Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
1da177e4 LT |
2 | * Copyright (C) 1991, 1992 Linus Torvalds |
3 | * Copyright (C) 1994, Karl Keyte: Added support for disk statistics | |
4 | * Elevator latency, (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE | |
5 | * Queue request tables / lock, selectable elevator, Jens Axboe <axboe@suse.de> | |
6728cb0e JA |
6 | * kernel-doc documentation started by NeilBrown <neilb@cse.unsw.edu.au> |
7 | * - July2000 | |
1da177e4 LT |
8 | * bio rewrite, highmem i/o, etc, Jens Axboe <axboe@suse.de> - may 2001 |
9 | */ | |
10 | ||
11 | /* | |
12 | * This handles all read/write requests to block devices | |
13 | */ | |
1da177e4 LT |
14 | #include <linux/kernel.h> |
15 | #include <linux/module.h> | |
16 | #include <linux/backing-dev.h> | |
17 | #include <linux/bio.h> | |
18 | #include <linux/blkdev.h> | |
320ae51f | 19 | #include <linux/blk-mq.h> |
1da177e4 LT |
20 | #include <linux/highmem.h> |
21 | #include <linux/mm.h> | |
22 | #include <linux/kernel_stat.h> | |
23 | #include <linux/string.h> | |
24 | #include <linux/init.h> | |
1da177e4 LT |
25 | #include <linux/completion.h> |
26 | #include <linux/slab.h> | |
27 | #include <linux/swap.h> | |
28 | #include <linux/writeback.h> | |
faccbd4b | 29 | #include <linux/task_io_accounting_ops.h> |
c17bb495 | 30 | #include <linux/fault-inject.h> |
73c10101 | 31 | #include <linux/list_sort.h> |
e3c78ca5 | 32 | #include <linux/delay.h> |
aaf7c680 | 33 | #include <linux/ratelimit.h> |
6c954667 | 34 | #include <linux/pm_runtime.h> |
eea8f41c | 35 | #include <linux/blk-cgroup.h> |
18fbda91 | 36 | #include <linux/debugfs.h> |
55782138 LZ |
37 | |
38 | #define CREATE_TRACE_POINTS | |
39 | #include <trace/events/block.h> | |
1da177e4 | 40 | |
8324aa91 | 41 | #include "blk.h" |
43a5e4e2 | 42 | #include "blk-mq.h" |
bd166ef1 | 43 | #include "blk-mq-sched.h" |
87760e5e | 44 | #include "blk-wbt.h" |
8324aa91 | 45 | |
18fbda91 OS |
46 | #ifdef CONFIG_DEBUG_FS |
47 | struct dentry *blk_debugfs_root; | |
48 | #endif | |
49 | ||
d07335e5 | 50 | EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap); |
b0da3f0d | 51 | EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap); |
0a82a8d1 | 52 | EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_complete); |
3291fa57 | 53 | EXPORT_TRACEPOINT_SYMBOL_GPL(block_split); |
cbae8d45 | 54 | EXPORT_TRACEPOINT_SYMBOL_GPL(block_unplug); |
0bfc2455 | 55 | |
a73f730d TH |
56 | DEFINE_IDA(blk_queue_ida); |
57 | ||
1da177e4 LT |
58 | /* |
59 | * For the allocated request tables | |
60 | */ | |
d674d414 | 61 | struct kmem_cache *request_cachep; |
1da177e4 LT |
62 | |
63 | /* | |
64 | * For queue allocation | |
65 | */ | |
6728cb0e | 66 | struct kmem_cache *blk_requestq_cachep; |
1da177e4 | 67 | |
1da177e4 LT |
68 | /* |
69 | * Controlling structure to kblockd | |
70 | */ | |
ff856bad | 71 | static struct workqueue_struct *kblockd_workqueue; |
1da177e4 | 72 | |
d40f75a0 TH |
73 | static void blk_clear_congested(struct request_list *rl, int sync) |
74 | { | |
d40f75a0 TH |
75 | #ifdef CONFIG_CGROUP_WRITEBACK |
76 | clear_wb_congested(rl->blkg->wb_congested, sync); | |
77 | #else | |
482cf79c TH |
78 | /* |
79 | * If !CGROUP_WRITEBACK, all blkg's map to bdi->wb and we shouldn't | |
80 | * flip its congestion state for events on other blkcgs. | |
81 | */ | |
82 | if (rl == &rl->q->root_rl) | |
dc3b17cc | 83 | clear_wb_congested(rl->q->backing_dev_info->wb.congested, sync); |
d40f75a0 TH |
84 | #endif |
85 | } | |
86 | ||
87 | static void blk_set_congested(struct request_list *rl, int sync) | |
88 | { | |
d40f75a0 TH |
89 | #ifdef CONFIG_CGROUP_WRITEBACK |
90 | set_wb_congested(rl->blkg->wb_congested, sync); | |
91 | #else | |
482cf79c TH |
92 | /* see blk_clear_congested() */ |
93 | if (rl == &rl->q->root_rl) | |
dc3b17cc | 94 | set_wb_congested(rl->q->backing_dev_info->wb.congested, sync); |
d40f75a0 TH |
95 | #endif |
96 | } | |
97 | ||
8324aa91 | 98 | void blk_queue_congestion_threshold(struct request_queue *q) |
1da177e4 LT |
99 | { |
100 | int nr; | |
101 | ||
102 | nr = q->nr_requests - (q->nr_requests / 8) + 1; | |
103 | if (nr > q->nr_requests) | |
104 | nr = q->nr_requests; | |
105 | q->nr_congestion_on = nr; | |
106 | ||
107 | nr = q->nr_requests - (q->nr_requests / 8) - (q->nr_requests / 16) - 1; | |
108 | if (nr < 1) | |
109 | nr = 1; | |
110 | q->nr_congestion_off = nr; | |
111 | } | |
112 | ||
2a4aa30c | 113 | void blk_rq_init(struct request_queue *q, struct request *rq) |
1da177e4 | 114 | { |
1afb20f3 FT |
115 | memset(rq, 0, sizeof(*rq)); |
116 | ||
1da177e4 | 117 | INIT_LIST_HEAD(&rq->queuelist); |
242f9dcb | 118 | INIT_LIST_HEAD(&rq->timeout_list); |
c7c22e4d | 119 | rq->cpu = -1; |
63a71386 | 120 | rq->q = q; |
a2dec7b3 | 121 | rq->__sector = (sector_t) -1; |
2e662b65 JA |
122 | INIT_HLIST_NODE(&rq->hash); |
123 | RB_CLEAR_NODE(&rq->rb_node); | |
63a71386 | 124 | rq->tag = -1; |
bd166ef1 | 125 | rq->internal_tag = -1; |
b243ddcb | 126 | rq->start_time = jiffies; |
9195291e | 127 | set_start_time_ns(rq); |
09e099d4 | 128 | rq->part = NULL; |
1da177e4 | 129 | } |
2a4aa30c | 130 | EXPORT_SYMBOL(blk_rq_init); |
1da177e4 | 131 | |
5bb23a68 N |
132 | static void req_bio_endio(struct request *rq, struct bio *bio, |
133 | unsigned int nbytes, int error) | |
1da177e4 | 134 | { |
78d8e58a | 135 | if (error) |
4246a0b6 | 136 | bio->bi_error = error; |
797e7dbb | 137 | |
e8064021 | 138 | if (unlikely(rq->rq_flags & RQF_QUIET)) |
b7c44ed9 | 139 | bio_set_flag(bio, BIO_QUIET); |
08bafc03 | 140 | |
f79ea416 | 141 | bio_advance(bio, nbytes); |
7ba1ba12 | 142 | |
143a87f4 | 143 | /* don't actually finish bio if it's part of flush sequence */ |
e8064021 | 144 | if (bio->bi_iter.bi_size == 0 && !(rq->rq_flags & RQF_FLUSH_SEQ)) |
4246a0b6 | 145 | bio_endio(bio); |
1da177e4 | 146 | } |
1da177e4 | 147 | |
1da177e4 LT |
148 | void blk_dump_rq_flags(struct request *rq, char *msg) |
149 | { | |
aebf526b CH |
150 | printk(KERN_INFO "%s: dev %s: flags=%llx\n", msg, |
151 | rq->rq_disk ? rq->rq_disk->disk_name : "?", | |
5953316d | 152 | (unsigned long long) rq->cmd_flags); |
1da177e4 | 153 | |
83096ebf TH |
154 | printk(KERN_INFO " sector %llu, nr/cnr %u/%u\n", |
155 | (unsigned long long)blk_rq_pos(rq), | |
156 | blk_rq_sectors(rq), blk_rq_cur_sectors(rq)); | |
b4f42e28 JA |
157 | printk(KERN_INFO " bio %p, biotail %p, len %u\n", |
158 | rq->bio, rq->biotail, blk_rq_bytes(rq)); | |
1da177e4 | 159 | } |
1da177e4 LT |
160 | EXPORT_SYMBOL(blk_dump_rq_flags); |
161 | ||
3cca6dc1 | 162 | static void blk_delay_work(struct work_struct *work) |
1da177e4 | 163 | { |
3cca6dc1 | 164 | struct request_queue *q; |
1da177e4 | 165 | |
3cca6dc1 JA |
166 | q = container_of(work, struct request_queue, delay_work.work); |
167 | spin_lock_irq(q->queue_lock); | |
24ecfbe2 | 168 | __blk_run_queue(q); |
3cca6dc1 | 169 | spin_unlock_irq(q->queue_lock); |
1da177e4 | 170 | } |
1da177e4 LT |
171 | |
172 | /** | |
3cca6dc1 JA |
173 | * blk_delay_queue - restart queueing after defined interval |
174 | * @q: The &struct request_queue in question | |
175 | * @msecs: Delay in msecs | |
1da177e4 LT |
176 | * |
177 | * Description: | |
3cca6dc1 JA |
178 | * Sometimes queueing needs to be postponed for a little while, to allow |
179 | * resources to come back. This function will make sure that queueing is | |
70460571 | 180 | * restarted around the specified time. Queue lock must be held. |
3cca6dc1 JA |
181 | */ |
182 | void blk_delay_queue(struct request_queue *q, unsigned long msecs) | |
2ad8b1ef | 183 | { |
70460571 BVA |
184 | if (likely(!blk_queue_dead(q))) |
185 | queue_delayed_work(kblockd_workqueue, &q->delay_work, | |
186 | msecs_to_jiffies(msecs)); | |
2ad8b1ef | 187 | } |
3cca6dc1 | 188 | EXPORT_SYMBOL(blk_delay_queue); |
2ad8b1ef | 189 | |
21491412 JA |
190 | /** |
191 | * blk_start_queue_async - asynchronously restart a previously stopped queue | |
192 | * @q: The &struct request_queue in question | |
193 | * | |
194 | * Description: | |
195 | * blk_start_queue_async() will clear the stop flag on the queue, and | |
196 | * ensure that the request_fn for the queue is run from an async | |
197 | * context. | |
198 | **/ | |
199 | void blk_start_queue_async(struct request_queue *q) | |
200 | { | |
201 | queue_flag_clear(QUEUE_FLAG_STOPPED, q); | |
202 | blk_run_queue_async(q); | |
203 | } | |
204 | EXPORT_SYMBOL(blk_start_queue_async); | |
205 | ||
1da177e4 LT |
206 | /** |
207 | * blk_start_queue - restart a previously stopped queue | |
165125e1 | 208 | * @q: The &struct request_queue in question |
1da177e4 LT |
209 | * |
210 | * Description: | |
211 | * blk_start_queue() will clear the stop flag on the queue, and call | |
212 | * the request_fn for the queue if it was in a stopped state when | |
213 | * entered. Also see blk_stop_queue(). Queue lock must be held. | |
214 | **/ | |
165125e1 | 215 | void blk_start_queue(struct request_queue *q) |
1da177e4 | 216 | { |
a038e253 PBG |
217 | WARN_ON(!irqs_disabled()); |
218 | ||
75ad23bc | 219 | queue_flag_clear(QUEUE_FLAG_STOPPED, q); |
24ecfbe2 | 220 | __blk_run_queue(q); |
1da177e4 | 221 | } |
1da177e4 LT |
222 | EXPORT_SYMBOL(blk_start_queue); |
223 | ||
224 | /** | |
225 | * blk_stop_queue - stop a queue | |
165125e1 | 226 | * @q: The &struct request_queue in question |
1da177e4 LT |
227 | * |
228 | * Description: | |
229 | * The Linux block layer assumes that a block driver will consume all | |
230 | * entries on the request queue when the request_fn strategy is called. | |
231 | * Often this will not happen, because of hardware limitations (queue | |
232 | * depth settings). If a device driver gets a 'queue full' response, | |
233 | * or if it simply chooses not to queue more I/O at one point, it can | |
234 | * call this function to prevent the request_fn from being called until | |
235 | * the driver has signalled it's ready to go again. This happens by calling | |
236 | * blk_start_queue() to restart queue operations. Queue lock must be held. | |
237 | **/ | |
165125e1 | 238 | void blk_stop_queue(struct request_queue *q) |
1da177e4 | 239 | { |
136b5721 | 240 | cancel_delayed_work(&q->delay_work); |
75ad23bc | 241 | queue_flag_set(QUEUE_FLAG_STOPPED, q); |
1da177e4 LT |
242 | } |
243 | EXPORT_SYMBOL(blk_stop_queue); | |
244 | ||
245 | /** | |
246 | * blk_sync_queue - cancel any pending callbacks on a queue | |
247 | * @q: the queue | |
248 | * | |
249 | * Description: | |
250 | * The block layer may perform asynchronous callback activity | |
251 | * on a queue, such as calling the unplug function after a timeout. | |
252 | * A block device may call blk_sync_queue to ensure that any | |
253 | * such activity is cancelled, thus allowing it to release resources | |
59c51591 | 254 | * that the callbacks might use. The caller must already have made sure |
1da177e4 LT |
255 | * that its ->make_request_fn will not re-add plugging prior to calling |
256 | * this function. | |
257 | * | |
da527770 | 258 | * This function does not cancel any asynchronous activity arising |
da3dae54 | 259 | * out of elevator or throttling code. That would require elevator_exit() |
5efd6113 | 260 | * and blkcg_exit_queue() to be called with queue lock initialized. |
da527770 | 261 | * |
1da177e4 LT |
262 | */ |
263 | void blk_sync_queue(struct request_queue *q) | |
264 | { | |
70ed28b9 | 265 | del_timer_sync(&q->timeout); |
f04c1fe7 ML |
266 | |
267 | if (q->mq_ops) { | |
268 | struct blk_mq_hw_ctx *hctx; | |
269 | int i; | |
270 | ||
21c6e939 | 271 | queue_for_each_hw_ctx(q, hctx, i) |
9f993737 | 272 | cancel_delayed_work_sync(&hctx->run_work); |
f04c1fe7 ML |
273 | } else { |
274 | cancel_delayed_work_sync(&q->delay_work); | |
275 | } | |
1da177e4 LT |
276 | } |
277 | EXPORT_SYMBOL(blk_sync_queue); | |
278 | ||
c246e80d BVA |
279 | /** |
280 | * __blk_run_queue_uncond - run a queue whether or not it has been stopped | |
281 | * @q: The queue to run | |
282 | * | |
283 | * Description: | |
284 | * Invoke request handling on a queue if there are any pending requests. | |
285 | * May be used to restart request handling after a request has completed. | |
286 | * This variant runs the queue whether or not the queue has been | |
287 | * stopped. Must be called with the queue lock held and interrupts | |
288 | * disabled. See also @blk_run_queue. | |
289 | */ | |
290 | inline void __blk_run_queue_uncond(struct request_queue *q) | |
291 | { | |
292 | if (unlikely(blk_queue_dead(q))) | |
293 | return; | |
294 | ||
24faf6f6 BVA |
295 | /* |
296 | * Some request_fn implementations, e.g. scsi_request_fn(), unlock | |
297 | * the queue lock internally. As a result multiple threads may be | |
298 | * running such a request function concurrently. Keep track of the | |
299 | * number of active request_fn invocations such that blk_drain_queue() | |
300 | * can wait until all these request_fn calls have finished. | |
301 | */ | |
302 | q->request_fn_active++; | |
c246e80d | 303 | q->request_fn(q); |
24faf6f6 | 304 | q->request_fn_active--; |
c246e80d | 305 | } |
a7928c15 | 306 | EXPORT_SYMBOL_GPL(__blk_run_queue_uncond); |
c246e80d | 307 | |
1da177e4 | 308 | /** |
80a4b58e | 309 | * __blk_run_queue - run a single device queue |
1da177e4 | 310 | * @q: The queue to run |
80a4b58e JA |
311 | * |
312 | * Description: | |
313 | * See @blk_run_queue. This variant must be called with the queue lock | |
24ecfbe2 | 314 | * held and interrupts disabled. |
1da177e4 | 315 | */ |
24ecfbe2 | 316 | void __blk_run_queue(struct request_queue *q) |
1da177e4 | 317 | { |
a538cd03 TH |
318 | if (unlikely(blk_queue_stopped(q))) |
319 | return; | |
320 | ||
c246e80d | 321 | __blk_run_queue_uncond(q); |
75ad23bc NP |
322 | } |
323 | EXPORT_SYMBOL(__blk_run_queue); | |
dac07ec1 | 324 | |
24ecfbe2 CH |
325 | /** |
326 | * blk_run_queue_async - run a single device queue in workqueue context | |
327 | * @q: The queue to run | |
328 | * | |
329 | * Description: | |
330 | * Tells kblockd to perform the equivalent of @blk_run_queue on behalf | |
70460571 | 331 | * of us. The caller must hold the queue lock. |
24ecfbe2 CH |
332 | */ |
333 | void blk_run_queue_async(struct request_queue *q) | |
334 | { | |
70460571 | 335 | if (likely(!blk_queue_stopped(q) && !blk_queue_dead(q))) |
e7c2f967 | 336 | mod_delayed_work(kblockd_workqueue, &q->delay_work, 0); |
24ecfbe2 | 337 | } |
c21e6beb | 338 | EXPORT_SYMBOL(blk_run_queue_async); |
24ecfbe2 | 339 | |
75ad23bc NP |
340 | /** |
341 | * blk_run_queue - run a single device queue | |
342 | * @q: The queue to run | |
80a4b58e JA |
343 | * |
344 | * Description: | |
345 | * Invoke request handling on this queue, if it has pending work to do. | |
a7f55792 | 346 | * May be used to restart queueing when a request has completed. |
75ad23bc NP |
347 | */ |
348 | void blk_run_queue(struct request_queue *q) | |
349 | { | |
350 | unsigned long flags; | |
351 | ||
352 | spin_lock_irqsave(q->queue_lock, flags); | |
24ecfbe2 | 353 | __blk_run_queue(q); |
1da177e4 LT |
354 | spin_unlock_irqrestore(q->queue_lock, flags); |
355 | } | |
356 | EXPORT_SYMBOL(blk_run_queue); | |
357 | ||
165125e1 | 358 | void blk_put_queue(struct request_queue *q) |
483f4afc AV |
359 | { |
360 | kobject_put(&q->kobj); | |
361 | } | |
d86e0e83 | 362 | EXPORT_SYMBOL(blk_put_queue); |
483f4afc | 363 | |
e3c78ca5 | 364 | /** |
807592a4 | 365 | * __blk_drain_queue - drain requests from request_queue |
e3c78ca5 | 366 | * @q: queue to drain |
c9a929dd | 367 | * @drain_all: whether to drain all requests or only the ones w/ ELVPRIV |
e3c78ca5 | 368 | * |
c9a929dd TH |
369 | * Drain requests from @q. If @drain_all is set, all requests are drained. |
370 | * If not, only ELVPRIV requests are drained. The caller is responsible | |
371 | * for ensuring that no new requests which need to be drained are queued. | |
e3c78ca5 | 372 | */ |
807592a4 BVA |
373 | static void __blk_drain_queue(struct request_queue *q, bool drain_all) |
374 | __releases(q->queue_lock) | |
375 | __acquires(q->queue_lock) | |
e3c78ca5 | 376 | { |
458f27a9 AH |
377 | int i; |
378 | ||
807592a4 BVA |
379 | lockdep_assert_held(q->queue_lock); |
380 | ||
e3c78ca5 | 381 | while (true) { |
481a7d64 | 382 | bool drain = false; |
e3c78ca5 | 383 | |
b855b04a TH |
384 | /* |
385 | * The caller might be trying to drain @q before its | |
386 | * elevator is initialized. | |
387 | */ | |
388 | if (q->elevator) | |
389 | elv_drain_elevator(q); | |
390 | ||
5efd6113 | 391 | blkcg_drain_queue(q); |
e3c78ca5 | 392 | |
4eabc941 TH |
393 | /* |
394 | * This function might be called on a queue which failed | |
b855b04a TH |
395 | * driver init after queue creation or is not yet fully |
396 | * active yet. Some drivers (e.g. fd and loop) get unhappy | |
397 | * in such cases. Kick queue iff dispatch queue has | |
398 | * something on it and @q has request_fn set. | |
4eabc941 | 399 | */ |
b855b04a | 400 | if (!list_empty(&q->queue_head) && q->request_fn) |
4eabc941 | 401 | __blk_run_queue(q); |
c9a929dd | 402 | |
8a5ecdd4 | 403 | drain |= q->nr_rqs_elvpriv; |
24faf6f6 | 404 | drain |= q->request_fn_active; |
481a7d64 TH |
405 | |
406 | /* | |
407 | * Unfortunately, requests are queued at and tracked from | |
408 | * multiple places and there's no single counter which can | |
409 | * be drained. Check all the queues and counters. | |
410 | */ | |
411 | if (drain_all) { | |
e97c293c | 412 | struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL); |
481a7d64 TH |
413 | drain |= !list_empty(&q->queue_head); |
414 | for (i = 0; i < 2; i++) { | |
8a5ecdd4 | 415 | drain |= q->nr_rqs[i]; |
