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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef BLK_INTERNAL_H
3#define BLK_INTERNAL_H
4
5#include <linux/idr.h>
6#include <linux/blk-mq.h>
7#include <xen/xen.h>
8#include "blk-mq.h"
9#include "blk-mq-sched.h"
10
11/* Max future timer expiry for timeouts */
12#define BLK_MAX_TIMEOUT (5 * HZ)
13
14#ifdef CONFIG_DEBUG_FS
15extern struct dentry *blk_debugfs_root;
16#endif
17
18struct blk_flush_queue {
19 unsigned int flush_queue_delayed:1;
20 unsigned int flush_pending_idx:1;
21 unsigned int flush_running_idx:1;
22 blk_status_t rq_status;
23 unsigned long flush_pending_since;
24 struct list_head flush_queue[2];
25 struct list_head flush_data_in_flight;
26 struct request *flush_rq;
27
28 /*
29 * flush_rq shares tag with this rq, both can't be active
30 * at the same time
31 */
32 struct request *orig_rq;
33 spinlock_t mq_flush_lock;
34};
35
36extern struct kmem_cache *blk_requestq_cachep;
37extern struct kobj_type blk_queue_ktype;
38extern struct ida blk_queue_ida;
39
40static inline struct blk_flush_queue *
41blk_get_flush_queue(struct request_queue *q, struct blk_mq_ctx *ctx)
42{
43 return blk_mq_map_queue(q, REQ_OP_FLUSH, ctx)->fq;
44}
45
46static inline void __blk_get_queue(struct request_queue *q)
47{
48 kobject_get(&q->kobj);
49}
50
51static inline bool
52is_flush_rq(struct request *req, struct blk_mq_hw_ctx *hctx)
53{
54 return hctx->fq->flush_rq == req;
55}
56
57struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
58 int node, int cmd_size, gfp_t flags);
59void blk_free_flush_queue(struct blk_flush_queue *q);
60
61void blk_freeze_queue(struct request_queue *q);
62
63static inline void blk_queue_enter_live(struct request_queue *q)
64{
65 /*
66 * Given that running in generic_make_request() context
67 * guarantees that a live reference against q_usage_counter has
68 * been established, further references under that same context
69 * need not check that the queue has been frozen (marked dead).
70 */
71 percpu_ref_get(&q->q_usage_counter);
72}
73
74static inline bool biovec_phys_mergeable(struct request_queue *q,
75 struct bio_vec *vec1, struct bio_vec *vec2)
76{
77 unsigned long mask = queue_segment_boundary(q);
78 phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset;
79 phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset;
80
81 if (addr1 + vec1->bv_len != addr2)
82 return false;
83 if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
84 return false;
85 if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
86 return false;
87 return true;
88}
89
90static inline bool __bvec_gap_to_prev(struct request_queue *q,
91 struct bio_vec *bprv, unsigned int offset)
92{
93 return (offset & queue_virt_boundary(q)) ||
94 ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q));
95}
96
97/*
98 * Check if adding a bio_vec after bprv with offset would create a gap in
99 * the SG list. Most drivers don't care about this, but some do.
