block: avoid double io accounting for flush request
[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];
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27
28 /* incremented at dispatch time */
29 unsigned long rq_dispatched[2];
30 unsigned long rq_merged;
31
32 /* incremented at completion time */
33 unsigned long ____cacheline_aligned_in_smp rq_completed[2];
34
35 struct request_queue *queue;
1db4909e 36 struct blk_mq_ctxs *ctxs;
320ae51f 37 struct kobject kobj;
4bb659b1 38} ____cacheline_aligned_in_smp;
320ae51f 39
c7e2d94b 40void blk_mq_exit_queue(struct request_queue *q);
e3a2b3f9 41int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
aed3ea94 42void blk_mq_wake_waiters(struct request_queue *q);
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43bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *,
44 unsigned int);
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45void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
46 bool kick_requeue_list);
2c3ad667 47void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list);
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48struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
49 struct blk_mq_ctx *start);
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50
51/*
52 * Internal helpers for allocating/freeing the request map
53 */
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54void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
55 unsigned int hctx_idx);
1c0706a7 56void blk_mq_free_rq_map(struct blk_mq_tags *tags, unsigned int flags);
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57struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
58 unsigned int hctx_idx,
59 unsigned int nr_tags,
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60 unsigned int reserved_tags,
61 unsigned int flags);
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62int blk_mq_alloc_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
63 unsigned int hctx_idx, unsigned int depth);
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64
65/*
66 * Internal helpers for request insertion into sw queues
67 */
68void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
69 bool at_head);
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70void blk_mq_request_bypass_insert(struct request *rq, bool at_head,
71 bool run_queue);
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72void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
73 struct list_head *list);
320ae51f 74
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75/* Used by blk_insert_cloned_request() to issue request directly */
76blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last);
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77void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
78 struct list_head *list);
396eaf21 79
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80/*
81 * CPU -> queue mappings
82 */
ed76e329 83extern int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int);
320ae51f 84
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85/*
86 * blk_mq_map_queue_type() - map (hctx_type,cpu) to hardware queue
87 * @q: request queue
e20ba6e1 88 * @type: the hctx type index
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89 * @cpu: CPU
90 */
91static inline struct blk_mq_hw_ctx *blk_mq_map_queue_type(struct request_queue *q,
e20ba6e1 92 enum hctx_type type,
b3c661b1 93 unsigned int cpu)
7d7e0f90 94{
e20ba6e1 95 return q->queue_hw_ctx[q->tag_set->map[type].mq_map[cpu]];
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96}
97
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98/*
99 * blk_mq_map_queue() - map (cmd_flags,type) to hardware queue
100 * @q: request queue
101 * @flags: request command flags
d220a214 102 * @ctx: software queue cpu ctx
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103 */
104static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
105 unsigned int flags,
8ccdf4a3 106 struct blk_mq_ctx *ctx)
ff2c5660 107{
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108 enum hctx_type type = HCTX_TYPE_DEFAULT;
109
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110 /*
111 * The caller ensure that if REQ_HIPRI, poll must be enabled.
112 */
113 if (flags & REQ_HIPRI)
e20ba6e1 114 type = HCTX_TYPE_POLL;
bb94aea1 115 else if ((flags & REQ_OP_MASK) == REQ_OP_READ)
e20ba6e1 116 type = HCTX_TYPE_READ;
5aceaeb2 117
8ccdf4a3 118 return ctx->hctxs[type];
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119}
120
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121/*
122 * sysfs helpers
123 */
737f98cf 124extern void blk_mq_sysfs_init(struct request_queue *q);
7ea5fe31 125extern void blk_mq_sysfs_deinit(struct request_queue *q);
2d0364c8 126extern int __blk_mq_register_dev(struct device *dev, struct request_queue *q);
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127extern int blk_mq_sysfs_register(struct request_queue *q);
128extern void blk_mq_sysfs_unregister(struct request_queue *q);
868f2f0b 129extern void blk_mq_hctx_kobj_init(struct blk_mq_hw_ctx *hctx);
67aec14c 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;
f9afca4d 155 unsigned int cmd_flags;
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156
157 /* input & output parameter */
158 struct blk_mq_ctx *ctx;
159 struct blk_mq_hw_ctx *hctx;
160};
161
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162static inline bool blk_mq_is_sbitmap_shared(unsigned int flags)
163{
164 return flags & BLK_MQ_F_TAG_HCTX_SHARED;
165}
166
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167static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
168{
42fdc5e4 169 if (data->q->elevator)
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170 return data->hctx->sched_tags;
171
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172 return data->hctx->tags;
173}
174
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175static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
176{
177 return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
178}
179