481a7d64 | 416 | drain |= q->in_flight[i]; |
7c94e1c1 ML |
417 | if (fq) |
418 | drain |= !list_empty(&fq->flush_queue[i]); | |
481a7d64 TH |
419 | } |
420 | } | |
e3c78ca5 | 421 | |
481a7d64 | 422 | if (!drain) |
e3c78ca5 | 423 | break; |
807592a4 BVA |
424 | |
425 | spin_unlock_irq(q->queue_lock); | |
426 | ||
e3c78ca5 | 427 | msleep(10); |
807592a4 BVA |
428 | |
429 | spin_lock_irq(q->queue_lock); | |
e3c78ca5 | 430 | } |
458f27a9 AH |
431 | |
432 | /* | |
433 | * With queue marked dead, any woken up waiter will fail the | |
434 | * allocation path, so the wakeup chaining is lost and we're | |
435 | * left with hung waiters. We need to wake up those waiters. | |
436 | */ | |
437 | if (q->request_fn) { | |
a051661c TH |
438 | struct request_list *rl; |
439 | ||
a051661c TH |
440 | blk_queue_for_each_rl(rl, q) |
441 | for (i = 0; i < ARRAY_SIZE(rl->wait); i++) | |
442 | wake_up_all(&rl->wait[i]); | |
458f27a9 | 443 | } |
e3c78ca5 TH |
444 | } |
445 | ||
d732580b TH |
446 | /** |
447 | * blk_queue_bypass_start - enter queue bypass mode | |
448 | * @q: queue of interest | |
449 | * | |
450 | * In bypass mode, only the dispatch FIFO queue of @q is used. This | |
451 | * function makes @q enter bypass mode and drains all requests which were | |
6ecf23af | 452 | * throttled or issued before. On return, it's guaranteed that no request |
80fd9979 TH |
453 | * is being throttled or has ELVPRIV set and blk_queue_bypass() %true |
454 | * inside queue or RCU read lock. | |
d732580b TH |
455 | */ |
456 | void blk_queue_bypass_start(struct request_queue *q) | |
457 | { | |
458 | spin_lock_irq(q->queue_lock); | |
776687bc | 459 | q->bypass_depth++; |
d732580b TH |
460 | queue_flag_set(QUEUE_FLAG_BYPASS, q); |
461 | spin_unlock_irq(q->queue_lock); | |
462 | ||
776687bc TH |
463 | /* |
464 | * Queues start drained. Skip actual draining till init is | |
465 | * complete. This avoids lenghty delays during queue init which | |
466 | * can happen many times during boot. | |
467 | */ | |
468 | if (blk_queue_init_done(q)) { | |
807592a4 BVA |
469 | spin_lock_irq(q->queue_lock); |
470 | __blk_drain_queue(q, false); | |
471 | spin_unlock_irq(q->queue_lock); | |
472 | ||
b82d4b19 TH |
473 | /* ensure blk_queue_bypass() is %true inside RCU read lock */ |
474 | synchronize_rcu(); | |
475 | } | |
d732580b TH |
476 | } |
477 | EXPORT_SYMBOL_GPL(blk_queue_bypass_start); | |
478 | ||
479 | /** | |
480 | * blk_queue_bypass_end - leave queue bypass mode | |
481 | * @q: queue of interest | |
482 | * | |
483 | * Leave bypass mode and restore the normal queueing behavior. | |
484 | */ | |
485 | void blk_queue_bypass_end(struct request_queue *q) | |
486 | { | |
487 | spin_lock_irq(q->queue_lock); | |
488 | if (!--q->bypass_depth) | |
489 | queue_flag_clear(QUEUE_FLAG_BYPASS, q); | |
490 | WARN_ON_ONCE(q->bypass_depth < 0); | |
491 | spin_unlock_irq(q->queue_lock); | |
492 | } | |
493 | EXPORT_SYMBOL_GPL(blk_queue_bypass_end); | |
494 | ||
aed3ea94 JA |
495 | void blk_set_queue_dying(struct request_queue *q) |
496 | { | |
1b856086 BVA |
497 | spin_lock_irq(q->queue_lock); |
498 | queue_flag_set(QUEUE_FLAG_DYING, q); | |
499 | spin_unlock_irq(q->queue_lock); | |
aed3ea94 | 500 | |
d3cfb2a0 ML |
501 | /* |
502 | * When queue DYING flag is set, we need to block new req | |
503 | * entering queue, so we call blk_freeze_queue_start() to | |
504 | * prevent I/O from crossing blk_queue_enter(). | |
505 | */ | |
506 | blk_freeze_queue_start(q); | |
507 | ||
aed3ea94 JA |
508 | if (q->mq_ops) |
509 | blk_mq_wake_waiters(q); | |
510 | else { | |
511 | struct request_list *rl; | |
512 | ||
bbfc3c5d | 513 | spin_lock_irq(q->queue_lock); |
aed3ea94 JA |
514 | blk_queue_for_each_rl(rl, q) { |
515 | if (rl->rq_pool) { | |
516 | wake_up(&rl->wait[BLK_RW_SYNC]); | |
517 | wake_up(&rl->wait[BLK_RW_ASYNC]); | |
518 | } | |
519 | } | |
bbfc3c5d | 520 | spin_unlock_irq(q->queue_lock); |
aed3ea94 JA |
521 | } |
522 | } | |
523 | EXPORT_SYMBOL_GPL(blk_set_queue_dying); | |
524 | ||
c9a929dd TH |
525 | /** |
526 | * blk_cleanup_queue - shutdown a request queue | |
527 | * @q: request queue to shutdown | |
528 | * | |
c246e80d BVA |
529 | * Mark @q DYING, drain all pending requests, mark @q DEAD, destroy and |
530 | * put it. All future requests will be failed immediately with -ENODEV. | |
c94a96ac | 531 | */ |
6728cb0e | 532 | void blk_cleanup_queue(struct request_queue *q) |
483f4afc | 533 | { |
c9a929dd | 534 | spinlock_t *lock = q->queue_lock; |
e3335de9 | 535 | |
3f3299d5 | 536 | /* mark @q DYING, no new request or merges will be allowed afterwards */ |
483f4afc | 537 | mutex_lock(&q->sysfs_lock); |
aed3ea94 | 538 | blk_set_queue_dying(q); |
c9a929dd | 539 | spin_lock_irq(lock); |
6ecf23af | 540 | |
80fd9979 | 541 | /* |
3f3299d5 | 542 | * A dying queue is permanently in bypass mode till released. Note |
80fd9979 TH |
543 | * that, unlike blk_queue_bypass_start(), we aren't performing |
544 | * synchronize_rcu() after entering bypass mode to avoid the delay | |
545 | * as some drivers create and destroy a lot of queues while | |
546 | * probing. This is still safe because blk_release_queue() will be | |
547 | * called only after the queue refcnt drops to zero and nothing, | |
548 | * RCU or not, would be traversing the queue by then. | |
549 | */ | |
6ecf23af TH |
550 | q->bypass_depth++; |
551 | queue_flag_set(QUEUE_FLAG_BYPASS, q); | |
552 | ||
c9a929dd TH |
553 | queue_flag_set(QUEUE_FLAG_NOMERGES, q); |
554 | queue_flag_set(QUEUE_FLAG_NOXMERGES, q); | |
3f3299d5 | 555 | queue_flag_set(QUEUE_FLAG_DYING, q); |
c9a929dd TH |
556 | spin_unlock_irq(lock); |
557 | mutex_unlock(&q->sysfs_lock); | |
558 | ||
c246e80d BVA |
559 | /* |
560 | * Drain all requests queued before DYING marking. Set DEAD flag to | |
561 | * prevent that q->request_fn() gets invoked after draining finished. | |
562 | */ | |
3ef28e83 | 563 | blk_freeze_queue(q); |
9c1051aa OS |
564 | spin_lock_irq(lock); |
565 | if (!q->mq_ops) | |
43a5e4e2 | 566 | __blk_drain_queue(q, true); |
c246e80d | 567 | queue_flag_set(QUEUE_FLAG_DEAD, q); |
807592a4 | 568 | spin_unlock_irq(lock); |
c9a929dd | 569 | |
5a48fc14 DW |
570 | /* for synchronous bio-based driver finish in-flight integrity i/o */ |
571 | blk_flush_integrity(); | |
572 | ||
c9a929dd | 573 | /* @q won't process any more request, flush async actions */ |
dc3b17cc | 574 | del_timer_sync(&q->backing_dev_info->laptop_mode_wb_timer); |
c9a929dd TH |
575 | blk_sync_queue(q); |
576 | ||
45a9c9d9 BVA |
577 | if (q->mq_ops) |
578 | blk_mq_free_queue(q); | |
3ef28e83 | 579 | percpu_ref_exit(&q->q_usage_counter); |
45a9c9d9 | 580 | |
5e5cfac0 AH |
581 | spin_lock_irq(lock); |
582 | if (q->queue_lock != &q->__queue_lock) | |
583 | q->queue_lock = &q->__queue_lock; | |
584 | spin_unlock_irq(lock); | |
585 | ||
c9a929dd | 586 | /* @q is and will stay empty, shutdown and put */ |
483f4afc AV |
587 | blk_put_queue(q); |
588 | } | |
1da177e4 LT |
589 | EXPORT_SYMBOL(blk_cleanup_queue); |
590 | ||
271508db | 591 | /* Allocate memory local to the request queue */ |
6d247d7f | 592 | static void *alloc_request_simple(gfp_t gfp_mask, void *data) |
271508db | 593 | { |
6d247d7f CH |
594 | struct request_queue *q = data; |
595 | ||
596 | return kmem_cache_alloc_node(request_cachep, gfp_mask, q->node); | |
271508db DR |
597 | } |
598 | ||
6d247d7f | 599 | static void free_request_simple(void *element, void *data) |
271508db DR |
600 | { |
601 | kmem_cache_free(request_cachep, element); | |
602 | } | |
603 | ||
6d247d7f CH |
604 | static void *alloc_request_size(gfp_t gfp_mask, void *data) |
605 | { | |
606 | struct request_queue *q = data; | |
607 | struct request *rq; | |
608 | ||
609 | rq = kmalloc_node(sizeof(struct request) + q->cmd_size, gfp_mask, | |
610 | q->node); | |
611 | if (rq && q->init_rq_fn && q->init_rq_fn(q, rq, gfp_mask) < 0) { | |
612 | kfree(rq); | |
613 | rq = NULL; | |
614 | } | |
615 | return rq; | |
616 | } | |
617 | ||
618 | static void free_request_size(void *element, void *data) | |
619 | { | |
620 | struct request_queue *q = data; | |
621 | ||
622 | if (q->exit_rq_fn) | |
623 | q->exit_rq_fn(q, element); | |
624 | kfree(element); | |
625 | } | |
626 | ||
5b788ce3 TH |
627 | int blk_init_rl(struct request_list *rl, struct request_queue *q, |
628 | gfp_t gfp_mask) | |
1da177e4 | 629 | { |
1abec4fd MS |
630 | if (unlikely(rl->rq_pool)) |
631 | return 0; | |
632 | ||
5b788ce3 | 633 | rl->q = q; |
1faa16d2 JA |
634 | rl->count[BLK_RW_SYNC] = rl->count[BLK_RW_ASYNC] = 0; |
635 | rl->starved[BLK_RW_SYNC] = rl->starved[BLK_RW_ASYNC] = 0; | |
1faa16d2 JA |
636 | init_waitqueue_head(&rl->wait[BLK_RW_SYNC]); |
637 | init_waitqueue_head(&rl->wait[BLK_RW_ASYNC]); | |
1da177e4 | 638 | |
6d247d7f CH |
639 | if (q->cmd_size) { |
640 | rl->rq_pool = mempool_create_node(BLKDEV_MIN_RQ, | |
641 | alloc_request_size, free_request_size, | |
642 | q, gfp_mask, q->node); | |
643 | } else { | |
644 | rl->rq_pool = mempool_create_node(BLKDEV_MIN_RQ, | |
645 | alloc_request_simple, free_request_simple, | |
646 | q, gfp_mask, q->node); | |
647 | } | |
1da177e4 LT |
648 | if (!rl->rq_pool) |
649 | return -ENOMEM; | |
650 | ||
651 | return 0; | |
652 | } | |
653 | ||
5b788ce3 TH |
654 | void blk_exit_rl(struct request_list *rl) |
655 | { | |
656 | if (rl->rq_pool) | |
657 | mempool_destroy(rl->rq_pool); | |
658 | } | |
659 | ||
165125e1 | 660 | struct request_queue *blk_alloc_queue(gfp_t gfp_mask) |
1da177e4 | 661 | { |
c304a51b | 662 | return blk_alloc_queue_node(gfp_mask, NUMA_NO_NODE); |
1946089a CL |
663 | } |
664 | EXPORT_SYMBOL(blk_alloc_queue); | |
1da177e4 | 665 | |
6f3b0e8b | 666 | int blk_queue_enter(struct request_queue *q, bool nowait) |
3ef28e83 DW |
667 | { |
668 | while (true) { | |
669 | int ret; | |
670 | ||
671 | if (percpu_ref_tryget_live(&q->q_usage_counter)) | |
672 | return 0; | |
673 | ||
6f3b0e8b | 674 | if (nowait) |
3ef28e83 DW |
675 | return -EBUSY; |
676 | ||
5ed61d3f | 677 | /* |
1671d522 | 678 | * read pair of barrier in blk_freeze_queue_start(), |
5ed61d3f | 679 | * we need to order reading __PERCPU_REF_DEAD flag of |
d3cfb2a0 ML |
680 | * .q_usage_counter and reading .mq_freeze_depth or |
681 | * queue dying flag, otherwise the following wait may | |
682 | * never return if the two reads are reordered. | |
5ed61d3f ML |
683 | */ |
684 | smp_rmb(); | |
685 | ||
3ef28e83 DW |
686 | ret = wait_event_interruptible(q->mq_freeze_wq, |
687 | !atomic_read(&q->mq_freeze_depth) || | |
688 | blk_queue_dying(q)); | |
689 | if (blk_queue_dying(q)) | |
690 | return -ENODEV; | |
691 | if (ret) | |
692 | return ret; | |
693 | } | |
694 | } | |
695 | ||
696 | void blk_queue_exit(struct request_queue *q) | |
697 | { | |
698 | percpu_ref_put(&q->q_usage_counter); | |
699 | } | |
700 | ||
701 | static void blk_queue_usage_counter_release(struct percpu_ref *ref) | |
702 | { | |
703 | struct request_queue *q = | |
704 | container_of(ref, struct request_queue, q_usage_counter); | |
705 | ||
706 | wake_up_all(&q->mq_freeze_wq); | |
707 | } | |
708 | ||
287922eb CH |
709 | static void blk_rq_timed_out_timer(unsigned long data) |
710 | { | |
711 | struct request_queue *q = (struct request_queue *)data; | |
712 | ||
713 | kblockd_schedule_work(&q->timeout_work); | |
714 | } | |
715 | ||
165125e1 | 716 | struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id) |
1946089a | 717 | { |
165125e1 | 718 | struct request_queue *q; |
1946089a | 719 | |
8324aa91 | 720 | q = kmem_cache_alloc_node(blk_requestq_cachep, |
94f6030c | 721 | gfp_mask | __GFP_ZERO, node_id); |
1da177e4 LT |
722 | if (!q) |
723 | return NULL; | |
724 | ||
00380a40 | 725 | q->id = ida_simple_get(&blk_queue_ida, 0, 0, gfp_mask); |
a73f730d | 726 | if (q->id < 0) |
3d2936f4 | 727 | goto fail_q; |
a73f730d | 728 | |
54efd50b KO |
729 | q->bio_split = bioset_create(BIO_POOL_SIZE, 0); |
730 | if (!q->bio_split) | |
731 | goto fail_id; | |
732 | ||
d03f6cdc JK |
733 | q->backing_dev_info = bdi_alloc_node(gfp_mask, node_id); |
734 | if (!q->backing_dev_info) | |
735 | goto fail_split; | |
736 | ||
a83b576c JA |
737 | q->stats = blk_alloc_queue_stats(); |
738 | if (!q->stats) | |
739 | goto fail_stats; | |
740 | ||
dc3b17cc | 741 | q->backing_dev_info->ra_pages = |
09cbfeaf | 742 | (VM_MAX_READAHEAD * 1024) / PAGE_SIZE; |
dc3b17cc JK |
743 | q->backing_dev_info->capabilities = BDI_CAP_CGROUP_WRITEBACK; |
744 | q->backing_dev_info->name = "block"; | |
5151412d | 745 | q->node = node_id; |
0989a025 | 746 | |
dc3b17cc | 747 | setup_timer(&q->backing_dev_info->laptop_mode_wb_timer, |
31373d09 | 748 | laptop_mode_timer_fn, (unsigned long) q); |
242f9dcb | 749 | setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q); |
b855b04a | 750 | INIT_LIST_HEAD(&q->queue_head); |
242f9dcb | 751 | INIT_LIST_HEAD(&q->timeout_list); |
a612fddf | 752 | INIT_LIST_HEAD(&q->icq_list); |
4eef3049 | 753 | #ifdef CONFIG_BLK_CGROUP |
e8989fae | 754 | INIT_LIST_HEAD(&q->blkg_list); |
4eef3049 | 755 | #endif |
3cca6dc1 | 756 | INIT_DELAYED_WORK(&q->delay_work, blk_delay_work); |
483f4afc | 757 | |
8324aa91 | 758 | kobject_init(&q->kobj, &blk_queue_ktype); |
1da177e4 | 759 | |
483f4afc | 760 | mutex_init(&q->sysfs_lock); |
e7e72bf6 | 761 | spin_lock_init(&q->__queue_lock); |
483f4afc | 762 | |
c94a96ac VG |
763 | /* |
764 | * By default initialize queue_lock to internal lock and driver can | |
765 | * override it later if need be. | |
766 | */ | |
767 | q->queue_lock = &q->__queue_lock; | |
768 | ||
b82d4b19 TH |
769 | /* |
770 | * A queue starts its life with bypass turned on to avoid | |
771 | * unnecessary bypass on/off overhead and nasty surprises during | |
749fefe6 TH |
772 | * init. The initial bypass will be finished when the queue is |
773 | * registered by blk_register_queue(). | |
b82d4b19 TH |
774 | */ |
775 | q->bypass_depth = 1; | |
776 | __set_bit(QUEUE_FLAG_BYPASS, &q->queue_flags); | |
777 | ||
320ae51f JA |
778 | init_waitqueue_head(&q->mq_freeze_wq); |
779 | ||
3ef28e83 DW |
780 | /* |
781 | * Init percpu_ref in atomic mode so that it's faster to shutdown. | |
782 | * See blk_register_queue() for details. | |
783 | */ | |
784 | if (percpu_ref_init(&q->q_usage_counter, | |
785 | blk_queue_usage_counter_release, | |
786 | PERCPU_REF_INIT_ATOMIC, GFP_KERNEL)) | |
fff4996b | 787 | goto fail_bdi; |
f51b802c | 788 | |
3ef28e83 DW |
789 | if (blkcg_init_queue(q)) |
790 | goto fail_ref; | |
791 | ||
1da177e4 | 792 | return q; |
a73f730d | 793 | |
3ef28e83 DW |
794 | fail_ref: |
795 | percpu_ref_exit(&q->q_usage_counter); | |
fff4996b | 796 | fail_bdi: |
a83b576c JA |
797 | blk_free_queue_stats(q->stats); |
798 | fail_stats: | |
d03f6cdc | 799 | bdi_put(q->backing_dev_info); |
54efd50b KO |
800 | fail_split: |
801 | bioset_free(q->bio_split); | |
a73f730d TH |
802 | fail_id: |
803 | ida_simple_remove(&blk_queue_ida, q->id); | |
804 | fail_q: | |
805 | kmem_cache_free(blk_requestq_cachep, q); | |
806 | return NULL; | |
1da177e4 | 807 | } |
1946089a | 808 | EXPORT_SYMBOL(blk_alloc_queue_node); |
1da177e4 LT |
809 | |
810 | /** | |
811 | * blk_init_queue - prepare a request queue for use with a block device | |
812 | * @rfn: The function to be called to process requests that have been | |
813 | * placed on the queue. | |
814 | * @lock: Request queue spin lock | |
815 | * | |
816 | * Description: | |
817 | * If a block device wishes to use the standard request handling procedures, | |
818 | * which sorts requests and coalesces adjacent requests, then it must | |
819 | * call blk_init_queue(). The function @rfn will be called when there | |
820 | * are requests on the queue that need to be processed. If the device | |
821 | * supports plugging, then @rfn may not be called immediately when requests | |
822 | * are available on the queue, but may be called at some time later instead. | |
823 | * Plugged queues are generally unplugged when a buffer belonging to one | |
824 | * of the requests on the queue is needed, or due to memory pressure. | |
825 | * | |
826 | * @rfn is not required, or even expected, to remove all requests off the | |
827 | * queue, but only as many as it can handle at a time. If it does leave | |
828 | * requests on the queue, it is responsible for arranging that the requests | |
829 | * get dealt with eventually. | |
830 | * | |
831 | * The queue spin lock must be held while manipulating the requests on the | |
a038e253 PBG |
832 | * request queue; this lock will be taken also from interrupt context, so irq |
833 | * disabling is needed for it. | |
1da177e4 | 834 | * |
710027a4 | 835 | * Function returns a pointer to the initialized request queue, or %NULL if |
1da177e4 LT |
836 | * it didn't succeed. |
837 | * | |
838 | * Note: | |
839 | * blk_init_queue() must be paired with a blk_cleanup_queue() call | |
840 | * when the block device is deactivated (such as at module unload). | |
841 | **/ | |
1946089a | 842 | |
165125e1 | 843 | struct request_queue *blk_init_queue(request_fn_proc *rfn, spinlock_t *lock) |
1da177e4 | 844 | { |
c304a51b | 845 | return blk_init_queue_node(rfn, lock, NUMA_NO_NODE); |
1946089a CL |
846 | } |
847 | EXPORT_SYMBOL(blk_init_queue); | |
848 | ||
165125e1 | 849 | struct request_queue * |
1946089a CL |
850 | blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id) |
851 | { | |
5ea708d1 | 852 | struct request_queue *q; |
1da177e4 | 853 | |
5ea708d1 CH |
854 | q = blk_alloc_queue_node(GFP_KERNEL, node_id); |
855 | if (!q) | |
c86d1b8a MS |
856 | return NULL; |
857 | ||
5ea708d1 CH |
858 | q->request_fn = rfn; |
859 | if (lock) | |
860 | q->queue_lock = lock; | |
