aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJiang Yi <jiangyilism@gmail.com>2017-05-16 17:57:55 +0800
committerNicholas Bellinger <nab@linux-iscsi.org>2017-05-31 15:12:57 -0700
commit5e0cf5e6c43b9e19fc0284f69e5cd2b4a47523b0 (patch)
tree7b1807ba795acf651f2599442806f7f96649daf1
parent25cdda95fda78d22d44157da15aa7ea34be3c804 (diff)
downloadlinux-stericsson-5e0cf5e6c43b9e19fc0284f69e5cd2b4a47523b0.tar.gz
iscsi-target: Always wait for kthread_should_stop() before kthread exit
There are three timing problems in the kthread usages of iscsi_target_mod: - np_thread of struct iscsi_np - rx_thread and tx_thread of struct iscsi_conn In iscsit_close_connection(), it calls send_sig(SIGINT, conn->tx_thread, 1); kthread_stop(conn->tx_thread); In conn->tx_thread, which is iscsi_target_tx_thread(), when it receive SIGINT the kthread will exit without checking the return value of kthread_should_stop(). So if iscsi_target_tx_thread() exit right between send_sig(SIGINT...) and kthread_stop(...), the kthread_stop() will try to stop an already stopped kthread. This is invalid according to the documentation of kthread_stop(). (Fix -ECONNRESET logout handling in iscsi_target_tx_thread and early iscsi_target_rx_thread failure case - nab) Signed-off-by: Jiang Yi <jiangyilism@gmail.com> Cc: <stable@vger.kernel.org> # v3.12+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
-rw-r--r--drivers/target/iscsi/iscsi_target.c30
-rw-r--r--drivers/target/iscsi/iscsi_target_erl0.c6
-rw-r--r--drivers/target/iscsi/iscsi_target_erl0.h2
-rw-r--r--drivers/target/iscsi/iscsi_target_login.c4
4 files changed, 34 insertions, 8 deletions
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 26a9bcd5ee6a..0d8f81591bed 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -3790,6 +3790,8 @@ int iscsi_target_tx_thread(void *arg)
{
int ret = 0;
struct iscsi_conn *conn = arg;
+ bool conn_freed = false;
+
/*
* Allow ourselves to be interrupted by SIGINT so that a
* connection recovery / failure event can be triggered externally.
@@ -3815,12 +3817,14 @@ get_immediate:
goto transport_err;
ret = iscsit_handle_response_queue(conn);
- if (ret == 1)
+ if (ret == 1) {
goto get_immediate;
- else if (ret == -ECONNRESET)
+ } else if (ret == -ECONNRESET) {
+ conn_freed = true;
goto out;
- else if (ret < 0)
+ } else if (ret < 0) {
goto transport_err;
+ }
}
transport_err:
@@ -3830,8 +3834,13 @@ transport_err:
* responsible for cleaning up the early connection failure.
*/
if (conn->conn_state != TARG_CONN_STATE_IN_LOGIN)
- iscsit_take_action_for_connection_exit(conn);
+ iscsit_take_action_for_connection_exit(conn, &conn_freed);
out:
+ if (!conn_freed) {
+ while (!kthread_should_stop()) {
+ msleep(100);
+ }
+ }
return 0;
}
@@ -4004,6 +4013,7 @@ int iscsi_target_rx_thread(void *arg)
{
int rc;
struct iscsi_conn *conn = arg;
+ bool conn_freed = false;
/*
* Allow ourselves to be interrupted by SIGINT so that a
@@ -4016,7 +4026,7 @@ int iscsi_target_rx_thread(void *arg)
*/
rc = wait_for_completion_interruptible(&conn->rx_login_comp);
if (rc < 0 || iscsi_target_check_conn_state(conn))
- return 0;
+ goto out;
if (!conn->conn_transport->iscsit_get_rx_pdu)
return 0;
@@ -4025,7 +4035,15 @@ int iscsi_target_rx_thread(void *arg)
if (!signal_pending(current))
atomic_set(&conn->transport_failed, 1);
- iscsit_take_action_for_connection_exit(conn);
+ iscsit_take_action_for_connection_exit(conn, &conn_freed);
+
+out:
+ if (!conn_freed) {
+ while (!kthread_should_stop()) {
+ msleep(100);
+ }
+ }
+
return 0;
}
diff --git a/drivers/target/iscsi/iscsi_target_erl0.c b/drivers/target/iscsi/iscsi_target_erl0.c
index 9a96e17bf7cd..7fe2aa73cff6 100644
--- a/drivers/target/iscsi/iscsi_target_erl0.c
+++ b/drivers/target/iscsi/iscsi_target_erl0.c
@@ -930,8 +930,10 @@ static void iscsit_handle_connection_cleanup(struct iscsi_conn *conn)
}
}
-void iscsit_take_action_for_connection_exit(struct iscsi_conn *conn)
+void iscsit_take_action_for_connection_exit(struct iscsi_conn *conn, bool *conn_freed)
{
+ *conn_freed = false;
+
spin_lock_bh(&conn->state_lock);
if (atomic_read(&conn->connection_exit)) {
spin_unlock_bh(&conn->state_lock);
@@ -942,6 +944,7 @@ void iscsit_take_action_for_connection_exit(struct iscsi_conn *conn)
if (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT) {
spin_unlock_bh(&conn->state_lock);
iscsit_close_connection(conn);
+ *conn_freed = true;
return;
}
@@ -955,4 +958,5 @@ void iscsit_take_action_for_connection_exit(struct iscsi_conn *conn)
spin_unlock_bh(&conn->state_lock);
iscsit_handle_connection_cleanup(conn);
+ *conn_freed = true;
}
diff --git a/drivers/target/iscsi/iscsi_target_erl0.h b/drivers/target/iscsi/iscsi_target_erl0.h
index 60e69e2af6ed..3822d9cd1230 100644
--- a/drivers/target/iscsi/iscsi_target_erl0.h
+++ b/drivers/target/iscsi/iscsi_target_erl0.h
@@ -15,6 +15,6 @@ extern int iscsit_stop_time2retain_timer(struct iscsi_session *);
extern void iscsit_connection_reinstatement_rcfr(struct iscsi_conn *);
extern void iscsit_cause_connection_reinstatement(struct iscsi_conn *, int);
extern void iscsit_fall_back_to_erl0(struct iscsi_session *);
-extern void iscsit_take_action_for_connection_exit(struct iscsi_conn *);
+extern void iscsit_take_action_for_connection_exit(struct iscsi_conn *, bool *);
#endif /*** ISCSI_TARGET_ERL0_H ***/
diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c
index 66238477137b..92b96b51d506 100644
--- a/drivers/target/iscsi/iscsi_target_login.c
+++ b/drivers/target/iscsi/iscsi_target_login.c
@@ -1464,5 +1464,9 @@ int iscsi_target_login_thread(void *arg)
break;
}
+ while (!kthread_should_stop()) {
+ msleep(100);
+ }
+
return 0;
}