[RFC][PATCH] sunrpc: cancel delayed connect working after connceting success

[RFC][PATCH] sunrpc: cancel delayed connect working after connceting success

[Mi Jinlong]

The SUNRPC's TCP connecting is asynchronous, but the tcp_connect()
only send a SYN but don't waiting for the ACK reply.

The below will cause a delayed connect working exist after connecting success.

    CLIENT                                   SERVER

  1. The first connecting

    |-xs_connect()
     |-kernel_connect(O_NONBLOCK)
       |-tcp_connet()  -------- SYN --------->

   xs_connect() return with EINPROGRESS and the ACK have not reply. 

  2. a reconnecting of 1
    |-xs_connect()
        queue_delayed_work(rpciod_workqueue,
                            &transport->connect_worker,
                            xprt->reestablish_timeout);

              <---------------ACK SYN--------------

   After the reconnecting have put the connect working to connect_worker,
   the ACK-SYN for the first connecting reply.

At this instance, a delayed connect working will be exist at connect_worker
after connecting success, we should cancel the working.

Signed-off-by: Mi Jinlong <mijinlong@cn.fujitsu.com>

---
 net/sunrpc/xprtsock.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 49a62f0..823f1db 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -1324,6 +1324,10 @@ static void xs_tcp_state_change(struct sock *sk)
 			transport->tcp_flags =
 				TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
 
+			if (xprt_connecting(xprt) &&
+			      cancel_delayed_work(&transport->connect_worker))
+				xprt_clear_connecting(xprt);
+
 			xprt_wake_pending_tasks(xprt, -EAGAIN);
 		}
 		spin_unlock_bh(&xprt->transport_lock);
-- 1.7.0