Commit | Line | Data |
---|---|---|
75bb4625 JA |
1 | /* |
2 | * Block multiqueue core code | |
3 | * | |
4 | * Copyright (C) 2013-2014 Jens Axboe | |
5 | * Copyright (C) 2013-2014 Christoph Hellwig | |
6 | */ | |
320ae51f JA |
7 | #include <linux/kernel.h> |
8 | #include <linux/module.h> | |
9 | #include <linux/backing-dev.h> | |
10 | #include <linux/bio.h> | |
11 | #include <linux/blkdev.h> | |
f75782e4 | 12 | #include <linux/kmemleak.h> |
320ae51f JA |
13 | #include <linux/mm.h> |
14 | #include <linux/init.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/workqueue.h> | |
17 | #include <linux/smp.h> | |
18 | #include <linux/llist.h> | |
19 | #include <linux/list_sort.h> | |
20 | #include <linux/cpu.h> | |
21 | #include <linux/cache.h> | |
22 | #include <linux/sched/sysctl.h> | |
105ab3d8 | 23 | #include <linux/sched/topology.h> |
320ae51f | 24 | #include <linux/delay.h> |
aedcd72f | 25 | #include <linux/crash_dump.h> |
88c7b2b7 | 26 | #include <linux/prefetch.h> |
320ae51f JA |
27 | |
28 | #include <trace/events/block.h> | |
29 | ||
30 | #include <linux/blk-mq.h> | |
31 | #include "blk.h" | |
32 | #include "blk-mq.h" | |
33 | #include "blk-mq-tag.h" | |
cf43e6be | 34 | #include "blk-stat.h" |
87760e5e | 35 | #include "blk-wbt.h" |
bd166ef1 | 36 | #include "blk-mq-sched.h" |
320ae51f JA |
37 | |
38 | static DEFINE_MUTEX(all_q_mutex); | |
39 | static LIST_HEAD(all_q_list); | |
40 | ||
320ae51f JA |
41 | /* |
42 | * Check if any of the ctx's have pending work in this hardware queue | |
43 | */ | |
50e1dab8 | 44 | bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx) |
320ae51f | 45 | { |
bd166ef1 JA |
46 | return sbitmap_any_bit_set(&hctx->ctx_map) || |
47 | !list_empty_careful(&hctx->dispatch) || | |
48 | blk_mq_sched_has_work(hctx); | |
1429d7c9 JA |
49 | } |
50 | ||
320ae51f JA |
51 | /* |
52 | * Mark this ctx as having pending work in this hardware queue | |
53 | */ | |
54 | static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx, | |
55 | struct blk_mq_ctx *ctx) | |
56 | { | |
88459642 OS |
57 | if (!sbitmap_test_bit(&hctx->ctx_map, ctx->index_hw)) |
58 | sbitmap_set_bit(&hctx->ctx_map, ctx->index_hw); | |
1429d7c9 JA |
59 | } |
60 | ||
61 | static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx, | |
62 | struct blk_mq_ctx *ctx) | |
63 | { | |
88459642 | 64 | sbitmap_clear_bit(&hctx->ctx_map, ctx->index_hw); |
320ae51f JA |
65 | } |
66 | ||
b4c6a028 | 67 | void blk_mq_freeze_queue_start(struct request_queue *q) |
43a5e4e2 | 68 | { |
4ecd4fef | 69 | int freeze_depth; |
cddd5d17 | 70 | |
4ecd4fef CH |
71 | freeze_depth = atomic_inc_return(&q->mq_freeze_depth); |
72 | if (freeze_depth == 1) { | |
3ef28e83 | 73 | percpu_ref_kill(&q->q_usage_counter); |
b94ec296 | 74 | blk_mq_run_hw_queues(q, false); |
cddd5d17 | 75 | } |
f3af020b | 76 | } |
b4c6a028 | 77 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_start); |
f3af020b TH |
78 | |
79 | static void blk_mq_freeze_queue_wait(struct request_queue *q) | |
80 | { | |
3ef28e83 | 81 | wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter)); |
43a5e4e2 ML |
82 | } |
83 | ||
f3af020b TH |
84 | /* |
85 | * Guarantee no request is in use, so we can change any data structure of | |
86 | * the queue afterward. | |
87 | */ | |
3ef28e83 | 88 | void blk_freeze_queue(struct request_queue *q) |
f3af020b | 89 | { |
3ef28e83 DW |
90 | /* |
91 | * In the !blk_mq case we are only calling this to kill the | |
92 | * q_usage_counter, otherwise this increases the freeze depth | |
93 | * and waits for it to return to zero. For this reason there is | |
94 | * no blk_unfreeze_queue(), and blk_freeze_queue() is not | |
95 | * exported to drivers as the only user for unfreeze is blk_mq. | |
96 | */ | |
f3af020b TH |
97 | blk_mq_freeze_queue_start(q); |
98 | blk_mq_freeze_queue_wait(q); | |
99 | } | |
3ef28e83 DW |
100 | |
101 | void blk_mq_freeze_queue(struct request_queue *q) | |
102 | { | |
103 | /* | |
104 | * ...just an alias to keep freeze and unfreeze actions balanced | |
105 | * in the blk_mq_* namespace | |
106 | */ | |
107 | blk_freeze_queue(q); | |
108 | } | |
c761d96b | 109 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue); |
f3af020b | 110 | |
b4c6a028 | 111 | void blk_mq_unfreeze_queue(struct request_queue *q) |
320ae51f | 112 | { |
4ecd4fef | 113 | int freeze_depth; |
320ae51f | 114 | |
4ecd4fef CH |
115 | freeze_depth = atomic_dec_return(&q->mq_freeze_depth); |
116 | WARN_ON_ONCE(freeze_depth < 0); | |
117 | if (!freeze_depth) { | |
3ef28e83 | 118 | percpu_ref_reinit(&q->q_usage_counter); |
320ae51f | 119 | wake_up_all(&q->mq_freeze_wq); |
add703fd | 120 | } |
320ae51f | 121 | } |
b4c6a028 | 122 | EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue); |
320ae51f | 123 | |
6a83e74d BVA |
124 | /** |
125 | * blk_mq_quiesce_queue() - wait until all ongoing queue_rq calls have finished | |
126 | * @q: request queue. | |
127 | * | |
128 | * Note: this function does not prevent that the struct request end_io() | |
129 | * callback function is invoked. Additionally, it is not prevented that | |
130 | * new queue_rq() calls occur unless the queue has been stopped first. | |
131 | */ | |
132 | void blk_mq_quiesce_queue(struct request_queue *q) | |
133 | { | |
134 | struct blk_mq_hw_ctx *hctx; | |
135 | unsigned int i; | |
136 | bool rcu = false; | |
137 | ||
138 | blk_mq_stop_hw_queues(q); | |
139 | ||
140 | queue_for_each_hw_ctx(q, hctx, i) { | |
141 | if (hctx->flags & BLK_MQ_F_BLOCKING) | |
142 | synchronize_srcu(&hctx->queue_rq_srcu); | |
143 | else | |
144 | rcu = true; | |
145 | } | |
146 | if (rcu) | |
147 | synchronize_rcu(); | |
148 | } | |
149 | EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue); | |
150 | ||
aed3ea94 JA |
151 | void blk_mq_wake_waiters(struct request_queue *q) |
152 | { | |
153 | struct blk_mq_hw_ctx *hctx; | |
154 | unsigned int i; | |
155 | ||
156 | queue_for_each_hw_ctx(q, hctx, i) | |
157 | if (blk_mq_hw_queue_mapped(hctx)) | |
158 | blk_mq_tag_wakeup_all(hctx->tags, true); | |
3fd5940c KB |
159 | |
160 | /* | |
161 | * If we are called because the queue has now been marked as | |
162 | * dying, we need to ensure that processes currently waiting on | |
163 | * the queue are notified as well. | |
164 | */ | |
165 | wake_up_all(&q->mq_freeze_wq); | |
aed3ea94 JA |
166 | } |
167 | ||
320ae51f JA |
168 | bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx) |
169 | { | |
170 | return blk_mq_has_free_tags(hctx->tags); | |
171 | } | |
172 | EXPORT_SYMBOL(blk_mq_can_queue); | |
173 | ||
2c3ad667 JA |
174 | void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, |
175 | struct request *rq, unsigned int op) | |
320ae51f | 176 | { |
af76e555 CH |
177 | INIT_LIST_HEAD(&rq->queuelist); |
178 | /* csd/requeue_work/fifo_time is initialized before use */ | |
179 | rq->q = q; | |
320ae51f | 180 | rq->mq_ctx = ctx; |
ef295ecf | 181 | rq->cmd_flags = op; |
e8064021 CH |
182 | if (blk_queue_io_stat(q)) |
183 | rq->rq_flags |= RQF_IO_STAT; | |
af76e555 CH |
184 | /* do not touch atomic flags, it needs atomic ops against the timer */ |
185 | rq->cpu = -1; | |
af76e555 CH |
186 | INIT_HLIST_NODE(&rq->hash); |
187 | RB_CLEAR_NODE(&rq->rb_node); | |
af76e555 CH |
188 | rq->rq_disk = NULL; |
189 | rq->part = NULL; | |
3ee32372 | 190 | rq->start_time = jiffies; |
af76e555 CH |
191 | #ifdef CONFIG_BLK_CGROUP |
192 | rq->rl = NULL; | |
0fec08b4 | 193 | set_start_time_ns(rq); |
af76e555 CH |
194 | rq->io_start_time_ns = 0; |
195 | #endif | |
196 | rq->nr_phys_segments = 0; | |
197 | #if defined(CONFIG_BLK_DEV_INTEGRITY) | |
198 | rq->nr_integrity_segments = 0; | |
199 | #endif | |
af76e555 CH |
200 | rq->special = NULL; |
201 | /* tag was already set */ | |
202 | rq->errors = 0; | |
af76e555 | 203 | rq->extra_len = 0; |
af76e555 | 204 | |
af76e555 | 205 | INIT_LIST_HEAD(&rq->timeout_list); |
f6be4fb4 JA |
206 | rq->timeout = 0; |
207 | ||
af76e555 CH |
208 | rq->end_io = NULL; |
209 | rq->end_io_data = NULL; | |
210 | rq->next_rq = NULL; | |
211 | ||
ef295ecf | 212 | ctx->rq_dispatched[op_is_sync(op)]++; |
320ae51f | 213 | } |
2c3ad667 | 214 | EXPORT_SYMBOL_GPL(blk_mq_rq_ctx_init); |
320ae51f | 215 | |
2c3ad667 JA |
216 | struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data, |
217 | unsigned int op) | |
5dee8577 CH |
218 | { |
219 | struct request *rq; | |
220 | unsigned int tag; | |
221 | ||
cb96a42c | 222 | tag = blk_mq_get_tag(data); |
5dee8577 | 223 | if (tag != BLK_MQ_TAG_FAIL) { |
bd166ef1 JA |
224 | struct blk_mq_tags *tags = blk_mq_tags_from_data(data); |
225 | ||
226 | rq = tags->static_rqs[tag]; | |
5dee8577 | 227 | |
bd166ef1 JA |
228 | if (data->flags & BLK_MQ_REQ_INTERNAL) { |
229 | rq->tag = -1; | |
230 | rq->internal_tag = tag; | |
231 | } else { | |
200e86b3 JA |
232 | if (blk_mq_tag_busy(data->hctx)) { |
233 | rq->rq_flags = RQF_MQ_INFLIGHT; | |
234 | atomic_inc(&data->hctx->nr_active); | |
235 | } | |
bd166ef1 JA |
236 | rq->tag = tag; |
237 | rq->internal_tag = -1; | |
238 | } | |
239 | ||
ef295ecf | 240 | blk_mq_rq_ctx_init(data->q, data->ctx, rq, op); |
5dee8577 CH |
241 | return rq; |
242 | } | |
243 | ||
244 | return NULL; | |
245 | } | |
2c3ad667 | 246 | EXPORT_SYMBOL_GPL(__blk_mq_alloc_request); |
5dee8577 | 247 | |
6f3b0e8b CH |
248 | struct request *blk_mq_alloc_request(struct request_queue *q, int rw, |
249 | unsigned int flags) | |
320ae51f | 250 | { |
5a797e00 | 251 | struct blk_mq_alloc_data alloc_data = { .flags = flags }; |
bd166ef1 | 252 | struct request *rq; |
a492f075 | 253 | int ret; |
320ae51f | 254 | |
6f3b0e8b | 255 | ret = blk_queue_enter(q, flags & BLK_MQ_REQ_NOWAIT); |
a492f075 JL |
256 | if (ret) |
257 | return ERR_PTR(ret); | |
320ae51f | 258 | |
bd166ef1 | 259 | rq = blk_mq_sched_get_request(q, NULL, rw, &alloc_data); |
841bac2c | 260 | |
bd166ef1 JA |
261 | blk_mq_put_ctx(alloc_data.ctx); |
262 | blk_queue_exit(q); | |
263 | ||
264 | if (!rq) | |
a492f075 | 265 | return ERR_PTR(-EWOULDBLOCK); |
0c4de0f3 CH |
266 | |
267 | rq->__data_len = 0; | |
268 | rq->__sector = (sector_t) -1; | |
269 | rq->bio = rq->biotail = NULL; | |
320ae51f JA |
270 | return rq; |
271 | } | |
4bb659b1 | 272 | EXPORT_SYMBOL(blk_mq_alloc_request); |
320ae51f | 273 | |
1f5bd336 ML |
274 | struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int rw, |
275 | unsigned int flags, unsigned int hctx_idx) | |
276 | { | |
277 | struct blk_mq_hw_ctx *hctx; | |
278 | struct blk_mq_ctx *ctx; | |
279 | struct request *rq; | |
280 | struct blk_mq_alloc_data alloc_data; | |
281 | int ret; | |
282 | ||
283 | /* | |
284 | * If the tag allocator sleeps we could get an allocation for a | |
285 | * different hardware context. No need to complicate the low level | |
286 | * allocator for this for the rare use case of a command tied to | |
287 | * a specific queue. | |
288 | */ | |
289 | if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT))) | |
290 | return ERR_PTR(-EINVAL); | |
291 | ||
292 | if (hctx_idx >= q->nr_hw_queues) | |
293 | return ERR_PTR(-EIO); | |
294 | ||
295 | ret = blk_queue_enter(q, true); | |
296 | if (ret) | |
297 | return ERR_PTR(ret); | |
298 | ||
c8712c6a CH |
299 | /* |
300 | * Check if the hardware context is actually mapped to anything. | |
301 | * If not tell the caller that it should skip this queue. | |
302 | */ | |
1f5bd336 | 303 | hctx = q->queue_hw_ctx[hctx_idx]; |
c8712c6a CH |
304 | if (!blk_mq_hw_queue_mapped(hctx)) { |
305 | ret = -EXDEV; | |
306 | goto out_queue_exit; | |
307 | } | |
1f5bd336 ML |
308 | ctx = __blk_mq_get_ctx(q, cpumask_first(hctx->cpumask)); |
309 | ||
310 | blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx); | |
ef295ecf | 311 | rq = __blk_mq_alloc_request(&alloc_data, rw); |
1f5bd336 | 312 | if (!rq) { |
c8712c6a CH |
313 | ret = -EWOULDBLOCK; |
314 | goto out_queue_exit; | |
1f5bd336 ML |
315 | } |
316 | ||
317 | return rq; | |
c8712c6a CH |
318 | |
319 | out_queue_exit: | |
320 | blk_queue_exit(q); | |
321 | return ERR_PTR(ret); | |
1f5bd336 ML |
322 | } |
323 | EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx); | |
324 | ||
bd166ef1 JA |
325 | void __blk_mq_finish_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, |
326 | struct request *rq) | |
320ae51f | 327 | { |
bd166ef1 | 328 | const int sched_tag = rq->internal_tag; |
320ae51f JA |
329 | struct request_queue *q = rq->q; |
330 | ||
e8064021 | 331 | if (rq->rq_flags & RQF_MQ_INFLIGHT) |
0d2602ca | 332 | atomic_dec(&hctx->nr_active); |
87760e5e JA |
333 | |
334 | wbt_done(q->rq_wb, &rq->issue_stat); | |
e8064021 | 335 | rq->rq_flags = 0; |
0d2602ca | 336 | |
af76e555 | 337 | clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); |
06426adf | 338 | clear_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags); |
bd166ef1 JA |
339 | if (rq->tag != -1) |
340 | blk_mq_put_tag(hctx, hctx->tags, ctx, rq->tag); | |
341 | if (sched_tag != -1) | |
342 | blk_mq_sched_completed_request(hctx, rq); | |
50e1dab8 | 343 | blk_mq_sched_restart_queues(hctx); |
3ef28e83 | 344 | blk_queue_exit(q); |
320ae51f JA |
345 | } |
346 | ||
bd166ef1 | 347 | static void blk_mq_finish_hctx_request(struct blk_mq_hw_ctx *hctx, |
16a3c2a7 | 348 | struct request *rq) |
320ae51f JA |
349 | { |
350 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
320ae51f JA |
351 | |
352 | ctx->rq_completed[rq_is_sync(rq)]++; | |
bd166ef1 JA |
353 | __blk_mq_finish_request(hctx, ctx, rq); |
354 | } | |
355 | ||
356 | void blk_mq_finish_request(struct request *rq) | |
357 | { | |
