--- include/linux/elevator.h
+++ include/linux/elevator.h
@@ -146,7 +146,7 @@ extern struct request *elv_rb_latter_req
/*
* rb support functions.
*/
-extern struct request *elv_rb_add(struct rb_root *, struct request *);
+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);