Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2993712AbbHHWU0 (ORCPT ); Sat, 8 Aug 2015 18:20:26 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36682 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2993212AbbHHWUW (ORCPT ); Sat, 8 Aug 2015 18:20:22 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sagi Grimberg , Nicholas Bellinger Subject: [PATCH 4.1 111/123] iscsi-target: Fix iser explicit logout TX kthread leak Date: Sat, 8 Aug 2015 15:09:49 -0700 Message-Id: <20150808220721.504787540@linuxfoundation.org> X-Mailer: git-send-email 2.5.0 In-Reply-To: <20150808220717.771230091@linuxfoundation.org> References: <20150808220717.771230091@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2897 Lines: 77 4.1-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: Greg Kroah-Hartman --- drivers/target/iscsi/iscsi_target.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) --- a/drivers/target/iscsi/iscsi_target.c +++ b/drivers/target/iscsi/iscsi_target.c @@ -4555,7 +4555,18 @@ static void iscsit_logout_post_handler_c 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); @@ -4569,7 +4580,10 @@ static void iscsit_logout_post_handler_c 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/