358 | blk_mq_finish_hctx_request(blk_mq_map_queue(rq->q, rq->mq_ctx->cpu), rq); | |
7c7f2f2b | 359 | } |
7c7f2f2b JA |
360 | |
361 | void blk_mq_free_request(struct request *rq) | |
362 | { | |
bd166ef1 | 363 | blk_mq_sched_put_request(rq); |
320ae51f | 364 | } |
1a3b595a | 365 | EXPORT_SYMBOL_GPL(blk_mq_free_request); |
320ae51f | 366 | |
c8a446ad | 367 | inline void __blk_mq_end_request(struct request *rq, int error) |
320ae51f | 368 | { |
0d11e6ac ML |
369 | blk_account_io_done(rq); |
370 | ||
91b63639 | 371 | if (rq->end_io) { |
87760e5e | 372 | wbt_done(rq->q->rq_wb, &rq->issue_stat); |
320ae51f | 373 | rq->end_io(rq, error); |
91b63639 CH |
374 | } else { |
375 | if (unlikely(blk_bidi_rq(rq))) | |
376 | blk_mq_free_request(rq->next_rq); | |
320ae51f | 377 | blk_mq_free_request(rq); |
91b63639 | 378 | } |
320ae51f | 379 | } |
c8a446ad | 380 | EXPORT_SYMBOL(__blk_mq_end_request); |
63151a44 | 381 | |
c8a446ad | 382 | void blk_mq_end_request(struct request *rq, int error) |
63151a44 CH |
383 | { |
384 | if (blk_update_request(rq, error, blk_rq_bytes(rq))) | |
385 | BUG(); | |
c8a446ad | 386 | __blk_mq_end_request(rq, error); |
63151a44 | 387 | } |
c8a446ad | 388 | EXPORT_SYMBOL(blk_mq_end_request); |
320ae51f | 389 | |
30a91cb4 | 390 | static void __blk_mq_complete_request_remote(void *data) |
320ae51f | 391 | { |
3d6efbf6 | 392 | struct request *rq = data; |
320ae51f | 393 | |
30a91cb4 | 394 | rq->q->softirq_done_fn(rq); |
320ae51f | 395 | } |
320ae51f | 396 | |
ed851860 | 397 | static void blk_mq_ipi_complete_request(struct request *rq) |
320ae51f JA |
398 | { |
399 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
38535201 | 400 | bool shared = false; |
320ae51f JA |
401 | int cpu; |
402 | ||
38535201 | 403 | if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) { |
30a91cb4 CH |
404 | rq->q->softirq_done_fn(rq); |
405 | return; | |
406 | } | |
320ae51f JA |
407 | |
408 | cpu = get_cpu(); | |
38535201 CH |
409 | if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags)) |
410 | shared = cpus_share_cache(cpu, ctx->cpu); | |
411 | ||
412 | if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) { | |
30a91cb4 | 413 | rq->csd.func = __blk_mq_complete_request_remote; |
3d6efbf6 CH |
414 | rq->csd.info = rq; |
415 | rq->csd.flags = 0; | |
c46fff2a | 416 | smp_call_function_single_async(ctx->cpu, &rq->csd); |
3d6efbf6 | 417 | } else { |
30a91cb4 | 418 | rq->q->softirq_done_fn(rq); |
3d6efbf6 | 419 | } |
320ae51f JA |
420 | put_cpu(); |
421 | } | |
30a91cb4 | 422 | |
cf43e6be JA |
423 | static void blk_mq_stat_add(struct request *rq) |
424 | { | |
425 | if (rq->rq_flags & RQF_STATS) { | |
426 | /* | |
427 | * We could rq->mq_ctx here, but there's less of a risk | |
428 | * of races if we have the completion event add the stats | |
429 | * to the local software queue. | |
430 | */ | |
431 | struct blk_mq_ctx *ctx; | |
432 | ||
433 | ctx = __blk_mq_get_ctx(rq->q, raw_smp_processor_id()); | |
434 | blk_stat_add(&ctx->stat[rq_data_dir(rq)], rq); | |
435 | } | |
436 | } | |
437 | ||
1fa8cc52 | 438 | static void __blk_mq_complete_request(struct request *rq) |
ed851860 JA |
439 | { |
440 | struct request_queue *q = rq->q; | |
441 | ||
cf43e6be JA |
442 | blk_mq_stat_add(rq); |
443 | ||
ed851860 | 444 | if (!q->softirq_done_fn) |
c8a446ad | 445 | blk_mq_end_request(rq, rq->errors); |
ed851860 JA |
446 | else |
447 | blk_mq_ipi_complete_request(rq); | |
448 | } | |
449 | ||
30a91cb4 CH |
450 | /** |
451 | * blk_mq_complete_request - end I/O on a request | |
452 | * @rq: the request being processed | |
453 | * | |
454 | * Description: | |
455 | * Ends all I/O on a request. It does not handle partial completions. | |
456 | * The actual completion happens out-of-order, through a IPI handler. | |
457 | **/ | |
f4829a9b | 458 | void blk_mq_complete_request(struct request *rq, int error) |
30a91cb4 | 459 | { |
95f09684 JA |
460 | struct request_queue *q = rq->q; |
461 | ||
462 | if (unlikely(blk_should_fake_timeout(q))) | |
30a91cb4 | 463 | return; |
f4829a9b CH |
464 | if (!blk_mark_rq_complete(rq)) { |
465 | rq->errors = error; | |
ed851860 | 466 | __blk_mq_complete_request(rq); |
f4829a9b | 467 | } |
30a91cb4 CH |
468 | } |
469 | EXPORT_SYMBOL(blk_mq_complete_request); | |
320ae51f | 470 | |
973c0191 KB |
471 | int blk_mq_request_started(struct request *rq) |
472 | { | |
473 | return test_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
474 | } | |
475 | EXPORT_SYMBOL_GPL(blk_mq_request_started); | |
476 | ||
e2490073 | 477 | void blk_mq_start_request(struct request *rq) |
320ae51f JA |
478 | { |
479 | struct request_queue *q = rq->q; | |
480 | ||
bd166ef1 JA |
481 | blk_mq_sched_started_request(rq); |
482 | ||
320ae51f JA |
483 | trace_block_rq_issue(q, rq); |
484 | ||
cf43e6be JA |
485 | if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags)) { |
486 | blk_stat_set_issue_time(&rq->issue_stat); | |
487 | rq->rq_flags |= RQF_STATS; | |
87760e5e | 488 | wbt_issue(q->rq_wb, &rq->issue_stat); |
cf43e6be JA |
489 | } |
490 | ||
2b8393b4 | 491 | blk_add_timer(rq); |
87ee7b11 | 492 | |
538b7534 JA |
493 | /* |
494 | * Ensure that ->deadline is visible before set the started | |
495 | * flag and clear the completed flag. | |
496 | */ | |
497 | smp_mb__before_atomic(); | |
498 | ||
87ee7b11 JA |
499 | /* |
500 | * Mark us as started and clear complete. Complete might have been | |
501 | * set if requeue raced with timeout, which then marked it as | |
502 | * complete. So be sure to clear complete again when we start | |
503 | * the request, otherwise we'll ignore the completion event. | |
504 | */ | |
4b570521 JA |
505 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) |
506 | set_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
507 | if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) | |
508 | clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); | |
49f5baa5 CH |
509 | |
510 | if (q->dma_drain_size && blk_rq_bytes(rq)) { | |
511 | /* | |
512 | * Make sure space for the drain appears. We know we can do | |
513 | * this because max_hw_segments has been adjusted to be one | |
514 | * fewer than the device can handle. | |
515 | */ | |
516 | rq->nr_phys_segments++; | |
517 | } | |
320ae51f | 518 | } |
e2490073 | 519 | EXPORT_SYMBOL(blk_mq_start_request); |
320ae51f | 520 | |
ed0791b2 | 521 | static void __blk_mq_requeue_request(struct request *rq) |
320ae51f JA |
522 | { |
523 | struct request_queue *q = rq->q; | |
524 | ||
525 | trace_block_rq_requeue(q, rq); | |
87760e5e | 526 | wbt_requeue(q->rq_wb, &rq->issue_stat); |
bd166ef1 | 527 | blk_mq_sched_requeue_request(rq); |
49f5baa5 | 528 | |
e2490073 CH |
529 | if (test_and_clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) { |
530 | if (q->dma_drain_size && blk_rq_bytes(rq)) | |
531 | rq->nr_phys_segments--; | |
532 | } | |
320ae51f JA |
533 | } |
534 | ||
2b053aca | 535 | void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list) |
ed0791b2 | 536 | { |
ed0791b2 | 537 | __blk_mq_requeue_request(rq); |
ed0791b2 | 538 | |
ed0791b2 | 539 | BUG_ON(blk_queued_rq(rq)); |
2b053aca | 540 | blk_mq_add_to_requeue_list(rq, true, kick_requeue_list); |
ed0791b2 CH |
541 | } |
542 | EXPORT_SYMBOL(blk_mq_requeue_request); | |
543 | ||
6fca6a61 CH |
544 | static void blk_mq_requeue_work(struct work_struct *work) |
545 | { | |
546 | struct request_queue *q = | |
2849450a | 547 | container_of(work, struct request_queue, requeue_work.work); |
6fca6a61 CH |
548 | LIST_HEAD(rq_list); |
549 | struct request *rq, *next; | |
550 | unsigned long flags; | |
551 | ||
552 | spin_lock_irqsave(&q->requeue_lock, flags); | |
553 | list_splice_init(&q->requeue_list, &rq_list); | |
554 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
555 | ||
556 | list_for_each_entry_safe(rq, next, &rq_list, queuelist) { | |
e8064021 | 557 | if (!(rq->rq_flags & RQF_SOFTBARRIER)) |
6fca6a61 CH |
558 | continue; |
559 | ||
e8064021 | 560 | rq->rq_flags &= ~RQF_SOFTBARRIER; |
6fca6a61 | 561 | list_del_init(&rq->queuelist); |
bd6737f1 | 562 | blk_mq_sched_insert_request(rq, true, false, false, true); |
6fca6a61 CH |
563 | } |
564 | ||
565 | while (!list_empty(&rq_list)) { | |
566 | rq = list_entry(rq_list.next, struct request, queuelist); | |
567 | list_del_init(&rq->queuelist); | |
bd6737f1 | 568 | blk_mq_sched_insert_request(rq, false, false, false, true); |
6fca6a61 CH |
569 | } |
570 | ||
52d7f1b5 | 571 | blk_mq_run_hw_queues(q, false); |
6fca6a61 CH |
572 | } |
573 | ||
2b053aca BVA |
574 | void blk_mq_add_to_requeue_list(struct request *rq, bool at_head, |
575 | bool kick_requeue_list) | |
6fca6a61 CH |
576 | { |
577 | struct request_queue *q = rq->q; | |
578 | unsigned long flags; | |
579 | ||
580 | /* | |
581 | * We abuse this flag that is otherwise used by the I/O scheduler to | |
582 | * request head insertation from the workqueue. | |
583 | */ | |
e8064021 | 584 | BUG_ON(rq->rq_flags & RQF_SOFTBARRIER); |
6fca6a61 CH |
585 | |
586 | spin_lock_irqsave(&q->requeue_lock, flags); | |
587 | if (at_head) { | |
e8064021 | 588 | rq->rq_flags |= RQF_SOFTBARRIER; |
6fca6a61 CH |
589 | list_add(&rq->queuelist, &q->requeue_list); |
590 | } else { | |
591 | list_add_tail(&rq->queuelist, &q->requeue_list); | |
592 | } | |
593 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
2b053aca BVA |
594 | |
595 | if (kick_requeue_list) | |
596 | blk_mq_kick_requeue_list(q); | |
6fca6a61 CH |
597 | } |
598 | EXPORT_SYMBOL(blk_mq_add_to_requeue_list); | |
599 | ||
600 | void blk_mq_kick_requeue_list(struct request_queue *q) | |
601 | { | |
2849450a | 602 | kblockd_schedule_delayed_work(&q->requeue_work, 0); |
6fca6a61 CH |
603 | } |
604 | EXPORT_SYMBOL(blk_mq_kick_requeue_list); | |
605 | ||
2849450a MS |
606 | void blk_mq_delay_kick_requeue_list(struct request_queue *q, |
607 | unsigned long msecs) | |
608 | { | |
609 | kblockd_schedule_delayed_work(&q->requeue_work, | |
610 | msecs_to_jiffies(msecs)); | |
611 | } | |
612 | EXPORT_SYMBOL(blk_mq_delay_kick_requeue_list); | |
613 | ||
1885b24d JA |
614 | void blk_mq_abort_requeue_list(struct request_queue *q) |
615 | { | |
616 | unsigned long flags; | |
617 | LIST_HEAD(rq_list); | |
618 | ||
619 | spin_lock_irqsave(&q->requeue_lock, flags); | |
620 | list_splice_init(&q->requeue_list, &rq_list); | |
621 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
622 | ||
623 | while (!list_empty(&rq_list)) { | |
624 | struct request *rq; | |
625 | ||
626 | rq = list_first_entry(&rq_list, struct request, queuelist); | |
627 | list_del_init(&rq->queuelist); | |
628 | rq->errors = -EIO; | |
629 | blk_mq_end_request(rq, rq->errors); | |
630 | } | |
631 | } | |
632 | EXPORT_SYMBOL(blk_mq_abort_requeue_list); | |
633 | ||
0e62f51f JA |
634 | struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag) |
635 | { | |
88c7b2b7 JA |
636 | if (tag < tags->nr_tags) { |
637 | prefetch(tags->rqs[tag]); | |
4ee86bab | 638 | return tags->rqs[tag]; |
88c7b2b7 | 639 | } |
4ee86bab HR |
640 | |
641 | return NULL; | |
24d2f903 CH |
642 | } |
643 | EXPORT_SYMBOL(blk_mq_tag_to_rq); | |
644 | ||
320ae51f | 645 | struct blk_mq_timeout_data { |
46f92d42 CH |
646 | unsigned long next; |
647 | unsigned int next_set; | |
320ae51f JA |
648 | }; |
649 | ||
90415837 | 650 | void blk_mq_rq_timed_out(struct request *req, bool reserved) |
320ae51f | 651 | { |
f8a5b122 | 652 | const struct blk_mq_ops *ops = req->q->mq_ops; |
46f92d42 | 653 | enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER; |
87ee7b11 JA |
654 | |
655 | /* | |
656 | * We know that complete is set at this point. If STARTED isn't set | |
657 | * anymore, then the request isn't active and the "timeout" should | |
658 | * just be ignored. This can happen due to the bitflag ordering. | |
659 | * Timeout first checks if STARTED is set, and if it is, assumes | |
660 | * the request is active. But if we race with completion, then | |
661 | * we both flags will get cleared. So check here again, and ignore | |
662 | * a timeout event with a request that isn't active. | |
663 | */ | |
46f92d42 CH |
664 | if (!test_bit(REQ_ATOM_STARTED, &req->atomic_flags)) |
665 | return; | |
87ee7b11 | 666 | |
46f92d42 | 667 | if (ops->timeout) |
0152fb6b | 668 | ret = ops->timeout(req, reserved); |
46f92d42 CH |
669 | |
670 | switch (ret) { | |
671 | case BLK_EH_HANDLED: | |
672 | __blk_mq_complete_request(req); | |
673 | break; | |
674 | case BLK_EH_RESET_TIMER: | |
675 | blk_add_timer(req); | |
676 | blk_clear_rq_complete(req); | |
677 | break; | |
678 | case BLK_EH_NOT_HANDLED: | |
679 | break; | |
680 | default: | |
681 | printk(KERN_ERR "block: bad eh return: %d\n", ret); | |
682 | break; | |
683 | } | |
87ee7b11 | 684 | } |
5b3f25fc | 685 | |
81481eb4 CH |
686 | static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx, |
687 | struct request *rq, void *priv, bool reserved) | |
688 | { | |
689 | struct blk_mq_timeout_data *data = priv; | |
87ee7b11 | 690 | |
eb130dbf KB |
691 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) { |
692 | /* | |
693 | * If a request wasn't started before the queue was | |
694 | * marked dying, kill it here or it'll go unnoticed. | |
695 | */ | |
a59e0f57 KB |
696 | if (unlikely(blk_queue_dying(rq->q))) { |
697 | rq->errors = -EIO; | |
698 | blk_mq_end_request(rq, rq->errors); | |
699 | } | |
46f92d42 | 700 | return; |
eb130dbf | 701 | } |
87ee7b11 | 702 | |
46f92d42 CH |
703 | if (time_after_eq(jiffies, rq->deadline)) { |
704 | if (!blk_mark_rq_complete(rq)) | |
