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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);
Dan Williams3ef28e82015-10-21 13:20:12 -040075void blk_freeze_queue(struct request_queue *q);
76
77static inline void blk_queue_enter_live(struct request_queue *q)
78{
79 /*
80 * Given that running in generic_make_request() context
81 * guarantees that a live reference against q_usage_counter has
82 * been established, further references under that same context
83 * need not check that the queue has been frozen (marked dead).
84 */
85 percpu_ref_get(&q->q_usage_counter);
86}
Jens Axboe8324aa92008-01-29 14:51:59 +010087
Dan Williams5a48fc12015-10-21 13:20:23 -040088#ifdef CONFIG_BLK_DEV_INTEGRITY
89void blk_flush_integrity(void);
90#else
91static inline void blk_flush_integrity(void)
92{
93}
94#endif
Jens Axboe8324aa92008-01-29 14:51:59 +010095
Christoph Hellwig287922e2015-10-30 20:57:30 +080096void blk_timeout_work(struct work_struct *work);
Jens Axboe0d2602c2014-05-13 15:10:52 -060097unsigned long blk_rq_timeout(unsigned long timeout);
Jens Axboe87ee7b12014-04-24 08:51:47 -060098void blk_add_timer(struct request *req);
Jens Axboe242f9dc2008-09-14 05:55:09 -070099void blk_delete_timer(struct request *);
Jens Axboe242f9dc2008-09-14 05:55:09 -0700100
Jens Axboe320ae512013-10-24 09:20:05 +0100101
102bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
103 struct bio *bio);
104bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
105 struct bio *bio);
106bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
Shaohua Li5b3f3412015-05-08 10:51:33 -0700107 unsigned int *request_count,
108 struct request **same_queue_rq);
Jeff Moyer0809e3a2015-10-20 23:13:51 +0800109unsigned int blk_plug_queued_count(struct request_queue *q);
Jens Axboe320ae512013-10-24 09:20:05 +0100110
111void blk_account_io_start(struct request *req, bool new_io);
112void blk_account_io_completion(struct request *req, unsigned int bytes);
113void blk_account_io_done(struct request *req);
114
Jens Axboe242f9dc2008-09-14 05:55:09 -0700115/*
116 * Internal atomic flags for request handling
117 */
118enum rq_atomic_flags {
119 REQ_ATOM_COMPLETE = 0,
Jens Axboe320ae512013-10-24 09:20:05 +0100120 REQ_ATOM_STARTED,
Jens Axboe242f9dc2008-09-14 05:55:09 -0700121};
122
123/*
124 * EH timer and IO completion will both attempt to 'grab' the request, make
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300125 * sure that only one of them succeeds
Jens Axboe242f9dc2008-09-14 05:55:09 -0700126 */
127static inline int blk_mark_rq_complete(struct request *rq)
128{
129 return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
130}
131
132static inline void blk_clear_rq_complete(struct request *rq)
133{
134 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
135}
Jens Axboe86db1e22008-01-29 14:53:40 +0100136
Tejun Heo158dbda2009-04-23 11:05:18 +0900137/*
138 * Internal elevator interface
139 */
Jens Axboe360f92c2014-04-09 20:27:01 -0600140#define ELV_ON_HASH(rq) ((rq)->cmd_flags & REQ_HASHED)
Tejun Heo158dbda2009-04-23 11:05:18 +0900141
Tejun Heoae1b1532011-01-25 12:43:54 +0100142void blk_insert_flush(struct request *rq);
Tejun Heodd831002010-09-03 11:56:16 +0200143
Tejun Heo158dbda2009-04-23 11:05:18 +0900144static inline struct request *__elv_next_request(struct request_queue *q)
145{
146 struct request *rq;
Ming Leie97c2932014-09-25 23:23:46 +0800147 struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL);
Tejun Heo158dbda2009-04-23 11:05:18 +0900148
149 while (1) {
Tejun Heoae1b1532011-01-25 12:43:54 +0100150 if (!list_empty(&q->queue_head)) {
Tejun Heo158dbda2009-04-23 11:05:18 +0900151 rq = list_entry_rq(q->queue_head.next);
Tejun Heoae1b1532011-01-25 12:43:54 +0100152 return rq;
Tejun Heo158dbda2009-04-23 11:05:18 +0900153 }
154
shaohua.li@intel.com3ac0cc42011-05-06 11:34:41 -0600155 /*
156 * Flush request is running and flush request isn't queueable
157 * in the drive, we can hold the queue till flush request is
158 * finished. Even we don't do this, driver can't dispatch next
159 * requests and will requeue them. And this can improve
160 * throughput too. For example, we have request flush1, write1,
161 * flush 2. flush1 is dispatched, then queue is hold, write1
162 * isn't inserted to queue. After flush1 is finished, flush2
163 * will be dispatched. Since disk cache is already clean,
164 * flush2 will be finished very soon, so looks like flush2 is
165 * folded to flush1.
