From: Quinn Tran <quinn.tran@cavium.com>
Date: Fri, 2 Jun 2017 09:11:57 -0700
Subject: scsi: tcm_qla2xxx: Do not allow aborted cmd to advance.
Patch-mainline: v4.13-rc1
Git-commit: 694833ee00c4c56b3fc902515b7685a4186fe502
References: FATE#322910

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: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Quinn Tran <quinn.tran@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 drivers/scsi/qla2xxx/tcm_qla2xxx.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.c b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
index 7443e4efa3ae..1131fe8e2dd2 100644
--- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c
+++ b/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;
-- 
2.12.3