blob: 24fcaeeaf6202b1e19de9f8e57477b97bccc4065 [file] [log] [blame]
Jens Axboe8324aa92008-01-29 14:51:59 +01001#ifndef BLK_INTERNAL_H
2#define BLK_INTERNAL_H
3
Jens Axboe86db1e22008-01-29 14:53:40 +01004/* 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
Jens Axboe8324aa92008-01-29 14:51:59 +010010extern struct kmem_cache *blk_requestq_cachep;
11extern struct kobj_type blk_queue_ktype;
12
Jens Axboe86db1e22008-01-29 14:53:40 +010013void 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);
Jens Axboe8324aa92008-01-29 14:51:59 +010016void __blk_queue_free_tags(struct request_queue *q);
17
Jens Axboe86db1e22008-01-29 14:53:40 +010018void blk_unplug_work(struct work_struct *work);
19void blk_unplug_timeout(unsigned long data);
Jens Axboe242f9dc2008-09-14 05:55:09 -070020void blk_rq_timed_out_timer(unsigned long data);
21void blk_delete_timer(struct request *);
22void blk_add_timer(struct request *);
Jens Axboef73e2d12008-10-17 14:03:08 +020023void __generic_unplug_device(struct request_queue *);
Jens Axboe242f9dc2008-09-14 05:55:09 -070024
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}
Jens Axboe86db1e22008-01-29 14:53:40 +010045
Jens Axboe581d4e22008-09-14 05:56:33 -070046#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
Jens Axboe86db1e22008-01-29 14:53:40 +010058struct io_context *current_io_context(gfp_t gfp_flags, int node);
59
Jens Axboed6d48192008-01-29 14:04:06 +010060int 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
Jens Axboe8324aa92008-01-29 14:51:59 +010069void blk_queue_congestion_threshold(struct request_queue *q);
70
Adrian Bunkff889722008-03-04 11:23:45 +010071int blk_dev_init(void);
72
Jens Axboe6c7e8ce2009-03-27 10:30:47 +010073void elv_quisce_start(struct request_queue *q);
74void elv_quisce_end(struct request_queue *q);
75
76
Jens Axboe8324aa92008-01-29 14:51:59 +010077/*
78 * Return the threshold (number of used requests) at which the queue is
79 * considered to be congested. It include a little hysteresis to keep the
80 * context switch rate down.
81 */
82static inline int queue_congestion_on_threshold(struct request_queue *q)
83{
84 return q->nr_congestion_on;
85}
86
87/*
88 * The threshold at which a queue is considered to be uncongested
89 */
90static inline int queue_congestion_off_threshold(struct request_queue *q)
91{
92 return q->nr_congestion_off;
93}
94
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +020095#if defined(CONFIG_BLK_DEV_INTEGRITY)
96
97#define rq_for_each_integrity_segment(bvl, _rq, _iter) \
98 __rq_for_each_bio(_iter.bio, _rq) \
99 bip_for_each_vec(bvl, _iter.bio->bi_integrity, _iter.i)
100
101#endif /* BLK_DEV_INTEGRITY */
102
Jens Axboec7c22e42008-09-13 20:26:01 +0200103static inline int blk_cpu_to_group(int cpu)
104{
105#ifdef CONFIG_SCHED_MC
Rusty Russellbe4d6382008-12-26 22:23:43 +1030106 const struct cpumask *mask = cpu_coregroup_mask(cpu);
107 return cpumask_first(mask);
Jens Axboec7c22e42008-09-13 20:26:01 +0200108#elif defined(CONFIG_SCHED_SMT)
Rusty Russellc69fc562009-03-13 14:49:46 +1030109 return cpumask_first(topology_thread_cpumask(cpu));
Jens Axboec7c22e42008-09-13 20:26:01 +0200110#else
111 return cpu;
112#endif
113}
114
Jerome Marchand26308ea2009-03-27 10:31:51 +0100115static inline int blk_do_io_stat(struct request *rq)
Jens Axboefb8ec182009-02-02 08:42:32 +0100116{
Jerome Marchand26308ea2009-03-27 10:31:51 +0100117 struct gendisk *disk = rq->rq_disk;
Jens Axboefb8ec182009-02-02 08:42:32 +0100118
Jerome Marchand26308ea2009-03-27 10:31:51 +0100119 if (!disk || !disk->queue)
120 return 0;
121
122 return blk_queue_io_stat(disk->queue) && (rq->cmd_flags & REQ_ELVPRIV);
Jens Axboefb8ec182009-02-02 08:42:32 +0100123}
124
Jens Axboe8324aa92008-01-29 14:51:59 +0100125#endif