166 * Since the queue is hold, a flag is set to indicate the queue
167 * should be restarted later. Please see flush_end_io() for
168 * details.
169 */
Ming Lei7c94e1c2014-09-25 23:23:43 +0800170 if (fq->flush_pending_idx != fq->flush_running_idx &&
shaohua.li@intel.com3ac0cc42011-05-06 11:34:41 -0600171 !queue_flush_queueable(q)) {
Ming Lei7c94e1c2014-09-25 23:23:43 +0800172 fq->flush_queue_delayed = 1;
shaohua.li@intel.com3ac0cc42011-05-06 11:34:41 -0600173 return NULL;
174 }
Tejun Heo556ee812014-01-29 14:56:16 -0700175 if (unlikely(blk_queue_bypass(q)) ||
Tejun Heo22f746e2011-12-14 00:33:41 +0100176 !q->elevator->type->ops.elevator_dispatch_fn(q, 0))
Tejun Heo158dbda2009-04-23 11:05:18 +0900177 return NULL;
178 }
179}
180
181static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
182{
183 struct elevator_queue *e = q->elevator;
184
Tejun Heo22f746e2011-12-14 00:33:41 +0100185 if (e->type->ops.elevator_activate_req_fn)
186 e->type->ops.elevator_activate_req_fn(q, rq);
Tejun Heo158dbda2009-04-23 11:05:18 +0900187}
188
189static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
190{
191 struct elevator_queue *e = q->elevator;
192
Tejun Heo22f746e2011-12-14 00:33:41 +0100193 if (e->type->ops.elevator_deactivate_req_fn)
194 e->type->ops.elevator_deactivate_req_fn(q, rq);
Tejun Heo158dbda2009-04-23 11:05:18 +0900195}
196
Jens Axboe581d4e22008-09-14 05:56:33 -0700197#ifdef CONFIG_FAIL_IO_TIMEOUT
198int blk_should_fake_timeout(struct request_queue *);
199ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
200ssize_t part_timeout_store(struct device *, struct device_attribute *,
201 const char *, size_t);
202#else
203static inline int blk_should_fake_timeout(struct request_queue *q)
204{
205 return 0;
206}
207#endif
208
Jens Axboed6d48192008-01-29 14:04:06 +0100209int ll_back_merge_fn(struct request_queue *q, struct request *req,
210 struct bio *bio);
211int ll_front_merge_fn(struct request_queue *q, struct request *req,
212 struct bio *bio);
213int attempt_back_merge(struct request_queue *q, struct request *rq);
214int attempt_front_merge(struct request_queue *q, struct request *rq);
Jens Axboe5e84ea32011-03-21 10:14:27 +0100215int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
216 struct request *next);
Jens Axboed6d48192008-01-29 14:04:06 +0100217void blk_recalc_rq_segments(struct request *rq);
Tejun Heo80a761f2009-07-03 17:48:17 +0900218void blk_rq_set_mixed_merge(struct request *rq);
Tejun Heo050c8ea2012-02-08 09:19:38 +0100219bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
220int blk_try_merge(struct request *rq, struct bio *bio);
Jens Axboed6d48192008-01-29 14:04:06 +0100221
Jens Axboe8324aa92008-01-29 14:51:59 +0100222void blk_queue_congestion_threshold(struct request_queue *q);
223
Adrian Bunkff889722008-03-04 11:23:45 +0100224int blk_dev_init(void);
225
Jens Axboef253b862010-10-24 22:06:02 +0200226
Jens Axboe8324aa92008-01-29 14:51:59 +0100227/*
228 * Return the threshold (number of used requests) at which the queue is
229 * considered to be congested. It include a little hysteresis to keep the
230 * context switch rate down.
