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 | |
c3077b5d CH |
44 | static DEFINE_PER_CPU(struct list_head, blk_cpu_done); |
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 JA |
97 | struct mq_inflight { |
98 | struct hd_struct *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 | ||
6131837b | 108 | if (rq->part == mi->part) |
bb4e6b14 | 109 | mi->inflight[rq_data_dir(rq)]++; |
7baa8572 JA |
110 | |
111 | return true; | |
f299b7c7 JA |
112 | } |
113 | ||
e016b782 | 114 | unsigned int blk_mq_in_flight(struct request_queue *q, struct hd_struct *part) |
f299b7c7 | 115 | { |
a2e80f6f | 116 | struct mq_inflight mi = { .part = part }; |
f299b7c7 | 117 | |
f299b7c7 | 118 | blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi); |
e016b782 | 119 | |
a2e80f6f | 120 | return mi.inflight[0] + mi.inflight[1]; |
bf0ddaba OS |
121 | } |
122 | ||
123 | void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part, | |
124 | unsigned int inflight[2]) | |
125 | { | |
a2e80f6f | 126 | struct mq_inflight mi = { .part = part }; |
bf0ddaba | 127 | |
bb4e6b14 | 128 | blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi); |
a2e80f6f PB |
129 | inflight[0] = mi.inflight[0]; |
130 | inflight[1] = mi.inflight[1]; | |
bf0ddaba OS |
131 | } |
132 | ||
1671d522 | 133 | void blk_freeze_queue_start(struct request_queue *q) |
43a5e4e2 | 134 | { |
7996a8b5 BL |
135 | mutex_lock(&q->mq_freeze_lock); |
136 | if (++q->mq_freeze_depth == 1) { | |
3ef28e83 | 137 | percpu_ref_kill(&q->q_usage_counter); |
7996a8b5 | 138 | mutex_unlock(&q->mq_freeze_lock); |
344e9ffc | 139 | if (queue_is_mq(q)) |
055f6e18 | 140 | blk_mq_run_hw_queues(q, false); |
7996a8b5 BL |
141 | } else { |
142 | mutex_unlock(&q->mq_freeze_lock); | |
cddd5d17 | 143 | } |
f3af020b | 144 | } |
1671d522 | 145 | EXPORT_SYMBOL_GPL(blk_freeze_queue_start); |
f3af020b | 146 | |
6bae363e | 147 | void blk_mq_freeze_queue_wait(struct request_queue *q) |
f3af020b | 148 | { |
3ef28e83 | 149 | wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter)); |
43a5e4e2 | 150 | } |
6bae363e | 151 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait); |
43a5e4e2 | 152 | |
f91328c4 KB |
153 | int blk_mq_freeze_queue_wait_timeout(struct request_queue *q, |
154 | unsigned long timeout) | |
155 | { | |
156 | return wait_event_timeout(q->mq_freeze_wq, | |
157 | percpu_ref_is_zero(&q->q_usage_counter), | |
158 | timeout); | |
159 | } | |
160 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait_timeout); | |
43a5e4e2 | 161 | |
f3af020b TH |
162 | /* |
163 | * Guarantee no request is in use, so we can change any data structure of | |
164 | * the queue afterward. | |
165 | */ | |
3ef28e83 | 166 | void blk_freeze_queue(struct request_queue *q) |
f3af020b | 167 | { |
3ef28e83 DW |
168 | /* |
169 | * In the !blk_mq case we are only calling this to kill the | |
170 | * q_usage_counter, otherwise this increases the freeze depth | |
171 | * and waits for it to return to zero. For this reason there is | |
172 | * no blk_unfreeze_queue(), and blk_freeze_queue() is not | |
173 | * exported to drivers as the only user for unfreeze is blk_mq. | |
174 | */ | |
1671d522 | 175 | blk_freeze_queue_start(q); |
f3af020b TH |
176 | blk_mq_freeze_queue_wait(q); |
177 | } | |
3ef28e83 DW |
178 | |
179 | void blk_mq_freeze_queue(struct request_queue *q) | |
180 | { | |
181 | /* | |
182 | * ...just an alias to keep freeze and unfreeze actions balanced | |
183 | * in the blk_mq_* namespace | |
184 | */ | |
185 | blk_freeze_queue(q); | |
186 | } | |
c761d96b | 187 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue); |
f3af020b | 188 | |
b4c6a028 | 189 | void blk_mq_unfreeze_queue(struct request_queue *q) |
320ae51f | 190 | { |
7996a8b5 BL |
191 | mutex_lock(&q->mq_freeze_lock); |
192 | q->mq_freeze_depth--; | |
193 | WARN_ON_ONCE(q->mq_freeze_depth < 0); | |
194 | if (!q->mq_freeze_depth) { | |
bdd63160 | 195 | percpu_ref_resurrect(&q->q_usage_counter); |
320ae51f | 196 | wake_up_all(&q->mq_freeze_wq); |
add703fd | 197 | } |
7996a8b5 | 198 | mutex_unlock(&q->mq_freeze_lock); |
320ae51f | 199 | } |
b4c6a028 | 200 | EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue); |
320ae51f | 201 | |
852ec809 BVA |
202 | /* |
203 | * FIXME: replace the scsi_internal_device_*block_nowait() calls in the | |
204 | * mpt3sas driver such that this function can be removed. | |
205 | */ | |
206 | void blk_mq_quiesce_queue_nowait(struct request_queue *q) | |
207 | { | |
8814ce8a | 208 | blk_queue_flag_set(QUEUE_FLAG_QUIESCED, q); |
852ec809 BVA |
209 | } |
210 | EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue_nowait); | |
211 | ||
6a83e74d | 212 | /** |
69e07c4a | 213 | * blk_mq_quiesce_queue() - wait until all ongoing dispatches have finished |
6a83e74d BVA |
214 | * @q: request queue. |
215 | * | |
216 | * Note: this function does not prevent that the struct request end_io() | |
69e07c4a ML |
217 | * callback function is invoked. Once this function is returned, we make |
218 | * sure no dispatch can happen until the queue is unquiesced via | |
219 | * blk_mq_unquiesce_queue(). | |
6a83e74d BVA |
220 | */ |
221 | void blk_mq_quiesce_queue(struct request_queue *q) | |
222 | { | |
223 | struct blk_mq_hw_ctx *hctx; | |
224 | unsigned int i; | |
225 | bool rcu = false; | |
226 | ||
1d9e9bc6 | 227 | blk_mq_quiesce_queue_nowait(q); |
f4560ffe | 228 | |
6a83e74d BVA |
229 | queue_for_each_hw_ctx(q, hctx, i) { |
230 | if (hctx->flags & BLK_MQ_F_BLOCKING) | |
05707b64 | 231 | synchronize_srcu(hctx->srcu); |
6a83e74d BVA |
232 | else |
233 | rcu = true; | |
234 | } | |
235 | if (rcu) | |
236 | synchronize_rcu(); | |
237 | } | |
238 | EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue); | |
239 | ||
e4e73913 ML |
240 | /* |
241 | * blk_mq_unquiesce_queue() - counterpart of blk_mq_quiesce_queue() | |
242 | * @q: request queue. | |
243 | * | |
244 | * This function recovers queue into the state before quiescing | |
245 | * which is done by blk_mq_quiesce_queue. | |
246 | */ | |
247 | void blk_mq_unquiesce_queue(struct request_queue *q) | |
248 | { | |
8814ce8a | 249 | blk_queue_flag_clear(QUEUE_FLAG_QUIESCED, q); |
f4560ffe | 250 | |
1d9e9bc6 ML |
251 | /* dispatch requests which are inserted during quiescing */ |
252 | blk_mq_run_hw_queues(q, true); | |
e4e73913 ML |
253 | } |
254 | EXPORT_SYMBOL_GPL(blk_mq_unquiesce_queue); | |
255 | ||
aed3ea94 JA |
256 | void blk_mq_wake_waiters(struct request_queue *q) |
257 | { | |
258 | struct blk_mq_hw_ctx *hctx; | |
259 | unsigned int i; | |
260 | ||
261 | queue_for_each_hw_ctx(q, hctx, i) | |
262 | if (blk_mq_hw_queue_mapped(hctx)) | |
263 | blk_mq_tag_wakeup_all(hctx->tags, true); | |
264 | } | |
265 | ||
fe1f4526 | 266 | /* |
9a91b05b HT |
267 | * Only need start/end time stamping if we have iostat or |
268 | * blk stats enabled, or using an IO scheduler. | |
fe1f4526 JA |
269 | */ |
270 | static inline bool blk_mq_need_time_stamp(struct request *rq) | |
271 | { | |
9a91b05b | 272 | return (rq->rq_flags & (RQF_IO_STAT | RQF_STATS)) || rq->q->elevator; |
fe1f4526 JA |
273 | } |
274 | ||
e4cdf1a1 | 275 | static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data, |
7ea4d8a4 | 276 | unsigned int tag, u64 alloc_time_ns) |
320ae51f | 277 | { |
e4cdf1a1 CH |
278 | struct blk_mq_tags *tags = blk_mq_tags_from_data(data); |
279 | struct request *rq = tags->static_rqs[tag]; | |
bf9ae8c5 | 280 | req_flags_t rq_flags = 0; |
c3a148d2 | 281 | |
42fdc5e4 | 282 | if (data->q->elevator) { |
76647368 | 283 | rq->tag = BLK_MQ_NO_TAG; |
e4cdf1a1 CH |
284 | rq->internal_tag = tag; |
285 | } else { | |
d263ed99 | 286 | if (data->hctx->flags & BLK_MQ_F_TAG_SHARED) { |
bf9ae8c5 | 287 | rq_flags = RQF_MQ_INFLIGHT; |
e4cdf1a1 CH |
288 | atomic_inc(&data->hctx->nr_active); |
289 | } | |
290 | rq->tag = tag; | |
76647368 | 291 | rq->internal_tag = BLK_MQ_NO_TAG; |
e4cdf1a1 CH |
292 | data->hctx->tags->rqs[rq->tag] = rq; |
293 | } | |
294 | ||
af76e555 | 295 | /* csd/requeue_work/fifo_time is initialized before use */ |
e4cdf1a1 CH |
296 | rq->q = data->q; |
297 | rq->mq_ctx = data->ctx; | |
ea4f995e | 298 | rq->mq_hctx = data->hctx; |
bf9ae8c5 | 299 | rq->rq_flags = rq_flags; |
7ea4d8a4 | 300 | rq->cmd_flags = data->cmd_flags; |
1b6d65a0 BVA |
301 | if (data->flags & BLK_MQ_REQ_PREEMPT) |
302 | rq->rq_flags |= RQF_PREEMPT; | |
e4cdf1a1 | 303 | if (blk_queue_io_stat(data->q)) |
e8064021 | 304 | rq->rq_flags |= RQF_IO_STAT; |
7c3fb70f | 305 | INIT_LIST_HEAD(&rq->queuelist); |
af76e555 CH |
306 | INIT_HLIST_NODE(&rq->hash); |
307 | RB_CLEAR_NODE(&rq->rb_node); | |
af76e555 CH |
308 | rq->rq_disk = NULL; |
309 | rq->part = NULL; | |
6f816b4b TH |
310 | #ifdef CONFIG_BLK_RQ_ALLOC_TIME |
311 | rq->alloc_time_ns = alloc_time_ns; | |
312 | #endif | |
fe1f4526 JA |
313 | if (blk_mq_need_time_stamp(rq)) |
314 | rq->start_time_ns = ktime_get_ns(); | |
315 | else | |
316 | rq->start_time_ns = 0; | |
544ccc8d | 317 | rq->io_start_time_ns = 0; |
3d244306 | 318 | rq->stats_sectors = 0; |
af76e555 CH |
319 | rq->nr_phys_segments = 0; |
320 | #if defined(CONFIG_BLK_DEV_INTEGRITY) | |
321 | rq->nr_integrity_segments = 0; | |
322 | #endif | |
a892c8d5 | 323 | blk_crypto_rq_set_defaults(rq); |
af76e555 | 324 | /* tag was already set */ |
079076b3 | 325 | WRITE_ONCE(rq->deadline, 0); |
af76e555 | 326 | |
f6be4fb4 JA |
327 | rq->timeout = 0; |
328 | ||
af76e555 CH |
329 | rq->end_io = NULL; |
330 | rq->end_io_data = NULL; | |
af76e555 | 331 | |
7ea4d8a4 | 332 | data->ctx->rq_dispatched[op_is_sync(data->cmd_flags)]++; |
12f5b931 | 333 | refcount_set(&rq->ref, 1); |
7ea4d8a4 CH |
334 | |
335 | if (!op_is_flush(data->cmd_flags)) { | |
336 | struct elevator_queue *e = data->q->elevator; | |
337 | ||
338 | rq->elv.icq = NULL; | |
339 | if (e && e->type->ops.prepare_request) { | |
340 | if (e->type->icq_cache) | |
341 | blk_mq_sched_assign_ioc(rq); | |
342 | ||
343 | e->type->ops.prepare_request(rq); | |
344 | rq->rq_flags |= RQF_ELVPRIV; | |
345 | } | |
346 | } | |
347 | ||
348 | data->hctx->queued++; | |
e4cdf1a1 | 349 | return rq; |
5dee8577 CH |
350 | } |
351 | ||
e6e7abff | 352 | static struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data) |
d2c0d383 | 353 | { |
e6e7abff | 354 | struct request_queue *q = data->q; |
d2c0d383 | 355 | struct elevator_queue *e = q->elevator; |
6f816b4b | 356 | u64 alloc_time_ns = 0; |
600c3b0c | 357 | unsigned int tag; |
d2c0d383 | 358 | |
6f816b4b TH |
359 | /* alloc_time includes depth and tag waits */ |
360 | if (blk_queue_rq_alloc_time(q)) | |
361 | alloc_time_ns = ktime_get_ns(); | |
362 | ||
f9afca4d | 363 | if (data->cmd_flags & REQ_NOWAIT) |
03a07c92 | 364 | data->flags |= BLK_MQ_REQ_NOWAIT; |
d2c0d383 CH |
365 | |
366 | if (e) { | |
d2c0d383 CH |
367 | /* |
368 | * Flush requests are special and go directly to the | |
17a51199 JA |
369 | * dispatch list. Don't include reserved tags in the |
370 | * limiting, as it isn't useful. | |
d2c0d383 | 371 | */ |
f9afca4d JA |
372 | if (!op_is_flush(data->cmd_flags) && |
373 | e->type->ops.limit_depth && | |
17a51199 | 374 | !(data->flags & BLK_MQ_REQ_RESERVED)) |
f9afca4d | 375 | e->type->ops.limit_depth(data->cmd_flags, data); |
d2c0d383 CH |
376 | } |
377 | ||
bf0beec0 | 378 | retry: |
600c3b0c CH |
379 | data->ctx = blk_mq_get_ctx(q); |
380 | data->hctx = blk_mq_map_queue(q, data->cmd_flags, data->ctx); | |
42fdc5e4 | 381 | if (!e) |
600c3b0c CH |
382 | blk_mq_tag_busy(data->hctx); |
383 | ||
bf0beec0 ML |
384 | /* |
385 | * Waiting allocations only fail because of an inactive hctx. In that | |
386 | * case just retry the hctx assignment and tag allocation as CPU hotplug | |
387 | * should have migrated us to an online CPU by now. | |
388 | */ | |
e4cdf1a1 | 389 | tag = blk_mq_get_tag(data); |
bf0beec0 ML |
390 | if (tag == BLK_MQ_NO_TAG) { |
391 | if (data->flags & BLK_MQ_REQ_NOWAIT) | |
392 | return NULL; | |
393 | ||
394 | /* | |
395 | * Give up the CPU and sleep for a random short time to ensure | |
396 | * that thread using a realtime scheduling class are migrated | |
397 | * off the the CPU, and thus off the hctx that is going away. | |
398 | */ | |
399 | msleep(3); | |
400 | goto retry; | |
401 | } | |
7ea4d8a4 | 402 | return blk_mq_rq_ctx_init(data, tag, alloc_time_ns); |
d2c0d383 CH |
403 | } |
404 | ||
cd6ce148 | 405 | struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op, |
9a95e4ef | 406 | blk_mq_req_flags_t flags) |
320ae51f | 407 | { |
e6e7abff CH |
408 | struct blk_mq_alloc_data data = { |
409 | .q = q, | |
410 | .flags = flags, | |
411 | .cmd_flags = op, | |
412 | }; | |
bd166ef1 | 413 | struct request *rq; |
a492f075 | 414 | int ret; |
320ae51f | 415 | |
3a0a5299 | 416 | ret = blk_queue_enter(q, flags); |
a492f075 JL |
417 | if (ret) |
418 | return ERR_PTR(ret); | |
320ae51f | 419 | |
e6e7abff | 420 | rq = __blk_mq_alloc_request(&data); |
bd166ef1 | 421 | if (!rq) |
a5ea5811 | 422 | goto out_queue_exit; |
0c4de0f3 CH |
423 | rq->__data_len = 0; |
424 | rq->__sector = (sector_t) -1; | |
425 | rq->bio = rq->biotail = NULL; | |
320ae51f | 426 | return rq; |
a5ea5811 CH |
427 | out_queue_exit: |
428 | blk_queue_exit(q); | |
429 | return ERR_PTR(-EWOULDBLOCK); | |
320ae51f | 430 | } |
4bb659b1 | 431 | EXPORT_SYMBOL(blk_mq_alloc_request); |
320ae51f | 432 | |
cd6ce148 | 433 | struct request *blk_mq_alloc_request_hctx(struct request_queue *q, |
9a95e4ef | 434 | unsigned int op, blk_mq_req_flags_t flags, unsigned int hctx_idx) |
1f5bd336 | 435 | { |
e6e7abff CH |
436 | struct blk_mq_alloc_data data = { |
437 | .q = q, | |
438 | .flags = flags, | |
439 | .cmd_flags = op, | |
440 | }; | |
600c3b0c | 441 | u64 alloc_time_ns = 0; |
6d2809d5 | 442 | unsigned int cpu; |
600c3b0c | 443 | unsigned int tag; |
1f5bd336 ML |
444 | int ret; |
445 | ||
600c3b0c CH |
446 | /* alloc_time includes depth and tag waits */ |
447 | if (blk_queue_rq_alloc_time(q)) | |
448 | alloc_time_ns = ktime_get_ns(); | |
449 | ||
1f5bd336 ML |
450 | /* |
451 | * If the tag allocator sleeps we could get an allocation for a | |
452 | * different hardware context. No need to complicate the low level | |
453 | * allocator for this for the rare use case of a command tied to | |
454 | * a specific queue. | |
455 | */ | |
600c3b0c | 456 | if (WARN_ON_ONCE(!(flags & (BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED)))) |
1f5bd336 ML |
457 | return ERR_PTR(-EINVAL); |
458 | ||
459 | if (hctx_idx >= q->nr_hw_queues) | |
460 | return ERR_PTR(-EIO); | |
461 | ||
3a0a5299 | 462 | ret = blk_queue_enter(q, flags); |
1f5bd336 ML |
463 | if (ret) |
464 | return ERR_PTR(ret); | |
465 | ||
c8712c6a CH |
466 | /* |
467 | * Check if the hardware context is actually mapped to anything. | |
468 | * If not tell the caller that it should skip this queue. | |
469 | */ | |
a5ea5811 | 470 | ret = -EXDEV; |
e6e7abff CH |
471 | data.hctx = q->queue_hw_ctx[hctx_idx]; |
472 | if (!blk_mq_hw_queue_mapped(data.hctx)) | |
a5ea5811 | 473 | goto out_queue_exit; |
e6e7abff CH |
474 | cpu = cpumask_first_and(data.hctx->cpumask, cpu_online_mask); |
475 | data.ctx = __blk_mq_get_ctx(q, cpu); | |
1f5bd336 | 476 | |
42fdc5e4 | 477 | if (!q->elevator) |
600c3b0c CH |
478 | blk_mq_tag_busy(data.hctx); |
479 | ||
a5ea5811 | 480 | ret = -EWOULDBLOCK; |
600c3b0c CH |
481 | tag = blk_mq_get_tag(&data); |
482 | if (tag == BLK_MQ_NO_TAG) | |
a5ea5811 | 483 | goto out_queue_exit; |
600c3b0c CH |
484 | return blk_mq_rq_ctx_init(&data, tag, alloc_time_ns); |
485 | ||
a5ea5811 CH |
486 | out_queue_exit: |
487 | blk_queue_exit(q); | |
488 | return ERR_PTR(ret); | |
1f5bd336 ML |
489 | } |
490 | EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx); | |
491 | ||
12f5b931 KB |
492 | static void __blk_mq_free_request(struct request *rq) |
493 | { | |
494 | struct request_queue *q = rq->q; | |
495 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
ea4f995e | 496 | struct blk_mq_hw_ctx *hctx = rq->mq_hctx; |
12f5b931 KB |
497 | const int sched_tag = rq->internal_tag; |
498 | ||
a892c8d5 | 499 | blk_crypto_free_request(rq); |
986d413b | 500 | blk_pm_mark_last_busy(rq); |
ea4f995e | 501 | rq->mq_hctx = NULL; |
76647368 | 502 | if (rq->tag != BLK_MQ_NO_TAG) |
cae740a0 | 503 | blk_mq_put_tag(hctx->tags, ctx, rq->tag); |
76647368 | 504 | if (sched_tag != BLK_MQ_NO_TAG) |
cae740a0 | 505 | blk_mq_put_tag(hctx->sched_tags, ctx, sched_tag); |
12f5b931 KB |
506 | blk_mq_sched_restart(hctx); |
507 | blk_queue_exit(q); | |
508 | } | |
509 | ||
6af54051 | 510 | void blk_mq_free_request(struct request *rq) |
320ae51f | 511 | { |
320ae51f | 512 | struct request_queue *q = rq->q; |
6af54051 CH |
513 | struct elevator_queue *e = q->elevator; |
514 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
ea4f995e | 515 | struct blk_mq_hw_ctx *hctx = rq->mq_hctx; |
6af54051 | 516 | |
5bbf4e5a | 517 | if (rq->rq_flags & RQF_ELVPRIV) { |
f9cd4bfe JA |
518 | if (e && e->type->ops.finish_request) |
519 | e->type->ops.finish_request(rq); | |
6af54051 CH |
520 | if (rq->elv.icq) { |
521 | put_io_context(rq->elv.icq->ioc); | |
522 | rq->elv.icq = NULL; | |
523 | } | |
524 | } | |
320ae51f | 525 | |
6af54051 | 526 | ctx->rq_completed[rq_is_sync(rq)]++; |
e8064021 | 527 | if (rq->rq_flags & RQF_MQ_INFLIGHT) |
0d2602ca | 528 | atomic_dec(&hctx->nr_active); |
87760e5e | 529 | |
7beb2f84 JA |
530 | if (unlikely(laptop_mode && !blk_rq_is_passthrough(rq))) |
531 | laptop_io_completion(q->backing_dev_info); | |
532 | ||
a7905043 | 533 | rq_qos_done(q, rq); |
0d2602ca | 534 | |
12f5b931 KB |
535 | WRITE_ONCE(rq->state, MQ_RQ_IDLE); |
536 | if (refcount_dec_and_test(&rq->ref)) | |
537 | __blk_mq_free_request(rq); | |
320ae51f | 538 | } |
1a3b595a | 539 | EXPORT_SYMBOL_GPL(blk_mq_free_request); |
320ae51f | 540 | |
2a842aca | 541 | inline void __blk_mq_end_request(struct request *rq, blk_status_t error) |
320ae51f | 542 | { |
fe1f4526 JA |
543 | u64 now = 0; |
544 | ||
545 | if (blk_mq_need_time_stamp(rq)) | |
546 | now = ktime_get_ns(); | |
522a7775 | 547 | |
4bc6339a OS |
548 | if (rq->rq_flags & RQF_STATS) { |
549 | blk_mq_poll_stats_start(rq->q); | |
522a7775 | 550 | blk_stat_add(rq, now); |
4bc6339a OS |
551 | } |
552 | ||
76647368 | 553 | if (rq->internal_tag != BLK_MQ_NO_TAG) |
ed88660a OS |