100 */
101static inline bool bvec_gap_to_prev(struct request_queue *q,
102 struct bio_vec *bprv, unsigned int offset)
103{
104 if (!queue_virt_boundary(q))
105 return false;
106 return __bvec_gap_to_prev(q, bprv, offset);
107}
108
109static inline void blk_rq_bio_prep(struct request *rq, struct bio *bio,
110 unsigned int nr_segs)
111{
112 rq->nr_phys_segments = nr_segs;
113 rq->__data_len = bio->bi_iter.bi_size;
114 rq->bio = rq->biotail = bio;
115 rq->ioprio = bio_prio(bio);
116
117 if (bio->bi_disk)
118 rq->rq_disk = bio->bi_disk;
119}
120
121#ifdef CONFIG_BLK_DEV_INTEGRITY
122void blk_flush_integrity(void);
123bool __bio_integrity_endio(struct bio *);
124static inline bool bio_integrity_endio(struct bio *bio)
125{
126 if (bio_integrity(bio))
127 return __bio_integrity_endio(bio);
128 return true;
129}
130
131static inline bool integrity_req_gap_back_merge(struct request *req,
132 struct bio *next)
133{
134 struct bio_integrity_payload *bip = bio_integrity(req->bio);
135 struct bio_integrity_payload *bip_next = bio_integrity(next);
136
137 return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
138 bip_next->bip_vec[0].bv_offset);
139}
140
141static inline bool integrity_req_gap_front_merge(struct request *req,
142 struct bio *bio)
143{
144 struct bio_integrity_payload *bip = bio_integrity(bio);
145 struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
146
147 return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
148 bip_next->bip_vec[0].bv_offset);
149}
150#else /* CONFIG_BLK_DEV_INTEGRITY */
151static inline bool integrity_req_gap_back_merge(struct request *req,
152 struct bio *next)
153{
154 return false;
155}
156static inline bool integrity_req_gap_front_merge(struct request *req,
157 struct bio *bio)
158{
159 return false;
160}
161
162static inline void blk_flush_integrity(void)
163{
164}
165static inline bool bio_integrity_endio(struct bio *bio)
166{
167 return true;
168}
169#endif /* CONFIG_BLK_DEV_INTEGRITY */
170
171unsigned long blk_rq_timeout(unsigned long timeout);
172void blk_add_timer(struct request *req);
173
174bool bio_attempt_front_merge(struct request *req, struct bio *bio,
175 unsigned int nr_segs);
176bool bio_attempt_back_merge(struct request *req, struct bio *bio,
177 unsigned int nr_segs);
178bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
179 struct bio *bio);
180bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
181 unsigned int nr_segs, struct request **same_queue_rq);
182
183void blk_account_io_start(struct request *req, bool new_io);
184void blk_account_io_completion(struct request *req, unsigned int bytes);
185void blk_account_io_done(struct request *req, u64 now);
186
187/*
188 * Internal elevator interface
189 */
190#define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
191
192void blk_insert_flush(struct request *rq);
193
194void elevator_init_mq(struct request_queue *q);
195int elevator_switch_mq(struct request_queue *q,
196 struct elevator_type *new_e);
197void __elevator_exit(struct request_queue *, struct elevator_queue *);
198int elv_register_queue(struct request_queue *q, bool uevent);
199void elv_unregister_queue(struct request_queue *q);
200
201static inline void elevator_exit(struct request_queue *q,
202 struct elevator_queue *e)
203{
204 lockdep_assert_held(&q->sysfs_lock);
205
206 blk_mq_sched_free_requests(q);
207 __elevator_exit(q, e);
208}
209
210struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
211
212#ifdef CONFIG_FAIL_IO_TIMEOUT
213int blk_should_fake_timeout(struct request_queue *);
214ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
215ssize_t part_timeout_store(struct device *, struct device_attribute *,
216 const char *, size_t);
217#else
218static inline int blk_should_fake_timeout(struct request_queue *q)
219{
220 return 0;
221}
222#endif
223
224void __blk_queue_split(struct request_queue *q, struct bio **bio,
225 unsigned int *nr_segs);
226int ll_back_merge_fn(struct request *req, struct bio *bio,
227 unsigned int nr_segs);
228int ll_front_merge_fn(struct request *req, struct bio *bio,
229 unsigned int nr_segs);
230struct request *attempt_back_merge(struct request_queue *q, struct request *rq);
231struct request *attempt_front_merge(struct request_queue *q, struct request *rq);
232int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
233 struct request *next);
234unsigned int blk_recalc_rq_segments(struct request *rq);
235void blk_rq_set_mixed_merge(struct request *rq);
236bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
237enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
238
239int blk_dev_init(void);
240
241/*
242 * Contribute to IO statistics IFF:
243 *
244 * a) it's attached to a gendisk, and
245 * b) the queue had IO stats enabled when this request was started, and
246 * c) it's a file system request
247 */
248static inline bool blk_do_io_stat(struct request *rq)
249{
250 return rq->rq_disk &&
251 (rq->rq_flags & RQF_IO_STAT) &&
252 !blk_rq_is_passthrough(rq);
253}
254
255static inline void req_set_nomerge(struct request_queue *q, struct request *req)
256{
257 req->cmd_flags |= REQ_NOMERGE;
258 if (req == q->last_merge)
259 q->last_merge = NULL;
260}
261
262/*
263 * The max size one bio can handle is UINT_MAX becasue bvec_iter.bi_size
264 * is defined as 'unsigned int', meantime it has to aligned to with logical
265 * block size which is the minimum accepted unit by hardware.
