iscsi-target: Fix rx_login_comp hang after login failure

This patch addresses a case where iscsi_target_do_tx_login_io()
fails sending the last login response PDU, after the RX/TX
threads have already been started.

The case centers around iscsi_target_rx_thread() not invoking
allow_signal(SIGINT) before the send_sig(SIGINT, ...) occurs
from the failure path, resulting in RX thread hanging
indefinately on iscsi_conn->rx_login_comp.

Note this bug is a regression introduced by:

  commit e54198657b
  Author: Nicholas Bellinger <nab@linux-iscsi.org>
  Date:   Wed Jul 22 23:14:19 2015 -0700

      iscsi-target: Fix iscsit_start_kthreads failure OOPs

To address this bug, complete ->rx_login_complete for good
measure in the failure path, and immediately return from
RX thread context if connection state did not actually reach
full feature phase (TARG_CONN_STATE_LOGGED_IN).

Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: <stable@vger.kernel.org> # v3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Nicholas Bellinger 2015-11-05 14:11:59 -08:00
parent 82a819e8fb
commit ca82c2bded
2 changed files with 13 additions and 1 deletions

View File

@ -4074,6 +4074,17 @@ reject:
return iscsit_add_reject(conn, ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
}
static bool iscsi_target_check_conn_state(struct iscsi_conn *conn)
{
bool ret;
spin_lock_bh(&conn->state_lock);
ret = (conn->conn_state != TARG_CONN_STATE_LOGGED_IN);
spin_unlock_bh(&conn->state_lock);
return ret;
}
int iscsi_target_rx_thread(void *arg)
{
int ret, rc;
@ -4091,7 +4102,7 @@ int iscsi_target_rx_thread(void *arg)
* incoming iscsi/tcp socket I/O, and/or failing the connection.
*/
rc = wait_for_completion_interruptible(&conn->rx_login_comp);
if (rc < 0)
if (rc < 0 || iscsi_target_check_conn_state(conn))
return 0;
if (conn->conn_transport->transport_type == ISCSI_INFINIBAND) {

View File

@ -388,6 +388,7 @@ err:
if (login->login_complete) {
if (conn->rx_thread && conn->rx_thread_active) {
send_sig(SIGINT, conn->rx_thread, 1);
complete(&conn->rx_login_comp);
kthread_stop(conn->rx_thread);
}
if (conn->tx_thread && conn->tx_thread_active) {