554 | blk_mq_sched_completed_request(rq, now); |
555 | ||
522a7775 | 556 | blk_account_io_done(rq, now); |
0d11e6ac | 557 | |
91b63639 | 558 | if (rq->end_io) { |
a7905043 | 559 | rq_qos_done(rq->q, rq); |
320ae51f | 560 | rq->end_io(rq, error); |
91b63639 | 561 | } else { |
320ae51f | 562 | blk_mq_free_request(rq); |
91b63639 | 563 | } |
320ae51f | 564 | } |
c8a446ad | 565 | EXPORT_SYMBOL(__blk_mq_end_request); |
63151a44 | 566 | |
2a842aca | 567 | void blk_mq_end_request(struct request *rq, blk_status_t error) |
63151a44 CH |
568 | { |
569 | if (blk_update_request(rq, error, blk_rq_bytes(rq))) | |
570 | BUG(); | |
c8a446ad | 571 | __blk_mq_end_request(rq, error); |
63151a44 | 572 | } |
c8a446ad | 573 | EXPORT_SYMBOL(blk_mq_end_request); |
320ae51f | 574 | |
c3077b5d CH |
575 | /* |
576 | * Softirq action handler - move entries to local list and loop over them | |
577 | * while passing them to the queue registered handler. | |
578 | */ | |
579 | static __latent_entropy void blk_done_softirq(struct softirq_action *h) | |
580 | { | |
581 | struct list_head *cpu_list, local_list; | |
582 | ||
583 | local_irq_disable(); | |
584 | cpu_list = this_cpu_ptr(&blk_cpu_done); | |
585 | list_replace_init(cpu_list, &local_list); | |
586 | local_irq_enable(); | |
587 | ||
588 | while (!list_empty(&local_list)) { | |
589 | struct request *rq; | |
590 | ||
591 | rq = list_entry(local_list.next, struct request, ipi_list); | |
592 | list_del_init(&rq->ipi_list); | |
593 | rq->q->mq_ops->complete(rq); | |
594 | } | |
595 | } | |
596 | ||
115243f5 | 597 | static void blk_mq_trigger_softirq(struct request *rq) |
c3077b5d | 598 | { |
d391a7a3 CH |
599 | struct list_head *list; |
600 | unsigned long flags; | |
c3077b5d | 601 | |
d391a7a3 CH |
602 | local_irq_save(flags); |
603 | list = this_cpu_ptr(&blk_cpu_done); | |
c3077b5d CH |
604 | list_add_tail(&rq->ipi_list, list); |
605 | ||
115243f5 CH |
606 | /* |
607 | * If the list only contains our just added request, signal a raise of | |
608 | * the softirq. If there are already entries there, someone already | |
609 | * raised the irq but it hasn't run yet. | |
610 | */ | |
c3077b5d CH |
611 | if (list->next == &rq->ipi_list) |
612 | raise_softirq_irqoff(BLOCK_SOFTIRQ); | |
d391a7a3 | 613 | local_irq_restore(flags); |
115243f5 CH |
614 | } |
615 | ||
c3077b5d CH |
616 | static int blk_softirq_cpu_dead(unsigned int cpu) |
617 | { | |
618 | /* | |
619 | * If a CPU goes away, splice its entries to the current CPU | |
620 | * and trigger a run of the softirq | |
621 | */ | |
622 | local_irq_disable(); | |
623 | list_splice_init(&per_cpu(blk_cpu_done, cpu), | |
624 | this_cpu_ptr(&blk_cpu_done)); | |
625 | raise_softirq_irqoff(BLOCK_SOFTIRQ); | |
626 | local_irq_enable(); | |
627 | ||
628 | return 0; | |
629 | } | |
630 | ||
40d09b53 CH |
631 | |
632 | static void __blk_mq_complete_request_remote(void *data) | |
c3077b5d | 633 | { |
40d09b53 CH |
634 | struct request *rq = data; |
635 | ||
c3077b5d | 636 | /* |
d391a7a3 CH |
637 | * For most of single queue controllers, there is only one irq vector |
638 | * for handling I/O completion, and the only irq's affinity is set | |
639 | * to all possible CPUs. On most of ARCHs, this affinity means the irq | |
640 | * is handled on one specific CPU. | |
641 | * | |
642 | * So complete I/O requests in softirq context in case of single queue | |
643 | * devices to avoid degrading I/O performance due to irqsoff latency. | |
c3077b5d | 644 | */ |
d391a7a3 CH |
645 | if (rq->q->nr_hw_queues == 1) |
646 | blk_mq_trigger_softirq(rq); | |
647 | else | |
648 | rq->q->mq_ops->complete(rq); | |
c3077b5d CH |
649 | } |
650 | ||
96339526 CH |
651 | static inline bool blk_mq_complete_need_ipi(struct request *rq) |
652 | { | |
653 | int cpu = raw_smp_processor_id(); | |
654 | ||
655 | if (!IS_ENABLED(CONFIG_SMP) || | |
656 | !test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) | |
657 | return false; | |
658 | ||
659 | /* same CPU or cache domain? Complete locally */ | |
660 | if (cpu == rq->mq_ctx->cpu || | |
661 | (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags) && | |
662 | cpus_share_cache(cpu, rq->mq_ctx->cpu))) | |
663 | return false; | |
664 | ||
665 | /* don't try to IPI to an offline CPU */ | |
666 | return cpu_online(rq->mq_ctx->cpu); | |
667 | } | |
668 | ||
40d09b53 | 669 | bool blk_mq_complete_request_remote(struct request *rq) |
320ae51f | 670 | { |
af78ff7c | 671 | WRITE_ONCE(rq->state, MQ_RQ_COMPLETE); |
6aab1da6 | 672 | |
36a3df5a ML |
673 | blk_mq_put_driver_tag(rq); |
674 | ||
6aab1da6 CH |
675 | /* |
676 | * For a polled request, always complete locallly, it's pointless | |
677 | * to redirect the completion. | |
678 | */ | |
40d09b53 CH |
679 | if (rq->cmd_flags & REQ_HIPRI) |
680 | return false; | |
320ae51f | 681 | |
96339526 | 682 | if (blk_mq_complete_need_ipi(rq)) { |
30a91cb4 | 683 | rq->csd.func = __blk_mq_complete_request_remote; |
3d6efbf6 CH |
684 | rq->csd.info = rq; |
685 | rq->csd.flags = 0; | |
96339526 | 686 | smp_call_function_single_async(rq->mq_ctx->cpu, &rq->csd); |
3d6efbf6 | 687 | } else { |
40d09b53 CH |
688 | if (rq->q->nr_hw_queues > 1) |
689 | return false; | |
690 | blk_mq_trigger_softirq(rq); | |
3d6efbf6 | 691 | } |
40d09b53 CH |
692 | |
693 | return true; | |
694 | } | |
695 | EXPORT_SYMBOL_GPL(blk_mq_complete_request_remote); | |
696 | ||
697 | /** | |
698 | * blk_mq_complete_request - end I/O on a request | |
699 | * @rq: the request being processed | |
700 | * | |
701 | * Description: | |
702 | * Complete a request by scheduling the ->complete_rq operation. | |
703 | **/ | |
704 | void blk_mq_complete_request(struct request *rq) | |
705 | { | |
706 | if (!blk_mq_complete_request_remote(rq)) | |
707 | rq->q->mq_ops->complete(rq); | |
320ae51f | 708 | } |
15f73f5b | 709 | EXPORT_SYMBOL(blk_mq_complete_request); |
30a91cb4 | 710 | |
04ced159 | 711 | static void hctx_unlock(struct blk_mq_hw_ctx *hctx, int srcu_idx) |
b7435db8 | 712 | __releases(hctx->srcu) |
04ced159 JA |
713 | { |
714 | if (!(hctx->flags & BLK_MQ_F_BLOCKING)) | |
715 | rcu_read_unlock(); | |
716 | else | |
05707b64 | 717 | srcu_read_unlock(hctx->srcu, srcu_idx); |
04ced159 JA |
718 | } |
719 | ||
720 | static void hctx_lock(struct blk_mq_hw_ctx *hctx, int *srcu_idx) | |
b7435db8 | 721 | __acquires(hctx->srcu) |
04ced159 | 722 | { |
08b5a6e2 JA |
723 | if (!(hctx->flags & BLK_MQ_F_BLOCKING)) { |
724 | /* shut up gcc false positive */ | |
725 | *srcu_idx = 0; | |
04ced159 | 726 | rcu_read_lock(); |
08b5a6e2 | 727 | } else |
05707b64 | 728 | *srcu_idx = srcu_read_lock(hctx->srcu); |
04ced159 JA |
729 | } |
730 | ||
105663f7 AA |
731 | /** |
732 | * blk_mq_start_request - Start processing a request | |
733 | * @rq: Pointer to request to be started | |
734 | * | |
735 | * Function used by device drivers to notify the block layer that a request | |
736 | * is going to be processed now, so blk layer can do proper initializations | |
737 | * such as starting the timeout timer. | |
738 | */ | |
e2490073 | 739 | void blk_mq_start_request(struct request *rq) |
320ae51f JA |
740 | { |
741 | struct request_queue *q = rq->q; | |
742 | ||
743 | trace_block_rq_issue(q, rq); | |
744 | ||
cf43e6be | 745 | if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags)) { |
544ccc8d | 746 | rq->io_start_time_ns = ktime_get_ns(); |
3d244306 | 747 | rq->stats_sectors = blk_rq_sectors(rq); |
cf43e6be | 748 | rq->rq_flags |= RQF_STATS; |
a7905043 | 749 | rq_qos_issue(q, rq); |
cf43e6be JA |
750 | } |
751 | ||
1d9bd516 | 752 | WARN_ON_ONCE(blk_mq_rq_state(rq) != MQ_RQ_IDLE); |
538b7534 | 753 | |
1d9bd516 | 754 | blk_add_timer(rq); |
12f5b931 | 755 | WRITE_ONCE(rq->state, MQ_RQ_IN_FLIGHT); |
49f5baa5 | 756 | |
54d4e6ab MG |
757 | #ifdef CONFIG_BLK_DEV_INTEGRITY |
758 | if (blk_integrity_rq(rq) && req_op(rq) == REQ_OP_WRITE) | |
759 | q->integrity.profile->prepare_fn(rq); | |
760 | #endif | |
320ae51f | 761 | } |
e2490073 | 762 | EXPORT_SYMBOL(blk_mq_start_request); |
320ae51f | 763 | |
ed0791b2 | 764 | static void __blk_mq_requeue_request(struct request *rq) |
320ae51f JA |
765 | { |
766 | struct request_queue *q = rq->q; | |
767 | ||
923218f6 ML |
768 | blk_mq_put_driver_tag(rq); |
769 | ||
320ae51f | 770 | trace_block_rq_requeue(q, rq); |
a7905043 | 771 | rq_qos_requeue(q, rq); |
49f5baa5 | 772 | |
12f5b931 KB |
773 | if (blk_mq_request_started(rq)) { |
774 | WRITE_ONCE(rq->state, MQ_RQ_IDLE); | |
da661267 | 775 | rq->rq_flags &= ~RQF_TIMED_OUT; |
e2490073 | 776 | } |
320ae51f JA |
777 | } |
778 | ||
2b053aca | 779 | void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list) |
ed0791b2 | 780 | { |
ed0791b2 | 781 | __blk_mq_requeue_request(rq); |
ed0791b2 | 782 | |
105976f5 ML |
783 | /* this request will be re-inserted to io scheduler queue */ |
784 | blk_mq_sched_requeue_request(rq); | |
785 | ||
7d692330 | 786 | BUG_ON(!list_empty(&rq->queuelist)); |
2b053aca | 787 | blk_mq_add_to_requeue_list(rq, true, kick_requeue_list); |
ed0791b2 CH |
788 | } |
789 | EXPORT_SYMBOL(blk_mq_requeue_request); | |
790 | ||
6fca6a61 CH |
791 | static void blk_mq_requeue_work(struct work_struct *work) |
792 | { | |
793 | struct request_queue *q = | |
2849450a | 794 | container_of(work, struct request_queue, requeue_work.work); |
6fca6a61 CH |
795 | LIST_HEAD(rq_list); |
796 | struct request *rq, *next; | |
6fca6a61 | 797 | |
18e9781d | 798 | spin_lock_irq(&q->requeue_lock); |
6fca6a61 | 799 | list_splice_init(&q->requeue_list, &rq_list); |
18e9781d | 800 | spin_unlock_irq(&q->requeue_lock); |
6fca6a61 CH |
801 | |
802 | list_for_each_entry_safe(rq, next, &rq_list, queuelist) { | |
aef1897c | 803 | if (!(rq->rq_flags & (RQF_SOFTBARRIER | RQF_DONTPREP))) |
6fca6a61 CH |
804 | continue; |
805 | ||
e8064021 | 806 | rq->rq_flags &= ~RQF_SOFTBARRIER; |
6fca6a61 | 807 | list_del_init(&rq->queuelist); |
aef1897c JW |
808 | /* |
809 | * If RQF_DONTPREP, rq has contained some driver specific | |
810 | * data, so insert it to hctx dispatch list to avoid any | |
811 | * merge. | |
812 | */ | |
813 | if (rq->rq_flags & RQF_DONTPREP) | |
01e99aec | 814 | blk_mq_request_bypass_insert(rq, false, false); |
aef1897c JW |
815 | else |
816 | blk_mq_sched_insert_request(rq, true, false, false); | |
6fca6a61 CH |
817 | } |
818 | ||
819 | while (!list_empty(&rq_list)) { | |
820 | rq = list_entry(rq_list.next, struct request, queuelist); | |
821 | list_del_init(&rq->queuelist); | |
9e97d295 | 822 | blk_mq_sched_insert_request(rq, false, false, false); |
6fca6a61 CH |
823 | } |
824 | ||
52d7f1b5 | 825 | blk_mq_run_hw_queues(q, false); |
6fca6a61 CH |
826 | } |
827 | ||
2b053aca BVA |
828 | void blk_mq_add_to_requeue_list(struct request *rq, bool at_head, |
829 | bool kick_requeue_list) | |
6fca6a61 CH |
830 | { |
831 | struct request_queue *q = rq->q; | |
832 | unsigned long flags; | |
833 | ||
834 | /* | |
835 | * We abuse this flag that is otherwise used by the I/O scheduler to | |
ff821d27 | 836 | * request head insertion from the workqueue. |
6fca6a61 | 837 | */ |
e8064021 | 838 | BUG_ON(rq->rq_flags & RQF_SOFTBARRIER); |
6fca6a61 CH |
839 | |
840 | spin_lock_irqsave(&q->requeue_lock, flags); | |
841 | if (at_head) { | |
e8064021 | 842 | rq->rq_flags |= RQF_SOFTBARRIER; |
6fca6a61 CH |
843 | list_add(&rq->queuelist, &q->requeue_list); |
844 | } else { | |
845 | list_add_tail(&rq->queuelist, &q->requeue_list); | |
846 | } | |
847 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
2b053aca BVA |
848 | |
849 | if (kick_requeue_list) | |
850 | blk_mq_kick_requeue_list(q); | |
6fca6a61 | 851 | } |
6fca6a61 CH |
852 | |
853 | void blk_mq_kick_requeue_list(struct request_queue *q) | |
854 | { | |
ae943d20 | 855 | kblockd_mod_delayed_work_on(WORK_CPU_UNBOUND, &q->requeue_work, 0); |
6fca6a61 CH |
856 | } |
857 | EXPORT_SYMBOL(blk_mq_kick_requeue_list); | |
858 | ||
2849450a MS |
859 | void blk_mq_delay_kick_requeue_list(struct request_queue *q, |
860 | unsigned long msecs) | |
861 | { | |
d4acf365 BVA |
862 | kblockd_mod_delayed_work_on(WORK_CPU_UNBOUND, &q->requeue_work, |
863 | msecs_to_jiffies(msecs)); | |
2849450a MS |
864 | } |
865 | EXPORT_SYMBOL(blk_mq_delay_kick_requeue_list); | |
866 | ||
0e62f51f JA |
867 | struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag) |
868 | { | |
88c7b2b7 JA |
869 | if (tag < tags->nr_tags) { |
870 | prefetch(tags->rqs[tag]); | |
4ee86bab | 871 | return tags->rqs[tag]; |
88c7b2b7 | 872 | } |
4ee86bab HR |
873 | |
874 | return NULL; | |
24d2f903 CH |
875 | } |
876 | EXPORT_SYMBOL(blk_mq_tag_to_rq); | |
877 | ||
3c94d83c JA |
878 | static bool blk_mq_rq_inflight(struct blk_mq_hw_ctx *hctx, struct request *rq, |
879 | void *priv, bool reserved) | |
ae879912 JA |
880 | { |
881 | /* | |
3c94d83c JA |
882 | * If we find a request that is inflight and the queue matches, |
883 | * we know the queue is busy. Return false to stop the iteration. | |
ae879912 | 884 | */ |
3c94d83c | 885 | if (rq->state == MQ_RQ_IN_FLIGHT && rq->q == hctx->queue) { |
ae879912 JA |
886 | bool *busy = priv; |
887 | ||
888 | *busy = true; | |
889 | return false; | |
890 | } | |
891 | ||
892 | return true; | |
893 | } | |
894 | ||
3c94d83c | 895 | bool blk_mq_queue_inflight(struct request_queue *q) |
ae879912 JA |
896 | { |
897 | bool busy = false; | |
898 | ||
3c94d83c | 899 | blk_mq_queue_tag_busy_iter(q, blk_mq_rq_inflight, &busy); |
ae879912 JA |
900 | return busy; |
901 | } | |
3c94d83c | 902 | EXPORT_SYMBOL_GPL(blk_mq_queue_inflight); |
ae879912 | 903 | |
358f70da | 904 | static void blk_mq_rq_timed_out(struct request *req, bool reserved) |
320ae51f | 905 | { |
da661267 | 906 | req->rq_flags |= RQF_TIMED_OUT; |
d1210d5a CH |
907 | if (req->q->mq_ops->timeout) { |
908 | enum blk_eh_timer_return ret; | |
909 | ||
910 | ret = req->q->mq_ops->timeout(req, reserved); | |
911 | if (ret == BLK_EH_DONE) | |
912 | return; | |
913 | WARN_ON_ONCE(ret != BLK_EH_RESET_TIMER); | |
46f92d42 | 914 | } |
d1210d5a CH |
915 | |
916 | blk_add_timer(req); | |
87ee7b11 | 917 | } |
5b3f25fc | 918 | |
12f5b931 | 919 | static bool blk_mq_req_expired(struct request *rq, unsigned long *next) |
81481eb4 | 920 | { |
12f5b931 | 921 | unsigned long deadline; |
87ee7b11 | 922 | |
12f5b931 KB |
923 | if (blk_mq_rq_state(rq) != MQ_RQ_IN_FLIGHT) |
924 | return false; | |
da661267 CH |
925 | if (rq->rq_flags & RQF_TIMED_OUT) |
926 | return false; | |
a7af0af3 | 927 | |
079076b3 | 928 | deadline = READ_ONCE(rq->deadline); |
12f5b931 KB |
929 | if (time_after_eq(jiffies, deadline)) |
930 | return true; | |
a7af0af3 | 931 | |
12f5b931 KB |
932 | if (*next == 0) |
933 | *next = deadline; | |
934 | else if (time_after(*next, deadline)) | |
935 | *next = deadline; | |
936 | return false; | |
87ee7b11 JA |
937 | } |
938 | ||
7baa8572 | 939 | static bool blk_mq_check_expired(struct blk_mq_hw_ctx *hctx, |
1d9bd516 TH |
940 | struct request *rq, void *priv, bool reserved) |
941 | { | |
12f5b931 KB |
942 | unsigned long *next = priv; |
943 | ||
944 | /* | |
945 | * Just do a quick check if it is expired before locking the request in | |
946 | * so we're not unnecessarilly synchronizing across CPUs. | |
947 | */ | |
948 | if (!blk_mq_req_expired(rq, next)) | |
7baa8572 | 949 | return true; |
12f5b931 KB |
950 | |
951 | /* | |
952 | * We have reason to believe the request may be expired. Take a | |
953 | * reference on the request to lock this request lifetime into its | |
954 | * currently allocated context to prevent it from being reallocated in | |
955 | * the event the completion by-passes this timeout handler. | |
956 | * | |
957 | * If the reference was already released, then the driver beat the | |
958 | * timeout handler to posting a natural completion. | |
959 | */ | |
960 | if (!refcount_inc_not_zero(&rq->ref)) | |
7baa8572 | 961 | return true; |
12f5b931 | 962 | |
1d9bd516 | 963 | /* |
12f5b931 KB |
964 | * The request is now locked and cannot be reallocated underneath the |
965 | * timeout handler's processing. Re-verify this exact request is truly | |
966 | * expired; if it is not expired, then the request was completed and | |
967 | * reallocated as a new request. | |
1d9bd516 | 968 | */ |
12f5b931 | 969 | if (blk_mq_req_expired(rq, next)) |
1d9bd516 | 970 | blk_mq_rq_timed_out(rq, reserved); |
8d699663 YY |
971 | |
972 | if (is_flush_rq(rq, hctx)) | |
973 | rq->end_io(rq, 0); | |
974 | else if (refcount_dec_and_test(&rq->ref)) | |
12f5b931 | 975 | __blk_mq_free_request(rq); |
7baa8572 JA |
976 | |
977 | return true; | |
1d9bd516 TH |
978 | } |
979 | ||
287922eb | 980 | static void blk_mq_timeout_work(struct work_struct *work) |
320ae51f | 981 | { |
287922eb CH |
982 | struct request_queue *q = |
983 | container_of(work, struct request_queue, timeout_work); | |
12f5b931 | 984 | unsigned long next = 0; |
1d9bd516 | 985 | struct blk_mq_hw_ctx *hctx; |
81481eb4 | 986 | int i; |
320ae51f | 987 | |
71f79fb3 GKB |
988 | /* A deadlock might occur if a request is stuck requiring a |
989 | * timeout at the same time a queue freeze is waiting | |
990 | * completion, since the timeout code would not be able to | |
991 | * acquire the queue reference here. | |
992 | * | |
993 | * That's why we don't use blk_queue_enter here; instead, we use | |
994 | * percpu_ref_tryget directly, because we need to be able to | |
995 | * obtain a reference even in the short window between the queue | |
996 | * starting to freeze, by dropping the first reference in | |
1671d522 | 997 | * blk_freeze_queue_start, and the moment the last request is |
71f79fb3 GKB |
998 | * consumed, marked by the instant q_usage_counter reaches |
999 | * zero. | |
1000 | */ | |
1001 | if (!percpu_ref_tryget(&q->q_usage_counter)) | |
287922eb CH |
1002 | return; |
1003 | ||
12f5b931 | 1004 | blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &next); |
320ae51f | 1005 | |
12f5b931 KB |
1006 | if (next != 0) { |
1007 | mod_timer(&q->timeout, next); | |
0d2602ca | 1008 | } else { |
fcd36c36 BVA |
1009 | /* |
1010 | * Request timeouts are handled as a forward rolling timer. If | |
1011 | * we end up here it means that no requests are pending and | |
1012 | * also that no request has been pending for a while. Mark | |
1013 | * each hctx as idle. | |
1014 | */ | |
