Re: It's back! (Re: [REGRESSION] NFS is creating a hidden port (left over from xs_bind() ))

From: Daniel Reichelt
Date: Tue Feb 06 2018 - 04:20:37 EST


On 02/06/2018 01:24 AM, Trond Myklebust wrote:
> Does the following fix the issue?
>
> 8<-----------------------------------------------
> From 9b30889c548a4d45bfe6226e58de32504c1d682f Mon Sep 17 00:00:00 2001
> From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
> Date: Mon, 5 Feb 2018 10:20:06 -0500
> Subject: [PATCH] SUNRPC: Ensure we always close the socket after a connection
> shuts down
>
> Ensure that we release the TCP socket once it is in the TCP_CLOSE or
> TCP_TIME_WAIT state (and only then) so that we don't confuse rkhunter
> and its ilk.
>
> Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
> ---
> net/sunrpc/xprtsock.c | 23 ++++++++++-------------
> 1 file changed, 10 insertions(+), 13 deletions(-)
>
> diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
> index 18803021f242..5d0108172ed3 100644
> --- a/net/sunrpc/xprtsock.c
> +++ b/net/sunrpc/xprtsock.c
> @@ -807,13 +807,6 @@ static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
> smp_mb__after_atomic();
> }
>
> -static void xs_sock_mark_closed(struct rpc_xprt *xprt)
> -{
> - xs_sock_reset_connection_flags(xprt);
> - /* Mark transport as closed and wake up all pending tasks */
> - xprt_disconnect_done(xprt);
> -}
> -
> /**
> * xs_error_report - callback to handle TCP socket state errors
> * @sk: socket
> @@ -833,9 +826,6 @@ static void xs_error_report(struct sock *sk)
> err = -sk->sk_err;
> if (err == 0)
> goto out;
> - /* Is this a reset event? */
> - if (sk->sk_state == TCP_CLOSE)
> - xs_sock_mark_closed(xprt);
> dprintk("RPC: xs_error_report client %p, error=%d...\n",
> xprt, -err);
> trace_rpc_socket_error(xprt, sk->sk_socket, err);
> @@ -1655,9 +1645,11 @@ static void xs_tcp_state_change(struct sock *sk)
> if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
> &transport->sock_state))
> xprt_clear_connecting(xprt);
> + clear_bit(XPRT_CLOSING, &xprt->state);
> if (sk->sk_err)
> xprt_wake_pending_tasks(xprt, -sk->sk_err);
> - xs_sock_mark_closed(xprt);
> + /* Trigger the socket release */
> + xs_tcp_force_close(xprt);
> }
> out:
> read_unlock_bh(&sk->sk_callback_lock);
> @@ -2265,14 +2257,19 @@ static void xs_tcp_shutdown(struct rpc_xprt *xprt)
> {
> struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
> struct socket *sock = transport->sock;
> + int skst = transport->inet ? transport->inet->sk_state : TCP_CLOSE;
>
> if (sock == NULL)
> return;
> - if (xprt_connected(xprt)) {
> + switch (skst) {
> + default:
> kernel_sock_shutdown(sock, SHUT_RDWR);
> trace_rpc_socket_shutdown(xprt, sock);
> - } else
> + break;
> + case TCP_CLOSE:
> + case TCP_TIME_WAIT:
> xs_reset_transport(transport);
> + }
> }
>
> static void xs_tcp_set_socket_timeouts(struct rpc_xprt *xprt,
>


Previously, I've seen hidden ports within 5-6 minutes after re-starting
the nfsd and re-mounting nfs-exports on clients.

With this patch applied, I don't see any hidden ports after 15mins. I
guess it's a valid fix.


Thank you!

Daniel

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