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1#ifndef BLK_INTERNAL_H
2#define BLK_INTERNAL_H
3
4#include <linux/idr.h>
5
6/* Amount of time in which a process may batch requests */
7#define BLK_BATCH_TIME (HZ/50UL)
8
9/* Number of requests a "batching" process may submit */
10#define BLK_BATCH_REQ 32
11
12extern struct kmem_cache *blk_requestq_cachep;
13extern struct kmem_cache *request_cachep;
14extern struct kobj_type blk_queue_ktype;
15extern struct ida blk_queue_ida;
16
17static inline void __blk_get_queue(struct request_queue *q)
18{
19 kobject_get(&q->kobj);
20}
21
22int blk_init_rl(struct request_list *rl, struct request_queue *q,
23 gfp_t gfp_mask);
24void blk_exit_rl(struct request_list *rl);
25void init_request_from_bio(struct request *req, struct bio *bio);
26void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
27 struct bio *bio);
28int blk_rq_append_bio(struct request_queue *q, struct request *rq,
29 struct bio *bio);
30void blk_queue_bypass_start(struct request_queue *q);
31void blk_queue_bypass_end(struct request_queue *q);
32void blk_dequeue_request(struct request *rq);
33void __blk_queue_free_tags(struct request_queue *q);
34bool __blk_end_bidi_request(struct request *rq, int error,
35 unsigned int nr_bytes, unsigned int bidi_bytes);
36
37void blk_rq_timed_out_timer(unsigned long data);
38void blk_rq_check_expired(struct request *rq, unsigned long *next_timeout,
39 unsigned int *next_set);
40void __blk_add_timer(struct request *req, struct list_head *timeout_list);
41void blk_delete_timer(struct request *);
42void blk_add_timer(struct request *);
43
44
45bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
46 struct bio *bio);
47bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
48 struct bio *bio);
49bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
50 unsigned int *request_count);
51
52void blk_account_io_start(struct request *req, bool new_io);
53void blk_account_io_completion(struct request *req, unsigned int bytes);
54void blk_account_io_done(struct request *req);
55
56/*
57 * Internal atomic flags for request handling
58 */
59enum rq_atomic_flags {
60 REQ_ATOM_COMPLETE = 0,
61 REQ_ATOM_STARTED,
62};
63
64/*
65 * EH timer and IO completion will both attempt to 'grab' the request, make
66 * sure that only one of them succeeds
67 */
68static inline int blk_mark_rq_complete(struct request *rq)
69{
70 return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
71}
72
73static inline void blk_clear_rq_complete(struct request *rq)
74{
75 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
76}
77
78/*
79 * Internal elevator interface
80 */
81#define ELV_ON_HASH(rq) ((rq)->cmd_flags & REQ_HASHED)
82
83void blk_insert_flush(struct request *rq);
84void blk_abort_flushes(struct request_queue *q);
85
86static inline struct request *__elv_next_request(struct request_queue *q)
87{
88 struct request *rq;
89
90 while (1) {
91 if (!list_empty(&q->queue_head)) {
92 rq = list_entry_rq(q->queue_head.next);
93 return rq;
94 }
95
96 /*
97 * Flush request is running and flush request isn't queueable
98 * in the drive, we can hold the queue till flush request is
99 * finished. Even we don't do this, driver can't dispatch next
100 * requests and will requeue them. And this can improve
101 * throughput too. For example, we have request flush1, write1,
102 * flush 2. flush1 is dispatched, then queue is hold, write1
103 * isn't inserted to queue. After flush1 is finished, flush2
104 * will be dispatched. Since disk cache is already clean,
105 * flush2 will be finished very soon, so looks like flush2 is
106 * folded to flush1.
107 * Since the queue is hold, a flag is set to indicate the queue
108 * should be restarted later. Please see flush_end_io() for
109 * details.
