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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 | extern struct kmem_cache *blk_requestq_cachep; |
13 | extern struct kmem_cache *request_cachep; |
14 | extern struct kobj_type blk_queue_ktype; |
15 | extern struct ida blk_queue_ida; |
16 | |
17 | static inline void __blk_get_queue(struct request_queue *q) |
18 | { |
19 | kobject_get(&q->kobj); |
20 | } |
21 | |
22 | int blk_init_rl(struct request_list *rl, struct request_queue *q, |
23 | gfp_t gfp_mask); |
24 | void blk_exit_rl(struct request_list *rl); |
25 | void init_request_from_bio(struct request *req, struct bio *bio); |
26 | void blk_rq_bio_prep(struct request_queue *q, struct request *rq, |
27 | struct bio *bio); |
28 | int blk_rq_append_bio(struct request_queue *q, struct request *rq, |
29 | struct bio *bio); |
30 | void blk_queue_bypass_start(struct request_queue *q); |
31 | void blk_queue_bypass_end(struct request_queue *q); |
32 | void blk_dequeue_request(struct request *rq); |
33 | void __blk_queue_free_tags(struct request_queue *q); |
34 | bool __blk_end_bidi_request(struct request *rq, int error, |
35 | unsigned int nr_bytes, unsigned int bidi_bytes); |
36 | |
37 | void blk_rq_timed_out_timer(unsigned long data); |
38 | void blk_rq_check_expired(struct request *rq, unsigned long *next_timeout, |
39 | unsigned int *next_set); |
40 | void __blk_add_timer(struct request *req, struct list_head *timeout_list); |
41 | void blk_delete_timer(struct request *); |
42 | void blk_add_timer(struct request *); |
43 | |
44 | |
45 | bool bio_attempt_front_merge(struct request_queue *q, struct request *req, |
46 | struct bio *bio); |
47 | bool bio_attempt_back_merge(struct request_queue *q, struct request *req, |
48 | struct bio *bio); |
49 | bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio, |
50 | unsigned int *request_count); |
51 | |
52 | void blk_account_io_start(struct request *req, bool new_io); |
53 | void blk_account_io_completion(struct request *req, unsigned int bytes); |
54 | void blk_account_io_done(struct request *req); |
55 | |
56 | /* |
57 | * Internal atomic flags for request handling |
58 | */ |
59 | enum 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 | */ |
68 | static inline int blk_mark_rq_complete(struct request *rq) |
69 | { |
70 | return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); |
71 | } |
72 | |
73 | static 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) hash_hashed(&(rq)->hash) |
82 | |
83 | void blk_insert_flush(struct request *rq); |
84 | void blk_abort_flushes(struct request_queue *q); |
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_dying(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 | /* |
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 | */ |
195 | static 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 | */ |
205 | void get_io_context(struct io_context *ioc); |
206 | struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q); |
207 | struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q, |
208 | gfp_t gfp_mask); |
209 | void ioc_clear_queue(struct request_queue *q); |
210 | |
211 | int 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 | */ |
225 | static 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 |
237 | extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio); |
238 | extern void blk_throtl_drain(struct request_queue *q); |
239 | extern int blk_throtl_init(struct request_queue *q); |
240 | extern void blk_throtl_exit(struct request_queue *q); |
241 | #else /* CONFIG_BLK_DEV_THROTTLING */ |
242 | static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio) |
243 | { |
244 | return false; |
245 | } |
246 | static inline void blk_throtl_drain(struct request_queue *q) { } |
247 | static inline int blk_throtl_init(struct request_queue *q) { return 0; } |
248 | static inline void blk_throtl_exit(struct request_queue *q) { } |
249 | #endif /* CONFIG_BLK_DEV_THROTTLING */ |
250 | |
251 | #endif /* BLK_INTERNAL_H */ |
252 |
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