Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / block / blk.h
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1#ifndef BLK_INTERNAL_H
2#define BLK_INTERNAL_H
3
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4/* Amount of time in which a process may batch requests */
5#define BLK_BATCH_TIME (HZ/50UL)
6
7/* Number of requests a "batching" process may submit */
8#define BLK_BATCH_REQ 32
9
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10extern struct kmem_cache *blk_requestq_cachep;
11extern struct kobj_type blk_queue_ktype;
12
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13void init_request_from_bio(struct request *req, struct bio *bio);
14void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
15 struct bio *bio);
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16void __blk_queue_free_tags(struct request_queue *q);
17
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18void blk_unplug_work(struct work_struct *work);
19void blk_unplug_timeout(unsigned long data);
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20void blk_rq_timed_out_timer(unsigned long data);
21void blk_delete_timer(struct request *);
22void blk_add_timer(struct request *);
f73e2d13 23void __generic_unplug_device(struct request_queue *);
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24
25/*
26 * Internal atomic flags for request handling
27 */
28enum rq_atomic_flags {
29 REQ_ATOM_COMPLETE = 0,
30};
31
32/*
33 * EH timer and IO completion will both attempt to 'grab' the request, make
34 * sure that only one of them suceeds
35 */
36static inline int blk_mark_rq_complete(struct request *rq)
37{
38 return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
39}
40
41static inline void blk_clear_rq_complete(struct request *rq)
42{
43 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
44}
86db1e29 45
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46#ifdef CONFIG_FAIL_IO_TIMEOUT
47int blk_should_fake_timeout(struct request_queue *);
48ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
49ssize_t part_timeout_store(struct device *, struct device_attribute *,
50 const char *, size_t);
51#else
52static inline int blk_should_fake_timeout(struct request_queue *q)
53{
54 return 0;
55}
56#endif
57
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58struct io_context *current_io_context(gfp_t gfp_flags, int node);
59
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60int ll_back_merge_fn(struct request_queue *q, struct request *req,
61 struct bio *bio);
62int ll_front_merge_fn(struct request_queue *q, struct request *req,
63 struct bio *bio);
64int attempt_back_merge(struct request_queue *q, struct request *rq);
65int attempt_front_merge(struct request_queue *q, struct request *rq);
66void blk_recalc_rq_segments(struct request *rq);
67void blk_recalc_rq_sectors(struct request *rq, int nsect);
68
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69void blk_queue_congestion_threshold(struct request_queue *q);
70
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71int blk_dev_init(void);
72
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73/*
74 * Return the threshold (number of used requests) at which the queue is
75 * considered to be congested. It include a little hysteresis to keep the
76 * context switch rate down.
77 */
78static inline int queue_congestion_on_threshold(struct request_queue *q)
79{
80 return q->nr_congestion_on;
81}
82
83/*
84 * The threshold at which a queue is considered to be uncongested
85 */
86static inline int queue_congestion_off_threshold(struct request_queue *q)
87{
88 return q->nr_congestion_off;
89}
90
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91#if defined(CONFIG_BLK_DEV_INTEGRITY)
92
93#define rq_for_each_integrity_segment(bvl, _rq, _iter) \
94 __rq_for_each_bio(_iter.bio, _rq) \
95 bip_for_each_vec(bvl, _iter.bio->bi_integrity, _iter.i)
96
97#endif /* BLK_DEV_INTEGRITY */
98
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99static inline int blk_cpu_to_group(int cpu)
100{
101#ifdef CONFIG_SCHED_MC
102 cpumask_t mask = cpu_coregroup_map(cpu);
103 return first_cpu(mask);
104#elif defined(CONFIG_SCHED_SMT)
105 return first_cpu(per_cpu(cpu_sibling_map, cpu));
106#else
107 return cpu;
108#endif
109}
110
8324aa91 111#endif