Commit | Line | Data |
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bd166ef1 JA |
1 | /* |
2 | * blk-mq scheduling framework | |
3 | * | |
4 | * Copyright (C) 2016 Jens Axboe | |
5 | */ | |
6 | #include <linux/kernel.h> | |
7 | #include <linux/module.h> | |
8 | #include <linux/blk-mq.h> | |
9 | ||
10 | #include <trace/events/block.h> | |
11 | ||
12 | #include "blk.h" | |
13 | #include "blk-mq.h" | |
14 | #include "blk-mq-sched.h" | |
15 | #include "blk-mq-tag.h" | |
16 | #include "blk-wbt.h" | |
17 | ||
18 | void blk_mq_sched_free_hctx_data(struct request_queue *q, | |
19 | void (*exit)(struct blk_mq_hw_ctx *)) | |
20 | { | |
21 | struct blk_mq_hw_ctx *hctx; | |
22 | int i; | |
23 | ||
24 | queue_for_each_hw_ctx(q, hctx, i) { | |
25 | if (exit && hctx->sched_data) | |
26 | exit(hctx); | |
27 | kfree(hctx->sched_data); | |
28 | hctx->sched_data = NULL; | |
29 | } | |
30 | } | |
31 | EXPORT_SYMBOL_GPL(blk_mq_sched_free_hctx_data); | |
32 | ||
bd166ef1 | 33 | static void __blk_mq_sched_assign_ioc(struct request_queue *q, |
f1ba8261 PV |
34 | struct request *rq, |
35 | struct bio *bio, | |
36 | struct io_context *ioc) | |
bd166ef1 JA |
37 | { |
38 | struct io_cq *icq; | |
39 | ||
40 | spin_lock_irq(q->queue_lock); | |
41 | icq = ioc_lookup_icq(ioc, q); | |
42 | spin_unlock_irq(q->queue_lock); | |
43 | ||
44 | if (!icq) { | |
45 | icq = ioc_create_icq(ioc, q, GFP_ATOMIC); | |
46 | if (!icq) | |
47 | return; | |
48 | } | |
49 | ||
50 | rq->elv.icq = icq; | |
f1ba8261 | 51 | if (!blk_mq_sched_get_rq_priv(q, rq, bio)) { |
bd166ef1 JA |
52 | rq->rq_flags |= RQF_ELVPRIV; |
53 | get_io_context(icq->ioc); | |
54 | return; | |
55 | } | |
56 | ||
57 | rq->elv.icq = NULL; | |
58 | } | |
59 | ||
60 | static void blk_mq_sched_assign_ioc(struct request_queue *q, | |
61 | struct request *rq, struct bio *bio) | |
62 | { | |
63 | struct io_context *ioc; | |
64 | ||
65 | ioc = rq_ioc(bio); | |
66 | if (ioc) | |
f1ba8261 | 67 | __blk_mq_sched_assign_ioc(q, rq, bio, ioc); |
bd166ef1 JA |
68 | } |
69 | ||
70 | struct request *blk_mq_sched_get_request(struct request_queue *q, | |
71 | struct bio *bio, | |
72 | unsigned int op, | |
73 | struct blk_mq_alloc_data *data) | |
74 | { | |
75 | struct elevator_queue *e = q->elevator; | |
bd166ef1 | 76 | struct request *rq; |
bd166ef1 JA |
77 | |
78 | blk_queue_enter_live(q); | |
6d2809d5 OS |
79 | data->q = q; |
80 | if (likely(!data->ctx)) | |
81 | data->ctx = blk_mq_get_ctx(q); | |
82 | if (likely(!data->hctx)) | |
83 | data->hctx = blk_mq_map_queue(q, data->ctx->cpu); | |
bd166ef1 | 84 | |
9f2779bf | 85 | if (e) { |
bd166ef1 JA |
86 | data->flags |= BLK_MQ_REQ_INTERNAL; |
87 | ||
88 | /* | |
89 | * Flush requests are special and go directly to the | |
90 | * dispatch list. | |
91 | */ | |
f73f44eb | 92 | if (!op_is_flush(op) && e->type->ops.mq.get_request) { |
bd166ef1 JA |
93 | rq = e->type->ops.mq.get_request(q, op, data); |
94 | if (rq) | |
95 | rq->rq_flags |= RQF_QUEUED; | |
96 | } else | |
97 | rq = __blk_mq_alloc_request(data, op); | |
98 | } else { | |
99 | rq = __blk_mq_alloc_request(data, op); | |
bd166ef1 JA |
100 | } |
101 | ||
102 | if (rq) { | |
f73f44eb | 103 | if (!op_is_flush(op)) { |
bd166ef1 JA |
104 | rq->elv.icq = NULL; |
105 | if (e && e->type->icq_cache) | |
