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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 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 */
1#ifndef BLK_INTERNAL_H
2#define BLK_INTERNAL_H
3
4/* Amount of time in which a process may batch requests */
5#define BLK_BATCH_TIME (HZ/50UL)
6
7/* Number of requests a "batching" process may submit */
8#define BLK_BATCH_REQ 32
9
10extern struct kmem_cache *blk_requestq_cachep;
11extern struct kobj_type blk_queue_ktype;
12
13void init_request_from_bio(struct request *req, struct bio *bio);
14void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
15 struct bio *bio);
16int blk_rq_append_bio(struct request_queue *q, struct request *rq,
17 struct bio *bio);
18void blk_dequeue_request(struct request *rq);
19void __blk_queue_free_tags(struct request_queue *q);
20bool __blk_end_bidi_request(struct request *rq, int error,
21 unsigned int nr_bytes, unsigned int bidi_bytes);
22
23void blk_rq_timed_out_timer(unsigned long data);
24void blk_delete_timer(struct request *);
25void blk_add_timer(struct request *);
26void __generic_unplug_device(struct request_queue *);
27
28/*
29 * Internal atomic flags for request handling
30 */
31enum rq_atomic_flags {
32 REQ_ATOM_COMPLETE = 0,
33};
34
35/*
36 * EH timer and IO completion will both attempt to 'grab' the request, make
37 * sure that only one of them succeeds
38 */
39static inline int blk_mark_rq_complete(struct request *rq)
40{
41 return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
42}
43
44static inline void blk_clear_rq_complete(struct request *rq)
45{
46 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
47}
48
49/*
50 * Internal elevator interface
51 */
52#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash))
53
54void blk_insert_flush(struct request *rq);
55void blk_abort_flushes(struct request_queue *q);
56
57static inline struct request *__elv_next_request(struct request_queue *q)
58{
59 struct request *rq;
60
61 while (1) {
62 if (!list_empty(&q->queue_head)) {
63 rq = list_entry_rq(q->queue_head.next);
64 return rq;
65 }
66
67 /*
68 * Flush request is running and flush request isn't queueable
69 * in the drive, we can hold the queue till flush request is
70 * finished. Even we don't do this, driver can't dispatch next
71 * requests and will requeue them. And this can improve
72 * throughput too. For example, we have request flush1, write1,
73 * flush 2. flush1 is dispatched, then queue is hold, write1
74 * isn't inserted to queue. After flush1 is finished, flush2
75 * will be dispatched. Since disk cache is already clean,
76 * flush2 will be finished very soon, so looks like flush2 is
77 * folded to flush1.
78 * Since the queue is hold, a flag is set to indicate the queue
79 * should be restarted later. Please see flush_end_io() for
80 * details.
81 */
82 if (q->flush_pending_idx != q->flush_running_idx &&
83 !queue_flush_queueable(q)) {
84 q->flush_queue_delayed = 1;
85 return NULL;
86 }
87 if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags) ||
88 !q->elevator->ops->elevator_dispatch_fn(q, 0))
89 return NULL;
90 }
91}
92
93static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
94{
95 struct elevator_queue *e = q->elevator;
96
97 if (e->ops->elevator_activate_req_fn)
98 e->ops->elevator_activate_req_fn(q, rq);
99}
100
101static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
102{
103 struct elevator_queue *e = q->elevator;
104
105 if (e->ops->elevator_deactivate_req_fn)
106 e->ops->elevator_deactivate_req_fn(q, rq);
107}
108
109#ifdef CONFIG_FAIL_IO_TIMEOUT
110int blk_should_fake_timeout(struct request_queue *);
111ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
112ssize_t part_timeout_store(struct device *, struct device_attribute *,
113 const char *, size_t);
114#else
115static inline int blk_should_fake_timeout(struct request_queue *q)
116{
117 return 0;
118}
119#endif
120
121struct io_context *current_io_context(gfp_t gfp_flags, int node);
122
123int ll_back_merge_fn(struct request_queue *q, struct request *req,
124 struct bio *bio);
125int ll_front_merge_fn(struct request_queue *q, struct request *req,
126 struct bio *bio);
127int attempt_back_merge(struct request_queue *q, struct request *rq);
128int attempt_front_merge(struct request_queue *q, struct request *rq);
129int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
130 struct request *next);
131void blk_recalc_rq_segments(struct request *rq);
132void blk_rq_set_mixed_merge(struct request *rq);
133
134void blk_queue_congestion_threshold(struct request_queue *q);
135
136int blk_dev_init(void);
137
138void elv_quiesce_start(struct request_queue *q);
139void elv_quiesce_end(struct request_queue *q);
140
141
142/*
143 * Return the threshold (number of used requests) at which the queue is
144 * considered to be congested. It include a little hysteresis to keep the
145 * context switch rate down.
146 */
147static inline int queue_congestion_on_threshold(struct request_queue *q)
148{
149 return q->nr_congestion_on;
150}
151
152/*
153 * The threshold at which a queue is considered to be uncongested
154 */
155static inline int queue_congestion_off_threshold(struct request_queue *q)
156{
157 return q->nr_congestion_off;
158}
159
160static inline int blk_cpu_to_group(int cpu)
161{
162 int group = NR_CPUS;
163#ifdef CONFIG_SCHED_MC
164 const struct cpumask *mask = cpu_coregroup_mask(cpu);
165 group = cpumask_first(mask);
166#elif defined(CONFIG_SCHED_SMT)
167 group = cpumask_first(topology_thread_cpumask(cpu));
168#else
169 return cpu;
170#endif
171 if (likely(group < NR_CPUS))
172 return group;
173 return cpu;
174}
175
176/*
177 * Contribute to IO statistics IFF:
178 *
179 * a) it's attached to a gendisk, and
180 * b) the queue had IO stats enabled when this request was started, and
181 * c) it's a file system request or a discard request
182 */
183static inline int blk_do_io_stat(struct request *rq)
184{
185 return rq->rq_disk &&
186 (rq->cmd_flags & REQ_IO_STAT) &&
187 (rq->cmd_type == REQ_TYPE_FS ||
188 (rq->cmd_flags & REQ_DISCARD));
189}
190
191#endif