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1#ifndef BLK_INTERNAL_H
2#define BLK_INTERNAL_H
3
4#include <linux/idr.h>
5#include <linux/blk-mq.h>
6#include "blk-mq.h"
7
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
14/* Max future timer expiry for timeouts */
15#define BLK_MAX_TIMEOUT (5 * HZ)
16
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;
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;
31 spinlock_t mq_flush_lock;
32};
33
34extern struct kmem_cache *blk_requestq_cachep;
35extern struct kmem_cache *request_cachep;
36extern struct kobj_type blk_queue_ktype;
37extern struct ida blk_queue_ida;
38
39static inline struct blk_flush_queue *blk_get_flush_queue(
40 struct request_queue *q, struct blk_mq_ctx *ctx)
41{
42 if (q->mq_ops)
43 return blk_mq_map_queue(q, ctx->cpu)->fq;
44 return q->fq;
45}
46
47static inline void __blk_get_queue(struct request_queue *q)
48{
49 kobject_get(&q->kobj);
50}
51
52struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
53 int node, int cmd_size);
54void blk_free_flush_queue(struct blk_flush_queue *q);
55
56int blk_init_rl(struct request_list *rl, struct request_queue *q,
57 gfp_t gfp_mask);
58void blk_exit_rl(struct request_list *rl);
59void init_request_from_bio(struct request *req, struct bio *bio);
60void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
61 struct bio *bio);
62void blk_queue_bypass_start(struct request_queue *q);
63void blk_queue_bypass_end(struct request_queue *q);
64void blk_dequeue_request(struct request *rq);
65void __blk_queue_free_tags(struct request_queue *q);
66bool __blk_end_bidi_request(struct request *rq, int error,
67 unsigned int nr_bytes, unsigned int bidi_bytes);
68void blk_freeze_queue(struct request_queue *q);
69
70static inline void blk_queue_enter_live(struct request_queue *q)
71{
72 /*
73 * Given that running in generic_make_request() context
74 * guarantees that a live reference against q_usage_counter has
75 * been established, further references under that same context
76 * need not check that the queue has been frozen (marked dead).
77 */
78 percpu_ref_get(&q->q_usage_counter);
79}
80
81#ifdef CONFIG_BLK_DEV_INTEGRITY
82void blk_flush_integrity(void);
83#else
84static inline void blk_flush_integrity(void)
85{
86}
87#endif
88
89void blk_timeout_work(struct work_struct *work);
90unsigned long blk_rq_timeout(unsigned long timeout);
91void blk_add_timer(struct request *req);
92void blk_delete_timer(struct request *);
93
94
95bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
96 struct bio *bio);
97bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
98 struct bio *bio);
99bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
100 unsigned int *request_count,
101 struct request **same_queue_rq);
102unsigned int blk_plug_queued_count(struct request_queue *q);
103
104void blk_account_io_start(struct request *req, bool new_io);
105void blk_account_io_completion(struct request *req, unsigned int bytes);
106void blk_account_io_done(struct request *req);
107
108/*
109 * Internal atomic flags for request handling
110 */
111enum rq_atomic_flags {
112 REQ_ATOM_COMPLETE = 0,
113 REQ_ATOM_STARTED,
114};
115
116/*
117 * EH timer and IO completion will both attempt to 'grab' the request, make
118 * sure that only one of them succeeds
119 */
120static inline int blk_mark_rq_complete(struct request *rq)
121{
122 return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
123}
124
125static inline void blk_clear_rq_complete(struct request *rq)
126{
127 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
128}
129
130/*
131 * Internal elevator interface
132 */
133#define ELV_ON_HASH(rq) ((rq)->cmd_flags & REQ_HASHED)
134
135void blk_insert_flush(struct request *rq);
136
137static inline struct request *__elv_next_request(struct request_queue *q)
138{
139 struct request *rq;
140 struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL);
141
142 while (1) {
143 if (!list_empty(&q->queue_head)) {
144 rq = list_entry_rq(q->queue_head.next);
145 return rq;
146 }
147
148 /*
149 * Flush request is running and flush request isn't queueable
150 * in the drive, we can hold the queue till flush request is
151 * finished. Even we don't do this, driver can't dispatch next
152 * requests and will requeue them. And this can improve
153 * throughput too. For example, we have request flush1, write1,
154 * flush 2. flush1 is dispatched, then queue is hold, write1
155 * isn't inserted to queue. After flush1 is finished, flush2
156 * will be dispatched. Since disk cache is already clean,
157 * flush2 will be finished very soon, so looks like flush2 is
158 * folded to flush1.
