From 3ffbc1d65583394be12801655781dd2b079ce169 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Wed, 19 Jul 2017 14:05:01 +1000 Subject: [PATCH] net/sunrpc/xprt_sock: fix regression in connection error reporting. Commit 3d4762639dd3 ("tcp: remove poll() flakes when receiving RST") in v4.12 changed the order in which ->sk_state_change() and ->sk_error_report() are called when a socket is shut down - sk_state_change() is now called first. This causes xs_tcp_state_change() -> xs_sock_mark_closed() -> xprt_disconnect_done() to wake all pending tasked with -EAGAIN. When the ->sk_error_report() callback arrives, it is too late to pass the error on, and it is lost. As easy way to demonstrate the problem caused is to try to start rpc.nfsd while rcpbind isn't running. nfsd will attempt a tcp connection to rpcbind. A ECONNREFUSED error is returned, but sunrpc code loses the error and keeps retrying. If it saw the ECONNREFUSED, it would abort. To fix this, handle the sk->sk_err in the TCP_CLOSE branch of xs_tcp_state_change(). Fixes: 3d4762639dd3 ("tcp: remove poll() flakes when receiving RST") Cc: stable@vger.kernel.org (v4.12) Signed-off-by: NeilBrown Signed-off-by: Anna Schumaker --- net/sunrpc/xprtsock.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index d5b54c020dec..4f154d388748 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -1624,6 +1624,8 @@ static void xs_tcp_state_change(struct sock *sk) if (test_and_clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state)) xprt_clear_connecting(xprt); + if (sk->sk_err) + xprt_wake_pending_tasks(xprt, -sk->sk_err); xs_sock_mark_closed(xprt); } out: -- 2.20.1