0152fb6b | 705 | blk_mq_rq_timed_out(rq, reserved); |
46f92d42 CH |
706 | } else if (!data->next_set || time_after(data->next, rq->deadline)) { |
707 | data->next = rq->deadline; | |
708 | data->next_set = 1; | |
709 | } | |
87ee7b11 JA |
710 | } |
711 | ||
287922eb | 712 | static void blk_mq_timeout_work(struct work_struct *work) |
320ae51f | 713 | { |
287922eb CH |
714 | struct request_queue *q = |
715 | container_of(work, struct request_queue, timeout_work); | |
81481eb4 CH |
716 | struct blk_mq_timeout_data data = { |
717 | .next = 0, | |
718 | .next_set = 0, | |
719 | }; | |
81481eb4 | 720 | int i; |
320ae51f | 721 | |
71f79fb3 GKB |
722 | /* A deadlock might occur if a request is stuck requiring a |
723 | * timeout at the same time a queue freeze is waiting | |
724 | * completion, since the timeout code would not be able to | |
725 | * acquire the queue reference here. | |
726 | * | |
727 | * That's why we don't use blk_queue_enter here; instead, we use | |
728 | * percpu_ref_tryget directly, because we need to be able to | |
729 | * obtain a reference even in the short window between the queue | |
730 | * starting to freeze, by dropping the first reference in | |
731 | * blk_mq_freeze_queue_start, and the moment the last request is | |
732 | * consumed, marked by the instant q_usage_counter reaches | |
733 | * zero. | |
734 | */ | |
735 | if (!percpu_ref_tryget(&q->q_usage_counter)) | |
287922eb CH |
736 | return; |
737 | ||
0bf6cd5b | 738 | blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &data); |
320ae51f | 739 | |
81481eb4 CH |
740 | if (data.next_set) { |
741 | data.next = blk_rq_timeout(round_jiffies_up(data.next)); | |
742 | mod_timer(&q->timeout, data.next); | |
0d2602ca | 743 | } else { |
0bf6cd5b CH |
744 | struct blk_mq_hw_ctx *hctx; |
745 | ||
f054b56c ML |
746 | queue_for_each_hw_ctx(q, hctx, i) { |
747 | /* the hctx may be unmapped, so check it here */ | |
748 | if (blk_mq_hw_queue_mapped(hctx)) | |
749 | blk_mq_tag_idle(hctx); | |
750 | } | |
0d2602ca | 751 | } |
287922eb | 752 | blk_queue_exit(q); |
320ae51f JA |
753 | } |
754 | ||
755 | /* | |
756 | * Reverse check our software queue for entries that we could potentially | |
757 | * merge with. Currently includes a hand-wavy stop count of 8, to not spend | |
758 | * too much time checking for merges. | |
759 | */ | |
760 | static bool blk_mq_attempt_merge(struct request_queue *q, | |
761 | struct blk_mq_ctx *ctx, struct bio *bio) | |
762 | { | |
763 | struct request *rq; | |
764 | int checked = 8; | |
765 | ||
766 | list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) { | |
34fe7c05 | 767 | bool merged = false; |
320ae51f JA |
768 | |
769 | if (!checked--) | |
770 | break; | |
771 | ||
772 | if (!blk_rq_merge_ok(rq, bio)) | |
773 | continue; | |
774 | ||
34fe7c05 CH |
775 | switch (blk_try_merge(rq, bio)) { |
776 | case ELEVATOR_BACK_MERGE: | |
777 | if (blk_mq_sched_allow_merge(q, rq, bio)) | |
778 | merged = bio_attempt_back_merge(q, rq, bio); | |
bd166ef1 | 779 | break; |
34fe7c05 CH |
780 | case ELEVATOR_FRONT_MERGE: |
781 | if (blk_mq_sched_allow_merge(q, rq, bio)) | |
782 | merged = bio_attempt_front_merge(q, rq, bio); | |
320ae51f | 783 | break; |
1e739730 CH |
784 | case ELEVATOR_DISCARD_MERGE: |
785 | merged = bio_attempt_discard_merge(q, rq, bio); | |
320ae51f | 786 | break; |
34fe7c05 CH |
787 | default: |
788 | continue; | |
320ae51f | 789 | } |
34fe7c05 CH |
790 | |
791 | if (merged) | |
792 | ctx->rq_merged++; | |
793 | return merged; | |
320ae51f JA |
794 | } |
795 | ||
796 | return false; | |
797 | } | |
798 | ||
88459642 OS |
799 | struct flush_busy_ctx_data { |
800 | struct blk_mq_hw_ctx *hctx; | |
801 | struct list_head *list; | |
802 | }; | |
803 | ||
804 | static bool flush_busy_ctx(struct sbitmap *sb, unsigned int bitnr, void *data) | |
805 | { | |
806 | struct flush_busy_ctx_data *flush_data = data; | |
807 | struct blk_mq_hw_ctx *hctx = flush_data->hctx; | |
808 | struct blk_mq_ctx *ctx = hctx->ctxs[bitnr]; | |
809 | ||
810 | sbitmap_clear_bit(sb, bitnr); | |
811 | spin_lock(&ctx->lock); | |
812 | list_splice_tail_init(&ctx->rq_list, flush_data->list); | |
813 | spin_unlock(&ctx->lock); | |
814 | return true; | |
815 | } | |
816 | ||
1429d7c9 JA |
817 | /* |
818 | * Process software queues that have been marked busy, splicing them | |
819 | * to the for-dispatch | |
820 | */ | |
2c3ad667 | 821 | void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) |
1429d7c9 | 822 | { |
88459642 OS |
823 | struct flush_busy_ctx_data data = { |
824 | .hctx = hctx, | |
825 | .list = list, | |
826 | }; | |
1429d7c9 | 827 | |
88459642 | 828 | sbitmap_for_each_set(&hctx->ctx_map, flush_busy_ctx, &data); |
1429d7c9 | 829 | } |
2c3ad667 | 830 | EXPORT_SYMBOL_GPL(blk_mq_flush_busy_ctxs); |
1429d7c9 | 831 | |
703fd1c0 JA |
832 | static inline unsigned int queued_to_index(unsigned int queued) |
833 | { | |
834 | if (!queued) | |
835 | return 0; | |
1429d7c9 | 836 | |
703fd1c0 | 837 | return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1); |
1429d7c9 JA |
838 | } |
839 | ||
bd6737f1 JA |
840 | bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx, |
841 | bool wait) | |
bd166ef1 JA |
842 | { |
843 | struct blk_mq_alloc_data data = { | |
844 | .q = rq->q, | |
bd166ef1 JA |
845 | .hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu), |
846 | .flags = wait ? 0 : BLK_MQ_REQ_NOWAIT, | |
847 | }; | |
848 | ||
bd166ef1 JA |
849 | if (rq->tag != -1) { |
850 | done: | |
851 | if (hctx) | |
852 | *hctx = data.hctx; | |
853 | return true; | |
854 | } | |
855 | ||
856 | rq->tag = blk_mq_get_tag(&data); | |
857 | if (rq->tag >= 0) { | |
200e86b3 JA |
858 | if (blk_mq_tag_busy(data.hctx)) { |
859 | rq->rq_flags |= RQF_MQ_INFLIGHT; | |
860 | atomic_inc(&data.hctx->nr_active); | |
861 | } | |
bd166ef1 JA |
862 | data.hctx->tags->rqs[rq->tag] = rq; |
863 | goto done; | |
864 | } | |
865 | ||
866 | return false; | |
867 | } | |
868 | ||
99cf1dc5 JA |
869 | static void blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx, |
870 | struct request *rq) | |
871 | { | |
872 | if (rq->tag == -1 || rq->internal_tag == -1) | |
873 | return; | |
874 | ||
875 | blk_mq_put_tag(hctx, hctx->tags, rq->mq_ctx, rq->tag); | |
876 | rq->tag = -1; | |
877 | ||
878 | if (rq->rq_flags & RQF_MQ_INFLIGHT) { | |
879 | rq->rq_flags &= ~RQF_MQ_INFLIGHT; | |
880 | atomic_dec(&hctx->nr_active); | |
881 | } | |
882 | } | |
883 | ||
bd166ef1 JA |
884 | /* |
885 | * If we fail getting a driver tag because all the driver tags are already | |
886 | * assigned and on the dispatch list, BUT the first entry does not have a | |
887 | * tag, then we could deadlock. For that case, move entries with assigned | |
888 | * driver tags to the front, leaving the set of tagged requests in the | |
889 | * same order, and the untagged set in the same order. | |
890 | */ | |
891 | static bool reorder_tags_to_front(struct list_head *list) | |
892 | { | |
893 | struct request *rq, *tmp, *first = NULL; | |
894 | ||
895 | list_for_each_entry_safe_reverse(rq, tmp, list, queuelist) { | |
896 | if (rq == first) | |
897 | break; | |
898 | if (rq->tag != -1) { | |
899 | list_move(&rq->queuelist, list); | |
900 | if (!first) | |
901 | first = rq; | |
902 | } | |
903 | } | |
904 | ||
905 | return first != NULL; | |
906 | } | |
907 | ||
da55f2cc OS |
908 | static int blk_mq_dispatch_wake(wait_queue_t *wait, unsigned mode, int flags, |
909 | void *key) | |
910 | { | |
911 | struct blk_mq_hw_ctx *hctx; | |
912 | ||
913 | hctx = container_of(wait, struct blk_mq_hw_ctx, dispatch_wait); | |
914 | ||
915 | list_del(&wait->task_list); | |
916 | clear_bit_unlock(BLK_MQ_S_TAG_WAITING, &hctx->state); | |
917 | blk_mq_run_hw_queue(hctx, true); | |
918 | return 1; | |
919 | } | |
920 | ||
921 | static bool blk_mq_dispatch_wait_add(struct blk_mq_hw_ctx *hctx) | |
922 | { | |
923 | struct sbq_wait_state *ws; | |
924 | ||
925 | /* | |
926 | * The TAG_WAITING bit serves as a lock protecting hctx->dispatch_wait. | |
927 | * The thread which wins the race to grab this bit adds the hardware | |
928 | * queue to the wait queue. | |
929 | */ | |
930 | if (test_bit(BLK_MQ_S_TAG_WAITING, &hctx->state) || | |
931 | test_and_set_bit_lock(BLK_MQ_S_TAG_WAITING, &hctx->state)) | |
932 | return false; | |
933 | ||
934 | init_waitqueue_func_entry(&hctx->dispatch_wait, blk_mq_dispatch_wake); | |
935 | ws = bt_wait_ptr(&hctx->tags->bitmap_tags, hctx); | |
936 | ||
937 | /* | |
938 | * As soon as this returns, it's no longer safe to fiddle with | |
939 | * hctx->dispatch_wait, since a completion can wake up the wait queue | |
940 | * and unlock the bit. | |
941 | */ | |
942 | add_wait_queue(&ws->wait, &hctx->dispatch_wait); | |
943 | return true; | |
944 | } | |
945 | ||
f04c3df3 | 946 | bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list) |
320ae51f JA |
947 | { |
948 | struct request_queue *q = hctx->queue; | |
320ae51f | 949 | struct request *rq; |
74c45052 JA |
950 | LIST_HEAD(driver_list); |
951 | struct list_head *dptr; | |
f04c3df3 | 952 | int queued, ret = BLK_MQ_RQ_QUEUE_OK; |
320ae51f | 953 | |
74c45052 JA |
954 | /* |
955 | * Start off with dptr being NULL, so we start the first request | |
956 | * immediately, even if we have more pending. | |
957 | */ | |
958 | dptr = NULL; | |
959 | ||
320ae51f JA |
960 | /* |
961 | * Now process all the entries, sending them to the driver. | |
962 | */ | |
1429d7c9 | 963 | queued = 0; |
f04c3df3 | 964 | while (!list_empty(list)) { |
74c45052 | 965 | struct blk_mq_queue_data bd; |
320ae51f | 966 | |
f04c3df3 | 967 | rq = list_first_entry(list, struct request, queuelist); |
bd166ef1 JA |
968 | if (!blk_mq_get_driver_tag(rq, &hctx, false)) { |
969 | if (!queued && reorder_tags_to_front(list)) | |
970 | continue; | |
3c782d67 JA |
971 | |
972 | /* | |
da55f2cc OS |
973 | * The initial allocation attempt failed, so we need to |
974 | * rerun the hardware queue when a tag is freed. | |
3c782d67 | 975 | */ |
da55f2cc OS |
976 | if (blk_mq_dispatch_wait_add(hctx)) { |
977 | /* | |
978 | * It's possible that a tag was freed in the | |
979 | * window between the allocation failure and | |
980 | * adding the hardware queue to the wait queue. | |
981 | */ | |
982 | if (!blk_mq_get_driver_tag(rq, &hctx, false)) | |
983 | break; | |
984 | } else { | |
3c782d67 | 985 | break; |
da55f2cc | 986 | } |
bd166ef1 | 987 | } |
da55f2cc | 988 | |
320ae51f | 989 | list_del_init(&rq->queuelist); |
320ae51f | 990 | |
74c45052 JA |
991 | bd.rq = rq; |
992 | bd.list = dptr; | |
f04c3df3 | 993 | bd.last = list_empty(list); |
74c45052 JA |
994 | |
995 | ret = q->mq_ops->queue_rq(hctx, &bd); | |
320ae51f JA |
996 | switch (ret) { |
997 | case BLK_MQ_RQ_QUEUE_OK: | |
998 | queued++; | |
52b9c330 | 999 | break; |
320ae51f | 1000 | case BLK_MQ_RQ_QUEUE_BUSY: |
99cf1dc5 | 1001 | blk_mq_put_driver_tag(hctx, rq); |
f04c3df3 | 1002 | list_add(&rq->queuelist, list); |
ed0791b2 | 1003 | __blk_mq_requeue_request(rq); |
320ae51f JA |
1004 | break; |
1005 | default: | |
1006 | pr_err("blk-mq: bad return on queue: %d\n", ret); | |
320ae51f | 1007 | case BLK_MQ_RQ_QUEUE_ERROR: |
1e93b8c2 | 1008 | rq->errors = -EIO; |
c8a446ad | 1009 | blk_mq_end_request(rq, rq->errors); |
320ae51f JA |
1010 | break; |
1011 | } | |
1012 | ||
1013 | if (ret == BLK_MQ_RQ_QUEUE_BUSY) | |
1014 | break; | |
74c45052 JA |
1015 | |
1016 | /* | |
1017 | * We've done the first request. If we have more than 1 | |
1018 | * left in the list, set dptr to defer issue. | |
1019 | */ | |
f04c3df3 | 1020 | if (!dptr && list->next != list->prev) |
74c45052 | 1021 | dptr = &driver_list; |
320ae51f JA |
1022 | } |
1023 | ||
703fd1c0 | 1024 | hctx->dispatched[queued_to_index(queued)]++; |
320ae51f JA |
1025 | |
1026 | /* | |
1027 | * Any items that need requeuing? Stuff them into hctx->dispatch, | |
1028 | * that is where we will continue on next queue run. | |
1029 | */ | |
f04c3df3 | 1030 | if (!list_empty(list)) { |
320ae51f | 1031 | spin_lock(&hctx->lock); |
c13660a0 | 1032 | list_splice_init(list, &hctx->dispatch); |
320ae51f | 1033 | spin_unlock(&hctx->lock); |
f04c3df3 | 1034 | |
9ba52e58 SL |
1035 | /* |
1036 | * the queue is expected stopped with BLK_MQ_RQ_QUEUE_BUSY, but | |
1037 | * it's possible the queue is stopped and restarted again | |
1038 | * before this. Queue restart will dispatch requests. And since | |
1039 | * requests in rq_list aren't added into hctx->dispatch yet, | |
1040 | * the requests in rq_list might get lost. | |
1041 | * | |
1042 | * blk_mq_run_hw_queue() already checks the STOPPED bit | |
bd166ef1 | 1043 | * |
da55f2cc OS |
1044 | * If RESTART or TAG_WAITING is set, then let completion restart |
1045 | * the queue instead of potentially looping here. | |
bd166ef1 | 1046 | */ |
da55f2cc OS |
1047 | if (!blk_mq_sched_needs_restart(hctx) && |
1048 | !test_bit(BLK_MQ_S_TAG_WAITING, &hctx->state)) | |
bd166ef1 | 1049 | blk_mq_run_hw_queue(hctx, true); |
320ae51f | 1050 | } |
f04c3df3 | 1051 | |
2aa0f21d | 1052 | return queued != 0; |
f04c3df3 JA |
1053 | } |
1054 | ||
6a83e74d BVA |
1055 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) |
1056 | { | |
1057 | int srcu_idx; | |
1058 | ||
1059 | WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) && | |
1060 | cpu_online(hctx->next_cpu)); | |
1061 | ||
1062 | if (!(hctx->flags & BLK_MQ_F_BLOCKING)) { | |
1063 | rcu_read_lock(); | |
bd166ef1 | 1064 | blk_mq_sched_dispatch_requests(hctx); |
6a83e74d BVA |
1065 | rcu_read_unlock(); |
1066 | } else { | |
