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3dcf60bc | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 | 2 | /* |
1da177e4 LT |
3 | * Copyright (C) 1991, 1992 Linus Torvalds |
4 | * Copyright (C) 1994, Karl Keyte: Added support for disk statistics | |
5 | * Elevator latency, (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE | |
6 | * Queue request tables / lock, selectable elevator, Jens Axboe <axboe@suse.de> | |
6728cb0e JA |
7 | * kernel-doc documentation started by NeilBrown <neilb@cse.unsw.edu.au> |
8 | * - July2000 | |
1da177e4 LT |
9 | * bio rewrite, highmem i/o, etc, Jens Axboe <axboe@suse.de> - may 2001 |
10 | */ | |
11 | ||
12 | /* | |
13 | * This handles all read/write requests to block devices | |
14 | */ | |
1da177e4 LT |
15 | #include <linux/kernel.h> |
16 | #include <linux/module.h> | |
17 | #include <linux/backing-dev.h> | |
18 | #include <linux/bio.h> | |
19 | #include <linux/blkdev.h> | |
320ae51f | 20 | #include <linux/blk-mq.h> |
1da177e4 LT |
21 | #include <linux/highmem.h> |
22 | #include <linux/mm.h> | |
cee9a0c4 | 23 | #include <linux/pagemap.h> |
1da177e4 LT |
24 | #include <linux/kernel_stat.h> |
25 | #include <linux/string.h> | |
26 | #include <linux/init.h> | |
1da177e4 LT |
27 | #include <linux/completion.h> |
28 | #include <linux/slab.h> | |
29 | #include <linux/swap.h> | |
30 | #include <linux/writeback.h> | |
faccbd4b | 31 | #include <linux/task_io_accounting_ops.h> |
c17bb495 | 32 | #include <linux/fault-inject.h> |
73c10101 | 33 | #include <linux/list_sort.h> |
e3c78ca5 | 34 | #include <linux/delay.h> |
aaf7c680 | 35 | #include <linux/ratelimit.h> |
6c954667 | 36 | #include <linux/pm_runtime.h> |
eea8f41c | 37 | #include <linux/blk-cgroup.h> |
54d4e6ab | 38 | #include <linux/t10-pi.h> |
18fbda91 | 39 | #include <linux/debugfs.h> |
30abb3a6 | 40 | #include <linux/bpf.h> |
b8e24a93 | 41 | #include <linux/psi.h> |
71ac860a | 42 | #include <linux/sched/sysctl.h> |
a892c8d5 | 43 | #include <linux/blk-crypto.h> |
55782138 LZ |
44 | |
45 | #define CREATE_TRACE_POINTS | |
46 | #include <trace/events/block.h> | |
1da177e4 | 47 | |
8324aa91 | 48 | #include "blk.h" |
43a5e4e2 | 49 | #include "blk-mq.h" |
bd166ef1 | 50 | #include "blk-mq-sched.h" |
bca6b067 | 51 | #include "blk-pm.h" |
c1c80384 | 52 | #include "blk-rq-qos.h" |
8324aa91 | 53 | |
18fbda91 | 54 | struct dentry *blk_debugfs_root; |
18fbda91 | 55 | |
d07335e5 | 56 | EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap); |
b0da3f0d | 57 | EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap); |
0a82a8d1 | 58 | EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_complete); |
3291fa57 | 59 | EXPORT_TRACEPOINT_SYMBOL_GPL(block_split); |
cbae8d45 | 60 | EXPORT_TRACEPOINT_SYMBOL_GPL(block_unplug); |
0bfc2455 | 61 | |
a73f730d TH |
62 | DEFINE_IDA(blk_queue_ida); |
63 | ||
1da177e4 LT |
64 | /* |
65 | * For queue allocation | |
66 | */ | |
6728cb0e | 67 | struct kmem_cache *blk_requestq_cachep; |
1da177e4 | 68 | |
1da177e4 LT |
69 | /* |
70 | * Controlling structure to kblockd | |
71 | */ | |
ff856bad | 72 | static struct workqueue_struct *kblockd_workqueue; |
1da177e4 | 73 | |
8814ce8a BVA |
74 | /** |
75 | * blk_queue_flag_set - atomically set a queue flag | |
76 | * @flag: flag to be set | |
77 | * @q: request queue | |
78 | */ | |
79 | void blk_queue_flag_set(unsigned int flag, struct request_queue *q) | |
80 | { | |
57d74df9 | 81 | set_bit(flag, &q->queue_flags); |
8814ce8a BVA |
82 | } |
83 | EXPORT_SYMBOL(blk_queue_flag_set); | |
84 | ||
85 | /** | |
86 | * blk_queue_flag_clear - atomically clear a queue flag | |
87 | * @flag: flag to be cleared | |
88 | * @q: request queue | |
89 | */ | |
90 | void blk_queue_flag_clear(unsigned int flag, struct request_queue *q) | |
91 | { | |
57d74df9 | 92 | clear_bit(flag, &q->queue_flags); |
8814ce8a BVA |
93 | } |
94 | EXPORT_SYMBOL(blk_queue_flag_clear); | |
95 | ||
96 | /** | |
97 | * blk_queue_flag_test_and_set - atomically test and set a queue flag | |
98 | * @flag: flag to be set | |
99 | * @q: request queue | |
100 | * | |
101 | * Returns the previous value of @flag - 0 if the flag was not set and 1 if | |
102 | * the flag was already set. | |
103 | */ | |
104 | bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q) | |
105 | { | |
57d74df9 | 106 | return test_and_set_bit(flag, &q->queue_flags); |
8814ce8a BVA |
107 | } |
108 | EXPORT_SYMBOL_GPL(blk_queue_flag_test_and_set); | |
109 | ||
2a4aa30c | 110 | void blk_rq_init(struct request_queue *q, struct request *rq) |
1da177e4 | 111 | { |
1afb20f3 FT |
112 | memset(rq, 0, sizeof(*rq)); |
113 | ||
1da177e4 | 114 | INIT_LIST_HEAD(&rq->queuelist); |
63a71386 | 115 | rq->q = q; |
a2dec7b3 | 116 | rq->__sector = (sector_t) -1; |
2e662b65 JA |
117 | INIT_HLIST_NODE(&rq->hash); |
118 | RB_CLEAR_NODE(&rq->rb_node); | |
63a71386 | 119 | rq->tag = -1; |
bd166ef1 | 120 | rq->internal_tag = -1; |
522a7775 | 121 | rq->start_time_ns = ktime_get_ns(); |
09e099d4 | 122 | rq->part = NULL; |
b554db14 | 123 | refcount_set(&rq->ref, 1); |
a892c8d5 | 124 | blk_crypto_rq_set_defaults(rq); |
1da177e4 | 125 | } |
2a4aa30c | 126 | EXPORT_SYMBOL(blk_rq_init); |
1da177e4 | 127 | |
e47bc4ed CK |
128 | #define REQ_OP_NAME(name) [REQ_OP_##name] = #name |
129 | static const char *const blk_op_name[] = { | |
130 | REQ_OP_NAME(READ), | |
131 | REQ_OP_NAME(WRITE), | |
132 | REQ_OP_NAME(FLUSH), | |
133 | REQ_OP_NAME(DISCARD), | |
134 | REQ_OP_NAME(SECURE_ERASE), | |
135 | REQ_OP_NAME(ZONE_RESET), | |
6e33dbf2 | 136 | REQ_OP_NAME(ZONE_RESET_ALL), |
6c1b1da5 AJ |
137 | REQ_OP_NAME(ZONE_OPEN), |
138 | REQ_OP_NAME(ZONE_CLOSE), | |
139 | REQ_OP_NAME(ZONE_FINISH), | |
0512a75b | 140 | REQ_OP_NAME(ZONE_APPEND), |
e47bc4ed CK |
141 | REQ_OP_NAME(WRITE_SAME), |
142 | REQ_OP_NAME(WRITE_ZEROES), | |
143 | REQ_OP_NAME(SCSI_IN), | |
144 | REQ_OP_NAME(SCSI_OUT), | |
145 | REQ_OP_NAME(DRV_IN), | |
146 | REQ_OP_NAME(DRV_OUT), | |
147 | }; | |
148 | #undef REQ_OP_NAME | |
149 | ||
150 | /** | |
151 | * blk_op_str - Return string XXX in the REQ_OP_XXX. | |
152 | * @op: REQ_OP_XXX. | |
153 | * | |
154 | * Description: Centralize block layer function to convert REQ_OP_XXX into | |
155 | * string format. Useful in the debugging and tracing bio or request. For | |
156 | * invalid REQ_OP_XXX it returns string "UNKNOWN". | |
157 | */ | |
158 | inline const char *blk_op_str(unsigned int op) | |
159 | { | |
160 | const char *op_str = "UNKNOWN"; | |
161 | ||
162 | if (op < ARRAY_SIZE(blk_op_name) && blk_op_name[op]) | |
163 | op_str = blk_op_name[op]; | |
164 | ||
165 | return op_str; | |
166 | } | |
167 | EXPORT_SYMBOL_GPL(blk_op_str); | |
168 | ||
2a842aca CH |
169 | static const struct { |
170 | int errno; | |
171 | const char *name; | |
172 | } blk_errors[] = { | |
173 | [BLK_STS_OK] = { 0, "" }, | |
174 | [BLK_STS_NOTSUPP] = { -EOPNOTSUPP, "operation not supported" }, | |
175 | [BLK_STS_TIMEOUT] = { -ETIMEDOUT, "timeout" }, | |
176 | [BLK_STS_NOSPC] = { -ENOSPC, "critical space allocation" }, | |
177 | [BLK_STS_TRANSPORT] = { -ENOLINK, "recoverable transport" }, | |
178 | [BLK_STS_TARGET] = { -EREMOTEIO, "critical target" }, | |
179 | [BLK_STS_NEXUS] = { -EBADE, "critical nexus" }, | |
180 | [BLK_STS_MEDIUM] = { -ENODATA, "critical medium" }, | |
181 | [BLK_STS_PROTECTION] = { -EILSEQ, "protection" }, | |
182 | [BLK_STS_RESOURCE] = { -ENOMEM, "kernel resource" }, | |
86ff7c2a | 183 | [BLK_STS_DEV_RESOURCE] = { -EBUSY, "device resource" }, |
03a07c92 | 184 | [BLK_STS_AGAIN] = { -EAGAIN, "nonblocking retry" }, |
2a842aca | 185 | |
4e4cbee9 CH |
186 | /* device mapper special case, should not leak out: */ |
187 | [BLK_STS_DM_REQUEUE] = { -EREMCHG, "dm internal retry" }, | |
188 | ||
2a842aca CH |
189 | /* everything else not covered above: */ |
190 | [BLK_STS_IOERR] = { -EIO, "I/O" }, | |
191 | }; | |
192 | ||
193 | blk_status_t errno_to_blk_status(int errno) | |
194 | { | |
195 | int i; | |
196 | ||
197 | for (i = 0; i < ARRAY_SIZE(blk_errors); i++) { | |
198 | if (blk_errors[i].errno == errno) | |
199 | return (__force blk_status_t)i; | |
200 | } | |
201 | ||
202 | return BLK_STS_IOERR; | |
203 | } | |
204 | EXPORT_SYMBOL_GPL(errno_to_blk_status); | |
205 | ||
206 | int blk_status_to_errno(blk_status_t status) | |
207 | { | |
208 | int idx = (__force int)status; | |
209 | ||
34bd9c1c | 210 | if (WARN_ON_ONCE(idx >= ARRAY_SIZE(blk_errors))) |
2a842aca CH |
211 | return -EIO; |
212 | return blk_errors[idx].errno; | |
213 | } | |
214 | EXPORT_SYMBOL_GPL(blk_status_to_errno); | |
215 | ||
178cc590 CH |
216 | static void print_req_error(struct request *req, blk_status_t status, |
217 | const char *caller) | |
2a842aca CH |
218 | { |
219 | int idx = (__force int)status; | |
220 | ||
34bd9c1c | 221 | if (WARN_ON_ONCE(idx >= ARRAY_SIZE(blk_errors))) |
2a842aca CH |
222 | return; |
223 | ||
178cc590 | 224 | printk_ratelimited(KERN_ERR |
b0e5168a CK |
225 | "%s: %s error, dev %s, sector %llu op 0x%x:(%s) flags 0x%x " |
226 | "phys_seg %u prio class %u\n", | |
178cc590 | 227 | caller, blk_errors[idx].name, |
b0e5168a CK |
228 | req->rq_disk ? req->rq_disk->disk_name : "?", |
229 | blk_rq_pos(req), req_op(req), blk_op_str(req_op(req)), | |
230 | req->cmd_flags & ~REQ_OP_MASK, | |
231 | req->nr_phys_segments, | |
232 | IOPRIO_PRIO_CLASS(req->ioprio)); | |
2a842aca CH |
233 | } |
234 | ||
5bb23a68 | 235 | static void req_bio_endio(struct request *rq, struct bio *bio, |
2a842aca | 236 | unsigned int nbytes, blk_status_t error) |
1da177e4 | 237 | { |
78d8e58a | 238 | if (error) |
4e4cbee9 | 239 | bio->bi_status = error; |
797e7dbb | 240 | |
e8064021 | 241 | if (unlikely(rq->rq_flags & RQF_QUIET)) |
b7c44ed9 | 242 | bio_set_flag(bio, BIO_QUIET); |
