From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751289AbdIIXfX (ORCPT ); Sat, 9 Sep 2017 19:35:23 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:43076 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752431AbdIIXBL (ORCPT ); Sat, 9 Sep 2017 19:01:11 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Maged Mokhtar" , "Nicholas Bellinger" Date: Sat, 09 Sep 2017 22:47:14 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 100/233] iscsi-target: Fix early sk_data_ready LOGIN_FLAGS_READY race In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.48-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Nicholas Bellinger commit 8f0dfb3d8b1120c61f6e2cc3729290db10772b2d upstream. There is a iscsi-target/tcp login race in LOGIN_FLAGS_READY state assignment that can result in frequent errors during iscsi discovery: "iSCSI Login negotiation failed." To address this bug, move the initial LOGIN_FLAGS_READY assignment ahead of iscsi_target_do_login() when handling the initial iscsi_target_start_negotiation() request PDU during connection login. As iscsi_target_do_login_rx() work_struct callback is clearing LOGIN_FLAGS_READ_ACTIVE after subsequent calls to iscsi_target_do_login(), the early sk_data_ready ahead of the first iscsi_target_do_login() expects LOGIN_FLAGS_READY to also be set for the initial login request PDU. As reported by Maged, this was first obsered using an MSFT initiator running across multiple VMWare host virtual machines with iscsi-target/tcp. Reported-by: Maged Mokhtar Tested-by: Maged Mokhtar Signed-off-by: Nicholas Bellinger Signed-off-by: Ben Hutchings --- drivers/target/iscsi/iscsi_target_nego.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) --- a/drivers/target/iscsi/iscsi_target_nego.c +++ b/drivers/target/iscsi/iscsi_target_nego.c @@ -1251,16 +1251,16 @@ int iscsi_target_start_negotiation( { int ret; - ret = iscsi_target_do_login(conn, login); - if (!ret) { - if (conn->sock) { - struct sock *sk = conn->sock->sk; + if (conn->sock) { + struct sock *sk = conn->sock->sk; - write_lock_bh(&sk->sk_callback_lock); - set_bit(LOGIN_FLAGS_READY, &conn->login_flags); - write_unlock_bh(&sk->sk_callback_lock); - } - } else if (ret < 0) { + write_lock_bh(&sk->sk_callback_lock); + set_bit(LOGIN_FLAGS_READY, &conn->login_flags); + write_unlock_bh(&sk->sk_callback_lock); + } + + ret = iscsi_target_do_login(conn, login); + if (ret < 0) { cancel_delayed_work_sync(&conn->login_work); cancel_delayed_work_sync(&conn->login_cleanup_work); iscsi_target_restore_sock_callbacks(conn);