1067 | srcu_idx = srcu_read_lock(&hctx->queue_rq_srcu); | |
bd166ef1 | 1068 | blk_mq_sched_dispatch_requests(hctx); |
6a83e74d BVA |
1069 | srcu_read_unlock(&hctx->queue_rq_srcu, srcu_idx); |
1070 | } | |
1071 | } | |
1072 | ||
506e931f JA |
1073 | /* |
1074 | * It'd be great if the workqueue API had a way to pass | |
1075 | * in a mask and had some smarts for more clever placement. | |
1076 | * For now we just round-robin here, switching for every | |
1077 | * BLK_MQ_CPU_WORK_BATCH queued items. | |
1078 | */ | |
1079 | static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) | |
1080 | { | |
b657d7e6 CH |
1081 | if (hctx->queue->nr_hw_queues == 1) |
1082 | return WORK_CPU_UNBOUND; | |
506e931f JA |
1083 | |
1084 | if (--hctx->next_cpu_batch <= 0) { | |
c02ebfdd | 1085 | int next_cpu; |
506e931f JA |
1086 | |
1087 | next_cpu = cpumask_next(hctx->next_cpu, hctx->cpumask); | |
1088 | if (next_cpu >= nr_cpu_ids) | |
1089 | next_cpu = cpumask_first(hctx->cpumask); | |
1090 | ||
1091 | hctx->next_cpu = next_cpu; | |
1092 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
1093 | } | |
1094 | ||
b657d7e6 | 1095 | return hctx->next_cpu; |
506e931f JA |
1096 | } |
1097 | ||
320ae51f JA |
1098 | void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
1099 | { | |
5d1b25c1 BVA |
1100 | if (unlikely(blk_mq_hctx_stopped(hctx) || |
1101 | !blk_mq_hw_queue_mapped(hctx))) | |
320ae51f JA |
1102 | return; |
1103 | ||
1b792f2f | 1104 | if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) { |
2a90d4aa PB |
1105 | int cpu = get_cpu(); |
1106 | if (cpumask_test_cpu(cpu, hctx->cpumask)) { | |
398205b8 | 1107 | __blk_mq_run_hw_queue(hctx); |
2a90d4aa | 1108 | put_cpu(); |
398205b8 PB |
1109 | return; |
1110 | } | |
e4043dcf | 1111 | |
2a90d4aa | 1112 | put_cpu(); |
e4043dcf | 1113 | } |
398205b8 | 1114 | |
27489a3c | 1115 | kblockd_schedule_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work); |
320ae51f JA |
1116 | } |
1117 | ||
b94ec296 | 1118 | void blk_mq_run_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
1119 | { |
1120 | struct blk_mq_hw_ctx *hctx; | |
1121 | int i; | |
1122 | ||
1123 | queue_for_each_hw_ctx(q, hctx, i) { | |
bd166ef1 | 1124 | if (!blk_mq_hctx_has_pending(hctx) || |
5d1b25c1 | 1125 | blk_mq_hctx_stopped(hctx)) |
320ae51f JA |
1126 | continue; |
1127 | ||
b94ec296 | 1128 | blk_mq_run_hw_queue(hctx, async); |
320ae51f JA |
1129 | } |
1130 | } | |
b94ec296 | 1131 | EXPORT_SYMBOL(blk_mq_run_hw_queues); |
320ae51f | 1132 | |
fd001443 BVA |
1133 | /** |
1134 | * blk_mq_queue_stopped() - check whether one or more hctxs have been stopped | |
1135 | * @q: request queue. | |
1136 | * | |
1137 | * The caller is responsible for serializing this function against | |
1138 | * blk_mq_{start,stop}_hw_queue(). | |
1139 | */ | |
1140 | bool blk_mq_queue_stopped(struct request_queue *q) | |
1141 | { | |
1142 | struct blk_mq_hw_ctx *hctx; | |
1143 | int i; | |
1144 | ||
1145 | queue_for_each_hw_ctx(q, hctx, i) | |
1146 | if (blk_mq_hctx_stopped(hctx)) | |
1147 | return true; | |
1148 | ||
1149 | return false; | |
1150 | } | |
1151 | EXPORT_SYMBOL(blk_mq_queue_stopped); | |
1152 | ||
320ae51f JA |
1153 | void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx) |
1154 | { | |
27489a3c | 1155 | cancel_work(&hctx->run_work); |
70f4db63 | 1156 | cancel_delayed_work(&hctx->delay_work); |
320ae51f JA |
1157 | set_bit(BLK_MQ_S_STOPPED, &hctx->state); |
1158 | } | |
1159 | EXPORT_SYMBOL(blk_mq_stop_hw_queue); | |
1160 | ||
280d45f6 CH |
1161 | void blk_mq_stop_hw_queues(struct request_queue *q) |
1162 | { | |
1163 | struct blk_mq_hw_ctx *hctx; | |
1164 | int i; | |
1165 | ||
1166 | queue_for_each_hw_ctx(q, hctx, i) | |
1167 | blk_mq_stop_hw_queue(hctx); | |
1168 | } | |
1169 | EXPORT_SYMBOL(blk_mq_stop_hw_queues); | |
1170 | ||
320ae51f JA |
1171 | void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx) |
1172 | { | |
1173 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
e4043dcf | 1174 | |
0ffbce80 | 1175 | blk_mq_run_hw_queue(hctx, false); |
320ae51f JA |
1176 | } |
1177 | EXPORT_SYMBOL(blk_mq_start_hw_queue); | |
1178 | ||
2f268556 CH |
1179 | void blk_mq_start_hw_queues(struct request_queue *q) |
1180 | { | |
1181 | struct blk_mq_hw_ctx *hctx; | |
1182 | int i; | |
1183 | ||
1184 | queue_for_each_hw_ctx(q, hctx, i) | |
1185 | blk_mq_start_hw_queue(hctx); | |
1186 | } | |
1187 | EXPORT_SYMBOL(blk_mq_start_hw_queues); | |
1188 | ||
ae911c5e JA |
1189 | void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
1190 | { | |
1191 | if (!blk_mq_hctx_stopped(hctx)) | |
1192 | return; | |
1193 | ||
1194 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
1195 | blk_mq_run_hw_queue(hctx, async); | |
1196 | } | |
1197 | EXPORT_SYMBOL_GPL(blk_mq_start_stopped_hw_queue); | |
1198 | ||
1b4a3258 | 1199 | void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
1200 | { |
1201 | struct blk_mq_hw_ctx *hctx; | |
1202 | int i; | |
1203 | ||
ae911c5e JA |
1204 | queue_for_each_hw_ctx(q, hctx, i) |
1205 | blk_mq_start_stopped_hw_queue(hctx, async); | |
320ae51f JA |
1206 | } |
1207 | EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); | |
1208 | ||
70f4db63 | 1209 | static void blk_mq_run_work_fn(struct work_struct *work) |
320ae51f JA |
1210 | { |
1211 | struct blk_mq_hw_ctx *hctx; | |
1212 | ||
27489a3c | 1213 | hctx = container_of(work, struct blk_mq_hw_ctx, run_work); |
e4043dcf | 1214 | |
320ae51f JA |
1215 | __blk_mq_run_hw_queue(hctx); |
1216 | } | |
1217 | ||
70f4db63 CH |
1218 | static void blk_mq_delay_work_fn(struct work_struct *work) |
1219 | { | |
1220 | struct blk_mq_hw_ctx *hctx; | |
1221 | ||
1222 | hctx = container_of(work, struct blk_mq_hw_ctx, delay_work.work); | |
1223 | ||
1224 | if (test_and_clear_bit(BLK_MQ_S_STOPPED, &hctx->state)) | |
1225 | __blk_mq_run_hw_queue(hctx); | |
1226 | } | |
1227 | ||
1228 | void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) | |
1229 | { | |
19c66e59 ML |
1230 | if (unlikely(!blk_mq_hw_queue_mapped(hctx))) |
1231 | return; | |
70f4db63 | 1232 | |
7e79dadc | 1233 | blk_mq_stop_hw_queue(hctx); |
b657d7e6 CH |
1234 | kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx), |
1235 | &hctx->delay_work, msecs_to_jiffies(msecs)); | |
70f4db63 CH |
1236 | } |
1237 | EXPORT_SYMBOL(blk_mq_delay_queue); | |
1238 | ||
cfd0c552 | 1239 | static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx, |
cfd0c552 ML |
1240 | struct request *rq, |
1241 | bool at_head) | |
320ae51f | 1242 | { |
e57690fe JA |
1243 | struct blk_mq_ctx *ctx = rq->mq_ctx; |
1244 | ||
01b983c9 JA |
1245 | trace_block_rq_insert(hctx->queue, rq); |
1246 | ||
72a0a36e CH |
1247 | if (at_head) |
1248 | list_add(&rq->queuelist, &ctx->rq_list); | |
1249 | else | |
1250 | list_add_tail(&rq->queuelist, &ctx->rq_list); | |
cfd0c552 | 1251 | } |
4bb659b1 | 1252 | |
2c3ad667 JA |
1253 | void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, |
1254 | bool at_head) | |
cfd0c552 ML |
1255 | { |
1256 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
1257 | ||
e57690fe | 1258 | __blk_mq_insert_req_list(hctx, rq, at_head); |
320ae51f | 1259 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f JA |
1260 | } |
1261 | ||
bd166ef1 JA |
1262 | void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, |
1263 | struct list_head *list) | |
320ae51f JA |
1264 | |
1265 | { | |
320ae51f JA |
1266 | /* |
1267 | * preemption doesn't flush plug list, so it's possible ctx->cpu is | |
1268 | * offline now | |
1269 | */ | |
1270 | spin_lock(&ctx->lock); | |
1271 | while (!list_empty(list)) { | |
1272 | struct request *rq; | |
1273 | ||
1274 | rq = list_first_entry(list, struct request, queuelist); | |
e57690fe | 1275 | BUG_ON(rq->mq_ctx != ctx); |
320ae51f | 1276 | list_del_init(&rq->queuelist); |
e57690fe | 1277 | __blk_mq_insert_req_list(hctx, rq, false); |
320ae51f | 1278 | } |
cfd0c552 | 1279 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f | 1280 | spin_unlock(&ctx->lock); |
320ae51f JA |
1281 | } |
1282 | ||
1283 | static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b) | |
1284 | { | |
1285 | struct request *rqa = container_of(a, struct request, queuelist); | |
1286 | struct request *rqb = container_of(b, struct request, queuelist); | |
1287 | ||
1288 | return !(rqa->mq_ctx < rqb->mq_ctx || | |
1289 | (rqa->mq_ctx == rqb->mq_ctx && | |
1290 | blk_rq_pos(rqa) < blk_rq_pos(rqb))); | |
1291 | } | |
1292 | ||
1293 | void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) | |
1294 | { | |
1295 | struct blk_mq_ctx *this_ctx; | |
1296 | struct request_queue *this_q; | |
1297 | struct request *rq; | |
1298 | LIST_HEAD(list); | |
1299 | LIST_HEAD(ctx_list); | |
1300 | unsigned int depth; | |
1301 | ||
1302 | list_splice_init(&plug->mq_list, &list); | |
1303 | ||
1304 | list_sort(NULL, &list, plug_ctx_cmp); | |
1305 | ||
1306 | this_q = NULL; | |
1307 | this_ctx = NULL; | |
1308 | depth = 0; | |
1309 | ||
1310 | while (!list_empty(&list)) { | |
1311 | rq = list_entry_rq(list.next); | |
1312 | list_del_init(&rq->queuelist); | |
1313 | BUG_ON(!rq->q); | |
1314 | if (rq->mq_ctx != this_ctx) { | |
1315 | if (this_ctx) { | |
bd166ef1 JA |
1316 | trace_block_unplug(this_q, depth, from_schedule); |
1317 | blk_mq_sched_insert_requests(this_q, this_ctx, | |
1318 | &ctx_list, | |
1319 | from_schedule); | |
320ae51f JA |
1320 | } |
1321 | ||
1322 | this_ctx = rq->mq_ctx; | |
1323 | this_q = rq->q; | |
1324 | depth = 0; | |
1325 | } | |
1326 | ||
1327 | depth++; | |
1328 | list_add_tail(&rq->queuelist, &ctx_list); | |
1329 | } | |
1330 | ||
1331 | /* | |
1332 | * If 'this_ctx' is set, we know we have entries to complete | |
1333 | * on 'ctx_list'. Do those. | |
1334 | */ | |
1335 | if (this_ctx) { | |
bd166ef1 JA |
1336 | trace_block_unplug(this_q, depth, from_schedule); |
1337 | blk_mq_sched_insert_requests(this_q, this_ctx, &ctx_list, | |
1338 | from_schedule); | |
320ae51f JA |
1339 | } |
1340 | } | |
1341 | ||
1342 | static void blk_mq_bio_to_request(struct request *rq, struct bio *bio) | |
1343 | { | |
1344 | init_request_from_bio(rq, bio); | |
4b570521 | 1345 | |
6e85eaf3 | 1346 | blk_account_io_start(rq, true); |
320ae51f JA |
1347 | } |
1348 | ||
274a5843 JA |
1349 | static inline bool hctx_allow_merges(struct blk_mq_hw_ctx *hctx) |
1350 | { | |
1351 | return (hctx->flags & BLK_MQ_F_SHOULD_MERGE) && | |
1352 | !blk_queue_nomerges(hctx->queue); | |
1353 | } | |
1354 | ||
07068d5b JA |
1355 | static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx, |
1356 | struct blk_mq_ctx *ctx, | |
1357 | struct request *rq, struct bio *bio) | |
320ae51f | 1358 | { |
e18378a6 | 1359 | if (!hctx_allow_merges(hctx) || !bio_mergeable(bio)) { |
07068d5b JA |
1360 | blk_mq_bio_to_request(rq, bio); |
1361 | spin_lock(&ctx->lock); | |
1362 | insert_rq: | |
1363 | __blk_mq_insert_request(hctx, rq, false); | |
1364 | spin_unlock(&ctx->lock); | |
1365 | return false; | |
1366 | } else { | |
274a5843 JA |
1367 | struct request_queue *q = hctx->queue; |
1368 | ||
07068d5b JA |
1369 | spin_lock(&ctx->lock); |
1370 | if (!blk_mq_attempt_merge(q, ctx, bio)) { | |
1371 | blk_mq_bio_to_request(rq, bio); | |
1372 | goto insert_rq; | |
1373 | } | |
320ae51f | 1374 | |
07068d5b | 1375 | spin_unlock(&ctx->lock); |
bd166ef1 | 1376 | __blk_mq_finish_request(hctx, ctx, rq); |
07068d5b | 1377 | return true; |
14ec77f3 | 1378 | } |
07068d5b | 1379 | } |
14ec77f3 | 1380 | |
fd2d3326 JA |
1381 | static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq) |
1382 | { | |
bd166ef1 JA |
1383 | if (rq->tag != -1) |
1384 | return blk_tag_to_qc_t(rq->tag, hctx->queue_num, false); | |
1385 | ||
1386 | return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true); | |
fd2d3326 JA |
1387 | } |
1388 | ||
066a4a73 | 1389 | static void blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie) |
f984df1f | 1390 | { |
f984df1f | 1391 | struct request_queue *q = rq->q; |
f984df1f SL |
1392 | struct blk_mq_queue_data bd = { |
1393 | .rq = rq, | |
1394 | .list = NULL, | |
1395 | .last = 1 | |
1396 | }; | |
bd166ef1 JA |
1397 | struct blk_mq_hw_ctx *hctx; |
1398 | blk_qc_t new_cookie; | |
1399 | int ret; | |
f984df1f | 1400 | |
bd166ef1 | 1401 | if (q->elevator) |
2253efc8 BVA |
1402 | goto insert; |
1403 | ||
bd166ef1 JA |
1404 | if (!blk_mq_get_driver_tag(rq, &hctx, false)) |
1405 | goto insert; | |
1406 | ||
1407 | new_cookie = request_to_qc_t(hctx, rq); | |
1408 | ||
f984df1f SL |
1409 | /* |
1410 | * For OK queue, we are done. For error, kill it. Any other | |
1411 | * error (busy), just add it to our list as we previously | |
1412 | * would have done | |
1413 | */ | |
1414 | ret = q->mq_ops->queue_rq(hctx, &bd); | |
7b371636 JA |
1415 | if (ret == BLK_MQ_RQ_QUEUE_OK) { |
1416 | *cookie = new_cookie; | |
2253efc8 | 1417 | return; |
7b371636 | 1418 | } |
f984df1f | 1419 | |
7b371636 JA |
1420 | __blk_mq_requeue_request(rq); |
1421 | ||
1422 | if (ret == BLK_MQ_RQ_QUEUE_ERROR) { | |
1423 | *cookie = BLK_QC_T_NONE; | |
1424 | rq->errors = -EIO; | |
1425 | blk_mq_end_request(rq, rq->errors); | |
2253efc8 | 1426 | return; |
f984df1f | 1427 | } |
7b371636 | 1428 | |
2253efc8 | 1429 | insert: |
bd6737f1 | 1430 | blk_mq_sched_insert_request(rq, false, true, true, false); |
f984df1f SL |
1431 | } |
1432 | ||
07068d5b JA |
1433 | /* |
1434 | * Multiple hardware queue variant. This will not use per-process plugs, | |
1435 | * but will attempt to bypass the hctx queueing if we can go straight to | |
1436 | * hardware for SYNC IO. | |