266 */
267static inline unsigned int bio_allowed_max_sectors(struct request_queue *q)
268{
269 return round_down(UINT_MAX, queue_logical_block_size(q)) >> 9;
270}
271
272/*
273 * Internal io_context interface
274 */
275void get_io_context(struct io_context *ioc);
276struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
277struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
278 gfp_t gfp_mask);
279void ioc_clear_queue(struct request_queue *q);
280
281int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
282
283/**
284 * create_io_context - try to create task->io_context
285 * @gfp_mask: allocation mask
286 * @node: allocation node
287 *
288 * If %current->io_context is %NULL, allocate a new io_context and install
289 * it. Returns the current %current->io_context which may be %NULL if
290 * allocation failed.
291 *
292 * Note that this function can't be called with IRQ disabled because
293 * task_lock which protects %current->io_context is IRQ-unsafe.
294 */
295static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
296{
297 WARN_ON_ONCE(irqs_disabled());
298 if (unlikely(!current->io_context))
299 create_task_io_context(current, gfp_mask, node);
300 return current->io_context;
301}
302
303/*
304 * Internal throttling interface
305 */
306#ifdef CONFIG_BLK_DEV_THROTTLING
307extern void blk_throtl_drain(struct request_queue *q);
308extern int blk_throtl_init(struct request_queue *q);
309extern void blk_throtl_exit(struct request_queue *q);
310extern void blk_throtl_register_queue(struct request_queue *q);
311#else /* CONFIG_BLK_DEV_THROTTLING */
312static inline void blk_throtl_drain(struct request_queue *q) { }
313static inline int blk_throtl_init(struct request_queue *q) { return 0; }
314static inline void blk_throtl_exit(struct request_queue *q) { }
315static inline void blk_throtl_register_queue(struct request_queue *q) { }
316#endif /* CONFIG_BLK_DEV_THROTTLING */
317#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
318extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
319extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
320 const char *page, size_t count);
321extern void blk_throtl_bio_endio(struct bio *bio);
322extern void blk_throtl_stat_add(struct request *rq, u64 time);
323#else
324static inline void blk_throtl_bio_endio(struct bio *bio) { }
325static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
326#endif
327
328#ifdef CONFIG_BOUNCE
329extern int init_emergency_isa_pool(void);
330extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
331#else
332static inline int init_emergency_isa_pool(void)
333{
334 return 0;
335}
336static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
337{
338}
339#endif /* CONFIG_BOUNCE */
340
341#ifdef CONFIG_BLK_CGROUP_IOLATENCY
342extern int blk_iolatency_init(struct request_queue *q);
343#else
344static inline int blk_iolatency_init(struct request_queue *q) { return 0; }
345#endif
346
347struct bio *blk_next_bio(struct bio *bio, unsigned int nr_pages, gfp_t gfp);
348
349#ifdef CONFIG_BLK_DEV_ZONED
350void blk_queue_free_zone_bitmaps(struct request_queue *q);
351#else
352static inline void blk_queue_free_zone_bitmaps(struct request_queue *q) {}
353#endif
354
355#endif /* BLK_INTERNAL_H */
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef BLK_INTERNAL_H