231 */
232static inline int queue_congestion_on_threshold(struct request_queue *q)
233{
234 return q->nr_congestion_on;
235}
236
237/*
238 * The threshold at which a queue is considered to be uncongested
239 */
240static inline int queue_congestion_off_threshold(struct request_queue *q)
241{
242 return q->nr_congestion_off;
243}
244
Jens Axboee3a2b3f2014-05-20 11:49:02 -0600245extern int blk_update_nr_requests(struct request_queue *, unsigned int);
246
Jens Axboec2553b52009-04-24 08:10:11 +0200247/*
248 * Contribute to IO statistics IFF:
249 *
250 * a) it's attached to a gendisk, and
251 * b) the queue had IO stats enabled when this request was started, and
Martin K. Petersene2a60da2012-09-18 12:19:25 -0400252 * c) it's a file system request
Jens Axboec2553b52009-04-24 08:10:11 +0200253 */
Jerome Marchand26308ea2009-03-27 10:31:51 +0100254static inline int blk_do_io_stat(struct request *rq)
Jens Axboefb8ec182009-02-02 08:42:32 +0100255{
Christoph Hellwig33659eb2010-08-07 18:17:56 +0200256 return rq->rq_disk &&
257 (rq->cmd_flags & REQ_IO_STAT) &&
Martin K. Petersene2a60da2012-09-18 12:19:25 -0400258 (rq->cmd_type == REQ_TYPE_FS);
Jens Axboefb8ec182009-02-02 08:42:32 +0100259}
260
Tejun Heof2dbd762011-12-14 00:33:40 +0100261/*
262 * Internal io_context interface
263 */
264void get_io_context(struct io_context *ioc);
Tejun Heo47fdd4c2011-12-14 00:33:42 +0100265struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
Tejun Heo24acfc32012-03-05 13:15:24 -0800266struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
267 gfp_t gfp_mask);
Tejun Heo7e5a8792011-12-14 00:33:42 +0100268void ioc_clear_queue(struct request_queue *q);
Tejun Heof2dbd762011-12-14 00:33:40 +0100269
Tejun Heo24acfc32012-03-05 13:15:24 -0800270int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
Tejun Heof2dbd762011-12-14 00:33:40 +0100271
272/**
273 * create_io_context - try to create task->io_context
Tejun Heof2dbd762011-12-14 00:33:40 +0100274 * @gfp_mask: allocation mask
275 * @node: allocation node
276 *
Tejun Heo24acfc32012-03-05 13:15:24 -0800277 * If %current->io_context is %NULL, allocate a new io_context and install
278 * it. Returns the current %current->io_context which may be %NULL if
279 * allocation failed.
Tejun Heof2dbd762011-12-14 00:33:40 +0100280 *
281 * Note that this function can't be called with IRQ disabled because
Tejun Heo24acfc32012-03-05 13:15:24 -0800282 * task_lock which protects %current->io_context is IRQ-unsafe.
Tejun Heof2dbd762011-12-14 00:33:40 +0100283 */
Tejun Heo24acfc32012-03-05 13:15:24 -0800284static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
Tejun Heof2dbd762011-12-14 00:33:40 +0100285{
286 WARN_ON_ONCE(irqs_disabled());
Tejun Heo24acfc32012-03-05 13:15:24 -0800287 if (unlikely(!current->io_context))
288 create_task_io_context(current, gfp_mask, node);
289 return current->io_context;
Tejun Heof2dbd762011-12-14 00:33:40 +0100290}
291
292/*
293 * Internal throttling interface
294 */
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200295#ifdef CONFIG_BLK_DEV_THROTTLING
Tejun Heoc9a929d2011-10-19 14:42:16 +0200296extern void blk_throtl_drain(struct request_queue *q);
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200297extern int blk_throtl_init(struct request_queue *q);
298extern void blk_throtl_exit(struct request_queue *q);
299#else /* CONFIG_BLK_DEV_THROTTLING */
Tejun Heoc9a929d2011-10-19 14:42:16 +0200300static inline void blk_throtl_drain(struct request_queue *q) { }
Tejun Heobc9fcbf2011-10-19 14:31:18 +0200301static inline int blk_throtl_init(struct request_queue *q) { return 0; }
302static inline void blk_throtl_exit(struct request_queue *q) { }
303#endif /* CONFIG_BLK_DEV_THROTTLING */
304
305#endif /* BLK_INTERNAL_H */