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Commit | Line | Data |
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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> | |
23 | #include <linux/delay.h> | |
aedcd72f | 24 | #include <linux/crash_dump.h> |
88c7b2b7 | 25 | #include <linux/prefetch.h> |
320ae51f JA |
26 | |
27 | #include <trace/events/block.h> | |
28 | ||
29 | #include <linux/blk-mq.h> | |
30 | #include "blk.h" | |
31 | #include "blk-mq.h" | |
32 | #include "blk-mq-tag.h" | |
cf43e6be | 33 | #include "blk-stat.h" |
87760e5e | 34 | #include "blk-wbt.h" |
320ae51f JA |
35 | |
36 | static DEFINE_MUTEX(all_q_mutex); | |
37 | static LIST_HEAD(all_q_list); | |
38 | ||
320ae51f JA |
39 | /* |
40 | * Check if any of the ctx's have pending work in this hardware queue | |
41 | */ | |
42 | static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx) | |
43 | { | |
88459642 | 44 | return sbitmap_any_bit_set(&hctx->ctx_map); |
1429d7c9 JA |
45 | } |
46 | ||
320ae51f JA |
47 | /* |
48 | * Mark this ctx as having pending work in this hardware queue | |
49 | */ | |
50 | static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx, | |
51 | struct blk_mq_ctx *ctx) | |
52 | { | |
88459642 OS |
53 | if (!sbitmap_test_bit(&hctx->ctx_map, ctx->index_hw)) |
54 | sbitmap_set_bit(&hctx->ctx_map, ctx->index_hw); | |
1429d7c9 JA |
55 | } |
56 | ||
57 | static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx, | |
58 | struct blk_mq_ctx *ctx) | |
59 | { | |
88459642 | 60 | sbitmap_clear_bit(&hctx->ctx_map, ctx->index_hw); |
320ae51f JA |
61 | } |
62 | ||
b4c6a028 | 63 | void blk_mq_freeze_queue_start(struct request_queue *q) |
43a5e4e2 | 64 | { |
4ecd4fef | 65 | int freeze_depth; |
cddd5d17 | 66 | |
4ecd4fef CH |
67 | freeze_depth = atomic_inc_return(&q->mq_freeze_depth); |
68 | if (freeze_depth == 1) { | |
3ef28e83 | 69 | percpu_ref_kill(&q->q_usage_counter); |
b94ec296 | 70 | blk_mq_run_hw_queues(q, false); |
cddd5d17 | 71 | } |
f3af020b | 72 | } |
b4c6a028 | 73 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_start); |
f3af020b TH |
74 | |
75 | static void blk_mq_freeze_queue_wait(struct request_queue *q) | |
76 | { | |
3ef28e83 | 77 | wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter)); |
43a5e4e2 ML |
78 | } |
79 | ||
f3af020b TH |
80 | /* |
81 | * Guarantee no request is in use, so we can change any data structure of | |
82 | * the queue afterward. | |
83 | */ | |
3ef28e83 | 84 | void blk_freeze_queue(struct request_queue *q) |
f3af020b | 85 | { |
3ef28e83 DW |
86 | /* |
87 | * In the !blk_mq case we are only calling this to kill the | |
88 | * q_usage_counter, otherwise this increases the freeze depth | |
89 | * and waits for it to return to zero. For this reason there is | |
90 | * no blk_unfreeze_queue(), and blk_freeze_queue() is not | |
91 | * exported to drivers as the only user for unfreeze is blk_mq. | |
92 | */ | |
f3af020b TH |
93 | blk_mq_freeze_queue_start(q); |
94 | blk_mq_freeze_queue_wait(q); | |
95 | } | |
3ef28e83 DW |
96 | |
97 | void blk_mq_freeze_queue(struct request_queue *q) | |
98 | { | |
99 | /* | |
100 | * ...just an alias to keep freeze and unfreeze actions balanced | |
101 | * in the blk_mq_* namespace | |
102 | */ | |
103 | blk_freeze_queue(q); | |
104 | } | |
c761d96b | 105 | EXPORT_SYMBOL_GPL(blk_mq_freeze_queue); |
f3af020b | 106 | |
b4c6a028 | 107 | void blk_mq_unfreeze_queue(struct request_queue *q) |
320ae51f | 108 | { |
4ecd4fef | 109 | int freeze_depth; |
320ae51f | 110 | |
4ecd4fef CH |
111 | freeze_depth = atomic_dec_return(&q->mq_freeze_depth); |
112 | WARN_ON_ONCE(freeze_depth < 0); | |
113 | if (!freeze_depth) { | |
3ef28e83 | 114 | percpu_ref_reinit(&q->q_usage_counter); |
320ae51f | 115 | wake_up_all(&q->mq_freeze_wq); |
add703fd | 116 | } |
320ae51f | 117 | } |
b4c6a028 | 118 | EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue); |
320ae51f | 119 | |
6a83e74d BVA |
120 | /** |
121 | * blk_mq_quiesce_queue() - wait until all ongoing queue_rq calls have finished | |
122 | * @q: request queue. | |
123 | * | |
124 | * Note: this function does not prevent that the struct request end_io() | |
125 | * callback function is invoked. Additionally, it is not prevented that | |
126 | * new queue_rq() calls occur unless the queue has been stopped first. | |
127 | */ | |
128 | void blk_mq_quiesce_queue(struct request_queue *q) | |
129 | { | |
130 | struct blk_mq_hw_ctx *hctx; | |
131 | unsigned int i; | |
132 | bool rcu = false; | |
133 | ||
134 | blk_mq_stop_hw_queues(q); | |
135 | ||
136 | queue_for_each_hw_ctx(q, hctx, i) { | |
137 | if (hctx->flags & BLK_MQ_F_BLOCKING) | |
138 | synchronize_srcu(&hctx->queue_rq_srcu); | |
139 | else | |
140 | rcu = true; | |
141 | } | |
142 | if (rcu) | |
143 | synchronize_rcu(); | |
144 | } | |
145 | EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue); | |
146 | ||
aed3ea94 JA |
147 | void blk_mq_wake_waiters(struct request_queue *q) |
148 | { | |
149 | struct blk_mq_hw_ctx *hctx; | |
150 | unsigned int i; | |
151 | ||
152 | queue_for_each_hw_ctx(q, hctx, i) | |
153 | if (blk_mq_hw_queue_mapped(hctx)) | |
154 | blk_mq_tag_wakeup_all(hctx->tags, true); | |
3fd5940c KB |
155 | |
156 | /* | |
157 | * If we are called because the queue has now been marked as | |
158 | * dying, we need to ensure that processes currently waiting on | |
159 | * the queue are notified as well. | |
160 | */ | |
161 | wake_up_all(&q->mq_freeze_wq); | |
aed3ea94 JA |
162 | } |
163 | ||
320ae51f JA |
164 | bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx) |
165 | { | |
166 | return blk_mq_has_free_tags(hctx->tags); | |
167 | } | |
168 | EXPORT_SYMBOL(blk_mq_can_queue); | |
169 | ||
94eddfbe | 170 | static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx, |
ef295ecf | 171 | struct request *rq, unsigned int op) |
320ae51f | 172 | { |
af76e555 CH |
173 | INIT_LIST_HEAD(&rq->queuelist); |
174 | /* csd/requeue_work/fifo_time is initialized before use */ | |
175 | rq->q = q; | |
320ae51f | 176 | rq->mq_ctx = ctx; |
ef295ecf | 177 | rq->cmd_flags = op; |
e8064021 CH |
178 | if (blk_queue_io_stat(q)) |
179 | rq->rq_flags |= RQF_IO_STAT; | |
af76e555 CH |
180 | /* do not touch atomic flags, it needs atomic ops against the timer */ |
181 | rq->cpu = -1; | |
af76e555 CH |
182 | INIT_HLIST_NODE(&rq->hash); |
183 | RB_CLEAR_NODE(&rq->rb_node); | |
af76e555 CH |
184 | rq->rq_disk = NULL; |
185 | rq->part = NULL; | |
3ee32372 | 186 | rq->start_time = jiffies; |
af76e555 CH |
187 | #ifdef CONFIG_BLK_CGROUP |
188 | rq->rl = NULL; | |
0fec08b4 | 189 | set_start_time_ns(rq); |
af76e555 CH |
190 | rq->io_start_time_ns = 0; |
191 | #endif | |
192 | rq->nr_phys_segments = 0; | |
193 | #if defined(CONFIG_BLK_DEV_INTEGRITY) | |
194 | rq->nr_integrity_segments = 0; | |
195 | #endif | |
af76e555 CH |
196 | rq->special = NULL; |
197 | /* tag was already set */ | |
198 | rq->errors = 0; | |
af76e555 | 199 | |
6f4a1626 TB |
200 | rq->cmd = rq->__cmd; |
201 | ||
af76e555 CH |
202 | rq->extra_len = 0; |
203 | rq->sense_len = 0; | |
204 | rq->resid_len = 0; | |
205 | rq->sense = NULL; | |
206 | ||
af76e555 | 207 | INIT_LIST_HEAD(&rq->timeout_list); |
f6be4fb4 JA |
208 | rq->timeout = 0; |
209 | ||
af76e555 CH |
210 | rq->end_io = NULL; |
211 | rq->end_io_data = NULL; | |
212 | rq->next_rq = NULL; | |
213 | ||
ef295ecf | 214 | ctx->rq_dispatched[op_is_sync(op)]++; |
320ae51f JA |
215 | } |
216 | ||
5dee8577 | 217 | static struct request * |
ef295ecf | 218 | __blk_mq_alloc_request(struct blk_mq_alloc_data *data, unsigned int op) |
5dee8577 CH |
219 | { |
220 | struct request *rq; | |
221 | unsigned int tag; | |
222 | ||
cb96a42c | 223 | tag = blk_mq_get_tag(data); |
5dee8577 | 224 | if (tag != BLK_MQ_TAG_FAIL) { |
cb96a42c | 225 | rq = data->hctx->tags->rqs[tag]; |
5dee8577 | 226 | |
cb96a42c | 227 | if (blk_mq_tag_busy(data->hctx)) { |
e8064021 | 228 | rq->rq_flags = RQF_MQ_INFLIGHT; |
cb96a42c | 229 | atomic_inc(&data->hctx->nr_active); |
5dee8577 CH |
230 | } |
231 | ||
232 | rq->tag = tag; | |
ef295ecf | 233 | blk_mq_rq_ctx_init(data->q, data->ctx, rq, op); |
5dee8577 CH |
234 | return rq; |
235 | } | |
236 | ||
237 | return NULL; | |
238 | } | |
239 | ||
6f3b0e8b CH |
240 | struct request *blk_mq_alloc_request(struct request_queue *q, int rw, |
241 | unsigned int flags) | |
320ae51f | 242 | { |
d852564f CH |
243 | struct blk_mq_ctx *ctx; |
244 | struct blk_mq_hw_ctx *hctx; | |
320ae51f | 245 | struct request *rq; |
cb96a42c | 246 | struct blk_mq_alloc_data alloc_data; |
a492f075 | 247 | int ret; |
320ae51f | 248 | |
6f3b0e8b | 249 | ret = blk_queue_enter(q, flags & BLK_MQ_REQ_NOWAIT); |
a492f075 JL |
250 | if (ret) |
251 | return ERR_PTR(ret); | |
320ae51f | 252 | |
d852564f | 253 | ctx = blk_mq_get_ctx(q); |
7d7e0f90 | 254 | hctx = blk_mq_map_queue(q, ctx->cpu); |
6f3b0e8b | 255 | blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx); |
ef295ecf | 256 | rq = __blk_mq_alloc_request(&alloc_data, rw); |
d852564f | 257 | blk_mq_put_ctx(ctx); |
841bac2c | 258 | |
c76541a9 | 259 | if (!rq) { |
3ef28e83 | 260 | blk_queue_exit(q); |
a492f075 | 261 | return ERR_PTR(-EWOULDBLOCK); |
c76541a9 | 262 | } |
0c4de0f3 CH |
263 | |
264 | rq->__data_len = 0; | |
265 | rq->__sector = (sector_t) -1; | |
266 | rq->bio = rq->biotail = NULL; | |
320ae51f JA |
267 | return rq; |
268 | } | |
4bb659b1 | 269 | EXPORT_SYMBOL(blk_mq_alloc_request); |
320ae51f | 270 | |
1f5bd336 ML |
271 | struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int rw, |
272 | unsigned int flags, unsigned int hctx_idx) | |
273 | { | |
274 | struct blk_mq_hw_ctx *hctx; | |
275 | struct blk_mq_ctx *ctx; | |
276 | struct request *rq; | |
277 | struct blk_mq_alloc_data alloc_data; | |
278 | int ret; | |
279 | ||
280 | /* | |
281 | * If the tag allocator sleeps we could get an allocation for a | |
282 | * different hardware context. No need to complicate the low level | |
283 | * allocator for this for the rare use case of a command tied to | |
284 | * a specific queue. | |
285 | */ | |
286 | if (WARN_ON_ONCE(!(flags & BLK_MQ_REQ_NOWAIT))) | |
287 | return ERR_PTR(-EINVAL); | |
288 | ||
289 | if (hctx_idx >= q->nr_hw_queues) | |
290 | return ERR_PTR(-EIO); | |
291 | ||
292 | ret = blk_queue_enter(q, true); | |
293 | if (ret) | |
294 | return ERR_PTR(ret); | |
295 | ||
c8712c6a CH |
296 | /* |
297 | * Check if the hardware context is actually mapped to anything. | |
298 | * If not tell the caller that it should skip this queue. | |
299 | */ | |
1f5bd336 | 300 | hctx = q->queue_hw_ctx[hctx_idx]; |
c8712c6a CH |
301 | if (!blk_mq_hw_queue_mapped(hctx)) { |
302 | ret = -EXDEV; | |
303 | goto out_queue_exit; | |
304 | } | |
1f5bd336 ML |
305 | ctx = __blk_mq_get_ctx(q, cpumask_first(hctx->cpumask)); |
306 | ||
307 | blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx); | |
ef295ecf | 308 | rq = __blk_mq_alloc_request(&alloc_data, rw); |
1f5bd336 | 309 | if (!rq) { |
c8712c6a CH |
310 | ret = -EWOULDBLOCK; |
311 | goto out_queue_exit; | |
1f5bd336 ML |
312 | } |
313 | ||
314 | return rq; | |
c8712c6a CH |
315 | |
316 | out_queue_exit: | |
317 | blk_queue_exit(q); | |
318 | return ERR_PTR(ret); | |
1f5bd336 ML |
319 | } |
320 | EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx); | |
321 | ||
320ae51f JA |
322 | static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, |
323 | struct blk_mq_ctx *ctx, struct request *rq) | |
324 | { | |
325 | const int tag = rq->tag; | |
326 | struct request_queue *q = rq->q; | |
327 | ||
e8064021 | 328 | if (rq->rq_flags & RQF_MQ_INFLIGHT) |
0d2602ca | 329 | atomic_dec(&hctx->nr_active); |
87760e5e JA |
330 | |
331 | wbt_done(q->rq_wb, &rq->issue_stat); | |
e8064021 | 332 | rq->rq_flags = 0; |
0d2602ca | 333 | |
af76e555 | 334 | clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags); |
06426adf | 335 | clear_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags); |
40aabb67 | 336 | blk_mq_put_tag(hctx, ctx, tag); |
3ef28e83 | 337 | blk_queue_exit(q); |
320ae51f JA |
338 | } |
339 | ||
7c7f2f2b | 340 | void blk_mq_free_hctx_request(struct blk_mq_hw_ctx *hctx, struct request *rq) |
320ae51f JA |
341 | { |
342 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
320ae51f JA |
343 | |
344 | ctx->rq_completed[rq_is_sync(rq)]++; | |
320ae51f | 345 | __blk_mq_free_request(hctx, ctx, rq); |
7c7f2f2b JA |
346 | |
347 | } | |
