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
;
44 static inline struct blk_flush_queue
*blk_get_flush_queue(
45 struct request_queue
*q
, struct blk_mq_ctx
*ctx
)
48 return blk_mq_map_queue(q
, ctx
->cpu
)->fq
;
52 static inline void __blk_get_queue(struct request_queue
*q
)
54 kobject_get(&q
->kobj
);
57 struct blk_flush_queue
*blk_alloc_flush_queue(struct request_queue
*q
,
58 int node
, int cmd_size
);
59 void blk_free_flush_queue(struct blk_flush_queue
*q
);
61 int blk_init_rl(struct request_list
*rl
, struct request_queue
*q
,
63 void blk_exit_rl(struct request_queue
*q
, struct request_list
*rl
);
64 void blk_rq_bio_prep(struct request_queue
*q
, struct request
*rq
,
66 void blk_queue_bypass_start(struct request_queue
*q
);
67 void blk_queue_bypass_end(struct request_queue
*q
);
68 void __blk_queue_free_tags(struct request_queue
*q
);
69 void blk_freeze_queue(struct request_queue
*q
);
71 static inline void blk_queue_enter_live(struct request_queue
*q
)
74 * Given that running in generic_make_request() context
75 * guarantees that a live reference against q_usage_counter has
76 * been established, further references under that same context
77 * need not check that the queue has been frozen (marked dead).
79 percpu_ref_get(&q
->q_usage_counter
);
82 #ifdef CONFIG_BLK_DEV_INTEGRITY
83 void blk_flush_integrity(void);
84 bool __bio_integrity_endio(struct bio
*);
85 static inline bool bio_integrity_endio(struct bio
*bio
)
87 if (bio_integrity(bio
))
88 return __bio_integrity_endio(bio
);
92 static inline void blk_flush_integrity(void)
95 static inline bool bio_integrity_endio(struct bio
*bio
)
101 void blk_timeout_work(struct work_struct
*work
);
102 unsigned long blk_rq_timeout(unsigned long timeout
);
103 void blk_add_timer(struct request
*req
);
104 void blk_delete_timer(struct request
*);
107 bool bio_attempt_front_merge(struct request_queue
*q
, struct request
*req
,
109 bool bio_attempt_back_merge(struct request_queue
*q
, struct request
*req
,
111 bool bio_attempt_discard_merge(struct request_queue
*q
, struct request
*req
,
113 bool blk_attempt_plug_merge(struct request_queue
*q
, struct bio
*bio
,
114 unsigned int *request_count
,
115 struct request
**same_queue_rq
);
116 unsigned int blk_plug_queued_count(struct request_queue
*q
);
118 void blk_account_io_start(struct request
*req
, bool new_io
);
119 void blk_account_io_completion(struct request
*req
, unsigned int bytes
);
120 void blk_account_io_done(struct request
*req
);
123 * Internal atomic flags for request handling
125 enum rq_atomic_flags
{
126 REQ_ATOM_COMPLETE
= 0,
132 * EH timer and IO completion will both attempt to 'grab' the request, make
133 * sure that only one of them succeeds
135 static inline int blk_mark_rq_complete(struct request
*rq
)
137 return test_and_set_bit(REQ_ATOM_COMPLETE
, &rq
->atomic_flags
);
140 static inline void blk_clear_rq_complete(struct request
*rq
)
142 clear_bit(REQ_ATOM_COMPLETE
, &rq
->atomic_flags
);
146 * Internal elevator interface
148 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
150 void blk_insert_flush(struct request
*rq
);
152 static inline struct request
*__elv_next_request(struct request_queue
*q
)
155 struct blk_flush_queue
*fq
= blk_get_flush_queue(q
, NULL
);
157 WARN_ON_ONCE(q
->mq_ops
);
160 if (!list_empty(&q
->queue_head
)) {
161 rq
= list_entry_rq(q
->queue_head
.next
);
166 * Flush request is running and flush request isn't queueable
167 * in the drive, we can hold the queue till flush request is
168 * finished. Even we don't do this, driver can't dispatch next
169 * requests and will requeue them. And this can improve
170 * throughput too. For example, we have request flush1, write1,
171 * flush 2. flush1 is dispatched, then queue is hold, write1
172 * isn't inserted to queue. After flush1 is finished, flush2
173 * will be dispatched. Since disk cache is already clean,
174 * flush2 will be finished very soon, so looks like flush2 is
176 * Since the queue is hold, a flag is set to indicate the queue
177 * should be restarted later. Please see flush_end_io() for
180 if (fq
->flush_pending_idx
!= fq
->flush_running_idx
&&
181 !queue_flush_queueable(q
)) {
182 fq
->flush_queue_delayed
= 1;
185 if (unlikely(blk_queue_bypass(q
)) ||
186 !q
->elevator
->type
->ops
.sq
.elevator_dispatch_fn(q
, 0))
191 static inline void elv_activate_rq(struct request_queue
*q
, struct request
*rq
)
193 struct elevator_queue
*e
= q
->elevator
;
195 if (e
->type
->ops
.sq
.elevator_activate_req_fn
)
196 e
->type
->ops
.sq
.elevator_activate_req_fn(q
, rq
);
199 static inline void elv_deactivate_rq(struct request_queue
*q
, struct request
*rq
)
201 struct elevator_queue
*e
= q
->elevator
;
203 if (e
->type
->ops
.sq
.elevator_deactivate_req_fn
)
204 e
->type
->ops
.sq
.elevator_deactivate_req_fn(q
, rq
);
207 struct hd_struct
*__disk_get_part(struct gendisk
*disk
, int partno
);
209 #ifdef CONFIG_FAIL_IO_TIMEOUT
210 int blk_should_fake_timeout(struct request_queue
*);
211 ssize_t
part_timeout_show(struct device
*, struct device_attribute
*, char *);
212 ssize_t
part_timeout_store(struct device
*, struct device_attribute
*,
213 const char *, size_t);
215 static inline int blk_should_fake_timeout(struct request_queue
*q
)
221 int ll_back_merge_fn(struct request_queue
*q
, struct request
*req
,
223 int ll_front_merge_fn(struct request_queue
*q
, struct request
*req
,
225 struct request
*attempt_back_merge(struct request_queue
*q
, struct request
*rq
);
226 struct request
*attempt_front_merge(struct request_queue
*q
, struct request
*rq
);
227 int blk_attempt_req_merge(struct request_queue
*q
, struct request
*rq
,
228 struct request
*next
);
229 void blk_recalc_rq_segments(struct request
*rq
);
230 void blk_rq_set_mixed_merge(struct request
*rq
);
231 bool blk_rq_merge_ok(struct request
*rq
, struct bio
*bio
);
232 enum elv_merge
blk_try_merge(struct request
*rq
, struct bio
*bio
);
234 void blk_queue_congestion_threshold(struct request_queue
*q
);
236 int blk_dev_init(void);
240 * Return the threshold (number of used requests) at which the queue is
241 * considered to be congested. It include a little hysteresis to keep the
242 * context switch rate down.
