 | struct list_head *list; | |
1004 | }; | |
1005 | ||
1006 | static bool flush_busy_ctx(struct sbitmap *sb, unsigned int bitnr, void *data) | |
1007 | { | |
1008 | struct flush_busy_ctx_data *flush_data = data; | |
1009 | struct blk_mq_hw_ctx *hctx = flush_data->hctx; | |
1010 | struct blk_mq_ctx *ctx = hctx->ctxs[bitnr]; | |
c16d6b5a | 1011 | enum hctx_type type = hctx->type; |
88459642 | 1012 | |
88459642 | 1013 | spin_lock(&ctx->lock); |
c16d6b5a | 1014 | list_splice_tail_init(&ctx->rq_lists[type], flush_data->list); |
e9a99a63 | 1015 | sbitmap_clear_bit(sb, bitnr); |
88459642 OS |
1016 | spin_unlock(&ctx->lock); |
1017 | return true; | |
1018 | } | |
1019 | ||
1429d7c9 JA |
1020 | /* |
1021 | * Process software queues that have been marked busy, splicing them | |
1022 | * to the for-dispatch | |
1023 | */ | |
2c3ad667 | 1024 | void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) |
1429d7c9 | 1025 | { |
88459642 OS |
1026 | struct flush_busy_ctx_data data = { |
1027 | .hctx = hctx, | |
1028 | .list = list, | |
1029 | }; | |
1429d7c9 | 1030 | |
88459642 | 1031 | sbitmap_for_each_set(&hctx->ctx_map, flush_busy_ctx, &data); |
1429d7c9 | 1032 | } |
2c3ad667 | 1033 | EXPORT_SYMBOL_GPL(blk_mq_flush_busy_ctxs); |
1429d7c9 | 1034 | |
b347689f ML |
1035 | struct dispatch_rq_data { |
1036 | struct blk_mq_hw_ctx *hctx; | |
1037 | struct request *rq; | |
1038 | }; | |
1039 | ||
1040 | static bool dispatch_rq_from_ctx(struct sbitmap *sb, unsigned int bitnr, | |
1041 | void *data) | |
1042 | { | |
1043 | struct dispatch_rq_data *dispatch_data = data; | |
1044 | struct blk_mq_hw_ctx *hctx = dispatch_data->hctx; | |
1045 | struct blk_mq_ctx *ctx = hctx->ctxs[bitnr]; | |
c16d6b5a | 1046 | enum hctx_type type = hctx->type; |
b347689f ML |
1047 | |
1048 | spin_lock(&ctx->lock); | |
c16d6b5a ML |
1049 | if (!list_empty(&ctx->rq_lists[type])) { |
1050 | dispatch_data->rq = list_entry_rq(ctx->rq_lists[type].next); | |
b347689f | 1051 | list_del_init(&dispatch_data->rq->queuelist); |
c16d6b5a | 1052 | if (list_empty(&ctx->rq_lists[type])) |
b347689f ML |
1053 | sbitmap_clear_bit(sb, bitnr); |
1054 | } | |
1055 | spin_unlock(&ctx->lock); | |
1056 | ||
1057 | return !dispatch_data->rq; | |
1058 | } | |
1059 | ||
1060 | struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx, | |
1061 | struct blk_mq_ctx *start) | |
1062 | { | |
f31967f0 | 1063 | unsigned off = start ? start->index_hw[hctx->type] : 0; |
b347689f ML |
1064 | struct dispatch_rq_data data = { |
1065 | .hctx = hctx, | |
1066 | .rq = NULL, | |
1067 | }; | |
1068 | ||
1069 | __sbitmap_for_each_set(&hctx->ctx_map, off, | |
1070 | dispatch_rq_from_ctx, &data); | |
1071 | ||
1072 | return data.rq; | |
1073 | } | |
1074 | ||
703fd1c0 JA |
1075 | static inline unsigned int queued_to_index(unsigned int queued) |
1076 | { | |
1077 | if (!queued) | |
1078 | return 0; | |
1429d7c9 | 1079 | |
703fd1c0 | 1080 | return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1); |
1429d7c9 JA |
1081 | } |
1082 | ||
570e9b73 ML |
1083 | static bool __blk_mq_get_driver_tag(struct request *rq) |
1084 | { | |
222a5ae0 | 1085 | struct sbitmap_queue *bt = rq->mq_hctx->tags->bitmap_tags; |
570e9b73 | 1086 | unsigned int tag_offset = rq->mq_hctx->tags->nr_reserved_tags; |
570e9b73 ML |
1087 | int tag; |
1088 | ||
568f2700 ML |
1089 | blk_mq_tag_busy(rq->mq_hctx); |
1090 | ||
570e9b73 | 1091 | if (blk_mq_tag_is_reserved(rq->mq_hctx->sched_tags, rq->internal_tag)) { |
222a5ae0 | 1092 | bt = rq->mq_hctx->tags->breserved_tags; |
570e9b73 | 1093 | tag_offset = 0; |
28500850 ML |
1094 | } else { |
1095 | if (!hctx_may_queue(rq->mq_hctx, bt)) | |
1096 | return false; | |
570e9b73 ML |
1097 | } |
1098 | ||
570e9b73 ML |
1099 | tag = __sbitmap_queue_get(bt); |
1100 | if (tag == BLK_MQ_NO_TAG) | |
1101 | return false; | |
1102 | ||
1103 | rq->tag = tag + tag_offset; | |
570e9b73 ML |
1104 | return true; |
1105 | } | |
1106 | ||
1107 | static bool blk_mq_get_driver_tag(struct request *rq) | |
1108 | { | |
568f2700 ML |
1109 | struct blk_mq_hw_ctx *hctx = rq->mq_hctx; |
1110 | ||
1111 | if (rq->tag == BLK_MQ_NO_TAG && !__blk_mq_get_driver_tag(rq)) | |
1112 | return false; | |
1113 | ||
51db1c37 | 1114 | if ((hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) && |
568f2700 ML |
1115 | !(rq->rq_flags & RQF_MQ_INFLIGHT)) { |
1116 | rq->rq_flags |= RQF_MQ_INFLIGHT; | |
bccf5e26 | 1117 | __blk_mq_inc_active_requests(hctx); |
568f2700 ML |
1118 | } |
1119 | hctx->tags->rqs[rq->tag] = rq; | |
1120 | return true; | |
570e9b73 ML |
1121 | } |
1122 | ||
eb619fdb JA |
1123 | static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode, |
1124 | int flags, void *key) | |
da55f2cc OS |
1125 | { |
1126 | struct blk_mq_hw_ctx *hctx; | |
1127 | ||
1128 | hctx = container_of(wait, struct blk_mq_hw_ctx, dispatch_wait); | |
1129 | ||
5815839b | 1130 | spin_lock(&hctx->dispatch_wait_lock); |
e8618575 JA |
1131 | if (!list_empty(&wait->entry)) { |
1132 | struct sbitmap_queue *sbq; | |
1133 | ||
1134 | list_del_init(&wait->entry); | |
222a5ae0 | 1135 | sbq = hctx->tags->bitmap_tags; |
e8618575 JA |
1136 | atomic_dec(&sbq->ws_active); |
1137 | } | |
5815839b ML |
1138 | spin_unlock(&hctx->dispatch_wait_lock); |
1139 | ||
da55f2cc OS |
1140 | blk_mq_run_hw_queue(hctx, true); |
1141 | return 1; | |
1142 | } | |
1143 | ||
f906a6a0 JA |
1144 | /* |
1145 | * Mark us waiting for a tag. For shared tags, this involves hooking us into | |
ee3e4de5 BVA |
1146 | * the tag wakeups. For non-shared tags, we can simply mark us needing a |
1147 | * restart. For both cases, take care to check the condition again after | |
f906a6a0 JA |
1148 | * marking us as waiting. |
1149 | */ | |
2278d69f | 1150 | static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx *hctx, |
f906a6a0 | 1151 | struct request *rq) |
da55f2cc | 1152 | { |
222a5ae0 | 1153 | struct sbitmap_queue *sbq = hctx->tags->bitmap_tags; |
5815839b | 1154 | struct wait_queue_head *wq; |
f906a6a0 JA |
1155 | wait_queue_entry_t *wait; |
1156 | bool ret; | |
da55f2cc | 1157 | |
51db1c37 | 1158 | if (!(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) { |
684b7324 | 1159 | blk_mq_sched_mark_restart_hctx(hctx); |
f906a6a0 | 1160 | |
c27d53fb BVA |
1161 | /* |
1162 | * It's possible that a tag was freed in the window between the | |
1163 | * allocation failure and adding the hardware queue to the wait | |
1164 | * queue. | |
1165 | * | |
1166 | * Don't clear RESTART here, someone else could have set it. | |
1167 | * At most this will cost an extra queue run. | |
1168 | */ | |
8ab6bb9e | 1169 | return blk_mq_get_driver_tag(rq); |
eb619fdb | 1170 | } |
eb619fdb | 1171 | |
2278d69f | 1172 | wait = &hctx->dispatch_wait; |
c27d53fb BVA |
1173 | if (!list_empty_careful(&wait->entry)) |
1174 | return false; | |
1175 | ||
e8618575 | 1176 | wq = &bt_wait_ptr(sbq, hctx)->wait; |
5815839b ML |
1177 | |
1178 | spin_lock_irq(&wq->lock); | |
1179 | spin_lock(&hctx->dispatch_wait_lock); | |
c27d53fb | 1180 | if (!list_empty(&wait->entry)) { |
5815839b ML |
1181 | spin_unlock(&hctx->dispatch_wait_lock); |
1182 | spin_unlock_irq(&wq->lock); | |
c27d53fb | 1183 | return false; |
eb619fdb JA |
1184 | } |
1185 | ||
e8618575 | 1186 | atomic_inc(&sbq->ws_active); |
5815839b ML |
1187 | wait->flags &= ~WQ_FLAG_EXCLUSIVE; |
1188 | __add_wait_queue(wq, wait); | |
c27d53fb | 1189 | |
da55f2cc | 1190 | /* |
eb619fdb JA |
1191 | * It's possible that a tag was freed in the window between the |
1192 | * allocation failure and adding the hardware queue to the wait | |
1193 | * queue. | |
da55f2cc | 1194 | */ |
8ab6bb9e | 1195 | ret = blk_mq_get_driver_tag(rq); |
c27d53fb | 1196 | if (!ret) { |
5815839b ML |
1197 | spin_unlock(&hctx->dispatch_wait_lock); |
1198 | spin_unlock_irq(&wq->lock); | |
c27d53fb | 1199 | return false; |
eb619fdb | 1200 | } |
c27d53fb BVA |
1201 | |
1202 | /* | |
1203 | * We got a tag, remove ourselves from the wait queue to ensure | |
1204 | * someone else gets the wakeup. | |
1205 | */ | |
c27d53fb | 1206 | list_del_init(&wait->entry); |
e8618575 | 1207 | atomic_dec(&sbq->ws_active); |
5815839b ML |
1208 | spin_unlock(&hctx->dispatch_wait_lock); |
1209 | spin_unlock_irq(&wq->lock); | |
c27d53fb BVA |
1210 | |
1211 | return true; | |
da55f2cc OS |
1212 | } |
1213 | ||
6e768717 ML |
1214 | #define BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT 8 |
1215 | #define BLK_MQ_DISPATCH_BUSY_EWMA_FACTOR 4 | |
1216 | /* | |
1217 | * Update dispatch busy with the Exponential Weighted Moving Average(EWMA): | |
1218 | * - EWMA is one simple way to compute running average value | |
1219 | * - weight(7/8 and 1/8) is applied so that it can decrease exponentially | |
1220 | * - take 4 as factor for avoiding to get too small(0) result, and this | |
1221 | * factor doesn't matter because EWMA decreases exponentially | |
1222 | */ | |
1223 | static void blk_mq_update_dispatch_busy(struct blk_mq_hw_ctx *hctx, bool busy) | |
1224 | { | |
1225 | unsigned int ewma; | |
1226 | ||
1227 | if (hctx->queue->elevator) | |
1228 | return; | |
1229 | ||
1230 | ewma = hctx->dispatch_busy; | |
1231 | ||
1232 | if (!ewma && !busy) | |
1233 | return; | |
1234 | ||
1235 | ewma *= BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT - 1; | |
1236 | if (busy) | |
1237 | ewma += 1 << BLK_MQ_DISPATCH_BUSY_EWMA_FACTOR; | |
1238 | ewma /= BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT; | |
1239 | ||
1240 | hctx->dispatch_busy = ewma; | |
1241 | } | |
1242 | ||
86ff7c2a ML |
1243 | #define BLK_MQ_RESOURCE_DELAY 3 /* ms units */ |
1244 | ||
c92a4103 JT |
1245 | static void blk_mq_handle_dev_resource(struct request *rq, |
1246 | struct list_head *list) | |
1247 | { | |
1248 | struct request *next = | |
1249 | list_first_entry_or_null(list, struct request, queuelist); | |
1250 | ||
1251 | /* | |
1252 | * If an I/O scheduler has been configured and we got a driver tag for | |
1253 | * the next request already, free it. | |
1254 | */ | |
1255 | if (next) | |
1256 | blk_mq_put_driver_tag(next); | |
1257 | ||
1258 | list_add(&rq->queuelist, list); | |
1259 | __blk_mq_requeue_request(rq); | |
1260 | } | |
1261 | ||
0512a75b KB |
1262 | static void blk_mq_handle_zone_resource(struct request *rq, |
1263 | struct list_head *zone_list) | |
1264 | { | |
1265 | /* | |
1266 | * If we end up here it is because we cannot dispatch a request to a | |
1267 | * specific zone due to LLD level zone-write locking or other zone | |
1268 | * related resource not being available. In this case, set the request | |
1269 | * aside in zone_list for retrying it later. | |
1270 | */ | |
1271 | list_add(&rq->queuelist, zone_list); | |
1272 | __blk_mq_requeue_request(rq); | |
1273 | } | |
1274 | ||
75383524 ML |
1275 | enum prep_dispatch { |
1276 | PREP_DISPATCH_OK, | |
1277 | PREP_DISPATCH_NO_TAG, | |
1278 | PREP_DISPATCH_NO_BUDGET, | |
1279 | }; | |
1280 | ||
1281 | static enum prep_dispatch blk_mq_prep_dispatch_rq(struct request *rq, | |
1282 | bool need_budget) | |
1283 | { | |
1284 | struct blk_mq_hw_ctx *hctx = rq->mq_hctx; | |
2a5a24aa | 1285 | int budget_token = -1; |
75383524 | 1286 | |
2a5a24aa ML |
1287 | if (need_budget) { |
1288 | budget_token = blk_mq_get_dispatch_budget(rq->q); | |
1289 | if (budget_token < 0) { | |
1290 | blk_mq_put_driver_tag(rq); | |
1291 | return PREP_DISPATCH_NO_BUDGET; | |
1292 | } | |
1293 | blk_mq_set_rq_budget_token(rq, budget_token); | |
75383524 ML |
1294 | } |
1295 | ||
1296 | if (!blk_mq_get_driver_tag(rq)) { | |
1297 | /* | |
1298 | * The initial allocation attempt failed, so we need to | |
1299 | * rerun the hardware queue when a tag is freed. The | |
1300 | * waitqueue takes care of that. If the queue is run | |
1301 | * before we add this entry back on the dispatch list, | |
1302 | * we'll re-run it below. | |
1303 | */ | |
1304 | if (!blk_mq_mark_tag_wait(hctx, rq)) { | |
1fd40b5e ML |
1305 | /* |
1306 | * All budgets not got from this function will be put | |
1307 | * together during handling partial dispatch | |
1308 | */ | |
1309 | if (need_budget) | |
2a5a24aa | 1310 | blk_mq_put_dispatch_budget(rq->q, budget_token); |
75383524 ML |
1311 | return PREP_DISPATCH_NO_TAG; |
1312 | } | |
1313 | } | |
1314 | ||
1315 | return PREP_DISPATCH_OK; | |
1316 | } | |
1317 | ||
1fd40b5e ML |
1318 | /* release all allocated budgets before calling to blk_mq_dispatch_rq_list */ |
1319 | static void blk_mq_release_budgets(struct request_queue *q, | |
2a5a24aa | 1320 | struct list_head *list) |
1fd40b5e | 1321 | { |
2a5a24aa | 1322 | struct request *rq; |
1fd40b5e | 1323 | |
2a5a24aa ML |
1324 | list_for_each_entry(rq, list, queuelist) { |
1325 | int budget_token = blk_mq_get_rq_budget_token(rq); | |
1fd40b5e | 1326 | |
2a5a24aa ML |
1327 | if (budget_token >= 0) |
1328 | blk_mq_put_dispatch_budget(q, budget_token); | |
1329 | } | |
1fd40b5e ML |
1330 | } |
1331 | ||
1f57f8d4 JA |
1332 | /* |
1333 | * Returns true if we did some work AND can potentially do more. | |
1334 | */ | |
445874e8 | 1335 | bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list, |
1fd40b5e | 1336 | unsigned int nr_budgets) |
320ae51f | 1337 | { |
75383524 | 1338 | enum prep_dispatch prep; |
445874e8 | 1339 | struct request_queue *q = hctx->queue; |
6d6f167c | 1340 | struct request *rq, *nxt; |
fc17b653 | 1341 | int errors, queued; |
86ff7c2a | 1342 | blk_status_t ret = BLK_STS_OK; |
0512a75b | 1343 | LIST_HEAD(zone_list); |
320ae51f | 1344 | |
81380ca1 OS |
1345 | if (list_empty(list)) |
1346 | return false; | |
1347 | ||
320ae51f JA |
1348 | /* |
1349 | * Now process all the entries, sending them to the driver. | |
1350 | */ | |
93efe981 | 1351 | errors = queued = 0; |
81380ca1 | 1352 | do { |
74c45052 | 1353 | struct blk_mq_queue_data bd; |
320ae51f | 1354 | |
f04c3df3 | 1355 | rq = list_first_entry(list, struct request, queuelist); |
0bca799b | 1356 | |
445874e8 | 1357 | WARN_ON_ONCE(hctx != rq->mq_hctx); |
1fd40b5e | 1358 | prep = blk_mq_prep_dispatch_rq(rq, !nr_budgets); |
75383524 | 1359 | if (prep != PREP_DISPATCH_OK) |
0bca799b | 1360 | break; |
de148297 | 1361 | |
320ae51f | 1362 | list_del_init(&rq->queuelist); |
320ae51f | 1363 | |
74c45052 | 1364 | bd.rq = rq; |
113285b4 JA |
1365 | |
1366 | /* | |
1367 | * Flag last if we have no more requests, or if we have more | |
1368 | * but can't assign a driver tag to it. | |
1369 | */ | |
1370 | if (list_empty(list)) | |
1371 | bd.last = true; | |
1372 | else { | |
113285b4 | 1373 | nxt = list_first_entry(list, struct request, queuelist); |