08bafc03 | 243 | |
f79ea416 | 244 | bio_advance(bio, nbytes); |
7ba1ba12 | 245 | |
0512a75b KB |
246 | if (req_op(rq) == REQ_OP_ZONE_APPEND && error == BLK_STS_OK) { |
247 | /* | |
248 | * Partial zone append completions cannot be supported as the | |
249 | * BIO fragments may end up not being written sequentially. | |
250 | */ | |
251 | if (bio->bi_iter.bi_size) | |
252 | bio->bi_status = BLK_STS_IOERR; | |
253 | else | |
254 | bio->bi_iter.bi_sector = rq->__sector; | |
255 | } | |
256 | ||
143a87f4 | 257 | /* don't actually finish bio if it's part of flush sequence */ |
e8064021 | 258 | if (bio->bi_iter.bi_size == 0 && !(rq->rq_flags & RQF_FLUSH_SEQ)) |
4246a0b6 | 259 | bio_endio(bio); |
1da177e4 | 260 | } |
1da177e4 | 261 | |
1da177e4 LT |
262 | void blk_dump_rq_flags(struct request *rq, char *msg) |
263 | { | |
aebf526b CH |
264 | printk(KERN_INFO "%s: dev %s: flags=%llx\n", msg, |
265 | rq->rq_disk ? rq->rq_disk->disk_name : "?", | |
5953316d | 266 | (unsigned long long) rq->cmd_flags); |
1da177e4 | 267 | |
83096ebf TH |
268 | printk(KERN_INFO " sector %llu, nr/cnr %u/%u\n", |
269 | (unsigned long long)blk_rq_pos(rq), | |
270 | blk_rq_sectors(rq), blk_rq_cur_sectors(rq)); | |
b4f42e28 JA |
271 | printk(KERN_INFO " bio %p, biotail %p, len %u\n", |
272 | rq->bio, rq->biotail, blk_rq_bytes(rq)); | |
1da177e4 | 273 | } |
1da177e4 LT |
274 | EXPORT_SYMBOL(blk_dump_rq_flags); |
275 | ||
1da177e4 LT |
276 | /** |
277 | * blk_sync_queue - cancel any pending callbacks on a queue | |
278 | * @q: the queue | |
279 | * | |
280 | * Description: | |
281 | * The block layer may perform asynchronous callback activity | |
282 | * on a queue, such as calling the unplug function after a timeout. | |
283 | * A block device may call blk_sync_queue to ensure that any | |
284 | * such activity is cancelled, thus allowing it to release resources | |
59c51591 | 285 | * that the callbacks might use. The caller must already have made sure |
c62b37d9 | 286 | * that its ->submit_bio will not re-add plugging prior to calling |
1da177e4 LT |
287 | * this function. |
288 | * | |
da527770 | 289 | * This function does not cancel any asynchronous activity arising |
da3dae54 | 290 | * out of elevator or throttling code. That would require elevator_exit() |
5efd6113 | 291 | * and blkcg_exit_queue() to be called with queue lock initialized. |
da527770 | 292 | * |
1da177e4 LT |
293 | */ |
294 | void blk_sync_queue(struct request_queue *q) | |
295 | { | |
70ed28b9 | 296 | del_timer_sync(&q->timeout); |
4e9b6f20 | 297 | cancel_work_sync(&q->timeout_work); |
1da177e4 LT |
298 | } |
299 | EXPORT_SYMBOL(blk_sync_queue); | |
300 | ||
c9254f2d | 301 | /** |
cd84a62e | 302 | * blk_set_pm_only - increment pm_only counter |
c9254f2d | 303 | * @q: request queue pointer |
c9254f2d | 304 | */ |
cd84a62e | 305 | void blk_set_pm_only(struct request_queue *q) |
c9254f2d | 306 | { |
cd84a62e | 307 | atomic_inc(&q->pm_only); |
c9254f2d | 308 | } |
cd84a62e | 309 | EXPORT_SYMBOL_GPL(blk_set_pm_only); |
c9254f2d | 310 | |
cd84a62e | 311 | void blk_clear_pm_only(struct request_queue *q) |
c9254f2d | 312 | { |
cd84a62e BVA |
313 | int pm_only; |
314 | ||
315 | pm_only = atomic_dec_return(&q->pm_only); | |
316 | WARN_ON_ONCE(pm_only < 0); | |
317 | if (pm_only == 0) | |
318 | wake_up_all(&q->mq_freeze_wq); | |
c9254f2d | 319 | } |
cd84a62e | 320 | EXPORT_SYMBOL_GPL(blk_clear_pm_only); |
c9254f2d | 321 | |
b5bd357c LC |
322 | /** |
323 | * blk_put_queue - decrement the request_queue refcount | |
324 | * @q: the request_queue structure to decrement the refcount for | |
325 | * | |
326 | * Decrements the refcount of the request_queue kobject. When this reaches 0 | |
327 | * we'll have blk_release_queue() called. | |
e8c7d14a LC |
328 | * |
329 | * Context: Any context, but the last reference must not be dropped from | |
330 | * atomic context. | |
b5bd357c | 331 | */ |
165125e1 | 332 | void blk_put_queue(struct request_queue *q) |
483f4afc AV |
333 | { |
334 | kobject_put(&q->kobj); | |
335 | } | |
d86e0e83 | 336 | EXPORT_SYMBOL(blk_put_queue); |
483f4afc | 337 | |
aed3ea94 JA |
338 | void blk_set_queue_dying(struct request_queue *q) |
339 | { | |
8814ce8a | 340 | blk_queue_flag_set(QUEUE_FLAG_DYING, q); |
aed3ea94 | 341 | |
d3cfb2a0 ML |
342 | /* |
343 | * When queue DYING flag is set, we need to block new req | |
344 | * entering queue, so we call blk_freeze_queue_start() to | |
345 | * prevent I/O from crossing blk_queue_enter(). | |
346 | */ | |
347 | blk_freeze_queue_start(q); | |
348 | ||
344e9ffc | 349 | if (queue_is_mq(q)) |
aed3ea94 | 350 | blk_mq_wake_waiters(q); |
055f6e18 ML |
351 | |
352 | /* Make blk_queue_enter() reexamine the DYING flag. */ | |
353 | wake_up_all(&q->mq_freeze_wq); | |
aed3ea94 JA |
354 | } |
355 | EXPORT_SYMBOL_GPL(blk_set_queue_dying); | |
356 | ||
c9a929dd TH |
357 | /** |
358 | * blk_cleanup_queue - shutdown a request queue | |
359 | * @q: request queue to shutdown | |
360 | * | |
c246e80d BVA |
361 | * Mark @q DYING, drain all pending requests, mark @q DEAD, destroy and |
362 | * put it. All future requests will be failed immediately with -ENODEV. | |
e8c7d14a LC |
363 | * |
364 | * Context: can sleep | |
c94a96ac | 365 | */ |
6728cb0e | 366 | void blk_cleanup_queue(struct request_queue *q) |
483f4afc | 367 | { |
e8c7d14a LC |
368 | /* cannot be called from atomic context */ |
369 | might_sleep(); | |
370 | ||
bae85c15 BVA |
371 | WARN_ON_ONCE(blk_queue_registered(q)); |
372 | ||
3f3299d5 | 373 | /* mark @q DYING, no new request or merges will be allowed afterwards */ |
aed3ea94 | 374 | blk_set_queue_dying(q); |
6ecf23af | 375 | |
57d74df9 CH |
376 | blk_queue_flag_set(QUEUE_FLAG_NOMERGES, q); |
377 | blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, q); | |
c9a929dd | 378 | |
c246e80d BVA |
379 | /* |
380 | * Drain all requests queued before DYING marking. Set DEAD flag to | |
67ed8b73 BVA |
381 | * prevent that blk_mq_run_hw_queues() accesses the hardware queues |
382 | * after draining finished. | |
c246e80d | 383 | */ |
3ef28e83 | 384 | blk_freeze_queue(q); |
c57cdf7a ML |
385 | |
386 | rq_qos_exit(q); | |
387 | ||
57d74df9 | 388 | blk_queue_flag_set(QUEUE_FLAG_DEAD, q); |
c9a929dd | 389 | |
5a48fc14 DW |
390 | /* for synchronous bio-based driver finish in-flight integrity i/o */ |
391 | blk_flush_integrity(); | |
392 | ||
c9a929dd | 393 | /* @q won't process any more request, flush async actions */ |
dc3b17cc | 394 | del_timer_sync(&q->backing_dev_info->laptop_mode_wb_timer); |
c9a929dd TH |
395 | blk_sync_queue(q); |
396 | ||
344e9ffc | 397 | if (queue_is_mq(q)) |
c7e2d94b | 398 | blk_mq_exit_queue(q); |
a1ce35fa | 399 | |
c3e22192 ML |
400 | /* |
401 | * In theory, request pool of sched_tags belongs to request queue. | |
402 | * However, the current implementation requires tag_set for freeing | |
403 | * requests, so free the pool now. | |
404 | * | |
405 | * Queue has become frozen, there can't be any in-queue requests, so | |
406 | * it is safe to free requests now. | |
407 | */ | |
408 | mutex_lock(&q->sysfs_lock); | |
409 | if (q->elevator) | |
410 | blk_mq_sched_free_requests(q); | |
411 | mutex_unlock(&q->sysfs_lock); | |
412 | ||
3ef28e83 | 413 | percpu_ref_exit(&q->q_usage_counter); |
45a9c9d9 | 414 | |
c9a929dd | 415 | /* @q is and will stay empty, shutdown and put */ |
483f4afc AV |
416 | blk_put_queue(q); |
417 | } | |
1da177e4 LT |
418 | EXPORT_SYMBOL(blk_cleanup_queue); |
419 | ||
3a0a5299 BVA |
420 | /** |
421 | * blk_queue_enter() - try to increase q->q_usage_counter | |
422 | * @q: request queue pointer | |
423 | * @flags: BLK_MQ_REQ_NOWAIT and/or BLK_MQ_REQ_PREEMPT | |
424 | */ | |
9a95e4ef | 425 | int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags) |
3ef28e83 | 426 | { |
cd84a62e | 427 | const bool pm = flags & BLK_MQ_REQ_PREEMPT; |
3a0a5299 | 428 | |
3ef28e83 | 429 | while (true) { |
3a0a5299 | 430 | bool success = false; |
3ef28e83 | 431 | |
818e0fa2 | 432 | rcu_read_lock(); |
3a0a5299 BVA |
433 | if (percpu_ref_tryget_live(&q->q_usage_counter)) { |
434 | /* | |
cd84a62e BVA |
435 | * The code that increments the pm_only counter is |
436 | * responsible for ensuring that that counter is | |
437 | * globally visible before the queue is unfrozen. | |
3a0a5299 | 438 | */ |
cd84a62e | 439 | if (pm || !blk_queue_pm_only(q)) { |
3a0a5299 BVA |
440 | success = true; |
441 | } else { | |
442 | percpu_ref_put(&q->q_usage_counter); | |
443 | } | |
444 | } | |
818e0fa2 | 445 | rcu_read_unlock(); |
3a0a5299 BVA |
446 | |
447 | if (success) | |
3ef28e83 DW |
448 | return 0; |
449 | ||
3a0a5299 | 450 | if (flags & BLK_MQ_REQ_NOWAIT) |
3ef28e83 DW |
451 | return -EBUSY; |
452 | ||
5ed61d3f | 453 | /* |
1671d522 | 454 | * read pair of barrier in blk_freeze_queue_start(), |
5ed61d3f | 455 | * we need to order reading __PERCPU_REF_DEAD flag of |
d3cfb2a0 ML |
456 | * .q_usage_counter and reading .mq_freeze_depth or |
457 | * queue dying flag, otherwise the following wait may | |
458 | * never return if the two reads are reordered. | |
5ed61d3f ML |
459 | */ |
460 | smp_rmb(); | |
461 | ||
1dc3039b | 462 | wait_event(q->mq_freeze_wq, |
7996a8b5 | 463 | (!q->mq_freeze_depth && |
0d25bd07 BVA |
464 | (pm || (blk_pm_request_resume(q), |
465 | !blk_queue_pm_only(q)))) || | |
1dc3039b | 466 | blk_queue_dying(q)); |
3ef28e83 DW |
467 | if (blk_queue_dying(q)) |
468 | return -ENODEV; | |
3ef28e83 DW |
469 | } |
470 | } | |
471 | ||
accea322 CH |
472 | static inline int bio_queue_enter(struct bio *bio) |
473 | { | |
474 | struct request_queue *q = bio->bi_disk->queue; | |
475 | bool nowait = bio->bi_opf & REQ_NOWAIT; | |
476 | int ret; | |
477 | ||