3#define BLK_INTERNAL_H
4
5#include <linux/idr.h>
6#include <linux/blk-mq.h>
7#include "blk-mq.h"
8
9/* Amount of time in which a process may batch requests */
10#define BLK_BATCH_TIME (HZ/50UL)
11
12/* Number of requests a "batching" process may submit */
13#define BLK_BATCH_REQ 32
14
15/* Max future timer expiry for timeouts */
16#define BLK_MAX_TIMEOUT (5 * HZ)
17
18#ifdef CONFIG_DEBUG_FS
19extern struct dentry *blk_debugfs_root;
20#endif
21
22struct 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;
30
31 /*
32 * flush_rq shares tag with this rq, both can't be active
33 * at the same time
34 */
35 struct request *orig_rq;
36 spinlock_t mq_flush_lock;
37};
38
39extern struct kmem_cache *blk_requestq_cachep;
40extern struct kmem_cache *request_cachep;
41extern struct kobj_type blk_queue_ktype;
42extern struct ida blk_queue_ida;
43
44/*
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().
50 */
51static inline void queue_lockdep_assert_held(struct request_queue *q)
52{
53 if (q->queue_lock)
54 lockdep_assert_held(q->queue_lock);
55}
56
57static inline void queue_flag_set_unlocked(unsigned int flag,
58 struct request_queue *q)
59{
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);
64}
65
66static inline void queue_flag_clear_unlocked(unsigned int flag,
67 struct request_queue *q)
68{
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);
73}
74
75static inline int queue_flag_test_and_clear(unsigned int flag,
76 struct request_queue *q)
77{
78 queue_lockdep_assert_held(q);
79
80 if (test_bit(flag, &q->queue_flags)) {
81 __clear_bit(flag, &q->queue_flags);
82 return 1;
83 }
84
85 return 0;
86}
87
88static inline int queue_flag_test_and_set(unsigned int flag,
89 struct request_queue *q)
90{
91 queue_lockdep_assert_held(q);
92
93 if (!test_bit(flag, &q->queue_flags)) {
94 __set_bit(flag, &q->queue_flags);
95 return 0;
96 }
97
98 return 1;
99}
100
101static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
102{
103 queue_lockdep_assert_held(q);
104 __set_bit(flag, &q->queue_flags);
105}
106
107static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
108{
109 queue_lockdep_assert_held(q);
110 __clear_bit(flag, &q->queue_flags);
111}
112
113static inline struct blk_flush_queue *blk_get_flush_queue(
114 struct request_queue *q, struct blk_mq_ctx *ctx)
115{
116 if (q->mq_ops)
117 return blk_mq_map_queue(q, ctx->cpu)->fq;
118 return q->fq;
119}
120
121static inline void __blk_get_queue(struct request_queue *q)
122{
123 kobject_get(&q->kobj);
124}
125
126struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
127 int node, int cmd_size);
128void blk_free_flush_queue(struct blk_flush_queue *q);
129
130int blk_init_rl(struct request_list *rl, struct request_queue *q,
131 gfp_t gfp_mask);
132void blk_exit_rl(struct request_queue *q, struct request_list *rl);
133void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
134 struct bio *bio);
135void blk_queue_bypass_start(struct request_queue *q);
136void blk_queue_bypass_end(struct request_queue *q);
137void __blk_queue_free_tags(struct request_queue *q);
138void blk_freeze_queue(struct request_queue *q);
139
140static inline void blk_queue_enter_live(struct request_queue *q)
141{
142 /*
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).
