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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>
Ming Leif70ced02014-09-25 23:23:47 +08005#include <linux/blk-mq.h>
6#include "blk-mq.h"
Tejun Heoa73f7302011-12-14 00:33:37 +01007
Jens Axboe86db1e22008-01-29 14:53:40 +01008/* Amount of time in which a process may batch requests */
9#define BLK_BATCH_TIME (HZ/50UL)
10
11/* Number of requests a "batching" process may submit */
12#define BLK_BATCH_REQ 32
13
Jens Axboe0d2602c2014-05-13 15:10:52 -060014/* Max future timer expiry for timeouts */
15#define BLK_MAX_TIMEOUT (5 * HZ)
16
Ming Lei7c94e1c2014-09-25 23:23:43 +080017struct blk_flush_queue {
18 unsigned int flush_queue_delayed:1;
19 unsigned int flush_pending_idx:1;
20 unsigned int flush_running_idx:1;
21 unsigned long flush_pending_since;
22 struct list_head flush_queue[2];
23 struct list_head flush_data_in_flight;
24 struct request *flush_rq;
Ming Lei0048b482015-08-09 03:41:51 -040025
26 /*
27 * flush_rq shares tag with this rq, both can't be active
28 * at the same time
29 */
30 struct request *orig_rq;
Ming Lei7c94e1c2014-09-25 23:23:43 +080031 spinlock_t mq_flush_lock;
32};
33
Jens Axboe8324aa92008-01-29 14:51:59 +010034extern struct kmem_cache *blk_requestq_cachep;
Jens Axboe320ae512013-10-24 09:20:05 +010035extern struct kmem_cache *request_cachep;
Jens Axboe8324aa92008-01-29 14:51:59 +010036extern struct kobj_type blk_queue_ktype;
Tejun Heoa73f7302011-12-14 00:33:37 +010037extern struct ida blk_queue_ida;
Jens Axboe8324aa92008-01-29 14:51:59 +010038
Ming Lei7c94e1c2014-09-25 23:23:43 +080039static inline struct blk_flush_queue *blk_get_flush_queue(
Ming Leie97c2932014-09-25 23:23:46 +080040 struct request_queue *q, struct blk_mq_ctx *ctx)
Ming Lei7c94e1c2014-09-25 23:23:43 +080041{
Ming Leif70ced02014-09-25 23:23:47 +080042 struct blk_mq_hw_ctx *hctx;
43
44 if (!q->mq_ops)
45 return q->fq;
46
47 hctx = q->mq_ops->map_queue(q, ctx->cpu);
48
49 return hctx->fq;
Ming Lei7c94e1c2014-09-25 23:23:43 +080050}
51
Tejun Heo09ac46c2011-12-14 00:33:38 +010052static inline void __blk_get_queue(struct request_queue *q)
53{
54 kobject_get(&q->kobj);
55}
56
Ming Leif70ced02014-09-25 23:23:47 +080057struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
58 int node, int cmd_size);
59void blk_free_flush_queue(struct blk_flush_queue *q);
Ming Leif3552652014-09-25 23:23:40 +080060
Tejun Heo5b788ce2012-06-04 20:40:59 -070061int blk_init_rl(struct request_list *rl, struct request_queue *q,
62 gfp_t gfp_mask);
63void blk_exit_rl(struct request_list *rl);
Jens Axboe86db1e22008-01-29 14:53:40 +010064void init_request_from_bio(struct request *req, struct bio *bio);
65void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
66 struct bio *bio);
Boaz Harrosha411f4b2009-05-17 19:00:01 +030067int blk_rq_append_bio(struct request_queue *q, struct request *rq,
68 struct bio *bio);
Tejun Heod7325802012-03-05 13:14:58 -080069void blk_queue_bypass_start(struct request_queue *q);
70void blk_queue_bypass_end(struct request_queue *q);
Tejun Heo9934c8c2009-05-08 11:54:16 +090071void blk_dequeue_request(struct request *rq);
Jens Axboe8324aa92008-01-29 14:51:59 +010072void __blk_queue_free_tags(struct request_queue *q);
Jeff Moyer4853aba2011-08-15 21:37:25 +020073bool __blk_end_bidi_request(struct request *rq, int error,
74 unsigned int nr_bytes, unsigned int bidi_bytes);
Jens Axboe8324aa92008-01-29 14:51:59 +010075