861 | if (blk_init_allocated_queue(q) < 0) { | |
862 | blk_cleanup_queue(q); | |
863 | return NULL; | |
864 | } | |
18741986 | 865 | |
7982e90c | 866 | return q; |
01effb0d MS |
867 | } |
868 | EXPORT_SYMBOL(blk_init_queue_node); | |
869 | ||
dece1635 | 870 | static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio); |
336b7e1f | 871 | |
1da177e4 | 872 | |
5ea708d1 CH |
873 | int blk_init_allocated_queue(struct request_queue *q) |
874 | { | |
6d247d7f | 875 | q->fq = blk_alloc_flush_queue(q, NUMA_NO_NODE, q->cmd_size); |
ba483388 | 876 | if (!q->fq) |
5ea708d1 | 877 | return -ENOMEM; |
7982e90c | 878 | |
6d247d7f CH |
879 | if (q->init_rq_fn && q->init_rq_fn(q, q->fq->flush_rq, GFP_KERNEL)) |
880 | goto out_free_flush_queue; | |
7982e90c | 881 | |
a051661c | 882 | if (blk_init_rl(&q->root_rl, q, GFP_KERNEL)) |
6d247d7f | 883 | goto out_exit_flush_rq; |
1da177e4 | 884 | |
287922eb | 885 | INIT_WORK(&q->timeout_work, blk_timeout_work); |
60ea8226 | 886 | q->queue_flags |= QUEUE_FLAG_DEFAULT; |
c94a96ac | 887 | |
f3b144aa JA |
888 | /* |
889 | * This also sets hw/phys segments, boundary and size | |
890 | */ | |
c20e8de2 | 891 | blk_queue_make_request(q, blk_queue_bio); |
1da177e4 | 892 | |
44ec9542 AS |
893 | q->sg_reserved_size = INT_MAX; |
894 | ||
eb1c160b TS |
895 | /* Protect q->elevator from elevator_change */ |
896 | mutex_lock(&q->sysfs_lock); | |
897 | ||
b82d4b19 | 898 | /* init elevator */ |
eb1c160b TS |
899 | if (elevator_init(q, NULL)) { |
900 | mutex_unlock(&q->sysfs_lock); | |
6d247d7f | 901 | goto out_exit_flush_rq; |
eb1c160b TS |
902 | } |
903 | ||
904 | mutex_unlock(&q->sysfs_lock); | |
5ea708d1 | 905 | return 0; |
eb1c160b | 906 | |
6d247d7f CH |
907 | out_exit_flush_rq: |
908 | if (q->exit_rq_fn) | |
909 | q->exit_rq_fn(q, q->fq->flush_rq); | |
910 | out_free_flush_queue: | |
ba483388 | 911 | blk_free_flush_queue(q->fq); |
5ea708d1 | 912 | return -ENOMEM; |
1da177e4 | 913 | } |
5151412d | 914 | EXPORT_SYMBOL(blk_init_allocated_queue); |
1da177e4 | 915 | |
09ac46c4 | 916 | bool blk_get_queue(struct request_queue *q) |
1da177e4 | 917 | { |
3f3299d5 | 918 | if (likely(!blk_queue_dying(q))) { |
09ac46c4 TH |
919 | __blk_get_queue(q); |
920 | return true; | |
1da177e4 LT |
921 | } |
922 | ||
09ac46c4 | 923 | return false; |
1da177e4 | 924 | } |
d86e0e83 | 925 | EXPORT_SYMBOL(blk_get_queue); |
1da177e4 | 926 | |
5b788ce3 | 927 | static inline void blk_free_request(struct request_list *rl, struct request *rq) |
1da177e4 | 928 | { |
e8064021 | 929 | if (rq->rq_flags & RQF_ELVPRIV) { |
5b788ce3 | 930 | elv_put_request(rl->q, rq); |
f1f8cc94 | 931 | if (rq->elv.icq) |
11a3122f | 932 | put_io_context(rq->elv.icq->ioc); |
f1f8cc94 TH |
933 | } |
934 | ||
5b788ce3 | 935 | mempool_free(rq, rl->rq_pool); |
1da177e4 LT |
936 | } |
937 | ||
1da177e4 LT |
938 | /* |
939 | * ioc_batching returns true if the ioc is a valid batching request and | |
940 | * should be given priority access to a request. | |
941 | */ | |
165125e1 | 942 | static inline int ioc_batching(struct request_queue *q, struct io_context *ioc) |
1da177e4 LT |
943 | { |
944 | if (!ioc) | |
945 | return 0; | |
946 | ||
947 | /* | |
948 | * Make sure the process is able to allocate at least 1 request | |
949 | * even if the batch times out, otherwise we could theoretically | |
950 | * lose wakeups. | |
951 | */ | |
952 | return ioc->nr_batch_requests == q->nr_batching || | |
953 | (ioc->nr_batch_requests > 0 | |
954 | && time_before(jiffies, ioc->last_waited + BLK_BATCH_TIME)); | |
955 | } | |
956 | ||
957 | /* | |
958 | * ioc_set_batching sets ioc to be a new "batcher" if it is not one. This | |
959 | * will cause the process to be a "batcher" on all queues in the system. This | |
960 | * is the behaviour we want though - once it gets a wakeup it should be given | |
961 | * a nice run. | |
962 | */ | |
165125e1 | 963 | static void ioc_set_batching(struct request_queue *q, struct io_context *ioc) |
1da177e4 LT |
964 | { |
965 | if (!ioc || ioc_batching(q, ioc)) | |
966 | return; | |
967 | ||
968 | ioc->nr_batch_requests = q->nr_batching; | |
969 | ioc->last_waited = jiffies; | |
970 | } | |
971 | ||
5b788ce3 | 972 | static void __freed_request(struct request_list *rl, int sync) |
1da177e4 | 973 | { |
5b788ce3 | 974 | struct request_queue *q = rl->q; |
1da177e4 | 975 | |
d40f75a0 TH |
976 | if (rl->count[sync] < queue_congestion_off_threshold(q)) |
977 | blk_clear_congested(rl, sync); | |
1da177e4 | 978 | |
1faa16d2 JA |
979 | if (rl->count[sync] + 1 <= q->nr_requests) { |
980 | if (waitqueue_active(&rl->wait[sync])) | |
981 | wake_up(&rl->wait[sync]); | |
1da177e4 | 982 | |
5b788ce3 | 983 | blk_clear_rl_full(rl, sync); |
1da177e4 LT |
984 | } |
985 | } | |
986 | ||
987 | /* | |
988 | * A request has just been released. Account for it, update the full and | |
989 | * congestion status, wake up any waiters. Called under q->queue_lock. | |
990 | */ | |
e8064021 CH |
991 | static void freed_request(struct request_list *rl, bool sync, |
992 | req_flags_t rq_flags) | |
1da177e4 | 993 | { |
5b788ce3 | 994 | struct request_queue *q = rl->q; |
1da177e4 | 995 | |
8a5ecdd4 | 996 | q->nr_rqs[sync]--; |
1faa16d2 | 997 | rl->count[sync]--; |
e8064021 | 998 | if (rq_flags & RQF_ELVPRIV) |
8a5ecdd4 | 999 | q->nr_rqs_elvpriv--; |
1da177e4 | 1000 | |
5b788ce3 | 1001 | __freed_request(rl, sync); |
1da177e4 | 1002 | |
1faa16d2 | 1003 | if (unlikely(rl->starved[sync ^ 1])) |
5b788ce3 | 1004 | __freed_request(rl, sync ^ 1); |
1da177e4 LT |
1005 | } |
1006 | ||
e3a2b3f9 JA |
1007 | int blk_update_nr_requests(struct request_queue *q, unsigned int nr) |
1008 | { | |
1009 | struct request_list *rl; | |
d40f75a0 | 1010 | int on_thresh, off_thresh; |
e3a2b3f9 JA |
1011 | |
1012 | spin_lock_irq(q->queue_lock); | |
1013 | q->nr_requests = nr; | |
1014 | blk_queue_congestion_threshold(q); | |
d40f75a0 TH |
1015 | on_thresh = queue_congestion_on_threshold(q); |
1016 | off_thresh = queue_congestion_off_threshold(q); | |
e3a2b3f9 | 1017 | |
d40f75a0 TH |
1018 | blk_queue_for_each_rl(rl, q) { |
1019 | if (rl->count[BLK_RW_SYNC] >= on_thresh) | |
1020 | blk_set_congested(rl, BLK_RW_SYNC); | |
1021 | else if (rl->count[BLK_RW_SYNC] < off_thresh) | |
1022 | blk_clear_congested(rl, BLK_RW_SYNC); | |
e3a2b3f9 | 1023 | |
d40f75a0 TH |
1024 | if (rl->count[BLK_RW_ASYNC] >= on_thresh) |
1025 | blk_set_congested(rl, BLK_RW_ASYNC); | |
1026 | else if (rl->count[BLK_RW_ASYNC] < off_thresh) | |
1027 | blk_clear_congested(rl, BLK_RW_ASYNC); | |
e3a2b3f9 | 1028 | |
e3a2b3f9 JA |
1029 | if (rl->count[BLK_RW_SYNC] >= q->nr_requests) { |
1030 | blk_set_rl_full(rl, BLK_RW_SYNC); | |
1031 | } else { | |
1032 | blk_clear_rl_full(rl, BLK_RW_SYNC); | |
1033 | wake_up(&rl->wait[BLK_RW_SYNC]); | |
1034 | } | |
1035 | ||
1036 | if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) { | |
1037 | blk_set_rl_full(rl, BLK_RW_ASYNC); | |
1038 | } else { | |
1039 | blk_clear_rl_full(rl, BLK_RW_ASYNC); | |
1040 | wake_up(&rl->wait[BLK_RW_ASYNC]); | |
1041 | } | |
1042 | } | |
1043 | ||
1044 | spin_unlock_irq(q->queue_lock); | |
1045 | return 0; | |
1046 | } | |
1047 | ||
da8303c6 | 1048 | /** |
a06e05e6 | 1049 | * __get_request - get a free request |
5b788ce3 | 1050 | * @rl: request list to allocate from |
ef295ecf | 1051 | * @op: operation and flags |
da8303c6 TH |
1052 | * @bio: bio to allocate request for (can be %NULL) |
1053 | * @gfp_mask: allocation mask | |
1054 | * | |
1055 | * Get a free request from @q. This function may fail under memory | |
1056 | * pressure or if @q is dead. | |
1057 | * | |
da3dae54 | 1058 | * Must be called with @q->queue_lock held and, |
a492f075 JL |
1059 | * Returns ERR_PTR on failure, with @q->queue_lock held. |
1060 | * Returns request pointer on success, with @q->queue_lock *not held*. | |
1da177e4 | 1061 | */ |
ef295ecf CH |
1062 | static struct request *__get_request(struct request_list *rl, unsigned int op, |
1063 | struct bio *bio, gfp_t gfp_mask) | |
1da177e4 | 1064 | { |
5b788ce3 | 1065 | struct request_queue *q = rl->q; |
b679281a | 1066 | struct request *rq; |
7f4b35d1 TH |
1067 | struct elevator_type *et = q->elevator->type; |
1068 | struct io_context *ioc = rq_ioc(bio); | |
f1f8cc94 | 1069 | struct io_cq *icq = NULL; |
ef295ecf | 1070 | const bool is_sync = op_is_sync(op); |
75eb6c37 | 1071 | int may_queue; |
e8064021 | 1072 | req_flags_t rq_flags = RQF_ALLOCED; |
88ee5ef1 | 1073 | |
3f3299d5 | 1074 | if (unlikely(blk_queue_dying(q))) |
a492f075 | 1075 | return ERR_PTR(-ENODEV); |
da8303c6 | 1076 | |
ef295ecf | 1077 | may_queue = elv_may_queue(q, op); |
88ee5ef1 JA |
1078 | if (may_queue == ELV_MQUEUE_NO) |
1079 | goto rq_starved; | |
1080 | ||
1faa16d2 JA |
1081 | if (rl->count[is_sync]+1 >= queue_congestion_on_threshold(q)) { |
1082 | if (rl->count[is_sync]+1 >= q->nr_requests) { | |
88ee5ef1 JA |
1083 | /* |
1084 | * The queue will fill after this allocation, so set | |
1085 | * it as full, and mark this process as "batching". | |
1086 | * This process will be allowed to complete a batch of | |
1087 | * requests, others will be blocked. | |
1088 | */ | |
5b788ce3 | 1089 | if (!blk_rl_full(rl, is_sync)) { |
88ee5ef1 | 1090 | ioc_set_batching(q, ioc); |
5b788ce3 | 1091 | blk_set_rl_full(rl, is_sync); |
88ee5ef1 JA |
1092 | } else { |
1093 | if (may_queue != ELV_MQUEUE_MUST | |
1094 | && !ioc_batching(q, ioc)) { | |
1095 | /* | |
1096 | * The queue is full and the allocating | |
1097 | * process is not a "batcher", and not | |
1098 | * exempted by the IO scheduler | |
1099 | */ | |
a492f075 | 1100 | return ERR_PTR(-ENOMEM); |
88ee5ef1 JA |
1101 | } |
1102 | } | |
1da177e4 | 1103 | } |
d40f75a0 | 1104 | blk_set_congested(rl, is_sync); |
1da177e4 LT |
1105 | } |
1106 | ||
082cf69e JA |
1107 | /* |
1108 | * Only allow batching queuers to allocate up to 50% over the defined | |
1109 | * limit of requests, otherwise we could have thousands of requests | |
1110 | * allocated with any setting of ->nr_requests | |
1111 | */ | |
1faa16d2 | 1112 | if (rl->count[is_sync] >= (3 * q->nr_requests / 2)) |
a492f075 | 1113 | return ERR_PTR(-ENOMEM); |
fd782a4a | 1114 | |
8a5ecdd4 | 1115 | q->nr_rqs[is_sync]++; |
1faa16d2 JA |
1116 | rl->count[is_sync]++; |
1117 | rl->starved[is_sync] = 0; | |
cb98fc8b | 1118 | |
f1f8cc94 TH |
1119 | /* |
1120 | * Decide whether the new request will be managed by elevator. If | |
e8064021 | 1121 | * so, mark @rq_flags and increment elvpriv. Non-zero elvpriv will |
f1f8cc94 TH |
1122 | * prevent the current elevator from being destroyed until the new |
1123 | * request is freed. This guarantees icq's won't be destroyed and | |
1124 | * makes creating new ones safe. | |
1125 | * | |
e6f7f93d CH |
1126 | * Flush requests do not use the elevator so skip initialization. |
1127 | * This allows a request to share the flush and elevator data. | |
1128 | * | |
f1f8cc94 TH |
1129 | * Also, lookup icq while holding queue_lock. If it doesn't exist, |
1130 | * it will be created after releasing queue_lock. | |
1131 | */ | |
e6f7f93d | 1132 | if (!op_is_flush(op) && !blk_queue_bypass(q)) { |
e8064021 | 1133 | rq_flags |= RQF_ELVPRIV; |
8a5ecdd4 | 1134 | q->nr_rqs_elvpriv++; |
f1f8cc94 TH |
1135 | if (et->icq_cache && ioc) |
1136 | icq = ioc_lookup_icq(ioc, q); | |
9d5a4e94 | 1137 | } |
cb98fc8b | 1138 | |
f253b86b | 1139 | if (blk_queue_io_stat(q)) |
e8064021 | 1140 | rq_flags |= RQF_IO_STAT; |
1da177e4 LT |
1141 | spin_unlock_irq(q->queue_lock); |
1142 | ||
29e2b09a | 1143 | /* allocate and init request */ |
5b788ce3 | 1144 | rq = mempool_alloc(rl->rq_pool, gfp_mask); |
29e2b09a | 1145 | if (!rq) |
b679281a | 1146 | goto fail_alloc; |
1da177e4 | 1147 | |
29e2b09a | 1148 | blk_rq_init(q, rq); |
a051661c | 1149 | blk_rq_set_rl(rq, rl); |
ef295ecf | 1150 | rq->cmd_flags = op; |
e8064021 | 1151 | rq->rq_flags = rq_flags; |
29e2b09a | 1152 | |
aaf7c680 | 1153 | /* init elvpriv */ |
e8064021 | 1154 | if (rq_flags & RQF_ELVPRIV) { |
aaf7c680 | 1155 | if (unlikely(et->icq_cache && !icq)) { |
7f4b35d1 TH |
1156 | if (ioc) |
1157 | icq = ioc_create_icq(ioc, q, gfp_mask); | |
aaf7c680 TH |
1158 | if (!icq) |
1159 | goto fail_elvpriv; | |
29e2b09a | 1160 | } |
aaf7c680 TH |
1161 | |
1162 | rq->elv.icq = icq; | |
1163 | if (unlikely(elv_set_request(q, rq, bio, gfp_mask))) | |
1164 | goto fail_elvpriv; | |
1165 | ||
1166 | /* @rq->elv.icq holds io_context until @rq is freed */ | |
29e2b09a TH |
1167 | if (icq) |
1168 | get_io_context(icq->ioc); | |
1169 | } | |
aaf7c680 | 1170 | out: |
88ee5ef1 JA |
1171 | /* |
1172 | * ioc may be NULL here, and ioc_batching will be false. That's | |
1173 | * OK, if the queue is under the request limit then requests need | |
1174 | * not count toward the nr_batch_requests limit. There will always | |
1175 | * be some limit enforced by BLK_BATCH_TIME. | |
1176 | */ | |
1da177e4 LT |
1177 | if (ioc_batching(q, ioc)) |
1178 | ioc->nr_batch_requests--; | |
6728cb0e | 1179 | |
e6a40b09 | 1180 | trace_block_getrq(q, bio, op); |
1da177e4 | 1181 | return rq; |
b679281a | 1182 | |
aaf7c680 TH |
1183 | fail_elvpriv: |
1184 | /* | |
1185 | * elvpriv init failed. ioc, icq and elvpriv aren't mempool backed | |
1186 | * and may fail indefinitely under memory pressure and thus | |
1187 | * shouldn't stall IO. Treat this request as !elvpriv. This will | |
1188 | * disturb iosched and blkcg but weird is bettern than dead. | |
1189 | */ | |
7b2b10e0 | 1190 | printk_ratelimited(KERN_WARNING "%s: dev %s: request aux data allocation failed, iosched may be disturbed\n", |
dc3b17cc | 1191 | __func__, dev_name(q->backing_dev_info->dev)); |
aaf7c680 | 1192 | |
e8064021 | 1193 | rq->rq_flags &= ~RQF_ELVPRIV; |
aaf7c680 TH |
1194 | rq->elv.icq = NULL; |
1195 | ||
1196 | spin_lock_irq(q->queue_lock); | |
8a5ecdd4 | 1197 | q->nr_rqs_elvpriv--; |
aaf7c680 TH |
1198 | spin_unlock_irq(q->queue_lock); |
1199 | goto out; | |
1200 | ||
b679281a TH |
1201 | fail_alloc: |
1202 | /* | |
1203 | * Allocation failed presumably due to memory. Undo anything we | |
1204 | * might have messed up. | |
1205 | * | |
1206 | * Allocating task should really be put onto the front of the wait | |
1207 | * queue, but this is pretty rare. | |
1208 | */ | |
1209 | spin_lock_irq(q->queue_lock); | |
e8064021 | 1210 | freed_request(rl, is_sync, rq_flags); |
b679281a TH |
1211 | |
1212 | /* | |
1213 | * in the very unlikely event that allocation failed and no | |
1214 | * requests for this direction was pending, mark us starved so that | |
1215 | * freeing of a request in the other direction will notice | |
1216 | * us. another possible fix would be to split the rq mempool into | |
1217 | * READ and WRITE | |
1218 | */ | |
1219 | rq_starved: | |
1220 | if (unlikely(rl->count[is_sync] == 0)) | |
1221 | rl->starved[is_sync] = 1; | |
a492f075 | 1222 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
1223 | } |
1224 | ||
da8303c6 | 1225 | /** |
a06e05e6 | 1226 | * get_request - get a free request |
da8303c6 | 1227 | * @q: request_queue to allocate request from |
ef295ecf | 1228 | * @op: operation and flags |
da8303c6 | 1229 | * @bio: bio to allocate request for (can be %NULL) |
a06e05e6 | 1230 | * @gfp_mask: allocation mask |
da8303c6 | 1231 | * |
d0164adc MG |
1232 | * Get a free request from @q. If %__GFP_DIRECT_RECLAIM is set in @gfp_mask, |
1233 | * this function keeps retrying under memory pressure and fails iff @q is dead. | |
d6344532 | 1234 | * |
da3dae54 | 1235 | * Must be called with @q->queue_lock held and, |
a492f075 JL |
1236 | * Returns ERR_PTR on failure, with @q->queue_lock held. |
1237 | * Returns request pointer on success, with @q->queue_lock *not held*. | |
1da177e4 | 1238 | */ |
ef295ecf CH |
1239 | static struct request *get_request(struct request_queue *q, unsigned int op, |
1240 | struct bio *bio, gfp_t gfp_mask) | |
1da177e4 | 1241 | { |
ef295ecf | 1242 | const bool is_sync = op_is_sync(op); |
a06e05e6 | 1243 | DEFINE_WAIT(wait); |
a051661c | 1244 | struct request_list *rl; |
1da177e4 | 1245 | struct request *rq; |
a051661c TH |
1246 | |
1247 | rl = blk_get_rl(q, bio); /* transferred to @rq on success */ | |
a06e05e6 | 1248 | retry: |
ef295ecf | 1249 | rq = __get_request(rl, op, bio, gfp_mask); |
a492f075 | 1250 | if (!IS_ERR(rq)) |
a06e05e6 | 1251 | return rq; |
1da177e4 | 1252 | |
d0164adc | 1253 | if (!gfpflags_allow_blocking(gfp_mask) || unlikely(blk_queue_dying(q))) { |
a051661c | 1254 | blk_put_rl(rl); |
a492f075 | 1255 | return rq; |
a051661c | 1256 | } |
1da177e4 | 1257 | |
a06e05e6 TH |
1258 | /* wait on @rl and retry */ |
1259 | prepare_to_wait_exclusive(&rl->wait[is_sync], &wait, | |
1260 | TASK_UNINTERRUPTIBLE); | |
1da177e4 | 1261 | |
e6a40b09 | 1262 | trace_block_sleeprq(q, bio, op); |
1da177e4 | 1263 | |
a06e05e6 TH |
1264 | spin_unlock_irq(q->queue_lock); |
1265 | io_schedule(); | |
d6344532 | 1266 | |
a06e05e6 TH |
1267 | /* |
1268 | * After sleeping, we become a "batching" process and will be able | |
1269 | * to allocate at least one request, and up to a big batch of them | |
1270 | * for a small period time. See ioc_batching, ioc_set_batching | |
1271 | */ | |
a06e05e6 | 1272 | ioc_set_batching(q, current->io_context); |
05caf8db | 1273 | |
a06e05e6 TH |
1274 | spin_lock_irq(q->queue_lock); |
1275 | finish_wait(&rl->wait[is_sync], &wait); | |
1da177e4 | 1276 | |
a06e05e6 | 1277 | goto retry; |
1da177e4 LT |
1278 | } |
1279 | ||
320ae51f JA |
1280 | static struct request *blk_old_get_request(struct request_queue *q, int rw, |
1281 | gfp_t gfp_mask) | |
1da177e4 LT |
1282 | { |
1283 | struct request *rq; | |
1284 | ||
7f4b35d1 TH |