147 */
148 percpu_ref_get(&q->q_usage_counter);
149}
150
151#ifdef CONFIG_BLK_DEV_INTEGRITY
152void blk_flush_integrity(void);
153bool __bio_integrity_endio(struct bio *);
154static inline bool bio_integrity_endio(struct bio *bio)
155{
156 if (bio_integrity(bio))
157 return __bio_integrity_endio(bio);
158 return true;
159}
160#else
161static inline void blk_flush_integrity(void)
162{
163}
164static inline bool bio_integrity_endio(struct bio *bio)
165{
166 return true;
167}
168#endif
169
170void blk_timeout_work(struct work_struct *work);
171unsigned long blk_rq_timeout(unsigned long timeout);
172void blk_add_timer(struct request *req);
173void blk_delete_timer(struct request *);
174
175
176bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
177 struct bio *bio);
178bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
179 struct bio *bio);
180bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
181 struct bio *bio);
182bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
183 unsigned int *request_count,
184 struct request **same_queue_rq);
185unsigned int blk_plug_queued_count(struct request_queue *q);
186
187void blk_account_io_start(struct request *req, bool new_io);
188void blk_account_io_completion(struct request *req, unsigned int bytes);
189void blk_account_io_done(struct request *req);
190
191/*
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.
195 */
196static inline int blk_mark_rq_complete(struct request *rq)
197{
198 return test_and_set_bit(0, &rq->__deadline);
199}
200
201static inline void blk_clear_rq_complete(struct request *rq)
202{
203 clear_bit(0, &rq->__deadline);
204}
205
206static inline bool blk_rq_is_complete(struct request *rq)
207{
208 return test_bit(0, &rq->__deadline);
209}
210
211/*
212 * Internal elevator interface
213 */
214#define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
215
216void blk_insert_flush(struct request *rq);
217
218static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
219{
220 struct elevator_queue *e = q->elevator;
221
222 if (e->type->ops.sq.elevator_activate_req_fn)
223 e->type->ops.sq.elevator_activate_req_fn(q, rq);
224}
225
226static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
227{
228 struct elevator_queue *e = q->elevator;
229
230 if (e->type->ops.sq.elevator_deactivate_req_fn)
231 e->type->ops.sq.elevator_deactivate_req_fn(q, rq);
232}
233
234int elv_register_queue(struct request_queue *q);
235void elv_unregister_queue(struct request_queue *q);
236
237struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
238
239#ifdef CONFIG_FAIL_IO_TIMEOUT
240int blk_should_fake_timeout(struct request_queue *);
241ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
242ssize_t part_timeout_store(struct device *, struct device_attribute *,
243 const char *, size_t);
244#else
245static inline int blk_should_fake_timeout(struct request_queue *q)
246{
247 return 0;
248}
249#endif
250
251int ll_back_merge_fn(struct request_queue *q, struct request *req,
252 struct bio *bio);
253int ll_front_merge_fn(struct request_queue *q, struct request *req,
254 struct bio *bio);
255struct request *attempt_back_merge(struct request_queue *q, struct request *rq);
256struct request *attempt_front_merge(struct request_queue *q, struct request *rq);
257int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
258 struct request *next);
259void blk_recalc_rq_segments(struct request *rq);
260void blk_rq_set_mixed_merge(struct request *rq);
261bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
262enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
263
264void blk_queue_congestion_threshold(struct request_queue *q);
265
266int blk_dev_init(void);
267
268
269/*
270 * Return the threshold (number of used requests) at which the queue is
271 * considered to be congested. It include a little hysteresis to keep the
272 * context switch rate down.
