Commit eebeb74b authored Mar 06, 2016 by Nicholas Bellinger Committed by Sasha Levin Mar 05, 2016

iscsi-target: Fix rx_login_comp hang after login failure



[ Upstream commit ca82c2bded29b38d36140bfa1e76a7bbfcade390 ]

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 e54198657b65625085834847ab6271087323ffea
  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>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

parent 0f67c5be

drivers/target/iscsi/iscsi_target.c

+12 −1

Original line number	Diff line number	Diff line
		@@ -4054,6 +4054,17 @@ 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;
		@@ -4071,7 +4082,7 @@ 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) {

drivers/target/iscsi/iscsi_target_nego.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -393,6 +393,7 @@ 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) {