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Jens Axboe8324aa92008-01-29 14:51:59 +01001#ifndef BLK_INTERNAL_H
2#define BLK_INTERNAL_H
3
Tejun Heoa73f7302011-12-14 00:33:37 +01004#include <linux/idr.h>
5
Jens Axboe86db1e22008-01-29 14:53:40 +01006/* 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
Jens Axboe8324aa92008-01-29 14:51:59 +010012extern struct kmem_cache *blk_requestq_cachep;
13extern struct kobj_type blk_queue_ktype;
Tejun Heoa73f7302011-12-14 00:33:37 +010014extern struct ida blk_queue_ida;
Jens Axboe8324aa92008-01-29 14:51:59 +010015
Tejun Heo09ac46c2011-12-14 00:33:38 +010016static inline void __blk_get_queue(struct request_queue *q)
17{
18 kobject_get(&q->kobj);
19}
20
Tejun Heo5b788ce2012-06-04 20:40:59 -070021int blk_init_rl(struct request_list *rl, struct request_queue *q,
22 gfp_t gfp_mask);
23void blk_exit_rl(struct request_list *rl);
Jens Axboe86db1e22008-01-29 14:53:40 +010024void init_request_from_bio(struct request *req, struct bio *bio);
25void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
26 struct bio *bio);
Boaz Harrosha411f4b2009-05-17 19:00:01 +030027int blk_rq_append_bio(struct request_queue *q, struct request *rq,
28 struct bio *bio);
Tejun Heod7325802012-03-05 13:14:58 -080029void blk_queue_bypass_start(struct request_queue *q);
30void blk_queue_bypass_end(struct request_queue *q);
Tejun Heo9934c8c2009-05-08 11:54:16 +090031void blk_dequeue_request(struct request *rq);
Jens Axboe8324aa92008-01-29 14:51:59 +010032void __blk_queue_free_tags(struct request_queue *q);
Jeff Moyer4853aba2011-08-15 21:37:25 +020033bool __blk_end_bidi_request(struct request *rq, int error,
34 unsigned int nr_bytes, unsigned int bidi_bytes);
Jens Axboe8324aa92008-01-29 14:51:59 +010035
Jens Axboe242f9dc2008-09-14 05:55:09 -070036void blk_rq_timed_out_timer(unsigned long data);
37void blk_delete_timer(struct request *);
38void blk_add_timer(struct request *);
39
40/*
41 * Internal atomic flags for request handling
42 */
43enum 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
Lucas De Marchi25985ed2011-03-30 22:57:33 -030049 * sure that only one of them succeeds
Jens Axboe242f9dc2008-09-14 05:55:09 -070050 */
51static inline int blk_mark_rq_complete(struct request *rq)
52{
53 return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
54}
55
56static inline void blk_clear_rq_complete(struct request *rq)
57{
58 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
59}
Jens Axboe86db1e22008-01-29 14:53:40 +010060
Tejun Heo158dbda2009-04-23 11:05:18 +090061/*
62 * Internal elevator interface
63 */
64#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash))
65
Tejun Heoae1b1532011-01-25 12:43:54 +010066void blk_insert_flush(struct request *rq);
67void blk_abort_flushes(struct request_queue *q);
Tejun Heodd831002010-09-03 11:56:16 +020068
Tejun Heo158dbda2009-04-23 11:05:18 +090069static inline struct request *__elv_next_request(struct request_queue *q)
70{
71 struct request *rq;
72
73 while (1) {
Tejun Heoae1b1532011-01-25 12:43:54 +010074 if (!list_empty(&q->queue_head)) {
Tejun Heo158dbda2009-04-23 11:05:18 +090075 rq = list_entry_rq(q->queue_head.next);
Tejun Heoae1b1532011-01-25 12:43:54 +010076 return rq;
Tejun Heo158dbda2009-04-23 11:05:18 +090077 }
78
shaohua.li@intel.com3ac0cc42011-05-06 11:34:41 -060079 /*
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 }
Bart Van Assche3f3299d2012-11-28 13:42:38 +010099 if (unlikely(blk_queue_dying(q)) ||
Tejun Heo22f746e2011-12-14 00:33:41 +0100100 !q->elevator->type->ops.elevator_dispatch_fn(q, 0))
Tejun Heo158dbda2009-04-23 11:05:18 +0900101 return NULL;
102 }
103}
104
105static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
106{
107 struct elevator_queue *e = q->elevator;
108
Tejun Heo22f746e2011-12-14 00:33:41 +0100109 if (e->type->ops.elevator_activate_req_fn)
110 e->type->ops.elevator_activate_req_fn(q, rq);
Tejun Heo158dbda2009-04-23 11:05:18 +0900111}
112
113static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
114{
115 struct elevator_queue *e = q->elevator;
116
Tejun Heo22f746e2011-12-14 00:33:41 +0100117 if (e->type->ops.elevator_deactivate_req_fn)
118 e->type->ops.elevator_deactivate_req_fn(q, rq);
Tejun Heo158dbda2009-04-23 11:05:18 +0900119}
120
Jens Axboe581d4e22008-09-14 05:56:33 -0700121#ifdef CONFIG_FAIL_IO_TIMEOUT
122int blk_should_fake_timeout(struct request_queue *);
123ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
124ssize_t part_timeout_store(struct device *, struct device_attribute *,
125 const char *, size_t);
126#else
127static inline int blk_should_fake_timeout(struct request_queue *q)
128{
129 return 0;
130}
131#endif
132
Jens Axboed6d48192008-01-29 14:04:06 +0100133int ll_back_merge_fn(struct request_queue *q, struct request *req,
134 struct bio *bio);
135int ll_front_merge_fn(struct request_queue *q, struct request *req,