348 | EXPORT_SYMBOL_GPL(blk_mq_free_hctx_request); | |
349 | ||
350 | void blk_mq_free_request(struct request *rq) | |
351 | { | |
7d7e0f90 | 352 | blk_mq_free_hctx_request(blk_mq_map_queue(rq->q, rq->mq_ctx->cpu), rq); |
320ae51f | 353 | } |
1a3b595a | 354 | EXPORT_SYMBOL_GPL(blk_mq_free_request); |
320ae51f | 355 | |
c8a446ad | 356 | inline void __blk_mq_end_request(struct request *rq, int error) |
320ae51f | 357 | { |
0d11e6ac ML |
358 | blk_account_io_done(rq); |
359 | ||
91b63639 | 360 | if (rq->end_io) { |
87760e5e | 361 | wbt_done(rq->q->rq_wb, &rq->issue_stat); |
320ae51f | 362 | rq->end_io(rq, error); |
91b63639 CH |
363 | } else { |
364 | if (unlikely(blk_bidi_rq(rq))) | |
365 | blk_mq_free_request(rq->next_rq); | |
320ae51f | 366 | blk_mq_free_request(rq); |
91b63639 | 367 | } |
320ae51f | 368 | } |
c8a446ad | 369 | EXPORT_SYMBOL(__blk_mq_end_request); |
63151a44 | 370 | |
c8a446ad | 371 | void blk_mq_end_request(struct request *rq, int error) |
63151a44 CH |
372 | { |
373 | if (blk_update_request(rq, error, blk_rq_bytes(rq))) | |
374 | BUG(); | |
c8a446ad | 375 | __blk_mq_end_request(rq, error); |
63151a44 | 376 | } |
c8a446ad | 377 | EXPORT_SYMBOL(blk_mq_end_request); |
320ae51f | 378 | |
30a91cb4 | 379 | static void __blk_mq_complete_request_remote(void *data) |
320ae51f | 380 | { |
3d6efbf6 | 381 | struct request *rq = data; |
320ae51f | 382 | |
30a91cb4 | 383 | rq->q->softirq_done_fn(rq); |
320ae51f | 384 | } |
320ae51f | 385 | |
ed851860 | 386 | static void blk_mq_ipi_complete_request(struct request *rq) |
320ae51f JA |
387 | { |
388 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
38535201 | 389 | bool shared = false; |
320ae51f JA |
390 | int cpu; |
391 | ||
38535201 | 392 | if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) { |
30a91cb4 CH |
393 | rq->q->softirq_done_fn(rq); |
394 | return; | |
395 | } | |
320ae51f JA |
396 | |
397 | cpu = get_cpu(); | |
38535201 CH |
398 | if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags)) |
399 | shared = cpus_share_cache(cpu, ctx->cpu); | |
400 | ||
401 | if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) { | |
30a91cb4 | 402 | rq->csd.func = __blk_mq_complete_request_remote; |
3d6efbf6 CH |
403 | rq->csd.info = rq; |
404 | rq->csd.flags = 0; | |
c46fff2a | 405 | smp_call_function_single_async(ctx->cpu, &rq->csd); |
3d6efbf6 | 406 | } else { |
30a91cb4 | 407 | rq->q->softirq_done_fn(rq); |
3d6efbf6 | 408 | } |
320ae51f JA |
409 | put_cpu(); |
410 | } | |
30a91cb4 | 411 | |
cf43e6be JA |
412 | static void blk_mq_stat_add(struct request *rq) |
413 | { | |
414 | if (rq->rq_flags & RQF_STATS) { | |
415 | /* | |
416 | * We could rq->mq_ctx here, but there's less of a risk | |
417 | * of races if we have the completion event add the stats | |
418 | * to the local software queue. | |
419 | */ | |
420 | struct blk_mq_ctx *ctx; | |
421 | ||
422 | ctx = __blk_mq_get_ctx(rq->q, raw_smp_processor_id()); | |
423 | blk_stat_add(&ctx->stat[rq_data_dir(rq)], rq); | |
424 | } | |
425 | } | |
426 | ||
1fa8cc52 | 427 | static void __blk_mq_complete_request(struct request *rq) |
ed851860 JA |
428 | { |
429 | struct request_queue *q = rq->q; | |
430 | ||
cf43e6be JA |
431 | blk_mq_stat_add(rq); |
432 | ||
ed851860 | 433 | if (!q->softirq_done_fn) |
c8a446ad | 434 | blk_mq_end_request(rq, rq->errors); |
ed851860 JA |
435 | else |
436 | blk_mq_ipi_complete_request(rq); | |
437 | } | |
438 | ||
30a91cb4 CH |
439 | /** |
440 | * blk_mq_complete_request - end I/O on a request | |
441 | * @rq: the request being processed | |
442 | * | |
443 | * Description: | |
444 | * Ends all I/O on a request. It does not handle partial completions. | |
445 | * The actual completion happens out-of-order, through a IPI handler. | |
446 | **/ | |
f4829a9b | 447 | void blk_mq_complete_request(struct request *rq, int error) |
30a91cb4 | 448 | { |
95f09684 JA |
449 | struct request_queue *q = rq->q; |
450 | ||
451 | if (unlikely(blk_should_fake_timeout(q))) | |
30a91cb4 | 452 | return; |
f4829a9b CH |
453 | if (!blk_mark_rq_complete(rq)) { |
454 | rq->errors = error; | |
ed851860 | 455 | __blk_mq_complete_request(rq); |
f4829a9b | 456 | } |
30a91cb4 CH |
457 | } |
458 | EXPORT_SYMBOL(blk_mq_complete_request); | |
320ae51f | 459 | |
973c0191 KB |
460 | int blk_mq_request_started(struct request *rq) |
461 | { | |
462 | return test_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
463 | } | |
464 | EXPORT_SYMBOL_GPL(blk_mq_request_started); | |
465 | ||
e2490073 | 466 | void blk_mq_start_request(struct request *rq) |
320ae51f JA |
467 | { |
468 | struct request_queue *q = rq->q; | |
469 | ||
470 | trace_block_rq_issue(q, rq); | |
471 | ||
742ee69b | 472 | rq->resid_len = blk_rq_bytes(rq); |
91b63639 CH |
473 | if (unlikely(blk_bidi_rq(rq))) |
474 | rq->next_rq->resid_len = blk_rq_bytes(rq->next_rq); | |
742ee69b | 475 | |
cf43e6be JA |
476 | if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags)) { |
477 | blk_stat_set_issue_time(&rq->issue_stat); | |
478 | rq->rq_flags |= RQF_STATS; | |
87760e5e | 479 | wbt_issue(q->rq_wb, &rq->issue_stat); |
cf43e6be JA |
480 | } |
481 | ||
2b8393b4 | 482 | blk_add_timer(rq); |
87ee7b11 | 483 | |
538b7534 JA |
484 | /* |
485 | * Ensure that ->deadline is visible before set the started | |
486 | * flag and clear the completed flag. | |
487 | */ | |
488 | smp_mb__before_atomic(); | |
489 | ||
87ee7b11 JA |
490 | /* |
491 | * Mark us as started and clear complete. Complete might have been | |
492 | * set if requeue raced with timeout, which then marked it as | |
493 | * complete. So be sure to clear complete again when we start | |
494 | * the request, otherwise we'll ignore the completion event. | |
495 | */ | |
4b570521 JA |
496 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) |
497 | set_bit(REQ_ATOM_STARTED, &rq->atomic_flags); | |
498 | if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) | |
499 | clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); | |
49f5baa5 CH |
500 | |
501 | if (q->dma_drain_size && blk_rq_bytes(rq)) { | |
502 | /* | |
503 | * Make sure space for the drain appears. We know we can do | |
504 | * this because max_hw_segments has been adjusted to be one | |
505 | * fewer than the device can handle. | |
506 | */ | |
507 | rq->nr_phys_segments++; | |
508 | } | |
320ae51f | 509 | } |
e2490073 | 510 | EXPORT_SYMBOL(blk_mq_start_request); |
320ae51f | 511 | |
ed0791b2 | 512 | static void __blk_mq_requeue_request(struct request *rq) |
320ae51f JA |
513 | { |
514 | struct request_queue *q = rq->q; | |
515 | ||
516 | trace_block_rq_requeue(q, rq); | |
87760e5e | 517 | wbt_requeue(q->rq_wb, &rq->issue_stat); |
49f5baa5 | 518 | |
e2490073 CH |
519 | if (test_and_clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) { |
520 | if (q->dma_drain_size && blk_rq_bytes(rq)) | |
521 | rq->nr_phys_segments--; | |
522 | } | |
320ae51f JA |
523 | } |
524 | ||
2b053aca | 525 | void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list) |
ed0791b2 | 526 | { |
ed0791b2 | 527 | __blk_mq_requeue_request(rq); |
ed0791b2 | 528 | |
ed0791b2 | 529 | BUG_ON(blk_queued_rq(rq)); |
2b053aca | 530 | blk_mq_add_to_requeue_list(rq, true, kick_requeue_list); |
ed0791b2 CH |
531 | } |
532 | EXPORT_SYMBOL(blk_mq_requeue_request); | |
533 | ||
6fca6a61 CH |
534 | static void blk_mq_requeue_work(struct work_struct *work) |
535 | { | |
536 | struct request_queue *q = | |
2849450a | 537 | container_of(work, struct request_queue, requeue_work.work); |
6fca6a61 CH |
538 | LIST_HEAD(rq_list); |
539 | struct request *rq, *next; | |
540 | unsigned long flags; | |
541 | ||
542 | spin_lock_irqsave(&q->requeue_lock, flags); | |
543 | list_splice_init(&q->requeue_list, &rq_list); | |
544 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
545 | ||
546 | list_for_each_entry_safe(rq, next, &rq_list, queuelist) { | |
e8064021 | 547 | if (!(rq->rq_flags & RQF_SOFTBARRIER)) |
6fca6a61 CH |
548 | continue; |
549 | ||
e8064021 | 550 | rq->rq_flags &= ~RQF_SOFTBARRIER; |
6fca6a61 CH |
551 | list_del_init(&rq->queuelist); |
552 | blk_mq_insert_request(rq, true, false, false); | |
553 | } | |
554 | ||
555 | while (!list_empty(&rq_list)) { | |
556 | rq = list_entry(rq_list.next, struct request, queuelist); | |
557 | list_del_init(&rq->queuelist); | |
558 | blk_mq_insert_request(rq, false, false, false); | |
559 | } | |
560 | ||
52d7f1b5 | 561 | blk_mq_run_hw_queues(q, false); |
6fca6a61 CH |
562 | } |
563 | ||
2b053aca BVA |
564 | void blk_mq_add_to_requeue_list(struct request *rq, bool at_head, |
565 | bool kick_requeue_list) | |
6fca6a61 CH |
566 | { |
567 | struct request_queue *q = rq->q; | |
568 | unsigned long flags; | |
569 | ||
570 | /* | |
571 | * We abuse this flag that is otherwise used by the I/O scheduler to | |
572 | * request head insertation from the workqueue. | |
573 | */ | |
e8064021 | 574 | BUG_ON(rq->rq_flags & RQF_SOFTBARRIER); |
6fca6a61 CH |
575 | |
576 | spin_lock_irqsave(&q->requeue_lock, flags); | |
577 | if (at_head) { | |
e8064021 | 578 | rq->rq_flags |= RQF_SOFTBARRIER; |
6fca6a61 CH |
579 | list_add(&rq->queuelist, &q->requeue_list); |
580 | } else { | |
581 | list_add_tail(&rq->queuelist, &q->requeue_list); | |
582 | } | |
583 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
2b053aca BVA |
584 | |
585 | if (kick_requeue_list) | |
586 | blk_mq_kick_requeue_list(q); | |
6fca6a61 CH |
587 | } |
588 | EXPORT_SYMBOL(blk_mq_add_to_requeue_list); | |
589 | ||
590 | void blk_mq_kick_requeue_list(struct request_queue *q) | |
591 | { | |
2849450a | 592 | kblockd_schedule_delayed_work(&q->requeue_work, 0); |
6fca6a61 CH |
593 | } |
594 | EXPORT_SYMBOL(blk_mq_kick_requeue_list); | |
595 | ||
2849450a MS |
596 | void blk_mq_delay_kick_requeue_list(struct request_queue *q, |
597 | unsigned long msecs) | |
598 | { | |
599 | kblockd_schedule_delayed_work(&q->requeue_work, | |
600 | msecs_to_jiffies(msecs)); | |
601 | } | |
602 | EXPORT_SYMBOL(blk_mq_delay_kick_requeue_list); | |
603 | ||
1885b24d JA |
604 | void blk_mq_abort_requeue_list(struct request_queue *q) |
605 | { | |
606 | unsigned long flags; | |
607 | LIST_HEAD(rq_list); | |
608 | ||
609 | spin_lock_irqsave(&q->requeue_lock, flags); | |
610 | list_splice_init(&q->requeue_list, &rq_list); | |
611 | spin_unlock_irqrestore(&q->requeue_lock, flags); | |
612 | ||
613 | while (!list_empty(&rq_list)) { | |
614 | struct request *rq; | |
615 | ||
616 | rq = list_first_entry(&rq_list, struct request, queuelist); | |
617 | list_del_init(&rq->queuelist); | |
618 | rq->errors = -EIO; | |
619 | blk_mq_end_request(rq, rq->errors); | |
620 | } | |
621 | } | |
622 | EXPORT_SYMBOL(blk_mq_abort_requeue_list); | |
623 | ||
0e62f51f JA |
624 | struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag) |
625 | { | |
88c7b2b7 JA |
626 | if (tag < tags->nr_tags) { |
627 | prefetch(tags->rqs[tag]); | |
4ee86bab | 628 | return tags->rqs[tag]; |
88c7b2b7 | 629 | } |
4ee86bab HR |
630 | |
631 | return NULL; | |
24d2f903 CH |
632 | } |
633 | EXPORT_SYMBOL(blk_mq_tag_to_rq); | |
634 | ||
320ae51f | 635 | struct blk_mq_timeout_data { |
46f92d42 CH |
636 | unsigned long next; |
637 | unsigned int next_set; | |
320ae51f JA |
638 | }; |
639 | ||
90415837 | 640 | void blk_mq_rq_timed_out(struct request *req, bool reserved) |
320ae51f | 641 | { |
46f92d42 CH |
642 | struct blk_mq_ops *ops = req->q->mq_ops; |
643 | enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER; | |
87ee7b11 JA |
644 | |
645 | /* | |
646 | * We know that complete is set at this point. If STARTED isn't set | |
647 | * anymore, then the request isn't active and the "timeout" should | |
648 | * just be ignored. This can happen due to the bitflag ordering. | |
649 | * Timeout first checks if STARTED is set, and if it is, assumes | |
650 | * the request is active. But if we race with completion, then | |
651 | * we both flags will get cleared. So check here again, and ignore | |
652 | * a timeout event with a request that isn't active. | |
653 | */ | |
46f92d42 CH |
654 | if (!test_bit(REQ_ATOM_STARTED, &req->atomic_flags)) |
655 | return; | |
87ee7b11 | 656 | |
46f92d42 | 657 | if (ops->timeout) |
0152fb6b | 658 | ret = ops->timeout(req, reserved); |
46f92d42 CH |
659 | |
660 | switch (ret) { | |
661 | case BLK_EH_HANDLED: | |
662 | __blk_mq_complete_request(req); | |
663 | break; | |
