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Message-Id: <1440713521-5906-91-git-send-email-kamal@canonical.com>
Date: Thu, 27 Aug 2015 15:11:21 -0700
From: Kamal Mostafa <kamal@...onical.com>
To: linux-kernel@...r.kernel.org, stable@...r.kernel.org,
kernel-team@...ts.ubuntu.com
Cc: Sagi Grimberg <sagig@...lanox.com>,
Nicholas Bellinger <nab@...ux-iscsi.org>,
Kamal Mostafa <kamal@...onical.com>
Subject: [PATCH 3.19.y-ckt 090/130] iscsi-target: Fix iser explicit logout TX kthread leak
3.19.8-ckt6 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Nicholas Bellinger <nab@...ux-iscsi.org>
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 <nab@...ux-iscsi.org>
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 <sagig@...lanox.com>
Signed-off-by: Nicholas Bellinger <nab@...ux-iscsi.org>
Signed-off-by: Kamal Mostafa <kamal@...onical.com>
---
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 cc16d0b..4e08d63 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -4512,7 +4512,18 @@ 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);
@@ -4526,7 +4537,10 @@ 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);
--
1.9.1
--
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