Re: [PATCH] btrfs: regression test for subvol deletion after rename

[Nikolay Borisov <nborisov@suse.com>]

On 19.12.19 г. 16:28 ч., Josef Bacik wrote:
> Test removal of a subvolume via rmdir after it has been renamed into a
> snapshot of the volume that originally contained the subvolume
> reference.
> 
> This currently fails on btrfs but is fixed by the patch with the title
> 
>   "btrfs: fix invalid removal of root ref"
> 
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> ---
>  tests/btrfs/202     | 54 +++++++++++++++++++++++++++++++++++++++++++++
>  tests/btrfs/202.out |  4 ++++
>  tests/btrfs/group   |  1 +
>  3 files changed, 59 insertions(+)
>  create mode 100755 tests/btrfs/202
>  create mode 100644 tests/btrfs/202.out
> 
> diff --git a/tests/btrfs/202 b/tests/btrfs/202
> new file mode 100755
> index 00000000..b02ee446
> --- /dev/null
> +++ b/tests/btrfs/202
> @@ -0,0 +1,54 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# FS QA Test 201
> +#
> +# Regression test for fix "btrfs: fix invalid removal of root ref"
> +#
> +seq=`basename $0`
> +seqres=$RESULT_DIR/$seq
> +echo "QA output created by $seq"
> +
> +here=`pwd`
> +tmp=/tmp/$$
> +status=1	# failure is the default!
> +trap "_cleanup; exit \$status" 0 1 2 3 15
> +
> +_cleanup()
> +{
> +	cd /
> +	rm -f $tmp.*
> +}
> +
> +. ./common/rc
> +. ./common/filter
> +
> +rm -f $seqres.full
> +
> +_supported_fs btrfs
> +_supported_os Linux
> +
> +_scratch_mkfs >> $seqres.full 2>&1
> +_scratch_mount
> +
> +# Create a subvol b under a and then snapshot a into c.  This create's a stub
> +# entry in c for b because c doesn't have a reference for b.
> +#
> +# But when we rename b c/foo it creates a ref for b in c.  However if we go to
> +# remove c/b btrfs used to depend on not finding the root ref to handle the
> +# unlink properly, but we now have a ref for that root.  We also had a bug that
> +# would allow us to remove mis-matched refs if the keys matched, so we'd end up
> +# removing too many entries which would cause a transaction abort.
> +
> +$BTRFS_UTIL_PROG subvolume create $SCRATCH_MNT/a | _filter_scratch
> +$BTRFS_UTIL_PROG subvolume create $SCRATCH_MNT/a/b | _filter_scratch
> +$BTRFS_UTIL_PROG subvolume snapshot $SCRATCH_MNT/a $SCRATCH_MNT/c \
> +	| _filter_scratch
> +ls $SCRATCH_MNT/c/b

Isn't this ls redundant?

> +mkdir $SCRATCH_MNT/c/foo
> +mv $SCRATCH_MNT/a/b $SCRATCH_MNT/c/foo
> +rm -rf $SCRATCH_MNT/*
> +touch $SCRATCH_MNT/blah
> +
> +status=0
> +exit
> diff --git a/tests/btrfs/202.out b/tests/btrfs/202.out
> new file mode 100644
> index 00000000..938870cf
> --- /dev/null
> +++ b/tests/btrfs/202.out
> @@ -0,0 +1,4 @@
> +QA output created by 201
> +Create subvolume 'SCRATCH_MNT/a'
> +Create subvolume 'SCRATCH_MNT/a/b'
> +Create a snapshot of 'SCRATCH_MNT/a' in 'SCRATCH_MNT/c'
> diff --git a/tests/btrfs/group b/tests/btrfs/group
> index d7eeb45d..7abc5f07 100644
> --- a/tests/btrfs/group
> +++ b/tests/btrfs/group
> @@ -204,3 +204,4 @@
>  199 auto quick trim
>  200 auto quick send clone
>  201 auto quick punch log
> +202 auto quick volume
>