Greeting,

FYI, we noticed the following commit (built with gcc-9):

commit: 58749022685aea90dfddfb9f8b2fcdc74dee6ec0 ("[PATCH 11/11] btrfs: use automount to bind-mount all subvol roots.")
url: https://github.com/0day-ci/linux/commits/NeilBrown/expose-btrfs-subvols-in-mount-table-correctly/20210728-064502
base: git://linux-nfs.org/~bfields/linux.git nfsd-next

in testcase: xfstests
version: xfstests-x86_64-76d2a91-1_20210728
with following parameters:

	disk: 6HDD
	fs: btrfs
	test: btrfs-group-20
	ucode: 0x28

test-description: xfstests is a regression test suite for xfs and other files ystems.
test-url: git://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git


on test machine: 8 threads 1 sockets Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz with 8G memory

caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):




If you fix the issue, kindly add following tag
Reported-by: kernel test robot <oliver.sang@intel.com>

2021-07-29 14:27:50 export TEST_DIR=/fs/sdb1
2021-07-29 14:27:50 export TEST_DEV=/dev/sdb1
2021-07-29 14:27:50 export FSTYP=btrfs
2021-07-29 14:27:50 export SCRATCH_MNT=/fs/scratch
2021-07-29 14:27:50 mkdir /fs/scratch -p
2021-07-29 14:27:50 export SCRATCH_DEV_POOL="/dev/sdb2 /dev/sdb3 /dev/sdb4 /dev/sdb5 /dev/sdb6"
2021-07-29 14:27:50 sed "s:^:btrfs/:" //lkp/benchmarks/xfstests/tests/btrfs-group-20
2021-07-29 14:27:50 ./check btrfs/200 btrfs/201 btrfs/202 btrfs/203 btrfs/204 btrfs/205 btrfs/207 btrfs/208 btrfs/209
FSTYP         -- btrfs
PLATFORM      -- Linux/x86_64 lkp-hsw-d01 5.13.0-rc2-00080-g58749022685a #1 SMP Wed Jul 28 21:12:27 CST 2021
MKFS_OPTIONS  -- /dev/sdb2
MOUNT_OPTIONS -- /dev/sdb2 /fs/scratch

btrfs/200	- output mismatch (see /lkp/benchmarks/xfstests/results//btrfs/200.out.bad)
    --- tests/btrfs/200.out	2021-07-28 06:20:35.000000000 +0000
    +++ /lkp/benchmarks/xfstests/results//btrfs/200.out.bad	2021-07-29 14:27:52.359748374 +0000
    @@ -10,8 +10,16 @@
     linked 65536/65536 bytes at offset 65536
     XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
     Create a readonly snapshot of 'SCRATCH_MNT' in 'SCRATCH_MNT/incr'
    -At subvol SCRATCH_MNT/incr
    +ERROR: not on mount point: SCRATCH_MNT/incr
     At subvol base
    -At snapshot incr
    ...
    (Run 'diff -u /lkp/benchmarks/xfstests/tests/btrfs/200.out /lkp/benchmarks/xfstests/results//btrfs/200.out.bad'  to see the entire diff)
btrfs/201	 18s
btrfs/202	- output mismatch (see /lkp/benchmarks/xfstests/results//btrfs/202.out.bad)
    --- tests/btrfs/202.out	2021-07-28 06:20:35.000000000 +0000
    +++ /lkp/benchmarks/xfstests/results//btrfs/202.out.bad	2021-07-29 14:28:10.873746534 +0000
    @@ -2,3 +2,4 @@
     Create subvolume 'SCRATCH_MNT/a'
     Create subvolume 'SCRATCH_MNT/a/b'
     Create a snapshot of 'SCRATCH_MNT/a' in 'SCRATCH_MNT/c'
    +rm: cannot remove '/fs/scratch/c': Device or resource busy
    ...
    (Run 'diff -u /lkp/benchmarks/xfstests/tests/btrfs/202.out /lkp/benchmarks/xfstests/results//btrfs/202.out.bad'  to see the entire diff)
btrfs/203	- output mismatch (see /lkp/benchmarks/xfstests/results//btrfs/203.out.bad)
    --- tests/btrfs/203.out	2021-07-28 06:20:35.000000000 +0000
    +++ /lkp/benchmarks/xfstests/results//btrfs/203.out.bad	2021-07-29 14:28:12.189746403 +0000
    @@ -16,10 +16,10 @@
     linked 196608/196608 bytes at offset 196608
     XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
     Create a readonly snapshot of 'SCRATCH_MNT' in 'SCRATCH_MNT/incr'
    -At subvol SCRATCH_MNT/incr
    +ERROR: not on mount point: SCRATCH_MNT/incr
     File foobar digest in the original filesystem:
     2b76b23b62fdbbbcae1ee37eec84fd7d
    ...
    (Run 'diff -u /lkp/benchmarks/xfstests/tests/btrfs/203.out /lkp/benchmarks/xfstests/results//btrfs/203.out.bad'  to see the entire diff)
btrfs/204	 2s
btrfs/205	 2s
btrfs/207	 49s
btrfs/208	[not run] /bin/btrfs too old (must support subvolume delete --subvolid)
btrfs/209	 1s
Ran: btrfs/200 btrfs/201 btrfs/202 btrfs/203 btrfs/204 btrfs/205 btrfs/207 btrfs/208 btrfs/209
Not run: btrfs/208
Failures: btrfs/200 btrfs/202 btrfs/203
Failed 3 of 9 tests




To reproduce:

        git clone https://github.com/intel/lkp-tests.git
        cd lkp-tests
        bin/lkp install                job.yaml  # job file is attached in this email
        bin/lkp split-job --compatible job.yaml  # generate the yaml file for lkp run
        bin/lkp run                    generated-yaml-file



---
0DAY/LKP+ Test Infrastructure                   Open Source Technology Center
https://lists.01.org/hyperkitty/list/lkp@lists.01.org       Intel Corporation

Thanks,
Oliver Sang