4.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx>
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@xxxxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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);
--
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