target: Set CMD_T_ACTIVE bit for Task Management Requests

This patch fixes a bug where se_cmd descriptors associated with a
Task Management Request (TMR) where not setting CMD_T_ACTIVE before
being dispatched into target_tmr_work() process context.

This is required in order for transport_generic_free_cmd() ->
transport_wait_for_tasks() to wait on se_cmd->t_transport_stop_comp
if a session reset event occurs while an ABORT_TASK is outstanding
waiting for another I/O to complete.

Cc: Thomas Glanzmann <thomas@glanzmann.de>
Cc: Charalampos Pournaris <charpour@gmail.com>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_transport.c

@@ -2934,6 +2934,12 @@ static void target_tmr_work(struct work_struct *work)
 int transport_generic_handle_tmr(
 	struct se_cmd *cmd)
 {
+	unsigned long flags;
+
+	spin_lock_irqsave(&cmd->t_state_lock, flags);
+	cmd->transport_state |= CMD_T_ACTIVE;
+	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+
 	INIT_WORK(&cmd->work, target_tmr_work);
 	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
 	return 0;