1 files changed, 62 insertions, 6 deletions

diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index 1713ace808bf..b3370ef5164d 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -1,12 +1,16 @@
 #ifndef _LINUX_ELEVATOR_H
 #define _LINUX_ELEVATOR_H
 
+#include <linux/percpu.h>
+
+#ifdef CONFIG_BLOCK
+
 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 void (elevator_merged_fn) (request_queue_t *, struct request *, int);
 
 typedef int (elevator_dispatch_fn) (request_queue_t *, int);
 
@@ -14,9 +18,9 @@ typedef void (elevator_add_req_fn) (request_queue_t *, struct request *);
 typedef int (elevator_queue_empty_fn) (request_queue_t *);
 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, struct bio *);
+typedef int (elevator_may_queue_fn) (request_queue_t *, int);
 
-typedef int (elevator_set_req_fn) (request_queue_t *, struct request *, struct bio *, gfp_t);
+typedef int (elevator_set_req_fn) (request_queue_t *, struct request *, 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 *);
@@ -82,19 +86,21 @@ struct elevator_queue
         struct kobject kobj;
         struct elevator_type *elevator_type;
         struct mutex sysfs_lock;
+        struct hlist_head *hash;
 };
 
 /*
  * block elevator interface
  */
 extern void elv_dispatch_sort(request_queue_t *, struct request *);
+extern void elv_dispatch_add_tail(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_merged_request(request_queue_t *, struct request *, int);
 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 *);
@@ -103,9 +109,9 @@ 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, struct bio *);
+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 *, struct bio *, gfp_t);
+extern int elv_set_request(request_queue_t *, struct request *, gfp_t);
 extern void elv_put_request(request_queue_t *, struct request *);
 
 /*
@@ -125,6 +131,19 @@ extern void elevator_exit(elevator_t *);
 extern int elv_rq_merge_ok(struct request *, struct bio *);
 
 /*
+ * Helper functions.
+ */
+extern struct request *elv_rb_former_request(request_queue_t *, struct request *);
+extern struct request *elv_rb_latter_request(request_queue_t *, struct request *);
+
+/*
+ * rb support functions.
+ */
+extern struct request *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
@@ -149,5 +168,42 @@ enum {
 };
 
 #define rq_end_sector(rq)       ((rq)->sector + (rq)->nr_sectors)
+#define rb_entry_rq(node)       rb_entry((node), struct request, rb_node)
+
+/*
+ * Hack to reuse the donelist 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)->donelist.next)
+#define rq_set_fifo_time(rq,exp)        ((rq)->donelist.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)->donelist);        \
+        } while (0)
 
+/*
+ * io context count accounting
+ */
+#define elv_ioc_count_mod(name, __val)                          \
+        do {                                                    \
+                preempt_disable();                              \
+                __get_cpu_var(name) += (__val);                 \
+                preempt_enable();                               \
+        } while (0)
+
+#define elv_ioc_count_inc(name) elv_ioc_count_mod(name, 1)
+#define elv_ioc_count_dec(name) elv_ioc_count_mod(name, -1)
+
+#define elv_ioc_count_read(name)                                \
+({                                                              \
+        unsigned long __val = 0;                                \
+        int __cpu;                                              \
+        smp_wmb();                                              \
+        for_each_possible_cpu(__cpu)                            \
+                __val += per_cpu(name, __cpu);                  \
+        __val;                                                  \
+})
+
+#endif /* CONFIG_BLOCK */
 #endif