664 | case BLK_EH_RESET_TIMER: | |
665 | blk_add_timer(req); | |
666 | blk_clear_rq_complete(req); | |
667 | break; | |
668 | case BLK_EH_NOT_HANDLED: | |
669 | break; | |
670 | default: | |
671 | printk(KERN_ERR "block: bad eh return: %d\n", ret); | |
672 | break; | |
673 | } | |
87ee7b11 | 674 | } |
5b3f25fc | 675 | |
81481eb4 CH |
676 | static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx, |
677 | struct request *rq, void *priv, bool reserved) | |
678 | { | |
679 | struct blk_mq_timeout_data *data = priv; | |
87ee7b11 | 680 | |
eb130dbf KB |
681 | if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) { |
682 | /* | |
683 | * If a request wasn't started before the queue was | |
684 | * marked dying, kill it here or it'll go unnoticed. | |
685 | */ | |
a59e0f57 KB |
686 | if (unlikely(blk_queue_dying(rq->q))) { |
687 | rq->errors = -EIO; | |
688 | blk_mq_end_request(rq, rq->errors); | |
689 | } | |
46f92d42 | 690 | return; |
eb130dbf | 691 | } |
87ee7b11 | 692 | |
46f92d42 CH |
693 | if (time_after_eq(jiffies, rq->deadline)) { |
694 | if (!blk_mark_rq_complete(rq)) | |
0152fb6b | 695 | blk_mq_rq_timed_out(rq, reserved); |
46f92d42 CH |
696 | } else if (!data->next_set || time_after(data->next, rq->deadline)) { |
697 | data->next = rq->deadline; | |
698 | data->next_set = 1; | |
699 | } | |
87ee7b11 JA |
700 | } |
701 | ||
287922eb | 702 | static void blk_mq_timeout_work(struct work_struct *work) |
320ae51f | 703 | { |
287922eb CH |
704 | struct request_queue *q = |
705 | container_of(work, struct request_queue, timeout_work); | |
81481eb4 CH |
706 | struct blk_mq_timeout_data data = { |
707 | .next = 0, | |
708 | .next_set = 0, | |
709 | }; | |
81481eb4 | 710 | int i; |
320ae51f | 711 | |
71f79fb3 GKB |
712 | /* A deadlock might occur if a request is stuck requiring a |
713 | * timeout at the same time a queue freeze is waiting | |
714 | * completion, since the timeout code would not be able to | |
715 | * acquire the queue reference here. | |
716 | * | |
717 | * That's why we don't use blk_queue_enter here; instead, we use | |
718 | * percpu_ref_tryget directly, because we need to be able to | |
719 | * obtain a reference even in the short window between the queue | |
720 | * starting to freeze, by dropping the first reference in | |
721 | * blk_mq_freeze_queue_start, and the moment the last request is | |
722 | * consumed, marked by the instant q_usage_counter reaches | |
723 | * zero. | |
724 | */ | |
725 | if (!percpu_ref_tryget(&q->q_usage_counter)) | |
287922eb CH |
726 | return; |
727 | ||
0bf6cd5b | 728 | blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &data); |
320ae51f | 729 | |
81481eb4 CH |
730 | if (data.next_set) { |
731 | data.next = blk_rq_timeout(round_jiffies_up(data.next)); | |
732 | mod_timer(&q->timeout, data.next); | |
0d2602ca | 733 | } else { |
0bf6cd5b CH |
734 | struct blk_mq_hw_ctx *hctx; |
735 | ||
f054b56c ML |
736 | queue_for_each_hw_ctx(q, hctx, i) { |
737 | /* the hctx may be unmapped, so check it here */ | |
738 | if (blk_mq_hw_queue_mapped(hctx)) | |
739 | blk_mq_tag_idle(hctx); | |
740 | } | |
0d2602ca | 741 | } |
287922eb | 742 | blk_queue_exit(q); |
320ae51f JA |
743 | } |
744 | ||
745 | /* | |
746 | * Reverse check our software queue for entries that we could potentially | |
747 | * merge with. Currently includes a hand-wavy stop count of 8, to not spend | |
748 | * too much time checking for merges. | |
749 | */ | |
750 | static bool blk_mq_attempt_merge(struct request_queue *q, | |
751 | struct blk_mq_ctx *ctx, struct bio *bio) | |
752 | { | |
753 | struct request *rq; | |
754 | int checked = 8; | |
755 | ||
756 | list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) { | |
757 | int el_ret; | |
758 | ||
759 | if (!checked--) | |
760 | break; | |
761 | ||
762 | if (!blk_rq_merge_ok(rq, bio)) | |
763 | continue; | |
764 | ||
765 | el_ret = blk_try_merge(rq, bio); | |
766 | if (el_ret == ELEVATOR_BACK_MERGE) { | |
767 | if (bio_attempt_back_merge(q, rq, bio)) { | |
768 | ctx->rq_merged++; | |
769 | return true; | |
770 | } | |
771 | break; | |
772 | } else if (el_ret == ELEVATOR_FRONT_MERGE) { | |
773 | if (bio_attempt_front_merge(q, rq, bio)) { | |
774 | ctx->rq_merged++; | |
775 | return true; | |
776 | } | |
777 | break; | |
778 | } | |
779 | } | |
780 | ||
781 | return false; | |
782 | } | |
783 | ||
88459642 OS |
784 | struct flush_busy_ctx_data { |
785 | struct blk_mq_hw_ctx *hctx; | |
786 | struct list_head *list; | |
787 | }; | |
788 | ||
789 | static bool flush_busy_ctx(struct sbitmap *sb, unsigned int bitnr, void *data) | |
790 | { | |
791 | struct flush_busy_ctx_data *flush_data = data; | |
792 | struct blk_mq_hw_ctx *hctx = flush_data->hctx; | |
793 | struct blk_mq_ctx *ctx = hctx->ctxs[bitnr]; | |
794 | ||
795 | sbitmap_clear_bit(sb, bitnr); | |
796 | spin_lock(&ctx->lock); | |
797 | list_splice_tail_init(&ctx->rq_list, flush_data->list); | |
798 | spin_unlock(&ctx->lock); | |
799 | return true; | |
800 | } | |
801 | ||
1429d7c9 JA |
802 | /* |
803 | * Process software queues that have been marked busy, splicing them | |
804 | * to the for-dispatch | |
805 | */ | |
806 | static void flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) | |
807 | { | |
88459642 OS |
808 | struct flush_busy_ctx_data data = { |
809 | .hctx = hctx, | |
810 | .list = list, | |
811 | }; | |
1429d7c9 | 812 | |
88459642 | 813 | sbitmap_for_each_set(&hctx->ctx_map, flush_busy_ctx, &data); |
1429d7c9 | 814 | } |
1429d7c9 | 815 | |
703fd1c0 JA |
816 | static inline unsigned int queued_to_index(unsigned int queued) |
817 | { | |
818 | if (!queued) | |
819 | return 0; | |
1429d7c9 | 820 | |
703fd1c0 | 821 | return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1); |
1429d7c9 JA |
822 | } |
823 | ||
f04c3df3 | 824 | bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list) |
320ae51f JA |
825 | { |
826 | struct request_queue *q = hctx->queue; | |
320ae51f | 827 | struct request *rq; |
74c45052 JA |
828 | LIST_HEAD(driver_list); |
829 | struct list_head *dptr; | |
f04c3df3 | 830 | int queued, ret = BLK_MQ_RQ_QUEUE_OK; |
320ae51f | 831 | |
74c45052 JA |
832 | /* |
833 | * Start off with dptr being NULL, so we start the first request | |
834 | * immediately, even if we have more pending. | |
835 | */ | |
836 | dptr = NULL; | |
837 | ||
320ae51f JA |
838 | /* |
839 | * Now process all the entries, sending them to the driver. | |
840 | */ | |
1429d7c9 | 841 | queued = 0; |
f04c3df3 | 842 | while (!list_empty(list)) { |
74c45052 | 843 | struct blk_mq_queue_data bd; |
320ae51f | 844 | |
f04c3df3 | 845 | rq = list_first_entry(list, struct request, queuelist); |
320ae51f | 846 | list_del_init(&rq->queuelist); |
320ae51f | 847 | |
74c45052 JA |
848 | bd.rq = rq; |
849 | bd.list = dptr; | |
f04c3df3 | 850 | bd.last = list_empty(list); |
74c45052 JA |
851 | |
852 | ret = q->mq_ops->queue_rq(hctx, &bd); | |
320ae51f JA |
853 | switch (ret) { |
854 | case BLK_MQ_RQ_QUEUE_OK: | |
855 | queued++; | |
52b9c330 | 856 | break; |
320ae51f | 857 | case BLK_MQ_RQ_QUEUE_BUSY: |
f04c3df3 | 858 | list_add(&rq->queuelist, list); |
ed0791b2 | 859 | __blk_mq_requeue_request(rq); |
320ae51f JA |
860 | break; |
861 | default: | |
862 | pr_err("blk-mq: bad return on queue: %d\n", ret); | |
320ae51f | 863 | case BLK_MQ_RQ_QUEUE_ERROR: |
1e93b8c2 | 864 | rq->errors = -EIO; |
c8a446ad | 865 | blk_mq_end_request(rq, rq->errors); |
320ae51f JA |
866 | break; |
867 | } | |
868 | ||
869 | if (ret == BLK_MQ_RQ_QUEUE_BUSY) | |
870 | break; | |
74c45052 JA |
871 | |
872 | /* | |
873 | * We've done the first request. If we have more than 1 | |
874 | * left in the list, set dptr to defer issue. | |
875 | */ | |
f04c3df3 | 876 | if (!dptr && list->next != list->prev) |
74c45052 | 877 | dptr = &driver_list; |
320ae51f JA |
878 | } |
879 | ||
703fd1c0 | 880 | hctx->dispatched[queued_to_index(queued)]++; |
320ae51f JA |
881 | |
882 | /* | |
883 | * Any items that need requeuing? Stuff them into hctx->dispatch, | |
884 | * that is where we will continue on next queue run. | |
885 | */ | |
f04c3df3 | 886 | if (!list_empty(list)) { |
320ae51f | 887 | spin_lock(&hctx->lock); |
f04c3df3 | 888 | list_splice(list, &hctx->dispatch); |
320ae51f | 889 | spin_unlock(&hctx->lock); |
f04c3df3 | 890 | |
9ba52e58 SL |
891 | /* |
892 | * the queue is expected stopped with BLK_MQ_RQ_QUEUE_BUSY, but | |
893 | * it's possible the queue is stopped and restarted again | |
894 | * before this. Queue restart will dispatch requests. And since | |
895 | * requests in rq_list aren't added into hctx->dispatch yet, | |
896 | * the requests in rq_list might get lost. | |
897 | * | |
898 | * blk_mq_run_hw_queue() already checks the STOPPED bit | |
899 | **/ | |
900 | blk_mq_run_hw_queue(hctx, true); | |
320ae51f | 901 | } |
f04c3df3 JA |
902 | |
903 | return ret != BLK_MQ_RQ_QUEUE_BUSY; | |
904 | } | |
905 | ||
906 | /* | |
907 | * Run this hardware queue, pulling any software queues mapped to it in. | |
908 | * Note that this function currently has various problems around ordering | |
909 | * of IO. In particular, we'd like FIFO behaviour on handling existing | |
910 | * items on the hctx->dispatch list. Ignore that for now. | |
911 | */ | |
912 | static void blk_mq_process_rq_list(struct blk_mq_hw_ctx *hctx) | |
913 | { | |
914 | LIST_HEAD(rq_list); | |
915 | LIST_HEAD(driver_list); | |
916 | ||
917 | if (unlikely(blk_mq_hctx_stopped(hctx))) | |
918 | return; | |
919 | ||
920 | hctx->run++; | |
921 | ||
922 | /* | |
923 | * Touch any software queue that has pending entries. | |
924 | */ | |
925 | flush_busy_ctxs(hctx, &rq_list); | |
926 | ||
927 | /* | |
928 | * If we have previous entries on our dispatch list, grab them | |
929 | * and stuff them at the front for more fair dispatch. | |
930 | */ | |
931 | if (!list_empty_careful(&hctx->dispatch)) { | |
932 | spin_lock(&hctx->lock); | |
933 | if (!list_empty(&hctx->dispatch)) | |
934 | list_splice_init(&hctx->dispatch, &rq_list); | |
935 | spin_unlock(&hctx->lock); | |
936 | } | |
937 | ||
938 | blk_mq_dispatch_rq_list(hctx, &rq_list); | |
320ae51f JA |
939 | } |
940 | ||
6a83e74d BVA |
941 | static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) |
942 | { | |
943 | int srcu_idx; | |
944 | ||
945 | WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) && | |
946 | cpu_online(hctx->next_cpu)); | |
947 | ||
948 | if (!(hctx->flags & BLK_MQ_F_BLOCKING)) { | |
949 | rcu_read_lock(); | |
950 | blk_mq_process_rq_list(hctx); | |
951 | rcu_read_unlock(); | |
952 | } else { | |
953 | srcu_idx = srcu_read_lock(&hctx->queue_rq_srcu); | |
954 | blk_mq_process_rq_list(hctx); | |
955 | srcu_read_unlock(&hctx->queue_rq_srcu, srcu_idx); | |
956 | } | |
957 | } | |
958 | ||
506e931f JA |
959 | /* |
960 | * It'd be great if the workqueue API had a way to pass | |
961 | * in a mask and had some smarts for more clever placement. | |
962 | * For now we just round-robin here, switching for every | |
963 | * BLK_MQ_CPU_WORK_BATCH queued items. | |
964 | */ | |
965 | static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx) | |
966 | { | |
b657d7e6 CH |
967 | if (hctx->queue->nr_hw_queues == 1) |
968 | return WORK_CPU_UNBOUND; | |
506e931f JA |
969 | |
970 | if (--hctx->next_cpu_batch <= 0) { | |
c02ebfdd | 971 | int next_cpu; |
506e931f JA |
972 | |
973 | next_cpu = cpumask_next(hctx->next_cpu, hctx->cpumask); | |
974 | if (next_cpu >= nr_cpu_ids) | |
975 | next_cpu = cpumask_first(hctx->cpumask); | |
976 | ||
977 | hctx->next_cpu = next_cpu; | |
978 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
979 | } | |
980 | ||
b657d7e6 | 981 | return hctx->next_cpu; |
506e931f JA |
982 | } |
983 | ||
320ae51f JA |
984 | void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
985 | { | |
5d1b25c1 BVA |
986 | if (unlikely(blk_mq_hctx_stopped(hctx) || |
987 | !blk_mq_hw_queue_mapped(hctx))) | |
320ae51f JA |
988 | return; |
989 | ||
1b792f2f | 990 | if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) { |
2a90d4aa PB |
991 | int cpu = get_cpu(); |
992 | if (cpumask_test_cpu(cpu, hctx->cpumask)) { | |
398205b8 | 993 | __blk_mq_run_hw_queue(hctx); |
2a90d4aa | 994 | put_cpu(); |
398205b8 PB |
995 | return; |
996 | } | |
e4043dcf | 997 | |
2a90d4aa | 998 | put_cpu(); |
e4043dcf | 999 | } |
398205b8 | 1000 | |
27489a3c | 1001 | kblockd_schedule_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work); |
