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8324aa91 JA |
1 | #ifndef BLK_INTERNAL_H |
2 | #define BLK_INTERNAL_H | |
3 | ||
a73f730d TH |
4 | #include <linux/idr.h> |
5 | ||
86db1e29 JA |
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 | ||
8324aa91 JA |
12 | extern struct kmem_cache *blk_requestq_cachep; |
13 | extern struct kobj_type blk_queue_ktype; | |
a73f730d | 14 | extern struct ida blk_queue_ida; |
8324aa91 | 15 | |
09ac46c4 TH |
16 | static inline void __blk_get_queue(struct request_queue *q) |
17 | { | |
18 | kobject_get(&q->kobj); | |
19 | } | |
20 | ||
86db1e29 JA |
21 | void init_request_from_bio(struct request *req, struct bio *bio); |
22 | void blk_rq_bio_prep(struct request_queue *q, struct request *rq, | |
23 | struct bio *bio); | |
a411f4bb BH |
24 | int blk_rq_append_bio(struct request_queue *q, struct request *rq, |
25 | struct bio *bio); | |
d732580b TH |
26 | void blk_queue_bypass_start(struct request_queue *q); |
27 | void blk_queue_bypass_end(struct request_queue *q); | |
9934c8c0 | 28 | void blk_dequeue_request(struct request *rq); |
8324aa91 | 29 | void __blk_queue_free_tags(struct request_queue *q); |
4853abaa JM |
30 | bool __blk_end_bidi_request(struct request *rq, int error, |
31 | unsigned int nr_bytes, unsigned int bidi_bytes); | |
8324aa91 | 32 | |
242f9dcb JA |
33 | void blk_rq_timed_out_timer(unsigned long data); |
34 | void blk_delete_timer(struct request *); | |
35 | void blk_add_timer(struct request *); | |
f73e2d13 | 36 | void __generic_unplug_device(struct request_queue *); |
242f9dcb JA |
37 | |
38 | /* | |
39 | * Internal atomic flags for request handling | |
40 | */ | |
41 | enum 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 | |
25985edc | 47 | * sure that only one of them succeeds |
242f9dcb JA |
48 | */ |
49 | static inline int blk_mark_rq_complete(struct request *rq) | |
50 | { | |
51 | return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); | |
52 | } | |
53 | ||
54 | static inline void blk_clear_rq_complete(struct request *rq) | |
55 | { | |
56 | clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); | |
57 | } | |
86db1e29 | 58 | |
158dbda0 TH |
59 | /* |
60 | * Internal elevator interface | |
61 | */ | |
62 | #define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash)) | |
63 | ||
ae1b1539 TH |
64 | void blk_insert_flush(struct request *rq); |
65 | void blk_abort_flushes(struct request_queue *q); | |
dd831006 | 66 | |
158dbda0 TH |
67 | static inline struct request *__elv_next_request(struct request_queue *q) |
68 | { | |
69 | struct request *rq; | |
70 | ||
71 | while (1) { | |
ae1b1539 | 72 | if (!list_empty(&q->queue_head)) { |
158dbda0 | 73 | rq = list_entry_rq(q->queue_head.next); |
ae1b1539 | 74 | return rq; |
158dbda0 TH |
75 | } |
76 | ||
3ac0cc45 | 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 | } | |
34f6055c | 97 | if (unlikely(blk_queue_dead(q)) || |
22f746e2 | 98 | !q->elevator->type->ops.elevator_dispatch_fn(q, 0)) |
158dbda0 TH |
99 | return NULL; |
100 | } | |
101 | } | |
102 | ||
103 | static inline void elv_activate_rq(struct request_queue *q, struct request *rq) | |
104 | { | |
105 | struct elevator_queue *e = q->elevator; | |
106 | ||
22f746e2 TH |
107 | if (e->type->ops.elevator_activate_req_fn) |
108 | e->type->ops.elevator_activate_req_fn(q, rq); | |
158dbda0 TH |
109 | } |
110 | ||
111 | static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq) | |
112 | { | |
113 | struct elevator_queue *e = q->elevator; | |
114 | ||
22f746e2 TH |
115 | if (e->type->ops.elevator_deactivate_req_fn) |
116 | e->type->ops.elevator_deactivate_req_fn(q, rq); | |
158dbda0 TH |
117 | } |
118 | ||
581d4e28 JA |
119 | #ifdef CONFIG_FAIL_IO_TIMEOUT |
120 | int blk_should_fake_timeout(struct request_queue *); | |
121 | ssize_t part_timeout_show(struct device *, struct device_attribute *, char *); | |
122 | ssize_t part_timeout_store(struct device *, struct device_attribute *, | |
123 | const char *, size_t); | |
124 | #else | |
125 | static inline int blk_should_fake_timeout(struct request_queue *q) | |
