4 files changed, 43 insertions, 2 deletions

diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 8a0629abb86a..4d80a118d538 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -86,6 +86,10 @@ struct rpc_rqst {
         unsigned long           rq_majortimeo;  /* major timeout alarm */
         unsigned long           rq_timeout;     /* Current timeout value */
         unsigned int            rq_retries;     /* # of retries */
+        unsigned int            rq_connect_cookie;
+                                                /* A cookie used to track the
+                                                   state of the transport
+                                                   connection */
         
         /*
          * Partial send handling
@@ -152,6 +156,9 @@ struct rpc_xprt {
         unsigned long           connect_timeout,
                                 bind_timeout,
                                 reestablish_timeout;
+        unsigned int            connect_cookie; /* A cookie that gets bumped
+                                                   every time the transport
+                                                   is reconnected */
 
         /*
          * Disconnection of idle transports
@@ -241,6 +248,7 @@ void			xprt_complete_rqst(struct rpc_task *task, int copied);
 void                    xprt_release_rqst_cong(struct rpc_task *task);
 void                    xprt_disconnect_done(struct rpc_xprt *xprt);
 void                    xprt_force_disconnect(struct rpc_xprt *xprt);
+void                    xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
 
 /*
  * Reserved bit positions in xprt->state
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 3ae560464513..8773b4342c92 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1120,7 +1120,8 @@ call_status(struct rpc_task *task)
         case -ETIMEDOUT:
                 task->tk_action = call_timeout;
                 if (task->tk_client->cl_discrtry)
-                        xprt_force_disconnect(task->tk_xprt);
+                        xprt_conditional_disconnect(task->tk_xprt,
+                                        req->rq_connect_cookie);
                 break;
         case -ECONNREFUSED:
         case -ENOTCONN:
@@ -1245,7 +1246,8 @@ out_retry:
         if (task->tk_rqstp == req) {
                 req->rq_received = req->rq_rcv_buf.len = 0;
                 if (task->tk_client->cl_discrtry)
-                        xprt_force_disconnect(task->tk_xprt);
+                        xprt_conditional_disconnect(task->tk_xprt,
+                                        req->rq_connect_cookie);
         }
 }
 
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index a0646a3b4a39..75d748eee0eb 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -606,6 +606,34 @@ void xprt_force_disconnect(struct rpc_xprt *xprt)
         spin_unlock_bh(&xprt->transport_lock);
 }
 
+/**
+ * xprt_conditional_disconnect - force a transport to disconnect
+ * @xprt: transport to disconnect
+ * @cookie: 'connection cookie'
+ *
+ * This attempts to break the connection if and only if 'cookie' matches
+ * the current transport 'connection cookie'. It ensures that we don't
+ * try to break the connection more than once when we need to retransmit
+ * a batch of RPC requests.
+ *
+ */
+void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie)
+{
+        /* Don't race with the test_bit() in xprt_clear_locked() */
+        spin_lock_bh(&xprt->transport_lock);
+        if (cookie != xprt->connect_cookie)
+                goto out;
+        if (test_bit(XPRT_CLOSING, &xprt->state) || !xprt_connected(xprt))
+                goto out;
+        set_bit(XPRT_CLOSE_WAIT, &xprt->state);
+        /* Try to schedule an autoclose RPC call */
+        if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
+                queue_work(rpciod_workqueue, &xprt->task_cleanup);
+        xprt_wake_pending_tasks(xprt, -ENOTCONN);
+out:
+        spin_unlock_bh(&xprt->transport_lock);
+}
+
 static void
 xprt_init_autodisconnect(unsigned long data)
 {
@@ -849,6 +877,7 @@ void xprt_transmit(struct rpc_task *task)
         } else if (!req->rq_bytes_sent)
                 return;
 
+        req->rq_connect_cookie = xprt->connect_cookie;
         status = xprt->ops->send_request(task);
         if (status == 0) {
                 dprintk("RPC: %5u xmit complete\n", task->tk_pid);
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