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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 | ||
12 | /* Max future timer expiry for timeouts */ | |
13 | #define BLK_MAX_TIMEOUT (5 * HZ) | |
14 | ||
15 | extern struct kmem_cache *blk_requestq_cachep; | |
16 | extern struct kmem_cache *request_cachep; | |
17 | extern struct kobj_type blk_queue_ktype; | |
18 | extern struct ida blk_queue_ida; | |
19 | ||
20 | static inline void __blk_get_queue(struct request_queue *q) | |
21 | { | |
22 | kobject_get(&q->kobj); | |
23 | } | |
24 | ||
25 | int blk_init_rl(struct request_list *rl, struct request_queue *q, | |
26 | gfp_t gfp_mask); | |
27 | void blk_exit_rl(struct request_list *rl); | |
28 | void init_request_from_bio(struct request *req, struct bio *bio); | |
29 | void blk_rq_bio_prep(struct request_queue *q, struct request *rq, | |
30 | struct bio *bio); | |
31 | int blk_rq_append_bio(struct request_queue *q, struct request *rq, | |
32 | struct bio *bio); | |
33 | void blk_queue_bypass_start(struct request_queue *q); | |
34 | void blk_queue_bypass_end(struct request_queue *q); | |
35 | void blk_dequeue_request(struct request *rq); | |
36 | void __blk_queue_free_tags(struct request_queue *q); | |
37 | bool __blk_end_bidi_request(struct request *rq, int error, | |
38 | unsigned int nr_bytes, unsigned int bidi_bytes); | |
39 | ||
40 | void blk_rq_timed_out_timer(unsigned long data); | |
41 | unsigned long blk_rq_timeout(unsigned long timeout); | |
42 | void blk_add_timer(struct request *req); | |
43 | void blk_delete_timer(struct request *); | |
44 | ||
45 | ||
46 | bool bio_attempt_front_merge(struct request_queue *q, struct request *req, | |
47 | struct bio *bio); | |
48 | bool bio_attempt_back_merge(struct request_queue *q, struct request *req, | |
49 | struct bio *bio); | |
50 | bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, | |
51 | unsigned int *request_count); | |
52 | ||
53 | void blk_account_io_start(struct request *req, bool new_io); | |
54 | void blk_account_io_completion(struct request *req, unsigned int bytes); | |
55 | void blk_account_io_done(struct request *req); | |
56 | ||
57 | /* | |
58 | * Internal atomic flags for request handling | |
59 | */ | |
60 | enum rq_atomic_flags { | |
61 | REQ_ATOM_COMPLETE = 0, | |
62 | REQ_ATOM_STARTED, | |
63 | }; | |
64 | ||
65 | /* | |
66 | * EH timer and IO completion will both attempt to 'grab' the request, make | |
67 | * sure that only one of them succeeds | |
68 | */ | |
69 | static inline int blk_mark_rq_complete(struct request *rq) | |
70 | { | |
71 | return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); | |
72 | } | |
73 | ||
74 | static inline void blk_clear_rq_complete(struct request *rq) | |
75 | { | |
76 | clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); | |
77 | } | |
78 | ||
79 | /* | |
80 | * Internal elevator interface | |
81 | */ | |
82 | #define ELV_ON_HASH(rq) ((rq)->cmd_flags & REQ_HASHED) | |
83 | ||
84 | void blk_insert_flush(struct request *rq); | |
85 | ||
86 | static 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 | ||
122 | static 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 | ||
130 | static 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 | |
139 | int blk_should_fake_timeout(struct request_queue *); | |
140 | ssize_t part_timeout_show(struct device *, struct device_attribute *, char *); | |
141 | ssize_t part_timeout_store(struct device *, struct device_attribute *, | |
142 | const char *, size_t); | |
143 | #else | |
144 | static inline int blk_should_fake_timeout(struct request_queue *q) | |
145 | { | |
146 | return 0; | |
147 | } | |
148 | #endif | |
149 | ||
150 | int ll_back_merge_fn(struct request_queue *q, struct request *req, | |
151 | struct bio *bio); | |