126 | { | |
127 | return 0; | |
128 | } | |
129 | #endif | |
130 | ||
d6d48196 JA |
131 | int ll_back_merge_fn(struct request_queue *q, struct request *req, |
132 | struct bio *bio); | |
133 | int ll_front_merge_fn(struct request_queue *q, struct request *req, | |
134 | struct bio *bio); | |
135 | int attempt_back_merge(struct request_queue *q, struct request *rq); | |
136 | int attempt_front_merge(struct request_queue *q, struct request *rq); | |
5e84ea3a JA |
137 | int blk_attempt_req_merge(struct request_queue *q, struct request *rq, |
138 | struct request *next); | |
d6d48196 | 139 | void blk_recalc_rq_segments(struct request *rq); |
80a761fd | 140 | void blk_rq_set_mixed_merge(struct request *rq); |
050c8ea8 TH |
141 | bool blk_rq_merge_ok(struct request *rq, struct bio *bio); |
142 | int blk_try_merge(struct request *rq, struct bio *bio); | |
d6d48196 | 143 | |
8324aa91 JA |
144 | void blk_queue_congestion_threshold(struct request_queue *q); |
145 | ||
ff88972c AB |
146 | int blk_dev_init(void); |
147 | ||
f253b86b | 148 | |
8324aa91 JA |
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 | */ | |
154 | static 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 | */ | |
162 | static inline int queue_congestion_off_threshold(struct request_queue *q) | |
163 | { | |
164 | return q->nr_congestion_off; | |
165 | } | |
166 | ||
c2553b58 JA |
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 | |
3c4198e8 | 172 | * c) it's a file system request or a discard request |
c2553b58 | 173 | */ |
26308eab | 174 | static inline int blk_do_io_stat(struct request *rq) |
fb8ec18c | 175 | { |
33659ebb CH |
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)); | |
fb8ec18c JA |
180 | } |
181 | ||
f2dbd76a TH |
182 | /* |
183 | * Internal io_context interface | |
184 | */ | |
185 | void get_io_context(struct io_context *ioc); | |
47fdd4ca | 186 | struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q); |
24acfc34 TH |
187 | struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q, |
188 | gfp_t gfp_mask); | |
7e5a8794 | 189 | void ioc_clear_queue(struct request_queue *q); |
f2dbd76a | 190 | |
24acfc34 | 191 | int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node); |
f2dbd76a TH |
192 | |
193 | /** | |
194 | * create_io_context - try to create task->io_context | |
f2dbd76a TH |
195 | * @gfp_mask: allocation mask |
196 | * @node: allocation node | |
197 | * | |
24acfc34 TH |
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. | |
f2dbd76a TH |
201 | * |
202 | * Note that this function can't be called with IRQ disabled because | |
24acfc34 | 203 | * task_lock which protects %current->io_context is IRQ-unsafe. |
f2dbd76a | 204 | */ |
24acfc34 | 205 | static inline struct io_context *create_io_context(gfp_t gfp_mask, int node) |
f2dbd76a TH |
206 | { |
207 | WARN_ON_ONCE(irqs_disabled()); | |
24acfc34 TH |
208 | if (unlikely(!current->io_context)) |
209 | create_task_io_context(current, gfp_mask, node); | |
210 | return current->io_context; | |
f2dbd76a TH |
211 | } |
212 | ||
213 | /* | |
214 | * Internal throttling interface | |
215 | */ | |
bc9fcbf9 | 216 | #ifdef CONFIG_BLK_DEV_THROTTLING |
bc16a4f9 | 217 | extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio); |
c9a929dd | 218 | extern void blk_throtl_drain(struct request_queue *q); |
bc9fcbf9 TH |
219 | extern int blk_throtl_init(struct request_queue *q); |
220 | extern void blk_throtl_exit(struct request_queue *q); | |
221 | #else /* CONFIG_BLK_DEV_THROTTLING */ | |
bc16a4f9 | 222 | static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio) |
bc9fcbf9 | 223 | { |
bc16a4f9 | 224 | return false; |
bc9fcbf9 | 225 | } |
c9a929dd | 226 | static inline void blk_throtl_drain(struct request_queue *q) { } |
bc9fcbf9 TH |
227 | static inline int blk_throtl_init(struct request_queue *q) { return 0; } |
228 | static inline void blk_throtl_exit(struct request_queue *q) { } | |
229 | #endif /* CONFIG_BLK_DEV_THROTTLING */ | |
230 | ||
231 | #endif /* BLK_INTERNAL_H */ |