> On 2010-08-03 10:11, Andrew Morton wrote: > > (cc linux-nfs) > > > > On Tue, 03 Aug 2010 01:21:44 -0700 (PDT) David > Miller<davem@xxxxxxxxxxxxx> wrote: > > > >> From: "Andy Chittenden"<andyc.bluearc@xxxxxxxxx> > >> Date: Tue, 3 Aug 2010 09:14:31 +0100 > >> > >>> I don't know whether this patch is the correct fix or not but it > enables the > >>> NFS client to recover. > >>> > >>> Kernel version: 2.6.34.1 and 2.6.32. > >>> > >>> Fixes<https://bugzilla.kernel.org/show_bug.cgi?id=16494>. It clears > down > >>> any previous shutdown attempts so that reconnects on a socket > that's been > >>> shutdown leave the socket in a usable state (otherwise > tcp_sendmsg() returns > >>> -EPIPE). > >> > >> If the SunRPC code wants to close a TCP socket then use it again, > >> it should disconnect by doing a connect() with sa_family == > AF_UNSPEC > > There is code to do that in the SunRPC code in xs_abort_connection() > but > that's conditionally called from xs_tcp_reuse_connection(): > > static void xs_tcp_reuse_connection(struct rpc_xprt *xprt, struct > sock_xprt *transport) > { > unsigned int state = transport->inet->sk_state; > > if (state == TCP_CLOSE && transport->sock->state == > SS_UNCONNECTED) > return; > if ((1 << state) & (TCPF_ESTABLISHED|TCPF_SYN_SENT)) > return; > xs_abort_connection(xprt, transport); > } > > That's changed since 2.6.26 where it unconditionally did the connect() > with sa_family == AF_UNSPEC. FWIW we cannot reproduce this problem with > 2.6.26. The problem is fixed with this patch which also prints out that sk_shutdown can be non-zero on entry to xs_tcp_reuse_connection: # diff -up /home/company/software/src/linux-2.6.34.2/net/sunrpc/xprtsock.c net/sunrpc/xprtsock.c --- /home/company/software/src/linux-2.6.34.2/net/sunrpc/xprtsock.c 2010-08-02 18:30:51.000000000 +0100 +++ net/sunrpc/xprtsock.c 2010-08-05 12:21:11.000000000 +0100 @@ -1322,10 +1322,11 @@ static void xs_tcp_state_change(struct s if (!(xprt = xprt_from_sock(sk))) goto out; dprintk("RPC: xs_tcp_state_change client %p...\n", xprt); - dprintk("RPC: state %x conn %d dead %d zapped %d\n", + dprintk("RPC: state %x conn %d dead %d zapped %d sk_shutdown %d\n", sk->sk_state, xprt_connected(xprt), sock_flag(sk, SOCK_DEAD), - sock_flag(sk, SOCK_ZAPPED)); + sock_flag(sk, SOCK_ZAPPED), + sk->sk_shutdown); switch (sk->sk_state) { case TCP_ESTABLISHED: @@ -1796,10 +1797,18 @@ static void xs_tcp_reuse_connection(stru { unsigned int state = transport->inet->sk_state; - if (state == TCP_CLOSE && transport->sock->state == SS_UNCONNECTED) - return; - if ((1 << state) & (TCPF_ESTABLISHED|TCPF_SYN_SENT)) - return; + if (state == TCP_CLOSE && transport->sock->state == SS_UNCONNECTED) { + if (transport->inet->sk_shutdown == 0) + return; + printk("%s: TCP_CLOSEd and sk_shutdown set to %d\n", + __func__, transport->inet->sk_shutdown); + } + if ((1 << state) & (TCPF_ESTABLISHED|TCPF_SYN_SENT)) { + if (transport->inet->sk_shutdown == 0) + return; + printk("%s: sk_shutdown set to %d\n", + __func__, transport->inet->sk_shutdown); + } xs_abort_connection(xprt, transport); } Signed-off-by: Andy Chittenden <andyc.bluearc@xxxxxxxxx> dmesg displays: [ 2840.896043] xs_tcp_reuse_connection: TCP_CLOSEd and sk_shutdown set to 2 so previously the code was attempting to reuse the connection but wasn't aborting it and thus didn't clear down sk_shutdown. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