8ab6bb9e | 1374 | bd.last = !blk_mq_get_driver_tag(nxt); |
113285b4 | 1375 | } |
74c45052 | 1376 | |
1fd40b5e ML |
1377 | /* |
1378 | * once the request is queued to lld, no need to cover the | |
1379 | * budget any more | |
1380 | */ | |
1381 | if (nr_budgets) | |
1382 | nr_budgets--; | |
74c45052 | 1383 | ret = q->mq_ops->queue_rq(hctx, &bd); |
7bf13729 ML |
1384 | switch (ret) { |
1385 | case BLK_STS_OK: | |
1386 | queued++; | |
320ae51f | 1387 | break; |
7bf13729 ML |
1388 | case BLK_STS_RESOURCE: |
1389 | case BLK_STS_DEV_RESOURCE: | |
1390 | blk_mq_handle_dev_resource(rq, list); | |
1391 | goto out; | |
1392 | case BLK_STS_ZONE_RESOURCE: | |
0512a75b KB |
1393 | /* |
1394 | * Move the request to zone_list and keep going through | |
1395 | * the dispatch list to find more requests the drive can | |
1396 | * accept. | |
1397 | */ | |
1398 | blk_mq_handle_zone_resource(rq, &zone_list); | |
7bf13729 ML |
1399 | break; |
1400 | default: | |
93efe981 | 1401 | errors++; |
e21ee5a6 | 1402 | blk_mq_end_request(rq, ret); |
320ae51f | 1403 | } |
81380ca1 | 1404 | } while (!list_empty(list)); |
7bf13729 | 1405 | out: |
0512a75b KB |
1406 | if (!list_empty(&zone_list)) |
1407 | list_splice_tail_init(&zone_list, list); | |
1408 | ||
703fd1c0 | 1409 | hctx->dispatched[queued_to_index(queued)]++; |
320ae51f | 1410 | |
632bfb63 | 1411 | /* If we didn't flush the entire list, we could have told the driver |
1412 | * there was more coming, but that turned out to be a lie. | |
1413 | */ | |
1414 | if ((!list_empty(list) || errors) && q->mq_ops->commit_rqs && queued) | |
1415 | q->mq_ops->commit_rqs(hctx); | |
320ae51f JA |
1416 | /* |
1417 | * Any items that need requeuing? Stuff them into hctx->dispatch, | |
1418 | * that is where we will continue on next queue run. | |
1419 | */ | |
f04c3df3 | 1420 | if (!list_empty(list)) { |
86ff7c2a | 1421 | bool needs_restart; |
75383524 ML |
1422 | /* For non-shared tags, the RESTART check will suffice */ |
1423 | bool no_tag = prep == PREP_DISPATCH_NO_TAG && | |
51db1c37 | 1424 | (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED); |
75383524 | 1425 | bool no_budget_avail = prep == PREP_DISPATCH_NO_BUDGET; |
86ff7c2a | 1426 | |
2a5a24aa ML |
1427 | if (nr_budgets) |
1428 | blk_mq_release_budgets(q, list); | |
86ff7c2a | 1429 | |
320ae51f | 1430 | spin_lock(&hctx->lock); |
01e99aec | 1431 | list_splice_tail_init(list, &hctx->dispatch); |
320ae51f | 1432 | spin_unlock(&hctx->lock); |
f04c3df3 | 1433 | |
d7d8535f ML |
1434 | /* |
1435 | * Order adding requests to hctx->dispatch and checking | |
1436 | * SCHED_RESTART flag. The pair of this smp_mb() is the one | |
1437 | * in blk_mq_sched_restart(). Avoid restart code path to | |
1438 | * miss the new added requests to hctx->dispatch, meantime | |
1439 | * SCHED_RESTART is observed here. | |
1440 | */ | |
1441 | smp_mb(); | |
1442 | ||
9ba52e58 | 1443 | /* |
710c785f BVA |
1444 | * If SCHED_RESTART was set by the caller of this function and |
1445 | * it is no longer set that means that it was cleared by another | |
1446 | * thread and hence that a queue rerun is needed. | |
9ba52e58 | 1447 | * |
eb619fdb JA |
1448 | * If 'no_tag' is set, that means that we failed getting |
1449 | * a driver tag with an I/O scheduler attached. If our dispatch | |
1450 | * waitqueue is no longer active, ensure that we run the queue | |
1451 | * AFTER adding our entries back to the list. | |
bd166ef1 | 1452 | * |
710c785f BVA |
1453 | * If no I/O scheduler has been configured it is possible that |
1454 | * the hardware queue got stopped and restarted before requests | |
1455 | * were pushed back onto the dispatch list. Rerun the queue to | |
1456 | * avoid starvation. Notes: | |
1457 | * - blk_mq_run_hw_queue() checks whether or not a queue has | |
1458 | * been stopped before rerunning a queue. | |
1459 | * - Some but not all block drivers stop a queue before | |
fc17b653 | 1460 | * returning BLK_STS_RESOURCE. Two exceptions are scsi-mq |
710c785f | 1461 | * and dm-rq. |
86ff7c2a ML |
1462 | * |
1463 | * If driver returns BLK_STS_RESOURCE and SCHED_RESTART | |
1464 | * bit is set, run queue after a delay to avoid IO stalls | |
ab3cee37 DA |
1465 | * that could otherwise occur if the queue is idle. We'll do |
1466 | * similar if we couldn't get budget and SCHED_RESTART is set. | |
bd166ef1 | 1467 | */ |
86ff7c2a ML |
1468 | needs_restart = blk_mq_sched_needs_restart(hctx); |
1469 | if (!needs_restart || | |
eb619fdb | 1470 | (no_tag && list_empty_careful(&hctx->dispatch_wait.entry))) |
bd166ef1 | 1471 | blk_mq_run_hw_queue(hctx, true); |
ab3cee37 DA |
1472 | else if (needs_restart && (ret == BLK_STS_RESOURCE || |
1473 | no_budget_avail)) | |
86ff7c2a | 1474 | blk_mq_delay_run_hw_queue(hctx, BLK_MQ_RESOURCE_DELAY); |
1f57f8d4 | 1475 | |
6e768717 | 1476 | blk_mq_update_dispatch_busy(hctx, true); |
1f57f8d4 | 1477 | return false; |
6e768717 ML |
1478 | } else |
1479 | blk_mq_update_dispatch_busy(hctx, false); | |
f04c3df3 | 1480 | |
93efe981 | 1481 | return (queued + errors) != 0; |
f04c3df3 JA |
1482 | } |
1483 | ||
105663f7 AA |
1484 | /** |
1485 | * __blk_mq_run_hw_queue - Run a hardware queue. | |
1486 | * @hctx: Pointer to the hardware queue to run. | |
1487 | * | |
1488 | * Send pending requests to the hardware. | |
1489 | */ | |
6a83e74d BVA |
1490 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) |
1491 | { | |
1492 | int srcu_idx; | |
1493 | ||
b7a71e66 JA |
1494 | /* |
1495 | * We can't run the queue inline with ints disabled. Ensure that | |
1496 | * we catch bad users of this early. | |
1497 | */ | |
1498 | WARN_ON_ONCE(in_interrupt()); | |
1499 | ||
04ced159 | 1500 | might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING); |
bf4907c0 | 1501 | |
04ced159 JA |
1502 | hctx_lock(hctx, &srcu_idx); |
1503 | blk_mq_sched_dispatch_requests(hctx); | |
1504 | hctx_unlock(hctx, srcu_idx); | |
6a83e74d BVA |
1505 | } |
1506 | ||
f82ddf19 ML |
1507 | static inline int blk_mq_first_mapped_cpu(struct blk_mq_hw_ctx *hctx) |
1508 | { | |
1509 | int cpu = cpumask_first_and(hctx->cpumask, cpu_online_mask); | |
1510 | ||
1511 | if (cpu >= nr_cpu_ids) | |
1512 | cpu = cpumask_first(hctx->cpumask); | |
1513 | return cpu; | |
1514 | } | |
1515 | ||
506e931f JA |
1516 | /* |
1517 | * It'd be great if the workqueue API had a way to pass | |
1518 | * in a mask and had some smarts for more clever placement. | |
1519 | * For now we just round-robin here, switching for every | |
1520 | * BLK_MQ_CPU_WORK_BATCH queued items. | |
1521 | */ | |
1522 | static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) | |
1523 | { | |
7bed4595 | 1524 | bool tried = false; |
476f8c98 | 1525 | int next_cpu = hctx->next_cpu; |
7bed4595 | 1526 | |
b657d7e6 CH |
1527 | if (hctx->queue->nr_hw_queues == 1) |
1528 | return WORK_CPU_UNBOUND; | |
506e931f JA |
1529 | |
1530 | if (--hctx->next_cpu_batch <= 0) { | |
7bed4595 | 1531 | select_cpu: |
476f8c98 | 1532 | next_cpu = cpumask_next_and(next_cpu, hctx->cpumask, |
20e4d813 | 1533 | cpu_online_mask); |
506e931f | 1534 | if (next_cpu >= nr_cpu_ids) |
f82ddf19 | 1535 | next_cpu = blk_mq_first_mapped_cpu(hctx); |
506e931f JA |
1536 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; |
1537 | } | |
1538 | ||
7bed4595 ML |
1539 | /* |
1540 | * Do unbound schedule if we can't find a online CPU for this hctx, | |
1541 | * and it should only happen in the path of handling CPU DEAD. | |
1542 | */ | |
476f8c98 | 1543 | if (!cpu_online(next_cpu)) { |
7bed4595 ML |
1544 | if (!tried) { |
1545 | tried = true; | |
1546 | goto select_cpu; | |
1547 | } | |
1548 | ||
1549 | /* | |
1550 | * Make sure to re-select CPU next time once after CPUs | |
1551 | * in hctx->cpumask become online again. | |
1552 | */ | |
476f8c98 | 1553 | hctx->next_cpu = next_cpu; |
7bed4595 ML |
1554 | hctx->next_cpu_batch = 1; |
1555 | return WORK_CPU_UNBOUND; | |
1556 | } | |
476f8c98 ML |
1557 | |
1558 | hctx->next_cpu = next_cpu; | |
1559 | return next_cpu; | |
506e931f JA |
1560 | } |
1561 | ||
105663f7 AA |
1562 | /** |
1563 | * __blk_mq_delay_run_hw_queue - Run (or schedule to run) a hardware queue. | |
1564 | * @hctx: Pointer to the hardware queue to run. | |
1565 | * @async: If we want to run the queue asynchronously. | |
fa94ba8a | 1566 | * @msecs: Milliseconds of delay to wait before running the queue. |
105663f7 AA |
1567 | * |
1568 | * If !@async, try to run the queue now. Else, run the queue asynchronously and | |
1569 | * with a delay of @msecs. | |
1570 | */ | |
7587a5ae BVA |
1571 | static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async, |
1572 | unsigned long msecs) | |
320ae51f | 1573 | { |
5435c023 | 1574 | if (unlikely(blk_mq_hctx_stopped(hctx))) |
320ae51f JA |
1575 | return; |
1576 | ||
1b792f2f | 1577 | if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) { |
2a90d4aa PB |
1578 | int cpu = get_cpu(); |
1579 | if (cpumask_test_cpu(cpu, hctx->cpumask)) { | |
398205b8 | 1580 | __blk_mq_run_hw_queue(hctx); |
2a90d4aa | 1581 | put_cpu(); |
398205b8 PB |
1582 | return; |
1583 | } | |
e4043dcf | 1584 | |
2a90d4aa | 1585 | put_cpu(); |
e4043dcf | 1586 | } |
398205b8 | 1587 | |
ae943d20 BVA |
1588 | kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work, |
1589 | msecs_to_jiffies(msecs)); | |
7587a5ae BVA |
1590 | } |
1591 | ||
105663f7 AA |
1592 | /** |
1593 | * blk_mq_delay_run_hw_queue - Run a hardware queue asynchronously. | |
1594 | * @hctx: Pointer to the hardware queue to run. | |
fa94ba8a | 1595 | * @msecs: Milliseconds of delay to wait before running the queue. |
105663f7 AA |
1596 | * |
1597 | * Run a hardware queue asynchronously with a delay of @msecs. | |
1598 | */ | |
7587a5ae BVA |
1599 | void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) |
1600 | { | |
1601 | __blk_mq_delay_run_hw_queue(hctx, true, msecs); | |
1602 | } | |
1603 | EXPORT_SYMBOL(blk_mq_delay_run_hw_queue); | |
1604 | ||
105663f7 AA |
1605 | /** |
1606 | * blk_mq_run_hw_queue - Start to run a hardware queue. | |
1607 | * @hctx: Pointer to the hardware queue to run. | |
1608 | * @async: If we want to run the queue asynchronously. | |
1609 | * | |
1610 | * Check if the request queue is not in a quiesced state and if there are | |
1611 | * pending requests to be sent. If this is true, run the queue to send requests | |
1612 | * to hardware. | |
1613 | */ | |
626fb735 | 1614 | void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
7587a5ae | 1615 | { |
24f5a90f ML |
1616 | int srcu_idx; |
1617 | bool need_run; | |
1618 | ||
1619 | /* | |
1620 | * When queue is quiesced, we may be switching io scheduler, or | |
1621 | * updating nr_hw_queues, or other things, and we can't run queue | |
1622 | * any more, even __blk_mq_hctx_has_pending() can't be called safely. | |
1623 | * | |
1624 | * And queue will be rerun in blk_mq_unquiesce_queue() if it is | |
1625 | * quiesced. | |
1626 | */ | |
04ced159 JA |
1627 | hctx_lock(hctx, &srcu_idx); |
1628 | need_run = !blk_queue_quiesced(hctx->queue) && | |
1629 | blk_mq_hctx_has_pending(hctx); | |
1630 | hctx_unlock(hctx, srcu_idx); | |
24f5a90f | 1631 | |
626fb735 | 1632 | if (need_run) |
79f720a7 | 1633 | __blk_mq_delay_run_hw_queue(hctx, async, 0); |
320ae51f | 1634 | } |
5b727272 | 1635 | EXPORT_SYMBOL(blk_mq_run_hw_queue); |
320ae51f | 1636 | |
b6e68ee8 JK |
1637 | /* |
1638 | * Is the request queue handled by an IO scheduler that does not respect | |
1639 | * hardware queues when dispatching? | |
1640 | */ | |
1641 | static bool blk_mq_has_sqsched(struct request_queue *q) | |
1642 | { | |
1643 | struct elevator_queue *e = q->elevator; | |
1644 | ||
1645 | if (e && e->type->ops.dispatch_request && | |
1646 | !(e->type->elevator_features & ELEVATOR_F_MQ_AWARE)) | |
1647 | return true; | |
1648 | return false; | |
1649 | } | |
1650 | ||
1651 | /* | |
1652 | * Return prefered queue to dispatch from (if any) for non-mq aware IO | |
1653 | * scheduler. | |
1654 | */ | |
1655 | static struct blk_mq_hw_ctx *blk_mq_get_sq_hctx(struct request_queue *q) | |
1656 | { | |
1657 | struct blk_mq_hw_ctx *hctx; | |
1658 | ||
1659 | /* | |
1660 | * If the IO scheduler does not respect hardware queues when | |
1661 | * dispatching, we just don't bother with multiple HW queues and | |
1662 | * dispatch from hctx for the current CPU since running multiple queues | |
1663 | * just causes lock contention inside the scheduler and pointless cache | |
1664 | * bouncing. | |
1665 | */ | |
1666 | hctx = blk_mq_map_queue_type(q, HCTX_TYPE_DEFAULT, | |
1667 | raw_smp_processor_id()); | |
1668 | if (!blk_mq_hctx_stopped(hctx)) | |
1669 | return hctx; | |
1670 | return NULL; | |
1671 | } | |
1672 | ||
105663f7 | 1673 | /** |
24f7bb88 | 1674 | * blk_mq_run_hw_queues - Run all hardware queues in a request queue. |
105663f7 AA |
1675 | * @q: Pointer to the request queue to run. |
1676 | * @async: If we want to run the queue asynchronously. | |
1677 | */ | |
b94ec296 | 1678 | void blk_mq_run_hw_queues(struct request_queue *q, bool async) |
320ae51f | 1679 | { |
b6e68ee8 | 1680 | struct blk_mq_hw_ctx *hctx, *sq_hctx; |
320ae51f JA |
1681 | int i; |
1682 | ||
b6e68ee8 JK |
1683 | sq_hctx = NULL; |
1684 | if (blk_mq_has_sqsched(q)) | |
1685 | sq_hctx = blk_mq_get_sq_hctx(q); | |
320ae51f | 1686 | queue_for_each_hw_ctx(q, hctx, i) { |
79f720a7 | 1687 | if (blk_mq_hctx_stopped(hctx)) |
320ae51f | 1688 | continue; |
b6e68ee8 JK |
1689 | /* |
1690 | * Dispatch from this hctx either if there's no hctx preferred | |
1691 | * by IO scheduler or if it has requests that bypass the | |
1692 | * scheduler. | |
1693 | */ | |
1694 | if (!sq_hctx || sq_hctx == hctx || | |
1695 | !list_empty_careful(&hctx->dispatch)) | |
1696 | blk_mq_run_hw_queue(hctx, async); | |
320ae51f JA |
1697 | } |
1698 | } | |
b94ec296 | 1699 | EXPORT_SYMBOL(blk_mq_run_hw_queues); |
320ae51f | 1700 | |
b9151e7b DA |
1701 | /** |
1702 | * blk_mq_delay_run_hw_queues - Run all hardware queues asynchronously. | |
1703 | * @q: Pointer to the request queue to run. | |
fa94ba8a | 1704 | * @msecs: Milliseconds of delay to wait before running the queues. |
b9151e7b DA |
1705 | */ |
1706 | void blk_mq_delay_run_hw_queues(struct request_queue *q, unsigned long msecs) | |
1707 | { | |
b6e68ee8 | 1708 | struct blk_mq_hw_ctx *hctx, *sq_hctx; |
b9151e7b DA |
1709 | int i; |
1710 | ||
b6e68ee8 JK |
1711 | sq_hctx = NULL; |
1712 | if (blk_mq_has_sqsched(q)) | |
1713 | sq_hctx = blk_mq_get_sq_hctx(q); | |
b9151e7b DA |
