To clear out old state, the UDP connect workers unconditionally invoke xs_close() before proceeding with a new connect. Nowadays this causes a spurious wake-up of the task waiting for the connect to complete. This is a little racey, but usually harmless. The waiting task immediately retries the connect via a call_bind/call_connect sequence, which usually finds the transport already in the connected state because the connect worker has finished in the background. To avoid a spurious wake-up, factor the xs_close() logic that resets the underlying socket into a helper, and have the UDP connect workers call that helper instead of xs_close(). Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> --- net/sunrpc/xprtsock.c | 44 ++++++++++++++++++++++++++------------------ 1 files changed, 26 insertions(+), 18 deletions(-) Resending. See http://marc.info/?l=linux-nfs&m=122661089915077&w=2 diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 5cbb404..9f0f68c 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -757,23 +757,13 @@ static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *s sk->sk_error_report = transport->old_error_report; } -/** - * xs_close - close a socket - * @xprt: transport - * - * This is used when all requests are complete; ie, no DRC state remains - * on the server we want to save. - */ -static void xs_close(struct rpc_xprt *xprt) +static void xs_reset_transport(struct sock_xprt *transport) { - struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt); struct socket *sock = transport->sock; struct sock *sk = transport->inet; - if (!sk) - goto clear_close_wait; - - dprintk("RPC: xs_close xprt %p\n", xprt); + if (sk == NULL) + return; write_lock_bh(&sk->sk_callback_lock); transport->inet = NULL; @@ -787,7 +777,23 @@ static void xs_close(struct rpc_xprt *xprt) sk->sk_no_check = 0; sock_release(sock); -clear_close_wait: +} + +/** + * xs_close - close a socket + * @xprt: transport + * + * This is used when all requests are complete; ie, no DRC state remains + * on the server we want to save. + */ +static void xs_close(struct rpc_xprt *xprt) +{ + struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt); + + dprintk("RPC: xs_close xprt %p\n", xprt); + + xs_reset_transport(transport); + smp_mb__before_clear_bit(); clear_bit(XPRT_CLOSE_WAIT, &xprt->state); clear_bit(XPRT_CLOSING, &xprt->state); @@ -1527,9 +1533,10 @@ static void xs_udp_connect_worker4(struct work_struct *work) goto out; /* Start by resetting any existing state */ - xs_close(xprt); + xs_reset_transport(transport); - if ((err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) { + err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock); + if (err < 0) { dprintk("RPC: can't create UDP transport socket (%d).\n", -err); goto out; } @@ -1568,9 +1575,10 @@ static void xs_udp_connect_worker6(struct work_struct *work) goto out; /* Start by resetting any existing state */ - xs_close(xprt); + xs_reset_transport(transport); - if ((err = sock_create_kern(PF_INET6, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) { + err = sock_create_kern(PF_INET6, SOCK_DGRAM, IPPROTO_UDP, &sock); + if (err < 0) { dprintk("RPC: can't create UDP transport socket (%d).\n", -err); goto out; } -- 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
