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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 Axboe0d2602c2014-05-13 15:10:52 -060012/* Max future timer expiry for timeouts */
13#define BLK_MAX_TIMEOUT (5 * HZ)
14
Jens Axboe8324aa92008-01-29 14:51:59 +010015extern struct kmem_cache *blk_requestq_cachep;
Jens Axboe320ae512013-10-24 09:20:05 +010016extern struct kmem_cache *request_cachep;
Jens Axboe8324aa92008-01-29 14:51:59 +010017extern struct kobj_type blk_queue_ktype;
Tejun Heoa73f7302011-12-14 00:33:37 +010018extern struct ida blk_queue_ida;
Jens Axboe8324aa92008-01-29 14:51:59 +010019
Tejun Heo09ac46c2011-12-14 00:33:38 +010020static inline void __blk_get_queue(struct request_queue *q)
21{
22 kobject_get(&q->kobj);
23}
24
Tejun Heo5b788ce2012-06-04 20:40:59 -070025int blk_init_rl(struct request_list *rl, struct request_queue *q,
26 gfp_t gfp_mask);
27void blk_exit_rl(struct request_list *rl);
Jens Axboe86db1e22008-01-29 14:53:40 +010028void init_request_from_bio(struct request *req, struct bio *bio);
29void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
30 struct bio *bio);
Boaz Harrosha411f4b2009-05-17 19:00:01 +030031int blk_rq_append_bio(struct request_queue *q, struct request *rq,
32 struct bio *bio);
Tejun Heod7325802012-03-05 13:14:58 -080033void blk_queue_bypass_start(struct request_queue *q);
34void blk_queue_bypass_end(struct request_queue *q);
Tejun Heo9934c8c2009-05-08 11:54:16 +090035void blk_dequeue_request(struct request *rq);
Jens Axboe8324aa92008-01-29 14:51:59 +010036void __blk_queue_free_tags(struct request_queue *q);
Jeff Moyer4853aba2011-08-15 21:37:25 +020037bool __blk_end_bidi_request(struct request *rq, int error,
38 unsigned int nr_bytes, unsigned int bidi_bytes);
Jens Axboe8324aa92008-01-29 14:51:59 +010039
Jens Axboe242f9dc2008-09-14 05:55:09 -070040void blk_rq_timed_out_timer(unsigned long data);
Jens Axboe320ae512013-10-24 09:20:05 +010041void blk_rq_check_expired(struct request *rq, unsigned long *next_timeout,
42 unsigned int *next_set);
Jens Axboe0d2602c2014-05-13 15:10:52 -060043unsigned long blk_rq_timeout(unsigned long timeout);
Jens Axboe87ee7b12014-04-24 08:51:47 -060044void blk_add_timer(struct request *req);
Jens Axboe242f9dc2008-09-14 05:55:09 -070045void blk_delete_timer(struct request *);
Jens Axboe242f9dc2008-09-14 05:55:09 -070046
Jens Axboe320ae512013-10-24 09:20:05 +010047
48bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
49 struct bio *bio);
50bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
51 struct bio *bio);
52bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
53 unsigned int *request_count);
54
55void blk_account_io_start(struct request *req, bool new_io);
56void blk_account_io_completion(struct request *req, unsigned int bytes);
57void blk_account_io_done(struct request *req);
58
Jens Axboe242f9dc2008-09-14 05:55:09 -070059/*
60 * Internal atomic flags for request handling
61 */
62enum rq_atomic_flags {
63 REQ_ATOM_COMPLETE = 0,
Jens Axboe320ae512013-10-24 09:20:05 +010064 REQ_ATOM_STARTED,
Jens Axboe242f9dc2008-09-14 05:55:09 -070065};
66
67/*
68 * EH timer and IO completion will both attempt to 'grab' the request, make
Lucas De Marchi25985ed2011-03-30 22:57:33 -030069 * sure that only one of them succeeds
Jens Axboe242f9dc2008-09-14 05:55:09 -070070 */
71static inline int blk_mark_rq_complete(struct request *rq)
72{
73 return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
74}
75
76static inline void blk_clear_rq_complete(struct request *rq)
77{
78 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
79}
Jens Axboe86db1e22008-01-29 14:53:40 +010080
Tejun Heo158dbda2009-04-23 11:05:18 +090081/*
82 * Internal elevator interface
83 */
Jens Axboe360f92c2014-04-09 20:27:01 -060084#define ELV_ON_HASH(rq) ((rq)->cmd_flags & REQ_HASHED)
Tejun Heo158dbda2009-04-23 11:05:18 +090085
Tejun Heoae1b1532011-01-25 12:43:54 +010086void blk_insert_flush(struct request *rq);
87void blk_abort_flushes(struct request_queue *q);
Tejun Heodd831002010-09-03 11:56:16 +020088
Tejun Heo158dbda2009-04-23 11:05:18 +090089static inline struct request *__elv_next_request(struct request_queue *q)
90{
91 struct request *rq;
92
93 while (1) {
Tejun Heoae1b1532011-01-25 12:43:54 +010094 if (!list_empty(&q->queue_head)) {
Tejun Heo158dbda2009-04-23 11:05:18 +090095 rq = list_entry_rq(q->queue_head.next);
Tejun Heoae1b1532011-01-25 12:43:54 +010096 return rq;
Tejun Heo158dbda2009-04-23 11:05:18 +090097 }
98
shaohua.li@intel.com3ac0cc42011-05-06 11:34:41 -060099 /*
100 * Flush request is running and flush request isn't queueable
101 * in the drive, we can hold the queue till flush request is
102 * finished. Even we don't do this, driver can't dispatch next
103 * requests and will requeue them. And this can improve
104 * throughput too. For example, we have request flush1, write1,
105 * flush 2. flush1 is dispatched, then queue is hold, write1
106 * isn't inserted to queue. After flush1 is finished, flush2
107 * will be dispatched. Since disk cache is already clean,
108 * flush2 will be finished very soon, so looks like flush2 is
109 * folded to flush1.