1714 | queue_for_each_hw_ctx(q, hctx, i) { |
1715 | if (blk_mq_hctx_stopped(hctx)) | |
1716 | continue; | |
b6e68ee8 JK |
1717 | /* |
1718 | * Dispatch from this hctx either if there's no hctx preferred | |
1719 | * by IO scheduler or if it has requests that bypass the | |
1720 | * scheduler. | |
1721 | */ | |
1722 | if (!sq_hctx || sq_hctx == hctx || | |
1723 | !list_empty_careful(&hctx->dispatch)) | |
1724 | blk_mq_delay_run_hw_queue(hctx, msecs); | |
b9151e7b DA |
1725 | } |
1726 | } | |
1727 | EXPORT_SYMBOL(blk_mq_delay_run_hw_queues); | |
1728 | ||
fd001443 BVA |
1729 | /** |
1730 | * blk_mq_queue_stopped() - check whether one or more hctxs have been stopped | |
1731 | * @q: request queue. | |
1732 | * | |
1733 | * The caller is responsible for serializing this function against | |
1734 | * blk_mq_{start,stop}_hw_queue(). | |
1735 | */ | |
1736 | bool blk_mq_queue_stopped(struct request_queue *q) | |
1737 | { | |
1738 | struct blk_mq_hw_ctx *hctx; | |
1739 | int i; | |
1740 | ||
1741 | queue_for_each_hw_ctx(q, hctx, i) | |
1742 | if (blk_mq_hctx_stopped(hctx)) | |
1743 | return true; | |
1744 | ||
1745 | return false; | |
1746 | } | |
1747 | EXPORT_SYMBOL(blk_mq_queue_stopped); | |
1748 | ||
39a70c76 ML |
1749 | /* |
1750 | * This function is often used for pausing .queue_rq() by driver when | |
1751 | * there isn't enough resource or some conditions aren't satisfied, and | |
4d606219 | 1752 | * BLK_STS_RESOURCE is usually returned. |
39a70c76 ML |
1753 | * |
1754 | * We do not guarantee that dispatch can be drained or blocked | |
1755 | * after blk_mq_stop_hw_queue() returns. Please use | |
1756 | * blk_mq_quiesce_queue() for that requirement. | |
1757 | */ | |
2719aa21 JA |
1758 | void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx) |
1759 | { | |
641a9ed6 | 1760 | cancel_delayed_work(&hctx->run_work); |
280d45f6 | 1761 | |
641a9ed6 | 1762 | set_bit(BLK_MQ_S_STOPPED, &hctx->state); |
2719aa21 | 1763 | } |
641a9ed6 | 1764 | EXPORT_SYMBOL(blk_mq_stop_hw_queue); |
2719aa21 | 1765 | |
39a70c76 ML |
1766 | /* |
1767 | * This function is often used for pausing .queue_rq() by driver when | |
1768 | * there isn't enough resource or some conditions aren't satisfied, and | |
4d606219 | 1769 | * BLK_STS_RESOURCE is usually returned. |
39a70c76 ML |
1770 | * |
1771 | * We do not guarantee that dispatch can be drained or blocked | |
1772 | * after blk_mq_stop_hw_queues() returns. Please use | |
1773 | * blk_mq_quiesce_queue() for that requirement. | |
1774 | */ | |
2719aa21 JA |
1775 | void blk_mq_stop_hw_queues(struct request_queue *q) |
1776 | { | |
641a9ed6 ML |
1777 | struct blk_mq_hw_ctx *hctx; |
1778 | int i; | |
1779 | ||
1780 | queue_for_each_hw_ctx(q, hctx, i) | |
1781 | blk_mq_stop_hw_queue(hctx); | |
280d45f6 CH |
1782 | } |
1783 | EXPORT_SYMBOL(blk_mq_stop_hw_queues); | |
1784 | ||
320ae51f JA |
1785 | void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx) |
1786 | { | |
1787 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
e4043dcf | 1788 | |
0ffbce80 | 1789 | blk_mq_run_hw_queue(hctx, false); |
320ae51f JA |
1790 | } |
1791 | EXPORT_SYMBOL(blk_mq_start_hw_queue); | |
1792 | ||
2f268556 CH |
1793 | void blk_mq_start_hw_queues(struct request_queue *q) |
1794 | { | |
1795 | struct blk_mq_hw_ctx *hctx; | |
1796 | int i; | |
1797 | ||
1798 | queue_for_each_hw_ctx(q, hctx, i) | |
1799 | blk_mq_start_hw_queue(hctx); | |
1800 | } | |
1801 | EXPORT_SYMBOL(blk_mq_start_hw_queues); | |
1802 | ||
ae911c5e JA |
1803 | void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
1804 | { | |
1805 | if (!blk_mq_hctx_stopped(hctx)) | |
1806 | return; | |
1807 | ||
1808 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
1809 | blk_mq_run_hw_queue(hctx, async); | |
1810 | } | |
1811 | EXPORT_SYMBOL_GPL(blk_mq_start_stopped_hw_queue); | |
1812 | ||
1b4a3258 | 1813 | void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
1814 | { |
1815 | struct blk_mq_hw_ctx *hctx; | |
1816 | int i; | |
1817 | ||
ae911c5e JA |
1818 | queue_for_each_hw_ctx(q, hctx, i) |
1819 | blk_mq_start_stopped_hw_queue(hctx, async); | |
320ae51f JA |
1820 | } |
1821 | EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); | |
1822 | ||
70f4db63 | 1823 | static void blk_mq_run_work_fn(struct work_struct *work) |
320ae51f JA |
1824 | { |
1825 | struct blk_mq_hw_ctx *hctx; | |
1826 | ||
9f993737 | 1827 | hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work); |
320ae51f | 1828 | |
21c6e939 | 1829 | /* |
15fe8a90 | 1830 | * If we are stopped, don't run the queue. |
21c6e939 | 1831 | */ |
0841031a | 1832 | if (blk_mq_hctx_stopped(hctx)) |
0196d6b4 | 1833 | return; |
7587a5ae BVA |
1834 | |
1835 | __blk_mq_run_hw_queue(hctx); | |
1836 | } | |
1837 | ||
cfd0c552 | 1838 | static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx, |
cfd0c552 ML |
1839 | struct request *rq, |
1840 | bool at_head) | |
320ae51f | 1841 | { |
e57690fe | 1842 | struct blk_mq_ctx *ctx = rq->mq_ctx; |
c16d6b5a | 1843 | enum hctx_type type = hctx->type; |
e57690fe | 1844 | |
7b607814 BVA |
1845 | lockdep_assert_held(&ctx->lock); |
1846 | ||
a54895fa | 1847 | trace_block_rq_insert(rq); |
01b983c9 | 1848 | |
72a0a36e | 1849 | if (at_head) |
c16d6b5a | 1850 | list_add(&rq->queuelist, &ctx->rq_lists[type]); |
72a0a36e | 1851 | else |
c16d6b5a | 1852 | list_add_tail(&rq->queuelist, &ctx->rq_lists[type]); |
cfd0c552 | 1853 | } |
4bb659b1 | 1854 | |
2c3ad667 JA |
1855 | void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, |
1856 | bool at_head) | |
cfd0c552 ML |
1857 | { |
1858 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
1859 | ||
7b607814 BVA |
1860 | lockdep_assert_held(&ctx->lock); |
1861 | ||
e57690fe | 1862 | __blk_mq_insert_req_list(hctx, rq, at_head); |
320ae51f | 1863 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f JA |
1864 | } |
1865 | ||
105663f7 AA |
1866 | /** |
1867 | * blk_mq_request_bypass_insert - Insert a request at dispatch list. | |
1868 | * @rq: Pointer to request to be inserted. | |
26bfeb26 | 1869 | * @at_head: true if the request should be inserted at the head of the list. |
105663f7 AA |
1870 | * @run_queue: If we should run the hardware queue after inserting the request. |
1871 | * | |
157f377b JA |
1872 | * Should only be used carefully, when the caller knows we want to |
1873 | * bypass a potential IO scheduler on the target device. | |
1874 | */ | |
01e99aec ML |
1875 | void blk_mq_request_bypass_insert(struct request *rq, bool at_head, |
1876 | bool run_queue) | |
157f377b | 1877 | { |
ea4f995e | 1878 | struct blk_mq_hw_ctx *hctx = rq->mq_hctx; |
157f377b JA |
1879 | |
1880 | spin_lock(&hctx->lock); | |
01e99aec ML |
1881 | if (at_head) |
1882 | list_add(&rq->queuelist, &hctx->dispatch); | |
1883 | else | |
1884 | list_add_tail(&rq->queuelist, &hctx->dispatch); | |
157f377b JA |
1885 | spin_unlock(&hctx->lock); |
1886 | ||
b0850297 ML |
1887 | if (run_queue) |
1888 | blk_mq_run_hw_queue(hctx, false); | |
157f377b JA |
1889 | } |
1890 | ||
bd166ef1 JA |
1891 | void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, |
1892 | struct list_head *list) | |
320ae51f JA |
1893 | |
1894 | { | |
3f0cedc7 | 1895 | struct request *rq; |
c16d6b5a | 1896 | enum hctx_type type = hctx->type; |
3f0cedc7 | 1897 | |
320ae51f JA |
1898 | /* |
1899 | * preemption doesn't flush plug list, so it's possible ctx->cpu is | |
1900 | * offline now | |
1901 | */ | |
3f0cedc7 | 1902 | list_for_each_entry(rq, list, queuelist) { |
e57690fe | 1903 | BUG_ON(rq->mq_ctx != ctx); |
a54895fa | 1904 | trace_block_rq_insert(rq); |
320ae51f | 1905 | } |
3f0cedc7 ML |
1906 | |
1907 | spin_lock(&ctx->lock); | |
c16d6b5a | 1908 | list_splice_tail_init(list, &ctx->rq_lists[type]); |
cfd0c552 | 1909 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f | 1910 | spin_unlock(&ctx->lock); |
320ae51f JA |
1911 | } |
1912 | ||
4f0f586b ST |
1913 | static int plug_rq_cmp(void *priv, const struct list_head *a, |
1914 | const struct list_head *b) | |
320ae51f JA |
1915 | { |
1916 | struct request *rqa = container_of(a, struct request, queuelist); | |
1917 | struct request *rqb = container_of(b, struct request, queuelist); | |
1918 | ||
7d30a621 PB |
1919 | if (rqa->mq_ctx != rqb->mq_ctx) |
1920 | return rqa->mq_ctx > rqb->mq_ctx; | |
1921 | if (rqa->mq_hctx != rqb->mq_hctx) | |
1922 | return rqa->mq_hctx > rqb->mq_hctx; | |
3110fc79 JA |
1923 | |
1924 | return blk_rq_pos(rqa) > blk_rq_pos(rqb); | |
320ae51f JA |
1925 | } |
1926 | ||
1927 | void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) | |
1928 | { | |
320ae51f | 1929 | LIST_HEAD(list); |
320ae51f | 1930 | |
95ed0c5b PB |
1931 | if (list_empty(&plug->mq_list)) |
1932 | return; | |
320ae51f JA |
1933 | list_splice_init(&plug->mq_list, &list); |
1934 | ||
ce5b009c JA |
1935 | if (plug->rq_count > 2 && plug->multiple_queues) |
1936 | list_sort(NULL, &list, plug_rq_cmp); | |
320ae51f | 1937 | |
bcc816df DZ |
1938 | plug->rq_count = 0; |
1939 | ||
95ed0c5b PB |
1940 | do { |
1941 | struct list_head rq_list; | |
1942 | struct request *rq, *head_rq = list_entry_rq(list.next); | |
1943 | struct list_head *pos = &head_rq->queuelist; /* skip first */ | |
1944 | struct blk_mq_hw_ctx *this_hctx = head_rq->mq_hctx; | |
1945 | struct blk_mq_ctx *this_ctx = head_rq->mq_ctx; | |
1946 | unsigned int depth = 1; | |
1947 | ||
1948 | list_for_each_continue(pos, &list) { | |
1949 | rq = list_entry_rq(pos); | |
1950 | BUG_ON(!rq->q); | |
1951 | if (rq->mq_hctx != this_hctx || rq->mq_ctx != this_ctx) | |
1952 | break; | |
1953 | depth++; | |
320ae51f JA |
1954 | } |
1955 | ||
95ed0c5b PB |
1956 | list_cut_before(&rq_list, &list, pos); |
1957 | trace_block_unplug(head_rq->q, depth, !from_schedule); | |
67cae4c9 | 1958 | blk_mq_sched_insert_requests(this_hctx, this_ctx, &rq_list, |
bd166ef1 | 1959 | from_schedule); |
95ed0c5b | 1960 | } while(!list_empty(&list)); |
320ae51f JA |
1961 | } |
1962 | ||
14ccb66b CH |
1963 | static void blk_mq_bio_to_request(struct request *rq, struct bio *bio, |
1964 | unsigned int nr_segs) | |
320ae51f | 1965 | { |
93f221ae EB |
1966 | int err; |
1967 | ||
f924cdde CH |
1968 | if (bio->bi_opf & REQ_RAHEAD) |
1969 | rq->cmd_flags |= REQ_FAILFAST_MASK; | |
1970 | ||
1971 | rq->__sector = bio->bi_iter.bi_sector; | |
1972 | rq->write_hint = bio->bi_write_hint; | |
14ccb66b | 1973 | blk_rq_bio_prep(rq, bio, nr_segs); |
93f221ae EB |
1974 | |
1975 | /* This can't fail, since GFP_NOIO includes __GFP_DIRECT_RECLAIM. */ | |
1976 | err = blk_crypto_rq_bio_prep(rq, bio, GFP_NOIO); | |
1977 | WARN_ON_ONCE(err); | |
4b570521 | 1978 | |
b5af37ab | 1979 | blk_account_io_start(rq); |
320ae51f JA |
1980 | } |
1981 | ||
0f95549c MS |
1982 | static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx, |
1983 | struct request *rq, | |
be94f058 | 1984 | blk_qc_t *cookie, bool last) |
f984df1f | 1985 | { |
f984df1f | 1986 | struct request_queue *q = rq->q; |
f984df1f SL |
1987 | struct blk_mq_queue_data bd = { |
1988 | .rq = rq, | |
be94f058 | 1989 | .last = last, |
f984df1f | 1990 | }; |
bd166ef1 | 1991 | blk_qc_t new_cookie; |
f06345ad | 1992 | blk_status_t ret; |
0f95549c MS |
1993 | |
1994 | new_cookie = request_to_qc_t(hctx, rq); | |
1995 | ||
1996 | /* | |
1997 | * For OK queue, we are done. For error, caller may kill it. | |
1998 | * Any other error (busy), just add it to our list as we | |
1999 | * previously would have done. | |
2000 | */ | |
2001 | ret = q->mq_ops->queue_rq(hctx, &bd); | |
2002 | switch (ret) { | |
2003 | case BLK_STS_OK: | |
6ce3dd6e | 2004 | blk_mq_update_dispatch_busy(hctx, false); |
0f95549c MS |
2005 | *cookie = new_cookie; |
2006 | break; | |
2007 | case BLK_STS_RESOURCE: | |
86ff7c2a | 2008 | case BLK_STS_DEV_RESOURCE: |
6ce3dd6e | 2009 | blk_mq_update_dispatch_busy(hctx, true); |
0f95549c MS |
2010 | __blk_mq_requeue_request(rq); |
2011 | break; | |
2012 | default: | |
6ce3dd6e | 2013 | blk_mq_update_dispatch_busy(hctx, false); |
0f95549c MS |
2014 | *cookie = BLK_QC_T_NONE; |
2015 | break; | |
2016 | } | |
2017 | ||
2018 | return ret; | |
2019 | } | |
2020 | ||
fd9c40f6 | 2021 | static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, |
0f95549c | 2022 | struct request *rq, |
396eaf21 | 2023 | blk_qc_t *cookie, |
fd9c40f6 | 2024 | bool bypass_insert, bool last) |
0f95549c MS |
2025 | { |
2026 | struct request_queue *q = rq->q; | |
d964f04a | 2027 | bool run_queue = true; |
2a5a24aa | 2028 | int budget_token; |
d964f04a | 2029 | |
23d4ee19 | 2030 | /* |
fd9c40f6 | 2031 | * RCU or SRCU read lock is needed before checking quiesced flag. |
23d4ee19 | 2032 | * |
fd9c40f6 BVA |
2033 | * When queue is stopped or quiesced, ignore 'bypass_insert' from |
2034 | * blk_mq_request_issue_directly(), and return BLK_STS_OK to caller, | |
2035 | * and avoid driver to try to dispatch again. | |
23d4ee19 | 2036 | */ |
fd9c40f6 | 2037 | if (blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(q)) { |
d964f04a | 2038 | run_queue = false; |
fd9c40f6 BVA |
2039 | bypass_insert = false; |
2040 | goto insert; | |
d964f04a | 2041 | } |
f984df1f | 2042 | |
fd9c40f6 BVA |
2043 | if (q->elevator && !bypass_insert) |
2044 | goto insert; | |
2253efc8 | 2045 | |
2a5a24aa ML |
2046 | budget_token = blk_mq_get_dispatch_budget(q); |
2047 | if (budget_token < 0) | |
fd9c40f6 | 2048 | goto insert; |
bd166ef1 | 2049 | |
2a5a24aa ML |
2050 | blk_mq_set_rq_budget_token(rq, budget_token); |
2051 | ||
8ab6bb9e | 2052 | if (!blk_mq_get_driver_tag(rq)) { |
2a5a24aa | 2053 | blk_mq_put_dispatch_budget(q, budget_token); |
fd9c40f6 | 2054 | goto insert; |
88022d72 | 2055 | } |
de148297 | 2056 | |
fd9c40f6 BVA |
2057 | return __blk_mq_issue_directly(hctx, rq, cookie, last); |
2058 | insert: | |
2059 | if (bypass_insert) | |
2060 | return BLK_STS_RESOURCE; | |
2061 | ||
db03f88f ML |
2062 | blk_mq_sched_insert_request(rq, false, run_queue, false); |
2063 | ||
fd9c40f6 BVA |
2064 | return BLK_STS_OK; |
2065 | } | |
2066 | ||
105663f7 AA |
2067 | /** |
2068 | * blk_mq_try_issue_directly - Try to send a request directly to device driver. | |
2069 | * @hctx: Pointer of the associated hardware queue. | |
2070 | * @rq: Pointer to request to be sent. | |
2071 | * @cookie: Request queue cookie. | |
2072 | * | |
2073 | * If the device has enough resources to accept a new request now, send the | |
2074 | * request directly to device driver. Else, insert at hctx->dispatch queue, so | |
2075 | * we can try send it another time in the future. Requests inserted at this | |
2076 | * queue have higher priority. | |