110 */
111 if (q->flush_pending_idx != q->flush_running_idx &&
112 !queue_flush_queueable(q)) {
113 q->flush_queue_delayed = 1;
114 return NULL;
115 }
116 if (unlikely(blk_queue_bypass(q)) ||
117 !q->elevator->type->ops.elevator_dispatch_fn(q, 0))
118 return NULL;
119 }
120}
121
122static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
123{
124 struct elevator_queue *e = q->elevator;
125
126 if (e->type->ops.elevator_activate_req_fn)
127 e->type->ops.elevator_activate_req_fn(q, rq);
128}
129
130static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
131{
132 struct elevator_queue *e = q->elevator;
133
134 if (e->type->ops.elevator_deactivate_req_fn)
135 e->type->ops.elevator_deactivate_req_fn(q, rq);
136}
137
138#ifdef CONFIG_FAIL_IO_TIMEOUT
139int blk_should_fake_timeout(struct request_queue *);
140ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
141ssize_t part_timeout_store(struct device *, struct device_attribute *,
142 const char *, size_t);
143#else
144static inline int blk_should_fake_timeout(struct request_queue *q)
145{
146 return 0;
147}
148#endif
149
150int ll_back_merge_fn(struct request_queue *q, struct request *req,
151 struct bio *bio);
152int ll_front_merge_fn(struct request_queue *q, struct request *req,
153 struct bio *bio);
154int attempt_back_merge(struct request_queue *q, struct request *rq);
155int attempt_front_merge(struct request_queue *q, struct request *rq);
156int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
157 struct request *next);
158void blk_recalc_rq_segments(struct request *rq);
159void blk_rq_set_mixed_merge(struct request *rq);
160bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
161int blk_try_merge(struct request *rq, struct bio *bio);
162
163void blk_queue_congestion_threshold(struct request_queue *q);
164
165void __blk_run_queue_uncond(struct request_queue *q);
166
167int blk_dev_init(void);
168
169
170/*
171 * Return the threshold (number of used requests) at which the queue is
172 * considered to be congested. It include a little hysteresis to keep the
173 * context switch rate down.
174 */
175static inline int queue_congestion_on_threshold(struct request_queue *q)
176{
177 return q->nr_congestion_on;
178}
179
180/*
181 * The threshold at which a queue is considered to be uncongested
182 */
183static inline int queue_congestion_off_threshold(struct request_queue *q)
184{
185 return q->nr_congestion_off;
186}
187
188/*
189 * Contribute to IO statistics IFF:
190 *
191 * a) it's attached to a gendisk, and
192 * b) the queue had IO stats enabled when this request was started, and
193 * c) it's a file system request
194 */
195static inline int blk_do_io_stat(struct request *rq)
196{
197 return rq->rq_disk &&
198 (rq->cmd_flags & REQ_IO_STAT) &&
199 (rq->cmd_type == REQ_TYPE_FS);
200}
201
202/*
203 * Internal io_context interface
204 */
205void get_io_context(struct io_context *ioc);
206struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
207struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
208 gfp_t gfp_mask);
209void ioc_clear_queue(struct request_queue *q);
210
211int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
212
213/**
214 * create_io_context - try to create task->io_context
215 * @gfp_mask: allocation mask
216 * @node: allocation node
217 *
218 * If %current->io_context is %NULL, allocate a new io_context and install
219 * it. Returns the current %current->io_context which may be %NULL if
220 * allocation failed.
221 *
222 * Note that this function can't be called with IRQ disabled because
223 * task_lock which protects %current->io_context is IRQ-unsafe.
