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1#ifndef BLK_INTERNAL_H
2#define BLK_INTERNAL_H
3
a73f730d 4#include <linux/idr.h>
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5#include <linux/blk-mq.h>
6#include "blk-mq.h"
a73f730d 7
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8/* 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
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14/* Max future timer expiry for timeouts */
15#define BLK_MAX_TIMEOUT (5 * HZ)
16
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17struct 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;
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25
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;
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31 spinlock_t mq_flush_lock;
32};
33
8324aa91 34extern struct kmem_cache *blk_requestq_cachep;
320ae51f 35extern struct kmem_cache *request_cachep;
8324aa91 36extern struct kobj_type blk_queue_ktype;
a73f730d 37extern struct ida blk_queue_ida;
8324aa91 38
7c94e1c1 39static inline struct blk_flush_queue *blk_get_flush_queue(
e97c293c 40 struct request_queue *q, struct blk_mq_ctx *ctx)
7c94e1c1 41{
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42 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;
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50}
51
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52static inline void __blk_get_queue(struct request_queue *q)
53{
54 kobject_get(&q->kobj);
55}
56
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57struct 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);
f3552655 60
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61int blk_init_rl(struct request_list *rl, struct request_queue *q,
62 gfp_t gfp_mask);
63void blk_exit_rl(struct request_list *rl);
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64void 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);
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67void blk_queue_bypass_start(struct request_queue *q);
68void blk_queue_bypass_end(struct request_queue *q);
9934c8c0 69void blk_dequeue_request(struct request *rq);
8324aa91 70void __blk_queue_free_tags(struct request_queue *q);
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71bool __blk_end_bidi_request(struct request *rq, int error,
72 unsigned int nr_bytes, unsigned int bidi_bytes);
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73void blk_freeze_queue(struct request_queue *q);
74
75static inline void blk_queue_enter_live(struct request_queue *q)
76{
77 /*
78 * Given that running in generic_make_request() context
79 * guarantees that a live reference against q_usage_counter has
80 * been established, further references under that same context
81 * need not check that the queue has been frozen (marked dead).
82 */
83 percpu_ref_get(&q->q_usage_counter);
84}
8324aa91 85
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86#ifdef CONFIG_BLK_DEV_INTEGRITY
87void blk_flush_integrity(void);
88#else
89static inline void blk_flush_integrity(void)
90{
91}
92#endif
8324aa91 93
287922eb 94void blk_timeout_work(struct work_struct *work);
0d2602ca 95unsigned long blk_rq_timeout(unsigned long timeout);
87ee7b11 96void blk_add_timer(struct request *req);
242f9dcb 97void blk_delete_timer(struct request *);
242f9dcb 98
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99
100bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
101 struct bio *bio);
102bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
103 struct bio *bio);
104bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
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105 unsigned int *request_count,
106 struct request **same_queue_rq);
0809e3ac 107unsigned int blk_plug_queued_count(struct request_queue *q);
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108
109void blk_account_io_start(struct request *req, bool new_io);
110void blk_account_io_completion(struct request *req, unsigned int bytes);
111void blk_account_io_done(struct request *req);
112
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113/*
114 * Internal atomic flags for request handling
115 */
116enum rq_atomic_flags {
117 REQ_ATOM_COMPLETE = 0,
320ae51f 118 REQ_ATOM_STARTED,
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119};
120
121/*
122 * EH timer and IO completion will both attempt to 'grab' the request, make
25985edc 123 * sure that only one of them succeeds
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124 */
125static inline int blk_mark_rq_complete(struct request *rq)
126{
127 return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
128}
129
130static inline void blk_clear_rq_complete(struct request *rq)
131{
132 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
133}
86db1e29 134
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135/*
136 * Internal elevator interface
137 */
360f92c2 138#define ELV_ON_HASH(rq) ((rq)->cmd_flags & REQ_HASHED)
158dbda0 139
ae1b1539 140void blk_insert_flush(struct request *rq);
dd831006 141
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142static inline struct request *__elv_next_request(struct request_queue *q)
143{
144 struct request *rq;
e97c293c 145 struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL);
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146
147 while (1) {
ae1b1539 148 if (!list_empty(&q->queue_head)) {
158dbda0 149 rq = list_entry_rq(q->queue_head.next);
ae1b1539 150 return rq;
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151 }
152
3ac0cc45 153 /*
154 * Flush request is running and flush request isn't queueable
155 * in the drive, we can hold the queue till flush request is
156 * finished. Even we don't do this, driver can't dispatch next
157 * requests and will requeue them. And this can improve
158 * throughput too. For example, we have request flush1, write1,
159 * flush 2. flush1 is dispatched, then queue is hold, write1
160 * isn't inserted to queue. After flush1 is finished, flush2
161 * will be dispatched. Since disk cache is already clean,
162 * flush2 will be finished very soon, so looks like flush2 is
163 * folded to flush1.
164 * Since the queue is hold, a flag is set to indicate the queue
165 * should be restarted later. Please see flush_end_io() for
166 * details.
