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/cluster/tcp_internal.h b/fs/ocfs2/cluster/tcp_internal.h
index 775c911..d74040f 100644
--- a/fs/ocfs2/cluster/tcp_internal.h
+++ b/fs/ocfs2/cluster/tcp_internal.h
@@ -161,6 +161,8 @@
 	u32			nh_key;
 	o2net_msg_handler_func	*nh_func;
 	o2net_msg_handler_func	*nh_func_data;
+	o2net_post_msg_handler_func
+				*nh_post_func;
 	struct kref		nh_kref;
 	struct list_head	nh_unregister_item;
 };