1285 | /* create ioc upfront */ |
1286 | create_io_context(gfp_mask, q->node); | |
1287 | ||
d6344532 | 1288 | spin_lock_irq(q->queue_lock); |
ef295ecf | 1289 | rq = get_request(q, rw, NULL, gfp_mask); |
0c4de0f3 | 1290 | if (IS_ERR(rq)) { |
da8303c6 | 1291 | spin_unlock_irq(q->queue_lock); |
0c4de0f3 CH |
1292 | return rq; |
1293 | } | |
1da177e4 | 1294 | |
0c4de0f3 CH |
1295 | /* q->queue_lock is unlocked at this point */ |
1296 | rq->__data_len = 0; | |
1297 | rq->__sector = (sector_t) -1; | |
1298 | rq->bio = rq->biotail = NULL; | |
1da177e4 LT |
1299 | return rq; |
1300 | } | |
320ae51f JA |
1301 | |
1302 | struct request *blk_get_request(struct request_queue *q, int rw, gfp_t gfp_mask) | |
1303 | { | |
1304 | if (q->mq_ops) | |
6f3b0e8b CH |
1305 | return blk_mq_alloc_request(q, rw, |
1306 | (gfp_mask & __GFP_DIRECT_RECLAIM) ? | |
1307 | 0 : BLK_MQ_REQ_NOWAIT); | |
320ae51f JA |
1308 | else |
1309 | return blk_old_get_request(q, rw, gfp_mask); | |
1310 | } | |
1da177e4 LT |
1311 | EXPORT_SYMBOL(blk_get_request); |
1312 | ||
1313 | /** | |
1314 | * blk_requeue_request - put a request back on queue | |
1315 | * @q: request queue where request should be inserted | |
1316 | * @rq: request to be inserted | |
1317 | * | |
1318 | * Description: | |
1319 | * Drivers often keep queueing requests until the hardware cannot accept | |
1320 | * more, when that condition happens we need to put the request back | |
1321 | * on the queue. Must be called with queue lock held. | |
1322 | */ | |
165125e1 | 1323 | void blk_requeue_request(struct request_queue *q, struct request *rq) |
1da177e4 | 1324 | { |
242f9dcb JA |
1325 | blk_delete_timer(rq); |
1326 | blk_clear_rq_complete(rq); | |
5f3ea37c | 1327 | trace_block_rq_requeue(q, rq); |
87760e5e | 1328 | wbt_requeue(q->rq_wb, &rq->issue_stat); |
2056a782 | 1329 | |
e8064021 | 1330 | if (rq->rq_flags & RQF_QUEUED) |
1da177e4 LT |
1331 | blk_queue_end_tag(q, rq); |
1332 | ||
ba396a6c JB |
1333 | BUG_ON(blk_queued_rq(rq)); |
1334 | ||
1da177e4 LT |
1335 | elv_requeue_request(q, rq); |
1336 | } | |
1da177e4 LT |
1337 | EXPORT_SYMBOL(blk_requeue_request); |
1338 | ||
73c10101 JA |
1339 | static void add_acct_request(struct request_queue *q, struct request *rq, |
1340 | int where) | |
1341 | { | |
320ae51f | 1342 | blk_account_io_start(rq, true); |
7eaceacc | 1343 | __elv_add_request(q, rq, where); |
73c10101 JA |
1344 | } |
1345 | ||
074a7aca TH |
1346 | static void part_round_stats_single(int cpu, struct hd_struct *part, |
1347 | unsigned long now) | |
1348 | { | |
7276d02e JA |
1349 | int inflight; |
1350 | ||
074a7aca TH |
1351 | if (now == part->stamp) |
1352 | return; | |
1353 | ||
7276d02e JA |
1354 | inflight = part_in_flight(part); |
1355 | if (inflight) { | |
074a7aca | 1356 | __part_stat_add(cpu, part, time_in_queue, |
7276d02e | 1357 | inflight * (now - part->stamp)); |
074a7aca TH |
1358 | __part_stat_add(cpu, part, io_ticks, (now - part->stamp)); |
1359 | } | |
1360 | part->stamp = now; | |
1361 | } | |
1362 | ||
1363 | /** | |
496aa8a9 RD |
1364 | * part_round_stats() - Round off the performance stats on a struct disk_stats. |
1365 | * @cpu: cpu number for stats access | |
1366 | * @part: target partition | |
1da177e4 LT |
1367 | * |
1368 | * The average IO queue length and utilisation statistics are maintained | |
1369 | * by observing the current state of the queue length and the amount of | |
1370 | * time it has been in this state for. | |
1371 | * | |
1372 | * Normally, that accounting is done on IO completion, but that can result | |
1373 | * in more than a second's worth of IO being accounted for within any one | |
1374 | * second, leading to >100% utilisation. To deal with that, we call this | |
1375 | * function to do a round-off before returning the results when reading | |
1376 | * /proc/diskstats. This accounts immediately for all queue usage up to | |
1377 | * the current jiffies and restarts the counters again. | |
1378 | */ | |
c9959059 | 1379 | void part_round_stats(int cpu, struct hd_struct *part) |
6f2576af JM |
1380 | { |
1381 | unsigned long now = jiffies; | |
1382 | ||
074a7aca TH |
1383 | if (part->partno) |
1384 | part_round_stats_single(cpu, &part_to_disk(part)->part0, now); | |
1385 | part_round_stats_single(cpu, part, now); | |
6f2576af | 1386 | } |
074a7aca | 1387 | EXPORT_SYMBOL_GPL(part_round_stats); |
6f2576af | 1388 | |
47fafbc7 | 1389 | #ifdef CONFIG_PM |
c8158819 LM |
1390 | static void blk_pm_put_request(struct request *rq) |
1391 | { | |
e8064021 | 1392 | if (rq->q->dev && !(rq->rq_flags & RQF_PM) && !--rq->q->nr_pending) |
c8158819 LM |
1393 | pm_runtime_mark_last_busy(rq->q->dev); |
1394 | } | |
1395 | #else | |
1396 | static inline void blk_pm_put_request(struct request *rq) {} | |
1397 | #endif | |
1398 | ||
1da177e4 LT |
1399 | /* |
1400 | * queue lock must be held | |
1401 | */ | |
165125e1 | 1402 | void __blk_put_request(struct request_queue *q, struct request *req) |
1da177e4 | 1403 | { |
e8064021 CH |
1404 | req_flags_t rq_flags = req->rq_flags; |
1405 | ||
1da177e4 LT |
1406 | if (unlikely(!q)) |
1407 | return; | |
1da177e4 | 1408 | |
6f5ba581 CH |
1409 | if (q->mq_ops) { |
1410 | blk_mq_free_request(req); | |
1411 | return; | |
1412 | } | |
1413 | ||
c8158819 LM |
1414 | blk_pm_put_request(req); |
1415 | ||
8922e16c TH |
1416 | elv_completed_request(q, req); |
1417 | ||
1cd96c24 BH |
1418 | /* this is a bio leak */ |
1419 | WARN_ON(req->bio != NULL); | |
1420 | ||
87760e5e JA |
1421 | wbt_done(q->rq_wb, &req->issue_stat); |
1422 | ||
1da177e4 LT |
1423 | /* |
1424 | * Request may not have originated from ll_rw_blk. if not, | |
1425 | * it didn't come out of our reserved rq pools | |
1426 | */ | |
e8064021 | 1427 | if (rq_flags & RQF_ALLOCED) { |
a051661c | 1428 | struct request_list *rl = blk_rq_rl(req); |
ef295ecf | 1429 | bool sync = op_is_sync(req->cmd_flags); |
1da177e4 | 1430 | |
1da177e4 | 1431 | BUG_ON(!list_empty(&req->queuelist)); |
360f92c2 | 1432 | BUG_ON(ELV_ON_HASH(req)); |
1da177e4 | 1433 | |
a051661c | 1434 | blk_free_request(rl, req); |
e8064021 | 1435 | freed_request(rl, sync, rq_flags); |
a051661c | 1436 | blk_put_rl(rl); |
1da177e4 LT |
1437 | } |
1438 | } | |
6e39b69e MC |
1439 | EXPORT_SYMBOL_GPL(__blk_put_request); |
1440 | ||
1da177e4 LT |
1441 | void blk_put_request(struct request *req) |
1442 | { | |
165125e1 | 1443 | struct request_queue *q = req->q; |
8922e16c | 1444 | |
320ae51f JA |
1445 | if (q->mq_ops) |
1446 | blk_mq_free_request(req); | |
1447 | else { | |
1448 | unsigned long flags; | |
1449 | ||
1450 | spin_lock_irqsave(q->queue_lock, flags); | |
1451 | __blk_put_request(q, req); | |
1452 | spin_unlock_irqrestore(q->queue_lock, flags); | |
1453 | } | |
1da177e4 | 1454 | } |
1da177e4 LT |
1455 | EXPORT_SYMBOL(blk_put_request); |
1456 | ||
320ae51f JA |
1457 | bool bio_attempt_back_merge(struct request_queue *q, struct request *req, |
1458 | struct bio *bio) | |
73c10101 | 1459 | { |
1eff9d32 | 1460 | const int ff = bio->bi_opf & REQ_FAILFAST_MASK; |
73c10101 | 1461 | |
73c10101 JA |
1462 | if (!ll_back_merge_fn(q, req, bio)) |
1463 | return false; | |
1464 | ||
8c1cf6bb | 1465 | trace_block_bio_backmerge(q, req, bio); |
73c10101 JA |
1466 | |
1467 | if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff) | |
1468 | blk_rq_set_mixed_merge(req); | |
1469 | ||
1470 | req->biotail->bi_next = bio; | |
1471 | req->biotail = bio; | |
4f024f37 | 1472 | req->__data_len += bio->bi_iter.bi_size; |
73c10101 JA |
1473 | req->ioprio = ioprio_best(req->ioprio, bio_prio(bio)); |
1474 | ||
320ae51f | 1475 | blk_account_io_start(req, false); |
73c10101 JA |
1476 | return true; |
1477 | } | |
1478 | ||
320ae51f JA |
1479 | bool bio_attempt_front_merge(struct request_queue *q, struct request *req, |
1480 | struct bio *bio) | |
73c10101 | 1481 | { |
1eff9d32 | 1482 | const int ff = bio->bi_opf & REQ_FAILFAST_MASK; |
73c10101 | 1483 | |
73c10101 JA |
1484 | if (!ll_front_merge_fn(q, req, bio)) |
1485 | return false; | |
1486 | ||
8c1cf6bb | 1487 | trace_block_bio_frontmerge(q, req, bio); |
73c10101 JA |
1488 | |
1489 | if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff) | |
1490 | blk_rq_set_mixed_merge(req); | |
1491 | ||
73c10101 JA |
1492 | bio->bi_next = req->bio; |
1493 | req->bio = bio; | |
1494 | ||
4f024f37 KO |
1495 | req->__sector = bio->bi_iter.bi_sector; |
1496 | req->__data_len += bio->bi_iter.bi_size; | |
73c10101 JA |
1497 | req->ioprio = ioprio_best(req->ioprio, bio_prio(bio)); |
1498 | ||
320ae51f | 1499 | blk_account_io_start(req, false); |
73c10101 JA |
1500 | return true; |
1501 | } | |
1502 | ||
1e739730 CH |
1503 | bool bio_attempt_discard_merge(struct request_queue *q, struct request *req, |
1504 | struct bio *bio) | |
1505 | { | |
1506 | unsigned short segments = blk_rq_nr_discard_segments(req); | |
1507 | ||
1508 | if (segments >= queue_max_discard_segments(q)) | |
1509 | goto no_merge; | |
1510 | if (blk_rq_sectors(req) + bio_sectors(bio) > | |
1511 | blk_rq_get_max_sectors(req, blk_rq_pos(req))) | |
1512 | goto no_merge; | |
1513 | ||
1514 | req->biotail->bi_next = bio; | |
1515 | req->biotail = bio; | |
1516 | req->__data_len += bio->bi_iter.bi_size; | |
1517 | req->ioprio = ioprio_best(req->ioprio, bio_prio(bio)); | |
1518 | req->nr_phys_segments = segments + 1; | |
1519 | ||
1520 | blk_account_io_start(req, false); | |
1521 | return true; | |
1522 | no_merge: | |
1523 | req_set_nomerge(q, req); | |
1524 | return false; | |
1525 | } | |
1526 | ||
bd87b589 | 1527 | /** |
320ae51f | 1528 | * blk_attempt_plug_merge - try to merge with %current's plugged list |
bd87b589 TH |
1529 | * @q: request_queue new bio is being queued at |
1530 | * @bio: new bio being queued | |
1531 | * @request_count: out parameter for number of traversed plugged requests | |
ccc2600b RD |
1532 | * @same_queue_rq: pointer to &struct request that gets filled in when |
1533 | * another request associated with @q is found on the plug list | |
1534 | * (optional, may be %NULL) | |
bd87b589 TH |
1535 | * |
1536 | * Determine whether @bio being queued on @q can be merged with a request | |
1537 | * on %current's plugged list. Returns %true if merge was successful, | |
1538 | * otherwise %false. | |
1539 | * | |
07c2bd37 TH |
1540 | * Plugging coalesces IOs from the same issuer for the same purpose without |
1541 | * going through @q->queue_lock. As such it's more of an issuing mechanism | |
1542 | * than scheduling, and the request, while may have elvpriv data, is not | |
1543 | * added on the elevator at this point. In addition, we don't have | |
1544 | * reliable access to the elevator outside queue lock. Only check basic | |
1545 | * merging parameters without querying the elevator. | |
da41a589 RE |
1546 | * |
1547 | * Caller must ensure !blk_queue_nomerges(q) beforehand. | |
73c10101 | 1548 | */ |
320ae51f | 1549 | bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, |
5b3f341f SL |
1550 | unsigned int *request_count, |
1551 | struct request **same_queue_rq) | |
73c10101 JA |
1552 | { |
1553 | struct blk_plug *plug; | |
1554 | struct request *rq; | |
92f399c7 | 1555 | struct list_head *plug_list; |
73c10101 | 1556 | |
bd87b589 | 1557 | plug = current->plug; |
73c10101 | 1558 | if (!plug) |
34fe7c05 | 1559 | return false; |
56ebdaf2 | 1560 | *request_count = 0; |
73c10101 | 1561 | |
92f399c7 SL |
1562 | if (q->mq_ops) |
1563 | plug_list = &plug->mq_list; | |
1564 | else | |
1565 | plug_list = &plug->list; | |
1566 | ||
1567 | list_for_each_entry_reverse(rq, plug_list, queuelist) { | |
34fe7c05 | 1568 | bool merged = false; |
73c10101 | 1569 | |
5b3f341f | 1570 | if (rq->q == q) { |
1b2e19f1 | 1571 | (*request_count)++; |
5b3f341f SL |
1572 | /* |
1573 | * Only blk-mq multiple hardware queues case checks the | |
1574 | * rq in the same queue, there should be only one such | |
1575 | * rq in a queue | |
1576 | **/ | |
1577 | if (same_queue_rq) | |
1578 | *same_queue_rq = rq; | |
1579 | } | |
56ebdaf2 | 1580 | |
07c2bd37 | 1581 | if (rq->q != q || !blk_rq_merge_ok(rq, bio)) |
73c10101 JA |
1582 | continue; |
1583 | ||
34fe7c05 CH |
1584 | switch (blk_try_merge(rq, bio)) { |
1585 | case ELEVATOR_BACK_MERGE: | |
1586 | merged = bio_attempt_back_merge(q, rq, bio); | |
1587 | break; | |
1588 | case ELEVATOR_FRONT_MERGE: | |
1589 | merged = bio_attempt_front_merge(q, rq, bio); | |
1590 | break; | |
1e739730 CH |
1591 | case ELEVATOR_DISCARD_MERGE: |
1592 | merged = bio_attempt_discard_merge(q, rq, bio); | |
1593 | break; | |
34fe7c05 CH |
1594 | default: |
1595 | break; | |
73c10101 | 1596 | } |
34fe7c05 CH |
1597 | |
1598 | if (merged) | |
1599 | return true; | |
73c10101 | 1600 | } |
34fe7c05 CH |
1601 | |
1602 | return false; | |
73c10101 JA |
1603 | } |
1604 | ||
0809e3ac JM |
1605 | unsigned int blk_plug_queued_count(struct request_queue *q) |
1606 | { | |
1607 | struct blk_plug *plug; | |
1608 | struct request *rq; | |
1609 | struct list_head *plug_list; | |
1610 | unsigned int ret = 0; | |
1611 | ||
1612 | plug = current->plug; | |
1613 | if (!plug) | |
1614 | goto out; | |
1615 | ||
1616 | if (q->mq_ops) | |
1617 | plug_list = &plug->mq_list; | |
1618 | else | |
1619 | plug_list = &plug->list; | |
1620 | ||
1621 | list_for_each_entry(rq, plug_list, queuelist) { | |
1622 | if (rq->q == q) | |
1623 | ret++; | |
1624 | } | |
1625 | out: | |
1626 | return ret; | |
1627 | } | |
1628 | ||
da8d7f07 | 1629 | void blk_init_request_from_bio(struct request *req, struct bio *bio) |
52d9e675 | 1630 | { |
0be0dee6 BVA |
1631 | struct io_context *ioc = rq_ioc(bio); |
1632 | ||
1eff9d32 | 1633 | if (bio->bi_opf & REQ_RAHEAD) |
a82afdfc | 1634 | req->cmd_flags |= REQ_FAILFAST_MASK; |
b31dc66a | 1635 | |
4f024f37 | 1636 | req->__sector = bio->bi_iter.bi_sector; |
5dc8b362 AM |
1637 | if (ioprio_valid(bio_prio(bio))) |
1638 | req->ioprio = bio_prio(bio); | |
0be0dee6 BVA |
1639 | else if (ioc) |
1640 | req->ioprio = ioc->ioprio; | |
1641 | else | |
1642 | req->ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, 0); | |
bc1c56fd | 1643 | blk_rq_bio_prep(req->q, req, bio); |
52d9e675 | 1644 | } |
da8d7f07 | 1645 | EXPORT_SYMBOL_GPL(blk_init_request_from_bio); |
52d9e675 | 1646 | |
dece1635 | 1647 | static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio) |
1da177e4 | 1648 | { |
73c10101 | 1649 | struct blk_plug *plug; |
34fe7c05 | 1650 | int where = ELEVATOR_INSERT_SORT; |
e4d750c9 | 1651 | struct request *req, *free; |
56ebdaf2 | 1652 | unsigned int request_count = 0; |
87760e5e | 1653 | unsigned int wb_acct; |
1da177e4 | 1654 | |
1da177e4 LT |
1655 | /* |
1656 | * low level driver can indicate that it wants pages above a | |
1657 | * certain limit bounced to low memory (ie for highmem, or even | |
1658 | * ISA dma in theory) | |
1659 | */ | |
1660 | blk_queue_bounce(q, &bio); | |
1661 | ||
23688bf4 JN |
1662 | blk_queue_split(q, &bio, q->bio_split); |
1663 | ||
ffecfd1a | 1664 | if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { |
4246a0b6 CH |
1665 | bio->bi_error = -EIO; |
1666 | bio_endio(bio); | |
dece1635 | 1667 | return BLK_QC_T_NONE; |
ffecfd1a DW |
1668 | } |
1669 | ||
f73f44eb | 1670 | if (op_is_flush(bio->bi_opf)) { |
73c10101 | 1671 | spin_lock_irq(q->queue_lock); |
ae1b1539 | 1672 | where = ELEVATOR_INSERT_FLUSH; |
28e7d184 TH |
1673 | goto get_rq; |
1674 | } | |
1675 | ||
73c10101 JA |
1676 | /* |
1677 | * Check if we can merge with the plugged list before grabbing | |
1678 | * any locks. | |
1679 | */ | |
0809e3ac JM |
1680 | if (!blk_queue_nomerges(q)) { |
1681 | if (blk_attempt_plug_merge(q, bio, &request_count, NULL)) | |
dece1635 | 1682 | return BLK_QC_T_NONE; |
0809e3ac JM |
1683 | } else |
1684 | request_count = blk_plug_queued_count(q); | |
1da177e4 | 1685 | |
73c10101 | 1686 | spin_lock_irq(q->queue_lock); |
2056a782 | 1687 | |
34fe7c05 CH |
1688 | switch (elv_merge(q, &req, bio)) { |
1689 | case ELEVATOR_BACK_MERGE: | |
1690 | if (!bio_attempt_back_merge(q, req, bio)) | |
1691 | break; | |
1692 | elv_bio_merged(q, req, bio); | |
1693 | free = attempt_back_merge(q, req); | |
1694 | if (free) | |
1695 | __blk_put_request(q, free); | |
1696 | else | |
1697 | elv_merged_request(q, req, ELEVATOR_BACK_MERGE); | |
1698 | goto out_unlock; | |
1699 | case ELEVATOR_FRONT_MERGE: | |
1700 | if (!bio_attempt_front_merge(q, req, bio)) | |
1701 | break; | |
1702 | elv_bio_merged(q, req, bio); | |
1703 | free = attempt_front_merge(q, req); | |
1704 | if (free) | |
1705 | __blk_put_request(q, free); | |
1706 | else | |
1707 | elv_merged_request(q, req, ELEVATOR_FRONT_MERGE); | |
1708 | goto out_unlock; | |
1709 | default: | |
1710 | break; | |
1da177e4 LT |
1711 | } |
1712 | ||
450991bc | 1713 | get_rq: |
87760e5e JA |
1714 | wb_acct = wbt_wait(q->rq_wb, bio, q->queue_lock); |
1715 | ||
1da177e4 | 1716 | /* |
450991bc | 1717 | * Grab a free request. This is might sleep but can not fail. |
d6344532 | 1718 | * Returns with the queue unlocked. |
450991bc | 1719 | */ |
ef295ecf | 1720 | req = get_request(q, bio->bi_opf, bio, GFP_NOIO); |
a492f075 | 1721 | if (IS_ERR(req)) { |
87760e5e | 1722 | __wbt_done(q->rq_wb, wb_acct); |
4246a0b6 CH |
1723 | bio->bi_error = PTR_ERR(req); |
1724 | bio_endio(bio); | |
da8303c6 TH |
1725 | goto out_unlock; |
1726 | } | |
d6344532 | 1727 | |
87760e5e JA |
1728 | wbt_track(&req->issue_stat, wb_acct); |
1729 | ||
450991bc NP |
1730 | /* |
1731 | * After dropping the lock and possibly sleeping here, our request | |
1732 | * may now be mergeable after it had proven unmergeable (above). | |
1733 | * We don't worry about that case for efficiency. It won't happen | |
