From d733caec1dde6c6493ff253d86a2e7404644edb5 Mon Sep 17 00:00:00 2001
From: chenxiang <chenxiang66@hisilicon.com>
Date: Wed, 6 Sep 2017 17:15:14 +0800
Subject: [PATCH 15/33] scsi: libsas: add event to defer list tail instead of
 head when draining

Git-commit: 7f6ab5693f66e5a638925f28e17ea7576fc69f2f
Patch-mainline: v4.15-rc1
References: bsc#1071401

Events will be added to defer_q list when setting ha->status to
SAS_HA_DRAINING. Events will be called after drain workqueue.

Those events are added to the head of list, but they are scanned one by
one from the head to the tail, which will cause those events be called
in the reverse order of being added. So change list_add to list_add_tail
in function sas_queue_work.

Signed-off-by: chenxiang <chenxiang66@hisilicon.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
CC: John Garry <john.garry@huawei.com>
CC: Johannes Thumshirn <jthumshirn@suse.de>
CC: Ewan Milne <emilne@redhat.com>
CC: Christoph Hellwig <hch@lst.de>
CC: Tomas Henzl <thenzl@redhat.com>
CC: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
---
 drivers/scsi/libsas/sas_event.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/libsas/sas_event.c b/drivers/scsi/libsas/sas_event.c
index 3e225ef9e0e5..0bb9eefc08c8 100644
--- a/drivers/scsi/libsas/sas_event.c
+++ b/drivers/scsi/libsas/sas_event.c
@@ -37,7 +37,7 @@ int sas_queue_work(struct sas_ha_struct *ha, struct sas_work *sw)
 	if (test_bit(SAS_HA_DRAINING, &ha->state)) {
 		/* add it to the defer list, if not already pending */
 		if (list_empty(&sw->drain_node))
-			list_add(&sw->drain_node, &ha->defer_q);
+			list_add_tail(&sw->drain_node, &ha->defer_q);
 	} else
 		rc = scsi_queue_work(ha->core.shost, &sw->work);
 
-- 
2.11.0