ocfs2: Added post handler callable function in o2net message handler

Currently o2net allows one handler function per message type. This
patch adds the ability to call another function to be called after
the handler has returned the message to the other node.

Handlers are now given the option of returning a context (in the form of a
void **) which will be passed back into the post message handler function.

Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/dlm/dlmast.c b/fs/ocfs2/dlm/dlmast.c
index ad5e7e1..241cad3 100644
--- a/fs/ocfs2/dlm/dlmast.c
+++ b/fs/ocfs2/dlm/dlmast.c
@@ -263,7 +263,8 @@
 
 
 
-int dlm_proxy_ast_handler(struct o2net_msg *msg, u32 len, void *data)
+int dlm_proxy_ast_handler(struct o2net_msg *msg, u32 len, void *data,
+			  void **ret_data)
 {
 	int ret;
 	unsigned int locklen;