167 */
7c94e1c1 168 if (fq->flush_pending_idx != fq->flush_running_idx &&
3ac0cc45 169 !queue_flush_queueable(q)) {
7c94e1c1 170 fq->flush_queue_delayed = 1;
3ac0cc45 171 return NULL;
172 }
556ee818 173 if (unlikely(blk_queue_bypass(q)) ||
22f746e2 174 !q->elevator->type->ops.elevator_dispatch_fn(q, 0))
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175 return NULL;
176 }
177}
178
179static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
180{
181 struct elevator_queue *e = q->elevator;
182
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183 if (e->type->ops.elevator_activate_req_fn)
184 e->type->ops.elevator_activate_req_fn(q, rq);
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185}
186
187static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
188{
189 struct elevator_queue *e = q->elevator;
190
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191 if (e->type->ops.elevator_deactivate_req_fn)
192 e->type->ops.elevator_deactivate_req_fn(q, rq);
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193}
194
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195#ifdef CONFIG_FAIL_IO_TIMEOUT
196int blk_should_fake_timeout(struct request_queue *);
197ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
198ssize_t part_timeout_store(struct device *, struct device_attribute *,
199 const char *, size_t);
200#else
201static inline int blk_should_fake_timeout(struct request_queue *q)
202{
203 return 0;
204}
205#endif
206
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207int ll_back_merge_fn(struct request_queue *q, struct request *req,
208 struct bio *bio);
209int ll_front_merge_fn(struct request_queue *q, struct request *req,
210 struct bio *bio);
211int attempt_back_merge(struct request_queue *q, struct request *rq);
212int attempt_front_merge(struct request_queue *q, struct request *rq);
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213int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
214 struct request *next);
d6d48196 215void blk_recalc_rq_segments(struct request *rq);
80a761fd 216void blk_rq_set_mixed_merge(struct request *rq);
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217bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
218int blk_try_merge(struct request *rq, struct bio *bio);
d6d48196 219
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220void blk_queue_congestion_threshold(struct request_queue *q);
221
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222int blk_dev_init(void);
223
f253b86b 224
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225/*
226 * Return the threshold (number of used requests) at which the queue is
227 * considered to be congested. It include a little hysteresis to keep the
228 * context switch rate down.
229 */
230static inline int queue_congestion_on_threshold(struct request_queue *q)
231{
232 return q->nr_congestion_on;
233}
234
235/*
236 * The threshold at which a queue is considered to be uncongested
237 */
238static inline int queue_congestion_off_threshold(struct request_queue *q)
239{
240 return q->nr_congestion_off;
241}
242
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243extern int blk_update_nr_requests(struct request_queue *, unsigned int);
244
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245/*
246 * Contribute to IO statistics IFF:
247 *
248 * a) it's attached to a gendisk, and
249 * b) the queue had IO stats enabled when this request was started, and
e2a60da7 250 * c) it's a file system request
c2553b58 251 */
26308eab 252static inline int blk_do_io_stat(struct request *rq)
fb8ec18c 253{
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254 return rq->rq_disk &&
255 (rq->cmd_flags & REQ_IO_STAT) &&
e2a60da7 256 (rq->cmd_type == REQ_TYPE_FS);
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257}
258
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259/*
260 * Internal io_context interface
261 */
262void get_io_context(struct io_context *ioc);
47fdd4ca 263struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
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264struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
265 gfp_t gfp_mask);
7e5a8794 266void ioc_clear_queue(struct request_queue *q);
f2dbd76a 267
24acfc34 268int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
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269
270/**
271 * create_io_context - try to create task->io_context
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272 * @gfp_mask: allocation mask
273 * @node: allocation node
274 *
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275 * If %current->io_context is %NULL, allocate a new io_context and install
276 * it. Returns the current %current->io_context which may be %NULL if
277 * allocation failed.
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278 *
279 * Note that this function can't be called with IRQ disabled because
24acfc34 280 * task_lock which protects %current->io_context is IRQ-unsafe.
f2dbd76a 281 */
24acfc34 282static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
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283{
284 WARN_ON_ONCE(irqs_disabled());
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285 if (unlikely(!current->io_context))
286 create_task_io_context(current, gfp_mask, node);
287 return current->io_context;
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288}
289
290/*
291 * Internal throttling interface
292 */
bc9fcbf9 293#ifdef CONFIG_BLK_DEV_THROTTLING
c9a929dd 294extern void blk_throtl_drain(struct request_queue *q);
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295extern int blk_throtl_init(struct request_queue *q);
296extern void blk_throtl_exit(struct request_queue *q);
297#else /* CONFIG_BLK_DEV_THROTTLING */
c9a929dd 298static inline void blk_throtl_drain(struct request_queue *q) { }
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299static inline int blk_throtl_init(struct request_queue *q) { return 0; }
300static inline void blk_throtl_exit(struct request_queue *q) { }
301#endif /* CONFIG_BLK_DEV_THROTTLING */
302
303#endif /* BLK_INTERNAL_H */