244 static inline int queue_congestion_on_threshold(struct request_queue
*q
)
246 return q
->nr_congestion_on
;
250 * The threshold at which a queue is considered to be uncongested
252 static inline int queue_congestion_off_threshold(struct request_queue
*q
)
254 return q
->nr_congestion_off
;
257 extern int blk_update_nr_requests(struct request_queue
*, unsigned int);
260 * Contribute to IO statistics IFF:
262 * a) it's attached to a gendisk, and
263 * b) the queue had IO stats enabled when this request was started, and
264 * c) it's a file system request
266 static inline int blk_do_io_stat(struct request
*rq
)
268 return rq
->rq_disk
&&
269 (rq
->rq_flags
& RQF_IO_STAT
) &&
270 !blk_rq_is_passthrough(rq
);
273 static inline void req_set_nomerge(struct request_queue
*q
, struct request
*req
)
275 req
->cmd_flags
|= REQ_NOMERGE
;
276 if (req
== q
->last_merge
)
277 q
->last_merge
= NULL
;
281 * Internal io_context interface
283 void get_io_context(struct io_context
*ioc
);
284 struct io_cq
*ioc_lookup_icq(struct io_context
*ioc
, struct request_queue
*q
);
285 struct io_cq
*ioc_create_icq(struct io_context
*ioc
, struct request_queue
*q
,
287 void ioc_clear_queue(struct request_queue
*q
);
289 int create_task_io_context(struct task_struct
*task
, gfp_t gfp_mask
, int node
);
292 * rq_ioc - determine io_context for request allocation
293 * @bio: request being allocated is for this bio (can be %NULL)
295 * Determine io_context to use for request allocation for @bio. May return
296 * %NULL if %current->io_context doesn't exist.
298 static inline struct io_context
*rq_ioc(struct bio
*bio
)
300 #ifdef CONFIG_BLK_CGROUP
301 if (bio
&& bio
->bi_ioc
)
304 return current
->io_context
;
308 * create_io_context - try to create task->io_context
309 * @gfp_mask: allocation mask
310 * @node: allocation node
312 * If %current->io_context is %NULL, allocate a new io_context and install
313 * it. Returns the current %current->io_context which may be %NULL if
316 * Note that this function can't be called with IRQ disabled because
317 * task_lock which protects %current->io_context is IRQ-unsafe.
319 static inline struct io_context
*create_io_context(gfp_t gfp_mask
, int node
)
321 WARN_ON_ONCE(irqs_disabled());
322 if (unlikely(!current
->io_context
))
323 create_task_io_context(current
, gfp_mask
, node
);
324 return current
->io_context
;
328 * Internal throttling interface
330 #ifdef CONFIG_BLK_DEV_THROTTLING
331 extern void blk_throtl_drain(struct request_queue
*q
);
332 extern int blk_throtl_init(struct request_queue
*q
);
333 extern void blk_throtl_exit(struct request_queue
*q
);
334 extern void blk_throtl_register_queue(struct request_queue
*q
);
335 #else /* CONFIG_BLK_DEV_THROTTLING */
336 static inline void blk_throtl_drain(struct request_queue
*q
) { }
337 static inline int blk_throtl_init(struct request_queue
*q
) { return 0; }
338 static inline void blk_throtl_exit(struct request_queue
*q
) { }
339 static inline void blk_throtl_register_queue(struct request_queue
*q
) { }
340 #endif /* CONFIG_BLK_DEV_THROTTLING */
341 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
342 extern ssize_t
blk_throtl_sample_time_show(struct request_queue
*q
, char *page
);
343 extern ssize_t
blk_throtl_sample_time_store(struct request_queue
*q
,
344 const char *page
, size_t count
);
345 extern void blk_throtl_bio_endio(struct bio
*bio
);
346 extern void blk_throtl_stat_add(struct request
*rq
, u64 time
);
348 static inline void blk_throtl_bio_endio(struct bio
*bio
) { }
349 static inline void blk_throtl_stat_add(struct request
*rq
, u64 time
) { }
353 extern int init_emergency_isa_pool(void);
354 extern void blk_queue_bounce(struct request_queue
*q
, struct bio
**bio
);
356 static inline int init_emergency_isa_pool(void)
360 static inline void blk_queue_bounce(struct request_queue
*q
, struct bio
**bio
)
363 #endif /* CONFIG_BOUNCE */
365 extern void blk_drain_queue(struct request_queue
*q
);
367 #endif /* BLK_INTERNAL_H */