478 | ret = blk_queue_enter(q, nowait ? BLK_MQ_REQ_NOWAIT : 0); | |
479 | if (unlikely(ret)) { | |
480 | if (nowait && !blk_queue_dying(q)) | |
481 | bio_wouldblock_error(bio); | |
482 | else | |
483 | bio_io_error(bio); | |
484 | } | |
485 | ||
486 | return ret; | |
487 | } | |
488 | ||
3ef28e83 DW |
489 | void blk_queue_exit(struct request_queue *q) |
490 | { | |
491 | percpu_ref_put(&q->q_usage_counter); | |
492 | } | |
493 | ||
494 | static void blk_queue_usage_counter_release(struct percpu_ref *ref) | |
495 | { | |
496 | struct request_queue *q = | |
497 | container_of(ref, struct request_queue, q_usage_counter); | |
498 | ||
499 | wake_up_all(&q->mq_freeze_wq); | |
500 | } | |
501 | ||
bca237a5 | 502 | static void blk_rq_timed_out_timer(struct timer_list *t) |
287922eb | 503 | { |
bca237a5 | 504 | struct request_queue *q = from_timer(q, t, timeout); |
287922eb CH |
505 | |
506 | kblockd_schedule_work(&q->timeout_work); | |
507 | } | |
508 | ||
2e3c18d0 TH |
509 | static void blk_timeout_work(struct work_struct *work) |
510 | { | |
511 | } | |
512 | ||
c62b37d9 | 513 | struct request_queue *blk_alloc_queue(int node_id) |
1946089a | 514 | { |
165125e1 | 515 | struct request_queue *q; |
338aa96d | 516 | int ret; |
1946089a | 517 | |
8324aa91 | 518 | q = kmem_cache_alloc_node(blk_requestq_cachep, |
3d745ea5 | 519 | GFP_KERNEL | __GFP_ZERO, node_id); |
1da177e4 LT |
520 | if (!q) |
521 | return NULL; | |
522 | ||
cbf62af3 | 523 | q->last_merge = NULL; |
cbf62af3 | 524 | |
3d745ea5 | 525 | q->id = ida_simple_get(&blk_queue_ida, 0, 0, GFP_KERNEL); |
a73f730d | 526 | if (q->id < 0) |
3d2936f4 | 527 | goto fail_q; |
a73f730d | 528 | |
338aa96d KO |
529 | ret = bioset_init(&q->bio_split, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS); |
530 | if (ret) | |
54efd50b KO |
531 | goto fail_id; |
532 | ||
aef33c2f | 533 | q->backing_dev_info = bdi_alloc(node_id); |
d03f6cdc JK |
534 | if (!q->backing_dev_info) |
535 | goto fail_split; | |
536 | ||
a83b576c JA |
537 | q->stats = blk_alloc_queue_stats(); |
538 | if (!q->stats) | |
539 | goto fail_stats; | |
540 | ||
b5420237 | 541 | q->backing_dev_info->ra_pages = VM_READAHEAD_PAGES; |
dc3b17cc | 542 | q->backing_dev_info->capabilities = BDI_CAP_CGROUP_WRITEBACK; |
5151412d | 543 | q->node = node_id; |
0989a025 | 544 | |
bca237a5 KC |
545 | timer_setup(&q->backing_dev_info->laptop_mode_wb_timer, |
546 | laptop_mode_timer_fn, 0); | |
547 | timer_setup(&q->timeout, blk_rq_timed_out_timer, 0); | |
2e3c18d0 | 548 | INIT_WORK(&q->timeout_work, blk_timeout_work); |
a612fddf | 549 | INIT_LIST_HEAD(&q->icq_list); |
4eef3049 | 550 | #ifdef CONFIG_BLK_CGROUP |
e8989fae | 551 | INIT_LIST_HEAD(&q->blkg_list); |
4eef3049 | 552 | #endif |
483f4afc | 553 | |
8324aa91 | 554 | kobject_init(&q->kobj, &blk_queue_ktype); |
1da177e4 | 555 | |
85e0cbbb | 556 | mutex_init(&q->debugfs_mutex); |
483f4afc | 557 | mutex_init(&q->sysfs_lock); |
cecf5d87 | 558 | mutex_init(&q->sysfs_dir_lock); |
0d945c1f | 559 | spin_lock_init(&q->queue_lock); |
c94a96ac | 560 | |
320ae51f | 561 | init_waitqueue_head(&q->mq_freeze_wq); |
7996a8b5 | 562 | mutex_init(&q->mq_freeze_lock); |
320ae51f | 563 | |
3ef28e83 DW |
564 | /* |
565 | * Init percpu_ref in atomic mode so that it's faster to shutdown. | |
566 | * See blk_register_queue() for details. | |
567 | */ | |
568 | if (percpu_ref_init(&q->q_usage_counter, | |
569 | blk_queue_usage_counter_release, | |
570 | PERCPU_REF_INIT_ATOMIC, GFP_KERNEL)) | |
fff4996b | 571 | goto fail_bdi; |
f51b802c | 572 | |
3ef28e83 DW |
573 | if (blkcg_init_queue(q)) |
574 | goto fail_ref; | |
575 | ||
3d745ea5 CH |
576 | blk_queue_dma_alignment(q, 511); |
577 | blk_set_default_limits(&q->limits); | |
c62b37d9 | 578 | q->nr_requests = BLKDEV_MAX_RQ; |
3d745ea5 | 579 | |
1da177e4 | 580 | return q; |
a73f730d | 581 | |
3ef28e83 DW |
582 | fail_ref: |
583 | percpu_ref_exit(&q->q_usage_counter); | |
fff4996b | 584 | fail_bdi: |
a83b576c JA |
585 | blk_free_queue_stats(q->stats); |
586 | fail_stats: | |
d03f6cdc | 587 | bdi_put(q->backing_dev_info); |
54efd50b | 588 | fail_split: |
338aa96d | 589 | bioset_exit(&q->bio_split); |
a73f730d TH |
590 | fail_id: |
591 | ida_simple_remove(&blk_queue_ida, q->id); | |
592 | fail_q: | |
593 | kmem_cache_free(blk_requestq_cachep, q); | |
594 | return NULL; | |
1da177e4 | 595 | } |
3d745ea5 | 596 | EXPORT_SYMBOL(blk_alloc_queue); |
1da177e4 | 597 | |
b5bd357c LC |
598 | /** |
599 | * blk_get_queue - increment the request_queue refcount | |
600 | * @q: the request_queue structure to increment the refcount for | |
601 | * | |
602 | * Increment the refcount of the request_queue kobject. | |
763b5892 LC |
603 | * |
604 | * Context: Any context. | |
b5bd357c | 605 | */ |
09ac46c4 | 606 | bool blk_get_queue(struct request_queue *q) |
1da177e4 | 607 | { |
3f3299d5 | 608 | if (likely(!blk_queue_dying(q))) { |
09ac46c4 TH |
609 | __blk_get_queue(q); |
610 | return true; | |
1da177e4 LT |
611 | } |
612 | ||
09ac46c4 | 613 | return false; |
1da177e4 | 614 | } |
d86e0e83 | 615 | EXPORT_SYMBOL(blk_get_queue); |
1da177e4 | 616 | |
a1ce35fa JA |
617 | /** |
618 | * blk_get_request - allocate a request | |
619 | * @q: request queue to allocate a request for | |
620 | * @op: operation (REQ_OP_*) and REQ_* flags, e.g. REQ_SYNC. | |
621 | * @flags: BLK_MQ_REQ_* flags, e.g. BLK_MQ_REQ_NOWAIT. | |
1da177e4 | 622 | */ |
a1ce35fa JA |
623 | struct request *blk_get_request(struct request_queue *q, unsigned int op, |
624 | blk_mq_req_flags_t flags) | |
1da177e4 | 625 | { |
a1ce35fa | 626 | struct request *req; |
1da177e4 | 627 | |
a1ce35fa JA |
628 | WARN_ON_ONCE(op & REQ_NOWAIT); |
629 | WARN_ON_ONCE(flags & ~(BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_PREEMPT)); | |
1da177e4 | 630 | |
a1ce35fa JA |
631 | req = blk_mq_alloc_request(q, op, flags); |
632 | if (!IS_ERR(req) && q->mq_ops->initialize_rq_fn) | |
633 | q->mq_ops->initialize_rq_fn(req); | |
1da177e4 | 634 | |
a1ce35fa | 635 | return req; |
1da177e4 | 636 | } |
a1ce35fa | 637 | EXPORT_SYMBOL(blk_get_request); |
1da177e4 | 638 | |
1da177e4 LT |
639 | void blk_put_request(struct request *req) |
640 | { | |
a1ce35fa | 641 | blk_mq_free_request(req); |
1da177e4 | 642 | } |
1da177e4 LT |
643 | EXPORT_SYMBOL(blk_put_request); |
644 | ||
b5af37ab KK |
645 | static void blk_account_io_merge_bio(struct request *req) |
646 | { | |
647 | if (!blk_do_io_stat(req)) | |
648 | return; | |
649 | ||
650 | part_stat_lock(); | |
651 | part_stat_inc(req->part, merges[op_stat_group(req_op(req))]); | |
652 | part_stat_unlock(); | |
653 | } | |
654 | ||
14ccb66b CH |
655 | bool bio_attempt_back_merge(struct request *req, struct bio *bio, |
656 | unsigned int nr_segs) | |
73c10101 | 657 | { |
1eff9d32 | 658 | const int ff = bio->bi_opf & REQ_FAILFAST_MASK; |
73c10101 | 659 | |
14ccb66b | 660 | if (!ll_back_merge_fn(req, bio, nr_segs)) |
73c10101 JA |
661 | return false; |
662 | ||
14ccb66b | 663 | trace_block_bio_backmerge(req->q, req, bio); |
d3e65fff | 664 | rq_qos_merge(req->q, req, bio); |
73c10101 JA |
665 | |
666 | if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff) | |
667 | blk_rq_set_mixed_merge(req); | |
668 | ||
669 | req->biotail->bi_next = bio; | |
670 | req->biotail = bio; | |
4f024f37 | 671 | req->__data_len += bio->bi_iter.bi_size; |
73c10101 | 672 | |
a892c8d5 ST |
673 | bio_crypt_free_ctx(bio); |
674 | ||
b5af37ab | 675 | blk_account_io_merge_bio(req); |
73c10101 JA |
676 | return true; |
677 | } | |
678 | ||
14ccb66b CH |
679 | bool bio_attempt_front_merge(struct request *req, struct bio *bio, |
680 | unsigned int nr_segs) | |
73c10101 | 681 | { |
1eff9d32 | 682 | const int ff = bio->bi_opf & REQ_FAILFAST_MASK; |
73c10101 | 683 | |
14ccb66b | 684 | if (!ll_front_merge_fn(req, bio, nr_segs)) |
73c10101 JA |
685 | return false; |
686 | ||
14ccb66b | 687 | trace_block_bio_frontmerge(req->q, req, bio); |
d3e65fff | 688 | rq_qos_merge(req->q, req, bio); |
73c10101 JA |
689 | |
690 | if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff) | |
691 | blk_rq_set_mixed_merge(req); | |
692 | ||
73c10101 JA |
693 | bio->bi_next = req->bio; |
694 | req->bio = bio; | |
695 | ||
4f024f37 KO |
696 | req->__sector = bio->bi_iter.bi_sector; |
697 | req->__data_len += bio->bi_iter.bi_size; | |
73c10101 | 698 | |
a892c8d5 ST |
699 | bio_crypt_do_front_merge(req, bio); |
700 | ||
b5af37ab | 701 | blk_account_io_merge_bio(req); |
73c10101 JA |
702 | return true; |
703 | } | |
704 | ||
1e739730 CH |
705 | bool bio_attempt_discard_merge(struct request_queue *q, struct request *req, |
706 | struct bio *bio) | |
707 | { | |
708 | unsigned short segments = blk_rq_nr_discard_segments(req); | |
709 | ||
710 | if (segments >= queue_max_discard_segments(q)) | |
711 | goto no_merge; | |
712 | if (blk_rq_sectors(req) + bio_sectors(bio) > | |
713 | blk_rq_get_max_sectors(req, blk_rq_pos(req))) | |
714 | goto no_merge; | |
715 | ||
d3e65fff TH |
716 | rq_qos_merge(q, req, bio); |
717 | ||
1e739730 CH |
718 | req->biotail->bi_next = bio; |
719 | req->biotail = bio; | |
720 | req->__data_len += bio->bi_iter.bi_size; | |
1e739730 CH |
721 | req->nr_phys_segments = segments + 1; |
722 | ||
b5af37ab | 723 | blk_account_io_merge_bio(req); |
1e739730 CH |
724 | return true; |
725 | no_merge: | |
726 | req_set_nomerge(q, req); | |
727 | return false; | |
728 | } | |
729 | ||
bd87b589 | 730 | /** |
320ae51f | 731 | * blk_attempt_plug_merge - try to merge with %current's plugged list |
bd87b589 TH |
732 | * @q: request_queue new bio is being queued at |
733 | * @bio: new bio being queued | |
14ccb66b | 734 | * @nr_segs: number of segments in @bio |
ccc2600b RD |
735 | * @same_queue_rq: pointer to &struct request that gets filled in when |
