Re: [PATCH] sunrpc: cancel delayed connect working when conncet success

[Trond Myklebust <trond.myklebust@fys.uio.no>]

On Wed, 2010-08-18 at 17:49 +0800, Mi Jinlong wrote:
> As network partition or some other reason, when client connect 
> success, maybe there is some delayed connect working in connect_work list.
> 
> Aug  2 12:51:32 TEST-M kernel: RPC:       xs_connect delayed xprt ccc4c800 for 96 seconds
> Aug  2 12:51:32 TEST-M kernel: RPC:       xs_error_report client ccc4c800...
> Aug  2 12:51:32 TEST-M kernel: RPC:       error 111
>  ... snip ...
> Aug  2 12:53:08 TEST-M kernel: RPC:       disconnected transport ccc4c800
> Aug  2 12:53:08 TEST-M kernel: RPC:       worker connecting xprt ccc4c800 via tcp to 192.168.0.21 (port 2049)
> Aug  2 12:53:08 TEST-M kernel: RPC:       ccc4c800 connect status 115 connected 0 sock state 2
> Aug  2 12:53:08 TEST-M kernel: RPC:   228 xprt_connect_status: retrying
> Aug  2 12:53:08 TEST-M kernel: RPC:   228 xprt_prepare_transmit
> Aug  2 12:53:08 TEST-M kernel: RPC:   228 xprt_transmit(136)
> Aug  2 12:53:08 TEST-M kernel: RPC:       xs_tcp_send_request(136) = -11
> Aug  2 12:53:08 TEST-M kernel: RPC:   228 xmit incomplete (136 left of 136)
> Aug  2 12:53:08 TEST-M kernel: RPC:   228 xprt_connect xprt ccc4c800 is not connected
> Aug  2 12:53:08 TEST-M kernel: RPC:       xs_connect delayed xprt ccc4c800 for 192 seconds
> Aug  2 12:53:08 TEST-M kernel: RPC:       xs_tcp_state_change client ccc4c800...
> Aug  2 12:53:08 TEST-M kernel: RPC:       state 1 conn 0 dead 0 zapped 1
> Aug  2 12:53:08 TEST-M kernel: RPC:   228 xprt_connect_status: retrying
> Aug  2 12:53:08 TEST-M kernel: RPC:   228 xprt_prepare_transmit
> Aug  2 12:53:08 TEST-M kernel: RPC:   228 xprt_transmit(136)
> Aug  2 12:53:08 TEST-M kernel: RPC:       xs_tcp_send_request(136) = 136
> Aug  2 12:53:08 TEST-M kernel: RPC:   228 xmit complete
> Aug  2 12:53:08 TEST-M kernel: RPC:   229 xprt_prepare_transmit
> 
> As the debug message show, "xs_connect delayed xprt ccc4c800 for 192 seconds"
> means a connecting work have be delayed at connect_worker list.
> "state 1 conn 0 dead 0 zapped 1" shows the connect have successed 
> but a delayed work still alive at connect_worker list.
> 
> 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);

Wait... According to the above trace, the connect request is _failing_
due to an ECONNREFUSED error. In that case, we _want_ to delay the
reconnection in order to give the server time to set itself up.

Cheers
  Trond