1734 | * often, and the elevators are able to handle it. | |
1da177e4 | 1735 | */ |
da8d7f07 | 1736 | blk_init_request_from_bio(req, bio); |
1da177e4 | 1737 | |
9562ad9a | 1738 | if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags)) |
11ccf116 | 1739 | req->cpu = raw_smp_processor_id(); |
73c10101 JA |
1740 | |
1741 | plug = current->plug; | |
721a9602 | 1742 | if (plug) { |
dc6d36c9 JA |
1743 | /* |
1744 | * If this is the first request added after a plug, fire | |
7aef2e78 | 1745 | * of a plug trace. |
0a6219a9 ML |
1746 | * |
1747 | * @request_count may become stale because of schedule | |
1748 | * out, so check plug list again. | |
dc6d36c9 | 1749 | */ |
0a6219a9 | 1750 | if (!request_count || list_empty(&plug->list)) |
dc6d36c9 | 1751 | trace_block_plug(q); |
3540d5e8 | 1752 | else { |
50d24c34 SL |
1753 | struct request *last = list_entry_rq(plug->list.prev); |
1754 | if (request_count >= BLK_MAX_REQUEST_COUNT || | |
1755 | blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE) { | |
3540d5e8 | 1756 | blk_flush_plug_list(plug, false); |
019ceb7d SL |
1757 | trace_block_plug(q); |
1758 | } | |
73c10101 | 1759 | } |
73c10101 | 1760 | list_add_tail(&req->queuelist, &plug->list); |
320ae51f | 1761 | blk_account_io_start(req, true); |
73c10101 JA |
1762 | } else { |
1763 | spin_lock_irq(q->queue_lock); | |
1764 | add_acct_request(q, req, where); | |
24ecfbe2 | 1765 | __blk_run_queue(q); |
73c10101 JA |
1766 | out_unlock: |
1767 | spin_unlock_irq(q->queue_lock); | |
1768 | } | |
dece1635 JA |
1769 | |
1770 | return BLK_QC_T_NONE; | |
1da177e4 LT |
1771 | } |
1772 | ||
1773 | /* | |
1774 | * If bio->bi_dev is a partition, remap the location | |
1775 | */ | |
1776 | static inline void blk_partition_remap(struct bio *bio) | |
1777 | { | |
1778 | struct block_device *bdev = bio->bi_bdev; | |
1779 | ||
778889d8 ST |
1780 | /* |
1781 | * Zone reset does not include bi_size so bio_sectors() is always 0. | |
1782 | * Include a test for the reset op code and perform the remap if needed. | |
1783 | */ | |
1784 | if (bdev != bdev->bd_contains && | |
1785 | (bio_sectors(bio) || bio_op(bio) == REQ_OP_ZONE_RESET)) { | |
1da177e4 LT |
1786 | struct hd_struct *p = bdev->bd_part; |
1787 | ||
4f024f37 | 1788 | bio->bi_iter.bi_sector += p->start_sect; |
1da177e4 | 1789 | bio->bi_bdev = bdev->bd_contains; |
c7149d6b | 1790 | |
d07335e5 MS |
1791 | trace_block_bio_remap(bdev_get_queue(bio->bi_bdev), bio, |
1792 | bdev->bd_dev, | |
4f024f37 | 1793 | bio->bi_iter.bi_sector - p->start_sect); |
1da177e4 LT |
1794 | } |
1795 | } | |
1796 | ||
1da177e4 LT |
1797 | static void handle_bad_sector(struct bio *bio) |
1798 | { | |
1799 | char b[BDEVNAME_SIZE]; | |
1800 | ||
1801 | printk(KERN_INFO "attempt to access beyond end of device\n"); | |
6296b960 | 1802 | printk(KERN_INFO "%s: rw=%d, want=%Lu, limit=%Lu\n", |
1da177e4 | 1803 | bdevname(bio->bi_bdev, b), |
1eff9d32 | 1804 | bio->bi_opf, |
f73a1c7d | 1805 | (unsigned long long)bio_end_sector(bio), |
77304d2a | 1806 | (long long)(i_size_read(bio->bi_bdev->bd_inode) >> 9)); |
1da177e4 LT |
1807 | } |
1808 | ||
c17bb495 AM |
1809 | #ifdef CONFIG_FAIL_MAKE_REQUEST |
1810 | ||
1811 | static DECLARE_FAULT_ATTR(fail_make_request); | |
1812 | ||
1813 | static int __init setup_fail_make_request(char *str) | |
1814 | { | |
1815 | return setup_fault_attr(&fail_make_request, str); | |
1816 | } | |
1817 | __setup("fail_make_request=", setup_fail_make_request); | |
1818 | ||
b2c9cd37 | 1819 | static bool should_fail_request(struct hd_struct *part, unsigned int bytes) |
c17bb495 | 1820 | { |
b2c9cd37 | 1821 | return part->make_it_fail && should_fail(&fail_make_request, bytes); |
c17bb495 AM |
1822 | } |
1823 | ||
1824 | static int __init fail_make_request_debugfs(void) | |
1825 | { | |
dd48c085 AM |
1826 | struct dentry *dir = fault_create_debugfs_attr("fail_make_request", |
1827 | NULL, &fail_make_request); | |
1828 | ||
21f9fcd8 | 1829 | return PTR_ERR_OR_ZERO(dir); |
c17bb495 AM |
1830 | } |
1831 | ||
1832 | late_initcall(fail_make_request_debugfs); | |
1833 | ||
1834 | #else /* CONFIG_FAIL_MAKE_REQUEST */ | |
1835 | ||
b2c9cd37 AM |
1836 | static inline bool should_fail_request(struct hd_struct *part, |
1837 | unsigned int bytes) | |
c17bb495 | 1838 | { |
b2c9cd37 | 1839 | return false; |
c17bb495 AM |
1840 | } |
1841 | ||
1842 | #endif /* CONFIG_FAIL_MAKE_REQUEST */ | |
1843 | ||
c07e2b41 JA |
1844 | /* |
1845 | * Check whether this bio extends beyond the end of the device. | |
1846 | */ | |
1847 | static inline int bio_check_eod(struct bio *bio, unsigned int nr_sectors) | |
1848 | { | |
1849 | sector_t maxsector; | |
1850 | ||
1851 | if (!nr_sectors) | |
1852 | return 0; | |
1853 | ||
1854 | /* Test device or partition size, when known. */ | |
77304d2a | 1855 | maxsector = i_size_read(bio->bi_bdev->bd_inode) >> 9; |
c07e2b41 | 1856 | if (maxsector) { |
4f024f37 | 1857 | sector_t sector = bio->bi_iter.bi_sector; |
c07e2b41 JA |
1858 | |
1859 | if (maxsector < nr_sectors || maxsector - nr_sectors < sector) { | |
1860 | /* | |
1861 | * This may well happen - the kernel calls bread() | |
1862 | * without checking the size of the device, e.g., when | |
1863 | * mounting a device. | |
1864 | */ | |
1865 | handle_bad_sector(bio); | |
1866 | return 1; | |
1867 | } | |
1868 | } | |
1869 | ||
1870 | return 0; | |
1871 | } | |
1872 | ||
27a84d54 CH |
1873 | static noinline_for_stack bool |
1874 | generic_make_request_checks(struct bio *bio) | |
1da177e4 | 1875 | { |
165125e1 | 1876 | struct request_queue *q; |
5a7bbad2 | 1877 | int nr_sectors = bio_sectors(bio); |
51fd77bd | 1878 | int err = -EIO; |
5a7bbad2 CH |
1879 | char b[BDEVNAME_SIZE]; |
1880 | struct hd_struct *part; | |
1da177e4 LT |
1881 | |
1882 | might_sleep(); | |
1da177e4 | 1883 | |
c07e2b41 JA |
1884 | if (bio_check_eod(bio, nr_sectors)) |
1885 | goto end_io; | |
1da177e4 | 1886 | |
5a7bbad2 CH |
1887 | q = bdev_get_queue(bio->bi_bdev); |
1888 | if (unlikely(!q)) { | |
1889 | printk(KERN_ERR | |
1890 | "generic_make_request: Trying to access " | |
1891 | "nonexistent block-device %s (%Lu)\n", | |
1892 | bdevname(bio->bi_bdev, b), | |
4f024f37 | 1893 | (long long) bio->bi_iter.bi_sector); |
5a7bbad2 CH |
1894 | goto end_io; |
1895 | } | |
c17bb495 | 1896 | |
5a7bbad2 | 1897 | part = bio->bi_bdev->bd_part; |
4f024f37 | 1898 | if (should_fail_request(part, bio->bi_iter.bi_size) || |
5a7bbad2 | 1899 | should_fail_request(&part_to_disk(part)->part0, |
4f024f37 | 1900 | bio->bi_iter.bi_size)) |
5a7bbad2 | 1901 | goto end_io; |
2056a782 | 1902 | |
5a7bbad2 CH |
1903 | /* |
1904 | * If this device has partitions, remap block n | |
1905 | * of partition p to block n+start(p) of the disk. | |
1906 | */ | |
1907 | blk_partition_remap(bio); | |
2056a782 | 1908 | |
5a7bbad2 CH |
1909 | if (bio_check_eod(bio, nr_sectors)) |
1910 | goto end_io; | |
1e87901e | 1911 | |
5a7bbad2 CH |
1912 | /* |
1913 | * Filter flush bio's early so that make_request based | |
1914 | * drivers without flush support don't have to worry | |
1915 | * about them. | |
1916 | */ | |
f3a8ab7d | 1917 | if (op_is_flush(bio->bi_opf) && |
c888a8f9 | 1918 | !test_bit(QUEUE_FLAG_WC, &q->queue_flags)) { |
1eff9d32 | 1919 | bio->bi_opf &= ~(REQ_PREFLUSH | REQ_FUA); |
5a7bbad2 CH |
1920 | if (!nr_sectors) { |
1921 | err = 0; | |
51fd77bd JA |
1922 | goto end_io; |
1923 | } | |
5a7bbad2 | 1924 | } |
5ddfe969 | 1925 | |
288dab8a CH |
1926 | switch (bio_op(bio)) { |
1927 | case REQ_OP_DISCARD: | |
1928 | if (!blk_queue_discard(q)) | |
1929 | goto not_supported; | |
1930 | break; | |
1931 | case REQ_OP_SECURE_ERASE: | |
1932 | if (!blk_queue_secure_erase(q)) | |
1933 | goto not_supported; | |
1934 | break; | |
1935 | case REQ_OP_WRITE_SAME: | |
1936 | if (!bdev_write_same(bio->bi_bdev)) | |
1937 | goto not_supported; | |
58886785 | 1938 | break; |
2d253440 ST |
1939 | case REQ_OP_ZONE_REPORT: |
1940 | case REQ_OP_ZONE_RESET: | |
1941 | if (!bdev_is_zoned(bio->bi_bdev)) | |
1942 | goto not_supported; | |
288dab8a | 1943 | break; |
a6f0788e CK |
1944 | case REQ_OP_WRITE_ZEROES: |
1945 | if (!bdev_write_zeroes_sectors(bio->bi_bdev)) | |
1946 | goto not_supported; | |
1947 | break; | |
288dab8a CH |
1948 | default: |
1949 | break; | |
5a7bbad2 | 1950 | } |
01edede4 | 1951 | |
7f4b35d1 TH |
1952 | /* |
1953 | * Various block parts want %current->io_context and lazy ioc | |
1954 | * allocation ends up trading a lot of pain for a small amount of | |
1955 | * memory. Just allocate it upfront. This may fail and block | |
1956 | * layer knows how to live with it. | |
1957 | */ | |
1958 | create_io_context(GFP_ATOMIC, q->node); | |
1959 | ||
ae118896 TH |
1960 | if (!blkcg_bio_issue_check(q, bio)) |
1961 | return false; | |
27a84d54 | 1962 | |
fbbaf700 N |
1963 | if (!bio_flagged(bio, BIO_TRACE_COMPLETION)) { |
1964 | trace_block_bio_queue(q, bio); | |
1965 | /* Now that enqueuing has been traced, we need to trace | |
1966 | * completion as well. | |
1967 | */ | |
1968 | bio_set_flag(bio, BIO_TRACE_COMPLETION); | |
1969 | } | |
27a84d54 | 1970 | return true; |
a7384677 | 1971 | |
288dab8a CH |
1972 | not_supported: |
1973 | err = -EOPNOTSUPP; | |
a7384677 | 1974 | end_io: |
4246a0b6 CH |
1975 | bio->bi_error = err; |
1976 | bio_endio(bio); | |
27a84d54 | 1977 | return false; |
1da177e4 LT |
1978 | } |
1979 | ||
27a84d54 CH |
1980 | /** |
1981 | * generic_make_request - hand a buffer to its device driver for I/O | |
1982 | * @bio: The bio describing the location in memory and on the device. | |
1983 | * | |
1984 | * generic_make_request() is used to make I/O requests of block | |
1985 | * devices. It is passed a &struct bio, which describes the I/O that needs | |
1986 | * to be done. | |
1987 | * | |
1988 | * generic_make_request() does not return any status. The | |
1989 | * success/failure status of the request, along with notification of | |
1990 | * completion, is delivered asynchronously through the bio->bi_end_io | |
1991 | * function described (one day) else where. | |
1992 | * | |
1993 | * The caller of generic_make_request must make sure that bi_io_vec | |
1994 | * are set to describe the memory buffer, and that bi_dev and bi_sector are | |
1995 | * set to describe the device address, and the | |
1996 | * bi_end_io and optionally bi_private are set to describe how | |
1997 | * completion notification should be signaled. | |
1998 | * | |
1999 | * generic_make_request and the drivers it calls may use bi_next if this | |
2000 | * bio happens to be merged with someone else, and may resubmit the bio to | |
2001 | * a lower device by calling into generic_make_request recursively, which | |
2002 | * means the bio should NOT be touched after the call to ->make_request_fn. | |
d89d8796 | 2003 | */ |
dece1635 | 2004 | blk_qc_t generic_make_request(struct bio *bio) |
d89d8796 | 2005 | { |
f5fe1b51 N |
2006 | /* |
2007 | * bio_list_on_stack[0] contains bios submitted by the current | |
2008 | * make_request_fn. | |
2009 | * bio_list_on_stack[1] contains bios that were submitted before | |
2010 | * the current make_request_fn, but that haven't been processed | |
2011 | * yet. | |
2012 | */ | |
2013 | struct bio_list bio_list_on_stack[2]; | |
dece1635 | 2014 | blk_qc_t ret = BLK_QC_T_NONE; |
bddd87c7 | 2015 | |
27a84d54 | 2016 | if (!generic_make_request_checks(bio)) |
dece1635 | 2017 | goto out; |
27a84d54 CH |
2018 | |
2019 | /* | |
2020 | * We only want one ->make_request_fn to be active at a time, else | |
2021 | * stack usage with stacked devices could be a problem. So use | |
2022 | * current->bio_list to keep a list of requests submited by a | |
2023 | * make_request_fn function. current->bio_list is also used as a | |
2024 | * flag to say if generic_make_request is currently active in this | |
2025 | * task or not. If it is NULL, then no make_request is active. If | |
2026 | * it is non-NULL, then a make_request is active, and new requests | |
2027 | * should be added at the tail | |
2028 | */ | |
bddd87c7 | 2029 | if (current->bio_list) { |
f5fe1b51 | 2030 | bio_list_add(¤t->bio_list[0], bio); |
dece1635 | 2031 | goto out; |
d89d8796 | 2032 | } |
27a84d54 | 2033 | |
d89d8796 NB |
2034 | /* following loop may be a bit non-obvious, and so deserves some |
2035 | * explanation. | |
2036 | * Before entering the loop, bio->bi_next is NULL (as all callers | |
2037 | * ensure that) so we have a list with a single bio. | |
2038 | * We pretend that we have just taken it off a longer list, so | |
bddd87c7 AM |
2039 | * we assign bio_list to a pointer to the bio_list_on_stack, |
2040 | * thus initialising the bio_list of new bios to be | |
27a84d54 | 2041 | * added. ->make_request() may indeed add some more bios |
d89d8796 NB |
2042 | * through a recursive call to generic_make_request. If it |
2043 | * did, we find a non-NULL value in bio_list and re-enter the loop | |
2044 | * from the top. In this case we really did just take the bio | |
bddd87c7 | 2045 | * of the top of the list (no pretending) and so remove it from |
27a84d54 | 2046 | * bio_list, and call into ->make_request() again. |
d89d8796 NB |
2047 | */ |
2048 | BUG_ON(bio->bi_next); | |
f5fe1b51 N |
2049 | bio_list_init(&bio_list_on_stack[0]); |
2050 | current->bio_list = bio_list_on_stack; | |
d89d8796 | 2051 | do { |
27a84d54 CH |
2052 | struct request_queue *q = bdev_get_queue(bio->bi_bdev); |
2053 | ||
6f3b0e8b | 2054 | if (likely(blk_queue_enter(q, false) == 0)) { |
79bd9959 N |
2055 | struct bio_list lower, same; |
2056 | ||
2057 | /* Create a fresh bio_list for all subordinate requests */ | |
f5fe1b51 N |
2058 | bio_list_on_stack[1] = bio_list_on_stack[0]; |
2059 | bio_list_init(&bio_list_on_stack[0]); | |
dece1635 | 2060 | ret = q->make_request_fn(q, bio); |
3ef28e83 DW |
2061 | |
2062 | blk_queue_exit(q); | |
27a84d54 | 2063 | |
79bd9959 N |
2064 | /* sort new bios into those for a lower level |
2065 | * and those for the same level | |
2066 | */ | |
2067 | bio_list_init(&lower); | |
2068 | bio_list_init(&same); | |
f5fe1b51 | 2069 | while ((bio = bio_list_pop(&bio_list_on_stack[0])) != NULL) |
79bd9959 N |
2070 | if (q == bdev_get_queue(bio->bi_bdev)) |
2071 | bio_list_add(&same, bio); | |
2072 | else | |
2073 | bio_list_add(&lower, bio); | |
2074 | /* now assemble so we handle the lowest level first */ | |
f5fe1b51 N |
2075 | bio_list_merge(&bio_list_on_stack[0], &lower); |
2076 | bio_list_merge(&bio_list_on_stack[0], &same); | |
2077 | bio_list_merge(&bio_list_on_stack[0], &bio_list_on_stack[1]); | |
3ef28e83 | 2078 | } else { |
3ef28e83 | 2079 | bio_io_error(bio); |
3ef28e83 | 2080 | } |
f5fe1b51 | 2081 | bio = bio_list_pop(&bio_list_on_stack[0]); |
d89d8796 | 2082 | } while (bio); |
bddd87c7 | 2083 | current->bio_list = NULL; /* deactivate */ |
dece1635 JA |
2084 | |
2085 | out: | |
2086 | return ret; | |
d89d8796 | 2087 | } |
1da177e4 LT |
2088 | EXPORT_SYMBOL(generic_make_request); |
2089 | ||
2090 | /** | |
710027a4 | 2091 | * submit_bio - submit a bio to the block device layer for I/O |
1da177e4 LT |
2092 | * @bio: The &struct bio which describes the I/O |
2093 | * | |
2094 | * submit_bio() is very similar in purpose to generic_make_request(), and | |
2095 | * uses that function to do most of the work. Both are fairly rough | |
710027a4 | 2096 | * interfaces; @bio must be presetup and ready for I/O. |
1da177e4 LT |
2097 | * |
2098 | */ | |
4e49ea4a | 2099 | blk_qc_t submit_bio(struct bio *bio) |
1da177e4 | 2100 | { |
bf2de6f5 JA |
2101 | /* |
2102 | * If it's a regular read/write or a barrier with data attached, | |
2103 | * go through the normal accounting stuff before submission. | |
2104 | */ | |
e2a60da7 | 2105 | if (bio_has_data(bio)) { |
4363ac7c MP |
2106 | unsigned int count; |
2107 | ||
95fe6c1a | 2108 | if (unlikely(bio_op(bio) == REQ_OP_WRITE_SAME)) |
4363ac7c MP |
2109 | count = bdev_logical_block_size(bio->bi_bdev) >> 9; |
2110 | else | |
2111 | count = bio_sectors(bio); | |
2112 | ||
a8ebb056 | 2113 | if (op_is_write(bio_op(bio))) { |
bf2de6f5 JA |
2114 | count_vm_events(PGPGOUT, count); |
2115 | } else { | |
4f024f37 | 2116 | task_io_account_read(bio->bi_iter.bi_size); |
bf2de6f5 JA |
2117 | count_vm_events(PGPGIN, count); |
2118 | } | |
2119 | ||
2120 | if (unlikely(block_dump)) { | |
2121 | char b[BDEVNAME_SIZE]; | |
8dcbdc74 | 2122 | printk(KERN_DEBUG "%s(%d): %s block %Lu on %s (%u sectors)\n", |
ba25f9dc | 2123 | current->comm, task_pid_nr(current), |
a8ebb056 | 2124 | op_is_write(bio_op(bio)) ? "WRITE" : "READ", |
4f024f37 | 2125 | (unsigned long long)bio->bi_iter.bi_sector, |
8dcbdc74 SM |
2126 | bdevname(bio->bi_bdev, b), |
2127 | count); | |
bf2de6f5 | 2128 | } |
1da177e4 LT |
2129 | } |
2130 | ||
dece1635 | 2131 | return generic_make_request(bio); |
1da177e4 | 2132 | } |
1da177e4 LT |
2133 | EXPORT_SYMBOL(submit_bio); |
2134 | ||
82124d60 | 2135 | /** |
bf4e6b4e HR |
2136 | * blk_cloned_rq_check_limits - Helper function to check a cloned request |
2137 | * for new the queue limits | |
82124d60 KU |
2138 | * @q: the queue |
2139 | * @rq: the request being checked | |
2140 | * | |
2141 | * Description: | |
2142 | * @rq may have been made based on weaker limitations of upper-level queues | |
2143 | * in request stacking drivers, and it may violate the limitation of @q. | |
2144 | * Since the block layer and the underlying device driver trust @rq | |
2145 | * after it is inserted to @q, it should be checked against @q before | |
2146 | * the insertion using this generic function. | |
2147 | * | |
82124d60 | 2148 | * Request stacking drivers like request-based dm may change the queue |
