Loading...
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 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;
50}
51
52static inline void __blk_get_queue(struct request_queue *q)
53{
54 kobject_get(&q->kobj);
55}
56
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);
60
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);
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);
67int blk_rq_append_bio(struct request_queue *q, struct request *rq,
68 struct bio *bio);
69void blk_queue_bypass_start(struct request_queue *q);
70void blk_queue_bypass_end(struct request_queue *q);
71void blk_dequeue_request(struct request *rq);
72void __blk_queue_free_tags(struct request_queue *q);
73bool __blk_end_bidi_request(struct request *rq, int error,
74 unsigned int nr_bytes, unsigned int bidi_bytes);
75void 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}
87
88#ifdef CONFIG_BLK_DEV_INTEGRITY
89void blk_flush_integrity(void);
90#else
91static inline void blk_flush_integrity(void)
92{
93}
94#endif
95
96void blk_timeout_work(struct work_struct *work);
97unsigned long blk_rq_timeout(unsigned long timeout);
98void blk_add_timer(struct request *req);
99void blk_delete_timer(struct request *);
100
101
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,
107 unsigned int *request_count,
108 struct request **same_queue_rq);
109unsigned int blk_plug_queued_count(struct request_queue *q);
110
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
115/*
116 * Internal atomic flags for request handling
117 */
118enum rq_atomic_flags {
119 REQ_ATOM_COMPLETE = 0,
120 REQ_ATOM_STARTED,
121};
122
123/*
124 * EH timer and IO completion will both attempt to 'grab' the request, make
125 * sure that only one of them succeeds
126 */
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}
136
137/*
138 * Internal elevator interface
139 */
140#define ELV_ON_HASH(rq) ((rq)->cmd_flags & REQ_HASHED)
141
142void blk_insert_flush(struct request *rq);
143
144static inline struct request *__elv_next_request(struct request_queue *q)
145{
146 struct request *rq;
147 struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL);
148
149 while (1) {
150 if (!list_empty(&q->queue_head)) {
151 rq = list_entry_rq(q->queue_head.next);
152 return rq;
153 }
154
155 /*
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 */
170 if (fq->flush_pending_idx != fq->flush_running_idx &&
171 !queue_flush_queueable(q)) {
172 fq->flush_queue_delayed = 1;
173 return NULL;
174 }
175 if (unlikely(blk_queue_bypass(q)) ||
176 !q->elevator->type->ops.elevator_dispatch_fn(q, 0))
177 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
185 if (e->type->ops.elevator_activate_req_fn)
186 e->type->ops.elevator_activate_req_fn(q, rq);
187}
188
189static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
190{
191 struct elevator_queue *e = q->elevator;
192
193 if (e->type->ops.elevator_deactivate_req_fn)
194 e->type->ops.elevator_deactivate_req_fn(q, rq);
195}
196
197#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
209int 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);
215int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
216 struct request *next);
217void blk_recalc_rq_segments(struct request *rq);
218void blk_rq_set_mixed_merge(struct request *rq);
219bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
220int blk_try_merge(struct request *rq, struct bio *bio);
221
222void blk_queue_congestion_threshold(struct request_queue *q);
223
224int blk_dev_init(void);
225
226
227/*
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
245extern int blk_update_nr_requests(struct request_queue *, unsigned int);
246
247/*
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
252 * c) it's a file system request
253 */
254static inline int blk_do_io_stat(struct request *rq)
255{
256 return rq->rq_disk &&
257 (rq->cmd_flags & REQ_IO_STAT) &&
258 (rq->cmd_type == REQ_TYPE_FS);
259}
260
261/*
262 * Internal io_context interface
263 */
264void get_io_context(struct io_context *ioc);
265struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
266struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
267 gfp_t gfp_mask);
268void ioc_clear_queue(struct request_queue *q);
269
270int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
271
272/**
273 * create_io_context - try to create task->io_context
274 * @gfp_mask: allocation mask
275 * @node: allocation node
276 *
277 * 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.
280 *
281 * Note that this function can't be called with IRQ disabled because
282 * task_lock which protects %current->io_context is IRQ-unsafe.
