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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;
Jens Axboe320ae512013-10-24 09:20:05 +010013extern struct kmem_cache *request_cachep;
Jens Axboe8324aa92008-01-29 14:51:59 +010014extern struct kobj_type blk_queue_ktype;
Tejun Heoa73f7302011-12-14 00:33:37 +010015extern struct ida blk_queue_ida;
Jens Axboe8324aa92008-01-29 14:51:59 +010016
Tejun Heo09ac46c2011-12-14 00:33:38 +010017static inline void __blk_get_queue(struct request_queue *q)
18{
19 kobject_get(&q->kobj);
20}
21
Tejun Heo5b788ce2012-06-04 20:40:59 -070022int blk_init_rl(struct request_list *rl, struct request_queue *q,
23 gfp_t gfp_mask);
24void blk_exit_rl(struct request_list *rl);
Jens Axboe86db1e22008-01-29 14:53:40 +010025void init_request_from_bio(struct request *req, struct bio *bio);
26void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
27 struct bio *bio);
Boaz Harrosha411f4b2009-05-17 19:00:01 +030028int blk_rq_append_bio(struct request_queue *q, struct request *rq,
29 struct bio *bio);
Tejun Heod7325802012-03-05 13:14:58 -080030void blk_queue_bypass_start(struct request_queue *q);
31void blk_queue_bypass_end(struct request_queue *q);
Tejun Heo9934c8c2009-05-08 11:54:16 +090032void blk_dequeue_request(struct request *rq);
Jens Axboe8324aa92008-01-29 14:51:59 +010033void __blk_queue_free_tags(struct request_queue *q);
Jeff Moyer4853aba2011-08-15 21:37:25 +020034bool __blk_end_bidi_request(struct request *rq, int error,
35 unsigned int nr_bytes, unsigned int bidi_bytes);
Jens Axboe8324aa92008-01-29 14:51:59 +010036
Jens Axboe242f9dc2008-09-14 05:55:09 -070037void blk_rq_timed_out_timer(unsigned long data);
Jens Axboe320ae512013-10-24 09:20:05 +010038void blk_rq_check_expired(struct request *rq, unsigned long *next_timeout,
39 unsigned int *next_set);
40void __blk_add_timer(struct request *req, struct list_head *timeout_list);
Jens Axboe242f9dc2008-09-14 05:55:09 -070041void blk_delete_timer(struct request *);
42void blk_add_timer(struct request *);
43
Jens Axboe320ae512013-10-24 09:20:05 +010044
45bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
46 struct bio *bio);
47bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
48 struct bio *bio);
49bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
50 unsigned int *request_count);
51
52void blk_account_io_start(struct request *req, bool new_io);
53void blk_account_io_completion(struct request *req, unsigned int bytes);
54void blk_account_io_done(struct request *req);
55
Jens Axboe242f9dc2008-09-14 05:55:09 -070056/*
57 * Internal atomic flags for request handling
58 */
59enum rq_atomic_flags {
60 REQ_ATOM_COMPLETE = 0,
Jens Axboe320ae512013-10-24 09:20:05 +010061 REQ_ATOM_STARTED,
Jens Axboe242f9dc2008-09-14 05:55:09 -070062};
63
64/*
65 * EH timer and IO completion will both attempt to 'grab' the request, make
Lucas De Marchi25985ed2011-03-30 22:57:33 -030066 * sure that only one of them succeeds
Jens Axboe242f9dc2008-09-14 05:55:09 -070067 */
68static inline int blk_mark_rq_complete(struct request *rq)
69{
70 return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
71}
72
73static inline void blk_clear_rq_complete(struct request *rq)
74{
75 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
76}
Jens Axboe86db1e22008-01-29 14:53:40 +010077
Tejun Heo158dbda2009-04-23 11:05:18 +090078/*
79 * Internal elevator interface
80 */
Jens Axboe360f92c2014-04-09 20:27:01 -060081#define ELV_ON_HASH(rq) ((rq)->cmd_flags & REQ_HASHED)
Tejun Heo158dbda2009-04-23 11:05:18 +090082
Tejun Heoae1b1532011-01-25 12:43:54 +010083void blk_insert_flush(struct request *rq);
84void blk_abort_flushes(struct request_queue *q);
Tejun Heodd831002010-09-03 11:56:16 +020085
Tejun Heo158dbda2009-04-23 11:05:18 +090086static inline struct request *__elv_next_request(struct request_queue *q)
87{
88 struct request *rq;
89
90 while (1) {
Tejun Heoae1b1532011-01-25 12:43:54 +010091 if (!list_empty(&q->queue_head)) {
Tejun Heo158dbda2009-04-23 11:05:18 +090092 rq = list_entry_rq(q->queue_head.next);
Tejun Heoae1b1532011-01-25 12:43:54 +010093 return rq;
Tejun Heo158dbda2009-04-23 11:05:18 +090094 }
95
shaohua.li@intel.com3ac0cc42011-05-06 11:34:41 -060096 /*
97 * Flush request is running and flush request isn't queueable
98 * in the drive, we can hold the queue till flush request is
99 * finished. Even we don't do this, driver can't dispatch next
100 * requests and will requeue them. And this can improve
101 * throughput too. For example, we have request flush1, write1,
102 * flush 2. flush1 is dispatched, then queue is hold, write1
103 * isn't inserted to queue. After flush1 is finished, flush2
104 * will be dispatched. Since disk cache is already clean,
105 * flush2 will be finished very soon, so looks like flush2 is
106 * folded to flush1.
