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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 | 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); |
24 | int blk_rq_append_bio(struct request_queue *q, struct request *rq, |
25 | struct bio *bio); |
26 | void blk_queue_bypass_start(struct request_queue *q); |
27 | void blk_queue_bypass_end(struct request_queue *q); |
28 | void blk_dequeue_request(struct request *rq); |
29 | void __blk_queue_free_tags(struct request_queue *q); |
30 | bool __blk_end_bidi_request(struct request *rq, int error, |
31 | unsigned int nr_bytes, unsigned int bidi_bytes); |
32 | |
33 | void blk_rq_timed_out_timer(unsigned long data); |
34 | void blk_delete_timer(struct request *); |
35 | void blk_add_timer(struct request *); |
36 | void __generic_unplug_device(struct request_queue *); |
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 |
47 | * sure that only one of them succeeds |
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 | } |
58 | |
59 | /* |
60 | * Internal elevator interface |
61 | */ |
62 | #define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash)) |
63 | |
64 | void blk_insert_flush(struct request *rq); |
65 | void blk_abort_flushes(struct request_queue *q); |
66 | |
67 | static inline struct request *__elv_next_request(struct request_queue *q) |
68 | { |
69 | struct request *rq; |
70 | |
71 | while (1) { |
72 | if (!list_empty(&q->queue_head)) { |
73 | rq = list_entry_rq(q->queue_head.next); |
74 | return rq; |
75 | } |
76 | |
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 | } |
97 | if (unlikely(blk_queue_dead(q)) || |
98 | !q->elevator->type->ops.elevator_dispatch_fn(q, 0)) |
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 | |
107 | if (e->type->ops.elevator_activate_req_fn) |
108 | e->type->ops.elevator_activate_req_fn(q, rq); |
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 | |
115 | if (e->type->ops.elevator_deactivate_req_fn) |
116 | e->type->ops.elevator_deactivate_req_fn(q, rq); |
117 | } |
118 | |
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 | |
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); |
137 | int blk_attempt_req_merge(struct request_queue *q, struct request *rq, |
138 | struct request *next); |
139 | void blk_recalc_rq_segments(struct request *rq); |
140 | void blk_rq_set_mixed_merge(struct request *rq); |
141 | bool blk_rq_merge_ok(struct request *rq, struct bio *bio); |
142 | int blk_try_merge(struct request *rq, struct bio *bio); |
143 | |
144 | void blk_queue_congestion_threshold(struct request_queue *q); |
145 | |
146 | int blk_dev_init(void); |
147 | |
148 | |
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 | |
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 |
172 | * c) it's a file system request or a discard request |
173 | */ |
174 | static inline int blk_do_io_stat(struct request *rq) |
175 | { |
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)); |
180 | } |
181 | |
182 | /* |
183 | * Internal io_context interface |
184 | */ |
185 | void get_io_context(struct io_context *ioc); |
186 | struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q); |
187 | struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q, |
188 | gfp_t gfp_mask); |
189 | void ioc_clear_queue(struct request_queue *q); |
190 | |
191 | int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node); |
192 | |
193 | /** |
194 | * create_io_context - try to create task->io_context |
195 | * @gfp_mask: allocation mask |
196 | * @node: allocation node |
197 | * |
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. |
201 | * |
202 | * Note that this function can't be called with IRQ disabled because |
203 | * task_lock which protects %current->io_context is IRQ-unsafe. |
204 | */ |
205 | static inline struct io_context *create_io_context(gfp_t gfp_mask, int node) |
206 | { |
207 | WARN_ON_ONCE(irqs_disabled()); |
208 | if (unlikely(!current->io_context)) |
209 | create_task_io_context(current, gfp_mask, node); |
210 | return current->io_context; |
211 | } |
212 | |
213 | /* |
214 | * Internal throttling interface |
215 | */ |
216 | #ifdef CONFIG_BLK_DEV_THROTTLING |
217 | extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio); |
218 | extern void blk_throtl_drain(struct request_queue *q); |
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 */ |
222 | static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio) |
223 | { |
224 | return false; |
225 | } |
226 | static inline void blk_throtl_drain(struct request_queue *q) { } |
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 */ |
232 |
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