Branch data Line data Source code
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 : :
12 : : extern struct kmem_cache *blk_requestq_cachep;
13 : : extern struct kmem_cache *request_cachep;
14 : : extern struct kobj_type blk_queue_ktype;
15 : : extern struct ida blk_queue_ida;
16 : :
17 : : static inline void __blk_get_queue(struct request_queue *q)
18 : : {
19 : 0 : kobject_get(&q->kobj);
20 : : }
21 : :
22 : : int blk_init_rl(struct request_list *rl, struct request_queue *q,
23 : : gfp_t gfp_mask);
24 : : void blk_exit_rl(struct request_list *rl);
25 : : void init_request_from_bio(struct request *req, struct bio *bio);
26 : : void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
27 : : struct bio *bio);
28 : : int blk_rq_append_bio(struct request_queue *q, struct request *rq,
29 : : struct bio *bio);
30 : : void blk_queue_bypass_start(struct request_queue *q);
31 : : void blk_queue_bypass_end(struct request_queue *q);
32 : : void blk_dequeue_request(struct request *rq);
33 : : void __blk_queue_free_tags(struct request_queue *q);
34 : : bool __blk_end_bidi_request(struct request *rq, int error,
35 : : unsigned int nr_bytes, unsigned int bidi_bytes);
36 : :
37 : : void blk_rq_timed_out_timer(unsigned long data);
38 : : void blk_rq_check_expired(struct request *rq, unsigned long *next_timeout,
39 : : unsigned int *next_set);
40 : : void __blk_add_timer(struct request *req, struct list_head *timeout_list);
41 : : void blk_delete_timer(struct request *);
42 : : void blk_add_timer(struct request *);
43 : :
44 : :
45 : : bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
46 : : struct bio *bio);
47 : : bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
48 : : struct bio *bio);
49 : : bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
50 : : unsigned int *request_count);
51 : :
52 : : void blk_account_io_start(struct request *req, bool new_io);
53 : : void blk_account_io_completion(struct request *req, unsigned int bytes);
54 : : void blk_account_io_done(struct request *req);
55 : :
56 : : /*
57 : : * Internal atomic flags for request handling
58 : : */
59 : : enum rq_atomic_flags {
60 : : REQ_ATOM_COMPLETE = 0,
61 : : REQ_ATOM_STARTED,
62 : : };
63 : :
64 : : /*
65 : : * EH timer and IO completion will both attempt to 'grab' the request, make
66 : : * sure that only one of them succeeds
67 : : */
68 : : static inline int blk_mark_rq_complete(struct request *rq)
69 : : {
70 : 401979 : return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
71 : : }
72 : :
73 : : static inline void blk_clear_rq_complete(struct request *rq)
74 : : {
75 : 0 : clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
76 : : }
77 : :
78 : : /*
79 : : * Internal elevator interface
80 : : */
81 : : #define ELV_ON_HASH(rq) hash_hashed(&(rq)->hash)
82 : :
83 : : void blk_insert_flush(struct request *rq);
84 : : void blk_abort_flushes(struct request_queue *q);
85 : :
86 : : static inline struct request *__elv_next_request(struct request_queue *q)
87 : : {
88 : : struct request *rq;
89 : :
90 : : while (1) {
91 [ + + ]: 1730123 : if (!list_empty(&q->queue_head)) {
92 : : rq = list_entry_rq(q->queue_head.next);
93 : : return rq;
94 : : }
95 : :
96 : : /*
97 : : * Flush request is running and flush request isn't queueable
98 : : * in the drive, we can hold the queue till flush request is
99 : : * finished. Even we don't do this, driver can't dispatch next
100 : : * requests and will requeue them. And this can improve
101 : : * throughput too. For example, we have request flush1, write1,
102 : : * flush 2. flush1 is dispatched, then queue is hold, write1
103 : : * isn't inserted to queue. After flush1 is finished, flush2
104 : : * will be dispatched. Since disk cache is already clean,
105 : : * flush2 will be finished very soon, so looks like flush2 is
106 : : * folded to flush1.
107 : : * Since the queue is hold, a flag is set to indicate the queue
108 : : * should be restarted later. Please see flush_end_io() for
109 : : * details.