320ae51f JA |
1002 | } |
1003 | ||
b94ec296 | 1004 | void blk_mq_run_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
1005 | { |
1006 | struct blk_mq_hw_ctx *hctx; | |
1007 | int i; | |
1008 | ||
1009 | queue_for_each_hw_ctx(q, hctx, i) { | |
1010 | if ((!blk_mq_hctx_has_pending(hctx) && | |
1011 | list_empty_careful(&hctx->dispatch)) || | |
5d1b25c1 | 1012 | blk_mq_hctx_stopped(hctx)) |
320ae51f JA |
1013 | continue; |
1014 | ||
b94ec296 | 1015 | blk_mq_run_hw_queue(hctx, async); |
320ae51f JA |
1016 | } |
1017 | } | |
b94ec296 | 1018 | EXPORT_SYMBOL(blk_mq_run_hw_queues); |
320ae51f | 1019 | |
fd001443 BVA |
1020 | /** |
1021 | * blk_mq_queue_stopped() - check whether one or more hctxs have been stopped | |
1022 | * @q: request queue. | |
1023 | * | |
1024 | * The caller is responsible for serializing this function against | |
1025 | * blk_mq_{start,stop}_hw_queue(). | |
1026 | */ | |
1027 | bool blk_mq_queue_stopped(struct request_queue *q) | |
1028 | { | |
1029 | struct blk_mq_hw_ctx *hctx; | |
1030 | int i; | |
1031 | ||
1032 | queue_for_each_hw_ctx(q, hctx, i) | |
1033 | if (blk_mq_hctx_stopped(hctx)) | |
1034 | return true; | |
1035 | ||
1036 | return false; | |
1037 | } | |
1038 | EXPORT_SYMBOL(blk_mq_queue_stopped); | |
1039 | ||
320ae51f JA |
1040 | void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx) |
1041 | { | |
27489a3c | 1042 | cancel_work(&hctx->run_work); |
70f4db63 | 1043 | cancel_delayed_work(&hctx->delay_work); |
320ae51f JA |
1044 | set_bit(BLK_MQ_S_STOPPED, &hctx->state); |
1045 | } | |
1046 | EXPORT_SYMBOL(blk_mq_stop_hw_queue); | |
1047 | ||
280d45f6 CH |
1048 | void blk_mq_stop_hw_queues(struct request_queue *q) |
1049 | { | |
1050 | struct blk_mq_hw_ctx *hctx; | |
1051 | int i; | |
1052 | ||
1053 | queue_for_each_hw_ctx(q, hctx, i) | |
1054 | blk_mq_stop_hw_queue(hctx); | |
1055 | } | |
1056 | EXPORT_SYMBOL(blk_mq_stop_hw_queues); | |
1057 | ||
320ae51f JA |
1058 | void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx) |
1059 | { | |
1060 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
e4043dcf | 1061 | |
0ffbce80 | 1062 | blk_mq_run_hw_queue(hctx, false); |
320ae51f JA |
1063 | } |
1064 | EXPORT_SYMBOL(blk_mq_start_hw_queue); | |
1065 | ||
2f268556 CH |
1066 | void blk_mq_start_hw_queues(struct request_queue *q) |
1067 | { | |
1068 | struct blk_mq_hw_ctx *hctx; | |
1069 | int i; | |
1070 | ||
1071 | queue_for_each_hw_ctx(q, hctx, i) | |
1072 | blk_mq_start_hw_queue(hctx); | |
1073 | } | |
1074 | EXPORT_SYMBOL(blk_mq_start_hw_queues); | |
1075 | ||
ae911c5e JA |
1076 | void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async) |
1077 | { | |
1078 | if (!blk_mq_hctx_stopped(hctx)) | |
1079 | return; | |
1080 | ||
1081 | clear_bit(BLK_MQ_S_STOPPED, &hctx->state); | |
1082 | blk_mq_run_hw_queue(hctx, async); | |
1083 | } | |
1084 | EXPORT_SYMBOL_GPL(blk_mq_start_stopped_hw_queue); | |
1085 | ||
1b4a3258 | 1086 | void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async) |
320ae51f JA |
1087 | { |
1088 | struct blk_mq_hw_ctx *hctx; | |
1089 | int i; | |
1090 | ||
ae911c5e JA |
1091 | queue_for_each_hw_ctx(q, hctx, i) |
1092 | blk_mq_start_stopped_hw_queue(hctx, async); | |
320ae51f JA |
1093 | } |
1094 | EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues); | |
1095 | ||
70f4db63 | 1096 | static void blk_mq_run_work_fn(struct work_struct *work) |
320ae51f JA |
1097 | { |
1098 | struct blk_mq_hw_ctx *hctx; | |
1099 | ||
27489a3c | 1100 | hctx = container_of(work, struct blk_mq_hw_ctx, run_work); |
e4043dcf | 1101 | |
320ae51f JA |
1102 | __blk_mq_run_hw_queue(hctx); |
1103 | } | |
1104 | ||
70f4db63 CH |
1105 | static void blk_mq_delay_work_fn(struct work_struct *work) |
1106 | { | |
1107 | struct blk_mq_hw_ctx *hctx; | |
1108 | ||
1109 | hctx = container_of(work, struct blk_mq_hw_ctx, delay_work.work); | |
1110 | ||
1111 | if (test_and_clear_bit(BLK_MQ_S_STOPPED, &hctx->state)) | |
1112 | __blk_mq_run_hw_queue(hctx); | |
1113 | } | |
1114 | ||
1115 | void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs) | |
1116 | { | |
19c66e59 ML |
1117 | if (unlikely(!blk_mq_hw_queue_mapped(hctx))) |
1118 | return; | |
70f4db63 | 1119 | |
b657d7e6 CH |
1120 | kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx), |
1121 | &hctx->delay_work, msecs_to_jiffies(msecs)); | |
70f4db63 CH |
1122 | } |
1123 | EXPORT_SYMBOL(blk_mq_delay_queue); | |
1124 | ||
cfd0c552 | 1125 | static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx, |
cfd0c552 ML |
1126 | struct request *rq, |
1127 | bool at_head) | |
320ae51f | 1128 | { |
e57690fe JA |
1129 | struct blk_mq_ctx *ctx = rq->mq_ctx; |
1130 | ||
01b983c9 JA |
1131 | trace_block_rq_insert(hctx->queue, rq); |
1132 | ||
72a0a36e CH |
1133 | if (at_head) |
1134 | list_add(&rq->queuelist, &ctx->rq_list); | |
1135 | else | |
1136 | list_add_tail(&rq->queuelist, &ctx->rq_list); | |
cfd0c552 | 1137 | } |
4bb659b1 | 1138 | |
cfd0c552 ML |
1139 | static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, |
1140 | struct request *rq, bool at_head) | |
1141 | { | |
1142 | struct blk_mq_ctx *ctx = rq->mq_ctx; | |
1143 | ||
e57690fe | 1144 | __blk_mq_insert_req_list(hctx, rq, at_head); |
320ae51f | 1145 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f JA |
1146 | } |
1147 | ||
eeabc850 | 1148 | void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue, |
e57690fe | 1149 | bool async) |
320ae51f | 1150 | { |
e57690fe | 1151 | struct blk_mq_ctx *ctx = rq->mq_ctx; |
eeabc850 | 1152 | struct request_queue *q = rq->q; |
7d7e0f90 | 1153 | struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); |
320ae51f | 1154 | |
a57a178a CH |
1155 | spin_lock(&ctx->lock); |
1156 | __blk_mq_insert_request(hctx, rq, at_head); | |
1157 | spin_unlock(&ctx->lock); | |
320ae51f | 1158 | |
320ae51f JA |
1159 | if (run_queue) |
1160 | blk_mq_run_hw_queue(hctx, async); | |
1161 | } | |
1162 | ||
1163 | static void blk_mq_insert_requests(struct request_queue *q, | |
1164 | struct blk_mq_ctx *ctx, | |
1165 | struct list_head *list, | |
1166 | int depth, | |
1167 | bool from_schedule) | |
1168 | ||
1169 | { | |
7d7e0f90 | 1170 | struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu); |
320ae51f JA |
1171 | |
1172 | trace_block_unplug(q, depth, !from_schedule); | |
1173 | ||
320ae51f JA |
1174 | /* |
1175 | * preemption doesn't flush plug list, so it's possible ctx->cpu is | |
1176 | * offline now | |
1177 | */ | |
1178 | spin_lock(&ctx->lock); | |
1179 | while (!list_empty(list)) { | |
1180 | struct request *rq; | |
1181 | ||
1182 | rq = list_first_entry(list, struct request, queuelist); | |
e57690fe | 1183 | BUG_ON(rq->mq_ctx != ctx); |
320ae51f | 1184 | list_del_init(&rq->queuelist); |
e57690fe | 1185 | __blk_mq_insert_req_list(hctx, rq, false); |
320ae51f | 1186 | } |
cfd0c552 | 1187 | blk_mq_hctx_mark_pending(hctx, ctx); |
320ae51f JA |
1188 | spin_unlock(&ctx->lock); |
1189 | ||
320ae51f JA |
1190 | blk_mq_run_hw_queue(hctx, from_schedule); |
1191 | } | |
1192 | ||
1193 | static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b) | |
1194 | { | |
1195 | struct request *rqa = container_of(a, struct request, queuelist); | |
1196 | struct request *rqb = container_of(b, struct request, queuelist); | |
1197 | ||
1198 | return !(rqa->mq_ctx < rqb->mq_ctx || | |
1199 | (rqa->mq_ctx == rqb->mq_ctx && | |
1200 | blk_rq_pos(rqa) < blk_rq_pos(rqb))); | |
1201 | } | |
1202 | ||
1203 | void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) | |
1204 | { | |
1205 | struct blk_mq_ctx *this_ctx; | |
1206 | struct request_queue *this_q; | |
1207 | struct request *rq; | |
1208 | LIST_HEAD(list); | |
1209 | LIST_HEAD(ctx_list); | |
1210 | unsigned int depth; | |
1211 | ||
1212 | list_splice_init(&plug->mq_list, &list); | |
1213 | ||
1214 | list_sort(NULL, &list, plug_ctx_cmp); | |
1215 | ||
1216 | this_q = NULL; | |
1217 | this_ctx = NULL; | |
1218 | depth = 0; | |
1219 | ||
1220 | while (!list_empty(&list)) { | |
1221 | rq = list_entry_rq(list.next); | |
1222 | list_del_init(&rq->queuelist); | |
1223 | BUG_ON(!rq->q); | |
1224 | if (rq->mq_ctx != this_ctx) { | |
1225 | if (this_ctx) { | |
1226 | blk_mq_insert_requests(this_q, this_ctx, | |
1227 | &ctx_list, depth, | |
1228 | from_schedule); | |
1229 | } | |
1230 | ||
1231 | this_ctx = rq->mq_ctx; | |
1232 | this_q = rq->q; | |
1233 | depth = 0; | |
1234 | } | |
1235 | ||
1236 | depth++; | |
1237 | list_add_tail(&rq->queuelist, &ctx_list); | |
1238 | } | |
1239 | ||
1240 | /* | |
1241 | * If 'this_ctx' is set, we know we have entries to complete | |
1242 | * on 'ctx_list'. Do those. | |
1243 | */ | |
1244 | if (this_ctx) { | |
1245 | blk_mq_insert_requests(this_q, this_ctx, &ctx_list, depth, | |
1246 | from_schedule); | |
1247 | } | |
1248 | } | |
1249 | ||
1250 | static void blk_mq_bio_to_request(struct request *rq, struct bio *bio) | |
1251 | { | |
1252 | init_request_from_bio(rq, bio); | |
4b570521 | 1253 | |
6e85eaf3 | 1254 | blk_account_io_start(rq, true); |
320ae51f JA |
1255 | } |
1256 | ||
274a5843 JA |
1257 | static inline bool hctx_allow_merges(struct blk_mq_hw_ctx *hctx) |
1258 | { | |
1259 | return (hctx->flags & BLK_MQ_F_SHOULD_MERGE) && | |
1260 | !blk_queue_nomerges(hctx->queue); | |
1261 | } | |
1262 | ||
07068d5b JA |
1263 | static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx, |
1264 | struct blk_mq_ctx *ctx, | |
1265 | struct request *rq, struct bio *bio) | |
320ae51f | 1266 | { |
e18378a6 | 1267 | if (!hctx_allow_merges(hctx) || !bio_mergeable(bio)) { |
07068d5b JA |
1268 | blk_mq_bio_to_request(rq, bio); |
1269 | spin_lock(&ctx->lock); | |
1270 | insert_rq: | |
1271 | __blk_mq_insert_request(hctx, rq, false); | |
1272 | spin_unlock(&ctx->lock); | |
1273 | return false; | |
1274 | } else { | |
274a5843 JA |
1275 | struct request_queue *q = hctx->queue; |
1276 | ||
07068d5b JA |
1277 | spin_lock(&ctx->lock); |
1278 | if (!blk_mq_attempt_merge(q, ctx, bio)) { | |
1279 | blk_mq_bio_to_request(rq, bio); | |
1280 | goto insert_rq; | |
1281 | } | |
320ae51f | 1282 | |
07068d5b JA |
1283 | spin_unlock(&ctx->lock); |
1284 | __blk_mq_free_request(hctx, ctx, rq); | |
1285 | return true; | |
14ec77f3 | 1286 | } |
07068d5b | 1287 | } |
14ec77f3 | 1288 | |
07068d5b JA |
1289 | static struct request *blk_mq_map_request(struct request_queue *q, |
1290 | struct bio *bio, | |
2552e3f8 | 1291 | struct blk_mq_alloc_data *data) |
07068d5b JA |
1292 | { |
1293 | struct blk_mq_hw_ctx *hctx; | |
1294 | struct blk_mq_ctx *ctx; | |
1295 | struct request *rq; | |
320ae51f | 1296 | |
3ef28e83 | 1297 | blk_queue_enter_live(q); |
320ae51f | 1298 | ctx = blk_mq_get_ctx(q); |
7d7e0f90 | 1299 | hctx = blk_mq_map_queue(q, ctx->cpu); |
320ae51f | 1300 | |
ef295ecf | 1301 | trace_block_getrq(q, bio, bio->bi_opf); |
2552e3f8 | 1302 | blk_mq_set_alloc_data(data, q, 0, ctx, hctx); |
ef295ecf | 1303 | rq = __blk_mq_alloc_request(data, bio->bi_opf); |
320ae51f | 1304 | |
7dd2fb68 | 1305 | data->hctx->queued++; |
07068d5b JA |
1306 | return rq; |
1307 | } | |
1308 | ||
066a4a73 | 1309 | static void blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie) |
f984df1f SL |
1310 | { |
1311 | int ret; | |
1312 | struct request_queue *q = rq->q; | |
066a4a73 | 1313 | struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, rq->mq_ctx->cpu); |
f984df1f SL |
1314 | struct blk_mq_queue_data bd = { |
1315 | .rq = rq, | |
1316 | .list = NULL, | |
1317 | .last = 1 | |
1318 | }; | |
7b371636 | 1319 | blk_qc_t new_cookie = blk_tag_to_qc_t(rq->tag, hctx->queue_num); |
f984df1f | 1320 | |
2253efc8 BVA |
1321 | if (blk_mq_hctx_stopped(hctx)) |
1322 | goto insert; | |
1323 | ||
f984df1f SL |
1324 | /* |
1325 | * For OK queue, we are done. For error, kill it. Any other | |
1326 | * error (busy), just add it to our list as we previously | |
1327 | * would have done | |
1328 | */ | |
1329 | ret = q->mq_ops->queue_rq(hctx, &bd); | |
7b371636 JA |
1330 | if (ret == BLK_MQ_RQ_QUEUE_OK) { |
1331 | *cookie = new_cookie; | |
2253efc8 | 1332 | return; |
7b371636 | 1333 | } |
f984df1f | 1334 | |
7b371636 JA |
1335 | __blk_mq_requeue_request(rq); |
1336 | ||
1337 | if (ret == BLK_MQ_RQ_QUEUE_ERROR) { | |
1338 | *cookie = BLK_QC_T_NONE; | |
1339 | rq->errors = -EIO; | |
1340 | blk_mq_end_request(rq, rq->errors); | |
2253efc8 | 1341 | return; |
