Description of problem:
xfs文件系统，xfstests ext4-overlay generic/604 +mount: /fs/vdb2 is already mounted or /fs/vdb2/ovl-mnt busy
arm均存在该问题,非regression，RC1版本亦存在此问题  x86 成功
an8成功

失败几率：必现

Version-Release number of selected component (if applicable):
# uname -r
4.19.91-26_rc3.an7.aarch64
# uname -r
4.19.91-26_rc3.an7.x86_64

# cat /etc/os-release
NAME="Anolis OS"
VERSION="7.7"
ID="anolis"
ID_LIKE="rhel fedora centos"
VERSION_ID="7.7"
PRETTY_NAME="Anolis OS 7.7"
ANSI_COLOR="0;31"
HOME_URL="https://openanolis.cn/"
BUG_REPORT_URL="https://bugs.openanolis.cn/"

CENTOS_MANTISBT_PROJECT="CentOS-7"
CENTOS_MANTISBT_PROJECT_VERSION="7"
REDHAT_SUPPORT_PRODUCT="centos"
REDHAT_SUPPORT_PRODUCT_VERSION="7"



How reproducible:
1. 准备环境
#准备disk1 disk2测试盘，视本地环境修改
disk1=vdb1
disk2=vdb2

dmsetup remove_all
wipefs -a --force /dev/$disk1
wipefs -a --force /dev/$disk2

mkfs -t ext4 -q -F /dev/$disk1
mkfs -t ext4 -q -F /dev/$disk2

export TEST_DIR=/fs/$disk1
export TEST_DEV=/dev/$disk1
export FSTYP=ext4
export SCRATCH_MNT=/fs/scratch
mkdir /fs/$disk1 -p
mkdir /fs/scratch -p
export SCRATCH_DEV=/dev/$disk2

2. 下载xfstests测试代码

3. 编译测试源码
cd xfstests-dev
export CFLAGS="-fcommon"
make
make install


Actual results:
./check -overlay tests/generic/604
FSTYP         -- overlay
PLATFORM      -- Linux/aarch64 iZ2zebfu2pfe96wy4xb5lsZ 4.19.91-26_rc3.an7.aarch64 #1 SMP Tue May 10 20:56:42 CST 2022
MKFS_OPTIONS  -- /fs/vdb2
MOUNT_OPTIONS -- /fs/vdb2 /fs/vdb2/ovl-mnt

generic/604 1s ... [failed, exit status 1]- output mismatch (see /tmp/tone/run/xfstests/results//generic/604.out.bad)
    --- tests/generic/604.out   2022-05-11 18:45:56.445456911 +0800
    +++ /tmp/tone/run/xfstests/results//generic/604.out.bad     2022-05-13 16:34:44.565421985 +0800
    @@ -1,2 +1,4 @@
     QA output created by 604
    -Silence is golden
    +mount: /fs/vdb2 is already mounted or /fs/vdb2/ovl-mnt busy
    +mount failed
    +(see /tmp/tone/run/xfstests/results//generic/604.full for details)
    ...
    (Run 'diff -u /tmp/tone/run/xfstests/tests/generic/604.out /tmp/tone/run/xfstests/results//generic/604.out.bad'  to see the entire diff)
Ran: generic/604
Failures: generic/604
Failed 1 of 1 tests

[root@iZ2zebfu2pfe96wy4xb5lsZ xfstests]# lsblk
NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
vdb    253:16   0  100G  0 disk
├─vdb2 253:18   0 47.7G  0 part
└─vdb1 253:17   0 45.8G  0 part
vda    253:0    0   40G  0 disk
├─vda2 253:2    0   39G  0 part /
└─vda1 253:1    0 1022M  0 part /boot/efi
[root@iZ2zebfu2pfe96wy4xb5lsZ xfstests]# df -l
Filesystem     1K-blocks     Used Available Use% Mounted on
devtmpfs         7774864        0   7774864   0% /dev
tmpfs            7818672        0   7818672   0% /dev/shm
tmpfs            7818672      708   7817964   1% /run
tmpfs            7818672        0   7818672   0% /sys/fs/cgroup
/dev/vda2       40121728 17630432  20639932  47% /
/dev/vda1        1044472     9288   1035184   1% /boot/efi
tmpfs            1563736        0   1563736   0% /run/user/0
[root@iZ2zebfu2pfe96wy4xb5lsZ xfstests]# ls /fs/vdb2/ovl-mnt
ls: cannot access /fs/vdb2/ovl-mnt: No such file or directory

Expected results:

Additional info:
xfsprogs-4.5.0-22.an7
xfsprogs-4.19.0-5.0.1.an7
均失败
arm均存在该问题,非regression，RC1版本亦存在此问题  x86成功
an8成功