110 : : */
111 [ - + ][ # # ]: 1152332 : if (q->flush_pending_idx != q->flush_running_idx &&
112 : : !queue_flush_queueable(q)) {
113 : 0 : q->flush_queue_delayed = 1;
114 : : return NULL;
115 : : }
116 [ + - + + ]: 2304664 : if (unlikely(blk_queue_bypass(q)) ||
117 : 1152332 : !q->elevator->type->ops.elevator_dispatch_fn(q, 0))
118 : : return NULL;
119 : : }
120 : : }
121 : :
122 : : static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
123 : : {
124 : 387103 : struct elevator_queue *e = q->elevator;
125 : :
126 [ + - ]: 387103 : if (e->type->ops.elevator_activate_req_fn)
127 : 387103 : e->type->ops.elevator_activate_req_fn(q, rq);
128 : : }
129 : :
130 : : static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
131 : : {
132 : 0 : struct elevator_queue *e = q->elevator;
133 : :
134 [ # # ]: 0 : if (e->type->ops.elevator_deactivate_req_fn)
135 : 0 : e->type->ops.elevator_deactivate_req_fn(q, rq);
136 : : }
137 : :
138 : : #ifdef CONFIG_FAIL_IO_TIMEOUT
139 : : int blk_should_fake_timeout(struct request_queue *);
140 : : ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
141 : : ssize_t part_timeout_store(struct device *, struct device_attribute *,
142 : : const char *, size_t);
143 : : #else
144 : : static inline int blk_should_fake_timeout(struct request_queue *q)
145 : : {
146 : : return 0;
147 : : }
148 : : #endif
149 : :
150 : : int ll_back_merge_fn(struct request_queue *q, struct request *req,
151 : : struct bio *bio);
152 : : int ll_front_merge_fn(struct request_queue *q, struct request *req,
153 : : struct bio *bio);
154 : : int attempt_back_merge(struct request_queue *q, struct request *rq);
155 : : int attempt_front_merge(struct request_queue *q, struct request *rq);
156 : : int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
157 : : struct request *next);
158 : : void blk_recalc_rq_segments(struct request *rq);
159 : : void blk_rq_set_mixed_merge(struct request *rq);
160 : : bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
161 : : int blk_try_merge(struct request *rq, struct bio *bio);
162 : :
163 : : void blk_queue_congestion_threshold(struct request_queue *q);
164 : :
165 : : void __blk_run_queue_uncond(struct request_queue *q);
166 : :
167 : : int blk_dev_init(void);
168 : :
169 : :
170 : : /*
171 : : * Return the threshold (number of used requests) at which the queue is
172 : : * considered to be congested. It include a little hysteresis to keep the
173 : : * context switch rate down.
174 : : */
175 : : static inline int queue_congestion_on_threshold(struct request_queue *q)
176 : : {
177 : 403578 : return q->nr_congestion_on;
178 : : }
179 : :
180 : : /*
181 : : * The threshold at which a queue is considered to be uncongested
182 : : */
183 : : static inline int queue_congestion_off_threshold(struct request_queue *q)
184 : : {
185 : 402828 : return q->nr_congestion_off;
186 : : }
187 : :
188 : : /*
189 : : * Contribute to IO statistics IFF:
190 : : *
191 : : * a) it's attached to a gendisk, and
192 : : * b) the queue had IO stats enabled when this request was started, and
193 : : * c) it's a file system request
194 : : */
195 : : static inline int blk_do_io_stat(struct request *rq)
196 : : {
197 [ + ][ + - ]: 1229940 : return rq->rq_disk &&
[ + - ][ - ]
198 [ + ][ + + ]: 2474754 : (rq->cmd_flags & REQ_IO_STAT) &&
[ + + ][ - + ]
[ + - ][ - + ]
[ - ]
199 : 1229954 : (rq->cmd_type == REQ_TYPE_FS);
200 : : }
201 : :
202 : : /*
203 : : * Internal io_context interface
204 : : */
205 : : void get_io_context(struct io_context *ioc);
206 : : struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
207 : : struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
208 : : gfp_t gfp_mask);
209 : : void ioc_clear_queue(struct request_queue *q);
210 : :
211 : : int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
212 : :
213 : : /**
214 : : * create_io_context - try to create task->io_context
215 : : * @gfp_mask: allocation mask
216 : : * @node: allocation node
217 : : *
218 : : * If %current->io_context is %NULL, allocate a new io_context and install
219 : : * it. Returns the current %current->io_context which may be %NULL if
220 : : * allocation failed.
221 : : *
222 : : * Note that this function can't be called with IRQ disabled because
223 : : * task_lock which protects %current->io_context is IRQ-unsafe.
224 : : */
225 : : static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
226 : : {
227 [ - + ][ # # ]: 476044 : WARN_ON_ONCE(irqs_disabled());
[ - + ][ - + ]
[ # # ][ # # ]
228 [ + + ][ + + ]: 476051 : if (unlikely(!current->io_context))
229 : 5305 : create_task_io_context(current, gfp_mask, node);
230 : : return current->io_context;
231 : : }
232 : :
233 : : /*
234 : : * Internal throttling interface
235 : : */
236 : : #ifdef CONFIG_BLK_DEV_THROTTLING
237 : : extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio);
238 : : extern void blk_throtl_drain(struct request_queue *q);
239 : : extern int blk_throtl_init(struct request_queue *q);
240 : : extern void blk_throtl_exit(struct request_queue *q);
241 : : #else /* CONFIG_BLK_DEV_THROTTLING */
242 : : static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio)
243 : : {
244 : : return false;
245 : : }
246 : : static inline void blk_throtl_drain(struct request_queue *q) { }
247 : : static inline int blk_throtl_init(struct request_queue *q) { return 0; }
248 : : static inline void blk_throtl_exit(struct request_queue *q) { }
249 : : #endif /* CONFIG_BLK_DEV_THROTTLING */
250 : :
251 : : #endif /* BLK_INTERNAL_H */
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