iscsi-target: Fix rx_login_comp hang after login failure

Nicholas Bellinger · Nicholas Bellinger · commit ca82c2bded29 · 2015-11-28T19:33:08.000-08:00
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 e541986 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>
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
@@ -4074,6 +4074,17 @@ static int iscsi_target_rx_opcode(struct iscsi_conn *conn, unsigned char *buf)
 	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) {
diff --git a/drivers/target/iscsi/iscsi_target_nego.c b/drivers/target/iscsi/iscsi_target_nego.c
@@ -388,6 +388,7 @@ static int iscsi_target_do_tx_login_io(struct iscsi_conn *conn, struct iscsi_log
 	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) {

Original file line number	Diff line number	Diff line change
`@@ -388,6 +388,7 @@ static int iscsi_target_do_tx_login_io(struct iscsi_conn *conn, struct iscsi_log`
`388`	`388`	`if (login->login_complete) {`
`389`	`389`	`if (conn->rx_thread && conn->rx_thread_active) {`
`390`	`390`	`send_sig(SIGINT, conn->rx_thread, 1);`
	`391`	`+ complete(&conn->rx_login_comp);`
`391`	`392`	`kthread_stop(conn->rx_thread);`
`392`	`393`	`}`
`393`	`394`	`if (conn->tx_thread && conn->tx_thread_active) {`