block: fix use-after-free of q->q_usage_counter
[linux-block.git] / block / blk-mq.h
CommitLineData
b2441318 1/* SPDX-License-Identifier: GPL-2.0 */
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2#ifndef INT_BLK_MQ_H
3#define INT_BLK_MQ_H
4
cf43e6be 5#include "blk-stat.h"
244c65a3 6#include "blk-mq-tag.h"
cf43e6be 7
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CH
8struct blk_mq_tag_set;
9
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10struct blk_mq_ctxs {
11 struct kobject kobj;
12 struct blk_mq_ctx __percpu *queue_ctx;
13};
14
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15/**
16 * struct blk_mq_ctx - State for a software queue facing the submitting CPUs
17 */
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18struct blk_mq_ctx {
19 struct {
20 spinlock_t lock;
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21 struct list_head rq_lists[HCTX_MAX_TYPES];
22 } ____cacheline_aligned_in_smp;
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23
24 unsigned int cpu;
f31967f0 25 unsigned short index_hw[HCTX_MAX_TYPES];
8ccdf4a3 26 struct blk_mq_hw_ctx *hctxs[HCTX_MAX_TYPES];
320ae51f 27
320ae51f 28 struct request_queue *queue;
1db4909e 29 struct blk_mq_ctxs *ctxs;
320ae51f 30 struct kobject kobj;
4bb659b1 31} ____cacheline_aligned_in_smp;
320ae51f 32
3e08773c 33void blk_mq_submit_bio(struct bio *bio);
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34int blk_mq_poll(struct request_queue *q, blk_qc_t cookie, struct io_comp_batch *iob,
35 unsigned int flags);
c7e2d94b 36void blk_mq_exit_queue(struct request_queue *q);
e3a2b3f9 37int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
aed3ea94 38void blk_mq_wake_waiters(struct request_queue *q);
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39bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *,
40 unsigned int);
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41void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
42 bool kick_requeue_list);
2c3ad667 43void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
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44struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
45 struct blk_mq_ctx *start);
2e315dc0 46void blk_mq_put_rq_ref(struct request *rq);
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47
48/*
49 * Internal helpers for allocating/freeing the request map
50 */
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51void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
52 unsigned int hctx_idx);
e155b0c2 53void blk_mq_free_rq_map(struct blk_mq_tags *tags);
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JG
54struct blk_mq_tags *blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set,
55 unsigned int hctx_idx, unsigned int depth);
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JG
56void blk_mq_free_map_and_rqs(struct blk_mq_tag_set *set,
57 struct blk_mq_tags *tags,
58 unsigned int hctx_idx);
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59/*
60 * Internal helpers for request insertion into sw queues
61 */
62void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
63 bool at_head);
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64void blk_mq_request_bypass_insert(struct request *rq, bool at_head,
65 bool run_queue);
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66void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
67 struct list_head *list);
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68void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
69 struct list_head *list);
396eaf21 70
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71/*
72 * CPU -> queue mappings
73 */
ed76e329 74extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);
320ae51f 75
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76/*
77 * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue
78 * @q: request queue
e20ba6e1 79 * @type: the hctx type index
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80 * @cpu: CPU
81 */
82static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,
e20ba6e1 83 enum hctx_type type,
b3c661b1 84 unsigned int cpu)
7d7e0f90 85{
4e5cc99e 86 return xa_load(&q->hctx_table, q->tag_set->map[type].mq_map[cpu]);
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87}
88
16458cf3 89static inline enum hctx_type blk_mq_get_hctx_type(blk_opf_t opf)
ff2c5660 90{
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91 enum hctx_type type = HCTX_TYPE_DEFAULT;
92
bb94aea1 93 /*
6ce913fe 94 * The caller ensure that if REQ_POLLED, poll must be enabled.
bb94aea1 95 */
7e923f40 96 if (opf & REQ_POLLED)
e20ba6e1 97 type = HCTX_TYPE_POLL;
7e923f40 98 else if ((opf & REQ_OP_MASK) == REQ_OP_READ)
e20ba6e1 99 type = HCTX_TYPE_READ;
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100 return type;
101}
102
103/*
104 * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue
105 * @q: request queue
7e923f40 106 * @opf: operation type (REQ_OP_*) and flags (e.g. REQ_POLLED).