736 | * another request associated with @q is found on the plug list | |
737 | * (optional, may be %NULL) | |
bd87b589 TH |
738 | * |
739 | * Determine whether @bio being queued on @q can be merged with a request | |
740 | * on %current's plugged list. Returns %true if merge was successful, | |
741 | * otherwise %false. | |
742 | * | |
07c2bd37 TH |
743 | * Plugging coalesces IOs from the same issuer for the same purpose without |
744 | * going through @q->queue_lock. As such it's more of an issuing mechanism | |
745 | * than scheduling, and the request, while may have elvpriv data, is not | |
746 | * added on the elevator at this point. In addition, we don't have | |
747 | * reliable access to the elevator outside queue lock. Only check basic | |
748 | * merging parameters without querying the elevator. | |
da41a589 RE |
749 | * |
750 | * Caller must ensure !blk_queue_nomerges(q) beforehand. | |
73c10101 | 751 | */ |
320ae51f | 752 | bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, |
14ccb66b | 753 | unsigned int nr_segs, struct request **same_queue_rq) |
73c10101 JA |
754 | { |
755 | struct blk_plug *plug; | |
756 | struct request *rq; | |
92f399c7 | 757 | struct list_head *plug_list; |
73c10101 | 758 | |
b49773e7 | 759 | plug = blk_mq_plug(q, bio); |
73c10101 | 760 | if (!plug) |
34fe7c05 | 761 | return false; |
73c10101 | 762 | |
a1ce35fa | 763 | plug_list = &plug->mq_list; |
92f399c7 SL |
764 | |
765 | list_for_each_entry_reverse(rq, plug_list, queuelist) { | |
34fe7c05 | 766 | bool merged = false; |
73c10101 | 767 | |
5f0ed774 | 768 | if (rq->q == q && same_queue_rq) { |
5b3f341f SL |
769 | /* |
770 | * Only blk-mq multiple hardware queues case checks the | |
771 | * rq in the same queue, there should be only one such | |
772 | * rq in a queue | |
773 | **/ | |
5f0ed774 | 774 | *same_queue_rq = rq; |
5b3f341f | 775 | } |
56ebdaf2 | 776 | |
07c2bd37 | 777 | if (rq->q != q || !blk_rq_merge_ok(rq, bio)) |
73c10101 JA |
778 | continue; |
779 | ||
34fe7c05 CH |
780 | switch (blk_try_merge(rq, bio)) { |
781 | case ELEVATOR_BACK_MERGE: | |
14ccb66b | 782 | merged = bio_attempt_back_merge(rq, bio, nr_segs); |
34fe7c05 CH |
783 | break; |
784 | case ELEVATOR_FRONT_MERGE: | |
14ccb66b | 785 | merged = bio_attempt_front_merge(rq, bio, nr_segs); |
34fe7c05 | 786 | break; |
1e739730 CH |
787 | case ELEVATOR_DISCARD_MERGE: |
788 | merged = bio_attempt_discard_merge(q, rq, bio); | |
789 | break; | |
34fe7c05 CH |
790 | default: |
791 | break; | |
73c10101 | 792 | } |
34fe7c05 CH |
793 | |
794 | if (merged) | |
795 | return true; | |
73c10101 | 796 | } |
34fe7c05 CH |
797 | |
798 | return false; | |
73c10101 JA |
799 | } |
800 | ||
52c5e62d | 801 | static void handle_bad_sector(struct bio *bio, sector_t maxsector) |
1da177e4 LT |
802 | { |
803 | char b[BDEVNAME_SIZE]; | |
804 | ||
805 | printk(KERN_INFO "attempt to access beyond end of device\n"); | |
6296b960 | 806 | printk(KERN_INFO "%s: rw=%d, want=%Lu, limit=%Lu\n", |
74d46992 | 807 | bio_devname(bio, b), bio->bi_opf, |
f73a1c7d | 808 | (unsigned long long)bio_end_sector(bio), |
52c5e62d | 809 | (long long)maxsector); |
1da177e4 LT |
810 | } |
811 | ||
c17bb495 AM |
812 | #ifdef CONFIG_FAIL_MAKE_REQUEST |
813 | ||
814 | static DECLARE_FAULT_ATTR(fail_make_request); | |
815 | ||
816 | static int __init setup_fail_make_request(char *str) | |
817 | { | |
818 | return setup_fault_attr(&fail_make_request, str); | |
819 | } | |
820 | __setup("fail_make_request=", setup_fail_make_request); | |
821 | ||
b2c9cd37 | 822 | static bool should_fail_request(struct hd_struct *part, unsigned int bytes) |
c17bb495 | 823 | { |
b2c9cd37 | 824 | return part->make_it_fail && should_fail(&fail_make_request, bytes); |
c17bb495 AM |
825 | } |
826 | ||
827 | static int __init fail_make_request_debugfs(void) | |
828 | { | |
dd48c085 AM |
829 | struct dentry *dir = fault_create_debugfs_attr("fail_make_request", |
830 | NULL, &fail_make_request); | |
831 | ||
21f9fcd8 | 832 | return PTR_ERR_OR_ZERO(dir); |
c17bb495 AM |
833 | } |
834 | ||
835 | late_initcall(fail_make_request_debugfs); | |
836 | ||
837 | #else /* CONFIG_FAIL_MAKE_REQUEST */ | |
838 | ||
b2c9cd37 AM |
839 | static inline bool should_fail_request(struct hd_struct *part, |
840 | unsigned int bytes) | |
c17bb495 | 841 | { |
b2c9cd37 | 842 | return false; |
c17bb495 AM |
843 | } |
844 | ||
845 | #endif /* CONFIG_FAIL_MAKE_REQUEST */ | |
846 | ||
721c7fc7 ID |
847 | static inline bool bio_check_ro(struct bio *bio, struct hd_struct *part) |
848 | { | |
b089cfd9 JA |
849 | const int op = bio_op(bio); |
850 | ||
8b2ded1c | 851 | if (part->policy && op_is_write(op)) { |
721c7fc7 ID |
852 | char b[BDEVNAME_SIZE]; |
853 | ||
8b2ded1c MP |
854 | if (op_is_flush(bio->bi_opf) && !bio_sectors(bio)) |
855 | return false; | |
856 | ||
a32e236e | 857 | WARN_ONCE(1, |
c8178674 | 858 | "Trying to write to read-only block-device %s (partno %d)\n", |
721c7fc7 | 859 | bio_devname(bio, b), part->partno); |
a32e236e LT |
860 | /* Older lvm-tools actually trigger this */ |
861 | return false; | |
721c7fc7 ID |
862 | } |
863 | ||
864 | return false; | |
865 | } | |
866 | ||
30abb3a6 HM |
867 | static noinline int should_fail_bio(struct bio *bio) |
868 | { | |
869 | if (should_fail_request(&bio->bi_disk->part0, bio->bi_iter.bi_size)) | |
870 | return -EIO; | |
871 | return 0; | |
872 | } | |
873 | ALLOW_ERROR_INJECTION(should_fail_bio, ERRNO); | |
874 | ||
52c5e62d CH |
875 | /* |
876 | * Check whether this bio extends beyond the end of the device or partition. | |
877 | * This may well happen - the kernel calls bread() without checking the size of | |
878 | * the device, e.g., when mounting a file system. | |
879 | */ | |
880 | static inline int bio_check_eod(struct bio *bio, sector_t maxsector) | |
881 | { | |
882 | unsigned int nr_sectors = bio_sectors(bio); | |
883 | ||
884 | if (nr_sectors && maxsector && | |
885 | (nr_sectors > maxsector || | |
886 | bio->bi_iter.bi_sector > maxsector - nr_sectors)) { | |
887 | handle_bad_sector(bio, maxsector); | |
888 | return -EIO; | |
889 | } | |
890 | return 0; | |
891 | } | |
892 | ||
74d46992 CH |
893 | /* |
894 | * Remap block n of partition p to block n+start(p) of the disk. | |
895 | */ | |
896 | static inline int blk_partition_remap(struct bio *bio) | |
897 | { | |
898 | struct hd_struct *p; | |
52c5e62d | 899 | int ret = -EIO; |
74d46992 | 900 | |
721c7fc7 ID |
901 | rcu_read_lock(); |
902 | p = __disk_get_part(bio->bi_disk, bio->bi_partno); | |
52c5e62d CH |
903 | if (unlikely(!p)) |
904 | goto out; | |
905 | if (unlikely(should_fail_request(p, bio->bi_iter.bi_size))) | |
906 | goto out; | |
907 | if (unlikely(bio_check_ro(bio, p))) | |
721c7fc7 | 908 | goto out; |
721c7fc7 | 909 | |
5eac3eb3 | 910 | if (bio_sectors(bio)) { |
52c5e62d CH |
911 | if (bio_check_eod(bio, part_nr_sects_read(p))) |
912 | goto out; | |
913 | bio->bi_iter.bi_sector += p->start_sect; | |
52c5e62d CH |
914 | trace_block_bio_remap(bio->bi_disk->queue, bio, part_devt(p), |
915 | bio->bi_iter.bi_sector - p->start_sect); | |
916 | } | |
c04fa44b | 917 | bio->bi_partno = 0; |
52c5e62d | 918 | ret = 0; |
721c7fc7 ID |
919 | out: |
920 | rcu_read_unlock(); | |
74d46992 CH |
921 | return ret; |
922 | } | |
923 | ||
0512a75b KB |
924 | /* |
925 | * Check write append to a zoned block device. | |
926 | */ | |
927 | static inline blk_status_t blk_check_zone_append(struct request_queue *q, | |
928 | struct bio *bio) | |
929 | { | |
930 | sector_t pos = bio->bi_iter.bi_sector; | |
931 | int nr_sectors = bio_sectors(bio); | |
932 | ||
933 | /* Only applicable to zoned block devices */ | |
934 | if (!blk_queue_is_zoned(q)) | |
935 | return BLK_STS_NOTSUPP; | |
936 | ||
937 | /* The bio sector must point to the start of a sequential zone */ | |
938 | if (pos & (blk_queue_zone_sectors(q) - 1) || | |
939 | !blk_queue_zone_is_seq(q, pos)) | |
940 | return BLK_STS_IOERR; | |
941 | ||
942 | /* | |
943 | * Not allowed to cross zone boundaries. Otherwise, the BIO will be | |
944 | * split and could result in non-contiguous sectors being written in | |
945 | * different zones. | |
946 | */ | |
947 | if (nr_sectors > q->limits.chunk_sectors) | |
948 | return BLK_STS_IOERR; | |
949 | ||
950 | /* Make sure the BIO is small enough and will not get split */ | |
951 | if (nr_sectors > q->limits.max_zone_append_sectors) | |
952 | return BLK_STS_IOERR; | |
953 | ||
954 | bio->bi_opf |= REQ_NOMERGE; | |
955 | ||
956 | return BLK_STS_OK; | |
957 | } | |
958 | ||
ed00aabd | 959 | static noinline_for_stack bool submit_bio_checks(struct bio *bio) |
1da177e4 | 960 | { |
833f84e2 | 961 | struct request_queue *q = bio->bi_disk->queue; |
4e4cbee9 | 962 | blk_status_t status = BLK_STS_IOERR; |
1da177e4 LT |
963 | |
964 | might_sleep(); | |
1da177e4 | 965 | |
03a07c92 | 966 | /* |
b0beb280 JA |
967 | * For a REQ_NOWAIT based request, return -EOPNOTSUPP |
968 | * if queue is not a request based queue. | |
03a07c92 | 969 | */ |
b0beb280 JA |
970 | if ((bio->bi_opf & REQ_NOWAIT) && !queue_is_mq(q)) |
971 | goto not_supported; | |
03a07c92 | 972 | |
30abb3a6 | 973 | if (should_fail_bio(bio)) |
5a7bbad2 | 974 | goto end_io; |
2056a782 | 975 | |
52c5e62d CH |
976 | if (bio->bi_partno) { |
977 | if (unlikely(blk_partition_remap(bio))) | |
721c7fc7 ID |
978 | goto end_io; |
979 | } else { | |
52c5e62d CH |
980 | if (unlikely(bio_check_ro(bio, &bio->bi_disk->part0))) |
981 | goto end_io; | |
982 | if (unlikely(bio_check_eod(bio, get_capacity(bio->bi_disk)))) | |
721c7fc7 ID |
983 | goto end_io; |
984 | } | |
2056a782 | 985 | |
5a7bbad2 | 986 | /* |
ed00aabd CH |
987 | * Filter flush bio's early so that bio based drivers without flush |