f054b56c ML |
1015 | queue_for_each_hw_ctx(q, hctx, i) { |
1016 | /* the hctx may be unmapped, so check it here */ | |
1017 | if (blk_mq_hw_queue_mapped(hctx)) | |
1018 | blk_mq_tag_idle(hctx); | |
1019 | } | |
0d2602ca | 1020 | } |
287922eb | 1021 | blk_queue_exit(q); |
320ae51f JA |
1022 | } |
1023 | ||
88459642 OS |
1024 | struct flush_busy_ctx_data { |
1025 | struct blk_mq_hw_ctx *hctx; | |
1026 | struct list_head *list; | |
1027 | }; | |
1028 | ||
1029 | static bool flush_busy_ctx(struct sbitmap *sb, unsigned int bitnr, void *data) | |
1030 | { | |
1031 | struct flush_busy_ctx_data *flush_data = data; | |
1032 | struct blk_mq_hw_ctx *hctx = flush_data->hctx; | |
1033 | struct blk_mq_ctx *ctx = hctx->ctxs[bitnr]; | |
c16d6b5a | 1034 | enum hctx_type type = hctx->type; |
88459642 | 1035 | |
88459642 | 1036 | spin_lock(&ctx->lock); |
c16d6b5a | 1037 | list_splice_tail_init(&ctx->rq_lists[type], flush_data->list); |
e9a99a63 | 1038 | sbitmap_clear_bit(sb, bitnr); |
88459642 OS |
1039 | spin_unlock(&ctx->lock); |
1040 | return true; | |
1041 | } | |
1042 | ||
1429d7c9 JA |
1043 | /* |
1044 | * Process software queues that have been marked busy, splicing them | |
1045 | * to the for-dispatch | |
1046 | */ | |
2c3ad667 | 1047 | void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) |
1429d7c9 | 1048 | { |
88459642 OS |
1049 | struct flush_busy_ctx_data data = { |
1050 | .hctx = hctx, | |
1051 | .list = list, | |
1052 | }; | |
1429d7c9 | 1053 | |
88459642 | 1054 | sbitmap_for_each_set(&hctx->ctx_map, flush_busy_ctx, &data); |
1429d7c9 | 1055 | } |
2c3ad667 | 1056 | EXPORT_SYMBOL_GPL(blk_mq_flush_busy_ctxs); |
1429d7c9 | 1057 | |
b347689f ML |
1058 | struct dispatch_rq_data { |
1059 | struct blk_mq_hw_ctx *hctx; | |
1060 | struct request *rq; | |
1061 | }; | |
1062 | ||
1063 | static bool dispatch_rq_from_ctx(struct sbitmap *sb, unsigned int bitnr, | |
1064 | void *data) | |
1065 | { | |
1066 | struct dispatch_rq_data *dispatch_data = data; | |
1067 | struct blk_mq_hw_ctx *hctx = dispatch_data->hctx; | |
1068 | struct blk_mq_ctx *ctx = hctx->ctxs[bitnr]; | |
c16d6b5a | 1069 | enum hctx_type type = hctx->type; |
b347689f ML |
1070 | |
1071 | spin_lock(&ctx->lock); | |
c16d6b5a ML |
1072 | if (!list_empty(&ctx->rq_lists[type])) { |
1073 | dispatch_data->rq = list_entry_rq(ctx->rq_lists[type].next); | |
b347689f | 1074 | list_del_init(&dispatch_data->rq->queuelist); |
c16d6b5a | 1075 | if (list_empty(&ctx->rq_lists[type])) |
b347689f ML |
1076 | sbitmap_clear_bit(sb, bitnr); |
1077 | } | |
1078 | spin_unlock(&ctx->lock); | |
1079 | ||
1080 | return !dispatch_data->rq; | |
1081 | } | |
1082 | ||
1083 | struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx, | |
1084 | struct blk_mq_ctx *start) | |
1085 | { | |
f31967f0 | 1086 | unsigned off = start ? start->index_hw[hctx->type] : 0; |
b347689f ML |
1087 | struct dispatch_rq_data data = { |
1088 | .hctx = hctx, | |
1089 | .rq = NULL, | |
1090 | }; | |
1091 | ||
1092 | __sbitmap_for_each_set(&hctx->ctx_map, off, | |
1093 | dispatch_rq_from_ctx, &data); | |
1094 | ||
1095 | return data.rq; | |
1096 | } | |
1097 | ||
703fd1c0 JA |
1098 | static inline unsigned int queued_to_index(unsigned int queued) |
1099 | { | |
1100 | if (!queued) | |
1101 | return 0; | |
1429d7c9 | 1102 | |
703fd1c0 | 1103 | return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1); |
1429d7c9 JA |
1104 | } |
1105 | ||
eb619fdb JA |
1106 | static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode, |
1107 | int flags, void *key) | |
da55f2cc OS |
1108 | { |
1109 | struct blk_mq_hw_ctx *hctx; | |
1110 | ||
1111 | hctx = container_of(wait, struct blk_mq_hw_ctx, dispatch_wait); | |
1112 | ||
5815839b | 1113 | spin_lock(&hctx->dispatch_wait_lock); |
e8618575 JA |
1114 | if (!list_empty(&wait->entry)) { |
1115 | struct sbitmap_queue *sbq; | |
1116 | ||
1117 | list_del_init(&wait->entry); | |
1118 | sbq = &hctx->tags->bitmap_tags; | |
1119 | atomic_dec(&sbq->ws_active); | |
1120 | } | |
5815839b ML |
1121 | spin_unlock(&hctx->dispatch_wait_lock); |
1122 | ||
da55f2cc OS |
1123 | blk_mq_run_hw_queue(hctx, true); |
1124 | return 1; | |
1125 | } | |
1126 | ||
f906a6a0 JA |
1127 | /* |
1128 | * Mark us waiting for a tag. For shared tags, this involves hooking us into | |
ee3e4de5 BVA |
1129 | * the tag wakeups. For non-shared tags, we can simply mark us needing a |
1130 | * restart. For both cases, take care to check the condition again after | |
f906a6a0 JA |
1131 | * marking us as waiting. |
1132 | */ | |
2278d69f | 1133 | static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx *hctx, |
f906a6a0 | 1134 | struct request *rq) |
da55f2cc | 1135 | { |
e8618575 | 1136 | struct sbitmap_queue *sbq = &hctx->tags->bitmap_tags; |
5815839b | 1137 | struct wait_queue_head *wq; |
f906a6a0 JA |
1138 | wait_queue_entry_t *wait; |
1139 | bool ret; | |
da55f2cc | 1140 | |
2278d69f | 1141 | if (!(hctx->flags & BLK_MQ_F_TAG_SHARED)) { |
684b7324 | 1142 | blk_mq_sched_mark_restart_hctx(hctx); |
f906a6a0 | 1143 | |
c27d53fb BVA |
1144 | /* |
1145 | * It's possible that a tag was freed in the window between the | |
1146 | * allocation failure and adding the hardware queue to the wait | |
1147 | * queue. | |
1148 | * | |
1149 | * Don't clear RESTART here, someone else could have set it. | |
1150 | * At most this will cost an extra queue run. | |
1151 | */ | |
8ab6bb9e | 1152 | return blk_mq_get_driver_tag(rq); |
eb619fdb | 1153 | } |
eb619fdb | 1154 | |
2278d69f | 1155 | wait = &hctx->dispatch_wait; |
c27d53fb BVA |
1156 | if (!list_empty_careful(&wait->entry)) |
1157 | return false; | |
1158 | ||
e8618575 | 1159 | wq = &bt_wait_ptr(sbq, hctx)->wait; |
5815839b ML |
1160 | |
1161 | spin_lock_irq(&wq->lock); | |
1162 | spin_lock(&hctx->dispatch_wait_lock); | |
c27d53fb | 1163 | if (!list_empty(&wait->entry)) { |
5815839b ML |
1164 | spin_unlock(&hctx->dispatch_wait_lock); |
1165 | spin_unlock_irq(&wq->lock); | |
c27d53fb | 1166 | return false; |
eb619fdb JA |
1167 | } |
1168 | ||
e8618575 | 1169 | atomic_inc(&sbq->ws_active); |
5815839b ML |
1170 | wait->flags &= ~WQ_FLAG_EXCLUSIVE; |
1171 | __add_wait_queue(wq, wait); | |
c27d53fb | 1172 | |
da55f2cc | 1173 | /* |
eb619fdb JA |
1174 | * It's possible that a tag was freed in the window between the |
1175 | * allocation failure and adding the hardware queue to the wait | |
1176 | * queue. | |
da55f2cc | 1177 | */ |
8ab6bb9e | 1178 | ret = blk_mq_get_driver_tag(rq); |
c27d53fb | 1179 | if (!ret) { |
5815839b ML |
1180 | spin_unlock(&hctx->dispatch_wait_lock); |
1181 | spin_unlock_irq(&wq->lock); | |
c27d53fb | 1182 | return false; |
eb619fdb | 1183 | } |
c27d53fb BVA |
1184 | |
1185 | /* | |
1186 | * We got a tag, remove ourselves from the wait queue to ensure | |
1187 | * someone else gets the wakeup. | |
1188 | */ | |
c27d53fb | 1189 | list_del_init(&wait->entry); |
e8618575 | 1190 | atomic_dec(&sbq->ws_active); |
5815839b ML |
1191 | spin_unlock(&hctx->dispatch_wait_lock); |
1192 | spin_unlock_irq(&wq->lock); | |
c27d53fb BVA |
1193 | |
1194 | return true; | |
da55f2cc OS |
1195 | } |
1196 | ||
6e768717 ML |
1197 | #define BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT 8 |
1198 | #define BLK_MQ_DISPATCH_BUSY_EWMA_FACTOR 4 | |
1199 | /* | |
1200 | * Update dispatch busy with the Exponential Weighted Moving Average(EWMA): | |
1201 | * - EWMA is one simple way to compute running average value | |
1202 | * - weight(7/8 and 1/8) is applied so that it can decrease exponentially | |
1203 | * - take 4 as factor for avoiding to get too small(0) result, and this | |
1204 | * factor doesn't matter because EWMA decreases exponentially | |
1205 | */ | |
1206 | static void blk_mq_update_dispatch_busy(struct blk_mq_hw_ctx *hctx, bool busy) | |
1207 | { | |
1208 | unsigned int ewma; | |
1209 | ||
1210 | if (hctx->queue->elevator) | |
1211 | return; | |
1212 | ||
1213 | ewma = hctx->dispatch_busy; | |
1214 | ||
1215 | if (!ewma && !busy) | |
1216 | return; | |
1217 | ||
1218 | ewma *= BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT - 1; | |
1219 | if (busy) | |
1220 | ewma += 1 << BLK_MQ_DISPATCH_BUSY_EWMA_FACTOR; | |
1221 | ewma /= BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT; | |
1222 | ||
1223 | hctx->dispatch_busy = ewma; | |
1224 | } | |
1225 | ||
86ff7c2a ML |
1226 | #define BLK_MQ_RESOURCE_DELAY 3 /* ms units */ |
1227 | ||
c92a4103 JT |
1228 | static void blk_mq_handle_dev_resource(struct request *rq, |
1229 | struct list_head *list) | |
1230 | { | |
1231 | struct request *next = | |
1232 | list_first_entry_or_null(list, struct request, queuelist); | |
1233 | ||
1234 | /* | |
1235 | * If an I/O scheduler has been configured and we got a driver tag for | |
1236 | * the next request already, free it. | |
1237 | */ | |
1238 | if (next) | |
1239 | blk_mq_put_driver_tag(next); | |
1240 | ||
1241 | list_add(&rq->queuelist, list); | |
1242 | __blk_mq_requeue_request(rq); | |
1243 | } | |
1244 | ||
0512a75b KB |
1245 | static void blk_mq_handle_zone_resource(struct request *rq, |
1246 | struct list_head *zone_list) | |
1247 | { | |
1248 | /* | |
1249 | * If we end up here it is because we cannot dispatch a request to a | |
1250 | * specific zone due to LLD level zone-write locking or other zone | |
1251 | * related resource not being available. In this case, set the request | |
1252 | * aside in zone_list for retrying it later. | |
1253 | */ | |
1254 | list_add(&rq->queuelist, zone_list); | |
1255 | __blk_mq_requeue_request(rq); | |
1256 | } | |
1257 | ||
1f57f8d4 JA |
1258 | /* |
1259 | * Returns true if we did some work AND can potentially do more. | |
1260 | */ | |
de148297 | 1261 | bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list, |
eb619fdb | 1262 | bool got_budget) |
320ae51f | 1263 | { |
81380ca1 | 1264 | struct blk_mq_hw_ctx *hctx; |
6d6f167c | 1265 | struct request *rq, *nxt; |
eb619fdb | 1266 | bool no_tag = false; |
fc17b653 | 1267 | int errors, queued; |
86ff7c2a | 1268 | blk_status_t ret = BLK_STS_OK; |
ab3cee37 | 1269 | bool no_budget_avail = false; |
0512a75b | 1270 | LIST_HEAD(zone_list); |
320ae51f | 1271 | |
81380ca1 OS |
1272 | if (list_empty(list)) |
1273 | return false; | |
1274 | ||
de148297 ML |
1275 | WARN_ON(!list_is_singular(list) && got_budget); |
1276 | ||
320ae51f JA |
1277 | /* |
1278 | * Now process all the entries, sending them to the driver. | |
1279 | */ | |
93efe981 | 1280 | errors = queued = 0; |
81380ca1 | 1281 | do { |
74c45052 | 1282 | struct blk_mq_queue_data bd; |
320ae51f | 1283 | |
f04c3df3 | 1284 | rq = list_first_entry(list, struct request, queuelist); |
0bca799b | 1285 | |
ea4f995e | 1286 | hctx = rq->mq_hctx; |
5fe56de7 JG |
1287 | if (!got_budget && !blk_mq_get_dispatch_budget(hctx)) { |
1288 | blk_mq_put_driver_tag(rq); | |
ab3cee37 | 1289 | no_budget_avail = true; |
0bca799b | 1290 | break; |
5fe56de7 | 1291 | } |
0bca799b | 1292 | |
8ab6bb9e | 1293 | if (!blk_mq_get_driver_tag(rq)) { |
3c782d67 | 1294 | /* |
da55f2cc | 1295 | * The initial allocation attempt failed, so we need to |
eb619fdb JA |
1296 | * rerun the hardware queue when a tag is freed. The |
1297 | * waitqueue takes care of that. If the queue is run | |
1298 | * before we add this entry back on the dispatch list, | |
1299 | * we'll re-run it below. | |
3c782d67 | 1300 | */ |
2278d69f | 1301 | if (!blk_mq_mark_tag_wait(hctx, rq)) { |
0bca799b | 1302 | blk_mq_put_dispatch_budget(hctx); |
f906a6a0 JA |
1303 | /* |
1304 | * For non-shared tags, the RESTART check | |
1305 | * will suffice. | |
1306 | */ | |
1307 | if (hctx->flags & BLK_MQ_F_TAG_SHARED) | |
1308 | no_tag = true; | |
de148297 ML |
1309 | break; |
1310 | } | |
1311 | } | |
1312 | ||
320ae51f | 1313 | list_del_init(&rq->queuelist); |
320ae51f | 1314 | |
74c45052 | 1315 | bd.rq = rq; |
113285b4 JA |
1316 | |
1317 | /* | |
1318 | * Flag last if we have no more requests, or if we have more | |
1319 | * but can't assign a driver tag to it. | |
1320 | */ | |
1321 | if (list_empty(list)) | |
1322 | bd.last = true; | |
1323 | else { | |
113285b4 | 1324 | nxt = list_first_entry(list, struct request, queuelist); |
8ab6bb9e | 1325 | bd.last = !blk_mq_get_driver_tag(nxt); |
113285b4 | 1326 | } |
74c45052 JA |
1327 | |
1328 | ret = q->mq_ops->queue_rq(hctx, &bd); | |
86ff7c2a | 1329 | if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) { |
c92a4103 | 1330 | blk_mq_handle_dev_resource(rq, list); |
320ae51f | 1331 | break; |
0512a75b KB |
1332 | } else if (ret == BLK_STS_ZONE_RESOURCE) { |
1333 | /* | |
1334 | * Move the request to zone_list and keep going through | |
1335 | * the dispatch list to find more requests the drive can | |
1336 | * accept. | |
1337 | */ | |
1338 | blk_mq_handle_zone_resource(rq, &zone_list); | |
1339 | if (list_empty(list)) | |
1340 | break; | |
1341 | continue; | |
fc17b653 CH |
1342 | } |
1343 | ||
1344 | if (unlikely(ret != BLK_STS_OK)) { | |
93efe981 | 1345 | errors++; |
2a842aca | 1346 | blk_mq_end_request(rq, BLK_STS_IOERR); |
fc17b653 | 1347 | continue; |
320ae51f JA |
1348 | } |
1349 | ||
fc17b653 | 1350 | queued++; |
81380ca1 | 1351 | } while (!list_empty(list)); |
320ae51f | 1352 | |
0512a75b KB |
1353 | if (!list_empty(&zone_list)) |
1354 | list_splice_tail_init(&zone_list, list); | |
1355 | ||
703fd1c0 | 1356 | hctx->dispatched[queued_to_index(queued)]++; |
320ae51f JA |
1357 | |
1358 | /* | |
1359 | * Any items that need requeuing? Stuff them into hctx->dispatch, | |
1360 | * that is where we will continue on next queue run. | |
1361 | */ | |
f04c3df3 | 1362 | if (!list_empty(list)) { |
86ff7c2a ML |
1363 | bool needs_restart; |
1364 | ||
d666ba98 JA |
1365 | /* |
1366 | * If we didn't flush the entire list, we could have told | |
1367 | * the driver there was more coming, but that turned out to | |
1368 | * be a lie. | |
1369 | */ | |
536167d4 | 1370 | if (q->mq_ops->commit_rqs && queued) |
d666ba98 JA |
1371 | q->mq_ops->commit_rqs(hctx); |
1372 | ||
320ae51f | 1373 | spin_lock(&hctx->lock); |
01e99aec | 1374 | list_splice_tail_init(list, &hctx->dispatch); |
320ae51f | 1375 | spin_unlock(&hctx->lock); |
f04c3df3 | 1376 | |
9ba52e58 | 1377 | /* |
710c785f BVA |
1378 | * If SCHED_RESTART was set by the caller of this function and |
1379 | * it is no longer set that means that it was cleared by another | |
1380 | * thread and hence that a queue rerun is needed. | |
9ba52e58 | 1381 | * |
eb619fdb JA |
1382 | * If 'no_tag' is set, that means that we failed getting |
1383 | * a driver tag with an I/O scheduler attached. If our dispatch | |
1384 | * waitqueue is no longer active, ensure that we run the queue | |
1385 | * AFTER adding our entries back to the list. | |
bd166ef1 | 1386 | * |
710c785f BVA |
1387 | * If no I/O scheduler has been configured it is possible that |
1388 | * the hardware queue got stopped and restarted before requests | |
1389 | * were pushed back onto the dispatch list. Rerun the queue to | |
1390 | * avoid starvation. Notes: | |
1391 | * - blk_mq_run_hw_queue() checks whether or not a queue has | |
1392 | * been stopped before rerunning a queue. | |
1393 | * - Some but not all block drivers stop a queue before | |
fc17b653 | 1394 | * returning BLK_STS_RESOURCE. Two exceptions are scsi-mq |
710c785f | 1395 | * and dm-rq. |
86ff7c2a ML |
1396 | * |
1397 | * If driver returns BLK_STS_RESOURCE and SCHED_RESTART | |
1398 | * bit is set, run queue after a delay to avoid IO stalls | |
ab3cee37 DA |
1399 | * that could otherwise occur if the queue is idle. We'll do |
1400 | * similar if we couldn't get budget and SCHED_RESTART is set. | |
bd166ef1 | 1401 | */ |
86ff7c2a ML |
1402 | needs_restart = blk_mq_sched_needs_restart(hctx); |
1403 | if (!needs_restart || | |
eb619fdb | 1404 | (no_tag && list_empty_careful(&hctx->dispatch_wait.entry))) |
bd166ef1 | 1405 | blk_mq_run_hw_queue(hctx, true); |
ab3cee37 DA |
1406 | else if (needs_restart && (ret == BLK_STS_RESOURCE || |
1407 | no_budget_avail)) | |
86ff7c2a | 1408 | blk_mq_delay_run_hw_queue(hctx, BLK_MQ_RESOURCE_DELAY); |
1f57f8d4 | 1409 | |
6e768717 | 1410 | blk_mq_update_dispatch_busy(hctx, true); |
1f57f8d4 | 1411 | return false; |
6e768717 ML |
1412 | } else |
1413 | blk_mq_update_dispatch_busy(hctx, false); | |
f04c3df3 | 1414 | |
1f57f8d4 JA |
1415 | /* |
1416 | * If the host/device is unable to accept more work, inform the | |
1417 | * caller of that. | |
1418 | */ | |
1419 | if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) | |
1420 | return false; | |
1421 | ||
93efe981 | 1422 | return (queued + errors) != 0; |
f04c3df3 JA |
1423 | } |
1424 | ||
105663f7 AA |
1425 | /** |
1426 | * __blk_mq_run_hw_queue - Run a hardware queue. | |
1427 | * @hctx: Pointer to the hardware queue to run. | |
1428 | * | |
1429 | * Send pending requests to the hardware. | |
1430 | */ | |
6a83e74d BVA |
1431 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) |
1432 | { | |
1433 | int srcu_idx; | |
1434 | ||
b7a71e66 JA |
1435 | /* |
1436 | * We should be running this queue from one of the CPUs that | |
1437 | * are mapped to it. | |
7df938fb ML |
1438 | * |
1439 | * There are at least two related races now between setting | |
1440 | * hctx->next_cpu from blk_mq_hctx_next_cpu() and running | |
1441 | * __blk_mq_run_hw_queue(): | |
1442 | * | |
1443 | * - hctx->next_cpu is found offline in blk_mq_hctx_next_cpu(), | |
1444 | * but later it becomes online, then this warning is harmless | |
1445 | * at all | |
1446 | * | |
1447 | * - hctx->next_cpu is found online in blk_mq_hctx_next_cpu(), | |
1448 | * but later it becomes offline, then the warning can't be | |
1449 | * triggered, and we depend on blk-mq timeout handler to | |
1450 | * handle dispatched requests to this hctx | |
b7a71e66 | 1451 | */ |
7df938fb ML |
1452 | if (!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) && |
1453 | cpu_online(hctx->next_cpu)) { | |
1454 | printk(KERN_WARNING "run queue from wrong CPU %d, hctx %s\n", | |
1455 | raw_smp_processor_id(), | |
1456 | cpumask_empty(hctx->cpumask) ? "inactive": "active"); | |
1457 | dump_stack(); | |
1458 | } | |
6a83e74d | 1459 | |
b7a71e66 JA |
1460 | /* |
1461 | * We can't run the queue inline with ints disabled. Ensure that | |
