[PATCH] deadline IO scheduler dispatching fix

Patch from Nick Piggin <piggin@cyberone.com.au>

Closes a window in which we can get an invalid (already dispatched) request
in the next_drq cache.

This fixed an oops which was reported by Janet Morgan.

diff --git a/drivers/block/deadline-iosched.c b/drivers/block/deadline-iosched.c
index 012269836beffbccc79003cad5e0a42a03424d60..a107ec9682ce77aea4412a9e82ad2f74c0ff42d6 100644 (file)
--- a/drivers/block/deadline-iosched.c
+++ b/drivers/block/deadline-iosched.c
@@ -98,7 +98,7 @@ struct deadline_rq {
        unsigned long expires;
 };
 
-static inline void deadline_move_to_dispatch(struct deadline_data *dd, struct deadline_rq *drq);
+static void deadline_move_request(struct deadline_data *dd, struct deadline_rq *drq);
 
 static kmem_cache_t *drq_pool;
 
@@ -205,7 +205,7 @@ retry:
                return;
        }
 
-       deadline_move_to_dispatch(dd, __alias);
+       deadline_move_request(dd, __alias);
        goto retry;
 }