f984df1f | 1342 | } |
7b371636 | 1343 | |
2253efc8 BVA |
1344 | insert: |
1345 | blk_mq_insert_request(rq, false, true, true); | |
f984df1f SL |
1346 | } |
1347 | ||
07068d5b JA |
1348 | /* |
1349 | * Multiple hardware queue variant. This will not use per-process plugs, | |
1350 | * but will attempt to bypass the hctx queueing if we can go straight to | |
1351 | * hardware for SYNC IO. | |
1352 | */ | |
dece1635 | 1353 | static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) |
07068d5b | 1354 | { |
ef295ecf | 1355 | const int is_sync = op_is_sync(bio->bi_opf); |
1eff9d32 | 1356 | const int is_flush_fua = bio->bi_opf & (REQ_PREFLUSH | REQ_FUA); |
2552e3f8 | 1357 | struct blk_mq_alloc_data data; |
07068d5b | 1358 | struct request *rq; |
6a83e74d | 1359 | unsigned int request_count = 0, srcu_idx; |
f984df1f | 1360 | struct blk_plug *plug; |
5b3f341f | 1361 | struct request *same_queue_rq = NULL; |
7b371636 | 1362 | blk_qc_t cookie; |
87760e5e | 1363 | unsigned int wb_acct; |
07068d5b JA |
1364 | |
1365 | blk_queue_bounce(q, &bio); | |
1366 | ||
1367 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
4246a0b6 | 1368 | bio_io_error(bio); |
dece1635 | 1369 | return BLK_QC_T_NONE; |
07068d5b JA |
1370 | } |
1371 | ||
54efd50b KO |
1372 | blk_queue_split(q, &bio, q->bio_split); |
1373 | ||
87c279e6 OS |
1374 | if (!is_flush_fua && !blk_queue_nomerges(q) && |
1375 | blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq)) | |
1376 | return BLK_QC_T_NONE; | |
f984df1f | 1377 | |
87760e5e JA |
1378 | wb_acct = wbt_wait(q->rq_wb, bio, NULL); |
1379 | ||
07068d5b | 1380 | rq = blk_mq_map_request(q, bio, &data); |
87760e5e JA |
1381 | if (unlikely(!rq)) { |
1382 | __wbt_done(q->rq_wb, wb_acct); | |
dece1635 | 1383 | return BLK_QC_T_NONE; |
87760e5e JA |
1384 | } |
1385 | ||
1386 | wbt_track(&rq->issue_stat, wb_acct); | |
07068d5b | 1387 | |
7b371636 | 1388 | cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num); |
07068d5b JA |
1389 | |
1390 | if (unlikely(is_flush_fua)) { | |
1391 | blk_mq_bio_to_request(rq, bio); | |
1392 | blk_insert_flush(rq); | |
1393 | goto run_queue; | |
1394 | } | |
1395 | ||
f984df1f | 1396 | plug = current->plug; |
e167dfb5 JA |
1397 | /* |
1398 | * If the driver supports defer issued based on 'last', then | |
1399 | * queue it up like normal since we can potentially save some | |
1400 | * CPU this way. | |
1401 | */ | |
f984df1f SL |
1402 | if (((plug && !blk_queue_nomerges(q)) || is_sync) && |
1403 | !(data.hctx->flags & BLK_MQ_F_DEFER_ISSUE)) { | |
1404 | struct request *old_rq = NULL; | |
07068d5b JA |
1405 | |
1406 | blk_mq_bio_to_request(rq, bio); | |
07068d5b JA |
1407 | |
1408 | /* | |
6a83e74d | 1409 | * We do limited plugging. If the bio can be merged, do that. |
f984df1f SL |
1410 | * Otherwise the existing request in the plug list will be |
1411 | * issued. So the plug list will have one request at most | |
07068d5b | 1412 | */ |
f984df1f | 1413 | if (plug) { |
5b3f341f SL |
1414 | /* |
1415 | * The plug list might get flushed before this. If that | |
b094f89c JA |
1416 | * happens, same_queue_rq is invalid and plug list is |
1417 | * empty | |
1418 | */ | |
5b3f341f SL |
1419 | if (same_queue_rq && !list_empty(&plug->mq_list)) { |
1420 | old_rq = same_queue_rq; | |
f984df1f | 1421 | list_del_init(&old_rq->queuelist); |
07068d5b | 1422 | } |
f984df1f SL |
1423 | list_add_tail(&rq->queuelist, &plug->mq_list); |
1424 | } else /* is_sync */ | |
1425 | old_rq = rq; | |
1426 | blk_mq_put_ctx(data.ctx); | |
1427 | if (!old_rq) | |
7b371636 | 1428 | goto done; |
6a83e74d BVA |
1429 | |
1430 | if (!(data.hctx->flags & BLK_MQ_F_BLOCKING)) { | |
1431 | rcu_read_lock(); | |
066a4a73 | 1432 | blk_mq_try_issue_directly(old_rq, &cookie); |
6a83e74d BVA |
1433 | rcu_read_unlock(); |
1434 | } else { | |
1435 | srcu_idx = srcu_read_lock(&data.hctx->queue_rq_srcu); | |
066a4a73 | 1436 | blk_mq_try_issue_directly(old_rq, &cookie); |
6a83e74d BVA |
1437 | srcu_read_unlock(&data.hctx->queue_rq_srcu, srcu_idx); |
1438 | } | |
7b371636 | 1439 | goto done; |
07068d5b JA |
1440 | } |
1441 | ||
1442 | if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { | |
1443 | /* | |
1444 | * For a SYNC request, send it to the hardware immediately. For | |
1445 | * an ASYNC request, just ensure that we run it later on. The | |
1446 | * latter allows for merging opportunities and more efficient | |
1447 | * dispatching. | |
1448 | */ | |
1449 | run_queue: | |
1450 | blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); | |
1451 | } | |
07068d5b | 1452 | blk_mq_put_ctx(data.ctx); |
7b371636 JA |
1453 | done: |
1454 | return cookie; | |
07068d5b JA |
1455 | } |
1456 | ||
1457 | /* | |
1458 | * Single hardware queue variant. This will attempt to use any per-process | |
1459 | * plug for merging and IO deferral. | |
1460 | */ | |
dece1635 | 1461 | static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio) |
07068d5b | 1462 | { |
ef295ecf | 1463 | const int is_sync = op_is_sync(bio->bi_opf); |
1eff9d32 | 1464 | const int is_flush_fua = bio->bi_opf & (REQ_PREFLUSH | REQ_FUA); |
e6c4438b JM |
1465 | struct blk_plug *plug; |
1466 | unsigned int request_count = 0; | |
2552e3f8 | 1467 | struct blk_mq_alloc_data data; |
07068d5b | 1468 | struct request *rq; |
7b371636 | 1469 | blk_qc_t cookie; |
87760e5e | 1470 | unsigned int wb_acct; |
07068d5b | 1471 | |
07068d5b JA |
1472 | blk_queue_bounce(q, &bio); |
1473 | ||
1474 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { | |
4246a0b6 | 1475 | bio_io_error(bio); |
dece1635 | 1476 | return BLK_QC_T_NONE; |
07068d5b JA |
1477 | } |
1478 | ||
54efd50b KO |
1479 | blk_queue_split(q, &bio, q->bio_split); |
1480 | ||
87c279e6 OS |
1481 | if (!is_flush_fua && !blk_queue_nomerges(q)) { |
1482 | if (blk_attempt_plug_merge(q, bio, &request_count, NULL)) | |
1483 | return BLK_QC_T_NONE; | |
1484 | } else | |
1485 | request_count = blk_plug_queued_count(q); | |
07068d5b | 1486 | |
87760e5e JA |
1487 | wb_acct = wbt_wait(q->rq_wb, bio, NULL); |
1488 | ||
07068d5b | 1489 | rq = blk_mq_map_request(q, bio, &data); |
87760e5e JA |
1490 | if (unlikely(!rq)) { |
1491 | __wbt_done(q->rq_wb, wb_acct); | |
dece1635 | 1492 | return BLK_QC_T_NONE; |
87760e5e JA |
1493 | } |
1494 | ||
1495 | wbt_track(&rq->issue_stat, wb_acct); | |
320ae51f | 1496 | |
7b371636 | 1497 | cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num); |
320ae51f JA |
1498 | |
1499 | if (unlikely(is_flush_fua)) { | |
1500 | blk_mq_bio_to_request(rq, bio); | |
320ae51f JA |
1501 | blk_insert_flush(rq); |
1502 | goto run_queue; | |
1503 | } | |
1504 | ||
1505 | /* | |
1506 | * A task plug currently exists. Since this is completely lockless, | |
1507 | * utilize that to temporarily store requests until the task is | |
1508 | * either done or scheduled away. | |
1509 | */ | |
e6c4438b JM |
1510 | plug = current->plug; |
1511 | if (plug) { | |
600271d9 SL |
1512 | struct request *last = NULL; |
1513 | ||
e6c4438b | 1514 | blk_mq_bio_to_request(rq, bio); |
0a6219a9 ML |
1515 | |
1516 | /* | |
1517 | * @request_count may become stale because of schedule | |
1518 | * out, so check the list again. | |
1519 | */ | |
1520 | if (list_empty(&plug->mq_list)) | |
1521 | request_count = 0; | |
676d0607 | 1522 | if (!request_count) |
e6c4438b | 1523 | trace_block_plug(q); |
600271d9 SL |
1524 | else |
1525 | last = list_entry_rq(plug->mq_list.prev); | |
b094f89c JA |
1526 | |
1527 | blk_mq_put_ctx(data.ctx); | |
1528 | ||
600271d9 SL |
1529 | if (request_count >= BLK_MAX_REQUEST_COUNT || (last && |
1530 | blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE)) { | |
e6c4438b JM |
1531 | blk_flush_plug_list(plug, false); |
1532 | trace_block_plug(q); | |
320ae51f | 1533 | } |
b094f89c | 1534 | |
e6c4438b | 1535 | list_add_tail(&rq->queuelist, &plug->mq_list); |
7b371636 | 1536 | return cookie; |
320ae51f JA |
1537 | } |
1538 | ||
07068d5b JA |
1539 | if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) { |
1540 | /* | |
1541 | * For a SYNC request, send it to the hardware immediately. For | |
1542 | * an ASYNC request, just ensure that we run it later on. The | |
1543 | * latter allows for merging opportunities and more efficient | |
1544 | * dispatching. | |
1545 | */ | |
1546 | run_queue: | |
1547 | blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua); | |
320ae51f JA |
1548 | } |
1549 | ||
07068d5b | 1550 | blk_mq_put_ctx(data.ctx); |
7b371636 | 1551 | return cookie; |
320ae51f JA |
1552 | } |
1553 | ||
24d2f903 CH |
1554 | static void blk_mq_free_rq_map(struct blk_mq_tag_set *set, |
1555 | struct blk_mq_tags *tags, unsigned int hctx_idx) | |
95363efd | 1556 | { |
e9b267d9 | 1557 | struct page *page; |
320ae51f | 1558 | |
24d2f903 | 1559 | if (tags->rqs && set->ops->exit_request) { |
e9b267d9 | 1560 | int i; |
320ae51f | 1561 | |
24d2f903 CH |
1562 | for (i = 0; i < tags->nr_tags; i++) { |
1563 | if (!tags->rqs[i]) | |
e9b267d9 | 1564 | continue; |
24d2f903 CH |
1565 | set->ops->exit_request(set->driver_data, tags->rqs[i], |
1566 | hctx_idx, i); | |
a5164405 | 1567 | tags->rqs[i] = NULL; |
e9b267d9 | 1568 | } |
320ae51f | 1569 | } |
320ae51f | 1570 | |
24d2f903 CH |
1571 | while (!list_empty(&tags->page_list)) { |
1572 | page = list_first_entry(&tags->page_list, struct page, lru); | |
6753471c | 1573 | list_del_init(&page->lru); |
f75782e4 CM |
1574 | /* |
1575 | * Remove kmemleak object previously allocated in | |
1576 | * blk_mq_init_rq_map(). | |
1577 | */ | |
1578 | kmemleak_free(page_address(page)); | |
320ae51f JA |
1579 | __free_pages(page, page->private); |
1580 | } | |
1581 | ||
24d2f903 | 1582 | kfree(tags->rqs); |
320ae51f | 1583 | |
24d2f903 | 1584 | blk_mq_free_tags(tags); |
320ae51f JA |
1585 | } |
1586 | ||
1587 | static size_t order_to_size(unsigned int order) | |
1588 | { | |
4ca08500 | 1589 | return (size_t)PAGE_SIZE << order; |
320ae51f JA |
1590 | } |
1591 | ||
24d2f903 CH |
1592 | static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set, |
1593 | unsigned int hctx_idx) | |
320ae51f | 1594 | { |
24d2f903 | 1595 | struct blk_mq_tags *tags; |
320ae51f JA |
1596 | unsigned int i, j, entries_per_page, max_order = 4; |
1597 | size_t rq_size, left; | |
1598 | ||
24d2f903 | 1599 | tags = blk_mq_init_tags(set->queue_depth, set->reserved_tags, |
24391c0d SL |
1600 | set->numa_node, |
1601 | BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags)); | |
24d2f903 CH |
1602 | if (!tags) |
1603 | return NULL; | |
320ae51f | 1604 | |
24d2f903 CH |
1605 | INIT_LIST_HEAD(&tags->page_list); |
1606 | ||
a5164405 JA |
1607 | tags->rqs = kzalloc_node(set->queue_depth * sizeof(struct request *), |
1608 | GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY, | |
1609 | set->numa_node); | |
24d2f903 CH |
1610 | if (!tags->rqs) { |
1611 | blk_mq_free_tags(tags); | |
1612 | return NULL; | |
1613 | } | |
320ae51f JA |
1614 | |
1615 | /* | |
1616 | * rq_size is the size of the request plus driver payload, rounded | |
1617 | * to the cacheline size | |
1618 | */ | |
24d2f903 | 1619 | rq_size = round_up(sizeof(struct request) + set->cmd_size, |
320ae51f | 1620 | cache_line_size()); |
24d2f903 | 1621 | left = rq_size * set->queue_depth; |
320ae51f | 1622 | |
24d2f903 | 1623 | for (i = 0; i < set->queue_depth; ) { |
320ae51f JA |
1624 | int this_order = max_order; |
1625 | struct page *page; | |
1626 | int to_do; | |
1627 | void *p; | |
1628 | ||
b3a834b1 | 1629 | while (this_order && left < order_to_size(this_order - 1)) |
320ae51f JA |
1630 | this_order--; |
1631 | ||
1632 | do { | |
a5164405 | 1633 | page = alloc_pages_node(set->numa_node, |
ac211175 | 1634 | GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO, |
a5164405 | 1635 | this_order); |
320ae51f JA |
1636 | if (page) |
1637 | break; | |
1638 | if (!this_order--) | |
1639 | break; | |
1640 | if (order_to_size(this_order) < rq_size) | |
1641 | break; | |
1642 | } while (1); | |
1643 | ||
1644 | if (!page) | |
24d2f903 | 1645 | goto fail; |
320ae51f JA |
1646 | |
1647 | page->private = this_order; | |
24d2f903 | 1648 | list_add_tail(&page->lru, &tags->page_list); |
320ae51f JA |
1649 | |
1650 | p = page_address(page); | |
f75782e4 CM |
1651 | /* |
1652 | * Allow kmemleak to scan these pages as they contain pointers | |
1653 | * to additional allocations like via ops->init_request(). | |
1654 | */ | |