106 | blk_mq_sched_assign_ioc(q, rq, bio); | |
107 | } | |
108 | data->hctx->queued++; | |
109 | return rq; | |
110 | } | |
111 | ||
112 | blk_queue_exit(q); | |
113 | return NULL; | |
114 | } | |
115 | ||
116 | void blk_mq_sched_put_request(struct request *rq) | |
117 | { | |
118 | struct request_queue *q = rq->q; | |
119 | struct elevator_queue *e = q->elevator; | |
120 | ||
121 | if (rq->rq_flags & RQF_ELVPRIV) { | |
122 | blk_mq_sched_put_rq_priv(rq->q, rq); | |
123 | if (rq->elv.icq) { | |
124 | put_io_context(rq->elv.icq->ioc); | |
125 | rq->elv.icq = NULL; | |
126 | } | |
127 | } | |
128 | ||
129 | if ((rq->rq_flags & RQF_QUEUED) && e && e->type->ops.mq.put_request) | |
130 | e->type->ops.mq.put_request(rq); | |
131 | else | |
132 | blk_mq_finish_request(rq); | |
133 | } | |
134 | ||
135 | void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx) | |
136 | { | |
81380ca1 OS |
137 | struct request_queue *q = hctx->queue; |
138 | struct elevator_queue *e = q->elevator; | |
64765a75 JA |
139 | const bool has_sched_dispatch = e && e->type->ops.mq.dispatch_request; |
140 | bool did_work = false; | |
bd166ef1 JA |
141 | LIST_HEAD(rq_list); |
142 | ||
143 | if (unlikely(blk_mq_hctx_stopped(hctx))) | |
144 | return; | |
145 | ||
146 | hctx->run++; | |
147 | ||
148 | /* | |
149 | * If we have previous entries on our dispatch list, grab them first for | |
150 | * more fair dispatch. | |
151 | */ | |
152 | if (!list_empty_careful(&hctx->dispatch)) { | |
153 | spin_lock(&hctx->lock); | |
154 | if (!list_empty(&hctx->dispatch)) | |
155 | list_splice_init(&hctx->dispatch, &rq_list); | |
156 | spin_unlock(&hctx->lock); | |
157 | } | |
158 | ||
159 | /* | |
160 | * Only ask the scheduler for requests, if we didn't have residual | |
161 | * requests from the dispatch list. This is to avoid the case where | |
162 | * we only ever dispatch a fraction of the requests available because | |
163 | * of low device queue depth. Once we pull requests out of the IO | |
164 | * scheduler, we can no longer merge or sort them. So it's best to | |
165 | * leave them there for as long as we can. Mark the hw queue as | |
166 | * needing a restart in that case. | |
167 | */ | |
c13660a0 | 168 | if (!list_empty(&rq_list)) { |
d38d3515 | 169 | blk_mq_sched_mark_restart_hctx(hctx); |
81380ca1 | 170 | did_work = blk_mq_dispatch_rq_list(q, &rq_list); |
64765a75 | 171 | } else if (!has_sched_dispatch) { |
c13660a0 | 172 | blk_mq_flush_busy_ctxs(hctx, &rq_list); |
81380ca1 | 173 | blk_mq_dispatch_rq_list(q, &rq_list); |
64765a75 JA |
174 | } |
175 | ||
176 | /* | |
177 | * We want to dispatch from the scheduler if we had no work left | |
178 | * on the dispatch list, OR if we did have work but weren't able | |
179 | * to make progress. | |
180 | */ | |
181 | if (!did_work && has_sched_dispatch) { | |
c13660a0 JA |
182 | do { |
183 | struct request *rq; | |
184 | ||
185 | rq = e->type->ops.mq.dispatch_request(hctx); | |
186 | if (!rq) | |
187 | break; | |
188 | list_add(&rq->queuelist, &rq_list); | |
81380ca1 | 189 | } while (blk_mq_dispatch_rq_list(q, &rq_list)); |
c13660a0 | 190 | } |
bd166ef1 JA |
191 | } |
192 | ||
e4d750c9 JA |
193 | bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio, |
194 | struct request **merged_request) | |
bd166ef1 JA |
195 | { |
196 | struct request *rq; | |
