[PATCH] RPC: add a release_rqst callout to the RPC transport switch

 The final place where congestion control state is adjusted is in
 xprt_release, where each request is finally released.  Add a callout
 there to allow transports to perform additional processing when a
 request is about to be released.

 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>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 2e48752d55d9..64e77658fa30 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -138,6 +138,7 @@ struct rpc_xprt_ops {
         int             (*send_request)(struct rpc_task *task);
         void            (*set_retrans_timeout)(struct rpc_task *task);
         void            (*timer)(struct rpc_task *task);
+        void            (*release_request)(struct rpc_task *task);
         void            (*close)(struct rpc_xprt *xprt);
         void            (*destroy)(struct rpc_xprt *xprt);
 };
@@ -262,6 +263,7 @@ 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_task *task, int copied);
+void                    xprt_release_rqst_cong(struct rpc_task *task);
 void                    xprt_disconnect(struct rpc_xprt *xprt);
 
 /*