typedef void (elevator_merged_fn) (request_queue_t *, struct request *);
-typedef struct request *(elevator_next_req_fn) (request_queue_t *);
+typedef int (elevator_dispatch_fn) (request_queue_t *, int);
-typedef void (elevator_add_req_fn) (request_queue_t *, struct request *, int);
+typedef void (elevator_add_req_fn) (request_queue_t *, struct request *);
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 void (elevator_set_congested_fn) (request_queue_t *);
+typedef int (elevator_may_queue_fn) (request_queue_t *, int, struct bio *);
-typedef int (elevator_set_req_fn) (request_queue_t *, struct request *, int);
+typedef int (elevator_set_req_fn) (request_queue_t *, struct request *, struct bio *, gfp_t);
typedef void (elevator_put_req_fn) (request_queue_t *, struct request *);
+typedef void (elevator_activate_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) (request_queue_t *, elevator_t *);
+typedef void (elevator_exit_fn) (elevator_t *);
-struct elevator_s
+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_dispatch_fn *elevator_dispatch_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_activate_req_fn *elevator_activate_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_put_req_fn *elevator_put_req_fn;
elevator_may_queue_fn *elevator_may_queue_fn;
- elevator_set_congested_fn *elevator_set_congested_fn;
elevator_init_fn *elevator_init_fn;
elevator_exit_fn *elevator_exit_fn;
+};
- void *elevator_data;
+#define ELV_NAME_MAX (16)
- struct kobject kobj;
+/*
+ * 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;
- const char *elevator_name;
+ char elevator_name[ELV_NAME_MAX];
+ struct module *elevator_owner;
+};
+
+/*
+ * each queue has an elevator_queue associated 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_dispatch_sort(request_queue_t *, struct request *);
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 void elv_insert(request_queue_t *, struct request *, 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_dequeue_request(request_queue_t *, struct request *);
extern void elv_requeue_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_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_set_congested(request_queue_t *);
+extern int elv_may_queue(request_queue_t *, int, struct bio *);
extern void elv_completed_request(request_queue_t *, struct request *);
-extern int elv_set_request(request_queue_t *, struct request *, int);
+extern int elv_set_request(request_queue_t *, struct request *, struct bio *, gfp_t);
extern void elv_put_request(request_queue_t *, struct request *);
/*
- * noop I/O scheduler. always merges, always inserts new request at tail
- */
-extern elevator_t elevator_noop;
-
-/*
- * deadline i/o scheduler. uses request time outs to prevent indefinite
- * starvation
+ * io scheduler registration
*/
-extern elevator_t iosched_deadline;
+extern int elv_register(struct elevator_type *);
+extern void elv_unregister(struct elevator_type *);
/*
- * anticipatory I/O scheduler
+ * io scheduler sysfs switching
*/
-extern elevator_t iosched_as;
+extern ssize_t elv_iosched_show(request_queue_t *, char *);
+extern ssize_t elv_iosched_store(request_queue_t *, const char *, size_t);
-/*
- * completely fair queueing I/O scheduler
- */
-extern elevator_t iosched_cfq;
-
-extern int elevator_init(request_queue_t *, elevator_t *);
-extern void elevator_exit(request_queue_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_INSERT_FRONT 1
#define ELEVATOR_INSERT_BACK 2
#define ELEVATOR_INSERT_SORT 3
+#define ELEVATOR_INSERT_REQUEUE 4
+
+/*
+ * return values from elevator_may_queue_fn
+ */
+enum {
+ ELV_MQUEUE_MAY,
+ ELV_MQUEUE_NO,
+ ELV_MQUEUE_MUST,
+};
-#define RQ_ELV_DATA(rq) (rq)->elevator_private
+#define rq_end_sector(rq) ((rq)->sector + (rq)->nr_sectors)
#endif