bd166ef1 | 197 | |
34fe7c05 CH |
198 | switch (elv_merge(q, &rq, bio)) { |
199 | case ELEVATOR_BACK_MERGE: | |
bd166ef1 JA |
200 | if (!blk_mq_sched_allow_merge(q, rq, bio)) |
201 | return false; | |
34fe7c05 CH |
202 | if (!bio_attempt_back_merge(q, rq, bio)) |
203 | return false; | |
204 | *merged_request = attempt_back_merge(q, rq); | |
205 | if (!*merged_request) | |
206 | elv_merged_request(q, rq, ELEVATOR_BACK_MERGE); | |
207 | return true; | |
208 | case ELEVATOR_FRONT_MERGE: | |
bd166ef1 JA |
209 | if (!blk_mq_sched_allow_merge(q, rq, bio)) |
210 | return false; | |
34fe7c05 CH |
211 | if (!bio_attempt_front_merge(q, rq, bio)) |
212 | return false; | |
213 | *merged_request = attempt_front_merge(q, rq); | |
214 | if (!*merged_request) | |
215 | elv_merged_request(q, rq, ELEVATOR_FRONT_MERGE); | |
216 | return true; | |
217 | default: | |
218 | return false; | |
bd166ef1 | 219 | } |
bd166ef1 JA |
220 | } |
221 | EXPORT_SYMBOL_GPL(blk_mq_sched_try_merge); | |
222 | ||
223 | bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio) | |
224 | { | |
225 | struct elevator_queue *e = q->elevator; | |
226 | ||
227 | if (e->type->ops.mq.bio_merge) { | |
228 | struct blk_mq_ctx *ctx = blk_mq_get_ctx(q); | |
229 | struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); | |
230 | ||
231 | blk_mq_put_ctx(ctx); | |
232 | return e->type->ops.mq.bio_merge(hctx, bio); | |
233 | } | |
234 | ||
235 | return false; | |
236 | } | |
237 | ||
238 | bool blk_mq_sched_try_insert_merge(struct request_queue *q, struct request *rq) | |
239 | { | |
240 | return rq_mergeable(rq) && elv_attempt_insert_merge(q, rq); | |
241 | } | |
242 | EXPORT_SYMBOL_GPL(blk_mq_sched_try_insert_merge); | |
243 | ||
244 | void blk_mq_sched_request_inserted(struct request *rq) | |
245 | { | |
246 | trace_block_rq_insert(rq->q, rq); | |
247 | } | |
248 | EXPORT_SYMBOL_GPL(blk_mq_sched_request_inserted); | |
249 | ||
0cacba6c OS |
250 | static bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx, |
251 | struct request *rq) | |
bd166ef1 JA |
252 | { |
253 | if (rq->tag == -1) { | |
254 | rq->rq_flags |= RQF_SORTED; | |
255 | return false; | |
256 | } | |
257 | ||
258 | /* | |
259 | * If we already have a real request tag, send directly to | |
260 | * the dispatch list. | |
261 | */ | |
262 | spin_lock(&hctx->lock); | |
263 | list_add(&rq->queuelist, &hctx->dispatch); | |
264 | spin_unlock(&hctx->lock); | |
265 | return true; | |
266 | } | |
bd166ef1 | 267 | |
6d8c6c0f | 268 | static bool blk_mq_sched_restart_hctx(struct blk_mq_hw_ctx *hctx) |
50e1dab8 JA |
269 | { |
270 | if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) { | |
271 | clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); | |
6d8c6c0f | 272 | if (blk_mq_hctx_has_pending(hctx)) { |
50e1dab8 | 273 | blk_mq_run_hw_queue(hctx, true); |
6d8c6c0f BVA |
274 | return true; |
275 | } | |
50e1dab8 | 276 | } |
6d8c6c0f | 277 | return false; |
50e1dab8 JA |
278 | } |
279 | ||
6d8c6c0f BVA |
280 | /** |
281 | * list_for_each_entry_rcu_rr - iterate in a round-robin fashion over rcu list | |
282 | * @pos: loop cursor. | |
283 | * @skip: the list element that will not be examined. Iteration starts at | |
284 | * @skip->next. | |
285 | * @head: head of the list to examine. This list must have at least one | |