1437 | */ | |
dece1635 | 1438 | static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) |
07068d5b | 1439 | { |
ef295ecf | 1440 | const int is_sync = op_is_sync(bio->bi_opf); |
f73f44eb | 1441 | const int is_flush_fua = op_is_flush(bio->bi_opf); |
5a797e00 | 1442 | struct blk_mq_alloc_data data = { .flags = 0 }; |
07068d5b | 1443 | struct request *rq; |
6a83e74d | 1444 | unsigned int request_count = 0, srcu_idx; |
f984df1f | 1445 | struct blk_plug *plug; |
5b3f341f | 1446 | struct request *same_queue_rq = NULL; |
7b371636 | 1447 | blk_qc_t cookie; |
87760e5e | 1448 | unsigned int wb_acct; |
07068d5b JA |
1449 | |
1450 | blk_queue_bounce(q, &bio); | |
1451 | ||
1452 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
4246a0b6 | 1453 | bio_io_error(bio); |
dece1635 | 1454 | return BLK_QC_T_NONE; |
07068d5b JA |
1455 | } |
1456 | ||
54efd50b KO |
1457 | blk_queue_split(q, &bio, q->bio_split); |
1458 | ||
87c279e6 OS |
1459 | if (!is_flush_fua && !blk_queue_nomerges(q) && |
1460 | blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq)) | |
1461 | return BLK_QC_T_NONE; | |
f984df1f | 1462 | |
bd166ef1 JA |
1463 | if (blk_mq_sched_bio_merge(q, bio)) |
1464 | return BLK_QC_T_NONE; | |
1465 | ||
87760e5e JA |
1466 | wb_acct = wbt_wait(q->rq_wb, bio, NULL); |
1467 | ||
bd166ef1 JA |
1468 | trace_block_getrq(q, bio, bio->bi_opf); |
1469 | ||
1470 | rq = blk_mq_sched_get_request(q, bio, bio->bi_opf, &data); | |
87760e5e JA |
1471 | if (unlikely(!rq)) { |
1472 | __wbt_done(q->rq_wb, wb_acct); | |
dece1635 | 1473 | return BLK_QC_T_NONE; |
87760e5e JA |
1474 | } |
1475 | ||
1476 | wbt_track(&rq->issue_stat, wb_acct); | |
07068d5b | 1477 | |
fd2d3326 | 1478 | cookie = request_to_qc_t(data.hctx, rq); |
07068d5b JA |
1479 | |
1480 | if (unlikely(is_flush_fua)) { | |
0c2a6fe4 JA |
1481 | if (q->elevator) |
1482 | goto elv_insert; | |
07068d5b JA |
1483 | blk_mq_bio_to_request(rq, bio); |
1484 | blk_insert_flush(rq); | |
0c2a6fe4 | 1485 | goto run_queue; |
07068d5b JA |
1486 | } |
1487 | ||
f984df1f | 1488 | plug = current->plug; |
e167dfb5 JA |
1489 | /* |
1490 | * If the driver supports defer issued based on 'last', then | |
1491 | * queue it up like normal since we can potentially save some | |
1492 | * CPU this way. | |
1493 | */ | |
f984df1f SL |
1494 | if (((plug && !blk_queue_nomerges(q)) || is_sync) && |
1495 | !(data.hctx->flags & BLK_MQ_F_DEFER_ISSUE)) { | |
1496 | struct request *old_rq = NULL; | |
07068d5b JA |
1497 | |
1498 | blk_mq_bio_to_request(rq, bio); | |
07068d5b JA |
1499 | |
1500 | /* | |
6a83e74d | 1501 | * We do limited plugging. If the bio can be merged, do that. |
f984df1f SL |
1502 | * Otherwise the existing request in the plug list will be |
1503 | * issued. So the plug list will have one request at most | |
07068d5b | 1504 | */ |
f984df1f | 1505 | if (plug) { |
5b3f341f SL |
1506 | /* |
1507 | * The plug list might get flushed before this. If that | |
b094f89c JA |
1508 | * happens, same_queue_rq is invalid and plug list is |
1509 | * empty | |
1510 | */ | |
5b3f341f SL |
1511 | if (same_queue_rq && !list_empty(&plug->mq_list)) { |
1512 | old_rq = same_queue_rq; | |
f984df1f | 1513 | list_del_init(&old_rq->queuelist); |
07068d5b | 1514 | } |
f984df1f SL |
1515 | list_add_tail(&rq->queuelist, &plug->mq_list); |
1516 | } else /* is_sync */ | |
1517 | old_rq = rq; | |
1518 | blk_mq_put_ctx(data.ctx); | |
1519 | if (!old_rq) | |
7b371636 | 1520 | goto done; |
6a83e74d BVA |
1521 | |
1522 | if (!(data.hctx->flags & BLK_MQ_F_BLOCKING)) { | |
1523 | rcu_read_lock(); | |
066a4a73 | 1524 | blk_mq_try_issue_directly(old_rq, &cookie); |
6a83e74d BVA |
1525 | rcu_read_unlock(); |
1526 | } else { | |
1527 | srcu_idx = srcu_read_lock(&data.hctx->queue_rq_srcu); | |
066a4a73 | 1528 | blk_mq_try_issue_directly(old_rq, &cookie); |
6a83e74d BVA |
1529 | srcu_read_unlock(&data.hctx->queue_rq_srcu, srcu_idx); |
1530 | } | |
7b371636 | 1531 | goto done; |
07068d5b JA |
1532 | } |
1533 | ||
bd166ef1 | 1534 | if (q->elevator) { |
0c2a6fe4 | 1535 | elv_insert: |
bd166ef1 JA |
1536 | blk_mq_put_ctx(data.ctx); |
1537 | blk_mq_bio_to_request(rq, bio); | |
0abad774 | 1538 | blk_mq_sched_insert_request(rq, false, true, |
bd6737f1 | 1539 | !is_sync || is_flush_fua, true); |
bd166ef1 JA |
1540 | goto done; |
1541 | } | |
07068d5b JA |
1542 | if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { |
1543 | /* | |
1544 | * For a SYNC request, send it to the hardware immediately. For | |
1545 | * an ASYNC request, just ensure that we run it later on. The | |
1546 | * latter allows for merging opportunities and more efficient | |
1547 | * dispatching. | |
1548 | */ | |
0c2a6fe4 | 1549 | run_queue: |
07068d5b JA |
1550 | blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); |
1551 | } | |
07068d5b | 1552 | blk_mq_put_ctx(data.ctx); |
7b371636 JA |
1553 | done: |
1554 | return cookie; | |
07068d5b JA |
1555 | } |
1556 | ||
1557 | /* | |
1558 | * Single hardware queue variant. This will attempt to use any per-process | |
1559 | * plug for merging and IO deferral. | |
1560 | */ | |
dece1635 | 1561 | static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio) |
07068d5b | 1562 | { |
ef295ecf | 1563 | const int is_sync = op_is_sync(bio->bi_opf); |
f73f44eb | 1564 | const int is_flush_fua = op_is_flush(bio->bi_opf); |
e6c4438b JM |
1565 | struct blk_plug *plug; |
1566 | unsigned int request_count = 0; | |
5a797e00 | 1567 | struct blk_mq_alloc_data data = { .flags = 0 }; |
07068d5b | 1568 | struct request *rq; |
7b371636 | 1569 | blk_qc_t cookie; |
87760e5e | 1570 | unsigned int wb_acct; |
07068d5b | 1571 | |
07068d5b JA |
1572 | blk_queue_bounce(q, &bio); |
1573 | ||
1574 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
4246a0b6 | 1575 | bio_io_error(bio); |
dece1635 | 1576 | return BLK_QC_T_NONE; |
07068d5b JA |
1577 | } |
1578 | ||
54efd50b KO |
1579 | blk_queue_split(q, &bio, q->bio_split); |
1580 | ||
87c279e6 OS |
1581 | if (!is_flush_fua && !blk_queue_nomerges(q)) { |
1582 | if (blk_attempt_plug_merge(q, bio, &request_count, NULL)) | |
1583 | return BLK_QC_T_NONE; | |
1584 | } else | |
1585 | request_count = blk_plug_queued_count(q); | |
07068d5b | 1586 | |
bd166ef1 JA |
1587 | if (blk_mq_sched_bio_merge(q, bio)) |
1588 | return BLK_QC_T_NONE; | |
1589 | ||
87760e5e JA |
1590 | wb_acct = wbt_wait(q->rq_wb, bio, NULL); |
1591 | ||
bd166ef1 JA |
1592 | trace_block_getrq(q, bio, bio->bi_opf); |
1593 | ||
1594 | rq = blk_mq_sched_get_request(q, bio, bio->bi_opf, &data); | |
87760e5e JA |
1595 | if (unlikely(!rq)) { |
1596 | __wbt_done(q->rq_wb, wb_acct); | |
dece1635 | 1597 | return BLK_QC_T_NONE; |
87760e5e JA |
1598 | } |
1599 | ||
1600 | wbt_track(&rq->issue_stat, wb_acct); | |
320ae51f | 1601 | |
fd2d3326 | 1602 | cookie = request_to_qc_t(data.hctx, rq); |
320ae51f JA |
1603 | |
1604 | if (unlikely(is_flush_fua)) { | |
0c2a6fe4 JA |
1605 | if (q->elevator) |
1606 | goto elv_insert; | |
320ae51f | 1607 | blk_mq_bio_to_request(rq, bio); |
320ae51f | 1608 | blk_insert_flush(rq); |
0c2a6fe4 | 1609 | goto run_queue; |
320ae51f JA |
1610 | } |
1611 | ||
1612 | /* | |
1613 | * A task plug currently exists. Since this is completely lockless, | |
1614 | * utilize that to temporarily store requests until the task is | |
1615 | * either done or scheduled away. | |
1616 | */ | |
e6c4438b JM |
1617 | plug = current->plug; |
1618 | if (plug) { | |
600271d9 SL |
1619 | struct request *last = NULL; |
1620 | ||
e6c4438b | 1621 | blk_mq_bio_to_request(rq, bio); |
0a6219a9 ML |
1622 | |
1623 | /* | |
1624 | * @request_count may become stale because of schedule | |
1625 | * out, so check the list again. | |
1626 | */ | |
1627 | if (list_empty(&plug->mq_list)) | |
1628 | request_count = 0; | |
676d0607 | 1629 | if (!request_count) |
e6c4438b | 1630 | trace_block_plug(q); |
600271d9 SL |
1631 | else |
1632 | last = list_entry_rq(plug->mq_list.prev); | |
b094f89c JA |
1633 | |
1634 | blk_mq_put_ctx(data.ctx); | |
1635 | ||
600271d9 SL |
1636 | if (request_count >= BLK_MAX_REQUEST_COUNT || (last && |
1637 | blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE)) { | |
e6c4438b JM |
1638 | blk_flush_plug_list(plug, false); |
1639 | trace_block_plug(q); | |
320ae51f | 1640 | } |
b094f89c | 1641 | |
e6c4438b | 1642 | list_add_tail(&rq->queuelist, &plug->mq_list); |
7b371636 | 1643 | return cookie; |
320ae51f JA |
1644 | } |
1645 | ||
bd166ef1 | 1646 | if (q->elevator) { |
0c2a6fe4 | 1647 | elv_insert: |
bd166ef1 JA |
1648 | blk_mq_put_ctx(data.ctx); |
1649 | blk_mq_bio_to_request(rq, bio); | |
0abad774 | 1650 | blk_mq_sched_insert_request(rq, false, true, |
bd6737f1 | 1651 | !is_sync || is_flush_fua, true); |
bd166ef1 JA |
1652 | goto done; |
1653 | } | |
07068d5b JA |
1654 | if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { |
1655 | /* | |
1656 | * For a SYNC request, send it to the hardware immediately. For | |
1657 | * an ASYNC request, just ensure that we run it later on. The | |
1658 | * latter allows for merging opportunities and more efficient | |
1659 | * dispatching. | |
1660 | */ | |
0c2a6fe4 | 1661 | run_queue: |
07068d5b | 1662 | blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); |
320ae51f JA |
1663 | } |
1664 | ||
07068d5b | 1665 | blk_mq_put_ctx(data.ctx); |
bd166ef1 | 1666 | done: |
7b371636 | 1667 | return cookie; |
320ae51f JA |
1668 | } |
1669 | ||
cc71a6f4 JA |
1670 | void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, |
1671 | unsigned int hctx_idx) | |
95363efd | 1672 | { |
e9b267d9 | 1673 | struct page *page; |
320ae51f | 1674 | |
24d2f903 | 1675 | if (tags->rqs && set->ops->exit_request) { |
e9b267d9 | 1676 | int i; |
320ae51f | 1677 | |
24d2f903 | 1678 | for (i = 0; i < tags->nr_tags; i++) { |
2af8cbe3 JA |
1679 | struct request *rq = tags->static_rqs[i]; |
1680 | ||
1681 | if (!rq) | |
e9b267d9 | 1682 | continue; |
2af8cbe3 | 1683 | set->ops->exit_request(set->driver_data, rq, |
24d2f903 | 1684 | hctx_idx, i); |
2af8cbe3 | 1685 | tags->static_rqs[i] = NULL; |
e9b267d9 | 1686 | } |
320ae51f | 1687 | } |
320ae51f | 1688 | |
24d2f903 CH |
1689 | while (!list_empty(&tags->page_list)) { |
1690 | page = list_first_entry(&tags->page_list, struct page, lru); | |
6753471c | 1691 | list_del_init(&page->lru); |
f75782e4 CM |
1692 | /* |
1693 | * Remove kmemleak object previously allocated in | |
1694 | * blk_mq_init_rq_map(). | |
1695 | */ | |
1696 | kmemleak_free(page_address(page)); | |
320ae51f JA |
1697 | __free_pages(page, page->private); |
1698 | } | |
cc71a6f4 | 1699 | } |
320ae51f | 1700 | |
cc71a6f4 JA |
1701 | void blk_mq_free_rq_map(struct blk_mq_tags *tags) |
1702 | { | |
24d2f903 | 1703 | kfree(tags->rqs); |
cc71a6f4 | 1704 | tags->rqs = NULL; |
2af8cbe3 JA |
1705 | kfree(tags->static_rqs); |
1706 | tags->static_rqs = NULL; | |
320ae51f | 1707 | |
24d2f903 | 1708 | blk_mq_free_tags(tags); |
320ae51f JA |
1709 | } |
1710 | ||
cc71a6f4 JA |
1711 | struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, |
1712 | unsigned int hctx_idx, | |
1713 | unsigned int nr_tags, | |
1714 | unsigned int reserved_tags) | |
320ae51f | 1715 | { |
24d2f903 | 1716 | struct blk_mq_tags *tags; |
320ae51f | 1717 | |
cc71a6f4 | 1718 | tags = blk_mq_init_tags(nr_tags, reserved_tags, |
24391c0d SL |
1719 | set->numa_node, |
1720 | BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags)); | |
24d2f903 CH |
1721 | if (!tags) |
1722 | return NULL; | |
320ae51f | 1723 | |
cc71a6f4 | 1724 | tags->rqs = kzalloc_node(nr_tags * sizeof(struct request *), |
36e1f3d1 | 1725 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, |
a5164405 | 1726 | set->numa_node); |
24d2f903 CH |
1727 | if (!tags->rqs) { |
1728 | blk_mq_free_tags(tags); | |
1729 | return NULL; | |
1730 | } | |
320ae51f | 1731 | |
2af8cbe3 JA |
1732 | tags->static_rqs = kzalloc_node(nr_tags * sizeof(struct request *), |
1733 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY, | |
1734 | set->numa_node); | |
1735 | if (!tags->static_rqs) { | |
1736 | kfree(tags->rqs); | |
1737 | blk_mq_free_tags(tags); | |
1738 | return NULL; | |
1739 | } | |
1740 | ||
cc71a6f4 JA |
1741 | return tags; |
1742 | } | |
1743 | ||
1744 | static size_t order_to_size(unsigned int order) | |
1745 | { | |
1746 | return (size_t)PAGE_SIZE << order; | |
1747 | } | |
1748 | ||
1749 | int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags, | |
1750 | unsigned int hctx_idx, unsigned int depth) | |
1751 | { | |
1752 | unsigned int i, j, entries_per_page, max_order = 4; | |
1753 | size_t rq_size, left; | |
1754 | ||
1755 | INIT_LIST_HEAD(&tags->page_list); | |
1756 | ||
320ae51f JA |
1757 | /* |
1758 | * rq_size is the size of the request plus driver payload, rounded | |
1759 | * to the cacheline size | |
1760 | */ | |
24d2f903 | 1761 | rq_size = round_up(sizeof(struct request) + set->cmd_size, |
320ae51f | 1762 | cache_line_size()); |
cc71a6f4 | 1763 | left = rq_size * depth; |
320ae51f | 1764 | |
cc71a6f4 | 1765 | for (i = 0; i < depth; ) { |
320ae51f JA |
1766 | int this_order = max_order; |
1767 | struct page *page; | |
1768 | int to_do; | |
1769 | void *p; | |
1770 | ||
b3a834b1 | 1771 | while (this_order && left < order_to_size(this_order - 1)) |
320ae51f JA |
1772 | this_order--; |
1773 | ||
1774 | do { | |
a5164405 | 1775 | page = alloc_pages_node(set->numa_node, |
36e1f3d1 | 1776 | GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO, |
a5164405 | 1777 | this_order); |
320ae51f JA |
1778 | if (page) |
1779 | break; | |