2077 | */ | |
fd9c40f6 BVA |
2078 | static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, |
2079 | struct request *rq, blk_qc_t *cookie) | |
2080 | { | |
2081 | blk_status_t ret; | |
2082 | int srcu_idx; | |
2083 | ||
2084 | might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING); | |
2085 | ||
2086 | hctx_lock(hctx, &srcu_idx); | |
2087 | ||
2088 | ret = __blk_mq_try_issue_directly(hctx, rq, cookie, false, true); | |
2089 | if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) | |
01e99aec | 2090 | blk_mq_request_bypass_insert(rq, false, true); |
fd9c40f6 BVA |
2091 | else if (ret != BLK_STS_OK) |
2092 | blk_mq_end_request(rq, ret); | |
2093 | ||
2094 | hctx_unlock(hctx, srcu_idx); | |
2095 | } | |
2096 | ||
2097 | blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last) | |
2098 | { | |
2099 | blk_status_t ret; | |
2100 | int srcu_idx; | |
2101 | blk_qc_t unused_cookie; | |
2102 | struct blk_mq_hw_ctx *hctx = rq->mq_hctx; | |
2103 | ||
2104 | hctx_lock(hctx, &srcu_idx); | |
2105 | ret = __blk_mq_try_issue_directly(hctx, rq, &unused_cookie, true, last); | |
04ced159 | 2106 | hctx_unlock(hctx, srcu_idx); |
7f556a44 JW |
2107 | |
2108 | return ret; | |
5eb6126e CH |
2109 | } |
2110 | ||
6ce3dd6e ML |
2111 | void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, |
2112 | struct list_head *list) | |
2113 | { | |
536167d4 | 2114 | int queued = 0; |
632bfb63 | 2115 | int errors = 0; |
536167d4 | 2116 | |
6ce3dd6e | 2117 | while (!list_empty(list)) { |
fd9c40f6 | 2118 | blk_status_t ret; |
6ce3dd6e ML |
2119 | struct request *rq = list_first_entry(list, struct request, |
2120 | queuelist); | |
2121 | ||
2122 | list_del_init(&rq->queuelist); | |
fd9c40f6 BVA |
2123 | ret = blk_mq_request_issue_directly(rq, list_empty(list)); |
2124 | if (ret != BLK_STS_OK) { | |
2125 | if (ret == BLK_STS_RESOURCE || | |
2126 | ret == BLK_STS_DEV_RESOURCE) { | |
01e99aec | 2127 | blk_mq_request_bypass_insert(rq, false, |
c616cbee | 2128 | list_empty(list)); |
fd9c40f6 BVA |
2129 | break; |
2130 | } | |
2131 | blk_mq_end_request(rq, ret); | |
632bfb63 | 2132 | errors++; |
536167d4 KB |
2133 | } else |
2134 | queued++; | |
6ce3dd6e | 2135 | } |
d666ba98 JA |
2136 | |
2137 | /* | |
2138 | * If we didn't flush the entire list, we could have told | |
2139 | * the driver there was more coming, but that turned out to | |
2140 | * be a lie. | |
2141 | */ | |
632bfb63 | 2142 | if ((!list_empty(list) || errors) && |
2143 | hctx->queue->mq_ops->commit_rqs && queued) | |
d666ba98 | 2144 | hctx->queue->mq_ops->commit_rqs(hctx); |
6ce3dd6e ML |
2145 | } |
2146 | ||
ce5b009c JA |
2147 | static void blk_add_rq_to_plug(struct blk_plug *plug, struct request *rq) |
2148 | { | |
2149 | list_add_tail(&rq->queuelist, &plug->mq_list); | |
2150 | plug->rq_count++; | |
2151 | if (!plug->multiple_queues && !list_is_singular(&plug->mq_list)) { | |
2152 | struct request *tmp; | |
2153 | ||
2154 | tmp = list_first_entry(&plug->mq_list, struct request, | |
2155 | queuelist); | |
2156 | if (tmp->q != rq->q) | |
2157 | plug->multiple_queues = true; | |
2158 | } | |
2159 | } | |
2160 | ||
105663f7 | 2161 | /** |
c62b37d9 | 2162 | * blk_mq_submit_bio - Create and send a request to block device. |
105663f7 AA |
2163 | * @bio: Bio pointer. |
2164 | * | |
2165 | * Builds up a request structure from @q and @bio and send to the device. The | |
2166 | * request may not be queued directly to hardware if: | |
2167 | * * This request can be merged with another one | |
2168 | * * We want to place request at plug queue for possible future merging | |
2169 | * * There is an IO scheduler active at this queue | |
2170 | * | |
2171 | * It will not queue the request if there is an error with the bio, or at the | |
2172 | * request creation. | |
2173 | * | |
2174 | * Returns: Request queue cookie. | |
2175 | */ | |
c62b37d9 | 2176 | blk_qc_t blk_mq_submit_bio(struct bio *bio) |
07068d5b | 2177 | { |
309dca30 | 2178 | struct request_queue *q = bio->bi_bdev->bd_disk->queue; |
ef295ecf | 2179 | const int is_sync = op_is_sync(bio->bi_opf); |
f73f44eb | 2180 | const int is_flush_fua = op_is_flush(bio->bi_opf); |
e6e7abff CH |
2181 | struct blk_mq_alloc_data data = { |
2182 | .q = q, | |
2183 | }; | |
07068d5b | 2184 | struct request *rq; |
f984df1f | 2185 | struct blk_plug *plug; |
5b3f341f | 2186 | struct request *same_queue_rq = NULL; |
14ccb66b | 2187 | unsigned int nr_segs; |
7b371636 | 2188 | blk_qc_t cookie; |
a892c8d5 | 2189 | blk_status_t ret; |
cc29e1bf | 2190 | bool hipri; |
07068d5b JA |
2191 | |
2192 | blk_queue_bounce(q, &bio); | |
f695ca38 | 2193 | __blk_queue_split(&bio, &nr_segs); |
f36ea50c | 2194 | |
e23947bd | 2195 | if (!bio_integrity_prep(bio)) |
ac7c5675 | 2196 | goto queue_exit; |
07068d5b | 2197 | |
87c279e6 | 2198 | if (!is_flush_fua && !blk_queue_nomerges(q) && |
14ccb66b | 2199 | blk_attempt_plug_merge(q, bio, nr_segs, &same_queue_rq)) |
ac7c5675 | 2200 | goto queue_exit; |
f984df1f | 2201 | |
14ccb66b | 2202 | if (blk_mq_sched_bio_merge(q, bio, nr_segs)) |
ac7c5675 | 2203 | goto queue_exit; |
bd166ef1 | 2204 | |
d5337560 | 2205 | rq_qos_throttle(q, bio); |
87760e5e | 2206 | |
cc29e1bf JX |
2207 | hipri = bio->bi_opf & REQ_HIPRI; |
2208 | ||
7809167d | 2209 | data.cmd_flags = bio->bi_opf; |
e6e7abff | 2210 | rq = __blk_mq_alloc_request(&data); |
87760e5e | 2211 | if (unlikely(!rq)) { |
c1c80384 | 2212 | rq_qos_cleanup(q, bio); |
7b6620d7 | 2213 | if (bio->bi_opf & REQ_NOWAIT) |
03a07c92 | 2214 | bio_wouldblock_error(bio); |
ac7c5675 | 2215 | goto queue_exit; |
87760e5e JA |
2216 | } |
2217 | ||
e8a676d6 | 2218 | trace_block_getrq(bio); |
d6f1dda2 | 2219 | |
c1c80384 | 2220 | rq_qos_track(q, rq, bio); |
07068d5b | 2221 | |
fd2d3326 | 2222 | cookie = request_to_qc_t(data.hctx, rq); |
07068d5b | 2223 | |
970d168d BVA |
2224 | blk_mq_bio_to_request(rq, bio, nr_segs); |
2225 | ||
a892c8d5 ST |
2226 | ret = blk_crypto_init_request(rq); |
2227 | if (ret != BLK_STS_OK) { | |
2228 | bio->bi_status = ret; | |
2229 | bio_endio(bio); | |
2230 | blk_mq_free_request(rq); | |
2231 | return BLK_QC_T_NONE; | |
2232 | } | |
2233 | ||
b49773e7 | 2234 | plug = blk_mq_plug(q, bio); |
07068d5b | 2235 | if (unlikely(is_flush_fua)) { |
105663f7 | 2236 | /* Bypass scheduler for flush requests */ |
923218f6 ML |
2237 | blk_insert_flush(rq); |
2238 | blk_mq_run_hw_queue(data.hctx, true); | |
03f26d8f ML |
2239 | } else if (plug && (q->nr_hw_queues == 1 || |
2240 | blk_mq_is_sbitmap_shared(rq->mq_hctx->flags) || | |
2241 | q->mq_ops->commit_rqs || !blk_queue_nonrot(q))) { | |
b2c5d16b JA |
2242 | /* |
2243 | * Use plugging if we have a ->commit_rqs() hook as well, as | |
2244 | * we know the driver uses bd->last in a smart fashion. | |
3154df26 ML |
2245 | * |
2246 | * Use normal plugging if this disk is slow HDD, as sequential | |
2247 | * IO may benefit a lot from plug merging. | |
b2c5d16b | 2248 | */ |
5f0ed774 | 2249 | unsigned int request_count = plug->rq_count; |
600271d9 SL |
2250 | struct request *last = NULL; |
2251 | ||
676d0607 | 2252 | if (!request_count) |
e6c4438b | 2253 | trace_block_plug(q); |
600271d9 SL |
2254 | else |
2255 | last = list_entry_rq(plug->mq_list.prev); | |
b094f89c | 2256 | |
600271d9 SL |
2257 | if (request_count >= BLK_MAX_REQUEST_COUNT || (last && |
2258 | blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE)) { | |
e6c4438b JM |
2259 | blk_flush_plug_list(plug, false); |
2260 | trace_block_plug(q); | |
320ae51f | 2261 | } |
b094f89c | 2262 | |
ce5b009c | 2263 | blk_add_rq_to_plug(plug, rq); |
a12de1d4 | 2264 | } else if (q->elevator) { |
105663f7 | 2265 | /* Insert the request at the IO scheduler queue */ |
a12de1d4 | 2266 | blk_mq_sched_insert_request(rq, false, true, true); |
2299722c | 2267 | } else if (plug && !blk_queue_nomerges(q)) { |
07068d5b | 2268 | /* |
6a83e74d | 2269 | * We do limited plugging. If the bio can be merged, do that. |
f984df1f SL |
2270 | * Otherwise the existing request in the plug list will be |
2271 | * issued. So the plug list will have one request at most | |
2299722c CH |
2272 | * The plug list might get flushed before this. If that happens, |
2273 | * the plug list is empty, and same_queue_rq is invalid. | |
07068d5b | 2274 | */ |
2299722c CH |
2275 | if (list_empty(&plug->mq_list)) |
2276 | same_queue_rq = NULL; | |
4711b573 | 2277 | if (same_queue_rq) { |
2299722c | 2278 | list_del_init(&same_queue_rq->queuelist); |
4711b573 JA |
2279 | plug->rq_count--; |
2280 | } | |
ce5b009c | 2281 | blk_add_rq_to_plug(plug, rq); |
ff3b74b8 | 2282 | trace_block_plug(q); |
2299722c | 2283 | |
dad7a3be | 2284 | if (same_queue_rq) { |
ea4f995e | 2285 | data.hctx = same_queue_rq->mq_hctx; |
ff3b74b8 | 2286 | trace_block_unplug(q, 1, true); |
2299722c | 2287 | blk_mq_try_issue_directly(data.hctx, same_queue_rq, |
fd9c40f6 | 2288 | &cookie); |
dad7a3be | 2289 | } |
a12de1d4 ML |
2290 | } else if ((q->nr_hw_queues > 1 && is_sync) || |
2291 | !data.hctx->dispatch_busy) { | |
105663f7 AA |
2292 | /* |
2293 | * There is no scheduler and we can try to send directly | |
2294 | * to the hardware. | |
2295 | */ | |
fd9c40f6 | 2296 | blk_mq_try_issue_directly(data.hctx, rq, &cookie); |
ab42f35d | 2297 | } else { |
105663f7 | 2298 | /* Default case. */ |
8fa9f556 | 2299 | blk_mq_sched_insert_request(rq, false, true, true); |
ab42f35d | 2300 | } |
320ae51f | 2301 | |
cc29e1bf JX |
2302 | if (!hipri) |
2303 | return BLK_QC_T_NONE; | |
7b371636 | 2304 | return cookie; |
ac7c5675 CH |
2305 | queue_exit: |
2306 | blk_queue_exit(q); | |
2307 | return BLK_QC_T_NONE; | |
320ae51f JA |
2308 | } |
2309 | ||
cc71a6f4 JA |
2310 | void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, |
2311 | unsigned int hctx_idx) | |
95363efd | 2312 | { |
e9b267d9 | 2313 | struct page *page; |
320ae51f | 2314 | |
24d2f903 | 2315 | if (tags->rqs && set->ops->exit_request) { |
e9b267d9 | 2316 | int i; |
320ae51f | 2317 | |
24d2f903 | 2318 | for (i = 0; i < tags->nr_tags; i++) { |
2af8cbe3 JA |
2319 | struct request *rq = tags->static_rqs[i]; |
2320 | ||
2321 | if (!rq) | |
e9b267d9 | 2322 | continue; |
d6296d39 | 2323 | set->ops->exit_request(set, rq, hctx_idx); |
2af8cbe3 | 2324 | tags->static_rqs[i] = NULL; |
e9b267d9 | 2325 | } |
320ae51f | 2326 | } |
320ae51f | 2327 | |
24d2f903 CH |
2328 | while (!list_empty(&tags->page_list)) { |
2329 | page = list_first_entry(&tags->page_list, struct page, lru); | |
6753471c | 2330 | list_del_init(&page->lru); |
f75782e4 CM |
2331 | /* |
2332 | * Remove kmemleak object previously allocated in | |
273938bf | 2333 | * blk_mq_alloc_rqs(). |
f75782e4 CM |
2334 | */ |
2335 | kmemleak_free(page_address(page)); | |
320ae51f JA |
2336 | __free_pages(page, page->private); |
2337 | } | |
cc71a6f4 | 2338 | } |
320ae51f | 2339 | |
1c0706a7 | 2340 | void blk_mq_free_rq_map(struct blk_mq_tags *tags, unsigned int flags) |
cc71a6f4 | 2341 | { |
24d2f903 | 2342 | kfree(tags->rqs); |
cc71a6f4 | 2343 | tags->rqs = NULL; |
2af8cbe3 JA |
2344 | kfree(tags->static_rqs); |
2345 | tags->static_rqs = NULL; | |
320ae51f | 2346 | |
1c0706a7 | 2347 | blk_mq_free_tags(tags, flags); |
320ae51f JA |
2348 | } |
2349 | ||
cc71a6f4 JA |
2350 | struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, |
2351 | unsigned int hctx_idx, | |
2352 | unsigned int nr_tags, | |
1c0706a7 JG |
2353 | unsigned int reserved_tags, |
2354 | unsigned int flags) | |
320ae51f | 2355 | { |
24d2f903 | 2356 | struct blk_mq_tags *tags; |
59f082e4 | 2357 | int node; |
320ae51f | 2358 | |
7d76f856 | 2359 | node = blk_mq_hw_queue_to_node(&set->map[HCTX_TYPE_DEFAULT], hctx_idx); |
59f082e4 SL |
2360 | if (node == NUMA_NO_NODE) |
2361 | node = set->numa_node; | |
2362 | ||
1c0706a7 | 2363 | tags = blk_mq_init_tags(nr_tags, reserved_tags, node, flags); |
24d2f903 CH |
2364 | if (!tags) |
2365 | return NULL; | |
320ae51f | 2366 | |
590b5b7d | 2367 | tags->rqs = kcalloc_node(nr_tags, sizeof(struct request *), |
36e1f3d1 | 2368 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, |
59f082e4 | 2369 | node); |
24d2f903 | 2370 | if (!tags->rqs) { |
1c0706a7 | 2371 | blk_mq_free_tags(tags, flags); |
24d2f903 CH |
2372 | return NULL; |
2373 | } | |
320ae51f | 2374 | |
590b5b7d KC |
2375 | tags->static_rqs = kcalloc_node(nr_tags, sizeof(struct request *), |
2376 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, | |
2377 | node); | |
2af8cbe3 JA |
2378 | if (!tags->static_rqs) { |
2379 | kfree(tags->rqs); | |
1c0706a7 | 2380 | blk_mq_free_tags(tags, flags); |
2af8cbe3 JA |
2381 | return NULL; |
2382 | } | |
2383 | ||
cc71a6f4 JA |
2384 | return tags; |
2385 | } | |
2386 | ||
2387 | static size_t order_to_size(unsigned int order) | |
2388 | { | |
2389 | return (size_t)PAGE_SIZE << order; | |
2390 | } | |
2391 | ||
1d9bd516 TH |
2392 | static int blk_mq_init_request(struct blk_mq_tag_set *set, struct request *rq, |
2393 | unsigned int hctx_idx, int node) | |
2394 | { | |
2395 | int ret; | |
2396 | ||
2397 | if (set->ops->init_request) { | |
2398 | ret = set->ops->init_request(set, rq, hctx_idx, node); | |
2399 | if (ret) | |
2400 | return ret; | |
2401 | } | |
2402 | ||
12f5b931 | 2403 | WRITE_ONCE(rq->state, MQ_RQ_IDLE); |
1d9bd516 TH |
2404 | return 0; |
2405 | } | |
2406 | ||
cc71a6f4 JA |
2407 | int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, |
2408 | unsigned int hctx_idx, unsigned int depth) | |
2409 | { | |
2410 | unsigned int i, j, entries_per_page, max_order = 4; | |
2411 | size_t rq_size, left; | |
59f082e4 SL |
2412 | int node; |
2413 | ||
7d76f856 | 2414 | node = blk_mq_hw_queue_to_node(&set->map[HCTX_TYPE_DEFAULT], hctx_idx); |
59f082e4 SL |
2415 | if (node == NUMA_NO_NODE) |
2416 | node = set->numa_node; | |
cc71a6f4 JA |
2417 | |
2418 | INIT_LIST_HEAD(&tags->page_list); | |
2419 | ||
320ae51f JA |
2420 | /* |
2421 | * rq_size is the size of the request plus driver payload, rounded | |
2422 | * to the cacheline size | |
2423 | */ | |
24d2f903 | 2424 | rq_size = round_up(sizeof(struct request) + set->cmd_size, |
320ae51f | 2425 | cache_line_size()); |
cc71a6f4 | 2426 | left = rq_size * depth; |
320ae51f | 2427 | |
cc71a6f4 | 2428 | for (i = 0; i < depth; ) { |
320ae51f JA |
2429 | int this_order = max_order; |
2430 | struct page *page; | |
2431 | int to_do; | |
2432 | void *p; | |
2433 | ||
b3a834b1 | 2434 | while (this_order && left < order_to_size(this_order - 1)) |
320ae51f JA |
2435 | this_order--; |
2436 | ||
2437 | do { | |
59f082e4 | 2438 | page = alloc_pages_node(node, |