159 * Since the queue is hold, a flag is set to indicate the queue
160 * should be restarted later. Please see flush_end_io() for
161 * details.
162 */
163 if (fq->flush_pending_idx != fq->flush_running_idx &&
164 !queue_flush_queueable(q)) {
165 fq->flush_queue_delayed = 1;
166 return NULL;
167 }
168 if (unlikely(blk_queue_bypass(q)) ||
169 !q->elevator->type->ops.elevator_dispatch_fn(q, 0))
170 return NULL;
171 }
172}
173
174static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
175{
176 struct elevator_queue *e = q->elevator;
177
178 if (e->type->ops.elevator_activate_req_fn)
179 e->type->ops.elevator_activate_req_fn(q, rq);
180}
181
182static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
183{
184 struct elevator_queue *e = q->elevator;
185
186 if (e->type->ops.elevator_deactivate_req_fn)
187 e->type->ops.elevator_deactivate_req_fn(q, rq);
188}
189
190#ifdef CONFIG_FAIL_IO_TIMEOUT
191int blk_should_fake_timeout(struct request_queue *);
192ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
193ssize_t part_timeout_store(struct device *, struct device_attribute *,
194 const char *, size_t);
195#else
196static inline int blk_should_fake_timeout(struct request_queue *q)
197{
198 return 0;
199}
200#endif
201
202int ll_back_merge_fn(struct request_queue *q, struct request *req,
203 struct bio *bio);
204int ll_front_merge_fn(struct request_queue *q, struct request *req,
205 struct bio *bio);
206int attempt_back_merge(struct request_queue *q, struct request *rq);
207int attempt_front_merge(struct request_queue *q, struct request *rq);
208int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
209 struct request *next);
210void blk_recalc_rq_segments(struct request *rq);
211void blk_rq_set_mixed_merge(struct request *rq);
212bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
213int blk_try_merge(struct request *rq, struct bio *bio);
214
215void blk_queue_congestion_threshold(struct request_queue *q);
216
217int blk_dev_init(void);
218
219
220/*
221 * Return the threshold (number of used requests) at which the queue is
222 * considered to be congested. It include a little hysteresis to keep the
223 * context switch rate down.
224 */
225static inline int queue_congestion_on_threshold(struct request_queue *q)
226{
227 return q->nr_congestion_on;
228}
229
230/*
231 * The threshold at which a queue is considered to be uncongested
232 */
233static inline int queue_congestion_off_threshold(struct request_queue *q)
234{
235 return q->nr_congestion_off;
236}
237
238extern int blk_update_nr_requests(struct request_queue *, unsigned int);
239
240/*
241 * Contribute to IO statistics IFF:
242 *
243 * a) it's attached to a gendisk, and
244 * b) the queue had IO stats enabled when this request was started, and
245 * c) it's a file system request
246 */
247static inline int blk_do_io_stat(struct request *rq)
248{
249 return rq->rq_disk &&
250 (rq->cmd_flags & REQ_IO_STAT) &&
251 (rq->cmd_type == REQ_TYPE_FS);
252}
253
254/*
255 * Internal io_context interface
256 */
257void get_io_context(struct io_context *ioc);
258struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
259struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
260 gfp_t gfp_mask);
261void ioc_clear_queue(struct request_queue *q);
262
263int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
264
265/**
266 * create_io_context - try to create task->io_context
267 * @gfp_mask: allocation mask
268 * @node: allocation node
269 *
270 * If %current->io_context is %NULL, allocate a new io_context and install
271 * it. Returns the current %current->io_context which may be %NULL if
272 * allocation failed.
273 *
274 * Note that this function can't be called with IRQ disabled because
275 * task_lock which protects %current->io_context is IRQ-unsafe.
276 */
277static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
278{
279 WARN_ON_ONCE(irqs_disabled());
280 if (unlikely(!current->io_context))
281 create_task_io_context(current, gfp_mask, node);
282 return current->io_context;
283}
284
285/*
286 * Internal throttling interface
287 */
288#ifdef CONFIG_BLK_DEV_THROTTLING
289extern void blk_throtl_drain(struct request_queue *q);
290extern int blk_throtl_init(struct request_queue *q);
291extern void blk_throtl_exit(struct request_queue *q);
292#else /* CONFIG_BLK_DEV_THROTTLING */
293static inline void blk_throtl_drain(struct request_queue *q) { }
294static inline int blk_throtl_init(struct request_queue *q) { return 0; }
295static inline void blk_throtl_exit(struct request_queue *q) { }
296#endif /* CONFIG_BLK_DEV_THROTTLING */
297
298#endif /* BLK_INTERNAL_H */
299
generated by cgit at 2024-05-18 14:50:39 (GMT)