Re: [PATCH 1/3] SUNRPC: Ensure the server closes sockets in a timely fashion

[Tom Tucker <tom@opengridcomputing.com>]

Trond Myklebust wrote:
> We want to ensure that connected sockets close down the connection when we
> set XPT_CLOSE, so that we don't keep it hanging while cleaning up all the
> stuff that is keeping a reference to the socket.
> 
> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
> ---
> 
>  net/sunrpc/svcsock.c |   21 ++++++++++++++++++++-
>  1 files changed, 20 insertions(+), 1 deletions(-)
> 
> 
> diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
> index 95293f5..a1b048d 100644
> --- a/net/sunrpc/svcsock.c
> +++ b/net/sunrpc/svcsock.c
> @@ -59,6 +59,7 @@ static void		svc_udp_data_ready(struct sock *, int);
>  static int		svc_udp_recvfrom(struct svc_rqst *);
>  static int		svc_udp_sendto(struct svc_rqst *);
>  static void		svc_sock_detach(struct svc_xprt *);
> +static void		svc_tcp_sock_detach(struct svc_xprt *);
>  static void		svc_sock_free(struct svc_xprt *);
>  
>  static struct svc_xprt *svc_create_socket(struct svc_serv *, int,
> @@ -1017,7 +1018,7 @@ static struct svc_xprt_ops svc_tcp_ops = {
>  	.xpo_recvfrom = svc_tcp_recvfrom,
>  	.xpo_sendto = svc_tcp_sendto,
>  	.xpo_release_rqst = svc_release_skb,
> -	.xpo_detach = svc_sock_detach,
> +	.xpo_detach = svc_tcp_sock_detach,
>  	.xpo_free = svc_sock_free,
>  	.xpo_prep_reply_hdr = svc_tcp_prep_reply_hdr,
>  	.xpo_has_wspace = svc_tcp_has_wspace,
> @@ -1282,6 +1283,24 @@ static void svc_sock_detach(struct svc_xprt *xprt)
>  	sk->sk_state_change = svsk->sk_ostate;
>  	sk->sk_data_ready = svsk->sk_odata;
>  	sk->sk_write_space = svsk->sk_owspace;
> +
> +	if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
> +		wake_up_interruptible(sk->sk_sleep);
> +}
> +
> +/*
> + * Disconnect the socket, and reset the callbacks
> + */
> +static void svc_tcp_sock_detach(struct svc_xprt *xprt)
> +{
> +	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
> +
> +	dprintk("svc: svc_tcp_sock_detach(%p)\n", svsk);
> +
> +	svc_sock_detach(xprt);
> +
> +	if (!test_bit(XPT_LISTENER, &xprt->xpt_flags))
> +		kernel_sock_shutdown(svsk->sk_sock, SHUT_RDWR);

How is this different than what happens as an artifact of sock_release?

>  }
>  
>  /*
>