1462 | * we catch bad users of this early. | |
1463 | */ | |
1464 | WARN_ON_ONCE(in_interrupt()); | |
1465 | ||
04ced159 | 1466 | might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING); |
bf4907c0 | 1467 | |
04ced159 JA |
1468 | hctx_lock(hctx, &srcu_idx); |
1469 | blk_mq_sched_dispatch_requests(hctx); | |
1470 | hctx_unlock(hctx, srcu_idx); | |
6a83e74d BVA |
1471 | } |
1472 | ||
f82ddf19 ML |
1473 | static inline int blk_mq_first_mapped_cpu(struct blk_mq_hw_ctx *hctx) |
1474 | { | |
1475 | int cpu = cpumask_first_and(hctx->cpumask, cpu_online_mask); | |
1476 | ||
1477 | if (cpu >= nr_cpu_ids) | |
1478 | cpu = cpumask_first(hctx->cpumask); | |
1479 | return cpu; | |
1480 | } | |
1481 | ||
506e931f JA |
1482 | /* |
1483 | * It'd be great if the workqueue API had a way to pass | |
1484 | * in a mask and had some smarts for more clever placement. | |
1485 | * For now we just round-robin here, switching for every | |
1486 | * BLK_MQ_CPU_WORK_BATCH queued items. | |
1487 | */ | |
1488 | static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) | |
1489 | { | |
7bed4595 | 1490 | bool tried = false; |
476f8c98 | 1491 | int next_cpu = hctx->next_cpu; |
7bed4595 | 1492 | |
b657d7e6 CH |
1493 | if (hctx->queue->nr_hw_queues == 1) |
1494 | return WORK_CPU_UNBOUND; | |
506e931f JA |
1495 | |
1496 | if (--hctx->next_cpu_batch <= 0) { | |
7bed4595 | 1497 | select_cpu: |
476f8c98 | 1498 | next_cpu = cpumask_next_and(next_cpu, hctx->cpumask, |
20e4d813 | 1499 | cpu_online_mask); |
506e931f | 1500 | if (next_cpu >= nr_cpu_ids) |
f82ddf19 | 1501 | next_cpu = blk_mq_first_mapped_cpu(hctx); |
506e931f JA |
1502 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; |
1503 | } | |
1504 | ||
7bed4595 ML |
1505 | /* |
1506 | * Do unbound schedule if we can't find a online CPU for this hctx, | |
1507 | * and it should only happen in the path of handling CPU DEAD. | |
1508 | */ | |
476f8c98 | 1509 | if (!cpu_online(next_cpu)) { |
7bed4595 ML |
1510 | if (!tried) { |
1511 | tried = true; | |
1512 | goto select_cpu; | |
1513 | } | |
1514 | ||
1515 | /* | |
1516 | * Make sure to re-select CPU next time once after CPUs | |
1517 | * in hctx->cpumask become online again. | |
1518 | */ | |
476f8c98 | 1519 | hctx->next_cpu = next_cpu; |
7bed4595 ML |
1520 | hctx->next_cpu_batch = 1; |
1521 | return WORK_CPU_UNBOUND; | |
1522 | } | |
476f8c98 ML |
1523 | |
1524 | hctx->next_cpu = next_cpu; | |
1525 | return next_cpu; | |
506e931f JA |
1526 | } |
1527 | ||
105663f7 AA |
1528 | /** |
1529 | * __blk_mq_delay_run_hw_queue - Run (or schedule to run) a hardware queue. | |
1530 | * @hctx: Pointer to the hardware queue to run. | |
1531 | * @async: If we want to run the queue asynchronously. | |
1532 | * @msecs: Microseconds of delay to wait before running the queue. | |
1533 | * | |
1534 | * If !@async, try to run the queue now. Else, run the queue asynchronously and | |
1535 | * with a delay of @msecs. | |
1536 | */ | |
7587a5ae BVA |
1537 | static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async, |
1538 | unsigned long msecs) | |
320ae51f | 1539 | { |
5435c023 | 1540 | if (unlikely(blk_mq_hctx_stopped(hctx))) |
320ae51f JA |
1541 | return; |
1542 | ||
1b792f2f | 1543 | if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) { |
2a90d4aa PB |
1544 | int cpu = get_cpu(); |
1545 | if (cpumask_test_cpu(cpu, hctx->cpumask)) { | |
398205b8 | 1546 | __blk_mq_run_hw_queue(hctx); |
2a90d4aa | 1547 | put_cpu(); |
398205b8 PB |
1548 | return; |
1549 | } | |
e4043dcf | 1550 | |
2a90d4aa | 1551 | put_cpu(); |
e4043dcf | 1552 | } |
398205b8 | 1553 | |
ae943d20 BVA |
1554 | kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work, |
1555 | msecs_to_jiffies(msecs)); | |
7587a5ae BVA |
1556 | } |
1557 | ||
105663f7 AA |
1558 | /** |
1559 | * blk_mq_delay_run_hw_queue - Run a hardware queue asynchronously. | |
1560 | * @hctx: Pointer to the hardware queue to run. | |
1561 | * @msecs: Microseconds of delay to wait before running the queue. | |
1562 | * | |
1563 | * Run a hardware queue asynchronously with a delay of @msecs. | |
1564 | */ | |
7587a5ae BVA |
1565 | void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) |
1566 | { | |
1567 | __blk_mq_delay_run_hw_queue(hctx, true, msecs); | |
1568 | } | |
1569 | EXPORT_SYMBOL(blk_mq_delay_run_hw_queue); | |
1570 | ||
105663f7 AA |
1571 | /** |
1572 | * blk_mq_run_hw_queue - Start to run a hardware queue. | |
1573 | * @hctx: Pointer to the hardware queue to run. | |
1574 | * @async: If we want to run the queue asynchronously. | |
1575 | * | |
1576 | * Check if the request queue is not in a quiesced state and if there are | |
1577 | * pending requests to be sent. If this is true, run the queue to send requests | |
1578 | * to hardware. | |
1579 | */ | |
626fb735 | 1580 | void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
7587a5ae | 1581 | { |
24f5a90f ML |
1582 | int srcu_idx; |
1583 | bool need_run; | |
1584 | ||
1585 | /* | |
1586 | * When queue is quiesced, we may be switching io scheduler, or | |
1587 | * updating nr_hw_queues, or other things, and we can't run queue | |
1588 | * any more, even __blk_mq_hctx_has_pending() can't be called safely. | |
1589 | * | |
1590 | * And queue will be rerun in blk_mq_unquiesce_queue() if it is | |
1591 | * quiesced. | |
1592 | */ | |
04ced159 JA |
1593 | hctx_lock(hctx, &srcu_idx); |
1594 | need_run = !blk_queue_quiesced(hctx->queue) && | |
1595 | blk_mq_hctx_has_pending(hctx); | |
1596 | hctx_unlock(hctx, srcu_idx); | |
24f5a90f | 1597 | |
626fb735 | 1598 | if (need_run) |
79f720a7 | 1599 | __blk_mq_delay_run_hw_queue(hctx, async, 0); |
320ae51f | 1600 | } |
5b727272 | 1601 | EXPORT_SYMBOL(blk_mq_run_hw_queue); |
320ae51f | 1602 | |
105663f7 AA |
1603 | /** |
1604 | * blk_mq_run_hw_queue - Run all hardware queues in a request queue. | |
1605 | * @q: Pointer to the request queue to run. | |
1606 | * @async: If we want to run the queue asynchronously. | |
1607 | */ | |
b94ec296 | 1608 | void blk_mq_run_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
1609 | { |
1610 | struct blk_mq_hw_ctx *hctx; | |
1611 | int i; | |
1612 | ||
1613 | queue_for_each_hw_ctx(q, hctx, i) { | |
79f720a7 | 1614 | if (blk_mq_hctx_stopped(hctx)) |
320ae51f JA |
1615 | continue; |
1616 | ||
b94ec296 | 1617 | blk_mq_run_hw_queue(hctx, async); |
320ae51f JA |
1618 | } |
1619 | } | |
b94ec296 | 1620 | EXPORT_SYMBOL(blk_mq_run_hw_queues); |
320ae51f | 1621 | |
b9151e7b DA |
1622 | /** |
1623 | * blk_mq_delay_run_hw_queues - Run all hardware queues asynchronously. | |
1624 | * @q: Pointer to the request queue to run. | |
1625 | * @msecs: Microseconds of delay to wait before running the queues. | |
1626 | */ | |
1627 | void blk_mq_delay_run_hw_queues(struct request_queue *q, unsigned long msecs) | |
1628 | { | |
1629 | struct blk_mq_hw_ctx *hctx; | |
1630 | int i; | |
1631 | ||
1632 | queue_for_each_hw_ctx(q, hctx, i) { | |
1633 | if (blk_mq_hctx_stopped(hctx)) | |
1634 | continue; | |
1635 | ||
1636 | blk_mq_delay_run_hw_queue(hctx, msecs); | |
1637 | } | |
1638 | } | |
1639 | EXPORT_SYMBOL(blk_mq_delay_run_hw_queues); | |
1640 | ||
fd001443 BVA |
1641 | /** |
1642 | * blk_mq_queue_stopped() - check whether one or more hctxs have been stopped | |
1643 | * @q: request queue. | |
1644 | * | |
1645 | * The caller is responsible for serializing this function against | |
1646 | * blk_mq_{start,stop}_hw_queue(). | |
1647 | */ | |
1648 | bool blk_mq_queue_stopped(struct request_queue *q) | |
1649 | { | |
1650 | struct blk_mq_hw_ctx *hctx; | |
1651 | int i; | |
1652 | ||
1653 | queue_for_each_hw_ctx(q, hctx, i) | |
1654 | if (blk_mq_hctx_stopped(hctx)) | |
1655 | return true; | |
1656 | ||
1657 | return false; | |
1658 | } | |
1659 | EXPORT_SYMBOL(blk_mq_queue_stopped); | |
1660 | ||
39a70c76 ML |
1661 | /* |
1662 | * This function is often used for pausing .queue_rq() by driver when | |
1663 | * there isn't enough resource or some conditions aren't satisfied, and | |
4d606219 | 1664 | * BLK_STS_RESOURCE is usually returned. |
39a70c76 ML |
1665 | * |
1666 | * We do not guarantee that dispatch can be drained or blocked | |
1667 | * after blk_mq_stop_hw_queue() returns. Please use | |
1668 | * blk_mq_quiesce_queue() for that requirement. | |
1669 | */ | |
2719aa21 JA |
1670 | void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx) |
1671 | { | |
641a9ed6 | 1672 | cancel_delayed_work(&hctx->run_work); |
280d45f6 | 1673 | |
641a9ed6 | 1674 | set_bit(BLK_MQ_S_STOPPED, &hctx->state); |
2719aa21 | 1675 | } |
641a9ed6 | 1676 | EXPORT_SYMBOL(blk_mq_stop_hw_queue); |
2719aa21 | 1677 | |
39a70c76 ML |
1678 | /* |
1679 | * This function is often used for pausing .queue_rq() by driver when | |
1680 | * there isn't enough resource or some conditions aren't satisfied, and | |
4d606219 | 1681 | * BLK_STS_RESOURCE is usually returned. |
39a70c76 ML |
1682 | * |
1683 | * We do not guarantee that dispatch can be drained or blocked | |
1684 | * after blk_mq_stop_hw_queues() returns. Please use | |
1685 | * blk_mq_quiesce_queue() for that requirement. | |
1686 | */ | |
2719aa21 JA |
1687 | void blk_mq_stop_hw_queues(struct request_queue *q) |
1688 | { | |
641a9ed6 ML |
1689 | struct blk_mq_hw_ctx *hctx; |
1690 | int i; | |
1691 | ||
1692 | queue_for_each_hw_ctx(q, hctx, i) | |
1693 | blk_mq_stop_hw_queue(hctx); | |
280d45f6 CH |
1694 | } |
1695 | EXPORT_SYMBOL(blk_mq_stop_hw_queues); | |
1696 | ||
320ae51f JA |
1697 | void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx) |
1698 | { | |
1699 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
e4043dcf | 1700 | |
0ffbce80 | 1701 | blk_mq_run_hw_queue(hctx, false); |
320ae51f JA |
1702 | } |
1703 | EXPORT_SYMBOL(blk_mq_start_hw_queue); | |
1704 | ||
2f268556 CH |
1705 | void blk_mq_start_hw_queues(struct request_queue *q) |
1706 | { | |
1707 | struct blk_mq_hw_ctx *hctx; | |
1708 | int i; | |
1709 | ||
1710 | queue_for_each_hw_ctx(q, hctx, i) | |
1711 | blk_mq_start_hw_queue(hctx); | |
1712 | } | |
1713 | EXPORT_SYMBOL(blk_mq_start_hw_queues); | |
1714 | ||
ae911c5e JA |
1715 | void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
1716 | { | |
1717 | if (!blk_mq_hctx_stopped(hctx)) | |
1718 | return; | |
1719 | ||
1720 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
1721 | blk_mq_run_hw_queue(hctx, async); | |
1722 | } | |
1723 | EXPORT_SYMBOL_GPL(blk_mq_start_stopped_hw_queue); | |
1724 | ||
1b4a3258 | 1725 | void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
1726 | { |
1727 | struct blk_mq_hw_ctx *hctx; | |
1728 | int i; | |
1729 | ||
ae911c5e JA |
1730 | queue_for_each_hw_ctx(q, hctx, i) |
1731 | blk_mq_start_stopped_hw_queue(hctx, async); | |
320ae51f JA |
1732 | } |
1733 | EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); | |
1734 | ||
70f4db63 | 1735 | static void blk_mq_run_work_fn(struct work_struct *work) |
320ae51f JA |
1736 | { |
1737 | struct blk_mq_hw_ctx *hctx; | |
1738 | ||
9f993737 | 1739 | hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work); |
320ae51f | 1740 | |
21c6e939 | 1741 | /* |
15fe8a90 | 1742 | * If we are stopped, don't run the queue. |
21c6e939 | 1743 | */ |
15fe8a90 | 1744 | if (test_bit(BLK_MQ_S_STOPPED, &hctx->state)) |
0196d6b4 | 1745 | return; |
7587a5ae BVA |
1746 | |
1747 | __blk_mq_run_hw_queue(hctx); | |
1748 | } | |
1749 | ||
cfd0c552 | 1750 | static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx, |
cfd0c552 ML |
1751 | struct request *rq, |
1752 | bool at_head) | |
320ae51f | 1753 | { |
e57690fe | 1754 | struct blk_mq_ctx *ctx = rq->mq_ctx; |
c16d6b5a | 1755 | enum hctx_type type = hctx->type; |
e57690fe | 1756 | |
7b607814 BVA |
1757 | lockdep_assert_held(&ctx->lock); |
1758 | ||
01b983c9 JA |
1759 | trace_block_rq_insert(hctx->queue, rq); |
1760 | ||
72a0a36e | 1761 | if (at_head) |
c16d6b5a | 1762 | list_add(&rq->queuelist, &ctx->rq_lists[type]); |
72a0a36e | 1763 | else |
c16d6b5a | 1764 | list_add_tail(&rq->queuelist, &ctx->rq_lists[type]); |
cfd0c552 | 1765 | } |
4bb659b1 | 1766 | |
2c3ad667 JA |
1767 | void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, |
1768 | bool at_head) | |
cfd0c552 ML |
1769 | { |
1770 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
1771 | ||
7b607814 BVA |
1772 | lockdep_assert_held(&ctx->lock); |
1773 | ||
e57690fe | 1774 | __blk_mq_insert_req_list(hctx, rq, at_head); |
320ae51f | 1775 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f JA |
1776 | } |
1777 | ||
105663f7 AA |
1778 | /** |
1779 | * blk_mq_request_bypass_insert - Insert a request at dispatch list. | |
1780 | * @rq: Pointer to request to be inserted. | |
1781 | * @run_queue: If we should run the hardware queue after inserting the request. | |
1782 | * | |
157f377b JA |
1783 | * Should only be used carefully, when the caller knows we want to |
1784 | * bypass a potential IO scheduler on the target device. | |
1785 | */ | |
01e99aec ML |
1786 | void blk_mq_request_bypass_insert(struct request *rq, bool at_head, |
1787 | bool run_queue) | |
157f377b | 1788 | { |
ea4f995e | 1789 | struct blk_mq_hw_ctx *hctx = rq->mq_hctx; |
157f377b JA |
1790 | |
1791 | spin_lock(&hctx->lock); | |
01e99aec ML |
1792 | if (at_head) |
1793 | list_add(&rq->queuelist, &hctx->dispatch); | |
1794 | else | |
1795 | list_add_tail(&rq->queuelist, &hctx->dispatch); | |
157f377b JA |
1796 | spin_unlock(&hctx->lock); |
1797 | ||
b0850297 ML |
1798 | if (run_queue) |
1799 | blk_mq_run_hw_queue(hctx, false); | |
157f377b JA |
1800 | } |
1801 | ||
bd166ef1 JA |
1802 | void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, |
1803 | struct list_head *list) | |
320ae51f JA |
1804 | |
1805 | { | |
3f0cedc7 | 1806 | struct request *rq; |
c16d6b5a | 1807 | enum hctx_type type = hctx->type; |
3f0cedc7 | 1808 | |
320ae51f JA |
1809 | /* |
1810 | * preemption doesn't flush plug list, so it's possible ctx->cpu is | |
1811 | * offline now | |
1812 | */ | |
3f0cedc7 | 1813 | list_for_each_entry(rq, list, queuelist) { |
e57690fe | 1814 | BUG_ON(rq->mq_ctx != ctx); |
3f0cedc7 | 1815 | trace_block_rq_insert(hctx->queue, rq); |
320ae51f | 1816 | } |
3f0cedc7 ML |
1817 | |
1818 | spin_lock(&ctx->lock); | |
c16d6b5a | 1819 | list_splice_tail_init(list, &ctx->rq_lists[type]); |
cfd0c552 | 1820 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f | 1821 | spin_unlock(&ctx->lock); |
320ae51f JA |
1822 | } |
1823 | ||
3110fc79 | 1824 | static int plug_rq_cmp(void *priv, struct list_head *a, struct list_head *b) |
320ae51f JA |
1825 | { |
1826 | struct request *rqa = container_of(a, struct request, queuelist); | |
1827 | struct request *rqb = container_of(b, struct request, queuelist); | |
1828 | ||
7d30a621 PB |
1829 | if (rqa->mq_ctx != rqb->mq_ctx) |
1830 | return rqa->mq_ctx > rqb->mq_ctx; | |
1831 | if (rqa->mq_hctx != rqb->mq_hctx) | |
1832 | return rqa->mq_hctx > rqb->mq_hctx; | |
3110fc79 JA |
1833 | |
1834 | return blk_rq_pos(rqa) > blk_rq_pos(rqb); | |
320ae51f JA |
1835 | } |
1836 | ||
1837 | void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) | |
1838 | { | |
320ae51f | 1839 | LIST_HEAD(list); |
320ae51f | 1840 | |
95ed0c5b PB |
1841 | if (list_empty(&plug->mq_list)) |
1842 | return; | |
320ae51f JA |
1843 | list_splice_init(&plug->mq_list, &list); |
1844 | ||
ce5b009c JA |
1845 | if (plug->rq_count > 2 && plug->multiple_queues) |
1846 | list_sort(NULL, &list, plug_rq_cmp); | |
320ae51f | 1847 | |
bcc816df DZ |
1848 | plug->rq_count = 0; |
1849 | ||
95ed0c5b PB |
1850 | do { |
1851 | struct list_head rq_list; | |
1852 | struct request *rq, *head_rq = list_entry_rq(list.next); | |
1853 | struct list_head *pos = &head_rq->queuelist; /* skip first */ | |
1854 | struct blk_mq_hw_ctx *this_hctx = head_rq->mq_hctx; | |
1855 | struct blk_mq_ctx *this_ctx = head_rq->mq_ctx; | |
1856 | unsigned int depth = 1; | |
1857 | ||
1858 | list_for_each_continue(pos, &list) { | |
1859 | rq = list_entry_rq(pos); | |
1860 | BUG_ON(!rq->q); | |
1861 | if (rq->mq_hctx != this_hctx || rq->mq_ctx != this_ctx) | |
1862 | break; | |
1863 | depth++; | |
320ae51f JA |
1864 | } |
1865 | ||
95ed0c5b PB |
1866 | list_cut_before(&rq_list, &list, pos); |
1867 | trace_block_unplug(head_rq->q, depth, !from_schedule); | |
67cae4c9 | 1868 | blk_mq_sched_insert_requests(this_hctx, this_ctx, &rq_list, |
bd166ef1 | 1869 | from_schedule); |
95ed0c5b | 1870 | } while(!list_empty(&list)); |
320ae51f JA |
1871 | } |
1872 | ||
14ccb66b CH |
1873 | static void blk_mq_bio_to_request(struct request *rq, struct bio *bio, |
1874 | unsigned int nr_segs) | |
320ae51f | 1875 | { |
f924cdde CH |
1876 | if (bio->bi_opf & REQ_RAHEAD) |
1877 | rq->cmd_flags |= REQ_FAILFAST_MASK; | |
1878 | ||
1879 | rq->__sector = bio->bi_iter.bi_sector; | |
1880 | rq->write_hint = bio->bi_write_hint; | |
14ccb66b | 1881 | blk_rq_bio_prep(rq, bio, nr_segs); |
a892c8d5 | 1882 | blk_crypto_rq_bio_prep(rq, bio, GFP_NOIO); |
4b570521 | 1883 | |
b5af37ab | 1884 | blk_account_io_start(rq); |
320ae51f JA |
1885 | } |
1886 | ||
0f95549c MS |
1887 | static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx, |
1888 | struct request *rq, | |
be94f058 | 1889 | blk_qc_t *cookie, bool last) |
f984df1f | 1890 | { |
f984df1f | 1891 | struct request_queue *q = rq->q; |
f984df1f SL |
1892 | struct blk_mq_queue_data bd = { |
1893 | .rq = rq, | |
be94f058 | 1894 | .last = last, |
f984df1f | 1895 | }; |
bd166ef1 | 1896 | blk_qc_t new_cookie; |
f06345ad | 1897 | blk_status_t ret; |
0f95549c MS |
1898 | |
1899 | new_cookie = request_to_qc_t(hctx, rq); | |
1900 | ||
1901 | /* | |
1902 | * For OK queue, we are done. For error, caller may kill it. | |
1903 | * Any other error (busy), just add it to our list as we | |
1904 | * previously would have done. | |
1905 | */ | |
1906 | ret = q->mq_ops->queue_rq(hctx, &bd); | |
1907 | switch (ret) { | |
1908 | case BLK_STS_OK: | |
6ce3dd6e | 1909 | blk_mq_update_dispatch_busy(hctx, false); |
0f95549c MS |
1910 | *cookie = new_cookie; |
1911 | break; | |
1912 | case BLK_STS_RESOURCE: | |
86ff7c2a | 1913 | case BLK_STS_DEV_RESOURCE: |
6ce3dd6e | 1914 | blk_mq_update_dispatch_busy(hctx, true); |
0f95549c MS |
1915 | __blk_mq_requeue_request(rq); |
1916 | break; | |
1917 | default: | |
6ce3dd6e | 1918 | blk_mq_update_dispatch_busy(hctx, false); |
0f95549c MS |