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107 * @ctx: software queue cpu ctx
108 */
109static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
16458cf3 110 blk_opf_t opf,
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111 struct blk_mq_ctx *ctx)
112{
7e923f40 113 return ctx->hctxs[blk_mq_get_hctx_type(opf)];
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114}
115
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116/*
117 * sysfs helpers
118 */
737f98cf 119extern void blk_mq_sysfs_init(struct request_queue *q);
7ea5fe31 120extern void blk_mq_sysfs_deinit(struct request_queue *q);
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CH
121int blk_mq_sysfs_register(struct gendisk *disk);
122void blk_mq_sysfs_unregister(struct gendisk *disk);
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CH
123int blk_mq_sysfs_register_hctxs(struct request_queue *q);
124void blk_mq_sysfs_unregister_hctxs(struct request_queue *q);
868f2f0b 125extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
47c122e3 126void blk_mq_free_plug_rqs(struct blk_plug *plug);
dbb6f764 127void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
67aec14c 128
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129void blk_mq_cancel_work_sync(struct request_queue *q);
130
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131void blk_mq_release(struct request_queue *q);
132
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133static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
134 unsigned int cpu)
135{
136 return per_cpu_ptr(q->queue_ctx, cpu);
137}
138
139/*
140 * This assumes per-cpu software queueing queues. They could be per-node
141 * as well, for instance. For now this is hardcoded as-is. Note that we don't
142 * care about preemption, since we know the ctx's are persistent. This does
143 * mean that we can't rely on ctx always matching the currently running CPU.
144 */
145static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
146{
c05f4220 147 return __blk_mq_get_ctx(q, raw_smp_processor_id());
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148}
149
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150struct blk_mq_alloc_data {
151 /* input parameter */
152 struct request_queue *q;
9a95e4ef 153 blk_mq_req_flags_t flags;
229a9287 154 unsigned int shallow_depth;
16458cf3 155 blk_opf_t cmd_flags;
ecaf97f4 156 req_flags_t rq_flags;
cb96a42c 157
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158 /* allocate multiple requests/tags in one go */
159 unsigned int nr_tags;
160 struct request **cached_rq;
161
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162 /* input & output parameter */
163 struct blk_mq_ctx *ctx;
164 struct blk_mq_hw_ctx *hctx;
165};
166
079a2e3e 167static inline bool blk_mq_is_shared_tags(unsigned int flags)
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168{
169 return flags & BLK_MQ_F_TAG_HCTX_SHARED;
170}
171
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172static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
173{
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174 if (!(data->rq_flags & RQF_ELV))
175 return data->hctx->tags;
176 return data->hctx->sched_tags;
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177}
178
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179static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
180{
181 return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
182}
183
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184static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
185{
186 return hctx->nr_ctx && hctx->tags;
187}
188
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189unsigned int blk_mq_in_flight(struct request_queue *q,
190 struct block_device *part);
191void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part,
192 unsigned int inflight[2]);
f299b7c7 193
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194static inline void blk_mq_put_dispatch_budget(struct request_queue *q,
195 int budget_token)
de148297 196{
de148297 197 if (q->mq_ops->put_budget)
2a5a24aa 198 q->mq_ops->put_budget(q, budget_token);
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199}
200
2a5a24aa 201static inline int blk_mq_get_dispatch_budget(struct request_queue *q)
de148297 202{
de148297 203 if (q->mq_ops->get_budget)
65c76369 204 return q->mq_ops->get_budget(q);
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205 return 0;
206}
207
208static inline void blk_mq_set_rq_budget_token(struct request *rq, int token)
209{
210 if (token < 0)
211 return;
212
213 if (rq->q->mq_ops->set_rq_budget_token)
214 rq->q->mq_ops->set_rq_budget_token(rq, token);
215}
216
217static inline int blk_mq_get_rq_budget_token(struct request *rq)
218{
219 if (rq->q->mq_ops->get_rq_budget_token)
220 return rq->q->mq_ops->get_rq_budget_token(rq);
221 return -1;
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222}
223
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224static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx)
225{
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226 if (blk_mq_is_shared_tags(hctx->flags))
227 atomic_inc(&hctx->queue->nr_active_requests_shared_tags);
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228 else
229 atomic_inc(&hctx->nr_active);
230}
231
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232static inline void __blk_mq_sub_active_requests(struct blk_mq_hw_ctx *hctx,
233 int val)
bccf5e26 234{
079a2e3e 235 if (blk_mq_is_shared_tags(hctx->flags))
3b87c6ea 236 atomic_sub(val, &hctx->queue->nr_active_requests_shared_tags);
bccf5e26 237 else
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238 atomic_sub(val, &hctx->nr_active);
239}
240
241static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx)
242{
243 __blk_mq_sub_active_requests(hctx, 1);
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244}
245
