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