224 */
225static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
226{
227 WARN_ON_ONCE(irqs_disabled());
228 if (unlikely(!current->io_context))
229 create_task_io_context(current, gfp_mask, node);
230 return current->io_context;
231}
232
233/*
234 * Internal throttling interface
235 */
236#ifdef CONFIG_BLK_DEV_THROTTLING
237extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio);
238extern void blk_throtl_drain(struct request_queue *q);
239extern int blk_throtl_init(struct request_queue *q);
240extern void blk_throtl_exit(struct request_queue *q);
241#else /* CONFIG_BLK_DEV_THROTTLING */
242static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio)
243{
244 return false;
245}
246static inline void blk_throtl_drain(struct request_queue *q) { }
247static inline int blk_throtl_init(struct request_queue *q) { return 0; }
248static inline void blk_throtl_exit(struct request_queue *q) { }
249#endif /* CONFIG_BLK_DEV_THROTTLING */
250
251#endif /* BLK_INTERNAL_H */
1#ifndef BLK_INTERNAL_H
2#define BLK_INTERNAL_H
3
4#include <linux/idr.h>
5
6/* Amount of time in which a process may batch requests */
7#define BLK_BATCH_TIME (HZ/50UL)
8
9/* Number of requests a "batching" process may submit */
10#define BLK_BATCH_REQ 32
11
12extern struct kmem_cache *blk_requestq_cachep;
13extern struct kobj_type blk_queue_ktype;
14extern struct ida blk_queue_ida;
15
16static inline void __blk_get_queue(struct request_queue *q)
17{
18 kobject_get(&q->kobj);
19}
20
21void init_request_from_bio(struct request *req, struct bio *bio);
22void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
23 struct bio *bio);
24int blk_rq_append_bio(struct request_queue *q, struct request *rq,
25 struct bio *bio);
26void blk_queue_bypass_start(struct request_queue *q);
27void blk_queue_bypass_end(struct request_queue *q);
28void blk_dequeue_request(struct request *rq);
29void __blk_queue_free_tags(struct request_queue *q);
30bool __blk_end_bidi_request(struct request *rq, int error,
31 unsigned int nr_bytes, unsigned int bidi_bytes);
32
33void blk_rq_timed_out_timer(unsigned long data);
34void blk_delete_timer(struct request *);
35void blk_add_timer(struct request *);
36void __generic_unplug_device(struct request_queue *);
37
38/*
39 * Internal atomic flags for request handling
40 */
41enum rq_atomic_flags {
42 REQ_ATOM_COMPLETE = 0,
43};
44
45/*
46 * EH timer and IO completion will both attempt to 'grab' the request, make
47 * sure that only one of them succeeds
48 */
49static inline int blk_mark_rq_complete(struct request *rq)
50{
51 return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
52}
53
54static inline void blk_clear_rq_complete(struct request *rq)
55{
56 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
57}
58
59/*
60 * Internal elevator interface
61 */
62#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash))
63
64void blk_insert_flush(struct request *rq);
65void blk_abort_flushes(struct request_queue *q);
66
67static inline struct request *__elv_next_request(struct request_queue *q)
68{
69 struct request *rq;
70
71 while (1) {
72 if (!list_empty(&q->queue_head)) {
73 rq = list_entry_rq(q->queue_head.next);
74 return rq;
75 }
76
77 /*
78 * Flush request is running and flush request isn't queueable
79 * in the drive, we can hold the queue till flush request is
80 * finished. Even we don't do this, driver can't dispatch next
81 * requests and will requeue them. And this can improve
82 * throughput too. For example, we have request flush1, write1,
83 * flush 2. flush1 is dispatched, then queue is hold, write1
84 * isn't inserted to queue. After flush1 is finished, flush2
85 * will be dispatched. Since disk cache is already clean,
86 * flush2 will be finished very soon, so looks like flush2 is
87 * folded to flush1.
88 * Since the queue is hold, a flag is set to indicate the queue
89 * should be restarted later. Please see flush_end_io() for
90 * details.