273 */
274static inline int queue_congestion_on_threshold(struct request_queue *q)
275{
276 return q->nr_congestion_on;
277}
278
279/*
280 * The threshold at which a queue is considered to be uncongested
281 */
282static inline int queue_congestion_off_threshold(struct request_queue *q)
283{
284 return q->nr_congestion_off;
285}
286
287extern int blk_update_nr_requests(struct request_queue *, unsigned int);
288
289/*
290 * Contribute to IO statistics IFF:
291 *
292 * a) it's attached to a gendisk, and
293 * b) the queue had IO stats enabled when this request was started, and
294 * c) it's a file system request
295 */
296static inline int blk_do_io_stat(struct request *rq)
297{
298 return rq->rq_disk &&
299 (rq->rq_flags & RQF_IO_STAT) &&
300 !blk_rq_is_passthrough(rq);
301}
302
303static inline void req_set_nomerge(struct request_queue *q, struct request *req)
304{
305 req->cmd_flags |= REQ_NOMERGE;
306 if (req == q->last_merge)
307 q->last_merge = NULL;
308}
309
310/*
311 * Steal a bit from this field for legacy IO path atomic IO marking. Note that
312 * setting the deadline clears the bottom bit, potentially clearing the
313 * completed bit. The user has to be OK with this (current ones are fine).
314 */
315static inline void blk_rq_set_deadline(struct request *rq, unsigned long time)
316{
317 rq->__deadline = time & ~0x1UL;
318}
319
320static inline unsigned long blk_rq_deadline(struct request *rq)
321{
322 return rq->__deadline & ~0x1UL;
323}
324
325/*
326 * Internal io_context interface
327 */
328void get_io_context(struct io_context *ioc);
329struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
330struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
331 gfp_t gfp_mask);
332void ioc_clear_queue(struct request_queue *q);
333
334int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
335
336/**
337 * rq_ioc - determine io_context for request allocation
338 * @bio: request being allocated is for this bio (can be %NULL)
339 *
340 * Determine io_context to use for request allocation for @bio. May return
341 * %NULL if %current->io_context doesn't exist.
342 */
343static inline struct io_context *rq_ioc(struct bio *bio)
344{
345#ifdef CONFIG_BLK_CGROUP
346 if (bio && bio->bi_ioc)
347 return bio->bi_ioc;
348#endif
349 return current->io_context;
350}
351
352/**
353 * create_io_context - try to create task->io_context
354 * @gfp_mask: allocation mask
355 * @node: allocation node
356 *
357 * If %current->io_context is %NULL, allocate a new io_context and install
358 * it. Returns the current %current->io_context which may be %NULL if
359 * allocation failed.
360 *
361 * Note that this function can't be called with IRQ disabled because
362 * task_lock which protects %current->io_context is IRQ-unsafe.
363 */
364static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
365{
366 WARN_ON_ONCE(irqs_disabled());
367 if (unlikely(!current->io_context))
368 create_task_io_context(current, gfp_mask, node);
369 return current->io_context;
370}
371
372/*
373 * Internal throttling interface
374 */
375#ifdef CONFIG_BLK_DEV_THROTTLING
376extern void blk_throtl_drain(struct request_queue *q);
377extern int blk_throtl_init(struct request_queue *q);
378extern void blk_throtl_exit(struct request_queue *q);
379extern void blk_throtl_register_queue(struct request_queue *q);
380#else /* CONFIG_BLK_DEV_THROTTLING */
381static inline void blk_throtl_drain(struct request_queue *q) { }
382static inline int blk_throtl_init(struct request_queue *q) { return 0; }
383static inline void blk_throtl_exit(struct request_queue *q) { }
384static inline void blk_throtl_register_queue(struct request_queue *q) { }
385#endif /* CONFIG_BLK_DEV_THROTTLING */
386#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
387extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
388extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
389 const char *page, size_t count);
390extern void blk_throtl_bio_endio(struct bio *bio);
391extern void blk_throtl_stat_add(struct request *rq, u64 time);
392#else
393static inline void blk_throtl_bio_endio(struct bio *bio) { }
394static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
395#endif
396
397#ifdef CONFIG_BOUNCE
398extern int init_emergency_isa_pool(void);
399extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
400#else
401static inline int init_emergency_isa_pool(void)
402{
403 return 0;
404}
405static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
406{
407}
408#endif /* CONFIG_BOUNCE */
409
410extern void blk_drain_queue(struct request_queue *q);
411
412#endif /* BLK_INTERNAL_H */