988 | * support don't have to worry about them. | |
5a7bbad2 | 989 | */ |
f3a8ab7d | 990 | if (op_is_flush(bio->bi_opf) && |
c888a8f9 | 991 | !test_bit(QUEUE_FLAG_WC, &q->queue_flags)) { |
1eff9d32 | 992 | bio->bi_opf &= ~(REQ_PREFLUSH | REQ_FUA); |
e439ab71 | 993 | if (!bio_sectors(bio)) { |
4e4cbee9 | 994 | status = BLK_STS_OK; |
51fd77bd JA |
995 | goto end_io; |
996 | } | |
5a7bbad2 | 997 | } |
5ddfe969 | 998 | |
d04c406f CH |
999 | if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) |
1000 | bio->bi_opf &= ~REQ_HIPRI; | |
1001 | ||
288dab8a CH |
1002 | switch (bio_op(bio)) { |
1003 | case REQ_OP_DISCARD: | |
1004 | if (!blk_queue_discard(q)) | |
1005 | goto not_supported; | |
1006 | break; | |
1007 | case REQ_OP_SECURE_ERASE: | |
1008 | if (!blk_queue_secure_erase(q)) | |
1009 | goto not_supported; | |
1010 | break; | |
1011 | case REQ_OP_WRITE_SAME: | |
74d46992 | 1012 | if (!q->limits.max_write_same_sectors) |
288dab8a | 1013 | goto not_supported; |
58886785 | 1014 | break; |
0512a75b KB |
1015 | case REQ_OP_ZONE_APPEND: |
1016 | status = blk_check_zone_append(q, bio); | |
1017 | if (status != BLK_STS_OK) | |
1018 | goto end_io; | |
1019 | break; | |
2d253440 | 1020 | case REQ_OP_ZONE_RESET: |
6c1b1da5 AJ |
1021 | case REQ_OP_ZONE_OPEN: |
1022 | case REQ_OP_ZONE_CLOSE: | |
1023 | case REQ_OP_ZONE_FINISH: | |
74d46992 | 1024 | if (!blk_queue_is_zoned(q)) |
2d253440 | 1025 | goto not_supported; |
288dab8a | 1026 | break; |
6e33dbf2 CK |
1027 | case REQ_OP_ZONE_RESET_ALL: |
1028 | if (!blk_queue_is_zoned(q) || !blk_queue_zone_resetall(q)) | |
1029 | goto not_supported; | |
1030 | break; | |
a6f0788e | 1031 | case REQ_OP_WRITE_ZEROES: |
74d46992 | 1032 | if (!q->limits.max_write_zeroes_sectors) |
a6f0788e CK |
1033 | goto not_supported; |
1034 | break; | |
288dab8a CH |
1035 | default: |
1036 | break; | |
5a7bbad2 | 1037 | } |
01edede4 | 1038 | |
7f4b35d1 | 1039 | /* |
3e82c348 CH |
1040 | * Various block parts want %current->io_context, so allocate it up |
1041 | * front rather than dealing with lots of pain to allocate it only | |
1042 | * where needed. This may fail and the block layer knows how to live | |
1043 | * with it. | |
7f4b35d1 | 1044 | */ |
3e82c348 CH |
1045 | if (unlikely(!current->io_context)) |
1046 | create_task_io_context(current, GFP_ATOMIC, q->node); | |
7f4b35d1 | 1047 | |
db18a53e CH |
1048 | if (blk_throtl_bio(bio)) { |
1049 | blkcg_bio_issue_init(bio); | |
ae118896 | 1050 | return false; |
db18a53e CH |
1051 | } |
1052 | ||
1053 | blk_cgroup_bio_start(bio); | |
1054 | blkcg_bio_issue_init(bio); | |
27a84d54 | 1055 | |
fbbaf700 N |
1056 | if (!bio_flagged(bio, BIO_TRACE_COMPLETION)) { |
1057 | trace_block_bio_queue(q, bio); | |
1058 | /* Now that enqueuing has been traced, we need to trace | |
1059 | * completion as well. | |
1060 | */ | |
1061 | bio_set_flag(bio, BIO_TRACE_COMPLETION); | |
1062 | } | |
27a84d54 | 1063 | return true; |
a7384677 | 1064 | |
288dab8a | 1065 | not_supported: |
4e4cbee9 | 1066 | status = BLK_STS_NOTSUPP; |
a7384677 | 1067 | end_io: |
4e4cbee9 | 1068 | bio->bi_status = status; |
4246a0b6 | 1069 | bio_endio(bio); |
27a84d54 | 1070 | return false; |
1da177e4 LT |
1071 | } |
1072 | ||
ed00aabd | 1073 | static blk_qc_t __submit_bio(struct bio *bio) |
ac7c5675 | 1074 | { |
c62b37d9 | 1075 | struct gendisk *disk = bio->bi_disk; |
ac7c5675 CH |
1076 | blk_qc_t ret = BLK_QC_T_NONE; |
1077 | ||
1078 | if (blk_crypto_bio_prep(&bio)) { | |
c62b37d9 CH |
1079 | if (!disk->fops->submit_bio) |
1080 | return blk_mq_submit_bio(bio); | |
1081 | ret = disk->fops->submit_bio(bio); | |
ac7c5675 | 1082 | } |
c62b37d9 | 1083 | blk_queue_exit(disk->queue); |
ac7c5675 CH |
1084 | return ret; |
1085 | } | |
1086 | ||
566acf2d CH |
1087 | /* |
1088 | * The loop in this function may be a bit non-obvious, and so deserves some | |
1089 | * explanation: | |
1090 | * | |
1091 | * - Before entering the loop, bio->bi_next is NULL (as all callers ensure | |
1092 | * that), so we have a list with a single bio. | |
1093 | * - We pretend that we have just taken it off a longer list, so we assign | |
1094 | * bio_list to a pointer to the bio_list_on_stack, thus initialising the | |
1095 | * bio_list of new bios to be added. ->submit_bio() may indeed add some more | |
1096 | * bios through a recursive call to submit_bio_noacct. If it did, we find a | |
1097 | * non-NULL value in bio_list and re-enter the loop from the top. | |
1098 | * - In this case we really did just take the bio of the top of the list (no | |
1099 | * pretending) and so remove it from bio_list, and call into ->submit_bio() | |
1100 | * again. | |
1101 | * | |
1102 | * bio_list_on_stack[0] contains bios submitted by the current ->submit_bio. | |
1103 | * bio_list_on_stack[1] contains bios that were submitted before the current | |
1104 | * ->submit_bio_bio, but that haven't been processed yet. | |
1105 | */ | |
1106 | static blk_qc_t __submit_bio_noacct(struct bio *bio) | |
1107 | { | |
1108 | struct bio_list bio_list_on_stack[2]; | |
1109 | blk_qc_t ret = BLK_QC_T_NONE; | |
1110 | ||
1111 | BUG_ON(bio->bi_next); | |
1112 | ||
1113 | bio_list_init(&bio_list_on_stack[0]); | |
1114 | current->bio_list = bio_list_on_stack; | |
1115 | ||
1116 | do { | |
1117 | struct request_queue *q = bio->bi_disk->queue; | |
1118 | struct bio_list lower, same; | |
1119 | ||
1120 | if (unlikely(bio_queue_enter(bio) != 0)) | |
1121 | continue; | |
1122 | ||
1123 | /* | |
1124 | * Create a fresh bio_list for all subordinate requests. | |
1125 | */ | |
1126 | bio_list_on_stack[1] = bio_list_on_stack[0]; | |
1127 | bio_list_init(&bio_list_on_stack[0]); | |
1128 | ||
1129 | ret = __submit_bio(bio); | |
1130 | ||
1131 | /* | |
1132 | * Sort new bios into those for a lower level and those for the | |
1133 | * same level. | |
1134 | */ | |
1135 | bio_list_init(&lower); | |
1136 | bio_list_init(&same); | |
1137 | while ((bio = bio_list_pop(&bio_list_on_stack[0])) != NULL) | |
1138 | if (q == bio->bi_disk->queue) | |
1139 | bio_list_add(&same, bio); | |
1140 | else | |
1141 | bio_list_add(&lower, bio); | |
1142 | ||
1143 | /* | |
1144 | * Now assemble so we handle the lowest level first. | |
1145 | */ | |
1146 | bio_list_merge(&bio_list_on_stack[0], &lower); | |
1147 | bio_list_merge(&bio_list_on_stack[0], &same); | |
1148 | bio_list_merge(&bio_list_on_stack[0], &bio_list_on_stack[1]); | |
1149 | } while ((bio = bio_list_pop(&bio_list_on_stack[0]))); | |
1150 | ||
1151 | current->bio_list = NULL; | |
1152 | return ret; | |
1153 | } | |
1154 | ||
27a84d54 | 1155 | /** |
ed00aabd | 1156 | * submit_bio_noacct - re-submit a bio to the block device layer for I/O |
27a84d54 CH |
1157 | * @bio: The bio describing the location in memory and on the device. |
1158 | * | |
3fdd4086 CH |
1159 | * This is a version of submit_bio() that shall only be used for I/O that is |
1160 | * resubmitted to lower level drivers by stacking block drivers. All file | |
1161 | * systems and other upper level users of the block layer should use | |
1162 | * submit_bio() instead. | |
d89d8796 | 1163 | */ |
ed00aabd | 1164 | blk_qc_t submit_bio_noacct(struct bio *bio) |
d89d8796 | 1165 | { |
ed00aabd | 1166 | if (!submit_bio_checks(bio)) |
566acf2d | 1167 | return BLK_QC_T_NONE; |
27a84d54 CH |
1168 | |
1169 | /* | |
566acf2d CH |
1170 | * We only want one ->submit_bio to be active at a time, else stack |
1171 | * usage with stacked devices could be a problem. Use current->bio_list | |
1172 | * to collect a list of requests submited by a ->submit_bio method while | |
1173 | * it is active, and then process them after it returned. | |
27a84d54 | 1174 | */ |
bddd87c7 | 1175 | if (current->bio_list) { |
f5fe1b51 | 1176 | bio_list_add(¤t->bio_list[0], bio); |
566acf2d | 1177 | return BLK_QC_T_NONE; |
d89d8796 | 1178 | } |
27a84d54 | 1179 | |
566acf2d | 1180 | return __submit_bio_noacct(bio); |
d89d8796 | 1181 | } |
ed00aabd | 1182 | EXPORT_SYMBOL(submit_bio_noacct); |
1da177e4 | 1183 | |
f421e1d9 CH |
1184 | /** |
1185 | * direct_make_request - hand a buffer directly to its device driver for I/O | |
1186 | * @bio: The bio describing the location in memory and on the device. | |
1187 | * | |
ed00aabd | 1188 | * This function behaves like submit_bio_noacct(), but does not protect |
f421e1d9 | 1189 | * against recursion. Must only be used if the called driver is known |
8cf7961d | 1190 | * to be blk-mq based. |
f421e1d9 CH |
1191 | */ |
1192 | blk_qc_t direct_make_request(struct bio *bio) | |
1193 | { | |
c62b37d9 | 1194 | struct gendisk *disk = bio->bi_disk; |
f421e1d9 | 1195 | |
c62b37d9 | 1196 | if (WARN_ON_ONCE(!disk->queue->mq_ops)) { |
accea322 | 1197 | bio_io_error(bio); |
f421e1d9 | 1198 | return BLK_QC_T_NONE; |
f421e1d9 | 1199 | } |
ed00aabd | 1200 | if (!submit_bio_checks(bio)) |
f421e1d9 | 1201 | return BLK_QC_T_NONE; |
accea322 CH |
1202 | if (unlikely(bio_queue_enter(bio))) |
1203 | return BLK_QC_T_NONE; | |
ac7c5675 | 1204 | if (!blk_crypto_bio_prep(&bio)) { |
c62b37d9 | 1205 | blk_queue_exit(disk->queue); |
f421e1d9 CH |
1206 | return BLK_QC_T_NONE; |
1207 | } | |
c62b37d9 | 1208 | return blk_mq_submit_bio(bio); |
f421e1d9 CH |
1209 | } |
1210 | EXPORT_SYMBOL_GPL(direct_make_request); | |
1211 | ||
1da177e4 | 1212 | /** |
710027a4 | 1213 | * submit_bio - submit a bio to the block device layer for I/O |
1da177e4 LT |
1214 | * @bio: The &struct bio which describes the I/O |
1215 | * | |
3fdd4086 CH |
1216 | * submit_bio() is used to submit I/O requests to block devices. It is passed a |
1217 | * fully set up &struct bio that describes the I/O that needs to be done. The | |
