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1 | #ifndef BLK_INTERNAL_H |
2 | #define BLK_INTERNAL_H |
3 | |
4 | /* Amount of time in which a process may batch requests */ |
5 | #define BLK_BATCH_TIME (HZ/50UL) |
6 | |
7 | /* Number of requests a "batching" process may submit */ |
8 | #define BLK_BATCH_REQ 32 |
9 | |
10 | extern struct kmem_cache *blk_requestq_cachep; |
11 | extern struct kobj_type blk_queue_ktype; |
12 | |
13 | void init_request_from_bio(struct request *req, struct bio *bio); |
14 | void blk_rq_bio_prep(struct request_queue *q, struct request *rq, |
15 | struct bio *bio); |
16 | int blk_rq_append_bio(struct request_queue *q, struct request *rq, |
17 | struct bio *bio); |
18 | void blk_dequeue_request(struct request *rq); |
19 | void __blk_queue_free_tags(struct request_queue *q); |
20 | |
21 | void blk_rq_timed_out_timer(unsigned long data); |
22 | void blk_delete_timer(struct request *); |
23 | void blk_add_timer(struct request *); |
24 | void __generic_unplug_device(struct request_queue *); |
25 | |
26 | /* |
27 | * Internal atomic flags for request handling |
28 | */ |
29 | enum rq_atomic_flags { |
30 | REQ_ATOM_COMPLETE = 0, |
31 | }; |
32 | |
33 | /* |
34 | * EH timer and IO completion will both attempt to 'grab' the request, make |
35 | * sure that only one of them succeeds |
36 | */ |
37 | static inline int blk_mark_rq_complete(struct request *rq) |
38 | { |
39 | return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); |
40 | } |
41 | |
42 | static inline void blk_clear_rq_complete(struct request *rq) |
43 | { |
44 | clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags); |
45 | } |
46 | |
47 | /* |
48 | * Internal elevator interface |
49 | */ |
50 | #define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash)) |
51 | |
52 | void blk_insert_flush(struct request *rq); |
53 | void blk_abort_flushes(struct request_queue *q); |
54 | |
55 | static inline struct request *__elv_next_request(struct request_queue *q) |
56 | { |
57 | struct request *rq; |
58 | |
59 | while (1) { |
60 | if (!list_empty(&q->queue_head)) { |
61 | rq = list_entry_rq(q->queue_head.next); |
62 | return rq; |
63 | } |
64 | |
65 | /* |
66 | * Flush request is running and flush request isn't queueable |
67 | * in the drive, we can hold the queue till flush request is |
68 | * finished. Even we don't do this, driver can't dispatch next |
69 | * requests and will requeue them. And this can improve |
70 | * throughput too. For example, we have request flush1, write1, |
71 | * flush 2. flush1 is dispatched, then queue is hold, write1 |
72 | * isn't inserted to queue. After flush1 is finished, flush2 |
73 | * will be dispatched. Since disk cache is already clean, |
74 | * flush2 will be finished very soon, so looks like flush2 is |
75 | * folded to flush1. |
76 | * Since the queue is hold, a flag is set to indicate the queue |
77 | * should be restarted later. Please see flush_end_io() for |
78 | * details. |
79 | */ |
80 | if (q->flush_pending_idx != q->flush_running_idx && |
81 | !queue_flush_queueable(q)) { |
82 | q->flush_queue_delayed = 1; |
83 | return NULL; |
84 | } |
85 | if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags) || |
86 | !q->elevator->ops->elevator_dispatch_fn(q, 0)) |
87 | return NULL; |
88 | } |
89 | } |
90 | |
91 | static inline void elv_activate_rq(struct request_queue *q, struct request *rq) |
92 | { |
93 | struct elevator_queue *e = q->elevator; |
94 | |
95 | if (e->ops->elevator_activate_req_fn) |
96 | e->ops->elevator_activate_req_fn(q, rq); |
97 | } |
98 | |
99 | static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq) |
100 | { |
101 | struct elevator_queue *e = q->elevator; |
102 | |
103 | if (e->ops->elevator_deactivate_req_fn) |
104 | e->ops->elevator_deactivate_req_fn(q, rq); |
105 | } |
106 | |
107 | #ifdef CONFIG_FAIL_IO_TIMEOUT |
108 | int blk_should_fake_timeout(struct request_queue *); |
109 | ssize_t part_timeout_show(struct device *, struct device_attribute *, char *); |
110 | ssize_t part_timeout_store(struct device *, struct device_attribute *, |
111 | const char *, size_t); |
112 | #else |
113 | static inline int blk_should_fake_timeout(struct request_queue *q) |
114 | { |
115 | return 0; |
116 | } |
117 | #endif |
118 | |
119 | struct io_context *current_io_context(gfp_t gfp_flags, int node); |
120 | |
121 | int ll_back_merge_fn(struct request_queue *q, struct request *req, |
122 | struct bio *bio); |
123 | int ll_front_merge_fn(struct request_queue *q, struct request *req, |
124 | struct bio *bio); |
125 | int attempt_back_merge(struct request_queue *q, struct request *rq); |
126 | int attempt_front_merge(struct request_queue *q, struct request *rq); |
127 | int blk_attempt_req_merge(struct request_queue *q, struct request *rq, |
128 | struct request *next); |
129 | void blk_recalc_rq_segments(struct request *rq); |
130 | void blk_rq_set_mixed_merge(struct request *rq); |
131 | |
132 | void blk_queue_congestion_threshold(struct request_queue *q); |
133 | |
134 | int blk_dev_init(void); |
135 | |
136 | void elv_quiesce_start(struct request_queue *q); |
137 | void elv_quiesce_end(struct request_queue *q); |
138 | |
139 | |
140 | /* |
141 | * Return the threshold (number of used requests) at which the queue is |
142 | * considered to be congested. It include a little hysteresis to keep the |
143 | * context switch rate down. |
144 | */ |
145 | static inline int queue_congestion_on_threshold(struct request_queue *q) |
146 | { |
147 | return q->nr_congestion_on; |
148 | } |
149 | |
150 | /* |
151 | * The threshold at which a queue is considered to be uncongested |
152 | */ |
153 | static inline int queue_congestion_off_threshold(struct request_queue *q) |
154 | { |
155 | return q->nr_congestion_off; |
156 | } |
157 | |
158 | static inline int blk_cpu_to_group(int cpu) |
159 | { |
160 | int group = NR_CPUS; |
161 | #ifdef CONFIG_SCHED_MC |
162 | const struct cpumask *mask = cpu_coregroup_mask(cpu); |
163 | group = cpumask_first(mask); |
164 | #elif defined(CONFIG_SCHED_SMT) |
165 | group = cpumask_first(topology_thread_cpumask(cpu)); |
166 | #else |
167 | return cpu; |
168 | #endif |
169 | if (likely(group < NR_CPUS)) |
170 | return group; |
171 | return cpu; |
172 | } |
173 | |
174 | /* |
175 | * Contribute to IO statistics IFF: |
176 | * |
177 | * a) it's attached to a gendisk, and |
178 | * b) the queue had IO stats enabled when this request was started, and |
179 | * c) it's a file system request or a discard request |
180 | */ |
181 | static inline int blk_do_io_stat(struct request *rq) |
182 | { |
183 | return rq->rq_disk && |
184 | (rq->cmd_flags & REQ_IO_STAT) && |
185 | (rq->cmd_type == REQ_TYPE_FS || |
186 | (rq->cmd_flags & REQ_DISCARD)); |
187 | } |
188 | |
189 | #endif |
190 |
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