Jens Axboe242f9dc2008-09-14 05:55:09 -070076void blk_rq_timed_out_timer(unsigned long data);
Jens Axboe0d2602c2014-05-13 15:10:52 -060077unsigned long blk_rq_timeout(unsigned long timeout);
Jens Axboe87ee7b12014-04-24 08:51:47 -060078void blk_add_timer(struct request *req);
Jens Axboe242f9dc2008-09-14 05:55:09 -070079void blk_delete_timer(struct request *);
Jens Axboe242f9dc2008-09-14 05:55:09 -070080
Jens Axboe320ae512013-10-24 09:20:05 +010081
82bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
83 struct bio *bio);
84bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
85 struct bio *bio);
86bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
Shaohua Li5b3f3412015-05-08 10:51:33 -070087 unsigned int *request_count,
88 struct request **same_queue_rq);
Jens Axboe320ae512013-10-24 09:20:05 +010089
90void blk_account_io_start(struct request *req, bool new_io);
91void blk_account_io_completion(struct request *req, unsigned int bytes);
92void blk_account_io_done(struct request *req);
93
Jens Axboe242f9dc2008-09-14 05:55:09 -070094/*
95 * Internal atomic flags for request handling
96 */
97enum rq_atomic_flags {
98 REQ_ATOM_COMPLETE = 0,
Jens Axboe320ae512013-10-24 09:20:05 +010099 REQ_ATOM_STARTED,
Jens Axboe242f9dc2008-09-14 05:55:09 -0700100};
101
102/*
103 * EH timer and IO completion will both attempt to 'grab' the request, make
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300104 * sure that only one of them succeeds
Jens Axboe242f9dc2008-09-14 05:55:09 -0700105 */
106static inline int blk_mark_rq_complete(struct request *rq)
107{
108 return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
109}
110
111static inline void blk_clear_rq_complete(struct request *rq)
112{
113 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
114}
Jens Axboe86db1e22008-01-29 14:53:40 +0100115
Tejun Heo158dbda2009-04-23 11:05:18 +0900116/*
117 * Internal elevator interface
118 */
Jens Axboe360f92c2014-04-09 20:27:01 -0600119#define ELV_ON_HASH(rq) ((rq)->cmd_flags & REQ_HASHED)
Tejun Heo158dbda2009-04-23 11:05:18 +0900120
Tejun Heoae1b1532011-01-25 12:43:54 +0100121void blk_insert_flush(struct request *rq);
Tejun Heodd831002010-09-03 11:56:16 +0200122
Tejun Heo158dbda2009-04-23 11:05:18 +0900123static inline struct request *__elv_next_request(struct request_queue *q)
124{
125 struct request *rq;
Ming Leie97c2932014-09-25 23:23:46 +0800126 struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL);
Tejun Heo158dbda2009-04-23 11:05:18 +0900127
128 while (1) {
Tejun Heoae1b1532011-01-25 12:43:54 +0100129 if (!list_empty(&q->queue_head)) {
Tejun Heo158dbda2009-04-23 11:05:18 +0900130 rq = list_entry_rq(q->queue_head.next);
Tejun Heoae1b1532011-01-25 12:43:54 +0100131 return rq;
Tejun Heo158dbda2009-04-23 11:05:18 +0900132 }
133
shaohua.li@intel.com3ac0cc42011-05-06 11:34:41 -0600134 /*
135 * Flush request is running and flush request isn't queueable
136 * in the drive, we can hold the queue till flush request is
137 * finished. Even we don't do this, driver can't dispatch next
138 * requests and will requeue them. And this can improve
139 * throughput too. For example, we have request flush1, write1,
140 * flush 2. flush1 is dispatched, then queue is hold, write1
141 * isn't inserted to queue. After flush1 is finished, flush2
142 * will be dispatched. Since disk cache is already clean,
143 * flush2 will be finished very soon, so looks like flush2 is
144 * folded to flush1.