286 | * element, namely @skip. | |
287 | * @member: name of the list_head structure within typeof(*pos). | |
288 | */ | |
289 | #define list_for_each_entry_rcu_rr(pos, skip, head, member) \ | |
290 | for ((pos) = (skip); \ | |
291 | (pos = (pos)->member.next != (head) ? list_entry_rcu( \ | |
292 | (pos)->member.next, typeof(*pos), member) : \ | |
293 | list_entry_rcu((pos)->member.next->next, typeof(*pos), member)), \ | |
294 | (pos) != (skip); ) | |
50e1dab8 | 295 | |
6d8c6c0f BVA |
296 | /* |
297 | * Called after a driver tag has been freed to check whether a hctx needs to | |
298 | * be restarted. Restarts @hctx if its tag set is not shared. Restarts hardware | |
299 | * queues in a round-robin fashion if the tag set of @hctx is shared with other | |
300 | * hardware queues. | |
301 | */ | |
302 | void blk_mq_sched_restart(struct blk_mq_hw_ctx *const hctx) | |
303 | { | |
304 | struct blk_mq_tags *const tags = hctx->tags; | |
305 | struct blk_mq_tag_set *const set = hctx->queue->tag_set; | |
306 | struct request_queue *const queue = hctx->queue, *q; | |
307 | struct blk_mq_hw_ctx *hctx2; | |
308 | unsigned int i, j; | |
309 | ||
310 | if (set->flags & BLK_MQ_F_TAG_SHARED) { | |
311 | rcu_read_lock(); | |
312 | list_for_each_entry_rcu_rr(q, queue, &set->tag_list, | |
313 | tag_set_list) { | |
314 | queue_for_each_hw_ctx(q, hctx2, i) | |
315 | if (hctx2->tags == tags && | |
316 | blk_mq_sched_restart_hctx(hctx2)) | |
317 | goto done; | |
318 | } | |
319 | j = hctx->queue_num + 1; | |
320 | for (i = 0; i < queue->nr_hw_queues; i++, j++) { | |
321 | if (j == queue->nr_hw_queues) | |
322 | j = 0; | |
323 | hctx2 = queue->queue_hw_ctx[j]; | |
324 | if (hctx2->tags == tags && | |
325 | blk_mq_sched_restart_hctx(hctx2)) | |
326 | break; | |
d38d3515 | 327 | } |
6d8c6c0f BVA |
328 | done: |
329 | rcu_read_unlock(); | |
d38d3515 | 330 | } else { |
50e1dab8 | 331 | blk_mq_sched_restart_hctx(hctx); |
50e1dab8 JA |
332 | } |
333 | } | |
334 | ||
bd6737f1 JA |
335 | /* |
336 | * Add flush/fua to the queue. If we fail getting a driver tag, then | |
337 | * punt to the requeue list. Requeue will re-invoke us from a context | |
338 | * that's safe to block from. | |
339 | */ | |
340 | static void blk_mq_sched_insert_flush(struct blk_mq_hw_ctx *hctx, | |
341 | struct request *rq, bool can_block) | |
342 | { | |
343 | if (blk_mq_get_driver_tag(rq, &hctx, can_block)) { | |
344 | blk_insert_flush(rq); | |
345 | blk_mq_run_hw_queue(hctx, true); | |
346 | } else | |
c7a571b4 | 347 | blk_mq_add_to_requeue_list(rq, false, true); |
bd6737f1 JA |
348 | } |
349 | ||
350 | void blk_mq_sched_insert_request(struct request *rq, bool at_head, | |
351 | bool run_queue, bool async, bool can_block) | |
352 | { | |
353 | struct request_queue *q = rq->q; | |
354 | struct elevator_queue *e = q->elevator; | |
355 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
356 | struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); | |
357 | ||
f3a8ab7d | 358 | if (rq->tag == -1 && op_is_flush(rq->cmd_flags)) { |
bd6737f1 JA |
359 | blk_mq_sched_insert_flush(hctx, rq, can_block); |
360 | return; | |
361 | } | |
362 | ||
0cacba6c OS |
363 | if (e && blk_mq_sched_bypass_insert(hctx, rq)) |
364 | goto run; | |
365 | ||
bd6737f1 JA |
