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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/elevator.h
Linux-2.6.12-rc2v2.6.12-rc2
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!
Diffstat (limited to 'include/linux/elevator.h')
-rw-r--r--include/linux/elevator.h145
1 files changed, 145 insertions, 0 deletions
diff --git a/include/linux/elevator.h b/include/linux/elevator.h
new file mode 100644
index 000000000000..ee54f81faad5
--- /dev/null
+++ b/include/linux/elevator.h
@@ -0,0 +1,145 @@
+#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