diff --git a/[refs] b/[refs]
index 2494dc39830e..20cd6728d236 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: da775265021b61d5eb81df155e36cb0810f6df53
+refs/heads/master: 126ec9a676f601818dc3a85af0552b146410d888
diff --git a/trunk/Documentation/block/biodoc.txt b/trunk/Documentation/block/biodoc.txt
index c6c9a9c10d7f..3adaace328a6 100644
--- a/trunk/Documentation/block/biodoc.txt
+++ b/trunk/Documentation/block/biodoc.txt
@@ -946,6 +946,13 @@ elevator_merged_fn		called when a request in the scheduler has been
 				scheduler for example, to reposition the request
 				if its sorting order has changed.
 
+elevator_allow_merge_fn		called whenever the block layer determines
+				that a bio can be merged into an existing
+				request safely. The io scheduler may still
+				want to stop a merge at this point if it
+				results in some sort of conflict internally,
+				this hook allows it to do that.
+
 elevator_dispatch_fn		fills the dispatch queue with ready requests.
 				I/O schedulers are free to postpone requests by
 				not filling the dispatch queue unless @force