1655 | kmemleak_alloc(p, order_to_size(this_order), 1, GFP_KERNEL); | |
320ae51f | 1656 | entries_per_page = order_to_size(this_order) / rq_size; |
24d2f903 | 1657 | to_do = min(entries_per_page, set->queue_depth - i); |
320ae51f JA |
1658 | left -= to_do * rq_size; |
1659 | for (j = 0; j < to_do; j++) { | |
24d2f903 CH |
1660 | tags->rqs[i] = p; |
1661 | if (set->ops->init_request) { | |
1662 | if (set->ops->init_request(set->driver_data, | |
1663 | tags->rqs[i], hctx_idx, i, | |
a5164405 JA |
1664 | set->numa_node)) { |
1665 | tags->rqs[i] = NULL; | |
24d2f903 | 1666 | goto fail; |
a5164405 | 1667 | } |
e9b267d9 CH |
1668 | } |
1669 | ||
320ae51f JA |
1670 | p += rq_size; |
1671 | i++; | |
1672 | } | |
1673 | } | |
24d2f903 | 1674 | return tags; |
320ae51f | 1675 | |
24d2f903 | 1676 | fail: |
24d2f903 CH |
1677 | blk_mq_free_rq_map(set, tags, hctx_idx); |
1678 | return NULL; | |
320ae51f JA |
1679 | } |
1680 | ||
e57690fe JA |
1681 | /* |
1682 | * 'cpu' is going away. splice any existing rq_list entries from this | |
1683 | * software queue to the hw queue dispatch list, and ensure that it | |
1684 | * gets run. | |
1685 | */ | |
9467f859 | 1686 | static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node) |
484b4061 | 1687 | { |
9467f859 | 1688 | struct blk_mq_hw_ctx *hctx; |
484b4061 JA |
1689 | struct blk_mq_ctx *ctx; |
1690 | LIST_HEAD(tmp); | |
1691 | ||
9467f859 | 1692 | hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_dead); |
e57690fe | 1693 | ctx = __blk_mq_get_ctx(hctx->queue, cpu); |
484b4061 JA |
1694 | |
1695 | spin_lock(&ctx->lock); | |
1696 | if (!list_empty(&ctx->rq_list)) { | |
1697 | list_splice_init(&ctx->rq_list, &tmp); | |
1698 | blk_mq_hctx_clear_pending(hctx, ctx); | |
1699 | } | |
1700 | spin_unlock(&ctx->lock); | |
1701 | ||
1702 | if (list_empty(&tmp)) | |
9467f859 | 1703 | return 0; |
484b4061 | 1704 | |
e57690fe JA |
1705 | spin_lock(&hctx->lock); |
1706 | list_splice_tail_init(&tmp, &hctx->dispatch); | |
1707 | spin_unlock(&hctx->lock); | |
484b4061 JA |
1708 | |
1709 | blk_mq_run_hw_queue(hctx, true); | |
9467f859 | 1710 | return 0; |
484b4061 JA |
1711 | } |
1712 | ||
9467f859 | 1713 | static void blk_mq_remove_cpuhp(struct blk_mq_hw_ctx *hctx) |
484b4061 | 1714 | { |
9467f859 TG |
1715 | cpuhp_state_remove_instance_nocalls(CPUHP_BLK_MQ_DEAD, |
1716 | &hctx->cpuhp_dead); | |
484b4061 JA |
1717 | } |
1718 | ||
c3b4afca | 1719 | /* hctx->ctxs will be freed in queue's release handler */ |
08e98fc6 ML |
1720 | static void blk_mq_exit_hctx(struct request_queue *q, |
1721 | struct blk_mq_tag_set *set, | |
1722 | struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx) | |
1723 | { | |
f70ced09 ML |
1724 | unsigned flush_start_tag = set->queue_depth; |
1725 | ||
08e98fc6 ML |
1726 | blk_mq_tag_idle(hctx); |
1727 | ||
f70ced09 ML |
1728 | if (set->ops->exit_request) |
1729 | set->ops->exit_request(set->driver_data, | |
1730 | hctx->fq->flush_rq, hctx_idx, | |
1731 | flush_start_tag + hctx_idx); | |
1732 | ||
08e98fc6 ML |
1733 | if (set->ops->exit_hctx) |
1734 | set->ops->exit_hctx(hctx, hctx_idx); | |
1735 | ||
6a83e74d BVA |
1736 | if (hctx->flags & BLK_MQ_F_BLOCKING) |
1737 | cleanup_srcu_struct(&hctx->queue_rq_srcu); | |
1738 | ||
9467f859 | 1739 | blk_mq_remove_cpuhp(hctx); |
f70ced09 | 1740 | blk_free_flush_queue(hctx->fq); |
88459642 | 1741 | sbitmap_free(&hctx->ctx_map); |
08e98fc6 ML |
1742 | } |
1743 | ||
624dbe47 ML |
1744 | static void blk_mq_exit_hw_queues(struct request_queue *q, |
1745 | struct blk_mq_tag_set *set, int nr_queue) | |
1746 | { | |
1747 | struct blk_mq_hw_ctx *hctx; | |
1748 | unsigned int i; | |
1749 | ||
1750 | queue_for_each_hw_ctx(q, hctx, i) { | |
1751 | if (i == nr_queue) | |
1752 | break; | |
08e98fc6 | 1753 | blk_mq_exit_hctx(q, set, hctx, i); |
624dbe47 | 1754 | } |
624dbe47 ML |
1755 | } |
1756 | ||
1757 | static void blk_mq_free_hw_queues(struct request_queue *q, | |
1758 | struct blk_mq_tag_set *set) | |
1759 | { | |
1760 | struct blk_mq_hw_ctx *hctx; | |
1761 | unsigned int i; | |
1762 | ||
e09aae7e | 1763 | queue_for_each_hw_ctx(q, hctx, i) |
624dbe47 | 1764 | free_cpumask_var(hctx->cpumask); |
624dbe47 ML |
1765 | } |
1766 | ||
08e98fc6 ML |
1767 | static int blk_mq_init_hctx(struct request_queue *q, |
1768 | struct blk_mq_tag_set *set, | |
1769 | struct blk_mq_hw_ctx *hctx, unsigned hctx_idx) | |
320ae51f | 1770 | { |
08e98fc6 | 1771 | int node; |
f70ced09 | 1772 | unsigned flush_start_tag = set->queue_depth; |
08e98fc6 ML |
1773 | |
1774 | node = hctx->numa_node; | |
1775 | if (node == NUMA_NO_NODE) | |
1776 | node = hctx->numa_node = set->numa_node; | |
1777 | ||
27489a3c | 1778 | INIT_WORK(&hctx->run_work, blk_mq_run_work_fn); |
08e98fc6 ML |
1779 | INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn); |
1780 | spin_lock_init(&hctx->lock); | |
1781 | INIT_LIST_HEAD(&hctx->dispatch); | |
1782 | hctx->queue = q; | |
1783 | hctx->queue_num = hctx_idx; | |
2404e607 | 1784 | hctx->flags = set->flags & ~BLK_MQ_F_TAG_SHARED; |
08e98fc6 | 1785 | |
9467f859 | 1786 | cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, &hctx->cpuhp_dead); |
08e98fc6 ML |
1787 | |
1788 | hctx->tags = set->tags[hctx_idx]; | |
320ae51f JA |
1789 | |
1790 | /* | |
08e98fc6 ML |
1791 | * Allocate space for all possible cpus to avoid allocation at |
1792 | * runtime | |
320ae51f | 1793 | */ |
08e98fc6 ML |
1794 | hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *), |
1795 | GFP_KERNEL, node); | |
1796 | if (!hctx->ctxs) | |
1797 | goto unregister_cpu_notifier; | |
320ae51f | 1798 | |
88459642 OS |
1799 | if (sbitmap_init_node(&hctx->ctx_map, nr_cpu_ids, ilog2(8), GFP_KERNEL, |
1800 | node)) | |
08e98fc6 | 1801 | goto free_ctxs; |
320ae51f | 1802 | |
08e98fc6 | 1803 | hctx->nr_ctx = 0; |
320ae51f | 1804 | |
08e98fc6 ML |
1805 | if (set->ops->init_hctx && |
1806 | set->ops->init_hctx(hctx, set->driver_data, hctx_idx)) | |
1807 | goto free_bitmap; | |
320ae51f | 1808 | |
f70ced09 ML |
1809 | hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size); |
1810 | if (!hctx->fq) | |
1811 | goto exit_hctx; | |
320ae51f | 1812 | |
f70ced09 ML |
1813 | if (set->ops->init_request && |
1814 | set->ops->init_request(set->driver_data, | |
1815 | hctx->fq->flush_rq, hctx_idx, | |
1816 | flush_start_tag + hctx_idx, node)) | |
1817 | goto free_fq; | |
320ae51f | 1818 | |
6a83e74d BVA |
1819 | if (hctx->flags & BLK_MQ_F_BLOCKING) |
1820 | init_srcu_struct(&hctx->queue_rq_srcu); | |
1821 | ||
08e98fc6 | 1822 | return 0; |
320ae51f | 1823 | |
f70ced09 ML |
1824 | free_fq: |
1825 | kfree(hctx->fq); | |
1826 | exit_hctx: | |
1827 | if (set->ops->exit_hctx) | |
1828 | set->ops->exit_hctx(hctx, hctx_idx); | |
08e98fc6 | 1829 | free_bitmap: |
88459642 | 1830 | sbitmap_free(&hctx->ctx_map); |
08e98fc6 ML |
1831 | free_ctxs: |
1832 | kfree(hctx->ctxs); | |
1833 | unregister_cpu_notifier: | |
9467f859 | 1834 | blk_mq_remove_cpuhp(hctx); |
08e98fc6 ML |
1835 | return -1; |
1836 | } | |
320ae51f | 1837 | |
320ae51f JA |
1838 | static void blk_mq_init_cpu_queues(struct request_queue *q, |
1839 | unsigned int nr_hw_queues) | |
1840 | { | |
1841 | unsigned int i; | |
1842 | ||
1843 | for_each_possible_cpu(i) { | |
1844 | struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i); | |
1845 | struct blk_mq_hw_ctx *hctx; | |
1846 | ||
1847 | memset(__ctx, 0, sizeof(*__ctx)); | |
1848 | __ctx->cpu = i; | |
1849 | spin_lock_init(&__ctx->lock); | |
1850 | INIT_LIST_HEAD(&__ctx->rq_list); | |
1851 | __ctx->queue = q; | |
cf43e6be JA |
1852 | blk_stat_init(&__ctx->stat[BLK_STAT_READ]); |
1853 | blk_stat_init(&__ctx->stat[BLK_STAT_WRITE]); | |
320ae51f JA |
1854 | |
1855 | /* If the cpu isn't online, the cpu is mapped to first hctx */ | |
320ae51f JA |
1856 | if (!cpu_online(i)) |
1857 | continue; | |
1858 | ||
7d7e0f90 | 1859 | hctx = blk_mq_map_queue(q, i); |
e4043dcf | 1860 | |
320ae51f JA |
1861 | /* |
1862 | * Set local node, IFF we have more than one hw queue. If | |
1863 | * not, we remain on the home node of the device | |
1864 | */ | |
1865 | if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE) | |
bffed457 | 1866 | hctx->numa_node = local_memory_node(cpu_to_node(i)); |
320ae51f JA |
1867 | } |
1868 | } | |
1869 | ||
5778322e AM |
1870 | static void blk_mq_map_swqueue(struct request_queue *q, |
1871 | const struct cpumask *online_mask) | |
320ae51f JA |
1872 | { |
1873 | unsigned int i; | |
1874 | struct blk_mq_hw_ctx *hctx; | |
1875 | struct blk_mq_ctx *ctx; | |
2a34c087 | 1876 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 1877 | |
60de074b AM |
1878 | /* |
1879 | * Avoid others reading imcomplete hctx->cpumask through sysfs | |
1880 | */ | |
1881 | mutex_lock(&q->sysfs_lock); | |
1882 | ||
320ae51f | 1883 | queue_for_each_hw_ctx(q, hctx, i) { |
e4043dcf | 1884 | cpumask_clear(hctx->cpumask); |
320ae51f JA |
1885 | hctx->nr_ctx = 0; |
1886 | } | |
1887 | ||
1888 | /* | |
1889 | * Map software to hardware queues | |
1890 | */ | |
897bb0c7 | 1891 | for_each_possible_cpu(i) { |
320ae51f | 1892 | /* If the cpu isn't online, the cpu is mapped to first hctx */ |
5778322e | 1893 | if (!cpumask_test_cpu(i, online_mask)) |
e4043dcf JA |
1894 | continue; |
1895 | ||
897bb0c7 | 1896 | ctx = per_cpu_ptr(q->queue_ctx, i); |
7d7e0f90 | 1897 | hctx = blk_mq_map_queue(q, i); |
868f2f0b | 1898 | |
e4043dcf | 1899 | cpumask_set_cpu(i, hctx->cpumask); |
320ae51f JA |
1900 | ctx->index_hw = hctx->nr_ctx; |
1901 | hctx->ctxs[hctx->nr_ctx++] = ctx; | |
1902 | } | |
506e931f | 1903 | |
60de074b AM |
1904 | mutex_unlock(&q->sysfs_lock); |
1905 | ||
506e931f | 1906 | queue_for_each_hw_ctx(q, hctx, i) { |
484b4061 | 1907 | /* |
a68aafa5 JA |
1908 | * If no software queues are mapped to this hardware queue, |
1909 | * disable it and free the request entries. | |
484b4061 JA |
1910 | */ |
1911 | if (!hctx->nr_ctx) { | |
484b4061 JA |
1912 | if (set->tags[i]) { |
1913 | blk_mq_free_rq_map(set, set->tags[i], i); | |
1914 | set->tags[i] = NULL; | |
484b4061 | 1915 | } |
2a34c087 | 1916 | hctx->tags = NULL; |
484b4061 JA |
1917 | continue; |
1918 | } | |
1919 | ||
2a34c087 ML |
1920 | /* unmapped hw queue can be remapped after CPU topo changed */ |
1921 | if (!set->tags[i]) | |
1922 | set->tags[i] = blk_mq_init_rq_map(set, i); | |
1923 | hctx->tags = set->tags[i]; | |
1924 | WARN_ON(!hctx->tags); | |
1925 | ||
889fa31f CY |
1926 | /* |
1927 | * Set the map size to the number of mapped software queues. | |
1928 | * This is more accurate and more efficient than looping | |
1929 | * over all possibly mapped software queues. | |
1930 | */ | |
88459642 | 1931 | sbitmap_resize(&hctx->ctx_map, hctx->nr_ctx); |
889fa31f | 1932 | |
484b4061 JA |
1933 | /* |
1934 | * Initialize batch roundrobin counts | |
1935 | */ | |
506e931f JA |
1936 | hctx->next_cpu = cpumask_first(hctx->cpumask); |
1937 | hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; | |
1938 | } | |
320ae51f JA |
1939 | } |
1940 | ||
2404e607 | 1941 | static void queue_set_hctx_shared(struct request_queue *q, bool shared) |
0d2602ca JA |
1942 | { |
1943 | struct blk_mq_hw_ctx *hctx; | |
0d2602ca JA |
1944 | int i; |
1945 | ||
2404e607 JM |
1946 | queue_for_each_hw_ctx(q, hctx, i) { |
1947 | if (shared) | |
1948 | hctx->flags |= BLK_MQ_F_TAG_SHARED; | |
1949 | else | |
1950 | hctx->flags &= ~BLK_MQ_F_TAG_SHARED; | |
1951 | } | |
1952 | } | |
1953 | ||
1954 | static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set, bool shared) | |
1955 | { | |
1956 | struct request_queue *q; | |
0d2602ca JA |
1957 | |
1958 | list_for_each_entry(q, &set->tag_list, tag_set_list) { | |
1959 | blk_mq_freeze_queue(q); | |
2404e607 | 1960 | queue_set_hctx_shared(q, shared); |
0d2602ca JA |
1961 | blk_mq_unfreeze_queue(q); |
1962 | } | |
1963 | } | |
1964 | ||
1965 | static void blk_mq_del_queue_tag_set(struct request_queue *q) | |
1966 | { | |
1967 | struct blk_mq_tag_set *set = q->tag_set; | |
1968 | ||
0d2602ca JA |
1969 | mutex_lock(&set->tag_list_lock); |
1970 | list_del_init(&q->tag_set_list); | |
2404e607 JM |
1971 | if (list_is_singular(&set->tag_list)) { |
1972 | /* just transitioned to unshared */ | |
1973 | set->flags &= ~BLK_MQ_F_TAG_SHARED; | |
1974 | /* update existing queue */ | |
1975 | blk_mq_update_tag_set_depth(set, false); | |
1976 | } | |
0d2602ca | 1977 | mutex_unlock(&set->tag_list_lock); |
0d2602ca JA |
1978 | } |
