1 /* SPDX-License-Identifier: GPL-2.0 */
6 #include <linux/blk-mq.h>
9 /* Amount of time in which a process may batch requests */
10 #define BLK_BATCH_TIME (HZ/50UL)
12 /* Number of requests a "batching" process may submit */
13 #define BLK_BATCH_REQ 32
15 /* Max future timer expiry for timeouts */
16 #define BLK_MAX_TIMEOUT (5 * HZ)
18 #ifdef CONFIG_DEBUG_FS
19 extern struct dentry *blk_debugfs_root;
22 struct blk_flush_queue {
23 unsigned int flush_queue_delayed:1;
24 unsigned int flush_pending_idx:1;
25 unsigned int flush_running_idx:1;
26 unsigned long flush_pending_since;
27 struct list_head flush_queue[2];
28 struct list_head flush_data_in_flight;
29 struct request *flush_rq;
32 * flush_rq shares tag with this rq, both can't be active
35 struct request *orig_rq;
36 spinlock_t mq_flush_lock;
39 extern struct kmem_cache *blk_requestq_cachep;
40 extern struct kmem_cache *request_cachep;
41 extern struct kobj_type blk_queue_ktype;
42 extern struct ida blk_queue_ida;
45 * @q->queue_lock is set while a queue is being initialized. Since we know
46 * that no other threads access the queue object before @q->queue_lock has
47 * been set, it is safe to manipulate queue flags without holding the
48 * queue_lock if @q->queue_lock == NULL. See also blk_alloc_queue_node() and
49 * blk_init_allocated_queue().
51 static inline void queue_lockdep_assert_held(struct request_queue *q)
54 lockdep_assert_held(q->queue_lock);
57 static inline void queue_flag_set_unlocked(unsigned int flag,
58 struct request_queue *q)
60 if (test_bit(QUEUE_FLAG_INIT_DONE, &q->queue_flags) &&
61 kref_read(&q->kobj.kref))
62 lockdep_assert_held(q->queue_lock);
63 __set_bit(flag, &q->queue_flags);
66 static inline void queue_flag_clear_unlocked(unsigned int flag,
67 struct request_queue *q)
69 if (test_bit(QUEUE_FLAG_INIT_DONE, &q->queue_flags) &&
70 kref_read(&q->kobj.kref))
71 lockdep_assert_held(q->queue_lock);
72 __clear_bit(flag, &q->queue_flags);
75 static inline int queue_flag_test_and_clear(unsigned int flag,
76 struct request_queue *q)
78 queue_lockdep_assert_held(q);
80 if (test_bit(flag, &q->queue_flags)) {
81 __clear_bit(flag, &q->queue_flags);
88 static inline int queue_flag_test_and_set(unsigned int flag,
89 struct request_queue *q)
91 queue_lockdep_assert_held(q);
93 if (!test_bit(flag, &q->queue_flags)) {
94 __set_bit(flag, &q->queue_flags);
101 static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
103 queue_lockdep_assert_held(q);
104 __set_bit(flag, &q->queue_flags);
107 static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
109 queue_lockdep_assert_held(q);
110 __clear_bit(flag, &q->queue_flags);
113 static inline struct blk_flush_queue *blk_get_flush_queue(
114 struct request_queue *q, struct blk_mq_ctx *ctx)
117 return blk_mq_map_queue(q, ctx->cpu)->fq;
121 static inline void __blk_get_queue(struct request_queue *q)
123 kobject_get(&q->kobj);
126 struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
127 int node, int cmd_size);
128 void blk_free_flush_queue(struct blk_flush_queue *q);
130 int blk_init_rl(struct request_list *rl, struct request_queue *q,
132 void blk_exit_rl(struct request_queue *q, struct request_list *rl);
133 void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
135 void blk_queue_bypass_start(struct request_queue *q);
136 void blk_queue_bypass_end(struct request_queue *q);
137 void __blk_queue_free_tags(struct request_queue *q);
138 void blk_freeze_queue(struct request_queue *q);
140 static inline void blk_queue_enter_live(struct request_queue *q)
143 * Given that running in generic_make_request() context
144 * guarantees that a live reference against q_usage_counter has
145 * been established, further references under that same context
146 * need not check that the queue has been frozen (marked dead).
148 percpu_ref_get(&q->q_usage_counter);
151 #ifdef CONFIG_BLK_DEV_INTEGRITY
152 void blk_flush_integrity(void);
153 bool __bio_integrity_endio(struct bio *);
154 static inline bool bio_integrity_endio(struct bio *bio)
156 if (bio_integrity(bio))
157 return __bio_integrity_endio(bio);
161 static inline void blk_flush_integrity(void)
164 static inline bool bio_integrity_endio(struct bio *bio)
170 void blk_timeout_work(struct work_struct *work);
171 unsigned long blk_rq_timeout(unsigned long timeout);
172 void blk_add_timer(struct request *req);
173 void blk_delete_timer(struct request *);
176 bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
178 bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
180 bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
182 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
183 unsigned int *request_count,
184 struct request **same_queue_rq);
185 unsigned int blk_plug_queued_count(struct request_queue *q);
187 void blk_account_io_start(struct request *req, bool new_io);
188 void blk_account_io_completion(struct request *req, unsigned int bytes);
189 void blk_account_io_done(struct request *req, u64 now);
192 * EH timer and IO completion will both attempt to 'grab' the request, make
193 * sure that only one of them succeeds. Steal the bottom bit of the
194 * __deadline field for this.
