[PATCH] RPC: add generic interface for adjusting the congestion window

 A new interface that allows transports to adjust their congestion window
 using the Van Jacobson implementation in xprt.c is provided.

 Test-plan:
 Use WAN simulation to cause sporadic bursty packet loss.  Look for
 significant regression in performance or client stability.

 Signed-off-by: Chuck Lever <cel@netapp.com>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 443c3f9..2e48752 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -258,9 +258,10 @@
 void			xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
 void			xprt_wait_for_buffer_space(struct rpc_task *task);
 void			xprt_write_space(struct rpc_xprt *xprt);
+void			xprt_update_rtt(struct rpc_task *task);
 void			xprt_adjust_cwnd(struct rpc_task *task, int result);
 struct rpc_rqst *	xprt_lookup_rqst(struct rpc_xprt *xprt, u32 xid);
-void			xprt_complete_rqst(struct rpc_xprt *xprt, struct rpc_rqst *req, int copied);
+void			xprt_complete_rqst(struct rpc_task *task, int copied);
 void			xprt_disconnect(struct rpc_xprt *xprt);
 
 /*