1218 | * bio will be send to the device described by the bi_disk and bi_partno fields. | |
1da177e4 | 1219 | * |
3fdd4086 CH |
1220 | * The success/failure status of the request, along with notification of |
1221 | * completion, is delivered asynchronously through the ->bi_end_io() callback | |
1222 | * in @bio. The bio must NOT be touched by thecaller until ->bi_end_io() has | |
1223 | * been called. | |
1da177e4 | 1224 | */ |
4e49ea4a | 1225 | blk_qc_t submit_bio(struct bio *bio) |
1da177e4 | 1226 | { |
d3f77dfd TH |
1227 | if (blkcg_punt_bio_submit(bio)) |
1228 | return BLK_QC_T_NONE; | |
1229 | ||
bf2de6f5 JA |
1230 | /* |
1231 | * If it's a regular read/write or a barrier with data attached, | |
1232 | * go through the normal accounting stuff before submission. | |
1233 | */ | |
e2a60da7 | 1234 | if (bio_has_data(bio)) { |
4363ac7c MP |
1235 | unsigned int count; |
1236 | ||
95fe6c1a | 1237 | if (unlikely(bio_op(bio) == REQ_OP_WRITE_SAME)) |
7c5a0dcf | 1238 | count = queue_logical_block_size(bio->bi_disk->queue) >> 9; |
4363ac7c MP |
1239 | else |
1240 | count = bio_sectors(bio); | |
1241 | ||
a8ebb056 | 1242 | if (op_is_write(bio_op(bio))) { |
bf2de6f5 JA |
1243 | count_vm_events(PGPGOUT, count); |
1244 | } else { | |
4f024f37 | 1245 | task_io_account_read(bio->bi_iter.bi_size); |
bf2de6f5 JA |
1246 | count_vm_events(PGPGIN, count); |
1247 | } | |
1248 | ||
1249 | if (unlikely(block_dump)) { | |
1250 | char b[BDEVNAME_SIZE]; | |
8dcbdc74 | 1251 | printk(KERN_DEBUG "%s(%d): %s block %Lu on %s (%u sectors)\n", |
ba25f9dc | 1252 | current->comm, task_pid_nr(current), |
a8ebb056 | 1253 | op_is_write(bio_op(bio)) ? "WRITE" : "READ", |
4f024f37 | 1254 | (unsigned long long)bio->bi_iter.bi_sector, |
74d46992 | 1255 | bio_devname(bio, b), count); |
bf2de6f5 | 1256 | } |
1da177e4 LT |
1257 | } |
1258 | ||
b8e24a93 | 1259 | /* |
760f83ea CH |
1260 | * If we're reading data that is part of the userspace workingset, count |
1261 | * submission time as memory stall. When the device is congested, or | |
1262 | * the submitting cgroup IO-throttled, submission can be a significant | |
1263 | * part of overall IO time. | |
b8e24a93 | 1264 | */ |
760f83ea CH |
1265 | if (unlikely(bio_op(bio) == REQ_OP_READ && |
1266 | bio_flagged(bio, BIO_WORKINGSET))) { | |
1267 | unsigned long pflags; | |
1268 | blk_qc_t ret; | |
b8e24a93 | 1269 | |
760f83ea | 1270 | psi_memstall_enter(&pflags); |
ed00aabd | 1271 | ret = submit_bio_noacct(bio); |
b8e24a93 JW |
1272 | psi_memstall_leave(&pflags); |
1273 | ||
760f83ea CH |
1274 | return ret; |
1275 | } | |
1276 | ||
ed00aabd | 1277 | return submit_bio_noacct(bio); |
1da177e4 | 1278 | } |
1da177e4 LT |
1279 | EXPORT_SYMBOL(submit_bio); |
1280 | ||
82124d60 | 1281 | /** |
bf4e6b4e | 1282 | * blk_cloned_rq_check_limits - Helper function to check a cloned request |
0d720318 | 1283 | * for the new queue limits |
82124d60 KU |
1284 | * @q: the queue |
1285 | * @rq: the request being checked | |
1286 | * | |
1287 | * Description: | |
1288 | * @rq may have been made based on weaker limitations of upper-level queues | |
1289 | * in request stacking drivers, and it may violate the limitation of @q. | |
1290 | * Since the block layer and the underlying device driver trust @rq | |
1291 | * after it is inserted to @q, it should be checked against @q before | |
1292 | * the insertion using this generic function. | |
1293 | * | |
82124d60 | 1294 | * Request stacking drivers like request-based dm may change the queue |
bf4e6b4e HR |
1295 | * limits when retrying requests on other queues. Those requests need |
1296 | * to be checked against the new queue limits again during dispatch. | |
82124d60 | 1297 | */ |
bf4e6b4e HR |
1298 | static int blk_cloned_rq_check_limits(struct request_queue *q, |
1299 | struct request *rq) | |
82124d60 | 1300 | { |
8fe0d473 | 1301 | if (blk_rq_sectors(rq) > blk_queue_get_max_sectors(q, req_op(rq))) { |
61939b12 JP |
1302 | printk(KERN_ERR "%s: over max size limit. (%u > %u)\n", |
1303 | __func__, blk_rq_sectors(rq), | |
1304 | blk_queue_get_max_sectors(q, req_op(rq))); | |
82124d60 KU |
1305 | return -EIO; |
1306 | } | |
1307 | ||
1308 | /* | |
1309 | * queue's settings related to segment counting like q->bounce_pfn | |
1310 | * may differ from that of other stacking queues. | |
1311 | * Recalculate it to check the request correctly on this queue's | |
1312 | * limitation. | |
1313 | */ | |
e9cd19c0 | 1314 | rq->nr_phys_segments = blk_recalc_rq_segments(rq); |
8a78362c | 1315 | if (rq->nr_phys_segments > queue_max_segments(q)) { |
61939b12 JP |
1316 | printk(KERN_ERR "%s: over max segments limit. (%hu > %hu)\n", |
1317 | __func__, rq->nr_phys_segments, queue_max_segments(q)); | |
82124d60 KU |
1318 | return -EIO; |
1319 | } | |
1320 | ||
1321 | return 0; | |
1322 | } | |
82124d60 KU |
1323 | |
1324 | /** | |
1325 | * blk_insert_cloned_request - Helper for stacking drivers to submit a request | |
1326 | * @q: the queue to submit the request | |
1327 | * @rq: the request being queued | |
1328 | */ | |
2a842aca | 1329 | blk_status_t blk_insert_cloned_request(struct request_queue *q, struct request *rq) |
82124d60 | 1330 | { |
bf4e6b4e | 1331 | if (blk_cloned_rq_check_limits(q, rq)) |
2a842aca | 1332 | return BLK_STS_IOERR; |
82124d60 | 1333 | |
b2c9cd37 AM |
1334 | if (rq->rq_disk && |
1335 | should_fail_request(&rq->rq_disk->part0, blk_rq_bytes(rq))) | |
2a842aca | 1336 | return BLK_STS_IOERR; |
82124d60 | 1337 | |
a892c8d5 ST |
1338 | if (blk_crypto_insert_cloned_request(rq)) |
1339 | return BLK_STS_IOERR; | |
1340 | ||
a1ce35fa | 1341 | if (blk_queue_io_stat(q)) |
b5af37ab | 1342 | blk_account_io_start(rq); |
82124d60 KU |
1343 | |
1344 | /* | |
a1ce35fa JA |
1345 | * Since we have a scheduler attached on the top device, |
1346 | * bypass a potential scheduler on the bottom device for | |
1347 | * insert. | |
82124d60 | 1348 | */ |
fd9c40f6 | 1349 | return blk_mq_request_issue_directly(rq, true); |
82124d60 KU |
1350 | } |
1351 | EXPORT_SYMBOL_GPL(blk_insert_cloned_request); | |
1352 | ||
80a761fd TH |
1353 | /** |
1354 | * blk_rq_err_bytes - determine number of bytes till the next failure boundary | |
1355 | * @rq: request to examine | |
1356 | * | |
1357 | * Description: | |
1358 | * A request could be merge of IOs which require different failure | |
1359 | * handling. This function determines the number of bytes which | |
1360 | * can be failed from the beginning of the request without | |
1361 | * crossing into area which need to be retried further. | |
1362 | * | |
1363 | * Return: | |
1364 | * The number of bytes to fail. | |
80a761fd TH |
1365 | */ |
1366 | unsigned int blk_rq_err_bytes(const struct request *rq) | |
1367 | { | |
1368 | unsigned int ff = rq->cmd_flags & REQ_FAILFAST_MASK; | |
1369 | unsigned int bytes = 0; | |
1370 | struct bio *bio; | |
1371 | ||
e8064021 | 1372 | if (!(rq->rq_flags & RQF_MIXED_MERGE)) |
80a761fd TH |
1373 | return blk_rq_bytes(rq); |
1374 | ||
1375 | /* | |
1376 | * Currently the only 'mixing' which can happen is between | |
1377 | * different fastfail types. We can safely fail portions | |
1378 | * which have all the failfast bits that the first one has - | |
1379 | * the ones which are at least as eager to fail as the first | |
1380 | * one. | |
1381 | */ | |
1382 | for (bio = rq->bio; bio; bio = bio->bi_next) { | |
1eff9d32 | 1383 | if ((bio->bi_opf & ff) != ff) |
80a761fd | 1384 | break; |
4f024f37 | 1385 | bytes += bio->bi_iter.bi_size; |
80a761fd TH |
1386 | } |
1387 | ||
1388 | /* this could lead to infinite loop */ | |
1389 | BUG_ON(blk_rq_bytes(rq) && !bytes); | |
1390 | return bytes; | |
1391 | } | |
1392 | EXPORT_SYMBOL_GPL(blk_rq_err_bytes); | |
1393 | ||
9123bf6f CH |
1394 | static void update_io_ticks(struct hd_struct *part, unsigned long now, bool end) |
1395 | { | |
1396 | unsigned long stamp; | |
1397 | again: | |
1398 | stamp = READ_ONCE(part->stamp); | |
1399 | if (unlikely(stamp != now)) { | |
1400 | if (likely(cmpxchg(&part->stamp, stamp, now) == stamp)) | |
1401 | __part_stat_add(part, io_ticks, end ? now - stamp : 1); | |
1402 | } | |
1403 | if (part->partno) { | |
1404 | part = &part_to_disk(part)->part0; | |
1405 | goto again; | |
1406 | } | |
1407 | } | |
1408 | ||
f1394b79 | 1409 | static void blk_account_io_completion(struct request *req, unsigned int bytes) |
bc58ba94 | 1410 | { |
ecb6186c | 1411 | if (req->part && blk_do_io_stat(req)) { |
ddcf35d3 | 1412 | const int sgrp = op_stat_group(req_op(req)); |
bc58ba94 | 1413 | struct hd_struct *part; |
bc58ba94 | 1414 | |
112f158f | 1415 | part_stat_lock(); |
09e099d4 | 1416 | part = req->part; |
112f158f | 1417 | part_stat_add(part, sectors[sgrp], bytes >> 9); |
bc58ba94 JA |
1418 | part_stat_unlock(); |
1419 | } | |
1420 | } | |
1421 | ||
522a7775 | 1422 | void blk_account_io_done(struct request *req, u64 now) |
bc58ba94 | 1423 | { |
bc58ba94 | 1424 | /* |
dd4c133f TH |
1425 | * Account IO completion. flush_rq isn't accounted as a |
1426 | * normal IO on queueing nor completion. Accounting the | |
1427 | * containing request is enough. | |
bc58ba94 | 1428 | */ |
ecb6186c LG |
1429 | if (req->part && blk_do_io_stat(req) && |
1430 | !(req->rq_flags & RQF_FLUSH_SEQ)) { | |
ddcf35d3 | 1431 | const int sgrp = op_stat_group(req_op(req)); |
bc58ba94 | 1432 | struct hd_struct *part; |
bc58ba94 | 1433 | |
112f158f | 1434 | part_stat_lock(); |
09e099d4 | 1435 | part = req->part; |
bc58ba94 | 1436 | |
2b8bd423 | 1437 | update_io_ticks(part, jiffies, true); |
112f158f MS |
1438 | part_stat_inc(part, ios[sgrp]); |
1439 | part_stat_add(part, nsecs[sgrp], now - req->start_time_ns); | |
524f9ffd | 1440 | part_stat_unlock(); |
bc58ba94 | 1441 | |
6c23a968 | 1442 | hd_struct_put(part); |