1919 | *cookie = BLK_QC_T_NONE; |
1920 | break; | |
1921 | } | |
1922 | ||
1923 | return ret; | |
1924 | } | |
1925 | ||
fd9c40f6 | 1926 | static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, |
0f95549c | 1927 | struct request *rq, |
396eaf21 | 1928 | blk_qc_t *cookie, |
fd9c40f6 | 1929 | bool bypass_insert, bool last) |
0f95549c MS |
1930 | { |
1931 | struct request_queue *q = rq->q; | |
d964f04a ML |
1932 | bool run_queue = true; |
1933 | ||
23d4ee19 | 1934 | /* |
fd9c40f6 | 1935 | * RCU or SRCU read lock is needed before checking quiesced flag. |
23d4ee19 | 1936 | * |
fd9c40f6 BVA |
1937 | * When queue is stopped or quiesced, ignore 'bypass_insert' from |
1938 | * blk_mq_request_issue_directly(), and return BLK_STS_OK to caller, | |
1939 | * and avoid driver to try to dispatch again. | |
23d4ee19 | 1940 | */ |
fd9c40f6 | 1941 | if (blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(q)) { |
d964f04a | 1942 | run_queue = false; |
fd9c40f6 BVA |
1943 | bypass_insert = false; |
1944 | goto insert; | |
d964f04a | 1945 | } |
f984df1f | 1946 | |
fd9c40f6 BVA |
1947 | if (q->elevator && !bypass_insert) |
1948 | goto insert; | |
2253efc8 | 1949 | |
0bca799b | 1950 | if (!blk_mq_get_dispatch_budget(hctx)) |
fd9c40f6 | 1951 | goto insert; |
bd166ef1 | 1952 | |
8ab6bb9e | 1953 | if (!blk_mq_get_driver_tag(rq)) { |
0bca799b | 1954 | blk_mq_put_dispatch_budget(hctx); |
fd9c40f6 | 1955 | goto insert; |
88022d72 | 1956 | } |
de148297 | 1957 | |
fd9c40f6 BVA |
1958 | return __blk_mq_issue_directly(hctx, rq, cookie, last); |
1959 | insert: | |
1960 | if (bypass_insert) | |
1961 | return BLK_STS_RESOURCE; | |
1962 | ||
01e99aec | 1963 | blk_mq_request_bypass_insert(rq, false, run_queue); |
fd9c40f6 BVA |
1964 | return BLK_STS_OK; |
1965 | } | |
1966 | ||
105663f7 AA |
1967 | /** |
1968 | * blk_mq_try_issue_directly - Try to send a request directly to device driver. | |
1969 | * @hctx: Pointer of the associated hardware queue. | |
1970 | * @rq: Pointer to request to be sent. | |
1971 | * @cookie: Request queue cookie. | |
1972 | * | |
1973 | * If the device has enough resources to accept a new request now, send the | |
1974 | * request directly to device driver. Else, insert at hctx->dispatch queue, so | |
1975 | * we can try send it another time in the future. Requests inserted at this | |
1976 | * queue have higher priority. | |
1977 | */ | |
fd9c40f6 BVA |
1978 | static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, |
1979 | struct request *rq, blk_qc_t *cookie) | |
1980 | { | |
1981 | blk_status_t ret; | |
1982 | int srcu_idx; | |
1983 | ||
1984 | might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING); | |
1985 | ||
1986 | hctx_lock(hctx, &srcu_idx); | |
1987 | ||
1988 | ret = __blk_mq_try_issue_directly(hctx, rq, cookie, false, true); | |
1989 | if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) | |
01e99aec | 1990 | blk_mq_request_bypass_insert(rq, false, true); |
fd9c40f6 BVA |
1991 | else if (ret != BLK_STS_OK) |
1992 | blk_mq_end_request(rq, ret); | |
1993 | ||
1994 | hctx_unlock(hctx, srcu_idx); | |
1995 | } | |
1996 | ||
1997 | blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last) | |
1998 | { | |
1999 | blk_status_t ret; | |
2000 | int srcu_idx; | |
2001 | blk_qc_t unused_cookie; | |
2002 | struct blk_mq_hw_ctx *hctx = rq->mq_hctx; | |
2003 | ||
2004 | hctx_lock(hctx, &srcu_idx); | |
2005 | ret = __blk_mq_try_issue_directly(hctx, rq, &unused_cookie, true, last); | |
04ced159 | 2006 | hctx_unlock(hctx, srcu_idx); |
7f556a44 JW |
2007 | |
2008 | return ret; | |
5eb6126e CH |
2009 | } |
2010 | ||
6ce3dd6e ML |
2011 | void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, |
2012 | struct list_head *list) | |
2013 | { | |
536167d4 KB |
2014 | int queued = 0; |
2015 | ||
6ce3dd6e | 2016 | while (!list_empty(list)) { |
fd9c40f6 | 2017 | blk_status_t ret; |
6ce3dd6e ML |
2018 | struct request *rq = list_first_entry(list, struct request, |
2019 | queuelist); | |
2020 | ||
2021 | list_del_init(&rq->queuelist); | |
fd9c40f6 BVA |
2022 | ret = blk_mq_request_issue_directly(rq, list_empty(list)); |
2023 | if (ret != BLK_STS_OK) { | |
2024 | if (ret == BLK_STS_RESOURCE || | |
2025 | ret == BLK_STS_DEV_RESOURCE) { | |
01e99aec | 2026 | blk_mq_request_bypass_insert(rq, false, |
c616cbee | 2027 | list_empty(list)); |
fd9c40f6 BVA |
2028 | break; |
2029 | } | |
2030 | blk_mq_end_request(rq, ret); | |
536167d4 KB |
2031 | } else |
2032 | queued++; | |
6ce3dd6e | 2033 | } |
d666ba98 JA |
2034 | |
2035 | /* | |
2036 | * If we didn't flush the entire list, we could have told | |
2037 | * the driver there was more coming, but that turned out to | |
2038 | * be a lie. | |
2039 | */ | |
536167d4 | 2040 | if (!list_empty(list) && hctx->queue->mq_ops->commit_rqs && queued) |
d666ba98 | 2041 | hctx->queue->mq_ops->commit_rqs(hctx); |
6ce3dd6e ML |
2042 | } |
2043 | ||
ce5b009c JA |
2044 | static void blk_add_rq_to_plug(struct blk_plug *plug, struct request *rq) |
2045 | { | |
2046 | list_add_tail(&rq->queuelist, &plug->mq_list); | |
2047 | plug->rq_count++; | |
2048 | if (!plug->multiple_queues && !list_is_singular(&plug->mq_list)) { | |
2049 | struct request *tmp; | |
2050 | ||
2051 | tmp = list_first_entry(&plug->mq_list, struct request, | |
2052 | queuelist); | |
2053 | if (tmp->q != rq->q) | |
2054 | plug->multiple_queues = true; | |
2055 | } | |
2056 | } | |
2057 | ||
105663f7 AA |
2058 | /** |
2059 | * blk_mq_make_request - Create and send a request to block device. | |
2060 | * @q: Request queue pointer. | |
2061 | * @bio: Bio pointer. | |
2062 | * | |
2063 | * Builds up a request structure from @q and @bio and send to the device. The | |
2064 | * request may not be queued directly to hardware if: | |
2065 | * * This request can be merged with another one | |
2066 | * * We want to place request at plug queue for possible future merging | |
2067 | * * There is an IO scheduler active at this queue | |
2068 | * | |
2069 | * It will not queue the request if there is an error with the bio, or at the | |
2070 | * request creation. | |
2071 | * | |
2072 | * Returns: Request queue cookie. | |
2073 | */ | |
8cf7961d | 2074 | blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) |
07068d5b | 2075 | { |
ef295ecf | 2076 | const int is_sync = op_is_sync(bio->bi_opf); |
f73f44eb | 2077 | const int is_flush_fua = op_is_flush(bio->bi_opf); |
e6e7abff CH |
2078 | struct blk_mq_alloc_data data = { |
2079 | .q = q, | |
2080 | }; | |
07068d5b | 2081 | struct request *rq; |
f984df1f | 2082 | struct blk_plug *plug; |
5b3f341f | 2083 | struct request *same_queue_rq = NULL; |
14ccb66b | 2084 | unsigned int nr_segs; |
7b371636 | 2085 | blk_qc_t cookie; |
a892c8d5 | 2086 | blk_status_t ret; |
07068d5b JA |
2087 | |
2088 | blk_queue_bounce(q, &bio); | |
14ccb66b | 2089 | __blk_queue_split(q, &bio, &nr_segs); |
f36ea50c | 2090 | |
e23947bd | 2091 | if (!bio_integrity_prep(bio)) |
ac7c5675 | 2092 | goto queue_exit; |
07068d5b | 2093 | |
87c279e6 | 2094 | if (!is_flush_fua && !blk_queue_nomerges(q) && |
14ccb66b | 2095 | blk_attempt_plug_merge(q, bio, nr_segs, &same_queue_rq)) |
ac7c5675 | 2096 | goto queue_exit; |
f984df1f | 2097 | |
14ccb66b | 2098 | if (blk_mq_sched_bio_merge(q, bio, nr_segs)) |
ac7c5675 | 2099 | goto queue_exit; |
bd166ef1 | 2100 | |
d5337560 | 2101 | rq_qos_throttle(q, bio); |
87760e5e | 2102 | |
7809167d | 2103 | data.cmd_flags = bio->bi_opf; |
e6e7abff | 2104 | rq = __blk_mq_alloc_request(&data); |
87760e5e | 2105 | if (unlikely(!rq)) { |
c1c80384 | 2106 | rq_qos_cleanup(q, bio); |
7b6620d7 | 2107 | if (bio->bi_opf & REQ_NOWAIT) |
03a07c92 | 2108 | bio_wouldblock_error(bio); |
ac7c5675 | 2109 | goto queue_exit; |
87760e5e JA |
2110 | } |
2111 | ||
d6f1dda2 XW |
2112 | trace_block_getrq(q, bio, bio->bi_opf); |
2113 | ||
c1c80384 | 2114 | rq_qos_track(q, rq, bio); |
07068d5b | 2115 | |
fd2d3326 | 2116 | cookie = request_to_qc_t(data.hctx, rq); |
07068d5b | 2117 | |
970d168d BVA |
2118 | blk_mq_bio_to_request(rq, bio, nr_segs); |
2119 | ||
a892c8d5 ST |
2120 | ret = blk_crypto_init_request(rq); |
2121 | if (ret != BLK_STS_OK) { | |
2122 | bio->bi_status = ret; | |
2123 | bio_endio(bio); | |
2124 | blk_mq_free_request(rq); | |
2125 | return BLK_QC_T_NONE; | |
2126 | } | |
2127 | ||
b49773e7 | 2128 | plug = blk_mq_plug(q, bio); |
07068d5b | 2129 | if (unlikely(is_flush_fua)) { |
105663f7 | 2130 | /* Bypass scheduler for flush requests */ |
923218f6 ML |
2131 | blk_insert_flush(rq); |
2132 | blk_mq_run_hw_queue(data.hctx, true); | |
3154df26 ML |
2133 | } else if (plug && (q->nr_hw_queues == 1 || q->mq_ops->commit_rqs || |
2134 | !blk_queue_nonrot(q))) { | |
b2c5d16b JA |
2135 | /* |
2136 | * Use plugging if we have a ->commit_rqs() hook as well, as | |
2137 | * we know the driver uses bd->last in a smart fashion. | |
3154df26 ML |
2138 | * |
2139 | * Use normal plugging if this disk is slow HDD, as sequential | |
2140 | * IO may benefit a lot from plug merging. | |
b2c5d16b | 2141 | */ |
5f0ed774 | 2142 | unsigned int request_count = plug->rq_count; |
600271d9 SL |
2143 | struct request *last = NULL; |
2144 | ||
676d0607 | 2145 | if (!request_count) |
e6c4438b | 2146 | trace_block_plug(q); |
600271d9 SL |
2147 | else |
2148 | last = list_entry_rq(plug->mq_list.prev); | |
b094f89c | 2149 | |
600271d9 SL |
2150 | if (request_count >= BLK_MAX_REQUEST_COUNT || (last && |
2151 | blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE)) { | |
e6c4438b JM |
2152 | blk_flush_plug_list(plug, false); |
2153 | trace_block_plug(q); | |
320ae51f | 2154 | } |
b094f89c | 2155 | |
ce5b009c | 2156 | blk_add_rq_to_plug(plug, rq); |
a12de1d4 | 2157 | } else if (q->elevator) { |
105663f7 | 2158 | /* Insert the request at the IO scheduler queue */ |
a12de1d4 | 2159 | blk_mq_sched_insert_request(rq, false, true, true); |
2299722c | 2160 | } else if (plug && !blk_queue_nomerges(q)) { |
07068d5b | 2161 | /* |
6a83e74d | 2162 | * We do limited plugging. If the bio can be merged, do that. |
f984df1f SL |
2163 | * Otherwise the existing request in the plug list will be |
2164 | * issued. So the plug list will have one request at most | |
2299722c CH |
2165 | * The plug list might get flushed before this. If that happens, |
2166 | * the plug list is empty, and same_queue_rq is invalid. | |
07068d5b | 2167 | */ |
2299722c CH |
2168 | if (list_empty(&plug->mq_list)) |
2169 | same_queue_rq = NULL; | |
4711b573 | 2170 | if (same_queue_rq) { |
2299722c | 2171 | list_del_init(&same_queue_rq->queuelist); |
4711b573 JA |
2172 | plug->rq_count--; |
2173 | } | |
ce5b009c | 2174 | blk_add_rq_to_plug(plug, rq); |
ff3b74b8 | 2175 | trace_block_plug(q); |
2299722c | 2176 | |
dad7a3be | 2177 | if (same_queue_rq) { |
ea4f995e | 2178 | data.hctx = same_queue_rq->mq_hctx; |
ff3b74b8 | 2179 | trace_block_unplug(q, 1, true); |
2299722c | 2180 | blk_mq_try_issue_directly(data.hctx, same_queue_rq, |
fd9c40f6 | 2181 | &cookie); |
dad7a3be | 2182 | } |
a12de1d4 ML |
2183 | } else if ((q->nr_hw_queues > 1 && is_sync) || |
2184 | !data.hctx->dispatch_busy) { | |
105663f7 AA |
2185 | /* |
2186 | * There is no scheduler and we can try to send directly | |
2187 | * to the hardware. | |
2188 | */ | |
fd9c40f6 | 2189 | blk_mq_try_issue_directly(data.hctx, rq, &cookie); |
ab42f35d | 2190 | } else { |
105663f7 | 2191 | /* Default case. */ |
8fa9f556 | 2192 | blk_mq_sched_insert_request(rq, false, true, true); |
ab42f35d | 2193 | } |
320ae51f | 2194 | |
7b371636 | 2195 | return cookie; |
ac7c5675 CH |
2196 | queue_exit: |
2197 | blk_queue_exit(q); | |
2198 | return BLK_QC_T_NONE; | |
320ae51f | 2199 | } |
8cf7961d | 2200 | EXPORT_SYMBOL_GPL(blk_mq_make_request); /* only for request based dm */ |
320ae51f | 2201 | |
cc71a6f4 JA |
2202 | void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, |
2203 | unsigned int hctx_idx) | |
95363efd | 2204 | { |
e9b267d9 | 2205 | struct page *page; |
320ae51f | 2206 | |
24d2f903 | 2207 | if (tags->rqs && set->ops->exit_request) { |
e9b267d9 | 2208 | int i; |
320ae51f | 2209 | |
24d2f903 | 2210 | for (i = 0; i < tags->nr_tags; i++) { |
2af8cbe3 JA |
2211 | struct request *rq = tags->static_rqs[i]; |
2212 | ||
2213 | if (!rq) | |
e9b267d9 | 2214 | continue; |
d6296d39 | 2215 | set->ops->exit_request(set, rq, hctx_idx); |
2af8cbe3 | 2216 | tags->static_rqs[i] = NULL; |
e9b267d9 | 2217 | } |
320ae51f | 2218 | } |
320ae51f | 2219 | |
24d2f903 CH |
2220 | while (!list_empty(&tags->page_list)) { |
2221 | page = list_first_entry(&tags->page_list, struct page, lru); | |
6753471c | 2222 | list_del_init(&page->lru); |
f75782e4 CM |
2223 | /* |
2224 | * Remove kmemleak object previously allocated in | |
273938bf | 2225 | * blk_mq_alloc_rqs(). |
f75782e4 CM |
2226 | */ |
2227 | kmemleak_free(page_address(page)); | |
320ae51f JA |
2228 | __free_pages(page, page->private); |
2229 | } | |
cc71a6f4 | 2230 | } |
320ae51f | 2231 | |
cc71a6f4 JA |
2232 | void blk_mq_free_rq_map(struct blk_mq_tags *tags) |
2233 | { | |
24d2f903 | 2234 | kfree(tags->rqs); |
cc71a6f4 | 2235 | tags->rqs = NULL; |
2af8cbe3 JA |
2236 | kfree(tags->static_rqs); |
2237 | tags->static_rqs = NULL; | |
320ae51f | 2238 | |
24d2f903 | 2239 | blk_mq_free_tags(tags); |
320ae51f JA |
2240 | } |
2241 | ||
cc71a6f4 JA |
2242 | struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, |
2243 | unsigned int hctx_idx, | |
2244 | unsigned int nr_tags, | |
2245 | unsigned int reserved_tags) | |
320ae51f | 2246 | { |
24d2f903 | 2247 | struct blk_mq_tags *tags; |
59f082e4 | 2248 | int node; |
320ae51f | 2249 | |
7d76f856 | 2250 | node = blk_mq_hw_queue_to_node(&set->map[HCTX_TYPE_DEFAULT], hctx_idx); |
59f082e4 SL |
2251 | if (node == NUMA_NO_NODE) |
2252 | node = set->numa_node; | |
2253 | ||
2254 | tags = blk_mq_init_tags(nr_tags, reserved_tags, node, | |
24391c0d | 2255 | BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags)); |
24d2f903 CH |
2256 | if (!tags) |
2257 | return NULL; | |
320ae51f | 2258 | |
590b5b7d | 2259 | tags->rqs = kcalloc_node(nr_tags, sizeof(struct request *), |
36e1f3d1 | 2260 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, |
59f082e4 | 2261 | node); |
24d2f903 CH |
2262 | if (!tags->rqs) { |
2263 | blk_mq_free_tags(tags); | |
2264 | return NULL; | |
2265 | } | |
320ae51f | 2266 | |
590b5b7d KC |
2267 | tags->static_rqs = kcalloc_node(nr_tags, sizeof(struct request *), |
2268 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, | |
2269 | node); | |
2af8cbe3 JA |
2270 | if (!tags->static_rqs) { |
2271 | kfree(tags->rqs); | |
2272 | blk_mq_free_tags(tags); | |
2273 | return NULL; | |
2274 | } | |
2275 | ||
cc71a6f4 JA |
2276 | return tags; |
2277 | } | |
2278 | ||
2279 | static size_t order_to_size(unsigned int order) | |
2280 | { | |
2281 | return (size_t)PAGE_SIZE << order; | |
2282 | } | |
2283 | ||
1d9bd516 TH |
2284 | static int blk_mq_init_request(struct blk_mq_tag_set *set, struct request *rq, |
2285 | unsigned int hctx_idx, int node) | |
2286 | { | |
2287 | int ret; | |
2288 | ||
2289 | if (set->ops->init_request) { | |
2290 | ret = set->ops->init_request(set, rq, hctx_idx, node); | |
2291 | if (ret) | |
2292 | return ret; | |
2293 | } | |
2294 | ||
12f5b931 | 2295 | WRITE_ONCE(rq->state, MQ_RQ_IDLE); |
1d9bd516 TH |
2296 | return 0; |
2297 | } | |
2298 | ||
cc71a6f4 JA |
2299 | int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, |
2300 | unsigned int hctx_idx, unsigned int depth) | |
2301 | { | |
2302 | unsigned int i, j, entries_per_page, max_order = 4; | |
2303 | size_t rq_size, left; | |
59f082e4 SL |
2304 | int node; |
2305 | ||
7d76f856 | 2306 | node = blk_mq_hw_queue_to_node(&set->map[HCTX_TYPE_DEFAULT], hctx_idx); |
59f082e4 SL |
2307 | if (node == NUMA_NO_NODE) |
2308 | node = set->numa_node; | |
cc71a6f4 JA |
2309 | |
2310 | INIT_LIST_HEAD(&tags->page_list); | |
2311 | ||
320ae51f JA |
2312 | /* |
2313 | * rq_size is the size of the request plus driver payload, rounded | |
2314 | * to the cacheline size | |
2315 | */ | |
24d2f903 | 2316 | rq_size = round_up(sizeof(struct request) + set->cmd_size, |
320ae51f | 2317 | cache_line_size()); |
cc71a6f4 | 2318 | left = rq_size * depth; |
320ae51f | 2319 | |
cc71a6f4 | 2320 | for (i = 0; i < depth; ) { |
320ae51f JA |
2321 | int this_order = max_order; |
2322 | struct page *page; | |
2323 | int to_do; | |
2324 | void *p; | |
2325 | ||
b3a834b1 | 2326 | while (this_order && left < order_to_size(this_order - 1)) |
320ae51f JA |
2327 | this_order--; |
2328 | ||
2329 | do { | |
59f082e4 | 2330 | page = alloc_pages_node(node, |
36e1f3d1 | 2331 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO, |
a5164405 | 2332 | this_order); |
320ae51f JA |
2333 | if (page) |
2334 | break; | |
2335 | if (!this_order--) | |
2336 | break; | |
2337 | if (order_to_size(this_order) < rq_size) | |
2338 | break; | |
2339 | } while (1); | |
2340 | ||
2341 | if (!page) | |
24d2f903 | 2342 | goto fail; |
320ae51f JA |
2343 | |
2344 | page->private = this_order; | |
24d2f903 | 2345 | list_add_tail(&page->lru, &tags->page_list); |
320ae51f JA |
2346 | |
2347 | p = page_address(page); | |
f75782e4 CM |
2348 | /* |
2349 | * Allow kmemleak to scan these pages as they contain pointers | |
2350 | * to additional allocations like via ops->init_request(). | |
2351 | */ | |
36e1f3d1 | 2352 | kmemleak_alloc(p, order_to_size(this_order), 1, GFP_NOIO); |
320ae51f | 2353 | entries_per_page = order_to_size(this_order) / rq_size; |
cc71a6f4 | 2354 | to_do = min(entries_per_page, depth - i); |
320ae51f JA |
2355 | left -= to_do * rq_size; |
2356 | for (j = 0; j < to_do; j++) { | |
2af8cbe3 JA |
2357 | struct request *rq = p; |
2358 | ||
2359 | tags->static_rqs[i] = rq; | |
1d9bd516 TH |
2360 | if (blk_mq_init_request(set, rq, hctx_idx, node)) { |
2361 | tags->static_rqs[i] = NULL; | |
2362 | goto fail; | |
e9b267d9 CH |
2363 | } |
2364 | ||
320ae51f JA |
2365 | p += rq_size; |
2366 | i++; | |
2367 | } | |
2368 | } | |
cc71a6f4 | 2369 | return 0; |
320ae51f | 2370 | |
24d2f903 | 2371 | fail: |
cc71a6f4 JA |
2372 | blk_mq_free_rqs(set, tags, hctx_idx); |
2373 | return -ENOMEM; | |
320ae51f JA |
2374 | } |
2375 | ||
bf0beec0 ML |
2376 | struct rq_iter_data { |
2377 | struct blk_mq_hw_ctx *hctx; | |