1780 | if (!this_order--) | |
1781 | break; | |
1782 | if (order_to_size(this_order) < rq_size) | |
1783 | break; | |
1784 | } while (1); | |
1785 | ||
1786 | if (!page) | |
24d2f903 | 1787 | goto fail; |
320ae51f JA |
1788 | |
1789 | page->private = this_order; | |
24d2f903 | 1790 | list_add_tail(&page->lru, &tags->page_list); |
320ae51f JA |
1791 | |
1792 | p = page_address(page); | |
f75782e4 CM |
1793 | /* |
1794 | * Allow kmemleak to scan these pages as they contain pointers | |
1795 | * to additional allocations like via ops->init_request(). | |
1796 | */ | |
36e1f3d1 | 1797 | kmemleak_alloc(p, order_to_size(this_order), 1, GFP_NOIO); |
320ae51f | 1798 | entries_per_page = order_to_size(this_order) / rq_size; |
cc71a6f4 | 1799 | to_do = min(entries_per_page, depth - i); |
320ae51f JA |
1800 | left -= to_do * rq_size; |
1801 | for (j = 0; j < to_do; j++) { | |
2af8cbe3 JA |
1802 | struct request *rq = p; |
1803 | ||
1804 | tags->static_rqs[i] = rq; | |
24d2f903 CH |
1805 | if (set->ops->init_request) { |
1806 | if (set->ops->init_request(set->driver_data, | |
2af8cbe3 | 1807 | rq, hctx_idx, i, |
a5164405 | 1808 | set->numa_node)) { |
2af8cbe3 | 1809 | tags->static_rqs[i] = NULL; |
24d2f903 | 1810 | goto fail; |
a5164405 | 1811 | } |
e9b267d9 CH |
1812 | } |
1813 | ||
320ae51f JA |
1814 | p += rq_size; |
1815 | i++; | |
1816 | } | |
1817 | } | |
cc71a6f4 | 1818 | return 0; |
320ae51f | 1819 | |
24d2f903 | 1820 | fail: |
cc71a6f4 JA |
1821 | blk_mq_free_rqs(set, tags, hctx_idx); |
1822 | return -ENOMEM; | |
320ae51f JA |
1823 | } |
1824 | ||
e57690fe JA |
1825 | /* |
1826 | * 'cpu' is going away. splice any existing rq_list entries from this | |
1827 | * software queue to the hw queue dispatch list, and ensure that it | |
1828 | * gets run. | |
1829 | */ | |
9467f859 | 1830 | static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node) |
484b4061 | 1831 | { |
9467f859 | 1832 | struct blk_mq_hw_ctx *hctx; |
484b4061 JA |
1833 | struct blk_mq_ctx *ctx; |
1834 | LIST_HEAD(tmp); | |
1835 | ||
9467f859 | 1836 | hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_dead); |
e57690fe | 1837 | ctx = __blk_mq_get_ctx(hctx->queue, cpu); |
484b4061 JA |
1838 | |
1839 | spin_lock(&ctx->lock); | |
1840 | if (!list_empty(&ctx->rq_list)) { | |
1841 | list_splice_init(&ctx->rq_list, &tmp); | |
1842 | blk_mq_hctx_clear_pending(hctx, ctx); | |
1843 | } | |
1844 | spin_unlock(&ctx->lock); | |
1845 | ||
1846 | if (list_empty(&tmp)) | |
9467f859 | 1847 | return 0; |
484b4061 | 1848 | |
e57690fe JA |
1849 | spin_lock(&hctx->lock); |
1850 | list_splice_tail_init(&tmp, &hctx->dispatch); | |
1851 | spin_unlock(&hctx->lock); | |
484b4061 JA |
1852 | |
1853 | blk_mq_run_hw_queue(hctx, true); | |
9467f859 | 1854 | return 0; |
484b4061 JA |
1855 | } |
1856 | ||
9467f859 | 1857 | static void blk_mq_remove_cpuhp(struct blk_mq_hw_ctx *hctx) |
484b4061 | 1858 | { |
9467f859 TG |
1859 | cpuhp_state_remove_instance_nocalls(CPUHP_BLK_MQ_DEAD, |
1860 | &hctx->cpuhp_dead); | |
484b4061 JA |
1861 | } |
1862 | ||
c3b4afca | 1863 | /* hctx->ctxs will be freed in queue's release handler */ |
08e98fc6 ML |
1864 | static void blk_mq_exit_hctx(struct request_queue *q, |
1865 | struct blk_mq_tag_set *set, | |
1866 | struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) | |
1867 | { | |
f70ced09 ML |
1868 | unsigned flush_start_tag = set->queue_depth; |
1869 | ||
08e98fc6 ML |
1870 | blk_mq_tag_idle(hctx); |
1871 | ||
f70ced09 ML |
1872 | if (set->ops->exit_request) |
1873 | set->ops->exit_request(set->driver_data, | |
1874 | hctx->fq->flush_rq, hctx_idx, | |
1875 | flush_start_tag + hctx_idx); | |
1876 | ||
08e98fc6 ML |
1877 | if (set->ops->exit_hctx) |
1878 | set->ops->exit_hctx(hctx, hctx_idx); | |
1879 | ||
6a83e74d BVA |
1880 | if (hctx->flags & BLK_MQ_F_BLOCKING) |
1881 | cleanup_srcu_struct(&hctx->queue_rq_srcu); | |
1882 | ||
9467f859 | 1883 | blk_mq_remove_cpuhp(hctx); |
f70ced09 | 1884 | blk_free_flush_queue(hctx->fq); |
88459642 | 1885 | sbitmap_free(&hctx->ctx_map); |
08e98fc6 ML |
1886 | } |
1887 | ||
624dbe47 ML |
1888 | static void blk_mq_exit_hw_queues(struct request_queue *q, |
1889 | struct blk_mq_tag_set *set, int nr_queue) | |
1890 | { | |
1891 | struct blk_mq_hw_ctx *hctx; | |
1892 | unsigned int i; | |
1893 | ||
1894 | queue_for_each_hw_ctx(q, hctx, i) { | |
1895 | if (i == nr_queue) | |
1896 | break; | |
08e98fc6 | 1897 | blk_mq_exit_hctx(q, set, hctx, i); |
624dbe47 | 1898 | } |
624dbe47 ML |
1899 | } |
1900 | ||
1901 | static void blk_mq_free_hw_queues(struct request_queue *q, | |
1902 | struct blk_mq_tag_set *set) | |
1903 | { | |
1904 | struct blk_mq_hw_ctx *hctx; | |
1905 | unsigned int i; | |
1906 | ||
e09aae7e | 1907 | queue_for_each_hw_ctx(q, hctx, i) |
624dbe47 | 1908 | free_cpumask_var(hctx->cpumask); |
624dbe47 ML |
1909 | } |
1910 | ||
08e98fc6 ML |
1911 | static int blk_mq_init_hctx(struct request_queue *q, |
1912 | struct blk_mq_tag_set *set, | |
1913 | struct blk_mq_hw_ctx *hctx, unsigned hctx_idx) | |
320ae51f | 1914 | { |
08e98fc6 | 1915 | int node; |
f70ced09 | 1916 | unsigned flush_start_tag = set->queue_depth; |
08e98fc6 ML |
1917 | |
1918 | node = hctx->numa_node; | |
1919 | if (node == NUMA_NO_NODE) | |
1920 | node = hctx->numa_node = set->numa_node; | |
1921 | ||
27489a3c | 1922 | INIT_WORK(&hctx->run_work, blk_mq_run_work_fn); |
08e98fc6 ML |
1923 | INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn); |
1924 | spin_lock_init(&hctx->lock); | |
1925 | INIT_LIST_HEAD(&hctx->dispatch); | |
1926 | hctx->queue = q; | |
1927 | hctx->queue_num = hctx_idx; | |
2404e607 | 1928 | hctx->flags = set->flags & ~BLK_MQ_F_TAG_SHARED; |
08e98fc6 | 1929 | |
9467f859 | 1930 | cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, &hctx->cpuhp_dead); |
08e98fc6 ML |
1931 | |
1932 | hctx->tags = set->tags[hctx_idx]; | |
320ae51f JA |
1933 | |
1934 | /* | |
08e98fc6 ML |
1935 | * Allocate space for all possible cpus to avoid allocation at |
1936 | * runtime | |
320ae51f | 1937 | */ |
08e98fc6 ML |
1938 | hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *), |
1939 | GFP_KERNEL, node); | |
1940 | if (!hctx->ctxs) | |
1941 | goto unregister_cpu_notifier; | |
320ae51f | 1942 | |
88459642 OS |
1943 | if (sbitmap_init_node(&hctx->ctx_map, nr_cpu_ids, ilog2(8), GFP_KERNEL, |
1944 | node)) | |
08e98fc6 | 1945 | goto free_ctxs; |
320ae51f | 1946 | |
08e98fc6 | 1947 | hctx->nr_ctx = 0; |
320ae51f | 1948 | |
08e98fc6 ML |
1949 | if (set->ops->init_hctx && |
1950 | set->ops->init_hctx(hctx, set->driver_data, hctx_idx)) | |
1951 | goto free_bitmap; | |
320ae51f | 1952 | |
f70ced09 ML |
1953 | hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size); |
1954 | if (!hctx->fq) | |
1955 | goto exit_hctx; | |
320ae51f | 1956 | |
f70ced09 ML |
1957 | if (set->ops->init_request && |
1958 | set->ops->init_request(set->driver_data, | |
1959 | hctx->fq->flush_rq, hctx_idx, | |
1960 | flush_start_tag + hctx_idx, node)) | |
1961 | goto free_fq; | |
320ae51f | 1962 | |
6a83e74d BVA |
1963 | if (hctx->flags & BLK_MQ_F_BLOCKING) |
1964 | init_srcu_struct(&hctx->queue_rq_srcu); | |
1965 | ||
08e98fc6 | 1966 | return 0; |
320ae51f | 1967 | |
f70ced09 ML |
1968 | free_fq: |
1969 | kfree(hctx->fq); | |
1970 | exit_hctx: | |
1971 | if (set->ops->exit_hctx) | |
1972 | set->ops->exit_hctx(hctx, hctx_idx); | |
08e98fc6 | 1973 | free_bitmap: |
88459642 | 1974 | sbitmap_free(&hctx->ctx_map); |
08e98fc6 ML |
1975 | free_ctxs: |
1976 | kfree(hctx->ctxs); | |
1977 | unregister_cpu_notifier: | |
9467f859 | 1978 | blk_mq_remove_cpuhp(hctx); |
08e98fc6 ML |
1979 | return -1; |
1980 | } | |
320ae51f | 1981 | |
320ae51f JA |
1982 | static void blk_mq_init_cpu_queues(struct request_queue *q, |
1983 | unsigned int nr_hw_queues) | |
1984 | { | |
1985 | unsigned int i; | |
1986 | ||
1987 | for_each_possible_cpu(i) { | |
1988 | struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i); | |
1989 | struct blk_mq_hw_ctx *hctx; | |
1990 | ||
1991 | memset(__ctx, 0, sizeof(*__ctx)); | |
1992 | __ctx->cpu = i; | |
1993 | spin_lock_init(&__ctx->lock); | |
1994 | INIT_LIST_HEAD(&__ctx->rq_list); | |
1995 | __ctx->queue = q; | |
cf43e6be JA |
1996 | blk_stat_init(&__ctx->stat[BLK_STAT_READ]); |
1997 | blk_stat_init(&__ctx->stat[BLK_STAT_WRITE]); | |
320ae51f JA |
1998 | |
1999 | /* If the cpu isn't online, the cpu is mapped to first hctx */ | |
320ae51f JA |
2000 | if (!cpu_online(i)) |
2001 | continue; | |
2002 | ||
7d7e0f90 | 2003 | hctx = blk_mq_map_queue(q, i); |
e4043dcf | 2004 | |
320ae51f JA |
2005 | /* |
2006 | * Set local node, IFF we have more than one hw queue. If | |
2007 | * not, we remain on the home node of the device | |
2008 | */ | |
2009 | if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE) | |
bffed457 | 2010 | hctx->numa_node = local_memory_node(cpu_to_node(i)); |
320ae51f JA |
2011 | } |
2012 | } | |
2013 | ||
cc71a6f4 JA |
2014 | static bool __blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, int hctx_idx) |
2015 | { | |
2016 | int ret = 0; | |
2017 | ||
2018 | set->tags[hctx_idx] = blk_mq_alloc_rq_map(set, hctx_idx, | |
2019 | set->queue_depth, set->reserved_tags); | |
2020 | if (!set->tags[hctx_idx]) | |
2021 | return false; | |
2022 | ||
2023 | ret = blk_mq_alloc_rqs(set, set->tags[hctx_idx], hctx_idx, | |
2024 | set->queue_depth); | |
2025 | if (!ret) | |
2026 | return true; | |
2027 | ||
2028 | blk_mq_free_rq_map(set->tags[hctx_idx]); | |
2029 | set->tags[hctx_idx] = NULL; | |
2030 | return false; | |
2031 | } | |
2032 | ||
2033 | static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set, | |
2034 | unsigned int hctx_idx) | |
2035 | { | |
bd166ef1 JA |
2036 | if (set->tags[hctx_idx]) { |
2037 | blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx); | |
2038 | blk_mq_free_rq_map(set->tags[hctx_idx]); | |
2039 | set->tags[hctx_idx] = NULL; | |
2040 | } | |
cc71a6f4 JA |
2041 | } |
2042 | ||
5778322e AM |
2043 | static void blk_mq_map_swqueue(struct request_queue *q, |
2044 | const struct cpumask *online_mask) | |
320ae51f | 2045 | { |
d1b1cea1 | 2046 | unsigned int i, hctx_idx; |
320ae51f JA |
2047 | struct blk_mq_hw_ctx *hctx; |
2048 | struct blk_mq_ctx *ctx; | |
2a34c087 | 2049 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 2050 | |
60de074b AM |
2051 | /* |
2052 | * Avoid others reading imcomplete hctx->cpumask through sysfs | |
2053 | */ | |
2054 | mutex_lock(&q->sysfs_lock); | |
2055 | ||
320ae51f | 2056 | queue_for_each_hw_ctx(q, hctx, i) { |
e4043dcf | 2057 | cpumask_clear(hctx->cpumask); |
320ae51f JA |
2058 | hctx->nr_ctx = 0; |
2059 | } | |
2060 | ||
2061 | /* | |
2062 | * Map software to hardware queues | |
2063 | */ | |
897bb0c7 | 2064 | for_each_possible_cpu(i) { |
320ae51f | 2065 | /* If the cpu isn't online, the cpu is mapped to first hctx */ |
5778322e | 2066 | if (!cpumask_test_cpu(i, online_mask)) |
e4043dcf JA |
2067 | continue; |
2068 | ||
d1b1cea1 GKB |
2069 | hctx_idx = q->mq_map[i]; |
2070 | /* unmapped hw queue can be remapped after CPU topo changed */ | |
cc71a6f4 JA |
2071 | if (!set->tags[hctx_idx] && |
2072 | !__blk_mq_alloc_rq_map(set, hctx_idx)) { | |
d1b1cea1 GKB |
2073 | /* |
2074 | * If tags initialization fail for some hctx, | |
2075 | * that hctx won't be brought online. In this | |
2076 | * case, remap the current ctx to hctx[0] which | |
2077 | * is guaranteed to always have tags allocated | |
2078 | */ | |
cc71a6f4 | 2079 | q->mq_map[i] = 0; |
d1b1cea1 GKB |
2080 | } |
2081 | ||
897bb0c7 | 2082 | ctx = per_cpu_ptr(q->queue_ctx, i); |
7d7e0f90 | 2083 | hctx = blk_mq_map_queue(q, i); |
868f2f0b | 2084 | |
e4043dcf | 2085 | cpumask_set_cpu(i, hctx->cpumask); |
320ae51f JA |
2086 | ctx->index_hw = hctx->nr_ctx; |
2087 | hctx->ctxs[hctx->nr_ctx++] = ctx; | |
2088 | } | |
506e931f | 2089 | |
60de074b AM |
2090 | mutex_unlock(&q->sysfs_lock); |
2091 | ||
506e931f | 2092 | queue_for_each_hw_ctx(q, hctx, i) { |
484b4061 | 2093 | /* |
a68aafa5 JA |
2094 | * If no software queues are mapped to this hardware queue, |
2095 | * disable it and free the request entries. | |
484b4061 JA |
2096 | */ |
2097 | if (!hctx->nr_ctx) { | |
d1b1cea1 GKB |
2098 | /* Never unmap queue 0. We need it as a |
2099 | * fallback in case of a new remap fails | |
2100 | * allocation | |
2101 | */ | |
cc71a6f4 JA |
2102 | if (i && set->tags[i]) |
2103 | blk_mq_free_map_and_requests(set, i); | |
2104 | ||
2a34c087 | 2105 | hctx->tags = NULL; |
484b4061 JA |
2106 | continue; |
2107 | } | |
2108 | ||
2a34c087 ML |
2109 | hctx->tags = set->tags[i]; |
2110 | WARN_ON(!hctx->tags); | |
2111 | ||
889fa31f CY |
2112 | /* |
2113 | * Set the map size to the number of mapped software queues. | |
2114 | * This is more accurate and more efficient than looping | |
2115 | * over all possibly mapped software queues. | |
2116 | */ | |
88459642 | 2117 | sbitmap_resize(&hctx->ctx_map, hctx->nr_ctx); |
889fa31f | 2118 | |
484b4061 JA |
2119 | /* |
2120 | * Initialize batch roundrobin counts | |
2121 | */ | |
506e931f JA |
2122 | hctx->next_cpu = cpumask_first(hctx->cpumask); |
2123 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
2124 | } | |
320ae51f JA |
2125 | } |
2126 | ||
2404e607 | 2127 | static void queue_set_hctx_shared(struct request_queue *q, bool shared) |
0d2602ca JA |
2128 | { |
2129 | struct blk_mq_hw_ctx *hctx; | |
0d2602ca JA |
2130 | int i; |
2131 | ||
2404e607 JM |
2132 | queue_for_each_hw_ctx(q, hctx, i) { |
2133 | if (shared) | |
2134 | hctx->flags |= BLK_MQ_F_TAG_SHARED; | |
2135 | else | |