107 * Since the queue is hold, a flag is set to indicate the queue
108 * should be restarted later. Please see flush_end_io() for
109 * details.
110 */
111 if (q->flush_pending_idx != q->flush_running_idx &&
112 !queue_flush_queueable(q)) {
113 q->flush_queue_delayed = 1;
114 return NULL;
115 }
Tejun Heo556ee812014-01-29 14:56:16 -0700116 if (unlikely(blk_queue_bypass(q)) ||
Tejun Heo22f746e2011-12-14 00:33:41 +0100117 !q->elevator->type->ops.elevator_dispatch_fn(q, 0))
Tejun Heo158dbda2009-04-23 11:05:18 +0900118 return NULL;
119 }
120}
121
122static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
123{
124 struct elevator_queue *e = q->elevator;
125
Tejun Heo22f746e2011-12-14 00:33:41 +0100126 if (e->type->ops.elevator_activate_req_fn)
127 e->type->ops.elevator_activate_req_fn(q, rq);
Tejun Heo158dbda2009-04-23 11:05:18 +0900128}
129
130static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
131{
132 struct elevator_queue *e = q->elevator;
133
Tejun Heo22f746e2011-12-14 00:33:41 +0100134 if (e->type->ops.elevator_deactivate_req_fn)
135 e->type->ops.elevator_deactivate_req_fn(q, rq);
Tejun Heo158dbda2009-04-23 11:05:18 +0900136}
137
Jens Axboe581d4e22008-09-14 05:56:33 -0700138#ifdef CONFIG_FAIL_IO_TIMEOUT
139int blk_should_fake_timeout(struct request_queue *);
140ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
141ssize_t part_timeout_store(struct device *, struct device_attribute *,
142 const char *, size_t);
143#else
144static inline int blk_should_fake_timeout(struct request_queue *q)
145{
146 return 0;
147}
148#endif
149
Jens Axboed6d48192008-01-29 14:04:06 +0100150int ll_back_merge_fn(struct request_queue *q, struct request *req,
151 struct bio *bio);
152int ll_front_merge_fn(struct request_queue *q, struct request *req,
153 struct bio *bio);
154int attempt_back_merge(struct request_queue *q, struct request *rq);
155int attempt_front_merge(struct request_queue *q, struct request *rq);
Jens Axboe5e84ea32011-03-21 10:14:27 +0100156int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
157 struct request *next);
Jens Axboed6d48192008-01-29 14:04:06 +0100158void blk_recalc_rq_segments(struct request *rq);
Tejun Heo80a761f2009-07-03 17:48:17 +0900159void blk_rq_set_mixed_merge(struct request *rq);
Tejun Heo050c8ea2012-02-08 09:19:38 +0100160bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
161int blk_try_merge(struct request *rq, struct bio *bio);
Jens Axboed6d48192008-01-29 14:04:06 +0100162
Jens Axboe8324aa92008-01-29 14:51:59 +0100163void blk_queue_congestion_threshold(struct request_queue *q);
164
Bart Van Asschec246e802012-12-06 14:32:01 +0100165void __blk_run_queue_uncond(struct request_queue *q);
166
Adrian Bunkff889722008-03-04 11:23:45 +0100167int blk_dev_init(void);
168
Jens Axboef253b862010-10-24 22:06:02 +0200169
Jens Axboe8324aa92008-01-29 14:51:59 +0100170/*
171 * Return the threshold (number of used requests) at which the queue is
172 * considered to be congested. It include a little hysteresis to keep the
173 * context switch rate down.
