SUNRPC: Don't disconnect more than once if retransmitting NFSv4 requests

NFSv4 requires us to ensure that we break the TCP connection before we're
allowed to retransmit a request. However in the case where we're
retransmitting several requests that have been sent on the same
connection, we need to ensure that we don't interfere with the attempt to
reconnect and/or break the connection again once it has been established.

We therefore introduce a 'connection' cookie that is bumped every time a
connection is broken. This allows requests to track if they need to force a
disconnection.

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

1 files changed, 2 insertions, 0 deletions

diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 4a567a93e6ad..63d79e347c00 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -1142,6 +1142,7 @@ static void xs_tcp_state_change(struct sock *sk)
                 break;
         case TCP_FIN_WAIT1:
                 /* The client initiated a shutdown of the socket */
+                xprt->connect_cookie++;
                 xprt->reestablish_timeout = 0;
                 set_bit(XPRT_CLOSING, &xprt->state);
                 smp_mb__before_clear_bit();
@@ -1154,6 +1155,7 @@ static void xs_tcp_state_change(struct sock *sk)
                 set_bit(XPRT_CLOSING, &xprt->state);
                 xprt_force_disconnect(xprt);
         case TCP_SYN_SENT:
+                xprt->connect_cookie++;
         case TCP_CLOSING:
                 /*
                  * If the server closed down the connection, make sure that