2136 | hctx->flags &= ~BLK_MQ_F_TAG_SHARED; | |
2137 | } | |
2138 | } | |
2139 | ||
2140 | static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set, bool shared) | |
2141 | { | |
2142 | struct request_queue *q; | |
0d2602ca JA |
2143 | |
2144 | list_for_each_entry(q, &set->tag_list, tag_set_list) { | |
2145 | blk_mq_freeze_queue(q); | |
2404e607 | 2146 | queue_set_hctx_shared(q, shared); |
0d2602ca JA |
2147 | blk_mq_unfreeze_queue(q); |
2148 | } | |
2149 | } | |
2150 | ||
2151 | static void blk_mq_del_queue_tag_set(struct request_queue *q) | |
2152 | { | |
2153 | struct blk_mq_tag_set *set = q->tag_set; | |
2154 | ||
0d2602ca JA |
2155 | mutex_lock(&set->tag_list_lock); |
2156 | list_del_init(&q->tag_set_list); | |
2404e607 JM |
2157 | if (list_is_singular(&set->tag_list)) { |
2158 | /* just transitioned to unshared */ | |
2159 | set->flags &= ~BLK_MQ_F_TAG_SHARED; | |
2160 | /* update existing queue */ | |
2161 | blk_mq_update_tag_set_depth(set, false); | |
2162 | } | |
0d2602ca | 2163 | mutex_unlock(&set->tag_list_lock); |
0d2602ca JA |
2164 | } |
2165 | ||
2166 | static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, | |
2167 | struct request_queue *q) | |
2168 | { | |
2169 | q->tag_set = set; | |
2170 | ||
2171 | mutex_lock(&set->tag_list_lock); | |
2404e607 JM |
2172 | |
2173 | /* Check to see if we're transitioning to shared (from 1 to 2 queues). */ | |
2174 | if (!list_empty(&set->tag_list) && !(set->flags & BLK_MQ_F_TAG_SHARED)) { | |
2175 | set->flags |= BLK_MQ_F_TAG_SHARED; | |
2176 | /* update existing queue */ | |
2177 | blk_mq_update_tag_set_depth(set, true); | |
2178 | } | |
2179 | if (set->flags & BLK_MQ_F_TAG_SHARED) | |
2180 | queue_set_hctx_shared(q, true); | |
0d2602ca | 2181 | list_add_tail(&q->tag_set_list, &set->tag_list); |
2404e607 | 2182 | |
0d2602ca JA |
2183 | mutex_unlock(&set->tag_list_lock); |
2184 | } | |
2185 | ||
e09aae7e ML |
2186 | /* |
2187 | * It is the actual release handler for mq, but we do it from | |
2188 | * request queue's release handler for avoiding use-after-free | |
2189 | * and headache because q->mq_kobj shouldn't have been introduced, | |
2190 | * but we can't group ctx/kctx kobj without it. | |
2191 | */ | |
2192 | void blk_mq_release(struct request_queue *q) | |
2193 | { | |
2194 | struct blk_mq_hw_ctx *hctx; | |
2195 | unsigned int i; | |
2196 | ||
bd166ef1 JA |
2197 | blk_mq_sched_teardown(q); |
2198 | ||
e09aae7e | 2199 | /* hctx kobj stays in hctx */ |
c3b4afca ML |
2200 | queue_for_each_hw_ctx(q, hctx, i) { |
2201 | if (!hctx) | |
2202 | continue; | |
2203 | kfree(hctx->ctxs); | |
e09aae7e | 2204 | kfree(hctx); |
c3b4afca | 2205 | } |
e09aae7e | 2206 | |
a723bab3 AM |
2207 | q->mq_map = NULL; |
2208 | ||
e09aae7e ML |
2209 | kfree(q->queue_hw_ctx); |
2210 | ||
2211 | /* ctx kobj stays in queue_ctx */ | |
2212 | free_percpu(q->queue_ctx); | |
2213 | } | |
2214 | ||
24d2f903 | 2215 | struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) |
b62c21b7 MS |
2216 | { |
2217 | struct request_queue *uninit_q, *q; | |
2218 | ||
2219 | uninit_q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node); | |
2220 | if (!uninit_q) | |
2221 | return ERR_PTR(-ENOMEM); | |
2222 | ||
2223 | q = blk_mq_init_allocated_queue(set, uninit_q); | |
2224 | if (IS_ERR(q)) | |
2225 | blk_cleanup_queue(uninit_q); | |
2226 | ||
2227 | return q; | |
2228 | } | |
2229 | EXPORT_SYMBOL(blk_mq_init_queue); | |
2230 | ||
868f2f0b KB |
2231 | static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, |
2232 | struct request_queue *q) | |
320ae51f | 2233 | { |
868f2f0b KB |
2234 | int i, j; |
2235 | struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx; | |
f14bbe77 | 2236 | |
868f2f0b | 2237 | blk_mq_sysfs_unregister(q); |
24d2f903 | 2238 | for (i = 0; i < set->nr_hw_queues; i++) { |
868f2f0b | 2239 | int node; |
f14bbe77 | 2240 | |
868f2f0b KB |
2241 | if (hctxs[i]) |
2242 | continue; | |
2243 | ||
2244 | node = blk_mq_hw_queue_to_node(q->mq_map, i); | |
cdef54dd CH |
2245 | hctxs[i] = kzalloc_node(sizeof(struct blk_mq_hw_ctx), |
2246 | GFP_KERNEL, node); | |
320ae51f | 2247 | if (!hctxs[i]) |
868f2f0b | 2248 | break; |
320ae51f | 2249 | |
a86073e4 | 2250 | if (!zalloc_cpumask_var_node(&hctxs[i]->cpumask, GFP_KERNEL, |
868f2f0b KB |
2251 | node)) { |
2252 | kfree(hctxs[i]); | |
2253 | hctxs[i] = NULL; | |
2254 | break; | |
2255 | } | |
e4043dcf | 2256 | |
0d2602ca | 2257 | atomic_set(&hctxs[i]->nr_active, 0); |
f14bbe77 | 2258 | hctxs[i]->numa_node = node; |
320ae51f | 2259 | hctxs[i]->queue_num = i; |
868f2f0b KB |
2260 | |
2261 | if (blk_mq_init_hctx(q, set, hctxs[i], i)) { | |
2262 | free_cpumask_var(hctxs[i]->cpumask); | |
2263 | kfree(hctxs[i]); | |
2264 | hctxs[i] = NULL; | |
2265 | break; | |
2266 | } | |
2267 | blk_mq_hctx_kobj_init(hctxs[i]); | |
320ae51f | 2268 | } |
868f2f0b KB |
2269 | for (j = i; j < q->nr_hw_queues; j++) { |
2270 | struct blk_mq_hw_ctx *hctx = hctxs[j]; | |
2271 | ||
2272 | if (hctx) { | |
cc71a6f4 JA |
2273 | if (hctx->tags) |
2274 | blk_mq_free_map_and_requests(set, j); | |
868f2f0b KB |
2275 | blk_mq_exit_hctx(q, set, hctx, j); |
2276 | free_cpumask_var(hctx->cpumask); | |
2277 | kobject_put(&hctx->kobj); | |
2278 | kfree(hctx->ctxs); | |
2279 | kfree(hctx); | |
2280 | hctxs[j] = NULL; | |
2281 | ||
2282 | } | |
2283 | } | |
2284 | q->nr_hw_queues = i; | |
2285 | blk_mq_sysfs_register(q); | |
2286 | } | |
2287 | ||
2288 | struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, | |
2289 | struct request_queue *q) | |
2290 | { | |
66841672 ML |
2291 | /* mark the queue as mq asap */ |
2292 | q->mq_ops = set->ops; | |
2293 | ||
868f2f0b KB |
2294 | q->queue_ctx = alloc_percpu(struct blk_mq_ctx); |
2295 | if (!q->queue_ctx) | |
c7de5726 | 2296 | goto err_exit; |
868f2f0b KB |
2297 | |
2298 | q->queue_hw_ctx = kzalloc_node(nr_cpu_ids * sizeof(*(q->queue_hw_ctx)), | |
2299 | GFP_KERNEL, set->numa_node); | |
2300 | if (!q->queue_hw_ctx) | |
2301 | goto err_percpu; | |
2302 | ||
bdd17e75 | 2303 | q->mq_map = set->mq_map; |
868f2f0b KB |
2304 | |
2305 | blk_mq_realloc_hw_ctxs(set, q); | |
2306 | if (!q->nr_hw_queues) | |
2307 | goto err_hctxs; | |
320ae51f | 2308 | |
287922eb | 2309 | INIT_WORK(&q->timeout_work, blk_mq_timeout_work); |
e56f698b | 2310 | blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ); |
320ae51f JA |
2311 | |
2312 | q->nr_queues = nr_cpu_ids; | |
320ae51f | 2313 | |
94eddfbe | 2314 | q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; |
320ae51f | 2315 | |
05f1dd53 JA |
2316 | if (!(set->flags & BLK_MQ_F_SG_MERGE)) |
2317 | q->queue_flags |= 1 << QUEUE_FLAG_NO_SG_MERGE; | |
2318 | ||
1be036e9 CH |
2319 | q->sg_reserved_size = INT_MAX; |
2320 | ||
2849450a | 2321 | INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work); |
6fca6a61 CH |
2322 | INIT_LIST_HEAD(&q->requeue_list); |
2323 | spin_lock_init(&q->requeue_lock); | |
2324 | ||
07068d5b JA |
2325 | if (q->nr_hw_queues > 1) |
2326 | blk_queue_make_request(q, blk_mq_make_request); | |
2327 | else | |
2328 | blk_queue_make_request(q, blk_sq_make_request); | |
2329 | ||
eba71768 JA |
2330 | /* |
2331 | * Do this after blk_queue_make_request() overrides it... | |
2332 | */ | |
2333 | q->nr_requests = set->queue_depth; | |
2334 | ||
64f1c21e JA |
2335 | /* |
2336 | * Default to classic polling | |
2337 | */ | |
2338 | q->poll_nsec = -1; | |
2339 | ||
24d2f903 CH |
2340 | if (set->ops->complete) |
2341 | blk_queue_softirq_done(q, set->ops->complete); | |
30a91cb4 | 2342 | |
24d2f903 | 2343 | blk_mq_init_cpu_queues(q, set->nr_hw_queues); |
320ae51f | 2344 | |
5778322e | 2345 | get_online_cpus(); |
320ae51f | 2346 | mutex_lock(&all_q_mutex); |
320ae51f | 2347 | |
4593fdbe | 2348 | list_add_tail(&q->all_q_node, &all_q_list); |
0d2602ca | 2349 | blk_mq_add_queue_tag_set(set, q); |
5778322e | 2350 | blk_mq_map_swqueue(q, cpu_online_mask); |
484b4061 | 2351 | |
4593fdbe | 2352 | mutex_unlock(&all_q_mutex); |
5778322e | 2353 | put_online_cpus(); |
4593fdbe | 2354 | |
d3484991 JA |
2355 | if (!(set->flags & BLK_MQ_F_NO_SCHED)) { |
2356 | int ret; | |
2357 | ||
2358 | ret = blk_mq_sched_init(q); | |
2359 | if (ret) | |
2360 | return ERR_PTR(ret); | |
2361 | } | |
2362 | ||
320ae51f | 2363 | return q; |
18741986 | 2364 | |
320ae51f | 2365 | err_hctxs: |
868f2f0b | 2366 | kfree(q->queue_hw_ctx); |
320ae51f | 2367 | err_percpu: |
868f2f0b | 2368 | free_percpu(q->queue_ctx); |
c7de5726 ML |
2369 | err_exit: |
2370 | q->mq_ops = NULL; | |
320ae51f JA |
2371 | return ERR_PTR(-ENOMEM); |
2372 | } | |
b62c21b7 | 2373 | EXPORT_SYMBOL(blk_mq_init_allocated_queue); |
320ae51f JA |
2374 | |
2375 | void blk_mq_free_queue(struct request_queue *q) | |
2376 | { | |
624dbe47 | 2377 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 2378 | |
0e626368 AM |
2379 | mutex_lock(&all_q_mutex); |
2380 | list_del_init(&q->all_q_node); | |
2381 | mutex_unlock(&all_q_mutex); | |
2382 | ||
87760e5e JA |
2383 | wbt_exit(q); |
2384 | ||
0d2602ca JA |
2385 | blk_mq_del_queue_tag_set(q); |
2386 | ||
624dbe47 ML |
2387 | blk_mq_exit_hw_queues(q, set, set->nr_hw_queues); |
2388 | blk_mq_free_hw_queues(q, set); | |
320ae51f | 2389 | } |
320ae51f JA |
2390 | |
2391 | /* Basically redo blk_mq_init_queue with queue frozen */ | |
5778322e AM |
2392 | static void blk_mq_queue_reinit(struct request_queue *q, |
2393 | const struct cpumask *online_mask) | |
320ae51f | 2394 | { |
4ecd4fef | 2395 | WARN_ON_ONCE(!atomic_read(&q->mq_freeze_depth)); |
320ae51f | 2396 | |
67aec14c JA |
2397 | blk_mq_sysfs_unregister(q); |
2398 | ||
320ae51f JA |
2399 | /* |
2400 | * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe | |
2401 | * we should change hctx numa_node according to new topology (this | |
2402 | * involves free and re-allocate memory, worthy doing?) | |
2403 | */ | |
2404 | ||
5778322e | 2405 | blk_mq_map_swqueue(q, online_mask); |
320ae51f | 2406 | |
67aec14c | 2407 | blk_mq_sysfs_register(q); |
320ae51f JA |
2408 | } |
2409 | ||
65d5291e SAS |
2410 | /* |
2411 | * New online cpumask which is going to be set in this hotplug event. | |
2412 | * Declare this cpumasks as global as cpu-hotplug operation is invoked | |
2413 | * one-by-one and dynamically allocating this could result in a failure. | |
2414 | */ | |
2415 | static struct cpumask cpuhp_online_new; | |
2416 | ||
2417 | static void blk_mq_queue_reinit_work(void) | |
320ae51f JA |
2418 | { |
2419 | struct request_queue *q; | |
320ae51f JA |
2420 | |
2421 | mutex_lock(&all_q_mutex); | |
f3af020b TH |
2422 | /* |
2423 | * We need to freeze and reinit all existing queues. Freezing | |
2424 | * involves synchronous wait for an RCU grace period and doing it | |
2425 | * one by one may take a long time. Start freezing all queues in | |
2426 | * one swoop and then wait for the completions so that freezing can | |
2427 | * take place in parallel. | |
2428 | */ | |
2429 | list_for_each_entry(q, &all_q_list, all_q_node) | |
2430 | blk_mq_freeze_queue_start(q); | |
415d3dab | 2431 | list_for_each_entry(q, &all_q_list, all_q_node) |
f3af020b TH |
2432 | blk_mq_freeze_queue_wait(q); |
2433 | ||
320ae51f | 2434 | list_for_each_entry(q, &all_q_list, all_q_node) |
65d5291e | 2435 | blk_mq_queue_reinit(q, &cpuhp_online_new); |
f3af020b TH |
2436 | |
2437 | list_for_each_entry(q, &all_q_list, all_q_node) | |
2438 | blk_mq_unfreeze_queue(q); | |
2439 | ||
320ae51f | 2440 | mutex_unlock(&all_q_mutex); |
65d5291e SAS |
2441 | } |
2442 | ||
2443 | static int blk_mq_queue_reinit_dead(unsigned int cpu) | |
2444 | { | |
97a32864 | 2445 | cpumask_copy(&cpuhp_online_new, cpu_online_mask); |
65d5291e SAS |
2446 | blk_mq_queue_reinit_work(); |
2447 | return 0; | |
2448 | } | |
2449 | ||
2450 | /* | |
2451 | * Before hotadded cpu starts handling requests, new mappings must be | |
2452 | * established. Otherwise, these requests in hw queue might never be | |
2453 | * dispatched. | |
2454 | * | |
2455 | * For example, there is a single hw queue (hctx) and two CPU queues (ctx0 | |
2456 | * for CPU0, and ctx1 for CPU1). | |
2457 | * | |
2458 | * Now CPU1 is just onlined and a request is inserted into ctx1->rq_list | |
2459 | * and set bit0 in pending bitmap as ctx1->index_hw is still zero. | |
2460 | * | |
2c3ad667 JA |
2461 | * And then while running hw queue, blk_mq_flush_busy_ctxs() finds bit0 is set |
2462 | * in pending bitmap and tries to retrieve requests in hctx->ctxs[0]->rq_list. | |
2463 | * But htx->ctxs[0] is a pointer to ctx0, so the request in ctx1->rq_list is | |
2464 | * ignored. | |
65d5291e SAS |
2465 | */ |
2466 | static int blk_mq_queue_reinit_prepare(unsigned int cpu) | |
2467 | { | |
2468 | cpumask_copy(&cpuhp_online_new, cpu_online_mask); | |
2469 | cpumask_set_cpu(cpu, &cpuhp_online_new); | |
2470 | blk_mq_queue_reinit_work(); | |
2471 | return 0; | |
320ae51f JA |
2472 | } |
2473 | ||
a5164405 JA |
2474 | static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) |
2475 | { | |
2476 | int i; | |
2477 | ||
cc71a6f4 JA |
2478 | for (i = 0; i < set->nr_hw_queues; i++) |
2479 | if (!__blk_mq_alloc_rq_map(set, i)) | |
a5164405 | 2480 | goto out_unwind; |
a5164405 JA |
2481 | |
2482 | return 0; | |
2483 | ||
2484 | out_unwind: | |
2485 | while (--i >= 0) | |
cc71a6f4 | 2486 | blk_mq_free_rq_map(set->tags[i]); |
a5164405 | 2487 | |
a5164405 JA |
2488 | return -ENOMEM; |
2489 | } | |
2490 | ||
2491 | /* | |
2492 | * Allocate the request maps associated with this tag_set. Note that this | |
