From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: [PATCH] net/sunrpc/xprt_sock: fix regression in connection error reporting. Date: Wed, 19 Jul 2017 14:05:01 +1000 Message-ID: <87r2xdxeaa.fsf@notabene.neil.brown.name> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Cc: "David S. Miller" , Eric Dumazet To: Trond Myklebust , Anna Schumaker Return-path: Cc: linux-nfs@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable 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 =2D-- 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 =2D-- 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: =2D-=20 2.12.2 --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEG8Yp69OQ2HB7X0l6Oeye3VZigbkFAllu2nAACgkQOeye3VZi gbmeZA//Q8wtVydWnaSmch48kUWOy8LYkVv1uHUVm7vTce+4Sd9321lgkgAOI+Cc h8s6AipYKGTFyBm/Kssii+Oa33F4+TT+9NBP7GDf7j/5b/vq35ozR/Xmc+Ra+xJW FC++eibIl6YDnZH2S918mgt29qBpomvPF/YN0itlfIatPiZ3OpNMa4a54vz2s6JA 5TcfZJJoAvSvm9RbF7/5eQs1YkxpvvYnVw+6k+QNHLEkUAqZOKqp1dYXFjayofz3 27QzvwDvzuPHG3ikhacypRbhkVDwc0zgXADDEnXX6vEQyHy9MlRZSS3q4yBYukvT HlhMydrHaaa/ZfGE8LSZKXz5fJMFGf9GkEIw8DCR4g1dYuysTU/avvtX1n4kOeDE bWsCcsW8ZJ6fD0Cer7eEUEyAsDNdoXPV+a9LFfDsD6skB/heJ2UsIPdWGXQG59Mc ZA1KiiUPjw8xvFzyX4uliukXbCLvi+IsFIQhvGPaAMzzLLrS3NTBTam98WvuEiOQ EM5guYgf2OR455egWtCLONB/DfXQUS7mb4QVxUQLHJ3T+yQrrUYN+6dS2sWwGESx Ny5jbNjdJdMPSSsj8arVjQ1kDsypA11trxf8kZYlnBvY+JApXeo7ifn4eTei+98j snwod/PiazgGC0GPWN6p09+v3UrJ7qh0sXgaP+fUGj2IMVlCseI= =AsPR -----END PGP SIGNATURE----- --=-=-=--