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[PATCH] rbtree: fixed reversed RB_EMPTY_NODE and rb_next/prev
[linux-block.git] / include / linux / elevator.h
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CommitLineData
1#ifndef _LINUX_ELEVATOR_H
2#define _LINUX_ELEVATOR_H
3
4typedef int (elevator_merge_fn) (request_queue_t *, struct request **,
5 struct bio *);
6
7typedef void (elevator_merge_req_fn) (request_queue_t *, struct request *, struct request *);
8
9typedef void (elevator_merged_fn) (request_queue_t *, struct request *);
10
11typedef int (elevator_dispatch_fn) (request_queue_t *, int);
12
13typedef void (elevator_add_req_fn) (request_queue_t *, struct request *);
14typedef int (elevator_queue_empty_fn) (request_queue_t *);
15typedef struct request *(elevator_request_list_fn) (request_queue_t *, struct request *);
16typedef void (elevator_completed_req_fn) (request_queue_t *, struct request *);
17typedef int (elevator_may_queue_fn) (request_queue_t *, int, struct bio *);
18
19typedef int (elevator_set_req_fn) (request_queue_t *, struct request *, struct bio *, gfp_t);
20typedef void (elevator_put_req_fn) (request_queue_t *, struct request *);
21typedef void (elevator_activate_req_fn) (request_queue_t *, struct request *);
22typedef void (elevator_deactivate_req_fn) (request_queue_t *, struct request *);
23
24typedef void *(elevator_init_fn) (request_queue_t *, elevator_t *);
25typedef void (elevator_exit_fn) (elevator_t *);
26
27struct elevator_ops
28{
29 elevator_merge_fn *elevator_merge_fn;
30 elevator_merged_fn *elevator_merged_fn;
31 elevator_merge_req_fn *elevator_merge_req_fn;
32
33 elevator_dispatch_fn *elevator_dispatch_fn;
34 elevator_add_req_fn *elevator_add_req_fn;
35 elevator_activate_req_fn *elevator_activate_req_fn;
36 elevator_deactivate_req_fn *elevator_deactivate_req_fn;
37
38 elevator_queue_empty_fn *elevator_queue_empty_fn;
39 elevator_completed_req_fn *elevator_completed_req_fn;
40
41 elevator_request_list_fn *elevator_former_req_fn;
42 elevator_request_list_fn *elevator_latter_req_fn;
43
44 elevator_set_req_fn *elevator_set_req_fn;
45 elevator_put_req_fn *elevator_put_req_fn;
46
47 elevator_may_queue_fn *elevator_may_queue_fn;
48
49 elevator_init_fn *elevator_init_fn;
50 elevator_exit_fn *elevator_exit_fn;
51 void (*trim)(struct io_context *);
52};
53
54#define ELV_NAME_MAX (16)
55
56struct elv_fs_entry {
57 struct attribute attr;
58 ssize_t (*show)(elevator_t *, char *);
59 ssize_t (*store)(elevator_t *, const char *, size_t);
60};
61
62/*
63 * identifies an elevator type, such as AS or deadline
64 */
65struct elevator_type
66{
67 struct list_head list;
68 struct elevator_ops ops;
69 struct elevator_type *elevator_type;
70 struct elv_fs_entry *elevator_attrs;
71 char elevator_name[ELV_NAME_MAX];
72 struct module *elevator_owner;
73};
74
75/*
76 * each queue has an elevator_queue associated with it
77 */
78struct elevator_queue
79{
80 struct elevator_ops *ops;
81 void *elevator_data;
82 struct kobject kobj;
83 struct elevator_type *elevator_type;
84 struct mutex sysfs_lock;
85 struct hlist_head *hash;
86};
87
88/*
89 * block elevator interface
90 */
91extern void elv_dispatch_sort(request_queue_t *, struct request *);
92extern void elv_dispatch_add_tail(request_queue_t *, struct request *);
93extern void elv_add_request(request_queue_t *, struct request *, int, int);
94extern void __elv_add_request(request_queue_t *, struct request *, int, int);
95extern void elv_insert(request_queue_t *, struct request *, int);
96extern int elv_merge(request_queue_t *, struct request **, struct bio *);
97extern void elv_merge_requests(request_queue_t *, struct request *,
98 struct request *);
99extern void elv_merged_request(request_queue_t *, struct request *);
100extern void elv_dequeue_request(request_queue_t *, struct request *);
101extern void elv_requeue_request(request_queue_t *, struct request *);
102extern int elv_queue_empty(request_queue_t *);
103extern struct request *elv_next_request(struct request_queue *q);
104extern struct request *elv_former_request(request_queue_t *, struct request *);
105extern struct request *elv_latter_request(request_queue_t *, struct request *);
106extern int elv_register_queue(request_queue_t *q);
107extern void elv_unregister_queue(request_queue_t *q);
108extern int elv_may_queue(request_queue_t *, int, struct bio *);
109extern void elv_completed_request(request_queue_t *, struct request *);
110extern int elv_set_request(request_queue_t *, struct request *, struct bio *, gfp_t);
111extern void elv_put_request(request_queue_t *, struct request *);
112
113/*
114 * io scheduler registration
115 */
116extern int elv_register(struct elevator_type *);
117extern void elv_unregister(struct elevator_type *);
118
119/*
120 * io scheduler sysfs switching
121 */
122extern ssize_t elv_iosched_show(request_queue_t *, char *);
123extern ssize_t elv_iosched_store(request_queue_t *, const char *, size_t);
124
125extern int elevator_init(request_queue_t *, char *);
126extern void elevator_exit(elevator_t *);
127extern int elv_rq_merge_ok(struct request *, struct bio *);
128
129/*
130 * Return values from elevator merger
131 */
132#define ELEVATOR_NO_MERGE 0
133#define ELEVATOR_FRONT_MERGE 1
134#define ELEVATOR_BACK_MERGE 2
135
136/*
137 * Insertion selection
138 */
139#define ELEVATOR_INSERT_FRONT 1
140#define ELEVATOR_INSERT_BACK 2
141#define ELEVATOR_INSERT_SORT 3
142#define ELEVATOR_INSERT_REQUEUE 4
143
144/*
145 * return values from elevator_may_queue_fn
146 */
147enum {
148 ELV_MQUEUE_MAY,
149 ELV_MQUEUE_NO,
150 ELV_MQUEUE_MUST,
151};
152
153#define rq_end_sector(rq) ((rq)->sector + (rq)->nr_sectors)
154
155#endif
Linux 6.x block layer and io_uring tree(s)