283 */
284static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
285{
286 WARN_ON_ONCE(irqs_disabled());
287 if (unlikely(!current->io_context))
288 create_task_io_context(current, gfp_mask, node);
289 return current->io_context;
290}
291
292/*
293 * Internal throttling interface
294 */
295#ifdef CONFIG_BLK_DEV_THROTTLING
296extern void blk_throtl_drain(struct request_queue *q);
297extern int blk_throtl_init(struct request_queue *q);
298extern void blk_throtl_exit(struct request_queue *q);
299#else /* CONFIG_BLK_DEV_THROTTLING */
300static inline void blk_throtl_drain(struct request_queue *q) { }
301static 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 */
1#ifndef BLK_INTERNAL_H
2#define BLK_INTERNAL_H
3
4#include <linux/idr.h>
5
6/* 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
12extern struct kmem_cache *blk_requestq_cachep;
13extern struct kobj_type blk_queue_ktype;
14extern struct ida blk_queue_ida;
15
16static inline void __blk_get_queue(struct request_queue *q)
17{
18 kobject_get(&q->kobj);
19}
20
21void init_request_from_bio(struct request *req, struct bio *bio);
22void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
23 struct bio *bio);
24int blk_rq_append_bio(struct request_queue *q, struct request *rq,
25 struct bio *bio);
26void blk_queue_bypass_start(struct request_queue *q);
27void blk_queue_bypass_end(struct request_queue *q);
28void blk_dequeue_request(struct request *rq);
29void __blk_queue_free_tags(struct request_queue *q);
30bool __blk_end_bidi_request(struct request *rq, int error,
31 unsigned int nr_bytes, unsigned int bidi_bytes);
32
33void blk_rq_timed_out_timer(unsigned long data);
34void blk_delete_timer(struct request *);
35void blk_add_timer(struct request *);
36void __generic_unplug_device(struct request_queue *);
37
38/*
39 * Internal atomic flags for request handling
40 */
41enum rq_atomic_flags {
42 REQ_ATOM_COMPLETE = 0,
43};
44
45/*
46 * EH timer and IO completion will both attempt to 'grab' the request, make
47 * sure that only one of them succeeds
48 */
49static inline int blk_mark_rq_complete(struct request *rq)
50{
51 return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
52}
53
54static inline void blk_clear_rq_complete(struct request *rq)
55{
56 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
57}
58
59/*
60 * Internal elevator interface
61 */
62#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash))
63
64void blk_insert_flush(struct request *rq);
65void blk_abort_flushes(struct request_queue *q);
66
67static inline struct request *__elv_next_request(struct request_queue *q)
68{
69 struct request *rq;
70
71 while (1) {
72 if (!list_empty(&q->queue_head)) {
73 rq = list_entry_rq(q->queue_head.next);
74 return rq;
75 }
76
77 /*
78 * Flush request is running and flush request isn't queueable
79 * in the drive, we can hold the queue till flush request is
80 * finished. Even we don't do this, driver can't dispatch next
81 * requests and will requeue them. And this can improve
82 * throughput too. For example, we have request flush1, write1,
83 * flush 2. flush1 is dispatched, then queue is hold, write1
84 * isn't inserted to queue. After flush1 is finished, flush2
85 * will be dispatched. Since disk cache is already clean,
86 * flush2 will be finished very soon, so looks like flush2 is
87 * folded to flush1.
88 * Since the queue is hold, a flag is set to indicate the queue
89 * should be restarted later. Please see flush_end_io() for
90 * details.