bf4e6b4e HR |
2149 | * limits when retrying requests on other queues. Those requests need |
2150 | * to be checked against the new queue limits again during dispatch. | |
82124d60 | 2151 | */ |
bf4e6b4e HR |
2152 | static int blk_cloned_rq_check_limits(struct request_queue *q, |
2153 | struct request *rq) | |
82124d60 | 2154 | { |
8fe0d473 | 2155 | if (blk_rq_sectors(rq) > blk_queue_get_max_sectors(q, req_op(rq))) { |
82124d60 KU |
2156 | printk(KERN_ERR "%s: over max size limit.\n", __func__); |
2157 | return -EIO; | |
2158 | } | |
2159 | ||
2160 | /* | |
2161 | * queue's settings related to segment counting like q->bounce_pfn | |
2162 | * may differ from that of other stacking queues. | |
2163 | * Recalculate it to check the request correctly on this queue's | |
2164 | * limitation. | |
2165 | */ | |
2166 | blk_recalc_rq_segments(rq); | |
8a78362c | 2167 | if (rq->nr_phys_segments > queue_max_segments(q)) { |
82124d60 KU |
2168 | printk(KERN_ERR "%s: over max segments limit.\n", __func__); |
2169 | return -EIO; | |
2170 | } | |
2171 | ||
2172 | return 0; | |
2173 | } | |
82124d60 KU |
2174 | |
2175 | /** | |
2176 | * blk_insert_cloned_request - Helper for stacking drivers to submit a request | |
2177 | * @q: the queue to submit the request | |
2178 | * @rq: the request being queued | |
2179 | */ | |
2180 | int blk_insert_cloned_request(struct request_queue *q, struct request *rq) | |
2181 | { | |
2182 | unsigned long flags; | |
4853abaa | 2183 | int where = ELEVATOR_INSERT_BACK; |
82124d60 | 2184 | |
bf4e6b4e | 2185 | if (blk_cloned_rq_check_limits(q, rq)) |
82124d60 KU |
2186 | return -EIO; |
2187 | ||
b2c9cd37 AM |
2188 | if (rq->rq_disk && |
2189 | should_fail_request(&rq->rq_disk->part0, blk_rq_bytes(rq))) | |
82124d60 | 2190 | return -EIO; |
82124d60 | 2191 | |
7fb4898e KB |
2192 | if (q->mq_ops) { |
2193 | if (blk_queue_io_stat(q)) | |
2194 | blk_account_io_start(rq, true); | |
bd6737f1 | 2195 | blk_mq_sched_insert_request(rq, false, true, false, false); |
7fb4898e KB |
2196 | return 0; |
2197 | } | |
2198 | ||
82124d60 | 2199 | spin_lock_irqsave(q->queue_lock, flags); |
3f3299d5 | 2200 | if (unlikely(blk_queue_dying(q))) { |
8ba61435 TH |
2201 | spin_unlock_irqrestore(q->queue_lock, flags); |
2202 | return -ENODEV; | |
2203 | } | |
82124d60 KU |
2204 | |
2205 | /* | |
2206 | * Submitting request must be dequeued before calling this function | |
2207 | * because it will be linked to another request_queue | |
2208 | */ | |
2209 | BUG_ON(blk_queued_rq(rq)); | |
2210 | ||
f73f44eb | 2211 | if (op_is_flush(rq->cmd_flags)) |
4853abaa JM |
2212 | where = ELEVATOR_INSERT_FLUSH; |
2213 | ||
2214 | add_acct_request(q, rq, where); | |
e67b77c7 JM |
2215 | if (where == ELEVATOR_INSERT_FLUSH) |
2216 | __blk_run_queue(q); | |
82124d60 KU |
2217 | spin_unlock_irqrestore(q->queue_lock, flags); |
2218 | ||
2219 | return 0; | |
2220 | } | |
2221 | EXPORT_SYMBOL_GPL(blk_insert_cloned_request); | |
2222 | ||
80a761fd TH |
2223 | /** |
2224 | * blk_rq_err_bytes - determine number of bytes till the next failure boundary | |
2225 | * @rq: request to examine | |
2226 | * | |
2227 | * Description: | |
2228 | * A request could be merge of IOs which require different failure | |
2229 | * handling. This function determines the number of bytes which | |
2230 | * can be failed from the beginning of the request without | |
2231 | * crossing into area which need to be retried further. | |
2232 | * | |
2233 | * Return: | |
2234 | * The number of bytes to fail. | |
2235 | * | |
2236 | * Context: | |
2237 | * queue_lock must be held. | |
2238 | */ | |
2239 | unsigned int blk_rq_err_bytes(const struct request *rq) | |
2240 | { | |
2241 | unsigned int ff = rq->cmd_flags & REQ_FAILFAST_MASK; | |
2242 | unsigned int bytes = 0; | |
2243 | struct bio *bio; | |
2244 | ||
e8064021 | 2245 | if (!(rq->rq_flags & RQF_MIXED_MERGE)) |
80a761fd TH |
2246 | return blk_rq_bytes(rq); |
2247 | ||
2248 | /* | |
2249 | * Currently the only 'mixing' which can happen is between | |
2250 | * different fastfail types. We can safely fail portions | |
2251 | * which have all the failfast bits that the first one has - | |
2252 | * the ones which are at least as eager to fail as the first | |
2253 | * one. | |
2254 | */ | |
2255 | for (bio = rq->bio; bio; bio = bio->bi_next) { | |
1eff9d32 | 2256 | if ((bio->bi_opf & ff) != ff) |
80a761fd | 2257 | break; |
4f024f37 | 2258 | bytes += bio->bi_iter.bi_size; |
80a761fd TH |
2259 | } |
2260 | ||
2261 | /* this could lead to infinite loop */ | |
2262 | BUG_ON(blk_rq_bytes(rq) && !bytes); | |
2263 | return bytes; | |
2264 | } | |
2265 | EXPORT_SYMBOL_GPL(blk_rq_err_bytes); | |
2266 | ||
320ae51f | 2267 | void blk_account_io_completion(struct request *req, unsigned int bytes) |
bc58ba94 | 2268 | { |
c2553b58 | 2269 | if (blk_do_io_stat(req)) { |
bc58ba94 JA |
2270 | const int rw = rq_data_dir(req); |
2271 | struct hd_struct *part; | |
2272 | int cpu; | |
2273 | ||
2274 | cpu = part_stat_lock(); | |
09e099d4 | 2275 | part = req->part; |
bc58ba94 JA |
2276 | part_stat_add(cpu, part, sectors[rw], bytes >> 9); |
2277 | part_stat_unlock(); | |
2278 | } | |
2279 | } | |
2280 | ||
320ae51f | 2281 | void blk_account_io_done(struct request *req) |
bc58ba94 | 2282 | { |
bc58ba94 | 2283 | /* |
dd4c133f TH |
2284 | * Account IO completion. flush_rq isn't accounted as a |
2285 | * normal IO on queueing nor completion. Accounting the | |
2286 | * containing request is enough. | |
bc58ba94 | 2287 | */ |
e8064021 | 2288 | if (blk_do_io_stat(req) && !(req->rq_flags & RQF_FLUSH_SEQ)) { |
bc58ba94 JA |
2289 | unsigned long duration = jiffies - req->start_time; |
2290 | const int rw = rq_data_dir(req); | |
2291 | struct hd_struct *part; | |
2292 | int cpu; | |
2293 | ||
2294 | cpu = part_stat_lock(); | |
09e099d4 | 2295 | part = req->part; |
bc58ba94 JA |
2296 | |
2297 | part_stat_inc(cpu, part, ios[rw]); | |
2298 | part_stat_add(cpu, part, ticks[rw], duration); | |
2299 | part_round_stats(cpu, part); | |
316d315b | 2300 | part_dec_in_flight(part, rw); |
bc58ba94 | 2301 | |
6c23a968 | 2302 | hd_struct_put(part); |
bc58ba94 JA |
2303 | part_stat_unlock(); |
2304 | } | |
2305 | } | |
2306 | ||
47fafbc7 | 2307 | #ifdef CONFIG_PM |
c8158819 LM |
2308 | /* |
2309 | * Don't process normal requests when queue is suspended | |
2310 | * or in the process of suspending/resuming | |
2311 | */ | |
2312 | static struct request *blk_pm_peek_request(struct request_queue *q, | |
2313 | struct request *rq) | |
2314 | { | |
2315 | if (q->dev && (q->rpm_status == RPM_SUSPENDED || | |
e8064021 | 2316 | (q->rpm_status != RPM_ACTIVE && !(rq->rq_flags & RQF_PM)))) |
c8158819 LM |
2317 | return NULL; |
2318 | else | |
2319 | return rq; | |
2320 | } | |
2321 | #else | |
2322 | static inline struct request *blk_pm_peek_request(struct request_queue *q, | |
2323 | struct request *rq) | |
2324 | { | |
2325 | return rq; | |
2326 | } | |
2327 | #endif | |
2328 | ||
320ae51f JA |
2329 | void blk_account_io_start(struct request *rq, bool new_io) |
2330 | { | |
2331 | struct hd_struct *part; | |
2332 | int rw = rq_data_dir(rq); | |
2333 | int cpu; | |
2334 | ||
2335 | if (!blk_do_io_stat(rq)) | |
2336 | return; | |
2337 | ||
2338 | cpu = part_stat_lock(); | |
2339 | ||
2340 | if (!new_io) { | |
2341 | part = rq->part; | |
2342 | part_stat_inc(cpu, part, merges[rw]); | |
2343 | } else { | |
2344 | part = disk_map_sector_rcu(rq->rq_disk, blk_rq_pos(rq)); | |
2345 | if (!hd_struct_try_get(part)) { | |
2346 | /* | |
2347 | * The partition is already being removed, | |
2348 | * the request will be accounted on the disk only | |
2349 | * | |
2350 | * We take a reference on disk->part0 although that | |
2351 | * partition will never be deleted, so we can treat | |
2352 | * it as any other partition. | |
2353 | */ | |
2354 | part = &rq->rq_disk->part0; | |
2355 | hd_struct_get(part); | |
2356 | } | |
2357 | part_round_stats(cpu, part); | |
2358 | part_inc_in_flight(part, rw); | |
2359 | rq->part = part; | |
2360 | } | |
2361 | ||
2362 | part_stat_unlock(); | |
2363 | } | |
2364 | ||
3bcddeac | 2365 | /** |
9934c8c0 TH |
2366 | * blk_peek_request - peek at the top of a request queue |
2367 | * @q: request queue to peek at | |
2368 | * | |
2369 | * Description: | |
2370 | * Return the request at the top of @q. The returned request | |
2371 | * should be started using blk_start_request() before LLD starts | |
2372 | * processing it. | |
2373 | * | |
2374 | * Return: | |
2375 | * Pointer to the request at the top of @q if available. Null | |
2376 | * otherwise. | |
2377 | * | |
2378 | * Context: | |
2379 | * queue_lock must be held. | |
2380 | */ | |
2381 | struct request *blk_peek_request(struct request_queue *q) | |
158dbda0 TH |
2382 | { |
2383 | struct request *rq; | |
2384 | int ret; | |
2385 | ||
2386 | while ((rq = __elv_next_request(q)) != NULL) { | |
c8158819 LM |
2387 | |
2388 | rq = blk_pm_peek_request(q, rq); | |
2389 | if (!rq) | |
2390 | break; | |
2391 | ||
e8064021 | 2392 | if (!(rq->rq_flags & RQF_STARTED)) { |
158dbda0 TH |
2393 | /* |
2394 | * This is the first time the device driver | |
2395 | * sees this request (possibly after | |
2396 | * requeueing). Notify IO scheduler. | |
2397 | */ | |
e8064021 | 2398 | if (rq->rq_flags & RQF_SORTED) |
158dbda0 TH |
2399 | elv_activate_rq(q, rq); |
2400 | ||
2401 | /* | |
2402 | * just mark as started even if we don't start | |
2403 | * it, a request that has been delayed should | |
2404 | * not be passed by new incoming requests | |
2405 | */ | |
e8064021 | 2406 | rq->rq_flags |= RQF_STARTED; |
158dbda0 TH |
2407 | trace_block_rq_issue(q, rq); |
2408 | } | |
2409 | ||
2410 | if (!q->boundary_rq || q->boundary_rq == rq) { | |
2411 | q->end_sector = rq_end_sector(rq); | |
2412 | q->boundary_rq = NULL; | |
2413 | } | |
2414 | ||
e8064021 | 2415 | if (rq->rq_flags & RQF_DONTPREP) |
158dbda0 TH |
2416 | break; |
2417 | ||
2e46e8b2 | 2418 | if (q->dma_drain_size && blk_rq_bytes(rq)) { |
158dbda0 TH |
2419 | /* |
2420 | * make sure space for the drain appears we | |
2421 | * know we can do this because max_hw_segments | |
2422 | * has been adjusted to be one fewer than the | |
2423 | * device can handle | |
2424 | */ | |
2425 | rq->nr_phys_segments++; | |
2426 | } | |
2427 | ||
2428 | if (!q->prep_rq_fn) | |
2429 | break; | |
2430 | ||
2431 | ret = q->prep_rq_fn(q, rq); | |
2432 | if (ret == BLKPREP_OK) { | |
2433 | break; | |
2434 | } else if (ret == BLKPREP_DEFER) { | |
2435 | /* | |
2436 | * the request may have been (partially) prepped. | |
2437 | * we need to keep this request in the front to | |
e8064021 | 2438 | * avoid resource deadlock. RQF_STARTED will |
158dbda0 TH |
2439 | * prevent other fs requests from passing this one. |
2440 | */ | |
2e46e8b2 | 2441 | if (q->dma_drain_size && blk_rq_bytes(rq) && |
e8064021 | 2442 | !(rq->rq_flags & RQF_DONTPREP)) { |
158dbda0 TH |
2443 | /* |
2444 | * remove the space for the drain we added | |
2445 | * so that we don't add it again | |
2446 | */ | |
2447 | --rq->nr_phys_segments; | |
2448 | } | |
2449 | ||
2450 | rq = NULL; | |
2451 | break; | |
0fb5b1fb MP |
2452 | } else if (ret == BLKPREP_KILL || ret == BLKPREP_INVALID) { |
2453 | int err = (ret == BLKPREP_INVALID) ? -EREMOTEIO : -EIO; | |
2454 | ||
e8064021 | 2455 | rq->rq_flags |= RQF_QUIET; |
c143dc90 JB |
2456 | /* |
2457 | * Mark this request as started so we don't trigger | |
2458 | * any debug logic in the end I/O path. | |
2459 | */ | |
2460 | blk_start_request(rq); | |
0fb5b1fb | 2461 | __blk_end_request_all(rq, err); |
158dbda0 TH |
2462 | } else { |
2463 | printk(KERN_ERR "%s: bad return=%d\n", __func__, ret); | |
2464 | break; | |
2465 | } | |
2466 | } | |
2467 | ||
2468 | return rq; | |
2469 | } | |
9934c8c0 | 2470 | EXPORT_SYMBOL(blk_peek_request); |
158dbda0 | 2471 | |
9934c8c0 | 2472 | void blk_dequeue_request(struct request *rq) |
158dbda0 | 2473 | { |
9934c8c0 TH |
2474 | struct request_queue *q = rq->q; |
2475 | ||
158dbda0 TH |
2476 | BUG_ON(list_empty(&rq->queuelist)); |
2477 | BUG_ON(ELV_ON_HASH(rq)); | |
2478 | ||
2479 | list_del_init(&rq->queuelist); | |
2480 | ||
2481 | /* | |
2482 | * the time frame between a request being removed from the lists | |
2483 | * and to it is freed is accounted as io that is in progress at | |
2484 | * the driver side. | |
2485 | */ | |
9195291e | 2486 | if (blk_account_rq(rq)) { |
0a7ae2ff | 2487 | q->in_flight[rq_is_sync(rq)]++; |
9195291e DS |
2488 | set_io_start_time_ns(rq); |
2489 | } | |
158dbda0 TH |
2490 | } |
2491 | ||
9934c8c0 TH |
2492 | /** |
2493 | * blk_start_request - start request processing on the driver | |
2494 | * @req: request to dequeue | |
2495 | * | |
2496 | * Description: | |
2497 | * Dequeue @req and start timeout timer on it. This hands off the | |
2498 | * request to the driver. | |
2499 | * | |
2500 | * Block internal functions which don't want to start timer should | |
2501 | * call blk_dequeue_request(). | |
2502 | * | |
2503 | * Context: | |
2504 | * queue_lock must be held. | |
2505 | */ | |
2506 | void blk_start_request(struct request *req) | |
2507 | { | |
2508 | blk_dequeue_request(req); | |
2509 | ||
cf43e6be | 2510 | if (test_bit(QUEUE_FLAG_STATS, &req->q->queue_flags)) { |
88eeca49 | 2511 | blk_stat_set_issue(&req->issue_stat, blk_rq_sectors(req)); |
cf43e6be | 2512 | req->rq_flags |= RQF_STATS; |
87760e5e | 2513 | wbt_issue(req->q->rq_wb, &req->issue_stat); |
cf43e6be JA |
2514 | } |
2515 | ||
4912aa6c | 2516 | BUG_ON(test_bit(REQ_ATOM_COMPLETE, &req->atomic_flags)); |
9934c8c0 TH |
2517 | blk_add_timer(req); |
2518 | } | |
2519 | EXPORT_SYMBOL(blk_start_request); | |
2520 | ||
2521 | /** | |
2522 | * blk_fetch_request - fetch a request from a request queue | |
2523 | * @q: request queue to fetch a request from | |
2524 | * | |
2525 | * Description: | |
2526 | * Return the request at the top of @q. The request is started on | |
2527 | * return and LLD can start processing it immediately. | |
2528 | * | |
2529 | * Return: | |
2530 | * Pointer to the request at the top of @q if available. Null | |
2531 | * otherwise. | |
2532 | * | |
2533 | * Context: | |
2534 | * queue_lock must be held. | |
2535 | */ | |
2536 | struct request *blk_fetch_request(struct request_queue *q) | |
2537 | { | |
2538 | struct request *rq; | |
2539 | ||
2540 | rq = blk_peek_request(q); | |
2541 | if (rq) | |
2542 | blk_start_request(rq); | |
2543 | return rq; | |
2544 | } | |
2545 | EXPORT_SYMBOL(blk_fetch_request); | |
2546 | ||
3bcddeac | 2547 | /** |
2e60e022 | 2548 | * blk_update_request - Special helper function for request stacking drivers |
8ebf9756 | 2549 | * @req: the request being processed |
710027a4 | 2550 | * @error: %0 for success, < %0 for error |
8ebf9756 | 2551 | * @nr_bytes: number of bytes to complete @req |
3bcddeac KU |
2552 | * |
2553 | * Description: | |
8ebf9756 RD |
2554 | * Ends I/O on a number of bytes attached to @req, but doesn't complete |
2555 | * the request structure even if @req doesn't have leftover. | |
2556 | * If @req has leftover, sets it up for the next range of segments. | |
2e60e022 TH |
2557 | * |
2558 | * This special helper function is only for request stacking drivers | |
2559 | * (e.g. request-based dm) so that they can handle partial completion. | |
2560 | * Actual device drivers should use blk_end_request instead. | |
2561 | * | |
2562 | * Passing the result of blk_rq_bytes() as @nr_bytes guarantees | |
2563 | * %false return from this function. | |
3bcddeac KU |
2564 | * |
2565 | * Return: | |
2e60e022 TH |
2566 | * %false - this request doesn't have any more data |
2567 | * %true - this request has more data | |
3bcddeac | 2568 | **/ |
2e60e022 | 2569 | bool blk_update_request(struct request *req, int error, unsigned int nr_bytes) |
1da177e4 | 2570 | { |
f79ea416 | 2571 | int total_bytes; |
1da177e4 | 2572 | |
caf7df12 | 2573 | trace_block_rq_complete(req, error, nr_bytes); |
4a0efdc9 | 2574 | |
2e60e022 TH |
2575 | if (!req->bio) |
2576 | return false; | |
2577 | ||
57292b58 | 2578 | if (error && !blk_rq_is_passthrough(req) && |
e8064021 | 2579 | !(req->rq_flags & RQF_QUIET)) { |
79775567 HR |
2580 | char *error_type; |
2581 | ||
2582 | switch (error) { | |
2583 | case -ENOLINK: | |
2584 | error_type = "recoverable transport"; | |
2585 | break; | |
2586 | case -EREMOTEIO: | |
2587 | error_type = "critical target"; | |
2588 | break; | |
2589 | case -EBADE: | |
2590 | error_type = "critical nexus"; | |
2591 | break; | |
d1ffc1f8 HR |
2592 | case -ETIMEDOUT: |
2593 | error_type = "timeout"; | |
2594 | break; | |
a9d6ceb8 HR |
2595 | case -ENOSPC: |
2596 | error_type = "critical space allocation"; | |
2597 | break; | |
7e782af5 HR |
2598 | case -ENODATA: |
2599 | error_type = "critical medium"; | |
2600 | break; | |
79775567 HR |
2601 | case -EIO: |
2602 | default: | |
2603 | error_type = "I/O"; | |
2604 | break; | |
2605 | } | |
ef3ecb66 RE |
2606 | printk_ratelimited(KERN_ERR "%s: %s error, dev %s, sector %llu\n", |
2607 | __func__, error_type, req->rq_disk ? | |
37d7b34f YZ |
2608 | req->rq_disk->disk_name : "?", |
2609 | (unsigned long long)blk_rq_pos(req)); | |
2610 | ||
1da177e4 LT |
2611 | } |
2612 | ||
bc58ba94 | 2613 | blk_account_io_completion(req, nr_bytes); |
d72d904a | 2614 | |
f79ea416 KO |
2615 | total_bytes = 0; |
2616 | while (req->bio) { | |
2617 | struct bio *bio = req->bio; | |
4f024f37 | 2618 | unsigned bio_bytes = min(bio->bi_iter.bi_size, nr_bytes); |
1da177e4 | 2619 | |
4f024f37 | 2620 | if (bio_bytes == bio->bi_iter.bi_size) |
1da177e4 | 2621 | req->bio = bio->bi_next; |