366 | if (e && e->type->ops.mq.insert_requests) { |
367 | LIST_HEAD(list); | |
368 | ||
369 | list_add(&rq->queuelist, &list); | |
370 | e->type->ops.mq.insert_requests(hctx, &list, at_head); | |
371 | } else { | |
372 | spin_lock(&ctx->lock); | |
373 | __blk_mq_insert_request(hctx, rq, at_head); | |
374 | spin_unlock(&ctx->lock); | |
375 | } | |
376 | ||
0cacba6c | 377 | run: |
bd6737f1 JA |
378 | if (run_queue) |
379 | blk_mq_run_hw_queue(hctx, async); | |
380 | } | |
381 | ||
382 | void blk_mq_sched_insert_requests(struct request_queue *q, | |
383 | struct blk_mq_ctx *ctx, | |
384 | struct list_head *list, bool run_queue_async) | |
385 | { | |
386 | struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); | |
387 | struct elevator_queue *e = hctx->queue->elevator; | |
388 | ||
0cacba6c OS |
389 | if (e) { |
390 | struct request *rq, *next; | |
391 | ||
392 | /* | |
393 | * We bypass requests that already have a driver tag assigned, | |
394 | * which should only be flushes. Flushes are only ever inserted | |
395 | * as single requests, so we shouldn't ever hit the | |
396 | * WARN_ON_ONCE() below (but let's handle it just in case). | |
397 | */ | |
398 | list_for_each_entry_safe(rq, next, list, queuelist) { | |
399 | if (WARN_ON_ONCE(rq->tag != -1)) { | |
400 | list_del_init(&rq->queuelist); | |
401 | blk_mq_sched_bypass_insert(hctx, rq); | |
402 | } | |
403 | } | |
404 | } | |
405 | ||
bd6737f1 JA |
406 | if (e && e->type->ops.mq.insert_requests) |
407 | e->type->ops.mq.insert_requests(hctx, list, false); | |
408 | else | |
409 | blk_mq_insert_requests(hctx, ctx, list); | |
410 | ||
411 | blk_mq_run_hw_queue(hctx, run_queue_async); | |
412 | } | |
413 | ||
bd166ef1 JA |
414 | static void blk_mq_sched_free_tags(struct blk_mq_tag_set *set, |
415 | struct blk_mq_hw_ctx *hctx, | |
416 | unsigned int hctx_idx) | |
417 | { | |
418 | if (hctx->sched_tags) { | |
419 | blk_mq_free_rqs(set, hctx->sched_tags, hctx_idx); | |
420 | blk_mq_free_rq_map(hctx->sched_tags); | |
421 | hctx->sched_tags = NULL; | |
422 | } | |
423 | } | |
424 | ||
6917ff0b OS |
425 | static int blk_mq_sched_alloc_tags(struct request_queue *q, |
426 | struct blk_mq_hw_ctx *hctx, | |
427 | unsigned int hctx_idx) | |
428 | { | |
429 | struct blk_mq_tag_set *set = q->tag_set; | |
430 | int ret; | |
431 | ||
432 | hctx->sched_tags = blk_mq_alloc_rq_map(set, hctx_idx, q->nr_requests, | |
433 | set->reserved_tags); | |
434 | if (!hctx->sched_tags) | |
435 | return -ENOMEM; | |
436 | ||
437 | ret = blk_mq_alloc_rqs(set, hctx->sched_tags, hctx_idx, q->nr_requests); | |
438 | if (ret) | |
439 | blk_mq_sched_free_tags(set, hctx, hctx_idx); | |
440 | ||
441 | return ret; | |
442 | } | |
443 | ||
54d5329d | 444 | static void blk_mq_sched_tags_teardown(struct request_queue *q) |
bd166ef1 JA |
445 | { |
446 | struct blk_mq_tag_set *set = q->tag_set; | |
447 | struct blk_mq_hw_ctx *hctx; | |
6917ff0b OS |
448 | int i; |
449 | ||
450 | queue_for_each_hw_ctx(q, hctx, i) | |
451 | blk_mq_sched_free_tags(set, hctx, i); | |
452 | } | |
453 | ||
93252632 OS |
454 | int blk_mq_sched_init_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx, |
455 | unsigned int hctx_idx) | |
456 | { | |
457 | struct elevator_queue *e = q->elevator; | |
ee056f98 | 458 | int ret; |
93252632 OS |
459 | |
460 | if (!e) | |