246static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx)
247{
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248 if (blk_mq_is_shared_tags(hctx->flags))
249 return atomic_read(&hctx->queue->nr_active_requests_shared_tags);
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250 return atomic_read(&hctx->nr_active);
251}
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252static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
253 struct request *rq)
254{
255 blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag);
256 rq->tag = BLK_MQ_NO_TAG;
257
258 if (rq->rq_flags & RQF_MQ_INFLIGHT) {
259 rq->rq_flags &= ~RQF_MQ_INFLIGHT;
bccf5e26 260 __blk_mq_dec_active_requests(hctx);
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261 }
262}
263
264static inline void blk_mq_put_driver_tag(struct request *rq)
265{
266 if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG)
267 return;
268
269 __blk_mq_put_driver_tag(rq->mq_hctx, rq);
270}
271
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272bool __blk_mq_get_driver_tag(struct blk_mq_hw_ctx *hctx, struct request *rq);
273
274static inline bool blk_mq_get_driver_tag(struct request *rq)
275{
276 struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
277
278 if (rq->tag != BLK_MQ_NO_TAG &&
279 !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) {
280 hctx->tags->rqs[rq->tag] = rq;
281 return true;
282 }
283
284 return __blk_mq_get_driver_tag(hctx, rq);
285}
61347154 286
ed76e329 287static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
0da73d00
MI
288{
289 int cpu;
290
291 for_each_possible_cpu(cpu)
ed76e329 292 qmap->mq_map[cpu] = 0;
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293}
294
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295/*
296 * blk_mq_plug() - Get caller context plug
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DLM
297 * @bio : the bio being submitted by the caller context
298 *
299 * Plugging, by design, may delay the insertion of BIOs into the elevator in
300 * order to increase BIO merging opportunities. This however can cause BIO
301 * insertion order to change from the order in which submit_bio() is being
302 * executed in the case of multiple contexts concurrently issuing BIOs to a
303 * device, even if these context are synchronized to tightly control BIO issuing
304 * order. While this is not a problem with regular block devices, this ordering
305 * change can cause write BIO failures with zoned block devices as these
306 * require sequential write patterns to zones. Prevent this from happening by
6deacb3b
CH
307 * ignoring the plug state of a BIO issuing context if it is for a zoned block
308 * device and the BIO to plug is a write operation.
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DLM
309 *
310 * Return current->plug if the bio can be plugged and NULL otherwise
311 */
6deacb3b 312static inline struct blk_plug *blk_mq_plug( struct bio *bio)
b49773e7 313{
6deacb3b 314 /* Zoned block device write operation case: do not plug the BIO */
8cafdb5a
PR
315 if (IS_ENABLED(CONFIG_BLK_DEV_ZONED) &&
316 bdev_op_is_zoned_write(bio->bi_bdev, bio_op(bio)))
6deacb3b
CH
317 return NULL;
318
b49773e7
DLM
319 /*
320 * For regular block devices or read operations, use the context plug
321 * which may be NULL if blk_start_plug() was not executed.
322 */
6deacb3b 323 return current->plug;
b49773e7
DLM
324}
325
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326/* Free all requests on the list */
327static inline void blk_mq_free_requests(struct list_head *list)
328{
329 while (!list_empty(list)) {
330 struct request *rq = list_entry_rq(list->next);
331
332 list_del_init(&rq->queuelist);
333 blk_mq_free_request(rq);
334 }
335}
336
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337/*
338 * For shared tag users, we track the number of currently active users
339 * and attempt to provide a fair share of the tag depth for each of them.
340 */
341static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
342 struct sbitmap_queue *bt)
343{
344 unsigned int depth, users;
345
346 if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED))
347 return true;
a0235d23
JG
348
349 /*
350 * Don't try dividing an ant
351 */
352 if (bt->sb.depth == 1)
353 return true;
354
079a2e3e 355 if (blk_mq_is_shared_tags(hctx->flags)) {
f1b49fdc 356 struct request_queue *q = hctx->queue;
f1b49fdc 357
2569063c 358 if (!test_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags))
f1b49fdc 359 return true;
f1b49fdc
JG
360 } else {
361 if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
362 return true;
f1b49fdc
JG
363 }
364
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JG
365 users = atomic_read(&hctx->tags->active_queues);
366
a0235d23
JG
367 if (!users)
368 return true;
369
370 /*
371 * Allow at least some tags
372 */
373 depth = max((bt->sb.depth + users - 1) / users, 4U);
bccf5e26 374 return __blk_mq_active_requests(hctx) < depth;
a0235d23
JG
375}
376
2a904d00 377/* run the code block in @dispatch_ops with rcu/srcu read lock held */
41adf531 378#define __blk_mq_run_dispatch_ops(q, check_sleep, dispatch_ops) \
2a904d00 379do { \
80bd4a7a 380 if ((q)->tag_set->flags & BLK_MQ_F_BLOCKING) { \
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ML
381 int srcu_idx; \
382 \
41adf531 383 might_sleep_if(check_sleep); \
80bd4a7a 384 srcu_idx = srcu_read_lock((q)->tag_set->srcu); \
2a904d00 385 (dispatch_ops); \
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CH
386 srcu_read_unlock((q)->tag_set->srcu, srcu_idx); \
387 } else { \
388 rcu_read_lock(); \
389 (dispatch_ops); \
390 rcu_read_unlock(); \
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391 } \
392} while (0)
a0235d23 393
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394#define blk_mq_run_dispatch_ops(q, dispatch_ops) \
395 __blk_mq_run_dispatch_ops(q, true, dispatch_ops) \
396
320ae51f 397#endif