SUNRPC: Allow the client to detect if the TCP connection is closed

Add an xprt->state bit to enable the TCP ->state_change() method to signal
whether or not the TCP connection is in the process of closing down.
This will to be used by the reconnection logic in a separate patch.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 6f524a9..afb9e6a 100644 (file)
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -257,6 +257,7 @@ void                        xprt_force_disconnect(struct rpc_xprt *xprt);
 #define XPRT_CLOSE_WAIT                (3)
 #define XPRT_BOUND             (4)
 #define XPRT_BINDING           (5)
+#define XPRT_CLOSING           (6)
 
 static inline void xprt_set_connected(struct rpc_xprt *xprt)
 {

diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index b554451..721c541 100644 (file)
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -758,7 +758,9 @@ static void xs_close(struct rpc_xprt *xprt)
        sock_release(sock);
 clear_close_wait:
        smp_mb__before_clear_bit();
+       clear_bit(XPRT_CONNECTED, &xprt->state);
        clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
+       clear_bit(XPRT_CLOSING, &xprt->state);
        smp_mb__after_clear_bit();
 }
 
@@ -1118,12 +1120,28 @@ static void xs_tcp_state_change(struct sock *sk)
                }
                spin_unlock_bh(&xprt->transport_lock);
                break;
-       case TCP_SYN_SENT:
-       case TCP_SYN_RECV:
+       case TCP_FIN_WAIT1:
+               /* The client initiated a shutdown of the socket */
+               set_bit(XPRT_CLOSING, &xprt->state);
+               smp_mb__before_clear_bit();
+               clear_bit(XPRT_CONNECTED, &xprt->state);
+               smp_mb__after_clear_bit();
                break;
        case TCP_CLOSE_WAIT:
+               /* The server initiated a shutdown of the socket */
+               set_bit(XPRT_CLOSING, &xprt->state);
                xprt_force_disconnect(xprt);
-       default:
+               break;
+       case TCP_LAST_ACK:
+               smp_mb__before_clear_bit();
+               clear_bit(XPRT_CONNECTED, &xprt->state);
+               smp_mb__after_clear_bit();
+               break;
+       case TCP_CLOSE:
+               smp_mb__before_clear_bit();
+               clear_bit(XPRT_CLOSING, &xprt->state);
+               smp_mb__after_clear_bit();
+               /* Mark transport as closed and wake up all pending tasks */
                xprt_disconnect(xprt);
        }
  out: