From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759374AbbIDNI7 (ORCPT ); Fri, 4 Sep 2015 09:08:59 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:49781 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759298AbbIDNIw (ORCPT ); Fri, 4 Sep 2015 09:08:52 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Sagi Grimberg , Nicholas Bellinger , Luis Henriques Subject: [PATCH 3.16.y-ckt 008/130] iscsi-target: Fix iser explicit logout TX kthread leak Date: Fri, 4 Sep 2015 14:06:36 +0100 Message-Id: <1441372118-5933-9-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1441372118-5933-1-git-send-email-luis.henriques@canonical.com> References: <1441372118-5933-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.7-ckt17 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Nicholas Bellinger commit 007d038bdf95ccfe2491d0078be54040d110fd06 upstream. This patch fixes a regression introduced with the following commit in v4.0-rc1 code, where an explicit iser-target logout would result in ->tx_thread_active being incorrectly cleared by the logout post handler, and subsequent TX kthread leak: commit 88dcd2dab5c23b1c9cfc396246d8f476c872f0ca Author: Nicholas Bellinger Date: Thu Feb 26 22:19:15 2015 -0800 iscsi-target: Convert iscsi_thread_set usage to kthread.h To address this bug, change iscsit_logout_post_handler_closesession() and iscsit_logout_post_handler_samecid() to only cmpxchg() on ->tx_thread_active for traditional iscsi/tcp connections. This is required because iscsi/tcp connections are invoking logout post handler logic directly from TX kthread context, while iser connections are invoking logout post handler logic from a seperate workqueue context. Cc: Sagi Grimberg Signed-off-by: Nicholas Bellinger Signed-off-by: Luis Henriques --- drivers/target/iscsi/iscsi_target.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c index cc401d217406..ce87bdcb1843 100644 --- a/drivers/target/iscsi/iscsi_target.c +++ b/drivers/target/iscsi/iscsi_target.c @@ -4515,7 +4515,18 @@ static void iscsit_logout_post_handler_closesession( struct iscsi_conn *conn) { struct iscsi_session *sess = conn->sess; - int sleep = cmpxchg(&conn->tx_thread_active, true, false); + int sleep = 1; + /* + * Traditional iscsi/tcp will invoke this logic from TX thread + * context during session logout, so clear tx_thread_active and + * sleep if iscsit_close_connection() has not already occured. + * + * Since iser-target invokes this logic from it's own workqueue, + * always sleep waiting for RX/TX thread shutdown to complete + * within iscsit_close_connection(). + */ + if (conn->conn_transport->transport_type == ISCSI_TCP) + sleep = cmpxchg(&conn->tx_thread_active, true, false); atomic_set(&conn->conn_logout_remove, 0); complete(&conn->conn_logout_comp); @@ -4529,7 +4540,10 @@ static void iscsit_logout_post_handler_closesession( static void iscsit_logout_post_handler_samecid( struct iscsi_conn *conn) { - int sleep = cmpxchg(&conn->tx_thread_active, true, false); + int sleep = 1; + + if (conn->conn_transport->transport_type == ISCSI_TCP) + sleep = cmpxchg(&conn->tx_thread_active, true, false); atomic_set(&conn->conn_logout_remove, 0); complete(&conn->conn_logout_comp);