2378 | bool has_rq; | |
2379 | }; | |
2380 | ||
2381 | static bool blk_mq_has_request(struct request *rq, void *data, bool reserved) | |
2382 | { | |
2383 | struct rq_iter_data *iter_data = data; | |
2384 | ||
2385 | if (rq->mq_hctx != iter_data->hctx) | |
2386 | return true; | |
2387 | iter_data->has_rq = true; | |
2388 | return false; | |
2389 | } | |
2390 | ||
2391 | static bool blk_mq_hctx_has_requests(struct blk_mq_hw_ctx *hctx) | |
2392 | { | |
2393 | struct blk_mq_tags *tags = hctx->sched_tags ? | |
2394 | hctx->sched_tags : hctx->tags; | |
2395 | struct rq_iter_data data = { | |
2396 | .hctx = hctx, | |
2397 | }; | |
2398 | ||
2399 | blk_mq_all_tag_iter(tags, blk_mq_has_request, &data); | |
2400 | return data.has_rq; | |
2401 | } | |
2402 | ||
2403 | static inline bool blk_mq_last_cpu_in_hctx(unsigned int cpu, | |
2404 | struct blk_mq_hw_ctx *hctx) | |
2405 | { | |
2406 | if (cpumask_next_and(-1, hctx->cpumask, cpu_online_mask) != cpu) | |
2407 | return false; | |
2408 | if (cpumask_next_and(cpu, hctx->cpumask, cpu_online_mask) < nr_cpu_ids) | |
2409 | return false; | |
2410 | return true; | |
2411 | } | |
2412 | ||
2413 | static int blk_mq_hctx_notify_offline(unsigned int cpu, struct hlist_node *node) | |
2414 | { | |
2415 | struct blk_mq_hw_ctx *hctx = hlist_entry_safe(node, | |
2416 | struct blk_mq_hw_ctx, cpuhp_online); | |
2417 | ||
2418 | if (!cpumask_test_cpu(cpu, hctx->cpumask) || | |
2419 | !blk_mq_last_cpu_in_hctx(cpu, hctx)) | |
2420 | return 0; | |
2421 | ||
2422 | /* | |
2423 | * Prevent new request from being allocated on the current hctx. | |
2424 | * | |
2425 | * The smp_mb__after_atomic() Pairs with the implied barrier in | |
2426 | * test_and_set_bit_lock in sbitmap_get(). Ensures the inactive flag is | |
2427 | * seen once we return from the tag allocator. | |
2428 | */ | |
2429 | set_bit(BLK_MQ_S_INACTIVE, &hctx->state); | |
2430 | smp_mb__after_atomic(); | |
2431 | ||
2432 | /* | |
2433 | * Try to grab a reference to the queue and wait for any outstanding | |
2434 | * requests. If we could not grab a reference the queue has been | |
2435 | * frozen and there are no requests. | |
2436 | */ | |
2437 | if (percpu_ref_tryget(&hctx->queue->q_usage_counter)) { | |
2438 | while (blk_mq_hctx_has_requests(hctx)) | |
2439 | msleep(5); | |
2440 | percpu_ref_put(&hctx->queue->q_usage_counter); | |
2441 | } | |
2442 | ||
2443 | return 0; | |
2444 | } | |
2445 | ||
2446 | static int blk_mq_hctx_notify_online(unsigned int cpu, struct hlist_node *node) | |
2447 | { | |
2448 | struct blk_mq_hw_ctx *hctx = hlist_entry_safe(node, | |
2449 | struct blk_mq_hw_ctx, cpuhp_online); | |
2450 | ||
2451 | if (cpumask_test_cpu(cpu, hctx->cpumask)) | |
2452 | clear_bit(BLK_MQ_S_INACTIVE, &hctx->state); | |
2453 | return 0; | |
2454 | } | |
2455 | ||
e57690fe JA |
2456 | /* |
2457 | * 'cpu' is going away. splice any existing rq_list entries from this | |
2458 | * software queue to the hw queue dispatch list, and ensure that it | |
2459 | * gets run. | |
2460 | */ | |
9467f859 | 2461 | static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node) |
484b4061 | 2462 | { |
9467f859 | 2463 | struct blk_mq_hw_ctx *hctx; |
484b4061 JA |
2464 | struct blk_mq_ctx *ctx; |
2465 | LIST_HEAD(tmp); | |
c16d6b5a | 2466 | enum hctx_type type; |
484b4061 | 2467 | |
9467f859 | 2468 | hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_dead); |
bf0beec0 ML |
2469 | if (!cpumask_test_cpu(cpu, hctx->cpumask)) |
2470 | return 0; | |
2471 | ||
e57690fe | 2472 | ctx = __blk_mq_get_ctx(hctx->queue, cpu); |
c16d6b5a | 2473 | type = hctx->type; |
484b4061 JA |
2474 | |
2475 | spin_lock(&ctx->lock); | |
c16d6b5a ML |
2476 | if (!list_empty(&ctx->rq_lists[type])) { |
2477 | list_splice_init(&ctx->rq_lists[type], &tmp); | |
484b4061 JA |
2478 | blk_mq_hctx_clear_pending(hctx, ctx); |
2479 | } | |
2480 | spin_unlock(&ctx->lock); | |
2481 | ||
2482 | if (list_empty(&tmp)) | |
9467f859 | 2483 | return 0; |
484b4061 | 2484 | |
e57690fe JA |
2485 | spin_lock(&hctx->lock); |
2486 | list_splice_tail_init(&tmp, &hctx->dispatch); | |
2487 | spin_unlock(&hctx->lock); | |
484b4061 JA |
2488 | |
2489 | blk_mq_run_hw_queue(hctx, true); | |
9467f859 | 2490 | return 0; |
484b4061 JA |
2491 | } |
2492 | ||
9467f859 | 2493 | static void blk_mq_remove_cpuhp(struct blk_mq_hw_ctx *hctx) |
484b4061 | 2494 | { |
bf0beec0 ML |
2495 | if (!(hctx->flags & BLK_MQ_F_STACKING)) |
2496 | cpuhp_state_remove_instance_nocalls(CPUHP_AP_BLK_MQ_ONLINE, | |
2497 | &hctx->cpuhp_online); | |
9467f859 TG |
2498 | cpuhp_state_remove_instance_nocalls(CPUHP_BLK_MQ_DEAD, |
2499 | &hctx->cpuhp_dead); | |
484b4061 JA |
2500 | } |
2501 | ||
c3b4afca | 2502 | /* hctx->ctxs will be freed in queue's release handler */ |
08e98fc6 ML |
2503 | static void blk_mq_exit_hctx(struct request_queue *q, |
2504 | struct blk_mq_tag_set *set, | |
2505 | struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) | |
2506 | { | |
8ab0b7dc ML |
2507 | if (blk_mq_hw_queue_mapped(hctx)) |
2508 | blk_mq_tag_idle(hctx); | |
08e98fc6 | 2509 | |
f70ced09 | 2510 | if (set->ops->exit_request) |
d6296d39 | 2511 | set->ops->exit_request(set, hctx->fq->flush_rq, hctx_idx); |
f70ced09 | 2512 | |
08e98fc6 ML |
2513 | if (set->ops->exit_hctx) |
2514 | set->ops->exit_hctx(hctx, hctx_idx); | |
2515 | ||
9467f859 | 2516 | blk_mq_remove_cpuhp(hctx); |
2f8f1336 ML |
2517 | |
2518 | spin_lock(&q->unused_hctx_lock); | |
2519 | list_add(&hctx->hctx_list, &q->unused_hctx_list); | |
2520 | spin_unlock(&q->unused_hctx_lock); | |
08e98fc6 ML |
2521 | } |
2522 | ||
624dbe47 ML |
2523 | static void blk_mq_exit_hw_queues(struct request_queue *q, |
2524 | struct blk_mq_tag_set *set, int nr_queue) | |
2525 | { | |
2526 | struct blk_mq_hw_ctx *hctx; | |
2527 | unsigned int i; | |
2528 | ||
2529 | queue_for_each_hw_ctx(q, hctx, i) { | |
2530 | if (i == nr_queue) | |
2531 | break; | |
477e19de | 2532 | blk_mq_debugfs_unregister_hctx(hctx); |
08e98fc6 | 2533 | blk_mq_exit_hctx(q, set, hctx, i); |
624dbe47 | 2534 | } |
624dbe47 ML |
2535 | } |
2536 | ||
7c6c5b7c ML |
2537 | static int blk_mq_hw_ctx_size(struct blk_mq_tag_set *tag_set) |
2538 | { | |
2539 | int hw_ctx_size = sizeof(struct blk_mq_hw_ctx); | |
2540 | ||
2541 | BUILD_BUG_ON(ALIGN(offsetof(struct blk_mq_hw_ctx, srcu), | |
2542 | __alignof__(struct blk_mq_hw_ctx)) != | |
2543 | sizeof(struct blk_mq_hw_ctx)); | |
2544 | ||
2545 | if (tag_set->flags & BLK_MQ_F_BLOCKING) | |
2546 | hw_ctx_size += sizeof(struct srcu_struct); | |
2547 | ||
2548 | return hw_ctx_size; | |
2549 | } | |
2550 | ||
08e98fc6 ML |
2551 | static int blk_mq_init_hctx(struct request_queue *q, |
2552 | struct blk_mq_tag_set *set, | |
2553 | struct blk_mq_hw_ctx *hctx, unsigned hctx_idx) | |
320ae51f | 2554 | { |
7c6c5b7c ML |
2555 | hctx->queue_num = hctx_idx; |
2556 | ||
bf0beec0 ML |
2557 | if (!(hctx->flags & BLK_MQ_F_STACKING)) |
2558 | cpuhp_state_add_instance_nocalls(CPUHP_AP_BLK_MQ_ONLINE, | |
2559 | &hctx->cpuhp_online); | |
7c6c5b7c ML |
2560 | cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, &hctx->cpuhp_dead); |
2561 | ||
2562 | hctx->tags = set->tags[hctx_idx]; | |
2563 | ||
2564 | if (set->ops->init_hctx && | |
2565 | set->ops->init_hctx(hctx, set->driver_data, hctx_idx)) | |
2566 | goto unregister_cpu_notifier; | |
08e98fc6 | 2567 | |
7c6c5b7c ML |
2568 | if (blk_mq_init_request(set, hctx->fq->flush_rq, hctx_idx, |
2569 | hctx->numa_node)) | |
2570 | goto exit_hctx; | |
2571 | return 0; | |
2572 | ||
2573 | exit_hctx: | |
2574 | if (set->ops->exit_hctx) | |
2575 | set->ops->exit_hctx(hctx, hctx_idx); | |
2576 | unregister_cpu_notifier: | |
2577 | blk_mq_remove_cpuhp(hctx); | |
2578 | return -1; | |
2579 | } | |
2580 | ||
2581 | static struct blk_mq_hw_ctx * | |
2582 | blk_mq_alloc_hctx(struct request_queue *q, struct blk_mq_tag_set *set, | |
2583 | int node) | |
2584 | { | |
2585 | struct blk_mq_hw_ctx *hctx; | |
2586 | gfp_t gfp = GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY; | |
2587 | ||
2588 | hctx = kzalloc_node(blk_mq_hw_ctx_size(set), gfp, node); | |
2589 | if (!hctx) | |
2590 | goto fail_alloc_hctx; | |
2591 | ||
2592 | if (!zalloc_cpumask_var_node(&hctx->cpumask, gfp, node)) | |
2593 | goto free_hctx; | |
2594 | ||
2595 | atomic_set(&hctx->nr_active, 0); | |
08e98fc6 | 2596 | if (node == NUMA_NO_NODE) |
7c6c5b7c ML |
2597 | node = set->numa_node; |
2598 | hctx->numa_node = node; | |
08e98fc6 | 2599 | |
9f993737 | 2600 | INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn); |
08e98fc6 ML |
2601 | spin_lock_init(&hctx->lock); |
2602 | INIT_LIST_HEAD(&hctx->dispatch); | |
2603 | hctx->queue = q; | |
2404e607 | 2604 | hctx->flags = set->flags & ~BLK_MQ_F_TAG_SHARED; |
08e98fc6 | 2605 | |
2f8f1336 ML |
2606 | INIT_LIST_HEAD(&hctx->hctx_list); |
2607 | ||
320ae51f | 2608 | /* |
08e98fc6 ML |
2609 | * Allocate space for all possible cpus to avoid allocation at |
2610 | * runtime | |
320ae51f | 2611 | */ |
d904bfa7 | 2612 | hctx->ctxs = kmalloc_array_node(nr_cpu_ids, sizeof(void *), |
7c6c5b7c | 2613 | gfp, node); |
08e98fc6 | 2614 | if (!hctx->ctxs) |
7c6c5b7c | 2615 | goto free_cpumask; |
320ae51f | 2616 | |
5b202853 | 2617 | if (sbitmap_init_node(&hctx->ctx_map, nr_cpu_ids, ilog2(8), |
7c6c5b7c | 2618 | gfp, node)) |
08e98fc6 | 2619 | goto free_ctxs; |
08e98fc6 | 2620 | hctx->nr_ctx = 0; |
320ae51f | 2621 | |
5815839b | 2622 | spin_lock_init(&hctx->dispatch_wait_lock); |
eb619fdb JA |
2623 | init_waitqueue_func_entry(&hctx->dispatch_wait, blk_mq_dispatch_wake); |
2624 | INIT_LIST_HEAD(&hctx->dispatch_wait.entry); | |
2625 | ||
754a1572 | 2626 | hctx->fq = blk_alloc_flush_queue(hctx->numa_node, set->cmd_size, gfp); |
f70ced09 | 2627 | if (!hctx->fq) |
7c6c5b7c | 2628 | goto free_bitmap; |
320ae51f | 2629 | |
6a83e74d | 2630 | if (hctx->flags & BLK_MQ_F_BLOCKING) |
05707b64 | 2631 | init_srcu_struct(hctx->srcu); |
7c6c5b7c | 2632 | blk_mq_hctx_kobj_init(hctx); |
6a83e74d | 2633 | |
7c6c5b7c | 2634 | return hctx; |
320ae51f | 2635 | |
08e98fc6 | 2636 | free_bitmap: |
88459642 | 2637 | sbitmap_free(&hctx->ctx_map); |
08e98fc6 ML |
2638 | free_ctxs: |
2639 | kfree(hctx->ctxs); | |
7c6c5b7c ML |
2640 | free_cpumask: |
2641 | free_cpumask_var(hctx->cpumask); | |
2642 | free_hctx: | |
2643 | kfree(hctx); | |
2644 | fail_alloc_hctx: | |
2645 | return NULL; | |
08e98fc6 | 2646 | } |
320ae51f | 2647 | |
320ae51f JA |
2648 | static void blk_mq_init_cpu_queues(struct request_queue *q, |
2649 | unsigned int nr_hw_queues) | |
2650 | { | |
b3c661b1 JA |
2651 | struct blk_mq_tag_set *set = q->tag_set; |
2652 | unsigned int i, j; | |
320ae51f JA |
2653 | |
2654 | for_each_possible_cpu(i) { | |
2655 | struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i); | |
2656 | struct blk_mq_hw_ctx *hctx; | |
c16d6b5a | 2657 | int k; |
320ae51f | 2658 | |
320ae51f JA |
2659 | __ctx->cpu = i; |
2660 | spin_lock_init(&__ctx->lock); | |
c16d6b5a ML |
2661 | for (k = HCTX_TYPE_DEFAULT; k < HCTX_MAX_TYPES; k++) |
2662 | INIT_LIST_HEAD(&__ctx->rq_lists[k]); | |
2663 | ||
320ae51f JA |
2664 | __ctx->queue = q; |
2665 | ||
320ae51f JA |
2666 | /* |
2667 | * Set local node, IFF we have more than one hw queue. If | |
2668 | * not, we remain on the home node of the device | |
2669 | */ | |
b3c661b1 JA |
2670 | for (j = 0; j < set->nr_maps; j++) { |
2671 | hctx = blk_mq_map_queue_type(q, j, i); | |
2672 | if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE) | |
2673 | hctx->numa_node = local_memory_node(cpu_to_node(i)); | |
2674 | } | |
320ae51f JA |
2675 | } |
2676 | } | |
2677 | ||
03b63b02 WZ |
2678 | static bool __blk_mq_alloc_map_and_request(struct blk_mq_tag_set *set, |
2679 | int hctx_idx) | |
cc71a6f4 JA |
2680 | { |
2681 | int ret = 0; | |
2682 | ||
2683 | set->tags[hctx_idx] = blk_mq_alloc_rq_map(set, hctx_idx, | |
2684 | set->queue_depth, set->reserved_tags); | |
2685 | if (!set->tags[hctx_idx]) | |
2686 | return false; | |
2687 | ||
2688 | ret = blk_mq_alloc_rqs(set, set->tags[hctx_idx], hctx_idx, | |
2689 | set->queue_depth); | |
2690 | if (!ret) | |
2691 | return true; | |
2692 | ||
2693 | blk_mq_free_rq_map(set->tags[hctx_idx]); | |
2694 | set->tags[hctx_idx] = NULL; | |
2695 | return false; | |
2696 | } | |
2697 | ||
2698 | static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set, | |
2699 | unsigned int hctx_idx) | |
2700 | { | |
4e6db0f2 | 2701 | if (set->tags && set->tags[hctx_idx]) { |
bd166ef1 JA |
2702 | blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx); |
2703 | blk_mq_free_rq_map(set->tags[hctx_idx]); | |
2704 | set->tags[hctx_idx] = NULL; | |
2705 | } | |
cc71a6f4 JA |
2706 | } |
2707 | ||
4b855ad3 | 2708 | static void blk_mq_map_swqueue(struct request_queue *q) |
320ae51f | 2709 | { |
b3c661b1 | 2710 | unsigned int i, j, hctx_idx; |
320ae51f JA |
2711 | struct blk_mq_hw_ctx *hctx; |
2712 | struct blk_mq_ctx *ctx; | |
2a34c087 | 2713 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f JA |
2714 | |
2715 | queue_for_each_hw_ctx(q, hctx, i) { | |
e4043dcf | 2716 | cpumask_clear(hctx->cpumask); |
320ae51f | 2717 | hctx->nr_ctx = 0; |
d416c92c | 2718 | hctx->dispatch_from = NULL; |
320ae51f JA |
2719 | } |
2720 | ||
2721 | /* | |
4b855ad3 | 2722 | * Map software to hardware queues. |
4412efec ML |
2723 | * |
2724 | * If the cpu isn't present, the cpu is mapped to first hctx. | |
320ae51f | 2725 | */ |
20e4d813 | 2726 | for_each_possible_cpu(i) { |
4412efec | 2727 | |
897bb0c7 | 2728 | ctx = per_cpu_ptr(q->queue_ctx, i); |
b3c661b1 | 2729 | for (j = 0; j < set->nr_maps; j++) { |
bb94aea1 JW |
2730 | if (!set->map[j].nr_queues) { |
2731 | ctx->hctxs[j] = blk_mq_map_queue_type(q, | |
2732 | HCTX_TYPE_DEFAULT, i); | |
e5edd5f2 | 2733 | continue; |
bb94aea1 | 2734 | } |
fd689871 ML |
2735 | hctx_idx = set->map[j].mq_map[i]; |
2736 | /* unmapped hw queue can be remapped after CPU topo changed */ | |
2737 | if (!set->tags[hctx_idx] && | |
03b63b02 | 2738 | !__blk_mq_alloc_map_and_request(set, hctx_idx)) { |
fd689871 ML |
2739 | /* |
2740 | * If tags initialization fail for some hctx, | |
2741 | * that hctx won't be brought online. In this | |
2742 | * case, remap the current ctx to hctx[0] which | |
2743 | * is guaranteed to always have tags allocated | |
2744 | */ | |
2745 | set->map[j].mq_map[i] = 0; | |
2746 | } | |
e5edd5f2 | 2747 | |
b3c661b1 | 2748 | hctx = blk_mq_map_queue_type(q, j, i); |
8ccdf4a3 | 2749 | ctx->hctxs[j] = hctx; |
b3c661b1 JA |
2750 | /* |
2751 | * If the CPU is already set in the mask, then we've | |
2752 | * mapped this one already. This can happen if | |
2753 | * devices share queues across queue maps. | |
2754 | */ | |
2755 | if (cpumask_test_cpu(i, hctx->cpumask)) | |
2756 | continue; | |
2757 | ||
2758 | cpumask_set_cpu(i, hctx->cpumask); | |
2759 | hctx->type = j; | |
2760 | ctx->index_hw[hctx->type] = hctx->nr_ctx; | |
2761 | hctx->ctxs[hctx->nr_ctx++] = ctx; | |
2762 | ||
2763 | /* | |
2764 | * If the nr_ctx type overflows, we have exceeded the | |
2765 | * amount of sw queues we can support. | |
2766 | */ | |
2767 | BUG_ON(!hctx->nr_ctx); | |
2768 | } | |
bb94aea1 JW |
2769 | |
2770 | for (; j < HCTX_MAX_TYPES; j++) | |
2771 | ctx->hctxs[j] = blk_mq_map_queue_type(q, | |
2772 | HCTX_TYPE_DEFAULT, i); | |
320ae51f | 2773 | } |
506e931f JA |
2774 | |
2775 | queue_for_each_hw_ctx(q, hctx, i) { | |
4412efec ML |
2776 | /* |
2777 | * If no software queues are mapped to this hardware queue, | |
2778 | * disable it and free the request entries. | |
2779 | */ | |
2780 | if (!hctx->nr_ctx) { | |
2781 | /* Never unmap queue 0. We need it as a | |
2782 | * fallback in case of a new remap fails | |
2783 | * allocation | |
2784 | */ | |
2785 | if (i && set->tags[i]) | |
2786 | blk_mq_free_map_and_requests(set, i); | |
2787 | ||
2788 | hctx->tags = NULL; | |
2789 | continue; | |
2790 | } | |
484b4061 | 2791 | |
2a34c087 ML |
2792 | hctx->tags = set->tags[i]; |
2793 | WARN_ON(!hctx->tags); | |
2794 | ||
889fa31f CY |
2795 | /* |
2796 | * Set the map size to the number of mapped software queues. | |
2797 | * This is more accurate and more efficient than looping | |
2798 | * over all possibly mapped software queues. | |
2799 | */ | |
88459642 | 2800 | sbitmap_resize(&hctx->ctx_map, hctx->nr_ctx); |
889fa31f | 2801 | |
484b4061 JA |
2802 | /* |
2803 | * Initialize batch roundrobin counts | |
2804 | */ | |
f82ddf19 | 2805 | hctx->next_cpu = blk_mq_first_mapped_cpu(hctx); |
506e931f JA |
2806 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; |
2807 | } | |
320ae51f JA |
2808 | } |
2809 | ||
8e8320c9 JA |
2810 | /* |
2811 | * Caller needs to ensure that we're either frozen/quiesced, or that | |
2812 | * the queue isn't live yet. | |
2813 | */ | |
2404e607 | 2814 | static void queue_set_hctx_shared(struct request_queue *q, bool shared) |
0d2602ca JA |
2815 | { |
2816 | struct blk_mq_hw_ctx *hctx; | |
0d2602ca JA |
2817 | int i; |
2818 | ||
2404e607 | 2819 | queue_for_each_hw_ctx(q, hctx, i) { |
97889f9a | 2820 | if (shared) |
2404e607 | 2821 | hctx->flags |= BLK_MQ_F_TAG_SHARED; |
97889f9a | 2822 | else |
2404e607 JM |
2823 | hctx->flags &= ~BLK_MQ_F_TAG_SHARED; |
2824 | } | |
2825 | } | |
2826 | ||
8e8320c9 JA |
2827 | static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set, |
2828 | bool shared) | |
2404e607 JM |
2829 | { |
2830 | struct request_queue *q; | |
0d2602ca | 2831 | |
705cda97 BVA |
2832 | lockdep_assert_held(&set->tag_list_lock); |
2833 | ||
0d2602ca JA |
2834 | list_for_each_entry(q, &set->tag_list, tag_set_list) { |
2835 | blk_mq_freeze_queue(q); | |
2404e607 | 2836 | queue_set_hctx_shared(q, shared); |
0d2602ca JA |
2837 | blk_mq_unfreeze_queue(q); |
2838 | } | |
2839 | } | |
2840 | ||
2841 | static void blk_mq_del_queue_tag_set(struct request_queue *q) | |
2842 | { | |
2843 | struct blk_mq_tag_set *set = q->tag_set; | |
2844 | ||
0d2602ca | 2845 | mutex_lock(&set->tag_list_lock); |
705cda97 | 2846 | list_del_rcu(&q->tag_set_list); |
2404e607 JM |
2847 | if (list_is_singular(&set->tag_list)) { |
2848 | /* just transitioned to unshared */ | |
2849 | set->flags &= ~BLK_MQ_F_TAG_SHARED; | |
2850 | /* update existing queue */ | |
2851 | blk_mq_update_tag_set_depth(set, false); | |
2852 | } | |
0d2602ca | 2853 | mutex_unlock(&set->tag_list_lock); |
