211 lines
6.9 KiB
C
211 lines
6.9 KiB
C
#ifndef _LINUX_ELEVATOR_H
|
|
#define _LINUX_ELEVATOR_H
|
|
|
|
#include <linux/percpu.h>
|
|
|
|
#ifdef CONFIG_BLOCK
|
|
|
|
struct io_cq;
|
|
|
|
typedef int (elevator_merge_fn) (struct request_queue *, struct request **,
|
|
struct bio *);
|
|
|
|
typedef void (elevator_merge_req_fn) (struct request_queue *, struct request *, struct request *);
|
|
|
|
typedef void (elevator_merged_fn) (struct request_queue *, struct request *, int);
|
|
|
|
typedef int (elevator_allow_merge_fn) (struct request_queue *, struct request *, struct bio *);
|
|
|
|
typedef void (elevator_bio_merged_fn) (struct request_queue *,
|
|
struct request *, struct bio *);
|
|
|
|
typedef int (elevator_dispatch_fn) (struct request_queue *, int);
|
|
|
|
typedef void (elevator_add_req_fn) (struct request_queue *, struct request *);
|
|
typedef struct request *(elevator_request_list_fn) (struct request_queue *, struct request *);
|
|
typedef void (elevator_completed_req_fn) (struct request_queue *, struct request *);
|
|
typedef int (elevator_may_queue_fn) (struct request_queue *, int);
|
|
|
|
typedef void (elevator_init_icq_fn) (struct io_cq *);
|
|
typedef void (elevator_exit_icq_fn) (struct io_cq *);
|
|
typedef int (elevator_set_req_fn) (struct request_queue *, struct request *,
|
|
struct bio *, gfp_t);
|
|
typedef void (elevator_put_req_fn) (struct request *);
|
|
typedef void (elevator_activate_req_fn) (struct request_queue *, struct request *);
|
|
typedef void (elevator_deactivate_req_fn) (struct request_queue *, struct request *);
|
|
|
|
typedef int (elevator_init_fn) (struct request_queue *);
|
|
typedef void (elevator_exit_fn) (struct elevator_queue *);
|
|
|
|
struct elevator_ops
|
|
{
|
|
elevator_merge_fn *elevator_merge_fn;
|
|
elevator_merged_fn *elevator_merged_fn;
|
|
elevator_merge_req_fn *elevator_merge_req_fn;
|
|
elevator_allow_merge_fn *elevator_allow_merge_fn;
|
|
elevator_bio_merged_fn *elevator_bio_merged_fn;
|
|
|
|
elevator_dispatch_fn *elevator_dispatch_fn;
|
|
elevator_add_req_fn *elevator_add_req_fn;
|
|
elevator_activate_req_fn *elevator_activate_req_fn;
|
|
elevator_deactivate_req_fn *elevator_deactivate_req_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_init_icq_fn *elevator_init_icq_fn; /* see iocontext.h */
|
|
elevator_exit_icq_fn *elevator_exit_icq_fn; /* ditto */
|
|
|
|
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)
|
|
|
|
struct elv_fs_entry {
|
|
struct attribute attr;
|
|
ssize_t (*show)(struct elevator_queue *, char *);
|
|
ssize_t (*store)(struct elevator_queue *, const char *, size_t);
|
|
};
|
|
|
|
/*
|
|
* identifies an elevator type, such as AS or deadline
|
|
*/
|
|
struct elevator_type
|
|
{
|
|
/* managed by elevator core */
|
|
struct kmem_cache *icq_cache;
|
|
|
|
/* fields provided by elevator implementation */
|
|
struct elevator_ops ops;
|
|
size_t icq_size; /* see iocontext.h */
|
|
size_t icq_align; /* ditto */
|
|
struct elv_fs_entry *elevator_attrs;
|
|
char elevator_name[ELV_NAME_MAX];
|
|
struct module *elevator_owner;
|
|
|
|
/* managed by elevator core */
|
|
char icq_cache_name[ELV_NAME_MAX + 5]; /* elvname + "_io_cq" */
|
|
struct list_head list;
|
|
};
|
|
|
|
/*
|
|
* each queue has an elevator_queue associated with it
|
|
*/
|
|
struct elevator_queue
|
|
{
|
|
struct elevator_type *type;
|
|
void *elevator_data;
|
|
struct kobject kobj;
|
|
struct mutex sysfs_lock;
|
|
struct hlist_head *hash;
|
|
unsigned int registered:1;
|
|
};
|
|
