forked from mirrors/linux
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
145 lines
4.7 KiB
C
145 lines
4.7 KiB
C
#ifndef _LINUX_ELEVATOR_H
|
|
#define _LINUX_ELEVATOR_H
|
|
|
|
typedef int (elevator_merge_fn) (request_queue_t *, struct request **,
|
|
struct bio *);
|
|
|
|
typedef void (elevator_merge_req_fn) (request_queue_t *, struct request *, struct request *);
|
|
|
|
typedef void (elevator_merged_fn) (request_queue_t *, struct request *);
|
|
|
|
typedef struct request *(elevator_next_req_fn) (request_queue_t *);
|
|
|
|
typedef void (elevator_add_req_fn) (request_queue_t *, struct request *, int);
|
|
typedef int (elevator_queue_empty_fn) (request_queue_t *);
|
|
typedef void (elevator_remove_req_fn) (request_queue_t *, struct request *);
|
|
typedef void (elevator_requeue_req_fn) (request_queue_t *, struct request *);
|
|
typedef struct request *(elevator_request_list_fn) (request_queue_t *, struct request *);
|
|
typedef void (elevator_completed_req_fn) (request_queue_t *, struct request *);
|
|
typedef int (elevator_may_queue_fn) (request_queue_t *, int);
|
|
|
|
typedef int (elevator_set_req_fn) (request_queue_t *, struct request *, int);
|
|
typedef void (elevator_put_req_fn) (request_queue_t *, struct request *);
|
|
typedef void (elevator_deactivate_req_fn) (request_queue_t *, struct request *);
|
|
|
|
typedef int (elevator_init_fn) (request_queue_t *, elevator_t *);
|
|
typedef void (elevator_exit_fn) (elevator_t *);
|
|
|
|
struct elevator_ops
|
|
{
|
|
elevator_merge_fn *elevator_merge_fn;
|
|
elevator_merged_fn *elevator_merged_fn;
|
|
elevator_merge_req_fn *elevator_merge_req_fn;
|
|
|
|
elevator_next_req_fn *elevator_next_req_fn;
|
|
elevator_add_req_fn *elevator_add_req_fn;
|
|
elevator_remove_req_fn *elevator_remove_req_fn;
|
|
elevator_requeue_req_fn *elevator_requeue_req_fn;
|
|
elevator_deactivate_req_fn *elevator_deactivate_req_fn;
|
|
|
|
elevator_queue_empty_fn *elevator_queue_empty_fn;
|
|
elevator_completed_req_fn *elevator_completed_req_fn;
|
|
|
|
elevator_request_list_fn *elevator_former_req_fn;
|
|
elevator_request_list_fn *elevator_latter_req_fn;
|
|
|
|
elevator_set_req_fn *elevator_set_req_fn;
|
|
elevator_put_req_fn *elevator_put_req_fn;
|
|
|
|
elevator_may_queue_fn *elevator_may_queue_fn;
|
|
|
|
elevator_init_fn *elevator_init_fn;
|
|
elevator_exit_fn *elevator_exit_fn;
|
|
};
|
|
|
|
#define ELV_NAME_MAX (16)
|
|
|
|
/*
|
|
* identifies an elevator type, such as AS or deadline
|
|
*/
|
|
struct elevator_type
|
|
{
|
|
struct list_head list;
|
|
struct elevator_ops ops;
|
|
struct elevator_type *elevator_type;
|
|
struct kobj_type *elevator_ktype;
|
|
char elevator_name[ELV_NAME_MAX];
|
|
struct module *elevator_owner;
|
|
};
|
|
|
|
/*
|
|
* each queue has an elevator_queue assoicated with it
|
|
*/
|
|
struct elevator_queue
|
|
{
|
|
struct elevator_ops *ops;
|
|
void *elevator_data;
|
|
struct kobject kobj;
|
|
struct elevator_type *elevator_type;
|
|
};
|
|
|
|
/*
|
|
* block elevator interface
|
|
*/
|
|
extern void elv_add_request(request_queue_t *, struct request *, int, int);
|
|
extern void __elv_add_request(request_queue_t *, struct request *, int, int);
|
|
extern int elv_merge(request_queue_t *, struct request **, struct bio *);
|
|
extern void elv_merge_requests(request_queue_t *, struct request *,
|
|
struct request *);
|
|
extern void elv_merged_request(request_queue_t *, struct request *);
|
|
extern void elv_remove_request(request_queue_t *, struct request *);
|
|
extern void elv_requeue_request(request_queue_t *, struct request *);
|
|
extern void elv_deactivate_request(request_queue_t *, struct request *);
|
|
extern int elv_queue_empty(request_queue_t *);
|
|
extern struct request *elv_next_request(struct request_queue *q);
|
|
extern struct request *elv_former_request(request_queue_t *, struct request *);
|
|
extern struct request *elv_latter_request(request_queue_t *, struct request *);
|
|
extern int elv_register_queue(request_queue_t *q);
|
|
extern void elv_unregister_queue(request_queue_t *q);
|
|
extern int elv_may_queue(request_queue_t *, int);
|
|
extern void elv_completed_request(request_queue_t *, struct request *);
|
|
extern int elv_set_request(request_queue_t *, struct request *, int);
|
|
extern void elv_put_request(request_queue_t *, struct request *);
|
|
|
|
/*
|
|
* io scheduler registration
|
|
*/
|
|
extern int elv_register(struct elevator_type *);
|
|
extern void elv_unregister(struct elevator_type *);
|
|
|
|
/*
|
|
* io scheduler sysfs switching
|
|
*/
|
|
extern ssize_t elv_iosched_show(request_queue_t *, char *);
|
|
extern ssize_t elv_iosched_store(request_queue_t *, const char *, size_t);
|
|
|
|
extern int elevator_init(request_queue_t *, char *);
|
|
extern void elevator_exit(elevator_t *);
|
|
extern int elv_rq_merge_ok(struct request *, struct bio *);
|
|
extern int elv_try_merge(struct request *, struct bio *);
|
|
extern int elv_try_last_merge(request_queue_t *, struct bio *);
|
|
|
|
/*
|
|
* Return values from elevator merger
|
|
*/
|
|
#define ELEVATOR_NO_MERGE 0
|
|
#define ELEVATOR_FRONT_MERGE 1
|
|
#define ELEVATOR_BACK_MERGE 2
|
|
|
|
/*
|
|
* Insertion selection
|
|
*/
|
|
#define ELEVATOR_INSERT_FRONT 1
|
|
#define ELEVATOR_INSERT_BACK 2
|
|
#define ELEVATOR_INSERT_SORT 3
|
|
|
|
/*
|
|
* return values from elevator_may_queue_fn
|
|
*/
|
|
enum {
|
|
ELV_MQUEUE_MAY,
|
|
ELV_MQUEUE_NO,
|
|
ELV_MQUEUE_MUST,
|
|
};
|
|
|
|
#endif
|