a347c7ad | 2854 | INIT_LIST_HEAD(&q->tag_set_list); |
0d2602ca JA |
2855 | } |
2856 | ||
2857 | static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, | |
2858 | struct request_queue *q) | |
2859 | { | |
0d2602ca | 2860 | mutex_lock(&set->tag_list_lock); |
2404e607 | 2861 | |
ff821d27 JA |
2862 | /* |
2863 | * Check to see if we're transitioning to shared (from 1 to 2 queues). | |
2864 | */ | |
2865 | if (!list_empty(&set->tag_list) && | |
2866 | !(set->flags & BLK_MQ_F_TAG_SHARED)) { | |
2404e607 JM |
2867 | set->flags |= BLK_MQ_F_TAG_SHARED; |
2868 | /* update existing queue */ | |
2869 | blk_mq_update_tag_set_depth(set, true); | |
2870 | } | |
2871 | if (set->flags & BLK_MQ_F_TAG_SHARED) | |
2872 | queue_set_hctx_shared(q, true); | |
705cda97 | 2873 | list_add_tail_rcu(&q->tag_set_list, &set->tag_list); |
2404e607 | 2874 | |
0d2602ca JA |
2875 | mutex_unlock(&set->tag_list_lock); |
2876 | } | |
2877 | ||
1db4909e ML |
2878 | /* All allocations will be freed in release handler of q->mq_kobj */ |
2879 | static int blk_mq_alloc_ctxs(struct request_queue *q) | |
2880 | { | |
2881 | struct blk_mq_ctxs *ctxs; | |
2882 | int cpu; | |
2883 | ||
2884 | ctxs = kzalloc(sizeof(*ctxs), GFP_KERNEL); | |
2885 | if (!ctxs) | |
2886 | return -ENOMEM; | |
2887 | ||
2888 | ctxs->queue_ctx = alloc_percpu(struct blk_mq_ctx); | |
2889 | if (!ctxs->queue_ctx) | |
2890 | goto fail; | |
2891 | ||
2892 | for_each_possible_cpu(cpu) { | |
2893 | struct blk_mq_ctx *ctx = per_cpu_ptr(ctxs->queue_ctx, cpu); | |
2894 | ctx->ctxs = ctxs; | |
2895 | } | |
2896 | ||
2897 | q->mq_kobj = &ctxs->kobj; | |
2898 | q->queue_ctx = ctxs->queue_ctx; | |
2899 | ||
2900 | return 0; | |
2901 | fail: | |
2902 | kfree(ctxs); | |
2903 | return -ENOMEM; | |
2904 | } | |
2905 | ||
e09aae7e ML |
2906 | /* |
2907 | * It is the actual release handler for mq, but we do it from | |
2908 | * request queue's release handler for avoiding use-after-free | |
2909 | * and headache because q->mq_kobj shouldn't have been introduced, | |
2910 | * but we can't group ctx/kctx kobj without it. | |
2911 | */ | |
2912 | void blk_mq_release(struct request_queue *q) | |
2913 | { | |
2f8f1336 ML |
2914 | struct blk_mq_hw_ctx *hctx, *next; |
2915 | int i; | |
e09aae7e | 2916 | |
2f8f1336 ML |
2917 | queue_for_each_hw_ctx(q, hctx, i) |
2918 | WARN_ON_ONCE(hctx && list_empty(&hctx->hctx_list)); | |
2919 | ||
2920 | /* all hctx are in .unused_hctx_list now */ | |
2921 | list_for_each_entry_safe(hctx, next, &q->unused_hctx_list, hctx_list) { | |
2922 | list_del_init(&hctx->hctx_list); | |
6c8b232e | 2923 | kobject_put(&hctx->kobj); |
c3b4afca | 2924 | } |
e09aae7e ML |
2925 | |
2926 | kfree(q->queue_hw_ctx); | |
2927 | ||
7ea5fe31 ML |
2928 | /* |
2929 | * release .mq_kobj and sw queue's kobject now because | |
2930 | * both share lifetime with request queue. | |
2931 | */ | |
2932 | blk_mq_sysfs_deinit(q); | |
e09aae7e ML |
2933 | } |
2934 | ||
2f227bb9 CH |
2935 | struct request_queue *blk_mq_init_queue_data(struct blk_mq_tag_set *set, |
2936 | void *queuedata) | |
b62c21b7 MS |
2937 | { |
2938 | struct request_queue *uninit_q, *q; | |
2939 | ||
3d745ea5 | 2940 | uninit_q = __blk_alloc_queue(set->numa_node); |
b62c21b7 MS |
2941 | if (!uninit_q) |
2942 | return ERR_PTR(-ENOMEM); | |
2f227bb9 | 2943 | uninit_q->queuedata = queuedata; |
b62c21b7 | 2944 | |
737eb78e DLM |
2945 | /* |
2946 | * Initialize the queue without an elevator. device_add_disk() will do | |
2947 | * the initialization. | |
2948 | */ | |
2949 | q = blk_mq_init_allocated_queue(set, uninit_q, false); | |
b62c21b7 MS |
2950 | if (IS_ERR(q)) |
2951 | blk_cleanup_queue(uninit_q); | |
2952 | ||
2953 | return q; | |
2954 | } | |
2f227bb9 CH |
2955 | EXPORT_SYMBOL_GPL(blk_mq_init_queue_data); |
2956 | ||
2957 | struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) | |
2958 | { | |
2959 | return blk_mq_init_queue_data(set, NULL); | |
2960 | } | |
b62c21b7 MS |
2961 | EXPORT_SYMBOL(blk_mq_init_queue); |
2962 | ||
9316a9ed JA |
2963 | /* |
2964 | * Helper for setting up a queue with mq ops, given queue depth, and | |
2965 | * the passed in mq ops flags. | |
2966 | */ | |
2967 | struct request_queue *blk_mq_init_sq_queue(struct blk_mq_tag_set *set, | |
2968 | const struct blk_mq_ops *ops, | |
2969 | unsigned int queue_depth, | |
2970 | unsigned int set_flags) | |
2971 | { | |
2972 | struct request_queue *q; | |
2973 | int ret; | |
2974 | ||
2975 | memset(set, 0, sizeof(*set)); | |
2976 | set->ops = ops; | |
2977 | set->nr_hw_queues = 1; | |
b3c661b1 | 2978 | set->nr_maps = 1; |
9316a9ed JA |
2979 | set->queue_depth = queue_depth; |
2980 | set->numa_node = NUMA_NO_NODE; | |
2981 | set->flags = set_flags; | |
2982 | ||
2983 | ret = blk_mq_alloc_tag_set(set); | |
2984 | if (ret) | |
2985 | return ERR_PTR(ret); | |
2986 | ||
2987 | q = blk_mq_init_queue(set); | |
2988 | if (IS_ERR(q)) { | |
2989 | blk_mq_free_tag_set(set); | |
2990 | return q; | |
2991 | } | |
2992 | ||
2993 | return q; | |
2994 | } | |
2995 | EXPORT_SYMBOL(blk_mq_init_sq_queue); | |
2996 | ||
34d11ffa JW |
2997 | static struct blk_mq_hw_ctx *blk_mq_alloc_and_init_hctx( |
2998 | struct blk_mq_tag_set *set, struct request_queue *q, | |
2999 | int hctx_idx, int node) | |
3000 | { | |
2f8f1336 | 3001 | struct blk_mq_hw_ctx *hctx = NULL, *tmp; |
34d11ffa | 3002 | |
2f8f1336 ML |
3003 | /* reuse dead hctx first */ |
3004 | spin_lock(&q->unused_hctx_lock); | |
3005 | list_for_each_entry(tmp, &q->unused_hctx_list, hctx_list) { | |
3006 | if (tmp->numa_node == node) { | |
3007 | hctx = tmp; | |
3008 | break; | |
3009 | } | |
3010 | } | |
3011 | if (hctx) | |
3012 | list_del_init(&hctx->hctx_list); | |
3013 | spin_unlock(&q->unused_hctx_lock); | |
3014 | ||
3015 | if (!hctx) | |
3016 | hctx = blk_mq_alloc_hctx(q, set, node); | |
34d11ffa | 3017 | if (!hctx) |
7c6c5b7c | 3018 | goto fail; |
34d11ffa | 3019 | |
7c6c5b7c ML |
3020 | if (blk_mq_init_hctx(q, set, hctx, hctx_idx)) |
3021 | goto free_hctx; | |
34d11ffa JW |
3022 | |
3023 | return hctx; | |
7c6c5b7c ML |
3024 | |
3025 | free_hctx: | |
3026 | kobject_put(&hctx->kobj); | |
3027 | fail: | |
3028 | return NULL; | |
34d11ffa JW |
3029 | } |
3030 | ||
868f2f0b KB |
3031 | static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, |
3032 | struct request_queue *q) | |
320ae51f | 3033 | { |
e01ad46d | 3034 | int i, j, end; |
868f2f0b | 3035 | struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx; |
f14bbe77 | 3036 | |
ac0d6b92 BVA |
3037 | if (q->nr_hw_queues < set->nr_hw_queues) { |
3038 | struct blk_mq_hw_ctx **new_hctxs; | |
3039 | ||
3040 | new_hctxs = kcalloc_node(set->nr_hw_queues, | |
3041 | sizeof(*new_hctxs), GFP_KERNEL, | |
3042 | set->numa_node); | |
3043 | if (!new_hctxs) | |
3044 | return; | |
3045 | if (hctxs) | |
3046 | memcpy(new_hctxs, hctxs, q->nr_hw_queues * | |
3047 | sizeof(*hctxs)); | |
3048 | q->queue_hw_ctx = new_hctxs; | |
ac0d6b92 BVA |
3049 | kfree(hctxs); |
3050 | hctxs = new_hctxs; | |
3051 | } | |
3052 | ||
fb350e0a ML |
3053 | /* protect against switching io scheduler */ |
3054 | mutex_lock(&q->sysfs_lock); | |
24d2f903 | 3055 | for (i = 0; i < set->nr_hw_queues; i++) { |
868f2f0b | 3056 | int node; |
34d11ffa | 3057 | struct blk_mq_hw_ctx *hctx; |
868f2f0b | 3058 | |
7d76f856 | 3059 | node = blk_mq_hw_queue_to_node(&set->map[HCTX_TYPE_DEFAULT], i); |
34d11ffa JW |
3060 | /* |
3061 | * If the hw queue has been mapped to another numa node, | |
3062 | * we need to realloc the hctx. If allocation fails, fallback | |
3063 | * to use the previous one. | |
3064 | */ | |
3065 | if (hctxs[i] && (hctxs[i]->numa_node == node)) | |
3066 | continue; | |
868f2f0b | 3067 | |
34d11ffa JW |
3068 | hctx = blk_mq_alloc_and_init_hctx(set, q, i, node); |
3069 | if (hctx) { | |
2f8f1336 | 3070 | if (hctxs[i]) |
34d11ffa | 3071 | blk_mq_exit_hctx(q, set, hctxs[i], i); |
34d11ffa JW |
3072 | hctxs[i] = hctx; |
3073 | } else { | |
3074 | if (hctxs[i]) | |
3075 | pr_warn("Allocate new hctx on node %d fails,\ | |
3076 | fallback to previous one on node %d\n", | |
3077 | node, hctxs[i]->numa_node); | |
3078 | else | |
3079 | break; | |
868f2f0b | 3080 | } |
320ae51f | 3081 | } |
e01ad46d JW |
3082 | /* |
3083 | * Increasing nr_hw_queues fails. Free the newly allocated | |
3084 | * hctxs and keep the previous q->nr_hw_queues. | |
3085 | */ | |
3086 | if (i != set->nr_hw_queues) { | |
3087 | j = q->nr_hw_queues; | |
3088 | end = i; | |
3089 | } else { | |
3090 | j = i; | |
3091 | end = q->nr_hw_queues; | |
3092 | q->nr_hw_queues = set->nr_hw_queues; | |
3093 | } | |
34d11ffa | 3094 | |
e01ad46d | 3095 | for (; j < end; j++) { |
868f2f0b KB |
3096 | struct blk_mq_hw_ctx *hctx = hctxs[j]; |
3097 | ||
3098 | if (hctx) { | |
cc71a6f4 JA |
3099 | if (hctx->tags) |
3100 | blk_mq_free_map_and_requests(set, j); | |
868f2f0b | 3101 | blk_mq_exit_hctx(q, set, hctx, j); |
868f2f0b | 3102 | hctxs[j] = NULL; |
868f2f0b KB |
3103 | } |
3104 | } | |
fb350e0a | 3105 | mutex_unlock(&q->sysfs_lock); |
868f2f0b KB |
3106 | } |
3107 | ||
3108 | struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, | |
737eb78e DLM |
3109 | struct request_queue *q, |
3110 | bool elevator_init) | |
868f2f0b | 3111 | { |
66841672 ML |
3112 | /* mark the queue as mq asap */ |
3113 | q->mq_ops = set->ops; | |
3114 | ||
34dbad5d | 3115 | q->poll_cb = blk_stat_alloc_callback(blk_mq_poll_stats_fn, |
720b8ccc SB |
3116 | blk_mq_poll_stats_bkt, |
3117 | BLK_MQ_POLL_STATS_BKTS, q); | |
34dbad5d OS |
3118 | if (!q->poll_cb) |
3119 | goto err_exit; | |
3120 | ||
1db4909e | 3121 | if (blk_mq_alloc_ctxs(q)) |
41de54c6 | 3122 | goto err_poll; |
868f2f0b | 3123 | |
737f98cf ML |
3124 | /* init q->mq_kobj and sw queues' kobjects */ |
3125 | blk_mq_sysfs_init(q); | |
3126 | ||
2f8f1336 ML |
3127 | INIT_LIST_HEAD(&q->unused_hctx_list); |
3128 | spin_lock_init(&q->unused_hctx_lock); | |
3129 | ||
868f2f0b KB |
3130 | blk_mq_realloc_hw_ctxs(set, q); |
3131 | if (!q->nr_hw_queues) | |
3132 | goto err_hctxs; | |
320ae51f | 3133 | |
287922eb | 3134 | INIT_WORK(&q->timeout_work, blk_mq_timeout_work); |
e56f698b | 3135 | blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ); |
320ae51f | 3136 | |
a8908939 | 3137 | q->tag_set = set; |
320ae51f | 3138 | |
94eddfbe | 3139 | q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; |
cd19181b ML |
3140 | if (set->nr_maps > HCTX_TYPE_POLL && |
3141 | set->map[HCTX_TYPE_POLL].nr_queues) | |
6544d229 | 3142 | blk_queue_flag_set(QUEUE_FLAG_POLL, q); |
320ae51f | 3143 | |
1be036e9 CH |
3144 | q->sg_reserved_size = INT_MAX; |
3145 | ||
2849450a | 3146 | INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work); |
6fca6a61 CH |
3147 | INIT_LIST_HEAD(&q->requeue_list); |
3148 | spin_lock_init(&q->requeue_lock); | |
3149 | ||
eba71768 JA |
3150 | q->nr_requests = set->queue_depth; |
3151 | ||
64f1c21e JA |
3152 | /* |
3153 | * Default to classic polling | |
3154 | */ | |
29ece8b4 | 3155 | q->poll_nsec = BLK_MQ_POLL_CLASSIC; |
64f1c21e | 3156 | |
24d2f903 | 3157 | blk_mq_init_cpu_queues(q, set->nr_hw_queues); |
0d2602ca | 3158 | blk_mq_add_queue_tag_set(set, q); |
4b855ad3 | 3159 | blk_mq_map_swqueue(q); |
4593fdbe | 3160 | |
737eb78e DLM |
3161 | if (elevator_init) |
3162 | elevator_init_mq(q); | |
d3484991 | 3163 | |
320ae51f | 3164 | return q; |
18741986 | 3165 | |
320ae51f | 3166 | err_hctxs: |
868f2f0b | 3167 | kfree(q->queue_hw_ctx); |
73d9c8d4 | 3168 | q->nr_hw_queues = 0; |
1db4909e | 3169 | blk_mq_sysfs_deinit(q); |
41de54c6 JS |
3170 | err_poll: |
3171 | blk_stat_free_callback(q->poll_cb); | |
3172 | q->poll_cb = NULL; | |
c7de5726 ML |
3173 | err_exit: |
3174 | q->mq_ops = NULL; | |
320ae51f JA |
3175 | return ERR_PTR(-ENOMEM); |
3176 | } | |
b62c21b7 | 3177 | EXPORT_SYMBOL(blk_mq_init_allocated_queue); |
320ae51f | 3178 | |
c7e2d94b ML |
3179 | /* tags can _not_ be used after returning from blk_mq_exit_queue */ |
3180 | void blk_mq_exit_queue(struct request_queue *q) | |
320ae51f | 3181 | { |
624dbe47 | 3182 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 3183 | |
0d2602ca | 3184 | blk_mq_del_queue_tag_set(q); |
624dbe47 | 3185 | blk_mq_exit_hw_queues(q, set, set->nr_hw_queues); |
320ae51f | 3186 | } |
320ae51f | 3187 | |
a5164405 JA |
3188 | static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) |
3189 | { | |
3190 | int i; | |
3191 | ||
cc71a6f4 | 3192 | for (i = 0; i < set->nr_hw_queues; i++) |
03b63b02 | 3193 | if (!__blk_mq_alloc_map_and_request(set, i)) |
a5164405 | 3194 | goto out_unwind; |
a5164405 JA |
3195 | |
3196 | return 0; | |
3197 | ||
3198 | out_unwind: | |
3199 | while (--i >= 0) | |
2e194422 | 3200 | blk_mq_free_map_and_requests(set, i); |
a5164405 | 3201 | |
a5164405 JA |
3202 | return -ENOMEM; |
3203 | } | |
3204 | ||
3205 | /* | |
3206 | * Allocate the request maps associated with this tag_set. Note that this | |
3207 | * may reduce the depth asked for, if memory is tight. set->queue_depth | |
3208 | * will be updated to reflect the allocated depth. | |
3209 | */ | |
79fab528 | 3210 | static int blk_mq_alloc_map_and_requests(struct blk_mq_tag_set *set) |
a5164405 JA |
3211 | { |
3212 | unsigned int depth; | |
3213 | int err; | |
3214 | ||
3215 | depth = set->queue_depth; | |
3216 | do { | |
3217 | err = __blk_mq_alloc_rq_maps(set); | |
3218 | if (!err) | |
3219 | break; | |
3220 | ||
3221 | set->queue_depth >>= 1; | |
3222 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) { | |
3223 | err = -ENOMEM; | |
3224 | break; | |
3225 | } | |
3226 | } while (set->queue_depth); | |
3227 | ||
3228 | if (!set->queue_depth || err) { | |
3229 | pr_err("blk-mq: failed to allocate request map\n"); | |
3230 | return -ENOMEM; | |
3231 | } | |
3232 | ||
3233 | if (depth != set->queue_depth) | |
3234 | pr_info("blk-mq: reduced tag depth (%u -> %u)\n", | |
3235 | depth, set->queue_depth); | |
3236 | ||
3237 | return 0; | |
3238 | } | |
3239 | ||
ebe8bddb OS |
3240 | static int blk_mq_update_queue_map(struct blk_mq_tag_set *set) |
3241 | { | |
6e66b493 BVA |
3242 | /* |
3243 | * blk_mq_map_queues() and multiple .map_queues() implementations | |
3244 | * expect that set->map[HCTX_TYPE_DEFAULT].nr_queues is set to the | |
3245 | * number of hardware queues. | |
3246 | */ | |
3247 | if (set->nr_maps == 1) | |
3248 | set->map[HCTX_TYPE_DEFAULT].nr_queues = set->nr_hw_queues; | |
3249 | ||
59388702 | 3250 | if (set->ops->map_queues && !is_kdump_kernel()) { |
b3c661b1 JA |
3251 | int i; |
3252 | ||
7d4901a9 ML |
3253 | /* |
3254 | * transport .map_queues is usually done in the following | |
3255 | * way: | |
3256 | * | |
3257 | * for (queue = 0; queue < set->nr_hw_queues; queue++) { | |
3258 | * mask = get_cpu_mask(queue) | |
3259 | * for_each_cpu(cpu, mask) | |
b3c661b1 | 3260 | * set->map[x].mq_map[cpu] = queue; |
7d4901a9 ML |
3261 | * } |
3262 | * | |
3263 | * When we need to remap, the table has to be cleared for | |
3264 | * killing stale mapping since one CPU may not be mapped | |
3265 | * to any hw queue. | |
3266 | */ | |
b3c661b1 JA |
3267 | for (i = 0; i < set->nr_maps; i++) |
3268 | blk_mq_clear_mq_map(&set->map[i]); | |
7d4901a9 | 3269 | |
ebe8bddb | 3270 | return set->ops->map_queues(set); |
b3c661b1 JA |
3271 | } else { |
3272 | BUG_ON(set->nr_maps > 1); | |
7d76f856 | 3273 | return blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]); |
b3c661b1 | 3274 | } |
ebe8bddb OS |
3275 | } |
3276 | ||
f7e76dbc BVA |
3277 | static int blk_mq_realloc_tag_set_tags(struct blk_mq_tag_set *set, |
3278 | int cur_nr_hw_queues, int new_nr_hw_queues) | |
3279 | { | |
3280 | struct blk_mq_tags **new_tags; | |
3281 | ||
3282 | if (cur_nr_hw_queues >= new_nr_hw_queues) | |
3283 | return 0; | |
3284 | ||
3285 | new_tags = kcalloc_node(new_nr_hw_queues, sizeof(struct blk_mq_tags *), | |
3286 | GFP_KERNEL, set->numa_node); | |
3287 | if (!new_tags) | |
3288 | return -ENOMEM; | |
3289 | ||
3290 | if (set->tags) | |
3291 | memcpy(new_tags, set->tags, cur_nr_hw_queues * | |
3292 | sizeof(*set->tags)); | |
3293 | kfree(set->tags); | |
3294 | set->tags = new_tags; | |
3295 | set->nr_hw_queues = new_nr_hw_queues; | |
3296 | ||
3297 | return 0; | |
3298 | } | |
3299 | ||
a4391c64 JA |
3300 | /* |
3301 | * Alloc a tag set to be associated with one or more request queues. | |
3302 | * May fail with EINVAL for various error conditions. May adjust the | |
c018c84f | 3303 | * requested depth down, if it's too large. In that case, the set |
a4391c64 JA |
3304 | * value will be stored in set->queue_depth. |
3305 | */ | |
24d2f903 CH |
3306 | int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) |
3307 | { | |
b3c661b1 | 3308 | int i, ret; |
da695ba2 | 3309 | |
205fb5f5 BVA |
3310 | BUILD_BUG_ON(BLK_MQ_MAX_DEPTH > 1 << BLK_MQ_UNIQUE_TAG_BITS); |
3311 | ||
24d2f903 CH |
3312 | if (!set->nr_hw_queues) |
3313 | return -EINVAL; | |
a4391c64 | 3314 | if (!set->queue_depth) |
24d2f903 CH |
3315 | return -EINVAL; |
3316 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) | |
3317 | return -EINVAL; | |
3318 | ||
7d7e0f90 | 3319 | if (!set->ops->queue_rq) |
24d2f903 CH |
3320 | return -EINVAL; |
3321 | ||
de148297 ML |
3322 | if (!set->ops->get_budget ^ !set->ops->put_budget) |
3323 | return -EINVAL; | |
3324 | ||
a4391c64 JA |
3325 | if (set->queue_depth > BLK_MQ_MAX_DEPTH) { |
3326 | pr_info("blk-mq: reduced tag depth to %u\n", | |
3327 | BLK_MQ_MAX_DEPTH); | |
3328 | set->queue_depth = BLK_MQ_MAX_DEPTH; | |
3329 | } | |
24d2f903 | 3330 | |
b3c661b1 JA |
3331 | if (!set->nr_maps) |
3332 | set->nr_maps = 1; | |
3333 | else if (set->nr_maps > HCTX_MAX_TYPES) | |
3334 | return -EINVAL; | |
3335 | ||
6637fadf SL |
3336 | /* |
3337 | * If a crashdump is active, then we are potentially in a very | |
3338 | * memory constrained environment. Limit us to 1 queue and | |
3339 | * 64 tags to prevent using too much memory. | |
3340 | */ | |
3341 | if (is_kdump_kernel()) { | |
3342 | set->nr_hw_queues = 1; | |
59388702 | 3343 | set->nr_maps = 1; |
6637fadf SL |
3344 | set->queue_depth = min(64U, set->queue_depth); |
3345 | } | |
868f2f0b | 3346 | /* |
392546ae JA |
3347 | * There is no use for more h/w queues than cpus if we just have |
3348 | * a single map | |
868f2f0b | 3349 | */ |