bc58ba94 JA |
1443 | } |
1444 | } | |
1445 | ||
b5af37ab | 1446 | void blk_account_io_start(struct request *rq) |
320ae51f | 1447 | { |
320ae51f JA |
1448 | if (!blk_do_io_stat(rq)) |
1449 | return; | |
1450 | ||
b5af37ab | 1451 | rq->part = disk_map_sector_rcu(rq->rq_disk, blk_rq_pos(rq)); |
524f9ffd | 1452 | |
112f158f | 1453 | part_stat_lock(); |
76268f3a | 1454 | update_io_ticks(rq->part, jiffies, false); |
320ae51f JA |
1455 | part_stat_unlock(); |
1456 | } | |
320ae51f | 1457 | |
956d510e CH |
1458 | unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors, |
1459 | unsigned int op) | |
1460 | { | |
1461 | struct hd_struct *part = &disk->part0; | |
1462 | const int sgrp = op_stat_group(op); | |
1463 | unsigned long now = READ_ONCE(jiffies); | |
1464 | ||
1465 | part_stat_lock(); | |
1466 | update_io_ticks(part, now, false); | |
1467 | part_stat_inc(part, ios[sgrp]); | |
1468 | part_stat_add(part, sectors[sgrp], sectors); | |
1469 | part_stat_local_inc(part, in_flight[op_is_write(op)]); | |
1470 | part_stat_unlock(); | |
320ae51f | 1471 | |
956d510e CH |
1472 | return now; |
1473 | } | |
1474 | EXPORT_SYMBOL(disk_start_io_acct); | |
1475 | ||
1476 | void disk_end_io_acct(struct gendisk *disk, unsigned int op, | |
1477 | unsigned long start_time) | |
1478 | { | |
1479 | struct hd_struct *part = &disk->part0; | |
1480 | const int sgrp = op_stat_group(op); | |
1481 | unsigned long now = READ_ONCE(jiffies); | |
1482 | unsigned long duration = now - start_time; | |
5b18b5a7 | 1483 | |
956d510e CH |
1484 | part_stat_lock(); |
1485 | update_io_ticks(part, now, true); | |
1486 | part_stat_add(part, nsecs[sgrp], jiffies_to_nsecs(duration)); | |
1487 | part_stat_local_dec(part, in_flight[op_is_write(op)]); | |
320ae51f JA |
1488 | part_stat_unlock(); |
1489 | } | |
956d510e | 1490 | EXPORT_SYMBOL(disk_end_io_acct); |
320ae51f | 1491 | |
ef71de8b CH |
1492 | /* |
1493 | * Steal bios from a request and add them to a bio list. | |
1494 | * The request must not have been partially completed before. | |
1495 | */ | |
1496 | void blk_steal_bios(struct bio_list *list, struct request *rq) | |
1497 | { | |
1498 | if (rq->bio) { | |
1499 | if (list->tail) | |
1500 | list->tail->bi_next = rq->bio; | |
1501 | else | |
1502 | list->head = rq->bio; | |
1503 | list->tail = rq->biotail; | |
1504 | ||
1505 | rq->bio = NULL; | |
1506 | rq->biotail = NULL; | |
1507 | } | |
1508 | ||
1509 | rq->__data_len = 0; | |
1510 | } | |
1511 | EXPORT_SYMBOL_GPL(blk_steal_bios); | |
1512 | ||
3bcddeac | 1513 | /** |
2e60e022 | 1514 | * blk_update_request - Special helper function for request stacking drivers |
8ebf9756 | 1515 | * @req: the request being processed |
2a842aca | 1516 | * @error: block status code |
8ebf9756 | 1517 | * @nr_bytes: number of bytes to complete @req |
3bcddeac KU |
1518 | * |
1519 | * Description: | |
8ebf9756 RD |
1520 | * Ends I/O on a number of bytes attached to @req, but doesn't complete |
1521 | * the request structure even if @req doesn't have leftover. | |
1522 | * If @req has leftover, sets it up for the next range of segments. | |
2e60e022 TH |
1523 | * |
1524 | * This special helper function is only for request stacking drivers | |
1525 | * (e.g. request-based dm) so that they can handle partial completion. | |
3a211b71 | 1526 | * Actual device drivers should use blk_mq_end_request instead. |
2e60e022 TH |
1527 | * |
1528 | * Passing the result of blk_rq_bytes() as @nr_bytes guarantees | |
1529 | * %false return from this function. | |
3bcddeac | 1530 | * |
1954e9a9 BVA |
1531 | * Note: |
1532 | * The RQF_SPECIAL_PAYLOAD flag is ignored on purpose in both | |
1533 | * blk_rq_bytes() and in blk_update_request(). | |
1534 | * | |
3bcddeac | 1535 | * Return: |
2e60e022 TH |
1536 | * %false - this request doesn't have any more data |
1537 | * %true - this request has more data | |
3bcddeac | 1538 | **/ |
2a842aca CH |
1539 | bool blk_update_request(struct request *req, blk_status_t error, |
1540 | unsigned int nr_bytes) | |
1da177e4 | 1541 | { |
f79ea416 | 1542 | int total_bytes; |
1da177e4 | 1543 | |
2a842aca | 1544 | trace_block_rq_complete(req, blk_status_to_errno(error), nr_bytes); |
4a0efdc9 | 1545 | |
2e60e022 TH |
1546 | if (!req->bio) |
1547 | return false; | |
1548 | ||
54d4e6ab MG |
1549 | #ifdef CONFIG_BLK_DEV_INTEGRITY |
1550 | if (blk_integrity_rq(req) && req_op(req) == REQ_OP_READ && | |
1551 | error == BLK_STS_OK) | |
1552 | req->q->integrity.profile->complete_fn(req, nr_bytes); | |
1553 | #endif | |
1554 | ||
2a842aca CH |
1555 | if (unlikely(error && !blk_rq_is_passthrough(req) && |
1556 | !(req->rq_flags & RQF_QUIET))) | |
178cc590 | 1557 | print_req_error(req, error, __func__); |
1da177e4 | 1558 | |
bc58ba94 | 1559 | blk_account_io_completion(req, nr_bytes); |
d72d904a | 1560 | |
f79ea416 KO |
1561 | total_bytes = 0; |
1562 | while (req->bio) { | |
1563 | struct bio *bio = req->bio; | |
4f024f37 | 1564 | unsigned bio_bytes = min(bio->bi_iter.bi_size, nr_bytes); |
1da177e4 | 1565 | |
9c24c10a | 1566 | if (bio_bytes == bio->bi_iter.bi_size) |
1da177e4 | 1567 | req->bio = bio->bi_next; |
1da177e4 | 1568 | |
fbbaf700 N |
1569 | /* Completion has already been traced */ |
1570 | bio_clear_flag(bio, BIO_TRACE_COMPLETION); | |
f79ea416 | 1571 | req_bio_endio(req, bio, bio_bytes, error); |
1da177e4 | 1572 | |
f79ea416 KO |
1573 | total_bytes += bio_bytes; |
1574 | nr_bytes -= bio_bytes; | |
1da177e4 | 1575 | |
f79ea416 KO |
1576 | if (!nr_bytes) |
1577 | break; | |
1da177e4 LT |
1578 | } |
1579 | ||
1580 | /* | |
1581 | * completely done | |
1582 | */ | |
2e60e022 TH |
1583 | if (!req->bio) { |
1584 | /* | |
1585 | * Reset counters so that the request stacking driver | |
1586 | * can find how many bytes remain in the request | |
1587 | * later. | |
1588 | */ | |
a2dec7b3 | 1589 | req->__data_len = 0; |
2e60e022 TH |
1590 | return false; |
1591 | } | |
1da177e4 | 1592 | |
a2dec7b3 | 1593 | req->__data_len -= total_bytes; |
2e46e8b2 TH |
1594 | |
1595 | /* update sector only for requests with clear definition of sector */ | |
57292b58 | 1596 | if (!blk_rq_is_passthrough(req)) |
a2dec7b3 | 1597 | req->__sector += total_bytes >> 9; |
2e46e8b2 | 1598 | |
80a761fd | 1599 | /* mixed attributes always follow the first bio */ |
e8064021 | 1600 | if (req->rq_flags & RQF_MIXED_MERGE) { |
80a761fd | 1601 | req->cmd_flags &= ~REQ_FAILFAST_MASK; |
1eff9d32 | 1602 | req->cmd_flags |= req->bio->bi_opf & REQ_FAILFAST_MASK; |
80a761fd TH |
1603 | } |
1604 | ||
ed6565e7 CH |
1605 | if (!(req->rq_flags & RQF_SPECIAL_PAYLOAD)) { |
1606 | /* | |
1607 | * If total number of sectors is less than the first segment | |
1608 | * size, something has gone terribly wrong. | |
1609 | */ | |
1610 | if (blk_rq_bytes(req) < blk_rq_cur_bytes(req)) { | |
1611 | blk_dump_rq_flags(req, "request botched"); | |
1612 | req->__data_len = blk_rq_cur_bytes(req); | |
1613 | } | |
2e46e8b2 | 1614 | |
ed6565e7 | 1615 | /* recalculate the number of segments */ |
e9cd19c0 | 1616 | req->nr_phys_segments = blk_recalc_rq_segments(req); |
ed6565e7 | 1617 | } |
2e46e8b2 | 1618 | |
2e60e022 | 1619 | return true; |
1da177e4 | 1620 | } |
2e60e022 | 1621 | EXPORT_SYMBOL_GPL(blk_update_request); |
1da177e4 | 1622 | |
2d4dc890 IL |
1623 | #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE |
1624 | /** | |
1625 | * rq_flush_dcache_pages - Helper function to flush all pages in a request | |
1626 | * @rq: the request to be flushed | |
1627 | * | |
1628 | * Description: | |
1629 | * Flush all pages in @rq. | |
1630 | */ | |
1631 | void rq_flush_dcache_pages(struct request *rq) | |
1632 | { | |
1633 | struct req_iterator iter; | |
7988613b | 1634 | struct bio_vec bvec; |
2d4dc890 IL |
1635 | |
1636 | rq_for_each_segment(bvec, rq, iter) | |
7988613b | 1637 | flush_dcache_page(bvec.bv_page); |
2d4dc890 IL |
1638 | } |
1639 | EXPORT_SYMBOL_GPL(rq_flush_dcache_pages); | |
1640 | #endif | |
1641 | ||
ef9e3fac KU |
1642 | /** |
1643 | * blk_lld_busy - Check if underlying low-level drivers of a device are busy | |
1644 | * @q : the queue of the device being checked | |
1645 | * | |
1646 | * Description: | |
1647 | * Check if underlying low-level drivers of a device are busy. | |
1648 | * If the drivers want to export their busy state, they must set own | |
1649 | * exporting function using blk_queue_lld_busy() first. | |
1650 | * | |
1651 | * Basically, this function is used only by request stacking drivers | |
1652 | * to stop dispatching requests to underlying devices when underlying | |
1653 | * devices are busy. This behavior helps more I/O merging on the queue | |
1654 | * of the request stacking driver and prevents I/O throughput regression | |
1655 | * on burst I/O load. | |
1656 | * | |
1657 | * Return: | |
1658 | * 0 - Not busy (The request stacking driver should dispatch request) | |
1659 | * 1 - Busy (The request stacking driver should stop dispatching request) | |
1660 | */ | |
1661 | int blk_lld_busy(struct request_queue *q) | |
1662 | { | |
344e9ffc | 1663 | if (queue_is_mq(q) && q->mq_ops->busy) |
9ba20527 | 1664 | return q->mq_ops->busy(q); |
ef9e3fac KU |
1665 | |
1666 | return 0; | |
1667 | } | |
1668 | EXPORT_SYMBOL_GPL(blk_lld_busy); | |
1669 | ||
78d8e58a MS |
1670 | /** |
1671 | * blk_rq_unprep_clone - Helper function to free all bios in a cloned request | |
1672 | * @rq: the clone request to be cleaned up | |
1673 | * | |
1674 | * Description: | |
1675 | * Free all bios in @rq for a cloned request. | |
1676 | */ | |
1677 | void blk_rq_unprep_clone(struct request *rq) | |
1678 | { | |
1679 | struct bio *bio; | |
1680 | ||
1681 | while ((bio = rq->bio) != NULL) { | |
1682 | rq->bio = bio->bi_next; | |
