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1 | #ifndef BLK_INTERNAL_H |
2 | #define BLK_INTERNAL_H |
3 | |
4 | #include <linux/idr.h> |
5 | #include <linux/blk-mq.h> |
6 | #include "blk-mq.h" |
7 | |
8 | /* Amount of time in which a process may batch requests */ |
9 | #define BLK_BATCH_TIME (HZ/50UL) |
10 | |
11 | /* Number of requests a "batching" process may submit */ |
12 | #define BLK_BATCH_REQ 32 |
13 | |
14 | /* Max future timer expiry for timeouts */ |
15 | #define BLK_MAX_TIMEOUT (5 * HZ) |
16 | |
17 | struct blk_flush_queue { |
18 | unsigned int flush_queue_delayed:1; |
19 | unsigned int flush_pending_idx:1; |
20 | unsigned int flush_running_idx:1; |
21 | unsigned long flush_pending_since; |
22 | struct list_head flush_queue[2]; |
23 | struct list_head flush_data_in_flight; |
24 | struct request *flush_rq; |
25 | spinlock_t mq_flush_lock; |
26 | }; |
27 | |
28 | extern struct kmem_cache *blk_requestq_cachep; |
29 | extern struct kmem_cache *request_cachep; |
30 | extern struct kobj_type blk_queue_ktype; |
31 | extern struct ida blk_queue_ida; |
32 | |
33 | static inline struct blk_flush_queue *blk_get_flush_queue( |
34 | struct request_queue *q, struct blk_mq_ctx *ctx) |
35 | { |
36 | struct blk_mq_hw_ctx *hctx; |
37 | |
38 | if (!q->mq_ops) |
39 | return q->fq; |
40 | |
41 | hctx = q->mq_ops->map_queue(q, ctx->cpu); |
42 | |
43 | return hctx->fq; |
44 | } |
45 | |
46 | static inline void __blk_get_queue(struct request_queue *q) |
47 | { |
48 | kobject_get(&q->kobj); |
49 | } |
50 | |
51 | struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q, |
52 | int node, int cmd_size); |
53 | void blk_free_flush_queue(struct blk_flush_queue *q); |
54 | |
55 | int blk_init_rl(struct request_list *rl, struct request_queue *q, |
56 | gfp_t gfp_mask); |
57 | void blk_exit_rl(struct request_list *rl); |
58 | void init_request_from_bio(struct request *req, struct bio *bio); |
59 | void blk_rq_bio_prep(struct request_queue *q, struct request *rq, |
60 | struct bio *bio); |
61 | int blk_rq_append_bio(struct request_queue *q, struct request *rq, |
62 | struct bio *bio); |
63 | void blk_queue_bypass_start(struct request_queue *q); |
64 | void blk_queue_bypass_end(struct request_queue *q); |
65 | void blk_dequeue_request(struct request *rq); |
66 | void __blk_queue_free_tags(struct request_queue *q); |
67 | bool __blk_end_bidi_request(struct request *rq, int error, |
68 | unsigned int nr_bytes, unsigned int bidi_bytes); |
69 | |
70 | void blk_rq_timed_out_timer(unsigned long data); |
71 | unsigned long blk_rq_timeout(unsigned long timeout); |
72 | void blk_add_timer(struct request *req); |
73 | void blk_delete_timer(struct request *); |
74 | |
75 | |
76 | bool bio_attempt_front_merge(struct request_queue *q, struct request *req, |
77 | struct bio *bio); |
78 | bool bio_attempt_back_merge(struct request_queue *q, struct request *req, |
79 | struct bio *bio); |
80 | bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, |
81 | unsigned int *request_count); |
82 | |
83 | void blk_account_io_start(struct request *req, bool new_io); |
84 | void blk_account_io_completion(struct request *req, unsigned int bytes); |
85 | void blk_account_io_done(struct request *req); |
86 | |
87 | /* |
88 | * Internal atomic flags for request handling |
89 | */ |
90 | enum rq_atomic_flags { |
91 | REQ_ATOM_COMPLETE = 0, |
92 | REQ_ATOM_STARTED, |
93 | }; |
94 | |
95 | /* |
96 | * EH timer and IO completion will both attempt to 'grab' the request, make |
97 | * sure that only one of them succeeds |
98 | */ |