1da177e4 | 2622 | |
fbbaf700 N |
2623 | /* Completion has already been traced */ |
2624 | bio_clear_flag(bio, BIO_TRACE_COMPLETION); | |
f79ea416 | 2625 | req_bio_endio(req, bio, bio_bytes, error); |
1da177e4 | 2626 | |
f79ea416 KO |
2627 | total_bytes += bio_bytes; |
2628 | nr_bytes -= bio_bytes; | |
1da177e4 | 2629 | |
f79ea416 KO |
2630 | if (!nr_bytes) |
2631 | break; | |
1da177e4 LT |
2632 | } |
2633 | ||
2634 | /* | |
2635 | * completely done | |
2636 | */ | |
2e60e022 TH |
2637 | if (!req->bio) { |
2638 | /* | |
2639 | * Reset counters so that the request stacking driver | |
2640 | * can find how many bytes remain in the request | |
2641 | * later. | |
2642 | */ | |
a2dec7b3 | 2643 | req->__data_len = 0; |
2e60e022 TH |
2644 | return false; |
2645 | } | |
1da177e4 | 2646 | |
a2dec7b3 | 2647 | req->__data_len -= total_bytes; |
2e46e8b2 TH |
2648 | |
2649 | /* update sector only for requests with clear definition of sector */ | |
57292b58 | 2650 | if (!blk_rq_is_passthrough(req)) |
a2dec7b3 | 2651 | req->__sector += total_bytes >> 9; |
2e46e8b2 | 2652 | |
80a761fd | 2653 | /* mixed attributes always follow the first bio */ |
e8064021 | 2654 | if (req->rq_flags & RQF_MIXED_MERGE) { |
80a761fd | 2655 | req->cmd_flags &= ~REQ_FAILFAST_MASK; |
1eff9d32 | 2656 | req->cmd_flags |= req->bio->bi_opf & REQ_FAILFAST_MASK; |
80a761fd TH |
2657 | } |
2658 | ||
ed6565e7 CH |
2659 | if (!(req->rq_flags & RQF_SPECIAL_PAYLOAD)) { |
2660 | /* | |
2661 | * If total number of sectors is less than the first segment | |
2662 | * size, something has gone terribly wrong. | |
2663 | */ | |
2664 | if (blk_rq_bytes(req) < blk_rq_cur_bytes(req)) { | |
2665 | blk_dump_rq_flags(req, "request botched"); | |
2666 | req->__data_len = blk_rq_cur_bytes(req); | |
2667 | } | |
2e46e8b2 | 2668 | |
ed6565e7 CH |
2669 | /* recalculate the number of segments */ |
2670 | blk_recalc_rq_segments(req); | |
2671 | } | |
2e46e8b2 | 2672 | |
2e60e022 | 2673 | return true; |
1da177e4 | 2674 | } |
2e60e022 | 2675 | EXPORT_SYMBOL_GPL(blk_update_request); |
1da177e4 | 2676 | |
2e60e022 TH |
2677 | static bool blk_update_bidi_request(struct request *rq, int error, |
2678 | unsigned int nr_bytes, | |
2679 | unsigned int bidi_bytes) | |
5efccd17 | 2680 | { |
2e60e022 TH |
2681 | if (blk_update_request(rq, error, nr_bytes)) |
2682 | return true; | |
5efccd17 | 2683 | |
2e60e022 TH |
2684 | /* Bidi request must be completed as a whole */ |
2685 | if (unlikely(blk_bidi_rq(rq)) && | |
2686 | blk_update_request(rq->next_rq, error, bidi_bytes)) | |
2687 | return true; | |
5efccd17 | 2688 | |
e2e1a148 JA |
2689 | if (blk_queue_add_random(rq->q)) |
2690 | add_disk_randomness(rq->rq_disk); | |
2e60e022 TH |
2691 | |
2692 | return false; | |
1da177e4 LT |
2693 | } |
2694 | ||
28018c24 JB |
2695 | /** |
2696 | * blk_unprep_request - unprepare a request | |
2697 | * @req: the request | |
2698 | * | |
2699 | * This function makes a request ready for complete resubmission (or | |
2700 | * completion). It happens only after all error handling is complete, | |
2701 | * so represents the appropriate moment to deallocate any resources | |
2702 | * that were allocated to the request in the prep_rq_fn. The queue | |
2703 | * lock is held when calling this. | |
2704 | */ | |
2705 | void blk_unprep_request(struct request *req) | |
2706 | { | |
2707 | struct request_queue *q = req->q; | |
2708 | ||
e8064021 | 2709 | req->rq_flags &= ~RQF_DONTPREP; |
28018c24 JB |
2710 | if (q->unprep_rq_fn) |
2711 | q->unprep_rq_fn(q, req); | |
2712 | } | |
2713 | EXPORT_SYMBOL_GPL(blk_unprep_request); | |
2714 | ||
1da177e4 LT |
2715 | /* |
2716 | * queue lock must be held | |
2717 | */ | |
12120077 | 2718 | void blk_finish_request(struct request *req, int error) |
1da177e4 | 2719 | { |
cf43e6be JA |
2720 | struct request_queue *q = req->q; |
2721 | ||
2722 | if (req->rq_flags & RQF_STATS) | |
34dbad5d | 2723 | blk_stat_add(req); |
cf43e6be | 2724 | |
e8064021 | 2725 | if (req->rq_flags & RQF_QUEUED) |
cf43e6be | 2726 | blk_queue_end_tag(q, req); |
b8286239 | 2727 | |
ba396a6c | 2728 | BUG_ON(blk_queued_rq(req)); |
1da177e4 | 2729 | |
57292b58 | 2730 | if (unlikely(laptop_mode) && !blk_rq_is_passthrough(req)) |
dc3b17cc | 2731 | laptop_io_completion(req->q->backing_dev_info); |
1da177e4 | 2732 | |
e78042e5 MA |
2733 | blk_delete_timer(req); |
2734 | ||
e8064021 | 2735 | if (req->rq_flags & RQF_DONTPREP) |
28018c24 JB |
2736 | blk_unprep_request(req); |
2737 | ||
bc58ba94 | 2738 | blk_account_io_done(req); |
b8286239 | 2739 | |
87760e5e JA |
2740 | if (req->end_io) { |
2741 | wbt_done(req->q->rq_wb, &req->issue_stat); | |
8ffdc655 | 2742 | req->end_io(req, error); |
87760e5e | 2743 | } else { |
b8286239 KU |
2744 | if (blk_bidi_rq(req)) |
2745 | __blk_put_request(req->next_rq->q, req->next_rq); | |
2746 | ||
cf43e6be | 2747 | __blk_put_request(q, req); |
b8286239 | 2748 | } |
1da177e4 | 2749 | } |
12120077 | 2750 | EXPORT_SYMBOL(blk_finish_request); |
1da177e4 | 2751 | |
3b11313a | 2752 | /** |
2e60e022 TH |
2753 | * blk_end_bidi_request - Complete a bidi request |
2754 | * @rq: the request to complete | |
2755 | * @error: %0 for success, < %0 for error | |
2756 | * @nr_bytes: number of bytes to complete @rq | |
2757 | * @bidi_bytes: number of bytes to complete @rq->next_rq | |
a0cd1285 JA |
2758 | * |
2759 | * Description: | |
e3a04fe3 | 2760 | * Ends I/O on a number of bytes attached to @rq and @rq->next_rq. |
2e60e022 TH |
2761 | * Drivers that supports bidi can safely call this member for any |
2762 | * type of request, bidi or uni. In the later case @bidi_bytes is | |
2763 | * just ignored. | |
336cdb40 KU |
2764 | * |
2765 | * Return: | |
2e60e022 TH |
2766 | * %false - we are done with this request |
2767 | * %true - still buffers pending for this request | |
a0cd1285 | 2768 | **/ |
b1f74493 | 2769 | static bool blk_end_bidi_request(struct request *rq, int error, |
32fab448 KU |
2770 | unsigned int nr_bytes, unsigned int bidi_bytes) |
2771 | { | |
336cdb40 | 2772 | struct request_queue *q = rq->q; |
2e60e022 | 2773 | unsigned long flags; |
32fab448 | 2774 | |
2e60e022 TH |
2775 | if (blk_update_bidi_request(rq, error, nr_bytes, bidi_bytes)) |
2776 | return true; | |
32fab448 | 2777 | |
336cdb40 | 2778 | spin_lock_irqsave(q->queue_lock, flags); |
2e60e022 | 2779 | blk_finish_request(rq, error); |
336cdb40 KU |
2780 | spin_unlock_irqrestore(q->queue_lock, flags); |
2781 | ||
2e60e022 | 2782 | return false; |
32fab448 KU |
2783 | } |
2784 | ||
336cdb40 | 2785 | /** |
2e60e022 TH |
2786 | * __blk_end_bidi_request - Complete a bidi request with queue lock held |
2787 | * @rq: the request to complete | |
710027a4 | 2788 | * @error: %0 for success, < %0 for error |
e3a04fe3 KU |
2789 | * @nr_bytes: number of bytes to complete @rq |
2790 | * @bidi_bytes: number of bytes to complete @rq->next_rq | |
336cdb40 KU |
2791 | * |
2792 | * Description: | |
2e60e022 TH |
2793 | * Identical to blk_end_bidi_request() except that queue lock is |
2794 | * assumed to be locked on entry and remains so on return. | |
336cdb40 KU |
2795 | * |
2796 | * Return: | |
2e60e022 TH |
2797 | * %false - we are done with this request |
2798 | * %true - still buffers pending for this request | |
336cdb40 | 2799 | **/ |
d0fac025 | 2800 | static bool __blk_end_bidi_request(struct request *rq, int error, |
b1f74493 | 2801 | unsigned int nr_bytes, unsigned int bidi_bytes) |
336cdb40 | 2802 | { |
2e60e022 TH |
2803 | if (blk_update_bidi_request(rq, error, nr_bytes, bidi_bytes)) |
2804 | return true; | |
336cdb40 | 2805 | |
2e60e022 | 2806 | blk_finish_request(rq, error); |
336cdb40 | 2807 | |
2e60e022 | 2808 | return false; |
336cdb40 | 2809 | } |
e19a3ab0 KU |
2810 | |
2811 | /** | |
2812 | * blk_end_request - Helper function for drivers to complete the request. | |
2813 | * @rq: the request being processed | |
710027a4 | 2814 | * @error: %0 for success, < %0 for error |
e19a3ab0 KU |
2815 | * @nr_bytes: number of bytes to complete |
2816 | * | |
2817 | * Description: | |
2818 | * Ends I/O on a number of bytes attached to @rq. | |
2819 | * If @rq has leftover, sets it up for the next range of segments. | |
2820 | * | |
2821 | * Return: | |
b1f74493 FT |
2822 | * %false - we are done with this request |
2823 | * %true - still buffers pending for this request | |
e19a3ab0 | 2824 | **/ |
b1f74493 | 2825 | bool blk_end_request(struct request *rq, int error, unsigned int nr_bytes) |
e19a3ab0 | 2826 | { |
b1f74493 | 2827 | return blk_end_bidi_request(rq, error, nr_bytes, 0); |
e19a3ab0 | 2828 | } |
56ad1740 | 2829 | EXPORT_SYMBOL(blk_end_request); |
336cdb40 KU |
2830 | |
2831 | /** | |
b1f74493 FT |
2832 | * blk_end_request_all - Helper function for drives to finish the request. |
2833 | * @rq: the request to finish | |
8ebf9756 | 2834 | * @error: %0 for success, < %0 for error |
336cdb40 KU |
2835 | * |
2836 | * Description: | |
b1f74493 FT |
2837 | * Completely finish @rq. |
2838 | */ | |
2839 | void blk_end_request_all(struct request *rq, int error) | |
336cdb40 | 2840 | { |
b1f74493 FT |
2841 | bool pending; |
2842 | unsigned int bidi_bytes = 0; | |
336cdb40 | 2843 | |
b1f74493 FT |
2844 | if (unlikely(blk_bidi_rq(rq))) |
2845 | bidi_bytes = blk_rq_bytes(rq->next_rq); | |
336cdb40 | 2846 | |
b1f74493 FT |
2847 | pending = blk_end_bidi_request(rq, error, blk_rq_bytes(rq), bidi_bytes); |
2848 | BUG_ON(pending); | |
2849 | } | |
56ad1740 | 2850 | EXPORT_SYMBOL(blk_end_request_all); |
336cdb40 | 2851 | |
e3a04fe3 | 2852 | /** |
b1f74493 FT |
2853 | * __blk_end_request - Helper function for drivers to complete the request. |
2854 | * @rq: the request being processed | |
2855 | * @error: %0 for success, < %0 for error | |
2856 | * @nr_bytes: number of bytes to complete | |
e3a04fe3 KU |
2857 | * |
2858 | * Description: | |
b1f74493 | 2859 | * Must be called with queue lock held unlike blk_end_request(). |
e3a04fe3 KU |
2860 | * |
2861 | * Return: | |
b1f74493 FT |
2862 | * %false - we are done with this request |
2863 | * %true - still buffers pending for this request | |
e3a04fe3 | 2864 | **/ |
b1f74493 | 2865 | bool __blk_end_request(struct request *rq, int error, unsigned int nr_bytes) |
e3a04fe3 | 2866 | { |
b1f74493 | 2867 | return __blk_end_bidi_request(rq, error, nr_bytes, 0); |
e3a04fe3 | 2868 | } |
56ad1740 | 2869 | EXPORT_SYMBOL(__blk_end_request); |
e3a04fe3 | 2870 | |
32fab448 | 2871 | /** |
b1f74493 FT |
2872 | * __blk_end_request_all - Helper function for drives to finish the request. |
2873 | * @rq: the request to finish | |
8ebf9756 | 2874 | * @error: %0 for success, < %0 for error |
32fab448 KU |
2875 | * |
2876 | * Description: | |
b1f74493 | 2877 | * Completely finish @rq. Must be called with queue lock held. |
32fab448 | 2878 | */ |
b1f74493 | 2879 | void __blk_end_request_all(struct request *rq, int error) |
32fab448 | 2880 | { |
b1f74493 FT |
2881 | bool pending; |
2882 | unsigned int bidi_bytes = 0; | |
2883 | ||
2884 | if (unlikely(blk_bidi_rq(rq))) | |
2885 | bidi_bytes = blk_rq_bytes(rq->next_rq); | |
2886 | ||
2887 | pending = __blk_end_bidi_request(rq, error, blk_rq_bytes(rq), bidi_bytes); | |
2888 | BUG_ON(pending); | |
32fab448 | 2889 | } |
56ad1740 | 2890 | EXPORT_SYMBOL(__blk_end_request_all); |
32fab448 | 2891 | |
e19a3ab0 | 2892 | /** |
b1f74493 FT |
2893 | * __blk_end_request_cur - Helper function to finish the current request chunk. |
2894 | * @rq: the request to finish the current chunk for | |
8ebf9756 | 2895 | * @error: %0 for success, < %0 for error |
e19a3ab0 KU |
2896 | * |
2897 | * Description: | |
b1f74493 FT |
2898 | * Complete the current consecutively mapped chunk from @rq. Must |
2899 | * be called with queue lock held. | |
e19a3ab0 KU |
2900 | * |
2901 | * Return: | |
b1f74493 FT |
2902 | * %false - we are done with this request |
2903 | * %true - still buffers pending for this request | |
2904 | */ | |
2905 | bool __blk_end_request_cur(struct request *rq, int error) | |
e19a3ab0 | 2906 | { |
b1f74493 | 2907 | return __blk_end_request(rq, error, blk_rq_cur_bytes(rq)); |
e19a3ab0 | 2908 | } |
56ad1740 | 2909 | EXPORT_SYMBOL(__blk_end_request_cur); |
e19a3ab0 | 2910 | |
86db1e29 JA |
2911 | void blk_rq_bio_prep(struct request_queue *q, struct request *rq, |
2912 | struct bio *bio) | |
1da177e4 | 2913 | { |
b4f42e28 | 2914 | if (bio_has_data(bio)) |
fb2dce86 | 2915 | rq->nr_phys_segments = bio_phys_segments(q, bio); |
b4f42e28 | 2916 | |
4f024f37 | 2917 | rq->__data_len = bio->bi_iter.bi_size; |
1da177e4 | 2918 | rq->bio = rq->biotail = bio; |
1da177e4 | 2919 | |
66846572 N |
2920 | if (bio->bi_bdev) |
2921 | rq->rq_disk = bio->bi_bdev->bd_disk; | |
2922 | } | |
1da177e4 | 2923 | |
2d4dc890 IL |
2924 | #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE |
2925 | /** | |
2926 | * rq_flush_dcache_pages - Helper function to flush all pages in a request | |
2927 | * @rq: the request to be flushed | |
2928 | * | |
2929 | * Description: | |
2930 | * Flush all pages in @rq. | |
2931 | */ | |
2932 | void rq_flush_dcache_pages(struct request *rq) | |
2933 | { | |
2934 | struct req_iterator iter; | |
7988613b | 2935 | struct bio_vec bvec; |
2d4dc890 IL |
2936 | |
2937 | rq_for_each_segment(bvec, rq, iter) | |
7988613b | 2938 | flush_dcache_page(bvec.bv_page); |
2d4dc890 IL |
2939 | } |
2940 | EXPORT_SYMBOL_GPL(rq_flush_dcache_pages); | |
2941 | #endif | |
2942 | ||
ef9e3fac KU |
2943 | /** |
2944 | * blk_lld_busy - Check if underlying low-level drivers of a device are busy | |
2945 | * @q : the queue of the device being checked | |
2946 | * | |
2947 | * Description: | |
2948 | * Check if underlying low-level drivers of a device are busy. | |
2949 | * If the drivers want to export their busy state, they must set own | |
2950 | * exporting function using blk_queue_lld_busy() first. | |
2951 | * | |
2952 | * Basically, this function is used only by request stacking drivers | |
2953 | * to stop dispatching requests to underlying devices when underlying | |
2954 | * devices are busy. This behavior helps more I/O merging on the queue | |
2955 | * of the request stacking driver and prevents I/O throughput regression | |
2956 | * on burst I/O load. | |
2957 | * | |
2958 | * Return: | |
2959 | * 0 - Not busy (The request stacking driver should dispatch request) | |
2960 | * 1 - Busy (The request stacking driver should stop dispatching request) | |
2961 | */ | |
2962 | int blk_lld_busy(struct request_queue *q) | |
2963 | { | |
2964 | if (q->lld_busy_fn) | |
2965 | return q->lld_busy_fn(q); | |
2966 | ||
2967 | return 0; | |
2968 | } | |
2969 | EXPORT_SYMBOL_GPL(blk_lld_busy); | |
2970 | ||
78d8e58a MS |
2971 | /** |
2972 | * blk_rq_unprep_clone - Helper function to free all bios in a cloned request | |
2973 | * @rq: the clone request to be cleaned up | |
2974 | * | |
2975 | * Description: | |
2976 | * Free all bios in @rq for a cloned request. | |
2977 | */ | |
2978 | void blk_rq_unprep_clone(struct request *rq) | |
2979 | { | |
2980 | struct bio *bio; | |
2981 | ||
2982 | while ((bio = rq->bio) != NULL) { | |
2983 | rq->bio = bio->bi_next; | |
2984 | ||
2985 | bio_put(bio); | |
2986 | } | |
2987 | } | |
2988 | EXPORT_SYMBOL_GPL(blk_rq_unprep_clone); | |
2989 | ||
2990 | /* | |
2991 | * Copy attributes of the original request to the clone request. | |
2992 | * The actual data parts (e.g. ->cmd, ->sense) are not copied. | |
2993 | */ | |
2994 | static void __blk_rq_prep_clone(struct request *dst, struct request *src) | |
b0fd271d KU |
2995 | { |
2996 | dst->cpu = src->cpu; | |
b0fd271d KU |
2997 | dst->__sector = blk_rq_pos(src); |
2998 | dst->__data_len = blk_rq_bytes(src); | |
2999 | dst->nr_phys_segments = src->nr_phys_segments; | |
3000 | dst->ioprio = src->ioprio; | |
3001 | dst->extra_len = src->extra_len; | |
78d8e58a MS |
3002 | } |
3003 | ||
3004 | /** | |
3005 | * blk_rq_prep_clone - Helper function to setup clone request | |
3006 | * @rq: the request to be setup | |
3007 | * @rq_src: original request to be cloned | |
3008 | * @bs: bio_set that bios for clone are allocated from | |
3009 | * @gfp_mask: memory allocation mask for bio | |
3010 | * @bio_ctr: setup function to be called for each clone bio. | |
3011 | * Returns %0 for success, non %0 for failure. | |
3012 | * @data: private data to be passed to @bio_ctr | |
3013 | * | |
3014 | * Description: | |
3015 | * Clones bios in @rq_src to @rq, and copies attributes of @rq_src to @rq. | |
3016 | * The actual data parts of @rq_src (e.g. ->cmd, ->sense) | |
3017 | * are not copied, and copying such parts is the caller's responsibility. | |
3018 | * Also, pages which the original bios are pointing to are not copied | |
3019 | * and the cloned bios just point same pages. | |
3020 | * So cloned bios must be completed before original bios, which means | |
3021 | * the caller must complete @rq before @rq_src. | |
3022 | */ | |
3023 | int blk_rq_prep_clone(struct request *rq, struct request *rq_src, | |
3024 | struct bio_set *bs, gfp_t gfp_mask, | |
3025 | int (*bio_ctr)(struct bio *, struct bio *, void *), | |
3026 | void *data) | |
3027 | { | |
3028 | struct bio *bio, *bio_src; | |
3029 | ||
3030 | if (!bs) | |
3031 | bs = fs_bio_set; | |
3032 | ||
3033 | __rq_for_each_bio(bio_src, rq_src) { | |
3034 | bio = bio_clone_fast(bio_src, gfp_mask, bs); | |
3035 | if (!bio) | |
3036 | goto free_and_out; | |
3037 | ||
3038 | if (bio_ctr && bio_ctr(bio, bio_src, data)) | |
3039 | goto free_and_out; | |
3040 | ||
3041 | if (rq->bio) { | |
3042 | rq->biotail->bi_next = bio; | |
3043 | rq->biotail = bio; | |
3044 | } else | |