91 */
92 if (q->flush_pending_idx != q->flush_running_idx &&
93 !queue_flush_queueable(q)) {
94 q->flush_queue_delayed = 1;
95 return NULL;
96 }
97 if (unlikely(blk_queue_dead(q)) ||
98 !q->elevator->type->ops.elevator_dispatch_fn(q, 0))
99 return NULL;
100 }
101}
102
103static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
104{
105 struct elevator_queue *e = q->elevator;
106
107 if (e->type->ops.elevator_activate_req_fn)
108 e->type->ops.elevator_activate_req_fn(q, rq);
109}
110
111static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
112{
113 struct elevator_queue *e = q->elevator;
114
115 if (e->type->ops.elevator_deactivate_req_fn)
116 e->type->ops.elevator_deactivate_req_fn(q, rq);
117}
118
119#ifdef CONFIG_FAIL_IO_TIMEOUT
120int blk_should_fake_timeout(struct request_queue *);
121ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
122ssize_t part_timeout_store(struct device *, struct device_attribute *,
123 const char *, size_t);
124#else
125static inline int blk_should_fake_timeout(struct request_queue *q)
126{
127 return 0;
128}
129#endif
130
131int ll_back_merge_fn(struct request_queue *q, struct request *req,
132 struct bio *bio);
133int ll_front_merge_fn(struct request_queue *q, struct request *req,
134 struct bio *bio);
135int attempt_back_merge(struct request_queue *q, struct request *rq);
136int attempt_front_merge(struct request_queue *q, struct request *rq);
137int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
138 struct request *next);
139void blk_recalc_rq_segments(struct request *rq);
140void blk_rq_set_mixed_merge(struct request *rq);
141bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
142int blk_try_merge(struct request *rq, struct bio *bio);
143
144void blk_queue_congestion_threshold(struct request_queue *q);
145
146int blk_dev_init(void);
147
148
149/*
150 * Return the threshold (number of used requests) at which the queue is
151 * considered to be congested. It include a little hysteresis to keep the
152 * context switch rate down.
153 */
154static inline int queue_congestion_on_threshold(struct request_queue *q)
155{
156 return q->nr_congestion_on;
157}
158
159/*
160 * The threshold at which a queue is considered to be uncongested
161 */
162static inline int queue_congestion_off_threshold(struct request_queue *q)
163{
164 return q->nr_congestion_off;
165}
166
167/*
168 * Contribute to IO statistics IFF:
169 *
170 * a) it's attached to a gendisk, and
171 * b) the queue had IO stats enabled when this request was started, and
172 * c) it's a file system request or a discard request
173 */
174static inline int blk_do_io_stat(struct request *rq)
175{
176 return rq->rq_disk &&
177 (rq->cmd_flags & REQ_IO_STAT) &&
178 (rq->cmd_type == REQ_TYPE_FS ||
179 (rq->cmd_flags & REQ_DISCARD));
180}
181
182/*
183 * Internal io_context interface
184 */
185void get_io_context(struct io_context *ioc);
186struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
187struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
188 gfp_t gfp_mask);
189void ioc_clear_queue(struct request_queue *q);
190
191int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
192
193/**
194 * create_io_context - try to create task->io_context
195 * @gfp_mask: allocation mask
196 * @node: allocation node
197 *
198 * If %current->io_context is %NULL, allocate a new io_context and install
199 * it. Returns the current %current->io_context which may be %NULL if
200 * allocation failed.
201 *
202 * Note that this function can't be called with IRQ disabled because
203 * task_lock which protects %current->io_context is IRQ-unsafe.
204 */
205static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
206{
207 WARN_ON_ONCE(irqs_disabled());
208 if (unlikely(!current->io_context))
209 create_task_io_context(current, gfp_mask, node);
210 return current->io_context;
211}
212
213/*
214 * Internal throttling interface
215 */
216#ifdef CONFIG_BLK_DEV_THROTTLING
217extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio);
218extern void blk_throtl_drain(struct request_queue *q);
219extern int blk_throtl_init(struct request_queue *q);
220extern void blk_throtl_exit(struct request_queue *q);
221#else /* CONFIG_BLK_DEV_THROTTLING */
222static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio)
223{
224 return false;
225}
226static inline void blk_throtl_drain(struct request_queue *q) { }
227static inline int blk_throtl_init(struct request_queue *q) { return 0; }
228static inline void blk_throtl_exit(struct request_queue *q) { }
229#endif /* CONFIG_BLK_DEV_THROTTLING */
230
231#endif /* BLK_INTERNAL_H */