99 | static inline int blk_mark_rq_complete(struct request *rq) |
100 | { |
101 | return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); |
102 | } |
103 | |
104 | static inline void blk_clear_rq_complete(struct request *rq) |
105 | { |
106 | clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); |
107 | } |
108 | |
109 | /* |
110 | * Internal elevator interface |
111 | */ |
112 | #define ELV_ON_HASH(rq) ((rq)->cmd_flags & REQ_HASHED) |
113 | |
114 | void blk_insert_flush(struct request *rq); |
115 | |
116 | static inline struct request *__elv_next_request(struct request_queue *q) |
117 | { |
118 | struct request *rq; |
119 | struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL); |
120 | |
121 | while (1) { |
122 | if (!list_empty(&q->queue_head)) { |
123 | rq = list_entry_rq(q->queue_head.next); |
124 | return rq; |
125 | } |
126 | |
127 | /* |
128 | * Flush request is running and flush request isn't queueable |
129 | * in the drive, we can hold the queue till flush request is |
130 | * finished. Even we don't do this, driver can't dispatch next |
131 | * requests and will requeue them. And this can improve |
132 | * throughput too. For example, we have request flush1, write1, |
133 | * flush 2. flush1 is dispatched, then queue is hold, write1 |
134 | * isn't inserted to queue. After flush1 is finished, flush2 |
135 | * will be dispatched. Since disk cache is already clean, |
136 | * flush2 will be finished very soon, so looks like flush2 is |
137 | * folded to flush1. |
138 | * Since the queue is hold, a flag is set to indicate the queue |
139 | * should be restarted later. Please see flush_end_io() for |
140 | * details. |
141 | */ |
142 | if (fq->flush_pending_idx != fq->flush_running_idx && |
143 | !queue_flush_queueable(q)) { |
144 | fq->flush_queue_delayed = 1; |
145 | return NULL; |
146 | } |
147 | if (unlikely(blk_queue_bypass(q)) || |
148 | !q->elevator->type->ops.elevator_dispatch_fn(q, 0)) |
149 | return NULL; |
150 | } |
151 | } |
152 | |
153 | static inline void elv_activate_rq(struct request_queue *q, struct request *rq) |
154 | { |
155 | struct elevator_queue *e = q->elevator; |
156 | |
157 | if (e->type->ops.elevator_activate_req_fn) |
158 | e->type->ops.elevator_activate_req_fn(q, rq); |
159 | } |
160 | |
161 | static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq) |
162 | { |
163 | struct elevator_queue *e = q->elevator; |
164 | |
165 | if (e->type->ops.elevator_deactivate_req_fn) |
166 | e->type->ops.elevator_deactivate_req_fn(q, rq); |
167 | } |
168 | |
169 | #ifdef CONFIG_FAIL_IO_TIMEOUT |
170 | int blk_should_fake_timeout(struct request_queue *); |
171 | ssize_t part_timeout_show(struct device *, struct device_attribute *, char *); |
172 | ssize_t part_timeout_store(struct device *, struct device_attribute *, |
173 | const char *, size_t); |
174 | #else |
175 | static inline int blk_should_fake_timeout(struct request_queue *q) |
176 | { |
177 | return 0; |
178 | } |
179 | #endif |
180 | |
181 | int ll_back_merge_fn(struct request_queue *q, struct request *req, |
182 | struct bio *bio); |
183 | int ll_front_merge_fn(struct request_queue *q, struct request *req, |
184 | struct bio *bio); |
185 | int attempt_back_merge(struct request_queue *q, struct request *rq); |
186 | int attempt_front_merge(struct request_queue *q, struct request *rq); |
187 | int blk_attempt_req_merge(struct request_queue *q, struct request *rq, |
188 | struct request *next); |
189 | void blk_recalc_rq_segments(struct request *rq); |
190 | void blk_rq_set_mixed_merge(struct request *rq); |