145 * Since the queue is hold, a flag is set to indicate the queue
146 * should be restarted later. Please see flush_end_io() for
147 * details.
148 */
Ming Lei7c94e1c2014-09-25 23:23:43 +0800149 if (fq->flush_pending_idx != fq->flush_running_idx &&
shaohua.li@intel.com3ac0cc42011-05-06 11:34:41 -0600150 !queue_flush_queueable(q)) {
Ming Lei7c94e1c2014-09-25 23:23:43 +0800151 fq->flush_queue_delayed = 1;
shaohua.li@intel.com3ac0cc42011-05-06 11:34:41 -0600152 return NULL;
153 }
Tejun Heo556ee812014-01-29 14:56:16 -0700154 if (unlikely(blk_queue_bypass(q)) ||
Tejun Heo22f746e2011-12-14 00:33:41 +0100155 !q->elevator->type->ops.elevator_dispatch_fn(q, 0))
Tejun Heo158dbda2009-04-23 11:05:18 +0900156 return NULL;
157 }
158}
159
160static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
161{
162 struct elevator_queue *e = q->elevator;
163
Tejun Heo22f746e2011-12-14 00:33:41 +0100164 if (e->type->ops.elevator_activate_req_fn)
165 e->type->ops.elevator_activate_req_fn(q, rq);
Tejun Heo158dbda2009-04-23 11:05:18 +0900166}
167
168static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
169{
170 struct elevator_queue *e = q->elevator;
171
Tejun Heo22f746e2011-12-14 00:33:41 +0100172 if (e->type->ops.elevator_deactivate_req_fn)
173 e->type->ops.elevator_deactivate_req_fn(q, rq);
Tejun Heo158dbda2009-04-23 11:05:18 +0900174}
175
Jens Axboe581d4e22008-09-14 05:56:33 -0700176#ifdef CONFIG_FAIL_IO_TIMEOUT
177int blk_should_fake_timeout(struct request_queue *);
178ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
179ssize_t part_timeout_store(struct device *, struct device_attribute *,
180 const char *, size_t);
181#else
182static inline int blk_should_fake_timeout(struct request_queue *q)
183{
184 return 0;
185}
186#endif
187
Jens Axboed6d48192008-01-29 14:04:06 +0100188int ll_back_merge_fn(struct request_queue *q, struct request *req,
189 struct bio *bio);
190int ll_front_merge_fn(struct request_queue *q, struct request *req,
191 struct bio *bio);
192int attempt_back_merge(struct request_queue *q, struct request *rq);
193int attempt_front_merge(struct request_queue *q, struct request *rq);
Jens Axboe5e84ea32011-03-21 10:14:27 +0100194int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
195 struct request *next);
Jens Axboed6d48192008-01-29 14:04:06 +0100196void blk_recalc_rq_segments(struct request *rq);
Tejun Heo80a761f2009-07-03 17:48:17 +0900197void blk_rq_set_mixed_merge(struct request *rq);
Tejun Heo050c8ea2012-02-08 09:19:38 +0100198bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
199int blk_try_merge(struct request *rq, struct bio *bio);
Jens Axboed6d48192008-01-29 14:04:06 +0100200
Jens Axboe8324aa92008-01-29 14:51:59 +0100201void blk_queue_congestion_threshold(struct request_queue *q);
202
Adrian Bunkff889722008-03-04 11:23:45 +0100203int blk_dev_init(void);
204
Jens Axboef253b862010-10-24 22:06:02 +0200205
Jens Axboe8324aa92008-01-29 14:51:59 +0100206/*
207 * Return the threshold (number of used requests) at which the queue is
208 * considered to be congested. It include a little hysteresis to keep the
209 * context switch rate down.