3045 | rq->bio = rq->biotail = bio; | |
3046 | } | |
3047 | ||
3048 | __blk_rq_prep_clone(rq, rq_src); | |
3049 | ||
3050 | return 0; | |
3051 | ||
3052 | free_and_out: | |
3053 | if (bio) | |
3054 | bio_put(bio); | |
3055 | blk_rq_unprep_clone(rq); | |
3056 | ||
3057 | return -ENOMEM; | |
b0fd271d KU |
3058 | } |
3059 | EXPORT_SYMBOL_GPL(blk_rq_prep_clone); | |
3060 | ||
59c3d45e | 3061 | int kblockd_schedule_work(struct work_struct *work) |
1da177e4 LT |
3062 | { |
3063 | return queue_work(kblockd_workqueue, work); | |
3064 | } | |
1da177e4 LT |
3065 | EXPORT_SYMBOL(kblockd_schedule_work); |
3066 | ||
ee63cfa7 JA |
3067 | int kblockd_schedule_work_on(int cpu, struct work_struct *work) |
3068 | { | |
3069 | return queue_work_on(cpu, kblockd_workqueue, work); | |
3070 | } | |
3071 | EXPORT_SYMBOL(kblockd_schedule_work_on); | |
3072 | ||
818cd1cb JA |
3073 | int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork, |
3074 | unsigned long delay) | |
3075 | { | |
3076 | return mod_delayed_work_on(cpu, kblockd_workqueue, dwork, delay); | |
3077 | } | |
3078 | EXPORT_SYMBOL(kblockd_mod_delayed_work_on); | |
3079 | ||
59c3d45e JA |
3080 | int kblockd_schedule_delayed_work(struct delayed_work *dwork, |
3081 | unsigned long delay) | |
e43473b7 VG |
3082 | { |
3083 | return queue_delayed_work(kblockd_workqueue, dwork, delay); | |
3084 | } | |
3085 | EXPORT_SYMBOL(kblockd_schedule_delayed_work); | |
3086 | ||
8ab14595 JA |
3087 | int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, |
3088 | unsigned long delay) | |
3089 | { | |
3090 | return queue_delayed_work_on(cpu, kblockd_workqueue, dwork, delay); | |
3091 | } | |
3092 | EXPORT_SYMBOL(kblockd_schedule_delayed_work_on); | |
3093 | ||
75df7136 SJ |
3094 | /** |
3095 | * blk_start_plug - initialize blk_plug and track it inside the task_struct | |
3096 | * @plug: The &struct blk_plug that needs to be initialized | |
3097 | * | |
3098 | * Description: | |
3099 | * Tracking blk_plug inside the task_struct will help with auto-flushing the | |
3100 | * pending I/O should the task end up blocking between blk_start_plug() and | |
3101 | * blk_finish_plug(). This is important from a performance perspective, but | |
3102 | * also ensures that we don't deadlock. For instance, if the task is blocking | |
3103 | * for a memory allocation, memory reclaim could end up wanting to free a | |
3104 | * page belonging to that request that is currently residing in our private | |
3105 | * plug. By flushing the pending I/O when the process goes to sleep, we avoid | |
3106 | * this kind of deadlock. | |
3107 | */ | |
73c10101 JA |
3108 | void blk_start_plug(struct blk_plug *plug) |
3109 | { | |
3110 | struct task_struct *tsk = current; | |
3111 | ||
dd6cf3e1 SL |
3112 | /* |
3113 | * If this is a nested plug, don't actually assign it. | |
3114 | */ | |
3115 | if (tsk->plug) | |
3116 | return; | |
3117 | ||
73c10101 | 3118 | INIT_LIST_HEAD(&plug->list); |
320ae51f | 3119 | INIT_LIST_HEAD(&plug->mq_list); |
048c9374 | 3120 | INIT_LIST_HEAD(&plug->cb_list); |
73c10101 | 3121 | /* |
dd6cf3e1 SL |
3122 | * Store ordering should not be needed here, since a potential |
3123 | * preempt will imply a full memory barrier | |
73c10101 | 3124 | */ |
dd6cf3e1 | 3125 | tsk->plug = plug; |
73c10101 JA |
3126 | } |
3127 | EXPORT_SYMBOL(blk_start_plug); | |
3128 | ||
3129 | static int plug_rq_cmp(void *priv, struct list_head *a, struct list_head *b) | |
3130 | { | |
3131 | struct request *rqa = container_of(a, struct request, queuelist); | |
3132 | struct request *rqb = container_of(b, struct request, queuelist); | |
3133 | ||
975927b9 JM |
3134 | return !(rqa->q < rqb->q || |
3135 | (rqa->q == rqb->q && blk_rq_pos(rqa) < blk_rq_pos(rqb))); | |
73c10101 JA |
3136 | } |
3137 | ||
49cac01e JA |
3138 | /* |
3139 | * If 'from_schedule' is true, then postpone the dispatch of requests | |
3140 | * until a safe kblockd context. We due this to avoid accidental big | |
3141 | * additional stack usage in driver dispatch, in places where the originally | |
3142 | * plugger did not intend it. | |
3143 | */ | |
f6603783 | 3144 | static void queue_unplugged(struct request_queue *q, unsigned int depth, |
49cac01e | 3145 | bool from_schedule) |
99e22598 | 3146 | __releases(q->queue_lock) |
94b5eb28 | 3147 | { |
49cac01e | 3148 | trace_block_unplug(q, depth, !from_schedule); |
99e22598 | 3149 | |
70460571 | 3150 | if (from_schedule) |
24ecfbe2 | 3151 | blk_run_queue_async(q); |
70460571 | 3152 | else |
24ecfbe2 | 3153 | __blk_run_queue(q); |
70460571 | 3154 | spin_unlock(q->queue_lock); |
94b5eb28 JA |
3155 | } |
3156 | ||
74018dc3 | 3157 | static void flush_plug_callbacks(struct blk_plug *plug, bool from_schedule) |
048c9374 N |
3158 | { |
3159 | LIST_HEAD(callbacks); | |
3160 | ||
2a7d5559 SL |
3161 | while (!list_empty(&plug->cb_list)) { |
3162 | list_splice_init(&plug->cb_list, &callbacks); | |
048c9374 | 3163 | |
2a7d5559 SL |
3164 | while (!list_empty(&callbacks)) { |
3165 | struct blk_plug_cb *cb = list_first_entry(&callbacks, | |
048c9374 N |
3166 | struct blk_plug_cb, |
3167 | list); | |
2a7d5559 | 3168 | list_del(&cb->list); |
74018dc3 | 3169 | cb->callback(cb, from_schedule); |
2a7d5559 | 3170 | } |
048c9374 N |
3171 | } |
3172 | } | |
3173 | ||
9cbb1750 N |
3174 | struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, void *data, |
3175 | int size) | |
3176 | { | |
3177 | struct blk_plug *plug = current->plug; | |
3178 | struct blk_plug_cb *cb; | |
3179 | ||
3180 | if (!plug) | |
3181 | return NULL; | |
3182 | ||
3183 | list_for_each_entry(cb, &plug->cb_list, list) | |
3184 | if (cb->callback == unplug && cb->data == data) | |
3185 | return cb; | |
3186 | ||
3187 | /* Not currently on the callback list */ | |
3188 | BUG_ON(size < sizeof(*cb)); | |
3189 | cb = kzalloc(size, GFP_ATOMIC); | |
3190 | if (cb) { | |
3191 | cb->data = data; | |
3192 | cb->callback = unplug; | |
3193 | list_add(&cb->list, &plug->cb_list); | |
3194 | } | |
3195 | return cb; | |
3196 | } | |
3197 | EXPORT_SYMBOL(blk_check_plugged); | |
3198 | ||
49cac01e | 3199 | void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule) |
73c10101 JA |
3200 | { |
3201 | struct request_queue *q; | |
3202 | unsigned long flags; | |
3203 | struct request *rq; | |
109b8129 | 3204 | LIST_HEAD(list); |
94b5eb28 | 3205 | unsigned int depth; |
73c10101 | 3206 | |
74018dc3 | 3207 | flush_plug_callbacks(plug, from_schedule); |
320ae51f JA |
3208 | |
3209 | if (!list_empty(&plug->mq_list)) | |
3210 | blk_mq_flush_plug_list(plug, from_schedule); | |
3211 | ||
73c10101 JA |
3212 | if (list_empty(&plug->list)) |
3213 | return; | |
3214 | ||
109b8129 N |
3215 | list_splice_init(&plug->list, &list); |
3216 | ||
422765c2 | 3217 | list_sort(NULL, &list, plug_rq_cmp); |
73c10101 JA |
3218 | |
3219 | q = NULL; | |
94b5eb28 | 3220 | depth = 0; |
18811272 JA |
3221 | |
3222 | /* | |
3223 | * Save and disable interrupts here, to avoid doing it for every | |
3224 | * queue lock we have to take. | |
3225 | */ | |
73c10101 | 3226 | local_irq_save(flags); |
109b8129 N |
3227 | while (!list_empty(&list)) { |
3228 | rq = list_entry_rq(list.next); | |
73c10101 | 3229 | list_del_init(&rq->queuelist); |
73c10101 JA |
3230 | BUG_ON(!rq->q); |
3231 | if (rq->q != q) { | |
99e22598 JA |
3232 | /* |
3233 | * This drops the queue lock | |
3234 | */ | |
3235 | if (q) | |
49cac01e | 3236 | queue_unplugged(q, depth, from_schedule); |
73c10101 | 3237 | q = rq->q; |
94b5eb28 | 3238 | depth = 0; |
73c10101 JA |
3239 | spin_lock(q->queue_lock); |
3240 | } | |
8ba61435 TH |
3241 | |
3242 | /* | |
3243 | * Short-circuit if @q is dead | |
3244 | */ | |
3f3299d5 | 3245 | if (unlikely(blk_queue_dying(q))) { |
8ba61435 TH |
3246 | __blk_end_request_all(rq, -ENODEV); |
3247 | continue; | |
3248 | } | |
3249 | ||
73c10101 JA |
3250 | /* |
3251 | * rq is already accounted, so use raw insert | |
3252 | */ | |
f73f44eb | 3253 | if (op_is_flush(rq->cmd_flags)) |
401a18e9 JA |
3254 | __elv_add_request(q, rq, ELEVATOR_INSERT_FLUSH); |
3255 | else | |
3256 | __elv_add_request(q, rq, ELEVATOR_INSERT_SORT_MERGE); | |
94b5eb28 JA |
3257 | |
3258 | depth++; | |
73c10101 JA |
3259 | } |
3260 | ||
99e22598 JA |
3261 | /* |
3262 | * This drops the queue lock | |
3263 | */ | |
3264 | if (q) | |
49cac01e | 3265 | queue_unplugged(q, depth, from_schedule); |
73c10101 | 3266 | |
73c10101 JA |
3267 | local_irq_restore(flags); |
3268 | } | |
73c10101 JA |
3269 | |
3270 | void blk_finish_plug(struct blk_plug *plug) | |
3271 | { | |
dd6cf3e1 SL |
3272 | if (plug != current->plug) |
3273 | return; | |
f6603783 | 3274 | blk_flush_plug_list(plug, false); |
73c10101 | 3275 | |
dd6cf3e1 | 3276 | current->plug = NULL; |
73c10101 | 3277 | } |
88b996cd | 3278 | EXPORT_SYMBOL(blk_finish_plug); |
73c10101 | 3279 | |
47fafbc7 | 3280 | #ifdef CONFIG_PM |
6c954667 LM |
3281 | /** |
3282 | * blk_pm_runtime_init - Block layer runtime PM initialization routine | |
3283 | * @q: the queue of the device | |
3284 | * @dev: the device the queue belongs to | |
3285 | * | |
3286 | * Description: | |
3287 | * Initialize runtime-PM-related fields for @q and start auto suspend for | |
3288 | * @dev. Drivers that want to take advantage of request-based runtime PM | |
3289 | * should call this function after @dev has been initialized, and its | |
3290 | * request queue @q has been allocated, and runtime PM for it can not happen | |
3291 | * yet(either due to disabled/forbidden or its usage_count > 0). In most | |
3292 | * cases, driver should call this function before any I/O has taken place. | |
3293 | * | |
3294 | * This function takes care of setting up using auto suspend for the device, | |
3295 | * the autosuspend delay is set to -1 to make runtime suspend impossible | |
3296 | * until an updated value is either set by user or by driver. Drivers do | |
3297 | * not need to touch other autosuspend settings. | |
3298 | * | |
3299 | * The block layer runtime PM is request based, so only works for drivers | |
3300 | * that use request as their IO unit instead of those directly use bio's. | |
3301 | */ | |
3302 | void blk_pm_runtime_init(struct request_queue *q, struct device *dev) | |
3303 | { | |
3304 | q->dev = dev; | |
3305 | q->rpm_status = RPM_ACTIVE; | |
3306 | pm_runtime_set_autosuspend_delay(q->dev, -1); | |
3307 | pm_runtime_use_autosuspend(q->dev); | |
3308 | } | |
3309 | EXPORT_SYMBOL(blk_pm_runtime_init); | |
3310 | ||
3311 | /** | |
3312 | * blk_pre_runtime_suspend - Pre runtime suspend check | |
3313 | * @q: the queue of the device | |
3314 | * | |
3315 | * Description: | |
3316 | * This function will check if runtime suspend is allowed for the device | |
3317 | * by examining if there are any requests pending in the queue. If there | |
3318 | * are requests pending, the device can not be runtime suspended; otherwise, | |
3319 | * the queue's status will be updated to SUSPENDING and the driver can | |
3320 | * proceed to suspend the device. | |
3321 | * | |
3322 | * For the not allowed case, we mark last busy for the device so that | |
3323 | * runtime PM core will try to autosuspend it some time later. | |
3324 | * | |
3325 | * This function should be called near the start of the device's | |
3326 | * runtime_suspend callback. | |
3327 | * | |
3328 | * Return: | |
3329 | * 0 - OK to runtime suspend the device | |
3330 | * -EBUSY - Device should not be runtime suspended | |
3331 | */ | |
3332 | int blk_pre_runtime_suspend(struct request_queue *q) | |
3333 | { | |
3334 | int ret = 0; | |
3335 | ||
4fd41a85 KX |
3336 | if (!q->dev) |
3337 | return ret; | |
3338 | ||
6c954667 LM |
3339 | spin_lock_irq(q->queue_lock); |
3340 | if (q->nr_pending) { | |
3341 | ret = -EBUSY; | |
3342 | pm_runtime_mark_last_busy(q->dev); | |
3343 | } else { | |
3344 | q->rpm_status = RPM_SUSPENDING; | |
3345 | } | |
3346 | spin_unlock_irq(q->queue_lock); | |
3347 | return ret; | |
3348 | } | |
3349 | EXPORT_SYMBOL(blk_pre_runtime_suspend); | |
3350 | ||
3351 | /** | |
3352 | * blk_post_runtime_suspend - Post runtime suspend processing | |
3353 | * @q: the queue of the device | |
3354 | * @err: return value of the device's runtime_suspend function | |
3355 | * | |
3356 | * Description: | |
3357 | * Update the queue's runtime status according to the return value of the | |
3358 | * device's runtime suspend function and mark last busy for the device so | |
3359 | * that PM core will try to auto suspend the device at a later time. | |
3360 | * | |
3361 | * This function should be called near the end of the device's | |
3362 | * runtime_suspend callback. | |
3363 | */ | |
3364 | void blk_post_runtime_suspend(struct request_queue *q, int err) | |
3365 | { | |
4fd41a85 KX |
3366 | if (!q->dev) |
3367 | return; | |
3368 | ||
6c954667 LM |
3369 | spin_lock_irq(q->queue_lock); |
3370 | if (!err) { | |
3371 | q->rpm_status = RPM_SUSPENDED; | |
3372 | } else { | |
3373 | q->rpm_status = RPM_ACTIVE; | |
3374 | pm_runtime_mark_last_busy(q->dev); | |
3375 | } | |
3376 | spin_unlock_irq(q->queue_lock); | |
3377 | } | |
3378 | EXPORT_SYMBOL(blk_post_runtime_suspend); | |
3379 | ||
3380 | /** | |
3381 | * blk_pre_runtime_resume - Pre runtime resume processing | |
3382 | * @q: the queue of the device | |
3383 | * | |
3384 | * Description: | |
3385 | * Update the queue's runtime status to RESUMING in preparation for the | |
3386 | * runtime resume of the device. | |
3387 | * | |
3388 | * This function should be called near the start of the device's | |
3389 | * runtime_resume callback. | |
3390 | */ | |
3391 | void blk_pre_runtime_resume(struct request_queue *q) | |
3392 | { | |
4fd41a85 KX |
3393 | if (!q->dev) |
3394 | return; | |
3395 | ||
6c954667 LM |
3396 | spin_lock_irq(q->queue_lock); |
3397 | q->rpm_status = RPM_RESUMING; | |
3398 | spin_unlock_irq(q->queue_lock); | |
3399 | } | |
3400 | EXPORT_SYMBOL(blk_pre_runtime_resume); | |
3401 | ||
3402 | /** | |
3403 | * blk_post_runtime_resume - Post runtime resume processing | |
3404 | * @q: the queue of the device | |
3405 | * @err: return value of the device's runtime_resume function | |
3406 | * | |
3407 | * Description: | |
3408 | * Update the queue's runtime status according to the return value of the | |
3409 | * device's runtime_resume function. If it is successfully resumed, process | |
3410 | * the requests that are queued into the device's queue when it is resuming | |
3411 | * and then mark last busy and initiate autosuspend for it. | |
3412 | * | |
3413 | * This function should be called near the end of the device's | |
3414 | * runtime_resume callback. | |
3415 | */ | |
3416 | void blk_post_runtime_resume(struct request_queue *q, int err) | |
3417 | { | |
4fd41a85 KX |
3418 | if (!q->dev) |
3419 | return; | |
3420 | ||
6c954667 LM |
3421 | spin_lock_irq(q->queue_lock); |
3422 | if (!err) { | |
3423 | q->rpm_status = RPM_ACTIVE; | |
3424 | __blk_run_queue(q); | |
3425 | pm_runtime_mark_last_busy(q->dev); | |
c60855cd | 3426 | pm_request_autosuspend(q->dev); |
6c954667 LM |
3427 | } else { |
3428 | q->rpm_status = RPM_SUSPENDED; | |
3429 | } | |
3430 | spin_unlock_irq(q->queue_lock); | |
3431 | } | |
3432 | EXPORT_SYMBOL(blk_post_runtime_resume); | |
d07ab6d1 MW |
3433 | |
3434 | /** | |
3435 | * blk_set_runtime_active - Force runtime status of the queue to be active | |
3436 | * @q: the queue of the device | |
3437 | * | |
3438 | * If the device is left runtime suspended during system suspend the resume | |
3439 | * hook typically resumes the device and corrects runtime status | |
3440 | * accordingly. However, that does not affect the queue runtime PM status | |
3441 | * which is still "suspended". This prevents processing requests from the | |
3442 | * queue. | |
3443 | * | |
3444 | * This function can be used in driver's resume hook to correct queue | |
3445 | * runtime PM status and re-enable peeking requests from the queue. It | |
3446 | * should be called before first request is added to the queue. | |
3447 | */ | |
3448 | void blk_set_runtime_active(struct request_queue *q) | |
3449 | { | |
3450 | spin_lock_irq(q->queue_lock); | |
3451 | q->rpm_status = RPM_ACTIVE; | |
3452 | pm_runtime_mark_last_busy(q->dev); | |
3453 | pm_request_autosuspend(q->dev); | |
3454 | spin_unlock_irq(q->queue_lock); | |
3455 | } | |
3456 | EXPORT_SYMBOL(blk_set_runtime_active); | |
6c954667 LM |
3457 | #endif |
3458 | ||
1da177e4 LT |
3459 | int __init blk_dev_init(void) |
3460 | { | |
ef295ecf CH |
3461 | BUILD_BUG_ON(REQ_OP_LAST >= (1 << REQ_OP_BITS)); |
3462 | BUILD_BUG_ON(REQ_OP_BITS + REQ_FLAG_BITS > 8 * | |
0762b23d | 3463 | FIELD_SIZEOF(struct request, cmd_flags)); |
ef295ecf CH |
3464 | BUILD_BUG_ON(REQ_OP_BITS + REQ_FLAG_BITS > 8 * |
3465 | FIELD_SIZEOF(struct bio, bi_opf)); | |
9eb55b03 | 3466 | |
89b90be2 TH |
3467 | /* used for unplugging and affects IO latency/throughput - HIGHPRI */ |
3468 | kblockd_workqueue = alloc_workqueue("kblockd", | |
28747fcd | 3469 | WQ_MEM_RECLAIM | WQ_HIGHPRI, 0); |
1da177e4 LT |
3470 | if (!kblockd_workqueue) |
3471 | panic("Failed to create kblockd\n"); | |
3472 | ||
3473 | request_cachep = kmem_cache_create("blkdev_requests", | |
20c2df83 | 3474 | sizeof(struct request), 0, SLAB_PANIC, NULL); |
1da177e4 | 3475 | |
c2789bd4 | 3476 | blk_requestq_cachep = kmem_cache_create("request_queue", |
165125e1 | 3477 | sizeof(struct request_queue), 0, SLAB_PANIC, NULL); |
1da177e4 | 3478 | |
18fbda91 OS |
3479 | #ifdef CONFIG_DEBUG_FS |
3480 | blk_debugfs_root = debugfs_create_dir("block", NULL); | |
3481 | #endif | |
3482 | ||
d38ecf93 | 3483 | return 0; |
1da177e4 | 3484 | } |