191 | bool blk_rq_merge_ok(struct request *rq, struct bio *bio); |
192 | int blk_try_merge(struct request *rq, struct bio *bio); |
193 | |
194 | void blk_queue_congestion_threshold(struct request_queue *q); |
195 | |
196 | void __blk_run_queue_uncond(struct request_queue *q); |
197 | |
198 | int blk_dev_init(void); |
199 | |
200 | |
201 | /* |
202 | * Return the threshold (number of used requests) at which the queue is |
203 | * considered to be congested. It include a little hysteresis to keep the |
204 | * context switch rate down. |
205 | */ |
206 | static inline int queue_congestion_on_threshold(struct request_queue *q) |
207 | { |
208 | return q->nr_congestion_on; |
209 | } |
210 | |
211 | /* |
212 | * The threshold at which a queue is considered to be uncongested |
213 | */ |
214 | static inline int queue_congestion_off_threshold(struct request_queue *q) |
215 | { |
216 | return q->nr_congestion_off; |
217 | } |
218 | |
219 | extern int blk_update_nr_requests(struct request_queue *, unsigned int); |
220 | |
221 | /* |
222 | * Contribute to IO statistics IFF: |
223 | * |
224 | * a) it's attached to a gendisk, and |
225 | * b) the queue had IO stats enabled when this request was started, and |
226 | * c) it's a file system request |
227 | */ |
228 | static inline int blk_do_io_stat(struct request *rq) |
229 | { |
230 | return rq->rq_disk && |
231 | (rq->cmd_flags & REQ_IO_STAT) && |
232 | (rq->cmd_type == REQ_TYPE_FS); |
233 | } |
234 | |
235 | /* |
236 | * Internal io_context interface |
237 | */ |
238 | void get_io_context(struct io_context *ioc); |
239 | struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q); |
240 | struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q, |
241 | gfp_t gfp_mask); |
242 | void ioc_clear_queue(struct request_queue *q); |
243 | |
244 | int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node); |
245 | |
246 | /** |
247 | * create_io_context - try to create task->io_context |
248 | * @gfp_mask: allocation mask |
249 | * @node: allocation node |
250 | * |
251 | * If %current->io_context is %NULL, allocate a new io_context and install |
252 | * it. Returns the current %current->io_context which may be %NULL if |
253 | * allocation failed. |
254 | * |
255 | * Note that this function can't be called with IRQ disabled because |
256 | * task_lock which protects %current->io_context is IRQ-unsafe. |
257 | */ |
258 | static inline struct io_context *create_io_context(gfp_t gfp_mask, int node) |
259 | { |
260 | WARN_ON_ONCE(irqs_disabled()); |
261 | if (unlikely(!current->io_context)) |
262 | create_task_io_context(current, gfp_mask, node); |
263 | return current->io_context; |
264 | } |
265 | |
266 | /* |
267 | * Internal throttling interface |
268 | */ |
269 | #ifdef CONFIG_BLK_DEV_THROTTLING |
270 | extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio); |
271 | extern void blk_throtl_drain(struct request_queue *q); |
272 | extern int blk_throtl_init(struct request_queue *q); |
273 | extern void blk_throtl_exit(struct request_queue *q); |
274 | #else /* CONFIG_BLK_DEV_THROTTLING */ |
275 | static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio) |
276 | { |
277 | return false; |
278 | } |
279 | static inline void blk_throtl_drain(struct request_queue *q) { } |
280 | static inline int blk_throtl_init(struct request_queue *q) { return 0; } |
281 | static inline void blk_throtl_exit(struct request_queue *q) { } |
282 | #endif /* CONFIG_BLK_DEV_THROTTLING */ |
283 | |
284 | #endif /* BLK_INTERNAL_H */ |
285 |
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