|
|
/*
|
|
* block elevator interface
|
|
*/
|
|
extern void elv_dispatch_sort(struct request_queue *, struct request *);
|
|
extern void elv_dispatch_add_tail(struct request_queue *, struct request *);
|
|
extern void elv_add_request(struct request_queue *, struct request *, int);
|
|
extern void __elv_add_request(struct request_queue *, struct request *, int);
|
|
extern int elv_merge(struct request_queue *, struct request **, struct bio *);
|
|
extern void elv_merge_requests(struct request_queue *, struct request *,
|
|
struct request *);
|
|
extern void elv_merged_request(struct request_queue *, struct request *, int);
|
|
extern void elv_bio_merged(struct request_queue *q, struct request *,
|
|
struct bio *);
|
|
extern void elv_requeue_request(struct request_queue *, struct request *);
|
|
extern struct request *elv_former_request(struct request_queue *, struct request *);
|
|
extern struct request *elv_latter_request(struct request_queue *, struct request *);
|
|
extern int elv_register_queue(struct request_queue *q);
|
|
extern void elv_unregister_queue(struct request_queue *q);
|
|
extern int elv_may_queue(struct request_queue *, int);
|
|
extern void elv_abort_queue(struct request_queue *);
|
|
extern void elv_completed_request(struct request_queue *, struct request *);
|
|
extern int elv_set_request(struct request_queue *q, struct request *rq,
|
|
struct bio *bio, gfp_t gfp_mask);
|
|
extern void elv_put_request(struct request_queue *, struct request *);
|
|
extern void elv_drain_elevator(struct request_queue *);
|
|
|
|
/*
|
|
* 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(struct request_queue *, char *);
|
|
extern ssize_t elv_iosched_store(struct request_queue *, const char *, size_t);
|
|
|
|
extern int elevator_init(struct request_queue *, char *);
|
|
extern void elevator_exit(struct elevator_queue *);
|
|
extern int elevator_change(struct request_queue *, const char *);
|
|
extern bool elv_rq_merge_ok(struct request *, struct bio *);
|
|
|
|
/*
|
|
* Helper functions.
|
|
*/
|
|
extern struct request *elv_rb_former_request(struct request_queue *, struct request *);
|
|
extern struct request *elv_rb_latter_request(struct request_queue *, struct request *);
|
|
|
|
/*
|
|
* rb support functions.
|
|
*/
|
|
extern void elv_rb_add(struct rb_root *, struct request *);
|
|
extern void elv_rb_del(struct rb_root *, struct request *);
|
|
extern struct request *elv_rb_find(struct rb_root *, sector_t);
|
|
|
|
/*
|
|
* 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
|
|
#define ELEVATOR_INSERT_REQUEUE 4
|
|
#define ELEVATOR_INSERT_FLUSH 5
|
|
#define ELEVATOR_INSERT_SORT_MERGE 6
|
|
|
|
/*
|
|
* return values from elevator_may_queue_fn
|
|
*/
|
|
enum {
|
|
ELV_MQUEUE_MAY,
|
|
ELV_MQUEUE_NO,
|
|
ELV_MQUEUE_MUST,
|
|
};
|
|
|
|
#define rq_end_sector(rq) (blk_rq_pos(rq) + blk_rq_sectors(rq))
|
|
#define rb_entry_rq(node) rb_entry((node), struct request, rb_node)
|
|
|
|
/*
|
|
* Hack to reuse the csd.list list_head as the fifo time holder while
|
|
* the request is in the io scheduler. Saves an unsigned long in rq.
|
|
*/
|
|
#define rq_fifo_time(rq) ((unsigned long) (rq)->csd.list.next)
|
|
#define rq_set_fifo_time(rq,exp) ((rq)->csd.list.next = (void *) (exp))
|
|
#define rq_entry_fifo(ptr) list_entry((ptr), struct request, queuelist)
|
|
#define rq_fifo_clear(rq) do { \
|
|
list_del_init(&(rq)->queuelist); \
|
|
INIT_LIST_HEAD(&(rq)->csd.list); \
|
|
} while (0)
|
|
|
|
#endif /* CONFIG_BLOCK */
|
|
#endif
|