1979 | ||
1980 | static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, | |
1981 | struct request_queue *q) | |
1982 | { | |
1983 | q->tag_set = set; | |
1984 | ||
1985 | mutex_lock(&set->tag_list_lock); | |
2404e607 JM |
1986 | |
1987 | /* Check to see if we're transitioning to shared (from 1 to 2 queues). */ | |
1988 | if (!list_empty(&set->tag_list) && !(set->flags & BLK_MQ_F_TAG_SHARED)) { | |
1989 | set->flags |= BLK_MQ_F_TAG_SHARED; | |
1990 | /* update existing queue */ | |
1991 | blk_mq_update_tag_set_depth(set, true); | |
1992 | } | |
1993 | if (set->flags & BLK_MQ_F_TAG_SHARED) | |
1994 | queue_set_hctx_shared(q, true); | |
0d2602ca | 1995 | list_add_tail(&q->tag_set_list, &set->tag_list); |
2404e607 | 1996 | |
0d2602ca JA |
1997 | mutex_unlock(&set->tag_list_lock); |
1998 | } | |
1999 | ||
e09aae7e ML |
2000 | /* |
2001 | * It is the actual release handler for mq, but we do it from | |
2002 | * request queue's release handler for avoiding use-after-free | |
2003 | * and headache because q->mq_kobj shouldn't have been introduced, | |
2004 | * but we can't group ctx/kctx kobj without it. | |
2005 | */ | |
2006 | void blk_mq_release(struct request_queue *q) | |
2007 | { | |
2008 | struct blk_mq_hw_ctx *hctx; | |
2009 | unsigned int i; | |
2010 | ||
2011 | /* hctx kobj stays in hctx */ | |
c3b4afca ML |
2012 | queue_for_each_hw_ctx(q, hctx, i) { |
2013 | if (!hctx) | |
2014 | continue; | |
2015 | kfree(hctx->ctxs); | |
e09aae7e | 2016 | kfree(hctx); |
c3b4afca | 2017 | } |
e09aae7e | 2018 | |
a723bab3 AM |
2019 | q->mq_map = NULL; |
2020 | ||
e09aae7e ML |
2021 | kfree(q->queue_hw_ctx); |
2022 | ||
2023 | /* ctx kobj stays in queue_ctx */ | |
2024 | free_percpu(q->queue_ctx); | |
2025 | } | |
2026 | ||
24d2f903 | 2027 | struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set) |
b62c21b7 MS |
2028 | { |
2029 | struct request_queue *uninit_q, *q; | |
2030 | ||
2031 | uninit_q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node); | |
2032 | if (!uninit_q) | |
2033 | return ERR_PTR(-ENOMEM); | |
2034 | ||
2035 | q = blk_mq_init_allocated_queue(set, uninit_q); | |
2036 | if (IS_ERR(q)) | |
2037 | blk_cleanup_queue(uninit_q); | |
2038 | ||
2039 | return q; | |
2040 | } | |
2041 | EXPORT_SYMBOL(blk_mq_init_queue); | |
2042 | ||
868f2f0b KB |
2043 | static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, |
2044 | struct request_queue *q) | |
320ae51f | 2045 | { |
868f2f0b KB |
2046 | int i, j; |
2047 | struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx; | |
f14bbe77 | 2048 | |
868f2f0b | 2049 | blk_mq_sysfs_unregister(q); |
24d2f903 | 2050 | for (i = 0; i < set->nr_hw_queues; i++) { |
868f2f0b | 2051 | int node; |
f14bbe77 | 2052 | |
868f2f0b KB |
2053 | if (hctxs[i]) |
2054 | continue; | |
2055 | ||
2056 | node = blk_mq_hw_queue_to_node(q->mq_map, i); | |
cdef54dd CH |
2057 | hctxs[i] = kzalloc_node(sizeof(struct blk_mq_hw_ctx), |
2058 | GFP_KERNEL, node); | |
320ae51f | 2059 | if (!hctxs[i]) |
868f2f0b | 2060 | break; |
320ae51f | 2061 | |
a86073e4 | 2062 | if (!zalloc_cpumask_var_node(&hctxs[i]->cpumask, GFP_KERNEL, |
868f2f0b KB |
2063 | node)) { |
2064 | kfree(hctxs[i]); | |
2065 | hctxs[i] = NULL; | |
2066 | break; | |
2067 | } | |
e4043dcf | 2068 | |
0d2602ca | 2069 | atomic_set(&hctxs[i]->nr_active, 0); |
f14bbe77 | 2070 | hctxs[i]->numa_node = node; |
320ae51f | 2071 | hctxs[i]->queue_num = i; |
868f2f0b KB |
2072 | |
2073 | if (blk_mq_init_hctx(q, set, hctxs[i], i)) { | |
2074 | free_cpumask_var(hctxs[i]->cpumask); | |
2075 | kfree(hctxs[i]); | |
2076 | hctxs[i] = NULL; | |
2077 | break; | |
2078 | } | |
2079 | blk_mq_hctx_kobj_init(hctxs[i]); | |
320ae51f | 2080 | } |
868f2f0b KB |
2081 | for (j = i; j < q->nr_hw_queues; j++) { |
2082 | struct blk_mq_hw_ctx *hctx = hctxs[j]; | |
2083 | ||
2084 | if (hctx) { | |
2085 | if (hctx->tags) { | |
2086 | blk_mq_free_rq_map(set, hctx->tags, j); | |
2087 | set->tags[j] = NULL; | |
2088 | } | |
2089 | blk_mq_exit_hctx(q, set, hctx, j); | |
2090 | free_cpumask_var(hctx->cpumask); | |
2091 | kobject_put(&hctx->kobj); | |
2092 | kfree(hctx->ctxs); | |
2093 | kfree(hctx); | |
2094 | hctxs[j] = NULL; | |
2095 | ||
2096 | } | |
2097 | } | |
2098 | q->nr_hw_queues = i; | |
2099 | blk_mq_sysfs_register(q); | |
2100 | } | |
2101 | ||
2102 | struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, | |
2103 | struct request_queue *q) | |
2104 | { | |
66841672 ML |
2105 | /* mark the queue as mq asap */ |
2106 | q->mq_ops = set->ops; | |
2107 | ||
868f2f0b KB |
2108 | q->queue_ctx = alloc_percpu(struct blk_mq_ctx); |
2109 | if (!q->queue_ctx) | |
c7de5726 | 2110 | goto err_exit; |
868f2f0b KB |
2111 | |
2112 | q->queue_hw_ctx = kzalloc_node(nr_cpu_ids * sizeof(*(q->queue_hw_ctx)), | |
2113 | GFP_KERNEL, set->numa_node); | |
2114 | if (!q->queue_hw_ctx) | |
2115 | goto err_percpu; | |
2116 | ||
bdd17e75 | 2117 | q->mq_map = set->mq_map; |
868f2f0b KB |
2118 | |
2119 | blk_mq_realloc_hw_ctxs(set, q); | |
2120 | if (!q->nr_hw_queues) | |
2121 | goto err_hctxs; | |
320ae51f | 2122 | |
287922eb | 2123 | INIT_WORK(&q->timeout_work, blk_mq_timeout_work); |
e56f698b | 2124 | blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ); |
320ae51f JA |
2125 | |
2126 | q->nr_queues = nr_cpu_ids; | |
320ae51f | 2127 | |
94eddfbe | 2128 | q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT; |
320ae51f | 2129 | |
05f1dd53 JA |
2130 | if (!(set->flags & BLK_MQ_F_SG_MERGE)) |
2131 | q->queue_flags |= 1 << QUEUE_FLAG_NO_SG_MERGE; | |
2132 | ||
1be036e9 CH |
2133 | q->sg_reserved_size = INT_MAX; |
2134 | ||
2849450a | 2135 | INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work); |
6fca6a61 CH |
2136 | INIT_LIST_HEAD(&q->requeue_list); |
2137 | spin_lock_init(&q->requeue_lock); | |
2138 | ||
07068d5b JA |
2139 | if (q->nr_hw_queues > 1) |
2140 | blk_queue_make_request(q, blk_mq_make_request); | |
2141 | else | |
2142 | blk_queue_make_request(q, blk_sq_make_request); | |
2143 | ||
eba71768 JA |
2144 | /* |
2145 | * Do this after blk_queue_make_request() overrides it... | |
2146 | */ | |
2147 | q->nr_requests = set->queue_depth; | |
2148 | ||
64f1c21e JA |
2149 | /* |
2150 | * Default to classic polling | |
2151 | */ | |
2152 | q->poll_nsec = -1; | |
2153 | ||
24d2f903 CH |
2154 | if (set->ops->complete) |
2155 | blk_queue_softirq_done(q, set->ops->complete); | |
30a91cb4 | 2156 | |
24d2f903 | 2157 | blk_mq_init_cpu_queues(q, set->nr_hw_queues); |
320ae51f | 2158 | |
5778322e | 2159 | get_online_cpus(); |
320ae51f | 2160 | mutex_lock(&all_q_mutex); |
320ae51f | 2161 | |
4593fdbe | 2162 | list_add_tail(&q->all_q_node, &all_q_list); |
0d2602ca | 2163 | blk_mq_add_queue_tag_set(set, q); |
5778322e | 2164 | blk_mq_map_swqueue(q, cpu_online_mask); |
484b4061 | 2165 | |
4593fdbe | 2166 | mutex_unlock(&all_q_mutex); |
5778322e | 2167 | put_online_cpus(); |
4593fdbe | 2168 | |
320ae51f | 2169 | return q; |
18741986 | 2170 | |
320ae51f | 2171 | err_hctxs: |
868f2f0b | 2172 | kfree(q->queue_hw_ctx); |
320ae51f | 2173 | err_percpu: |
868f2f0b | 2174 | free_percpu(q->queue_ctx); |
c7de5726 ML |
2175 | err_exit: |
2176 | q->mq_ops = NULL; | |
320ae51f JA |
2177 | return ERR_PTR(-ENOMEM); |
2178 | } | |
b62c21b7 | 2179 | EXPORT_SYMBOL(blk_mq_init_allocated_queue); |
320ae51f JA |
2180 | |
2181 | void blk_mq_free_queue(struct request_queue *q) | |
2182 | { | |
624dbe47 | 2183 | struct blk_mq_tag_set *set = q->tag_set; |
320ae51f | 2184 | |
0e626368 AM |
2185 | mutex_lock(&all_q_mutex); |
2186 | list_del_init(&q->all_q_node); | |
2187 | mutex_unlock(&all_q_mutex); | |
2188 | ||
87760e5e JA |
2189 | wbt_exit(q); |
2190 | ||
0d2602ca JA |
2191 | blk_mq_del_queue_tag_set(q); |
2192 | ||
624dbe47 ML |
2193 | blk_mq_exit_hw_queues(q, set, set->nr_hw_queues); |
2194 | blk_mq_free_hw_queues(q, set); | |
320ae51f | 2195 | } |
320ae51f JA |
2196 | |
2197 | /* Basically redo blk_mq_init_queue with queue frozen */ | |
5778322e AM |
2198 | static void blk_mq_queue_reinit(struct request_queue *q, |
2199 | const struct cpumask *online_mask) | |
320ae51f | 2200 | { |
4ecd4fef | 2201 | WARN_ON_ONCE(!atomic_read(&q->mq_freeze_depth)); |
320ae51f | 2202 | |
67aec14c JA |
2203 | blk_mq_sysfs_unregister(q); |
2204 | ||
320ae51f JA |
2205 | /* |
2206 | * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe | |
2207 | * we should change hctx numa_node according to new topology (this | |
2208 | * involves free and re-allocate memory, worthy doing?) | |
2209 | */ | |
2210 | ||
5778322e | 2211 | blk_mq_map_swqueue(q, online_mask); |
320ae51f | 2212 | |
67aec14c | 2213 | blk_mq_sysfs_register(q); |
320ae51f JA |
2214 | } |
2215 | ||
65d5291e SAS |
2216 | /* |
2217 | * New online cpumask which is going to be set in this hotplug event. | |
2218 | * Declare this cpumasks as global as cpu-hotplug operation is invoked | |
2219 | * one-by-one and dynamically allocating this could result in a failure. | |
2220 | */ | |
2221 | static struct cpumask cpuhp_online_new; | |
2222 | ||
2223 | static void blk_mq_queue_reinit_work(void) | |
320ae51f JA |
2224 | { |
2225 | struct request_queue *q; | |
320ae51f JA |
2226 | |
2227 | mutex_lock(&all_q_mutex); | |
f3af020b TH |
2228 | /* |
2229 | * We need to freeze and reinit all existing queues. Freezing | |
2230 | * involves synchronous wait for an RCU grace period and doing it | |
2231 | * one by one may take a long time. Start freezing all queues in | |
2232 | * one swoop and then wait for the completions so that freezing can | |
2233 | * take place in parallel. | |
2234 | */ | |
2235 | list_for_each_entry(q, &all_q_list, all_q_node) | |
2236 | blk_mq_freeze_queue_start(q); | |
415d3dab | 2237 | list_for_each_entry(q, &all_q_list, all_q_node) |
f3af020b TH |
2238 | blk_mq_freeze_queue_wait(q); |
2239 | ||
320ae51f | 2240 | list_for_each_entry(q, &all_q_list, all_q_node) |
65d5291e | 2241 | blk_mq_queue_reinit(q, &cpuhp_online_new); |
f3af020b TH |
2242 | |
2243 | list_for_each_entry(q, &all_q_list, all_q_node) | |
2244 | blk_mq_unfreeze_queue(q); | |
2245 | ||
320ae51f | 2246 | mutex_unlock(&all_q_mutex); |
65d5291e SAS |
2247 | } |
2248 | ||
2249 | static int blk_mq_queue_reinit_dead(unsigned int cpu) | |
2250 | { | |
97a32864 | 2251 | cpumask_copy(&cpuhp_online_new, cpu_online_mask); |
65d5291e SAS |
2252 | blk_mq_queue_reinit_work(); |
2253 | return 0; | |
2254 | } | |
2255 | ||
2256 | /* | |
2257 | * Before hotadded cpu starts handling requests, new mappings must be | |
2258 | * established. Otherwise, these requests in hw queue might never be | |
2259 | * dispatched. | |
2260 | * | |
2261 | * For example, there is a single hw queue (hctx) and two CPU queues (ctx0 | |
2262 | * for CPU0, and ctx1 for CPU1). | |
2263 | * | |
2264 | * Now CPU1 is just onlined and a request is inserted into ctx1->rq_list | |
2265 | * and set bit0 in pending bitmap as ctx1->index_hw is still zero. | |
2266 | * | |
2267 | * And then while running hw queue, flush_busy_ctxs() finds bit0 is set in | |
2268 | * pending bitmap and tries to retrieve requests in hctx->ctxs[0]->rq_list. | |
2269 | * But htx->ctxs[0] is a pointer to ctx0, so the request in ctx1->rq_list | |
2270 | * is ignored. | |
2271 | */ | |
2272 | static int blk_mq_queue_reinit_prepare(unsigned int cpu) | |
2273 | { | |
2274 | cpumask_copy(&cpuhp_online_new, cpu_online_mask); | |
2275 | cpumask_set_cpu(cpu, &cpuhp_online_new); | |
2276 | blk_mq_queue_reinit_work(); | |
2277 | return 0; | |
320ae51f JA |
2278 | } |
2279 | ||
a5164405 JA |
2280 | static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) |
2281 | { | |
2282 | int i; | |
2283 | ||
2284 | for (i = 0; i < set->nr_hw_queues; i++) { | |
2285 | set->tags[i] = blk_mq_init_rq_map(set, i); | |
2286 | if (!set->tags[i]) | |
2287 | goto out_unwind; | |
2288 | } | |
2289 | ||
2290 | return 0; | |
2291 | ||
2292 | out_unwind: | |
2293 | while (--i >= 0) | |
2294 | blk_mq_free_rq_map(set, set->tags[i], i); | |
2295 | ||
a5164405 JA |
2296 | return -ENOMEM; |
2297 | } | |
2298 | ||
2299 | /* | |
2300 | * Allocate the request maps associated with this tag_set. Note that this | |
2301 | * may reduce the depth asked for, if memory is tight. set->queue_depth | |
2302 | * will be updated to reflect the allocated depth. | |
2303 | */ | |
2304 | static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set) | |
2305 | { | |
