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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 422 | giacomo | 1 | #ifndef _LINUX_ELEVATOR_H |
| 2 | #define _LINUX_ELEVATOR_H |
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| 3 | |||
| 4 | typedef int (elevator_merge_fn) (request_queue_t *, struct request **, |
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| 5 | struct bio *); |
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| 6 | |||
| 7 | typedef void (elevator_merge_req_fn) (request_queue_t *, struct request *, struct request *); |
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| 8 | |||
| 9 | typedef void (elevator_merged_fn) (request_queue_t *, struct request *); |
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| 10 | |||
| 11 | typedef struct request *(elevator_next_req_fn) (request_queue_t *); |
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| 12 | |||
| 13 | typedef void (elevator_add_req_fn) (request_queue_t *, struct request *, int); |
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| 14 | typedef int (elevator_queue_empty_fn) (request_queue_t *); |
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| 15 | typedef void (elevator_remove_req_fn) (request_queue_t *, struct request *); |
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| 16 | typedef void (elevator_requeue_req_fn) (request_queue_t *, struct request *); |
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| 17 | typedef struct request *(elevator_request_list_fn) (request_queue_t *, struct request *); |
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| 18 | typedef void (elevator_completed_req_fn) (request_queue_t *, struct request *); |
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| 19 | typedef int (elevator_may_queue_fn) (request_queue_t *, int); |
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| 20 | |||
| 21 | typedef int (elevator_set_req_fn) (request_queue_t *, struct request *, int); |
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| 22 | typedef void (elevator_put_req_fn) (request_queue_t *, struct request *); |
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| 23 | |||
| 24 | typedef int (elevator_init_fn) (request_queue_t *, elevator_t *); |
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| 25 | typedef void (elevator_exit_fn) (request_queue_t *, elevator_t *); |
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| 26 | |||
| 27 | struct elevator_s |
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| 28 | { |
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| 29 | elevator_merge_fn *elevator_merge_fn; |
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| 30 | elevator_merged_fn *elevator_merged_fn; |
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| 31 | elevator_merge_req_fn *elevator_merge_req_fn; |
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| 32 | |||
| 33 | elevator_next_req_fn *elevator_next_req_fn; |
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| 34 | elevator_add_req_fn *elevator_add_req_fn; |
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| 35 | elevator_remove_req_fn *elevator_remove_req_fn; |
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| 36 | elevator_requeue_req_fn *elevator_requeue_req_fn; |
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| 37 | |||
| 38 | elevator_queue_empty_fn *elevator_queue_empty_fn; |
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| 39 | elevator_completed_req_fn *elevator_completed_req_fn; |
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| 40 | |||
| 41 | elevator_request_list_fn *elevator_former_req_fn; |
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| 42 | elevator_request_list_fn *elevator_latter_req_fn; |
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| 43 | |||
| 44 | elevator_set_req_fn *elevator_set_req_fn; |
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| 45 | elevator_put_req_fn *elevator_put_req_fn; |
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| 46 | |||
| 47 | elevator_may_queue_fn *elevator_may_queue_fn; |
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| 48 | |||
| 49 | elevator_init_fn *elevator_init_fn; |
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| 50 | elevator_exit_fn *elevator_exit_fn; |
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| 51 | |||
| 52 | void *elevator_data; |
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| 53 | |||
| 54 | struct kobject kobj; |
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| 55 | struct kobj_type *elevator_ktype; |
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| 56 | const char *elevator_name; |
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| 57 | }; |
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| 58 | |||
| 59 | /* |
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| 60 | * block elevator interface |
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| 61 | */ |
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| 62 | extern void elv_add_request(request_queue_t *, struct request *, int, int); |
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| 63 | extern void __elv_add_request(request_queue_t *, struct request *, int, int); |
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| 64 | extern int elv_merge(request_queue_t *, struct request **, struct bio *); |
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| 65 | extern void elv_merge_requests(request_queue_t *, struct request *, |
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| 66 | struct request *); |
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| 67 | extern void elv_merged_request(request_queue_t *, struct request *); |
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| 68 | extern void elv_remove_request(request_queue_t *, struct request *); |
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| 69 | extern void elv_requeue_request(request_queue_t *, struct request *); |
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| 70 | extern int elv_queue_empty(request_queue_t *); |
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| 71 | extern struct request *elv_next_request(struct request_queue *q); |
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| 72 | extern struct request *elv_former_request(request_queue_t *, struct request *); |
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| 73 | extern struct request *elv_latter_request(request_queue_t *, struct request *); |
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| 74 | extern int elv_register_queue(request_queue_t *q); |
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| 75 | extern void elv_unregister_queue(request_queue_t *q); |
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| 76 | extern int elv_may_queue(request_queue_t *, int); |
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| 77 | extern void elv_completed_request(request_queue_t *, struct request *); |
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| 78 | extern int elv_set_request(request_queue_t *, struct request *, int); |
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| 79 | extern void elv_put_request(request_queue_t *, struct request *); |
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| 80 | |||
| 81 | /* |
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| 82 | * noop I/O scheduler. always merges, always inserts new request at tail |
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| 83 | */ |
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| 84 | extern elevator_t elevator_noop; |
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| 85 | |||
| 86 | /* |
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| 87 | * deadline i/o scheduler. uses request time outs to prevent indefinite |
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| 88 | * starvation |
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| 89 | */ |
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| 90 | extern elevator_t iosched_deadline; |
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| 91 | |||
| 92 | /* |
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| 93 | * anticipatory I/O scheduler |
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| 94 | */ |
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| 95 | extern elevator_t iosched_as; |
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| 96 | |||
| 97 | extern int elevator_init(request_queue_t *, elevator_t *); |
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| 98 | extern void elevator_exit(request_queue_t *); |
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| 99 | extern inline int elv_rq_merge_ok(struct request *, struct bio *); |
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| 100 | extern inline int elv_try_merge(struct request *, struct bio *); |
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| 101 | extern inline int elv_try_last_merge(request_queue_t *, struct bio *); |
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| 102 | |||
| 103 | /* |
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| 104 | * Return values from elevator merger |
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| 105 | */ |
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| 106 | #define ELEVATOR_NO_MERGE 0 |
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| 107 | #define ELEVATOR_FRONT_MERGE 1 |
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| 108 | #define ELEVATOR_BACK_MERGE 2 |
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| 109 | |||
| 110 | /* |
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| 111 | * Insertion selection |
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| 112 | */ |
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| 113 | #define ELEVATOR_INSERT_FRONT 1 |
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| 114 | #define ELEVATOR_INSERT_BACK 2 |
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| 115 | #define ELEVATOR_INSERT_SORT 3 |
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| 116 | |||
| 117 | #endif |