36e1f3d1 | 2439 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO, |
a5164405 | 2440 | this_order); |
320ae51f JA |
2441 | if (page) |
2442 | break; | |
2443 | if (!this_order--) | |
2444 | break; | |
2445 | if (order_to_size(this_order) < rq_size) | |
2446 | break; | |
2447 | } while (1); | |
2448 | ||
2449 | if (!page) | |
24d2f903 | 2450 | goto fail; |
320ae51f JA |
2451 | |
2452 | page->private = this_order; | |
24d2f903 | 2453 | list_add_tail(&page->lru, &tags->page_list); |
320ae51f JA |
2454 | |
2455 | p = page_address(page); | |
f75782e4 CM |
2456 | /* |
2457 | * Allow kmemleak to scan these pages as they contain pointers | |
2458 | * to additional allocations like via ops->init_request(). | |
2459 | */ | |
36e1f3d1 | 2460 | kmemleak_alloc(p, order_to_size(this_order), 1, GFP_NOIO); |
320ae51f | 2461 | entries_per_page = order_to_size(this_order) / rq_size; |
cc71a6f4 | 2462 | to_do = min(entries_per_page, depth - i); |
320ae51f JA |
2463 | left -= to_do * rq_size; |
2464 | for (j = 0; j < to_do; j++) { | |
2af8cbe3 JA |
2465 | struct request *rq = p; |
2466 | ||
2467 | tags->static_rqs[i] = rq; | |
1d9bd516 TH |
2468 | if (blk_mq_init_request(set, rq, hctx_idx, node)) { |
2469 | tags->static_rqs[i] = NULL; | |
2470 | goto fail; | |
e9b267d9 CH |
2471 | } |
2472 | ||
320ae51f JA |
2473 | p += rq_size; |
2474 | i++; | |
2475 | } | |
2476 | } | |
cc71a6f4 | 2477 | return 0; |
320ae51f | 2478 | |
24d2f903 | 2479 | fail: |
cc71a6f4 JA |
2480 | blk_mq_free_rqs(set, tags, hctx_idx); |
2481 | return -ENOMEM; | |
320ae51f JA |
2482 | } |
2483 | ||
bf0beec0 ML |
2484 | struct rq_iter_data { |
2485 | struct blk_mq_hw_ctx *hctx; | |
2486 | bool has_rq; | |
2487 | }; | |
2488 | ||
2489 | static bool blk_mq_has_request(struct request *rq, void *data, bool reserved) | |
2490 | { | |
2491 | struct rq_iter_data *iter_data = data; | |
2492 | ||
2493 | if (rq->mq_hctx != iter_data->hctx) | |
2494 | return true; | |
2495 | iter_data->has_rq = true; | |
2496 | return false; | |
2497 | } | |
2498 | ||
2499 | static bool blk_mq_hctx_has_requests(struct blk_mq_hw_ctx *hctx) | |
2500 | { | |
2501 | struct blk_mq_tags *tags = hctx->sched_tags ? | |
2502 | hctx->sched_tags : hctx->tags; | |
2503 | struct rq_iter_data data = { | |
2504 | .hctx = hctx, | |
2505 | }; | |
2506 | ||
2507 | blk_mq_all_tag_iter(tags, blk_mq_has_request, &data); | |
2508 | return data.has_rq; | |
2509 | } | |
2510 | ||
2511 | static inline bool blk_mq_last_cpu_in_hctx(unsigned int cpu, | |
2512 | struct blk_mq_hw_ctx *hctx) | |
2513 | { | |
2514 | if (cpumask_next_and(-1, hctx->cpumask, cpu_online_mask) != cpu) | |
2515 | return false; | |
2516 | if (cpumask_next_and(cpu, hctx->cpumask, cpu_online_mask) < nr_cpu_ids) | |
2517 | return false; | |
2518 | return true; | |
2519 | } | |
2520 | ||
2521 | static int blk_mq_hctx_notify_offline(unsigned int cpu, struct hlist_node *node) | |
2522 | { | |
2523 | struct blk_mq_hw_ctx *hctx = hlist_entry_safe(node, | |
2524 | struct blk_mq_hw_ctx, cpuhp_online); | |
2525 | ||
2526 | if (!cpumask_test_cpu(cpu, hctx->cpumask) || | |
2527 | !blk_mq_last_cpu_in_hctx(cpu, hctx)) | |
2528 | return 0; | |
2529 | ||
2530 | /* | |
2531 | * Prevent new request from being allocated on the current hctx. | |
2532 | * | |
2533 | * The smp_mb__after_atomic() Pairs with the implied barrier in | |
2534 | * test_and_set_bit_lock in sbitmap_get(). Ensures the inactive flag is | |
2535 | * seen once we return from the tag allocator. | |
2536 | */ | |
2537 | set_bit(BLK_MQ_S_INACTIVE, &hctx->state); | |
2538 | smp_mb__after_atomic(); | |
2539 | ||
2540 | /* | |
2541 | * Try to grab a reference to the queue and wait for any outstanding | |
2542 | * requests. If we could not grab a reference the queue has been | |
2543 | * frozen and there are no requests. | |
2544 | */ | |
2545 | if (percpu_ref_tryget(&hctx->queue->q_usage_counter)) { | |
2546 | while (blk_mq_hctx_has_requests(hctx)) | |
2547 | msleep(5); | |
2548 | percpu_ref_put(&hctx->queue->q_usage_counter); | |
2549 | } | |
2550 | ||
2551 | return 0; | |
2552 | } | |
2553 | ||
2554 | static int blk_mq_hctx_notify_online(unsigned int cpu, struct hlist_node *node) | |
2555 | { | |
2556 | struct blk_mq_hw_ctx *hctx = hlist_entry_safe(node, | |
2557 | struct blk_mq_hw_ctx, cpuhp_online); | |
2558 | ||
2559 | if (cpumask_test_cpu(cpu, hctx->cpumask)) | |
2560 | clear_bit(BLK_MQ_S_INACTIVE, &hctx->state); | |
2561 | return 0; | |
2562 | } | |
2563 | ||
e57690fe JA |
2564 | /* |
2565 | * 'cpu' is going away. splice any existing rq_list entries from this | |
2566 | * software queue to the hw queue dispatch list, and ensure that it | |
2567 | * gets run. | |
2568 | */ | |
9467f859 | 2569 | static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node) |
484b4061 | 2570 | { |
9467f859 | 2571 | struct blk_mq_hw_ctx *hctx; |
484b4061 JA |
2572 | struct blk_mq_ctx *ctx; |
2573 | LIST_HEAD(tmp); | |
c16d6b5a | 2574 | enum hctx_type type; |
484b4061 | 2575 | |
9467f859 | 2576 | hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_dead); |
bf0beec0 ML |
2577 | if (!cpumask_test_cpu(cpu, hctx->cpumask)) |
2578 | return 0; | |
2579 | ||
e57690fe | 2580 | ctx = __blk_mq_get_ctx(hctx->queue, cpu); |
c16d6b5a | 2581 | type = hctx->type; |
484b4061 JA |
2582 | |
2583 | spin_lock(&ctx->lock); | |
c16d6b5a ML |
2584 | if (!list_empty(&ctx->rq_lists[type])) { |
2585 | list_splice_init(&ctx->rq_lists[type], &tmp); | |
484b4061 JA |
2586 | blk_mq_hctx_clear_pending(hctx, ctx); |
2587 | } | |
2588 | spin_unlock(&ctx->lock); | |
2589 | ||
2590 | if (list_empty(&tmp)) | |
9467f859 | 2591 | return 0; |
484b4061 | 2592 | |
e57690fe JA |
2593 | spin_lock(&hctx->lock); |
2594 | list_splice_tail_init(&tmp, &hctx->dispatch); | |
2595 | spin_unlock(&hctx->lock); | |
484b4061 JA |
2596 | |
2597 | blk_mq_run_hw_queue(hctx, true); | |
9467f859 | 2598 | return 0; |
484b4061 JA |
2599 | } |
2600 | ||
9467f859 | 2601 | static void blk_mq_remove_cpuhp(struct blk_mq_hw_ctx *hctx) |
484b4061 | 2602 | { |
bf0beec0 ML |
2603 | if (!(hctx->flags & BLK_MQ_F_STACKING)) |
2604 | cpuhp_state_remove_instance_nocalls(CPUHP_AP_BLK_MQ_ONLINE, | |
2605 | &hctx->cpuhp_online); | |
9467f859 TG |
2606 | cpuhp_state_remove_instance_nocalls(CPUHP_BLK_MQ_DEAD, |
2607 | &hctx->cpuhp_dead); | |
484b4061 JA |
2608 | } |
2609 | ||
c3b4afca | 2610 | /* hctx->ctxs will be freed in queue's release handler */ |
08e98fc6 ML |
2611 | static void blk_mq_exit_hctx(struct request_queue *q, |
2612 | struct blk_mq_tag_set *set, | |
2613 | struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) | |
2614 | { | |
8ab0b7dc ML |
2615 | if (blk_mq_hw_queue_mapped(hctx)) |
2616 | blk_mq_tag_idle(hctx); | |
08e98fc6 | 2617 | |
f70ced09 | 2618 | if (set->ops->exit_request) |
d6296d39 | 2619 | set->ops->exit_request(set, hctx->fq->flush_rq, hctx_idx); |
f70ced09 | 2620 | |
08e98fc6 ML |
2621 | if (set->ops->exit_hctx) |
2622 | set->ops->exit_hctx(hctx, hctx_idx); | |
2623 | ||
9467f859 | 2624 | blk_mq_remove_cpuhp(hctx); |
2f8f1336 ML |
2625 | |
2626 | spin_lock(&q->unused_hctx_lock); | |
2627 | list_add(&hctx->hctx_list, &q->unused_hctx_list); | |
2628 | spin_unlock(&q->unused_hctx_lock); | |
08e98fc6 ML |
2629 | } |
2630 | ||
624dbe47 ML |
2631 | static void blk_mq_exit_hw_queues(struct request_queue *q, |
2632 | struct blk_mq_tag_set *set, int nr_queue) | |
2633 | { | |
2634 | struct blk_mq_hw_ctx *hctx; | |
2635 | unsigned int i; | |
2636 | ||
2637 | queue_for_each_hw_ctx(q, hctx, i) { | |
2638 | if (i == nr_queue) | |
2639 | break; | |
477e19de | 2640 | blk_mq_debugfs_unregister_hctx(hctx); |
08e98fc6 | 2641 | blk_mq_exit_hctx(q, set, hctx, i); |
624dbe47 | 2642 | } |
624dbe47 ML |
2643 | } |
2644 | ||
7c6c5b7c ML |
2645 | static int blk_mq_hw_ctx_size(struct blk_mq_tag_set *tag_set) |
2646 | { | |
2647 | int hw_ctx_size = sizeof(struct blk_mq_hw_ctx); | |
2648 | ||
2649 | BUILD_BUG_ON(ALIGN(offsetof(struct blk_mq_hw_ctx, srcu), | |
2650 | __alignof__(struct blk_mq_hw_ctx)) != | |
2651 | sizeof(struct blk_mq_hw_ctx)); | |
2652 | ||
2653 | if (tag_set->flags & BLK_MQ_F_BLOCKING) | |
2654 | hw_ctx_size += sizeof(struct srcu_struct); | |
2655 | ||
2656 | return hw_ctx_size; | |
2657 | } | |
2658 | ||
08e98fc6 ML |
2659 | static int blk_mq_init_hctx(struct request_queue *q, |
2660 | struct blk_mq_tag_set *set, | |
2661 | struct blk_mq_hw_ctx *hctx, unsigned hctx_idx) | |
320ae51f | 2662 | { |
7c6c5b7c ML |
2663 | hctx->queue_num = hctx_idx; |
2664 | ||
bf0beec0 ML |
2665 | if (!(hctx->flags & BLK_MQ_F_STACKING)) |
2666 | cpuhp_state_add_instance_nocalls(CPUHP_AP_BLK_MQ_ONLINE, | |
2667 | &hctx->cpuhp_online); | |
7c6c5b7c ML |
2668 | cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, &hctx->cpuhp_dead); |
2669 | ||
2670 | hctx->tags = set->tags[hctx_idx]; | |
2671 | ||
2672 | if (set->ops->init_hctx && | |
2673 | set->ops->init_hctx(hctx, set->driver_data, hctx_idx)) | |
2674 | goto unregister_cpu_notifier; | |
08e98fc6 | 2675 | |
7c6c5b7c ML |
2676 | if (blk_mq_init_request(set, hctx->fq->flush_rq, hctx_idx, |
2677 | hctx->numa_node)) | |
2678 | goto exit_hctx; | |
2679 | return 0; | |
2680 | ||
2681 | exit_hctx: | |
2682 | if (set->ops->exit_hctx) | |
2683 | set->ops->exit_hctx(hctx, hctx_idx); | |
2684 | unregister_cpu_notifier: | |
2685 | blk_mq_remove_cpuhp(hctx); | |
2686 | return -1; | |
2687 | } | |
2688 | ||
2689 | static struct blk_mq_hw_ctx * | |
2690 | blk_mq_alloc_hctx(struct request_queue *q, struct blk_mq_tag_set *set, | |
2691 | int node) | |
2692 | { | |
2693 | struct blk_mq_hw_ctx *hctx; | |
2694 | gfp_t gfp = GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY; | |
2695 | ||
2696 | hctx = kzalloc_node(blk_mq_hw_ctx_size(set), gfp, node); | |
2697 | if (!hctx) | |
2698 | goto fail_alloc_hctx; | |
2699 | ||
2700 | if (!zalloc_cpumask_var_node(&hctx->cpumask, gfp, node)) | |
2701 | goto free_hctx; | |
2702 | ||
2703 | atomic_set(&hctx->nr_active, 0); | |
08e98fc6 | 2704 | if (node == NUMA_NO_NODE) |
7c6c5b7c ML |
2705 | node = set->numa_node; |
2706 | hctx->numa_node = node; | |
08e98fc6 | 2707 | |
9f993737 | 2708 | INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn); |
08e98fc6 ML |
2709 | spin_lock_init(&hctx->lock); |
2710 | INIT_LIST_HEAD(&hctx->dispatch); | |
2711 | hctx->queue = q; | |
51db1c37 | 2712 | hctx->flags = set->flags & ~BLK_MQ_F_TAG_QUEUE_SHARED; |
08e98fc6 | 2713 | |
2f8f1336 ML |
2714 | INIT_LIST_HEAD(&hctx->hctx_list); |
2715 | ||
320ae51f | 2716 | /* |
08e98fc6 ML |
2717 | * Allocate space for all possible cpus to avoid allocation at |
2718 | * runtime | |
320ae51f | 2719 | */ |
d904bfa7 | 2720 | hctx->ctxs = kmalloc_array_node(nr_cpu_ids, sizeof(void *), |
7c6c5b7c | 2721 | gfp, node); |
08e98fc6 | 2722 | if (!hctx->ctxs) |
7c6c5b7c | 2723 | goto free_cpumask; |
320ae51f | 2724 | |
5b202853 | 2725 | if (sbitmap_init_node(&hctx->ctx_map, nr_cpu_ids, ilog2(8), |
c548e62b | 2726 | gfp, node, false, false)) |
08e98fc6 | 2727 | goto free_ctxs; |
08e98fc6 | 2728 | hctx->nr_ctx = 0; |
320ae51f | 2729 | |
5815839b | 2730 | spin_lock_init(&hctx->dispatch_wait_lock); |
eb619fdb JA |
2731 | init_waitqueue_func_entry(&hctx->dispatch_wait, blk_mq_dispatch_wake); |
2732 | INIT_LIST_HEAD(&hctx->dispatch_wait.entry); | |
2733 | ||
754a1572 | 2734 | hctx->fq = blk_alloc_flush_queue(hctx->numa_node, set->cmd_size, gfp); |
f70ced09 | 2735 | if (!hctx->fq) |
7c6c5b7c | 2736 | goto free_bitmap; |
320ae51f | 2737 | |
6a83e74d | 2738 | if (hctx->flags & BLK_MQ_F_BLOCKING) |
05707b64 | 2739 | init_srcu_struct(hctx->srcu); |
7c6c5b7c | 2740 | blk_mq_hctx_kobj_init(hctx); |
6a83e74d | 2741 | |
7c6c5b7c | 2742 | return hctx; |
320ae51f | 2743 | |
08e98fc6 | 2744 | free_bitmap: |
88459642 | 2745 | sbitmap_free(&hctx->ctx_map); |
08e98fc6 ML |
2746 | free_ctxs: |
2747 | kfree(hctx->ctxs); | |
7c6c5b7c ML |
2748 | free_cpumask: |
2749 | free_cpumask_var(hctx->cpumask); | |
2750 | free_hctx: | |
2751 | kfree(hctx); | |
2752 | fail_alloc_hctx: | |
2753 | return NULL; | |
08e98fc6 | 2754 | } |
320ae51f | 2755 | |
320ae51f JA |
2756 | static void blk_mq_init_cpu_queues(struct request_queue *q, |
2757 | unsigned int nr_hw_queues) | |
2758 | { | |
b3c661b1 JA |
2759 | struct blk_mq_tag_set *set = q->tag_set; |
2760 | unsigned int i, j; | |
320ae51f JA |
2761 | |
2762 | for_each_possible_cpu(i) { | |
2763 | struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i); | |
2764 | struct blk_mq_hw_ctx *hctx; | |
c16d6b5a | 2765 | int k; |
320ae51f | 2766 | |
320ae51f JA |
2767 | __ctx->cpu = i; |
2768 | spin_lock_init(&__ctx->lock); | |
c16d6b5a ML |
2769 | for (k = HCTX_TYPE_DEFAULT; k < HCTX_MAX_TYPES; k++) |
2770 | INIT_LIST_HEAD(&__ctx->rq_lists[k]); | |
2771 | ||
320ae51f JA |
2772 | __ctx->queue = q; |
2773 | ||
320ae51f JA |
2774 | /* |
2775 | * Set local node, IFF we have more than one hw queue. If | |
2776 | * not, we remain on the home node of the device | |
2777 | */ | |
b3c661b1 JA |
2778 | for (j = 0; j < set->nr_maps; j++) { |
2779 | hctx = blk_mq_map_queue_type(q, j, i); | |
2780 | if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE) | |
576e85c5 | 2781 | hctx->numa_node = cpu_to_node(i); |
b3c661b1 | 2782 | } |
320ae51f JA |
2783 | } |
2784 | } | |
2785 | ||
03b63b02 WZ |
2786 | static bool __blk_mq_alloc_map_and_request(struct blk_mq_tag_set *set, |
2787 | int hctx_idx) | |
cc71a6f4 | 2788 | { |
1c0706a7 | 2789 | unsigned int flags = set->flags; |
cc71a6f4 JA |
2790 | int ret = 0; |
2791 | ||
2792 | set->tags[hctx_idx] = blk_mq_alloc_rq_map(set, hctx_idx, | |
1c0706a7 | 2793 | set->queue_depth, set->reserved_tags, flags); |
cc71a6f4 JA |
2794 | if (!set->tags[hctx_idx]) |
2795 | return false; | |
2796 | ||
2797 | ret = blk_mq_alloc_rqs(set, set->tags[hctx_idx], hctx_idx, | |
2798 | set->queue_depth); | |
2799 | if (!ret) | |
2800 | return true; | |
2801 | ||
1c0706a7 | 2802 | blk_mq_free_rq_map(set->tags[hctx_idx], flags); |
cc71a6f4 JA |
2803 | set->tags[hctx_idx] = NULL; |
2804 | return false; | |
2805 | } | |
2806 | ||
2807 | static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set, | |
2808 | unsigned int hctx_idx) | |
2809 | { | |
1c0706a7 JG |
2810 | unsigned int flags = set->flags; |
2811 | ||
4e6db0f2 | 2812 | if (set->tags && set->tags[hctx_idx]) { |
bd166ef1 | 2813 | blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx); |
1c0706a7 | 2814 | blk_mq_free_rq_map(set->tags[hctx_idx], flags); |
bd166ef1 JA |
2815 | set->tags[hctx_idx] = NULL; |
2816 | } | |
cc71a6f4 JA |