2306 | unsigned int depth; | |
2307 | int err; | |
2308 | ||
2309 | depth = set->queue_depth; | |
2310 | do { | |
2311 | err = __blk_mq_alloc_rq_maps(set); | |
2312 | if (!err) | |
2313 | break; | |
2314 | ||
2315 | set->queue_depth >>= 1; | |
2316 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) { | |
2317 | err = -ENOMEM; | |
2318 | break; | |
2319 | } | |
2320 | } while (set->queue_depth); | |
2321 | ||
2322 | if (!set->queue_depth || err) { | |
2323 | pr_err("blk-mq: failed to allocate request map\n"); | |
2324 | return -ENOMEM; | |
2325 | } | |
2326 | ||
2327 | if (depth != set->queue_depth) | |
2328 | pr_info("blk-mq: reduced tag depth (%u -> %u)\n", | |
2329 | depth, set->queue_depth); | |
2330 | ||
2331 | return 0; | |
2332 | } | |
2333 | ||
a4391c64 JA |
2334 | /* |
2335 | * Alloc a tag set to be associated with one or more request queues. | |
2336 | * May fail with EINVAL for various error conditions. May adjust the | |
2337 | * requested depth down, if if it too large. In that case, the set | |
2338 | * value will be stored in set->queue_depth. | |
2339 | */ | |
24d2f903 CH |
2340 | int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set) |
2341 | { | |
da695ba2 CH |
2342 | int ret; |
2343 | ||
205fb5f5 BVA |
2344 | BUILD_BUG_ON(BLK_MQ_MAX_DEPTH > 1 << BLK_MQ_UNIQUE_TAG_BITS); |
2345 | ||
24d2f903 CH |
2346 | if (!set->nr_hw_queues) |
2347 | return -EINVAL; | |
a4391c64 | 2348 | if (!set->queue_depth) |
24d2f903 CH |
2349 | return -EINVAL; |
2350 | if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) | |
2351 | return -EINVAL; | |
2352 | ||
7d7e0f90 | 2353 | if (!set->ops->queue_rq) |
24d2f903 CH |
2354 | return -EINVAL; |
2355 | ||
a4391c64 JA |
2356 | if (set->queue_depth > BLK_MQ_MAX_DEPTH) { |
2357 | pr_info("blk-mq: reduced tag depth to %u\n", | |
2358 | BLK_MQ_MAX_DEPTH); | |
2359 | set->queue_depth = BLK_MQ_MAX_DEPTH; | |
2360 | } | |
24d2f903 | 2361 | |
6637fadf SL |
2362 | /* |
2363 | * If a crashdump is active, then we are potentially in a very | |
2364 | * memory constrained environment. Limit us to 1 queue and | |
2365 | * 64 tags to prevent using too much memory. | |
2366 | */ | |
2367 | if (is_kdump_kernel()) { | |
2368 | set->nr_hw_queues = 1; | |
2369 | set->queue_depth = min(64U, set->queue_depth); | |
2370 | } | |
868f2f0b KB |
2371 | /* |
2372 | * There is no use for more h/w queues than cpus. | |
2373 | */ | |
2374 | if (set->nr_hw_queues > nr_cpu_ids) | |
2375 | set->nr_hw_queues = nr_cpu_ids; | |
6637fadf | 2376 | |
868f2f0b | 2377 | set->tags = kzalloc_node(nr_cpu_ids * sizeof(struct blk_mq_tags *), |
24d2f903 CH |
2378 | GFP_KERNEL, set->numa_node); |
2379 | if (!set->tags) | |
a5164405 | 2380 | return -ENOMEM; |
24d2f903 | 2381 | |
da695ba2 CH |
2382 | ret = -ENOMEM; |
2383 | set->mq_map = kzalloc_node(sizeof(*set->mq_map) * nr_cpu_ids, | |
2384 | GFP_KERNEL, set->numa_node); | |
bdd17e75 CH |
2385 | if (!set->mq_map) |
2386 | goto out_free_tags; | |
2387 | ||
da695ba2 CH |
2388 | if (set->ops->map_queues) |
2389 | ret = set->ops->map_queues(set); | |
2390 | else | |
2391 | ret = blk_mq_map_queues(set); | |
2392 | if (ret) | |
2393 | goto out_free_mq_map; | |
2394 | ||
2395 | ret = blk_mq_alloc_rq_maps(set); | |
2396 | if (ret) | |
bdd17e75 | 2397 | goto out_free_mq_map; |
24d2f903 | 2398 | |
0d2602ca JA |
2399 | mutex_init(&set->tag_list_lock); |
2400 | INIT_LIST_HEAD(&set->tag_list); | |
2401 | ||
24d2f903 | 2402 | return 0; |
bdd17e75 CH |
2403 | |
2404 | out_free_mq_map: | |
2405 | kfree(set->mq_map); | |
2406 | set->mq_map = NULL; | |
2407 | out_free_tags: | |
5676e7b6 RE |
2408 | kfree(set->tags); |
2409 | set->tags = NULL; | |
da695ba2 | 2410 | return ret; |
24d2f903 CH |
2411 | } |
2412 | EXPORT_SYMBOL(blk_mq_alloc_tag_set); | |
2413 | ||
2414 | void blk_mq_free_tag_set(struct blk_mq_tag_set *set) | |
2415 | { | |
2416 | int i; | |
2417 | ||
868f2f0b | 2418 | for (i = 0; i < nr_cpu_ids; i++) { |
f42d79ab | 2419 | if (set->tags[i]) |
484b4061 JA |
2420 | blk_mq_free_rq_map(set, set->tags[i], i); |
2421 | } | |
2422 | ||
bdd17e75 CH |
2423 | kfree(set->mq_map); |
2424 | set->mq_map = NULL; | |
2425 | ||
981bd189 | 2426 | kfree(set->tags); |
5676e7b6 | 2427 | set->tags = NULL; |
24d2f903 CH |
2428 | } |
2429 | EXPORT_SYMBOL(blk_mq_free_tag_set); | |
2430 | ||
e3a2b3f9 JA |
2431 | int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr) |
2432 | { | |
2433 | struct blk_mq_tag_set *set = q->tag_set; | |
2434 | struct blk_mq_hw_ctx *hctx; | |
2435 | int i, ret; | |
2436 | ||
2437 | if (!set || nr > set->queue_depth) | |
2438 | return -EINVAL; | |
2439 | ||
2440 | ret = 0; | |
2441 | queue_for_each_hw_ctx(q, hctx, i) { | |
e9137d4b KB |
2442 | if (!hctx->tags) |
2443 | continue; | |
e3a2b3f9 JA |
2444 | ret = blk_mq_tag_update_depth(hctx->tags, nr); |
2445 | if (ret) | |
2446 | break; | |
2447 | } | |
2448 | ||
2449 | if (!ret) | |
2450 | q->nr_requests = nr; | |
2451 | ||
2452 | return ret; | |
2453 | } | |
2454 | ||
868f2f0b KB |
2455 | void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues) |
2456 | { | |
2457 | struct request_queue *q; | |
2458 | ||
2459 | if (nr_hw_queues > nr_cpu_ids) | |
2460 | nr_hw_queues = nr_cpu_ids; | |
2461 | if (nr_hw_queues < 1 || nr_hw_queues == set->nr_hw_queues) | |
2462 | return; | |
2463 | ||
2464 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
2465 | blk_mq_freeze_queue(q); | |
2466 | ||
2467 | set->nr_hw_queues = nr_hw_queues; | |
2468 | list_for_each_entry(q, &set->tag_list, tag_set_list) { | |
2469 | blk_mq_realloc_hw_ctxs(set, q); | |
2470 | ||
2471 | if (q->nr_hw_queues > 1) | |
2472 | blk_queue_make_request(q, blk_mq_make_request); | |
2473 | else | |
2474 | blk_queue_make_request(q, blk_sq_make_request); | |
2475 | ||
2476 | blk_mq_queue_reinit(q, cpu_online_mask); | |
2477 | } | |
2478 | ||
2479 | list_for_each_entry(q, &set->tag_list, tag_set_list) | |
2480 | blk_mq_unfreeze_queue(q); | |
2481 | } | |
2482 | EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues); | |
2483 | ||
64f1c21e JA |
2484 | static unsigned long blk_mq_poll_nsecs(struct request_queue *q, |
2485 | struct blk_mq_hw_ctx *hctx, | |
2486 | struct request *rq) | |
2487 | { | |
2488 | struct blk_rq_stat stat[2]; | |
2489 | unsigned long ret = 0; | |
2490 | ||
2491 | /* | |
2492 | * If stats collection isn't on, don't sleep but turn it on for | |
2493 | * future users | |
2494 | */ | |
2495 | if (!blk_stat_enable(q)) | |
2496 | return 0; | |
2497 | ||
2498 | /* | |
2499 | * We don't have to do this once per IO, should optimize this | |
2500 | * to just use the current window of stats until it changes | |
2501 | */ | |
2502 | memset(&stat, 0, sizeof(stat)); | |
2503 | blk_hctx_stat_get(hctx, stat); | |
2504 | ||
2505 | /* | |
2506 | * As an optimistic guess, use half of the mean service time | |
2507 | * for this type of request. We can (and should) make this smarter. | |
2508 | * For instance, if the completion latencies are tight, we can | |
2509 | * get closer than just half the mean. This is especially | |
2510 | * important on devices where the completion latencies are longer | |
2511 | * than ~10 usec. | |
2512 | */ | |
2513 | if (req_op(rq) == REQ_OP_READ && stat[BLK_STAT_READ].nr_samples) | |
2514 | ret = (stat[BLK_STAT_READ].mean + 1) / 2; | |
2515 | else if (req_op(rq) == REQ_OP_WRITE && stat[BLK_STAT_WRITE].nr_samples) | |
2516 | ret = (stat[BLK_STAT_WRITE].mean + 1) / 2; | |
2517 | ||
2518 | return ret; | |
2519 | } | |
2520 | ||
06426adf | 2521 | static bool blk_mq_poll_hybrid_sleep(struct request_queue *q, |
64f1c21e | 2522 | struct blk_mq_hw_ctx *hctx, |
06426adf JA |
2523 | struct request *rq) |
2524 | { | |
2525 | struct hrtimer_sleeper hs; | |
2526 | enum hrtimer_mode mode; | |
64f1c21e | 2527 | unsigned int nsecs; |
06426adf JA |
2528 | ktime_t kt; |
2529 | ||
64f1c21e JA |
2530 | if (test_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags)) |
2531 | return false; | |
2532 | ||
2533 | /* | |
2534 | * poll_nsec can be: | |
2535 | * | |
2536 | * -1: don't ever hybrid sleep | |
2537 | * 0: use half of prev avg | |
2538 | * >0: use this specific value | |
2539 | */ | |
2540 | if (q->poll_nsec == -1) | |
2541 | return false; | |
2542 | else if (q->poll_nsec > 0) | |
2543 | nsecs = q->poll_nsec; | |
2544 | else | |
2545 | nsecs = blk_mq_poll_nsecs(q, hctx, rq); | |
2546 | ||
2547 | if (!nsecs) | |
06426adf JA |
2548 | return false; |
2549 | ||
2550 | set_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags); | |
2551 | ||
2552 | /* | |
2553 | * This will be replaced with the stats tracking code, using | |
2554 | * 'avg_completion_time / 2' as the pre-sleep target. | |
2555 | */ | |
64f1c21e | 2556 | kt = ktime_set(0, nsecs); |
06426adf JA |
2557 | |
2558 | mode = HRTIMER_MODE_REL; | |
2559 | hrtimer_init_on_stack(&hs.timer, CLOCK_MONOTONIC, mode); | |
2560 | hrtimer_set_expires(&hs.timer, kt); | |
2561 | ||
2562 | hrtimer_init_sleeper(&hs, current); | |
2563 | do { | |
2564 | if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) | |
2565 | break; | |
2566 | set_current_state(TASK_UNINTERRUPTIBLE); | |
2567 | hrtimer_start_expires(&hs.timer, mode); | |
2568 | if (hs.task) | |
2569 | io_schedule(); | |
2570 | hrtimer_cancel(&hs.timer); | |
2571 | mode = HRTIMER_MODE_ABS; | |
2572 | } while (hs.task && !signal_pending(current)); | |
2573 | ||
2574 | __set_current_state(TASK_RUNNING); | |
2575 | destroy_hrtimer_on_stack(&hs.timer); | |
2576 | return true; | |
2577 | } | |
2578 | ||
bbd7bb70 JA |
2579 | static bool __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq) |
2580 | { | |
2581 | struct request_queue *q = hctx->queue; | |
2582 | long state; | |
2583 | ||
06426adf JA |
2584 | /* |
2585 | * If we sleep, have the caller restart the poll loop to reset | |
2586 | * the state. Like for the other success return cases, the | |
2587 | * caller is responsible for checking if the IO completed. If | |
2588 | * the IO isn't complete, we'll get called again and will go | |
2589 | * straight to the busy poll loop. | |
2590 | */ | |
64f1c21e | 2591 | if (blk_mq_poll_hybrid_sleep(q, hctx, rq)) |
06426adf JA |
2592 | return true; |
2593 | ||
bbd7bb70 JA |
2594 | hctx->poll_considered++; |
2595 | ||
2596 | state = current->state; | |
2597 | while (!need_resched()) { | |
2598 | int ret; | |
2599 | ||
2600 | hctx->poll_invoked++; | |
2601 | ||
2602 | ret = q->mq_ops->poll(hctx, rq->tag); | |
2603 | if (ret > 0) { | |
2604 | hctx->poll_success++; | |
2605 | set_current_state(TASK_RUNNING); | |
2606 | return true; | |
2607 | } | |
2608 | ||
2609 | if (signal_pending_state(state, current)) | |
2610 | set_current_state(TASK_RUNNING); | |
2611 | ||
2612 | if (current->state == TASK_RUNNING) | |
2613 | return true; | |
2614 | if (ret < 0) | |
2615 | break; | |
2616 | cpu_relax(); | |
2617 | } | |
2618 | ||
2619 | return false; | |
2620 | } | |
2621 | ||
2622 | bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie) | |
2623 | { | |
2624 | struct blk_mq_hw_ctx *hctx; | |
2625 | struct blk_plug *plug; | |
2626 | struct request *rq; | |
2627 | ||
2628 | if (!q->mq_ops || !q->mq_ops->poll || !blk_qc_t_valid(cookie) || | |
2629 | !test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) | |
2630 | return false; | |
2631 | ||
2632 | plug = current->plug; | |
2633 | if (plug) | |
2634 | blk_flush_plug_list(plug, false); | |
2635 | ||
2636 | hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)]; | |
2637 | rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie)); | |
2638 | ||
2639 | return __blk_mq_poll(hctx, rq); | |
2640 | } | |
2641 | EXPORT_SYMBOL_GPL(blk_mq_poll); | |
2642 | ||
676141e4 JA |
2643 | void blk_mq_disable_hotplug(void) |
2644 | { | |
2645 | mutex_lock(&all_q_mutex); | |
2646 | } | |
2647 | ||
2648 | void blk_mq_enable_hotplug(void) | |
2649 | { | |
2650 | mutex_unlock(&all_q_mutex); | |
2651 | } | |
2652 | ||
320ae51f JA |
2653 | static int __init blk_mq_init(void) |
2654 | { | |
9467f859 TG |
2655 | cpuhp_setup_state_multi(CPUHP_BLK_MQ_DEAD, "block/mq:dead", NULL, |
2656 | blk_mq_hctx_notify_dead); | |
320ae51f | 2657 | |
65d5291e SAS |
2658 | cpuhp_setup_state_nocalls(CPUHP_BLK_MQ_PREPARE, "block/mq:prepare", |
2659 | blk_mq_queue_reinit_prepare, | |
2660 | blk_mq_queue_reinit_dead); | |
320ae51f JA |
2661 | return 0; |
2662 | } | |
2663 | subsys_initcall(blk_mq_init); |