1 files changed, 29 insertions, 0 deletions

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);