2817 | } |
2818 | ||
4b855ad3 | 2819 | static void blk_mq_map_swqueue(struct request_queue *q) |
320ae51f | 2820 | { |
b3c661b1 | 2821 | unsigned int i, j, hctx_idx; |
320ae51f JA |
2822 | struct blk_mq_hw_ctx *hctx; |
2823 | struct blk_mq_ctx *ctx; | |
2a34c087 | 2824 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f JA |
2825 | |
2826 | queue_for_each_hw_ctx(q, hctx, i) { | |
e4043dcf | 2827 | cpumask_clear(hctx->cpumask); |
320ae51f | 2828 | hctx->nr_ctx = 0; |
d416c92c | 2829 | hctx->dispatch_from = NULL; |
320ae51f JA |
2830 | } |
2831 | ||
2832 | /* | |
4b855ad3 | 2833 | * Map software to hardware queues. |
4412efec ML |
2834 | * |
2835 | * If the cpu isn't present, the cpu is mapped to first hctx. | |
320ae51f | 2836 | */ |
20e4d813 | 2837 | for_each_possible_cpu(i) { |
4412efec | 2838 | |
897bb0c7 | 2839 | ctx = per_cpu_ptr(q->queue_ctx, i); |
b3c661b1 | 2840 | for (j = 0; j < set->nr_maps; j++) { |
bb94aea1 JW |
2841 | if (!set->map[j].nr_queues) { |
2842 | ctx->hctxs[j] = blk_mq_map_queue_type(q, | |
2843 | HCTX_TYPE_DEFAULT, i); | |
e5edd5f2 | 2844 | continue; |
bb94aea1 | 2845 | } |
fd689871 ML |
2846 | hctx_idx = set->map[j].mq_map[i]; |
2847 | /* unmapped hw queue can be remapped after CPU topo changed */ | |
2848 | if (!set->tags[hctx_idx] && | |
03b63b02 | 2849 | !__blk_mq_alloc_map_and_request(set, hctx_idx)) { |
fd689871 ML |
2850 | /* |
2851 | * If tags initialization fail for some hctx, | |
2852 | * that hctx won't be brought online. In this | |
2853 | * case, remap the current ctx to hctx[0] which | |
2854 | * is guaranteed to always have tags allocated | |
2855 | */ | |
2856 | set->map[j].mq_map[i] = 0; | |
2857 | } | |
e5edd5f2 | 2858 | |
b3c661b1 | 2859 | hctx = blk_mq_map_queue_type(q, j, i); |
8ccdf4a3 | 2860 | ctx->hctxs[j] = hctx; |
b3c661b1 JA |
2861 | /* |
2862 | * If the CPU is already set in the mask, then we've | |
2863 | * mapped this one already. This can happen if | |
2864 | * devices share queues across queue maps. | |
2865 | */ | |
2866 | if (cpumask_test_cpu(i, hctx->cpumask)) | |
2867 | continue; | |
2868 | ||
2869 | cpumask_set_cpu(i, hctx->cpumask); | |
2870 | hctx->type = j; | |
2871 | ctx->index_hw[hctx->type] = hctx->nr_ctx; | |
2872 | hctx->ctxs[hctx->nr_ctx++] = ctx; | |
2873 | ||
2874 | /* | |
2875 | * If the nr_ctx type overflows, we have exceeded the | |
2876 | * amount of sw queues we can support. | |
2877 | */ | |
2878 | BUG_ON(!hctx->nr_ctx); | |
2879 | } | |
bb94aea1 JW |
2880 | |
2881 | for (; j < HCTX_MAX_TYPES; j++) | |
2882 | ctx->hctxs[j] = blk_mq_map_queue_type(q, | |
2883 | HCTX_TYPE_DEFAULT, i); | |
320ae51f | 2884 | } |
506e931f JA |
2885 | |
2886 | queue_for_each_hw_ctx(q, hctx, i) { | |
4412efec ML |
2887 | /* |
2888 | * If no software queues are mapped to this hardware queue, | |
2889 | * disable it and free the request entries. | |
2890 | */ | |
2891 | if (!hctx->nr_ctx) { | |
2892 | /* Never unmap queue 0. We need it as a | |
2893 | * fallback in case of a new remap fails | |
2894 | * allocation | |
2895 | */ | |
2896 | if (i && set->tags[i]) | |
2897 | blk_mq_free_map_and_requests(set, i); | |
2898 | ||
2899 | hctx->tags = NULL; | |
2900 | continue; | |
2901 | } | |
484b4061 | 2902 | |
2a34c087 ML |
2903 | hctx->tags = set->tags[i]; |
2904 | WARN_ON(!hctx->tags); | |
2905 | ||
889fa31f CY |
2906 | /* |
2907 | * Set the map size to the number of mapped software queues. | |
2908 | * This is more accurate and more efficient than looping | |
2909 | * over all possibly mapped software queues. | |
2910 | */ | |
88459642 | 2911 | sbitmap_resize(&hctx->ctx_map, hctx->nr_ctx); |
889fa31f | 2912 | |
484b4061 JA |
2913 | /* |
2914 | * Initialize batch roundrobin counts | |
2915 | */ | |
f82ddf19 | 2916 | hctx->next_cpu = blk_mq_first_mapped_cpu(hctx); |
506e931f JA |
2917 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; |
2918 | } | |
320ae51f JA |
2919 | } |
2920 | ||
8e8320c9 JA |
2921 | /* |
2922 | * Caller needs to ensure that we're either frozen/quiesced, or that | |
2923 | * the queue isn't live yet. | |
2924 | */ | |
2404e607 | 2925 | static void queue_set_hctx_shared(struct request_queue *q, bool shared) |
0d2602ca JA |
2926 | { |
2927 | struct blk_mq_hw_ctx *hctx; | |
0d2602ca JA |
2928 | int i; |
2929 | ||
2404e607 | 2930 | queue_for_each_hw_ctx(q, hctx, i) { |
97889f9a | 2931 | if (shared) |
51db1c37 | 2932 | hctx->flags |= BLK_MQ_F_TAG_QUEUE_SHARED; |
97889f9a | 2933 | else |
51db1c37 | 2934 | hctx->flags &= ~BLK_MQ_F_TAG_QUEUE_SHARED; |
2404e607 JM |
2935 | } |
2936 | } | |
2937 | ||
655ac300 HR |
2938 | static void blk_mq_update_tag_set_shared(struct blk_mq_tag_set *set, |
2939 | bool shared) | |
2404e607 JM |
2940 | { |
2941 | struct request_queue *q; | |
0d2602ca | 2942 | |
705cda97 BVA |
2943 | lockdep_assert_held(&set->tag_list_lock); |
2944 | ||
0d2602ca JA |
2945 | list_for_each_entry(q, &set->tag_list, tag_set_list) { |
2946 | blk_mq_freeze_queue(q); | |
2404e607 | 2947 | queue_set_hctx_shared(q, shared); |
0d2602ca JA |
2948 | blk_mq_unfreeze_queue(q); |
2949 | } | |
2950 | } | |
2951 | ||
2952 | static void blk_mq_del_queue_tag_set(struct request_queue *q) | |
2953 | { | |
2954 | struct blk_mq_tag_set *set = q->tag_set; | |
2955 | ||
0d2602ca | 2956 | mutex_lock(&set->tag_list_lock); |
08c875cb | 2957 | list_del(&q->tag_set_list); |
2404e607 JM |
2958 | if (list_is_singular(&set->tag_list)) { |
2959 | /* just transitioned to unshared */ | |
51db1c37 | 2960 | set->flags &= ~BLK_MQ_F_TAG_QUEUE_SHARED; |
2404e607 | 2961 | /* update existing queue */ |
655ac300 | 2962 | blk_mq_update_tag_set_shared(set, false); |
2404e607 | 2963 | } |
0d2602ca | 2964 | mutex_unlock(&set->tag_list_lock); |
a347c7ad | 2965 | INIT_LIST_HEAD(&q->tag_set_list); |
0d2602ca JA |
2966 | } |
2967 | ||
2968 | static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, | |
2969 | struct request_queue *q) | |
2970 | { | |
0d2602ca | 2971 | mutex_lock(&set->tag_list_lock); |
2404e607 | 2972 | |
ff821d27 JA |
2973 | /* |
2974 | * Check to see if we're transitioning to shared (from 1 to 2 queues). | |
2975 | */ | |
2976 | if (!list_empty(&set->tag_list) && | |
51db1c37 ML |
2977 | !(set->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) { |
2978 | set->flags |= BLK_MQ_F_TAG_QUEUE_SHARED; | |
2404e607 | 2979 | /* update existing queue */ |
655ac300 | 2980 | blk_mq_update_tag_set_shared(set, true); |
2404e607 | 2981 | } |
51db1c37 | 2982 | if (set->flags & BLK_MQ_F_TAG_QUEUE_SHARED) |
2404e607 | 2983 | queue_set_hctx_shared(q, true); |
08c875cb | 2984 | list_add_tail(&q->tag_set_list, &set->tag_list); |
2404e607 | 2985 | |
0d2602ca JA |
2986 | mutex_unlock(&set->tag_list_lock); |
2987 | } | |
2988 | ||
1db4909e ML |
2989 | /* All allocations will be freed in release handler of q->mq_kobj */ |
2990 | static int blk_mq_alloc_ctxs(struct request_queue *q) | |
2991 | { | |
2992 | struct blk_mq_ctxs *ctxs; | |
2993 | int cpu; | |
2994 | ||
2995 | ctxs = kzalloc(sizeof(*ctxs), GFP_KERNEL); | |
2996 | if (!ctxs) | |
2997 | return -ENOMEM; | |
2998 | ||
2999 | ctxs->queue_ctx = alloc_percpu(struct blk_mq_ctx); | |
3000 | if (!ctxs->queue_ctx) | |
3001 | goto fail; | |
3002 | ||
3003 | for_each_possible_cpu(cpu) { | |
3004 | struct blk_mq_ctx *ctx = per_cpu_ptr(ctxs->queue_ctx, cpu); | |
3005 | ctx->ctxs = ctxs; | |
3006 | } | |
3007 | ||
3008 | q->mq_kobj = &ctxs->kobj; | |
3009 | q->queue_ctx = ctxs->queue_ctx; | |
3010 | ||
3011 | return 0; | |
3012 | fail: | |
3013 | kfree(ctxs); | |
3014 | return -ENOMEM; | |
3015 | } | |
3016 | ||
e09aae7e ML |
3017 | /* |
3018 | * It is the actual release handler for mq, but we do it from | |
3019 | * request queue's release handler for avoiding use-after-free | |
3020 | * and headache because q->mq_kobj shouldn't have been introduced, | |
3021 | * but we can't group ctx/kctx kobj without it. | |
3022 | */ | |
3023 | void blk_mq_release(struct request_queue *q) | |
3024 | { | |
2f8f1336 ML |
3025 | struct blk_mq_hw_ctx *hctx, *next; |
3026 | int i; | |
e09aae7e | 3027 | |
2f8f1336 ML |
3028 | queue_for_each_hw_ctx(q, hctx, i) |
3029 | WARN_ON_ONCE(hctx && list_empty(&hctx->hctx_list)); | |
3030 | ||
3031 | /* all hctx are in .unused_hctx_list now */ | |
3032 | list_for_each_entry_safe(hctx, next, &q->unused_hctx_list, hctx_list) { | |
3033 | list_del_init(&hctx->hctx_list); | |
6c8b232e | 3034 | kobject_put(&hctx->kobj); |
c3b4afca | 3035 | } |
e09aae7e ML |
3036 | |
3037 | kfree(q->queue_hw_ctx); | |
3038 | ||
7ea5fe31 ML |
3039 | /* |
3040 | * release .mq_kobj and sw queue's kobject now because | |
3041 | * both share lifetime with request queue. | |
3042 | */ | |
3043 | blk_mq_sysfs_deinit(q); | |
e09aae7e ML |
3044 | } |
3045 | ||
2f227bb9 CH |
3046 | struct request_queue *blk_mq_init_queue_data(struct blk_mq_tag_set *set, |
3047 | void *queuedata) | |
b62c21b7 MS |
3048 | { |
3049 | struct request_queue *uninit_q, *q; | |
3050 | ||
c62b37d9 | 3051 | uninit_q = blk_alloc_queue(set->numa_node); |
b62c21b7 MS |
3052 | if (!uninit_q) |
3053 | return ERR_PTR(-ENOMEM); | |
2f227bb9 | 3054 | uninit_q->queuedata = queuedata; |
b62c21b7 | 3055 | |
737eb78e DLM |
3056 | /* |
3057 | * Initialize the queue without an elevator. device_add_disk() will do | |
3058 | * the initialization. | |
3059 | */ | |
3060 | q = blk_mq_init_allocated_queue(set, uninit_q, false); | |
b62c21b7 MS |
3061 | if (IS_ERR(q)) |
3062 | blk_cleanup_queue(uninit_q); | |
3063 | ||
3064 | return q; | |
3065 | } | |
2f227bb9 CH |
3066 | EXPORT_SYMBOL_GPL(blk_mq_init_queue_data); |
3067 | ||
3068 | struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) | |
3069 | { | |
3070 | return blk_mq_init_queue_data(set, NULL); | |
3071 | } | |
b62c21b7 MS |
3072 | EXPORT_SYMBOL(blk_mq_init_queue); |
3073 | ||
9316a9ed JA |
3074 | /* |
3075 | * Helper for setting up a queue with mq ops, given queue depth, and | |
3076 | * the passed in mq ops flags. | |
3077 | */ | |
3078 | struct request_queue *blk_mq_init_sq_queue(struct blk_mq_tag_set *set, | |
3079 | const struct blk_mq_ops *ops, | |
3080 | unsigned int queue_depth, | |
3081 | unsigned int set_flags) | |
3082 | { | |
3083 | struct request_queue *q; | |
3084 | int ret; | |
3085 | ||
3086 | memset(set, 0, sizeof(*set)); | |
3087 | set->ops = ops; | |
3088 | set->nr_hw_queues = 1; | |
b3c661b1 | 3089 | set->nr_maps = 1; |
9316a9ed JA |
3090 | set->queue_depth = queue_depth; |
3091 | set->numa_node = NUMA_NO_NODE; | |
3092 | set->flags = set_flags; | |
3093 | ||
3094 | ret = blk_mq_alloc_tag_set(set); | |
3095 | if (ret) | |
3096 | return ERR_PTR(ret); | |
3097 | ||
3098 | q = blk_mq_init_queue(set); | |
3099 | if (IS_ERR(q)) { | |
3100 | blk_mq_free_tag_set(set); | |
3101 | return q; | |
3102 | } | |
3103 | ||
3104 | return q; | |
3105 | } | |
3106 | EXPORT_SYMBOL(blk_mq_init_sq_queue); | |
3107 | ||
34d11ffa JW |
3108 | static struct blk_mq_hw_ctx *blk_mq_alloc_and_init_hctx( |
3109 | struct blk_mq_tag_set *set, struct request_queue *q, | |
3110 | int hctx_idx, int node) | |
3111 | { | |
2f8f1336 | 3112 | struct blk_mq_hw_ctx *hctx = NULL, *tmp; |
34d11ffa | 3113 | |
2f8f1336 ML |
3114 | /* reuse dead hctx first */ |
3115 | spin_lock(&q->unused_hctx_lock); | |
3116 | list_for_each_entry(tmp, &q->unused_hctx_list, hctx_list) { | |
3117 | if (tmp->numa_node == node) { | |
3118 | hctx = tmp; | |
3119 | break; | |
3120 | } | |
3121 | } | |
3122 | if (hctx) | |
3123 | list_del_init(&hctx->hctx_list); | |
3124 | spin_unlock(&q->unused_hctx_lock); | |
3125 | ||
3126 | if (!hctx) | |
3127 | hctx = blk_mq_alloc_hctx(q, set, node); | |
34d11ffa | 3128 | if (!hctx) |
7c6c5b7c | 3129 | goto fail; |
34d11ffa | 3130 | |
7c6c5b7c ML |
3131 | if (blk_mq_init_hctx(q, set, hctx, hctx_idx)) |
3132 | goto free_hctx; | |
34d11ffa JW |
3133 | |
3134 | return hctx; | |
7c6c5b7c ML |
3135 | |
3136 | free_hctx: | |
3137 | kobject_put(&hctx->kobj); | |
3138 | fail: | |
3139 | return NULL; | |
34d11ffa JW |
3140 | } |
3141 | ||
868f2f0b KB |
3142 | static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, |
3143 | struct request_queue *q) | |
320ae51f | 3144 | { |
e01ad46d | 3145 | int i, j, end; |
868f2f0b | 3146 | struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx; |
f14bbe77 | 3147 | |
ac0d6b92 BVA |
3148 | if (q->nr_hw_queues < set->nr_hw_queues) { |
3149 | struct blk_mq_hw_ctx **new_hctxs; | |
3150 | ||
3151 | new_hctxs = kcalloc_node(set->nr_hw_queues, | |
3152 | sizeof(*new_hctxs), GFP_KERNEL, | |
3153 | set->numa_node); | |
3154 | if (!new_hctxs) | |
3155 | return; | |
3156 | if (hctxs) | |
3157 | memcpy(new_hctxs, hctxs, q->nr_hw_queues * | |
3158 | sizeof(*hctxs)); | |
3159 | q->queue_hw_ctx = new_hctxs; | |
ac0d6b92 BVA |
3160 | kfree(hctxs); |
3161 | hctxs = new_hctxs; | |
3162 | } | |
3163 | ||
fb350e0a ML |
3164 | /* protect against switching io scheduler */ |
3165 | mutex_lock(&q->sysfs_lock); | |
24d2f903 | 3166 | for (i = 0; i < set->nr_hw_queues; i++) { |
868f2f0b | 3167 | int node; |
34d11ffa | 3168 | struct blk_mq_hw_ctx *hctx; |
868f2f0b | 3169 | |
7d76f856 | 3170 | node = blk_mq_hw_queue_to_node(&set->map[HCTX_TYPE_DEFAULT], i); |
34d11ffa JW |
3171 | /* |
3172 | * If the hw queue has been mapped to another numa node, | |
3173 | * we need to realloc the hctx. If allocation fails, fallback | |
3174 | * to use the previous one. | |
3175 | */ | |
3176 | if (hctxs[i] && (hctxs[i]->numa_node == node)) | |
3177 | continue; | |
868f2f0b | 3178 | |
34d11ffa JW |
3179 | hctx = blk_mq_alloc_and_init_hctx(set, q, i, node); |
3180 | if (hctx) { | |
2f8f1336 | 3181 | if (hctxs[i]) |
34d11ffa | 3182 | blk_mq_exit_hctx(q, set, hctxs[i], i); |
34d11ffa JW |
3183 | hctxs[i] = hctx; |
3184 | } else { | |
3185 | if (hctxs[i]) | |
3186 | pr_warn("Allocate new hctx on node %d fails,\ | |
3187 | fallback to previous one on node %d\n", | |
3188 | node, hctxs[i]->numa_node); | |
3189 | else | |
3190 | break; | |
868f2f0b | 3191 | } |
320ae51f | 3192 | } |
e01ad46d JW |
3193 | /* |
3194 | * Increasing nr_hw_queues fails. Free the newly allocated | |
3195 | * hctxs and keep the previous q->nr_hw_queues. | |
3196 | */ | |
3197 | if (i != set->nr_hw_queues) { | |
3198 | j = q->nr_hw_queues; | |
3199 | end = i; | |
3200 | } else { | |
3201 | j = i; | |
3202 | end = q->nr_hw_queues; | |
3203 | q->nr_hw_queues = set->nr_hw_queues; | |
3204 | } | |
34d11ffa | 3205 | |
e01ad46d | 3206 | for (; j < end; j++) { |
868f2f0b KB |
3207 | struct blk_mq_hw_ctx *hctx = hctxs[j]; |
3208 | ||