210 */
211static inline int queue_congestion_on_threshold(struct request_queue *q)
212{
213 return q->nr_congestion_on;
214}
215
216/*
217 * The threshold at which a queue is considered to be uncongested
218 */
219static inline int queue_congestion_off_threshold(struct request_queue *q)
220{
221 return q->nr_congestion_off;
222}
223
Jens Axboee3a2b3f2014-05-20 11:49:02 -0600224extern int blk_update_nr_requests(struct request_queue *, unsigned int);
225
Jens Axboec2553b52009-04-24 08:10:11 +0200226/*
227 * Contribute to IO statistics IFF:
228 *
229 * a) it's attached to a gendisk, and
230 * b) the queue had IO stats enabled when this request was started, and
Martin K. Petersene2a60da2012-09-18 12:19:25 -0400231 * c) it's a file system request
Jens Axboec2553b52009-04-24 08:10:11 +0200232 */
Jerome Marchand26308ea2009-03-27 10:31:51 +0100233static inline int blk_do_io_stat(struct request *rq)
Jens Axboefb8ec182009-02-02 08:42:32 +0100234{
Christoph Hellwig33659eb2010-08-07 18:17:56 +0200235 return rq->rq_disk &&
236 (rq->cmd_flags & REQ_IO_STAT) &&
Martin K. Petersene2a60da2012-09-18 12:19:25 -0400237 (rq->cmd_type == REQ_TYPE_FS);
Jens Axboefb8ec182009-02-02 08:42:32 +0100238}
239
Tejun Heof2dbd762011-12-14 00:33:40 +0100240/*
241 * Internal io_context interface
242 */
243void get_io_context(struct io_context *ioc);
Tejun Heo47fdd4c2011-12-14 00:33:42 +0100244struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
Tejun Heo24acfc32012-03-05 13:15:24 -0800245struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
246 gfp_t gfp_mask);
Tejun Heo7e5a8792011-12-14 00:33:42 +0100247void ioc_clear_queue(struct request_queue *q);
Tejun Heof2dbd762011-12-14 00:33:40 +0100248
Tejun Heo24acfc32012-03-05 13:15:24 -0800249int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
Tejun Heof2dbd762011-12-14 00:33:40 +0100250
251/**
252 * create_io_context - try to create task->io_context
Tejun Heof2dbd762011-12-14 00:33:40 +0100253 * @gfp_mask: allocation mask
254 * @node: allocation node
255 *
Tejun Heo24acfc32012-03-05 13:15:24 -0800256 * If %current->io_context is %NULL, allocate a new io_context and install
257 * it. Returns the current %current->io_context which may be %NULL if
258 * allocation failed.
Tejun Heof2dbd762011-12-14 00:33:40 +0100259 *
260 * Note that this function can't be called with IRQ disabled because
Tejun Heo24acfc32012-03-05 13:15:24 -0800261 * task_lock which protects %current->io_context is IRQ-unsafe.
Tejun Heof2dbd762011-12-14 00:33:40 +0100262 */
Tejun Heo24acfc32012-03-05 13:15:24 -0800263static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
Tejun Heof2dbd762011-12-14 00:33:40 +0100264{
265 WARN_ON_ONCE(irqs_disabled());
Tejun Heo24acfc32012-03-05 13:15:24 -0800266 if (unlikely(!current->io_context))
267 create_task_io_context(current, gfp_mask, node);
268 return current->io_context;
Tejun Heof2dbd762011-12-14 00:33:40 +0100269}
270
271/*
272 * Internal throttling interface
273 */
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200274#ifdef CONFIG_BLK_DEV_THROTTLING
Tejun Heobc16a4f2011-10-19 14:33:01 +0200275extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio);
Tejun Heoc9a929d2011-10-19 14:42:16 +0200276extern void blk_throtl_drain(struct request_queue *q);
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200277extern int blk_throtl_init(struct request_queue *q);
278extern void blk_throtl_exit(struct request_queue *q);
279#else /* CONFIG_BLK_DEV_THROTTLING */
Tejun Heobc16a4f2011-10-19 14:33:01 +0200280static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio)
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200281{
Tejun Heobc16a4f2011-10-19 14:33:01 +0200282 return false;
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200283}
Tejun Heoc9a929d2011-10-19 14:42:16 +0200284static inline void blk_throtl_drain(struct request_queue *q) { }
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200285static inline int blk_throtl_init(struct request_queue *q) { return 0; }
286static inline void blk_throtl_exit(struct request_queue *q) { }
287#endif /* CONFIG_BLK_DEV_THROTTLING */
288
289#endif /* BLK_INTERNAL_H */