1683 | ||
1684 | bio_put(bio); | |
1685 | } | |
1686 | } | |
1687 | EXPORT_SYMBOL_GPL(blk_rq_unprep_clone); | |
1688 | ||
78d8e58a MS |
1689 | /** |
1690 | * blk_rq_prep_clone - Helper function to setup clone request | |
1691 | * @rq: the request to be setup | |
1692 | * @rq_src: original request to be cloned | |
1693 | * @bs: bio_set that bios for clone are allocated from | |
1694 | * @gfp_mask: memory allocation mask for bio | |
1695 | * @bio_ctr: setup function to be called for each clone bio. | |
1696 | * Returns %0 for success, non %0 for failure. | |
1697 | * @data: private data to be passed to @bio_ctr | |
1698 | * | |
1699 | * Description: | |
1700 | * Clones bios in @rq_src to @rq, and copies attributes of @rq_src to @rq. | |
78d8e58a MS |
1701 | * Also, pages which the original bios are pointing to are not copied |
1702 | * and the cloned bios just point same pages. | |
1703 | * So cloned bios must be completed before original bios, which means | |
1704 | * the caller must complete @rq before @rq_src. | |
1705 | */ | |
1706 | int blk_rq_prep_clone(struct request *rq, struct request *rq_src, | |
1707 | struct bio_set *bs, gfp_t gfp_mask, | |
1708 | int (*bio_ctr)(struct bio *, struct bio *, void *), | |
1709 | void *data) | |
1710 | { | |
1711 | struct bio *bio, *bio_src; | |
1712 | ||
1713 | if (!bs) | |
f4f8154a | 1714 | bs = &fs_bio_set; |
78d8e58a MS |
1715 | |
1716 | __rq_for_each_bio(bio_src, rq_src) { | |
1717 | bio = bio_clone_fast(bio_src, gfp_mask, bs); | |
1718 | if (!bio) | |
1719 | goto free_and_out; | |
1720 | ||
1721 | if (bio_ctr && bio_ctr(bio, bio_src, data)) | |
1722 | goto free_and_out; | |
1723 | ||
1724 | if (rq->bio) { | |
1725 | rq->biotail->bi_next = bio; | |
1726 | rq->biotail = bio; | |
1727 | } else | |
1728 | rq->bio = rq->biotail = bio; | |
1729 | } | |
1730 | ||
361301a2 GJ |
1731 | /* Copy attributes of the original request to the clone request. */ |
1732 | rq->__sector = blk_rq_pos(rq_src); | |
1733 | rq->__data_len = blk_rq_bytes(rq_src); | |
1734 | if (rq_src->rq_flags & RQF_SPECIAL_PAYLOAD) { | |
1735 | rq->rq_flags |= RQF_SPECIAL_PAYLOAD; | |
1736 | rq->special_vec = rq_src->special_vec; | |
1737 | } | |
1738 | rq->nr_phys_segments = rq_src->nr_phys_segments; | |
1739 | rq->ioprio = rq_src->ioprio; | |
78d8e58a | 1740 | |
a892c8d5 ST |
1741 | if (rq->bio) |
1742 | blk_crypto_rq_bio_prep(rq, rq->bio, gfp_mask); | |
78d8e58a MS |
1743 | |
1744 | return 0; | |
1745 | ||
1746 | free_and_out: | |
1747 | if (bio) | |
1748 | bio_put(bio); | |
1749 | blk_rq_unprep_clone(rq); | |
1750 | ||
1751 | return -ENOMEM; | |
b0fd271d KU |
1752 | } |
1753 | EXPORT_SYMBOL_GPL(blk_rq_prep_clone); | |
1754 | ||
59c3d45e | 1755 | int kblockd_schedule_work(struct work_struct *work) |
1da177e4 LT |
1756 | { |
1757 | return queue_work(kblockd_workqueue, work); | |
1758 | } | |
1da177e4 LT |
1759 | EXPORT_SYMBOL(kblockd_schedule_work); |
1760 | ||
818cd1cb JA |
1761 | int kblockd_mod_delayed_work_on(int cpu, struct delayed_work *dwork, |
1762 | unsigned long delay) | |
1763 | { | |
1764 | return mod_delayed_work_on(cpu, kblockd_workqueue, dwork, delay); | |
1765 | } | |
1766 | EXPORT_SYMBOL(kblockd_mod_delayed_work_on); | |
1767 | ||
75df7136 SJ |
1768 | /** |
1769 | * blk_start_plug - initialize blk_plug and track it inside the task_struct | |
1770 | * @plug: The &struct blk_plug that needs to be initialized | |
1771 | * | |
1772 | * Description: | |
40405851 JM |
1773 | * blk_start_plug() indicates to the block layer an intent by the caller |
1774 | * to submit multiple I/O requests in a batch. The block layer may use | |
1775 | * this hint to defer submitting I/Os from the caller until blk_finish_plug() | |
1776 | * is called. However, the block layer may choose to submit requests | |
1777 | * before a call to blk_finish_plug() if the number of queued I/Os | |
1778 | * exceeds %BLK_MAX_REQUEST_COUNT, or if the size of the I/O is larger than | |
1779 | * %BLK_PLUG_FLUSH_SIZE. The queued I/Os may also be submitted early if | |
1780 | * the task schedules (see below). | |
1781 | * | |
75df7136 SJ |
1782 | * Tracking blk_plug inside the task_struct will help with auto-flushing the |
1783 | * pending I/O should the task end up blocking between blk_start_plug() and | |
1784 | * blk_finish_plug(). This is important from a performance perspective, but | |
1785 | * also ensures that we don't deadlock. For instance, if the task is blocking | |
1786 | * for a memory allocation, memory reclaim could end up wanting to free a | |
1787 | * page belonging to that request that is currently residing in our private | |
1788 | * plug. By flushing the pending I/O when the process goes to sleep, we avoid | |
1789 | * this kind of deadlock. | |
1790 | */ | |
73c10101 JA |
1791 | void blk_start_plug(struct blk_plug *plug) |
1792 | { | |
1793 | struct task_struct *tsk = current; | |
1794 | ||
dd6cf3e1 SL |
1795 | /* |
1796 | * If this is a nested plug, don't actually assign it. | |
1797 | */ | |
1798 | if (tsk->plug) | |
1799 | return; | |
1800 | ||
320ae51f | 1801 | INIT_LIST_HEAD(&plug->mq_list); |
048c9374 | 1802 | INIT_LIST_HEAD(&plug->cb_list); |
5f0ed774 | 1803 | plug->rq_count = 0; |
ce5b009c | 1804 | plug->multiple_queues = false; |
5f0ed774 | 1805 | |
73c10101 | 1806 | /* |
dd6cf3e1 SL |
1807 | * Store ordering should not be needed here, since a potential |
1808 | * preempt will imply a full memory barrier | |
73c10101 | 1809 | */ |
dd6cf3e1 | 1810 | tsk->plug = plug; |
73c10101 JA |
1811 | } |
1812 | EXPORT_SYMBOL(blk_start_plug); | |
1813 | ||
74018dc3 | 1814 | static void flush_plug_callbacks(struct blk_plug *plug, bool from_schedule) |
048c9374 N |
1815 | { |
1816 | LIST_HEAD(callbacks); | |
1817 | ||
2a7d5559 SL |
1818 | while (!list_empty(&plug->cb_list)) { |
1819 | list_splice_init(&plug->cb_list, &callbacks); | |
048c9374 | 1820 | |
2a7d5559 SL |
1821 | while (!list_empty(&callbacks)) { |
1822 | struct blk_plug_cb *cb = list_first_entry(&callbacks, | |
048c9374 N |
1823 | struct blk_plug_cb, |
1824 | list); | |
2a7d5559 | 1825 | list_del(&cb->list); |
74018dc3 | 1826 | cb->callback(cb, from_schedule); |
2a7d5559 | 1827 | } |
048c9374 N |
1828 | } |
1829 | } | |
1830 | ||
9cbb1750 N |
1831 | struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, void *data, |
1832 | int size) | |
1833 | { | |
1834 | struct blk_plug *plug = current->plug; | |
1835 | struct blk_plug_cb *cb; | |
1836 | ||
1837 | if (!plug) | |
1838 | return NULL; | |
1839 | ||
1840 | list_for_each_entry(cb, &plug->cb_list, list) | |
1841 | if (cb->callback == unplug && cb->data == data) | |
1842 | return cb; | |
1843 | ||
1844 | /* Not currently on the callback list */ | |
1845 | BUG_ON(size < sizeof(*cb)); | |
1846 | cb = kzalloc(size, GFP_ATOMIC); | |
1847 | if (cb) { | |
1848 | cb->data = data; | |
1849 | cb->callback = unplug; | |
1850 | list_add(&cb->list, &plug->cb_list); | |
1851 | } | |
1852 | return cb; | |
1853 | } | |
1854 | EXPORT_SYMBOL(blk_check_plugged); | |
1855 | ||
49cac01e | 1856 | void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule) |
73c10101 | 1857 | { |
74018dc3 | 1858 | flush_plug_callbacks(plug, from_schedule); |
320ae51f JA |
1859 | |
1860 | if (!list_empty(&plug->mq_list)) | |
1861 | blk_mq_flush_plug_list(plug, from_schedule); | |
73c10101 | 1862 | } |
73c10101 | 1863 | |
40405851 JM |
1864 | /** |
1865 | * blk_finish_plug - mark the end of a batch of submitted I/O | |
1866 | * @plug: The &struct blk_plug passed to blk_start_plug() | |
1867 | * | |
1868 | * Description: | |
1869 | * Indicate that a batch of I/O submissions is complete. This function | |
1870 | * must be paired with an initial call to blk_start_plug(). The intent | |
1871 | * is to allow the block layer to optimize I/O submission. See the | |
1872 | * documentation for blk_start_plug() for more information. | |
1873 | */ | |
73c10101 JA |
1874 | void blk_finish_plug(struct blk_plug *plug) |
1875 | { | |
dd6cf3e1 SL |
1876 | if (plug != current->plug) |
1877 | return; | |
f6603783 | 1878 | blk_flush_plug_list(plug, false); |
73c10101 | 1879 | |
dd6cf3e1 | 1880 | current->plug = NULL; |
73c10101 | 1881 | } |
88b996cd | 1882 | EXPORT_SYMBOL(blk_finish_plug); |
73c10101 | 1883 | |
71ac860a ML |
1884 | void blk_io_schedule(void) |
1885 | { | |
1886 | /* Prevent hang_check timer from firing at us during very long I/O */ | |
1887 | unsigned long timeout = sysctl_hung_task_timeout_secs * HZ / 2; | |
1888 | ||
1889 | if (timeout) | |
1890 | io_schedule_timeout(timeout); | |
1891 | else | |
1892 | io_schedule(); | |
1893 | } | |
1894 | EXPORT_SYMBOL_GPL(blk_io_schedule); | |
1895 | ||
1da177e4 LT |
1896 | int __init blk_dev_init(void) |
1897 | { | |
ef295ecf CH |
1898 | BUILD_BUG_ON(REQ_OP_LAST >= (1 << REQ_OP_BITS)); |
1899 | BUILD_BUG_ON(REQ_OP_BITS + REQ_FLAG_BITS > 8 * | |
c593642c | 1900 | sizeof_field(struct request, cmd_flags)); |
ef295ecf | 1901 | BUILD_BUG_ON(REQ_OP_BITS + REQ_FLAG_BITS > 8 * |
c593642c | 1902 | sizeof_field(struct bio, bi_opf)); |
9eb55b03 | 1903 | |
89b90be2 TH |
1904 | /* used for unplugging and affects IO latency/throughput - HIGHPRI */ |
1905 | kblockd_workqueue = alloc_workqueue("kblockd", | |
28747fcd | 1906 | WQ_MEM_RECLAIM | WQ_HIGHPRI, 0); |
1da177e4 LT |
1907 | if (!kblockd_workqueue) |
1908 | panic("Failed to create kblockd\n"); | |
1909 | ||
c2789bd4 | 1910 | blk_requestq_cachep = kmem_cache_create("request_queue", |
165125e1 | 1911 | sizeof(struct request_queue), 0, SLAB_PANIC, NULL); |
1da177e4 | 1912 | |
18fbda91 | 1913 | blk_debugfs_root = debugfs_create_dir("block", NULL); |
18fbda91 | 1914 | |
d38ecf93 | 1915 | return 0; |
1da177e4 | 1916 | } |