3209 | if (hctx) { | |
cc71a6f4 JA |
3210 | if (hctx->tags) |
3211 | blk_mq_free_map_and_requests(set, j); | |
868f2f0b | 3212 | blk_mq_exit_hctx(q, set, hctx, j); |
868f2f0b | 3213 | hctxs[j] = NULL; |
868f2f0b KB |
3214 | } |
3215 | } | |
fb350e0a | 3216 | mutex_unlock(&q->sysfs_lock); |
868f2f0b KB |
3217 | } |
3218 | ||
3219 | struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, | |
737eb78e DLM |
3220 | struct request_queue *q, |
3221 | bool elevator_init) | |
868f2f0b | 3222 | { |
66841672 ML |
3223 | /* mark the queue as mq asap */ |
3224 | q->mq_ops = set->ops; | |
3225 | ||
34dbad5d | 3226 | q->poll_cb = blk_stat_alloc_callback(blk_mq_poll_stats_fn, |
720b8ccc SB |
3227 | blk_mq_poll_stats_bkt, |
3228 | BLK_MQ_POLL_STATS_BKTS, q); | |
34dbad5d OS |
3229 | if (!q->poll_cb) |
3230 | goto err_exit; | |
3231 | ||
1db4909e | 3232 | if (blk_mq_alloc_ctxs(q)) |
41de54c6 | 3233 | goto err_poll; |
868f2f0b | 3234 | |
737f98cf ML |
3235 | /* init q->mq_kobj and sw queues' kobjects */ |
3236 | blk_mq_sysfs_init(q); | |
3237 | ||
2f8f1336 ML |
3238 | INIT_LIST_HEAD(&q->unused_hctx_list); |
3239 | spin_lock_init(&q->unused_hctx_lock); | |
3240 | ||
868f2f0b KB |
3241 | blk_mq_realloc_hw_ctxs(set, q); |
3242 | if (!q->nr_hw_queues) | |
3243 | goto err_hctxs; | |
320ae51f | 3244 | |
287922eb | 3245 | INIT_WORK(&q->timeout_work, blk_mq_timeout_work); |
e56f698b | 3246 | blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ); |
320ae51f | 3247 | |
a8908939 | 3248 | q->tag_set = set; |
320ae51f | 3249 | |
94eddfbe | 3250 | q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; |
cd19181b ML |
3251 | if (set->nr_maps > HCTX_TYPE_POLL && |
3252 | set->map[HCTX_TYPE_POLL].nr_queues) | |
6544d229 | 3253 | blk_queue_flag_set(QUEUE_FLAG_POLL, q); |
320ae51f | 3254 | |
1be036e9 CH |
3255 | q->sg_reserved_size = INT_MAX; |
3256 | ||
2849450a | 3257 | INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work); |
6fca6a61 CH |
3258 | INIT_LIST_HEAD(&q->requeue_list); |
3259 | spin_lock_init(&q->requeue_lock); | |
3260 | ||
eba71768 JA |
3261 | q->nr_requests = set->queue_depth; |
3262 | ||
64f1c21e JA |
3263 | /* |
3264 | * Default to classic polling | |
3265 | */ | |
29ece8b4 | 3266 | q->poll_nsec = BLK_MQ_POLL_CLASSIC; |
64f1c21e | 3267 | |
24d2f903 | 3268 | blk_mq_init_cpu_queues(q, set->nr_hw_queues); |
0d2602ca | 3269 | blk_mq_add_queue_tag_set(set, q); |
4b855ad3 | 3270 | blk_mq_map_swqueue(q); |
4593fdbe | 3271 | |
737eb78e DLM |
3272 | if (elevator_init) |
3273 | elevator_init_mq(q); | |
d3484991 | 3274 | |
320ae51f | 3275 | return q; |
18741986 | 3276 | |
320ae51f | 3277 | err_hctxs: |
868f2f0b | 3278 | kfree(q->queue_hw_ctx); |
73d9c8d4 | 3279 | q->nr_hw_queues = 0; |
1db4909e | 3280 | blk_mq_sysfs_deinit(q); |
41de54c6 JS |
3281 | err_poll: |
3282 | blk_stat_free_callback(q->poll_cb); | |
3283 | q->poll_cb = NULL; | |
c7de5726 ML |
3284 | err_exit: |
3285 | q->mq_ops = NULL; | |
320ae51f JA |
3286 | return ERR_PTR(-ENOMEM); |
3287 | } | |
b62c21b7 | 3288 | EXPORT_SYMBOL(blk_mq_init_allocated_queue); |
320ae51f | 3289 | |
c7e2d94b ML |
3290 | /* tags can _not_ be used after returning from blk_mq_exit_queue */ |
3291 | void blk_mq_exit_queue(struct request_queue *q) | |
320ae51f | 3292 | { |
630ef623 | 3293 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 3294 | |
630ef623 | 3295 | /* Checks hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED. */ |
624dbe47 | 3296 | blk_mq_exit_hw_queues(q, set, set->nr_hw_queues); |
630ef623 BVA |
3297 | /* May clear BLK_MQ_F_TAG_QUEUE_SHARED in hctx->flags. */ |
3298 | blk_mq_del_queue_tag_set(q); | |
320ae51f | 3299 | } |
320ae51f | 3300 | |
a5164405 JA |
3301 | static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) |
3302 | { | |
3303 | int i; | |
3304 | ||
8229cca8 | 3305 | for (i = 0; i < set->nr_hw_queues; i++) { |
03b63b02 | 3306 | if (!__blk_mq_alloc_map_and_request(set, i)) |
a5164405 | 3307 | goto out_unwind; |
8229cca8 XT |
3308 | cond_resched(); |
3309 | } | |
a5164405 JA |
3310 | |
3311 | return 0; | |
3312 | ||
3313 | out_unwind: | |
3314 | while (--i >= 0) | |
2e194422 | 3315 | blk_mq_free_map_and_requests(set, i); |
a5164405 | 3316 | |
a5164405 JA |
3317 | return -ENOMEM; |
3318 | } | |
3319 | ||
3320 | /* | |
3321 | * Allocate the request maps associated with this tag_set. Note that this | |
3322 | * may reduce the depth asked for, if memory is tight. set->queue_depth | |
3323 | * will be updated to reflect the allocated depth. | |
3324 | */ | |
79fab528 | 3325 | static int blk_mq_alloc_map_and_requests(struct blk_mq_tag_set *set) |
a5164405 JA |
3326 | { |
3327 | unsigned int depth; | |
3328 | int err; | |
3329 | ||
3330 | depth = set->queue_depth; | |
3331 | do { | |
3332 | err = __blk_mq_alloc_rq_maps(set); | |
3333 | if (!err) | |
3334 | break; | |
3335 | ||
3336 | set->queue_depth >>= 1; | |
3337 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) { | |
3338 | err = -ENOMEM; | |
3339 | break; | |
3340 | } | |
3341 | } while (set->queue_depth); | |
3342 | ||
3343 | if (!set->queue_depth || err) { | |
3344 | pr_err("blk-mq: failed to allocate request map\n"); | |
3345 | return -ENOMEM; | |
3346 | } | |
3347 | ||
3348 | if (depth != set->queue_depth) | |
3349 | pr_info("blk-mq: reduced tag depth (%u -> %u)\n", | |
3350 | depth, set->queue_depth); | |
3351 | ||
3352 | return 0; | |
3353 | } | |
3354 | ||
ebe8bddb OS |
3355 | static int blk_mq_update_queue_map(struct blk_mq_tag_set *set) |
3356 | { | |
6e66b493 BVA |
3357 | /* |
3358 | * blk_mq_map_queues() and multiple .map_queues() implementations | |
3359 | * expect that set->map[HCTX_TYPE_DEFAULT].nr_queues is set to the | |
3360 | * number of hardware queues. | |
3361 | */ | |
3362 | if (set->nr_maps == 1) | |
3363 | set->map[HCTX_TYPE_DEFAULT].nr_queues = set->nr_hw_queues; | |
3364 | ||
59388702 | 3365 | if (set->ops->map_queues && !is_kdump_kernel()) { |
b3c661b1 JA |
3366 | int i; |
3367 | ||
7d4901a9 ML |
3368 | /* |
3369 | * transport .map_queues is usually done in the following | |
3370 | * way: | |
3371 | * | |
3372 | * for (queue = 0; queue < set->nr_hw_queues; queue++) { | |
3373 | * mask = get_cpu_mask(queue) | |
3374 | * for_each_cpu(cpu, mask) | |
b3c661b1 | 3375 | * set->map[x].mq_map[cpu] = queue; |
7d4901a9 ML |
3376 | * } |
3377 | * | |
3378 | * When we need to remap, the table has to be cleared for | |
3379 | * killing stale mapping since one CPU may not be mapped | |
3380 | * to any hw queue. | |
3381 | */ | |
b3c661b1 JA |
3382 | for (i = 0; i < set->nr_maps; i++) |
3383 | blk_mq_clear_mq_map(&set->map[i]); | |
7d4901a9 | 3384 | |
ebe8bddb | 3385 | return set->ops->map_queues(set); |
b3c661b1 JA |
3386 | } else { |
3387 | BUG_ON(set->nr_maps > 1); | |
7d76f856 | 3388 | return blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]); |
b3c661b1 | 3389 | } |
ebe8bddb OS |
3390 | } |
3391 | ||
f7e76dbc BVA |
3392 | static int blk_mq_realloc_tag_set_tags(struct blk_mq_tag_set *set, |
3393 | int cur_nr_hw_queues, int new_nr_hw_queues) | |
3394 | { | |
3395 | struct blk_mq_tags **new_tags; | |
3396 | ||
3397 | if (cur_nr_hw_queues >= new_nr_hw_queues) | |
3398 | return 0; | |
3399 | ||
3400 | new_tags = kcalloc_node(new_nr_hw_queues, sizeof(struct blk_mq_tags *), | |
3401 | GFP_KERNEL, set->numa_node); | |
3402 | if (!new_tags) | |
3403 | return -ENOMEM; | |
3404 | ||
3405 | if (set->tags) | |
3406 | memcpy(new_tags, set->tags, cur_nr_hw_queues * | |
3407 | sizeof(*set->tags)); | |
3408 | kfree(set->tags); | |
3409 | set->tags = new_tags; | |
3410 | set->nr_hw_queues = new_nr_hw_queues; | |
3411 | ||
3412 | return 0; | |
3413 | } | |
3414 | ||
91cdf265 MI |
3415 | static int blk_mq_alloc_tag_set_tags(struct blk_mq_tag_set *set, |
3416 | int new_nr_hw_queues) | |
3417 | { | |
3418 | return blk_mq_realloc_tag_set_tags(set, 0, new_nr_hw_queues); | |
3419 | } | |
3420 | ||
a4391c64 JA |
3421 | /* |
3422 | * Alloc a tag set to be associated with one or more request queues. | |
3423 | * May fail with EINVAL for various error conditions. May adjust the | |
c018c84f | 3424 | * requested depth down, if it's too large. In that case, the set |
a4391c64 JA |
3425 | * value will be stored in set->queue_depth. |
3426 | */ | |
24d2f903 CH |
3427 | int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) |
3428 | { | |
b3c661b1 | 3429 | int i, ret; |
da695ba2 | 3430 | |
205fb5f5 BVA |
3431 | BUILD_BUG_ON(BLK_MQ_MAX_DEPTH > 1 << BLK_MQ_UNIQUE_TAG_BITS); |
3432 | ||
24d2f903 CH |
3433 | if (!set->nr_hw_queues) |
3434 | return -EINVAL; | |
a4391c64 | 3435 | if (!set->queue_depth) |
24d2f903 CH |
3436 | return -EINVAL; |
3437 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) | |
3438 | return -EINVAL; | |
3439 | ||
7d7e0f90 | 3440 | if (!set->ops->queue_rq) |
24d2f903 CH |
3441 | return -EINVAL; |
3442 | ||
de148297 ML |
3443 | if (!set->ops->get_budget ^ !set->ops->put_budget) |
3444 | return -EINVAL; | |
3445 | ||
a4391c64 JA |
3446 | if (set->queue_depth > BLK_MQ_MAX_DEPTH) { |
3447 | pr_info("blk-mq: reduced tag depth to %u\n", | |
3448 | BLK_MQ_MAX_DEPTH); | |
3449 | set->queue_depth = BLK_MQ_MAX_DEPTH; | |
3450 | } | |
24d2f903 | 3451 | |
b3c661b1 JA |
3452 | if (!set->nr_maps) |
3453 | set->nr_maps = 1; | |
3454 | else if (set->nr_maps > HCTX_MAX_TYPES) | |
3455 | return -EINVAL; | |
3456 | ||
6637fadf SL |
3457 | /* |
3458 | * If a crashdump is active, then we are potentially in a very | |
3459 | * memory constrained environment. Limit us to 1 queue and | |
3460 | * 64 tags to prevent using too much memory. | |
3461 | */ | |
3462 | if (is_kdump_kernel()) { | |
3463 | set->nr_hw_queues = 1; | |
59388702 | 3464 | set->nr_maps = 1; |
6637fadf SL |
3465 | set->queue_depth = min(64U, set->queue_depth); |
3466 | } | |
868f2f0b | 3467 | /* |
392546ae JA |
3468 | * There is no use for more h/w queues than cpus if we just have |
3469 | * a single map | |
868f2f0b | 3470 | */ |
392546ae | 3471 | if (set->nr_maps == 1 && set->nr_hw_queues > nr_cpu_ids) |
868f2f0b | 3472 | set->nr_hw_queues = nr_cpu_ids; |
6637fadf | 3473 | |
91cdf265 | 3474 | if (blk_mq_alloc_tag_set_tags(set, set->nr_hw_queues) < 0) |
a5164405 | 3475 | return -ENOMEM; |
24d2f903 | 3476 | |
da695ba2 | 3477 | ret = -ENOMEM; |
b3c661b1 JA |
3478 | for (i = 0; i < set->nr_maps; i++) { |
3479 | set->map[i].mq_map = kcalloc_node(nr_cpu_ids, | |
07b35eb5 | 3480 | sizeof(set->map[i].mq_map[0]), |
b3c661b1 JA |
3481 | GFP_KERNEL, set->numa_node); |
3482 | if (!set->map[i].mq_map) | |
3483 | goto out_free_mq_map; | |
59388702 | 3484 | set->map[i].nr_queues = is_kdump_kernel() ? 1 : set->nr_hw_queues; |
b3c661b1 | 3485 | } |
bdd17e75 | 3486 | |
ebe8bddb | 3487 | ret = blk_mq_update_queue_map(set); |
da695ba2 CH |
3488 | if (ret) |
3489 | goto out_free_mq_map; | |
3490 | ||
79fab528 | 3491 | ret = blk_mq_alloc_map_and_requests(set); |
da695ba2 | 3492 | if (ret) |
bdd17e75 | 3493 | goto out_free_mq_map; |
24d2f903 | 3494 | |
32bc15af | 3495 | if (blk_mq_is_sbitmap_shared(set->flags)) { |
f1b49fdc JG |
3496 | atomic_set(&set->active_queues_shared_sbitmap, 0); |
3497 | ||
32bc15af JG |
3498 | if (blk_mq_init_shared_sbitmap(set, set->flags)) { |
3499 | ret = -ENOMEM; | |
3500 | goto out_free_mq_rq_maps; | |
3501 | } | |
3502 | } | |
3503 | ||
0d2602ca JA |
3504 | mutex_init(&set->tag_list_lock); |
3505 | INIT_LIST_HEAD(&set->tag_list); | |
3506 | ||
24d2f903 | 3507 | return 0; |
bdd17e75 | 3508 | |
32bc15af JG |
3509 | out_free_mq_rq_maps: |
3510 | for (i = 0; i < set->nr_hw_queues; i++) | |
3511 | blk_mq_free_map_and_requests(set, i); | |
bdd17e75 | 3512 | out_free_mq_map: |
b3c661b1 JA |
3513 | for (i = 0; i < set->nr_maps; i++) { |
3514 | kfree(set->map[i].mq_map); | |
3515 | set->map[i].mq_map = NULL; | |
3516 | } | |
5676e7b6 RE |
3517 | kfree(set->tags); |
3518 | set->tags = NULL; | |
da695ba2 | 3519 | return ret; |
24d2f903 CH |
3520 | } |
3521 | EXPORT_SYMBOL(blk_mq_alloc_tag_set); | |
3522 | ||
3523 | void blk_mq_free_tag_set(struct blk_mq_tag_set *set) | |
3524 | { | |
b3c661b1 | 3525 | int i, j; |
24d2f903 | 3526 | |
f7e76dbc | 3527 | for (i = 0; i < set->nr_hw_queues; i++) |
cc71a6f4 | 3528 | blk_mq_free_map_and_requests(set, i); |
484b4061 | 3529 | |
32bc15af JG |
3530 | if (blk_mq_is_sbitmap_shared(set->flags)) |
3531 | blk_mq_exit_shared_sbitmap(set); | |
3532 | ||
b3c661b1 JA |
3533 | for (j = 0; j < set->nr_maps; j++) { |
3534 | kfree(set->map[j].mq_map); | |
3535 | set->map[j].mq_map = NULL; | |
3536 | } | |
bdd17e75 | 3537 | |
981bd189 | 3538 | kfree(set->tags); |
5676e7b6 | 3539 | set->tags = NULL; |
24d2f903 CH |
3540 | } |
3541 | EXPORT_SYMBOL(blk_mq_free_tag_set); | |
3542 | ||
e3a2b3f9 JA |
3543 | int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) |
3544 | { | |
3545 | struct blk_mq_tag_set *set = q->tag_set; | |
3546 | struct blk_mq_hw_ctx *hctx; | |
3547 | int i, ret; | |
3548 | ||
bd166ef1 | 3549 | if (!set) |
e3a2b3f9 JA |
3550 | return -EINVAL; |
3551 | ||
e5fa8140 AZ |
3552 | if (q->nr_requests == nr) |
3553 | return 0; | |
3554 | ||
70f36b60 | 3555 | blk_mq_freeze_queue(q); |
24f5a90f | 3556 | blk_mq_quiesce_queue(q); |
70f36b60 | 3557 | |
e3a2b3f9 JA |
3558 | ret = 0; |
3559 | queue_for_each_hw_ctx(q, hctx, i) { | |
e9137d4b KB |
3560 | if (!hctx->tags) |
3561 | continue; | |
bd166ef1 JA |
3562 | /* |
3563 | * If we're using an MQ scheduler, just update the scheduler | |
3564 | * queue depth. This is similar to what the old code would do. | |
3565 | */ | |
70f36b60 | 3566 | if (!hctx->sched_tags) { |
c2e82a23 | 3567 | ret = blk_mq_tag_update_depth(hctx, &hctx->tags, nr, |
70f36b60 | 3568 | false); |
32bc15af JG |
3569 | if (!ret && blk_mq_is_sbitmap_shared(set->flags)) |
3570 | blk_mq_tag_resize_shared_sbitmap(set, nr); | |
70f36b60 JA |
3571 | } else { |
3572 | ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags, | |
3573 | nr, true); | |
3574 | } | |
e3a2b3f9 JA |
3575 | if (ret) |
3576 | break; | |
77f1e0a5 JA |
3577 | if (q->elevator && q->elevator->type->ops.depth_updated) |
3578 | q->elevator->type->ops.depth_updated(hctx); | |
e3a2b3f9 JA |
3579 | } |
3580 | ||
3581 | if (!ret) | |
3582 | q->nr_requests = nr; | |
3583 | ||
24f5a90f | 3584 | blk_mq_unquiesce_queue(q); |
70f36b60 | 3585 | blk_mq_unfreeze_queue(q); |
70f36b60 | 3586 | |
e3a2b3f9 JA |
3587 | return ret; |
3588 | } | |
3589 | ||
d48ece20 JW |
3590 | /* |
3591 | * request_queue and elevator_type pair. | |
3592 | * It is just used by __blk_mq_update_nr_hw_queues to cache | |