174 */
175static inline int queue_congestion_on_threshold(struct request_queue *q)
176{
177 return q->nr_congestion_on;
178}
179
180/*
181 * The threshold at which a queue is considered to be uncongested
182 */
183static inline int queue_congestion_off_threshold(struct request_queue *q)
184{
185 return q->nr_congestion_off;
186}
187
Jens Axboec2553b52009-04-24 08:10:11 +0200188/*
189 * Contribute to IO statistics IFF:
190 *
191 * a) it's attached to a gendisk, and
192 * b) the queue had IO stats enabled when this request was started, and
Martin K. Petersene2a60da2012-09-18 12:19:25 -0400193 * c) it's a file system request
Jens Axboec2553b52009-04-24 08:10:11 +0200194 */
Jerome Marchand26308ea2009-03-27 10:31:51 +0100195static inline int blk_do_io_stat(struct request *rq)
Jens Axboefb8ec182009-02-02 08:42:32 +0100196{
Christoph Hellwig33659eb2010-08-07 18:17:56 +0200197 return rq->rq_disk &&
198 (rq->cmd_flags & REQ_IO_STAT) &&
Martin K. Petersene2a60da2012-09-18 12:19:25 -0400199 (rq->cmd_type == REQ_TYPE_FS);
Jens Axboefb8ec182009-02-02 08:42:32 +0100200}
201
Tejun Heof2dbd762011-12-14 00:33:40 +0100202/*
203 * Internal io_context interface
204 */
205void get_io_context(struct io_context *ioc);
Tejun Heo47fdd4c2011-12-14 00:33:42 +0100206struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
Tejun Heo24acfc32012-03-05 13:15:24 -0800207struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
208 gfp_t gfp_mask);
Tejun Heo7e5a8792011-12-14 00:33:42 +0100209void ioc_clear_queue(struct request_queue *q);
Tejun Heof2dbd762011-12-14 00:33:40 +0100210
Tejun Heo24acfc32012-03-05 13:15:24 -0800211int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
Tejun Heof2dbd762011-12-14 00:33:40 +0100212
213/**
214 * create_io_context - try to create task->io_context
Tejun Heof2dbd762011-12-14 00:33:40 +0100215 * @gfp_mask: allocation mask
216 * @node: allocation node
217 *
Tejun Heo24acfc32012-03-05 13:15:24 -0800218 * If %current->io_context is %NULL, allocate a new io_context and install
219 * it. Returns the current %current->io_context which may be %NULL if
220 * allocation failed.
Tejun Heof2dbd762011-12-14 00:33:40 +0100221 *
222 * Note that this function can't be called with IRQ disabled because
Tejun Heo24acfc32012-03-05 13:15:24 -0800223 * task_lock which protects %current->io_context is IRQ-unsafe.
Tejun Heof2dbd762011-12-14 00:33:40 +0100224 */
Tejun Heo24acfc32012-03-05 13:15:24 -0800225static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
Tejun Heof2dbd762011-12-14 00:33:40 +0100226{
227 WARN_ON_ONCE(irqs_disabled());
Tejun Heo24acfc32012-03-05 13:15:24 -0800228 if (unlikely(!current->io_context))
229 create_task_io_context(current, gfp_mask, node);
230 return current->io_context;
Tejun Heof2dbd762011-12-14 00:33:40 +0100231}
232
233/*
234 * Internal throttling interface
235 */
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200236#ifdef CONFIG_BLK_DEV_THROTTLING
Tejun Heobc16a4f2011-10-19 14:33:01 +0200237extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio);
Tejun Heoc9a929d2011-10-19 14:42:16 +0200238extern void blk_throtl_drain(struct request_queue *q);
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200239extern int blk_throtl_init(struct request_queue *q);
240extern void blk_throtl_exit(struct request_queue *q);
241#else /* CONFIG_BLK_DEV_THROTTLING */
Tejun Heobc16a4f2011-10-19 14:33:01 +0200242static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio)
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200243{
Tejun Heobc16a4f2011-10-19 14:33:01 +0200244 return false;
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200245}
Tejun Heoc9a929d2011-10-19 14:42:16 +0200246static inline void blk_throtl_drain(struct request_queue *q) { }
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200247static inline int blk_throtl_init(struct request_queue *q) { return 0; }
248static inline void blk_throtl_exit(struct request_queue *q) { }
249#endif /* CONFIG_BLK_DEV_THROTTLING */
250
251#endif /* BLK_INTERNAL_H */