110 * Since the queue is hold, a flag is set to indicate the queue
111 * should be restarted later. Please see flush_end_io() for
112 * details.
113 */
114 if (q->flush_pending_idx != q->flush_running_idx &&
115 !queue_flush_queueable(q)) {
116 q->flush_queue_delayed = 1;
117 return NULL;
118 }
Tejun Heo556ee812014-01-29 14:56:16 -0700119 if (unlikely(blk_queue_bypass(q)) ||
Tejun Heo22f746e2011-12-14 00:33:41 +0100120 !q->elevator->type->ops.elevator_dispatch_fn(q, 0))
Tejun Heo158dbda2009-04-23 11:05:18 +0900121 return NULL;
122 }
123}
124
125static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
126{
127 struct elevator_queue *e = q->elevator;
128
Tejun Heo22f746e2011-12-14 00:33:41 +0100129 if (e->type->ops.elevator_activate_req_fn)
130 e->type->ops.elevator_activate_req_fn(q, rq);
Tejun Heo158dbda2009-04-23 11:05:18 +0900131}
132
133static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
134{
135 struct elevator_queue *e = q->elevator;
136
Tejun Heo22f746e2011-12-14 00:33:41 +0100137 if (e->type->ops.elevator_deactivate_req_fn)
138 e->type->ops.elevator_deactivate_req_fn(q, rq);
Tejun Heo158dbda2009-04-23 11:05:18 +0900139}
140
Jens Axboe581d4e22008-09-14 05:56:33 -0700141#ifdef CONFIG_FAIL_IO_TIMEOUT
142int blk_should_fake_timeout(struct request_queue *);
143ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
144ssize_t part_timeout_store(struct device *, struct device_attribute *,
145 const char *, size_t);
146#else
147static inline int blk_should_fake_timeout(struct request_queue *q)
148{
149 return 0;
150}
151#endif
152
Jens Axboed6d48192008-01-29 14:04:06 +0100153int ll_back_merge_fn(struct request_queue *q, struct request *req,
154 struct bio *bio);
155int ll_front_merge_fn(struct request_queue *q, struct request *req,
156 struct bio *bio);
157int attempt_back_merge(struct request_queue *q, struct request *rq);
158int attempt_front_merge(struct request_queue *q, struct request *rq);
Jens Axboe5e84ea32011-03-21 10:14:27 +0100159int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
160 struct request *next);
Jens Axboed6d48192008-01-29 14:04:06 +0100161void blk_recalc_rq_segments(struct request *rq);
Tejun Heo80a761f2009-07-03 17:48:17 +0900162void blk_rq_set_mixed_merge(struct request *rq);
Tejun Heo050c8ea2012-02-08 09:19:38 +0100163bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
164int blk_try_merge(struct request *rq, struct bio *bio);
Jens Axboed6d48192008-01-29 14:04:06 +0100165
Jens Axboe8324aa92008-01-29 14:51:59 +0100166void blk_queue_congestion_threshold(struct request_queue *q);
167
Bart Van Asschec246e802012-12-06 14:32:01 +0100168void __blk_run_queue_uncond(struct request_queue *q);
169
Adrian Bunkff889722008-03-04 11:23:45 +0100170int blk_dev_init(void);
171
Jens Axboef253b862010-10-24 22:06:02 +0200172
Jens Axboe8324aa92008-01-29 14:51:59 +0100173/*
174 * Return the threshold (number of used requests) at which the queue is
175 * considered to be congested. It include a little hysteresis to keep the
176 * context switch rate down.