152 | int ll_front_merge_fn(struct request_queue *q, struct request *req, | |
153 | struct bio *bio); | |
154 | int attempt_back_merge(struct request_queue *q, struct request *rq); | |
155 | int attempt_front_merge(struct request_queue *q, struct request *rq); | |
156 | int blk_attempt_req_merge(struct request_queue *q, struct request *rq, | |
157 | struct request *next); | |
158 | void blk_recalc_rq_segments(struct request *rq); | |
159 | void blk_rq_set_mixed_merge(struct request *rq); | |
160 | bool blk_rq_merge_ok(struct request *rq, struct bio *bio); | |
161 | int blk_try_merge(struct request *rq, struct bio *bio); | |
162 | ||
163 | void blk_queue_congestion_threshold(struct request_queue *q); | |
164 | ||
165 | void __blk_run_queue_uncond(struct request_queue *q); | |
166 | ||
167 | int 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 | */ | |
175 | static 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 | */ | |
183 | static inline int queue_congestion_off_threshold(struct request_queue *q) | |
184 | { | |
185 | return q->nr_congestion_off; | |
186 | } | |
187 | ||
188 | extern int blk_update_nr_requests(struct request_queue *, unsigned int); | |
189 | ||
190 | /* | |
191 | * Contribute to IO statistics IFF: | |
192 | * | |
193 | * a) it's attached to a gendisk, and | |
194 | * b) the queue had IO stats enabled when this request was started, and | |
195 | * c) it's a file system request | |
196 | */ | |
197 | static inline int blk_do_io_stat(struct request *rq) | |
198 | { | |
199 | return rq->rq_disk && | |
200 | (rq->cmd_flags & REQ_IO_STAT) && | |
201 | (rq->cmd_type == REQ_TYPE_FS); | |
202 | } | |
203 | ||
204 | /* | |
205 | * Internal io_context interface | |
206 | */ | |
207 | void get_io_context(struct io_context *ioc); | |
208 | struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q); | |
209 | struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q, | |
210 | gfp_t gfp_mask); | |
211 | void ioc_clear_queue(struct request_queue *q); | |
212 | ||
213 | int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node); | |
214 | ||
215 | /** | |
216 | * create_io_context - try to create task->io_context | |
217 | * @gfp_mask: allocation mask | |
218 | * @node: allocation node | |
219 | * | |
220 | * If %current->io_context is %NULL, allocate a new io_context and install | |
221 | * it. Returns the current %current->io_context which may be %NULL if | |
222 | * allocation failed. | |
223 | * | |
224 | * Note that this function can't be called with IRQ disabled because | |
225 | * task_lock which protects %current->io_context is IRQ-unsafe. | |
226 | */ | |
227 | static inline struct io_context *create_io_context(gfp_t gfp_mask, int node) | |
228 | { | |
229 | WARN_ON_ONCE(irqs_disabled()); | |
230 | if (unlikely(!current->io_context)) | |
231 | create_task_io_context(current, gfp_mask, node); | |
232 | return current->io_context; | |
233 | } | |
234 | ||
235 | /* | |
236 | * Internal throttling interface | |
237 | */ | |
238 | #ifdef CONFIG_BLK_DEV_THROTTLING | |
239 | extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio); | |
240 | extern void blk_throtl_drain(struct request_queue *q); | |
241 | extern int blk_throtl_init(struct request_queue *q); | |
242 | extern void blk_throtl_exit(struct request_queue *q); | |
243 | #else /* CONFIG_BLK_DEV_THROTTLING */ | |
244 | static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio) | |
245 | { | |
246 | return false; | |
247 | } | |
248 | static inline void blk_throtl_drain(struct request_queue *q) { } | |
249 | static inline int blk_throtl_init(struct request_queue *q) { return 0; } | |
250 | static inline void blk_throtl_exit(struct request_queue *q) { } | |
251 | #endif /* CONFIG_BLK_DEV_THROTTLING */ | |
252 | ||
253 | #endif /* BLK_INTERNAL_H */ |