2493 | * may reduce the depth asked for, if memory is tight. set->queue_depth | |
2494 | * will be updated to reflect the allocated depth. | |
2495 | */ | |
2496 | static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) | |
2497 | { | |
2498 | unsigned int depth; | |
2499 | int err; | |
2500 | ||
2501 | depth = set->queue_depth; | |
2502 | do { | |
2503 | err = __blk_mq_alloc_rq_maps(set); | |
2504 | if (!err) | |
2505 | break; | |
2506 | ||
2507 | set->queue_depth >>= 1; | |
2508 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) { | |
2509 | err = -ENOMEM; | |
2510 | break; | |
2511 | } | |
2512 | } while (set->queue_depth); | |
2513 | ||
2514 | if (!set->queue_depth || err) { | |
2515 | pr_err("blk-mq: failed to allocate request map\n"); | |
2516 | return -ENOMEM; | |
2517 | } | |
2518 | ||
2519 | if (depth != set->queue_depth) | |
2520 | pr_info("blk-mq: reduced tag depth (%u -> %u)\n", | |
2521 | depth, set->queue_depth); | |
2522 | ||
2523 | return 0; | |
2524 | } | |
2525 | ||
a4391c64 JA |
2526 | /* |
2527 | * Alloc a tag set to be associated with one or more request queues. | |
2528 | * May fail with EINVAL for various error conditions. May adjust the | |
2529 | * requested depth down, if if it too large. In that case, the set | |
2530 | * value will be stored in set->queue_depth. | |
2531 | */ | |
24d2f903 CH |
2532 | int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) |
2533 | { | |
da695ba2 CH |
2534 | int ret; |
2535 | ||
205fb5f5 BVA |
2536 | BUILD_BUG_ON(BLK_MQ_MAX_DEPTH > 1 << BLK_MQ_UNIQUE_TAG_BITS); |
2537 | ||
24d2f903 CH |
2538 | if (!set->nr_hw_queues) |
2539 | return -EINVAL; | |
a4391c64 | 2540 | if (!set->queue_depth) |
24d2f903 CH |
2541 | return -EINVAL; |
2542 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) | |
2543 | return -EINVAL; | |
2544 | ||
7d7e0f90 | 2545 | if (!set->ops->queue_rq) |
24d2f903 CH |
2546 | return -EINVAL; |
2547 | ||
a4391c64 JA |
2548 | if (set->queue_depth > BLK_MQ_MAX_DEPTH) { |
2549 | pr_info("blk-mq: reduced tag depth to %u\n", | |
2550 | BLK_MQ_MAX_DEPTH); | |
2551 | set->queue_depth = BLK_MQ_MAX_DEPTH; | |
2552 | } | |
24d2f903 | 2553 | |
6637fadf SL |
2554 | /* |
2555 | * If a crashdump is active, then we are potentially in a very | |
2556 | * memory constrained environment. Limit us to 1 queue and | |
2557 | * 64 tags to prevent using too much memory. | |
2558 | */ | |
2559 | if (is_kdump_kernel()) { | |
2560 | set->nr_hw_queues = 1; | |
2561 | set->queue_depth = min(64U, set->queue_depth); | |
2562 | } | |
868f2f0b KB |
2563 | /* |
2564 | * There is no use for more h/w queues than cpus. | |
2565 | */ | |
2566 | if (set->nr_hw_queues > nr_cpu_ids) | |
2567 | set->nr_hw_queues = nr_cpu_ids; | |
6637fadf | 2568 | |
868f2f0b | 2569 | set->tags = kzalloc_node(nr_cpu_ids * sizeof(struct blk_mq_tags *), |
24d2f903 CH |
2570 | GFP_KERNEL, set->numa_node); |
2571 | if (!set->tags) | |
a5164405 | 2572 | return -ENOMEM; |
24d2f903 | 2573 | |
da695ba2 CH |
2574 | ret = -ENOMEM; |
2575 | set->mq_map = kzalloc_node(sizeof(*set->mq_map) * nr_cpu_ids, | |
2576 | GFP_KERNEL, set->numa_node); | |
bdd17e75 CH |
2577 | if (!set->mq_map) |
2578 | goto out_free_tags; | |
2579 | ||
da695ba2 CH |
2580 | if (set->ops->map_queues) |
2581 | ret = set->ops->map_queues(set); | |
2582 | else | |
2583 | ret = blk_mq_map_queues(set); | |
2584 | if (ret) | |
2585 | goto out_free_mq_map; | |
2586 | ||
2587 | ret = blk_mq_alloc_rq_maps(set); | |
2588 | if (ret) | |
bdd17e75 | 2589 | goto out_free_mq_map; |
24d2f903 | 2590 | |
0d2602ca JA |
2591 | mutex_init(&set->tag_list_lock); |
2592 | INIT_LIST_HEAD(&set->tag_list); | |
2593 | ||
24d2f903 | 2594 | return 0; |
bdd17e75 CH |
2595 | |
2596 | out_free_mq_map: | |
2597 | kfree(set->mq_map); | |
2598 | set->mq_map = NULL; | |
2599 | out_free_tags: | |
5676e7b6 RE |
2600 | kfree(set->tags); |
2601 | set->tags = NULL; | |
da695ba2 | 2602 | return ret; |
24d2f903 CH |
2603 | } |
2604 | EXPORT_SYMBOL(blk_mq_alloc_tag_set); | |
2605 | ||
2606 | void blk_mq_free_tag_set(struct blk_mq_tag_set *set) | |
2607 | { | |
2608 | int i; | |
2609 | ||
cc71a6f4 JA |
2610 | for (i = 0; i < nr_cpu_ids; i++) |
2611 | blk_mq_free_map_and_requests(set, i); | |
484b4061 | 2612 | |
bdd17e75 CH |
2613 | kfree(set->mq_map); |
2614 | set->mq_map = NULL; | |
2615 | ||
981bd189 | 2616 | kfree(set->tags); |
5676e7b6 | 2617 | set->tags = NULL; |
24d2f903 CH |
2618 | } |
2619 | EXPORT_SYMBOL(blk_mq_free_tag_set); | |
2620 | ||
e3a2b3f9 JA |
2621 | int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) |
2622 | { | |
2623 | struct blk_mq_tag_set *set = q->tag_set; | |
2624 | struct blk_mq_hw_ctx *hctx; | |
2625 | int i, ret; | |
2626 | ||
bd166ef1 | 2627 | if (!set) |
e3a2b3f9 JA |
2628 | return -EINVAL; |
2629 | ||
70f36b60 JA |
2630 | blk_mq_freeze_queue(q); |
2631 | blk_mq_quiesce_queue(q); | |
2632 | ||
e3a2b3f9 JA |
2633 | ret = 0; |
2634 | queue_for_each_hw_ctx(q, hctx, i) { | |
e9137d4b KB |
2635 | if (!hctx->tags) |
2636 | continue; | |
bd166ef1 JA |
2637 | /* |
2638 | * If we're using an MQ scheduler, just update the scheduler | |
2639 | * queue depth. This is similar to what the old code would do. | |
2640 | */ | |
70f36b60 JA |
2641 | if (!hctx->sched_tags) { |
2642 | ret = blk_mq_tag_update_depth(hctx, &hctx->tags, | |
2643 | min(nr, set->queue_depth), | |
2644 | false); | |
2645 | } else { | |
2646 | ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags, | |
2647 | nr, true); | |
2648 | } | |
e3a2b3f9 JA |
2649 | if (ret) |
2650 | break; | |
2651 | } | |
2652 | ||
2653 | if (!ret) | |
2654 | q->nr_requests = nr; | |
2655 | ||
70f36b60 JA |
2656 | blk_mq_unfreeze_queue(q); |
2657 | blk_mq_start_stopped_hw_queues(q, true); | |
2658 | ||
e3a2b3f9 JA |
2659 | return ret; |
2660 | } | |
2661 | ||
868f2f0b KB |
2662 | void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues) |
2663 | { | |
2664 | struct request_queue *q; | |
2665 | ||
2666 | if (nr_hw_queues > nr_cpu_ids) | |
2667 | nr_hw_queues = nr_cpu_ids; | |
2668 | if (nr_hw_queues < 1 || nr_hw_queues == set->nr_hw_queues) | |
2669 | return; | |
2670 | ||
2671 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
2672 | blk_mq_freeze_queue(q); | |
2673 | ||
2674 | set->nr_hw_queues = nr_hw_queues; | |
2675 | list_for_each_entry(q, &set->tag_list, tag_set_list) { | |
2676 | blk_mq_realloc_hw_ctxs(set, q); | |
2677 | ||
f6f94300 JB |
2678 | /* |
2679 | * Manually set the make_request_fn as blk_queue_make_request | |
2680 | * resets a lot of the queue settings. | |
2681 | */ | |
868f2f0b | 2682 | if (q->nr_hw_queues > 1) |
f6f94300 | 2683 | q->make_request_fn = blk_mq_make_request; |
868f2f0b | 2684 | else |
f6f94300 | 2685 | q->make_request_fn = blk_sq_make_request; |
868f2f0b KB |
2686 | |
2687 | blk_mq_queue_reinit(q, cpu_online_mask); | |
2688 | } | |
2689 | ||
2690 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
2691 | blk_mq_unfreeze_queue(q); | |
2692 | } | |
2693 | EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues); | |
2694 | ||
64f1c21e JA |
2695 | static unsigned long blk_mq_poll_nsecs(struct request_queue *q, |
2696 | struct blk_mq_hw_ctx *hctx, | |
2697 | struct request *rq) | |
2698 | { | |
2699 | struct blk_rq_stat stat[2]; | |
2700 | unsigned long ret = 0; | |
2701 | ||
2702 | /* | |
2703 | * If stats collection isn't on, don't sleep but turn it on for | |
2704 | * future users | |
2705 | */ | |
2706 | if (!blk_stat_enable(q)) | |
2707 | return 0; | |
2708 | ||
2709 | /* | |
2710 | * We don't have to do this once per IO, should optimize this | |
2711 | * to just use the current window of stats until it changes | |
2712 | */ | |
2713 | memset(&stat, 0, sizeof(stat)); | |
2714 | blk_hctx_stat_get(hctx, stat); | |
2715 | ||
2716 | /* | |
2717 | * As an optimistic guess, use half of the mean service time | |
2718 | * for this type of request. We can (and should) make this smarter. | |
2719 | * For instance, if the completion latencies are tight, we can | |
2720 | * get closer than just half the mean. This is especially | |
2721 | * important on devices where the completion latencies are longer | |
2722 | * than ~10 usec. | |
2723 | */ | |
2724 | if (req_op(rq) == REQ_OP_READ && stat[BLK_STAT_READ].nr_samples) | |
2725 | ret = (stat[BLK_STAT_READ].mean + 1) / 2; | |
2726 | else if (req_op(rq) == REQ_OP_WRITE && stat[BLK_STAT_WRITE].nr_samples) | |
2727 | ret = (stat[BLK_STAT_WRITE].mean + 1) / 2; | |
2728 | ||
2729 | return ret; | |
2730 | } | |
2731 | ||
06426adf | 2732 | static bool blk_mq_poll_hybrid_sleep(struct request_queue *q, |
64f1c21e | 2733 | struct blk_mq_hw_ctx *hctx, |
06426adf JA |
2734 | struct request *rq) |
2735 | { | |
2736 | struct hrtimer_sleeper hs; | |
2737 | enum hrtimer_mode mode; | |
64f1c21e | 2738 | unsigned int nsecs; |
06426adf JA |
2739 | ktime_t kt; |
2740 | ||
64f1c21e JA |
2741 | if (test_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags)) |
2742 | return false; | |
2743 | ||
2744 | /* | |
2745 | * poll_nsec can be: | |
2746 | * | |
2747 | * -1: don't ever hybrid sleep | |
2748 | * 0: use half of prev avg | |
2749 | * >0: use this specific value | |
2750 | */ | |
2751 | if (q->poll_nsec == -1) | |
2752 | return false; | |
2753 | else if (q->poll_nsec > 0) | |
2754 | nsecs = q->poll_nsec; | |
2755 | else | |
2756 | nsecs = blk_mq_poll_nsecs(q, hctx, rq); | |
2757 | ||
2758 | if (!nsecs) | |
06426adf JA |
2759 | return false; |
2760 | ||
2761 | set_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags); | |
2762 | ||
2763 | /* | |
2764 | * This will be replaced with the stats tracking code, using | |
2765 | * 'avg_completion_time / 2' as the pre-sleep target. | |
2766 | */ | |
8b0e1953 | 2767 | kt = nsecs; |
06426adf JA |
2768 | |
2769 | mode = HRTIMER_MODE_REL; | |
2770 | hrtimer_init_on_stack(&hs.timer, CLOCK_MONOTONIC, mode); | |
2771 | hrtimer_set_expires(&hs.timer, kt); | |
2772 | ||
2773 | hrtimer_init_sleeper(&hs, current); | |
2774 | do { | |
2775 | if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) | |
2776 | break; | |
2777 | set_current_state(TASK_UNINTERRUPTIBLE); | |
2778 | hrtimer_start_expires(&hs.timer, mode); | |
2779 | if (hs.task) | |
2780 | io_schedule(); | |
2781 | hrtimer_cancel(&hs.timer); | |
2782 | mode = HRTIMER_MODE_ABS; | |
2783 | } while (hs.task && !signal_pending(current)); | |
2784 | ||
2785 | __set_current_state(TASK_RUNNING); | |
2786 | destroy_hrtimer_on_stack(&hs.timer); | |
2787 | return true; | |
2788 | } | |
2789 | ||
bbd7bb70 JA |
2790 | static bool __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq) |
2791 | { | |
2792 | struct request_queue *q = hctx->queue; | |
2793 | long state; | |
2794 | ||
06426adf JA |
2795 | /* |
2796 | * If we sleep, have the caller restart the poll loop to reset | |
2797 | * the state. Like for the other success return cases, the | |
2798 | * caller is responsible for checking if the IO completed. If | |
2799 | * the IO isn't complete, we'll get called again and will go | |
2800 | * straight to the busy poll loop. | |
2801 | */ | |
64f1c21e | 2802 | if (blk_mq_poll_hybrid_sleep(q, hctx, rq)) |
06426adf JA |
2803 | return true; |
2804 | ||
bbd7bb70 JA |
2805 | hctx->poll_considered++; |
2806 | ||
2807 | state = current->state; | |
2808 | while (!need_resched()) { | |
2809 | int ret; | |
2810 | ||
2811 | hctx->poll_invoked++; | |
2812 | ||
2813 | ret = q->mq_ops->poll(hctx, rq->tag); | |
2814 | if (ret > 0) { | |
2815 | hctx->poll_success++; | |
2816 | set_current_state(TASK_RUNNING); | |
2817 | return true; | |
2818 | } | |
2819 | ||
2820 | if (signal_pending_state(state, current)) | |
2821 | set_current_state(TASK_RUNNING); | |
2822 | ||
2823 | if (current->state == TASK_RUNNING) | |
2824 | return true; | |
2825 | if (ret < 0) | |
2826 | break; | |
2827 | cpu_relax(); | |
2828 | } | |
2829 | ||
2830 | return false; | |
2831 | } | |
2832 | ||
2833 | bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie) | |
2834 | { | |
2835 | struct blk_mq_hw_ctx *hctx; | |
2836 | struct blk_plug *plug; | |
2837 | struct request *rq; | |
2838 | ||
2839 | if (!q->mq_ops || !q->mq_ops->poll || !blk_qc_t_valid(cookie) || | |
2840 | !test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) | |
2841 | return false; | |
2842 | ||
2843 | plug = current->plug; | |
2844 | if (plug) | |
2845 | blk_flush_plug_list(plug, false); | |
2846 | ||
2847 | hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)]; | |
bd166ef1 JA |
2848 | if (!blk_qc_t_is_internal(cookie)) |
2849 | rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie)); | |
2850 | else | |
2851 | rq = blk_mq_tag_to_rq(hctx->sched_tags, blk_qc_t_to_tag(cookie)); | |
bbd7bb70 JA |
2852 | |
2853 | return __blk_mq_poll(hctx, rq); | |
2854 | } | |
2855 | EXPORT_SYMBOL_GPL(blk_mq_poll); | |
2856 | ||
676141e4 JA |
2857 | void blk_mq_disable_hotplug(void) |
2858 | { | |
2859 | mutex_lock(&all_q_mutex); | |
2860 | } | |
2861 | ||
2862 | void blk_mq_enable_hotplug(void) | |
2863 | { | |
2864 | mutex_unlock(&all_q_mutex); | |
2865 | } | |
2866 | ||
320ae51f JA |
2867 | static int __init blk_mq_init(void) |
2868 | { | |
9467f859 TG |
2869 | cpuhp_setup_state_multi(CPUHP_BLK_MQ_DEAD, "block/mq:dead", NULL, |
2870 | blk_mq_hctx_notify_dead); | |
320ae51f | 2871 | |
65d5291e SAS |
2872 | cpuhp_setup_state_nocalls(CPUHP_BLK_MQ_PREPARE, "block/mq:prepare", |
2873 | blk_mq_queue_reinit_prepare, | |
2874 | blk_mq_queue_reinit_dead); | |
320ae51f JA |
2875 | return 0; |
2876 | } | |
2877 | subsys_initcall(blk_mq_init); |