177 */
178static inline int queue_congestion_on_threshold(struct request_queue *q)
179{
180 return q->nr_congestion_on;
181}
182
183/*
184 * The threshold at which a queue is considered to be uncongested
185 */
186static inline int queue_congestion_off_threshold(struct request_queue *q)
187{
188 return q->nr_congestion_off;
189}
190
Jens Axboee3a2b3f2014-05-20 11:49:02 -0600191extern int blk_update_nr_requests(struct request_queue *, unsigned int);
192
Jens Axboec2553b52009-04-24 08:10:11 +0200193/*
194 * Contribute to IO statistics IFF:
195 *
196 * a) it's attached to a gendisk, and
197 * b) the queue had IO stats enabled when this request was started, and
Martin K. Petersene2a60da2012-09-18 12:19:25 -0400198 * c) it's a file system request
Jens Axboec2553b52009-04-24 08:10:11 +0200199 */
Jerome Marchand26308ea2009-03-27 10:31:51 +0100200static inline int blk_do_io_stat(struct request *rq)
Jens Axboefb8ec182009-02-02 08:42:32 +0100201{
Christoph Hellwig33659eb2010-08-07 18:17:56 +0200202 return rq->rq_disk &&
203 (rq->cmd_flags & REQ_IO_STAT) &&
Martin K. Petersene2a60da2012-09-18 12:19:25 -0400204 (rq->cmd_type == REQ_TYPE_FS);
Jens Axboefb8ec182009-02-02 08:42:32 +0100205}
206
Tejun Heof2dbd762011-12-14 00:33:40 +0100207/*
208 * Internal io_context interface
209 */
210void get_io_context(struct io_context *ioc);
Tejun Heo47fdd4c2011-12-14 00:33:42 +0100211struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
Tejun Heo24acfc32012-03-05 13:15:24 -0800212struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
213 gfp_t gfp_mask);
Tejun Heo7e5a8792011-12-14 00:33:42 +0100214void ioc_clear_queue(struct request_queue *q);
Tejun Heof2dbd762011-12-14 00:33:40 +0100215
Tejun Heo24acfc32012-03-05 13:15:24 -0800216int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
Tejun Heof2dbd762011-12-14 00:33:40 +0100217
218/**
219 * create_io_context - try to create task->io_context
Tejun Heof2dbd762011-12-14 00:33:40 +0100220 * @gfp_mask: allocation mask
221 * @node: allocation node
222 *
Tejun Heo24acfc32012-03-05 13:15:24 -0800223 * If %current->io_context is %NULL, allocate a new io_context and install
224 * it. Returns the current %current->io_context which may be %NULL if
225 * allocation failed.
Tejun Heof2dbd762011-12-14 00:33:40 +0100226 *
227 * Note that this function can't be called with IRQ disabled because
Tejun Heo24acfc32012-03-05 13:15:24 -0800228 * task_lock which protects %current->io_context is IRQ-unsafe.
Tejun Heof2dbd762011-12-14 00:33:40 +0100229 */
Tejun Heo24acfc32012-03-05 13:15:24 -0800230static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
Tejun Heof2dbd762011-12-14 00:33:40 +0100231{
232 WARN_ON_ONCE(irqs_disabled());
Tejun Heo24acfc32012-03-05 13:15:24 -0800233 if (unlikely(!current->io_context))
234 create_task_io_context(current, gfp_mask, node);
235 return current->io_context;
Tejun Heof2dbd762011-12-14 00:33:40 +0100236}
237
238/*
239 * Internal throttling interface
240 */
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200241#ifdef CONFIG_BLK_DEV_THROTTLING
Tejun Heobc16a4f2011-10-19 14:33:01 +0200242extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio);
Tejun Heoc9a929d2011-10-19 14:42:16 +0200243extern void blk_throtl_drain(struct request_queue *q);
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200244extern int blk_throtl_init(struct request_queue *q);
245extern void blk_throtl_exit(struct request_queue *q);
246#else /* CONFIG_BLK_DEV_THROTTLING */
Tejun Heobc16a4f2011-10-19 14:33:01 +0200247static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio)
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200248{
Tejun Heobc16a4f2011-10-19 14:33:01 +0200249 return false;
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200250}
Tejun Heoc9a929d2011-10-19 14:42:16 +0200251static inline void blk_throtl_drain(struct request_queue *q) { }
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200252static inline int blk_throtl_init(struct request_queue *q) { return 0; }
253static inline void blk_throtl_exit(struct request_queue *q) { }
254#endif /* CONFIG_BLK_DEV_THROTTLING */
255
256#endif /* BLK_INTERNAL_H */