196 static inline int blk_mark_rq_complete(struct request *rq)
198 return test_and_set_bit(0, &rq->__deadline);
201 static inline void blk_clear_rq_complete(struct request *rq)
203 clear_bit(0, &rq->__deadline);
206 static inline bool blk_rq_is_complete(struct request *rq)
208 return test_bit(0, &rq->__deadline);
212 * Internal elevator interface
214 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
216 void blk_insert_flush(struct request *rq);
218 static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
220 struct elevator_queue *e = q->elevator;
222 if (e->type->ops.sq.elevator_activate_req_fn)
223 e->type->ops.sq.elevator_activate_req_fn(q, rq);
226 static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
228 struct elevator_queue *e = q->elevator;
230 if (e->type->ops.sq.elevator_deactivate_req_fn)
231 e->type->ops.sq.elevator_deactivate_req_fn(q, rq);
234 int elevator_init(struct request_queue *);
235 void elevator_exit(struct request_queue *, struct elevator_queue *);
236 int elv_register_queue(struct request_queue *q);
237 void elv_unregister_queue(struct request_queue *q);
239 struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
241 #ifdef CONFIG_FAIL_IO_TIMEOUT
242 int blk_should_fake_timeout(struct request_queue *);
243 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
244 ssize_t part_timeout_store(struct device *, struct device_attribute *,
245 const char *, size_t);
247 static inline int blk_should_fake_timeout(struct request_queue *q)
253 int ll_back_merge_fn(struct request_queue *q, struct request *req,
255 int ll_front_merge_fn(struct request_queue *q, struct request *req,
257 struct request *attempt_back_merge(struct request_queue *q, struct request *rq);
258 struct request *attempt_front_merge(struct request_queue *q, struct request *rq);
259 int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
260 struct request *next);
261 void blk_recalc_rq_segments(struct request *rq);
262 void blk_rq_set_mixed_merge(struct request *rq);
263 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
264 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
266 void blk_queue_congestion_threshold(struct request_queue *q);
268 int blk_dev_init(void);
272 * Return the threshold (number of used requests) at which the queue is
273 * considered to be congested. It include a little hysteresis to keep the
274 * context switch rate down.
276 static inline int queue_congestion_on_threshold(struct request_queue *q)
278 return q->nr_congestion_on;
282 * The threshold at which a queue is considered to be uncongested
284 static inline int queue_congestion_off_threshold(struct request_queue *q)
286 return q->nr_congestion_off;
289 extern int blk_update_nr_requests(struct request_queue *, unsigned int);
292 * Contribute to IO statistics IFF:
294 * a) it's attached to a gendisk, and
295 * b) the queue had IO stats enabled when this request was started, and
296 * c) it's a file system request
298 static inline int blk_do_io_stat(struct request *rq)
300 return rq->rq_disk &&
301 (rq->rq_flags & RQF_IO_STAT) &&
302 !blk_rq_is_passthrough(rq);
305 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
307 req->cmd_flags |= REQ_NOMERGE;
308 if (req == q->last_merge)
309 q->last_merge = NULL;
313 * Steal a bit from this field for legacy IO path atomic IO marking. Note that
314 * setting the deadline clears the bottom bit, potentially clearing the
315 * completed bit. The user has to be OK with this (current ones are fine).
317 static inline void blk_rq_set_deadline(struct request *rq, unsigned long time)
319 rq->__deadline = time & ~0x1UL;
322 static inline unsigned long blk_rq_deadline(struct request *rq)
324 return rq->__deadline & ~0x1UL;
328 * Internal io_context interface
330 void get_io_context(struct io_context *ioc);
331 struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
332 struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
334 void ioc_clear_queue(struct request_queue *q);
336 int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
339 * rq_ioc - determine io_context for request allocation
340 * @bio: request being allocated is for this bio (can be %NULL)
342 * Determine io_context to use for request allocation for @bio. May return
343 * %NULL if %current->io_context doesn't exist.
345 static inline struct io_context *rq_ioc(struct bio *bio)
347 #ifdef CONFIG_BLK_CGROUP
348 if (bio && bio->bi_ioc)
351 return current->io_context;
355 * create_io_context - try to create task->io_context
356 * @gfp_mask: allocation mask
357 * @node: allocation node
359 * If %current->io_context is %NULL, allocate a new io_context and install
360 * it. Returns the current %current->io_context which may be %NULL if
363 * Note that this function can't be called with IRQ disabled because
364 * task_lock which protects %current->io_context is IRQ-unsafe.
366 static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
368 WARN_ON_ONCE(irqs_disabled());
369 if (unlikely(!current->io_context))
370 create_task_io_context(current, gfp_mask, node);
371 return current->io_context;
375 * Internal throttling interface
377 #ifdef CONFIG_BLK_DEV_THROTTLING
378 extern void blk_throtl_drain(struct request_queue *q);
379 extern int blk_throtl_init(struct request_queue *q);
380 extern void blk_throtl_exit(struct request_queue *q);
381 extern void blk_throtl_register_queue(struct request_queue *q);
382 #else /* CONFIG_BLK_DEV_THROTTLING */
383 static inline void blk_throtl_drain(struct request_queue *q) { }
384 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
385 static inline void blk_throtl_exit(struct request_queue *q) { }
386 static inline void blk_throtl_register_queue(struct request_queue *q) { }
387 #endif /* CONFIG_BLK_DEV_THROTTLING */
388 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
389 extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
390 extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
391 const char *page, size_t count);
392 extern void blk_throtl_bio_endio(struct bio *bio);
393 extern void blk_throtl_stat_add(struct request *rq, u64 time);
395 static inline void blk_throtl_bio_endio(struct bio *bio) { }
396 static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
400 extern int init_emergency_isa_pool(void);
401 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
403 static inline int init_emergency_isa_pool(void)
407 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
410 #endif /* CONFIG_BOUNCE */
412 extern void blk_drain_queue(struct request_queue *q);
414 #endif /* BLK_INTERNAL_H */