Re: [PATCH] btrfs: default subvolume deletion test

[Omar Sandoval <osandov@osandov.com>]

On Wed, Jun 03, 2015 at 11:53:37AM +0800, Eryu Guan wrote:
> On Tue, Jun 02, 2015 at 07:35:03PM -0700, Omar Sandoval wrote:
> > Add a regression test for a problem where attempting to delete the
> > default subvolume would fail (as expected), but not until after all
> > submounts under the subvolume were unmounted.
> 
> I think the subject can be more specific than "btrfs: default subvolume
> deletion test", because btrfs/009 test the deletion of default subvol
> too, but this test tests more.

Agreed.

> > Signed-off-by: Omar Sandoval <osandov@osandov.com>
> > ---
> >  tests/btrfs/089     | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  tests/btrfs/089.out | 10 +++++++
> >  tests/btrfs/group   |  1 +
> >  3 files changed, 93 insertions(+)
> >  create mode 100755 tests/btrfs/089
> >  create mode 100644 tests/btrfs/089.out
> > 
> > diff --git a/tests/btrfs/089 b/tests/btrfs/089
> > new file mode 100755
> > index 000000000000..af28d996d5c6
> > --- /dev/null
> > +++ b/tests/btrfs/089
> > @@ -0,0 +1,82 @@
> > +#! /bin/bash
> > +# FS QA Test 089
> > +#
> > +# Test deleting the default subvolume, making sure that it fails and that
> > +# submounts under it are not unmounted prematurely. This is a regression test
> > +# for Linux commit "Btrfs: don't invalidate root dentry when subvolume deletion
> > +# fails".
> > +#
> > +#-----------------------------------------------------------------------
> > +# Copyright (c) 2015 YOUR NAME HERE.  All Rights Reserved.
> 
> The copyright should be fixed.

Whoops, not sure how I missed that.

> > +#
> > +# This program is free software; you can redistribute it and/or
> > +# modify it under the terms of the GNU General Public License as
> > +# published by the Free Software Foundation.
> > +#
> > +# This program is distributed in the hope that it would be useful,
> > +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > +# GNU General Public License for more details.
> > +#
> > +# You should have received a copy of the GNU General Public License
> > +# along with this program; if not, write the Free Software Foundation,
> > +# Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
> > +#-----------------------------------------------------------------------
> > +#
> > +
> > +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.*
> > +}
> > +
> > +# get standard environment, filters and checks
> > +. ./common/rc
> > +. ./common/filter
> > +. ./common/filter.btrfs
> > +
> > +# real QA test starts here
> > +
> > +# Modify as appropriate.
> > +_need_to_be_root
> > +_supported_fs btrfs
> > +_supported_os Linux
> > +_require_scratch
> > +
> > +rm -f $seqres.full
> > +
> > +_scratch_mkfs >>$seqres.full 2>&1
> > +_scratch_mount
> > +
> > +# Create a new subvolume and make it the default subvolume.
> > +$BTRFS_UTIL_PROG subvolume create "$SCRATCH_MNT/testvol" | _filter_scratch
> > +testvol_id=$($BTRFS_UTIL_PROG subvolume list "$SCRATCH_MNT/testvol" | awk '{print $2}')
> 
> I found there's a helper to get subvol id, see _btrfs_get_subvolid in
> common/rc

Okay, I'll fix that.

> > +$BTRFS_UTIL_PROG subvolume set-default "$testvol_id" "$SCRATCH_MNT"
> > +
> > +# Bind-mount a directory under the default subvolume.
> > +mkdir "$SCRATCH_MNT/testvol/testdir"
> > +touch "$SCRATCH_MNT/testvol/testdir/testfile"
> > +mkdir "$SCRATCH_MNT/testvol/mnt"
> > +mount --bind "$SCRATCH_MNT/testvol/testdir" "$SCRATCH_MNT/testvol/mnt"
> > +
> > +# Now attempt to delete the default subvolume, which should fail.
> > +$BTRFS_UTIL_PROG subvolume delete "$SCRATCH_MNT/testvol" 2>&1 | _filter_btrfs_subvol_delete
> > +
> > +# Make sure that the subvolume and bind mount survived.
> > +cd "$SCRATCH_MNT"
> > +find | sort
> > +
> > +cd "$here"
> > +_scratch_unmount
> 
> The cd and _scratch_unmount are not necessary here, _require_scratch
> deals with the umount.

Ah, yes, I can definitely get rid of the _scratch_unmount, but the cd
$here was there because otherwise the filesystem wouldn't unmount and
fsck would error out. Instead of cd-ing to SCRATCH_MNT, I can replace
find with find | _filter_scratch and update the test output accordingly.

> Thanks,
> Eryu

Thanks for reviewing! I'll send out v2.

> > +
> > +status=0
> > +exit
> > diff --git a/tests/btrfs/089.out b/tests/btrfs/089.out
> > new file mode 100644
> > index 000000000000..eb9c5112e12e
> > --- /dev/null
> > +++ b/tests/btrfs/089.out
> > @@ -0,0 +1,10 @@
> > +qa output created by 089
> > +create subvolume 'scratch_mnt/testvol'
> > +error: cannot delete 'scratch_mnt/testvol' - operation not permitted
> > +delete subvolume 'scratch_mnt/testvol'
> > +.
> > +./testvol
> > +./testvol/mnt
> > +./testvol/mnt/testfile
> > +./testvol/testdir
> > +./testvol/testdir/testfile
> > diff --git a/tests/btrfs/group b/tests/btrfs/group
> > index ffe18bff0d21..616d060758c1 100644
> > --- a/tests/btrfs/group
> > +++ b/tests/btrfs/group
> > @@ -91,6 +91,7 @@
> >  086 auto quick clone
> >  087 auto quick send
> >  088 auto quick metadata
> > +089 auto quick subvol
> >  090 auto quick metadata
> >  091 auto quick qgroup
> >  092 auto quick send
> > -- 
> > 2.4.2
> > 
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-- 
Omar