scsi: tcm_qla2xxx: Do not allow aborted cmd to advance.

In case of hardware queue full, commands can loop between
TCM stack and tcm_qla2xx shim layers for retry. While command
is waiting for retry, task mgmt can get ahead and abort the
cmmand that encountered queue full condition. Fix this by
dropping the command, if task mgmt has already started the
command free process.
Acked-by: NNicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: NQuinn Tran <quinn.tran@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Reviewed-by: NBart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qla2xxx/tcm_qla2xxx.c

@@ -686,6 +686,19 @@ static int tcm_qla2xxx_queue_status(struct se_cmd *se_cmd)
 				struct qla_tgt_cmd, se_cmd);
 	int xmit_type = QLA_TGT_XMIT_STATUS;
 
+	if (cmd->aborted) {
+		/*
+		 * Cmd can loop during Q-full. tcm_qla2xxx_aborted_task
+		 * can get ahead of this cmd. tcm_qla2xxx_aborted_task
+		 * already kick start the free.
+		 */
+		pr_debug(
+		    "queue_data_in aborted cmd[%p] refcount %d transport_state %x, t_state %x, se_cmd_flags %x\n",
+		    cmd, kref_read(&cmd->se_cmd.cmd_kref),
+		    cmd->se_cmd.transport_state, cmd->se_cmd.t_state,
+		    cmd->se_cmd.se_cmd_flags);
+		return 0;
+	}
 	cmd->bufflen = se_cmd->data_length;
 	cmd->sg = NULL;
 	cmd->sg_cnt = 0;