3593 | * the elevator_type associated with a request_queue. | |
3594 | */ | |
3595 | struct blk_mq_qe_pair { | |
3596 | struct list_head node; | |
3597 | struct request_queue *q; | |
3598 | struct elevator_type *type; | |
3599 | }; | |
3600 | ||
3601 | /* | |
3602 | * Cache the elevator_type in qe pair list and switch the | |
3603 | * io scheduler to 'none' | |
3604 | */ | |
3605 | static bool blk_mq_elv_switch_none(struct list_head *head, | |
3606 | struct request_queue *q) | |
3607 | { | |
3608 | struct blk_mq_qe_pair *qe; | |
3609 | ||
3610 | if (!q->elevator) | |
3611 | return true; | |
3612 | ||
3613 | qe = kmalloc(sizeof(*qe), GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY); | |
3614 | if (!qe) | |
3615 | return false; | |
3616 | ||
3617 | INIT_LIST_HEAD(&qe->node); | |
3618 | qe->q = q; | |
3619 | qe->type = q->elevator->type; | |
3620 | list_add(&qe->node, head); | |
3621 | ||
3622 | mutex_lock(&q->sysfs_lock); | |
3623 | /* | |
3624 | * After elevator_switch_mq, the previous elevator_queue will be | |
3625 | * released by elevator_release. The reference of the io scheduler | |
3626 | * module get by elevator_get will also be put. So we need to get | |
3627 | * a reference of the io scheduler module here to prevent it to be | |
3628 | * removed. | |
3629 | */ | |
3630 | __module_get(qe->type->elevator_owner); | |
3631 | elevator_switch_mq(q, NULL); | |
3632 | mutex_unlock(&q->sysfs_lock); | |
3633 | ||
3634 | return true; | |
3635 | } | |
3636 | ||
3637 | static void blk_mq_elv_switch_back(struct list_head *head, | |
3638 | struct request_queue *q) | |
3639 | { | |
3640 | struct blk_mq_qe_pair *qe; | |
3641 | struct elevator_type *t = NULL; | |
3642 | ||
3643 | list_for_each_entry(qe, head, node) | |
3644 | if (qe->q == q) { | |
3645 | t = qe->type; | |
3646 | break; | |
3647 | } | |
3648 | ||
3649 | if (!t) | |
3650 | return; | |
3651 | ||
3652 | list_del(&qe->node); | |
3653 | kfree(qe); | |
3654 | ||
3655 | mutex_lock(&q->sysfs_lock); | |
3656 | elevator_switch_mq(q, t); | |
3657 | mutex_unlock(&q->sysfs_lock); | |
3658 | } | |
3659 | ||
e4dc2b32 KB |
3660 | static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, |
3661 | int nr_hw_queues) | |
868f2f0b KB |
3662 | { |
3663 | struct request_queue *q; | |
d48ece20 | 3664 | LIST_HEAD(head); |
e01ad46d | 3665 | int prev_nr_hw_queues; |
868f2f0b | 3666 | |
705cda97 BVA |
3667 | lockdep_assert_held(&set->tag_list_lock); |
3668 | ||
392546ae | 3669 | if (set->nr_maps == 1 && nr_hw_queues > nr_cpu_ids) |
868f2f0b | 3670 | nr_hw_queues = nr_cpu_ids; |
fe35ec58 WZ |
3671 | if (nr_hw_queues < 1) |
3672 | return; | |
3673 | if (set->nr_maps == 1 && nr_hw_queues == set->nr_hw_queues) | |
868f2f0b KB |
3674 | return; |
3675 | ||
3676 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
3677 | blk_mq_freeze_queue(q); | |
d48ece20 JW |
3678 | /* |
3679 | * Switch IO scheduler to 'none', cleaning up the data associated | |
3680 | * with the previous scheduler. We will switch back once we are done | |
3681 | * updating the new sw to hw queue mappings. | |
3682 | */ | |
3683 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
3684 | if (!blk_mq_elv_switch_none(&head, q)) | |
3685 | goto switch_back; | |
868f2f0b | 3686 | |
477e19de JW |
3687 | list_for_each_entry(q, &set->tag_list, tag_set_list) { |
3688 | blk_mq_debugfs_unregister_hctxs(q); | |
3689 | blk_mq_sysfs_unregister(q); | |
3690 | } | |
3691 | ||
a2584e43 | 3692 | prev_nr_hw_queues = set->nr_hw_queues; |
f7e76dbc BVA |
3693 | if (blk_mq_realloc_tag_set_tags(set, set->nr_hw_queues, nr_hw_queues) < |
3694 | 0) | |
3695 | goto reregister; | |
3696 | ||
868f2f0b | 3697 | set->nr_hw_queues = nr_hw_queues; |
e01ad46d | 3698 | fallback: |
aa880ad6 | 3699 | blk_mq_update_queue_map(set); |
868f2f0b KB |
3700 | list_for_each_entry(q, &set->tag_list, tag_set_list) { |
3701 | blk_mq_realloc_hw_ctxs(set, q); | |
e01ad46d JW |
3702 | if (q->nr_hw_queues != set->nr_hw_queues) { |
3703 | pr_warn("Increasing nr_hw_queues to %d fails, fallback to %d\n", | |
3704 | nr_hw_queues, prev_nr_hw_queues); | |
3705 | set->nr_hw_queues = prev_nr_hw_queues; | |
7d76f856 | 3706 | blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]); |
e01ad46d JW |
3707 | goto fallback; |
3708 | } | |
477e19de JW |
3709 | blk_mq_map_swqueue(q); |
3710 | } | |
3711 | ||
f7e76dbc | 3712 | reregister: |
477e19de JW |
3713 | list_for_each_entry(q, &set->tag_list, tag_set_list) { |
3714 | blk_mq_sysfs_register(q); | |
3715 | blk_mq_debugfs_register_hctxs(q); | |
868f2f0b KB |
3716 | } |
3717 | ||
d48ece20 JW |
3718 | switch_back: |
3719 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
3720 | blk_mq_elv_switch_back(&head, q); | |
3721 | ||
868f2f0b KB |
3722 | list_for_each_entry(q, &set->tag_list, tag_set_list) |
3723 | blk_mq_unfreeze_queue(q); | |
3724 | } | |
e4dc2b32 KB |
3725 | |
3726 | void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues) | |
3727 | { | |
3728 | mutex_lock(&set->tag_list_lock); | |
3729 | __blk_mq_update_nr_hw_queues(set, nr_hw_queues); | |
3730 | mutex_unlock(&set->tag_list_lock); | |
3731 | } | |
868f2f0b KB |
3732 | EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues); |
3733 | ||
34dbad5d OS |
3734 | /* Enable polling stats and return whether they were already enabled. */ |
3735 | static bool blk_poll_stats_enable(struct request_queue *q) | |
3736 | { | |
3737 | if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags) || | |
7dfdbc73 | 3738 | blk_queue_flag_test_and_set(QUEUE_FLAG_POLL_STATS, q)) |
34dbad5d OS |
3739 | return true; |
3740 | blk_stat_add_callback(q, q->poll_cb); | |
3741 | return false; | |
3742 | } | |
3743 | ||
3744 | static void blk_mq_poll_stats_start(struct request_queue *q) | |
3745 | { | |
3746 | /* | |
3747 | * We don't arm the callback if polling stats are not enabled or the | |
3748 | * callback is already active. | |
3749 | */ | |
3750 | if (!test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags) || | |
3751 | blk_stat_is_active(q->poll_cb)) | |
3752 | return; | |
3753 | ||
3754 | blk_stat_activate_msecs(q->poll_cb, 100); | |
3755 | } | |
3756 | ||
3757 | static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb) | |
3758 | { | |
3759 | struct request_queue *q = cb->data; | |
720b8ccc | 3760 | int bucket; |
34dbad5d | 3761 | |
720b8ccc SB |
3762 | for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS; bucket++) { |
3763 | if (cb->stat[bucket].nr_samples) | |
3764 | q->poll_stat[bucket] = cb->stat[bucket]; | |
3765 | } | |
34dbad5d OS |
3766 | } |
3767 | ||
64f1c21e | 3768 | static unsigned long blk_mq_poll_nsecs(struct request_queue *q, |
64f1c21e JA |
3769 | struct request *rq) |
3770 | { | |
64f1c21e | 3771 | unsigned long ret = 0; |
720b8ccc | 3772 | int bucket; |
64f1c21e JA |
3773 | |
3774 | /* | |
3775 | * If stats collection isn't on, don't sleep but turn it on for | |
3776 | * future users | |
3777 | */ | |
34dbad5d | 3778 | if (!blk_poll_stats_enable(q)) |
64f1c21e JA |
3779 | return 0; |
3780 | ||
64f1c21e JA |
3781 | /* |
3782 | * As an optimistic guess, use half of the mean service time | |
3783 | * for this type of request. We can (and should) make this smarter. | |
3784 | * For instance, if the completion latencies are tight, we can | |
3785 | * get closer than just half the mean. This is especially | |
3786 | * important on devices where the completion latencies are longer | |
720b8ccc SB |
3787 | * than ~10 usec. We do use the stats for the relevant IO size |
3788 | * if available which does lead to better estimates. | |
64f1c21e | 3789 | */ |
720b8ccc SB |
3790 | bucket = blk_mq_poll_stats_bkt(rq); |
3791 | if (bucket < 0) | |
3792 | return ret; | |
3793 | ||
3794 | if (q->poll_stat[bucket].nr_samples) | |
3795 | ret = (q->poll_stat[bucket].mean + 1) / 2; | |
64f1c21e JA |
3796 | |
3797 | return ret; | |
3798 | } | |
3799 | ||
06426adf JA |
3800 | static bool blk_mq_poll_hybrid_sleep(struct request_queue *q, |
3801 | struct request *rq) | |
3802 | { | |
3803 | struct hrtimer_sleeper hs; | |
3804 | enum hrtimer_mode mode; | |
64f1c21e | 3805 | unsigned int nsecs; |
06426adf JA |
3806 | ktime_t kt; |
3807 | ||
76a86f9d | 3808 | if (rq->rq_flags & RQF_MQ_POLL_SLEPT) |
64f1c21e JA |
3809 | return false; |
3810 | ||
3811 | /* | |
1052b8ac | 3812 | * If we get here, hybrid polling is enabled. Hence poll_nsec can be: |
64f1c21e | 3813 | * |
64f1c21e JA |
3814 | * 0: use half of prev avg |
3815 | * >0: use this specific value | |
3816 | */ | |
1052b8ac | 3817 | if (q->poll_nsec > 0) |
64f1c21e JA |
3818 | nsecs = q->poll_nsec; |
3819 | else | |
cae740a0 | 3820 | nsecs = blk_mq_poll_nsecs(q, rq); |
64f1c21e JA |
3821 | |
3822 | if (!nsecs) | |
06426adf JA |
3823 | return false; |
3824 | ||
76a86f9d | 3825 | rq->rq_flags |= RQF_MQ_POLL_SLEPT; |
06426adf JA |
3826 | |
3827 | /* | |
3828 | * This will be replaced with the stats tracking code, using | |
3829 | * 'avg_completion_time / 2' as the pre-sleep target. | |
3830 | */ | |
8b0e1953 | 3831 | kt = nsecs; |
06426adf JA |
3832 | |
3833 | mode = HRTIMER_MODE_REL; | |
dbc1625f | 3834 | hrtimer_init_sleeper_on_stack(&hs, CLOCK_MONOTONIC, mode); |
06426adf JA |
3835 | hrtimer_set_expires(&hs.timer, kt); |
3836 | ||
06426adf | 3837 | do { |
5a61c363 | 3838 | if (blk_mq_rq_state(rq) == MQ_RQ_COMPLETE) |
06426adf JA |
3839 | break; |
3840 | set_current_state(TASK_UNINTERRUPTIBLE); | |
9dd8813e | 3841 | hrtimer_sleeper_start_expires(&hs, mode); |
06426adf JA |
3842 | if (hs.task) |
3843 | io_schedule(); | |
3844 | hrtimer_cancel(&hs.timer); | |
3845 | mode = HRTIMER_MODE_ABS; | |
3846 | } while (hs.task && !signal_pending(current)); | |
3847 | ||
3848 | __set_current_state(TASK_RUNNING); | |
3849 | destroy_hrtimer_on_stack(&hs.timer); | |
3850 | return true; | |
3851 | } | |
3852 | ||
1052b8ac JA |
3853 | static bool blk_mq_poll_hybrid(struct request_queue *q, |
3854 | struct blk_mq_hw_ctx *hctx, blk_qc_t cookie) | |
bbd7bb70 | 3855 | { |
1052b8ac JA |
3856 | struct request *rq; |
3857 | ||
29ece8b4 | 3858 | if (q->poll_nsec == BLK_MQ_POLL_CLASSIC) |
1052b8ac JA |
3859 | return false; |
3860 | ||
3861 | if (!blk_qc_t_is_internal(cookie)) | |
3862 | rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie)); | |
3863 | else { | |
3864 | rq = blk_mq_tag_to_rq(hctx->sched_tags, blk_qc_t_to_tag(cookie)); | |
3865 | /* | |
3866 | * With scheduling, if the request has completed, we'll | |
3867 | * get a NULL return here, as we clear the sched tag when | |
3868 | * that happens. The request still remains valid, like always, | |
3869 | * so we should be safe with just the NULL check. | |
3870 | */ | |
3871 | if (!rq) | |
3872 | return false; | |
3873 | } | |
3874 | ||
cae740a0 | 3875 | return blk_mq_poll_hybrid_sleep(q, rq); |
1052b8ac JA |
3876 | } |
3877 | ||
529262d5 CH |
3878 | /** |
3879 | * blk_poll - poll for IO completions | |
3880 | * @q: the queue | |
3881 | * @cookie: cookie passed back at IO submission time | |
3882 | * @spin: whether to spin for completions | |
3883 | * | |
3884 | * Description: | |
3885 | * Poll for completions on the passed in queue. Returns number of | |
3886 | * completed entries found. If @spin is true, then blk_poll will continue | |
3887 | * looping until at least one completion is found, unless the task is | |
3888 | * otherwise marked running (or we need to reschedule). | |
3889 | */ | |
3890 | int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin) | |
1052b8ac JA |
3891 | { |
3892 | struct blk_mq_hw_ctx *hctx; | |
bbd7bb70 JA |
3893 | long state; |
3894 | ||
529262d5 CH |
3895 | if (!blk_qc_t_valid(cookie) || |
3896 | !test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) | |
1052b8ac JA |
3897 | return 0; |
3898 | ||
529262d5 CH |
3899 | if (current->plug) |
3900 | blk_flush_plug_list(current->plug, false); | |
3901 | ||
1052b8ac JA |
3902 | hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)]; |
3903 | ||
06426adf JA |
3904 | /* |
3905 | * If we sleep, have the caller restart the poll loop to reset | |
3906 | * the state. Like for the other success return cases, the | |
3907 | * caller is responsible for checking if the IO completed. If | |
3908 | * the IO isn't complete, we'll get called again and will go | |
f6f371f7 PB |
3909 | * straight to the busy poll loop. If specified not to spin, |
3910 | * we also should not sleep. | |
06426adf | 3911 | */ |
f6f371f7 | 3912 | if (spin && blk_mq_poll_hybrid(q, hctx, cookie)) |
85f4d4b6 | 3913 | return 1; |
06426adf | 3914 | |
bbd7bb70 JA |
3915 | hctx->poll_considered++; |
3916 | ||
3917 | state = current->state; | |
aa61bec3 | 3918 | do { |
bbd7bb70 JA |
3919 | int ret; |
3920 | ||
3921 | hctx->poll_invoked++; | |
3922 | ||
9743139c | 3923 | ret = q->mq_ops->poll(hctx); |
bbd7bb70 JA |
3924 | if (ret > 0) { |
3925 | hctx->poll_success++; | |
849a3700 | 3926 | __set_current_state(TASK_RUNNING); |
85f4d4b6 | 3927 | return ret; |
bbd7bb70 JA |
3928 | } |
3929 | ||
3930 | if (signal_pending_state(state, current)) | |
849a3700 | 3931 | __set_current_state(TASK_RUNNING); |
bbd7bb70 JA |
3932 | |
3933 | if (current->state == TASK_RUNNING) | |
85f4d4b6 | 3934 | return 1; |
0a1b8b87 | 3935 | if (ret < 0 || !spin) |
bbd7bb70 JA |
3936 | break; |
3937 | cpu_relax(); | |
aa61bec3 | 3938 | } while (!need_resched()); |
bbd7bb70 | 3939 | |
67b4110f | 3940 | __set_current_state(TASK_RUNNING); |
85f4d4b6 | 3941 | return 0; |
bbd7bb70 | 3942 | } |
529262d5 | 3943 | EXPORT_SYMBOL_GPL(blk_poll); |
bbd7bb70 | 3944 | |
9cf2bab6 JA |
3945 | unsigned int blk_mq_rq_cpu(struct request *rq) |
3946 | { | |
3947 | return rq->mq_ctx->cpu; | |
3948 | } | |
3949 | EXPORT_SYMBOL(blk_mq_rq_cpu); | |
3950 | ||
320ae51f JA |
3951 | static int __init blk_mq_init(void) |
3952 | { | |
c3077b5d CH |
3953 | int i; |
3954 | ||
3955 | for_each_possible_cpu(i) | |
f9ab4918 | 3956 | init_llist_head(&per_cpu(blk_cpu_done, i)); |
c3077b5d CH |
3957 | open_softirq(BLOCK_SOFTIRQ, blk_done_softirq); |
3958 | ||
3959 | cpuhp_setup_state_nocalls(CPUHP_BLOCK_SOFTIRQ_DEAD, | |
3960 | "block/softirq:dead", NULL, | |
3961 | blk_softirq_cpu_dead); | |
9467f859 TG |
3962 | cpuhp_setup_state_multi(CPUHP_BLK_MQ_DEAD, "block/mq:dead", NULL, |
3963 | blk_mq_hctx_notify_dead); | |
bf0beec0 ML |
3964 | cpuhp_setup_state_multi(CPUHP_AP_BLK_MQ_ONLINE, "block/mq:online", |
3965 | blk_mq_hctx_notify_online, | |
3966 | blk_mq_hctx_notify_offline); | |
320ae51f JA |
3967 | return 0; |
3968 | } | |
3969 | subsys_initcall(blk_mq_init); |