461 | return 0; | |
462 | ||
ee056f98 OS |
463 | ret = blk_mq_sched_alloc_tags(q, hctx, hctx_idx); |
464 | if (ret) | |
465 | return ret; | |
466 | ||
467 | if (e->type->ops.mq.init_hctx) { | |
468 | ret = e->type->ops.mq.init_hctx(hctx, hctx_idx); | |
469 | if (ret) { | |
470 | blk_mq_sched_free_tags(q->tag_set, hctx, hctx_idx); | |
471 | return ret; | |
472 | } | |
473 | } | |
474 | ||
475 | return 0; | |
93252632 OS |
476 | } |
477 | ||
478 | void blk_mq_sched_exit_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx, | |
479 | unsigned int hctx_idx) | |
480 | { | |
481 | struct elevator_queue *e = q->elevator; | |
482 | ||
483 | if (!e) | |
484 | return; | |
485 | ||
ee056f98 OS |
486 | if (e->type->ops.mq.exit_hctx && hctx->sched_data) { |
487 | e->type->ops.mq.exit_hctx(hctx, hctx_idx); | |
488 | hctx->sched_data = NULL; | |
489 | } | |
490 | ||
93252632 OS |
491 | blk_mq_sched_free_tags(q->tag_set, hctx, hctx_idx); |
492 | } | |
493 | ||
6917ff0b OS |
494 | int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e) |
495 | { | |
496 | struct blk_mq_hw_ctx *hctx; | |
ee056f98 | 497 | struct elevator_queue *eq; |
6917ff0b OS |
498 | unsigned int i; |
499 | int ret; | |
500 | ||
501 | if (!e) { | |
502 | q->elevator = NULL; | |
503 | return 0; | |
504 | } | |
bd166ef1 JA |
505 | |
506 | /* | |
507 | * Default to 256, since we don't split into sync/async like the | |
508 | * old code did. Additionally, this is a per-hw queue depth. | |
509 | */ | |
510 | q->nr_requests = 2 * BLKDEV_MAX_RQ; | |
511 | ||
bd166ef1 | 512 | queue_for_each_hw_ctx(q, hctx, i) { |
6917ff0b | 513 | ret = blk_mq_sched_alloc_tags(q, hctx, i); |
bd166ef1 | 514 | if (ret) |
6917ff0b | 515 | goto err; |
bd166ef1 JA |
516 | } |
517 | ||
6917ff0b OS |
518 | ret = e->ops.mq.init_sched(q, e); |
519 | if (ret) | |
520 | goto err; | |
bd166ef1 | 521 | |
ee056f98 OS |
522 | if (e->ops.mq.init_hctx) { |
523 | queue_for_each_hw_ctx(q, hctx, i) { | |
524 | ret = e->ops.mq.init_hctx(hctx, i); | |
525 | if (ret) { | |
526 | eq = q->elevator; | |
527 | blk_mq_exit_sched(q, eq); | |
528 | kobject_put(&eq->kobj); | |
529 | return ret; | |
530 | } | |
531 | } | |
532 | } | |
533 | ||
bd166ef1 | 534 | return 0; |
bd166ef1 | 535 | |
6917ff0b | 536 | err: |
54d5329d OS |
537 | blk_mq_sched_tags_teardown(q); |
538 | q->elevator = NULL; | |
6917ff0b | 539 | return ret; |
bd166ef1 | 540 | } |
d3484991 | 541 | |
54d5329d OS |
542 | void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e) |
543 | { | |
ee056f98 OS |
544 | struct blk_mq_hw_ctx *hctx; |
545 | unsigned int i; | |
546 | ||
547 | if (e->type->ops.mq.exit_hctx) { | |
548 | queue_for_each_hw_ctx(q, hctx, i) { | |
549 | if (hctx->sched_data) { | |
550 | e->type->ops.mq.exit_hctx(hctx, i); | |
551 | hctx->sched_data = NULL; | |
552 | } | |
553 | } | |
554 | } | |
54d5329d OS |
555 | if (e->type->ops.mq.exit_sched) |
556 | e->type->ops.mq.exit_sched(e); | |
557 | blk_mq_sched_tags_teardown(q); | |
558 | q->elevator = NULL; | |
559 | } | |
560 | ||
d3484991 JA |
561 | int blk_mq_sched_init(struct request_queue *q) |
562 | { | |
563 | int ret; | |
564 | ||
d3484991 JA |
565 | mutex_lock(&q->sysfs_lock); |
566 | ret = elevator_init(q, NULL); | |
567 | mutex_unlock(&q->sysfs_lock); | |
568 | ||
569 | return ret; | |
570 | } |