[PATCH] [35/98] SUNRPC: fix NFS client over TCP hangs due to packet loss (Bug 16494)

Andi Kleen
2011-07-27T00:35:39Z

From: Andy Chittenden <andyc.bluearc@gmail.com>

commit 669502ff31d7dba1849aec7ee2450a3c61f57d39 upstream.

When reusing a TCP connection, ensure that it's aborted if a previous
shutdown attempt has been made on that connection so that the RPC over
TCP recovery mechanism succeeds.

Signed-off-by: Andy Chittenden <andyc.bluearc@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

---
net/sunrpc/xprtsock.c | 28 ++++++++++++++++++++++------
1 file changed, 22 insertions(+), 6 deletions(-)

Index: linux-2.6.35.y/net/sunrpc/xprtsock.c
===================================================================
--- linux-2.6.35.y.orig/net/sunrpc/xprtsock.c
+++ linux-2.6.35.y/net/sunrpc/xprtsock.c
@@ -1307,10 +1307,11 @@ 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:
@@ -1781,10 +1782,25 @@ 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) {
+ /* we don't need to abort the connection if the socket
+ * hasn't undergone a shutdown
+ */
+ if (transport->inet->sk_shutdown == 0)
+ return;
+ dprintk("RPC: %s: TCP_CLOSEd and sk_shutdown set to %d\n",
+ __func__, transport->inet->sk_shutdown);
+ }
+ if ((1 << state) & (TCPF_ESTABLISHED|TCPF_SYN_SENT)) {
+ /* we don't need to abort the connection if the socket
+ * hasn't undergone a shutdown
+ */
+ if (transport->inet->sk_shutdown == 0)
+ return;
+ dprintk("RPC: %s: ESTABLISHED/SYN_SENT "
+ "sk_shutdown set to %d\n",
+ __func__, transport->inet->sk_shutdown);
+ }
xs_abort_connection(xprt, transport);
}