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180static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
181{
182 return hctx->nr_ctx && hctx->tags;
183}
184
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185unsigned int blk_mq_in_flight(struct request_queue *q,
186 struct block_device *part);
187void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part,
188 unsigned int inflight[2]);
f299b7c7 189
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190static inline void blk_mq_put_dispatch_budget(struct request_queue *q,
191 int budget_token)
de148297 192{
de148297 193 if (q->mq_ops->put_budget)
2a5a24aa 194 q->mq_ops->put_budget(q, budget_token);
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195}
196
2a5a24aa 197static inline int blk_mq_get_dispatch_budget(struct request_queue *q)
de148297 198{
de148297 199 if (q->mq_ops->get_budget)
65c76369 200 return q->mq_ops->get_budget(q);
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201 return 0;
202}
203
204static inline void blk_mq_set_rq_budget_token(struct request *rq, int token)
205{
206 if (token < 0)
207 return;
208
209 if (rq->q->mq_ops->set_rq_budget_token)
210 rq->q->mq_ops->set_rq_budget_token(rq, token);
211}
212
213static inline int blk_mq_get_rq_budget_token(struct request *rq)
214{
215 if (rq->q->mq_ops->get_rq_budget_token)
216 return rq->q->mq_ops->get_rq_budget_token(rq);
217 return -1;
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218}
219
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220static inline void __blk_mq_inc_active_requests(struct blk_mq_hw_ctx *hctx)
221{
222 if (blk_mq_is_sbitmap_shared(hctx->flags))
223 atomic_inc(&hctx->queue->nr_active_requests_shared_sbitmap);
224 else
225 atomic_inc(&hctx->nr_active);
226}
227
228static inline void __blk_mq_dec_active_requests(struct blk_mq_hw_ctx *hctx)
229{
230 if (blk_mq_is_sbitmap_shared(hctx->flags))
231 atomic_dec(&hctx->queue->nr_active_requests_shared_sbitmap);
232 else
233 atomic_dec(&hctx->nr_active);
234}
235
236static inline int __blk_mq_active_requests(struct blk_mq_hw_ctx *hctx)
237{
238 if (blk_mq_is_sbitmap_shared(hctx->flags))
239 return atomic_read(&hctx->queue->nr_active_requests_shared_sbitmap);
240 return atomic_read(&hctx->nr_active);
241}
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242static inline void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx,
243 struct request *rq)
244{
245 blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag);
246 rq->tag = BLK_MQ_NO_TAG;
247
248 if (rq->rq_flags & RQF_MQ_INFLIGHT) {
249 rq->rq_flags &= ~RQF_MQ_INFLIGHT;
bccf5e26 250 __blk_mq_dec_active_requests(hctx);
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251 }
252}
253
254static inline void blk_mq_put_driver_tag(struct request *rq)
255{
256 if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG)
257 return;
258
259 __blk_mq_put_driver_tag(rq->mq_hctx, rq);
260}
261
ed76e329 262static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
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263{
264 int cpu;
265
266 for_each_possible_cpu(cpu)
ed76e329 267 qmap->mq_map[cpu] = 0;
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268}
269
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270/*
271 * blk_mq_plug() - Get caller context plug
272 * @q: request queue
273 * @bio : the bio being submitted by the caller context
274 *
275 * Plugging, by design, may delay the insertion of BIOs into the elevator in
276 * order to increase BIO merging opportunities. This however can cause BIO
277 * insertion order to change from the order in which submit_bio() is being
278 * executed in the case of multiple contexts concurrently issuing BIOs to a
279 * device, even if these context are synchronized to tightly control BIO issuing
280 * order. While this is not a problem with regular block devices, this ordering
281 * change can cause write BIO failures with zoned block devices as these
282 * require sequential write patterns to zones. Prevent this from happening by
283 * ignoring the plug state of a BIO issuing context if the target request queue
284 * is for a zoned block device and the BIO to plug is a write operation.
285 *
286 * Return current->plug if the bio can be plugged and NULL otherwise
287 */
288static inline struct blk_plug *blk_mq_plug(struct request_queue *q,
289 struct bio *bio)
290{
291 /*
292 * For regular block devices or read operations, use the context plug
293 * which may be NULL if blk_start_plug() was not executed.
294 */
295 if (!blk_queue_is_zoned(q) || !op_is_write(bio_op(bio)))
296 return current->plug;
297
298 /* Zoned block device write operation case: do not plug the BIO */
299 return NULL;
300}
301
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302/*
303 * For shared tag users, we track the number of currently active users
304 * and attempt to provide a fair share of the tag depth for each of them.
305 */
306static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
307 struct sbitmap_queue *bt)
308{
309 unsigned int depth, users;
310
311 if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED))
312 return true;
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313
314 /*
315 * Don't try dividing an ant
316 */
317 if (bt->sb.depth == 1)
318 return true;
319
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320 if (blk_mq_is_sbitmap_shared(hctx->flags)) {
321 struct request_queue *q = hctx->queue;
322 struct blk_mq_tag_set *set = q->tag_set;
323
2569063c 324 if (!test_bit(QUEUE_FLAG_HCTX_ACTIVE, &q->queue_flags))
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JG
325 return true;
326 users = atomic_read(&set->active_queues_shared_sbitmap);
327 } else {
328 if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state))
329 return true;
330 users = atomic_read(&hctx->tags->active_queues);
331 }
332
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333 if (!users)
334 return true;
335
336 /*
337 * Allow at least some tags
338 */
339 depth = max((bt->sb.depth + users - 1) / users, 4U);
bccf5e26 340 return __blk_mq_active_requests(hctx) < depth;
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341}
342
343
320ae51f 344#endif