136 struct bio *bio);
137int attempt_back_merge(struct request_queue *q, struct request *rq);
138int attempt_front_merge(struct request_queue *q, struct request *rq);
Jens Axboe5e84ea32011-03-21 10:14:27 +0100139int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
140 struct request *next);
Jens Axboed6d48192008-01-29 14:04:06 +0100141void blk_recalc_rq_segments(struct request *rq);
Tejun Heo80a761f2009-07-03 17:48:17 +0900142void blk_rq_set_mixed_merge(struct request *rq);
Tejun Heo050c8ea2012-02-08 09:19:38 +0100143bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
144int blk_try_merge(struct request *rq, struct bio *bio);
Jens Axboed6d48192008-01-29 14:04:06 +0100145
Jens Axboe8324aa92008-01-29 14:51:59 +0100146void blk_queue_congestion_threshold(struct request_queue *q);
147
Bart Van Asschec246e802012-12-06 14:32:01 +0100148void __blk_run_queue_uncond(struct request_queue *q);
149
Adrian Bunkff889722008-03-04 11:23:45 +0100150int blk_dev_init(void);
151
Jens Axboef253b862010-10-24 22:06:02 +0200152
Jens Axboe8324aa92008-01-29 14:51:59 +0100153/*
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 */
158static 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 */
166static inline int queue_congestion_off_threshold(struct request_queue *q)
167{
168 return q->nr_congestion_off;
169}
170
Jens Axboec2553b52009-04-24 08:10:11 +0200171/*
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
Martin K. Petersene2a60da2012-09-18 12:19:25 -0400176 * c) it's a file system request
Jens Axboec2553b52009-04-24 08:10:11 +0200177 */
Jerome Marchand26308ea2009-03-27 10:31:51 +0100178static inline int blk_do_io_stat(struct request *rq)
Jens Axboefb8ec182009-02-02 08:42:32 +0100179{
Christoph Hellwig33659eb2010-08-07 18:17:56 +0200180 return rq->rq_disk &&
181 (rq->cmd_flags & REQ_IO_STAT) &&
Martin K. Petersene2a60da2012-09-18 12:19:25 -0400182 (rq->cmd_type == REQ_TYPE_FS);
Jens Axboefb8ec182009-02-02 08:42:32 +0100183}
184
Tejun Heof2dbd762011-12-14 00:33:40 +0100185/*
186 * Internal io_context interface
187 */
188void get_io_context(struct io_context *ioc);
Tejun Heo47fdd4c2011-12-14 00:33:42 +0100189struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
Tejun Heo24acfc32012-03-05 13:15:24 -0800190struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
191 gfp_t gfp_mask);
Tejun Heo7e5a8792011-12-14 00:33:42 +0100192void ioc_clear_queue(struct request_queue *q);
Tejun Heof2dbd762011-12-14 00:33:40 +0100193
Tejun Heo24acfc32012-03-05 13:15:24 -0800194int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
Tejun Heof2dbd762011-12-14 00:33:40 +0100195
196/**
197 * create_io_context - try to create task->io_context
Tejun Heof2dbd762011-12-14 00:33:40 +0100198 * @gfp_mask: allocation mask
199 * @node: allocation node
200 *
Tejun Heo24acfc32012-03-05 13:15:24 -0800201 * 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.
Tejun Heof2dbd762011-12-14 00:33:40 +0100204 *
205 * Note that this function can't be called with IRQ disabled because
Tejun Heo24acfc32012-03-05 13:15:24 -0800206 * task_lock which protects %current->io_context is IRQ-unsafe.
Tejun Heof2dbd762011-12-14 00:33:40 +0100207 */
Tejun Heo24acfc32012-03-05 13:15:24 -0800208static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
Tejun Heof2dbd762011-12-14 00:33:40 +0100209{
210 WARN_ON_ONCE(irqs_disabled());
Tejun Heo24acfc32012-03-05 13:15:24 -0800211 if (unlikely(!current->io_context))
212 create_task_io_context(current, gfp_mask, node);
213 return current->io_context;
Tejun Heof2dbd762011-12-14 00:33:40 +0100214}
215
216/*
217 * Internal throttling interface
218 */
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200219#ifdef CONFIG_BLK_DEV_THROTTLING
Tejun Heobc16a4f2011-10-19 14:33:01 +0200220extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio);
Tejun Heoc9a929d2011-10-19 14:42:16 +0200221extern void blk_throtl_drain(struct request_queue *q);
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200222extern int blk_throtl_init(struct request_queue *q);
223extern void blk_throtl_exit(struct request_queue *q);
224#else /* CONFIG_BLK_DEV_THROTTLING */
Tejun Heobc16a4f2011-10-19 14:33:01 +0200225static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio)
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200226{
Tejun Heobc16a4f2011-10-19 14:33:01 +0200227 return false;
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200228}
Tejun Heoc9a929d2011-10-19 14:42:16 +0200229static inline void blk_throtl_drain(struct request_queue *q) { }
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200230static inline int blk_throtl_init(struct request_queue *q) { return 0; }
231static inline void blk_throtl_exit(struct request_queue *q) { }
232#endif /* CONFIG_BLK_DEV_THROTTLING */
233
234#endif /* BLK_INTERNAL_H */