392546ae | 3350 | if (set->nr_maps == 1 && set->nr_hw_queues > nr_cpu_ids) |
868f2f0b | 3351 | set->nr_hw_queues = nr_cpu_ids; |
6637fadf | 3352 | |
f7e76dbc | 3353 | if (blk_mq_realloc_tag_set_tags(set, 0, set->nr_hw_queues) < 0) |
a5164405 | 3354 | return -ENOMEM; |
24d2f903 | 3355 | |
da695ba2 | 3356 | ret = -ENOMEM; |
b3c661b1 JA |
3357 | for (i = 0; i < set->nr_maps; i++) { |
3358 | set->map[i].mq_map = kcalloc_node(nr_cpu_ids, | |
07b35eb5 | 3359 | sizeof(set->map[i].mq_map[0]), |
b3c661b1 JA |
3360 | GFP_KERNEL, set->numa_node); |
3361 | if (!set->map[i].mq_map) | |
3362 | goto out_free_mq_map; | |
59388702 | 3363 | set->map[i].nr_queues = is_kdump_kernel() ? 1 : set->nr_hw_queues; |
b3c661b1 | 3364 | } |
bdd17e75 | 3365 | |
ebe8bddb | 3366 | ret = blk_mq_update_queue_map(set); |
da695ba2 CH |
3367 | if (ret) |
3368 | goto out_free_mq_map; | |
3369 | ||
79fab528 | 3370 | ret = blk_mq_alloc_map_and_requests(set); |
da695ba2 | 3371 | if (ret) |
bdd17e75 | 3372 | goto out_free_mq_map; |
24d2f903 | 3373 | |
0d2602ca JA |
3374 | mutex_init(&set->tag_list_lock); |
3375 | INIT_LIST_HEAD(&set->tag_list); | |
3376 | ||
24d2f903 | 3377 | return 0; |
bdd17e75 CH |
3378 | |
3379 | out_free_mq_map: | |
b3c661b1 JA |
3380 | for (i = 0; i < set->nr_maps; i++) { |
3381 | kfree(set->map[i].mq_map); | |
3382 | set->map[i].mq_map = NULL; | |
3383 | } | |
5676e7b6 RE |
3384 | kfree(set->tags); |
3385 | set->tags = NULL; | |
da695ba2 | 3386 | return ret; |
24d2f903 CH |
3387 | } |
3388 | EXPORT_SYMBOL(blk_mq_alloc_tag_set); | |
3389 | ||
3390 | void blk_mq_free_tag_set(struct blk_mq_tag_set *set) | |
3391 | { | |
b3c661b1 | 3392 | int i, j; |
24d2f903 | 3393 | |
f7e76dbc | 3394 | for (i = 0; i < set->nr_hw_queues; i++) |
cc71a6f4 | 3395 | blk_mq_free_map_and_requests(set, i); |
484b4061 | 3396 | |
b3c661b1 JA |
3397 | for (j = 0; j < set->nr_maps; j++) { |
3398 | kfree(set->map[j].mq_map); | |
3399 | set->map[j].mq_map = NULL; | |
3400 | } | |
bdd17e75 | 3401 | |
981bd189 | 3402 | kfree(set->tags); |
5676e7b6 | 3403 | set->tags = NULL; |
24d2f903 CH |
3404 | } |
3405 | EXPORT_SYMBOL(blk_mq_free_tag_set); | |
3406 | ||
e3a2b3f9 JA |
3407 | int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) |
3408 | { | |
3409 | struct blk_mq_tag_set *set = q->tag_set; | |
3410 | struct blk_mq_hw_ctx *hctx; | |
3411 | int i, ret; | |
3412 | ||
bd166ef1 | 3413 | if (!set) |
e3a2b3f9 JA |
3414 | return -EINVAL; |
3415 | ||
e5fa8140 AZ |
3416 | if (q->nr_requests == nr) |
3417 | return 0; | |
3418 | ||
70f36b60 | 3419 | blk_mq_freeze_queue(q); |
24f5a90f | 3420 | blk_mq_quiesce_queue(q); |
70f36b60 | 3421 | |
e3a2b3f9 JA |
3422 | ret = 0; |
3423 | queue_for_each_hw_ctx(q, hctx, i) { | |
e9137d4b KB |
3424 | if (!hctx->tags) |
3425 | continue; | |
bd166ef1 JA |
3426 | /* |
3427 | * If we're using an MQ scheduler, just update the scheduler | |
3428 | * queue depth. This is similar to what the old code would do. | |
3429 | */ | |
70f36b60 | 3430 | if (!hctx->sched_tags) { |
c2e82a23 | 3431 | ret = blk_mq_tag_update_depth(hctx, &hctx->tags, nr, |
70f36b60 JA |
3432 | false); |
3433 | } else { | |
3434 | ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags, | |
3435 | nr, true); | |
3436 | } | |
e3a2b3f9 JA |
3437 | if (ret) |
3438 | break; | |
77f1e0a5 JA |
3439 | if (q->elevator && q->elevator->type->ops.depth_updated) |
3440 | q->elevator->type->ops.depth_updated(hctx); | |
e3a2b3f9 JA |
3441 | } |
3442 | ||
3443 | if (!ret) | |
3444 | q->nr_requests = nr; | |
3445 | ||
24f5a90f | 3446 | blk_mq_unquiesce_queue(q); |
70f36b60 | 3447 | blk_mq_unfreeze_queue(q); |
70f36b60 | 3448 | |
e3a2b3f9 JA |
3449 | return ret; |
3450 | } | |
3451 | ||
d48ece20 JW |
3452 | /* |
3453 | * request_queue and elevator_type pair. | |
3454 | * It is just used by __blk_mq_update_nr_hw_queues to cache | |
3455 | * the elevator_type associated with a request_queue. | |
3456 | */ | |
3457 | struct blk_mq_qe_pair { | |
3458 | struct list_head node; | |
3459 | struct request_queue *q; | |
3460 | struct elevator_type *type; | |
3461 | }; | |
3462 | ||
3463 | /* | |
3464 | * Cache the elevator_type in qe pair list and switch the | |
3465 | * io scheduler to 'none' | |
3466 | */ | |
3467 | static bool blk_mq_elv_switch_none(struct list_head *head, | |
3468 | struct request_queue *q) | |
3469 | { | |
3470 | struct blk_mq_qe_pair *qe; | |
3471 | ||
3472 | if (!q->elevator) | |
3473 | return true; | |
3474 | ||
3475 | qe = kmalloc(sizeof(*qe), GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY); | |
3476 | if (!qe) | |
3477 | return false; | |
3478 | ||
3479 | INIT_LIST_HEAD(&qe->node); | |
3480 | qe->q = q; | |
3481 | qe->type = q->elevator->type; | |
3482 | list_add(&qe->node, head); | |
3483 | ||
3484 | mutex_lock(&q->sysfs_lock); | |
3485 | /* | |
3486 | * After elevator_switch_mq, the previous elevator_queue will be | |
3487 | * released by elevator_release. The reference of the io scheduler | |
3488 | * module get by elevator_get will also be put. So we need to get | |
3489 | * a reference of the io scheduler module here to prevent it to be | |
3490 | * removed. | |
3491 | */ | |
3492 | __module_get(qe->type->elevator_owner); | |
3493 | elevator_switch_mq(q, NULL); | |
3494 | mutex_unlock(&q->sysfs_lock); | |
3495 | ||
3496 | return true; | |
3497 | } | |
3498 | ||
3499 | static void blk_mq_elv_switch_back(struct list_head *head, | |
3500 | struct request_queue *q) | |
3501 | { | |
3502 | struct blk_mq_qe_pair *qe; | |
3503 | struct elevator_type *t = NULL; | |
3504 | ||
3505 | list_for_each_entry(qe, head, node) | |
3506 | if (qe->q == q) { | |
3507 | t = qe->type; | |
3508 | break; | |
3509 | } | |
3510 | ||
3511 | if (!t) | |
3512 | return; | |
3513 | ||
3514 | list_del(&qe->node); | |
3515 | kfree(qe); | |
3516 | ||
3517 | mutex_lock(&q->sysfs_lock); | |
3518 | elevator_switch_mq(q, t); | |
3519 | mutex_unlock(&q->sysfs_lock); | |
3520 | } | |
3521 | ||
e4dc2b32 KB |
3522 | static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, |
3523 | int nr_hw_queues) | |
868f2f0b KB |
3524 | { |
3525 | struct request_queue *q; | |
d48ece20 | 3526 | LIST_HEAD(head); |
e01ad46d | 3527 | int prev_nr_hw_queues; |
868f2f0b | 3528 | |
705cda97 BVA |
3529 | lockdep_assert_held(&set->tag_list_lock); |
3530 | ||
392546ae | 3531 | if (set->nr_maps == 1 && nr_hw_queues > nr_cpu_ids) |
868f2f0b | 3532 | nr_hw_queues = nr_cpu_ids; |
fe35ec58 WZ |
3533 | if (nr_hw_queues < 1) |
3534 | return; | |
3535 | if (set->nr_maps == 1 && nr_hw_queues == set->nr_hw_queues) | |
868f2f0b KB |
3536 | return; |
3537 | ||
3538 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
3539 | blk_mq_freeze_queue(q); | |
d48ece20 JW |
3540 | /* |
3541 | * Switch IO scheduler to 'none', cleaning up the data associated | |
3542 | * with the previous scheduler. We will switch back once we are done | |
3543 | * updating the new sw to hw queue mappings. | |
3544 | */ | |
3545 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
3546 | if (!blk_mq_elv_switch_none(&head, q)) | |
3547 | goto switch_back; | |
868f2f0b | 3548 | |
477e19de JW |
3549 | list_for_each_entry(q, &set->tag_list, tag_set_list) { |
3550 | blk_mq_debugfs_unregister_hctxs(q); | |
3551 | blk_mq_sysfs_unregister(q); | |
3552 | } | |
3553 | ||
a2584e43 | 3554 | prev_nr_hw_queues = set->nr_hw_queues; |
f7e76dbc BVA |
3555 | if (blk_mq_realloc_tag_set_tags(set, set->nr_hw_queues, nr_hw_queues) < |
3556 | 0) | |
3557 | goto reregister; | |
3558 | ||
868f2f0b | 3559 | set->nr_hw_queues = nr_hw_queues; |
e01ad46d | 3560 | fallback: |
aa880ad6 | 3561 | blk_mq_update_queue_map(set); |
868f2f0b KB |
3562 | list_for_each_entry(q, &set->tag_list, tag_set_list) { |
3563 | blk_mq_realloc_hw_ctxs(set, q); | |
e01ad46d JW |
3564 | if (q->nr_hw_queues != set->nr_hw_queues) { |
3565 | pr_warn("Increasing nr_hw_queues to %d fails, fallback to %d\n", | |
3566 | nr_hw_queues, prev_nr_hw_queues); | |
3567 | set->nr_hw_queues = prev_nr_hw_queues; | |
7d76f856 | 3568 | blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]); |
e01ad46d JW |
3569 | goto fallback; |
3570 | } | |
477e19de JW |
3571 | blk_mq_map_swqueue(q); |
3572 | } | |
3573 | ||
f7e76dbc | 3574 | reregister: |
477e19de JW |
3575 | list_for_each_entry(q, &set->tag_list, tag_set_list) { |
3576 | blk_mq_sysfs_register(q); | |
3577 | blk_mq_debugfs_register_hctxs(q); | |
868f2f0b KB |
3578 | } |
3579 | ||
d48ece20 JW |
3580 | switch_back: |
3581 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
3582 | blk_mq_elv_switch_back(&head, q); | |
3583 | ||
868f2f0b KB |
3584 | list_for_each_entry(q, &set->tag_list, tag_set_list) |
3585 | blk_mq_unfreeze_queue(q); | |
3586 | } | |
e4dc2b32 KB |
3587 | |
3588 | void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues) | |
3589 | { | |
3590 | mutex_lock(&set->tag_list_lock); | |
3591 | __blk_mq_update_nr_hw_queues(set, nr_hw_queues); | |
3592 | mutex_unlock(&set->tag_list_lock); | |
3593 | } | |
868f2f0b KB |
3594 | EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues); |
3595 | ||
34dbad5d OS |
3596 | /* Enable polling stats and return whether they were already enabled. */ |
3597 | static bool blk_poll_stats_enable(struct request_queue *q) | |
3598 | { | |
3599 | if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags) || | |
7dfdbc73 | 3600 | blk_queue_flag_test_and_set(QUEUE_FLAG_POLL_STATS, q)) |
34dbad5d OS |
3601 | return true; |
3602 | blk_stat_add_callback(q, q->poll_cb); | |
3603 | return false; | |
3604 | } | |
3605 | ||
3606 | static void blk_mq_poll_stats_start(struct request_queue *q) | |
3607 | { | |
3608 | /* | |
3609 | * We don't arm the callback if polling stats are not enabled or the | |
3610 | * callback is already active. | |
3611 | */ | |
3612 | if (!test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags) || | |
3613 | blk_stat_is_active(q->poll_cb)) | |
3614 | return; | |
3615 | ||
3616 | blk_stat_activate_msecs(q->poll_cb, 100); | |
3617 | } | |
3618 | ||
3619 | static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb) | |
3620 | { | |
3621 | struct request_queue *q = cb->data; | |
720b8ccc | 3622 | int bucket; |
34dbad5d | 3623 | |
720b8ccc SB |
3624 | for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS; bucket++) { |
3625 | if (cb->stat[bucket].nr_samples) | |
3626 | q->poll_stat[bucket] = cb->stat[bucket]; | |
3627 | } | |
34dbad5d OS |
3628 | } |
3629 | ||
64f1c21e | 3630 | static unsigned long blk_mq_poll_nsecs(struct request_queue *q, |
64f1c21e JA |
3631 | struct request *rq) |
3632 | { | |
64f1c21e | 3633 | unsigned long ret = 0; |
720b8ccc | 3634 | int bucket; |
64f1c21e JA |
3635 | |
3636 | /* | |
3637 | * If stats collection isn't on, don't sleep but turn it on for | |
3638 | * future users | |
3639 | */ | |
34dbad5d | 3640 | if (!blk_poll_stats_enable(q)) |
64f1c21e JA |
3641 | return 0; |
3642 | ||
64f1c21e JA |
3643 | /* |
3644 | * As an optimistic guess, use half of the mean service time | |
3645 | * for this type of request. We can (and should) make this smarter. | |
3646 | * For instance, if the completion latencies are tight, we can | |
3647 | * get closer than just half the mean. This is especially | |
3648 | * important on devices where the completion latencies are longer | |
720b8ccc SB |
3649 | * than ~10 usec. We do use the stats for the relevant IO size |
3650 | * if available which does lead to better estimates. | |
64f1c21e | 3651 | */ |
720b8ccc SB |
3652 | bucket = blk_mq_poll_stats_bkt(rq); |
3653 | if (bucket < 0) | |
3654 | return ret; | |
3655 | ||
3656 | if (q->poll_stat[bucket].nr_samples) | |
3657 | ret = (q->poll_stat[bucket].mean + 1) / 2; | |
64f1c21e JA |
3658 | |
3659 | return ret; | |
3660 | } | |
3661 | ||
06426adf JA |
3662 | static bool blk_mq_poll_hybrid_sleep(struct request_queue *q, |
3663 | struct request *rq) | |
3664 | { | |
3665 | struct hrtimer_sleeper hs; | |
3666 | enum hrtimer_mode mode; | |
64f1c21e | 3667 | unsigned int nsecs; |
06426adf JA |
3668 | ktime_t kt; |
3669 | ||
76a86f9d | 3670 | if (rq->rq_flags & RQF_MQ_POLL_SLEPT) |
64f1c21e JA |
3671 | return false; |
3672 | ||
3673 | /* | |
1052b8ac | 3674 | * If we get here, hybrid polling is enabled. Hence poll_nsec can be: |
64f1c21e | 3675 | * |
64f1c21e JA |
3676 | * 0: use half of prev avg |
3677 | * >0: use this specific value | |
3678 | */ | |
1052b8ac | 3679 | if (q->poll_nsec > 0) |
64f1c21e JA |
3680 | nsecs = q->poll_nsec; |
3681 | else | |
cae740a0 | 3682 | nsecs = blk_mq_poll_nsecs(q, rq); |
64f1c21e JA |
3683 | |
3684 | if (!nsecs) | |
06426adf JA |
3685 | return false; |
3686 | ||
76a86f9d | 3687 | rq->rq_flags |= RQF_MQ_POLL_SLEPT; |
06426adf JA |
3688 | |
3689 | /* | |
3690 | * This will be replaced with the stats tracking code, using | |
3691 | * 'avg_completion_time / 2' as the pre-sleep target. | |
3692 | */ | |
8b0e1953 | 3693 | kt = nsecs; |
06426adf JA |
3694 | |
3695 | mode = HRTIMER_MODE_REL; | |
dbc1625f | 3696 | hrtimer_init_sleeper_on_stack(&hs, CLOCK_MONOTONIC, mode); |
06426adf JA |
3697 | hrtimer_set_expires(&hs.timer, kt); |
3698 | ||
06426adf | 3699 | do { |
5a61c363 | 3700 | if (blk_mq_rq_state(rq) == MQ_RQ_COMPLETE) |
06426adf JA |
3701 | break; |
3702 | set_current_state(TASK_UNINTERRUPTIBLE); | |
9dd8813e | 3703 | hrtimer_sleeper_start_expires(&hs, mode); |
06426adf JA |
3704 | if (hs.task) |
3705 | io_schedule(); | |
3706 | hrtimer_cancel(&hs.timer); | |
3707 | mode = HRTIMER_MODE_ABS; | |
3708 | } while (hs.task && !signal_pending(current)); | |
3709 | ||
3710 | __set_current_state(TASK_RUNNING); | |
3711 | destroy_hrtimer_on_stack(&hs.timer); | |
3712 | return true; | |
3713 | } | |
3714 | ||
1052b8ac JA |
3715 | static bool blk_mq_poll_hybrid(struct request_queue *q, |
3716 | struct blk_mq_hw_ctx *hctx, blk_qc_t cookie) | |
bbd7bb70 | 3717 | { |
1052b8ac JA |
3718 | struct request *rq; |
3719 | ||
29ece8b4 | 3720 | if (q->poll_nsec == BLK_MQ_POLL_CLASSIC) |
1052b8ac JA |
3721 | return false; |
3722 | ||
3723 | if (!blk_qc_t_is_internal(cookie)) | |
3724 | rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie)); | |
3725 | else { | |
3726 | rq = blk_mq_tag_to_rq(hctx->sched_tags, blk_qc_t_to_tag(cookie)); | |
3727 | /* | |
3728 | * With scheduling, if the request has completed, we'll | |
3729 | * get a NULL return here, as we clear the sched tag when | |
3730 | * that happens. The request still remains valid, like always, | |
3731 | * so we should be safe with just the NULL check. | |
3732 | */ | |
3733 | if (!rq) | |
3734 | return false; | |
3735 | } | |
3736 | ||
cae740a0 | 3737 | return blk_mq_poll_hybrid_sleep(q, rq); |
1052b8ac JA |
3738 | } |
3739 | ||
529262d5 CH |
3740 | /** |
3741 | * blk_poll - poll for IO completions | |
3742 | * @q: the queue | |
3743 | * @cookie: cookie passed back at IO submission time | |
3744 | * @spin: whether to spin for completions | |
3745 | * | |
3746 | * Description: | |
3747 | * Poll for completions on the passed in queue. Returns number of | |
3748 | * completed entries found. If @spin is true, then blk_poll will continue | |
3749 | * looping until at least one completion is found, unless the task is | |
3750 | * otherwise marked running (or we need to reschedule). | |
3751 | */ | |
3752 | int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin) | |
1052b8ac JA |
3753 | { |
3754 | struct blk_mq_hw_ctx *hctx; | |
bbd7bb70 JA |
3755 | long state; |
3756 | ||
529262d5 CH |
3757 | if (!blk_qc_t_valid(cookie) || |
3758 | !test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) | |
1052b8ac JA |
3759 | return 0; |
3760 | ||
529262d5 CH |
3761 | if (current->plug) |
3762 | blk_flush_plug_list(current->plug, false); | |
3763 | ||
1052b8ac JA |
3764 | hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)]; |
3765 | ||
06426adf JA |
3766 | /* |
3767 | * If we sleep, have the caller restart the poll loop to reset | |
3768 | * the state. Like for the other success return cases, the | |
3769 | * caller is responsible for checking if the IO completed. If | |
3770 | * the IO isn't complete, we'll get called again and will go | |
3771 | * straight to the busy poll loop. | |
3772 | */ | |
1052b8ac | 3773 | if (blk_mq_poll_hybrid(q, hctx, cookie)) |
85f4d4b6 | 3774 | return 1; |
06426adf | 3775 | |
bbd7bb70 JA |
3776 | hctx->poll_considered++; |
3777 | ||
3778 | state = current->state; | |
aa61bec3 | 3779 | do { |
bbd7bb70 JA |
3780 | int ret; |
3781 | ||
3782 | hctx->poll_invoked++; | |
3783 | ||
9743139c | 3784 | ret = q->mq_ops->poll(hctx); |
bbd7bb70 JA |
3785 | if (ret > 0) { |
3786 | hctx->poll_success++; | |
849a3700 | 3787 | __set_current_state(TASK_RUNNING); |
85f4d4b6 | 3788 | return ret; |
bbd7bb70 JA |
3789 | } |
3790 | ||
3791 | if (signal_pending_state(state, current)) | |
849a3700 | 3792 | __set_current_state(TASK_RUNNING); |
bbd7bb70 JA |
3793 | |
3794 | if (current->state == TASK_RUNNING) | |
85f4d4b6 | 3795 | return 1; |
0a1b8b87 | 3796 | if (ret < 0 || !spin) |
bbd7bb70 JA |
3797 | break; |
3798 | cpu_relax(); | |
aa61bec3 | 3799 | } while (!need_resched()); |
bbd7bb70 | 3800 | |
67b4110f | 3801 | __set_current_state(TASK_RUNNING); |
85f4d4b6 | 3802 | return 0; |
bbd7bb70 | 3803 | } |
529262d5 | 3804 | EXPORT_SYMBOL_GPL(blk_poll); |
bbd7bb70 | 3805 | |
9cf2bab6 JA |
3806 | unsigned int blk_mq_rq_cpu(struct request *rq) |
3807 | { | |
3808 | return rq->mq_ctx->cpu; | |
3809 | } | |
3810 | EXPORT_SYMBOL(blk_mq_rq_cpu); | |
3811 | ||
320ae51f JA |
3812 | static int __init blk_mq_init(void) |
3813 | { | |
c3077b5d CH |
3814 | int i; |
3815 | ||
3816 | for_each_possible_cpu(i) | |
3817 | INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i)); | |
3818 | open_softirq(BLOCK_SOFTIRQ, blk_done_softirq); | |
3819 | ||
3820 | cpuhp_setup_state_nocalls(CPUHP_BLOCK_SOFTIRQ_DEAD, | |
3821 | "block/softirq:dead", NULL, | |
3822 | blk_softirq_cpu_dead); | |
9467f859 TG |
3823 | cpuhp_setup_state_multi(CPUHP_BLK_MQ_DEAD, "block/mq:dead", NULL, |
3824 | blk_mq_hctx_notify_dead); | |
bf0beec0 ML |
3825 | cpuhp_setup_state_multi(CPUHP_AP_BLK_MQ_ONLINE, "block/mq:online", |
3826 | blk_mq_hctx_notify_online, | |
3827 | blk_mq_hctx_notify_offline); | |
320ae51f JA |
3828 | return 0; |
3829 | } | |
3830 | subsys_initcall(blk_mq_init); |