91 */
92 if (q->flush_pending_idx != q->flush_running_idx &&
93 !queue_flush_queueable(q)) {
94 q->flush_queue_delayed = 1;
95 return NULL;
96 }
97 if (unlikely(blk_queue_dead(q)) ||
98 !q->elevator->type->ops.elevator_dispatch_fn(q, 0))
99 return NULL;
100 }
101}
102
103static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
104{
105 struct elevator_queue *e = q->elevator;
106
107 if (e->type->ops.elevator_activate_req_fn)
108 e->type->ops.elevator_activate_req_fn(q, rq);
109}
110
111static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
112{
113 struct elevator_queue *e = q->elevator;
114
115 if (e->type->ops.elevator_deactivate_req_fn)
116 e->type->ops.elevator_deactivate_req_fn(q, rq);
117}
118
119#ifdef CONFIG_FAIL_IO_TIMEOUT
120int blk_should_fake_timeout(struct request_queue *);
121ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
122ssize_t part_timeout_store(struct device *, struct device_attribute *,
123 const char *, size_t);
124#else
125static inline int blk_should_fake_timeout(struct request_queue *q)
126{
127 return 0;
128}
129#endif
130
131int ll_back_merge_fn(struct request_queue *q, struct request *req,
132 struct bio *bio);
133int ll_front_merge_fn(struct request_queue *q, struct request *req,
134 struct bio *bio);
135int attempt_back_merge(struct request_queue *q, struct request *rq);
136int attempt_front_merge(struct request_queue *q, struct request *rq);
137int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
138 struct request *next);
139void blk_recalc_rq_segments(struct request *rq);
140void blk_rq_set_mixed_merge(struct request *rq);
141bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
142int blk_try_merge(struct request *rq, struct bio *bio);
143
144void blk_queue_congestion_threshold(struct request_queue *q);
145
146int blk_dev_init(void);
147
148
149/*
150 * Return the threshold (number of used requests) at which the queue is
151 * considered to be congested. It include a little hysteresis to keep the
152 * context switch rate down.
153 */
154static inline int queue_congestion_on_threshold(struct request_queue *q)
155{
156 return q->nr_congestion_on;
157}
158
159/*
160 * The threshold at which a queue is considered to be uncongested
161 */
162static inline int queue_congestion_off_threshold(struct request_queue *q)
163{
164 return q->nr_congestion_off;
165}
166
167/*
168 * Contribute to IO statistics IFF:
169 *
170 * a) it's attached to a gendisk, and
171 * b) the queue had IO stats enabled when this request was started, and
172 * c) it's a file system request or a discard request
173 */
174static inline int blk_do_io_stat(struct request *rq)
175{
176 return rq->rq_disk &&
177 (rq->cmd_flags & REQ_IO_STAT) &&
178 (rq->cmd_type == REQ_TYPE_FS ||
179 (rq->cmd_flags & REQ_DISCARD));
180}
181
182/*
183 * Internal io_context interface
184 */
185void get_io_context(struct io_context *ioc);
186struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
187struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
188 gfp_t gfp_mask);
189void ioc_clear_queue(struct request_queue *q);
190
191int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
192
193/**
194 * create_io_context - try to create task->io_context
195 * @gfp_mask: allocation mask
196 * @node: allocation node
197 *
198 * If %current->io_context is %NULL, allocate a new io_context and install
199 * it. Returns the current %current->io_context which may be %NULL if
200 * allocation failed.
201 *
202 * Note that this function can't be called with IRQ disabled because
203 * task_lock which protects %current->io_context is IRQ-unsafe.
204 */
205static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
206{
207 WARN_ON_ONCE(irqs_disabled());
208 if (unlikely(!current->io_context))
209 create_task_io_context(current, gfp_mask, node);
210 return current->io_context;
211}
212
213/*
214 * Internal throttling interface
215 */
216#ifdef CONFIG_BLK_DEV_THROTTLING
217extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio);
218extern void blk_throtl_drain(struct request_queue *q);
219extern int blk_throtl_init(struct request_queue *q);
220extern void blk_throtl_exit(struct request_queue *q);
221#else /* CONFIG_BLK_DEV_THROTTLING */
222static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio)
223{
224 return false;
225}
226static inline void blk_throtl_drain(struct request_queue *q) { }
227static inline int blk_throtl_init(struct request_queue *q) { return 0; }
228static inline void blk_throtl_exit(struct request_queue *q) { }
229#endif /* CONFIG_BLK_DEV_THROTTLING */
230
231#endif /* BLK_INTERNAL_H */